Absorbent article

Abstract

The present invention is an absorbent article having a liquid-impermeable back sheet and a skin-side structure part disposed on the skin side of the back sheet. The skin-side structure part has a non-fixed region that includes an absorber part directly disposed on the skin side of the back sheet, and a liquid-permeable top sheet disposed on the skin side of the absorber part, and in which the back sheet and the skin-side structure part are not fixed. In the non-fixed region, the back sheet and the skin-side structure part can slide relative to each other, and the back sheet has a mark with which it is possible to identify deformation, appearance, or disappearance when viewed at least from the skin side when the back sheet and the absorber part have moved relative to each other in the width direction.

Description

Absorbent article

[0001] The present invention relates to an absorbent article.

[0002] Conventionally, as absorbent articles such as menstrual pads, panty liners, incontinence pads, etc., those having a liquid-impermeable back sheet, a liquid-retaining absorbent body, and a liquid-permeable top sheet are known. After fixing such an absorbent article to underwear, sagging or displacement may occur due to shrinkage of the underwear or stress from the crotch. In that case, discomfort often occurs.

[0003] As a means for preventing sagging and displacement and improving the wearing feeling, for example, the wing part is formed by both end parts of an elastic stretchable sheet that crosses the absorbent main body and is fixed to the absorbent main body in an extended state. The fixing parts of the elastic stretchable sheet to the absorbent main body are respectively formed at positions inward in the width direction from both side edges of the absorbent body on at least both sides in the longitudinal direction of the absorbent main body. An absorbent article is known in which the absorbent main body is contracted in the width direction due to the contraction of the elastic stretchable sheet (for example, Patent Document 1).

[0004] Japanese Patent Application Laid-Open No. 2002-369837

[0005] However, in Patent Document 1, after wearing an absorbent article such as a menstrual pad, it is not possible to visually confirm that sagging and displacement are prevented, so it is difficult to feel the effect.

[0006] An aspect of the present invention aims to provide an absorbent article that can recognize that sagging and displacement are prevented after wearing.

[0007] One aspect of the present invention is an absorbent article having an impermeable backsheet and a skin-side structure disposed on the skin side of the backsheet, wherein the skin-side structure includes an absorbent portion directly disposed on the skin side of the backsheet and a permeable top sheet disposed on the skin side of the absorbent portion, the backsheet and the skin-side structure have a non-fixed region in which they are not fixed, the backsheet and the skin-side structure are slidable relative to each other in the non-fixed region, and the backsheet has marks that can be identified as deformed, appearing, or disappearing when the backsheet and the absorbent portion move relative to each other in the width direction, at least when viewed from the skin side.

[0008] According to one embodiment of the present invention, it is possible to provide an absorbent article that can be recognized as preventing twisting or displacement after being attached.

[0009] This is a schematic plan view of an example of an absorbent article according to one embodiment of the present invention, as seen from the skin side. This is a schematic plan view of an example of an absorbent article according to one embodiment of the present invention, as seen from the non-skin side. This is a cross-sectional view taken along line I-I in Figure 1. This is a schematic view of an example of an absorbent article according to one embodiment of the present invention, showing the shape before and after deformation as seen from the skin side. This is an enlarged schematic view of marks M located in regions F1 and F2 of the absorbent article in Figure 4. This is a schematic diagram illustrating a part of the manufacturing process of an example of an absorbent article according to one embodiment of the present invention. These are several examples of marks used in an absorbent article according to one embodiment of the present invention. This is a diagram showing how the marks appear from the skin side before and after use of an absorbent article having some examples of the marks shown in Figure 7A on the backsheet.

[0010] Embodiments of the present invention will be described in detail below with reference to the drawings. In each drawing, unless otherwise specified, the same or corresponding components may be denoted by the same reference numerals and their descriptions may be omitted. Also, the drawings are schematic in order to aid in understanding the invention, and some dimensions may be shown larger or smaller than they actually are. Furthermore, in cross-sectional views, two components may be shown separated to indicate that no other component is interposed between them.

[0011] The absorbent article according to the embodiment of the present invention may specifically be a sanitary napkin, a light incontinence pad, a panty liner, a diaper, etc., but it can be suitably used as a sanitary napkin. In the following, this embodiment will be described based on the example of a sanitary napkin.

[0012] <Absorbent Articles> Figure 1 is a schematic plan view of an example of an absorbent article according to one embodiment of the present invention, as seen from the skin side. Figure 2 is a schematic plan view of an example of an absorbent article according to one embodiment of the present invention, as seen from the non-skin side. Figure 3 is a cross-sectional view taken along line I-I in Figure 1. In the cross-sectional view of Figure 3, the adhesives that bond the layers together are indicated by reference numerals 10, Ad1, and Ad2. In the examples of Figures 1 to 3, adhesives Ad1 and Ad2 are adhesives that join the back sheet 2 and the skin-side structural part 6, and are applied to the back sheet 2 during the manufacture of the absorbent article 1 (details will be described later). In the cross-sectional view of Figure 3, the adhesives join or fix the two members sandwiching the adhesive to each other. Two members laminated without an adhesive in between are in direct contact or can be in direct contact, but are not joined or fixed to each other.

[0013] As shown in Figure 3, the absorbent article 1 is made up of an impermeable backsheet 2, an absorbent portion 4, and a permeable topsheet 3, which are laminated in this order from the non-skin side to the skin side. When the wearer is wearing the absorbent article 1, the topsheet 3 side (skin side) is in contact with the skin. In this specification, the portion of the backsheet 2 laminated on the skin side is called the skin-side structure 6. The skin-side structure 6 is a portion that includes at least the absorbent portion 4 and the topsheet 3, and may also include an intermediate sheet, side sheets, etc., as will be described later. The skin-side structure 6 may also be the entire portion up to the surface that comes into contact with the wearer's skin. The skin-side structure 6 is arranged so that the absorbent portion 4 is directly superimposed on (in direct contact with) the backsheet 2. However, although the absorbent portion 4 of the skin-side structure 6 is mainly in contact with the backsheet 2, the topsheet 3, or another layer other than the absorbent portion 4 and topsheet 3, such as a side sheet 7, may be in contact with the backsheet 2 around the absorbent portion 4. Within the skin-side structural part 6, the components may or may not be fixed to each other, but the absorbent part 4 and the top sheet 3 may be fixed together by adhesive or by embossing.

[0014] The absorbent article 1 may be equipped with wings W extending from both sides. The wings W are for securely fixing the absorbent article 1 to the underwear when worn. The part excluding the wings W is called the main body of the absorbent article (also called the absorbent article body) bd. The absorbent article body bd has an elongated shape with a predetermined length in the front-to-back direction D1 and a predetermined width in the width direction (lateral direction) D2 perpendicular to this front-to-back direction D1. The front-to-back direction (longitudinal direction) D1 of the absorbent article 1 corresponds to the front-to-back direction of the wearer's body when worn, and the width direction (lateral direction) D2 corresponds to the left-to-right direction of the wearer's body. The width of the absorbent article body may be approximately constant, but may vary along the front-to-back direction D1. Furthermore, the absorbent article 1 shown in Figures 1 to 3 has a shape and structure that is approximately symmetrical with respect to the center line (front-to-back center line) CL extending in the front-to-back direction, but the structure of the absorbent article does not necessarily have to be symmetrical.

[0015] The portion Q facing the bodily fluid outlet shown in Figure 1 is the part that faces the wearer's bodily fluid outlet, such as the vaginal opening, when the device is worn, and is located on the center line CL in the anterior-posterior direction. The portion Q facing the bodily fluid outlet may be in the range of 10 mm to 50 mm in the anterior-posterior direction D1 and 10 mm to 30 mm in the width direction D2, but the size of the portion Q facing the bodily fluid outlet is not necessarily limited to the above range.

[0016] The absorbent article 1 has a central region C including a portion Q facing a bodily fluid drainage port, a front region E1 in front of the central region C, and a rear region E2 behind the central region C. The wing W described above may extend laterally from the central region C (outward in the width direction D2). The central region C may be the region corresponding to the crotch area of ​​the wearer's underwear when worn. The central region C may also be the region from one edge to the other in the front-rear direction D1 of the wing W at the position in the width direction D2 where the wing W is connected to the absorbent article body bd (the base end of the wing W).

[0017] The length (total length) of the absorbent article 1 in the front-to-back direction D1 is preferably 150 mm or more and 450 mm or less, more preferably 170 mm or more and 360 mm or less. The thickness of the portion of the absorbent article body bd containing the absorbent part 4 is measured at a location other than the area compressed in the thickness direction, and is preferably 0.3 mm or more and 30 mm or less, more preferably 1.0 mm or more and 15 mm or less. However, the absorbent article body bd may be partially bulged by bulging the absorbent part 4 in a part of the absorbent part 4, for example, the area opposite the body fluid outlet Q and the area near it, and in the center of the width direction D2 of the rear area.

[0018] In addition, one embodiment of the present invention may be an absorbent article without wings W. In that case, assuming that wings W are formed, the region from one edge to the other in the front-rear direction D1 at the base end of the wing W in the width direction D2 can be defined as the central region C.

[0019] On the skin-facing side of the top sheet 3, side sheets 7 are superimposed, extending in the front-to-back direction D1 along both sides of the absorbent portion 4. The side sheets 7 extend to both sides and are joined to the back sheets 2, which similarly extend to both sides, to form wings W. The side sheets 7 can suppress leakage of bodily fluids in the absorbent article 1 and may extend inward in the width direction D2 to form gathers. The absorbent article 1 does not necessarily have side sheets 7; in that case, the wings W may be formed by joining the back sheet 2 with a sheet positioned on the skin-facing or non-skin-facing side of the back sheet 2.

[0020] In the example shown in Figure 1, both the back sheet 2 and the top sheet 3 have the same length in the front-to-back direction D1, extending from the front end to the rear end of the absorbent article 1. On the other hand, the width of the top sheet 3 (length in the width direction D2) may be smaller than the width of the back sheet 2. The absorbent portion 4 is provided sandwiched between the top sheet 3 and the back sheet 2 so as not to be exposed to the outside. For example, as shown in Figure 1, the absorbent portion 4 is arranged so as to fit within the back sheet 2 in a plan view, that is, so as not to protrude from the back sheet 2. The absorbent portion 4 is also configured and arranged so as to fit within the area where the top sheet 3 and the side sheets 7 are provided. For example, the absorbent portion 4 may protrude from the top sheet 3 at both ends in the width direction D2, but in that case, the protruding portion is covered by the side sheets 7. Furthermore, in the example shown in Figure 1, for convenience, the mark M (described in detail later) on the back sheet 2 is not shown, but when an unused absorbent article 1 is viewed from the skin side, part or all of the mark M may be faintly visible through the top sheet 3, side sheet 7, or other sheets.

[0021] As the backsheet 2, a sheet material having at least water-impermeable properties can be used, such as an olefin resin sheet made of polyethylene or polypropylene. Laminated nonwoven fabrics, such as polyethylene sheets laminated with nonwoven fabric, or laminated nonwoven fabric sheets with a waterproof film interposed to ensure substantially liquid impermeability can be used. Furthermore, it is even more preferable to use a material that has moisture permeability from the viewpoint of preventing stuffiness. As such a water-impermeable and moisture-permeable sheet material, a microporous sheet obtained by melt-kneading an inorganic filler into an olefin resin such as polyethylene or polypropylene, forming a sheet, and then stretching it in a uniaxial or biaxial direction can be used.

[0022] The top sheet 3 is a permeable sheet that allows bodily fluids such as menstrual blood, vaginal discharge, and urine to pass through quickly. Suitable materials for the top sheet 3 include perforated or non-perforated nonwoven fabrics and porous plastic sheets. Suitable materials for the nonwoven fabric include, for example, olefins such as polyethylene and polypropylene, synthetic fibers such as polyester and polyamide, regenerated fibers such as rayon and cupro, and blends thereof, as well as natural fibers such as cotton, which can be used individually or in combination of two or more. Processing methods for the nonwoven fabric include the spunlace method, spunbond method, thermal bond method, meltblown method, and needle punch method. Of these processing methods, the spunlace method is preferred for producing flexible nonwoven fabrics, the spunbond method for producing nonwoven fabrics with good drape, and the thermal bond method for producing bulky and soft nonwoven fabrics. Furthermore, composite fibers such as core-sheath type fibers, side-by-side type fibers, and split type fibers, which use fibers with high melting points as a core and fibers with low melting points as a sheath, can be used. The nonwoven fabric processed by the above processing method is preferably a short-fiber nonwoven fabric. Short-fiber nonwoven fabrics are often composed of fine fibers and have fewer fused parts, making them soft, pleasant to the touch, and transparent. From the viewpoint of low density and transparency, the short-fiber nonwoven fabric that can be used for top sheet 3 has a basis weight of 15 to 50 gsm (g / m²). ２ It is preferable that the amount is 15 to 30 gsm, and more preferably 15 to 30 gsm.

[0023] The side sheet 7 is preferably at least one of nonwoven fabric and crepe paper. There are no particular restrictions on the nonwoven fabric, but examples include air-through nonwoven fabric and cotton spunlace nonwoven fabric. The side sheet 7 has a basis weight of 10 to 30 g / m². ２ Preferably, it is 15 to 30 g / m ２ It is more preferable that the side sheet 7 prevents bodily fluids from leaking from the top sheet. When the absorbent article 1 is viewed from the skin side, if the side sheet 7 covers the mark on the back sheet, the side sheet is made of nonwoven fabric, crepe paper, etc., with a basis weight of 10 to 30 g / m². ２ Within this range, even if the backsheet and absorbent portion move relative to each other in the width direction, the deformation, appearance, or disappearance of the mark can be identified at least from the skin side, through the sidesheet.

[0024] Furthermore, as shown in Figure 1, it is preferable that the outer end of the non-fixed region 9 in the width direction D2 and the outer end of the absorbent portion 4 in the width direction D2 are separated by a length k in the width direction D2. This separation provides play for the absorbent portion 4, making it easier for the absorbent portion 4 to move relative to the backsheet 2. Also, when the side sheet 7 covers the backsheet 2 and at least one of the absorbent portion 4 and the top sheet 3, the separation between the outer end of the non-fixed region 9 in the width direction D2 and the outer end of the absorbent portion 4 in the width direction D2 makes it easier for the side sheet 7 to stretch when the backsheet 2 and the absorbent portion 4 move relative to each other in the width direction. In addition, as the side sheet 7 stretches, its thickness decreases, making it easier to recognize the deformation, appearance, or disappearance of the mark M on the backsheet 2 below the side sheet 7 from the skin side. The length k of the width direction D2 between the outer end of the non-fixed region 9 and the outer end of the absorbent portion 4 is preferably 0.5 mm or more and 5 mm or less, and more preferably 1 mm or more and 3.5 mm or less.

[0025] For the nonwoven fabric used in the side sheet 7, a water-repellent nonwoven fabric or a hydrophilic nonwoven fabric can be used. For example, to prevent menstrual blood or vaginal discharge from penetrating or to enhance the feel against the skin, it is preferable to use a water-repellent nonwoven fabric coated with a silicone-based or paraffin-based water-repellent agent. Also, to improve the absorbency of menstrual blood, etc., in the wing W, it is preferable to use a hydrophilic nonwoven fabric as the nonwoven fabric material. As for the type of nonwoven fabric, a nonwoven fabric that is soft, does not easily crease or wrinkle, such as an air-through nonwoven fabric or a point-bonded nonwoven fabric is preferred, and a short-fiber nonwoven fabric is even more preferable. Short-fiber nonwoven fabrics are often composed of fine fibers and have few fused parts, so they tend to be fluffy, have a good feel against the skin, and are transparent. From the viewpoint of low density and transparency, the short-fiber nonwoven fabric that can be used in the side sheet 7 has a basis weight of 10 to 50 gsm (g / m²). ２ It is preferable that the amount be 15 to 50 gsm, and more preferably 15 to 30 gsm.

[0026] As shown in Figure 3, the absorbent section 4 can be configured to include an absorbent body 4a that substantially performs the function of absorbing bodily fluids, and a covering sheet 4b that encloses the absorbent body 4a.

[0027] The materials constituting the absorbent body 4a are not limited as long as they can absorb and retain bodily fluids, but it is preferable that they include cotton-like pulp and a superabsorbent polymer. As the superabsorbent polymer, superabsorbent polymer granules (SAP), superabsorbent polymer fibers (SAF), and combinations thereof can be used. As the pulp, examples include cellulose fibers such as chemical pulp and dissolved pulp obtained from wood, and artificial cellulose fibers such as rayon and acetate. Recycled pulp and recycled fibers can also be used. As raw materials for chemical pulp, hardwoods and softwoods can be used, but softwoods are preferably used because of their long fiber length. The absorbent body 4a can be manufactured by the fiber stacking or airlaid method. Furthermore, as the absorbent body 4a, a thin sheet consisting of a layer of superabsorbent polymer granules and / or superabsorbent polymer fibers sandwiched between sheets of nonwoven fabric or the like, a so-called SAP sheet, can also be used. When an SAP sheet is used, the encasing sheet 4b can be omitted.

[0028] Furthermore, synthetic fibers may be mixed into the absorbent body 4a. As synthetic fibers, polyolefins such as polyethylene and polypropylene, polyesters such as polyethylene terephthalate and polybutylene terephthalate, polyamides such as nylon, and copolymers thereof can be used, and two of these can also be mixed and used. In addition, composite fibers such as core-sheath fibers, side-by-side fibers, and split fibers, with a high-melting-point fiber as the core and a low-melting-point fiber as the sheath, can also be used. Furthermore, hydrophobic fibers can be surface-treated with a hydrophilizing agent to impart affinity to body fluids.

[0029] The structure in which the absorbent body 4a is wrapped by the covering sheet 4b prevents the fibrous or granular material contained in the absorbent body 4a from spilling out, and also prevents the entire absorbent part 4 from becoming distorted or cracked, thus improving the shape retention of the absorbent part 4. However, the covering sheet 4b is not necessarily required.

[0030] The material of the covering sheet 4b is not particularly limited, but may be nonwoven fabric, paper, etc. As for nonwoven fabrics, air-through nonwoven fabric, spunbond nonwoven fabric, flexible spunbond nonwoven fabric, etc. are used. As for paper, crepe paper is used. When the absorbent body 4a is wrapped by the covering sheet 4b, the back sheet 2 and the covering sheet 4b will be in direct contact within the absorbent article 1. Therefore, from the viewpoint of reducing friction between the back sheet 2 and the absorbent body 4, and consequently friction between the back sheet 2 and the skin-side structure 6 on the skin side of the back sheet 2, an air-through nonwoven fabric is preferred.

[0031] Furthermore, an intermediate sheet may be provided between the top sheet 3 and the absorbent portion 4 to facilitate the transfer and diffusion of bodily fluids that have reached the top sheet 3 toward the non-skin side and / or in the planar direction. However, the intermediate sheet 5 may be omitted. If an intermediate sheet is provided, the material of the intermediate sheet can be, for example, the same material as the top sheet 3 described above.

[0032] <Non-fixed area> As shown in Figures 1 to 3, in the absorbent article 1 according to one embodiment of the present invention, the absorbent article body bd has a non-fixed area 9 in which the back sheet 2 and the skin-side structural part 6 directly arranged on the skin side of the back sheet 2 are not fixed. The back sheet 2 may have a slip-prevention mechanism for fixing the absorbent article 1 to underwear, and the slip-prevention mechanism is located on the non-skin side of the back sheet 2. In the cross-sectional view of Figure 3, the back sheet 2 and the absorbent part 4 are shown separated, but this is shown to indicate that there is no other member interposed between the back sheet 2 and the absorbent part 4, and the back sheet 2 and the absorbent part 4 are in direct contact or can be in direct contact in the thickness direction.

[0033] In this specification, "relatively slidable" means that the two components are relatively slidable due to the force applied to the absorbent article when the user of the absorbent article handles it in the normal manner, and that this sliding is perceptible to the user of the absorbent article in the normal manner (i.e., through human senses such as sight and touch).

[0034] The non-fixed region 9 is a region in which the backsheet 2 and the skin-side structure 6 are not bonded together by adhesive or other means, and the backsheet 2 and the skin-side structure 6 are relatively slidable. More specifically, it includes a region in which the backsheet 2 and the absorbent portion 4 are not bonded together and are relatively slidable. Furthermore, within the non-fixed region 9, not only the absorbent portion 4 but also the top sheet 3 may be slidable relative to the backsheet 2, or layers other than the absorbent portion 4 and the top sheet 3, such as the side sheet 7, may be slidable relative to the backsheet 2. Thus, inside the absorbent article 1, the skin-side structure 6 can move along the surface of the backsheet 2 facing the skin-side structure 6, and the backsheet 2 can move along the surface of the skin-side structure 6 facing the backsheet 2. As a result, the skin-side structure 6 can follow the skin, and the backsheet 2 can follow the underwear. Therefore, regardless of the movement of the back sheet 2, the skin-side structure 6 can follow the wearer's skin well while remaining in close contact with it (high conformability to the skin is achieved).

[0035] In the non-fixed region 9, the back sheet 2 and the skin-side structure 6 are directly laminated, and no other material is interposed between them. Therefore, in the manufacture of the absorbent article 1 according to this embodiment, the number of materials can be reduced, and the manufacturing process can also be simplified.

[0036] Furthermore, since the wearer can easily sense the presence or absence of bodily fluid leakage, especially near the bodily fluid outlet, it is preferable that a non-fixed area 9 is formed in the central region C, which includes the bodily fluid outlet facing portion Q opposite the bodily fluid outlet. It is also preferable that the non-fixed area 9 extends across the entire central region C, and more preferably extends beyond the front and rear ends of the central region C, as shown in Figures 1 and 2.

[0037] The area of ​​the non-fixed region 9 in the overlapping region between the backsheet 2 and the absorbent portion 4, that is, the area of ​​the non-fixed region 9 relative to the area of ​​the absorbent portion 4, is preferably 50% or more, more preferably 70% or more. Having the non-fixed region 9 be 50% or more of the absorbent portion 4 further improves the skin conformity of the absorbent article 1. The area of ​​the non-fixed region 9 in the absorbent article body bd, that is, the area of ​​the non-fixed region 9 relative to the area of ​​the absorbent article body bd, is also preferably 50% or more, more preferably 70% or more.

[0038] In the example shown in Figure 1, the non-fixed area 9 may be formed to include the longest width. Also, 70% or more of the area of ​​the absorbent portion 4 may be included in the non-fixed area 9. This makes it easier for the width direction D2 of the absorbent portion 4 to slide relative to the backsheet 2, thereby further improving the skin conformity of the skin-facing surface of the absorbent article 1 to the skin. The non-fixed area 9 may include 75% or more, 80% or more, 85% or more, 90% or more, or 95% or more of the area of ​​the absorbent portion 4. The larger the area of ​​the absorbent portion 4 included in the non-fixed area 9, the easier it is for the width direction D2 of the absorbent portion 4 to slide relative to the backsheet 2. In the example shown in Figure 1, 86% of the area of ​​the absorbent portion 4 is included in the non-fixed area 9. Also, the non-fixed area 9 may be formed across both ends of the width direction D2 of the absorbent article body bd. In that case, it is preferable that the edges of the absorbent article body bd in the width direction D2 are closed by applying adhesive to the edges or by applying a sealing process such as heat sealing in the front region E1 and rear region E2 in the configuration with wings W, and over the entire front-to-back direction D1 in the configuration without wings W. Furthermore, as shown in Figure 3, in the configuration with wings W, it is preferable that the back sheet 2 and the side sheet 7 are bonded together with adhesive Ad2.

[0039] Furthermore, as shown in FIG. 1, it is preferable that the outer end in the width direction D2 of the non-fixed region 9 and the outer end in the width direction D2 of the absorber portion 4 are separated from each other by a length k in the width direction D2. This separation serves as play for the absorber portion 4, making it easier for the absorber portion 4 to move relative to the backsheet 2, thereby enhancing the followability of the skin-side structure portion 6 to the skin. The length k in the width direction D2 between the outer end in the width direction D2 of the non-fixed region 9 and the outer end in the width direction D2 of the absorber portion 4 may preferably be 0.5 mm or more and 5 mm or less, and more preferably 1 mm or more and 3.5 mm or less.

[0040] Note that it is only necessary that the backsheet 2 and the skin-side structure portion 6 are relatively slidable, and the end portion of the absorber portion 4 in the width direction D2 and the backsheet 2 may be adhered along the front-rear direction D1. In that case, the length in the width direction D2 where the backsheet 2 and the absorber portion 4 are adhered may preferably be 0.5 mm or more and 3 mm or less, and more preferably 0.5 mm or more and 1 mm or less.

[0041] As described above, the non-fixed region 9 is a region where the backsheet 2 and the skin-side structure portion 6 are relatively slidable. Therefore, it is preferably a region having a certain continuous area. For example, the non-fixed region 9 is preferably a continuous region having a maximum length in the front-rear direction D1 of 50 mm or more and a maximum length in the width direction D2 of 50 mm or more, and more preferably a continuous region having a maximum length in the front-rear direction D1 of 60 mm or more and a maximum length in the width direction D2 of 60 mm or more. Furthermore, the non-fixed region 9 may be a continuous region having a maximum length in the front-rear direction D1 that is equal to or greater than the length of the central region C in the front-rear direction D1 and a maximum length in the width direction D2 that is equal to or greater than the length of the absorber portion 4 in the width direction D2.

[0042] Furthermore, in the present embodiment, when the backsheet 2 and the skin-side structure portion 6 are pulled in the opposite direction in the width direction D2, the relative movement distance d1 in the width direction D2 between the backsheet 2 and the skin-side structure portion 6 can be 10 mm or more. This movement distance d1 may preferably be 15 mm or more, more preferably 20 mm or more, and even more preferably 30 mm or more, although it also depends on the overall size of the absorbent article 1. The above movement distance d1 may be a distance measured by the force applied when handling the absorbent article in a normal usage method.

[0043] Thus, the non-fixed region 9 is a region within the absorbent article 1 where members can slide relative to each other, and is a portion that affects the followability of the absorbent article 1 to the skin on the skin side surface of the absorbent article 1, which is likely to deform after wearing.

[0044] <Fixed Region> The absorbent article 1 may include a fixed region 8, which is a region other than the non-fixed region 9, where at least one of the backsheet 2 and the absorber portion 4 and the topsheet 3 is fixed by an adhesive or other adhesion means. In the examples shown in FIGS. 1 and 2, the fixed region 8 is formed by fixing at least one of the backsheet 2 and the absorber portion 4 and the topsheet 3 in each of the front region E1 and the rear region E2.

[0045] In the present embodiment, the location where the fixed region 8 is formed may be either the front region E1 or the rear region E2. Also, the absorbent article 1 can be configured such that the fixed region 8 is not formed, that is, the non-fixed region 9 is formed over the entire absorbent article body bd. In a form where the fixed region 8 is not formed overall, the backsheet 2 and the skin-side structure portion 6 can slide more easily (with respect to a smaller force) over a wider range, which is preferable in terms of improving the followability of the skin-side structure portion 6 to the skin. On the other hand, a configuration in which the absorbent article body bd has the fixed region 8 is preferable in terms of preventing the laminated structure of the absorbent article 1 from breaking even when a large force is applied to the absorbent article 1 and improving the robustness of the absorbent article 1. When the fixed region 8 is formed in the front region E1, the length in the front-rear direction D1 of the fixed region 8 from the front end of the front region E1 may be preferably 30% or more and 80% or less, more preferably 50% or more and 70% or less, of the length in the front-rear direction D1 of the front region E1. Also, when the fixed region 8 is formed in the rear region E2, the length in the front-rear direction D1 of the fixed region 8 from the rear end of the rear region E2 may be preferably 30% or more and 85% or less, more preferably 40% or more and 70% or less, of the length in the front-rear direction D1 of the rear region E2.

[0046] In this specification, "relatively slidable" means that the two components are able to slide relative to each other due to the force applied to the absorbent article when the user of the absorbent article handles it in the normal manner, and that this sliding is perceptible to the user of the absorbent article in the normal manner (i.e., through human senses such as sight and touch). Therefore, even if there is a portion within the fixed area 8 where the back sheet 2 and at least one of the absorbent part 4 and the top sheet 3 are not fixed by adhesive or the like, if the two cannot slide relative to each other, that portion is not included in the "unfixed area".

[0047] <Mark> Since the absorbent article 1 has a non-fixed area 9, as described above, the skin-side structure 6 can follow the skin and the back sheet 2 can follow the underwear. Therefore, regardless of the movement of the back sheet 2, the skin-side structure 6 can follow the skin well while remaining in close contact with the wearer's skin. Here, in the absorbent article 1 according to this embodiment, as shown in Figure 2, the back sheet 2 has a mark M, and when the back sheet 2 and the skin-side structure 6 move relative to each other, the change in the mark M is discernible (deformation, appearance, or disappearance is discernible) at least from the skin side. Therefore, the wearer can feel that the absorbent article 1 fits well to the groin area and can recognize that wrinkles and displacement are prevented after wearing.

[0048] In the example shown in Figure 2, the backsheet 2 has a mark M consisting of four straight lines, and on the backsheet 2, the mark M is located in a part of the central region C. The central region C includes a body fluid outlet opposing portion Q that faces the wearer's body fluid outlet when worn. Since body fluid is discharged from the wearer's body fluid outlet, the area of ​​the absorbent article 1 that comes into contact with the skin, especially the body fluid outlet opposing portion Q, fits snugly against the skin, preventing wrinkles and displacement after wearing, thereby making it easier to prevent leakage of body fluid from the absorbent article. In other words, by positioning the mark M in the central region C, which includes the body fluid outlet opposing portion Q, which is the optimal location for a snug fit against the skin, the wearer can more easily identify the deformation, appearance, or disappearance of the mark M after using the absorbent article 1 when viewed from the skin side. This makes it easier to recognize that wrinkles and displacement have been prevented after using the absorbent article 1.

[0049] Furthermore, in Figure 2, mark M is also depicted in a portion of the front region E1, which is forward of the central region C, and in a portion of the rear region E2, which is backward of the central region C. The presence of mark M in the front region E1 and / or rear region E2 means that even if the wearer is unable to properly position the absorbent article 1 in the underwear, for example, if the bodily fluid outlet (vaginal opening, urethral opening, etc.) is not aligned within the central region C and the article is worn so that it extends into the front region E1 or rear region E2, mark M will still be present in the region D1 in the front-to-back direction that is actually aligned with the bodily fluid outlet. Therefore, regardless of the wearer's actual wearing condition, the wearer can recognize that wrinkles and misalignment of the absorbent article after wearing are prevented by identifying the deformation, appearance, or disappearance of mark M.

[0050] Mark M should be located in a position where it can be identified as deformed, appearing, or disappearing when the backsheet 2 and the skin-side structural part 6 move relative to each other, at least from the skin side. In addition to the above, it is preferable that it is located within the non-fixed region 9, which is a region where the absorbent part 4 is easily deformed, or within the range D1 in the front-to-back direction where the non-fixed region 9 is formed. Furthermore, since it is easier to check the displacement between the absorbent part 4 and the backsheet 2 when viewed from the skin side, it is more preferable that it is located in a region that overlaps with the absorbent part 4 and within 5 mm from the widthwise end of the absorbent part 4 toward the front-to-back center line CL. Also, it is sufficient that Mark M is visible from the skin side, and it may be on either the non-skin side or the skin side of the backsheet 2.

[0051] The shape, type, color, and number of marks M are not particularly limited, as long as the deformation, appearance, or disappearance of the marks M can be identified, at least from the skin side, when the backsheet 2 and the absorbent part 4 move relative to each other in the width direction. Preferably, marks M include at least one of the following: straight lines, wavy lines, dashed lines, letters, symbols, polygons, circles, ellipses, heart shapes, houndstooth patterns, checkered patterns, spiral patterns, dots, and stripes. By including at least one of the following for marks M, a variety of designs can be selected for marks M, resulting in absorbent articles that are not only functional but also aesthetically pleasing. Furthermore, marks of types other than those shown above can be used as marks M, as long as they do not hinder the purpose of the present invention. The number of marks M may be single or multiple. When the backsheet 2 and the absorbent part 4 move relative to each other in the width direction, it is sufficient for a part of the mark M to deform, appear, or disappear, but the entire mark M may also deform, appear, or disappear. Alternatively, the deformation, appearance, or disappearance of a part of the mark M may be considered as the deformation, appearance, or disappearance of the mark M. In this specification, one of the elements constituting the mark M is also referred to as a "mark". For example, in the example in Figure 2, two marks M are formed by four lines, more specifically, one on each side of the center line CL, but each mark 11, which is an element constituting each mark M, is a single line. Note that if there is only one mark 11 in a single mark M, the mark 11 itself becomes the mark M.

[0052] Figure 4 is a schematic diagram showing the shape of the absorbent article 1 before and after deformation, as viewed from the skin side, when the absorbent article 1 according to one embodiment of the present invention is worn. Figure 4(a) shows the shape of the absorbent article 1 before deformation, and Figure 4(b) shows the shape of the absorbent article 1 after deformation. The absorbent article 1 shown in Figure 4 is a modified example of the absorbent article 1 described with reference to Figures 1 to 3, and the position of the mark M on the back sheet 2 is different from the example shown in Figures 1 to 3. In the example shown in Figure 4, the mark M is located further out in the width direction D2 than in the example shown in Figure 2, and in the state before deformation (Figure 4(a)), a part of it is visible through the side sheet 7. Also, in the example shown in Figure 4, as the mark M, four lines (four marks 11) are drawn in the central region C with wings, but two lines are drawn in the front region E1 and the rear region E2.

[0053] Furthermore, Figures 5(a) and 5(b) are enlarged views of region F1 in Figure 4(a) and region F2 in Figure 4(b), respectively.

[0054] The appearance of the mark M before and after deformation of the absorbent article 1 will be explained in more detail below with reference to Figures 4 and 5. When the absorbent article 1 before deformation is viewed from the skin side, a portion of the mark M not covered by the absorbent part 4 is faintly visible through the sheet on top of the back sheet, and in region F1, three straight lines are visible as the mark M (Figures 4(a) and 5(a)). On the other hand, when the absorbent article 1 after deformation is viewed from the skin side, one line appears in region F2, and four straight lines are visible as the mark M (Figures 4(b) and 5(b)). Also, on the left side when viewed from the skin side, the lines of the mark M that were visible in the central region C, the front region E1, and the rear region E2 after the deformation of the absorbent article 1 have also deformed; that is, the lines that were straight as a whole are partially curved (Figure 4(b)). Furthermore, on the right side when viewed from the skin side, after the absorbent article 1 is deformed, some of the lines of mark M that were visible in the central region C, the front region E1, and the rear region E2 have disappeared, and the lines of mark M visible from the skin side have deformed from a straight line to a curved shape (Figure 4(b)). In this way, after the absorbent article 1 is worn, the back sheet 2 and the skin-side structure 6 slide relative to each other, and as the skin-side structure 6 conforms to the skin and deforms, the wearer can identify that the mark M on the back sheet 2 has deformed, appeared, or disappeared.

[0055] Figure 7A shows an example of a mark M used in an absorbent article according to one embodiment of the present invention. As shown in Figure 7A, it is preferable that the mark M as a whole be a linear pattern along the front-to-back direction D1, so that the presence or degree of distortion or misalignment of the absorbent article 1 can be recognized along the front-to-back direction D1. The mark M may be continuous or discontinuous along the front-to-back direction D1. However, it is preferable that one or more elements included in the mark M extend continuously along the front-to-back direction D1 (Figures 7A(a), (b), (g)), as this strengthens the continuity of the mark M along the front-to-back direction D1, making it easier to check for changes in the mark over the entire range along the front-to-back direction D1 when the absorbent article 1 is deformed. Similarly, even if the elements of the mark M themselves are not continuous along the front-to-back direction D1, if multiple elements of the mark M arranged in the width direction D2 overlap along the front-to-back direction D1, the mark M as a whole appears continuous along the front-to-back direction D1 (Figures 7A(a), (c), (d), (h)), the continuity of the front-to-back direction D1 is guaranteed to some extent.

[0056] Figure 7B shows how the marks M shown in Figure 7A appear from the skin side before and after use of the absorbent article, when marks (f) to (g) are present on the backsheet 2. In Figure 7B, below each mark M, an example of how the marks M appear before and after use of the absorbent article is shown. Before use of the absorbent article, a portion of each mark M is hidden by the absorbent part 4. After use of the absorbent article, the absorbent part 4 adheres closely to the skin, allowing it to slide in the direction of the arrow. This sliding of the absorbent part 4 reveals a portion of the mark M that was hidden by the absorbent part 4 before use. By recognizing this change in the appearance of the marks M, the wearer of the absorbent article can recognize that wrinkles and displacement have been prevented after wearing the absorbent article.

[0057] Figure 6 is a schematic diagram illustrating a part of the manufacturing process of an example of an absorbent article according to one embodiment of the present invention. In Figure 6, an adhesive is applied to a long backsheet strip 2A with a mark M printed on it, while it is being transported with its length direction being the transport direction DT. Preferably, the mark M is printed in the area that will become the non-fixed area 9. It is also preferable that it is printed on the area that overlaps with the absorbent part 4. Preferably, it is printed in a range of 5 mm or less from the end in the width direction of the absorbent part 4 toward the center line CL in the front-rear direction. For example, a hot melt adhesive is used as the adhesive. In the backsheet strip 2A, the planned cutting contour of the absorbent article 1 is set in the shape of the backsheet 2. Then, adhesive Ad1, which corresponds to the adhesive used for the fixed area 8 in the final absorbent article 1, is applied intermittently to the center of the backsheet strip 2A in the direction perpendicular to the transport direction DT (center of the width direction D2 of the absorbent article 1), so that the non-fixed area 9 will be formed later. However, in this case, the coating is applied continuously over an area that spans the rear region E2 of one absorbent article and the front region E1 of another absorbent article adjacent to that absorbent article 1. Furthermore, on the outside of the backsheet strip 2A in a direction perpendicular to the transport direction DT (outside the width direction D2 of the absorbent article 1), the adhesive Ad2 that bonds the wing W of the final product absorbent article 1 to the backsheet 2 is applied continuously. In this way, the absorbent articles of the present invention only require marking the backsheet and do not require increasing the number of materials, making it easier to manufacture the absorbent articles and suppressing increases in manufacturing costs.

[0058] The areas indicated by adhesive Ad1 and adhesive Ad2 in Figure 6 both represent areas where each adhesive can be applied. Each adhesive may be applied as a solid coating within these areas, or as dots or lines. For example, it may be linear, curved, spiral, etc., extending along the transport direction DT. A hot melt coater, more specifically a gravure coater, spray coater, spiral gun, bead gun, etc., can be used to apply adhesives Ad1 and Ad2.

[0059] After applying the adhesive, the absorbent portion 4, the long top sheet strip which will become the top sheet 3, and the long side sheet strip which will become the side sheet 7 can be overlapped with adhesive as needed, and after heat sealing or the like may be applied, they can be cut to obtain the absorbent article 1 (Figures 1, 2, etc.).

[0060] The absorbent article 1 described above was a product with wings, but the same effect can be obtained with a product without wings using the above configuration. However, the product with wings allows the back sheet 2 to be firmly fixed to the underwear, making it easier for the back sheet 2 and the skin-side structure 6 to slide relative to each other, thus improving the wearing comfort.

[0061] Furthermore, the technology of the present invention can be applied to diapers as well as sanitary napkins, panty liners, and incontinence pads, but it is particularly suitable for sanitary napkins. Since sanitary napkins are often used with the skin side in close contact with the groin or other genital area, friction between the absorbent material and the skin is more likely to occur due to the wearer's movements compared to other absorbent items. Therefore, by using the embodiment of the present invention in sanitary napkins, it is easier to recognize that bunching and shifting are prevented after wearing, and the effects of the present invention can be more fully appreciated.

[0062] Although the present invention has been described above based on embodiments, the present invention is not limited to these embodiments. The above embodiments can be modified, altered, replaced, added, deleted, and combined in various ways within the scope of the claims, and these also fall within the technical scope of the present invention. Furthermore, the above-mentioned components can be combined in any way.

[0063] The specific aspects of this disclosure are further described below.

[0064] (Note 1) The embodiment of Note 1 is an absorbent article having an impermeable backsheet and a skin-side structure disposed on the skin side of the backsheet, wherein the skin-side structure includes an absorbent portion directly disposed on the skin side of the backsheet and a permeable topsheet disposed on the skin side of the absorbent portion, and the backsheet and the skin-side structure have a non-fixed region in which they are not fixed, the backsheet and the skin-side structure are slidable relative to each other in the non-fixed region, and the backsheet has marks that can be identified as deformed, appearing, or disappearing when the backsheet and the skin-side structure move relative to each other in the width direction, at least when viewed from the skin side.

[0065] Absorbent items are used by attaching them to underwear with the backsheet side facing outwards. When the wearer's body moves, the underwear moves in accordance with that movement, and the absorbent item also moves in accordance with the movement of the underwear (including deformation and / or shifting). In this case, even though the absorbent item moves in accordance with the movement of the underwear, the skin in the crotch area to which the skin-facing side of the absorbent item is in contact does not move much, so friction is likely to occur between the skin-facing side (topsheet side) of the absorbent item and the skin in contact with that side. As a result, after attaching the absorbent item, the feeling of wearing it may be impaired due to wrinkles or displacement, and this is especially likely to occur when the absorbent item is worn for a long time or when there is vigorous movement.

[0066] In contrast, the absorbent article according to the embodiment described in Appendix 1 above has an unfixed area where the backsheet and the skin-side structure are not fixed, and is configured so that the backsheet and the skin-side structure can slide relative to each other. As a result, one of the opposing backsheets and skin-side structures can move independently along the surface relative to the other. Therefore, even if the backsheet moves in accordance with the movement of the underwear while the absorbent article is in close contact with the wearer's skin, the movement of the backsheet is not directly transmitted to the skin-side structure, preventing the absorbent article from rubbing against the skin, thus preventing the absorbent article from bunching up or shifting out of position. In other words, because the components inside the absorbent article are relatively slidable, even if the backsheet moves in accordance with the underwear, the skin-side surface of the absorbent article can follow the wearer's skin and maintain close contact with the skin, resulting in a good fit to the skin. This makes bunching up and shifting out of position less likely, resulting in a better wearing experience.

[0067] Furthermore, in this embodiment, even if the backsheet conforms to the underwear, the skin-facing structural portion of the absorbent article can maintain close contact with the wearer's skin. Therefore, when the backsheet and the absorbent portion move relative to each other in the width direction due to the wearer's use of the absorbent article, the deformation, appearance, or disappearance of the mark on the backsheet can be identified, at least from the skin side. By identifying this deformation, appearance, or disappearance of the mark, the wearer can feel that the absorbent article fits well in the groin area and recognize that wrinkles and displacement are prevented after wearing.

[0068] Furthermore, in this embodiment, the backsheet and the skin-side structure are arranged in contact, eliminating the need to interpose an additional layer between them and the absorbent portion. As a result, the number of materials and manufacturing processes can be reduced in the production of absorbent articles, thereby lowering manufacturing costs.

[0069] Furthermore, in this embodiment, it is only necessary to mark the back sheet, and there is no need to increase the number of materials, making it easier to manufacture absorbent articles and suppressing increases in manufacturing costs.

[0070] (Note 2) The embodiment of Note 2 is an absorbent article in which the mark is located in part or all of the central region, including the portion facing the body fluid outlet that is opposite to the body fluid outlet of the wearer when the article is worn.

[0071] Because bodily fluids are discharged from the wearer's bodily fluid outlets, the area of ​​the absorbent article that comes into contact with the skin, particularly the part facing the bodily fluid outlets, fits snugly against the skin, preventing wrinkles and displacement after application, thereby making it easier to prevent leakage of bodily fluids from the absorbent article. According to the embodiment described in Appendix 2 above, by positioning the mark in part or all of the central area including the part facing the bodily fluid outlets, the wearer can easily identify deformation, appearance, or disappearance of the mark, and recognize that wrinkles and displacement of the absorbent article have been prevented after application.

[0072] (Note 3) The embodiment of Note 3 is an absorbent article in which the mark is located in at least one of the following areas: a part or all of the front area in front of the central area, and a part or all of the rear area behind the central area.

[0073] According to the embodiment described in Appendix 3 above, even if the part facing the bodily fluid drainage port protrudes into the front or rear area when using the absorbent article, the mark can be positioned particularly close to the part facing the bodily fluid drainage port, which is more likely to fit the skin. This allows the wearer to recognize that wrinkles and misalignment of the absorbent article after application have been prevented by identifying the deformation, appearance, or disappearance of the mark.

[0074] (Note 4) The embodiment of Note 4 has a side sheet on the skin side of the top sheet, and the side sheet has a basis weight of 10 to 30 g / m². ２ It is an absorbent article that is at least one of nonwoven fabric or crepe paper.

[0075] According to the embodiment described in Appendix 4 above, the side sheet can prevent bodily fluids from leaking from the top sheet in the width direction. When viewed from the skin side, the side sheet covers the mark on the back sheet, and the side sheet is made of at least one of nonwoven fabric or crepe paper with a basis weight of 10 to 30 g / m². ２Within this range, even if the backsheet and absorbent portion move relative to each other in the width direction, the deformation, appearance, or disappearance of the mark can be identified at least from the skin side, through the sidesheet.

[0076] (Note 5) The aspect of Note 5 is an absorbent article in which the mark includes at least one of the following: a straight line, a wavy line, a dashed line, letters, symbols, a polygon, a circle, an ellipse, a heart shape, a houndstooth pattern, a checkered pattern, a spiral pattern, a dot, and a stripe.

[0077] According to the embodiment described in Appendix 5 above, various designs can be selected for the mark, making it possible to create absorbent articles that are not only highly functional but also aesthetically pleasing.

[0078] This application claims priority based on Japanese Patent Application No. 2024-169800, filed on 30 September 2024, the entire contents of which are incorporated herein by reference.

[0079] 1 Absorbent article 2 Backsheet 2A Backsheet strip 3 Top sheet 4 Absorbent section 4a Absorbent body 4b Wrapping sheet 5 Intermediate sheet 6 Skin-side structure 7 Side sheet 8 Fixed area 9 Non-fixed area 10 Adhesive 11 Mark Ad1 Adhesive Ad2 Adhesive bd Absorbent article body Q Opposite part of body fluid outlet W Wing M Mark CL Front-to-back center line D1 Front-to-back direction (longitudinal direction) D2 Width direction (lateral direction) DT Conveying direction

Claims

1. An absorbent article having an impermeable backsheet and a skin-side structure disposed on the skin side of the backsheet, wherein the skin-side structure includes an absorbent portion directly disposed on the skin side of the backsheet and a permeable topsheet disposed on the skin side of the absorbent portion, the backsheet and the skin-side structure have a non-fixed region where they are not fixed, the backsheet and the skin-side structure are relatively slidable within the non-fixed region, and the backsheet has marks that can be identified as deformed, appearing, or disappearing when the backsheet and the skin-side structure move relatively in the width direction, at least when viewed from the skin side.

2. The absorbent article according to claim 1, wherein the mark is located in part or all of the central region, including a portion facing the body fluid drainage port of the wearer when the article is worn.

3. The absorbent article according to claim 2, wherein the mark is located in at least one of the following areas: a part or all of the front area forward of the central area, and a part or all of the rear area backward of the central area.

4. The side sheet is located on the skin side of the top sheet, and the side sheet has a basis weight of 10 to 30 g / m². ２ The absorbent article according to any one of claims 1 to 3, wherein the absorbent article is at least one of nonwoven fabric and crepe paper.

5. The absorbent article according to any one of claims 1 to 3, wherein the mark includes at least one of a straight line, a wavy line, a dashed line, letters, symbols, a polygon, a circle, an ellipse, a heart shape, a houndstooth pattern, a checkered pattern, a spiral pattern, a dot, and a stripe.

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