JP2012179068A - Disposable diaper - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a disposable diaper with a flexible texture on touch while it is lightweight and rich in cushioning properties.SOLUTION: In the disposable diaper, a liquid impermeable sheet 11, as shown in Figure 7, has a surface on which a number of openings of recessed parts 14 are arranged by certain intervals and a back surface on which a number of projecting parts of the recessed parts 14 are arranged by certain intervals by arranging a number of cup-shaped recessed parts 14 recessed from the surface to the back surface by intervals. A packaging sheet 58 forming the bottom face of an absorbing element 50 is not joined with the recessed parts 14 of the surface of the liquid impermeable sheet 11 but is joined with the parts except the recessed parts 14 of the surface by joining parts 81, and the insides of the recessed parts 14 of the surface are made to be spaces 83, and the inner face of the sheathing sheet 12 is not joined with the spaces among the projecting parts of the recessed parts 14 of the back surface of the liquid impermeable sheet 11, but is joined with the bottom parts 14b of the recessed parts 14 of the back surface by joining parts 82, and the spaces among the projecting parts of the recessed parts 14 of the back surface are made to be spaces 84.

Description

  The present invention relates to a disposable diaper that is flexible in touch and rich in breathability.

  The disposable diaper includes a liquid-permeable top sheet that forms the body-side surface, a liquid-impermeable sheet made of a resin film located on the back side thereof, and the liquid-permeable top sheet and the liquid-impermeable sheet. Interstitial absorbent body as a basic element, liquid impervious sheet constituting the back of the diaper, and liquid impervious sheet back surface bonded with a non-woven fabric outer sheet with a hot melt adhesive (for example, (See Patent Document 1).

  Although the latter has the advantage that the outer surface of the diaper has a cloth-like texture, the liquid impervious sheet and the exterior sheet are bonded together by a hot melt adhesive, so that there is a problem that the texture is hard and the cushioning property is poor. It was.

  Of these, if it is only cushioning, it can be solved by inserting an air cushion as shown in Patent Documents 2 and 3, but in that case, the problem that the diaper weight increases due to the increase in the number of materials, the material of the cushion material There is a problem that the texture becomes hard due to the influence of the hardness.

JP-A-2005-319142 JP 2008-86496 A Japanese Patent Laid-Open No. 10-28697

  Then, the main subject of this invention is providing the disposable diaper which has a soft texture while being lightweight and rich in cushioning properties.

The present invention that has solved the above problems is as follows.
<Invention of Claim 1>
A liquid-permeable top sheet that forms the body-side surface; a liquid-impermeable sheet; and an absorbent element that absorbs and holds excrement disposed between the liquid-permeable top sheet and the liquid-impermeable sheet; In a disposable diaper provided with an exterior sheet made of a nonwoven fabric bonded to the back surface of a liquid-impermeable sheet with a hot melt adhesive,
The liquid-impermeable sheet has a plurality of cup-shaped recesses that are recessed from either the front or the back to the other, with a large number of the recesses being arranged at intervals, whereby the first surface has a large number of openings of the recesses arranged at intervals. The projecting portion of the recess has a second surface arranged in a large number at intervals,
Of the exterior sheet and the absorbent element, the one in contact with the first surface of the liquid-impermeable sheet is joined to a portion other than the concave portion of the first surface without being joined to the concave portion of the first surface, The recess in the first surface is a space,
Of the exterior sheet and the absorbent element, the one in contact with the second surface of the liquid-impermeable sheet is not joined with the protruding portion of the recess of the second surface, and the bottom of the recess of the second surface Joined and the space between the protrusions of the recesses on the second surface is a space,
A disposable diaper characterized by that.

(Function and effect)
As described above, the liquid-impermeable sheet is formed into a sheet having a large number of recesses, and when the front and back surfaces are joined to the opposing member, the inside of the recesses and the protrusions of the recesses are joined by excluding the portion between the protrusions of the recesses and the recesses. If there is a space, the joint portion of the exterior sheet is reduced without adding new material, the outer surface becomes softer, and there is an air layer in the recess and between the protruding portions of the recess, and the cup. When the concave portion is crushed and restored in the thickness direction like a spring, the liquid-impermeable sheet itself becomes a cushioning material and the cushioning property is increased.
Moreover, since disposable diapers are folded at the time of manufacture and a large number of sheets are collected and stored in a packaging bag in a compressed state in the stacking direction, how thin the diaper is is very important. In the case of the present invention, the portion exhibiting cushioning properties, that is, the cup-shaped recess of the liquid-impermeable sheet can be crushed to the same thickness as the sheet thickness, so the thickness at the time of packaging does not matter, and the cup-shaped when used The concave portion is restored (not meant only for complete restoration) and exhibits cushioning properties.
Moreover, in the case of this invention, since a big ventilation space is ensured on the front and back both sides of a liquid-impermeable sheet, it will also be excellent in air permeability.
Further, in addition to this improvement in air permeability, the contact area between the liquid-impermeable sheet and the absorbent element, and the contact area between the liquid-impermeable sheet and the exterior sheet are both reduced, and the liquid-impervious sheet and the absorbent sheet are collected. The joint between the element and the joint between the liquid-impermeable sheet and the exterior sheet do not overlap. To reduce.

<Invention of Claim 2>
The disposable diaper according to claim 1, wherein the concave portion of the liquid-impermeable sheet has a cup shape that is recessed from the front side to the back side.

(Function and effect)
Thereby, on the front side (top sheet side) of the liquid-impermeable sheet, spaces in the recesses are scattered independently of each other by the number of the recesses, and on the back side (exterior sheet side) of the liquid-impermeable sheet, Regardless of the number of recesses, a space between the protruding portions of the recesses is continuously formed. Therefore, urine that has reached the surface of the liquid-impermeable sheet, fibers spilled from the absorbent element, and superabsorbent polymer can be captured in the recesses on the surface of the liquid-impermeable sheet to prevent diffusion and movement. it can. Further, the air permeability between the liquid-impermeable sheet and the exterior sheet is further improved, and the effect of reducing the above-described humidity feeling is further enhanced.

<Invention of Claim 3>
The disposable diaper according to claim 2, wherein a bonding area of the second surface of the liquid-impermeable sheet is smaller than a bonding area of the first surface of the liquid-impermeable sheet.

(Function and effect)
Thereby, while the shape of a recessed part can be maintained firmly, the texture of an outer surface becomes still more flexible.

<Invention of Claim 4>
The disposable diaper according to claim 2 or 3, wherein at least one of a fiber assembly and a superabsorbent polymer particle is accommodated in the recess.

(Function and effect)
As a result, the amount of vapor passing through the liquid-impermeable sheet is reduced, and since the cushioning material is provided in the concave portion, the restorability of the concave portion is improved, and the urine that reaches the surface of the liquid-impermeable sheet is diffused. Without being absorbed, and the absorption performance of the absorbent element can be supplemented.

<Invention of Claim 5>
It is a tape-type disposable diaper that is worn by connecting the fastening tape provided on both sides of the dorsal part to the outer surface of the ventral part,
In the connection part of the fastening tape in the ventral part, no recess is formed in the liquid-impermeable sheet, and the liquid-impermeable sheet and the exterior sheet are joined in a continuous contact state. The disposable diaper according to any one of claims 1 to 4.

(Function and effect)
In such a tape-type disposable diaper, the cushioning property of the fastening tape connecting portion in the abdominal part is high, and if it is easily deformed, tightening around the waist is easy to loosen or the fastening tape is easily disconnected. There is a risk. Therefore, as described above, it is desirable to firmly join the liquid-impermeable sheet without forming a recess at the fastening tape connecting portion.

  As described above, according to the present invention, there are advantages such as being lightweight and rich in cushioning properties but having a soft texture.

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. It is a principal part fracture perspective view of a liquid impermeable sheet. FIG. 6 is a cross-sectional view taken along line 6-6 of FIG. 1 showing another embodiment.

  Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings. Note that “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) orthogonal to the front-rear direction. The “vertical direction” means a wearing state of the diaper, that is, a direction orthogonal to the width direction when the diaper is folded in two at the crotch portion so that the abdomen portion and the back portion of the diaper are overlapped. Further, the term “elongation rate” means a value when the natural length is 100%. Furthermore, the dot pattern (shaded) portion in the cross-sectional view shows a joining portion for joining the constituent members, and is formed by solid, bead, curtain, summit or spiral application such as hot melt adhesive. .

  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. The code | symbol X in the figure has shown the full width of the diaper except a fastening tape, and the code | symbol L has shown the full length of the diaper.

  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.

  The tape-type disposable diaper includes 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 F1 side portion of the abdominal side F, and a back side B. On both sides of the upper edge B1 side 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 constituting the outer surface of the product. 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.

The liquid-impermeable sheet is not limited by thickness or basis weight, but in normal cases, the thickness is preferably 10 to 200 μm, particularly preferably 20 to 50 μm, and the basis weight is 10 to 50 g / m ² , In particular, 15 to 30 g / m ² is desirable.

(Surface sheet)
The top sheet 30 is sufficient if it has liquid permeability, and for example, a porous or non-porous nonwoven fabric or a porous plastic sheet can be used. Of these, the nonwoven fabric is not particularly limited as to what the raw fiber is. For example, synthetic fibers such as olefins such as polyethylene and polypropylene, polyesters and polyamides, recycled fibers such as rayon and cupra, natural fibers such as cotton, and mixed fibers and composite fibers using two or more of them. Etc. can be illustrated. Furthermore, the nonwoven fabric may be manufactured by any processing. Examples of the processing method include known methods such as a spunlace method, a spunbond method, a thermal bond method, a melt blown method, a needle punch method, an air through method, and a point bond method. For example, the spun lace method is a preferable processing method for obtaining flexibility and drapeability, and the thermal bond method is for obtaining bulkiness and softness.

  Further, the top sheet 30 may be composed of one sheet or may be composed of a laminated sheet obtained by bonding two or more sheets. Similarly, 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 can be provided between the surface sheet 30 and the absorbent element 50 in order to move excrement that has passed through the surface sheet 30 to the absorber and prevent reversal. This intermediate sheet 40 not only improves the absorption performance of the absorbent by quickly transferring the excrement to the absorber, but also prevents the excretion of the absorbed excrement from reversing from the absorber, and the surface of the top sheet 30 has a good touch. To do. The intermediate sheet 40 can be omitted.

  As the intermediate sheet 40, the same material as that of the top sheet 30 can be used. The intermediate sheet 40 is preferably bonded to the top sheet 30. When heat embossing or ultrasonic welding is used for the bonding, the material of the intermediate sheet 40 preferably has a melting point similar to that of the top sheet 30. Further, considering the permeation of the solid content in the stool, the fineness of the fiber used for the intermediate sheet 40 is preferably 5.0 to 7.0 dtex, but the liquid residue in the top sheet 30 increases. On the other hand, when the fineness of the fiber used for the intermediate sheet 40 is 1.0 to 2.0 dtex, the liquid residue of the top sheet 30 is hardly generated, but the solid content of the stool is hardly transmitted. Therefore, it is preferable that the fiber of the nonwoven fabric used for the intermediate sheet 40 has a fineness of about 2.0 to 5.0 dtex.

  The intermediate sheet 40 in the illustrated form is arranged in the center shorter than the width of the absorbent element 50, but may be provided over the entire width. 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.

(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.

  If there is no SAP particle in the upper part, the lower part, and the middle part of the absorber 56, or if there is very little, it cannot be said that the "absorbed throughout the 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 instead 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, the thickness 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 fastening tape 13 may have a symmetrical 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 grip portion 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 12T 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 12T, when the hook portion is the hook material 13A, a target sheet 12T 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 nonwoven fabric so that the hook material engagement protrusions 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 12T 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 12T 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 it is too close, a gap is likely to occur between the back end of the diaper and the body surface due to the thickness and stiffness of the absorbent element 50, so that it is preferably 10 mm 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.

(Recess of liquid-impermeable sheet and bonding of liquid-impermeable sheet)
Characteristically, the liquid-impermeable sheet 11 has a large number of cup-shaped recesses 14 that are recessed from the front side to the back side as shown in FIG. The front surface (first surface) arranged in a large number at intervals and the back surface (second surface) in which the protruding portions of the recesses 14 are arranged at intervals are provided. Further, the packaging sheet 58 that forms the bottom surface of the absorbent element 50 is joined to the surface of the liquid-impermeable sheet 11 by a joining portion 81 and a portion other than the recessed portion 14 on the surface without being joined to the surface. The inside of the recess 14 is a space 83, and the inner surface of the exterior sheet 12 is not joined with the protruding portion of the recess 14 on the back surface of the liquid-impermeable sheet 11, but the bottom 14 b and the joint portion of the recess 14 on the back surface. A space 84 is formed between the protruding portions of the concave portion 14 on the back surface.

  The shape of the recess 14 can be determined as appropriate, but may be an appropriate shape such as a truncated cone shape, a truncated pyramid shape, or a spherical shape. Moreover, the arrangement | sequence of the recessed part 14 can be suitably defined, such as zigzag form and matrix form.

Moreover, although the dimension of the recessed part 14 can be determined suitably, it is preferable that a diameter (it means a major axis in the case of other than a circle) is 1-20 mm, especially 7-10 mm. The interval between the recesses 14 is preferably 1 to 20 mm, particularly 3 to 10 mm. Further, the number of the concave portions 14 per unit area is preferably 1,000 to 200,000 pieces / m ² , particularly preferably 8,000 to 20,000 pieces / m ² , and the concave portions 14 of the liquid-impermeable sheet 11 are preferable. It is desirable that the ratio of the area of the opening of the recess 14 to the area of the portion having the thickness is about 60 to 100%, particularly about 80 to 100%.

  An appropriate joining means can be used to form the joint portions 81 and 82, but a hot melt adhesive can be preferably used, and the application pattern thereof is solid, bead, curtain, summit, or spiral application. Can be appropriately selected and used.

  Thus, the liquid-impermeable sheet 11 is made into a sheet having a large number of recesses 14, and when the front and back surfaces are bonded to the absorbent element 50 and the exterior sheet 12, bonding is performed except for the inside of the recess 14 and the protruding portion of the recess 14. When the spaces in the concave portion 14 and the protruding portions of the concave portion 14 are spaces 83 and 84, the joint portion of the exterior sheet 12 is reduced without adding a new material, and the texture of the outer surface is made flexible. The liquid-impermeable sheet 11 itself becomes a cushion material by the presence of an air layer in the spaces 83 and 84 between the inner and protruding portions of the recess 14 and the cup-shaped recess 14 being crushed and restored in the thickness direction like a spring. As a result, cushioning increases.

  Moreover, since disposable diapers are folded at the time of manufacture and a large number of sheets are collected and stored in a packaging bag in a compressed state in the stacking direction, how thin the diaper is is very important. In the case of the present invention, the portion exhibiting cushioning properties, that is, the cup-shaped concave portion 14 of the liquid-impermeable sheet 11 can be crushed to the same thickness as the sheet thickness. The cup-shaped recess 14 is restored (not meant only for complete restoration) and exhibits cushioning properties.

  Moreover, in the case of this invention, since a large ventilation space is ensured on both the front and back sides of the liquid-impermeable sheet 11, the air permeability is excellent.

  Furthermore, in addition to this improvement in air permeability, both the contact area between the liquid-impermeable sheet 11 and the absorbent element 50 and the contact area between the liquid-impermeable sheet 11 and the exterior sheet 12 are reduced, and the liquid-absorbing impermeability is also reduced. Since the joining portion 81 between the permeable sheet 11 and the absorbent element 50 and the joining portion 82 between the liquid-impermeable sheet 11 and the exterior sheet 12 do not overlap, a moisture-permeable sheet is used as the liquid-impermeable sheet 11 and urination The feeling of humidity when the outer surface is touched later is significantly reduced.

  On the other hand, the cup-shaped recess 14 of the liquid-impermeable sheet 11 may be formed so as to be recessed from the back side to the front side as shown in FIG. 8, but if formed so as to be recessed from the front side to the back side as shown in FIG. On the front side (top sheet 30 side) of the permeable sheet 11, spaces 83 in the recesses 14 are scattered independently of each other by the number of the recesses 14, and on the back side (exterior sheet 12 side) of the liquid-impermeable sheet 11. Regardless of the number of recesses 14, the spaces 84 between the protruding portions of the recesses 14 are continuously formed. Therefore, urine that has reached the surface of the liquid-impermeable sheet 11, fibers spilled from the absorbent element 50, and superabsorbent polymer are captured in the recesses 14 on the surface of the liquid-impermeable sheet 11 to diffuse and move. Can be blocked. Moreover, the air permeability between the liquid-impermeable sheet 11 and the exterior sheet 12 is further improved, and the effect of reducing the above-described humidity feeling is further enhanced.

  Further, the bonding area on the back surface of the liquid-impermeable sheet 11 (total area of the bonding portion 82) is made larger than the bonding area on the surface of the liquid-impermeable sheet 11 (total area of the bonding portion 81) (for example, FIG. However, if the size, arrangement, etc. of the recesses 14 are configured so that the latter is smaller than the former, the shape of the recesses 14 can be firmly maintained, but the texture of the outer surface can be maintained. This is preferable because it becomes even more flexible.

  Moreover, as shown in FIG. 3, the superabsorbent polymer particles 90 (other absorbent materials such as pulp fiber aggregates may be used instead of or in combination with the superabsorbent polymer particles 90 are accommodated in the recesses 14. The amount of vapor that permeates the liquid-impermeable sheet 11 is reduced, and the urine that has reached the surface of the liquid-impermeable sheet 11 improves the resilience of the concave portion 14 because the cushion material is provided in the concave portion 14. Is preferable without being diffused, and the absorption performance of the absorbent element 50 can be supplemented. In this case, the amount of the absorbent material such as the superabsorbent polymer particles can be appropriately determined. However, in a normal case, it is desirable to set the volume of the cup-shaped recess 14 to about 10 to 50%.

  In the tape type disposable diaper as shown in the example, the cushioning property of the connecting portion of the fastening tape 13 in the ventral portion F is high, and if the deformation is easy, the fastening around the waist becomes easy to loosen or the fastening tape 13 There is a risk that the connection of the will be easily disconnected. Therefore, as shown in the illustrated example, the concave portion 14 is not formed in the liquid-impermeable sheet 11 at the connection portion of the fastening tape 13 in the ventral portion F (the portion having the target sheet 12T in the illustrated example). It is desirable that the permeable sheet 11 and the exterior sheet 12 are firmly joined in a state of continuous contact.

  The present invention can be used in any form, such as a pants-type disposable diaper and a pad-type disposable diaper, in addition to the tape-type disposable diaper as in the above example.

  DESCRIPTION OF SYMBOLS 11 ... Liquid impervious sheet, 12 ... Exterior sheet, 14 ... Recessed part, 14b ... Bottom part, 30 ... Surface sheet, 40 ... Intermediate sheet, 50 ... Absorbing element, 56 ... Absorber, 58 ... Packaging sheet, 60 ... Side part Barrier cuffs, 62... Barrier sheet, 70... Back elastic sheet, 12T... Target sheet, 81 and 82.

Claims (5)

A liquid-permeable top sheet that forms the body-side surface; a liquid-impermeable sheet; and an absorbent element that absorbs and holds excrement disposed between the liquid-permeable top sheet and the liquid-impermeable sheet; In a disposable diaper provided with an exterior sheet made of a nonwoven fabric bonded to the back surface of a liquid-impermeable sheet with a hot melt adhesive,
The liquid-impermeable sheet has a plurality of cup-shaped recesses that are recessed from either the front or the back to the other, with a large number of the recesses being arranged at intervals, whereby the first surface has a large number of openings of the recesses arranged at intervals. The projecting portion of the recess has a second surface arranged in a large number at intervals,
Of the exterior sheet and the absorbent element, the one in contact with the first surface of the liquid-impermeable sheet is joined to a portion other than the concave portion of the first surface without being joined to the concave portion of the first surface, The recess in the first surface is a space,
Of the exterior sheet and the absorbent element, the one in contact with the second surface of the liquid-impermeable sheet is not joined with the protruding portion of the recess of the second surface, and the bottom of the recess of the second surface Joined and the space between the protrusions of the recesses on the second surface is a space,
A disposable diaper characterized by that.   The disposable diaper according to claim 1, wherein the concave portion of the liquid-impermeable sheet has a cup shape that is recessed from the front side to the back side.   The disposable diaper according to claim 2, wherein a bonding area of the second surface of the liquid-impermeable sheet is smaller than a bonding area of the first surface of the liquid-impermeable sheet.   The disposable diaper according to claim 2 or 3, wherein at least one of a fiber assembly and a superabsorbent polymer particle is accommodated in the recess. It is a tape-type disposable diaper that is worn by connecting the fastening tape provided on both sides of the dorsal part to the outer surface of the ventral part,
In the connection part of the fastening tape in the ventral part, no recess is formed in the liquid-impermeable sheet, and the liquid-impermeable sheet and the exterior sheet are joined in a continuous contact state. The disposable diaper according to any one of claims 1 to 4.

Images