JP2021129649A - Absorbent article - Google Patents

Abstract

To provide an absorbent article which has a great body fluid absorption amount, has excellent repetitive absorbency, diffusibility, and absorption rate of the body fluid, and is excellent in wear feelings.SOLUTION: An absorbent article 1 includes a liquid permeable top sheet 10, a liquid impermeable back sheet 12 and an absorber 11 between them. The absorber 11 is provided with a plurality of laminates of compound type nonwoven fabric 20; and a high absorbency polymer 27 encapsulated in the laminates. The compound type nonwoven fabric 20 has a spunbonded nonwoven fabric 21 and a pulp fiber web integrated with the same, and a projection 25 and a recess 26 have irregular parts 30 provided by turns in a surface direction in a prescribed pattern. On the laminates, a plurality of compound type nonwoven fabrics 20 are arranged so that a polymer holding space 24 is formed by the projections 25 facing each other and the recesses 26 face each other. The high absorbency polymer 27 is encapsulated in the polymer holding space 24.SELECTED DRAWING: Figure 3

Description

The present invention relates to absorbent articles.

The composite non-woven fabric made of spunbonded non-woven fabric and pulp fiber web has both strength based on spunbonded non-woven fabric and liquid absorption property based on pulp fiber. It is widely used in various applications such as wipers.

Patent Document 1 discloses a composite non-woven fabric in which a spunbonded non-woven fabric and a pulp fiber web are superposed and integrated by a water flow entanglement treatment in which a high-pressure water jet (water stream) is sprayed onto the spunbonded non-woven fabric. Here, since the spunbonded non-woven fabric has excellent strength as described above, it functions as a backing layer of the manufactured composite non-woven fabric. On the other hand, the pulp fiber web has an excellent liquid absorbing function as described above. Therefore, this composite non-woven fabric is provided to consumers as an excellent wiper product having the advantages of a pulp fiber web having good liquid absorption against both water-based and oil-based liquids and a spunbonded non-woven fabric having excellent strength. Has been done.

On the other hand, even in disposable diapers such as tape stopper type and pants type, and absorbent articles such as urine absorbing pads, composite non-woven fabrics are widely used as members (absorbents) for absorbing body fluids such as urine.

Japanese Patent No. 2533260

However, since it takes time and effort to change disposable diapers, many types that repeatedly absorb body fluids are recently on the market. In the conventional absorbent article using the composite non-woven fabric as an absorber, there is room for further improvement in terms of the amount of body fluid absorbed, absorbency and diffusivity, absorption rate when repeatedly absorbed, wearing feeling, and the like. ..

An object of the present invention is to use a composite non-woven fabric as a constituent member of an absorber, and to have a relatively large amount of body fluid absorbed, excellent absorbability and diffusivity of body fluid, and a high absorption rate even if body fluid is repeatedly absorbed. It is to provide an absorbent article that is maintained and has a good wearing feel.

As a result of diligent research to solve the above problems, the present inventor has succeeded in obtaining a desired absorbent article, and has completed the present invention. The present invention provides, for example, the following absorbent articles (1) to (8) as preferred embodiments.
(1) An absorbent article comprising a liquid-permeable top sheet, a liquid-impermeable back sheet, and an absorber arranged between the top sheet and the back sheet, wherein the absorbent body is provided. Includes a laminate containing one and the other composite nonwoven fabric and a highly absorbent polymer sealed between the composite nonwoven fabrics, wherein the composite nonwoven fabric is one of a spunbonded nonwoven fabric and the spunbonded nonwoven fabric. A convex portion that includes a pulp fiber web integrated with the surface of the fabric and protrudes toward the spunbonded non-woven fabric side in the thickness direction, and a concave portion that is recessed toward the pulp fiber web side in the thickness direction in a predetermined pattern in the surface direction. In the laminated body, the internal space of the convex portion of one of the composite non-woven fabrics and the internal space of the convex portion of the other composite non-woven fabric face each other. One and the other composite non-woven fabric are arranged so as to form a polymer holding space and to face the bottom surface of the recess of one of the composite nonwoven fabrics and the bottom surface of the recess of the other composite nonwoven fabric. , The highly absorbent polymer is an absorbent article enclosed in the polymer holding space.
(2) The absorbent article according to (1) above, wherein the concave portion is interposed between one said convex portion and another convex portion adjacent thereto and has a substantially groove-shaped cross-sectional view.
(3) The bottom surface of the recess of the composite non-woven fabric on one side and the bottom surface of the recess of the concave fabric of the other composite non-woven fabric are used for body fluid absorption of the highly absorbent polymer enclosed in the polymer holding space. The absorbent article according to (1) or (2) above, which is joined to such an extent that it is separated by the accompanying swelling.
(4) The pattern of the uneven portion is a grid pattern, a wavy pattern, an Aicon pattern, a polka dot pattern, a scale pattern or a checkered pattern, or a plurality of polygons are arranged at equal intervals in the vertical and horizontal directions. The absorbent article according to any one of (1) to (3) above, which is a pattern.
(5) the height of the inner space of the convex portion is 0.2mm or more 3.0mm or less, the area of the bottom surface of the convex portion is at 7 mm ² or more 95 mm ² or less, the opening area of the area ratio (the recess : The absorbent article according to any one of (1) to (4) above, wherein the convex portion has a top surface area of 38:62 or more and 62:38 or less.
(6) The absorbent article according to any one of (1) to (5) above, wherein the composite non-woven fabric is a water flow entangled integrated product of the spunbonded non-woven fabric and the pulp fiber web.
(7) In the water flow entanglement integrated product, at least a part of the wood pulp fibers are entangled with the fibers constituting the spunbonded nonwoven fabric and / or other wood pulp fibers and fixed to one surface of the spunbonded nonwoven fabric. The absorbent article of (6) above, comprising a pulp fiber web and wood pulp fibers exposed outward from the other side of the spunbonded nonwoven fabric.
(8) The absorbent article according to any one of (1) to (7) above, wherein the spunbonded non-woven fabric is a spunbonded non-woven fabric made of polypropylene.

According to the present invention, while using the composite non-woven fabric as a constituent member of the absorber, the amount of body fluid absorbed is relatively large, the body fluid is excellent in absorbency and diffusivity, and the absorption rate is high even if the body fluid is repeatedly absorbed. An absorbent article that is maintained and comfortable to wear is provided.

It is a top view which shows typically the structure of the absorbent article which concerns on 1st Embodiment of this invention. In X ₁ -X ₁ section line shown in FIG. 1 is a schematic sectional view of an absorbent article according to the first embodiment. It is a top view which shows typically the uneven part of the composite nonwoven fabric in an absorber. It is a schematic cross-sectional view of the absorbent body in the Y ₁ -Y ₁ cutting line shown in FIG. It is a schematic cross-sectional view of the absorber after body fluid absorption.

Hereinafter, the absorbent article of the present embodiment will be described in detail with reference to the drawings. FIG. 1 is a schematic plan view of the configuration of the absorbent article 1 according to the first embodiment. FIG. 2 is a schematic cross-sectional view in the width direction of the absorbent article 1. FIG. 3 is a schematic plan view of the composite nonwoven fabric 20 in the absorber 11 as viewed from the spunbonded nonwoven fabric 21 side, schematically showing the uneven portion 30 of the composite nonwoven fabric 20. FIG. 4 is a schematic cross-sectional view of the absorber 11. FIG. 5 is a schematic cross-sectional view of the absorber 11 after absorbing body fluid. Each figure does not specify the size relationship or shape of the dimensions of each component member. Further, although FIG. 2 shows the layers of the constituent members so as to be in close contact with each other in the thickness direction, there may be at least one gap between at least one layer.

In the present specification, it is defined as follows. Wearing the absorbent article 1 means wearing the absorbent article 1 on the body before and after absorbing the body fluid. The absorbent article 1 is worn on the body inside the clothes, but may be worn on the body so that at least a part thereof is exposed to the outside. The longitudinal direction is the direction indicated by the symbol Y in the figure extending to the front and back of the body through the crotch portion of the wearer when the absorbent article 1 is worn on the body, and the width direction is orthogonal to the longitudinal direction. The direction indicated by the middle code X, and the thickness direction is the direction in which the constituent members are laminated. The skin side surface and the non-skin side surface are the surface that comes into contact with the wearer's skin and the surface that faces the skin, and the surface that comes into contact with the wearer's clothes or the surface that faces the clothes, respectively, when the absorbent article 1 is worn. be. Body fluid refers to the liquid excreted from the body such as urine, blood, and water in loose stool.

<Absorbable article>
The absorbent article 1 of the present embodiment can be used as various absorbent articles regardless of whether it is for babies or adults, but typically, a light incontinence pad, a urine absorbing pad, a pants-type disposable diaper, a tape-stopping disposable diaper, etc. Can be mentioned. Various paper diapers as an outer and an absorbent article 1 as an inner may be combined. The dimensions of the absorbent article 1 in the longitudinal direction and the width direction are not particularly limited, but are, for example, 100 mm or more and 800 mm or less, and 50 mm or more and 500 mm or less, respectively. By adjusting the dimensions of the absorbent article 1 to the above range, absorbent articles of various uses can be obtained.

The following is a schematic description of the absorbent article 1 of the present embodiment.
As shown in FIGS. 1 and 2, the absorbent article 1 of the present embodiment faces the liquid-permeable top sheet 10 and the top sheet 10 which are located relatively on the skin side when worn. The liquid-impermeable back sheet 12 located on the non-skin side relatively when worn, the absorber 11 arranged between the top sheet 10 and the back sheet 12, and the top sheet. A pair of three-dimensional gathers 13 provided on the side surface of the skin of 10 are provided. The absorber 11 is sandwiched between the top sheet 10 and the back sheet 12, and body fluids such as urine are absorbed and held by the absorber 11 through the top sheet 10. Leg gathers, waist gathers, side flaps and the like can be appropriately provided depending on the use and type of the absorbent article 1.

As shown in FIG. 4, the absorber 11 includes a laminate of two composite nonwoven fabrics 20 and a highly absorbent polymer 27 sealed between the composite nonwoven fabrics 20. The composite non-woven fabric 20 includes a spunbonded non-woven fabric 21 and a pulp fiber web 22 integrated therein, and further has an uneven portion 30. Here, the integration of the spunbonded nonwoven fabric 21 and the pulp fiber web 22 means that they are firmly fixed to each other and peeling occurs to such an extent that the function of the composite nonwoven fabric 20 is impaired during the use of the absorbent article 1. Means not.

The uneven portion 30 has a convex portion 25 protruding toward the spunbonded nonwoven fabric 21 side in the thickness direction of the composite nonwoven fabric 20 and a concave portion 26 recessed toward the pulp fiber web 22 side in a predetermined pattern in the surface direction of the composite nonwoven fabric 20. It is provided alternately. Then, one and the other composite non-woven fabric 20 are laminated so that the respective pulp fiber web 22 sides are overlapped and the respective convex portions 25 and the concave portions 26 face each other. As a result, a polymer holding space 24 in which the highly absorbent polymer 27 is sealed is formed between the convex portions 25 of the one and the other composite non-woven fabric 20, and the concave portions 26 of the one and the other composite nonwoven fabric 20 are respectively formed. The bottom surface of the pulp fiber web 22 side becomes a contact surface or a loose bonding surface 23, and the polymer holding space 24 becomes a tentatively closed space (FIGS. 3 and 4).

According to the present embodiment, even if the top sheet 10 is locally exposed to a large amount of body fluid, the pulp fiber web 22 supported by the spunbonded non-woven fabric 21 and originally having good liquid absorption and liquid diffusivity is three-dimensional. By having the shape (the uneven portion 30, particularly the concave portion 26 functions as a diffusion path), the above-mentioned characteristics are further improved, so that the body fluid spreads over almost the entire surface of the absorber 11 in a short time. Since the body fluid that has spread over the entire surface is absorbed and retained by the highly absorbent polymer 27 enclosed in the polymer holding space 24, the utilization rate of the highly absorbent polymer 27 in the absorber 11 is remarkably improved, and the absorber The body fluid absorption capacity of 11 is enhanced, and the diffusivity and absorption rate are remarkably improved. As shown in FIG. 5, a part of the highly absorbent polymer 27 gradually swells greatly with the absorption of body fluid, and pushes up the polymer holding space 24 and thus the composite non-woven fabric 20 in the thickness direction of arrow A and / or arrow B. Push down in the thickness direction of. At the same time, on the contact surface or the loose joint surface 23, the bottom surfaces of the two recesses 26 facing each other on the pulp fiber web 22 side expand in the thickness direction to communicate the adjacent polymer holding spaces 24. Then, the remaining portion of the highly absorbent polymer 27 absorbs the body fluid to form a swellable space, and the expanded space prevents gel blocking by the highly absorbent polymer 27 that absorbs the body fluid and swells. NS. As a result, the body fluid can be repeatedly absorbed, and the absorption rate does not decrease. Therefore, according to the present embodiment, the body fluid is excellent in absorbability and diffusivity, the amount of body fluid absorbed is relatively large, the body fluid can be repeatedly absorbed a plurality of times, and the absorption rate is lowered even if the body fluid is repeatedly absorbed. However, the absorbent article 1 can be provided.

Further, the absorber 11 having the highly absorbent polymer 27 encapsulated between the composite nonwoven fabric 20 as described above has a relatively thin composite nonwoven fabric 20 itself and a relatively high absorbent polymer 27. If it is made into particles having a small diameter, it can be made thin. Further, the highly absorbent polymer 27 is covered with the composite non-woven fabric 20. Further, mainly due to the above-mentioned action of the pulp fiber web 22, the entire highly absorbent polymer 27 can be efficiently utilized, and even after repeated absorption of body fluid, a local and remarkable increase in thickness is unlikely to occur. From the above, the absorbent article 1 of the present embodiment is very good because excessive gel blocking due to the swelling chain of the highly absorbent polymer 27 is unlikely to occur before and after body fluid absorption, and the development of a rugged feeling is suppressed. It has a comfortable wearing feeling.
Hereinafter, each of the sheet-shaped or plate-shaped constituent members will be described in detail step by step. Each component may have a three-dimensional shape other than a sheet shape or a plate shape.

(Top sheet)
The top sheet 10 is a liquid-permeable sheet-like member that allows body fluids to quickly pass toward the absorber 11. As the top sheet 10, a liquid-permeable material can be used without particular limitation, but since it may come into contact with the wearer's skin, a base material having a soft feel and not irritating to the skin. Is preferable. Examples of the base material include a hydrophilic non-woven fabric, a composite non-woven fabric which is a laminate of the same or different types of hydrophilic non-woven fabric, an open film such as an open polyethylene film, and a foam film such as a urethane foam film. As the hydrophilic non-woven fabric, for example, synthetic fibers made of synthetic resin such as polypropylene and polyethylene, recycled fibers such as rayon, and natural fibers such as cotton are used, and known methods such as air-through method, thermal bond method, spunlace method, and spunbond method are used. It is obtained by processing by the method of.

The surface of the top sheet 10 may be embossed or perforated in order to improve liquid permeability. The embossing and drilling can be performed according to, for example, a known method. Further, in order to reduce irritation to the skin, the top sheet 10 may contain a lotion, an antioxidant, an anti-inflammatory component, a pH adjuster, an antibacterial agent, a moisturizer and the like. From the viewpoint of strength, workability and liquid return amount, the basis weight of the top sheet 10 is, for example, 15 g / m ² or more and 40 g / m ² or less. The shape of the top sheet 10 is not particularly limited, but may be any shape that covers the absorber 11, which is required to guide the body fluid to the absorber 11 so as not to leak.
In the present embodiment, the top sheet 10 covers not only the skin side surface of the absorber 11 but also the side surface of the absorber 11, but the top sheet 10 covers only the skin side surface of the absorber 11. It also includes a covering embodiment.

(Absorber)
The absorber 11 is arranged between the top sheet 10 and the back sheet 12, and absorbs and retains body fluids, for example. As shown in FIGS. 3 and 4, for example, the absorber 11 of the present embodiment has a form in which the highly absorbent polymer 27 is encapsulated between two composite non-woven fabrics 20. The number of laminated composite non-woven fabrics 20 of the present embodiment is not limited to two, and any number of laminated fabrics can be selected for three or more. The composite non-woven fabric 20 includes a spunbonded non-woven fabric 21 and a pulp fiber web 22 integrated therein, and has an uneven portion 30 on the entire surface thereof. In the present embodiment, the uneven portion 30 is formed on the entire surface of the composite nonwoven fabric 20, but the present invention is not limited to this, and may be formed on a part of the composite nonwoven fabric 20.

Further, in the absorber 11 of the present embodiment, the pulp fiber webs 22 of the two composite nonwoven fabrics 20 face each other and partially contact each other, and the convex portions 25 of the two composite nonwoven fabrics 20 face each other. Two composite types so that the polymer holding space 24 is formed and the recesses 26 of the two composite type non-woven fabrics 20 face each other and the bottom surface on the pulp fiber web 22 side becomes a contact surface or a loose joint surface 23. The non-woven fabric 20 is laminated. The material constituting the composite nonwoven fabric 20 will be described later, and here, the uneven portion 30 will be described first.

As shown in FIG. 3, the uneven portion 30 of the present embodiment is provided with convex portions 25 having a substantially hexagonal top surface and groove-shaped concave portions 26 alternately provided in a predetermined pattern in the surface direction of the composite nonwoven fabric 20. Has the desired form. The pattern of the present embodiment is one convex portion 25, six peripheral convex portions 25 in the left-right direction, the upper diagonal left-right direction, and the lower diagonal left-right direction, and one side of the six sides of the hexagon. Is a pattern arranged so as to be substantially parallel to each other and separated from each other by recesses 26 arranged along the periphery of the convex portion 25, and a plurality of polygons are arranged at equal intervals in the vertical and horizontal directions. Is one embodiment. Here, examples of the polygon include a substantially equilateral triangle, a substantially square, a substantially rectangle, a substantially rhombus, a substantially parallelogram, a substantially pentagon, a substantially polygon of a hexagon or more, and the like. The pattern of the uneven portion 30 is not limited to the present embodiment, and may be a grid pattern, a wavy shape, an akon pattern (continuous shape of acorns), a polka dot pattern, a scale pattern, a checkered pattern, or the like. Further, a pattern in which two or more patterns are combined may be used. It is obvious that the same effect can be obtained because all the patterns are the same in that the polymer holding space 24, which is a closed space, is formed.

The convex portion 25 of the present embodiment is a flat surface that protrudes toward the spunbonded nonwoven fabric 21 (or topsheet 10) in the thickness direction of the composite nonwoven fabric 20 and whose top surface has a substantially hexagonal plan view shape. The recess 26 is a groove that is recessed on the pulp fiber web 22 (or backsheet 12) side and extends linearly while being bent along the edge of the convex portion 25, and tends to be a diffusion path for body fluids. Therefore, the recess 26 further improves the liquid absorption property and the body fluid diffusivity inherent in the pulp fiber web 22, and makes almost all the highly absorbent polymer 27 in the absorber 11 available for absorption of the body fluid. The recess 26 may have an inverted trapezoidal shape in cross section (a shape in which the diameter of the opening is larger than the diameter of the bottom surface), a U shape, a V shape, or the like. The width dimension a (FIG. 3) of the opening of the concave portion 26 is appropriately selected according to the area of the top surface of the convex portion 25, the shape in a plan view, the arrangement pattern of the convex portion 25 and the concave portion 26, and the like, which will be described later. From the viewpoint of realizing a loosely joined state, it is, for example, 0.3 mm or more and 1.0 mm or less.

The convex portion 25 of one composite nonwoven fabric 20 (hereinafter, also referred to as “one convex portion 25”) and the convex portion 25 of the other composite nonwoven fabric 20 (hereinafter, also referred to as “other convex portion 25”) are the same. The internal spaces face each other to form the polymer holding space 24. The highly absorbent polymer 27 enclosed in the polymer holding space 24 may or may not be fixed to the surface of the pulp fiber web 22 which is the inner wall surface of the polymer holding space 24, and a part thereof is fixed. Moreover, the balance does not have to be fixed. For example, a hot melt adhesive or the like is used for fixing the highly absorbent polymer 27.

The height of the internal space of the convex portion 25 is a balance between the amount of the highly absorbent polymer 27 enclosed in the polymer holding space 24 and the thickness of the absorber 11 at the time when the body fluid is absorbed to the maximum, and the shape of the convex portion 25. From the viewpoint of retention and the like, it is, for example, 0.2 mm or more and 3.0 mm or less. Here, the height of the internal space of the convex portion 25 is the height in the direction perpendicular to the virtual surface in which a plurality of contact surfaces or loose joint surfaces 23 are connected in the vertical and horizontal directions. Further, the area of the opening on the pulp fiber web 22 side of the convex portion 25 is, for example, 7 mm ² or more and 95 mm ² or less from the viewpoint of adjusting the encapsulation amount of the highly absorbent polymer 27. When the convex portion 25 is a columnar body, the area of the top surface of the convex portion 25 and the area of the opening on the pulp fiber web 22 side are substantially equal to each other.

Also. The bottom surface (hereinafter, also referred to as "bottom surface of one recess 26") on the pulp fiber web 22 (or back sheet 12) side of the recess 26 (hereinafter, also referred to as "one recess 26") of the composite non-woven fabric 20 and others. The bottom surface (hereinafter, also referred to as “the bottom surface of the other recess 26”) on the pulp fiber web 22 (or back sheet 12) side of the recess 26 (hereinafter, also referred to as “the other recess 26”) of the composite nonwoven fabric 20 is shown in FIG. As shown in 4, they face each other and become a contact surface or a loose joint surface 23. Here, loose bonding means that the bottom surfaces of one and the other recesses 26 are bonded to each other to make each polymer holding space 24 a closed space, but when the highly absorbent polymer 27 absorbs body fluid and swells, the bonding is performed. A joint in which the joint state is eliminated as the volume expands and the bottom surfaces of one and the other recesses 26 are separated from each other. Here, as the joining method, known methods such as heat fusion and ultrasonic bonding can be used. For loose bonding, the encapsulation amount of the highly absorbent polymer 27 is kept constant, various bonding conditions are set, repeated experiments are repeated, and the loose bonding described above is performed according to the encapsulation amount of the high absorption polymer 27. The joining conditions that can realize the joining may be appropriately selected.

On the surface of the composite non-woven fabric 20 on the spunbonded non-woven fabric 20 side, the area ratio (opening area of the concave portion 26: top surface area of the convex portion 25) is the viewpoint of the encapsulation amount of the highly absorbent polymer 27, the bonding strength, ensuring diffusivity, and the like. Therefore, for example, it is 38:62 or more and 62:38 or less. The dimensions of the convex portion 25 and the concave portion 26 are obtained by using, for example, an analysis application of a one-shot 3D shape measuring machine (trade name: controller VR-3000 Series, manufactured by KEYENCE CORPORATION). For example, when the height difference between the convex portion 25 and the concave portion 26 is measured using the analysis application, the height of the convex portion 25 and the depth of the concave portion 26 can be obtained. Further, when the distance between the centers of the convex portions 25 is measured, the distance between the convex portions 25 can be obtained.

As the highly absorbent polymer (hereinafter, also referred to as “SAP”) 27 used in the present embodiment, various polymers capable of absorbing and retaining body fluid and preventing backflow of body fluid can be used without particular limitation, for example, polyacrylic acid salt. , Polyasparaginate, (starch / acrylic acid) graft copolymer, (acrylic acid / vinyl alcohol) copolymer, (isobutylene / maleic anhydride) copolymer and its saponified products, etc. A polymer contained as a constituent unit can be mentioned. The highly absorbent polymer 27 can be used alone or in combination of two or more. Among these, polyacrylate is preferable, and sodium polyacrylate is more preferable, from the viewpoint of the amount of body fluid absorbed per weight. The form of the highly absorbent polymer 27 is not particularly limited, but it is preferably in the form of particles from the viewpoint of encapsulation in the polymer holding space 24. The average particle size of the highly absorbent polymer 27 is, for example, 150 μm or more and 550 μm or less. ^{Further, the basis weight of the highly absorbent polymer 27 is, for example, 90 g / m 2} or more and 240 g / from the viewpoint of the balance between the body fluid absorption capacity (body fluid absorption amount) of the absorber 11 and the wearing feeling after repeatedly absorbing the body fluid. It is m ² or less.

As the spunbonded non-woven fabric 21 of the composite non-woven fabric 20, a non-woven fabric produced by a spunbond method, a melt blow method, a flash spinning method or the like can be used without particular limitation, and examples of the material thereof include nylon (trade name) and vinylon. , Polyester, acrylic resin, polyethylene, polypropylene, polystyrene and other synthetic resins can be preferably used. The spunbonded nonwoven fabric 21 may contain a plurality of synthetic resin fibers. Among these, the spunbonded non-woven fabric 21 containing polypropylene fibers is preferable, and the spunbonded non-woven fabric 21 in which all the constituent fibers are polypropylene fibers is more preferable from the viewpoint of strength, softness, absorbability and the like. The basis weight of the spunbonded nonwoven fabric 21 is not particularly limited, but is, for example, 7 g / m ² or more and 20 g / m ² or less from the viewpoint of tensile strength and softness of touch.

The pulp fiber web 22 is not particularly limited, but for example, a layer made of a non-woven fabric mainly composed of wood pulp fibers (hereinafter, also referred to as “wood pulp non-woven fabric”), a layer in which wood pulp fibers are entangled with each other, and a very small amount of wood pulp fibers. Examples thereof include a layer fixed with an adhesive or a binder. Among these, a layer in which wood pulp fibers are entangled with each other is preferable from the viewpoint of strength, softness and the like. The wood pulp fiber used here is not particularly limited, and examples thereof include coniferous bleached kraft pulp (hereinafter, also referred to as “NBKP”) such as radiata pine, slash pine, southern pine, lodge pole pine, spruce and douglas fur. Be done. NBKP can be used alone or in combination of two or more. The basis weight of the pulp fiber web 22 is not particularly limited, but is, for example, 30 g / m ² or more and 70 g / m ² or less from the viewpoint of uniformity, tactile sensation, absorbability and the like.

The content of the wood pulp fiber is, for example, 65% by mass or more and 90% by mass or less of the total amount of the composite nonwoven fabric 20, and the balance is spunbonded nonwoven fabric 21 or 70% by mass or more and 85% by mass or less, and the balance is. The spunbonded non-woven fabric 21. If the content of the wood pulp fiber is less than 65% by mass, the composite non-woven fabric 20 that is stable in terms of absorption and diffusivity of body fluid tends not to be formed, and if it exceeds 90% by mass, the composite non-woven fabric 20 becomes hard. Tend.

The basis weight of the composite nonwoven fabric 20 as a whole is, for example, 40 g / m ² or more and 80 g / m ² or less, or 40 g / m ² or more and 60 g / m ² or less. If it is less than 40 g / m ² , the composite non-woven fabric 20 tends to be too soft, and if ^{it exceeds 80 g / m 2} , the composite non-woven fabric 20 tends to be too hard.

Further, with respect to the composite nonwoven fabric 20, the force (tensile strength) required to stretch the test piece formed in a width of 25 mm by 2 mm in the vertical direction in the tensile strength test with Tencilon is not particularly limited, but is, for example, 1.5 N /. It is 25 mm or more and 5.0 N / 25 mm or less.

The thickness of the composite non-woven fabric 20 is, for example, 0.25 mm or more and 0.50 mm or less when measured using a thickness gauge (trade name: dial thickness gauge "PEACOCK" (registered trademark), manufactured by Ozaki Seisakusho Co., Ltd.). , Or 0.30 mm or more and 0.45 mm or less. If the value is lower than this range, the composite non-woven fabric 20 tends to be too soft, and the composite non-woven fabric 20 tends to be unable to be stably fixed during the production of the absorbent article 1. Further, when the value is higher than this range, the composite nonwoven fabric 20 tends to be hard.

The spunbonded non-woven fabric 21 and the pulp fiber web 22 can be integrated by, for example, a thermocompression bonding method, a water flow entanglement method, or an adhesive-based integration. Among these methods, if the water flow confounding method is used, a composite non-woven fabric 20 having both appearance, softness of touch and strength can be obtained. According to the water flow entanglement method, the wood pulp fibers are entangled in the pulp fiber web 22 by spraying the wood pulp fibers together with the water flow on the non-skin side surface of the spunbonded non-woven fabric 21 without using a binder or an adhesive. The constituent fibers of the spunbonded nonwoven fabric 21 and the wood pulp fibers are entangled to obtain a water flow entangled integrated product in which the spunbonded nonwoven fabric 21 and the pulp fiber web 22 are firmly integrated.

As one embodiment of such a water flow entanglement integrated product, at least a part of the wood pulp fibers are entangled with the fibers (synthetic resin fibers) constituting the spunbonded non-woven fabric 21 and / or other wood pulp fibers, and the spunbonded non-woven fabric 21 Examples thereof include a water flow entangled integrated product containing a pulp fiber web 22 fixed to one surface and a wood pulp fiber penetrating a spunbonded non-woven fabric in the thickness direction and projecting outward from the other surface. When the above-mentioned uneven portion 30 is formed in this embodiment, the wood pulp fibers are exposed on the surface of the convex portion 25 and the concave portion 26 on the spunbonded non-woven fabric 21 side, and the exposed wood pulp fibers serve as a guide path for body fluids and become the uneven portion. The three-dimensional structure (particularly the recess 26) of 30 and the pulp fiber web 22 cooperate synergistically to obtain extremely rapid diffusion and absorption retention of body fluid throughout the absorber 11, increasing the absorption rate and causing wet back. improves. The water flow entangled integrated product of the above embodiment can be obtained, for example, by appropriately adjusting the pressure of the water flow sprayed on the spunbonded nonwoven fabric 21. Among the water-flow entangled integrated products of the above embodiment, it is more preferable that the spunbonded non-woven fabric 21 is a spunbonded non-woven fabric made of polypropylene from the viewpoint of strength, softness, and absorbency.

The uneven portion 30 is formed on the composite non-woven fabric 20 by, for example, embossing. Examples of the embossing include known methods such as heat embossing, ultrasonic embossing, and high frequency embossing. Pressurization and / or heating and embossing may be performed at the same time.

The planar shape of the absorber 11 is an hourglass shape (not shown) in the present embodiment, but is not limited to this, and is not limited to, for example, a substantially rectangular shape (rectangular shape), an I shape, an oval shape, an elliptical shape, and a rectangular shape. It can be shaped like a rounded rectangle with rounded corners. The absorber 11 may be used by stacking two or more layers. The thickness of the absorber 11 is appropriately selected according to the type of body fluid to be absorbed, the form and material of the absorber 11, and the like. Further, from the viewpoints of absorbability and retention of body fluid, shape retention of the absorber 11, prevention of SAP falling off, and the like, the entire absorber 11 may be coated with a hydrophilic sheet, if necessary.

<Preparation of absorber>
For the absorber 11, for example, one composite non-woven fabric 20 with the top surface of the convex portion 25 facing downward is prepared, and the highly absorbent polymer 27 is stored in the internal space of the convex portion 25 in a fixed and / or non-fixed manner. Another composite non-woven fabric 20 is laminated on this with the top surface of the convex portion 25 facing upward, and the edges of one and the other composite non-woven fabric 20 around four circumferences are joined, and if necessary, the pulp of the concave portion 26 is joined. It can be produced by loosely joining the bottom surfaces of the fiber web 22 side to each other. It is also possible to simultaneously join the four peripheral edges of one and the other composite non-woven fabric 20 and the bottom surfaces of the recesses 26 on the pulp fiber web 22 side.

(Back sheet)
The backsheet 12 is arranged on the most non-skin side of the absorbent article 1, for example, a breathable or non-breathable liquid such that the body fluid held by the absorber 11 does not wet clothing or adhere to the skin surface. It consists of an impermeable substrate. Examples of the liquid-impermeable substrate for the back sheet include a resin film, a composite sheet which is a laminate of a resin film and a non-woven fabric, and the like. Examples of the resin film include a film made of a synthetic resin such as polyester, polyvinyl alcohol, polyethylene, and polypropylene, and a composite film which is a laminate of a polyethylene film and a polypropylene film. The non-woven fabric used for the composite sheet is not particularly limited in the manufacturing method. Examples thereof include a composite non-woven fabric which is a laminated body with.

The basis weight of the back sheet 12 is not particularly limited, but is, for example, 15 g / m ² or more and 40 g / m ² or less from the viewpoint of strength and workability. Further, in order to prevent stuffiness when worn, there is a form in which the back seat 12 is provided with breathability. The method of imparting breathability to the backsheet 12 is not particularly limited, and a known method can be adopted. For example, a method of making the resin film which is the base material for the backsheet porous, and embossing the base material for the backsheet. There is a method of applying. As an example of the method of making the resin film porous, there is a method of adding a filler to the resin to form a film, and removing the filler from the obtained film. Examples of the filler include inorganic salts such as calcium carbonate.

(Three-dimensional gather)
The three-dimensional gather 13 is provided, for example, to prevent lateral leakage of body fluid excreted by the wearer of the absorbent article 1. In the three-dimensional gather 13 of the present embodiment, one end in the width direction is fixed near both ends in the width direction of the skin side surface of the back sheet 12, and the middle part in the width direction is fixed near both ends in the width direction of the top sheet 10. The three-dimensional gather sheet 13a, which has free ends and covers the periphery of both ends in the width direction of the top sheet 10 and extends in the longitudinal direction, and the three-dimensional gather sheet 13a are arranged so as to extend in the longitudinal direction near the free ends. It is a constituent member that includes the elastic elastic member 13b and is provided so as to be bendable from an intermediate portion in the width direction of the three-dimensional gather sheet 13a. By arranging the elastic elastic member near the free end of the three-dimensional gather sheet 13a, the free end is provided with erectability and can be deformed according to the wearer's body shape. In the present embodiment, one end of the three-dimensional gather 13 in the width direction is fixed to the skin side surface of the back sheet 12. The present invention is not limited to this, and for example, one end in the width direction may be fixed to the non-skin side surface of the back sheet 12, may be fixed to a bag body composed of the top sheet 10 and the back sheet 12, and further. , May be fixed to the skin side surface of the top sheet 10.

The three-dimensional gather sheet 13a is a laminated body of a water-repellent or liquid-impermeable non-woven fabric formed of hydrophobic fibers, for example, a spunbonded non-woven fabric, a melt-blown non-woven fabric, and a spunbond occupation / melt-blow non-woven fabric / spunbonded non-woven fabric. Examples include composite woven fabrics. Examples of the elastic elastic member 13b include thread-shaped, string-shaped, and strip-shaped members made of natural rubber, synthetic rubber, polyurethane, and the like. The absorbent article 1 of the present embodiment also includes an embodiment that does not include the three-dimensional gather 13.

<Manufacturing method of absorbent articles>
The method for producing the absorbent article 1 is not particularly limited, and a conventionally known method can be adopted. For example, the back sheet 12, the absorber 11, and the top sheet 10 are laminated in this order from the clothing side, and the top sheet is used. It can be manufactured by fixing the 10 and the back sheet 12 with a hot melt adhesive, heat embossing, ultrasonic embossing, high frequency embossing, or the like over a part or the entire circumference, and further attaching a three-dimensional gather 13. Then, this may be individually wrapped in a package, and then folded in three in the longitudinal direction.

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 above embodiments, and various changes or improvements are made to the above embodiments. It is clear to those skilled in the art that is possible. Further, it is clear from the description of the scope of claims that the form to which such a modification or improvement is added may be included in the technical scope of the present invention.

1 Absorbent article 10 Top sheet 11 Absorber 12 Back sheet 13 Three-dimensional gather 13a Three-dimensional gather sheet 13b Elastic stretchable member 20 Composite non-woven fabric 21 Spunbond non-woven fabric 22 Pulp fiber web 23 Contact surface or loose joint surface 24 Polymer holding space 25 Convex part 26 Concavities 27 Highly absorbent polymer 30 Concavities and convexities

Claims (8)

An absorbent article comprising a liquid-permeable top sheet, a liquid-impermeable back sheet, and an absorber disposed between the top sheet and the back sheet.
The absorber comprises a laminate containing one and the other composite nonwoven fabric and a highly absorbent polymer encapsulated between the composite nonwoven fabrics.
The composite non-woven fabric includes a spunbonded nonwoven fabric and a pulp fiber web integrated on one surface of the spunbonded nonwoven fabric, and has a convex portion protruding toward the spunbonded nonwoven fabric in the thickness direction and a convex portion in the thickness direction. It has concave portions that are recessed on the web side of the pulp fiber, and uneven portions that are alternately provided in the plane direction in a predetermined pattern.
In the laminated body, the internal space of the convex portion of one of the composite non-woven fabrics and the internal space of the convex portion of the other composite non-woven fabric face each other to form a polymer holding space, and the composite of one of them. One and the other composite non-woven fabric are arranged so that the bottom surface of the recess of the molded non-woven fabric and the bottom surface of the recess of the other composite non-woven fabric face each other.
The highly absorbent polymer is an absorbent article encapsulated in the polymer holding space. The absorbent article according to claim 1, wherein the concave portion is interposed between one said convex portion and another convex portion adjacent thereto and has a substantially groove-shaped cross-sectional view. The bottom surface of the recess of the composite non-woven fabric on one side and the bottom surface of the recess of the composite non-woven fabric on the other are swelled due to the absorption of body fluid of the highly absorbent polymer sealed in the polymer holding space. The absorbent article according to claim 1 or 2, which is joined to such an extent that it is separated from each other. The pattern of the uneven portion is a grid pattern, a wavy pattern, an aicon pattern, a polka dot pattern, a scale pattern or a checkered pattern, or a pattern in which a plurality of polygons are arranged at equal intervals in the vertical and horizontal directions. The absorbent article according to any one of claims 1 to 3. The height of the inner space of the convex portion is 0.2mm or more 3.0mm or less, the area of the bottom surface of the convex portion is at 7 mm ² or more 95 mm ² or less, the opening area of the area ratio (the recess: the convex The absorbent article according to any one of claims 1 to 4, wherein the top surface area of the portion is 38:62 or more and 62:38 or less. The absorbent article according to any one of claims 1 to 5, wherein the composite non-woven fabric is a water-flow entangled integrated product of the spunbonded non-woven fabric and the pulp fiber web. In the water flow entanglement integrated product, at least a part of the wood pulp fibers are entangled with the fibers constituting the spunbonded nonwoven fabric and / or other wood pulp fibers, and the pulp fiber web is fixed to one surface of the spunbonded nonwoven fabric. The absorbent article according to claim 6, comprising the wood pulp fiber exposed to the outside from the other surface of the spunbonded nonwoven fabric. The absorbent article according to any one of claims 1 to 7, wherein the spunbonded non-woven fabric is a spunbonded non-woven fabric made of polypropylene.

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