Underpants-type absorbent article

Abstract

[Problem] To provide an underpants-type absorbent article that makes it easy for legs to pass through leg openings and is easy to wear. [Solution] The problem is solved by an underpants-type disposable diaper in which: first side regions S1 and second side regions S2 in a front body F and a back body B are stretchable regions that elastically stretch, together with a lower-waist elastic member 16, between a natural length state and a state in the maximum stretch rate of 150-300%; a first central region M1 in the back body B is a non-stretchable region having the maximum stretch rate of 110% or less; a first central region M1 in the front body F is a stretchable region that elastically stretches, together with the lower-waist elastic member 16, between a natural length state and a state in the maximum stretch ratio of 0.7-1 times that of the first side region S1 and the second side region S2 in the front body F, and has a portion having the maximum width 220 of an interior body 200 in a lower region U2 of the back body B in the natural length state; and the width 210 of the interior body 200 in the lower region U2 of the front body F is 0.5-0.9 times the maximum width 220 of the interior body 200.

Description

Pants-type absorbent articles

[0001] The present invention relates to a pants-type absorbent article such as a pants-type disposable diaper.

[0002] In pants-type absorbent articles, it is common to ensure a good fit to the body surface by adding elasticity to various components. For example, many pants-type absorbent articles include an outer body that is an integral unit extending from the front to the back, or an outer body that is provided separately for the front and back, an inner body that is provided in the widthwise middle of the front and back, an absorbent body contained in the inner body that extends from the front to the back, and an inner body fastening portion that fastens the inner body to the outer body. Side seals are formed by joining both sides of the outer body in the front and both sides of the outer body in the back, thereby forming a waist opening and a pair of left and right leg openings. In such pants-type absorbent articles, an elastic member is provided in the torso region between one side seal and the other side seal of the outer body, allowing the torso-forming region of the pants-type absorbent article to stretch in the width direction and fit the torso of the wearer. (See, for example, Patent Documents 1 to 3.)

[0003] However, conventional pants-type absorbent articles have room for improvement in terms of achieving both a good fit of the inner body in the front and a good fit of the inner body in the back. In particular, since this type of product is subject to constraints on manufacturing methods and costs, it is desirable to improve the fit with a simple structure.

[0004] JP 2014-200524 A JP 2010-264042 A Japanese Patent No. 4986461 A

[0005] Therefore, a main object of the present invention is to achieve good fit of the inner body in both the front and rear body sections with a simple structure.

[0006] A pants-type absorbent article that solves the above problems is as follows: <First Aspect> An outer body that is an integral body extending from a front body to a rear body, or an outer body that is provided separately for the front body and the rear body, an inner body that extends from a widthwise intermediate portion of the front body through the crotch portion to a widthwise intermediate portion of the rear body, an absorbent body that is built into the inner body so as to extend from a widthwise intermediate portion of the front body through the crotch portion to a widthwise intermediate portion of the rear body, an inner body fastening portion that fastens the inner body to the outer body, side seals that join both side ends of the outer body on the front body to both side ends of the outer body on the rear body, a waist opening and a pair of left and right leg openings, wherein the outer body on the front body and the outer body on the back body each have a torso region that is defined as a region between one of the side seals and the other of the side seals, the torso region comprises a waist portion extending from one side seal to the other side seal along the edge of the waist opening, and a lower waist portion adjacent to the lower part of the waist portion and extending from one side seal to the other side seal, the lower waist portion comprising an upper region above a boundary line passing through the edge of the waist opening side of the absorbent body and extending in the width direction, and a lower region below the boundary line, the lower region having a first central region overlapping with the interior fastening part, a first side region defined as the region between one of the side seals and the first central region, and a second side region defined as the region between the other side seal and the first central region, the first side region and the second side region in the front body and the first side region and the second side region in the back body having elastic members and being stretchable regions that stretch and contract between a natural length state in which they are contracted in the width direction together with the elastic members and an expanded state in which they are stretched in the width direction together with the elastic members to a maximum stretch rate of 150 to 300%,the first central region of the rear body is a non-elastic region having a maximum widthwise extension rate of 110% or less, the first central region of the front body has an elastic member and is an elastic region that elastically stretches and contracts between a natural length state in which it contracts in the widthwise direction together with the elastic member and an expanded state in which it stretches in the widthwise direction together with the elastic member to a maximum extension rate that is 0.7 to 1 times that of the first side region and the second side region of the front body, and wherein in the natural length state, the inner body has a maximum width portion in the lower region of the rear body, and the width of the inner body in the lower region of the front body is 0.5 to 0.9 times the maximum width of the inner body.

[0007] (Effects) In this pants-type absorbent article, the entire width of the lower region of the front outer body is a stretchable region, while the first central region of the lower region of the back outer body is a non-stretchable region. This allows the inner body to have its widest portion in the lower region of the back body when in its natural length, and the width of the inner body in the lower region of the front body is 0.5 to 0.9 times the maximum width of the inner body. As a result, when worn, the widest portion of the inner body in the rear body extends to cover the left and right bulges of the wearer's buttocks, providing a good fit. Furthermore, when the pants-type absorbent article is pulled up through the legs, the rear body is less likely to get caught on the bulges of the buttocks, improving ease of wear. Meanwhile, because the first central region of the front body is a stretchable region, the width of the inner body in the lower region of the front body does not unnecessarily widen, providing a good fit between the wearer's groin. Therefore, it is possible to achieve both a good fit of the inner body in both the front and back body. Moreover, this level of fit can be achieved with a simple structure that involves the arrangement of stretchable and non-stretchable regions.

[0008] <Second aspect> The exterior body is provided separately on the front body and the back body, and the exterior body of the front body and the exterior body of the back body are spaced apart in the front-to-back direction, the exterior body of the back body has a buttocks-covering portion extending below the torso region, the lower edge of the exterior body of the front body is the lower edge of the torso region, and the lower edge of the exterior body of the back body is the lower edge of the buttocks-covering portion, the buttocks-covering portion has a second central region overlapping the interior fastening part, a third side region defined as the region between one of the side seals and the second central region, and a fourth side region defined as the region between the other side seal and the second central region, the buttocks-covering portion has an elastic member and is a stretchable region that stretches and contracts elastically between a natural length state in which it is contracted in the width direction together with the elastic member and an expanded state in which it is stretched in the width direction together with the elastic member to a maximum stretch rate of 150 to 300%, The pants-type absorbent article according to the first aspect, wherein the maximum extensibility of the buttocks-covering portion is smaller than the maximum extensibility of the first central region of the front body.

[0009] (Effects) As mentioned above, the widest part of the inner body in the back body ensures a good fit to the bulge of the buttocks. However, if there is no stretchable region for reducing the width of the inner body from there to the crotch area, the shape stability of the inner body of the back body may be reduced. In contrast, if there is a buttocks-covering portion with a maximum elongation rate approximately halfway between the lower regions of the front and back body, as in this embodiment, the shape stability of the inner body of the back body will be superior compared to when this is not the case.

[0010] <Third Aspect> Low-rigidity regions that do not have the absorbent body are provided across the entire width direction at the front end and rear end of the inner body, the low-rigidity regions being located in the upper region, the upper region having a third central region that overlaps with the low-rigidity region and the inner fastening part, a fifth side region defined as a region between one of the side seals and the third central region, and a sixth side region defined as a region between the other of the side seals and the third central region, the fifth side region and the sixth side region having elastic members and being stretchable regions that elastically stretch between a natural length state in which they are contracted in the width direction together with the elastic members and an expanded state in which they are stretched in the width direction together with the elastic members to a maximum elongation rate of 150 to 300%, the third central region having elastic members and being a stretchable region that elastically stretches between a natural length state in which they are contracted in the width direction together with the elastic members and an expanded state in which they are stretched in the width direction together with the elastic members to a maximum elongation rate of 0.8 to 1 times that of the fifth side region and the sixth side region, The pants-type absorbent article according to the first or second aspect, wherein, in a natural length state, the width of the inner body decreases from the widest part of the inner body toward the rear side of the inner body.

[0011] (Effects) As described above, because the first central region of the lower region of the back body is a non-elastic region, the inner body's widest portion is located in the lower region of the back body when in its natural length. When worn, the inner body's widest portion in the back body extends to cover the left and right bulges of the wearer's buttocks, providing a good fit. In this embodiment, because the third central region adjacent to this first central region is a stretchable region, the width of the inner body decreases from the widest portion toward the rear of the inner body. As a result, when worn, the portion of the back body behind the widest portion of the inner body easily conforms to the three-dimensional surface shape of the wearer's buttocks, further improving the fit of the inner body in the back body. Furthermore, the low-rigidity region located at the front end of the inner body provides a good fit in the front body.

[0012] <Fourth Aspect> The outer body is provided separately on the front body and the back body, and the outer body of the front body and the outer body of the back body are spaced apart in the front-to-back direction, the outer body of the back body has a buttocks-covering portion extending below the torso region so that the dimension in the front-to-back direction increases toward the center in the width direction, the lower edge of the outer body of the front body is the lower edge of the torso region, and the lower edge of the outer body of the back body is the lower edge of the buttocks-covering portion, and rising gathers are provided on both sides in the width direction of the inner body across the entire front-to-back direction of the inner body, the rising gathers have a main body portion extending from a position along the side edge of the absorbent body in the inner body to the front side of the inner body, a front fallen portion formed by fixing a front end of the main body portion in a fallen state to the surface of the inner body, a rear fallen portion formed by fixing a rear end of the main body portion in a fallen state to the surface of the inner body, an unfixed rising portion located between the front fallen portion and the rear fallen portion, and a gathered elastic member provided along the front-to-rear direction at least at the tip of the rising portion, at least the rear fallen portion is located only within the low stiffness region, and in a natural length state, the region of the back body having the inner body is bent so as to form a valley fold when viewed from the outside at the boundary between the low stiffness region and the rear edge of the absorbent body, and is bent so as to form a mountain fold when viewed from the outside at a position spaced forward from the boundary between the low stiffness region and the rear edge of the absorbent body, and the vertical shrinkage ratio of the buttocks cover portion in a natural length state is 0.4 to 0.7 times, A pants-type absorbent article according to a third aspect.

[0013] (Effects) When worn, the buttocks-covering portion contracts upward more than in conventional garments, so it is less likely to get in the way when putting the legs through the leg openings. Furthermore, since the folding of the back body is mostly eliminated while worn, a small amount remains, so the portion between the valley fold and the mountain fold floats off the wearer's skin, creating an advantage of forming a space for storing excrement. Note that the stretch characteristics of the lower region of the front body and the lower region of the back body in the first embodiment are not essential to achieving the effects of the fourth embodiment. Therefore, the same effects can be achieved even when the lower region of the front body and the lower region of the back body in the first embodiment do not have the stretch characteristics of the lower region of the front body.

[0014] <Fifth Aspect> The pants-type absorbent article according to the fourth aspect, wherein the boundary between the rear collapsed portion and the rising portion is located 0 to 15 mm toward the waist opening from the edge of the absorbent body on the waist opening side.

[0015] (Operation and Effect) According to the fifth aspect, the positions of the valley folds as seen from the outer surface are stable, which is preferable.

[0016] According to the present invention, advantages are provided such as the ability to achieve good fit of the inner body in both the front and rear body sections with a simple structure.

[0017] 1 is a plan view (inner side) of a pants-type disposable diaper in an unfolded state. FIG. 2 is a plan view (outer side) of a pants-type disposable diaper in an unfolded state. FIG. 3 is a plan view (inner side) showing a main part of a pants-type disposable diaper in an unfolded state. FIG. 4 is a cross-sectional view taken along line 1-1 of FIG. 1. FIG. 5 is a cross-sectional view taken along line 2-2 of FIG. 1. FIG. 6 is a cross-sectional view taken along line 3-3 of FIG. 1. FIG. 5 is a plan view of a pants-type disposable diaper in an unfolded state showing various regions. FIG. 6 is a plan view of an inner body. FIG. 7 is a plan view (inner side) showing an enlarged main part of a front body part in an unfolded state. FIG. 7 is a cross-sectional view (inner side) showing an enlarged main part of a rear body part in an unfolded state. FIG. 8 is a perspective view showing the front of a pants-type disposable diaper in a worn state. FIG. 9 is a perspective view showing the back of a pants-type disposable diaper in a worn state. FIG. 10 is a front view of a pants-type disposable diaper in a natural length state. FIG. 11 is a back view of a pants-type disposable diaper in a natural length state. FIG. 12 is a longitudinal cross-sectional view schematically showing changes in the state of a pants-type disposable diaper (a) in an unfolded state and (b) in a natural length state.

[0018] An example of a pants-type disposable diaper will be described in detail below with reference to the accompanying drawings. The dotted areas in the cross-sectional view represent adhesive HM, which serves as a joining means for joining the respective components located on the front and back sides of the diaper. This adhesive HM can be applied by solid, bead, curtain, summit, or spiral application of hot melt adhesive, or by pattern coating (transferring the hot melt adhesive using a relief printing method). Alternatively, or in addition, the fixed portions of the elastic members can be applied to the outer periphery of the elastic members using a comb gun or SureWrap application. Hot melt adhesives include, for example, EVA-based, adhesive rubber-based (elastomer-based), polyolefin-based, and polyester / polyamide-based adhesives, but no particular limitation is imposed on the type. Material welding, such as heat sealing or ultrasonic sealing, can also be used as a joining means for joining the respective components.

[0019] 1 to 14 show an example of a pants-type disposable diaper. This pants-type disposable diaper comprises a front outer body 12F having a torso-forming region T of a front body F, a rear outer body 12B having a torso-forming region T of a back body B, and an inner body 200 extending from a middle portion in the width direction WD of the front outer body 12F through the crotch portion to a middle portion in the width direction WD of the rear outer body 12B. Side seals 12A are formed by joining both sides of the front outer body 12F and both sides of the rear outer body 12B, whereby an opening formed by the front and rear ends of the outer bodies 12F, 12B serves as a waist opening WO through which the wearer's torso passes, and portions on both sides of the inner body 200 in the width direction, surrounded by the crotch-side edges 14 of the outer bodies 12F, 12B and the side edges of the inner body 200, serve as leg openings LO through which the legs pass. The inner body 200 absorbs and retains excrement such as urine, and the outer bodies 12F, 12B support the inner body 200 against the wearer's body. The inner body 200 is fixed to the outer bodies 12F, 12B by inner body fastening parts 201. The front body F refers to the entire area of ​​the diaper forward of the center in the front-to-back direction LD, and the back body B refers to the entire area of ​​the diaper rearward of the center in the front-to-back direction LD. Also, the symbol Y in the figure indicates the overall length of the diaper in its unfolded state after the side seals 12A have been peeled off (the length in the front-to-back direction from the edge of the waist opening WO of the front body F to the edge of the waist opening WO of the back body B), and the symbol X indicates the overall width of the diaper in its unfolded state.

[0020] This pants-type disposable diaper has a torso region T, which is defined as the front-to-back range including the side seals 12A (the front-to-back range from the waist opening WO to the top of the leg openings LO), and an intermediate region L, which is defined as the front-to-back range of the portion forming the leg openings LO (between the front-to-back region including the side seals 12A of the front body F and the front-to-back region including the side seals 12A of the back body B). The outer bodies 12F, 12B have a torso region E, which is defined as the region between one side seal 12A and the other side seal 12A. The torso region E can be conceptually divided into a waist portion W, which forms the edge of the waist opening WO, and a lower waist portion U, which is the portion below the waist portion W. Typically, if the torso region E has a boundary where the stretch stress in the width direction WD changes (e.g., where the thickness or maximum elongation rate of the elastic member changes), the waist region W is the portion closer to the waist opening WO than the boundary closest to the waist opening WO. If no such boundary exists, the waist region W is the portion located closer to the waist opening WO than the boundary that passes through the edge of the absorbent body 56 or the inner body 200 on the waist opening WO side and extends linearly in the width direction. The length of these portions in the front-to-back direction LD varies depending on the size of the product and can be determined as appropriate. For example, the waist region W can be 20 to 40 mm, and the lower waist region U can be 150 to 220 mm. Meanwhile, both side edges of the middle region L are constricted to fit around the wearer's legs, forming the areas into which the wearer's legs are inserted. As a result, the pants-type disposable diaper in its unfolded state has a generally hourglass shape overall.

[0021] (Exterior Body) The exterior bodies 12F, 12B in the illustrated example are composed of a rectangular front exterior body 12F having a torso-forming region T of the front body F and a rear exterior body 12B having a torso-forming region T of the back body B. The front exterior body 12F and the rear exterior body 12B are not continuous on the crotch side, but are spaced apart in the front-to-back direction LD (two-piece exterior type). This separation distance 12d in the front-to-back direction LD can be, for example, approximately 30 to 60% of the total length Y. In the illustrated example, the crotch-side edge of the front exterior body 12F is straight along the width direction WD, and the crotch-side edge 14 of the rear exterior body 12B is curved so as to extend toward the crotch side as it approaches the center in the width direction WD, but appropriate modifications are possible, such as the edges 14 of both the front exterior body 12F and the rear exterior body 12B being straight along the width direction WD (the front exterior body 12F and the rear exterior body 12B have the same dimensions in the front-to-back direction LD), or the crotch-side edges 14 of both the front exterior body 12F and the rear exterior body 12B being curved so as to extend toward the crotch side as it approaches the center in the width direction WD. Although not shown, the exterior bodies 12F, 12B may be continuous across the front body F and the back body B, and may have a planar shape (approximately hourglass-shaped overall) that is narrowed in the middle in the front-to-back direction LD to fit around the legs.

[0022] Only both side edges (both ends in the width direction WD) of the exterior bodies 12F, 12B in the range corresponding to the torso region T are joined to form the side seals 12A, thereby forming a ring-shaped waist portion with a waist opening WO. Therefore, in the illustrated example, the rear exterior body 12B is formed with a buttocks-covering portion C extending downward from the torso region E (toward the middle region L), while the front exterior body 12F does not have a portion located in the middle region L. Although not shown, the front exterior body 12F may also be provided with a groin-covering portion extending downward from the torso region E.

[0023] As shown in Figures 1, 2, 4, and 6, the exterior bodies 12F, 12B have an inner sheet layer 12H, an outer sheet layer 12S, and elastic members 15-17 disposed therebetween. Each sheet layer may be formed from a single sheet material, or may be formed from separate sheet materials. In the illustrated example, the exterior bodies 12F, 12B have a pressure sheet 20A and a back sheet 20B. In the lower waist region U, the inner sheet layer 12H is formed from the pressure sheet 20A, and the outer sheet layer 12S is formed from the back sheet 20B. In the waist region W, the inner sheet layer 12H and the outer sheet layer 12S are formed from the inner and outer portions, respectively, of the back sheet 20B folded back at the edge of the waist opening WO. The holding sheet 20A in the illustrated example may be omitted, and the folded portion of the back sheet 20B in the figure may be extended toward the crotch side, with all of the elastic members 15 to 17 sandwiched between the sheets in the folded portion, or all of the elastic members 15 to 17 may be sandwiched between the holding sheet 20A and the back sheet 20B regardless of whether or not a folded portion is provided.

[0024] In the illustrated example, an innermost sheet layer 12C made of nonwoven fabric or the like is attached so as to cover the folded-back portion of the backsheet 20B and the inside of the pressing sheet 20A, and this innermost sheet layer 12C extends to a position where it overlaps with the edge of the inner body 200 on the waist opening WO side. Although not shown, the innermost sheet layer 12C can be omitted. Alternatively, the innermost sheet layer 12C may be omitted and the folded-back portion of the backsheet 20B may be extended to a position where it overlaps with the edge of the inner body 200 on the waist opening WO side to serve as the innermost sheet layer.

[0025] The exterior bodies 12F, 12B incorporate elastic members 15-17, thereby forming stretchable regions (regions having elastic members 15-17) that stretch in the width direction WD in response to the stretching of the elastic members 15-17. These stretchable regions are intended to improve fit to the wearer's body surface, and are preferably provided throughout the entire front-to-back direction LD of the front exterior body 12F and the rear exterior body 12B, although some regions, such as the middle of the front-to-back direction LD, may be omitted. When in their natural length, the stretchable regions contract as the elastic members 15-17 contract, forming wrinkles or creases on the inner and outer surfaces, and when stretched in the width direction WD, they can be stretched up to a predetermined maximum stretch rate without wrinkles. In such an elastic structure, if the inner sheet layer 12H and the outer sheet layer 12S are free from each other, one sheet layer may partially or entirely float relative to the other sheet layer, causing unnecessary folds or bulges, which may lead to poor fit or slippage when worn. Therefore, it is preferable that the inner sheet layer 12H and the outer sheet layer 12S are directly or indirectly bonded over almost their entire length.

[0026] As the elastic members 15 to 17, in addition to elongated elastic members such as rubber threads (illustrated example), known elastic members such as strip-shaped, net-shaped, film-shaped, etc. may be used without any particular limitation. As the elastic members 15 to 17, synthetic rubber such as spandex or natural rubber may be used.

[0027] An adhesive such as a hot melt adhesive is preferably used as a means for fixing the elastic members 15-17 to the inner sheet layer 12H and the outer sheet layer 12S. The inner sheet layer 12H and the outer sheet layer 12S can be bonded together using a hot melt adhesive, or, to reduce the amount of hot melt adhesive used, the inner sheet layer 12H and the outer sheet layer 12S can be bonded together by ultrasonic welding, heat sealing, or the like. For example, when the elastic members 15-17 are elongated elastic members 15-17 such as rubber threads, bonding the inner sheet layer 12H and the outer sheet layer 12S with a hot melt adhesive at the positions where the elastic members 15-17 pass can be achieved, thereby both bonding the inner sheet layer 12H and the outer sheet layer 12S and fixing the elastic members 15-17 to the inner sheet layer 12H and the outer sheet layer 12S. In this case, to reinforce the fixation of the elastic members 15-17, additional hot melt adhesive can be applied only to predetermined regions including both end portions of the elastic members 15-17. Alternatively, only predetermined regions including both end portions of the elastic members 15-17 can be fixed to the inner sheet layer 12H and the outer sheet layer 12S with hot melt adhesive, and the inner sheet layer 12H and the outer sheet layer 12S can be joined by a welding method such as ultrasonic welding at locations other than the positions where the elastic members 15-17 pass. Alternatively, without using hot melt adhesive, the inner sheet layer 12H and the outer sheet layer 12S can be joined by a welding method such as ultrasonic welding at positions adjacent to the elastic members 15-17 in the front-to-back direction, and the elastic members 15-17 can be sandwiched at the joint. Furthermore, the inner sheet layer 12H and the outer sheet layer 12S can be joined by a welding method such as ultrasonic welding so as to extend longitudinally across the elastic members 15-17 in the front-to-back direction. When the elastic members 15-17 are elastic sheets such as elastic films, the inner sheet layer 12H and the outer sheet layer 12S can be joined directly or indirectly via the elastic sheet at multiple joints arranged at intervals. A direct joint is formed in the elastic sheet by providing through-holes that penetrate the elastic sheet in the thickness direction, and the inner sheet layer 12H and the outer sheet layer 12S are joined only within the through-holes. An indirect joint is formed in the elastic sheet by providing no through-holes, and the inner sheet layer 12H and the outer sheet layer 12S are joined via the elastic sheet.

[0028] Nonwoven fabric is suitable for the constituent sheets of the exterior bodies 12F, 12B (in the illustrated example, the aforementioned back sheet 20B, pressing sheet 20A, etc.) from the viewpoint of breathability and texture, but any material can be used as long as it can be welded at the side seal 12A, and for example, other materials, such as thermoplastic resin sheets such as elastic films, can be used instead of or in addition to the nonwoven fabric. When nonwoven fabric is used, it is preferable that the fineness be 1 to 3 dtex and the basis weight be 10 to 25 g / m. ２ Although a spunbond nonwoven fabric of this order is preferred, a short-fiber nonwoven fabric may be used for some or all of the layers. The constituent sheets of the exterior bodies 12F, 12B may be ordinary nonwoven fabrics that have almost no elastic stretch (maximum stretch rate in the width direction WD of less than 110%), or may be sheets that have a certain degree of stretchability (maximum stretch rate in the width direction WD of 200% or more), such as stretchable nonwoven fabrics made of elastomeric fibers or elastic films.

[0029] To explain the elastic members 15-17 in the illustrated example in more detail, a plurality of waist elastic members 15 made of elongated elastic members are attached to the waist region W of the outer bodies 12F, 12B at intervals in the front-to-back direction LD so as to be continuous across the entire width direction WD. One or more of the waist elastic members 15 arranged in the region adjacent to the lower waist region U may overlap the inner body 200, or may be provided on both sides of the region in the width direction WD, excluding the central region in the width direction that overlaps with the inner body 200. The waist elastic members 15 are preferably made of approximately 5 to 10 rubber threads having a thickness of approximately 620 to 1240 dtex, spaced approximately 4 to 8 mm apart, and the maximum elongation of the waist region W in the width direction WD is preferably approximately 260 to 320%.

[0030] Additionally, multiple lower waist elastic members 16 made of elongated elastic members are attached at intervals in the front-to-back direction LD to the lower waist portion U of the exterior bodies 12F, 12B. The lower waist elastic members 16 are preferably 12 to 18 strands of rubber thread having a thickness of approximately 310 to 940 dtex and spaced apart from each other at intervals of approximately 8 to 16 mm, and the maximum stretch rate of the lower waist portion U in the width direction WD is preferably approximately 200 to 280%.

[0031] Furthermore, when a buttocks covering portion C is provided on the rear exterior body 12B as in the illustrated example, a cover elastic member 17 can be provided, which allows the maximum elongation rate of the buttocks covering portion C in the width direction WD to be 200 to 280%, particularly 200 to 240%. Although not shown, a similar cover elastic member can also be provided when a groin covering portion is provided on the front exterior body 12F.

[0032] The waist elastic member 15, lower waist elastic member 16, and cover elastic member 17 are elastically stretchable in the direction along these elastic members. In addition to these elastic members that stretch widthwise, elastic members arranged in a curved line, such as along the leg circumference, may also be provided, but this is not required as shown in the illustrated example. The maximum stretch rate of each portion can be adjusted by the thickness, number, spacing, and elongation rate at the time of attachment of the elastic members 15-17. In particular, the thickness, number, and spacing of the elastic members 15-17 are preferably selected so that the maximum stretch rate of a specific portion of the outer body 12F, 12B is approximately equal to the elongation rate at the time of attachment of the elastic members 15-17 that contract that specific portion when the inner body 200 is not fastened or removed (e.g., 80% or more, more preferably 90% or more of the elongation rate at the time of attachment).

[0033] When the elastic members 16, 17 are provided within the range of the absorbent body 56 in the front-to-back direction LD, as in the lower waist portion U and buttocks-covering portion C in the illustrated example, at least one of the lower waist portion U and buttocks-covering portion C in at least one of the front body F and back body B may have a non-stretchable region in the middle in the width direction WD and stretchable regions on both sides. This improves fit in a specific area. The range of the non-stretchable region in the width direction WD can be determined as appropriate, but the side edges of the non-stretchable region may be located only toward the center in the width direction WD of the side edges of the absorbent body 56, between the side edges of the absorbent body 56 and the side edges of the inner body 200, or between the side edges of the inner body 200 and the side seals 12A. The non-stretchable region preferably includes the entire interior fastening portion 201. When a non-stretchable region is provided in the lower waist portion U, the non-stretchable region may be provided in only a portion of the lower waist portion U in the front-to-back direction LD, or may be provided throughout the entire lower waist portion U. When a non-stretchable region is provided in the buttocks-covering portion C, the non-stretchable region may be provided in only a portion in the front-to-back direction LD of the buttocks-covering portion C, or may be provided over the entire buttocks-covering portion C. Of course, at least one of the lower waist portion U and the buttocks-covering portion C in at least one of the front body F and the back body B may not have a non-stretchable region, and the elastic members 16, 17 may be continuous across the inner body 200.

[0034] The non-stretchable region refers to a region where the elastic members 16, 17 are absent or where the elasticity provided by the elastic members 16, 17 has been eliminated or reduced, and where the maximum elongation is 110% or less. The non-stretchable region can be formed by known methods. It is preferable that the maximum elongation of the non-stretchable region is 100%. Generally, when elongated elastic members 15-17 are used as the elastic members 15-17 in the torso region E, there are roughly two methods for eliminating or reducing the elasticity, either of which can be adopted. That is, the first method involves fixing the elastic members 15-17 to the inner sheet layer 12H and the outer sheet layer 12S continuously or intermittently in the width direction WD, and then heating the non-stretchable region or cutting the elastic members 16, 17 into small pieces in a predetermined cutting pattern using a cutting blade, thereby reducing the maximum elongation in the width direction WD in the non-stretchable region and making the portion other than the non-stretchable region into a stretchable region. In this case, many small pieces of the elastic members 16, 17 remain between the inner sheet layer 12H and the outer sheet layer 12S in a state where they have shrunk to a certain extent. In the second method, the elastic members 16, 17 are left unsecured (or may be weakly secured with a hot melt adhesive) to the inner sheet layer 12H and the outer sheet layer 12S only in the non-stretchable regions, and the unsecured portions are cut at a single location in the middle of the width direction WD and allowed to shrink to or near their natural length without being attached to the inner sheet layer 12H or the outer sheet layer 12S, thereby reducing the maximum elongation in the width direction WD in the non-stretchable regions while making the regions other than the non-stretchable regions stretchable. The second method has the advantage of fewer cut locations compared to the first method.

[0035] When an elastic sheet such as an elastic film is used as the elastic member 17 in the trunk region E, although not shown, a continuous elastic sheet is interposed between the inner sheet layer 12H and the outer sheet layer 12S in the width direction WD, and the inner sheet layer 12H and the outer sheet layer 12S are joined via the elastic sheet at multiple spaced-apart joints, and the number of joints per unit area in the non-stretchable region is increased, thereby reducing the maximum elongation in the width direction WD in the non-stretchable region and making the region other than the non-stretchable region a stretchable region. Furthermore, when the inner sheet layer 12H and the outer sheet layer 12S are directly joined at multiple spaced-apart joints via through-holes that penetrate the elastic sheet in the thickness direction, the joints are arranged so that the non-stretchable region does not have a linearly continuous elastic sheet along the width direction WD, thereby reducing the maximum elongation in the width direction WD in the non-stretchable region and making the region other than the non-stretchable region a stretchable region.

[0036] (Interior fastening portion) The inner body 200 can be fixed to the exterior bodies 12F, 12B by a joining means that uses material welding, such as heat sealing or ultrasonic sealing, or by a hot melt adhesive HM. As shown in Fig. 2, the interior fastening portion 201 that fixes the inner body 200 to the exterior bodies 12F, 12B can be provided over almost the entire area where the inner body 200 and the exterior bodies 12F, 12B overlap, and can be provided over the entire portion of the inner body 200 excluding both end portions in the width direction WD.

[0037] More specifically, the side edges of the interior fastening part 201 may be located only toward the center in the width direction WD from the side edges of the absorbent body 56, or may be located between the side edges of the absorbent body 56 and the side edges of the inner body 200, or may coincide or nearly coincide (for example, within ±5 mm) with the side edges of the inner body 200. It is preferable, but not limited to, that the side edges of the interior fastening part 201 form straight lines along the front-to-back direction LD. The overall width of the interior fastening part 201 on the front body piece F and the overall width of the interior fastening part 201 on the back body piece B may be different, or may coincide or nearly coincide (for example, within ±5 mm).

[0038] The waist opening WO-side edge of the interior fastening part 201 may be located only toward the center in the front-to-rear direction LD relative to the waist opening WO-side edge of the absorbent body 56, or may be located between the waist opening WO-side edge of the absorbent body 56 and the waist opening WO-side edge of the inner body 200, or may be aligned or nearly aligned (e.g., ±5 mm) with the waist opening WO-side edge of the inner body 200. The waist opening WO-side edge of the interior fastening part 201 is preferably, but not limited to, a straight line extending along the width direction WD. In the case of a two-piece outer garment, the crotch-side edge of the interior fastening part 201 may be spaced apart from the crotch-side edge of the outer garments 12F, 12B toward the waist opening WO, or may be aligned or nearly aligned (e.g., ±5 mm) with the crotch-side edge of the outer garments 12F, 12B. The crotch-side edge of the interior fastening part 201 is preferably, but not limited to, a straight line extending along the width direction WD.

[0039] (Preferable stretch characteristics of the outer body) The outer bodies 12F, 12B of the example shown in Figure 1 etc. can be divided into several regions as shown in Figure 7. That is, the lower waist portion U of the outer bodies 12F, 12B of the illustrated example can be divided into an upper region U1 above a boundary line BL that passes through the edge of the waist opening WO side of the absorbent body 56 and extends in the width direction WD, and a lower region U2 below the boundary line BL. In addition, the lower region U2 has a first central region M1 that overlaps with the interior fastening part 201, a first side region S1 defined as the region between one side seal 12A and the first central region M1, and a second side region S2 defined as the region between the other side seal 12A and the first central region M1. and (a) the first side region S1 and the second side region S2 in the front body F and the first side region S1 and the second side region S2 in the back body B are stretchable regions that elastically stretch between a natural length state in which they are contracted in the width direction WD together with the waist lower elastic member 16 and an expanded state in which they are stretched in the width direction WD together with the waist lower elastic member 16 to a maximum stretch rate of 150 to 300% (more preferably 200 to 250%), and (b) the first central region M1 in the back body B is a non-stretchable region with a maximum stretch rate in the width direction WD of 110% or less, and the first central region M1 in the front body F is a stretchable region that elastically stretches between a natural length state in which they are contracted in the width direction WD together with the waist lower elastic member 16 and an expanded state in which they are stretched in the width direction WD together with the waist lower elastic member 16 to a maximum stretch rate of 0.7 to 1 times (more preferably 0.8 to 0.9 times) the first side region S1 and the second side region S2 in the front body F, (c) As shown in Figures 13 and 14, in the natural length state, it is preferable that the inner body 200 has a maximum width portion in the lower region U2 of the back body B, and the width 210 of the inner body 200 in the lower region U2 of the front body F is 0.5 to 0.9 times (more preferably 0.6 to 0.8 times) the maximum width 220 of the inner body 200.

[0040] The maximum elongation rate of a specific portion of outer casing 12F, 12B can be determined as the elongation rate at the elastic limit (at 1 N when the elastic limit cannot be clearly determined) by cutting out a test piece consisting of the specific portion of outer casing 12F, 12B and the gripping portions adjacent to it on both sides in the width direction WD, and then gripping the gripping portions of this test piece with the gripping tools of a tensile testing machine to perform a tensile test.

[0041] The dimensions of specific parts of the exterior bodies 12F, 12B are apparent dimensions, and when measuring the product, they are measured using a ruler after releasing the front body F and back body B at the side seal 12A. When measuring the dimensions in the natural length state, the product is placed on a horizontal surface such as a test bench so that at least the part to be measured (the back body B when measuring the back body B) is exposed on the top surface in as flat a state as possible, and the dimensions are measured by placing a ruler on the part to be measured without applying force to it.

[0042] It should be noted that the width 210 of the inner body 200 refers to the length of a line segment connecting two points, one on one side edge of the inner body 200 and the other on the other side edge of the inner body 200, that are at the same position in the fore-aft direction LD in the unfolded state (i.e., are the same distance from the front or rear end of the inner body 200). The width 210 of the inner body 200 changes depending on the position of the inner body 200 in the fore-aft direction LD (this includes not only cases where the entire fore-aft direction LD changes continuously, but also cases where the inner body has both constant and variable portions). Therefore, the width 210 of the inner body 200 in a specific region that has such a change (for example, the lower region U2) refers to the minimum value within that region.

[0043] As described above, in the lower region U2 of the outer bodies 12F, 12B of the front body F, the entire width direction WD is made a stretchable region, while in the lower region U2 of the outer bodies 12F, 12B of the back body B, the first central region M1 is made a non-stretchable region. As a result, in the natural length state, the maximum width 220 of the inner body 200 is in the lower region U2 of the back body B, and the width 210 of the inner body 200 in the lower region U2 of the front body F is 0.5 to 0.9 times the maximum width 220 of the inner body 200. As shown in Figures 11 and 12, when worn, the maximum width 220 of the inner body 200 in the back body B spreads to cover the left and right bulges of the wearer's buttocks, providing not only a good fit, but also the back body B is less likely to get caught on the bulge of the buttocks when the wearer puts their legs through and pulls up this pants-type absorbent article, making it easier to put on. On the other hand, because the first central region M1 in the front body F is a stretchable region, the width 210 of the inner body 200 in the lower region U2 of the front body F does not widen unnecessarily, and it fits well between the wearer's groin area. Therefore, it is possible to achieve both the fit of the inner body 200 in the front body F and the fit of the inner body 200 in the back body B. Moreover, this fit can be achieved with a simple structure that involves the arrangement of stretchable and non-stretchable regions.

[0044] When the first central region M1 is a non-stretch region and the first side region S1 and second side region S2 on either side of it are stretch regions, as in the lower region U2 of the back body B, the lower region U2 can be formed by connecting assemblies with different maximum stretch rates, but from the standpoint of ease of manufacturing, it is preferable to attach elastic members (in the illustrated example, waist lower elastic member 16) continuously along the width direction WD to the outer bodies 12F, 12B as described above, and to eliminate or reduce the stretchability of the first central region M1 in part or all, making it a non-stretch region with a lower maximum stretch rate, and to make the first side region S1 and second side region S2 stretch regions. When the first central region M1 of the front body F and the first side region S1 and second side region S2 on either side thereof are made into stretchable regions, the lower region U2 can be formed by connecting assemblies with the same or different maximum elongation rates, but from the standpoint of ease of manufacturing, it is preferable to attach the waist lower elastic member 16 continuously along the width direction WD to the outer bodies 12F, 12B to form continuous stretchable regions throughout the entire width direction WD of the first central region M1 and the first side region S1 and second side region S2 on either side thereof.

[0045] In the illustrated example, the number of lower waist elastic members 16 located in the lower region U2 can be determined as appropriate, but it is preferable to provide multiple members in each of the front body F and the back body B. For example, 2 to 10 members, and particularly 3 to 7 members, can be provided in each of the front body F and the back body B. The dimension in the front-to-back direction LD of the lower region U2 of the front body F can be the same as the dimension in the front-to-back direction LD of the lower region U2 of the back body B, or it can be shorter (for example, 0.6 to 0.8 times the dimension in the front-to-back direction LD of the lower region U2 of the back body B). In the former case, the number of lower waist elastic members 16 located in the lower region U2 of the front body F can be the same as the number of lower waist elastic members 16 located in the lower region U2 of the back body B. In the latter case, the number of lower waist elastic members 16 located in the lower region U2 of the front body F can be fewer than the number of lower waist elastic members 16 located in the lower region U2 of the back body B.

[0046] As mentioned above, the maximum width 220 of the inner body 200 in the back body B provides a good fit to the bulge of the buttocks. However, if there is no stretchable region for reducing the width of the inner body 200 from there to the crotch area, there is a risk that the shape stability of the inner body 200 in the back body B will decrease. Therefore, in the case of a two-piece outer body type such as the illustrated example, it is preferable to have a buttocks cover portion C with a maximum stretch rate approximately halfway between the lower region U2 of the front body F and the lower region U2 of the back body B.

[0047] More specifically, the buttocks covering portion C has a second central region M2 overlapping with the interior fastening portion 201, a third side region S3 defined as the region between one side seal 12A and the second central region M2, and a fourth side region S4 defined as the region between the other side seal 12A and the second central region M2. The buttocks covering portion C is an elastic region that elastically stretches and contracts between a natural length state in which it is contracted in the width direction WD together with the cover elastic member 17, and an expanded state in which it is stretched in the width direction WD together with the cover elastic member 17 to a maximum stretch rate of 150 to 300% (more preferably 200 to 250%), and it is preferable that the maximum stretch rate of the buttocks covering portion C is smaller than the maximum stretch rate of the first central region M1 of the front body F (for example, 0.5 to 0.9 times the maximum stretch rate of the first central region M1 of the front body F). As a result, as shown in Figures 12 and 14, the width of the inner body 200 in the back body B is reduced from the maximum width 220 of the inner body 200 to the crotch area, resulting in superior shape stability of the inner body 200 in the back body B compared to when such reduction does not occur.

[0048] When the second central region M2 and the third side region S3 and fourth side region S4 on either side thereof are made into stretchable regions, the buttocks cover portion C can be formed by connecting assemblies with the same or different maximum elongation rates. However, from the viewpoint of ease of manufacturing, it is preferable to attach the cover elastic member 17 continuously along the width direction WD to the outer bodies 12F, 12B to form continuous stretchable regions throughout the entire width direction WD of the second central region M2 and the third side region S3 and fourth side region S4 on either side thereof.

[0049] In the illustrated example, the number of cover elastic members 17 located on the buttocks cover portion C can be determined as appropriate, but it is preferable to provide a plurality of members, for example, 2 to 6, and particularly 3 to 5.

[0050] As will be described later, when the front and rear ends of the inner body 200 have low-rigidity regions 202 that do not have the absorbent body 56 across the entire width direction WD (regions that do not have the absorbent body 56 and therefore have lower rigidity than regions that have the absorbent body 56), the low-rigidity regions 202 can be used to improve the fit of the back body B. That is, as shown in Figures 1, 2, 7, 9, and 10, the low-rigidity region 202 is located in the upper region U1 of the waist lower portion U, and the upper region U1 of the waist lower portion U has a third central region M3 that overlaps with the low-rigidity region 202 and the interior fastening part 201, a fifth side region S5 defined as the region between one side seal 12A and the third central region M3, and a sixth side region S6 defined as the region between the other side seal 12A and the third central region M3. In this case, the fifth side region S5 and the sixth side region S6 are stretchable regions that elastically stretch between a natural length state in which they are contracted in the width direction WD together with the waist lower elastic member 16 and an expanded state in which they are stretched in the width direction WD together with the waist lower elastic member 16 to a maximum stretch rate of 150 to 300%, and the third central region M3 is a stretchable region that elastically stretches between a natural length state in which they are contracted in the width direction WD together with the waist lower elastic member 16 and an expanded state in which they are stretched in the width direction WD together with the waist lower elastic member 16 to a maximum stretch rate of 0.8 to 1 times (more preferably 0.9 to 1 times) the fifth side region S5 and the sixth side region S6, and as can be seen from a comparison of Figures 12 and 14, in the natural length state, it is preferable that the width of the inner body 200 decreases from the portion of the inner body 200 with the maximum width 220 toward the rear of the inner body 200.

[0051] In this way, the third central region M3 adjacent to the first central region M1 is a stretchable region, and the width of the inner body 200 decreases from the portion of maximum width 220 of the inner body 200 toward the rear of the inner body 200, so that when worn, the portion of the rear body B behind the portion of maximum width 220 of the inner body 200 easily conforms to the three-dimensional surface shape of the bulge of the wearer's buttocks, as shown in Figure 12, further improving the fit of the inner body 200 in the rear body B. Also, in the front body F, the fit of the low-rigidity region 202 located at the front end of the inner body 200 is improved.

[0052] When the third central region M3 and the fifth side region S5 and sixth side region S6 on either side thereof are made into stretchable regions, these regions can be formed by connecting assemblies with the same or different maximum elongation rates. However, from the standpoint of ease of manufacturing, it is preferable to attach the waist lower elastic member 16 continuously along the width direction WD to the outer bodies 12F, 12B to form continuous stretchable regions throughout the entire width direction WD of the third central region M3 and the fifth side region S5 and sixth side region S6 on either side thereof.

[0053] In the illustrated example, the number of waist lower elastic members 16 located in the third central region M3 and the fifth side region S5 and sixth side region S6 on either side thereof can be determined as appropriate, but it is preferable to provide multiple members, for example, 2 to 5 members.

[0054] (Inner body) The inner body 200 can have any shape, but in the illustrated example, it is substantially rectangular, with linear front and rear edges along the width direction and linear side edges along the front-to-rear direction. As shown in Figures 4 to 6 and 8, the inner body 200 is equipped with a top sheet 30 that forms an absorbent surface, a liquid-impermeable sheet 11, and an absorbent element 50 interposed between them, and performs an absorbing function. The front and rear ends of the inner body 200 are low-rigidity regions 202 that do not have an absorbent body 56. Reference numeral 60 denotes rising gathers 60 that extend from both sides of the inner body 200 so as to contact the wearer's legs in order to prevent excrement from leaking from the sides of the inner body 200.

[0055] (Top Sheet) The top sheet 30 is a material that is liquid-permeable, and examples thereof include a perforated or non-perforated nonwoven fabric, a perforated plastic sheet, and the like.

[0056] The side edges of the top sheet 30 may be folded back at the side edges of the absorbent element 50 as in the illustrated example, or may be left unfolded and extend beyond the side edges of the absorbent element 50 .

[0057] In order to prevent the top sheet 30 from shifting relative to the backing member, it is desirable to fix the top sheet 30 to the adjacent backing member by a joining means such as heat sealing or ultrasonic sealing, or by a hot melt adhesive HM. In the illustrated example, the top sheet 30 is fixed to the surface of the absorbent element 50 by the hot melt adhesive HM applied to the back surface.

[0058] Although not shown, an intermediate sheet (also called a "second sheet") having a faster liquid permeability rate than the top sheet 30 can be provided between the top sheet 30 and the absorbent element 50 to prevent absorbed liquid from flowing back out of the absorbent body 56.

[0059] (Liquid-impermeable sheet) The material of the liquid-impermeable sheet 11 is not particularly limited, but examples thereof include a plastic film made of a polyolefin resin such as polyethylene or polypropylene, a laminated nonwoven fabric in which a plastic film is provided on the surface of a nonwoven fabric, and a laminated sheet in which a nonwoven fabric or the like is overlaid and bonded to a plastic film. It is preferable to use a liquid-impermeable and moisture-permeable material for the liquid-impermeable sheet 11, which is preferred from the viewpoint of preventing stuffiness. As a moisture-permeable plastic film, a microporous plastic film obtained by kneading an inorganic filler into a polyolefin resin such as polyethylene or polypropylene, forming a sheet, and then stretching it uniaxially or biaxially is widely used. In addition, nonwoven fabrics using microdenier fibers, nonwoven fabrics whose leak-proofing properties have been enhanced by reducing the voids in the fibers through the application of heat or pressure, and sheets that have been made liquid-impermeable without using a plastic film by methods such as coating with a highly absorbent resin or a hydrophobic resin or a water-repellent agent can also be used as the liquid-impermeable sheet 11, but it is preferable to use a resin film in order to obtain sufficient adhesive strength when bonding with the cover nonwoven fabric 13 described below via a hot melt adhesive HM.

[0060] The liquid-impermeable sheet 11 may be of a width that fits on the back side of the absorbent element 50, with the remaining space being made up by other materials, or it may be arranged so that it extends beyond both sides of the width of the absorbent element 50, as in the illustrated example.

[0061] As long as the liquid-impermeable sheet 11 is located behind the absorbent element 50, it may be located behind the sheet that forms the rising gathers, as in the illustrated example, or it may be located on the front side of the sheet that forms the rising gathers.

[0062] (Absorbent Element) The absorbent element 50 has an absorbent body 56 and a packaging sheet 58 that wraps the entire absorbent body 56. The packaging sheet 58 may be omitted. It is desirable to fix almost the entire back surface of the absorbent element 50 to a member adjacent to the back side with a hot melt adhesive or the like, for the purpose of preventing displacement in the inner body 200.

[0063] (Absorbent body) The absorbent body 56 can be any known absorbent body, such as one formed from a fiber aggregate, without any particular limitations. As the fiber aggregate, in addition to stacked short fibers such as cotton-like pulp or synthetic fibers, a filament aggregate obtained by opening a tow (fiber bundle) of synthetic fibers such as cellulose acetate as needed can also be used. When stacking pulp, the fiber weight is, for example, 100 to 300 g / m ２ It can be about.

[0064] The absorbent body 56 may be rectangular in shape, but as shown in Figure 8, etc., if it has an hourglass shape with a narrowed portion 56N in the middle in the front-to-rear direction that is narrower than the front and rear sides, it is preferable because this improves the fit of the absorbent body 56 itself and the rising gathers 60 to the crotch area.

[0065] The dimensions of the absorber 56 can be determined as appropriate, but it preferably extends from the position where it overlaps with the front exterior body 12F, through the crotch area, to the position where it overlaps with the rear exterior body 12B, and as shown in the illustrated example, it can extend to the peripheral edge of the interior body 200 or its vicinity in the front-to-rear direction LD and the width direction WD. Note that the reference symbol 56X indicates the overall width of the absorber 56.

[0066] It is desirable to fix almost the entire back surface of the absorbent body 56 to the adjacent member (packaging sheet 58 in this example) on the back side with a hot melt adhesive or the like in order to prevent the absorbent body 56 from shifting position in the inner body.

[0067] (Superabsorbent Polymer Particles) When the absorbent body 56 is formed from a fiber aggregate, superabsorbent polymer particles can be dispersed and contained in part or all of the fiber aggregate. The term "superabsorbent polymer particles" includes not only "particles" but also "powder." The superabsorbent polymer particles used in this type of disposable diaper can be used as is. For example, when sieving using a 500 μm standard sieve (JIS Z8801-1:2006) (shaking for 5 minutes), the percentage of particles remaining on the sieve is preferably 30% by weight or less. Furthermore, when sieving using a 180 μm standard sieve (JIS Z8801-1:2006) (shaking for 5 minutes), the percentage of particles remaining on the sieve is preferably 60% by weight or more.

[0068] The material for the superabsorbent polymer particles is not particularly limited, but one with a water absorption capacity of 40 g / g or more is preferred. Examples of superabsorbent polymer particles include starch-based, cellulose-based, and synthetic polymer-based materials, and examples that can be used include starch-acrylic acid (salt) graft copolymers, saponified starch-acrylonitrile copolymers, crosslinked products of sodium carboxymethylcellulose, and acrylic acid (salt) polymers. The shape of the superabsorbent polymer particles is preferably a commonly used powder-like shape, but other shapes can also be used.

[0069] The highly absorbent polymer particles preferably have a water absorption rate of 70 seconds or less, particularly 40 seconds or less. If the water absorption rate is too slow, the liquid supplied into the absorbent body 56 tends to flow back out of the absorbent body 56, which is known as backflow.

[0070] Furthermore, the highly absorbent polymer particles preferably have a gel strength of at least 1000 Pa. This effectively prevents the sticky feeling after absorbing liquid, even when the absorbent body 56 is bulky.

[0071] The basis weight of the highly absorbent polymer particles can be determined appropriately depending on the absorption amount required for the application of the absorbent body 56. Therefore, although it cannot be generally stated, it is generally in the range of 100 to 300 g / m ２ It can be said that:

[0072] (Packaging Sheet) When using the packaging sheet 58, tissue paper, particularly crepe paper, nonwoven fabric, polylaminated nonwoven fabric, perforated sheet, etc. can be used as the material. However, it is desirable that the sheet is one from which the superabsorbent polymer particles do not escape. When using nonwoven fabric instead of crepe paper, hydrophilic SMS nonwoven fabric (SMS, SSMMS, etc.) is particularly suitable, and polypropylene, polyethylene / polypropylene composite material, etc. can be used as the material. The basis weight of the packaging sheet 58 is 5 to 40 g / m ２ , especially 10 to 30 g / m ２ It is preferable that the following be used.

[0073] The packaging structure of the packaging sheet 58 can be determined as appropriate, but from the standpoint of ease of manufacturing and preventing leakage of superabsorbent polymer particles from the front and rear edges, it is preferable to wrap the sheet around the absorbent 56 in a cylindrical shape so as to surround the front, back, and both side surfaces, with the front and rear edges extending beyond the front and rear of the absorbent 56, and to join the overlapping wound portions and the overlapping portions of the extending front and rear edges by a joining means such as a hot melt adhesive HM or material welding.

[0074] (Rising gathers) The rising gathers 60 have rising portions 68 that rise from the side portions of the inner body 200, and these rising portions 68 come into contact with the area from the wearer's groin, around the legs, to the buttocks, thereby preventing side leakage. The rising portions 68 of the rising gathers 60 in the illustrated example extend only from the side edges of the inner body 200 toward the center in the width direction WD, but are not limited to this and can be modified as appropriate, for example, to include a base side portion that extends obliquely from the side edges of the inner body 200 toward the center in the width direction WD, and a tip side portion that extends obliquely from the tip of the base side portion toward the outside in the width direction WD.

[0075] Explaining in more detail, the rising gathers 60 in the illustrated example are formed by folding a strip-shaped gathered sheet 62 having a length spanning the entire front-to-rear direction LD of the inner body 200 back in the width direction WD at its tip (end) portion and folding it in half, with a plurality of elongated gathered elastic members 63 fixed at intervals in the width direction WD between the folded-over portion and the sheet in the vicinity thereof in a stretched state along the longitudinal direction. The base end portion of the rising gathers 60 located opposite the tip portion (the end portion opposite the folded-over portion of the sheet in the width direction WD) forms a root portion 65 fixed to the back side of the absorbent body 56 across the entire front-to-rear direction of the inner body 200, and the portion extending from this root portion 65 forms a main portion 66 folded back to the front side of the inner body 200 at a position along the side edge of the absorbent body 56. The front and rear ends of the main body 66 are formed as a front collapsed portion 67A and a rear collapsed portion 67B, which are fixed in a collapsed state to the side surface of the top sheet 30, while the portion located between them is formed as an unfixed raised portion 68, and a gathered elastic member 63 extending along the front-to-rear direction LD is fixed in a stretched state to at least the tip of this raised portion 68.

[0076] In the rising gathers 60 configured as described above, the contractile force of the gather elastic members 63 causes the rising portions 68 to rise up so as to come into contact with the skin as shown by the arrows in Fig. 5. The gathered stretchable region GG to which the gather elastic members 63 are fixed in the rising portions 68 may extend over the entirety of the rising portions 68 in the front-to-rear direction LD, but preferably extends over an area excluding the front and rear ends of the rising portions 68. In this case, the front and rear ends of the rising portions 68 may not have gather elastic members 63, or may have gather elastic members 63 but not be fixed to the rising portions 68, and may contract to their natural length.

[0077] The opposing surfaces of the front fallen portion 67A and the rear fallen portion 67B can be joined using a hot melt adhesive HM as shown in the example shown, or alternatively, material welding such as heat sealing or ultrasonic sealing can be used in addition to or instead of this.

[0078] As the gathered sheet 62, a nonwoven fabric that is soft and has excellent uniformity and hiding power, such as a spunbond nonwoven fabric (SS, SSS, etc.), an SMS nonwoven fabric (SMS, SSMMS, etc.), or a meltblown nonwoven fabric, and that has been subjected to a water-repellent treatment with silicone or the like as necessary, can be suitably used. In this case, the fiber weight of the nonwoven fabric is 10 to 30 g / m ２ It is preferable that the gathered elastic member 63 be approximately equal to the thickness of the gathered elastic member 63. Rubber thread or the like can be used as the gathered elastic member 63. When spandex rubber thread is used, the thickness is preferably 470 to 1240 dtex, more preferably 620 to 940 dtex. The elongation percentage of the gathered elastic member 63 in the attached state is preferably 150 to 350%, more preferably 200 to 300%. The number of gathered elastic members 63 is preferably 2 to 6, more preferably 3 to 5. The appropriate spacing between the gathered elastic members 63 is 3 to 10 mm. This configuration makes it easier for the gathered elastic members 63 to come into contact with the skin over their entire surface within the range in which they are arranged. The gathered elastic members 63 may be arranged not only on the tip side but also on the base side.

[0079] In the rising portion 68 of the rising gathers 60, at least one of various application methods of hot melt adhesive HM and material welding, such as heat sealing or ultrasonic sealing, can be used to bond the inner and outer layers of the gathered sheet 62 together and to secure the gathered elastic member 63 sandwiched therebetween. Bonding the entire inner and outer layers of the gathered sheet 62 together reduces flexibility, so it is preferable to leave the areas other than the adhesive portion of the gathered elastic member 63 unbonded or to only weakly bond them. In the illustrated example, the hot melt adhesive HM is applied only to the outer peripheral surface of the gathered elastic member 63 using an application means such as a comb gun or a SureWrap nozzle, and the gathered elastic member 63 is sandwiched between the inner and outer layers of the gathered sheet 62. In the main body 66, the hot melt adhesive HM applied only to the outer peripheral surface of the gathered elastic member 63 secures the gathered elastic member 63 to the inner and outer layers of the gathered sheet 62 and secures the inner and outer layers of the gathered sheet 62 together.

[0080] (Side Flaps) Side flaps 70 are provided on both sides of the inner body 200, extending laterally from the rising gathers 60. As shown in the illustrated example, each side flap 70 is preferably a flat portion extending only laterally without being folded over. The dimension of each side flap 70 in the width direction WD can be determined as appropriate, but may be, for example, 0.1 to 0.2 times the dimension of the inner body 200 in the width direction WD.

[0081] Each side flap 70 also has a side stretchable region SG that stretches in the front-to-back direction LD, at least in the region between the portion overlapping the front outer body 12F and the portion overlapping the rear outer body 12B. The side stretchable region SG can be configured with one or more elongated side elastic members 73 attached along the front-to-back direction LD at intervals, allowing the side elastic members 73 to contract in the front-to-back direction while also allowing stretch in the front-to-back direction. Furthermore, each side flap 70 preferably has a hollow portion (a portion where adjacent layers in the thickness direction are not joined) extending along its side edge in the front-to-back direction LD. Contraction of the side elastic members 73 causes the portion of the side flap 70 including the hollow portion to contract in the front-to-back direction LD, forming side gathers with numerous pleats aligned in the front-to-back direction LD.

[0082] As shown in the illustrated example, the side flaps 70 preferably have a first sheet layer 71 forming the innermost surface and a second sheet layer 72 forming the outermost surface, with side elastic members 73 provided between them. The sheet materials forming the first sheet layer 71 and the second sheet layer 72 are not particularly limited, and any suitable nonwoven fabric can be selected, such as the nonwoven fabrics usable for the above-described rising gathers 60 and the above-described outer bodies 12F and 12B. In the illustrated example, the side flaps 70 are constructed using a dedicated sheet material separate from the rising gathers 60, but the side flaps 70 can also be constructed by extending the sheet that constitutes the rising gathers 60. The front and rear ends of the side flaps 70 may or may not coincide with the front and rear ends of the rising gathers 60 (i.e., the front and rear ends of the inner body 200 in this case).

[0083] To explain the illustrated example in more detail, the liquid-impermeable sheet 11 arranged on the back side of the root portion 65 of the rising gathers 60 extends laterally beyond both side edges of the rising gathers 60, and a first sheet layer 71 joined to the front side of both side portions of this liquid-impermeable sheet 11 and a second sheet layer 72 joined to the back side extend laterally beyond both side edges of the liquid-impermeable sheet 11. In the illustrated example, the first sheet layer 71 and the second sheet layer 72 are formed from a single sheet folded back at the side edges of the side flaps 70. All of the side elastic members 73 may be located at positions to the side of the liquid-impermeable sheet 11, but as in the illustrated example, if the side elastic members 73 are located at positions overlapping the liquid-impermeable sheet 11 and at positions to the side of the liquid-impermeable sheet 11, even if the contraction force of each side elastic member 73 in the unfolded state is the same, the portion of the side flap 70 to the side of the liquid-impermeable sheet 11 will contract more than the portion having the liquid-impermeable sheet 11, and the side flap 70 will also rise loosely toward the rising gather 60, which is preferable.

[0084] The side elastic members 73 are also not particularly limited, and can be elongated elastic members similar to the above-mentioned gathered elastic members 63. The stretch rate of the side elastic members 73 in the unfolded side flap 70 is preferably 0.6 to 0.9 times the stretch rate of the standing gathers 60. The number of side elastic members 73 is preferably less than that of the gathered elastic members 63 of the standing gathers 60, but may be the same or greater. The arrangement interval of the side elastic members 73 in the width direction is not limited, but can be, for example, about 5 to 10 mm.

[0085] The side elastic members 73 are fixed to the first sheet layer 71 and the second sheet layer 72. To bond the first sheet layer 71 and the second sheet layer 72 together and to fix the side elastic members 73 sandwiched therebetween, various application methods of a hot melt adhesive HM or fixing means using material welding such as heat sealing or ultrasonic sealing can be used.

[0086] The fixed range of the side elastic members 73 in the front-to-back direction LD, i.e., the range of the side stretchable regions SG in the front-to-back direction LD, preferably extends from the portion overlapping with the front exterior body 12F to the portion overlapping with the rear exterior body 12B, as shown in the illustration, but is not limited to this. Therefore, for example, the front end of the side stretchable regions SG may be located at the rear end of the front exterior body 12F or further rearward. Similarly, the rear end of the side stretchable regions SG may be located at the front end of the rear exterior body 12B or further forward. It is also preferable that the range of the side stretchable regions SG in the front-to-back direction LD be the same as the contraction portion of the rising gathers 60 contracted by the gathered elastic members 63, or extend further forward and rearward than that portion.

[0087] The side elastic members 73 may be provided near the side edges of the side flaps 70 as in the illustrated example, but may not be provided in a certain section from the side edges toward the center in the width direction WD.

[0088] (Cover Nonwoven Fabric) In a two-piece outer pants-type disposable diaper, the inner body 200 is exposed between the front outer body 12F and the rear outer body 12B. Therefore, to prevent the liquid-impermeable sheet 11 from being exposed on the back surface of the inner body 200, a cover nonwoven fabric 13 is preferably provided that forms the back surface of the inner body 200 and covers at least the liquid-impermeable sheet 11 from between the front outer body 12F and the inner body 200 to between the rear outer body 12B and the inner body 200. The inner and outer surfaces of the cover nonwoven fabric 13 can be bonded to their respective opposing surfaces via a hot melt adhesive HM. The nonwoven fabric used for the cover nonwoven fabric 13 can be selected, for example, from the same material as the outer bodies 12F, 12B.

[0089] (Position of the fallen portion of the rising gathers, and the positional relationship between the fallen portion and the absorbent body) As shown in Figures 6 and 8 to 10, when the rear fallen portion 67B of the rising gathers 60 is located only within the low stiffness region 202, the contractile force of the gathered elastic member 63 acts to pull the portion forward of the low stiffness region 202 toward the low stiffness region 202, and the stiffness changes suddenly at the front edge of the low stiffness region 202, and as a result, as shown in Figures 13 to 15, in the state of its natural length, the region having the inner body 200 in the rear body B bends so as to form a valley fold as seen from the outside at a boundary 203 between the low stiffness region 202 and the rear edge of the absorbent body 56, and also bends so as to form a mountain fold as seen from the outside at a position 204 spaced forward from the boundary between the low stiffness region 202 and the rear edge of the absorbent body 56. As a result, as shown in the illustrated example, the buttocks-covering portion C extends downward from the torso region E so that its dimension in the front-to-back direction LD increases toward the center in the width direction WD, and when the lower edge of the exterior bodies 12F, 12B of the front body F is the lower edge Ee of the torso region E and the lower edge of the exterior bodies 12F, 12B of the back body B is the lower edge Ce of the buttocks-covering portion C, the overall length of the buttocks-covering portion C in its natural length state is shorter than the overall length of the buttocks-covering portion C in its unfolded state. If the vertical shrinkage ratio of the buttocks-covering portion C in its natural length state is 0.4 to 0.7 (the lower limit is more preferably 0.5, and the upper limit is more preferably 0.6), the buttocks-covering portion C shrinks upward more than conventionally when worn and is closer to the lower edge of the front exterior body 12F, which is linear along the width direction WD, so that the buttocks-covering portion C is less likely to get in the way when putting the legs through the leg openings LO. Furthermore, since the folding of the back body portion B is almost completely eliminated while the garment is being worn, a small amount of bending remains, and the portion between the valley folds and the mountain folds rises from the wearer's skin, creating an advantage of forming a gap for storing excrement. Furthermore, if at least one of the rear collapsed portions 67B is fixed to the low-rigidity region 202 (i.e., closer to the waist opening WO than the edge of the absorbent body 56 on the waist opening WO side), the blocking range provided by the rising gathers 60 is expanded beyond the absorbent body 56 to the waist opening WO side.Here, the vertical shrinkage rate of the buttocks cover portion C in its natural length state means C1 / C2, where C1 and C2 are the lengths of the line segment connecting the intersection of one side edge of the inner body 200 and the front end (lowest end) of the buttocks cover portion C to the rear end (end on the waist opening WO side) of one side edge of the inner body 200 in its natural length state and in its unfolded state, respectively. The length C2 in the unfolded state is preferably about 190 to 210 mm.

[0090] In this case, as shown in Figures 6 and 8 to 10, it is more preferable that the edge 67i of the rear-folded portion 67B located closer to the center in the width direction WD than the side edge 56e of the absorbent body 56. It is also preferable that the boundary 67b of the folded portion 67 with the raised portion 68 be located 0 to 15 mm, particularly 0 to 10 mm, and even more particularly 0 to 5 mm, toward the waist opening WO from the edge of the absorbent body 56 on the waist opening WO side. This distance is indicated by 67d in Figure 8. Positioning the rear-folded portion 67B near the highly rigid absorbent body 56 in this way is preferable because it stabilizes the position of the valley fold as seen from the outer surface.

[0091] The vertical shrinkage rate of the buttocks-covering portion C in its natural length can be adjusted by changing the degree of bending of the back body portion B mainly by adjusting the elongation rate of the gather elastic member 63. Furthermore, it is preferable that the distance 12Bu in the front-to-back direction LD between the rear fallen-down portion 67B of the rising gathers 60 and the frontmost end of the rear exterior body 12B (the lowest end of the buttocks-covering portion C) is longer than the distance 12F in the front-to-back direction LD between the front fallen-down portion 67A of the rising gathers 60 and the lowest end of the front exterior body 12F, for example, by 2 to 4 times (more preferably 2.5 to 3.5 times) this, because this makes it easier for the back body portion B to bend and also reduces the vertical shrinkage rate of the buttocks-covering portion C in its natural length.

[0092] As shown in the illustrated example, it is preferable that both the front collapsed portion 67A and the rear collapsed portion 67B are located only within the low stiffness region 202, but it is also possible that only the rear collapsed portion 67B is located only within the low stiffness region 202, and the front collapsed portion 67A extends not only within the low stiffness region 202 but also to the region overlapping with the absorbent body 56.

[0093] In particular, the low-rigidity regions 202 (front and rear ends) of the inner body 200 are prone to gaps between themselves and the skin due to the difference in level with the absorbent body 56. Therefore, as in this example, if the lower-waist elastic members 16 of the outer bodies 12F, 12B are provided so as to be continuous in the width direction WD across the region overlapping with the low-rigidity regions 202 of the inner body 200, this region where gaps are likely to occur is pressed toward the skin throughout the entire width direction WD, which is preferable from the standpoint of leak prevention. However, if the inner fastening part 201 is provided to include regions extending to both sides of the low-rigidity region 202 in the width direction WD, and the collapsed portions 67A, 67B are located in the low-rigidity region 202, the collapsed portions 67 will contract in the width direction WD due to the contractile force of the lower-waist elastic members 16, not only in the natural length state but also when worn with a certain degree of stretching. This narrowing of the width of the collapsed portions 67A, 67B may reduce the width of the raised portions 68, i.e., the raised height. However, as mentioned above, when the fallen portions 67A, 67B are positioned close to the absorbent body 56, the fallen portions 67 are less likely to deform the end of the inner body 200 on the waist opening WO side in the width direction WD, so gaps are less likely to occur in the low rigidity region 202 of the inner body 200, and there is also less reduction in the rising height due to a reduction in the width of the fallen portions 67A, 67B.

[0094] The fixing region 67f for fixing the fallen portions 67A, 67B can be any suitable shape, such as square or rectangular. The width of the fixing region 67f (the width of the hot melt adhesive HM applied in the illustrated example) is preferably narrow if flexibility is a priority, but is preferably wide to stabilize the position and shape of the fallen portions 67A, 67B. For example, it is preferable for the width 67f to be at least 50%, particularly at least 90%, of the width 67w of the fallen portions 67A, 67B. The width 67w of the fallen portions 67A, 67B is preferably 15 to 25 mm. Furthermore, to improve the ability to block excretory fluids migrating along the raised portion 68 toward the waist opening WO, it is preferable for the fixing region 67f of the fallen portions 67A, 67B to continue to the base portion 65.

[0095] The rigidity of the absorbent body 56 is not particularly limited, but if the torsional stiffness of a predetermined portion of the absorbent body 56, including the end portion on the waist opening WO side, is 0.10 to 0.32 N·cm / cm, it is preferable in order to stabilize the position and shape of the collapsed portions 67A, 67B using the rigidity of the absorbent body 56.

[0096] Furthermore, in the present example, when the rising gathers 60 have a root portion 65 fixed to the inner body 200 on the back side of the absorbent body 56, and the main body portion 66 is a portion folded from the root portion 65 to the front side of the inner body 200 at a position along the side edge of the absorbent body 56, it is preferable that the side portion of the rising gathers 60 from the folded position to the back side of the absorbent body 56 is not joined to the adjacent member on the back side. In this unjoined region 67x, the contractile force of the waist lower elastic member 16 is not transmitted to the fallen portions 67A, 67B, so that a decrease in the rising height due to a decrease in the width of the fallen portions 67A, 67B is more reliably suppressed. The width of this unjoined region 67x is not particularly limited, but it is preferably at least 50%, and particularly at least 90%, of the width of the fixed region 67f of the fallen portions 67A, 67B.

[0097] Furthermore, as in this example, when the outer bodies 12F, 12B have an innermost sheet layer 12C that extends across both sides of the inner body 200 in the width direction WD and covers the inner body 200 from the waist opening WO side to the portion adjacent to the crotch side of the low-rigidity region 202, the edge of the inner body 200 on the waist opening WO side can be covered, preventing the edge from deteriorating the feel against the skin. Furthermore, the non-bonded region of the innermost sheet layer 12C also functions as a leakage prevention wall in the front-to-back direction LD. However, if the innermost sheet layer 12C is fixed to the rising portion 68, even if the rising portion 68 is expanded toward the waist opening WO using the above-mentioned structure, the movement of the rising portion 68 is hindered by the innermost sheet layer 12C, reducing the fit of the rising gathers 60. Therefore, in this case, it is preferable that the innermost sheet layer 12C has a joined area CA on the waist opening WO side that is joined to an adjacent member on the back side, and a non-jointed area NC on the crotch side that is not joined to an adjacent member on the back side, based on an imaginary line VL in the width direction WD that passes through the fallen portions 67A, 67B, because this allows the rise-up portion 68 to expand toward the waist opening WO while preventing a decrease in the fit of the rise-up portion 68.

[0098] (Nonwoven Fabric) As the nonwoven fabric in the above description, known nonwoven fabrics can be used as appropriate depending on the location and purpose. The constituent fibers of the nonwoven fabric can be selected without particular limitation, for example, synthetic fibers such as polyolefins (e.g., polyethylene or polypropylene), polyesters, and polyamides (including single-component fibers as well as core-sheath and other composite fibers), regenerated fibers (e.g., rayon or cupra), and natural fibers (e.g., cotton), and mixtures of these can also be used. In order to increase the flexibility of the nonwoven fabric, it is preferable that the constituent fibers be crimped fibers. Furthermore, the constituent fibers of the nonwoven fabric may be hydrophilic fibers (including fibers made hydrophilic by a hydrophilizing agent), hydrophobic fibers, or water-repellent fibers (including fibers made water-repellent by a water-repellent agent). Furthermore, nonwoven fabrics are generally classified into staple fiber nonwoven fabrics, long fiber nonwoven fabrics, spunbond nonwoven fabrics, meltblown nonwoven fabrics, spunlace nonwoven fabrics, thermal bond (air-through) nonwoven fabrics, needle-punched nonwoven fabrics, point-bond nonwoven fabrics, laminated nonwoven fabrics (including SMS nonwoven fabrics and SMMS nonwoven fabrics in which a meltblown layer is sandwiched between spunbond layers), and the like, depending on the fiber length, sheet formation method, fiber bonding method, and laminated structure, and any of these nonwoven fabrics can be used.

[0099] <Explanation of Terms Used in the Specification> The following terms used in the specification have the following meanings unless otherwise specified in the specification.

[0100] The "front-to-back direction" refers to the direction indicated by the symbol LD in the figure (vertical direction), and the "width direction" refers to the direction indicated by the symbol WD in the figure (left-to-right direction), and the front-to-back direction and the width direction are perpendicular to each other.

[0101] "Front side" means the side closest to the wearer's skin when the pants-type disposable diaper is worn, and "rear side" means the side farthest from the wearer's skin when the pants-type disposable diaper is worn.

[0102] "Front surface" means the surface of the component that is closest to the wearer's skin when the pants-type disposable diaper is worn, and "back surface" means the surface that is farthest from the wearer's skin when the pants-type disposable diaper is worn.

[0103] "Elongation rate" refers to a value when the natural length is 100%. For example, an elongation rate of 200% is equivalent to an elongation ratio of 2 times.

[0104] "Maximum elongation rate" means the elongation rate when stretched to the elastic limit (in other words, the elongation rate when the stretchable area is contracted (including any contraction, such as contraction due to elastic members) or when it is deployed flat without slack).

[0105] "Gel strength" is measured as follows: 1.0 g of superabsorbent polymer is added to 49.0 g of artificial urine (a mixture of 2 wt% urea, 0.8 wt% sodium chloride, 0.03 wt% calcium chloride dihydrate, 0.08 wt% magnesium sulfate heptahydrate, and 97.09 wt% ion-exchanged water), and the mixture is stirred with a stirrer. The resulting gel is left in a thermo-hygrostat at 40°C and 60% RH for 3 hours, then returned to room temperature, and the gel strength is measured using a curd meter (Curdmeter-MAX ME-500, manufactured by I.techno Engineering).

[0106] - "Basis weight" is measured as follows. After pre-drying the sample or test piece, it is left in a test room or device under standard conditions (test location: temperature 23±1°C, relative humidity 50±2%) until it reaches a constant weight. Pre-drying refers to bringing the sample or test piece to a constant weight in an environment at a temperature of 100°C. Note that pre-drying is not necessary for fibers with an official moisture regain of 0.0%. Using a sample collection template (100mm x 100mm), a sample measuring 100mm x 100mm is cut from the test piece when it has reached a constant weight. The weight of the sample is measured and multiplied by 100 to calculate the weight per square meter, which is the basis weight.

[0107] The "thickness" of thick members such as the absorber 56 and the absorbent element 50 is measured using a thickness measuring device (Peacock, Dial Thickness Gauge, Model H (measurement range 0 to 10 mm, measurement area circular terminal with diameter 10 mm, measurement force approximately 1.7 N, pressure approximately 21.7 KPa)) manufactured by Ozaki Manufacturing Co., Ltd., with the sample and the thickness measuring device positioned horizontally.

[0108] The "thickness" of thin sheets such as nonwoven fabrics was measured using an automatic thickness measuring device (KES-G5 handy compression measurement program) with a load of 0.098 N / cm ２ , and pressure area: 2 cm ２ The torsional stiffness is measured automatically under the following conditions. "Torsion stiffness" refers to the measured value obtained by the following test. In order to apply as little force as possible to the absorbent body, a section of the absorbent body measuring 60 mm in the front-to-back direction from the edge of the waist opening side to the crotch side was cut out with a width of 140 mm so that the absorbent body was positioned in the center in the width direction, and the entire section was wrapped in a single layer of crepe paper (basis weight 15 g / m ２ ) to prepare a test specimen. Using a torsion tester (Kato Tech Co., Ltd., KES-YN-1-B), both ends (10 mm) of the test specimen in the width direction are gripped with chucks with a chuck distance of 110 mm, and the maximum load (torsion hardness) is measured when the specimen is twisted 70° around the longitudinal center axis. The test conditions are SENS (recording sensitivity): 10, torsion angle: 7, CONTROL: 7, and speed 12 cm / s. The test is conducted on five test specimens, and the average value is taken as the measured value of torsion hardness.

[0109] The water absorption amount is measured according to JIS K7223-1996 "Test method for water absorption amount of superabsorbent resins."

[0110] The water absorption rate is the "time to the end point" when 2 g of superabsorbent polymer and 50 g of physiological saline are used and tested according to JIS K7224-1996 "Test method for water absorption rate of superabsorbent polymers."

[0111] "Expanded state" means a state in which the device is stretched to its elastic limit (in other words, a contracted state (including any contraction such as contraction due to an elastic member) or a state in which the device is deployed flat without slack).

[0112] - Unless otherwise specified, the dimensions of each part refer to the dimensions in the unfolded state, not the natural length state.

[0113] - If there is no description of the environmental conditions for a test or measurement, the test or measurement shall be carried out in a test room or device under standard conditions (the test location shall be a temperature of 23±1°C and a relative humidity of 50±2%).

[0114] The present invention can be used in pants-type disposable diapers such as those in the above examples.

[0115] 11...liquid-impermeable sheet, 12A...side seal, 12B...rear exterior body, 12C...innermost sheet layer, 12F, 12B...exterior body, 12F...front exterior body, 12H...inner sheet layer, 12S...outer sheet layer, 13...cover nonwoven fabric, 15-17...elastic member, 15...waist elastic member, 16...lower waist elastic member, 17...cover elastic member, 30...top sheet, 50...absorbent element, 56...absorbent body, 58...packaging sheet, 60...rising gathers, 62...gathered sheet, 63...gathered elastic member, 65...base portion, 66...main body portion, 67A, 67B...folded portion, 67A...front folded portion, 67B...rear folded portion, 68...rising portion, 70...side flap, 71...first sheet layer, 7 2...second sheet layer, 73...side elastic member, 200...inner body, 201...inner body fixing portion, 202...low rigidity region, 210...width, 220...maximum width, B...back body, BL...boundary line, C...buttocks covering portion, E...torso region, F...front body, HM...hot melt adhesive, L...middle region, LD...front-to-back direction, LO...leg opening, SG...side stretchable region, T...torso forming region, U...lower waist portion, U1...upper region, U2...lower region, W...waist portion, WD...width direction, WO...waist opening, M1...first central region, M2...second central region, M3...third central region, S1...first side region, S2...second side region, S3...third side region, S4...fourth side region, S5...fifth side region, S6...sixth side region.

Claims

1. A garment comprising: an integrated outer body extending from the front to the back body, or outer bodies provided separately for the front and back body; an inner body extending from the middle of the front body in the width direction, passing through the crotch area, to the middle of the back body in the width direction; an absorbent body built into the inner body so as to extend from the middle of the front body in the width direction, passing through the crotch area, to the middle of the back body in the width direction; an inner body fixing section that fixes the inner body to the outer body; side seals that join both sides of the outer body on the front body to both sides of the outer body on the back body, respectively; a waist opening and a pair of left and right leg openings; the outer body on the front body and the outer body on the back body each have a torso region defined as the region between one of the side seals and the other of the side seals, and the torso region comprises a waist section that extends from one of the side seals along the edge of the waist opening to the other of the side seals, and a lower waist section that is adjacent to the lower part of the waist section and extends from one of the side seals to the other of the side seals, the waist lower portion comprises an upper region above a boundary line that passes through the edge of the waist opening side of the absorbent body and extends in the width direction, and a lower region below the boundary line, the lower region having a first central region that overlaps with the interior fastening part, a first side region that is defined as the region between one of the side seals and the first central region, and a second side region that is defined as the region between the other of the side seals and the first central region, the first side region and the second side region in the front body and the first side region and the second side region in the back body having elastic members and being stretchable regions that stretch and contract between a natural length state in which they are contracted in the width direction together with the elastic members and an expanded state in which they are stretched in the width direction together with the elastic members to a maximum stretch rate of 150 to 300%, The first central region in the back body is a non-elastic region having a maximum widthwise extension rate of 110% or less, and the first central region in the front body has an elastic member and is an elastic region that elastically extends and contracts between a natural length state in which it contracts in the widthwise direction together with the elastic member and an expanded state in which it stretches in the widthwise direction together with the elastic member to a maximum extension rate of 0.7 to 1 times that of the first side region and the second side region in the front body,A pants-type absorbent article characterized in that, in a natural length state, the inner body has a maximum width in the lower region of the back body, and the width of the inner body in the lower region of the front body is 0.5 to 0.9 times the maximum width of the inner body.

2. The exterior bodies are provided separately on the front body and the back body, and the exterior body of the front body and the exterior body of the back body are spaced apart in the front-to-back direction, the exterior body of the back body has a buttocks-covering portion extending below the torso region, the lower edge of the exterior body of the front body is the lower edge of the torso region, and the lower edge of the exterior body of the back body is the lower edge of the buttocks-covering portion, the buttocks-covering portion has a second central region overlapping the interior fastening portion, a third side region defined as the region between one of the side seals and the second central region, and a fourth side region defined as the region between the other of the side seals and the second central region, the buttocks-covering portion has an elastic member and is a stretchable region that stretches and contracts elastically between a natural length state in which it is contracted in the width direction together with the elastic member and an expanded state in which it is stretched in the width direction together with the elastic member to a maximum stretch rate of 150 to 300%, The pants-type absorbent article according to claim 1, wherein the maximum extensibility of the buttocks-covering portion is smaller than the maximum extensibility of the first central region of the front body.

3. Low-rigidity regions not having the absorbent body are provided across the entire width at the front and rear ends of the inner body, the low-rigidity regions being located in the upper region, the upper region having a third central region overlapping the low-rigidity region and the inner fixing part, a fifth side region defined as the region between one of the side seals and the third central region, and a sixth side region defined as the region between the other of the side seals and the third central region, the fifth side region and the sixth side region having an elastic member and being stretchable regions that elastically stretch between a natural length state in which they are contracted in the width direction together with the elastic member and an expanded state in which they are stretched in the width direction together with the elastic member to a maximum stretch rate of 150 to 300%, the third central region having an elastic member and being a stretchable region that elastically stretches between a natural length state in which they are contracted in the width direction together with the elastic member and an expanded state in which they are stretched in the width direction together with the elastic member to a maximum stretch rate of 0.8 to 1 times that of the fifth side region and the sixth side region, The pants-type absorbent article according to claim 1 or 2, wherein, in a natural length state, the width of the inner body decreases from the widest part of the inner body toward the rear side of the inner body.

4. The outer body is provided separately on the front body and the back body, and the outer body of the front body and the outer body of the back body are spaced apart in the front-to-back direction, the outer body of the back body has a buttocks covering portion extending below the torso region so that the dimension in the front-to-back direction increases toward the center in the width direction, the lower edge of the outer body of the front body is the lower edge of the torso region, and the lower edge of the outer body of the back body is the lower edge of the buttocks covering portion, and the inner body has rising gathers on both sides in the width direction that extend over the entire front-to-back direction of the inner body, 4. The pants-type absorbent article of claim 3, wherein the rising gathers have a main body portion extending from a position along the side edge of the absorbent body in the inner body to the front side of the inner body, a front fallen portion formed by fixing a front end of the main body portion in a fallen state to the surface of the inner body, a rear fallen portion formed by fixing a rear end of the main body portion in a fallen state to the surface of the inner body, an unfixed rising portion located between the front fallen portion and the rear fallen portion, and a gathered elastic member provided along the front-to-rear direction at least at a tip of the rising portion, wherein at least the rear fallen portion is located only within the low rigidity region, and wherein, in a natural length state, a region of the back body having the inner body is bent so as to form a valley fold at the boundary between the low rigidity region and the rear edge of the absorbent body as viewed from the outside, and is bent so as to form a mountain fold at a position spaced forward from the boundary between the low rigidity region and the rear edge of the absorbent body as viewed from the outside, and wherein the vertical shrinkage ratio of the buttocks cover portion in a natural length state is 0.4 to 0.7 times.

5. A pants-type absorbent article according to claim 4, wherein the boundary between the rear collapsed portion and the rising portion is located 0 to 15 mm toward the waist opening from the edge of the absorbent body on the waist opening side.

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