JP5587004B2 - Disposable absorbent article and method for producing disposable absorbent article - Google Patents

Description

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

The surface sheet of disposable diapers and disposable absorbent pads has the characteristic of preventing discomfort and rash caused by redeposition of excrement such as urine on the skin. Various characteristics such as a characteristic to prevent are required. Examples of such a surface sheet include those obtained by providing irregularities on the skin-side surface as shown in Patent Documents 1 and 2 and reducing the contact area of the skin.
Patent Document 1 discloses a configuration that ensures the air permeability of the topsheet by defining the amount of air permeation in the horizontal direction of the topsheet with unevenness on the skin side surface. Moreover, the surface sheet of the absorbent article described in Patent Document 2 has a convexity that quickly moves moisture from the convex portion to the concave portion by touching the wearer's skin by making the fiber density of the concave portion higher than that of the convex portion. The structure is such that the liquid does not easily remain in the part.

Japanese Patent No. 3587831 Japanese Patent No. 3611838

However, when the fiber density of the concave portion of the surface sheet is increased as described in Patent Document 2, if the number of the concave portions is increased and the skin contact area is reduced, the flexibility of the surface sheet is lost, and the touch becomes worse. If the number of recesses is reduced, the skin contact area cannot be reduced sufficiently.
Then, the main subject of this invention is to make compatible the softness | flexibility of a surface sheet, and the adhesion prevention of excrement to the skin.

The present invention that has solved the above problems is as follows.
<Invention of Claim 1>
In a disposable absorbent article comprising a liquid-permeable surface sheet, a liquid-impermeable sheet, and an absorbent body interposed therebetween,
The surface sheet has a plurality of concave portions formed on the skin contact side surface at predetermined intervals in the front-rear direction and the width direction, and a cross section along the width direction has a wave shape having a plurality of wave crest portions and wave bottom portions, and its crest portions and the wave trough portions are formed so as to be continuous in the longitudinal direction, the fiber basis weight consists of non-woven fabric 10 to 40 g / m ^2,
The bottom of the recess has a fiber density higher than the surroundings, the thickness of the bottom of the recess is 10 to 50% of the thickness of the portion other than the recess, and at least a part of the plurality of recesses is located at the wave bottom. and it is,
The interval in the width direction between the wave crests is narrower than the interval between the recesses formed on the top sheet,
A disposable absorbent article characterized by that.

(Function and effect)
In the corrugated surface sheet having such a recess, excrement moves from the wave crest to the wave bottom due to the height difference, and moves in the front-rear direction along the valley between the wave crests, and is located at the wave bottom. In the process, the liquid content of excrement (solid content smaller than the liquid content and the interstices between the fibers) moves toward the absorber, and a part of the solid content remains on the surface. Under the present circumstances, since the surface area of the surface sheet of this invention is remarkably larger than an apparent area (plane projection area) by adoption of a wave-like cross section, the liquid content of excrement is taken in in a surface sheet quickly. Further, the liquid content of excrement held in the top sheet is gathered from the portion other than the concave portion (hereinafter referred to as the convex portion) to the concave portion and the periphery thereof due to the difference in fiber density between the bottom portion of the concave portion and the periphery thereof. Become.

  In such an absorption form, when absorbing a liquid-solid mixture having fluidity such as watery feces of infants, not only can the leakage prevention effect be improved by quickly depriving the fluidity of excrement, but also the surface sheet The liquid content of the excrement remaining inside is retained at or near the bottom of the recess, and most of the solid content remaining on the surface is retained in the valleys or recesses between the crests, both of which are prevented from adhering to the skin. The Of course, the risk of lateral leakage due to movement of the excrement in the width direction can also be reduced.

  In addition, the concave portion of the topsheet is not excessively dense as apparent from the above-mentioned basis weight range and thickness range as compared with the conventional example formed simply by heat embossing, so that flexibility and texture are hardly impaired. Absent. Especially for the flexibility, the cushioning property is improved (being easily deformed) due to the wavy surface sheet, and the contact area with the skin is reduced. In terms of sensuality, it will exhibit significantly superior flexibility.

  As described above, the present invention is different from the basic idea in that the excrement that cannot be held at the bottom of the recesses may be attached to the skin simply by increasing the number of the recesses, and it is not excessive but sufficiently dense. By combining the high-concave portion and the wave-like cross-sectional structure, both the flexibility of the surface sheet and the prevention of excrement on the skin are achieved at a high level, and the absorption performance is also improved.

  In the present invention, the concave portion and the convex portion of the surface sheet indicate irregularities viewed from the skin contact side, and the “wavy” in the present invention is not only a wave shape by a curve, but also a rectangular wave, Including triangular waves.

<Invention of Claim 2>
In a disposable absorbent article comprising a liquid-permeable surface sheet, a liquid-impermeable sheet, and an absorbent body interposed therebetween,
After the surface sheet is formed with a large number of recesses on the skin contact side surface at predetermined intervals in the front-rear direction and the width direction, the roll surface is passed through a nip roll that is corrugated in the width direction, and the width direction The cross section along the line is a wave having a large number of wave crests and wave bottoms, and the wave crest and wave bottoms are made of a nonwoven fabric formed so as to be continuous in the front-rear direction,
Bottom of the recess has a high fiber density than the surrounding, and at least some of said plurality of depressions are located in the wave bottom,
The interval in the width direction between the wave crests is narrower than the interval between the recesses formed on the top sheet,
A disposable absorbent article characterized by that.

(Function and effect)
In the present invention, after the concave portion is provided on the skin contact surface of the nonwoven fabric forming the surface sheet, the nonwoven fabric is passed through a nip roll (hereinafter referred to as “wave roll”) in which the roll surface is corrugated in the width direction, A corrugation in the width direction is formed on the surface. By forming it by wave roll processing after forming the recess, it becomes possible to soften the portion where the rigidity is increased when forming the recess.
The “width direction” of the roll referred to in the present invention refers to a direction perpendicular to the running direction of the roll.

<Invention of Claim 3>
The disposable absorbent article according to claim 1 or 2, wherein the concave portion is formed by a large number of dot-shaped heat embosses or a lattice-shaped heat emboss made of a large number of straight lines.

(Function and effect)
By forming the recesses in the shape of a large number of dots or lattices, the projections are stably formed between the recesses and are not easily crushed.

<Invention of Claim 4>
The disposable absorbent article according to claim 3, wherein an interval in the width direction between the wave crests is narrower than a dot interval or a lattice interval of recesses formed on the surface sheet.

(Function and effect)
By setting the interval between the flanges formed by the wave rolls to be greater than the interval between the recesses, the probability that the position of the recesses overlaps with the flanges increases.

  <Invention of Claim 5>

Having an intermediate sheet interposed between the top sheet and the absorber,
3. The disposable absorbent article according to claim 2, wherein the top sheet is overlapped with the intermediate sheet, the concave portion is formed on the skin contact surface side, and the top sheet is passed through the nip roll together with the intermediate sheet.

(Function and effect)
As in the present invention, when the top sheet and the intermediate sheet are integrally rolled, the adhesion between the two sheets is increased, and the excrement is transferred more quickly from the top sheet to the intermediate sheet.

<Invention of Claim 6>
The disposable absorbent article according to claim 5, wherein the intermediate sheet is a nonwoven fabric having a higher water absorption than the top sheet.

(Function and effect)
Thus, if the intermediate sheet has a higher water absorption than the top sheet, the excrement easily moves from the bottom of the recess or the back surface around the intermediate sheet to the intermediate sheet joined to the bottom of the recess, and the absorption rate is further increased. Can be improved. The “water absorption” in the present invention indicates the water absorption measured by the JIS L 1907 birec method.

<Invention of Claim 7>
The non-woven fabric of the top sheet is an air-through non-woven fabric having a fineness of raw material fibers of 1.0 to 3.0 dtex, a thickness of 0.1 to 5.0 mm, and a basis weight of 10 to 40 g / m ² .
The disposable absorbent article according to any one of claims 1 to 6.

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

<Invention of Claim 8>
A method for producing a disposable absorbent article comprising a liquid-permeable surface sheet, a liquid-impermeable sheet, and an absorbent body interposed therebetween,
After the surface sheet is formed with a large number of recesses on the skin contact side surface at predetermined intervals in the front-rear direction and the width direction, the roll surface is passed through a nip roll that is corrugated in the width direction. A cross-section along the direction becomes a wave shape having a large number of wave crests and wave bottoms, and the wave crest and wave bottoms are formed in a nonwoven fabric formed so as to be continuous in the front-rear direction.
The fiber density of the bottom of the recess to be higher than ambient, and coordinated at least some of the plurality of recesses in the wave bottom,
The interval in the width direction between the wave crests is narrower than the interval between the recesses formed on the top sheet .
The manufacturing method of the disposable absorbent article characterized by the above-mentioned.

  As described above, according to the present invention, the disposable absorbent article can be provided with irregularities on the surface sheet without impairing the flexibility and texture of the skin contact surface. In addition, it is possible to prevent the excrement adhering to the surface sheet, particularly excrement having a high viscosity such as watery stool, from reattaching to the skin, and to quickly transfer to the absorbent body.

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 the upper surface schematic which shows an example of the surface sheet 30, and a cross-sectional enlarged view. (A) The upper surface schematic of the surface sheet 30 which arranged dot-like embossing, (B) The upper surface schematic of the surface sheet 30 which arranged grid-like embossing. 4 is an enlarged photograph of dot embossing of a top sheet 30. FIG. (A) Dot embossing of the topsheet 30 provided with only dot embossing, (B) Dot embossing of the topsheet 30 subjected to dot embossing and wave roll processing. 3 is a schematic cross-sectional view of the top sheet 30 in the width direction. A) The cross-sectional schematic of the width direction of the surface sheet 30 which gave only the dot embossing, (B) The cross-sectional schematic of the width direction of the surface sheet 30 which gave the dot emboss and wave roll process. It is the schematic which shows an example of the manufacturing method of a surface sheet. It is the schematic which shows the example of the shape of a wave roll. (A) Curve wave roll, (B) Rectangular wave roll, (C) Triangular wave roll.

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

  In the following description, the nonwoven fabric constituting the top sheet travels in the front-rear direction of the product consistently in heat embossing, wave roll processing, and the like. Accordingly, the “front-rear direction” of the product and the “running direction” of the various rolls in the present invention are the same direction, and the “width direction” of the product and the “width direction” of the roll are the same direction. However, the said description does not exclude making the running direction of a nonwoven fabric into the width direction of a product. Hereinafter, the description of “width direction” refers to the “width direction” of a product unless otherwise specified.

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

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

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

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

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

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

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

(Intermediate sheet)
It is preferable to provide an intermediate sheet (also referred to as a second sheet) 40 between the top sheet 30 and the absorbent element 50 in order to move excrement that has passed through the top sheet 30 to the absorber and prevent reversal. Examples of the intermediate sheet 40 include the same material as the top sheet 30, spunlace, spunbond, SMS, pulp nonwoven fabric, a mixed sheet of pulp and rayon, point bond, or crepe paper. It is preferable to use a non-woven fabric having a high (JIS L 1907 birec method), and in particular, an air-through non-woven fabric is preferable because it is bulky. When the intermediate sheet 40 is a non-woven fabric, a fiber material that is more hydrophilic than the non-woven fabric of the top sheet 30 may be used, or a material similar to the top sheet 30 provided with a hydrophilic agent may be used. May be. In the case where the surface sheet 30 is bonded by heat embossing, it is preferable to use a material having the same melting point as that of the surface sheet 30. The material constituting the nonwoven fabric may be a single material, or two or more materials may coexist by forming a core-sheath structure, a side-by-side structure, or the like.

The basis weight of the intermediate sheet 40 is preferably ²⁰ to 80 g / m ² , particularly preferably 25 to 60 g / m ² . The thickness of the intermediate sheet 40 is preferably 100 to 800 μm, particularly 200 to 600 μm. Moreover, the fiber length of the fiber which comprises a nonwoven fabric shall be 35-60 mm (more preferably 40-55 mm), and the fineness shall be 1.0-7.0 dtex (more preferably 1.5-5.0 dtex). preferable. If the fineness is lower than 1.0 dtex, the permeability of the watery stool is deteriorated, and if it is higher than 7.0 dtex, the moisture transfer from the surface sheet 30 is not smoothly performed, and a liquid residue is generated in the surface sheet 30. End up.

  The intermediate sheet 40 in the illustrated form has the same width as the top sheet 30, but may be shorter than the width of the absorbent element 50 and disposed only in the center. The length of the intermediate sheet 40 in the front-rear direction 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.

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

As the non-woven fabric constituting the top sheet 30, it is preferable to use a fabric having a basis weight of 10 to 40 g / m ² , particularly 23 to 30 g / m ² . Basis weight hard wearing differences uneven portions by heat embossing and less than 10 g / m ^2, increasing the thickness of the convex portions is higher than 40 g / m ^2, easily liquid retaining the protrusion. The thickness of the top sheet 30 is preferably 100 to 800 μm, particularly 200 to 600 μm. Moreover, the fiber length of the fiber which comprises a nonwoven fabric shall be 35-60 mm (more preferably 40-55 mm), and the fineness shall be 1.0-3.0 dtex (more preferably 2.0-3.0 dtex). preferable. The bending resistance (JIS L 1096 6.19.1 A method (45, cantilever method)) of the nonwoven fabric constituting the top sheet 30 is preferably 50 to 100 mm, particularly preferably 70 to 90 mm. When the stiffness is larger than 100 mm, the flexibility of the skin contact surface is impaired, and the wearing feeling is inferior. On the other hand, if it is smaller than 50 mm, the concavo-convex shape is difficult to be held, and it tends to be crushed.

  A schematic top view of the skin contact surface of the topsheet 30 is shown in FIG. The skin contact surface side of the top sheet 30 has a concave and convex shape due to the concave portion 81 and other portions. The concave portion 81 has a fiber density higher than that of the convex portion (portion other than the concave portion 81). As a method of providing the uneven shape on the nonwoven fabric of the topsheet, any of publicly known methods such as a method of forming with a mesh pattern at the time of nonwoven fabric formation and a method of imparting the recess 81 to the formed nonwoven fabric by heat embossing can be used. Since the fiber density needs to be higher than the convex portion in the concave portion, it is desirable to provide the concave portion on the surface sheet by a method involving compression, particularly heat embossing. The surface sheet 30 may have an uneven shape on the entire skin contact side surface, or only the wearer's excretion opening contact portion (particularly the anus contact portion) may have an uneven shape. Since the concave portion 81 formed by heat embossing has high rigidity and low flexibility, it is preferable that the area is smaller than the area of the convex portion in order not to impair the flexibility of the entire topsheet. . Although the shape of the heat embossing is not particularly limited, dot-like embossing as shown in FIG. 7A or lattice-like embossing as shown in FIG. 7B can be preferably used. The thickness of the top sheet in the recess 81 is 10 to 70%, particularly 20 to 60% of the other portions. If it exceeds 70%, it is difficult to achieve the effect of reducing the skin contact area, and if it is less than 10%, the rigidity of the recesses becomes high, and the touch and texture are inferior. The width of the recess 81 is preferably 5 to 30 mm, particularly preferably 10 to 20 mm. The interval 81d in the width direction of the recess 81 (interstitial width in the case of lattice embossing) is preferably 5 to 30 mm, particularly preferably 10 to 20 mm.

A wave crest portion 82 and a wave bottom portion are formed on the skin contact surface of the top sheet 30 so that the cross section in the width direction has a wave shape, in addition to the above-described unevenness. In the illustrated example, the wave crest portion 82 is formed over the entire length in the front-rear direction of the topsheet, but may be formed only in the central portion including the excretory opening contact portion (particularly the anus contact portion). Further, the wave crest portions 82 are all arranged in a straight line parallel to the front-rear direction. However, as long as the entire wave-crest portion 82 is along the front-rear direction of the surface sheet, the wave crest portion 82 may have a zigzag structure. (Not shown). The interval in the width direction of the wavelength portion 82 is preferably 1 to 10 mm, particularly preferably 2 to 5 mm. However, in the present invention, the interval in the width direction of the wave crest portion 82 is shorter than the interval in the width direction of the recess 81.

  A method of forming the concave portion 81 and the wave shape of the topsheet 30 is illustrated in FIG. The nonwoven fabric S forming the top sheet 30 is passed between the convex roll 92 and the flat roll 93 of the heat embossing roll 91 so that the skin contact surface is in contact with the convex roll. Next, the nonwoven fabric S is passed between wave rolls 94A and 94B having irregularities that mesh with each other. The temperature of the heat embossing roll is 100 to 180 degrees for the convex roll 92, particularly 100 to 140 degrees, the flat roll 93 is 60 to 100 degrees, particularly 70 to 90 degrees, and the nip pressure (linear pressure) is 50 to 150 KN / m, particularly 80 to 120 KN / m. As the shape of the wave roll, a curved wave (FIG. 11A), a rectangular wave (FIG. 11B), a triangular wave (FIG. 11C), etc. can be used as shown in FIG. The nip pressure of the wave roll is preferably 50 to 150 kN / m, particularly 80 to 120 kN / m. If it is less than 50 kN / m, the effect of the present invention cannot be achieved, and if it is more than 150 kN / m, the surface sheet is compressed, so that its flexibility is impaired.

  When only the dot embossing was formed, the fiber was strongly compressed in the recess 81 (FIG. 8 (A)), but by combining the wave embossing with the dot embossing, the fiber in the recess 81 was partially compressed. It can be seen that the problem is solved (FIG. 8B). FIG. 9 schematically shows a cross-sectional view in the width direction of the surface sheet 30 before and after the wave processing roll. In the example of illustration, the recessed part 81 attached | subjected to the surface sheet 30 before a wave roll process is in the state where fiber is compressed and there is no thickness than another part (FIG. 9 (A)). As shown in FIG. 9B, the concave portion 81 after the wave roll processing has a thickness larger than that before the processing, and sufficiently secures a portion that does not directly contact the skin. Thus, by combining the uneven shape by heat embossing on the top sheet and the wave shape by wave roll processing, the rigidity in the concave portion 81 can be lowered and the flexibility of the top sheet can be improved as a whole. Note that it is preferable that the positions of the concave portion 81 and the wave crest portion 82 overlap each other because the rigidity of the concave portion 81 can be further reduced, but the concave portion 81 does not necessarily overlap the wave crest portion 82.

The top sheet 30 may be passed through the heat embossing roll 91 and the wave roll 94 alone, but overlapping with the intermediate sheet 40 and passing through these rolls increases the adhesion between the top sheet 30 and the intermediate sheet 40. Is more preferable. Although the surface sheet 30 and the intermediate sheet 40 may be joined only by heat embossing, it is necessary to increase the temperature and nip pressure of the heat embossing, and the formed recess 81 may be too hard. Prior to heat embossing, both sheets may be bonded with a hot melt adhesive or the like. In this case, in the later wave roll processing, the adhesive oozes out from the fiber gap of the nonwoven fabric and adheres in a roll shape, which may cause contamination. Therefore, it is preferable to use as little adhesive as possible. For example, in the case of a hot melt adhesive, it is preferably 1.0 to 3.0 g / m ² .

  Note that the top sheet 30 may be composed of one sheet or two or more sheets in the planar direction.

(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 a synthetic fiber tow (fiber bundle) such as cellulose acetate, in addition to those obtained by stacking 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 in place of the crepe paper, a hydrophilic SMMS (spunbond / meltblown / meltblown / spunbond) nonwoven fabric is particularly suitable, and polypropylene, polyethylene / polypropylene, etc. can be used as the material. The fiber basis weight is preferably 5 to 40 g / m ² , particularly 10 to 30 g / m ² .

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

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

  In the diaper for infants, among the dimensions of the attachment portion of the fastening tape 13, the width direction length X1 of the diaper is preferably 10 to 50 mm, particularly preferably 20 to 40 mm, and the length Y1 in the front-rear direction is 20 to 100 mm. In particular, the thickness is preferably 40 to 80 mm. Of the dimensions of the front end side portion of the fastening tape 13, the length of the diaper in the width direction is preferably 30 to 80 mm, particularly preferably 40 to 60 mm, and the length (height) in the front-rear direction is 20 to 70 mm. In particular, 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 74 having a target for facilitating the locking at the locking position of the fastening tape 13 on the ventral side F. As the target sheet 74, when the hook portion is the hook material 13 </ b> A, a target sheet 74 can be used in which a large number of loop yarns are formed on the surface of a sheet base material made of a plastic film or a nonwoven fabric so that the engagement protrusions of the hook material are entangled. In the case of an adhesive material layer, a sheet base material made of a plastic film having a smooth surface that is rich in adhesiveness can be used. Further, when the fastening portion of the fastening tape 13 on the ventral side F is made of a nonwoven fabric, for example, when the exterior sheet 12 of the illustrated form is made of a nonwoven fabric and the fastening portion of the fastening tape 13 is a hook material 13A, The target sheet 74 can be omitted, and the hook material 13A can be entangled with the nonwoven fabric of the exterior sheet 12 and locked. In this case, the target sheet 74 may be provided between the exterior sheet 12 and the liquid-impermeable sheet 11.

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

  The length in the front-rear direction of the back end flap BE is preferably the same as or shorter than the length in the front-rear direction of the attachment portion of the fastening tape 13 for the reasons described above. If 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. If the contraction force is prevented from acting on a part or all of the overlapping portion by means such as cutting, the back end of the absorbent element 50 does not contract in the width direction, so that the fit is further improved.

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

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

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

  DESCRIPTION OF SYMBOLS 11 ... Liquid impervious sheet, 12 ... Exterior sheet, 30 ... Surface sheet, 40 ... Intermediate sheet, 50 ... Absorbing element, 56 ... Absorber, 58 ... Packaging sheet, 60 ... Side barrier cuff, 62 ... Barrier sheet, DESCRIPTION OF SYMBOLS 70 ... Back side elastic sheet, 74 ... Target sheet, 81 ... Surface sheet recessed part, 82 ... Wave peak part, 91 ... Heat embossing roll, 94 ... Wave roll.

Claims (8)

In a disposable absorbent article comprising a liquid-permeable surface sheet, a liquid-impermeable sheet, and an absorbent body interposed therebetween,
The surface sheet has a plurality of concave portions formed on the skin contact side surface at predetermined intervals in the front-rear direction and the width direction, and a cross section along the width direction has a wave shape having a plurality of wave crest portions and wave bottom portions, and its crest portions and the wave trough portions are formed so as to be continuous in the longitudinal direction, the fiber basis weight consists of non-woven fabric 10 to 40 g / m ^2,
The bottom of the recess has a fiber density higher than the surroundings, the thickness of the bottom of the recess is 10 to 50% of the thickness of the portion other than the recess, and at least a part of the plurality of recesses is located at the wave bottom. and it is,
The interval in the width direction between the wave crests is narrower than the interval between the recesses formed on the top sheet,
A disposable absorbent article characterized by that. In a disposable absorbent article comprising a liquid-permeable surface sheet, a liquid-impermeable sheet, and an absorbent body interposed therebetween,
After the surface sheet is formed with a large number of recesses on the skin contact side surface at predetermined intervals in the front-rear direction and the width direction, the roll surface is passed through a nip roll that is corrugated in the width direction, and the width direction The cross section along the line is a wave having a large number of wave crests and wave bottoms, and the wave crest and wave bottoms are made of a nonwoven fabric formed so as to be continuous in the front-rear direction,
Bottom of the recess has a high fiber density than the surrounding, and at least some of said plurality of depressions are located in the wave bottom,
The interval in the width direction between the wave crests is narrower than the interval between the recesses formed on the top sheet,
A disposable absorbent article characterized by that.   The disposable absorbent article according to claim 1 or 2, wherein the concave portion is formed by a large number of dot-shaped heat embosses or a lattice-shaped heat emboss made of a large number of straight lines.   The disposable absorbent article according to claim 3, wherein an interval in the width direction between the wave crests is narrower than a dot interval or a lattice interval of recesses formed on the surface sheet. Having an intermediate sheet interposed between the top sheet and the absorber,
3. The disposable absorbent article according to claim 2, wherein the top sheet is overlapped with the intermediate sheet, the concave portion is formed on the skin contact surface side, and the top sheet is passed through the nip roll together with the intermediate sheet.   The disposable absorbent article according to claim 5, wherein the intermediate sheet is a nonwoven fabric having a higher water absorption than the top sheet. The non-woven fabric of the top sheet is an air-through non-woven fabric having a fineness of raw material fibers of 1.0 to 3.0 dtex, a thickness of 0.1 to 5.0 mm, and a basis weight of 10 to 40 g / m ² .
The disposable absorbent article according to any one of claims 1 to 6. A method for producing a disposable absorbent article comprising a liquid-permeable surface sheet, a liquid-impermeable sheet, and an absorbent body interposed therebetween,
After the surface sheet is formed with a large number of recesses on the skin contact side surface at predetermined intervals in the front-rear direction and the width direction, the roll surface is passed through a nip roll that is corrugated in the width direction. A cross-section along the direction becomes a wave shape having a large number of wave crests and wave bottoms, and the wave crest and wave bottoms are formed in a nonwoven fabric formed so as to be continuous in the front-rear direction.
The fiber density of the bottom of the recess to be higher than ambient, and coordinated at least some of the plurality of recesses in the wave bottom,
The interval in the width direction between the wave crests is narrower than the interval between the recesses formed on the top sheet .
The manufacturing method of the disposable absorbent article characterized by the above-mentioned.