Absorbent panty-type items

Abstract

Regarding absorbent panty-type garments that are gentle on the skin. [Solution] The pant-type absorbent article comprises an absorbent body and an outer casing. The outer casing has a ventral portion, a dorsal portion, and a side seal. The dorsal portion has a dorsal extension and a dorsal main body, and the dorsal extension has a side reinforcement portion. The dorsal main body has a dorsal upper portion located around the wearer's waist, and the ventral portion has a ventral upper portion located in the same longitudinal position as the dorsal upper portion. The dorsal extension, dorsal upper portion, and ventral upper portion are elastic. In the natural length state, the first intersection angle between a first imaginary line passing through the upper end and lower end of the side seal and a second imaginary line passing through the upper end and lower end of the side reinforcement portion is 5 degrees or more and 30 degrees or less, and the third point is located laterally inward from the first imaginary line. In the worn state, the second intersection angle between a third imaginary line parallel to the longitudinal direction passing through the lower end of the side reinforcement portion and the second imaginary line is 10 degrees or more and 70 degrees or less, and the third point is located dorsally from the third imaginary line. The first intersection angle is smaller than the second intersection angle.

Description

Technical Field

[0001] The present invention relates to pants-type absorbent articles such as disposable diapers.

Background Art

[0002] A pants-type absorbent article generally includes an absorbent main body, an exterior body, and side seals where the ventral exterior body and the dorsal exterior body are joined at their side end portions. The ventral exterior body and the dorsal exterior body are joined by the side seals, thereby forming the waist portion of the pants-type absorbent article.

[0003] Patent Documents 1 and 2 disclose pants-type absorbent articles having a dorsal extension portion on the waist side of the dorsal side of the exterior body. With such a configuration, for example, excrement can be prevented from leaking from the dorsal side. Furthermore, the pants-type absorbent article described in Patent Document 1 has side reinforcing portions provided at a pair of laterally opposed dorsal extension side edge portions of the dorsal extension portion.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Patent Document 2

Summary of Invention

Problems to be Solved by the Invention

[0005] For example, when putting absorbent pants on infants or toddlers, it is common for caregivers to insert their hands inside the absorbent pants and spread them out to create space for the wearer's legs and torso. During this action, absorbent pants with a back extension and side reinforcements present the problem of the rigid side reinforcements pressing against the caregiver's fingers. Additionally, when a wearer puts on absorbent pants with a back extension and side reinforcements, the rigid side reinforcements can press against the wearer's sides (around the flanks), and when force is applied to the sides of the waist during sleep, the side reinforcements can easily dig into the wearer's skin.

[0006] This invention has been made in view of the above problems, and relates to a pant-type absorbent article that is comfortable against the skin. [Means for solving the problem]

[0007] A pant-type absorbent article according to one embodiment of the present invention comprises an absorbent body and an outer casing, and has a longitudinal direction extending from the wearer's abdominal side through the crotch area to the back, and a transverse direction perpendicular to the longitudinal direction. The outer casing described above is positioned on the non-skin-facing side of the absorbent body and has a waist opening and a pair of leg openings. The above-mentioned exterior body is A ventral portion positioned on the wearer's abdominal side and having an ventral waist end that constitutes the waist opening, A back portion positioned on the back of the wearer, having a back waist end that constitutes the waist opening, A pair of side seals, each joined to the lateral edge of the ventral portion in the lateral direction and the lateral edge of the dorsal portion in the lateral direction, It holds. The dorsal waist end is located further from the pair of leg openings in the longitudinal direction than the ventral waist end. The rear side portion of the above exterior body is In the longitudinal direction described above, a dorsal extension extends from the ventral waist end to the dorsal waist end, The dorsal main body portion obtained by removing the dorsal extension portion from the dorsal portion, It holds. The above dorsal extension is, A pair of dorsal extension side edges, each facing each other in the lateral direction and extending in the longitudinal direction, A pair of side reinforcing portions are provided on each of the pair of dorsal extension side edges mentioned above. It holds. The above-mentioned side seal has an upper end and a lower end that are opposite to each other in the vertical direction and extend in the horizontal direction. The above-mentioned side reinforcement portion has an upper end portion and a lower end portion that are opposite to each other in the vertical direction and extend in the horizontal direction. The main body on the back has an upper back portion located around the wearer's waist. The ventral portion has a ventral upper portion that is in the same position as the dorsal upper portion in the longitudinal direction. The dorsal extension, the dorsal upper part, and the ventral upper part each have one or more elastic bodies that extend in the lateral direction and are expandable and contractible in the lateral direction. In the natural length state, the first intersection angle, which is the intersection angle between the first imaginary line, which is a straight line passing through the first point on the outermost side of the upper end of the side seal and the second point on the outermost side of the lower end of the side seal, and the second imaginary line, which is a straight line passing through the third point on the outermost side of the upper end of the side reinforcement and the fourth point on the outermost side of the lower end of the side reinforcement, is between 5 degrees and 30 degrees, and the third point is located laterally inward from the first imaginary line. When worn, the second intersection angle, which is the intersection angle between the third imaginary line parallel to the vertical direction passing through the fourth point and the second imaginary line, is between 10 degrees and 70 degrees, and the third point is located on the dorsal side of the third imaginary line. The first intersection angle mentioned above is smaller than the second intersection angle mentioned above. [Effects of the Invention]

[0008] The absorbent pant-type article of the present invention is gentle on the skin. [Brief explanation of the drawing]

[0009] [Figure 1] It is a schematic perspective view showing the pants-type absorbent articles according to the first to third embodiments of the present invention. [Figure 2] It is a schematic side view showing a wearing state in which a wearer is wearing the pants-type absorbent article according to the first embodiment. [Figure 3] It is a schematic plan view showing the skin side surface of the pants-type absorbent article of the first embodiment, and is a diagram showing a mode in which the pants-type absorbent article is unfolded and the elastic members of each part are stretched to spread out into a planar shape. [Figure 4] It is a plan view of the pants-type absorbent articles of the first to third embodiments in a natural length state placed flat. [Figure 5] It is a diagram showing a pseudo wearing state of the pants-type absorbent article of the first embodiment. [Figure 6] It is an enlarged view of the region enclosed by the circle VI in FIG. 5, and is a diagram near the side reinforcing portion of the pants-type absorbent article in the worn state. [Figure 7] (A) is a schematic partial enlarged view showing a state where a caregiver passes a hand from the leg opening portion to the waist opening portion of the pants-type absorbent articles of the first to third embodiments to spread the pants-type absorbent article, and (B) is a schematic partial enlarged view showing a state where a caregiver spreads the waist opening of the pants-type absorbent articles of the first to third embodiments with fingers. [Figure 8] (A) is a schematic side view showing the arrangement positions of the elastic bodies of the pants-type absorbent article of the first embodiment, and (B) is a schematic partial plan view for explaining the arrangement positional relationship of the elastic bodies of the ventral side portion and the back side main body portion joined by the side seals of the pants-type absorbent article of the first embodiment, and the elastic body of the back side extending portion, and is a diagram showing a mode in which the elastic bodies of each part are stretched and spread out into a planar shape. [Figure 9] It is a schematic cross-sectional view of the side seal and the side reinforcing portion of the pants-type absorbent article of the first embodiment. [Figure 10] It is a schematic plan view showing the side seal and the side reinforcing portion of the pants-type absorbent articles of the first to fourth embodiments. [Figure 11]This is a schematic plan view of an exterior body that constitutes a part of the pants-type absorbent articles of the first to third embodiments. [Figure 12] This is a schematic cross-sectional view of the side seal and the side reinforcing portion of the pants-type absorbent article of the second embodiment. [Figure 13] This is a schematic cross-sectional view of the side seal and the side reinforcing portion of the pants-type absorbent article of the third embodiment. [Figure 14] This is a diagram showing a simulated worn state of the pants-type absorbent articles of the second embodiment and the third embodiment. [Figure 15] This is a schematic perspective view showing the pants-type absorbent article according to the fourth embodiment. [Modes for Carrying Out the Invention]

[0010] Hereinafter, embodiments of the present invention will be described with reference to the drawings. Note that the same reference numerals are assigned to the previously described configurations, and descriptions thereof may be omitted.

[0011] <First Embodiment> <<Overall Configuration of Pants-type Absorbent Article>> In Figure 1, Figure 2 and Figure 3, a pants-type disposable diaper 1 is shown as the pants-type absorbent article according to the embodiment of the present invention. The pants-type disposable diaper 1 is hereinafter referred to as the diaper 1. Figure 2 schematically shows the diaper 1 when worn, and the wearer's torso 13 and legs 14 are also illustrated.

[0012] As shown in Figure 1, the diaper 1 is provided with a waist opening 1W and a pair of leg openings 1L, and is worn around the wearer's waist and crotch portion when in use. The waist opening 1W has a waist opening end Wa. The diaper 1 has a longitudinal direction X and a lateral direction Y. The longitudinal direction X corresponds to the direction extending from the wearer's ventral side through the crotch portion to the dorsal side. The lateral direction Y is orthogonal to the longitudinal direction X.

[0013] In the unfolded and extended state of diaper 1 shown in Figure 3 and the natural length state of diaper 1 when laid flat shown in Figure 4, the horizontal direction Y corresponds to the left-right direction of the wearer. Furthermore, as shown in Figure 3, the direction perpendicular to the vertical direction X and horizontal direction Y of diaper 1 in the unfolded and extended state is defined as the thickness direction Z.

[0014] In this specification, "natural length state" means the state in which no external force is applied to the diaper 1 to stretch it, and is the state of the diaper 1 when laid flat. When laid flat, it means the state in which the diaper 1 before use is placed on a flat surface such as a floor, table, shelf, or desk.

[0015] As shown in Figures 2 and 5, in the waist area of ​​the diaper 1 when worn, the lateral direction Y coincides with the circumferential direction of the waist area. As shown in Figures 2 and 5, in the waist area of ​​the diaper 1 when worn, the vertical direction X includes the up-down direction and the front-back direction, and the lateral direction Y, the up-down direction, and the front-back direction are orthogonal to each other. In the front-back axis, the front direction means the ventral side, and the back direction means the dorsal side. In the up-down axis, the upward direction means the waist opening 1W side, and the downward direction means the crotch area 9 side. The above-mentioned "waist area" is a tubular part in which the dorsal main body part 61 (described later) and the ventral part 3 (described later) are joined by a side seal 8 (described later).

[0016] In this specification, "wearing state" means the state in which the diaper 1 is stretched to 75% of its maximum stretched dimensions. "Maximum stretched dimensions" refers to the inner circumference dimension along the lateral direction Y of the waist portion of the diaper 1 when the elastic body positioned around the waist portion of the diaper 1 is stretched to its maximum extent. Specifically, as shown in Figure 5, a planar rectangular acrylic plate 28 (for example, 10 mm thick (height)) having an outer circumference of 75% of the above-mentioned maximum stretched dimensions of the diaper 1 is prepared, and the acrylic plate 28 is inserted into the diaper 1 through the waist opening 1W of the diaper 1, and the waist portion is stretched by the acrylic plate 28 to simulate the "wearing state". At this time, as shown in Figure 5, the acrylic plate 28 is inserted into the diaper 1 such that the vertical direction X of the diaper 1 is parallel to the vertical side 28a when the rectangular acrylic plate is viewed from above (when the acrylic plate is viewed in the thickness direction), and the horizontal direction Y of the diaper 1 is parallel to the horizontal side 28b which is perpendicular to the vertical side 28a of the acrylic plate 28. Furthermore, the acrylic plate 28 is inserted into the diaper 1 such that the vertical center line that bisects the dorsal side 6 (described later) and the ventral side 3 of the diaper 1 in the horizontal direction Y is located near the side of the acrylic plate 28, and the side seal 8 is located near the center of the horizontal side 28b of the acrylic plate 28. The "second intersection angle θ2" and "third intersection angle θ3," described later, are measurements taken when the acrylic plate 28 is inserted inside the diaper 1 to simulate the "wearing state" of the diaper 1, as shown in Figure 5. In this case, the second virtual line L2, the third virtual line L3, and the fourth virtual line L4, which define the second intersection angle θ2 and the third intersection angle θ3, described later, are projected onto the plane 28c of the acrylic plate 28, and each intersection angle is measured. Furthermore, if the length of the crotch area 9 (described later) of diaper 1 is relatively short and the acrylic plate 28 cannot be sufficiently inserted into diaper 1, the crotch area 9 is cut along its entire width in the horizontal direction Y near the center of the length in the vertical direction X, and then the acrylic plate 28 is inserted into diaper 1.

[0017] In this specification, "waist side" and "upper side" mean the side in the vertical direction X (up and down direction) that is closer to the waist opening end Wa of the waist opening 1W and the side that is further away from the leg opening 1L. "Leg side" and "lower side" mean the side in the vertical direction X (up and down direction) that is further away from the waist opening end Wa and the side that is closer to the leg opening 1L. In this specification, "inside in the lateral Y direction" in the diaper 1 in its natural length state (see Figure 4) or in the unfolded and stretched state (see Figure 3) means the side that is closer to the vertical center line CL that bisects the diaper (pant-type absorbent article) in the lateral Y direction. In this specification, with respect to the thickness direction Z, the side of the diaper closer to the wearer's skin when worn is referred to as the "skin side," and the side closer to the clothing is referred to as the "non-skin side." Furthermore, "skin-facing surface" means the surface of the diaper or its components that faces the wearer's skin, i.e., the surface that is relatively close to the wearer's skin. "Non-skin-facing surface" means the surface of the diaper or its components that faces the opposite side (clothing side) from the skin-facing surface, i.e., the surface that is relatively far from the wearer's skin.

[0018] When an infant or toddler puts on diaper 1, they first put their legs through the pair of leg openings 1L, pull up diaper 1, and position diaper 1 around the wearer's waist and groin. In this specification, this series of actions is referred to as the "wearing action." The wearing action may also be performed by a caregiver rather than the wearer of diaper 1. For this reason, in this specification, the main performer of the wearing action is referred to as the "caregiver." In this specification, the state in which diaper 1 is positioned in the normally expected and appropriate wearing position for the wearer is referred to as the "wearing state."

[0019] When a caregiver puts a diaper 1 on a wearer, it is common for the caregiver to insert their hand inside the absorbent pant-type garment and spread it open to create space for the wearer's legs and torso. For example, when putting a diaper 1 on a wearer who is lying on their back, typically, as shown in Figure 7(A), the caregiver inserts their hand from the leg opening 1L to the waist opening 1W of the diaper 1 and spreads the diaper 1 open with both hands. Also, for example, when putting a diaper 1 on a wearer who is standing and holding on, typically, as shown in Figure 7(B), the caregiver inserts their fingers 16 into the waist opening 1W and spreads the diaper 1 open with both hands. In this specification, such a movement by a caregiver to spread the diaper 1 is referred to as the "diaper spreading movement."

[0020] As shown in Figures 1, 2, and 3, the diaper 1 comprises an absorbent body 4 and an outer casing 5 positioned on the non-skin-facing side of the absorbent body 4. The diaper 1 also comprises first to fourth elastic bodies 71 to 74, a leg elastic body 11, and an elastic body 25 for forming a leak-proof cuff. Figure 3 shows the diaper 1 unfolded, with the elastic bodies of each part extended, and spread out flat to achieve the design dimensions, completely eliminating the influence of the elastic bodies. This form is also referred to as the "unfolded and extended state" of the diaper 1. Unfolding the diaper 1 means separating the ventral part 3 and the dorsal part 6 of the side seal 8, which will be described later.

[0021] The absorbent body 4 is fixed to the skin-facing side of the outer casing 5. The absorbent body 4 has at least an absorbent 40 and may further have a surface sheet 2, a back sheet 7, etc. For example, the absorbent body 4 has a configuration in which the back sheet 7, the absorbent 40 and the surface sheet 2 are laminated in the thickness direction Z (see Figure 9). The absorbent 40 includes a liquid-retaining absorbent core and may further include a core wrap sheet that covers the absorbent core. The absorbent body 4 has a dorsal end 106 located on the dorsal side 6, which is the end in the longitudinal direction X, and a ventral end 107 located on the ventral side 3, which is the end in the longitudinal direction X. The materials used in each component of the absorbent body 4 (back sheet 7, absorbent material 40, front sheet 2, etc.) can be any material used in the relevant art without any particular limitations.

[0022] The outer casing 5 includes a plurality of thermoplastic sheets 50. The outer casing 5 is configured, for example, as a laminate of a plurality of thermoplastic sheets 50. The thermoplastic sheet 50 is a sheet material mainly composed of thermoplastic resin. The thermoplastic sheet 50 preferably contains 90% by mass or more of thermoplastic resin, and more preferably consists of 100% by mass of thermoplastic resin. In addition, multiple thermoplastic sheets 50 may also contain cellulosic fibers in addition to thermoplastic fibers. Examples of thermoplastic resins include polyolefins such as polyethylene and polypropylene; polyesters such as polyethylene terephthalate; polyamides such as nylon 6 and nylon 66; polyacrylic acid, polyalkyl methacrylate, polyvinyl chloride, and polyvinylidene chloride. These can be used individually or in combination of two or more. The thermoplastic fibers may be short or long fibers. As thermoplastic fibers, composite fibers such as core-sheath type or side-by-side type, split fibers, irregularly shaped cross-section fibers, and heat-shrinkable fibers can also be used. Examples of cellulose fibers include natural cellulose fibers such as cotton and pulp, and regenerated cellulose fibers such as rayon and cupro. These can be used individually or in combination of two or more types.

[0023] As shown in Figure 3, the outer garment 5 has at least an abdominal portion 3 positioned on the wearer's abdominal side and a dorsal portion 6 positioned on the wearer's back side. The outer garment 5 of this embodiment further includes a crotch portion 9 located between the abdominal portion 3 and the dorsal portion 6 and positioned at the wearer's crotch. In this example, the abdominal portion 3, the crotch portion 9, and the dorsal portion 6 are arranged along the longitudinal direction X. The outer garment 5 also has a shape that is constricted inward in the transverse direction Y at the crotch portion 9. This forms a leg opening 1L (see Figure 1) that follows the wearer's leg opening. The dorsal portion 6 has a dorsal extension portion 60 and a dorsal main body portion 61. The outer edge of the exterior body 5 is preferably constructed to be symmetrical (left-right symmetrical) with respect to the vertical center line CL.

[0024] Furthermore, the outer casing 5 has a pair of side seals 8, each formed by joining the lateral edge 54 of the ventral portion 3 in the lateral direction Y and the lateral edge 55 of the dorsal main body portion 61 in the lateral direction Y. In other words, the right side seal 8 has a configuration in which the right lateral edge 54 of the ventral portion 3 and the right lateral edge 55 of the dorsal main body portion 61 are joined together by overlapping them in the thickness direction Z. The left side seal 8 has a configuration in which the left lateral edge 54 of the ventral portion 3 and the left lateral edge 55 of the dorsal portion 6 are joined together by overlapping them in the thickness direction Z. The side seals 8 are preferably joined by heat sealing or ultrasonic sealing. The lateral edge portion 54 of the ventral portion 3 is a portion having a predetermined width, including the lateral edge 540 which is the lateral edge (lateral edge located on the left and right sides) of the ventral portion 3 in the lateral direction Y. The side edge portion 55 of the dorsal main body portion 61 is a portion having a predetermined width, including the side edge 550 which is the side edge (side edge located on the left and right) of the dorsal main body portion 61 in the lateral direction Y. The width of each of the side edges 54 and 55 is preferably 1.5 mm or more and 10 mm or less, more preferably 2 mm or more and 8 mm or less.

[0025] The outer casing 5 preferably includes, for example, an outer layer sheet 51 and an inner layer sheet 52 as a plurality of thermoplastic sheets 50, as shown in Figure 9. The outer layer sheet 51 is positioned on the non-skin side of the inner layer sheet 52 and constitutes the non-skin facing surface of the outer casing 5. It is preferable that first to fourth elastic bodies 71 to 74 are arranged between the inner layer sheet 52 and the outer layer sheet 51.

[0026] Furthermore, the diaper 1 is further equipped with a disposal tape 12 having a handle portion, which is a pinch portion 12a, positioned on the back side 6 so as to overlap with the absorbent body 4 in a plan view (see Figure 7(A)).

[0027] As will be explained in more detail later, as shown in Figure 1, the dorsal portion 6 of the outer casing 5 of the diaper 1 is equipped with a dorsal extension 60. The dorsal extension 60 protrudes vertically upward from the ventral portion 3, which visually encourages the user to grasp the dorsal portion 6 and pull up the diaper 1. Thus, the diaper 1 is shaped in a way that facilitates the action of grasping the dorsal portion and pulling it up.

[0028] 《Outer structure》 As shown in Figures 1, 2, and 3, the outer garment 5 has a ventral portion 3, a crotch portion 9, and a dorsal portion 6. The dorsal portion 6 has a dorsal extension portion 60 and a dorsal main body portion 61. The ventral portion 3 of the outer garment 5 has a ventral waist end portion 101 that constitutes the waist opening end Wa of the waist opening 1W. The dorsal portion 6 of the outer garment 5 has a dorsal waist end portion 102 that constitutes the waist opening end Wa of the waist opening 1W. The dorsal waist end portion 102 is located further from the pair of leg openings 1L in the longitudinal direction X than the ventral waist end portion 101. The dorsal waist end portion 102 is the end portion (dorsal extension end portion) of the dorsal extension portion 60 in the longitudinal direction X. In the illustrated example, the dorsal waist end portion 102 is a straight line extending in the transverse direction Y, but is not limited to this, and may be a curved shape (rounded shape) that gently bulges upward in the longitudinal direction X, for example. Multiple elastic bodies are arranged in the ventral portion 3 and the dorsal portion 6. Details will be described later.

[0029] [Dorsal structure] As shown in Figures 3, 8(A), and 8(B), the dorsal portion 6 of the outer casing 5 has a dorsal extension 60 and a dorsal main body 61. The dorsal extension 60 extends in the vertical direction X (up and down direction) from the ventral waist end 101 to the dorsal waist end 102. In the diaper 1, the dorsal extension 60 is the portion that protrudes upward from the ventral waist end 101. The dorsal main body 61 is the portion of the dorsal portion 6 excluding the dorsal extension 60. In other words, the dorsal main body 61 is the portion that is in the same position as the ventral portion 3 in the vertical direction X, while the dorsal extension 60 is the portion that does not face the ventral portion 3 and protrudes upward in the vertical direction X. As shown in Figures 1 and 3, the boundary between the dorsal extension 60 and the dorsal main body 61 (shown by a hypothetical dashed line) is denoted by reference numeral 103. The length of the dorsal extension portion 60 in the vertical direction X (i.e., the length from the boundary portion 103 to the dorsal waist end portion 102) is preferably, for example, 10 mm to 40 mm, from the viewpoint of good pulling-up operation of the diaper 1, effective suppression of the dorsal extension portion 60 rolling up, and effective suppression of leakage of excrement from the dorsal side. The length of the dorsal extension portion 60 in the vertical direction X refers to the minimum length. As shown in Figures 1 and 3, when the dorsal waist end portion 102 is a straight line parallel to the transverse direction Y, the length of the dorsal extension portion 60 in the vertical direction X (the length from the dorsal waist end portion 102 to the boundary portion 103 in the vertical direction X) is equal across the entire width in the transverse direction Y. However, when the dorsal waist end portion 102 is a curved shape that is convex upward in the vertical direction X, the length of the dorsal extension portion 60 in the vertical direction X is not equal across the entire width in the transverse direction Y. In this configuration, the length of the portion of the dorsal extension 60 where the length in the longitudinal direction X is minimized (minimum length) is defined as "the length of the dorsal extension 60 in the longitudinal direction X". The longer the dorsal extension 60, the better it can prevent loose stools and other excrement from leaking out. However, if it is too long, it becomes difficult to pull up the diaper 1, and the dorsal extension 60 is more likely to curl up. Therefore, it is preferable that the length of the dorsal extension 60 be 40 mm or less. On the other hand, if the dorsal extension 60 is too short, it is easy for the dorsal extension 60 to be folded inward by hand when pulling up the diaper 1, making it difficult to pull up. Therefore, it is preferable that the length of the dorsal extension 60 be 10 mm or more.

[0030] As shown in Figures 3, 8(A), and 8(B), the back main body portion 61 of the back portion 6 is divided into three equal parts in the vertical direction X (up and down direction), and is divided into three regions: the upper back portion 62, the middle back portion 63, and the lower back portion 64, which are located in order in the vertical direction X from the side closest to the waist opening 1W. The back portion 6 is divided into four parts: the back extension portion 60, the upper back portion 62, the middle back portion 63, and the lower back portion 64, which are arranged in order from the waist opening 1W toward the leg opening 1L. Furthermore, as shown in Figures 3, 8(A), and 8(B), the back main body portion 61 has a first region A that is adjacent to the back extension portion 60 in the vertical direction X, and whose length in the vertical direction X is the same as the length of the back extension portion 60 in the vertical direction X. The first region A is included in the upper back portion 62.

[0031] As shown in Figures 1 to 3, the dorsal extension portion 60 has a pair of dorsal extension side edges 104 facing each other in the lateral direction Y, and a pair of side reinforcing portions 105 provided on each of the pair of dorsal extension side edges 104. Each pair of dorsal extension side edges 104 extends in the vertical direction X. The dorsal extension side edges 104 are portions having a predetermined width, including the dorsal extension side edges 1040, which are the side edges (side edges located on the left and right) of the dorsal extension portion 60 in the lateral direction Y. The width of the dorsal extension side edges 104 is preferably 1.5 mm or more and 10 mm or less, more preferably 2 mm or more and 8 mm or less. Details of the side reinforcing portions 105 and the side seals 8 will be described later.

[0032] [Structure of the ventral region] As shown in Figures 3, 8(A), and 8(B), the ventral portion 3 is divided into three regions by dividing the ventral portion 3 into three equal parts in the longitudinal direction X: the upper ventral portion 32, the middle ventral portion 33, and the lower ventral portion 34, which are arranged in order from the waist opening 1W toward the leg opening 1L.

[0033] In the longitudinal direction X, the ventral upper portion 32 is in the same position as the dorsal upper portion 62, the ventral middle portion 33 is in the same position as the dorsal middle portion 63, and the ventral lower portion 34 is in the same position as the dorsal lower portion 64. In this specification, "being in the same position in the longitudinal direction X" means that, in the unfolded and extended state shown in Figure 8(B), the ventral portion and the dorsal portion are adjacent and their position and length in the longitudinal direction X coincide.

[0034] In diaper 1, the ventral portion 3 and the dorsal main body portion 61 are joined by a side seal 8 to form a tubular waist portion. The ventral upper portion 32 and the dorsal upper portion 62 are joined by a side seal 8 to form a ring-shaped waist portion. This waist portion is positioned approximately around the wearer's waist when worn. Similarly, the ventral middle portion 33 and the dorsal middle portion 63 are joined to form a ring, which is positioned approximately near the wearer's ilium when worn. Similarly, the ventral lower portion 34 and the dorsal lower portion 64 are joined to form a ring. On the other hand, the dorsal extension portion 60 is not ring-shaped because there is no ventral portion at the same position in the longitudinal direction X, and has a pair of dorsal extension side edges 104 that are free ends on both sides in the transverse direction Y.

[0035] 《Composition of the absorbent body》 Figure 9 is a schematic cross-sectional view of the side seal 8. Although the absorbent body 4 does not exist in the side seal 8, the absorbent body 4 is shown in Figure 9 for convenience to explain the arrangement relationship between the absorbent body 4 and the outer casing 5 in the article thickness direction (Z-axis direction). As shown in Figure 9, the outer casing 5 is folded back towards the skin-facing side at the ventral waist end 101 and the dorsal waist end 102. This folded portion is positioned to cover the dorsal end 106 and the ventral end 107 of the absorbent body. The same applies to Figures 12 and 13, which describe the second and third embodiments later.

[0036] As shown in Figure 9, the absorbent body 4 comprises a liquid-permeable surface sheet 2 that forms the skin side, a liquid-impermeable (including water-repellent) back sheet 7 that forms the non-skin side, and a liquid-retaining absorbent 40 positioned between the surface sheet 2 and the back sheet 7. The absorbent 40 and the surface sheet 2 are bonded together with an adhesive (not shown). The absorbent 40 and the back sheet 7 are bonded together with an adhesive (not shown).

[0037] As shown in Figure 3, each side of the absorbent body 4 along the longitudinal direction X is provided with a leak-proof cuff 24, which has an elastic body 25 for forming a leak-proof cuff that is stretched in the longitudinal direction X. The leak-proof cuff 24 is made of a material that is impermeable to liquid or water-repellent and breathable. The elastic body 25 for forming the leak-proof cuff is provided near the free end 24a of the leak-proof cuff 24. When the diaper 1 is worn, the contraction of the elastic body 25 causes the free end 24a side of the leak-proof cuff to stand up, forming a three-dimensional gather 15, which prevents the leakage of bodily fluids in the lateral direction Y. In addition, when the diaper 1 is pulled up, the contraction force of the elastic body 25 makes it easier to pull the absorbent body 4 up to the vicinity of the wearer's crotch.

[0038] In diaper 1, the total length of the absorbent body 4 in the vertical direction X is slightly longer than the total length of the absorbent material 40 in the vertical direction X. The ends 106 and 107 of the absorbent body 4 in the vertical direction X are located closer to the waist end than the ends of the absorbent material 40 in the vertical direction X.

[0039] The absorbent body 40 of the absorbent main body 4 has an absorbent core (not shown) and a core wrap sheet (not shown).

[0040] A core wrap sheet is a liquid-permeable sheet that covers at least the skin-facing side of an absorbent core. Typically, the core wrap sheet is configured to cover the entire surface of the absorbent core, including both the skin-facing and non-skin-facing sides. Examples of core wrap sheets include tissue paper made of hydrophilic fibers and liquid-permeable nonwoven fabrics.

[0041] The absorbent core contains a superabsorbent polymer and pulp fibers. Specifically, the absorbent core is composed of, for example, an aggregate of hydrophilic fibers such as cellulose including pulp fibers, an aggregate of the hydrophilic fibers and a superabsorbent polymer, or a laminated structure in which a superabsorbent polymer is supported between two absorbent sheets.

[0042] As shown in Figure 1, the dorsal end 106 of the absorbent body is located closer to the leg opening 1L in the longitudinal direction X than the boundary 103. In other words, the absorbent body 4 is not positioned on the dorsal extension 60. This prevents the soft stool absorbed by the absorbent body 4 from moving to the dorsal extension 60, and prevents the soft stool from leaking from the dorsal waist end 102 of the outer casing 5.

[0043] <Configuration of side seal and side reinforcement section> A pair of side seals 8, each extending in a direction including the longitudinal X component, cause the ventral portion 3 and the dorsal main body portion 61 to form a tubular shape that conforms to the wearer's waist, forming the waist opening 1W and leg openings 1L of the diaper 1. As shown in Figure 10, the side seals 8 typically include multiple sealing portions S.

[0044] In the side seal 8, the sealing portion S is the portion where the thermoplastic sheets 50 of both the ventral portion 3 and the dorsal main body portion 61 are fused and joined together. The sealing portion S is joined, for example, by pressurizing means and / or heating means, specifically by heat sealing or ultrasonic sealing. Multiple sealing portions S are arranged spaced apart in the longitudinal direction X and extend in the transverse direction Y. By arranging the multiple sealing portions S spaced apart in the longitudinal direction X, if one sealing portion S peels off, it is possible to prevent the entire side seal 8 from peeling off along the longitudinal direction X.

[0045] The pair of side reinforcement portions 105 are provided on the pair of back extension side edges 104 of the back extension portion 60, are continuous with the side seal 8, and extend in a direction including a component in the longitudinal direction X. As shown in Figure 10, the side reinforcement portion 105 includes multiple seal portions S, similar to the side seal 8. In Figure 3, the area of ​​the side seal 8 is represented by dots, and the area of ​​the side reinforcement portion 105 is represented by diagonal lines.

[0046] In the example shown in Figure 10, the sealing portion S has a rectangular shape with the transverse direction Y as its longitudinal direction. Multiple sealing portions S are intermittently arranged along the longitudinal direction X.

[0047] As shown in Figure 10, in the side seal 8 (side reinforcement portion 105), the rectangular area surrounding the entire contour of the multiple seal portions S is called the seal region B. The seal region B is a region with higher rigidity compared to the region without seal portions S. Thus, the side seal 8 (side reinforcement portion 105) includes a rectangular, relatively rigid seal region B. The rigidity of the side reinforcement portion 105 is increased by the inclusion of the seal region B, and the dorsal extended side edge portion 104 is reinforced.

[0048] As shown in Figure 10, the width of the rectangular side seal 8, which extends in a band shape in the vertical direction X (corresponding to the width of the side edges 54 and 55), is defined as extending from the side edge on the inside of the seal area B in the horizontal direction Y to the side edge 540 of the ventral part 3 and the side edge 550 of the dorsal main body part 61. The side edge located on the lateral Y side of the side seal 8 is referred to as the inner side seal side edge 8d. This inner side seal side edge 8d coincides with the side edge located on the lateral Y side of the seal region B. The side edge located on the lateral Y-outward side of the side seal 8 is referred to as the outer side seal side edge 8c. This outer side seal side edge 8c coincides with side edges 540 and 550. As shown in Figure 10, each sealing portion S of the side seal 8 does not reach the side edges 540 and 550 in the lateral direction Y, and the side edges located on the lateral Y outer side of the sealing region B are located lateral Y inward from the side edges 540 and 550. In other words, the range of each of the left and right side seals 8 is the area from the side edge (inner side seal side edge 8d) that extends in the vertical direction X and is located inside the lateral direction Y of the rectangular seal area B, to the side edges 540 and 550.

[0049] As shown in Figure 10, the width range of the rectangular side reinforcement portion 105, which extends in a band shape in the vertical direction, is from the side edge on the inside of the seal area B in the lateral direction Y to the dorsal extension side edge 1040 of the dorsal extension portion 60. The side edge located on the inner side in the lateral direction Y of the side reinforcement portion 105 is referred to as the inner side reinforcement portion side edge 105d. This inner side reinforcement portion side edge 105d coincides with the side edge located on the inner side in the lateral direction Y of the seal region B. The side edge located on the lateral Y-outward side of the side reinforcement portion 105 is referred to as the outer side reinforcement portion side edge 105c. This outer side reinforcement portion side edge 105c coincides with the dorsal extension side edge 1040. As shown in Figure 10, each sealing portion S of the side reinforcement portion 105 does not reach the dorsal extending side edge 1040 in the lateral direction Y, and the side edges located on the outside in the lateral direction Y of the sealing region B are located inward in the lateral direction Y than the dorsal extending side edge 1040. In other words, in the dorsal extension portion 60, the range of each of the left and right pair of side reinforcing portions 105 is the region from the inner side reinforcing portion side edge 105d, which is the side edge extending in the vertical direction X located inside the lateral direction Y of the rectangular seal region B, to the dorsal extension side edge 1040.

[0050] The side reinforcement portion 105 is a highly rigid part due to the presence of multiple sealing portions S. By providing the side reinforcement portion 105 on the dorsal extension side edge portion 104, the rigidity of the pair of dorsal extension side edge portions 104 is increased, making the dorsal extension portion 60 less likely to curl up. Furthermore, because an elastic body is placed in the dorsal extension portion 60, the contraction force of the elastic body gives the dorsal extension portion 60 thickness and robustness, making the dorsal extension portion 60 less likely to curl up. In addition, because the side seal 8 and the side reinforcement portion 105 are continuous, the occurrence of bending of the dorsal extension portion 60 starting from the boundary portion 103 is suppressed. Moreover, since the pair of side reinforcement portions 105 are continuous with the side seal 8 and have a similar configuration including multiple sealing portions S, the diaper 1 can be manufactured simply without increasing the manufacturing process or materials.

[0051] Each pair of side seals 8 has an upper end portion 8a and a lower end portion 8b, which form both ends in the vertical direction X. The upper end portion 8a and the lower end portion 8b each extend in the horizontal direction Y. Each pair of side seals 8 is continuous with a side reinforcing portion 105 provided on a pair of back extension side edges 104 of the back extension portion 60.

[0052] In the continuous side seal 8 and side reinforcement portion 105, the upper end portion 8a of the side seal is located at the boundary between the side seal 8 and the side reinforcement portion 105. The upper end portion 8a of the side seal is the waist-side end of the side seal 8. The lower end portion 8b of the side seal is the leg-side end of the side seal 8.

[0053] As shown in Figure 4, etc., in diaper 1, and diapers 1A and 1B described later, a first point P1 is set on the upper end 8a of the side seal. Specifically, the first point P1 is the outermost point in the lateral direction Y of the upper end 8a of the side seal. Also, a second point P2 is set on the lower end 8b of the side seal. Specifically, the second point P2 is the outermost point in the lateral direction Y of the lower end 8b of the side seal. Furthermore, in diaper 1 in its natural length state, the straight line passing through the first point P1 and the second point P2 is referred to as the "first virtual line L1". In diaper 1 in its natural length state, the band-shaped side seal 8 extends in a nearly straight line.

[0054] As shown in Figure 6, the pair of side reinforcement portions 105 each have an upper end portion 105a and a lower end portion 105b, which constitute both ends in the vertical direction X. The upper end portion 105a and the lower end portion 105b each extend in the horizontal direction Y. The upper end portion 105a is located at the back waist end portion 102. The lower end portion 105b corresponds to the boundary portion 110 between the side seal 8 and the side reinforcement portion 105, and is located at the same position as the upper end portion 8a of the side seal. In Figure 6, the boundary portion 110 is virtually shown by a thick dashed line.

[0055] As shown in Figures 4 to 6, in diaper 1, and diapers 1A and 1B described later, a third point P3 is set on the upper end 105a of the side reinforcement. Specifically, in diaper 1 in its natural length state as shown in Figure 4, the third point P3 is the outermost point in the lateral direction Y of the upper end 105a of the side reinforcement. Also, a fourth point P4 is set on the lower end 105b of the side reinforcement. Specifically, in diaper 1 in its natural length state as shown in Figure 4, the fourth point P4 is the outermost point in the lateral direction Y of the lower end 105b of the side reinforcement. The fourth point P4 is in the same position as the first point P1. Furthermore, in diaper 1 in its natural length state and in its worn state, the straight line passing through the third point P3 and the fourth point P4 is referred to as the "second virtual line L2". The direction of the second virtual line L2 roughly corresponds to the extension direction of the band-shaped side reinforcement 105. Furthermore, in the diaper 1 when worn, the straight line parallel to the vertical direction X (up and down direction) passing through the fourth point is referred to as the "third virtual line L3".

[0056] As shown in Figure 5, the fifth point P5 is defined as the center of the side seal 8 in the vertical direction X and the outermost point in the horizontal direction Y of the diaper 1 in its unfolded and extended state (see Figure 3). Also, as shown in Figure 5, the line passing through the fifth point P5 and the third point P3 in the diaper 1 in its worn state is referred to as the "fourth imaginary line L4". The fifth point P5 and the fourth imaginary line L4 are similarly defined for diapers 1A and 1B in Figure 14, which will be described later.

[0057] Elastic body In the diaper 1 of this embodiment, as shown in Figures 3, 8(A), and (B), a plurality of first elastic bodies 71, second elastic body 72, third elastic body 73, and fourth elastic body 74 extending in the lateral direction Y are arranged on the ventral side 3 and dorsal side 6 of the outer casing 5. The fineness of each of the first to fourth elastic bodies 71 to 74 is different, and in Figures 3, 8(A), and (B), elastic bodies with different finenesses are shown with different wire types.

[0058] The first elastic body 71a and the first elastic body 71b are elastic bodies with the same fineness and elongation ratio, differing only in their placement in the same area. Unless there is a need to distinguish between them, they are referred to as the first elastic body 71. In the figure, the first elastic body 71 is shown by a dashed line. The second elastic bodies 72a, 72b, and 72c are elastic bodies that have the same fineness but differ in their placement and elongation rate depending on the location. Unless otherwise specified, they are referred to as the second elastic body 72. In the figure, the second elastic body 72 is shown by a long dashed line. Third elastic bodies 73a, 73b, and 73c are elastic bodies with the same fineness and elongation ratio, differing only in their placement. Unless otherwise specified, they are referred to as the third elastic body 73. In the figure, the third elastic body 73 is shown by a short dashed line. The fourth elastic body 74a and the fourth elastic body 74b are elastic bodies with the same fineness and elongation ratio, differing only in their placement. Unless there is a need to distinguish between them, they are referred to as the fourth elastic body 74. In the figure, the fourth elastic body 74 is shown by a dashed line.

[0059] From the viewpoint of ensuring the overall elasticity of the girth, it is preferable that both ends of the elastic bodies 71-74, which are arranged in the ventral portion 3 and the dorsal main body portion 61 respectively, be located in or near the side seal 8. Specifically, it is preferable that the distance of the end from the side seal 8 in the lateral direction Y is 10 mm or less, and it is more preferable that the distance is 0 mm and the end is located within the side seal 8.

[0060] From the viewpoint of ensuring stretchability over almost the entire width of the dorsal extension 60, it is preferable that both ends of the first elastic body 71a in the longitudinal direction are located on or near the side reinforcement portion 105. Specifically, it is preferable that the distance of the end from the side reinforcement portion 10 in the lateral direction Y is 10 mm or less, and it is more preferable that the distance is 0 mm and the end is located within the side reinforcement portion 10.

[0061] The elongation rates of each of the first to fourth elastic bodies 71 to 74 represent the ratio of the length of the elastic body when the pants-type absorbent article is unfolded and stretched to the length of the elastic body when it is removed from the pants-type absorbent article at its natural length. The method for measuring the elongation rate will be described later. In other words, the lower the elongation rate, the smaller the elastic force when each elastic body is stretched tends to be. The elongation rate of the elastic body can be adjusted during manufacturing by adjusting the degree of elongation of each elastic body placed in the outer casing 5. During manufacturing, for example, the elastic body is stretched to a predetermined length, adhesive is applied to the elastic body, and the elastic body is fixed to the thermoplastic sheet 50 of the outer casing 5.

[0062] Figure 9 is a schematic cross-sectional view of the side seal 8 and side reinforcement portion 105 of the diaper 1 of this embodiment. As shown in Figure 3, when the unfolded diaper 1 is viewed from above, the absorbent body 4 is not present in the area where the side seal 8 and side reinforcement portion 105 are provided. However, in Figure 9, the absorbent body 4 is shown to explain the positional relationship in the longitudinal direction X between the dorsal end 106 and ventral end 107 of the absorbent body 4 and the side seal 8.

[0063] Multiple first to fourth elastic bodies 71 to 74 are arranged between multiple thermoplastic sheets 50 of the outer casing 5. In the example shown in Figure 9, the multiple elastic bodies 71 to 74 are arranged extending in the lateral direction Y between the outer layer sheet 51 and the inner layer sheet 52. These first to fourth elastic members 71 to 74 provide elasticity to the waist of the diaper 1, making it easier to put on and maintaining a good fit when worn. Furthermore, "the first to fourth elastic bodies 71 to 74 extend in the lateral direction Y" means that in the unfolded and extended state, the first to fourth elastic bodies 71 to 74 extend in the lateral direction Y. However, the above expression is not limited to the first to fourth elastic bodies 71 to 74 being parallel to the lateral direction Y in the unfolded and extended state, but also includes the state in which the whole extends in the lateral direction Y. In this embodiment, an example is given in which all of the elastic bodies 71 to 74 are parallel to the lateral direction Y.

[0064] Furthermore, as shown in Figures 1 and 3, the outer casing 5 may include, in addition to the first to fourth elastic bodies 71 to 74, a leg elastic body 11 positioned around the leg opening 1L. The leg elastic body 11 forms leg gathers. The leg elastic body 11 may extend laterally in the Y direction near the side seal 8 and intersect with the fourth elastic body 74, which is an elastic body that forms waist gathers. In this way, the presence of a region where the leg gathers and waist gathers are parallel and intersect makes it easier to pull up the crotch area 9 of the diaper 1 to near the wearer's crotch when pulling up the diaper 1.

[0065] The first to fourth elastic bodies 71 to 74, the leg elastic body 11, and the leak-proof cuff forming elastic body 25 can preferably be thread-like (e.g., elastic thread) or string-like (e.g., flat elastic) materials with a rectangular, square, circular, or polygonal cross-section, or multifilament type thread-like materials. The materials for the first to fourth elastic bodies 71 to 74, the leg elastic body 11, and the leak-proof cuff forming elastic body 25 can be those conventionally used in absorbent articles such as disposable diapers, and are not particularly limited. Examples include synthetic rubbers such as styrene-butadiene, butadiene, isoprene, and neoprene, natural rubber, EVA, stretchable polyolefin, and polyurethane.

[0066] [Details of the construction of the side seal and side reinforcement area in the natural length state and when worn] As shown in Figure 4, in the diaper 1 in its natural length state, the angle formed by the intersection of the first virtual line L1 and the second virtual line L2 is defined as the first intersection angle θ1. As shown in Figures 5 and 6, in the diaper 1 in its worn state, the angle formed by the intersection of the second virtual line L2 and the third virtual line L3 is defined as the second intersection angle θ2.

[0067] Diaper 1 has one or more elastic bodies in the dorsal extension portion 60 and the dorsal upper portion 62, respectively. As shown in Figure 4, in its natural length state, the diaper 1 has a configuration in which the first crossing angle θ1 is between 5 degrees and 30 degrees, and the third point P3 is located laterally inward in the Y direction from the first imaginary line L1 (hereinafter referred to as the "first configuration"). As shown in Figures 5 and 6, when the diaper 1 is worn, the second crossing angle θ2 is between 10 degrees and 70 degrees, and the third point P3 is located on the dorsal side in the anterior-posterior direction relative to the third imaginary line (hereinafter referred to as the "second configuration"). Furthermore, diaper 1 has a configuration in which the second crossing angle θ2 is larger than the first crossing angle θ1 (hereinafter referred to as the "third configuration").

[0068] The first to third configurations described above can be realized by appropriately adjusting the fineness, elongation rate, and spacing of the elastic bodies arranged in the dorsal extension portion 60 and the dorsal upper portion 62, respectively.

[0069] As shown in Figure 4, in its natural length state, the diaper 1 has the "first configuration" described above, and the second virtual line L2 corresponding to the extension direction of the side reinforcement portion 105 extends more obliquely than the first virtual line L1 corresponding to the extension direction of the side seal 8, such that the upper side is more inward in the lateral direction Y. In other words, the second virtual line L2 extends in a direction that contains a larger lateral Y component than the first virtual line L1. In the diaper 1 in its natural length state, no stretching force is applied to the elastic body, so as shown in Figure 4, the value of the first intersection angle θ1 is relatively small, and the side seal 8 and the side reinforcement portion 105 continuous therewith extend in a nearly straight line overall, and in the diaper 1, the waist portion (the part where the dorsal and ventral portions are joined) has a shape that narrows from the bottom to the top such that its lateral Y dimension (width dimension) continuously decreases.

[0070] By having the above-described "first configuration" in a diaper 1 in its natural length state, it can be made into a diaper 1 that is comfortable against the skin for the caregiver. In other words, as shown in Figure 7(A), when a caregiver inserts their hand into the leg opening 1L of the diaper 1 and out the waist opening 1W, and then spreads the diaper 1 with their hand inside, a force is applied to the dorsal upper part 62, which is joined to the ventral upper part 32 by the side seal 8 and forms a ring, in the lateral direction Y. In contrast, the dorsal extension 60 is not ring-shaped, and a first elastic body 71a extending in the lateral direction Y is provided on the dorsal extension 60, so a force is less likely to be applied to the dorsal extension 60 in the lateral direction Y. For this reason, when spreading the diaper, the side reinforcement part 105 (dorsal extension side edge part 104) tends to collapse inward in the lateral direction Y, and furthermore, because the first intersection angle θ1 is 5 degrees or more in the natural length state, the highly rigid side reinforcement part 105 is less likely to come into contact with the caregiver's fingers 16. Furthermore, by setting the first crossing angle θ1 to 30 degrees or less in the natural length state, it is possible to suppress the side reinforcement portion 105 from excessively tilting inward in the lateral Y direction during diaper spreading (in other words, the Y-direction component of the second virtual line L2 becomes excessively large), making it less likely for the area near the dorsal extension side edge portion 104 to fold inward into the diaper. As a result, the diaper 1 can be worn so that the dorsal extension portion 60 is in the correct position, and the leakage prevention function of excrement provided by the dorsal extension portion 60 can be effectively realized. Similarly, as shown in Figure 7(B), when a caregiver inserts their fingers into the inside of the diaper 1 through the waist opening 1W and spreads the diaper 1, the presence of the first structure in the diaper 1 causes the side reinforcement portion 105 (dorsal extended side edge portion 104) to collapse inward in the lateral direction Y, making it less likely for the highly rigid side reinforcement portion 105 to come into contact with the caregiver's fingers 16. In addition, because excessive collapse of the side reinforcement portion 105 inward in the lateral direction Y is suppressed, the area around the dorsal extended side edge portion 104 is less likely to fold inward into the diaper, and the excrement leakage prevention function of the dorsal extended portion 60 can be effectively realized.

[0071] Thus, by having the first configuration, the diaper 1 can be made more comfortable against the skin, as rigid parts such as the side reinforcement are less likely to come into contact with the caregiver's fingers when the diaper is unfolded, making it easier to put on smoothly. In addition, the diaper 1 can effectively exhibit the function of preventing leakage of excrement by the dorsal extension 60.

[0072] Furthermore, in the diaper 1 of this embodiment, an elastic body is provided in the dorsal extension portion 60, and the diaper 1 in the worn state has the above-mentioned "second configuration," making it a diaper 1 that is comfortable against the wearer's skin. This will be explained below.

[0073] As shown in Figure 3, in the unfolded and extended state of diaper 1, the lateral Y dimension of the dorsal portion 6 and the lateral Y dimension of the ventral portion 3 are the same. In the worn diaper 1, the waist area (the upper dorsal portion 62 and upper ventral portion 32, which are joined by the side seal 8 and connected in a ring shape) is subjected to a force that stretches laterally in the Y direction from the wearer. However, the dorsal extension portion 60 is not ring-shaped, making it difficult for a force to stretch laterally in the Y direction to be applied to it, and thus the contractile force of the first elastic body 70a located in the dorsal extension portion 60 is easily exerted. As a result, the contractile force of the first elastic body 71a located in the dorsal extension portion 60 also affects the upper dorsal portion 62, which is adjacent to the dorsal extension portion 60 in the vertical X direction, and the lateral Y dimension of the upper dorsal portion 62 tends to be shorter than the lateral Y dimension of the upper ventral portion 32. Consequently, in the worn diaper 1, the side reinforcement portion 105 tends to be located more towards the back than near the sides of the wearer's waist (near the flank), and the highly rigid side reinforcement portion 105 is less likely to come into contact with the sides of the wearer's waist. Therefore, for example, when the wearer is sleeping on their side, the side reinforcement portion 105 is less likely to come into contact with the skin, and when the wearer turns over in their sleep, the side reinforcement portion 105 is less likely to dig into the skin, resulting in a diaper 1 that is gentle on the skin and provides superior comfort. Furthermore, by having the "second configuration" when the diaper 1 is worn, it is possible to make the diaper 1 even more comfortable against the skin. That is, even if the lower end 105b of the side reinforcement is located near the side of the wearer's waist, by configuring the second imaginary line L2 (corresponding to the side reinforcement 105) to be oblique at a second intersection angle θ2 of 10 degrees or more, such that the third point P3 at the upper end 105a of the side reinforcement is closer to the back than the fourth point P4 at the lower end 105b of the side reinforcement, the side reinforcement 105 will not be in contact with the side of the wearer's waist across its entire surface, resulting in a diaper 1 that is more comfortable against the skin. In addition, by setting the second intersection angle θ2 to 70 degrees or less, it is easier to ensure that the area of ​​the dorsal extension 60 that covers the wearer's back is sufficiently secured, and the function of preventing leakage of excrement by the dorsal extension 60 can be obtained more reliably.

[0074] Furthermore, diaper 1 has the above-mentioned "third configuration" (where the first intersection angle θ1 is smaller than the second intersection angle θ2). Having the "third configuration" means that when diaper 1 is worn, the side reinforcement portion 105a of the side reinforcement portion is more inclined towards the lateral Y-direction inward of the dorsal extension portion 60 than the side reinforcement portion 105a of diaper 1 in its natural length state, making it more oblique (the Y-direction component of the second imaginary line L2 becomes larger). The presence of the third component in diaper 1 effectively suppresses the occurrence of folds near the dorsal extended side edge 104 caused by excessive bending of the side reinforcement portion 105 inward in the lateral direction Y during unfolding, while also ensuring that the side reinforcement portion 105 does not easily come into contact with the side of the wearer's waist when worn.

[0075] As described above, the diaper 1 of the present invention, having the above-mentioned first to third configurations, makes it less likely for the side reinforcement portion 105 to come into contact with the fingers or hands when a caregiver is spreading the diaper, and less likely for folds to occur near the dorsal extended side edge portion 104. Furthermore, when worn, the side reinforcement portion 105 is less likely to come into contact with the sides of the wearer's waist, and the function of preventing leakage of excrement by the dorsal extended portion 60 can be obtained more reliably. Thus, the diaper 1 is comfortable against the skin and the excrement prevention function by the dorsal extended portion 60 can be effectively performed.

[0076] 《Specific examples of elastic bodies》 The following are examples of the fineness and elongation ratio of the multiple elastic bodies arranged in the outer casing 5 to realize the first, second, and third configurations described above. However, the fineness and elongation ratio are not limited to those listed here. Each elastic body (first to fourth elastic bodies 71 to 74) extends along the lateral direction Y and is intermittently arranged along the longitudinal direction X.

[0077] The first elastic material 71 (71a, 71b) is an elastic material with a fineness of 470 dtex and an elongation ratio of 3.2 times. The second elastic material 72a is an elastic material with a fineness of 310 dtex and an elongation ratio of 2.8 times. The second elastic bodies 72b and 72c are elastic bodies with a fineness of 310 dtex and an elongation ratio of 3.5 times. The third elastic material 73 (73a, 73b, and 73c) is an elastic material with a fineness of 780 dtex and an elongation ratio of 2.7 times. The fourth elastic material 74 (74a, 74b) is an elastic material with a fineness of 620 dtex and an elongation ratio of 2.5 times.

[0078] As shown in Figure 8(B), in diaper 1, the first elastic body 71 includes three first elastic bodies 71a and one first elastic body 71b. The three first elastic bodies 71a are located in the dorsal extension 60. The one first elastic body 71b is located in the dorsal upper part 62. The second elastic body 72 includes two second elastic bodies 72a, five second elastic bodies 72b, and one second elastic body 72c. The two second elastic bodies 72a are located in the dorsal upper part 62. The five second elastic bodies 72b are located in the ventral upper part 32. The one second elastic body 72c is located in the ventral middle part 33. The third elastic body 73 includes two third elastic bodies 73a, two third elastic bodies 73b, and four third elastic bodies 73c. ​​The two third elastic bodies 73a are located in the dorsal upper part 62. The two third elastic bodies 73b are located in the dorsal middle part 63. The four third elastic bodies 73c are located in the ventral middle part 33. The fourth elastic body 74 includes four fourth elastic bodies 74a and four fourth elastic bodies 74b. The four fourth elastic bodies 74a are located in the dorsal lower part 64. The four fourth elastic bodies 74b are located in the ventral lower part 34.

[0079] As shown in Figure 8(B), in the dorsal portion 6, the four first elastic bodies 71, the two second elastic bodies 72, and the four third elastic bodies 73 are intermittently arranged at equal intervals (for example, a pitch of 5.5 mm) in the vertical direction X. In the dorsal portion 6, the spacing between the two upper fourth elastic bodies 74a and the spacing between the two lower fourth elastic bodies 74a is the same, and for example, their pitch is 5.5 mm. In the ventral portion 3, the six second elastic bodies 72 and the four third elastic bodies 73 are intermittently arranged at equal intervals (for example, a pitch of 5.5 mm) in the longitudinal direction X. In the ventral portion 3, the spacing between the two upper fourth elastic bodies 74b and the spacing between the two lower fourth elastic bodies 74b are the same, and their pitch is, for example, 5.5 mm.

[0080] The first to fourth elastic bodies 71 to 74 are each positioned between a pair of side reinforcing portions 105 or between a pair of side seals 8, extending in the lateral direction Y across the entire width of the lateral direction Y, and are arranged to be expandable and contractible in the lateral direction Y. The first to fourth elastic bodies 71 to 74 include continuous elastic bodies that have not been treated to prevent elastic stretching, such as by cutting, and discontinuous elastic bodies that have been treated in part to prevent elastic stretching, such as by cutting. The continuous elastic material exhibits continuous stretchability across the entire width in the lateral direction Y, between a pair of side reinforcement sections 105 or between a pair of side seals 8. The discontinuous elastic body is an elastic body that has been treated so that a portion of the area overlapping with the absorbent body 4 in a plan view is cut off, thereby preventing it from having elastic stretchability. The discontinuous elastic body does not exhibit elastic stretchability in the central part of the diaper 1 in the lateral direction Y, but exhibits elastic stretchability on both sides in the lateral direction Y. In this embodiment, an elastic body that has been treated so that a portion of it does not exhibit elastic stretchability by cutting is used as the discontinuous elastic body, but it is also possible to have a configuration in which no elastic body is placed in the area where elastic stretchability is not exhibited.

[0081] One or more elastic bodies are arranged in the dorsal extension 60. In this embodiment, as shown in Figure 8(B), three first elastic bodies 71a are arranged in the dorsal extension 60, which does not have a corresponding portion in the ventral portion 3. The first elastic bodies 71a are continuous elastic bodies. The dorsal extension 60 has a pair of dorsal extension side edges 104 facing each other in the lateral direction Y, a plurality of first elastic bodies 71a, and a pair of side reinforcing portions 105. The plurality of first elastic bodies 71a are arranged between the pair of dorsal extension side edges 104.

[0082] One or more elastic bodies are arranged on the upper dorsal portion 62. In this embodiment, as shown in Figure 8(B), one first elastic body 71b, two second elastic bodies 72a, and two third elastic bodies 73a are arranged on the upper dorsal portion 62 from top to bottom. All of these elastic bodies are continuous elastic bodies. Furthermore, the upper dorsal portion 62 includes a first region A. In the first region A, one first elastic body 71b and two second elastic bodies 72a are arranged in order from top to bottom.

[0083] As shown in Figure 8(B), one or more elastic bodies are arranged in the ventral upper part 32. In this embodiment, five second elastic bodies 72b are arranged in the ventral upper part 32. All of the elastic bodies are continuous elastic bodies.

[0084] As shown in Figure 8(B), two third elastic bodies 73b are arranged in the dorsal intermediate section 63, from top to bottom. Of the two third elastic bodies 73b, the upper one is a continuous elastic body, and the lower one is a discontinuous elastic body. Note that one or more elastic bodies may be arranged in the dorsal intermediate section 63, or no elastic bodies may be arranged there.

[0085] As shown in Figure 8(B), in the ventral middle section 33, one second elastic body 72c and four third elastic bodies 73c are arranged in order from top to bottom. Of the four third elastic bodies 73c, the two upper ones are continuous elastic bodies, and the two lower ones are discontinuous elastic bodies.

[0086] As shown in Figure 8(B), four fourth elastic bodies 74a are arranged in the dorsal lower part 64, and four fourth elastic bodies 74b are arranged in the ventral upper part 32. All of the fourth elastic bodies 74 are discontinuous elastic bodies.

[0087] As shown in Figure 8(B), the five elastic bodies located on the upper dorsal portion 62 and the five elastic bodies located on the upper ventral portion 32 are designed to be positioned at the same location in the longitudinal direction X. Similarly, the two elastic bodies located on the middle dorsal portion 63 and the two upper elastic bodies located on the middle ventral portion 33 are designed to be positioned at the same location in the longitudinal direction X. Furthermore, the four elastic bodies located on the lower dorsal portion 64 and the four elastic bodies located on the lower ventral portion 34 are designed to be positioned at the same location in the longitudinal direction X, and the contraction stress is equal on both the dorsal and ventral sides in the area where the lower dorsal portion 64 and the lower ventral portion 34 are connected in a ring shape.

[0088] As shown in Figure 8(B), each elastic body located on the dorsal main body 61 may be positioned substantially the same in the longitudinal direction X as each elastic body located on the ventral body 3. "Substantially the same position" means that any design misalignment that may occur during diaper manufacturing is within 3 mm. Figure 8(B) shows a state in which no such manufacturing misalignment occurs.

[0089] [Method for measuring the elongation rate of an elastic material] Diaper 1 is separated at the side seal 8 and unfolded, then stretched. Two marks are made on each elastic body using an oil-based pen, spaced apart La in the stretching direction, in the area not including the side seal 8. Next, each elastic body is peeled off diaper 1, and the length Lb between the two marks in the natural state (contracted state) of each elastic body is measured. This measurement is performed three times for each elastic body, and the elongation rate is determined by the arithmetic mean of the values ​​calculated using the formula "La / Lb". The spacing La can be, for example, 100 mm, but if the stretchable range is less than 100 mm, the spacing La should be as wide as possible.

[0090] 《Average elongation rate of the elastic body arranged in the dorsal extension and the first region》 In the diaper 1 of this embodiment, the average elongation rate of the elastic body arranged in the dorsal extension portion 60 is higher than the average elongation rate of the elastic body arranged in the first region A. The method for calculating the average elongation rate will be described later. If one elastic body is arranged in the dorsal extension portion 60, the elongation rate of that one elastic body is taken as the average elongation rate of the elastic bodies arranged in the dorsal extension portion 60, and the same applies to the first region A.

[0091] In this way, by adjusting the average elongation rate of the elastic material, a diaper 1 having a first to third configuration that feels good against the skin can be easily obtained. In other words, by making the average elongation rate of the elastic body arranged in the dorsal extension 60 higher than the average elongation rate of the elastic body arranged in the first region A, the dorsal extension 60 will have a higher contraction stress in the lateral direction Y (the method for measuring contraction stress will be described later) than the first region A, and the diaper 1 can be easily adjusted to have the first to third configurations described above.

[0092] In order to achieve a suitable fit for diaper 1 and to have the first to third configurations, the average elongation rate of the elastic body arranged in the dorsal extension portion 60 is preferably 1.5 times or more and 5.0 times or less, more preferably 2.0 times or more and 4.0 times or less, and the average elongation rate of the elastic body arranged in the first region A is preferably 1.2 times or more and 4.0 times or less, more preferably 1.5 times or more and 3.5 times or less.

[0093] Specifically, in the diaper 1 of this embodiment, the three first elastic bodies 71a arranged in the dorsal extension portion 60 are each elastic bodies with an elongation ratio of 3.2 times, and the average elongation ratio of the elastic bodies arranged in the dorsal extension portion 60 is 3.2 times. Three elastic bodies are arranged in the first region A. From top to bottom, one first elastic body 71b and two second elastic bodies 72a are arranged in that order. The first elastic body 71b is an elastic body with an elongation ratio of 3.2 times. The second elastic bodies 72a are elastic bodies with an elongation ratio of 2.8 times. The average elongation ratio of the elastic bodies arranged in the first region A is approximately 2.9 times.

[0094] Furthermore, the dorsal extension portion 60 has a higher contraction stress in the lateral direction Y than the first region A. The shrinkage stress of the dorsal extension portion 60 is preferably 20 cN / 10 mm or more and 65 cN / 10 mm or less, and more preferably 25 cN / 10 mm or more and 60 cN / 10 mm or less. The shrinkage stress in the first region A is preferably 10 cN / 10 mm or more and 60 cN / 10 mm or less, and more preferably 15 cN / 10 mm or more and 55 cN / 10 mm or less.

[0095] [Method for measuring contraction stress] The contraction stress in each part is measured as the contraction stress in the Y direction per unit length, as follows:

[0096] (Measurement sample) Peel off the side seal of the diaper, stretch and unfold it as shown in Figure 3 to spread it flat, and cut out the areas of the ventral portion 3 and the dorsal portion 6, respectively, along a straight line parallel to the transverse direction of the diaper, to obtain strips or bands of each portion that extend across the entire transverse width between the side edges 54 of the ventral portion 3 and between the side edges 55 of the dorsal portion 6. When cutting out, cut the entire diaper, including the absorbent body 4, not just the ventral portion 3 and the dorsal portion 6, and remove the absorbent material 40. Alternatively, the ventral portion 3 and the dorsal portion 6 may be cut into their respective parts after removing the absorbent material 40. If an elastic body exists at the boundary between adjacent parts, the elastic body at the boundary should be placed in the upper part (waist side part), and the diaper should be cut in the part other than the adjacent elastic body. Record the length (in mm) of each cut sample in the vertical (X) and horizontal (Y) directions.

[0097] (Measurement of contraction stress in the Y direction) The sample is clamped at both ends in the chuck of a tensile testing machine (SHIMADZU "Autograph AG-X"), and stretched at a speed of 300 mm / min. The length between the side seals of the ventral and dorsal sides, measured by the inner dimensions of the ventral and dorsal sides, is set to 100 (e.g., 350 mm). The sample is stretched to a length equivalent to 80 (e.g., 280 mm), and then contracted to a length equivalent to 71 (e.g., 250 mm). The tensile load (cN) at this point is measured. This measured tensile load (cN) is converted to a tensile load (cN) per unit length (10 mm). The value obtained by dividing this converted tensile load (cN) per unit length (10 mm) by the length of the sample in the X direction is defined as the contraction stress P in the Y direction. The reason for defining the return force at a length equivalent to 71 when the inner dimensions of the ventral and dorsal parts are set to 100 is that the waist circumference of infants, who are the primary target of wearing the diaper 1 of this embodiment, is approximately 71% of the inner dimensions of the diaper. The waist circumference referred to here is the average value of the waist circumference measured in standing and sitting positions, taking into account the change in waist circumference when the posture of the infant changes. Each of the pair of side seals 8 (or side reinforcement parts 105) has an inner edge (inner side seal side edge 8d or inner side reinforcement part side edge 105d) located on the inside in the lateral Y direction, and the above "inner dimensions" refers to the distance between the pair of inner edges. Furthermore, the above "inner dimensions" refers to the inner dimensions when the sheet (thermoplastic sheet 50) constituting the outer body 5 is not contracted by the elastic body, in other words, when only the ventral and dorsal parts are stretched without the elastic body.

[0098] [Method for measuring average growth rate] Diaper 1 is separated at the side seal 8 and unfolded, then extended. For each elastic body located in each section (dorsal extension 60, first region A), two marks are made on the elastic body using an oil-based pen, spaced apart La in the direction of extension of the elastic body, in the area not including the side seal 8. Next, each elastic body is peeled off diaper 1, and the length Lb between the two marks on each elastic body in its natural state (contracted state) is measured. This measurement is performed three times for each elastic body, and the elongation rate is determined by the arithmetic mean of the values ​​calculated using the formula "La / Lb". The spacing La can be, for example, 100 mm, but if the stretchable range is less than 100 mm, the spacing La should be made as wide as possible. Then, for each part, the average value of the elongation rates obtained by the measurement method described above for each of the multiple elastic bodies placed in that part is calculated, and this is taken as the average elongation rate of the elastic bodies placed in each part (dorsal extension 60, first region A). Typically, multiple elastic bodies are placed in each part, but if only one elastic body is placed in one part, the elongation rate of that elastic body is taken as the average elongation rate. Furthermore, when defining the range of the dorsal extension portion 60 and the first region A portion from the diaper in its extended state, if an elastic body exists at the boundary between adjacent portions, the elastic body at the boundary shall be positioned in the upper portion (waist portion). For example, if an elastic body exists at the boundary between the first region A portion and a portion located below and adjacent to the first region A portion, the elastic body shall be positioned in the first region A.

[0099] 《Average fineness of the elastic material placed in the dorsal extension and the first region》 In the diaper 1 of this embodiment, it is preferable that the average fineness of the multiple elastic bodies arranged in the dorsal extension is higher than the average fineness of the multiple elastic bodies arranged in the first region A. The method for calculating the average fineness will be described later. If one elastic body is arranged in the dorsal extension 60, the fineness of that one elastic body is taken as the average fineness of the elastic bodies arranged in the dorsal extension 60, and the same applies to the first region A.

[0100] This configuration allows the dorsal extension portion 60 to fit more snugly against the wearer's back, reducing the likelihood of poor fit due to undesirable gapping and resulting in a diaper 1 that feels comfortable against the skin.

[0101] From the viewpoint of good skin contact and appropriate fit of diaper 1, the average fineness of the elastic material in the dorsal extension portion 60 is preferably 250 dtex or more and 800 dtex or less, more preferably 300 dtex or more and 750 dtex or less, and the average fineness of the elastic material in the first region A is preferably 200 dtex or more and 750 dtex or less, more preferably 250 dtex or more and 650 dtex or less.

[0102] Specifically, in the diaper 1 of this embodiment, the three first elastic bodies 71a arranged in the dorsal extension 60 are elastic bodies with a fineness of 470 dtex, and the average fineness of the elastic bodies arranged in the dorsal extension 60 is 470 dtex. In the first region A, one first elastic body 71b and two second elastic bodies 72a are arranged. The first elastic body 71b has a fineness of 470 dtex. The second elastic bodies 72a have a fineness of 310 dtex. The average fineness of the elastic bodies arranged in the first region A is approximately 363 dtex.

[0103] [Method for calculating average fiber density] Diaper 1 is separated at the side seal 8 and unfolded. For each section (dorsal extension 60, first region A), the average of the fineness of the multiple elastic bodies placed in that section is calculated to obtain the average fineness of the elastic bodies. Typically, multiple elastic bodies are placed in each section, but if only one elastic body is placed in a single section, the fineness of that elastic body is taken as the average fineness.

[0104] In this embodiment of diaper 1, an example was given in which both the average elongation rate and average fineness of the elastic bodies in the dorsal extension portion 60 and the first region A are adjusted, but the embodiment is not limited to this. For example, the average fineness of the elastic body arranged in the dorsal extension portion 60 and the average fineness of the elastic body arranged in the first region A may be made the same, and the average elongation rate of the elastic body arranged in the dorsal extension portion 60 may be made higher than the average elongation rate of the elastic body arranged in the first region A. Furthermore, from the viewpoint of making it easier to adjust to the first to third configurations, it is preferable to adjust both the average elongation rate and the average fineness.

[0105] Furthermore, in addition to adjusting the average elongation rate and / or average fineness of the elastic body, the first to third configurations may also be achieved by adjusting the coating area of ​​the hot-melt adhesive used to fix the elastic body to the exterior body and / or by adjusting the thickness and basis weight of the sheets constituting the exterior body. This makes it easier to adjust the configurations to the first to third configurations.

[0106] 《Elastic body placed in the first region》 In the diaper 1 of this embodiment, three elastic bodies are arranged in the first region A, with one first elastic body 71b and two second elastic bodies 72a arranged in order from top to bottom. The first elastic body 71b is an elastic body with a fineness of 470 dtex. The second elastic bodies 72a are elastic bodies with a fineness of 310 dtex.

[0107] Thus, the multiple elastic bodies placed in the first region A may be arranged such that their fineness increases as they approach the dorsal waist end 102. This configuration makes it easier for the upper end 8a of the side seal 8 to face the back (rear side in the front-to-back direction) when worn, and as a result, the side reinforcement portion 105 connected to the side seal 8 also tends to be positioned more towards the back overall. This makes it less likely for the highly rigid side reinforcement portion 105 to come into contact with the side of the wearer's waist, resulting in a diaper 1 that is more comfortable against the skin.

[0108] Furthermore, in the diaper 1 of this embodiment, a first elastic body 71a having the same fineness and elongation ratio as the first elastic body 71b positioned at the very top of the first region A is arranged in the dorsal extension portion 60 adjacent to the first region A and located just above the first region A. As a result, two types of elastic bodies (first elastic body 71 and second elastic body 72) with different fineness and elongation rates are arranged from the dorsal extension portion 60 to the first region A. In other words, in the region comprising the dorsal extension portion 60 and the first region A (for convenience, referred to as the "second region"), the elastic body with relatively high fineness and elongation rate (first elastic body 71) is arranged in the upper part of the second region, and the elastic body with relatively low fineness and elongation rate (second elastic body 72) is arranged in the lower part of the second region. In the second region, the area near the boundary between the area where the first elastic body 71 is arranged and the area where the second elastic body 72 is arranged tends to bend easily due to the difference in fineness and elongation rates of the elastic bodies arranged in the two regions. However, in the diaper 1 of this embodiment, this area near the boundary is not at the boundary portion 103 but is located below the boundary portion 103, so the dorsal extension portion 60 is less likely to bend and less likely to curl up compared to when it is at the boundary portion 103. Therefore, the diaper 1 can be worn so that the dorsal extension portion 60 is in the correct position, and the function of preventing leakage of excrement by providing the dorsal extension portion 60 can be effectively realized.

[0109] Furthermore, due to misalignment during manufacturing, the first elastic body 71b located at the top of the first region A may be positioned on the dorsal extension 60, and even in such a case, the first, second, and third configurations described above can still be used. From the viewpoint of effectively suppressing the curling of the dorsal extension portion 60, it is preferable that, as in the diaper 1 of this embodiment, the area near the boundary between the first elastic body 71 and the second elastic body 72 on the dorsal side is not at the boundary portion 103, but is located below the boundary portion 103.

[0110] 《Position of the side seal when worn》 As shown in Figure 5, it is preferable that the diaper 1 in the worn state has a configuration in which the third intersection angle θ3, which is the intersection angle between the fourth virtual line L4 and the third virtual line L3, is 5 degrees or more and 60 degrees or less (referred to as the "fourth configuration"). That is, as shown in Figure 5, it is preferable that the portion of the side seal 8 above the fifth point P5 and the side reinforcement portion 105 connected thereto are positioned such that their upper side is closer to the back than their lower side, and that they are generally oblique to the vertical direction X.

[0111] By adopting the fourth configuration, when worn, the side reinforcement portion 105 is positioned further towards the back, making it less likely for the side reinforcement portion 105 to come into contact with the wearer's waist area, resulting in a better feel against the skin.

[0112] The fourth configuration can be achieved by adjusting the lateral Y-stress of the dorsal middle section 63 and the ventral middle section 33 (the method for measuring the lateral Y-stress will be described later). The lateral Y-stress in each section can be adjusted by varying the fineness and / or elongation rate of the elastic bodies placed in each section, the number of elastic bodies, the spacing between the elastic bodies, etc. In the diaper 1 of this embodiment, an elastic body having the fineness and elongation rate given as an example in the "Specific Examples of Elastic Bodies" described above is used, and the number of elastic bodies placed in the dorsal middle section 63 and the ventral middle section 33 is varied so that the lateral Y-stress of the dorsal middle section 63 is smaller than that of the ventral middle section 33, thereby achieving the fourth configuration. In the diaper 1 of this embodiment, in addition to varying the fineness and elongation rate of the elastic bodies, adjusting the number of elastic bodies makes it possible to adjust the lateral Y-stress more simply, and it is possible to adjust more easily to achieve the fourth configuration.

[0113] Specifically, as shown in Figure 8(B), in the diaper 1 of this embodiment, two third elastic bodies 73b are arranged in the dorsal middle section 63, and a total of five elastic bodies, one second elastic body 72c and four third elastic bodies 73c, are arranged in the ventral middle section 33. The third elastic bodies 73b and 73c have the same fineness and elongation rate. The second elastic body 72c has a lower fineness and a higher elongation rate than the third elastic bodies 73b and 73c. ​​In addition, in the diaper 1 of this embodiment, the ventral middle section 33 has more elastic bodies (third elastic bodies) with the same fineness and elongation rate than the dorsal middle section 63, and the contraction stress in the lateral direction Y is smaller in the dorsal middle section 63 than in the ventral middle section 33. By setting the relationship of contractile stress between the dorsal intermediate portion 63 and the ventral intermediate portion 33 to this relationship, when worn, as shown in Figures 2 and 5, the dorsal intermediate portion 63 is pulled toward the ventral side by the contractile force of the ventral intermediate portion 33, resulting in the fourth configuration.

[0114] Furthermore, from the viewpoint of more reliably achieving the fourth configuration, in addition to the relationship of contractile stress between the dorsal middle section 63 and the ventral middle section 33, it is more preferable that the dorsal upper section 62 has a higher contractile stress in the lateral direction Y than the ventral upper section 32. In the diaper 1 of this embodiment, the dorsal upper section 62 has a higher contractile stress in the lateral direction Y than the ventral upper section 32, using an elastic body having the fineness and elongation ratio given as an example in the "Specific Examples of Elastic Bodies" described above. Specifically, one first elastic body 71b (fineness 470 dtex, elongation ratio 3.2 times), two second elastic bodies 72a (fineness 310 dtex, elongation ratio 2.8 times), and two third elastic bodies 73a (fineness 780 dtex, elongation ratio 2.7 times) are arranged in the dorsal upper section 62, and five second elastic bodies 72b (fineness 310 dtex, elongation ratio 2.8 times) are arranged in the ventral upper section 32.

[0115] This configuration allows for adjustment of the contraction stress in each part, making it easier to position the portion of the side seal 8 above the fifth point P5 in the worn state so that the upper part is closer to the dorsal side and the lower part is closer to the ventral side, with respect to the vertical direction X. As a result, the side reinforcement portion 105 connected to the side seal 8 naturally tends to tilt more towards the dorsal side, making it possible to more reliably achieve the fourth configuration.

[0116] In this way, by adjusting the contraction stress in each part of the dorsal and ventral sections to achieve a good feel against the skin, the side reinforcement and even the side seal can be easily designed to have any desired inclination with respect to the longitudinal X direction.

[0117] 《Form of the dorsal extension when worn》 As shown in Figures 2 and 5, when the diaper 1 is worn, the dorsal extension portion 60 has a width in the lateral direction Y that continuously narrows (gradually narrows) towards the dorsal waist end portion 102. In this way, by configuring the width of the dorsal extension portion 60 to gradually narrow (continuously narrow) along the vertical direction X without abruptly changing, there are no extreme corners near the side reinforcement portion 105, resulting in a comfortable feel against the skin when worn.

[0118] Examples of laminated structures for exterior bodies As shown in Figure 9, the exterior body 5 preferably includes a plurality of thermoplastic sheets 50, for example, an outer layer sheet 51 and an inner layer sheet 52. The outer layer sheet 51 is positioned on the non-skin side of the inner layer sheet 52 and forms the non-skin facing surface of the exterior body 5. First to fourth elastic bodies 71 to 74 are positioned between the inner layer sheet 52 and the outer layer sheet 51.

[0119] In this embodiment, the diaper 1 has a folded structure in which at least a portion of the outer casing 5 is folded back from the waist opening end Wa towards the skin-facing side. In the dorsal portion 6 of the diaper 1 shown in Figure 9, the laminated outer layer sheet 51 and inner layer sheet 52 are folded back towards the skin from the dorsal waist end 102. In the dorsal portion 6, where the outer casing 5 is folded back and two layers of outer casing 5 are laminated, the two layers of outer casing 5 are bonded together with adhesive 19. In the ventral portion 3 of diaper 1, the laminated outer layer sheet 51 and inner layer sheet 52 are folded back from the ventral waist end 101 towards the skin-facing side. In the ventral portion 3, where the outer casing 5 is folded back and two layers of outer casing 5 are laminated, the two layers of outer casing 5 are bonded together with adhesive 19.

[0120] [Details of the dorsal layered structure] As shown in Figure 2, it is preferable that the diaper 1 has vertical pleats 67 that extend continuously in the vertical direction on the dorsal extension portion 60 and the upper dorsal portion 62. In the diaper 1 of this embodiment, vertical pleats are provided on both the dorsal portion 6 and the ventral portion 3. The provision of vertical pleats increases cushioning and makes the diaper feel better against the skin. In addition, the provision of vertical pleats 67 provides excellent breathability and a comfortable wearing experience. The vertical pleats 67 may be provided on at least one surface of the laminate of the outer layer sheet 51 and the inner layer sheet 52 that constitute the outer casing 5, and in this embodiment, an example is given in which vertical pleats are formed on both surfaces.

[0121] The vertical folds 67 can be formed, for example, by partially joining the outer layer sheet 51 and the inner layer sheet 52, which are multiple thermoplastic sheets 50 that constitute the outer casing 5, and will be explained with reference to Figure 11.

[0122] As shown in Figure 11, the outer covering 5 in the ventral portion 3 and dorsal portion 6 is joined by a joint 58 consisting of an outer sheet 51 and an inner sheet 52, which are partially provided as heat seals. The joint 58 is intermittently arranged in both the longitudinal direction X and the transverse direction Y. Multiple elastic bodies (elastic bodies 71-73 in Figure 11) are arranged so as not to pass through the joint 58. Each of the multiple elastic bodies is joined to the outer sheet 51 and the inner sheet 52 only at the ends in the longitudinal direction where they are located at or near the side reinforcement portion 105, or only at or near the side seal 8, and is not joined to the outer sheet 51 and the inner sheet 52 in the central part in the longitudinal direction. In the outer covering 5 with this configuration, the outer sheet 51 and the inner sheet 52 each form multiple longitudinal folds 67 that extend continuously in the longitudinal direction X across the multiple elastic bodies in the natural state and when the diaper 1 is worn. The vertical pleats 67 are formed on both sides of the laminate of the outer layer sheet 51 and the inner layer sheet 52. For example, in a diaper 1 having an abdominal waist end 101 and a dorsal waist end 102 formed by folding the outer casing 5 towards the skin-facing side, as shown in Figure 9, vertical pleats 67 are provided on both the skin-facing and non-skin-facing sides of the dorsal extension 60, the dorsal upper part 62, and the abdominal upper part 32. The above-mentioned heat seals include heat seals and ultrasonic seals.

[0123] The dorsal extension portion 60 of diaper 1 is positioned in contact with the wearer's skin near the waist when worn. In diaper 1 of this embodiment, the first elastic body 71a in the dorsal extension portion 60 is joined to both sheets (outer layer sheet 51 and inner layer sheet 52) ​​only at both ends in the longitudinal direction, and the rest of the length in the center is not joined to both sheets. Therefore, in diaper 1, compared to diapers where the elastic body is fixed to the sheet over its entire surface, the contraction of the elastic body is less likely to be hindered by the sheet when it contracts. As a result, when worn, the side reinforcement portion 105 tends to fold towards the back, making it less likely to come into contact with the wearer's waist, resulting in a diaper 1 that is comfortable against the skin. Furthermore, by joining and fixing the elastic body to the sheet only at both ends in the longitudinal direction, and leaving the rest unfixed to the sheet, a high elongation rate can be easily obtained, simplifying the design.

[0124] In addition, in the dorsal extension portion 60 of the diaper 1 of this embodiment, the joint portion 58 is formed by heat sealing, so in the dorsal extension portion 60, except for the portion where both ends of the first elastic body 71a are joined to the sheet, there is no adhesive between the outer sheet 51 and the inner sheet 52. In this way, the absence of adhesive between the outer sheet 51 and the inner sheet 52 in the dorsal extension portion 60 makes the dorsal extension portion 60 soft to the touch, resulting in a diaper 1 that is even more comfortable against the skin.

[0125] In the diaper 1 of this embodiment, the upper dorsal portion 62 and the upper ventral portion 32 that form the waist area are, like the dorsal extension portion 60, not fixed to both sheets in the longitudinal central portion of the elastic material, and there is no adhesive between the two sheets, resulting in a soft and comfortable feel against the skin.

[0126] In this embodiment, an example is given in which the joint portion 58 is formed by heat sealing, but the joint portion 58 may be formed by other joining means, for example, by hot melt adhesive. From the viewpoint of providing a better feel against the skin, it is more preferable to form the joint portion 58 by heat sealing, as in the diaper 1 of this embodiment.

[0127] In this embodiment of diaper 1, an example was given in which the elastic bodies are not fixed to the outer layer sheet 51 and the inner layer sheet 52 except at both ends of each elastic body. However, each elastic body may be intermittently fixed to the outer layer sheet and the inner layer sheet in its longitudinal direction, and such a configuration may form vertical folds.

[0128] Examples of contraction stress in various parts Examples of lateral Y-direction shrinkage stress in each part, measured using the shrinkage stress measurement method described above, are given below, but the values ​​listed here are not limited to those given. The shrinkage stress of the dorsal extension portion 60 is preferably 20 cN / 10 mm or more and 65 cN / 10 mm or less, and more preferably 25 cN / 10 mm or more and 60 cN / 10 mm or less. The shrinkage stress of the dorsal upper portion 62 is preferably 5 cN / 10 mm or more and 50 cN / 10 mm or less, and more preferably 10 cN / 10 mm or more and 45 cN / 10 mm or less. The shrinkage stress in the dorsal intermediate portion 63 is preferably 0 cN / 10 mm or more and 40 cN / 10 mm or less, and more preferably 0 cN / 10 mm or more and 30 cN / 10 mm or less. The shrinkage stress of the lower dorsal portion 64 is preferably 5 cN / 10 mm or more and 50 cN / 10 mm or less, and more preferably 10 cN / 10 mm or more and 45 cN / 10 mm or less. The contractile stress of the ventral upper portion 32 is preferably 5 cN / 10 mm or more and 50 cN / 10 mm or less, and more preferably 10 cN / 10 mm or more and 45 cN / 10 mm or less. The contractile stress in the ventral middle portion 33 is preferably 8 cN / 10 mm or more and 55 cN / 10 mm or less, and more preferably 13 cN / 10 mm or more and 40 cN / 10 mm or less. The contractile stress of the ventral lower portion 34 is preferably 5 cN / 10 mm or more and 50 cN / 10 mm or less, and more preferably 10 cN / 10 mm or more and 45 cN / 10 mm or less.

[0129] <Other Embodiments> Although embodiments of the present invention have been described above, the present invention is not limited to the embodiments described above, and various modifications can be made without departing from the spirit of the present invention.

[0130] The absorbent pant-type article according to the present invention does not have to be a disposable diaper for infants; for example, it may be a disposable diaper for adults or children. Furthermore, the absorbent pant-type article according to the present invention does not have to be a disposable diaper, as long as it is an absorbent article of the type worn on the lower body. Examples of such absorbent pant-type articles include sanitary napkins in pant form.

[0131] The following describes diapers of other embodiments, using the second to fourth embodiments as examples.

[0132] The placement of the elastic body is not limited to the placement of the elastic body in diaper 1 of the first embodiment, but may be in other positions, which will be described below as the second and third embodiments. Diaper 1A of the second embodiment and diaper 1B of the third embodiment are diapers that have a dorsal extension portion, similar to the first embodiment, and differ mainly in the placement of the elastic body compared to diaper 1 of the first embodiment. Diapers 1A and 1B have the same first to third configurations as diaper 1 of the first embodiment, are comfortable against the skin, and the excrement prevention function by the dorsal extension portion 60 can be effectively expressed.

[0133] <Second Embodiment> As shown in Figures 4 and 14, the diaper 1A of the second embodiment satisfies the first to third configurations described above. In diaper 1A, as with diaper 1, the first to third configurations can be realized by appropriately adjusting the fineness, elongation rate, and spacing of the elastic material arranged in the outer casing 5.

[0134] In the first embodiment of the diaper 1, the ventral middle portion 33 and the dorsal middle portion 63 located near the ilium have an elastic body-free region in the dorsal middle portion 63 where there is no elastic body in the same position in the longitudinal direction X as the elastic body located in the ventral middle portion 33. With this configuration, when the diaper 1 is worn, as shown in Figures 2 and 5, the side seal 8 has a shape that is generally inclined with respect to the vertical direction X, from top to bottom and from the dorsal side to the ventral side. However, at the dorsal middle section 63 and the ventral middle section 33, the dorsal middle section 63 is pulled towards the ventral side by the ventral middle section 33, so the side seal 8 has a roughly S-shape.

[0135] In contrast, as shown in Figure 12, in the diaper 1A of this embodiment (second embodiment), the multiple (four in this case) third elastic bodies 73b arranged in the ventral middle section 33 and the multiple (four in this case) third elastic bodies 73a arranged in the dorsal middle section 63 may be in the same position in the longitudinal direction X. As a result, in the diaper 1A when worn, as shown in Figure 14, the side seal 8 has a substantially straight shape that slopes with respect to the vertical direction X, from top to bottom and from the dorsal side to the ventral side. Thus, in the diaper when worn, the side seal 8 may have a substantially straight shape that slopes with respect to the vertical direction X. In this way, the diaper 1A, when worn, has a nearly straight, inclined shape for the side seal 8, resulting in a neat appearance. Furthermore, by arranging the same number of elastic bodies with the same fineness and elongation rate in the ventral middle section 33 and the dorsal middle section 63, the stress near the iliac crest on both the ventral and dorsal sides increases when worn. This prevents the diaper from slipping down on the ventral and dorsal sides even when the child moves around vigorously after wearing it, further effectively suppressing leakage of loose stool from the dorsal side. The same applies to the diaper 1B of the third embodiment described later.

[0136] In the first embodiment of diaper 1, the first crossing angle θ1 in the natural length state was 10 degrees, and the second crossing angle θ2 in the worn state was 40 degrees. In contrast, in the diaper 1A of this embodiment, the first crossing angle θ1 in the natural length state was 10 degrees, and the second crossing angle θ2 in the worn state was 30 degrees. In the third embodiment of diaper 1B, described later, the first and second crossing angles were approximately the same as those of diaper 1A. Note that these values ​​are examples and are not limiting.

[0137] As shown in Figure 12, in the dorsal portion 6 of diaper 1A, three first elastic bodies 71a are arranged in the dorsal extension portion 60. In the upper dorsal portion 62, a total of four elastic bodies are arranged: one first elastic body 71b, two second elastic bodies 72a, and one second elastic body 72b. In the middle dorsal portion 63, four third elastic bodies 73a are arranged. In the lower dorsal portion 64, four fourth elastic bodies 74a are arranged. The upper dorsal portion 62 includes a first region A that has the same length in the vertical direction X as the dorsal extension portion 60, and the first and second elastic bodies arranged in this first region A are denoted by reference numerals 71b and 72a, respectively. In the ventral portion 3 of diaper 1A, a total of five second elastic bodies are arranged in the upper ventral portion 32: one second elastic body 72c and four second elastic bodies 72d. Four third elastic bodies 73b are arranged in the middle ventral portion 33. Four fourth elastic bodies 74b are arranged in the lower ventral portion 34. In the multiple elastic bodies arranged in the ventral portion 3 and the dorsal portion 6, the two lower elastic bodies out of the four elastic bodies arranged in the dorsal intermediate portion 63, the two lower elastic bodies out of the four elastic bodies arranged in the ventral intermediate portion 33, the four elastic bodies arranged in the dorsal lower portion 64, and the four elastic bodies arranged in the ventral lower portion 34 are discontinuous elastic bodies, while the other elastic bodies are continuous elastic bodies. Furthermore, if an elastic body exists at the boundary between adjacent parts, that elastic body is considered to be located in the upper part, and the number of elastic bodies in each part is counted accordingly. The same applies to the third embodiment described later.

[0138] As shown in Figure 12, the upper ventral portion 32 of diaper 1A is constructed by folding over the outer casing 5, resulting in two layers of the outer casing 5. In diaper 1A, four second elastic bodies 72d are placed on the outer casing 5 located on the non-skin side of the two-layered outer casing, and one second elastic body 72c is placed on the outer casing 5 located on the skin side (folded portion). The "folded portion" refers to the part of the outer casing 5 that is folded inward. In the example shown in Figure 12, the second elastic body 72c is placed in the upper region when the upper ventral portion 32 is divided into two equal parts in the vertical direction X.

[0139] Thus, the elastic body may be placed in the folded portion of the ventral part 3. This configuration allows for different contraction stresses in the upper and lower regions when the ventral upper part 32 is bisected along the longitudinal direction X, making it easier to adjust the contraction stress distribution in the outer casing 5, and consequently easier to adjust to the first to third configurations described above. In the example of diaper 1A shown in Figure 12, the upper ventral portion 32 has two elastic bodies (72c, 72d) arranged in the thickness direction Z in the upper region of the ventral portion 32, and one elastic body (72d) arranged in the thickness direction Z in the lower region of the ventral portion 32. As a result, the contraction stress in the lateral direction Y is higher in the upper region of the ventral portion 32 than in the lower region. Furthermore, by placing an elastic material in the folded portion of the ventral part 3, discomfort during wear can be reduced. Specifically, since the contraction stress near the ventral waist end 101 can be controlled not only by the fineness and elongation rate of the elastic material but also by the number of fibers, by placing an elastic material in the folded portion of the ventral part 3 and increasing the number of elastic fibers, the contraction stress near the ventral waist end 101 can be increased more easily. This makes it easier to move the position of the first point P1 (fourth point P4) in Figure 14, which corresponds to the position when worn, towards the ventral side, and makes it easier to adjust the second intersection angle θ2, which is the intersection angle of the second virtual line L2 and the third virtual line L3, to be larger, and also makes fine angle adjustments easier. As a result, discomfort during wear can be further reduced.

[0140] Examples of fineness and elongation ratio of elastic materials are given below. However, the fineness and elongation ratio are not limited to those listed here. Each elastic material extends along the transverse direction Y and is intermittently arranged along the longitudinal direction X. The first elastic body 71a and the first elastic body 71b have the same fineness and elongation ratio, differing only in the location where they are arranged; the fineness is 470 dtex and the elongation ratio is 3.2 times. The second elastic bodies 72a, 72b, 72c, and 72d differ only in their placement and location, but have the same fineness and elongation ratio, with a fineness of 310 dtex and an elongation ratio of 2.8 times. The third elastic body 73a and the third elastic body 73b have the same fineness and elongation ratio, differing only in the location where they are placed; the fineness is 780 dtex and the elongation ratio is 2.7 times. The fourth elastic body 74a and the fourth elastic body 74b have the same fineness and elongation ratio, differing only in their placement; the fineness is 620 dtex and the elongation ratio is 2.5 times.

[0141] As shown in Figure 12, in the dorsal portion 6, four first elastic bodies (three first elastic bodies 71a and one first elastic body 71b), three second elastic bodies (two second elastic bodies 72a and one second elastic body 72b), and four third elastic bodies 73a are intermittently arranged at equal intervals in the vertical direction X (for example, with a pitch of 5.5 mm). In the dorsal portion 6, the spacing between the two upper fourth elastic bodies 74a and the spacing between the two lower fourth elastic bodies 74a is the same, and for example, their pitch is 5.5 mm. In the elastic bodies positioned outside the folded portion of the ventral portion 3, the four second elastic bodies 72d and the four third elastic bodies 73b are intermittently arranged at equal intervals (for example, a pitch of 5.5 mm) in the longitudinal direction X. In the ventral portion 3, the spacing between the two upper fourth elastic bodies 74b and the spacing between the two lower fourth elastic bodies 74b are the same, and their pitch is, for example, 5.5 mm.

[0142] Furthermore, as shown in diaper 1A in Figure 12, the dorsal end 106 and the ventral end 107 of the absorbent body 4 may be in the same position in the longitudinal direction X. This configuration allows the absorbent body 4 on the ventral side to extend to the vicinity of the ventral waist end 101, increasing the rigidity of the ventral portion 3 and making it less likely for the diaper to roll up near the waist end 101. This prevents leakage due to rolling up and also suppresses discomfort caused by rolling up. The same applies to the diaper 1B of the third embodiment described later.

[0143] <Third Embodiment> As shown in Figures 4 and 14, the diaper 1B of the third embodiment satisfies the first to third configurations described above. In diaper 1B, as with diaper 1, the first to third configurations can be realized by appropriately adjusting the fineness, elongation rate, and spacing of the elastic material arranged in the outer casing 5.

[0144] In the third embodiment, diaper 1B, similar to diaper 1A in the second embodiment, has multiple (in this case, four) third elastic bodies 73b arranged in the ventral middle section 33 and multiple (in this case, four) third elastic bodies 73a arranged in the dorsal middle section 63, all located in the same position in the longitudinal direction X. With this configuration, diaper 1B, like diaper 1A, has a substantially straight shape that slopes with respect to the vertical direction X, from top to bottom, from the dorsal side to the ventral side, as shown in Figure 14.

[0145] As shown in Figure 13, in the dorsal portion 6 of diaper 1B, two first elastic bodies 71a and one first elastic body 71c are arranged in the dorsal extension portion 60. In the upper dorsal portion 62, a total of four elastic bodies are arranged: one first elastic body 71b, one second elastic body 72a, and two second elastic bodies 72b. In the middle dorsal portion 63, four third elastic bodies 73a are arranged. In the lower dorsal portion 64, four fourth elastic bodies 74a are arranged. The upper dorsal portion 62 includes a first region A that has the same length in the vertical direction X as the dorsal extension portion 60, and the first elastic bodies arranged in this first region A are denoted by reference numeral 71b, and the second elastic bodies are denoted by reference numeral 72a. In the ventral portion 3 of diaper 1B, a total of five second elastic bodies are arranged in the upper ventral portion 32: one second elastic body 72c and four second elastic bodies 72d. Four third elastic bodies 73b are arranged in the middle ventral portion 33. Four fourth elastic bodies 74b are arranged in the lower ventral portion 34. In the multiple elastic bodies arranged in the ventral portion 3 and the dorsal portion 6, the two lower elastic bodies out of the four elastic bodies arranged in the dorsal intermediate portion 63, the two lower elastic bodies out of the four elastic bodies arranged in the ventral intermediate portion 33, the four elastic bodies arranged in the dorsal lower portion 64, and the four elastic bodies arranged in the ventral lower portion 34 are discontinuous elastic bodies, while the other elastic bodies are continuous elastic bodies.

[0146] As shown in Figure 13, the upper ventral portion 32 of diaper 1B is folded over to form two layers of outer body 5. In diaper 1B, four second elastic bodies 72d are arranged on the outer body 5 located on the non-skin side of these two layers, and one second elastic body 72c is arranged on the outer body 5 (folded portion) located on the skin side. The dorsal extension portion 60 of diaper 1B is folded over to form two layers of outer body 5. In diaper 1B, two first elastic bodies 71a are arranged on the outer body 5 located on the non-skin side of these two layers, and one first elastic body 71c is arranged on the outer body 5 (folded portion) located on the skin side. In the example shown in Figure 13, the second elastic body 72c is positioned in the upper region when the ventral upper portion 32 is bisected in the longitudinal direction X, and the first elastic body 71c is positioned in the upper region when the dorsal extension portion 60 is bisected in the longitudinal direction X, in the folded portion of the dorsal extension portion 60.

[0147] Thus, the configuration may include elastic bodies in both the dorsal portion 6 and the ventral portion 3. This configuration allows for different shrinkage stresses in the upper and lower regions when the ventral upper portion 32 and the dorsal extension portion 60 are bisected in the longitudinal direction X, making it easier to adjust the shrinkage stress distribution in the outer casing 5, and consequently easier to adjust to the first to third configurations described above. In the example of diaper 1B shown in Figure 13, the upper ventral portion 32 has two elastic bodies (72c, 72d) arranged in the thickness direction Z in the upper region of the ventral portion 32, and one elastic body (72d) arranged in the thickness direction Z in the lower region of the ventral portion 32. As a result, the contraction stress in the lateral direction Y is higher in the upper region of the ventral portion 32 than in the lower region. Also, in diaper 1B, the upper region of the dorsal extension 60 has two elastic bodies (71a, 71c) arranged in the thickness direction Z, and one elastic body (71a) arranged in the thickness direction Z in the lower region of the dorsal extension 60. As a result, the dorsal portion 6 is configured so that the contraction stress decreases more gradually from the dorsal extension 60 to the first region A, making the dorsal extension 60 even less likely to curl up. Furthermore, by placing elastic bodies at the folded-over portions of both the ventral portion 3 and the dorsal portion 6, discomfort during wear can be further reduced. Specifically, since the contraction stress near the ventral waist end 101 can be controlled not only by the fineness and elongation rate of the elastic bodies but also by the number of bodies, by placing elastic bodies at the folded-over portion of the ventral portion 3 and increasing the number of elastic bodies, the contraction stress near the ventral waist end 101 can be more easily increased, making it easier to move the position of the first point P1 (fourth point P4) in Figure 14, which corresponds to the time of wear, towards the ventral side. Moreover, since the contraction stress near the dorsal waist end 102 can be controlled by the number of elastic bodies, similar to the ventral portion 3, by placing elastic bodies at the folded-over portion of the dorsal portion 6 and increasing the number of elastic bodies, the contraction stress near the dorsal waist end 102 can be more easily increased, making it easier to move the position of the third point P3 in Figure 14, which corresponds to the time of wear, towards the dorsal side. As a result, the second intersection angle θ2, which is the intersection angle of the second virtual line L2 and the third virtual line L3, can be more easily adjusted to be larger. This can further reduce discomfort when wearing the garment.

[0148] Examples of fineness and elongation ratio of elastic materials are given below. However, the fineness and elongation ratio are not limited to those listed here. Each elastic material extends along the transverse direction Y and is intermittently arranged along the longitudinal direction X. The first elastic bodies 71a, 71b, and 71c differ only in their placement and location, but have the same fineness and elongation ratio, with a fineness of 470 dtex and an elongation ratio of 3.2 times. The second elastic bodies 72a, 72b, 72c, and 72d differ only in their placement and location, but have the same fineness and elongation ratio, with a fineness of 310 dtex and an elongation ratio of 2.8 times. The third elastic body 73a and the third elastic body 73b have the same fineness and elongation ratio, differing only in the location where they are placed; the fineness is 780 dtex and the elongation ratio is 2.7 times. The fourth elastic body 74a and the fourth elastic body 74b have the same fineness and elongation ratio, differing only in their placement; the fineness is 620 dtex and the elongation ratio is 2.5 times.

[0149] As shown in Figure 13, in the elastic bodies arranged in a manner other than the folded portion of the back side 6, three first elastic bodies (two first elastic bodies 71a and one first elastic body 71b), three second elastic bodies (one second elastic body 72a and two second elastic bodies 72b), and four third elastic bodies 73a are intermittently arranged at equal intervals in the vertical direction X (for example, with a pitch of 5.5 mm). In the back side 6, the spacing between the two upper fourth elastic bodies 74a and the spacing between the two lower fourth elastic bodies 74a is the same, and for example, their pitch is 5.5 mm. In the elastic bodies positioned outside the folded portion of the ventral portion 3, the four second elastic bodies 72d and the four third elastic bodies 73b are intermittently arranged at equal intervals (for example, a pitch of 5.5 mm) in the longitudinal direction X. In the ventral portion 3, the spacing between the two upper fourth elastic bodies 74b and the spacing between the two lower fourth elastic bodies 74b are the same, and their pitch is, for example, 5.5 mm.

[0150] Furthermore, as shown in Figure 13, in diaper 1B, similar to diaper 1A, the dorsal end 106 and the ventral end 107 of the absorbent body 4 may be in the same position in the longitudinal direction X.

[0151] In the second embodiment of diaper 1A and the third embodiment of diaper 1B, similar to diaper 1, the average elongation rate of the elastic material arranged in the dorsal extension portion 60 is higher than the average elongation rate of the elastic material arranged in the first region A, and the average fineness of the elastic material arranged in the dorsal extension portion 60 is higher than the average fineness of the elastic material arranged in the first region. Diapers 1A and 1B, like diaper 1, have multiple elastic bodies positioned in the first region such that their fineness increases as they approach the dorsal waist end 102. Diapers 1A and 1B, like diaper 1, have a third crossing angle θ3 that is between 5 degrees and 60 degrees. Similar to diaper 1, diapers 1A and 1B, when worn, have a width in the lateral direction Y of the dorsal extension 60 that continuously narrows towards the dorsal waist end 102.

[0152] Diapers 1A and 1B, like diaper 1, may have vertical folds extending in the vertical direction X on the dorsal extension portion 60 and the upper dorsal portion 62 when worn. Diapers 1A and 1B may have the same configuration as diaper 1, with the dorsal extension 60 having a joint 58 where an outer layer sheet 51 and an inner layer sheet 52 with an elastic body sandwiched in between are partially joined, and the elastic body placed in the dorsal extension 60 may have both ends in the longitudinal direction joined to the outer layer sheet and the inner layer sheet, but the central part in the longitudinal direction is not joined to the outer layer sheet and the inner layer sheet. Furthermore, in diapers 1A and 1B, the joint portion 58 is formed by heat sealing, and in the dorsal extension portion 60, adhesive does not need to be present between the outer layer sheet 51 and the inner layer sheet 52.

[0153] <Fourth Embodiment> In the diapers 1, 1A, and 1B of the embodiments described above, the outer body 5 is shown as having a configuration in which the ventral part 3, the dorsal part 6, and the crotch area 9 are integrated, but it is not limited to this. For example, as in the pant-type diaper 1C shown in Figure 15, the outer body may be divided into a ventral part 3C and a dorsal part 6C. Diaper 1C consists of a rectangular ventral part 3C that is placed on the wearer's ventral side, a rectangular dorsal part 6C that is placed on the wearer's dorsal side, and a crotch area 9C that includes an absorbent body fixed across the ventral part 3C and the dorsal part 6C. The crotch area 9C has a crotch outer body 90 and an absorbent body (including a surface sheet, an absorbent body, and a back sheet). The crotch outer body 90 together with the ventral part 3C and the dorsal part 6C constitute the outer body of diaper 1C. The dorsal part 6C has a dorsal extension 60. The side edges of the dorsal portion 6C and the side edges of the ventral portion 3C are joined together to form a pair of side seals 8. Side reinforcement portions 105 are provided on the dorsal extension side edges 104 of the dorsal extension portion 60.

[0154] In diaper 1C, as with diaper 1, a first, second, and third configuration can be achieved to create a diaper that is gentle on the skin. In diaper 1C, as with diaper 1, the first to third configurations can be realized by appropriately adjusting the fineness, stretch rate, and spacing of the elastic material 78 placed in the ventral portion 3C and the dorsal portion 6C.

[0155] With regard to the embodiments of the present invention described above, the following additional information is disclosed. <1> A pant-type absorbent article comprising an absorbent body and an outer body positioned on the non-skin-facing side of the absorbent body, having a waist opening and a pair of leg openings, having a longitudinal direction extending from the wearer's abdominal side through the crotch to the back, and a transverse direction perpendicular to the longitudinal direction, The exterior body is, A ventral portion positioned on the wearer's abdominal side and having an ventral waist end that constitutes the waist opening, A back portion positioned on the back of the wearer, having a back waist end that constitutes the waist opening, A pair of side seals, each joined to the lateral edge of the ventral portion and the lateral edge of the dorsal portion in the lateral direction, It has, The dorsal waist end is located further from the pair of leg openings in the longitudinal direction than the ventral waist end, The rear side portion of the exterior body is A dorsal extension extending from the ventral waist end to the dorsal waist end in the longitudinal direction, The dorsal main body portion obtained by removing the dorsal extension portion from the dorsal portion, It has, The dorsal extension is, A pair of dorsal extension side edges, each facing each other in the lateral direction and extending in the longitudinal direction, A pair of side reinforcing portions provided on each of the pair of dorsal extension side edges and It has, The side seal has an upper end and a lower end that are opposite to each other in the longitudinal direction and extend in the lateral direction, The side reinforcement portion has an upper end and a lower end that are opposite to each other in the vertical direction and extend in the horizontal direction, The aforementioned back portion has an upper back portion located around the wearer's waist, The ventral portion has a ventral upper portion that is in the same position as the dorsal upper portion in the longitudinal direction, The dorsal extension, the dorsal upper part, and the ventral upper part each have one or more elastic bodies that extend laterally and are expandable in the later direction, In the natural length state, the first intersection angle, which is the intersection angle between a first imaginary line, which is a straight line passing through the first point on the outermost side of the upper end of the side seal and the second point on the outermost side of the lower end of the side seal, and a second imaginary line, which is a straight line passing through the third point on the outermost side of the upper end of the side reinforcement and the fourth point on the outermost side of the lower end of the side reinforcement, is 5 degrees or more and 30 degrees or less, and the third point is located laterally inward from the first imaginary line. When worn, the second intersection angle, which is the intersection angle between the third imaginary line (a straight line parallel to the vertical direction passing through the fourth point) and the second imaginary line, is between 10 degrees and 70 degrees, and the third point is located on the dorsal side of the third imaginary line. The first crossing angle is smaller than the second crossing angle. Absorbent pants. <2> The dorsal main body portion has a first region adjacent to the dorsal extension portion in the longitudinal direction, the length of which in the longitudinal direction is the same as the length of the dorsal extension portion. The average elongation rate of the elastic body arranged in the dorsal extension is higher than the average elongation rate of the elastic body arranged in the first region. The aforementioned <1> The pant-type absorbent article described above. <3> The dorsal main body portion has a first region adjacent to the dorsal extension portion in the longitudinal direction, the length of which in the longitudinal direction is the same as the length of the dorsal extension portion. The average fineness of the elastic material arranged in the dorsal extension is higher than the average fineness of the elastic material arranged in the first region. The aforementioned <1> or <2> The pant-type absorbent article described above. <4> The dorsal main body portion has a first region adjacent to the dorsal extension portion in the longitudinal direction, the length of which in the longitudinal direction is the same as the length of the dorsal extension portion. The multiple elastic bodies arranged in the first region are arranged such that their fineness increases as they approach the back waist end. The aforementioned <1> ~ <3> A pant-type absorbent article described in any one of the following. <5> When worn, the third intersection angle between the fourth imaginary line, which is a straight line passing through the fifth point (the center of the side seal in the vertical direction and the outermost point in the horizontal direction) and the third point, and the third imaginary line is 5 degrees or more and 60 degrees or less. The aforementioned <1> ~ <4> A pant-type absorbent article described in any one of the following. <6> The back portion of the main body is divided into three equal parts in the vertical direction, and has the upper back portion, the middle back portion, and the lower back portion, which are located in the vertical direction from the side closest to the waist opening. The ventral portion has the ventral upper portion and the ventral middle portion which is in the same position as the dorsal middle portion in the longitudinal direction. The ventral middle portion has greater lateral contractile stress than the dorsal middle portion, and the dorsal upper portion has greater lateral contractile stress than the ventral upper portion. The aforementioned <1> ~ <5> A pant-type absorbent article described in any one of the following. <7> The back portion of the main body is divided into three equal parts in the vertical direction, and has the upper back portion, the middle back portion, and the lower back portion, which are located in the vertical direction from the side closest to the waist opening. The ventral portion has the ventral upper portion and the ventral middle portion which is in the same position as the dorsal middle portion in the longitudinal direction. The number of elastic bodies located in the ventral middle section is greater than the number of elastic bodies located in the dorsal middle section. The aforementioned <1> ~ <6> A pant-type absorbent article described in any one of the following. <8> When worn, the lateral width of the dorsal extension is continuously narrowed toward the dorsal waist end. The aforementioned <1> ~ <7> A pant-type absorbent article described in any one of the following. <9> The back portion of the main body is divided into three equal parts in the vertical direction, and has the upper back portion, the middle back portion, and the lower back portion, which are located in the vertical direction from the side closest to the waist opening. When worn, the dorsal extension and the upper dorsal portion are provided with vertical folds extending in the longitudinal direction. The aforementioned <1> ~ <8> A pant-type absorbent article described in any one of the following. <10> The aforementioned dorsal extension has a laminated outer layer sheet and an inner layer sheet, The elastic body disposed in the dorsal extension is positioned between the outer layer sheet and the inner layer sheet. The dorsal extension has a joint where the outer layer sheet and the inner layer sheet are partially joined. The elastic body positioned in the dorsal extension has both ends in the longitudinal direction joined to the outer layer sheet and the inner layer sheet, but its central part in the longitudinal direction is not joined to the outer layer sheet and the inner layer sheet. The aforementioned <1> ~ <9> A pant-type absorbent article described in any one of the following. <11> The aforementioned joint is formed by heat sealing. In the aforementioned dorsal extension, there is no adhesive between the outer layer sheet and the inner layer sheet. The aforementioned <10> The pant-type absorbent article described above. <12> The side reinforcement portion is continuous with the side seal and includes a plurality of sealing portions formed by pressurizing means and / or heating means. The aforementioned <1> ~ <11> A pant-type absorbent article described in any one of the following. <13> The dorsal main body portion has a first region adjacent to the dorsal extension portion in the longitudinal direction, the length of which in the longitudinal direction is the same as the length of the dorsal extension portion. The average elongation rate of the elastic body arranged in the dorsal extension is 1.5 times or more and 5.0 times or less. The average elongation ratio of the elastic body placed in the first region is 1.2 times or more and 4.0 times or less. The aforementioned <1> ~ <12> A pant-type absorbent article described in any one of the following. <14> The dorsal main body portion has a first region adjacent to the dorsal extension portion in the longitudinal direction, the length of which in the longitudinal direction is the same as the length of the dorsal extension portion. The shrinkage stress of the dorsal extension is 20 cN / 10 mm or more and 65 cN / 10 mm or less. The shrinkage stress in the first region is 10 cN / 10 mm or more and 60 cN / 10 mm or less. The aforementioned <1> ~ <13> A pant-type absorbent article described in any one of the following. <15> The dorsal main body portion has a first region adjacent to the dorsal extension portion in the longitudinal direction, the length of which in the longitudinal direction is the same as the length of the dorsal extension portion. The average fineness of the elastic material in the dorsal extension is 250 dtex or more and 800 dtex or less. The average fineness of the elastic material in the first region is 200 dtex or more and 750 dtex or less. The aforementioned <1> ~ <14> A pant-type absorbent article described in any one of the following. <16> The back portion of the main body is divided into three equal parts in the vertical direction, and has the upper back portion, the middle back portion, and the lower back portion, which are located in the vertical direction from the side closest to the waist opening. The ventral portion has, in order from the side closest to the waist opening in the longitudinal direction, the upper ventral portion, the middle ventral portion which is in the same position as the middle dorsal portion in the longitudinal direction, and the lower ventral portion. The shrinkage stress of the dorsal extension is 20 cN / 10 mm or more and 65 cN / 10 mm or less. The shrinkage stress in the upper dorsal portion is 5 cN / 10 mm or more and 50 cN / 10 mm or less. The shrinkage stress in the dorsal intermediate portion is 0 cN / 10 mm or more and 40 cN / 10 mm or less. The contraction stress in the lower dorsal portion is 5 cN / 10 mm or more and 50 cN / 10 mm or less. The contractile stress in the ventral upper portion is 5 cN / 10 mm or more and 50 cN / 10 mm or less. The contractile stress in the ventral middle portion is 8 cN / 10 mm or more and 55 cN / 10 mm or less. The contractile stress in the ventral lower portion is 5 cN / 10 mm or more and 50 cN / 10 mm or less. The aforementioned <1> ~ <15> A pant-type absorbent article described in any one of the following. <17> The back portion of the main body is divided into three equal parts in the vertical direction, and has the upper back portion, the middle back portion, and the lower back portion, which are located in the vertical direction from the side closest to the waist opening. The ventral portion has, in order from the side closest to the waist opening in the longitudinal direction, the upper ventral portion, the middle ventral portion which is in the same position as the middle dorsal portion in the longitudinal direction, and the lower ventral portion. The plurality of elastic bodies arranged in the ventral and dorsal portions each have a first to fourth elastic body with different finenesses. In the dorsal portion, The dorsal upper portion includes a first region having the same length as the dorsal extension and the longitudinal length, Three of the first elastic bodies are arranged in the dorsal extension portion. One first elastic body and three second elastic bodies are arranged on the upper dorsal side, and the one first elastic body and two of the three second elastic bodies are arranged in the first region. Four of the third elastic bodies are arranged in the dorsal intermediate portion, Four of the fourth elastic bodies are arranged on the lower dorsal side, In the ventral portion, Five of the second elastic bodies are arranged on the upper ventral portion, Four of the third elastic bodies are arranged in the ventral intermediate portion, Four of the fourth elastic bodies are arranged in the lower ventral portion. The aforementioned <1> ~ <16> A pant-type absorbent article described in any one of the following. <18> The first elastic material has a fineness of 470 dtex and an elongation ratio of 3.2 times. The second elastic material has a fineness of 310 dtex and an elongation ratio of 2.8 times. The third elastic material has a fineness of 780 dtex and an elongation ratio of 2.7 times. The fourth elastic material has a fineness of 620 dtex and an elongation ratio of 2.5 times. The aforementioned <17> The pant-type absorbent article described above. <19> The ventral portion has a folded portion formed by the folding of the outer casing, The four first elastic bodies, three second elastic bodies, and four third elastic bodies arranged on the dorsal side are intermittently arranged at equal intervals in the longitudinal direction. Of the four fourth elastic bodies arranged on the dorsal side, the spacing between the two upper fourth elastic bodies and the spacing between the two lower fourth elastic bodies are the same. In the ventral portion, one of the second elastic bodies is arranged in the folded portion, and the four second elastic bodies and four of the third elastic bodies arranged outside the folded portion are intermittently arranged at equal intervals in the longitudinal direction. Of the four fourth elastic bodies arranged in the ventral portion other than the folded portion, the spacing between the two upper fourth elastic bodies and the spacing between the two lower fourth elastic bodies are the same. The aforementioned <17> or <18> The pant-type absorbent article described above. <20> The back portion of the main body is divided into three equal parts in the vertical direction, and has the upper back portion, the middle back portion, and the lower back portion, which are located in the vertical direction from the side closest to the waist opening. The ventral portion has, in order from the side closest to the waist opening in the longitudinal direction, the upper ventral portion, the middle ventral portion which is in the same position as the middle dorsal portion in the longitudinal direction, and the lower ventral portion. In the dorsal portion, Three elastic bodies are arranged in the dorsal extension portion. Four elastic bodies are arranged on the upper part of the dorsal side, Four elastic bodies are arranged in the aforementioned dorsal intermediate portion. Four elastic bodies are arranged on the lower back side, In the ventral portion, Five elastic bodies are arranged on the upper ventral side, Four elastic bodies are arranged in the ventral middle portion, Four elastic bodies are arranged in the lower ventral portion, Of the multiple elastic bodies arranged in the dorsal and ventral portions, the two lower elastic bodies of the four elastic bodies arranged in the dorsal middle portion, the two lower elastic bodies of the four elastic bodies arranged in the ventral middle portion, the four elastic bodies arranged in the lower dorsal portion, and the four elastic bodies arranged in the lower ventral portion are discontinuous elastic bodies, while the other elastic bodies are continuous elastic bodies. The aforementioned <1> ~ <19> A pant-type absorbent article described in any one of the following. <21> The aforementioned ventral upper part is constructed by folding back the outer casing and stacking the outer casing in two layers. In the upper ventral portion, of the two stacked outer layers, four elastic bodies are arranged in the outer layer located on the non-skin side, and one elastic body is arranged in the outer layer located on the skin side. One elastic body, which is positioned on the skin side of the upper ventral portion of the outer casing, is located in the upper region when the upper ventral portion is divided into two equal parts in the longitudinal direction. The aforementioned <1> ~ <20> A pant-type absorbent article described in any one of the following. <22> The aforementioned dorsal extension is formed by folding the outer casing back and stacking two layers of the outer casing, In the dorsal extension, of the two stacked outer layers, two elastic bodies are provided in the outer layer located on the non-skin side, and one elastic body is provided in the outer layer located on the skin side. One elastic body, which is positioned on the skin side of the dorsal extension, is located in the upper region when the dorsal extension is divided into two equal parts in the vertical direction. The aforementioned <21> The pant-type absorbent article described above. <23> The absorbent body has a dorsal end of the absorbent body, which is the longitudinal end located on the dorsal side, and a ventral end of the absorbent body, which is the longitudinal end located on the ventral side. The dorsal end and ventral end of the absorbent body are located at the same position in the longitudinal direction. The aforementioned <1> ~ <22> A pant-type absorbent article described in any one of the following. <24> The ventral portion and the dorsal portion each have a rectangular shape. It has a crotch area that is fixed across the ventral and dorsal portions, The aforementioned crotch area includes the crotch outer casing and the absorbent main body. The crotch outer covering, together with the ventral and dorsal portions, constitutes the outer covering. The aforementioned <1> ~ <23> A pant-type absorbent article described in any one of the following. [Explanation of symbols]

[0156] 1, 1A, 1B, 1C... Absorbent pants (disposable diapers, diapers) 1W…Waist opening 1L... Leg opening 3, 3C…ventral part 4… Absorbent body 5…Exterior 6, 6C...dorsal part 8... Side seal 8a... Upper end of side seal 8b... Lower end of side seal 32…Upper ventral side 60...Dorsal extension part 61...Dorsal body part 62…upper dorsal side 101...Ventral waist end 102...Rear waist end 104...Dorsal extension side edge 105...Side reinforcement 105a... Upper end of side reinforcement section 105b...Lower end of side reinforcement section L1…First virtual line L2…Second virtual line L3...Third virtual line P1…1st point P2…Second point P3…3rd point P4…4th point θ1…First intersection angle θ2…Second crossing angle

Claims

1. A pant-type absorbent article comprising an absorbent body and an outer body positioned on the non-skin-facing side of the absorbent body, having a waist opening and a pair of leg openings, having a longitudinal direction extending from the wearer's abdominal side through the crotch to the back, and a transverse direction perpendicular to the longitudinal direction, The exterior body is, A ventral portion positioned on the wearer's abdominal side and having an ventral waist end that constitutes the waist opening, A back portion positioned on the back of the wearer, having a back waist end that constitutes the waist opening, A pair of side seals, each joined to the lateral edge of the ventral portion and the lateral edge of the dorsal portion in the lateral direction, It has, The dorsal waist end is located further from the pair of leg openings in the longitudinal direction than the ventral waist end, The rear side portion of the exterior body is A dorsal extension extending from the ventral waist end to the dorsal waist end in the longitudinal direction, The dorsal main body portion obtained by removing the dorsal extension portion from the dorsal portion, It has, The dorsal extension is, A pair of dorsal extension side edges, each facing each other in the lateral direction and extending in the longitudinal direction, A pair of side reinforcing portions provided on each of the pair of dorsal extension side edges and It has, The side seal has an upper end and a lower end that are opposite to each other in the longitudinal direction and extend in the lateral direction, The side reinforcement portion has an upper end and a lower end that are opposite to each other in the vertical direction and extend in the horizontal direction, The aforementioned back portion has an upper back portion located around the wearer's waist, The ventral portion has a ventral upper portion that is in the same position as the dorsal upper portion in the longitudinal direction, The dorsal extension, the dorsal upper part, and the ventral upper part each have one or more elastic bodies that extend laterally and are expandable in the later direction, In the natural length state, the first intersection angle, which is the intersection angle between a first imaginary line, which is a straight line passing through the first point on the outermost side of the upper end of the side seal and the second point on the outermost side of the lower end of the side seal, and a second imaginary line, which is a straight line passing through the third point on the outermost side of the upper end of the side reinforcement and the fourth point on the outermost side of the lower end of the side reinforcement, is 5 degrees or more and 30 degrees or less, and the third point is located laterally inward from the first imaginary line. When worn, the second intersection angle, which is the intersection angle between the third imaginary line (a straight line parallel to the vertical direction passing through the fourth point) and the second imaginary line, is between 10 degrees and 70 degrees, and the third point is located on the back side of the third imaginary line. The first crossing angle is smaller than the second crossing angle. Absorbent pants.

2. The dorsal main body portion has a first region adjacent to the dorsal extension portion in the longitudinal direction, the length of which in the longitudinal direction is the same as the length of the dorsal extension portion. The average elongation rate of the elastic body arranged in the dorsal extension is higher than the average elongation rate of the elastic body arranged in the first region. The pant-type absorbent article according to claim 1.

3. The dorsal main body portion has a first region adjacent to the dorsal extension portion in the longitudinal direction, the length of which in the longitudinal direction is the same as the length of the dorsal extension portion. The average fineness of the elastic material arranged in the dorsal extension is higher than the average fineness of the elastic material arranged in the first region. The pant-type absorbent article according to claim 1 or 2.

4. The dorsal main body portion has a first region adjacent to the dorsal extension portion in the longitudinal direction, the length of which in the longitudinal direction is the same as the length of the dorsal extension portion. The plurality of elastic bodies arranged in the first region are arranged such that their fineness increases as they approach the back waist end. The pant-type absorbent article according to claim 1 or 2.

5. When worn, the third intersection angle between the fourth imaginary line, which is a straight line passing through the fifth point (the center of the side seal in the vertical direction and the outermost point in the horizontal direction) and the third point, and the third imaginary line is 5 degrees or more and 60 degrees or less. The pant-type absorbent article according to claim 1 or 2.

6. The back portion is divided into three equal parts in the vertical direction, and has the upper back portion, the middle back portion, and the lower back portion, which are located in the vertical direction from the side closest to the waist opening. The ventral portion has the ventral upper portion and the ventral middle portion which is in the same position as the dorsal middle portion in the longitudinal direction. The ventral middle portion has greater lateral contractile stress than the dorsal middle portion, and the dorsal upper portion has greater lateral contractile stress than the ventral upper portion. The pant-type absorbent article according to claim 1 or 2.

7. The back portion is divided into three equal parts in the vertical direction, and has the upper back portion, the middle back portion, and the lower back portion, which are located in the vertical direction from the side closest to the waist opening. The ventral portion has the ventral upper portion and the ventral middle portion which is in the same position as the dorsal middle portion in the longitudinal direction. The number of elastic bodies located in the ventral middle section is greater than the number of elastic bodies located in the dorsal middle section. The pant-type absorbent article according to claim 1 or 2.

8. When worn, the lateral width of the dorsal extension is continuously narrowed toward the dorsal waist end. The pant-type absorbent article according to claim 1 or 2.

9. The back portion is divided into three equal parts in the vertical direction, and has the upper back portion, the middle back portion, and the lower back portion, which are located in the vertical direction from the side closest to the waist opening. When worn, the dorsal extension and the upper dorsal portion are provided with vertical folds extending in the longitudinal direction. The pant-type absorbent article according to claim 1.

10. The aforementioned dorsal extension has a laminated outer layer sheet and an inner layer sheet, The elastic body disposed in the dorsal extension is positioned between the outer layer sheet and the inner layer sheet. The dorsal extension has a joint where the outer layer sheet and the inner layer sheet are partially joined. The elastic body positioned in the dorsal extension has both ends in the longitudinal direction joined to the outer layer sheet and the inner layer sheet, but its central part in the longitudinal direction is not joined to the outer layer sheet and the inner layer sheet. The pant-type absorbent article according to claim 1 or 2.

11. The aforementioned joint is formed by heat sealing. In the aforementioned dorsal extension, there is no adhesive between the outer layer sheet and the inner layer sheet. The pant-type absorbent article according to claim 10.

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