Absorbent article

Abstract

This absorbent article comprises 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 comprises: a non-fixed region which includes an absorbent body part disposed directly on the skin side of the back sheet and a liquid-permeable top sheet disposed on the skin side of the absorbent body part, wherein the back sheet and the skin-side structure part are not fixed; and a fixed region which includes a region in which the back sheet and the absorbent body part and / or the top sheet are fixed by an adhesive, wherein the back sheet and the skin-side structure part are not slidable relative to each other. In the non-fixed region, the back sheet and the skin-side structure part are slidable relative to each other. The adhesive has a color that can be visually identified from the skin side and / or the non-skin side.

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 absorber, and a liquid-permeable top sheet are known. However, due to the shrinkage of the underwear and the stress from the groin after being fixed to the underwear, wrinkles and displacement are likely to occur, often causing discomfort.

[0003] As a means for preventing wrinkles 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 body and is fixed to the absorbent body in an extended state. The fixing parts of the elastic stretchable sheet to the absorbent body are respectively formed at positions inward in the width direction from both side edges of the absorber on at least both sides in the longitudinal direction of the absorbent body. An absorbent article is known in which the absorbent body is contracted in the width direction due to the contraction of the elastic stretchable sheet (Patent Document 1).

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

[0005] However, in the absorbent article of Patent Document 1, since it is difficult to know the wearing position where the fit to the skin is good, it is difficult to wear the absorbent article at an appropriate position in the underwear.

[0006] One aspect of the present invention aims to provide an absorbent article that can be worn at a wearing position with good fit to the skin in underwear.

[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, and includes a non-fixed region where the backsheet and the skin-side structure are not fixed, and a fixed region where the backsheet, the absorbent portion and at least one of the top sheet are fixed by an adhesive, and the backsheet and the skin-side structure are not relatively slidable, wherein in the non-fixed region, the backsheet and the skin-side structure are relatively slidable, and the adhesive has a color that is visually distinguishable from at least one of the skin side and the non-skin side.

[0008] According to one embodiment of the present invention, an absorbent article can be provided that can be attached to underwear in a position that provides a good fit to the skin.

[0009] This is a plan view of an absorbent article according to one embodiment of the present invention, as seen from the non-skin side. This is a plan view of an absorbent article according to one embodiment of the present invention, as seen from the skin side. This is a cross-sectional view taken along line I-I in Figure 2. This is a cross-sectional view taken along line II-II in Figure 2. This is a diagram illustrating a part of the manufacturing process of an absorbent article according to one embodiment of the present invention.

[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 Article> Figure 1 is a plan view of an absorbent article according to one embodiment of the present invention, viewed from the non-skin side. Figure 2 is a plan view of the absorbent article according to one embodiment of the present invention, viewed from the skin side. Figure 3 is a cross-sectional view taken along line I-I in Figure 2. Figure 4 is a cross-sectional view taken along line II-II in Figure 2. In the cross-sectional views of Figures 3 and 4, the adhesives that bond the layers together are indicated by reference numerals 10, Ad1, and Ad2. The 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 manufacturing of the absorbent article 1 (described in detail later). In the cross-sectional views of Figures 3 and 4, 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 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 4 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, as shown in Figure 2, is the part that faces the wearer's vaginal opening or other bodily fluid outlet 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 and a sheet positioned on the skin-facing or non-skin-facing side of the back sheet 2. For example, the wings W may be formed by joining the back sheet 2 and the top sheet 3.

[0020] In the example shown in Figure 2, 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 2, 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.

[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 can prevent bodily fluids from leaking from the top sheet.

[0024] 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 soft, air-through nonwoven fabric or a point-bonded nonwoven fabric that is resistant to creasing and wrinkles 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, making them fluffy, soft to the touch, and 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, more preferably 15 to 30 gsm.

[0025] As shown in Figure 3, the absorbent section 4 can be configured to include an absorbent body 4a that substantially absorbs bodily fluids, and a covering sheet 4b that encloses the absorbent body 4a.

[0026] 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.

[0027] 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.

[0028] 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.

[0029] 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.

[0030] 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.

[0031] <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. Figure 3 is also a cross-sectional view including the non-fixed area 9. In Figure 3, the back sheet 2 and the absorbent part 4 are shown separated, but this is illustrated to show 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.

[0032] 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).

[0033] 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).

[0034] 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.

[0035] Furthermore, since the presence or absence of bodily fluid leakage is easily felt by the wearer, especially near the bodily fluid outlet, it is preferable that a non-fixed area 9 that can closely conform to the wearer's skin 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 is formed over the entire central region C, and more preferably that it extends beyond the front and rear ends of the central region C, as shown in Figures 1 and 2.

[0036] 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.

[0037] In the example shown in Figure 2, the non-fixed area 9 may be formed such that the width direction D2 of the absorbent portion 4 includes 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 2, 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. As shown in Figure 3, in the configuration with wings W, it is preferable that the back sheet 2 and the side sheet 7 or top sheet 3 are bonded together with adhesive Ad2.

[0038] Furthermore, as shown in Figure 2, 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 back sheet 2. Also, when the side sheet 7 covers the back sheet 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 allows the side sheet 7 to stretch or deform more easily when the back sheet 2 and the absorbent portion 4 move relative to each other in the width direction. When the side sheet 7 stretches or deforms more easily, the absorbent portion 4 can adhere more closely to the skin in the non-fixed region 9, thereby improving the fit of the absorbent article 1 to the skin. 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.

[0039] Furthermore, the back sheet 2 and the skin-side structure 6 only need to be slidable relative to each other, and the end of the absorbent portion 4 in the width direction D2 and the back sheet 2 may be bonded together along the front-to-back direction D1. In that case, the length of the width direction D2 to which the back sheet 2 and the absorbent portion 4 are bonded together is preferably 0.5 mm or more and 3 mm or less, more preferably 0.5 mm or more and 1 mm or less.

[0040] As described above, the non-fixed area 9 is an area in which the backsheet 2 and the skin-side structure 6 can slide relative to each other, and therefore it is preferable that it is an area having a certain degree of continuous area. For example, the non-fixed area 9 is preferably a continuous area in which the maximum length in the front-to-back direction D1 is 50 mm or more and the maximum length in the width direction D2 is 50 mm or more, and it is more preferable that it is a continuous area in which the maximum length in the front-to-back direction D1 is 60 mm or more and the maximum length in the width direction D2 is 60 mm or more. Furthermore, the non-fixed area 9 may be a continuous area in which the maximum length in the front-to-back direction D1 is greater than or equal to the length in the front-to-back direction D1 of the central area C and the maximum length in the width direction D2 is greater than or equal to the length in the width direction D2 of the absorbent part 4.

[0041] 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 be preferably 15 mm or more, more preferably 20 mm or more, and still more preferably 30 mm or more, although it 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.

[0042] Thus, the non-fixed region 9 is a region where members can slide inside the absorbent article 1, and is a portion that affects the followability to the skin of the skin-side surface of the absorbent article 1, which is likely to deform after wearing.

[0043] <Fixed Region> The absorbent article 1 has a fixed region 8 (shown by oblique lines in FIGS. 1 and 2) including a region where the backsheet 2 and the skin-side structure portion 6 are fixed. In the fixed region 8, the backsheet 2 and the skin-side structure portion 6 are relatively non-slidable. More specifically, the fixed region 8 is a region where the backsheet 2 and at least one of the absorber portion 4 and the topsheet 3 are fixed by an adhesive Ad1 (shown by a matte or gray color in FIGS. 1 and 2). However, when an intermediate sheet 5 is disposed between the backsheet 2 and the topsheet 3, the fixed region 8 may include a region where the backsheet 2 and the intermediate sheet 5 are fixed by the adhesive Ad1.

[0044] In this embodiment, the adhesive Ad1 used to fix the backsheet 2 and the skin-side structural part 6 in the fixing area 8 is such that the presence of the adhesive Ad1 can be identified from at least one of the skin-side and non-skin-side when the user views the absorbent article 1 from any angle. Adhesives commonly used in the art are white, milky white, or transparent, and when the absorbent article is observed using the usual observation method, the presence of the adhesive cannot be identified from its appearance. In contrast, according to this embodiment, the adhesive Ad1 is an adhesive that has a visually distinguishable color. Here, having a visually distinguishable color means that when the absorbent article is observed using the usual observation method, that is, when the user observes the appearance of the absorbent article in the way that the absorbent article is normally viewed when using the absorbent article, its presence can be recognized by the difference in color from adjacent members. Therefore, the color of the adhesive Ad1 may be such that, for example, a difference in brightness can be visually recognized from the color of the members constituting the absorbent article 1. In the examples shown in Figures 1 and 2, the components constituting the absorbent article 1 are white or nearly white, and the adhesive Ad1 forming the fixing area 8 is colored, and is a color that can be recognized as being at least different in brightness from the color of the components constituting the absorbent article 1.

[0045] Furthermore, the color of the adhesive Ad1 may be such that it can be identified by looking through the components constituting the absorbent article 1. For example, in Figure 1, the color of the adhesive Ad1 can be confirmed by looking through the backsheet 2 when viewed from the non-skin side. Therefore, by visually identifying the color of the adhesive Ad1 used in the fixing area 8 when viewed from the non-skin side, the position of the entire fixing area 8 can be recognized. Also, in Figure 2, when viewed from the skin side, the color of the adhesive Ad1 can be confirmed by looking through the components of the skin-side structure 6 other than the absorbent part 4. However, depending on the color of the adhesive Ad1, the material or thickness of the absorbent part 4, the color of the adhesive Ad1 may be identifiable by looking through the absorbent part 4. Therefore, by visually identifying the color of the adhesive Ad1 used in the fixing area 8 when viewed from the skin side, the position of the fixing area 8 in the part where the absorbent part 4 is not present can be recognized. In this way, the wearer can recognize the position of the fixed area 8 of the absorbent article 1 from at least one of the skin-side and non-skin-side, and at the same time be aware of the presence of the non-fixed area 9 and recognize the position and / or extent of the non-fixed area 9. Therefore, in underwear, the absorbent article can be attached to a position that provides a good fit to the skin.

[0046] Figure 4 is a cross-sectional view taken along line II-II in Figure 2, specifically a cross-sectional view of the fixed area 8. In Figure 4, the fixed area 8 is formed by bonding the backsheet 2 and the absorbent portion 4 with adhesive Ad1. Adhesive Ad1 has a color that is visually distinguishable when the absorbent article 1 is viewed from at least one of the skin-side and non-skin-side. Therefore, in Figure 1, when the absorbent article 1 is viewed from the non-skin side, the position of the fixed area 8 can be recognized by visually distinguishing the color of the adhesive Ad1 visible through the backsheet 2. Furthermore, by using adhesive Ad1, the position of the fixed area 8 can be recognized even in areas where the absorbent portion 4 is not present, when the absorbent article 1 is viewed from the skin side. In addition, even if an intermediate sheet 5 exists below the top sheet 3 and the backsheet 2 is bonded to the intermediate sheet 5 with adhesive Ad1, the wearer can recognize the position of the fixed area 8 as long as the color of the adhesive Ad1 is visually distinguishable from the skin-side or non-skin-side. Figure 4 shows a configuration with an intermediate sheet 5. In Figure 4, the back sheet 2 is bonded to the intermediate sheet 5 via adhesive 10 and adhesive Ad1. However, as shown in Figure 2, when the absorbent article 1 is viewed from the skin side, the position of the fixed area 8 where the absorbent portion 4 does not exist can be recognized by identifying the color of adhesive Ad1 through the top sheet 3. Also, when the absorbent article 1 does not have an intermediate sheet 5, the back sheet 2 is directly bonded to the top sheet 3. In that case, when the absorbent article 1 is viewed from the skin side, the position of the fixed area 8 where the absorbent portion 4 does not exist can be recognized by identifying the color of adhesive Ad1. By recognizing the position of the fixed area 8, the wearer can also determine the position of the non-fixed area 9, allowing the absorbent article to be attached to a position in underwear that provides a good fit to the skin.

[0047] Incidentally, even if there is a portion within the fixed region 8 where the backsheet 2 and at least one of the absorber portion 4 and the topsheet 3 are not fixed by an adhesive or the like, if the two are relatively non-slidable, that portion is not included in the "non-fixed region" and becomes the "fixed region". Therefore, as long as the fixed region 8 can be secured, the area of the region to which the adhesive Ad1 is applied may be smaller than the area of the fixed region 8. If the area of the region to which the adhesive Ad1 is applied is smaller than the area of the fixed region 8, the amount of the adhesive Ad1 used for forming the fixed region 8 can be suppressed, so that an increase in the manufacturing cost of the absorbent article 1 can be suppressed.

[0048] Further, the area of the region to which the adhesive Ad1 is applied may be the same as the area of the fixed region 8. When the area of the region to which the adhesive Ad1 is applied is the same as the area of the fixed region 8, the range of the fixed region 8 becomes easier to understand. Also, the fixing by the adhesive in the fixed region 8 can be strengthened.

[0049] Further, in FIG. 4, the absorbent article 1 has a side sheet 7 on the skin side rather than the topsheet 3, and the side sheet 7 is adhered to the topsheet 3 by an adhesive 10. The adhesive 10 that adheres the side sheet 7 and the topsheet 3 in the fixed region 8 preferably has a color that is visually distinguishable from at least one of the skin side and the non-skin side. With such a configuration, it becomes easier for the wearer to visually identify the position of the fixed region 8 from the skin side.

[0050] In the example shown in Figures 1 and 2, the fixed area 8 is formed in both the front area E1 and the rear area E2, but in this embodiment, the location where the fixed area 8 is formed may be either the front area E1 or the rear area E2. The presence of the fixed area 8 on the absorbent article body bd prevents the laminated structure of the absorbent article 1 from breaking even when a large force is applied to the absorbent article 1, thereby improving the robustness of the absorbent article 1. When the fixed area 8 is formed in the front area E1, the length of the fixed area 8 in the front-rear direction D1 from the front end of the front area E1 may be preferably 30% to 80%, more preferably 50% to 70%, of the length of the front-rear direction D1 of the front area E1. Similarly, when the fixed area 8 is formed in the rear area E2, the length of the fixed area 8 in the front-rear direction D1 from the rear end of the rear area E2 may be preferably 30% to 85%, more preferably 40% to 70%, of the length of the front-rear direction D1 of the rear area E2.

[0051] Figure 5 is a diagram illustrating a part of the manufacturing process of an absorbent article according to one embodiment of the present invention. Figure 5 shows a long backsheet strip 2A being transported with its length direction being the transport direction DT, and the state after adhesives Ad1 and Ad2 have been applied. In Figure 5, the configurations to be arranged or formed in subsequent processes are shown by dotted lines. 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 of the fixed area 8 in the final absorbent article 1, is intermittently applied 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 an unfixed area 9 is later formed. Adhesive Ad1 has a color that is visually distinguishable from at least one of the skin side and the non-skin side of the absorbent article after manufacturing. The color of the adhesive Ad1 is not particularly limited as long as it is a color that can be visually distinguished from at least one of the skin-side and non-skin-side, but examples include red, pink, orange, blue, green, yellow, black, gray, brown, etc. However, in this case, the adhesive Ad1 is applied continuously over a range 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. In addition, on the outside of the direction perpendicular to the transport direction DT of the backsheet strip 2A (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. Thus, the absorbent article of the present invention only requires coloring the adhesive used in the fixing area, and does not require increasing the number of materials, making it easy to manufacture and suppressing increases in manufacturing costs. Furthermore, even if there is poor adhesion in the fixed area of ​​the absorbent article of the present invention, changes in the adhesive application area can be easily detected from the appearance of the absorbent article, making it easy to inspect the intermittent position of the fixed area during the manufacturing process. For example, it is easy to detect when a fixed area has not been formed, or when a fixed area has not been formed at a desired location or within a desired range, due to defects in the adhesive coating equipment, etc.

[0052] Adhesive Ad1 and Adhesive Ad2 may be applied as a solid coating, or as dots or lines, in the area shown in Figure 5. For example, they may be linear, curved, spiral, etc., extending along the transport direction DT. Solid coating is preferred from the viewpoint of good visibility of the fixing area from outside the absorbent article. For applying adhesives Ad1 and Ad2, a hot melt coater, more specifically a slot coater, curtain coater, gravure coater, spray coater, spiral gun, bead gun, etc., can be used.

[0053] 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 are overlapped with adhesive as needed, and after heat sealing or the like if necessary, they are cut to obtain the absorbent article 1 (Figures 1, 2, etc.). At this time, in the portion that will become the fixed area 8, the side sheet 7 is bonded to at least one of the skin side and the non-skin side with an adhesive that has a visually distinguishable color, making the position of the fixed area 8 easier to identify visually.

[0054] 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.

[0055] 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. By using the embodiment of the present invention in sanitary napkins, it is possible to wear them in a way that provides a better fit to the skin, and the effects of the present invention can be more fully appreciated.

[0056] 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.

[0057] The specific aspects of this disclosure are further described below.

[0058] (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 top sheet disposed on the skin side of the absorbent portion, and includes a non-fixed region where the backsheet and the skin-side structure are not fixed, and a fixed region where the backsheet, the absorbent portion and at least one of the top sheet are fixed with an adhesive, and the backsheet and the skin-side structure are not relatively slidable, wherein the backsheet and the skin-side structure are relatively slidable in the non-fixed region, and the adhesive has a color that is visually distinguishable from at least one of the skin side and the non-skin side.

[0059] 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.

[0060] 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.

[0061] Furthermore, the absorbent article of this embodiment has a fixed area, which includes a back sheet and at least one of the absorbent portion and the top sheet fixed together with an adhesive, and is an area where the back sheet and the skin-side structure are relatively non-slidable. The adhesive used in the fixed area has a color that is visually distinguishable from at least one of the skin-side and non-skin-side. Therefore, for example, when viewing the absorbent article from the non-skin side, the position of the fixed area can be recognized through the back sheet. Alternatively, when viewing from the skin side, the position of the fixed area where the absorbent portion does not exist can be recognized by identifying the color of the adhesive that bonds the top sheet and the back sheet through the top sheet. As a result, when viewing the absorbent article of this embodiment from at least one of the skin-side and non-skin-side, the fixed area is visually distinguishable by its color, allowing the wearer to recognize the positions of the fixed and non-fixed areas, and to determine the optimal position for a good fit to the skin when attaching the absorbent article to underwear.

[0062] 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.

[0063] Furthermore, in this embodiment, the adhesive used in the fixing area only needs to be colored, and there is no need to increase the number of materials, making it easier to manufacture and suppressing increases in manufacturing costs.

[0064] Furthermore, in this embodiment, even if there is a defect in adhesion in the fixed area, the change in the area to which the adhesive has been applied can be easily detected from the appearance of the absorbent article, making it easy to inspect the intermittent position of the fixed area during the manufacturing process.

[0065] (Note 2) The embodiment of Note 2 is an absorbent article having an intermediate sheet between the top sheet and the absorbent portion, and the area in which the intermediate sheet and the back sheet are fixed by the adhesive is included in the fixing area.

[0066] In the embodiment described in Appendix 2 above, when viewing the absorbent article from the skin side, the position of the fixed area where no absorbent material exists can be recognized by identifying the color of the adhesive bonding the intermediate sheet and the back sheet through the top sheet. Therefore, when viewing the absorbent article from at least one of the skin side and the non-skin side, the fixed area is visually distinguishable by its coloring, allowing the wearer to recognize the positions of the fixed and non-fixed areas.

[0067] (Note 3) The embodiment of Note 3 is an absorbent article in which the area of ​​the region to which the adhesive is applied is smaller than the area of ​​the fixed region.

[0068] According to the embodiment described in Appendix 3 above, the amount of adhesive used in the fixing area can be reduced, thereby suppressing the increase in manufacturing costs.

[0069] (Note 4) The embodiment of Note 4 is an absorbent article having a side sheet on the skin side of the top sheet, wherein in the fixing area, the side sheet is bonded to the top sheet with an adhesive having a color that is visually distinguishable from at least one of the skin side and the non-skin side.

[0070] According to the embodiment described in Appendix 4 above, the position of the fixed area becomes easier to identify visually.

[0071] This application claims priority based on Japanese Patent Application No. 2024-169803, filed on 30 September 2024, the entire contents of which are incorporated herein by reference.

[0072] 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 Ad1 Adhesive Ad2 Adhesive bd Absorbent article body Q Opposite part of body fluid outlet W Wing CL Front-to-back center line D1 Front-to-back direction (longitudinal direction) D2 Lateral direction (short direction) DT Conveying direction

Claims

1. An absorbent article having an impermeable backsheet and a skin-side structural part disposed on the skin side of the backsheet, wherein the skin-side structural part includes an absorbent part directly disposed on the skin side of the backsheet and a permeable top sheet disposed on the skin side of the absorbent part, and having a non-fixed region in which the backsheet and the skin-side structural part are not fixed, and a fixed region in which the backsheet and at least one of the absorbent part and the top sheet are fixed by an adhesive, and the backsheet and the skin-side structural part are not relatively slidable, wherein in the non-fixed region, the backsheet and the skin-side structural part are relatively slidable, and the adhesive has a color that is visually distinguishable from at least one of the skin side and the non-skin side.

2. The absorbent article according to claim 1, wherein an intermediate sheet is provided between the top sheet and the absorbent portion, and the area in which the intermediate sheet and the back sheet are fixed by the adhesive is included in the fixing area.

3. The absorbent article according to claim 1, wherein the area of ​​the region to which the adhesive is applied is smaller than the area of ​​the fixed region.

4. The absorbent article according to any one of claims 1 to 3, wherein the side sheet is located on the skin side of the top sheet, and in the fixing area, the side sheet is bonded to the top sheet with an adhesive having a color that is visually distinguishable from at least one of the skin side and the non-skin side.

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