JP2022131227A - Absorber and absorbent article - Google Patents

Abstract

To provide an absorbent article including a thin-type absorber having excellent fluid diffusibility. combining a high-level absorption performance, absorption rate and backflow prevention performance, at high level, and also having excellent wearing comfort and fittability.SOLUTION: An absorbent article 50 comprises a top sheet 10, a back sheet 30 and an absorber 20. The absorber 20 includes an absorbent sheet 25 without including absorbent fibers, and the absorbent sheet 25 is formed by superposing from a skin surface side of a wearer in an order of a polyurethane continuous porous body sheet 21, a perforated film 22 and a composite nonwoven fabric 23, The absorbent article further includes a first SAP layer between the polyurethane continuous porous body sheet 21 and the perforated film 22, and a second SAP layer between the perforated film 22 and the composite nonwoven fabric 23; and is formed by joining them so as to form a first block-like space 62 and a second block-like space 63 for including a high-absorbent polymer 12 between the polyurethane continuous porous body sheet 21 and the perforated film 22, and between the perforated film 22 and the composite nonwoven fabric 23, respectively.SELECTED DRAWING: Figure 2

Description

TECHNICAL FIELD The present invention relates to an absorbent body and an absorbent article comprising the absorbent body.

In general, absorbent articles are composed of a liquid-permeable top sheet, a liquid-impermeable back sheet, and an absorbent body disposed between them. absorbed and retained in In recent years, there has been a demand for thin absorbent articles that are not conspicuous when worn, and do not give a sense of discomfort when worn. When designing a thin absorbent article, it is usually considered to reduce the thickness of the absorbent body that occupies most of the absorbent article, and many absorbent articles using a thin absorbent body have been proposed (Patent Document 1 to 4).

In Patent Document 1, in an absorbent article in which a second sheet is arranged between a topsheet and an absorbent body, the absorbent body has a density higher than 0.12 g/cm ³ and the second sheet has a density of 1.5 × 10 Absorbent articles having a capillary force of ³ N or greater are disclosed. According to Patent Document 1, by optimizing the density of the absorbent body and the capillary force of the second seat, both the thinness of the absorbent body and the excellent absorption power are achieved at a high level, and the wearer can feel safe and comfortable when wearing the seat. It is described that a feeling of wearing can be given.

Patent Document 2 has a skin-side absorbent layer containing a nonwoven fabric and a superabsorbent polymer, and a non-skin-side absorbent layer containing a hydrophilic porous material and a superabsorbent polymer, and the non-skin-side absorbent layer is substantially An absorbent article is disclosed which is vertically elongated and has a smaller amount of superabsorbent polymer distributed in its widthwise central portion than in other portions. According to Patent Document 2, by using a hydrophilic porous material for the non-skin side absorbent layer and optimizing the distribution of the superabsorbent polymer, the thickness is thin while maintaining high liquid diffusibility and liquid retention. , the absorption rate can be increased.

Patent document 3 includes a laminate in which a substrate layer including a polyurethane foam layer as an absorbent gel material, a superabsorbent polymer layer, an adhesive layer, and a cover layer are laminated in this order, An absorbent body is disclosed in which the agent layer contains a hot-melt adhesive and the cover layer contains a nonwoven fabric (claims 1, 2, 4, paragraphs 0010 and 0016). Nonwoven fabric materials such as spunbond nonwoven fabrics, carded nonwoven fabrics, and air-laid nonwoven fabrics are only described as materials for the base layer and cover layer (Paragraph 0045). According to Patent Document 3, it is stated that the incorporation of a polyurethane foam layer that is stably attached onto the substrate layer provides a good fit and comfort, and maintains the utilization of the absorbent capacity of the absorbent. (Paragraph 0009, Paragraph 0043).

Patent Document 4 discloses a layered absorbent body comprising a plastic foam layer and/or a latex foam layer and a bodily fluid absorbing layer containing a particulate superabsorbent polymer, wherein the superabsorbent polymer comprises the plastic foam layer and/or or directly on, between, or under the latex foam layer, in a predetermined amount and/or in a predetermined location, and a foamed plastic layer and/or a foamed latex layer: the amount of superabsorbent polymer A layered absorbent body is disclosed in which the ratio is from 1:500 to 50:1, preferably from 1:50 to 25:1, most preferably from 1:5 to 10:1. According to Patent Literature 4, it is described that the use of the layered absorber described above enhances the absorption performance for water and aqueous liquids, especially the absorption performance under load.

JP 2016-67897 A JP 2009-131349 A JP 2014-140770 A Japanese Patent Publication No. 09-509909

All of the absorbent bodies described in Patent Documents 1 to 4 belong to thin absorbent sheets that do not contain absorbent fibers such as fluff pulp, and are effective in reducing the thickness and weight of absorbent articles. However, some sacrifice in absorption performance must be made. In particular, light incontinence products and incontinence pads having a narrow absorbent area cannot maintain sufficient absorption performance.

In absorbent articles, both the speed of absorption (hereinafter also referred to as "absorption rate") and the amount of backflow are important indicators of absorption performance. It is difficult to satisfy both requirements at a high level in thin absorbent articles.

An object of the present invention is to provide an absorbent article having a thin absorbent body which is excellent in body fluid diffusibility, has high levels of absorption performance, absorption speed, and anti-return property, and is excellent in wearability and fit. .

As a result of intensive research to solve the above problems, the present inventors have discovered a continuous porous polyurethane sheet, a perforated film, a composite nonwoven fabric obtained by laminating and integrating a pulp fiber web on a spunbond nonwoven fabric, and a high The inventors have found that a desired absorbent body and absorbent article can be obtained by forming a thin absorbent body (absorbent sheet) using an absorbent polymer, and have completed the present invention. That is, the present invention relates to the following absorbent articles.

(1) An absorbent article comprising a liquid-permeable topsheet, a liquid-impermeable backsheet, and an absorbent body provided therebetween,
The absorbent sheet is
From the wearer's skin side, at least a continuous porous polyurethane sheet, a porous film, and a composite nonwoven fabric in which a pulp fiber web is laminated and integrated on a spunbond nonwoven fabric are laminated in this order. having a superabsorbent polymer encapsulated therebetween;
Between the polyurethane continuous porous sheet and the perforated film, and between the perforated film and the composite nonwoven fabric, block-shaped spaces enclosing the superabsorbent polymer are formed respectively. An absorbent article characterized in that the absorbent article is joined as follows:
(2) The absorbent according to (1) above, wherein the polyurethane continuous porous sheet has a basis weight of 30 g/m ² or more and 300 g/m ² or less and an apparent density of 100 kg/m ³ or more and 200 kg/m ³ or less. sexual goods.
(3) The absorbent article according to (1) or (2) above, wherein the continuous porous polyurethane sheet has a hydrophilic skeleton surface.
(4) The perforated film has through holes penetrating from the skin side to the non-skin side, the diameter of the through holes is 0.3 mm or more and 1.5 mm or less, and the number of the through holes is 50. /cm ² or more, the absorbent article according to any one of the above (1) to (3).
(5) The absorption of (4) above, wherein the through-holes have different opening diameters on the skin side and the non-skin side, and the difference in opening diameter is 0.03 mm or more and 0.15 mm or less. sexual goods.
(6) The absorbent article according to (4) or (5) above, wherein the opening diameter of the through-hole on the skin side is larger than the opening diameter on the non-skin side.
(7) The strength required to stretch a 25 mm width test piece of the composite nonwoven fabric by 2 mm in the longitudinal direction in a Tensilon tensile test is 1.5 N / 25 mm or more and 5.0 N / 25 mm or less, above (1) to ( 5) Any absorbent article.
(8) The spunbond nonwoven fabric contains one or more fibers made of a resin material selected from the group consisting of nylon (trade name), vinylon, polyester, acrylic resin, polyethylene, polypropylene, and polystyrene. The absorbent article according to any one of (1) to (7).
(9) The composite type nonwoven fabric is a hydroentangled integrated product of the spunbond nonwoven fabric and the pulp fiber web, and the hydroentanglement is performed when the hole diameter Φ of the water jet nozzle for injecting the water jet is 0.06 mm or more. The absorbent article according to any one of (1) to (8) above, wherein the absorbent article is carried out under conditions of 15 mm or less and a water jet nozzle interval of 0.4 mm or more and 1.0 mm or less.
(10) The absorbent article according to any one of (1) to (9) above, wherein the composite nonwoven fabric has irregularities on the surface of the pulp fiber web in contact with the superabsorbent polymer.
(11) The absorbent according to any one of (1) to (10) above, wherein the basis weight of the superabsorbent polymer enclosed between the sheets is 30 g/m ² or more and 300 g/m ² or less. Goods.

According to the present invention, there is provided an absorbent article having a thin absorbent body which is excellent in body fluid diffusibility, has high levels of absorption performance, absorption rate, and anti-return property, and is excellent in wearability and fit.

1 is a plan view schematically showing the structure of an absorbent article according to this embodiment; FIG. FIG. 2 is a schematic cross-sectional view in the width direction along the X ₁ -X ₁ cutting line shown in FIG. 1; FIG. 2 is a longitudinal schematic sectional view taken along the Y ₁ -Y ₁ cutting line shown in FIG. 1; 1 is a schematic cross-sectional view showing the configuration of an absorbent sheet; FIG. FIG. 2 is a schematic cross-sectional view showing the flow of bodily fluids in the absorbent article shown in FIG. 1; 2 is a schematic cross-sectional view in the width direction showing the structure of an absorbent article according to Comparative Example 1. FIG. FIG. 10 is a schematic cross-sectional view in the width direction showing the configuration of absorbent articles according to Comparative Examples 2 and 3; FIG. 5 is a schematic cross-sectional view in the width direction showing the configuration of absorbent articles according to Comparative Examples 4 and 5. FIG. 10 is a schematic cross-sectional view in the width direction showing the configuration of an absorbent article according to Comparative Example 6. FIG. 10 is a schematic cross-sectional view in the width direction showing the configuration of an absorbent article according to Comparative Example 7. FIG.

In the present specification, wearing an absorbent article refers to a state in which the absorbent article is worn on the body regardless of whether body fluid is absorbed or not. In the absorbent article, the length direction is the direction across the front and back of the wearer's body through the crotch when the absorbent article is worn on the body, and the width direction is the direction orthogonal to the length direction. , and the thickness direction is the direction in which the constituent members are 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 liquids excreted from the body to the outside of the body, such as urine, blood, and water in loose stools.

<Absorbent article>
Hereinafter, an absorbent article 50 according to this embodiment will be described with reference to the drawings. 1-3 show an absorbent article 50. FIG. FIG. 4 shows an absorbent sheet precursor 25a. FIG. 5 shows a typical flow of bodily fluids through absorbent body 20 . 6 to 10 show absorbent articles 70, 71, 72, 73, 74, 75 and 76 according to Comparative Examples 1 to 7, respectively. These drawings do not define the shape, size, size relationship, etc. of each component in the absorbent article 50 .

The absorbent article 50 of the present embodiment can be used as various absorbent articles for infants, adults and the elderly, such as light incontinence products, light incontinence liners, incontinence pads, sanitary napkins and other pad products , pants-type disposable diapers, tape-fastening type disposable diapers, and the like. Among these, it can be suitably used as pad products such as light incontinence products and incontinence pads because it is thin and the absorption amount and absorption rate do not decrease even after multiple absorptions. Moreover, various paper diapers as outers may be combined with absorbent articles 50 as inners. Both the longitudinal dimension (maximum dimension) and the width dimension (maximum dimension) of the absorbent article 50 are not particularly limited, but are, for example, in the range of 100 mm or more and 800 mm or less and 50 mm or more and 500 mm or less. is. By adjusting the dimensions of the absorbent article 50 within the above range, various forms of absorbent articles can be easily obtained.

The absorbent article 50 shown in FIGS. 1 and 2 includes a liquid-permeable top sheet 10 positioned on the skin side and a liquid-impermeable back sheet 30 positioned opposite the top sheet 10 and positioned on the non-skin side. , an absorbent body 20 arranged between the top sheet 10 and the back sheet 30, and a pair of three-dimensional gathers 40 provided on the skin side surface of the top sheet 10. - 特許庁

The absorbent body 20 includes an absorbent sheet 25 that does not contain absorbent fibers such as fluff pulp, and as shown in FIG. and a composite nonwoven fabric 23 in which a pulp fiber web 26 is laminated and integrated on a spunbond nonwoven fabric 27 are laminated in this order. It has a first SAP layer encapsulating polymer 12 (FIG. 4) and a second SAP layer encapsulating superabsorbent polymer 12 between sheets of perforated film 22 and composite nonwoven fabric 23. The layer is divided into block-shaped spaces 62 in the plane direction, and band-shaped first joints 60 in plan view are provided vertically and horizontally to partially join the continuous porous polyurethane sheet 21 and the perforated film 22, and the second SAP layer The layer is divided into block-shaped spaces 63 in the plane direction, and strip-shaped second joining portions 61 in plan view for partially joining the perforated film 22 and the composite nonwoven fabric 23 are provided vertically and horizontally.

According to this embodiment, each layer of the continuous porous polyurethane sheet 21, the perforated film 22, and the composite nonwoven fabric 23, which are arranged in order from the wearer's skin side, is block-shaped and contains the superabsorbent polymer 12. By providing the absorbent sheets 25 that are partially joined to form the spaces 62 and 63, the absorption rate does not decrease particularly during repeated absorption, the reversion is small, and the absorption is excellent in the diffusion of body fluids. It is possible to obtain an absorbent body 20 having excellent properties and wearing comfort and an absorbent article 50 having the absorbent body 20 . Since the continuous porous polyurethane sheet 21 is highly flexible, it is difficult to feel the hardness of the superabsorbent polymer 12 before absorbing body fluids. The uneven surface of 26 is in contact with the superabsorbent polymer 12, and the superabsorbent polymer 12 is enclosed and arranged in the block-like space 63, thereby suppressing displacement and movement of the superabsorbent polymer 12. , the thickness and texture can be kept more uniform in the longitudinal and width directions even after absorbing bodily fluids, so that the feeling of wearing is improved.

The absorbent article 50 of this embodiment has the top sheet 10, the absorbent body 20, and the back sheet 30 as basic structural units. Various known modifications such as disposing a liquid-permeable transfer sheet (not shown) or a liquid-permeable second sheet between 10 and absorbent body 20 can be applied. Hereinafter, the constituent members of the absorbent article 50 will be described in more detail in the order of the top sheet 10, the absorbent body 20, the back sheet 30, and the three-dimensional gathers 40. FIG.

<Top sheet>
The top sheet 10 is a liquid-permeable sheet-like base material that allows bodily fluids to pass quickly toward the absorbent body 20 . The topsheet 10 is preferably a base material that is soft to the touch and non-irritating to the wearer's skin so that it may contact the wearer's skin. Examples of the substrate include a hydrophilic sheet, a composite nonwoven fabric which is a laminate of hydrophilic sheets of the same or different types, an open film such as an open polyethylene film, and a foamed film such as a polyethylene foam and a urethane foam. Hydrophilic sheets include, for example, synthetic fibers made of synthetic resins such as polypropylene and polyethylene, regenerated fibers such as rayon, and natural fibers such as cotton. A spunbond nonwoven fabric etc. are mentioned. Among these, nonwoven fabrics are preferred, and air-through nonwoven fabrics, thermal bonded nonwoven fabrics, spunbond nonwoven fabrics and the like are more preferred.

The surface of the top sheet 10 may be embossed or perforated from the viewpoint of improving liquid permeability. From the viewpoint of reducing irritation to the skin, the top sheet 10 may contain one or more of lotions, antioxidants, anti-inflammatory ingredients, pH adjusters, antibacterial agents, moisturizers, and the like. The basis weight of the top sheet 10 is, for example, in the range of 18 g/m ² or more and 400 g/m ² or less from the viewpoint of strength, processability, and liquid return amount. The shape of the top sheet 10 is not particularly limited as long as it covers part or all of the absorbent body 20, which is necessary for guiding bodily fluids to the absorbent body 20 without leakage.

<Absorber>
The absorber 20 has a longitudinal dimension (maximum length) of, for example, 100 mm or more and 800 mm or less, 150 mm or more and 500 mm or less, or 270 mm or more and 500 mm or less. The widthwise dimension (maximum width) of the absorbent body 20 is, for example, in the range of 50 mm or more and 500 mm or less, 60 mm or more and 400 mm or less, or 70 mm or more and 105 mm or less. In addition, when the absorber 20 has an hourglass shape in plan view, the longitudinal dimension is in the range of 180 mm or more and 800 mm or less, and the width dimension of the abdominal part and the dorsal part that contact the abdomen and the back of the wearer, respectively. Both are in the range of 60 mm or more and 400 mm or less, and the width direction dimension of the crotch portion that contacts the wearer's crotch portion is in the range of 90 mm or more and 250 mm or less. All or part of the absorbent body 20 may be embossed. Examples of the planar shape of the absorber 20 include an hourglass shape, an I shape, a rectangle, a square with rounded corners, and an ellipse.

The absorbent body 20 of this embodiment includes an absorbent sheet 25 that does not contain absorbent fibers such as fluff pulp, and a hydrophilic sheet 24 that wraps the absorbent sheet 25 . The absorbent sheet 25 will be detailed later. For the hydrophilic sheet 24, for example, the non-skin side of the absorbent sheet 25 is placed near the central portion in the width direction, and after these are adhered as necessary, both sides in the width direction of the hydrophilic sheet 24 are absorbed by C-folding. The absorbent sheet 25 is superposed on the skin side, and if necessary, the superposed portions are adhered to wrap the absorbent sheet 25 as a whole. The hydrophilic sheet 24 not only wraps the entire absorbent sheet 25 as described above, but also covers the non-skin side surface of the absorbent sheet 25, both width direction side surfaces, and the vicinity of both width direction end portions of the skin side surface. Between 10 and the absorbent sheet 25, the absorbent sheet 25 may be wrapped so that both ends in the width direction of the hydrophilic sheet 24 are opposed to each other and spaced apart to form a slit-like space extending in the longitudinal direction.

(hydrophilic sheet)
As the hydrophilic sheet 24, any one commonly used in this field can be used. etc. Among hydrophilic nonwoven fabrics, hydrophilic nonwoven fabrics such as thermal bonded nonwoven fabrics, spunbond nonwoven fabrics, air-through nonwoven fabrics, and pulp-containing nonwoven fabrics are more preferred, and air-through nonwoven fabrics, pulp-containing nonwoven fabrics, spunbond nonwoven fabrics, and the like are more preferred. The hydrophilic sheet 24 has a thickness of, for example, 0.10 mm or more and 0.25 mm or less, and a basis weight of, for example, 5 g/m ² or more and 40 g/m ² or less. Each member constituting the absorbent sheet will be described below.

(polyurethane continuous porous sheet)
The polyurethane continuous porous sheet 21 contains polyurethane open-cell foam (hereinafter also referred to as “flexible polyurethane foam”) as a main component, and is excellent in body fluid diffusibility and flexibility. Here, "containing as a main component" means containing 50% by mass or more of the entire flexible polyurethane foam. For the continuous porous polyurethane sheet 21, for example, a single-layer sheet containing flexible polyurethane foam as a main component, a single-layer sheet made of flexible polyurethane foam, or the like can be used.

The polyurethane continuous porous sheet 21, for example, evenly diffuses the body fluid that has permeated the top sheet 10 over the entire absorbent body 20 (absorbent sheet 25). The continuous porous polyurethane sheet 21 also has flexibility, and before absorbing the body fluid, it relieves the rough feeling of the particles of the superabsorbent polymer 12, and after absorbing the body fluid, the superabsorbent polymer 12 swells to create a jelly-like pressure. The feeling of wearing the absorbent article 50 is greatly improved because the absorbent article 50 absorbs bodily fluids, swells, and hardens, thereby reducing the feeling of ruggedness.

Flexible polyurethane foams can be obtained, for example, by mixing raw material compounds such as polyols and polyisocyanates, additives such as foaming agents, foam stabilizers and catalysts, and heating and foaming the resulting mixture. Alternatively, a gaseous foaming agent may be injected while the raw material compounds are reacted under heating. The expansion ratio, apparent density, tensile strength, Each property such as tensile elongation at break, elongation stress, mean friction coefficient (MIU), friction coefficient variation (MMD) can be adjusted. For example, the foaming ratio of the flexible polyurethane foam is in the range of 10 times or more and 60 times or less from the viewpoint of body fluid diffusibility, flexibility, and the like. Flexible polyurethane foam can also be produced according to an extraction method, a W/O emulsion method, or the like.

The grammage and apparent density of the continuous porous polyurethane sheet 21 are, for example, 30 g/m ² or more, respectively, from the viewpoints of body fluid diffusibility and flexibility, prevention of liquid backflow and body fluid leakage, breathability, and stuffiness. The apparent density is selected from the range of 300 g/m ² or less, or the range of 50 g/m ² or more and 250 g/m ² or less. , flexibility, etc., it is selected from the range of 100 kg/m ³ or more and 200 kg/m ³ or less, or the range of 120 g/m ² or more and 180 g/m ² or less.

The thickness of the continuous porous polyurethane sheet 21 is, for example, in the range of 1.0 mm or more and 4.0 mm or less, or in the range of 1.5 mm or more and 3.2 mm or less. The thickness is measured under no-load conditions using, for example, a "height gauge" (manufactured by Mitutoyo Co., Ltd.).

The skeletal surface of the flexible polyurethane foam contained in the continuous porous polyurethane sheet 21 may be hydrophilic or hydrophobic, but in a preferred embodiment, the skeletal surface is hydrophilic from the viewpoint of wettability with body fluids. In addition, examples of the skeleton having hydrophilicity include those containing a polyol and a polyalkylene oxide polyol. Moreover, it may be hydrophilized by introducing a hydrophilic group derived from a surfactant, ethylene oxide, or the like into the hydrophobic skeleton. Whether or not the surface of the skeleton is hydrophilic is determined by first placing a sample of 10 mm or more in width and 10 mm or more in length cut out from the continuous porous polyurethane sheet 21 on a flat surface so as not to bend, and then , 10 drops of ion-exchanged water (0.05 mL) are dropped on the sample, and the time until the sample is absorbed is measured. It is judged to be hydrophilic if

(Perforated film)
As shown in FIGS. 2 to 4, the perforated film 22 exhibits liquid permeability by having a plurality of perforations 22a penetrating from one surface to the other surface. The perforated film 22 consists of a polyurethane continuous porous sheet 21, which is a skin-side sheet (hereinafter also referred to as "skin-side material") located on the skin side in the absorbent sheet 25, and a non-skin-side sheet located on the non-skin side. (hereinafter also referred to as “non-skin side material”) and the composite nonwoven fabric 23 (hereinafter also referred to as “intermediate material”). The fixed support layer of the absorbent polymer 12 is divided in the thickness direction into a first SAP layer (skin-side SAP layer) and a second SAP layer (non-skin-side SAP layer), and between the first SAP layer and the second SAP layer are arranged so that they are permeable to body fluids.

As shown in FIG. 5, the bodily fluid excreted onto the absorbent body 20 (or absorbent sheet 25) receives the resistance of the perforated film 22 and once spreads in the plane direction (especially in the longitudinal direction) of the first SAP layer, Almost at the same time, it also flows into the second SAP layer through the plurality of pores 22a of the perforated film 22, so that the body fluid diffusibility of the first SAP layer and the second SAP layer, particularly in the longitudinal direction, can be enhanced. At the same time, the perforated film 22 prevents, for example, gel blocking, in which the superabsorbent polymer 12 that has absorbed bodily fluids swells and binds together, from occurring over a wide area and reducing the absorption speed, absorption amount, and the like. As a result, even after absorbing body fluids a plurality of times, the rate of absorption of body fluids is very small, and body fluids can be absorbed while preventing leakage.

As described above, the perforated film 22 has a plurality of perforations (through holes) 22a penetrating from the skin side to the non-skin side and opening to both surfaces. The number of pores 22a in the perforated film 22 is, for example, 50/cm ² or more, and the upper limit depends on the aperture diameter of the pores 22a. A range in which the effect of diffusing body fluid from the first SAP layer to the second SAP layer by the openings 22a can be obtained at a high level in a well-balanced manner may be appropriately selected. Moreover, from the viewpoint of permeability to body fluids, etc., the open area ratio is in the range of 25% or more and 50% or less, or in the range of 30% or more and 50% or less. The aperture 22a has, for example, a funnel-shaped three-dimensional shape in which the aperture diameter on one surface is larger than the aperture diameter on the other surface. The perforated film 22 of this embodiment is arranged such that the perforation diameter on the skin side is larger than the perforation diameter on the non-skin side, or the perforation diameter on the non-skin side is greater than the perforation diameter on the skin side. , the arrangement improves the diffusion of body fluids from the first SAP layer to the second SAP layer, and improves the diffusion of body fluids of the absorbent sheet 25 as a whole. Among the above-described two arrangements, the arrangement in which the opening diameter on the skin side is larger than the opening diameter on the non-skin side is preferable from the viewpoint of body fluid diffusibility.

In the perforated film 22, the perforation diameters on the skin side and the non-skin side are selected from a range of, for example, 0.3 mm or more and 1.5 mm or less. If the pore diameter is less than 0.3 mm, there is a tendency for the body fluid permeability from the first SAP layer to the second SAP layer to decrease. If the pore diameter exceeds 1.5 mm, body fluids are too easily permeable, and there is a tendency that a flow in the surface direction, particularly in the longitudinal direction, of the first SAP layer cannot be formed. In a preferred embodiment, the perforated film 22 has a perforation diameter on the skin side that is greater than the perforation diameter on the non-skin side by 0.03 mm or more and 0.15 mm or less. By setting the difference between the pore diameter of the skin side and the pore diameter of the non-skin side to the range described above, the perforated film 22 allows the body fluid to flow in the surface direction in the first SAP layer and the body fluid to flow into the second SAP layer. diffusion of the absorbent sheet 25 as a whole is improved.

The basis weight of the perforated film 22 is, for example, in the range of 10 g/m ² or more and 100 g/m ² or less from the viewpoint of preventing the absorbent article 50 from feeling hard and deteriorating the wearing feeling. As the perforated film 22, a plastic film having funnel-shaped through holes can be used without particular limitation, and examples thereof include a perforated polyethylene film and a perforated polypropylene film.

(Composite nonwoven fabric)
The composite nonwoven fabric 23 is a nonwoven fabric obtained by laminating or laminating a pulp fiber web 26 on the surface of a spunbond nonwoven fabric 27 (FIGS. 2 to 4). Here, "integration" means a state in which the spunbond nonwoven fabric 27 and the pulp fiber web 26 are not separated even partially during the period of use of the absorbent article 50, and the function of the composite nonwoven fabric 23 is not greatly reduced. It means that there is The composite nonwoven fabric 23 of the present embodiment, for example, as shown in FIG. The pulp fiber web 26 of the composite nonwoven fabric 23, which is the side material, is arranged so as to face it. By arranging in this way, the functions of the pulp fiber web 26, which will be described later, can be fully exhibited, and the desired absorbent body 20 can be obtained.

The composite nonwoven fabric 23 can be produced by various methods. For example, according to the hydroentangling method, the composite nonwoven fabric 23 can be produced by jetting pulp fibers together with a water jet to a spunbond nonwoven fabric. In the hydroentanglement method, the hole diameter Φ of the water jet nozzle that injects the water jet is, for example, in the range of 0.06 mm or more and 0.15 mm or less, and the water jet nozzle is in the range of, for example, 0.4 mm or more and 1.0 mm or less.

The composite nonwoven fabric 23, which is an integrated product formed by hydroentanglement, is integrated with the pulp fiber web 26 by entangling the fibers forming the spunbond nonwoven fabric 27 with the pulp fibers on one surface of the spunbond nonwoven fabric 27. Part of the pulp fibers penetrates the spunbond nonwoven fabric 27 in the thickness direction and is exposed on the other surface, so that the spunbond nonwoven fabric 27 and the pulp fiber web 26 are firmly fixed. The composite nonwoven fabric 23 produced by the hydroentangling method has fine irregularities (not shown) formed on the surface of the pulp fiber web 26 . Therefore, when the perforated film 22 and the pulp fiber web 26 of the composite nonwoven fabric 23 are arranged so as to face each other, the position of the powdered superabsorbent polymer 12 is fixed by the minute unevenness of the pulp fiber web 26. There is an advantage that displacement of the superabsorbent polymer 12 due to movements of the wearer and accompanying deterioration of absorption performance and deterioration of wearing comfort are prevented. In addition, since the pulp fiber web 26 has a function of temporarily storing body fluid, even if a large amount of body fluid is temporarily discharged, the amount of wetback can be reduced.

In a preferred embodiment, the composite nonwoven fabric 23 has a tensile strength (hereinafter also referred to as “tensile strength in Tensilon test”) necessary for stretching a test piece formed with a width of 25 mm by 2 mm in the longitudinal direction in a tensile test with Tensilon. , from 1.5 N/25 mm to 5.0 N/25 mm. As a result, the shape retention of the absorbent body 20 and the feeling of wearing when the absorbent article 50 is worn can be achieved at a high level.

In another preferred embodiment, the mass composition ratio of the spunbond nonwoven fabric 27 and the pulp fiber web 26 in the composite nonwoven fabric 23 (spunbond nonwoven fabric 27/pulp fiber web 26, mass % basis) is 35/65 or more and 10/ 90 or less, or 40/60 or more and 25/75 or less. When the mass composition ratio is within the range described above, the effect of maintaining the shape of the pulp fiber web 26 by the spunbond nonwoven fabric 27 is maintained, and not only the effect of preventing the positional displacement of the superabsorbent polymer 12 by the pulp fiber web 26 but also the pulp fiber web 26 The temporary retention of bodily fluids by the absorbent article 50 is sufficiently exhibited, and wetback and leakage of bodily fluids at the initial stage of bodily fluid discharge are sufficiently prevented, and the composite nonwoven fabric 23 maintains a predetermined softness. Good wearing feeling and touch can be imparted.

Here, as the spunbond nonwoven fabric 27, those manufactured by a spunbond method, a meltblowing method, a flash spinning method, or the like can be used without particular limitation. A spunbonded nonwoven fabric containing one or more resin fibers made of a resin material such as polypropylene, polystyrene, etc. Further, the spunbonded nonwoven fabric 27 is hydrophilized with a known hydrophilic agent such as a surfactant. The hydrophilic treatment makes it easier for bodily fluids to pass through the spunbond nonwoven fabric 27 and reach the pulp fiber web 26 .

The basis weight of the spunbond nonwoven fabric 27 is, for example, in the range of 7 g/m ² or more and 20 g/m ² or less, or in the range of 10 g/m ² or more and 17 g/m ² or less. The basis weight of the pulp fiber web 26 is, for example, in the range of 30 g/m ² to 70 g/m ² or in the range of 30 g/m ² to 50 g/m ² . By setting the basis weights of the spunbond nonwoven fabric 27 and the pulp fiber web 26 within the ranges described above, it becomes easier to adjust the basis weight of the composite nonwoven fabric 23 to an appropriate range.

The pulp fibers contained in the pulp fiber web 26 are not particularly limited, but include bleached softwood kraft pulp (NBKP) such as radiata pine, slash pine, southern pine, lodgepole pine, spruce, and Douglas fir. NBKP can be used individually by 1 type or in combination of 2 or more types.

<Block space>
In this embodiment, the superabsorbent polymer 12 is enclosed between the polyurethane continuous porous sheet 21 and the perforated film 22 to form the first SAP layer, and the first SAP layer has a plurality of A first block-shaped space (closed space) 62 is formed. A second SAP layer is formed by enclosing the superabsorbent polymer 12 between the perforated film 22 and the composite nonwoven fabric 23, and a plurality of second block-like structures are formed on the second SAP layer by the second joints 61. A space (closed space) 63 is formed.

In the first SAP layer and the second SAP layer, each layer is divided into a plurality of block-shaped spaces 62 and 63 in the plane direction, and a plane that partially joins the polyurethane continuous porous sheet 21 and the perforated film 22 is provided. A first joint portion 60 and a second joint portion 61 in the form of a band of sight are provided in a straight line with a predetermined interval in the vertical and horizontal directions. The first SAP layer and the second SAP layer of the present embodiment are separated from the outer edge of the absorbent article 50 by a predetermined distance and extend substantially parallel to the outer edge in the longitudinal direction and the width direction of the absorbent article 50 . A rectangular closed space having a substantially similar shape is formed, and a plurality of first joint portions 60 and second joint portions 61 extend in the width direction substantially parallel and at substantially equal intervals in the closed space. A plurality of first SAP layers and a plurality of second SAP layers are respectively formed in parallel in the longitudinal direction, coupled to a first joint portion 60 and a second joint portion 61 forming the outer frame of the closed space. Note that the first joint portion 60 and the second joint portion 61 may be provided along the outer edge of the absorbent article 50 .

In a plurality of first block-shaped (or rectangular) spaces 62 and second block-shaped (or rectangular) spaces 63 separated by the first joints 60 and the second joints 61, respectively, Each encapsulates a predetermined amount of superabsorbent polymer 12 . The amount of the superabsorbent polymer 12 enclosed in the first block-shaped space 62 and the second block-shaped space 63 may be the same or different, but the basis weight of the superabsorbent polymer 12 is, for example, 30 g. /m ² or more and 300 g/m ² or less. As a result, the superabsorbent polymer 12 swollen by absorption of body fluid binds over a wide area, preventing the occurrence of gel blocking that hinders the diffusion of body fluid. The decrease in absorption performance of is remarkably reduced.

The planar view shape of the first block-shaped space 62 and the second block-shaped space 63 provided in the first SAP layer and the second SAP layer is substantially rectangular in this embodiment, but is not limited thereto. Various shapes such as triangles (especially equilateral triangles), hexagons (especially regular hexagons), circles, and concentric circles are possible. The width dimension, the number and arrangement of the first joints 60 in the longitudinal direction and the width direction are appropriately selected according to the amount of the superabsorbent polymer 12 enclosed in the block-shaped space 61 . The first joint 60 and the second joint 61 may comprise, for example, a hot melt adhesive, or may be welded areas by heat sealing, ultrasonic sealing, or the like.

In a preferred embodiment, the number of block-shaped spaces 63 formed in the second SAP layer is greater than the number of block-shaped spaces 62 formed in the first SAP layer. According to this configuration, body fluid diffusion to the entire absorbent sheet 25 or absorbent body 20 is further improved, and gel blocking is prevented, while maintaining the absorption speed at the initial setting and further increasing the absorption amount. can be done.

(super absorbent polymer)
The superabsorbent polymer 12 is not particularly limited as long as it can absorb bodily fluids and prevent backflow. Polyacrylate, polyaspartate, (starch-acrylic acid) graft copolymer, ( acrylic acid-vinyl alcohol) copolymers, (isobutylene-maleic anhydride) copolymers and saponified products thereof. Among these, polyacrylates are preferred, alkali metal polyacrylates are more preferred, and sodium polyacrylate is even more preferred, from the viewpoint of absorption per weight. The superabsorbent polymer 12 can be used individually by 1 type or in combination of 2 or more types.

The superabsorbent polymer 12 is used, for example, in the form of particles, fibers, etc., but is preferably used in the form of particles from the viewpoint of ease of handling. At this time, by avoiding the use of a fine powder superabsorbent polymer 12 with poor fluidity as a powder and using a superabsorbent polymer 12 having a medium particle size, the basic performance related to absorption is improved and the absorption It is possible to reduce the rugged tactile sensation that occurs when the body 20 becomes hard. The median particle size of the superabsorbent polymer 12 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.

A hot-melt adhesive, for example, is used to enclose the superabsorbent polymer 12 in the first block-shaped space 62 and the second block-shaped space 63 . As the hot-melt adhesive, those having a melting point of 100° C. or higher and 180° C. or lower can be used without particular limitation. Hot-melt adhesives, olefin-based hot-melt adhesives such as ethylene-vinyl acetate copolymers, and the like are included. As a method for applying the hot melt adhesive, known methods such as a curtain coating method and a spiral method for non-contact application of the hot melt adhesive in a molten state from a nozzle, and a slot method for contact application can be used. The content of the hot-melt adhesive is, for example, in the range of 10 g/m ² or less from the viewpoint of not impairing the absorbency of the superabsorbent polymer 12 and the touch when worn.

<Method for manufacturing absorbent sheet and absorbent>
The absorbent sheet 25 of the present embodiment leaves, for example, regions scheduled to form the first joints 60 and the second joints 61 on the non-skin side surfaces of the continuous porous polyurethane sheet 21 and the perforated film 22. a step of spraying the superabsorbent polymer 12 in a predetermined pattern; a step of supplying a hot-melt adhesive as necessary to fix and support the superabsorbent polymer 12; The non-skin side of the perforated film 22 is superposed on the non-skin side to which the elastic polymer 12 has been dispersed or adhered, and the pulp fiber web of the composite nonwoven fabric 23 is placed on the non-skin side of the perforated film 22 to which the superabsorbent polymer 12 has been dispersed or adhered. 26 to obtain a laminate, and the step of forming the first joint 60 and the second joint 61 while applying pressure and/or heat to the laminate as necessary. method. The first joint portion 60 and the second joint portion 61 can be formed, for example, by using a hot melt adhesive or by a welding method such as heat sealing or ultrasonic sealing. The absorbent body 20 is obtained by wrapping the obtained absorbent sheet 25 with the hydrophilic sheet 24 as described above. The hot-melt adhesive used here and its application method are the same as those for the hot-melt adhesive for fixing and supporting the superabsorbent polymer 12 .

<Back seat>
The back sheet 30 may be formed using a liquid-impermeable breathable or non-breathable base material that prevents body fluids held by the absorbent body 20 from wetting the clothes. Examples thereof include resin films and composite sheets that are laminates of resin films and nonwoven fabrics. The nonwoven fabric used for the composite sheet is not particularly limited in manufacturing method, and examples include single-layer nonwoven fabrics such as spunbond nonwoven fabrics and meltblown nonwoven fabrics, spunbond nonwoven fabric/meltblown nonwoven fabric laminates, spunbond nonwoven fabric/meltblown nonwoven fabric/spunbond nonwoven fabric laminates. Composite nonwoven fabrics such as bodies, composite materials thereof, and the like. Examples of resin films include polyester, polyvinyl alcohol, polyethylene, polypropylene, composite films of polyethylene and polypropylene, and the like.

The basis weight of the backsheet 30 is, for example, in the range of 15 g/m ² or more and 60 g/m ² or less, or in the range of 15 g/m ² or more and 40 g/m ² or less, from the viewpoint of strength and workability. In addition, it is preferable that the back sheet 30 has air permeability in order to prevent stuffiness during wearing. In order to make the back sheet 30 air-permeable, for example, a filler may be added to the base resin film, or the back sheet 30 may be embossed. Calcium carbonate can be used as a filler, and a known method can be used without limitation as a method for blending the filler.

<Three-dimensional gather>
For example, the three-dimensional gathers 40 extend along the longitudinal direction of the absorbent article 50 near both ends in the width direction of the absorbent article 50 in order to prevent lateral leakage of bodily fluid excreted by the wearer of the absorbent article 50 . is fixed to the skin side of the The three-dimensional gathers 40 include an elastic stretchable member 40a and a water-repellent and/or waterproof sheet member 40b.

The elastic stretchable member 40a is arranged in the vicinity of the free end (the other end) of the sheet member 40b along the longitudinal direction, and provides the free end with uprightness so that the free end of the sheet member 40b and its neighboring area can be used by the wearer. Make it deformable according to the body shape of. In the present embodiment, the sheet member 40b has one widthwise end (fixed end) fixed near both widthwise ends of the skin side surface of the back sheet 30, and a widthwise intermediate portion fixed near both widthwise ends of the skin side surface of the top sheet 10. and the other end in the width direction is a free end having an upright property. The fixing position of the fixed end (one end in the width direction) of the sheet member 40b is not limited to this embodiment. all or part of each edge of the joined body, near both width direction ends of the skin side or non-skin side of the joined body, near both width direction ends of the skin side of the top sheet 10, and the like.

The sheet member 40b is a water-repellent and/or waterproof sheet, and is made of, for example, non-woven fabric. As the nonwoven fabric for the first sheet member, a water-repellent and/or waterproof (liquid-impermeable) nonwoven fabric made of hydrophobic fibers can be used without particular limitation. Composite nonwoven fabrics (SMS nonwoven fabrics), which are nonwoven fabric/meltblown nonwoven fabric/spunbond nonwoven fabric laminates, and the like can be mentioned. The basis weight of the sheet member 40b is, for example, in the range of 13 g/m ² or more and 20 g/m ² or less. As the elastic stretchable member 40a, for example, a string-like, string-like, or belt-like member made of natural rubber, synthetic rubber, polyurethane, or the like can be used as appropriate.

<Method for manufacturing absorbent article>
The absorbent article 50 can be manufactured by a known manufacturing method. A manufacturing method including a step of fixing using a hot-melt adhesive, heat embossing, ultrasonic embossing, high-frequency embossing, etc., and a step of installing three-dimensional gathers 40 at predetermined positions of the back sheet 30 and the top sheet 10. is mentioned. When the absorbent article 50 is a urine absorption pad or a light incontinence pad, the absorbent article 50 may be individually wrapped in a package and then folded in three in the longitudinal direction. In addition, leg gathers, waist gathers, side flaps, etc. can be provided as required.

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

EXAMPLES Examples and comparative examples are given below to describe this embodiment more specifically.

(Examples 1-2 and Comparative Examples 1-7)
(Production of absorbent article)
2 (Examples 1 and 2), FIG. 6 (absorbent article 70 according to Comparative Example 1), FIG. Air-through nonwoven fabric), FIG. 8 (absorbent article 73 according to Comparative Example 4 and absorbent article 74 according to Comparative Example 5 are indicated by reference numeral 28 with air-through nonwoven fabric), FIG. 9 (absorbent article 75 according to Comparative Example 6), and FIG. 10 (absorbent article 76 according to Comparative Example 7) was produced as follows.

A polyurethane open-cell foam sheet (skeletal surface is hydrophilic, basis weight 80 g/m ² , thickness 2.0 mm, apparent density 140 kg/m ³ ) is used as the skin-side material to be placed on the skin side, and an open-cell foam sheet is used as an intermediate material. Perforated films (Examples 1 and 2, Comparative Examples 4 and 5), composite nonwoven fabric (Comparative Example 1), polyurethane open-cell foam sheet (Comparative Example 2) or air-through nonwoven fabric (Comparative Example 3) or intermediate No material (Comparative Examples 6 and 7), composite nonwoven fabric (Examples 1 and 2, Comparative Examples 1 to 3 and 6) as a non-skin side material, and the polyurethane open-cell foam sheet described above (Comparative Examples 4 and 7 ) or an air-through nonwoven fabric (Comparative Example 5) to prepare an absorbent sheet. The obtained absorbent sheet was C-folded and wrapped with a spunbond nonwoven fabric (hydrophilic sheet, grammage: 12 g/m ² ), and an absorbent body with dimensions of 420 mm × 150 mm was used.

In addition, an air-through nonwoven fabric (basis weight: 20 g/m ^{2 ) as a liquid-permeable top sheet, a breathable polyethylene sheet (basis weight: 35 g/m 2 )} as a liquid-impermeable back sheet, and a spunbond non-woven fabric/ A composite nonwoven fabric (basis weight: 15 g/m ² ) obtained by laminating meltblown nonwoven fabric/spunbond nonwoven fabric in this order was used. When the top sheet, the back sheet, and the absorbent body are integrated, the top sheet and the absorbent body skin side are joined using a hot-melt adhesive, and the longitudinal dimensions of Examples 1 to 2 and Comparative Examples 1 to 7 are obtained. An absorbent article having a width of 480 mm and a width of 200 mm was produced.

The absorbent articles of Examples 1-2 and Comparative Examples 1-7 were evaluated as follows. Table 1 shows the results.
(total absorption)
After being immersed in physiological saline for 5 minutes, the water is drained on a wire mesh for 30 seconds, and the difference in weight before and after absorption is measured.
(repeated absorption rate)
Using a jig with a bottom surface of 140 x 100 mm, an outer diameter of 40 mm, an inner diameter of 35 mm, and a weight of 1400 g, 120 ml of physiological saline under load was injected three times at 10 minute intervals, and the time taken to absorb the third injection of 120 ml was measured. do.
(liquid return)
After 10 minutes from the end of measuring the absorption rate three times, the amount of water absorbed is measured by returning it to a 55 mm diameter filter paper for 1 minute under a load condition of 35 gf/cm ² .
(diffusion length)
Measure the maximum length of the part that absorbs the physiological saline solution after the absorption rate is measured three times.

From Table 1, it can be seen that by using an absorbent body in which the absorbent sheet of the present embodiment is C-folded with a hydrophilic sheet, the body fluid absorption amount and repeated absorption rate are maintained at a high level, and the thin absorbent sheet is excellent in liquid backflow prevention. It can be seen that an absorbent article is obtained.

REFERENCE SIGNS LIST 10 Top sheet 12 Super absorbent polymer 20 Absorber 21 Polyurethane continuous porous sheet 22 Perforated film 23 Composite nonwoven fabric 22a Perforations (through holes)
24 Hydrophilic sheet 25 Absorbent sheet 26 Pulp fiber web 27 Spunbond nonwoven fabric 30 Back sheet 40 Three-dimensional gather 40a Elastic stretchable member 40b Sheet member 50 Absorbent article 60 First joint 61 Second joint 62 First block-like space 63 Second block-shaped space

Claims (11)

An absorbent article comprising a liquid-permeable topsheet, a liquid-impermeable backsheet, and an absorbent body provided therebetween,
The absorbent body does not contain absorbent fibers and has an absorbent sheet,
The absorbent sheet is
From the wearer's skin side, at least a continuous porous polyurethane sheet, a porous film, and a composite nonwoven fabric in which a pulp fiber web is laminated and integrated on a spunbond nonwoven fabric are laminated in this order. having a superabsorbent polymer encapsulated therebetween;
Between the polyurethane continuous porous sheet and the perforated film, and between the perforated film and the composite nonwoven fabric, block-shaped spaces enclosing the superabsorbent polymer are formed respectively. An absorbent article characterized in that the absorbent article is joined as follows: The absorbent article according to claim 1, wherein the polyurethane continuous porous sheet has a basis weight of 30 g/m ² or more and 300 g/m ² or less and an apparent density of 100 kg/m ³ or more and 200 kg/m ³ or less. . 3. The absorbent article according to claim 1, wherein the continuous porous polyurethane sheet has a hydrophilic skeleton surface. The perforated film has through holes penetrating from the skin side to the non-skin side, the hole diameter of the through holes is 0.3 mm or more and 1.5 mm or less, and the number of the through holes is 50/cm ² . The absorbent article according to any one of claims 1 to 3, which is the above. 5. The absorbent article according to claim 4, wherein the through holes have different opening diameters between the skin side and the non-skin side, and the difference in opening diameter is 0.03 mm or more and 0.15 mm or less. . The absorbent article according to claim 4 or 5, wherein the opening diameter of the through-hole on the skin side is larger than the opening diameter on the non-skin side. Any one of claims 1 to 5, wherein the strength required to elongate a 25 mm width test piece of the composite nonwoven fabric by 2 mm in the longitudinal direction in a Tensilon tensile test is 1.5 N/25 mm or more and 5.0 N/25 mm or less. 1. The absorbent article according to claim 1. 1. The spunbond nonwoven fabric comprises one or more fibers made of a resin material selected from the group consisting of nylon (trade name), vinylon, polyester, acrylic resin, polyethylene, polypropylene, and polystyrene. 8. The absorbent article according to any one of claims 7. The composite nonwoven fabric is a hydroentangled integrated product of the spunbond nonwoven fabric and the pulp fiber web, and the hydroentanglement is performed when the hole diameter Φ of the water jet nozzle for injecting the water jet is 0.06 mm or more and 0.15 mm or less, The absorbent article according to any one of claims 1 to 8, wherein the water jet nozzle interval is 0.4 mm or more and 1.0 mm or less. 10. The absorbent article according to any one of claims 1 to 9, wherein said composite nonwoven fabric has irregularities on the surface of said pulp fiber web that contacts said superabsorbent polymer. The absorbent according to any one of claims 1 to 10, wherein the basis weight of the superabsorbent polymer enclosed between the sheets is 30 g/ ^m2 or more and 300 g/ ^m2 or less. Goods.

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