Absorbent article

Abstract

To make it less likely that a grainy feel of highly absorbent polymer particles is perceived.SOLUTION: An absorbent article comprises an absorbent element 50, which has an absorbent body 56 and a packaging nonwoven fabric 58 that envelops the absorbent body 56, where: the absorbent body 56 has a layer obtained by mixing and accumulating pulp fiber and highly absorbent polymer particles; in the absorbent element 50, grooves 53 which are depressed from a surface of the absorbent element 50 to the inside of the absorbent body 56 and which each have a bottom part 51 that is compressed in the thickness direction are continuous in a grid shape; the grooves 53 have intersection parts 21 and non-intersection parts 22 which are positioned between adjacent intersection parts 21; and, in at least a partial region of the surface of the absorbent element 50, the thickness of the bottom part 51 increases stepwise or continuously from the center of a non-intersection part 22 in the length direction toward an intersection part 21.SELECTED DRAWING: Figure 12

Description

[Technical Field]

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

[0002] In absorbent articles, it is common to use an absorbent body made by mixing and accumulating pulp fibers and superabsorbent polymer particles, and in order to improve the shape retention of such absorbent bodies during and after manufacturing, they are generally built in as an absorbent element wrapped in a wrapping sheet made of crepe paper or the like (see, for example, Patent Documents 1 and 2).

[0003] The absorbent element of an absorbent article is sandwiched between the legs and is subjected to forces in various directions from both sides in the width direction due to leg movements such as walking, so it is required to have a good fit in the crotch area, while also being able to maintain its shape to prevent deformation of the absorbent body due to sagging, cracking, etc. Of course, the absorbent element of a disposable diaper is also required to ensure absorption performance in the crotch area.

[0004] A known method for improving the shape retention of an absorbent body is to provide grooves with bottoms in a grid pattern or the like by compressing the absorbent element in the thickness direction using embossing or other methods (see, for example, Patent Documents 1 and 2). However, if the packaging sheet encasing the absorbent body is made of crepe paper, the crepe paper may tear at the edges of the compressed sections or between adjacent compressed sections when the compressed sections are formed. Furthermore, crepe paper loses strength and becomes more prone to tearing when it is wet after absorbing excrement. If the packaging sheet tears, the superabsorbent polymer particles may escape and reach the surface of the absorbent article, which is undesirable.

[0005] It is also known to use a fine-mesh nonwoven fabric (hereinafter referred to as "packaging nonwoven fabric") as the packaging sheet. However, when using packaging nonwoven fabric, there is a problem in that when the bottom of the grooves formed on the surface of the absorbent element is traced with a finger, the highly absorbent polymer particles give off a gritty feeling. If the user feels this gritty feeling, it is undesirable because it may worsen the wearing comfort or tarnish the product image. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] Japanese Patent Publication No. 2021-000236 [Patent Document 2] Patent No. 6380454 Summary of the Invention [Problem to be solved by the invention]

[0007] Therefore, a main object of the present invention is to make it difficult for the gritty feel of the superabsorbent polymer particles to be transmitted to the user when a packaging nonwoven fabric is used. [Means for solving the problem]

[0008] The absorbent article that solves the above problems is as follows.

[0009] <First aspect> The garment has a crotch portion and a front portion and a rear portion extending forward and rearward from the crotch portion, respectively; an absorbent element including an absorbent body provided at a position including the crotch area and a wrapping nonwoven fabric wrapping the absorbent body; The absorbent body has a layer formed by mixing and accumulating pulp fibers and highly absorbent polymer particles, The absorbent element has a lattice-like continuous groove that is recessed from the surface of the absorbent element to the absorbent body and has a bottom that is compressed in the thickness direction, and The groove has an intersection portion and a non-intersection portion located between adjacent intersection portions, and the thickness of the bottom portion increases stepwise or continuously from the center of the non-intersection portion in the longitudinal direction toward the intersection portion in at least a partial region of the surface of the absorbent element. An absorbent article characterized by:

[0010] (Action and effect) When a packaged nonwoven fabric is used, if a groove having a bottom compressed in the thickness direction is formed on the surface of the absorbent element, the packaged nonwoven fabric and the absorbent body are compressed in the thickness direction at the bottom of the groove, resulting in a relative increase in the amount of superabsorbent polymer particles on the surface of the absorbent body and nearby areas, and due to the reduction in cushioning properties and densification in the thickness direction of the packaged nonwoven fabric and the absorbent body, the superabsorbent polymer particles are held in a state where they are difficult to move on the surface of the hardened absorbent body and nearby areas, and are covered by the thinned packaged nonwoven fabric. As a result, when you run your finger over the bottom of the groove, you can feel the gritty texture of the superabsorbent polymer particles. The problem here is that the bottoms of the grooves are located far from the skin, i.e., in areas that are difficult for the user to touch directly or indirectly via another sheet, so the sensation of the superabsorbent polymer particles is generally difficult for the user to feel. However, when the grooves are formed in a lattice pattern, the packaging nonwoven fabric is pulled in two directions at the corners facing the intersections at the bottoms of the grooves, making the corners particularly thin, and as a result, the intersections at the bottoms of the grooves are more likely to come into direct or indirect contact with the skin than non-intersections. In contrast, in the present absorbent article, (a) the thickness of the bottom portion is gradually or continuously increased from the longitudinal center of the non-intersecting portion toward the intersecting portion (i.e., the degree of compression of the bottom portion is reduced from the longitudinal center of the non-intersecting portion toward the intersecting portion, and the density of the bottom portion is decreased), thereby preventing a decrease in thickness at the corners of the groove bottoms facing the intersecting portions, and making it less likely that the intersecting portions of the groove bottoms will come into contact with the user's skin. Therefore, compared to when the thickness of the groove bottoms is approximately constant, the gritty feeling of the superabsorbent polymer particles is less likely to be transmitted to the user. Furthermore, (b) at the intersections at the bottoms of the grooves, which are more likely to come into contact with the user's skin, an increase in the amount of superabsorbent polymer particles on and near the surface of the absorbent is suppressed, and a decrease in cushioning properties and densification in the thickness direction of the packaging nonwoven fabric and absorbent are also suppressed. Therefore, even if the intersections at the bottoms of the grooves come into contact with the user's skin, the gritty feeling of the superabsorbent polymer particles is weak, so the gritty feeling of the superabsorbent polymer particles is less likely to be conveyed to the user. Furthermore, the grooves, which extend from the surface of the absorbent element into the absorbent body and have bottoms compressed in the thickness direction, are arranged in a grid pattern, thereby ensuring liquid diffusion properties and shape retention of the absorbent body.

[0011] <Second aspect> The basis weight of the pulp fibers in the absorbent body is 100 to 450 g / m 2 and the weight ratio of pulp fibers to superabsorbent polymer particles in the absorbent body is 30:70 to 70:30; The maximum thickness of the absorbent element is 4 to 35 mm, the thickness of the bottom portion at the longitudinal center of the non-intersecting portion is 15 to 35% of the maximum thickness of the absorbent element; The thickness of the bottom portion at the intersection is 1.4 to 6 times the thickness of the bottom portion at the center in the longitudinal direction of the non-intersection portion. 1. An absorbent article according to a first embodiment.

[0012] (Action and effect) The material composition of the absorbent body and the degree of compression of the bottom of the groove can be determined as appropriate, but it is preferable that they are within the range of this embodiment.

[0013] <Third aspect> The width of the bottom is 1 to 3 mm, The grooves are formed in a diagonal lattice pattern, each of which has a first portion inclined at 40 to 50 degrees clockwise relative to the front-rear direction in a plan view and a second portion inclined at 40 to 50 degrees counterclockwise relative to the front-rear direction in a plan view. An absorbent article according to a second embodiment.

[0014] (Action and effect) The dimensions and shape of the grooves etc. can be determined as appropriate, but forming them in a diagonal grid pattern as in this embodiment is preferable because it not only improves the shape retention and flexibility of the absorbent body but also improves liquid diffusion. However, forming the grooves in this pattern is preferable because it minimizes thickness reduction at the corners facing the intersections of the groove bottoms.

[0015] <Fourth aspect> The packaging nonwoven fabric has one or more meltblown layers and one or more protective layers, The basis weight of the packaging nonwoven fabric is 10 to 17 g / m 2 and The constituent fibers of the protective layer have an average fiber diameter of 10 to 25 μm, The constituent fibers of the meltblown layer are fibers having an average fiber diameter of 5 μm or less, With five of the packaging nonwoven fabrics stacked together, the air permeability measured in accordance with JIS L 1096:2010 using Method A (Fragile method) is 25.5 to 70.0 cm 3 / cm 2 s, The packaging nonwoven fabric has a standard elongation rate in the front-to-rear direction specified in JIS L 1913:2010 of 20 to 100%, The standard elongation rate in the width direction as specified in JIS L 1913:2010 is 20 to 110%. The absorbent article according to any one of the first to third aspects.

[0016] (Action and effect) If the packaging nonwoven fabric is not stretchable, not only will it be difficult to form firm grooves, but the flexibility of the absorbent element will also decrease. Furthermore, if the fiber structure of the packaging nonwoven fabric is sparse, the superabsorbent polymer particles will be more likely to slip out. Therefore, it is preferable to use a packaging nonwoven fabric that is sufficiently thin and stretchable, as in this embodiment, and that has a dense meltblown layer. When uniform grooves are formed using such a packaging nonwoven fabric, the gritty feel of the superabsorbent polymer particles is likely to be transmitted to the user. However, by having the above-mentioned characteristics (a) and (b), it is possible to improve the shape retention and flexibility of the absorbent body while suppressing the gritty feel of the superabsorbent polymer particles from being transmitted to the user. The breathability also serves as an index of how easily the highly absorbent polymer particles can escape.

[0017] <Fifth aspect> The basis weight of the packaging nonwoven fabric is 15 to 17 g / m 2 That is, An absorbent article according to a fourth embodiment.

[0018] (Action and effect) If the packaging nonwoven fabric is not stretchable, not only will it be difficult to form firm grooves, but the flexibility of the absorbent element will also decrease. Furthermore, if the fiber structure of the packaging nonwoven fabric is sparse, the superabsorbent polymer particles will be more likely to escape. Therefore, it is preferable to use a packaging nonwoven fabric that is sufficiently thin and stretchable, as in this embodiment, and that has a dense meltblown layer. These points are as described above. However, when grooves with bottoms at compressed portions compressed in the thickness direction are formed in a grid pattern on the surface of the absorbent element to improve the shape retention of the absorbent body and the liquid diffusion properties along the front-rear and width directions of the absorbent element, the superabsorbent polymer particles may escape when the surface of the packaged nonwoven fabric is subjected to frictional forces at and near the intersections of the grooves. One of the main reasons for this is thought to be that the packaged nonwoven fabric is stretched in two directions (the direction intersecting one adjacent groove and the direction intersecting the other groove) at and near the intersections, making the thickness thinner than other areas and increasing the fiber gaps. Another main reason is thought to be that the absorbent body is compressed in the thickness direction at and near the bottoms of the grooves, resulting in a relative increase in the amount of superabsorbent polymer particles at and near the surface (i.e., that may escape from the absorbent body). In contrast, if the packaged nonwoven fabric of this embodiment is used and the thickness of the bottom portion is increased stepwise or continuously from the longitudinal center of the non-intersecting portion toward the intersecting portion (i.e., the degree of compression of the bottom portion is reduced from the longitudinal center of the non-intersecting portion toward the intersecting portion, and the density of the bottom portion is reduced), it is possible to suppress the expansion of the packaged nonwoven fabric on both sides of the groove and the resulting expansion of the interfacial gaps and reduction in thickness from the longitudinal center of the non-intersecting portion toward the intersecting portion, compared to when this is not done. Therefore, by combining a dense packaged nonwoven fabric having a certain basis weight or more with the aforementioned change in bottom thickness, as in this embodiment, it becomes difficult for the superabsorbent polymer particles contained in the absorbent body to pass through the packaged nonwoven fabric, even at the intersecting portions of the grooves and their vicinity.

[0019] <Sixth aspect> The absorbent body has a covering layer that covers the surface of the absorbent body and is made up of an accumulation of only pulp fibers. The absorbent article according to any one of the first to fifth aspects.

[0020] (Action and effect) The presence of a coating layer as in this embodiment is preferable because it makes it difficult for the superabsorbent polymer particles to escape from the surface of the absorbent body.

[0021] <Seventh aspect> The packaged nonwoven fabric has a back surface portion located on the back side of the absorbent body, a first front surface portion that continues from the back surface portion, wraps around one side edge of the absorbent body to reach the front side of the absorbent body, and a second front surface portion that continues from the back surface portion, wraps around the other side edge of the absorbent body to reach the front side of the absorbent body, the first front-side portion and the second front-side portion have laminated portions that overlap each other, All the grooves are formed in the laminated portion. An absorbent article according to any one of the first to sixth aspects.

[0022] (Action and effect) When configured as in this embodiment, it is also possible to prevent the high-absorbent polymer particles from escaping from the surface of the absorbent element.

[0023] <Eighth aspect> The absorbent element has a middle portion, excluding both widthwise ends, that is not covered by other members over the entire front-rear direction, and the packaging nonwoven fabric is exposed on the surface of the absorbent article. The absorbent article according to any one of the fifth to seventh aspects.

[0024] (Action and effect) As described above, since it is possible to prevent the escape of superabsorbent polymer particles through the packaging nonwoven fabric, it is possible to omit components such as a top sheet that covers the surface of the absorbent element, which are provided in conventional absorbent articles, thereby achieving significant cost reductions. [Effects of the Invention]

[0025] The present invention provides the following advantages when using a packaging nonwoven fabric: the gritty feel of the superabsorbent polymer particles is less likely to be felt by the user. [Brief explanation of the drawings]

[0026] [Figure 1] FIG. 2 is a plan view showing the inner surface of the pants-type disposable diaper in an unfolded state. [Figure 2]FIG. 2 is a plan view showing the outer surface of the pants-type disposable diaper in an unfolded state. [Figure 3] 2 is a cross-sectional view taken along line 2-2 of FIG. 1. [Figure 4] 3 is a cross-sectional view of FIG. 1 taken along line 3-3. [Figure 5] 1(a) is a cross-sectional view taken along line 4-4 in FIG. 1, and FIG. 1(b) is a cross-sectional view taken along line 5-5 in FIG. [Figure 6] FIG. 1 is a perspective view of a pants-type disposable diaper. [Figure 7] FIG. 2 is a plan view showing the outer surface of the inner body in the deployed state together with the outline of the outer body. [Figure 8] FIG. 2 is a plan view showing the surface of the absorbent body together with the outline of the packaging sheet. [Figure 9] FIG. 2 is a cross-sectional view of an absorbent element. [Figure 10] FIG. [Figure 11] FIG. 2 is an enlarged view of a main part of the surface of the absorbent element. [Figure 12] 11. (a) is a cross-sectional view taken along line 7-7 in FIG. 11, and (b) to (d) are cross-sectional views corresponding to the cross-section 7-7 in FIG. [Figure 13] FIG. 3 is a cross-sectional view showing the absorbent element in a state before the absorbent body is wrapped in a wrapping sheet. [Figure 14] FIG. 2 is a cross-sectional view showing the absorbent element in a state after the absorbent body has been wrapped in a wrapping sheet and before the grooves have been formed. [Figure 15] FIG. 10 is a cross-sectional view of another absorbent element. [Figure 16] FIG. 10 is a plan view of another absorbent element. [Figure 17] 2 is a cross-sectional view of another example corresponding to the cross section 2-2 of FIG. 1. FIG. [Figure 18] 3 is a cross-sectional view of another example corresponding to the cross section 3-3 of FIG. 1. FIG. [Figure 19] FIG. 10 is a cross-sectional view of another absorbent element. [Figure 20] FIG. 10 is a plan view showing another example of the absorbent body. [Figure 21] 1A to 1C are schematic diagrams illustrating a method for manufacturing an absorbent element. [Figure 22] FIG. 2 is a perspective view of a protrusion of the anvil roll. [Figure 23] FIG. 1 is a schematic diagram of a test apparatus. [Figure 24] FIG. 10 is an explanatory diagram of a friction pattern showing only the essential parts. DETAILED DESCRIPTION OF THE INVENTION

[0027] Below, a pants-type disposable diaper will be described in detail as an example of a disposable diaper, with reference to the accompanying drawings. Adjacent components in the thickness direction are fixed or joined as needed, in addition to the fixed or joined portions described below, in the same manner as known diapers. The dotted patterns in the cross-sectional diagram indicate adhesives such as hot melt adhesives used as the fixing or joining means. Hot melt adhesives can be applied by known methods, such as slot coating, continuous or dotted bead coating, spiral, Z-shaped, or wavy spray coating, or pattern coating (transfer of hot melt adhesive using a relief printing method). Alternatively or in addition to this, hot melt adhesive can be applied to the outer surface of the elastic member to fix the elastic member to the adjacent member. Hot melt adhesives include, for example, EVA-based, adhesive rubber-based (elastomer-based), polyolefin-based, and polyester / polyamide-based types, but no particular limitations apply. Material welding methods, such as heat sealing and ultrasonic sealing, can also be used to fix or join the components. In areas where liquid permeability in the thickness direction is required, adjacent components in the thickness direction are fixed or joined in an intermittent pattern. For example, when such intermittent fixing or joining is performed using a hot melt adhesive, intermittent pattern application such as a spiral, Z-shape, or wavy pattern can be suitably used. When applying to an area greater than the application width of a single nozzle, intermittent pattern application such as a spiral, Z-shape, or wavy pattern can be performed with or without gaps in the width direction. Material welding methods such as heat sealing and ultrasonic sealing can also be used to join the components.

[0028] Furthermore, as the nonwoven fabric in the following description, known nonwoven fabrics can be used as appropriate depending on the location and purpose. The constituent fibers of the nonwoven fabric can be selected without particular limitation, for example, synthetic fibers such as polyolefins (e.g., polyethylene or polypropylene), polyesters, and polyamides (including single-component fibers as well as core-sheath and other composite fibers), regenerated fibers (e.g., rayon or cupra), and natural fibers (e.g., cotton), and mixtures of these can also be used. To increase the flexibility of the nonwoven fabric, it is preferable to use crimped fibers as the constituent fibers. Furthermore, the constituent fibers of the nonwoven fabric can be hydrophilic fibers (including fibers made hydrophilic by a hydrophilizing agent), hydrophobic fibers, or water-repellent fibers (including fibers made water-repellent by a water-repellent agent). Furthermore, nonwoven fabrics are generally classified into staple fiber nonwoven fabrics, long fiber nonwoven fabrics, spunbond nonwoven fabrics, meltblown nonwoven fabrics, spunlace nonwoven fabrics, thermal bond (air-through) nonwoven fabrics, needle-punched nonwoven fabrics, point-bond nonwoven fabrics, laminated nonwoven fabrics (including SMS nonwoven fabrics and SMMS nonwoven fabrics in which a meltblown layer is sandwiched between spunbond layers), etc. depending on the fiber length, sheet formation method, fiber bonding method, and laminated structure, and any of these nonwoven fabrics can be used.

[0029] 1 to 6 show an example of a pants-type disposable diaper. This pants-type disposable diaper includes a rectangular front outer body 12F constituting a front waist-surrounding portion, a rectangular rear outer body 12B constituting a rear waist-surrounding portion, and an inner body 200 provided inside the outer bodies 12F and 12B so as to extend from the front outer body 12F through the crotch region M to the rear outer body 12B. Side seals 12A are formed by joining both sides of the front outer body 12F and both sides of the rear outer body 12B, and thus an opening formed by the front and rear ends of the outer bodies 12F and 12B serves as a waist opening WO through which the wearer's waist passes. The portions of the inner body 200 on both widthwise sides, surrounded by the lower edges of the outer bodies 12F and 12B and the side edges of the inner body 200, serve as leg openings LO through which the legs pass. The inner body 200 absorbs and retains excrement such as urine, and the outer bodies 12F and 12B support the inner body 200 against the wearer's body. Furthermore, the symbol Y indicates the total length of the diaper in the unfolded state when the front outer body 12F and the rear outer body 12B are not joined by the side seal 12A (the front-to-rear length from the edge of the waist opening WO of the front body F to the edge of the waist opening WO of the rear body B), and the symbol X indicates the total width of the diaper in the unfolded state.

[0030] This pants-type disposable diaper has a waist region T defined as the front-to-back range having the side seals 12A (the front-to-back range from the waist opening WO to the top of the leg openings LO), and an intermediate region L defined as the front-to-back range of the portion forming the leg openings LO (between the front-to-back region having the side seals 12A of the front body F and the front-to-back region having the side seals 12A of the back body B). The portions of the front exterior body 12F and the rear exterior body 12B located in the waist region T, i.e., the front waist portion and the rear waist portion, can be conceptually divided into a "waist portion" W that forms the edge of the waist opening, and a "lower waist portion" U that is the portion below this. Typically, when the front and rear waist regions have a boundary where the stretch stress in the width direction WD changes (e.g., where the thickness or elongation rate of the elastic member changes), the waist region W is the portion closer to the waist opening WO than the boundary closest to the waist opening WO. When no such boundary exists, the waist region W is the waist extension 12E extending further toward the waist opening WO than the absorbent body 56 or inner body 200. Their front-to-rear lengths vary depending on the product size and can be determined as appropriate. For example, the waist region W may be 15 to 40 mm, and the lower waist region U may be 65 to 120 mm. Meanwhile, both side edges of the middle region L are constricted in a U-shape or curved shape to fit around the wearer's legs, and these are the areas into which the wearer's legs are inserted. As a result, the pants-type disposable diaper in its unfolded state has a generally hourglass shape overall.

[0031] (interior body) The inner body 200 can have any shape, but in the illustrated example, it is a rectangle with the long sides forming both side edges. As shown in Figures 3 to 5, the inner body 200 comprises a top sheet 30 that faces the body, a liquid-impermeable sheet 11, and an absorbent element 50 interposed between them, and is the part that performs the absorption and retention functions. Reference numeral 40 denotes an intermediate sheet (second sheet) that is provided between the top sheet 30 and the absorbent element 50 in order to quickly transfer liquid that has permeated the top sheet 30 to the absorbent element 50, and reference numeral 60 denotes rising gathers 60 that extend from both sides of the inner body 200 so as to come into contact with the wearer's legs in order to prevent excrement from leaking out the sides of the inner body 200.

[0032] (Top sheet) The top sheet 30 is liquid-permeable, and examples thereof include a perforated or non-perforated nonwoven fabric and a perforated plastic sheet. The top sheet 30 may consist of a single sheet, or a laminated sheet obtained by bonding two or more sheets together. Similarly, the top sheet 30 may consist of a single sheet, or two or more sheets in the planar direction.

[0033] The side edges of the top sheet 30 may be folded back to the back of the absorbent element 50 at the side edges of the absorbent element 50, or may not be folded back and may extend out to the sides of the side edges of the absorbent element 50. Alternatively, the overall width of the top sheet 30 may be made shorter than the overall width of the absorbent element 50, so that both side edges of the top sheet 30 are positioned above the absorbent element 50 and both side edges of the surface of the absorbent element 50 are exposed on the surface of the diaper.

[0034] In order to prevent the top sheet 30 from shifting relative to the backing member, it is desirable to secure the top sheet 30 to the adjacent backing member using a material welding joining means such as heat sealing or ultrasonic sealing, or a hot melt adhesive. In the illustrated example, the top sheet 30 is secured to the front surface of the intermediate sheet 40 and the surface of the portion of the packaging nonwoven fabric 58 that is located on the front side of the absorbent body 56 by a hot melt adhesive applied to the back surface of the top sheet 30.

[0035] (middle seat) In order to quickly transfer liquid that has passed through the top sheet 30 to the absorbent body 56, an intermediate sheet (also called a "second sheet") 40, which has a faster liquid permeability rate than the top sheet 30, can be provided. This intermediate sheet 40 is intended to quickly transfer liquid to the absorbent body, improving the absorption performance of the absorbent body 56 and preventing the phenomenon of absorbed liquid "backflowing" from the absorbent body. The intermediate sheet 40 can also be omitted. In this case, the top sheet 30 can also be omitted.

[0036] Examples of the intermediate sheet 40 include the same material as the top sheet 30, spunlace nonwoven fabric, spunbond nonwoven fabric, SMS nonwoven fabric, pulp nonwoven fabric, a mixed sheet of pulp and rayon, point-bond nonwoven fabric, and crepe paper. Air-through nonwoven fabric is particularly preferred because of its bulkiness. For the air-through nonwoven fabric, it is preferable to use composite fibers with a core-sheath structure, and in this case, the resin used for the core may be polypropylene (PP), but polyester (PET) with high rigidity is preferred. The basis weight is 17 to 80 g / m 2 is preferable, and 25 to 60 g / m 2 The thickness of the raw material fibers of the nonwoven fabric is preferably 2.0 to 10 dtex. In order to make the nonwoven fabric bulky, it is also preferable to use eccentric fibers, hollow fibers, or eccentric and hollow fibers as all or part of the raw material fibers.

[0037] In the illustrated example, the intermediate sheet 40 is positioned in the center and is shorter than the width of the absorbent body 56, but it may be provided across the entire width. The length of the intermediate sheet 40 in the front-to-rear direction may be the same as the entire length of the diaper, the same as the length of the absorbent element 50, or may be within a short length range centered on the liquid-receiving region.

[0038] In order to prevent the intermediate sheet 40 from shifting relative to the backing member, it is desirable to fix the intermediate sheet 40 to the backing member adjacent thereto by a material welding joining means such as heat sealing or ultrasonic sealing, or by a hot melt adhesive. In the illustrated example, the intermediate sheet 40 is fixed to the surface of the portion of the packaging nonwoven fabric 58 that is located on the front side of the absorbent body 56 by a hot melt adhesive applied to the back side of the intermediate sheet 40.

[0039] (Liquid-impermeable sheet) The material of the liquid-impermeable sheet 11 is not particularly limited, but examples thereof include a plastic film made of a polyolefin resin such as polyethylene or polypropylene, a laminated nonwoven fabric in which a plastic film is provided on the surface of a nonwoven fabric, and a laminated sheet in which a nonwoven fabric or the like is overlaid and bonded to a plastic film. A liquid-impermeable and moisture-permeable material, which is preferred from the viewpoint of preventing stuffiness, is preferably used for the liquid-impermeable sheet 11. A widely used moisture-permeable plastic film is a microporous plastic film obtained by kneading an inorganic filler into a polyolefin resin such as polyethylene or polypropylene, forming the sheet, and then stretching the sheet in a uniaxial or biaxial direction. In addition, nonwoven fabrics using microdenier fibers, nonwoven fabrics whose leak-proofing properties have been enhanced by reducing the voids in the fibers through the application of heat or pressure, and sheets that have been made liquid-impermeable without using a plastic film by coating with a highly absorbent resin or a hydrophobic resin or a water-repellent agent can also be used as the liquid-impermeable sheet 11, but it is preferable to use a resin film in order to obtain sufficient adhesive strength when bonding with the cover nonwoven fabric 13 described below via a hot melt adhesive.

[0040] The liquid-impermeable sheet 11 is made to have a width that fits behind the absorbent element 50 as shown in the figure, and in order to improve leakproofness, it can also be made to wrap around both sides of the absorbent element 50 and extend to both sides of the absorbent element 50 on the side of the top sheet 30. The appropriate width of this extension is about 5 to 20 mm on each side.

[0041] (Absorption element) The absorbent element 50 has an absorbent body 56 and a wrapping nonwoven fabric 58 that wraps the entire absorbent body 56 .

[0042] (absorber) The absorbent body 56 is a mixture of pulp fibers and highly absorbent polymer particles. The basis weight of the pulp fibers is, for example, 100 to 450 g / m 2 It can be about.

[0043] The term "superabsorbent polymer particles" includes not only "particles" but also "powder." The superabsorbent polymer particles used in this type of disposable diaper can be used as is. For example, when sieved using a 500 μm standard sieve (JIS Z8801-1:2006) (shaking for 5 minutes), the percentage of particles remaining on the sieve is preferably 30% by weight or less. Furthermore, when sieved using a 180 μm standard sieve (JIS Z8801-1:2006) (shaking for 5 minutes), the percentage of particles remaining on the sieve is preferably 60% by weight or more.

[0044] The material of the superabsorbent polymer particles is not particularly limited, but a water absorption capacity of 40 g / g or more is preferred. Examples of superabsorbent polymer particles include starch-based, cellulose-based, and synthetic polymer-based materials, such as starch-acrylic acid (salt) graft copolymers, saponified starch-acrylonitrile copolymers, crosslinked products of sodium carboxymethylcellulose, and acrylic acid (salt) polymers. The shape of the superabsorbent polymer particles is preferably the commonly used powder-like form, but other shapes can also be used.

[0045] The highly absorbent polymer particles preferably have a water absorption rate of 70 seconds or less, particularly 40 seconds or less. If the water absorption rate is too slow, the liquid supplied into the absorbent body 56 tends to flow back out of the absorbent body 56, which is known as backflow.

[0046] Furthermore, the highly absorbent polymer particles preferably have a gel strength of at least 1000 Pa. This effectively prevents the sticky feeling after absorbing liquid, even when the absorbent body 56 is bulky.

[0047] The basis weight of the highly absorbent polymer particles can be determined appropriately depending on the absorption amount required for the application of the absorbent body 56. Therefore, although it cannot be generalized, it is generally in the range of 50 to 350 g / m 2 The polymer weight can be 50 g / m 2 If it is less than 350g / m, it will be difficult to ensure sufficient absorption. 2 Above this, the effect saturates.

[0048] The ratio of pulp fibers to superabsorbent polymer particles in the absorbent body 56 is not particularly limited, and can be, for example, a weight ratio of pulp fibers to superabsorbent polymer particles of 40:60 to 65:35. A weight ratio of pulp fibers to superabsorbent polymer particles of 50:50 to 65:35 is particularly preferred because it provides excellent shape retention, absorption speed, and ease of forming grooves 53 (described below) in the absorbent body 56, while reducing the risk of the superabsorbent polymer particles slipping out. While the superabsorbent polymer particles are preferably uniformly distributed throughout the absorbent body 56, it is preferable that the content of the superabsorbent polymer particles decrease stepwise or continuously from the back side to the front side to prevent the superabsorbent polymer particles from slipping out to the front side. It is particularly preferred to provide a coating layer 56c composed solely of pulp fibers to cover the surface of the absorbent body 56, as shown in FIG. 19 . Even when providing this coating layer 56c composed solely of pulp fibers, the ratio of fibers to superabsorbent polymer particles is preferably within the aforementioned range.

[0049] The thickness 56t of the absorber 56 is not particularly limited, but may be, for example, 3 to 15 mm.

[0050] The absorbent body 56 may extend across both the front and rear of the crotch region M so as to include the crotch region M. In the case of a pants-type disposable diaper such as this example, it is preferable that the absorbent body 56 extends to or near the peripheral edge of the inner body 200 in both the front-to-rear direction LD and the width direction WD. The reference symbol 56X indicates the overall width of the absorbent body 56.

[0051] To ensure an adequate absorption capacity in the crotch region M, it is preferable that the shape of the absorber 56 is a substantially rectangular shape as shown in the example of Fig. 8. Furthermore, to improve the fit in the crotch region M, it is also possible to form the absorber 56 in a constricted shape, in which the width of the absorber 56 in the crotch region M is narrower than the front and rear sides, as shown in the example of Fig. 20(a). In this case, to ensure an adequate absorption capacity in the crotch region M, it is preferable that the width n1 of the narrowest part of the absorber 56 in the crotch region M is 0.85 times or more the overall width 56X of the absorber 56.

[0052] The crotch region M refers to the area in the front-to-back direction LD where the absorbent body 56 has a constricted portion 56n (described later); if the absorbent body 56 does not have a constricted portion 56n but the diaper has a constricted portion in its unfolded state as in the illustrated example, the crotch region M refers to the area in the front-to-back direction LD where the constricted portion of the diaper's outer shape is located (between the front exterior body 12F and the rear exterior body 12B in the illustrated example); if the diaper does not have any constricted portions, the crotch region M refers to the area located in the center in the front-to-back direction LD where the dimension in the front-to-back direction LD is 20-30% of the total length of the product. The portions extending forward and backward from the crotch region M are the front portion and the rear portion, respectively.

[0053] (Low basis weight part) As shown in FIGS. 8 and 20, the absorbent body 56 may have elongated low basis weight portions 56L extending in the front-to-back direction LD on both sides of the width direction WD in the crotch region M, or may not have low basis weight portions 56L as shown in FIGS. 1 to 6. The low basis weight portions 56L refer to portions with a low basis weight and do not include portions that are merely compressed in the thickness direction but have no change in basis weight, such as the bottoms 51 of grooves 53 described below. The low basis weight portions 56L can be slits penetrating the thickness direction, but are preferably recesses with a low accumulation of pulp fibers and superabsorbent polymer particles, as shown in the illustrated example, because this facilitates ensuring sufficient absorption. The recesses may be formed on either the front or back surface of the absorbent body 56. Providing such low basis weight portions 56L in the absorbent body 56 encourages bending of the absorbent body 56 along the low basis weight portions 56L, improving the fit of the absorbent element 50 in the crotch region M. The total basis weight of the pulp fibers and superabsorbent polymer particles in the low basis weight portion 56L may be less than the total basis weight of the pulp fibers and superabsorbent polymer particles in the portions other than the low basis weight portion 56L, and may be, for example, 0.1 to 0.5 times the total basis weight of the pulp fibers and superabsorbent polymer particles in the portions other than the low basis weight portion 56L.

[0054] As long as the low basis weight portion 56L is elongated in the front-to-rear direction LD, it may extend linearly along the front-to-rear direction LD, or it may be curved so that it is positioned laterally as it approaches both sides in the front-to-rear direction LD, as in the illustrated example. The front and rear ends of the low basis weight portion 56L may have any suitable shape. For example, it may be linear as in the example shown in FIG. 20(a), or it may be curved (e.g., semicircular) as in the example shown in FIG. 8, or it may have rounded corners at both ends and a linear intermediate portion (not shown). The width m1 of the low basis weight portion 56L may be determined as appropriate, and may be 0.04 to 0.1 times the width n1 (meaning the overall width 56X in the case of a rectangle) of the narrowest portion of the crotch region M of the absorbent body 56. The width m1 of the low basis weight portion 56L may be constant or variable along its length. The dimensions and arrangement of the low basis weight portion 56L in the front-to-rear direction LD may be determined as appropriate. For example, the dimension m2 of the low basis weight portion 56L in the front-to-back direction LD can be 50 to 120%, and more preferably 50 to 80%, of the dimension of the crotch region M in the front-to-back direction LD. The low basis weight portion 56L may be contained within the crotch region M, or may extend to the front, back, or both the front and back of the crotch region M.

[0055] The low basis weight portion 56L is provided on each side (left and right sides) of the crotch region M in the width direction WD, and also in the center of the width direction WD as shown in Figures 8 and 20(a), or alternatively, it may be provided with only one on each side of the crotch region M in the width direction WD as shown in Figure 20(b), or only one in the center of the width direction WD (not shown).

[0056] (groove) As shown in Figures 3, 4, and 9, the absorbent element 50 preferably has a grid-like continuous groove 53, which extends from the surface of the absorbent element 50 into the absorbent body 56 and has a bottom 51 compressed in the thickness direction. By providing a grid-like continuous groove 53 on the surface of the absorbent element 50, the liquid diffusibility and the shape retention of the absorbent body 56 can be improved. The bottom 51 of the groove 53 is a high-density portion compressed by pressure (direct pressure) to a substantially uniform thickness. Hereinafter, the portion other than the bottom 51 will be referred to as the non-compressed portion 52. The non-compressed portion 52 is thicker and less dense than the bottom 51. However, even in the non-compressed portion 52, the absorbent body 56 and the packaging nonwoven fabric 58 deform near the bottom 51 as if pulled by the deformation of the bottom 51, resulting in an increase in density toward the bottom 51. As long as the non-compressed portion 52 is thicker and less dense than the bottom 51, it may be entirely compressed in the thickness direction simultaneously with, before, or after the compression process for forming the bottom 51. The shape and arrangement of the non-compressed portions 52 are determined according to the shape and arrangement of the bottom portion 51 .

[0057] The bottoms 51 of the grooves 53 arranged in a grid pattern on the surface of the absorbent element 50 have intersections 21 and non-intersections 22 located between adjacent intersections 21, and it is preferable that in at least a partial region of the surface of the absorbent element 50, the thickness of the bottoms 51 increases stepwise or continuously from the center in the longitudinal direction of the non-intersections 22 (the continuous direction XD of the grooves 53) toward the intersections 21, as shown in Figures 11 and 12. Note that the darker dotted areas in the figures represent areas where the bottoms 51 of the grooves 53 are relatively thin and compressed at a relatively high density, and the lighter dotted areas represent areas where the bottoms 51 of the grooves 53 are relatively thick and compressed at a relatively low density.

[0058] In the example shown in Figure 12(a), the bottom 51 of the longitudinal middle portion 24 of the non-intersecting portion 22 has a substantially constant first thickness t1, and the bottom 51 of the other portions, i.e., the intersection portion 21 and the portion 23 of the non-intersecting portion 22 that is closer to the intersection portion 21, has a substantially constant second thickness t2 that is thicker than the first thickness t1. In the example shown in Figure 12(b), the non-intersecting portion 22 has a substantially constant first thickness t1 over almost the entire longitudinal direction, and the bottom 51 of the intersection portion 21 has a substantially constant second thickness t2 that is thicker than the first thickness t1 over almost the entire longitudinal direction. These are examples in which the thickness of the bottom 51 changes in stages.

[0059] On the other hand, in the example shown in FIG. 12(c), the bottom 51 of the central portion 24 in the longitudinal direction of the non-intersecting portion 22 has a substantially constant first thickness t1, and almost the entire bottom 51 of the intersecting portion 21 has a substantially constant second thickness t2 that is thicker than the first thickness t1. 3 12(d) shows an example in which the thickness of bottom portion 51 changes continuously in the longitudinal direction of groove 53 (the bottom surface of groove 53 has a wavy shape such as a sine wave in a cross section along the continuous direction of groove 53) so that the thickness of bottom portion 51 is minimum (first thickness t1) approximately at the center of the longitudinal direction of non-intersection portion 22 and maximum (second thickness t2) approximately at the center of intersection portion 21. These are examples in which the thickness of bottom portion 51 changes continuously.

[0060] In such a region of varying thickness of bottom portion 51, (a) the thickness of bottom portion 51 increases stepwise or continuously from the center of the longitudinal direction of non-intersecting portion 22 toward intersection portion 21 (i.e., the degree of compression of bottom portion 51 decreases from the center of the longitudinal direction of non-intersecting portion 22 toward intersection portion 21, and the density of bottom portion 51 decreases), thereby suppressing a decrease in thickness of the corners of non-compressed portion 52 facing intersection portion 21 of bottom portion 51 of groove 53, and making intersection portion 21 of bottom portion 51 of groove 53 less likely to come into contact with the user's skin. Therefore, compared to when the thickness of bottom portion 51 of groove 53 is approximately constant, the gritty feeling of the superabsorbent polymer particles is less likely to be transmitted to the user. Furthermore, (b) at the intersection 21 of the bottom 51 of the groove 53, which is more likely to come into contact with the user's skin, an increase in the amount of superabsorbent polymer particles on and near the surface of the absorbent 56 is suppressed, and a decrease in the cushioning properties and densification in the thickness direction of the packaging nonwoven fabric 58 and the absorbent 56 are also suppressed. Therefore, even if the intersection 21 of the bottom 51 of the groove 53 comes into contact with the user's skin, the gritty feeling of the superabsorbent polymer particles is weak, so the gritty feeling of the superabsorbent polymer particles is less likely to be transmitted to the user.

[0061] The bottom thickness changing region may extend over the entire region having the grooves 53 (i.e., all of the intersections 21 and non-intersections 22 may have the thickness change), or it may extend over only a part of the region having the grooves 53. In particular, considering that the gritty feeling of the superabsorbent polymer particles is likely to occur in areas subjected to external forces such as friction (the same applies to the escape of the superabsorbent polymer particles from the surface of the packaging nonwoven fabric 58), when the absorbent element 50 is divided into three regions 50C, 50L, and 50R in the width direction WD (for example, divided into three equal parts) and grid-like grooves 53 are formed across these three regions 50C, 50L, and 50R as shown in Fig. 8, it is preferable that at least the regions 50L and 50R on both sides be the bottom thickness changing region. Furthermore, considering that an increase in the thickness of bottom portion 51 at intersections 21 is detrimental to liquid diffusion and the shape retention of absorbent body 56, it is desirable that bottom portion 51 in central region 50C have first thickness t1 throughout the entire grid-like grooves 53. Furthermore, central region 50C is the bottom thickness varying region described above, and with reference to the example in Figure 16 described later, both side regions 50L, 50R may have grooves 53 that do not intersect (no recesses (portions compressed in the thickness direction) in the portions corresponding to intersections 21), or the area of ​​unit frames 51f of grooves 53 in both side regions 50L, 50R may be made larger (for example, 1.5 times or more) than the area of ​​unit frames 51f of grooves 53 in central region 50C. In this case, the gritty feel of the superabsorbent polymer particles is less likely to be conveyed to the user, and liquid diffusion in the width direction WD is low, making side leakage less likely.

[0062] When the portion 24 having the first thickness t1 and the portion 23 having the second thickness t2 have lengths in the direction XD of the groove 53 (i.e., excluding cases where the thickness of the bottom portion 51 changes continuously), the length 23L of the portion 23 having the second thickness t2 in the direction XD of the groove 53 is preferably 0.3 to 1 time, and particularly preferably 0.5 to 0.9 time, the longitudinal dimension 22L of the non-intersection portion 22. The length 24L of the portion 24 having the first thickness t1 in the direction XD of the groove 53 is preferably 1 time or more, particularly preferably 1.1 times or more, the length 21L of the intersection portion 21 in the direction XD of the groove 53 (the distance between a pair of adjacent non-intersection portions 22 sandwiching the intersection portion 21), and is preferably less than 0.75 times the longitudinal dimension 22L of the non-intersection portion 22.

[0063] Such an absorbent element 50 can be manufactured by a known method such as embossing. For example, the first step is to form an absorbent body 56 by mixing and accumulating pulp fibers and highly absorbent polymer particles, and the second step is to wrap the entire absorbent body 56. nonwoven fabric 21 , the package 50P is passed between an anvil roll 90 having numerous protrusions 91 arranged at intervals on its outer circumferential surface in the same pattern as the bottoms 51 of the grooves 53, and a smooth roll 92 having a cylindrical surface (without protrusions 91) facing the anvil roll 90, with the surface that will become the back surface of the absorbent element 50 facing the anvil roll 90, and the portions of the package 50P that are sandwiched between the numerous protrusions 91 of the anvil roll 90 and the smooth roll 92 are pressed to form grooves 53 having bottoms 51 compressed in the thickness direction, thereby manufacturing the absorbent element 50 having grooves 53. Either or both of the anvil roll 90 and the smooth roll 92 may be pressed while heated, or without being heated. In the third step, only the portion of the packaging body 50P that is sandwiched between the numerous protrusions 91 of the anvil roll 90 and the smooth roll 92 may be pressed, or the entire packaging body 50P may be pressed while the portion that is sandwiched between the numerous protrusions 91 of the anvil roll 90 and the smooth roll 92 is pressed to the deepest extent.

[0064] When forming the groove 53 of the example shown in Figure 12(a), the pattern of the protrusions 91 of the anvil roll 90 is as shown in Figure 22(a), and when forming the groove 53 of the example shown in Figure 12(c), the pattern of the protrusions 91 of the anvil roll 90 is as shown in Figure 22(b). Of these anvil rolls 90, the bottom 51 of the first thickness t1 is formed by pressing the first protrusions 91a, and the bottom 51 of the first thickness t2 is formed by pressing the second protrusions 91b. Second thickness t2 Further, an inclined protrusion 91c connecting the first protrusion 91a and the second protrusion 91b forms an inclined bottom 51 connecting the bottom 51 of the first thickness t1 and the bottom 51 of the second thickness t2.

[0065] The thickness 50t of the absorbent element 50 and the thickness 51t (t1, t2) of the groove bottom 51 can be determined as appropriate, but for example, the maximum value of the thickness 50t of the absorbent element 50 (maximum value of the thickness of the uncompressed portion 52) can be 4 to 35 mm, and is preferably 5 to 13 mm. The first thickness t1 of the bottom 51 can be determined as appropriate, but is usually preferably 15 to 35% of the maximum value of the thickness 50t of the absorbent element 50. The second thickness t2 of the bottom 51 is preferably 1.4 to 6 times the first thickness t1, and more preferably 2 to 4 times.

[0066] One preferred pattern of the grooves 53 is a diagonal lattice pattern, as shown in Figures 10 and 11, which is composed of first portions 51a extending in a direction tilted 40 to 50 degrees clockwise relative to the front-to-rear direction LD in plan view and second portions 51b extending in a direction tilted 40 to 50 degrees counterclockwise relative to the front-to-rear direction LD in plan view. In this case, the shape of the unit frame 51f is approximately rhombic. The dimensions of the unit frame 51f can be determined as appropriate, but for example, the dimension 51x of the unit frame 51f in the width direction WD can be approximately 15 to 20 mm. Furthermore, the dimension 51y of the unit frame 51f in the front-to-rear direction LD can be approximately 15 to 20 mm.

[0067] The width 51w of the bottom 51 of the groove 53 can be determined as appropriate, but in normal cases it is preferably about 1 to 3 mm, and is preferably approximately constant in the direction in which the groove 53 continues.

[0068] The area ratio of the bottoms 51 of the grooves 53 to the surface of the absorbent element 50 can be determined as appropriate, but if the bottoms 51 of the grooves 53 are arranged too densely, the absorbent element 50 will become hard, so it is preferable to set it to about 10 to 14%.

[0069] As shown in the example, it is preferable to multiply the number of corners of the non-compressed portion 52 at the intersection 21 and reduce the angle of one corner, in which case the intersection 21 refers to the portion formed by connecting all of the corners (the octagonal portion shown in the figure). Similarly, it is also preferable to round the corners into an arc (not shown), in which case the intersection 21 refers to the portion formed by connecting the endpoints of the arcs that face each other across the groove.

[0070] The region where the grooves 53 are continuous in a grid pattern may be the entire surface of the absorbent element 50 or a part of it. When the grooves 53 are continuous in a grid pattern, liquid diffusion is improved, but if they are located at the front end or rear end of the absorbent element 50, there is a risk of front or rear leakage becoming more likely. Therefore, for example, as shown in Figure 16(a), the absorbent element is divided into three parts: a middle region 50M in the front-to-rear direction LD including the crotch region M, a region 50F further forward than this, and a region 50B further rearward, and grid-like grooves 53 are provided across all of these regions, and the areas of the unit frames 51f in the front region 50F and the rear region 50B are reduced to the middle region 50M. of It is preferable that the area is larger (for example, about 1.5 to 3 times) than the area of ​​the unit frame 51f in the region 50M. Also, as shown in Fig. 16(b), it is also preferable that the intermediate region 50M is provided with continuous grooves 53 in a lattice pattern, while the front region 50F and the rear region 50B are provided with grooves 53 but the grooves 53 do not intersect (there are no recesses (portions compressed in the thickness direction) in the portions corresponding to the intersections 21).

[0071] (Packaging non-woven fabric) The packaging nonwoven fabric 58 has a meltblown layer formed of fibers having an average fiber diameter of 5 μm or less, and has an air permeability of 25.5 to 70.0 cm 2 measured by Method A (Fragile method) in accordance with JIS L 1096:2010 when five layers are stacked. 3 / cm2 The air permeability of the nonwoven fabric 58 when five layers are stacked is 40.0 to 70.0 cm. 3 / cm 2 ·s is more preferable. This breathability can be measured, for example, using an air permeability measuring device (model AP-500KZ4) manufactured by Daiei Kagaku Seiki Seisakusho. As is well known, the meltblown layer is a nonwoven fabric layer formed by accumulating ultrafine fibers obtained by spinning a molten resin raw material into a high-velocity hot gas stream and bonding the fibers together. The constituent fibers have an average fiber diameter of 10 μm or less, long fiber lengths of 30 μm or more, and small fiber spacing. The average fiber diameter of the fibers in the meltblown layer is preferably 2.5 μm or less. The average fiber diameter of the fibers in the meltblown layer can be 1 μm or more, and is preferably 2 μm or more.

[0072] The total basis weight of the meltblown layer (if there are multiple meltblown layers, the sum of the basis weights of all layers) and the total thickness (if there are multiple meltblown layers, the sum of the thicknesses of all layers) can be determined appropriately. For example, the total basis weight of the meltblown layer is 0.3 to 6 g / m 2 The total thickness of the meltblown layer can be 0.01 to 0.35 mm.

[0073] As long as the packaging nonwoven fabric 58 has a meltblown layer, it may be a single-layer nonwoven fabric consisting of only a meltblown layer, but a laminated nonwoven fabric having one or more meltblown layers and one or more protective layers is preferred. The laminated nonwoven fabric may be produced by overlapping and forming the webs that make up each layer in order, and then bonding the fibers and each layer together by thermal bonding (point bonding, hot air bonding, etc.), or by forming the nonwoven fabric layers that make up each layer individually (web formation and fiber bonding), and then overlapping them and bonding the layers together thermally or with an adhesive.

[0074] A spunbond layer can be suitably used as the protective layer. As is well known, a spunbond layer is a nonwoven fabric layer formed by collecting filaments obtained by extruding (spinning) a molten resin material from a nozzle and bonding the fibers together. The average fiber diameter of the constituent fibers is larger than that of the meltblown layer, and the fiber length is also longer than that of the meltblown layer. More specifically, an SMS nonwoven fabric, SSMMS nonwoven fabric, or the like, in which at least one meltblown layer is sandwiched between a pair of spunbond layers on the front and back, can be suitably used as the packaging nonwoven fabric 58. The material of the constituent fibers of each layer is not particularly limited. For example, polypropylene fibers, polyethylene / polypropylene bicomponent fibers, etc. can be used for the meltblown layer, and polypropylene fibers, polyethylene / polypropylene bicomponent fibers, etc. can be used for the spunbond layer.

[0075] The fiber diameter, total basis weight (sum of basis weights of all layers when there are multiple protective layers), and total thickness (sum of thicknesses of all layers when there are multiple protective layers) of the constituent fibers of the protective layer can be appropriately determined. For example, the constituent fibers of the protective layer preferably have an average fiber diameter of 10 to 25 μm (particularly 15 to 20 μm). The total basis weight of the protective layer is preferably 5 to 17.5 g / m. 2 (Especially 5-10g / m 2 ), and the total thickness of the protective layer is preferably 0.01 to 0.35 mm (particularly 0.1 to 0.2 mm).

[0076] The basis weight and thickness of the packaging nonwoven fabric 58 can be determined as appropriate. For example, the total basis weight of the packaging nonwoven fabric 58 is 10 to 17 g / m 2 The thickness of the wrapping nonwoven fabric 58 is preferably 0.2 to 0.8 mm.

[0077] If the packaging nonwoven fabric 58 is not stretchable, not only will it be difficult to form firm grooves 53, but the flexibility of the absorbent element 50 will also decrease. Therefore, it is preferable that the packaging nonwoven fabric 58 have a standard elongation, as specified in JIS L 1913:2010, in the front-to-rear direction LD of 20 to 100%, particularly 30 to 60%, and a standard elongation, as specified in JIS L 1913:2010, in the width direction WD of 20 to 110%, particularly 50 to 70%. When uniform grooves are formed using such a nonwoven fabric, the gritty feel of the superabsorbent polymer particles is likely to be conveyed to the user. However, by providing the bottom thickness varying region described above, it is possible to improve the shape retention and flexibility of the absorbent body 56 while suppressing the gritty feel of the superabsorbent polymer particles from being conveyed to the user.

[0078] Furthermore, when the nonwoven fabric used as the packaging nonwoven fabric 58 has one or more meltblown layers made of fibers with an average fiber diameter of 5 μm or less and one or more protective layers made of fibers with an average fiber diameter of 10 to 25 μm and has the above-mentioned elongation rate, the basis weight of the packaging nonwoven fabric 58 is 15 to 17 g / m 2 In addition, employing the aforementioned thickness-changing region of bottom portion 51 is preferable because it makes it difficult for superabsorbent polymer particles to escape to the outside of packaging nonwoven fabric 58. That is, if the thickness of bottom portion 51 increases stepwise or continuously from the longitudinal center of non-intersecting portion 22 toward intersection portion 21 (i.e., the degree of compression of bottom portion 51 decreases from the longitudinal center of non-intersecting portion 22 toward intersection portion 21, and the density of bottom portion 51 decreases), it is possible to suppress the expansion of packaging nonwoven fabric 58 on both sides of groove 53 and the resulting expansion of fiber gaps and reduction in thickness from the longitudinal center of non-intersecting portion 22 toward intersection portion 21, compared to when this is not the case. Therefore, by combining a dense packaging nonwoven fabric 58 having a certain basis weight or more with the aforementioned thickness change of bottom portion 51, it becomes difficult for superabsorbent polymer particles contained in absorber 56 to pass through packaging nonwoven fabric 58 even at intersection portion 21 of groove 53 and its vicinity.

[0079] The packaging structure of the packaging nonwoven fabric 58 can be determined as appropriate, but from the standpoint of ease of manufacturing and preventing leakage of superabsorbent polymer particles from the front and rear edges, it is preferable to wrap it around the front, back, and both side surfaces of the absorbent body 56 in a cylindrical shape, as shown in the example shown, with the front and rear edges extending beyond the front and rear of the absorbent body 56, and to join the overlapping wound parts and the overlapping parts of the extending front and rear parts using a joining means such as a hot melt adhesive or material welding.

[0080] In particular, as shown in Figure 15, the packaging nonwoven fabric 58 has a back portion 58s located on the back side of the absorbent body 56, a first front side portion 58a that continues from the back side portion 58s, wraps around one side edge of the absorbent body 56 to reach the front side of the absorbent body 56, and a second front side portion 58b that continues from the back side portion 58s, wraps around the other side edge of the absorbent body 56 to reach the back side of the absorbent body 56, and the first front side portion 58a and the second front side portion 58b have a stacked portion 58W in which they overlap each other, and it is preferable that all grooves are formed in the stacked portion 58W, as this can also prevent superabsorbent polymer particles from escaping from the surface of the absorbent element 50.

[0081] In order to reduce costs, the absorbent element 50 may have no other sheet layers such as paper or nonwoven fabric (which may of course have an adhesive layer) between the packaging nonwoven fabric 58 and the absorbent body 56, as shown in Figure 9, or may have other sheet layers on at least one side of the front or back of the absorbent body 56.

[0082] (Get up and gather) The rising gathers 60 have rising portions 68 that rise from the sides of the inner body 200, and these rising portions 68 come into contact with the area from the wearer's groin through the legs to the buttocks to prevent side leakage. In the illustrated example, the rising gathers 60 have a base side portion 60B that rises obliquely toward the center in the width direction, and a tip side portion 60A that rises obliquely from the intermediate portion toward the outside in the width direction, but the present invention is not limited to this and can be modified as appropriate, such as one that rises toward the center in the width direction as a whole.

[0083] More specifically, the rising gathers 60 in the illustrated example are formed by folding a strip-shaped gathered sheet 62, having a length equal to the longitudinal length of the inner body 200, in two by folding back the leading end in the width direction WD, and by fixing a plurality of elongated gathered elastic members 63 between the folded-back portion and the sheet in the vicinity thereof in a stretched state along the longitudinal direction at intervals in the width direction WD. A base end portion of the rising gathers 60 opposite the leading end (the end portion opposite the folded-back portion of the sheet in the width direction WD) serves as a root portion 65 fixed to the side portion of the inner body 200, and the portion other than the root portion 65 serves as a main body portion 66 (the portion on the folded-back portion side) extending from the root portion 65. The main body portion 66 further has a root portion 60B extending toward the center in the width direction and a tip portion 60A folded back at the leading end of the root portion 60B and extending outward in the width direction. The front-to-rear end portions of the main body portion 66 are formed as fallen portions 67 which are fixed in a fallen state to the side surfaces of the top sheet 30, while the front-to-rear intermediate portion between them is formed as an unfixed raised portion 68, and a gathered elastic member 63 extending along the front-to-rear direction LD is fixed in a stretched state to at least the tip portion of this raised portion 68.

[0084] In the rising gathers 60 configured as described above, the contractile force of the gather elastic member 63 causes the rising portions 68 to rise up so as to come into contact with the skin as shown by the arrows in Fig. 3. In particular, when the base portion 65 is located on the back side of the inner body 200, the rising portions 68 rise up so as to open outward in the width direction in the crotch region and its vicinity, so that the rising gathers 60 come into contact with the surrounding legs with a full surface, improving fit. The base portion 65 can also be fixed to the front side of the inner body 200, for example, to the surfaces of both side portions of the top sheet 30.

[0085] In a bent structure such as the illustrated example of the rising gathers 60, in which the main body portion 66 is composed of a base portion 60B extending toward the center in the width direction and a tip portion 60A folded back at the tip of the base portion 60B and extending outward in the width direction, the tip portion 60A and the base portion 60B are joined in a folded state at the fallen portion 67, and the base portion 60B is joined in a folded state to the topsheet 30. To join the opposing surfaces at the fallen portion 67, at least one of various application methods of hot melt adhesive and material welding means such as heat sealing and ultrasonic sealing can be used. In this case, the joining of the base portion 60B and the topsheet 30 and the joining of the tip portion 60A and the base portion 60B may be performed by the same means or by different means. For example, it is preferable to join the root side portion 60B and the top sheet 30 with a hot melt adhesive, and to join the tip side portion 60A and the root side portion 60B with material welding.

[0086] As the gathered sheet 62, a nonwoven fabric that is soft and has excellent uniformity and hiding power, such as a spunbond nonwoven fabric (SS, SSS, etc.), an SMS nonwoven fabric (SMS, SSMMS, etc.), or a meltblown nonwoven fabric, and that has been subjected to a water-repellent treatment with silicone or the like as necessary, can be suitably used. In this case, the fiber weight of the nonwoven fabric is 10 to 30 g / m 2 Although not shown, a waterproof film can be interposed between the two folded gathered sheets 62.

[0087] The gathered elastic members 63 can be made of rubber thread or the like. When spandex rubber thread is used, the thickness is preferably 470 to 1240 dtex, more preferably 620 to 940 dtex. The elongation percentage of the gathered elastic members 63 in the attached state is preferably 150 to 350%, more preferably 200 to 300%. The number of gathered elastic members 63 is preferably 2 to 6, more preferably 3 to 5. The appropriate spacing between the gathered elastic members 63 is 3 to 10 mm. With this configuration, the gathered elastic members 63 can easily contact the skin over their entire surface within the range where they are arranged. The gathered elastic members 63 may be arranged not only on the tip side but also on the base side.

[0088] In the rising portion 68 of the rising gathers 60, at least one of various application methods of hot melt adhesive and material welding, such as heat sealing or ultrasonic sealing, can be used to bond the inner and outer layers of the gathered sheet 62 together and to secure the gathered elastic member 63 sandwiched therebetween. Since bonding the entire inner and outer layers of the gathered sheet 62 together reduces flexibility, it is preferable to leave the areas other than the adhesive portion of the gathered elastic member 63 unbonded or to only weakly bond them. In the illustrated example, hot melt adhesive is applied only to the outer peripheral surface of the gathered elastic member 63 using an application means such as a comb gun or a SureWrap nozzle, and the gathered elastic member 63 is sandwiched between the inner and outer layers of the gathered sheet 62. This results in a structure in which the gathered elastic member 63 is secured to the inner and outer layers of the gathered sheet 62 and the inner and outer layers of the gathered sheet 62 are secured together solely by the hot melt adhesive applied to the outer peripheral surface of the gathered elastic member 63.

[0089] Similarly, the fallen portion 67 can be fixed by at least one of various application methods of hot melt adhesive and material welding such as heat sealing or ultrasonic sealing.

[0090] (Side flap) 1 to 4, etc., side flaps 70 extending out to the sides of the absorbent body 56 are provided on both sides of the inner body 200, and it is preferable that side stretchable regions SG that stretch in the front-to-rear direction are formed in these side flaps 70. The side flaps 70 in the illustrated example have one or more elongated side elastic members 73 arranged along the front-to-rear direction LD and spaced apart from one another, a first sheet layer 71 facing the outside of the side elastic member 73, and a second sheet layer 72 facing the inside of the side elastic member 73.

[0091] The sheet material forming the first sheet layer 71 and the second sheet layer 72 is not particularly limited, and any suitable nonwoven fabric can be selected, such as the nonwoven fabric that can be used for the above-mentioned rising gathers 60 and the above-mentioned outer bodies 12F, 12B. In the illustrated example, the first sheet layer 71 and the second sheet layer 72 are formed by extending the gathered sheet 62 of the rising gathers 60, as will be described later. In this case, the front and rear ends of the side flaps 70 coincide with the front and rear ends of the rising gathers 60 (i.e., the front and rear ends of the inner body 200 in this case).

[0092] The side elastic members 73 are not particularly limited, and can be elongated elastic members similar to the gathered elastic members 63 described above. The extension percentage of the side elastic members 73 in the attached state is preferably 150 to 350%, more preferably 200 to 270%. The number of side elastic members 73 is preferably 2 to 16, more preferably 6 to 10. The appropriate spacing between the side elastic members 73 is 5 to 10 mm.

[0093] The side elastic members 73 are fixed to the first sheet layer 71 and the second sheet layer 72. Various application methods of hot melt adhesive HM or material welding methods such as heat sealing and ultrasonic sealing can be used to bond the first sheet layer 71 and the second sheet layer 72 together and to secure the side elastic members 73 sandwiched between them. Because a large bonded area between the first sheet layer 71 and the second sheet layer 72 reduces flexibility, it is preferable to leave the portions of the side elastic members 73 unbonded or to only weakly bond them. In the illustrated example, the hot melt adhesive HM is applied only to the outer peripheral surfaces of the side elastic members 73 using an application method such as a comb gun or a SureWrap nozzle, and then the side elastic members 73 are sandwiched between the first sheet layer 71 and the second sheet layer 72. The hot melt adhesive HM applied only to the outer peripheral surfaces of the side elastic members 73 secures the side elastic members 73 to the first sheet layer 71 and the second sheet layer 72 and secures the first sheet layer 71 and the second sheet layer 72 together.

[0094] In the illustrated example, the sheet material constituting the first sheet layer 71 and the sheet material constituting the second sheet layer 72 are folded back at the side edges of the side flaps 70, and these folded back portions are fixed (the bag is closed) to the back surface of the liquid-impermeable sheet 11. This fixing can be performed with a hot melt adhesive HM as in the illustrated example, or by welding the materials.

[0095] The side flaps 70 may be omitted.

[0096] (exterior body) As shown in the figure, the outer coverings 12F, 12B consist of a rectangular front outer covering 12F that forms at least the waistline of the front body F, and a rectangular back outer covering 12B that forms at least the waistline of the back body B. The front outer covering 12F and the rear outer covering 12B may not be continuous at the crotch side and may be spaced apart in the front-to-back direction LD (two-piece outer covering type), or may be continuous from the front body to the back body (integrated outer covering type), as not shown. In the two-piece outer covering type, the front-to-back distance 12d may be, for example, approximately 40 to 60% of the total length Y. In the figure, the lower edges of the front outer covering 12F and the rear outer covering 12B are linear along the width direction WD, but the lower edge of at least one of the front outer covering 12F and the rear outer covering 12B may be curved to fit around the legs.

[0097] In a two-piece outer-casing pants-type disposable diaper, the inner body 200 is exposed between the front outer body 12F and the rear outer body 12B. Therefore, to prevent the liquid-impermeable sheet 11 from being exposed on the back surface of the inner body 200, a cover nonwoven fabric 13 is preferably provided on the back surface of the inner body 200, extending from between the front outer body 12F and the inner body 200 to between the rear outer body 12B and the inner body 200. The inner and outer surfaces of the cover nonwoven fabric 13 can be bonded to their respective opposing surfaces with a hot-melt adhesive. The nonwoven fabric used for the cover nonwoven fabric 13 can be selected appropriately from a material similar to that of the outer bodies 12F and 12B. Although not shown, the outer body may be continuous from the front body F to the back body B, passing through the crotch area. In this case, the outer body will have not only a portion corresponding to the waist region T but also a portion corresponding to the middle region L.

[0098] The front exterior body 12F and the rear exterior body 12B have a front waist portion and a rear waist portion that form the waist region T. In the example shown in Figures 1 and 2, the front exterior body 12F and the rear exterior body 12B have the same dimensions in the front-to-rear direction LD, and the front exterior body 12F and the rear exterior body 12B do not have a portion corresponding to the middle region L, but as shown in Figure 7, the rear exterior body 12B may have a longer dimension in the front-to-rear direction than the front exterior body 12F, and the front exterior body 12F does not have a portion corresponding to the middle region L, but the rear exterior body 12B may have a buttocks cover portion C extending from the waist region T toward the middle region L. Although not shown, the front exterior body 12F may also be provided with a groin cover portion extending from the waist region T toward the middle region L.

[0099] As shown in Figures 4 and 5, the exterior bodies 12F, 12B are formed by joining an outer sheet layer and an inner sheet layer adjacent to the outer and inner sides of the elastic members 16-19 (described later) using a joining method such as a hot melt adhesive or welding. The outer sheet layer and the inner sheet layer can be formed from two sheets 12S, 12H as shown in the illustrated example, or from a single sheet material. For example, in the latter case, the inner sheet layer and the outer sheet layer are respectively formed by the inner and outer portions of a single sheet material folded back at the edge of the waist opening WO (which may be the edge on the crotch side) in part or all of the exterior bodies 12F, 12B. The illustrated example shows the former case, in which the sheet material 12S forming the outer sheet layer in the lower waist portion is folded back around the waist opening WO side of the sheet material 12H forming the inner sheet layer in the lower waist portion and folded back inward, with this folded back portion 12r extending to cover the edge of the interior body 200 on the waist opening WO side. On the other hand, in the waist portion, the folded portion 12r serves as an inner sheet layer adjacent to the inside of the elastic member.

[0100] The exterior bodies 12F, 12B incorporate elastic members 16-19 to improve the fit around the wearer's waist, and form a stretchable region A2 that stretches elastically in the width direction WD in response to the stretching of the elastic members 16-19. In this stretchable region A2, the exterior bodies 12F, 12B contract in their natural length state as the elastic members contract, forming wrinkles or creases. When stretched in the longitudinal direction of the elastic members, they can be stretched to a predetermined stretch rate without wrinkles. The elastic members 16-19 can be elongated elastic members such as rubber threads (illustrated example), as well as known elastic members in strip, net, film, and other shapes, without any particular limitation. The elastic members 16-19 may be made of synthetic or natural rubber.

[0101] To explain the elastic members 16-19 in the illustrated example in more detail, a plurality of waist elastic members 17 are attached to the waist portion W of the outer bodies 12F, 12B at intervals in the front-to-rear direction so as to be continuous over the entire width direction WD. Of the waist elastic members 17, one or more arranged in the region adjacent to the lower waist portion U may overlap the inner body 200, or may be provided on both sides in the width direction except for the central portion in the width direction that overlaps with the inner body 200. The waist elastic members 17 should have a thickness of 155-1880 dtex, particularly about 470-1240 dtex (in the case of synthetic rubber; in the case of natural rubber, a cross-sectional area of ​​0.05-1.5 mm). 2 , especially 0.1 to 1.0 mm 2 It is preferable to provide about 2 to 15, and especially about 4 to 10, rubber threads of about 1 / 4" thick (approximately 1 / 4" thick) at intervals of 2 to 12 mm, especially 3 to 7 mm, and the resulting elongation rate in the width direction WD of the waist portion W is preferably about 150 to 400%, especially about 220 to 320%. Furthermore, it is not necessary for the waist portion W to use elastic members of the same thickness or to have the same elongation rate all along the front-to-back direction LD, and for example, the thickness or elongation rate may be different in some areas.

[0102] Additionally, a plurality of lower waist elastic members 16, 19 made of elongated elastic members are attached to the lower waist portion U of the exterior bodies 12F, 12B at intervals in the front-to-back direction to form a lower waist stretchable region (a region having lower waist elastic members 16, 19). The lower waist elastic members 16, 19 have a thickness of 155 to 1880 dtex, particularly about 470 to 1240 dtex (in the case of synthetic rubber, or a cross-sectional area of ​​0.05 to 1.5 mm in the case of natural rubber). 2 , especially 0.1 to 1.0 mm 2 It is preferable to provide about 5 to 30 elastic threads of about 100 mm thick (approximately 1 / 2" thick) at intervals of 1 to 15 mm, especially 3 to 8 mm, and the resulting elongation rate in the width direction WD of the waist lower portion U is preferably about 200 to 350%, especially about 240 to 300%. Furthermore, it is not necessary for the waist lower portion U to use elastic members of the same thickness or have the same elongation rate all over its front-to-back direction LD, and thicknesses and elongation rates may vary in some areas.

[0103] When elastic members 16, 19 are provided in the front-to-back range including the absorbent body 56, as in the lower waist portion U in the illustrated example, in order to prevent contraction of the absorbent body 56 in the width direction WD in part or all of the region, it is preferable to designate the widthwise middle portion, including part or all of the portion overlapping with the absorbent body 56, as a non-elasticated region A1, and designate both widthwise sides of this as elasticated regions A2 (in the illustrated example, these are lower-waist elasticated regions). The widthwise dimension of the elasticated regions A2 provided on both sides of the non-elasticated region A1 may be substantially constant in the front-to-back direction LD as in the illustrated example, or may vary in the front-to-back direction LD, although not shown. Furthermore, the widthwise dimension of the elasticated regions A2 provided on both sides of the non-elasticated region A1 in the width direction WD may be substantially the same in the front body portion F and the back body portion B, or may be different.

[0104] The stretchable region A2 and non-stretchable region A1 can be constructed by attaching elastic members 16-17, 19 between the inner and outer sheet layers, and then cutting the elastic members 16, 19 into small pieces by applying pressure and heat or cutting them at one location in the middle of the width of the region that will become the non-stretchable region A1, or across almost the entire region, leaving stretchability in the stretchable region A2 while eliminating stretchability in the non-stretchable region A1. Note that unnecessary elastic members 18 that do not substantially contribute to the formation of stretchability will remain in the non-stretchable region A1.

[0105] The sheet materials 12S, 12H forming the inner and outer sheet layers can be used without any particular limitation, but nonwoven fabric is preferred. When nonwoven fabric is used, the basis weight per sheet is 10 to 30 g / m 2 It is preferable to set it to about this level.

[0106] The elastic members 16-19 can be fixed to the exterior bodies 12F, 12B by known methods. The inner sheet layer and the outer sheet layer can also be joined to each other by known methods. For example, in the portions of the exterior bodies 12F, 12B having the elastic members 16-19, a hot melt adhesive HM can be applied only to the outer peripheral surfaces of the elastic members 16-19 using an application means such as a comb gun or a SureWrap nozzle, and the elastic members can then be sandwiched between the inner sheet layer and the outer sheet layer. The hot melt adhesive HM applied only to the outer peripheral surfaces of the elastic members 16-19 can then be used to fix the elastic members 16-19 to the inner sheet layer and the outer sheet layer, and the inner sheet layer and the outer sheet layer together.

[0107] (Interior body joint) The inner body 200 can be joined to the outer bodies 12F, 12B by a joining method that uses material welding, such as heat sealing or ultrasonic sealing, or by a hot melt adhesive. In the illustrated example, the inner body 200 is fixed to the inner surfaces of the outer bodies 12F, 12B via a hot melt adhesive that is applied to the back surface of the inner body 200, that is, in this case, the back surface of the liquid-impermeable sheet 11 and the base portions 65 of the rising gathers 60. The inner body joining portion 20 that joins the inner body 200 and the outer bodies 12F, 12B can be provided over almost the entire overlapping area, as shown in Figure 2, and can also be provided in a portion excluding both widthwise ends of the inner body 200, for example.

[0108] Because it is possible to prevent the superabsorbent polymer particles from escaping through the packaging nonwoven fabric 58 as described above, it is possible to omit components such as the top sheet 30 and intermediate sheet 40 that cover the surface of the absorbent element 50, as shown in Figures 17 and 18, thereby achieving significant cost reductions. In this case, as long as the middle portion of the surface of the absorbent element 50, excluding both end portions in the width direction WD, is not covered by other components over the entire front-to-back direction LD and the packaging nonwoven fabric 58 is exposed on the surface, only the middle portion in the width direction WD does not have to be covered by other components, as in the illustrated example, or the entire surface of the absorbent element 50 does not have to be covered by other components.

[0109] <Effectiveness verification test> As shown in Figures 17 and 18, pants-type disposable diaper samples 1 to 8 were produced, each having the same structure as that shown in Figures 1 to 6, except that the top sheet 30 and intermediate sheet 40 were omitted and the width of the joining region between the absorbent element 50 and the liquid-impermeable sheet 11 was increased. Other specifications were as shown in Table 1. Specifications other than those shown in Table 1 were common to all samples. For these samples 1 to 8, the surface of the intersection was lightly traced with a finger, and the presence or absence of a gritty feel from the superabsorbent polymer particles was evaluated on a two-point scale of ○ (not felt or only a few particles felt) or × (felt gritty). Furthermore, for these samples 1 to 8, a test to confirm the feel of superabsorbent polymer particles slipping out was conducted, as described below.

[0110] (Test to confirm the escape of superabsorbent polymer particles) Test apparatus 80 is shown in Figure 23. This test apparatus 80 was configured so that a collection tray 83 for receiving superabsorbent polymer was fixed on a shaking table 82b of a shaker 82 (MK161 manufactured by Yamato Scientific Co., Ltd.) installed on a horizontal surface 81, and a friction body 84 consisting of a metal cylinder (diameter 55 mm) was fixed upright in the center of the collection tray 83, so that the collection tray 83 and friction body 84 were shaken integrally with the shaking table 82b. The vertical distance d1 between the upper surface of the friction body 84 and the upper surface of the shaking table 82b was 72 mm. In addition, a pair of pedestals 85 were fixed upright on both sides of the shaker 82 in the lateral direction on the horizontal surface 81. A sample 86 was in an unfolded state (as shown in Figure 1), stretched between the pedestals 85 so that the surface of the sample 86 (the exposed surface of the packaging nonwoven fabric) faced downward, and fixed to the pedestals 85. At this time, the front-to-rear direction LD of the sample 86 was aligned with the long axis direction BD of the ellipse of the shaking method. Furthermore, without friction body 84 installed, the vertical distance d2 between the contact portion of the surface of sample 86 with the friction body and the upper surface of shaking table 82b was set to 71 mm so that the surface of sample 86 was in contact with friction body 84. Next, the shaking method of shaker 82 was set to elliptical (swing width w1 in the major axis direction: 30 mm, swing width w2 in the minor axis direction: 20 mm), and shaking was performed at a rotation speed of 90 rpm for 2 minutes. After rubbing friction body 84 against the surface of sample 86 while moving in an elliptical manner, as shown in Fig. 24, the number of superabsorbent polymer particles that fell onto collection tray 83 was counted.

[0111] The test results are shown in Table 1. Samples 1 and 5 had a gritty feel and some of the superabsorbent polymer particles came loose, whereas Samples 2, 3, 4, 6, 7 and 8 did not have a gritty feel and no superabsorbent polymer particles came loose, despite having continuous grid-like grooves.

[0112] [Table 1]

[0113] <Explanation of terms used in the specification> In the present specification, the following terms have the following meanings unless otherwise specified in the specification.

[0114] "Front-rear direction" refers to the direction indicated by the symbol LD in the drawing (longitudinal direction), and "width direction" refers to the direction indicated by the symbol WD in the drawing (left-right direction), with the front-rear direction and width direction being perpendicular to each other.

[0115] "Front side" means the side closest to the wearer's skin when worn, and "reverse side" means the side farthest from the wearer's skin when worn.

[0116] "Front" means the side closest to the wearer's skin when worn, and "back" means the side away from the wearer's skin when worn.

[0117] "Elongation rate" refers to the value when the natural length is 100%. For example, an elongation rate of 200% is equivalent to an elongation ratio of 2 times.

[0118] "Artificial urine" is a mixture of 2 wt% urea, 0.8 wt% sodium chloride, 0.03 wt% calcium chloride dihydrate, 0.08 wt% magnesium sulfate heptahydrate, and 97.09 wt% ion-exchanged water.

[0119] "Gel strength" is measured as follows: 1.0 g of superabsorbent polymer is added to 49.0 g of artificial urine and stirred with a stirrer. The resulting gel is left in a constant temperature and humidity chamber at 40°C and 60% RH for 3 hours, then returned to room temperature, and the gel strength is measured using a card meter (I.techno Engineering: Curdmeter-MAX ME-500).

[0120] The "average fiber diameter" is determined by observing the target layer with a microscope (optical microscope, SEM, etc.) at 1000x magnification, randomly selecting 30 constituent fibers, measuring their fiber diameters (μm), and calculating the average value.

[0121] "Basis weight" is measured as follows: After pre-drying the sample or test piece, leave it in a test room or device under standard conditions (test location: temperature 23±1°C, relative humidity 50±2%) until it reaches a constant weight. Pre-drying refers to bringing the sample or test piece to a constant weight in an environment at a temperature of 100°C. Note that pre-drying is not necessary for fibers with an official moisture regain of 0.0%. From the test piece that has reached a constant weight, use a sample collection template (100mm x 100mm) to cut out a sample measuring 100mm x 100mm. Measure the weight of the sample and multiply it by 100 to calculate the weight per square meter, which is the basis weight.

[0122] The "thickness" of thick members such as the absorber 56, the absorbent element 50, and the bottom 51 of the groove 53 is measured using a thickness measuring device (Peacock, Dial Thickness Gauge, Model JB (measurement range 0 to 35 mm, measurement area 20 mm diameter circular terminal, measurement force approximately 3.0 N, pressure approximately 30 KPa)) manufactured by Ozaki Manufacturing Co., Ltd., with the sample and the thickness measuring device held horizontally.

[0123] The "thickness" of thin sheets such as nonwoven fabrics was measured using an automatic thickness measuring device (KES-G5 handy compression measurement program) with a load of 0.098 N / cm 2 , and pressure area: 2cm 2 The measurement is automatically performed under the following conditions: The "thickness" of the packaged nonwoven fabric refers to the thickness of the portion where the thickness 50t of the absorbent element 50 is at its maximum.

[0124] The "layer thickness" of the nonwoven fabric is determined by observing the cross section of the target layer at the point where the thickness 50t of the absorption element 50 is at its maximum using a microscope (optical microscope, SEM, etc.) at 1000x magnification, measuring the apparent thickness at five randomly selected measurement points, and calculating the average value.

[0125] "Area ratio" means the ratio of the area of ​​the target portion per unit area, and is expressed as a percentage by dividing the total area of ​​the target portion (e.g., the bottom 51 of the groove 53) in the entire target area (e.g., the back surface of the absorbent element 50) by the area of ​​the target area.

[0126] The water absorption capacity is measured according to JIS K7223-1996 "Test method for water absorption capacity of superabsorbent resins."

[0127] The water absorption rate is the "time to the end point" when 2g of superabsorbent polymer and 50g of physiological saline are used and tested according to JIS K7224-1996 "Test method for water absorption rate of superabsorbent polymers."

[0128] "Deployed state" means a flat, deployed state without contraction (including any contraction, such as contraction due to elastic members) or slack.

[0129] Unless otherwise specified, the dimensions of each part refer to the dimensions in the unfolded state, not in the natural length state.

[0130] If no environmental conditions are specified for a test or measurement, the test or measurement shall be carried out in a test room or device under standard conditions (temperature 23±1°C, relative humidity 50±2%). [Industrial Applicability]

[0131] The present invention can be used for disposable diapers such as pants-type disposable diapers, tape-type disposable diapers, and pad-type disposable diapers, as well as absorbent articles in general, such as sanitary napkins. [Explanation of symbols]

[0132] 11...liquid-impermeable sheet, 12A...side seal, 12B...rear outer body, 12E...waist extension portion, 12F, 12B...outer body, 12F...front outer body, 12S, 12H...sheet material, 13...cover nonwoven fabric, 16, 19...waist lower elastic member, 17...waist elastic member, 18...unnecessary elastic member, 200...inner body, 201...inner body joint portion, 21...intersection portion, 22...non-intersection portion, 30...top sheet, 40...intermediate sheet, 50...absorbent element, 51...bottom, 51f...unit frame, 52...non-compressed portion, 53...groove, 56...absorbent body, 56L...low basis weight portion, 56c...covering layer, 57...backflow prevention layer, 58...packaging nonwoven fabric, 60...rising gathers, 60A...tip side portion, 60B...base side portion, 62...gathered sheet, 63...gathered elastic member, 67...folded portion, 68...raised portion, 70...side flap, 71...first sheet layer, 72...second sheet layer, 73...side elastic member, 90...anvil roll, 91...projection portion, 92...smooth roll, A1...non-stretchable region, A2...stretchable region, B...back body, C...buttocks covering portion, F...front body, HM...hot melt adhesive, HM1...first hot melt adhesive, HM2...second hot melt adhesive, L...middle region, LD...front and rear direction, LO...leg opening, M...crotch region, SG...side stretchable region, T...torso region, U...lower waist portion, W...waist portion, WD...width direction, WO...waist opening, t1...first thickness, t2...second thickness.

Claims

1. The garment has a crotch portion and a front portion and a rear portion extending forward and rearward from the crotch portion, respectively; an absorbent element including an absorbent body provided at a position including the crotch area and a wrapping nonwoven fabric wrapping the absorbent body; The absorbent body has a layer formed by mixing and accumulating pulp fibers and superabsorbent polymer particles, The absorbent element has a lattice-like continuous groove that is recessed from the surface of the absorbent element to the absorbent body and has a bottom that is compressed in the thickness direction, and The groove has an intersection portion and a non-intersection portion located between adjacent intersection portions, and the thickness of the bottom portion increases stepwise or continuously from the center of the non-intersection portion in the longitudinal direction toward the intersection portion in at least a partial region of the surface of the absorbent element. An absorbent article characterized by:

2. The basis weight of the pulp fibers in the absorbent body is 100 to 450 g / m ２ and the weight ratio of pulp fibers to superabsorbent polymer particles in the absorbent body is 30:70 to 70:30; The maximum thickness of the absorbent element is 4 to 35 mm, the thickness of the bottom portion at the center in the longitudinal direction of the non-intersecting portion is 15 to 35% of the maximum thickness of the absorbent element; The thickness of the bottom portion at the intersection portion is 1.4 to 6 times the thickness of the bottom portion at the center in the longitudinal direction of the non-intersection portion. The absorbent article of claim 1.

3. The width of the bottom is 1 to 3 mm, The grooves are formed in a diagonal lattice pattern, each of which has a first portion inclined by 40 to 50 degrees clockwise relative to the front-rear direction in a plan view and a second portion inclined by 40 to 50 degrees counterclockwise relative to the front-rear direction in a plan view. The absorbent article according to claim 1 or 2.

4. The packaging nonwoven fabric has one or more meltblown layers and one or more protective layers, The basis weight of the packaging nonwoven fabric is 10 to 17 g / m ２ and The constituent fibers of the protective layer have an average fiber diameter of 10 to 25 μm, The constituent fibers of the meltblown layer are fibers having an average fiber diameter of 5 μm or less, The air permeability measured in accordance with JIS L 1096:2010 using Method A (Fragile method) in a state where five sheets of the packaging nonwoven fabric are stacked is 25.5 to 70.0 cm ３ / cm ２ s, The packaging nonwoven fabric has a standard elongation rate in the front-to-rear direction specified in JIS L 1913:2010 of 20 to 100%, The standard elongation in the width direction as specified in JIS L 1913:2010 is 20 to 110%. The absorbent article according to claim 1 or 2.

5. The basis weight of the packaging nonwoven fabric is 15 to 17 g / m ２ That is, The absorbent article according to claim 4.

6. The absorbent body has a covering layer that covers the surface of the absorbent body and is made up of an accumulation of only pulp fibers. The absorbent article according to claim 1 or 2.

7. the packaged nonwoven fabric has a back surface portion located on the back side of the absorbent body, a first front surface portion that continues from the back surface portion, wraps around one side edge of the absorbent body to reach the front side of the absorbent body, and a second front surface portion that continues from the back surface portion, wraps around the other side edge of the absorbent body to reach the front side of the absorbent body; the first front-side portion and the second front-side portion have stacked portions that overlap each other, All the grooves are formed in the laminated portion. The absorbent article according to claim 1 or 2.

8. The absorbent element has a middle portion, excluding both widthwise ends, that is not covered by other members over the entire front-rear direction, and the packaging nonwoven fabric is exposed on the surface of the absorbent article. The absorbent article according to claim 5.

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