Underwear-shaped disposable diapers

Abstract

An underwear-like disposable diaper (1) includes: an absorbent body (10) including an absorbent core (11); and a waist portion (20) capable of stretching and contracting in a lateral direction, wherein, assuming that a stretching state of the waist portion (20) when stretched in the lateral direction until its size is the same as that of a single sheet member constituting the waist portion (20) is defined as a maximum stretching state, then when the waist portion (20) is stretched in the lateral direction up to 70% of the size of the single sheet member, the waist portion (20) has a region (71) in the maximum stretching state located in at least a portion outside the absorbent core (11) in the lateral direction.

Description

Technical Field

[0001] This invention relates to a disposable diaper in the shape of underwear. Background Technology

[0002] In panty-like disposable diapers, to prevent the diaper from slipping off the wearer's body (waist) while wearing it, a common practice is to arrange as many elastic waist components (e.g., elastic cords) as possible to ensure close contact between the diaper and the wearer's body, thereby enhancing the contraction around the waist. For example, Patent Document 1 discloses a panty-like absorbent article in which multiple elastic waist components 52 are arranged in a waist portion E positioned around the waist and extending in the circumferential direction.

[0003] Citation List

[0004] Patent documents

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

[0006] Technical issues

[0007] When wearing panty-like diapers with elastic waistbands (such as the elastic cords arranged in the waist section as described in Patent Document 1), there is a risk that the contractile force generated by the elastic waistbands may leave linear or band-like rubber marks on the wearer's skin, or cause skin pain, thus causing discomfort to the wearer. On the other hand, when the contractile force is reduced so that rubber marks are less likely to be left, there is a risk that the waist section may slip off the wearer's body.

[0008] The present invention was made in view of conventional problems such as those described above, and one aspect of the present invention is to provide an underwear-shaped disposable diaper that reduces discomfort caused by elastic components leaving marks on the wearer's skin, while inhibiting slippage of the waist portion when wearing the diaper.

[0009] Solution to the problem

[0010] A key aspect of the present invention for achieving the above-mentioned aspects is a panty-shaped disposable diaper having intersecting vertical, horizontal, and front-back directions. The panty-shaped disposable diaper includes: an absorbent body comprising a liquid-absorbent core; and a waist portion capable of stretching and contracting in the horizontal direction. The maximum stretching state is defined as the stretching state of the waist portion when it is stretched in the horizontal direction until its size reaches the size of the sheet-like component constituting the waist portion. When the waist portion is stretched in the horizontal direction until its size reaches 70% of the size of the sheet-like component, the waist portion has a region in the maximum stretching state in at least a portion of the portion located outside the absorbent core in the horizontal direction.

[0011] Other features of the invention, in addition to those described above, will become clearer upon reading the description in this specification and referring to the accompanying drawings.

[0012] Advantages of the present invention

[0013] According to the present invention, a panty-like disposable diaper can be provided, which can reduce discomfort caused by elastic components leaving marks on the wearer's skin when the diaper is worn, while inhibiting slippage of the waist portion. Attached Figure Description

[0014] Figure 1 : This is a schematic 3D diagram of diaper 1.

[0015] Figure 2 : This is a plan view of diaper 1 in its unfolded and maximum stretched states.

[0016] Figure 3 : is along Figure 2 A schematic cross-sectional view taken along line AA.

[0017] Figure 4 : is along Figure 2 A schematic cross-sectional view taken from the middle BB line.

[0018] Figure 5 : This is a schematic cross-sectional view taken in the vertical direction when diaper 1 is being worn.

[0019] Figure 6: Figure 6A and 6B This is a schematic cross-sectional view showing the waist portion 20 of the diaper 1 in a stretched state.

[0020] Figure 7: Figure 7A and 7B This is a schematic diagram illustrating an example of a method for stretching diaper 1 in the lateral direction.

[0021] Figure 8: Figure 8A This is a schematic diagram showing the state in which the wearer is wearing a traditional underwear-like diaper 2 (comparative example). Figure 8B This is a schematic diagram showing the state in which the wearer is wearing the underwear-shaped diaper 1 of this embodiment.

[0022] Figure 9 This is a schematic diagram showing a modified example of the front low-flexibility region 61. Detailed Implementation

[0023] From the description of this specification and the accompanying drawings, at least the following matters can be made clear.

[0024] A panty-shaped disposable diaper has intersecting vertical, horizontal, and front-back directions. The panty-shaped disposable diaper includes: an absorbent body comprising a liquid-absorbent core; and a waist portion capable of stretching and contracting in the horizontal direction. The maximum stretch state is defined as the stretching state of the waist portion when it is stretched horizontally until its size reaches the size of the sheet-like component constituting the waist portion. When the waist portion is stretched horizontally until its size reaches 70% of the size of the sheet-like component, the waist portion has a region in the maximum stretch state located outside the absorbent core in the horizontal direction.

[0025] According to the aforementioned panty-like disposable diaper, a specific area in the waist section located on the outer side of the absorbent core in the lateral direction has a size equal to that in its maximum stretched state. This facilitates face-to-face contact between the waist section and the wearer's skin in this area. Therefore, when the diaper is put on (at 70% stretch), this area, maintaining a flat shape, makes close contact with the wearer's waist for reinforcement, making it less prone to positional shift of the waist section. Furthermore, the waist section easily maintains a flat shape, thus dispersing the contractile force (pressure) caused by elastic components in the waist area. This reduces the likelihood of linear marks being left on the wearer's skin and / or suppresses pain. This makes the wearer less likely to experience discomfort.

[0026] In a panty-shaped disposable diaper, it is desirable that the waist portion has a front waist portion and a back waist portion, and when the waist portion is stretched in the lateral direction until the size of the waist portion reaches 70% of the size of the sheet component itself, the front waist portion has an area in the maximum stretched state in at least a portion of the portion located outside the absorbent core in the lateral direction.

[0027] According to the aforementioned underwear-shaped disposable diaper, when the diaper is worn, the portion of the front waist area located laterally outside the absorbent core and in contact with the wearer's groin tends to maintain a flat shape. This suppresses the localized pressure of elastic cords, etc., acting on the groin. Therefore, it is less likely to generate strong contractile forces around the groin, making the wearer more prone to discomfort.

[0028] In a panty-shaped disposable diaper, it is desirable that the waist portion has a front waist portion and a back waist portion, and when the waist portion is stretched in the lateral direction until the size of the waist portion reaches 70% of the size of the sheet component itself, the back waist portion has an area in the maximum stretched state in at least a portion of the portion located outside the absorbent core in the lateral direction.

[0029] Based on the aforementioned underwear-shaped disposable diaper, when worn, the area in contact with the buttocks (the area on the lower back, located laterally outside the absorbent core) tends to maintain a flat shape. Therefore, heat is less likely to remain between the lower back and the wearer's skin, and sweat can evaporate effectively. Consequently, stuffiness and rashes on the buttocks are suppressed, making the wearer less uncomfortable.

[0030] In a panty-like disposable diaper, it is desirable that the back waist portion includes a skin side piece and a non-skin side piece covering the non-skin side of the skin side piece, and that at least a portion of the area of ​​the non-skin side piece in its maximum stretched state has a through-hole penetrating the non-skin side piece in the thickness direction.

[0031] Based on the aforementioned underwear-shaped disposable diaper, even when the back waist area stretches and contracts laterally while the diaper is worn, the area of ​​maximum stretch on the non-skin side panel (the low-elasticity area at the back) is less prone to contraction and maintains a flat shape. Therefore, the perforations in this area are less likely to contract laterally. Consequently, the perforations are less likely to become clogged, making breathability and evaporation less susceptible to impairment. Furthermore, this improves the visibility of the perforations when viewed from the outside (non-skin side) of the diaper, making it easier for the user to perceive the diaper's excellent breathability.

[0032] In a panty-shaped disposable diaper, it is desirable to have an elastic region that stretches and contracts in the lateral direction on each side of the area in the waist portion where it is in the maximum stretching state.

[0033] According to the aforementioned panty-like disposable diaper, when the diaper is put on, the area at maximum stretch (the front low-elasticity area) is pulled to both sides in the lateral direction, making close contact with the wearer's skin for reinforcement and tightening. This prevents this area from slipping off the wearer's skin. Therefore, a good fit can be achieved, while making the wearer less likely to feel discomfort.

[0034] In a disposable underwear-shaped diaper, it is desirable that the waist portion has a front waist portion and a back waist portion, and that if the width in the lateral direction of the area in the maximum stretch state of either the front waist portion or the back waist portion is greater than the width in the lateral direction of the area in the maximum stretch state of the other waist portion, then the contractile force in the lateral direction of the other waist portion is greater than the contractile force in the lateral direction of the first waist portion.

[0035] Based on the aforementioned underwear-shaped disposable diaper, when wearing the diaper, the waist area on one side is easily pulled laterally to both sides by the contraction force of the waist area on the other side. Therefore, the area on one side of the waist area that is in a state of maximum stretch (the low-elasticity area) tends to maintain a flat shape. This makes it easier to prevent the elastic components in the waist area from leaving linear marks on the wearer's skin and / or causing pain.

[0036] In a panty-like disposable diaper, it is desirable that the waist portion has skin side pieces and non-skin side pieces that overlap in the thickness direction, and that in at least a portion of the portion located outside the absorbent core in the transverse direction, the waist portion has a non-jointed portion in the region of maximum stretch, the non-jointed portion being the portion where the skin side pieces and the non-skin side pieces do not join to each other.

[0037] According to the aforementioned panty-like disposable diaper, in the area of ​​the front waistband where the skin side panel easily makes face-to-face contact with the wearer's skin (the area located outside the absorbent core in the lateral direction), the skin side panel does not join with the non-skin side panel, thus increasing the flexibility of the skin side panel. Therefore, the texture near the wearer's groin area can be improved. Furthermore, since the external (non-skin side panel) feels softer, it easily gives the wearer the impression that the diaper is soft.

[0038] In a panty-shaped disposable diaper, it is desirable that the panty-shaped disposable diaper further includes a body joining portion that joins the waist portion to the non-skin side of the absorbent body, and that the tensile strength of the skin side sheet, which is in a state of maximum stretch and further stretched by 5% in the vertical direction when viewed along the thickness direction, is greater than the tensile strength of the non-skin side sheet, which is in a state of maximum stretch and further stretched by 5% in the vertical direction.

[0039] Based on the aforementioned underwear-shaped disposable diaper, by maximizing the 5% tensile strength of the skin side panel in the vertical direction, the skin side panel can resist tension even when the absorbent body absorbs urine and its weight increases, causing it to be pulled downwards by the absorbent body. This allows the skin side panel to easily contact the wearer's skin while maintaining its flat shape. This also makes it easier to prevent the elastic waistband or similar components from leaving linear marks on the wearer's skin and / or causing pain.

[0040] In a panty-shaped disposable diaper, it is desirable that the waist portion has a front waist portion and a back waist portion, and a pair of side joining portions are disposed at two ends in the lateral direction, the pair of side joining portions connecting the front waist portion and the back waist portion in a ring, and at a specific position in the vertical direction, the shortest distance along the surface of the front waist portion from one side joining portion to the other side joining portion is longer than the shortest distance along the surface of the back waist portion from one side joining portion to the other side joining portion.

[0041] Based on the aforementioned underwear-shaped disposable diaper, because the contact area between the front waist portion and the wearer's skin is larger than that of the back waist portion, the part of the front waist portion in its maximum stretch state (the front low-elasticity area) easily contacts the wearer's skin in a planar manner. This makes it easier to prevent the elastic components or similar parts in the waist area from leaving linear marks on the wearer's skin and / or causing pain.

[0042] In a panty-shaped disposable diaper, it is desirable that the waist portion has a front waist portion and a back waist portion. The front waist portion has a front low elasticity region with reduced elasticity compared to other regions. The back waist portion has a rear first elasticity region and a rear second elasticity region. The rear first elasticity region is a region that overlaps with the front low elasticity region in the vertical direction. The rear second elasticity region is a region that is adjacent to and above the rear first elasticity region. Furthermore, the contractile force in the lateral direction acting on a region with a unit length in the vertical direction in the rear first elasticity region is greater than the contractile force in the lateral direction acting on a region with a unit length in the vertical direction in the rear second elasticity region.

[0043] According to the above-mentioned underwear-shaped disposable diaper, the greater the lateral contraction force in the first elastic region at the rear, the easier it is for the low elastic region at the front to be pulled and widened in the lateral direction. Therefore, making the lateral contraction force in the first elastic region at the rear stronger than the lateral contraction force in the second elastic region at the rear makes it easier for the low elastic region at the front to maintain its planar shape.

[0044] In a disposable diaper resembling underwear, it is desirable that the front waist portion has a front first elastic region, which is a region that overlaps with the front low elastic region in the vertical direction and is adjacent to both sides of the front low elastic region in the lateral direction. The contraction force in the rear first elastic region acting on a region with a unit length in the vertical direction is greater than the contraction force in the front low elastic region and the front first elastic region acting on a region with a unit length in the vertical direction.

[0045] According to the aforementioned underwear-shaped disposable diaper, the lateral contractile force acting on the waist portion gradually increases from the front to the back along the waist portion. This, for example, can make the wearer's skin less prone to discomfort due to sudden changes in the contractile force in the waist portion of the diaper.

[0046] In a disposable diaper resembling underwear, it is desirable that the front waist portion has a first front elastic region and a second front elastic region. The first front elastic region is a region that overlaps with the lower front elastic region in the vertical direction and is adjacent to both sides of the lower front elastic region in the horizontal direction. The second front elastic region is a region that is adjacent to and above the lower front elastic region and the first front elastic region in the vertical direction. Each of the first front elastic region and the second front elastic region is provided with a plurality of linear elastic elements, and the vertical spacing of the linear elastic elements arranged in the second front elastic region is greater than the vertical spacing of the linear elastic elements arranged in the first front elastic region.

[0047] According to the aforementioned underwear-shaped disposable diaper, the greater the vertical spacing of the elastic components in the front waistband, the smaller the total contact area between the elastic components and the wearer's skin. Therefore, when wearing the diaper, linear marks from the elastic components in the front waistband are less likely to remain on the wearer's skin. Thus, by increasing the spacing of the elastic components in the front second elastic area, marks from the elastic components in the front waistband are less likely to be left throughout the entire front waist area (including the front low elastic area and the front second elastic area adjacent to and above the front low elastic area). This also makes the wearer less likely to experience discomfort.

[0048] In a disposable diaper resembling underwear, it is desirable that each of the rear first elastic region and the rear second elastic region is provided with a plurality of linear elastic members, and the vertical spacing of the linear elastic members arranged in the rear second elastic region is greater than the vertical spacing of the linear elastic members arranged in the rear first elastic region.

[0049] According to the aforementioned panty-shaped disposable diaper, because the spacing between the elastic members at the back waist in the first elastic region at the back is narrow, the contractile force of the elastic members at the back waist acting on the first elastic region at the back is easily increased. Therefore, the low elastic region at the front and the first elastic region at the front are easily pulled to both sides in the lateral direction by the first elastic region at the back. This prevents the first elastic region at the back from becoming loose and allows the first elastic region at the front to easily maintain a flat shape when the diaper is put on.

[0050] Example

[0051] The following description uses a disposable diaper in the shape of underwear (hereinafter also referred to as "diaper 1") as an example to illustrate the absorbent articles in the shape of underwear according to the present invention. However, the diaper in the shape of underwear according to the present invention is also applicable to absorbent articles in the shape of underwear other than diapers, such as sanitary napkins in the shape of underwear and other absorbent articles in the shape of underwear.

[0052] Construction of Diaper 1

[0053] Figure 1 This is a schematic 3D diagram of diaper 1. Figure 2 This is a plan view of diaper 1 in its unfolded and maximum stretched states. Figure 3 It is along Figure 2 A schematic cross-sectional view taken along line AA. Figure 4 It is along Figure 2 A schematic cross-sectional view taken along the BB line. Note that in this specification, the "maximum stretch state" of diaper 1 refers to the state where the entire diaper 1 (the whole product) is stretched to the point where wrinkles are almost eliminated. Specifically, it refers to the state where the diaper is stretched until the dimensions of the components of diaper 1 reach the dimensions of the sheet-like components that make up those components (size matching or close; for example, until the difference is within ±5%). For example, the term "maximum stretch state" means that the front waist portion 30 is stretched until the dimensions of the front waist portion 30 reach the dimensions of the skin side panels 31 that make up the front waist portion 30 (see...). Figure 3 ).

[0054] exist Figure 1 In the panty-like configuration shown, the diaper 1 has intersecting vertical, horizontal, and front-back directions, and includes a waist opening (BH) and a pair of leg openings (LH and LH). The upper side in the vertical direction corresponds to the waist opening side, and the lower side corresponds to the crotch side. Furthermore, the front side in the front-back direction corresponds to the wearer's abdomen, and the back side corresponds to the wearer's back. Additionally, in... Figure 2 In its unfolded state, diaper 1 has intersecting longitudinal and transverse directions. The longitudinal direction is... Figure 1 The vertical direction is consistent with the longitudinal direction of the absorbent body 10, and corresponds to the longitudinal direction of the absorbent body 10. The transverse direction is consistent with... Figure 1 The horizontal direction is consistent. Furthermore, as... Figure 3 As shown, the components of diaper 1 overlap in the thickness direction. In the thickness direction, the side that contacts the wearer's skin is the skin side, and the side opposite to the skin side is the non-skin side.

[0055] The diaper 1 has a liquid-absorbing absorbent body 10 and a waist portion 20, which is located on the non-skin side of the absorbent body 10. The waist portion 20 includes a front waist portion 30 corresponding to the front of the diaper 1 and a back waist portion 40 corresponding to the back of the diaper 1. That is, the diaper 1 in this embodiment is a so-called three-piece panty-like diaper, including the absorbent body 10 as the first component (which contacts the wearer's crotch and absorbs urine and other excrement), the front waist portion 30 as the second component (which covers the wearer's front side), and the back waist portion 40 as the third component (which covers the wearer's back side). However, the diaper 1 is not limited to being a three-piece diaper, and can also be a two-piece panty-like diaper, which has a waist portion 20 and an absorbent body 10 integrally formed for the front and back sides.

[0056] exist Figure 2 In its unfolded state, with the front waist portion 30 and the back waist portion 40 arranged parallel to each other in the longitudinal direction, the absorbent body 10 spans between the front waist portion 30 and the back waist portion 40, and the ends 10ea and 10eb of the absorbent body 10 in the longitudinal direction are connected and fixed to the skin side of the nearest waist portion 30 and 40, forming a generally H-shaped external shape in the plan view. The absorbent body 10 in this state is then folded once at the folded position, which is the center position CL in the longitudinal direction. In this folded state, the front waist portion 30 and the back waist portion 40, facing each other, join and connect with each other at two side portions 30sw and 40sw in the transverse direction, forming a pair of side joining portions 50 and 50. That is, the front waist portion 30 and the back waist portion 40 form a ring through this pair of side joining portions 50 and 50. Thus, the diaper 1 is formed into an underwear-like state, wherein the waist opening BH and a pair of leg openings LH and LH are formed as shown... Figure 1 As shown. Note that the side joint portion 50 is formed by well-known joining methods such as welding or bonding.

[0057] Absorbent body 10

[0058] like Figure 3 and Figure 4As shown, the absorbent body 10 has an absorbent core 11 for absorbing excreted liquid, a top sheet 12 disposed on the skin side relative to the absorbent core 11 along the thickness direction, and a back sheet 13 disposed on the non-skin side relative to the absorbent core 11. However, the absorbent body 10 may also include other sheet-like components. For example, a second sheet (not shown) may be disposed between the top sheet 12 and the absorbent core 11 in the thickness direction.

[0059] The absorbent core 11 is a component that absorbs and retains excretory fluids such as urine, and is formed, for example, from liquid-absorbent fibers (such as pulp fibers) containing a superabsorbent polymer (SAP). It should be noted that the outer peripheral surface of the absorbent core 11 may be covered by a liquid-permeable sheet component, such as thin cotton paper or nonwoven fabric (e.g., Figure 4 (Chip 11b in the middle).

[0060] The top sheet 12 is a liquid-permeable sheet made of hydrophilic, breathable nonwoven fabric, spunbond nonwoven fabric, or similar materials. The back sheet 13 has a double-layer structure, comprising a liquid-impermeable sheet 13a and a hydrophobic outer sheet 13b disposed on the non-skin side of the liquid-impermeable sheet 13a. The liquid-impermeable sheet 13a may be a resin film or similar material, and the outer sheet 13b may be a flexible nonwoven fabric sheet.

[0061] In the two side portions of the absorbent body 10 in the lateral direction, a pair of leak-proof wall portions 15 are respectively provided to extend in 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. In particular, in the lateral direction (crossing direction), a portion of the outer sheet 13b extends beyond the two ends 11es and 11es of the absorbent core 11 and folds towards the skin at a folded position, as shown in the figure. Figure 4 The outer ends 15es1 and 15es2 are shown. This pair of leak-proof wall portions 15 is formed by further folding the outer sheet 13b at multiple locations on the skin side relative to the absorbent core 11. At the skin-side end (front end) of each leak-proof wall portion 15, a leak-proof wall elastic member 16 (such as an elastic cord) is attached, which is stretched in the longitudinal direction (the length direction of the absorbent body 10). When the diaper 1 is put on, the leak-proof wall portions 15 rise from the rising point (i.e., the outer ends 15es and 15es) toward the wearer's skin side, and therefore, due to the elasticity formed by the leak-proof wall elastic member 16, the diaper 1 fits snugly against the wearer's crotch.

[0062] Furthermore, on the two side portions of the absorbent body 10 in the lateral direction, there are attached leg elastic members 17 (such as elastic cords) that are stretched in the longitudinal direction (the length direction of the absorbent body 10). When the diaper 1 is put on, due to the elasticity formed by the leg elastic members 17, the two side portions of the absorbent body 10 contract, and the diaper 1 easily fits around the wearer's legs.

[0063] Front waist section 30

[0064] like Figure 3 As shown, the front waist portion 30 includes: a skin side sheet 31 arranged along the thickness direction on the skin side; a non-skin side sheet 32 ​​covering the non-skin side of the skin side sheet 31; and a front waist elastic member 35 (hereinafter also simply referred to as "waist elastic member 35") disposed along the thickness direction between the skin side sheet 31 and the non-skin side sheet 32. The front waist portion 30 basically has a two-layer structure composed of the skin side sheet 31 and the non-skin side sheet 32, but may also partially have a three-layer or more-layer structure (including the skin surface sheet 36, etc., described later). Figure 2 As shown, the skin side panel 31 is a sheet-like component with a rectangular shape in the plan view and is made of SMS nonwoven fabric or a similar material. Similarly, the non-skin side panel 32 is also a sheet-like component with a rectangular shape in the plan view and is made of spunbond nonwoven fabric or a similar material. Furthermore, as sheet-like components constituting the front waist portion 30 (especially the non-skin side panel 32), a nonwoven fabric sheet (so-called perforated nonwoven fabric sheet) with multiple through-holes penetrating the sheet-like component in the thickness direction can be used. Providing through-holes in the sheet can improve breathability.

[0065] In this embodiment, the front waist portion 30 has a folded-back portion 32f, wherein the upper end (front end in the longitudinal direction) of the non-skin side piece 32 folds back from the non-skin side to the skin side and from the upper side to the lower side in the vertical direction. By covering a portion (upper end) of the skin side piece 31 with the folded-back portion 32f, the upper edge of the skin side piece 31 is prevented from poking into the wearer's skin. However, it is not necessary to provide the folded-back portion 32f.

[0066] Multiple waist elastic components 35 are linear elastic components formed of elastic cords or the like, and are attached while being stretched in the lateral direction, while being arranged side by side in the vertical direction between the skin side panel 31 and the non-skin side panel 32. Due to the elasticity of the waist elastic components 35, the front waist portion 30 fits around the wearer's front waist.

[0067] The waist elastic member 35 can be attached using an adhesive such as hot melt adhesive. For example, the waist elastic member 35 can be attached by applying hot melt adhesive to the waist elastic member 35, and stretching the waist elastic member 35 at a predetermined tensile coefficient and sandwiching it between the skin side piece 31 and the non-skin side piece 32. That is, the skin side piece 31 and the non-skin side piece 32 are bonded together with adhesive via the waist elastic member 35. Alternatively, the waist elastic member 35 can be attached by applying adhesive to the side of the skin side piece 31 and the side of the non-skin side piece 32.

[0068] In addition, the front waist portion 30 may have a skin surface sheet 36. For example... Figure 3 As shown, the skin surface sheet 36 is a sheet-like component arranged to cover the upper end 10ea (front end in the longitudinal direction) of the absorbent body 10 from the skin side, and functions as a cover. This prevents the upper edge of the absorbent body 10 from poking into the wearer's skin when wearing the diaper 1. The skin surface sheet 36 is made of SMS nonwoven fabric or a similar material. It is not mandatory to provide the skin surface sheet 36 here.

[0069] The front waist portion 30 is joined to the non-skin side surface of the absorbent body 10 via a body joint portion 23 formed by an adhesive such as hot melt adhesive (see...). Figure 3 The main body joining portion 23 is formed by applying an adhesive with a spiral pattern, Ω-shaped pattern or similar pattern to the area where the front waist portion 30 and the absorbent main body 10 overlap when viewed along the thickness direction.

[0070] Lower back area 40

[0071] The structure of the lower back portion 40 is basically the same as that of the front lower back portion 30. That is, the lower back portion 40 includes: a skin side sheet 41 arranged along the thickness direction on the skin side; a non-skin side sheet 42 covering the non-skin side of the skin side sheet 41 and adjacent to it; and a lower back elastic member 45 (hereinafter also simply referred to as "lower back elastic member 45") disposed along the thickness direction between the skin side sheet 41 and the non-skin side sheet 42. The construction of these members is basically the same as that of the front lower back portion 30.

[0072] However, the external shape of the rear waist portion 40 differs from the external shape of the front waist portion 30. Specifically, as... Figure 2 As shown, the lower back portion 40 includes a hip cover 40b, which has a generally trapezoidal shape below the side joining portion 50 (side portion 40sw) in the vertical direction. In the hip cover 40b, the width in the lateral direction increases from the lower side to the upper side in the vertical direction. The hip cover 40b is configured such that the lower back portion 40 can cover the wearer's hips when the diaper 1 is worn.

[0073] The lower back portion 40 is joined to the non-skin side surface of the absorbent body 10 via a body joint portion 24 formed by an adhesive such as hot melt adhesive (see [link]). Figure 3 The main body joining portion 24 is formed in a manner that is basically the same as that of the main body joining portion 23.

[0074] Low stretching area

[0075] As described above, the waist elastic members 35 and 45 are attached to the waist portion 20 (30, 40) of the diaper 1 in a stretched state in the lateral direction. Due to the contractile force exhibited by the waist elastic members 35 and 45, the waist portion 20 is elastic along its periphery (waist opening BH).

[0076] However, when the strong contractile force generated by the waist elastic members 35 and 45 acts on the entire area of ​​the waist portion 20 (30, 40), the contractile force throughout the entire waist portion 20 is more likely to become stronger, thus increasing the risk of discomfort to the wearer due to linear marks created by the waist elastic members 35 and 45, or discomfort due to skin pain. Therefore, in the diaper 1 of this embodiment, a region (a low-elasticity region described later) with reduced contractile force generated by the waist elastic members 35 and 45 compared to other regions is provided in at least a portion of the waist portion 20, suppressing the possibility of leaving rubber marks on the wearer's skin.

[0077] The waist elastic member 35 provided in the front waist portion 30 of the diaper 1 includes: a continuous elastic member 35s that is continuous in the transverse direction from one end (side joining portion 50) to the other end (side joining portion 50); and discontinuous elastic members 35c that are at least partially discontinuous in the transverse direction. Figure 2 In the front waist portion 30, a plurality of continuous elastic members 35s, 35s, ... are arranged in the upper region in the vertical direction, and a plurality of discontinuous elastic members 35c, 35c, ... are arranged in the region adjacent to and below the region where the continuous elastic members 35s are arranged.

[0078] Each discontinuous elastic component 35c has a discontinuous portion 61 in its central portion in the transverse direction. Figure 2 The area shown is shaded. In the discontinuous portion 61, the contractile force generated by the waist elastic member 35 is weakened or absent. That is, in the front waist portion 30, the area forming the discontinuous portion 61 is a low-elasticity region, where the contractile force generated by the waist elastic member 35 is reduced compared to other regions. In the following text, the discontinuous portion 61 will also be referred to as the front low-elasticity region 61.

[0079] For example, the front low-elasticity region 61 is formed as follows. First, in the manufacturing step of the front waist portion 30, the waist elastic member 35, which is stretched in the lateral direction, is adhered to the skin side piece 31 and non-skin side piece 32 constituting the front waist portion 30. At this time, in the area where the discontinuous portion 61 is formed, the waist elastic member 35 is not adhered to the skin side piece 31 and non-skin side piece 32. Next, near the central position in the lateral direction, the waist elastic member 35 arranged in the area overlapping with the discontinuous portion 61 is cut. Then, the cut waist elastic member 35 is contracted from the cut position to the two outer sides in the lateral direction, and then the contraction stops at the end position in the lateral direction of the discontinuous portion 61 (the position where the waist elastic member 35 is adhered). Therefore, a portion of each waist elastic member 35 (discontinuous elastic member 35c) becomes discontinuous in the lateral direction, and the front low-elasticity region 61 is formed in the discontinuous portion. Thus, the operation of forming the discontinuous portion by contracting a portion of the waist elastic member 35 is also called "backcut".

[0080] It should be noted that the front low-elasticity region 61 can be formed by methods other than backcutting. For example, the following method can be used: the waist elastic member 35 is attached by applying an adhesive to the entire front waist portion 30, and then the waist elastic member 35 is cut at multiple locations in a predetermined area (the area where the discontinuous portion 61 is to be formed), making the waist elastic member 35 discontinuous, thereby forming the front low-elasticity region 61 with reduced tensile / contraction force in the predetermined area.

[0081] exist Figure 2 In the front waist portion 30, the area that overlaps with the front low elasticity region 61 in the vertical direction and is adjacent to the two outer sides of the front low elasticity region 61 in the lateral direction is defined as the front first elasticity region 62 (in Figure 2 The middle part is the shaded area in the front waist portion 30 and has a vertical length H61. Furthermore, in the vertical direction, the adjacent area above the front low elasticity region 61 and the front first elasticity region 62 is defined as the front second elasticity region 63 (in...). Figure 2 The middle part is the bordered portion of the front waist section 30 and has a vertical length H63. The front first elastic region 62 and the front second elastic region 63 are regions in which the contraction force of the continuous elastic member 35s or the discontinuous elastic member 35c in the lateral direction is stronger than the contraction force in the front low elastic region 61.

[0082] Furthermore, similar to the front waist portion 30, the rear waist elastic member 45 provided in the rear waist portion 40 includes: a continuous elastic member 45s that is continuous in the lateral direction from one end to the other end; and a discontinuous elastic member 45c, each of which is at least partially discontinuous in the lateral direction.

[0083] Each discontinuous elastic component 45c has a discontinuous portion 71 in its central portion in the transverse direction. Figure 2 The area shown is shaded. In the discontinuous portion 71, the contractile force generated by the waist elastic member 45 is weakened or absent. That is, in the rear waist portion 40, the area forming the discontinuous portion 71 is a low-elasticity region, in which the contractile force generated by the waist elastic member 45 is weakened compared to other regions. In the following text, the discontinuous portion 71 is also referred to as the rear low-elasticity region 71. Similar to the front low-elasticity region 61, the rear low-elasticity region 71 can be formed by subjecting some of the rear waist elastic members 45 to a back-cut. However, it is not necessary to provide the rear low-elasticity region 71 in the rear waist portion 40 of the diaper 1. That is, all the rear waist elastic members 45 can be continuous elastic members 45s.

[0084] Furthermore, in the rear waist portion 40, the area that overlaps vertically with the front low elasticity region 61 is defined as the rear first elasticity region 81 (this region is in Figure 2 The shaded portion in the rear waist section 40 has a vertical length H61. Furthermore, the area vertically adjacent to and above the first rear elastic region 81 is defined as the second rear elastic region 82 (this region is in...). Figure 2 The middle part of the rear waist section 40 has a bordered portion with a vertical length H63.

[0085] Figure 5 This is a schematic cross-sectional view of diaper 1 taken in the vertical direction when diaper 1 is worn. Figure 5 It shows that in relation to Figure 4The view shows the cross-section of the waist portion 20 of the diaper 1 viewed from above in the vertical direction along arrow B at the position corresponding to the view. In the front waist portion 30, due to the elasticity generated by the discontinuous elastic member 35c provided in the front first elastic region 62, the contraction force along the wearer's waist acts more strongly in this area when the diaper 1 is put on. On the other hand, in the front low elastic region 61, the elasticity is reduced by causing some of the waist elastic members 35 to undergo back-cutting, thus weakening the contraction force along the wearer's waist. Therefore, the front low elastic region 61 is pulled to both sides in the lateral direction by the contraction force of the front first elastic region 62, so the front low elastic region 61 in the front waist portion 30 is prone to surface-to-surface contact with the wearer's skin (front side) when stretched in the lateral direction.

[0086] Similarly, in the lower back portion 40, due to the elasticity generated by the continuous elastic member 45s and the discontinuous elastic member 45c provided in the rear first elastic region 81, the contraction force along the wearer's waist acts more strongly in this region. On the other hand, in the rear low elastic region 71, the contraction force along the wearer's waist is weakened. Therefore, the rear low elastic region 71 is pulled to both sides in the lateral direction by the contraction force of the rear first elastic region 81, thus, the rear low elastic region 71 in the lower back portion 40 is more likely to make surface-to-surface contact with the wearer's skin (back side) when stretched in the lateral direction.

[0087] Figure 6A and 6B This is a schematic cross-sectional view showing the waist portion 20 of the diaper 1 in a stretched state. Figure 6A This illustrates the state in which the waist portion 20 is stretched laterally until its dimensions reach their maximum stretched state. Figure 6B This illustrates a state where the waist portion 20 is stretched laterally until its dimensions reach 70% of its maximum stretched state. Note that in... Figure 6B In the middle, the waist portion 20 is stretched in the lateral direction until the size of the waist portion 20 reaches 70% of its maximum stretched size, which refers to the state with... Figure 5 The state shown corresponds to the stretching state of the waist portion 20 when the wearer puts on the diaper 1.

[0088] exist Figure 6AIn the maximum stretch state, the skin side piece 31 and non-skin side piece 32 constituting the front waist portion 30 of the waist portion 20 are stretched in the lateral direction until the overall size of each of the pieces 31 and 32 is equal to its own size. In other words, the lateral dimension of the front waist portion 30 is equal to the size when the skin side piece 31 and non-skin side piece 32 are stretched 100% in the lateral direction. Therefore, the front low elasticity region 61 in the front waist portion 30 is also in a state of being stretched 100% in the lateral direction. Hereinafter, in the state where the waist portion 20 is stretched 100% in the lateral direction (maximum stretch state), the lateral dimension of the waist portion 20 is defined as WE100, and the lateral dimension of the front low elasticity region 61 is defined as W61.

[0089] Similarly, in the maximum stretched state, the skin side panels 41 and non-skin side panels 42 constituting the lumbar portion 40 of the waist portion 20 are stretched 100% in the transverse direction, that is, stretched until the overall size of each of the skin side panels 41 and non-skin side panels 42 is equal to its own size (WE100). Therefore, the rear low-elasticity region 71 in the lumbar portion 40 is also stretched 100% in the transverse direction. Hereinafter, the transverse dimension of the rear low-elasticity region 71 is defined as W71.

[0090] Next, in Figure 6B In the 70% stretch state, when the waist portion 20 is stretched in the lateral direction until its size reaches 70% of its maximum stretch state, the lateral dimension of the waist portion 20 is defined as WE70, which is 70% of WE100. On the other hand, regarding the front low-elasticity region 61, its maximum stretch state is maintained by stretching laterally outwards by the contraction force of the front first elasticity region 62 on both sides in the lateral direction. That is, the lateral dimension of the front low-elasticity region 61 in the 70% stretch state is equal to the dimension W61 of the front low-elasticity region 61 in the maximum stretch state.

[0091] It should be noted that the dimensions W61 of the front low elasticity region 61 in the waist portion 20 under maximum stretch (100% stretch) and 70% stretch conditions can be measured, for example, as follows. Figure 7A and 7B This is a schematic diagram illustrating an example of a method for stretching diaper 1 in the transverse direction. When stretching diaper 1 in the transverse direction, a well-known tensile testing machine (e.g., a universal testing machine manufactured by Instron) can be used.

[0092] First of all, Figure 7AIn this tensile testing machine 100, rod-shaped clamps 120A and 120B for supporting the diaper 1 are attached to the upper chuck 110 and lower chuck, respectively. The space L0 between clamps 120A and 120B is adjusted to be equal to or smaller than the transverse dimension of the waist portion 20 of the diaper 1 in its natural state. Then, the two ends of the waist portion 20 of the diaper 1 in the transverse direction are fixed to the clamps 120A and 120B, respectively, so as not to be displaced. It is desirable to provide anti-slip parts (such as rough skin-like parts) on the surface of each clamp 120A and 120B so that the diaper 1 will not shift.

[0093] like Figure 7B As shown, after placing the diaper 1 in the tensile testing machine 100, the diaper 1 is stretched at a predetermined stretching speed (e.g., 100 mm / min) until the space between clamps 120A and 120B reaches L1 (L1>L0). This operation is repeated multiple times (e.g., twice). The length of space L1 is the same as WE100 under maximum stretch (100% stretch) and WE70 under 70% stretch (see...). Figure 5 (A and 5B). Measurements were taken at the maximum stretch of diaper 1 and at 70% of the stretch corresponding to the maximum stretch. Figure 2 The length of the discontinuous portion 61 (i.e., the front low elasticity region 61) of the discontinuous elastic member 35c shown is obtained, thereby obtaining the length W61 of the front low elasticity region 61 in the lateral direction.

[0094] like Figure 6A and 6B As described, by forming a region with a size equal to its size in the maximum stretched state in a specific area of ​​the waist portion 20 of the diaper 1 located in the transverse direction outside the absorbent core 11, the waist portion 20 is made to facilitate face-to-face contact with the wearer's skin in this area. Therefore, the front low-elasticity region 61 (rear low-elasticity region 71), maintaining a flat shape, can make close contact with the wearer's body (waist) for reinforcement, preventing the waist portion from slipping. The pressure of the waist elastic members 35 and 45 is distributed in a flat plane, thus preventing the contractile force (pressure) of the waist elastic members 35 and 45 from leaving linear marks or causing pain on the wearer's skin when wearing the diaper 1. This makes it less likely for the wearer to feel discomfort. It should be noted that, in practice, the transverse dimension WE61 (WE71) of the front low-elasticity region 61 (rear low-elasticity region 71) may have an error of approximately ±5% in both the maximum stretched state and the 70% stretched state. However, an error of approximately ±5% does not detract from the aforementioned effects.

[0095] Specifically, in the front waist portion 30, the outer region of the absorbent core 11 in the lateral direction is the part that contacts the wearer's groin area when the diaper 1 is worn. When a strong contractile force acts around the groin, this force can easily cause itching or pain, making the wearer feel uncomfortable. In contrast, in the diaper 1 of this embodiment, when the diaper 1 is worn, the sheet-like component easily maintains a flat shape at the portion of the front waist portion 30 that contacts the wearer's groin area (front low elasticity region 61). This suppresses the pressure of the waist elastic component 35 (e.g., elastic cord or the like) acting locally on the groin. Therefore, strong contractile forces are not easily generated around the groin, thus reducing the likelihood of discomfort for the wearer.

[0096] In the front waist portion 30, first front elastic regions 62 that stretch and contract in the lateral direction are provided on both sides of the front low elastic region 61, which is in its maximum stretch state. When the diaper 1 is put on, the front low elastic region 61 is pulled to both sides in the lateral direction by the contraction force of the first front elastic regions 62, and comes into close contact with the wearer's skin for reinforcement and tightening. Therefore, even when the contraction force in the lateral direction acting on the front low elastic region 61 itself is small, it is easy to prevent the front low elastic region 61 from slipping off the wearer's skin. Therefore, it is easy to maintain a good fit, and the wearer is less likely to feel discomfort.

[0097] Furthermore, similar to the front low-elasticity region 61 of the front waist portion 30, the rear low-elasticity region 71 of the rear waist portion 40 has a lateral dimension in the 70% stretch state equal to the lateral dimension W71 in the maximum stretch state. That is, a region is formed in the rear waist portion 40 in a specific area located laterally outside the absorbent core 11, having a dimension equal to its maximum stretch state, and within this region, the rear waist portion 40 readily makes face-to-face contact with the wearer's skin.

[0098] The area of ​​the lower back portion 40 located laterally outside the absorbent core 11 is the part that contacts the buttocks when the diaper 1 is worn, where the buttocks are more prone to sweating than the front. Therefore, when the lower back portion 40 contracts in this area, a space is created between the wearer's skin and the sheet component, making it easy for heat to remain trapped. This poses a risk of causing stuffiness and rashes. In contrast, in the diaper 1 of this embodiment, the sheet component easily maintains a flat shape in the part that contacts the sweaty buttocks when the diaper is worn (the rear low-elasticity area 71). This makes it less likely for heat to remain trapped and allows sweat to evaporate effectively from the surface of the sheet component. This suppresses stuffiness and rashes in the buttocks, making the wearer less likely to feel discomfort.

[0099] Furthermore, when using a perforated nonwoven fabric with multiple through-holes as the non-skin side panel 42 constituting the back waist portion 40, it is recommended that at least some of the through-holes be arranged at locations overlapping with the rear low-elasticity region 71. That is, when the waist portion 20 is in a 70% stretched state, it is recommended that through-holes penetrating the non-skin side panel 42 in the thickness direction be provided in such a region of the non-skin side panel 42, the size of which is equal to its size in the maximum stretched state, and does not overlap with the absorbent core 11. When the diaper 1 is worn, the back waist portion 40 (waist portion 20) stretches and contracts in the lateral direction. However, even during this stretching and contraction, the rear low-elasticity region 71 easily maintains its maximum stretched state and flat shape. Therefore, the through-holes provided in the rear low-elasticity region 71 are not easily contracted in the lateral direction, thus easily maintaining the shape of the holes. Therefore, breathability and evaporation functions are not easily compromised. Furthermore, this improves the visibility of the through-holes when viewed from the outside (non-skin side), and makes it easy for the user to associate with good breathability.

[0100] Furthermore, when the diaper 1 is stretched to 70%, if the width in the lateral direction of the area (low elasticity area) of either the front waist portion 30 or the back waist portion 40 under maximum stretch is greater than the width in the lateral direction of the area (low elasticity area) of the other waist portion under maximum stretch, it is desirable that the contraction force in the lateral direction of the other waist portion is greater than the contraction force in the lateral direction of either waist portion. The term "contraction force" here refers to the force generated when the elastic element attempts to return to its original state from a stretched state.

[0101] For example, in Figure 6B In the former, the width W61 of the front low-elasticity region 61 in the front waist portion 30 is greater than the width W71 of the rear low-elasticity region 71 in the rear waist portion 40. In this case, the contraction force in the lateral direction of the rear waist portion 40 is preferably greater than the contraction force in the lateral direction of the front waist portion 30. It should be noted that the present invention also includes the case where the width W61 of the front low-elasticity region 61 or the width W71 of the rear low-elasticity region 71 is zero, that is, the case where no low-elasticity region is provided on either the rear or front side.

[0102] In this configuration, when the diaper 1 is worn, the front waist portion 30 is easily pulled laterally to both sides by the contractile force of the back waist portion 40. Therefore, the wide, low-elasticity front area 61 easily maintains a flat shape. Furthermore, with... Figure 6BConversely, when the width W61 of the front low-elasticity region 61 in the front waist portion 30 is smaller than the width W71 of the rear low-elasticity region 71 in the rear waist portion 40, the lateral contraction force of the front waist portion 30 is greater than that of the rear waist portion 40. In this case, since the rear waist portion 40 is easily pulled laterally by the contraction force of the front waist portion 30, the rear low-elasticity region 71 tends to maintain a flat shape. This makes it easier to prevent the waist elastic components 35 and 45 or similar components from leaving linear marks on the wearer's skin and / or causing pain.

[0103] The lateral contraction force of the front waist portion 30 and the rear waist portion 40 can be measured using the tensile testing machine 100 described in Figure 7. For example, in the waist portion 20, a pair of side-joined portions 50, 50 are peeled off, at the center position CL in the length direction (see Figure 7). Figure 2 The absorbent body 10 is cut at [location missing], separating the front waist portion 30 and the rear waist portion 40 to prepare a sample for tensile testing. Then, the two ends of the sample (front waist portion 30 and rear waist portion 40) in the lateral direction are held by upper and lower chucks 110 (where clamps 120A and 120B are removed). The two ends in the lateral direction are pulled in the same manner as described above until the distance between upper and lower chucks 110 reaches WE70 (70% tension), and the force at this point is measured. By performing such a tensile test, the magnitude of the contraction force between the front waist portion 30 and the rear waist portion 40 can be compared.

[0104] When the lateral contraction force of the lower back portion 40 is greater than the lateral contraction force of the front back portion 30, the lateral contraction amount of the lower back portion 40 is greater than the lateral contraction amount of the front back portion 30. In this case, such as Figure 5 As shown in Figure 6, the positions of the side joining portions 50 and 50 of the waist portion 20 are shifted rearward in the forward-rear direction. That is, at a specific position in the vertical direction, the shortest distance along the surface of the front waist portion 30 from the first side joining portion 50 to the second side joining portion 50 is longer than the shortest distance along the surface of the rear waist portion 40 from the first side joining portion to the second side joining portion. Figure 6BIn the case of the front waist portion 30, the distance between the side joint portion 50 on one side and the side joint portion 50 on the other side (W62+W61+W62) is longer than the distance between the side joint portion 50 on one side and the side joint portion 50 on the other side (W40) along the surface of the rear waist portion 40. Therefore, compared to the rear waist portion 40, the front waist portion 30 has a larger contact area with the wearer's skin, and the portion of the front waist portion 30 in its maximum stretch state (the front low-elasticity area 61) easily makes wider contact with the wearer's skin. This makes it easier to prevent the lumbar elastic component 35 or similar components from leaving linear marks and / or causing pain.

[0105] In addition, the positions of the side joining portions 50 and 50 are shifted backward in the front-back direction, so that when wearing diaper 1, the wearer's buttocks are easily covered by the lower back portion 40. Figure 8A This is a schematic diagram showing the wearer wearing a traditional underwear-like diaper 2 (comparative example). Figure 8B This is a schematic diagram showing the state of a wearer wearing the underwear-shaped diaper 1 of this embodiment.

[0106] exist Figure 8A In the comparative example of the panty-like diaper 2 shown, the lateral contraction force acts evenly on the front waist portion 30 and the back waist portion 40, so that during use, the side joining portion 50 is located at the center position in the front-to-back direction. In this state, the lateral length of the back waist portion 40 (the distance between the side joining portions 50 and 50) is defined as W40A, and the angle between the tangential direction and the horizontal direction of the end edge portion of the buttock cover 40b is defined as θ1.

[0107] In contrast, Figure 8B In the diaper 1 shown, the position of the side joining portion 50 shifts backward in the front-to-back direction during use. In this case, the length W40B (the distance between the side joining portions 50 and 50) in the lateral direction of the back waist portion 40 becomes greater than... Figure 8A W40A is shorter (W40A > W40B). Therefore, compared with... Figure 8A In comparison, the length of the buttock cover 40b in the lateral direction is also shorter, and the angle θ2 formed between the tangent direction and the horizontal direction of the end edge portion of the buttock cover 40b becomes larger than the angle θ1 in the comparative example (θ1<θ2). Therefore, in the back waist portion 40 of the diaper 1, the wearer's buttocks are more easily covered more deeply by the buttock cover 40b, thereby enhancing the fit around the wearer's buttocks.

[0108] Furthermore, the waist portion 20 of the diaper 1, in at least a portion of the area located outside the absorbent core 11 in the transverse direction, has a non-jointed portion where the skin side piece 31 (41) and the non-skin side piece 32 (42) are not joined to each other. Figure 3 In the front low elasticity region 61 (the region in the maximum stretch state), the skin side piece 31 and the non-skin side piece 32 constituting the front waist portion 30 are not joined to each other, and the non-jointed portion spans the entire front low elasticity region 61 in the lateral direction. Figure 2 The area (represented by W61) is positioned as follows. As described above, in the front low-elasticity region 61, the area located outside the absorbent core 11 in the lateral direction is the area where the skin side piece 31 in the front waist portion 30 easily makes face-to-face contact with the wearer's skin. Since the skin side piece 31 is not engaged with the non-skin side piece 32 in this region, the flexibility of the skin side piece 31 is increased compared to the case where the skin side piece and the non-skin side piece are engaged in this region. Therefore, when wearing the diaper 1, the texture of the skin side piece 31 near the wearer's groin can be enhanced. In addition, the flexibility of the non-skin side piece 32 is also enhanced in this region, and the tactile feel from the outside becomes soft, which makes it easier to give the wearer and others the impression that the diaper 1a is soft.

[0109] Furthermore, regarding the joining waist portions 20 (30, 40) and the main body joining portions 23 and 24 of the absorbent body 10, it is desirable that, in the areas overlapping with the main body joining portions 23 and 24 respectively when viewed along the thickness direction, the 5% tensile strength of the skin side sheet 31 (41) in the vertical direction is greater than the 5% tensile strength of the non-skin side sheet 32 ​​(42) in the vertical direction (longitudinal direction). Here, the "5% tensile strength" of the sheet member in the vertical direction refers to the tensile strength of the sheet member when it is stretched by an additional 5% length in the vertical direction from its maximum stretched state. That is, it represents the magnitude of the force acting in the vertical direction on a unit length area in the transverse direction when the sheet member is stretched by 5% from its maximum stretched state. Therefore, the fact that the 5% tensile strength of the skin side sheet 31 (41) in the vertical direction is greater than the 5% tensile strength of the non-skin side sheet 32 ​​(42) in the vertical direction means that the skin side sheet 31 (41) is less easily stretched in the vertical direction.

[0110] When diaper 1 is worn, the absorbent body 10 increases in weight and tends to sag vertically as it absorbs urine and other excretions. At this time, the skin side piece 31 (41) is pulled downwards by the absorbent body 10 at the portion where it engages with the absorbent body 10 via the body engagement portion 23 (24). Therefore, if the 5% tensile strength of the skin side piece 31 (41) in the vertical direction is low, the skin side piece 31 (41) will be pulled downwards and stretched vertically as the weight of the absorbent body 10 increases, potentially causing the skin side piece 31 (41) to lose its planar shape or resulting in poor fit of diaper 1. In contrast, if the 5% tensile strength of the skin side piece 31 (41) in the vertical direction is maximized, even when the weight of the absorbent body 10 increases and the skin side piece 31 (41) is pulled downward through the body joint portion 23 (24), the skin side piece 31 (41) easily resists the pulling force and easily maintains its planar shape, thereby more easily suppressing the deterioration of the fit of the diaper 1. This easily suppresses the linear marks left by the waist elastic component 35 or similar components and / or the pain caused. In this embodiment, since spunbond nonwoven fabric is used as the non-skin side piece 32 (42) and SMS nonwoven fabric with relatively higher tensile strength than spunbond nonwoven fabric is used as the skin side piece 31 (41), the above relationship is easily achieved.

[0111] Furthermore, it is desirable that the 5% tensile strength in the vertical direction is higher than the 5% tensile strength in the horizontal direction in both the skin side panel 31 (41) and the non-skin side panel 32 (42). In other words, it is desirable that the sheet-like component constituting the waist portion 20 is less likely to be stretched in the vertical direction than in the horizontal direction. With this configuration, even if the waist portion 20 is pulled downward in the vertical direction as the weight of the absorbent body 10 increases, the sheet-like component itself is not easily stretched in the vertical direction, thus preventing the waist portion 20 from sliding down as a whole. On the other hand, since the waist portion 20 is more easily stretched in the horizontal direction than in the vertical direction, the waist can easily conform to the wearer's waist according to the stretching and contraction of the waist elastic components 35 and 45 in the horizontal direction.

[0112] Note that tensile strength can be measured using the tensile testing machine 100 shown in Figure 7. For example, a sample is prepared by peeling off the skin side piece 31 and the non-skin side piece 32 from the front waist portion 30 and cutting a strip-shaped test piece with a predetermined width in the transverse direction from each of the skin side piece 31 and the non-skin side piece 32. Then, the measurement is performed by simply holding the two ends of the sample in the vertical direction with the chucks 110 and 110 of the tensile testing machine 100, measuring and comparing the magnitude of the force when the sample is stretched in the vertical direction until its length reaches 105% of the maximum tensile state.

[0113] Furthermore, it is expected that in the lower back portion of 40, in Figure 2 The contraction force in the rear first elastic region 81, acting on a unit length region along the vertical direction, is greater than the contraction force in the rear second elastic region 82, acting on a unit length region along the vertical direction. The rear first elastic region 81 is positioned relative to the vertical direction, overlapping with the front low elastic region 61. Figure 2 Within the range of H61. Therefore, the greater the lateral contraction force in the rear first elastic region 81, the easier it is for the front low elastic region 61 to be stretched and widened in the lateral direction. Therefore, by making the lateral contraction force in the rear first elastic region 81 stronger than the lateral contraction force in the rear second elastic region 82, the front low elastic region 61 is more likely to maintain a flat shape, thereby preventing the waist elastic component 35 from leaving marks on the wearer's skin.

[0114] The shrinkage force in the first rear stretchable region 81 and the second rear stretchable region 82 can be measured by cutting a strip sample with a predetermined length in the vertical direction and extending in the transverse direction from the corresponding region, and performing a tensile test on the sample using the tensile testing machine 100 described above.

[0115] Furthermore, it is desired that the lateral contraction force acting on a unit length region in the vertical direction of the rear first elastic region 81 of the rear waist portion 40 is greater than the lateral contraction force acting on a unit length region in the vertical direction of the front low elastic region 61 and the front first elastic region 62 of the front waist portion 30. In this configuration, Figure 2 Within the vertical range of H61, the lateral contractile force acting on the waist portion 20 increases in the following order: the front low-elasticity region 61, the front first elasticity region 62, and the rear first elasticity region 81. That is, the lateral contractile force acting on the waist portion 20 gradually increases along the waist from the front to the back. This, for example, makes it less likely to cause discomfort to the wearer's skin due to sudden changes in the contractile force in the waist portion of the diaper 1. It should be noted that the contractile force in each region is measured using a tensile testing machine 100, and in essentially the same manner as described above.

[0116] Furthermore, it is desirable that the average vertical spacing of the continuous elastic members 35s arranged in the front second elastic region 63 in the front waist portion 30 of the diaper 1 is greater than the average vertical spacing of the discontinuous elastic members 35c arranged in the front first elastic region 62. The larger the vertical spacing of the front waist elastic members 35, the smaller the total contact area between the front waist elastic members 35 and the wearer's skin in that area. Therefore, when wearing the diaper 1, linear marks from the front waist elastic members 35 are less likely to remain on the wearer's skin. Thus, by increasing the spacing of the continuous elastic members 35s in the front second elastic region 63, marks from the front waist elastic members 35 are less likely to remain on the entire front waist portion 30 (including the front low elastic region 61 and the front second elastic region 63 adjacent to and above the front low elastic region 61). Furthermore, this also makes the wearer less likely to experience discomfort.

[0117] However, contrary to the above configuration, the average vertical spacing of the discontinuous elastic members 35c arranged in the first elastic region 62 at the front can be set to be greater than the average vertical spacing of the continuous elastic members 35s arranged in the second elastic region 63 at the front. In this case, the marks of the elastic members 35 at the front waist are less likely to be left on the wearer's skin in the first elastic region 62 at the front, and therefore the marks of the elastic members 35 at the front waist are less likely to be left in the lower region of the front waist portion 30 (including the front low elastic region 61) in the vertical direction. That is, when wearing the diaper 1, the marks of the elastic members 35 at the front waist are less likely to be left on sensitive skin areas such as the legs and groin.

[0118] Furthermore, it is desirable that the average vertical spacing of the elastic members 45 arranged in the rear first elastic region 81 in the rear waist portion 40 is narrower than the average vertical spacing of the elastic members 45 arranged in the rear second elastic region 82. With this configuration, the contractile force of the elastic members 45 acting on the rear first elastic region 81 is more likely to be greater than the contractile force of the rear second elastic region 82 by an amount corresponding to the narrower spacing. Therefore, the front low elastic region 61 and the front first elastic region 62 are easily pulled laterally by the rear first elastic region 81. This makes the rear first elastic region 81 less prone to loosening when wearing the diaper 1 and more likely to maintain its planar shape.

[0119] Furthermore, such as Figure 4As shown, in the lateral direction, one end 61es1 of the front low-elasticity region 61 is located on one side of the rising point 15es1 relative to one side of the leak-proof wall portion 15, and the other end 61es2 of the front low-elasticity region 61 is located on the other side of the rising point 15es2 relative to the other side of the leak-proof wall portion 15. That is, in the front waist portion 30, the lateral width W61 of the front low-elasticity region 61 is greater than the lateral distance W15 between the rising points 15es and 15es of the leak-proof wall portion 15 (W61>W15). Therefore, when wearing the diaper 1, the contractile force generated by the waist elastic member 35 is less likely to act on the leak-proof wall portion 15, and this makes it easier for the pair of leak-proof wall portions 15 to maintain an upward state while maintaining the distance W15, without causing the leak-proof wall portions 15 to fold and deform. This makes it less likely for the wearer to feel discomfort and makes it easier to suppress lateral leakage of excrement.

[0120] In addition, such as Figure 2 As shown, in the lateral direction, one end 61es1 of the front low-elasticity region 61 is located on one side relative to one end 10es1 of the absorbent body 10, and the other end 61es2 of the front low-elasticity region 61 is located on the other side relative to the other end 10es2 of the absorbent body 10. That is, in the front waist portion 30, the width W61 of the front low-elasticity region 61 in the lateral direction is greater than the width W10 of the absorbent body 10 in the lateral direction (W61>W10). The two ends 10es1 and 10es2 in the lateral direction of the absorbent body 10 respectively form part of the corresponding leg opening LH of the diaper 1 and are easily pressed against the wearer's groin. Therefore, when the waist elastic member 35 is arranged to overlap with the two ends 10es1 and 10es2 in the lateral direction of the absorbent body 10, the waist elastic member 35 is easily pressed against the skin near the wearer's legs, and there is a risk of rubber marks easily forming. In contrast, in the diaper 1 of this embodiment, the contractile force generated by the waist elastic member 35 is less likely to act on the two ends 10es1 and 10es2 in the transverse direction of the absorbent body 10 and the area outside them, and therefore is less likely to form rubber marks in the area around the wearer's legs.

[0121] However, the lateral extent of the front low-elasticity region 61 can be modified as follows. Figure 9 This is a schematic diagram showing a modified example of the front low-flexibility region 61. Figure 9 Is with Figure 2 The corresponding diagram shows the diaper 1 when unfolded and at its maximum stretch. Figure 9In the modification example, in the lateral direction, one end 61es1 of one side of the front low stretchability region 61 is located on the other side with respect to one end 10es1 of one side of the absorbent body 10, and is located on one side with respect to one end 11es1 of one side of the absorbent core 11. The other end 61es2 of the other side of the front low stretchability region 61 is located on one side with respect to the other end 10es2 of the other side of the absorbent body 10, and is located on the other side with respect to the other end 11es1 of the absorbent core 11. In this case, some front waist elastic members 35 are arranged to overlap with the two ends in the lateral direction of the absorbent body 10. Therefore, in the overlapping portion, due to the contraction force generated by the front waist elastic members 35, the absorbent body 10 is pressed against the skin of the wearer. This makes it less likely to leave rubber marks around the wearer's legs, while enhancing the fit of the absorbent body 10.

[0122] Subsequently, in Figure 2 in the region in the lateral direction between the outer end 10es (for example, the other end 10es2 in the lateral direction) of the absorbent body 10 and the side joining portion 50 (the side joining portion 50 on the other side in the lateral direction), it is desirable that the width W61s in the lateral direction of the front low stretchability region 61 is narrower than the width W62s of the front first stretchability region 62 adjacent to the front low stretchability region 61 in the lateral direction and located outside it (W61s < W62s). In the front waist portion 30, the front low stretchability region 61 is set to be wider, which makes the overall contraction force weaker and there is a risk that the fit on the front side of the wearer is insufficient. Therefore, in the regions on both sides in the lateral direction of the front low stretchability region 61, the front first stretchability region 62 is made larger than the front low stretchability region 61, which makes it easier for the contraction force of the waist elastic member 35 to act. Therefore, compared with the case where the front first stretchability region 62 is narrower than the front low stretchability region 61, the deterioration of the fit of the front waist portion 30 on the front side of the wearer can be suppressed, while making it less likely to leave rubber marks.

[0123] However, a structure where the width W61s in the lateral direction of the front low stretchability region 61 is greater than the width W62s of the front first stretchability region 62 adjacent to the outside of the front low stretchability region 61 in the lateral direction (W61s > W62s) can also be adopted. According to the above structure, since the contraction force acting on the front waist portion 30 is smaller compared with the above case, the absorbent body 10 can be made less likely to contract. In addition, the range where the contraction force generated by the waist elastic member 35 is less likely to act becomes larger on both sides in the lateral direction of the absorbent body 10, so it can be made less likely to form rubber marks in the skin around the legs on the front side of the wearer.

[0124] In addition, as Figure 2 As shown, it is desirable that the vertical length H61 of the front low-elasticity region 61 is longer than the vertical length H63 of the front second elasticity region 63 adjacent to and above the front low-elasticity region 61 (H61>H63). In other words, in the front waist portion 30, it is desirable that the vertical length (corresponding to H61) of the portion forming the front low-elasticity region 61 is longer than the vertical length (corresponding to H63) of the portion not forming the front low-elasticity region 61. Therefore, within a larger range in the vertical direction of the front waist portion 30, the lateral contraction force caused by the waist elastic member 35 is reduced, the absorbent core 11 is less prone to contraction, and rubber marks are less likely to form on the wearer's skin.

[0125] On the other hand, with Figure 2 Conversely, the vertical length H61 of the front low-elasticity region 61 can be equal to or less than the vertical length H63 of the front second elasticity region 63 (H61 ≤ H63). In other words, in the front waist portion 30, the vertical length (corresponding to H61) of the portion forming the front low-elasticity region 61 can be equal to or less than the vertical length (corresponding to H63) of the portion not forming the front low-elasticity region 61. With the above configuration, the contractile force of the waist elastic member 35 acting on the front waist portion 30 can be increased compared to the case where the length H61 is greater than the length H63. For example, when the diaper size is large or it is desirable to prevent the fit around the wearer's waist from deteriorating, it is desirable for the front waist portion 30 to have a certain degree of elasticity. Therefore, in this case, by adjusting the length to satisfy H61 ≤ H63, positional shift and deterioration of fit when wearing the diaper 1 can be suppressed.

[0126] Other implementation plans

[0127] While embodiments of the present invention have been described above, these embodiments are merely for the purpose of facilitating understanding of the invention and are not intended to limit the interpretation of the invention. Furthermore, modifications or improvements can be made to the present invention within the scope of its spirit, and, needless to say, equivalents are also included in the present invention.

[0128] In diaper 1, the areas of the front waist portion 30 and the back waist portion 40 can be adjusted such that the area ratio of the front waist portion 30 to the back waist portion 40 is within a predetermined range. For example, when the area of ​​the front waist portion 30 is between 30 and 50, it is desirable that the area of ​​the back waist portion 40 is between 50 and 70, and more preferably, the area ratio of the front waist portion 30 to the back waist portion 40 is 35:65. By making the area of ​​the back waist portion 40 larger than the area of ​​the front waist portion 30, even when the stress in the back waist portion 40 is high, the contractile pressure can be reduced, making it less likely to cause discomfort to the wearer.

[0129] In the above embodiment, an example is described where, in the waist portion 20 of the diaper 1, because the back waist portion 40 is more constricted in the lateral direction (waist circumference direction) compared to the front waist portion 30, the side joining portions 50 and 50 are displaced rearward in the front-back direction (see...). Figure 5 (etc.). However, a structure can also be adopted in which the front waist portion 30 is more tapered than the rear waist portion 40, and the side joining portions 50 and 50 are shifted forward in the front-rear direction. In this case, it is desirable that the width of the rear low-elasticity region 71 in the lateral direction is greater than the width of the front low-elasticity region 61 in the lateral direction. With this configuration, the same effect as that obtained on the front side in the above embodiment can be obtained on the rear side.

[0130] List of reference numerals

[0131] 1. Diaper (disposable diaper in the shape of underwear),

[0132] 2. Diapers (underwear-like disposable diapers) (comparative example)

[0133] 10 Absorbent Subjects

[0134] 11 absorption core, 11b packaged chip,

[0135] 12 films,

[0136] 13 Backing film, 13a Liquid-impermeable film, 13b External film,

[0137] 15 Leak-proof wall section, 16 Leak-proof wall elastic component, 17 Leg elastic component,

[0138] 20 Waist section,

[0139] 23 Main body joint portion, 24 Main body joint portion,

[0140] 30. Front waist section, 30. SW side section, 31. Side skin patch.

[0141] 32 non-skin side, 32f folded-back portion,

[0142] 35. Waist elastic component (front waist elastic component)

[0143] 35s continuous elastic component, 35c discontinuous elastic component.

[0144] 36 skin surface slices,

[0145] 40. Lower back area

[0146] 40b hip cover, 40sw side section,

[0147] 41 Skin side view, 42 Non-skin side view, 42f Folded-back portion,

[0148] 45. Elastic waist support (lower back elastic support).

[0149] 45s continuous elastic component, 45c discontinuous elastic component.

[0150] 50 Side joint portion,

[0151] 61. Front low-elasticity area (discontinuous portion),

[0152] 62 Front first elastic region, 63 Front second elastic region,

[0153] 71. Rear low-elasticity area (discontinuous portion),

[0154] 81 Rear first elastic region, 82 Rear second elastic region,

[0155] 100 Tensile Testing Machine

[0156] 110 chuck,

[0157] 120A and 120B fixtures

[0158] BH waist opening, LH leg opening

[0159] CL center position (longitudinal direction, length direction)

Claims

1. A disposable diaper in the shape of underwear, the disposable diaper having intersecting vertical, horizontal and front-back directions, the disposable diaper comprising: An absorbent body, the absorbent body comprising a liquid-absorbent core; as well as The waist section is capable of stretching and contracting in the lateral direction. The maximum stretch state is defined as the stretch state of the waist portion when it is stretched in the lateral direction until its size reaches the size of the sheet-like component constituting the waist portion. When the waist portion is stretched in the lateral direction until its size reaches 70% of the size of the sheet-like component, the waist portion has a region in the maximum stretch state within at least a portion of the portion located outside the absorbent core in the lateral direction. The waist section includes a front waist section and a rear waist section, and If the width in the lateral direction of the area in the maximum stretched state of either the front waist portion or the rear waist portion is greater than the width in the lateral direction of the area in the maximum stretched state of the other waist portion, then the contractile force in the lateral direction of the other waist portion is greater than the contractile force in the lateral direction of the first waist portion.

2. The disposable diaper in the shape of underwear according to claim 1, wherein, When the waist portion is stretched in the lateral direction until the size of the waist portion reaches 70% of the size of the sheet member itself, the front waist portion has a region in the maximum stretched state in at least a portion of the portion located outside the absorbent core in the lateral direction.

3. The disposable diaper in the shape of underwear according to claim 1 or 2, wherein, When the waist portion is stretched in the lateral direction until the size of the waist portion reaches 70% of the size of the sheet member itself, the rear waist portion has a region in the maximum stretched state in at least a portion of the portion located outside the absorbent core in the lateral direction.

4. The disposable diaper in the shape of underwear according to claim 3, wherein, The lower back portion includes: a skin side panel; and a non-skin side panel covering the non-skin side of the skin side panel, and At least a portion of the region of the non-skin side sheet in the maximum stretched state is provided with a through hole penetrating the non-skin side sheet in the thickness direction.

5. The disposable diaper in the shape of underwear according to claim 1, wherein, On each side of the region in the waist portion that is in the maximum stretched state, there is a stretchable area that can stretch and contract in the lateral direction.

6. The disposable diaper in the shape of underwear according to claim 1, wherein, The waist portion has skin side pieces and non-skin side pieces that overlap in the thickness direction, and In at least a portion of the portion located on the outer side of the absorbent core in the lateral direction, the waist portion has a non-jointed portion in the region of maximum stretch, the non-jointed portion being the portion where the skin side piece and the non-skin side piece do not join to each other.

7. The disposable diaper in the shape of underwear according to claim 6, wherein, The panty-like disposable diaper further includes a body engagement portion that engages the waist portion to the non-skin side of the absorbent body, and In the region overlapping with the main body when viewed along the thickness direction, the tensile strength of the skin side piece, which is in its maximum stretched state and further stretched by 5% in the vertical direction, is greater than the tensile strength of the non-skin side piece, which is in its maximum stretched state and further stretched by 5% in the vertical direction.

8. A disposable diaper in the shape of underwear, the disposable diaper having intersecting vertical, horizontal and front-back directions, the disposable diaper comprising: An absorbent body, the absorbent body comprising a liquid-absorbent core; as well as The waist section is capable of stretching and contracting in the lateral direction. The maximum stretch state is defined as the stretch state of the waist portion when it is stretched in the lateral direction until its size reaches the size of the sheet-like component constituting the waist portion. When the waist portion is stretched in the lateral direction until its size reaches 70% of the size of the sheet-like component, the waist portion has a region in the maximum stretch state within at least a portion of the portion located outside the absorbent core in the lateral direction. The waist portion has a front waist portion and a rear waist portion. A pair of side joining portions are disposed at both ends in the lateral direction, the pair of side joining portions circumferentially connecting the front waist portion and the rear waist portion, and At a location in the vertical direction where the front low elasticity region of the front waist portion and the rear low elasticity region of the rear waist portion are provided, the shortest distance along the surface of the front waist portion from one side joint to the other side joint is longer than the shortest distance along the surface of the rear waist portion from the other side joint.

9. The disposable diaper in the shape of underwear according to claim 1, wherein, The front waist portion has a low-elasticity front area with reduced elasticity compared to other areas. The lower back portion has a first rear elastic region and a second rear elastic region. The first rear elastic region is the area that overlaps with the front low elastic region in the vertical direction. The second rear elastic region is the area adjacent to and above the first rear elastic region. The contractile force in the first rear elastic region acting on a unit length of area along the vertical direction is greater than the contractile force in the second rear elastic region acting on a unit length of area along the vertical direction.

10. The disposable diaper in the shape of underwear according to claim 9, wherein, The front waist portion has a first front elastic region, which is a region that overlaps with the first front elastic region in the vertical direction and is adjacent to both sides of the first front elastic region in the lateral direction. The contractile force in the lateral direction acting on a unit length of area in the vertical direction in the rear first elastic region is greater than the contractile force in the lateral direction acting on a unit length of area in the vertical direction in the front low elastic region and the front first elastic region.

11. The underwear-shaped disposable diaper according to claim 9 or 10, wherein, The front waist portion has a first front elastic region and a second front elastic region. The first front elastic region is the area that overlaps with the lower front elastic region in the vertical direction and is adjacent to both sides of the lower front elastic region in the lateral direction. The second front elastic region is the area that is adjacent to and above the lower front elastic region and the first front elastic region in the vertical direction. Each of the first and second front elastic regions is provided with multiple linear elastic elements, and The vertical spacing of the linear elastic elements arranged in the second elastic region at the front is greater than the vertical spacing of the linear elastic elements arranged in the first elastic region at the front.

12. The underwear-shaped disposable diaper according to claim 9 or 10, wherein, Each of the first and second rear elastic regions is provided with multiple linear elastic components, and The vertical spacing of the linear elastic members arranged in the second elastic region at the rear is greater than the vertical spacing of the linear elastic members arranged in the first elastic region at the rear.

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