Pants-type absorbent article

Abstract

To provide a pants-type absorbent article that has crotch elastic members and looks like underwear. [Solution] A pants-type absorbent article (1) having an absorbent core (11) and a waistband member (20), which has a crotch elastic member (40) arranged closer to the skin than the absorbent core (11), and the waistband member (20) has waistband elastic members (24, 25), and a crotch sheet (23) covering the crotch elastic member (40) from the closer to the skin and located closest to the skin at the longitudinal center position (CL) is continuous in the longitudinal direction between the rear end (5feb) of the side joint portion (5) arranged on the front side and the front end (5beb) of the side joint portion (5) arranged on the rear side, and has a crotch layer (CA) that contacts the crotch elastic member (40) from the closer to the skin, and a waistband layer (WA) that contacts the waistband elastic member (24) from the closer to the skin, and the light transmittance of the crotch layer (CA) is smaller than that of the waistband layer (WA).

Description

[Technical Field]

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

[0002] Conventionally, in a pants-type absorbent article (such as a pants-type diaper) having an absorbent main body and waistband members arranged so as to cover the front and rear of the absorbent main body from the non-skin side, a technique has been known in which an elastic member (crotch elastic member) that stretches along the longitudinal direction of the absorbent main body is provided to improve the fit of the absorbent main body in the crotch area. For example, Patent Document 1 discloses a technique related to a diaper (absorbent article) that includes leg elastics 7A that stretch along the width direction and a central elastic member 60 (corresponding to the crotch elastic member) that stretches along the longitudinal direction, and that prevents the absorbent main body 40 from moving away from the wearer's skin due to contraction of the central elastic member 60, thereby improving wearing comfort. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2010-279612 Summary of the Invention [Problem to be solved by the invention]

[0004] If the crotch portion of an absorbent article equipped with such crotch elastic members has seams in the material or if the crotch elastic members, which are not normally found in underwear, are visible, the user (wearer) may be more likely to recognize the difference from underwear and feel uncomfortable. Furthermore, the wearer may be more likely to realize that they are wearing a diaper, not underwear, which may cause psychological stress.

[0005] The present invention has been made in view of the above-mentioned problems, and an object of the present invention is to provide a pants-type absorbent article that has crotch elastic members and looks like underwear. [Means for solving the problem]

[0006] The main invention for achieving the above object is a pants-type absorbent article having, in an unfolded and stretched state, longitudinal, left-right, and thickness directions that intersect with one another, an absorbent main body having an absorbent core, and a waistband member having a front waistband and a rear waistband, the front waistband and the rear waistband being joined to each other at both ends in the left-right direction by a pair of side joining parts, the article having crotch elastic members that are located closer to the skin than the absorbent core and stretch along the longitudinal direction, the waistband member having waist elastic members that stretch in the left-right direction, covering the crotch elastic members from the far side and positioned closest to the skin at a central position in the longitudinal direction, a crotch sheet that is continuous in the longitudinal direction between the rear end of the side joint provided in the front waistline portion and the front end of the side joint provided in the rear waistline portion, and a crotch layer that contacts the crotch elastic member from the non-skin side in the thickness direction and constitutes at least a part of the non-skin side of the pants-type absorbent article, and a waist layer that contacts the waist elastic member from the non-skin side in the thickness direction and constitutes at least a part of the non-skin side of the pants-type absorbent article, wherein the light transmittance of the crotch layer is smaller than the light transmittance of the waistline layer. Other features of the present invention will become apparent from the description of this specification and the accompanying drawings. [Effects of the Invention]

[0007] According to the present invention, it is possible to provide a pants-type absorbent article that has crotch elastic members and looks like underwear. [Brief explanation of the drawings]

[0008] [Figure 1] 1 is a front view of a pants-type disposable diaper 1 as seen from the ventral side. [Figure 2] 1 is a plan view of a pants-type disposable diaper 1 in an unfolded and stretched state. [Figure 3]3 is a schematic cross-sectional view of the pants-type disposable diaper 1 taken along the CC line in FIG. 2. FIG. [Figure 4] Fig. 4A is a plan view of the absorbent main body 10 as seen from the skin side, and Fig. 4B is a schematic cross-sectional view of the absorbent main body 10 at a central position CL in the longitudinal direction. [Figure 5] 1 is a diagram schematically illustrating a cross-sectional state of a diaper 1 in a pants-type state as viewed from one side in the left-right direction. [Figure 6] FIG. 2 is a diagram illustrating the joining of the absorbent body 10 and the waistline member 20 (outer layer member 20). [Figure 7] FIG. 7 is a schematic cross-sectional view taken along the line A1-A1 in FIG. 6. [Figure 8] Fig. 8A is a diagram showing an example of a diaper 1 having letters on the crotch layer CA, and Fig. 8B is a diagram showing an example of a diaper 1 having a design and a pattern on the crotch layer CA. [Figure 9] 1A and 1B are a plan view and a cross-sectional view of a modified diaper 1 in an unfolded and stretched state. [Figure 10] 10A to 10C are three-view diagrams illustrating the configuration of a diaper 2 according to a second embodiment. [Figure 11] 10A to 10C are three-view diagrams illustrating the configuration of a diaper 3 according to a third embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0009] At least the following matters will become clear from the description of this specification and the accompanying drawings. (Aspect 1) A pants-type absorbent article having longitudinal, lateral, and thickness directions that intersect with one another in an unfolded and stretched state, an absorbent main body having an absorbent core, and a waistband member having a front waistband and a rear waistband, the front waistband and the rear waistband being joined to one another at both ends in the lateral direction by a pair of side joining parts, the pants-type absorbent article having crotch elastic members that are located closer to the skin than the absorbent core and stretch along the longitudinal direction, the waistband member having waist elastic members that stretch in the lateral direction, and a crotch sheet that covers the crotch elastic members from the far side and is located closest to the skin at a central position in the longitudinal direction. a crotch layer that contacts the crotch elastic member from the non-skin side in the thickness direction and constitutes at least a part of the non-skin side of the pants-type absorbent article, and a waist layer that contacts the waist elastic member from the non-skin side in the thickness direction and constitutes at least a part of the non-skin side of the pants-type absorbent article, wherein the crotch sheet is continuous in the longitudinal direction between the rear end of the side joint portion provided in the front waist portion and the front end of the side joint portion provided in the rear waist portion, and the pants-type absorbent article has a waist layer that contacts the waist elastic member from the non-skin side in the thickness direction and constitutes at least a part of the non-skin side of the pants-type absorbent article, and

[0010] According to the pants-type absorbent article of aspect 1, the crotch elastic members are less visible than the waist elastic members when viewed from the outside (non-skin side). The crotch sheet constituting the crotch portion has no unnecessary seams between the lower end (rear end in the longitudinal direction) of the front side joint and the lower end (front end in the longitudinal direction) of the rear side joint. In other words, the seams of the materials and the crotch elastic members are less noticeable in the crotch portion. Therefore, the inclusion of the crotch elastic members improves the fit in the crotch portion, while realizing a pants-type diaper that has an underwear-like appearance.

[0011] (Aspect 2) The pants-type absorbent article of aspect 1, wherein the difference between the number of sheet members stacked on the side away from the skin of the crotch elastic members at the rear end of the side joint in the front waistband or the front end of the side joint in the rear waistband in the longitudinal direction and the number of sheet members stacked on the side away from the skin of the crotch elastic members at a position overlapping with the crotch elastic members in the longitudinal direction is one or less.

[0012] According to the pants-type absorbent article of aspect 2, the difference in the number of layers of material between the rear end (front end) of the side joint and the crotch elastic member in the longitudinal direction of the front waistband (rear waistband) is minimized, and the step in the thickness direction is less noticeable compared to when the difference in the number of layers is two or more. Therefore, the step is less noticeable when viewed from the outside (non-skin side), and the article can have a more underwear-like appearance.

[0013] (Aspect 3) A pants-type absorbent article according to aspect 1 or 2, having a crotch elastic region defined by the crotch elastic member, wherein the width of the crotch elastic region in the left-right direction is smaller than the distance between the one end of the crotch elastic region and the one end of the absorbent core.

[0014] According to the pants-type absorbent article of the third aspect, when the absorbent core is deformed into a convex shape toward the skin due to the stretchability of the crotch elastic regions, the portion where the crotch elastic regions are provided tends to stand up high toward the skin, making it easier to fit around the wearer's excretory opening. Furthermore, because the proportion of the area of ​​the crotch elastic regions in the absorbent core is not excessively large, wrinkles formed in the absorbent core when the crotch elastic regions contract are less noticeable. This results in a more underwear-like appearance.

[0015] (Aspect 4) The pants-type absorbent article according to any one of Aspects 1 to 3, wherein the color of the crotch elastic members and the color of the crotch sheet are similar to each other.

[0016] In the pants-type absorbent article of aspect 4, if the color of the crotch sheet provided closest to the skin of the crotch layer is similar to the color of the crotch elastic members, when the two are stacked in the thickness direction and viewed from the non-skin side, it is difficult to distinguish the difference between the color of the crotch elastic members and the color of the crotch sheet, making it difficult for the user to recognize the crotch elastic members that are located closer to the skin than the crotch sheet. Therefore, the crotch elastic members are less noticeable, allowing for an appearance that resembles underwear.

[0017] (Aspect 5) A pants-type absorbent article according to any one of aspects 1 to 4, having a main body joint that joins the absorbent main body and the waistband member, and having a portion of the main body joint that overlaps with the crotch elastic member when viewed in the thickness direction where no adhesive is provided.

[0018] In the pants-type absorbent article of aspect 5, gaps in the adhesive applied linearly in an Ω pattern or spiral pattern at the main body joining portion joining the absorbent main body and the waistband member may be left with no adhesive. In such adhesive-free areas, the sheet members stacked in the thickness direction are less likely to adhere to each other, and the light transmittance is likely to be lower than when they are in close contact. Therefore, the crotch elastic members are less visible, making the article appear more like underwear.

[0019] (Aspect 6) The pants-type absorbent article according to any one of aspects 1 to 5, wherein the sheet member arranged closest to the skin of the absorbent main body is discontinuous between the center portion and both side portions in the left-right direction.

[0020] In the pants-type absorbent article of aspect 6, when the crotch elastic members contract, wrinkles may occur in the sheet (elastic member cover sheet) laminated on the non-skin side of the crotch elastic members in the left-right central portion. However, because the sheets (side sheets) arranged on both left and right sides of the central sheet are discontinuous with the central sheet, even if wrinkles form in the central sheet, the influence of the wrinkles is less likely to be transmitted from the central sheet to the sheets arranged on both sides. This prevents wrinkles from forming over a wide area in the crotch region. Therefore, wrinkles that occur in the crotch region when worn are less noticeable, making the article appear more like underwear.

[0021] (Aspect 7) A pants-type absorbent article according to any one of aspects 1 to 6, wherein the width of the sheet member that is arranged closest to the skin side of the absorbent main body and that overlaps with the crotch elastic member in the central portion in the left-right direction is smaller than the maximum width of the absorbent core.

[0022] In the pants-type absorbent article of aspect 7, the contraction of the crotch elastic members may cause wrinkles to form in the central sheet (elastic member cover sheet), and the wider the central sheet, the more likely it is that larger wrinkles will form. By making the width of the central sheet narrower than at least the maximum width of the absorbent core, it is possible to prevent excessively large wrinkles from forming in the central sheet. Therefore, wrinkles that form in the crotch area when worn are less noticeable, making the article appear more like underwear.

[0023] (Aspect 8) A pants-type absorbent article according to any one of aspects 1 to 7, wherein the width of the sheet member that is arranged closest to the skin side of the absorbent main body and that overlaps with the crotch elastic member in the central portion in the left-right direction is smaller than the minimum width of the absorbent core.

[0024] According to the pants-type absorbent article of aspect 8, by making the width of the central sheet (elastic member cover sheet) narrower than the minimum width of the absorbent core, it becomes easier to prevent large wrinkles from forming in the central sheet, which makes wrinkles that occur in the crotch area when worn less noticeable and makes the article look more like underwear.

[0025] (Aspect 9) A pants-type absorbent article according to any one of aspects 1 to 8, wherein, among the sheet members arranged on the farthest side of the absorbent main body, the sheet member overlapping with the crotch elastic member in the central portion in the left-right direction has portions at both ends in the left-right direction where no adhesive is provided.

[0026] According to the pants-type absorbent article of the ninth aspect, even if wrinkles are formed in the central sheet (elastic member cover sheet) due to contraction of the crotch elastic members, the dry edges on both sides in the left and right directions prevent the influence of the wrinkles from being transmitted outward in the left and right directions. This makes it difficult for the range of wrinkles formed in the waistband member to spread in the left and right directions, making the wrinkles less noticeable in the crotch area. Therefore, the appearance when worn can be more easily seen as underwear.

[0027] (Aspect 10) The pants-type absorbent article according to any one of aspects 1 to 9, wherein the waist elastic members and the crotch elastic members do not intersect when viewed in the thickness direction.

[0028] In the pants-type absorbent article of aspect 10, the stretchable force of the crotch elastic members in the longitudinal direction and the stretchable force of the waist elastic members in the left-right direction are less likely to interfere with each other, making it easier for the stretchable force of the crotch elastic members to act in the crotch area. This makes it easier for the absorbent main body to deform convexly toward the skin, further improving the fit when worn. Furthermore, since the stretchable force in the longitudinal direction and the stretchable force in the left-right direction are less likely to interfere with each other in the crotch area, irregular wrinkles are less likely to form, making the article more likely to look like underwear.

[0029] (Aspect 11) 11. The pants-type absorbent article according to any one of aspects 1 to 10, wherein the absorbent core does not have a low basis weight region in the central part in the left-right direction, the region having a basis weight lower than that of other regions.

[0030] According to the pants-type absorbent article of aspect 11, since the absorbent core does not have a low basis weight region in the left-right central portion, the stretching force of the crotch elastic members tends to act uniformly, and the absorbent core tends to easily undergo a clean convex deformation, thereby further improving the fit when worn.

[0031] (Aspect 12) A pants-type absorbent article according to any one of aspects 1 to 11, wherein in the thickness direction, there is a portion where the sheet member arranged adjacent to the skin side of the crotch elastic member and the sheet member arranged furthest from the skin side are not joined.

[0032] According to the pants-type absorbent article of aspect 12, the sheet (back sheet) arranged adjacent to the skin side of the crotch elastic member in the thickness direction and the sheet (inner layer sheet) arranged on the non-skin side thereof have portions that are not joined to each other, thereby preventing wrinkles formed in the skin side sheet from being transmitted to the non-skin side sheet. This makes it less likely for wrinkles to form in the sheet arranged on the non-skin side (waist member). Furthermore, in the portions where the skin side sheet and the non-skin side sheet are not joined to each other across the crotch elastic member, the two sheets are less likely to be in close contact with each other in the thickness direction, making the crotch elastic member sandwiched between the two sheet members less visible compared to when they are in close contact with each other in the thickness direction. This allows the article to have an appearance similar to underwear when worn.

[0033] (Aspect 13) A pants-type absorbent article according to any one of aspects 1 to 12, wherein the average basis weight of the first sheet member provided on the non-skin side of the crotch elastic member in the thickness direction is different from the average basis weight of the second sheet member provided on the non-skin side of the first sheet member.

[0034] According to the pants-type absorbent article of aspect 13, sheet members with different basis weights often have different stiffnesses and thicknesses, and are therefore likely to wrinkle differently. Therefore, by stacking a first sheet member and a second sheet member with different basis weights in the thickness direction, it is possible to prevent wrinkles formed in the first sheet member from being directly transmitted to the second sheet member. Furthermore, when a sheet member with a larger basis weight is provided on the non-skin side, the crotch elastic members provided on the non-skin side are less visible when viewed from the non-skin side. This makes the article appear more like underwear.

[0035] (Aspect 14) 14. The pants-type absorbent article according to any one of aspects 1 to 13, wherein the fiber orientation direction of the first sheet member and the fiber orientation direction of the second sheet member intersect with each other.

[0036] According to the pants-type absorbent article of aspect 14, the stretchability of the first sheet member along the longitudinal direction is likely to be different from the stretchability of the second sheet member along the longitudinal direction, and even if wrinkles form in the first sheet member, the likelihood of the formed wrinkles being directly transmitted to the second sheet member can be reduced. Furthermore, since the light transmittance is likely to be lower in the area where multiple fibers intersect compared to when the fibers are arranged parallel to each other, it becomes difficult to see the crotch elastic members through the first and second sheet members, and the crotch elastic members become less noticeable. This makes it easier for the article to look like underwear.

[0037] ===First Embodiment=== The following description will be given taking a pants-type disposable diaper 1 (hereinafter also referred to as "diaper 1") as an example of a pants-type absorbent article according to the present invention. However, the pants-type absorbent article according to the present invention is not limited to the above and can also be used as a sanitary napkin, sanitary shorts, etc.

[0038] <Basic structure of pants-type disposable diaper 1> Fig. 1 is a front view of a pants-type disposable diaper 1 as seen from the ventral side. Fig. 2 is a plan view of the pants-type disposable diaper 1 in an unfolded and stretched state. Fig. 3 is a schematic cross-sectional view of the pants-type disposable diaper 1 taken along the line CC in Fig. 2.

[0039] The unfolded state of the pants-type disposable diaper 1 (diaper 1) refers to the state in which the diaper 1 is opened and laid out flat by separating a pair of side seams 5 provided on both sides of the diaper 1. The stretched state of the diaper 1 refers to the state in which the diaper 1 is stretched to the extent that wrinkles in the diaper 1 are no longer visible. Specifically, this refers to the state in which the diaper 1 is stretched until the dimensions of each component constituting the diaper 1 (e.g., the top sheet 12 and inner layer sheet 23 described below) match or are close to the dimensions of the component alone.

[0040] As shown in Fig. 1, the diaper 1 has a vertical direction, a horizontal direction, and a front-to-back direction (directions passing through the paper in Fig. 1) that are perpendicular to one another, and has a waist opening BH and a pair of leg openings 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 abdomen, and the rear side corresponds to the wearer's back.

[0041] In the unfolded state shown in FIG. 2, the diaper 1 has a longitudinal direction, a left-right direction, and a thickness direction (a direction passing through the paper in FIG. 2) that intersect with one another. The left-right direction in the unfolded state of FIG. 2 is the same as the left-right direction in the pants-type state of FIG. 1. The longitudinal direction in the unfolded state is a direction along the up-down direction in the pants-type state. One side in the longitudinal direction corresponds to the front side (ventral side), and the other side corresponds to the rear side (dorsal side). As shown in FIG. 3, the thickness direction is the direction in which the materials constituting the diaper 1 are layered. 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.

[0042] The diaper 1 has an absorbent main body 10 and an exterior member 20 provided on the side away from the wearer's skin than the absorbent main body 10. As will be described in detail later, the absorbent main body 10 and the exterior member 20 are bonded in the thickness direction using an adhesive such as a hot melt adhesive. Cover sheets 31, 32 may also be provided to cover both longitudinal ends of the absorbent main body 10 from the skin side (see FIG. 3). This prevents the edges of the absorbent main body 10 from digging into the wearer's body and prevents the absorbent main body 10 from opening open.

[0043] The outer layer member 20 is a portion that is positioned around the waist of the wearer when the diaper 1 is worn. Hereinafter, the outer layer member 20 will also be referred to as the "waist member 20." As shown in FIG. 2 , when the diaper 1 is in an unfolded and stretched state, the portion of the waist member 20 that is forward (toward the ventral side) of a longitudinal center position CL of the diaper 1 will be referred to as the "front waist portion 20f," and the portion that is rearward (toward the dorsal side) of the longitudinal center position CL of the diaper 1 will be referred to as the "rear waist portion 20b." When the diaper 1 is folded in half at the longitudinal center position CL from the unfolded state shown in FIG. 2 , the front waist portion 20f and the rear waist portion 20b, which are opposed in the thickness direction (front-rear direction), are joined at their lateral sides by a pair of side joining portions 5, thereby forming the pants-type diaper 1 as shown in FIG. 1 . Examples of joining methods using the side joining portions 5 include thermal welding, ultrasonic welding, and adhesive joining.

[0044] (Absorbent body 10) Fig. 4A is a plan view of the absorbent main body 10 as seen from the skin side. Fig. 4B is a schematic cross-sectional view of the absorbent main body 10 at a longitudinal center position CL. The absorbent main body 10 includes an absorbent core 11 that absorbs and retains excretory liquids such as urine, a liquid-permeable top sheet 12 (e.g., nonwoven fabric) arranged closer to the skin than the absorbent core 11, a liquid-impermeable back sheet 13 (e.g., a resin film such as polyethylene or polypropylene) arranged closer to the skin than the absorbent core 11, a liquid-permeable intermediate sheet 15 (e.g., nonwoven fabric) arranged between the top sheet 12 and the absorbent core 11, a pair of side sheets 16, and an elastic member cover sheet 17.

[0045] The absorbent core 11 absorbs and retains excreted liquids such as urine. The surface of the absorbent core 11 may be covered with a liquid-permeable core wrap sheet 18 (e.g., tissue paper). The absorbent core 11 is made of a liquid-absorbent material such as water-retentive fibers or superabsorbent polymers (so-called SAPs) molded into a predetermined shape. In this embodiment, as shown in FIG. 4A, the absorbent core 11 has a generally hourglass shape with its longitudinal center narrowed inward in the left-right direction. However, the planar shape of the absorbent core 11 is not particularly limited, and may be, for example, rectangular in plan view. In this embodiment, the width (maximum width) of the absorbent main body 10 in the left-right direction is approximately equal to the width (maximum width) of the absorbent core 11 in the left-right direction.

[0046] A pair of leakage preventing walls 60 is provided along the longitudinal direction on both left and right sides of the absorbent body 10. As shown in FIG. 4B , portions of the side sheets 16 extending from both left and right sides of the non-skin side of the back sheet 13 are folded at multiple locations to form the leakage preventing walls 60 on both left and right sides of the skin side of the top sheet 12. Leak preventing wall elastic members 61 (e.g., rubber threads) are attached to the leakage preventing walls 60 in a stretched state along the longitudinal direction. When the diaper 1 is worn, the stretchability of the leakage preventing wall elastic members 61 causes the leakage preventing walls 60 to stand up against the wearer's skin, thereby blocking body waste.

[0047] The absorbent main body 10 also has a longitudinally stretchable crotch elastic member 40 in its left-right central portion and on the non-skin side in the thickness direction of the absorbent core 11. Specifically, the crotch elastic member 40 of this embodiment is attached in a stretched state along the longitudinal direction between the back sheet 13 provided on the non-skin side of the absorbent core 11 in the thickness direction and the elastic member cover sheet 17 arranged on the non-skin side of the back sheet 13. However, it is sufficient that the crotch elastic member 40 is provided on the non-skin side of the absorbent core 11, and for example, it may be provided between the core wrap sheet 18 (absorbent core 11) and the back sheet 13 on the non-skin side of the absorbent core 11.

[0048] In Fig. 4A, five crotch elastic members 41-45 are arranged longitudinally at intervals in the left-right center of the absorbent main body 10 (absorbent core 11). Hereinafter, the area defined by these five crotch elastic members 40 (41-45) will also be referred to as the "crotch elastic region ER." In other words, as shown by the diagonally slanted area in Fig. 4A, the area surrounded by the crotch elastic member 41 arranged on the most one side in the left-right direction and the crotch elastic member 45 arranged on the most other side is the crotch elastic region ER. However, the number and arrangement of the crotch elastic members 40 are not limited to this.

[0049] When the diaper 1 is worn, the elasticity of the crotch elastic member 40 (crotch elastic region ER) causes the central region of the absorbent core 11 in the left-right direction to deform three-dimensionally so that it becomes convex toward the skin, fitting to the crotch area and excretory opening, thereby achieving good absorbency and fit.

[0050] (Waist member 20) The waistband member 20 (outer member 20) is a sheet member having a shape in which the longitudinal center is constricted inward in the left-right direction. As shown in Figures 2 and 3, the waistband member 20 has a ventral outer layer sheet 21, a dorsal outer layer sheet 22, an inner layer sheet 23, waistband elastic members 24 and 25, and a buttocks elastic member 26.

[0051] The ventral outer layer sheet 21, the back outer layer sheet 22, and the inner layer sheet 23 can be exemplified by flexible sheet members such as nonwoven fabrics. The inner layer sheet 23 forms the outer shape of the waistband member 20 and is a continuous sheet member extending longitudinally from the front side (ventral side) to the back side (dorsal side). The ventral outer layer sheet 21 is disposed closer to the skin than the inner layer sheet 23 and in a portion of the front waistband 20f. The ventral outer layer sheet 21 overlaps the side joints 5 in the longitudinal direction and has the same longitudinal length as the side joints 5 (see FIG. 2). The back outer layer sheet 22 is disposed closer to the skin than the inner layer sheet 23 and in a portion of the rear waistband 20b. The back outer layer sheet 22 overlaps the side joints 5 in the longitudinal direction and extends partially beyond the side joints 5 toward the crotch. In the flattened diaper 1, the ventral outer sheet 21 and the dorsal outer sheet 22 are spaced apart in the longitudinal direction, with the inner sheet 23 exposed to the outside as the non-skin side of the diaper 1 between them.

[0052] The waist elastic members 24, 25 and the buttocks elastic members 26 are elastic members that stretch in the left-right direction, and examples thereof include rubber thread. As shown in FIG. 2, the waist elastic members 24, 25 overlap the side joints 5 in the longitudinal direction. Hereinafter, the waist elastic member located in the front waistline portion 20f may also be referred to as the ventral waistline elastic member 24, and the waist elastic member 25 located in the rear waistline portion 20b may also be referred to as the back waistline elastic member 25. The buttocks elastic member 26 is located on the crotch side in the longitudinal direction (lower in the up-down direction) than the side joints 5. In this embodiment, there are two buttocks elastic members 26, but this number is not particularly limited.

[0053] 2, the buttocks elastic members 26 are cut in the center in the left-right direction and are arranged so as not to overlap with the absorbent core 11. This prevents the absorbent core 11 from contracting in the left-right direction due to the stretchability of the buttocks elastic members 26. Therefore, when the diaper 1 is worn, the absorbent core 11 can be brought into contact with the wearer's buttocks over a wide area, making it easier to achieve good fit and absorbency. However, the buttocks elastic members 26 do not necessarily have to be cut in the center, and may be provided continuously from one end to the other end in the left-right direction.

[0054] The waist elastic members 24, 25 and buttocks elastic members 26 are arranged side by side in the vertical direction between the inner layer sheet 23 and the ventral outer layer sheet 21 or the back outer layer sheet 22, and are attached in a stretched state in the left-right direction. The left-right stretchability of these elastic members 24, 25, 26 allows the waist member 20 to fit the waist and buttocks of the wearer. In the diaper 1, the waist elastic members 24, 25 (and the buttocks elastic member 26 may also be included) are provided continuously from one left-right end to the other, and hereinafter these elastic members 24, 25 (26) are collectively referred to as "left-right elastic members."

[0055] <Appearance of Diaper 1> As explained above, the diaper 1 of this embodiment improves the fit around the crotch area of ​​the wearer by providing the crotch elastic members 40 (crotch elastic region ER) in the left-right central portion of the absorbent main body 10. That is, when the stretching force along the longitudinal direction of the crotch elastic members 40 (crotch elastic region ER) acts on the absorbent core 11, the left-right central portion of the absorbent core 11 is lifted toward the skin and deformed into a convex shape, which is pushed up against the wearer's crotch area (excretory opening such as the vagina) and improves the fit.

[0056] In particular, in the diaper 1, the crotch elastic region ER (crotch elastic member 40) and the transverse elastic members (waist elastic members 24, 25 and buttocks elastic member 26) do not overlap each other. This means that the longitudinal stretching force of the crotch elastic region ER and the transverse stretching force of the transverse elastic members are unlikely to interfere with each other, making it easier for the longitudinal stretching force of the crotch elastic region ER to act in the crotch fitting region IFR. This improves the fit of the absorbent core 11 in the crotch area.

[0057] On the other hand, since the crotch area of ​​typical underwear (pants, shorts, etc.) does not have an elastic member such as rubber thread running in the longitudinal direction equivalent to the crotch elastic member 40, a user (wearer) who visually recognizes the crotch elastic member 40 is likely to recognize the difference from underwear and feel uncomfortable. This also makes it easier for the user to realize that they are wearing a diaper, not underwear, which may cause psychological stress to the wearer. Furthermore, if the seams (joints) between materials such as nonwoven fabrics in the crotch area are visible, the underwear-like appearance may be marred, making the difference from underwear even more noticeable.

[0058] Therefore, in the crotch portion of the diaper 1, the seams between the materials and the crotch elastic members 40 are made less visible, thereby giving the diaper 1 an appearance similar to underwear when worn. Specifically, in the crotch portion of the diaper 1, the crotch elastic members 40 are made less visible through one or more sheet members laminated on the side away from the skin than the crotch elastic members 40, and the sheet member constituting the outermost layer (the crotch sheet described below) is made continuous in the longitudinal direction. The structure of the crotch portion of the diaper 1 will be described in detail below.

[0059] 5 is a diagram schematically illustrating a cross section of the diaper 1 in a pants-type state when viewed from one side in the left-right direction. As described above, the diaper 1 has a structure in which the waistline member 20 is laminated on the non-skin side of the absorbent main body 10. The absorbent main body 10 and the waistline member 20 are folded in half at the center position CL in the longitudinal direction, and the front waistline portion 20f and the rear waistline portion 20b, which are folded in the thickness direction (the front-to-rear direction in FIG. 5), are joined at both left-to-right ends by a pair of side joining portions 5 to form the pants-type state.

[0060] As shown in FIG. 5, in the diaper 1 in the pants-type state, two sheet members, an elastic member cover sheet 17 and an inner layer sheet 23, are laminated on the non-skin side of the crotch elastic member 40. Hereinafter, these sheet member layers will also be referred to as the "crotch layer CA." That is, the "crotch layer CA" is a layer that contacts the non-skin side of the crotch elastic member 40 in the thickness direction and constitutes at least a portion of the non-skin side of the diaper 1. In addition, in the front waistband portion 20f, a ventral outer layer sheet 21 is provided on the non-skin side of the waist elastic member 24. While FIG. 5 shows only one sheet member (ventral outer layer sheet 21) provided on the non-skin side of the waist elastic member 24, two or more sheet members may be laminated. Similarly, in the rear waistband portion 20b, a back outer layer sheet 23 is provided on the non-skin side of the waist elastic member 25. Hereinafter, these sheet member layers will also be referred to as the "waistband layer WA." That is, the "waist layer WA" is a layer that contacts the waist elastic members 24 (25) from the non-skin side in the thickness direction and also constitutes at least a part of the non-skin side of the diaper 1.

[0061] The diaper 1 is constructed such that the light transmittance of the crotch layer CA is smaller than that of the waist layer WA. Here, "light transmittance" refers to the rate at which light passes through a material, expressed as the ratio of the amount of light after transmission to the amount of light before transmission, and can be measured using a spectrophotometer or a photoelectric photometer. For example, a predetermined size (30 mm x 30 mm) is cut out from each of the crotch layer CA and waist layer WA of the diaper 1, and the light transmittance of each measurement object is measured using a spectrophotometer (JASCO Corporation V-570). The wavelength range of visible light is 380 nm to 750 nm. The measurement conditions may be as follows: Metering mode: Abs Response:Medium Bandwidth: 2.0nm ·Near infrared: 8.0nm Scanning speed: 1000nm / min ·Starting wavelength: 830nm End wavelength: 350nm Data capture interval: 1.0 nm

[0062] If the light transmittance of the crotch layer CA is lower than that of the waist layer WA, the crotch elastic member 40 will be less visible when viewed through the crotch layer CA than the waist elastic member 24 (25) when viewed through the waist layer WA, compared to the reverse case. In other words, when the diaper 1 is viewed from the outside (non-skin side), the crotch elastic member 40 will be less visible than the waist elastic member 24. This will less likely draw the user's (wearer's) attention to the crotch elastic member 40, making the crotch elastic member 40 less noticeable in the diaper 1.

[0063] Furthermore, in the diaper 1, the sheet member constituting the crotch portion, which is positioned furthest from the skin side, is seamless. For example, in FIG. 5, the sheet member (in the diaper 1, the inner-layer sheet 23) that covers the crotch elastic member 40 from the furthest from the skin side and is positioned furthest from the skin side at the longitudinal center position CL is referred to as the "crotch sheet." In this case, the crotch sheet (inner-layer sheet 23) is continuous between the lower end 5feb (the rear end in the longitudinal direction in FIG. 2) of the side joint 5 in the front waistband 20f and the lower end 5beb (the front end in the longitudinal direction in FIG. 2) of the side joint 5 in the rear waistband 20b. In other words, the crotch sheet (inner-layer sheet 23) has no unnecessary seams between the lower end 5feb of the front side joint 5 and the lower end 5beb of the rear side joint 5 in FIG. 5.

[0064] These configurations make it difficult to see the seams of the materials and the crotch elastic members 40 in the crotch portion of the diaper 1. Therefore, the inclusion of the crotch elastic members 40 improves the fit in the crotch portion and allows for a pants-type diaper that has an underwear-like appearance.

[0065] Furthermore, in the diaper 1, unnecessary seams in the waistband member 20 are not visible, and steps in the materials constituting the waistband member are made as inconspicuous as possible. As shown in FIG. 5, in the front waistband portion 20f, at the lower end 5feb of the side joint 5 (the rear end in the longitudinal direction in FIG. 2), three sheet members are stacked on the non-skin side of the crotch elastic member 40. That is, at the position 5feb, three sheet members are stacked: the elastic member cover sheet 17, the inner-layer sheet 23, and the ventral-side outer-layer sheet 21. On the other hand, at a position overlapping the crotch elastic member 40 in the longitudinal direction, two sheet members are stacked on the non-skin side of the crotch elastic member 40. That is, at the position of the crotch elastic member 40, two sheet members are stacked: the elastic member cover sheet 17 and the inner-layer sheet 23. Therefore, in the longitudinal direction (vertical direction) of the front waist portion 20f, the difference in the number of layers of material between the position 5feb and the position of the crotch elastic member 40 is minimal (1 layer), making the step that occurs in the thickness direction less noticeable compared to when the difference in the number of layers is 2 or more layers.

[0066] Similarly, in the rear waistband 20b, at the position 5beb, the lower end (the front end in the longitudinal direction in FIG. 2) of the side joint 5, three sheet members are layered closer to the skin than the crotch elastic member 40. That is, at the position 5beb, three sheet members are layered: the elastic member cover sheet 17, the inner layer sheet 23, and the back-side outer layer sheet 22. On the other hand, at the position overlapping with the crotch elastic member 40 in the longitudinal direction, two sheet members are layered closer to the skin than the crotch elastic member 40, as in the front side. Therefore, in the longitudinal direction (vertical direction) of the rear waistband 20b, the difference in the number of layered materials between the position 5beb and the position of the crotch elastic member 40 is minimized (one sheet), making the step in the thickness direction less noticeable compared to when the difference in the number of layered materials is two or more.

[0067] In this way, in both the front waistband 20f and the rear waistband 20b of the diaper 1, the step formed by the laminated sheet members is minimized, and the step is less noticeable when viewed from the outside (non-skin side), thereby achieving a more underwear-like appearance.

[0068] Also, in the left - right direction, it is preferable that the width Wa of the crotch elastic region ER is smaller than the distance Wb between one end of the crotch elastic region ER and one end of the absorbent core 11 (see Fig. 4A). When wearing the diaper 1, it has been explained that the absorbent core 11 is deformed into a convex shape on the skin side by the contraction force of the crotch elastic region ER. However, if the distance Wb is smaller than the width Wa of the crotch elastic region ER, the central portion in the left - right direction of the absorbent core 11 (the region where the crotch elastic region ER is provided) is likely to be insufficiently erected on the skin side, and the fit to the discharge port may deteriorate. Also, as the ratio of the area of the crotch elastic region ER in the absorbent core 11 increases, the wrinkles formed in the absorbent core 11 when the crotch elastic region ER contracts are likely to be prominent, and there is a risk of spoiling the appearance like underwear.

[0069] On the other hand, as shown in Fig. 4A, if the width Wa of the crotch elastic region ER is smaller than the distance Wb between one end of the crotch elastic region ER and one end of the absorbent core 11 (Wa < Wb), when the absorbent core 11 is deformed into a convex shape on the skin side, the portion where the crotch elastic region ER is provided is likely to stand high on the skin side and is likely to fit the wearer's discharge port. And since the wrinkles formed in the absorbent core 11 when the crotch elastic region ER contracts are less prominent, a more underwear - like appearance can be achieved.

[0070] Also, it is preferable that the color of the sheet member provided on the outermost non - skin side of the crotch layer CA (the sheet member corresponding to the above - mentioned crotch sheet) and the color of the crotch elastic member 40 are of the same color system. Here, the same color system means that it is sufficient if the user can judge them as the same color when visually recognizing the sheet member and the crotch elastic member 40 to be compared. Specifically, it is a region where the color difference ΔE when measured using a color difference meter CR - 300 manufactured by Konica Minolta Co., Ltd. or an equivalent one is less than 13, or a region where the deviation in the 24 - color color chips classified by the Ostwald color wheel is 1 or less.

[0071] In the diaper 1, if the color difference ΔE between the color of the inner layer sheet 23 (crotch sheet) provided closest to the skin of the crotch layer CA and the color of the crotch elastic member 40 is less than 13, when the two are stacked in the thickness direction, it is difficult to distinguish the difference in color between the crotch elastic member 40 and the inner layer sheet 23 when viewed from the non-skin side, making it difficult for the user to recognize the crotch elastic member 40, which is located closer to the skin than the inner layer sheet 23. Therefore, the crotch elastic member 40 is less noticeable, allowing the diaper 1 to have an appearance similar to underwear.

[0072] Fig. 6 is a diagram illustrating the joining of the absorbent main body 10 and the waistline member 20 (outer layer member 20). Fig. 7 is a schematic cross-sectional view taken along the arrows A1-A1 in Fig. 6. The absorbent main body 10 and the waistline member 20 are joined to each other by a main body joining section 70 formed with an adhesive such as a hot melt adhesive. The main body joining section 70 is formed by applying adhesive to the non-skin side of the absorbent main body 10 or the skin side of the waistline member 20 in the region indicated by the diagonally shaded area sloping downward to the right in Fig. 6. Examples of adhesive application patterns include a so-called Ω pattern and a spiral pattern.

[0073] As shown in Fig. 6, the main body joint 70 is provided over almost the entire area of ​​the absorbent main body 10 (absorbent core 11). Meanwhile, blank areas where no adhesive is provided are formed in the area inside the outline of the main body joint 70 shown by the hatched area in Fig. 6 and on both sides of the crotch elastic region ER in the left-right direction. These areas where no adhesive is provided are referred to as non-adhesive areas 75. In other words, the diaper 1 has areas where the absorbent main body 10 and the waist member 20 are not joined to each other (non-adhesive areas 75). In Fig. 7, of the sheet members (elastic member cover sheet 17 and inner layer sheet 23) provided closer to the skin than the crotch elastic member 40 (crotch elastic region ER), the sheet member closest to the skin (the inner layer sheet 23) has the non-adhesive area 75. In other words, in the diaper 1, the inner layer sheet 23, which constitutes the layer closest to the skin of the waistband member 20, and the absorbent body 10, which is adjacent to that layer on the skin side, are not joined to each other at the non-existent portion 75.

[0074] As shown in FIG. 7 , in the diaper 1, the side sheet 16 and the elastic member cover sheet 17, which are located closest to the skin among the sheet members constituting the absorbent main body 10, are independent sheet members. In other words, the sheet member located closest to the skin of the absorbent main body 10 is discontinuous between the elastic member cover sheet 17 located in the lateral center and the side sheets 16 located on both sides. In this configuration, when the crotch elastic region ER (crotch elastic member 40) contracts, wrinkles may occur in the elastic member cover sheet 17, which is laminated on the non-skin side of the crotch elastic member 40 in the lateral center. On the other hand, because the side sheets 16 located on both lateral sides of the elastic member cover sheet 17 are discontinuous from the elastic member cover sheet 17, even if wrinkles form in the elastic member cover sheet 17, the influence of the wrinkles is unlikely to be transmitted from the elastic member cover sheet 17 to the side sheets 16. This prevents wrinkles from forming over a wide area in the crotch region of the diaper 1. Therefore, wrinkles that occur in the crotch area when the diaper 1 is worn are less noticeable, and the appearance of the diaper 1 can be made to look more like underwear.

[0075] The elastic member cover sheet 17 also has left-right end portions that are free of adhesive. In the left-right direction of FIG. 7, both end portions 17e of the elastic member cover sheet 17 overlap with the adhesive-free portions 75, and these end portions 17e form so-called dry edges, i.e., are not coated with adhesive. With this configuration, even if wrinkles form in the elastic member cover sheet 17 due to contraction of the crotch elastic region ER, the dry edges (end portions 17e) on both left-right sides more easily prevent the influence of the wrinkles from being transmitted outward in the left-right direction. This prevents the range of wrinkles formed in the waistband member 20 of the diaper 1 from spreading laterally, making the wrinkles less noticeable in the crotch region. This allows the diaper 1 to have an appearance similar to underwear when worn.

[0076] Furthermore, in the left-right direction, the width W17 of the elastic member cover sheet 17 is preferably smaller than the maximum width W11m of the absorbent core 11 (see FIG. 4A ). As described above, wrinkles may form in the elastic member cover sheet 17 due to contraction of the crotch elastic region ER (crotch elastic member 40), and the larger the width W17 of the elastic member cover sheet 17, the more likely it is that larger wrinkles will form. Therefore, by making the width W17 of the elastic member cover sheet 17 narrower than at least the maximum width W11m of the absorbent core 11, it is possible to prevent excessively large wrinkles from forming in the elastic member cover sheet 17. This makes wrinkles that occur in the crotch area less noticeable when the diaper 1 is worn, and makes the diaper 1 look more like underwear.

[0077] The absorbent core 11 also has a constricted portion 11c in the longitudinal center that is narrower in the left-right direction than both longitudinal ends (see FIG. 4A). The presence of this constricted portion 11c reduces the interference between the edges of both ends of the absorbent core 11 with the wearer's crotch area (groin area) when the diaper 1 is worn, improving fit. It is preferable that the width W17 of the elastic member cover sheet 17 be smaller than the minimum width W11s of the absorbent core 11 (i.e., the minimum width of the constricted portion 11c) in the left-right direction. By making the width W17 of the elastic member cover sheet 17 narrower than the minimum width W11s of the absorbent core 11, it is possible to more effectively prevent large wrinkles from forming in the elastic member cover sheet 17. This reduces the visibility of wrinkles in the crotch area when the diaper 1 is worn, making the diaper 1 appear more like underwear.

[0078] In addition, in the thickness direction of the diaper 1, the sheet member (back sheet 13) disposed adjacent to the skin side of the crotch elastic member 40 (crotch elastic region ER) and the sheet member (inner sheet 23) disposed furthest from the skin side in the thickness direction at the longitudinal center position CL have portions that are not joined to each other. In Figure 7, the inner sheet 23 and the back sheet 13 are not joined to each other at least in the non-adhesive portion 75 where no adhesive is provided.

[0079] In the diaper 1, the backsheet 13 and the elastic member cover sheet 17 are bonded to each other via an adhesive applied to the surface of the crotch elastic member 40. Therefore, when the crotch elastic region ER contracts in the longitudinal direction, wrinkles are likely to form not only on the non-skin-side elastic member cover sheet 17 but also on the skin-side backsheet 13. Meanwhile, the backsheet 13 and the inner-layer sheet 23 provided on the non-skin-side have portions (non-existing portions 75) where they are not bonded to each other in the thickness direction, which prevents wrinkles formed in the backsheet 13 from being transmitted to the non-skin-side inner-layer sheet 23. This reduces the likelihood of wrinkles forming in the waistband member 20 (inner-layer sheet 23) at least at the longitudinal center position CL. Furthermore, the backsheet 13 and the inner-layer sheet 23, which are arranged to sandwich the crotch elastic member 40 in the thickness direction, are less likely to come into close contact with each other in the non-existing portions 75. Therefore, the crotch elastic members 40 sandwiched between the back sheet 13 and the inner sheet 23 are less noticeable than when they are in close contact with each other in the thickness direction, and the appearance of the diaper 1 when worn can be made to look like underwear.

[0080] Even if wrinkles are formed in the backsheet 13 due to longitudinal contraction of the crotch elastic region ER, the provision of the non-existent portions 75 on both lateral sides of the crotch elastic region ER prevents the effects of the wrinkles from spreading beyond the non-existent portions 75 to the lateral sides. This prevents wrinkles from forming over a wider area in the crotch region, making the appearance of the diaper 1 when worn more likely to resemble underwear.

[0081] Furthermore, the diaper 1 has at least two sheet members on the non-skin side of the crotch elastic members 40 (crotch elastic region ER) in the thickness direction. In FIG. 5, an elastic member cover sheet 17 (referred to as the first sheet member) is provided adjacent to the non-skin side of the crotch elastic members 40, and an inner layer sheet 23 (referred to as the second sheet member) is further provided on the non-skin side of the elastic member cover sheet 17. In this case, it is preferable that the average basis weight of the first sheet member is different from that of the second sheet member. Note that the basis weight (g / m 2 ) is an indicator of weight per unit area.

[0082] Sheet members with different basis weights often have different stiffnesses and thicknesses, and are therefore likely to wrinkle differently. Therefore, by stacking a first sheet member (skin-side) and a second sheet member (non-skin-side) with different basis weights in the thickness direction, it is possible to prevent wrinkles formed in the first sheet member from being directly transmitted to the second sheet member. For example, even if wrinkles are formed in the skin-side elastic member cover sheet 17 (first sheet member) when the crotch elastic members 40 of the diaper 1 contract, the likelihood of the formed wrinkles being directly transmitted to the non-skin-side inner layer sheet 23 (second sheet member) can be reduced. This makes wrinkles less noticeable in the crotch area, making the diaper 1 appear more like underwear.

[0083] In this case, it is preferable that the basis weight of the second sheet member on the non-skin side is greater than the basis weight of the first sheet member on the skin side. Generally, sheet members with a larger basis weight tend to be more rigid than sheet members with a smaller basis weight. Therefore, by placing a sheet member with a larger basis weight on the non-skin side, it becomes easier to prevent large wrinkles from forming on the non-skin side. Furthermore, by placing a sheet member with a larger basis weight on the non-skin side, the crotch elastic member 40 on the skin side becomes less visible when the diaper 1 is viewed from the non-skin side. This makes the appearance of the diaper 1 more likely to resemble underwear.

[0084] Furthermore, it is preferable that the fiber orientation direction of the first sheet member (elastic member cover sheet 17) and the fiber orientation direction of the second sheet member (inner layer sheet 23) intersect with each other. For example, in the diaper 1, the fiber orientation direction of the first sheet member (elastic member cover sheet 17) is along the longitudinal direction, and the fiber orientation direction of the second sheet member (inner layer sheet 23) is along the left-right direction, so that they intersect with each other. In this case, the stretchability of the first sheet member along the longitudinal direction is likely to be different from the stretchability of the second sheet member along the longitudinal direction, and the likelihood of wrinkle formation when the crotch elastic region ER contracts along the longitudinal direction is also likely to be different. Therefore, even if wrinkles are formed in the first sheet member, the likelihood of the formed wrinkles being directly transmitted to the second sheet member can be reduced. Furthermore, in the area where multiple fibers intersect, the light transmittance tends to be lower than when the fibers are arranged parallel to each other, making it difficult to see the crotch elastic members 40 through the first and second sheet members, and thus making the crotch elastic members 40 less noticeable. This allows the appearance of the diaper 1 to be more similar to underwear.

[0085] The fiber orientation is a concept consisting of the fiber orientation angle and orientation strength. For example, the fiber orientation direction can be measured by the following method. First, the sheet member to be measured is cut to a predetermined size and placed so that the longitudinal direction (or left-right direction) can be determined. Using a microscope (e.g., a scanning electron microscope such as the JCM-5100 manufactured by JEOL Ltd.), an enlarged image is taken from a direction perpendicular to the measurement surface of the sample, printed, and the fibers are traced on a transparent PET sheet. The enlarged image is an image enlarged to a magnification that allows measurement of 10 or more fibers, for example, 50 to 300 times. The image is imported into a personal computer and binarized using nexusNewQube (standalone version) image processing software manufactured by Nexus Corporation. The orientation angle and orientation strength are obtained from the binarized image using Fiber Orientation Analysis 8.13 Single, a fiber orientation analysis program. The orientation angle is the angle at which the fibers are most oriented, and the orientation strength is the strength at that orientation angle. The closer the orientation angle is to 90°, the more oriented the fibers are in the longitudinal direction (or left-right direction). Also, the greater the orientation strength, the more uniform the fibers are. An orientation strength of 1.05 or more is considered oriented. Repeat the measurement several times (for example, 3 to 5 times) and calculate the average value.

[0086] Furthermore, the diaper 1 may have a region of the main body joint 70 that overlaps with the crotch elastic member 40 when viewed in the thickness direction, where no adhesive is provided. In FIG. 6, the main body joint 70 is provided in the region overlapping with the crotch elastic member 40. However, as described above, the main body joint 70 is formed by applying an adhesive, such as a hot melt adhesive, in an Ω pattern or a spiral pattern. That is, gaps between linearly applied adhesive may form where no adhesive is provided. In the adhesive-free region, the sheet members (the elastic member cover sheet 17 and the inner layer sheet 23) stacked in the thickness direction are less likely to adhere to each other, resulting in lower light transmittance than when they are in close contact. This makes the crotch elastic member 40 less visible, allowing the diaper 1 to have an appearance more similar to underwear.

[0087] Furthermore, when the diaper 1 is viewed in the thickness direction, there are no intersections between the waist elastic members 24, 25 and the buttocks elastic members 26 (lateral elastic members) and the crotch elastic member 40. The elastic force of the crotch elastic member 40 in the longitudinal direction and the elastic force of the waist elastic members 24, 25 and the buttocks elastic members 26 in the lateral direction are less likely to interfere with each other, making it easier for the elastic force of the crotch elastic member 40 to act in the crotch area. This facilitates convex deformation of the absorbent main body 10 toward the skin, further improving the fit of the diaper 1 when worn. Furthermore, the lack of interference between the elastic force in the longitudinal direction and the elastic force in the lateral direction in the crotch area makes it less likely for irregular wrinkles to form, which helps the diaper 1 to appear more like underwear.

[0088] Furthermore, the absorbent core 11 of the diaper 1 preferably does not have a region (low-basis weight region) in the left-right center where the basis weight is lower than other regions. For example, in conventional absorbent articles, low-basis weight regions such as slits are sometimes provided to partially weaken the rigidity of the absorbent core so that the absorbent core can easily undergo three-dimensional deformation in response to the unevenness of the wearer's body. However, in an absorbent main body 10 (absorbent core 11) equipped with crotch elastic members 40 as in the diaper 1, if a low-basis weight region overlapping the crotch elastic members 40 is formed in the left-right center, the rigidity of the absorbent core 11 may become uneven, making it difficult for the absorbent core 11 to undergo a smooth convex deformation when the crotch elastic members 40 contract. In contrast, in the diaper 1 of this embodiment, the absorbent core 11 does not have a low-basis weight region, so the stretching force of the crotch elastic members 40 is easily applied uniformly, and the absorbent core 11 is easily able to undergo a smooth convex deformation. This further improves the fit of the diaper 1 when worn.

[0089] Furthermore, any of the sheet members constituting the crotch layer CA may have letters or images in an area overlapping the crotch elastic member 40 when viewed in the thickness direction. Here, the images include designs and patterns. Fig. 8A shows an example of a diaper 1 having letters on the crotch layer CA. Fig. 8B shows an example of a diaper 1 having images on the crotch layer CA. In Fig. 8A, letters 91 are printed on the crotch sheet (inner layer sheet 23) in a position overlapping the crotch elastic member 40. Similarly, in Fig. 8B, a pattern 92 and a design 93 are printed on the crotch sheet (inner layer sheet 23) in a position overlapping the crotch elastic member 40. A user viewing such a diaper 1 is more likely to pay attention to the letters 91, designs 92, patterns 93, etc. in the crotch area than to the crotch elastic members 40. Furthermore, the crotch elastic members 40 are hidden inside (closer to the skin) the letters 91, designs 92, patterns 93, etc., making them less noticeable. This makes the crotch elastic members 40 less noticeable, making the diaper 1 appear more like underwear. The types and ranges (sizes) of letters and images provided in the crotch area are not limited to those shown in FIGS. 8A and 8B . Letters and images may also be combined. Letters and images may also be provided on a layer (e.g., the elastic member cover sheet 17) closer to the skin than the crotch sheet (inner-layer sheet 23).

[0090] (Modification of Diaper 1) The diaper 1 may be modified as follows. Fig. 9 shows a plan view and a cross-sectional view of a modified diaper 1 in an unfolded and stretched state. In the modified diaper 1, the arrangement of the crotch elastic members 40 (41-45) constituting the crotch elastic region ER differs from that of the above-described embodiment. Specifically, in the modified diaper 1, the crotch elastic members 40 (41-45) are located closer to the skin than the absorbent core 11 (core wrap sheet 18, not shown in Fig. 9) and closer to the skin than the backsheet 13 in the thickness direction. Furthermore, the modified diaper 1 does not include an elastic member cover sheet 17. The rest of the configuration is the same as that of the diaper 1 described above.

[0091] In the diaper 1 of this modified example, the crotch layer CA is composed of the back sheet 13 and the inner layer sheet 23, which are located closer to the skin than the crotch elastic members 40. The crotch sheet (inner layer sheet 23) located closest to the skin of the crotch layer CA is continuous in the longitudinal direction from the lower end 5feb of the front side joint 5 to the lower end 5beb of the rear side joint 5, and does not have any unnecessary seams. The light transmittance of the crotch layer CA is smaller than that of the waist layer WA. Therefore, even when the diaper 1 is modified as shown in the modified example of Fig. 9, the seams of the materials and the crotch elastic members 40 are hardly visible in the crotch area, thereby improving the fit in the crotch area and achieving an underwear-like appearance.

[0092] === Second Embodiment === In the second embodiment, a pants-type diaper 2 (hereinafter also referred to as "diaper 2") having a part of its configuration different from that of the first embodiment will be described. Fig. 10 is a three-view diagram illustrating the configuration of the diaper 2 of the second embodiment.

[0093] The diaper 2 of the second embodiment has a liquid-absorbent main absorbent body 10 and a waistband member 20 arranged on the non-skin side of the absorbent main absorbent body 10. However, the configuration of the waistband member 20 of the diaper 2 is different from that of the diaper 1 of the first embodiment. Specifically, the waistband member 20 of the diaper 2 has an outer layer sheet 27 arranged on the non-skin side of the inner layer sheet 23. The outer layer sheet 27 is a continuous sheet extending from one end (front side) to the other end (rear side) in the longitudinal direction, and corresponds to a sheet member formed by integrating the ventral side outer layer sheet 21 and the dorsal side outer layer sheet 22 of the diaper 1. The configuration other than the outer layer sheet 27 is basically the same as that of the diaper 1.

[0094] In the diaper 2, the crotch layer CA is composed of three sheet layers: an elastic member cover sheet 17, which is located closer to the skin than the crotch elastic members 40, an inner layer sheet 23, and an outer layer sheet 27. The crotch sheet (outer layer sheet 27), which is located closest to the skin of the crotch layer CA, is continuous in the longitudinal direction from the lower end 5feb of the front side joint 5 to the lower end 5beb of the rear side joint 5, and does not have any unnecessary seams. The light transmittance of the crotch layer CA is smaller than that of the waist layer WA. Therefore, the seams of the materials and the crotch elastic members 40 are less visible in the crotch portion of the diaper 2, thereby improving the fit in the crotch portion and achieving an underwear-like appearance.

[0095] ===Third Embodiment=== In the third embodiment, a pants-type diaper 3 (hereinafter also referred to as "diaper 3") having a part of its configuration different from those of the first and second embodiments will be described. Fig. 11 is a three-view diagram illustrating the configuration of the diaper 3 of the third embodiment.

[0096] 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, the waistline member 20 is divided into a front side (ventral side) and a rear side (back side), and is composed of two members, a front waistline section 20f and a rear waistline section 20b. In other words, the diaper 3 is a pants-type absorbent article with a so-called three-piece structure, in which the front waistline section 20f and the rear waistline section 20b are arranged with a gap in the longitudinal direction, and the absorber 10 is arranged to span between the front waistline section 20f and the rear waistline section 20b.

[0097] As shown in the A3-A3 cross-sectional view of Fig. 11, in the absorbent main body 10 of the diaper 3, a plurality of crotch elastic members 40 are provided in a longitudinally stretched state on the non-skin side of the absorbent core 11 in the thickness direction and on the skin side of the backsheet 13, and crotch elastic regions ER are defined by the plurality of crotch elastic members 40. In addition, the side sheet 16 is continuous from one side to the other in the left-right direction (see the A3-A3 cross-sectional view of Fig. 11), and the leakage barrier walls 60 on both the left and right sides are formed by a single side sheet 16. The rest of the configuration is substantially the same as that of the absorbent main body 10 of the diaper 1.

[0098] The front waist portion 20f of the diaper 3 comprises a ventral outer sheet 21, a ventral inner sheet 23f disposed on the skin side of the ventral outer sheet 21 and having substantially the same shape as the ventral outer sheet 21, and a plurality of waist elastic members 24 disposed between the ventral outer sheet 21 and the ventral inner sheet 23f. Similarly, the rear waist portion 20b of the diaper 3 comprises a dorsal outer sheet 22, a dorsal inner sheet 23b disposed on the skin side of the dorsal outer sheet 22 and having substantially the same shape as the dorsal outer sheet 22, and a plurality of waist elastic members 25 and buttocks elastic members 26 disposed between the dorsal outer sheet 22 and the dorsal inner sheet 23b.

[0099] In the diaper 3, the crotch layer CA is composed of two sheet layers: a back sheet 13, which is located closer to the skin than the crotch elastic member 40, and a side sheet 16. The crotch sheet (side sheet 16), which is located closest to the skin of the crotch layer CA, is continuous in the longitudinal direction from the lower end 5feb of the side joint 5 in the front waistline 20f to the lower end 5beb of the side joint 5 in the rear waistline 20b, and does not have any unnecessary seams. The light transmittance of the crotch layer CA is smaller than that of the waistline layer WA. Therefore, the seams of the materials and the crotch elastic member 40 are less visible in the crotch portion of the diaper 3, thereby improving the fit in the crotch portion and achieving an underwear-like appearance.

[0100] ===Other=== The above-described embodiments are intended to facilitate understanding of the present invention and are not intended to limit the present invention. 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]

[0101] 1 Diaper (first embodiment, pants-type disposable diaper, pants-type absorbent article), 2 Diaper (second embodiment), 3 Diaper (third embodiment), 5 side joints, 5feb lower end (longitudinal rear end), 5beb lower end (longitudinal front end), 10. Absorbent body; 11 absorbent core, 11c waist portion, 12 top sheet, 13 back sheet, 15 middle sheet, 16 side sheet, 17 elastic member cover sheet, 18 core wrap sheet, 19 Leg gather elastic member, 20 waistband member (exterior member), 20f front waistband, 20b rear waistband, 21 ventral outer sheet, 22 dorsal outer sheet, 23 inner layer sheet, 23f ventral inner layer sheet, 23b dorsal inner layer sheet, 24 waist elastic member (ventral side), 25 waist elastic member (dorsal side), 26 buttocks elastic member, 27 outer layer sheet, 31 cover sheet, 32 cover sheet, 40 crotch elastic member, 41 to 45 crotch elastic member, 60 Leakage prevention wall section, 61 Leak-proof wall elastic member, 70 Main body joint, 75 non-existent part, 91 Letters, 92 Designs, 93 Patterns, BH waist opening, LH leg opening, CL central position (longitudinal direction), ER crotch elastic area, CA inseam layer, WA Waist layer

Claims

1. In the deployed and extended state, the device has a longitudinal direction, a left-right direction, and a thickness direction which intersect with each other, an absorbent body having an absorbent core; a waistband member having a front waistband portion and a rear waistband portion, a pants-type absorbent article in which the front waistband portion and the rear waistband portion are joined to each other at both ends in the left-right direction by a pair of side joining portions, a crotch elastic member that is provided closer to the skin than the absorbent core and stretches along the longitudinal direction; The waistband member has a waistband elastic member that stretches in the left-right direction, a crotch sheet that covers the crotch elastic members from the non-skin side and is located closest to the skin side at a central position in the longitudinal direction, the crotch sheet is continuous in the longitudinal direction between a rear end of the side joint portion provided in the front waistband portion and a front end of the side joint portion provided in the rear waistband portion, the pants-type absorbent article has a crotch layer that contacts the crotch elastic members from the non-skin side in the thickness direction and constitutes at least a part of the non-skin side of the pants-type absorbent article, and a waist layer that contacts the waist elastic members from the non-skin side in the thickness direction and constitutes at least a part of the non-skin side of the pants-type absorbent article, A pants-type absorbent article, characterized in that the light transmittance of the crotch layer is smaller than the light transmittance of the waist layer.

2. The pants-type absorbent article according to claim 1, the number of sheet members laminated on the non-skin side of the crotch elastic members at the rear end of the side joint portion in the front waistline portion or the front end of the side joint portion in the rear waistline portion in the longitudinal direction; A pants-type absorbent article characterized in that the difference between the number of sheet members stacked on the non-skin side of the crotch elastic members at a position overlapping the crotch elastic members in the longitudinal direction and the number of sheet members stacked on the non-skin side of the crotch elastic members is within one.

3. The pants-type absorbent article according to claim 1 or 2, a crotch elastic region defined by the crotch elastic member; A pants-type absorbent article characterized in that, in the left-right direction, the width of the crotch elastic region is smaller than the distance between the most one end of the crotch elastic region and the most one end of the absorbent core.

4. The pants-type absorbent article according to claim 1 or 2, A pants-type absorbent article, characterized in that the color of the crotch elastic members and the color of the crotch sheet are similar to each other.

5. The pants-type absorbent article according to claim 1 or 2, a main body joining portion that joins the absorbent main body and the waistband member; A pants-type absorbent article characterized in that, when viewed in the thickness direction, the main body joint has a portion where no adhesive is provided in the area overlapping with the crotch elastic member.

6. The pants-type absorbent article according to claim 1 or 2, A pants-type absorbent article, characterized in that the sheet member disposed closest to the skin of the absorbent main body is discontinuous between the center portion and both side portions in the left-right direction.

7. The pants-type absorbent article according to claim 6, A pants-type absorbent article characterized in that, among the sheet members arranged closest to the skin of the absorbent main body, the width of the sheet member that overlaps with the crotch elastic member in the central portion in the left-right direction is smaller than the maximum width of the absorbent core.

8. The pants-type absorbent article according to claim 7, A pants-type absorbent article characterized in that, among the sheet members arranged closest to the skin of the absorbent main body, the width of the sheet member that overlaps with the crotch elastic member in the central portion in the left-right direction is smaller than the minimum width of the absorbent core.

9. The pants-type absorbent article according to claim 6, A pants-type absorbent article characterized in that, among the sheet members arranged closest to the skin of the absorbent main body, the sheet member that overlaps with the crotch elastic member in the central portion in the left-right direction has portions at both ends in the left-right direction where no adhesive is provided.

10. The pants-type absorbent article according to claim 1 or 2, A pants-type absorbent article, characterized in that the waist elastic members and the crotch elastic members do not intersect when viewed in the thickness direction.

11. The pants-type absorbent article according to claim 1 or 2, A pants-type absorbent article, characterized in that the absorbent core does not have a low basis weight region in the central part in the left-right direction, the region having a basis weight lower than that of other regions.

12. The pants-type absorbent article according to claim 1 or 2, A pants-type absorbent article characterized in that, in the thickness direction, there is a portion where the sheet member arranged adjacent to the skin side of the crotch elastic member and the sheet member arranged furthest from the skin side are not joined.

13. The pants-type absorbent article according to claim 1 or 2, A pants-type absorbent article characterized in that the average basis weight of a first sheet member provided on the non-skin side of the crotch elastic member in the thickness direction is different from the average basis weight of a second sheet member provided on the non-skin side of the first sheet member.

14. The pants-type absorbent article according to claim 13, A pants-type absorbent article, wherein the fiber orientation direction of the first sheet member and the fiber orientation direction of the second sheet member intersect with each other.

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