Absorbent panty-type items

Abstract

The present invention relates to providing a pant-type absorbent article that is less likely to roll up on the back and offers excellent wearing comfort. [Solution] The pant-type absorbent article according to one embodiment comprises an absorbent body and an outer casing. The outer casing has a ventral portion, a dorsal portion, and a side seal formed by joining the side edge of the ventral portion and the side edge of the dorsal portion. The dorsal portion has a dorsal extension and a dorsal main body portion. The side seal has an upper end and a lower end. The dorsal main body portion has a dorsal upper portion that is closest to the upper end of the side seal when it is divided into three equal regions in the longitudinal direction. 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 has a higher shrinkage stress than the dorsal upper portion and the ventral upper portion. When the dorsal upper portion is divided into a first dorsal upper portion and a second dorsal upper portion that are arranged sequentially from top to bottom in the longitudinal direction, the dorsal extension has a higher shrinkage stress than the first dorsal upper portion, and the first dorsal upper portion has a higher shrinkage stress than the second dorsal upper portion.

Description

Technical Field

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

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 side end portions. The waist portion of the pants-type absorbent article is formed by joining the ventral exterior body and the dorsal exterior body via the side seals.

[0003] Patent Documents 1 and 2 disclose pants-type absorbent articles having a dorsal extending portion on the waist side of the dorsal side of the exterior body. With such a configuration, for example, excreta such as loose stool can be prevented from leaking from the dorsal side.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Patent Document 2

Summary of the Invention

Problems to be Solved by the Invention

[0005] In a pants-type absorbent article provided with a dorsal extending portion, there is a problem that the long dorsal portion makes the dorsal extending portion prone to curling up during wearing, and the performance of suppressing excreta leakage cannot be fully exhibited. On the other hand, if the contraction stress of the elastic body in the waist portion of the pants-type absorbent article is simply increased in order to suppress excreta leakage from the dorsal side, wearing comfort will be impaired.

[0006] The present invention relates to a pants-type absorbent article in which the dorsal extending portion is less likely to curl up and which has excellent wearing comfort.

Means for Solving the Problems

[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 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, It has a pair of side seals, each formed by joining the lateral edge of the ventral portion in the lateral direction with the lateral edge of the dorsal portion in the lateral direction. 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, It has a dorsal main body portion obtained by removing the dorsal extension portion from the dorsal portion. The above-mentioned side seal has an upper end and a lower end that are opposite to each other in the vertical direction. The rear body portion has a rear upper portion which is the region closest to the upper end of the side seal when the rear body portion is divided into three equal parts in the vertical direction. 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 has a higher lateral contraction stress than the dorsal upper portion and the ventral upper portion. When the upper dorsal portion is divided vertically into two equal parts, a first upper dorsal portion and a second upper dorsal portion, which are arranged sequentially from the upper end of the side seal towards the lower end of the side seal, the dorsal extension portion has a higher lateral shrinkage stress than the first upper dorsal portion, and the first upper dorsal portion has a higher lateral shrinkage stress than the second upper dorsal portion. [Effects of the Invention]

[0008] According to the present invention, the pant-type absorbent article has a back extension that is less likely to roll up and offers excellent wearing comfort. [Brief explanation of the drawing]

[0009] [Figure 1] This is a schematic perspective view showing a pant-type absorbent article according to the first to third embodiments of the present invention. [Figure 2] (A) is a schematic side view of the above-mentioned pant-type absorbent article, and (B) is an enlarged view of the area enclosed by circle IIB in (A). [Figure 3] This is a schematic plan view showing the skin-facing side of the pant-type absorbent article of the first embodiment, and is a diagram showing the pant-type absorbent article unfolded and each elastic body stretched out to form a flat surface. [Figure 4] (A) is a schematic side view showing the arrangement of the elastic bodies of the pant-type absorbent article of the first embodiment, and (B) is a schematic partial plan view illustrating the arrangement relationship of the elastic bodies of the ventral and dorsal portions and the dorsal extension portion joined by the side seal of the pant-type absorbent article of the first embodiment, and shows each elastic body stretched out in a planar shape. [Figure 5] This is a schematic cross-sectional view of the side seal and side reinforcement portion of the pant-type absorbent article according to the first embodiment. [Figure 6] This is a schematic plan view showing the side seal and side reinforcement of a pant-type absorbent garment. [Figure 7] This is a schematic cross-sectional view of the side seal and side reinforcement portion of a modified pant-type absorbent article of the present invention. [Figure 8] (A) is a schematic side view showing the arrangement of elastic bodies in a pant-type absorbent article of the second embodiment of the present invention, and (B) is a schematic partial plan view illustrating the arrangement relationship of elastic bodies in the ventral and dorsal portions and the dorsal extension portion joined by the side seal of a pant-type absorbent article of the third embodiment, showing the elastic bodies of each portion stretched out into a planar shape. [Figure 9] It is a schematic cross-sectional view showing the side seal and the side reinforcement portion of the pants-type absorbent article according to the third embodiment of the present invention. [Figure 10] It is a schematic cross-sectional view showing the side seal and the side reinforcement portion of the pants-type absorbent article according to the fourth embodiment of the present invention. [Figure 11] It is a schematic perspective view showing the pants-type absorbent article according to the fifth embodiment of the present invention. [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>

[0012] [Overall Configuration of Pants-type Absorbent Article] Fig. 1, Fig. 2(A) and Fig. 3 show a pants-type disposable diaper 1 as the pants-type absorbent article according to the first embodiment of the present invention. Hereinafter, the pants-type disposable diaper 1 is referred to as the diaper 1. Fig. 2(A) schematically shows the diaper 1 when worn, and the wearer's torso 13 and legs 14 are also illustrated. Fig. 3 shows a state where the diaper 1 is unfolded, the elastic members of each part are stretched, and the diaper 1 is spread flat so as to have the design dimensions in a state where the influence of the elastic members is completely eliminated.

[0013] As shown in Fig. 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 extends from the abdominal side of the wearer through the crotch portion to the back side. The lateral direction Y is orthogonal to the longitudinal direction X and corresponds to the left-right direction of the wearer. Further, as shown in Fig. 2(A) and the like, the direction orthogonal to the longitudinal direction X and the lateral direction Y of the diaper 1 is defined as a thickness direction Z. As shown in Fig. 2(A) and the like, in the diaper 1 that is worn at the correct position by a wearer in a standing posture, the longitudinal direction X is parallel to the vertical direction.

[0014] In this specification, "waist side" and "upper side" mean the side in the vertical direction X that is closer to the waist opening end Wa of the waist opening 1W and away from the leg opening 1L. "Leg side" and "lower side" mean the side in the vertical direction X that is away from the waist opening end Wa and closer to the leg opening 1L. In this specification, "inside of transverse direction Y" means the side of the diaper (pant-type absorbent article) that is closer to the vertical center line CL that bisects the transverse direction Y, and "outside of transverse direction Y" means the side that is further away from the vertical center line CL. 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.

[0015] 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 "wearing."

[0016] As shown in Figures 1, 2(A), 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 81 to 84, 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.

[0017] 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 5). 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.

[0018] 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.

[0019] 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.

[0020] 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. 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.

[0021] 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 5. 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 81 to 84 are arranged between the inner layer sheet 52 and the outer layer sheet 51.

[0022] Furthermore, the diaper 1 is further equipped with a disposal tape having a handle portion, which is positioned on the back side 6 so as to overlap with the absorbent body 4 in a plan view.

[0023] 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.

[0024] [Exterior structure] As shown in Figures 1, 2(A), and 3, the outer garment 5 has a ventral portion 3, a crotch portion 9, and a dorsal portion 6. The ventral portion 3 of the outer garment 5 has a ventral waist end 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 102 that constitutes the waist opening end Wa of the waist opening 1W. The dorsal waist end 102 is located further from the pair of leg openings 1L in the longitudinal direction X than the ventral waist end 101. The dorsal waist end 102 is the end (dorsal extension end) of the dorsal extension portion 60. In the illustrated example, the dorsal waist end 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.

[0025] The dorsal portion 6 and the ventral portion 3 each have multiple elastic bodies that extend in the transverse direction Y and are intermittently arranged in the longitudinal direction X, and are expandable and contractible in the transverse direction Y. By adjusting the contraction stress per elastic body according to the position where the elastic bodies are arranged, the curling of the dorsal extension portion 60 can be effectively suppressed, and a diaper 1 with excellent wearing comfort can be made. Further details will be described later.

[0026] (Composition of the dorsal side) The dorsal portion 6 of the outer casing 5 has a dorsal extension 60 and a dorsal main body portion 61. The dorsal extension 60 extends in the longitudinal direction X 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 portion 61 is the portion of the dorsal portion 6 excluding the dorsal extension 60. In other words, the dorsal main body portion 61 is the portion that is in the same position as the ventral portion 3 in the longitudinal direction X, while the dorsal extension 60 is the portion that does not face the ventral portion 3 and protrudes upward in the longitudinal direction X. As shown in Figures 1 and 3, the boundary between the dorsal extension 60 and the dorsal main body portion 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 from the dorsal extension 60. 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 curl inward when you grab the dorsal part 6 and pull 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.

[0027] The dorsal main body portion 61 of the dorsal portion 6 is divided into three regions by dividing the dorsal main body portion 61 into three equal parts in the vertical direction X, as shown in Figures 3, 4(A), and (B): the dorsal upper portion 62, the dorsal middle portion 63, and the dorsal lower portion 64. The dorsal upper portion 62 is the region of the three regions 62-64 that is closest to the upper end portion 8a of the side seal. The dorsal lower portion 64 is the region of the three regions 62-64 that is closest to the lower end portion 8b of the side seal. The dorsal portion 6 is divided into four parts: the dorsal extension portion 60, the dorsal upper portion 62, the dorsal middle portion 63, and the dorsal lower portion 64, which are arranged in order from the waist opening 1W toward the leg opening 1L.

[0028] Furthermore, as shown in Figures 4(A) and (B), the dorsal upper portion 62 is divided into two regions, the first dorsal upper portion 621 and the second dorsal upper portion 622, which are obtained by bisecting the dorsal upper portion 62 in the vertical direction X. The first dorsal upper portion 621 and the second dorsal upper portion 622 are arranged in order from the upper end 8a of the side seal to the lower end 8b of the side seal.

[0029] As shown in Figures 1, 2(A), and (B), the dorsal extension portion 60 has a pair of dorsal extension side edges 104 that are opposite each other in the lateral direction Y and extend in the vertical direction X, and a pair of side reinforcing portions 105 provided on each of the pair of dorsal extension side edges 104. Each of the 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 seal 8 will be described later.

[0030] (Composition of the ventral part) As shown in Figures 3, 4(A), and 4(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.

[0031] 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 stretched state shown in Figure 4(B), the ventral portion and the dorsal portion are adjacent and their position and length in the longitudinal direction X coincide. In diaper 1, the ventral upper portion 32 and the dorsal upper portion 62 are joined by the side seal 8 to form a ring and are located near the wearer's abdomen. Similarly, the ventral middle portion 33 and the dorsal middle portion 63 form a ring and are located approximately near the wearer's iliac crest when worn. Similarly, the ventral lower portion 34 and the dorsal lower portion 64 form a ring. On the other hand, the dorsal extension 60 is not ring-shaped because there is no ventral portion at the same position in the longitudinal direction X, and is provided with a pair of free ends, dorsal extension side edges 104, on both sides in the transverse direction Y.

[0032] [Composition of the absorbent body] Figure 5 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 5 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). The side seal 8 is constructed by joining a dorsal body portion 61 and a ventral portion 3, but in Figure 5, the dorsal portion 6 and the ventral portion 3 are shown separated for convenience, and similarly in Figure 9, which shows the diaper 1C of the third embodiment described later, and Figure 10, which shows the diaper 1D of the fourth embodiment, the dorsal body portion 61 and the ventral portion 3 are shown separated. As shown in Figure 5, the outer casing 5 is folded back towards the skin-facing side at the ventral waist end 101 and the dorsal waist end 102. These folded portions (folded portion 80, folded portion 86) are positioned to cover the dorsal end 106 and the ventral end 107 of the absorbent body. The same applies to Figures 9 and 10, which illustrate the third and fourth embodiments described later.

[0033] As shown in Figures 3 and 5, 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).

[0034] 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.

[0035] 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 than the ends of the absorbent material 40 in the vertical direction X.

[0036] The absorbent body 40 of the absorbent main body 4 has an absorbent core (not shown) and a core wrap sheet (not shown).

[0037] 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.

[0038] 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.

[0039] 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.

[0040] The ventral end 107 of the absorbent body is located closer to the leg opening 1L in the longitudinal direction X than the dorsal end 106 of the absorbent body. In other words, in the longitudinal direction X, the dorsal end 106 of the absorbent body is located closer to the waist than the ventral end 107 of the absorbent body.

[0041] [Configuration of side seal and side reinforcement] A pair of side seals 8, each extending in the vertical direction X, cause the ventral portion 3 and the dorsal main body portion 61 to form a tubular shape that conforms to the wearer's waist, creating the waist opening 1W and leg openings 1L of the diaper 1. As shown in Figure 6, the side seals 8 typically include multiple sealing portions S.

[0042] 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.

[0043] The pair of side reinforcement portions 105 are provided on the pair of back extension side edges 104 of the back extension portion 60 and are continuous with the side seal 8. As shown in Figure 6, 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.

[0044] In the example shown in Figure 6, the sealing portion S has a rectangular shape with the horizontal direction Y as its longitudinal direction. Multiple sealing portions S are intermittently arranged along the vertical direction X.

[0045] As shown in Figure 6, in the side seal 8 (side reinforcement portion 105), the rectangular area surrounding the entire contour of the multiple seal portions S is referred to as 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.

[0046] As shown in Figure 6, 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 6, 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 side Y of the sealing region B are located laterally 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.

[0047] As shown in Figure 6, the width range of the rectangular side reinforcement portion 105, which extends in a band shape in the vertical direction, is defined as extending from the side edge on the inside of the sealing region 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 6, 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.

[0048] The side reinforcement portion 105 is a highly rigid part due to the presence of multiple seal 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, as will be described in detail later, multiple first elastic bodies 81 are arranged on the dorsal extension portion 60. By having a pair of side reinforcement portions 105 at both ends in the lateral direction Y of the multiple first elastic bodies 81, 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. In addition, because the side reinforcement portion 105 and the side seal 8 are continuous, the dorsal extension portion 60 is less likely to bend at the boundary portion 110 between the side reinforcement portion 105 and the side seal 8, and consequently, bending of the dorsal extension portion 60 at the boundary portion 103 is suppressed. Furthermore, since the pair of side reinforcement sections 105 are continuous with the side seal 8 and have a configuration that includes multiple similar sealing sections S, the diaper 1 can be manufactured easily without increasing the manufacturing process or materials.

[0049] Each pair of side seals 8 has an upper end portion 8a and a lower end portion 8b, which constitute both ends in the vertical direction X. Each pair of side seals 8 is continuous with a side reinforcing portion 105 provided on each of the pair of back extension side edges 104 of the back extension portion 60, and the side reinforcing portion 105 is in the form of an extension of the side seal 8. The side reinforcing portion 105 is not required, but it is more preferable to provide the side reinforcing portion 105 from the viewpoint of further suppressing curling of the back extension portion 60.

[0050] 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.

[0051] As shown in Figures 2(A) and (B), 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 of the side reinforcement portion is located at the back waist end portion 102. The lower end portion 105b of the side reinforcement portion 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 2(B), the boundary portion 110 is virtually shown with a thick dashed line.

[0052] As shown in Figure 2(A), in the diaper 1 of this embodiment, the imaginary line 17 connecting the upper end (corresponding to the upper end 105a of the side reinforcement portion 105a) and the lower end (corresponding to the lower end 8b of the side seal) of the entire side seal 8 and the side reinforcement portion 105 continuous therewith is a line that is diagonal to the vertical direction X, with the upper end located on the back side of the lower end. With this configuration, the side seal 8 and the side reinforcement portion 105 continuous with the side seal 8 tend to be positioned diagonally with respect to the vertical direction X, with the upper side (side of the upper end 105a of the side reinforcement portion) leaning towards the dorsal side and the lower side (side of the lower end 8b of the side seal) leaning towards the ventral side. As a result, for example, when a caregiver places their fingers near both sides of the waist opening 1W of the diaper 1 in the horizontal direction Y (near the side seal 8) to spread the diaper 1 and put it over the wearer's legs, and then pulls up the diaper 1, the middle or proximal joints of the caregiver's fingers 16 are less likely to get caught on the dorsal waist end 102, and the curling of the dorsal extension portion 60 is more easily suppressed.

[0053] [Relationship of contractile stress in the dorsal extension, dorsal upper part (first dorsal upper part and second dorsal upper part), and ventral upper part] In diaper 1, the dorsal extension 60 has a higher lateral Y-stress than the dorsal upper part 62 and the ventral upper part 32. In addition, the dorsal extension 60 has a higher lateral Y-stress than the first dorsal upper part 621, and the first dorsal upper part 621 has a higher lateral Y-stress than the second dorsal upper part 622. The method for measuring the lateral stress of each part will be described later. Furthermore, "lateral Y-stress" may be simply referred to as "stress" below.

[0054] When the diaper is worn, the ventral upper 32 and dorsal upper 62, which are joined by the side seal 8 and form a ring, are located near the wearer's abdomen, where waist circumference fluctuates significantly. Because the dorsal extension 60 has a higher contractile stress in the lateral direction Y than the dorsal upper 62 and ventral upper 32, the contractile force of the dorsal extension 60 can appropriately contract the dorsal upper 62 and ventral upper 32, which correspond to the entire abdomen, without excessively increasing the contractile stress of the dorsal upper 62 and ventral upper 32 located near the abdomen, allowing them to fit snugly against the wearer's skin. As a result, the dorsal upper 62 and ventral upper 32 can easily follow the wearer's waist circumference fluctuations without excessively compressing the wearer's abdomen, resulting in a diaper 1 with excellent wearing comfort. Furthermore, by relatively increasing the shrinkage stress of the dorsal extension portion 60, which is not ring-shaped and is prone to curling, the folds of the dorsal extension portion 60 become finer, increasing the basis weight of the constituent material, thereby increasing the rigidity of the dorsal extension portion 60, suppressing curling of the dorsal extension portion 60, and improving the fit to the wearer's skin.

[0055] In addition, in diaper 1, the first dorsal upper section 621 has a higher shrinkage stress than the second dorsal upper section 622, and the dorsal extension section 60 and the dorsal upper section 62 are configured such that the shrinkage stress gradually decreases from top to bottom without a sudden change in shrinkage stress. This configuration prevents the dorsal extension section 60 from folding and curling up starting near the area where the shrinkage stress changes abruptly, thereby suppressing curling of the dorsal extension section 60. In other words, in diaper 1, the dorsal upper section 62 and the ventral upper section 32, which are joined together to form a ring, have less contractile stress than the dorsal extension section 60, allowing them to easily follow changes in waist circumference without excessively compressing the wearer's abdomen, thus providing comfort during wear.

[0056] Thus, diaper 1 makes it possible to achieve both effective suppression of the dorsal extension portion 60 curling up and comfort during wear.

[0057] The contractile stress in each section (dorsal extension, dorsal upper section (first and second dorsal upper sections), ventral upper section) can be adjusted by the fineness, elongation rate, and spacing of the elastic materials placed in these sections. The method for measuring the elongation rate will be described later.

[0058] From the viewpoint of further suppressing bending of the dorsal extension due to abrupt changes in shrinkage stress, it is preferable that the difference between the shrinkage stress of the dorsal extension 60 and the shrinkage stress of the dorsal upper part 62 be 5 cN / 10 mm or more and 18 cN / 10 mm or less, and more preferably 7 cN / 10 mm or more and 15 cN / 10 mm or less. Furthermore, from the viewpoint of further improving wearing comfort, it is preferable that the difference between the contractile stress of the dorsal extension portion 60 and the contractile stress of the ventral upper portion 32 be 9 cN / 10 mm or more and 22 cN / 10 mm or less, and more preferably 11 cN / 10 mm or more and 19 cN / 10 mm or less.

[0059] (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:

[0060] ((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 width direction of the diaper, from the dorsal extension portion 60, the upper dorsal portion 62, and the upper ventral portion 32, respectively, to obtain strips or band-shaped samples of each part that extend across the entire lateral 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, to 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 cut should be made in the part other than the adjacent elastic body. Samples can be obtained by similarly cutting out the following regions: the first dorsal upper section 621, the second dorsal upper section 622, the dorsal middle section 63, the dorsal lower section 64, the ventral middle section 33, and the ventral lower section 34. The length (mm) in the longitudinal X direction and the transverse Y direction of each cut-out sample is recorded.

[0061] ((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.

[0062] [Elastic body] As shown in Figures 3, 4(A), and (B), in the diaper 1, multiple first to fourth elastic bodies 81 to 84 are arranged in the dorsal portion 6 and ventral portion 3, respectively, extending in the transverse direction Y and being expandable and contractible in the transverse direction Y. By appropriately adjusting the fineness, elongation rate, spacing, and number of elastic bodies arranged in each part, the contraction stress in the transverse direction Y of each part (dorsal extension 60, dorsal upper portion 62, first dorsal upper portion 621, second dorsal upper portion 622, dorsal middle portion 63, dorsal lower portion 64, ventral upper portion 32, ventral middle portion 33, ventral lower portion 34) can be adjusted. The method for measuring the contraction stress will be described later. The elastic bodies arranged in each part are fixed to the thermoplastic sheet 50 that constitutes the outer casing 5 in an extended state, and when the extended state is released and the elastic bodies contract, folds are naturally formed in the outer casing 5. The elastic bodies are fixed to the thermoplastic sheet 50, for example, by adhesive. In the example of diaper 1, the fineness of the first to fourth elastic bodies 81 to 84 are different, and in Figures 3, 4(A), and (B), elastic bodies with different finenesses are shown with different wire types.

[0063] From the viewpoint of ensuring the overall elasticity of the girth, the lateral Y-outer ends of the elastic bodies 81-84, which are arranged on the ventral portion 3 and the dorsal portion 6 respectively, are preferably located on or near the side seal 8 and the side reinforcement portion 105. Specifically, it is preferable that the distance in the lateral Y direction from the side seal 8 and the side reinforcement portion 105 of the end 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 and the side reinforcement portion 105.

[0064] The elongation rate of each of the first to fourth elastic bodies 81 to 84 represents the ratio of the length of the elastic body in the unfolded and stretched state of the pant-type absorbent article to the length of the elastic body in the natural length when removed from the pant-type absorbent article. 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 using a comb or the like, and the elastic body is fixed to the thermoplastic sheet 50 of the outer casing 5.

[0065] Figure 5 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 5, 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.

[0066] Multiple first to fourth elastic bodies 81 to 84 are arranged between multiple thermoplastic sheets 50 of the outer casing 5. In the example shown in Figure 5, the multiple elastic bodies 81 to 84 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 81 to 84 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 81 to 84 extend in the lateral direction Y" means that in the unfolded and extended state, the first to fourth elastic bodies 81 to 84 extend in the lateral direction Y. However, the above expression is not limited to the first to fourth elastic bodies 81 to 84 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 81 to 84 are parallel to the lateral direction Y. Furthermore, as shown in Figures 1 and 3, the outer casing 5 may include, in addition to the first to fourth elastic bodies 81 to 84, a leg elastic body 11 positioned around the leg opening 1L.

[0067] The first to fourth elastic bodies 81 to 84, 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 81 to 84, 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.

[0068] The first to fourth elastic bodies 81 to 84 are each positioned between a pair of side reinforcing parts 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 81 to 84 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.

[0069] As shown in Figure 4(B), in diaper 1, the first elastic body 81 includes three first elastic bodies 81a and one first elastic body 81b. The three first elastic bodies 81a are located in the dorsal extension portion 60. The one first elastic body 81b is located in the dorsal upper portion 62. All of the first elastic bodies 81 are continuous elastic bodies. In the figure, the first elastic bodies 81 are indicated by dashed lines. The second elastic body 82 includes two second elastic bodies 82a, three second elastic bodies 82b, and six second elastic bodies 82c. The two second elastic bodies 82a are located on the dorsal upper part 62 and are positioned below the first elastic body 81a. The three second elastic bodies 82b are located on the dorsal upper part 62. The six second elastic bodies 82c are located on the ventral upper part 32. The second elastic bodies 82a, 82b, and 82c are referred to as the second elastic body 82 unless there is a need to distinguish them, as they differ only in their location. All of the second elastic bodies 82 are continuous elastic bodies. In the figure, the second elastic body 82 is shown by a long dashed line. The third elastic body 83 includes two third elastic bodies 83a and four third elastic bodies 83b. The two third elastic bodies 83a are located in the dorsal intermediate section 63. The four third elastic bodies 83b are located in the ventral intermediate section 33. In the dorsal intermediate section 63, the uppermost third elastic body 83a is a continuous elastic body, and the lowermost third elastic body 83a is a discontinuous elastic body. In the ventral intermediate section 33, the two upper third elastic bodies 83b are continuous elastic bodies, and the two lower third elastic bodies 83b are discontinuous elastic bodies. The third elastic bodies 83a and 83b are simply referred to as the third elastic body 83 unless there is a need to distinguish between them, as they differ only in their location. In the figure, the third elastic body 83 is shown by a short dashed line. The fourth elastic body 84 includes four fourth elastic bodies 84a and four fourth elastic bodies 84b. The four fourth elastic bodies 84a are located in the dorsal lower part 64. The four fourth elastic bodies 84b are located in the ventral lower part 34. All of the fourth elastic bodies 84 are continuous elastic bodies. The fourth elastic bodies 84a and 84b are elastic bodies with the same fineness and elongation ratio, differing only in their location, and are referred to as the fourth elastic body 84 unless there is a need to distinguish between them. In the figure, the fourth elastic body 84 is shown by a dashed line.

[0070] As shown in Figure 4(B), the six elastic bodies located on the upper dorsal portion 62 and the six 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.

[0071] As shown in Figure 4(B), each elastic body located on the dorsal main body 61 may be positioned substantially the same as each elastic body located on the ventral body 3 in the longitudinal direction X. "Substantially the same position" means that any design misalignment that may occur during diaper manufacturing is within 3 mm. Figure 4(B) shows a state in which no such manufacturing misalignment occurs.

[0072] As shown in Figure 3, the leg elastic body 11 that forms the leg gathers may extend in the lateral direction Y near the side seal 8 and intersect with the fourth elastic body 84, which is an elastic body that forms the waist gathers. In this way, the area where the leg gathers and waist gathers are parallel and intersect makes it easier to pull up the crotch area 9 of diaper 1 to the wearer's crotch when pulling up diaper 1.

[0073] (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.

[0074] The following are examples of the fineness and elongation rates of each of the first to fourth elastic bodies 81 to 84, but the fineness and elongation rates are not limited to those listed here.

[0075] The first elastic material 81 is an elastic material with a fineness of 470 dtex and an elongation ratio of 3.2 times. The second elastic material 82 is an elastic material with a fineness of 310 dtex and an elongation ratio of 2.8 times. The third elastic material 83 is an elastic material with a fineness of 780 dtex and an elongation ratio of 2.7 times. The fourth elastic material 84 is an elastic material with a fineness of 620 dtex and an elongation ratio of 2.5 times.

[0076] [Elastic bodies located in the dorsal extension, upper dorsal portion, and upper ventral portion] The dorsal extension 60, the dorsal upper part 62, and the ventral upper part 32 each have one or more elastic bodies that extend in the lateral direction Y and are expandable in the lateral direction Y. In detail, in the diaper 1 of this embodiment, as shown in Figure 4(B), three first elastic bodies 81a are arranged in the dorsal extension 60. One first elastic body 81b and two second elastic bodies 82a are arranged in the first dorsal upper part 621 of the dorsal upper part 622. In the first dorsal upper part 621, the first elastic body 81b is arranged on the dorsal extension 60 side, and the second elastic bodies 82a are arranged on the second dorsal upper part 622 side of the first elastic body 81b. That is, the first elastic body 81b is on the upper side, and the second elastic bodies 82a are on the lower side. Three second elastic bodies 82b are arranged in the second dorsal upper part 622 of the dorsal upper part 622. Six second elastic bodies 82c are positioned in the ventral upper part 32.

[0077] The first elastic body 81 is an elastic body in which the contraction stress in the lateral direction Y is relatively higher than that of the second elastic body 82. Here, "contraction stress of an elastic body" refers to the contraction stress per elastic body, which can be determined by the measurement method for the contraction stress of an elastic body per unit, as described later.

[0078] As shown in Figures 3 and 4(B), the elastic body positioned in the dorsal extension 60 is the first elastic body 81. The elastic body positioned on the first dorsal upper part 621 includes a first elastic body 81 and a second elastic body 82. The elastic body positioned on the upper part 622 of the second dorsal side is the second elastic body 82. The elastic body located in the ventral upper part 32 is the second elastic body 82. In this way, by arranging the first elastic body 81 and the second elastic body 82, each having a different contraction stress, the relationship of contraction stress can be modified. The dorsal extension portion 60 > first dorsal upper portion 621 > second dorsal upper portion 622 can be configured as follows.

[0079] In diaper 1, two types of elastic bodies (first elastic body 81 and second elastic body 82) with different contraction stresses per elastic body are arranged in the dorsal extension portion 60, the dorsal upper portion 62, and the ventral upper portion 32. In diaper 1, in the region encompassing the dorsal extension portion 60 and the dorsal upper portion 62, the first elastic body 81, which has a relatively high contraction stress, is positioned on the upper side, and the second elastic body 82, which has a relatively low contraction stress, is positioned on the lower side.

[0080] In this embodiment, the shrinkage stress per strand of the first elastic body 81 and the second elastic body 82 is made different by varying the fineness and elongation ratio of the elastic bodies. The first elastic body 81 has a higher fineness than the second elastic body 82. The first elastic body 81 has a higher elongation ratio than the second elastic body 82. Alternatively, the shrinkage stress per strand of the elastic body can be varied by adjusting only one of the fineness or elongation ratio of the elastic bodies. However, from the viewpoint of adjusting the shrinkage stress more easily, it is preferable to adjust both the fineness and elongation ratio (adjusting the first elastic body 81 to have a higher fineness and elongation ratio than the second elastic body 82).

[0081] From the viewpoint of further suppressing bending of the dorsal extension due to abrupt changes in shrinkage stress, the difference in fineness between the first elastic body 81 and the second elastic body 82 is preferably 100 dtex or more and 780 dtex or less, and more preferably 120 dtex or more and 500 dtex or less.

[0082] From the viewpoint of further suppressing bending of the dorsal extension portion due to abrupt changes in shrinkage stress, the difference in elongation ratio between the first elastic body 81 and the second elastic body 82 is preferably 0.2 times or more and 2.0 times or less, and more preferably 0.3 times or more and 1.5 times or less.

[0083] Furthermore, in order to achieve the relationship of shrinkage stress as dorsal extension portion 60 > first dorsal upper portion 621 > second dorsal upper portion 622, in addition to adjusting the fineness and / or elongation rate of the first and second elastic bodies, the arrangement spacing a of the multiple first elastic bodies 81b (see Figure 4(B)) may be configured to be narrower than the arrangement spacing b of the multiple second elastic bodies 82a (see Figure 4(B)).

[0084] Specific examples of the fineness and elongation ratio of the first elastic body 81 and the second elastic body 82 are given below. In the diaper 1 of this embodiment, the first elastic body 81 is an elastic body with a fineness of 470 dtex and an elongation ratio of 3.2 times. The second elastic body 82 is an elastic body with a fineness of 310 dtex and an elongation ratio of 2.8 times.

[0085] As shown in Figure 3, in the region encompassing the dorsal extension 60 and the dorsal upper part 62, the first elastic body 81 is positioned above and below the boundary 103. The only elastic body above the first elastic body 81 located just above the boundary 103 is the first elastic body 81. In the region encompassing the dorsal extension 60 and the dorsal upper part 62, the only elastic body below the first elastic body 81 located just below the boundary 103 is the second elastic body 82.

[0086] From the viewpoint of more effectively suppressing the curling of the dorsal extension portion 60, it is preferable that, as in the diaper 1 of this embodiment, the portion in which the contraction stress of the elastic material changes in the area encompassing the dorsal extension portion 60 and the upper dorsal portion 62 is located below the boundary portion 103. In other words, in diaper 1, the dorsal extension portion 60, which is not joined to the ventral portion and does not form a ring, tends to bend starting from the boundary portion 103, which is the boundary between the dorsal upper portion 62 and the ventral upper portion 32 that are joined to form a ring. Also, in diaper 1, the area between the first region where multiple first elastic bodies 81 are arranged and the second region where multiple second elastic bodies 82 are arranged is a part where the contractile stress of the elastic body changes when viewed along the vertical direction X, and this area tends to bend easily. However, this area does not overlap with the boundary portion 103 and is located below the boundary portion 103. In other words, the first elastic body 81, which has a relatively high contractile stress, is located just below the boundary portion 103, which further suppresses the curling of the dorsal extension portion 60 starting from the boundary portion 103.

[0087] From the viewpoint of further suppressing bending of the dorsal extension portion due to abrupt changes in shrinkage stress, it is preferable that the difference between the shrinkage stress of the first elastic body 81 and the shrinkage stress of the second elastic body 82 per strand be 3 cN / strand or more and 15 cN / strand or less, and more preferably 5 cN / strand or more and 13 cN / strand or less.

[0088] (Method for measuring the lateral Y-force contraction stress per elastic body) In diaper 1, the contraction stress Q in the lateral direction Y for each elastic body arranged parallel to the lateral direction Y is measured as follows.

[0089] ((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 area containing each elastic body to be measured along a straight line parallel to the transverse direction Y (diaper width direction) to obtain a strip or band-shaped sample. When cutting, cut the entire diaper, including the absorbent body 4, not just the ventral part 3 and the dorsal part 6, to remove the absorbent material 40. Alternatively, after removing the absorbent material 40, the ventral part 3 and the dorsal part 6 may be cut into their respective parts. For example, in the diaper 1 of this embodiment, a sample in which the first elastic body 81b located at the uppermost part of the dorsal upper section 62 is positioned was obtained by cutting the diaper 1 along a first cutting line that crosses the center of the vertical X dimension of the spacing between the first elastic body 81a (the first elastic body 81a located at the lowermost part of the dorsal extension 60) located immediately above the first elastic body 81b and the first elastic body 81b, and a second cutting line that crosses the center of the vertical X dimension of the spacing between the second elastic body 82a located immediately below the first elastic body 81b and the first elastic body 81b. The length (mm) in the vertical X and horizontal Y directions of each cut-out sample was recorded. The length (horizontal Y length) (mm) between the side seals 8 of each cut-out sample is measured using the internal dimensions when the sheet constituting the outer casing is not contracted by the elastic material (in other words, when only the ventral part 3 and dorsal part 6 are extended without the elastic material).

[0090] ((Measurement of contraction stress)) The sample is clamped at both ends in the chuck of a tensile testing machine (SHIMIZU "Autograph AG-X"), stretched at a speed of 300 mm / min, and stretched to a length equivalent to 80 (e.g., 280 mm) when the length between the side seals 8 of the dorsal part 6 is set to 100 (e.g., 350 mm). After stretching to a length equivalent to 71 (e.g., 250 mm), the shrinkage stress is measured and defined as the lateral Y shrinkage stress Q per elastic body. 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 main target of wearing the diaper 1 of this embodiment, is approximately 71% of the inner dimensions of the diaper. Note that 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 portions 105) has an inner edge located on the lateral Y-side, and the "internal dimension" refers to the distance between the pair of inner edges. Furthermore, the "internal dimension" refers to the internal dimension when the sheet (thermoplastic sheet 50) constituting the outer casing 5 is not contracted by the elastic body, in other words, when only the ventral and dorsal portions are stretched without the elastic body.

[0091] [Example of a laminated structure for exterior components] As shown in Figure 5, 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 81 to 84 are positioned between the inner layer sheet 52 and the outer layer sheet 51.

[0092] From the viewpoint of increasing the rigidity of the dorsal extension portion 60, it is preferable that the outer casing 5 of the diaper 1 has a folded structure in which one end (the dorsal end) in the vertical direction X is folded back toward the skin-facing side.

[0093] In the back portion 6 of the diaper 1 shown in Figure 5, the laminated outer layer sheet 51 and inner layer sheet 52 are folded back from the back waist end 102 toward the skin-facing side. In the back portion 6, at the folded portion 80, which is the part where the outer covering 5 is folded back toward the skin-facing side, the outer layer sheet 51 is longer in the vertical direction X than the inner layer sheet 52, and the end of the inner layer sheet 52 in the vertical direction X is located within the area of ​​the back extension portion 60. In the back portion 6, where the outer covering 5 is folded back and two layers of the outer covering 5 are laminated, the two layers of the outer covering 5 are bonded together by adhesive 19.

[0094] In the ventral portion 3 of diaper 1, the outer casing 5 has a folded structure in which the other end (ventral end) in the longitudinal direction X is folded back toward the skin-facing side. Specifically, the laminated outer layer sheet 51 and inner layer sheet 52 are folded back toward the skin-facing side from the ventral waist end 101. In the ventral portion 3, in the folded portion 86, which is the part of the outer casing 5 that is folded back toward the skin-facing side, the length of the outer layer sheet 51 in the longitudinal direction X is longer than that of the inner layer sheet 52, and the end of the outer layer sheet 51 in the longitudinal direction X is located further inward in the longitudinal direction X than the end of the inner layer sheet 52 in the longitudinal direction X. In the ventral portion 3, where the outer casing 5 is folded back and two layers of the outer casing 5 are laminated, the two layers of the outer casing 5 are bonded together by adhesive 19.

[0095] In the back extension 60 where the outer casing 5 is laminated in two layers, a portion of the outer casing 5 that faces the folded portion 80 in the thickness direction Z is referred to as the opposing portion 85. As shown in Figure 5, in the folded portion 80, the outer layer sheet 51 and the inner layer sheet 52 have different amounts of folds, with the outer layer sheet 51 having a greater amount of folds than the inner layer sheet 52. Therefore, the folded portion 80 has a two-layer structure region R1 where the two layers of sheets, the outer layer sheet 51 and the inner layer sheet 52, are laminated, and a one-layer structure region R2 consisting only of the outer layer sheet 51. In contrast, the opposing portion 85 is composed of a two-layer structure where the two layers of sheets, the outer layer sheet 51 and the inner layer sheet 52, are laminated. In other words, in the dorsal extension portion 60, the number of layers of sheets constituting the opposing portion 85 (2 sheets in Figure 5) is greater than the number of layers of sheets in the region with the fewest layers of sheets in the folded portion 80 (region R2 in Figure 5) (1 sheet in Figure 5).

[0096] Thus, the outer casing 5 is constructed by laminating multiple sheets and has a folded structure, and it is preferable that the number of laminated sheets constituting the opposing portion 85 in the back extension portion 60 is greater than the number of laminated sheets in the region of the folded portion 80 with the fewest number of laminated sheets.

[0097] This configuration increases the rigidity of the dorsal extension 60, suppressing curling of the dorsal extension 60 while providing a comfortable feel against the skin. In other words, by using a folded structure, the number of layers of sheets in the back extension 60 can be increased compared to the case without folding, thereby increasing the rigidity of the back extension 60 and suppressing curling of the back extension 60. Furthermore, by making the amount of folding of the outer layer sheet 51 and the inner layer sheet 52 different in the back extension 60, and by providing a region in the folded portion 80 with only one layer, it is possible to make it soft and pleasant to the touch.

[0098] In this embodiment, the diaper 1 is shown as an example where the inner layer sheet 52 is also folded back in the dorsal extension portion 60. However, as shown in the modified diaper 1A in Figure 7, the inner layer sheet 52 does not need to be folded back. In other words, in the diaper 1A shown in Figure 7, the folded portion 80 consists only of an area with one layer. Even in this configuration, the dorsal extension portion 60 can be made to have appropriate rigidity to suppress curling and to provide a diaper 1 that is comfortable against the skin.

[0099] It is preferable that at least one of the multiple thermoplastic sheets 50 (outer layer sheet 51 and inner layer sheet 52 in this embodiment) constituting the outer casing 5 is made of spunbond-meltblown-spunbond (SMS) nonwoven fabric. Since SMS nonwoven fabric is a relatively rigid nonwoven fabric, using such a nonwoven fabric to construct the dorsal extension 60 can further suppress curling of the dorsal extension 60.

[0100] [Examples of contraction stress per unit of the first and second elastic bodies] Examples of lateral Y-series contraction stresses for the first and second elastic bodies, measured using the method described above for measuring lateral Y-series contraction stress per elastic body, are given below, but the values ​​are not limited to those given here. The contraction stress of the first elastic body 81 is preferably 11 to 36 cN / strand, and more preferably 14 to 33 cN / strand. The contraction stress of the second elastic body 82 is preferably 3 to 28 cN / strand, and more preferably 6 to 25 cN / strand.

[0101] [Examples of contraction stress in each part] 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 to 65 cN / 10 mm, and more preferably 25 to 60 cN / 10 mm. The shrinkage stress of the dorsal upper portion 62 is preferably 8 to 55 cN / 10 mm, and more preferably 13 to 50 cN / 10 mm. The shrinkage stress of the first dorsal upper portion 621 is preferably 10 to 60 cN / 10 mm, and more preferably 15 to 55 cN / 10 mm. The shrinkage stress of the second dorsal upper portion 622 is preferably 5 to 50 cN / 10 mm, and more preferably 10 to 45 cN / 10 mm. The shrinkage stress in the dorsal intermediate portion 63 is preferably 8 to 55 cN / 10 mm, and more preferably 13 to 40 cN / 10 mm. The shrinkage stress of the lower dorsal portion 64 is preferably 5 to 50 cN / 10 mm, and more preferably 10 to 45 cN / 10 mm. The contractile stress of the ventral upper portion 32 is preferably 5 to 50 cN / 10 mm, and more preferably 10 to 45 cN / 10 mm. The contractile stress in the ventral middle portion 33 is preferably 8 to 55 cN / 10 mm, and more preferably 13 to 40 cN / 10 mm. The contractile stress of the ventral lower portion 34 is preferably 5 to 50 cN / 10 mm, and more preferably 10 to 45 cN / 10 mm.

[0102] <Second Embodiment>

[0103] In the diapers 1 and 1A described above, two types of elastic bodies (first elastic body and second elastic body) with different shrinkage stresses per strand are used as elastic bodies arranged in the region combining the dorsal extension 60 and the dorsal upper part 62, and an example is given where the relationship of shrinkage stress is dorsal extension 60 > first dorsal upper part 621 > second dorsal upper part 622. However, three or more types of elastic bodies with different shrinkage stresses per strand may also be used. In the second embodiment, with reference to Figures 8(A) and (B) showing diaper 1B, an example will be given and explained in which three types of elastic bodies with different shrinkage stresses per strand are used as elastic bodies arranged in the region combining the dorsal extension 60 and the dorsal upper part 62.

[0104] As shown in Figures 8(A) and (B), in diaper 1B, in the region of the dorsal extension 60 and the upper dorsal part 62, two first A elastic bodies 81A, two first B elastic bodies 81B, and five second elastic bodies 82 are intermittently arranged in the longitudinal direction X, sequentially from the waist end side (upper side) to the leg opening side (lower side).

[0105] The first A elastic body 81A, the first B elastic body 81B, and the second elastic body 82 are elastic bodies with different shrinkage stresses per strand, and are shown with different line types in Figures 8(A) and (B). The first A elastic body 81A and the first B elastic body 81B are elastic bodies with higher shrinkage stresses per strand than the second elastic body 82. The first A elastic body 81A is an elastic body with a higher shrinkage stress per strand than the first B elastic body 81B. In diaper 1B, elastic bodies are intermittently arranged in the longitudinal direction X in the region of the dorsal extension 60 and the upper dorsal portion 62, such that the contraction stress per elastic body gradually decreases from the waist end side (upper side) to the leg opening side (lower side).

[0106] The first A elastic body 81A is positioned in the dorsal extension 60. In Figures 8(A) and (B), the first A elastic body 81A is shown by a dashed line. Each of the two first B elastic bodies 81B includes one first B elastic body 81Ba and one first B elastic body 81Bb. The first B elastic body 81Ba is located in the dorsal extension 60, and the first B elastic body 81Bb is located in the first dorsal upper part 621. The first B elastic bodies 81Ba and 81Bb have the same shrinkage stress per unit, differing only in their location. In Figures 8(A) and (B), the first B elastic body 81B is shown by a dotted line. The five second elastic bodies 82 each consist of one second elastic body 82a and four second elastic bodies 82b. The second elastic body 82a is located on the first dorsal upper part 621, and the second elastic bodies 82b are located on the second dorsal upper part 622. The second elastic bodies 82a and 82b differ only in their location, and the contraction stress per body is the same. In Figures 8(A) and (B), the second elastic bodies 82 are shown by long dashed lines.

[0107] Furthermore, six second elastic bodies 82c are positioned in the ventral upper part 32. These second elastic bodies 82c differ from the second elastic bodies 82a only in the location where they are positioned; the contraction stress per body is the same.

[0108] In diaper 1B, by arranging three types of elastic bodies with different contractile stresses in each part as described above, the dorsal extension 60 has a higher contractile stress in the lateral direction Y than the dorsal upper part 62 and the ventral upper part 32, respectively, and the relationship of contractile stress in the lateral direction Y is dorsal extension 60 > first dorsal upper part 621 > second dorsal upper part 622.

[0109] With this configuration, similar to the first embodiment, the shrinkage stress in the dorsal extension portion 60 and the dorsal upper portion 62 does not change abruptly from the top to the bottom, but rather gradually decreases, thereby suppressing curling of the dorsal extension portion 60 and improving wearing comfort. In addition, in the diaper 1B of the second embodiment, in the region where the dorsal extension portion 60 and the dorsal upper portion 62 are located above and below the boundary portion 103, the contraction stress decreases more gradually from the top to the bottom compared to the diaper 1 of the first embodiment, which further suppresses curling of the dorsal extension portion 60.

[0110] <Third Embodiment> Referring to Figure 9, the diaper 1C of the third embodiment will be described below.

[0111] In both the diaper 1C of the third embodiment and the diaper 1D of the fourth embodiment described later, the dorsal extension portion 60 has a higher contractile stress in the lateral direction Y than the dorsal upper portion 62 and the ventral upper portion 32, respectively, and the relationship of contractile stress in the lateral direction Y is dorsal extension portion 60 > first dorsal upper portion 621 > second dorsal upper portion 622. With this configuration, similar to the first embodiment, the shrinkage stress in the dorsal extension portion 60 and the dorsal upper portion 62 does not change abruptly from the top to the bottom, but rather decreases gradually. This suppresses curling of the dorsal extension portion 60 and improves wearing comfort.

[0112] In the first embodiment described above, as shown in Figure 4(A), a diaper 1 was used as an example in which, in the ventral intermediate portion 33 and the dorsal intermediate portion 63 located near the ilium, the dorsal intermediate portion 63 has an elastic body-free region where there is no elastic body in the same position in the longitudinal direction X as the elastic body located in the ventral intermediate portion 33. In contrast, as shown in Figure 9, in the diaper 1C of this embodiment (third embodiment), the multiple (four in this case) third elastic bodies 83b arranged in the ventral middle portion 33 and the multiple (four in this case) third elastic bodies 83a arranged in the dorsal middle portion 63 may be in substantially the same position in the longitudinal direction X.

[0113] In the worn state of diaper 1C, as shown in the first embodiment of diaper 1 in Figure 2(A), the entire side seal 8 and the side reinforcement portion 105 continuous therewith have 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. In the worn state of diaper 1C, having the side seal 8 in a sloped substantially straight shape allows for a neat appearance. Furthermore, in diaper 1C, the same number of elastic bodies with the same fineness and elongation rate are arranged in the ventral middle portion 33 and the dorsal middle portion 63, respectively. This increases the stress near the iliac crest on both the ventral and dorsal sides when worn, and even when the child moves around vigorously after wearing, the diaper catches on the iliac crest, preventing the diaper from slipping down on the ventral and dorsal sides, thereby effectively suppressing leakage of soft stool from the dorsal side. The same applies to diaper 1D of the fourth embodiment.

[0114] As shown in Figure 9, in the dorsal portion 6 of diaper 1C, three first elastic bodies 81a 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 81b, one second elastic body 82a, and two second elastic bodies 82b. In the first upper dorsal portion 621 of the upper dorsal portion 622, one first elastic body 81b and one second elastic body 82a are arranged, and in the second upper dorsal portion 622, two second elastic bodies 82b are arranged. In the middle dorsal portion 63, four third elastic bodies 83a are arranged. In the lower dorsal portion 64, four fourth elastic bodies 84a are arranged. In the ventral portion 3 of diaper 1C, a total of five second elastic bodies are arranged in the upper ventral portion 32: one second elastic body 82d and four second elastic bodies 82c. Four third elastic bodies 83b are arranged in the middle ventral portion 33. Four fourth elastic bodies 84b 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 fourth embodiment described later.

[0115] As shown in Figure 9, in the ventral portion 3 of diaper 1C, the outer casing 5 is folded back towards the skin-facing side, and the upper ventral portion 32 is constructed by laminating two layers of the outer casing 5. In the ventral portion 3, the portion of the outer casing 5 that is folded back towards the skin-facing side is called the folded portion 86, and the portion of the outer casing 5 that faces the folded portion 86 in the thickness direction Z is called the opposing portion 87. In diaper 1C, four second elastic bodies 82c are arranged in the region of the upper ventral portion 32 of the opposing portion 87, and one second elastic body 82d is arranged in the region of the upper ventral portion 32 of the folded portion 86. In the example shown in Figure 9, the second elastic body 82d is arranged in the upper region when the upper ventral portion 32 is divided in the vertical direction X.

[0116] As shown in Figure 9, in the dorsal portion 6 of diaper 1C, the outer casing is folded back toward the skin-facing side, and the dorsal extension portion 60 is constructed by laminating two layers of the outer casing 5. In the dorsal portion 6, the portion of the outer casing 5 that is folded back toward the skin-facing side is called the folded portion 80, and the portion of the outer casing 5 that faces the folded portion 80 in the thickness direction Z is called the opposing portion 85. In diaper 1C, as with diaper 1 described above, three first elastic bodies 81a are arranged in the region of the dorsal extension portion 60 of the opposing portion 85, and no elastic bodies are arranged in the folded portion 80.

[0117] The second elastic bodies 82a, 82b, 82c, and 82d differ only in their placement and position, but each has the same contraction stress.

[0118] As with diaper 1C, an elastic material may be placed in the folded portion 86 of the ventral portion 3, allowing the contraction stress to be different in the upper and lower regions when the ventral upper portion 32 is divided in the vertical direction X, making it easier to adjust the contraction stress distribution in the outer casing 5.

[0119] In the example of diaper 1C shown in Figure 9, the upper ventral portion 32 has two elastic bodies (82c, 82d) arranged in the thickness direction Z in the upper region of the ventral portion 32, and one elastic body (82c) 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.

[0120] As with diaper 1C, the placement of an elastic material in the folded portion 86 of the abdominal side 3 can improve wearing comfort. In other words, the contractile 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 materials. Therefore, by placing an elastic material in the folded portion 86 of the ventral part 3 and increasing the number of materials, the contractile stress near the ventral waist end 101 can be increased more easily. This makes it easier for the lower end 105b of the side reinforcement (upper end 8a of the side seal) to face ventrally when worn, and makes it easier for the upper end 105a of the side reinforcement to be positioned more dorsally than the lower end 105b of the side reinforcement. As a result, when wearing the diaper, for example when the wearer is lying on their side, the highly rigid side reinforcement 105 is less likely to come into contact with the side of the wearer's waist, reducing discomfort and improving wearing comfort.

[0121] 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 81a and the first elastic body 81b 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 82a, 82b, 82c, and 82d 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 83a and the third elastic body 83b have the same fineness and elongation ratio, differing only in their placement; the fineness is 780 dtex and the elongation ratio is 2.7 times. The fourth elastic body 84a and the fourth elastic body 84b 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.

[0122] As shown in Figure 9, in the dorsal portion 6, four first elastic bodies (three first elastic bodies 81a and one first elastic body 81b), three second elastic bodies (one second elastic body 82a and two second elastic bodies 82b), and four third elastic bodies 83a 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 84a and the spacing between the two lower fourth elastic bodies 84a is the same, and their pitch is, for example, 5.5 mm. In the elastic bodies arranged in a manner other than the folded portion 86 of the ventral portion 3, the four second elastic bodies 82c and the four third elastic bodies 83b 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 84b and the spacing between the two lower fourth elastic bodies 84b are the same, and their pitch is, for example, 5.5 mm.

[0123] Furthermore, as shown in diaper 1C in Figure 9, 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 ventral waist end 101. This prevents leakage due to rolling up and suppresses discomfort caused by rolling up. The same applies to the diaper 1D of the fourth embodiment described later.

[0124] <Fourth Embodiment> Referring to Figure 10, the diaper 1D of this embodiment (fourth embodiment) will be described below.

[0125] In the fourth embodiment, diaper 1D, similar to diaper 1C in the third embodiment, has multiple (in this case, four) third elastic bodies 83b arranged in the ventral middle section 33 and multiple (in this case, four) third elastic bodies 83a arranged in the dorsal middle section 63, all located in the same position in the longitudinal direction X. In the diaper 1D when worn, as shown in the first embodiment of diaper 1 in Figure 2(A), the entire side seal 8 and the side reinforcement portion 105 continuous therewith have a substantially straight shape that is inclined with respect to the vertical direction X, from top to bottom and from the dorsal side to the ventral side.

[0126] As shown in Figure 10, in the dorsal portion 6 of the diaper 1D, two first elastic bodies 81a and one first elastic body 81c 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 81b, one second elastic body 82a, and two second elastic bodies 82b. In the first upper dorsal portion 621 of the upper dorsal portion 622, one first elastic body 81b and one second elastic body 82a are arranged, and in the second upper dorsal portion 622, two second elastic bodies 82b are arranged. In the middle dorsal portion 63, four third elastic bodies 83a are arranged. In the lower dorsal portion 64, four fourth elastic bodies 84a are arranged. The ventral portion 3 of diaper 1D has the same configuration as the ventral portion 3 of diaper 1C in the third embodiment. 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.

[0127] As shown in Figure 10, the ventral portion 3 of diaper 1D, like diaper 1C, has a folded portion 86 and an opposing portion 87. Four second elastic bodies 82c are arranged in the region of the upper ventral portion 32 of the opposing portion 87, and one second elastic body 82d is arranged in the region of the upper ventral portion 32 of the folded portion 86. In the example shown in Figure 10, the second elastic body 82d is arranged in the upper region when the upper ventral portion 32 is divided in the vertical direction X.

[0128] As shown in Figure 10, in the dorsal portion 6 of the diaper 1D, the outer casing is folded back toward the skin-facing side, and the dorsal extension portion 60 is constructed by laminating two layers of the outer casing 5. In the diaper 1D, in the dorsal portion 6, one first elastic body 81c is placed in the folded portion 80, which is the part of the outer casing 5 that is folded back toward the skin-facing side, and two first elastic bodies 81a are placed in the region of the dorsal extension portion 60 of the opposing portion 85, which is the part of the outer casing 5 that faces the folded portion 80 in the thickness direction Z.

[0129] The first elastic bodies 81a, 81b, and 81c differ only in their placement and position, but each has the same shrinkage stress. The second elastic bodies 82a, 82b, 82c, and 82d differ only in their placement and position, but each has the same shrinkage stress.

[0130] As with diaper 1D, elastic materials may be placed in the folded portions of both the dorsal portion 6 and the ventral portion 3. This allows for different contraction stresses in the upper ventral portion 32 and the dorsal extension portion 60 when the vertical direction X is divided into two equal parts, making it easier to adjust the contraction stress distribution in the outer casing 5.

[0131] In the example of diaper 1D shown in Figure 10, the ventral upper portion 32 has two elastic bodies (82c, 82d) arranged in the thickness direction Z in the upper region of the ventral upper portion 32, and one elastic body (82c) arranged in the thickness direction Z in the lower region of the ventral upper portion 32, resulting in a higher contraction stress in the lateral direction Y in the upper region of the ventral upper portion 32 than in the lower region. Furthermore, in diaper 1D, the dorsal extension portion 60 has two elastic bodies (81a, 81c) arranged in the thickness direction Z in the upper region of the dorsal extension portion 60, and one elastic body (81a) arranged in the thickness direction Z in the lower region of the dorsal extension portion 60, resulting in a higher contraction stress in the lateral direction Y in the upper region of the dorsal extension portion 60 than in the lower region.

[0132] As with diaper 1D, elastic material can be placed in the folded portions 80 and 86 of both the ventral portion 3 and the dorsal portion 6 to further improve wearing comfort. In other words, 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 materials. Therefore, by placing an elastic material in the folded portion 86 of the ventral part 3 and increasing the number of materials, the contraction stress near the ventral waist end 101 can be increased more easily. Similarly, by placing an elastic material in the folded portion 80 of the dorsal part 6 and increasing the number of materials, the contraction stress near the dorsal waist end 102 can be increased more easily. As a result, when worn, the position of the lower end 105b of the side reinforcement (upper end 8a of the side seal) tends to face ventrally, and the position of the upper end 105a of the side reinforcement tends to face dorsally, making it easier for the upper end 105a of the side reinforcement to be positioned further dorsally than the lower end 105b of the side reinforcement. As a result, discomfort when wearing the garment is reduced, and wearing comfort can be improved.

[0133] 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 81a, 81b, and 81c 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 82a, 82b, 82c, and 82d 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 83a and the third elastic body 83b have the same fineness and elongation ratio, differing only in their placement; the fineness is 780 dtex and the elongation ratio is 2.7 times. The fourth elastic body 84a and the fourth elastic body 84b 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.

[0134] As shown in Figure 10, in the elastic bodies arranged in a manner other than the folded portion 80 of the back portion 6, two first elastic bodies 81a, one first elastic body 81b, three second elastic bodies (one second elastic body 82a, two second elastic bodies 82b), and four third elastic bodies 83a are intermittently arranged at equal intervals in the vertical direction X (for example, with a pitch of 5.5 mm). In the back portion 6, the spacing between the two upper fourth elastic bodies 84a and the spacing between the two lower fourth elastic bodies 84a is the same, and for example, their pitch is 5.5 mm. In the elastic bodies arranged in a manner other than the folded portion 86 of the ventral portion 3, the four second elastic bodies 82c and the four third elastic bodies 83b 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 84b and the spacing between the two lower fourth elastic bodies 84b are the same, and their pitch is, for example, 5.5 mm.

[0135] Furthermore, as shown in Figure 10, in diaper 1D, similar to diaper 1C, 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.

[0136] In the third embodiment of diaper 1C and the fourth embodiment of diaper 1D, similar to diaper 1, a first elastic body 81 with relatively high shrinkage stress is provided in the dorsal extension portion 60. In the first dorsal upper portion 621, a first elastic body 81 is provided on the dorsal extension portion 60 side, and a second elastic body 82 is provided on the second dorsal upper portion 622 side of the first elastic body 81 and has lower shrinkage stress than the first elastic body 81. Only the second elastic body 82 is provided in the second dorsal upper portion 622. The first elastic body 81 has a higher fineness and elongation ratio than the second elastic body 82. By arranging the elastic material in this manner, the relationship of contraction stress in the lateral direction Y for diapers 1C and 1D is as follows: dorsal extension 60 > first dorsal upper part 621 > second dorsal upper part 622.

[0137] <Fifth Embodiment> In the first embodiment of diaper 1 described above, an example was given in which the outer casing 5 has a configuration in which the ventral portion 3, the dorsal portion 6, and the crotch portion 9 are integrated, but it is not limited to this. For example, as in the pant-type diaper 1E shown in Figure 11, the outer casing may be divided into a ventral portion 3E and a dorsal portion 6E. Diaper 1E consists of a rectangular ventral portion 3E positioned on the wearer's ventral side, a rectangular dorsal portion 6E positioned on the wearer's dorsal side, and a crotch portion 9E including an absorbent body fixed across the ventral portion 3E and the dorsal portion 6E. The crotch portion 9E has a crotch outer casing 90 and an absorbent body (including a surface sheet, an absorbent body, and a back sheet). The crotch outer casing 90 together with the ventral portion 3E and the dorsal portion 6E constitutes the outer casing of diaper 1E. The dorsal portion 6C has a dorsal extension 60. The side edges of the dorsal portion 6E and the side edges of the ventral portion 3E are joined together to form a pair of side seals 8. The dorsal portion 6E and the ventral portion 3E each include a plurality of elastic bodies 81-84 that extend in the transverse direction Y, are intermittently arranged in the longitudinal direction X, and are expandable and contractible in the transverse direction Y.

[0138] In diaper 1E, as with diaper 1, the dorsal extension 60 has a higher lateral Y contraction stress than the dorsal upper part 62 and the ventral upper part 32, and the dorsal extension 60 has a higher lateral Y contraction stress than both the dorsal upper part 62 and the ventral upper part 32, and the relationship of lateral Y contraction stress is dorsal extension 60 > first dorsal upper part 621 > second dorsal upper part 622.

[0139] With this configuration, similar to the first embodiment, the dorsal extension 60 and the dorsal upper part 62 are configured so that the contractile stress does not change abruptly from the top to the bottom, but gradually decreases, thereby suppressing the curling of the dorsal extension 60 and improving wearing comfort. In diaper 1E, similar to diaper 1, the contractile stress of each part can be adjusted by adjusting the contractile stress of each elastic body 81 and 82 placed in the ventral part 3E and the dorsal part 6E, respectively.

[0140] 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 invention.

[0141] For example, the pant-type absorbent article according to the present invention does not have to be a disposable diaper for infants, but may be a disposable diaper for adults or children, for example. Furthermore, the pant-type absorbent 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 pant-type absorbent articles include pant-type sanitary napkins.

[0142] 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, It has a pair of side seals, the lateral edge of the ventral portion and the lateral edge of the dorsal portion being joined together, 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 side seal has an upper end and a lower end that are opposite to each other in the vertical direction. The rear body portion has a rear upper portion which is the region closest to the upper end of the side seal when the rear body portion is divided into three equal parts in the vertical direction, 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 has a higher lateral contraction stress than the dorsal upper part and the ventral upper part. When the upper dorsal portion is divided vertically into two equal parts, a first upper dorsal portion and a second upper dorsal portion, which are arranged sequentially from the upper end of the side seal towards the lower end of the side seal, the dorsal extension portion has a higher lateral shrinkage stress than the first upper dorsal portion, and the first upper dorsal portion has a higher lateral shrinkage stress than the second upper dorsal portion. Absorbent pants. <2> The dorsal extension, the first dorsal upper part, and the second dorsal upper part each have one or more elastic bodies that extend laterally and are expandable in the later direction, The elastic body disposed in the dorsal extension is a first elastic body with relatively high lateral contraction stress, The elastic body disposed on the first dorsal upper part includes the first elastic body disposed on the dorsal extension side and the second elastic body disposed on the second dorsal upper part side than the first elastic body and having a lower lateral contraction stress than the first elastic body. The elastic body positioned on the upper dorsal side of the second elastic body is the second elastic body. The aforementioned <1> Absorbent pant-type articles as described above. <3> The first elastic body has a higher fineness than the second elastic body. The aforementioned <2> Absorbent pant-type articles as described above. <4> The difference in fineness between the first elastic material and the second elastic material is 100 dtex or more and 780 dtex or less. The aforementioned <3> Absorbent pant-type articles as described above. <5> The first elastic material has a higher elongation rate than the second elastic material. The aforementioned <2> ~ <4> A pant-type absorbent article described in any one of the following. <6> The difference in elongation ratio between the first elastic body and the second elastic body is 0.2 times or more and 2 times or less. The aforementioned <5> Absorbent pant-type articles as described above. <7> Multiple first elastic bodies and multiple second elastic bodies are intermittently arranged in the longitudinal direction on the dorsal extension, the first dorsal upper part, and the second dorsal upper part. The spacing between the multiple first elastic bodies is narrower than the spacing between the multiple second elastic bodies. The aforementioned <2> ~ <6> A pant-type absorbent article described in any one of the following. <8> The difference in contraction stress between the first elastic body and the second elastic body is 3 cN / strand or more and 15 cN / strand or less. The aforementioned <2> ~ <7> A pant-type absorbent article described in any one of the following. <9> The contraction stress of the first elastic body is 11 to 36 cN / strand, and the contraction stress of the second elastic body is 3 to 28 cN / strand. The aforementioned <2> ~ <8> A pant-type absorbent article described in any one of the following. <10> The multiple elastic bodies located on the dorsal extension and the upper dorsal portion are intermittently arranged in the longitudinal direction, and the multiple elastic bodies are arranged such that the contraction stress per elastic body gradually decreases from the waist end side toward the leg opening side. The aforementioned <2> ~ <9> A pant-type absorbent article described in any one of the following. <11> The first elastic body is composed of a first A elastic body and a first B elastic body having a lower lateral contraction stress than the first A elastic body. The first elastic body A is located closer to the waist end than the first elastic body B. The elastic bodies arranged in the dorsal extension are the 1A elastic body and the 1B elastic body, The elastic body positioned on the upper part of the first dorsal side is the first B elastic body and the second elastic body. The aforementioned <10> Absorbent pant-type articles as described above. <12> The first elastic body and the second elastic body are arranged in the region formed by combining the dorsal extension and the dorsal upper part. In the region comprising the dorsal extension and the dorsal upper part, the first elastic body is positioned above and below the boundary portion, which is the boundary between the dorsal extension and the dorsal main body, and the only elastic body below the first elastic body located immediately below the boundary portion is the second elastic body. The aforementioned <2> ~ <11> A pant-type absorbent article described in any one of the following. <13> The difference between the lateral shrinkage stress of the dorsal extension and the lateral shrinkage stress of the upper dorsal portion is 5 cN / 10 mm or more and 18 cN / 10 mm or less. The aforementioned <1> ~ <12> A pant-type absorbent article described in any one of the following. <14> The difference between the lateral contraction stress of the dorsal extension and the lateral contraction stress of the ventral upper portion is 9 cN / 10 mm or more and 22 cN / 10 mm or less. The aforementioned <1> ~ <13> A pant-type absorbent article described in any one of the following. <15> The exterior body is constructed by laminating multiple sheets, The dorsal extension comprises a folded portion in which one end of the outer casing in the vertical direction is folded back toward the skin-facing surface, and a part of the outer casing that faces the folded portion in the thickness direction. The number of layers of the sheets constituting the opposing portion is greater than the number of layers of the sheets in the region with the fewest layers of sheets in the folded portion. The aforementioned <1> ~ <14> A pant-type absorbent article described in any one of the following. <16> The exterior body is constructed by laminating multiple sheets, At least one of the multiple sheets constituting the exterior is a spunbond-meltblown-spunbond nonwoven fabric. The aforementioned <1> ~ <15> A pant-type absorbent article described in any one of the following. <17> 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 has The aforementioned <1> ~ <16> A pant-type absorbent article described in any one of the following. <18> The pair of side reinforcing portions are continuous with the pair of side seals. The aforementioned <17> Absorbent pant-type articles as described above. <19> The side reinforcement portion includes a plurality of sealing portions formed by pressurizing means and / or heating means. The aforementioned <17> or the above <18> Absorbent pant-type articles as described above. <20> The rear body portion has a rear lower portion which is the region closest to the lower end of the side seal when the rear body portion is divided into three equal parts in the vertical direction, The ventral portion has a ventral lower portion that is in the same position as the dorsal lower portion in the longitudinal direction, In the region where the dorsal lower part and the ventral lower part are connected in a ring shape, the contractile stress is equal on the dorsal and ventral sides. The aforementioned <1> ~ <19> A pant-type absorbent article described in any one of the following. <21> The aforementioned back body portion is divided into three equal parts in the vertical direction, and comprises the upper back portion, the middle back portion, and the lower back portion, which are arranged in order from the waist opening toward the leg opening. The shrinkage stress of the dorsal extension is 20-65 cN / 10 mm. The contraction stress in the upper dorsal portion is 8-55 cN / 10 mm. The contraction stress of the first dorsal upper portion is 10-60 cN / 10 mm. The contraction stress of the second dorsal upper portion is 5-50 cN / 10 mm. The shrinkage stress in the dorsal intermediate portion is 8-55 cN / 10 mm. The contraction stress in the lower dorsal portion is 5-50 cN / 10 mm. The aforementioned <1> ~ <20> A pant-type absorbent article described in any one of the following. <22> The ventral portion is divided into three equal parts in the longitudinal direction, and comprises the upper ventral portion, the middle ventral portion, and the lower ventral portion, arranged in order from the waist opening toward the leg opening. The contractile stress in the ventral upper portion is 5-50 cN / 10 mm. The contractile stress in the ventral middle portion is 8-55 cN / 10 mm. The contractile stress in the ventral lower portion is 5-50 cN / 10 mm. The aforementioned <1> ~ <21> A pant-type absorbent article described in any one of the following. <23> The exterior body is constructed by laminating an inner layer sheet and an outer layer sheet. At the back waist end, one of the vertical ends of the outer casing is folded back toward the skin-facing side, and no elastic material is placed between the inner layer sheet and the outer layer sheet of the folded portion of the back side of the outer casing, At the ventral waist end, the other end of the outer covering in the longitudinal direction is folded back toward the skin-facing side, and an elastic body is placed between the inner layer sheet and the outer layer sheet of the folded portion of the ventral side of the outer covering, which is the folded portion. In the ventral upper region, when the ventral upper region is divided into two equal parts in the longitudinal direction, the upper region has a higher transverse contraction stress than the lower region. The aforementioned <1> ~ <22> A pant-type absorbent article described in any one of the following. <24> The exterior body is constructed by laminating an inner layer sheet and an outer layer sheet. At the back waist end, one of the vertical ends of the outer body is folded back toward the skin-facing side, and an elastic body is placed between the inner layer sheet and the outer layer sheet of the folded portion of the back side of the outer body, which is the folded portion of the outer body. At the ventral waist end, the other end of the outer covering in the longitudinal direction is folded back toward the skin-facing side, and an elastic body is placed between the inner layer sheet and the outer layer sheet of the folded portion of the ventral side of the outer covering, which is the folded portion. In the ventral upper portion, when the ventral upper portion is divided into two equal parts in the longitudinal direction, the upper region has a higher transverse contraction stress than the lower region. In the dorsal extension, when the dorsal extension is divided into two equal parts in the vertical direction, the upper region has a higher lateral shrinkage stress than the lower region. The aforementioned <1> ~ <22> A pant-type absorbent article described in any one of the following. <25> 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> ~ <24> A pant-type absorbent article described in any one of the following. <26> 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> ~ <25> A pant-type absorbent article described in any one of the following. [Explanation of Symbols]

[0143] 1, 1A, 1B, 1C, 1D, 1E... Absorbent pants (disposable diapers, diapers) 1W…Waist opening 1L... Leg opening 3...Ventral part 4… Absorbent body 5…Exterior 6...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 621…upper part of the first dorsal side 622…Second upper dorsal side 101...Ventral waist end 102...Rear waist end

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, It has a pair of side seals, the lateral edge of the ventral portion and the lateral edge of the dorsal portion being joined together, 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 side seal has an upper end and a lower end that are opposite to each other in the vertical direction. The rear body portion has a rear upper portion which is the region closest to the upper end of the side seal when the rear body portion is divided into three equal parts in the vertical direction, 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 has a higher lateral contraction stress than the dorsal upper part and the ventral upper part. When the upper dorsal portion is divided vertically into two equal parts, a first upper dorsal portion and a second upper dorsal portion, arranged sequentially from the upper end of the side seal towards the lower end of the side seal, the dorsal extension portion has a higher lateral shrinkage stress than the first upper dorsal portion, and the first upper dorsal portion has a higher lateral shrinkage stress than the second upper dorsal portion. Absorbent pants.

2. The dorsal extension, the first dorsal upper part, and the second dorsal upper part each have one or more elastic bodies that extend laterally and are expandable in the later direction, The elastic body arranged in the dorsal extension is a first elastic body with relatively high lateral contraction stress, The elastic body positioned on the first dorsal upper portion includes the first elastic body positioned on the dorsal extension side and the second elastic body positioned on the second dorsal upper portion side of the first elastic body and having a lower lateral contraction stress than the first elastic body. The elastic body positioned on the upper part of the second dorsal side is the second elastic body. The pant-type absorbent article according to claim 1.

3. The first elastic body has a higher fineness than the second elastic body. The pant-type absorbent article according to claim 2.

4. The first elastic body has a higher elongation rate than the second elastic body. The pant-type absorbent article according to claim 2 or 3.

5. Multiple first elastic bodies and multiple second elastic bodies are intermittently arranged in the longitudinal direction on the dorsal extension, the first dorsal upper part, and the second dorsal upper part. The spacing between the multiple first elastic bodies is narrower than the spacing between the multiple second elastic bodies. The pant-type absorbent article according to claim 2 or 3.

6. The difference between the lateral shrinkage stress of the dorsal extension and the lateral shrinkage stress of the upper dorsal portion is 5 cN / 10 mm or more and 18 cN / 10 mm or less. The pant-type absorbent article according to claim 2.

7. The difference between the lateral contraction stress of the dorsal extension and the lateral contraction stress of the ventral upper portion is 9 cN / 10 mm or more and 22 cN / 10 mm or less. The pant-type absorbent article according to claim 6.

8. The difference in contraction stress between the first elastic body and the second elastic body is 3 cN / strand or more and 15 cN / strand or less. The pant-type absorbent article according to claim 2.

9. The difference in fineness between the first elastic body and the second elastic body is 100 dtex or more and 780 dtex or less. The pant-type absorbent article according to claim 3.

10. The difference in elongation ratio between the first elastic body and the second elastic body is 0.2 times or more and 2 times or less. The pant-type absorbent article according to claim 4.

11. The multiple elastic bodies located on the dorsal extension and the upper dorsal portion are intermittently arranged in the longitudinal direction, and the multiple elastic bodies are arranged such that the contraction stress per elastic body gradually decreases from the waist end side toward the leg opening side. The pant-type absorbent article according to claim 2.

12. The first elastic body is composed of a first A elastic body and a first B elastic body having a lower lateral contraction stress than the first A elastic body. The first A elastic body is located closer to the waist end than the first B elastic body. The elastic bodies arranged in the dorsal extension are the 1A elastic body and the 1B elastic body, The elastic body positioned on the upper part of the first dorsal side is the first B elastic body and the second elastic body. The pant-type absorbent article according to claim 11.

13. The exterior body is constructed by laminating multiple sheets, The dorsal extension comprises a folded portion in which one end of the outer casing in the vertical direction is folded back toward the skin-facing surface, and a part of the outer casing that faces the folded portion in the thickness direction. The number of layers of the sheets constituting the opposing portion is greater than the number of layers of the sheets in the region with the fewest layers of sheets in the folded portion. The pant-type absorbent article according to claim 1 or 2.

14. The exterior body is constructed by laminating multiple sheets, At least one of the multiple sheets constituting the exterior is a spunbond-meltblown-spunbond nonwoven fabric. The pant-type absorbent article according to claim 1 or 2.

15. 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 has The pant-type absorbent article according to claim 1 or 2.

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