Absorbent articles

Abstract

To provide an absorbent article capable of sufficiently exerting a function of a water-soluble functional powder.SOLUTION: An absorbent article of the present invention includes a sheet (7) in which a water-soluble functional powder (PF) is fixed. An amount of the functional powder (PF) fixed in the sheet (7) is equal to or greater than 50 g / m2, and a residual ratio of the functional powder (PF) in a permeation falling test is equal to or greater than 50%.SELECTED DRAWING: Figure 3

Description

Technical Field

[0001] The present invention relates to an absorbent article including a sheet to which water-soluble functional powder is fixed. Background Art

[0002] In absorbent articles such as sanitary napkins and panty liners, absorbent articles equipped with water-soluble functional agents are known in order to improve absorption performance and impart various functions such as skin care effects. For example, Patent Document 1 discloses an absorbent article including an absorber containing a superabsorbent polymer and an osmotic pressure adjusting agent (an example of a water-soluble functional agent) that adjusts the osmotic pressure of blood cell components in blood. Prior Art Documents Patent Documents

[0003] Patent Document 1 Japanese Unexamined Patent Publication No. 2022-13798 Summary of the Invention Problems to be Solved by the Invention

[0004] In conventional absorbent articles equipped with such a water-soluble functional agent, when a powdery functional agent is used as the water-soluble functional agent, the functional agent is placed in a predetermined position on various sheets constituting the absorbent article in a powdery state. However, since the powdery water-soluble functional agent (hereinafter such a functional agent is referred to as "water-soluble functional powder") cannot be fixed at a predetermined position on the sheet, the functional powder may move from the predetermined position due to the wearer's movement or the like while the absorbent article is worn, and there is a risk that the function of the functional powder cannot be fully exhibited.

[0005] The present invention has been made in view of such problems, and an object of the present invention is to provide an absorbent article that can sufficiently exhibit the function of water-soluble functional powder. Means for Solving the Problems

[0006] As a result of intensive studies conducted to achieve the above object, the present inventors have found that by setting the amount of water-soluble functional powder fixed to a sheet and the residual rate of the functional powder in a permeation shedding test within specific ranges respectively, it is possible to make the functional powder less likely to move from the sheet while securing an amount sufficient to exert the functions of the functional powder. The present invention has been completed based on this finding, and includes the following aspects.

[0007] (Aspect 1) An absorbent article comprising a sheet to which water-soluble functional powder is fixed, the amount of said functional powder fixed to said sheet is 50 g / m 2 or more, The absorbent article, wherein a residual rate of the functional powder in a permeation shedding test is 50% or more.

[0008] In the absorbent article of this aspect, the amount of the functional powder fixed to the sheet is not less than a certain level, and the functional powder is less likely to move from the sheet, so that the function of the water-soluble functional powder can be sufficiently exerted.

[0009] (Aspect 2) The absorbent article comprises a liquid-permeable top sheet, a liquid-impermeable back sheet, an absorber positioned between these two sheets, and an intermediate sheet positioned between the top sheet and the absorber, the absorber has a skin-facing side absorbent core positioned relatively on the skin-facing side in the thickness direction of the absorbent article, a non-skin-facing side absorbent core positioned relatively on the non-skin-facing side in the thickness direction, and a core wrap sheet wrapping the skin-facing side absorbent core and the non-skin-facing side absorbent core, The absorbent article according to embodiment 1, characterized in that the sheet on which the functional powder is fixed is located at at least one of the following positions in the thickness direction: a position on the skin-facing side of the surface sheet, a position between the surface sheet and the intermediate sheet, a position between the intermediate sheet and the core wrap sheet, a position between the core wrap sheet and the skin-facing side absorbent core, and a position between the skin-facing side absorbent core and the non-skin-facing side absorbent core.

[0010] In this embodiment of the absorbent article, since a sheet on which water-soluble functional powder is fixed is positioned at the above-mentioned specific location, even if the functional powder dissolves due to the wearer's menstrual fluid or other excretory fluids and leaks out from the designated area of ​​the sheet, the dissolved functional powder (i.e., liquid functional agent) migrates to the absorbent material or absorbent core located on the non-skin-facing side and is retained there, thereby allowing it to re-exert its function as a functional agent. Therefore, in this embodiment of the absorbent article, the function of the water-soluble functional powder can be maintained over a long period of time.

[0011] (Aspect 3) The sheet on which the functional powder is fixed includes a fiber sheet, An absorbent article according to embodiment 1 or 2, characterized in that the inter-fiber distance of the constituent fibers of the fiber sheet is 100 μm or less.

[0012] In this embodiment, the absorbent article includes a sheet on which functional powder is fixed, which contains a fibrous sheet having a specific inter-fiber distance. This makes it difficult for the functional powder to move through the constituent fibers of the fibrous sheet. Specifically, when the functional powder has a particle size of 100 μm or more, the relationship between the particle size of the functional powder and the inter-fiber distance of the constituent fibers of the fibrous sheet makes it difficult for the functional powder to move through the constituent fibers of the fibrous sheet. Even when the functional powder has a particle size of less than 100 μm, the functional powder is forced to move in a meandering manner, colliding with the constituent fibers of the fibrous sheet, and as a result, it is difficult for the functional powder to move through the constituent fibers of the fibrous sheet. Therefore, in this embodiment, it is even more difficult for functional powder exceeding a predetermined amount to move from the sheet, thus enabling the water-soluble functional powder to exert its function more reliably.

[0013] (Aspect 4) The absorbent article according to embodiment 3, characterized in that the volume median particle size (D50) of the functional powder is 50 μm or larger.

[0014] In this embodiment of the absorbent article, the interfiber distance of the constituent fibers of the fiber sheet and the volume median particle size of the functional powder are both within a specific range. Therefore, due to the size relationship between the particle size of the functional powder and the interfiber distance of the constituent fibers of the fiber sheet, the functional powder is even less likely to move through the constituent fibers of the fiber sheet. Consequently, the absorbent article in this embodiment can more reliably exhibit the function of the water-soluble functional powder.

[0015] (Appendix 5) The sheet on which the functional powder is fixed includes a fiber sheet, The absorbent article according to any of embodiments 1 to 4, characterized in that the functional powder is fixed to the fiber sheet by an adhesive.

[0016] In this embodiment of the absorbent article, the water-soluble functional powder is fixed to the fiber sheet by an adhesive, making it difficult for the functional powder to fall off the fiber sheet. Furthermore, since at least some of the constituent fibers of the fiber sheet are joined and fixed together by the adhesive, the distance between the constituent fibers of the fiber sheet does not change easily, and the functional powder does not easily move through the constituent fibers of the fiber sheet. As a result, the absorbent article in this embodiment can more reliably exert the function of the water-soluble functional powder.

[0017] (Aspect 6) The sheet on which the functional powder is fixed includes two sheet members that overlap in the thickness direction of the absorbent article. The absorbent article according to any of embodiments 1 to 5, characterized in that the functional powder is sandwiched between the two sheet members.

[0018] In this embodiment of the absorbent article, the water-soluble functional powder is sandwiched between two sheet members, making it even more difficult for the water-soluble functional powder to move away from the sheets. As a result, the absorbent article in this embodiment can more reliably exert the function of the water-soluble functional powder.

[0019] (Aspect 7) The sheet on which the functional powder is fixed has a joint portion formed by joining the two sheet members, and an unjointed portion that is demarcated as a portion surrounded by the joint portion in a plan view. The absorbent article according to embodiment 6, characterized in that the functional powder is arranged in the non-jointed portion.

[0020] In this embodiment of the absorbent article, the water-soluble functional powder is placed in a closed space between two sheet members, specifically in the non-jointed portion surrounded by the joint portion. This makes it even more difficult for the functional powder to move away from the sheets. As a result, the absorbent article in this embodiment can more effectively exert the function of the water-soluble functional powder.

[0021] (Pattern 8) The sheet on which the functional powder is fixed has a plurality of non-jointed portions. The absorbent article according to embodiment 7, characterized in that the functional powder is dispersed in each of the plurality of non-jointed portions.

[0022] In this embodiment of the absorbent article, since the water-soluble functional powder is dispersed in each of the multiple non-jointed areas, the functional powder can be positioned more precisely and less likely to move. As a result, the absorbent article in this embodiment can more effectively exert the function of the water-soluble functional powder.

[0023] (Aspect 9) The absorbent article has a longitudinal direction and a width direction when viewed from above. The absorbent article according to embodiment 8, characterized in that the sheet on which the functional powder is fixed has a plurality of non-joint portions arranged in the longitudinal direction, and the joint portions between adjacent non-joint portions are arranged to extend in the width direction.

[0024] In this embodiment, the absorbent article has multiple non-jointed portions where water-soluble functional powder is placed, arranged in a line along the longitudinal direction of the absorbent article, and the joints between adjacent non-jointed portions are arranged to extend in the width direction of the absorbent article. As a result, the water-soluble functional powder can be placed in an appropriate position and is less likely to move, and the joints extending in the width direction of the absorbent article function as deformation guides (i.e., function as base points for bending in the longitudinal direction), making it easier to deform to follow the shape of the wearer's body. As a result, the absorbent article in this embodiment can more accurately exert the function of the water-soluble functional powder.

[0025] (Aspect 10) The functional powder is characterized by having a solubility of 8 g / 100 g H2O or more in 100 g of ion-exchanged water at 25°C, and is an absorbent article according to any of embodiments 1 to 9.

[0026] The absorbent article in this embodiment has a solubility such that the water-soluble functional powder does not completely dissolve in a small amount of excretory fluid (for example, the amount of a single excretion), thus allowing the functional powder to exert its effects over a longer period of time. [Effects of the Invention]

[0027] According to the present invention, it is possible to provide an absorbent article that can fully exhibit the functionality of water-soluble functional powders. [Brief explanation of the drawing]

[0028] [Figure 1] Figure 1 is a schematic plan view of a sanitary napkin 1 in its unfolded state, which is one embodiment of the present invention. [Figure 2] Figure 2 is a schematic cross-sectional view of sanitary napkin 1. [Figure 3] Figure 3 is a schematic cross-sectional view of a sheet 7 on which a water-soluble functional powder is immobilized, used in a sanitary napkin 1. [Figure 4] Figure 4 is a schematic plan view illustrating variations in the arrangement of the joint portion 73 and non-joint portion 74 of a sheet 7 on which a water-soluble functional powder is fixed. [Modes for carrying out the invention]

[0029] Hereinafter, preferred embodiments of the absorbent article of the present invention will be described in detail with reference to the drawings.

[0030] Figure 1 is a schematic plan view of a sanitary napkin 1 in an unfolded state, which is one embodiment of the absorbent article of the present invention, and Figure 2 is a schematic cross-sectional view of the sanitary napkin 1. In this specification, unless otherwise specified, "viewing an object (e.g., an absorbent article, etc.) placed on a horizontal surface in an unfolded state from the vertically upward side (the surface sheet side in the case of an absorbent article) in the thickness direction of the object" is simply referred to as "plan view." Furthermore, in the thickness direction of an absorbent article in an unfolded state, "the side that is relatively proximal to the wearer's skin when the absorbent article is worn" is referred to as the "skin-facing side," and "the side that is relatively distal to the wearer's skin when the absorbent article is worn" is referred to as the "non-skin-facing side."

[0031] [Sanitary napkins] As shown in Figure 1, a sanitary napkin 1, which is one embodiment of the present invention, has a longitudinal direction L and a width direction W in a plan view, and further has an elongated external shape in which two longitudinal edges protrude outward in an arc shape in the longitudinal direction. However, the external shape of the sanitary napkin 1 in a plan view is not limited to this form, and any shape (for example, oval, rectangular, hourglass shape, etc.) can be adopted depending on the various uses and modes of use.

[0032] As shown in Figure 2, the sanitary napkin 1 has as its basic structure a liquid-permeable surface sheet 2 that forms the skin-facing side of the sanitary napkin 1 in the thickness direction T, a back sheet 3 that forms the non-skin-facing side of the sanitary napkin 1, and an absorbent core 4 located between these two sheets. Furthermore, in this embodiment, as shown in Figures 1 and 2, the sanitary napkin 1 further comprises a pair of side sheets 5, 5 positioned at both ends in the width direction W of the sanitary napkin 1 and extending in the longitudinal direction L on the skin-facing side of the surface sheet 2, with the inner ends in the width direction W standing up to form a leak-proof wall when the sanitary napkin 1 is worn; an intermediate sheet 6 positioned between the surface sheet 2 and the absorbent 4 and having a function such as diffusing excretory fluid that has permeated the surface sheet 2 in the planar direction; a sheet 7 positioned between the intermediate sheet 6 and the absorbent 4 and having a water-soluble functional powder fixed to it; and an adhesive part (not shown) positioned on the non-skin-facing surface of the back sheet 3 for adhesively fixing the sanitary napkin 1 to the inner surface of the wearer's underwear or other clothing.

[0033] In this embodiment, the absorbent body 4 includes a skin-facing side absorbent core 41 located relatively on the skin-facing side in the thickness direction T, a non-skin-facing side absorbent core 42 located relatively on the non-skin-facing side in the thickness direction T, and a core wrap sheet 43 that encloses the skin-facing side absorbent core 41 and the non-skin-facing side absorbent core 42.

[0034] Furthermore, in the sanitary napkin 1, the sheet 7 on which the water-soluble functional powder is fixed has a functional powder content of 50 g / m². 2 The sheet meets the above requirements, and also satisfies the specific requirement that the remaining functional powder in the permeation detachment test is 50% or more.

[0035] In this way, by fixing the water-soluble functional powder to the sheet 7 such that the amount of water-soluble functional powder fixed to the sheet 7 and the remaining rate of the functional powder in the permeation shedding test are both within the specified ranges described above, it is possible to ensure an amount sufficient to fully exhibit the function of the functional powder while making it difficult for the functional powder to move from the sheet 7. As a result, the sanitary napkin 1 of this embodiment can fully exhibit the function of the water-soluble functional powder.

[0036] In this specification, "water-soluble" means that the solubility (g / 100gH2O) in 100g of deionized water at 25°C is 1g / 100gH2O or higher.

[0037] Furthermore, the "amount of water-soluble functional powder fixed to the sheet" can be measured, for example, according to the following <Method for measuring the amount of functional powder fixed to the sheet>.

[0038] <Method for measuring the amount of functional powder fixed to a sheet> (1) Remove the surface sheet, etc., from the absorbent material and take out the sheet on which the functional powder is fixed. (2) Cut out a square test piece of a predetermined size (for example, 50 mm x 50 mm) from the portion of the sheet on which the functional powder is fixed. At this time, the size of the test piece will be the size that allows for cutting out the largest possible square test piece, depending on the size of the portion of the sheet on which the functional powder is fixed. (3) The functional powder is recovered from the cut test piece using physical means (e.g., vibration means, etc.) and / or chemical means (e.g., a solvent capable of dissolving adhesives, etc.). If foreign matter other than the functional powder (e.g., fiber fragments, etc.) is present, the foreign matter is removed using tweezers or the like while using magnifying observation means such as a microscope or a simple magnifying glass, and only the functional powder is recovered. (4) Measure the mass (g) of the recovered functional powder and use this to measure the area (m²) of the test specimen in plan view. 2 By dividing by ), the "amount of water-soluble functional powder fixed to the sheet" (g / m²) 2 ) obtain.

[0039] Furthermore, the "remaining rate of functional powder in the permeation detachment test" of a sheet on which functional powder is fixed can be measured according to the following <permeation detachment test>.

[0040] <Transmission and Shedding Test> (1) Remove the surface sheet, etc., from the absorbent material and take out the sheet on which the functional powder is fixed. (2) Cut out two square test pieces of a predetermined size (e.g., 50 mm x 50 mm) from the portion of the sheet on which the functional powder is fixed. The size of the test pieces will be determined based on the size of the portion of the sheet on which the functional powder is fixed, so as to be the largest possible square test piece that can be cut out. The two test pieces will be the same size. (3) The functional powder is recovered from one of the two cut test pieces using physical means (e.g., vibration means, etc.) and / or chemical means (e.g., a solvent capable of dissolving adhesives, etc.). If foreign matter other than the functional powder (e.g., fiber fragments, etc.) is present, the foreign matter is removed using tweezers or the like while using magnifying observation means such as a microscope or a simple magnifying glass, and only the functional powder is recovered. (4) Measure the mass (g) of the recovered functional powder and define this as the initial content (g) of the functional powder. (5) Measure the mass (g) of the other of the two test pieces cut out in (2) above, and set this as the initial mass (g) of the test piece. (6) The test specimen, whose initial mass has been measured, is placed on a metal plate whose angle can be adjusted. (7) The functional powder is removed from the test specimen by tilting the metal plate at a 45° angle. (8) The mass (g) of the test specimen after the functional powder has been removed is measured, and this is subtracted from the initial mass of the test specimen to obtain the amount (g) of the functional powder removed. (9) Subtract the amount of functional powder lost (g) from the initial amount of functional powder (g) to obtain the remaining amount of functional powder (g). Divide this by the initial amount of functional powder (g) and multiply by 100 to obtain the "remaining rate of functional powder" (%).

[0041] The sanitary napkin 1 of this embodiment is not limited to the configuration described above, as long as it includes a sheet on which a water-soluble functional powder is fixed. For example, it may not have a pair of side sheets 5, 5 or an intermediate sheet 6.

[0042] Furthermore, the placement of the sheet 7 on which the water-soluble functional powder is fixed is not limited to the position shown in Figure 2, as long as it is a position where the function of the functional powder can be exerted. However, it is preferable that the sheet 7 on which the water-soluble functional powder is fixed is positioned in the thickness direction T at least one of the following positions: a position on the skin-facing side of the surface sheet 2, a position between the surface sheet 2 and the intermediate sheet 6, a position between the intermediate sheet 6 and the core wrap sheet 43, a position between the core wrap sheet 43 and the skin-facing side absorbent core 41, and a position between the skin-facing side absorbent core 41 and the non-skin-facing side absorbent core 42. When the sheet 7 on which the water-soluble functional powder is fixed is positioned at such a specific location, even if the functional powder dissolves due to the wearer's menstrual blood or other excretory fluids and flows out from a predetermined location on the sheet 7, the dissolved functional powder (i.e., liquid functional agent) migrates to the absorbent material 4 or absorbent core located relatively on the non-skin-facing side and is retained there, thereby allowing it to exert its function as a functional agent again. Therefore, a sanitary napkin 1 in which the sheet 7 is positioned at such a specific location can exert the function of the water-soluble functional powder over a long period of time.

[0043] The components of the sanitary napkin 1 of this embodiment will be described in more detail below.

[0044] (Surface sheet) In the sanitary napkin 1, as shown in Figure 1, the surface sheet 2 has a vertically elongated shape, extending from one edge to the other edge in the longitudinal direction L of the sanitary napkin 1 in a plan view, and extending from near one edge to near the other edge in the width direction W of the sanitary napkin 1. As shown in Figure 2, the surface sheet 2 is positioned on the skin-facing side in the thickness direction T of the sanitary napkin 1 and is composed of a liquid-permeable sheet-like member (for example, a nonwoven fabric such as an air-through nonwoven fabric) that can come into contact with the wearer's skin, i.e., the surface on the skin-facing side of the sanitary napkin 1.

[0045] In a plan view, the surface sheet 2 has dimensions that are slightly larger than the absorber 4 in the longitudinal direction L and the width direction W, and is bonded to the back sheet 3 located on the non-skin-facing side at its peripheral edge.

[0046] Furthermore, there are no particular restrictions on the external shape, various dimensions, or basis weight of the surface sheet 2. Any shape, various dimensions, or basis weight can be adopted according to the desired liquid permeability, texture, flexibility, strength, etc.

[0047] (Backside sheet) In the sanitary napkin 1, the backing sheet 3 has a vertically elongated shape, extending from one edge to the other in the longitudinal direction L of the sanitary napkin 1 when viewed from above, and also extending from one edge to the other in the width direction W of the sanitary napkin 1. As shown in Figure 2, the backing sheet 3 is positioned on the non-skin-facing side in the thickness direction T of the sanitary napkin 1, forming the non-skin-facing surface of the sanitary napkin 1, and is made of a liquid-impermeable sheet-like material (for example, a resin film or SMS nonwoven fabric) that prevents menstrual blood and other excretory fluids that have permeated the absorbent material 4 from leaking out of the sanitary napkin 1.

[0048] Furthermore, there are no particular restrictions on the external shape, various dimensions, or basis weight of the backing sheet 3. Any shape, various dimensions, or basis weight can be adopted according to the desired leak-proof performance, breathability, strength, etc.

[0049] (Absorbent) In the sanitary napkin 1, as shown in Figure 1, the absorbent 4, in a plan view, extends over a wide area in the longitudinal direction L, from near one edge to near the other edge, centered on the central part of the longitudinal direction L and width direction W of the sanitary napkin 1, and also extends over a wide area in the width direction W, from near one edge to near the other edge. Furthermore, it has a vertically elongated outer shape with two longitudinal edges that project outward in an arc shape in the longitudinal direction. Also, as shown in Figure 1, the absorbent 4 has a constricted portion in the central part of the longitudinal direction L in a plan view, which has a relatively smaller width compared to other parts. Furthermore, this constricted portion has a minimum width portion, which is the minimum width of the absorbent 4, and a maximum width portion, which is the maximum width of the absorbent 4, located on the longitudinally outward side of the constricted portion.

[0050] The absorbent body 4 is positioned between the surface sheet 2 and the back sheet 3 in the thickness direction T of the sanitary napkin 1 and is formed of a predetermined absorbent material that can absorb and retain menstrual blood and other excretory fluids that have permeated through the surface sheet 2. More specifically, as shown in Figure 2, the absorbent body 4 is composed of a skin-facing side absorbent core 41 located on the skin-facing side in the thickness direction T and made of an absorbent material, a non-skin-facing side absorbent core 42 located on the non-skin-facing side in the thickness direction T and made of an absorbent material, and a core wrap sheet 43 that encloses the skin-facing side absorbent core 41 and the non-skin-facing side absorbent core 42.

[0051] The absorber 4 is not limited to this configuration; it may include a single absorbent core or have two or more absorbent cores.

[0052] In this embodiment, the skin-facing side absorbing core 41 and the non-skin-facing side absorbing core 42 can be formed from water-absorbing materials known in the art. Examples of such water-absorbing materials include hydrophilic fibers and superabsorbent polymers.

[0053] Specific examples of hydrophilic fibers include pulp fibers (e.g., crushed pulp), cotton, rayon, acetate, and other cellulose-based fibers. On the other hand, examples of superabsorbent polymers include powders or granules made from superabsorbent polymers known in this field, such as sodium acrylate copolymers, and are commonly referred to as SAP (Super Absorbent Polymer). Specific examples of superabsorbent polymers include polymers or copolymers of (meth)acrylic acid or alkali metal salts of (meth)acrylate, and preferably polymers or copolymers of sodium (meth)acrylate. In this specification, (meth)acrylic acid means acrylic acid or methacrylic acid.

[0054] Furthermore, the skin-facing side absorption core 41 and the non-skin-facing side absorption core 42 may contain only hydrophilic fibers or superabsorbent polymers, or they may contain both hydrophilic fibers and superabsorbent polymers. Also, the skin-facing side absorption core 41 and the non-skin-facing side absorption core 42 may be composed of the same composition or different compositions.

[0055] In this embodiment, the core wrap sheet 43 can be formed from a hydrophilic fiber sheet known in the art. Such a hydrophilic fiber sheet may be, for example, one formed mainly from bleached softwood kraft pulp with a basis weight of 10.0 g / m². 2 ~20.0g / m 2 Examples include tissues of a certain size.

[0056] Furthermore, there are no particular restrictions on the external shape, various dimensions, or basis weight of the absorbent 4. Any shape, various dimensions, or basis weight can be adopted according to the desired water absorption, flexibility, strength, etc.

[0057] (Intermediate sheet) In the sanitary napkin 1, the intermediate sheet 6 extends from near one edge to near the other edge in the longitudinal direction L of the sanitary napkin 1 in a plan view, and has a vertically elongated shape with a shorter width W than the surface sheet 2. As shown in Figure 2, the intermediate sheet 6 is positioned on the non-skin-facing side of the surface sheet 2 in the thickness direction T of the sanitary napkin 1, and is made of a sheet-like member (for example, a nonwoven fabric such as an air-through nonwoven fabric) having predetermined liquid diffusion and liquid permeability to diffuse menstrual blood and other excretory fluids that have permeated the surface sheet 2 in the planar direction and transfer them to the absorbent material 4 located on the non-skin-facing side.

[0058] Furthermore, there are no particular restrictions on the external shape, various dimensions, or basis weight of the intermediate sheet 6; any shape, various dimensions, or basis weight can be adopted according to the desired liquid diffusion and liquid permeability.

[0059] (Side seat) In the sanitary napkin 1, the pair of side sheets 5, 5 have a pair of strip-like external shapes that extend in the longitudinal direction L at both ends of the width direction W of the sanitary napkin 1 in a plan view, as shown in Figure 1. The pair of side sheets 5, 5 are positioned on the skin-facing side of the surface sheet 2 at both ends of the width direction W of the sanitary napkin 1, and the outer ends in the width direction W are joined to the skin-facing surface of the back sheet 3 to form fixed ends, while the inner ends in the width direction W are not joined to any component such as the surface sheet 2 and form free ends. Each of the pair of side sheets 5, 5 is formed of a hydrophilic or hydrophobic sheet-like material (for example, a hydrophilic or hydrophobic nonwoven fabric, resin film, etc.) such that when worn, the sanitary napkin 1 deforms in the longitudinal direction L, causing the inner end in the width direction W, which is the free end, to stand up, forming a leak-proof wall to prevent the excretory fluid flowing on the skin-facing surface of the surface sheet 2 from leaking out to the outside in the width direction W.

[0060] In addition, there are no particular limitations on the outer shape, various dimensions, basis weight, etc., of each of the pair of side sheets 5, 5, and any shape, various dimensions, basis weight, etc., can be adopted according to the desired leakage prevention performance and the like.

[0061] (Sheet with water-soluble functional powder fixed thereon) In the sanitary napkin 1, the sheet 7 with water-soluble functional powder fixed thereon extends in a plan view from the vicinity of one side edge to the vicinity of the other side edge in the longitudinal direction L of the sanitary napkin 1, and extends from the vicinity of one side edge to the vicinity of the other side edge in the width direction W of the sanitary napkin 1, and has a vertically elongated outer shape. As shown in FIG. 2, the sheet 7 is disposed at a position between the intermediate sheet 6 and the absorbent body 4 in the thickness direction T of the sanitary napkin 1. The sheet 7 is composed of water-soluble functional powder that exerts a predetermined function such as modifying excreted fluid like menstrual blood that has passed through the top sheet 2 and the intermediate sheet 6 when coming into contact with such excreted fluid, and a sheet member to which the functional powder is fixed.

[0062] Here, FIG. 3 is a schematic cross-sectional view of the sheet 7 with the water-soluble functional powder P F fixed thereon, which is used in the sanitary napkin 1. As shown in FIG. 3, the sheet 7 with the water-soluble functional powder P F fixed thereon has the water-soluble functional powder P F fixed in a manner sandwiched between two sheet members 71 and 72, and further, the water-soluble functional powder P F and the two sheet members 71 and 72 are respectively bonded by a hot-melt adhesive H M .

[0063] It should be noted that, in the sheet 7, there is no particular limitation on the fixing means and fixing form of the water-soluble functional powder. As described above, the functional powder may be sandwiched between at least two sheet members with or without an adhesive interposed therebetween; may be fixed on one side or both sides of a single sheet member via any fixing means (for example, structural means such as being held in the fine concave-convex structure on the surface of the sheet member, adhesive means such as an adhesive, fusion means such as ultrasonic welding, etc.); or may be fixed so as to be held inside a single sheet member.

[0064] Herein, in this specification, "functional powder fixed to the sheet" means a state in which the functional powder is retained on the sheet member to such an extent that the remaining percentage of the functional powder in the above-described permeation detachment test is 50% or more.

[0065] (Sheet material) The sheet members 71 and 72 are not particularly limited, but it is preferable that they be liquid-permeable sheet members. Examples of such liquid-permeable sheet members include fiber sheets and porous resin films, but it is preferable to use fiber sheets in terms of ease of fixing functional powders, liquid permeability, and flexibility.

[0066] Specific examples of fiber sheets include nonwoven fabrics (e.g., air-through nonwoven fabrics, spunbond nonwoven fabrics, SMS nonwoven fabrics, spunlace nonwoven fabrics, airlaid pulp nonwoven fabrics, etc.), tissues, woven fabrics, and knitted fabrics. Such fiber sheets may have a single-layer structure or a multilayer structure of two or more layers. The type of constituent fibers of the fiber sheet is not particularly limited, and examples include hydrophilic fibers such as cellulose fibers and thermoplastic resin fibers that have undergone hydrophilic treatment. These fibers may be used individually or in combination of two or more types of fibers.

[0067] In this embodiment, water-soluble functional powder P F The sheet 7 on which the functional powder P is fixed preferably includes the fiber sheet described above, and the inter-fiber distance of the constituent fibers of the fiber sheet is 100 μm or less. F If the sheet 7 to which the functional powder P is fixed includes a fiber sheet having such a specific inter-fiber distance, then the functional powder P F It becomes difficult for it to move through the constituent fibers of the fiber sheet. Specifically, functional powder P F If the particle size is 100 μm or larger, functional powder P F The relationship between the particle size and the inter-fiber distance of the constituent fibers of the fiber sheet determines the functional powder P F It is difficult for the functional powder P to move through the constituent fibers of the fiber sheet, andF Even if the particle size is less than 100 μm, functional powder P F The functional powder P is forced to move in a meandering manner, colliding with the constituent fibers of the fiber sheet, and as a result F The particles become less likely to move through the constituent fibers of the fiber sheet. Therefore, a sheet 7 containing a fiber sheet having such a specific inter-fiber distance allows for a predetermined amount or more of functional powder P to move through the spaces between the constituent fibers of the fiber sheet. F Because it is even more difficult to move from sheet 7, water-soluble functional powder P F This allows the function to be performed more reliably.

[0068] While there is no particular lower limit to the interfiber distance of the constituent fibers of the fiber sheet, it is preferable that the interfiber distance of the constituent fibers of the fiber sheet be 10 μm or more, from the viewpoint of liquid permeability and flexibility.

[0069] Here, the "inter-fiber distance of the constituent fibers of the fiber sheet" can be measured according to the following <Method for measuring inter-fiber distance>.

[0070] <Method for measuring inter-fiber distance> (1) Using a microscope manufactured by Keyence Corporation, a 3D composite image is created from the outermost surface of the fiber sheet to be measured (e.g., nonwoven fabric, etc.) to a depth of 40 μm. (2) Extract the fiber surface that is in focus in the 3D composite image and measure the diameter (μm) of the inscribed circle of the gap between the fibers. (3) Measure the diameter of the inscribed circle of the gap between fibers at 30 locations (n=30), calculate the average value, and define the interfiber distance (μm).

[0071] Furthermore, the external shape, various dimensions, and basis weight of the sheet material (e.g., fiber sheet) that can be used in the sheet on which the functional powder is fixed are not particularly limited as long as they do not hinder the effects of the present invention, and any shape, various dimensions, and basis weight can be adopted according to the desired liquid permeability, flexibility, etc. For example, when using the above-mentioned fiber sheet as the sheet material, the basis weight is 5 g / m². 2 ~80g / m 2The basis weight is within the range of 5 μm to 60 μm, the fiber diameter of the constituent fibers is within the range of 5 μm to 1500 μm, and the thickness is within the range of 50 μm to 1500 μm.

[0072] (Functional powder) In this embodiment, the functional powder is not particularly limited as long as it is a water-soluble powdered functional agent, and any powdered functional agent can be used depending on the desired additional function or effect. Examples of such functional agents include blood modifiers (e.g., osmotic pressure regulators), fragrances, warming agents, cooling agents, fever-inducing agents, antibacterial agents, pH adjusters, skincare agents, and deodorants. These functional agents may be used alone or in combination of two or more types.

[0073] In the sanitary napkin 1 of this embodiment, it is preferable to use a powdered blood modifier, particularly an osmotic pressure regulator, as the water-soluble functional powder, in order to improve absorption performance by making it less likely for menstrual blood or other excretory fluids to re-wet.

[0074] Osmotic regulators are substances that regulate the osmotic pressure of blood cell components (blood cells such as red blood cells, white blood cells, and platelets) in the blood. Examples include chemical substances called osmolytes, specifically neutral zwitterions (e.g., glycine, serine, betaine), sugars (e.g., glucose, fructose, galactose, mannose, xylose, erythrose, sucrose), polyhydric alcohols (e.g., sorbitol, mannitol, xylitol, erythritol, inositol), methylammonium compounds, sulfonium compounds, and cyclic carboxylic acid esters (e.g., glucuronolactone).

[0075] Furthermore, in this embodiment, the functional powder is preferably one that has a solubility of 8 g / 100 g H2O or higher in 100 g of ion-exchanged water at 25°C. Since such a functional powder has a solubility that does not completely dissolve in small amounts of excrement (for example, the amount of a single excretion), the function of the functional powder can be exerted for a longer period of time.

[0076] Examples of functional powders with such solubility include osmotic pressure regulators such as taurine, betaine, serine, glycine, glycylglycine, tricine, glucose, fructose, galactose, mannose, xylose, erythritol, sorbitol, mannitol, xylitol, and erythritol.

[0077] The solubility of the functional powder in 100g of ion-exchanged water at 25°C is more preferably 10g / 100g or more, and even more preferably 25g / 100g or more. Furthermore, the solubility of the functional powder in 100g of ion-exchanged water at 25°C is more preferably 72g / 100g or less, and even more preferably 36g / 100g or less.

[0078] When a sheet on which a water-soluble functional powder is fixed includes a fiber sheet in which the interfiber distance of the constituent fibers is 100 μm or less, as described above, it is preferable to use a functional powder with a median volume particle size (D50) of 50 μm or more. When the interfiber distance of the constituent fibers of the fiber sheet and the median volume particle size of the functional powder are both within such specific ranges, the relationship between the particle size of the functional powder and the interfiber distance of the constituent fibers of the fiber sheet makes it even more difficult for the functional powder to move through the constituent fibers of the fiber sheet, thereby allowing the function of the water-soluble functional powder to be exhibited more reliably.

[0079] The upper limit of the median particle size by volume of the functional powder is not particularly limited, but for example, a particle size of 1500 μm or less is possible.

[0080] <Method for measuring the median particle size of functional powders> Here, the median particle size (D50) of the functional powder can be measured as the median diameter of the functional powder in the crude dispersion using a laser diffraction / scattering particle size distribution analyzer (Horiba, Ltd., LA-960).

[0081] In this embodiment, the means and form of fixing the water-soluble functional powder to the sheet member are not particularly limited as described above, but the functional powder P F As shown in Figure 3, adhesive H M It is preferable that the functional powder P is fixed to the fiber sheet (sheet members 71 and 72 in Figure 3) by this. F Adhesive H M When fixed to a fiber sheet by, functional powder P F Furthermore, it becomes less likely for the fibers to detach from the fiber sheet, and at least a portion of the constituent fibers of the fiber sheet are bonded to the adhesive H M The constituent fibers are joined and fixed together by this, making it less likely for the inter-fiber distance between the constituent fibers of the fiber sheet to change, or the adhesive H M By positioning the material to block at least a portion of the gaps between the constituent fibers of the fiber sheet, the gaps between the constituent fibers of the fiber sheet are reduced, and the functional powder P F This makes it difficult for the functional powder P to move through the constituent fibers of the fiber sheet. F This allows the function to be performed more reliably.

[0082] Furthermore, there are no particular restrictions on the application method of the adhesive to the fiber sheet; any application method such as curtain coating or spiral coating can be used. Additionally, there are no particular restrictions on the amount of adhesive applied to the fiber sheet; any amount can be applied according to the desired liquid permeability, for example, 1 g / m². 2 ~20g / m 2 The amount of coating applied is one example.

[0083] Furthermore, as shown in Figure 3, the sheet 7 on which the functional powder is fixed includes two sheet members 71 and 72 that overlap in the thickness direction T of the sanitary napkin 1, and the functional powder P FIt is preferable that it is sandwiched between these two sheet members 71 and 72. Functional powder P F When the functional powder P is sandwiched between two sheet members 71 and 72, F Because it becomes even more difficult to move from sheet 7, functional powder P F This allows the function to be performed more reliably.

[0084] Furthermore, in this embodiment, the functional powder P F As shown in Figure 4(a), the sheet 7 to which the functional powder P is fixed has a joint 73 formed by joining two sheet members 71 and 72, and a non-jointed portion 74 which is demarcated as the portion surrounded by the joint 73 in a plan view, and the functional powder P F The non-joint portion 74 is positioned in this manner. F If the functional powder P is positioned between the two sheet members 71 and 72 within a closed space called a non-jointed portion 74 surrounded by a joint portion 73, then the functional powder P F Because it becomes difficult for it to move from sheet 7, water-soluble functional powder P F This allows the system to perform its functions more effectively.

[0085] Note that functional powder P F The arrangement of the joint portion 73 and non-joint portion 74 in the sheet 7 to which the functional powder P is fixed is not limited to that of this embodiment (i.e., the arrangement shown in Figure 4(a)). Here, Figure 4 shows the water-soluble functional powder P F This is a schematic plan view illustrating variations in the arrangement of the joint portion 73 and non-joint portion 74 of the fixed sheet 7.

[0086] Specifically, in the arrangement shown in Figure 4(a), a roughly rectangular non-joint portion 74, which is long in the longitudinal direction of the sheet 7, is arranged to extend longitudinally at the center of the sheet 7 in the width direction. On the other hand, the joint portion 73 is arranged to surround the non-joint portion 74.

[0087] Furthermore, in the arrangement shown in Figure 4(b), four roughly rectangular non-joint portions 74, which are elongated in the width direction of the sheet 7, are arranged in the center of the sheet 7 in the width direction at predetermined intervals along its longitudinal direction. On the other hand, the joint portion 73 is arranged to surround all four non-joint portions 74, and is also arranged to extend in the width direction of the sheet 7 between adjacent non-joint portions 74 in the longitudinal direction of the sheet 7.

[0088] Furthermore, in the arrangement shown in Figure 4(c), eight roughly rectangular non-joint portions 74 are arranged in the center of the sheet 7 in the width direction, with predetermined intervals in the longitudinal and width directions (four non-joint portions 74 arranged in the longitudinal direction form one row, and two rows are arranged in the width direction with predetermined intervals). On the other hand, the joint portions 73 are arranged to surround all eight non-joint portions 74, and are also arranged to extend in the width direction of the sheet 7 between adjacent non-joint portions 74 in the longitudinal direction of the sheet 7, and between adjacent non-joint portions 74 in the width direction of the sheet 7, are also arranged to extend in the longitudinal direction of the sheet 7.

[0089] The arrangement shown in Figure 4(d) is such that twelve roughly rectangular non-joint portions 74, elongated in the longitudinal direction of the sheet 7, are arranged at predetermined intervals in both the longitudinal and width directions at the center of the sheet 7 in the width direction (four non-joint portions 74 arranged in the longitudinal direction form one row, and three rows are arranged at predetermined intervals in the width direction). On the other hand, the joint portions 73 are arranged to surround all twelve non-joint portions 74, and are also arranged to extend in the width direction of the sheet 7 between adjacent non-joint portions 74 in the longitudinal direction of the sheet 7, and between adjacent non-joint portions 74 in the width direction of the sheet 7, are also arranged to extend in the longitudinal direction of the sheet 7.

[0090] The arrangements shown in Figures 4(a) to 4(d) assume that the sheet 7 is placed inside the sanitary napkin 1 so that the longitudinal direction of the sheet 7 corresponds to the longitudinal direction L of the sanitary napkin 1.

[0091] Functional powder P FThe sheet 7 to which the functional powder P is fixed has multiple non-jointed portions 74, as shown in the arrangement configuration in Figures 4(b) to (d), and the functional powder P F It is preferable that the water-soluble functional powder P is dispersed in each of the multiple non-jointed portions 74. F When these are dispersed in each of the multiple non-jointed portions 74, the functional powder P F Because it can be positioned more precisely and less likely to move, functional powder P F This allows the system to perform its functions even more effectively.

[0092] Furthermore, functional powder P F It is particularly preferable that the sheet 7 to which the functional powder P is fixed has a plurality of non-joint portions 74 arranged in the longitudinal direction L of the sanitary napkin 1, and that the joint portions 73 between adjacent non-joint portions 74 extend in the width direction W of the sanitary napkin 1. F If the multiple non-joint portions 74 on which the functional powder P is located are arranged so as to be aligned in the longitudinal direction L of the sanitary napkin 1, and the joint portions 73 between adjacent non-joint portions 74 are arranged so as to extend in the width direction W of the sanitary napkin 1, then the functional powder P F In addition, the functional powder P can be positioned precisely and is difficult to move, and the joint portion 73 extending in the width direction W of the sanitary napkin 1 functions as a deformation-inducing portion (i.e., it functions as a base point for bending in the longitudinal direction L), making it easier for the sanitary napkin 1 to deform to conform to the shape of the wearer's body. As a result, the functional powder P F This allows the system to perform its functions more accurately.

[0093] In particular, the joint portions 73 extending in the width direction W of the sanitary napkin 1 are preferably arranged in a plurality at predetermined intervals in the longitudinal direction L of the sanitary napkin 1, as shown in the arrangement configurations in Figures 4(b) to (d), and it is even more preferable that the joint portions 73 extend in the longitudinal direction L of the sanitary napkin 1, as shown in the arrangement configurations in Figures 4(c) and (d). When the joint portions 73, which can function as deformation-inducing portions, are arranged in this manner, the sanitary napkin 1 becomes more likely to deform to conform more accurately to the shape of the wearer's body, and in particular, the sanitary napkin 1 can be fitted accurately to the wearer's body even while the wearer is moving, thus allowing the functional powder P F This allows the product to perform its functions more accurately, while also improving comfort and leak resistance.

[0094] The absorbent articles of the present invention are not limited to the sanitary napkins of the embodiments described above, but can be applied to various absorbent articles such as panty liners, absorbent pads, and disposable diapers.

[0095] Furthermore, the present invention is not limited to the embodiments described above or the following examples, and can be appropriately combined, substituted, or modified without departing from the purpose and spirit of the present invention. [Examples]

[0096] The present invention will be described in more detail below with reference to examples and comparative examples, but the present invention is not limited to these examples.

[0097] Example 1 A sheet material was prepared by cutting the air-through nonwoven fabric-1 (hereinafter referred to as "AT-1") shown in Table 1 below into a 50mm x 50mm square. Next, 0.20g of large-particle glycine (Gly-large particle size; G-1) shown in Table 2 was weighed out as a water-soluble functional powder and uniformly coated onto the sheet material (101.9g / m²) using an acrylic ring with an inner diameter of 25mm. 2 By applying a considerable amount of coating, a sheet of Example 1 with functional powder fixed in place was manufactured.

[0098] Example 2 Before applying the functional powder to the sheet material, apply a hot-melt adhesive to the sheet material at a rate of 5 g / m². 2 The sheet of Example 2 was manufactured in the same manner as in Example 1, except that spiral spray coating was performed with the specified coating amount.

[0099] Example 3 Before applying the functional powder to the sheet material, apply a hot-melt adhesive to the sheet material at a rate of 5 g / m². 2 The sheet of Example 3 was manufactured in the same manner as in Example 1, except that it was coated using a curtain spray coating with the specified coating amount.

[0100] Example 4 The sheet of Example 4 was manufactured in the same manner as in Example 1, except that two sheet members were made, and after coating the functional powder onto the sheet members, another sheet member (i.e., AT-1 shown in Table 1 below, cut into a 50mm x 50mm square) was placed on top of the functional powder, sandwiching the functional powder between the two sheet members.

[0101] Examples 5-97 and Comparative Examples 1-15 Except for changing the type of sheet material and the type of functional powder as shown in Tables 1 to 5 below, the sheets of Examples 5 to 97 and Comparative Examples 1 to 15 were manufactured in the same manner as in Examples 1 to 4 described above.

[0102] For each sheet manufactured as described above in Examples 1 to 97 and Comparative Examples 1 to 15, a permeation-to-shedding test was performed according to (5) to (9) of the <Permeation-to-Shedding Test> described above, and the remaining percentage of the functional powder in each sheet was measured. For the measurement of the remaining percentage, an initial content (g) of the functional powder of 0.20 g was used.

[0103] The results of the remaining percentage of functional powder in each sheet of Examples 1-97 and Comparative Examples 1-15 are shown in Tables 3-5 below. In Tables 3-5 below, "N" in the adhesive coating form means that no adhesive was applied to the sheet material, and "SP" means that a hot-melt type adhesive was applied to the sheet material at a rate of 5 g / m². 2 "CT" means that the sheet material was coated with spiral spray paint using a coating amount of 5g / m². 2 This means that the curtain spray coating was applied using that amount of paint.

[0104] [Table 1]

[0105] [Table 2]

[0106] [Table 3]

[0107] [Table 4]

[0108] [Table 5]

[0109] As shown in Tables 3 to 5, in each embodiment of the present invention, by selecting the type of sheet member, the interfiber distance, the particle size of the functional powder, etc., or by applying an adhesive to the sheet member or sandwiching the functional powder between two sheet members, it was possible to obtain a sheet with a functional powder retention rate of 50% or more. Furthermore, it was found that when the particle size of the functional powder is large, the retention rate of the functional powder in the sheet tends to be low, but this can be improved by applying an adhesive to the sheet member or sandwiching the functional powder between two sheet members. In addition, it was found that when the interfiber distance of the sheet member is large, the retention rate of the functional powder in the sheet also tends to be low, but this can be improved by selecting a functional powder with a larger particle size.

[0110] Based on the above, it is considered that the sheets of each embodiment of the present invention can fully exhibit the functions of water-soluble functional powders because the amount of functional powder fixed to the sheet is above a certain level and the functional powder is less likely to move away from the sheet. [Explanation of Symbols]

[0111] 1. Sanitary napkin 2. Surface sheet 3. Back sheet 4 Absorbent 41. Absorbent core on the skin-facing side 42 Non-skin opposing side absorption core 43 Core Wrap Sheet 5 side seats 6. Intermediate Sheet 7. Sheet on which water-soluble functional powder is immobilized. 71 Sheet material 72 Sheet material 73 Joint 74 Non-joint part H M glue P F Water-soluble functional powders

Claims

1. An absorbent article comprising a sheet on which a water-soluble functional powder is immobilized, The aforementioned functional powder is an osmotic pressure adjusting agent. The amount of the functional powder fixed to the sheet is 50 g / m². ２ That's all. The residual rate of the functional powder in the permeation detachment test is 50% or more. The sheet on which the functional powder is fixed includes a fiber sheet, wherein the inter-fiber distance of the constituent fibers of the fiber sheet is 10 μm or more and 100 μm or less. The absorbent article is characterized in that the volume median particle size (D50) of the functional powder is 50 μm or more and 1500 μm or less.

2. The absorbent article comprises a liquid-permeable surface sheet, a liquid-impermeable back sheet, an absorbent positioned between these two sheets, and an intermediate sheet positioned between the surface sheet and the absorbent. The absorbent body comprises a skin-facing side absorbent core located relatively on the skin-facing side in the thickness direction of the absorbent article, a non-skin-facing side absorbent core located relatively on the non-skin-facing side in the thickness direction, and a core wrap sheet enclosing the skin-facing side absorbent core and the non-skin-facing side absorbent core. The absorbent article according to claim 1, characterized in that the sheet on which the functional powder is fixed is positioned in the thickness direction at least one of the following positions: a position on the skin-facing side of the surface sheet, a position between the surface sheet and the intermediate sheet, a position between the intermediate sheet and the core wrap sheet, a position between the core wrap sheet and the skin-facing side absorbent core, and a position between the skin-facing side absorbent core and the non-skin-facing side absorbent core.

3. The absorbent article according to claim 1 or 2, characterized in that the functional powder is fixed to the fiber sheet by an adhesive.

4. The sheet on which the functional powder is fixed includes two sheet members that overlap in the thickness direction of the absorbent article. The absorbent article according to any one of claims 1 to 3, characterized in that the functional powder is sandwiched between the two sheet members.

5. The sheet on which the functional powder is fixed has a joint portion formed by joining the two sheet members, and an unjointed portion that is demarcated as a portion surrounded by the joint portion in a plan view. The absorbent article according to claim 4, characterized in that the functional powder is arranged in the non-jointed portion.

6. The sheet on which the functional powder is fixed has a plurality of non-jointed portions. The absorbent article according to claim 5, characterized in that the functional powder is dispersed in each of the plurality of non-jointed portions.

7. The absorbent article has a longitudinal direction and a width direction when viewed from above. The absorbent article according to claim 6, characterized in that the sheet on which the functional powder is fixed has a plurality of non-joint portions arranged in the longitudinal direction, and the joint portions between adjacent non-joint portions are arranged to extend in the width direction.

8. The functional powder has a solubility of 8 g / 100 gH in 100 g of ion-exchanged water at 25°C. ２ An absorbent article according to any one of claims 1 to 7, characterized in that it is 0 or greater.

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