JP7610334B2 - Absorbent articles - Google Patents

Description

The present invention relates to an absorbent article.

Due to the recent labor shortage in nursing care sites, there is a demand for large-capacity absorbent articles that can highly absorb body fluids in order to reduce the number of times disposable diapers need to be changed. To achieve high absorption and large capacity in absorbent articles, conventionally, absorbents that contain a large amount of absorbent fibers such as fluff pulp and superabsorbent polymers have been used. However, such absorbent articles have a characteristic of the superabsorbent polymer, which is responsible for much of the absorption capacity, that is, after absorbing body fluids, it swells relatively significantly in the thickness direction. Therefore, it is inevitable that the wearer feels a sense of pressure when wearing the article for a long time and excreting body fluids multiple times, which leads to a worsening fit and stuffiness, and can also cause skin problems.

In order to make absorbents thinner, various thin absorbent sheets (hereafter also referred to as "SAP sheets") have been developed and proposed, in which a superabsorbent polymer (hereafter also referred to as "SAP") is fixed between two hydrophilic nonwoven fabrics using a hot melt adhesive, and which do not contain absorbent fibers such as fluff pulp.

Patent Document 1 proposes an absorbent article in which the absorbent is configured as a laminate of a skin-side absorbent located on the skin side of the wearer and a non-skin-side absorbent located on the non-skin side of the wearer, the skin-side absorbent is an absorbent sheet (hereinafter simply referred to as "absorbent sheet") in which an absorbent polymer is fixedly supported between two hydrophilic nonwoven fabrics, and the non-skin-side absorbent is a fluff absorbent (hereinafter simply referred to as "fluff absorbent") containing absorbent fibers and a highly absorbent polymer (claims 1 and 4). Patent Document 1 describes that the amount of bodily fluid absorption is increased while preventing a decrease in the strength of the absorbent and an increase in the thickness of the absorbent. It is also said that the use of the absorbent in Patent Document 1 can reduce backflow.

Patent Document 2 discloses an absorbent article in which a front absorbent body, an intermediate absorbent body, and a rear absorbent body are arranged in series in the longitudinal direction in this order, the intermediate absorbent body is a fluff absorbent body, the front absorbent body and the rear absorbent body are absorbent sheets, the rear end of the front absorbent body is adjacent to or overlaps with the front end of the intermediate absorbent body, and the rear end of the intermediate absorbent body is adjacent to or overlaps with the front end of the rear absorbent body. Patent Document 2 describes that the absorbent article is kept thin while preventing leakage of bodily fluids.

JP 2018-164633 A JP 2020-049178 A

In the absorbent article described in Patent Document 1, bodily fluids in the absorbent sheet (upper absorbent element) 40 are easily diffused to the surroundings, and bodily fluids are supplied to the fluff absorbent (lower absorbent element) 50 over a wider area (paragraph 0008). On the other hand, the fluff absorbent 50 is formed larger in both the length and width directions than the absorbent sheet 40 (see FIG. 1, etc.), and the absorbent sheet 40 and the fluff absorbent 50 have different degrees of swelling when absorbing bodily fluids. For this reason, a step may be generated between the periphery of the absorbent sheet 40 and the surface (skin side) of the fluff absorbent 50, or the buttocks may be compressed due to swelling after absorbing bodily fluids, resulting in a noticeable decrease in wearing comfort. In addition, when worn for a long time, the above-mentioned step is likely to cause skin problems such as rashes on the wearer's skin. Furthermore, because the absorbent sheet is in direct contact with the wearer's skin, the wearer is more likely to feel the roughness of the superabsorbent polymer before absorbing bodily fluids, and the pressure of the jelly-like superabsorbent polymer that has swelled after absorbing bodily fluids, which also reduces the comfort of wearing the absorbent article.

The absorbent article described in Patent Document 2 increases the amount of body fluid absorbed by combining a fluff absorbent body with an absorbent sheet, but because there are areas where the absorbent sheet contacts the wearer's skin, the roughness and pressure sensation of the absorbent polymer described above is easily felt, and the wearing comfort is not fully satisfactory. In addition, because the fluff absorbent body and the absorbent sheet have different absorption speeds and amounts of body fluid, when a large amount of body fluid is discharged at one time, there is a tendency for steps to occur and for body fluid to leak sideways at the boundary area between the fluff absorbent body and the absorbent sheet.

Patent Document 1 and Patent Document 2 do not describe a structure or method for preventing the occurrence of unevenness due to differences in swelling between the fluff absorbent and the absorbent sheet when using the fluff absorbent in combination with an absorbent sheet, maintaining good fit, and preventing skin troubles for the wearer even when body fluids are repeatedly absorbed.

The objective of the present invention is to provide an absorbent article that suppresses the occurrence of unevenness even after multiple body fluid absorptions over long periods of use, maintains a good fit, and has excellent body fluid diffusion properties.

As a result of intensive research by the inventors to solve the above problems, they discovered that a desired absorbent article can be obtained by providing a through-hole region in the thickness direction at the center of the surface direction of the skin-side absorbent body and fitting the aforementioned absorbent sheet into the through-hole region in an absorbent article including an absorbent body using a combination of a fluff absorbent body and an absorbent sheet, the fluff absorbent body including a skin-side absorbent body arranged on the skin side and a non-skin-side absorbent body arranged on the non-skin side, using a specific absorbent sheet having a superabsorbent polymer fixedly supported between the raised fibers, and thus completing the present invention. In other words, the present invention relates to the following absorbent article.

(1) An absorbent article used as an inner pad, comprising a liquid-permeable top sheet, a liquid-impermeable back sheet, and an absorbent disposed therebetween,
The length direction dimension is 600 mm or more and 800 mm or less, and the maximum width direction dimension is 300 mm or more and 400 mm or less,
the absorbent body includes a skin-side absorbent body arranged on the skin side and a non-skin-side absorbent body arranged on the non-skin side, the skin-side absorbent body and the non-skin-side absorbent body each containing absorbent fibers and a first highly absorbent polymer;
the skin-side absorbent body has an absorbent sheet embedded in a substantially widthwise center portion of a skin-side surface layer of the skin-side absorbent body, the absorbent sheet being a bulky hydrophilic sheet having one side raised to support a second superabsorbent polymer, the absorbent sheet having a length dimension of 160 mm or more and 740 mm or less and a width dimension of 60 mm or more and 150 mm or less;
the skin-side absorbent body has a minimum widthwise dimension equal to or larger than the widthwise dimension of the non-skin-side absorbent body, a maximum widthwise dimension of 230 mm or more and 360 mm or less, a minimum widthwise dimension of 120 mm or more and 250 mm or less, and a lengthwise dimension of 470 mm or more and 740 mm or less, the absorbent fiber has a basis weight of 180 g/ ^m2 or more and 390 g/m2 ^or less, and the first superabsorbent polymer has a basis weight of 70 g/m2 or ^more and 270 g/m2 ^or less,
the hydrophilic sheet is composed of a hydrophilic air-through nonwoven fabric having a water permeability of 10 points or more the first time and 9 points or more the second time, as measured by the hydrophilicity measurement method described below; the hydrophilic air-through nonwoven fabric has a basis weight of 55 g/m2 or ^more and 110 g/m2 ^or less, the basis weight of the second superabsorbent polymer on the raised one side surface is 70 g/ ^m2 or more and 320 g/m2 ^or less, and the apparent specific volume of the raised one side surface in an unloaded state is 35 ^cm3 /g or more and 120 ^cm3 /g or less;
When the absorbent article is placed on a flat, smooth surface, the difference in level between the skin side of the skin-side absorbent body arranged on the skin side and the skin side of the absorbent sheet is 0.5 mm or less under a load of 35 g/ ^cm2 ;
An absorbent article, wherein a diffusion sheet made of a hydrophilic sheet is disposed between the top sheet and the skin-side absorbent body, covering the skin-side surface of the absorbent sheet, and the diffusion sheet has a basis weight of 30 g/m2 or ^more and 70 g/m2 ^{or less} .
(Method of measuring hydrophilicity)
Place the sample on 2 sheets of absorbent paper x 5 sets = 10 sheets, and place the 10-point measurement plate on top. Drop one drop (0.05 mL) of 0.9% saline solution at 37°C onto each of the 10 points, and count the number of points absorbed within 2 seconds as the number of times water permeates. Drop the solution onto the same points repeatedly every 3 minutes.
(2) The absorbent article according to (1) above, wherein the absorbent sheet has an area in which the second superabsorbent polymer has a basis weight of 30 g/m2 or ^less within a range of 10% or more and 20% or less of its longitudinal dimension.
(3) An absorbent article of (1) or (2) above, wherein the vortex speed of the first superabsorbent polymer used in the skin-side absorbent body is 30 seconds or more and 70 seconds or less, and the vortex speed of the second superabsorbent polymer used in the absorbent sheet is 1 second or more and 30 seconds or less.

The present invention provides an absorbent article that suppresses the occurrence of unevenness even after multiple body fluid absorptions over long periods of use, maintains a good fit, and has excellent body fluid diffusion properties.

1 is a plan view showing a schematic configuration of an absorbent article according to an embodiment of the present invention. 2 is a schematic cross-sectional view in the width direction taken along the X ₁ -X ₁ cutting line shown in FIG. 1 . FIG. 2 is an exploded perspective view showing a schematic configuration of an absorbent body. FIG. 2 is a schematic cross-sectional view in the thickness direction showing the configuration of the skin-side absorbent body. FIG. 1 is a schematic plan view showing the arrangement of absorbent sheets in a skin-side absorbent body; FIG. 11 is a schematic plan view showing the configuration of an absorbent sheet in another embodiment. FIG. 2 is a schematic diagram showing the absorbent article according to the present embodiment worn on the side in a supine position. 1 is a schematic diagram showing an absorbent article according to an embodiment of the present invention worn in a supine position on the front. FIG. FIG. 2 is a schematic diagram showing a method for measuring hydrophilicity.

In this specification, wearing an absorbent article refers to the state in which the absorbent article is worn on the body, regardless of whether bodily fluids have been absorbed or not. In an absorbent article, the length direction (or longitudinal direction) is the direction shown by Y in the figure that runs from the front to the back of the body through the wearer's crotch when the absorbent article is worn on the body, the width direction is the direction shown by X in the figure that is perpendicular to the length direction, and the thickness direction is the direction shown by Z in the figure in which the components are stacked. The skin side is the surface that contacts the wearer's skin or faces the skin when the absorbent article is worn, and the non-skin side is the surface that contacts the wearer's clothing or faces the clothing. Body fluids refer to liquids discharged from the body to the outside, such as urine, blood, and water in loose stools.

<Absorbent Articles>
Hereinafter, an absorbent article 50 according to this embodiment will be described with reference to the drawings. Figures 1 and 2 show the absorbent article 50. Figures 3 to 6 show the absorbent body 20. These drawings do not stipulate the shape, dimensions, size relationship, etc. of each component member in the absorbent article 50.

The absorbent article 50 of this embodiment can be suitably used as an inner pad to be used in combination with a paper diaper product (outerwear) such as pants-type paper diapers and tape-fastened paper diapers for infants and adults. The form of the inner pad is not particularly limited as long as it can be attached inside the paper diaper product, and examples include light incontinence pads and urine absorption pads. The absorbent article 50 is not limited to use as an inner pad, and may be used alone as a pad product. The length direction dimension (hereinafter also simply referred to as "length") of the absorbent article 50 is in the range of 600 mm to 800 mm, and the width direction dimension (maximum dimension in the width direction, hereinafter also simply referred to as "width") is in the range of 300 mm to 400 mm. By selecting the length and width from each of the above-mentioned ranges, it is possible to easily obtain the absorbent article 50 as an inner pad that can be attached inside the outerwear with good fit and wearing comfort (wearing comfort).

As shown in Figures 1 and 2, the absorbent article 50 of this embodiment comprises a liquid-permeable top sheet 10 located on the skin side, a liquid-impermeable back sheet 30 located opposite the top sheet 10 and on the non-skin side, an absorbent body 20 arranged between the top sheet 10 and the back sheet 30, and a pair of three-dimensional gathers 40 provided on the skin side of the top sheet 10. As shown in Figures 2 to 4, the absorbent body 20 comprises a skin-side absorbent body 21 located on the skin side and containing absorbent fibers and a first superabsorbent polymer, and a non-skin-side absorbent body 22 located on the non-skin side and containing absorbent fibers and a first superabsorbent polymer, and has a structure in which an absorbent sheet 23 that does not contain absorbent fibers such as fluff pulp is embedded in the approximate widthwise center of the skin side of the skin-side absorbent body 21, and a diffusive sheet 15 made of a hydrophilic sheet is arranged between the top sheet 10 and the absorbent body 20 so as to cover the skin side of the absorbent sheet 23. The absorbent sheet 23 is a bodily fluid absorbent member having a bodily fluid absorbent layer in which a second superabsorbent polymer 12 is fixed and supported between multiple raised fibers 11x that are raised on one side 11a of the base nonwoven fabric 11, which is a bulky hydrophilic sheet.

According to this embodiment, in a fluff absorbent body in which the skin-side absorbent body 21 and the non-skin-side absorbent body 22 are layered in the thickness direction, an absorbent sheet 23 having excellent body fluid absorbency, cushioning properties in the thickness direction due to the multiple raised fibers 11x, flexibility, and excellent body fluid diffusion due to the gaps between the raised fibers 11x is fitted into the widthwise center of the skin-side absorbent body 21 that mainly abuts the wearer's crotch area, and the basis weights of the first superabsorbent polymer and absorbent fibers contained in the skin-side absorbent body 21, the basis weight and specific volume of the base nonwoven fabric 11, the basis weight of the second superabsorbent polymer fixedly supported on the raised surface 11a of the base nonwoven fabric 11, the basis weight of the diffusion sheet 15, etc. are set within predetermined ranges. As a result, firstly, the bodily fluid diffusion and absorption speed throughout the absorbent body 20 are maintained well even after multiple body fluid absorptions due to long-term wear, and even when the absorbent article 50 is under a constant load and absorbs bodily fluids, the cushioning properties of the absorbent sheet 23 reduce the difference in swelling rate after body fluid absorption between the skin-side absorbent body 21 and the absorbent sheet 23, keeping the skin-side side of the skin-side absorbent body 21 and the skin-side side of the absorbent sheet 23 almost flush, suppressing the occurrence of large unevenness that could cause a decrease in fit or skin troubles for the wearer, and making it possible to provide an absorbent article 50 that is very comfortable to wear and can withstand multiple excretions of bodily fluids over a long period of time. As shown in Figures 7 and 8, when the absorbent article 50 is worn, the absorbent sheet 23 is placed in an area where body pressure is likely to be applied in the supine position, where bodily fluids tend to stagnate and accumulate, but due to the action of the absorbent sheet 23 described above, the diffusion and absorption of bodily fluids proceeds quickly even under body pressure, and the comfort of wearing the absorbent article is not impaired. In Figures 7 and 8, the position of the absorbent sheet 23 when the absorbent article 50 is worn is shown by a solid line in order to clearly show the position.

Secondly, by arranging the non-raised surface 11b of the base nonwoven fabric 11 as the skin-side surface of the absorbent sheet 23, the occurrence of a step between the skin-side surface of the skin-side absorbent body 21 and the skin-side surface of the absorbent sheet 23 is further suppressed, thereby maintaining a better wearing comfort.
Thirdly, the napped surface 11a of the absorbent sheet 23, on which the plurality of napped fibers 11x are arranged, has the function of retaining body fluids immediately after they are discharged, thereby preventing wet-back.

Fourthly, by configuring the absorbent sheet 23 to have an area in which the second superabsorbent polymer 12 has a basis weight of 30 g/ ^m2 or less within a range of 10% or more and 20% or less of the longitudinal dimension, and/or by configuring the vortex speed of the first superabsorbent polymer (not shown) used in the skin-side absorbent body 21 to be 30 seconds or more and 70 seconds or less, and the vortex speed of the second superabsorbent polymer 12 used in the absorbent sheet 23 to be 1 second or more and 30 seconds or less, the flexibility and mobility of the absorbent article 50 are less likely to decrease even after it has absorbed bodily fluids, and good wearability is maintained from the start to the end of use of the absorbent article 50.

The absorbent article 50 of this embodiment has the top sheet 10, the diffusion sheet 15, the absorbent body 20, and the back sheet 30 as basic constituent units, and can be modified as necessary with various known modifications, such as the provision of the three-dimensional gathers 40 as described above, and the provision of a liquid-permeable second sheet other than the diffusion sheet 15 between the top sheet 10 and the absorbent body 20. The components of the absorbent article 50 are described in more detail below in the order of the top sheet 10, the liquid-diffusion sheet 15, the absorbent body 20, the back sheet 30, and the three-dimensional gathers 40.

<Top sheet>
The top sheet 10 is a liquid-permeable sheet-like substrate that allows bodily fluids to pass quickly toward the absorbent 20. The top sheet 10 is preferably a substrate that has a soft feel and does not irritate the skin so that it may come into contact with the wearer's skin. Examples of the substrate include hydrophilic sheets, composite nonwoven fabrics that are laminates of the same or different hydrophilic sheets, open-ended films such as open-ended polyethylene films, and foamed films such as polyethylene foam and urethane foam. Examples of hydrophilic sheets include air-through nonwoven fabrics, thermal bond nonwoven fabrics, spunlace nonwoven fabrics, spunbond nonwoven fabrics, and the like, which are made using synthetic fibers made of synthetic resins such as polypropylene and polyethylene, regenerated fibers such as rayon, and natural fibers such as cotton. Among these, nonwoven fabrics are preferred, and air-through nonwoven fabrics, thermal bond nonwoven fabrics, spunbond nonwoven fabrics, and the like are more preferred.

The top sheet 10 may be embossed or perforated on the surface in order to improve liquid permeability. The top sheet 10 may contain one or more of lotion, antioxidant, anti-inflammatory component, pH adjuster, antibacterial agent, moisturizer, etc. in order to reduce irritation to the skin. The basis weight of the top sheet 10 is, for example, in the range of 18 g/m ² to 400 g/m ² in terms of strength, processability, and liquid return amount. The planar shape of the top sheet 10 (hereinafter also simply referred to as "planar shape") is not particularly limited, and may be a shape that covers a part or all of the absorbent body 20, which is necessary to guide bodily fluids to the absorbent body 20 without leakage.

<Diffusion sheet>
The diffusive sheet 15 is made of a hydrophilic sheet and is provided between the top sheet 10 and the absorbent body 20 so as to mainly cover the skin side of the absorbent sheet 23, and has the function of, for example, evenly supplying bodily fluid that has passed through the top sheet 10 to the skin-side absorbent body 21 and the absorbent sheet 23. As the liquid diffusive sheet 15, any hydrophilic sheet can be used without particular limitation, and examples thereof include hydrophilic nonwoven fabrics such as air-through nonwoven fabric, point-bonded nonwoven fabric, spun-bonded nonwoven fabric, melt-blown nonwoven fabric, and composite hydrophilic nonwoven fabrics such as spun-bonded nonwoven fabric/melt-blown nonwoven fabric laminates, and spun-bonded nonwoven fabric/melt-blown nonwoven fabric/spun-bonded nonwoven fabric laminates.

The basis weight of the diffusion sheet 15 is in the range of 30 g/m ² or more and 70 g/m ² or less. By selecting the basis weight of the diffusion sheet 15 from the above range, bodily fluids are uniformly distributed over the entire skin side of the absorbent sheet 23, and the entire absorbent sheet 23 can be used for absorbing bodily fluids. If the basis weight is less than 30 g/m ² , bodily fluids tend to be supplied locally to the absorbent sheet 23, and the entire absorbent sheet 23 tends not to be uniformly used. If the basis weight is more than 70 g/m ² , the bodily fluid permeability of the diffusion sheet 15 tends to be insufficient, and wetback tends to occur easily. In addition, the overlapping feel of the diffusion sheet 15 and the absorbent sheet 23 tends to be hard, and the wearing comfort tends to be reduced. The planar shape of the diffusion sheet 15 may be, for example, a shape that covers a part or all of the skin side of the absorbent sheet 23.

<Absorbent>
The absorbent body 20 is disposed between the diffusive sheet 15 and the back sheet 30 in the thickness direction, and absorbs and retains, for example, bodily fluids that have permeated through the top sheet 10 and the diffusive sheet 15. As shown in Figures 2 to 4, the absorbent body 20 comprises a skin-side absorbent body 21 disposed on the skin side, a non-skin-side absorbent body 22 disposed on the non-skin side, and an absorbent sheet 23 fitted into approximately the center in the width direction of the skin-side absorbent body 21.

<Skin side absorbent>
The skin-side absorbent body 21 is a fluff absorbent body containing absorbent fibers and a first superabsorbent polymer (not shown, the same applies below), and in this embodiment has an hourglass-shaped planar shape, with the dimension (minimum dimension) of the widthwise minimum part that mainly abuts against the wearer's crotch being equal to or larger than the widthwise dimension of the non-skin-side absorbent body 22, the widthwise dimension of the maximum part (both ends in the lengthwise direction) being in the range of 230 mm to 360 mm, the widthwise dimension of the minimum part (near the center in the lengthwise direction, the part that mainly abuts against the wearer's crotch) being in the range of 120 mm to 250 mm, and the lengthwise dimension being in the range of 470 mm to 740 mm. By having these dimensions, the rigidity of the absorbent body 20 as a whole and the absorption performance (absorption amount, absorption speed) of the absorbent article 50 as a whole can be maintained at a high level, while the absorbent sheet 23 inside it can be stably held and the absorbent sheet 23 can be prevented from falling off from the skin-side absorbent body 21.

The basis weight of the absorbent fiber in the skin-side absorbent body 21 is in the range of 180 g/ ^m2 or more and 390 g/m2 or ^less , and the basis weight of the first superabsorbent polymer is in the range of 70 g/ ^m2 or more and 270 g/ ^m2 or less. By setting the basis weights of the absorbent fiber and the first superabsorbent polymer within the above-mentioned ranges, it is possible to achieve a high level of absorption performance, rigidity, and wearing comfort of the skin-side absorbent body 21, and further to ensure that the absorbent sheet 23 is held by the skin-side absorbent body 21. The absorbent fiber and the first superabsorbent polymer will be described later.

The skin-side absorbent body 21 has a recess 24 (a through-hole that penetrates in the thickness direction in this embodiment) that is recessed toward the non-skin side in the region that mainly contacts the wearer's crotch near the center of the width of the skin-side absorbent body 21, and the absorbent sheet 23 is fitted into this recess 24. The recess 24 is formed, for example, from the center of the width of the skin-side absorbent body 21 to a position that is approximately equidistant to the left and right. The length and width dimensions of the recess 24 are formed to be the same as or slightly larger than the length and width dimensions of the absorbent sheet 23. Since the absorbent sheet 23 has appropriate cushioning properties, the skin-side absorbent body 21 and the skin-side absorbent sheet 23 are approximately flush with each other under body pressure when the absorbent article 50 is worn, and even after absorbing bodily fluids, there is no significant change to the above-mentioned flush state, and the occurrence of steps that may adversely affect the wearer's skin balance is suppressed.

<Non-skin side absorbent body>
The non-skin-side absorbent body 22 is a fluff absorbent body that contains absorbent fibers and a first superabsorbent polymer and is disposed on the non-skin side of the skin-side absorbent body 21. In this embodiment, the planar shape of the non-skin-side absorbent body 22 is substantially rectangular, but is not limited thereto, and examples thereof include an hourglass shape, an I-shape, an oval shape, an ellipse shape, and a rounded rectangle with rounded corners. In a preferred embodiment, the length and width dimensions of the non-skin-side absorbent body 22 are formed slightly larger than the length and width dimensions of the absorbent sheet 23, respectively. According to this embodiment, for example, when the recess 24 of the skin-side absorbent body 21 is the through-hole of this embodiment, it is possible to prevent the absorbent sheet 23 from falling off from the skin-side absorbent body 21, particularly after absorbing body fluids multiple times.

In the non-skin side absorbent body 22, the basis weight of the absorbent fiber is, for example, in the range of 100 g/ ^m2 to 800 g/ ^m2 or in the range of 180 g/ ^m2 to 450 g/ ^m2 . This allows more body fluid to be absorbed without impairing the feel against the skin. The basis weight of the first superabsorbent polymer in the non-skin side absorbent body 22 is, for example, in the range of 50 g/ ^m2 to 800 g/ ^m2 or in the range of 90 g/ ^m2 to 400 g/ ^m2 . By selecting the basis weight of the first superabsorbent polymer from the above-mentioned range, gel blocking in the non-skin side absorbent body 22 can be prevented, and the non-skin side absorbent body 22 can absorb body fluid multiple times. Furthermore, in the non-skin side absorbent body 22, the ratio of the weight of the first superabsorbent polymer to the total weight of the non-skin side absorbent body 22, (weight of first superabsorbent polymer/total weight of non-skin side absorbent body 22) x 100 (%), is, for example, in the range of 15 weight % or more, or in the range of 15 weight % or more and 70 weight % or less.

(Absorbent Fiber)
The absorbent fiber is not particularly limited as long as it is generally used in absorbent articles such as sanitary napkins, paper diapers, and urine pads, and examples thereof include fluff pulp, cotton, rayon, acetate, tissue, absorbent paper, hydrophilic nonwoven fabric, etc. Among these, fluff pulp is preferred from the viewpoint of absorbency. Examples of fluff pulp include wood pulp (e.g., coniferous bleached kraft pulp (N-BKP) such as southern pine and Douglas fir), synthetic fibers, resin fibers, cotton-like defibrated materials such as non-wood pulp, etc.

(First superabsorbent polymer)
The first superabsorbent polymer refers to a superabsorbent polymer commonly used in this field. The superabsorbent polymer is not particularly limited as long as it can absorb body fluids and prevent backflow, and examples thereof include polyacrylates, polyaspartates, (starch-acrylic acid) graft copolymers, (acrylic acid-vinyl alcohol) copolymers, (isobutylene-maleic anhydride) copolymers, and saponification products thereof. Among these, from the viewpoint of the absorption amount per weight, polyacrylates are preferred, polyacrylic acid alkali metal salts are more preferred, and sodium polyacrylate is even more preferred. The superabsorbent polymers can be used alone or in combination of two or more.

The superabsorbent polymer is used in the form of particles, fibers, etc., for example, but is preferably used in the form of particles from the viewpoint of ease of handling, etc. In this case, by avoiding the use of a fine powder of superabsorbent polymer that has poor flowability as a powder and using a superabsorbent polymer with a medium particle size, the basic absorption performance can be improved and the rough feel caused by the skin-side absorbent body 21 and the non-skin-side absorbent body 22 becoming hard can be reduced. The medium particle size of the superabsorbent polymer is, for example, in the range of 50 μm to 600 μm or in the range of 100 μm to 500 μm.

The absorbent fibers and superabsorbent polymers in the skin-side absorbent body 21 and non-skin-side absorbent body 22 may be in the form of, for example, absorbent fibers mixed with SAP particles and molded into a specific shape, or a laminated mat in which absorbent fibers and SAP particles are laminated. Examples of the specific shape include a plate shape, an hourglass shape, a gourd shape, etc.

<Absorbent sheet>
2 to 4, the absorbent sheet 23 is fitted into a recess 24 (a through-hole in this embodiment) having an opening on the skin side of the skin side absorbent body 21, and includes a base nonwoven fabric 11 as a hydrophilic sheet, one surface of which is a raised surface 11a on which a plurality of raised fibers 11x are arranged by a raising process and the other surface of which is a non-raised surface 11b, and a second highly absorbent polymer 12 fixedly supported between the raised fibers 11x to form a bodily fluid absorbent layer. In this embodiment, the base nonwoven fabric 11 is fitted into the recess 24 of the skin side absorbent body 21 so that the non-raised surface 11b of the base nonwoven fabric 11 becomes the skin side of the absorbent sheet 23. In this embodiment, the absorbent sheet 23 is entirely wrapped in a packaging sheet (not shown). By having a raised surface 11a on which a plurality of raised fibers 11x are arranged, the material has excellent cushioning properties and flexibility, and by having spaces between the raised fibers 11x, the material exhibits good bodily fluid diffusion properties and anti-wetback properties even after absorbing bodily fluids multiple times.

The multiple raised fibers 11x standing on the raised surface 11a of the base nonwoven fabric 11 are formed by applying a raising process such as nap processing to the surface of the base nonwoven fabric 11. The multiple raised fibers 11x of the base nonwoven fabric 11 impart a moderate thickness and softness to the absorbent sheet 23 in addition to the bulkiness inherent to the nonwoven fabric, resulting in good cushioning properties and improving the fit and comfort when worn. Furthermore, by raising the base nonwoven fabric 11, the second superabsorbent polymer 12 can be dispersed and fixed between the raised fibers 11x while maintaining the spaces between the raised fibers 11x. Methods for raising one side surface 11a of the base nonwoven fabric 11 include methods using a rotary saw blade, needle punch, etc., and the method using a rotary saw blade is preferred from the viewpoint of in-line productivity and cost.

The degree of raising in the base nonwoven fabric 11 is not particularly limited, and it is sufficient that the raising can be confirmed visually. For example, the raising rate as the degree of raising is in the range of 5% to 90%, or 8% to 80%. The raising rate means the rate of increase in the thickness of the base nonwoven fabric 11 due to the raising process. When the thickness of the base nonwoven fabric 11 before raising is T1 and the thickness of the base nonwoven fabric 11 after raising is T2, the raising rate (%) = [(T2-T1)/T1] x 100. The thicknesses T1 and T2 are measured under no load using a height gauge (manufactured by Mitutoyo Corporation). In addition, the fibers may be raised on the non-raised surface 11b of the base nonwoven fabric 11 as well.

The absorbent sheet 23 has a length dimension in the range of 160 mm to 740 mm, and a width dimension in the range of 60 mm to 150 mm. With these dimensions, the absorbent sheet 23 can easily come into contact with the wearer's crotch area, and can smoothly absorb bodily fluids in response to their excretion. If the length dimension and/or width dimension are less than the respective lower limits mentioned above, the bodily fluids tend to be insufficiently diffused within the absorbent body 20, and the absorption rate tends to decrease. If the length dimension and/or width dimension exceed the respective upper limits mentioned above, the durability during wear is insufficient, and the absorbent sheet 23 tends to easily fall off from the skin-side absorbent body 21.

The hydrophilic sheet constituting the base nonwoven fabric 11 is composed of a hydrophilic air-through nonwoven fabric that has a water permeability of 10 points or more the first time and 9 points or more the second time, as measured by the hydrophilicity measurement method described below, and the hydrophilic air-through nonwoven fabric has a basis weight of 55 g/m2 ^{or more} and 110 g/m2 ^or less, the basis weight of the second superabsorbent polymer 12 fixedly supported between the multiple raised fibers 11x on the raised surface 11a is 70 g/m2 or ^more and 320 g/m2 ^or less, the apparent specific volume of the base nonwoven fabric 11 with no load on the raised surface 11a is 35 ^cm3 /g or more and 120 ^cm3 /g or less, and further, when the entire absorbent article 50 is placed or placed on a smooth flat surface without being folded, the step between the skin side of the skin-side absorbent body 21 and the skin side of the absorbent sheet 23 is 0.5 mm or less under a load of 35 g/ ^cm2 . The apparent specific volume is calculated by dividing the thickness of one sheet of the base nonwoven fabric 11 by the basis weight, and is expressed in ^cm3 per gram.

By setting the basis weight of the second superabsorbent polymer 12 forming the bodily fluid absorbent layer on the raised surface 11a of the base nonwoven fabric 11 and/or the apparent specific volume of the base nonwoven fabric 11 in a no-load state on the raised surface 11a within the above-mentioned ranges, it is possible to maintain a high level of absorption performance such as absorption amount and absorption speed without causing inconvenience such as gel blocking or deterioration in fit from the start to the end of use of the absorbent article 50. In addition, regarding the step between the skin side of the skin-side absorbent body 21 and the skin side of the absorbent sheet 23, the load of 35 g/ ^cm2 is the average body pressure applied to the absorbent body 20 when the absorbent article 50 is worn. Therefore, it indicates that the step between the skin side of the skin-side absorbent body 21 and the skin side of the absorbent sheet 23 is 0.5 mm or less when the absorbent article 50 is worn. If the step is 0.5 mm or less, it is significantly suppressed from causing skin troubles to the wearer.

(Method of measuring hydrophilicity)
1. Test item: Repeated point absorption 2. Aim of the repeated point absorption test When a certain amount of test liquid is injected at a certain point of the specimen at a certain time interval, the degree of repeated absorption is confirmed. The higher the hydrophilicity, the more times it can be repeatedly absorbed.
3. Repeated point absorption test method As shown in Figure 9, a specimen 60 is placed on a mount 61 made of 2 sheets of absorbent paper x 5 sets = 10 sheets stacked together, a 10-point measurement plate 62 is placed on top, and one drop (0.05 mL) of 37°C 0.9% saline urine is dropped at 10 points using a dropper 63, and the number of points absorbed within 2 seconds is counted and used as the number of times water is permeated. Drops are dropped repeatedly at the same points every 3 minutes.

As shown in FIG. 3, the absorbent sheet 23 of this embodiment is provided in a substantially band-like shape with a planar shape extending in the length direction so as to correspond to the recess 24 (the through-hole in this embodiment) formed to extend from one end in the length direction to the other end, leaving both ends in the width direction of the skin-side absorbent body 21. This is the same as the combination of the skin-side absorbent body 21a and the absorbent sheet 23a shown in FIG. 5(a). The combination of the skin-side absorbent body 21 and the absorbent sheet 23 is not limited to this embodiment, and may be a combination of the skin-side absorbent body 21b having a rectangular planar recess whose length dimension is longer than its width dimension and arranged in the center of each of the length direction and the width direction, and the absorbent sheet 23b having a planar shape corresponding to the planar shape of the recess (FIG. 5(b)), the skin-side absorbent body 23c having two rectangular recesses whose length dimension is longer than their width dimension arranged at a predetermined interval in the length direction, and the absorbent sheet 23b having a planar shape corresponding to the planar shape of the recess (FIG. 5(c)). Examples of such combinations include a combination with an absorbent sheet 23c (Fig. 5(c)), a combination of a skin-side absorbent body 21d having a rectangular recess that is longer in the width direction than in the length direction and provided at the rear side that contacts the wearer's crotch to buttocks, and an absorbent sheet 23d having a planar shape corresponding to the planar shape of the recess described above (Fig. 5(d)), and a combination of a skin-side absorbent body 21e having a narrow band-shaped recess that extends in a band-like shape in the center of the length direction, and an absorbent sheet 23e having a planar shape corresponding to the planar shape of the recess described above (Fig. 5(e)).

(Second superabsorbent polymer)
The second superabsorbent polymer 12 is a superabsorbent polymer commonly used in this field, similar to the first superabsorbent polymer. Therefore, as the second superabsorbent polymer 12, various superabsorbent polymers exemplified as the first superabsorbent polymer can be used in the same embodiment as the first superabsorbent polymer. For example, a hot melt adhesive is used to fix and support the second superabsorbent polymer 12 to the raised fiber 11x. As the hot melt adhesive, those having a melting point of 100°C or more and 180°C or less can be used without any particular limitation, and examples thereof include synthetic rubber-based hot melt adhesives such as styrene-butadiene-styrene copolymers and styrene-isoprene-styrene copolymers, and olefin-based hot melt adhesives such as ethylene-vinyl acetate copolymers. As a method for applying the hot melt adhesive, known methods such as a curtain coat method or a spiral method in which a molten hot melt adhesive is applied from a nozzle in a non-contact manner, and a slot method in which a contact method is applied can be used. The content of the hot melt adhesive is, for example, in the range of 10 g/m ² or less from the viewpoint of not impairing the absorbency of the highly absorbent polymer and the feel on the skin when worn.

In a preferred embodiment of the absorbent sheet 23, the low basis weight region has a basis weight of the second superabsorbent polymer 12 of 30 g/m ² or less in a range of 10% to 20% of the length direction dimension. In FIG. 6, in an absorbent sheet 23e extending in a narrow strip shape in the length direction shown in FIG. 5(e), a low basis weight region 26 is formed between normal basis weight regions 25, and the ratio of the length direction dimension of the low basis weight region 26 to the length direction dimension of the absorbent sheet 23e is configured to be in a range of 10% to 20%. According to this embodiment, even after multiple body fluid absorptions, the flexibility and mobility of the absorbent sheet 23e are unlikely to decrease, and the absorbent article 50 as a whole maintains better wearability. If the aforementioned ratio is less than 10%, the effect of providing the low basis weight region 26 tends to be insufficient. If the aforementioned ratio exceeds 20%, the absorption performance of the absorbent body 20 as a whole tends to decrease.

In another preferred embodiment of the absorbent sheet 23, the vortex speed of the first superabsorbent polymer used in the skin-side absorbent body 21 is 30 seconds or more and 70 seconds or less, and the vortex speed of the second superabsorbent polymer 12 used in the absorbent sheet 23 is 1 second or more and 30 seconds or less. According to this embodiment, even after multiple body fluid absorptions, the flexibility and mobility of the absorbent sheet 23 are less likely to decrease, and the absorbent article 50 as a whole maintains better wearability. Superabsorbent polymers with various vortex speeds, which are produced by selecting the manufacturing method and raw materials, are commercially available, so it is sufficient to select one that fits each of the above-mentioned ranges as appropriate.

The vortex absorption rate (seconds) of the superabsorbent polymer is determined by pouring 50.0 ml (±0.5 ml) of saline solution with a concentration of 0.900% (±0.009%) and a temperature of 25°C (±2°C) into an experimental glass container, then stirring at 600 rpm (±30 rpm) until the saline solution in the container forms a vortex. Then, 2.00 g (±0.02 g) of superabsorbent polymer is poured into the container, and the time (seconds) from the moment the superabsorbent polymer 12 is poured into the container until the vortex disappears and the liquid level becomes horizontal is measured.

(packaging sheet)
The packaging sheet is a hydrophilic sheet, and is provided as necessary so as to wrap the entire absorbent sheet 23. The packaging sheet, for example, diffuses the body fluid almost uniformly throughout the body fluid absorbent layer, and prevents the second superabsorbent polymer 12 from falling off from the body fluid absorbent layer. When wrapping the absorbent sheet 23 in the packaging sheet, for example, a method may be used in which the body fluid absorbent layer of the absorbent sheet 23 is placed near the center of the width of the packaging sheet, and the packaging sheet and the body fluid absorbent layer are bonded together with a hot melt adhesive or the like as necessary, and then both widthwise ends of the packaging sheet are folded toward the non-raised surface 11b of the absorbent sheet 23 to form a C-fold.

As the hydrophilic sheet constituting the packaging sheet, any sheet commonly used in this field can be used, and examples thereof include hydrophilic nonwoven fabrics such as thermal bonded nonwoven fabrics, spunbonded nonwoven fabrics, airlaid nonwoven fabrics, air-through nonwoven fabrics, pulp-containing nonwoven fabrics, tissue paper, absorbent paper, etc. Among hydrophilic nonwoven fabrics, hydrophilic nonwoven fabrics such as thermal bonded nonwoven fabrics, spunbonded nonwoven fabrics, air-through nonwoven fabrics, pulp-containing nonwoven fabrics, etc. are more preferred, and air-through nonwoven fabrics, pulp-containing nonwoven fabrics, spunbonded nonwoven fabrics, etc. are even more preferred. The thickness of the packaging sheet is in the range of 0.10 mm to 0.25 mm, and the basis weight is in the range of 5 g/ ^m2 to 40 g/ ^m2 .

<Back seat>
The back sheet 30 may be formed using a liquid-impermeable substrate that prevents body fluids held by the absorbent 20 from wetting clothing, and examples of the substrate include a resin film and a composite sheet that is a laminate of a resin film and a nonwoven fabric. The nonwoven fabric used in the composite sheet is not particularly limited in its manufacturing method, and examples thereof include single-layer nonwoven fabrics such as spunbond nonwoven fabrics and meltblown nonwoven fabrics, composite nonwoven fabrics such as spunbond nonwoven fabrics/meltblown nonwoven fabric laminates, and composite materials thereof. Examples of the resin film include polyester, polyvinyl alcohol, polyethylene, polypropylene, and composite films of polyethylene and polypropylene.

The basis weight of the back sheet 30 is, for example, in the range of 15 g/ ^m2 to 60 g/ ^m2 in terms of strength and processability. In order to prevent stuffiness during wear, it is preferable that the back sheet 30 is breathable. In order to provide the back sheet 30 with breathability, for example, a filler may be blended into the resin film of the base material, or the back sheet 30 may be embossed. An example of the filler is calcium carbonate, and the blending method may be any known method without any restrictions.

<3D gathers>
The three-dimensional gathers 40 are fixed to the skin side of the top sheet 10 along the length of the absorbent article 50 near both ends in the width direction of the absorbent article 50 in order to prevent, for example, lateral leakage of bodily fluids excreted by the wearer of the absorbent article 50. The three-dimensional gathers 40 include an elastic stretch member 40a and a water-repellent and/or waterproof sheet member 40b.

The elastic stretch member 40a is disposed along the length of the sheet member 40b near the free end (other end), imparting uprightness to the free end, and allowing the free end and the area nearby to be deformed to fit the wearer's body shape. In this embodiment, the sheet member 40b has one widthwise end (fixed end) fixed near both widthwise ends of the skin side of the back sheet 30, a middle part in the widthwise direction fixed near both widthwise ends of the skin side of the top sheet 10, and the other widthwise end being a free end having uprightness. The fixing position of the fixed end (one widthwise end) of the sheet member 40b is not limited to this embodiment, and examples include the non-skin side of the back sheet 30, the skin side or non-skin side near both widthwise ends of the joint between the top sheet 10 and the back sheet 30, which contains the absorbent body 20 inside, and the skin side near both widthwise ends of the top sheet 10.

The sheet member 40b is a water-repellent and/or waterproof sheet, and is made of, for example, a nonwoven fabric. As the nonwoven fabric for the first sheet member, any water-repellent and/or waterproof (liquid-impermeable) nonwoven fabric formed of hydrophobic fibers can be used without any particular limitation, and examples thereof include spunbond nonwoven fabric, meltblown nonwoven fabric, and composite nonwoven fabric (SMS nonwoven fabric) which is a spunbond nonwoven fabric/meltblown nonwoven fabric/spunbond nonwoven fabric laminate. The basis weight of the sheet member 40b is, for example, in the range of 13 g/m ² or more and 20 g/m ² or less. As the elastically stretchable member 40a, for example, a thread-like, string-like, or strip-like material made of natural rubber, synthetic rubber, polyurethane, or the like can be appropriately used.

<Method of manufacturing absorbent articles>
The absorbent article 50 can be manufactured by a known manufacturing method, for example, a manufacturing method including a step of arranging the absorbent body 20 between the top sheet 10 and the back sheet 30, a step of fixing the top sheet 10 and the back sheet 30 partially or entirely around the periphery using a hot melt adhesive, heat embossing, ultrasonic embossing, high frequency embossing, or the like, and a step of providing three-dimensional gathers 40 at predetermined positions on the back sheet 30 and the top sheet 10. When the absorbent article 50 is a urine absorption pad or a light incontinence pad, it may be individually packaged in a package and then folded in thirds in the longitudinal direction. Leg gathers, waist gathers, side flaps, and the like may be provided as necessary.

Although the present invention has been described above using embodiments, it goes without saying that the technical scope of the present invention is not limited to the scope described in the above embodiments and examples. It will be clear to those skilled in the art that various modifications and improvements can be made to the above embodiments. Furthermore, it is clear from the claims that forms incorporating such modifications or improvements can also be included in the technical scope of the present invention.

The following examples and comparative examples will explain this embodiment in more detail.

(Examples 1 to 4 and Comparative Examples 1 to 7)
Each absorbent article (urine pad) of Examples ^{1 to 4} and Comparative Examples 1 to 7 was produced using an air-through nonwoven fabric (basis weight 25 g/ ^m2 ) as the top sheet, an absorbent body having the configuration shown in Tables 1 and 2 (the raised surface was physically raised with a rotary saw blade to give a specified apparent specific volume (cm3/g)), a breathable polyethylene sheet (basis weight 30 g/ ^m2 ) as the liquid-impermeable back sheet, and a composite nonwoven fabric (basis weight 15 g/ ^m2 ) which is a laminate of spunbond nonwoven fabric/meltblown nonwoven fabric/spunbond nonwoven fabric as the three-dimensional gathers.

In Comparative Example 1, no absorbent sheet was used, and only a fluff absorbent body containing fluff pulp and a highly absorbent polymer was used. In Comparative Example 2, an absorbent sheet was placed on the skin side of the skin-side absorbent body. Comparative Examples 3 to 7 have the configurations shown in Tables 1 and 2.

The urine absorption pads of Examples 1 to 4 and Comparative Examples 1 to 7 obtained above were used in combination with tape-fastened disposable diapers to carry out the following evaluations. The results are shown in Table 3.

<Monitor evaluation after wearing for one week>
With the cooperation of eight disposable diaper wearers (user monitors) who spend their daily lives mainly in a lying position (supine position) and eight caregiver monitors who assist the user monitors, the user monitors observed the comfort and fit (softness of wear, ease of movement) of each urine absorption pad of Examples 1 to 4 and Comparative Examples 1 to 7 when worn in combination with a tape-fastened disposable diaper, and the caregiver monitors observed the skin condition of the wearer, and evaluated them according to the following criteria. The wearers used the pads for 8 hours each time for one week, and the evaluation was performed during daily activities such as changing posture when sleeping, eating, and undressing.
When 6 or more and 8 or less people rated "good, comfortable to wear, and no redness on the skin", the rating was given as "O", when 3 or more and 5 or less people rated "good, comfortable to wear, and no redness on the skin", the rating was given as "△", and when 2 or less people rated "good, comfortable to wear, and no redness on the skin", the rating was given as "X".

<Absorption speed>
The urine absorption pad was fixed in a flat, unfolded state, and a cylindrical absorption rate tool with an inner diameter of 30 mm was placed at the center of the width and length of the skin contact side of the urine absorption pad, and 150 ml of 0.9% saline was poured in each time, and the time until the liquid level was absorbed on the surface of the paper diaper was measured. 3 minutes after absorption, the next 150 ml was poured in, and the time until absorption was measured in the same manner. This operation was repeated, and the total time required for absorption of 150 ml x 3 times was taken as the absorption rate (seconds). Measurement was performed under a pressure of 35 g/ ^cm2 due to the weight of the absorption rate tool.

<Gap between the skin-side absorbent body and absorbent sheet>
After the absorption rate measurement, the thickness of each of the skin-side absorbent body and absorbent sheet was measured under a load of 35 g/ ^cm2 using a height gauge (product name, manufactured by Mitutoyo Corporation), and the difference in thickness between the skin-side absorbent body and the absorbent sheet was calculated and recorded as the step.

<Return amount>
The urine pad was stretched flat and fixed in an open state, and 150 ml of 0.9% saline was poured into the center of the width and length of the rear side of the skin side of the urine pad (the area that contacts the wearer's crotch and buttocks) at 3-minute intervals 8 times, and left to stand for 10 minutes after the water was poured. Filter paper was placed in the center of the width and length of the skin side of the urine pad, and a weight of 35 g/m2 was placed on top of it and left to stand for 1 minute. After leaving it to stand for 1 minute, the weight was removed, and the weight of 0.9% saline absorbed by the filter paper was calculated from the weight difference before and after absorption, and was taken as the return amount (wet back, g).

Example 1
By providing a large absorbent sheet in one central location on the skin-side absorbent body as shown in Fig. 5(a), good monitoring results were obtained after long-term use. It is believed that the good skin condition was due to the fact that the absorbency of the absorbent article surface was increased by embedding the absorbent sheet, while the occurrence of unevenness and steps was suppressed.
Example 2
As shown in Figure 5(b), even when two small absorbent sheets were provided at intervals in the longitudinal direction of the skin-side absorbent body, good monitoring results were obtained after long-term use. In particular, male wearers (4/8 people) commented that they felt less urine running down the skin and staying inside the absorbent article. It is believed that the diffusion of the front side was good even after absorption.
Example 3
By providing a slit-shaped absorbent sheet extending longitudinally through the widthwise center of the skin-side absorbent body as shown in Figure 5 (e), the swelling around the sacrum after absorption in the supine position was suppressed, and effective absorption was achieved even under body pressure, maintaining good skin condition.
Example 4
In the absorbent sheet shown in Fig. 5(e), a comment was received that the feeling of pressure after wearing for a long time was slightly reduced when an absorbent sheet having a non-supporting region of superabsorbent polymer formed as shown in Fig. 6 was used. It is considered that the non-supporting region maintained flexibility in the length direction even after the superabsorbent polymer swelled due to the absorption of bodily fluids, suppressing the decrease in wearing comfort.
In addition, the absorbent articles according to Examples 1 to 4 reduce costs compared to the case where the absorbent body is made of three layers.
(Comparative Example 1)
Since this absorbent does not use an absorbent sheet and contains fluff pulp and highly absorbent polymer, it was evaluated that there was no difference in level between different absorbents. The absorbency of the surface was insufficient when used for a long time, the amount of return increased after repeated absorption, and redness was observed on the skin after wearing.
(Comparative Example 2)
When an absorbent sheet was placed on the skin side of the skin-side absorbent body, the absorbency was high, but after absorbing body fluids and swelling, the difference in height between the skin-side absorbent body and the absorbent sheet became large, resulting in a decrease in comfort and redness of the skin at the pressure points. The cost was also relatively high.
(Comparative Example 3)
When an absorbent sheet having a basis weight and volume ratio of the superabsorbent polymer different from those of the present embodiment was used, the absorbent sheet did not support enough superabsorbent polymer, and the physical stress of wearing the absorbent sheet for an extended period of time caused the placement of the superabsorbent polymer to become uneven, resulting in unevenness and a feeling of pressure in some areas after swelling.
(Comparative Example 4)
When two absorbent sheet units were embedded in the skin-side absorbent body in the width direction, the two pairs of absorbent sheets on the left and right sides peeled off from the skin-side absorbent body due to long-term absorption and wearing stress, and absorbency and wearing comfort could not be maintained.
(Comparative Example 5)
When the basis weight of the diffusion sheet was lower than the specified range, diffusion of body fluids over the entire area of the skin-side absorbent was insufficient, and sufficient absorption performance was not obtained during repeated absorption over long periods of use, resulting in redness of the skin.
(Comparative Example 6)
When an absorbent sheet was placed inside the non-skin side absorbent core, no improvement in absorbency was observed due to the placement of the absorbent sheet, and the wearing comfort was somewhat reduced due to swelling from the non-skin side.
(Comparative Example 7)
Instead of the absorbent sheet made of spunbonded nonwoven fabric folded in a C shape in Example 1, an absorbent sheet was used in ^which two superabsorbent polymer carrying layers were provided between each of three layers of non-brushed nonwoven fabric [air-through nonwoven fabric (basis weight 20 g/ ^m2 ) + air-through nonwoven fabric (basis weight 20 g/ ^m2 ) + spunlace nonwoven fabric (basis weight 35 g/m2)] and the spunbonded nonwoven fabric was not folded in a C shape. Although the backflow was reduced, the swelling in the thickness direction due to the swelling of the superabsorbent polymer after absorbing body fluids became large, and a relatively large difference in level was created between the skin side of the skin-side absorbent body and the skin side of the absorbent sheet, resulting in a poor wearing comfort and affecting the skin condition after wearing.

REFERENCE SIGNS LIST 10 top sheet 11 base nonwoven fabric 11a raised surface 11b non-raised surface 11x raised fiber 12 second superabsorbent polymer 15 diffusion sheet 20 absorbent body 21, 21a, 21b, 21c, 21d, 21e skin side absorbent body 22 non-skin side absorbent body 23, 23a, 23b, 23c, 23d, 23e absorbent sheet 24 recess (through portion)
25 Normal basis weight area 26 Low basis weight area 30 Back sheet 40 Three-dimensional gather 50 Absorbent article 60 Sample 61 Mount 62 10-point method measurement plate 63 Dropper

Claims (2)

An absorbent article used as an inner pad, comprising a liquid-permeable top sheet, a liquid-impermeable back sheet, and an absorbent body disposed therebetween,
The length direction dimension is 600 mm or more and 800 mm or less, and the maximum width direction dimension is 300 mm or more and 400 mm or less,
the absorbent body includes a skin-side absorbent body arranged on the skin side and a non-skin-side absorbent body arranged on the non-skin side, the skin-side absorbent body and the non-skin-side absorbent body each containing absorbent fibers and a first highly absorbent polymer;
the skin-side absorbent body has an absorbent sheet embedded in a widthwise central portion of a skin-side surface layer of the skin-side absorbent body, the absorbent sheet being a bulky hydrophilic sheet having one side raised to support a second superabsorbent polymer, the absorbent sheet having a lengthwise dimension of 160 mm or more and 740 mm or less and a widthwise dimension of 60 mm or more and 150 mm or less;
the skin-side absorbent body has a minimum widthwise dimension equal to or larger than the widthwise dimension of the non-skin-side absorbent body, a maximum widthwise dimension of 230 mm or more and 360 mm or less, a minimum widthwise dimension of 120 mm or more and 250 mm or less, and a lengthwise dimension of 470 mm or more and 740 mm or less, the absorbent fiber has a basis weight of 180 g/ ^m2 or more and 390 g/m2 ^or less, and the first superabsorbent polymer has a basis weight of 70 g/m2 or ^more and 270 g/m2 ^or less,
the hydrophilic sheet is composed of a hydrophilic air-through nonwoven fabric having a water permeability of 10 points or more the first time and 9 points or more the second time, as measured by the hydrophilicity measurement method described below; the hydrophilic air-through nonwoven fabric has a basis weight of 55 g/m2 or ^more and 110 g/m2 ^or less, the normal basis weight of the second superabsorbent polymer on the raised one side surface is 70 g/m2 or ^more and 320 g/m2 ^or less, and the apparent specific volume of the raised one side surface in an unloaded state is 35 ^cm3 /g or more and 120 ^cm3 /g or less;
When the absorbent article is placed on a flat, smooth surface, the difference in level between the skin side of the skin-side absorbent body arranged on the skin side and the skin side of the absorbent sheet is 0.5 mm or less under a load of 35 g/ ^cm2 ;
a diffusion sheet made of a hydrophilic sheet is disposed between the top sheet and the skin-side absorbent body, the diffusion sheet having a basis weight of 30 g/m2 or ^more and 70 g/m2 or ^less ,
An absorbent article, wherein the vortex speed of the first superabsorbent polymer used in the skin-side absorbent body is 30 seconds or more and 70 seconds or less, and the vortex speed of the second superabsorbent polymer used in the absorbent sheet is 1 second or more and 30 seconds or less .
(Method of measuring hydrophilicity)
Place the sample on 2 sheets of absorbent paper x 5 sets = 10 sheets, and place the 10-point measurement plate on top. Drop one drop (0.05 mL) of 0.9% saline solution at 37°C onto each of the 10 points, and count the number of points absorbed within 2 seconds as the number of times water permeates. Drop the solution onto the same points repeatedly every 3 minutes. 2. The absorbent article of claim 1, wherein the absorbent sheet has an area in which the second superabsorbent polymer has a basis weight of 30 g/ ^m2 or less between areas of normal basis weight, within a range of 10% to 20% of its longitudinal dimension.