JP2021052901A - Absorbent article - Google Patents

Abstract

To improve viscous liquid absorbency.SOLUTION: An absorbent article includes an absorber 70 and a liquid permeable top sheet 30 arranged on the surface side of the absorber 70. The absorber 70 includes a cell absorption sheet 50 which has an upper sheet 51 and a lower sheet 52 having liquid permeability, cells 55 which are surrounded by a bonded part 54 of the upper sheet 51 and the lower sheet 52 where the upper sheet 51 and the lower sheet 52 are not bonded, and particulate matters containing high absorbent polymer particles 53 housed in the cells 55. The upper sheet 51 is highly water-absorbing nonwoven fabric whose Klemm water absorbency is 50 mm or more.SELECTED DRAWING: Figure 16

Description

The present invention relates to an absorbent article having improved absorption performance.

The absorbent article includes an absorber, a liquid-permeable top sheet that covers the front side of the absorber, and a liquid-impermeable sheet that covers the back side of the absorber, and excrement fluid such as urine and menstrual blood is a top sheet. Is absorbed and retained by the absorber. As the absorber, one in which highly absorbent polymer particles (SAP) are mixed with hydrophilic short fibers such as crushed pulp and stacked in a cotton-like shape is widely used, but while ensuring a sufficient absorbable amount, In order to meet the demands for further thinning, weight reduction, cost reduction, etc., a large number of cells are surrounded by liquid-permeable upper and lower sheet joints, and the upper and lower sheets are not joined. Various absorption sheets (hereinafter, also referred to as cell absorption sheets) having (small chambers) and powders and granules containing highly absorbent polymer particles contained in the cells have been proposed (for example, Patent Documents 1 to 6 below). reference).

However, since the cell absorption sheet depends on the highly absorbent polymer particles for its absorption performance, it is suitable for a large amount of non-viscous liquid such as urine as an absorption amount, but its absorption rate is slow. Therefore, when the object to be absorbed is a viscous liquid such as a liquid in muddy stool, watery stool, or loose stool, the viscous liquid remains on the surface of the diaper for a certain length of time, flows on the surface of the absorbent article, and moves around. There was a problem that it was easy to leak from.

Special Table No. 09-504207 Japanese Patent Application Laid-Open No. 2014-500736 Japanese Unexamined Patent Publication No. 2011-189067 Japanese Unexamined Patent Publication No. 10-137291 Japanese Unexamined Patent Publication No. 2017-176507 Japanese Unexamined Patent Publication No. 2010-522595

Therefore, a main object of the present invention is to improve the absorbability of the viscous liquid.

The absorbent articles that have solved the above problems are as follows.
<First aspect>
It comprises an absorber and a liquid permeable topsheet located on the front side of the absorber.
The absorber includes a cell in which the upper sheet and the lower sheet having liquid permeability, a cell in which the upper sheet and the lower sheet are not joined, and a cell surrounded by a joint portion between the upper sheet and the lower sheet, and the inside of the cell. Containing a cell absorbing sheet with granules containing highly absorbent polymer particles housed in
The upper sheet is a highly water-absorbent non-woven fabric having a Krem water absorption of 100 mm or more.
An absorbent article, characterized in that.

(Action effect)
Improving the permeability of the viscous liquid in the layer overlying the front side of the absorber is a conventional and common approach, which remains important, but the rapid permeation of the viscous liquid is It is promoted by rapid inhalation by the absorber. That is, the initial absorption rate at the top of the absorber is extremely important for the absorption of the viscous liquid. The absorbent article is based on this finding. This absorbent article is characterized in that a material specialized for absorbing viscous liquid is used for the upper sheet of the cell absorber. That is, the upper sheet is a highly water-absorbent non-woven fabric having a Krem water absorption degree of 100 mm or more, and even a viscous liquid can be rapidly absorbed and diffused. Therefore, the absorbability of the viscous liquid can be remarkably improved. Further, the viscous liquid absorbed and diffused by the upper sheet can be transferred to the highly absorbent polymer particles in the cell absorbing sheet, and can be absorbed and held by the highly absorbent polymer particles.

<Second aspect>
The highly water-absorbent nonwoven fabric forming the upper sheet is a wet nonwoven fabric having a ^{basis weight of 25 to 50 g / m 2 containing 50% or more of pulp fibers or rayon fibers.}
The absorbent article of the first aspect.

(Action effect)
It is preferable to use such a wet non-woven fabric because the non-viscous liquid can be rapidly absorbed and diffused due to the capillary phenomenon caused by the minute fiber gaps. Further, such a wet non-woven fabric not only has a high degree of Krem water absorption, but is also very thin and flexible, so that it is possible to suppress a decrease in flexibility and an increase in thickness of the cell absorbing sheet as a whole.

<Third aspect>
The wet non-woven fabric has a support layer containing long fibers of synthetic resin and a pulp layer located on the outermost side and composed of only pulp fibers.
The absorbent article of the second aspect.

(Action effect)
Such a wet non-woven fabric is preferable because the pulp layer can increase the water retention on the upper side of the lower sheet and the presence of the support layer can increase the strength.

<Fourth aspect>
The cell absorbing sheet contains highly absorbent polymer particles adjacent to the back surface of the upper sheet.
An absorbent article according to any one of the first to third aspects.

(Action effect)
It is preferable that the cell absorbing sheet has highly absorbent polymer particles adjacent to the back surface of the upper sheet because the viscous liquid absorbed and diffused by the upper sheet can be efficiently delivered to the highly absorbent polymer particles.

<Fifth aspect>
A portion of the upper sheet located in each cell is extruded upward, and a pair of concave portions and convex portions are formed on the upper surface and the lower surface of the upper sheet.
An absorbent article according to any one of the first to fourth aspects.

(Action effect)
In the cell absorbing sheet, in order to secure the volume when the highly absorbent polymer particles inside are absorbed and expanded, at least one of the upper sheet and the lower sheet is a recess in which the portion located in each cell is extruded outward in the thickness direction. It is preferable to have. Here, it is preferable that the upper sheet has a recess because the surface area of the upper sheet becomes large and the liquid can be supplied in a wider range to the highly absorbent polymer particles in the cell absorbing sheet.

<Sixth aspect>
A liquid impermeable sheet arranged on the back side of the absorber is provided.
The lower sheet is a highly water-absorbent non-woven fabric having a Krem water absorption of 50 mm or more, a water retention under load of 0.1 g or more, and a water retention under no load of 0.5 g or more.
An absorbent article according to any one of the first to fifth aspects.

(Action effect)
As described above, since the cell absorbing sheet has a slow absorption rate, the non-viscous liquid that has permeated the cell absorbing sheet moves on the liquid impermeable sheet and exudes from the periphery of the cell absorbing sheet to the skin side to the skin. There is a risk of sticking or leaking. On the other hand, in the present absorbent article, among the non-viscous liquids supplied to the cell absorbing sheet, the non-viscous liquid that reaches the lower sheet without being absorbed by the highly absorbent polymer particles is absorbed by the lower sheet and lower. After water is retained and diffused in the sheet, it can be sucked up by the highly absorbent polymer particles in the cell absorbing sheet. Therefore, it is possible to reduce the possibility that the non-viscous liquid that has permeated the cell absorbing sheet moves on the liquid impermeable sheet and exudes from the periphery of the cell absorbing sheet to the skin side and adheres to or leaks to the skin. it can. Further, as a result, it is possible to achieve both the absorbability of the viscous liquid and the absorption performance of the non-viscous liquid.

<7th aspect>
A portion of the lower sheet located in each cell is extruded downward, and a pair of concave portions and convex portions are formed on the upper surface and the lower surface of the lower sheet.
The absorbent article of the sixth aspect.

(Action effect)
When the lower sheet has a recess, the surface area of the lower sheet becomes large, and the amount of water retained in the lower sheet increases as compared with the case where the lower sheet is flattened without being subjected to shaping processing, which is preferable.

According to the present invention, there are advantages such as improved absorbability of the viscous liquid.

It is a top view in the unfolded state which shows the inner surface of a tape type disposable diaper. It is a top view in the unfolded state which shows the outer surface of a tape type disposable diaper. 6-6 is a sectional view taken along the line 6-6 of FIG. It is a 7-7 sectional view of FIG. (A) is a cross-sectional view taken along the line 8-8 of FIG. 1, and (b) is a cross-sectional view taken along the line 9-9 of FIG. It is a cross-sectional view of 5-5 of FIG. (A) The bottom view of the main part of the absorber, and (b) the 1-1 cross-sectional view thereof. It is a top view of the absorber. It is a top view of the absorber. It is a 2-2 sectional view of FIG. 8 and FIG. It is a top view of the absorber which showed the joint part simply. It is a schematic plan view which shows various arrangement examples of a cell. It is sectional drawing of each cell absorption sheet. It is sectional drawing of each cell absorption sheet. It is sectional drawing which shows the layer structure of an absorber and a packaging sheet. It is sectional drawing which shows the change at the time of absorption. It is sectional drawing which shows typically the layer structure of the highly water-absorbing nonwoven fabric.

Hereinafter, as an example of the absorbent article, a tape-type disposable diaper will be described with reference to the attached drawings. 1 to 6 show an example of a tape-type disposable diaper. In the figure, reference numeral X indicates the entire width of the diaper excluding the fastening tape, and reference numeral L indicates the total length of the diaper. In addition, each component member adjacent in the thickness direction is fixed or joined in the same manner as a known diaper, except for the fixing or joining portion described below. The dotted pattern portion in the cross-sectional view shows an adhesive such as a hot melt adhesive as the fixing or joining means. Known hot melt adhesives include slot coating, continuous linear or dotted bead coating, spiral, Z, wavy and other spray coating, and pattern coating (transfer of hot melt adhesive by letterpress method). It can be applied by the method. Instead of or in conjunction with this, at the fixed portion of the elastic member, a hot melt adhesive can be applied to the outer peripheral surface of the elastic member to fix the elastic member to the adjacent member. Examples of the hot melt adhesive include EVA type, adhesive rubber type (elastomer type), olefin type, polyester / polyamide type and the like, but they can be used without particular limitation. As the fixing or joining means for joining each component, a means by material welding such as heat sealing or ultrasonic sealing can also be used. In the portion where the liquid permeability in the thickness direction is required, the constituent members adjacent to each other in the thickness direction are fixed or joined in an intermittent pattern. For example, when such intermittent fixing or joining is performed with a hot melt adhesive, intermittent pattern coating such as spiral shape, Z shape, and wavy shape can be preferably used, and the coating width is within a range equal to or larger than the coating width by one nozzle. In the case of coating, it is possible to apply an intermittent pattern such as a spiral shape, a Z shape, or a wavy shape with or without a gap in the width direction.

This tape-type disposable diaper has a basic structure in which an absorber 70 is interposed between a liquid-permeable top sheet and a liquid-impermeable sheet located on the back side. In addition, this tape-type disposable diaper has an end flap EF that extends to the front side and the rear side of the absorber 70, respectively, and does not have the absorber 70, and has a side edge of the absorber 70. It has a pair of side flap SFs that extend laterally. Both side edges of the side flap SF have a shape constricted along the circumference of the legs, but may be linear. Fastening tapes 13 are provided on the side flap SFs on the dorsal side portion B, respectively, and when wearing a diaper, the side flap SFs on the dorsal side portion B are overlapped on the outside of the side flap SFs on the ventral side portion F. , Fastening tape 13 is locked in place on the outer surface of the ventral portion F.

Further, in this tape type disposable diaper, the entire outer surface other than the fastening tape 13 is formed of the exterior non-woven fabric 12. In particular, in the region including the absorber 70, the liquid-impermeable sheet 11 is fixed to the inner surface side of the exterior nonwoven fabric 12 with an adhesive such as a hot melt adhesive, and is further absorbed by the liquid-impermeable sheet 11 on the inner surface side. The body 70, 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 LD and the width direction WD than the absorber 70, and have side edges of the absorber 70 in the top sheet 30. The peripheral portion that protrudes from the side edge of the absorbent body 70 in the liquid impermeable sheet 11 is joined by a hot melt adhesive or the like. Further, the liquid impermeable sheet 11 is formed to be slightly wider than the top sheet 30.

Further, rising gathers 60 that stand up on the skin side of the wearer are provided on both sides of the absorbent main body 10, and gather sheets 62 forming the rising gathers 60 are formed on both sides of the top sheet 30. It is fixed to the inner surface of the side flap SF.

Hereinafter, the details of each part will be described in order. As the non-woven fabric in the following description, a known non-woven fabric can be appropriately used depending on the site and purpose. Examples of the constituent fibers of the non-woven fabric include olefin-based fibers such as polyethylene and polypropylene, polyester-based and polyamide-based synthetic fibers (including single-component fibers and composite fibers such as core sheaths), as well as recycled rayon and cupra. Fibers, natural fibers such as cotton, and the like can be selected without particular limitation, and these can be mixed and used. In order to increase the flexibility of the non-woven fabric, it is preferable that the constituent fibers are crimped fibers. Further, the constituent fibers of the non-woven fabric include hydrophobic fibers or water-repellent fibers (including fibers made water-repellent by the water-repellent agent) even if they are hydrophilic fibers (including fibers made hydrophilic by the hydrophilic agent). ) May be. In addition, the non-woven fabric generally has a short fiber non-woven fabric, a long fiber non-woven fabric, a spunbond non-woven fabric, a melt blown non-woven fabric, a spunlace non-woven fabric, a thermal bond (air-through) non-woven fabric, and a needle punch depending on the fiber length, the sheet forming method, the fiber bonding method, and the laminated structure. It is classified into non-woven fabrics, point-bonded non-woven fabrics, laminated non-woven fabrics (SMS non-woven fabrics having a melt blown layer sandwiched between spunbond layers, SMMS non-woven fabrics, etc.), and any of these non-woven fabrics can be used.

(Exterior non-woven fabric)
The exterior non-woven fabric 12 constitutes the outer surface of the product, and is intended to give the outer surface of the product a cloth-like appearance and feel. The fiber basis weight of the exterior non-woven fabric is preferably ^{10 to 50 g / m 2} , especially 15 to 30 g / m ^2. The exterior non-woven fabric 12 can be omitted, in which case the liquid-impermeable sheet 11 can have the same shape as the exterior non-woven fabric 12 to form the outer surface of the product.

(Liquid impermeable sheet)
The material of the liquid-impermeable sheet 11 is not particularly limited, but is substantially, for example, an olefin resin such as polyethylene or polypropylene, a laminated non-woven fabric in which a non-woven fabric is laminated on a polyethylene sheet or the like, or a waterproof film. Examples thereof include a non-woven fabric that ensures liquid impermeableness (in this case, the waterproof film and the non-woven fabric form a liquid-impermeable sheet). Of course, in addition to this, a material having liquid impermeableness and moisture permeability, which has been favorably used from the viewpoint of preventing stuffiness in recent years, can also be exemplified. As a sheet of this liquid-impermeable and moisture-permeable material, for example, an inorganic filler is kneaded in an olefin resin such as polyethylene or polypropylene to form a sheet, which is then stretched in a uniaxial or biaxial direction. The microporous sheet obtained in the above can be exemplified. Furthermore, it is waterproofed by a non-woven fabric using microdenyl fibers, strengthening of leakage resistance by reducing the voids of the fibers by applying heat or pressure, and coating with a highly water-absorbent resin or hydrophobic resin or water repellent. A liquid-impermeable sheet without using a film can also be used as the liquid-impermeable sheet 11.

(Top sheet)
The top sheet 30 has a property of allowing liquid to permeate, and examples thereof include a perforated or non-perforated non-woven fabric and a porous plastic sheet. Both sides of the top sheet 30 may be folded back to the back side of the absorber 70, or may protrude laterally from the side edge of the absorber 70 without being folded back, as shown in the illustrated example.

The top sheet 30 may be fixed to a member adjacent to the back side by a joining means by material welding such as a heat seal or an ultrasonic seal, or by a hot melt adhesive for the purpose of preventing misalignment with respect to the member on the back side. desirable. In the illustrated example, the top sheet 30 is fixed to the surface of the intermediate sheet 40 and the surface of the packaging sheet 45 located on the front side of the absorber 70 by a hot melt adhesive applied to the back surface thereof.

(Intermediate sheet)
The intermediate sheet 40 is joined to the back surface of the top sheet 30 in order to quickly move the excrement liquid that has passed through the top sheet 30 toward the absorber 70 and to prevent reversion. In addition to using a hot melt adhesive, heat embossing or ultrasonic welding can also be used to join the intermediate sheet 40 and the top sheet 30.

As the intermediate sheet 40, in addition to using a non-woven fabric, a resin film having a large number of through holes can also be used. As the non-woven fabric, the same material as the top sheet 30 can be used, but those having higher hydrophilicity than the top sheet 30 and those having a higher fiber density have the characteristics of liquid transfer from the top sheet 30 to the intermediate sheet 40. It is preferable because it is excellent. For example, as the intermediate sheet 40, an air-through non-woven fabric can be preferably used. It is preferable to use a composite fiber having a core-sheath structure for the air-through non-woven fabric. In this case, the resin used for the core may be polypropylene (PP), but polyester (PET) having high rigidity is preferable. Basis weight is preferably ^{17~80g / m 2, 25~60g / m} 2 is more preferable. The thickness of the raw material fiber of the non-woven fabric is preferably 2.0 to 10 dtex. In order to make the non-woven fabric bulky, it is also preferable to use eccentric fibers having no core in the center, hollow fibers, and eccentric and hollow fibers as mixed fibers of all or a part of the raw material fibers.

Although the intermediate sheet 40 of the illustrated example is arranged in the center shorter than the width of the absorber 70, it may be provided over the entire width. The dimension of the front-rear LD of the intermediate sheet 40 may be the same as the total length of the diaper, the dimension of the absorber 70 may be the same, or the dimension may be within a short length range centered on the region for receiving the liquid.

(Get up gather)
In order to prevent lateral movement of excrement on the top sheet 30 and prevent lateral leakage, it is preferable to provide rising gathers 60 that protrude (stand up) from the inner surfaces on both sides of the product in the width direction WD.

The rising gather 60 is composed of a gather sheet 62 and an elongated gather elastic member 63 fixed to the gather sheet 62 in an extended state along the LD in the front-rear direction. A water-repellent non-woven fabric can be used as the gather sheet 62, and a rubber thread or the like can be used as the elastic member 63. As shown in FIGS. 1 and 3, a plurality of elastic members may be provided, and one elastic member may be provided.

The inner surface of the gather sheet 62 has a fixing start end of the width direction WD on the side portion of the top sheet 30, and the outer portion of the width direction WD from the fixing start end is the side portion of the liquid impermeable sheet 11 and the portion thereof. It is fixed to the side portion of the exterior nonwoven fabric 12 located in the above with a hot melt adhesive or the like.

Around the legs, the inside of the WD in the width direction from the fixed start end of the rising gather 60 is fixed on the top sheet 30 at both ends of the LD in the front-rear direction of the product, but the part between them is a non-fixed free part. This free portion stands up due to the contraction force of the elastic member 63. When the diaper is worn, the diaper is mounted on the body in a boat shape, and the contraction force of the elastic member 63 acts on the diaper. Therefore, the contraction force of the elastic member 63 causes the gathers 60 to stand up and come into close contact with the legs. As a result, so-called lateral leakage from around the legs is prevented.

Unlike the illustrated example, both ends of the front-rear LD in the inner portion of the width direction WD of the gather sheet 62 are the proximal end side portion extending inward from the outer portion of the width direction WD and the proximal end side portion. Folded from the central edge of the width direction WD to the body side and fixed in a folded state having a tip side part extending to the outside of the width direction WD, and the part in between is an unfixed free part. You can also.

(Plane gather)
In each side flap SF, as shown in FIGS. 1 to 3, between the gather sheet 62 and the liquid permeable sheet 11 on the outside of the widthwise WD near the fixing start end of the fixing portion of the gather sheet 62. , The leg circumference elastic member 64 made of an elongated elastic member such as rubber thread is fixed in a state of being extended along the front-rear direction LD, whereby the leg circumference portion of each side flap SF is configured as a flat gather. ing. The leg-surrounding elastic member 64 can also be arranged between the liquid-impermeable sheet 11 and the exterior non-woven fabric 12 in the side flap SF. A plurality of elastic members 64 around the legs may be provided on each side as shown in the illustrated example, or only one elastic member 64 may be provided on each side.

(Fastening tape)
As shown in FIGS. 1, 2 and 6, the fastening tape 13 is a sheet base material forming a tape mounting portion 13C fixed to the side portion of the diaper and a tape main body portion 13B protruding from the tape mounting portion 13C. And a locking portion 13A with respect to the ventral side provided in the middle portion of the tape main body portion 13B in the sheet base material in the width direction WD, and the tip side from the locking portion 13A is a knob portion. is there. The tape attachment portion 13C of the fastening tape 13 is sandwiched between the gather sheet 62 forming the inner layer and the outer non-woven fabric 12 forming the outer layer in the side flap SF, and is adhered to the sheets with a hot melt adhesive. Further, the locking portion 13A is fixed to the sheet base material with an adhesive.

As the locking portion 13A, a hook material (male material) of a mechanical fastener (hook-and-loop fastener) is suitable. The hook material has a large number of engaging protrusions on its outer surface side. As the shape of the engaging protrusion, there are a checkered shape, a J-shaped shape, a mushroom shape, a T-shaped shape, a double J-shaped shape (a shape in which J-shaped ones are joined back to back), and the like. It may be in the shape of. Of course, an adhesive layer can be provided as a locking portion of the fastening tape 13.

The sheet base material forming the tape mounting portion 13C to the tape main body portion 13B includes various non-woven fabrics such as spunbonded non-woven fabric, air-through non-woven fabric, and spunlaced non-woven fabric, as well as plastic film, polylami non-woven fabric, paper, and composite materials thereof. Can be used.

(Target sheet)
It is preferable to provide a target sheet 12T having a target for facilitating locking at the locking portion of the fastening tape 13 in the ventral portion F. When the locking portion 13A is a hook material, the target sheet 12T may be one in which a large number of loop threads are provided on the surface of a sheet base material made of a plastic film or a non-woven fabric so that the engaging protrusions of the hook material are entangled. Further, in the case of the pressure-sensitive adhesive layer, one in which the surface of a sheet base material made of a plastic film having a smooth surface, which is highly adhesive, is subjected to a peeling treatment can be used. Further, when the locking portion of the fastening tape 13 on the ventral side portion F is made of a non-woven fabric, for example, when the exterior non-woven fabric 12 of the illustrated example is made of a non-woven fabric and the locking portion 13A of the fastening tape 13 is a hook material. Can omit the target sheet 12T and entangle the hook material with the non-woven fabric of the exterior non-woven fabric 12 to lock the non-woven fabric. In this case, the target sheet 12T may be provided between the exterior non-woven fabric 12 and the liquid impermeable sheet 11.

(Absorber)
As shown in FIGS. 1, 3, 5, and 15, the absorber 70 is a portion that absorbs and retains the liquid content of excrement. The absorber 70 can be adhered to at least one of the front and back members via an adhesive 50h such as a hot melt adhesive.

As shown in the illustrated example, the absorber 70 is surrounded by a joint portion 54 of the upper sheet 51 and the lower sheet 52 having liquid permeability, and a large number of cells 55 to which the upper sheet 51 and the lower sheet 52 are not joined are not joined. It is preferable that the cell absorbing sheet 50 has (small chamber) and a powder or granular material containing the highly absorbent polymer particles 53 contained in the cell 55.

The cell absorbing sheet 50 will be described in more detail. As shown enlarged in FIG. 7, the cell absorbing sheet 50 is surrounded by an upper sheet 51, a lower sheet 52 arranged on the back side thereof, and a joint portion 54 between the upper sheet 51 and the lower sheet 52. Moreover, it has a cell (small chamber) 55 in which the upper sheet 51 and the lower sheet 52 are non-bonded portions, and highly absorbent polymer particles 53 contained in the cell 55. A large number of cells 55 are arranged at intervals of the joint portion 54. By distributing and holding the highly absorbent polymer particles 53 in a large number of cells 55 surrounded by the joint portion 54 in this way, it is possible to prevent uneven distribution of the highly absorbent polymer particles 53 in the cell absorbing sheet 50.

At least one of the upper sheet 51 and the lower sheet 52 in the cell 55 is outside the cell 55 in the expanded state in order to facilitate the arrangement of the highly absorbent polymer particles 53 during production and to secure the volume after absorption expansion. It is preferable that the recess 50c is recessed in the center, but the recess 50c may not be provided, and the highly absorbent polymer particles 53 may be simply sandwiched between the upper sheet 51 and the lower sheet 52.

The recess 50c can be formed by subjecting the target sheet to a shaping process such as embossing. Further, by this embossing, a convex portion 50p that bulges outward is formed in the portion of the target sheet located at each cell 55. That is, when the concave portion 50c is formed in the upper sheet 51 by embossing, the portion of the upper sheet 51 located at each cell 55 is extruded upward to form a convex portion 50p that bulges upward. The depth 50d of the recess 50c is not particularly limited, but is preferably 1.0 to 7.0 mm, particularly about 1.0 to 5.0 mm.

The dimensions of the convex portion 50p can be appropriately determined, but from such a viewpoint, the dimension 55L of the convex portion 50p in the front-rear direction LD of the upper sheet 51 is 6 to 30 mm, and the width direction of the convex portion 50p of the upper sheet 51. The WD dimension 55W is 7 to 50 mm, the width 54W of the joint 54 is 1.0 to 1.8 mm, and the valley depth 50d (convex 50p height) of the upper sheet 51 is 1.0. It is preferably about 7.0 mm.

On the other hand, as shown in FIGS. 7 (b) and 13 (a), it is preferable that a middle sheet 80 made of a non-woven fabric is interposed between the upper sheet 51 and the lower sheet 52, but FIG. 14 (b). ), It is not necessary to provide the middle sheet 80. When the middle sheet 80 is provided, the upper sheet 51, the middle sheet 80, and the lower sheet 52 are joined at the joint portion 54. Further, it is preferable that the middle sheet 80 is compressed in the thickness direction at the joint portion 54 and swells into the recess 50c at the portion located in the cell 55 (in other words, the fiber density decreases as the distance from the joint portion increases). .. As a result, the concave portion 50c (and therefore the convex portion) is not easily crushed by the pressure applied in the packaging state of the product or the pressure applied at the time of mounting, and even if the concave portion 50c is crushed, at least the portion where the middle sheet 80 has entered due to the elasticity of the middle sheet 80. Shape restoration is promoted to a volume close to or close to that. Then, at the time of absorption of the excrement liquid, the highly absorbent polymer expands the fiber gaps and can expand by entering the interfiber gaps, easily compressing the middle sheet 80, or both, so that the middle sheet 80 can be expanded. The presence is less likely to inhibit the expansion of the highly absorbent polymer particles 53. Further, since the fibers of the middle sheet 80 spreading in the recess 50c secure a liquid passage to the individual highly absorbent polymer particles 53, the decrease in diffusivity is suppressed even after the highly absorbent polymer particles 53 start expanding. And gel blocking is less likely to occur. Therefore, due to these synergistic actions, the absorption rate (particularly at the initial stage of absorption) of the disposable diaper provided with the cell absorption sheet 50 is improved.

(Upper sheet)
The upper sheet 51 is preferably a highly water-absorbent non-woven fabric having a Krem water absorption of 100 mm or more. By providing such an upper sheet 51, as shown by an arrow in FIG. 16A, even the viscous liquid N is rapidly absorbed and diffused, and is delivered to the highly absorbent polymer particles 53 to be delivered to the highly absorbent polymer particles 53. It can be absorbed and retained by the particles 53. Therefore, the absorbability of the viscous liquid by the absorber 70 can be remarkably improved. In particular, when the cell absorbing sheet 50 has the highly absorbent polymer particles 53 adjacent to the back surface of the upper sheet 51, the viscous liquid N absorbed and diffused by the upper sheet 51 can be efficiently delivered to the highly absorbent polymer particles. preferable.

The highly water-absorbent non-woven fabric forming the upper sheet 51 is particularly preferably having a Krem water absorption of 130 mm or more. Further, the upper limit of the Krem water absorption of the highly water-absorbent non-woven fabric forming the upper sheet 51 is not particularly limited, but is preferably about 180 mm, particularly preferably 160 mm.

The amount of water retained under load of the highly water-absorbent nonwoven fabric 42 of the upper sheet 51 is preferably greater than 0 g and 0.15 g or less, and particularly preferably greater than 0 g and 0.12 g or less. The amount of water retained under no load by the highly water-absorbent nonwoven fabric 42 of the upper sheet 51 is preferably greater than 0 g and 0.7 g or less, and particularly preferably greater than 0 g and 0.3 g or less.

The highly water-absorbent non-woven fabric forming the upper sheet 51 is not limited by the material and the manufacturing method, but is ^{a wet non-woven fabric having a grain size of 25 to 50 g / m 2} (particularly a wet spunlace non-woven fabric) containing 50% or more of pulp fiber or rayon fiber. Is preferable. As the fiber other than the pulp fiber or rayon fiber, an olefin-based fiber such as polyethylene or polypropylene, a polyester-based fiber, a polyamide-based synthetic fiber (including a composite fiber such as a core sheath as well as a single component fiber) can be used. It is preferable to use such a wet non-woven fabric because the viscous liquid can be rapidly absorbed and diffused due to the capillary phenomenon caused by the minute fiber gaps. In particular, such a wet non-woven fabric not only has a high degree of Krem water absorption, but is also very thin and flexible, so that it is possible to suppress a decrease in flexibility and an increase in thickness of the cell absorbing sheet 50 as a whole. The thickness of the highly water-absorbent nonwoven fabric forming the upper sheet 51 is not limited, but in the case of the above-mentioned basis weight, it is preferably about 0.13 to 0.48 mm.

Further, as the highly water-absorbent nonwoven fabric forming the upper sheet 51, as shown in FIG. 17, it has a support layer 42b containing long fibers of synthetic resin and a pulp layer 42a located on the outermost side and composed of only pulp fibers. A layer, or a highly water-absorbent non-woven fabric 42 having three or more layers is particularly suitable. Such a highly water-absorbent non-woven fabric 42 is preferable because the pulp layer 42a can increase the Krem water absorption and the presence of the support layer 42b can increase the strength.

When the upper sheet 51 has the recess 50c, the surface area of the upper sheet 51 becomes large, and the liquid can be supplied to the highly absorbent polymer particles in the cell absorbing sheet 50 in a wider range, which is preferable.

The material of the lower sheet 52 is not particularly limited, but it is a highly water-absorbent non-woven fabric having a Krem water absorption of 50 mm or more, a water retention under load of 0.1 g or more, and a water retention under no load of 0.5 g or more. preferable. As shown by an arrow in FIG. 16B, the non-viscous liquid U such as urine supplied to the cell absorption sheet 50 is absorbed by the highly absorbent polymer particles 53 in the cell absorption sheet 50 and has high absorbency. The non-viscous liquid U that has reached the lower sheet 52 without being absorbed by the polymer particles 53 is absorbed by the lower sheet 52, retained in the lower sheet 52, diffused, and then the highly absorbent polymer particles in the cell absorbing sheet 50. It can be sucked up by 53. When the cell absorbing sheet 50 has a joint portion 54 having no highly absorbent polymer particles 53 extending continuously toward the periphery of the cell absorbing sheet 50 and having a convex portion 50p on the back surface of the cell absorbing sheet 50. The gap between the back surface and the facing surface of the cell absorbing sheet 50 also extends continuously toward the periphery of the cell absorbing sheet 50. Therefore, when the water retention of the cell absorbing sheet 50 is low, the non-viscous liquid U that has permeated the cell absorbing sheet 50 moves on the liquid impermeable sheet 11 and exudes from the periphery of the absorbent body 70 to the skin side. It may adhere to the skin or leak.

The Krem water absorption of the highly water-absorbent non-woven fabric forming the lower sheet 52 is particularly preferably 70 mm or more. The upper limit of the Krem water absorption of the highly water-absorbent non-woven fabric forming the lower sheet 52 is not particularly limited, but is preferably about 150 mm, particularly preferably 100 mm. The amount of water retained under load of the highly water-absorbent non-woven fabric forming the lower sheet 52 is particularly preferably 0.13 g or more. The upper limit of the amount of water retained under load of the highly water-absorbent nonwoven fabric forming the lower sheet 52 is not particularly limited, but is preferably about 0.30 g, particularly preferably 0.26 g. The amount of water retained under no load of the highly water-absorbent non-woven fabric forming the lower sheet 52 is particularly preferably 0.70 g or more. The upper limit of the amount of water retained under load of the highly water-absorbent nonwoven fabric forming the lower sheet 52 is not particularly limited, but is preferably about 1.40 g, particularly preferably 1.20 g.

As the highly water-absorbent non-woven fabric forming the lower sheet 52, the same highly water-absorbent non-woven fabric as the upper sheet 51 can be preferably used. When the joint portion 54 of the upper sheet 51 and the lower sheet 52 is formed by welding, the highly water-absorbent non-woven fabric forming the lower sheet 52 is preferably a heat-welded fiber such as a polyethylene fiber or a composite fiber containing a polyethylene component. Since the purpose of the highly water-absorbent non-woven fabric used for the lower sheet 52 is to temporarily store the non-viscous liquid U such as urine, it is preferable that the non-woven fabric has a larger amount of water retention than the upper sheet 51. For example, the highly water-absorbent non-woven fabric forming the lower sheet 52 preferably has a water retention capacity under load of 2 to 4 times that of the high water-absorbent non-woven fabric of the upper sheet 51. More specifically, the texture of the highly water-absorbent non-woven fabric forming the lower sheet 52 should be 1.2 to 1.8 times the texture of the highly water-absorbent non-woven fabric forming the lower sheet 52, or as the highly water-absorbent non-woven fabric forming the lower sheet 52. A plurality of highly water-absorbent non-woven fabrics equivalent to the upper sheet 51 can be stacked and arranged.

When the lower sheet 52 has a recess 50c, the surface area of the lower sheet 52 becomes large, and the amount of water retained in the lower sheet 52 increases as compared with the case where the lower sheet 52 is flattened without being subjected to shaping processing, which is preferable.

The medium sheet 80 is not particularly limited as long as it is a non-woven fabric, but the fineness of the constituent fibers of the non-woven fabric is preferably about 1.6 to 7.0 dtex, and more preferably 5.6 to 6.6 dtex. The porosity of the non-woven fabric of the middle sheet 80 is preferably 80 to 98%, more preferably 90 to 95%. When the fineness and porosity of the middle sheet 80 are within this range, the high-absorbent polymer particles 53 ensure the elasticity of the middle sheet 80 as much as possible, and the middle sheet 80 is used before and during the absorption of the excrement liquid. It becomes possible to easily enter the fiber gap of. Therefore, since the fibers of the middle sheet 80 that spread in the recess 50c at the time of absorption secure a liquid passage to the individual highly absorbent polymer particles 53, the diffusibility is lowered even after the highly absorbent polymer particles 53 start expanding. Is suppressed, and gel blocking is less likely to occur. The thickness of the middle sheet 80 may be appropriately determined in consideration of the depth 50d of the recess 50c, the degree of penetration into the recess 50c, etc., but the thickness is 10% to 90% of the depth 50d of the recess 50c. It is preferably 70% to 90%, and more preferably 70% to 90%. The basis weight of the middle sheet 80 may be appropriately determined for the same reason, but it is preferably about ^{25 to 40 g / m 2 in the above thickness range.} In order to increase the porosity of the non-woven fabric of the middle sheet 80 (widen the fiber gaps), it is preferable that the constituent fibers are crimped fibers. Further, when the constituent fibers of the non-woven fabric of the middle sheet 80 are hydrophilic fibers (including fibers made hydrophilic by the hydrophilic agent), the water retention property is high, and when the non-woven fabric is a hydrophobic fiber, the diffusibility is improved. The fiber bonding method of the non-woven fabric is not particularly limited, but an air-through non-woven fabric in which the fibers are bonded by hot air heating is used as the middle sheet in order to sufficiently bond the fibers to ensure elasticity while increasing the porosity (widening the fiber gap). 80 is preferable.

As long as the surface of the middle sheet 80 facing the recess 50c is in the recess 50c, it is in contact with the inner surface of the recess 50c as shown in FIGS. 13 (a) (c) and 14 (a) (c), respectively. It is preferable that they are present, but they may be separated as shown in FIG. 13 (b). When the surface of the middle sheet 80 facing the recess 50c and the inner surface of the recess 50c are separated from each other, the separation distance 80s can be appropriately determined, but is preferably 30% or less of the depth 50d of the recess 50c. As described above, when a gap is generated in the cell 55, the convex portion 50p (recessed portion 50c) may be crushed according to the gap in the product state.

As shown in FIGS. 13 (a) to 13 (c) and 14 (a), the middle sheet 80 is provided with respect to at least one of the upper sheet 51 and the lower sheet 52 in both the cell 55 and the joint portion 54. It may be adhered by the hot melt adhesive 80h, or may not be adhered to both the upper sheet 51 and the lower sheet 52 as shown in FIG. 14 (c).

It is preferable that almost all of the highly absorbent polymer particles 53 (for example, 95% or more) are not fixed to the upper sheet 51, the lower sheet 52, and the middle sheet 80 so that they can move freely. However, some or almost all (eg, 95% or more) of the highly absorbent polymer particles 53 can also be adhered or adhered to at least one of the upper sheet 51, the lower sheet 52 and the middle sheet 80. FIG. 14B shows an example in which a part of the highly absorbent polymer particles 53 is adhered to the lower sheet 52 with an adhesive 53h such as a hot melt adhesive. Further, the highly absorbent polymer particles 53 may be agglomerated to some extent. In particular, when the highly absorbent polymer particles 53 are freely movable in the cell 55, if the cell 55 has a hollow portion, the highly absorbent polymer particles 53 move in the cell 55 during use, so that the sound is produced. Absorption may be hindered due to peeling or uneven distribution of the highly absorbent polymer particles 53 in the cell 55. Therefore, in order to solve this, as described above, the surface of the middle sheet 80 facing the recess 50c is brought into contact with the inner surface of the recess 50c, that is, the high porosity is high over almost the entire cell 55 including the recess 50c. Filling the fibers of the middle sheet 80 is one preferred form. As a result, the highly absorbent polymer particles 53 are captured by the fibers of the middle sheet 80, pressed against the upper sheet 51 and / or the lower sheet 52, or both, so that free movement is less likely to occur. Therefore, while preventing the expansion inhibition of the high absorption polymer particles 53, the generation of sound due to the movement of the high absorption polymer particles 53 and the absorption inhibition due to the uneven distribution of the high absorption polymer particles 53 in the cell 55 are prevented. can do.

As shown in the examples shown in FIGS. 13 (a), 13 (b) and 14 (c), the highly absorbent polymer particles 53 are most abundant on the upper surface of the middle sheet 80, and are downward from there. When the amount is reduced, it is preferable that when the user touches the outer surface of the diaper by hand, the interposition of the middle sheet 80 makes it difficult for the jerky touch (uncomfortable feeling) of the highly absorbent polymer particles 53 to be transmitted to the hand. In particular, when the middle sheet 80 is a bulky non-woven fabric having a high porosity, the highly absorbent polymer particles 53 can enter the fiber gaps of the middle sheet 80 before and during the absorption of the excrement liquid. The absorption rate is further improved. That is, in the initial stage of absorption, absorption proceeds on the upper surface of the middle sheet 80 in which a large amount of highly absorbent polymer particles 53 are distributed, but the rate is limited. Therefore, at the initial stage of this absorption, the excrement liquid enters a large amount in the middle sheet 80, which has few high-absorbent polymer particles 53, and is absorbed by the high-absorbent polymer particles 53 in the middle sheet 80, or is a high-absorbent polymer. It is temporarily stored until it is absorbed by the particles 53, or diffuses into the surrounding cells 55. The excrement liquid diffused to the surroundings is absorbed by the highly absorbent polymer particles 53 in the middle sheet 80 existing there, or is sucked up by the highly absorbent polymer particles 53 present in large quantities above it. Then, in the process in which each of the highly absorbent polymer particles 53 absorbs the excrement liquid, the highly absorbent polymer expands the fiber gaps and expands while entering between them or compressing the middle sheet 80. By such an absorption mechanism, the excrement liquid is rapidly diffused over a wide area of the cell absorption sheet 50 and is in a state of being received inside the cell absorption sheet 50, so that not only the absorption rate is improved but also the reversion prevention property is achieved. It will be excellent. Further, in order to exert such an absorption mechanism satisfactorily, it is preferable that the recess 50c is formed at least in a portion of the upper sheet 51 that constitutes each cell 55.

The degree of distribution of the highly absorbent polymer particles 53 in the cell 55 can be appropriately determined, but usually, the weight ratio of the highly absorbent polymer particles 53 present on the upper surface of the middle sheet 80 is 50% or more of the total amount. The weight ratio of the highly absorbent polymer retained in the middle sheet 80 (that is, not on the lower sheet 52) is preferably 45% or more of the total amount.

Of course, the distribution of the highly absorbent polymer particles 53 in the cell 55 is not limited to this. Therefore, if the suction property from the highly absorbent non-woven fabric forming the lower sheet 52 is emphasized, the highly absorbent polymer particles 53 are most present on the upper surface of the lower sheet 52 as shown in FIG. 13 (c). , It is also preferable to have a distribution that decreases upward from there. Further, as shown in FIG. 14A, the amount of the highly absorbent polymer particles 53 present on the upper surface of the middle sheet 80 and the upper surface of the lower sheet 52 is larger than that in the portion between them. You may. Further, although not shown, the distribution may be such that the highly absorbent polymer particles 53 are most abundant in the middle of the middle sheet 80 in the thickness direction and decrease from there toward the upper side and the lower side. This form can be formed by forming the middle sheet 80 into a two-layer non-woven fabric and sandwiching the highly absorbent polymer particles 53 between the layers.

The basis weight of the highly absorbent polymer particles 53 may be appropriately determined, but in the usual case, it can be, for example, 150 to 250 g / m ² . Generally, if the texture of the highly absorbent polymer particles 53 ^{is less than 150 g / m 2,} it is difficult to secure the absorption amount, and if it ^{exceeds 250 g / m 2} , the highly absorbent polymer particles 53 when the user touches the outer surface of the product by hand. It makes it easier to feel the squishy feel (uncomfortable feeling) in your hands.

The planar shape of the cell 55 can be appropriately determined, and as shown in FIG. 8 and the like, it can be a hexagon, a rhombus, a square, a rectangle, a circle, an ellipse, etc. It is desirable to have a rectangular shape, and it is desirable to arrange them without gaps as shown in the illustrated example. In the cell 55, in addition to arranging objects having the same shape and the same size, a plurality of types of cells 55 having different shapes and dimensions, which are not shown, may be arranged in combination.

The planar arrangement of the cells 55 (that is, the gathering portion of the highly absorbent polymer particles 53 is also the same) can be appropriately determined, but a regularly repeated planar arrangement is preferable, and an oblique lattice shape as shown in FIG. 12 (a) is preferable. Or, a hexagonal grid as shown in FIG. 12 (b) (these are also called staggered), a square grid as shown in FIG. 12 (c), and a rectangular grid as shown in FIG. 12 (d). Parallelepiped lattice as shown in 12 (e) (as shown in the figure, two groups of parallel diagonal rows are provided so as to intersect each other), etc. (These are 90 with respect to the expansion and contraction direction). In addition to those that repeat regularly, such as those that are tilted at an angle less than a degree), the group of cells 55 (the arrangement of the group units may be regular or irregular, and may be patterns, letters, etc.) is the rule. It can also be repeated.

The dimensions of each cell 55 can be appropriately determined, for example, the dimension 55L of the front-rear direction LD (equal to the size of the front-rear direction LD of the convex portion 50p) can be about 6 to 30 mm, and the size of the width direction WD 55W. (Equivalent to the dimension of the WD in the width direction of the convex portion 50p) can be about 7 to 50 mm. The area of each cell 55 can be about ^{31 to 1650 mm 2.}

The joint portion 54 for joining the upper sheet 51 and the lower sheet 52 is preferably joined by welding the upper sheet 51 and the lower sheet 52 as in ultrasonic welding or heat sealing, but via a hot melt adhesive. It may be joined.

The joint portion 54 of the upper sheet 51 and the lower sheet 52 is arranged so as to surround each cell 55, and is intermittent as shown in the illustrated example as long as it is a boundary between adjacent cells. ), It can also be formed in a continuous linear shape. When the joint portion 54 is formed intermittently, it is preferable that the highly absorbent polymer particles 53 are absent or, if any, less than in the cell 55 between the joint portions 54 in the direction surrounding the cell 55. In particular, if the joints are provided in a dotted line (intermittent), the fibers of the middle sheet will pass between the adjacent joints and extend between a large number of cells. Therefore, since the liquid diffusion passage is formed between the adjacent joints, the absorption rate can be improved by improving the liquid diffusibility between the cells.

As shown in FIG. 10, even if the joint portion 54 is a weak joint portion 54b that can be peeled off by the expansion force of the highly absorbent polymer particles 53 in the adjacent cell 55, the height in the adjacent cell 55 is also high. It may be a strong joint portion 54a that basically does not peel off due to the expansion force of the absorbent polymer particles 53. In order to cope with the expansion of the highly absorbent polymer particles 53 having an individual cell 55 volume or more, it is preferable that a part or all of the joint portion 54 is a weak joint portion 54b. By having the weakly joined portion 54b, the cells 55 adjacent to each other across the weakly joined portion 54b are separated and united by the absorption expansion pressure of the highly absorbent polymer particles 53 in the cell 55, and are united into one large cell 55. It becomes possible to become.

On the other hand, since the strong bonding portion 54a is a portion that basically does not peel off even if the cells 55 on both sides thereof absorb and expand, the diffusibility is improved by continuing in a specific direction, or the highly absorbent polymer particles 53 It has the effects of preventing the flow of the gelled product and reducing the contact area on the surface side. Therefore, by combining this with the weakly joined portion, the cell absorbing sheet 50 having various features can be constructed as described later. The joint portion 54 located on the outermost side in the width direction WD is designated as a strong joint portion 54a because if it is peeled off, the highly absorbent polymer particles 53 or a gelled product thereof may leak to the side of the cell absorbing sheet 50. Is desirable. From the same viewpoint, the upper sheet 51 and the lower sheet 52 are extended to some extent outside the WD in the width direction from the cell 55 forming region, and the edge joint portion 54c is provided for reinforcement in this extending portion. preferable.

The difference in joint strength may be easily formed by changing the area of the joint portion 54, but is not limited to this. For example, when the joint portion 54 is formed by a hot melt adhesive, the hot melt adhesive is used. It is also possible to adopt a method of differentiating the type of the type depending on the part. In particular, when the joint portion 54 is formed by welding the upper sheet 51 and the lower sheet 52, the weak joint portion 54b can be formed only by making the joint portion 54 a dotted line and widening the point spacing 54D. Since the portion 54 is a portion that serves as a boundary between adjacent cells 55, if the point spacing 54D becomes too wide, there will be many gaps at the boundary between adjacent cells 55, and the highly absorbent polymer particles 53 will easily move. Therefore, when the wide and narrow width 54W of the joint portion 54 and the wide and narrow point spacing 54D are combined to form a dotted line weak joint portion 54b, the weak joint portion 54b portion is easily peeled off even though the gap is small. Become.

The dimensions of the joint portion 54 that joins the upper sheet 51 and the lower sheet 52 can be appropriately determined. For example, the width (the dimension in the direction orthogonal to the direction surrounding the cell 55 and equal to the distance between the cells 55) 54W is 1. It can be about 0 to 1.8 mm. Further, when the joint portion 54 is formed in a dotted line shape (intermittently in the direction surrounding the cell 55), the dimension 54L of the joint portion 54 in the direction surrounding the cell 55 is about 0.6 to 1.5 mm, and the point spacing 54D is 0. It is preferably about 8. to 3.0 mm. In particular, in the case of the strong joint portion 54a, the width 54W is about 1.3 to 1.8 mm, the size 54L of the joint portion 54 is about 1.0 to 1.5 mm, and the point spacing 54D is 0.8 to 2.0 mm. It is preferable to set the degree. In the case of the weak joint portion 54b, the width 54W is about 1.0 to 1.3 mm, the size 54L of the joint portion 54 is about 0.6 to 1.0 mm, and the point spacing 54D is about 1.5 to 3.0 mm. It is preferable to set the degree.

In order to make the weakly joined portion 54b peelable, the volume of the highly absorbent polymer particles 53 in the cell 55 at the time of saturated absorption is sufficiently larger than the volume of the cell 55 adjacent to the weakly joined portion 54b. The type and amount of the highly absorbent polymer particles 53 arranged in each cell 55 can be determined. Further, in order to prevent the strong joint portion 54a from being peeled off basically, the volume of the cell 55 that can be combined by peeling off the weak joint portion 54b after the combination is higher than the volume of the cell 55 that can be combined. The type and amount of the highly absorbent polymer particles 53 arranged in each cell 55 can be determined so that the volume of the polymer particles 53 at the time of saturated absorption becomes small.

The width of the joint portion 54 when the joint portion 54 is formed in a continuous linear shape and the width 54 W when the joint portion 54 is formed in a dotted line shape are constant in the direction surrounding the cell 55 and can be changed. .. Further, the shape of each joint 54 when the joint 54 is formed in a dotted line shape can be appropriately determined, and all of them may be the same, or different shapes may be used depending on the part. In particular, when the shape of each cell 55 is polygonal, it is preferable to provide a joint portion 54 at at least one of the intermediate position of each side and each vertex position. Further, in the case of the strong joint portion 54a, it is preferable to provide it at each vertex position, but in the case of the weak joint portion 54b, it is easier for the weak joint portion 54b to peel off if it is not provided at each vertex position, and the cells 55 are united. Is preferable because it proceeds smoothly.

As shown in FIGS. 8 and 11, in the intermediate region of the cell absorbing sheet 50 in the width direction WD, the vertical strong joint line 58 in which the strong joint portion 54a continues to the LD in the front-rear direction, and the low expansion cells adjacent to both sides thereof. It is preferable that the diffusibility improving portion 57 made of 55 s is provided. The low-expansion cell 55s of the diffusibility improving portion 57 has a smaller amount of the highly absorbent polymer particles 53 per unit area than the cells 55 adjacent to both sides of the diffusible improving portion 57, and the diffusibility improving portion The joint portion 54 between the cells 55 adjacent to both sides of the 57 is a weak joint portion 54b. In this case, as shown in FIG. 10, at the beginning of absorption of the excrement liquid, a wide groove having the diffusible improving portion 57 as the bottom is formed due to the difference in the amount of expansion between the diffusible improving portion 57 and the peripheral portion thereof. The groove promotes liquid diffusion. In this state, due to the expansion force of the highly absorbent polymer particles 53 in the cells 55 around the diffusivity improving portion 57, the weakly joined portion between the low expansion cells 55s of the diffusibility improving portion 57 and the cells 55 on both sides thereof. It continues until the 54b comes off, and even after the weak joint portion 54b comes off, the strong joint portion 54a does not come off. Therefore, although the width of the groove is narrowed, the groove having the strong joint portion 54a as the bottom remains and the diffusibility is maintained. That is, the width of the groove is wide at the initial stage of absorption when diffusion of a large amount of excrement is important, and after that, the low expansion cell 55s of the diffusibility improving portion 57 is also the surrounding cell 55 so as not to cause problems such as gel blocking. However, a groove remains due to the strong joint portion 54a, and the diffusivity improving action is maintained.

The amount of the highly absorbent polymer particles 53 contained in the low-expansion cell 55s is preferably 1/3 or less of the adjacent cells 55 in terms of weight ratio, and it is particularly preferable that the high-absorbent polymer particles 53 are not contained at all.

In FIGS. 8 and 11, the strong joint portion 54a and the weak joint portion 54e having a relatively high joint strength are represented by thick dotted lines, and the other weak joint portions 54b and 54f are represented by thin dotted lines, which are high. The cells 55 containing the absorbent polymer particles 53 (that is, the cells 55 excluding the low expansion cells 55s and the empty cells 56 described later) are shaded in FIG.

As shown in FIG. 8, the diffusibility improving portion 57 may be provided over the entire length of the cell absorbing sheet 50, and as shown in FIG. 11, the intermediate portion of the front-rear direction LD (particularly including the crotch portion, and before and after the crotch portion). It may be provided only in the range covering both sides). Further, as shown in FIGS. 8 and 11, the diffusibility improving unit 57 may be provided at one place in the center of the WD in the width direction, or may be provided at a plurality of places at intervals in the WD in the width direction, although not shown. it can.

When the cells 55 can be united over the entire front-rear LD of the cell absorption sheet 50, the gelled product of the highly absorbent polymer particles 53 expanded during absorption can be largely moved in the front-rear LD in the united cell 55. The gelled product may collect in a low place such as a crotch portion and deteriorate the wearing feeling. Therefore, as shown in FIG. 8, a plurality of lateral strong joint lines 59, which are portions where the strong joint portion 54a continues continuously or intermittently in the width direction WD or the diagonal direction, are provided at intervals in the front-rear direction LD. Is a preferred form. As a result, the strong bonding portion 54a, which basically does not peel off during absorption, can prevent the gelled product of the highly absorbent polymer particles 53 from moving in the anteroposterior direction LD, and can prevent the shape of the cell absorbing sheet 50 from collapsing. .. Of course, as shown in FIG. 11, it is possible to form a form that does not have such a laterally strong joint line 59.

In particular, as shown in FIG. 8, the vertical strong joining line 58, which is a portion where the strong joining portion 54a continues to the front-rear direction LD over the entire length of the cell absorbing sheet 50, is on the outermost side of the cell 55 in the width direction WD. It is provided on both sides of the width direction WD along the edge, and is also provided in the middle of these width direction WDs, and the lateral strong joint line 59 extends between the vertical strong joint lines 58 adjacent to the width direction WD. In the case of the portion continuing in the width direction WD or the diagonal direction as described above, the cell 55 does not coalesce in the maximum expansion section 55G or more surrounded by the strong joint portion 54a, so that the gelled product of the highly absorbent polymer particles 53 expanded during absorption is formed. It does not move out of the maximum expansion section 55G, and the shape of the cell absorbing sheet 50 can be effectively prevented from being deformed during absorption. Further, the vertical strong joint line 58, which is a portion where the strong joint portion 54a continues to the LD in the front-rear direction, improves the liquid diffusivity in the vertical direction, and the strong joint portion 54a is a portion which continues in the width direction WD or the diagonal direction. The wire 59 improves the liquid diffusivity in the lateral direction. For example, in the form shown in FIG. 8, assuming that urine is excreted at the position of reference numeral Z, the urine is diffused to the surroundings as shown in FIG. 53 absorbs. At this time, as shown in FIGS. 9 and 10, with respect to the cell 55 in which the expansion pressure of the highly absorbent polymer particles 53 inside was increased, the weakly joined portion 54b around the cell 55 could not withstand the expansion pressure and peeled off. Combines with the adjacent cell 55. This coalescence continues as long as the absorption and expansion of the highly absorbent polymer particles 53 can peel off the weakly bonded portion 54b, and can proceed to the cell 55 having the strongly bonded portion 54a around it.

The size, shape, and arrangement of the maximum expansion section 55G (that is, the arrangement of the strong joint portion 54a) can be appropriately determined, but if the maximum expansion section 55G is made too small, there is no point in providing the strong joint portion 54a, and the number of cells 55 At most, when the cells are elongated, the shape of the cells 55 after being combined becomes a shape that does not easily swell.

In the modes shown in FIGS. 8 to 10, vertical strong joint lines 58 are provided at the center and both sides of the cell absorption sheet 50 in the width direction, respectively, and the horizontal strong joint lines 59 are the central vertical strong joints. Between the wire 58 and the vertical strong joint wire 58 on both sides, each of them has a zigzag shape extending in the front-rear direction while repeatedly bending left and right. As a result, the substantially triangular maximum expansion section 55G having an apex at the position of the central vertical strong junction line 58 and the substantially triangular maximum expansion section 55G having vertices at the positions of the vertical strong junction lines 58 on both sides are formed. , It is repeatedly formed alternately in the front-back direction. When the lateral strong joint line 59 is formed in a zigzag shape in this way, the liquid diffusion in the lateral direction can be efficiently promoted with a small number of lateral strong joint lines 59, and the maximum expansion section 55G becomes a substantially triangular shape that easily swells. , The amount of increase in cell volume with respect to the number of cells 55 combined is also excellent, which is preferable.

It is also possible to use only the vertical strong joint line 58 without providing the low expansion cell 55s. In this case, since the strong joint portion 54a does not come off when the excrement liquid is absorbed, the diffusibility is improved by leaving a groove having the strong joint portion 54a as the bottom.

On the other hand, as shown in FIG. 8 and the like, an empty cell 56 having a smaller inclusion amount per unit area of the highly absorbent polymer particles 53 than other cells can be provided. In FIG. 11, the cells 55 containing the highly absorbent polymer particles 53 (that is, the cells 55 excluding the low expansion cells 55s and the empty cells 56 described later) are shaded. Of these, the region with the diagonal line pattern in FIG. 8 assumes the spraying region 53A of the highly absorbent polymer particles 53 at the time of manufacture, so that the peripheral cell 55 has a portion without the diagonal line pattern, but the cell When the highly absorbent polymer particles 53 are movable within the 55, the position of the highly absorbent polymer particles 53 in the cell 55 is not fixed in the product, and the cell 55 is similar to that in the other figures. Highly absorbent polymer particles 53 can be distributed throughout the inside. The amount of the highly absorbent polymer particles 53 contained in the empty cell 56 is preferably 1/2 or less of that of the other cells in terms of weight ratio, and it is particularly preferable not to include the particles at all. For example, since the front end and the rear end of the cell absorbing sheet 50 are formed by cutting into individual cell absorbing sheets 50 during manufacturing, if the highly absorbent polymer particles 53 are contained in this position, the blade of the cutting device The life may be shortened. Therefore, it is desirable that at least the cell 55 at the position where the front and rear ends of the cell absorbing sheet 50 pass is an empty cell 56. Further, by setting the cells 55 on both sides in the middle of the LD in the front-rear direction of the cell absorption sheet 50 to be empty cells 56, the portion concerned has less expansion even after absorption, and therefore the cell absorption sheet 50 has legs even after absorption. The shape fits around.

In the above example, only the highly absorbent polymer particles 53 are included in the cell 55, but powder particles other than the highly absorbent polymer particles such as deodorant particles can be included together with the highly absorbent polymer particles 53. ..

(Highly absorbent polymer particles)
As the highly absorbent polymer particles 53, those used for this kind of absorbent article can be used as they are. The particle size of the highly absorbent polymer particles 53 is not particularly limited, but for example, the proportion of particles larger than 500 μm is 30% by weight or less, the proportion of particles of 500 μm or less and more than 180 μm is 60% by weight or more, and more than 106 μm and 180 μm. It is preferable that the proportion of the following particles is 10% by weight or less and the proportion of particles of 106 μm or less is 10% by weight or less. The particle size is measured as follows. That is, standard sieves of 500 μm, 180 μm, and 106 μm (JIS Z8801-1: 2006) and saucers are arranged side by side in this order from the top, and 10 g of a sample of highly absorbent polymer particles is put into the uppermost 500 μm sieve. After sieving (shaking for 5 minutes), weigh the particles remaining on each sieve. As a result of this sieving, the weight ratio of the sample remaining on each of the 500 μm, 180 μm, and 106 μm sieves and the input amount of the sample remaining on the saucer was determined by the ratio of the particles exceeding 500 μm and the particles of 500 μm or less and 180 μm or more, respectively. The ratio shall be the ratio of particles exceeding 106 μm and 180 μm or less, and the ratio of particles of 106 μm or less.

The highly absorbent polymer particles 53 can be used without particular limitation, but those having a water absorption of 40 g / g or more are preferable. Further, it is preferable that the highly absorbent polymer particles 53 are produced by a crushing method because gel blocking is unlikely to occur. Examples of the highly absorbent polymer particles 53 include starch-based, cell 55-loin-based, and synthetic polymer-based ones, which are starch-acrylic acid (salt) graft copolymers, starch-acrylonitrile copolymers, and sodium carboxy. A crosslinked product of methyl cell 55 loin or an acrylic acid (salt) polymer can be used. As the shape of the highly absorbent polymer particles 53, a powder or granular material that is usually used is preferable, but other shapes can also be used.

As the highly absorbent polymer particles 53, those having a water absorption rate of 70 seconds or less, particularly 40 seconds or less, are preferably used. If the water absorption rate is too slow, so-called reversion, in which the liquid supplied into the absorber 70 returns to the outside of the absorber 70, is likely to occur.

Further, as the highly absorbent polymer particles 53, those having a gel strength of 1000 Pa or more are preferably used. As a result, the sticky feeling after liquid absorption can be effectively suppressed.

(Packaging sheet)
As shown in FIGS. 3 and 15 (a), the absorber 70 can be wrapped by the packaging sheet 45. In this case, one wrapping sheet 45 can be wrapped in a tubular shape so as to surround the front and back surfaces and both side surfaces of the absorber 70, and can be wrapped by being sandwiched between the two wrapping sheets 45 from both the front and back surfaces. As the packaging sheet 45, tissue paper, particularly crepe paper, non-woven fabric, non-woven fabric of polylami, a sheet having small holes, or the like can be used. However, it is desirable that the sheet does not allow the highly absorbent polymer particles 53 to come out. When a non-woven fabric is used for the packaging sheet 45, a hydrophilic SMS non-woven fabric (SMS, SMSMS, etc.) is particularly preferable, and polypropylene, polyethylene / polypropylene composite material, or the like can be used as the material thereof. The weight of the non-woven fabric used for the packaging sheet 45 is preferably 5 to 40 g / m ² , especially 10 to 30 g / m ² .

As shown in FIG. 15B, the packaging sheet 45 is wound from the back surface of the absorber 70 to both sides of the upper surface of the absorber 70 via both sides of the WD in the width direction of the absorber 70, and the width of the upper surface of the absorber 70. It is preferable to provide a region 45S not covered by the packaging sheet 45 in the middle portion of the direction WD. The absorber 70 is generally coated with a packaging sheet 45 in order to prevent leakage of highly absorbent polymer particles during production, before use, or after absorption. However, the absorber 70 absorbs a viscous liquid. Considering the property, it is desirable that the upper sheet 51 comes into contact with the viscous liquid N promptly. Therefore, as shown in FIG. 15B, it is desirable to limit the covering range of the packaging sheet 45 and expose the upper sheet 51 to the upper surface of the absorber 70. Even with such a structure, since the upper sheet 51 is based on a highly water-absorbent non-woven fabric having a high Krem water absorption (that is, dense), it is a highly absorbent polymer similar to that in which the entire absorber 70 is covered with the packaging sheet 45. It exerts the effect of preventing the leakage of particles.

<Explanation of terms in the specification>
When the following terms are used in the specification, they have the following meanings unless otherwise specified in the specification.

The "MD direction" and the "CD direction" mean the flow direction (MD direction) in the manufacturing equipment and the lateral direction (CD direction) orthogonal to the flow direction, and one of them is the front-rear direction of the product. The other is in the width direction of the product. The MD direction of the non-woven fabric is the direction of fiber orientation of the non-woven fabric. The fiber orientation is the direction along which the fibers of the non-woven fabric follow. For example, the measurement method according to the fiber orientation test method based on the zero-distance tensile strength of the TAPPI standard method T481 or the fibers based on the tensile strength ratio in the anteroposterior direction and the width direction. It can be discriminated by a simple measuring method for determining the orientation direction.

-The "front-back direction" means the direction indicated by the symbol LD in the figure (vertical direction), and the "width direction" means the direction indicated by the WD in the figure (horizontal direction), and the front-back direction and the width direction. Are orthogonal.

-The "front side" means the one closer to the wearer's skin when worn, and the "back side" means the one farther from the wearer's skin when worn.

-The "front surface" means the surface of the member that is closer to the wearer's skin when worn, and the "back surface" means the surface of the member that is farther from the wearer's skin when worn.

The "unfolded state" means a state in which the unfolded state is flat without shrinkage or slack.

The "elongation rate" means a value when the natural length is 100%. For example, an elongation rate of 200% is synonymous with an elongation ratio of 2 times.

"Artificial urine" includes urea: 2 wt%, sodium chloride: 0.8 wt%, calcium chloride dihydrate: 0.03 wt%, magnesium sulfate heptahydrate: 0.08 wt%, and ion-exchanged water: 97. It is a mixture of 09 wt% and is used at a temperature of 37 ° C. unless otherwise specified.

"Gel strength" is measured as follows. To 49.0 g of artificial urine, 1.0 g of a highly absorbent polymer is added and stirred with a stirrer. The produced gel is left in a constant temperature and humidity chamber at 40 ° C. × 60% RH for 3 hours, then returned to room temperature, and the gel strength is measured with a card meter (Curdmeter-MAX ME-500 manufactured by I. techno Engineering).

"Metsuke" is measured as follows. After pre-drying the sample or test piece, leave it in a test room or device under standard conditions (test location: temperature 23 ± 1 ° C., relative humidity 50 ± 2%) to bring it to a constant weight. Pre-drying refers to making a sample or test piece constant in an environment at a temperature of 100 ° C. It is not necessary to pre-dry the fibers having an official moisture content of 0.0%. A sample having a size of 100 mm × 100 mm is cut out from the test piece in a constant weight state using a sampling template (100 mm × 100 mm). The weight of the sample is measured and multiplied by 100 to calculate the weight per square meter, which is used as the basis weight.

The "thickness" is automatically measured using an automatic thickness measuring device (KES-G5 handy compression tester) under the conditions of ^{a load of 0.098 N / cm 2} and a pressurized area of 2 cm ^2.

The "porosity" is measured by the following method. That is, a portion of the middle sheet other than the joint is cut into a rectangle and used as a sample. Measure the length, width, thickness and weight of the sample. Using the raw material density of the non-woven fabric, the virtual weight is calculated when the volume is the same as the sample and the porosity is 0%. Substitute the sample weight and virtual weight into the following formula to obtain the porosity.
Porosity = [(Virtual weight-Sample weight) / Virtual weight] x 100

The "water absorption amount" is measured by JIS K7223-1996 "Water absorption amount test method for highly water-absorbent resin".

"Water absorption rate" is defined as "time to end point" when JIS K7224-1996 "Water absorption rate test method for highly water-absorbent resin" was performed using 2 g of highly absorbent polymer and 50 g of physiological saline. To do.

"Krem water absorption" means the Krem water absorption measured by "paper and paperboard-water absorption test method-Krem method" defined in JIS P 8141: 2004.

"Water retention" means what is measured by the following method. Prepare a test piece of 10 cm in the MD direction x 10 cm in the CD direction (area 100 cm ² ), and measure the weight before absorption. Next, after immersing the test piece in artificial urine for 5 seconds, lightly pinch one of the corners with the thumb and index finger (pick as lightly as possible without squeezing water), and the opposite corners are below. Hang it so that it faces the surface, leave it for 30 seconds, and drop the drops. After that, when measuring the "water retention amount under load", the test piece is placed on a stack of eight filter papers (length 150 mm x width 150 mm), and the length 100 mm x so that the load is applied to the entire upper surface of the test piece. A square columnar weight (weight 3 kg) having a bottom surface of 100 mm in width is placed, the weight is removed after 5 minutes, and the weight of the test piece after absorption is measured. When measuring the "water retention amount under no load", place the test piece on a stack of eight filter papers, do not put anything on it, and measure the weight of the test piece after absorption after 5 minutes. To do. Based on these measurement results, the values obtained by converting the difference between the weight after absorption and the weight before absorption ^{per 10 cm 2} area are defined as "water retention under load" and "water retention under no load".

Unless otherwise specified, the dimensions of each part mean the dimensions in the unfolded state, not in the natural length state.

Unless there is a description of the environmental conditions in the test or measurement, the test or measurement shall be performed in a test room or device under standard conditions (test location: temperature 23 ± 1 ° C, relative humidity 50 ± 2%). ..

The present invention can be used for all absorbent articles such as pants-type disposable diapers, pad-type disposable diapers, and sanitary napkins, in addition to tape-type disposable diapers as in the above example.

LD ... front-back direction, N ... viscous liquid, U ... non-viscous liquid, WD ... width direction, 11 ... liquid-impermeable sheet, 12 ... exterior non-woven fabric, 12T ... target sheet, 13 ... fastening tape, 13A ... locking part, 13B ... Tape body, 13C ... Tape mounting part, 30 ... Top sheet, 40 ... Intermediate sheet, 42 ... High water absorption non-woven fabric, 42a ... Pulp layer, 42b ... Support layer, 45 ... Packaging sheet, 50 ... Cell absorption sheet, 50c ... Concave, 50d ... Depth, 50p ... Convex, 51 ... Upper sheet, 52 ... Lower sheet, 53 ... Highly absorbent polymer particles, 54 ... Joint, 54a ... Strong joint, 54b ... Weak joint, 54c ... Edge joint, 55 ... cell, 55G ... maximum expansion section, 55s ... low expansion cell, 56 ... empty cell, 57 ... diffusivity improvement part, 58 ... vertical strong joint line, 59 ... horizontal strong joint line, 60 ... rising Gather, 62 ... Gather sheet, 70 ... Absorber, 80 ... Medium sheet.

Claims (7)

It comprises an absorber and a liquid permeable topsheet located on the front side of the absorber.
The absorber includes a cell in which the upper sheet and the lower sheet having liquid permeability, a cell in which the upper sheet and the lower sheet are not joined, and a cell surrounded by a joint portion between the upper sheet and the lower sheet, and the inside of the cell. Containing a cell absorbing sheet with granules containing highly absorbent polymer particles housed in
The upper sheet is a highly water-absorbent non-woven fabric having a Krem water absorption of 100 mm or more.
An absorbent article, characterized in that. The highly water-absorbent nonwoven fabric forming the upper sheet is a wet nonwoven fabric having a ^{basis weight of 25 to 50 g / m 2 containing 50% or more of pulp fibers or rayon fibers.}
The absorbent article according to claim 1. The wet non-woven fabric has a support layer containing long fibers of synthetic resin and a pulp layer located on the outermost side and composed of only pulp fibers.
The absorbent article according to claim 2. The cell absorbing sheet contains highly absorbent polymer particles adjacent to the back surface of the upper sheet.
The absorbent article according to any one of claims 1 to 3. A portion of the upper sheet located in each cell is extruded upward, and a pair of concave portions and convex portions are formed on the upper surface and the lower surface of the upper sheet.
The absorbent article according to any one of claims 1 to 4. A liquid impermeable sheet arranged on the back side of the absorber is provided.
The lower sheet is a highly water-absorbent non-woven fabric having a Krem water absorption of 50 mm or more, a water retention under load of 0.1 g or more, and a water retention under no load of 0.5 g or more.
The absorbent article according to any one of claims 1 to 5. A portion of the lower sheet located in each cell is extruded downward, and a pair of concave portions and convex portions are formed on the upper surface and the lower surface of the lower sheet.
The absorbent article according to claim 6.

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