JP6941512B2 - Absorbent article - Google Patents

Description

The present invention relates to absorbent articles such as disposable diapers.

As absorbent articles such as disposable diapers, generally, a liquid-permeable front sheet forming a skin-facing surface, a liquid-impermeable back sheet forming a non-skin facing surface, and an absorbent arranged between these two sheets. It is known that the absorbent body includes an absorbent core containing an absorbent material such as wood pulp or a water-absorbent polymer, and a core wrap sheet that covers the outer surface of the absorbent core.

The core wrap sheet functions as a sheet for receiving the absorbent material at the time of manufacturing the absorbent body, and plays a role of wrapping and shaping the absorbent core after manufacturing. As the core wrap sheet, a water-permeable sheet such as thin paper or absorbent paper is generally used. However, from the viewpoint of improving the strength of the absorbent body after absorbing body fluid, the applicant has first made a non-woven fabric water-permeable sheet. It has been proposed to use a sex sheet (Patent Document 1).

In Patent Document 1, a non-stacked fiber portion is provided in a liquid-retaining absorbent core, and in the non-stacked fiber portion, a skin-side core wrap sheet covering the absorbent core and a non-skin-side core wrap sheet are joined. An absorbent article comprising the absorber is described. Patent Document 1 describes that a hydrophilic non-woven fabric made of fibers that have been subjected to a hydrophilic treatment is used as the core wrap sheet.

Further, in Patent Document 2, the absorber included in the absorbent article has a squeezed portion compressed in the thickness direction, and the squeezed portion extends in the first inclined direction and the second inclined direction. An absorbent article comprising a second squeeze section is described. The first squeezed portion and the second squeezed portion of the absorber described in Patent Document 2 are formed alternately at intervals.

Japanese Unexamined Patent Publication No. 2016-83194 Japanese Unexamined Patent Publication No. 2014-100262

According to the absorbent article described in Patent Document 1, the shape-retaining property of the absorber is excellent, the absorber is not easily broken during wearing, and the usability is improved.

However, Patent Documents 1 and 2 do not describe anything about using a multilayer structure non-woven fabric for the core wrap sheet. Further, Patent Documents 1 and 2 do not describe anything about the ability to reduce the wetting of the skin and prevent the liquid from returning to the skin.

Therefore, the present invention is to provide an absorbent article capable of eliminating the above-mentioned drawbacks of the prior art.

The present invention comprises an absorber having a liquid-retaining absorbent core and a skin-side core wrap sheet that covers the skin-facing surface of the absorbent core, and liquid permeability arranged on the skin-facing surface side of the absorbent body. The surface sheet is provided, and has a vertical direction extending from the ventral side of the wearer to the back side through the crotch portion and a lateral direction orthogonal to the vertical direction, and extends to the lower crotch portion arranged in the crotch portion and the front and back thereof. An absorbent article comprising an existing ventral and dorsal portions, wherein the skin-side core wrap sheet is mainly composed of non-thermoplastic hydrophilic fibers arranged on the inner surface side in contact with the absorbent core. It is a laminated sheet having a hydrophilic fiber layer and a synthetic fiber layer arranged on the outer surface side in contact with the hydrophilic fiber layer and composed mainly of thermoplastic synthetic fibers, and the absorber is the skin. The side core wrap sheet has a recessed portion that bites into the absorbent core, and the skin side core wrap sheet has a liquid permeability in the recessed portion rather than a liquid permeability in a portion other than the recessed portion. It is also a highly absorbent article.

According to the present invention, there is provided an absorbent article in which the liquid diffusivity of a body fluid is improved, the wetness of the skin during wearing is reduced, and the liquid return prevention property to the skin is excellent.

FIG. 1 is a plan view schematically showing a skin-facing surface, that is, a surface sheet side of a deployable disposable diaper according to an embodiment of the absorbent article of the present invention, and the elastic members of each part are stretched and expanded in a plane shape. It is a plan view in the unfolded state. FIG. 2 is a cross-sectional view schematically showing a cross section taken along line II-II of FIG. FIG. 3 is a plan view of the absorber provided in the disposable diaper shown in FIG. FIG. 4 is a cross-sectional view schematically showing the IV-IV line cross section of FIG. FIG. 5 is a cross-sectional view schematically showing a cross section of the absorber provided with the disposable diaper shown in FIG. 1 along the thickness direction of the recessed portion. FIG. 6 is a plan view schematically showing another pattern of the recessed portion in the absorber according to the present invention.

Hereinafter, the absorbent article of the present invention will be described with reference to the drawings based on an example of a deployable disposable diaper which is a preferred embodiment thereof. 1 and 2 show the deployable disposable diaper 1 of the present embodiment. The diaper 1 is arranged on the skin-facing surface side of the absorber 4 having the liquid-retaining absorbent core 40 and the skin-side core wrap sheet 41U covering the skin-facing surface of the absorbent core 40, and the absorbent body 4. A liquid-permeable surface sheet 2 is provided. The diaper 1 includes a vertical direction X extending from the ventral side of the wearer to the dorsal side via the crotch portion and a lateral direction Y orthogonal to the vertical direction X, and extends to the inseam 1M arranged in the crotch portion and the front and back thereof. It includes an existing ventral portion 1F and a dorsal portion 1R. The ventral portion 1F, the inseam 1M, and the dorsal portion 1R correspond to each region when the diaper 1 is divided into three equal parts in the vertical direction X. The inseam 1M has an excretion portion facing portion that is arranged to face the excretion portion of the wearer's penis, anus, etc. when the diaper 1 is worn, and the excretion portion facing portion is usually in the vertical direction X of the diaper 1. It is located in or near the center. The thickness direction, which is a vertical direction orthogonal to the plane direction including the vertical direction X and the horizontal direction Y, will be described as the Z direction.

As shown in FIGS. 1 and 2, the diaper 1 is arranged on the skin facing surface side of the absorbent body 4 having the absorbent core 40 and the absorbent body 4, and is located closer to the wearer's skin than the absorbent body 4. A liquid-permeable surface sheet 2 that can come into contact with the wearer's skin when worn, and a liquid-free surface sheet 2 that is arranged on the non-skin facing surface side of the absorber 4 and is located farther from the wearer's skin than the absorber 4. It includes a permeable or water-repellent back sheet 3. In a plan view as shown in FIG. 1, the diaper 1 has a vertically long hourglass shape in which the central portion of the vertical direction X located at the inseam 1M is constricted inward and is long in one direction, that is, the vertical direction X. The front surface sheet 2 and the back surface sheet 3 each have a size larger than that of the absorber 4 interposed between the two sheets 2 and 3, and form the outer shape of the unfolded and stretched diaper 1 as shown in FIG. ing.

In the present specification, the "skin facing surface" is a surface of the absorbent article or its constituent members (for example, the absorbent core 40) that is directed toward the skin side of the wearer when the absorbent article is worn, that is, relatively. The side close to the wearer's skin, and the "non-skin facing surface" is the surface of the absorbent article or its constituent members that faces the opposite side (clothing side) of the absorbent article when the absorbent article is worn, that is, relative to the skin. It is the side far from the wearer's skin. In addition, "when worn" here means a state in which a normal proper wearing position is maintained.

A band-shaped elastic member 11 is formed between the front surface sheet 2 and the back surface sheet 3 at the waist portion of each of the ventral side portion 1F and the dorsal side portion 1R, that is, the end portion in the vertical direction X, which is an abbreviation of the lateral direction Y of the diaper 1. It is fixed in a laterally extended state over the entire length, whereby waist gathers are formed on the waist portion when the diaper 1 is worn due to the contraction of the elastic member 11. Further, a plurality of thread-like elastic members 12 are fixed in a laterally extended state between the front surface sheet 2 and the back surface sheet 3 in the waist circumference portion corresponding to the waist circumference of the wearer in the dorsal side portion 1R. As a result, gathers around the waist are formed by the contraction of the elastic member 12 around the waist when the diaper 1 is worn. Further, side sheets 5 are arranged on both the left and right sides along the vertical direction X on the surface sheet 2 side of the diaper 1, that is, the skin facing surface side. The side sheet 5 has an inner edge portion along the vertical direction X and an outer edge portion located outside the inner edge portion in the horizontal direction Y and along the vertical direction X, and has a plane as shown in FIG. In view, the inner edge portion overlaps with the absorber 4, and the outer edge portion extends outward in the lateral direction Y from the side edge of the absorber 4 along the vertical direction X, and as shown in FIG. 2, the back surface sheet. It is joined with 3. A thread-like elastic member 13 is fixed in an extended state along the vertical direction X between the side seat 5 and the back seat 3 in the left and right leg portions arranged around the wearer's legs. A pair of leg gathers are formed on the leg portion when the diaper 1 is worn due to the contraction of the elastic member 13. Further, a thread-like elastic member 14 is fixed to the inner edge portion of the side sheet 5 in an extended state along the vertical direction X, and the inner edge portion is at least 1M in the inseam, specifically, for example. The inseam 1M and the parts of the ventral 1F and the dorsal 1R near the inseam 1M are free ends that are not joined to the surface sheet 2 and other components of the diaper 1, and are ventral. The front and rear ends of the vertical direction X on the 1F and the dorsal side 1R are joined to the surface sheet 2 (not shown). Due to such a configuration of the side seat 5, when the diaper 1 is worn, the contraction force of the elastic member 14 acts in the vertical direction X, and the side seat 5 has at least the inner edge of the inseam 1M which is a free end. In, a pair of left and right leak-proof cuffs are formed by standing up toward the wearer's skin starting from the joint with the back surface sheet 3. The front surface sheet 2, the back surface sheet 3, the absorber 4, the side sheets 5, and the elastic members 11 to 14 are bonded to each other by a known bonding means such as a hot melt adhesive.

As shown in FIG. 1, a pair of fastening tapes 6 and 6 are provided on both side edges of the dorsal portion 1R of the diaper 1 along the vertical direction X. A fastening portion 61 made of a male member of a mechanical hook-and-loop fastener is attached to the fastening tape 6. Further, a landing region 7 made of a female member of a mechanical hook-and-loop fastener is formed on the non-skin facing surface of the ventral side 1F of the diaper 1. In the landing region 7, a female member of a mechanical hook-and-loop fastener is attached to the non-skin facing surface of the back surface sheet 3 forming the non-skin facing surface on the ventral side 1F by a known joining means such as an adhesive or a heat seal. It is formed by joining and fixing, and the fastening portion 61 of the fastening tape 6 can be detachably fastened.

As the surface sheet 2, various materials conventionally used for absorbent articles such as disposable diapers can be used without particular limitation, and it is assumed that the surface sheet 2 is a liquid permeable sheet capable of permeating body fluids such as urine and feces. As the material, a woven fabric made of synthetic fibers or natural fibers, a non-woven fabric, a porous sheet, or the like can be used. As an example of the surface sheet 2, a non-woven fabric made of a natural fiber such as cotton or a non-woven fabric made of various synthetic fibers subjected to a hydrophilic treatment can be used. For example, a core-sheath structure type (including side-by-side type) composite fiber using polypropylene or polyester as a core component and polyethylene as a sheath component is made into a web by carding, and then a non-woven fabric (after that, a hole is opened at a predetermined position) by an air-through method. Treatment may be applied). Further, from the viewpoint of high liquid permeability (dry feeling), a perforated sheet made of polyolefin such as low-density polyethylene can also be preferably used.
As the back sheet 3, various materials conventionally used for absorbent articles such as disposable diapers can be used without particular limitation, and liquid impermeable (including water repellency) and moisture permeable ones are preferable. Used. Specifically, in order to obtain sufficient water permeability, a film made of a synthetic resin such as polyethylene in which fine powder composed of a filler such as calcium carbonate is dispersed is stretched, and a porous film having fine pores is a back sheet. Can be suitably used as 3.
As the side sheet 5, a sheet that can be used as the back sheet 3 can be used.

As shown in FIGS. 2 and 3, the absorber 4 includes a liquid-retaining absorbent core 40 and a core wrap sheet 41 that covers the absorbent core 40. It is preferable that the absorbent core 40 and the core wrap sheet 41 are joined by a known joining means such as a hot melt adhesive. In the plan view as shown in FIGS. 1 and 3, the absorbent core 40 constituting the absorber 4 has an hourglass shape in which the central portion of the vertical direction X located at the inseam 1M is enclosed inward and is in the vertical direction X. It has a long vertically long shape.

The absorbent core 40 is mainly composed of an absorbent material, and the content of the absorbent material in the absorbent core 40 is usually about 100% by mass. As the absorbent material, various materials conventionally used for absorbent articles such as disposable diapers can be used without particular limitation. For example, cellulosic fibers such as wood pulp and synthetic fiber treated with a hydrophilic agent can be used. Such as hydrophilic fibers and water-absorbent polymers can be mentioned. As the structure of the absorbent core 40, a structure in which a hydrophilic fiber stack, a structure in which a water-absorbent polymer is supported on the fiber stack, or a structure consisting of only a water-absorbent polymer can be exemplified. ^{The basis weight of the absorbent core 40 is preferably 50 g / m 2} or more and 500 g / m ² or less, and 100 g / m ² or more and 450 g, from the viewpoint of suppressing discomfort when wearing the diaper 1 and improving the fit. It is more preferably / m ^{2 or less.}

In the diaper 1, the core wrap sheet 41 covers the skin-side core wrap sheet 41U that covers the skin-facing surface of the absorbent core 40 and the non-skin-facing surface of the absorbent core 40, as shown in FIGS. It has a non-skin side core wrap sheet 41D. The skin-side core wrap sheet 41U and the non-skin-side core wrap sheet 41D may be formed of different sheets, but in the diaper 1, they are formed of one core wrap sheet 41. Specifically, one core wrap sheet 41 has a length equal to or longer than the length of the absorbent core 40 in the vertical direction X in the vertical direction X, and as shown in FIG. 2 in the horizontal direction Y. The skin-facing surface of the absorbent core 40 is covered, and both side portions of the core wrap sheet 41 along the vertical direction X are caught in the non-skin facing surface side of the absorbent core 40, so that the non-skin facing surface of the absorbent core 40 is non-skinned. The absorbent core 40 is wrapped so as to overlap at the center of the lateral Y on the facing surface. In one core wrap sheet 41 that wraps the absorbent core 40 in this way, the sheet portion that covers the skin facing surface of the absorbent core 40 becomes the skin side core wrap sheet 41U, and the non-skin facing surface of the absorbent core 40. The sheet portion covering the skin is the non-skin side core wrap sheet 41D.

As shown in FIGS. 2 and 3, the skin-side core wrap sheet 41U and the non-skin-side core wrap sheet 41D are arranged on the inner surface side in contact with the absorbent core 40 and have non-thermoplastic hydrophilic fibers 45, respectively. It is a laminated sheet having a hydrophilic fiber layer 43 configured as a main body and a synthetic fiber layer 42 arranged on the outer surface side in contact with the hydrophilic fiber layer 43 and mainly composed of a thermoplastic synthetic fiber 44. FIG. 4 shows an absorbent core 40, a skin-side core wrap sheet 41U arranged on the skin-facing surface side of the absorbent core 40, and a non-skin-side core arranged on the non-skin-facing surface side of the absorbent core 40. A cross section along the thickness direction (Z direction) with the wrap sheet 41D is shown.

The synthetic fiber layer 42 is mainly composed of a thermoplastic synthetic fiber 44, and the hydrophilic fiber layer 43 is mainly composed of a non-thermoplastic hydrophilic fiber 45. The synthetic fiber layer 42 contains at least 80% by mass or more of the thermoplastic synthetic fiber 44, and the content of the thermoplastic synthetic fiber 44 may be 100% by mass with respect to the total mass of the synthetic fiber layer 42. Further, the hydrophilic fiber layer 43 may contain at least 80% by mass or more of the hydrophilic fiber 45, and the content of the hydrophilic fiber 45 may be 100% by mass with respect to the total mass of the hydrophilic fiber layer 43.

As shown in FIG. 4, the skin-side core wrap sheet 41U is relatively close to the wearer's skin, and is relatively close to the wearer's skin with the synthetic fiber layer 42 arranged on the outer surface side of the absorbent core 40. It is configured to include a laminated structure (two-layer structure) with the hydrophilic fiber layer 43 on the inner surface side which is far away and abuts on the absorbent core 40. The synthetic fiber layer 42 of the skin-side core wrap sheet 41U is arranged to face the surface sheet 2, and the hydrophilic fiber layer 43 is arranged to face the absorbent core 40. The synthetic fiber layer 42 and the hydrophilic fiber layer 43 are integrated at least via a recessed portion 8 described later, and depending on the manufacturing method, the constituent fibers of both layers 42 and 43 are further entangled with each other, and an adhesive or the like is used. It can also be integrated by other integrating means such as joining means.

As shown in FIG. 4, the non-skin side core wrap sheet 41D is relatively far from the wearer's skin and is relative to the wearer's skin with the synthetic fiber layer 42 arranged on the outer surface side of the absorbent core 40. It is configured to include a laminated structure (two-layer structure) with the hydrophilic fiber layer 43 on the inner surface side that is in contact with the absorbent core 40. The synthetic fiber layer 42 of the non-skin side core wrap sheet 41D is arranged to face the back surface sheet 3, and the hydrophilic fiber layer 43 is arranged to face the absorbent core 40. Depending on the production method, the synthetic fiber layer 42 and the hydrophilic fiber layer 43 may be further integrated by an integrating means such as entanglement of the constituent fibers of both layers 42 and 43 and a joining means such as an adhesive.

In the core wrap sheet 41 of the diaper 1, the synthetic fiber layer 42 and the hydrophilic fiber layer 43 are both fiber aggregates. The form of such a fiber aggregate is not particularly limited, and examples thereof include non-woven fabric, woven fabric, and paper. In a typical form, the synthetic fiber layer 42 is a non-woven fabric and the hydrophilic fiber layer 43 is paper. In FIGS. 4 and 5, from the viewpoint of facilitating understanding, the thermoplastic synthetic fiber 44 is indicated by a relatively thin line, and the non-thermoplastic hydrophilic fiber 45 is indicated by a relatively thick line. It has nothing to do with the actual fiber thickness.

The skin-side core wrap sheet 41U and the non-skin-side core wrap sheet 41D are each composed of a non-woven fabric constituting the synthetic fiber layer 42. As the non-woven fabric constituting the synthetic fiber layer 42, those produced by various manufacturing methods can be used without particular limitation, and examples thereof include spunbonded non-woven fabrics, melt-blown non-woven fabrics, spunbond-melt-blown-spunbond non-woven fabrics, and air-through non-woven fabrics. , Spun lace non-woven fabric, resin bond non-woven fabric, needle punch non-woven fabric and the like. It is also possible to use a laminated body in which two or more kinds of these non-woven fabrics are combined, or a laminated body in which these non-woven fabrics and a film or the like are combined. Among these non-woven fabrics, the spunbonded non-woven fabric and the spunbond-melt blown-spunbonded non-woven fabric have an effect of preventing leakage of an absorbent material such as a water-absorbing polymer contained in the absorbent core 40 as compared with an air-through non-woven fabric or the like. It is preferable because it is excellent in. From the same viewpoint, the average interfiber distance of the spunbonded non-woven fabric or the spunbond-melt blown-spunbond (SMS) non-woven fabric is preferably 10 μm or more, more preferably 20 μm or more, and preferably 200 μm or less, further preferably 180 μm. It is as follows. The average interfiber distance is measured by the following method. The average interfiber distance of the skin-side core wrap sheet 41U is measured at a portion other than the recessed portion 8 (embossed compartment region ET which is a non-recessed portion).

<Method of measuring the average interfiber distance of the non-woven fabric constituting the synthetic fiber layer 42>
The average interfiber distance of a fiber aggregate such as a non-woven fabric or paper is calculated by the following formula (1) based on the assumption of Wrotnowski. The following formula (1) is generally used when determining the interfiber distance of a fiber aggregate. Under Wrotnowski's assumptions, the fibers are columnar and the fibers are regularly arranged without intersecting.
Sheet to be measured (skin side core wrap sheet 41U or non-skin side core wrap sheet 41D)
When is a single-layer structure, the average interfiber distance of the sheet having the single-layer structure is calculated by the following formula (1).
When the sheet to be measured has a multi-layer structure such as SMS non-woven fabric, the average interfiber distance of the multi-layer structure sheet is determined according to the following procedure.
First, the average interfiber distance of each layer constituting the multilayer structure is calculated by the following formula (1). At that time, the thickness t, the basis weight W, the fiber density ρ, and the fiber diameter D used in the following formula (1) are those for the layer to be measured, respectively, and the thickness t is the thickness direction of the layer to be measured. Measure by microscopic observation of the cross section along. The thickness t, the basis weight W, and the fiber diameter D are average values of the measured values at a plurality of measurement points, respectively. The basis weight W (g / m ² ) is obtained by cutting a sheet to be measured to a predetermined size, measuring the weight, and then dividing the weight measurement value by an area obtained from the predetermined size. Fiber density ρ (g / cm ³ ) is JIS using a density gradient tube.
Measure according to the measurement method of the density gradient tube method described in the L1015 chemical fiber staple test method (URL is http://kikakurui.com/l/L1015-2010-01.html, JIS handbook fiber-2000 for books, (Description on pages 764 to 765 of the Japanese Standards Association). For the fiber diameter D (μm), 10 fiber cross sections of the cut fibers are measured using a scanning electron microscope (DSC6200 manufactured by Seiko Instruments Co., Ltd.), and the average value thereof is taken as the fiber diameter.
Next, the average interfiber distance of each layer is multiplied by the ratio of the thickness of the layer to the total thickness of the multilayer structure, and the numerical values for each layer thus obtained are totaled to obtain the desired multilayer structure. The average interfiber distance of the constituent fibers of the sheet is obtained. For example, in an SMS non-woven fabric having a three-layer structure composed of two S layers and one M layer, the two S layers are collectively treated as one layer, and the thickness t of the entire three-layer structure is 0.11 mm. When the thickness t of the S layer is 0.1 mm, the average interfiber distance LS of the S layer is 47.8 μm, the thickness t of the M layer is 0.01 mm, and the average interfiber distance LS of the M layer is 3.2 μm. The average interfiber distance between the constituent fibers of the SMS non-woven fabric is 43.8 μm [= (47.9 × 0.1 + 3.2 × 0.01) /0.11].

The preferred skin-side core wrap sheet 41U and non-skin-side core wrap sheet 41D include a synthetic fiber layer 42 made of a spunbonded non-woven fabric or an SMS non-woven fabric having an average interfiber distance within the above range, and the synthetic fiber layer. The thermoplastic synthetic fiber 44, which is the main constituent fiber of 42, and the non-thermal hydrophilic fiber 45 such as wood pulp are entangled with each other. If the average interfiber distance of the synthetic fiber layer 42 is too small, the interfiber voids become too narrow, and it may be difficult to secure continuity in the thickness direction of the hydrophilic fibers 45 in the synthetic fiber layer 42. As a result, in the skin-side core wrap sheet 41U and the non-skin-side core wrap sheet 41D, the hydrophilic fibers 45 may be difficult to continue from the skin-facing surface side to the non-skin-facing surface side of the synthetic fiber layer 42. .. Further, if the average interfiber distance of the synthetic fiber layer 42 is too large, the effect of the skin-side core wrap sheet 41U and the non-skin-side core wrap sheet 41D on preventing leakage of the absorbent material from the absorbent core 40 is reduced. In particular, when a water-absorbent polymer having a small particle size is used as the absorbent material, the particles may leak to the outside.

The reason why the spunbonded non-woven fabric or the SMS non-woven fabric is used as the synthetic fiber layer 42 of the skin-side core wrap sheet 41U and the non-skin-side core wrap sheet 41D is to achieve both the strength suitable for the core wrap sheet 41 and the interfiber distance. be. Examples of the thermoplastic synthetic fiber 44, which is the main constituent fiber of these non-woven fabrics, include synthetic fibers that have been or have not been hydrophilized (for example, polypropylene fibers). The basis weight of the synthetic fiber layer 42 of the respective skin-side core wrap sheets 41U and non-skin side core wrap sheet 41D is preferably 5 g / m ² or more, more preferably 7 g / m ² or more, and preferably 30 g / m ² Below, it is more preferably 15 g / m ² or less.

As the thermoplastic resin which is the material of the thermoplastic synthetic fiber 44, those usually used for constituent fibers such as non-woven fabrics can be used without particular limitation. For example, polyethylene, polypropylene, polybutene-1, polypentene-1, and polypentene-1, And polyolefins such as these random or block copolymers; polyesters such as polyethylene terephthalate and polybutylene terephthalate; polyamides such as nylon-6 and nylon-66. The thermoplastic synthetic fiber 44 may be a single fiber formed by using a single thermoplastic resin, or may be a composite fiber formed by using two or more kinds of thermoplastic resins. Examples of the composite fiber include core-sheath type fiber, side-by-side type fiber, split type fiber, alternating arrangement type fiber, and sea-island type fiber. The synthetic fiber layer 42 may contain two or more types of thermoplastic synthetic fibers 44. Among these, polyethylene and polypropylene have a relatively low melting point, and therefore are preferably used as the thermoplastic synthetic fiber 44 when they are integrated by embossing through the recessed portion 8 described later.

The skin-side core wrap sheet 41U and the non-skin-side core wrap sheet 41D are made into absorbent articles on the premise that they do not have thermoplasticity as non-thermoplastic hydrophilic fibers 45 constituting the hydrophilic fiber layer 43, respectively. Various conventionally used hydrophilic fibers can be used without particular limitation, and typical ones are cellulose fibers. Examples of the cellulose fiber include wood pulp such as coniferous kraft pulp and broadleaf kraft pulp, natural cellulose fiber such as cotton pulp and non-wood pulp such as walla pulp; and regenerated cellulose fiber such as rayon and cupra, and one of them. Can be used alone or in combination of two or more.
Among these, wood pulp is most preferable from the viewpoint that it is easily exposed to the surface through the gaps between the thermoplastic synthetic fibers 44 constituting the synthetic fiber layer 42 because the fiber length of wood pulp is shorter than that of regenerated cellulose or non-wood pulp. Used.

Of the skin-side core wrap sheet 41U and the non-skin-side core wrap sheet 41D, at least the skin-side core wrap sheet 41U comprises the non-thermoplastic hydrophilic fibers 45 constituting the hydrophilic fiber layer 43 and the absorbent core 40. It is preferable that both the hydrophilic fibers contained in the absorbent material are wood pulp fibers. As described above, cellulose fibers are highly hydrophilic, and among them, wood pulp fibers have a shorter fiber length than non-wood pulp and regenerated cellulose fibers. Of the skin-side core wrap sheet 41U and the non-skin-side core wrap sheet 41D, the wood pulp fibers constitute at least the hydrophilic fibers 45 constituting the hydrophilic fiber layer 43 of the skin-side core wrap sheet 41U and the absorbent core 40. By using it for both of the hydrophilic fibers contained in the absorbent material, it is easy to take a structure in which the hydrophilic fibers in the absorbent core 40 enter between the fibers of the hydrophilic fiber layer 43, and the contact points of the fibers with each other can be easily formed. Easy to do. As a result, the body fluid taken in from the skin side can be smoothly transmitted to the absorbent core 40.

In diaper 1, in each of the skin side core wrap sheet 41U and the non-skin side core wrap sheet 41D, the body liquid once absorbed by the absorbent core 40 is a surface sheet formed by the synthetic fiber layer 42 arranged on the outer surface side of the absorbent core 40. From the viewpoint of preventing the synthetic fiber layer 42 from returning to the second side, the hydrophilicity of the thermoplastic synthetic fiber 44 constituting the synthetic fiber layer 42 is higher than the hydrophilicity of the non-thermoplastic hydrophilic fiber 45 constituting the hydrophilic fiber layer 43. Is also preferably low. Further, from the viewpoint of improving the utilization efficiency of the absorbent core 40 by diffusing the body fluid in the hydrophilic fiber layer 43 arranged to face the absorbent core 40, the non-thermoplastic hydrophilic fiber 45 constituting the hydrophilic fiber layer 43 is formed. Is preferably higher in hydrophilicity than the hydrophilicity of the thermoplastic synthetic fiber 44 constituting the synthetic fiber layer 42.

In the present invention, the hydrophilicity of the fiber is determined based on the contact angle with water measured by the following method, and if the contact angle is less than 90 degrees, it is hydrophilic, and if it is 90 degrees or more, it is hydrophobic. be. The smaller the contact angle with water measured by the following method, the higher the hydrophilicity (lower hydrophobicity), and the larger the contact angle, the lower the hydrophilicity (higher hydrophobicity). In the core wrap sheet 41, the contact angle of the non-thermoplastic hydrophilic fiber 45, which is the main component of the hydrophilic fiber layer 43, with water is less than 90 degrees, and the thermoplastic synthetic fiber 44, which is the main body of the synthetic fiber layer 42, has a contact angle of less than 90 degrees. The contact angle with water is preferably 90 degrees or more.

<Measurement method of contact angle>
The fibers are taken out from the measurement target (skin side core wrap sheet 41U or non-skin side core wrap sheet 41D), and the contact angle of water with respect to the fibers is measured. As a measuring device, an automatic contact angle meter MCA-J manufactured by Kyowa Interface Science Co., Ltd. is used. Distilled water is used to measure the contact angle. The amount of liquid discharged from the inkjet water droplet discharge unit (Pulse injector CTC-25 manufactured by Cluster Technology Co., Ltd., having a discharge unit hole diameter of 25 μm) is set to 20 picolitres, and the water droplet is dropped directly above the fiber. The state of dripping is recorded on a high-speed recording device connected to a horizontally installed camera. From the viewpoint of image analysis later, the recording device is preferably a personal computer incorporating a high-speed capture device. In this measurement, an image is recorded every 17 msec. In the recorded video, the first image of water droplets on the fibers is the attached software FAMAS (software version is 2.6.2, analysis method is droplet method, analysis method is θ / 2 method, image processing algorithm. Is non-reflective, image processing image mode is frame, threshold level is 200, curvature correction is not performed), the angle between the surface of the water droplet in contact with the air and the fiber is calculated, and the contact is made. Make a corner. The fiber taken out from the object to be measured is cut into a fiber length of 1 mm, and the fiber is placed on a sample table of a contact angle meter and maintained horizontally. Measure the contact angles at two different points for each fiber. The contact angle of N = 5 fibers is measured to one digit after the decimal point, and the average value of the measured values at 10 points in total (rounded to the second digit after the decimal point) is defined as the contact angle of the fiber with water. The measurement environment is room temperature 22 ± 2 ° C. and humidity 65 ± 2% RH.

When the constituent member (for example, the core wrap sheet 41) is taken out from the absorbent article and evaluated and measured, if the constituent member is fixed to another constituent member by an adhesive, fusion, or the like, the constituent member is fixed to another constituent member. The fixed portion is removed by applying a solvent, blowing hot air with a dryer, blowing a cold spray (for example, a commercially available product manufactured by Nichiban Co., Ltd.), and then taking out the fixed portion.

In the skin-side core wrap sheet 41U, the liquid permeability in the recessed portion 8 described later is higher than the liquid permeability in the portion other than the recessed portion 8 (the embossed partition region ET which is the non-recessed portion). Whether or not the liquid permeability in the recessed portion 8 is higher than the liquid permeability in the portion other than the recessed portion 8 can be determined from the water droplet disappearance rate measured by the following method for measuring the water droplet disappearance rate. The ratio of the water droplet disappearance rate in the recessed portion 8 and the water droplet disappearance rate in the portion other than the recessed portion 8 measured by the following method for measuring the water droplet disappearance rate is based on the premise that the former is larger than the latter. As the latter, 1.
It is twice or more, more preferably three times or more. The water droplet disappearance rate of the recess 8 is preferably 60% or more, more preferably 80% or more, and the upper limit is 100%.
The water droplet disappearance rate of the portion other than the recess 8 is preferably 50% or less, more preferably 30% or less, and the lower limit is 0%.
If the difference in the water droplet disappearance rate between the recessed portion 8 and the portion other than the recessed portion 8 is 10% or more, it is considered that the transparency is high.

<Measuring method of water droplet disappearance rate in the recessed portion 8 and the portion other than the recessed portion 8>
Sheet to be evaluated (skin side core wrap sheet 4 including recessed portion 8 or portion other than recessed portion 8)
1U) is fixed in the air so that the synthetic fiber layer 42 faces up and is horizontal. Then, water droplets (1 drop 2 μl) of physiological saline (saline solution having a concentration of 0.9% by mass) are dropped onto 20 locations on the recessed portion 8 or 20 locations other than the recessed portion 8 using a microsyringe. do. If the hydrophilicity of the dropped portion of the sheet to be evaluated is high, the water droplets are immediately absorbed by the sheet and disappear after the dropping, and if the hydrophilicity of the dropped portion is low, the water droplets are not absorbed and are not absorbed on the upper surface of the sheet. It remains. The disappearance of the water droplets is determined by visually observing the upper surface of the sheet 10 seconds after the water droplets are dropped. The water droplet disappearance rate (%) is obtained by calculating the ratio of the water droplet disappearance points within 10 seconds out of the measurement at 20 points.

In the diaper 1, the absorber 4 has a recessed portion 8 in which the skin-side core wrap sheet 41U bites into the inside of the absorbent core 40. The recessed portion 8 is formed by embossing the synthetic fiber layer 42 on the outer surface side and the hydrophilic fiber layer 43 on the inner surface side, which constitute the skin-side core wrap sheet 41U, in order to melt and integrate them by applying heat. An embossed portion widely formed by embossing, such as one formed by pressing the synthetic fiber layer 42 and the hydrophilic fiber layer 43 without applying heat and performing embossing to press and integrate them. It is a meaning that includes. In the diaper 1, the recessed portion 8 absorbs the non-thermoplastic hydrophilic fibers 45 through the synthetic fiber layer 42 on the skin facing surface side by plasticizing the synthetic fiber layer 42 on the skin facing surface side by heat. From the viewpoint of being easily exposed to the skin-facing surface side of the body 4, the body 4 is formed by applying heat and embossing in order to fuse and combine / integrate. In the diaper 1, the absorbent body 4 is embossed from the skin-facing surface side to the non-skin-facing surface side, and the skin side having the synthetic fiber layer 42 and the hydrophilic fiber layer 43 up to the inside of the absorbent core 40. The core wrap sheet 41U is made to bite into the recessed portion 8. In the recessed portion 8, the synthetic fiber layer 42 of the skin-side core wrap sheet 41U is melted and integrally joined with the hydrophilic fiber layer 43.

When the hydrophilic fiber layer 43 contains a hydrophilic thermoplastic synthetic fiber (not shown), the hydrophilic thermoplastic synthetic fiber (not shown) includes the thermoplastic synthetic fiber 44 which is the main component of the synthetic fiber layer 42 described above. It is possible to use a fiber made of the same material as the above, to which a hydrophilic agent usually used for a constituent fiber such as a non-woven fabric is added. The hydrophilicity of the hydrophilic thermoplastic synthetic fiber (not shown) may be lower than the hydrophilicity of the non-thermoplastic hydrophilic fiber 45 constituting the hydrophilic fiber layer 43, but constitutes the synthetic fiber layer 42. It is preferable that the hydrophilicity of the thermoplastic synthetic fiber 44 is higher than that of the thermoplastic synthetic fiber 44.

In the diaper 1, a plurality of recessed portions 8 are arranged on the skin-facing surface of the absorber 4. The recessed portion 8 may be arranged in a dot shape intermittently, for example, but it is preferable that the recessed portion 8 is arranged in a continuous line such as a straight line, a wavy line, or a curved line. In the diaper 1, as shown in FIGS. 1 and 3, the absorber 4 is viewed in a plan view, and the recessed portion 8 is formed into a plurality of continuous lines so as to have an angle with respect to each of the vertical direction X and the horizontal direction Y. It is formed. The recessed portions 8 formed in a plurality of continuous lines form an intersecting portion 8k that intersects with each other. Preferably, an intersection 8k is formed at an intersection where the recesses 8 formed in a plurality of continuous lines intersect with each other, and a plurality of non-embossed portions surrounded by the recesses 8 of the continuous lines intersecting with each other. The embossed compartment area ET is formed. That is, in the diaper 1, the liquid permeability in the embossed partition region ET is lower than the liquid permeability in the recessed portion 8, and the liquid permeability is high so as to surround the entire circumference of the embossed compartment region ET. The recessed portion 8 is arranged. By arranging the recessed portion 8 in this way, even if the body fluid is discharged onto the embossed compartment region ET having low liquid permeability and flows on the embossed compartment region ET, the liquid permeability around the embossed compartment region ET is high. Body fluid can be absorbed by the recessed portion 8 and leakage can be prevented. From the viewpoint of preventing such leakage, it is preferable to arrange the recessed portion 8 so as to surround the entire circumference of the embossed partition region ET.

As described above, the recessed portion 8 is easy to permeate the body fluid, and the permeation of the body fluid discharged from the wearer to the absorbent core 40 is higher than that of the embossed compartment area ET, and at the same time, it is absorbent. The body fluid absorbed by the core 40 easily permeates in the direction of returning to the wearer's skin. From the viewpoint of facilitating the permeation of body fluid into the absorbent core 40, the ratio of the area (S1) of the recessed portion 8 to the surface area (S0) of the absorber 4 ((S1 / S0) × 100) is 10% or more. It is preferably 15% or more, more preferably 15% or less, and preferably 40% or less, and 35% or less, from the viewpoint of preventing the body fluid absorbed by the absorbent core 40 from returning to the wearer side. From the viewpoint of both, it is more preferably 10% or more and 40% or less, and further preferably 20% or more and 35% or less.
The surface area (S0) of the absorber 4 referred to here means the area of the entire absorber 4 when the absorbent core 40 covered with the core wrap sheet 41 is viewed in a plan view, and the area of the recessed portion 8 (S1). ) Means the total surface area of the bottom of all the recesses 8 when the absorbent core 40 covered with the core wrap sheet 41 is viewed in a plan view. It is assumed that the surface area (S0) of the absorber 4 includes the area (S1) of the recessed portion 8.

In the diaper 1, the concave portions 8 of the continuous lines having angles with respect to the vertical direction X and the horizontal direction Y are preferably parallel to each other and parallel to a large number of first concave portions 81 arranged at predetermined intervals. It also has a large number of second recessed portions 82 formed at predetermined intervals, and as shown in FIG. 3, the first recessed portion 81 and the second recessed portion 82 form an angle α with each other. It intersects. More preferably, in the diaper 1, the groove width W1 of the first recessed portion 81 (see FIG. 3) and the groove width of the second recessed portion 82 are the same, and the distance W2 between the adjacent first recessed portions 81, 81 is the same. The distance between the second recessed portions 82 and 82 adjacent to each other (see FIG. 3) is the same.

The groove width W1 of the first recessed portion 81 (groove width of the second recessed portion 82) (see FIG. 3) is preferably 0.5 mm or more from the viewpoint of facilitating the permeation of body fluid into the absorbent core. It is more preferably 1 mm or more, and from the viewpoint of preventing the body fluid in the absorbent core from returning to the wearer side, it is more preferably 3 mm or less, further preferably 2 mm or less, and specifically. Is preferably 0.5 mm or more and 3 mm or less, and more preferably 1 mm or more and 2 mm or less.

Further, narrowing the distance W2 between the first recessed portions 81 and 81 (distance between the second recessed portions 82 and 82) (see FIG. 3) causes the body fluid to be discharged onto the embossed compartment region ET having low liquid permeability. Therefore, assuming that the fluid has flowed over the embossed compartment region ET, it is preferable from the viewpoint of shortening the flow distance of the body fluid to prevent leakage, while narrowing this interval W2 is a depression formed as a continuous line at the same time. This increases the number of parts 8 and is unsuitable from the viewpoint of making it difficult for the body fluid absorbed in the absorbent core 40 to return to the wearer's skin. From the viewpoint of the balance between the two, the distance W2 is preferably 5 mm or more, more preferably 15 mm or more, more preferably 40 mm or less, further preferably 20 mm or less, and more specifically. Specifically, it is preferably 5 mm or more and 40 mm or less, and more preferably 15 mm or more and 20 mm or less.

Further, in the diaper 1, the absorber 4 has a shape short in the horizontal direction Y and long in the vertical direction X, and particularly in the inseam 1M near the excretory part of the wearer, the shape is constricted inward in the horizontal direction Y. The length (width) of the horizontal direction Y is the smallest. Therefore, from the viewpoint of preventing leakage of body fluid, it is necessary to suppress the liquid flow in the horizontal direction Y rather than the vertical direction X. From such a viewpoint, the angle (angle α) (see FIG. 3) formed by the first recessed portion 81 and the second recessed portion 82 is preferably 90 ° or less, and more preferably 60 ° or less. .. On the other hand, making this angle α too small also increases the number of recessed portions 8 formed as continuous lines, and from the viewpoint of making it difficult for the body fluid in the absorbent core 40 to return to the wearer's skin. It becomes unsuitable. From this point of view, the angle α is preferably 15 ° or more, and more preferably 30 ° or more.

The recessed portion 8 having the first recessed portion 81 and the second recessed portion 82 in the absorber 4 of the diaper 1 is formed on the peripheral surface of a metallic cylindrical roller such as an aluminum alloy or steel, and the first recessed portion 81 is provided. A heat seal device including a heat seal roller having a convex portion corresponding to the second concave portion 82, or a peripheral surface of a metallic cylindrical roller corresponding to the first concave portion 81 and the second concave portion 82. It can be formed by using a device including a pattern roller having a convex portion and an ultrasonic horn.

In the recessed portion 8 of the absorber 4 of the diaper 1, as shown in FIG. 5, the non-thermoplastic hydrophilic fibers 45 constituting the hydrophilic fiber layer 43 in the skin-side core wrap sheet 41U are formed on the outer surface side of the synthetic fiber layer 42. It passes through and is exposed on the skin-facing surface side of the absorber 4. Preferably, the recessed portion 8 is a portion where the skin-side core wrap sheet 41U is compacted in the thickness direction to the extent that the skin-side core wrap sheet 41U bites into the inside of the absorbent core 40. It is carried out by embossing (squeezing) with a melting promoting means for promoting melting of the thermoplastic synthetic fiber 44 such as. When the skin-side core wrap sheet 41U is squeezed with such a melting promoting means, the outer surface of the skin-side core wrap sheet 41U is viewed from the viewpoint of promoting the melting of the thermoplastic synthetic fibers 44 constituting the skin-side core wrap sheet 41U. It is preferable to apply the squeezing to the synthetic fiber layer 42 on the side. The recessed portion 8 has narrower interfiber gaps or substantially existing interfiber gaps as compared with the portion of the skin-side core wrap sheet 41U other than the recessed portion 8 (embossed partition region ET which is a non-recessed portion). It is a high-density portion that is not formed, and the non-recessed portion is a low-density portion having a wider interfiber gap than the recessed portion 8.

In the diaper 1, as described above, in each recessed portion 8, as shown in FIG. 5, the non-thermoplastic hydrophilic fiber 45 constituting the skin-side core wrap sheet 41U passes through the synthetic fiber layer 42 on the outer surface side. It is exposed on the skin-facing surface side of the absorber 4. Then, the hydrophilic fiber layer 43 of the skin-side core wrap sheet 41U and the absorbent core 40 are in contact with each other. Therefore, the hydrophilic fibers 45 exposed on the skin-facing surface side of the absorber 4 and the hydrophilic fibers of the absorbent material of the absorbent core 40 pass through the synthetic fiber layer 42 of the skin-side core wrap sheet 41U and are connected. ing. In each recessed portion 8, it is confirmed whether or not the hydrophilic fiber 45 on the skin side core wrap sheet 41U side passes through the synthetic fiber layer 42 and is exposed on the skin facing surface side of the absorber 4. It can be carried out by microscopic observation of a cross section along the thickness direction (Z direction), and specifically, it can be carried out by the following method.

<Method of confirming that the non-thermoplastic hydrophilic fiber 45 passes through the synthetic fiber layer 42 and is exposed on the skin-facing surface side of the absorber 4 in the recessed portion 8>
Immerse the sheet to be evaluated (skin-side core wrap sheet 41U) in a 0.5% by mass blue aqueous solution (Edible Blue No. 1 of Aizen Food Color manufactured by Daiwa Kasei), allow it to stand for 3 minutes, and then remove the sheet from the aqueous solution. Place the removed sheet on a pre-laid paper (Kim Towel, manufactured by Nippon Paper Crecia Co., Ltd.) with the skin-facing side facing down, and dehydrate the sheet from above with a load of 3 kPa over 1 minute. do. By this operation, the hydrophilic fibers among the constituent fibers of the evaluation target sheet are dyed. The concave portion 8 to be evaluated of the dyed sheet thus obtained is cut along the lateral direction Y of the diaper 1 using a single-edged razor manufactured by Feather, and the cut surface thereof is cut with a microscope (VHX-1000 manufactured by KEYENCE). ) Is observed at a magnification of 200 to 500 times, and the non-thermoplastic hydrophilic fiber 45 which is the main component of the hydrophilic fiber layer 43 on the non-skin facing surface side is exposed on the skin facing surface side of the recess 8. Check if it is done. Since the hydrophilic fibers 45 are dyed in the recessed portion 8, it is easy to determine whether or not the recessed portion 8 is exposed on the skin-facing surface side.

As described above, the recessed portion 8 is typically formed by embossing with heat, ultrasonic waves, or the like, and the synthetic fiber layer of the skin-side core wrap sheet 41U of the recessed portion 8 formed by such embossing. In 42, the thermoplastic synthetic fiber 44, which is the main component thereof, is softened and melted by heat and ultrasonic waves during embossing, so that the original form of the fiber aggregate is lost and the fiber is formed into a film. A part of the non-thermoplastic hydrophilic fiber 45, which is the main component of the hydrophilic fiber layer 43, enters the film-formed synthetic fiber layer 42 of the recessed portion 8 (the fiber form is lost), and is an absorber. It is exposed on the side facing the skin of No. 4. That is, in the recessed portion 8, one or more exposed portions of the hydrophilic fibers 45 are present in the synthetic fiber layer 42 formed into a film with the skin-facing surface side of the absorber 4 viewed in a plan view. The hydrophilic fibers 45 forming the exposed portion pass through the synthetic fiber layer 42 and are continuous from the skin-facing surface side to the non-skin-facing surface side of the skin-side core wrap sheet 41U.

In the diaper 1, in the recessed portion 8 of the absorber 4, a space K is formed between the surface sheet 2 and the absorber 4. Preferably, in the diaper 1, the surface sheet 2 arranged adjacent to the skin facing surface side of the absorber 4 does not enter the recessed portion 8 of the absorber 4, and as shown in FIG. 4, the recessed portion In No. 8, a space K is formed between the non-skin facing surface of the surface sheet 2 and the skin facing surface of the recessed portion 8 of the absorber 4. The space K is formed in a plan view of the diaper 1 as shown in FIG. 3 and corresponds to the shape pattern of the recessed portion 8 having the first recessed portion 81 and the second recessed portion 82.
Further, in such a structure, after forming the recessed portion 8 in the absorber 4, an adhesive is applied to a portion of the absorber 4 on the side opposite to the skin excluding at least the recessed portion 8, and then the surface sheet 2 is absorbed. It can be formed by a step of sticking it on the skin-opposing side of the body 4. The adhesive is preferably a hot melt adhesive. The method of applying the adhesive is not particularly limited, but a method of applying by contacting the coater gun of the contact type coater coating machine with the portion of the absorber 4 excluding the recessed portion 8 on the side opposite to the skin is preferable. A surface coating pattern, a stripe coating pattern, or the like is applied to the coating pattern on the coater coating machine, but the stripe coating pattern is more preferable because the adhesive does not hinder the permeation of body fluids.

As described above, in the diaper 1, as shown in FIGS. 2 to 4, the absorbent core 40 constituting the absorber 4 is covered with the skin-side core wrap sheet 41U, and the skin-side core wrap sheet 41U is formed. A hydrophilic fiber layer 43 arranged on the inner surface side in contact with the absorbent core 40 and mainly composed of non-thermoplastic hydrophilic fibers 45, and an outer surface side in contact with the hydrophilic fiber layer 43 and thermoplastic. It is formed of a laminated sheet having a synthetic fiber layer 42 composed mainly of synthetic fibers 44. The absorber 4 has a recessed portion 8 in which the skin-side core wrap sheet 41U bites into the inside of the absorbent core 40, and the skin-side core wrap sheet 41U has a recessed liquid permeability in the recessed portion 8. It is higher than the liquid permeability in the portion other than the portion 8 (the embossed partition region ET which is a non-embossed portion surrounded by the recessed portion 8). Therefore, the body fluid is easily absorbed from the recessed portion 8 of the skin-side core wrap sheet 41U into the inside of the absorbent core 40 during wearing. At that time, the body fluid is easily transmitted in the surface direction through the hydrophilic fiber layer 43 on the absorbent core 40 side in the skin-side core wrap sheet 41U, the liquid diffusivity is improved, the utilization efficiency of the absorbent body 4 is improved, and the body fluid is worn. It is possible to reduce the wetting of the skin inside.
Further, since the skin-side core wrap sheet 41U located in the recessed portion 8 bites into the inside of the absorbent core 40, the body fluid returns to the absorbent core 40 via the recessed portion 8 because the distance from the surface sheet is increased. The absorbed body fluid is hard to return to the skin, and it has excellent anti-return property to the skin.

Further, in the diaper 1, the liquid permeability of the recessed portion 8 is higher than that of the portion other than the recessed portion 8, and the body fluid is easily absorbed into the absorbent core 40, and at the same time, the inside of the absorbent core 40 is absorbed. It is easy for the body fluid in the body to return to the wearer's side. However, the recessed portion 8 bites into the inside of the absorbent core 40, and the recessed portion 8 is farther from the wearer's skin than the portion other than the recessed portion 8, so that the wearer's skin Wetting can be reduced. Further, in the recessed portion 8, the surface sheet 2 is arranged so that a space K is formed between the non-skin facing surface of the surface sheet 2 and the skin facing surface of the recessed portion 8 of the absorber 4, so that the surface sheet 2 is arranged during wearing. The wearer's skin does not come close to the recessed portion, and from this point of view, the wearer's skin can be reduced from getting wet.
Further, if the hydrophilicity of the thermoplastic synthetic fiber 44 of the synthetic fiber layer 42 is lower than the hydrophilicity of the non-thermoplastic hydrophilic fiber 45, the body liquid once absorbed by the absorber 4 corresponds to the hydrophilic fiber layer 43. The synthetic fiber layer 42 arranged on the outer surface side in contact makes it more difficult for the wearer to return to the skin side, has excellent liquid return prevention properties, and improves the usability of the diaper 1.

Further, in the diaper 1, as shown in FIG. 5, in each recessed portion 8, the non-thermoplastic hydrophilic fiber 45 of the skin-side core wrap sheet 41U passes through the synthetic fiber layer 42 on the outer surface side to the skin of the absorber 4. The hydrophilic fiber layer 43 on the inner surface side of the skin side core wrap sheet 41U is exposed to the facing surface side and is in contact with the absorbent core 40. Therefore, in each recessed portion 8, the hydrophilic fiber 45 exposed on the skin-facing surface side of the absorber 4 easily functions as a fluid passage (liquid passage trigger) for the body fluid, and the absorber 4 located in the recessed portion 8 The body fluid on the surface facing the skin diffuses into the hydrophilic fiber layer 43 through the recessed portion 8 (exposed portion of the hydrophilic fiber 45) and is easily taken into the absorbent core 40. In particular, in the diaper 1, the recessed portions 8 formed in a plurality of continuous lines are arranged so as to form an intersecting portion 8k that intersects with each other. Therefore, it is easily taken into the absorbent core 40 via the intersection 8k.

Further, in the diaper 1, as shown in FIG. 2, the skin side core wrap sheet 41U and the non-skin side core wrap sheet 41D are formed of one core wrap sheet 41 including the synthetic fiber layer 42 made of non-woven fabric. .. Therefore, the shape-retaining property of the absorber 4 during wearing is excellent, the absorber 4 is not easily broken during wearing, and the usability is improved.

From the viewpoint of further exerting the above-mentioned effects, the diaper 1 preferably has one or more of the following configurations.

When 10 arbitrarily selected from the plurality of recessed portions 8 existing in the absorber 4, the skin-facing surface side of the absorber 4, in other words, the skin-facing surface side of the recessed portion 8, in the 10 recessed portions 8. Percentage of the recessed portion (hereinafter, also referred to as "hydrophilic portion exposed recessed portion") in which the non-thermoplastic hydrophilic fiber 45 (the constituent fiber of the hydrophilic fiber layer 43 of the skin side core wrap sheet 41U) is exposed. That is, the value calculated by "(the number of exposed recessed portions of the hydrophilic portion / 10) x 100" is preferably 50% or more, and more preferably 80% or more.
Whether or not a certain recess is an exposed hydrophilic recess is confirmed by the following method. That is, with respect to the recessed portion to be evaluated, it is confirmed by the above method whether or not the fibers (hydrophilic fibers 45) of the hydrophilic fiber layer 43 are exposed on the skin-facing surface side of the recessed portion, and the fibers of such a recessed portion are examined. If the exposure can be confirmed at even one place, the recessed portion is assumed to be the hydrophilic portion exposed recessed portion.
When the recessed portion 8 is a continuous line, 10 mm of the continuous line of the recessed portion 8 is defined as one recessed portion, and any 10 locations are selected so as not to overlap.

In the skin-side core wrap sheet 41U, the synthetic fiber layer 42 has a lower hydrophilicity than the hydrophilic fiber layer 43 in the portion other than the recessed portion 8 (embossed compartment region ET), in other words, the hydrophilic fiber layer 43. Is preferably more hydrophilic than the synthetic fiber layer 42. The hydrophilicity of the sheet (layer) referred to here is evaluated by the water droplet disappearance rate measured by the following method. The smaller the value of the water droplet disappearance rate, the lower the hydrophilicity, and the larger the value of the water droplet disappearance rate, the higher the hydrophilicity. Therefore, it is preferable that the magnitude relationship of "water droplet disappearance rate of the synthetic fiber layer 42 <water droplet disappearance rate of the hydrophilic fiber layer 43" is established.

<Measurement method of water droplet disappearance rate of core wrap sheet or its synthetic fiber layer or hydrophilic fiber layer>
The sheet to be evaluated (for example, the skin-side core wrap sheet 41U or its synthetic fiber layer 42 or the hydrophilic fiber layer 43) is fixed in the air so that the surface becomes horizontal, and is placed at any 20 positions on the upper surface of the sheet. Water droplets (1 drop 2 μl) of physiological saline (saline solution having a concentration of 0.9% by mass) are dropped using a microsyringe. If the hydrophilicity of the sheet to be evaluated is high, the water droplets are immediately absorbed by the sheet and disappear after dropping, and if the hydrophilicity of the sheet is low, the water droplets are not absorbed and remain on the upper surface of the sheet. The disappearance of the water droplets is determined by visually observing the upper surface of the sheet 10 seconds after the water droplets are dropped. The water droplet disappearance rate (%) was measured at 20 points.
It is calculated by calculating the percentage of places where water droplets have disappeared within 10 seconds.

The ratio of the water droplet disappearance rate of the portion of the synthetic fiber layer 42 other than the recessed portion 8 to the water droplet disappearance rate of the portion of the hydrophilic fiber layer 43 other than the recessed portion 8 is based on the premise that the former is smaller than the latter. The latter is preferably 0.5 or less, more preferably 0.3 or less.
The water droplet disappearance rate of the portion of the synthetic fiber layer 42 other than the recessed portion 8 is preferably 0% or more, more preferably 20% or more, and preferably 80% or less, still more preferably 50% or less.
The water droplet disappearance rate of the portion of the hydrophilic fiber layer 43 other than the recessed portion 8 is preferably 50% or more, more preferably 80% or more.
The adjustment of the water droplet number disappearance rate, that is, the adjustment of the hydrophilicity, is performed on the types of the constituent fibers (thermoplastic synthetic fibers 44) of the synthetic fiber layer 42 and the constituent fibers (hydrophilic fibers 45) of the hydrophilic fiber layer 43, and the hydrophobizing agent (hydrophilic fiber 45). It can be carried out mainly by using a synthetic fiber layer 42) or a hydrophilizing agent (mainly for the hydrophilic fiber layer 43).

The absorbent core 40 constituting the absorbent body 4 is composed of the water-absorbent polymer and the cellulosic fiber in the diaper 1, and the mass ratio of the water-absorbent polymer and the cellulosic fiber is as the former: the latter. It is preferably 40:60 to 70:30, and more preferably 50:50 to 60:40.

In a more preferable form of the diaper 1, the basis weight of the water-absorbing polymer in the absorbent core 40 in the region corresponding to the recess 8 is such that the basis weight of the water-absorbing polymer in the region corresponding to the recess 8 is the water-absorbing polymer in the absorbent core 40 in the region other than the recess 8. Less than the basis weight of. When the absorbent core 40 absorbs the body fluid, the water-absorbent polymer contained therein swells, and the absorbent core 40 increases in thickness in the Z direction (thickness direction). The amount of this increase in thickness depends on the basis weight of the water-absorbent polymer. When the basis weight of the water-absorbent polymer in the absorbent core 40 in the region corresponding to the recess 8 is smaller than the basis weight of the water-absorbent polymer in the absorbent core 40 in the region corresponding to the region other than the recess 8. The amount of increase in the thickness of the recessed portion 8 is suppressed to be smaller than the amount of increase in the thickness of the portion other than the recessed portion 8, and even after the body fluid is absorbed, the recessed portion 8 is compared with the portion other than the recessed portion 8. The state of biting into the absorbent core 40 can be maintained. The recessed portion 8 having high liquid permeability bites into the absorbent core 40, and further, a space K is formed between the non-skin facing surface of the surface sheet 2 and the skin facing surface of the recessed portion 8 of the absorber 4. The effect of the configuration in which the surface sheet 2 is arranged is as described above, but from the viewpoint that this effect can be maintained even after the body fluid is absorbed, the basis weight of the water-absorbing polymer in the absorbent core 40 at the portion corresponding to the recessed portion 8 It is preferable that the structure is smaller than the basis weight of the water-absorbent polymer in the absorbent core 40 at the portion corresponding to the portion other than the recessed portion 8.
Here, the recessed portion 8 of the absorbent core 40 and the portion of the water-absorbent polymer having a small basis weight do not have to completely coincide with each other, and have the total area of the recessed portion 8 when the absorbent core 40 is viewed in a plan view. On the other hand, the area where the portion having a low polymer content and the recessed portion 8 overlap may be 50% or more, more preferably 75% or more. The most preferable form is that the shape pattern of the recessed portion 8 when the absorbent core 40 is viewed in a plan view is bordered, and a portion having a shape pattern including the recessed portion 8 and having a low polymer content is arranged. That is, when the pattern of the recessed portion 8 is a continuous line, the basis weight of the water-absorbing polymer is a shape pattern in which the continuous line is arranged at a position corresponding to the recessed portion 8 and the width of the continuous line is wider than that of the recessed portion. It is a form in which a small number of parts are arranged. With such a form, the above-mentioned effect can be further enhanced.
In this form, the width of the continuous line in the direction orthogonal to the longitudinal direction of the recessed portion 8 is substantially the same as the width of the portion where the basis weight of the water-absorbent polymer is smaller than the width of the recessed portion 8. It is preferably wider than the width of the recess 8, more preferably 3 mm or more, and even more preferably 5 mm or more. On the other hand, if the width of the portion where the basis weight of the water-absorbing polymer is small is widened, the absorption capacity of the entire absorbent core 40 will be reduced, and there is a concern that body fluids are likely to leak. From this point of view, the area of the portion where the basis weight of the water-absorbing polymer is small when the absorbent core 40 is viewed in a plan view is preferably 50% or less, more preferably 40% or less with respect to the total area of the absorbent core 40. preferable.
The method for producing the absorbent core 40 in the above-described form is not particularly limited, but for example, after the hydrophilic fibers and the water-absorbing polymer are uniformly mixed and stacked, in the next step, a place other than the recess 8 is formed. A method of spraying a water-absorbent polymer in a pattern can be mentioned.

Further, in the absorbent core 40 of the diaper 1, the basis weight of the portion having less water-absorbing polymer is preferably 70% or less, more preferably 70% or less, when the basis weight of the other portion is 100%. Is less than 50%.
The amount of the water-absorbent polymer contained in the absorbent core 40 can be determined from the ratio of the amount of the sodium ion contained in the water-absorbent polymer by quantifying the sodium ions by means such as ICP emission analysis, but water absorption. As a simpler means of determining the ratio of the polymer basis weight in the portion where the sex polymer is low to the polymer basis weight in the other region, the absorbent core 40 of each portion is cut out in the same area and their centrifugal retention amounts are compared. It is also possible to substitute it sufficiently. The centrifugal retention amount can be measured by the following measuring method.

<Measurement method of centrifugal retention amount>
The centrifugal holding amount (water absorption amount) is measured in accordance with JIS K 7223 (1996). Nylon woven cloth (sold by Sanriki Seisakusho, product name: nylon net, standard: 250 mesh) is cut into a rectangle with a width of 10 cm and a length of 40 cm, folded in half at the center in the longitudinal direction, and both ends are heat-sealed to a width of 10 cm. (Inner size 9 cm), make a nylon bag with a length of 20 cm. Then, the measurement sample is placed in the prepared nylon bag. Next, the nylon bag containing the sample is immersed in physiological saline (0.9 mass% sodium chloride aqueous solution) whose temperature is adjusted to 25 ° C. Then, one hour after the start of immersion, the nylon bag is taken out of the physiological saline solution, hung vertically for one hour to drain water, and then dehydrated using a centrifugal dehydrator (manufactured by Kokusan Co., Ltd., model H-130C special type). The dehydration condition is 143 G (800 rpm) for 10 minutes. After dehydration, the mass of the sample is measured, and the target centrifugal holding amount (water absorption amount) is calculated according to the following formula.
Centrifugal retention (g) = (a'-bc)
In the formula, a'is the total mass (g) of the sample and the nylon bag after centrifugal dehydration, b is the mass (g) of the nylon bag before water absorption (during drying), and c is the mass of the sample before water absorption (during drying). Represents (g). The measurement is performed 5 times (n = 5), the values at each of the upper and lower points are deleted, and the average value of the remaining 3 points is used as the measured value. The measurement is performed at 23 ± 2 ° C. and humidity of 50 ± 5%, and the sample is stored in the same environment for 24 hours or more before the measurement.

Further, from the viewpoint of promoting the diffusion of body fluid such as urine in the vertical direction X, the skin-side core wrap sheet 41U has the non-thermoplastic hydrophilic fiber 45, which is the main component of the hydrophilic fiber layer 43, in the vertical direction X. It is preferably oriented.

The total area of the absorbent body 4 recess 8 formed in is preferably 750 mm ² or more, more preferably 1500 mm ² or more, and, preferably 6000 mm ² or less, more preferably 5000 mm ² or less.

In the recessed portion 8 of the absorber 4, the density of the absorbent core 40 is preferably higher than the density of the portion of the absorbent core 40 other than the recessed portion 8. The density is calculated by using the basis weight and thickness obtained based on the measurement method described later.
In the recessed portion 8 of the absorber 4, it is preferable that the basis weight of the absorbent core 40 is the same as the basis weight of the portion of the absorbent core 40 other than the recessed portion 8. The basis weight of the absorbent core 40 in the recess 8 and the basis weight of the absorbent core 40 other than the recess 8 are preferably 200 g / m ² or more, more preferably 400 g / m ² or more, and preferably 400 g / m 2 or more. It is 800 g / m ² or less, more preferably 500 g / m ² or less. The basis weight of the absorbent core 40 is measured by the following measuring method.
In the recessed portion 8 of the absorber 4, the thickness of the absorbent core 40 is preferably smaller than the thickness of the portion of the absorbent core 40 other than the recessed portion 8. The thickness of the recessed portion 8 of the absorbent core 40 is preferably 0.5 mm or more, more preferably 1.0 mm or more, and preferably 4 mm or less, still more preferably 2.0 mm or less. The thickness of the absorbent core 40 other than the recessed portion 8 is preferably 2.0 mm or more, more preferably 3.0 mm or more, and preferably 5.0 mm or less, still more preferably 4.0 mm or less. The thickness of the absorbent core 40 is measured by the following measuring method.

<Measurement method of basis weight of absorbent core 40>
The absorber 4 is cut along the boundary line between the recessed portion 8 and the portion other than the recessed portion 8 (embossed partition area ET) using a feather razor, and a small piece of the recessed portion 8 in the absorber 4 and a small piece of the recessed portion 8 are formed. Obtain a small piece of a portion of the absorber 4 other than the recessed portion 8. Cut out these small pieces so that they have a predetermined area. A small piece of the absorbent core 40 located in the recessed portion 8 and a portion other than the recessed portion 8 are made so that only the portion of the absorbent core 40 is formed by removing the portion such as the core wrap sheet 41 from the cut-out small piece. Obtain a small piece of the absorbent core 40 located at. Next, the weight of the small piece of the absorbent core 40 located in the recessed portion 8 and the weight of the small piece of the absorbent core 40 located in the portion other than the recessed portion 8 are measured by an electronic balance (electronic balance GR-300 manufactured by A & D Co., Ltd.). Accuracy: Measure using 4 digits after the decimal point). The calculated weight is divided by the predetermined area to calculate the basis weight of the small piece. The average basis weight of 5 small pieces is defined as the basis weight for each of the recessed portion 8 of the absorbent core 40 and the portion other than the recessed portion 8 of the absorbent core 40.

<Measuring method of thickness of absorbent core 40>
The thickness of the recessed portion 8 of the absorbent core 40 and the thickness of the portion other than the recessed portion 8 of the absorbent core 40 were measured by cutting out the recessed portion 8 of the absorber 4 to measure the basis weight for each portion. This is performed by measuring using a small piece of the above and a small piece of a portion of the absorber 4 other than the recessed portion 8. Place an acrylic plate with a size of 20 mm x 20 mm and a thickness of 3 mm so that the center coincides with the center of the small piece, and observe the cut surface at a magnification of 20 to 100 times using a microscope (VHX-1000 manufactured by KEYENCE). Then, the thickness from the boundary between the portion of the absorbent core 40 and the portion of the core wrap sheet 41 or the like other than the absorbent core 40 is measured. The pressure at the time of thickness measurement is 0.5 g / cm ² (= 0.05 kPa) (= 0.05 kPa).

The depth of the absorber 4 at the recess 8 is preferably 15% or more of the thickness of the absorbent core from the viewpoint of preventing the return of the body fluid in the absorbent core. From the viewpoint of high liquid permeability, it is preferably 80% or less of the thickness of the absorbent core. The depth at the recess 8 is measured by the following measuring method.

<Measurement method of depth at recess 8>
The depth at the recessed portion 8 is determined by cutting the absorber 4 over the entire width of the recessed portion 8 using a single-edged razor manufactured by Feather Co., Ltd. and observing the cut surface of the cut small piece. Place an acrylic plate with a size of 20 mm x 20 mm and a thickness of 3 mm so that the center coincides with the center of the small piece, and observe the cut surface at a magnification of 20 to 100 times using a microscope (VHX-1000 manufactured by KEYENCE). Then, the distance from the boundary between the portion of the absorbent core 40 and the portion such as the core wrap sheet 41 other than the absorbent core 40 to the bottom surface of the recessed portion 8 is measured as the depth. The pressure at the time of depth measurement is 0.5 g / cm ² .

In the skin-side core wrap sheet 41U, it is preferable that the fiber diameters of the thermoplastic synthetic fiber 44 and the non-thermoplastic hydrophilic fiber 45 are both small. Since the fiber diameter of the thermoplastic synthetic fiber 44, which is the main component of the synthetic fiber layer 42, is relatively small, the fiber 44 is more likely to be melted and deformed due to compaction, and the absorber 4 is on the skin-facing surface side. The exposure of the hydrophilic fibers 45 is more likely to occur, and the fiber diameter of the hydrophilic fibers 45, which is the main component of the hydrophilic fiber layer 43, is relatively small, so that such exposure of the fibers 45 is more likely to occur. From the above points, the fineness of the thermoplastic synthetic fiber 44 is preferably 0.7 dtex or more, more preferably 1.0 dtex or more, and preferably 4.4 dtex or less, still more preferably 2.2 dtex or less. Further, the thickness of the non-thermoplastic hydrophilic fiber 45, that is, the diameter when the cross-sectional shape in the direction orthogonal to the length direction of the hydrophilic fiber 45 is circular, and the long axis when the cross-sectional shape is elliptical or flat. The length is preferably 50 μm or less, more preferably 30 μm or less, respectively.

Further, with respect to the non-thermoplastic hydrophilic fiber 45, the cross section of the hydrophilic fiber 45 is a perfect circle or a circular shape close to it, so that the absorber 4 is more reliably exposed on the skin-facing surface side. Is preferable.

Further, the basis weight of the synthetic fiber layer 42 is preferably relatively small. When the basis weight of the synthetic fiber layer 42 becomes excessive, the film formation of the synthetic fiber layer 42 (thermoplastic synthetic fiber 44) in the recessed portion 8 is excessively promoted, and as a result, the skin-facing surface side of the recessed portion 8 is formed into a film. The fiber layer 42 may completely block the non-thermoplastic hydrophilic fibers 45, making it difficult for the non-thermoplastic hydrophilic fibers 45 to be exposed on the skin-facing surface side of the absorber 4. In view of the above, the basis weight of the synthetic fiber layer 42 is preferably 5 g / m ² or more, more preferably 10 g / m ² or more, and preferably 20 g / m ²
Below, it is more preferably 15 g / m ² or less.

The skin-side core wrap sheet 41U is a hydrophilic fiber layer 43 in which the raw fabric sheet of the synthetic fiber layer 42 (typically, a non-woven fabric mainly composed of the thermoplastic synthetic fiber 44) and the raw fabric sheet are separate. It may be a laminated body in which a raw fabric sheet (typically, paper mainly composed of non-thermoplastic hydrophilic fibers 45) is laminated. The above-mentioned absorber 4 covers the absorbent core 40 with the skin-side core wrap sheet 41U made of such a laminated body, and heat, ultrasonic waves, or the like is applied to the planned formation portion of the recessed portion 8. It can be produced by performing embossing (squeezing) with a melting promoting means for promoting melting of the plastic synthetic fiber 44. By this embossing, the thermoplastic synthetic fiber 44 in the raw fabric sheet of the synthetic fiber layer 42 on the outer surface side is melted, deformed and formed into a film, and the hydrophilic fiber in the raw fabric sheet of the hydrophilic fiber layer 43 on the inner surface side is formed. 45 is easily exposed to the surface side of the filmed portion. In the absorber 4 manufactured by such a method, the embossed portion becomes the recessed portion 8, and the synthetic fiber layer 42 and the hydrophilic fiber layer 43 are joined and integrated via the recessed portion 8. There is. When the skin-side core wrap sheet 41U formed of a laminate composed of two raw fabric sheets is used as described above, the basis weight of the hydrophilic fiber layer 43 is preferably from the viewpoint of maintaining the form as paper. It is 10 g / m ² or more, more preferably 13 g / m ² or more, and preferably 30 g / m ² or less, still more preferably 20 g / m ² or less.

The skin-side core wrap sheet 41U is produced by a known wet papermaking method using a raw sheet of the synthetic fiber layer 42, a paper slurry containing a non-thermoplastic hydrophilic fiber 45, and a papermaking net. It may be a sheet. Specifically, first, the raw sheet of the synthetic fiber layer 42 is placed on the papermaking net. Next, a paper slurry containing the hydrophilic fibers 45 is poured into the raw sheet on the papermaking net. The water in the poured paper material slurry sequentially permeates the raw fabric sheet and the papermaking net and flows down from below the papermaking net, and the hydrophilic fibers 45 in the paper material slurry are the constituent fibers (heat) of the raw fabric sheet. It is entangled with the plastic synthetic fiber 44) and stays in the raw sheet, whereby a wet sheet having a two-layer structure containing the hydrophilic fiber 45 and the thermoplastic synthetic fiber 44 is formed on the papermaking net. A suction means may be arranged on the opposite side of the papermaking net from the raw fabric sheet, and the suction means may promote dehydration of the raw fabric sheet. Then, by drying this wet sheet by various drying means adopted in the wet papermaking method, the target skin-side core wrap sheet 41U is manufactured. The above-mentioned absorber 4 covers the absorbent core 40 with the skin-side core wrap sheet 41U manufactured in this manner, and is thermoplastic such as heat and ultrasonic waves to the planned formation portion of the recessed portion 8. It can be produced by performing embossing (squeezing) with a melting promoting means for promoting melting of the synthetic fiber 44. In the absorber 4 manufactured by such a method, the embossed portion becomes the recessed portion 8, and the synthetic fiber layer 42 and the hydrophilic fiber layer 43 are integrated with the recessed portion 8 in addition to the recessed portion 8. , Both fibers 44, 45 are also entangled.

In the skin-side core wrap sheet 41U manufactured by such a wet papermaking method, usually, the surface side of the raw fabric sheet facing the papermaking net, the so-called wire surface side (the side opposite to the supply side of the paper material slurry). Since the non-thermoplastic hydrophilic fibers 45 are unevenly distributed in, the wire surface side becomes the hydrophilic fiber layer 43. The distribution state of the hydrophilic fibers 45 on the skin-side core wrap sheet 41U can be adjusted by appropriately adjusting the pore diameter and pitch of the dehydration holes of the papermaking net. In particular, when the paper slurry containing the hydrophilic fibers 45 is poured into the raw fabric sheet and then a high-pressure water stream is sprayed onto the felt surface side of the raw fabric sheet, the recessed portion 8 formed by the subsequent embossing is formed. This is preferable because the hydrophilic fibers 45 are easily exposed on the skin-facing surface side or the non-skin-facing surface side of the absorber 4.

Although the present invention has been described above based on the embodiment, the present invention can be appropriately modified without being limited to the embodiment.

For example, in the diaper 1, when viewed in a plan view as shown in FIGS. 1 and 3, the recessed portion 8 is a continuous line having an angle with respect to the vertical direction X and the horizontal direction Y, and the first recessed portion 81 and the second recessed portion 81 and the second. Although they are arranged in a pattern that forms an intersecting portion 8k by the recessed portion 82, the intersecting portion 8k may be formed by another pattern. For example, the recessed portion 8 shown in FIG. 6 has a plurality of third recessed portions 83 extending continuously in parallel with the vertical direction X, and a plurality of fourth recessed portions 84 extending continuously in parallel with the horizontal direction Y. ing. In the absorber 4 shown in FIG. 6, the third recessed portions 83 extending continuously in parallel with the vertical direction X are arranged at equal intervals in the horizontal direction Y and continuously extend in parallel with the horizontal direction Y. The fourth recessed portions 84 are arranged at equal intervals in the vertical direction X to form intersecting portions 8k that intersect at right angles. The disposable diaper provided with the absorber 4 shown in FIG. 6 also has the same effect as that of the diaper 1 described above.

Further, the core wrap sheet 41 of the diaper 1 is composed of one sheet as shown in FIG. 2, but the skin-facing surface side of the absorbent core 40 is covered with the skin-side core wrap sheet 41U, and the absorbent core 40 is not. The skin-facing surface side may be covered with a second non-skin-side core wrap sheet 41D different from the skin-side core wrap sheet 41U to wrap the absorbent core 40. When the skin side core wrap sheet 41U and the non-skin side core wrap sheet 41D are separate bodies, the non-skin side core wrap sheet 41D may be the same as or different from the skin side core wrap sheet 41U in terms of its composition and material. good.

Further, from the viewpoint of improving absorbency and leakage resistance, liquid permeability made of paper or various non-woven fabrics, which is also called a sublayer or the like, is formed between the surface sheet 2 and the absorber 4 (skin side core wrap sheet 41U). Sheets may be intervened. From the same viewpoint, a groove formed by integrally compacting the surface sheet 2 and the absorber 4 may be formed on the skin-facing surface of the diaper 1.

In addition, the absorbent article of the present invention is not limited to the deployable disposable diaper, but includes a wide range of articles used for absorbing body fluids (urine, loose stool, menstrual blood, sweat, etc.) discharged from the human body, and is a pants type. Disposable diapers, sanitary napkins, sanitary shorts and the like are also included.

1 Deployable disposable diaper (absorbent article)
2 Front sheet 3 Back sheet 4 Absorber 40 Absorbent core 41 Core wrap sheet 41U Skin side core wrap sheet 41D Non-skin side core wrap sheet 42 Synthetic fiber layer 43 Hydrophilic fiber layer 44 Thermoplastic synthetic fiber 45 Non-thermoplastic hydrophilic Synthetic fiber 8 Concave part 81 1st concave part 82 2nd concave part 83 3rd concave part 84 4th concave part 8k Crossing part 1F Ventral part 1M Crotch part 1R Back side X Vertical direction Y Horizontal direction K Space

Claims (4)

An absorber having a liquid-retaining absorbent core and a skin-side core wrap sheet covering the skin-facing surface of the absorbent core, and a liquid-permeable surface sheet arranged on the skin-facing surface side of the absorber. It is provided and has a vertical direction extending from the ventral side of the wearer to the dorsal side via the crotch portion and a lateral direction orthogonal to the vertical direction, and the crotch portion arranged in the crotch portion and the ventral side extending in front of and behind the crotch portion. An absorbent article having a portion and a dorsal portion.
The skin-side core wrap sheet has a hydrophilic fiber layer arranged on the inner surface side in contact with the absorbent core and mainly composed of non-thermoplastic hydrophilic fibers, and an outer surface side in contact with the hydrophilic fiber layer. It is a laminated sheet having a synthetic fiber layer mainly composed of thermoplastic synthetic fibers arranged in the water.
The absorber has a recessed portion in which the skin-side core wrap sheet bites into the inside of the absorbent core.
In the recessed portion of the absorber, a space is formed between the surface sheet and the absorber.
The skin-side core wrap sheet is an absorbent article in which the liquid permeability in the recessed portion is higher than the liquid permeability in the portion other than the recessed portion. An absorber having a liquid-retaining absorbent core and a skin-side core wrap sheet covering the skin-facing surface of the absorbent core, and a liquid-permeable surface sheet arranged on the skin-facing surface side of the absorber. It is provided and has a vertical direction extending from the ventral side of the wearer to the dorsal side via the crotch portion and a lateral direction orthogonal to the vertical direction, and the crotch portion arranged in the crotch portion and the ventral side extending in front of and behind the crotch portion. An absorbent article having a portion and a dorsal portion.
The skin-side core wrap sheet has a hydrophilic fiber layer arranged on the inner surface side in contact with the absorbent core and mainly composed of non-thermoplastic hydrophilic fibers, and an outer surface side in contact with the hydrophilic fiber layer. It is a laminated sheet having a synthetic fiber layer mainly composed of thermoplastic synthetic fibers arranged in the water.
The hydrophilicity of the thermoplastic synthetic fiber constituting the skin-side core wrap sheet is lower than that of the non-thermoplastic hydrophilic fiber.
The absorber has a recessed portion in which the skin-side core wrap sheet bites into the inside of the absorbent core.
In the recessed portion, the non-thermoplastic hydrophilic fibers constituting the hydrophilic fiber layer in the skin-side core wrap sheet pass through the synthetic fiber layer on the outer surface side and are exposed on the skin-facing surface side of the absorber. And
The skin-side core wrap sheet is an absorbent article in which the liquid permeability in the recessed portion is higher than the liquid permeability in the portion other than the recessed portion. Claim 1 or 2 in which the non-thermoplastic hydrophilic fiber constituting the skin-side core wrap sheet and the hydrophilic fiber contained in the absorbent material constituting the absorbent core are both wood pulp fibers. Absorbent article described in. The absorbent article according to any one of claims 1 to 3 , wherein in the recessed portion of the absorber, the density of the absorbent core is higher than the density of the portion of the absorbent core other than the recessed portion. ..

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