Disposable absorbent article

Abstract

To reduce variation in strength of welding joint.SOLUTION: In a disposable absorbent article 1, a center sheet 31 and a pair of gather sheets 32 are joined by welding with pressure in a compression joining region 4. The compression bonding region 4 includes an end bonding region 42 located in a range of both ends in the longitudinal direction. The edge on the center side in the longitudinal direction of the end joined region 42 is a discontinuous line, and the edge is inclined to the center side in the longitudinal direction toward the outside in the width direction. An additional joining region 401 is present on the outer side or the inner side in the width direction of the range in which the edge is disconnected.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] FIELD OF THE INVENTION The present invention relates to disposable absorbent articles for receiving exudates from a wearer. [Background technology]

[0002] A conventional technique for joining nonwoven fabrics together is to use welding, which involves applying pressure while using heat or ultrasonic vibrations. The area joined using this method is also called an "embossment." Patent Document 1 discloses a sanitary napkin in which side sheets are arranged to cover both sides of the topsheet, and the topsheet and sidesheet are joined at an embossed area extending in the front-to-rear direction. The embossed area is wider at the front and back of the sanitary napkin and narrower in the center.

[0003] Patent Document 2 discloses a structure in which the joint between the topsheet and the leak-proof part is located at the center of the sanitary napkin, outside the front and rear parts in the width direction.

[0004] However, the embossed areas are relatively hard. Therefore, when the embossed areas are widely separated on both the front and back sides of the absorbent article, as in Patent Document 1, discomfort occurs on both the left and right sides of the front and back regions of the absorbent article. In particular, when a gathered sheet for preventing leakage is widely distributed on both the ventral and dorsal sides when worn, such as in disposable diapers or disposable auxiliary absorbents placed inside diapers or diaper-like covers, attempting to fix the gathered sheet to the center sheet using embossing (i.e., by welding) is likely to cause discomfort. Patent Document 1 also does not take into consideration the discomfort that may occur on the left and right sides of the front and back regions of the absorbent article when a gathered sheet having an elastic member is provided. Note that the sanitary napkin in Patent Document 1 has embossed areas that are linearly arranged in the vertical direction, and the gathers are not structured to stand up significantly. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Application Laid-Open No. 2008-289622 [Patent Document 2] Japanese Patent Application Laid-Open No. 2003-24384 Summary of the Invention [Problem to be solved by the invention]

[0006] The present invention aims to reduce the variation in the range of the protrusions of the embossing roll on which ultrasonic vibrations act as the embossing roll rotates, thereby reducing the variation in the strength of the welded joint. [Means for solving the problem]

[0007] The invention described in claim 1 is a disposable absorbent article for receiving excrement from a wearer, comprising a top sheet, a back sheet, and an absorbent core located between the top sheet and the back sheet, wherein the top sheet comprises a center sheet and a pair of gathered sheets fixed to the center sheet at a distance from a center line facing the longitudinal direction on both sides in a width direction perpendicular to the longitudinal direction, and each of the pair of gathered sheets comprises a side sheet elongated in the longitudinal direction and an elastic member fixed to an inner region of the side sheet in the width direction and stretching in the longitudinal direction, and the center sheet and the pair of gathered sheets are joined by compression. The center sheet and each gathered sheet are joined by pressure welding in the joining region, and the compressed joining region between the center sheet and each gathered sheet includes an end joining region located in the range of both ends in the vertical direction, and the end joining region includes an outer joining region located outside the elastic member in the width direction and an inner joining region located inside the elastic member in the width direction, and the edge of the end joining region on the center side in the vertical direction is a discontinuous line, and the edge inclined toward the center in the vertical direction as it moves outward in the width direction, and an additional joining region is present on the outside or inside in the width direction of the range where the edge is discontinued.

[0008] The invention described in claim 2 is the disposable absorbent article described in claim 1, wherein the compressed bonded areas are a collection of a large number of dot-shaped bonded elements.

[0009] The invention described in claim 3 is a disposable absorbent article described in claim 1 (which may also be claim 1 or 2), which comprises a plurality of elastic members including the elastic member, and the elastic member located most inward in the width direction among the plurality of elastic members is located more inward in the width direction than the inner bonding area.

[0010] The invention described in claim 4 is a disposable absorbent article described in claim 3, wherein the elastic member that is second from the inside in the width direction among the plurality of elastic members is located between the inner bonding area and the outer bonding area in the width direction.

[0011] The invention described in claim 5 is a disposable absorbent article described in claim 1 (which may be any one of claims 1 to 4), wherein the outer bonding area includes a plurality of linear areas extending in the vertical direction.

[0012] The invention as set forth in claim 6 is the disposable absorbent article as set forth in claim 5, wherein the plurality of linear regions are connected on the inner side in the longitudinal direction.

[0013] The invention described in claim 7 is a disposable absorbent article according to any one of claims 1 to 6, which is placed in a diaper or a diaper-like cover. [Effects of the Invention]

[0014] According to the present invention, it is possible to reduce variations in strength of the welded joint. [Brief explanation of the drawings]

[0015] [Figure 1] FIG. 2 is a plan view showing the configuration of the absorbent article. [Figure 2] FIG. 2 is a perspective view showing one of the absorbent articles in its free state. [Figure 3]FIG. 2 is a cross-sectional view of the absorbent article. [Figure 4] FIG. 2 is a cross-sectional view of the absorbent article. [Figure 5] FIG. 2 is an enlarged cross-sectional view showing the vicinity of the gathered sheet. [Figure 6] FIG. 10 is an enlarged view showing the vicinity of the boundary between the central joining region and the end joining region. DETAILED DESCRIPTION OF THE INVENTION

[0016] FIG. 1 is a plan view showing the configuration of a disposable absorbent article 1 (hereinafter simply referred to as "absorbent article 1") according to one embodiment of the present invention. FIG. 1 shows the absorbent article 1 unfolded flat. The absorbent article 1 is an auxiliary absorbent device that is placed inside (i.e., on the wearer's side) of an outer article worn by a wearer and receives excrement from the wearer. The outer article may be a disposable diaper, a non-disposable diaper, a diaper-like cover, or the like. The absorbent article 1 is used, for example, by people receiving care in hospitals or nursing homes. In FIG. 1, the side of the absorbent article 1 that comes into contact with the wearer is drawn facing forward. In the following description, the up-down direction in FIG. 1 is referred to as the "longitudinal direction," and the left-right direction perpendicular to the longitudinal direction is referred to as the "width direction." The absorbent article 1 is symmetrical, and the center line facing the longitudinal direction in FIG. 1 is denoted by the reference numeral 11.

[0017] 2 is a perspective view showing one of the free states of the absorbent article 1. As will be described later, the absorbent article 1 includes elastic members, and the entire absorbent article 1 assumes a curved state due to contraction of the elastic members.

[0018] Fig. 3 is a cross-sectional view of the absorbent article 1 taken along a plane perpendicular to the longitudinal direction at position III-III in Fig. 1. However, as shown in Fig. 2, gathers of a gathered sheet (described later) stand up due to the contractile force of the elastic member, and therefore Fig. 3 depicts the gathers in an upright state. Fig. 4 is a cross-sectional view of the absorbent article 1 taken along a plane perpendicular to the longitudinal direction at position IV-IV in Fig. 1.

[0019] As shown in FIGS. 1 to 4, the absorbent article 1 comprises a top sheet 21, an absorbent core 22, and a back sheet 23. The absorbent core 22 is located between the top sheet 21 and the back sheet 23. The top sheet 21 comprises a center sheet 31 and a pair of gathered sheets 32. The pair of gathered sheets 32 are fixed on both side portions of the center sheet 31 (i.e., at positions spaced apart on both sides in the width direction) and extend in the longitudinal direction. Each gathered sheet 32 ​​extends over the entire length of the center sheet 31 in the longitudinal direction. In other words, the longitudinal length of each gathered sheet 32 ​​is substantially the same as the longitudinal length of the absorbent article 1. The gathers, which are the inner portions of the pair of gathered sheets 32 in the width direction, stand up toward the wearer when the absorbent article 1 is worn.

[0020] The upper and lower regions of the absorbent article 1 in FIG. 1 are the front and rear regions that come into contact with the wearer's abdominal and dorsal skin, respectively. The region of the absorbent article 1 that continues from the front and rear regions and faces the wearer's crotch is the central region that faces the wearer's crotch. The boundaries between the front and central regions and the boundaries between the rear and central regions do not need to be clearly defined. In the absorbent article 1, the front, central, and rear regions are aligned in this order in the vertical direction. In the example shown in FIG. 1, the absorbent article 1 is substantially rectangular in plan view, and the widths of the front, central, and rear regions (i.e., the width in the left-right direction when worn, hereinafter also simply referred to as "width") are substantially the same. In other words, the width of the absorbent article 1 is substantially constant over the entire vertical length. The above-mentioned FIGS. 3 and 4 are cross-sectional views of the absorbent article 1 at the central and front regions, respectively. The cross-section of the rear region of the absorbent article 1 is substantially similar to the cross-section of the front region shown in FIG. 4. The width of the absorbent article 1 does not need to be constant; for example, the width of the rear portion may be greater than the width of the front portion.

[0021] As shown in Figures 1, 3, and 4, the absorbent core 22 is sandwiched between the top sheet 21 and the back sheet 23. The top sheet 21 and the back sheet 23 are joined together around the periphery of the absorbent core 22 using an adhesive. In Figure 1, the outline of the absorbent core 22 is drawn with a thin dashed line. In Figures 3 and 4, to make the drawings easier to understand, the absorbent article 1 is drawn larger than it actually is in the thickness direction (i.e., the vertical direction in Figures 3 and 4), and components of the absorbent article 1 that are actually in contact or joined together are drawn appropriately spaced apart in the thickness direction.

[0022] The center sheet 31 of the top sheet 21 quickly captures moisture from the wearer's bodily waste and transfers it to the absorbent core 22. The absorbent core 22 absorbs moisture that has permeated the center sheet 31 and quickly fixes it. The back sheet 23 mainly prevents moisture from bodily waste that has permeated the center sheet 31 and the absorbent core 22 and reached the back sheet 23 from seeping out of the absorbent article 1. In the example shown in FIG. 3 , the absorbent core 22 contacts the center sheet 31 and the back sheet 23, but a backing sheet (e.g., tissue paper) may be placed between the absorbent core 22 and the center sheet 31, or a backing sheet may be placed between the absorbent core 22 and the back sheet 23. The absorbent core 22 may be wrapped in another sheet, or the absorbent core 22 may be composed of multiple overlapping absorbent cores. In other words, various known structures may be adopted for the absorbent core 22 and its surrounding structure.

[0023] The length of the topsheet 21 and the backsheet 23 in the longitudinal direction is longer than the length of the absorbent core 22. The width of the topsheet 21 and the backsheet 23 in the width direction is greater than the width of the absorbent core 22. Both side edges of the topsheet 21 (i.e., both sides in the width direction) are joined to both side edges of the backsheet 23 over their entire lengths, either directly or indirectly via an intervening material. The width of the center sheet 31 may be smaller than the width of the backsheet 23, in which case the outer edges of the gathered sheet 32 ​​in the width direction may be joined to the backsheet 23. At the longitudinal edges of the absorbent article 1, the longitudinal edges of the topsheet 21 and the longitudinal edges of the backsheet 23 are joined directly or indirectly. The topsheet 21 and the backsheet 23 are joined around the entire periphery of the absorbent core 22, so that the entire absorbent core 22 is surrounded by the topsheet 21 and the backsheet 23. The topsheet 21 and the backsheet 23 are joined together using, for example, a hot melt adhesive. The topsheet 21 and the backsheet 23 may be joined together by various methods other than a hot melt adhesive.

[0024] For example, a liquid-permeable nonwoven fabric (such as a point-bonded nonwoven fabric, an air-through nonwoven fabric, or a spun-bonded nonwoven fabric) made of hydrophobic fibers (such as polypropylene, polyethylene, polyester, polyamide, or nylon) whose surfaces have been hydrophilically treated with a surfactant is used as the center sheet 31. Alternatively, a nonwoven fabric (such as a spunlace nonwoven fabric) made of hydrophilic fibers such as cellulose, rayon, or cotton may be used as the center sheet 31.

[0025] The backsheet 23 preferably has a laminated structure in which multiple sheets are laminated. For example, the backsheet 23 has a structure in which a nonwoven fabric is laminated on a liquid-repellent or liquid-impermeable nonwoven fabric or a plastic film. When the backsheet 23 includes a plastic film, the plastic film is disposed opposite the absorbent core 22. The plastic film is preferably moisture-permeable (breathable). This improves the water resistance of the backsheet 23 and prevents the absorbent article 1 from becoming stuffy, improving comfort for the wearer. For example, a liquid-repellent or liquid-impermeable nonwoven fabric is used as the nonwoven fabric laminated on the plastic film. This improves the feel of the backsheet 23, such as the touch and texture. The nonwoven fabric is, for example, a spunbonded nonwoven fabric, a meltblown nonwoven fabric, or an SMS (spunbond-meltblown-spunbond) nonwoven fabric made of hydrophobic fibers, and is treated with a liquid repellent coating as needed.

[0026] The absorbent core 22 is a generally sheet-like member whose thickness is smaller than its length and width. The absorbent core 22 is provided across the front, central, and rear portions of the absorbent article 1. That is, the absorbent core 22 is located on the wearer's abdominal side, crotch area, and back side. The shape of the absorbent core 22 in a plan view may be modified in various ways. For example, the width of the rear portion of the absorbent core 22 may be greater than the width of the front portion. Alternatively, the width of the central portion of the absorbent core 22 may be smaller than the widths of the front and rear portions.

[0027] The absorbent core 22 is, for example, a sheet-like fiber assembly in which a superabsorbent material is dispersed. The fiber assembly is, for example, an assembly of pulp fibers and / or synthetic fibers. The superabsorbent material is, for example, granular SAP (Super Absorbent Polymer) or fibrous SAF (Super Absorbent Fiber). The absorbent core 22 may be a sheet-like fiber assembly that does not contain a superabsorbent material. Alternatively, the absorbent core 22 may be substantially free of fibers such as pulp fibers, and may be formed by fixing a superabsorbent material between two liquid-permeable sheet members (for example, nonwoven fabrics) with a hot-melt adhesive or the like.

[0028] As shown in Figs. 1 and 3, each gathered sheet 32 ​​includes a side sheet 321 and elastic members 3221 to 3223. In Figs. 1 and 3, only the right gathered sheet 32 ​​is denoted by the reference numerals 321, 3221 to 3223. The side sheet 321 is a substantially strip-shaped sheet member that is long in the vertical direction. In the present embodiment, each of the left and right gathered sheets 32 is provided with three elastic members 3221 to 3223. Each of the elastic members 3221 to 3223 is linear and extends in the vertical direction, and is fixed to an inner region of the side sheet 321 in the width direction. When the absorbent article 1 is in the state shown in Fig. 1 where it is spread out flat, the elastic members 3221 to 3223 are stretched, and as the elastic members 3221 to 3223 contract, the gathered sheet 32 ​​contracts and the absorbent article 1 curves into a substantially cup shape, as shown in Fig. 2. As a result, the inner portion of the gathered sheet 32 ​​in the width direction stands up from the center sheet 31 as shown in FIG.

[0029] FIG. 5 is an enlarged view of the vicinity of the gathered sheet 32 ​​on the right side of FIG. 3. The gathered sheet 32 ​​on the left side has the same structure. As shown in FIG. 5, the side sheet 321 has a structure in which an inner sheet 331 and an outer sheet 332 overlap by folding back a single sheet. The folded-back position is the inner edge 333 of the gathered sheet 32 ​​in the width direction. Three elastic members 3221 to 3223 are disposed between the inner sheet 331 and the outer sheet 332. Hereinafter, the three elastic members 3221 to 3223 will be referred to as the "first elastic member 3221," the "second elastic member 3222," and the "third elastic member 3223," respectively, from the inner side to the outer side in the width direction. The first elastic member 3221 is disposed near the edge 333 of the gathered sheet 32 ​​and along the edge. The second and third elastic members 3222 and 3223 are disposed spaced apart from the first elastic member 3221 on the outer side in the width direction.

[0030] A water-repellent or liquid-impermeable nonwoven fabric (such as a spunbond nonwoven fabric, meltblown nonwoven fabric, or SMS nonwoven fabric) made of hydrophobic fibers is used as the side sheet 321, and is subjected to a liquid-repellent treatment as necessary. For example, polyurethane thread, a strip-shaped polyurethane film, or thread-shaped or strip-shaped natural rubber is used as the elastic members 3221 to 3223.

[0031] The side sheets 321 are fixed onto the center sheet 31. In Figures 1, 3, and 4, the joint area between the center sheet 31 and the side sheets 321, i.e., the joint area between the center sheet 31 and the gathered sheet 32, is indicated by hatching. In this embodiment, the center sheet 31 and the pair of gathered sheets 32 are joined by welding with pressure. Hereinafter, this joint area will be referred to as the "compression welding area 4." "Welding with pressure" refers to thermal welding, which involves applying pressure while applying heat, or ultrasonic welding, which involves applying pressure while applying ultrasonic vibrations, a process known as "embossing." Because compression is achieved by pressure, "welding with pressure" can also be considered "welding with compression." Note that the center sheet 31 and the gathered sheet 32 ​​may be joined by other joining methods, such as a method using a hot-melt adhesive.

[0032] The compression-bonding region 4 includes a central bonding region 41 located in the center in the longitudinal direction and end bonding regions 42 located in both end ranges in the longitudinal direction. As shown in FIG. 1, one absorbent article 1 has two central bonding regions 41 and four end bonding regions 42. Each central bonding region 41 is spaced outward in the width direction from the three elastic members 3221-3223. Each end bonding region 42 does not overlap with the three elastic members 3221-3223. As shown in FIG. 1, each central bonding region 41 is elongated in the longitudinal direction. Each end bonding region 42 includes three linear regions extending in the longitudinal direction. Hereinafter, the three linear regions will be referred to as the "first linear region 421," the "second linear region 422," and the "third linear region 423," respectively, from the inside to the outside in the width direction. In FIG. 1, only the upper right portions are labeled with the reference numerals 421-423. Furthermore, since the second linear region 422 and the third linear region 423 are located outside the second and third elastic members 3222, 3223 in the width direction, they are collectively referred to as the "outer bonding region 432", and the first linear region 421, which is located inside the second and third elastic members 3222, 3223 in the width direction, is also referred to as the "inner bonding region 431".

[0033] The inner bonding region 431 and the outer bonding region 432 are spaced apart in the width direction. The second and third elastic members 3222, 3223 are located between the inner bonding region 431 and the outer bonding region 432 in the width direction. The innermost first elastic member 3221 is located more inward in the width direction than the inner bonding region 431. In other words, the positions in the width direction where the three elastic members 3221 to 3223 are arranged do not overlap with the widthwise extent of either the inner bonding region 431 or the outer bonding region 432.

[0034] When the absorbent article 1 is manufactured, multiple absorbent cores 22 are sandwiched between a continuous top sheet 21 and a continuous back sheet 23 corresponding to multiple absorbent articles 1, and then individual absorbent articles 1 are cut from this continuous laminate. However, because the three elastic members 3221-3223 do not overlap with the end joining region 42, after cutting, the ends of the three elastic members 3221-3223 are freely contracted within the gathered sheet 32. Therefore, after cutting, the end joining region 42 is not subjected to force from any of the elastic members 3221-3223. As a result, the end joining region 42, which has become hardened by compression joining, is prevented from being strongly curved inward, i.e., toward the wearer, due to the force from the elastic members 3221-3223, thereby improving the wearing comfort of the absorbent article 1. Note that although the longitudinal extent of the end joining region 42 and the longitudinal extent of the elastic members 3221-3223 overlap in FIG. 1 , these extents do not have to overlap.

[0035] The second linear region 422 and the third linear region 423 are connected on the inside in the vertical direction. By dividing the outer joining region 432 into the second linear region 422 and the third linear region 423, the flexibility of the absorbent article 1 can be increased in the outer regions in the width direction of the front and rear portions of the absorbent article 1. As a result, the outer regions in the width direction of the front and rear portions can more easily conform to the inner surface of the diaper (including a diaper-like cover; the same applies hereinafter) and the wearer's body, improving wearing comfort. In addition, the breathability of the end joining region 42 is improved.

[0036] 6 is an enlarged view of the boundary between the central bonding area 41 and the end bonding area 42 in the upper right corner of FIG. 1. Each of the numerous dots 40 in FIG. 6 is a piece of the compressed bonding area, i.e., a single dot-shaped embossment and a single recessed area. Hereinafter, the dots 40 will be referred to as "bonding elements 40." The compressed bonding area 4 is formed by numerous bonding elements 40, but the spacing between the bonding elements 40 is small, so the compressed bonding area 4 will be considered to include the areas between the bonding elements 40.

[0037] As shown by the leader lines at the top of Figure 6, the outer widthwise edges of the end joining regions 42 (at widthwise position 443) are located widthwise more inward than the inner widthwise edge of the central joining region 41 (at widthwise position 442). By positioning the end joining regions 42 widthwise more inward than the central joining region 41, there are no hardened portions in the outer widthwise regions of the front and rear regions of the absorbent article 1 due to compression joining, improving flexibility. As a result, the outer widthwise regions of the front and rear regions can more easily conform to the inner surface of the diaper and the wearer's body, improving wearing comfort. By positioning the central joining region 41 widthwise more outward than the end joining regions 42, it is possible to make the gathers stand up significantly, effectively preventing side leakage of body exudates. Also, preferably, the widthwise size of the end joining region 42, i.e., the distance between the position 443 of the outer edge of the end joining region 42 and the position 444 of the inner edge of the end joining region 42, is greater than the widthwise size of the central joining region 41, i.e., the distance between the position 441 of the outer edge of the central joining region 41 and the position 442 of the inner edge.

[0038] Here, the central bonding region 41 and the outer bonding regions 432 are continuous in the longitudinal direction. This prevents bodily waste received by the absorbent article 1 from leaking between the central bonding region 41 and the outer bonding regions 432. As described above, the spacing between the bonding elements 40 is narrow enough to prevent bodily waste from leaking. More preferably, the compressed bonding regions 4 extend over the entire longitudinal length of the topsheet 21. This allows the ultrasonic vibrations to continuously act on the protrusions of the roll (the so-called embossing roll) that forms the compressed bonding regions 4, when the compressed bonding regions 4 are formed using ultrasonic vibrations. As a result, the ultrasonic vibrations act stably on the protrusions of the embossing roll, reducing fluctuations in the strength of the welded bond. Furthermore, wear on the protrusions of the embossing roll is suppressed, thereby extending the life of the embossing roll. Even when the compressed bonding regions 4 are formed by thermal welding, fluctuations in the linear pressure generated between the pair of rolls sandwiching the sheet on which the compressed bonding regions 4 are formed are suppressed, reducing fluctuations in the strength of the welded bond. Furthermore, wear of the protrusions of the embossing roll is suppressed, thereby improving the life of the embossing roll.

[0039] More preferably, the maximum value of the total length of the compression-bonded portions in the width direction of the compression-bonded region 4 is 1.25 to 4 times the minimum value. Here, the "total length of compression-bonded portions" refers to the total length of the area actually compressed and bonded by the bonding elements 40, etc., on a line extending in the width direction (or the length of that area, if there is only one area). The total length of compression-bonded portions is more preferably 1.5 to 3 times the minimum value. This allows the ultrasonic vibrations to act stably on the protrusions of the embossing roll, reducing fluctuations in the strength of the welded bond. Furthermore, wear on the protrusions of the embossing roll is suppressed, thereby extending the life of the embossing roll. Even when the compression-bonded region 4 is formed by thermal welding, fluctuations in the linear pressure generated between a pair of rolls sandwiching the sheet on which the compression-bonded region 4 is formed are suppressed, reducing fluctuations in the strength of the welded bond. Furthermore, wear on the protrusions of the embossing roll is suppressed, thereby extending the life of the embossing roll.

[0040] The edge of the end joint region 42 on the longitudinal center side (in FIG. 6, the edge portion of the end joint region 42 is indicated by a solid line and the remaining portion by a dashed line) is a discontinuous line that terminates at the positions of the second and third elastic members 3222 and 3223, and the edge slopes toward the longitudinal center as it extends outward in the width direction. The edge is not limited to a straight line and may be curved. An additional joint region 401 exists outside the width direction of the region where the edge terminates (in FIG. 6, indicated by a reference numeral 446). This reduces fluctuations in the range of the embossing roll protrusions on which ultrasonic vibrations act during rotation of the embossing roll, thereby reducing fluctuations in the strength of the welded joint. Furthermore, wear on the protrusions of the embossing roll is suppressed, thereby extending the life of the embossing roll. Even when the compression joint region 4 is formed by thermal welding, fluctuations in the linear pressure generated between the pair of rolls are suppressed, thereby reducing fluctuations in the strength of the welded joint. Furthermore, wear of the protrusions of the embossing roll is suppressed, thereby improving the life of the embossing roll. The "added bonding area" can be understood as a distortion of the edge that should be linear from the surrounding shape in the end bonding area 42, or an isolated bonding area. The added bonding area 401 may be provided inside the range 446 where the edge is discontinued in the width direction.

[0041] Here, for convenience, the edge of the central bonding region 41 corresponding to the outer position 441 of the widthwise outermost bonding element 40 of the central bonding region 41 will be called the "outer edge 441," the edge of the central bonding region 41 corresponding to the inner position 442 of the widthwise innermost bonding element 40 will be called the "inner edge 442," the edge of the end bonding region 42 corresponding to the outer position 443 of the widthwise outermost bonding element 40 of the end bonding region 42 will be called the "outer edge 443," and the edge of the end bonding region 42 corresponding to the inner position 444 of the widthwise innermost bonding element 40 will be called the "inner edge 444." The proportion of bonding elements 40 between the outer edge 443 and inner edge 444 of the end bonding region 42 is smaller than the proportion of bonding elements 40 between the outer edge 441 and inner edge 442 of the central bonding region 41. Here, the "proportion of the bonding elements 40" refers to the proportion of the number of bonding elements 40 relative to the width of the compressed bonding region 4 when the compressed bonding region 4 is cut along a straight line extending in the width direction, or the proportion of the total length of the range in which the bonding elements 40 are present. Note that the "proportion of the bonding elements 40" may also refer to the proportion of the area of ​​the bonding elements 40 relative to the area of ​​the entire target region.

[0042] By making the proportion of the joining elements 40 in the end joining regions 42 smaller than the proportion of the joining elements 40 in the central joining region 41, the joining elements 40 are sparsely distributed in the end joining regions 42, and the flexibility of the absorbent article 1 can be increased in the front and rear regions of the absorbent article 1, particularly in the outer regions in the width direction of the front and rear regions. As a result, the wearing comfort can be improved in the front and rear regions. Meanwhile, in the central joining region 41, the gathered sheet 32 ​​can be firmly fixed to the center sheet 31, preventing side leakage of body exudates.

[0043] 6, the first elastic members 3221 positioned innermost in the width direction are positioned widthwise more inward than the inner bonding region 431 (first linear region 421). This prevents unnecessary force from being applied by the first elastic members 3221 to the inner side of the first linear region 421 in the width direction while forming pleats up to the inner edge 333 of the gathered sheet 32.

[0044] A portion of the gathered sheet 32 ​​that is more inward in the width direction than the compressed bonding region 4 is not fixed to the center sheet 31. This portion of the gathered sheet 32 ​​can be separated upward from the center sheet 31 (i.e., toward the wearer when the absorbent article 1 is worn). As shown in FIGS. 1 and 3, a first elastic member 3221 is bonded to the inner edge 333 of each side sheet 321 in a stretched state in the longitudinal direction with an adhesive such as a hot melt adhesive. The second and third elastic members 3222, 3223 are spaced outward in the width direction from the first elastic member 3221 and bonded to the inner edge 333 in a stretched state in the longitudinal direction with an adhesive such as a hot melt adhesive. The second elastic member 3222 and the third elastic member 3223 are also spaced apart from each other in the width direction. When the absorbent article 1 is worn, the elastic members 3221-3223 of each gathered sheet 32 ​​contract, causing the region of each gathered sheet 32 ​​that is more inward in the width direction than the central joining region 41 to move upward from the center sheet 31 and rise toward the wearer, as shown in Fig. 3. Furthermore, the contraction of the elastic members 3221-3223 forms gathers in the region of the gathered sheet 32 ​​that is more inward in the width direction than the central joining region 41. This prevents leakage of urine and the like from around the legs in the absorbent article 1. The side sheets 321 and the elastic members 3221-3223 may be joined by a method other than adhesive, such as welding using ultrasonic vibration or heat.

[0045] The absorbent article 1 may be modified in various ways. For example, the backsheet 23 is not limited to a single sheet. It may be a sheet in which multiple sheets are stacked, or in which multiple sheets are joined together in the lengthwise or widthwise direction. The backsheet 23 only needs to have the function of preventing liquid in the absorbent core 22 from leaking to the outside of the absorbent article 1. Typically, the backsheet 23 has a plastic film with countless fine holes formed therein and a nonwoven fabric bonded to the outer surface of the plastic film. The term "backsheet 23" refers to a sheet that covers the lower surface of the absorbent core 22, i.e., the surface facing away from the wearer.

[0046] The term "top sheet 21" refers to a sheet that covers the upper surface of the absorbent core 22, i.e., the surface facing the wearer. In the absorbent article 1, the top sheet 21 includes a center sheet 31 and a gathered sheet 32, but may also include sheets other than these. The center sheet 31 is liquid permeable. However, the entire center sheet 31 does not need to be liquid permeable. The center sheet 31 is also not limited to a single sheet, and may be a sheet in which multiple sheets are stacked together, or in which multiple sheets are joined together in the longitudinal or transverse direction.

[0047] The gathered sheet 32 ​​refers to a sheet having gathers that rise toward the wearer's groin, and the structure and shape of the gathered sheet 32 ​​are not limited to those described above. The gathered sheet 32 ​​may be joined to the lower surface of the center sheet 31 by welding with pressure. In this case, for example, the gathered sheet 32 ​​may be joined to the lower surface of the center sheet 31 in the central joining region 41, and the portions of the gathered sheet 32 ​​folded upward at the edges of the center sheet 31 may be joined to the upper surface of the center sheet 31 in the end joining regions 42.

[0048] The side sheets 321 of the gathered sheet 32 ​​are not limited to being a single sheet folded over, but may be multiple sheets stacked on top of each other, or multiple sheets joined together in the longitudinal or widthwise direction. The gathered sheet 32 ​​prevents body waste from leaking outward in the widthwise direction, and at least the inside of the gathers is hydrophobic. In FIG. 3, the gathered sheet 32 ​​rises from the outside to the inside in the widthwise direction, but it may also be folded outward in the widthwise direction at the central joining region 41 and then rise toward the wearer's groin.

[0049] The number of elastic members in the gathered sheet 32 ​​may be one, two, or four or more. That is, the gathered sheet 32 ​​is provided with at least one elastic member. The elastic member is preferably linear. The term "linear" includes "thin thread-like," "thread-like with a flat cross section," and "tape-like with a flat cross section." In any case, preferably, at least one elastic member does not overlap with the end joining region 42. More precisely, the widthwise position of at least one elastic member does not overlap with the widthwise extent of the end joining region 42. This prevents the contractile force of at least one elastic member from acting on the end joining region 42. Preferably, one elastic member is disposed near and along the inner edge 333 of the side sheet 321 in the widthwise direction. The elastic member may be fixed to the side sheet 321 by welding using ultrasonic vibration or heat.

[0050] When the number of elastic members is one, the outer joining region 432 is a region located outside the elastic members in the width direction. The inner joining region 431 is a region located inside the elastic members in the width direction. When the number of elastic members is two or more, the outer joining region 432 is a region located outside one of the elastic members in the width direction. The inner joining region 431 is a region located inside one of the elastic members in the width direction. More generally, the outer joining region 432 is a region located outside one of the at least one elastic members (the number of the elastic members may be one or more), and the inner joining region 431 is a region located inside one of the elastic members in the width direction. Since the end joining region 42 does not overlap any elastic member, the end joining region 42 is not subjected to direct force from the elastic members. This prevents the end joining region 42, which has hardened due to compression joining, from bending strongly inward (toward the wearer in FIG. 1 ), and improves the wearing comfort of the absorbent article 1. In other words, the discomfort felt when wearing the absorbent article 1 can be reduced compared to when the end joining regions 42 and the elastic members overlap.

[0051] By providing an inner bonding region 431 and an outer bonding region 432 and arranging one or more (preferably two as in the above embodiment) elastic members between these regions in the width direction, the portion of the gathered sheet 32 ​​where gathers are formed can be made to stand up easily. By providing at least one elastic member between the inner bonding region 431 and the outer bonding region 432, the overall shape of the gathers can be stabilized. In the gathered sheet 32, in order to stably stand up the tips of the gathers, it is preferable that the elastic member located most inward in the width direction among the multiple elastic members is located more inward in the width direction than the inner bonding region 431. Furthermore, in order to position the inner bonding region 431 as far inward as possible, it is preferable that the elastic member located second from the inside in the width direction among the multiple elastic members is located between the inner bonding region 431 and the outer bonding region 432 in the width direction. In other words, it is preferable that the number of elastic members located more inward in the width direction than the inner bonding region 431 is one.

[0052] The at least one elastic member may be provided in various ways in the gathered sheet 32, but in any case, the range in which the elastic member is present in the longitudinal direction and the range in which the end joining region 42 is present in the longitudinal direction may or may not overlap.

[0053] In the above embodiment, the compressed and bonded region 4 is formed of numerous dot-like bonding elements 40, but it may also be formed of numerous linear bonding elements or a mesh-like bonding shape. Of course, the center sheet 31 and the gathered sheet 32 ​​may be welded together without any gaps throughout the entire compressed and bonded region 4. In either case, the maximum total length of the compressed and bonded regions 4 in the width direction is preferably 1.25 to 4 times the minimum length. More preferably, the maximum total length is 1.5 to 3 times the minimum length.

[0054] Preferably, the compressed-bonding region 4 is continuous from the front end-bonding region 42 to the rear end-bonding region 42. More preferably, the compressed-bonding region 4 is continuous over the entire length of the topsheet 21 in the longitudinal direction. Here, "continuously existing" the compressed-bonding region 4 includes the case where the bonding elements 40 are spaced apart to the extent that bodily exudates do not leak. Furthermore, the compressed-bonding region 4 does not necessarily have to be continuous; the center sheet 31 and the gathered sheet 32 ​​may be joined using an adhesive at a position where no compressed-bonding region 4 is present. In the above embodiment, the end-bonding region 42 is divided into an inner bonding region 431 and an outer bonding region 432, but the inner bonding region 431 can be omitted. In this case, the outer bonding region 432 and the end-bonding region 42 coincide with each other, and preferably, the outer bonding region 432 and the central bonding region 41 are continuous in the longitudinal direction, so that the entire compressed-bonding region 4 is continuous in the longitudinal direction.

[0055] In the above embodiment, the outer edges 443 of the end joining regions 42 in the width direction are located more inward in the width direction than the inner edge 442 of the central joining region 41 in the width direction. However, the outer edges 443 of the end joining regions 42 in the width direction may simply be located more inward in the width direction than the outer edge 441 of the central joining region 41 in the width direction. In this case, the flexibility of the outer regions in the width direction of the front and / or rear regions of the absorbent article 1 can be improved. Note that the compressed joining region 4 may be a collection of dot-shaped joining elements 40, and therefore, as described above, the edges 441 to 444 refer to lines tangent to the outer or inner sides of the compressed joining region 4. When the edges 441 to 444 are curved, the expression "located inward in the width direction" of one edge relative to the other edge generally means that the entire one edge is located inward in the width direction relative to the entire other edge. However, this also includes cases where an extremely small portion of one edge or an extremely small portion of the other edge does not satisfy the above definition.

[0056] In the above embodiment, the outer bonding region 432 is composed of the second linear region 422 and the third linear region 423 extending in the vertical direction, but it may be composed of three or more linear regions. Furthermore, these linear regions do not have to be connected. In this case, the outermost linear region may be considered to be the outer bonding region 432. By making the end bonding region 42 a collection of linear regions, it is possible to improve the flexibility and breathability of the end bonding region 42. It is preferable that at least the portion of the end bonding region 42 on the end side in the vertical direction is a collection of multiple linear regions extending in the vertical direction.

[0057] Preferably, the center sheet 31 and the pair of gathered sheets 32 are joined only in the compression joining region 4. That is, they are joined only by welding, and no adhesive is used between them. Of course, adhesive may be used as an auxiliary means to join the center sheet 31 and the pair of gathered sheets 32, if necessary.

[0058] The absorbent article 1 described above is merely an example, and the welding of the center sheet 31 and the gathered sheet 32 ​​described in the above embodiment can be used in pants-type disposable diapers, open-type disposable diapers that are secured around the waist with tape, auxiliary absorbents placed inside diapers or diaper-like covers, urine absorption pads, and other various absorbent articles that receive excrement from the wearer.

[0059] The configurations of the above-described embodiment and each modification may be combined as appropriate as long as they are not mutually contradictory. [Explanation of symbols]

[0060] 1. Absorbent articles 4 Compression joint area 11 Center line 21 Topsheet 22 absorbent core 23 Back Seat 31 Center seat 32 Gathered Sheet 40 Joint Elements 42 End joint area 321 Side seat 401 Added Junction Area 421 1st linear region 422 Second linear region 423 Third linear region 431 Medial junction area 432 Outer junction area 443 (position of) outer edge (of end joint area) 444 (position of) inner edge (of end joint area) 445 (along the center edge of the end joint area) line 3221 First elastic member 3222 Second elastic member 3223 Third elastic member

Claims

1. A disposable absorbent article for receiving exudates from a wearer, comprising: A top sheet, Back seat and an absorbent core positioned between the topsheet and the backsheet; Equipped with The top sheet Center seat and a pair of gathered sheets fixed to the center sheet, spaced apart from a center line extending in a longitudinal direction on both sides in a width direction perpendicular to the longitudinal direction; Equipped with Each of the pair of gathered sheets is The side sheet that is long in the vertical direction; an elastic member fixed to an inner region of the side sheet in the width direction and extending in the vertical direction; Equipped with The center sheet and the pair of gathered sheets are joined by welding with pressure in a compression joining region, the compression bonding regions between the center sheet and each gathered sheet include end bonding regions located in the ranges of both ends in the longitudinal direction; The end joint region is an outer bonding region located outside the elastic member in the width direction; an inner bonding region located inside the elastic member in the width direction; Including, The edge of the end joining region on the center side in the longitudinal direction is a discontinuous line, and the edge is inclined toward the center side in the longitudinal direction as it goes outward in the width direction, A disposable absorbent article characterized in that an additional bonding area is present on the outside or inside of the range in the width direction where the edge is discontinued.

2. 10. The disposable absorbent article of claim 1, A disposable absorbent article, wherein the compressed bonded area is a collection of a large number of dot-shaped bonded elements.

3. 10. The disposable absorbent article of claim 1, a plurality of elastic members including the elastic member; A disposable absorbent article, wherein the elastic member located most inward in the width direction among the plurality of elastic members is located more inward in the width direction than the inner bonding region.

4. 4. The disposable absorbent article of claim 3, A disposable absorbent article characterized in that the elastic member second from the inside in the width direction among the plurality of elastic members is located between the inner bonding region and the outer bonding region in the width direction.

5. 10. The disposable absorbent article of claim 1, A disposable absorbent article, wherein the outer bonding region comprises a plurality of linear regions extending in the longitudinal direction.

6. 6. The disposable absorbent article of claim 5, A disposable absorbent article characterized in that the plurality of linear regions are connected on the inside in the longitudinal direction.

7. 7. A disposable absorbent article according to any one of claims 1 to 6, A disposable absorbent article characterized in that it is placed within a diaper or diaper-like cover.

Images