JP2012070914A - Absorbent article and method for manufacturing the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an absorbent article which hardly impairs the flexibility of an absorbent body although the front surface has a large number of satisfactorily cushionable protrusions; and to provide a method for manufacturing the same.SOLUTION: The absorbent article is characterized in that external protrusions 31 each having a recessed rear surface and a protruding front surface are arranged at intervals on the front surface side element consisting of a top sheet 30 and an intermediate sheet 40, internal protrusions 51 each having a recessed rear surface and a protruding front surface are formed at positions corresponding to the external protrusions 31, respectively, on the absorbent element 50 formed by enclosing the absorbent body 56 with an enclosing sheet 58, the internal protrusions 51 enters the recess of the rear surfaces of the external protrusions 31 respectively, and the density of each of the internal protrusions 51 is 1 to 3.5 times the density of the part which does not have internal protrusions 51 in the absorbent element 50.

Description

  The present invention relates to absorbent articles such as disposable diapers and sanitary napkins, and a method for producing the same.

In general, an absorbent article has a basic structure in which an absorbent is interposed between a liquid-permeable top sheet that forms a body-side surface and a liquid-impermeable sheet that is positioned on the outer surface side, and excrement Passes through the top sheet and is absorbed and held by the absorber.
In such an absorbent article, in order to reduce the contact area between the surface and the skin, improve air permeability, prevent reversion, and the like, it is known to form a large number of irregularities on the surface (for example, patents) References 1 and 2). As a method for forming irregularities, embossing is performed by passing between the embossing roll (top sheet side) and the anvil roll (absorbing body side) with the top sheet placed on the absorbent body. A method is widely used in which a large number of recesses are formed and portions other than the recesses are projections. According to this method, since the protrusion includes the absorbent body, the top sheet and the absorbent body are well integrated with each other, such as having an advantage of having cushioning properties (compression recovery) while having a certain degree of rigidity. There is an advantage that the top sheet can be prevented from floating from the absorber side.
However, in this prior art, not only the absorber is strongly compressed and hardened in the recess, but also the recess has to be provided more than the number of protrusions (three or more around the protrusions). There was a problem that the body became stiff.

JP 2010-142460 A JP 2010-142461 A

  Then, the main subject of this invention is providing the absorptive article which does not impair the softness | flexibility of an absorber, and its manufacturing method, although it has many protrusion parts which are rich in cushioning properties on the surface.

The present invention that has solved the above problems is as follows.
<Invention of Claim 1>
In an absorbent article comprising an absorbent element, a liquid-permeable surface-side element that covers the surface side of the absorbent element, and a liquid-impermeable sheet that covers the back side of the absorbent element,
A plurality of outer protrusions having a shape in which the back surface is recessed and the surface protrudes are arranged at intervals on the surface side element,
Inner protrusions each having a shape in which the back surface is recessed and the surface protrudes are formed at positions corresponding to the outer protrusions in the absorbent element, and the inner protrusions enter into the recesses on the back surface of the outer protrusions. And
The density of the inner protrusions is 1 to 3.5 times the density of the portion having no inner protrusion in the absorbent element.
An absorbent article characterized by the above.

(Function and effect)
In the present invention, since the inner protrusion in the absorbent element enters the recess on the back surface of the outer protrusion in the front element, and the outer protrusion is supported by the inner protrusion, the front element and the absorption are obtained. The elements are well integrated with each other, and the outer protrusions in contact with the body have a certain degree of rigidity and cushioning properties. Moreover, in the present invention, the shape of the outer protrusion and the inner protrusion is a shape in which the back surface is recessed and the front surface protrudes, and the density of the inner protrusion is 1 to 1 of the density of the portion having no inner protrusion in the absorbent element. Since it is 3.5 times (that is, it is not compressed to the extent that it is hardened as a material), the flexibility of the absorbent body is not impaired by the formation of the inner protrusions.

<Invention of Claim 2>
The number of the outer protrusions is 60 to 10000, the planar projection area of the protruding portion on the front surface side is 0.005 to 0.05 m ² , the protruding height on the front surface side is 0.5 to ³ mm, and the recess on the back surface The depth is 0.5 to 3 mm, the center interval in the longitudinal direction is 1 to 20 mm, and the center interval in the width direction is 1 to 20 mm.
The number of the inner protrusions is 60 to 10,000, the planar projection area of the protruding portion on the front surface side is 0.005 to 0.05 mm ² , the protruding height on the front surface side is 0.03 to 3 mm, and the depth of the recess on the back surface 0.03 to 3 mm, the center distance in the longitudinal direction is 1 to 20 mm, and the center distance in the width direction is 1 to 20 mm.
The absorbent article according to claim 1.

(Function and effect)
The number of outer protrusions and inner protrusions of the present invention can be determined as appropriate, but is preferably within these ranges.

<Invention of Claim 3>
The major axis on the surface side of the inner projection is 0.6 to 0.9 times the minor axis of the recess on the back surface of the outer projection,
The protrusion height on the surface side of the inner protrusion is 0.6 to 1.0 times the depth of the recess on the back surface of the outer protrusion,
The absorbent article according to claim 1 or 2.

(Function and effect)
As will be described later, the absorbent article of the present invention can be manufactured by a method in which a surface-side element having an outer protrusion and an absorbent element having an inner protrusion are separately manufactured, and then both are bonded together. This manufacturing method has the advantage that it only needs to add an outer and inner protrusion forming step by embossing to existing equipment. In this case, when the surface-side element having the outer protrusion and the absorbent element having the inner protrusion are bonded together, positioning is necessary in order for the inner protrusion to enter the recess on the back surface of the side protrusion. As described above, the major axis on the front side of the inner projection is 0.6 to 0.9 times the minor axis of the recess on the rear side of the outer projection, and the projection height on the front side of the inner projection is When the depth of the recess on the back surface of the protrusion is 0.6 to 1.0 times, the alignment between the front surface side element and the absorbing element is facilitated. Further, in this case, since the inner protrusion is not excessively small, the support function of the outer protrusion is sufficiently exhibited.

<Invention of Claim 4>
The surface side element comprises a top sheet that forms a body side surface, and an intermediate sheet integrated with the absorbent element side surface of the top sheet,
The absorbent element comprises an absorbent body and a packaging sheet for packaging the absorbent body.
The absorptive article according to any one of claims 1 to 3.

(Function and effect)
The present invention can be easily applied to absorbent articles having such a general structure without changing the laminated structure.

<Invention of Claim 5>
It is a disposable diaper, and has a projection region in which a large number of the outer projections and inner projections are formed at the front end portion, the rear end portion, and an intermediate portion therebetween, and the width of the projection region at the intermediate portion. Is narrower than the width of the protrusion region at the front end portion and the rear end portion,
The absorbent article of any one of Claims 1-4.

(Function and effect)
Thus, when applied to a disposable diaper, the width of the protrusion region in the intermediate portion of the front end portion, the rear end portion and the intermediate portion between them is set to the width of the protrusion region in the front end portion and the rear end portion. By making it narrower than the width, it is possible to reduce the uncomfortable feeling that the projections contact the inner thigh.

<Invention of Claim 6>
The absorbent article according to any one of claims 1 to 5, which is a disposable diaper and does not have the outer protrusion and the inner protrusion in a crotch portion.

(Function and effect)
Since the absorption element having a certain degree of rigidity has a three-dimensional shape, the part having the outer protrusion part and the inner protrusion part is less likely to be deformed than the part not having the outer protrusion part and the inner protrusion part. Therefore, as described above, when applied to a disposable diaper, the diaper is deformed so that the crotch part is relatively flexible and can be easily mounted without providing the outer protrusion part and the inner protrusion part on the crotch part. In addition, it is preferable that the followability with respect to the movement of the leg after wearing is good.

<Invention of Claim 7>
Bonding the intermediate sheet to the absorbent element side surface of the top sheet forming the body side surface to form the surface side element;
An outer protrusion forming step for forming a large number of outer protrusions in a shape in which the back surface is recessed and the surface protrudes by embossing with respect to the surface side element,
Wrapping the absorbent body with a packaging sheet to form an absorbent element;
An inner protrusion having a shape in which the back surface is recessed and the surface protrudes by embossing at a position corresponding to the outer protrusion in the absorbent element, and the density is 1 to 3.5 times that of the non-projection. Forming an inner protrusion, respectively,
Including a bonding step of bonding the surface-side element formed with the outer protrusion and the absorbent element formed with the inner protrusion so that the inner protrusion enters the recess on the back surface of the outer protrusion.
The manufacturing method of the absorbent article characterized by the above-mentioned.

(Function and effect)
Thus, after manufacturing separately the surface side element which has an outside projection part, and the absorption element which has an inside projection part, manufacturing the absorptive article of the present invention which has the above-mentioned feature by the method of pasting both together Can do. Moreover, this manufacturing method has the advantage that it is only necessary to add an outer and inner protrusion forming step by embossing to existing equipment.

  As described above, according to the present invention, there are advantages such as that the flexibility of the absorbent body is not impaired while having a large number of cushioning portions on the surface.

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 expanded sectional view. It is a photograph which shows the surface of an absorption element. It is a photograph which shows the back surface of an absorption element. It is a photograph which shows the inner surface of a sample disposable diaper. 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 inner surface of a tape type disposable diaper. It is sectional drawing corresponded in the 6-6 line | wire cross section of FIG. 1 in another form. It is a flowchart which shows the principal part of manufacturing equipment.

  Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings. 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. "Up and down direction" means the wearing state of the diaper, that is, the direction perpendicular to the width direction when the diaper is folded in two at the crotch so that the abdomen and dorsal parts of the diaper are overlapped Means.

  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 portion that extends from the lower abdomen along the center in the width direction through the crotch to cover the buttocks, and a liquid-permeable top 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 slightly larger dimensions 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.

(Top sheet)
The top sheet 30 constitutes a liquid-permeable surface-side element that covers the surface side of the absorbent element. As the top sheet 30, a liquid-permeable material is sufficient, 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.

  The top sheet 30 may be composed of a single sheet or 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 top sheet 30 and the absorbent element 50 in order to move excrement that has passed through the top sheet 30 to the absorbent body and prevent reversal. This intermediate sheet 40 not only improves the absorption performance by the absorber by quickly transferring the excrement to the absorber, but also prevents the excretion of the absorbed excrement from returning from the absorber, making the top sheet 30 surface feel better To do. The intermediate sheet 40 may be omitted. In this case, only the top sheet 30 constitutes a liquid-permeable surface side element that covers the surface side of the absorbent element 50.

  As the intermediate sheet 40, the same material as 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 the same melting point as 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 hardly occurs, but the solid content of the stool is difficult to permeate. 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)
In order to prevent urine and soft stool that move laterally on the top sheet 30 and prevent lateral leakage, side barrier cuffs 60, 60 that protrude (stand up) on the use surface side are provided on both sides of the product. 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 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 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 .

  Although this packaging sheet 58 is not shown, only the upper surface and side surfaces of the absorbent body 56 are covered with crepe paper or 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 coated with crepe paper or nonwoven fabric. And the side and lower surfaces may be covered with a liquid-impermeable sheet such as polyethylene (each of these materials becomes 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, for example, a substantially tape shape 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 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 tangled. 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 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 elastic member 72 such as a perforated sheet, net, or elongated (thread-like or string-like) is fixed between the two sheet base materials 71 while being stretched along the width direction. Used. As the sheet base 71 in this case, the same one as the exterior sheet 12 can be used. The elastic stretch member 72 preferably has an elongation rate (when the free length is 100%) 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. In this case, the back-side elastic sheet 70 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.

(Outer protrusion and inner protrusion)
Characteristically, a large number of outer protrusions 31 having a shape in which the back surface is recessed and the front surface protrudes are arranged at intervals on the front surface elements 30 and 40, and positions corresponding to the outer protrusions 31 in the absorbent element 50. Further, an inner protrusion 51 having a shape in which the back surface is recessed and the front surface protrudes is formed, and the inner protrusion 51 enters into the recess on the back surface of the outer protrusion 31. In the illustrated example, the liquid-impermeable sheet 11 is not formed with irregularities, but a projection that enters the recess on the back surface of the inner projection 51 can also be provided.

  As the shape of the outer protrusion 31, for example, an appropriate shape such as a truncated pyramid shape, a prismatic shape, a cylindrical shape, or an elliptical column shape can be adopted in addition to a spherical shape as shown in the illustrated example. The shape of the inner protrusion 51 can be selected from the same shape, and as long as it can enter the recess on the back surface of the outer protrusion 31, the inner protrusion 51 is similar to the recess shape on the back surface of the outer protrusion 31, and has a different shape. It is also possible to do.

The number of the outer protrusions 31 and the inner protrusions 51, the planar projection area, the protrusion height on the front surface side, the depth of the recesses on the back surface, the center interval in the longitudinal direction, and the center interval in the width direction can be appropriately determined. For example, it is preferable to be within the following range.
[Outside protrusion 31]
Number (per article): 60 to 10,000 pieces Planar projection area of the protruding portion on the surface side: 0.005 to 0.05 m ²
Surface side protrusion height 31h: 0.5-3 mm
Depth 31d on the back side: 0.5-3mm
Center distance 31y in the longitudinal direction: 1 to 20 mm
Center distance 31x in the width direction: 1 to 20 mm
Top thickness 31t: 0.1 to 1 mm
[Inner protrusion 51]
Number (per article): 60 to 10,000 pieces Planar projection area of the protruding portion on the surface side: 0.005 to 0.05 m ²
Surface side protrusion height 51h: 0.03 to 3 mm
Recess depth 51d: 0.03 to 3 mm
Center distance 51y in the longitudinal direction: 1 to 20 mm
Center distance 51x in the width direction: 1 to 20 mm
Top thickness 51t: 1 to 5 mm
As shown in FIG. 7A, it is preferable that the inner protrusion 51 has a shape and size that fits in the recess on the back surface of the outer protrusion 31 because the liquid permeability in the thickness direction is excellent. In the case where the surface side elements 30 and 40 having the outer protrusions 31 and the absorbent element 50 having the inner protrusions 51 are separately manufactured and then a manufacturing method in which both are bonded is employed, the surface side elements 30 and 40 are used. It may be difficult to position the absorbent element 50. Therefore, in order to facilitate the alignment between the surface-side elements 30 and 40 and the absorbing element 50, as shown in FIG. The minor axis of the recess on the back surface (diameter in the case of a circle diameter) is 0.6 to 0.9 times SD, and the protrusion height 51 h on the front side of the inner protrusion 51 is the depth of the recess on the back surface of the outer protrusion 31. It is also a preferable form to make it 0.6 to 1.0 times the thickness 31d. Even in this form, the inner protrusion 51 is not excessively small, and thus the support function of the outer protrusion 31 described later is sufficiently exhibited.

  The protrusion region in which the outer protrusion 31 and the inner protrusion 51 are formed may have a constant width with respect to the diaper and continuously extend in the front-rear direction. Since the absorbing element 50 having a certain degree of rigidity has a three-dimensional shape, the portion having the protrusion is less likely to be deformed than the portion not having the outer protrusion 31 and the inner protrusion 51, and the protrusion region is the inner portion. Since excessive contact with the thigh may cause discomfort, as shown in FIG. 11 (a), among the front end portion, the rear end portion, and the intermediate portion between them, the protruding portion in the intermediate portion It is also preferable to make the width of the region 82 narrower than the widths of the protrusion regions 81 and 83 at the front end portion and the rear end portion.

  In addition, the portion having the outer protrusion 31 and the inner protrusion 51 has a three-dimensional shape of the absorbing element 50 having a certain degree of rigidity, so that the portion having the outer protrusion 31 and the inner protrusion 51 is not compared. If it is provided in the crotch part, there is a risk that the diaper will be easily deformed and the followability to the movement of the leg after mounting may be impaired. Therefore, as shown in FIG. 11 (b), the crotch portion is not provided with the outer protrusion 31 and the inner protrusion 51, and the protrusion regions 84 and 85 are provided discontinuously on the front and rear sides thereof to facilitate mounting. The form which made favorable the followable | trackability with respect to the deformation | transformation of a diaper which makes it and the movement of the leg after mounting | wearing is also preferable.

  On the contrary, the crotch portion is provided with a projection region 86 in the crotch portion as shown in FIG. 12 to prevent the surface side elements 30 and 40 from floating easily from the absorbent element 50 when wet by excrement. It is also possible to adopt a structure in which no protrusion region is provided on both the front and rear sides.

On the other hand, the portion having the inner protrusion 51 in the absorbent element 50 is hardened to some extent, which affects the touch on the outer surface of the article. Therefore, in order to eliminate this, as shown in FIG. 13, a non-woven fabric 52 is interposed between the absorbent element 50 and the liquid-impermeable sheet 11 so as to cover the inner protrusion 51 of the absorbent element 50. This is a preferred form. As the nonwoven fabric 52 in this case, various nonwoven fabrics having a basis weight of about 10 to 50 g / m ² , a thickness of about 0.1 to 1 mm, and a fineness of constituent fibers of about 2.0 to 5.0 dtex, particularly spunbond nonwoven fabric and air-through nonwoven fabric. It can be used suitably.

  Further characteristically, the density of the inner protrusions 51 in the absorbent element 50 is 1 to 3.5 times, more preferably 1 to 2 times, and particularly preferably 1 to 1 times the density of the portion not having the inner protrusions 51. .7 times. The density of the inner protrusions 51 is the amount of deformation in the thickness direction of the inner protrusions 51 when the inner protrusions 51 are formed by embossing or the like. It can adjust suitably by changing with the separation distance with the bottom part of the recessed part of a roll.

  The following advantages are brought about by having the structure described above. That is, the inner protrusion 51 of the absorbent element 50 enters the recess on the back surface of the outer protrusion 31 of the front surface elements 30 and 40, and the outer protrusion 31 is supported by the inner protrusion 51. The surface-side elements 30 and 40 and the absorbent element 50 are well integrated, and the outer protrusion 31 in contact with the body has a certain degree of rigidity and a cushioning property. In addition, the outer protrusion 31 and the inner protrusion 51 have a shape in which the back surface is recessed and the front surface protrudes, and the compression amount of the bottom of the recess on the back surface of the inner protrusion 51 is small or absent. Flexibility is not impaired by the formation of the inner protrusion 51.

(Production method)
FIG. 14 shows an example of a method for manufacturing a disposable diaper having the above-described outer protrusion 31 and inner protrusion 51. In this method, after the intermediate sheet 40 is bonded to the back surface of the top sheet 30 that forms the body-side surface with a hot melt adhesive or the like in the production line for the surface-side elements 30 and 40, the intermediate sheet 40 is passed through the embossing roll 101. A large number of outer protrusions 31 having a shape that is recessed and the surface protrudes are formed at intervals, and the surface-side elements 30 and 40 are manufactured. Such an outer protrusion 31 includes, as an embossing roll 101, a convex roll 101a in which convex portions having a shape corresponding to the recesses on the back surface of the inner protrusion 51 are formed on the outer peripheral surface with a large number of intervals, and the convex roll 101a. It can form by using the concave roll 101b in which the recessed part which each convex part of 101a enters is formed in the outer peripheral surface, and passing the surface side elements 30 and 40 between the convex roll 101a and the concave roll 101b. At this time, the interval between the convex roll 101a and the concave roll 101b is set such that the convex portion of the convex roll 101a has a certain gap, particularly preferably 1/3 to 1 times the thickness of the surface-side elements 30, 40, more preferably 1. When set so as to enter the concave portion of the concave roll 101b with a gap of about / 2 to 1 time, particularly preferably about 3/5 to 1 time (that is, the convex portion does not contact the concave portion), the surface side elements 30 and 40 become hard. It is preferable because it is difficult. As the concave roll 101b, a steel roll or rubber roll having a net-like body stretched on the outer peripheral surface can be suitably used.

  On the other hand, in the absorbent element 50 production line, pulp and superabsorbent polymer are supplied to the pulp stacking drum 102 to form an absorbent body 56, and the absorbent body 56 is transferred onto a separately supplied packaging sheet 58, and a nip roll After the absorbent body 56 is pressurized together with the packaging sheet 58 by 103, both sides in the CD direction of the packaging sheet 58 are folded onto the absorbent body 56 by the sailor 104 to cover the absorbent body 56, and then passed through the embossing roll 105. In the absorbent element 50, the inner protrusion 51 is located at a position where the back surface is recessed and the front surface protrudes, and the density is 1 to 3.5 times that of the non-projection (more preferably 1 to 2 times). , Particularly preferably 1 to 1.7 times), and after this embossing, it is cut with a cutting roll 106 at intervals in the MD direction, By personalizing 50, to produce the absorbent element 50. A sample of this absorbent element 50 is shown in FIG. 8 (front side) and FIG. 9 (back side).

  Such an inner protrusion 51 includes, as an embossing roll 105, a convex roll 105a in which convex portions having a shape corresponding to the recesses on the back surface of the inner protrusion 51 are formed on the outer peripheral surface with a large number of intervals, and the convex roll 105a. The concave roll 105b in which a concave portion into which each convex portion of 105a enters is formed on the outer peripheral surface, and the interval between the convex roll 105a and the concave roll 105b, the convex portion of the convex roll 105a is a certain gap, particularly preferably the surface It enters into the concave portion of the concave roll 105b with a gap of about 1/3 to 1 times, more preferably 1/2 to 1 time, particularly preferably 3/5 to 1 times the thickness of the side elements 30 and 40 (that is, the convex portion is It can be formed by passing the surface-side elements 30 and 40 between the convex roll 105a and the concave roll 105b. At that time, the convex roll 105a and the concave roll 105b are formed. Intervals and at least one pressure By setting appropriately, it is possible to adjust the density of the inner projection 51 in the above range. As the concave roll 105b, as in the case of the outer protrusion 31, a steel roll or rubber roll with a net-like body stretched on the outer peripheral surface can be suitably used.

  In the embossing of the surface side element 30 and 40 production line and the absorption element 50 production line, it is preferable to use embossing with heating in order to improve the shape maintaining property of the outer and inner protrusions 31 and 51. In this case, the surface-side elements 30 and 40 (top sheet, intermediate sheet) are preferably hydrophilic non-woven fabric made of thermoplastic fibers, and the absorbent element 50 packaging sheet is also hydrophilic made of thermoplastic fibers instead of crepe paper. Nonwoven fabric is preferred.

  Next, the absorbent element 50 manufactured in the absorbent element 50 manufacturing line is supplied to the surface side elements 30 and 40 manufactured in the front side element 30 and 40 manufacturing line, and both are bonded to the outside by the laminating roll 107. The inner protrusion 51 is fitted into the recess on the back surface of the protrusion 31 and bonded with a hot melt adhesive or the like. Thereafter, in the same manner as in a known method, for example, an exterior sheet in which a target sheet and a liquid-impermeable sheet are attached with a hot melt adhesive or the like in an exterior sheet production line is manufactured, and the surface-side elements 30 and 40 are formed thereon. A disposable diaper is manufactured by attaching a backside element with a hot melt adhesive or the like, and further attaching a solid gather and fastening tape manufactured separately with a solid gather production line to both sides of the inner surface with a hot melt adhesive or the like (Not shown).

  Thus, after manufacturing the surface side elements 30 and 40 which have the outer side protrusion part 31, and the absorption element 50 which has the inner side protrusion part 51 separately, the disposable diaper which has the above-mentioned characteristic is manufactured by the method of bonding both together. can do. Moreover, this manufacturing method has the advantage that it is only necessary to add the outer and inner protrusions 31 and 51 forming step by embossing to the existing equipment.

  INDUSTRIAL APPLICABILITY The present invention can be used for absorbent articles in general, such as a tape-type disposable diaper as described above, a pants-type disposable diaper, a pad-type disposable diaper, and a sanitary napkin.

  DESCRIPTION OF SYMBOLS 11 ... Liquid impervious sheet, 12 ... Exterior sheet, 30 ... Top sheet, 31 ... Outer protrusion, 40 ... Intermediate sheet, 50 ... Absorbing element, 51 ... Inner protrusion, 56 ... Absorber, 58 ... Packaging sheet, 60 ... side barrier cuffs, 62 ... barrier sheet, 70 ... back elastic sheet, 74 ... target sheet.

Claims (7)

In an absorbent article comprising an absorbent element, a liquid-permeable surface-side element that covers the surface side of the absorbent element, and a liquid-impermeable sheet that covers the back side of the absorbent element,
A plurality of outer protrusions having a shape in which the back surface is recessed and the surface protrudes are arranged at intervals on the surface side element,
Inner protrusions each having a shape in which the back surface is recessed and the surface protrudes are formed at positions corresponding to the outer protrusions in the absorbent element, and the inner protrusions enter into the recesses on the back surface of the outer protrusions. And
The density of the inner protrusions is 1 to 3.5 times the density of the portion having no inner protrusion in the absorbent element.
An absorbent article characterized by the above. The number of the outer protrusions is 60 to 10,000, the planar projection area of the protruding portion on the front surface side is 0.005 to 0.05 m ² , the protruding height on the front surface side is 0.5 to ³ mm, and the depth of the recess on the back surface 0.5 to 3 mm, the center distance in the longitudinal direction is 1 to 20 mm, and the center distance in the width direction is 1 to 20 mm,
The number of the inner protrusions is 60 to 10,000, the planar projection area of the protruding portion on the front surface side is 0.005 to 0.05 mm ² , the protruding height on the front surface side is 0.03 to 3 mm, and the depth of the recess on the back surface 0.03 to 3 mm, the center distance in the longitudinal direction is 1 to 20 mm, and the center distance in the width direction is 1 to 20 mm.
The absorbent article according to claim 1. The major axis on the surface side of the inner projection is 0.6 to 0.9 times the minor axis of the recess on the back surface of the outer projection,
The protrusion height on the surface side of the inner protrusion is 0.6 to 1.0 times the depth of the recess on the back surface of the outer protrusion,
The absorbent article according to claim 1 or 2. The surface side element comprises a top sheet that forms a body side surface, and an intermediate sheet integrated with the absorbent element side surface of the top sheet,
The absorbent element comprises an absorbent body and a packaging sheet for packaging the absorbent body.
The absorptive article according to any one of claims 1 to 3. It is a disposable diaper, and has a projection region in which a large number of the outer projections and inner projections are formed at the front end portion, the rear end portion, and an intermediate portion therebetween, and the width of the projection region at the intermediate portion. Is narrower than the width of the protrusion region at the front end portion and the rear end portion,
The absorbent article of any one of Claims 1-4.   The absorbent article according to any one of claims 1 to 5, which is a disposable diaper and does not have the outer protrusion and the inner protrusion in a crotch portion. Bonding the intermediate sheet to the absorbent element side surface of the top sheet forming the body side surface to form the surface side element;
An outer protrusion forming step for forming a large number of outer protrusions in a shape in which the back surface is recessed and the surface protrudes by embossing with respect to the surface side element,
Wrapping the absorbent body with a packaging sheet to form an absorbent element;
An inner protrusion having a shape in which the back surface is recessed and the surface protrudes by embossing at a position corresponding to the outer protrusion in the absorbent element, and the density is 1 to 3.5 times that of the non-projection. Forming an inner protrusion, respectively,
Including a bonding step of bonding the surface-side element formed with the outer protrusion and the absorbent element formed with the inner protrusion so that the inner protrusion enters the recess on the back surface of the outer protrusion.
The manufacturing method of the absorbent article characterized by the above-mentioned.