Absorbent article

Abstract

To provide an absorbent article equipped with a thin and flexible absorbent sheet in which neither absorption rate nor absorption quantity decreases in a plurality of absorption, body fluid leakage and liquid return are prevented, and which has good wear feeling.SOLUTION: An absorbent article 50 includes a liquid permeable top sheet 10, a liquid impermeable back sheet 30, and an absorber 20 between them. The absorber 20 has an absorbent sheet. The absorbent sheet layers first hydrophilic non-woven fabric, a first high absorbent polymer layer, second hydrophilic non-woven fabric, a second high absorbent polymer layer, and a pulp sheet from a wearer's skin side. The absorbent sheet has an embossment groove 15 reaching the skin side surface of the pulp sheet from the skin side surface. The embossment groove 15 has: a first embossment groove extending in a longitudinal direction in the center of the width direction on the skin side surface of the absorbent sheet; and a second embossment groove which is provided in a planar view X shape on the skin side surface of the absorbent sheet and in which X intersections are positioned in the first embossment groove.SELECTED DRAWING: Figure 1

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 therebetween. The absorber absorbs and holds the body fluid that has passed through the topsheet, and the backsheet is configured to prevent the body fluid from adhering 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, etc., and paper diaper products such as pant-type paper diapers, tape-fastened paper diapers, etc. 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. Also, the number of people who can walk while wearing absorbent articles is increasing. For this reason, recently, thin absorbent articles that are not conspicuous 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 reduce the thickness of the absorber. Also, regarding absorbent sheets containing two hydrophilic nonwoven fabrics and SAP fixed between them by a hot melt adhesive as a thin absorber, various proposals have been made.

[0004] Patent Document 1 discloses a urine collection pad comprising a surface layer (top sheet), an absorption layer, and a bottom layer (back sheet) provided in this order from the skin side to the non-skin side of the wearer. The absorption layer has, in this order from the skin side to the non-skin side of the wearer, 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, and the lower adhesion layer is located between the core layer and the bottom layer. A high water-absorbing 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 leakage of body fluids is prevented and the wearing feeling is excellent (paragraph 0018).

[0005] Patent Document 2 discloses an absorber including a first sheet, a second sheet disposed opposite to the first sheet, and a SAP disposed between the first sheet and the second sheet. The first sheet has an adhesive-coated surface facing the second sheet, and the second sheet has an adhesive-coated surface facing the first sheet. The 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 between the adhesive-coated surfaces of the first sheet and the second sheet. According to Patent Document 2, it is described that the absorption performance of the absorber is ensured and the width of the absorber can be reduced (paragraph 0012).

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 terms of 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 polymer is filled between an upper attachment layer and a lower attachment layer as an absorber, and the core layer does not contain absorbent fibers such as fluff pulp, similar to a general absorbent sheet. However, since the specific method of filling the superabsorbent polymer between the upper attachment layer and the lower attachment layer is not clear in Patent Document 1, 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, the passage of body fluids is blocked. Therefore, there is a problem that the body fluid absorption speed and the body fluid absorption amount are significantly reduced when body fluids are discharged for the second time and subsequent times. A conventional absorbent sheet in which SAP is simply fixed with a hot melt adhesive between two hydrophilic nonwoven fabrics as described in Patent Document 2 cannot meet the requirements for multiple absorptions of body fluids in current absorbent articles.

[0009] Furthermore, in conventional absorbent sheets, since SAP is densely arranged, there are problems such as the absorbent article itself becoming hard and the wearing feeling deteriorating. In addition, in nonwoven fabrics derived from plastic-based resins that constitute 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 are also problems such as 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 by forming the absorbent sheet into a predetermined multi-layer structure to ensure its thickness and the amount of body fluid absorption, and by disposing the 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 article.

[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 along the center in the width direction of the skin-side surface of the absorbent sheet, and a second embossing groove provided in an X shape in plan view on the skin-side surface of the absorbent sheet, with the intersection of the X shape located in 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 a plurality of the second embossing grooves are arranged in the longitudinal direction of the absorbent sheet. (4) The absorbent article according to (3) above, wherein the distance between one second embossing groove and another adjacent second embossing groove is 0 mm or 0 mm or more and 20 mm or less. (5) 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 (4) above. (6) 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 (5) above. (7) In the second embossed groove, the angle of the X formed by facing the edge in the width direction of the absorbent sheet is 50° or more and 90° or less. The absorbent article according to any one of (1) to (6) above. (8) 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 (7) above. (9) 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 (8) above. (10) 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 (9) above. (11) The pulp sheet is crepe paper containing a wet strength agent. The absorbent article according to any one of (1) to (10) 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 forming the embossment groove 15. FIGS. 5 and 6 show the embossment groove 15. 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 pant-type paper diapers, tape-type paper diapers, etc. may be mentioned. Various paper diapers as the outer and the absorbent article 50 as the inner may be combined. The dimension L in the longitudinal direction of the absorbent article 50 10 (FIG. 1), and the dimension W in the width direction 10 (FIG. 1) are not particularly limited. For example, L 10 is in the range of 100 mm or more and 800 mm or less, and W 10 is in the range of 50 mm or more and 500 mm or less. When the dimensions of the absorbent article 50 are adjusted to 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, a second sheet 60 disposed between the topsheet 10 and the absorbent body 20, an absorbent body 20 disposed between the second sheet 60 and the backsheet 30, and a pair of three-dimensional gathers 40 provided on the skin-side surface of the topsheet 10. The absorbent body 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 23, a second hydrophilic nonwoven fabric 21, a second superabsorbent polymer 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, the absorbent sheet is formed by stacking a first hydrophilic nonwoven fabric 21, a first superabsorbent polymer layer 23, a second hydrophilic nonwoven fabric 21, a second superabsorbent polymer layer 23, and a pulp sheet 22, or by stacking a first hydrophilic nonwoven fabric 21, a first superabsorbent polymer layer 23, a second hydrophilic nonwoven fabric 21, a second superabsorbent polymer layer 23, a third hydrophilic nonwoven fabric 21, a third superabsorbent polymer layer 23, and a pulp sheet 22, thereby maintaining the thinness, which is an advantage of the absorbent sheet. Second, by providing a plurality of thin layers of the superabsorbent polymer layer 23, the gel blocking is prevented for each layer while improving the body fluid absorption ability, suppressing the decrease in the absorption rate, preventing the hardness caused by the superabsorbent polymer 12 from appearing in the absorbent sheet, and 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 absorbing the body fluid, on the outermost side of the absorbent sheet away from the skin, body fluid leakage and liquid return are prevented. Such a function of the pulp sheet 22 was discovered by the research of the present inventors. Fourth, by providing embossing grooves 15 having a predetermined planar shape on the skin-side surface of the absorbent sheet, extending from the skin-side surface of the absorbent sheet to the skin-side surface of the pulp sheet 22, the body fluid diffusibility of the entire absorbent sheet (absorbent body 20) is significantly improved, and until the end of use of the absorbent article 50, the absorption rate and the absorption speed 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 due to 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, and 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 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 allows body fluids to pass through toward the absorber 20 and diffuses the body fluids in the plane direction of the absorber 20. The top sheet 10 preferably has a soft texture 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, a perforated film such as a perforated polyethylene film, a foamed film such as a polyethylene foam or a urethane foam, and the like. Examples of the hydrophilic sheet include an air-through nonwoven fabric, a thermal bond nonwoven fabric, a spunlace nonwoven fabric, a spunbond nonwoven fabric, etc. made of synthetic fibers made of synthetic resins such as polypropylene and polyethylene, regenerated fibers such as rayon, and natural fibers such as cotton. Among these, each nonwoven fabric is preferred.

[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, etc. 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 fluids to the absorber 20 so as not to leak 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 fit and the wearing feeling 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 non-woven fabric having a body fluid permeation rate faster than that of the top sheet 10 and quickly diffusing the body fluid to the absorber 20. As the non-woven fabric, an air-through non-woven fabric, a spunbond non-woven 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 body fluid will not be sufficiently diffused over the entire skin-side surface of the absorber 20, and the wearing feeling of the absorbent article 50 will tend to deteriorate. Further, the shape of the second sheet 60 is not particularly limited, but in a preferred embodiment, it is a shape that can completely cover the surface of the absorber 20.

[0025] <Absorber> The absorber 20 has a dimension (maximum length) L in its longitudinal direction 40 (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 40(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. 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 A and the rear part C that respectively contact the abdomen and 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 B that contacts the crotch 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 one in which embossed grooves 15 are formed on the skin side surface of the absorbent sheet precursor 20A shown in FIG. 3, or one in which embossed grooves 15 are formed on the skin side surface of the absorbent sheet precursor 25A shown in FIG. 4. The embossed grooves 15 are groove portions that reach from the skin side surface of the absorbent sheet to the skin side surface of the pulp sheet 22 located on the most non-skin side 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 superabsorbent polymer layer 23 (hereinafter also referred to as "SAP layer 23"), a second hydrophilic nonwoven fabric 21, a second superabsorbent polymer layer 23, and a pulp sheet 22. 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 superabsorbent polymer layer 23, a second hydrophilic nonwoven fabric 21, a second superabsorbent polymer layer 23, a third hydrophilic nonwoven fabric 21, a third superabsorbent polymer layer 23, and a pulp sheet 22. The thickness of the absorbent sheet 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 superabsorbent polymer layers 23 by, for example, a hot melt adhesive.

[0028] (Hydrophilic nonwoven fabric) The first, second, and third hydrophilic nonwoven fabrics 21 diffuse body fluid in, for example, 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 fluid 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 a synthetic resin such as polyethylene, polypropylene, polyester, etc. 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 side of the absorbent sheet or the absorbent sheets 20A and 25A. For example, it supports the second or third superabsorbent polymer layer 23, and when body fluid is discharged, it temporarily stores and holds the body fluid before the superabsorbent polymer 12 starts to absorb the body fluid, preventing the occurrence of body fluid leakage, liquid return, etc. Since the pulp sheet 22 holds the body fluid faster than the superabsorbent polymer 12 absorbs the body fluid, when the superabsorbent polymer 12 starts to absorb the body fluid, the body fluid held by the pulp sheet 22 is 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, etc. can be mentioned. From the viewpoint of sufficiently exerting the above-mentioned 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. 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. From the perspective of ease of handling, etc., it is preferably used in the form of particles. 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 by the absorber 20 hardening 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 the first, second, and third SAP layers 23 is, from the perspective of preventing the occurrence of gel blocking, for example, 150 g / m 2 or more and 800 g / m 2 or less, or 200 g / m 2 or more and 700 g / m 2 or less. By setting the basis weight of the SAP within the above numerical range, gel blocking in the first, second, and third superabsorbent polymer layers 23 can be prevented, and the absorber 20 (absorbent sheet) can be given a soft touch. Also, the thickness of the first, second, and third superabsorbent polymer 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 non-contact application of the molten hot-melt adhesive from a nozzle, and the slot method for contact application 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 It 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 superabsorbent polymer layer 23, and a second step of overlapping the second hydrophilic nonwoven fabric 21 on the first superabsorbent polymer layer 23 and forming the second superabsorbent polymer layer 23 on the non-skin side surface of the second hydrophilic nonwoven fabric in the same manner as in the first step, and a third step of overlapping the pulp sheet 22 on the second superabsorbent polymer layer 23 to obtain the absorbent sheet precursor 20A can be mentioned. The absorbent sheet precursor 20A may be subjected to a pressure treatment or a pressure-heat 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 be created in the same manner.

[0035] (Embossing groove) As shown in FIGS. 5 and 6, the absorber 20 (absorbent sheet) of the present embodiment has emboss grooves 15 in a predetermined pattern in plan view, which are grooves reaching from the skin-side surface of the absorber 20 to the skin-side surface of the pulp sheet 22. By providing the emboss grooves 15, the diffusibility of body fluids 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 properties. The emboss grooves 15 include a first emboss 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 emboss groove 17 provided in an X shape in plan view on the skin-side surface of the absorbent sheet, with the intersection of the X shape located at the first emboss groove 16. In the X1-X1 cross-section of FIG. 5, only the first emboss 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 emboss grooves 17 are arranged on both sides in the width direction of the first emboss groove 16 as shown in FIG. 6(b). The emboss grooves 15 can be formed on the skin-side surface of the absorber 20, for example, by using heat embossing, ultrasonic embossing, high-frequency embossing, or the like.

[0036] In the present embodiment, the widthwise dimension of the opening of the first emboss groove 16 (hereinafter also simply referred to as the "width dimension of the first emboss groove 16") is formed to be slightly larger than or the same as the widthwise dimension of the opening of the second emboss groove 17 (hereinafter also simply referred to as the "width dimension of the second emboss groove 17"). For example, the width dimension of the first emboss groove 16 is in the range of 3 mm or more and 8 mm or less, and the width dimension of the second emboss groove 17 is in the range of 3 mm or more and 8 mm or less.

[0037] In addition, in the present embodiment, a plurality of second embossing grooves 17 are arranged in the longitudinal direction of the absorbent sheet. That is, three X-shaped second embossing grooves 17 are arranged longitudinally with the intersection of the X placed on the line (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 distance V (Fig. 5) between one second embossing groove 17 and another second embossing groove 17 adjacent thereto 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 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.

[0038] In another preferred embodiment of the present invention, two lines A obtained by extending both longitudinal ends of the first embossing portion 16 in the width direction are assumed, and two lines B obtained by extending the outermost points in the width direction on both sides in the width direction of the second embossing portion 17 in the longitudinal direction are assumed. The virtual figure surrounded by the two lines A and the two lines B 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, and 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 edges of the virtual figure and the edges 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 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.

[0039] In another preferred embodiment, in the width direction of the absorbent sheet, the minimum distance W3 (Fig. 5) from one end in the width direction of the first embossed groove 16 to the tip in the same width direction of the second embossed groove 17 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 liquid diffusion property due to the formation of the embossed groove 15 is stably exhibited. When the minimum distance W3 is less than 3 mm, the liquid diffusion property tends to be insufficient. When the minimum distance W3 exceeds 8 mm, a thick liquid flow is generated, which tends to cause leakage.

[0040] In yet another preferred embodiment, in the second embossed groove 17, the angles α, β, γ (Fig. 5) formed by the "X" of the cross-shaped shape in plan view of the second embossed groove 17 facing the widthwise edge of the absorbent sheet are 50° or more and 90° or less. According to this embodiment, the effect of improving the liquid diffusion property 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°, the superabsorbent polymer 12 that has absorbed and swollen with the liquid causes gel blocking, fills the second embossed groove 17, and the liquid diffusion property tends to decrease. When there are a plurality of second embossed grooves 17 as shown in Fig. 5, the angles α, β, γ may be the same or different.

[0041] <Carrier sheet> In this embodiment, the absorber 20 may be wrapped with a carrier sheet (not shown). The carrier sheet is a hydrophilic sheet and 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 bond 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 bond nonwoven fabric, spunbond nonwoven fabric, air-through nonwoven fabric, pulp-containing nonwoven fabric are more preferable, and air-through nonwoven fabric, pulp-containing nonwoven fabric, spunbond nonwoven fabric 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.

[0042] <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 the manufacturing method. Examples thereof include single-layer nonwoven fabrics such as spunbond nonwoven fabric and meltblown nonwoven fabric, composite nonwoven fabrics such as a spunbond nonwoven fabric / meltblown nonwoven fabric laminate and a 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.

[0043] 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 sweating during wearing, it is preferable to provide the backsheet 30 with air permeability. In order to provide the backsheet 30 with air permeability, for example, a filler may be blended into the resin film of the base material, or the backsheet 30 may be embossed. As the filler, calcium carbonate can be mentioned, and the blending method can be carried out without limitation by known methods.

[0044] <Three-dimensional gathers> The three-dimensional gathers 40 are fixed to the skin side surface of the topsheet 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 fluids excreted by the wearer of the absorbent article 50. The three-dimensional gathers 40 include an elastic stretch member 40a and a water-repellent and / or waterproof sheet member 40b.

[0045] 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 the 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 backsheet 30, the middle part in the width direction is fixed near both ends in the width direction of the skin side surface of the topsheet 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 backsheet 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 topsheet 10 and the backsheet 30 that houses the absorber 20 inside, and near both ends in the width direction of the skin side surface of the topsheet 10.

[0046] The sheet member 40b is a water-repellent and / or waterproof sheet, and is made of, for example, a nonwoven fabric. As the nonwoven fabric for the first sheet member, any water-repellent and / or waterproof (liquid-impermeable) nonwoven fabric made of hydrophobic fibers can be used without any particular limitation, and examples thereof include spunbond nonwoven fabric, meltblown nonwoven fabric, and composite nonwoven fabric (SMS nonwoven fabric) which is a spunbond nonwoven fabric / meltblown nonwoven fabric / spunbond nonwoven fabric laminate. The basis weight of the sheet member 40b is, for example, 13 g / m 2 More than 20g / m 2 The range is as follows: As the elastic stretchable member 40a, for example, thread-, string- or band-shaped members made of natural rubber, synthetic rubber, polyurethane or the like can be appropriately used.

[0047] <Method of manufacturing absorbent articles> The absorbent article 50 can be manufactured by a known manufacturing method, and examples of such manufacturing methods include a process of accommodating the absorbent body 20 between the top sheet 10, the second sheet 60, and the back sheet 30, a process of fixing the edge of the top sheet 10 and the edge of the back sheet 30 partially or entirely around the periphery using a hot melt adhesive, heat embossing, ultrasonic embossing, high frequency embossing, or the like, and a process of providing the three-dimensional gathers 40 at predetermined positions on the back sheet 30 and the top sheet 10. The absorbent article 50 is appropriately provided with leg gathers, waist gathers, side flaps, and the like as necessary. The absorbent article 50 thus obtained is folded to be manufactured.

[0048] 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 described in the above embodiments and examples. It is clear to those skilled in the art that various modifications and improvements can be made to the above embodiments. In addition, it is clear from the description of the claims that forms with such modifications or improvements can also be included in the technical scope of the present invention. EXAMPLES

[0049] The present embodiment will be described more specifically below with reference to examples.

[0050] (Examples 1 to 11 and Comparative Examples 1 to 10) 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 pattern shown in FIG. 5 except for the dimensions and angles. Next, Absorbent sheets of Examples 1 to 11 and Comparative Examples 1 to 10 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)).

[0051] (Production of Absorbent Articles) Using the absorbent sheet obtained above as an absorber, an air-through nonwoven fabric (basis weight 25 g / m 2 ) was used as a liquid-permeable top sheet, an air-through nonwoven fabric (basis weight 30 g / m 2 ) was used as a second sheet, 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 as a three-dimensional gather, and a breathable polyethylene sheet (basis weight 32 g / m 2 ) was used as a liquid-impermeable back sheet. When integrating the top sheet, the back sheet, and the absorber, a hot melt adhesive was used to bond the top sheet and the upper surface of the absorber, and absorbent articles of Examples 1 to 11 and Comparative Examples 1 to 10 were produced. The dimensions of the absorbent article were 230 mm in the longitudinal direction and 90 mm in the width.

[0052] [Evaluation] The absorbent articles of Examples 1 to 11 and Comparative Examples 1 to 10 obtained above were subjected to the following evaluations. The evaluation results are shown in Tables 2 and 3.

[0053] (Thickness of Absorbent Article) The thickness of the central part of the absorbent article was measured using an ABS digital height gauge HDS-HC (Mitutoyo Corporation). (Absorption rate three - time method) A hole with an inner diameter of 19 mm was opened in the center of a cylinder with a bottom area of 16.8 cm 2 A measuring jig with a weight of 755.6 g was placed on the central part of the absorbent article in the longitudinal and width directions. 20 ml of physiological saline was dropped from the upper hole respectively. 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 (the first time). Then, after 3 minutes, the same time was measured (the 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. If there was no leakage from the lower side of the absorbent article, it was judged as "○", and if leakage occurred, it was judged as "×".

[0054]

Table 1

[0055]

Table 2

[0056]

Table 3

[0057] 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 less likely to leak. On the other hand, the absorbent articles of Comparative Examples 1 to 10 in Table 3 had a 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

[0058] 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 Hydrophilic 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 between them, 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 an X shape in plan view on the skin-side surface of the absorbent sheet, with the intersection of the X shape located in the first 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, 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 angle of the angle formed by the X shape facing the edge in the width direction of the absorbent sheet is 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 from the wearer's skin side between the second superabsorbent polymer layer and the pulp sheet, The embossing groove reaches the skin-side surface of the pulp sheet by denting 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 from the skin-side surface of the absorbent sheet to the non-skin side. The absorbent article according to claim 1.

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.

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.

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.

6. The absorbent article according to any one of claims 1 to 5, wherein the pulp sheet is crepe paper containing a wet-strength agent.

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