Pants-type absorbent article

Abstract

This pant-type absorbent article (1) comprises: an absorbent main body (10); and a waistline member (20) having hydrophobic nonwoven fabrics (31, 41) and hydrophilic nonwoven fabrics (32, 42) which are provided further to the non-skin side than the hydrophobic nonwoven fabrics (31, 41) and have higher hydrophilicity than the hydrophobic nonwoven fabrics (31, 41), wherein, in a pants internal temperature measurement experiment using a sweating mannequin provided with a temperature sensor at a predetermined position, when a first temperature is the temperature measured at the predetermined position while the pant-type absorbent article (1) is worn on the sweating mannequin so as to cover the predetermined position, and when a second temperature is the temperature measured at the predetermined position while the predetermined position is not covered, the hydrophilic nonwoven fabrics (32, 42) are disposed on the waistline member (20) so that the difference between the first temperature and the second temperature is no greater than 1.5°C after 60 minutes elapse from the start of the power supply to the sweating mannequin.

Description

[Technical Field]

[0001] The present invention relates to a pants-type absorbent article. [Background technology]

[0002] Conventionally, in absorbent articles such as pants-type disposable diapers, a technique for increasing water absorbency by using a hydrophilic sheet in part of a waistband member has been known. For example, Patent Document 1 discloses a disposable diaper in which a skin-side sheet 5 located on the skin side of a wearer and an outer-layer sheet 4 located on the non-skin side use sheet members such as nonwoven fabrics containing hydrophilic fibers. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2017-113186 Summary of the Invention [Problem to be solved by the invention]

[0004] In general, pants-type diapers made of nonwoven fabric such as those described in Patent Document 1 tend to trap heat between the diaper and the wearer's body compared to cloth underwear, etc., and when worn, the internal temperature rises, which could cause the inside of the pants-type diaper (absorbent article) to become stuffy and cause discomfort to the wearer.

[0005] Furthermore, diapers using hydrophilic sheet members can easily absorb moisture such as sweat from the wearer's skin when worn. However, even if the hydrophilic sheet absorbs moisture from the wearer's skin, there is a problem in that the moisture retained in the hydrophilic sheet is difficult to evaporate. In this case, the contact of the moist hydrophilic sheet with the wearer's skin may cause discomfort to the wearer.

[0006] The present invention has been made in view of the above-mentioned conventional problems, and its object is to provide a pants-type absorbent article that is less likely to cause discomfort to the wearer. More specifically, the first object is to provide a pants-type absorbent article that is less likely to cause an increase in internal temperature when worn, and the second object is to provide a pants-type absorbent article that can absorb moisture from the wearer's skin and efficiently evaporate the absorbed moisture into the atmosphere. [Means for solving the problem]

[0007] The main invention for achieving the first object is a pants-type absorbent article comprising an absorbent main body, a hydrophobic nonwoven fabric, and a waistband member having a hydrophilic nonwoven fabric that is located closer to the skin than the hydrophobic nonwoven fabric and has higher hydrophilicity than the hydrophobic nonwoven fabric, wherein in an experiment to measure temperature inside pants using a sweating mannequin equipped with a temperature sensor at a predetermined position, when the sweating mannequin is made to wear the pants-type absorbent article so that the temperature measured at the predetermined position is covered by the pants-type absorbent article, the temperature measured at the predetermined position is defined as a first temperature, and the temperature measured at the predetermined position is defined as a second temperature, the difference between the first temperature 60 minutes after the start of supplying power to the sweating mannequin and the second temperature 60 minutes after the start of supplying power to the sweating mannequin is 1.5°C or less.

[0008] The main invention for achieving the second object is: having an up-down direction, a left-right direction, and a front-rear direction which intersect with one another, A pants-type absorbent article having a liquid-absorbing absorbent main body and a waistband member provided on a side closer to the wearer's skin than the absorbent main body, In at least a part of the region of the waistband member, a hydrophobic nonwoven fabric placed closest to the skin; a hydrophilic nonwoven fabric laminated adjacent to the non-skin side of the hydrophobic nonwoven fabric and having higher hydrophilicity than the hydrophobic nonwoven fabric; an elastic member provided between the hydrophobic nonwoven fabric and the hydrophilic nonwoven fabric, the elastic member stretching in the left-right direction; of It has The average fiber density of the hydrophobic nonwoven fabric is higher than the average fiber density of the hydrophilic nonwoven fabric. The pants-type absorbent article is characterized by the above. Other features of the present invention will become apparent from the description of this specification and the accompanying drawings. [Effects of the Invention]

[0009] The effect of the present invention in relation to the first problem is to provide a pants-type absorbent article in which the internal temperature is less likely to rise when worn.

[0010] The effect of the present invention in achieving the second objective is to provide a pants-type absorbent article that can absorb moisture from the wearer's skin and efficiently evaporate the absorbed moisture into the atmosphere. [Brief explanation of the drawings]

[0011] [Figure 1] FIG. 1 is a schematic perspective view of a diaper 1. [Figure 2] 1 is a plan view of the diaper 1 in an unfolded and stretched state. [Figure 3] FIG. 3 is a schematic cross-sectional view taken along line AA in FIG. 2. [Figure 4] FIG. 4A is a plan view of the absorbent body 10, and FIG. 4B is a schematic cross-sectional view of the absorbent body 10. As shown in FIG. [Figure 5] 5A and 5B are diagrams illustrating the cross-sectional shape of the front waistband 30 when the diaper 1 is worn. [Figure 6] FIG. 5B is an enlarged cross-sectional view of a region X in FIG. 5A. [Figure 7] FIG. 5C is an enlarged cross-sectional view of region Y in FIG. 5B. [Figure 8] 8 is an enlarged cross-sectional view of a region Y in FIG. 5B, showing the state after a predetermined time has elapsed since the state in FIG. 7. FIG. [Figure 9] 10 is a diagram illustrating evaporation of moisture when apertures 32h are provided in the non-skin side sheet 32. FIG. [Figure 10] 10A and 10B are diagrams illustrating a method for attaching the waistline elastic members 35 to the front waistline portion 30 using the welded portions 60. FIG. [Figure 11] FIG. 11A is a diagram illustrating the temperature measurement positions on the front side (ventral side) of the sweating manikin, and FIG. 11B is a diagram illustrating the temperature measurement positions on the back side (dorsal side) of the sweating manikin. [Figure 12] 12A and 12B are diagrams showing the results of measurements of the temperatures inside pants of a plurality of types of pants-type wearing articles. [Figure 13] Fig. 13A is a plan view of the diaper 2 in an unfolded and stretched state, and Fig. 13B is a schematic cross-sectional view taken along line BB in Fig. 13A. [Figure 14] Fig. 14A is a plan view of the diaper 3 in an unfolded and stretched state, and Fig. 14B is a schematic cross-sectional view taken along line CC in Fig. 14A. DETAILED DESCRIPTION OF THE INVENTION

[0012] At least the following matters will become clear from the description of this specification and the accompanying drawings. A pants-type absorbent article comprising an absorbent main body, a hydrophobic nonwoven fabric, and a waistband member having a hydrophilic nonwoven fabric that is located closer to the skin than the hydrophobic nonwoven fabric and has higher hydrophilicity than the hydrophobic nonwoven fabric, wherein in an experiment to measure temperature inside pants using a sweating mannequin equipped with a temperature sensor at a predetermined position, when the sweating mannequin is made to wear the pants-type absorbent article so that the temperature measured at the predetermined position is covered by the pants-type absorbent article, the temperature measured at the predetermined position is defined as a first temperature, and the temperature measured at the predetermined position is defined as a second temperature, the difference between the first temperature 60 minutes after the start of supplying power to the sweating mannequin and the second temperature 60 minutes after the start of supplying power to the sweating mannequin is 1.5°C or less.

[0013] According to such a pants-type absorbent article, the moisture absorbed by the hydrophilic nonwoven fabric evaporates into the atmosphere from the waistband member, which facilitates the removal of heat of vaporization, and the difference in temperature inside the pants when the pants-type absorbent article is worn and when it is not worn is kept to 1.5°C or less. In other words, heat is less likely to be trapped inside the pants-type absorbent article, and excessive temperature rises are suppressed. This makes it less likely that the wearer will feel uncomfortable.

[0014] It is desirable that such a pants-type absorbent article has a waistband member that does not have the hydrophilic nonwoven fabric, and in the pants temperature measurement experiment, when a pants-type absorbent article having a waistband member that does not have the hydrophilic nonwoven fabric is worn by the sweating mannequin so as to cover the predetermined position, and the temperature measured at the predetermined position is defined as a third temperature, the hydrophilic nonwoven fabric is arranged in the waistband member so that the difference between the third temperature 60 minutes after the start of supplying power to the sweating mannequin and the first temperature 60 minutes after the start of supplying power to the sweating mannequin is 1°C or more.

[0015] According to such a pants-type absorbent article, the temperature rise after 60 minutes can be reduced by 1°C or more compared to pants-type absorbent articles that do not use hydrophilic nonwoven fabric. In other words, compared to pants-type absorbent articles made of conventional hydrophobic nonwoven fabric, it is possible to more easily suppress the temperature rise when worn, thereby making it less likely for the wearer to feel uncomfortable.

[0016] In such a pants-type absorbent article, it is desirable that the hydrophilic nonwoven fabric is arranged in the waistband member so that, in the pants temperature measurement experiment, the temperature rise rate per unit time of the first temperature for 30 minutes after the start of power supply to the sweating mannequin is less than half the temperature rise rate per unit time of the third temperature for 30 minutes after the start of power supply to the sweating mannequin.

[0017] According to such a pants-type absorbent article, the temperature rise rate after 30 minutes can be reduced to half or less compared to pants-type absorbent articles that do not use hydrophilic nonwoven fabric. In other words, compared to pants-type absorbent articles made of conventional hydrophobic nonwoven fabric, the temperature rise immediately after wearing (30 minutes) is kept low, and a pants-type absorbent article with excellent usability can be realized. This makes it possible to reduce the discomfort felt by the wearer.

[0018] In such a pants-type absorbent article, it is desirable that the waist member has a ventral waist portion and a dorsal waist portion, and that the predetermined position is in a position that is covered by at least one of the ventral waist portion and the dorsal waist portion when the pants-type absorbent article is worn by the sweating mannequin.

[0019] Such a pants-type absorbent article, when worn, tends to suppress a rise in temperature at the position of the wearer's body covered by the waist member, that is, tends to suppress an excessive rise in the temperature inside the pants or stuffiness inside the pants in the front and rear waist regions of the wearer where sweating is likely to occur, making it less likely that the wearer will feel uncomfortable.

[0020] It also becomes clear that there is a pants-type absorbent article having a liquid-absorbing absorbent main body with intersecting vertical, horizontal, and front-to-back directions, and a waistband member arranged on the side away from the skin of the absorbent main body, characterized in that in at least a portion of the waistband member, it has a hydrophobic nonwoven fabric arranged on the side closest to the skin, a hydrophilic nonwoven fabric layered adjacent to the side away from the skin of the hydrophobic nonwoven fabric and having a higher hydrophilicity than the hydrophobic nonwoven fabric, and an elastic member arranged between the hydrophobic nonwoven fabric and the hydrophilic nonwoven fabric, which stretches in the left-to-right directions.

[0021] In such a pants-type absorbent article, when the elastic members contract, the hydrophobic nonwoven fabric also contracts, shortening the interfiber distance of the fibers constituting the hydrophobic nonwoven fabric, which causes capillary action and facilitates absorption of moisture from the wearer's body. When the elastic members stretch, the hydrophobic nonwoven fabric and the hydrophilic nonwoven fabric also stretch, facilitating surface contact with each other, and moisture absorbed by the hydrophobic nonwoven fabric migrates to the hydrophilic nonwoven fabric side (non-skin side) and diffuses through the hydrophilic nonwoven fabric, evaporating from the non-skin side of the hydrophilic nonwoven fabric to the outside (non-skin side). This achieves a pants-type absorbent article that can absorb moisture from the wearer's skin and efficiently evaporate the absorbed moisture into the atmosphere.

[0022] In such a pants-type absorbent article, it is desirable that the article has a portion where the hydrophobic nonwoven fabric and the hydrophilic nonwoven fabric are joined at least around the periphery of the elastic member.

[0023] In such pants-type absorbent articles, the hydrophobic nonwoven fabric and the hydrophilic nonwoven fabric are easily stretched by the elastic members, facilitating moisture transfer. Furthermore, since the sheets are in close contact with each other at the joints, moisture can be easily transferred from the hydrophobic nonwoven fabric to the hydrophilic nonwoven fabric. This allows moisture to evaporate easily in the absorbent article, making it less likely for the wearer to feel uncomfortable.

[0024] In such a pants-type absorbent article, it is desirable that the hydrophobic nonwoven fabric and the hydrophilic nonwoven fabric are bonded together via the elastic member using an adhesive.

[0025] In such a pants-type absorbent article, the stretching force of the elastic members is easily transmitted to the hydrophobic nonwoven fabric and the hydrophilic nonwoven fabric, and the oil agent contained in the adhesive enhances the hydrophilicity of the joints, allowing for smoother moisture transfer.

[0026] In such a pants-type absorbent article, it is desirable that the waist member has a front waist member and a rear waist member, and has a pair of side joints that join the front waist member and the rear waist member at both left and right ends, and that at least a portion of the waist member is located in any part between the pair of side joints in the left and right direction.

[0027] According to such a pants-type absorbent article, the "region between the pair of side joints" comes into contact with the waist region where the wearer is likely to sweat and become stuffy when wearing the absorbent article. Therefore, by absorbing moisture in the waist region of the wearer and facilitating its evaporation into the atmosphere, discomfort can be reduced.

[0028] In such a pants-type absorbent article, it is desirable that the at least a portion of the waistband member is provided on the rear waistband member.

[0029] With such pants-type absorbent articles, when the wearer wears the absorbent article, the article absorbs moisture in the back waist area, where the wearer is more likely to sweat and become stuffy, and allows it to evaporate into the atmosphere, making it less likely that the wearer will feel uncomfortable.

[0030] In such a pants-type absorbent article, it is desirable that at least a portion of the hydrophilic nonwoven fabric is disposed on the side of the waistband member closest to the wearer's skin.

[0031] In such a pants-type absorbent article, the hydrophilic nonwoven fabric is disposed in the outermost layer of the waistband member, which increases the area of ​​the interface between the hydrophilic nonwoven fabric and the atmosphere, making it easier for the moisture held in the hydrophilic nonwoven fabric to evaporate into the atmosphere, thereby enabling efficient evaporation of moisture.

[0032] In such a pants-type absorbent article, it is desirable that the waistband member has a two-layer structure in which one layer of the hydrophilic nonwoven fabric and one layer of the hydrophobic nonwoven fabric are laminated.

[0033] In this pants-type absorbent article, the waistband member does not have any unnecessary sheet members, so the hydrophobic nonwoven fabric absorbs moisture from the wearer's skin and the hydrophilic nonwoven fabric evaporates the absorbed moisture into the atmosphere, which is less likely to be hindered, allowing for efficient moisture evaporation. Furthermore, this configuration allows the hydrophilic nonwoven fabric to be disposed over the entire longitudinal length of the waistband member (from the upper end to the lower end). This allows for widespread absorption and evaporation of moisture in areas prone to sweating, such as the buttocks of the wearer, making it less likely for the wearer to feel uncomfortable.

[0034] In such a pants-type absorbent article, it is desirable that the average fiber density of the hydrophobic nonwoven fabric is higher than the average fiber density of the hydrophilic nonwoven fabric.

[0035] In such pants-type absorbent articles, the higher the fiber density of the hydrophobic nonwoven fabric, the more likely capillary action occurs. Therefore, by making the fiber density of the hydrophobic nonwoven fabric higher than that of the hydrophilic nonwoven fabric, the moisture absorption efficiency of the hydrophobic nonwoven fabric is increased, making it possible to reduce discomfort to the wearer.

[0036] In such a pants-type absorbent article, it is desirable that the hydrophobic nonwoven fabric has a plurality of compression portions that compress the hydrophobic nonwoven fabric in the thickness direction.

[0037] In such pants-type absorbent articles, the fiber density of the hydrophobic nonwoven fabric is locally increased in the areas where the compressed sections are provided, making capillary action more likely to occur. This increases the moisture absorption efficiency of the hydrophobic nonwoven fabric and reduces discomfort to the wearer. Furthermore, by providing multiple dispersed compressed sections, the rigidity of the nonwoven fabric is prevented from becoming excessively high, making it easier to maintain a comfortable feel against the skin.

[0038] In such a pants-type absorbent article, it is desirable that the hydrophilic nonwoven fabric has a plurality of openings penetrating the hydrophilic nonwoven fabric in the thickness direction.

[0039] In such pants-type absorbent articles, the side walls of the perforations can also serve as an interface with the atmosphere, so the contact area between the atmosphere and the non-skin-side sheet tends to be larger than in a case where no perforations are provided. This allows moisture to evaporate from the side walls of the perforations, increasing the moisture evaporation rate in the hydrophilic nonwoven fabric. This reduces discomfort to the wearer.

[0040] In such a pants-type absorbent article, it is desirable that the average thickness of the hydrophilic nonwoven fabric is greater than the average thickness of the hydrophobic nonwoven fabric.

[0041] In such pants-type absorbent articles, the thicker the hydrophilic nonwoven fabric, the deeper the perforations in the thickness direction and the larger the area of ​​the side walls of the perforations. This increases the area of ​​the interface between the hydrophilic nonwoven fabric and the atmosphere, and increases the amount of moisture evaporating from the hydrophilic nonwoven fabric. This increases the moisture evaporating rate in the hydrophilic nonwoven fabric, making it less likely that the wearer will feel uncomfortable.

[0042] In such a pants-type absorbent article, it is desirable that the outer edges of the perforations have convex portions that are convex toward the skin side of the hydrophilic nonwoven fabric.

[0043] In such a pants-type absorbent article, the hydrophilic nonwoven fabric and the hydrophobic nonwoven fabric are easily brought into contact with each other via the convex portions, which facilitates the transfer of moisture absorbed by the hydrophobic nonwoven fabric to the hydrophilic nonwoven fabric, making it difficult for moisture to be retained in the hydrophobic nonwoven fabric that is in contact with the wearer's skin, and reducing discomfort to the wearer.

[0044] In such a pants-type absorbent article, it is desirable that the apertures and the elastic members have overlapping portions.

[0045] In such pants-type absorbent articles, the openings are provided in positions that are susceptible to the effects of the stretching of the elastic members, and therefore, when the elastic members stretch, evaporation of moisture from the side walls of the openings into the atmosphere can be promoted, thereby reducing discomfort to the wearer.

[0046] In such a pants-type absorbent article, it is desirable that a plurality of the apertures are provided between two of the elastic members arranged adjacent to each other in the up-down direction.

[0047] In such a pants-type absorbent article, the provision of a plurality of apertures in the region between the top and bottom of the elastic members increases the area of ​​the interface between the hydrophilic nonwoven fabric and the atmosphere, which allows for efficient evaporation of moisture even in regions that are less affected by the stretching of the elastic members, thereby reducing discomfort to the wearer.

[0048] In such a pants-type absorbent article, it is desirable that the hydrophobic nonwoven fabric does not have through-holes that penetrate the hydrophobic nonwoven fabric in the thickness direction.

[0049] In such pants-type absorbent articles, the hydrophobic nonwoven fabric does not have through-holes, so the area of ​​contact between the hydrophobic nonwoven fabric and the wearer's skin is not reduced, and the hydrophobic nonwoven fabric can more efficiently absorb moisture, thereby reducing discomfort to the wearer.

[0050] In such a pants-type absorbent article, it is desirable that the average basis weight of the hydrophilic nonwoven fabric is greater than the average basis weight of the hydrophobic nonwoven fabric.

[0051] In such pants-type absorbent articles, the basis weight of the hydrophilic nonwoven fabric is made larger than that of the hydrophobic nonwoven fabric, thereby increasing the water retention capacity of the hydrophilic nonwoven fabric. This makes it easier for moisture to migrate from the hydrophobic nonwoven fabric to the hydrophilic nonwoven fabric. Furthermore, by transferring moisture from the hydrophobic nonwoven fabric to the hydrophilic nonwoven fabric, the hydrophobic nonwoven fabric can absorb new moisture from the wearer's skin. This reduces discomfort to the wearer.

[0052] ===First Embodiment=== A pants-type disposable diaper (hereinafter also referred to as "diaper 1") will be taken as an example of the pants-type absorbent article according to the present invention. However, pants-type absorbent articles according to the present invention also include pants-type napkins and other pants-type absorbent articles.

[0053] <Diaper 1 composition> FIG. 1 is a schematic perspective view of a diaper 1. FIG. 2 is a plan view of the diaper 1 in an unfolded and stretched state. FIG. 3 is a schematic cross-sectional view taken along line AA in FIG. 2. The "stretched state" of the diaper 1 refers to a state in which the entire diaper 1 (the entire product) is stretched without wrinkles, specifically, a state in which the dimensions of each component constituting the diaper 1 (e.g., the absorbent body 10 and waistband component 20, which will be described later) are stretched to the same dimensions as or close to the dimensions of the component alone.

[0054] In the pants-type state shown in FIG. 1, the diaper 1 has a vertical direction, a horizontal direction, and a front-to-back direction, which intersect with one another, and has a waist opening BH and a pair of leg openings LH, LH. The upper side in the vertical direction corresponds to the waist opening BH side, and the lower side corresponds to the crotch side. The front side in the front-to-back direction corresponds to the wearer's abdominal side, and the rear side corresponds to the wearer's back side. In the unfolded state shown in FIG. 2, the diaper 1 has a vertical direction and a horizontal direction, which intersect with one another. The vertical direction is the vertical direction in FIG. 1 and corresponds to the longitudinal direction of the absorbent main body 10. The horizontal direction is the horizontal direction in FIG. 1. As shown in FIG. 3, the direction in which the materials constituting the diaper 1 are layered is referred to as the thickness direction. In the thickness direction, the side that comes into contact with the wearer's skin is referred to as the skin side, and the opposite side is referred to as the non-skin side.

[0055] The diaper 1 comprises a liquid-absorbent main body 10 and a waistband member 20 disposed on the non-skin side of the absorbent main body 10. The waistband member 20 comprises a front waistband section 30 corresponding to the front body section of the diaper 1 and a rear waistband section 40 corresponding to the rear body section of the diaper 1. That is, the diaper 1 of the first embodiment is a so-called three-piece pants-type diaper, comprising the absorbent main body 10 as a first component, which is placed in the crotch area of ​​the wearer and absorbs urine and other body waste, the front waistband section 30 as a second component, which covers the wearer's abdominal region, and the rear waistband section 40 as a third component, which covers the wearer's dorsal region.

[0056] In the unfolded state shown in Fig. 2, the front waistline portion 30 and the rear waistline portion 40 are aligned parallel to each other with a vertical gap between them, with the absorbent main body 10 suspended between them, and each of the longitudinal (vertical) ends 10ea, 10eb of the absorbent main body 10 joined and fixed to the skin side of the nearest waistline portion 30, 40, resulting in a generally H-shaped appearance in a plan view. From this state, the absorbent main body 10 is then folded in half, with its longitudinal center position CL as the folding position. In this folded state, the opposing front waistline portion 30 and rear waistline portion 40 are joined and connected to each other at the side portions 30sw and 40sw on both the left and right sides, thereby forming a pair of side joining portions 50, 50. That is, the front waistline portion 30 and the rear waistline portion 40 are formed into an annular shape by the pair of side joining portions 50, 50. This results in a pants-type diaper 1 having a waist opening BH and a pair of leg openings LH, LH as shown in Fig. 1. The side joining portions 50 are formed by known joining means such as welding or adhesive.

[0057] (Absorbent body 10) Fig. 4A is a plan view of the absorbent main body 10, and Fig. 4B is a schematic cross-sectional view of the absorbent main body 10. The absorbent main body 10 has an absorbent core 11 that absorbs excrement, a top sheet 12 that is arranged closer to the skin than the absorbent core 11 in the thickness direction, and a back sheet 13 that is arranged closer to the skin than the absorbent core 11. However, the absorbent main body 10 may also include sheet members other than these. For example, a second sheet (not shown) may be provided between the top sheet 12 and the absorbent core 11 in the thickness direction.

[0058] The absorbent core 11 is a member that absorbs and retains excretory liquids such as urine, and is formed of liquid-absorbent fibers, such as pulp fibers mixed with superabsorbent polymer (SAP). The outer periphery of the absorbent core 11 may be covered with a liquid-permeable sheet material (core wrap sheet 11b), such as tissue paper or nonwoven fabric. The absorbent core 11 of this embodiment has a constricted portion 11c, which narrows in the left-right direction, between its front and rear longitudinal ends, and has a generally hourglass shape in plan view as shown in FIG. 4A. This constricted portion 11c is the portion that is sandwiched between the wearer's legs when the diaper 1 is worn. The shortened length (narrowed width) of this portion in the left-right direction allows the absorbent core 11 to fit easily between the wearer's crotch. In this embodiment, the absorbent core 11 is configured as two layers stacked in the thickness direction, as shown in FIG. 4B, but the shape of the absorbent core 11 is not limited to this.

[0059] The top sheet 12 is a liquid-permeable sheet, and is made of, for example, a hydrophilic air-through nonwoven fabric or a spunbond nonwoven fabric. In this embodiment, both left and right side portions are folded back toward the non-skin side so as to wrap around the absorbent core 11, as shown in Figure 4B.

[0060] The back sheet 13 has a two-layer structure consisting of a liquid-impermeable sheet 13a and a hydrophobic outer sheet 13b arranged on the non-skin side thereof. The liquid-impermeable sheet 13a may be made of, for example, a resin film, and the outer sheet 13b may be made of, for example, a flexible nonwoven fabric.

[0061] A pair of leakage preventing walls 15 is provided on both left-right side portions of the absorbent main body 10 along the vertical direction (the longitudinal direction of the absorbent main body 10). In this embodiment, the leakage preventing walls 15 are formed by the above-mentioned exterior sheet 13b. Specifically, in the left-right direction (horizontal direction), a portion of the exterior sheet 13b extends outward beyond both ends of the absorbent core 11 and is folded toward the skin at multiple locations as shown in FIG. 4B , thereby forming the pair of leakage preventing walls 15. A leakage preventing wall elastic member 16 such as rubber thread is attached to the skin-side end (tip) of each leakage preventing wall 15 in a stretched state along the vertical direction (the longitudinal direction of the absorbent main body 10). When the diaper 1 is worn, the leakage preventing wall elastic member 16 exhibits stretchability, causing the leakage preventing wall 15 to rise toward the skin of the wearer and fit snugly against the wearer's crotch area.

[0062] Furthermore, leg elastic members 17 such as rubber threads are attached to both left and right side portions of the absorbent main body 10 in a stretched state along the vertical direction (the longitudinal direction of the absorbent main body 10). When the diaper 1 is worn, the stretchability of the leg elastic members 17 causes both side portions of the absorbent main body 10 to contract, making it easier to fit around the wearer's legs.

[0063] (Front waistband 30) 3, the front waistline portion 30 has a skin-side sheet 31 arranged closest to the skin in the thickness direction, a non-skin-side sheet 32 ​​laminated adjacent to the non-skin-side of the skin-side sheet 31, and waistline elastic members 35 provided in the thickness direction between the skin-side sheet 31 and the non-skin-side sheet 32. The front waistline portion 30 basically has a two-layer structure consisting of the skin-side sheet 31 and the non-skin-side sheet 32, but may partially have a three-layer or more layer structure, for example, a skin-side sheet 36 described below.

[0064] The skin-side sheet 31 and the non-skin-side sheet 32 ​​are sheet members each having a rectangular shape in plan view as shown in Fig. 2, and are formed of, for example, an SMS nonwoven fabric. In the diaper 1, the sheet member (nonwoven fabric) constituting the non-skin-side sheet 32 ​​has a higher hydrophilicity than the sheet member (nonwoven fabric) constituting the skin-side sheet 31. That is, the skin-side sheet 31 is formed of a nonwoven fabric with low hydrophilicity (hereinafter also referred to as a "hydrophobic nonwoven fabric"), and the non-skin-side sheet 32 ​​is formed of a nonwoven fabric with a higher hydrophilicity than the skin-side sheet 31 (hereinafter also referred to as a "hydrophilic nonwoven fabric"). The hydrophilicity of each sheet 31, 32 and the functions based on the difference in hydrophilicity will be described in detail later.

[0065] The surface of the non-skin-side sheet 32 ​​is provided with a plurality of apertures 32h, as shown in the partially enlarged view of FIG. 2. The apertures 32h are through-holes that penetrate the non-skin-side sheet 32 ​​in the thickness direction, and the provision of the apertures 32h improves the breathability of the front waistline portion 30. Furthermore, the apertures 32h are visibly positioned on the non-skin-facing side of the front waistline portion 30, making it easier for the user to recognize that the front waistline portion 30 has good breathability. Each aperture 32h may be circular, for example, with a diameter of approximately 1 mm, but the shape and arrangement (number and pattern) of the apertures 32h can be changed as appropriate. In the diaper 1, the skin-side sheet 31 does not have through-holes corresponding to the apertures 32h.

[0066] The front waistline portion 30 of this embodiment has a folded-back portion 32f where the upper end (front end in the longitudinal direction) of the non-skin side sheet 32 ​​is folded back from the non-skin side to the skin side and from the front side to the back side in the longitudinal direction. This folded-back portion 32f covers a part (upper end) of the skin side sheet 31, thereby preventing the upper edge of the skin side sheet 31 from digging into the wearer's skin. However, the folded-back portion 32f is not necessarily provided.

[0067] The waist elastic members 35 are arranged in a line in the vertical direction and are attached in a stretched state in the left-right direction between the skin side sheet 31 and the non-skin side sheet 32. The stretchability exhibited by the waist elastic members 35 allows the front waist portion 30 to fit the abdominal waist of the wearer.

[0068] The waistline elastic members 35 can be attached using an adhesive such as a hot melt adhesive. For example, the waistline elastic members 35 can be attached by applying a hot melt adhesive to the waistline elastic members 35, stretching them at a predetermined stretch ratio, and sandwiching them between the skin side sheet 31 and the non-skin side sheet 32. That is, the skin side sheet 31 and the non-skin side sheet 32 ​​are joined by the adhesive via the waistline elastic members 35. The waistline elastic members 35 may also be attached by applying an adhesive to the skin side sheet 31 and the non-skin side sheet 32, or by welding using the welding portions 60 described below.

[0069] The front waistband portion 30 may also have a skin-contact sheet 36. As shown in FIG. 3, the skin-contact sheet 36 is a sheet member arranged to cover the upper end (front end in the longitudinal direction) of the absorbent main body 10 from the skin side, and functions as a cover sheet. This prevents the upper end edge of the absorbent main body 10 from digging into the wearer's skin when the diaper 1 is worn. The skin-contact sheet 36 is made of, for example, an SMS nonwoven fabric. The skin-contact sheet 36 does not necessarily have to be provided.

[0070] When a sheet member is provided in the front waistband portion 30 of this embodiment closer to the skin than the skin-side sheet 31 or closer to the skin than the non-skin-side sheet 32, each sheet is arranged so as to cover only a portion of the skin-side sheet 31 and the non-skin-side sheet 32. For example, the skin-side sheet 36 in Fig. 3 is provided so as to cover only a portion of the skin-side of the skin-side sheet 31, leaving at least a portion of the skin-side sheet 31 exposed to the skin side of the wearer.

[0071] (Rear waistband 40) The rear waistline portion 40 has a configuration substantially similar to that of the front waistline portion 30. That is, the rear waistline portion 40 has a skin-side sheet 41 disposed closest to the skin in the thickness direction, a non-skin-side sheet 42 laminated adjacent to the non-skin-side side of the skin-side sheet 41, and waistline elastic members 45 provided between the skin-side sheet 41 and the non-skin-side sheet 42 in the thickness direction. As with the front waistline portion 30, the rear waistline portion 40 may also have apertures 42h, folded-back portions 42f, a skin-facing sheet 46, etc. (see Figures 2 and 3). The configuration of each member is substantially similar to that of the front waistline portion 30, and therefore a description thereof will be omitted.

[0072] On the other hand, the external shape of the rear waistline portion 40 is different from that of the front waistline portion 30. Specifically, as shown in FIG. 2, the rear waistline portion 40 has a crotch region 40b that is generally trapezoidal in shape below the side joint portions 50 (side portions 40sw). The width of the crotch region 40b increases from the bottom to the top in the vertical direction, and the provision of the crotch region 40b enables the rear waistline portion 40 to cover the buttocks of the wearer when the diaper 1 is worn. In other words, the crotch region 40b functions as a buttocks cover.

[0073] The crotch region 40b is provided with a curved elastic member 47 such as rubber thread as shown in Fig. 2. The curved elastic member 47 is attached between the skin side sheet 41 and the non-skin side sheet 42 in a stretched state along the outer edge of the crotch region 40b, and the stretchability of the curved elastic member 47 allows the crotch region 40b of the rear waistband 40 to fit easily around the buttocks of the wearer when the diaper 1 is worn, and also prevents the diaper from rolling up from the buttocks.

[0074] <Hydrophilicity of sheet material> The hydrophilicity of the sheet members will now be described. In the diaper 1, a hydrophobic nonwoven fabric is used as the skin-side sheet 31, and a hydrophilic nonwoven fabric with higher hydrophilicity than the skin-side sheet 31 is used as the non-skin-side sheet 32. The hydrophilic nonwoven fabric of this embodiment is enhanced in hydrophilicity by applying a predetermined oil to the hydrophobic nonwoven fabric (hydrophilic treatment). Examples of oils used in the hydrophilic treatment include commercially available oils that act as antistatic agents for fibers, such as anionic oils, nonionic oils, and blends thereof. By adding these oils to an oil bath and oiling the nonwoven fabric using an oiling roller or the like, the hydrophilicity of the hydrophobic nonwoven fabric can be enhanced, resulting in a hydrophilic nonwoven fabric. However, hydrophilic nonwoven fabrics may also be formed by other methods. For example, a hydrophilic nonwoven fabric may be obtained by manufacturing a nonwoven fabric using highly hydrophilic fibers.

[0075] In this embodiment, the entire nonwoven fabric constituting the non-skin side sheet 32 ​​is subjected to a hydrophilic treatment, thereby increasing the hydrophilicity of the entire non-skin side sheet 32, but the hydrophilicity may be increased only in a partial region of the non-skin side sheet 32. For example, by subjecting only a partial region of the non-skin side sheet 32 ​​to a hydrophilic treatment, the sheet member may have locally high and low hydrophilic areas.

[0076] The hydrophilicity of a sheet member can be evaluated by measuring the contact angle when ion-exchanged water is brought into contact with the surface of the sheet member. Specifically, if the contact angle between a hydrophilic nonwoven fabric and ion-exchanged water is smaller than the contact angle between a hydrophobic nonwoven fabric and ion-exchanged water, the hydrophilic nonwoven fabric is more hydrophilic than the hydrophobic nonwoven fabric. The hydrophilic nonwoven fabric (non-skin-side sheet 32) used in this embodiment preferably has a contact angle with ion-exchanged water of less than 90 degrees, more preferably 50 degrees or less. On the other hand, the hydrophobic nonwoven fabric (skin-side sheet 31) preferably has a contact angle with ion-exchanged water of 90 degrees or more, more preferably 120 degrees or more.

[0077] The contact angle can be measured, for example, using a contact angle meter MCA-J manufactured by Kyowa Interface Science Co., Ltd., in the following manner. First, ion-exchanged water (approximately 20 picoliters) is dropped onto the surface of the fibers constituting the sheet member (measurement target sheet) to be measured, and the contact angle is immediately measured using the contact angle meter. Measurements are taken at multiple locations (e.g., five or more locations) on the surface of the measurement target sheet, and the average value of these measurements is taken as the contact angle. The measurement environment temperature is 22°C.

[0078] Alternatively, the contact angle may be measured by imaging the test sheet onto which ion-exchanged water has been dropped from the cross-sectional direction of the test sheet, analyzing the image, and measuring the angle between the ion-exchanged water droplet and the test sheet.

[0079] <About water absorption and evaporation> Next, we will explain the mechanism by which the waistline member 20 of the diaper 1 absorbs moisture from the wearer's skin and evaporates the absorbed moisture into the atmosphere. Figures 5A and 5B are diagrams illustrating the cross-sectional shape of the front waistline portion 30 when the diaper 1 is worn. Both Figures 5A and 5B schematically show cross sections in the thickness direction and the up-down direction, with Figure 5A showing the state when the waistline elastic member 35 is contracted in the left-right direction and Figure 5B showing the state when the waistline elastic member 35 is stretched in the right direction. Note that while the following description will focus on the front waistline portion 30, the same applies to the rear waistline portion 40.

[0080] When a wearer puts on the diaper 1, the waist elastic members 35 provided on the front waist portion 30 contract in the left-right direction, causing the front waist portion 30 to fit the wearer's waist and prevent misalignment. As the waist elastic members 35 contract in the left-right direction, the skin-side sheet 31 and the non-skin-side sheet 32 ​​joined via the waist elastic members 35 also contract in the left-right direction. As a result, multiple wrinkles extending in the up-down direction are formed on the surface of the front waist portion 30, as shown in Fig. 1. These wrinkles are formed when parts of the flat sheet members protrude in the thickness direction when the non-skin-side sheet 32 ​​(and the skin-side sheet 31) contract in the left-right direction. In Figure 5A, small wrinkles are formed between two adjacent waist elastic members 35, 35 in the vertical direction by the non-skin side sheet 32 ​​protruding toward the non-skin side in the thickness direction (the side not facing the wearer's skin), and these small wrinkles are lined up in a row in the vertical direction, forming wrinkles that extend in the vertical direction.

[0081] From this state, when the wearer moves by walking, sitting, or standing, the contracted waist elastic members 35 stretch, and as a result, portions of the skin-side sheet 31 and the non-skin-side sheet 32 ​​also stretch in the left-right direction. As a result, the skin-side sheet 31 and the non-skin-side sheet 32 ​​do not protrude in the thickness direction in the stretched portions, and the sheets return to a flat shape conforming to the skin as shown in Figure 5B. While the diaper 1 is worn by a wearer, the above-mentioned contracted state (Figure 5A) and stretched state (Figure 5B) are alternately repeated.

[0082] Fig. 6 is an enlarged cross-sectional view of region X in Fig. 5A. In Fig. 6, when the waistline elastic members 35 contract in the left-right direction, the skin side sheet 31 also contracts in the left-right direction as described above. As a result, the fibers constituting the skin side sheet 31 are compressed in the left-right direction, narrowing the inter-fiber distance and making the fibers constituting the skin side sheet 31 denser.

[0083] In this state, when the skin-side sheet 31 (hydrophobic sheet) is pressed against the wearer's skin, moisture such as sweat adhering to the wearer's skin is easily absorbed by the skin-side sheet 31. This is because the dense fibers constituting the skin-side sheet 31 facilitate the absorption of moisture between the fibers by capillary action. In this way, in the front waist region 30 of the diaper 1, the skin-side sheet 31 made of hydrophobic nonwoven fabric is contracted by the waist elastic members 35, thereby facilitating the absorption of moisture from the wearer's skin.

[0084] FIG. 7 is an enlarged cross-sectional view of region Y in FIG. 5B. When the waistline elastic members 35 stretch, the skin-side sheet 31 and the non-skin-side sheet 32 ​​also stretch and become planar. Therefore, the non-skin-side surface of the skin-side sheet 31 and the skin-side surface of the non-skin-side sheet 32 ​​overlap and tend to come into surface contact with each other. That is, compared to the case of FIG. 6, the contact area between the skin-side sheet 31 and the non-skin-side sheet 32 ​​is larger. As a result, moisture absorbed by the skin-side sheet 31 migrates from the skin-side sheet 31 side to the non-skin-side sheet 32 ​​side through the contact area, diffusing within the non-skin-side sheet 32. In this embodiment, the non-skin-side sheet 32, which is made of a hydrophilic nonwoven fabric, is more hydrophilic than the skin-side sheet 31, which is made of a hydrophobic nonwoven fabric. Therefore, moisture migrates toward the more hydrophilic nonwoven fabric and more easily diffuses. This reduces the likelihood of moisture remaining in the skin-side sheet 31 and coming into contact with the wearer's skin.

[0085] FIG. 8 is an enlarged cross-sectional view of region Y in FIG. 5B, showing the state after a predetermined time has elapsed since the state in FIG. 7. Moisture that migrates from the skin-side sheet 31 to the non-skin-side sheet 32 ​​diffuses into the highly hydrophilic non-skin-side sheet 32 ​​and evaporates from the non-skin side of the non-skin-side sheet 32 ​​(the interface between the non-skin-side sheet 32 ​​and the atmosphere in FIG. 8) to the outside (non-skin side). In this embodiment, the non-skin-side sheet 32 ​​itself elongates as the waistline elastic members 35 elongate, which facilitates moisture diffusion within the non-skin-side sheet 32 ​​and facilitates moisture evaporation over a wide area of ​​the non-skin-side sheet 32. As moisture held in the non-skin-side sheet 32 ​​evaporates to the non-skin side, moisture is more likely to migrate from the skin-side sheet 31 to the non-skin-side sheet 32.

[0086] In this way, the front waistband portion 30 of the diaper 1 absorbs moisture from the wearer's skin and evaporates the absorbed moisture to the non-skin-side surface of the non-skin-side sheet 32 ​​(hydrophilic nonwoven fabric). When the wearer moves while wearing the diaper 1, the waistband elastic members 35 expand and contract, causing the moisture transfer process described in FIGS. 6 to 8 to be repeated. This allows moisture to be absorbed from the wearer's skin and efficiently released to the non-skin-side surface, reducing discomfort to the wearer. The above-described effects can be achieved even if another sheet member is laminated on the non-skin-side surface of the non-skin-side sheet 32. However, if no other sheet member is laminated on the non-skin-side surface of the non-skin-side sheet 32 ​​(i.e., if the non-skin-side surface of the non-skin-side sheet 32 ​​faces the atmosphere), the evaporation efficiency can be further improved. Therefore, it is desirable that the non-skin-side sheet 32 ​​be positioned closest to the skin in the waistband member 20 (front waistband portion 30) of the diaper 1.

[0087] Furthermore, in the front waistline portion 30, the waistline elastic members 35 are disposed between the skin-side sheet 31 and the non-skin-side sheet 32, which facilitates the absorption of moisture from the wearer's skin and the evaporation of the moisture into the atmosphere. If the waistline elastic members 35 were disposed closer to the skin than the skin-side sheet 31, gaps would be more likely to form between the wearer's skin and the skin-side sheet 31. This would reduce the contact area between the wearer's skin and the skin-side sheet 31, potentially making it difficult to absorb moisture from the wearer's skin. Furthermore, if the waistline elastic members 35 were disposed closer to the skin than the non-skin-side sheet 32, the front waistline elastic members 35 would prevent moisture from evaporating from the non-skin side of the non-skin-side sheet 32 ​​to the atmosphere, potentially making it difficult to evaporate moisture. In contrast, in this embodiment, the waistline elastic members 35 are disposed between the skin-side sheet 31 and the non-skin-side sheet 32, which prevents moisture from being impeded and allows moisture to be efficiently absorbed and evaporated.

[0088] Furthermore, in the diaper 1, the aforementioned moisture transfer is likely to occur due to the stretching of the waist elastic members 35. Therefore, it is desirable to have a portion where the skin-side sheet 31 (hydrophobic nonwoven fabric) and the non-skin-side sheet 32 ​​(hydrophilic nonwoven fabric) are joined to each other around the waist elastic members 35. This configuration significantly affects the stretching of the waist elastic members 35, enhancing the moisture evaporation effect. That is, the skin-side sheet 31 and the non-skin-side sheet 32 ​​are likely to stretch in response to the stretching of the waist elastic members 35, which facilitates moisture transfer. Furthermore, since the sheets are in close contact with each other at the joint, moisture transfer from the skin-side sheet 31, which has low hydrophilicity, to the non-skin-side sheet 32, which has high hydrophilicity, is more smoothly achieved.

[0089] Furthermore, in the front waist portion 30 (waist member 20) of the diaper 1, the skin-side sheet 31 (hydrophobic nonwoven fabric) and the non-skin-side sheet 32 ​​(hydrophilic nonwoven fabric) are bonded to each other via the waist elastic member 35 using an adhesive such as a hot melt adhesive. This allows the stretching force of the waist elastic member 35 to be directly transmitted to the skin-side sheet 31 and the non-skin-side sheet 32, further enhancing the moisture evaporation effect. In addition, the oil contained in the adhesive increases the hydrophilicity at the bonded portion between the sheets, allowing moisture to migrate more smoothly.

[0090] Furthermore, in the diaper 1, waist elastic members 35, 45 are provided between the skin-side sheets 31, 41 (hydrophobic nonwoven fabric) and the non-skin-side sheets 32, 42 (hydrophilic nonwoven fabric) in the region between the pair of side joints 50, 50 in the left-right direction. Therefore, at least one region of the waist member 20 between the pair of side joints 50, 50 is configured to easily absorb moisture from the wearer's skin and release the absorbed moisture into the atmosphere. This region is located around the waist of the wearer when the diaper 1 is worn, and is a region where the wearer is likely to sweat and become stuffy. In this embodiment, moisture can be easily absorbed in this waist region and released into the atmosphere, thereby suppressing stuffiness in the waist region when the diaper 1 is worn, thereby reducing discomfort.

[0091] In particular, when a wearer wears a pants-type diaper, the wearer tends to sweat more on the back side of the waist region than on the ventral side, making the back side more likely to become stuffy. To address this issue, the diaper 1 has a waist elastic member 45 provided between the skin-side sheet 41 (hydrophobic nonwoven fabric) and the non-skin-side sheet 42 (hydrophilic nonwoven fabric) in the rear waist region 40, in the region between the pair of side joints 50, 50 in the left-right direction. This allows moisture, such as sweat, to be absorbed on the back side of the waist region and efficiently evaporated into the air, thereby suppressing stuffiness in the back waist region and reducing discomfort.

[0092] In the diaper 1 of this embodiment, the non-skin-side sheets 32, 42 made of hydrophilic nonwoven fabric are disposed closest to the skin in the thickness direction of the waistband member 20 (30, 40) (see FIG. 3). That is, the hydrophilic nonwoven fabric is disposed in at least a portion of the outermost layer of the waistband member 20. This allows at least a portion of the hydrophilic nonwoven fabric to form an interface with the atmosphere, facilitating evaporation of moisture retained in the hydrophilic nonwoven fabric into the atmosphere. If a hydrophobic sheet member were laminated on the non-skin-side side of the hydrophilic nonwoven fabric, this laminated portion would inhibit evaporation of moisture from the hydrophilic nonwoven fabric to the atmosphere, potentially resulting in moisture retention in the hydrophilic nonwoven fabric. In contrast, in this embodiment, there is a portion where no other member is interposed between the hydrophilic nonwoven fabric and the atmosphere, allowing for efficient evaporation of moisture. Furthermore, even if other components (such as post-treatment tape for performing post-treatment operations on diaper 1) are provided on part of the non-skin side of non-skin side sheets 32, 42 (hydrophilic nonwoven fabric), the above-mentioned effects can be obtained in areas where such other components are not provided.

[0093] Furthermore, the waistline member 20 (30, 40) preferably has a two-layer structure in which two sheet members, one skin-side sheet 31 (41) made of a hydrophobic nonwoven fabric and one non-skin-side sheet 32 ​​(42) made of a hydrophilic nonwoven fabric, are laminated in the thickness direction. By eliminating any unnecessary sheet members in the waistline member 20, the above-mentioned moisture absorption and evaporation are less likely to be hindered, allowing moisture to be released more efficiently. The waistline member 20 of this embodiment has a three-layer structure in some areas, such as the folded-back portion 32f shown in FIG. 3, but most of the waistline member 20 has a two-layer structure in which two sheet members, the skin-side sheet 31, 41 and the non-skin-side sheet 32, 42, are laminated, allowing moisture to evaporate efficiently.

[0094] Furthermore, with this structure, the hydrophilic nonwoven fabric is disposed over the entire length of the waistband member 20 (30, 40) (the vertical direction of the diaper 1), and therefore moisture absorption and evaporation effects can be achieved from the upper end to the lower end of the waistband member 20. For example, when a wearer puts on the diaper 1, moisture such as sweat can be easily expelled to the outside of the diaper 1 over a wide area on the back side of the wearer (the rear waistband member 40) from the back to the buttocks. Therefore, moisture is less likely to come into contact with the skin even in the lower end region of the waistband, such as the buttocks, where sweating is likely to occur, and discomfort to the wearer can be reduced.

[0095] However, this does not preclude the provision of another sheet member on the non-skin side of the hydrophilic nonwoven fabric (non-skin side sheets 32, 42) in the waistband member 20. For example, the skin side sheet 31 (hydrophobic nonwoven fabric) may be folded back to the non-skin side and laminated so as to cover part of the non-skin side of the non-skin side sheet 32. Even in such a case, the moisture transpiration effect is maintained in the non-laminated portion, making it less likely that the wearer will feel uncomfortable.

[0096] Furthermore, in the waistband member 20 of the diaper 1, the average fiber density of the hydrophobic nonwoven fabric (skin-side sheets 31, 41) is preferably greater than the average fiber density of the hydrophilic nonwoven fabric (non-skin-side sheets 32, 42). In this embodiment, when the waistband elastic members 35, 45 contract, the inter-fiber distance between the fibers constituting the hydrophobic nonwoven fabric decreases, resulting in capillary action, which allows the hydrophobic nonwoven fabric to absorb moisture from the wearer's skin. Therefore, the higher the fiber density of the hydrophobic nonwoven fabric, the more easily capillary action occurs, and the easier it is to absorb moisture. Furthermore, because the transfer of moisture from the hydrophobic nonwoven fabric to the hydrophilic nonwoven fabric occurs based on the difference in hydrophilicity between the nonwoven fabrics, even if the fiber density of the hydrophobic nonwoven fabric is increased, the function of evaporating absorbed moisture into the atmosphere is not easily impaired. Therefore, by making the fiber density of the hydrophobic nonwoven fabric higher than that of the hydrophilic nonwoven fabric, the moisture (sweat, etc.) absorption efficiency of the hydrophobic nonwoven fabric is improved, making it less likely for the wearer to feel uncomfortable, compared to when the fiber density is lower than that of the hydrophilic nonwoven fabric. The average fiber density of the nonwoven fabric is determined by measuring the weight and the average thickness (described below) of a sheet piece cut into a predetermined size from the nonwoven fabric to be measured, and dividing the weight of the sheet piece by the product of the area and average thickness of the sheet piece (the volume of the sheet piece).

[0097] One method for increasing the fiber density of the hydrophobic nonwoven fabric (skin side sheets 31, 41) is to provide compressed portions that compress portions of the hydrophobic nonwoven fabric in the thickness direction. Specifically, multiple compressed portions may be formed in a dispersed manner by, for example, embossing the surface of the hydrophobic nonwoven fabric. In the areas where such compressed portions (embossments) are provided, the fiber density of the hydrophobic nonwoven fabric is locally increased, making capillary action more likely to occur. Furthermore, providing fine compressed portions in a dispersed manner prevents the nonwoven fabric from becoming excessively rigid, making it easier to maintain a pleasant feel against the skin. This increases the efficiency with which the hydrophobic nonwoven fabric absorbs moisture (such as sweat), reducing discomfort to the wearer.

[0098] Furthermore, the waistband member 20 of the diaper 1 is provided with a plurality of apertures 32h, 42h penetrating the hydrophilic nonwoven fabric (non-skin side sheets 32, 42) in the thickness direction, which facilitates moisture evaporation. Fig. 9, which corresponds to Fig. 8, illustrates moisture evaporation when the non-skin side sheet 32 ​​is provided with apertures 32h. As described in Fig. 8, when moisture evaporates from the non-skin side sheet 32, moisture evaporates from the interface between the non-skin side sheet 32 ​​and the atmosphere, i.e., the non-skin side surface of the non-skin side sheet 32 ​​(denoted by 32s in Fig. 9) into the atmosphere. In contrast, when the non-skin side sheet 32 ​​is provided with apertures 32h as shown in Fig. 9, the sidewalls 32hs of the apertures 32h also form an interface with the atmosphere. In other words, the area of ​​the interface between the atmosphere and the non-skin side sheet 32 ​​is likely to be larger than when the apertures 32h are not provided. Therefore, moisture evaporates not only from the non-skin side surface 32s of the non-skin side sheet 32 ​​but also from the side wall portions 32hs of the perforations 32h, facilitating the evaporation of more moisture that has been diffused and retained in the non-skin side sheet 32. This increases the moisture evaporation rate in the hydrophilic nonwoven fabric, making it less likely for the wearer to feel uncomfortable.

[0099] When the hydrophilic nonwoven fabric (non-skin side sheet 32) has openings 32h, it is desirable that the thickness t32 of the hydrophilic nonwoven fabric (non-skin side sheet 32) be thicker than the thickness t31 of the hydrophobic nonwoven fabric (skin side sheet 31). The thicker the thickness t32 of the hydrophilic nonwoven fabric (non-skin side sheet 32), the longer the distance in the thickness direction of the openings 32h that penetrate the non-skin side sheet 32 ​​(i.e., the deeper the openings), and the larger the area of ​​the side walls 32hs of the openings 32h. This increases the area of ​​the interface between the hydrophilic nonwoven fabric and the atmosphere, making it easier for the amount of moisture transpiration from the side walls 32hs to increase. This increases the rate of moisture evaporation from the hydrophilic nonwoven fabric, reducing discomfort to the wearer. The thickness of the nonwoven fabric is measured at a portion of the nonwoven fabric to be measured where the opening 32h is not provided, using, for example, a dial thickness gauge ID-C1012C manufactured by Mitutoyo Corporation or an equivalent, and applying a contact pressure of 3 gf / cm. 2The thickness is measured at any number of locations (for example, five locations) by setting the thickness gauge to 100°C and applying pressure to the target area, and the average value is calculated. If the distance between adjacent openings 32h, 32h (i.e., the pitch of the openings 32h) is narrower than the size of the probe of the dial thickness gauge, the probe may cross the openings 32h, making it impossible to accurately measure the thickness of the portions of the nonwoven fabric where no openings 32h are provided. In such cases, it is advisable to use a non-contact thickness measuring device such as an ultrasonic thickness gauge or a laser displacement meter to measure the thickness of the portions of the nonwoven fabric where no openings 32h are provided.

[0100] Furthermore, the skin-side surface of the hydrophilic nonwoven fabric (non-skin-side sheet 32) may have protruding portions 32hp, where the outer edges of the perforations 32h are convex toward the skin side (see FIG. 9). Providing such protruding portions 32hp facilitates contact between the hydrophilic nonwoven fabric (non-skin-side sheet 32) and the non-skin-side surface of the hydrophobic nonwoven fabric (skin-side sheet 31). This facilitates the transfer of moisture absorbed by the hydrophobic nonwoven fabric to the hydrophilic nonwoven fabric (see FIG. 7). This makes it difficult for moisture to accumulate in the hydrophobic nonwoven fabric (skin-side sheet 31) that is in contact with the wearer's skin, reducing discomfort to the wearer.

[0101] The protrusions 32hp can be formed when the openings 32h are made in the manufacturing process of the hydrophilic nonwoven fabric (non-skin side sheet 32). For example, when the openings 32h are formed by inserting a predetermined pin from the non-skin side to the skin side in the thickness direction of the non-skin side sheet 32, a burr protruding toward the skin side is formed on the outer edge of the openings 32h on the skin side when the pin penetrates the parent non-skin side sheet 32, and this burr becomes the protrusion 32hp.

[0102] Furthermore, it is desirable that the front waistline portion 30 (rear waistline portion 40) have portions where the openings 32h (42h) and the waistline elastic members 35 (45) overlap. In FIG. 2, at least one of the multiple openings 32h is provided at a position overlapping the waistline elastic members 35. With this configuration, when the waistline elastic members 35 stretch in the left-right direction, moisture absorbed by the hydrophobic nonwoven fabric (skin-side sheet 31) migrates to the hydrophilic nonwoven fabric (non-skin-side sheet 32), facilitating moisture evaporation from the interface between the hydrophilic nonwoven fabric (non-skin-side sheet 32) and the atmosphere. In other words, providing the openings 32h at positions susceptible to the stretching of the waistline elastic members 35 facilitates moisture evaporation. This reduces discomfort to the wearer.

[0103] Furthermore, it is desirable to provide a plurality of apertures 32h between two adjacent waist elastic members 35, 35 in the vertical direction. In Fig. 2, a large number of apertures 32h are provided between two adjacent waist elastic members 35, 35 in the vertical direction. This increases the area of ​​the interface between the hydrophilic nonwoven fabric (non-skin side sheet 32) and the atmosphere in the region between the waist elastic members 35, 35 in the vertical direction, allowing for efficient evaporation of moisture even in regions that are less affected by the stretching of the waist elastic members 35. This reduces discomfort to the wearer.

[0104] In the waistband member 20, it is desirable that the hydrophobic nonwoven fabric (skin-side sheets 31, 41) does not have openings (through-holes) corresponding to the apertures 32h. If the hydrophobic nonwoven fabric had through-holes, the contact area between the hydrophobic nonwoven fabric and the wearer's skin would be reduced, which could hinder the absorption of moisture through capillary action as described above. In contrast, the diaper 1 of this embodiment does not have through-holes that penetrate the hydrophobic nonwoven fabric (skin-side sheets 31, 41) in the thickness direction. This prevents a reduction in the contact area between the hydrophobic nonwoven fabric and the wearer's skin, allowing the hydrophobic nonwoven fabric to efficiently absorb moisture such as sweat. This reduces discomfort to the wearer.

[0105] Furthermore, in the waistband member 20, the basis weight of the hydrophilic nonwoven fabric (non-skin side sheets 32, 42) is desirably greater than the basis weight of the hydrophobic nonwoven fabric (skin side sheets 31, 41). In general, the greater the basis weight of a nonwoven fabric, the greater the amount of moisture it can retain (water retention capacity). Therefore, by making the basis weight of the hydrophilic nonwoven fabric greater than that of the hydrophobic nonwoven fabric, the water retention capacity of the hydrophilic nonwoven fabric can be further increased. This makes it easier for moisture to migrate from the hydrophobic nonwoven fabric to the hydrophilic nonwoven fabric (see FIG. 7). Furthermore, by transferring moisture from the hydrophobic nonwoven fabric to the hydrophilic nonwoven fabric, the hydrophobic nonwoven fabric can absorb additional moisture from the wearer's skin. This reduces discomfort to the wearer. The basis weight is determined by cutting out multiple sheet pieces (e.g., 10 pieces) of a predetermined size from the sheet member to be measured, measuring the weight of each sheet piece using an electronic balance or the like, and dividing the weight by the area of ​​the sheet piece.

[0106] <Modification of the method of attaching the waist elastic members 35, 45> In the above-described embodiment, the waist elastic members 35, 45 are attached to the waist member 20 by adhesive means such as a hot melt adhesive, but the method of attaching the waist elastic members 35, 45 is not limited to this. For example, the waist elastic members 35, 45 may be attached to the waist member 20 by a welding means such as ultrasonic welding. Note that ultrasonic welding is a well-known technique, and therefore a description of ultrasonic welding will be omitted in this specification.

[0107] 10A and 10B are diagrams illustrating a method for attaching the waistline elastic members 35 to the front waistline portion 30 using welds 60. In this modification, the waistline elastic members 35 are attached to the front waistline portion 30 using a plurality of welds 60, 60... that are discretely arranged in the left-right and up-down directions. Each weld 60 is formed into a substantially rectangular shape by ultrasonic welding, and joins the skin-side sheet 31 and the non-skin-side sheet 32 ​​of the front waistline portion 30 in the thickness direction. The waistline elastic members 35 are attached to the front waistline portion 30 by sandwiching them from both up-down directions between a pair of welds 60s consisting of two welds 60, 60 adjacent to each other in the up-down direction.

[0108] 10A, a pair of welded portions 60, 60 constituting a pair of welded portions 60s are arranged vertically with a gap GH60 therebetween. The size of the gap GH60 is set to be equal to or slightly larger than the diameter d35t of the waist elastic member 35 in a state stretched to a predetermined extension ratio (GH60≧d35t). In other words, the waist elastic member 35 in a stretched state is disposed vertically between the pair of welded portions 60s.

[0109] Next, when the waist elastic members 35 are relaxed from the stretched state, as shown in Fig. 10B, the waist elastic members 35 contract laterally and expand vertically, and the diameter d35 in the natural state becomes larger than the vertical distance GH60 between the pair of welded portions 60s (d35>GH60). As a result, the waist elastic members 35 are vertically sandwiched between the welded portions 60, 60. As a result, the waist elastic members 35 are attached to the front waist portion 30.

[0110] In the pants-type diaper 1 shown in Fig. 1, the waist elastic members 35 (45) are in a natural state, relaxed from the stretched state. In the pants-type diaper 1, the waist elastic members 35 (45) are joined to the front waist portion 30 (rear waist portion 40) by side joining portions 50, 50 on both lateral sides. Therefore, even if the front waist portion 30 (rear waist portion 40) is stretched in the lateral direction when the diaper 1 is worn, the waist elastic members 35 (45) will not come off the waist member 20.

[0111] <About the temperature inside the pants> Next, an experiment to measure the temperature inside pants, in which the change in the temperature inside the diaper 1 (also called "temperature inside pants") over time while the diaper 1 is actually being worn, will be described.

[0112] The experiment to measure the temperature inside pants was conducted as follows using a sweating mannequin equipped with temperature sensors at predetermined positions. First, the sweating mannequin described above was placed in a standing position in a room maintained at a temperature of 25°C and humidity of 50%. The sweating mannequin is a life-size doll that can intermittently discharge liquid (sweat) from multiple sweat pores on its body surface. For example, the sweating mannequin SAM (registered trademark) manufactured by Toyobo Co., Ltd. can be used. This sweating mannequin SAM uses an "intermittent liquid sweat discharge method" that intermittently discharges liquid from 168 sweat pores on its body surface at a rate of approximately once every few to several tens of seconds, thereby recreating a condition similar to the mechanism by which sweat is released from human sweat glands.

[0113] Next, temperature sensors capable of measuring temperature were installed at predetermined positions on the body surface of the sweating manikin. Fig. 11A is a diagram illustrating temperature measurement positions on the front (ventral side) of the sweating manikin, and Fig. 11B is a diagram illustrating temperature measurement positions on the back (dorsal side) of the sweating manikin. In the pants temperature measurement experiment of this embodiment, temperature sensors were installed at two positions slightly above the groin and symmetrically about the center in the left-right direction on the front waist of the sweating manikin, as shown in Fig. 11A. Furthermore, temperature sensors were installed at two positions symmetrically about the center in the left-right direction on the rear waist of the sweating manikin, as shown in Fig. 11B, where the buttocks protrude most, as the rear temperature measurement positions.

[0114] Next, a pull-on garment (e.g., diaper 1) to be tested is put on the sweating mannequin. At this time, the pull-on garment is put on so as to cover the temperature measurement position (corresponding to the predetermined position) (see Figs. 11A and 11B). That is, the pull-on garment is put on so that the temperature measurement position is located inside the pull-on garment (inside the pants).

[0115] Next, a certain amount of power is supplied to the sweating mannequin to raise its body surface temperature. In this embodiment, 120.6 W / h of power is supplied. Liquid (sweat) is then ejected from the sweating mannequin's multiple sweat pores at a rate of 100 g / m2 / h. In this embodiment, water is used as the liquid to be ejected.

[0116] Next, one minute after the start of power supply, temperature measurement at the temperature measurement positions begins, and temperature measurement is continued over time until a predetermined time has elapsed. In this experiment to measure temperature inside the pants, temperature measurement was performed for at least 60 minutes from the start of power supply, taking into account the duration of time the diaper is worn. Temperature measurements were performed independently at the front and rear temperature measurement positions, and the average value of the temperatures measured at the two front temperature measurement positions (see Figure 11A) was taken as the temperature inside the pants at the front. Similarly, the average value of the temperatures measured at the two rear temperature measurement positions (see Figure 11B) was taken as the temperature inside the pants at the rear.

[0117] 12A and 12B are diagrams showing the results of measurements of the temperature inside pants of several types of pants-type wearing articles. Fig. 12A shows the change in the temperature inside pants over time on the front side (ventral side), and Fig. 12B shows the change in the temperature inside pants over time on the back side (dorsal side).

[0118] 12A and 12B show, as Example A, the results of measuring the temperature inside the pants when the "diaper 1" according to this embodiment was worn by a sweating mannequin. That is, Example A is temperature data measured when the temperature measurement position described in FIG. 11 was covered by the diaper 1. Hereinafter, the temperature measured when the temperature measurement position was covered by the diaper 1 will also be referred to as the "first temperature."

[0119] As comparative examples for Example A, three types of pants-type wearing articles different from diaper 1 were worn by a sweating mannequin, and the results of measuring the temperature inside the pants are shown as Comparative Examples B to D. The pants-type wearing article of Comparative Example B is a pants-type diaper that does not use a hydrophilic nonwoven fabric. An example of the pants-type diaper of Comparative Example B is diaper 1 in which the non-skin-side sheets 32, 42 constituting the waistband member 20 are changed from a hydrophilic nonwoven fabric to a hydrophobic nonwoven fabric. However, pants-type diapers of other shapes may also be used as long as they do not use a hydrophilic nonwoven fabric.

[0120] The pants-type wearing article of Comparative Example C is a typical pair of cotton pants. An example of the cotton pants of Comparative Example C is commercially available underwear (not shown) made of 100% cotton. The pants-type wearing article of Comparative Example D is a typical pair of synthetic fiber pants. An example of the synthetic fiber pants of Comparative Example D is commercially available underwear (not shown) made of 92% nylon, 6% polyurethane, and 2% cotton.

[0121] 12A and 12B also show the results of measuring the temperature change over time when the sweating mannequin is not wearing anything, as Comparative Example E. That is, Comparative Example E is the temperature measured when the temperature measurement position described in FIG. 11 is not covered with anything, and is data that represents the body surface temperature of the sweating mannequin itself. Note that, hereinafter, the temperature measured when the temperature measurement position is not covered will also be referred to as the "second temperature."

[0122] When temperature measurements were performed on the sweating mannequin without any clothing (Comparative Example E), the body surface temperature (second temperature) gradually increased after power supply to the sweating mannequin began, and the front body surface temperature (second temperature) of the sweating mannequin was 33.1°C when temperature measurement began one minute later (see FIG. 12A). Similarly, the rear body surface temperature (second temperature) of the sweating mannequin was 33.2°C when temperature measurement began (see FIG. 12B).

[0123] If power is continued to be supplied in this state, the front body surface temperature of Comparative Example E gradually rises over time, and after 60 minutes the front body surface temperature (second temperature) is 33.7°C (see FIG. 12A). Also, after 60 minutes the rear body surface temperature (second temperature) is 33.3°C (see FIG. 12B). It is generally believed that an average skin temperature (surface temperature) in the range of 33-34°C is a comfortable temperature at which humans do not feel either hot or cold (Nonaka Mayu et al., "Differences between average skin temperature and skin temperature at each body part that produce a neutral thermal sensation and a comfortable sensation: A comparison between summer and winter in young women," Humans and Living Environments 16(2), 91-97, 2009).

[0124] In contrast, when the temperature inside the pants of a sweating mannequin wearing the diaper 1 was measured (Example A), the temperature inside the front pants of the sweating mannequin (first temperature) at the start of the temperature measurement was 33.1°C, and the temperature inside the back pants (first temperature) was 33.2°C. In other words, at the start of the temperature measurement, there was no clear temperature difference between the first temperature measured while wearing the diaper 1 (Example A) and the second temperature measured while wearing nothing (Comparative Example E).

[0125] In Example A, the temperature inside the pants gradually rises over time, and after 60 minutes the temperature inside the front pants (first temperature) is 34.2°C (see FIG. 12A), and after 60 minutes the temperature inside the back pants (first temperature) is 34.3°C (see FIG. 12B). In other words, it can be seen that the first temperature (Example A) measured while wearing diaper 1 is 0.5 to 1.0°C higher than the second temperature (Comparative Example E) measured while not wearing anything, approximately 60 minutes after the start of measurement (more precisely, 60 minutes after the start of power supply).

[0126] The temperature rise (0.5 to 1.0°C) in Example A is roughly the same as that in Comparative Examples C and D (see FIGS. 12A and 12B). This indicates that the temperature rise when wearing the diaper 1 of this embodiment is comparable to that of commercially available cotton or synthetic fiber pants. Furthermore, the first temperature of 34.2 to 34.3°C after 60 minutes does not deviate significantly from the aforementioned comfortable temperature range (33 to 34°C) at which a person does not feel either hot or cold. Therefore, the temperature rise when wearing the diaper 1 is comparable to that when wearing typical cloth underwear (Comparative Examples C and D), making it unlikely for the wearer to experience discomfort or unnaturalness.

[0127] It is possible that there may be an error of about ±0.5°C when measuring the temperature inside the pants, but even if the error is at its maximum, the difference between the temperature inside the front and rear pants of diaper 1 (first temperature) and the temperature when nothing is being worn (second temperature) will be 1.5°C or less.

[0128] On the other hand, in the pants-type diaper of Comparative Example B, which does not use a hydrophilic nonwoven fabric, the temperature inside the front pants was 35.3°C and the temperature inside the rear pants was 35.5°C 60 minutes after the start of power supply, which is more than 1.5°C different from the temperature when nothing is worn (Comparative Example E). Therefore, it can be seen that the temperature rise of diaper 1 is kept lower than that of the pants-type diaper of Comparative Example B.

[0129] This is because the moisture absorbed by the hydrophilic nonwoven fabric in the waistband member 20 of the diaper 1 evaporates into the atmosphere from the non-skin side of the waistband member 20, facilitating the removal of heat of vaporization. As a result, the difference (temperature rise) between the temperature inside the pants when the diaper 1 is worn (Example A) and the temperature when the diaper is not worn (Comparative Example E) is kept to 1.5°C or less, preventing heat from building up inside the diaper and preventing excessive temperature rise. This makes it less likely that the diaper 1 will cause discomfort to the wearer.

[0130] Furthermore, if the temperature measured when the temperature measurement position was covered by the pants-type diaper of Comparative Example B, which does not use an aqueous nonwoven fabric, is defined as the "third temperature," the difference between the third temperature (Comparative Example B) 60 minutes after the start of power supply and the first temperature (Example A) 60 minutes after the start of power supply was 1°C or more. Specifically, on the front side (ventral side) of the sweating mannequin, the third temperature after 60 minutes was 35.3°C, while the first temperature after 60 minutes was 34.2°C, meaning that Comparative Example B was 1.1°C higher than Example A (see FIG. 12A). Similarly, on the back side (dorsal side) of the sweating mannequin, the third temperature after 60 minutes was 35.5°C, while the first temperature after 60 minutes was 34.3°C, meaning that Comparative Example B was 1.2°C higher than Example A (see FIG. 12B).

[0131] As described above, the diaper 1 of this embodiment (Example A) exhibits a temperature rise at least 1°C lower after 60 minutes than the pants-type diaper (Comparative Example B) that does not use a hydrophilic nonwoven fabric. As described above, the only difference between the pants-type diaper of Comparative Example B and the pants-type diaper of Example A (Diaper 1) is the presence or absence of a hydrophilic nonwoven fabric. This demonstrates that the provision of a hydrophilic nonwoven fabric, which facilitates the evaporation of moisture such as sweat into the atmosphere, makes it easier to suppress temperature rise compared to pants-type disposable diapers made of conventional hydrophobic nonwoven fabric.

[0132] The behavior of the diaper 1 of Example A and the pants-type diaper of Comparative Example B during temperature rise also differs. In FIG. 12A, the first temperature (Example A) is 33.1°C at the start of measurement and rises to 33.8°C after 30 minutes. That is, the rate of temperature rise of the first temperature per unit time calculated based on the temperature measurement data for 29 minutes from the start of measurement is (33.8-33.1) x 60 / 29 ≒ 1.45°C / h. On the other hand, the third temperature (Example E) is 33.4°C at the start of measurement and rises to 34.8°C after 30 minutes. That is, the rate of temperature rise of the third temperature per unit time calculated based on the temperature measurement data for 29 minutes from the start of measurement is (34.8-33.4) x 60 / 29 ≒ 2.90°C / h. Therefore, 30 minutes after the start of power supply, the temperature rise rate per unit time of the front first temperature is 0.5 times (=1.45 / 2.90) the temperature rise rate per unit time of the third temperature.

[0133] Similarly, in FIG. 12B , the first temperature (Example A) is 33.2°C at the start of measurement and rises to 33.9°C after 30 minutes. That is, the temperature rise rate of the first temperature per unit time calculated based on the temperature measurement data for 29 minutes from the start of measurement is (33.9-33.2) x 60 / 29 ≒ 1.45°C / h. On the other hand, the third temperature (Example E) is 33.4°C at the start of measurement and rises to 35.1°C after 30 minutes. That is, the temperature rise rate of the third temperature per unit time calculated based on the temperature measurement data for 29 minutes from the start of measurement is (35.1-33.4) x 60 / 29 ≒ 3.52°C / h. Therefore, the temperature rise rate per unit time of the first temperature on the rear side 30 minutes after the start of power supply is 0.42 times (=1.45 / 3.52) the temperature rise rate per unit time of the third temperature.

[0134] These results show that the diaper 1 of this embodiment (Example A) had a temperature rise rate of less than half that of a pants-type diaper (Comparative Example B) that did not use a hydrophilic nonwoven fabric after 30 minutes. This also confirms that the diaper 1 of this embodiment is less susceptible to temperature rise inside the pants than conventional pants-type diapers. Furthermore, the diaper 1 showed a low temperature rise for approximately 30 minutes after the start of measurement of the pants' temperature, demonstrating its excellent feel immediately after donning.

[0135] Furthermore, the temperature measurement positions (predetermined positions) in this pants temperature measurement experiment were located at positions on both the front (ventral side) and rear (back side) sides that were covered by the waistline member 20 (front waistline portion 30, rear waistline portion 40) (see FIGS. 11A and 11B). In other words, the temperatures were measured at positions on the wearer's body that were covered by the waistline member 20 when the diaper 1 was worn. It was revealed that the temperature rise at the positions covered by the waistline member 20 was reduced in the diaper 1 compared to the diaper of Comparative Example B. Therefore, wearing the diaper 1 helps to prevent the temperature inside the pants from becoming excessively high or the pants from becoming stuffy in the front and rear waist regions where sweating is likely to occur. This makes it less likely that the wearer will feel uncomfortable.

[0136] As described above, it has been revealed that the diaper 1 of this embodiment promotes moisture absorption and evaporation due to the action of the hydrophilic nonwoven fabric provided in the waistband member 20, thereby suppressing an increase in the internal temperature (temperature inside the pants) of the diaper 1. Therefore, the diaper 1 of this embodiment makes it possible to realize a pants-type absorbent article that is less likely to cause discomfort to the wearer.

[0137] === Second Embodiment === In the second embodiment, a pants-type diaper 2 (hereinafter also referred to as "diaper 2") having a configuration partially different from that of the first embodiment will be described. Fig. 13A is a plan view of the diaper 2 in an unfolded and stretched state. Fig. 13B is a schematic cross-sectional view taken along line BB in Fig. 13A. Note that the directions (e.g., vertical direction, horizontal direction, etc.) in Figs. 13A and 13B are the same as those defined in the first embodiment.

[0138] The diaper 2 of the second embodiment comprises a liquid-absorbent main body 10 and a waistband member 20 disposed on the non-skin side of the absorbent main body 10. However, in the diaper 2, the front waistband portion 30 and the rear waistband portion 40 are integrally formed. In other words, the diaper 2 is a so-called two-piece disposable diaper, which is formed by the absorbent main body 10 as an inner body and the waistband member 20 as an outer body.

[0139] When the diaper 2 in the unfolded state shown in Fig. 13A is formed into a pants-type diaper, the absorbent main body 10 and the waistline member 20 are folded in half at a longitudinal center position CL. In this folded state, the opposing front waistline portion 30 and rear waistline portion 40 are joined and connected to each other at the side portions 30sw and 40sw on both the left and right sides to form a pair of side joining portions 50, 50. This results in a pants-type diaper 2 having a waistline opening BH and a pair of leg openings LH, LH, similar to Fig. 1.

[0140] In the diaper 2, the basic structure and function of the absorbent main body 10 are substantially the same as those of the diaper 1 of the first embodiment, and therefore description thereof will be omitted. In Fig. 13A, in the crotch region including the center position CL in the vertical direction (the longitudinal direction of the absorbent main body 10), the absorbent main body 10 has a portion where the width in the left-right direction is wider than the width in the left-right direction of the waistline member 20. Therefore, when the diaper 1 is worn, both left-right edge portions (edges) of the absorbent main body 10 come into contact with the wearer's legs in the region near the crotch region.

[0141] In the diaper 2, the portion of the waistline member 20 that is forward of a central position CL in the vertical direction (longitudinal direction of the absorbent main body 10) is the front waistline section 30, and the portion that is rearward of the central position CL is the rear waistline section 40. The waistline member 20 has a skin-side sheet 21, a non-skin-side sheet 22 laminated adjacent to the non-skin-side of the skin-side sheet 21, and waistline elastic members 35, 45 arranged between the skin-side sheet 21 and the non-skin-side sheet 22 in the thickness direction (see FIG. 13B).

[0142] The skin-side sheet 21 is a hydrophobic nonwoven fabric similar to the skin-side sheet 31 of the diaper 1. The non-skin-side sheet 22 is a hydrophilic nonwoven fabric similar to the non-skin-side sheet 32 ​​of the diaper 1. That is, the non-skin-side sheet 22 is made of a nonwoven fabric that is more hydrophilic than the skin-side sheet 21. The waist-surrounding elastic members 35, 45 are made of rubber thread or the like, similar to the diaper 1, and are attached between the skin-side sheet 21 and the non-skin-side sheet 22 in a state stretched in the left-right direction.

[0143] Like the diaper 1 of the first embodiment, the diaper 2 of the second embodiment can absorb moisture from the wearer's skin and efficiently evaporate the absorbed moisture into the atmosphere. Specifically, the hydrophobic nonwoven fabric (skin-side sheet 21) arranged to contact the wearer's skin contracts in response to the contraction of the waist elastic members 35, 45, thereby reducing the interfiber distance between the fibers constituting the hydrophobic nonwoven fabric. This facilitates capillary action, absorbing moisture such as sweat from the wearer's skin. When the waist elastic members 35, 45 expand, the contact area between the hydrophobic nonwoven fabric (skin-side sheet 21) and the hydrophilic nonwoven fabric (non-skin-side sheet 22) increases, allowing moisture to migrate from the less hydrophilic hydrophobic nonwoven fabric to the more hydrophilic hydrophilic nonwoven fabric. The migrated moisture evaporates into the atmosphere from the interface between the hydrophilic nonwoven fabric and the atmosphere. This efficient release of moisture from the wearer's skin into the atmosphere reduces discomfort to the wearer.

[0144] Furthermore, like the diaper 1, the diaper 2 is also capable of efficiently evaporating moisture absorbed from the wearer's skin into the atmosphere, thereby suppressing the rise in temperature inside the pants when worn, as explained in Fig. 12. Therefore, the wearer is less likely to experience discomfort when wearing the diaper 2.

[0145] ===Third Embodiment=== In the third embodiment, a pants-type diaper 3 (hereinafter also referred to as "diaper 3") partially differing in configuration from the first and second embodiments will be described. Fig. 14A is a plan view of the diaper 3 in an unfolded and stretched state. Fig. 14B is a schematic cross-sectional view taken along line CC in Fig. 14A. Note that the directions (e.g., vertical and horizontal directions) in Figs. 14A and 14B are the same as those defined in the first embodiment.

[0146] The diaper 3 of the third embodiment has a liquid-absorbent main absorber 10 and a waistline member 20 arranged on the non-skin side of the absorber 10. However, in the diaper 3, as shown in Fig. 14B, part of the members constituting the front waistline portion 30 (skin-side sheet 21) and part of the members constituting the rear waistline portion 40 (skin-side sheet 21) are integrally formed. Hereinafter, a diaper having such a structure will also be referred to as a simple three-piece disposable diaper.

[0147] When the diaper 3 in the unfolded state shown in Fig. 14A is formed into a pants-type diaper, the absorbent main body 10 and the waist member 20 are folded in half at a longitudinal center position CL. In this folded state, the opposing front waist portion 30 and rear waist portion 40 are joined and connected to each other at the side portions 30sw and 40sw on both the left and right sides to form a pair of side joining portions 50, 50. This results in a pants-type diaper 3 having a waist opening BH and a pair of leg openings LH, LH, similar to Fig. 1.

[0148] In the diaper 3, the basic structure and function of the absorbent body 10 are substantially the same as those of the diaper 1 of the first embodiment, and therefore a description thereof will be omitted.

[0149] In the diaper 3, the portion of the waistline member 20 that is forward of a central position CL in the vertical direction (longitudinal direction of the absorbent main body 10) is the front waistline section 30, and the portion that is rearward of the central position CL is the rear waistline section 40. The front waistline section 30 has a skin-side sheet 21 that extends from one end (ventral side) in the vertical direction to the other end (dorsal side) on the skin side in the thickness direction, a non-skin-side sheet 32 ​​that is laminated adjacent to the non-skin side of the skin-side sheet 21 on the front side (ventral side) in the vertical direction, and a waistline elastic member 35 that is arranged between the skin-side sheet 21 and the non-skin-side sheet 32 ​​in the thickness direction. The rear waistline portion 40 has a skin-side sheet 21 common to the front waistline portion 30, a non-skin-side sheet 42 laminated adjacent to the non-skin-side of the skin-side sheet 21 on the rear side (back side) in the vertical direction, and a waistline elastic member 45 arranged between the skin-side sheet 21 and the non-skin-side sheet 42 in the thickness direction.

[0150] The skin-side sheet 21 is made of a hydrophobic nonwoven fabric similar to the skin-side sheet 31 of the diaper 1. The non-skin-side sheets 32, 42 are made of a hydrophilic nonwoven fabric similar to the non-skin-side sheets 32, 42 of the diaper 1. That is, the non-skin-side sheets 32, 42 are made of a nonwoven fabric that is more hydrophilic than the skin-side sheet 21. The waist-surrounding elastic members 35, 45 are made of rubber thread or the like similar to the diaper 1, and are attached between the skin-side sheet 21 and the non-skin-side sheets 32, 42 in a state stretched in the left-right direction.

[0151] Like the diaper 1 of the first embodiment, the diaper 3 of the third embodiment can absorb moisture from the wearer's skin and efficiently evaporate the absorbed moisture into the atmosphere. Specifically, the hydrophobic nonwoven fabric (skin-side sheet 21) arranged to contact the wearer's skin contracts in response to the contraction of the waist elastic members 35, 45, thereby reducing the interfiber distance between the fibers constituting the hydrophobic sheet. This facilitates capillary action, absorbing moisture such as sweat from the wearer's skin. When the waist elastic members 35, 45 expand, the contact area between the hydrophobic nonwoven fabric (skin-side sheet 21) and the hydrophilic nonwoven fabric (non-skin-side sheets 32, 42) increases, allowing moisture to migrate from the less hydrophobic nonwoven fabric to the more hydrophilic nonwoven fabric. The migrated moisture evaporates into the atmosphere from the interface between the hydrophilic nonwoven fabric and the atmosphere. This efficient release of moisture from the wearer's skin into the atmosphere reduces discomfort to the wearer.

[0152] Furthermore, like Diaper 1 and Diaper 2, Diaper 3 is also capable of efficiently evaporating moisture absorbed through the wearer's skin into the atmosphere, thereby suppressing the rise in temperature inside the pants when worn, as explained in Fig. 12. Therefore, wearing Diaper 3 can reduce discomfort to the wearer.

[0153] ===Other embodiments=== Although the embodiments of the present invention have been described above, the above embodiments are intended to facilitate understanding of the present invention and are not intended to limit the present invention. Furthermore, the present invention may be modified or improved without departing from the spirit thereof, and it goes without saying that the present invention includes equivalents thereof. [Explanation of symbols]

[0154] 1 Diaper (pants-type absorbent article) (first embodiment), 2 Diaper (pants-type absorbent article) (second embodiment), 3 Diaper (pants-type absorbent article) (third embodiment), 10. Absorbent body; 11 absorbent core, 11b core wrap sheet, 11c constricted portion, 12 top sheet, 13 back sheet, 13a liquid impermeable sheet, 13b exterior sheet, 15 leak-proof wall portion, 16 leak-proof wall elastic member, 17 leg-around elastic member, 20 girth member, 21 Skin side sheet (hydrophobic nonwoven fabric), 22 Non-skin side sheet (hydrophilic nonwoven fabric), 30 Front waistband, 30sw side, 31 Skin side sheet (hydrophobic nonwoven fabric), 32 Non-skin side sheet (hydrophilic nonwoven fabric), 32f Folded portion, 32h hole, 32hs side wall, 32hp protrusion, 32s non-skin side surface, 35 waist elastic member; 36 Skin-facing sheet, 40 rear waistband portion, 40b crotch region, 40sw side, 41 Skin side sheet (hydrophobic nonwoven fabric), 42 non-skin side sheet (hydrophilic nonwoven fabric), 42f folded part, 42h opening, 45 waist elastic member; 46 skin-facing sheet, 47 curved elastic member, 50 side joints, 60 welds, 60s welded joint pair, BH waist opening, LH leg opening, CL Center position (vertical, longitudinal)

Claims

1. having an up-down direction, a left-right direction, and a front-rear direction which intersect with one another, A pants-type absorbent article having a liquid-absorbing absorbent main body and a waistband member provided on a side closer to the wearer's skin than the absorbent main body, In at least a part of the region of the waistband member, a hydrophobic nonwoven fabric placed closest to the skin; a hydrophilic nonwoven fabric laminated adjacent to the non-skin side of the hydrophobic nonwoven fabric and having higher hydrophilicity than the hydrophobic nonwoven fabric; an elastic member provided between the hydrophobic nonwoven fabric and the hydrophilic nonwoven fabric, the elastic member stretching in the left-right direction; It has A pants-type absorbent article, characterized in that the average fiber density of the hydrophobic nonwoven fabric is higher than the average fiber density of the hydrophilic nonwoven fabric.

2. A pants-type absorbent article as described in claim 1, A pants-type absorbent article, characterized in that it has a portion where the hydrophobic nonwoven fabric and the hydrophilic nonwoven fabric are joined at least around the periphery of the elastic member.

3. A pants-type absorbent article as described in claim 2, A pants-type absorbent article, characterized in that the hydrophobic nonwoven fabric and the hydrophilic nonwoven fabric are bonded together via the elastic member using an adhesive.

4. A pants-type absorbent article according to any one of claims 1 to 3, The waistband member has a front waistband member and a rear waistband member, a pair of side joining portions that join the front waistline member and the rear waistline member at both left and right end portions; A pants-type absorbent article, characterized in that the at least a portion of the waistband member is provided in any part between the pair of side joining portions in the left-right direction.

5. A pants-type absorbent article according to claim 4, A pants-type absorbent article, characterized in that the at least a portion of the waistband member is provided on the rear waistband member.

6. A pants-type absorbent article according to any one of claims 1 to 5, A pants-type absorbent article, characterized in that at least a part of the hydrophilic nonwoven fabric is disposed on the side of the waistband member closest to the wearer's skin.

7. A pants-type absorbent article according to any one of claims 1 to 6, The pants-type absorbent article is characterized in that the waistband member has a two-layer structure in which one layer of the hydrophilic nonwoven fabric and one layer of the hydrophobic nonwoven fabric are laminated.

8. A pants-type absorbent article according to any one of claims 1 to 7, A pants-type absorbent article, characterized in that the hydrophobic nonwoven fabric has a plurality of compression portions that compress the hydrophobic nonwoven fabric in the thickness direction.

9. A pants-type absorbent article according to any one of claims 1 to 8, the hydrophilic nonwoven fabric has a plurality of openings penetrating the hydrophilic nonwoven fabric in a thickness direction, A pants-type absorbent article, characterized in that the average thickness of the hydrophilic nonwoven fabric is greater than the average thickness of the hydrophobic nonwoven fabric.

10. A pants-type absorbent article according to claim 9, A pants-type absorbent article, characterized in that the outer edges of the perforations on the skin side of the hydrophilic nonwoven fabric have convex portions that are convex toward the skin side.

11. A pants-type absorbent article according to any one of claims 9 or 10, having an up-down direction, a left-right direction, and a front-rear direction which intersect with one another, an elastic member stretchable in the left-right direction between the hydrophobic nonwoven fabric and the hydrophilic nonwoven fabric; A pants-type absorbent article, characterized in that there is a portion where the opening and the elastic member overlap.

12. A pants-type absorbent article according to any one of claims 9 to 11, having an up-down direction, a left-right direction, and a front-rear direction which intersect with one another, an elastic member stretchable in the left-right direction between the hydrophobic nonwoven fabric and the hydrophilic nonwoven fabric; A pants-type absorbent article, characterized in that a plurality of the openings are provided between two of the elastic members arranged adjacent to each other in the vertical direction.

13. A pants-type absorbent article according to any one of claims 8 to 12, A pants-type absorbent article, wherein the hydrophobic nonwoven fabric does not have through-holes that penetrate the hydrophobic nonwoven fabric in the thickness direction.

14. A pants-type absorbent article according to any one of claims 1 to 13, A pants-type absorbent article, characterized in that the average basis weight of the hydrophilic nonwoven fabric is greater than the average basis weight of the hydrophobic nonwoven fabric.

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