Sheet for absorbent article and absorbent article using same

Abstract

To provide a sheet for an absorbent article in which a body fluid hardly remains on a skin of a wearer.SOLUTION: A sheet 1 for an absorbent article in the present invention includes: a first fiber layer 11 including a first surface F and synthetic fibers 2; and a second fiber layer 12 including a second surface R positioned on an opposite side of the first surface F and cellulose fibers 3. The first fiber layer 11 includes fibers having a contact angle less than 90° with water. In the second fiber layer 12, a Klemm water absorption height measured according to JIS P8141 is 4 cm or more. An embossment part 15 is formed in the first fiber layer 11, and an uneven shape having a plurality of recessed parts 17 formed by the embossment part 15 and a protruding part 18 formed between the recessed parts 17 is formed on the first surface F.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a sheet for absorbent articles and an absorbent article using the same. [Background technology]

[0002] In absorbent articles such as disposable diapers, a multi-layered nonwoven fabric is used on the skin-facing side of the absorbent article to absorb liquid excreted by the wearer and improve the comfort of use. The applicant has proposed an absorbent article with a surface material consisting of a layer formed of a nonwoven fabric containing a thermoplastic resin and a layer formed of an absorbent sheet containing at least cellulose fibers, with the aim of reducing liquid residue on the surface (see Patent Document 1).

[0003] The applicant has also proposed an absorbent article having a back waist flap in which a hydrophobic skin-side sheet forming the skin-contacting surface and a hydrophilic non-skin-side sheet located on the non-skin-facing side of the skin-side sheet are joined by multiple joints, with the aim of quickly transferring absorbed sweat to the non-skin-facing side (see Patent Document 2).

[0004] Patent Document 3 discloses a disposable diaper that includes a sweat-absorbent sheet consisting of an inner layer on the side that contacts the skin and an outer layer on the opposite side, in which the inner layer is formed from a mixture of hydrophobic fibers and hydrophilic fibers, and the outer layer is formed containing 50 to 100% by weight of hydrophilic fibers. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Application Publication No. 8-66425 [Patent Document 2] JP 2017-113188 A [Patent Document 3] JP 2001-327534 A Summary of the Invention [Problem to be solved by the invention]

[0006] The absorbent articles described in Patent Documents 1 and 2 quickly transfer absorbed liquid to the non-skin facing side, making it difficult for bodily fluids to remain on the wearer's skin, but there is room for improvement in terms of further reducing the amount of liquid remaining on the skin. Also, the absorbent article described in Patent Document 3 cannot be said to have sufficiently achieved a reduction in the amount of liquid remaining on the skin.

[0007] Therefore, an object of the present invention is to provide a sheet for absorbent articles that prevents bodily fluids from remaining on the wearer's skin. [Means for solving the problem]

[0008] The present invention provides a textile fabric comprising a first surface, a first fibrous layer comprising synthetic fibers; a second fiber layer including cellulose fibers and including a second surface opposite to the first surface; the first fibrous layer comprises fibers having a contact angle with water of less than 90°; The first fiber layer has an embossed portion formed thereon, a concave-convex shape having a plurality of concave portions formed by the embossed portion and convex portions formed between the concave portions is formed on the first surface, The present invention provides a sheet for absorbent articles, in which the Klemm water absorption height of the second fiber layer measured in accordance with JIS P8141 is 4 cm or more.

[0009] The present invention also provides a sheet for absorbent articles, The present invention provides an absorbent article using the sheet as a top sheet or a sweat-absorbing sheet. Effect of the Invention

[0010] According to the present invention, there is provided a sheet for absorbent articles which prevents excreted body fluid from remaining on the wearer's skin. [Brief description of the drawings]

[0011] [Figure 1]1(a) and (b) are perspective views that typically show one embodiment of the absorbent article sheet of the present invention in a no-load state. [Diagram 2] 2(a) and (b) are cross-sectional views that diagrammatically show an embodiment of the cross section taken along line II in FIG. 1(b). DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0012] The present invention will be described below based on preferred embodiments with reference to the drawings. An absorbent article sheet 1 (hereinafter, simply referred to as "sheet 1") shown in Figures 1 and 2 is suitable for use as a component of an absorbent article that absorbs excreted body fluids such as urine, sweat, and menstrual blood.

[0013] 1 and 2 are schematic diagrams showing an embodiment of the sheet 1 in a no-load state. The sheet 1 has a first surface F and a second surface R, which is a surface located on the opposite side of the first surface F. When the sheet 1 is used as a component of an absorbent article, the first surface F is preferably arranged on the skin-contacting surface side, which is a surface that contacts the skin of a wearer, and the second surface R is preferably arranged on the non-skin-contacting surface side, which is a surface opposite to the skin-contacting surface. The sheet 1 is a multi-layered sheet in which a first fiber layer 11 including the first surface F and a second fiber layer 12 including the second surface R are integrated. In the embodiment shown in FIG. 1 and FIG. 2, the sheet has a two-layered structure in which the fiber layers 11 and 12 are arranged adjacent to each other. Details of the fibers contained in the fiber layers 11 and 12 will be described later.

[0014] The sheet 1 has an embossed portion 15 formed at least in the first fiber layer 11, and preferably the first fiber layer 11 and the second fiber layer 12 are joined by the embossed portion 15. The embossed portion 15 is a portion where the fiber layer is compressed in the thickness direction, the fibers are not fused to each other, and the fiber density is higher than in the portion other than the embossed portion 15, or the fibers are fused to each other. By forming the embossed portion 15 at least in the first fiber layer 11, an uneven shape having a plurality of recesses 17 formed by the embossed portions 15 and protrusions 18 formed between the recesses 17 is formed on one side of the first surface F of the sheet 1. In other words, the recesses 17 are formed in correspondence with the portions where the embossed portions 15 are formed, and a plurality of protrusions 18 are formed in the portions where the embossed portions 15 are not formed. In particular, by bonding the first fiber layer 11 and the second fiber layer 12 with the embossed portions 15, bodily fluids can be easily transferred to the second fiber layer through the embossed portions where the fibers are densely present, thereby reducing the amount of fluid remaining on the first fiber layer side. In addition, while achieving the above-mentioned effects, there are also advantages in that the production efficiency of the sheet 1 can be improved and a sheet strength sufficient for use can be easily achieved.

[0015] The embossed portion 15 formed on the sheet 1 may be formed of continuous straight lines inclined in opposite directions to each other with respect to the X direction when the sheet 1 is viewed in a plan view, as shown in FIG. 1(a). In the form of the embossed portion 15 shown in FIG. 1(a), when the sheet 1 is viewed in a plan view, a first embossed line 15A formed as a continuous straight line and a second embossed line 15B formed as a continuous straight line are formed inclined in opposite directions to each other with respect to the X direction. The first embossed line 15A and the second embossed line 15B shown in the figure are each formed in a large number parallel to each other. In addition, the intervals between the adjacent first embossed lines 15A and the intervals between the adjacent second embossed lines 15B are approximately the same. The positions where the first embossed line 15A and the second embossed line 15B are formed are the positions of the recesses 17 on the first surface F. Moreover, the area defined by the two first embossed lines 15A and the two second embossed lines 15B corresponds to the position of the convex portion 18 on the first face F.

[0016] As another embodiment of the embossed portion 15 formed on the sheet 1, for example, as shown in FIG. 1(b), when the sheet 1 is viewed in plan, the embossed portion 15 may be formed in a scattered dot pattern in the sheet surface direction. In the embodiment of the embossed portion 15 shown in FIG. 1(b), when the sheet 1 is viewed in plan, a plurality of circular embossed portions 15 are formed at predetermined intervals. The embossed portion 15 shown in the figure constitutes a plurality of embossed portion rows 15C extending in a direction perpendicular to the X direction, and the adjacent embossed portion rows 15C are formed with the same pitch and with a phase shift of half a pitch. Alternatively, the pitches may be different between the adjacent embossed portion rows 15C. In addition, the phase shift between the adjacent embossed portion rows 15C may be periodic or non-periodic.

[0017] The planar shape of the embossed portions 15 formed in a scattered manner may be a circle as shown in Fig. 1(b), a polygonal shape such as a rectangle or a hexagon, an alphabetical shape such as an X-shape or a Y-shape, a lattice shape, or a combination of these. The positions at which the embossed portions 15 are formed correspond to the positions of the recessed portions 17 on the first surface F. Moreover, the area surrounded by four embossed portions 15 corresponds to the positions of the protruding portions 18 on the first surface F. Of the above-mentioned modes of forming the embossed portions 15, it is preferable that the embossed portions 15 are formed in a scattered manner in the sheet surface direction, from the viewpoint of increasing the number of starting points from which the attraction of bodily fluids occurs and increasing the flexibility of the sheet.

[0018] 2(a) and (b) show schematic cross-sectional views of the sheet 1. The embossed portion 15 shown in the figure is formed so as to bond the first fiber layer 11 and the second fiber layer 12 together. The sheet 1 is formed by the embossed portion 15, and a plurality of recesses 17 recessed toward the second surface R side and a plurality of protrusions 18 protruding toward the first surface F side are formed on the first surface F. The recesses 17 are portions having a smaller sheet thickness than the protrusions 18. The heights of the recesses 17 and the protrusions 18 may be the same or different. On the other hand, the second surface R of the sheet 1 has a flat shape. Alternatively, the second surface may have a concave-convex shape in which a plurality of recesses and protrusions are formed so as to match the positions of the recesses 17 and the protrusions 18 on the first surface F. The boundary surface between the fiber layers 11, 12 at the protrusions 18 is preferably clear. In the embossed portion 15, the boundary surface between the fiber layers 11, 12 does not exist or is unclear.

[0019] Furthermore, the convex portion 18 may have a solid structure configured so that the first fiber layer 11 and the second fiber layer 12 are in contact with each other, as shown in FIG. 2(a), or alternatively, may have a hollow structure in which the first fiber layer 11 and the second fiber layer 12 are separated from each other and have a space S defined by the lower surface of the first fiber layer 11 and the upper surface of the second fiber layer 12, as shown in FIG. 2(b).

[0020] The first fiber layer 11 of the sheet 1 shown in Figures 2(a) and (b) is composed of a fiber assembly mainly containing synthetic fibers 2. The second fiber layer 12 shown in the same figures is composed of a fiber assembly mainly containing cellulose fibers 3. In this specification, "mainly" means that the mass ratio of the constituent fibers to the mass of one fiber layer is 50 mass% or more. Note that the synthetic fibers 2 and the cellulose fibers 3 shown in Figures 2(a) and (b) are illustrated as having different fiber diameters, but this is only shown in this manner for the convenience of explaining the first fiber layer and the second fiber layer. The fiber diameters of both fibers may be the same, or the fiber diameter of the cellulose fibers 3 may be larger than the fiber diameter of the synthetic fibers 2, or the fiber diameter of the synthetic fibers 2 may be larger than the fiber diameter of the cellulose fibers 3.

[0021] Examples of the synthetic fibers contained in the first fiber layer 11 include fibers containing one or more thermoplastic resins such as polyolefin resins such as polyethylene (PE) and polypropylene (PP), polyester resins such as polyethylene terephthalate (PET), polyamide resins, vinyl resins such as polyvinyl chloride and polystyrene, acrylic resins such as polyacrylic acid and polymethyl methacrylate, and fluororesins such as polyperfluoroethylene, as polymer components. These fibers may be subjected to a hydrophilic or hydrophobic treatment on the fiber surface as necessary. These fibers may be used alone or in combination of two or more kinds.

[0022] When a thermoplastic fiber is used as the synthetic fiber, the fiber may or may not have heat shrinkability. An example of a thermoplastic fiber having heat shrinkability is a latent crimp fiber. A latent crimp fiber can be handled in the same way as a normal fiber before being heated, and has the property of developing a helical crimp and shrinking when heated at a predetermined temperature. A latent crimp fiber is, for example, an eccentric core-sheath type or a side-by-side type composite fiber made of two types of thermoplastic resins with different shrinkage rates. Examples of the latent crimp fiber include those described in JP-A-9-296325 and JP-A-2-191720.

[0023] Examples of the cellulose fibers contained in the second fiber layer 12 include natural cellulose fibers such as cotton fibers and pulp fibers, regenerated cellulose fibers such as rayon, refined cellulose fibers such as lyocell fibers (Tencel (registered trademark) and Veocel (registered trademark)), and semi-synthetic cellulose fibers such as acetate fibers. These fibers can be used alone or in combination of two or more kinds.

[0024] As the fiber assemblies constituting the first fiber layer 11 and the second fiber layer 12, various fiber sheets containing the above-mentioned fibers, such as paper, woven fabric, and nonwoven fabric, can be used independently. When a nonwoven fabric is used, various nonwoven fabrics such as an air-through nonwoven fabric, an air-laid nonwoven fabric, a spunbond nonwoven fabric, a spunlace nonwoven fabric, a meltblown nonwoven fabric, and a needle-punched nonwoven fabric can be used.

[0025] The fibers constituting the first fiber layer 11 include fibers having a contact angle between the fiber and water of less than 90°, preferably 70° or less, more preferably 50° or less, and realistically include fibers having a contact angle of 0° or more.

[0026] The contact angle of the fibers with water can be measured by the following method: The fibers located on the first surface of the sheet 1 are carefully removed using tweezers and a razor or scissors so that the fibers have a length of 1 mm or more without being pulled, and the contact angle of water with these fibers is measured. The measurement device used is an automatic contact angle meter MCA-J manufactured by Kyowa Interface Science Co., Ltd. The contact angle is measured using distilled water in an environment with a temperature of 22±2°C and a humidity of 60±5%RH. The amount of liquid discharged from the inkjet type water droplet discharge part (CTC-25 pulse injector manufactured by Cluster Technology Co., Ltd. with a discharge part hole diameter of 25 μm) is set to 10 picoliters, and the water droplets are dropped directly onto the fiber. The dropping state is recorded by a high-speed recording device connected to a camera installed horizontally. From the viewpoint of later image analysis and image analysis, it is preferable that the recording device is a personal computer with a high-speed capture device. In this measurement, images are recorded every 17 milliseconds (17 msec). In the recorded video, the first image of the water droplet landing on the fiber taken from sheet 1 is analyzed using the attached software FAMAS (software version 2.6.2, analysis method is droplet method, analysis method is θ / 2 method, image processing algorithm is non-reflective, image processing image mode is frame, threshold level is 200, curvature correction is not performed), the angle between the surface of the water droplet that touches the air and the fiber is calculated, and the angle on the side where the water droplet and the fiber are in contact is taken as the contact angle. The fiber taken from the first surface of the sheet is cut to a fiber length of 1 mm, the fiber is placed on the sample stage of the contact angle meter and maintained horizontally, and the contact angles at three different points for each fiber are measured to one decimal place, and the arithmetic average value (rounded off to two decimal places) is taken as the contact angle of the fiber. This procedure is repeated for the 100 fibers constituting the first fiber layer to calculate the contact angle of each fiber. If at least one of the 100 fibers randomly selected from the surface of the first fiber layer has a contact angle of less than 90°, the first fiber layer 11 is determined to contain fibers with a contact angle with water of less than 90°. The smaller the contact angle with water, the more hydrophilic the fiber is.

[0027] When the average fiber contact angle is the arithmetic mean of the contact angles of 100 fibers measured by the above-mentioned method, the average fiber contact angle of the first fiber layer 11 is preferably 100° or less, more preferably 90° or less, even more preferably 80° or less, and is preferably 50° or more, more preferably 55° or more, and even more preferably 60° or more. When the average fiber contact angle of the first fiber layer 11 is within such a range, body fluids can easily adhere to the first fiber layer 11, and the body fluids can be transferred to the second fiber layer 12 without being retained in the first fiber layer 11.

[0028] In the above-mentioned measurement of the contact angle between the fiber and water, if it is difficult to obtain fibers with a fiber length of 1 mm, the sheet 1 is placed on a sample table, and water droplets are applied to the fibers in the measurement target surface of the sheet 1, where the surface of the sample table and the fiber surface are approximately parallel, by the above-mentioned method, to measure the contact angle of the fiber. In addition, if the sheet to be measured is incorporated in an absorbent article, a region including the sheet is cut out together with other components to obtain a test piece, and the sheet to be measured is carefully peeled off while blowing hot air onto the test piece using a dryer or the like to remove the influence of the adhesive, and this is the sample to be used in this measurement. This method is common to other measurements in this specification. In addition, in measuring the contact angle between the fiber and water described above, if the fiber has high water absorption and water droplets that land on the fiber disappear in 17 milliseconds or less, making it difficult to measure the contact angle every 17 milliseconds, the contact angle between the fiber being measured and water is deemed to be 20°.

[0029] Regarding the first fiber layer 11, the Klemm water absorption height C1 of the first fiber layer 11 is preferably 0 cm or more, preferably 2 cm or less, and more preferably 1 cm or less. The higher the Klemm water absorption height, the higher the liquid diffusibility in the sheet surface direction and thickness direction. Therefore, this configuration facilitates the transfer of bodily fluids from the first fiber layer 11 to the second fiber layer 12, and makes it difficult for bodily fluids to remain on the wearer's skin and the first fiber layer 11 side.

[0030] As for the second fiber layer 12, the Klemm water absorption height C2 of the second fiber layer 12 is preferably 4 cm or more, more preferably 5 cm or more, and realistically 9 cm or less. This configuration facilitates the transfer of bodily fluids from the first fiber layer 11 to the second fiber layer 12, and makes it difficult for the bodily fluids transferred to the second fiber layer 12 to return to the first fiber layer 11, thereby making it difficult for the bodily fluids to remain on the wearer's skin.

[0031] In terms of the relationship between the Klemm absorption heights of the fiber layers 11 and 12, it is preferable that the Klemm absorption height C1 of the first fiber layer 11 is lower than the Klemm absorption height C2 of the second fiber layer 12. In particular, the difference (C2-C1) between the Klemm absorption height C1 of the first fiber layer 11 and the Klemm absorption height C2 of the second fiber layer 12 is preferably 3 cm or more, more preferably 4 cm or more, and realistically 9 cm or less, on the condition that C2>C1. With this configuration, the second fiber layer 12 exhibits higher hydrophilicity than the first fiber layer 11, which makes it easier for bodily fluids to migrate from the first fiber layer 11 to the second fiber layer 12, and makes it more difficult for bodily fluids that have migrated to the second fiber layer 12 to return to the first fiber layer 11. In order to make the Klemm water absorption heights of the fiber layers 11 and 12 different from each other, the type of cellulose fiber contained in the first fiber layer and the type of cellulose fiber contained in the second fiber layer can be made different from each other. In this case, for example, at least one of regenerated cellulose fiber, refined cellulose fiber, and semi-synthetic cellulose fiber may be used as the cellulose fiber contained in the first fiber layer, and pulp fiber may be used as the cellulose fiber contained in the second fiber layer. In order to make the Klemm absorbency heights of each fiber layer 11, 12 different from each other, the type of cellulose fiber contained in the first fiber layer and the type of cellulose fiber contained in the second fiber layer can be the same, and the proportion of cellulose fiber contained in the first fiber layer can be made lower than the proportion of cellulose fiber contained in the second fiber layer.

[0032] The above-mentioned Klemm water absorption height can be measured, for example, in accordance with JIS P8141. In detail, first, the absorbent sheet to be measured is cut into a rectangle of 10 cm in the fiber flow direction and 3 cm in the direction perpendicular to the fiber flow direction to prepare a measurement piece. If the fiber flow direction cannot be determined visually, 10 or more fibers present on the sheet surface are observed using a microscope or scanning electron microscope, and the direction in which the extension direction of the fibers extends by 50% or more by number is determined to be the fiber flow direction. The test piece is then fixed so that the longitudinal direction of the test piece is perpendicular to the planar direction, and in this state, the test piece is immersed for 3 minutes in ion-exchanged water colored with 0.1 mass % of blue dye (Blue No. 1, for example, manufactured by Hodogaya Chemical Co., Ltd.) dissolved therein. The height from the water surface (the height of the solvent tip, with a position 1 cm above the longitudinal lower end of the test piece as the reference point) is then measured at four points spaced 1 cm apart along the width direction of the test piece, starting from one end in the width direction, and the arithmetic average value is the Klemm water absorption height (cm) in the present invention. When the Klemm water absorption height differs between one side and the other side of the test piece, the side of the test piece with the lower Klemm water absorption height is taken as the side facing the first fiber layer 11, and the Klemm water absorption height of this side is taken as the Klemm water absorption height C1 of the first fiber layer 11. Moreover, the side of the test piece with the higher Klemm water absorption height is taken as the side facing the second fiber layer 12, and the Klemm water absorption height of this side is taken as the Klemm water absorption height C2 of the second fiber layer 12.

[0033] In the absorbent article sheet having the above-mentioned configuration, the contact angle of the constituent fibers of the first fiber layer with water is less than a predetermined value, so that, for example, when the sheet is arranged so that its first surface constitutes the skin contact surface of the absorbent article, sweat adhering to the wearer's skin and body fluids excreted from the wearer can easily come into contact with the sheet surface. In addition, since the Klemm water absorption height of the second fiber layer is set to a predetermined value, the transfer of body fluids from the first fiber layer to the second fiber layer having a relatively high hydrophilicity, and further the transfer of body fluids to the side of the second fiber layer where the first fiber layer is not present, can be facilitated, and the body fluid drawn into the second fiber layer side can be made less likely to return to the first fiber layer side. As a result, the body fluid can be made less likely to remain on the wearer's skin. This effect is more remarkable when the Klemm water absorption height of the first fiber layer is further adopted as a predetermined value. In addition, the embossed portion 15 formed on the sheet can increase the density of the embossed portion 15 and the fibers around it, improving the capillary force, so that the embossed portion 15 can be used as an absorption starting point to easily draw body fluids into the sheet. Furthermore, the uneven shape formed on the first surface of the sheet 1 reduces the contact area between the sheet and the wearer's skin compared to a case where the uneven shape is not formed. As a result, body fluids are less likely to remain on the wearer's skin, and skin troubles such as eczema and rash caused by the remaining body fluids on the skin and friction between the sheet and the wearer's skin can be reduced.

[0034] From the viewpoint of increasing the ability to draw bodily fluids into the sheet and reducing the amount of the drawn fluid returning to the first fiber layer 11, the embossed portion 15 of the first fiber layer 11 in the cross-sectional view of the sheet is preferably formed on the second fiber layer side. Formed on the second fiber layer side means that when a virtual dividing line L1 is drawn that virtually divides the first fiber layer 11 equally in the thickness direction, the embossed portion 15 is located biased toward the second fiber layer side. Such a configuration can be formed, for example, by forming the embossed portion 15 so as to press the first fiber layer 11 toward the second fiber layer 12 side in a state in which the first fiber layer 11 and the second fiber layer 12 are laminated, or by pressing the first fiber layer 11 in the thickness direction in advance to form the embossed portion 15, and arranging the surface of the first fiber layer 11 on the side where the embossed portion 15 is present facing the second fiber layer 12.

[0035] A preferred embodiment of the constituent fibers in each of the fiber layers 11 and 12 will be described below. The first fiber layer 11 preferably further contains cellulose fibers in addition to the synthetic fibers 2, and more preferably contains at least one of regenerated cellulose fibers, refined cellulose fibers, and semi-synthetic cellulose fibers as the cellulose fibers. The first fiber layer 11 is also preferably a nonwoven fabric made of a mixture of the synthetic fibers 2 and cellulose fibers. Since cellulose fibers are generally highly hydrophilic, by further containing cellulose fibers in the first fiber layer 11, bodily fluids attached to or remaining on the wearer's skin can be efficiently transferred to the sheet side, and the remaining of bodily fluids on the wearer's skin can be further reduced. In addition, by using regenerated cellulose fibers or refined cellulose fibers, there is an advantage that the manufacturing efficiency of the sheet 1 can be improved and the touch and texture of the obtained sheet can be improved. The cellulose fibers that can be contained in the first fiber layer 11 can be the above-mentioned ones. Moreover, the cellulose fibers that can be contained in the first fiber layer 11 may be the same type as the cellulose fibers 3 contained in the second fiber layer 12, or may be different types.

[0036] The content of synthetic fibers in the first fiber layer 11 is preferably 50% by mass or more, more preferably 80% by mass or more, even more preferably 85% by mass or more, and preferably 100% by mass or less, more preferably 95% by mass or less, based on the total mass of the first fiber layer 11. In other words, the first fiber layer 11 may be formed only from synthetic fibers. Furthermore, when the first fiber layer 11 contains cellulose fibers, the content of cellulose fibers in the first fiber layer 11 is preferably 0% by mass or more, more preferably 5% by mass or more, and preferably 20% by mass or less, more preferably 15% by mass or less.

[0037] The determination of whether or not the first fiber layer 11 contains cellulose fibers and the content thereof can be determined, for example, by dyeing the sheet 1 with a fiber identification reagent (BOKENSTAIN II, manufactured by the Boken Quality Evaluation Organization, a general incorporated foundation) and observing the side or cross section of the sheet, and if fibers discolored blue are present in the first fiber layer 11, it can be determined that the first fiber layer 11 contains cellulose fibers. The content of cellulose fibers in the first fiber layer 11 can be determined by taking out the first fiber layer 11 at any position such as the convex portion 18 of the sheet 1, measuring the total mass of the first fiber layer 11, and then dyeing the constituent fibers of the first fiber layer 11 with the above-mentioned fiber identification reagent, and taking out only the fibers discolored blue. The discolored fibers are separated one by one and dried, and the total mass of the discolored fibers is measured, which is defined as the content of cellulose fibers in the first fiber layer 11. In other words, the percentage of the content of the cellulose fibers with respect to the total mass of the first fiber layer 11 is defined as the content ratio of cellulose fibers in the first fiber layer 11.

[0038] When the first fiber layer 11 contains cellulose fibers, the contact angle θ1 between the cellulose fibers contained in the first fiber layer 11 and water is preferably 0° or more, and preferably 60° or less, and more preferably 50° or less, from the viewpoint of promoting adhesion of body fluids such as sweat to the first fiber layer 11.

[0039] As for the second fiber layer 12, the cellulose fiber mainly contained in the second fiber layer 12 is preferably pulp fiber, and the second fiber layer 12 is also preferably paper. With such a configuration of the second fiber layer 12, the high hydrophilicity and liquid retention of the pulp fiber can more efficiently transfer the body fluid that has come into contact with the first fiber layer to the second fiber layer, and the amount of body fluid remaining on the skin can be further reduced. Paper, which is a suitable form of the second fiber layer 12, is produced by agglutinating plant fibers such as pulp fibers and other fibers such as synthetic fibers as necessary in accordance with the provisions of JIS P0001, and is preferably produced by a wet method.

[0040] In addition, the second fiber layer 12 preferably further contains synthetic fibers in addition to the cellulose fibers 3. In this case, the synthetic fibers that can be contained in the second fiber layer 12 may be the same type as the synthetic fibers 2 contained in the first fiber layer 11, or may be different types. In particular, when the second fiber layer 12 contains synthetic fibers, it is more preferable that the synthetic fibers contained in the first fiber layer and the synthetic fibers contained in the second fiber layer contain the same polymer components. With such a configuration, it becomes easy to form the embossed portion that bonds the first fiber layer 11 and the second fiber layer 12 by fusion, and the embossed portion 15 exhibits strong bonding properties, thereby improving the strength of the sheet.

[0041] Whether the synthetic fibers contained in each fiber layer contain the same polymer component can be determined by the following method. First, the sheet 1 is dyed with the above-mentioned fiber identification reagent, and undyed fibers are taken out from each side F and R of the sheet. The fibers taken out from the first side F are the synthetic fibers contained in the first fiber layer 11, and the fibers taken out from the second side R are the synthetic fibers contained in the second fiber layer 12. These synthetic fibers are measured using a differential scanning calorimeter (DSC6200 manufactured by Seiko Instruments Inc.). A thermal analysis of a finely cut fiber sample (sample mass 1 mg) is performed at a heating rate of 10°C / min to measure the melting peak temperature (°C) of each fiber. When the melting peak of the synthetic fiber contained in the first fiber layer 11 and the melting peak of the synthetic fiber contained in the second fiber layer 12 are measured, if there is a range where the melting peaks overlap within a range of ±2°C, it is determined that the synthetic fibers contained in each fiber layer contain the same polymer component.

[0042] The content of cellulose fibers in the second fiber layer 12 is preferably 50% by mass or more, more preferably 70% by mass or more, even more preferably 75% by mass or more, and preferably 100% by mass or less, more preferably 95% by mass or less, and even more preferably 90% by mass or less, based on the total mass of the second fiber layer 12. In other words, the second fiber layer 12 may be formed only from cellulose fibers. In addition, when the second fiber layer 12 contains synthetic fibers, the content of synthetic fibers in the second fiber layer 12 is preferably 0% by mass or more, more preferably 5% by mass or more, even more preferably 10% by mass or more, and preferably 50% by mass or less, more preferably 30% by mass or less, and even more preferably 25% by mass or less. The determination of whether the second fiber layer 12 contains cellulose fibers and the content thereof can be measured in the same manner as the measurement method for the first fiber layer 11 described above.

[0043] The thickness T1 (see FIG. 2) of the first fiber layer 11 is preferably 600 μm or less, more preferably 500 μm or less, even more preferably 450 μm or less, and preferably 100 μm or more, more preferably 200 μm or more. By making the thickness T1 thin within the above-mentioned range, the body fluid present on the wearer's skin can be quickly transferred to the second fiber layer side, and the residual liquid on the skin can be more effectively reduced. In order to make the thickness T1 within the above-mentioned range, for example, a latent crimping fiber such as a core-sheath type composite fiber can be used as the constituent fiber of the first fiber layer 11, or the sheet can be compressed in the thickness direction after production of the sheet.

[0044] The thickness T2 (see FIG. 2) of the second fiber layer 12 is preferably 250 μm or more, more preferably 300 μm or more, and is preferably 800 μm or less, more preferably 400 μm or less. This thickness ensures both the liquid retention on the second fiber layer 12 side and the softness of the sheet.

[0045] The thickness T1 can be measured by the following method. First, the sheet 1 to be measured is immersed in liquid nitrogen under a load of 49 Pa to fix the sheet shape while maintaining the concave-convex structure. Next, the sheet 1 is cut in the thickness direction of the sheet 1 using a razor and a hammer so as to include the tops of the convex portions 18 of the sheet 1 and not to crush the cut surface, to obtain a cross section. Thereafter, the sheet cross section is observed with a microscope (manufactured by Keyence Corporation, digital microscope VHX-1000), and the length along the thickness direction from the boundary between the first fiber layer 11 and the second fiber layer 12 to the tops of the convex portions 18 is measured. The boundary between the first fiber layer 11 and the second fiber layer 12 can be determined by determining the boundary between the regions where the constituent fibers of each fiber layer are mostly observed to be the same in thickness and type in an enlarged photograph of the sheet cross section obtained by microscope observation; alternatively, the sheet to be measured can be dyed by gently immersing it in ion-exchanged water containing 0.1% by mass of Blue No. 1, and then an enlarged photograph of the sheet cross section can be taken using a microscope. In the enlarged photograph, the boundary between the layer with a relatively dark blue color and the layer with a relatively light blue color can be determined as the boundary between the first fiber layer 11 and the second fiber layer 12. The above-mentioned length measurement is performed on an area including 100 different protrusions 18, and the arithmetic average of the thicknesses obtained at the 100 locations is defined as the thickness T1 of the first fiber layer 11. When the protrusions 18 are hollow, the length along the thickness direction from the first surface side of the second fiber layer 12 to the top of the protrusion 18 is measured and calculated by the above-mentioned method, and is defined as thickness T1. The thickness T2 of the second fiber layer 12 is determined by obtaining a cross section of the sheet using the same method as described above, measuring the length from the first surface side of the second fiber layer 12 to the second surface side at 100 different locations, and calculating the arithmetic average of the thicknesses obtained at the 100 locations.

[0046] As long as the effects of the present invention are achieved, another fiber layer may be disposed between the first fiber layer 11 and the second fiber layer 12.

[0047] The sheet for absorbent articles preferably has a liquid remaining rate of a predetermined value or less, as measured by the following measurement method. In detail, the liquid remaining rate of the sheet 1 is preferably 20% or less, more preferably 10% or less, and even more preferably 8% or less. With such a value, when the sheet for absorbent articles is used as a component of an absorbent article, the sheet has a high ability to draw body fluids into the sheet side, and body fluids are less likely to remain on the wearer's skin, so that skin troubles caused by body fluids remaining on the skin can be effectively reduced.

[0048] The liquid remaining rate of the sheet for absorbent articles is measured by the following procedures (1) to (3). <Method for measuring residual liquid rate> (1) Arrange 49 drops of 1 mg each of 49 mg of ion-exchanged water within a 5 cm square frame on a glass plate. (2) The first surface of the absorbent article sheet cut into a 5 cm square is placed in contact with each of the water drops on a glass plate, and left to stand for 1 minute under a load of 0.8 kPa. (3) The mass A (mg) of the water droplets remaining on the glass plate is measured, and the percentage of mass A to the total mass of the ion-exchanged water used is defined as the liquid remaining rate.

[0049] The method for measuring the liquid remaining rate described above will be explained in more detail. First, in an environment of temperature 22±2°C and humidity 60±5%RH, a glass plate with a thickness of 2 mm, 10 cm square and flat surface (hereinafter, this is also referred to as the lower glass plate) is placed horizontally on a table, and 49 drops of 1 mg x 49 drops of ion-exchanged water of 49 mg are dropped and arranged in a 5 cm square frame in the center of the lower glass plate. Next, a sheet for absorbent articles cut into 5 cm squares is placed so that its first surface is in contact with each water drop on the lower glass plate, and in this state, a glass plate for loading having the same dimensions as the lower glass plate is further placed on the sheet and left to stand for 1 minute under a load of 0.8 kPa. Then, the glass plate for loading and the sheet for absorbent articles are removed, and the mass A (mg) of the water drops remaining on the lower glass plate is measured, and the percentage of the mass A to the total mass (49 mg) of the ion-exchanged water used is taken as the liquid remaining rate (%). If it is not possible to cut the absorbent sheet to a square measuring 5 cm square, cut the sheet into the largest possible square and measure it against a 1 cm square glass plate. 2 Place 2 drops of 1 mg of ion-exchanged water per container and determine the liquid remaining rate using the method described above.

[0050] The sheet 1 having the above-mentioned configuration can be suitably manufactured, for example, by the following method. First, a fiber web or nonwoven fabric containing synthetic fibers that constitute the fiber aggregate of the first fiber layer 11, and a fiber web, nonwoven fabric, or paper containing cellulose fibers that constitute the fiber aggregate of the second fiber layer 12 are each manufactured by a known web forming means or nonwoven fabric forming means. Then, the fiber aggregate of the first fiber layer 11 and the fiber aggregate of the second fiber layer 12 are stacked while being transported in the same direction to form a laminate.

[0051] In order to configure each fiber constituting the first fiber layer 11 and the second fiber layer 12 so as to satisfy the above-mentioned contact angle with water, for example, the surface of the synthetic fiber contained in the first fiber layer 11 may be subjected to a hydrophilic treatment in advance, or the fiber web or nonwoven fabric for constituting the first fiber layer 11 may be subjected to a hydrophilic treatment after formation. In addition, as the fibers constituting the second fiber layer 12, highly hydrophilic fibers such as pulp fibers may be used, or the surface of the fibers constituting the second fiber layer 12 may be subjected to a hydrophilic treatment, or the fiber web or nonwoven fabric may be subjected to a hydrophilic treatment after formation. In addition, the degree of hydrophilic treatment of the fiber web or nonwoven fabric constituting the first fiber layer 11 and the second fiber layer 12 may be appropriately adjusted so as to satisfy the desired contact angle.

[0052] Next, the laminate is introduced between the first roll and the second roll, and the embossed portion 15 is formed on the laminate, so that one side of the sheet is shaped into an uneven shape. The first roll has a plurality of convex portions on its circumferential surface, which are arranged in a scattered manner or the like and have a pattern complementary to the desired uneven shape pattern, so that the convex portions have a shape corresponding to the embossed portion 15 to be formed and the spaces between the convex portions are recessed. The second roll is an anvil roll with a smooth circumferential surface, which is arranged so that its axis and the axis of the first roll are parallel to each other and is arranged to abut against the circumferential surface of the first roll. The laminate is introduced between these rolls, and the laminate is pressed between the first roll and the anvil roll under non-heating or heating. From the viewpoint of easily forming unevenness on the first fiber layer side, it is preferable that the laminate is introduced so that the surface on the first fiber layer 11 side faces the circumferential surface of the first roll. In this case, the convex portions located on the peripheral surface of the first roll are intended to be positions where the embossed portions 15 are to be formed, and the concave portions located on the peripheral surface of the first roll are intended to be positions where the convex portions 18 are to be formed. In this way, it is possible to obtain the absorbent sheet of the present invention in which the first surface F is shaped to have convex and concave portions.

[0053] In the above-mentioned process, for example, at least one of the convex portion of the first roll and the surface of the anvil roll is heated, and the laminate is pressed between the first roll and the anvil roll under heating to form the embossed portion 15. In this case, the fiber layers 11 and 12 are bonded by fusion at the position where the embossed portion 15 is formed. Such a method of forming the embossed portion 15 is known as a heat roll method. The pressure conditions and heating temperature in the first roll and the anvil roll when forming the embossed portion 15 on the laminate can be appropriately changed depending on the type of fiber constituting each fiber layer, but the pressure conditions, expressed in terms of linear pressure, can be preferably 300 N / cm or more, more preferably 600 N / cm or more, and preferably 1500 N / cm or less, and more preferably 1200 N / cm or less. The heating conditions, under the above pressure conditions, can be preferably 100°C or more, more preferably 110°C or more, and preferably 150°C or less, and more preferably 140°C or less.

[0054] As a method for forming the embossed portion 15 other than the heat roll, for example, an embossing method such as ultrasonic pressure or laser heating pressure can be adopted. In this case, the pressure condition is preferably 200 N / cm or more, more preferably 300 N / cm or more, and preferably 500 N / cm or less, more preferably 400 N / cm or less, expressed in terms of linear pressure. When heating is required, the heating temperature can be in the above-mentioned range.

[0055] Furthermore, when manufacturing a sheet 1 having an embossed portion 15 only in the first fiber layer 11 and no embossed portion in the second fiber layer 12, for example, a nonwoven fabric that has been embossed in advance, such as a spunbond nonwoven fabric, may be used as the constituent material for the first fiber layer 11, and a fiber web or nonwoven fabric that has not been embossed may be used as the constituent material for the second fiber layer 12, and these fiber layers may be joined together using a joining means such as an adhesive.

[0056] The above-mentioned absorbent article sheet 1 can be preferably used as a component of an absorbent article. An absorbent article typically includes a liquid-permeable top sheet, a liquid-impermeable back sheet, and a liquid-retentive absorbent between these sheets. The absorbent article sheet can be used as a top sheet. In addition to or instead of this, the absorbent article sheet can be used as a component of an absorbent article other than the top sheet, back sheet, and absorbent. In either case, the absorbent article sheet 1 is preferably arranged so that the first fiber layer 11 side, i.e., the first surface F, faces the body of the wearer of the absorbent article, forming the skin contact surface of the absorbent article. This configuration makes it possible to efficiently transfer body fluid that has migrated to the second fiber layer side through the first fiber layer to a member located on the non-skin facing side of the second fiber layer, such as an absorbent.

[0057] An absorbent article including the absorbent article sheet 1 is mainly used to absorb and retain excreted body fluids such as urine, sweat, and menstrual blood. Such absorbent articles include, but are not limited to, pants-type or open-type disposable diapers, sanitary napkins, and incontinence pads, and broadly include articles used to absorb fluids discharged from the human body. As described above, the absorbent article sheet 1 has high sheet transferability of body fluids and is unlikely to remain on the wearer's skin, so it is preferable that the absorbent article sheet 1 is disposed at a portion where the absorbent article and the wearer's skin come into direct contact. Examples of components disposed at such positions include, but are not limited to, one or more of the top sheet, waist gathers and three-dimensional leakproof gathers in disposable diapers, top sheet, sweat-absorbing sheets that constitute the skin-facing surfaces of the ventral and dorsal waist flaps, etc.

[0058] From the viewpoint of improving the feel on the first surface F of the sheet 1, the synthetic fibers constituting the first fiber layer 11 preferably have a fiber diameter of 10 μm or more, more preferably 15 μm or more, and preferably 30 μm or less, more preferably 25 μm or less, from the viewpoint of simultaneously increasing the capillary force of the first fiber layer 11 to facilitate liquid transfer to the second fiber layer 12 and preventing water retention in the first fiber layer 11 that contacts the skin. In addition, from the viewpoint of ensuring the breathability of the second fiber layer 12, reducing the surface area of ​​the fibers, and preventing absorbed body fluid from returning to the first fiber layer 11 side, the cellulose fibers constituting the second fiber layer 12 preferably have a fiber diameter of 10 μm or more, more preferably 15 μm or more, and preferably 45 μm or less, more preferably 40 μm or less. These fiber diameters can be determined, for example, by measuring the maximum diameter of a fiber cross section perpendicular to the fiber length direction at one point per fiber using a scanning electron microscope or the like for 100 fibers as measurement objects, and taking the arithmetic average value of the measured values.

[0059] The basis weight of the sheet 1 for absorbent articles is appropriately selected depending on the specific use of the absorbent article, and is generally preferably 8 g / m 2 More preferably, 15 g / m 2 More preferably, it is 50 g / m 2 More preferably, 40 g / m 2 The basis weights of the first fiber layer 11 and the second fiber layer 12 constituting the absorbent article sheet 1 are preferably as high as possible, from the viewpoint of ensuring a distance between the highly hydrophilic second fiber layer 12 and the wearer's skin to enhance the dry feeling of the surface of the sheet 1, and from the viewpoint of enhancing the liquid absorption and liquid retention of the second fiber layer 12. More specifically, each of the first fiber layer 11 and the second fiber layer 12 is preferably independently 4 g / m 2 More preferably, 9 g / m 2 More than 30g / m 2 The following is realistic.

[0060] When continuous linear embossed lines 15A, 15B are formed as the embossed portion 15, the distance W1 (see FIG. 1(a)) between adjacent first embossed lines 15A formed on the sheet 1 is preferably 3 mm or more, more preferably 5 mm, and is preferably 15 mm or less, more preferably 12 mm or less. The distance W2 (see FIG. 1(a)) between adjacent second embossed lines 15B can be set in the same range as the distance W1 described above.

[0061] Furthermore, when forming scattered embossed portions 15, the interval W5 (see FIG. 1(b)) between embossed portions 15 along the extension direction of embossed portion row 15C composed of embossed portions 15 formed on sheet 1 is preferably 1 mm or more, preferably 8 mm or less, and more preferably 5 mm or less. The interval W6 (see FIG. 1(b)) between adjacent embossed portion rows 15C can be set to the same range as the interval W5 described above.

[0062] Although the present invention has been described based on the preferred embodiment, the present invention is not limited to the above embodiment. EXAMPLES

[0063] The present invention will be described in more detail below with reference to examples, but the scope of the present invention is not limited to these examples.

[0064] [Examples 1 and 2] The material constituting the first fiber layer 11 was an air-through nonwoven fabric (basis weight of Example 1: 15.2 g / m2) containing 90% by mass of a core-sheath type composite fiber (contact angle with water: 76.1°) that had been hydrophilically treated with a PET core and a PE sheath as synthetic fibers, and 10% by mass of Tencel (registered trademark, contact angle with water: 41.7°) as cellulose fibers. 2 , Example 2 has a basis weight of 14.6 g / m 2 ) was used. The second fiber layer 12 is made of a wet-laid paper (basis weight 20 g / m) containing 85% by mass of pulp fiber as cellulose fiber and 15% by mass of core-sheath type composite fiber (contact angle with water: 97.7°) with a PET core and a PE sheath as synthetic fiber that has not been hydrophilized. 2 These constituent materials were laminated to form a laminate. This laminate was subjected to ultrasonic embossing from the first fiber layer 11 side to form a sheet for absorbent articles (basis weight of Example 1: 35.2 g / m2) with a concave-convex shape on the first surface F. 2 , Example 2: basis weight 34.6 g / m 2 ) was prepared. As shown in Figures 1(b) and 2(a), this sheet had scattered embossed portions 15 formed on the sheet plane, had solid protrusions 18, and the first fiber layer 11 and the second fiber layer 12 were joined by the embossed portions 15. The synthetic fibers in the first fiber layer 11 were made hydrophilic by a hydrophilization treatment in which a fiber oil was applied to the fiber surface during the manufacturing process of the synthetic fibers. The thickness T1 of the first fiber layer 11, the Klemm water absorption height C1 of the first fiber layer 11, and the Klemm water absorption height C2 of the second fiber layer 12 measured by the above-mentioned method are shown in Table 1 below. The synthetic fibers contained in the first fiber layer 11 and the second fiber layer 12 each contain the same polymer component. In this sheet, the embossed portion formed in the first fiber layer 11 was located on the second fiber layer 12 side.

[0065] Example 3 The constituent material of the first fiber layer 11 is an airlaid nonwoven fabric (basis weight 14.6 g / m) containing 80 mass% of synthetic fibers (a core-sheath type composite fiber (contact angle with water: 97.7°) with a PET core and a PE sheath that has not been hydrophilized, and containing 20 mass% of pulp fiber as cellulose fiber. 2 1(b) and 2(a), having solid protrusions 18, and having a concave-convex shape formed on a first surface F, was used in the same manner as in Example 1, except that a sheet for absorbent articles (basis weight 34.6 g / m 2 ) was prepared. The thickness T1 of the first fiber layer 11, the Klemm water absorption height C1 of the first fiber layer 11, and the Klemm water absorption height C2 of the second fiber layer 12 measured by the above-mentioned method are shown in Table 1 below. The synthetic fibers contained in the first fiber layer 11 and the second fiber layer 12 each contain the same polymer component. In this sheet, the embossed portion formed in the first fiber layer 11 was located on the second fiber layer 12 side.

[0066] Example 4 The first fiber layer 11 is made of an air-through nonwoven fabric (basis weight 14.3 g / m) containing 90% by mass of a synthetic fiber with a PET core and a PE sheath that has been hydrophilically treated (contact angle with water: 76.1°) and 10% by mass of Tencel (registered trademark, contact angle with water: 42.5°) as a cellulose fiber. 2 ), and the first fiber layer 11 and the second fiber layer 12 were bonded together by forming embossed portions 15 by ultrasonic embossing and bonding each fiber layer with a hot melt adhesive. Other than that, similar to Example 1, a sheet for absorbent articles (basis weight 34.3 g / m) having the configuration shown in Fig. 1(b) and Fig. 2(a), having solid protrusions 18, and having a concave-convex shape formed on the first surface F was used. 2 ) was prepared. The thickness T1 of the first fiber layer 11, the Klemm water absorption height C1 of the first fiber layer 11, and the Klemm water absorption height C2 of the second fiber layer 12 measured by the above-mentioned method are shown in Table 1 below. The synthetic fibers contained in the first fiber layer 11 and the second fiber layer 12 each contain the same polymer component. In this sheet, the embossed portion formed in the first fiber layer 11 was located on the second fiber layer 12 side.

[0067] Example 5 The material constituting the first fiber layer 11 is an air-through nonwoven fabric (basis weight 14.5 g / m) containing 90% by mass of a core-sheath type composite fiber (contact angle with water: 76.1°) that has been hydrophilically treated with a PET core and a PE sheath as a synthetic fiber, and 10% by mass of Tencel (registered trademark, contact angle with water: 43.4°) as a cellulose fiber. 2The second fiber layer 12 was made of an airlaid nonwoven fabric (basis weight 25 g / m2) containing 80% by mass of pulp fiber as cellulose fiber and 15% by mass of core-sheath type composite fiber (contact angle with water: 97.7°) with a PET core and PE sheath as synthetic fiber that had not been hydrophilized. 2 ) was used. In addition, similarly to Example 1, a sheet for absorbent articles (basis weight 34.5 g / m) having the configuration shown in FIG. 1(b) and FIG. 2(a), having solid protrusions 18, and having a concave-convex shape formed on the first surface F was used. 2 ) was prepared. The thickness T1 of the first fiber layer 11, the Klemm water absorption height C1 of the first fiber layer 11, and the Klemm water absorption height C2 of the second fiber layer 12 measured by the above-mentioned method are shown in Table 1 below. The synthetic fibers contained in the first fiber layer 11 and the second fiber layer 12 each contain the same polymer component. In this sheet, the embossed portion formed in the first fiber layer 11 was located on the second fiber layer 12 side.

[0068] Example 6 The first fiber layer 11 is made of an air-through nonwoven fabric (basis weight 25 g / m2) containing 100% by mass of a synthetic fiber with a core-sheath type composite fiber (contact angle with water: 76.1°) that has been hydrophilically treated with a PET core and a PE sheath. 2 The second fiber layer 12 was made of a wet-laid paper (basis weight 40 g / m2) containing 90% by mass of pulp fiber as cellulose fiber and 10% by mass of core-sheath type composite fiber (contact angle with water: 97.7°) with a PET core and a PE sheath as synthetic fiber that had not been hydrophilized. 2 ) was used. In addition, similarly to Example 1, a sheet for absorbent articles (basis weight 65 g / m) having the configuration shown in FIG. 1(b) and FIG. 2(a), having solid protrusions 18, and having a concave-convex shape formed on the first surface F was used. 2 ) was prepared. The thickness T1 of the first fiber layer 11, the Klemm water absorption height C1 of the first fiber layer 11, and the Klemm water absorption height C2 of the second fiber layer 12 measured by the above-mentioned method are shown in Table 1 below. The synthetic fibers contained in the first fiber layer 11 and the second fiber layer 12 each contain the same polymer component. In this sheet, the embossed portion formed in the first fiber layer 11 was located on the second fiber layer 12 side.

[0069] Comparative Example 1 The first fiber layer 11 is made of an air-through nonwoven fabric (basis weight 15 g / m2) containing 80% by mass of synthetic fibers with a PET core and a PE sheath that have not been hydrophilized (contact angle with water: 97.7°) and 20% by mass of Tencel (registered trademark) as cellulose fibers. 2 ), and a fiber web (basis weight 15 g / m) containing 100% Tencel (registered trademark) was used as the constituent material of the second fiber layer 12. 2 ) were used, and these were integrated by hydroentanglement to produce a sheet for absorbent articles (basis weight 30 g / m 2 ) was prepared. This sheet is a so-called spunlace nonwoven fabric, and no embossed portions 15 are formed in each fiber layer, and no uneven structure is formed on the first surface F. The thickness T1 of the first fiber layer 11, the Klemm water absorption height C1 of the first fiber layer 11, and the Klemm water absorption height C2 of the second fiber layer 12, measured by the above-mentioned method, are shown in Table 1 below.

[0070] Comparative Example 2 The first fiber layer 11 is made of a spunbond nonwoven fabric (basis weight 10 g / m2) containing 100% by mass of polypropylene fiber (contact angle with water: 108.2°) that has not been hydrophilized. 2 ), and a spunbond nonwoven fabric containing 100 mass % of hydrophilically treated polypropylene fiber (contact angle with water: 74.8°) as the constituent material of the second fiber layer 12. These were integrated by applying a hot melt adhesive between them to form a sheet for absorbent articles (basis weight 30 g / m 2 ) was prepared. In this sheet, the embossed portion 15 was formed only in the first fiber layer 11, and the uneven structure was formed on the first surface F. In this sheet, the embossed portion formed in the first fiber layer 11 was located on the second fiber layer 12 side. The thickness T1 of the first fiber layer 11, the Klemm water absorption height C1 of the first fiber layer 11, and the Klemm water absorption height C2 of the second fiber layer 12, which were measured by the above-mentioned method, are shown in Table 1 below.

[0071] [Evaluation of remaining amount of liquid and remaining rate of liquid] The sheets of the examples and comparative examples were evaluated for the amount of remaining liquid and the liquid remaining rate under conditions of a temperature of 22±2°C and a humidity of 60±5%RH. In detail, the above-mentioned method for measuring the liquid remaining rate of a sheet for absorbent articles was followed, and the mass A (mg) of the water droplets remaining on the lower glass plate was taken as the amount of remaining liquid in this evaluation, and the percentage of mass A to the total mass (49 mg) of the ion-exchanged water used was taken as the liquid remaining rate (%). The results are shown in Table 1. The smaller the mass (mg) of the ion-exchanged water remaining on the lower glass plate and the smaller the liquid remaining rate, the better the liquid transferability to the sheet, i.e., the less likely body fluids such as sweat to remain on the wearer's skin.

[0072] [Table 1]

[0073] As shown in Table 1, the absorbent article sheets of the examples have a lower amount and percentage of residual liquid compared to the comparative sheets. In particular, by controlling the thickness of the first fiber layer 11 to a predetermined range, the amount and percentage of residual liquid can be further reduced. Therefore, an absorbent article having the absorbent article sheet of the present invention arranged on the skin contact surface is less likely to retain body fluids such as sweat on the wearer's skin, and skin troubles caused by body fluids remaining on the skin can be reduced. [Explanation of symbols]

[0074] 1. Sheets for absorbent articles 2. Synthetic Fibers 3. Cellulose Fibers 11 First fiber layer 12 Second fiber layer 15 Embossed section 17 Recess 18 Convex

Claims

1. a first fibrous layer including a first surface and including synthetic fibers; a second fiber layer including a second surface that is a surface opposite to the first surface and including 75% by mass or more of cellulose fibers; the first fibrous layer comprises fibers having a contact angle with water of less than 90°; An embossed portion is formed in the first fiber layer, a concave-convex shape having a plurality of concave portions formed by the embossed portion and convex portions formed between the concave portions is formed on the first surface, the Klemm water absorption height of the second fiber layer measured in accordance with JIS P8141 is 4 cm or more; the Klemm water absorption height of the first fiber layer measured in accordance with JIS P8141 is 3 cm or more lower than the Klemm water absorption height of the second fiber layer measured in accordance with JIS P8141; A sheet for absorbent articles, wherein when the first fiber layer contains cellulose fibers, the proportion of the cellulose fibers contained in the first fiber layer is lower than the proportion of the cellulose fibers contained in the second fiber layer.

2. The absorbent article sheet according to claim 1 , wherein the first fiber layer and the second fiber layer are joined together by the embossed portion.

3. The sheet for absorbent articles according to claim 1 or 2, wherein the first fibrous layer further comprises cellulose fibers.

4. the cellulose fibers constituting the second fibrous layer are pulp fibers, The sheet for absorbent articles according to any one of claims 1 to 3, wherein the second fibrous layer is paper.

5. The sheet for absorbent articles according to any one of claims 1 to 4, wherein the first fibrous layer further comprises either regenerated cellulose fibers or semi-synthetic cellulose fibers.

6. the second fibrous layer further comprises synthetic fibers; The absorbent sheet according to any one of claims 1 to 5, wherein the synthetic fibers contained in the first fiber layer and the synthetic fibers contained in the second fiber layer each contain the same polymer component.

7. The sheet for absorbent articles according to any one of claims 1 to 6, wherein the thickness of the first fiber layer under a load of 49 Pa is 600 µm or less.

8. The sheet for absorbent articles according to any one of claims 1 to 7, wherein the liquid remaining rate is 20% or less.

9. An absorbent article sheet as described in any one of claims 1 to 8, wherein the Klemm absorption height of the first fiber layer measured in accordance with JIS P8141 is 1 cm or less.

10. The absorbent article sheet according to any one of claims 1 to 9 is provided, The sheet is used as a top sheet or a sweat-absorbing sheet in an absorbent article.

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