JP7488660B2 - Absorbent articles - Google Patents

Description

The present invention relates to an absorbent article.

Absorbent articles generally comprise a liquid-permeable top sheet, a liquid-impermeable back sheet, and an absorbent body disposed between them, and the absorbent body absorbs and retains bodily fluids such as urine that permeate the top sheet. There are various types of absorbent articles for both adults and infants, depending on the intended use, such as tape-type disposable diapers, pants-type disposable diapers, urine pads, and light incontinence pads.

Conventionally, fluff pulp and super absorbent polymer (hereinafter referred to as "SAP") have been used together as an absorbent. However, in order to further improve the wearing comfort, appearance, and feel of absorbent articles, and to further reduce the backflow of body fluids such as urine, various absorbent articles have been proposed that use a super absorbent sheet (hereinafter referred to as "SAP sheet") containing two sheets of nonwoven fabric and SAP particles fixed between them with a hot melt adhesive.

For example, Patent Document 1 discloses a highly absorbent sheet comprising first and second nonwoven fabrics, each having one surface coated with an adhesive, and a plurality of SAP layers arranged in stripes extending in the longitudinal direction between the adhesive-coated surfaces of the first and second nonwoven fabrics, in which adhesive is intermittently applied to the area of the adhesive-coated surface of the second nonwoven fabric facing the SAP layer, and adhesive is continuously applied in the longitudinal direction to the adhesive-coated surfaces of the first and second nonwoven fabrics that directly face the SAP layer on both widthwise sides without an SAP layer between them.

Patent Document 2 discloses a highly absorbent sheet in which the absorbent disposed between the top sheet and the back sheet comprises first and second absorbents, each of which comprises two sheets of nonwoven fabric with SAP particles disposed therebetween, and the first and second absorbents disposed on one side and the other in the width direction have first and second folds extending in the longitudinal direction, respectively, and the first and second folds face each other. Furthermore, Patent Document 2 discloses an absorbent article further comprising a third absorbent comprising two sheets of nonwoven fabric with SAP particles disposed therebetween, the third absorbent being disposed above the first and second absorbent bodies.

JP 2006-158676 A JP 2013-42882 A (Claim 1, Claim 5)

The SAP sheets used in Patent Documents 1 and 2 and many other absorbent articles have poor compressibility in the thickness direction, so that the wearer is likely to feel the rough and hard feel of the SAP particles and the hardened body of the hot melt adhesive on the skin, significantly reducing the wearing comfort and fit and causing a great sense of discomfort when wearing the article. Furthermore, in many SAP sheets, the SAP particles are fixed to the nonwoven fabric with a hot melt adhesive, so that the SAP particles are present at a high density on the surface, resulting in less space for the SAP particles to absorb body fluids and expand. For this reason, conventional SAP sheets are not fully satisfactory in terms of the diffusion and absorption speed of body fluids, and ultimately the absorbency.

The object of the present invention is to provide an absorbent article that is equipped with a highly absorbent sheet, has a good wearing feeling and fit, and has excellent diffusion and absorption speed of bodily fluids.

As a result of intensive research into solving the above problems, the inventors have succeeded in obtaining an absorbent article equipped with a highly absorbent sheet in which a highly absorbent polymer is fixed between nonwoven fabrics with a hot melt adhesive, and which can solve the problems of conventional highly absorbent sheets, thereby completing the present invention. As preferred embodiments, the present invention provides the following absorbent articles (1) to (5).

(1) An absorbent article comprising a liquid-permeable top sheet, a liquid-impermeable back sheet, and an absorbent body disposed between the top sheet and the back sheet,
The absorbent article comprises a base nonwoven fabric having a brushed surface and a non-brushed surface, the non-brushed surface being arranged facing the top sheet, a highly absorbent sheet including a highly absorbent polymer fixedly supported between the brushed fibers on the brushed surface of the base nonwoven fabric, and a hydrophilic sheet covering the brushed surface of the base nonwoven fabric, the hydrophilic sheet including a first air-through nonwoven fabric having a bending stiffness of 0.02 gf· ^cm2 /cm or more and 0.6 gf· ^cm2 /cm or less.
(2) The absorbent article according to claim 1, wherein the hydrophilic sheet has a three-dimensional shape inwardly folded in three so that both widthwise end faces thereof face each other between the top sheet and the base nonwoven fabric, and cover both widthwise end faces of the base nonwoven fabric together with the raised surface of the base nonwoven fabric.
(3) The absorbent article according to (1) or (2) above, wherein the hydrophilic sheet is stretched in the width direction so that both widthwise ends cover and overlap the non-raised surface of the base nonwoven fabric, and the width dimension of the overlap is 5% to 50% of the width dimension of the absorbent body.
(4) The absorbent article according to any one of (1) to (3) above, wherein the first air-through nonwoven fabric has a basis weight of 20 g/ ^m2 or more and 100 g/ ^m2 or less.
(5) The absorbent article according to any one of (1) to (4) above, wherein the base nonwoven fabric is a second air-through nonwoven fabric, the basis weight of the second air-through nonwoven fabric is 20 g/ ^m2 or more and 80 g/ ^m2 or less, and the thickness of the fibers constituting the second air-through nonwoven fabric is 1.6 dtex or more and 14 dtex or less.
(6) The absorbent article according to any one of (1) to (5) above, wherein the basis weight of the superabsorbent polymer in the superabsorbent sheet is 200 g/ ^m2 or more and 1200 g/ ^m2 or less.

The present invention provides an absorbent article that is equipped with a highly absorbent sheet, has a good wearing comfort and fit, and has excellent diffusion and absorption speed of bodily fluids.

1 is a plan view illustrating a schematic configuration of an absorbent article according to a first embodiment of the present invention. FIG. 2 is a perspective view showing a schematic configuration of a base nonwoven fabric provided in the absorbent article shown in FIG. 1 . FIG. 2 is a side view showing a schematic configuration of a highly absorbent sheet provided in the absorbent article shown in FIG. 1 . FIG. 2 is a cross-sectional view showing a schematic configuration of an absorbent body provided in the absorbent article shown in FIG. 1 . FIG. 11 is a cross-sectional view showing a schematic configuration of an absorbent body according to another embodiment.

The absorbent article 50 of this embodiment will be described in more detail below with reference to the drawings. Fig. 1 is a schematic plan view of the absorbent article 50 from the top sheet 25 side. Fig. 2 is a schematic perspective view of the base nonwoven fabric 11. Fig. 3 is a schematic side view of the highly absorbent sheet 10. Figs. 4 and 5 are schematic cross-sectional views of the absorbents 1 and 2, respectively. In each figure, the components are shown to be in close contact with each other, but there may be one or more gaps between at least one of the components. In addition, each figure does not specify the size relationship between the components of the absorbent article 50.

The longitudinal direction of the absorbent article 50 is the direction indicated by Y in the figure, which extends from the front to the back of the body through the crotch area of the wearer when the absorbent article 50 is worn. The width direction of the absorbent article 50 is the direction indicated by X in the figure, which is perpendicular to the longitudinal direction. The thickness direction of the absorbent article 50 is the direction indicated by Z in the figure, in which each component, such as the top sheet 25, absorbent body 1, and back sheet 30, is laminated. The skin side of the absorbent article 50 and each component contained therein is the surface that contacts the wearer's skin and faces the skin, 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>
The absorbent article 50 of this embodiment can be used as various absorbent articles for babies or adults, and representative examples include light incontinence pads, urine absorption pads, pants-type paper diapers, tape-fastened paper diapers, etc. Various paper diapers as outerwear may be combined with the absorbent article 50 as innerwear. The longitudinal and width dimensions of the absorbent article 50 are not particularly limited, but are, for example, in the ranges of 100 mm to 800 mm and 50 mm to 500 mm, respectively. By adjusting the dimensions of the absorbent article 50 to fall within the above ranges, absorbent articles for various uses can be obtained.

As shown in FIG. 1, the absorbent article 50 of this embodiment includes a liquid-permeable top sheet 25 that is located relatively close to the skin when worn, a liquid-impermeable back sheet 30 that is arranged opposite the top sheet 25 and is located relatively close to the skin when worn, an absorbent body 1 that is arranged between the top sheet 25 and the back sheet 30, and a pair of three-dimensional gathers 40 that are provided on the skin-side surface of the top sheet 25. The absorbent body 1 is sandwiched between the top sheet 25 and the back sheet 30, and body fluids such as urine are absorbed and retained in the absorbent body 1 through the top sheet 25. Leg gathers, waist gathers, side flaps, etc. can be appropriately provided depending on the purpose and type of the absorbent article 50. The absorbent article 50 of this embodiment includes a form in which the absorbents 1 and 2 do not contain fluff pulp, the return of body fluids such as urine is suppressed, a smooth and comfortable feel is maintained, and the absorbency of body fluids, wearing comfort, and fit are good, and there is no discomfort when wearing it.

The sheet-like or plate-like components are described in more detail below in the order of the top sheet 25, absorbent body 1, back sheet 30, and three-dimensional gathers 40. Note that these components may have a three-dimensional structure other than a sheet or plate shape.

(Top sheet)
The top sheet 25 is a liquid-permeable sheet-like member that quickly passes bodily fluids toward the absorbent body 1, and is disposed opposite the back sheet 30 with the absorbent body 1 sandwiched therebetween. Since the top sheet 25 may come into contact with the wearer's skin, a substrate that is soft to the touch and does not irritate the skin is preferable. Examples of the substrate include hydrophilic nonwoven fabrics, composite nonwoven fabrics that are laminates of the same or different hydrophilic nonwoven fabrics, open-type films such as open-type polyethylene films, and foamed films such as urethane foam. Hydrophilic nonwoven fabrics can be obtained by processing synthetic fibers made of synthetic resins such as polypropylene and polyethylene, regenerated fibers such as rayon, and natural fibers such as cotton using known methods such as the air-through method, the thermal bond method, the spunlace method, and the spunbond method.

The top sheet 25 may be embossed or perforated on its surface to improve liquid permeability. Any known method may be used to perform the embossing or perforation without restriction. The top sheet 25 may contain lotions, antioxidants, anti-inflammatory ingredients, pH adjusters, antibacterial agents, moisturizers, etc. to reduce irritation to the skin.

From the viewpoints of strength, processability, and liquid return, the basis weight of the top sheet 25 is preferably 15 g/m ² or more and 40 g/m ² or less. The shape of the top sheet 25 is not particularly limited, and may be any shape that covers the absorbent body 1 and is necessary to guide bodily fluids to the absorbent body 1 without leakage.

(Absorber)
The absorbent body 1 of this embodiment includes a highly absorbent sheet 10 and a hydrophilic sheet 20, as shown in Figures 2 to 4. The highly absorbent sheet 10 includes a base nonwoven fabric 11 having a raised surface 11a and a non-raised surface 11b, and a highly absorbent polymer 12 fixedly supported between the raised fibers 11x on the raised surface 11a of the base nonwoven fabric 11. In the highly absorbent sheet 10, the base nonwoven fabric 11 is disposed such that the non-raised surface 11b faces the top sheet 25. The hydrophilic sheet 20 includes a first air-through nonwoven fabric having a bending stiffness of 0.02 gf ^cm2 /cm or more and 0.6 gf ^cm2 /cm or less, and covers the raised surface 11a of the base nonwoven fabric 11 in the highly absorbent sheet 10. The hydrophilic sheet 20 has a flat sheet-like three-dimensional shape covering the raised surface 11a of the base nonwoven fabric 11, and preferably has a three-dimensional shape folded inward in three so as to cover both widthwise end faces 11A, 11B together with the raised surface 11a of the base nonwoven fabric 11, and more preferably has a three-dimensional shape folded inward in three so that both widthwise end faces 20a, 20b face each other between the top sheet 25 and the base nonwoven fabric 11, and cover both widthwise end faces 11A, 11B together with the raised surface 11a of the base nonwoven fabric 11.

In this embodiment, the absorbent body 1 preferably has a longitudinal dimension of 100 mm or more and 800 mm or less, and more preferably 150 mm or more and 500 mm or less. The widthwise dimension D of the absorbent body 1 is preferably 50 mm or more and 500 mm or less, and more preferably 60 mm or more and 400 mm or less.

In this embodiment, as described above, the hydrophilic sheet 20 covers the raised surface 11a of the base nonwoven fabric 11, preferably covers the raised surface 11a of the base nonwoven fabric 11 and both widthwise end faces 11A, 11B of the base nonwoven fabric 11, and more preferably covers the raised surface 11a of the base nonwoven fabric 11, both widthwise end faces 11A, 11B of the base nonwoven fabric 11, and both widthwise ends and peripheral areas extending in the longitudinal direction of the non-raised surface 11b of the base nonwoven fabric 11. The hydrophilic sheet 20 has a bending stiffness (bending rigidity) of 0.02 gf·cm ² /cm or more and 0.6 gf·cm ² or more. /cm or less, the absorbent body 1 maintains its thinness while being not too soft and having appropriate rigidity, improving the wearing comfort and fit, and this improvement is reflected in the entire absorbent article 50, and when the absorbent body 1 and the absorbent article 50 are mass-produced, the absorbent body 1 is not too soft and has appropriate rigidity, so that the operability is stable, the operation speed does not decrease, and the defective rate is significantly reduced. That is, the present inventors have found that the bending stiffness (bending stiffness) of the hydrophilic sheet 20 covering the napped surface 11a side of the base nonwoven fabric 11 of the highly absorbent sheet 10 has a significant effect on the rigidity of the absorbent body 1 as a whole and the operation stability (operation speed, breakage and occurrence of process defects) during mass production of the absorbent body 1 and the absorbent article 50, and have found that by setting the bending stiffness within a predetermined range, it is possible to achieve a high level of rigidity, reduced breakage, and prevention of process defects without impairing flexibility. If the bending stiffness is less than 0.02 gf· ^cm2 /cm, the rigidity of the absorbent body 1 will be too low, which will tend to increase the susceptibility to breakage, reduce the process speed, and increase the occurrence of process defects. If the bending stiffness exceeds 0.6 gf· ^cm2 /cm, the absorbent body 1 will be too hard, which will decrease the wearability and fit of the absorbent article 50, and will tend to cause greater discomfort when worn.

In addition, according to this embodiment, in the highly absorbent sheet 10, when the highly absorbent polymer 12 is fixed and supported between the raised fibers 11x of the raised surface 11a of the base nonwoven fabric 11, the highly absorbent polymer 12 is supported by the raised surface 11a and the raised fibers 11x, so that the amount of hot melt adhesive used can be reduced and the high density of the highly absorbent polymer 12 is suppressed, and a space can be formed around the highly absorbent polymer 12 in which the polymer 12 can absorb body fluids and expand. As a result, the body fluid diffusion and body fluid absorption speed of the absorbent body 1 as a whole are increased, and the stiff feeling caused by the hot melt adhesive is unlikely to occur. In addition, since the raised surface 11a of the base nonwoven fabric 11, which is a component of the absorbent body 1, is covered with the first air-through nonwoven fabric as the hydrophilic sheet 20, the body fluid is uniformly distributed throughout the absorbent body 1, and the body fluid can be efficiently absorbed using the entire absorbent body 1. Therefore, the absorbent article 50 equipped with the absorbent body 1 has high diffusion and absorption speed of bodily fluids, excellent bodily fluid absorption, and is comfortable to wear.

In addition, according to this embodiment, the absorbent body 1 is configured so that the non-raised surface 11b of the base nonwoven fabric 11 faces the top sheet 25. In particular, as in the absorbent body 2 shown in Figure 5, by configuring the non-raised surface 11b of the base nonwoven fabric 11 so that both widthwise end faces 20a, 20b of the hydrophilic sheet 20 are stretched and overlapped to seal the non-raised surface 11b, the diffusion and absorption speed of bodily fluids are improved even more significantly.

The absorbent body 1 and each of its components are described below.

(Nonwoven Base Fabric)
As shown in Fig. 2, one side surface 11a of the base nonwoven fabric 11 is in a state where the fibers 11x constituting the base nonwoven fabric 11 are raised. Therefore, in addition to the bulkiness inherent to the nonwoven fabric, the highly absorbent sheet 10 is given an appropriate thickness and softness, which generates an appropriate cushioning property and improves the fit when worn. Furthermore, by raising the base nonwoven fabric 11 as described above, the highly absorbent polymer 12 can be dispersed and fixedly supported between the raised fibers 11x of the base nonwoven fabric 11. Methods for raising the one side surface 11a of the base nonwoven fabric 11 include a rotary saw blade and a needle punch, and it is preferable to use a method of raising the fibers by a rotary saw blade from the viewpoint of in-line productivity and cost.

In this embodiment, the state of the raised fabric is not particularly limited, and it is sufficient if the raised state can be visually confirmed. More specifically, the raised rate of the base nonwoven fabric 11 is preferably 5% to 90%, and more preferably 8% to 80%. The raised rate means the rate of increase in the thickness of the base nonwoven fabric 11 due to the raising process. For example, 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 raised rate (%) can be expressed as [(T2-T1)/T1] x 100. The thickness is obtained by measuring the thickness under no load using a height gauge (manufactured by Mitutoyo Corporation). In this embodiment, the other surface 11b of the base nonwoven fabric 11 is a non-raised surface, but this is not limited thereto, and the fibers may be raised.

Examples of the base nonwoven fabric 11 include nonwoven fabrics such as air-through nonwoven fabrics, point-bonded nonwoven fabrics, spunbonded nonwoven fabrics, and melt-blown nonwoven fabrics, as well as composite nonwoven fabrics formed by laminating spunbonded nonwoven fabrics/melt-blown nonwoven fabrics, and spunbonded nonwoven fabrics/melt-blown nonwoven fabrics/spunbonded nonwoven fabrics. Of these nonwoven fabrics, it is preferable to use an air-through nonwoven fabric (second air-through nonwoven fabric), which is easy to obtain bulkiness.

From the viewpoint of a balance between wearing comfort and absorbency, the thickness of the base nonwoven fabric 11 is preferably 0.3 mm to 11.0 mm, more preferably 0.5 mm to 5.0 mm, and even more preferably 0.5 mm to 2.0 mm. The basis weight of the base nonwoven fabric 11 is preferably 20 g/ ^m2 to 200 g/ ^m2 , more preferably 20 g/ ^m2 to 160 g/ ^m2 , and even more preferably 20 g/ ^m2 to 80 g/ ^m2 .

When a second air-through nonwoven fabric is used as the base nonwoven fabric 11, the basis weight of the second air-through nonwoven fabric is 20 g/ ^m2 or more and 80 g/ ^m2 or less, and the thickness of the fibers constituting the second air-through nonwoven fabric is preferably 1.6 dtex or more and 14 dtex or less, more preferably 1.8 dtex or more and 9.0 dtex or less, and even more preferably 2.0 dtex or more and 6.0 dtex or less. By adjusting the thickness of the fibers constituting the second air-through nonwoven fabric within the above range, the superabsorbent polymer 12 can be dispersed and fixed between the raised fibers 11x of the second air-through nonwoven fabric.

(Highly absorbent sheet)
2, the highly absorbent sheet 10 used in the absorbent body 1 of this embodiment has a base nonwoven fabric 11 with one side surface 11a raised, and a highly absorbent polymer 12 fixedly supported between the fibers 11x in the raised portion of the base nonwoven fabric 11. The highly absorbent polymer 12 is dispersed and fixedly supported between the fibers 11x in the raised portion of the base nonwoven fabric 11, and body fluids such as urine are appropriately diffused or held in the base nonwoven fabric 11 around the highly absorbent polymer 12, thereby improving absorption performance and ensuring sufficient absorption performance even without fluff pulp.

(Superabsorbent polymer)
The superabsorbent polymer 12 is not particularly limited as long as it can absorb urine and prevent backflow, and examples thereof include polyacrylates, polyaspartates, (starch-acrylic acid) graft copolymers, (acrylic acid-vinyl alcohol) copolymers, (isobutylene-maleic anhydride) copolymers, and saponified products thereof. Among these, polyacrylates are preferred from the viewpoint of absorption per weight, and sodium polyacrylate is more preferred. From the viewpoint of ensuring the absorption performance required for various absorbent articles, the basis weight of the superabsorbent polymer 12 is preferably 200 g/m ² or more and 1200 g/m ² or less. In addition, from the viewpoint of further improving the absorption performance, the feel after absorption, and the ease of movement of the wearer, the basis weight of the superabsorbent polymer 12 is more preferably 300 g/m ² or more and 900 g/m ² or less.

In addition, by avoiding the use of finely powdered superabsorbent polymer 12, which has poor fluidity as a powder, the basic absorption performance is improved and the rough feel caused by the hardness of the superabsorbent sheet 10 is reduced. From this standpoint, the median particle size of the superabsorbent polymer 12 is preferably 50 μm or more and 600 μm or less, and more preferably 100 μm or more and 500 μm or less.

The superabsorbent polymer 12 is preferably fixed and supported between the fibers 11x of the raised portion of the base nonwoven fabric 11 by the hot melt adhesive, and when the basis weight of the base nonwoven fabric 11 is relatively low, the hot melt adhesive functions particularly effectively to reinforce the fixed support of the superabsorbent polymer 12. The content of the hot melt adhesive is preferably 10 g/m ² or less so as not to inhibit the absorbency of the superabsorbent polymer 12 and not to impair the feel on the skin when worn. As the hot melt adhesive, a synthetic rubber-based hot melt adhesive such as a styrene-butadiene-styrene copolymer or a styrene-isoprene-styrene copolymer, or an olefin-based hot melt adhesive such as an ethylene-vinyl acetate copolymer, having a melting point of 100°C or more and 180°C or less, can be used. As a method for applying the hot melt adhesive, a known method 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, or a slot method in which a contact method is applied can be used.

(hydrophilic sheet)
In the absorbent body 1 of this embodiment, the napped surface 11a of the highly absorbent sheet 10 is bonded to the hydrophilic sheet 20, thereby preventing the highly absorbent polymer 12 from leaking out of the absorbent body 1 and improving the texture when worn. As the hydrophilic sheet 20, a first air-through nonwoven fabric having a bending stiffness of 0.02 gf·cm ² /cm or more and 0.6 gf·cm ² /cm or less is used. The function of the first air-through nonwoven fabric is as described above. The first air-through nonwoven fabric preferably has a basis weight of 20 g/m ² or more and 100 m ² or less. When bonding the napped surface 11a of the highly absorbent sheet 10 to the hydrophilic sheet 20, it is preferable to fix the highly absorbent sheet 10 and the hydrophilic sheet 20 by a hot melt adhesive or a heat embossing process.

<Method of manufacturing absorbent body>
The method for producing the absorbent body 1 is not particularly limited, but the following method can be given as an example: One surface of the base nonwoven fabric 11 is raised using a rotary saw blade or a needle punch.
Thereafter, the superabsorbent polymer 12 is fixed and supported between the fibers in the raised portion of the base nonwoven fabric 11 with a hot melt adhesive or the like to obtain the superabsorbent sheet 10. Thereafter, the raised surface side of the base nonwoven fabric 11 and the hydrophilic sheet 20 are bonded with a hot melt adhesive or the like to obtain the absorbent body.

(Back seat)
The back sheet 30 may be formed using a liquid-impermeable substrate that prevents the body fluid held by the absorbent 1 from wetting clothing, and is formed from a material such as a resin film or a composite sheet in which a resin film and a nonwoven fabric are laminated. The nonwoven fabric used in the composite sheet is not particularly limited in its manufacturing method, and examples thereof include spunbond nonwoven fabric, meltblown nonwoven fabric, composite nonwoven fabric in which spunbond nonwoven fabric/meltblown nonwoven fabric, spunbond nonwoven fabric/meltblown nonwoven fabric/spunbond nonwoven fabric are laminated, and composite materials thereof. Examples of the resin film include polyester, polyvinyl alcohol, polyethylene, polypropylene, and composite films of polyethylene and polypropylene.

From the viewpoint of strength and processability, the basis weight of the back sheet 30 is preferably 15 g/ ^m2 or more and 40 g/ ^m2 or less. In order to prevent stuffiness during wearing, it is preferable that the back sheet 30 has breathability. 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 to perforate it. An example of the filler is calcium carbonate, and the blending method may be a known method without any restrictions.

(3D gathers)
1, the absorbent article 50 is provided with a pair of three-dimensional gathers 40 at both ends of the skin side surface of the top sheet 25 along the longitudinal direction of the absorbent article 50 in order to prevent side leakage of bodily fluids excreted by the user. The three-dimensional gather sheet is arranged such that one end of the three-dimensional gathers 40 in the width direction of the absorbent article 50 is fixed near both ends of the skin side surface of the back sheet 30 (or near both ends of the non-skin side surface), a middle part in the width direction is fixed near both ends of the skin side surface of the top sheet 25, and the other end in the width direction forms a free end 40a that is not fixed to the top sheet 25. By providing an elastic stretchable member for the three-dimensional gathers (not shown) along the longitudinal direction near the free end 40a, the free end 40a of the three-dimensional gathers 40 is given an upstanding property, and can be deformed to fit the body shape of the wearer. Examples of fixing positions for one widthwise end of the three-dimensional gathers 40 include both widthwise ends of the non-skin side of the backsheet 30, both widthwise ends of a bag body in which the topsheet 25 and the backsheet 30 are partially or entirely joined, and both widthwise ends of the skin side of the topsheet 25.

As elastic members for three-dimensional gathers, for example, polyurethane threads, strip-shaped polyurethane films, thread-shaped or strip-shaped natural rubber, etc. are used, and as three-dimensional gather sheets, water-repellent or liquid-impermeable nonwoven fabrics formed from hydrophobic fibers, such as spunbond nonwoven fabrics, meltblown nonwoven fabrics, and three-layer laminated composite nonwoven fabrics of spunbond nonwoven fabrics/meltblown nonwoven fabrics/spunbond nonwoven fabrics, etc. are 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 1 between the top sheet 25 and the back sheet 30, a step of fixing the top sheet 25 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 25. 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.

The absorbent body 2 shown in FIG. 5 is a modified version of the absorbent body 1. The absorbent body 2 uses the same base nonwoven fabric 11, superabsorbent polymer 12, and hydrophilic sheet 20 as the absorbent body 1, and is configured such that the hydrophilic sheet 20 is stretched in the width direction and both end faces 20a, 20b in the width direction overlap on the top sheet 25 side of the base nonwoven fabric 11. Due to the presence of the overlapping parts of the hydrophilic sheet 20 (hereinafter also referred to as "overlapping areas"), the absorbent body 2 not only exhibits effects equal to or greater than those of the absorbent body 1, but also has the advantage of even higher diffusion and absorption rates of bodily fluids.

It is preferable that the width dimension of the overlapping region in the absorbent body 2 is 5% or more and 50% or less of the width dimension D of the absorbent body 2. If it is less than 5%, even if an overlapping region is provided, the effect of improving the diffusion rate and absorption rate of bodily fluids tends to be insufficient. Also, if it exceeds 50%, the diffusion rate and absorption rate of bodily fluids do not improve, while the hardness of the absorbent body increases, tending to worsen the fit.

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

The present invention will be described in detail below with reference to examples. Note that the present invention is not limited to the examples shown below.

Example 1
First, an air-through nonwoven fabric was prepared as a base nonwoven fabric (basis weight 30 g/ ^m2 , bending stiffness 0.018 gf- ^cm2 /cm, width dimension 60 mm, length dimension 400 mm), one side surface of the base nonwoven fabric was physically raised with a rotary saw blade (thickness after raising 1.2 mm, raising rate 25%), a highly absorbent polymer was dispersed (basis weight 400 g/ ^m2 ), and the polymer was fixed and supported between the fibers of the raised part of the base nonwoven fabric with a hot melt adhesive to obtain a highly absorbent sheet. Furthermore, an air-through nonwoven fabric (basis weight 35 g/ ^m2 , bending stiffness B 0.031 gf- ^cm2 /cm, width dimension 140 mm, length dimension 400 mm) was prepared as a hydrophilic sheet, and the raised surface side of the base nonwoven fabric was bonded to a hydrophilic sheet coated with a hot melt adhesive. Next, the hydrophilic sheet was folded inwards in thirds, and both ends of the hydrophilic sheet were overlapped above the non-raised surface of the base nonwoven fabric, and the overlapping areas were fixed with a hot melt adhesive. The entire raised surface, both widthwise end surfaces, and the entire non-raised surface of the base nonwoven fabric were covered with the hydrophilic sheet, thereby obtaining the absorbent body of Example 1.

Example 2
An absorbent body of Example 2 was produced in the same manner as in Example 1, except that an air-through nonwoven fabric having a basis weight of 25 g/m ² and a bending stiffness of 0.021 gf·cm ² /cm was used as the hydrophilic sheet.

Example 3
An absorbent body of Example 3 was produced in the same manner as in Example 1, except that an air-through nonwoven fabric having a basis weight of 70 g/m ² and a bending stiffness of 0.090 gf·cm ² /cm was used as the hydrophilic sheet.

Example 4
An absorbent body of Example 4 was produced in the same manner as in Example 1, except that an air-through nonwoven fabric having a basis weight of 100 g/m ² and a bending stiffness of 0.19 gf·cm ² /cm was used as the hydrophilic sheet.

Example 5
An absorbent body of Example 5 was produced in the same manner as in Example 1, except that a highly absorbent sheet obtained using an air-through nonwoven fabric having a width dimension of 90 mm was placed as the hydrophilic sheet, the hydrophilic sheet was folded inwards in three, and the raised surface, both widthwise end surfaces, and regions each 15 mm in the width direction from both end portions of the non-raised surface of the base nonwoven fabric were covered with the hydrophilic sheet and fixed with a hot melt adhesive. In this absorbent body, the non-raised surface of the base nonwoven fabric extending in the longitudinal direction with a width of 60 mm was exposed in the center in the width direction.

(Comparative Example 1)
An absorbent body of Comparative Example 1 was produced in the same manner as in Example 1, except that an air-through nonwoven fabric having a basis weight of 150 g/m ² and a bending stiffness of 0.67 gf·cm ² /cm was used as the hydrophilic sheet.

(Comparative Example 2)
An absorbent body was prepared in the same manner as in Example 1, except that an air-through nonwoven fabric having a basis weight of 35 g/ ^m2 and a bending rigidity of 0.031 gf· ^cm2 /cm was used as the base nonwoven fabric, and an air-through nonwoven fabric having a basis weight of 30 g/ ^m2 and a bending rigidity of 0.018 gf· ^cm2 /cm was used as the hydrophilic sheet, to prepare a sample of Comparative Example 2.

(Comparative Example 3)
An absorbent body of Comparative Example 2 was prepared in the same manner as in Example 1, except that an air-through nonwoven fabric having a basis weight of 150 g/ ^m2 and a bending rigidity B of 0.67 gf· ^cm2 /cm was used as the base nonwoven fabric, and a spunbond nonwoven fabric having a basis weight of 10 g/ ^m2 and a bending rigidity B of 0.005 ^gf ·cm2/cm was used as the hydrophilic sheet.

(Comparative Example 4)
An absorbent body of Comparative Example 4 was prepared in the same manner as in Example 1, except that a base nonwoven fabric and a hydrophilic sheet having a width of 60 mm were used and arranged without being folded.

(Comparative Example 5)
A laminated sheet (all dimensions in the width direction were ⁶⁰ mm) of air-through nonwoven fabric (basis weight 20 g/ ^m2 )/superabsorbent polymer (basis weight 280 g/ ^m2 )/air-through nonwoven fabric (basis weight 20 g/ ^m2 )/superabsorbent polymer (basis weight 100 g/ ^m2 )/spunlace nonwoven fabric (basis weight 20 g/m2) was used as the absorbent. The nonwoven fabric used in Comparative Example 5 was not subjected to a nap raising treatment like the base nonwoven fabric used in Example 1.

[Measurement item]
The thickness, absorption rate, and return amount of each absorbent material obtained in Examples 1 to 5 and Comparative Examples 1 to 5 were measured. The results are shown in Table 1.
(Thickness)
The thickness of the absorbent body at the center was measured under no load and under a load of 35 gf/cm ² .

(Absorption rate)
40 ml of 0.9% by mass saline (37°C) is poured into each of the absorbents of Example 1 and Comparative Examples 1 to 5 from a tube with an inner diameter of 30 mm under a pressure of 46 g/ ^cm2 , and the time (seconds) until the saline is absorbed into the absorbent surface is measured as the first absorption rate. After 3 minutes, 40 ml of 0.9% by mass saline (37°C) is poured again, and the time (seconds) until the saline is absorbed into the absorbent surface is measured as the second absorption rate. The smaller the value, the better the absorbency.

(Reverse flow amount)
200 ml of physiological saline was poured into the absorbent bodies of Example 1 and Comparative Examples 1 to 5, and 10 minutes after the pouring, filter paper was pressed against the surface of the absorbent body with a load of 35 gf/ ^cm2 , and the amount of water that returned to the filter paper in 1 minute was measured. The smaller the amount of return, the drier the absorbent body was.

(sensory evaluation)
With the cooperation of eight panelists who wear disposable diapers and regularly use wheelchairs, a sensory evaluation was conducted with a choice of "good" or "bad" for the wearing comfort (fit, softness) and absorbency (presence or absence of leakage outside the disposable diaper) when wearing tape-fastened disposable diapers using each of the absorbents of Example 1 and Comparative Examples 1 to 3. The wearers used the diapers for 8 hours and evaluated them during daily activities, and the results are shown in Table 1.
◎: When 8 people selected "good" 〇: When 6 to 7 people selected "good" △: When 3 to 5 people selected "good" ×: When 1 or 2 people selected "good" or when there is no person selected "good"

(Operational feasibility)
○: Normal production was possible without slowing down operations.
△: The operating speed was slower than normal by 1% to 10%.
×: The operating speed was reduced by more than 10% compared to normal.

The bending stiffness (bending stiffness) of each nonwoven fabric was measured by the following method.
(Bending strength)
The bending stiffness (bending rigidity) was measured by inserting a sample (100 mm x 100 mm) into the fixed chuck and movable chuck of a bending tester (product name: KES-FB2, manufactured by Kato Tech Co., Ltd.). The movable chuck moved to the maximum positive curvature of +2.5 cm ^-1 , reversed, passed through a curvature of 0, and then moved to the maximum negative curvature of -2.5 cm ^-1 , reversed, and ended at a curvature of 0, thus obtaining a reciprocating curve of the bending moment for one cycle of curvature. In the reciprocating curve of the bending moment, the average value of the slope between the curvatures of 0.5 cm ^-1 and 1.5 cm ^-1 and the slope between the curvatures of -0.5 cm ^-1 and -1.5 cm ^-1 was taken as the bending stiffness.

As can be seen from Table 1, the configuration of this embodiment makes it possible to obtain absorbent bodies and absorbent articles that have high levels of bodily fluid return, absorption speed, softness, fit, leakage, and operability.

Reference Signs List 1, 2 Absorbent body 10 Highly absorbent sheet 11 Base nonwoven fabric 11a Raised surface 11b Non-raised surface 11x Raised fiber 11X, 11Y Width direction end surface 12 Highly absorbent polymer 20 Hydrophilic sheet 20a, 20b Width direction both end surfaces of hydrophilic sheet 25 Top sheet 30 Back sheet 40 Three-dimensional gather 50 Absorbent article

Claims (4)

An absorbent article comprising a liquid-permeable top sheet, a liquid-impermeable back sheet, and an absorbent body disposed between the top sheet and the back sheet,
The absorbent body is
a base nonwoven fabric having a raised surface and a non-raised surface, the non-raised surface being disposed so as to face the top sheet;
a highly absorbent sheet comprising a highly absorbent polymer fixedly supported between the raised fibers on the raised surface of the base nonwoven fabric;
a hydrophilic sheet covering the raised surface of the base nonwoven fabric,
The hydrophilic sheet is
The first air-through nonwoven fabric has a bending stiffness of 0.02 gf cm ² /cm or more and 0.6 gf cm ² /cm or less,
The absorbent article has a three-dimensional shape in which both widthwise end faces of the hydrophilic sheet face each other between the top sheet and the base nonwoven fabric while being spaced apart from each other in the width direction , and are folded inward in three so as to cover both widthwise end faces of the base nonwoven fabric together with the raised surface of the base nonwoven fabric. The absorbent article according to claim 1 , wherein the first air-through nonwoven fabric has a basis weight of 20 g/m ² or more and 100 g/m ² or less. The absorbent article according to claim 1 or 2, wherein the base nonwoven fabric is a second air-through nonwoven fabric, the basis weight of the second air-through nonwoven fabric is 20 g/ ^m2 or more and 80 g/ ^m2 or less, and the thickness of the fibers constituting the second air-through nonwoven fabric is 1.6 dtex or more and 14 dtex or less. The absorbent article according to any one of claims 1 to 3 , wherein the basis weight of the superabsorbent polymer in the superabsorbent sheet is 200 g/ ^m2 or more and 1200 g/ ^m2 or less.