JP2015066381A - Absorbent article - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an absorbent article with high absorption capacity of an excretion liquid, which can reliably and stably perform shape retention of an absorber by enabling constant reinforcement of the absorber when a wearer wears it.SOLUTION: A liquid diffusion sheet 13, which is formed of a nonwoven fabric including a cellulose fiber and extends to a longer direction of an absorber 12, is disposed between the absorber 12 and a liquid impermeable sheet 11. The liquid diffusion sheet 13 comprises: a base part 20 disposed on the liquid impermeable sheet side; a plurality of ridge parts 21 which are provided on the absorber side of the base part 20 at regular intervals, protrude to the absorber side, and extend to the longer direction of the absorber 12; and groove parts 22 formed between the adjacent ridge parts 21 and 21, with which a bottom 22a is formed by the base part 20. The liquid diffusion sheet is attached to the absorber 12 in a state that the ridge parts 21 bite into the absorber 12.

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.

  As a disposable paper diaper that absorbs excretion fluid such as urine as an absorbent article, for example, a liquid permeable sheet (so-called top sheet) located on the wearer's skin side and a liquid permeable sheet ( In general, a so-called back sheet) and an absorber provided between the liquid-permeable sheet and the liquid-impermeable sheet are provided.

In recent years, due to the increase in CO ₂ gas and global warming, the interest in environmental protection and resource saving has increased, and in order to reduce the amount of materials used for absorbent articles, the weight and thickness have been reduced. Has been done. In addition, weight reduction and thickness reduction are extremely important themes for the wearer because they contribute to an improved feeling of use.
When weight reduction etc. are aimed at in an absorptive article, it is most effective to reduce the amount of use of an absorber, and especially the amount of pulp fiber among pulp fiber and water-absorbing polymer generally contained in an absorber is reduced. It can be reduced. If the amount of pulp is reduced, the ability to temporarily hold the waste fluid before it is absorbed by the water-absorbing polymer is reduced, and the absorber is likely to lose its shape. Or embossing.

However, when the absorbent body is wetted by excreted liquid, disappearance of hydrogen bonds between pulp fibers and collapse of the high-density part due to embossing, and furthermore, the absorbent body and the nonwoven fabric (covering sheet) that wraps the absorbent body In some cases, it may be difficult to maintain the shape of the absorbent body.
In addition, when the wearer who wears the absorbent article walks, stands or sits, the absorbent body is moved, making it more difficult to maintain the form of the absorbent body.

By the way, as described in Patent Document 1, for example, a liquid diffusion sheet disposed on the liquid-impermeable sheet side of the absorber is known.
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. Moreover, since a liquid diffusion sheet reinforces an absorber, it contributes also to the form maintenance of this absorber.

However, the thing of the said patent document 1 WHEREIN: An absorber may leave | separate from a diffusion sheet, and especially when a wearer walks, stands, or sits down, an absorber and a diffusion sheet are called. , There was a drawback of separating from each other.
If the liquid diffusion sheet is separated from the absorber in this manner, the reinforcing effect of the absorber by the liquid diffusion sheet is lost, so that the shape of the absorber cannot be maintained, and the absorber collapses. There was a possibility. In particular, the absorbent body tends to collapse in a state where the excretory fluid is absorbed, and therefore, it is necessary to always reinforce the absorbent body to suppress the collapse of the absorbent body.

JP 2008-284167 A

  The technical problem of the present invention is that the absorbent body can be reinforced at all times, so that the shape of the absorbent body can be reliably and stably maintained during wearing, and the absorbability of the excretory fluid is high. To provide an article.

  In order to solve the above problems, an absorbent article according to the present invention includes a liquid-permeable sheet, a liquid-impermeable sheet, and a liquid-permeable sheet and a liquid-impermeable sheet disposed between the liquid-permeable sheet and the liquid-impermeable sheet. An absorbent article having a long absorbent body in the direction, which is formed by a nonwoven fabric containing cellulose fibers between the absorbent body and the liquid-impermeable sheet, and extends in the longitudinal direction of the absorbent body The liquid diffusion sheet is provided at a fixed interval on a base portion disposed on the liquid-impermeable sheet side and on the absorber side of the base portion, protrudes toward the absorber side, and extends in the longitudinal direction of the absorber. A plurality of flanges and a groove formed between the adjacent flanges, the bottom of which is formed by the base, are attached to the absorber in a state where the flanges are bitten into the absorber. It is what has been.

In the present invention, in the liquid diffusion sheet, the base portion has a higher fiber occupation cross-sectional area ratio than the heel portion, and the surface side region in the heel portion has a fiber occupancy cross-sectional area ratio than a region inside the surface side region. It can be formed high.
Moreover, in this invention, the said liquid diffusion sheet shall have the said collar part and a groove part formed continuously over the full length of the longitudinal direction of this liquid diffusion sheet, respectively.
Furthermore, in the present invention, the liquid diffusion sheet can be raised at least at a portion in contact with the absorber.

In the present invention, the liquid diffusion sheet is covered with a covering sheet together with the absorber, and the bending rigidity in the longitudinal direction and the width direction of the liquid diffusion sheet is set higher than that of the covering sheet. It is preferable.
Furthermore, in the present invention, the liquid diffusion sheet may have a length in the width direction that is smaller than a maximum width portion in the width direction of the absorber and larger than a minimum width portion in the width direction of the absorber. Good.

In the present invention, the absorber includes pulp and a water-absorbing polymer, and the liquid-absorbent sheet has a higher content of water-absorbing polymer than the liquid-permeable sheet, and the liquid-permeable sheet. It is preferable that the liquid absorption amount on the liquid impermeable sheet side is larger than the liquid absorption amount on the side.
In this case, the absorbent body has a water-absorbing polymer with respect to the volume of the water-absorbing polymer contained in the entire absorbent body when the cross section in the thickness direction of the absorbent body is equally divided into 5 parts in the thickness direction. It has a water-absorbing polymer high-body laminate formed with the highest volume fraction and a water-absorbing polymer low-body laminate with a lower volume fraction than the water-absorbing polymer super-layer laminate, and at least the most liquid-impermeable The 1st layer located in the sheet | seat side shall be a water absorptive polymer high body lamination | stacking.

Furthermore, at this time, only the first layer is configured as a water-absorbing polymer high-body laminate, and the volume of the water-absorbing polymer contained in the first layer is the volume of the water-absorbing polymer contained in the entire absorber. Of 25 to 50%. Furthermore, in this case, the absorbent article according to claim 8. The sum of the volume of the water-absorbing polymer contained in the first layer and the second layer adjacent to the first layer is 50 to 80% of the volume of the water-absorbing polymer contained in the entire absorbent body. can do.
Alternatively, only the first layer is configured as a water-absorbing polymer high-body laminate, and the volume of the water-absorbing polymer contained in the first layer is 33 to 33% of the volume of the water-absorbing polymer contained in the entire absorber. 50% of the water-absorbing polymer low-layer laminate, and the water-absorbing property contained in each of the third layer that is the center layer of the absorber and the fifth layer that is located closest to the liquid-permeable sheet. The volume of the polymer may be 25 to 33% of the volume of the water-absorbing polymer contained in the entire absorbent body.

Furthermore, the absorbent body includes the first layer, the third layer that is the central layer of the absorbent body, and the fifth layer that is located closest to the liquid-permeable sheet, each having a high water-absorbing polymer height. It can be a body laminate.
In this case, the volume of the water-absorbing polymer contained in each of the water-absorbing polymer high-body laminates is 25% or more of the volume of the water-absorbing polymer contained in the entire absorbent body, and The total volume of the water-absorbing polymer contained in the body laminate may be 75% to 100% of the volume of the water-absorbing polymer contained in the entire absorbent body.

  In the present invention, the absorber may have a weight ratio of the water-absorbing polymer contained in the absorber of 0.5 or more.

According to the present invention, since the liquid diffusion sheet is attached to the absorbent body in a state where the collar portion protruding from the absorbent body side of the base is bitten into the absorbent body, the wearer of the absorbent article can walk. Even if the absorbent body is moved due to standing or sitting, the liquid diffusion sheet always reinforces the absorbent body following the movement of the absorbent body. Therefore, the shape of the absorber can be reliably and stably maintained when worn.
In addition, since the liquid diffusion sheet and the absorber are always in close contact with each other, the excretory liquid can be stably diffused by the liquid diffusion sheet, so that the excretory liquid can be efficiently absorbed in the absorber. Therefore, the absorption capacity as the whole absorbent article can be improved.

FIG. 1 is a partially broken plan 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. However, the chassis, the liquid-permeable permeable sheet, and the leak-proof wall are omitted. FIG. 4 is a perspective view of a main part schematically showing an example of the liquid diffusion sheet of the absorbent article according to the present invention. FIG. 5 is a B-B ′ end view of FIG. 4. FIG. 6 is an explanatory view schematically showing a state in which steam jet treatment is performed in the production of the liquid diffusion sheet of the absorbent article according to the present invention. FIG. 7 is a diagram for explaining the principle that the surface side region and the inner region of the heel portion are formed by the steam jet process. FIG. 8 is an enlarged end view of a main part schematically showing a second embodiment of the absorbent article according to the present invention. However, the chassis and leakage barrier are omitted. FIG. 9 is a photograph showing a cross-sectional tomogram in the thickness direction of the absorber shown in FIG. FIG. 10 is a partially broken plan view schematically showing a third embodiment of the absorbent article according to the present invention. FIG. 11 is an enlarged end view of a main part taken along line C-C ′ of FIG. 10. However, the chassis, the liquid-permeable permeable sheet, and the leak-proof wall are omitted. FIG. 12 is a cross-sectional view schematically showing a liquid diffusion sheet having a configuration different from that of FIGS. 4 and 5. FIG. 13 is a cross-sectional view schematically showing a liquid diffusion sheet having a configuration different from that shown in FIG. FIG. 14 is an enlarged end view of a main part schematically showing a state in which an absorber having a configuration different from that in FIG. 8 is used. FIG. 15 is an enlarged end view of a main part schematically showing a state in which an absorber having a configuration different from that of FIG. 14 is used.

1 to 4 show a first embodiment of an absorbent article according to the present invention. In the first embodiment, a case where the absorbent article is a disposable paper diaper will be described.
That is, the absorbent article 1 is positioned on the outermost side when a paper diaper is mounted, and covers the wearer's abdomen, crotch, and buttocks, and has a chassis 2 that is long in the front-rear direction (vertical direction in FIG. 1). And a flap portion 3 provided integrally on the left and right sides of the chassis 2.
In FIG. 1, the lower side in the figure is the abdomen side of the chassis 2 (ie, the front side of the paper diaper), and the upper side is the heel part side (ie, the rear side of the paper diaper).

In addition, a liquid-permeable sheet 10 and a liquid-impermeable sheet 11 extending in the longitudinal direction of the chassis 2 and a space between the liquid-permeable sheet 10 and the liquid-impermeable sheet 11 are disposed at the center of the chassis 2. A strip-shaped absorber 12 that extends in the longitudinal direction of the chassis 2 is provided.
Further, a liquid diffusion sheet 13 extending in the longitudinal direction of the absorbent body 12 formed of a nonwoven fabric containing cellulose fibers is disposed between the absorbent body 12 and the liquid-impermeable sheet 11.
Further, between the liquid impervious sheet 11 and the liquid diffusion sheet 13, it becomes obvious when the liquid is wet with excrement liquid, and the fact that the excretion liquid is discharged is passed through the impermeable sheet 11 to the outside of the chassis 2. An indicator 4 is provided for discriminating from the above.

  In FIG. 1 to FIG. 3, reference numeral 5 indicates an expansion member for a chassis such as rubber that expands and contracts the vicinity of the left and right end portions of the flap portion 3 that contact the crotch of the wearer, and reference numeral 6 indicates the chassis 2. It is a leak-proof wall that protrudes upward and prevents excretion fluid such as urine and loose stool from leaking from the left and right sides of the diaper 1 when worn. Moreover, the code | symbol 7 is the tape 7 for a connection used for the connection of the buttocks side and the abdomen side of the chassis 2 at the time of wear to the wearer of a paper diaper.

The liquid permeable sheet 10 is disposed on the surface of the absorbent body 12 facing the skin surface of the wearer, and abuts against the skin surface of the wearer to quickly absorb the wearer's urine, It is made to transfer to the absorber 12, and is formed by a nonwoven fabric, a woven fabric, a synthetic resin film in which liquid permeation holes are formed, a net-like sheet having a mesh, or the like.
Examples of the nonwoven fabric used for the liquid-permeable sheet 10 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 polyesters such as tarate and polylactic acid; polyamides 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 11 is provided on a surface of the absorber 12 opposite to the surface on which the liquid permeable sheet 10 is disposed. It is attached to the position stationary, and prevents the discharged excrement from permeating to prevent it from leaking out of the chassis 2.
Examples of the liquid-impermeable sheet 11 include a waterproof nonwoven fabric, a synthetic resin (eg, polyethylene, polypropylene, polyethylene terephthalate, etc.) film, and 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.

The absorbent body 12 absorbs and holds the wearer's urine, includes pulp fibers and a water-absorbing polymer, and has an outer peripheral surface covered with the liquid diffusion sheet 13 and a covering sheet 14.
The absorbent body 12 and the covering sheet 14 are bonded to each other by a hot melt adhesive 16 interposed between the absorbent body 12 and the covering sheet 14.
In the case of what is shown in FIG. 1, the absorbent body has a shape corresponding to the wearer's crotch portion in the longitudinal portion curved toward the inner side of the absorbent body in plan view. The portion located on the innermost side of the curved portion is the minimum width portion of the absorber.

Further, in the absorbent body 12, the ratio of the weight of the water-absorbing polymer to the total weight of the absorbent body (weight of the water-absorbing polymer contained / weight of the whole absorbent body) is 0.5 or more. It is configured.
Thus, the weight ratio of the water-absorbing polymer to the weight of the pulp fiber was set to 0.5 or more because the water-absorbing polymer superior in water absorption to the pulp was used within the range not affecting the absorption capacity of the absorber. This is to increase the rate of use as much as possible and suppress the amount of pulp fiber used. Thereby, while reducing the usage-amount of a pulp as much as possible and reducing the weight as the whole absorber, it is trying to maintain the absorbed amount of excretory fluid as much as possible.

  Here, as the pulp used for the absorber in the present invention, for example, wood pulp obtained from coniferous or hardwood as a raw material (for example, machined wood pulp, refiner ground pulp, thermomechanical pulp, chemithermomechanical pulp, etc.) Pulp; Chemical pulp such as kraft pulp, sulfide pulp and alkali pulp; Semi-chemical pulp etc.); Mercerized pulp or crosslinked pulp obtained by chemically treating wood pulp; Bagasse, kenaf, bamboo, hemp, cotton (eg cotton) Non-wood pulp such as linter); regenerated cellulose such as rayon and fibril rayon; semi-synthetic cellulose such as acetate and triacetate.

  In addition, examples of the water-absorbing polymer used in the absorbent body in the present invention 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.

  Further, the covering sheet 14 is not particularly limited as long as it has liquid permeability and absorber retention, but from the viewpoint of low cost and absorber retention, tissue formed by a wet method using pulverized pulp as a main material. Is preferred.

On the other hand, as shown in FIGS. 4 and 5, the liquid diffusion sheet 13 absorbs excretory fluid that has moved to the liquid-impermeable sheet side of the absorbent body 12 (the lower surface side of the absorbent body in FIGS. 2 and 3). Further, it is diffused in the longitudinal direction and the width direction, the length in the longitudinal direction is substantially the same as the length in the longitudinal direction of the absorbent body 12, and the length in the width direction is the minimum width (of the crotch portion). It is formed narrower than (width).
The liquid diffusion sheet 13 is provided at regular intervals on the base 20 disposed on the liquid-impermeable sheet side and on the absorber side (upper side in FIGS. 2 and 3) of the base 20, and on the absorber side. A plurality of flanges 21 projecting and continuously extending in the longitudinal direction of the absorber 12, and a groove 22 formed between the adjacent flanges 21 and having a bottom 22 a formed by the base 20 are provided.

And this liquid diffusion sheet 13 is attached to this absorber 12 in the state in which each said collar part 21 bites into the said absorber 12. FIG.
In the case of the one shown in FIG. 3, not all of the flange portion 21 of the liquid diffusion sheet 13 bites into the absorber 12, and a slight gap is formed between the bottom of the groove portion 22 and the absorber 12. Has been.

The degree of biting of the collar portion can be arbitrarily set as long as the liquid diffusion sheet can be securely and stably attached to the absorber. For example, the entire collar portion is bitten into the absorber. May be. At this time, the water-absorbing polymer present in the absorbent body may move to the bottom part of the groove part of the liquid diffusion sheet at the time of manufacturing or use of the absorbent article, but the gap between the bottom part of the groove part and the absorbent body Is held stably.
Further, in the case where the collar portion of the liquid diffusion sheet is caused to bite into the absorbent body, for example, a manufacturing apparatus for producing an absorbent body by laminating absorbent materials such as pulp fibers in a predetermined shape while mixing a water-absorbing polymer. (For example, the manufacturing apparatus of the absorber described in Unexamined-Japanese-Patent No. 2010-119655) can be performed. And when laminating | stacking the said absorber material in the type | mold formed in the outer peripheral surface of a suction drum, by previously arrange | positioning the said liquid diffusion sheet in this type | mold so that a collar part may face outward In addition, it is possible to form an absorber in a state in which the collar portion of the liquid diffusion sheet is bitten. Alternatively, any means can be used such as, after the absorber is manufactured, the liquid diffusion sheet is disposed and pressed in a state where the collar portion is in contact with the absorber.

  Further, the liquid diffusion sheet 13 has the flange portion 21 and the absorbent body 12 bonded to each other by the hot-melt adhesive 17, while the base 20 has a surface opposite to the arrangement side of the flange portion 21, That is, the surface on the liquid-impermeable sheet side (the lower surface of the base in FIGS. 2 and 3) is bonded to the covering sheet 14 by the hot-melt adhesive 18. As described above, the covering sheet 14 is integrally covered with the absorber 12.

Here, the liquid diffusion sheet 13 has a configuration in which a flange portion 21 and a groove portion 22 are formed on one surface side of the base portion 20, and the flange portion 21 is attached to the absorber 12 in a state of being bitten into the absorber 12. The reason is as follows.
That is, the liquid diffusion sheet 13 and the absorber 12 are prevented from being separated from each other, so that the integrity is always maintained, and the excretory fluid moving from the absorber 12 is stably absorbed by the liquid diffusion sheet 13. This is because the absorbent body 12 is reinforced by the liquid diffusion sheet 13 and the shape of the absorbent body 12 is maintained.

As already described, when the absorbent body becomes wet by the excretory fluid, the absorbent body loses hydrogen bonds between pulp fibers, collapses high-density portions, and absorbs the absorbent body and the covering sheet that wraps the absorbent body. Since the adhesive to be bonded may come off, it may be difficult to maintain the shape of the absorber. Moreover, when the wearer who wears the absorbent article walks, stands, or sits down, the absorbent body is swayed, making it more difficult to maintain the form of the absorbent body.
Therefore, it is conceivable to attach a liquid diffusion sheet to the absorber and reinforce the absorber with the liquid diffusion sheet. However, when the wearer walks, stands, or sits, even if the absorbent body and the liquid diffusion sheet are bonded with an adhesive, the absorbent body and the diffusion sheet are separated and separated from each other. there is a possibility. Thus, if the liquid diffusion sheet and the absorbent body are separated, the reinforcing effect of the absorbent body by the liquid diffusion sheet is lost, and the absorbent body is more collapsed when absorbing the excretory fluid. Therefore, the shape of the absorber cannot be maintained.

  Therefore, in the present invention, the liquid diffusion sheet and the absorber are integrated by attaching the liquid diffusion sheet to the absorber in a state where the collar formed on the liquid diffusion sheet is bitten into the absorber. The liquid diffusion sheet can always follow the movement of the absorber even if the absorber is moved. Thereby, it is possible to reliably and stably hold the shape of the absorber by the liquid diffusion sheet.

Further, the liquid diffusion sheet 13 is set so that the bending rigidity in the longitudinal direction and the width direction of the liquid diffusion sheet 13 is higher than that of the covering sheet.
As a result, the absorber 12 can be deformed and easily deformed between the portion where the liquid diffusion sheet 13 is in contact and the other portion, that is, the portion which is in contact only with the covering sheet 14. And so on. More specifically, in the vicinity of the end of the liquid diffusion sheet 13, the deformation of the absorber 12 is greatly different from the end of the liquid diffusion sheet 13. As a result, the end of the liquid diffusion sheet 13 is changed. Since it becomes easy to induce the deformation starting from the portion, it is possible to make it difficult for the absorber 12 to be irregularly deformed. Therefore, even if the absorber 12 receives an external force in accordance with the wearer's movement, etc., the deformation due to the external force can be induced to give the deformation a certain degree of regularity. The damage of the body 12 can be reduced, and the collapse of the absorber 12 can be suppressed as much as possible.

Further, the liquid diffusion sheet 13 is raised on the surface side of the flange portion 21 which is a portion in contact with the absorber 12.
Thus, by raising the part in contact with the absorbent body, the density on the absorbent body side of the liquid diffusion sheet is reduced, and the pulp fibers in the absorbent body 12 are easy to bite, and at the same time due to partial hydrogen bonding between the pulp fibers. The effect of stabilizing the structure and strength is obtained. Here, as a method for raising the liquid diffusion sheet, various means such as adding fibrillated beating pulp to the liquid diffusion sheet or performing a steam jet treatment can be used.

In addition, as the liquid diffusion sheet in the present invention, non-woven fabrics containing cellulose fibers which are hydrophilic fibers and other beating pulp are used, and wet spunlace nonwoven fabrics are 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 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.

  In addition, when using pulp as these natural celluloses and rayon as regenerated cellulose, the mixing ratio of these pulps and rayon is preferably 10 to 70 parts by mass, and further 15 to 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.).

In addition, the said liquid diffusion sheet 13 has a density of about 50-280 mg / cm < ³ >, Preferably it has a density of 60-200 mg / cm < ³ >.
By setting the density of the liquid diffusion sheet 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.
As the basis weight of the liquid diffusion sheet, preferably about 35~70g / m ^2, more preferably 40 to 60 g / m ^2, more preferably be 45~55g / m ^2.
If the basis weight of the liquid diffusive sheet is less than 35 g / m ² , the fiber amount as a whole will be insufficient, and the effect on capillary action and shape retention will be reduced. Moreover, when it exceeds 70 g / m <2>, the thickness as the whole absorbent article, especially the part which has arrange | positioned the liquid diffusion sheet may become excessively thick, and a problem may arise in a usability | use_condition.

Furthermore, the liquid diffusion sheet 13 preferably has a liquid absorption height after 5 minutes of artificial urine of 130 mm or more, more preferably 135 mm or more, and further preferably 140 mm or more in a water absorption test by the Krem method. is there. Furthermore, the water absorption ratio is preferably 2.4 times or more, more preferably 2.6 times or more, and further preferably 3.0 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. Is increased, the capillary diameter is increased, the suction height is decreased, and the suction amount is increased.
However, when the liquid diffusion sheet is made into a wet spunlace nonwoven fabric, the wet spunlace nonwoven fabric has already taken a sparse / dense structure through papermaking, water jet, and drying processes (the entangled part by hydroentanglement is dense). State). 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 using the wet spunlace nonwoven fabric, since the sparse / dense structure is already formed, when the density between the sparse entangled parts is reduced, the suction amount increases and the density is increased. It is considered that the entangled portion is supplied with liquid from between the entangled portions, and the suction height is further increased.

  In the first embodiment, the liquid diffusion sheet 13 is formed such that the fiber-occupied cross-sectional area ratio of the base portion 20 is higher than that of the flange portion 21. Furthermore, the surface side region 21a corresponding to the surface layer portion of the flange portion 21 is an inner layer region located inside the surface side region 21a, that is, the flange portion 21 surrounded by the surface side region 21a and the base portion 20. The fiber occupation cross-sectional area ratio is higher than that of the inner region 21b.

Here, in the present invention, the fiber-occupied cross-sectional area ratio is a measurement of the area occupied by the fiber in the measurement region in a tomographic image obtained by X-ray CT of the nonwoven fabric. The ratio to the area of the 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, the liquid diffusion sheet can surely perform the movement and diffusion of the excretory liquid in the longitudinal direction, so that an excellent liquid absorption height can be obtained, while the suction amount can be sufficiently secured. it can.

Further, in the base portion 20 having a high fiber occupation cross-sectional area ratio, the liquid diffusion sheet 13 diffuses excretory fluids against gravity in a particularly rapid manner. Furthermore, in this liquid diffusion sheet 13, 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 13, from the inner region 21 (sparse) of the flange portion 21 having a low fiber occupation sectional area ratio, the base portion 20 (dense) or the flange portion having a higher fiber occupation sectional area ratio than the inner region 21b. It is considered that the excretory fluid is transferred to the surface side region 21a (dense) 21 more efficiently, and that the excretory fluid can be diffused more effectively and quickly against gravity.

About the fiber occupation cross-sectional area ratio of each part of the base 20 of the said liquid diffusion sheet 13, the surface side area | region 21a of the collar part 21, and the inner side area | region 21b, what is necessary is just to satisfy the height relationship mentioned above, and the fiber occupation cross-section ratio of The absolute value is not particularly limited.
However, when the average fiber occupation cross-sectional ratio of the entire cross section in the width direction (short direction) of the liquid diffusion sheet 13 is r _O , the fiber occupation cross-sectional area ratio r ₁ of the base portion 20 is preferably 1.2 r _O or more. , fibers occupied cross-sectional area ratio r ₂ of the surface area 21a of the ridge portion 21 is 0.8 r _O or more and less than 1.2R _O, fibers occupied cross-sectional area ratio r ₃ of the inner region 21b of the ridges 21 is 0. it is less than 8r _O. More preferably, the fibers occupied cross-sectional area ratio r ₁ of the base 20 1.2R _O or more and less than 2.0R _O, fibers occupied cross-sectional area ratio r ₂ of the surface area 21a of the ridge portion 21 is 0.8 R _O or more and less than 1.2R _O, fibers occupied cross-sectional area ratio r ₃ of the ridges 421 inner region 21b 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 square, 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 square 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 13 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. 6 and FIG. 7, the fibers of the wet spunlace nonwoven fabric 32 on the suction drum 33 are scraped at regular intervals by the fluid jet from the steam jet nozzle 30 to the original wet span. Protrusions having a density lower than that of the lace nonwoven fabric 32 are formed. When the steam jet 31 strongly hits, the fiber push-up amount increases, and the protrusion 32a formed by the fiber push-up is warped, and the tip of the protrusion 32a lands farther from the original wet spunlace nonwoven fabric 32. . Thereby, it was 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 protrusion 32a, and the high density part A and the medium density part B. A low density portion C is formed.

As a result, the high-density portion that is the original wet spunlace nonwoven fabric, that is, the high-density portion remaining after the fibers are pushed up by the steam jet, that is, the groove portion 22 and the groove portion 22 having the base portion 20 as the bottom portion 22a. In the meantime, one or two flange portions 21 are formed in which the tips of the warped protrusions 32a and 32a are brought to face each other. At this time, as for the collar part 21, the said medium density part becomes the surface side area | region 21a, and the said low density part becomes the inner side area | region 21b.
In addition, the pattern of the collar part 21 can be changed with the pressure of a nozzle pattern, a conveyor mesh pattern, or a steam jet.

The movement of the excretory fluid when the absorbent article having the above configuration is worn will be described.
First, when excretion fluid is discharged from the wearer, the excretion fluid passes through the liquid-permeable sheet 10 and moves to the absorber 12.
The excretory fluid that has moved to the absorbent body 12 is diffused along the cover sheet 14, while moving to the absorbent body 12 through the cover sheet 14. The excretory fluid that has moved to the absorbent body 12 moves along the surface of the absorbent body 12, but also moves to the interfiber spaces of the pulp of the absorbent body 12, and absorption by the water-absorbing polymer is started. . At this time, most of the excretory fluid is absorbed in the crotch portion of the absorber 12 or in the vicinity thereof.
When the excretory fluid is absorbed by the water-absorbing polymer, the water-absorbing polymer swells and the density of the absorber 12 at that portion decreases, so that the excreted fluid is not absorbed and passes through the absorber 12. The excreted liquid that has not been absorbed reaches the liquid diffusion sheet 13.

The excretory fluid that has reached the liquid diffusion sheet 13 moves on the interface between the absorber 12 and the surface of the flange 21 that is in contact with the absorber 12, while the surface of the flange 21 enters the surface-side region 21a. Absorbed. Further, some of the excreted fluid absorbed in the surface side region 21a moves in the longitudinal direction of the liquid diffusion sheet 13 by moving through the surface side region 21a by capillary action, but most of the fluid moves to the inner region 21b. The excreted fluid absorbed and absorbed by the inner region 21b is further moved to the base 20 and absorbed.
The excretory fluid absorbed by the base 20 starts to move through the base 20 by capillary action, and moves and diffuses in the longitudinal direction of the liquid diffusion sheet 13, that is, the buttocks side and the abdomen side of the paper diaper 1 regardless of gravity. And it will be absorbed by the buttocks side and the abdomen side of the absorber 12.

At this time, since the excretion fluid from the wearer is not directly excreted on the abdomen side and the buttock side of the absorbent body 12, there is still room for the amount of excretion fluid absorbed. The impervious sheet side is hardly used to absorb excretory fluid at this point. Therefore, the excretory liquid diffused in the longitudinal direction of the liquid diffusion sheet 13 is efficiently absorbed by the absorbent body 12 on the abdomen side and the buttock side.
On the other hand, the liquid diffusion sheet 13 in which the excretory liquid is absorbed on the abdomen side or the buttock side of the absorbent body 12 is restored to the ability to absorb and retain and diffuse the excretion liquid again, as long as the excretion liquid retained is lost. Therefore, the excretory fluid retained by the crotch portion is continuously diffused and sequentially absorbed on the abdomen side and buttocks side of the absorbent body 12. Thereby, since the liquid diffusion sheet 13 continues to recover as long as the diffused excretion liquid is absorbed from the abdomen side or the buttocks side of the absorber 12, the liquid diffusion sheet 13 can repeatedly diffuse the excretion liquid. .
As a result, even if the wearer discharges the excretion liquid a plurality of times, the liquid diffusion sheet 13 whose liquid diffusion capacity has been restored stably diffuses the excretion liquid each time, so that the excretion liquid is reliably transferred to the absorber 12. It can be absorbed and retained.

And the absorbent article which has the said structure is attached to this absorber 12 in the state in which the said liquid diffusion sheet 13 bited into the absorber 12 the collar part 21 protrudingly provided by the absorber side of the said base 20. Therefore, even if the absorbent body 12 is moved due to the wearer of the absorbent article walking, standing or sitting, the liquid diffusion sheet 13 follows the movement of the absorbent body 12, At least the flange portion 21 is always kept in close contact with the absorber 12.
In addition, the liquid diffusion sheet 13 itself is prevented from being separated and separated from the absorber 12 due to the increased adhesion to the absorber 12, and the integrity with the absorber 12 is impaired. Is deterred.
Thereby, since the said absorber 12 is always reinforced by the said liquid diffusion sheet 13, it becomes possible to carry out the shape maintenance of this absorber 12 reliably and stably at the time of wear.

Further, since the liquid diffusion sheet 13 is bonded to the absorbent core 12 using the hot melt adhesive in a state in which the flange 21 is bitten into the absorbent body 12, Even if the absorbent body 12 is deformed, the ridge portion 21 that has been entrapped suppresses the movement of the pulp fibers and the water-absorbing polymer in the absorbent body 12 to some extent, the divergence between these pulp fibers and the water-absorbing polymer, and the absorbent body 12. And the liquid diffusion sheet 13 can be suppressed. This is because when the compressing or shearing action in the width direction of the absorber generated when the absorbent article is worn, the bite and the adhesion point by the hot melt adhesive exist not only in the plane direction of the absorber 12 but also in the cross-sectional direction. This is because the load during compression and shearing action is dispersed in the plane direction and the cross-sectional direction.
Therefore, the liquid diffusion sheet 13 can retain the shape of the absorber 12 more effectively because the bite 21 itself that has been bitten contributes to the shape maintenance of the absorber 12.

FIGS. 8-10 shows 2nd Embodiment of the absorbent article of this invention, The absorbent article of this 2nd Embodiment is an absorber of the said 1st Embodiment. The configuration is different.
That is, the absorber in the second embodiment has a higher content of the water-absorbing polymer on the liquid-impermeable sheet side than on the liquid-permeable sheet side, and the liquid absorption amount on the liquid-permeable sheet side is larger. The liquid absorption amount on the impermeable sheet side is increased.

  Specifically, the absorbent body 41 of the absorbent article according to the second embodiment has an absorbent body when the cross section in the thickness direction of the absorbent body 41 is equally divided into five layers in the thickness direction. The water-absorbing polymer high body laminate 42 formed with the highest volume ratio containing the water-absorbing polymer with respect to the volume of the water-absorbing polymer contained in the whole, and the water-absorbing polymer high-body laminate 42 is contained. A low-volume water-absorbing polymer low-body laminate 43. Of the first to fifth layers 44 to 48, at least the first layer 44 positioned closest to the liquid-impermeable sheet is the water-absorbing polymer high-body laminate 42.

Further, in the case shown in FIG. 8, only the first layer 44 is the water absorbent polymer high body laminate 42, and the other second to fifth layers 45 to 48 are the water absorbent polymer low body laminate 43. For the second layer 45 adjacent to the first layer 44, the volume ratio containing the water-absorbing polymer is higher than those of the third to fifth layers 46 to 48 which are the other water-absorbing polymer low-body laminates 43. Is high.
As a result, the absorbent body 41 is configured such that the absorption capacity gradually increases toward the liquid-impermeable sheet side, on the liquid-impermeable sheet side, that is, on the surface side in contact with the liquid diffusion sheet 13. The ability to absorb excretion is further improved.

At this time, in the first layer 44 that is the water-absorbing polymer high body laminate 42, the volume ratio (volume ratio) containing the water-absorbing polymer with respect to the volume of the water-absorbing polymer contained in the entire absorber is It is preferably about 25% to 50%.
When the volume ratio of the water-absorbing polymer contained in the first layer is less than 25%, the excretion liquid diffused by the liquid diffusion sheet 13 is reduced in the chance of transferring to the water-absorbing polymer, and thus the excretion liquid is efficiently collected. Cannot absorb. On the other hand, if it exceeds 50%, the pulp ratio in the blend layer which is an absorption core becomes too large on the front side and the skin side, and the excretion liquid stays on the skin side and is difficult to separate.
Further, the sum of the volume of the water-absorbing polymer contained in the first layer 44 and the second layer 45 adjacent to the first layer 44 is the same as the volume of the water-absorbing polymer contained in the entire absorbent body. It is preferable to set it as 50 to 80%. If the ratio is less than 50%, the excretion liquid diffused by the liquid diffusion sheet 13 in the two layers of the first layer 44 and the second layer 45 is reduced, so that the chance of transferring to the water-absorbing polymer decreases. There is a possibility that the absorption capacity expected by the combination of both the first and second layers 44 and 45 cannot be ensured and the excretory fluid cannot be absorbed efficiently. On the contrary, when it exceeds 80%, the ratio of the pulp fiber in the absorbent body becomes too large in the third to fifth layers 46 to 48, and the excretory fluid is in these third to fifth layers 46 to 48. Because it stays inside, there is a possibility that it will be difficult to remove water.

Here, for the absorbent body 41, when the cross section in the thickness direction is divided into five equal parts in the thickness direction, the volume ratio of the water-absorbing polymer of each layer divided into the five equal parts is, for example, the following method Measured in
Nondestructive 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 of the sample (in this case, 5 layers) 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 of what is shown in FIG. 9, the volume of the water-absorbing polymer contained in the first layer which is a superabsorbent polymer body stack is 35% with respect to the volume of the water-absorbing polymer contained in the entire absorber, This layer is 34%. The third layer was 18%, the fourth layer was 6%, and the fifth layer was 7%.
FIG. 9 shows that the volume ratio of the water-absorbing polymer increases toward the liquid-impermeable sheet side, that is, the first layer side. In addition, the sum of the volume of the water-absorbing polymer contained in the first layer and the second layer reaches 69% of the volume of the water-absorbing polymer contained in the entire absorbent body, and the liquid impermeability of the absorbent body. It can be seen that the absorbent capacity on the side of the conductive sheet is much higher than that on the side of the liquid-permeable sheet.

In addition, about formation of the absorber from which the volume of the water absorbing polymer to contain differs for every 1st-5th each layer as mentioned above, it is possible to form by arbitrary methods.
For example, as described above, a manufacturing apparatus (for example, disclosed in JP 2010-119655 A) that manufactures an absorbent body by laminating absorbent materials such as pulp fibers in a predetermined shape while mixing a water-absorbing polymer. Absorber manufacturing apparatus). And when the pulp fiber which comprises an absorber is laminated | stacked in the type | mold formed in the outer peripheral surface of the suction drum, so that a predetermined amount of water absorbing polymer may be supplied with respect to each of the first to fifth layers. By changing the supply position of the water-absorbing polymer to adjust the supply time of the water-absorbing polymer, or by changing the supply amount or supply timing of the absorbent polymer, the absorbent body having the above-described configuration is formed. Can do.

  In the second embodiment, except for the configuration of the absorber 41, particularly the configuration related to the volume ratio containing the water-absorbing polymer with respect to the volume of the entire absorber of the first to fifth layers 44 to 48, The configuration is basically the same as that of the first embodiment described above, and the same reference numerals are given to omit the detailed description in order to achieve the same effect.

The absorbent article of 2nd Embodiment which has the said structure can acquire the effect similar to the said 1st Embodiment fundamentally.
However, at least the first layer 44 located on the most liquid-impermeable sheet side is set to have the highest volume ratio containing the water-absorbing polymer with respect to the volume of the water-absorbing polymer contained in the entire absorbent body. By using the superposed water-absorbing polymer body laminate 42, the excretory liquid retained by the liquid diffusion sheet 13 can be moved and absorbed by the absorber 41 more efficiently.
As a result, the ability of the liquid diffusion sheet 13 to be repeatedly absorbed and diffused can be maintained for a long period of time, and the ability to absorb excretory liquid as the entire absorbent article can be further improved.

  Further, with respect to the absorbent body 41, the portion containing a large amount of the water-absorbing polymer generally tends to collapse, so the first layer 44 located closest to the liquid-impermeable sheet is the water-absorbing polymer high body laminate 42. If this is the case, the first layer 44 is considered to be weak against deformation and easily collapse. However, since the liquid diffusion sheet 13 is always in contact with the first layer 44 to reinforce, the first layer 44 is stably maintained in shape even if it is the water-absorbing polymer high body laminate 42. As a result, the liquid diffusion sheet 13 can reliably perform the shape retention of the entire absorbent body.

10 and 11 show a third embodiment of the absorbent article of the present invention. The absorbent article according to the third embodiment has a length in the width direction of the liquid diffusion sheet. This is different from the case of the first embodiment.
That is, in the first embodiment, the length in the width direction of the liquid diffusion sheet 13 is made smaller than the minimum width portion in the width direction of the absorber 12 (that is, the width of the curved portion of the crotch portion). However, the liquid diffusion sheet 51 in the third embodiment has a width-direction length smaller than the maximum width of the absorber 12 (that is, the width of the abdomen and the buttocks) and larger than the minimum width portion. doing.
Accordingly, in the range where the liquid diffusion sheet 51 is in contact with the absorber 12, the flange portion 21 bites into and adheres to the absorber 12, while the curved portion of the longitudinal portion of the absorber 12 A part of the liquid diffusion sheet 51 protrudes.
The absorber in the third embodiment uses the absorber 12 having the same configuration as that of the first embodiment, and in a range where the absorber 12 and the liquid diffusion sheet 51 are in contact with each other, The extent of biting of the collar portion 21 into the absorber 12 is the same as in the first embodiment.

  The length of the liquid diffusion sheet 51 in the width direction is smaller than the maximum width of the absorber 12 (that is, the width of the abdomen and the buttocks) and larger than the minimum width portion. By adopting an aspect in which a part of the liquid diffusion sheet 51 is extended from the impermeable sheet side, the excretion liquid that the absorber 12 could not absorb is absorbed and diffused, and the excretion liquid leaks to the outside. This is to more reliably deter the exit.

Explaining this point, the excretory fluid that the absorbent body 12 has not been able to absorb moves as it is to the liquid-impermeable sheet side, but in the minimum width portion of the absorbent body 12, the range in which the excreted fluid is absorbed becomes narrow. Therefore, liquid leakage to the outside is likely to occur. For example, as shown in FIG. 10, a portion corresponding to the wearer's crotch portion in the longitudinal portion of the absorbent body 12 has a shape curved toward the inner side of the absorbent body 12 in a plan view. In this case, this portion becomes the minimum width portion of the absorbent body 12, and liquid leakage to the outside of the excretion fluid is likely to occur compared to other portions.
Therefore, the length of the liquid diffusion sheet 51 in the width direction is made larger than the minimum width portion of the absorber 12 so that a part of the liquid diffusion sheet 51 protrudes from the absorber 12 in plan view. Thus, it is possible to quickly absorb and quickly diffuse the excretory fluid that the absorber 12 has not been able to absorb, thereby more reliably suppressing the excretory fluid from leaking to the outside.
On the other hand, even if the length of the liquid diffusion sheet 51 in the width direction is larger than the maximum width of the absorbent body 12, even if the excretory liquid is diffused in the longitudinal direction in the portion that protrudes from the absorbent body 12, the liquid diffusion sheet 51 protrudes. If there is no absorber that absorbs excretory fluid diffused in the longitudinal direction of the portion, the effect of improving the absorption capacity is small. Therefore, the length of the liquid diffusion sheet 51 in the width direction is made smaller than the maximum width of the absorber 12 to save resources by minimizing the amount of material used.

  In the third embodiment, the length of the liquid diffusion sheet 51 in the width direction is smaller than the maximum width of the absorber 12 and larger than the minimum width portion. Since the configuration is substantially the same as that of the first embodiment described above and the same effect is obtained, the same reference numerals are given and detailed description thereof is omitted.

The absorbent article of the third embodiment having the above configuration can basically obtain the same effects as those of the first embodiment.
In addition to this, the liquid diffusion sheet 51 is made smaller than the maximum width of the absorber 12 and larger than the minimum width portion so that the liquid diffusion sheet 51 is In the range where it contacts, the flange portion 21 bites into the absorbent body 12 and is always in close contact, and a part of the liquid diffusion sheet 51 extends from the liquid-impermeable sheet side of the absorbent body 12. . As a result, the liquid diffusion sheet 51 diffuses the excretory fluid that could not be absorbed by the absorber 12 and reliably absorbed into the abdomen side or the buttocks side of the absorber 12, so that the excreted fluid leaks to the outside. There is an advantage that can be more reliably suppressed.

  In the first to third embodiments, the liquid diffusion sheets 12 and 51, as shown in FIG. 4 and FIG. In the present invention, as shown in FIG. 12, it is possible to use a configuration in which the intervals between the flange portions are different from each other, or a configuration in which the widths of the flange portions 21 are different.

Furthermore, in the present invention, as a liquid diffusion sheet, as shown in FIG. 13, it extends in the longitudinal direction of the liquid diffusion sheets 13, 51 at the approximate center of the flange portion 21, and reaches the base 20 on the end surface on the absorber side. What formed the center area | region 21c in which the hollow 23 which is not formed was formed can be used.
The central region 21c is formed in the manufacturing process of the liquid diffusion sheets 13 and 51, and when the collar is formed by the steam jet, the pressure from the steam jet is shown in FIGS. 6 and 7. It is formed when it is larger than at the time of formation. 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. The depression in the central region is formed because adjacent protrusions having a curved shape collide with each other.

As described above, when the liquid diffusion sheets 13 and 51 have the central region 21c of the flange portion 21, the fiber-occupied cross-sectional ratio is lower than the surface side region 21a of the flange portion 21 while being higher than the inner region 21b. Is also expensive.
Specifically, the fibers occupied cross-sectional area ratio r ₁ of the base portion 20 at this time is 1.2R _O or more, the fiber occupied cross-sectional area ratio r ₂ of the surface area 21a of the ridge portion 21 is 0.8 R _O above, 1.2R less than _O, the center region 21c fibers occupied cross-sectional area ratio r ₄ of the ridges 21 is 0.5r _O or more and less than 0.8 r _O, the inner region 21b fiber occupied cross-sectional area ratio r ₃ of the ridges 21 Is preferably less than 0.5 r 2 _O. More preferably, the fibers occupied cross-sectional area ratio r ₁ of the base 20 1.2R _O to less than 2.0R _O, fibers occupied cross-sectional area ratio r ₂ of the surface area 21a of the ridge portion 21 is 0.8 R _O above, less than 1.2R _O, fibers occupied cross-sectional area ratio r ₄ of the central region 21c of the ridges 21 is 0.5r _O or more and less than 0.8 r _O, fibers occupied cross-sectional area ratio r ₃ of the inner region 21b of the ridges 21 0.1 r 2 _O or more and less than 0.5 r 2 _O.

In the first to third embodiments, the liquid diffusion sheets 13 and 51 include the base portion 20 and the surface side region 21a of the flange portion 21, the inner region 21b of the flange portion 21, and the center. In the region 21c, the fiber occupation cross-sectional area ratio is different.
However, the liquid diffusion sheet is provided with a base disposed on the liquid-impermeable sheet side and a plurality of ridges provided at regular intervals on the absorber side of the base, protruding to the absorber side and extending in the longitudinal direction of the absorber. And a groove portion formed between the adjacent flange portions and having a bottom portion formed by the base portion, and attached to the absorber in a state where the flange portion is bitten into the absorber. For example, the fiber-occupied cross-sectional area ratios of the surface side region, the inner region, and the central region of the base portion and the collar portion can be arbitrarily set.

Furthermore, in the first to third embodiments, the liquid diffusion sheets 13 and 51 have the flange portion 21 and the groove portion 22 continuously extending over the entire length in the longitudinal direction of the liquid diffusion sheets 13 and 51, respectively. Although formed, these ridges and grooves may be discontinuous in the longitudinal direction of the liquid diffusion sheet.
In addition, the liquid diffusion sheets 13 and 51 do not necessarily have to be raised at the portions in contact with the absorbers 12 and 41, and the presence or absence of raising can be arbitrarily selected.

  In the first to third embodiments, the bending rigidity in the longitudinal direction and the width direction of the liquid diffusion sheets 13 and 51 covers the liquid diffusion sheets 13 and 51 and the absorbers 12 and 41 together. Although it is set higher than the covering sheet 14, the bending rigidity of the liquid diffusion sheet can be arbitrarily set within a range in which the shape of the absorber can be reliably maintained.

  In the second embodiment, with respect to the configuration of the absorber 41, the volume ratio of the water-absorbing polymer contained in the second layer 45 adjacent to the first layer 44 is changed to other water-absorbing polymer low bodies. Set higher than the third to fifth layers 46 to 48 that are the laminate 43, and the sum of the volume of the water-absorbing polymer contained in the first layer 44 and the second layer 45 is included in the entire absorber. 50 to 80% of the volume of the water-absorbing polymer. However, the volume ratio of the water-absorbing polymer contained in each of the second to fifth layers in the absorber can be arbitrarily set.

For example, as shown in FIG. 14, the absorber 61 can be configured as follows.
That is, the first layer 62 located closest to the liquid-impermeable sheet among the first to fifth layers 62 to 66 obtained by dividing the cross section in the thickness direction of the absorber 61 into five equal parts in the thickness direction. Only the water absorbent polymer high body laminate 67 is used, while the other second to fifth layers 63 to 66 are used as the water absorbent polymer low body laminate 68.
And among the 2nd-5th layers 63-66 which are the said water-absorbing-polymer low body lamination | stacking 68, it is located in the 3rd layer 64 which is the center layer of the absorber 61, and the most liquid permeable sheet side. With respect to the fifth layer 66, the volume ratio of the water-absorbing polymer to the volume of the water-absorbing polymer contained in the entire absorbent body is set to the other water-absorbing polymer low body laminate, that is, the second layer. 63 and the volume ratio of the water-absorbing polymer contained in each of the fourth layers 65 is set higher.
The absorbent article shown in FIG. 14 is the same as that of the second embodiment except for the configuration of the absorber, and the same reference numerals are given to omit the description for the same effects.

Thus, the volume ratio of the water-absorbing polymer contained in the third layer 64 and the fifth layer 66 among the second to fifth layers 63 to 66 which are the water-absorbing polymer low-body laminates is changed to the other layers. The reason why the height is higher than that of the second and fourth layers 63 and 65 is that the third and fifth layers 64 and 66 have a function as a superabsorbent polymer stack in addition to a function as a superabsorbent polymer stack. This is to bring out the close function.
That is, since there are more pulp fibers than the first layer, which is a superabsorbent polymer superstructure laminate, while ensuring the diffusibility of excretory fluid in the absorber, the volume ratio of the superabsorbent polymer contained is relatively Since it is high, a certain amount of excretory fluid can be absorbed and retained.
In addition, by dispersing a plurality of layers having a relatively high volume ratio of the water-absorbing polymer to the volume of the water-absorbing polymer contained in the entire absorbent body, the water-absorbing polymer expands when wet with excretory fluid. It has the function to suppress blocking of the water-absorbing polymers associated with as much as possible, and to suppress the inhibition of excretion absorption due to the blocking. Here, the third layer and the fifth layer have a lower volume ratio of the water-absorbing polymer to be contained than the first layer which is a water-absorbing polymer high-body laminate. Is less likely to occur and the diffusibility of excretory fluids is less likely to be impaired.

Furthermore, as described above, when the water-absorbing polymer expands, the absorbent body as a whole is deformed, and in some cases, the absorbent body may be partially separated, which may cause a decrease in the absorption capacity of the absorbent body. Even in the case of the water-absorbing polymer low-body laminate as in the third and fifth layers, the amount of deformation can be reduced as a whole by dispersing and arranging the layer having a relatively high volume ratio of the water-absorbing polymer to be contained. There is also a function of reducing the absorption capacity of the absorber by reducing it as small as possible to suppress partial detachment of the absorber.
Moreover, since the volume ratio of the water-absorbing polymer to be contained is relatively high, the fifth layer can absorb water remaining in the covering sheet to some extent, so that the re-wetting can be performed. Can be reduced.

In addition, it is preferable that the volume of the water-absorbing polymer of the first layer 62 that is the water-absorbing polymer high-body laminate 67 is 33 to 50% of the volume of the water-absorbing polymer contained in the entire absorber 61.
Further, the volume of the water-absorbing polymer in the third layer 64 and the fifth layer 66 that are the water-absorbing polymer low layer laminate 68 is 25 to 33% of the volume of the water-absorbing polymer contained in the entire absorber. It is preferable that However, the volume ratio of the water-absorbing polymer contained in the water-absorbing polymer lower layer stack 68 is lower than the volume ratio of the water-absorbing polymer high-layer stack 67, and the total volume of the water-absorbing polymer contained in each layer is absorbed. It is contained in the whole body and does not exceed 100% of the volume of the water-absorbing polymer.
The third layer 64 and the fifth layer 66 do not have to have the same volume ratio of the water-absorbing polymer contained therein, and can be arbitrarily set within a range of 25 to 33%. In addition, the other layers that are the water-absorbing polymer low-body laminate 68, that is, the second and fourth layers 63 and 65 may contain little or no water-absorbing polymer.

Thus, the volume ratio of the water-absorbing polymer of the first layer 62 that is the water-absorbing polymer of the water-absorbing polymer high-body laminate 67 is 33 to 50%, and the volume of the water-absorbing polymer of the third and layers 64 and 66 is The reason why the ratio is set to 25 to 33% is as follows.
That is, when the volume ratio of the water-absorbing polymer of the third and fifth layers 64 and 66 exceeds the volume ratio of the water-absorbing polymer of the first layer 62, the water-absorbing polymer of the first layer 62 from the liquid diffusion sheet 13. This is because the chance of liquid transfer to the water is reduced. Further, the third layer 64 and the fifth layer 66 are likely to be blocked due to the expansion of the water-absorbing polymer, and the diffusibility of excretory liquid is also reduced, so that the absorption performance of the entire absorbent body may be impaired. It is because there is sex.

In addition, when the volume ratio of the water-absorbing polymer contained in the first layer 62 is less than 33% of the volume of the water-absorbing polymer contained in the entire absorbent body 61, In addition to less chance of excretory fluid transfer, the superiority of the absorption capacity with respect to the third and fifth layers 64 and 66 is reduced, and the absorption and retention function of the excretory fluid as a whole of the absorber 61 and diffusibility The balance may be lost. As a result, it becomes difficult to obtain a function of absorbing and holding excretory liquid expected as a superabsorbent polymer high-layer laminate, and as a result, the absorbent body 61 as a whole may not be able to ensure the necessary absorption performance.
Conversely, if it exceeds 50%, the ratio of the pulp fibers in the absorbent body 61 becomes too large in each layer of the water-absorbent polymer low-layer laminate 68, and the excreta remains concentrated in the first layer 62. There is a possibility that it will be difficult to separate water.

Furthermore, when the volume ratio of the water-absorbing polymer contained in the third and fifth layers 64 and 66 is less than 25% of the volume of the water-absorbing polymer contained in the entire absorbent body 61, the third and fifth layers. The opportunity of excretion fluid transfer to the water-absorbing polymer in each of the layers 64 and 66 is reduced, and the superiority of the absorption capacity in the third and fifth layers 64 and 66 with respect to other water-absorbing polymer low-body laminates May not be able to exhibit the function of absorbing and holding excretory fluids in accordance with the expected superabsorbent super absorbent laminate.
On the other hand, if it exceeds 33%, it may have a water absorption capacity equivalent to or higher than that of the superabsorbent polymer body, so that the balance between the absorption and retention function of the excretory fluid in the absorber 61 and the diffusibility is lost. On the other hand, there is a possibility that the necessary absorption performance cannot be secured for the entire absorber 61.

Moreover, in the said 2nd Embodiment, although the structure of the said absorber 41 makes only the 1st layer the water-absorbing polymer high body lamination | stacking among the 1st-5th layers, the 1st layer In addition, one to three of the second to fifth layers may be a water-absorbing polymer high-body laminate.
For example, as shown in FIG. 15, among the first to fifth layers 72 to 76 obtained by dividing the cross section in the thickness direction of the absorber 71 into five equal parts in the thickness direction, the most liquid-impermeable sheet side. While the first layer 72 located, the third layer 74 located in the middle of the absorber, and the fifth layer 76 located closest to the liquid-permeable sheet are used as the water-absorbing polymer high-body laminate 77, the others The second layer 73 and the fourth layer 75 are referred to as a water-absorbing polymer low body laminate 78.
At this time, the first, third, and fifth layers 72, 74, and 76 have the same basis weight, and the second and fourth layers 73 and 75 are the same as each other. The basis weight is about.
In addition, about FIG. 15, except the structure of an absorber, it is the same as that of the said 2nd Embodiment, and there exists the same code | symbol in order to show | play the same effect, Description is abbreviate | omitted.

As described above, the three layers of the first layer 72, the third layer 74, and the fifth layer 76 in the case where the absorber is divided into five layers are formed as the water-absorbing polymer high-body laminate 77. This is because the entire body is effectively utilized for absorption of excretory fluid.
As for the first layer 72, the liquid-impermeable sheet side of the absorbent body 71 that is in contact with the liquid diffusion sheet 13 is the water-absorbing polymer high-body laminate 77, as in the second embodiment. This is because the excretory liquid retained by the liquid diffusion sheet 13 is efficiently and stably moved toward the absorber 71. Thereby, since the excretion liquid which the liquid diffusion sheet 13 hold | maintains reduces early and reliably, the capability to diffuse excretion liquid recovers early, and can respond also to excretion of multiple times stably. .

Further, in addition to the first layer 72, the reason why the third layer 74 and the fifth layer 76 are the water-absorbing polymer high-body laminate 77 is that a plurality of water-absorbing polymer high-body laminates are dispersed and dispersed. This is to prevent blocking of the water-absorbing polymers accompanying the expansion of the water-absorbing polymer as much as possible when wetting with the excretory liquid, and to suppress inhibition of excretion liquid absorption due to the blocking.
Furthermore, when the water-absorbing polymer expands, the entire absorber is deformed, and in some cases, the absorber is partially separated, and the absorption capacity of the absorber may be reduced. This is also to prevent the excretory fluid from being absorbed and retained only in the first layer. Thereby, the amount of deformation of the absorber as a whole is made as small as possible to suppress a partial detachment of the absorber, and a decrease in the absorption capacity of the absorber is suppressed.
The reason why the fifth layer 76 is made of a water-absorbing polymer high-body layer is to absorb the water remaining on the covering sheet, thereby reducing rewetting.
On the other hand, in addition to the first layer 72, the third layer 74 and the fifth layer 76 are water-absorbing polymer high-body laminates, so that the second layer 73, which is a water-absorbing polymer low-body laminate, In the fourth layer 75, the pulp fiber is present more than the first, third, and fifth layers 72, 74, and 76, so that it is possible to improve the diffusibility of excretory fluid in the absorber. The effect of becoming is obtained.

The volume of the water-absorbing polymer contained in the first, third, and fifth layers 72, 74, and 76, which are the water-absorbing polymer high-body laminate, is the volume of the water-absorbing polymer contained in the entire absorbent body. The total volume of the water-absorbing polymer contained in each superabsorbent polymer body laminate is preferably 75% to 100% of the volume of the water-absorbing polymer contained in the entire absorbent body.
In particular, the volume ratio of the water-absorbing polymer contained in each of the first layer 72, the third layer 74, and the fifth layer 76 is contained in the entire absorbent body and is less than 25% of the volume of the water-absorbing polymer. The chance of excretory fluid transfer to the water-absorbing polymer of these first layer 72, third layer 74, and fifth layer 76 is significantly reduced. As a result, it may be difficult to obtain the function of absorbing and retaining the excretory fluid expected as a super absorbent polymer laminate, and as a result, it may not be possible to ensure the necessary absorption performance as a whole There is.
At this time, the second and fourth layers 73 and 75, which are laminated layers of the water-absorbing polymer low body, may be in a state where the water-absorbing polymer is hardly contained or not contained at all.

  Moreover, in the said 3rd Embodiment, although the thing of the same structure as 1st Embodiment is used as the absorber 12, in this invention, the absorber of 2nd Embodiment is used as an absorber. The absorber having the same configuration as 41 or the configuration shown in FIGS. 14 and 15 may be used.

  In the first to third embodiments, the case of a disposable paper diaper has been described as the absorbent article. However, the absorbent article of the present invention may be a sanitary napkin, an incontinence pad, or the like. There may be.

In order to confirm the absorbent capacity of the absorbent article of the present invention, a comparative experiment was performed to compare the absorbency of the absorbent article according to the present invention and the absorbent article not having the configuration of the present invention.
As a first example, the absorbent article according to the present invention is most liquid-impermeable when the cross section in the thickness direction of the absorbent body is divided into five equal parts in the thickness direction to form first to fifth layers. Absorption in which only the first layer located on the sheet side is a water-absorbing polymer high-body laminate, and a particularly large amount of water-absorbing polymer is contained in the first layer and the second layer adjacent to the first layer. Using the body. And the thing (henceforth "Example 1") which has the structure which has arrange | positioned the liquid diffusion sheet between the absorber and the liquid-impermeable sheet was used.
As a second example, the first layer of the absorber is a water-absorbing polymer high-body laminate, but the absorption ratio of the water-absorbing polymer contained in each layer is different from that of Example 1, and the absorption is performed. A liquid diffusion sheet provided between the body and the liquid-impermeable sheet (hereinafter referred to as “Example 2”) was used.

On the other hand, the absorbent article that does not have the configuration of the present invention, as a first example, the volume ratio of the water-absorbing polymer contained in each of the first to fifth layers is the same as in Example 2, The thing of the structure which uses the absorber from which the basic weight of the pulp fiber which comprises an absorber differs from Example 2, and does not have a liquid diffusion sheet (henceforth "the comparative example 1") was used.
As a second example, the volume ratio of the water-absorbing polymer contained in each of the first to fifth layers is the same as in Example 1, and the basis weight of the pulp fibers constituting the absorber is different from that in Example 1. A structure using an absorber and having no liquid diffusion sheet (hereinafter referred to as “Comparative Example 2”) was used.
As a third example, the volume ratio of the water-absorbing polymer contained in each of the first to fifth layers is the same as in Example 1, and the basis weight of the pulp fibers constituting the absorber is Example 1 and comparison. An absorbent body different from that of Example 2 and having no liquid diffusion sheet (hereinafter referred to as “Comparative Example 3”) was used.

Regarding Example 1, Comparative Example 2, and Comparative Example 3, the volume ratio of the water-absorbing polymer contained in each of the first to fifth layers to the water-absorbing polymer contained in the entire absorber is 35 in the first layer. %, The second layer is 34%, the third layer located in the center of the absorber is 18%, the fourth layer adjacent to the third layer is 6%, and is located on the most liquid-permeable sheet side. The fifth layer was 7%. Regarding the basis weight of the pulp fibers in the absorbent bodies of Example 1, Comparative Example 2, and Comparative Example 3, Example 1 is 170 g / m ² , Comparative Example 2 is 220 g / m ² , and Comparative Example 3 is 250 g / m ^2. It was.
Moreover, about the said Example 2 and the comparative example 1, the volume ratio of the water absorbing polymer which each layer of the 1st-5th layer with respect to the water absorbing polymer which the whole absorber contains is 25% for the first layer, The second layer was 22%, the third layer was 21%, the fourth layer was 20%, and the fifth layer was 12%. These examples 2, the basis weight of the pulp fibers in the absorbent of Comparative Example 1, Example 2 170 g / m ^2, Comparative Example 1 was 202 g / m ^2.
The basis weight of the water-absorbing polymer was 250 g / m ² in any of the examples and comparative examples.

Moreover, as a liquid diffusion sheet used in Example 1 and Example 2, NBKP (softwood bleached kraft pulp) 45%, rayon fiber (manufactured by Daiwabo Rayon Co., Ltd., trade name corona, grade 1.1 dtex × 8 mm length) What was formed with the wet spunlace nonwoven fabric (basis weight 55g / m < ² >) which consists of 25% and beating pulp 30% was used, and the fluff surface of the liquid diffusion sheet was arrange | positioned at the absorber. In addition, about the collar part, height (height from the bottom part of a groove part) was 0.4-0.8 mm, and the width | variety between adjacent collar parts was 2.0 mm.

  And about these Example 1 and Example 2, Comparative Example 1- Comparative Example 3, the absorptivity experiment described below is conducted, and about absorption time, liquid return amount (rewetting), and the diffusion length to a longitudinal direction, excretion Assuming that the liquid was discharged three times, the data for each time were acquired, and the absorption capacity was evaluated.

  In the absorbent test, for each absorbent article having a size of 300 mm in length, 100 mm in width, and 2.9 mm in thickness, the same component and a certain amount of artificial urine were injected into the center of the absorber. The absorption time of the artificial urine, the diffusion lengths on the liquid permeable sheet side (front surface) and the liquid impermeable sheet side (back surface), and the liquid return amount (rewetting 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) 80 mL of artificial urine is injected into the center of the absorber at 80 mL / 10 seconds from a 100 mL burette.
(3) Record the time from the start of artificial urine injection until the artificial urine in the U-shaped device disappears as the absorption time.
(4) Three minutes after the start of the experiment, record the outline of the area where the artificial urine spreads on the front and back surfaces of the absorber.
(5) 4 minutes after the start of the experiment, spread the absorber on an acrylic flat plate of 200 mm × 450 mm and let it stand. Then, the spread of artificial urine is measured on both the front and back surfaces and recorded as the diffusion length.
(6) Five minutes after the start of the experiment, 50 g of 100 mm × 100 mm filter paper is left on the absorber 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 start of the experiment, 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 taken as the liquid return amount.
(8) After 9 minutes from the start of the experiment, place the sample on the U-shaped instrument again.
(9) Ten minutes after the start of the experiment, the same steps as (2) to (8) are repeated again. This is repeated up to the third round, and each result is recorded.
The results are shown in Table 1.

As can be seen from Table 1, in Examples 1 and 2 and Comparative Examples 1 to 3, the absorption time and the diffusion length of the surface were almost the same, but Example 1 and Example 2 were rewet amounts. In the evaluation of the diffusion length on the back surface, better results were obtained than in Comparative Examples 1 to 3. That is, in Example 1 and Example 2, the amount of rewet was small and the diffusion length of the back surface was long as compared with Comparative Examples 1 to 3.
This is because Example 1 and Example 2 are provided with a liquid diffusion sheet, so that the artificial urine is efficiently diffused on the liquid-impermeable sheet side of the absorber, and the artificial urine is utilized using the entire absorber. It is thought that this is because it absorbs.
Further, even when artificial urine was injected three times, the results of the rewet amount and the diffusion length on the back surface were good, so in the liquid diffusion sheet, artificial urine diffused in the liquid diffusion sheet It is considered that the liquid diffusing function is restored relatively quickly by efficiently moving to the absorber side, and artificial urine is stably absorbed by the absorber.

  From the above, according to the present invention, it is possible to obtain a high absorption capacity by effectively and efficiently utilizing the entire absorbent body while sufficiently ensuring the ability to repeatedly diffuse the excretory liquid of the liquid diffusion sheet. Has been demonstrated.

1 Paper diaper (absorbent article)
DESCRIPTION OF SYMBOLS 10 Liquid-permeable sheet 11 Liquid-impermeable sheet 12,41,61,71 Absorber 13,51 Liquid diffusion sheet 14 Cover sheet 20 Base part 21 Base part 21a Surface side area 21b Inner area 22 Groove part 22a Bottom part of groove part 42 Water absorption High polymer stack 43 Water absorbent polymer low stack 44, 62, 72 First layer 45, 63, 73 Second layer 46, 64, 74 Third layer 47, 65, 75 Fourth layer 48, 66 , 76 5th layer

Claims (14)

A liquid-permeable sheet, a liquid-impermeable sheet, and an absorbent article having a long unidirectional absorber disposed between the liquid-permeable sheet and the liquid-impermeable sheet,
Between the absorber and the liquid-impermeable sheet, a liquid diffusion sheet formed of a nonwoven fabric containing cellulose fibers and extending in the longitudinal direction of the absorber is disposed,
The liquid diffusion sheet includes a base portion disposed on the liquid-impermeable sheet side, and a plurality of flange portions provided at regular intervals on the absorber side of the base portion, protruding toward the absorber side and extending in the longitudinal direction of the absorber. An absorber formed between adjacent flanges and having a bottom formed by a groove formed by the base and attached to the absorber in a state where the flange is bitten into the absorber. Sex goods.   In the liquid diffusion sheet, the base has a fiber-occupied cross-sectional area ratio higher than that of the collar part, and a surface-side area in the collar part is formed to have a fiber-occupied cross-sectional area ratio higher than an area inside the surface-side area. The absorbent article according to claim 1.   The absorbent article according to claim 1 or 2, wherein the liquid diffusion sheet has the flange and the groove formed continuously over the entire length in the longitudinal direction of the liquid diffusion sheet.   The absorbent article according to any one of claims 1 to 3, wherein at least a portion in contact with the absorber is raised in the liquid diffusion sheet.   The liquid diffusion sheet is covered with a covering sheet together with the absorber, and the bending rigidity in the longitudinal direction and the width direction of the liquid diffusion sheet is set higher than that of the covering sheet. 5. The absorbent article according to any one of 4.   6. The liquid diffusion sheet according to claim 1, wherein a length in a width direction of the liquid diffusion sheet is smaller than a maximum width portion in the width direction of the absorber and larger than a minimum width portion in the width direction of the absorber. Absorbent article according to item.   The absorber includes pulp fibers and a water-absorbing polymer, and the content of the water-absorbing polymer on the liquid-impermeable sheet side is larger than that on the liquid-permeable sheet side, and the liquid absorption amount on the liquid-permeable sheet side is increased. The absorbent article according to any one of claims 1 to 6, wherein the liquid absorption amount on the liquid-impermeable sheet side is larger than that of the absorbent article.   The absorbent body absorbs water with respect to the volume of the water-absorbing polymer contained in the entire absorbent body when the cross section in the thickness direction of the absorbent body is divided into 5 layers in the thickness direction to form five layers. A water-absorbing polymer high-body laminate formed with the highest volume fraction containing a water-soluble polymer, and a water-absorbing polymer lower-body laminate containing a lower volume fraction than the water-absorbent polymer high-body laminate, The water-absorbent article according to claim 7, wherein the first layer located on the impermeable sheet side is a water-absorbent polymer high-layer laminate.   Only the first layer is configured as a superabsorbent polymer body laminate, and the volume of the superabsorbent polymer contained in the first layer is 25 to 50% of the volume of the superabsorbent polymer contained in the entire absorber. The absorbent article according to claim 8, wherein   The sum of the volume of the water-absorbing polymer contained in the first layer and the second layer adjacent to the first layer is 50 to 80% of the volume of the water-absorbing polymer contained in the entire absorbent body. Item 10. The absorbent article according to Item 9.   Only the first layer is configured as a water-absorbing polymer high-body laminate, and the volume of the water-absorbing polymer contained in the first layer is 33 to 50% of the volume of the water-absorbing polymer contained in the entire absorber. And the water-absorbing polymer contained in each of the third layer, which is the central layer of the absorber, and the fifth layer located closest to the liquid-permeable sheet in the low-absorbent polymer low-layer laminate. The absorbent article according to claim 9, wherein the volume is 25 to 33% of the volume of the water-absorbing polymer contained in the entire absorbent body.   As for the said absorber, the said 1st layer, the 3rd layer which is the center layer of an absorber, and the 5th layer most located in the liquid-permeable sheet side are all the said water-absorbing-polymer high body lamination | stacking. The absorbent article according to claim 8, wherein   The volume of the water-absorbing polymer contained in each water-absorbing polymer body laminate is 25% or more of the volume of the water-absorbing polymer contained in the entire absorbent body, and is contained in each water-absorbing polymer body laminate. The absorbent article according to claim 12, wherein the total volume of the water-absorbing polymer is contained in the entire absorbent body and is 75% to 100% of the volume of the water-absorbing polymer.   The absorbent article according to any one of claims 1 to 10, wherein the absorbent body has a weight ratio of a water-absorbing polymer contained in the absorbent body of 0.5 or more.