JP6159636B2 - Absorbent articles - Google Patents

Description

  The present invention relates to absorbent articles such as paper diapers, sanitary napkins, incontinence pads, and the like, and more particularly, to absorbent articles excellent in excretory fluid absorbability.

For example, disposable paper diapers that absorb excretion fluid such as urine include a liquid-permeable sheet (so-called top sheet) located on the skin side of the wearer and a liquid-impermeable sheet (so-called back sheet) located on the clothes side. And an absorber provided between the liquid-permeable sheet and the liquid-impermeable sheet.
When such a paper diaper is actually worn, the absorbent body in the paper diaper is generally curved in a substantially U shape along the wearer's body and extends from the abdomen to the crotch and the buttocks. is there.

At this time, the crotch part, which is the part that mainly receives excretory fluid, is at the lowest position, while the abdominal part and the buttocks are higher than the crotch part. Therefore, if no measures are taken, when the excretory fluid is discharged to a paper diaper, the excretion fluid is absorbed and retained in the crotch, while the excretory fluid does not diffuse into the abdomen or buttocks. rare.
Therefore, only the crotch part is actually utilized in the absorbent body, and the other abdomen and buttocks are not utilized effectively, and the desired absorption / retention amount for the excretory fluid is not obtained. Is the actual situation.

  On the other hand, as described in Patent Document 1, for example, a liquid diffusion sheet in which excretory liquid that cannot be absorbed on the liquid-permeable sheet side of the absorber is disposed on the liquid-impermeable sheet side of the absorber. In addition, it is known that the excretory fluid absorbed by the liquid diffusion sheet is diffused to the liquid-impermeable sheet side of the absorber, and absorbed and held by the absorber from the liquid-impermeable sheet side. The technique described in Patent Document 1 uses the liquid-impermeable sheet side of an absorber that is difficult to use, thereby increasing the absorption region of the excretory fluid of the absorber, and increasing the absorption rate and retention amount of the excretory fluid. ing.

However, the thing of the said patent document 1, when an absorber may leave | separate from a diffusion sheet, especially when a wearer walks or stands or sits down, an absorber and a diffusion sheet are called, There was a drawback of separation.
Then, since the excretion liquid once absorbed by the liquid diffusion sheet cannot be moved well to the liquid impervious sheet side of the absorber and the amount of movement decreases, the excretion liquid diffused by the liquid diffusion sheet is absorbed by the absorber. It was in a situation that could not be absorbed enough.
In addition, when the excretory liquid retained by the liquid diffusion sheet cannot be sufficiently absorbed by the absorber, the liquid diffusion sheet is still discharged before the second discharge of the excretion liquid. It will be in the state holding liquid. Therefore, the liquid diffusion sheet cannot recover the function of absorbing and diffusing the excretory liquid again, resulting in the loss of the function of repeatedly diffusing the excretory liquid.
Therefore, only a part of the absorbent body is used for absorption / retention of excretory fluid, so that the desired absorption / retention amount cannot be obtained and the excretion fluid that could not be absorbed leaks. It was a situation.

JP 2008-284167 A

  The technical problem of the present invention is to provide an absorbent article capable of improving the absorption capacity of excretory liquid by effectively utilizing the entire absorbent body while ensuring the ability to repeatedly diffuse excretion liquid in the liquid diffusion sheet. There is.

  In order to solve the above problems, an absorbent article according to the present invention includes a liquid-permeable sheet, a liquid-impermeable sheet disposed on one side of the liquid-permeable sheet, and these liquid-permeable sheets and liquid-impermeable sheets. An absorbent article comprising an absorbent body disposed between a permeable sheet and the absorbent article formed by a nonwoven fabric containing cellulose fibers between the absorbent body and the liquid-impermeable sheet. A liquid diffusion sheet extending in the length direction of the body is disposed, and the thickness of the liquid diffusion sheet and the absorber in contact with the liquid diffusion sheet is embossed from the liquid-impermeable sheet side. A plurality of recesses that are formed by compressing in the direction and that the bottom side bites into the absorber are provided.

In the present invention, the liquid diffusion sheet may have a length in the width direction smaller than a minimum width portion in the width direction of the absorber.
Further, in the present invention, only the absorber is embossed from the liquid-impermeable sheet side at a position where the liquid diffusion sheet is not provided on the liquid-impermeable sheet side of the absorber, and the thickness direction A plurality of second recesses formed by compression into a plurality of portions may be provided.
Furthermore, in the present invention, the absorber includes pulp and a water-absorbing polymer, and the content of the water-absorbing polymer on the liquid-impermeable sheet side is higher than that on the liquid-permeable sheet side. it can.

Moreover, in this invention, it is preferable that the said liquid diffusion sheet is a wet spunlace nonwoven fabric.
Further, in the present invention, the liquid diffusion sheet extends in the length direction of the absorbent body provided at a constant interval on the absorbent body side of the base portion disposed on the liquid impervious sheet side, and the base portion. It has a plurality of ridges protruding to the absorber side, and a groove formed between adjacent ridges, the base has a higher fiber-occupied cross-sectional area ratio than the ridge, and the surface side region in the ridge is It is preferable that the fiber-occupied cross-sectional area ratio is higher than the area inside the surface side area.
Further, in the present invention, the liquid diffusion sheet has a liquid absorption height of 120 mm or more after 5 minutes of artificial urine and a water absorption ratio of 2.0 times or more in a water absorption test by the Krem method. can do.

According to the present invention, the bottom side formed by embossing the liquid diffusion sheet and the contact portion of the absorber with the liquid diffusion sheet from the liquid-impermeable sheet side and compressing in the thickness direction. Since there are provided a plurality of recesses that penetrate into the absorber, the adhesion between the absorber and the liquid diffusion sheet is extremely high as compared with the conventional case. Thereby, even if an absorber or a liquid diffusion sheet is twisted, the integrity is not impaired, and the excretory liquid absorbed by the liquid diffusion sheet can be smoothly absorbed from the liquid-impermeable sheet side of the absorber over a long period of time.
Therefore, the liquid diffusion sheet can maintain the ability to repeatedly absorb and diffuse the excretory fluid for a long period of time, so that the excretory fluid can be efficiently diffused throughout the absorber, and the entire absorber can be effectively utilized. Thus, the ability of absorbing the excretory fluid as the entire absorbent article can be improved.

FIG. 1 is a partially broken bottom view schematically showing a first embodiment of an absorbent article according to the present invention. FIG. 2 is an end view taken along the line A-A 'of FIG. FIG. 3 is an enlarged end view of the main part of FIG. FIG. 4 is a plan view schematically showing an example of an emboss pattern used for embossing. FIG. 5 is a diagram for explaining the movement of excretory fluid in the absorbent body according to the present invention. FIG. 6 is a partially broken bottom view schematically showing a second embodiment of the absorbent article according to the present invention. FIG. 7 is an enlarged end view of the main part of FIG. FIG. 8 is an enlarged end view of a main part at the same position as FIG. 3 schematically showing a third embodiment of the absorbent article according to the present invention. FIG. 9 is a view for explaining the content volume of the water-absorbing polymer in the absorbent body. However, (a) is a figure which shows typically the case where the content rate of the water absorbing polymer contained in the 1st layer is the highest, (b) is a water absorbing polymer in the 1st layer and the 2nd layer. It is a figure which shows typically the case where the ratio contained is high. FIG. 10 is a photograph showing a cross-sectional tomogram in the thickness direction of the absorber shown in FIG. 9B. FIG. 11 is an enlarged end view of a main part at the same position as FIG. 3 schematically showing a fourth embodiment of the absorbent article according to the present invention. 12 is an enlarged perspective view of a main part schematically showing the liquid diffusion sheet in FIG. 13 is a cross-sectional view taken along the line B-B 'of FIG. FIG. 14 is an explanatory view schematically showing a state in which steam jet treatment is performed in manufacturing the liquid diffusion sheet in the fourth embodiment of the absorbent article according to the present invention. FIG. 15 is a view for explaining the principle of forming the surface side region and the inner region of the buttock by the steam jet process. FIG. 16 is a cross-sectional view schematically showing a liquid diffusion sheet having a configuration different from the liquid diffusion sheets of FIGS. FIG. 17 is a cross-sectional view schematically showing a liquid diffusion sheet having a configuration different from that shown in FIG.

1 to 5 show a first embodiment of an absorbent article of the present invention. An absorbent article 1A according to the first embodiment includes a liquid-permeable sheet 2 and the liquid-permeable sheet. A liquid-impermeable sheet 3 disposed on one side of the sheet 2, and an absorbent body 4 disposed between the liquid-permeable sheet 2 and the liquid-impermeable sheet 3 and extending in one direction. I have.
Further, a liquid diffusion sheet 5 extending in the length direction of the absorber 4 is disposed between the absorber 4 and the liquid impermeable sheet 3.
In addition, what is shown in FIG. 1 is a disposable paper diaper as the absorbent article 1A, and the surface of the liquid impermeable sheet 3 on the side opposite to the absorbent side extends from the wearer's abdomen to the crotch and the buttocks. It is bonded to the covering chassis member with a hot melt adhesive (not shown).

The absorber 4 absorbs and retains excretory fluid such as urine of the wearer, includes pulp and a water-absorbing polymer, and has an outer peripheral surface covered with the coating sheet 7 together with the liquid diffusion sheet 5.
The absorbent body 4 and the cover sheet 7 are bonded to each other by a hot melt adhesive 8 interposed between the absorbent body 4 and the cover sheet 7. In addition, as an application | coating method of an adhesive agent, spiral coating, coater coating, curtain coater coating, summit gun coating etc. can be used, for example.
Further, the absorbent body 4 has a shape in which a longitudinal portion is curved toward the inner side of the absorbent body 4 so as to easily fit the crotch portion of the wearer.

In the first embodiment, the absorbent body 4 is blended so that the pulp and the water-absorbing polymer are contained almost uniformly without any unevenness throughout the absorbent body.
In the present invention, the pulp that forms the absorber 4 is, for example, wood pulp obtained from coniferous or hardwood (for example, mechanical pulp such as groundwood pulp, refiner ground pulp, thermomechanical pulp, chemithermomechanical pulp; craft; Pulp, sulfide pulp, chemical pulp such as alkali pulp; semi-chemical pulp, etc.); mercerized pulp or crosslinked pulp obtained by chemically treating wood pulp; bagasse, kenaf, bamboo, hemp, cotton (for example, cotton linter), etc. Non-wood pulp and the like.

  In the present invention, examples of the water-absorbing polymer forming the absorber 4 include starch-based, cellulose-based, and synthetic polymer-based highly water-absorbing materials. Examples of the starch-based or cellulose-based superabsorbent material include starch-acrylic acid (salt) graft copolymer, saponified starch-acrylonitrile copolymer, and a crosslinked product of sodium carboxymethyl cellulose. Synthetic polymer-based superabsorbent materials include, for example, polyacrylates, polysulfonates, maleic anhydrides, polyacrylamides, polyvinyl alcohols, polyethylene oxides, polyaspartates, polyglutamic acids Examples thereof include superabsorbent polymers (SAP) such as salt-based, polyalginate-based, starch-based, and cellulose-based materials. Among these, polyacrylate-based (particularly sodium polyacrylate-based) high A water absorbent resin is preferred.

  In the present invention, the covering sheet 7 is not particularly limited as long as it has liquid permeability and absorber retention, but from the viewpoint of low cost and absorber retention, it is formed by a wet method using pulverized pulp as a main material. The tissue to be used is preferred.

The liquid permeable sheet 2 is in contact with the skin surface of the wearer and quickly absorbs the excretion fluid of the wearer and transfers it to the absorbent body 4. A nonwoven fabric, a woven fabric, and a liquid permeation hole are formed. It is formed of a synthetic resin film, a net-like sheet having a mesh, and the like, and is disposed on the surface side of the absorbent body 4 facing the wearer's skin surface (the upper surface side of the absorbent body 4 in FIGS. 2 and 3). Yes. In this embodiment, the liquid permeable sheet 2 is bonded to the absorber 4 with the hot melt adhesive 15 applied by various coating methods such as spiral coating through the covering sheet 7. ing.
Examples of the nonwoven fabric used for the liquid permeable sheet 2 include natural fibers (for example, wool, cotton, etc.), regenerated fibers (for example, rayon, acetate, etc.), inorganic fibers (for example, glass fibers, carbon fibers, etc.), synthetic resin fibers (for example, Polyolefins such as polyethylene, polypropylene, polybutylene, ethylene-vinyl acetate copolymer, ethylene-ethyl acrylate copolymer, ethylene-acrylic acid copolymer, ionomer resin; polyethylene terephthalate, polybutylene terephthalate, polytrimethylene terephthalate And polyester such as polylactic acid; polyamide such as nylon). Non-woven fabrics include core / sheath fibers, side-by-side fibers, island / sea fibers, etc .; hollow fibers, flat fibers, Y-shaped fibers, C-shaped fibers, etc., latent crimps or manifestations Crimped three-dimensional crimped fibers; split fibers that are split by a physical load such as water flow, heat, and embossing may be mixed.

The liquid-impermeable sheet 3 is a surface of the absorber 4 opposite to the surface on which the liquid-permeable sheet 2 is disposed (on the wearer's clothes side. In FIG. 2 and FIG. It is provided on the lower surface side, and prevents the discharged excretory fluid from permeating and preventing it from leaking outside. In this embodiment, the liquid-impermeable sheet 3 is attached to the absorbent body 4 by the hot-melt adhesive 16 applied by various coating methods such as spiral coating through the covering sheet 7. It is glued.
Examples of the liquid-impermeable sheet 3 include a waterproof nonwoven fabric, a synthetic resin (eg, polyethylene, polypropylene, polyethylene terephthalate, etc.) film, a composite sheet of a nonwoven fabric and a synthetic resin film (eg, spunbond, spunlace, etc.). Composite film in which a breathable synthetic resin film is bonded to a non-woven fabric), an SMS non-woven fabric in which a melt-blown non-woven fabric having high water resistance is sandwiched between strong spunbond non-woven fabrics, and the like can be used.

On the other hand, the liquid diffusion sheet 5 moves and diffuses excretory fluid that has moved to the liquid-impermeable sheet side of the absorber 4 to the abdomen side and buttocks side of the absorber 4 to be absorbed by the absorber 4. The lengths in the length direction are substantially the same as the length of the absorber 4 and the length in the width direction is smaller than the minimum width portion of the absorber 4 in the width direction. It is a flat strip.
The liquid diffusion sheet 5 is disposed in the central portion of the absorbent body 4 in the width direction, the absorbent-side surface is in contact with the absorbent body 4 via a hot melt adhesive, and as described above. The coated sheet 7 is coated together with the absorbent body 4. The liquid diffusion sheet 5 has a surface opposite to the surface in contact with the absorber 4 by a hot melt adhesive 9 applied by various coating methods such as spiral coating, and the covering sheet 7. It is glued to.

  Here, as the liquid diffusion sheet 5 in the present invention, a nonwoven fabric containing cellulose fiber as a main raw material and other beaten pulp is used, and a wet spunlace nonwoven fabric is particularly suitable. In this case, it is preferable that the beaten pulp is fibrillated. In the present invention, “fibrillation” means that a microfiber portion having a submicron size fiber diameter is partially peeled from the surface of the fiber main body portion and extends from the surface of the fiber main body portion. means.

In the present invention, the cellulose fiber contained in the liquid diffusion sheet 5 is not particularly limited, and examples thereof include natural cellulose, regenerated cellulose, and semisynthetic cellulose.
Examples of the natural cellulose include pulp, for example, wood pulp obtained from coniferous or hardwood (for example, mechanical pulp such as groundwood pulp, refiner ground pulp, thermomechanical pulp, chemithermomechanical pulp; kraft pulp, sulfide pulp, alkali Chemical pulp such as pulp; semi-chemical pulp); mercerized pulp or crosslinked pulp obtained by chemically treating wood pulp; non-wood pulp such as bagasse, kenaf, bamboo, hemp, cotton (for example, cotton linter) Can be mentioned.
Examples of the regenerated cellulose include rayon, for example, viscose rayon obtained from viscose, polynosic and modal, copper ammonia rayon obtained from a copper ammonia salt solution of cellulose (also referred to as “cupra”); organic compound and water Examples thereof include lyocell and tencel obtained by an organic solvent spinning method using an organic solvent which is a mixed solution, and without passing through a cellulose derivative.
Examples of semisynthetic cellulose include acetate fibers such as triacetate and diacetate.
Moreover, when using pulp as these natural celluloses and rayon as regenerated cellulose, the mixing ratio of these pulps and rayon is preferably 10-70 parts by mass of rayon, and more preferably 15-65 parts by mass. It is preferable to do. Moreover, it is preferable to contain the said cellulose fiber and beaten pulp in the ratio of 60-90 mass parts and 10-40 mass parts, More preferably, the ratio (however, 65-75 mass parts and 25-35 mass parts) The total of cellulose fiber and beaten pulp does not exceed 100 parts by mass.).

Further, the liquid diffusion sheet 5 has a density of about 50 to 280 mg / cm ³ , and preferably has a density of 60 to 200 mg / cm ³ .
By setting the density of the liquid diffusion sheet 5 within this range, it is possible to form a capillary suitable for diffusing excretion fluid absorbed between the fibers in the liquid diffusion sheet. Thereby, in the liquid diffusion sheet, the capillary movement of the excretory liquid is more effectively performed, and the liquid diffusibility is further enhanced.
On the other hand, if the density exceeds 280 mg / cm ³ , the voids in the liquid diffusion sheet become too small and it becomes difficult to form capillaries, resulting in a decrease in liquid diffusibility. On the other hand, when the density is less than 50 mg / cm ³ , the voids in the liquid diffusion sheet increase, but the capillary phenomenon hardly occurs, so that the excretory fluid moves slowly and the liquid diffusibility also decreases.

Further, the liquid diffusion sheet 5 preferably has a liquid absorption height after 5 minutes of artificial urine of 120 mm or more, more preferably 130 mm or more, and further preferably 145 mm or more in a water absorption test by the Krem method. is there. Furthermore, the water absorption ratio is preferably 2.0 times or more, more preferably 2.4 times or more, and still more preferably 2.6 times or more.
If the liquid absorption height is too small, the absorber cannot be efficiently wetted. If the water absorption ratio is too small, the liquid cannot be efficiently transferred to the pulp / superabsorbent polymer forming the absorbent core.
The water absorption test by the Krem method is performed according to JIS P 8141: 2004.

Normally, paper is manufactured through processes such as papermaking (including heat-fusible fibers and binders), drying, and thermocompression bonding as required. Therefore, the paper has a uniform cross-sectional structure. As the diameter increases, the capillary diameter increases, the suction height decreases, and the suction amount increases.
However, when the liquid diffusion sheet 5 is made of a wet spunlace nonwoven fabric, the wet spunlace nonwoven fabric is subjected to papermaking, water jet, and a drying process so that a sparse part having a low density and a dense part having a high part are formed. It has a sparse / dense structure (the entangled part due to hydroentanglement becomes dense). In the subsequent drying step, the bulk of the nonwoven fabric is raised to form a sparse portion depending on the bulk state other than the hydroentangled portion.
Therefore, in the liquid diffusion sheet 5 using the wet spunlace nonwoven fabric, since the density structure is already formed, if the density between the sparse entangled portions is reduced, the suction amount increases and the density is increased. It is considered that a certain entangled part is supplied with liquid from between the entangled parts, and the suction height becomes larger.

By the way, the liquid diffusion sheet 5 and the absorber 4 are embossed from the liquid-impermeable sheet side at the contact portion of the liquid diffusion sheet 5 and the absorber 4 with the liquid diffusion sheet 5. . The liquid diffusion sheet 5 and the bottom portion formed by compressing in the thickness direction by this embossing on the liquid-impermeable sheet side of the abutting portion of the absorber 4 with the liquid diffusion sheet 5 A plurality of recesses 10 on the side of 10 a that penetrates to the absorber 4 and a protrusion 11 that is formed between these recesses 10 and that protrudes toward the liquid-impermeable sheet are provided.
In this embodiment, the liquid diffusion sheet 5 and the part other than the contact part of the absorber 4 with the liquid diffusion sheet 5, that is, the liquid diffusion sheet on the liquid impermeable sheet side of the absorber 4. The concave portion 10 does not exist in a portion where 5 does not exist.

As described above, the liquid diffusion sheet 5 and the absorber 4 are embossed from the liquid-impermeable sheet side in the liquid diffusion sheet 5 and the abutting portion of the absorber 4 with the liquid diffusion sheet 5. This is to prevent the mutual separation from each other and to stably move the excretory fluid between the two.
That is, for example, when an absorbent article such as a diaper is worn, if the wearer performs an operation such as walking, standing, or sitting, the absorbent body and the liquid diffusion sheet may be deformed by being twisted or bent. If no measures are taken at this time, the absorber and the liquid diffusion sheet are likely to be separated from each other. In addition, it is conceivable that the absorbent body and the liquid diffusion sheet are bonded to each other with a hot-melt type adhesive. The liquid diffusion sheet may be separated from each other.

Then, since the excretory liquid once absorbed by the liquid diffusion sheet cannot be moved to the liquid-impermeable sheet side of the absorber, the excretion liquid retained and diffused by the liquid diffusion sheet can be sufficiently absorbed by the absorber. The situation is impossible.
In addition, when the excretion liquid of the liquid diffusion sheet cannot be absorbed by the absorber, the liquid diffusion sheet is still in a state of holding the discharged liquid, so that the liquid diffusion function is substantially lost. The excretory fluid cannot be absorbed and diffused again.
Therefore, in a state where the liquid diffusion function of the liquid diffusion sheet is lost, the entire absorbent body cannot be used for absorption / retention of excretion liquid, so a desired absorption / retention amount as an absorbent article cannot be obtained, When the amount of excretory fluid is large, or when the excretory fluid is discharged for the second time or later, there is a possibility that the excreted fluid may not be absorbed and leakage may occur.

  Therefore, in the present invention, the liquid diffusion sheet 5 and the abutting portion of the absorber 4 with the liquid diffusion sheet 5 are embossed from the liquid-impermeable sheet side to form the recesses 10. The adhesion between the liquid diffusion sheet 5 and the absorber 4 is enhanced, and both are prevented from separating from each other. Furthermore, since the recessed area 10 is formed by embossing, the contact area between the liquid diffusion sheet 5 and the absorber 4 is substantially increased. Therefore, the excretory liquid between the liquid diffusion sheet 5 and the absorber 4 Can be effectively and stably performed.

  The concave portion 10 is embossed at the contact portion between the liquid diffusion sheet 5 and the absorbent body 4 and compressed in the thickness direction so that the bottom portion 10a side bites into the absorbent body 4. This is to control the moving speed of the excretory fluid that moves inside.

Specifically, in order to improve the absorption capacity of the absorbent article as a whole, in the range where the liquid diffusion sheet in the absorbent body is in contact, the movement speed of the excretory liquid is increased as much as possible to perform rapid diffusion. The liquid diffusion function of the liquid diffusion sheet is reduced by absorbing the excretion liquid in a portion where the absorption capacity of the excretion liquid in the absorber is sufficient and reducing the excretion liquid held by the liquid diffusion sheet by the absorption. It is important to restore
On the other hand, except for the range where the liquid diffusion sheet is in contact with the absorbent body, from the viewpoint of liquid leakage suppression, the movement speed of the excretory liquid is reduced as much as possible to prevent leakage of the excreted liquid from the absorbent body. There is a need.

  Here, the movement of the excretory fluid in the absorbent body will be described. In the absorbent body, basically, the excretory fluid moves by capillary action in a portion where the density is high. On the other hand, since the capillary phenomenon does not occur in the portion where the density is low, the excretion fluid is retained, but the movement speed of the excretion fluid is slower than that of the high density portion and is difficult to diffuse.

In this embodiment, the liquid-impervious sheet side of the absorbent body 4 includes the concave portion 10 and the convex portion 11 formed at the contact portion between the absorbent body 4 and the liquid diffusion sheet 5, and the absorbent body 4. There are three regions of the surface portion of the absorbent body 4 in a portion other than the contact portion with the liquid diffusion sheet 5, that is, a portion where the liquid diffusion sheet 5 does not exist. In addition, the surface part of the absorber 4 in the part where the diffusion sheet 5 does not exist is less affected by the compression by embossing than the convex part 10 and the concave part 11.
Then, since the recess 10 is formed by being greatly compressed in the thickness direction of the liquid diffusion sheet 5 and the absorber 4 by embossing, the bottom 10a of the recess 10 in the absorber 4 and the absorber 4 are formed. The distance L _{1 to} the liquid diffusion sheet side is short, and the density of this region is the highest among the absorbers 4.
Further, since the liquid diffusion sheet 5 is in contact with the convex portion 11, compared with a portion where the diffusion sheet 5 does not exist, an extra compression is applied by the thickness of the liquid diffusion sheet 5 during embossing. . Therefore, the distance L ₂ between the tip and the liquid diffusion sheet side of the absorbent body 4 in the convex portion 11 is longer than the distance L ₁ on the bottom 10 a side of the concave portion 10, the compression amount is small, and the density is small. Is also low. On the other hand, the distance L ₂ is shorter than the distance L ₃ between the surface portion and the liquid diffusion sheet side of the absorber 4 as compared with the region of the surface portion of the absorber in the portion where the diffusion sheet 5 does not exist. Therefore, the area of the convex portion 11 has a larger compression amount and a higher density.
Therefore, since the density in the absorbent body 4 is the largest in the concave portion 10, and then in the order of the convex portion 11 and the portion where the liquid diffusion sheet does not exist, the movement speed of the excretory fluid in the absorbent body 4 is The portion of the concave portion 10 is the earliest, followed by the convex portion 11 and the portion where the liquid diffusion sheet does not exist.

At this time, the convex portion 11 and the concave portion 10 are formed only in the contact portion of the liquid diffusion sheet 5 in the absorbent body 4, that is, in the range of the liquid diffusion sheet 5. 4 is disposed at the center portion in the width direction, and the length in the width direction is set to be smaller than the minimum width portion in the width direction of the absorber 4. In the vicinity, the diffusion sheet 5 does not exist, and the surface portion of the absorber 4 appears.
Therefore, on the liquid impervious sheet side of the absorbent body 4, the excretory liquid can be quickly moved in the part where the liquid diffusion sheet 5 is in contact with the absorbent body 4, particularly in the part where the recess 10 is formed. On the other hand, in the part where the liquid diffusion sheet 5 does not exist, the movement speed of the excretory liquid can be reduced.

Thereby, since the movement speed of the excretion liquid in the absorber 4 can be controlled, the movement speed of the excretion liquid is improved in the range where the liquid diffusion sheet 5 is in contact with the absorbent body 4, and the length direction is reduced. So that diffusion can be done quickly.
On the other hand, in the range where the liquid diffusion sheet 5 does not exist in the absorbent body 4, that is, in the both ends in the width direction of the absorbent body 4 and the vicinity thereof, the movement speed of excretory liquid is reduced to suppress diffusion. The liquid leakage in the width direction can be suppressed.
Therefore, there is no problem even if the length in the width direction is set to be smaller than the minimum width portion in the width direction of the absorber 4 as in the liquid diffusion sheet 5 of this embodiment, and liquid leakage is suppressed. However, the liquid diffusion function can be sufficiently exhibited, and the material of the liquid diffusion sheet can be reduced.

When performing the embossing, the liquid diffusion sheet 5 is brought into contact with the liquid-impermeable sheet side of the absorbent body 4 in advance, and both the absorbent body 4 and the liquid diffusion sheet 5 are covered with the covering sheet 7. Keep it covered. Then, the liquid diffusion sheet 5 was brought into contact between an embossing roll in which an embossing pattern having a width substantially equal to the width of the liquid diffusion sheet 5 was formed on the peripheral surface and a flat roll having a flat peripheral surface. By passing the absorbent body 4, embossing along the embossed pattern is formed at the liquid diffusion sheet 5 and the contact portion of the absorbent body 4 with the liquid diffusion sheet 5.
The embossing pattern in the present invention is not particularly limited. For example, as shown in FIG. 4, a plan view lattice shape (at the time of embossing, a substantially rectangular frame-shaped part is a concave part, and a part surrounded by the concave part is The embossed pattern can be a convex portion. In addition, although a dot-like pattern etc. can be used, it is preferable that it is a pattern extended in the length direction of an absorber, such as a pattern in which several broken lines extended in the length direction of an absorber are arranged.

The movement of the excretory fluid when the absorbent article 1A having the above configuration is worn will be described (see FIG. 5, where the arrow in FIG. 5 indicates the direction of excretory fluid movement).
First, when the excretion liquid is discharged from the wearer, the excretion liquid passes through the liquid permeable sheet 2 and moves to the absorber 4.
The excretory fluid that has moved to the absorber 4 is diffused along the covering sheet 7, while moving to the surface of the absorber 4 through the covering sheet 7. The excretory fluid that has moved to the surface of the absorbent body 4 moves along the surface of the absorbent body 4, but also moves to the interfiber spaces of the pulp of the absorbent body 4, and absorption by the water-absorbing polymer starts. Is done. At this time, although it is diffused to some extent due to the influence of the covering sheet 7, most of the excreted liquid is mostly abdomen 4 a of the absorbent body 4 (left side of the absorbent body in FIG. 5) and crotch section 4 b (almost of the absorbent body). It stays in the region of the crotch portion 4b in the center portion) and the heel portion 4c (on the right side of the absorbent body in FIG. 5) and begins to be absorbed.
In the case of the first absorption of the excreted liquid, since it takes time for the water-absorbing polymer to begin to expand due to wetting, it passes through the absorber 4 by gravity while moving through the pulp having a higher expansion speed. ) To reach the liquid diffusion sheet 5. In the second and subsequent excretion of the excretory fluid, the water-absorbing polymer swells and the density of the absorber 4 in that portion decreases, so that the excretory fluid is not absorbed and passes through the absorber 4 and the liquid diffusion sheet 5. To reach.

  The excretory fluid that has reached the liquid diffusion sheet 5 moves through the interface between the absorber 4 and the liquid diffusion sheet 5 and is absorbed by the liquid diffusion sheet 5. Then, the excretory liquid absorbed by the liquid diffusion sheet 5 starts to move through the liquid diffusion sheet 5 by capillary action, and is absorbed in the length direction that is the abdomen side and the buttock side of the liquid diffusion sheet 5 regardless of gravity, that is, absorbed. It gradually moves and diffuses to the buttocks side and the abdomen side of the body 4. Further, the excretory fluid moves and diffuses in the width direction of the absorbent body 4, that is, in the direction of the wearer's crotch by the liquid diffusion sheet 5.

About the length direction of the said absorber 4, since the excretion fluid from a wearer is not excreted directly in the abdominal part side and the buttocks side of this absorber 4, there is still allowance for the absorption amount of excretion fluid. In particular, the liquid-impermeable sheet side of the absorbent body 4 is hardly used for the absorption of excretory liquid at this point. Therefore, the excretory liquid diffused in the length direction of the liquid diffusion sheet 4 is absorbed by the absorbent body 4 on the abdomen side and the buttock side.
Thereby, excretory fluid can be efficiently absorbed by effectively utilizing the abdomen side and the buttocks side of the absorber 4 that has hardly been used conventionally.

Furthermore, the liquid diffusion sheet 5 in which the excretory fluid is absorbed on the abdomen side or the buttock side of the absorbent body 4 recovers the ability to absorb and retain and diffuse the excretion fluid again, as much as the retained excretion fluid is lost. Therefore, the excretory liquid retained by the crotch portion of the liquid diffusion sheet 5 is continuously diffused and sequentially absorbed on the abdomen side and the buttocks side of the absorber 4.
Therefore, as long as the diffused excretory fluid is absorbed from the abdomen side or the buttock side of the absorbent body 4, the liquid diffusion sheet 5 continues to recover the liquid diffusing ability, and thus the excretory fluid can be diffused repeatedly.
As a result, even if the wearer discharges the excretion liquid a plurality of times, the liquid diffusion sheet 5 whose liquid diffusing ability has been recovered stably diffuses the excretion liquid each time, so that the excretion liquid is reliably transferred to the absorber 4. It can be absorbed and retained.

On the other hand, with respect to the width direction of the absorbent body 4, the liquid diffusion sheet 5 and the abutting portion of the absorbent body 4 with the liquid diffusion sheet 5 are embossed from the liquid-impermeable sheet side to form the concave portion 10 and the convex portion. Since the part 11 is formed, the moving speed of the excretory fluid in the width direction of the absorber 4 is controlled.
That is, the liquid diffusion sheet 5 can rapidly move the excretory fluid by capillary action, particularly on the bottom 10a side of the recess 10 where the density of the absorber 4 is high. Can diffuse in the direction. Furthermore, the excretory fluid that has moved from the other concave portions 10 and convex portions 11 along with the diffusion can be diffused early in the length direction.
Further, the portion where the liquid diffusion sheet 5 does not exist in the absorber 4 has a lower density than the portion where the liquid diffusion sheet 5 is in contact, and the movement speed of the excretory liquid is slowed down, so that diffusion is suppressed. Liquid leakage is suppressed.

As described above, according to the absorbent article 1A having the above-described configuration, the liquid diffusion sheet 5 and the abutting portion of the absorbent body 4 with the liquid diffusion sheet 5 are embossed from the liquid-impermeable sheet side. Since the plurality of recesses 10 that are formed by compressing in the thickness direction and the bottom 10a side bites into the absorber 4 are provided, the adhesiveness between the absorber 4 and the liquid diffusion sheet 5 compared to the conventional case. Is extremely high.
And since the contact area of the said absorber 4 and the liquid diffusion sheet 5 expands substantially by forming the several recessed part 10 by embossing, between these absorbers 4 and the liquid diffusion sheet 5 between them. The excretory fluid can be moved more efficiently.

  Further, the concave portion 10 is formed by embossing the liquid diffusion sheet 5 and a contact portion of the absorber 4 with the liquid diffusion sheet 5 and compressing in the thickness direction, and the bottom 10a side absorbs the concave portion 10. Since the body 4 has been cut in, the density of the absorber 4 on the bottom 10a side of the recess 10 is particularly higher than that of other parts. Thereby, the movement speed of excretion liquid increases by capillary action, and the quick spreading | diffusion to the length direction and the width direction of the absorber 4 is attained.

Therefore, even if the absorbent body 4 or the liquid diffusion sheet 5 is moved by the wearer's walking or the like, mutual integrity is not impaired, and excretory liquid absorbed by the liquid diffusion sheet 5 is absorbed into the absorbent body 4. It can be moved and absorbed stably and smoothly over a long period of time.
As a result, the liquid diffusion sheet 5 can maintain the ability to repeatedly absorb and diffuse the excretory liquid for a long period of time and stably diffuse the excretory liquid throughout the absorber, It becomes possible to improve the absorption capacity of the excretory fluid as the whole absorbent article by effectively utilizing the whole absorbent body.
Furthermore, since the excretory fluid diffuses throughout the absorbent body, problems such as liquid leakage and skin wetness can be solved, and the crotch portion of the absorbent body 4 can be prevented from partially and excessively expanding, so that the feeling of wear is also good. It is.

  In the first embodiment, the concave portion 10 is formed by embossing the liquid diffusion sheet 5 and the portion of the absorber 4 that contacts the liquid diffusion sheet 6 from the liquid-impermeable sheet side. However, in the second embodiment described below, embossing is also applied to the position where the liquid diffusion sheet is not disposed on the liquid-impermeable sheet side of the absorber.

  That is, FIG.6 and FIG.7 shows 2nd Embodiment of the absorbent article which concerns on this invention, Absorbent article 1B of this 2nd Embodiment is liquid-permeable sheet 2, and this A liquid-impermeable sheet 3 disposed on one surface side of the liquid-permeable sheet 2, and an absorber 4 disposed between the liquid-permeable sheet 2 and the liquid-impermeable sheet 3. Yes. Between the absorbent body 4 and the liquid-impermeable sheet 3, a liquid diffusion sheet 5 that is formed of a nonwoven fabric containing cellulose fibers and extends in the length direction of the absorbent body 4 is disposed.

In addition, the liquid diffusion sheet 5 and the portion of the absorber 4 that contacts the liquid diffusion sheet 5 are formed by embossing from the liquid-impermeable sheet side and compressing in the thickness direction. There are provided a plurality of first recesses 10 where the bottom 10a side penetrates to the absorber, and a first projection 11 formed between these recesses 10 and protruding toward the liquid-impermeable sheet.
In addition, about this 1st recessed part 10 and the 1st convex part 11, since it is a structure substantially the same as the recessed part and convex part of 1st Embodiment, and there exists the same effect, The same reference numerals are given and detailed description is omitted.

  Further, only the absorbent body 4 (strictly, the absorbent body 4 and the covering sheet 7) are liquid-impermeable at a position where the liquid diffusion sheet 5 is not disposed on the liquid-impermeable sheet side of the absorbent body 4. A plurality of second recesses 20 formed by embossing from the conductive sheet side and compressing in the thickness direction, and projecting to the liquid-impermeable sheet side formed between these second recesses 20 A plurality of second convex portions 21 are provided.

Thus, the second recess 20 was formed by embossing from the liquid-impermeable sheet side and compressing in the thickness direction in a range where the absorbent body 4 is not in contact with the liquid diffusion sheet 5. This is because the movement speed of the excretory fluid moving in the absorbent body can be improved at a position other than the contact portion with the liquid diffusion sheet 5, and the excretory fluid can be quickly moved and diffused.
That is, the excretion liquid is moved and diffused as quickly as possible in the length direction and the width direction of the absorber at a position other than the contact portion with the liquid diffusion sheet 5 in the absorbent body 4, so that the entire absorption body of the excretion liquid By making it possible to make more effective use of absorption, the absorption capacity is improved.

Here, since the second recess 20 is formed by being compressed by embossing in the thickness direction of the absorbent body 4, the bottom 20 a of the second recess 20 in the absorbent body 4 and the liquid permeable sheet. The distance L ₄ between the _two is shorter than the distance L ₂ between the tip of the first protrusion 11 and the liquid permeable sheet 2 side of the absorber, and the density is high.
As described in detail in the first embodiment, the portion having a high density in the absorbent body is improved in the movement speed of the excretion liquid by capillary action, and can move the excretion liquid regardless of gravity. Become.
Therefore, also on the bottom 20a side of the second recess 20 in the absorbent body 4, the excretory fluid can be quickly moved and diffused along with the capillary phenomenon.

However, the distance L ₄ between the bottom 20 a side of the second recess 20 and the liquid permeable sheet 2 side in the absorbent body 4 is equal to the bottom 10 a of the first recess 10 because the liquid diffusion sheet 5 does not exist. Since the distance is longer than the distance L ₁ between the liquid permeable sheet 2 and the liquid permeable sheet 2, the density is also slightly reduced.
That is, the bottom 10a of the first recess 10 and the depth of the bottom 20a of the second recess 20 are basically the same, but the first recess 10 is liquid in addition to the absorber 4. Since the diffusion sheet 5 is also embossed, the absorber 4 is substantially compressed by the thickness of the liquid diffusion sheet 5 when the first recess 10 is formed. . Therefore, the density of the region between the bottom 10a side of the first recess 10 and the liquid permeable sheet 2 side in the absorber 4 is such that the density of the bottom 20a side and the liquid permeable sheet 2 side of the second recess 20 is the same. It is set higher than the density of the area in between.
Further, the distance L ₃ between the tip of the second convex portion 21 and the liquid permeable sheet 2 side in the absorbent body 4 is substantially the same as L _{3 in} the first embodiment, This region has the lowest density.
As a result, the movement speed of the excretory fluid in the absorbent body 4 is the fastest on the bottom 10a side of the first recess 10, and then on the bottom side of the second recess 20, the first projection 11 and the second projection 21. In order.

When forming the second concave portion 20 and the second convex portion 21, when embossing is performed, it is performed simultaneously with the formation of the first concave portion 10 and the first convex portion 11.
That is, an embossing roll in which an embossing pattern having a width equal to or larger than the width of the absorbent body 4 is formed on the peripheral surface, and the peripheral surface is formed by coating both the absorbent body 4 and the liquid diffusion sheet 5 with the covering sheet 7. Emboss between flat flat rolls. Thereby, the embossing along the embossing pattern is simultaneously performed on the contact portion of the liquid diffusion sheet 5 and the absorber 4 with the liquid diffusion sheet 5 and the portion of the absorber 4 where the diffusion sheet 5 is not in contact. It is formed.
In the case of the one shown in FIG. 6, the embossing pattern has a substantially rectangular lattice shape in plan view similar to FIG. 4 (when embossing, a substantially rectangular frame-shaped part is a concave part, and a part surrounded by the concave part. Is an embossed pattern), but the embossed pattern is not particularly limited, and a pattern in which a plurality of broken lines extending in the lengthwise direction of the absorber are arranged in the lengthwise direction of the absorber. It is the same as in the first embodiment that the pattern is preferably extended.

  In the second embodiment, the second concave portion 20 and the second convex portion 21 are provided at a position where the liquid diffusion sheet 5 is not disposed on the liquid-impermeable sheet side of the absorber 4. Other configurations are basically the same as those of the first embodiment, and the same reference numerals are given to omit the detailed description in order to achieve the same operational effects.

  The absorbent article 1B according to the second embodiment having the above configuration can basically obtain the same effects as those of the first embodiment. In addition to this, at the position where the liquid diffusion sheet 5 on the liquid-impermeable sheet side of the absorber 4 is not disposed, a plurality of second portions formed by compressing in the thickness direction by embossing. Since the concave portion 20 is provided, the excretory liquid can be moved and diffused as quickly as possible in the length direction and the width direction of the absorber also in the portion other than the range of the liquid diffusion sheet 5 in the absorber 4. Thereby, the absorption capability as the whole absorbent article can be improved further, and liquid leakage can also be suppressed by making it easy to diffuse.

  FIG. 8 shows a third embodiment of an absorbent article according to the present invention. The absorbent article according to the third embodiment has a liquid-impermeable sheet side with respect to the liquid-absorbing ability of the absorbent body. And the liquid permeable sheet side.

  That is, in the absorbent article 1C of the third embodiment, the absorbent body 30 includes pulp and a water-absorbing polymer, and a liquid-impermeable sheet for a water-absorbing polymer having a higher absorption capacity than pulp. The content ratio on the side is set higher than that on the liquid-permeable sheet side.

As described above, in the absorbent body 30, the content of the water-absorbing polymer on the liquid-impermeable sheet side is higher than that on the liquid-permeable sheet side. By increasing the liquid absorption amount on the impermeable sheet side, the excretion liquid can be transferred from the liquid diffusion sheet 5 to the absorber 30 more efficiently and quickly, and the liquid diffusion function of the liquid diffusion sheet 5 can be made as much as possible. This is to recover early.
That is, the excretion liquid retained by the liquid diffusion sheet is moved and absorbed by the absorber as soon as possible, so that the liquid diffusion sheet recovers the ability to absorb, retain and diffuse the excretion liquid again. The liquid can be continuously and repeatedly diffused.
As a result, even if the wearer discharges the excretion liquid a plurality of times, the liquid diffusion sheet whose liquid diffusion capacity has been recovered can stably diffuse the excretion liquid each time and be absorbed by the absorber. In addition, the absorption capacity of excretory fluid as the entire absorbent article is improved.

Regarding the content ratio of the water-absorbing polymer, in the case shown in FIG. 8, a region 30 a in which the water-absorbing polymer is concentrated is provided in a certain range on the liquid-impermeable sheet side of the absorber 30.
However, as long as the content ratio on the liquid-impermeable sheet side is higher than that on the liquid-permeable sheet side, the content ratio and the range of the water-absorbing polymer are not particularly limited. For example, like the absorber 30 shown in FIG. 9A, the cross section in the thickness direction of the absorber is equally divided into five in the thickness direction, and divided into first to fifth layers 31 to 35. When considered, the volume ratio (volume ratio) of the water-absorbing polymer contained in the first layer 31 located closest to the liquid-impermeable sheet with respect to the volume of the water-absorbing polymer contained in the entire absorber. Can be made higher than the other layers 32 to 35 (for example, 25 to 50%) to increase the content of the water-absorbing polymer on the liquid-impermeable sheet side than on the liquid-permeable sheet side.
Further, like the absorbent body 30 shown in FIG. 9B, the volume ratio (volume ratio) of the water-absorbing polymer of the first layer 31 is maximized, and the second layer adjacent to the first layer 31 is used. Also for the layer 32, the volume ratio of the water-absorbing polymer may be higher than those of the other layers 33 to 35. Furthermore, at this time, the sum of the volume of the water-absorbing polymer contained in the first layer 31 and the second layer 32 is 50 to 80% of the volume of the water-absorbing polymer contained in the entire absorbent body, and the liquid impermeability is not increased. It is good also as a structure which an absorption capability becomes high gradually as it goes to the property sheet side.

In this case, when the cross section in the thickness direction of the absorbent body 30 is divided into five equal parts in the thickness direction, the volume ratio of the water-absorbing polymer of each layer divided into five parts is, for example, as follows: Measured by various methods.
(1) X-ray CT observation and image analysis of the cross section of the absorber Non-destructive observation of the internal structure of the sample is performed using X-ray CT. Then, a three-dimensional image is obtained by analyzing the obtained data.
* When acquiring data, the sample is rotated 360 degrees, the X-ray absorption status data when the sample is rotated once, the same data when the sample is rotated twice, and so on. Get the data.
(2) Stereoscopic observation using analysis software (acquisition of stereoscopic and tomographic images)
A stereoscopic image is created by analysis software from a tomographic image obtained by X-ray CT.
The tomographic image is a two-dimensional image. The stereoscopic image is created by stacking the tomographic images.
(3) Volume measurement occupied by water-absorbing polymer by analysis software From the XY three-dimensional image obtained by X-ray CT, a measurement region is extracted and the volume of the water-absorbing polymer is measured.
From the three-dimensional image, the outermost fibers forming the absorber were tied together to form the absorber formation range.
Draw a rectangle in contact with the outermost part of the absorber, divide the longitudinal direction of the absorber into two and divide the cutting direction of the absorber into five, and measure the volume of the region and the volume of the water-absorbing polymer present in the rectangle. .
The average of a total of 10 points is obtained after X-ray CT observation and image analysis for each layer (in this case, 5 layers) of the sample by the above procedure.
(4) Details of how to determine the water-absorbing polymer volume In order to evaluate in three dimensions, a three-dimensional image is extracted and the volume is calculated.
[Boundary determination]
Specify the target area. (1 section of 5 divisions)
Extract the contrast of the water-absorbing polymer part.
The contrast other than the water-absorbing polymer portion is extracted.
The white part of the water-absorbing polymer part, and the other black and gray parts are binarized (white and black) to leave only the water-absorbing polymer part.
[Volume calculation]
After the software analyzes the pixels (pixels) of the water-absorbing polymer portion, it is converted into a voxel and three-dimensionalized, and converted to mm ³ as a unit, thereby calculating the volume from each pixel and voxel.
[Volume ratio calculation]
The volume ratio is calculated from the volume of the target region calculated by software and the total volume of the five cross sections using the following calculation formula (1).
(Volume ratio r) (%) = (volume of the target area) / (total volume of five cross sections existing in the rectangle of the target area) × 100 (1)
(5) Measurement conditions In addition, as a measurement condition in X-ray CT, the following can be used, for example.
Tube voltage: 40 kV
Tube current: 20 μA
Number of pixels: 1024 x 1024 pixels
Field size: 10.1mmφ × 10.1mmh
(6) Device Used As a device used for measuring the volume ratio of the water-absorbing polymer of the absorber, for example, the following can be used.
Three-dimensional measurement X-ray CT system: TDM1000-IS / SP (manufactured by Yamato Kagaku)
Three-dimensional volume rendering software: VG-Studio MAX (NVS).

In the case shown in FIG. 10, the volume of the water-absorbing polymer contained in the first layer 31 is 35% with respect to the volume of the water-absorbing polymer in the entire absorber, and 34% for the second layer 32. . The third layer 33 located in the central portion of the absorber 30 is 18%, the fourth layer 34 adjacent to the third layer 33 is 6%, and the third layer 33 located closest to the liquid permeable sheet. For layer 5 of 5 it was 7%.
From FIG. 10, it can be seen that the volume ratio of the water-absorbing polymer increases toward the liquid-impermeable sheet side, that is, the first layer side. Moreover, the sum of the volume of the water-absorbing polymer contained in the first layer 31 and the second layer 32 also reaches 69%, and the absorption capability of the absorbent 30 on the liquid-impermeable sheet side is liquid permeable. It can be seen that it is much higher than the seat side.

In addition, about formation of the absorber in which the volume of the water-absorbing polymer to contain is changing about the thickness direction of an absorber as mentioned above, it is possible to form by arbitrary methods.
For example, a general absorber manufacturing apparatus having a function of mixing a water-absorbing polymer when an absorber material such as pulp is laminated in a predetermined shape (for example, an absorber described in JP 2010-119655 A) Can be formed using a manufacturing apparatus. And, by changing the supply position of the water-absorbing polymer by adjusting the supply time of the water-absorbing polymer, or by changing the supply amount of the water-absorbing polymer, the timing of supply, etc., about the thickness direction of the absorber, Absorbers in which the volume of the water-absorbing polymer is changing can be formed.

  In the third embodiment, the content ratio of the water-absorbing polymer on the liquid-impermeable sheet side in the absorbent body 30 is made higher than that on the liquid-permeable sheet side, compared with the liquid absorption amount on the liquid-impermeable sheet side. The configuration other than the point of increasing the liquid absorption amount on the liquid-impervious sheet side is basically the same as the configuration of the first embodiment, and the same reference numerals are given to achieve the same operational effects. Detailed description is omitted.

  The absorbent article 1 </ b> C of the third embodiment having the above configuration can basically obtain the same effects as those of the first embodiment. In addition, since the liquid absorption amount on the liquid-impermeable sheet side in the absorbent body 30 is larger than the liquid absorption amount on the liquid-permeable sheet side, the excretory liquid from the liquid diffusion sheet 5 can be moved more efficiently. Therefore, there is an advantage that the liquid diffusion function of the liquid diffusion sheet 5 can be restored as early as possible. As a result, it is possible to continuously and repeatedly diffuse the excretory liquid to improve the absorption capacity as a whole.

FIGS. 11-15 shows 4th Embodiment of the absorbent article which concerns on this invention, The absorbent article of this 4th Embodiment is the said 1st-3rd embodiment. The configuration of the liquid diffusion sheet is greatly different.
That is, the liquid diffusion sheet 40 in the absorbent article 1D according to the fourth embodiment includes, as shown in FIGS. 11 to 13, a base 41 disposed on the liquid-impermeable sheet side, and the base 41. A plurality of flange portions 42 provided in the absorbent body side at regular intervals and extending in the length direction of the absorber 4 and projecting toward the absorber side, and a groove portion 43 formed between the adjacent flange portions 42, 42. Have.
Further, the base portion 41 has a higher fiber occupation cross-sectional area ratio than the flange portion 42, and the surface side region 42a of the flange portion 42 has a fiber occupation cross-sectional area larger than the inner region 42b located inside the surface side region 42a. The ratio is set high.
In the fourth embodiment, the configuration other than the liquid diffusion sheet 40 is basically the same as that of the first embodiment described above, and has the same effect. Detailed description will be omitted.

Here, in the present invention, the fiber occupying cross-sectional area ratio in the liquid diffusion sheet is a tomographic image obtained by X-ray CT of the liquid diffusion sheet, determines a measurement region, and is occupied by fibers in the measurement region. The ratio of the current area to the area of the measurement region.
In the liquid diffusion sheet, the portion having a high fiber-occupied cross-section ratio is basically high in density, and therefore the excretion fluid easily moves due to capillary action in the portion having the high fiber-occupied cross-section ratio. It is thought that the excretory fluid can be moved regardless of whether or not. On the other hand, it is considered that the portion where the fiber occupation cross-sectional ratio is low is basically low in density and hardly causes capillary action, but has a high ability to retain excretory fluid and functions as a conduit.

Therefore, in the case of the liquid diffusion sheet 40 of this embodiment, in the base 41 having the highest fiber-occupied cross-sectional area ratio, the excretory liquid is diffused particularly quickly against the gravity, and the surface area 42a of the buttocks However, since the fiber-occupied cross-sectional area ratio is relatively high, the diffusion of excretory fluid is also performed to some extent. Furthermore, in this liquid diffusion sheet 40, since it has the interface which generate | occur | produced by the difference in density, ie, the area | region where two density differences continue, it is thought that a capillary phenomenon is accelerated | stimulated in the interface.
Therefore, in this liquid diffusion sheet 40, from the inner region 42b (sparse) of the flange portion 42 having a low fiber occupation cross-sectional area ratio, the base portion 41 (dense) or the flange portion 42 having a fiber occupation cross-sectional area ratio higher than that of the inner region 42b. It is considered that the excretory fluid is transferred more efficiently to the surface side region 42a (dense), and that the excretory fluid can be diffused more effectively and quickly against gravity.

  In the case where the liquid diffusion sheet 40 is used, the liquid diffusion sheet 40 and the abutting portion of the absorber 4 with the liquid diffusion sheet 40 are embossed from the liquid-impermeable sheet side in the thickness direction. In the case of being compressed, the collar portion 42 may be compressed by embossing. However, even if the collar portion 42 is compressed, the density of the portion increases as a result, so that the excretory fluid can be quickly moved by capillary action, and the liquid diffusing ability is considered to be enhanced.

About the fiber occupation cross-sectional area ratio of each part of the base 41 of the said liquid-permeable sheet 40, the surface side area | region 42a of the collar part 42, and the inner side area | region 42b, what is necessary is just to satisfy the height relationship mentioned above, and a fiber occupation cross-section ratio The absolute value of is not particularly limited.
However, if the average fiber occupation cross-sectional ratio of the entire cross section in the width direction (short direction) of the liquid permeable sheet 40 is r _O , the fiber occupation cross-sectional area ratio r ₁ of the base 41 is preferably 1.2 r _O or more. There, the fibers occupied cross-sectional area ratio r ₂ of the surface area 42a of the ridge portion 42 is 0.8 r _O or more and less than 1.2R _O, fibers occupied cross-sectional area ratio r ₃ of the inner area 42b of the ridges 42 0 it is less than .8r _O. More preferably, the fibers occupied cross-sectional area ratio r ₁ of the base portion 41 is 1.2R _O or more and less than 2.0R _O, fibers occupied cross-sectional area ratio r ₂ of the surface area 42a of the ridge portion 42 is 0.8 R _O or more and less than 1.2R _O, fibers occupied cross-sectional area ratio r ₃ of the inner area 42b of the ridge portion 42 is 0.1 r _O or more and less than 0.8 r _O.

The fiber occupation cross-sectional area ratio is measured, for example, as follows.
(1) X-ray CT observation and image analysis of non-woven fabric cross section Non-destructive observation of the internal structure of the sample is performed using X-ray CT. Then, a tomographic image is obtained by analyzing the obtained data.
* Rotate the sample 360 degrees. At that time, the X-ray absorption status data when rotated once, the same data when the sample is rotated twice, and so on are acquired.
(2) Stereoscopic observation using analysis software (acquisition of stereoscopic and tomographic images)
A three-dimensional image is created from the tomogram obtained by X-ray CT using analysis software, and the internal situation (XY tomogram) is confirmed on an arbitrary XY section.
* A tomogram is a two-dimensional image, and a three-dimensional image is created by stacking tomograms.
(3) Fiber area measurement by analysis software A measurement area is extracted from an XY tomogram obtained by X-ray CT, and the fiber area is measured.
From the three-dimensional image and the XY tomographic image, the fibers constituting the XY tomographic image to be measured are connected to the outermost fibers present mainly in the part forming the buttock, thereby forming the ridge forming range.
Draw a rectangle that touches the outermost part of the buttock, divide into 3 parts in length, 5 parts in width, measure the cross-sectional area of the region, the cross-sectional area of the heel part in the rectangle, and the cross-sectional area of the fiber, The fiber occupation cross-sectional area ratio for each part is calculated.
The cross section is extracted as much as possible where there are no irregular parts, and the average is obtained after 10 points are measured.
(4) Details of how to obtain fiber cross-sectional area To perform two-dimensional evaluation, a tomographic image is extracted and the area is calculated. At this time, since the three-dimensional volume rendering software can be evaluated in two dimensions, it is used.
[Boundary determination]
Specify the target area. (1 section of 15 divisions, etc.)
Extract the contrast of the fiber part.
Extract contrast other than fiber.
The white, black, and gray parts are binarized (white and black) to create an interface.
[Area calculation]
After software analyzes the pixel of the heel part (pixel) and the pixel of the fiber part inside the rectangle that touches the buttock, the pixel is converted to μm ² as a unit, and the area is calculated from each pixel. .
[Area ratio calculation]
The cross-sectional area ratio is calculated from the area of the region calculated by the software and the fiber cross-sectional area using the following calculation formula (1).
(Fiber occupation cross-sectional area ratio r) (%) = (Fiber cross-sectional area of the target region) / (Cross-sectional area of the buttocks existing in the rectangle of the target region) × 100 (1)
(5) Measurement conditions In addition, as a measurement condition in X-ray CT, the following can be used, for example.
Tube voltage: 40 kV
Tube current: 15 μA
Number of pixels: 512 x 512 pixels
Field size: 2.5mmφ × 2.5mmh
(6) Used device As a used device for measuring the fiber occupation cross-sectional area ratio, for example, the following device can be used.
Three-dimensional measurement X-ray CT system: TDM1000-IS / SP (manufactured by Yamato Kagaku)
Three-dimensional volume rendering software: VG-Studio MAX (NVS).

An example of a method for producing the liquid diffusion sheet 40 will be briefly described. First, a fiber web is formed on a conveyor surface by a wet method using cellulose fibers as a main raw material, and then subjected to a water jet treatment to obtain a wet span. Make a lace nonwoven fabric.
Next, a steam jet process is performed from the conveyor surface side during the water jet process of the wet spunlace nonwoven fabric.

  At this time, as shown in FIG. 14 and FIG. 15, the fibers of the wet spunlace nonwoven fabric 52 on the suction drum 53 are scraped at regular intervals by the fluid jet from the steam jet nozzle 50 to the original wet span. Protrusions having a density lower than that of the lace nonwoven fabric 52 are formed. When the steam jet 51 strongly hits, the fiber push-up amount increases, and the protrusion 52a formed by the fiber push-up is warped, so that the tip of the protrusion 52 is more than the original position on the original wet spunlace nonwoven fabric 52. Land farther away. Thereby, the low density surrounded by the high density part A which is the original wet spunlace nonwoven fabric 52, the medium density part B composed of the fibers of the raised protrusions, and the high density part A and the medium density part B A density portion C is formed.

As a result, on the high density portion A that is the original wet spunlace nonwoven fabric, that is, the base portion 41, the groove portion 43 having the bottom portion 43a as the high density portion (that is, the base portion 41) remaining after the fibers are pushed up by the steam jet is adjacent to the groove portion 43. Between the matching groove portions 43, one or two flange portions 42 are formed in which the tips of the warped protrusions 52a and 52a are brought to face each other. At this time, in the collar portion 42, the medium density portion B becomes the surface side region 42a, and the low density portion C becomes the inner region 42b.
Moreover, the pattern of the collar part 43 can be changed with the pressure of a nozzle pattern, a conveyor mesh pattern, or a steam jet.

  When the absorbent article 1D having the above-described configuration is used, when the excretory liquid discharged from the wearer reaches the liquid diffusion sheet 40, the excretion liquid is absorbed by the absorbent body 4 and the liquid diffusion sheet 40, particularly the surface of the collar part 42. While moving on the interface with the side region 42a, it is absorbed by the inner region 42b through the surface side region 42a of the flange 42. Further, the excretory fluid absorbed by the inner region 42b is further moved and absorbed by the base 41. The excretion fluid absorbed by the base 41 and the excretion fluid remaining in the surface-side region 42a of the collar 42 begin to move through the base 42 and the surface-side region 42a due to capillary action, and are not affected by gravity. It moves and diffuses in the length direction of the diffusion sheet 40 and is absorbed by the buttocks side and the abdomen side of the absorber 4.

  According to the absorbent article 1D of the fourth embodiment having the above-described configuration, basically the same effect as that of the first embodiment can be obtained. However, the liquid diffusion sheet 40 is not limited to the first embodiment. Compared to the flat shape as in the embodiment, it has better absorbability and liquid diffusibility, so it is possible to hold and diffuse excretory liquid more efficiently and stably, and to further improve the absorption capacity. There is an advantage that it can be improved.

  In the second and third embodiments, the liquid diffusion sheet 5 having a flat front and back surface is used. However, as this liquid diffusion sheet, the liquid diffusion sheet 40 used in the fourth embodiment, that is, a base portion disposed on the liquid impervious sheet side, and a constant interval on the absorber side of the base portion. Provided with a plurality of flanges extending in the length direction of the absorber and projecting toward the absorber, and a groove formed between adjacent flanges, and the base is the flange Alternatively, a fiber-occupied cross-sectional area ratio may be higher than that, and a surface-side region in the ridge may have a fiber-occupied cross-sectional area ratio higher than a region inside the surface-side region.

  Moreover, in the said 2nd and 4th embodiment, although the absorber 4 blended so that a pulp and a water absorbing polymer may become a substantially uniform structure over the whole absorber main body is used, this absorption is used. As the body, the content of the absorbent 30 used in the third embodiment, that is, the water-absorbing polymer on the liquid-impermeable sheet side is higher than that on the liquid-permeable sheet side, You may use the thing whose liquid absorption amount by the side of a liquid-impermeable sheet is large compared with liquid absorption amount.

  In the fourth embodiment, as the liquid diffusion sheet 40, as shown in FIG. 12 and FIG. 13, the ribs 42 having substantially the same width are used. As shown in FIG. 16, the widths of the flanges 42 and the widths of the grooves 43 are not constant, and those having different structures can be used.

Furthermore, in the present invention, as the liquid diffusion sheet 40, as shown in FIG. 17, it extends in the length direction of the liquid diffusion sheet 41 at the approximate center of the flange 43, and does not reach the base at the end face on the absorber side. What formed the center area | region 42c in which the hollow 44 was formed can be used.
This central region 43c is formed in the manufacturing process of the liquid diffusion sheet 40, and when forming the flange portion 42 by the steam jet, the pressure from the steam jet is higher than that at the time of forming the flange portion shown in FIG. Formed when large. That is, when the pressure of the steam jet increases, the separated fibers are blown farther, and the protrusion pushed up by the steam jet becomes longer. Then, at the position where the tips of the warped projections land, the tips of adjacent projections collide with each other, and the colliding portion becomes the central region 42c. The depression 44 in the central region 42c is formed because adjacent protrusions having a curved shape collide with each other.

As described above, in the liquid diffusion sheet 40, when the central region 42c exists in the flange portion 42, the fiber occupation cross-sectional ratio is lower than the surface-side region 42a of the flange portion 42, but more than the inner region 42b. high.
Specifically, the fibers occupied cross-sectional area ratio r ₁ of the base portion 41 at this time is 1.2R _O or more, the fiber occupied cross-sectional area ratio r ₂ of the surface area 42a of the ridge portion 42 is 0.8 R _O above, 1.2R less than _O, the central area 42c fibers occupied cross-sectional area ratio r ₄ of the ridges 42 is 0.5r _O or more and less than 0.8 r _O, the inner region 42b fiber occupied cross-sectional area ratio r ₃ of the ridge portion 42 Is preferably less than 0.5 r 2 _O. More preferably, the fibers occupied cross-sectional area ratio r ₁ of the base portion 41 is 1.2R _O to less than 2.0R _O, fibers occupied cross-sectional area ratio r ₂ of the surface area 43a of the ridge portion 42 is 0.8 R _O above, less than 1.2R _O, fibers occupied cross-sectional area ratio r ₄ of the central region 42c of the ridge portion 42 is 0.5r _O or more and less than 0.8 r _O, fibers occupied cross-sectional area ratio r ₃ of the inner area 42b of the ridge portion 42 0.1 r 2 _O or more and less than 0.5 r 2 _O.

  Furthermore, in the fourth embodiment, as shown in FIG. 11, the tip side of the flange portion 42 of the liquid diffusion sheet 41 is in contact with the absorber 4, but this flange portion bites into the absorber. As a result, the liquid diffusion sheet more effectively and stably follows the deformation of the absorbent body, and the excretory liquid is stably moved between the absorbent body and the liquid diffusion sheet. There is an advantage. In addition, the liquid diffusion sheet has an effect of reinforcing the absorber.

  Moreover, although the said 1st-4th embodiment demonstrated the case of the disposable paper diaper as an absorbent article, the absorbent article of this invention is a sanitary napkin, an incontinence pad, etc. besides this. There may be.

In order to confirm the effect of the absorbent article of the present invention, a comparative experiment for comparing the absorbency of the absorbent article according to the present invention and the absorbent article not dependent on the present invention was conducted.
The comparative experiment described an absorbent article according to the present invention (hereinafter referred to as “Example”) and an absorbent article that is not dependent on the present invention (hereinafter referred to as “Comparative Example”). Experiments were performed, and the data of each time was obtained and compared for the amount of liquid return (rewetting amount), diffusion length in the length direction and width direction, assuming that the excretion liquid was discharged four times. .

For the examples, the same configuration as that of the second embodiment shown in FIGS. 6 and 7 is used, and for the comparative example, the same shape as that of the second embodiment is embossed. The one that was not used was used.
The liquid permeable sheet, the liquid impermeable sheet, the absorber, the configuration of the liquid diffusion sheet, the material, and the like used in the examples and comparative examples were the same as each other.
The absorbent body contains 56% pulp and 44% water-absorbing polymer (SAP), and the liquid diffusion sheet contains 24% rayon fiber, 46% beaten pulp, 30% unbeaten pulp, and the basis weight is 55 g / m ² was used.
Further, in the examples, the liquid diffusion sheet has a width of 65 mm and is arranged at the center in the width direction of the absorber, and the emboss pattern has a substantially lattice shape in plan view described in the first embodiment. It was. About the said embossing, it processed so that the depth of a recessed part might be about 30% of the thickness of an absorber, ie, 1.2 mm. In addition, about the depth of this recessed part, it measured using the high precision two-dimensional laser displacement meter GLJ-G030 made from KEYENCE.

The absorbent test is the same for each absorbent article having a length of 340 mm, a width of 120 mm, and a thickness of 4 mm at a position of 30 mm from the center of the absorber in the forward direction (abdominal side). Each component and a certain amount of artificial urine were injected, and the diffusion length of the artificial urine and the liquid return amount were examined. Specifically, the test was performed according to the following procedure.
(1) An absorber is arrange | positioned at the U-shaped instrument which hold | maintains an absorbent article in the side view substantially U shape. At this time, the positions of the absorber center and the U-shaped instrument center (the lowest position) are aligned.
(2) 70 mL of artificial urine is injected into the center of the absorber at 80 mL / 10 seconds from a 100 mL burette.
(4) Three minutes after the step (2), the outline of the area where the artificial urine spreads on the front and back surfaces of the absorber is recorded.
(5) After 4 minutes from the step (2), the absorbent article is spread and allowed to stand on a flat plate having a larger plan view shape than the absorbent article. Then, both the front and back surfaces of the artificial urine are measured and recorded as the diffusion length.
(6) Five minutes after the step (2), 50 g of 100 mm × 100 mm filter paper is left on the absorbent body with the artificial urine injection point in the middle. Further, a weight of 3.5 kg, 100 mm × 100 mm × 50 mm (height) is placed on the plate. For filter paper, the weight before the test is measured in advance.
(7) Eight minutes after the step (2), the weight is removed, the weight of the filter paper is measured, the weight of the filter paper before the test is subtracted, and the difference is defined as the liquid return amount.
(8) Nine minutes after the step (2), the sample is again placed on the U-shaped instrument.
(9) After 10 minutes from the step (2), the same steps as the steps (2) to (8) are repeated again. Do this until the 4th round (thus, the total injection volume of artificial urine is 280 mL), and record each result.
The absorptivity test was performed three times for each of the examples and comparative examples, and the diffusion length of artificial urine on the front surface (liquid permeable sheet side) and back surface (liquid impermeable sheet side) of the absorber, and the liquid return For each amount, the average value of three test results was calculated, and the average value was compared and evaluated.
The results are shown in Table 1.

As shown in Table 1, regarding the liquid return amount (rewetting amount) of artificial urine, when the average values were compared, the liquid return amount in the example was much smaller than that in the comparative example. Furthermore, throughout the first to fourth rounds of the test, all of the examples had consistently lower liquid return amounts than the comparative examples.
As a result, it was found that the absorption capacity of the example was higher than that of the comparative example. However, in the case of the example, the artificial urine was efficiently used on the back side (liquid-impermeable sheet side) of the absorber. This is considered to be because the artificial urine was able to be absorbed by the entire absorber by being diffused into the absorbent body. Particularly in the second and subsequent rounds, the liquid return amount of the example is much lower than that of the comparative example, which indicates that the artificial urine is diffused and absorbed firmly throughout the absorber.

On the other hand, regarding the diffusion of artificial urine, first, regarding the surface side, the maximum length of the diffusion length in the length direction (the length of the most diffused portion) was longer as an average value than in the comparative example. .
As a result, it can be seen that artificial urine diffused throughout the absorber is also absorbed on the surface of the absorber, that is, on the liquid-permeable sheet side.
Further, in the case of the example, since a large amount of artificial urine is diffused in the length direction of the absorber, conversely, diffusion in the width direction is expected to be less than that in the length direction. Therefore, it is considered that the excretion fluid leaks out from the crotch area (underfoot) of the diaper's crotch (so-called side leakage).

  Next, regarding the diffusion of artificial urine on the back side, the maximum length of the diffusion length in the length direction was shorter in the examples than the comparative example as an average value. This is considered to be because the diffusion of the artificial urine by the liquid diffusion sheet and embossing and the movement of the diffused artificial urine from the liquid diffusion sheet to the absorber are efficiently performed on the back side of the absorber. It is done. That is, on the liquid-impermeable sheet side of the absorber, the artificial urine diffused by the liquid diffusion sheet is efficiently absorbed by the absorber, so that the ability to repeatedly diffuse the artificial urine is restored, resulting in measurement. In some cases, the diffusion length is expected to be shorter than the comparative example.

  Therefore, according to the absorbent article of the present invention, it is demonstrated that the absorption capacity of excretory fluid can be improved by effectively utilizing the entire absorbent body while ensuring the capability of repeatedly diffusing excretory fluid in the liquid diffusion sheet. It was done.

1A-1D Absorbent article 2 Liquid-permeable sheet 3 Liquid-impermeable sheet 4,30 Absorber 5,40 Liquid diffusion sheet 10 Recess (first recess)
10a Bottom part of a concave part (first concave part) 11 Convex part (first convex part)
20 2nd recessed part 20a Bottom part of 2nd recessed part 21 2nd convex part 31 1st layer 32 2nd layer 33 3rd layer 34 4th layer 35 5th layer 41 Base 42 Gutter 42a Surface Side area 42b Inner area 43 Groove 43a Bottom of groove

Claims (6)

A liquid-permeable sheet, a liquid-impermeable sheet disposed on one surface side of the liquid-permeable sheet, and an absorber disposed between the liquid-permeable sheet and the liquid-impermeable sheet. An absorbent article provided,
Between the absorber and the liquid-impermeable sheet, a liquid diffusion sheet formed of a nonwoven fabric containing cellulose fibers and extending in the length direction of the absorber is disposed,
Formed by embossing the liquid diffusion sheet and the abutting portion of the absorber with the liquid diffusion sheet from the liquid-impermeable sheet side and compressing in the thickness direction, a plurality of the bottom side bites into the absorber A recess is provided ,
It is formed by embossing only the absorber from the liquid-impermeable sheet side and compressing it in the thickness direction at a position where the liquid diffusion sheet is not disposed on the liquid-impermeable sheet side of the absorber. An absorbent article provided with a plurality of second recesses .   The absorbent article according to claim 1, wherein the liquid diffusion sheet has a length in the width direction smaller than a minimum width portion in the width direction of the absorber. The absorbent article according to claim 1 or 2, wherein the absorbent body includes pulp and a water-absorbing polymer, and a content ratio of the water-absorbing polymer on the liquid-impermeable sheet side is higher than that on the liquid-permeable sheet side. . The absorbent article according to any one of claims 1 to 3, wherein the liquid diffusion sheet is a wet spunlace nonwoven fabric. The liquid diffusion sheet includes a base portion disposed on the liquid-impermeable sheet side, and a plurality of protrusions provided in the length direction of the absorber provided on the absorber side of the base portion and projecting toward the absorber side. A flange portion and a groove portion formed between adjacent flange portions, and the base has a higher fiber occupation cross-sectional area ratio than the flange portion, and the surface side region in the flange portion is the surface side region. The absorbent article of any one of Claims 1-4 whose fiber occupation cross-sectional area ratio is higher than an inner area | region. The liquid diffusion sheet according to any one of claims 1 to 5, wherein a liquid absorption height after 5 minutes of artificial urine is 120 mm or more in a water absorption test by a Krem method according to JIS P 8141: 2004. Absorbent article.