JP2011200443A5 - - Google Patents

Description

Disposable absorbent article

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

A surface sheet of a disposable diaper or a disposable absorbent pad is required to have a property of preventing discomfort, rash, etc. due to excrement such as urine reattaching to the skin. Examples of such a surface sheet include those obtained by providing irregularities on the skin-side surface as shown in Patent Documents 1 and 2 and reducing the contact area of the skin.
Patent Document 1 discloses a configuration that ensures the air permeability of the topsheet by defining the amount of air permeation in the horizontal direction of the topsheet with unevenness on the skin side surface. Moreover, in patent document 2, the thickness and fiber density of a convex part and a recessed part on a surface sheet are prescribed | regulated, and it is set as the structure which the movement of the water | moisture content from a convex part to a recessed part is performed quickly.

Japanese Patent No. 3587831 Japanese Patent No. 3611838

However, only by providing irregularities on the top sheet, there is a problem that excrement having a high viscosity such as watery stool is only accumulated in the recess and cannot be efficiently transferred to the absorbent body.
Then, the main subject of this invention is providing the disposable absorbent article which transfers rapidly the excrement with high viscosity adhering to the surface sheet to an absorber.

The present invention that has solved the above problems is as follows.
<Invention of Claim 1>
In a disposable absorbent article comprising a liquid-permeable surface sheet, a liquid-impermeable sheet, an absorbent body interposed therebetween, and an intermediate sheet interposed between the surface sheet and the absorbent body ,
The surface sheet is formed by arranging a large number of recesses on the skin contact side surface at intervals, so that the portion between the bottoms of the recesses is a relatively raised projection, and the fibers are closer to the bottom of the recesses. Made of non-woven fabric with high density,
The intermediate sheet is composed of a nonwoven fabric in which a large number of apertures penetrating the front and back are arranged at intervals.
Each convex portion of the topsheet is arranged so that at least a portion thereof overlaps at least one opening of the intermediate sheet,
A sheet joint is formed by joining at least the bottom of the recess in the top sheet and the intermediate sheet,
A disposable absorbent article characterized by that.

(Function and effect)
Experiments have shown that the disposable absorbent article of the present invention can quickly absorb even high-viscosity excrement such as watery stool. The reason for this is not clear, but it is presumed that the absorption is generally performed on the following principle. That is, in the initial stage of absorption, a large amount of excrement exists on the surface sheet or is supplied one after another, so that excrement sequentially permeates through the entire surface sheet regardless of the concave or convex portions of the surface sheet. become. In such a state, if the excrement permeates only through the fiber gap of the intermediate sheet, the intermediate sheet becomes a bottleneck, and the excrement cannot be quickly moved to the absorber side. On the other hand, when a large number of apertures are provided in the intermediate sheet as described above, and each convex portion of the topsheet is arranged so that at least a portion thereof overlaps at least one of the holes, a large amount is provided via the convex portion of the topsheet. The excrement passing through one after another can be quickly moved to the absorber side through the opening.

  When excretion on the top sheet is completed and absorption proceeds to a certain extent, movement of excrement from the top sheet side to the absorber side moves from a high place to a low place by gravity (e.g. The effect of capillary action in the non-woven fabric, liquid transfer from the non-woven fabric surface to the non-woven fabric surface, or from fiber to fiber becomes strong. Even in such a state, in the present invention, after excrement on the top sheet moves to the bottom of the recess due to gravity and capillary action, it is joined to the bottom of the recess from the bottom of the recess or the surrounding back surface. It can be transferred to the intermediate sheet, can pass through the portion other than the opening of the intermediate sheet, and can quickly move to the absorber side.

  And by such a smooth movement of excrement in the whole absorption process, it becomes possible to quickly transfer excrement on the surface sheet, particularly excrement with high viscosity such as watery stool, to the absorber. Presumed to have been.

  In this invention, the recessed part and convex part of a surface sheet shall show the unevenness | corrugation seen from the skin contact side. The “open hole” in the present invention refers to a transmission hole penetrating the sheet in the thickness direction. In addition, the “water absorption” in the present invention indicates the water absorption measured by the JIS L 1907 birec method.

<Invention of Claim 2>
The disposable absorbent article according to claim 1, wherein the intermediate sheet is a nonwoven fabric having a higher water absorption than the top sheet.

(Function and effect)
Thus, if the intermediate sheet has a higher water absorption than the top sheet, the excrement can easily be transferred from the bottom of the recess or the back surface around the intermediate sheet to the intermediate sheet joined to the bottom of the recess, and the absorption rate in the late stage of absorption. Can be further improved.

<Invention of Claim 3>
The disposable absorbent article according to claim 2, wherein a gap is formed on the back side of each convex portion of the surface sheet so that the surface sheet and the intermediate sheet are separated from each other.

(Function and effect)
When the back surface of the convex portion of the surface sheet comes into contact with the intermediate sheet, the opening of the intermediate sheet may be blocked, and permeation of excrement through the opening may be obstructed. The intermediate sheet has a gap formed by separating the two sheets, for example, by not joining the intermediate sheet, so that the opening of the intermediate sheet is not easily blocked. Permeation of is difficult to be inhibited. Further, in the excrement moving form in the late stage of absorption described above, there is an advantage that excrement attached to the top sheet is easily moved from the convex portion to the periphery of the concave portion (the flow of excrement is directed).

<Invention of Claim 4>
The disposable absorbent article according to any one of claims 1 to 3, wherein the surface sheet is made of a synthetic fiber nonwoven fabric, and the recesses are formed by dot-like heat embossing.

(Function and effect)
It is preferable to form the concave portion of the topsheet by heat embossing because a structure in which the fiber density becomes higher as the bottom portion of the concave portion is approached can be easily formed.

<Invention of Claim 5>
The intermediate sheet is made of a synthetic fiber non-woven fabric, is formed into a film shape by the fused fibers at the periphery of the opening, and the fiber density increases as the periphery of the opening approaches. The disposable absorbent article according to item 1.

(Function and effect)
Such a structure can be easily formed by punching a nonwoven fabric base material of the intermediate sheet with a heated punch pin or the like.

<Invention of Claim 6>
The non-woven fabric of the top sheet is an air-through non-woven fabric having a raw fiber fineness of 1.5 to 3.3 dtex, a thickness of 0.2 to 0.8 mm, and a basis weight of 20 to 35 g / m ² .
The nonwoven fabric of the intermediate sheet is an air-through nonwoven fabric having a raw fiber fineness of 1.7 to 5.0 dtex, a thickness of 0.1 to 0.5 mm, and a basis weight of 15 to 35 g / m ² .
The disposable absorbent article according to any one of claims 1 to 5.

(Function and effect)
As the nonwoven fabric of the surface sheet and the intermediate sheet of the present invention, such an air-through nonwoven fabric is preferable.

  As described above, according to the present invention, in a disposable absorbent article having a surface sheet provided with unevenness on the skin contact surface, excrement adhered to the surface sheet, particularly excrement having a high viscosity such as watery stool. It is possible to quickly shift to the absorber.

It is a top view in the state where the diaper was developed showing the inner surface of a tape type disposable diaper. It is a top view in the state where the diaper was developed showing the outer surface of a tape type disposable diaper. FIG. 6 is a sectional view taken along line 6-6 of FIG. FIG. 7 is a cross-sectional view taken along line 7-7 in FIG. 1. FIG. 8 is a cross-sectional view taken along line 8-8 in FIG. 1. FIG. 9 is a sectional view taken along line 9-9 in FIG. 1. 3 is an enlarged surface view showing an example of a top sheet 30 and an intermediate sheet 40. FIG. FIG. 10 is a cross-sectional view taken along line 10-10 in FIG. It is a cross-sectional photograph of the joined surface sheet 30 and intermediate sheet 40.

Hereinafter, although an example of a tape type disposable diaper is drawn and explained about an embodiment of the present invention, it cannot be overemphasized that the present invention is applicable also to other types of disposable diapers, such as a pants type. In the following description, “front-rear direction (vertical direction)” means a direction connecting the ventral side (front side) and back side (rear side), and “width direction” means a direction (left-right direction) perpendicular to the front-rear direction. means direction), "vertical" and the mounted state of the diaper, i.e. the width when folded into two diaper crotch portion so as to superimpose the ventral portion sides and dorsal portions both sides of the diaper It means the direction orthogonal to the direction.

  1-6 has shown an example of the tape type disposable diaper. 3 and 4 are views showing a cross section taken along line 6-6 and 7-7 in FIG. 1, respectively, and FIGS. 5 and 6 are cross sections taken along line 8-8 and 9-9 in FIG. FIG. This tape-type disposable diaper is a part that extends from the lower abdomen through the crotch part to cover the buttocks along the center in the width direction, and a liquid-permeable surface sheet that forms the body-side surface, and the outer surface side An absorbent main body 10 that is a part where the absorbent element 50 is interposed between the liquid-impermeable sheet located in the liquid-impervious sheet, and a part that extends to the front side and the rear side of the absorbent main body part 10 respectively, and It has a ventral end flap part FE and a dorsal end flap part BE, which are parts that do not have the absorbent element 50.

  Further, this tape-type disposable diaper has a pair of abdominal side flap portions FF, FF extending to the outside in the width direction from the crotch portion C on both sides of the upper edge side portion of the abdominal side F, and On both sides of the edge portion, a pair of back side flap portions BF, BF extending to the outside in the width direction from the crotch portion C are provided. Moreover, the fastening tape 13 as a locking member is provided in the back side flap part BF and BF, respectively.

  More specifically, the entire outer surface of the absorbent main body 10 and the side flap portions BF and FF on the back side and the abdomen side is formed by the exterior sheet 12. In particular, in the absorbent main body 10, a liquid-impermeable sheet 11 is fixed to the inner surface side of the exterior sheet 12 with an adhesive such as a hot-melt adhesive, and an absorbent element is further disposed on the inner surface side of the liquid-impermeable sheet 11. 50, the intermediate sheet 40, and the top sheet 30 are laminated in this order. The top sheet 30 and the liquid-impermeable sheet 11 are rectangular in the illustrated example, have a slightly larger dimension in the front-rear direction and the width direction than the absorbent element 50, and are eaten from the side edges of the absorbent element 50 in the top sheet 30. The peripheral edge that protrudes and the peripheral edge that protrudes from the side edge of the absorbent element 50 in the liquid-impermeable sheet 11 are fixed by a hot melt adhesive or the like. The liquid-impermeable sheet 11 is made of a moisture-permeable polyethylene film or the like, and is formed to be slightly wider than the top sheet 30.

  Further, side barrier cuffs 60, 60 projecting (standing) on the skin side of the wearer are provided on both sides of the absorbent main body 10, and a barrier sheet forming the side barrier cuffs 60, 60 is provided. 62 and 62 are extended over the whole width direction outer side of the absorptive main-body part 10 including the inner surface of each side flap part BF and FF of back side and abdominal side.

Hereinafter, the material and the characteristic part of each part are demonstrated in order.
(Exterior sheet)
The exterior sheet 12 is a part that supports the absorbent element 50 and is attached to the wearer. The exterior sheet 12 has an hourglass shape in which the center part in the front-rear direction on both sides is constricted, and this is a part into which the wearer's leg is placed.

The exterior sheet 12 is preferably a non-woven fabric, but is not limited thereto. The type of the nonwoven fabric is not particularly limited, and as the material fiber, for example, synthetic fibers such as polyethylene or polypropylene, synthetic fibers such as polyester or polyamide, recycled fibers such as rayon or cupra, and natural fibers such as cotton are used. As a processing method, a spunlace method, a spunbond method, a thermal bond method, an air-through method, a needle punch method, or the like can be used. However, a long-fiber nonwoven fabric such as a spunbond nonwoven fabric, an SMS nonwoven fabric, or an SMMS nonwoven fabric is preferable in that both the touch and strength can be achieved. In addition to using a single nonwoven fabric, a plurality of nonwoven fabrics can be used. In the latter case, the nonwoven fabrics 12 are preferably bonded to each other with a hot melt adhesive or the like. When using a nonwoven fabric, the fabric weight is preferably 10 to 50 g / m ² , particularly 15 to 30 g / m ² .

(Liquid impervious sheet)
The material of the liquid-impermeable sheet 11 is not particularly limited. For example, the liquid-impermeable sheet 11 is substantially made of an olefin resin such as polyethylene or polypropylene, a laminated nonwoven fabric obtained by laminating a nonwoven fabric on a polyethylene sheet, or a waterproof film. Non-woven fabrics that ensure liquid impermeability (in this case, liquid impervious sheets are composed of waterproof films and non-woven fabrics). Of course, in addition to this, a liquid-impermeable and moisture-permeable material that has been used and used in recent years from the viewpoint of preventing stuffiness can also be exemplified. As the sheet of the material having liquid impermeability and moisture permeability, for example, an inorganic filler is kneaded in an olefin resin such as polyethylene or polypropylene, and the sheet is formed, and then stretched in a uniaxial or biaxial direction. Examples of the microporous sheet obtained in this way can be given. In addition, non-woven fabric using micro-denier fiber, strengthening leak-proofing by reducing the voids of the fiber by applying heat or pressure, and applying water-absorbing resin or hydrophobic resin or water repellent. A sheet that is liquid-impermeable without using a film can also be used as the liquid-impermeable sheet 11.

(Surface sheet)
As the top sheet 30, a non-woven fabric is used. It is more preferable to use a non-porous nonwoven fabric. The raw material fibers of the nonwoven fabric are not particularly limited, but it is preferable to use synthetic fibers capable of heat embossing such as olefins such as polyethylene and polypropylene, polyesters, and polyamides. Furthermore, as a method for processing the nonwoven fabric, any known method such as a spun lace method, a spun bond method, a thermal bond method, a melt blown method, a needle punch method, an air through method, a point bond method and the like can be used. The use of the air-through method having bulkiness is particularly preferred.

An enlarged view of the skin contact surface of the top sheet 30 is shown in FIG. The skin contact surface side of the topsheet 30 has an uneven shape. The surface sheet 30 may have an uneven shape on the entire skin contact side surface, or only the wearer's excretion opening contact portion (particularly the anus contact portion) may have an uneven shape. As a method of providing the uneven shape on the nonwoven fabric of the topsheet, any of publicly known methods such as a method of forming with a mesh pattern at the time of nonwoven fabric formation and a method of imparting the recess 81 to the formed nonwoven fabric by heat embossing can be used. Since the fiber density needs to be higher in the concave portion than in the convex portion, it is desirable to provide irregularities on the surface sheet by a method involving compression, particularly heat embossing. In particular, in the case of heat embossing, the flexibility of the surface sheet is easily impaired in the concave portion 81, and therefore the concave portion 81 is preferably formed so that the area thereof is smaller than the area of the convex portion (portion other than the concave portion 81). . The shape of the heat embossing is not particularly limited, but dot-like embossing can be suitably used as in the illustrated example. When the recess 81 is formed by dot-like embossing, the diameter 81r of the recess 81 is preferably 0.5 to 2.0 mm, particularly preferably 1.0 to 1.5 mm. Moreover, it is preferable that the space | interval 81d of the recessed part 81 is 0.5-4.0 mm, especially 1.0-3.0 mm.

The nonwoven fabric constituting the top sheet 30 is preferably one having a basis weight of 20 to 35 g / m ² . If the basis weight is lower than 20 g / m ^2, it is difficult to make a difference in uneven portions due to heat embossing. If the basis weight is higher than 35 g / m ² , the thickness of the convex portion increases, and the liquid is easily retained in the convex portion. The thickness of the topsheet 30 is preferably 0.2 to 0.8 mm, particularly 0.3 to 0.6 mm. Moreover, the fiber length of the fiber which comprises a nonwoven fabric shall be 35-60 mm (more preferably 40-55 mm), and the fineness shall be 1.5-3.3 dtex (more preferably 2.2-2.8 dtex). preferable.

The Clark stiffness (JIS P 8143 (1996)) of the nonwoven fabric constituting the top sheet 30 is preferably 60 to 100, particularly preferably 70 to 85. If the stiffness is higher than 100, the flexibility of the skin contact surface is impaired, and the wearing feeling is inferior. On the other hand, if it is lower than 60, the concavo-convex shape is difficult to be held, and it tends to be crushed. The top sheet 30 may be composed of one sheet or two or more sheets in the planar direction.

(Intermediate sheet)
An intermediate sheet (also referred to as a second sheet) 40 is provided between the top sheet 30 and the absorbent element 50 in order to move excrement that has passed through the top sheet 30 to the absorber and prevent reversal.
The intermediate sheet 40 is composed of a non-woven fabric having a higher water absorption (JIS L 1907 Bayrec method) than the top sheet 30. The non-woven fabric of the intermediate sheet 40 may be a fiber material that is more hydrophilic than the non-woven fabric of the top sheet 30, or may be the same material as the top sheet 30 provided with a hydrophilic agent. Although it is good, when a perforation process is performed later, it is preferable to use a synthetic fiber. As a processing method of the nonwoven fabric nonwoven fabric constituting the intermediate sheet 40, any known method such as a spunlace method, a spunbond method, a thermal bond method, a melt blown method, a needle punch method, an air through method, a point bond method, etc. is used. However, it is particularly preferable to use an air-through method having bulkiness.

An enlarged view of the surface of the intermediate sheet 40 is shown in FIG. The intermediate sheet 40 has a large number of apertures 92. The opening may be provided by a mesh pattern at the time of forming the nonwoven fabric, but is preferably provided by a punching process using a heated punching pin (for example, a process using a punching device disclosed in JP-A-6-238597). By performing the perforating process with the perforating pins, the fibers at the periphery of the opening are melted to form a film, and the density of the surrounding fibers becomes denser than other parts. Therefore, the excrement reaching the intermediate sheet 40 is caused by capillary action. It is easy to shift to the peripheral edge of the aperture.

The opening 82 may be disposed on the entire intermediate sheet 40 as in the illustrated example, or may be disposed only on the wearer's excretion opening contact portion (particularly the anus contact portion). The diameter 82r of the opening 82 is preferably 0.1 to 1.0 mm, particularly preferably 0.4 to 0.8 mm. Moreover, it is preferable that the space | interval 82d of the opening 82 is 1.0-5.0 mm (more preferably 1.5-3.5 mm) and smaller than the space | interval 81d of the recessed part 81 of the surface sheet 30. FIG. It is preferable that more openings 82 exist than the recesses 81 at the portions where the openings 82 are provided. In particular, when the apertures 82 are formed by perforated pins, since a large number of the fibers in the vicinity of the aperture periphery increase due to the large number of apertures 82, the excretion from the topsheet 40 to the intermediate sheet 30 is further increased. It is thought that things are easy to move. Moreover, the transfer of the excrement having high viscosity to the absorber can be made quicker.

As the nonwoven fabric used for the intermediate sheet 40, a nonwoven fabric having a higher fiber density than the nonwoven fabric of the top sheet 30 is used. The basis weight of the intermediate sheet 40 is preferably 15 to 35 g / m ² , particularly 18 to 25 g / m ² . The thickness of the intermediate sheet 40 is preferably 0.1 to 0.5 mm, particularly preferably 0.1 to 0.4 mm. The fiber length of the fibers constituting the nonwoven fabric is 35 to 60 mm (more preferably 40 to 55 mm), and the fineness is 1.7 to 5.0 dtex (more preferably 1.7 to 2.8 dtex). preferable.

  The Clark stiffness (JIS P 8143 (1996)) of the nonwoven fabric constituting the intermediate sheet 40 is preferably 30 to 80, particularly 30 to 60, and is preferably lower than the top sheet 30. If the stiffness is higher than 80, the unevenness caused by partial joining with the topsheet 30 becomes large, and the contact area with the absorber 56 (or the packaging sheet 58) becomes small, so that the absorption efficiency may be reduced. There is. On the other hand, if it is lower than 30, the feeling of thickness required for the intermediate sheet is impaired.

  The intermediate sheet 40 in the illustrated form has the same width as the top sheet 30, but may be shorter than the width of the absorbent element 50 and disposed only in the center. The length in the longitudinal direction of the intermediate sheet 40 may be the same as the entire length of the diaper, may be the same as the length of the absorbent element 50, or may be within a short length range centered on the region that receives the liquid.

(Join surface sheet and intermediate sheet)
FIG. 8 shows an enlarged cross-sectional view showing a joined state between the top sheet 30 and the intermediate sheet 40. As shown in FIG.
The intermediate sheet 40 is joined at the concave portion 81 of the top sheet 30. As a joining method, known methods such as adhesion by hot melt adhesive, spunlace, heat embossing, ultrasonic welding, etc. can be used, but heat embossing having an advantage that it is easy to join only to a target portion is preferable. Can be used. When heat embossing is used as a joining means, it is preferable to use a material having a melting point comparable to that of the top sheet 30 as the material of the intermediate sheet 40. It is preferable that the surface sheet and the intermediate sheet are bonded in all the recesses, but may have a portion that is not bonded.

  On the other hand, it is desirable that a portion corresponding to the convex portion 83 of the topsheet 30 is not joined, and a gap 84 is provided between the topsheet 30 and the intermediate sheet 40. A method of providing the gap 84 is as follows. The top sheet 30 and the intermediate sheet 40 are joined to the intermediate sheet 40 only by the concave portions 81 of the top sheet 30 by heat embossing. At the time of joining, a tensile force stronger than that of the surface sheet 30 is applied to the intermediate sheet 40 in one or both of the product width direction and the product length direction. After the joining, the intermediate sheet 40 released from the tensile force contracts, so that the unjoined portion (projection 83) of the topsheet 30 is lifted away from the intermediate sheet 40 and separated.

  When the surface sheet 30 and the intermediate sheet 40 are joined by heat embossing, irregularities are also generated on the side surface of the absorber of the intermediate sheet 40. Since it is preferable to make the contact area between the intermediate sheet 40 and the absorbent body 56 (or the packaging sheet 58) as large as possible, the intermediate sheet 40 is absorbed as much as possible, such as fixing the intermediate sheet 40 to a smooth support during heat embossing. It is preferable to take measures that do not cause unevenness on the side of the body.

By adopting such a structure, the excrement that has reached the convex portion 83 of the topsheet 30 can easily move to the periphery of the concave portion 81, and the topsheet 30 can be uneven to reduce the skin contact area. It is considered that there is an advantage that the cushioning property of the seat can be increased.

(Side barrier cuffs)
Side barrier cuffs 60, 60 that protrude (stand up) on the use surface side are provided on both sides of the product in order to prevent urine and soft stool that move laterally on the top sheet 30 and prevent side leakage. Is preferred.

  The side barrier cuff 60 includes a barrier sheet 62 that is substantially continuous in the width direction, and an elongated elastic elastic member 63 that is fixed to the barrier sheet 62 in a stretched state along the front-rear direction. As the barrier sheet 62, a water-repellent nonwoven fabric can be used, and as the elastic elastic member 63, thread rubber or the like can be used. As shown in FIGS. 1 and 2, a plurality of elastic elastic members can be provided in addition to a plurality of elastic expansion members.

  The inner surface of the barrier sheet 62 has a fixing start end in the width direction on the side portion of the top sheet 30, and a portion on the outer side in the width direction from the fixing start end is on the side portion of the liquid-impermeable sheet 11 and on the outer side in the width direction. It fixes to the side part of the exterior sheet | seat 12 located with the hot-melt-adhesive agent etc. Out of the adhering portions, on the outer side in the width direction in the vicinity of the adhering start end, leg elastic elastic members 64 made of rubber thread or the like are provided along the front-rear direction between the sheets of the portions where the barrier sheet 62 and the exterior sheet 12 face each other. It has been.

  Around the leg, the width direction inner side of the side barrier cuff 60 is fixed on the top sheet 30 at both ends in the longitudinal direction of the product, but the portion between them is an unfixed free part. The portion comes to stand by the contraction force of the rubber thread 63. When the diaper is worn, the diaper is attached to the body in the shape of a boat, and the contraction force of the rubber thread 63 acts, so that the side barrier cuffs 60 stand up and adhere to the legs around the contraction force of the rubber thread 63. . As a result, so-called side leakage from around the legs is prevented.

  Unlike the illustrated embodiment, the front and rear direction end portions of the barrier sheet 62 on the inner side in the width direction are divided into a base end side portion extending from the outer side in the width direction to the inner side in the width direction and a center side in the width direction of the base end side portion. It is also possible to fix in a double-folded state having a distal end side portion that is folded back from the edge toward the body side and extends outward in the width direction, and the portion in between can be an unfixed free portion.

(Absorption element)
The absorption element 50 is a part that absorbs and holds liquid such as urine and loose stool. The absorbent element 50 includes an absorbent body 56 and a packaging sheet 58 that wraps at least the back and side surfaces of the absorbent body 56. The packaging sheet 58 can be omitted. The absorbent element 50 can be adhered to the inner surface of the liquid-impermeable sheet 11 via an adhesive such as a hot melt adhesive on the back surface.

(Absorber)
The absorber 56 can be formed of an aggregate of fibers. As this fiber assembly, a filament assembly obtained by opening, as necessary, synthetic fiber tows (fiber bundles) such as cellulose acetate as well as short fibers such as cotton-like pulp and synthetic fibers Can also be used. The fiber basis weight can be set to, for example, about 100 to 300 g / m ² when cotton-like pulp or short fibers are stacked, and in the case of a filament aggregate, for example, about 30 to 120 g / m ^2. Can do. The fineness in the case of a synthetic fiber is 1-16 dtex, for example, Preferably it is 1-10 dtex, More preferably, it is 1-5 dtex. In the case of a filament aggregate, the filament may be a non-crimped fiber, but is preferably a crimped fiber. The crimped degree of the crimped fiber can be, for example, 5 to 75, preferably 10 to 50, and more preferably about 15 to 50 per inch. Further, a crimped fiber that is uniformly crimped is often used.

(Superabsorbent polymer particles)
The absorbent body 56 preferably includes superabsorbent polymer particles. In particular, at least in the liquid receiving region, the superabsorbent polymer particles (SAP particles) are dispersed substantially throughout the thickness direction with respect to the aggregate of fibers. Is desirable.

When there is no SAP particle in the upper part, the lower part, and the intermediate part of the absorber 56, or there are very few, it cannot be said that it is "dispersed in the whole thickness direction". Therefore, “distributed in the entire thickness direction” means “distributed unevenly in the upper part, the lower part, and / or the middle part of the aggregate of fibers in addition to the form“ uniformly ”distributed in the entire thickness direction. However, it is still included in the form of being dispersed in the upper, lower and middle portions. Further, a form in which some SAP particles do not enter the fiber assembly and remain on the surface thereof, and a form in which some SAP particles pass through the fiber assembly and are on the packaging sheet 58 are also excluded. It is not something.

  Superabsorbent polymer particles include “powder” in addition to “particles”. As the particle diameter of the superabsorbent polymer particles, those used in this type of absorbent article can be used as they are, and those having a particle size of 1000 μm or less, particularly 150 to 400 μm are desirable. The material of the superabsorbent polymer particles can be used without any particular limitation, but those having a water absorption of 40 g / g or more are suitable. High-absorbent polymer particles include starch-based, cellulose-based, and synthetic polymer-based starch-acrylic acid (salt) graft copolymers, saponified starch-acrylonitrile copolymers, and sodium carboxymethylcellulose crosslinks. Or an acrylic acid (salt) polymer can be used. As the shape of the superabsorbent polymer particles, a commonly used granular material is suitable, but other shapes can also be used.

  As the superabsorbent polymer particles, those having a water absorption rate of 40 seconds or less are preferably used. When the water absorption speed exceeds 40 seconds, so-called reversion in which the liquid supplied into the absorber 56 returns to the outside of the absorber 56 is likely to occur.

The basis weight of the superabsorbent polymer particles can be appropriately determined according to the amount of absorption required for the use of the absorber 56. Therefore, although it cannot be said unconditionally, it can be set to 50 to 350 g / m ² . If the amount of polymer is less than 50 g / m ^2, it is difficult to secure the absorption amount. When it exceeds 350 g / m ² , not only the effect is saturated, but also the sensation of incongruity due to the excess of the superabsorbent polymer particles is given.

(Packaging sheet)
When the packaging sheet 58 is used, as the material, tissue paper, particularly crepe paper, non-woven fabric, polylaminated non-woven fabric, a sheet with small holes, or the like can be used. However, it is desirable that the superabsorbent polymer particles be a sheet that does not escape. When a nonwoven fabric is used in place of the crepe paper, a hydrophilic SMMS (spunbond / meltblown / meltblown / spunbond) nonwoven fabric is particularly suitable, and polypropylene, polyethylene / polypropylene, etc. can be used as the material. The fiber basis weight is preferably 5 to 40 g / m ² , particularly 10 to 30 g / m ² .

  As shown in FIG. 3, the packaging sheet 58 may wrap only the back surface and the side surface of the layer in addition to the form for wrapping the entire absorbent body 56. Although not shown, only the upper and side surfaces of the absorbent body 56 are covered with crepe paper or a nonwoven fabric, and the lower surface is covered with a liquid-impermeable sheet such as polyethylene, and the upper surface of the absorbent body 56 is covered with crepe paper or a nonwoven fabric. For example, the lower surface may be covered with a liquid-impermeable sheet such as polyethylene (each of these materials is a component of the packaging sheet). If necessary, the absorbent body 56 may be sandwiched between two upper and lower sheets or disposed only on the lower surface, but this is not desirable because it is difficult to prevent the movement of the superabsorbent polymer particles.

(Fastening tape)
As shown in FIGS. 1 and 2, the fastening tape 13 has a base portion of a sheet base material 13C made of a nonwoven fabric, a plastic film, a polylaminated nonwoven fabric, paper or a composite material thereof attached to the diaper and protrudes from the diaper. A hook material 13 </ b> A of a mechanical fastener is provided as a locking portion for the ventral side at the distal end side portion. The hook material 13A is joined to the sheet base 13C with an adhesive so as not to be peeled off.

In the diaper for infants, among the dimensions of the attachment portion of the fastening tape 13, the width direction length X1 of the diaper is preferably 10 to 50 mm, particularly preferably 20 to 40 mm, and the length Y1 in the front-rear direction is 20 to 100 mm. In particular, the thickness is preferably 40 to 80 mm. Of the dimensions of the front end side portion of the fastening tape 13, the length of the diaper in the width direction is preferably 30 to 80 mm, particularly preferably 40 to 60 mm, and the length (height) in the front-rear direction is 20 to 70 mm. In particular, it is preferably 25 to 50 mm. In addition, when a part or all of the fastening tape 13 has a substantially tapered shape, for example, and the length in the front-rear direction and the length in the width direction are not constant, the numerical range is determined by an average value. The shape of the fastening tape 13 may be a left-right symmetric shape such as a rectangular shape. However, if the fastening tape 13 is a convex shape composed of a wide attachment portion and an elongated tip-side portion, the knob on the tip-side portion can be easily picked and This is preferable because the tension between the bases of this region acts over a wide range. The hook member 13A has a large number of engaging protrusions on the outer surface side. The shape of the engaging protrusion is (A) Le-shaped, (B) J-shaped, (C) Mushroom-shaped, (D) T-shaped, (E) Double J-shaped (J-shaped And the like may be any shape. Instead of the hook material 13 </ b> A, an adhesive material layer can be provided as a locking portion of the fastening tape 13.

  When the diaper is mounted, the fastening tape is locked at a proper position on the outer surface of the abdominal side F with the back side flap portion BF being overlapped on the outside of the abdominal side flap portion FF. The position and size of the fastening portion of the fastening tape 13 can be arbitrarily determined. In diapers for infants, the locking location is a rectangular range of 20 to 80 mm in the front-rear direction and 150 to 300 mm in the width direction, and the distance in the height direction between the upper edge and the ventral upper edge is 0 to 60 mm, particularly 20 to 50 mm. And the center in the width direction of the product.

When the fastening tape 13 is attached so that the attachment portion of the fastening tape 13 overlaps the boundary line between the back end flap portion BE and the absorbent element 50, the tension acting between the attachment portions of the left and right fastening tapes 13 when the diaper is attached. This is preferable because the back side end of the absorbent element 50 is firmly pressed against the body. Moreover, if the attachment part of the fastening tape 13 is too far from the back side end part (rear end part) of the diaper, the tension acting between the attachment parts of the left and right fastening tapes 13 when the diaper is mounted is the back side end part of the diaper. Therefore, a gap is likely to occur between the back end of the diaper and the body surface. Therefore, the length in the front-rear direction of the back end flap BE is preferably the same as or shorter than the length in the front-rear direction of the base portion of the fastening tape 13.

(Target sheet)
It is preferable to provide a target sheet 74 having a target for facilitating the locking at the locking position of the fastening tape 13 on the ventral side F. As the target sheet 74, when the hook portion is the hook material 13 </ b> A, a target sheet 74 can be used in which a large number of loop yarns are formed on the surface of a sheet base material made of a plastic film or a nonwoven fabric so that the engagement protrusions of the hook material are entangled. In the case of an adhesive material layer, a sheet base material made of a plastic film having a smooth surface that is rich in adhesiveness can be used. Further, when the fastening portion of the fastening tape 13 on the ventral side F is made of a nonwoven fabric, for example, when the exterior sheet 12 of the illustrated form is made of a nonwoven fabric and the fastening portion of the fastening tape 13 is a hook material 13A, The target sheet 74 can be omitted, and the hook material 13A can be entangled with the nonwoven fabric of the exterior sheet 12 and locked. In this case, the target sheet 74 may be provided between the exterior sheet 12 and the liquid-impermeable sheet 11.

(End flap)
The end flap part is a part that extends to the front side and the rear side of the absorbent main body 10 and does not have the absorbent element 50, and the front extension part is the ventral end flap part FE. The extended portion on the rear side is the back end flap portion BE.

The length in the front-rear direction of the back end flap BE is preferably the same as or shorter than the length in the front-rear direction of the attachment portion of the fastening tape 13 for the reasons described above. If too close, the thickness and stiffness of the absorbent element 50 liable to occur a gap between the diaper back side end of the body surface, it is preferable to 10mm or more.

  The length in the front-rear direction of the ventral end flap part FE and the back end flap part BE is preferably about 5 to 20% of the length L in the front-rear direction of the whole diaper. In particular, a thickness of 20 to 50 mm is appropriate.

(Back elastic sheet)
In the illustrated form, a belt-like back-side elastic sheet 70 that elastically expands and contracts in the width direction is provided between the fastening tapes 13 to improve the fit in the diaper back side. Both end portions of the back-side elastic sheet 70 are preferably extended to a portion that overlaps with the attachment portions of both fastening tapes 13, but may be separated to the center in the width direction. The back-and-forth stretchable sheet 70 has a front-rear dimension that is approximately the same as the front-rear dimension of the attachment portion of the fastening tape 13, but may have a dimensional difference of about ± 20%. Further, when the back elastic sheet 70 is arranged so as to overlap the boundary line between the back end flap BE and the absorbent element 50 as shown, the back end of the absorbent element 50 is firmly pressed against the body. Therefore, it is preferable. The back-side elastic sheet 70 may use a sheet-like elastic member such as a rubber sheet, but it is preferable to use a nonwoven fabric or paper from the viewpoint of air permeability. In this case, a sheet-like elastic member having air permeability such as a stretchable nonwoven fabric can be used. However, as shown in FIG. 5, the sheet base material 71 such as two nonwoven fabrics is bonded with an adhesive such as a hot melt adhesive. Preferably, the elastic stretch member 72 such as a perforated sheet, net, or elongated (thread or string) is fixed in a stretched state in the width direction between the sheet bases 71. Used. As the sheet base 71 in this case, the same one as the exterior sheet 12 can be used. It is preferable that the elastic expansion / contraction member 72 has an extension ratio of about 150 to 250%. In addition, when an elongated (stretch or string-like) member is used as the elastic elastic member 72, it is preferable to provide about 5 to 15 members having a thickness of 420 to 1120 dtex at intervals 72d of 3 to 10 mm.

  In addition, it is preferable that a part of the elastic expansion / contraction member 72 is arranged so as to cross the absorbent element 50 as shown in the figure because the fitting property of the absorption element 50 is improved, but in this case, the elastic expansion / contraction member 72 is used. If the contraction force is prevented from acting on a part or all of the overlapping portion by means such as cutting, the back end of the absorbent element 50 does not contract in the width direction, so that the fit is further improved.

  The elastic elastic member 72 may be fixed over the entire length of the sheet base material 71 in the longitudinal direction of the sheet (width direction of the diaper), but in order to prevent the sheet from shrinking or curling when attached to the diaper body, In the range of about 5 to 20 mm at the end in the front-rear direction (diaper width direction), it is preferable that the contraction force does not work or the elastic elastic member 72 does not exist.

  In the illustrated embodiment, the back-side stretchable sheet 70 is sandwiched between the barrier sheet 62 and the exterior sheet 12 on both sides in the width direction of the liquid-impermeable sheet 11 and overlaps with the liquid-impermeable sheet 11. Although provided so as to be sandwiched between the permeable sheet 11 and the absorbent element 50, it may be provided between the liquid-impermeable sheet 11 and the exterior sheet 12, or provided on the outer surface of the exterior sheet 12. Alternatively, it may be provided between the top sheet 30 and the absorbent element 50. Further, the back-side elastic sheet 70 may be provided on the top sheet 30, and in this case, it may be provided on the barrier sheet 62 on both sides in the width direction of the liquid-impermeable sheet 11. Further, when the exterior sheet 12 is formed by stacking a plurality of sheet base materials, the entire back-side stretchable sheet 70 may be provided between the sheet base materials of the exterior sheet 12.

The present invention can be applied to a wide range of uses such as a pants-type, tape-type, or pad-type absorbent article.

  DESCRIPTION OF SYMBOLS 11 ... Liquid impervious sheet, 12 ... Exterior sheet, 30 ... Surface sheet, 40 ... Intermediate sheet, 50 ... Absorbing element, 56 ... Absorber, 58 ... Packaging sheet, 60 ... Side barrier cuff, 62 ... Barrier sheet, DESCRIPTION OF SYMBOLS 70 ... Back side elastic sheet, 74 ... Target sheet, 81 ... Surface sheet recessed part, 82 ... Intermediate sheet opening, 83 ... Surface sheet convex part, 84 ... Space | gap.