absorbent articles

Abstract

To provide an absorbent article that allows more hygienic post-factum disposition of an absorbent article in which loose stool or the like has been excreted.SOLUTION: There is provided an absorbent article 1 which includes a top sheet 2, a back sheet 3, and an absorbent core 4 disposed therebetween, with side sheets 5 provided on both sides of the top sheet 2 in a width direction. The rear side portion 4C is formed wider than the middle portion, and in the rear side portion 4C, the absorbent core 4 extends outward in the width direction from the outer edge of the top sheet 2 in the width direction. The side sheet 5 is joined to the top sheet 2 at a side joint 6, an inner part of the side sheet 5 in the width direction from the side joint 6 forms a leakage prevention flap 7. The side joint 6 is provided so as to overlap with the rear side portion 4C of the absorbent core 4, and has a weakened portion 6W in the portion that overlaps with the rear side portion 4C of the absorbent core 4.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to absorbent articles such as disposable diapers and urine pads. [Background technology]

[0002] BACKGROUND ART Absorbent articles having a leak-proof flap on the skin-facing side have been known in the past, and Patent Documents 1 and 2, for example, disclose such absorbent articles. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 2019-115459 [Patent Document 2] Japanese Patent Application Laid-Open No. 2009-95636 Summary of the Invention [Problem to be solved by the invention]

[0004] When an absorbent article is used, loose stool may be excreted on the top sheet of the absorbent article. When such an absorbent article is disposed of after use, it is desirable that the absorbent article can be disposed of hygienically. The present invention has been made in view of the above circumstances, and its object is to provide an absorbent article that can be disposed of more hygienically when an absorbent article on which loose stool or the like has been excreted is disposed of after use. [Means for solving the problem]

[0005] The absorbent article of the present invention, which has been able to solve the above-mentioned problems, comprises a top sheet, a back sheet and an absorbent core disposed therebetween, with side sheets provided on both widthwise sides of the top sheet, the absorbent core having a front portion, a rear portion and a middle portion between them in the front-to-rear direction, the rear portion being wider than the middle portion, at the rear portion the absorbent core extends widthwise outward from the outer edge of the top sheet, the side sheets are joined to the top sheet at side joints, and the portions of the side sheets widthwise inward from the side joints form leakproof flaps, the side joints are arranged overlapping the rear and middle portions of the absorbent core, or overlapping the rear portion of the absorbent core and located widthwise outward from the middle portion of the absorbent core, the side joints have weakened portions at the portions overlapping with the rear portions of the absorbent core, and the bond strength of the side joints at the weakened portions is weaker than the bond strength of the side joints at the portions overlapping with the middle portion of the absorbent core or at the portions widthwise outward from that.

[0006] The absorbent article of the present invention has a weakened portion formed at the side joint where the top sheet and side sheet are joined, in the portion overlapping the rear portion of the absorbent core, so that the side joint can be released at the weakened portion. By releasing the side joint at the weakened portion, the released weakened portion can be opened, and a pocket can be formed between the side sheet and the rear portion of the absorbent core as an internal space. The pocket thus formed can be used to pour loose stools that have accumulated on the top sheet when the absorbent article is disposed of after use, allowing the absorbent article to be disposed of more hygienically.

[0007] The side joints can be formed by bonding the side sheets and the top sheet together. The side joints can also be formed by welding the side sheets and the top sheet together. In the weakened portions, the side joints are preferably provided intermittently in the front-to-rear direction, and forming the weakened portions in this manner makes it easier to release the side joints at the weakened portions.

[0008] The side joints are preferably formed in an area within 10 mm from the outer edge of the top sheet in the width direction, so that when loose stools or the like that have accumulated on the top sheet are poured into the space between the side sheets and the rear part of the absorbent core, the loose stools or the like can be more quickly absorbed by the absorbent core.

[0009] The side joints are provided so as to overlap the rear and middle portions of the absorbent core, and the joint strength at the weakened portions of the side joints is preferably smaller than the joint strength at the portions overlapping with the middle portions of the side joints. By forming the side joints in this manner, loose stools and the like that accumulate on the top sheet in the portions overlapping with the middle portion of the absorbent core can be easily guided into the pockets formed at the positions overlapping with the rear portions of the absorbent core.

[0010] The side joints may be configured as joints extending linearly in the front-to-rear direction and arranged in multiple rows in the width direction. In this case, it is preferable that the joint strength of the weakened portion in the joint located most inward in the width direction among the side joints is greater than the joint strength of the weakened portion in the joint located further outward in the width direction. By configuring the side joints in this manner, the side joints at the weakened portions are less likely to be untied when the absorbent article is in use, making it easier for urine, loose stool, etc. excreted on the topsheet to be retained between the leakproof flaps. After use of the absorbent article, by untiing the joint located inward in the width direction in the weakened portions, the joints located further outward in the width direction also become more easily untied. This makes it easier to untied the side joints at the weakened portions.

[0011] The side joints are preferably configured to extend linearly in the front-to-rear direction and be arranged in multiple rows in the width direction, with the most inwardly positioned joints in the width direction being continuously arranged in the front-to-rear direction in the weakened section, and the most outwardly positioned joints in the width direction being intermittently arranged in the front-to-rear direction in the weakened section. By configuring the side joints in this manner, when the absorbent article is in use, urine or loose stool excreted on the topsheet is reliably intercepted by the leak-proof flaps, preventing the urine or loose stool from migrating beyond the weakened sections of the side joints to the outside in the width direction. After the absorbent article is used, however, the weakened sections of the side joints can be easily released.

[0012] A second side joint, where the side sheet is joined to the absorbent core and the back sheet, is preferably provided widthwise outward of the side joint. In this case, the second side joint is provided overlapping the rear portion of the absorbent core and widthwise outward of the middle portion of the absorbent core. The second side joint preferably joins the side sheet and the absorbent core at the portion overlapping the rear portion of the absorbent core and joins the side sheet and the back sheet widthwise outward of the middle portion of the absorbent core. By providing this second side joint, when the side joint at the weakened portion is released after use of the absorbent article, the bond between the side sheet and the back sheet is more likely to be maintained widthwise outward of the middle portion of the absorbent core, making the absorbent article less likely to be damaged. This allows the side joint at the weakened portion to be released more reliably, allowing the absorbent article to be disposed of more hygienically. [Effects of the Invention]

[0013] The absorbent article of the present invention allows loose feces that have accumulated on the top sheet to be disposed of in a hygienic manner when the absorbent article is disposed of after use. [Brief explanation of the drawings]

[0014] [Figure 1]1 shows a plan view of an incontinence pad as an example of an absorbent article of the present invention, viewed from the top sheet side. [Figure 2] 2 shows a cross-sectional view of the absorbent article shown in FIG. 1 taken along line II-II. [Figure 3] 3 shows a cross-sectional view of the absorbent article shown in FIG. 1 taken along the line III-III. [Figure 4] 2 is a diagram showing the positional relationship between the absorbent core and side joining portions of the absorbent article shown in FIG. 1. FIG. [Figure 5] 2 shows a modified example of the rear side portion of the absorbent article shown in FIG. [Figure 6] 1 is a plan view of an incontinence pad as seen from the top sheet side, as another example of the absorbent article of the present invention. [Figure 7] 7 shows a cross-sectional view of the absorbent article shown in FIG. 6 taken along line VII-VII. [Figure 8] 8 shows a cross-sectional view of the absorbent article shown in FIG. 6 taken along line VIII-VIII. DETAILED DESCRIPTION OF THE INVENTION

[0015] The absorbent article of the present invention will be described with reference to the drawings. Note that the present invention is not limited to the embodiments shown in the drawings. FIGS. 1 to 4 show an example of the configuration of a urine pad as an example of the absorbent article of the present invention. FIG. 1 shows a plan view of the absorbent article (urine pad) as seen from the skin-facing side, FIG. 2 shows a cross-sectional view of the absorbent article shown in FIG. 1 taken along II-II, FIG. 3 shows a cross-sectional view of the absorbent article shown in FIG. 1 taken along III-III, and FIG. 4 shows a diagram illustrating the positional relationship between the absorbent core and side joints of the absorbent article shown in FIG. 1. In the drawings of the present application, arrow x represents the width direction, arrow y represents the front-to-back direction, and the direction perpendicular to the plane formed by arrows x and y represents the thickness direction z. In FIG. 1, the upper side of the drawing corresponds to the front side of the absorbent article, and the lower side of the drawing corresponds to the rear side of the absorbent article.

[0016] The absorbent article 1 has a top sheet 2, a back sheet 3, and an absorbent core 4 provided between them. The top sheet 2 is arranged on the skin-facing side of the absorbent core 4, and is a sheet that is located on the wearer's side when the absorbent article 1 is worn. The back sheet 3 is arranged on the outer surface of the absorbent core 4, and is a sheet that is located on the opposite side from the wearer when the absorbent article 1 is worn. Urine and other excretions from the wearer pass through the top sheet 2 and are contained by the absorbent core 4. The back sheet 3 prevents excretions from leaking to the outside.

[0017] The absorbent article 1 has a front-to-back direction y and a width direction x. The front-to-back direction y corresponds to the direction extending from front to back between the crotch of a wearer when the absorbent article 1 is worn. The width direction x refers to a direction on the same plane as the absorbent article 1 and perpendicular to the front-to-back direction y, and corresponds to the left-to-right direction of the wearer when the absorbent article 1 is worn. Furthermore, when the absorbent article 1 is worn by a wearer, the side facing the wearer's skin is referred to as the skin-facing side, and the opposite side is referred to as the non-skin-facing side.

[0018] The top sheet 2 is a sheet member disposed on the skin-facing side of the absorbent core 4, and is provided so as to face the wearer's skin when the absorbent article 1 is worn. The top sheet 2 is preferably liquid permeable. For example, the top sheet 2 may be a nonwoven fabric made from hydrophilic fibers such as cellulose, rayon, cotton, etc.; or a nonwoven fabric made from hydrophobic fibers such as polyolefin (e.g., polypropylene, polyethylene), polyester (e.g., PET), polyamide (e.g., nylon), in which the surfaces of the hydrophobic fibers have been hydrophilized with a surfactant. Alternatively, the top sheet 2 may be a woven fabric, a knitted fabric, a perforated plastic film, etc.

[0019] The backsheet 3 is a sheet member disposed on the non-skin-facing side of the absorbent core 4, and is preferably liquid-impermeable. The backsheet 3 may be made of a nonwoven fabric formed from hydrophobic fibers such as polyolefin (e.g., polypropylene, polyethylene), polyester (e.g., PET), polyamide (e.g., nylon), or a plastic film. Alternatively, the backsheet 3 may be a laminate of a nonwoven fabric and a plastic film.

[0020] The absorbent article 1 has leakage prevention flaps 7 on both sides of the skin-facing side in the width direction x. The provision of the leakage prevention flaps 7 prevents side leakage of urine and the like. The leakage prevention flaps 7 are formed by providing side sheets 5 on both sides of the width direction x of the top sheet 2. Specifically, the side sheets 5 are joined to the top sheet 2 at side joints 6, and the leakage prevention flaps 7 are formed from portions of the side sheets 5 inward in the width direction x from the side joints 6. At the side joints 6, the side sheets 5 are preferably arranged on the skin-facing side of the top sheet 2. The side joints 6 are the starting points for the rise of the leakage prevention flaps 7, and the inner ends of the side sheets 5 in the width direction x are free ends. The side joints 6 are preferably formed so as to extend linearly in the front-to-back direction y. The side joints 6 are also preferably formed continuously or intermittently from the front end to the rear end of the top sheet 2 and / or the side sheets 5.

[0021] The leakage barrier flaps 7 are preferably provided with flap elastic members 8. That is, the flap elastic members 8 are preferably provided inward in the width direction x from the side joints 6 of the side sheets 5. By providing the flap elastic members 8, the inward parts of the side sheets 5 in the width direction x rise toward the wearer's skin, forming the leakage barrier flaps 7. The flap elastic members 8 are provided so as to extend in the front-to-back direction y. Note that the front and rear ends of the leakage barrier flaps 7 may be joined to the top sheet 2 inward in the width direction x from the side joints 6, which causes the leakage barrier flaps 7 to rise by tilting inward in the width direction x, thereby enhancing the leakage prevention effect of urine, loose stool, etc.

[0022] The side sheets 5 are preferably liquid-impermeable and can be made of a sheet material that can be used for the back sheet 3. The side sheets 5 are preferably made of, for example, a liquid-impermeable plastic film or a liquid-impermeable nonwoven fabric.

[0023] When nonwoven fabrics are used for the top sheet 2, back sheet 3, and side sheets 5, it is preferable to use spunbond nonwoven fabrics, air-through nonwoven fabrics, point-bond nonwoven fabrics, melt-blown nonwoven fabrics, air-laid nonwoven fabrics, SMS nonwoven fabrics, etc. The mass per unit area of each of these sheets is 8 g / m 2 More than 10g / m is preferable. 2 More preferably, 40 g / m 2 Less than 30 g / m 2 The following is more preferred:

[0024] The absorbent core 4 is not particularly limited as long as it contains an absorbent material capable of absorbing urine and other bodily waste. For example, a molded body obtained by molding an absorbent material into a predetermined shape can be used as the absorbent core 4. The absorbent core 4 may be covered with a covering sheet such as a paper sheet (e.g., tissue paper or thin paper) or a liquid-permeable nonwoven fabric. Examples of the absorbent material include hydrophilic fibers such as pulp fibers, and water-absorbent resins such as polyacrylic acid, polyaspartic acid, cellulose, and starch-acrylonitrile. Furthermore, the water-absorbent material may include heat-fusible fibers such as polyolefin fibers such as polyethylene and polypropylene, polyester fibers such as PET, and polyamide fibers. These heat-fusible fibers are preferably hydrophilized with a surfactant or the like to enhance their affinity with urine and other wastes.

[0025] The absorbent material preferably contains hydrophilic fibers to increase the absorption rate of urine and the like. Furthermore, the absorbent material preferably contains a water-absorbent resin to increase the absorption capacity. Therefore, the absorbent core 4 preferably contains hydrophilic fibers (particularly pulp fibers) and a water-absorbent resin. In this case, it is preferable to use, for example, a collection of hydrophilic fibers to which the water-absorbent resin is mixed or dispersed.

[0026] The absorbent core 4 may be composed of a single layer or multiple layers, for example, the absorbent core 4 may have an upper absorbent layer and a lower absorbent layer.

[0027] The mass per unit area of the absorbent core 4 is, for example, 60 g / m 2 More than 75g / m 2 More preferably, 80 g / m 2 More preferably, 1000 g / m 2 Preferably less than 950 g / m 2 Less than 900 g / m is more preferable. 2 The mass per unit area of the hydrophilic fibers contained in the absorbent core 4 is more preferably 60 g / m 2 More than 75g / m 2 More preferably, 80 g / m 2 More preferably, 600 g / m 2 Preferably less than 550 g / m 2 Less than 500g / m is more preferable. 2 The following is even more preferred. When the absorbent core 4 is composed of multiple layers, it is preferable that the total mass per unit area of the absorbent cores of the multiple layers or the hydrophilic fibers contained therein is within this range. When the absorbent core 4 has openings or recesses, the mass per unit area of the absorbent core 4 or the hydrophilic fibers contained therein described above refers to the average mass per unit area of the absorbent core 4 or the hydrophilic fibers contained in the absorbent core 4 in the parts other than the openings or recesses.

[0028] The absorbent core 4 has a so-called hourglass or battledore shape. That is, the absorbent core 4 has a front portion 4A, a rear portion 4C, and a middle portion 4B therebetween in the front-to-rear direction y, with at least the rear portion 4C being wider than the middle portion 4B. As shown in FIG. 4 , when the front portion 4A and the rear portion 4C are wider than the middle portion 4B, the absorbent core 4 is formed into an hourglass shape. On the other hand, although not shown in the drawings, when the rear portion 4C is wider than the front portion 4A and the middle portion 4B, the absorbent core 4 is formed into a battledore shape. By forming the absorbent core 4 in this manner, the middle portion 4B of the absorbent core 4 is less likely to be compressed by the wearer's legs, and the absorbent core 4 is less likely to be distorted when the absorbent article 1 is worn.

[0029] When the absorbent core 4 is formed into an hourglass shape, the absorbent core 4 is formed to be widest in the front region 4A and / or the rear region 4C. The length in the width direction x of the front region 4A and the length in the width direction x of the rear region 4C may be the same or different. The intermediate region 4B can be defined as the region of the absorbent core 4 excluding the front and rear ends in the front-rear direction y where the length in the width direction x is narrowest. For example, the intermediate region 4B can be defined as the region between the widest portion of the front half of the absorbent core 4 and the widest portion of the rear half where the length in the width direction x is narrowest. The absorbent core 4 may have a portion in the intermediate region 4B with a constant length in the width direction x. In other words, the outer edge of the absorbent core 4 may have a linear portion extending in the front-rear direction y in the intermediate region 4B. On the other hand, the absorbent core 4 may not have a portion with a constant length in the width direction x in the intermediate region 4B. In this case, the intermediate region 4B is formed at a single point in the front-rear direction y on the absorbent core 4. The length of the intermediate portion 4B in the front-rear direction y is, for example, preferably 50% or less, more preferably 40% or less, of the length of the absorbent core 4 in the front-rear direction y.

[0030] When the absorbent core 4 is formed in a battledore shape, the absorbent core 4 is widest at the rear portion 4C. The absorbent core 4 preferably has a constant length in the width direction x between the front portion 4A and the middle portion 4B, or the front portion 4A is narrower than the middle portion 4B. The front portion 4A and the middle portion 4B can be separated by dividing the portion of the absorbent core 4 forward of the rear portion 4C into two equal parts in the front-to-rear direction y. The absorbent core 4 preferably has a constant length in the width direction x at least in the middle portion 4B, and more preferably has a constant length in the width direction x over at least a portion of the front portion 4A. Therefore, the outer edge of the absorbent core 4 preferably has a straight portion extending in the front-to-rear direction y in the middle portion 4B, and this straight portion preferably extends further toward the front portion 4A. The rear end of the portion of the absorbent core 4 with a constant length in the width direction x can be the boundary between the middle portion 4B and the rear portion 4C.

[0031] The length in the front-to-rear direction y of the rear portion 4C of the absorbent core 4 is, for example, preferably 20% or more, more preferably 30% or more, and preferably 60% or less, more preferably 50% or less of the length in the front-to-rear direction y of the absorbent core 4. By forming the absorbent core 4 in this manner, it becomes easier to form a wider pocket for pouring loose stools, etc., as will be described later.

[0032] The absorbent core 4 may be provided with openings or recesses extending in the front-to-rear direction y (not shown). By providing the openings or recesses in the absorbent core 4, the openings or recesses function as diffusion paths for urine, etc., facilitating diffusion of urine, etc. along the openings or recesses. As a result, urine, etc. is quickly absorbed into the absorbent core 4, and the absorbent core 4 is more likely to contribute to the absorption of urine, etc. over a wide area.

[0033] The openings are provided so as to penetrate the absorbent core 4 in the thickness direction z. On the other hand, the recesses are formed by partially reducing the basis weight (mass per unit area) of the absorbent core 4. In this case, the recesses are preferably formed so that the basis weight of the portions other than the recesses is 70% by mass or less, more preferably 60% by mass or less. When recesses are formed in the absorbent core 4, the recesses are preferably formed on the surface of the absorbent core 4 facing the top sheet 2. When the absorbent core 4 is composed of an upper absorbent layer facing the top sheet 2 and a lower absorbent layer facing the back sheet 3, recesses can be formed on the surface of the absorbent core 4 facing the top sheet 2 by forming an opening in the upper absorbent layer and providing the lower absorbent layer so as to cover the opening.

[0034] The openings or recesses are preferably provided in the center of the width direction x of the absorbent core 4 so as to extend in the front-rear direction y. The center of the width direction x of the absorbent core 4 means a portion that includes the center line of the absorbent core 4 in the width direction x and extends in the front-rear direction y along this center line. The absorbent core 4 may have only one opening or recess, or may have multiple openings or recesses; however, the number of openings or recesses provided in the absorbent core 4 is preferably three or less, more preferably two or less, and even more preferably only one.

[0035] The length of the openings or recesses in the width direction x is preferably 10% or more of the length in the width direction x of the middle portion 4B of the absorbent core 4, more preferably 15% or more, even more preferably 20% or more, and preferably 50% or less, more preferably 45% or less, and even more preferably 40% or less. When two or more openings or recesses are provided, it is preferable that the total length in the width direction x of the openings or recesses in the middle portion 4B of the absorbent core 4 has such a ratio.

[0036] The openings or recesses are preferably formed so as to overlap at least a portion of the middle portion 4B of the absorbent core 4. By forming the openings or recesses in this manner, the openings or recesses are positioned near the wearer's urination area, making it easier for more urine and other excreted material to flow into the openings or recesses. The openings or recesses may further extend to the front portion 4A and / or the rear portion 4C of the absorbent core 4.

[0037] The length of the openings or recesses in the front-rear direction y is preferably 25% or more, more preferably 30% or more, and preferably 70% or less, more preferably 60% or less, and even more preferably 50% or less of the length of the absorbent core 4 in the front-rear direction y. The openings or recesses are preferably provided so as not to come into contact with the outer edge of the absorbent core 4.

[0038] The rear side portions 4C of the absorbent core 4 extend outward in the width direction x from the outer edges of the top sheet 2. It is sufficient that at least a portion of the rear side portions 4C in the front-to-rear direction y extends outward in the width direction x from the outer edges of the top sheet 2 in the width direction x, and other portions of the rear side portions 4C do not have to extend outward in the width direction x from the outer edges of the top sheet 2 in the width direction x.

[0039] In the rear portion 4C of the absorbent core 4, the skin-facing side of the portion extending outward in the width direction x from the outer edge of the top sheet 2 is preferably covered by the side sheet 5. Therefore, the portion of the side sheet 5 outward in the width direction x from the side joint portion 6 preferably extends outward in the width direction x from the outer edge of the top sheet 2 in the width direction x and is disposed facing the absorbent core 4. The portion of the side sheet 5 outward in the width direction x from the side joint portion 6 also preferably extends outward in the width direction x from the outer edge of the absorbent core 4 in the width direction x (particularly the outer edge of the rear portion 4C of the absorbent core 4 in the width direction x), and the side sheet 5 extending outward in the width direction x from the outer edge of the absorbent core 4 in the width direction x is preferably disposed facing the back sheet 3 and bonded to the back sheet 3.

[0040] When the absorbent core 4 is formed as described above, the side joints 6 are provided so as to overlap the rear portion 4C of the absorbent core 4. The side joints 6 may also be provided so as to overlap the front portion 4A of the absorbent core 4. For example, when the absorbent core 4 is formed in an hourglass shape, the side joints 6 are preferably formed in this manner. In this case, it is preferable that the side joints 6 overlap at least the front portion 4A and the rear portion 4C of the absorbent core 4. When the absorbent core 4 is formed in a battledore shape, the side joints 6 may or may not be provided so as to overlap the front portion 4A of the absorbent core 4. In the latter case, the side joints 6 are located outward in the width direction x from the front portion 4A of the absorbent core 4.

[0041] The side joints 6 also preferably overlap the intermediate portion 4B of the absorbent core 4. This allows urine and other excreted material excreted on the top sheet 2 to be quickly absorbed in the intermediate portion 4B of the absorbent core 4. In this case, the entire portion of the intermediate portion 4B of the absorbent core 4 between the leakage prevention flaps 7 on one side and the other side in the width direction x is positioned to overlap with the absorbent core 4, so that when urine and other excreted material excreted between the leakage prevention flaps 7 passes through the top sheet 2, it is quickly absorbed by the absorbent core 4 located underneath. Note that the side joints 6 do not have to overlap with the intermediate portion 4B of the absorbent core 4; in this case, the side joints 6 are positioned outward in the width direction x from the intermediate portion 4B of the absorbent core 4.

[0042] The side joint 6 has a weakened portion 6W where the bond strength between the top sheet 2 and the side sheet 5 is reduced in the portion overlapping the rear portion 4C of the absorbent core 4. This weakens the bond strength of the side joint 6 at the weakened portion 6W, making it possible to release the bond between the top sheet 2 and the side sheet 5 at the weakened portion 6W. By releasing the bond between the side joint 6 at the weakened portion 6W, the absorbent article 1 can form a pocket with the space between the side sheet 5 and the rear portion 4C of the absorbent core 4 as an internal space through the released weakened portion 6W. This pocket can be used to pour loose stools or the like that have accumulated on the top sheet 2 (particularly the portion overlapping the rear portion 4C of the top sheet 2) when the absorbent article 1 is disposed of after use, allowing the absorbent article 1 to be disposed of hygienically. Loose stools or the like that have flowed into the pocket are preferably absorbed in the rear portion 4C of the absorbent core 4, particularly in the portion outward in the width direction x from the side joint 6.

[0043] In the weakened portions 6W, the bond strength of the side joints 6 is smaller than the bond strength of the side joints 6 in the portions overlapping with the intermediate portion 4B of the absorbent core 4. When the side joints 6 are located outward in the width direction x from the intermediate portion 4B of the absorbent core 4, the bond strength of the side joints 6 in the weakened portions 6W is smaller than the bond strength of the side joints 6 in the portions outward in the width direction x from the intermediate portion 4B of the absorbent core 4. By forming the weakened portions 6W in this manner, it becomes easier to release the side joints 6 only in the portions overlapping with the rear portion 4C of the absorbent core 4. Therefore, it is less likely that the side joints 6 will be released in the portions overlapping with the intermediate portion 4B or in the portions of the side joints 6 located outward in the width direction x from the intermediate portion 4B. The bonding strength of the side joint 6 at the weakened portion 6W is preferably 90% or less of the bonding strength at the portion where the side joint 6 overlaps with the intermediate portion 4B or at the portion outward of that in the width direction x, and is preferably 50% or more, more preferably 60% or more, and even more preferably 70% or more.

[0044] The bond strength of the side joint 6 can be measured in accordance with JIS K 6854-3:1999, "Adhesive - Peel Adhesion Strength Test Method (T-Peel)." A test specimen measuring 50 mm in the width direction x and 100 mm or more in the front-to-back direction y is cut from the absorbent article 1 while maintaining the bond at the side joint 6. The bond strength can be determined by measuring the peel strength of the test specimen using a tensile tester. The test specimen is prepared by fixing the top sheet 2 to one chuck and the side sheet 5 to the other chuck. The chuck distance is appropriately set, and the top sheet 2 and side sheet 5 are peeled from each other in the front-to-back direction y at a peel speed (chuck movement speed) of 300 mm / min. The relationship between the peel length and the overlapping positions of the front, middle, and rear sections 4A, 4B, and 4C of the absorbent core 4 is determined in advance. A profile is created with the peel length on the horizontal axis and the peel strength on the vertical axis, and the section where the peel strength is reduced can be identified as the weakened section 6W. The bond strength of the side joint 6 in the weakened section 6W is calculated as the average peel strength of the section identified as the weakened section 6W. The bond strength of the side joint 6 in the section where the side joint 6 overlaps with the middle section 4B or in the section outward of that in the width direction x is calculated as the average peel strength in that section or the peel strength at that point.

[0045] The weakened portions 6W may be formed in at least a portion of the portion where the side joints 6 overlap with the rear portion 4C of the absorbent core 4. The length of the weakened portions 6W in the front-to-rear direction y is, for example, preferably 25% or more, more preferably 30% or more, and even more preferably 35% or more of the length of the portion where the side joints 6 overlap with the rear portion 4C of the absorbent core 4. This makes it easier for loose stools and the like that have accumulated on the top sheet 2 to flow into the space between the side sheet 5 and the rear portion 4C of the absorbent core 4 when the side joints 6 are released at the weakened portions 6W. There are no particular upper limits to the length of the weakened portions 6W in the front-to-rear direction y, and they may be 100% or less of the length of the portion where the side joints 6 overlap with the rear portion 4C of the absorbent core 4, but is preferably 90% or less, more preferably 80% or less, and even more preferably 75% or less. This prevents loose stools and the like from flowing back out of the space when the absorbent article 1 is rolled up and discarded after being poured into the space between the side sheet 5 and the rear portion 4C of the absorbent core 4. The length of the weakened portion 6W in the front-to-rear direction y is preferably, for example, 3 cm or more, more preferably 5 cm or more, and even more preferably 8 cm or more.

[0046] The side joining portions 6 can be formed, for example, by bonding the side sheets 5 and the top sheet 2. In this case, the joining strength at the weakened portions 6W can be reduced by using an adhesive with weaker adhesive strength than other portions, by reducing the amount of adhesive applied, by reducing the adhesive application area, or by narrowing the adhesive application width.

[0047] The side joints 6 can also be formed by welding the side sheets 5 and the top sheet 2. In this case, the welding strength at the weakened parts 6W can be reduced by making the welding area smaller than that of other parts, narrowing the welding width, or welding intermittently. The side sheets 5 and the top sheet 2 can be welded together by heat sealing or ultrasonic welding.

[0048] In the weakened portions 6W, the side joints 6 are preferably provided intermittently in the front-to-rear direction y. Forming the weakened portions 6W in this manner makes it easier to release the side joints 6 at the weakened portions 6W. In this case, the intervals between the side joints 6 at the weakened portions 6W are preferably 0.5 mm or more, more preferably 1 mm or more, and are preferably 3 mm or less, and more preferably 2 mm or less.

[0049] The side joints 6 are preferably formed near the outer edges of the top sheet 2 in the width direction x. Specifically, the side joints 6 are preferably formed in an area within 10 mm, more preferably within 8 mm, and even more preferably within 5 mm, of the outer edges of the top sheet 2 in the width direction x. This makes it easier for loose stools, etc., accumulated on the top sheet 2 to be quickly absorbed by the absorbent core 4 when they are poured into the space between the side sheets 5 and the rear portion 4C of the absorbent core 4. In other words, when the side joints 6 are released at the weakened portions 6W, there is almost no top sheet 2 outside the side joints 6 in the width direction x, and the absorbent core 4 is present without the top sheet 2 in between, making it easier for loose stools, etc., to be quickly absorbed by the absorbent core 4.

[0050] The side joints 6 are arranged to overlap the middle section 4B of the absorbent core 4, and it is preferable that the joint strength of the side joints 6 in the weakened sections 6W is smaller than the joint strength of the side joints 6 in the section overlapping with the middle section 4B of the absorbent core 4. In this case, the side joints 6 are formed to overlap from the rear section 4C to the middle section 4B of the absorbent core 4, so that loose stools and the like that have accumulated in the section on the top sheet 2 that overlaps with the middle section 4B can be easily guided to the pocket formed by overlapping with the rear section 4C of the absorbent core 4 (i.e., the space between the side sheets 5 and the rear section 4C of the absorbent core 4).

[0051] The side joints 6 may be configured as joints extending linearly in the front-to-rear direction y and arranged in multiple rows in the width direction x. An example of such a configuration of the side joints 6 is shown in Fig. 5. Fig. 5 shows a modified example of the rear side of the absorbent article 1 shown in Fig. 1.

[0052] 5, the side joints 6 are composed of joints 6a and 6b formed so as to extend linearly in the front-to-rear direction y, and the joints 6a and 6b are arranged side by side in the width direction x. In this case, each joint constituting the side joints 6 preferably has a weakened portion 6W in the portion overlapping with the rear portion 4C of the absorbent core 4.

[0053] When the side joints 6 are composed of a plurality of joints extending linearly in the front-to-rear direction y, it is preferable that the joint strength of the weakened portion 6W at the joint located most inward in the width direction x among the side joints 6 is greater than the joint strength of the weakened portion 6W at the joint located further outward in the width direction x. In the embodiment shown in Fig. 5, it is preferable that the joint strength of the weakened portion 6W at the joint 6a located inward in the width direction x is greater than the joint strength of the weakened portion 6W at the joint 6b located outward in the width direction x.

[0054] By configuring the side joints 6 as described above, when the absorbent article 1 is used, the joints of the side joints 6 at the weakened parts 6W are less likely to come undone, and urine, loose stools, etc. excreted on the top sheet 2 are more likely to be retained between the leakproof flaps 7. After using the absorbent article 1, by releasing the joint 6a located on the inner side of the weakened parts 6W in the width direction x, the joint 6b located on the outer side of that in the width direction x also becomes more likely to come undone. This makes it easier to release the joints of the side joints 6 at the weakened parts 6W.

[0055] When the side joints 6 are composed of a plurality of joints extending linearly in the front-to-rear direction y, it is also preferable that the joints located most inward in the width direction x among the side joints 6 are provided continuously in the front-to-rear direction y in the weakened portion 6W, and the joints located most outward in the width direction x are provided intermittently in the front-to-rear direction y in the weakened portion 6W. In the embodiment shown in Fig. 5, it is preferable that the joints 6a located inward in the width direction x are provided continuously in the front-to-rear direction y in the weakened portion 6W, and the joints 6b located outward in the width direction x are provided intermittently in the front-to-rear direction y in the weakened portion 6W.

[0056] By configuring the side joint areas 6 as described above, when the absorbent article 1 is in use, urine or loose stool excreted on the top sheet 2 is reliably intercepted by the leakproof flaps 7, preventing the urine or loose stool from migrating beyond the weakened areas 6W of the side joint areas 6 outward in the width direction x. After the absorbent article 1 is used, the joints at the weakened areas 6W of the side joint areas 6 can be easily released. The joints located furthest outward in the width direction x do not necessarily need to join the top sheet 2 and the side sheet 5 at the weakened areas 6W; even in this case, the joints are provided intermittently at the weakened areas 6W. When the side joint areas 6 are configured from three or more joint areas extending linearly in the front-to-rear direction y, the joints located between the joints located furthest inward in the width direction x and the joints located furthest outward in the width direction x may be provided continuously or intermittently in the front-to-rear direction y at the weakened areas 6W.

[0057] When the side joints 6 are composed of multiple joints extending linearly in the front-to-rear direction y, it is preferable that the joint strength of the weakened portion 6W at the joint located most inward in the width direction x is smaller than the joint strength of the joint at the portion where the weakened portion 6W overlaps with the intermediate portion 4B of the absorbent core 4 or at a portion further outward in the width direction x. This makes it easier to release the joint between the top sheet 2 and the side sheet 5 at the weakened portion 6W.

[0058] Although not shown in the drawings, the weakened portion 6W of the side joint portion 6 is formed in the portion overlapping the rear portion 4C of the absorbent core 4, and may also be formed in the portion overlapping the front portion 4A of the absorbent core 4. In this case, the absorbent core 4 is preferably formed in an hourglass shape, and the absorbent core 4 preferably extends in the front portion 4A outward in the width direction x from the outer edge of the top sheet 2. If the weakened portion 6W is formed in the portion of the side joint portion 6 overlapping the front portion 4A of the absorbent core 4, when loose stool spreads on the top sheet 2 to the portion overlapping the front portion 4A, the loose stool can be funneled into the space between the side sheet 5 and the front portion 4A of the absorbent core 4 by releasing the side joint portion 6 at the weakened portion 6W overlapping the front portion 4A. Note that the weakened portion 6W is preferably formed only in the portion overlapping the rear portion 4C of the absorbent core 4.

[0059] The absorbent article 1 may have a second side joint portion provided outward in the width direction x from the side joint portion 6. Configuration examples of absorbent articles configured in this manner are shown in Figs. 6 to 8. Figs. 6 to 8 show configuration examples in which the absorbent article 1 shown in Figs. 1 to 4 has a second side joint portion 9 provided outward in the width direction x from the side joint portion 6. Fig. 6 shows a plan view of the absorbent article (urine pad) as seen from the skin-facing side, Fig. 7 shows a cross-sectional view of the absorbent article shown in Fig. 6 taken along line VII-VII, and Fig. 8 shows a cross-sectional view of the absorbent article shown in Fig. 6 taken along line VIII-VIII.

[0060] In the absorbent article 1 shown in Figures 6 to 8, a second side joint portion 9 where the side sheet 5 is joined to the absorbent core 4 and the back sheet is provided outward in the width direction x from the side joint portion 6. The second side joint portion 9 overlaps the front portion 4A and the rear portion 4C of the absorbent core 4 and is also provided outward in the width direction x from the middle portion 4B of the absorbent core 4. The second side joint portion 9 joins the side sheet 5 to the absorbent core 4 at the portion where it overlaps with the front portion 4A and the rear portion 4C of the absorbent core 4, and joins the side sheet 5 to the back sheet outward in the width direction x from the middle portion 4B of the absorbent core 4. By providing the second side joint portion 9, when the side joint portion 6 at the weakened portion 6W is released after use of the absorbent article 1, the joint between the side sheet 5 and the back sheet is more likely to be maintained outward in the width direction x from the middle portion 4B of the absorbent core 4, making the absorbent article 1 less likely to be damaged. Therefore, the side joints 6 can be more stably released at the weakened portions 6W, allowing for hygienic disposal of the absorbent article 1. When the absorbent core 4 is formed in a battledore shape, it is preferable that the second side joints 9 are not provided overlapping the front portion 4A of the absorbent core 4, but are provided outward in the width direction x from the front portion 4A of the absorbent core 4. In this case, it is preferable that the second side joints 9 join the side sheets 5 and the absorbent core 4 at the portion overlapping with the rear portion 4C, and join the side sheets 5 and the back sheet outward in the width direction x from the front portion 4A and middle portion 4B of the absorbent core 4.

[0061] The second side joint portion 9 can be formed by adhesion or welding, but is preferably formed by adhesion. This makes it easier to join the rear portion 4C (or further the front portion 4A) of the absorbent core 4 to the side sheet 5 at the second side joint portion 9. The second side joint portion 9 may be composed of joint portions extending linearly in the front-rear direction y and arranged in multiple rows in the width direction x. When the side joint portion 6 is formed by adhesion and the second side joint portion 9 is formed by adhesion, the adhesive used for the side joint portion 6 and the second side joint portion 9 may be the same or different.

[0062] When loose stool or the like accumulated on the top sheet 2 is poured into the space between the side sheet 5 and the rear portion 4C of the absorbent core 4, the loose stool or the like is preferably quickly absorbed by the absorbent core 4. To this end, a guide path for loose stool or the like is preferably formed on the skin-facing side of the absorbent core 4 in a portion of the rear portion 4C of the absorbent core 4 outward in the width direction x from the weakened portion 6W (not shown). The guide path can be formed as a groove or a protrusion, and the groove or the protrusion can be formed on the skin-facing side of the absorbent core 4 by forming a recessed portion or a raised portion on the skin-facing side of the absorbent core 4. The groove or the protrusion can be formed, for example, to extend in the front-rear direction y, the width direction x, or a direction oblique to the front-rear direction y. This facilitates the diffusion of loose stool or the like along the guide path, facilitating its rapid absorption by the absorbent core 4. The guide path is preferably provided so as to extend from the portion overlapping the weakened portion 6W outward in the width direction x from the weakened portion 6W.

[0063] The absorbent article of the present invention has been described above with reference to the drawings, but the absorbent article of the present invention is not limited to the urine pad as shown in the drawings, and may also be a disposable diaper, a light incontinence pad, or a sanitary napkin.

[0064] When the absorbent article is a disposable diaper, the disposable diaper is composed of, for example, a front portion, a rear portion, and a crotch portion located between the front and rear portions and having an absorbent core. The front portion corresponds to the portion that contacts the wearer's abdomen when the disposable diaper is worn, and the rear portion corresponds to the portion that contacts the wearer's back when the disposable diaper is worn. The crotch portion is located between the front portion and the rear portion and corresponds to the portion that contacts the wearer's crotch.

[0065] The disposable diaper may be a tape-type disposable diaper or a pants-type disposable diaper. Tape-type disposable diapers are configured, for example, with fastening members provided at both widthwise ends of the rear portion, and can be formed into a pants-like shape when worn by fastening the fastening members to the front abdominal portion. Pants-type disposable diapers have a pants-like shape with a waist opening and a pair of leg openings, and are formed into a pants-like shape before being worn.

[0066] When the absorbent article is a disposable diaper, the disposable diaper is formed, for example, so that a laminate having an absorbent core disposed between a top sheet and a back sheet has a front abdominal portion, a rear dorsal portion, and a crotch portion located therebetween. The disposable diaper can also be constructed by providing an absorbent main body having an absorbent core disposed between a top sheet and a back sheet in the crotch portion of an outer cover member having a front abdominal portion, a rear dorsal portion, and a crotch portion located therebetween. In the latter case, a pants-type disposable diaper can be obtained by forming the outer cover member into a pants-like shape. In either case, the absorbent article of the present invention can be obtained by joining the top sheet and side sheets at side joints as described above and providing weakened portions in parts of the side joints. [Explanation of symbols]

[0067] 1: Absorbent articles 2: Top sheet 3: Back seat 4: absorbent core, 4A: front part, 4B: middle part, 4C: rear part 5: Side seat 6: Side joint, 6W: Weakened section 7: Leak-proof flap 8: Flap elastic member 9: Second side joint

Claims

1. An absorbent article having a top sheet, a back sheet, and an absorbent core disposed therebetween, and side sheets provided on both sides of the top sheet in the width direction, the absorbent core has a front side portion, a rear side portion and an intermediate portion therebetween in the front-to-rear direction, the rear side portion being formed wider than the intermediate portion, and the absorbent core extends outward in the width direction in the rear side portion beyond the outer edge of the top sheet in the width direction, The side sheets are joined to the top sheet at side joining portions, and the widthwise inner portions of the side sheets from the side joining portions form leak-proof flaps, the side joint portions are provided so as to overlap the rear side portions and the middle portion of the absorbent core, or so as to overlap the rear side portions of the absorbent core and be located outward in the width direction from the middle portion of the absorbent core, the side joint portion has a weakened portion at a portion overlapping the rear side portion of the absorbent core, An absorbent article characterized in that the bonding strength of the side joint in the weakened portion is smaller than the bonding strength of the side joint in the portion overlapping with the intermediate portion of the absorbent core or in the portion widthwise outward of that portion.

2. The absorbent article according to claim 1 , wherein the side joints are formed by bonding the side sheets and the top sheet together.

3. The absorbent article according to claim 1, wherein the side joints are formed by welding the side sheets and the top sheet together.

4. The absorbent article according to any one of claims 1 to 3, wherein the side joining portions are provided intermittently in the front-rear direction in the weakened portions.

5. The absorbent article according to any one of claims 1 to 4, wherein the side joining portions are formed in an area within 10 mm from the outer edge of the top sheet in the width direction.

6. the side joint portions are provided so as to overlap the rear side portions and the middle portion of the absorbent core, The absorbent article according to any one of claims 1 to 5, wherein the bond strength of the weakened portion of the side joint is smaller than the bond strength of the portion of the side joint that overlaps with the intermediate portion.

7. The side joint portion is configured by joint portions that extend linearly in the front-rear direction and are arranged in multiple rows in the width direction, An absorbent article as described in any one of claims 1 to 6, wherein the bonding strength of the weakened portion at the side bonding portion located most inward in the width direction is greater than the bonding strength of the weakened portion at the bonding portion located more outward in the width direction.

8. The side joint portion is configured by joint portions that extend linearly in the front-rear direction and are arranged in a plurality of rows in the width direction, An absorbent article as described in any one of claims 1 to 7, wherein the side joints, the joint located most inward in the width direction, are provided continuously in the front-to-back direction in the weakened portion, and the joint located most outward in the width direction, are provided intermittently in the front-to-back direction in the weakened portion.

9. a second side joining portion at which the side sheet is joined to the absorbent core and the back sheet is provided on the outer side of the side joining portion in the width direction, the second side joining portion is provided so as to overlap the rear side portion of the absorbent core and is provided on the outer side in the width direction of the intermediate portion of the absorbent core, An absorbent article as described in any one of claims 1 to 8, wherein the second side joint joins the side sheet and the absorbent core at a portion overlapping the rear portion of the absorbent core, and joins the side sheet and the back sheet widthwise outward of the middle portion of the absorbent core.

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