JP7454457B2 - absorbent articles - Google Patents

Description

The present invention relates to absorbent articles.

Recently, there is a demand for highly absorbent and large-capacity absorbent products due to the lack of manpower in nursing care settings. There are an increasing number of cases in which the number of replacements is being reduced. Conventionally, absorbent materials containing a large amount of fluff pulp and superabsorbent polymers have been used to increase the capacity of urine absorbing pads, but products with increased capacity in this way are thicker. Deterioration of the feeling of wearing and stuffiness are unavoidable. Some care recipients suffer from poor health such as lack of sleep and rough skin, so it is difficult to say that increasing the capacity of absorbent articles will simply reduce daily care. There is a need for an absorbent article that can reduce the burden of wearing it on care recipients with such constitutions.

From the perspective of making the absorbent body thinner, a super absorbent polymer (hereinafter also referred to as "SAP") is fixedly supported between two sheets of nonwoven fabric using a hot melt adhesive, and a super absorbent sheet containing no fluff pulp (hereinafter referred to as "SAP") is fixedly supported between two sheets of nonwoven fabric. (also referred to as "SAP Sheet") has been developed, and various proposals have been made.

Patent Document 1 discloses first and second nonwoven fabrics each having one surface coated with an adhesive, and stripes arranged in a longitudinal direction between the adhesive coated surfaces of the first and second nonwoven fabrics. a plurality of SAP layers, the adhesive is applied intermittently in the area facing the SAP layer on the adhesive-coated surface of the second nonwoven fabric, and the SAP layer is directly opposed on both sides of the SAP layer in the width direction without intervening the SAP layer. An SAP sheet is disclosed in which an adhesive is continuously applied in the longitudinal direction on each adhesive-applied surface of the first and second nonwoven fabrics.

Patent Document 2 discloses that an absorbent body disposed between a top sheet and a back sheet includes first and second absorbent bodies each including two sheets of nonwoven fabric and SAP particles disposed therebetween, A SAP sheet is disclosed in which the first and second absorbent bodies disposed on one side and the other side in the width direction have first and second folds extending in the longitudinal direction, respectively, and the first and second folds are opposed to each other. ing. Furthermore, Patent Document 2 further includes a third absorbent body including two nonwoven fabrics and SAP particles disposed between them, and the third absorbent body is an absorbent body disposed above the first and second absorbent bodies. A sexual article is disclosed.

Japanese Patent Application Publication No. 2006-158676 JP2013-42882A (Claim 1, Claim 5)

When using a superabsorbent sheet as the absorber for a large-capacity superabsorbent night pad, a configuration in which multiple layers of superabsorbent sheets are laminated in the thickness direction is considered to ensure a large amount of body fluid absorption. . In that case, the issue is the diffusion of bodily fluids from the superabsorbent sheet on the wearer's skin side layer (hereinafter also referred to as the "upper layer") to the superabsorbent sheet on the wearer's non-skin side layer (hereinafter also referred to as the "lower layer"). Become one. Especially when absorbing body fluids repeatedly and at intervals, superabsorbent sheets with a high proportion of superabsorbent polymers are generally unable to transfer body fluids to the lower layer properly due to reduced diffusivity after the upper layer swells, resulting in a lower absorption capacity as a whole. There is a lot of backlash while there is still some residual strength left, causing leakage and discomfort at an early stage. In a highly absorbent and thin absorbent body, the problem of the present invention is how to utilize the absorbing power of a plurality of highly absorbent sheets through repeated absorption.

Although Patent Document 1 and Patent Document 2 describe the superabsorbent sheet itself, they do not describe a structure or method for improving body fluid diffusivity or repeated absorbency when multiple superabsorbent sheets are laminated. do not have.

An object of the present invention is to provide an absorbent article that is comfortable to wear and includes a thin laminate of highly absorbent sheets as an absorbent body, which has excellent body fluid dispersibility and repeated absorbency, and is capable of absorbing a large amount of body fluid. It is.

As a result of extensive research in order to solve the above problems, the present inventor succeeded in obtaining a desired absorbent article and completed the present invention. The present invention relates to the following absorbent article.

(1) An absorbent article comprising a liquid-permeable top sheet, a liquid-impermeable back sheet, and an absorbent body disposed between them,
The absorber is
It has a 3-layer laminate in which 3 layers of superabsorbent sheets in which a superabsorbent polymer is firmly supported between 2 sheets of hydrophilic nonwoven fabric are stacked in the thickness direction,
The three-layer laminate is
A first layer of superabsorbent sheet located closest to the wearer's skin, a third layer of superabsorbent sheet located closest to the wearer's non-skin side, and a second layer located between these. including a super absorbent sheet;
The width direction dimension is the first layer superabsorbent sheet<the second layer superabsorbent sheet<the third layer superabsorbent sheet,
A widthwise dimension W1 of the hydrophilic nonwoven fabric on the skin side of the first layer superabsorbent sheet, a widthwise dimension W2 of the hydrophilic nonwoven fabric on the nonskin side of the first layer superabsorbent sheet, and The widthwise dimension W3 of the skin-side hydrophilic nonwoven fabric of the two-layer superabsorbent sheet is W1:W2=1.3:1.0 or more and 2.0:1.0 or less, and W1≦W3;
The superabsorbent sheet of the first layer firmly supports the superabsorbent polymer in a widthwise region of 80% or more and 100% of the W2,
The second layer superabsorbent sheet and the third layer superabsorbent sheet firmly support the superabsorbent polymer in a widthwise area of 80% or more and 100% of the respective widthwise dimensions,
In the first layer superabsorbent sheet and the second layer superabsorbent sheet, the hydrophilic nonwoven fabric on the skin side is wider than the hydrophilic nonwoven fabric on the non-skin side, and the hydrophilic nonwoven fabric on the non-skin side is wider than the hydrophilic nonwoven fabric on the non-skin side. The hydrophilic nonwoven fabric has a region extending outwardly from both edges in the width direction, the width direction dimension of the region is 10% to 20% of the W1, and the hydrophilic non-skin side of the region An absorbent article, wherein a raised surface having an apparent specific volume in an unloaded state of 35 cm ³ /g or more is formed on the surface facing the nonwoven fabric.
(2) Each of the skin side and non-skin side hydrophilic nonwoven fabrics of the first layer superabsorbent sheet and the second layer superabsorbent sheet each includes an air-through nonwoven fabric, and the third layer superabsorbent sheet Each of the skin-side and non-skin hydrophilic nonwoven fabrics of the absorbent sheet includes a pulp-containing nonwoven fabric comprising a spunbond nonwoven fabric and a pulp fiber web integrated into one surface of the spunbond nonwoven fabric. , the absorbent article according to (2) above.
(3) The absorbent article according to (1) or (2) above, wherein the napped surface has an apparent specific volume in an unloaded state of 35 cm ³ /g or more and 120 cm ³ /g or less.

According to the present invention, there is provided an absorbent article that includes a thin laminate of highly absorbent sheets as an absorbent body, which has excellent body fluid dispersibility and repeated absorbency, and is capable of absorbing a large amount of body fluid, and is comfortable to wear. .

1 is a plan view schematically showing the structure of an absorbent article according to a first embodiment of the present invention. 2 is a schematic cross-sectional view in the width direction taken along the line X ₁ -X ₁ shown in FIG. 1. FIG. FIG. 1 is a schematic plan view showing an enlarged configuration of a main part (absorbent body) of an absorbent article according to a first embodiment. FIG. 1 is a schematic perspective view showing an enlarged configuration of a main part (absorbent body) of an absorbent article according to a first embodiment. FIG. 2 is a schematic development diagram illustrating the structure of an absorber. FIG. 3 is a schematic development diagram illustrating the structure of the absorber in more detail.

In this specification, wearing an absorbent article refers to a state in which the absorbent article is worn on the body, regardless of whether before or after absorbing body fluids. In an absorbent article, the longitudinal direction is the direction indicated by Y in the figure, extending from the front and back of the wearer's crotch area when the absorbent article is worn on the body, and the width direction is the direction relative to the longitudinal direction. The thickness direction is the direction indicated by X in the figure, which is orthogonal to each other, and the thickness direction is the direction indicated by Z in the figure, in which each component is laminated. The skin side refers to the surface that contacts or faces the wearer's skin when the absorbent article is worn, and the non-skin side refers to the surface that contacts or faces the wearer's clothing. be. Body fluids refer to fluids discharged from the body, such as urine, blood, and water in loose stools.

<Absorbent article (first embodiment)>
The absorbent article 50 of this embodiment will be described below with reference to the drawings. 1 and 2 show an absorbent article 50 according to a first embodiment. 3 to 6 show the absorbent body 20. FIG. These drawings do not specify the shape, size, size relationship, etc. of each component in the absorbent article 50.

The absorbent article 50 of this embodiment can be used as a variety of absorbent articles regardless of whether it is for babies or adults, but typical examples include light incontinence pads, urine absorbing pads, pants-type disposable diapers, and tape-fastened disposable diapers. Can be mentioned. Various paper diapers as an outer and the absorbent article 50 as an inner may be combined. Both the lengthwise dimension and the widthwise dimension of the absorbent article 50 are not particularly limited, and are, for example, in the range of 100 mm or more and 800 mm or less, and in the range of 50 mm or more and 500 mm or less. By adjusting the dimensions of the absorbent article 50 within the above range, absorbent articles for various uses can be easily obtained.

As shown in FIG. 1, the absorbent article 50 includes a liquid-permeable top sheet 10 that is relatively close to the skin when worn, and is placed opposite the top sheet 10. A liquid-impermeable backsheet 30 that is relatively located on the non-skin side when wearing the top sheet 50, an absorbent body 20 disposed between the topsheet 10 and the backsheet 30, and the skin side of the topsheet 10. A pair of three-dimensional gathers 40 provided on the surface. The absorbent body 20 is sandwiched between the top sheet 10 and the back sheet 30, and body fluids such as urine are absorbed and retained in the absorbent body 20 through the top sheet 10. Depending on the use and type of the absorbent article 50, leg gathers, waist gathers, side flaps, etc. can be provided as appropriate.

As shown in FIGS. 3 to 6, the absorbent body 20 of this embodiment has two layers: a first-layer superabsorbent sheet 60 located closest to the wearer's skin, and a first-layer superabsorbent sheet 60 located closest to the wearer's skin. It is a 3-layer laminate consisting of a third layer of superabsorbent sheet 80 located at , and a second layer of superabsorbent sheet 70 located between them. , respectively, the hydrophilic nonwoven fabrics 63, 73, 83 on the skin side, the hydrophilic nonwoven fabrics 64, 74, 84 on the non-skin side disposed opposite thereto, and the superabsorbent polymer 12 interposed between these. layers 61, 71, and 81.
Second, the widthwise dimension of the hydrophilic nonwoven fabrics 63, 73, 83 on the skin side of each superabsorbent sheet 60, 70, 80 increases stepwise from the skin side to the non-skin side. The hydrophilic nonwoven fabrics 64, 74, and 84 also increase in size from the skin side toward the non-skin side, and have a predetermined width direction dimension relationship described later.
Thirdly, in the superabsorbent sheets 60, 70, the hydrophilic nonwoven fabrics 63, 73 on the skin side are wider than the hydrophilic nonwoven fabrics 64, 74 on the non-skin side. , a region extending outward in the width direction from both edges of the hydrophilic nonwoven fabrics 64, 74 on the non-skin side has a predetermined width dimension, and the area facing the hydrophilic nonwoven fabrics 64, 74 on the non-skin side has a predetermined width dimension. Raised surfaces 62a, 62b, 72a, 72b are formed on which a plurality of raised fibers 62x, 72x are erected.

According to the absorbent body 20, by configuring as described above, the bulky raised surfaces 62a, 62b, 72a, and 72b are provided in the first and second layer superabsorbent sheets 60 and 70, respectively. Therefore, the raised surfaces 62a, 62b, 72a, and 72b function as body fluid diffusion layers to spread the fluid from the first layer of superabsorbent sheet 60 to the second layer of superabsorbent sheet 70. A flow of body fluid occurs from the absorbent sheet 70 to the third layer superabsorbent sheet 80, and the body fluid diffusibility of the absorbent body 20 as a whole is significantly improved. Furthermore, since the absorbent body 20 has a three-layer laminated structure of superabsorbent sheets 60, 70, and 80, it has excellent absorbency for body fluids and is thin. Therefore, by using the absorbent body 20, a large amount of body fluid can be absorbed, the absorption rate is maintained at the high level at the beginning of use even during repeated absorption, wet back is prevented, and it is thin and has a good feeling of wearing and fit. , it is possible to obtain the absorbent article 50 of this embodiment, which can be suitably used as a large-capacity wide pad.

Hereinafter, each of the sheet-like constituent members will be explained in more detail in the order of the top sheet 10, the absorbent core 20, the back sheet 30, and the three-dimensional gathers 40. Note that these constituent members may have a three-dimensional structure other than sheet-like.

(Top sheet)
The top sheet 10 is a liquid-permeable sheet-like member that allows body fluids to quickly pass through toward the absorbent body 20, and is disposed opposite to the back sheet 30 with the absorbent body 20 in between. Since the top sheet 10 may come into contact with the wearer's skin, it is preferable to use a base material that is soft to the touch and does not irritate the skin. Examples of the base material include hydrophilic sheets, composite nonwoven fabrics that are laminates of the same or different types of hydrophilic sheets, open films such as open polyethylene films, and foamed films such as polyethylene foam and urethane foam. Hydrophilic sheets can be made using, for example, synthetic fibers made of synthetic resins such as polypropylene and polyethylene, recycled fibers such as rayon, natural fibers such as cotton, etc., using the air-through method, thermal bond method, spunlace method, spunbond method, etc. It can be obtained by processing using a known method.

From the viewpoint of improving liquid permeability, the top sheet 10 may be subjected to embossing or perforation on the surface according to a known method. In addition, from the viewpoint of reducing skin irritation, the top sheet 10 may contain one or more of a lotion, an antioxidant, an anti-inflammatory ingredient, a pH adjuster, an antibacterial agent, a moisturizer, etc. good.

From the viewpoints of strength, processability, and liquid return amount, the basis weight of the top sheet 10 is, for example, in the range of 15 g/m ² or more and 40 g/m ² or less. The shape of the top sheet 10 is not particularly limited, and may be any shape that covers part or all of the absorbent body 20 as required to guide body fluids to the absorbent body 20 to prevent leakage.

<Absorber>
The absorber 20 of this embodiment has a longitudinal dimension, for example, in a range of 100 mm or more and 800 mm or less, or in a range of 150 mm or more and 500 mm or less. Further, the widthwise dimension of the absorbent core 20 is, for example, in a range of 50 mm or more and 500 mm or less, or in a range of 60 mm or more and 400 mm or less. The entire surface or part of the absorbent body 20 may be embossed.
As shown in FIGS. 3 to 6, when the absorbent article 50 is worn on the body, the absorbent body 20 has a first layer superabsorbent sheet 60 located closest to the wearer's skin, and a first layer superabsorbent sheet 60 located closest to the wearer's skin. This is a three-layer laminate including a third layer of superabsorbent sheet 80 located on the non-skin side of the skin, and a second layer of superabsorbent sheet 70 located between them. The superabsorbent sheets 60, 70, and 80 are respectively located on the skin side (hereinafter simply referred to as "skin side") hydrophilic nonwoven fabrics 63, 73, and 83, and on the non-skin side opposite thereto. It includes hydrophilic nonwoven fabrics 64, 74, 84 (hereinafter simply referred to as "non-skin side") and adhesion support layers 61, 71, 81 of the superabsorbent polymer 12 interposed between them, and contains fluff pulp. It is a type of so-called superabsorbent sheet that does not contain

(Width dimension of super absorbent sheet)
The first layer, second layer, and third layer superabsorbent sheets 60, 70, and 80 each have a maximum width direction dimension of the first layer superabsorbent sheet 60<second layer superabsorbent sheet 70. <The relationship is that of the third layer of superabsorbent sheet 80. Here, the maximum width direction dimension is used because the width direction dimension of the hydrophilic nonwoven fabrics 63, 73, 83 on the skin side is different from the width direction dimension of each hydrophilic nonwoven fabric 64, 74, 84 on the non-skin side. Because there is. In a preferred embodiment, in the first, second, and third layer superabsorbent sheets 60, 70, and 80, the width direction dimensions of the skin-side hydrophilic nonwoven fabrics 63, 73, and 83 are the same as those of the hydrophilic nonwoven fabrics. 63<hydrophilic nonwoven fabric 73<hydrophilic nonwoven fabric 83, and the width direction dimensions of the hydrophilic nonwoven fabrics 64, 74, and 84 on the non-skin side are such that hydrophilic nonwoven fabric 64<hydrophilic nonwoven fabric 74<hydrophilic nonwoven fabric 84 They have the following relationship.

Further, as shown in FIGS. 5 and 6, the width direction dimension of the hydrophilic nonwoven fabric 63 on the skin side of the first layer superabsorbent sheet 60 is set as W1, and the width direction dimension of the hydrophilic nonwoven fabric 64 on the non-skin side is set as W1. When W2 is the width direction dimension of the second layer superabsorbent sheet 70, W1:W2=1.3:1.0 or more and 2.0:1.0 or less, and W1≦W3. have. Here, the widthwise dimension of the second-layer superabsorbent sheet 70 is W3, and in the second-layer superabsorbent sheet 70, the hydrophilic nonwoven fabric 73 on the skin side is larger than the hydrophilic nonwoven fabric 74 on the non-skin side. Since W3 is also wide, W3 may be replaced with the widthwise dimension of the skin-side hydrophilic nonwoven fabric 73 of the second layer superabsorbent sheet 70.

Due to the above-mentioned width dimension relationship, as shown in FIG. 6, in the first layer superabsorbent sheet 60, the width direction dimension W1 of the skin-side hydrophilic nonwoven fabric 63 is the width of the non-skin side hydrophilic nonwoven fabric 64. It is possible to provide the skin-side hydrophilic nonwoven fabric 63 with a region that is larger than the direction dimension W2 and extends outward in the width direction from both widthwise edges of the non-skin side hydrophilic nonwoven fabric 64, and the region Raised surfaces 62a and 62b, which will be described later, can be formed on the surface facing the hydrophilic nonwoven fabric 64 on the non-skin side. Similarly, in the second layer superabsorbent sheet 70, the widthwise dimension W3 of the hydrophilic nonwoven fabric 73 on the skin side is made larger than the widthwise dimension W4 of the hydrophilic nonwoven fabric 74 on the non-skin side. The non-woven fabric 73 can be provided with a region that extends outward in the width direction from both edges in the width direction of the hydrophilic non-woven fabric 74 on the non-skin side, and the area facing the hydrophilic non-woven fabric 74 on the non-skin side of the region can form raised surfaces 72a and 72b, which will be described later. In this way, by providing the first and second layer superabsorbent sheets 60 and 70 with the above-mentioned relationship in width direction, the raised surfaces 62a, 62b, and This makes it easy to form the raised surfaces 72a and 72b of the second-layer superabsorbent sheet 70 as a layer effective for body fluid diffusion.

Note that the widthwise dimension W5 of the skin-side and non-skin-side hydrophilic nonwoven fabrics 83 and 84 of the third layer superabsorbent sheet 80 may be the same. Furthermore, the longitudinal dimensions of the superabsorbent sheets 60, 70, and 80 are not particularly limited, but it is preferable that the superabsorbent sheet 60<superabsorbent sheet 70<superabsorbent sheet 80. As shown in FIG. 3, by configuring the skin side surfaces of the superabsorbent sheets 60, 70, and 80 to be exposed even partially to the top sheet 10, their respective functions can be exerted at the same time as body fluids are discharged. , it is possible to achieve both high levels of body fluid diffusivity and absorbency.

(Napped surface)
In the skin-side hydrophilic nonwoven fabric 63 of the first layer superabsorbent sheet 60, the widthwise dimension of the region extending outward in the widthwise direction from both widthwise edges of the non-skinside hydrophilic nonwoven fabric 64 is W1. It is 10% or more and 20% or less. Thereby, good and long-lasting body fluid diffusibility can be imparted to the entire absorber 20. When W1 is less than 10%, the area of the raised surfaces 62a and 62b becomes small, and there is a tendency that the desired body fluid diffusivity cannot be imparted to the absorbent body 20. When W1 exceeds 20%, the area of the fixed support layer 61 of the superabsorbent polymer 12 becomes relatively small, and the balance between body fluid diffusivity and body fluid absorbency tends to be lost. In addition, the widthwise dimensions of the regions of the skin-side hydrophilic nonwoven fabric 73 of the second layer superabsorbent sheet 70 that extend outward in the width direction from both widthwise edges of the non-skinside hydrophilic nonwoven fabric 74 are as follows: It is 10% or more and 20% or less of W3. The reason for setting the widthwise dimension of this region is the same as that for the first layer superabsorbent sheet 60.

In the skin-side hydrophilic nonwoven fabric 63 of the first-layer superabsorbent sheet 60, the non-skin areas on both sides in the width direction extend outward from both widthwise edges of the non-skin side hydrophilic nonwoven fabric 64, respectively. Raised surfaces 62a and 62b on which a plurality of raised fibers 62x are erected are formed on the surface facing the skin-side hydrophilic nonwoven fabric 64. Similarly, in the skin-side hydrophilic nonwoven fabric 73 of the second layer superabsorbent sheet 70, regions on both sides in the width direction extend outward from both widthwise edges of the non-skin side hydrophilic nonwoven fabric 74, respectively. Raised surfaces 72a and 72b on which a plurality of raised fibers 72x are erected are formed on the surface facing the hydrophilic nonwoven fabric 74 on the non-skin side. The raised surfaces 62a, 62b and the raised surfaces 72a, 72b have cushioning properties, and have the secondary effect of improving the feel and fit of the absorbent article 50.

From the viewpoint of realizing good body fluid diffusivity, the raised surfaces 62a, 62b and the raised surfaces 72a, 72b have an apparent specific volume in the unloaded state of 35 cm ³ /g or more, or 35 cm ³ /g or more and 120 cm ³ / It is set within the range below g. The apparent specific volume (SV) is a value obtained by dividing the thickness of each sheet of the region by the basis weight to obtain the volume cm ³ per unit gram. The specific volume is measured after maintaining an equilibrium state under the temperature and humidity conditions specified in JIS-P8111 (23±1° C., 50±2% RH). When the apparent specific volume in the unloaded state is less than 35 cm ³ /g, the body fluid diffusibility becomes insufficient, and the absorption rate during repeated absorption tends to decrease and wet back tends to occur. In addition, as a method for raising the raised surfaces 62a, 62b on the non-skin side surfaces of the hydrophilic nonwoven fabrics 63, 73, and both end regions in the width direction forming the raised surfaces 72a, 72b, a method using a rotary saw blade, a needle punch, etc. From the viewpoint of in-line productivity and cost, a method using a rotary saw blade is preferred.

(Hydrophilic nonwoven fabric)
In the first layer superabsorbent sheet 60 and the second layer superabsorbent sheet 70, the skin-side hydrophilic nonwoven fabrics 63, 73 and the non-skin side hydrophilic nonwoven fabrics 64, 74 are commonly used in this field. For example, thermal bond nonwoven fabrics, spunbond nonwoven fabrics, air-laid nonwoven fabrics, air-through nonwoven fabrics, pulp-containing nonwoven fabrics, etc. can be used. Among these, preferred implementations include forming raised surfaces 62a, 62b, and raised surfaces 72a, 72b on the hydrophilic nonwoven fabrics 63, 73 on the skin side, and from the viewpoint of permeability of body fluids from the skin side to the non-skin side. In this embodiment, the hydrophilic nonwoven fabrics 63, 64, 73, and 74 all include air-through nonwoven fabrics. The air-through nonwoven fabric has excellent body fluid permeability, and when the air-through nonwoven fabric is raised, the apparent specific volume in the unloaded state can be easily adjusted to 35 cm ³ /g or more. The basis weight of the air-through nonwoven fabric is in the range of 20 g/m ² or more and 80 g/m ² or less, and the thickness of the fibers that make up the air-through nonwoven fabric is in the range of 1.6 dtex or more and 14 dtex or less, or 1.8 dtex or more and 9.0 dtex or less. Or, it is in the range of 2.0 dtex or more and 6.0 dtex or less.

In the third layer superabsorbent sheet 80, as the skin-side hydrophilic nonwoven fabric 83 and the non-skin side hydrophilic nonwoven fabric 84, any material commonly used in this field can be used, such as thermal bond nonwoven fabric, Examples include spunbond nonwoven fabrics, airlaid nonwoven fabrics, air-through nonwoven fabrics, pulp-containing nonwoven fabrics, and the like. Among these, pulp-containing nonwoven fabrics are preferred from the viewpoint of temporary fluid retention properties and the like. When the skin side hydrophilic nonwoven fabric 83 and the non-skin side hydrophilic nonwoven fabric 84 are composed of pulp-containing nonwoven fabrics, the pulp-containing nonwoven fabric has good liquid retention properties, so even if a large amount of body fluid is discharged at once, Since the body fluid can be held inside until the body fluid is absorbed by the fixed support layer 61, 71, 81 of the superabsorbent polymer 12, wet back can be prevented.

(Pulp-containing nonwoven fabric)
The pulp-containing nonwoven fabric includes a nonwoven fabric and a pulp fiber web laminated on at least one surface of the nonwoven fabric (first embodiment of the pulp-containing nonwoven fabric). In this embodiment, for example, the pulp fiber web that contributes to body fluid dispersibility in the absorbent body 20 faces the raised surface 11a of the base nonwoven fabric 11, and the nonwoven fabric that contributes to, for example, imparting strength to the absorbent body 20 faces the outside. It is preferable that the pulp-containing nonwoven fabric is placed so as to face it.

A preferred pulp-containing nonwoven fabric includes a nonwoven fabric and a pulp fiber web integrated into at least one surface of the nonwoven fabric (a second embodiment of a pulp-containing nonwoven fabric). Here, "integration" means that at least before and after use of the absorbent article, the nonwoven fabric and the pulp fiber web are in a state where the nonwoven fabric and the pulp fiber web are not even partially separated and their functions are not significantly reduced. The basis weight of the nonwoven fabric is, for example, in the range of 7 g/m ² or more and 30 g/m ² or less, and the basis weight of the pulp fiber web is, for example, in the range of 30 g/m ² or more and 50 g/m ² or less. By setting the basis weights of the nonwoven fabric and the pulp fiber web within the above ranges, it becomes easy to adjust the basis weight of the pulp-containing nonwoven fabric to an appropriate range as described below.

Among the pulp-containing nonwoven fabrics, an integrated product formed by hydroentangling is preferable (third embodiment of pulp-containing nonwoven fabric). The integrated product is, for example, a pulp-containing nonwoven fabric in which pulp fibers are entangled with a water jet and integrated to provide a pulp fiber web on the surface of the nonwoven fabric without using a binder. In such a pulp-containing nonwoven fabric, the fibers constituting the nonwoven fabric and the pulp fibers are intertwined on one surface of the nonwoven fabric to form a pulp fiber web, and some of the pulp fibers penetrate through the nonwoven fabric in the thickness direction and form the other side. The nonwoven fabric and the pulp fiber web are extremely strongly bonded to each other (fourth embodiment of pulp-containing nonwoven fabric).

The pulp fibers used here are not particularly limited, but include, for example, bleached kraft pulp from softwoods such as radiata pine, slash pine, southern pine, lodgepole pine, spruce, and Douglas fir (hereinafter also referred to as "NBKP"). . NBKP can be used alone or in combination of two or more. The nonwoven fabric to be laminated on the pulp fiber web is not particularly limited, but from the viewpoint of the overall strength and liquid permeability of the pulp-containing nonwoven fabric, spunbond nonwoven fabrics made of synthetic resin fibers are preferred, and polypropylene fibers are preferred as the synthetic resin fibers. A spunbond nonwoven fabric containing fibers is more preferred, and a spunbond nonwoven fabric consisting of polypropylene fibers is even more preferred.

In the pulp-containing nonwoven fabric, the weight ratio of the nonwoven fabric to the pulp fiber web (nonwoven fabric/pulp fiber web) is, for example, in the range of 40/60% by weight or more and 10/90% by weight or less. When the content of the pulp fiber web is less than 60% by mass, the pulp-containing nonwoven fabric tends to have poor texture and sweat absorption and tends to become stuffy, and when it exceeds 90% by mass, the pulp-containing nonwoven fabric tends to become hard. The nonwoven fabric to be integrated with the pulp fiber web is not particularly limited, but from the viewpoint of support for the pulp fiber web, strength, softness, and texture of the entire pulp-containing nonwoven fabric, spunbond nonwoven fabric is preferable, and polypropylene fibers are preferred. A spunbond nonwoven fabric containing polypropylene fibers is more preferred, and a spunbond nonwoven fabric comprising polypropylene fibers is even more preferred.

The basis weight of the pulp-containing nonwoven fabric is, for example, in the range of 30 g/m ² to 80 g/m ² or in the range of 40 g/m ² to 60 g/m ² from the viewpoint of the thickness and strength of the product. If it is ^less than 30 g/m2, the pulp-containing non-woven fabric becomes too soft, resulting in a lower manufacturing yield and tends to tear easily after absorbing body fluids.If it exceeds 80 g/ ^m2 , the pulp-containing non-woven fabric becomes too hard and thick. , the absorber 20 becomes hard and tends to impair comfort when worn.

(Adhesive support layer of superabsorbent polymer)
The first-layer superabsorbent sheet 60 has a fixed support layer 61 of the superabsorbent polymer 12 in a widthwise region of 80% or more and 100% of the widthwise dimension W2 of the hydrophilic nonwoven fabric 64 on the non-skin side. , thereby achieving good body fluid absorption. In addition, the second layer superabsorbent sheet 70 and the third layer superabsorbent sheet 80 have their respective widthwise dimensions (more specifically, the widthwise dimensions of the hydrophilic nonwoven fabrics 74 and 84 on the non-skin side). The adhesive supporting layers 71 and 81 of the superabsorbent polymer 12 are provided in the width direction region of 80% or more and 100% of the width. This allows the second layer superabsorbent sheet 70 and the third layer superabsorbent sheet 80 to exhibit good body fluid absorbency. In any case, if the fixed support layers 61, 71, and 81 of the superabsorbent polymer 12 are formed in less than 80% of each of the above-mentioned widthwise regions, the absorbency of the absorbent body 20 tends to be insufficient.

(Super absorbent polymer)
The superabsorbent polymer 12 is not particularly limited as long as it can absorb urine and prevent backflow, such as polyacrylate, polyaspartate, (starch/acrylic acid) graft copolymer, ( Examples include acrylic acid/vinyl alcohol) copolymers, (isobutylene/maleic anhydride) copolymers, and saponified products thereof. Among these, from the viewpoint of absorption per weight, polyacrylates are preferred, and sodium polyacrylate is more preferred. The basis weight of the superabsorbent polymer 12 on the raised surface 11a of the superabsorbent sheet 10 (or the base nonwoven fabric 11) is, for example, in the range of 150 g/m ² or more and 800 g/m ² or less.

In addition, by avoiding the use of the finely powdered superabsorbent polymer 12 that has poor fluidity as a powder, the basic performance regarding absorption can be improved, and the absorbency caused by the hardness of the superabsorbent sheets 60, 70, and 80 can be improved. From the viewpoint of reducing the rough texture, it is preferable to use a particulate superabsorbent polymer 12 having a medium particle size as the superabsorbent polymer 12. The median particle diameter is, for example, in the range of 50 μm or more and 600 μm or less, or in the range of 100 μm or more and 500 μm or less.

The superabsorbent polymer 12 is firmly supported inside the superabsorbent sheets 60, 70, and 80 using a hot melt adhesive. In addition, from the viewpoint of not inhibiting the absorbency of the superabsorbent polymer 12 and not impairing the feel when worn, the content of the hot melt adhesive is, for example, in a range of 10 g/m ² or less. As hot melt adhesives, those having a melting point of 100°C or higher and 180°C or lower can be used without particular limitation.For example, synthetic rubber hot adhesives such as styrene-butadiene-styrene copolymers, styrene-isoprene-styrene copolymers, etc. Examples include melt adhesives and olefin hot melt adhesives such as ethylene-vinyl acetate copolymers. As a method for applying the hot melt adhesive, known methods such as a curtain coating 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 molten hot melt adhesive is applied in a contact manner can be used.

<Manufacturing method of absorber>
Although there is no particular restriction on the method for manufacturing the absorber 20, the following method may be mentioned as an example. A predetermined width on both widthwise sides of one surface of the hydrophilic nonwoven fabric 63 is raised along the longitudinal direction. A rotary saw blade or a needle punch is used for the raising to form raised surfaces 62a and 62b. The superabsorbent polymer 12 is fixed to the non-raised area in the planar direction between the raised surfaces 62a and 62b of the hydrophilic nonwoven fabric 63 using a hot melt adhesive, and at the same time, the hydrophilic nonwoven fabric 64 is attached to that surface to form the first layer. A superabsorbent sheet 60 is prepared. A second layer of superabsorbent sheet 70 is produced in the same manner. Next, the superabsorbent polymer 12 is fixedly supported between the skin-side and non-skin-side hydrophilic nonwoven fabrics 83 and 84 using a hot melt adhesive to produce a third layer superabsorbent sheet 80. By stacking these in a predetermined order, the absorbent body 20, which is a three-layer laminate, is obtained.

(back seat)
The backsheet 30 may be formed using a liquid-impermeable base material that prevents body fluids held by the absorbent body 20 from wetting clothing, and examples of the base material include, for example, a resin film, Examples include composite sheets that are laminates of resin films and nonwoven fabrics. The manufacturing method of the nonwoven fabric used in the composite sheet is not particularly limited, and examples thereof include spunbond nonwoven fabric, meltblown nonwoven fabric, composite nonwoven fabric that is a laminate of spunbond nonwoven fabric/meltblown nonwoven fabric, and spunbond nonwoven fabric/meltblown nonwoven fabric/spunbond nonwoven fabric. Examples include a composite nonwoven fabric that is a laminate, a composite material that is a laminate of two or more of these, and the like. Further, examples of the resin film include films of polyester, polyvinyl alcohol, polyethylene, polypropylene, etc., and composite films of polyethylene and polypropylene.

The basis weight of the back sheet 30 is, for example, in the range of 15 g/m ² or more and 40 g/m ^{2 or} less from the viewpoint of strength and workability. Further, from the viewpoint of preventing stuffiness when worn, the back sheet 30 is preferably breathable. To impart air permeability to the backsheet 30, for example, a method of adding a filler to a resin film, a method of embossing the backsheet 30 for perforation, etc. can be used. Here, the filler includes calcium carbonate, and the filler can be blended according to a known method.

(3D gathers)
As shown in FIG. 1, the absorbent article 50 is provided at both ends of the skin side of the top sheet 10 along the longitudinal direction of the absorbent article 50, for example, in order to prevent side leakage of bodily fluids excreted by the user. A pair of three-dimensional gathers 40 is provided nearby. In the three-dimensional gathers 40 of this embodiment, one end in the width direction is fixed near both ends of the skin side of the back sheet 30, a middle part in the width direction is fixed near both ends of the skin side of the top sheet 10, and the width thereof The other end 40a in the direction is a free end 40a that is not fixed to the top sheet 10. An elastic elastic member (not shown) is disposed near the free end 40a along the longitudinal direction, giving the free end 40a erectability and making it deformable to suit the body shape of the wearer.

The fixing position of one end in the width direction of the three-dimensional gathers 40 is not limited to this embodiment. For example, the position where the three-dimensional gathers 40 are fixed at one end in the width direction is not limited to the present embodiment. Examples include the vicinity of both ends in the width direction of the bag that is joined as a whole and stores the absorbent body 20 therein, and the vicinity of both ends in the width direction of the skin side of the top sheet 10. Note that the absorbent article 50 of this embodiment also includes an embodiment that does not include the three-dimensional gathers 40.

As the sheet member constituting the three-dimensional gathers 40, water-repellent and/or liquid-impermeable nonwoven fabrics made of hydrophobic fibers can be used without particular limitation.For example, spunbond nonwoven fabrics, melt-blown nonwoven fabrics, spunbond nonwoven fabrics/ Examples include composite nonwoven fabrics that are laminates of melt-blown nonwoven fabrics/spunbond nonwoven fabrics. As the elastic stretchable member, common products in this field can be used without particular limitation, and examples thereof include polyurethane thread, band-shaped polyurethane film, thread-shaped or band-shaped natural rubber, and the like.

<Method for manufacturing absorbent articles>
The absorbent article 50 can be manufactured by a known manufacturing method, but for example, a step of arranging the absorber 20 between the top sheet 10 and the back sheet 30, and a step of disposing the top sheet 10 and the back sheet 30 partially or completely. Manufacturing including a process of fixing using hot melt adhesive, heat embossing, ultrasonic embossing, high frequency embossing, etc. over the circumference, and a process of installing three-dimensional gathers 40 at predetermined positions of the back sheet 30 and top sheet 10. There are several methods. When the absorbent article 50 is a urine absorbing pad or a light incontinence pad, it may be individually wrapped in a package and then folded into three in the longitudinal direction. Further, leg gathers, waist gathers, side flaps, etc. can be provided as necessary.

Although the present invention has been described above using the embodiments, 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 embodiments. It will be obvious to those skilled in the art that modifications may be made. Furthermore, it is clear from the claims that forms with such changes or improvements may also be included within the technical scope of the present invention.

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

(Examples 1 and 2 and Comparative Examples 1 to 5)
An air-through nonwoven fabric (basis weight 25 g/m ² ) was used as the top sheet, and an absorbent body having the configuration shown in Tables 1 and 2 (the raised surface was physically raised with a rotary saw blade to a predetermined apparent specific volume (cm ^{3 )} . /g)), a breathable polyethylene sheet (basis weight 30 g/m ² ) was used as the liquid-impermeable backsheet, and a laminate of spunbond nonwoven fabric/meltblown nonwoven fabric/spunbond nonwoven fabric was used as the three-dimensional gather. Absorbent articles of Examples 1 and 2 and Comparative Examples 1 to 5 were produced using the composite nonwoven fabric (basis weight 15 g/m ² ), and the following evaluations were performed on these. The results are shown in Table 2.

[Evaluation of leakage at night by wearing a monitor]
At a certain facility, with the cooperation of eight panelists with relatively large amounts of urine, the pad-type disposable diapers obtained in Examples 1 to 2 and Comparative Examples 1 to 5 were worn, and the presence or absence of leakage after wearing them overnight was evaluated. We evaluated the following. The state of leakage, such as horizontal leakage, was observed and evaluated using the following criteria.
When 6 or more people and 8 or less people rated "No leaks", it is ``〇'', and when 3 or more people and 5 or less people rated ``No leaks'', it is ``△'', and ``No leaks'' is evaluated. When one or two people rated it as "no leakage", it was marked as "x".
At the same time, regarding the feeling of wearing the product, if a similar number of panelists rated the product as "less uncomfortable," it was given a rating of "○", "△", or "x".

[Absorption speed]
A pad-type disposable diaper was stretched out flat and fixed, and a cylindrical absorption speed jig with an inner diameter of 30 mm was installed at the center of the pad-type disposable diaper in the width and length directions on the skin-contacting side. 150 ml of 0.9% physiological saline was injected per diaper, and the time until the liquid level was absorbed by the surface of the paper diaper was measured. Three minutes after absorption, the next 150 ml was injected, 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 defined as the absorption rate (seconds). The measurement was carried out under a pressure of 35 g/cm ² using the weight of the absorption rate jig.

[Reverse amount]
The pad-type disposable diaper was stretched out flat and fixed in place, and 150 ml of 0.9% physiological saline was poured into the center of the skin side of the pad-type diaper in the width direction and length direction, 8 times at 3-minute intervals. After the water injection was completed, it was left standing for 10 minutes. A filter paper was placed at the center of the skin side of the pad type diaper in the width direction and length direction, and a weight with a load of 35 g/m2 was placed on top of the filter paper, and the filter paper was allowed to stand for 1 minute. After leaving it to stand for 1 minute, the weight was removed, and the weight of 0.9% physiological saline absorbed by the filter paper was determined from the difference in weight before and after absorption, and was determined as the amount of return (wet back, g).

10 Top sheet 12 Super absorbent sheet 20 Absorbent body 30 Back sheet 40 Three-dimensional gathers 50 Absorbent article 60, 70, 80 Super absorbent sheet 61, 71, 81 Adhesive support layer of super absorbent polymer 62a, 62b, 72a, 72b Raised surface 63, 64, 73, 74, 83, 84 Hydrophilic nonwoven fabric

Claims (3)

An absorbent article comprising a liquid-permeable top sheet, a liquid-impermeable back sheet, and an absorbent body disposed between them,
The absorber is
It has a 3-layer laminate in which 3 layers of superabsorbent sheets in which a superabsorbent polymer is firmly supported between 2 sheets of hydrophilic nonwoven fabric are stacked in the thickness direction,
The three-layer laminate is
A first layer of superabsorbent sheet located closest to the wearer's skin, a third layer of superabsorbent sheet located closest to the wearer's non-skin side, and a second layer located between these. including a super absorbent sheet;
The width direction dimension is the first layer superabsorbent sheet<the second layer superabsorbent sheet<the third layer superabsorbent sheet,
A widthwise dimension W1 of the hydrophilic nonwoven fabric on the skin side of the first layer superabsorbent sheet, a widthwise dimension W2 of the hydrophilic nonwoven fabric on the nonskin side of the first layer superabsorbent sheet, and The widthwise dimension W3 of the skin-side hydrophilic nonwoven fabric of the two-layer superabsorbent sheet is W1:W2=1.3:1.0 or more and 2.0:1.0 or less, and W1≦W3;
The superabsorbent sheet of the first layer firmly supports the superabsorbent polymer in a widthwise region of 80% or more and 100% of the W2,
The second layer superabsorbent sheet and the third layer superabsorbent sheet firmly support the superabsorbent polymer in a widthwise area of 80% or more and 100% of the respective widthwise dimensions,
In the first layer superabsorbent sheet and the second layer superabsorbent sheet, the hydrophilic nonwoven fabric on the skin side is wider than the hydrophilic nonwoven fabric on the non-skin side, and the hydrophilic nonwoven fabric on the non-skin side is wider than the hydrophilic nonwoven fabric on the non-skin side. The hydrophilic nonwoven fabric has a region extending outwardly from both edges in the width direction, the width direction dimension of the region is 10% to 20% of the W1, and the hydrophilic non-skin side of the region An absorbent article, wherein a raised surface having an apparent specific volume in an unloaded state of 35 cm ³ /g or more is formed on the surface facing the nonwoven fabric. Each of the skin side and non-skin side hydrophilic nonwoven fabrics of the first layer superabsorbent sheet and the second layer superabsorbent sheet each includes an air-through nonwoven fabric, and the third layer superabsorbent sheet Each of the skin-side and non-skin hydrophilic nonwoven fabrics comprises a pulp-containing nonwoven fabric comprised of a spunbond nonwoven fabric and a pulp fiber web integrated into one surface of the spunbond nonwoven fabric. 1. The absorbent article according to item 1. The absorbent article according to claim 1 or 2, wherein the raised surface has an apparent specific volume in an unloaded state of 35 cm ³ /g or more and 120 cm ³ /g or less.