absorbent articles

Abstract

To provide an absorbent article in which a top sheet can be made to have a glossy appearance like silk when viewed from the skin side. The absorbent article (1) has a front-to-back direction (y) and a width direction (x), and comprises a top sheet (2), a back sheet (3), and an absorbent body (4) disposed therebetween. The top sheet (2) is made of a nonwoven fabric, and the difference in tensile strength between the front-to-back direction (y) and the width direction (x) is 5.0 N or more. When the top sheet (2) is measured from the skin-facing side with a colorimeter, the L * a * b * Lightness according to the color system (L * ) is 60 or more, saturation (C * ) is 5 or less, and the brightness difference between the front-to-back direction y and the width direction x (ΔL * ) is 1.0 or more, and the saturation difference between the front-to-back direction y and the width direction x (ΔC * ) is 0.6 or more, and the sum of the difference in lightness and saturation (ΔL * +ΔC * ) is 2.0 or greater.

Description

[Technical Field]

[0001] The present disclosure relates to absorbent articles such as incontinence pads (including light incontinence pads), sanitary napkins, disposable diapers, and the like. [Background technology]

[0002] Various absorbent articles with improved appearance have been known. For example, Patent Document 1 discloses an absorbent article having an absorbent body with an absorbent layer and a top sheet placed on the skin-facing side of the absorbent body, the top sheet having a whiteness of 80% or more, and a dark-colored sheet having a whiteness of 35% or less placed between the absorbent body and the top sheet. Patent Document 2 discloses an absorbent article having an exterior sheet with an exterior surface, the absorbent article containing pearl powder or a pearl-derived component, the exterior sheet being made of a nonwoven fabric, and the exterior surface having a glossiness of 5 or more. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2014-226215 [Patent Document 2] Japanese Patent Publication No. 2022-12539 Summary of the Invention [Problem to be solved by the invention]

[0004] As described above, various absorbent articles with improved appearance have been proposed. An object of the present disclosure is to provide an absorbent article in which the top sheet can have a silky glossy appearance when viewed from the skin-facing side. [Means for solving the problem]

[0005] The absorbent article according to the present disclosure that can solve the above problems is as follows. [1] An absorbent article having a front-to-back direction and a width direction, a top sheet, a back sheet, and an absorbent disposed therebetween, wherein the top sheet is made of a nonwoven fabric, the difference in tensile strength between the front-to-back direction and the width direction is 5.0 N or more, and the L * a * b * Lightness according to the color system (L * ) is 60 or more, saturation (C * ) is 5 or less, and the brightness difference between the front and back direction and the width direction (ΔL * ) is 1.0 or more, and the saturation difference between the front-to-back direction and the width direction (ΔC * ) is 0.6 or more, and the sum of the brightness difference and the saturation difference (ΔL * +ΔC * ) is 2.0 or more. [2] The absorbent article according to [1], wherein the nonwoven fabric is a spunlace nonwoven fabric containing rayon fibers. [3] The absorbent article according to [2], wherein the spunlace nonwoven fabric contains polyolefin fibers or polyester fibers together with rayon fibers, and the content of the rayon fibers is 10% by mass or more and 70% by mass or less. [4] The absorbent article according to [2] or [3], wherein the spunlace nonwoven fabric is formed into a web by a carding method. [5] The absorbent article according to any one of [2] to [4], wherein the spunlace nonwoven fabric is calendered. [6] The absorbent article according to any one of [2] to [5], wherein the fineness of the constituent fibers of the spunlace nonwoven fabric is 0.5 dtex or more and 3.5 dtex or less. [7] An absorbent article according to any one of [1] to [6], wherein the absorbent body has a plurality of layers of sheet members, an absorbent resin is disposed between the sheet members, and no pulp fibers are disposed between the sheet members, the absorbent body has sealed portions where the sheet members are joined together, and non-sealed portions where the sheet members are not joined together, the absorbent resin is disposed in the non-sealed portions, and the non-sealed portions are arranged in stripes extending in the front-to-rear direction. [8] An absorbent article according to any one of [1] to [7], wherein side sheets are provided on both sides of the top sheet in the width direction, the side sheets are joined to the top sheet at side joining portions provided on the skin-facing side of the top sheet, and the side sheets are provided with elastic members extending in the front-to-rear direction to form rising flaps. [Effects of the Invention]

[0006] In the absorbent article of the present disclosure, the top sheet can have a silky glossy appearance when viewed from the skin-facing side, thereby providing an absorbent article with a luxurious appearance. [Brief explanation of the drawings]

[0007] [Figure 1] 1 shows a plan view of a light incontinence pad as an example of an absorbent article according to an embodiment of the present disclosure, viewed from the top sheet side. [Figure 2] 2 shows a cross-sectional view of the absorbent article shown in FIG. 1 taken along line II-II. [Figure 3] 2 shows an example of an absorbent body provided in the absorbent article shown in FIG. 1, and is a cross-sectional view of the absorbent body in the width direction. [Figure 4] 4 shows a partially cutaway plan view of the absorbent body shown in FIG. 3, viewed from the top sheet side. DETAILED DESCRIPTION OF THE INVENTION

[0008] An absorbent article according to an embodiment of the present disclosure will be described with reference to the drawings. Figures 1 and 2 show an example of the structure of a light incontinence pad as an example of an absorbent article according to the present disclosure. Figure 1 shows a plan view of the absorbent article (light incontinence pad) as seen from the top sheet side, and Figure 2 shows a cross-sectional view of the absorbent article shown in Figure 1 taken along line II-II. Note that the absorbent article according to the present disclosure is not limited to the embodiment shown in the drawings.

[0009] The absorbent article 1 has a top sheet 2, a back sheet 3, and an absorbent body 4 disposed between them. The top sheet 2 is disposed on the skin-facing side of the absorbent body 4, and the back sheet 3 is disposed on the non-skin-facing side of the absorbent body 4. Excrement that passes through the top sheet 2 is contained by the absorbent body 4. The back sheet 3 prevents the excrement from leaking out. The absorbent article 1 can be used, for example, incontinence pads (including light incontinence pads), sanitary napkins, disposable diapers, etc., and is particularly suitable for use in light incontinence pads and sanitary napkins.

[0010] The absorbent article 1 has a front-to-back direction y and a width direction x. The front-to-back direction y indicates the longitudinal direction of the absorbent article 1. The front-to-back direction y corresponds to the direction extending in the front-to-back direction between the wearer's crotch when the absorbent article 1 is worn by the wearer. The width direction x indicates a direction on the same plane as the absorbent article 1 and perpendicular to the front-to-back direction y. The width direction x corresponds to the left-to-right direction of the wearer when the absorbent article 1 is worn by the wearer. The direction perpendicular to the plane formed by the front-to-back direction y and the width direction x is defined as the thickness direction z. The absorbent article 1 has a skin-facing side and a non-skin-facing side defined with respect to the thickness direction z.

[0011] The top sheet 2 is provided so as to face the wearer's skin when the absorbent article 1 is worn. The top sheet 2 is preferably liquid permeable. The top sheet 2 is made of a nonwoven fabric, and can be, for example, a nonwoven fabric made from hydrophilic fibers such as cellulose, rayon, cotton, etc.; or a nonwoven fabric made from hydrophobic fibers such as polyolefin (e.g., polypropylene, polyethylene), polyester (e.g., PET), polyamide (e.g., nylon), in which the surfaces of the hydrophobic fibers have been made hydrophilic with a surfactant.

[0012] The back sheet 3 is preferably liquid-impermeable. The back sheet 3 may be a nonwoven fabric made of hydrophobic fibers such as polyolefin (e.g., polypropylene, polyethylene), polyester (e.g., PET), polyamide (e.g., nylon), or a plastic film. Alternatively, the back sheet 3 may be a laminate of a nonwoven fabric and a plastic film.

[0013] The top sheet 2 and the back sheet 3 are preferably formed to be longer in the front-to-rear direction y than the absorbent body 4. Specifically, the top sheet 2 and the back sheet 3 are preferably provided so as to extend forward of the front edge of the absorbent body 4 and rearward of the rear edge thereof.

[0014] The absorbent article 1 may have a backing sheet 5 provided between the absorbent body 4 and the back sheet 3. By providing the backing sheet 5, the shape retention of the absorbent article 1 can be improved.

[0015] The absorbent article 1 preferably has rise flaps 6 on both sides of the skin-facing side in the width direction x. The rise flaps 6 prevent side leakage of urine and the like. The rise flaps 6 can be formed by providing side sheets 7 on both sides of the top sheet 2 in the width direction x, joining the side sheets 7 to the top sheet 2 at side joints 71 on the skin-facing side of the top sheet 2, and providing the side sheets 7 with standing elastic members 8 extending in the front-to-back direction y. The side sheets 7 are preferably formed so that the inner portions of the side sheets 7 in the width direction x relative to the side joints 71 are able to stand up, and the standing elastic members 8 are preferably provided in the parts of the side sheets 7 that are able to stand up. By providing the side sheets 7 and the standing elastic members 8 in this manner, the contractile force of the standing elastic members 8 causes the inner portions of the side sheets 7 in the width direction x to rise toward the wearer's skin, forming the rise flaps 6. The rise flaps 6 or the side sheets 7 are preferably selected from a liquid-impermeable plastic film, a liquid-impermeable nonwoven fabric, or a combination thereof.

[0016] The nonwoven fabrics used for the above-described sheets include spunbond nonwoven fabrics, point-bond nonwoven fabrics, air-through nonwoven fabrics, melt-blown nonwoven fabrics, air-laid nonwoven fabrics, spunlace nonwoven fabrics, and SMS nonwoven fabrics. The mass per unit area of ​​each of these sheets is 8 g / m. 2 or more than 10g / m 2 It may be more than 60 g / m 2 or less than 50g / m 2It may be the following:

[0017] The absorbent body 4 is not particularly limited as long as it contains an absorbent material capable of absorbing urine and other excrement. For example, the absorbent body 4 may be a molded body obtained by molding an absorbent material into a predetermined shape, or a molded body covered with a covering sheet such as a paper sheet (e.g., tissue paper or thin paper) or a liquid-permeable nonwoven fabric sheet. Examples of absorbent materials include hydrophilic fibers such as pulp fibers, and water-absorbent resins such as polyacrylic acid, polyaspartic acid, cellulose, and starch-acrylonitrile. Furthermore, the water-absorbent material may include heat-fusible fibers such as polyolefin fibers such as polyethylene and polypropylene, polyester fibers such as PET, and polyamide fibers. These heat-fusible fibers may be hydrophilized with a surfactant or the like to enhance their affinity for urine and other wastes.

[0018] The absorbent material preferably contains hydrophilic fibers to increase the absorption rate of urine and the like. Furthermore, the absorbent material preferably contains a water-absorbent resin to increase the absorption capacity. The absorbent body 4 may contain hydrophilic fibers (particularly pulp fibers) and a water-absorbent resin as the absorbent material. In this case, it is preferable to use, for example, an aggregate of hydrophilic fibers to which the water-absorbent resin is mixed or dispersed.

[0019] The absorbent body 4 may be a sheet-like absorbent body. An example of a sheet-like absorbent body is one that has a water-absorbent resin between the sheet members but does not have pulp fibers. Such a sheet-like absorbent body can achieve a high absorption capacity because it has a water-absorbent resin between the sheet members. Furthermore, because the sheet-like absorbent body does not have pulp fibers between the sheet members, it can be formed thin and not bulky.

[0020] The absorbent body 4 may have multiple absorbent layers. The absorbent body 4 may have multiple sheet-like absorbent bodies. For example, the absorbent body 4 may have a first absorbent layer on the top sheet 2 side and a second absorbent layer on the back sheet 3 side. The number of absorbent layers included in the absorbent body 4 may be determined appropriately depending on the application, and the absorbent body 4 may have three or more absorbent layers. In particular, an absorbent body 4 having multiple sheet-like absorbent bodies can have a higher water absorption capacity while maintaining a thin profile.

[0021] There are no particular limitations on the shape (planar shape) of the absorbent body 4. The shape of the absorbent body 4 may be appropriately determined depending on the application, and examples include a substantially rectangular, hourglass, gourd, battledore, etc. When the absorbent body 4 has multiple absorbent layers, the shapes (planar shapes) and / or sizes of the absorbent layers may be different from one another.

[0022] The top sheet 2 is made of a nonwoven fabric, and the difference in tensile strength between the front-to-back direction y and the width direction x is 5.0 N or more. When the top sheet 2 is measured from the skin-facing side with a colorimeter, the L * a * b * Lightness according to the color system (L * ) is 60 or more, saturation (C * ) is 5 or less, and the brightness difference between the front-to-back direction y and the width direction x (ΔL * ) is 1.0 or more, and the saturation difference between the front-to-back direction y and the width direction x (ΔC * ) is 0.6 or more, and the sum of the difference in lightness and saturation (ΔL * +ΔC * ) is 2.0 or more. By using such a top sheet 2, the top sheet 2 can have a silky, glossy appearance when the absorbent article 1 is viewed from the skin-facing side. This allows the absorbent article 1 to have a luxurious appearance.

[0023] The inventors investigated various nonwoven fabrics to determine which characteristics of the nonwoven fabric affect its silk-like, glossy appearance. The results are shown in Table 1. In Table 1, the tensile strength difference was measured using a tensile tester. The MD direction of the nonwoven fabric corresponds to the front-to-back direction of the top sheet 2, and the CD direction of the nonwoven fabric corresponds to the width direction of the top sheet 2. The tensile strengths of the nonwoven fabric in both the MD and CD directions were measured, and the difference was calculated. The lightness and saturation shown in Table 1 were determined by measuring the top sheet 2 from the skin-facing side of the absorbent article 1 using a Konica Minolta FD-7 fluorescence spectrodensitometer (illumination: Illuminant A, observation illuminant: D65) as a colorimeter. Appearance evaluation was performed by having 11 evaluators rank six types of nonwoven fabrics A to F in order of silk-like appearance and calculating the average. The lower the appearance evaluation value, the more silk-like the appearance was evaluated. The results revealed that nonwoven fabrics A to C, possessing the above characteristics, exhibited a more silk-like, glossy appearance.

[0024] [Table 1]

[0025] The difference in tensile strength is an index of the orientation of the constituent fibers of the nonwoven fabric of the top sheet 2, and a larger difference in tensile strength indicates a tendency for the constituent fibers of the nonwoven fabric to be oriented in one direction. Therefore, the greater the difference in tensile strength between the front-to-back direction y and the width direction x, the more directional the luster of the top sheet 2 will be. The difference in tensile strength between the front-to-back direction y and the width direction x of the top sheet 2 is 5.0 N or more, and may be 6.0 N or more, 7.5 N or more, or 8.0 N or more. There are no particular upper limits to the difference in tensile strength between the front-to-back direction y and the width direction x of the top sheet 2, and may be, for example, 30.0 N or less, 25.0 N or less, or 20.0 N or less.

[0026] The top sheet 2 preferably has a greater tensile strength in the front-to-back direction y than in the width direction x, which makes the top sheet 2 more likely to exhibit a gloss that extends in the front-to-back direction y, and makes the top sheet 2 more likely to have a silky appearance when the absorbent article 1 is viewed from the skin-facing side.

[0027] Lightness (L * ) and saturation (C * ) is L * a * b * The color is determined based on a color system. When the lightness of the top sheet 2 measured from the skin-facing side is 60 or more and the chroma is 5 or less, the top sheet 2 has little color and exhibits a white or near-white color.

[0028] The brightness value of the top sheet 2 needs to be 60 or greater when measured either in the front-to-back direction y or in the width direction x, and it is preferable that the brightness values ​​of the top sheet 2 are 60 or greater when measured both in the front-to-back direction y and in the width direction x. The brightness value may be 63 or greater, 65 or greater, 68 or greater, or 70 or greater. There is no particular upper limit to the brightness value, and it may be, for example, 95 or less, 90 or less, 85 or less, or 80 or less.

[0029] The saturation value of the top sheet 2 may be 5 or less when measured from either the front-to-back direction y or the width direction x, and it is preferable that the saturation value of the top sheet 2 is 5 or less when measured from both the front-to-back direction y and the width direction x. The saturation value may be 4 or less or 3 or less. There is no particular restriction on the lower limit of the saturation value, and it may be, for example, 1 or more. The saturation is determined by the L * a * b * Color space a * and b * From the value of C, it can be calculated using the following formula: * =[(a * ) 2 +(b * ) 2 ] 1 / 2 .

[0030] The top sheet 2 has a lightness difference (ΔL * ) is 1.0 or more, and the saturation difference between the front-to-back direction y and the width direction x (ΔC * ) is 0.6 or more, and the sum of the difference in lightness and saturation (ΔL * +ΔC *) is 2.0 or more. This results in a difference in the appearance of the white color of the top sheet 2 when viewed from the front-to-back direction y and when viewed from the width direction x, and the top sheet 2 exhibits directional gloss.

[0031] The difference in lightness between the front-to-back direction y and the width direction x may be 1.3 or more, 1.7 or more, or 2.0 or more. There are no particular upper limits to the difference in lightness between the front-to-back direction y and the width direction x, and it may be, for example, 5.0 or less, 4.5 or less, 4.0 or less, or 3.5 or less. Since this makes it easier for the top sheet 2 to exhibit gloss extending in the front-to-back direction y, it is preferable that the lightness of the top sheet 2 in the width direction x be greater than the lightness in the front-to-back direction y.

[0032] The difference in saturation between the front-to-back direction y and the width direction x may be 0.8 or more. There is no particular upper limit to the difference in saturation between the front-to-back direction y and the width direction x, and it may be, for example, 3.0 or less, 2.5 or less, 2.0 or less, or 1.5 or less. Since this makes it easier for the top sheet 2 to exhibit gloss that extends in the front-to-back direction y, it is preferable that the saturation of the top sheet 2 in the front-to-back direction y be greater than the saturation in the width direction x.

[0033] The sum of the difference in lightness and saturation between the front-rear direction y and the width direction x may be 2.2 or more, 2.4 or more, or 2.6 or more. The upper limit of the sum of the difference in lightness and saturation between the front-rear direction y and the width direction x is not particularly limited, and may be, for example, 7.0 or less, 6.0 or less, 5.0 or less, or 4.0 or less.

[0034] In order to accentuate the silk-like luster of the top sheet 2, it is preferable that the side sheets 7 are configured to exhibit less silk-like luster than the top sheet 2. For example, the side sheets 7 may be made of a material other than a nonwoven fabric, or may be made of a material having a tensile strength difference between the front-to-rear direction y and the width direction x of less than 5.0 N and a brightness difference between the front-to-rear direction y and the width direction x (ΔL * ) is less than 1.0, and the saturation difference between the front-to-back direction y and the width direction x (ΔC * ) is less than 0.6, or the sum of the lightness difference and saturation difference (ΔL * +ΔC * ) may be configured to be less than 2.0.

[0035] The nonwoven fabric constituting the top sheet 2 is preferably a spunlace nonwoven fabric. Spunlace nonwoven fabrics are produced using a hydroentanglement method in which high-pressure water is sprayed onto a fiber web to entangle the fibers. By entangling the fibers without using adhesives or heat, the texture and luster of the fibers themselves can be imparted to the surface of the nonwoven fabric. In other words, because the fiber surface is not covered with adhesive or deformed by heat, the texture and luster of the fiber surface appear on the surface of the nonwoven fabric. Furthermore, spunlace nonwoven fabrics can form a fiber structure that has a random surface but has little apparent unevenness and little unevenness, thereby exhibiting smooth and uniform light reflection and making it easier to impart a silk-like natural texture and reflectivity to the surface of the top sheet 2.

[0036] Spunlace nonwoven fabrics are preferably formed into a web by the carding method. This facilitates orientation of the constituent fibers of the spunlace nonwoven fabric, making it easier for the top sheet 2 to exhibit directional gloss. It also makes it easier to impart a difference in tensile strength between the front-to-back direction y and the width direction x to the top sheet 2.

[0037] The surface of the spunlace nonwoven fabric is preferably calendered. This makes the spunlace nonwoven fabric more likely to have a densely packed fiber structure, which in turn makes light interference more likely to occur on the surface of the nonwoven fabric and increases gloss. The calendering is preferably flat calendering, i.e., the calendering is preferably performed by sandwiching the spunlace nonwoven fabric between flat rolls. This makes light reflection on the surface of the nonwoven fabric uniform and continuous, making it easier for the top sheet 2 to exhibit a silky smooth gloss.

[0038] The spunlace nonwoven fabric preferably contains rayon fibers. Rayon has a smooth fiber surface that reflects light well, so if the spunlace nonwoven fabric contains rayon fibers, the top sheet 2 tends to exhibit greater gloss.

[0039] Spunlace nonwoven fabrics preferably contain polyolefin or polyester fibers in addition to rayon fibers. When rayon fibers become wet, they swell, causing diffuse reflection of light at the fiber surface and making the orientation of the fibers constituting the nonwoven fabric more likely to collapse. However, if the spunlace nonwoven fabric contains polyolefin or polyester fibers in addition to rayon fibers, the polyolefin or polyester fibers support the structure between the fibers, preventing the loss of silk-like luster even when wet.

[0040] The rayon fiber content of the spunlace nonwoven fabric can be, for example, 10% by mass or more and 70% by mass or less. This makes it easy to impart a balanced silk-like luster to the spunlace nonwoven fabric both in the dry and wet states. The rayon fiber content of the spunlace nonwoven fabric can be 15% by mass or more, and 60% by mass or less, or 50% by mass or less.

[0041] The fineness of the constituent fibers of the spunlace nonwoven fabric is preferably 0.5 dtex or more and 3.5 dtex or less. This makes it easy to impart a silk-like luster to the spunlace nonwoven fabric. The fineness of the constituent fibers of the spunlace nonwoven fabric may be 1.0 dtex or more, or 3.0 dtex or less, or 2.5 dtex or less.

[0042] The nonwoven fabric constituting the top sheet 2, particularly the spunlace nonwoven fabric, has a basis weight of 25 g / m 2 More than 60g / m 2 The weight per unit area is preferably 28 g / m or less. 2 or more than 30g / m 2 It may be more than 55 g / m 2 or less than 50g / m 2 This allows the top sheet 2 to have a thickness close to that of silk fabric, and the top sheet 2 has a certain amount of basis weight, which makes it easier for light interference to occur and makes it more likely to exhibit luster.

[0043] The top sheet 2 formed as described above tends to have a silk-like appearance when the absorbent body 4 is a sheet-like absorbent body. When the absorbent body 4 is a sheet-like absorbent body, the skin-facing side of the absorbent body 4 tends to be formed flat overall rather than bulging, and as a result, the top sheet 2 tends to have a silk-like appearance when the absorbent article 1 is viewed from the skin-facing side. In particular, as shown in Figures 3 and 4, if the absorbent body 4 has a plurality of sheet members 41, a water-absorbent resin 42 is disposed between the sheet members 41, no pulp fibers are disposed, sealed portions 44 where the sheet members 41 are joined together and non-sealed portions 45 where the sheet members 41 are not joined together are arranged in stripes extending in the front-to-back direction y, and the water-absorbent resin 42 is disposed in the non-sealed portions 45, the sealed portions 44 and non-sealed portions 45 arranged in stripes form ridges extending in the front-to-back direction y on the skin-facing side of the absorbent body 4, and this tends to make the top sheet 2 exhibit a glossy appearance extending in the front-to-back direction y.

[0044] The configuration of the absorbent body 4 shown in Figures 3 and 4 will be described in detail. Figure 3 shows a cross-sectional view of the absorbent body 4, which is a sheet-like absorbent body, in the width direction x, and Figure 4 shows a partially cutaway plan view of the absorbent body 4, which is a sheet-like absorbent body, as viewed from the top sheet 2 side.

[0045] The absorbent body 4 has multiple layers of sheet members 41, with absorbent resin 42 disposed between the sheet members 41 and no pulp fibers. That is, the absorbent body 4 has sheet members 41 disposed on both the skin-facing side and the non-skin-facing side, with absorbent resin 42 disposed between these sheet members 41, but no pulp fibers disposed between these sheet members 41. Note that the presence of pulp fibers unavoidably mixed in during manufacturing is permitted between the sheet members 41. The above structure allows the absorbent body 4 to be formed thin while having a high absorption capacity.

[0046] There are no particular limitations on the shape (planar shape) of the absorbent body 4. Examples of the shape of the absorbent body 4 include a substantially rectangular shape, an hourglass shape, a gourd shape, and a battledore shape.

[0047] Examples of the water-absorbing resin 42 that can be used include polyacrylic acid-based water-absorbing resins such as sodium polyacrylate, starch-acrylonitrile graft copolymers, starch-acrylic acid graft copolymers, and starch-acrylamide graft copolymers, and polyvinyl alcohol-based water-absorbing resins such as crosslinked polyvinyl alcohol. It is preferable to use a polyacrylic acid-based water-absorbing resin such as sodium polyacrylate as the water-absorbing resin 42 because it has a high liquid absorption capacity.

[0048] The sheet member 41 is liquid permeable and may be, for example, a nonwoven fabric made of hydrophilic fibers such as cellulose, rayon, or cotton, or a nonwoven fabric made of hydrophobic fibers such as polyolefin (e.g., polypropylene or polyethylene), polyester (e.g., PET), or polyamide (e.g., nylon), in which the surface of the hydrophobic fibers has been made hydrophilic with a surfactant. Alternatively, the sheet member 41 may be made of woven fabric, knitted fabric, or perforated plastic film. Preferably, the sheet member 41 is made of a nonwoven fabric, i.e., a nonwoven fabric sheet.

[0049] The sheet member 41 may be provided separately as a sheet member on the skin side and a sheet member on the non-skin side, or one sheet member may be folded over, with one side being the skin side sheet member and the other side being the non-skin side sheet member.

[0050] The absorbent body 4 has sealed portions 44 where the sheet members 41 are joined together and non-sealed portions 45 where the sheet members 41 are not joined together, and a water-absorbent resin 42 is disposed in the non-sealed portions 45. The plurality of sealed portions 44 and the plurality of non-sealed portions 45 each extend in the front-rear direction y and are alternately disposed in the width direction x. The sealed portions 44 are formed by joining the sheet members 41 together with an adhesive or by welding (heat sealing, ultrasonic welding, etc.). The non-sealed portions 45 are defined as portions where the sheet members 41 are not joined together, and portions other than the sealed portions 44 correspond to the non-sealed portions 45. Note that the absorbent body 4 may also have the water-absorbent resin 42 disposed in the sealed portions 44.

[0051] In FIG. 3 , an adhesive is applied to a sheet member 41 to form an adhesive layer 43, and a water-absorbent resin 42 is fixed to the sheet member 41 by the adhesive layer 43 in the non-sealed portion 45. The adhesive layer 43 may be provided on at least one of the sheet member 41 on the skin-facing side and the sheet member 41 on the non-skin-facing side, but preferably the adhesive layer 43 is provided on both sheet members 41. It is sufficient that at least a portion of the water-absorbent resin 42 is fixed to the adhesive layer 43. If the water-absorbent resin 42 is fixed to the sheet member 41 by the adhesive layer 43, the water-absorbent resin 42 is less likely to move between the sheet members 41 before absorbing the water-absorbent resin 42, making it easier to ensure the absorption capacity of the absorbent body 4 for urine and the like. Even after absorbing the water-absorbent resin 42, the gelled water-absorbent resin 42 is less likely to move between the sheet members 41, and as a result, the water-absorbent resin 42 is less likely to form clumps, causing discomfort to the wearer.

[0052] It is preferable that the adhesive layer 43 fixes the water-absorbent resin 42 while not inhibiting water absorption or swelling by the water-absorbent resin 42. In order to form such an adhesive layer 43, it is preferable that the adhesive layer 43 is formed by a curtain spray method, a spiral coating method, an omega coating method, a coater method, or the like.

[0053] The sealing portion 44 preferably maintains the bonding between the sheet members 41 even when the water-absorbent resin 42 absorbs water. This makes it easier to ensure the ability of the absorbent body 4 to absorb urine and the like even after the water-absorbent resin 42 has absorbed water. From this perspective, the sealing portion 44 is preferably formed by bonding or welding the sheet members 41 together with an adhesive such as a rubber-based adhesive or a styrene-based elastomer.

[0054] In the absorbent body 4, sealed portions 44 and non-sealed portions 45 are arranged in stripes extending in the front-to-rear direction y. The sealed portions 44 are preferably formed over the entire front-to-rear direction y. If the absorbent body 4 is formed in this manner, urine and the like are more likely to diffuse in the front-to-rear direction y at the sealed portions 44, and urine and the like that have permeated the top sheet 2 and reached the absorbent body 4 are more likely to diffuse in the front-to-rear direction y on the absorbent body 4, making it easier for the urine and the like to be quickly absorbed by the absorbent body 4. Two or more or three or more non-sealed portions 45 are preferably arranged side by side in the width direction x. Three or more or four or more sealed portions 44 are preferably arranged side by side in the width direction x.

[0055] The length in the width direction x of each sealed portion 44 may be 1 mm or more, 2 mm or more, or 10 mm or less. The length in the width direction x of each sealed portion 44 located at the outermost positions in the width direction x may be longer than the length in the width direction x of each sealed portion 44 located more inward than the outermost sealed portion 44 in the width direction x. The length in the width direction x of each sealed portion 44 located at the outermost positions in the width direction x may be 2 mm or more and 10 mm or less. The length in the width direction x of each sealed portion 44 located at the inner side in the width direction x may be shorter than that of the outermost sealed portion 44 in the width direction x, and may be, for example, 1 mm or more and 5 mm or less. With the above configuration, when the water-absorbent resin 42 expands during use of the absorbent article 1, it becomes easy to appropriately suppress the movement and expansion of the water-absorbent resin 42 in the width direction x without hindering swelling.

[0056] The length in the width direction x of each non-sealed portion 45 may be 5 mm or more or 8 mm or more, or may be 50 mm or less, 30 mm or less, or 20 mm or less. The length in the width direction x of each non-sealed portion 45 located outermost in the width direction x may be longer than the length in the width direction x of each non-sealed portion 45 located more inward than the non-sealed portion 45 located outermost in the width direction x.

[0057] The amount of the water-absorbing resin 42 disposed in the non-sealed portion 45 is not particularly limited, and may be, for example, 100 g / m 2 or more than 150g / m2 or more, and 400g / m 2 The water-absorbent resin 42 in the non-sealed portion 45 can be 100 g / m or less. 2 If the amount of the water-absorbent resin 42 is 400 g / m 2 or more, the absorption capacity of the absorbent body 4 can be easily increased. 2 If the amount is as follows, the bonding between the sheet members 41 at the sealing portion 44 can be easily maintained even if the water-absorbing resin 42 absorbs water. [Explanation of symbols]

[0058] 1: Absorbent articles 2: Top sheet 3: Back seat 4: Absorbent 41: Sheet material 42: Water absorbent resin 43: Adhesive layer 44: Sealing part 45: Unsealed part 5: Mount 6: Standing flap 7: Side seat 8: Elastic member for standing up

Claims

1. An absorbent article having a front-rear direction and a width direction, and having a top sheet, a back sheet, and an absorbent body disposed therebetween, The top sheet is made of a nonwoven fabric, and the difference in tensile strength between the front-to-back direction and the width direction is 5.0 N or more, The L when the top sheet is measured from the skin side with a colorimeter ＊ a ＊ b ＊ Lightness according to the color system (L ＊ ) is 60 or more, saturation (C ＊ ) is 5 or less, and the brightness difference between the front-to-back direction and the width direction (ΔL ＊ ) is 1.0 or more, and the saturation difference between the front-to-back direction and the width direction (ΔC ＊ ) is 0.6 or more, and the sum of the lightness difference and the saturation difference (ΔL ＊ +ΔC ＊ ) is 2.0 or more.

2. 2. The absorbent article according to claim 1, wherein the nonwoven fabric is a spunlace nonwoven fabric containing rayon fibers.

3. The spunlace nonwoven fabric contains rayon fibers as well as polyolefin fibers or polyester fibers, 3. The absorbent article according to claim 2, wherein the content of the rayon fibers is 10% by mass or more and 70% by mass or less.

4. 3. The absorbent article according to claim 2, wherein the spunlace nonwoven fabric is formed into a web by a carding method.

5. The absorbent article according to claim 2, wherein the spunlace nonwoven fabric is calendered.

6. 3. The absorbent article according to claim 2, wherein the fineness of the constituent fibers of the spunlace nonwoven fabric is 0.5 dtex or more and 3.5 dtex or less.

7. The absorbent body has a plurality of layered sheet members, a water-absorbent resin is disposed between the sheet members, and pulp fibers are not disposed between the sheet members, The absorbent body has a sealed portion where the sheet members are joined together and an unsealed portion where the sheet members are not joined together, and a water-absorbent resin is disposed in the unsealed portion, The absorbent article according to any one of claims 1 to 6, wherein the non-sealed portions are provided in stripes extending in the front-rear direction.

8. Side sheets are provided on both sides of the top sheet in the width direction, and the side sheets are joined to the top sheet at side joining portions provided on the skin-facing side of the top sheet, The absorbent article according to any one of claims 1 to 6, wherein the side sheets are provided with elastic members extending in the front-rear direction to form rising flaps.

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