Absorbent article

Abstract

To provide an absorbent article having a soft, thin absorbent sheet which excels in an absorption rate and an absorption amount even after absorbing body fluid several times, is capable of preventing body fluid leakage and liquid return, and provides good wearing comfort.SOLUTION: In an absorbent article 50 having a top sheet 10, an absorber 20 and a back sheet 30: the absorber 20 has an absorbent sheet; the absorbent sheet is a lamination of a first hydrophilic non-woven fabric 21, a first SAP layer 23, a second hydrophilic non-woven fabric 21, a second SAP layer 23 and a pulp sheet 22 in the order from a wearer's skin side; the absorbent sheet has embossed grooves 15 extending from the skin-side surface to the skin-side surface of the pulp sheet 22; and the embossed grooves 15 are a first embossed groove 16 extending in a longer direction in a width direction center of the skin-side surface of the absorbent sheet and a second embossed groove 17 provided in a rectangular shape in plan view on the skin-side surface of the absorbent sheet, with vertexes of its opposite vertex angles in the longer direction of the absorbent sheet being positioned on the first embossed groove 16.SELECTED DRAWING: Figure 2

Description

Technical Field

[0001] The present invention relates to absorbent articles.

Background Art

[0002] Absorbent articles include a liquid-permeable topsheet positioned on the skin side, a liquid-impermeable backsheet positioned on the non-skin side, and an absorber disposed between them. The absorber absorbs and holds the body fluid that has passed through the topsheet, and the backsheet is configured so that the body fluid does not adhere to the wearer's clothing or the like. Absorbent articles include, for example, pad products such as light incontinence pads, light incontinence liners, urine absorbent pads, sanitary napkins, and paper diaper products such as pant-type paper diapers and tape-fastened type paper diapers. There are various forms depending on the application, and they are widely used regardless of whether the user is an infant, an adult, or an elderly person.

[0003] In conventional absorbent articles, as an absorber, a fluff absorber containing absorbent fibers such as fluff pulp and a super absorbent polymer (hereinafter also referred to as "SAP") is widely used. However, the fluff absorber has a problem that it absorbs body fluids such as urine and becomes relatively thick, making it easy to stand out to others. In addition, the number of people who can walk while wearing absorbent articles is increasing. For this reason, recently, thin absorbent articles that are not noticeable when worn, do not cause a sense of discomfort when worn, and do not give a feeling of being worn have been desired. In view of such demands, various proposals have been made to thin the absorber. For example, various proposals have been made for absorbent sheets including two hydrophilic nonwoven fabrics and SAP fixed between them by a hot melt adhesive.

[0004] Patent Document 1 discloses a urine collection pad that includes a surface layer (top sheet), an absorption layer, and a bottom layer (back sheet) provided in this order from the wearer's skin side to the non-skin side. The absorption layer has, in order from the wearer's skin side to the non-skin side, a perforated film layer made of polyethylene or the like, an upper adhesion layer, a core layer, and a lower adhesion layer. The perforated film layer is located between the top sheet and the core layer, the lower adhesion layer is located between the core layer and the bottom layer, and a superabsorbent resin is filled between the upper adhesion layer and the lower adhesion layer to form the core layer (Claims 1 to 4, Claim 6). According to Patent Document 1, it is described that a urine collection pad that prevents leakage of body fluids and has excellent wearing comfort is provided (paragraph 0018).

[0005] Patent Document 2 discloses an absorbent sheet as an absorber that includes a first sheet, a second sheet disposed opposite to the first sheet, and SAP disposed between the first sheet and the second sheet. The first sheet has an adhesive-coated surface on the surface facing the second sheet, the second sheet has an adhesive-coated surface on the surface facing the first sheet, SAP is intermittently adhered in a stripe shape in the width direction to the adhesive-coated surface of the first sheet and / or the second sheet, and both sides in the width direction are sealed by adhesion of the adhesive-coated surfaces of the first sheet and the second sheet to each other.

Prior Art Documents

Patent Documents

[0006]

Patent Document 1

Patent Document 2

Summary of the Invention

Problems to be Solved by the Invention

[0007] Although the pad product described in Patent Document 1 is relatively excellent in preventing liquid return such as wet back and absorption speed, it cannot be said that it has a sufficient effect in improving body fluid diffusibility and absorption performance. Further, Patent Document 1 describes the use of a core layer (Claim 6) in which a superabsorbent resin is filled between an upper adhering layer and a lower adhering layer as an absorber, and the core layer does not contain absorbent fibers such as fluff pulp like a general absorbent sheet. However, since Patent Document 1 does not clarify a specific method of filling the superabsorbent resin between the upper adhering layer and the lower adhering layer, it cannot be said that the core layer contributes to the thinning of the absorber.

[0008] Although the absorbent sheet described in Patent Document 2 is thin, compared with a conventional fluff absorber, when SAP absorbs and swells body fluids such as urine discharged first and causes gel blocking, blocking the passage of body fluids, there is a problem that when body fluids are discharged for the second time and later, the body fluid absorption speed and the body fluid absorption amount are significantly reduced. A conventional absorbent sheet in which SAP is simply fixed with a hot melt adhesive between two hydrophilic non-woven fabrics as described in Patent Document 2 cannot meet the requirements for multiple body fluid absorptions in current absorbent articles.

[0009] Furthermore, in a conventional absorbent sheet, since SAP is densely arranged, there is a problem that the absorbent article itself becomes hard and the wearing feeling deteriorates. Also, in a non-woven fabric derived from a plastic-based resin constituting the absorbent sheet, since there is no function of instantaneously receiving body fluids until SAP starts to absorb body fluids, the first body fluids cannot be absorbed, and there is also a problem of body fluid leakage and liquid return.

[0010] An object of the present invention is to provide an absorbent article provided with a thin absorbent sheet that is excellent in absorption speed and absorption amount even when absorbing body fluids multiple times, prevents body fluid leakage and liquid return, and is flexible and has a good wearing feeling.

Means for Solving the Problems

[0011] As a result of intensive research to solve the above problems, the inventors of the present invention have found that an absorbent sheet is formed into a predetermined multilayer structure to ensure its thinness and the amount of body fluid absorption, and by arranging a pulp sheet on the outermost non-skin side to prevent liquid return, and by providing embossing grooves reaching from the skin-side surface of the absorbent sheet to the pulp sheet in a predetermined planar shape on the skin-side surface of the absorbent sheet, a desired absorbent article can be obtained, and thus the present invention has been completed. That is, the present invention relates to the following absorbent articles.

[0012] (1) An absorbent article comprising a liquid-permeable topsheet, a liquid-impermeable backsheet, and an absorber disposed between them, wherein the absorber has an absorbent sheet, the absorbent sheet is formed by laminating, in order from the skin side of the wearer, a first hydrophilic nonwoven fabric, a first superabsorbent polymer layer, a second hydrophilic nonwoven fabric, a second superabsorbent polymer layer, and a pulp sheet for temporarily holding body fluid, the absorbent sheet has embossing grooves reaching from its skin-side surface to the skin-side surface of the pulp sheet, the embossing grooves are a first embossing groove extending in the longitudinal direction at the center in the width direction of the skin-side surface of the absorbent sheet, and a second embossing groove provided in a quadrangular shape in plan view on the skin-side surface of the absorbent sheet, with each vertex of the apex angles facing the longitudinal direction of the absorbent sheet located on the first embossing groove, (2) The absorbent article according to (1) above, wherein the absorbent sheet further includes a third hydrophilic nonwoven fabric and a third superabsorbent polymer layer from the skin side of the wearer between the second superabsorbent polymer layer and the pulp sheet. (3) The absorbent article according to (1) or (2) above, wherein the quadrangle is a rhombus. (4) The absorbent article according to any one of (1) to (3) above, wherein a plurality of the second embossing grooves are arranged in the longitudinal direction of the absorbent sheet. (5) The absorbent article according to (4) above, wherein the distance between one of the second embossing grooves and another adjacent second embossing groove is 0 mm or 0 mm or more and 20 mm or less. (6) When setting a virtual figure with the minimum area that encloses the embossed groove and has a similar relationship to the planar shape of the absorbent sheet, the distance between the edge of the virtual figure and the edge of the absorbent sheet is 0 mm or 0 mm or more and 3 mm or less, the absorbent article according to any one of (1) to (5) above. (7) In the width direction of the absorbent sheet, the minimum distance from one end in the width direction of the first embossed groove to the tip in the width direction of the second embossed groove is 3 mm or more and 8 mm or less, the absorbent article according to any one of (1) to (6) above. (8) In the second embossed groove, the angles of the two apex angles of the quadrilateral facing the width direction of the absorbent sheet are 50° or more and 90° or less, the absorbent article according to any one of (1) to (7) above. (9) The thickness of the absorbent sheet is 0.5 mm or more and 5 mm or less, the absorbent article according to any one of (1) to (8) above. (10) The first, second, and third hydrophilic nonwoven fabrics each have a basis weight of 10 g / m 2 or more and 40 g / m 2 or less, and a thickness of 0.05 mm or more and 0.3 mm or less, the absorbent article according to any one of (1) to (9) above. (11) The pulp sheet has a basis weight of 10 g / m 2 or more and 30 g / m 2 or less, and a thickness of 0.05 mm or more and 0.2 mm or less, the absorbent article according to any one of (1) to (10) above. (12) The pulp sheet is a tissue in which cellulose fibers are entangled, the absorbent article according to any one of (1) to (11) above.

Advantages of the Invention

[0013] According to the present invention, there is provided an absorbent article including a thin absorbent sheet that is excellent in absorption speed and absorption amount even when absorbing body fluid multiple times, prevents body fluid leakage and liquid return, and is flexible and has a good feeling of wearing.

Brief Description of the Drawings

[0014]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Mode for Carrying Out the Invention

[0015] In this specification, the wearing of the absorbent article 50 means the state of being worn on the body of the wearer regardless of before and after body fluid absorption. The longitudinal direction of the absorbent article 50 is the direction indicated by Y in the figure, which extends front and rear through the crotch portion of the wearer when the absorbent article 50 is worn. The width direction is the direction indicated by X in the figure, which is substantially orthogonal to the longitudinal direction. The thickness direction is the direction indicated by Z in the figure in which each component member is laminated. The skin side surface (hereinafter also referred to as the "skin side surface") of the absorbent article 50 and each of its component members is the surface that contacts the skin of the wearer or faces the skin, and the non-skin side surface (hereinafter also referred to as the "non-skin side surface") is the surface that contacts the clothing of the wearer or faces the clothing. Body fluid means a liquid discharged from the body to the outside, such as urine, blood, and moisture in soft feces.

[0016] <Absorbent Article> Hereinafter, the absorbent article 50 according to the present embodiment will be described with reference to the drawings. FIGS. 1 to 2 show the absorbent article 50. FIGS. 3 and 4 show the absorbent sheet precursors 20A and 25A before the embossing grooves 15 are formed. FIGS. 5 and 6 show the embossing grooves 15 in the absorbent sheet. Each figure does not define the shape, size relationship, etc. of the absorbent article 50 and each component member.

[0017] The absorbent article 50 of the present embodiment can be used as various absorbent articles for babies, adults, and the elderly. For example, pad products such as light incontinence pads, light incontinence liners, urine absorbent pads, sanitary napkins, etc., paper diaper products such as panty-type paper diapers, tape-fastened paper diapers, etc. can be mentioned. Various paper diapers as the outer and the absorbent article 50 as the inner may be combined. The dimension L 50 (FIG. 1), and the dimension W 50 (FIG. 1) are not particularly limited. For example, L 50 is in the range of 100 mm or more and 800 mm or less, and W 50 is in the range of 50 mm or more and 500 mm or less. When the dimensions of the absorbent article 50 are adjusted within the above ranges, absorbent articles in various forms can be easily obtained.

[0018] The absorbent article 50 shown in FIGS. 1 and 2 includes a liquid-permeable topsheet 10 located on the skin side, a liquid-impermeable backsheet 30 disposed opposite to the topsheet 10 and located on the non-skin side, an absorber 20 disposed between the topsheet 10 and the backsheet 30, a second sheet 60 disposed between the topsheet 10 and the absorber 20, and a pair of three-dimensional gathers 40 provided on the skin-side surface of the topsheet 10. The absorber 20 is an absorbent sheet formed by laminating, in order from the skin side of the wearer, a first hydrophilic nonwoven fabric 21, a first superabsorbent polymer layer (hereinafter also referred to as "SAP layer") 23, a second hydrophilic nonwoven fabric 21, a second SAP layer 23, and a pulp sheet 22 (FIG. 3), and embossing grooves 15 reaching from the skin-side surface of the absorbent sheet to the surface of the pulp sheet 22 are formed in a predetermined planar shape.

[0019] According to the present embodiment, for example, the following excellent effects can be obtained. First, by configuring the absorbent sheet by stacking the first hydrophilic nonwoven fabric 21, the first SAP layer 23, the second hydrophilic nonwoven fabric 21, the second SAP layer 23, and the pulp sheet 22, or by stacking the first hydrophilic nonwoven fabric 21, the first SAP layer 23, the second hydrophilic nonwoven fabric 21, the second SAP layer 23, the third hydrophilic nonwoven fabric 21, the third SAP layer 23, and the pulp sheet 22, while ensuring a body fluid absorption amount capable of coping with multiple times of body fluid absorption, the thinness which is an advantage of the absorbent sheet is maintained. Second, by providing a plurality of thin layers of the SAP layer 23, while preventing gel blocking for each layer, the body fluid absorption ability is improved, the decrease in the absorption rate is suppressed, and the hardness caused by the superabsorbent polymer 12 in the absorbent sheet is prevented from occurring, thereby improving the wearing feeling of the absorbent article 50. Third, by disposing the pulp sheet 22, which temporarily stores the body fluid until the superabsorbent polymer 12 starts to absorb the body fluid, on the outermost side of the absorbent sheet on the non-skin side, body fluid leakage and liquid return are prevented. Note that such a function of the pulp sheet 22 was found by the research of the present inventors. Fourth, by providing the embossing grooves 15 having a predetermined planar shape on the skin-side surface of the absorbent sheet and reaching the skin-side surface of the pulp sheet 22 and / or the vicinity thereof from the skin-side surface of the absorbent sheet, the body fluid diffusibility of the entire absorbent sheet (absorbent body 20) is remarkably improved, and until the end of use of the absorbent article 50, the body fluid absorption rate and the body fluid absorption amount are maintained at a high level, flexibility is imparted to the absorbent sheet, and the wearing feeling of the absorbent article 50 is improved. The absorbent article 50 of the present embodiment exhibits excellent functions by the synergistic action of the first to fourth configurations.

[0020] The absorbent article 50 of the present embodiment has a top sheet 10, an absorber 20, and a back sheet 30 as basic constituent units. For example, various known modifications such as the arrangement of the three-dimensional gathers 40 as described above and the arrangement of the second sheet 60 between the top sheet 10 and the absorber 20 can be added. Hereinafter, the constituent members of the absorbent article 50 of the present embodiment will be described in more detail in the order of the top sheet 10, the second sheet 60, the absorber (absorbent sheet) 20, the back sheet 30, and the three-dimensional gathers 40.

[0021] <Top sheet> The top sheet 10 is a liquid-permeable sheet-like base material that quickly passes body fluid toward the absorber 20 and diffuses the body fluid in the plane direction of the absorber 20. The top sheet 10 preferably has a soft touch and does not irritate the skin so that it may directly contact the skin of the wearer. Examples of the base material include a hydrophilic sheet, a composite nonwoven fabric that is a laminate of the same or different hydrophilic sheets, an apertured film such as an apertured polyethylene film, a polyethylene foam, a foamed film such as a urethane foam, and the like. Examples of the hydrophilic sheet include an air-through nonwoven fabric, a thermal-bonded nonwoven fabric, a spunlace nonwoven fabric, a spunbond nonwoven fabric, etc. made of synthetic fibers such as polypropylene and polyethylene, regenerated fibers such as rayon, and natural fibers such as cotton. Among these, each nonwoven fabric is preferable.

[0022] From the viewpoint of improving liquid permeability, the top sheet 10 may be embossed or perforated on the surface. From the viewpoint of reducing irritation to the skin, the top sheet 10 may contain one or more of a lotion, an antioxidant, an anti-inflammatory component, a pH adjuster, an antibacterial agent, a moisturizing agent, and the like. The basis weight of the top sheet 10 is, for example, 15 g / m 2 ) or more and 40 g / m 2 within the following range. The shape of the top sheet 10 is not particularly limited, and any shape that covers part or all of the absorber 20 and is necessary to guide body fluid to the absorber 20 without leakage is acceptable.

[0023] <Second Sheet> The second sheet 60 is disposed on the non-skin side of the top sheet 10, more specifically, between the top sheet 10 and the absorber 20. By disposing the second sheet 60, the cushioning property is increased, the wearing feeling and the fitting feeling of the absorbent article 50 are improved, and the body fluid that has passed through the top sheet 10 can be diffused almost uniformly over the entire absorber 20.

[0024] The base material of the second sheet 60 is, for example, a bulky nonwoven fabric having a higher body fluid permeation rate than the top sheet 10 and quickly diffusing the body fluid to the absorber 20. As the nonwoven fabric, an air-through nonwoven fabric, a spunbond nonwoven fabric, etc. are preferable. The thickness of the second sheet 60 is, for example, in the range of 0.1 mm or more and 4 mm or less, and its basis weight is, for example, 20 g / m 2 to 60 g / m 2 or less, or in the range of 22 g / m 2 to 37 g / m 2 or less. If the thickness is less than 0.1 mm, or the basis weight is less than 20 g / m 2 or greater than 60 g / m 2 the diffusion of the body fluid to the entire skin-side surface of the absorber 20 becomes insufficient, and the wearing feeling of the absorbent article 50 tends to decrease. Further, the shape of the second sheet 60 is not particularly limited, but in a preferred embodiment, any shape that can completely cover the surface of the absorber 20 may be used.

[0025] <Absorber> The absorber 20 has a dimension (maximum length) L in its longitudinal direction 20 (FIG. 1) that is, for example, in the range of 100 mm or more and 800 mm or less, in the range of 150 mm or more and 500 mm or less, or in the range of 270 mm or more and 500 mm or less. The dimension (maximum width) W in the width direction of the absorber 20 20(FIG. 1) is, for example, in the range of 50 mm or more and 500 mm or less, in the range of 60 mm or more and 400 mm or less, or in the range of 70 mm or more and 105 mm or less. Further, when the planar shape of the absorber 20 is an hourglass shape, the longitudinal dimension is in the range of 180 mm or more and 800 mm or less, the widthwise dimensions of the front part and the rear part that respectively contact the abdomen and the back of the wearer are both in the range of 60 mm or more and 400 mm or less, and the widthwise dimension of the central part that contacts the crotch part of the wearer is in the range of 90 mm or more and 250 mm or less. Examples of the planar shape of the absorber 20 include an hourglass shape, an I-shape, a rectangle, a rounded rectangle with rounded corners, an ellipse, and the like.

[0026] The absorber 20 of the present embodiment is configured to include an absorbent sheet. Examples of the absorbent sheet include those in which emboss grooves 15 are formed on the skin side surface of the absorbent sheet precursor 20A shown in FIG. 3, those in which emboss grooves 15 are formed on the skin side surface of the absorbent sheet precursor 25A shown in FIG. 4, and the like. The emboss grooves 15 are groove portions that reach the skin side surface and / or the vicinity thereof of the pulp sheet 22 located on the most non-skin side of the absorbent sheet from the skin side surface of the absorbent sheet, and the details thereof will be described later.

[0027] (Absorbent sheet) The absorbent sheet precursor 20A shown in FIG. 3 is an absorbent sheet formed by laminating, in order from the skin side of the wearer, a first hydrophilic nonwoven fabric 21, a first SAP layer 23, a second hydrophilic nonwoven fabric 21, a second SAP layer 23, and a pulp sheet 22. Further, the absorbent sheet precursor 25A shown in FIG. 4 is an absorbent sheet formed by laminating, in order from the skin side of the wearer, a first hydrophilic nonwoven fabric 21, a first SAP layer 23, a second hydrophilic nonwoven fabric 21, a second SAP layer 23, a third hydrophilic nonwoven fabric 21, a third SAP layer 23, and a pulp sheet 22. The thickness of the absorbent sheet (absorber 20) in which the emboss grooves 15 are formed in the absorbent sheet precursors 20A and 25A is, for example, in the range of 0.5 mm or more and 5 mm or less. The superabsorbent polymer 12 is fixed in the first, second, and third SAP layers 23 by, for example, a hot melt adhesive.

[0028] (Hydrophilic nonwoven fabric) The first, second, and third hydrophilic nonwoven fabrics 21 diffuse body fluids, for example, in the plane direction and the thickness direction of the absorber 20. As the hydrophilic nonwoven fabric 21, a hydrophilic nonwoven fabric excellent in the diffusibility of body fluids can be used without particular limitation. For example, an air-through nonwoven fabric, a spunbond nonwoven fabric, etc. containing one or more kinds of fibers made of synthetic resins such as polyethylene, polypropylene, and polyester can be mentioned. Among these, from the viewpoint of thinning the absorbent sheet or the absorbent sheets 20A and 25A, a spunbond nonwoven fabric is more preferable. The basis weight of the hydrophilic nonwoven fabric 21 is, for example, 10 g / m 2 or more and 40 g / m 2 or less. The thickness of the hydrophilic nonwoven fabric 21 is, for example, in the range of 0.05 mm or more and 0.3 mm or less. Note that the same kind or different kinds of hydrophilic nonwoven fabrics can be used for the first, second, and third hydrophilic nonwoven fabrics 21.

[0029] (Pulp sheet) The pulp sheet 22 is located on the outermost non-skin side of the absorbent sheet or the absorbent sheets 20A and 25A. For example, it supports the second or third SAP layer 23 and temporarily stores and holds body fluids when body fluids are discharged, preventing the occurrence of body fluid leakage, liquid return, etc. Since the pulp sheet 22 holds body fluids faster than the superabsorbent polymer 12 absorbs body fluids, when the superabsorbent polymer 12 starts to absorb body fluids, the body fluids held in the pulp sheet 22 are absorbed by the superabsorbent polymer 12. The pulp sheet 22 is not particularly limited as long as it is a sheet containing pulp fibers (cellulose fibers). For example, crepe paper made of cellulose fibers, crepe paper containing a wet strength agent, tissue, tissue intertwined with cellulose fibers, etc. can be mentioned. From the viewpoint of fully exerting the above functions of the pulp sheet 22, the basis weight of the pulp sheet 22 is, for example, 10 g / m 2 or more and 30 g / m 2 or more, and the thickness is, for example, in the range of 0.05 mm or more and 0.2 mm or less.

[0030] (Superabsorbent polymer) As the superabsorbent polymer 12 used in each of the first, second, and third SAP layers 23, there is no particular limitation as long as it can absorb body fluids and prevent backflow, and examples include polyacrylate salts, polyaspartate salts, (starch-acrylic acid) graft copolymers, (acrylic acid-vinyl alcohol) copolymers, (isobutylene-maleic anhydride) copolymers, and saponified products thereof. Among these, from the perspective of the absorption amount per unit weight, polyacrylate salts are preferred, alkali metal polyacrylate salts are more preferred, and sodium polyacrylate is even more preferred. The superabsorbent polymer 12 can be used alone or in combination of two or more kinds.

[0031] 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 perspective of ease of handling, etc. At this time, by avoiding the use of the superabsorbent polymer 12 in the form of fine powder with poor fluidity as a powder, and using the superabsorbent polymer 12 having a median particle size, the basic performance related to absorption can be enhanced, and the rough touch generated when the absorber 20 hardens after absorbing body fluids can be reduced. 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.

[0032] The basis weight of the superabsorbent polymer 12 in each of the first, second, and third SAP layers 23 is, for example, 150 g / m 2 or more and 500 g / m 2 or less, or 200 g / m 2 or more and 400 g / m 2 or less, from the perspectives of preventing the occurrence of gel blocking, absorbing body fluids by the superabsorbent polymer 12, and alleviating the rough feeling after hardening. By setting the basis weight of the SAP within the above numerical range, gel blocking in the first, second, and third SAP layers 23 can be prevented, and the absorber 20 (absorbent sheet) can be made to have a soft touch. Further, the thickness of each of the first, second, and third SAP layers 23 is, for example, in the range of 0.5 mm or more and 10.0 mm or less, or in the range of 0.5 mm or more and 6.0 mm or less. Note that the basis weight and thickness of the first, second, and third SAP layers 23 may be the same or different.

[0033] As the hot-melt adhesive used for fixing the superabsorbent polymer 12 in the first, second, and third SAP layers 23, those having a melting point of 100°C or higher and 180°C or lower can be used without particular limitation. For example, synthetic rubber-based hot-melt adhesives such as styrene-butadiene-styrene copolymers and styrene-isoprene-styrene copolymers, and olefin-based hot-melt adhesives such as ethylene-vinyl acetate copolymers can be mentioned. As the application method of the hot-melt adhesive, known methods such as the curtain coating method and the spiral method for applying the molten hot-melt adhesive from a nozzle in a non-contact manner, and the slot method for applying it in a contact manner can be used. The content of the hot-melt adhesive is, from the viewpoint of not impairing the absorbency of the superabsorbent polymer 12 and the feel on the skin during wearing, for example, 10 g / m 2 Is in the following range.

[0034] <Method for manufacturing absorbent sheet precursor> The absorbent sheet precursor 20A can be manufactured according to a known method. As the manufacturing method, for example, a first step of applying a hot-melt adhesive to the non-skin side surface of the first hydrophilic nonwoven fabric 21 and further spraying a predetermined amount of the superabsorbent polymer 12 to form the first SAP layer 23, and a second step of overlapping the second hydrophilic nonwoven fabric 21 on the first SAP layer 23 (non-skin side surface) and forming the second SAP layer 23 in the same manner as in the first step on the non-skin side surface of the second hydrophilic nonwoven fabric, and a third step of overlapping the pulp sheet 22 on the second SAP layer 23 to obtain the absorbent sheet precursor 20A. The absorbent sheet precursor 20A may be subjected to a pressure treatment or a pressure heating treatment as necessary. By embossing the absorbent sheet precursor 20A, the absorbent sheet used as the absorber 20 in the present embodiment can be obtained. The absorbent sheet precursor 25A can also be produced in the same manner.

[0035] (Embossing groove) As shown in FIGS. 5 and 6, the absorber 20 (absorbent sheet) of the present embodiment has embossing grooves 15 in a predetermined pattern in plan view, which are grooves reaching the skin-side surface of the pulp sheet 22 and / or the vicinity thereof from the skin-side surface of the absorber. By providing the embossing grooves 15, the liquid diffusion property in the absorber 20 is greatly improved, and further flexibility is imparted to the absorber 20, resulting in an absorbent article 50 having excellent wearing comfort and fitting feeling. The embossing grooves 15 include a first embossing groove 16 extending in the longitudinal direction at the center in the width direction of the skin-side surface of the absorbent sheet, and a second embossing groove 17 provided in a square shape in plan view on the skin-side surface of the absorbent sheet, with each vertex of the apex angles facing the longitudinal direction of the absorbent sheet being located on the first embossing groove. In the X1-X1 cross section of FIG. 5, only the first embossing groove 16 can be confirmed as shown in FIG. 6(a), and in the X2-X2 cross section of FIG. 5, it can be confirmed that the second embossing grooves 17 are arranged on both sides in the width direction of the first embossing groove 16 as shown in FIG. 6(b). The embossing grooves 15 can be formed on the skin-side surface of the absorber 20 by using, for example, heat embossing, ultrasonic embossing, high-frequency embossing, or the like.

[0036] The quadrilateral, which is the shape of the second embossing groove 17 in plan view, is a figure surrounded by four lines of the same length or different lengths, preferably straight lines. The angle formed by two adjacent lines is called the apex angle, and the point where two adjacent lines meet is called the vertex. A quadrilateral has two apex angles facing one direction and two apex angles facing a direction intersecting with respect to one direction. The quadrilateral is not particularly limited as long as it satisfies the above-mentioned definition, and examples thereof include a rhombus, a square, a rectangle, a parallelogram, and the like.

[0037] In the present embodiment, the width dimension in the width direction of the opening of the first embossing groove 16 (hereinafter also simply referred to as the "width dimension of the first embossing groove 16") W3 is formed to be slightly larger or the same width as the width dimension in the width direction of the opening of the second embossing groove 17 (hereinafter also simply referred to as the "width dimension of the second embossing groove 17"). For example, the width dimension W3 (FIG. 5) of the first embossing groove 16 is in the range of 3 mm or more and 8 mm or less, and the width dimension of the second embossing groove 17 is in the range of 3 mm or more and 8 mm or less.

[0038] Further, in the present embodiment, a plurality of second embossing grooves 17 are arranged in the longitudinal direction of the absorbent sheet. That is, three substantially diamond-shaped second embossing grooves 17 are arranged in the longitudinal direction with the vertices of the apex angles facing the longitudinal direction of the absorbent sheet placed on the first embossing groove 16. The number of the second embossing grooves 17 is not limited to the present embodiment and may be one or a plurality. In a preferred embodiment, the interval V (FIG. 5) between one second embossing groove 17 and another adjacent second embossing groove 17 may be 0 mm, and when they are separated from each other, for example, it is in the range of 0 mm or more and 20 mm or less. When the interval V is larger than 20 mm, the second embossing grooves 17 are too far apart in the longitudinal direction, and there is a tendency that the improvement of the body fluid diffusibility is not sufficient.

[0039] In another preferred embodiment of the present invention, two horizontal lines P1 and P2 extending in the width direction at both longitudinal ends of the first embossing portion 16 are assumed, and two vertical lines Q1 and Q2 extending in the longitudinal direction at the outermost points in the width direction on both sides of the second embossing portion 17 are assumed (FIG. 5). The virtual figure surrounded by the two horizontal lines P1 and P2 and the two vertical lines Q1 and Q2 is a figure with the smallest area that encloses the entire embossing groove 15 and has a similar relationship with the planar view shape of the absorbent sheet. At this time, the distances between the edges of the virtual figure and the edges of the absorbent sheet are shown as the longitudinal distances L1 and L2 and the width distances W1 and W2 in FIG. 5, but all of these are the same and may be 0 mm (when the virtual figure coincides with the planar view shape of the absorbent sheet), and when there is a distance, for example, it is in the range of 0 mm or more and 3 mm or less. According to the present embodiment, the discharged body fluid is smoothly absorbed by the absorber 20 through the embossing portion 15. When the distance between the edge of the virtual figure and the edge of the absorbent sheet exceeds 3 mm, a part of the body fluid diffused from the embossing portion 15 is less likely to be instantaneously absorbed by the absorber 20, and there is a tendency that it overflows on the skin-side surface of the topsheet 10 and leakage is likely to occur. Note that the present invention is not limited to this embodiment, and L1, L2, W1, and W2 may be individually varied, for example, in the range of 0 mm or more and 3 mm or less.

[0040] In another preferred embodiment, in the width direction of the absorbent sheet, the minimum distance W3 (width, FIG. 5) from one end in the width direction to the other end in the width direction of the first embossed groove 16 is, for example, in the range of 3 mm or more and 8 mm or less. According to this embodiment, the effect of improving the body fluid diffusibility due to the formation of the embossed groove 15 is stably exhibited. When the minimum distance W3 (width) is less than 3 mm, the body fluid diffusibility tends to be insufficient. When the minimum distance W3 (width) exceeds 8 mm, a thick body fluid flow is generated, which tends to cause leakage.

[0041] In still another preferred embodiment, in the three second embossed grooves 17 arranged in the longitudinal direction of the absorbent sheet, the two apex angles of the quadrangle in plan view of each second embossed groove 17 that face the width direction of the absorbent sheet are the same angle. At this time, the angles α, β, γ (FIG. 5) of the two apex angles are each 50° or more and 90° or less. According to this embodiment, the effect of improving the body fluid diffusibility due to the formation of the second embossed groove 17 is stably exhibited. When the angles α, β, γ are less than 50° and exceed 90°, a part of the superabsorbent polymer 12 that has absorbed and swollen with body fluid causes gel blocking, partially fills the second embossed groove 17, and eliminates the second embossed groove 17, and the body fluid diffusibility tends to decrease.

[0042] <Carrier sheet> In this embodiment, the absorber 20 may be wrapped with a carrier sheet (not shown). The carrier sheet is a hydrophilic sheet that wraps the absorber 20 entirely or partially. For example, the absorber 20 is placed at the center in the width direction of the carrier sheet, and after adhesively bonding the carrier sheet and the absorber 20 with a hot melt adhesive or the like as necessary, both end portions in the width direction of the carrier sheet are overlapped on the skin side of the absorber 20 and adhesively bonded with a hot melt adhesive or the like as necessary, whereby the absorber 20 C-folded with the carrier sheet can be obtained. As the carrier sheet, any hydrophilic sheet commonly used in this field can be used. Examples thereof include hydrophilic nonwoven fabrics such as thermal bonded nonwoven fabric, spunbond nonwoven fabric, airlaid nonwoven fabric, air-through nonwoven fabric, pulp-containing nonwoven fabric, tissue paper, absorbent paper, and the like. Among the hydrophilic nonwoven fabrics, hydrophilic nonwoven fabrics such as thermal bonded nonwoven fabric, spunbond nonwoven fabric, air-through nonwoven fabric, and pulp-containing nonwoven fabric are more preferable, and air-through nonwoven fabric, pulp-containing nonwoven fabric, spunbond nonwoven fabric, and the like are even more preferable. Further, the thickness of the carrier sheet is, for example, in the range of 0.10 mm or more and 0.25 mm or less, and the basis weight is, for example, 5 g / m 2 or more and 40 g / m 2 or less.

[0043] <Backsheet> The backsheet 30 may be formed using a liquid-impermeable base material that prevents the body fluid held by the absorber 20 from wetting the wearer's clothing. Examples of the base material include a resin film, a composite sheet that is a laminate of a resin film and a nonwoven fabric, and the like. The nonwoven fabric used for the composite sheet is not particularly limited in terms of manufacturing method. Examples thereof include single-layer nonwoven fabrics such as spunbond nonwoven fabric and meltblown nonwoven fabric, composite nonwoven fabrics such as spunbond nonwoven fabric / meltblown nonwoven fabric laminate, spunbond nonwoven fabric / meltblown nonwoven fabric / spunbond nonwoven fabric laminate, and these composite materials. Examples of the resin film include polyester, polyvinyl alcohol, polyethylene, polypropylene, a composite film of polyethylene and polypropylene, and the like.

[0044] The basis weight of the backsheet 30 is, for example, 15 g / m from the viewpoints of strength and processability2 60 g / m or less 2 It is within the following range. Also, in order to prevent stuffiness when worn, it is preferable to provide the back sheet 30 with air permeability. In order to provide the back sheet 30 with air permeability, for example, a filler may be blended in the resin film of the base material, or the back sheet 30 may be embossed. As the filler, calcium carbonate can be mentioned, and the blending method can be carried out without limitation by a known method.

[0045] <Three-dimensional gather> The three-dimensional gather 40 is fixed to the skin side surface of the top sheet 10 along the longitudinal direction of the absorbent article 50 near both ends in the width direction of the absorbent article 50, for example, to prevent lateral leakage of body fluid excreted by the wearer of the absorbent article 50. The three-dimensional gather 40 includes an elastic stretch member 40a and a water-repellent and / or waterproof sheet member 40b.

[0046] The elastic stretch member 40a is disposed along the longitudinal direction near the free end (the other end) of the sheet member 40b, imparts standing property to the free end, and enables the free end and its vicinity region of the sheet member 40b to be deformed according to the body shape of the wearer. In this embodiment, one end (fixed end) in the width direction of the sheet member 40b is fixed near both ends in the width direction of the skin side surface of the back sheet 30, the middle part in the width direction is fixed near both ends in the width direction of the skin side surface of the top sheet 10, and the other end in the width direction is a free end having standing 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, and examples include the non-skin side surface of the back sheet 30, the skin side surface or the non-skin side surface near both ends in the width direction of the joined body of all or part of the edges of the top sheet 10 and the back sheet 30 that houses the absorber 20 inside, and near both ends in the width direction of the skin side surface of the top sheet 10.

[0047] The sheet member 40b is a sheet having water repellency and / or waterproofness, and is composed of, for example, a non-woven fabric. As the non-woven fabric for the first sheet member, a water-repellent and / or waterproof (liquid-impermeable) non-woven fabric formed of hydrophobic fibers can be used without particular limitation. Examples thereof include a spunbond non-woven fabric, a meltblown non-woven fabric, and a composite non-woven fabric (SMS non-woven fabric) which is a laminate of a spunbond non-woven fabric / meltblown non-woven fabric / spunbond non-woven fabric. The basis weight of the sheet member 40b is, for example, 13 g / m 2 to 20 g / m 2 or less. As the elastic stretch member 40a, for example, a thread-like, string-like, or belt-like member made of natural rubber, synthetic rubber, polyurethane, or the like can be appropriately used.

[0048] <Method for manufacturing an absorbent article> The absorbent article 50 can be manufactured by a known manufacturing method. For example, a step of accommodating the absorbent body 20 between the top sheet 10 and the second sheet 60 and the back sheet 30, and a step of fixing a part or the entire circumference of the edge of the top sheet 10 and the edge of the back sheet 30 using a hot melt adhesive, heat embossing, ultrasonic embossing, high frequency embossing, or the like, and a step of installing the three-dimensional gathers 40 at predetermined positions on the back sheet 30 and the top sheet 10 are included. In the absorbent article 50, leg gathers, waist gathers, side flaps, etc. are appropriately provided as necessary. The thus obtained absorbent article 50 is folded and commercialized.

[0049] As described above, the present invention has been described using the embodiments, but 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 changes or improvements can be made to the above embodiments. Also, it is obvious from the description of the claims that forms with such changes or improvements can also be included in the technical scope of the present invention.

Examples

[0050] Examples are given below to more specifically explain the present embodiment.

[0051] (Examples 1 to 11 and Comparative Examples 1 to 9) The dimensions and angles of the embossed grooves were changed to obtain the embossed groove patterns shown in Table 1. The embossed grooves were the same as the embossed pattern shown in Fig. 5 except for the dimensions and angles. Next, absorbent sheets of Examples 1 to 11 and Comparative Examples 1 to 9 used as absorbers were produced with the configurations shown in Tables 2 and 3. In Tables 2 and 3, the first sheet refers to the first hydrophilic nonwoven fabric, the second sheet refers to the second hydrophilic nonwoven fabric, and the third sheet refers to a pulp sheet or the like. Also, in Tables 2 and 3, the amount of SAP of 2.0 g per layer of the first SAP layer, the second SAP layer, and the third SAP layer, when converted to basis weight, is approximately 177.7 g / m 2 (=(2.0 g) / ((150 mm × 75 mm) / 1000000)).

[0052] (Production of Absorbent Articles) Using the absorbent sheet obtained above as the absorber, as the liquid-permeable top sheet, an air-through nonwoven fabric (basis weight 25 g / m 2 ) was used, as the second sheet, an air-through nonwoven fabric (basis weight 30 g / m 2 ) was used, as the three-dimensional gathers, a composite nonwoven fabric obtained by laminating a spunbond nonwoven fabric / meltblown nonwoven fabric / spunbond nonwoven fabric (basis weight 15 g / m 2 ) was used, and as the liquid-impermeable back sheet, a breathable polyethylene sheet (basis weight 32 g / m 2 ) was used. When integrating the top sheet, the back sheet, and the absorber, a hot melt adhesive was used to join the top sheet and the upper surface of the absorber, and absorbent articles of Examples 1 to 11 and Comparative Examples 1 to 9 were produced. The dimensions of the absorbent articles were 230 mm in the longitudinal direction and 90 mm in the width direction.

[0053] [Evaluation] The absorbent articles of Examples 1 to 11 and Comparative Examples 1 to 9 obtained above were subjected to the following evaluations. The evaluation results are shown in Tables 2 and 3.

[0054] (Thickness of Absorbent Article) The thickness of the central part of the absorbent article was measured using an ABS Digital Height Gauge (product name: HDS-HC, manufactured by Mitutoyo Corporation). (Absorption rate three - time method) A cylinder with a bottom area of 16.8 cm 2 having a hole with an inner diameter of 19 mm at the center and a measuring jig weighing 755.6 g was placed on the central part of the absorbent article in the longitudinal direction and the central part in the width direction. 20 ml of physiological saline was dropped from above the hole, and the time was measured with the end point being when the liquid was completely sucked into the circumference within the central circle of the jig from the time when the physiological saline contacted the absorbent article (first time). Then, after 3 minutes, the same time was measured (second time), and similarly the third time was measured, and the total value of the three times was obtained. (45 - degree leakage test) A 45 - degree leakage test was conducted to observe the temporary absorption of body fluids. Two acrylic plates of 250 mm×400 mm×8 mm were fixed with one placed horizontally and the other inclined at 45 degrees from the horizontally placed acrylic plate. The absorbent article prepared was attached to the acrylic plate inclined at 45 degrees from the horizontal. 20 mL of physiological saline was poured towards the center of the absorbent body, and it was judged as "○" if no leakage occurred from the lower side of the absorbent article, and "×" if leakage occurred.

[0055]

Table 1

[0056]

Table 2

[0057]

Table 3

[0058] From the results in Table 2, it can be said that the absorbent articles of Examples 1 to 11 have a high absorption rate, good leakage at 45 degrees, no problem in temporary absorption, and are difficult to leak. On the other hand, the absorbent articles of Comparative Examples 1 to 9 in Table 3 had results of slow absorption rate, poor leakage at 45 degrees, or both. Therefore, according to the present embodiment, since gel blocking is less likely to occur, an absorbent article with a high absorption rate and excellent temporary absorption can be obtained.

Explanation of Signs

[0059] 10 Topsheet 12 Superabsorbent Polymer 15 Embossing Groove 16 First Embossing Groove 17 Second Embossing Groove 20 Absorbent Body 21 First, Second, and Third Hydrophilic Nonwoven Fabrics 22 Pulp Sheet 23 First, Second, and Third Superabsorbent Polymer Layers (SAP Layers) 30 Backsheet 40 Three-dimensional Gather 40a Elastic Stretch Member 40b Sheet Member 50 Absorbent Article 60 Second Sheet

Claims

1. An absorbent article comprising a liquid-permeable topsheet, a liquid-impermeable backsheet, and an absorber disposed therebetween, wherein the absorber has an absorbent sheet, the absorbent sheet is formed by laminating, in order from the wearer's skin side, a first hydrophilic nonwoven fabric, a first superabsorbent polymer layer, a second hydrophilic nonwoven fabric, a second superabsorbent polymer layer, and a pulp sheet for temporarily holding body fluid, the pulp sheet is located on the outermost non-skin side of the absorbent sheet, the absorbent sheet has embossed grooves that recess the first hydrophilic nonwoven fabric, the first superabsorbent polymer layer, the second hydrophilic nonwoven fabric, and the second superabsorbent polymer layer from the skin-side surface thereof to reach the skin-side surface of the pulp sheet, the embossed grooves include a first embossed groove extending longitudinally at the center in the width direction of the skin-side surface of the absorbent sheet, and a second embossed groove provided in a quadrangular shape in plan view on the skin-side surface of the absorbent sheet, with each vertex of the apex angles facing the longitudinal direction of the absorbent sheet located on the first embossed groove, the width dimension of the first embossed groove is larger than the width dimension of the second embossed groove, as the first hydrophilic nonwoven fabric and the second hydrophilic nonwoven fabric, at least one of an air-through nonwoven fabric and a spunbond nonwoven fabric containing one or more of fibers made of polyethylene, fibers made of polypropylene, and fibers made of polyester is used, the quadrilateral is a rhombus, a plurality of the second embossed grooves are arranged in the longitudinal direction of the absorbent sheet, the distance between one of the second embossed grooves and another adjacent second embossed groove is 0 mm or 0 mm or more and 20 mm or less, when a virtual figure with the minimum area that encloses the embossed grooves and has a similar relationship to the planar shape of the absorbent sheet is set, the distance between the edge of the virtual figure and the edge of the absorbent sheet is 0 mm or 0 mm or more and 3 mm or less, in the width direction of the absorbent sheet, the minimum distance from one end in the width direction of the first embossed groove to the tip in the width direction of the second embossed groove is 3 mm or more and 8 mm or less, in the second embossed groove, the angles of the two apex angles of the quadrilateral facing the width direction of the absorbent sheet are 50° or more and 90° or less. An absorbent article.

2. The absorbent sheet further includes a third hydrophilic nonwoven fabric and a third superabsorbent polymer layer between the second superabsorbent polymer layer and the pulp sheet, from the side of the wearer's skin. The embossed groove is recessed from the skin-side surface of the absorbent sheet to the non-skin side through the first hydrophilic nonwoven fabric, the first superabsorbent polymer layer, the second hydrophilic nonwoven fabric, the second superabsorbent polymer layer, the third hydrophilic nonwoven fabric, and the third superabsorbent polymer layer to reach the skin-side surface of the pulp sheet. The absorbent article according to claim 1. **Claim 3** The absorbent article according to claim 1 or claim 2, wherein the absorbent sheet has a thickness of 0.5 mm or more and 5 mm or less. **Claim 4** The first, second, and third hydrophilic nonwoven fabrics each have a basis weight of 10 g / m ２ or more and 40 g / m ２ or less, and a thickness of 0.05 mm or more and 0.3 mm or less. The absorbent article according to claim 2. **Claim 5** The pulp sheet has a basis weight of 10 g / m ２ or more and 30 g / m ２ or less, and a thickness of 0.05 mm or more and 0.2 mm or less. The absorbent article according to any one of claims 1 to 4. **Claim 6** The absorbent article according to any one of claims 1 to 5, wherein the pulp sheet is a tissue in which cellulose fibers are entangled.

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