Absorbent articles

Abstract

Even when using a highly absorbent sheet as the absorbent core, it is possible to prevent shifting or bunching after urination, providing an absorbent item that remains comfortable to wear even after urination. [Solution] The present disclosure relates to an absorbent article 10 comprising a top sheet, a back sheet 12, an absorbent 13, and an adhesive layer 14, wherein the absorbent 13 does not contain fluff pulp, the maximum length L3 in the longitudinal direction of the adhesive layer 14 is 100% or more and 130% or less when the length L2 in the longitudinal direction of the absorbent 13 is taken as 100%, and when the adhesive layer 14 is divided into three equal parts in the longitudinal direction, a first region 19, a second region 20, and a third region 21 from one side in the longitudinal direction, the maximum length W3a in the width direction of the first region 19 and the maximum length W3c in the width direction of the third region 21 are 100% or more and 130% or less when the length W2 in the width direction of the absorbent 13 is taken as 100%, and the maximum length W3b in the width direction of the second region 20 is 60% or more and 80% or less when the length W2 in the width direction of the absorbent 13 is taken as 100%.

Description

[Technical Field]

[0001] This disclosure relates to absorbent articles. [Background technology]

[0002] Patent Document 1 discloses an absorbent article in which an absorbent material is interposed between an impermeable back sheet and a permeable surface sheet. The absorbent material is composed of fluff pulp and a superabsorbent polymer. The underwear-contacting surface of the impermeable back sheet has adhesive anti-slip means in a predetermined pattern. The adhesive anti-slip means consists of a number of linear adhesive layers formed along the short direction of the absorbent article at intervals in the longitudinal direction of the absorbent article. The adhesive pattern with the shortest length in the short direction is arranged in the crotch area including the bodily fluid drainage area, the adhesive pattern with the longest length in the short direction is arranged in the front and rear end areas of the absorbent article, and the adhesive pattern with an intermediate length in the short direction is arranged in the intermediate area between the crotch area and the front and rear end areas. This prevents the entire absorbent article from shifting position, and in particular prevents shifting position and the occurrence of vertical wrinkles in the absorbent material portion that contributes to absorption in the crotch area. [Prior art documents] [Patent Documents]

[0003] [Patent Document 1] Japanese Patent Publication No. 2003-010245 [Overview of the project] [Problems that the invention aims to solve]

[0004] Incidentally, in light incontinence products, there is a demand for thin, absorbent items that offer superior comfort, such as feeling like you're not wearing anything at all. While absorbent materials for absorbent items have traditionally consisted of fluff pulp and superabsorbent polymers, there is a growing trend towards thin, superabsorbent sheets made of nonwoven fabric and superabsorbent polymers. Absorbent items using superabsorbent sheets offer good comfort before urination, but a challenge is that the absorbent material swells upon urination, significantly increasing the thickness of the absorbent item, worsening comfort, and causing shifting and bunching. This problem is particularly pronounced in products with large stated absorption capacities and long product lengths.

[0005] The absorbent article described in Patent Document 1 does not prevent deterioration of wearing comfort, shifting, or bunching when a thin, highly absorbent sheet swells due to urination. Furthermore, although numerous linear adhesive layers are formed along the shorter side, if there are many linear adhesive layers, the hot melt adhesive is more likely to break when peeled off the underwear, and adhesive residue is more likely to remain on the underwear.

[0006] Therefore, this disclosure aims to provide an absorbent article that, even when using a highly absorbent sheet as the absorbent material, can prevent shifting or bunching after urination, and satisfies high standards in terms of adhesive strength to underwear, minimal transfer of the adhesive layer to underwear (residue), and comfort after urination. [Means for solving the problem]

[0007] To solve the above problems, a first aspect of the present invention provides an absorbent article comprising: a liquid-permeable top sheet on the skin side; a liquid-impermeable back sheet on the non-skin side; an absorbent disposed between the top sheet and the back sheet; and an adhesive layer provided on the non-skin side of the back sheet, wherein the absorbent does not contain fluff pulp, the maximum length of the adhesive layer in the longitudinal direction is 100% or more and 130% or less when the length of the absorbent in the longitudinal direction is taken as 100%, and when the adhesive layer is divided into three equal parts in the longitudinal direction by an imaginary line extending in the width direction, and these are designated as a first region, a second region, and a third region from one side in the longitudinal direction, the maximum length in the width direction of the first region and the maximum length in the width direction of the third region are 100% or more and 130% or less when the length of the absorbent in the width direction is taken as 100%, and the maximum length in the width direction of the second region is 60% or more and 80% or less when the length of the absorbent in the width direction is taken as 100%.

[0008] A second aspect of the present invention is an absorbent article according to the first aspect, wherein the absorbent is a highly absorbent sheet having a nonwoven fabric sheet and a highly absorbent polymer, the shape of the absorbent is rectangular, and the shape of the absorbent article is such that the central part in the longitudinal direction is constricted inward in the width direction.

[0009] A third aspect of the present invention is an absorbent article according to the second aspect, wherein the basis weight of the superabsorbent polymer in the absorbent is 400 g / m². 2 More than 1000g / m 2 The following applies:

[0010] A fourth aspect of the present invention is an absorbent article according to the first or second aspect, wherein the absorbent article has a concentration of 35 g / cm³. 2 The thickness under load is 4.5 mm or less, and the thickness of the absorbent article after 40 ml of physiological saline solution is added to the absorbent material is between 2 and 3.5 times the thickness before adding the saline solution.

[0011] A fifth aspect of the present invention is an absorbent article according to the first or second aspect, wherein the adhesive layer is a layer of adhesive applied to the non-skin side of the back sheet, the amount of adhesive applied is 20 gsm or more and 60 gsm or less, and the adhesive layer consists of 3 to 6 continuous straight lines and 4 short straight lines arranged on all four sides. [Effects of the Invention]

[0012] According to this disclosure, even when using a highly absorbent sheet as the absorbent material, it is possible to prevent shifting or bunching after urination, and to provide an absorbent article that satisfies high standards in terms of adhesive strength to underwear, minimal transfer of the adhesive layer to underwear (residue), and comfort after urination. [Brief explanation of the drawing]

[0013] [Figure 1] This is a plan view from the skin side of an absorbent article and an individual packaging sheet according to one embodiment of the present invention. [Figure 2] This is a cross-sectional view taken along the line II-II in Figure 1. [Figure 3] This is a plan view of an absorbent material from the non-skin side. [Modes for carrying out the invention]

[0014] The following describes an absorbent article according to one embodiment of the present invention, with reference to the drawings.

[0015] In this specification, the wearing of an absorbent article means the state in which the absorbent article is worn on the body, regardless of before, during, and after the absorption of body fluids. Also, the "left - right direction" refers to the left - right direction as viewed from the wearer in a state facing forward. The "longitudinal direction" means the longitudinal direction of the absorbent article, which is the direction along the front - back of the wearer when worn, and is the direction along the arrow X in the figure. The inner side of the longitudinal direction is the direction toward the center of the longitudinal direction, and the outer side of the longitudinal direction is the direction away from the center of the longitudinal direction. The "width direction" means the direction intersecting (orthogonal) with the longitudinal direction, which is the direction along the left - right of the wearer when worn, and is the direction along the arrow Y in the figure. The inner side of the width direction is the direction toward the center of the width direction, and the outer side of the width direction is the direction away from the center of the width direction. The "thickness direction" refers to the direction in which each component member is laminated, which is the direction intersecting (orthogonal) with both the longitudinal direction and the width direction, and is the direction along the arrow Z in the figure. The "skin - side" means the direction toward the body of the wearer when the absorbent article is worn in the thickness direction, and the "non - skin - side" means the direction opposite to the skin - side in the thickness direction. Also, body fluids refer to liquids discharged from the body to the outside, such as urine, blood, and moisture in soft stools.

[0016] (Absorbent article) FIG. 1 is a plan view from the skin - side of an absorbent article and an individual packaging sheet according to an embodiment of the present invention. FIG. 2 is a cross - sectional view taken along the arrow II - II in FIG. 1. FIG. 3 is a plan view from the non - skin - side of the absorbent article. In FIG. 2, a schematic cross - section of the absorbent article is illustrated.

[0017] [[ID=I0]]The absorbent article 10 according to this embodiment can be used as various absorbent articles regardless of being for adults, and typically includes light incontinence pads, urine absorbent pads, sanitary products, and the like.

[0018] As shown in FIGS. 1 to 3, the absorbent article 10 includes a liquid-permeable topsheet 11 on the skin side, a liquid-impermeable backsheet 12 on the non-skin side, an absorber 13 disposed between the topsheet 11 and the backsheet 12, and an adhesive layer 14 provided on the non-skin side surface of the backsheet. Further, the absorb the absorbent article 10 of the present embodiment further includes three-dimensional gathers 15 on the left and right in addition to these. Further, the absorbent article 10 of the present embodiment includes an individual packaging sheet 16 that can protect the adhesive layer 14. Note that the absorbent article 10 may not have the three-dimensional gathers 15 on the left and right. Further, the absorbent article 10 may include other configurations (for example, a transfer sheet disposed between the topsheet 11 and the absorber 13).

[0019] (Shape) The shape of the absorbent article 10 is not particularly limited, but from the viewpoint of wearing comfort, it is preferably a shape (hourglass shape) in which the central portion in the longitudinal direction is constricted inward in the width direction. Note that the shape of the absorbent article 10 may be a rectangular shape, a oval shape, or the like.

[0020] (Dimensions of Absorbent Article) The length (maximum length) L1 of the absorbent article 10 in the longitudinal direction is preferably 150 mm or more and 500 mm or less. If the length L1 of the absorbent article 10 in the longitudinal direction is less than 150 mm, it will be short enough to fit in the crotch portion of the underwear. Therefore, when the width of the adhesive layer 14 in the front and rear portions is widened, the adhesive layer 14 may stick to the skin, and it is difficult to widen the width of the adhesive layer 14 in the front and rear portions. On the other hand, if the length L1 of the absorbent article 10 in the longitudinal direction is greater than 500 mm, it is likely to sag during use. Note that the lower limit value of the length L1 of the absorbent article 10 in the longitudinal direction is more preferably 250 mm or more. Further, the upper limit value of the length L1 of the absorbent article 10 in the longitudinal direction is more preferably 400 mm or less.

[0021] The widthwise length (maximum length) W1 of the absorbent article 10 is preferably 60 mm or more and 180 mm or less. If the widthwise length W1 of the absorbent article 10 is less than 60 mm, the width of the absorbent body 13 cannot be sufficiently secured, and leakage of liquid from the absorbent article 10 may occur during urination. On the other hand, if the widthwise length W1 of the absorbent article 10 is greater than 180 mm, the absorbent article 10 may not fit sufficiently inside the underwear, or it may become uncomfortable to wear and the wearing experience may be poor.

[0022] (Top sheet) The top sheet 11 is a liquid-permeable sheet-like substrate that allows bodily fluids to pass rapidly towards the absorbent material 13 and diffuse them in the planar direction of the absorbent material 13. The top sheet 11 is a sheet that is located on the skin side when worn, and is positioned opposite the back sheet 12, sandwiching the absorbent material 13. The top sheet 11 is preferably made of a soft, non-irritating substrate so that it can come into direct contact with the wearer's skin. Examples of substrates include hydrophilic sheets, composite nonwoven fabrics which are laminates of the same or different types of hydrophilic sheets, open films such as open polyethylene films, and foamed films such as polyethylene foam and urethane foam. Examples of hydrophilic sheets include air-through nonwoven fabrics, thermal-bonded nonwoven fabrics, spunlace nonwoven fabrics, and spunbond nonwoven fabrics made using one or more types of synthetic fibers such as polypropylene, polyethylene, polyester, regenerated fibers such as rayon, and natural fibers such as cotton. Among these, air-through nonwoven fabric is preferred as the top sheet 11.

[0023] The top sheet 11 may contain lotion, antioxidants, anti-inflammatory ingredients, pH adjusters, antibacterial agents, moisturizers, etc., to reduce skin irritation. The shape of the top sheet 11 is not particularly limited, and it is sufficient if it is large enough to guide bodily fluids to the absorbent 13 without leakage and covers part or all of the absorbent 13.

[0024] Furthermore, the device may include sheets placed between the top sheet 11 and the absorbent 13, and sheets placed between the absorbent 13 and the back sheet 12. These sheets may be made of the same material as the top sheet 11, or they may be hydrophilic sheets made of pulp fibers such as tissue.

[0025] (Back seat) The back sheet 12 is a sheet that is positioned on the non-skin side when worn. The back sheet 12 only needs to be formed using a base material that is impermeable to liquid so that the bodily fluids held by the absorbent 13 do not wet the wearer's clothing. Examples of such base materials include resin films and composite sheets which are laminates of resin films and nonwoven fabrics. The nonwoven fabric used in the composite sheet is not particularly limited in its manufacturing method and includes, for example, single-layer nonwoven fabrics such as spunbond nonwoven fabrics and meltblown nonwoven fabrics, composite nonwoven fabrics such as spunbond nonwoven fabric / meltblown nonwoven fabric laminates and spunbond nonwoven fabric / meltblown nonwoven fabric / spunbond nonwoven fabric laminates, and composite materials thereof. Examples of resin films include polyester, polyvinyl alcohol, polyethylene, polypropylene, and composite films of polyethylene and polypropylene.

[0026] The back sheet 12 is preferably made breathable to prevent stuffiness during wear. To make the back sheet 12 breathable, for example, a filler can be compounded into the base resin film, or the back sheet 12 can be embossed. Calcium carbonate can be used as a filler, and the compounding method can be any known method without limitation.

[0027] (Absorbent) As shown in Figure 2, the absorbent 13 is a component that primarily absorbs and retains bodily fluids, and does not contain fluff pulp. For example, the absorbent 13 in this embodiment is a highly absorbent sheet having a hydrophilic nonwoven fabric sheet 17 as a base material and a highly absorbent polymer 18 (hereinafter referred to as "SAP18") held on the nonwoven fabric sheet 17.

[0028] Examples of SAP18 include polyacrylates, polyaspartates, (starch-acrylic acid) graft copolymers, (acrylic acid-vinyl alcohol) copolymers, (isobutylene-maleic anhydride) copolymers, and their saponified products. Among these, from the viewpoint of absorption per unit weight, polyacrylates are preferred, alkali metal polyacrylates are more preferred, and sodium polyacrylate is even more preferred. SAP18 can be used individually or in combination of two or more types.

[0029] SAP can be used in various forms, such as particulate or fibrous, but is preferably used in particulate form from the viewpoint of ease of handling. In this case, by avoiding the use of fine powder SAP, which has poor fluidity as a powder, and using SAP with a medium particle size, the basic performance regarding absorption can be improved, and the rough texture caused by the hardening of the absorbent 13 can be reduced.

[0030] The basis weight of the SAP18 absorbent material 13 is 400 g / m². 2 More than 1000g / m 2 The following is preferable: SAP18 basis weight of 400 g / m² 2 If the size is made smaller than this, it becomes difficult to ensure sufficient rigidity of the absorbent material 10, making it prone to shifting and twisting, and potentially resulting in insufficient absorption and leakage after urination. On the other hand, if the basis weight of SAP18 is 1000g / m² 2 Making it larger than this could lead to greater deformation due to water absorption after urination, potentially increasing discomfort while wearing it.

[0031] Although Figure 2 illustrates a state in which SAP 18 is fixedly supported between a pair of nonwoven fabric sheets 17, the diagram is not limited to this. For example, three or more nonwoven fabric sheets 17 may be laminated and SAP 18 fixedly supported between each nonwoven fabric sheet 17, or one side of a single nonwoven fabric sheet 17 may be made napped and SAP 18 fixedly supported between its fibers.

[0032] The shape of the absorbent 13 is not particularly limited, but it is preferably rectangular, as shown in Figures 1 and 3. However, the shape of the absorbent 13 is not limited to rectangular, and may be, for example, oval or hourglass-shaped.

[0033] (Dimensions of the absorbent material) The widthwise length (maximum length) W2 of the absorbent material 13 is preferably 45 mm or more and 80 mm or less. If the widthwise length W2 of the absorbent material 13 is less than 45 mm, there is a possibility that leakage of liquid from the absorbent item 10 may occur during urination. On the other hand, if the widthwise length W2 of the absorbent material 13 is greater than 80 mm, the widthwise length W1 of the absorbent item 10 will increase accordingly, making it difficult for the absorbent item 10 to fit sufficiently inside the underwear, and potentially resulting in poor comfort and a less pleasant wearing experience.

[0034] The longitudinal length (maximum length) L2 of the absorbent material 13 is preferably 130 mm or more and 360 mm or less. If the longitudinal length L2 of the absorbent material 13 is less than 130 mm, the length of the absorbent article 10 will also be short enough to fit in the crotch area of ​​the underwear, and if the width of the adhesive layer 14 on the front and back is widened, the adhesive layer 14 may stick to the skin, making it difficult to widen the width of the adhesive layer 14 on the front and back. On the other hand, if the longitudinal length L2 of the absorbent material 13 is greater than 360 mm, it is prone to wrinkles during use.

[0035] (Three-dimensional gathers) As shown in Figures 1 and 2, the left and right three-dimensional gathers 15 are members for preventing leakage of bodily fluids outward in the width direction, and are arranged to extend longitudinally on both sides of the skin-facing side of the top sheet 11 in the width direction. The left and right three-dimensional gathers 15 have a water-repellent and / or waterproof gather sheet 15a and are able to stand upright from the base end supported on the top sheet 11 side toward the tip (free end) side. It is preferable to provide an elastic stretch member 15b, such as elastic thread, along the longitudinal direction on the tip side of the left and right three-dimensional gathers 15. Providing the elastic stretch member 15b makes it easier to stand upright.

[0036] (Gathered sheet) The gathered sheet 15a is a water-repellent and / or waterproof sheet, and is made of, for example, a nonwoven fabric. Any nonwoven fabric formed from hydrophobic fibers that is water-repellent and / or waterproof (liquid-impermeable) can be used for the gathered sheet 15a without particular limitation. Examples include spunbond nonwoven fabrics, meltblown nonwoven fabrics, and composite nonwoven fabrics (SMS nonwoven fabrics) which are laminates of spunbond nonwoven fabrics / meltblown nonwoven fabrics / spunbond nonwoven fabrics.

[0037] (Elastic stretchable material) The elastic stretchable member 15b is arranged along the longitudinal direction near the tip of the gathered sheet 15a, providing uprightness to the tip side and allowing the tip of the gathered sheet 15a and the surrounding area to be deformed to fit the wearer's body shape. As the elastic stretchable member 15b, thread-like, string-like, or strip-like materials made of natural rubber, synthetic rubber, polyurethane, etc., can be used as appropriate.

[0038] (Adhesive layer) As shown in Figures 2 and 3, the adhesive layer 14 is provided on the non-skin side of the backsheet 12 for attaching the absorbent article 10 to the wearer's underwear, etc. Known materials can be used for the adhesive constituting the adhesive layer 14. In this embodiment, the adhesive layer 14 is formed by applying a hot-melt adhesive as an adhesive to the non-skin side of the backsheet 12. That is, the adhesive layer 14 is a layer of adhesive applied to the non-skin side of the backsheet 12.

[0039] The amount of adhesive applied is preferably between 20 gsm and 60 gsm. If the amount of adhesive applied is less than 20 gsm, the adhesive strength of the adhesive layer 14 will be insufficient, making it easier for the absorbent article 10 to shift when worn. On the other hand, if the amount of adhesive applied is more than 60 gsm, adhesive residue is more likely to occur when the absorbent article 10 is peeled off the underwear after use.

[0040] The amount of adhesive applied can be measured using the following method. First, the backsheet 12 is removed from the absorbent article 10, and the weight of the removed backsheet 12 (including the adhesive layer 14) is measured. Next, the area of ​​the adhesive layer 14 is measured using a JIS-compliant metal ruler or similar. Then, the adhesive (hot melt adhesive) of the adhesive layer 14 is wiped off the backsheet 12 with a nonwoven fabric soaked in an organic solvent, and completely removed from the backsheet 12. Finally, after air drying, the weight of the backsheet 12 is measured again, and the difference between this weight and the weight before removal of the adhesive layer 14 is calculated as the amount of adhesive applied (basis weight). The measurement is performed five times, and the average of these measurements is used as the measured value. The weight measurement and air drying are performed in an environment of 23°C and 50% RH.

[0041] The adhesive layer 14 preferably consists of 3 to 6 continuous straight lines and 4 short straight lines arranged on all four sides. The adhesive layer 14 of this embodiment is composed of a plurality of adhesive layers (8 adhesive layers 14a to 14h in this embodiment) extending in the longitudinal direction. Four of the plurality of adhesive layers 14a to 14d are arranged symmetrically on the inside in the width direction of the absorbent article 10 and extend linearly in a long length in the longitudinal direction. That is, the four adhesive layers 14a to 14d are adhesive layers 14 of 3 to 6 (4 in this embodiment) continuous straight lines. The longitudinal lengths of the four adhesive layers 14a to 14d of this embodiment are set to be approximately the same. Two of the plurality of adhesive layers 14e and 14f are arranged symmetrically on both sides in the width direction of one end of the longitudinal direction of the four adhesive layers 14a to 14d and extend linearly in a short length in the longitudinal direction. Of the multiple adhesive layers, two adhesive layers 14g and 14h are arranged symmetrically on both sides of the width direction at the other ends in the longitudinal direction of the four adhesive layers 14a to 14d, and extend in a short, linear manner in the longitudinal direction. In other words, the four adhesive layers 14e to 14h are four short, straight adhesive layers 14 arranged on all four sides of the absorbent article 10. Note that the shape and arrangement of the adhesive layers 14 are not limited to the eight adhesive layers 14a to 14h described above, and various shapes and arrangements can be applied.

[0042] (Dimensions of the adhesive layer) The maximum longitudinal length L3 of the adhesive layer 14 is between 100% and 130% of the longitudinal length L2 of the absorbent material 13, which is set to 100%. If the maximum longitudinal length L3 of the adhesive layer 14 is smaller than the longitudinal length L2 of the absorbent material 13, the longitudinal ends of the absorbent material 30 will not be sufficiently fixed to the underwear, and the absorbent material 10 will lift away from the underwear, especially when the absorbent material 13 swells due to urination, making it prone to shifting and bunching. On the other hand, if the maximum longitudinal length L3 of the adhesive layer 14 is larger than 130% of the longitudinal length L2 of the absorbent material 13, which is set to 100%, the adhesive layer 14 provided in thin areas where there is no absorbent material 13 may not be pressed against the underwear and may stick to the buttocks or stomach.

[0043] If the adhesive layer 14 is divided into three equal parts in the longitudinal direction by imaginary lines VL1 and VL2 extending in the width direction, and these are designated as the first region 19, the second region 20, and the third region 21 from one side in the longitudinal direction, then the maximum widthwise length W3a of the first region 19 and the maximum widthwise length W3c of the third region 21 are between 100% and 130% of the widthwise length W2 of the absorbent material 13, which is set to 100%. If the maximum widthwise length W3a of the first region 19 and the maximum widthwise length W3c of the third region 21 are made smaller than the widthwise length W2 of the absorbent material 13, it becomes difficult to sufficiently fix both the left and right sides of the absorbent material 13 to the underwear, resulting in shifting and bunching. On the other hand, if the maximum length W3a in the width direction of the first region 19 and the maximum length W3c in the width direction of the third region 21 are made larger than 130% of the length W2 in the width direction of the absorbent material 13 (which is set to 100%), the adhesive layer 14 provided in the thin areas where the absorbent material 13 does not exist may not adhere to the underwear and may stick to the buttocks or stomach.

[0044] The maximum widthwise length W3b of the second region 20 of the adhesive layer 14 is between 60% and 80% of the widthwise length W2 of the absorbent material 13, which is set to 100%. If the maximum widthwise length W3b of the second region 20 is made smaller than 60% of the widthwise length W2 of the absorbent material 13, the adhesive properties will be poor, and shifting or wrinkles will occur. On the other hand, if the maximum widthwise length W3b of the second region 20 is made larger than 80% of the widthwise length W2 of the absorbent material 13, which is set to 100%, the adhesive layer 14 of the second region 20 may protrude outward from the crotch area of ​​the underwear and stick to the legs, and the adhesive layers 14 may stick to each other, causing wrinkles.

[0045] The maximum widthwise length W3a of the first region 19 and the maximum widthwise length W3c of the third region 21 of the adhesive layer 14 are preferably between 130% and 180% of the maximum widthwise length W3b of the second region 20, which is set to 100%. If the maximum widthwise length W3a of the first region 19 and the maximum widthwise length W3c of the third region 21 are smaller than 130% of the maximum widthwise length W3b of the second region 20, which is set to 100%, the adhesive strength will be poor, and slippage and wrinkles may occur. On the other hand, if the maximum widthwise length W3a of the first region 19 and the maximum widthwise length W3c of the third region 21 are larger than 180% of the maximum widthwise length W3b of the second region 20, which is set to 100%, the adhesive layer 14 may not adhere to the underwear and may stick to the buttocks or stomach.

[0046] The maximum length W3a in the width direction of the first region 19 of the adhesive layer 14 is preferably 55 mm or more and 80 mm or less. The maximum length W3b in the width direction of the second region 20 is preferably 35 mm or more and 60 mm or less. The maximum length W3c in the width direction of the third region 21 is preferably 55 mm or more and 80 mm or less. By setting the maximum lengths W3a, W3b, and W3c of each region of the adhesive layer 14 within the above ranges, the absorbent article 10 can be satisfactorily fixed to the underwear while maintaining sufficient comfort.

[0047] (Individually packaged sheets) The individual packaging sheet 16 is a sheet for individually packaging the absorbent article 10, and can hold, for example, the absorbent article 10 in a folded state. The individual packaging sheet 16 can individually package the absorbent article 10 by folding it back so as to enclose the absorbent article 10 with the adhesive layer 14 on the non-skin side of the absorbent article 10 adhered to one surface thereof. The above-mentioned one surface of the individual packaging sheet 16 is detachably adhered to the adhesive layer 14 of the back sheet 12 of the absorbent article 10.

[0048] The individual packaging sheet 16 is a non-woven fabric, a resin film, paper, or a laminate of two or more of these. It is preferable that a release agent such as a silicone-based release agent or a fluorine-based release agent is applied to one surface of the individual packaging sheet 16.

[0049] In this embodiment, the adhesive layer 14 of the absorbent article 10 is protected by the individual packaging sheet 16, but it is not limited thereto, and the adhesive layer 14 may be protected by other release paper or the like that is not the individual packaging sheet 16.

[0050] (Under-load thickness of absorbent article) 35 g / cm of the absorbent article 10 2 The under-load thickness is preferably 4.5 mm or less. If the thickness of the absorbent article 10 is made greater than 4.5 mm, the wearing comfort may decrease. In addition, since the absorber 13 that does not contain fluff pulp is likely to swell greatly after absorbing water, the wearing comfort after swelling particularly deteriorates significantly.

[0051] 35 g / cm of the absorbent article 10 2 The under-load thickness is measured by placing a weight that applies pressure on the absorbent article 10 in a state where the individual packaging sheet 16 is opened, the absorbent article 10 is removed, spread out, and placed on a reference surface, measuring the height from the reference surface to a predetermined position of the weight using a height gauge, and subtracting the height from the bottom surface of the weight itself to the above-mentioned predetermined position from the measured value. 2 Place a weight that applies pressure, measure the height from the reference surface to a predetermined position of the weight using a height gauge, and measure by subtracting the height from the bottom surface of the weight itself to the above-mentioned predetermined position from the measured value.

[0052] The thickness of the absorbent article 10 after injecting 40 ml of physiological saline solution into the absorbent material 13 (hereinafter referred to as "wet") is preferably 2 to 3.5 times the thickness before injection (hereinafter referred to as "dry"). If the thickness of the absorbent article 10 in the wet state is less than twice the thickness in the dry state, it will not absorb enough water and leakage is likely to occur. On the other hand, if the thickness of the absorbent article 10 in the wet state is greater than 3.5 times the thickness in the dry state, discomfort after urination will be greater, and shifting and bunching will also occur easily. Furthermore, the thickness of the absorbent article 10 in the wet state is preferably 5 mm to 10 mm. If the thickness of the absorbent article 10 in the wet state is less than 5 mm, it will not be able to absorb enough urine and leakage will occur easily. On the other hand, if the thickness of the absorbent article 10 in the wet state is greater than 10 mm, discomfort after urination will be greater, and it will be difficult to suppress shifting and bunching. Furthermore, the thickness of the absorbent article 10 when dry is 35 g / cm², as described above. 2 This is the thickness under load.

[0053] To measure the thickness of the absorbent article 10 when wet, first, pour 40 ml of physiological saline solution into the center of the absorbent article 10 to wet it, and let it stand for 10 minutes. Then, measure the thickness of the absorbent article 10 as described above (35 g / cm²). 2 The thickness of the absorbent article 10 when wet is measured using the same method as for the thickness under load.

[0054] In the absorbent article 10 configured as described above, the absorbent body 13 does not contain fluff pulp, the maximum length L3 in the longitudinal direction of the adhesive layer 14 is 100% or more and 130% or less when the length L2 in the longitudinal direction of the absorbent body 13 is taken as 100%, the maximum length W3a in the width direction of the first region 19 and the maximum length W3c in the width direction of the third region 21 of the adhesive layer 14 are 100% or more and 130% or less when the length W2 in the width direction of the absorbent body 13 is taken as 100%, and the maximum length W3b in the width direction of the second region 20 is 60% or more and 80% or less when the length W2 in the width direction of the absorbent body 13 is taken as 100%.

[0055] Therefore, according to this embodiment, even when using the absorbent material 13 of the highly absorbent sheet, it is possible to prevent shifting or bunching after urination, and to provide an absorbent article 10 that satisfies high standards in terms of adhesive strength to underwear, minimal transfer of the adhesive layer to underwear (residue), and comfort after urination.

[0056] Although the present invention has been described above based on the above embodiments, the present invention is not limited to the contents of the above embodiments, and can naturally be modified as appropriate without departing from the present invention. In other words, all other embodiments, examples, and operational techniques made by those skilled in the art based on these embodiments are of course included in the scope of the present invention. [Examples]

[0057] The present invention will be described in more detail below with reference to examples and comparative examples. However, the present invention is not limited in any way by the following examples.

[0058] (Examples 1-6 and Comparative Examples 1-4) Absorbent articles for Examples 1-6 and Comparative Examples 1-4 were prepared under the conditions shown in Table 1. Each of these absorbent articles was then evaluated based on the following four items: "shifting or peeling during wear," "wrinkling during wear," "minimal discomfort during wear," and "minimal adhesive residue."

[0059] (Shifting or peeling when worn) The evaluation of "shifting or peeling during wear" was based on sensory evaluation by 30 monitors. After the 30 monitors wore each absorbent item, a questionnaire was administered, and the evaluation was conducted based on the number of people who answered that no shifting or peeling of the absorbent item occurred, according to the following criteria. ○: More than 20 people reported "no shifting or peeling occurred." △: 10 to 19 people reported "no shifting or peeling occurred". ×: "No shifting or peeling occurred" for 9 or fewer people.

[0060] (Sagging when worn) The evaluation of "wrinkling during wear" was based on sensory evaluation by 30 monitors. After the 30 monitors wore each absorbent item, a questionnaire was administered, and the evaluation was conducted according to the following criteria based on the number of people who answered that no wrinkling occurred in the absorbent item. ○: More than 20 people reported "no wrinkles occurred." △: 10 to 19 people reported "no wrinkles occurred". ×: 9 or fewer people reported "No wrinkles occurred."

[0061] (Minimal discomfort when worn) The evaluation of "minimal discomfort during wear" was based on a sensory evaluation by 30 monitors. After the 30 monitors wore each absorbent item, a questionnaire was administered, and the following criteria were used to evaluate the product based on the number of people who reported minimal discomfort during wear. ○: More than 20 people answered "It felt less strange." △: 10 to 19 people answered "little discomfort". ×: 9 or fewer people answered "feeling that there was little discomfort".

[0062] (Less adhesive residue) The evaluation of "minimal adhesive residue" was based on a sensory evaluation by 30 monitors. After the 30 monitors wore each absorbent item, a questionnaire was administered, and the following criteria were used to evaluate the product based on the number of people who responded that there was minimal adhesive residue from the absorbent item's adhesive layer on their underwear. ○: More than 20 people answered "Less adhesive residue". △: "Less adhesive residue" was reported by 10 to 19 people. ×: "Less adhesive residue" was answered by 9 or fewer people.

[0063] The results obtained are shown in Table 1. In the table, "anti-slip" refers to the adhesive layer or adhesive. Furthermore, "A" in "anti-slip" refers to a continuous straight adhesive layer located on the inside in the width direction, and "B" refers to four short straight adhesive layers located on the outside in the width direction, arranged on all four sides. Also, "thickness under load" is the thickness of the yielding material when dry (35 g / cm²). 2"Swelling thickness" indicates the thickness of the absorbent material under load, and "thickness ratio" indicates the thickness of the absorbent material when wet.

[0064] [Table 1]

[0065] As shown in Table 1, Examples 1 to 6 confirmed that even when using a highly absorbent sheet as the absorbent material, it is possible to prevent shifting or bunching after urination, and that absorbent articles can be provided that meet high standards in terms of adhesive strength to underwear, minimal transfer of the adhesive layer to underwear (residue), and comfort after urination. [Explanation of symbols]

[0066] 10: Absorbent articles 11: Top sheet 12: Back seat 13: Absorbent material 14: Adhesive layer 17: Nonwoven fabric sheet 18: Superabsorbent polymers 19:First area 20:Second area 21: Third area

Claims

1. An absorbent article comprising a liquid-permeable top sheet on the skin side, a liquid-impermeable back sheet on the non-skin side, an absorbent material disposed between the top sheet and the back sheet, and an adhesive layer provided on the non-skin side of the back sheet, The absorbent material does not contain fluff pulp. The maximum length in the longitudinal direction of the adhesive layer is 100% or more and 130% or less of the longitudinal length of the absorbent, with the longitudinal length of the absorbent being set to 100%. When the adhesive layer is divided into three equal parts in the longitudinal direction by imaginary lines extending in the width direction, and these are designated as the first region, the second region, and the third region from one side in the longitudinal direction, the maximum length in the width direction of the first region and the maximum length in the width direction of the third region are 100% or more and 130% or less of the width direction length of the absorbent material, The maximum length in the width direction of the second region is 60% or more and 80% or less of the width direction length of the absorber, with the width direction length being 100%. An absorbent article characterized by the following features.

2. The absorbent material is a highly absorbent sheet having a nonwoven fabric sheet and a highly absorbent polymer. The shape of the absorber is rectangular. The shape of the absorbent article is such that the central part in the longitudinal direction is constricted inward in the width direction. The absorbent article according to feature 1.

3. The basis weight of the superabsorbent polymer in the absorbent material is 400 g / m². ２ More than 1000g / m ２ The following is The absorbent article according to feature 2.

4. 35 g / cm³ of the absorbent article ２ The thickness under load is 4.5 mm or less. The thickness of the absorbent article after adding 40 ml of physiological saline to the absorbent material is between 2 and 3.5 times its thickness before adding the saline solution. The absorbent article according to claim 1 or 2.

5. The adhesive layer is a layer of adhesive applied to the non-skin side of the back sheet. The amount of adhesive applied is 20 gsm or more and 60 gsm or less. The adhesive layer consists of 3 to 6 continuous straight lines and 4 short straight lines arranged on all four sides. The absorbent article according to claim 1 or 2.

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