Absorbent articles

Abstract

To provide an absorbent article that allows users to recognize that wrinkles and misalignment have been prevented after attachment. [Solution] 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 where they are not fixed, the backsheet and the skin-side structure are relatively slidable 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.

Description

Technical Field

[0001] The present invention relates to absorbent articles.

Background Art

[0002] Conventionally, as absorbent articles such as sanitary napkins, panty liners, and incontinence pads, those having a liquid-impermeable back sheet, a liquid-retaining absorbent body, and a liquid-permeable top sheet are known. However, after being fixed to underwear, wrinkles and displacement are likely to occur due to shrinkage of the underwear and stress from the groin, often causing discomfort.

[0003] As a means for preventing wrinkles and displacement and improving the wearing feeling, for example, the wing portions are formed by both end portions of an elastic stretchable sheet that crosses the absorbent main body and is fixed to the absorbent main body in an extended state, and the fixing portions of the elastic stretchable sheet to the absorbent main body are 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, respectively, and an absorbent article in which the absorbent main body is contracted in the width direction by the contraction of the elastic stretchable sheet is known (for example, Patent Document 1).

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

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

[0006] An embodiment of the present invention aims to provide an absorbent article in which it is possible to recognize that wrinkles and displacement are prevented after wearing. [Means for solving the problem]

[0007] A first 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] The absorbent material is used by attaching it 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 material also moves in accordance with the movement of the underwear (including deformation and / or shifting). In this case, even though the absorbent material moves in accordance with the movement of the underwear, the skin in the crotch area to which the skin-facing side of the absorbent material is in contact does not move much, so friction is likely to occur between the skin-facing side (topsheet side) of the absorbent material and the skin in contact with that side. As a result, after the absorbent material is attached, the feeling of wearing it may be impaired due to wrinkles or displacement, and this is especially likely to occur when the absorbent material is worn for a long time or when there is vigorous movement.

[0009] In contrast, the absorbent article according to the first embodiment described above has an unfixed area where the back sheet and the skin-side structure are not fixed, and is configured so that the back sheet and the skin-side structure can slide relative to each other. As a result, one of the opposing back sheets and skin-side structures can move independently along the surface relative to the other. Therefore, even if the back sheet 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 back sheet 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 back sheet 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.

[0010] 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.

[0011] 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.

[0012] 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.

[0013] A second aspect of the present invention is an absorbent article in which the mark is located in part or all of the central region, including a portion facing the body fluid outlet of the wearer when the article is worn.

[0014] 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 second embodiment described 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.

[0015] A third aspect of the present invention 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 forward of the central area, and a part or all of the rear area backward of the central area.

[0016] According to the third embodiment described 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.

[0017] A fourth aspect of the present invention is a side sheet located on the skin side of the top sheet, wherein 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.

[0018] According to the fourth aspect described above, the side sheet can suppress the leakage of body fluid in the width direction from the top sheet. When viewed from the skin side, when the side sheet covers the mark on the back sheet, the side sheet is at least one of non-woven fabric and crepe paper, and the basis weight is 10 to 30 g / m 2 If it is within the range, even if the back sheet and the absorber part move relatively in the width direction, at least when viewed from the skin side, the deformation, appearance, or disappearance of the mark can be identified through the side sheet.

[0019] A fifth aspect of the present invention is an absorbent article in which the mark includes at least one of a straight line, a wavy line, a broken line, characters, symbols, polygons, circles, ellipses, heart shapes, zigzag patterns, check patterns, spiral patterns, dots, and stripes.

[0020] According to the fifth aspect described above, since various designs can be selected as the mark, an absorbent article rich in both functionality and designability can be obtained.

Advantages of the Invention

[0021] According to an embodiment of the present invention, it is possible to provide an absorbent article that can recognize that sagging and displacement are prevented after wearing.

Brief Description of the Drawings

[0022] [Figure 1] It is a schematic plan view of an example of an absorbent article according to an embodiment of the present invention as viewed from the skin side. [Figure 2] It is a schematic plan view of an example of an absorbent article according to an embodiment of the present invention as viewed from the non-skin side. [Figure 3] It is a cross-sectional view taken along line I-I of FIG. 1. [Figure 4] It is a schematic view of the shape before and after deformation of an example of an absorbent article according to an embodiment of the present invention as viewed from the skin side. [Figure 5] It is an enlarged schematic view of the marks M located in the regions F1 and F2 of the absorbent article in FIG. 4. [Figure 6]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. [Figure 7A] These are several examples of marks used on absorbent articles according to one embodiment of the present invention. [Figure 7B] This figure shows how the marks on the backsheet of an absorbent product, which has some examples of the marks shown in Figure 7A, appear to be visible from the skin side before and after use. [Modes for carrying out the invention]

[0023] The 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.

[0024] 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.

[0025] (Analytical items) 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 II of Figure 1. In the cross-sectional view of Figure 3, the adhesive that bonds the layers together is shown as adhesive 10. That is, the adhesive 10 in the cross-sectional view of Figure 3 joins or fixes the two members sandwiching the adhesive 10 to each other. Two laminated members without adhesive 10 interposed are in direct contact or can be in direct contact, but are not joined or fixed to each other.

[0026] 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.

[0027] 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 a 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.

[0028] 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.

[0029] 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-to-back 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).

[0030] 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 preferably 0.3 mm or more and 30 mm or less, more preferably 1.0 mm or more and 15 mm or less, when measured at a location other than the compressed area in the thickness direction. However, the absorbent article body bd may have a configuration in which the absorbent part 4 is partially bulged by bulging a part of the absorbent part 4, for example, the area opposite the body fluid outlet Q and the area near it, and the center of the width direction D2 of the rear area.

[0031] In addition, 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 edge 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.

[0032] 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.

[0033] 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 positioned 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 positioned 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 in Figure 1, for convenience, the mark M 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.

[0034] <Non-fixed area> As shown in Figure 1, in the absorbent article 1 according to one embodiment of the present invention, the absorbent article body bd has an unfixed region 9 in which the back sheet 2 and the skin-side structural part 6 directly positioned 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.

[0035] 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).

[0036] 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 backsheet 2, the skin-side structure 6 can conform well to the wearer's skin while remaining in close contact with it (high conformability to the skin is achieved). After the skin-side structure 6 conforms to the skin, the wearer can identify the deformation, appearance, or disappearance of the mark M on the backsheet 2 when viewed from the skin side.

[0037] 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.

[0038] 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 Figure 1.

[0039] The area of ​​the non-fixed area 9 in the overlapping region between the backsheet 2 and the absorbent portion 4, that is, the area of ​​the non-fixed area 9 relative to the area of ​​the absorbent portion 4, is preferably 50% or more, more preferably 70% or more. Having the non-fixed area 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 area 9 in the absorbent article body bd, that is, the area of ​​the non-fixed area 9 relative to the area of ​​the absorbent article body bd, is also preferably 50% or more, more preferably 70% or more.

[0040] In the example shown in Figure 1, the non-fixed area 9 is formed to include the entire range where the width direction D2 of the absorbent portion 4 is longest, and 70% or more of the area of ​​the absorbent portion 4 is 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-following ability of the skin-facing side of the absorbent article 1 to conform 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. The non-fixed area 9 may also 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.

[0041] 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, thereby improving the skin-side structural portion 6's conformity to the skin. The length k in the width direction D2 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 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.

[0042] Furthermore, the back sheet 2 and the skin-side structure 6 only need to be relatively slidable, and the end of the absorbent part 4 in the width direction D2 and the back sheet 2 may be bonded 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 part 4 are bonded is preferably 0.5 mm or more and 3 mm or less, more preferably 0.5 mm or more and 1 mm or less.

[0043] 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.

[0044] Furthermore, in this embodiment, when the backsheet 2 and the skin-side structure 6 are pulled in opposite directions in the width direction D2, the relative distance d1 between the backsheet 2 and the skin-side structure 6 in the width direction D2 may be 10 mm or more. This distance d1 depends on the overall size of the absorbent article 1, but is preferably 15 mm or more, more preferably 20 mm or more, and even more preferably 30 mm or more. The above distance d1 may be the distance measured by the force applied when the absorbent article is handled in a normal manner.

[0045] Thus, the non-fixed area 9 is an area within the absorbent article 1 where the components can slide against each other, and is prone to deformation after application, affecting the conformability of the skin-facing surface of the absorbent article 1 to the skin.

[0046] <mark> 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.

[0047] Furthermore, in Figure 2, mark M is located 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. By positioning mark M in these regions, even if the absorbent article 1 is attached to the underwear in such a way that the part opposite the bodily fluid drainage port Q protrudes into the front region E1 or the rear region E2, mark M can be positioned near the part opposite the bodily fluid drainage port Q, which is a region that is easily deformed. The wearer can recognize that wrinkles and displacement of the absorbent article after attachment have been prevented by identifying the deformation, appearance, or disappearance of mark M.

[0048] 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 be located within the non-fixed area 9, which is an area where the absorbent part 4 is easily deformed. Furthermore, since it is easier to check for misalignment between the absorbent part 4 and the backsheet 2 when viewed from the skin side, it is more preferable that it be located in an area 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. Mark M only needs to be visible from the skin side and may be on either the non-skin side or the skin side of the backsheet 2.

[0049] 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 singular 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. Furthermore, one of the elements constituting the mark M may be referred to as a "mark". For example, in the example in Figure 2, two marks M are formed by four lines, but since the elements constituting each mark M are one line, the mark 11 in the mark M is one line. Note that if there is only one mark 11 in one mark M, the mark 11 can be considered as the mark M.

[0050] Figure 7A shows several examples of marks used in an absorbent article according to one embodiment of the present invention. Figure 7B shows how the marks appear from the skin side before and after use of an absorbent article having some of the marks shown in Figure 7A on the backsheet. In Figure 7B, below each mark M, an example of how the mark M appears 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 slides in the direction of the arrow as it adheres to the skin. 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 mark M, the wearer of the absorbent article can recognize that wrinkles and displacement have been prevented after wearing the absorbent article.

[0051] Figure 4 is a schematic diagram showing the shape of an absorbent article according to one embodiment of the present invention, before and after deformation, as viewed from the skin side, and is an example where the position of mark M on the back sheet 2 is different from that of Figure 2. Figure 4(a) is the shape of the absorbent article 1 before deformation, and Figure 4(b) is the shape of the absorbent article 1 after deformation. Figure 5 is a schematic diagram of enlarged views of the marks M located in regions F1 and F2 of the absorbent article in Figure 4. Figure 5(a) is an enlarged view of region F1 in Figure 4(a), and Figure 5(b) is an enlarged view of region F2 in Figure 4(b). The absorbent article 1 in Figure 4 has four lines that become marks 11 as marks M on the back sheet as viewed from the non-skin side, but in Figures 4 and 5, the lines of marks 11 visible from the skin side before and after deformation are shown as marks M. 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 is faintly visible through the sheet on top of the backsheet, and in region F1, three lines are visible as the mark M (Figure 4(a), Figure 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 lines are visible as the mark M (Figure 4(b), Figure 5(b)). In addition, in the mark M 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 been deformed (Figure 4(b)). Furthermore, in the mark M on the right side when viewed from the skin side, some of 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 disappeared, and the lines of the mark M visible from the skin side have been deformed (Figure 4(b)). Thus, after wearing the absorbent article of the present invention, the back sheet and the skin-side structure slide relative to each other, and as the skin-side structure conforms to the skin and deforms, the wearer can identify that the mark M on the back sheet deforms, appears, or disappears.

[0052] As the backsheet 2, a sheet material having at least water-impermeable properties, such as an olefin resin sheet of polyethylene or polypropylene, can be used. Laminated nonwoven fabrics obtained by laminating a nonwoven fabric onto a polyethylene sheet, or even laminated nonwoven fabric sheets with a waterproof film interposed to ensure substantially liquid impermeability, can be used. Furthermore, from the viewpoint of preventing stuffiness, it is even more preferable to use a material that has moisture permeability. 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.

[0053] 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 15-50 gsm (g / m²). 2 It is preferable that the strength be 15-30 gsm, and more preferably 15-30 gsm.

[0054] 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 15-30 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 may be made of nonwoven fabric, crepe paper, etc., with a basis weight of 10-30 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.

[0055] 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 beneath 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.

[0056] 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 grain size be 15 to 50 gsm, more preferably 15 to 30 gsm, and even more preferably 15 to 30 gsm.

[0057] 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.

[0058] 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 due to their long fiber length. The absorbent body 4a can be manufactured by the fiber stacking or airlaid method. Alternatively, a thin sheet, so-called SAP sheet, can be used as the absorbent body 4a, which consists of a layer of superabsorbent polymer granules and / or superabsorbent polymer fibers sandwiched between sheets of nonwoven fabric or the like. When an SAP sheet is used, the covering sheet 4b can be omitted.

[0059] 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 (with a high melting point fiber as the core and a low melting point fiber as the sheath), side-by-side fibers, and split fibers can also be used. Furthermore, hydrophobic fibers can be surface-treated with a hydrophilizing agent to impart affinity to body fluids.

[0060] The structure in which the absorbent body 4a is encased in a 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.

[0061] 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 part 4, and consequently friction between the back sheet 2 and the skin-side structure part 6 on the skin side of the back sheet 2, an air-through nonwoven fabric is preferred.

[0062] Furthermore, an intermediate sheet may be provided between the top sheet 3 and the absorbent section 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 may be the same as the material of the top sheet 3 described above.

[0063] <Fixed area> The absorbent article 1 may include a fixed area 8, other than the non-fixed area 9, in which the back sheet 2 and at least one of the absorbent portion 4 and the top sheet 3 are fixed by an adhesive or other adhesive means. In the example shown in Figures 1 and 2, the fixed area 8 is formed by fixing the back sheet 2 and at least one of the absorbent portion 4 and the top sheet 3 in the front area E1 and the rear area E2, respectively.

[0064] In this embodiment, the location where the fixed area 8 is formed may be either the front area E1 or the rear area E2. Furthermore, the absorbent article 1 can be configured such that the fixed area 8 is not formed, i.e., the non-fixed area 9 is formed across the entire absorbent article body bd. In the configuration where the fixed area 8 is not formed across the entire body, the backsheet 2 and the skin-side structure 6 can slide more easily (with less force) over a wider area, which is preferable in that it improves the skin-following ability of the skin-side structure 6 to the skin. On the other hand, the configuration in which the fixed area 8 is present on the absorbent article body bd is preferable in that it 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. Furthermore, even when the fixed region 8 is formed in the rear region E2, the length D1 in the front-rear direction from the rear end of the rear region E2 may be preferably 30% to 85%, more preferably 40% to 70%, of the length D1 of the rear region E2 in the front-rear direction.

[0065] 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".

[0066] 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. The mark M is preferably printed in the area that will become the non-fixed area 9, more preferably on the area that overlaps with the absorbent part 4, and even more preferably within 5 mm from the widthwise end of the absorbent part 4 toward the front-to-back centerline CL. 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 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 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. Thus, 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.

[0067] 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.

[0068] After applying the adhesive, the absorbent section 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.).

[0069] The absorbent item 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 backsheet 2 to be more securely fixed to the underwear, making it easier for the backsheet 2 and the skin-side structure 6 to slide relative to each other, thus improving the wearing comfort.

[0070] 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.

[0071] 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. [Explanation of Symbols]

[0072] 1. Absorbent articles 2 back seats 2A Backseat Band 3 Top Sheet 4 Absorbent part 4a Absorbent body 4b Packaging sheet 5 Intermediate seats 6 Skin side structure 7 Side Seats 8 Fixed area 9 Non-fixed area 10 Adhesives 11 marks Ad1 Adhesive Ad2 Adhesive bd Absorbent Article Body Q Opposite body fluid outlet W Wing M mark CL Anteroposterior center line D1 Front-to-back direction (longitudinal direction) D2 width direction (horizontal direction) DT transport direction

Claims

1. An absorbent article having an impermeable backsheet and a skin-side structure disposed on the skin side of the backsheet, The skin-side structure includes an absorbent portion directly positioned on the skin side of the back sheet and a permeable top sheet positioned on the skin side of the absorbent portion. The back sheet and the skin-side structural part have an unfixed area where they are not fixed. In the non-fixed region, the back sheet and the skin-side structure are slidable relative to each other. An absorbent article wherein, when the back sheet and the absorbent portion move relative to each other in the width direction, the back sheet has marks that can be identified as deformed, appearing, or disappearing, 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, which is opposite 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. The aforementioned side sheets have 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.

Images