WO2022044594A1 - Absorbent article - Google Patents

Abstract

A surface sheet (3) is divided into: an uneven region (32) that is located in a central part in the transverse direction (Y) of an absorbent article (1), and has, on a skin facing surface, an uneven shape including a plurality of protrusions (30) protruding toward the skin of a wearer; and even regions (33) that are located on both sides of the uneven region (32) in the transverse direction (Y), and do not have the uneven shape on the skin facing surface. An absorbent body (5) comprises a sheet-like absorbent (50) having a water-absorbing polymer (P) disposed between two base material sheets (51, 51) disposed to face each other in the thickness direction. In the sheet-like absorbent body (50), the basis weight of the water-absorbing polymer (P) in a portion (52) that overlaps the uneven region (32) in a plan view is a greater than that in portions (53) that overlap the even regions (33) in the plan view.

Description

Absorbent article

The present invention relates to an absorbent article that can be used to absorb and retain excrement such as urine.

Absorbent articles such as disposable diapers and menstrual napkins generally include a front sheet that is placed relatively close to the wearer's skin and a back sheet that is placed relatively far from the wearer's skin. , A liquid-retaining absorber disposed between the two sheets. Conventionally, there has been known a technique of imparting an uneven shape to a surface of a surface sheet that can come into contact with the wearer's skin (skin facing surface) to reduce the contact area with the wearer's skin and reduce stickiness and stuffiness. (See Patent Documents 1 to 4).

Further, as the absorber, conventionally, a fiber material such as wood pulp or a fiber material in which a particulate water-absorbing polymer is supported on the fiber material (hereinafter, these are collectively referred to as "fiber-type absorber"). Also called.) Is widely used. However, since the laminated fiber type absorber is relatively bulky and thick, it is excellent in cushioning property, but on the other hand, it is bulky, so that the appearance of the absorbent article is not refreshed and the appearance is deteriorated. Therefore, in recent years, as an absorber thinner than the fiber-stacked absorber, a absorbent polymer layer mainly composed of a water-absorbent polymer and not containing a fiber material (hereinafter, also referred to as "sheet-type absorber"). ) Has been proposed. As a sheet-type absorber, one in which a particulate water-absorbing polymer is arranged between two sheets arranged so as to face each other in the thickness direction is known. In Patent Documents 5 and 6, in an absorbent article provided with an absorber having a two-layer structure, the upper layer of the absorber, which is relatively close to the wearer's skin, is composed of a fiber-type absorber, and the relative in the absorber. The lower layer far from the wearer's skin is described as having a sheet-type absorber.

Japanese Unexamined Patent Publication No. 2004-49918 Japanese Unexamined Patent Publication No. 2009-173 EP2656826A1 Japanese Unexamined Patent Publication No. 2014-110890 US2008 / 312621A1 US2020 / 179187A1

The present invention has an absorber that has a vertical direction corresponding to the front-back direction of the wearer and a horizontal direction orthogonal to the vertical direction, and absorbs and holds body fluid, and a surface arranged on the skin facing surface side of the absorber. An absorbent article comprising a sheet.
In one embodiment of the absorber of the present invention, the surface sheet has a concavo-convex shape that is located at the laterally central portion of the absorbent article and includes a plurality of convex portions that protrude toward the wearer's skin side. It is divided into an uneven region having an uneven surface facing the skin and a non-concavo-convex region located on both sides of the uneven region in the lateral direction and having no uneven shape on the surface facing the skin.
In one embodiment of the absorber of the present invention, the absorber includes a sheet-type absorber in which a water-absorbent polymer is arranged between two base sheets arranged so as to face each other in the thickness direction.
In one embodiment of the absorber of the present invention, the portion of the sheet-type absorber that overlaps the uneven region in a plan view is more water-absorbing than the portion of the sheet-type absorber that overlaps the non-concave region in a plan view. The basis weight of the sex polymer is large.
Other features, effects and embodiments of the invention are described below.

FIG. 1 is a developed plan view schematically showing a skin-facing surface side (surface sheet side) in an unfolded and stretched state of a deployable disposable diaper according to an embodiment of the absorbent article of the present invention. FIG. 2 is a cross-sectional view schematically showing an I-I line cross section (cross section along the thickness direction of the inseam) of FIG. 1. FIG. 3 is an enlarged cross-sectional view showing the absorbent body of FIG. 2. FIG. 4 is a schematic cross-sectional view of the laminated structure of the absorber when the diaper of FIG. 1 is worn. FIG. 5 is a view corresponding to FIG. 3 of the absorbent body in another embodiment of the absorbent article of the present invention (a schematic cross-sectional view along the thickness direction of the crotch portion of the absorbent body). FIG. 6 is a view corresponding to FIG. 3 of the absorbent body in still another embodiment of the absorbent article of the present invention (a schematic cross-sectional view along the thickness direction of the inseam of the absorbent body). FIG. 7 is a view corresponding to FIG. 3 of the absorbent body in another embodiment of the absorbent article of the present invention (a schematic cross-sectional view along the thickness direction of the crotch portion of the absorbent body).

Detailed description of the invention

The absorbent article provided with the sheet-type absorber may give the wearer a grainy, jerky and unpleasant feel due to the particulate water-absorbent polymer filled in the absorber at a relatively high density. There were problems such as deterioration of texture and occurrence of discomfort when worn.

Therefore, the present invention relates to an absorbent article having excellent liquid absorption performance and wearing feeling.

Hereinafter, the present invention will be described based on the preferred embodiment thereof with reference to the drawings. In the description of the drawings below, the same or similar parts are designated by the same or similar reference numerals. The drawings are basically schematic, and the ratio of each dimension may differ from the actual one.

1 and 2 show a disposable diaper 1 which is an embodiment of the absorbent article of the present invention. The diaper 1 has a vertical direction X corresponding to the front-back direction of the wearer, that is, a direction extending from the ventral side to the dorsal side through the crotch portion, and a horizontal direction Y orthogonal to the vertical direction X. Further, the diaper 1 is arranged in the crotch portion of the wearer, and includes the inseam B including the excretion portion facing portion (not shown) facing the excretion portion such as the penis, and the wearer's ventral side (not shown). It is divided into three parts: a ventral part A arranged on the front side) and a dorsal part C arranged on the back side (rear side) of the wearer from the inseam B.

The ventral portion A and the dorsal portion C each typically include a waist circumference portion that is arranged around the wearer's waist circumference when the diaper 1 is worn. The ventral part A is a part of the front body of the diaper 1, and the dorsal part C is a part of the back body of the diaper 1. The inseam B typically includes at least a portion of the central portion of the diaper 1 in the longitudinal direction X and extends from the front to the back of the diaper 1.
In the present invention, the ventral portion A, the inseam B, and the dorsal portion C can be each region when the unfolded and extended diaper 1 is divided into three equal parts in the vertical direction X. The "expanded and stretched state" as used herein means that the diaper is in the unfolded state as shown in FIG. It means the state of being expanded until it becomes the same as the dimensions when it is expanded in a plane.

The diaper 1 includes an absorber 5 that absorbs and holds body fluid such as urine, and a surface sheet 3 arranged on the skin-facing surface side of the absorber 5.
In the present embodiment, the diaper 1 includes an absorbent main body 2, and the absorbent main body 2 includes a front surface sheet 3 and an absorbent body 5, and further includes a back surface sheet 4 arranged on the non-skin facing surface side of the absorbent body 5. do. The absorbent body 2 extends in the vertical direction X from the ventral side A to the dorsal side C, and its longitudinal direction coincides with the vertical direction X. The front surface sheet 3 forms a skin-facing surface (inner surface) of the diaper 1 together with the leak-proof cuff forming sheet 13, which will be described later, and the back surface sheet 4 forms a non-skin-facing surface (outer surface) of the diaper 1. The constituent members of the absorbent main body 2 are joined to each other by a known joining means such as an adhesive. As the constituent members of the absorbent main body 2, those normally used in this type of absorbent article are particularly limited on the premise that the explanation can be applied to the member if the explanation is given later. Can be used without. As the surface sheet 3, various sheets having liquid permeability can be used, and examples thereof include non-woven fabrics, woven fabrics, and papers. The back surface sheet 4 is a leak-proof sheet, specifically, a liquid impermeable (property that does not allow liquid to pass through) or a liquid impervious property (property that is not liquid impermeable but difficult to pass through). ) Can be used, and examples thereof include a moisture-permeable resin film and a laminate of the resin film and a non-woven fabric.

In the present specification, the "skin facing surface" is a surface of the absorbent article or a component thereof (for example, an absorbent body) that is directed toward the wearer's skin side when the absorbent article is worn, that is, the wearer's skin relatively. The "non-skin facing surface" is the surface of the absorbent article or its constituents that faces the opposite side of the skin when the absorbent article is worn, that is, relatively far from the wearer's skin. On the side. The term "when worn" as used herein means a state in which the normal proper wearing position, that is, the correct wearing position of the absorbent article is maintained.

The diaper 1 includes a flap portion 11 extending outward from the peripheral edge of the absorbent body 2, that is, the peripheral edge of the absorbent body 5. The flap portion 11 is composed of a member extending outward from the peripheral edge of the absorbent main body 2. In the present embodiment, as shown in FIG. 2, the front surface sheet 3 covers the entire area of the skin-facing surface of the absorber 5, and the back surface sheet 4 covers the entire non-skin-facing surface of the absorber 5, both sheets. Further, 3 and 4 extend outward in the lateral direction Y from both side edges along the vertical direction X of the absorber 5, and together with the leakage-proof cuff forming sheet 13 described later, form a side flap portion which is a part of the flap portion 11. Is forming. The side flap portion is a portion of the flap portion 11 located on both side edges of the absorber 5 (absorbent body 2) along the vertical direction X and outward in the lateral direction Y from the virtual extension lines of the both side edges. .. A plurality of members constituting the flap portion 11 are joined to each other by known joining means such as an adhesive, a heat seal, and an ultrasonic seal.

As shown in FIGS. 1 and 2, a pair of leakage- proof cuffs 12 and 12 standing up toward the wearer's skin side when worn are arranged along both sides of the absorbent body 2 along the vertical direction X. There is. Each leak-proof cuff 12 includes a liquid-resistant or water-repellent and breathable leak-proof cuff forming sheet 13, wherein one end side in the lateral direction Y is another member (surface sheet 3 in the illustrated form). And the fixed end portion 13a fixed to the back surface sheet 4), and the other end side in the lateral direction Y is a free end portion 13b which is not fixed to other members. An elastic member 14 for forming a leak-proof cuff is fixed to the free end portion 13b of the sheet 13 in an extended state in the vertical direction X so as to be expandable and contractible in the same direction. When wearing the diaper 1, due to the contraction force of the elastic member 14, at least in the crotch portion B, the free end portion 13b side of the sheet 13 stands up on the wearer side with the fixed end portion 13a with other members as the standing base end. This causes the pair of leak- proof cuffs 12, 12 to stand up, thereby preventing the outflow of excrement such as urine to the outside in the lateral direction Y.

A plurality of waist gather forming elastic members 15 are arranged so as to be expandable and contractible in the lateral direction Y at the flap portion 11 at the end portion (waist end portion) of each of the ventral side portion A and the dorsal side portion C in the vertical direction X. The plurality of elastic members 15 are intermittently arranged at predetermined intervals in the vertical direction X. As described above, since the elastic member 15 is arranged in a state in which its elasticity is exhibited, the waist end portions of the ventral side portion A and the dorsal side portion C, which are the arrangement portions thereof, are substantially covered over the entire circumference thereof. A continuous annular waist gather is formed.
Further, in the flap portion 11, the leg portion arranged around the wearer's leg when the diaper 1 is worn has an elastic member 16 for forming leg gathers that can be extended in the vertical direction X at least in the vertical direction X of the inseam B. It extends in the vertical direction X over the entire length of the diaper, whereby when the diaper 1 is worn, leg gathers are formed on the leg portion due to the contraction of the elastic member 16.
These gather-forming elastic members 15 and 16 are all of a plurality of sheets constituting the flap portion 11 (in this embodiment, two of the front surface sheet 3, the back surface sheet 4 and the leakage-proof cuff forming sheet 13). It is sandwiched and fixed in an extended state by a joining means such as an adhesive.
The form of each of the elastic members 14, 15 and 16 described above is not particularly limited, and for example, a thread-like or string-like (flat rubber or the like) having a rectangular, square, circular or polygonal cross section, or a multifilament type thread-like Etc. can be used.

The diaper 1 is a so-called deployable disposable diaper, and as shown in FIG. 1, the diaper 1 is provided with a fastening member 18 having a fastening portion 17 on both side edges of the dorsal portion C of the diaper 1 along the vertical direction X. The non-skin facing surface of the back surface sheet 4 forming the non-skin facing surface of the ventral side A is provided with a fastening region 19 to which the fastening portion 17 can be fastened.

FIG. 3 shows the surface sheet enlarged together with the absorber 5. The surface sheet 3 is located in the central portion of the diaper 1 in the lateral direction Y, and has a concave-convex shape including a plurality of convex portions 30 protruding toward the skin side of the wearer and concave portions 31 located around the convex portions 30. Is divided into a concavo-convex region 32 having an uneven surface facing the skin and a non-concavo-convex region 33 located on both sides of the concavo-convex region 32 in the lateral direction Y and having no concavo-convex shape on the skin facing surface.

As shown in FIGS. 1 to 3, in the portion of the surface sheet 3 that overlaps with the absorber 5 in a plan view, there are a concavo-convex region 32 and a pair of non-concavo- convex regions 33 and 33 located on both sides in the lateral direction Y thereof. do. The uneven region 32 is typically a region sandwiched between the free end portions 13b, 13b of the pair of leak-proof cuff forming sheets 13, 13 when the diaper 1 is expanded and extended as shown in FIG. Located in. Further, the uneven region 32 is typically formed symmetrically with respect to the vertical center line CLx that bisects the diaper 1 in the horizontal direction Y and virtually extends in the vertical direction X.

The uneven region 32 exists at least in the inseam B, and may also exist in the ventral side A and / or the dorsal side C. From the viewpoint of effectively utilizing the action effect of the uneven region 32 (the effect of improving cushioning property, the effect of reducing the contact area with the wearer's skin, etc.), the uneven region 32 comes into contact with the wearer's crotch (excretion part) and buttocks. It is preferable that they are arranged so as to obtain, and for that purpose, they are preferably arranged at least in the inseam B and the dorsal portion C (the portion of the dorsal portion C closer to the inseam B). In the diaper 1, as shown in FIG. 1, the uneven region 32 extends in the vertical direction X over the entire length of the diaper 1 in the vertical direction X.

The uneven pattern (shape and arrangement of the convex portion 30) of the uneven region 32 on the surface facing the skin of the surface sheet 3 is not particularly limited, and any one can be appropriately selected as long as it does not deviate from the gist of the present invention.
Examples of the plan view shape of the convex portion 30 include a circle, an ellipse, a triangle, and a polygon having a quadrangle or more. In the present embodiment, the plurality of convex portions 30 of the surface sheet 3 have the same shape and the same dimensions, but as in the embodiment described later, a plurality of types of convex portions having different shapes or dimensions may be mixed. The convex portion 30 may have a solid structure in which the constituent fibers of the surface sheet 3 are filled therein, or may be a hollow structure in which the constituent fibers are not filled.
As an example of the concavo-convex pattern of the concavo-convex region 32, there is a form in which a plurality of convex portions are arranged in a scattered pattern (for example, staggered) and the periphery of each convex portion is a concave portion.
As another example of the concavo-convex pattern of the concavo-convex region 32, a first concave portion having a plane line of sight extending in the first direction intersecting both the vertical direction and the horizontal direction and a plane extending in the second direction intersecting the first direction. A form in which the second concave portion having a line of sight is arranged in a grid pattern and a convex portion is present in each of a plurality of sections surrounded by both concave portions can be mentioned.
As yet another example of the uneven pattern of the uneven region 32, the convex portion as a ridge extending in the vertical direction or the horizontal direction and the concave portion as a groove extending in the same direction are orthogonal to the extending direction thereof. Examples thereof include forms in which they are arranged alternately in the direction in which they are used.

The method of forming the uneven region 32 is not particularly limited. The uneven region 32 is typically formed by partially squeezing the raw material, which is the raw material of the surface sheet 3, in which case the squeezed portion is the raw material. The sheet forming material is compacted to form a concave portion 31, and the portion not subjected to the pressing process protrudes to one side in the thickness direction, specifically to the skin facing surface side, and becomes a convex portion 30. Further, in this case, the convex portion 30 that has not been pressed is a low-density portion having a relatively low density, and the concave portion 31 that has been pressed is a high-density portion having a relatively high density. As the squeezing process, a known method can be used without particular limitation, and examples thereof include embossing process with or without heat, and ultrasonic embossing process.

The non-concavo-convex region 33 does not have an uneven shape on the surface facing the skin. That is, the skin-facing surface of the non-concavo-convex region 33 is a flat surface. The "concavo-convex shape" of "having no concavo-convex shape" here refers to a microscopic concavo-convex shape caused by the entanglement of the constituent fibers of the surface sheet, specifically, for example, a microscope for the surface of a normal flat surface sheet. It does not include the minute uneven shape that is seen when microscopically observed.
The non-skin facing surface (facing surface with the absorber 5) of the surface sheet 3 is typically a flat surface having no uneven shape in either the uneven region 32 or the non-concavo-convex region 33. ..

The absorber 5 includes a sheet-type absorber 50 in which the water-absorbent polymer P is arranged between the two substrate sheets 51, 51 which are arranged so as to face each other in the thickness direction (vertical direction of FIGS. 2 and 3). In the diaper 1 of the present embodiment, the absorber 5 is composed of a sheet-type absorber 50.
The arrangement layer of the water-absorbent polymer (layer sandwiched between the two base sheets 51, 51) in the sheet-type absorber 50 typically contains only the water-absorbent polymer as the water-absorbent material, and is a cellulosic fiber. Does not contain a water-absorbent fiber material such as, or even if it contains a water-absorbent fiber material, in a small amount (for example, 10% by mass or less, preferably 3% by mass or less with respect to the total mass of the arrangement layer of the water-absorbent polymer). be.
In the sheet-type absorber 50, for the purpose of bonding the two base sheets 51, 51 to each other or the base sheets 51 and the water-absorbent polymer, a layer for arranging the water-absorbent polymer on at least one of both sheets 51, 51. An adhesive such as a hot melt adhesive may be applied to the facing surface (inner surface) of the above.

As the base material sheet 51 constituting the sheet-type absorber 50, a sheet having liquid permeability or liquid absorption can be used. The base material sheet 51 is typically a fiber sheet mainly composed of fibers, that is, a fiber sheet having a fiber content of more than 50% by mass.
The constituent fibers of the base sheet 51 include, for example, wood pulp such as coniferous tree pulp and broadleaf tree pulp, natural fibers such as non-wood pulp such as cotton pulp and hemp pulp; and modified pulp such as cationized pulp and marcelified pulp (above). , Cellulous fiber); Synthetic fibers composed of resins such as polyethylene and polypropylene can be mentioned, and one of these can be used alone or in combination of two or more.
Examples of the form of the base material sheet 51 include paper, woven fabric, and non-woven fabric. Examples of the non-woven fabric include air-through non-woven fabric, heat roll non-woven fabric, spunlace non-woven fabric, spunbond non-woven fabric, meltblown non-woven fabric, and spunbond-meltblown-. Spunbond (SMS) non-woven fabric can be mentioned. The base sheet 51 is typically a single-layer structure composed of one of these types, but may be a laminated structure in which two or more types are laminated and integrated.
The basis weight of the base sheet 51 is not particularly limited, but is preferably 5 g / m ² or more, more preferably 8 g / m ² or more, from the viewpoint of ensuring that the sheet-type absorber 50 exerts a predetermined effect. And it is preferably 50 g / m ² or less, and more preferably 30 g / m ² or less.
The two base material sheets 51, 51 constituting the sheet type absorber 50 may be the same as each other, or may differ in one or more characteristics such as composition, material, and physical properties.

As the water-absorbent polymer constituting the sheet-type absorber 50, those that can be used for this type of absorber can be used without particular limitation, and typically, a hydrogel material capable of absorbing and retaining water is used. For example, a polymer or copolymer of acrylic acid or an alkali metal salt of acrylic acid can be used. Examples thereof include polyacrylic acid and salts thereof, and polymethacrylic acid and salts thereof, and specific examples thereof include partial sodium salts of acrylic acid polymers. The shape of the water-absorbent polymer is not particularly limited, and may be, for example, spherical, tufted, lumpy, bale-shaped, fibrous, amorphous, or a combination of these particles.

With reference to FIGS. 3 and 4, in the diaper 1, a portion (hereinafter, also referred to as a “concavo-convex region corresponding portion”) 52 that overlaps the uneven region 32 in the sheet type absorber 50 in a plan view is formed in the absorber 50. It is characterized in that the basis weight of the water-absorbent polymer is larger than that of the portion (hereinafter, also referred to as “non-concavo-convex region corresponding portion”) 53 that overlaps the non-concavo-convex region 33 in a plan view.

As shown in FIG. 4, the central portion of the diaper 1 in which the uneven region 32 of the surface sheet 3 is arranged in the lateral direction Y is the excretion portion (not shown) and the buttocks 90 of the wearer who excretes excrement such as urine. Since it is a part that can come into contact with the body, liquid absorption performance and wearing feeling are particularly important. Therefore, in the present invention, the uneven region 32 having excellent cushioning property and surface dry feeling is arranged on the skin-facing surface of the portion of the surface sheet 3 located in the central portion of the diaper 1 in the lateral direction to improve the wearing feeling. ing. In addition, in the present invention, when the water-absorbent polymer is arranged at a high basis weight, the sheet-type absorber 50 pays attention to the fact that the high basis weight arrangement portion of the water-absorbent polymer improves not only the liquid absorption performance but also the cushioning property. As described above, regarding the basis weight of the water-absorbent polymer of the absorber 50, in order to unevenly distribute the water-absorbent polymer of The size relationship of "area corresponding unit 53" is established. With the establishment of such a magnitude relationship, the absorption capacity of the uneven region corresponding portion 52 located at the center of the lateral direction Y of the diaper 1 is sufficient to impart practically sufficient liquid absorption performance to the diaper 1. The cushioning property of the central portion is enhanced by the effect of improving the cushioning property by both the uneven area 32 and the uneven area corresponding portion 52. Since the particulate water-absorbing polymer is arranged at a relatively high density in the uneven region corresponding portion 52, there is a concern that the wearer may be given a grainy feeling or a jerky and unpleasant tactile sensation. Since the uneven region 32 having excellent cushioning property is interposed between the 52 and the wearer's skin, such a concern is dispelled. Further, due to the establishment of such a magnitude relationship, the portion (side portion) of the surface sheet 3 in which the non-concave-convex region 33 is arranged in the diaper 1 has a cushioning property due to the action of the non-concave-convex region-corresponding portion 53. Due to the relatively small basis weight of the water-absorbent polymer of the non-concavo-convex region corresponding portion 53, the thickness is thin, the rigidity is low, and the diaper is easily deformed. It is possible to follow the curved shape of the wearer's buttocks 90, which can improve the fit of the diaper 1 as a whole to the buttocks 90. Therefore, the diaper 1 is excellent in liquid absorption performance and wearing feeling.

The surface sheet 3 may have a single-layer structure or a laminated structure in which a plurality of layers are laminated in the thickness direction. A laminated structure is preferable from the viewpoint of reducing the number of diapers and further improving the wearing feeling of the diaper 1. As an example of the surface sheet 3 having a laminated structure, two sheets are partially joined in a laminated state, and one of the two sheets (skin side sheet) relatively close to the wearer's skin is used. , A two-layer structure surface sheet in which a convex portion 30 is formed by protruding in a direction away from the other sheet (non-skin side sheet) at a portion other than the joint portion. A non-woven fabric is preferably used as the sheet constituting the surface sheet 3. Examples of the non-woven fabric include air-through non-woven fabric, heat roll non-woven fabric, spunlace non-woven fabric, spunbond non-woven fabric, meltblown non-woven fabric, and spunbond-meltblown-spunbond (SMS) non-woven fabric.

From the viewpoint of ensuring that the action and effect of the combination of the surface sheet 3 and the sheet type absorber 50 are more reliably exerted, the length (width) of the uneven region 32 of the surface sheet 3 in the lateral direction Y and the sheet type absorption The length (width) of the lateral Y of the concave-convex region corresponding portion 52 of the body 50 is preferably 30% or more, more preferably 35% or more, respectively, with respect to the length (width) of the lateral Y of the diaper 1. , And preferably 70% or less, more preferably 65% or less.
From the same viewpoint, the length (width) of the non-concavo-convex region 33 of the surface sheet 3 in the lateral direction Y and the length (width) of the non-concavo-convex region corresponding portion 53 of the sheet type absorber 50 in the lateral direction are respectively. The width of the diaper 1 is preferably 8% or more, more preferably 10% or more, and preferably 35% or less, more preferably 30% or less.
The above-mentioned "width of diaper 1 (absorbent article)" refers to the length or width of the diaper 1 (absorbent article) in the unfolded and extended state as shown in FIG. 1, and refers to the length, that is, the width of the diaper of the present embodiment. When this width is not constant in the vertical direction X as in 1, it means the minimum width (the minimum value of the length in the horizontal direction Y). In this embodiment, the diaper 1 has a minimum width in the inseam B.

From the viewpoint of ensuring that the action and effect of the combination of the surface sheet 3 and the sheet-type absorber 50 are more reliably exerted, the basis weight of the water-absorbent polymer of each part of the sheet-type absorber 50 is set as follows. Is preferable.
The ratio of the basis weight of the water-absorbent polymer of the uneven region corresponding portion 52 to the basis weight of the water-absorbent polymer of the non-uneven region corresponding portion 53 is preferably 2 or more, more preferably 2 or more, assuming the former> the latter. Is 5 or more, preferably 30 or less, and more preferably 25 or less.
The basis weight of the water-absorbent polymer of the uneven region corresponding portion 52 is preferably 50 g / m ² or more, more preferably 60 g / m, on the premise that the basis weight of the water-absorbent polymer of the uneven region corresponding portion 53 is larger than the basis weight of the water-absorbent polymer of the non-uneven region corresponding portion 53. ² or more, preferably 150 g / m ² or less, more preferably 120 g / m ² or less.
The basis weight of the water-absorbent polymer of the non-concavo-convex region corresponding portion 53 is preferably 1 g / m ² or more, more preferably 5 g / m, assuming that the basis weight of the water-absorbent polymer of the uneven region corresponding portion 52 is smaller than the basis weight of the water-absorbent polymer of the uneven region corresponding portion 52. ² or more, preferably 50 g / m ² or less, more preferably 30 g / m ² or less.

From the viewpoint of ensuring that the action and effect of the combination of the surface sheet 3 and the sheet type absorber 50 are more reliably exerted, the dimensions and the like of the convex portion 30 of the uneven region 32 of the surface sheet 3 are set as follows. Is preferable.
The protruding height of the convex portion 30 is preferably 0.3 mm or more, more preferably 0.6 mm or more, and preferably 5.0 mm or less, more preferably 4.0 mm or less.
The area of the convex portion 30 is preferably 0.2 mm ² or more, more preferably 0.5 mm ² or more, and preferably 100 mm ² or less, more preferably 80 mm ² or less.
The number of convex portions 30 per unit area (1000 mm ² ) in the uneven region 32 is preferably 50 pieces / 1000 mm ² or more, more preferably 100 pieces / 1000 mm ² or more, and preferably 2000 pieces / 1000 mm ² or less. It is preferably 1000 pieces / 1000 mm ² or less.
The above-mentioned "protruding height of the convex portion 30 of the uneven region 32" refers to an average value of the protruding heights of the plurality of convex portions 30 existing in the uneven region 32, and refers to the above-mentioned "area of the convex portion 30 of the uneven region 32". Refers to the average value of the areas of the plurality of convex portions 30 existing in the uneven region 32.
The protruding height, area, and number of protrusions per unit area of the surface sheet are measured by the following methods, respectively.

<Measuring method of protruding height of convex part of surface sheet>
The uneven region of the surface sheet to be measured is cut in the thickness direction using a cutting tool such as a sharp razor, and the cut surface is observed. ) And the top of the convex, that is, the shortest distance between the virtual straight line extending horizontally through the bottom of the recess and the virtual straight line extending horizontally through the top of the convex (both). The length of the vertical line orthogonal to the virtual straight line (the length between the two virtual straight lines) is measured under no load and is taken as the protruding height of the convex portion. The protruding height of the convex portion corresponds to the apparent thickness of the surface sheet. When observing the cut surface with the naked eye, for example, the cut surface is observed and measured at a magnification of 20 to 100 times using a microscope (VHX-1000 manufactured by KEYENCE). You may.
For each of the five regions arbitrarily selected from one target region (for example, the uneven region 32), the protrusion height of the convex portion is measured by the above procedure, and the average value of the measured values of the five regions is used as the target region. The protruding height of the convex part of.

<Measuring method of the area of the convex part of the surface sheet>
A quadrangular shape in a plan view having a length of 50 mm in the vertical direction and 20 mm in the horizontal direction is cut out from the surface sheet to be measured and used as a test piece. The skin contact surface side of the measurement piece is observed under no load using a microscope (for example, a microscope manufactured by KEYENCE, VHX-1000) at an observation magnification of 10 to 100 times. Next, the center of gravity of each of the plurality of concave portions formed so as to surround one convex portion is connected by a straight line, and the area of the polygonal shape in a plan view surrounded by the straight line is defined as the area of the convex portion, and the image analysis software is used. It is used to measure the area of the convex portion. If the surface sheet has a plurality of types of convex portions having different protrusion heights or areas, each convex portion (for example, in the case of the surface sheet 3 of the diaper 1A described later, the first convex portion 30A and the second convex portion 30B). The area is measured by the same procedure as described above. For each of the three regions arbitrarily selected from one target region (for example, the first concave-convex region 320 or the second concave-convex region 321 in the diaper 1A described later), the area of the convex portion is measured by the above procedure, and the three regions are measured. The average value of the measured values of is taken as the area of the convex portion of the target area.

<Measuring method of the number of convex parts of the surface sheet per unit area>
A quadrangular shape in a plan view having a length of 50 mm in the vertical direction and 20 mm in the horizontal direction is cut out from the surface sheet to be measured and used as a test piece. The test piece is observed with a microscope (for example, a microscope manufactured by KEYENCE, VHX-1000) at an observation magnification of 20 to 100 times, and the number of convex portions of the test piece is measured. The measured value divided by the area of the test piece (1000 mm ² ) is taken as the number per unit area of the convex portion of the surface sheet to be measured.

5 to 7 show other embodiments of the absorbent article of the present invention. Regarding other embodiments described later, components different from the above-mentioned diaper 1 will be mainly described, and similar components will be designated by the same reference numerals and description thereof will be omitted. The above-mentioned description of the diaper 1 is appropriately applied to the configurations not particularly described in the other embodiments described later.

In the diaper 1A shown in FIG. 5, the uneven region 32 of the surface sheet 3 protrudes from the first convex portion 30A (large convex portion) and the first convex portion 30A as convex portions constituting the uneven region 32. Includes a second convex portion 30B (small convex portion) having a low height or a small area. More specifically, the uneven region 32 of the surface sheet 3 includes a plurality of convex portions 30A and 30B protruding toward the wearer's skin side and concave portions 31A and 31B located around the convex portions 30A and 30B. include. Further, the surface sheet 3 uneven region 32 is located at the center of the uneven region 32 in the lateral direction Y, and has a first uneven region 320 in which the first convex portion 30A and the first concave portion 31A are arranged, and the first uneven region. It is located on both sides of the region 320 in the lateral direction Y, and is divided into a second uneven region 321 in which the second convex portion 30B and the second concave portion 31B are arranged. In the diaper 1A, the portion 54 that overlaps with the first uneven region 320 in the sheet type absorber 50 in a plan view (hereinafter, also referred to as “first uneven region corresponding portion”) 54 is the second uneven region 321 in the absorber 50. The water-absorbent polymer has a larger basis weight than the portion (hereinafter, also referred to as “second uneven region corresponding portion”) 55 that overlaps with the water-absorbing polymer in a plan view, and the second uneven region corresponding portion 55 is the absorber 50. The basis weight of the water-absorbent polymer is larger than that of the portion overlapping the non-concave-convex region 33 in a plan view (non-concave-convex region corresponding portion 53). That is, in the diaper 1A, the magnitude relationship of "first uneven region corresponding portion 54> second uneven region corresponding portion> non-concavo-convex region corresponding portion 53" is established with respect to the basis weight of the water-absorbent polymer in the sheet type absorber 50. ..

Only one of the protrusion height and the area is different between the convex portion 30A (large convex portion) of the first uneven region corresponding portion 54 and the convex portion 30B (small convex portion) of the second uneven region corresponding portion 55. Well, both may be different.
The above-mentioned "protruding height of the convex portion 30A of the first uneven region corresponding portion 54" refers to the average value of the protruding heights of the plurality of convex portions 30A existing in the first uneven region corresponding portion 54, and refers to the above-mentioned "first uneven region corresponding portion 54". "Area of the convex portion 30A of the one uneven region corresponding portion 54" refers to the average value of the areas of the plurality of convex portions 30A existing in the first uneven region corresponding portion 54. The same applies to the protruding height and area of the convex portion 30B of the second uneven region corresponding portion 55.

In the diaper 1A, among the central portions of the lateral Y of the diaper 1A in which a relatively large amount of excrement is excreted, the water-absorbent polymer is most placed in the central portion of the lateral Y in the central portion where the excrement tends to concentrate. By arranging it with a high basis weight, the liquid absorption performance is improved. On the other hand, the portion facing the excretion portion or the portion at the same position in the vertical direction X is a portion that is often touched by the user, for example, to confirm the softness of the diaper 1A, not only when the diaper 1A is worn but also when the diaper 1A is not worn. This is a part that greatly affects the evaluation of the wearing feeling of the diaper 1A. If the first uneven region corresponding portion 54 in which the water-absorbent polymer is arranged at the highest basis weight in the sheet type absorber 50 is arranged in such a portion, it is advantageous in terms of improving the liquid absorption performance, but the wearer. There is a concern that the water-absorbent polymer may give a grainy feeling or a jerky and unpleasant touch. However, in the diaper 1A, the skin facing surface of the surface sheet 3 arranged on the skin facing surface side of the first uneven region corresponding portion 54 is provided with the first convex portion 30A (large convex portion) having a relatively large protruding height or area. By setting the first concavo-convex region 320 to include, such a concern is dispelled. Further, in the surface sheet 3, the second uneven region 321 including the second convex portion 30B having a relatively low height or a small area is arranged on both sides of the first uneven region 320 in the lateral direction Y, so that when worn. When a load is applied to the surface sheet 3 in the thickness direction, the second convex portion 30B resists the load together with the first convex portion 30A, so that the heights of the two convex portions 30A and 30B or It is possible to maintain the area, and further, the second uneven region 321 connected to the non-concavo-convex region 33 has a change in height or area, so that it is possible to suppress a feeling of discomfort in wearing.

From the viewpoint of ensuring that the action and effect of the combination of the surface sheet 3 and the sheet-type absorber 50 in the above-mentioned diaper 1A is more reliably exerted, the length (width) of the first uneven region 320 of the surface sheet 3 in the lateral direction Y. ), The length (width) of the first uneven region corresponding portion 54 of the sheet type absorber 50 in the lateral direction Y is preferably 15% or more, more preferably 20% or more, respectively, with respect to the width of the diaper 1. It is more preferably 25% or more, preferably 50% or less, and more preferably 40% or less.
From the same viewpoint, the length (width) of the second uneven region 321 of the surface sheet 3 in the lateral direction Y and the length (width) of the lateral Y of the second uneven region corresponding portion 55 of the sheet type absorber 50 are determined. Each is preferably 10% or more, more preferably 15% or more, and preferably 40% or less, more preferably 35% or less, with respect to the width of the diaper 1. The second concavo-convex region 321 is located on both sides of the first concavo-convex region 320 in the lateral direction Y. As described above, the ratio of the length (width) of the second uneven region 321 in the lateral direction Y to the width of the diaper 1 is the width of the diaper 1 and the length (width) of the horizontal Y of one second uneven region 321. Calculated by dividing by. Further, one second uneven region corresponding portion 55 is located on both sides of the first uneven region 320 in the lateral direction Y. The ratio of the length (width) of the second uneven region corresponding portion 55 to the width of the diaper 1 in the lateral direction Y is the width of the diaper 1 and the length (width) of the lateral Y of one second uneven region corresponding portion 55. ) To calculate.
The above-mentioned "width of diaper 1 (absorbent article)" is as described above.
The length of the first concavo-convex region 320 in the lateral direction Y is longer than the length of each of the pair of second concavo-convex regions 321 located on both sides of the first concavo-convex region 320 in the lateral direction Y. Moreover, it is preferable that the total length of each of the pair of second uneven regions 321 in the lateral direction is equal to or larger than the total length of each of the pair of second uneven regions 321 from the viewpoint of the balance between absorption performance and wearing feeling.

From the viewpoint of ensuring that the combination of the surface sheet 3 and the sheet-type absorber 50 in the above-mentioned diaper 1A exerts the action and effect more reliably, the basis weight of the water-absorbent polymer of each part of the sheet-type absorber 50 is as follows. It is preferable to set to.
The ratio of the basis weight of the water-absorbent polymer of the first uneven region corresponding portion 54 to the basis weight of the water-absorbent polymer of the second uneven region corresponding portion 55 is preferably 1. It is 5 or more, more preferably 1.7 or more, and preferably 3.5 or less, more preferably 3.0 or less.
The basis weight of the water-absorbent polymer of the first uneven region corresponding portion 54 is preferably 70 g / m ² or more, more preferably 70 g / m 2 or more, assuming that the basis weight of the water-absorbent polymer of the second uneven region corresponding portion 55 is larger than the basis weight of the water-absorbent polymer of the second uneven region corresponding portion 55. It is 80 g / m ² or more, preferably 150 g / m ² or less, and more preferably 120 g / m ² or less.
The basis weight of the water-absorbent polymer of the second uneven region corresponding portion 55 is preferably 20 g / m ² or more, more preferably 20 g / m 2 or more, assuming that the basis weight of the water-absorbent polymer of the first uneven region corresponding portion 54 is smaller than the basis weight of the water-absorbent polymer of the first uneven region corresponding portion 54. It is 30 g / m ² or more, preferably 100 g / m ² or less, and more preferably 90 g / m ² or less.

From the viewpoint of ensuring that the combination of the surface sheet 3 and the sheet-type absorber 50 in the above-mentioned diaper 1A exerts the action and effect more reliably, the dimensions and the like of the convex portions 30A and 30B of the uneven region 32 of the surface sheet 3 are as follows. It is preferable to set as follows.
The ratio of the protruding height of the convex portion 30A (large convex portion) to the protruding height of the convex portion 30B (small convex portion) is preferably 1.2 or more, more preferably 1.2 or more, assuming the former> the latter. It is 1.5 or more, preferably 10.0 or less, and more preferably 8.0 or less.
The protrusion height of the convex portion 30A (large convex portion) is preferably 0.5 mm or more, more preferably 1.0 mm or more, assuming that the protrusion height is higher than that of the convex portion 30B (small convex portion). The thickness is preferably 5.0 mm or less, more preferably 4.0 mm or less.
The protruding height of the convex portion 30B (small convex portion) is preferably 0.3 mm or more, more preferably 0.6 mm or more, on the premise that it is lower than the protruding height of the convex portion 30A (large convex portion). The thickness is preferably 3.0 mm or less, more preferably 2.5 mm or less.
The ratio of the area of the convex portion 30A (large convex portion) to the area of the convex portion 30B (small convex portion) is preferably 2.0 or more, more preferably 3. It is 0 or more, preferably 10.0 or less, and more preferably 8.0 or less.
Assuming that the area of the convex portion 30A (large convex portion) is larger than the area of the convex portion 30B (small convex portion), the area is preferably 0.8 mm ² or more, more preferably 3.0 mm ² or more, and It is preferably 100 mm ² or less, more preferably 80 mm ² or less.
Assuming that the area of the convex portion 30B (small convex portion) is smaller than the area of the convex portion 30A (large convex portion), the area is preferably 0.2 mm ² or more, more preferably 0.5 mm ² or more, and It is preferably 50.0 mm ² or less, and more preferably 20.0 mm ² or less.
The number of convex portions 30A (large convex portions) per unit area (1000 mm ² ) in the first uneven region corresponding portion 54 is preferably 50 pieces / 1000 mm ² or more, more preferably 100 pieces / 1000 mm ² or more, and preferably. Is 1000 pieces / 1000 mm ² or less, more preferably 500 pieces / 1000 mm ² or less.
The number of convex portions 30B (small convex portions) per unit area (1000 mm ² ) in the second uneven region corresponding portion 55 is preferably 65 pieces / 1000 mm ² or more, more preferably 200 pieces / 1000 mm ² or more, and preferably. Is 2000 pieces / 1000 mm ² or less, more preferably 1000 pieces / 1000 mm ² or less.

In the diaper 1B shown in FIG. 6, between the first uneven region 320 of the surface sheet 3 and the portion of the sheet type absorber 50 that overlaps the first uneven region 320 in a plan view (first uneven region corresponding portion 54). , The intermediate layer 10 is arranged. That is, in the diaper 1B, the intermediate layer 10 that can function as a cushion layer is arranged on the skin facing surface side of the first uneven region corresponding portion 54 having the maximum basis weight of the water-absorbent polymer in the sheet type absorber 50. Therefore, the diaper 1B is superior to the diaper 1A in which the intermediate layer 10 is not arranged, and is particularly excellent in the effect of reducing the grainy feeling and the jerky and unpleasant tactile sensation caused by the water-absorbent polymer, and is excellent in the wearing feeling.

The intermediate layer 10 may be located at least in the inseam B and may be located in the ventral side A and / or the dorsal side C. From the viewpoint of effectively utilizing the action effect (cushioning property improving effect) of the intermediate layer 10, the intermediate layer 10 is preferably arranged so as to be in contact with the wearer's crotch (excretion part) and buttocks. Is preferably arranged at least in the lower crotch B and the dorsal side C (the portion of the dorsal side C closer to the lower crotch B).
The intermediate layer 10 extends not only to a portion that overlaps with the first uneven region 320 (first uneven region corresponding portion 54) in a plan view, but also extends outward in the lateral direction Y from the portion, and the second uneven region 321 (first uneven region corresponding portion 54). 2 It may be arranged in a portion that overlaps with the concave-convex region corresponding portion 55) in a plan view.

As the intermediate layer 10, a liquid permeable layer can be used. As the intermediate layer 10, for example, a liquid-permeable sheet, which is also called a second sheet or a sub-layer sheet in the present technology, can be used, and examples of the sheet include paper, non-woven fabric, and woven fabric. Further, as the intermediate layer 10, a fiber aggregate thicker and bulkier than the sheet can be used, and the constituent fibers of the fiber aggregate can be used, for example, as the constituent fibers of the base sheet 51 described above. Things can be used.
The basis weight of the intermediate layer 10 is preferably 10 g / m ² or more, more preferably 15 g / m ² or more, and preferably 100 g / m ² or less, more preferably 80 g / m ² or less.

In the diaper 1C shown in FIG. 7, the absorber 5 is arranged on the skin-facing surface side of the sheet-type absorber 50, and the first layer 6 in which the water-absorbent polymer P is supported on the fiber stack of the fiber material, and the absorption thereof. It has a laminated structure (two-layer structure) 8 with a second layer 7 made of a body 50. Except for the above points, the diaper 1B shown in FIG. 6 is configured in the same manner as the diaper 1B. Body fluids such as urine excreted by the wearer of the diaper 1C permeate the laminated structure 8 in the order of the first layer 6 and the second layer 7 (sheet type absorber 50). The first layer 6 is arranged so as to overlap the first uneven region 320 in a plan view.

The first layer 6 is typically a mixed layer of a fiber material and a water-absorbent polymer, and is a so-called stacking fiber type absorber. As the water-absorbent polymer constituting the first layer 6, the same water-absorbent polymer as the water-absorbent polymer constituting the second layer 7 (sheet type absorber 50) can be used.
In the first layer 6, the water-absorbent polymer may be uniformly distributed or unevenly distributed throughout the first layer 6. Typically the former. As a specific example of the latter, a form in which the water-absorbent polymer is unevenly distributed on the skin-facing surface side or the non-skin facing surface side of the first layer 6, that is, either the skin facing surface side or the non-skin facing surface side is the other. It is possible to exemplify a form in which the content of the water-absorbent polymer is higher than that of the above. Here, the skin-facing surface side of the first layer 6 and the non-skin-facing surface side of the first layer 6 are separated by a virtual straight line (not shown) that bisects the first layer 6 in the thickness direction.
As the fiber material constituting the first layer 6, those that can be used for this kind of absorber can be used without particular limitation, and one kind can be used alone or two or more kinds can be used in combination. As the fiber material, a water-absorbent fiber material is preferable. Examples of the water-absorbent fiber material include wood pulp such as coniferous tree pulp and broadleaf tree pulp, natural fiber such as non-wood pulp such as cotton pulp and hemp pulp; and modified pulp such as cationized pulp and marcelled pulp (above, cellulose-based). Fiber); Examples include hydrophilic synthetic fiber.

The basis weight of the first layer 6 and the content of the forming material are not particularly limited, but it is preferable to set as follows from the viewpoint of ensuring that the predetermined effect of the first layer 6 is exhibited.
The basis weight of the first layer 6 is preferably 10 g / m ² or more, more preferably 50 g / m ² or more, and preferably 600 g / m ² or less, more preferably 500 g / m ² or less.
The content of the fiber material in the first layer 6 is preferably 5% by mass or more, more preferably 10% by mass or more, and preferably 70% by mass or less, more preferably 70% by mass or less, based on the total mass of the first layer 6. It is 65% by mass or less.
The content of the water-absorbent polymer in the first layer 6 is preferably 30% by mass or more, more preferably 35% by mass or more, and preferably 95% by mass or less, more preferably, based on the total mass of the first layer 6. Is 90% by mass or less.

The first layer 6 can be manufactured according to a conventional method using a known fiber stacking device equipped with a rotating drum. The fiber stacking device is typically a rotary drum having an accumulation recess formed on the outer peripheral surface, and a duct having a flow path inside the forming material (fiber material, water-absorbent polymer) in the accumulation recess. The forming material is carried on the air flow generated in the flow path by suction from the inside of the rotating drum while rotating the rotating drum around the rotation axis along the circumferential direction of the rotating drum. , The fiber is made to be stacked in the accumulation recess. The fiber stack formed in the accumulation recess by the fiber stacking step is the first layer 6.

In the form shown in FIG. 7, the absorber 5 includes a core wrap sheet 9 that covers the outer surface of the laminated structure 8, and the core wrap sheet 9 has one skin-facing surface and a non-skin-facing surface of the laminated structure 8. It is covered with. As the core wrap sheet 9, a sheet having liquid permeability can be used, and for example, paper, non-woven fabric, or woven fabric can be used. The absorber 5 may not be provided with the core wrap sheet 9, or may be provided with a plurality of core wrap sheets 9. In the latter case, for example, the absorber 5 includes one skin-side core wrap sheet that covers the skin-facing surface of the laminated structure 8 and one non-skin-side core wrap sheet that covers the non-skin-facing surface of the laminated structure 8. And may be provided.

According to diaper 1C, basically the same effect as diaper 1B is achieved. In particular, in the diaper 1C, the sheet type absorber 50 (second layer 7 of the absorber 5) can function as a cushion layer on the skin-facing surface side of the first uneven region corresponding portion 54 having the maximum basis weight of the water-absorbing polymer. In addition to the intermediate layer 10, the first layer 6 constituting the absorber 5 is further arranged together with the absorber 50, so that the water-absorbent polymer is particularly suitable as compared with the diaper 1B in which the first layer 6 is not arranged. It has an excellent effect of reducing the resulting grainy feeling and unpleasant tactile sensation, and is excellent in wearing feeling.

In the laminated structure 8, the first layer 6 absorbs more water than the second layer 7 (a portion overlapping the first layer 6 in the second layer 7 in a plan view. In the illustrated embodiment, the first uneven region corresponding portion 54). It is preferable that the basis weight of the polymer is large and the density of the water-absorbent polymer is lower than that of the second layer 7. That is, the magnitude relationship of "first layer 6> second layer 7" is established for the basis weight of the water-absorbent polymer, and the magnitude relationship of "first layer 6 <second layer 7" is established for the density of the water-absorbent polymer. Is preferable. In this way, the basis weight of the water-absorbent polymer of the first layer 6 located relatively close to the wearer's skin is larger than that of the second layer 7 located relatively far from the wearer's skin. By increasing the amount, the absorption capacity of the absorber 5 can be sufficiently secured and the liquid absorption performance can be improved. Further, by lowering the density of the water-absorbent polymer of the first layer 6 to be lower than that of the second layer 7, the flexibility of the first layer 6 is improved, and the second layer 7 (for example, the sheet type absorber 50 is the first. 1 The feeling of graininess and the unpleasant tactile sensation caused by the water-absorbent polymer of the uneven region corresponding portion 54) can be effectively reduced, and the wearing feeling can be improved.

In the laminated structure 8, the ratio of the basis weight of the water-absorbent polymer of the first layer 6 to the basis weight of the water-absorbent polymer of the second layer 7 is preferably 1.1 as the former / the latter, assuming the former> the latter. The above is more preferably 1.2 or more, preferably 3.0 or less, and more preferably 2.5 or less.
The basis weight of the water-absorbent polymer of the first layer 6 constituting the laminated structure 8 is preferably 55 g / m on the premise that it is larger than the basis weight of the water-absorbent polymer of the second layer 7 constituting the laminated structure 8. It is ² or more, more preferably 70 g / m ² or more, preferably 450 g / m ² or less, and more preferably 300 g / m ² or less.
The basis weight of the water-absorbent polymer of the second layer 7 constituting the laminated structure 8 is preferably 50 g / m on the assumption that it is smaller than the basis weight of the water-absorbent polymer of the first layer 6 constituting the laminated structure 8. It is ² or more, more preferably 60 g / m ² or more, preferably 150 g / m ² or less, and more preferably 120 g / m ² or less.
In the laminated structure 8, the ratio of the density of the water-absorbent polymer of the first layer 6 to the density of the water-absorbent polymer of the second layer 7 is preferably 0.05 or more as the former / the latter, assuming the former <the latter. It is more preferably 0.07 or more, preferably 0.5 or less, and more preferably 0.4 or less.
The density of the water-absorbent polymer of the first layer 6 constituting the laminated structure 8 is preferably 0.05 g / cm on the premise that the density of the water-absorbent polymer of the second layer 7 constituting the laminated structure 8 is lower. ³ or more, more preferably 0.07 g / cm ³ or more, and preferably 1.0 g / cm ³ or less, more preferably 0.8 g / cm ³ or less.
The density of the water-absorbent polymer of the second layer 7 constituting the laminated structure 8 is preferably 1.0 g / cm on the premise that the density of the water-absorbent polymer of the first layer 6 constituting the laminated structure 8 is higher. It is ³ or more, more preferably 1.2 g / cm ³ or more, and preferably 2.0 g / cm ³ or less, more preferably 1.8 g / cm ³ or less.
The density of the water-absorbent polymer of each layer (first layer 6, second layer 7) constituting the laminated structure 8 can be measured by the following method.

<Measuring method of density of water-absorbent polymer>
Taking the above-mentioned diaper 1C as an example, first, five absorbent main bodies 2 to be measured are prepared. Then, by removing members other than the absorber 5 such as the surface sheet 3 from each absorbent body 2, the absorber 5 (laminated structure 8) is taken out and placed in a horizontal place so as not to be wrinkled or bent. A square-shaped region of 70 mm in the vertical direction X and 70 mm in the horizontal direction Y is cut out from each of the layers (first layer 6, second layer 7) to be measured in each absorber 5 and used as a measurement target. .. The thickness of this object to be measured under a load of 0.6 g / cm ² is measured. The thickness of the object to be measured can be measured by using, for example, a laser displacement meter (LK-080) manufactured by KEYENCE CORPORATION. In the thickness measurement of the object to be measured, a square plate (50 x 50 mm, thickness of about 5 mm) whose size is adjusted so that the load is 0.6 g / cm ² is placed on the object to be measured. In the arranged state, the thickness of the object to be measured is measured using the laser displacement meter. The thickness of the object to be measured is measured at any five points in the plane direction by the above method, and the average value thereof is taken as the thickness of the object to be measured (first layer 6, second layer 7). Then, by dividing the basis weight of the water-absorbent polymer of each layer 6 and 7 by the thickness of each layer 6 and 7, the density of the target water-absorbent polymer of the first layer 6 and the second layer 7 is calculated.

Although the present invention has been described above based on the preferred embodiment thereof, the absorbent article of the present invention is not limited to the embodiment and can be appropriately modified. All the parts of only one embodiment described above can be mutually used as appropriate.
For example, the diaper 1C shown in FIG. 7 was provided with the intermediate layer 10, but the intermediate layer 10 may not be provided, and the absorbent article of the present invention is provided between the front surface sheet 3 and the back surface sheet 4. The structure may be such that the absorber 5 having the laminated structure 8 is arranged.
The absorbent article of the present invention is not limited to the deployable disposable diaper as in the above embodiment, and broadly includes an article used for absorbing body fluid (urine, menstrual blood, loose stool, sweat, etc.) discharged from the human body. It also includes pants-type disposable diapers, sanitary napkins, sanitary shorts, etc. that do not have a fastening structure such as the fastening member 18 and the fastening region 19.

Further, the following additional notes will be disclosed with respect to the above-described embodiment of the present invention.
<1>
It has a vertical direction corresponding to the front-back direction of the wearer and a horizontal direction orthogonal to the vertical direction, and includes an absorber that absorbs and holds body fluid, and a surface sheet arranged on the skin-facing surface side of the absorber. It is an absorbent article that
The surface sheet is located at the center of the absorbent article in the lateral direction, and has an uneven region having an uneven shape on the skin facing surface including a plurality of convex portions protruding toward the skin side of the wearer, and the uneven portion. It is located on both sides of the lateral direction of the region and is divided into non-concavo-convex regions having no uneven shape on the skin facing surface.
The absorber includes a sheet-type absorber in which a water-absorbent polymer is arranged between two base sheets arranged so as to face each other in the thickness direction.
The portion of the sheet-type absorber that overlaps the uneven region in a plan view has a larger basis weight of the water-absorbent polymer than the portion of the sheet-type absorber that overlaps the non-concave region in a plan view. ..
<2>
The convex portion of the uneven region includes a first convex portion and a second convex portion having a lower protrusion height or a smaller area than the first convex portion.
The concavo-convex region is located in the central portion of the concavo-convex region in the lateral direction, and is located on both sides of the first concavo-convex region in which the first concavo-convex portion is arranged and the first concavo-convex region in the lateral direction. It is divided into a second uneven region where the second convex portion is arranged, and is divided into a second uneven region.
The portion of the sheet-type absorber that overlaps the first uneven region in a plan view (corresponding to the first uneven region) is a portion that overlaps the second uneven region of the sheet-type absorber in a plan view (corresponding to the second uneven region). The basis weight of the water-absorbent polymer is larger than that of the part).
The portion of the sheet-type absorber that overlaps the second uneven region in a plan view (second uneven region corresponding portion) is a portion that overlaps the non-concave region in the sheet-type absorber in a plan view (non-concave region corresponding portion). The absorbent article according to <1>, wherein the water-absorbent polymer has a larger basis weight than that of the above-mentioned <1>.
<3>
2. The above-mentioned <2>, wherein an intermediate layer is arranged between the first uneven region and the portion of the sheet-type absorber that overlaps the first uneven region in a plan view (the portion corresponding to the first uneven region). Absorbent article.
<4>
The absorbent article according to <3>, wherein the basis weight of the intermediate layer is preferably 10 g / m ² or more and 100 g / m ² or less, and more preferably 15 g / m ² or more and 80 g / m ² or less.
<5>
The lateral length (width) of the first uneven region is preferably 15% or more with respect to the lateral length (minimum width) of the absorbent article.
The lateral length (width) of the second uneven region is preferably 10% or more, more preferably 15% or more, with respect to the lateral length (minimum width) of the absorbent article. ,
The lateral length (width) of the first concavo-convex region is longer than the lateral length (width) of the second concavo-convex region, and is set to any one of <2> to <4>. The absorbent article described.
<6>
The basis weight of the water-absorbent polymer in the portion of the sheet-type absorber that overlaps the first uneven region in plan view (the portion corresponding to the first uneven region) and the second uneven region of the sheet-type absorber overlap in plan view. The ratio of the portion (corresponding to the second uneven region) to the basis weight of the water-absorbent polymer is preferably 1.5 or more and 3.5 or less, and more preferably 1.7 or more and 3.0 or less as the former / the latter. ,
The basis weight of the water-absorbent polymer in the portion of the sheet-type absorber that overlaps the first uneven region in plan view (the portion corresponding to the first uneven region) is preferably 70 g / m ² or more and 150 g / m ² or less, more preferably. The absorbent article according to any one of <2> to <5>, which is 80 g / m ² or more and 120 g / m ² or less.

<7>
The absorber is arranged on the skin-facing surface side of the sheet-type absorber, and has a first layer in which a water-absorbent polymer is supported on a fiber stack of a fiber material, and a second layer made of the sheet-type absorber. The absorbent article according to any one of <2> to <6>, which has a laminated structure and the first layer is arranged so as to overlap the first uneven region in a plan view.
<8>
The above <7>, wherein in the laminated structure, the first layer has a larger basis weight of the water-absorbent polymer than the second layer and the density of the water-absorbent polymer is lower than that of the second layer. Absorbent article.
<9>
The basis weight of the water-absorbent polymer of the first layer constituting the laminated structure is preferably 55 g / m ² or more and 450 g / m ² or less, more preferably 70 g / m ² or more and 300 g / m ² or less.
The ratio of the basis weight of the water-absorbent polymer of the first layer to the basis weight of the water-absorbent polymer of the second layer is preferably 1.1 or more and 3.0 or less, more preferably 1.2 as the former / the latter. The absorbent article according to <7> or <8>, which is 2.5 or less.
<10>
In the surface sheet, two sheets are partially joined in a laminated state, and one of the two sheets, which is relatively close to the wearer's skin, is the other in a portion other than the joint. The absorbent article according to any one of <1> to <9>, which protrudes in a direction away from the sheet to form the convex portion.
<11>
The water-absorbent polymer-arranged layer in the sheet-type absorber does not contain the water-absorbent fiber material, or the content of the water-absorbent fiber material is preferably 10 with respect to the total mass of the water-absorbent polymer-arranged layer. The absorbent article according to any one of <1> to <10>, which is by mass% or less, more preferably 3% by mass or less.
<12>
The lateral length (width) of the uneven region is preferably 30% or more and 70% or less, more preferably 35% or more and 65, with respect to the lateral length (minimum width) of the absorbent article. % Or less, the absorbent article according to any one of <1> to <11>.
<13>
The lateral length (width) of the non-concavo-convex region is preferably 8% or more, more preferably 10% or more, with respect to the lateral length (minimum width) of the absorbent article. The absorbent article according to any one of <1> to <12>.
<14>
The basis weight of the water-absorbent polymer in the portion of the sheet-type absorber that overlaps the uneven region in a plan view (the portion corresponding to the uneven region) is 50 g / m ² or more and 150 g / m ² or less.
The basis weight of the water-absorbent polymer in the portion of the sheet-type absorber that overlaps the uneven region in a plan view (the portion corresponding to the uneven region) and the portion of the sheet-type absorber that overlaps the non-concavo-convex region in a plan view (non-concavo-convex region). The ratio of the corresponding part) to the basis weight of the water-absorbent polymer is preferably 2 or more and 30 or less, more preferably 5 or more and 25 or less as the former / the latter, in any one of <1> to <13>. The absorbent article described.
<15>
The absorbent article according to any one of <1> to <14>, wherein the absorbent article is a disposable diaper.

According to the present invention, an absorbent article having excellent liquid absorption performance and wearing feeling is provided.

Claims (15)

1. It has a vertical direction corresponding to the front-back direction of the wearer and a horizontal direction orthogonal to the vertical direction, and includes an absorber that absorbs and holds body fluid, and a surface sheet arranged on the skin-facing surface side of the absorber. It is an absorbent article that
   The surface sheet is located at the center of the absorbent article in the lateral direction, and has an uneven region having an uneven shape on the skin facing surface including a plurality of convex portions protruding toward the skin side of the wearer, and the uneven portion. It is located on both sides of the lateral direction of the region and is divided into non-concavo-convex regions having no uneven shape on the skin facing surface.
   The absorber includes a sheet-type absorber in which a water-absorbent polymer is arranged between two base sheets arranged so as to face each other in the thickness direction.
   The portion of the sheet-type absorber that overlaps the uneven region in a plan view has a larger basis weight of the water-absorbent polymer than the portion of the sheet-type absorber that overlaps the non-concave region in a plan view. ..
2. The convex portion of the uneven region includes a first convex portion and a second convex portion having a lower protrusion height or a smaller area than the first convex portion.
   The concavo-convex region is located in the central portion of the concavo-convex region in the lateral direction, and is located on both sides of the first concavo-convex region in which the first concavo-convex portion is arranged and the first concavo-convex region in the lateral direction. It is divided into a second uneven region where the second convex portion is arranged, and is divided into a second uneven region.
   The portion of the sheet-type absorber that overlaps the first concavo-convex region in a plan view has a larger basis weight of the water-absorbent polymer than the portion of the sheet-type absorber that overlaps the second concavo-convex region in a plan view.
   A portion of the sheet-type absorber that overlaps the second uneven region in a plan view has a larger basis weight of the water-absorbent polymer than a portion of the sheet-type absorber that overlaps the non-concave region in a plan view. Item 1. The absorbent article according to Item 1.
3. The absorbent article according to claim 2, wherein an intermediate layer is arranged between the first concavo-convex region and the portion of the sheet-type absorber that overlaps the first concavo-convex region in a plan view.
4. The absorbent article according to claim 3, wherein the basis weight of the intermediate layer is 10 g / m ² or more and 100 g / m ² or less.
5. The lateral length of the first uneven region is 15% or more with respect to the lateral length of the absorbent article.
   The lateral length of the second uneven region is 10% or more with respect to the lateral length of the absorbent article.
   The absorbent article according to any one of claims 2 to 4, wherein the lateral length of the first concavo-convex region is longer than the lateral length of the second concavo-convex region.
6. The basis weight of the water-absorbent polymer in the portion of the sheet-type absorber that overlaps with the first uneven region in plan view, and the basis weight of the water-absorbent polymer in the portion of the sheet-type absorber that overlaps with the second uneven region in plan view. The ratio of the former / the latter is 1.5 or more and 3.5 or less.
   According to any one of claims 2 to 5, the basis weight of the water-absorbent polymer in the portion of the sheet-type absorber that overlaps with the first uneven region in a plan view is 70 g / m ² or more and 150 g / m ² or less. The absorbent article described.
7. The absorber is arranged on the skin-facing surface side of the sheet-type absorber, and has a first layer in which a water-absorbent polymer is supported on a fiber stack of a fiber material, and a second layer made of the sheet-type absorber. The absorbent article according to any one of claims 2 to 6, which has a laminated structure, and the first layer is arranged so as to overlap the first uneven region in a plan view.
8. The absorption according to claim 7, wherein in the laminated structure, the first layer has a larger basis weight of the water-absorbent polymer than the second layer, and the density of the water-absorbent polymer is lower than that of the second layer. Sex goods.
9. The basis weight of the water-absorbent polymer of the first layer constituting the laminated structure is 55 g / m ² or more and 450 g / m ² or less.
   The ratio of the basis weight of the water-absorbent polymer of the first layer to the basis weight of the water-absorbent polymer of the second layer is 1.1 or more and 3.0 or less as the former / the latter, claim 7 or 8. Described absorbent article.
10. In the surface sheet, two sheets are partially joined in a laminated state, and one of the two sheets, which is relatively close to the wearer's skin, is the other in a portion other than the joint. The absorbent article according to any one of claims 1 to 9, wherein the convex portion is formed so as to project in a direction away from the sheet.
11. The water-absorbent polymer-arranged layer in the sheet-type absorber does not contain the water-absorbent fiber material, or the content of the water-absorbent fiber material is 10% by mass with respect to the total mass of the water-absorbent polymer-arranged layer. The absorbent article according to any one of claims 1 to 10 below.
12. The absorption according to any one of claims 1 to 11, wherein the lateral length of the uneven region is 30% or more and 70% or less with respect to the lateral length of the absorbent article. Sex goods.
13. The absorbent article according to any one of claims 1 to 12, wherein the lateral length of the non-concavo-convex region is 8% or more with respect to the lateral length of the absorbent article. ..
14. The basis weight of the water-absorbent polymer in the portion of the sheet-type absorber that overlaps the uneven region in a plan view is 50 g / m ² or more and 150 g / m ² or less.
    Ratio of the basis weight of the water-absorbent polymer in the portion of the sheet-type absorber that overlaps the uneven region in a plan view with the basis weight of the water-absorbent polymer in the portion of the sheet-type absorber that overlaps the non-concavo-convex region in a plan view. Is the absorbent article according to any one of claims 1 to 13, wherein is 2 or more and 30 or less as the former / the latter.
15. The absorbent article according to any one of claims 1 to 14, wherein the absorbent article is a disposable diaper.
    

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