JP2019042401A - Absorbent article - Google Patents

Abstract

To provide an absorbent article whose body fluid liquid diffusion performance is improved to reduce wetness of the skin while worn and which is excellent in liquid return preventability to the skin.SOLUTION: An absorbent article 1 includes an absorbent core 40 and a skin side core wrap sheet 41U covering a skin facing surface of the absorbent core 40. The skin side core wrap sheet 41U is a laminated sheet which has a hydrophilic fiber layer 43 arranged on an inner surface side and composed mainly by a non-thermoplastic hydrophilic fiber 45 and a synthetic fiber layer 42 arranged on an outer surface side and mainly composed by thermoplastic synthetic fiber 44. The absorber 4 has a recessed part 8 where the skin side core wrap sheet 41U is pressed into an inside of the absorbent core 40. The skin side core wrap sheet 41U is higher in liquid permeability in the recessed part 8 than liquid permeability at parts other than the recessed part 8.SELECTED DRAWING: Figure 5

Description

  The present invention relates to an absorbent article such as a disposable diaper.

  As absorbent articles such as disposable diapers, generally, a liquid-permeable top sheet that forms a skin-facing surface, a liquid-impermeable back sheet that forms a non-skin-facing surface, and absorption disposed between these two sheets It is known to have a body, and the absorbent body comprises an absorbent core comprising an absorbent material such as wood pulp and a water-absorbing polymer, and a core wrap sheet for covering the outer surface of the absorbent core.

  The core wrap sheet acts as a sheet for receiving the absorbent material at the time of manufacture of the absorbent, and plays a role of wrapping and shaping the absorbent core after manufacture. Although it is general to use water-permeable sheets such as thin paper and absorbent paper as the core wrap sheet, from the viewpoint of improving the strength of the absorbent after absorption of body fluid, the present applicant has previously made water permeability made of non-woven fabric. It has been proposed to use an elastic sheet (Patent Document 1).

  In Patent Document 1, a non-stacked portion is provided in the liquid-retaining absorbent core, and in the non-stacked portion, the skin-side core wrap sheet covering the absorbent core and the non-skin-side core wrap sheet are joined. An absorbent article comprising an absorbent body is described. Patent Document 1 describes the use of a hydrophilic non-woven fabric composed of fibers to which a hydrophilization treatment has been applied, as a core wrap sheet.

  Further, in Patent Document 2, the absorbent body provided in the absorbent article has a pressing portion compressed in the thickness direction, and the pressing portion extends in the first inclination direction and the second compression direction extending in the first inclination direction. An absorbent article comprising a second pressing part is described. The 1st pressing part and the 2nd pressing part which the absorber as described in patent document 2 has are formed alternately at intervals.

JP, 2016-83194, A Unexamined-Japanese-Patent No. 2014-100262

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

  However, patent documents 1 and 2 do not describe at all about using nonwoven fabric of a multilayer structure for a core lap sheet. In addition, Patent Literatures 1 and 2 reduce the wetting of the skin and do not describe at all the liquid reversion prevention property to the skin.

  Therefore, the present invention is to provide an absorbent article that can eliminate the drawbacks of the prior art described above.

The present invention relates to an absorbent having a liquid-retaining absorbent core and a skin-side core wrap sheet for covering the skin-facing surface of the absorbent core, and liquid permeability disposed on the skin-facing surface of the absorbent. And a longitudinal direction extending from the ventral side of the wearer to the dorsal side via the crotch and a transverse direction perpendicular thereto, and the crotch disposed in the crotch and extending in front and behind thereof An absorbent article comprising a ventral side and a dorsal side, wherein the skin side core wrap sheet is disposed on the inner surface side in contact with the absorbent core, and is mainly composed of non-thermoplastic hydrophilic fibers. A laminated sheet having the hydrophilic fiber layer as described above and a synthetic fiber layer disposed on the outer surface side in contact with the hydrophilic fiber layer and mainly composed of a thermoplastic synthetic fiber, and the absorbent body is The side core wrap sheet bites into the inside of the absorbent core It has a Recessed portion, the skin-side core wrap sheets, liquid-permeable in the recessed portion is higher than the liquid-permeable at portions other than the recessed portion, an absorbent article.

  ADVANTAGE OF THE INVENTION According to this invention, while the liquid diffusivity of a bodily fluid improves and it reduces the wetting of the skin in wear, the absorbent article which is excellent in the liquid return prevention property to skin is provided.

FIG. 1 is a plan view schematically showing the skin-facing surface, that is, the front sheet side, of a spreadable disposable diaper according to an embodiment of the absorbent article of the present invention. It is a top 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 top view of the absorber provided in the disposable diaper shown in FIG. FIG. 4 is a cross-sectional view schematically showing a cross section taken along line IV-IV of FIG. FIG. 5: is sectional drawing which shows typically the cross section in alignment with the thickness direction of the recessed part in the absorber provided in the disposable diaper shown in FIG. FIG. 6 is a plan view schematically showing another pattern of the recess in the absorber according to the present invention.

  Hereinafter, the absorbent article of the present invention will be described based on an example of a spreadable disposable diaper which is a preferable embodiment thereof with reference to the drawings. FIG. 1 and FIG. 2 show the unfolded disposable diaper 1 of the present embodiment. The diaper 1 is disposed on the skin-facing surface side of the absorbent body 4 having the liquid-holding absorbent core 40 and the skin-side core wrap sheet 41U that covers the skin-facing surface of the absorbent core 40. A liquid permeable top sheet 2 is provided. The diaper 1 has a longitudinal direction X extending from the ventral side of the wearer to the dorsal side via the crotch and a transverse direction Y orthogonal thereto, and the crotch 1M disposed in the crotch and the front and back thereof It comprises the existing ventral side 1F and dorsal side 1R. The ventral side portion 1F, the crotch portion 1M and the back side portion 1R correspond to the respective regions when the diaper 1 is divided into three in the longitudinal direction X. The crotch portion 1M has an excretory part opposing part disposed to face the excretory part such as the wearer's penis or anus when the diaper 1 is worn, and the excretory part opposing part is generally in the longitudinal direction X of the diaper 1 It is located at or near the center. The thickness direction which is a perpendicular direction orthogonal to the surface direction consisting of the longitudinal direction X and the transverse direction Y will be described as the Z direction.

  As shown in FIGS. 1 and 2, the diaper 1 is disposed on the skin-facing surface side of the absorbent body 4 having the absorbent core 40 and the absorbent body 4, and is positioned closer to the wearer's skin than the absorbent body 4 Liquid permeable top sheet 2 that can come into contact with the wearer's skin when worn, and a non-skin facing surface side of the absorbent body 4 that is located farther from the wearer's skin than the absorbent body 4 A permeable or water repellent back sheet 3 is provided. The diaper 1 has an elongated hourglass shape in which the central portion in the longitudinal direction X located in the crotch portion 1M is inwardly narrowed in one view in plan view as shown in FIG. The top sheet 2 and the back 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 diaper 1 in the unfolded and stretched state as shown in FIG. ing.

In the present specification, the "skin-facing surface" is a surface of the absorbent article or a component thereof (for example, the absorbent core 40) that is directed to the skin side of the wearer when wearing the absorbent article, that is, relative It is the side close to the wearer's skin, and the "non-skin facing surface" is the surface of the absorbent article or its component that is directed to the side (dressing side) opposite to the skin side when wearing the absorbent article, ie relative It is the side far from the wearer's skin. In addition, "at the time of wearing" here means the state by which the usual appropriate wearing position was maintained.

  A belt-like elastic member 11 is formed between the top sheet 2 and the back sheet 3 at the waist of each of the ventral side 1F and the back side 1R, that is, at the end in the longitudinal direction X. The entire length is fixed in an extended state in the lateral direction Y, whereby a waist gather is formed on the waist portion when the diaper 1 is worn by the contraction of the elastic member 11. In addition, a plurality of thread-like elastic members 12 are fixed in the lateral direction Y in a stretched state between the top sheet 2 and the back sheet 3 in the waist area corresponding to the waist area of the wearer in the back side 1R. Thereby, the waist gather is formed on the waist portion of the diaper 1 by the contraction of the elastic member 12 when the diaper 1 is worn. Moreover, the side sheet 5 is each distribute | arranged to the left-right both sides in alignment with the longitudinal direction X in the surface sheet 2 side of the diapar 1, ie, the skin opposing surface side. The side sheet 5 has an inner edge along the longitudinal direction X, and an outer edge along the longitudinal direction X which is located outward in the lateral direction Y than the inner edge, and is a flat surface as shown in FIG. In view, the inner edge overlaps the absorber 4, and the outer edge extends outward from the side edge along the longitudinal direction X of the absorber 4 in the lateral direction Y, as shown in FIG. It is joined with 3. A thread-like elastic member 13 is fixed in a stretched state along the longitudinal direction X between the side sheet 5 and the back sheet 3 in the left and right leg portions arranged around the leg of the wearer, whereby When the diaper 1 is worn, a pair of leg gathers are formed in the leg portion by the contraction of the elastic member 13. In addition, a thread-like elastic member 14 is fixed in an extended state along the longitudinal direction X to the inner edge of the side sheet 5, and the inner edge is at least the crotch 1M, specifically, for example, The crotch 1M and the portion on the ventral side 1F and the dorsal side 1R toward the crotch 1M are free ends not joined to other components of the diaper 1 including the top sheet 2, The front and rear end portions in the longitudinal direction X in 1F and the back side 1R are joined to the top sheet 2 (not shown). With such a configuration of the side sheet 5, when the diaper 1 is worn, the contraction force of the elastic member 14 acts in the longitudinal direction X, and the side sheet 5 is a region where at least the inner edge portion is a free end portion. In the above, a pair of right and left leakproof cuffs are formed standing up toward the wearer's skin starting from the junction with the back sheet 3. The top sheet 2, the back sheet 3, the absorber 4, the side sheets 5, and the elastic members 11 to 14 are joined to each other by a known joining means such as a hot melt adhesive.

  As shown in FIG. 1, a pair of fastening tapes 6, 6 is provided on both side edges along the longitudinal direction X of the back side 1 </ b> R of the diaper 1. A fastening portion 61 made of a male member of a mechanical surface fastener is attached to the fastening tape 6. In addition, on the non-skin facing surface of the ventral side portion 1F of the diaper 1, an attachment area 7 made of a female member of a mechanical surface fastener is formed. The attachment region 7 is a non-skin facing surface of the back sheet 3 forming the non-skin facing surface of the belly side 1F, with a female member of a mechanical surface fastener by a known bonding means such as an adhesive or 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, it is possible to use various types of materials conventionally used in absorbent articles such as disposable diapers without particular limitation, and it is premised that the sheet is a liquid-permeable sheet which can permeate body fluid such as urine and feces. A woven or non-woven fabric made of a synthetic fiber or a natural fiber, a porous sheet or the like can be used. As an example of the surface sheet 2, a non-woven fabric made of natural fibers such as cotton or a non-woven fabric made of various synthetic fibers subjected to a hydrophilization treatment can be used. For example, a core-sheath type (including side-by-side type) composite fiber using polypropylene or polyester as the core component and polyethylene as the sheath component is formed into a web by carding, and then nonwoven fabric by the air through method Treatment may be performed). In addition, a perforated sheet made of a polyolefin such as low density polyethylene can be preferably used from the point of liquid permeability (dry feeling).
As the back sheet 3, various materials conventionally used in absorbent articles such as disposable diapers can be used without particular limitation, and those having liquid impermeability (including water repellency) and moisture permeability are preferable Used. Specifically, in order to obtain sufficient water vapor permeability, a film made of a synthetic resin such as polyethylene in which fine powder consisting of a filler such as calcium carbonate is dispersed is stretched, and a porous film provided with fine pores is a back sheet It can be suitably used as 3.
As the side sheet 5, one usable as the back sheet 3 can be used.

  As shown in FIGS. 2 and 3, the absorbent body 4 is configured to include a liquid-retaining absorbent core 40 and a core wrap sheet 41 that covers the absorbent core 40. The absorbent core 40 and the core wrap sheet 41 are preferably joined by a known joining means such as a hot melt adhesive. The absorbent core 40 constituting the absorbent body 4 has an hourglass shape in which the central portion in the longitudinal direction X located in the crotch 1M is inwardly narrowed in the longitudinal direction X in plan view as shown in FIGS. 1 and 3. It has a long vertical 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 in absorbent articles such as disposable diapers can be used without particular limitation. For example, cellulose fibers such as wood pulp, synthetic fibers treated with a hydrophilizing agent And hydrophilic fibers and water-absorbing polymers. Examples of the structure of the absorbent core 40 include a pile of hydrophilic fibers, a structure in which the pile is made to carry a water absorbing polymer, or a structure consisting only of a water absorbing polymer. 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 or less from the viewpoint of suppressing discomfort when the diaper 1 is worn and improving fit. It is further more preferable that it is / m ² or less.

  As shown in FIGS. 2 to 4, in the diaper 1, the core wrap sheet 41 covers the skin-side core wrap sheet 41 </ b> U covering the skin facing surface of the absorbent core 40 and the non-skin facing surface of the absorbent core 40. And the 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 greater than the length in the longitudinal direction X of the absorbent core 40 in the longitudinal direction X, and as shown in FIG. 2 in the lateral direction Y. , Covering the skin facing surface of the absorbent core 40, and further, both sides along the longitudinal direction X of the core wrap sheet 41 are caught on the non-skin facing surface side of the absorbent core 40; The absorbent core 40 is encased so as to overlap at the central portion in the lateral direction Y of the facing surface. Thus, in the single core wrap sheet 41 that wraps the absorbent core 40, the sheet portion covering 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 that covers the non-skin side core wrap sheet 41D.

  The skin-side core wrap sheet 41U and the non-skin-side core wrap sheet 41D are disposed on the inner surface side in contact with the absorbent core 40 as shown in FIG. 2 and FIG. It is a laminated sheet having a hydrophilic fiber layer 43 mainly composed of a synthetic fiber layer 42 mainly composed of a thermoplastic synthetic fiber 44 and disposed on the outer surface side in contact with the hydrophilic fiber layer 43. In FIG. 4, the absorbent core 40, the skin side core wrap sheet 41 U disposed on the skin facing surface side of the absorbent core 40, and the non-skin side core disposed on the non-skin opposing 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 may contain at least 80 mass% or more of thermoplastic synthetic fibers 44, and the content of the thermoplastic synthetic fibers 44 may be 100 mass% with respect to the total mass of the synthetic fiber layers 42. The hydrophilic fiber layer 43 may contain at least 80 mass% or more of the hydrophilic fiber 45, and the content of the hydrophilic fiber 45 may be 100 mass% with respect to the total mass of the hydrophilic fiber layer 43.

  The skin-side core wrap sheet 41U is relatively close to the wearer's skin as shown in FIG. 4 and is relatively close from the wearer's skin with the synthetic fiber layer 42 disposed on the outer surface side of the absorbent core 40. A laminated structure (two-layer structure) with the hydrophilic fiber layer 43 on the inner surface side which is in contact with the absorbent core 40 is included. The synthetic fiber layer 42 of the skin side core wrap sheet 41 U is disposed to face the surface sheet 2, and the hydrophilic fiber layer 43 is disposed to face the absorbent core 40. The synthetic fiber layer 42 and the hydrophilic fiber layer 43 are integrated at least via a recess 8 described later, and depending on the manufacturing method, the constituent fibers of both layers 42 and 43 may be further entangled, an adhesive, etc. It can also be integrated by other integration 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 the synthetic fiber layer 42 disposed on the outer surface side of the absorbent core 40, relative to the wearer's skin. And a laminated structure (two-layer structure) with the hydrophilic fiber layer 43 on the inner surface side in contact with the absorbent core 40. The synthetic fiber layer 42 of the non-skin side core wrap sheet 41 D is disposed to face the back sheet 3, and the hydrophilic fiber layer 43 is disposed to face the absorbent core 40. The synthetic fiber layer 42 and the hydrophilic fiber layer 43 may be further integrated by an integration means such as entanglement of constituent fibers of both layers 42, 43 or a bonding means such as an adhesive depending on the manufacturing method.

  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 assembly 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 a paper. In FIG. 4 and FIG. 5, the thermoplastic synthetic fiber 44 is shown by a relatively thin line, and the non-thermoplastic hydrophilic fiber 45 is shown by a relatively thick line, from the viewpoint of easy understanding. 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 configured to include 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 spun-bonded non-woven fabrics, melt-blown non-woven fabrics, spun-bonded-melt blown-spun bonded non-woven fabrics, etc. And spun lace nonwoven fabrics, resin bonded nonwoven fabrics, needle punched nonwoven fabrics and the like. It is also possible to use a laminate in which two or more of these nonwoven fabrics are combined, or a laminate in which these nonwoven fabrics are combined with a film or the like. Among these non-woven fabrics, spunbond non-woven fabric and spunbond-meltblown-spunbond non-woven fabric are effective in preventing leakage of absorbent materials such as water-absorbent polymers contained in the absorbent core 40 as compared with air-through non-woven fabrics. It is preferable because it is excellent in From the same point of view, the average interfiber distance of the spunbonded nonwoven fabric or spunbonded-meltblown-spunbonded (SMS) nonwoven fabric is preferably 10 μm or more, more preferably 20 μm or more, and preferably 200 μm or less, more preferably 180 μm. It is below. Average fiber distance is measured by the following method. The average inter-fiber distance of the skin-side core wrap sheet 41U is measured at a portion other than the recessed portion 8 (emboss sectioned area ET which is a non-recessed portion).

<Method of measuring average inter-fiber distance of non-woven fabric constituting synthetic fiber layer 42>
The average inter-fiber distance of the fiber assembly such as non-woven fabric and paper is determined by the following equation (1) based on Wrotnowski's assumption. The following equation (1) is generally used to determine the inter-fiber distance of the fiber assembly. Under Wrotnowski's assumption, the fibers are cylindrical and the fibers are regularly arranged without intersection.
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 inter-fiber distance of the sheet of the single layer structure is determined by the following formula (1).
When the sheet to be measured is a multilayer structure such as SMS non-woven fabric, the average inter-fiber distance of the sheet of the multilayer structure is determined according to the following procedure.
First, the average interfiber distance of each layer constituting the multilayer structure is calculated by the following equation (1). At that time, thickness t, basis weight W, fiber density 及 び and fiber diameter D used in the following formula (1) are respectively for the layer to be measured, and for thickness t, the thickness direction of the layer to be measured Of the cross section along the The thickness t, the basis weight W, and the fiber diameter D are each an average value of measurement values at a plurality of measurement points. The basis weight W (g / m ² ) is obtained by cutting a sheet to be measured into a predetermined size, and after weight measurement, dividing the weight measurement value by the area obtained from the predetermined size. The fiber density ρ (g / cm ³ ) is measured according to 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, if it is a book, JIS handbook fiber-2000, (Described on pages 764 to 765 of the Japan Standards Association). As for the fiber diameter D (μm), ten fiber cross sections of the cut fiber are measured using a scanning electron microscope (DSC 6200 manufactured by Seiko Instruments Inc.), and the average value is defined as the fiber diameter.
Next, the average inter-fiber 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 value of each layer thus obtained is summed to obtain the desired multilayer structure The average inter-fiber distance of the constituent fibers of the sheet is determined. For example, in an SMS non-woven fabric having a three-layer structure consisting 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, If the thickness t of the S layer is 0.1 mm, the average inter-fiber distance LS of the S layer is 47.8 μm, the thickness t of the M layer is 0.01 mm, and the average inter-fiber distance LS of the M layer is 3.2 μm The average inter-fiber distance of 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 the non-skin-side core wrap sheet 41D have a synthetic fiber layer 42 composed of a spunbond nonwoven fabric or an SMS nonwoven fabric having an average inter-fiber distance within the above range, and this synthetic fiber layer The thermoplastic synthetic fiber 44 which is the main constituent fiber of 42 and the non-thermoplastic hydrophilic fiber 45 such as wood pulp are intertwined and configured. If the average inter fiber distance of the synthetic fiber layer 42 is too small, the inter fiber space becomes too narrow, which may make it difficult to ensure the 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 not be continuous from the skin-facing surface side of the synthetic fiber layer 42 to the non-skin-facing surface side. . In addition, when the average inter-fiber distance of the synthetic fiber layer 42 is too large, the effect of preventing leakage of the absorbent material from the absorbent core 40 by the skin side core wrap sheet 41U and the non-skin side core wrap sheet 41D is reduced. In particular, when a water absorbing polymer having a small particle size is used as the absorbent material, the particles may leak out.

The reason why a spunbond non-woven fabric or an SMS non-woven fabric is adopted 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 balance strength and interfiber distance suitable for the core wrap sheet 41. is there. As thermoplastic synthetic fiber 44 which is a main constituent fiber of these nonwoven fabrics, synthetic fiber (for example, polypropylene fiber) to which hydrophilization treatment has been applied or not applied can be exemplified. The basis weight of each of the synthetic fiber layers 42 of the skin side core wrap sheet 41U and the 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 The following, more preferably 15 g / m ² or less.

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

The skin-side core wrap sheet 41U and the non-skin-side core wrap sheet 41D each have an absorbent article on the premise that they have no thermoplasticity as the non-thermoplastic hydrophilic fiber 45 constituting the hydrophilic fiber layer 43. Various hydrophilic fibers conventionally used can be used without particular limitation, and typical one is cellulose fiber. Examples of the cellulose fiber include natural cellulose fibers such as wood pulp such as softwood kraft pulp and hardwood kraft pulp and non-wood pulp such as cotton pulp and straw pulp; regenerated cellulose fibers such as rayon and cupra; 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 through the gaps of thermoplastic synthetic fibers 44 constituting synthetic fiber layer 42 because the fiber length is shorter than regenerated cellulose and 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 fiber 45 constituting the hydrophilic fiber layer 43 and the absorbent core 40 Preferably, the hydrophilic fibers contained in the absorbent material are both wood pulp fibers. As described above, cellulose fibers are highly hydrophilic, and among them, wood pulp fibers have a fiber length shorter than non-wood pulp and regenerated cellulose fibers. Of the wood pulp fibers, among the skin-side core wrap sheet 41U and the non-skin-side core wrap sheet 41D, 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 are constituted. 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 get in between the fibers of the hydrophilic fiber layer 43, and the mutual contact of fibers It is easy to do. Thereby, the body fluid taken in from the skin side can be smoothly transmitted to the absorbent core 40.

In the diaper 1, in each of the skin-side core wrap sheet 41U and the non-skin-side core wrap sheet 41D, the surface layer sheet is a synthetic fiber layer 42 in which the body fluid absorbed in the absorbent core 40 is disposed on the outer surface side of the absorbent core 40. From the viewpoint of preventing return to the two side, the thermoplastic synthetic fiber 44 constituting the synthetic fiber layer 42 has a degree of hydrophilicity that is greater than the degree of hydrophilicity of the non-thermoplastic hydrophilic fiber 45 constituting the hydrophilic fiber layer 43 Is also preferably low. Further, from the viewpoint of diffusing the body fluid with the hydrophilic fiber layer 43 disposed opposite to the absorbent core 40 to improve the utilization efficiency of the absorbent core 40, the non-thermoplastic hydrophilic fiber 45 constituting the hydrophilic fiber layer 43 It is preferable that the degree of hydrophilicity is higher than the degree of hydrophilicity of the thermoplastic synthetic fiber 44 that constitutes the synthetic fiber layer 42.

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

<Method of measuring contact angle>
The fiber is 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 to the fiber 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 an inkjet type water droplet discharge unit (manufactured by Cluster Technology, pulse injector CTC-25 having a discharge diameter of 25 μm) is set to 20 picoliter, and the water droplets are dropped right above the fibers. The state of dropping is recorded on a high-speed recording device connected to a camera installed horizontally. From the viewpoint of later image analysis, the recording device is preferably a personal computer in which a high-speed capture device is incorporated. In this measurement, an image is recorded every 17 msec. In the recorded video, the first image of a drop of water on the fiber, attached software FAMAS (version of software is 2.6.2, analysis method is the drop method, analysis method is the θ / 2 method, image processing algorithm Image analysis is performed with no reflection, image processing image mode is frame, threshold level is 200, curvature correction is not performed, and the angle between the surface of the water droplet that touches the air and the fiber is calculated. Be a corner. The fiber removed from the object to be measured is cut into a fiber length of 1 mm, and the fiber is placed on the sample table of the contact angle meter and kept horizontal. Two different contact angles are measured per fiber. A contact angle of N = 5 is measured to one decimal place, and a value obtained by averaging a total of ten measured values (rounded to the second decimal place) 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.

  In the case where the component (for example, the core wrap sheet 41) is taken out of the absorbent article and evaluated and measured, when the component is fixed to another component by an adhesive, fusion or the like, The fixed portion is removed by coating with a solvent, blowing with a hot air with a drier, spraying with a cold spray (for example, a commercial product manufactured by Nichiban Co., Ltd.), and then removed.

In the skin-side core wrap sheet 41U, liquid permeability in the recess 8 to be described later is higher than liquid permeability in a portion other than the recess 8 (emboss area ET which is a non-recess). Whether 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 by the water droplet loss rate measured by the following method of measuring the water droplet loss rate. Assuming that the ratio between the drop loss rate in the recessed portion 8 and the drop loss rate in the portion other than the recessed portion 8 measured by the method for measuring the drop loss rate is as follows: As the latter, it is preferable that
Two times or more, more preferably three times or more. The water droplet loss rate of the recess 8 is preferably 60% or more, more preferably 80% or more, and the upper limit is 100%.
The drop loss rate of the portion other than the recessed portion 8 is preferably 50% or less, more preferably 30% or less, and the lower limit is 0%.
The permeability is considered to be high if the difference between the drop loss rate is 10% or more in the portion other than the recessed portion 8 and the recessed portion 8.

<Method of Measuring Water Droplet Loss Rate in Portions Other Than Concave Portion 8 and Concave Portion 8>
Sheet to be evaluated (the indented portion 8 or the skin-side core wrap sheet 4 including a portion other than the indented portion 8)
1U) is fixed in the air so that it is horizontal with the synthetic fiber layer 42 facing up. Then, using a microsyringe, drop droplets of saline solution (saline solution with a concentration of 0.9% by mass) at 20 locations on the recess 8 or 20 locations other than the recess 8 using a microsyringe Do. If the degree of hydrophilicity of the dropped portion in the sheet to be evaluated is high, the water droplet is absorbed and dissipated by the sheet immediately after dropped and disappears. If the degree of hydrophilicity of the dropped portion is low, it is not absorbed and it is not absorbed It will remain. The determination of the disappearance of the water droplets is made by visually observing the upper surface of the sheet 10 seconds after dropping the water droplets. Further, the water droplet disappearance rate (%) is obtained by calculating the ratio of the portion where the water droplet has disappeared within 10 seconds, out of the 20 measurements.

  In the diaper 1, the absorbent body 4 has a recessed portion 8 in which the skin-side core wrap sheet 41 </ b> U bites into the inside of the absorbent core 40. The recessed portion 8 is formed by embossing in order to heat and fuse and integrate the synthetic fiber layer 42 on the outer surface side and the hydrophilic fiber layer 43 on the inner surface side constituting the skin side core wrap sheet 41U. An embossed portion formed by embossing such as that formed by embossing or pressing the synthetic fiber layer 42 and the hydrophilic fiber layer 43 by pressing without pressure and pressure bonding and integration. Meaning that In the diaper 1, the non-thermoplastic hydrophilic fiber 45 passes through the synthetic fiber layer 42 on the skin-facing surface side and is absorbed by plasticizing the synthetic fiber layer 42 on the skin-facing surface side with heat as the recessed portion 8 From the viewpoint of being easily exposed to the skin-facing surface side of the body 4, it is formed by applying heat to carry out heat fusion for compounding and integration. In the diaper 1, embossing is performed from the skin facing surface side to the non-skin facing surface side of the absorbent body 4, 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 to form a recess 8. In the recessed portion 8, the synthetic fiber layer 42 of the skin-side core wrap sheet 41U is melted to be integrated with and bonded to the hydrophilic fiber layer 43.

  When the hydrophilic fiber layer 43 contains a hydrophilic thermoplastic synthetic fiber (not shown), as the hydrophilic thermoplastic synthetic fiber (not shown), the thermoplastic synthetic fiber 44 serving as the main component of the above-mentioned synthetic fiber layer 42 What added the hydrophilizing agent normally used to constituent fibers, such as a nonwoven fabric, to the fiber which consists of the same raw material as the above can be used. 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 fibrous layer 43, but the synthetic fibrous layer 42 is constituted. It is preferable that the degree of hydrophilicity of the thermoplastic synthetic fiber 44 be higher.

  In the diaper 1, a plurality of recessed portions 8 are disposed on the skin facing surface of the absorber 4. The recessed portions 8 may be, for example, intermittently arranged in the form of dots, but preferably, they are arranged in a continuous line such as a straight line, a broken line, or a curved line. In the diaper 1, as shown in FIG. 1 and FIG. 3, the absorber 4 is viewed in a plan view, and the concave portion 8 has a plurality of continuous lines so that it has an angle with respect to each longitudinal direction X and lateral direction Y. It is formed. The recessed portions 8 formed in a plurality of continuous lines form crossing portions 8 k which cross each other. Preferably, a plurality of non-embossed portions are formed by forming a crossing portion 8k at a crossing point where the recess portions 8 formed in a plurality of continuous lines intersect each other and the perimeter is surrounded by the recess portions 8 of the continuous lines crossing each other Forming an embossed area ET. That is, in the diaper 1, the liquid permeability in the embossed section area ET is lower than the liquid permeability in the recessed portion 8, and the liquid permeability is high so as to surround the entire periphery of the embossed section area ET. A recess 8 is arranged. By arranging the recessed portion 8 in this manner, even if the body fluid is discharged onto the low-permeable embossed partition area ET and flows over the embossed partition area ET, the liquid permeability around the embossed partition area ET is high. Body fluid can be absorbed by the recess 8 and leakage can be prevented. From the viewpoint of preventing such a leak, it is preferable to arrange the recess 8 so as to surround the entire circumference of the embossed partition area ET.

As described above, the recessed portion 8 easily permeates the body fluid, and at the same time the permeability to the absorbent core 40 of the body fluid discharged from the wearer is higher than that of the embossed zone ET, at the same time it is absorbent. The body fluid absorbed by the core 40 is easily transmitted in the direction of returning to the skin of the wearer. The ratio ((S1 / S0) × 100) of the area (S1) of the recessed portion 8 to the surface area (S0) of the absorber 4 is 10% or more from the viewpoint of facilitating the permeation of the body fluid to the absorbent core 40. Is more preferably 15% or more, and 40% or less, preferably 35% or less, from the viewpoint of preventing the body fluid absorbed by the absorbent core 40 from returning to the wearer side. Is more preferably 10% or more and 40% or less, and more preferably 20% or more and 35% or less from both viewpoints.
Here, the surface area (S0) of the absorber 4 means the area of the entire absorber 4 when the absorbent core 40 covered with the core wrap sheet 41 is viewed in plan, and the area of the recessed portion 8 (S1) ) Means the total surface area of the bottoms of all the recesses 8 when the absorbent core 40 covered with the core wrap sheet 41 is viewed in plan. The surface area (S0) of the absorber 4 includes the area (S1) of the recessed portion 8.

  In the diaper 1, the recesses 8 of the continuous line having an angle with respect to the longitudinal direction X and the lateral direction Y are preferably parallel to one another with a plurality of first recesses 81 arranged parallel to one another and at a predetermined distance. And a plurality of second recesses 82 formed at predetermined intervals, and as shown in FIG. 3, the first recesses 81 and the second recesses 82 form an angle α with each other. Crosses. More preferably, in the diaper 1, the groove width W1 (see FIG. 3) of the first recess 81 and the groove width of the second recess 82 are the same, and the distance W2 between adjacent first recesses 81, 81 The distance between the second concave portions 82 and 82 adjacent to each other (see FIG. 3) is also the same.

  The groove width W1 of the first recessed portion 81 (the 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 to the absorbent core, The diameter 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, the diameter is preferably 3 mm or less, more 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.

  In addition, narrowing the interval W2 between the first recesses 81, 81 (the interval between the second recesses 82, 82) (see FIG. 3) causes the body fluid to be discharged onto the embossed partition area ET having low liquid permeability. It is preferable from the viewpoint of shortening the flow distance of the body fluid to prevent leakage as it has flowed over the embossed partition area ET, while narrowing this interval W2 simultaneously forms a depression formed as a continuous line. The number of portions 8 is increased, which is unsuitable from the viewpoint of making it difficult for the body fluid absorbed in the absorbent core 40 to return to the skin of the wearer. From the viewpoint of the balance between the two, the distance W2 is preferably 5 mm or more, more preferably 15 mm or more, and preferably 40 mm or less, further preferably 20 mm or less, and specifically In particular, it is preferably 5 mm or more and 40 mm or less, and more preferably 15 mm or more and 20 mm or less.

  Moreover, in the diaper 1, the absorber 4 is short in the horizontal direction Y and long in the longitudinal direction X, and in the crotch 1M near the excretory part of the wearer, the shape is narrow in the lateral direction Y in particular. The length (width) in the lateral direction Y is the smallest. For this reason, it is necessary to suppress the flow of the liquid in the lateral direction Y more than the longitudinal direction X from the viewpoint of preventing the leakage of the body fluid. From such a point of view, the angle (angle α) (see FIG. 3) between the first recess 81 and the second recess 82 is preferably 90 ° or less, and more preferably 60 ° or less. . On the other hand, making this angle α too small means simultaneously increasing the number of recesses 8 formed as a continuous line, from the viewpoint of making it difficult for the body fluid in the absorbent core 40 to return to the skin of the wearer It becomes unsuitable. From such a viewpoint, the angle α is preferably 15 ° or more, and more preferably 30 ° or more.

The concave portion 8 having the first concave portion 81 and the second concave portion 82 in the absorbent body 4 of the diaper 1 is, for example, a first concave portion 81 on the circumferential surface of a metallic cylindrical roller such as aluminum alloy or steel. And a heat seal device including a heat seal roller having a convex portion corresponding to the second concave portion 82, or corresponding to the first concave portion 81 and the second concave portion 82 on the circumferential surface of a metallic cylindrical roller It can form using an apparatus provided with the pattern roller and the ultrasonic horn which have a convex part.

  In the recessed portion 8 of the absorbent body 4 of the diaper 1, as shown in FIG. 5, the non-thermoplastic hydrophilic fiber 45 constituting the hydrophilic fiber layer 43 in the skin side core wrap sheet 41U is the synthetic fiber layer 42 on the outer surface side. And exposed to the skin facing surface side of the absorber 4. Preferably, the recessed portion 8 is a portion which has been consolidated in the thickness direction such that the skin-side core wrap sheet 41U bites into the interior of the absorbent core 40. Etc., by means of embossing (squeezing) with a melt promoting means to promote melting of the thermoplastic synthetic fibers 44. In the case of pressing the skin side core wrap sheet 41U with such melting promoting means, the outer surface of the skin side core wrap sheet 41U from the viewpoint of melting promotion of the thermoplastic synthetic fibers 44 constituting the skin side core wrap sheet 41U. It is preferable to press the synthetic fiber layer 42 on the side. The recessed portion 8 has a narrower interfiber space or a substantially interfiber space as compared to a portion other than the recessed portion 8 (non-recessed embossed section area ET) in the skin-side core wrap sheet 41U. The non-recessed portion is a low density portion where the inter-fiber space is wider 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 Therefore, it is exposed to the skin opposing surface side of the absorber 4. 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 fiber 45 exposed on the skin facing surface side of the absorbent body 4 and the hydrophilic fiber 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 concave portion 8, 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 to the skin-facing surface side of the absorbent body 4 depends on the shape of the concave portion 8. It can carry out by microscope observation of the cross section in alignment with a thickness direction (Z direction), and can be carried out specifically by the following method.

<Method of Confirming that Non-Thermophilic Hydrophilic Fiber 45 Passes Through the Synthetic Fiber Layer 42 in the Concave Portion 8 and is Exposed to the Skin-facing Surface Side of the Absorbent Body 4>
A sheet (skin-side core wrap sheet 41U) to be evaluated is immersed in a 0.5% by mass blue aqueous solution (Edible Blue No. 1 of Aijin Food Dye manufactured by Daiwa Kasei Kogyo Co., Ltd.), and after standing for 3 minutes, the sheet is removed from the aqueous solution Place the sheet facing the face of the taken-out side down on a sheet of paper (Kim towel, Nippon Paper Industries Co., Ltd.) and remove water from the top of the sheet for one minute using a load of 3 kPa. Do. Among the constituent fibers of the evaluation target sheet, hydrophilic fibers are dyed by this operation. 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 feather razor made by Feather, and the cut surface is cut with a microscope (VHX-1000 made by KEYENCE) ), 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 recessed portion 8 Check to see if you In the recessed part 8, since the hydrophilic fiber 45 is dyed, it is easy to determine whether it is exposed on the skin facing surface side of the recessed part 8.

As described above, the recess 8 is typically formed by embossing with heat, ultrasonic waves, etc. The synthetic fiber layer of the skin-side core wrap sheet 41U of the recess 8 formed by such embossing At 42, since the thermoplastic synthetic fiber 44 which is the main component thereof is softened and melted by heat or ultrasonic wave at the time of embossing, the form of the original fiber assembly is lost and it is formed into a film. Thus, a part of the non-thermoplastic hydrophilic fiber 45 which makes the main body of the hydrophilic fiber layer 43 intrudes into the film-formed (fiber form is lost) synthetic fiber layer 42 of the recessed portion 8, and an absorbent body is obtained. It is exposed to the skin facing side of 4. That is, in the recessed portion 8, one or more exposed portions of the hydrophilic fibers 45 are present in the film-formed synthetic fiber layer 42 in plan view of the skin facing surface side of the absorber 4. The hydrophilic fiber 45 forming the exposed portion passes through the synthetic fiber layer 42 and is continuous from the skin facing surface side of the skin side core wrap sheet 41U to the non-skin facing surface side.

In the diaper 1, in the recessed portion 8 of the absorber 4, a space K is formed between the top sheet 2 and the absorber 4. Preferably, in the diaper 1, the surface sheet 2 disposed adjacent to the skin facing surface side of the absorber 4 does not enter the recess 8 of the absorber 4, as shown in FIG. 4, the recess At 8, the space K is formed by the non-skin facing surface of the top sheet 2 and the skin facing surface of the recessed portion 8 of the absorber 4. The space K is formed corresponding to the shape pattern of the recess 8 having the first recess 81 and the second recess 82 in plan view of the diaper 1 as shown in FIG. 3.
Moreover, such a structure apply | coats an adhesive agent to the part except the recessed part 8 at least on the skin opposing surface side of the absorbent 4 after forming the recessed part 8 in the absorber 4, and absorbs the surface sheet 2 after that It can form by the process affixed on the skin opposing surface side of the body 4. The adhesive is preferably a hot melt adhesive. The coating method of the adhesive is not particularly limited, but a method of coating by contacting a coater gun of a contact type coater coater with a portion excluding the concave portion 8 on the skin opposing surface side of the absorber 4 is preferable. Although a surface coating pattern, a stripe coating pattern, etc. are applied to the coating pattern in a coater coating machine, the stripe coating pattern is preferable because the inhibition of the permeation of the body fluid by the adhesive hardly occurs.

As described above, in the diaper 1, as shown in FIGS. 2 to 4, the absorbent core 40 constituting the absorbent body 4 is covered with the skin-side core wrap sheet 41 U, and the skin-side core wrap sheet 41 U is A hydrophilic fiber layer 43 disposed on the inner surface side in contact with the absorbent core 40 and composed mainly of the non-thermoplastic hydrophilic fibers 45 and an outer surface side in contact with the hydrophilic fiber layer 43 and thermoplasticity It is formed of a laminated sheet having a synthetic fiber layer 42 mainly composed of synthetic fibers 44. And the absorber 4 has the recessed part 8 which the skin side core wrap sheet 41U cut into the inside of the absorptive core 40, and the liquid permeability in the recessed part 8 of the skin side core wrap sheet 41U is recessed. It is higher than the liquid permeability in the portion other than the portion 8 (the embossed section area ET which is a non-embossed section surrounded by the recess 8). Therefore, the body fluid is easily absorbed from the recessed portion 8 in the skin side core wrap sheet 41U to the inside of the absorbent core 40 while being worn. 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 diffusibility is improved, the utilization efficiency of the absorber 4 is improved, and the wear is achieved. It is possible to reduce the wetting of the inside skin.
In addition, since the skin-side core wrap sheet 41U located in the recessed portion 8 bites into the inside of the absorbent core 40, the return of body fluid is made to the absorbent core 40 through the recessed portion 8 because the distance from the surface sheet is increased. It is difficult for the absorbed body fluid to return to the skin, and it is excellent in the ability to prevent liquid from returning to the skin.

Further, in the diaper 1, the recessed portion 8 is higher in liquid permeability than the liquid permeability of the portion other than the recessed portion 8, and at the same time it is easy to absorb body fluid into the absorbent core 40, the inside of the absorbent core 40. The body fluid in is easy to return to the wearer. 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 and therefore the skin of the wearer Wetness can be reduced. Furthermore, since the surface sheet 2 is arranged so that the space K is formed by the non-skin facing surface of the surface sheet 2 and the skin facing surface of the recess 8 of the absorbent body 4 in the recessed portion 8, The wearer's skin does not come close to the recess, and also from this point of view, it is possible to reduce the wetting of the wearer's skin.
Furthermore, if the degree of hydrophilicity of the thermoplastic synthetic fiber 44 of the synthetic fiber layer 42 is lower than the degree of hydrophilicity of the non-thermoplastic hydrophilic fiber 45, the body fluid once absorbed by the absorbent body 4 corresponds to the hydrophilic fiber layer 43. By the synthetic fiber layer 42 disposed on the outer surface side to be in contact, it is further difficult to return to the skin side of the wearer, and the liquid return prevention property is excellent, and the feeling of use of the diaper 1 is improved.

  Moreover, as shown in FIG. 5, the diaper 1 has the non-thermoplastic hydrophilic fibers 45 of the skin-side core wrap sheet 41U passing through the synthetic fiber layer 42 on the outer surface side as shown in FIG. The hydrophilic fiber layer 43 exposed on the opposite surface side and in contact with the inner surface of the skin-side core wrap sheet 41U 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 (flowing trigger) of the body fluid, and the absorber 4 located in the recessed portion 8 The body fluid on the surface facing the skin is likely to be diffused into the hydrophilic fiber layer 43 through the recessed portion 8 (exposed portion of the hydrophilic fiber 45) and rapidly 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 crossing portions 8 k crossing each other. Therefore, the absorbent core 40 can be easily taken in through the intersection 8 k.

  Moreover, 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 retention property of the absorber 4 during wear is excellent, the absorber 4 is not easily broken during wear, and the feeling of use is improved.

From the viewpoint of further achieving the effects described above, the diaper 1 preferably includes one or more of the following configurations.

When ten are selected arbitrarily from the plurality of recessed portions 8 present in the absorbent body 4, in the ten recessed portions 8, the skin facing surface side of the absorbent body 4, in other words, the skin facing surface side of the recessed portions 8 A ratio in which the non-thermoplastic hydrophilic fibers 45 (component fibers of the hydrophilic fiber layer 43 of the skin-side core wrap sheet 41U) are exposed (hereinafter, also referred to as "hydrophilic portion exposed recessed portions"), That is, 50% or more is preferable and 80% or more is more preferable as the value calculated by “(the number of hydrophilic portion exposed concave portions / 10) × 100”.
In addition, it is confirmed by the following method whether a certain recessed part is the said hydrophilic part exposure recessed part. That is, it is confirmed whether the fiber (hydrophilic fiber 45) of the hydrophilic fiber layer 43 is exposed by the said method about the concave part of evaluation object by the said method about the concave part of evaluation object, When the exposure can be confirmed even at one place, the recessed portion is assumed to be the hydrophilic portion exposed recessed portion.
Further, 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 arbitrary 10 places are selected so as not to overlap.

  In the skin-side core wrap sheet 41 U, the synthetic fiber layer 42 has a lower degree of hydrophilicity than the hydrophilic fiber layer 43 in the portion other than the recessed portion 8 (emboss sectioned area ET), in other words, the hydrophilic fiber layer 43 Preferably have a higher degree of hydrophilicity than the synthetic fiber layer 42. The degree of hydrophilicity of the sheet (layer) referred to herein is evaluated by the water droplet disappearance rate measured by the following method. The smaller the value of the drop loss rate, the lower the degree of hydrophilicity, and the larger the drop loss rate, the higher the degree of hydrophilicity. Therefore, it is preferable that the magnitude relationship of “water droplet disappearance rate of synthetic fiber layer <the water droplet disappearance rate of the hydrophilic fiber layer 43” be established.

<Method of Measuring Water Drop Loss Rate of Core Wrap Sheet, Synthetic Fiber Layer Thereof, or Hydrophilic Fiber Layer>
A sheet to be evaluated (for example, skin-side core wrap sheet 41U or its synthetic fiber layer 42 or hydrophilic fiber layer 43) is fixed in the air so that the surface is horizontal, and any 20 points on the upper surface of the sheet Water droplets (2 μl of one drop) of physiological saline (saline with a concentration of 0.9% by mass) are dropped using a microsyringe. If the degree of hydrophilicity of the sheet to be evaluated is high, the water droplets are immediately absorbed by the sheet and dropped after dropping, and if the degree of hydrophilicity of the sheet is low, it is not absorbed and remains on the top surface of the sheet. The determination of the disappearance of the water droplets is made by visually observing the upper surface of the sheet 10 seconds after dropping the water droplets. In addition, the drop rate (%) of the 20 points of the measurement,
It calculates | requires by calculating the ratio of the location where the water droplet disappeared within 10 seconds.

Assuming that the ratio between the drop loss rate of the portion other than the recessed portion 8 of the synthetic fiber layer 42 and the drop loss rate of the portion other than the recessed portion 8 of the hydrophilic fiber layer 43 is smaller than the latter. As the latter, it is preferably 0.5 or less, more preferably 0.3 or less.
The water droplet loss rate of the portion other than the concave portion 8 of the synthetic fiber layer 42 is preferably 0% or more, more preferably 20% or more, and preferably 80% or less, more preferably 50% or less.
The water droplet disappearance rate of the portion other than the recessed portion 8 of the hydrophilic fiber layer 43 is preferably 50% or more, more preferably 80% or more.
The adjustment of the water droplet number loss rate, that is, the adjustment of the degree of hydrophilicity, the types of the constituent fibers of the synthetic fiber layer 42 (thermoplastic synthetic fibers 44) and the constituent fibers of the hydrophilic fiber layer 43 (hydrophilic fibers 45) It can be implemented mainly by using synthetic fiber layer 42), a hydrophilizing agent (mainly for hydrophilic fiber layer 43), and the like.

  In the diaper 1, the absorbent core 40 constituting the absorbent body 4 is configured to include the water-absorbent polymer and the cellulose-based fiber, and the content weight ratio of the water-absorbent polymer to the cellulose-based fiber is the former: the latter Preferably, they are 40: 60-70: 30, More preferably, they are 50: 50-60: 40.

In a further preferred form of the diaper 1, the basis weight of the water-absorbing polymer in the absorbent core 40 in the region corresponding to the recessed portion 8 is the water-absorbing polymer in the absorbent core 40 in the region corresponding to the portion other than the recessed portion 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 thickness of the absorbent core 40 increases in the Z direction (thickness direction). The increase in thickness depends on the basis weight of the water-absorbing polymer. When the basis weight of the water-absorbing polymer in the absorbent core 40 in the region corresponding to the recessed portion 8 is smaller than the basis weight of the water-absorbing polymer in the region corresponding to the portion other than the recessed portion 8 In this case, the increase in thickness of the recess 8 is suppressed smaller than the increase of the thickness of the portion other than the recess 8. Even after the body fluid is absorbed, the recess 8 is compared to the portion other than the recess 8 It is possible to maintain the state of biting into the absorbent core 40. In order to form a space K between the non-skin facing surface of the top sheet 2 and the skin facing surface of the recessed portion 8 of the absorbent body 4, the recess 8 having high liquid permeability bites into the absorbent core 40. The effect of the configuration in which the surface sheet 2 is disposed is as described above, but from the viewpoint that this effect can be sustained after absorption of body fluid, the basis weight of the water-absorbing polymer in the absorbent core 40 in the portion corresponding to the recessed portion 8 It is preferable to make the structure smaller than the basis weight of the water-absorbing polymer in the absorbent core 40 in the portion corresponding to the portion other than the recessed portion 8.
Here, the recessed portion 8 in the absorbent core 40 and the portion having a small basis weight of the water absorbing polymer do not have to completely match, and the total area of the recessed portion 8 when the absorbent core 40 is viewed in plan On the other hand, the area in which the portion where the content of the polymer is low overlaps with the recessed portion 8 may be 50% or more, more preferably 75% or more. Most preferable is a form in which the shape pattern of the recessed portion 8 when the absorbent core 40 is viewed in a plan view is bordered, and a portion containing a small amount of polymer is arranged in the shape pattern including the recessed portion 8. 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 disposed at the position coincident with the recessed portion 8 and the width of the continuous line is larger than that of the recessed portion. It is a form which distributes a small part. By adopting such a form, the above-described effects can be further enhanced.
In this embodiment, 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 recessed portion 8 or the width of the portion having a small basis weight of the water absorbing polymer The width is preferably larger than the width of the recess 8, more preferably 3 mm or more, and still more preferably 5 mm or more. On the other hand, if the width of the portion having a low basis weight of the water-absorbent polymer is increased, the absorption capacity of the entire absorbent core 40 will be reduced, which may cause leakage of the body fluid. From this viewpoint, the area of the portion having a small basis weight of the water-absorbing polymer when the absorbent core 40 is viewed in plan view is preferably 50% or less, more preferably 40% or less of the entire area of the absorbent core 40 preferable.
Although the manufacturing method of the absorptive core 40 of the form mentioned above is not specifically limited, For example, after mixing a hydrophilic fiber and a water absorbing polymer uniformly and stacking it, it is a place other than concave part 8 at the following process. And a method of spraying a water absorbing polymer in a pattern.

Further, in the absorbent core 40 of the diaper 1, the basis weight of the portion having a small amount of the water absorbing polymer is preferably 70% or less, more preferably from the same viewpoint when the basis weight of the other portion is 100%. Is less than 50%.
The amount of the water-absorbing polymer contained in the absorbent core 40 can be determined from the ratio of the amount of sodium ions contained in the water-absorbing polymer by quantifying the sodium ion by means of ICP emission analysis or the like. As a simple means of determining the ratio of the polymer basis weight of the low polymer content portion and the polymer basis weight in other regions, cut the same area of the absorbent core 40 of each part and compare their centrifugal retention It is also possible to substitute sufficiently. The centrifuge retention amount can be measured by the following measurement method.

<Method of measuring centrifuge retention>
The measurement of the amount of centrifugal retention (the amount of water absorption) is performed according to JIS K 7223 (1996). A nylon woven fabric (Sanju Mfg. Co., Ltd., product name: nylon mesh, standard: 250 mesh) is cut into a rectangle 10 cm wide and 40 cm long, folded in half at the longitudinal center, and heat sealed at both ends 10 cm wide (Inside dimension 9 cm), make a 20 cm long nylon bag. Next, 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) adjusted to 25 ° C. After one hour from the start of immersion, the nylon bag is taken out of the physiological saline, suspended vertically for one hour and drained, and then dewatered using a centrifugal dehydrator (manufactured by Koksan Co., Ltd., model H-130C special type). The dehydration conditions are 143 G (800 rpm) for 10 minutes. After dehydration, the mass of the sample is measured, and the target amount of centrifugal retention (water absorption) is calculated according to the following equation.
Centrifugal holding amount (g) = (a '-b-c)
Where a 'is the total mass (g) of the sample and nylon bag after centrifugal dewatering, b is the mass (g) of the nylon bag before water absorption (during), c is the mass of the sample before water absorption (during) Represents (g). The measurement is performed five times (n = 5), the values at one upper and lower point are deleted, and the average value of the remaining three points is taken as the measured value. The measurement is performed at 23 ± 2 ° C. and 50 ± 5% humidity, and the sample is stored for 24 hours or more in the same environment before the measurement.

  Further, from the viewpoint of promoting the diffusion of body fluid such as urine in the longitudinal direction X, in the skin-side core wrap sheet 41U, the non-thermoplastic hydrophilic fibers 45 forming the main body of the hydrophilic fiber layer 43 extend in the longitudinal direction X. It is preferable to be 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 absorbent body 4, the density of the absorbent core 40 is preferably larger 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 the thickness obtained based on the measurement method described later.
In the recessed portion 8 of the absorbent body 4, the basis weight of the absorbent core 40 is preferably 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 recessed portion 8 of the absorbent core 40 and the basis weight of the portion other than the recessed portion 8 of the absorbent core 40 are preferably 200 g / m ² or more, more preferably 400 g / m ² or more, and preferably 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 measurement method.
In the recessed portion 8 of the absorbent body 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, more preferably 2.0 mm or less. The thickness of the portion other than the recessed portion 8 of the absorbent core 40 is preferably 2.0 mm or more, more preferably 3.0 mm or more, and preferably 5.0 mm or less, more preferably 4.0 mm or less. The thickness of the absorbent core 40 is measured by the following measurement method.

<Method of measuring basis weight of absorbent core 40>
The absorber 4 is cut along the boundary between the recess 8 and the portion other than the recess 8 (emboss section ET) using a feather razor made by Feather Inc., and a small piece of the recess 8 in the absorber 4; Pieces of a portion other than the recessed portion 8 in the absorber 4 are obtained. These pieces are cut out so as to have a predetermined area. The small pieces of the absorbent core 40 located in the recessed portion 8 and the portions other than the recessed portion 8 so as to be only the portions of the absorbent core 40 except the portion such as the core wrap sheet 41 from the cut out small pieces The piece of absorbent core 40 located in 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 can be used as an electronic balance (electronic balance GR-300 manufactured by A & D, Accuracy: Measure using 4 digits after the decimal point. The weight determined is divided by the predetermined area to calculate the basis weight of the small piece. The average basis weight of the five 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.

Method of Measuring Thickness of Absorbent Core 40
The thickness of the concave portion 8 of the absorbent core 40 and the thickness of the portion of the absorbent core 40 other than the concave portion 8 were measured to determine the basis weight of each portion. The measurement is performed by using a small piece of the small piece and a small piece of a portion other than the recessed portion 8 in the absorber 4. An acrylic plate of 20 mm × 20 mm in size and 3 mm in thickness is placed with its center at the center of the small piece, and the cut surface is observed at a magnification of 20 to 100 times using a microscope (VHX-1000 made by KEYENCE) The thickness from the boundary between the portion of the absorbent core 40 and the portion of the core wrap sheet 41 etc. other than the absorbent core 40 is measured. The pressure for thickness measurement is 0.5 g / cm ² (= 0.05 kPa) (= 0.05 kPa).

  The absorber 4 preferably has a depth of 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. And, from the viewpoint of high liquid permeability, 80% or less of the thickness of the absorbent core is preferable. The depth at the recess 8 is measured by the following measurement method.

<Method of measuring depth at recessed portion 8>
The depth of the recessed portion 8 is determined by cutting the absorber 4 across the entire width of the recessed portion 8 using a feather blade razor manufactured by Feather Inc. and observing the cut surface of the cut-out piece. An acrylic plate of 20 mm × 20 mm in size and 3 mm in thickness is placed with its center at the center of the small piece, and the cut surface is observed at a magnification of 20 to 100 times using a microscope (VHX-1000 made by KEYENCE) The distance from the boundary between the portion of the absorbent core 40 and the portion of the core wrap sheet 41 etc. other than the absorbent core 40 is measured as the depth from the bottom surface of the recessed portion 8. In addition, the pressure at the time of depth measurement shall be 0.5 g / cm ² .

In the skin side core wrap sheet 41U, it is preferable that the fiber diameter of each of the thermoplastic synthetic fiber 44 and the non-thermoplastic hydrophilic fiber 45 be smaller. The relatively small fiber diameter of the thermoplastic synthetic fiber 44 that is the main component of the synthetic fiber layer 42 further facilitates melting and deformation of the fiber 44 due to consolidation, and also on the skin-facing surface side of the absorbent body 4 The exposure of the hydrophilic fiber 45 is more likely to occur, and the relatively small diameter of the hydrophilic fiber 45 which is the main component of the hydrophilic fiber layer 43 makes the exposure of the fiber 45 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, more preferably 2.2 dtex or less. Also, the thickness of the non-thermoplastic hydrophilic fiber 45, that is, the diameter when the cross-sectional shape in the direction orthogonal to the longitudinal direction of the hydrophilic fiber 45 is circular, and the major axis of the oval / flat shape. The length is preferably 50 μm or less, more preferably 30 μm or less.

  In addition, regarding the non-thermoplastic hydrophilic fiber 45, the cross section of the hydrophilic fiber 45 is a true circle or a circular shape close to it, from the viewpoint of more reliably achieving the exposure of the absorber 4 on the skin facing surface side It is preferable from

Further, the basis weight of the synthetic fiber layer 42 is preferably relatively small. When the basis weight of the synthetic fiber layer 42 is 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 film is formed on the skin facing surface side of the recessed portion 8 There is a possibility that the non-thermoplastic hydrophilic fiber 45 may not be easily exposed to the skin-facing surface side of the absorber 4 as it is completely blocked by the fiber layer 42. From the above points, 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
The following, more preferably 15 g / m ² or less.

The skin-side core wrap sheet 41 U is a raw material sheet of a synthetic fiber layer 42 (typically, a non-woven fabric mainly composed of a thermoplastic synthetic fiber 44) and the raw material sheet is a separate hydrophilic fiber layer 43. It may be a laminate obtained by superposing an original sheet (typically, a paper mainly composed of non-thermoplastic hydrophilic fibers 45). The above-described absorber 4 covers the absorbent core 40 by using the skin-side core wrap sheet 41U formed of such a laminate, and heat, ultrasonic waves, and the like are applied to the formation planned portion of the recessed portion 8. It can be manufactured by embossing (squeezing) with a melt promoting means for promoting the melting of the plastic synthetic fiber 44. By this embossing, the thermoplastic synthetic fiber 44 in the raw sheet of the synthetic fiber layer 42 on the outer surface side is melted and deformed to be a film, and the hydrophilic fiber in the raw sheet of the hydrophilic fiber layer 43 on the inner surface side 45 is likely to be exposed on the surface side of the filmed portion. In the absorbent body 4 manufactured by such a method, the portion to which the embossed portion is applied becomes a recessed portion 8, and the synthetic fiber layer 42 and the hydrophilic fiber layer 43 are integrally joined through the recessed portion 8. There is. Thus, in the case of using the skin-side core wrap sheet 41U formed of a laminate of two original fabric sheets, 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, more preferably 20 g / m ² or less.

The skin-side core wrap sheet 41U is manufactured by a known wet paper making method using a raw material sheet of the synthetic fiber layer 42, a stock slurry containing the non-thermoplastic hydrophilic fiber 45, and a paper making net. It may be a sheet. Specifically, first, a raw sheet of synthetic fiber layer 42 is placed on a papermaking net. Next, a stock slurry containing hydrophilic fibers 45 is poured into the raw sheet on the papermaking net. The water in the poured stock slurry is sequentially transmitted through the raw sheet and the paper net and flows down from the lower side of the paper net, and the hydrophilic fibers 45 in the stock slurry are the constituent fibers of the raw sheet (thermal The plastic synthetic fiber 44) is entangled in the raw sheet, thereby forming a two-layered wet sheet containing the hydrophilic fiber 45 and the thermoplastic synthetic fiber 44 on the papermaking net. Suction means may be disposed on the opposite side of the paper sheet to the opposite side to the original sheet, and the dehydration of the original sheet may be promoted by the suction means. And the target skin side core wrap sheet 41U is manufactured by drying this wet sheet by the various drying means employ | adopted by the wet-type paper-making method. The above-described absorber 4 covers the absorbent core 40 using the skin-side core wrap sheet 41U manufactured in this manner, and the thermoplastic resin such as heat, ultrasonic waves, etc. is formed on the planned formation site of the recessed portion 8. It can be manufactured by embossing (squeezing) with a melt promoting means for promoting the melting of the synthetic fiber 44. In the absorbent body 4 manufactured by such a method, the portion to which the embossed portion is applied becomes the recessed portion 8, and the integration of the synthetic fiber layer 42 and the hydrophilic fiber layer 43 is the other than the recessed portion 8. , It is made by the entanglement of both fibers 44 and 45.

  In the skin-side core wrap sheet 41U manufactured by such a wet papermaking method, generally, the so-called wire surface side facing the papermaking net in the raw fabric sheet (the opposite side to the supply side of the stock slurry) Since the non-thermoplastic hydrophilic fiber 45 is unevenly distributed, the wire surface side becomes the hydrophilic fiber layer 43. The distribution state of the hydrophilic fibers 45 in the skin-side core wrap sheet 41U can be adjusted by appropriately adjusting the diameter, pitch, and the like of the dewatering holes of the papermaking net. In particular, after pouring the above-mentioned stock slurry containing hydrophilic fibers 45 into the raw sheet, when high-pressure water flow is sprayed to the felt side of the raw sheet, in the concave portion 8 formed by the subsequent embossing, It is preferable because the hydrophilic fiber 45 is easily exposed to the skin facing surface side or the non-skin facing surface side of the absorber 4.

  As mentioned above, although this invention was demonstrated based on the embodiment, this invention can be suitably changed, without being restrict | limited to the said embodiment.

  For example, in the diaper 1, the first recess 81 and the second recess 81 are continuous lines having an angle with the longitudinal direction X and the lateral direction Y in plan view as shown in FIGS. 1 and 3. Although it arrange | positions in the pattern which forms the crossing part 8k which cross | intersects by the recessed part 82, you may form the crossing part 8k by another pattern. For example, the recess 8 shown in FIG. 6 has a plurality of third recesses 83 continuously extending in parallel to the longitudinal direction X and a plurality of fourth recesses 84 extending continuously in parallel to the transverse direction Y. ing. In the absorber 4 shown in FIG. 6, the third recesses 83 continuously extending in parallel to the longitudinal direction X are arranged at equal intervals in the lateral direction Y, and extend continuously in parallel to the lateral direction Y Fourth recessed portions 84 are arranged at equal intervals in the longitudinal direction X, and crossing portions 8k intersecting at right angles are formed. Also by the disposable diaper provided with the absorber 4 shown in FIG. 6, the same effect as the diaper 1 described above can be obtained.

  Further, as shown in FIG. 2, the core wrap sheet 41 of the diaper 1 is made of one sheet, but the skin facing surface side of the absorbent core 40 is covered with the skin side core wrap sheet 41 U, and the non-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 materials. Good.

  In addition, from the viewpoint of improvement in absorbency, leak resistance, etc., liquid permeability made of paper or various non-woven fabrics, also called sublayer, between the surface sheet 2 and the absorber 4 (skin-side core wrap sheet 41U) A sheet may be interposed. From the same viewpoint, a groove may be formed on the skin-facing surface of the diaper 1 such that the top sheet 2 and the absorbent body 4 are integrally consolidated.

  In addition, the absorbent article of the present invention is not limited to a disposable diaper, but includes a wide range of articles used for absorbing body fluid (eg urine, soft stools, menstrual blood, sweat, etc.) discharged from the human body. Also included are disposable diapers, sanitary napkins, sanitary pants and the like.

1 Expandable disposable diaper (absorbent article)
2 top sheet 3 back sheet 4 absorber 40 absorbent core 41 core wrap sheet 41 U skin side core wrap sheet 41 D non-skin side core wrap sheet 42 synthetic fiber layer 43 hydrophilic fiber layer 44 thermoplastic synthetic fiber 45 non-thermoplastic hydrophilic Fiber 8 concave part 81 first concave part 82 second concave part 83 third concave part 84 fourth concave part 8k crossing part 1F belly side 1M crotch 1R back side X longitudinal direction Y lateral direction K space

Claims (7)

An absorbent body having a liquid-retaining absorbent core and a skin-side core wrap sheet for covering the skin-facing surface of the absorbent core, and a liquid-permeable surface sheet disposed on the skin-facing surface of the absorbent body A longitudinal direction extending from the ventral side of the wearer to the dorsal side through the crotch and a lateral direction perpendicular thereto, and a crotch disposed in the crotch and a ventral side extending in the front and back An absorbent article comprising a head and a dorsal side,
The skin-side core wrap sheet has a hydrophilic fiber layer disposed on the inner surface side in contact with the absorbent core and composed mainly of non-thermoplastic hydrophilic fibers, and an outer surface side in contact with the hydrophilic fiber layer. And a synthetic fiber layer mainly composed of a thermoplastic synthetic fiber, and the absorbent body has a recessed portion in which the skin side core wrap sheet bites into the inside of the absorbent core. And
The absorbent article, wherein the skin-side core wrap sheet has a liquid permeability in the recess that is higher than a liquid permeability in a portion other than the recess.   The absorbent article according to claim 1, wherein a space is formed between the surface sheet and the absorber in the recessed portion of the absorber. The thermoplastic synthetic fibers constituting the skin-side core wrap sheet have a hydrophilicity lower than that of the non-thermoplastic hydrophilic fibers,
In the recessed portion of the absorber, the non-thermoplastic hydrophilic fiber constituting the hydrophilic fiber layer in the skin-side core wrap sheet passes through the synthetic fiber layer on the outer surface side to face the skin facing surface of the absorber The absorbent article according to claim 1 or 2, which is exposed to the side.   The non-thermoplastic hydrophilic fibers constituting the skin-side core wrap sheet and the hydrophilic fibers contained in the absorbent material constituting the absorbent core are both wood pulp fibers. The absorbent article according to any one of the above.   The absorbent article according to any one of claims 1 to 4, wherein the density of the absorbent core is larger than the density of the portion of the absorbent core other than the concave portion in the concave portion of the absorbent body. . The basis weight of the water absorbing polymer in the recessed portion of the absorbent body is less than the basis weight of the water absorbing polymer in the portion of the absorbent core other than the recessed portion. The absorbent article as described.   A plurality of the concave portions are disposed, and the concave portions extend at an angle with respect to the longitudinal direction and the lateral direction, and form crossing portions intersecting each other. The absorbent article according to any one of Items 1 to 6.

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