JP7157560B2 - absorbent article - Google Patents

Description

TECHNICAL FIELD The present invention relates to absorbent articles such as disposable diapers, sanitary napkins, panty liners, and incontinence pads, and more specifically, it comprises an upper absorbent body and a lower absorbent body, the upper absorbent body extending in the longitudinal direction and extending in the width direction. The present invention relates to an absorbent article having an absorbent body intermittently arranged over a plurality of strips.

Conventionally, as the absorbent article, between a liquid-impermeable back sheet such as a polyethylene sheet or a polyethylene sheet laminated nonwoven fabric and a liquid-permeable top sheet such as a nonwoven fabric or a liquid-permeable plastic sheet, It is known to interpose an absorbent body holding a superabsorbent polymer in the body.

In recent years, in addition to the ability to reliably absorb and retain excreted bodily fluids, the absorbent body is required to be thin, comfortable to wear, and less prone to regurgitation after absorption.

As an absorbent article having such an absorbent body, Patent Document 1 below discloses an absorbent body having a groove portion forming an opening on at least one surface, and a surface of the groove portion perpendicular to the thickness direction of the absorbent body. It is disclosed that the width of the opening in the body is made smaller from one side to the other side to make it easier to bend in response to changes in the body shape and posture of the wearer and to improve fit.

Further, in the following Patent Document 2, the central region of the absorbent body width direction of the excretory part facing part has a coarse and dense structure of fibers, and the lateral regions in the absorbent body width direction located on both left and right sides of the central region are The portion facing the excretory portion includes a low-density portion having the lowest density, and the sparse-dense structure of the fibers includes a medium-density portion having a higher density than the low-density portion and a high-density portion having a higher density than the medium-density portion. The medium-density portion and the high-density portion are each formed to extend in the longitudinal direction of the absorbent body, and in the coarse-density structure of the fibers, a plurality of the medium-density portions and a plurality of fibers By providing the absorbent bodies alternately arranged in the width direction of the absorbent body, the high-density portion enhances the ability to draw liquid from the topsheet to the absorbent body, makes it difficult for liquid to remain on the topsheet, and reduces the risk of liquid residue on the napkin. It is disclosed that a highly dry feeling can be obtained at the time of use.

Japanese Patent Publication No. 2010-273842 JP 2011-120698 A

However, in the absorbent articles described in Patent Documents 1 and 2, since the composition of the absorbent body in the thickness direction is almost uniform, it must be formed with a certain thickness in order to secure a sufficient absorption amount. In addition to the fact that the thickness cannot be reduced, the pulp fibers have a low liquid retention capacity, so there is a possibility that the absorber will return after absorbing the liquid.

Generally, it is known that by reducing the content ratio of pulp fibers and increasing the content ratio of superabsorbent polymer, the absorber can be made thinner, the feeling of wearing can be improved, and reversion can be improved. For this reason, in conventional absorbent articles, an absorber consisting of a two-layer structure of an upper absorbent body and a lower absorbent body is used, the amount of pulp fibers in the upper absorbent body is reduced as much as possible, and the content ratio of the superabsorbent polymer is By increasing

However, in an absorbent article with such a structure, the absorption speed of the superabsorbent polymer is slow, so when a large amount of body fluid is discharged at once, there is a problem that the body fluid overflows on the surface and leaks easily. . In particular, during repeated drainage, the superabsorbent polymer absorbs water and swells with the previous drainage, narrowing the gaps between particles and causing so-called gel blocking, in which the liquid cannot pass, resulting in a significant absorption speed. As a result, there is a problem that body fluid overflows on the surface and leakage is likely to occur.

In addition, in order to prevent gel blocking in the upper absorbent body, it is conceivable to provide an opening in a portion corresponding to the body fluid discharge part of the upper absorbent body. When body fluid is discharged to the position, it cannot be absorbed quickly, and there is a possibility that the absorption speed becomes slow.

SUMMARY OF THE INVENTION Accordingly, the main object of the present invention is to provide an absorbent article that more reliably increases the absorption speed, prevents reversion, and improves wearing comfort by reducing the thickness of the absorbent article.

In order to solve the above problems, the present invention according to claim 1 includes a lower absorbent body containing pulp fibers and a super absorbent polymer, and a lower absorbent body disposed on the skin side of the lower absorbent body and containing pulp fibers and a super absorbent polymer. An absorbent article comprising an absorbent body consisting of an upper absorbent body,
The upper-layer absorbent body extends along the longitudinal direction and is intermittently arranged over a plurality of strips at intervals in the width direction, and the content ratio of the superabsorbent polymer in the upper-layer absorbent body is the lower-layer absorbent body. is higher than the content ratio of the superabsorbent polymer in
In the lower absorbent body, leg-surrounding notches are formed by notching both sides of the lower-layer absorbent body corresponding to the wearer's crotch,
The upper absorbent body is arranged between the leg-surrounding cutouts of the lower absorbent body, and is positioned in front of the leg-surrounding cutouts on both sides of the lower absorbent body including the leg-surrounding cutouts. and spaced apart on the rear side .

In the invention according to claim 1, the upper layer absorbent bodies extend along the longitudinal direction and are intermittently arranged in a plurality of strips with spaces in the width direction. Body fluids easily flow into the lower absorbent body through the gaps formed in the upper layer. In the lower layer absorbent body, the content ratio of the super absorbent polymer is set lower than the content ratio of the super absorbent polymer in the upper layer absorbent body. In addition, the absorbed body fluid is easily diffused inside the lower absorbent body. Therefore, the body fluid absorption speed can be increased.

In addition, by making the content ratio of the super absorbent polymer in the upper absorbent body higher than the content ratio of the super absorbent polymer in the lower absorbent body, the water retention capacity of the skin-contacting side is increased, so that the lower absorbent body can It is possible to prevent the absorbed body fluid from returning back after absorption.

Furthermore, since the content ratio of the superabsorbent polymer is high and the content ratio of pulp fibers is low in the upper absorbent body, the thickness of the absorbent body is reduced, and the wearing comfort can be improved.

On the other hand, the lower-layer absorbent body is formed with leg-surrounding notches formed by notching both sides in a portion corresponding to the wearer's crotch,
The upper absorbent body is arranged between the leg-surrounding cutouts of the lower absorbent body, and is positioned in front of the leg-surrounding cutouts on both sides of the lower absorbent body including the leg-surrounding cutouts. and rearward, respectively.

In the case where leg-surrounding cutouts are formed on both sides of the lower absorbent body, the upper absorbent body is arranged between the leg-surrounding cutouts of the lower absorbent body, and the leg-surrounding cutouts are formed on the upper absorbent body. On both sides of the lower layer absorbent body including the lower layer absorbent body, the upper absorbent body is arranged separately on the front side and the rear side of the leg circumference notch, respectively, so that the water retention capacity of this part on the side of the skin contacting surface is increased, and the lower layer absorbent It is possible to prevent the body fluid absorbed by the body from returning after absorbing the fluid.

As the present invention according to claim 2, the content ratio (X) of the superabsorbent polymer in the upper layer absorbent body is 50 to 90% by weight, and the content ratio (Y) of the superabsorbent polymer in the lower layer absorbent body is 5 to 50% by weight, and the difference (XY) between the content ratio of the superabsorbent polymer in the upper layer absorbent body and the content ratio of the superabsorbent polymer in the lower layer absorbent body is 10 to 85. An absorbent article as described is provided.

In the invention according to claim 2, by specifying the content ratio of the superabsorbent polymer in the upper layer absorbent body and the lower layer absorbent body, and by defining the difference between these content ratios, the absorption speed is improved and the reversion is prevented. This ensures that the effects are well-balanced.

According to a third aspect of the present invention, the upper absorbent body is arranged over the entire length of the lower absorbent body, and the gap formed between adjacent upper absorbent bodies is continuous over the entire length of the lower absorbent body. An absorbent article according to any one of claims 1 and 2 is provided.

In the invention according to claim 3, the upper-layer absorbent bodies are arranged over the entire length of the lower-layer absorbent bodies, and the gap formed between the adjacent upper-layer absorbent bodies is continuous over the entire length of the lower-layer absorbent bodies. Therefore, even if the excretion position deviates slightly depending on the wearer's body shape and posture, the position of the absorbent article, etc., the body fluids pass through the gaps between the adjacent upper layer absorbent bodies and enter the lower layer absorbent body. It is easier to transition quickly, and it will be possible to increase the absorption speed more reliably.

According to a fourth aspect of the present invention, the upper layer absorbent core arranged between the leg-surrounding cutouts is arranged along the longitudinal direction in the center of the width direction of the lower absorbent core, and each side thereof has one absorbent core. Alternatively, the absorbent article according to any one of claims 1 to 3 is provided in which a plurality of strips are arranged .

In the invention according to claim 4 , although no gap is formed in the central portion in the width direction of the absorbent body, the body fluid passes through the gap portions formed on both sides of the upper absorbent body mainly arranged in the central portion in the width direction. can migrate to the lower layer absorbent.

As described in detail above, according to the present invention, it is possible to more reliably increase the absorption speed, prevent reversion, and improve the feeling of wearing by reducing the thickness.

1 is a partially broken development view of a pad 1 according to the present invention; FIG. FIG. 2 is a view taken along line II-II of FIG. 1; FIG. 2 is a view taken along line III-III in FIG. 1; 2 is a plan view of an absorbent body 4; FIG. FIG. 5 is a view taken along line VV in FIG. 4; FIG. 5 is a view taken along line VI-VI in FIG. 4; It is a top view of the absorber 4 which concerns on a modification. FIG. 8 is a view taken along line VIII-VIII of FIG. 7; FIG. 8 is a view taken along line IX-IX in FIG. 7; Fig. 2 is a perspective view showing a continuous body 10A of lower absorbent bodies and a continuous body 11A of upper absorbent bodies;

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

<An example of the basic structure of the pad>
The pad 1 according to the present invention is a pad such as a urine absorption pad that is attached to the skin contact surface of underwear, disposable diapers, etc., and as shown in FIGS. 2, a surface sheet 3 that forms a skin-contacting surface and allows urine and the like to quickly permeate, an absorbent body 4 interposed between these sheets 2 and 3, and the outermost surface (non-skin-contacting surface) of the pad 1. ), and right and left sides protruding to the skin side within a predetermined section in the front-rear direction including at least the wearer's urination opening, with the substantially side edge portion of the absorbent body 4 as the standing base end. It is mainly composed of a pair of three-dimensional gathers BS, side nonwoven fabrics 6, 6 forming BS, and around the absorbent body 4, at the upper and lower edges, the leak-proof sheet 2, the surface sheet 3, and the exterior sheet 5 Leakage-proof sheet 2 and surface sheet 3 whose outer edges are joined by a joining means such as hot melt adhesive, heat sealing, or ultrasonic sealing, and both side edges of which extend laterally beyond absorber 4. , the exterior sheet 5 and the side non-woven fabric 6 are joined by a joining means such as an adhesive such as hot melt, heat sealing, or ultrasonic sealing.

The leak-proof sheet 2 is made of a sheet material having at least water impermeability, such as polyethylene, but in recent years, there is a tendency to use a material having moisture permeability from the viewpoint of preventing stuffiness. The water-impervious/moisture-permeable sheet material is produced by melting and kneading an inorganic filler into an olefin resin such as polyethylene or polypropylene to form a sheet, and then stretching the sheet uniaxially or biaxially. A sheet is preferably used. As the leak-proof sheet 2, a poly-laminated nonwoven fabric obtained by laminating a plastic film and a nonwoven fabric may be used.

Next, for the surface sheet 3, a perforated or non-perforated nonwoven fabric, a porous plastic sheet, or the like is preferably used. The material fibers that make up the nonwoven fabric include synthetic fibers such as olefins such as polyethylene or polypropylene, polyesters, and polyamides, as well as recycled fibers such as rayon and cupra, and natural fibers such as cotton. A nonwoven fabric obtained by an appropriate processing method such as a method, a spunbond method, a thermal bond method, a meltblown method, a needle punch method, or the like can be used. Among these processing methods, the spunlace method is superior in flexibility and drapeability, and the thermal bond method is superior in bulkiness and compression recovery. When a large number of through holes are formed in the surface sheet 3, body fluids are rapidly absorbed, and the dry touch property is excellent. The fibers of the non-woven fabric may be either long fibers or short fibers, but preferably short fibers are used in order to produce the feel of a terry cloth. Also, in order to facilitate embossing, it is preferable to use olefin fibers such as polyethylene or polypropylene having a relatively low melting point. In addition, composite fibers of core-sheath type fibers, side-by-side type fibers, and split type fibers having a high melting point fiber as a core and a low melting point fiber as a sheath can also be preferably used.

The exterior sheet 5 covers the leak-proof sheet 2 and makes the outer surface of the pad 1 look and feel like cloth. The exterior sheet 5 is preferably made of nonwoven fabric. In addition to synthetic fibers such as olefins such as polyethylene or polypropylene, polyesters, polyamides, etc., recycled fibers such as rayon and cupra, and natural fibers such as cotton can be used as the material fibers, and the processing method is the spunlace method. , a spun bond method, a thermal bond method, an air through method, a needle punch method, or the like. However, spunbond nonwoven fabric, SMS nonwoven fabric, SMMS nonwoven fabric, or other long-fiber nonwoven fabric is preferable in that both feel and strength can be achieved.
The nonwoven fabric can be used singly or in a plurality of layers. When using a plurality of layers, the nonwoven fabrics are preferably fixed to each other with an adhesive such as hot melt. When non-woven fabric is used, the fiber basis weight is preferably 10 to 50 g/m ² , particularly 15 to 30 g/m ² .

One or more temporary fixing layers (not shown) are formed on the non-use side (outer surface) of the exterior sheet 5 to fix the pad 1 to underwear, disposable diapers, etc. when worn on the body. there is As the temporary fixing layer, a mechanical bonding type hook material may be used, or an adhesive may be used.

In the illustrated example, the exterior sheet 5 has a width slightly wider than that of the polymer sheet 4, and both side portions extend to the skin side of the top sheet 3 so as to involve the side edges of the leak-proof sheet 2 and the top sheet 3. The side non-woven fabric 6 extending from the surface of both sides of the top sheet 3, specifically urine, permeates the outer surface side of the exterior sheet 5 extending to the skin side on the outer side of the top sheet 3 in the width direction. A side nonwoven fabric 6 made of a nonwoven fabric material subjected to appropriate water-repellent treatment or hydrophilic treatment is provided according to the purpose of preventing water from slipping or improving the feel of the skin. As the side non-woven fabric 6, it is possible to use natural fibers, synthetic fibers, regenerated fibers, or the like, and those formed by an appropriate processing method can be used. For this reason, it is preferable to use a nonwoven fabric with a reduced basis weight and air permeability. Specifically, it is desirable to use a non-woven fabric with a basis weight of 13 to 23 g/m ² , and in order to reliably prevent permeation of body fluids, silicone-based, paraffin-based, alkylchromic chloride-based water repellents, etc. A water-repellent nonwoven fabric coated with is preferably used.

The inner side portion of the side nonwoven fabric 6 is folded back almost double, and one or a plurality of fibers are fixed in the middle portion in the height direction inside the double sheet at both ends or at appropriate positions in the longitudinal direction, In the illustrated example, three thread-like elastic elastic members 7, 7, . . . As shown in FIG. 3, the double sheet portion is folded once outward at the front and back ends and adhered to the absorbent body 4 side in a laminated state, thereby providing a front and back portion including at least the wearer's urination opening. As shown in FIG. 2, a left and right pair of three-dimensional gathers BS, BS standing on the skin side are formed in a predetermined section in the direction.

<Absorber>
The absorbent body 4 interposed between the leak-proof sheet 2 and the topsheet 3 comprises a lower absorbent body 10 containing pulp fibers and a superabsorbent polymer, and a lower absorbent body 10 disposed on the skin side of the lower absorbent body 10 and containing pulp fibers. and an upper absorbent body 11 containing a superabsorbent polymer, and has a function of absorbing and retaining body fluids. The absorbent body 4 is preferably surrounded by a core wrap sheet 8 made of nonwoven fabric, crepe paper, or the like, as shown in the drawings.

The lower absorbent core 10 is mainly composed of pulp fibers and a superabsorbent polymer, and is arranged adjacent to the non-skin contact side of the upper absorbent core 11 . The superabsorbent polymer is mixed in the pulp fibers constituting the lower absorbent body 10, for example, in the form of granular powder, and held between the fibers of the pulp fibers. The pulp fibers include cellulose fibers such as chemical pulp and dissolving pulp obtained from wood, and artificial cellulose fibers such as rayon and acetate. Softwood pulp with a longer fiber length is more functional than hardwood pulp. And it is preferably used in terms of price.

Examples of the superabsorbent polymer include a crosslinked polyacrylate, a self-crosslinked polyacrylate, a saponified product of a crosslinked acrylic acid ester-vinyl acetate copolymer, a crosslinked isobutylene/maleic anhydride copolymer, Polysulfonate cross-linked products, and products obtained by partially cross-linking water-swellable polymers such as polyethylene oxide and polyacrylamide are exemplified. Of these, acrylic acid or acrylate-based agents are preferred because of their excellent water absorption and water absorption rate. In the production process of the superabsorbent polymer having water absorption ability, the water absorption capacity and water absorption rate can be adjusted by adjusting the crosslink density and the crosslink density gradient.

The basis weight of pulp fibers in the lower absorbent body 10 is preferably 50 to 300 g/m ² , preferably 80 to 220 g/m ² , and the basis weight of the superabsorbent polymer is 30 to 180 g/m ² , preferably. should be 50 to 160 g/m ² . The basis weight is calculated by measuring the weight of a test piece cut into a square of 50×50 mm and dividing it by the area (the same applies hereinafter). The basis weight of these pulp fibers and superabsorbent polymer does not need to be constant, and may be changed depending on the part of the absorbent. For example, in the area corresponding to the bodily fluid discharge part H of the wearer, a high absorbent part is formed by increasing the basis weight of the pulp and the super absorbent polymer, or between the adjacent upper absorbent bodies 11, 11 as described later in detail. In the portion overlapping with the gap portion 13 formed in the upper layer absorbent core 11 or the portion where the upper absorbent core 11 is not laminated, the superabsorbent polymer basis weight may be lowered and the pulp fiber basis weight may be increased in order to improve the ability to draw in body fluids. . The bodily fluid discharge part H is a part mainly corresponding to the wearer's urination opening. It is the region of the width direction central portion on the front side from the longitudinal direction central portion of the portion where the leg circumference notch portions 12 described later are formed on both sides.

Also, the content ratio (Y) of the superabsorbent polymer in the lower absorbent body 10 is preferably 5 to 50% by weight, preferably 10 to 40% by weight, and more preferably 10 to 30% by weight. The content ratio is the ratio of the weight of the superabsorbent polymer contained in the lower absorbent core 10 to the total weight of the lower absorbent core 10 . Therefore, when the lower absorbent body 10 is composed of pulp fibers and superabsorbent polymers, if the content ratio of the superabsorbent polymer in the lower absorbent body 10 is 20% by weight, the remaining 80% by weight is pulp fibers. . In the lower absorbent body 10, by keeping the content ratio of the superabsorbent polymer low, a large amount of pulp fiber is blended. improves the diffusion of body fluids in the

The thickness of the lower absorbent body 10 is preferably 1.5 to 3.5 mm, preferably 2.0 to 3.0 mm. If it is smaller than 1.5 mm, the body fluid absorption capacity is small, and when a large amount of body fluid is discharged at once, there is a risk that it will overflow onto the surface. On the other hand, if it is thicker than 3.5 mm, the absorber 4 cannot be made thin, and the wearing feeling deteriorates. The thickness was measured by a constant pressure thickness measuring device digital type FFD-7 manufactured by Ozaki Seisakusho (the same applies hereinafter).

The density (average density) of the lower absorbent body 10 is preferably 0.02 to 0.35 g/cm ³ . If it is less than 0.02 g/cm ³ , the speed of absorption of body fluids is improved, but since the inter-fiber voids are large, capillary action is less likely to occur, and the diffusibility of fluids inside the absorbent body is reduced. On the other hand, if it is more than 0.35 g/cm ³ , the absorption speed at the initial stage of body fluid absorption will be low. The density is obtained by measuring the thickness T0 at a pressure of 0.5 gf/cm ² using a KES compression tester manufactured by Kato Tech Co., Ltd., and calculating the basis weight/T0 (the same applies hereinafter).

Synthetic fibers may be mixed in the lower absorbent body 10 . For the synthetic fibers, for example, polyolefins such as polyethylene or polypropylene, polyesters such as polyethylene terephthalate and polybutylene terephthalate, polyamides such as nylon, and copolymers thereof can be used. A mixture may also be used. In addition, composite fibers such as core-sheath type fibers, side-by-side type fibers, and split type fibers having a high-melting-point fiber as a core and a low-melting-point fiber as a sheath can also be used. In the case of hydrophobic fibers, the synthetic fibers are preferably surface-treated with a hydrophilizing agent so as to have affinity for body fluids.

The lower absorbent core 10 is arranged continuously over substantially the entire surface of the absorbent core 4 and constitutes substantially the outer edge of the absorbent core 4 in plan view. As for the planar shape of the lower absorbent core 10, any known shape can be widely adopted as long as it is vertically long in the front-rear direction. As shown in FIG. By forming a pair of leg-surrounding notches 12, 12 that are notched inwardly in an arcuate, trapezoidal, or triangular shape, the leg-surrounding notches 12, 12 are constricted in the width direction. In addition, it is preferable to form it in a substantially hourglass shape when viewed from above.

The upper-layer absorbent body 11 arranged adjacent to the skin-contacting side of the lower-layer absorbent body 10 is composed of pulp fibers and a superabsorbent polymer. The superabsorbent polymer is mixed in the pulp fibers constituting the upper absorbent body 11, for example, as granular powder. As the pulp fiber and superabsorbent polymer, those mentioned in the description of the lower absorbent body 10 can be used without limitation.

The basis weight of the pulp fibers in the upper absorbent body 11 is 5 to 150 g/m ² , preferably 30 to 100 g/m ² , and the basis weight of the superabsorbent polymer is 50 to 250 g/m ² , preferably. should be 100 to 200 g/m ² .

Also, the content ratio (X) of the superabsorbent polymer in the upper absorbent body 11 is preferably 50 to 90% by weight, preferably 60 to 90% by weight, and more preferably 70 to 90% by weight. If it is less than 50% by weight, the water retention capacity of the upper layer absorbent body 11 is too small, and body fluid absorbed by the lower layer absorbent body 10 may return to the skin side. On the other hand, when it is more than 90% by weight, the superabsorbent polymer tends to feel grainy on the skin at the time of wearing, and the feeling of wearing deteriorates. breakage and detachment of the superabsorbent polymer.

The difference (XY) between the content ratio (X) of the superabsorbent polymer in the upper layer absorbent body 11 and the content ratio (Y) of the superabsorbent polymer in the lower layer absorbent body 10 is 10 to 85, preferably It should be 20-80, more preferably 40-80. As a result, the absorption speed of body fluid in the lower absorbent body 10 and the effect of preventing backflow in the upper absorbent body 11 are exhibited in a well-balanced manner. The difference (X−Y) is the numerical value (unit: weight %) of the superabsorbent polymer content ratio (X) in the upper layer absorbent body 11 and the superabsorbent polymer content ratio (Y ) is simply subtracted from the numerical value (unit: weight %).

The thickness of the upper absorbent body 11 is 0.5 to 1.5 mm, preferably 0.75 to 1.25 mm. If the thickness is less than 0.5 mm, the body fluid absorption capacity is small, and there is a risk that it will not be possible to prevent the body fluid absorbed by the lower absorbent core 10 from returning to the skin side. On the other hand, if the thickness is more than 1.5 mm, the absorber 4 cannot be made thin, and the wearing feeling deteriorates.

The density (average density) of the upper absorbent body 11 is preferably 0.05 to 1.0 g/cm ³ .

As shown in FIGS. 4 to 6, the upper absorbent core 11 is arranged on the skin side surface of the lower absorbent core 10 so as to extend in the longitudinal direction and intermittently extend in a plurality of rows in the width direction. . That is, a plurality of upper layer absorbent bodies 11 having a predetermined width are arranged on the skin side surface of the lower layer absorbent body 10 at predetermined intervals, so that they are arranged in a vertical stripe pattern as a whole.

Between adjacent upper layer absorbent bodies 11 , 11 , gaps 13 where no upper layer absorbent body 11 exists are formed. In the gap 13 , the upper absorbent core 11 is not laminated on the skin side surface of the lower absorbent core 10 , and the lower absorbent core 10 is arranged facing the topsheet 3 . That is, in the gap 13 , the body fluid excreted on the skin side can be absorbed by the lower absorbent body 10 without passing through the upper absorbent body 11 .

The upper absorbent core 11 is arranged over the entire length of the lower absorbent core 10, and a gap 13 formed between adjacent upper absorbent cores 11, 11 is continuously provided over the entire length of the lower absorbent core 10. It is desirable to be able to In other words, the band-shaped upper absorbent core 11 formed to have a substantially equal width is continuously arranged between the front edge and the rear edge of the lower absorbent core 10, so that the adjacent upper absorbent cores 11, A gap 13 of approximately equal width formed between the lower absorbent cores 11 is continuously formed between the front edge and the rear edge of the lower absorbent core 10 . In this way, since the gap 13 is provided continuously over the entire length of the lower absorbent body 10, even if the excretion position of the body fluid deviates slightly in the front-rear direction, the same effect of body fluid absorption can always be obtained. become. In addition, since the gap portion 13 recessed from the upper layer absorbent bodies 11, 11 on both sides is formed over the entire length of the absorbent body 4, when attaching the present pad 1 to the inner surface of an outer such as a paper diaper, the pad 1 can be touched by hand. Alternatively, the center position of the pad 1 can be easily confirmed visually, and the gap 13 can be used as a guide to securely attach the pad 1 to the central portion in the width direction of the outer. In particular, since the gap 13 is formed up to the front and rear ends of the absorbent body 4, if the front and rear ends of the gap 13 are aligned with the center of the outer in the width direction, the pad 1 can be Since it can be attached to the center of the outer in the width direction over the entire length, alignment during attachment is extremely easy.

The width A per line of the upper layer absorbent body 11 is arbitrary as long as it can be arranged in a plurality of lines while forming the gap 13 between the leg circumference cutouts 12, 12 of the lower layer absorbent body 10. 10 to 40 mm is preferable. Further, the plurality of upper layer absorbent bodies 11 may all be formed with the same width. The upper absorbent body 11 may be formed with different width dimensions depending on the location, such as widening.

The width B of the gap 13 is preferably 10 to 30 mm. If it is smaller than 10 mm, it is difficult for body fluids to pass through the gaps 13 and transfer to the lower absorbent core 10. If it is larger than 30 mm, body fluids absorbed by the lower absorbent core 10 tend to flow back through the gaps 13 to the skin side. Become.

As an embodiment in which the leg-surrounding notches 12, 12 are formed on both sides of the lower absorbent body 10, the upper absorbent body 11 has the leg-surrounding notches as shown in FIG. It can be arranged on the inner side in the width direction of the portions 12 , 12 and not arranged on both sides of the lower absorbent body 10 including the leg-surrounding cutouts 12 . That is, the upper absorbent core 11 is arranged only between the leg-surrounding notches 12 of the lower absorbent core 10 . As a result, portions of the lower absorbent core 10 where the upper absorbent core 11 is not laminated on the skin side are provided on both sides of the region before and after the cutout portion 12 around the leg. 3, when bodily fluids flow outward in the width direction of the upper absorbent body 11, they are quickly absorbed by the lower absorbent body 10, and leakage of bodily fluids can be prevented. On the other hand, in the crotch area where body fluids easily diffuse, the upper layer absorbent body 11 is laminated along the longitudinal direction on the skin side of the lower layer absorbent body 10. It is possible to prevent the body fluid absorbed by the absorbent body 10 from returning to the skin side.

In the embodiment shown in FIG. 4, the upper absorbent core 11 is intermittently arranged in two strips at the center in the width direction of the lower absorbent core 10, and the upper absorbent core 11 is arranged at the center in the width direction of the lower absorbent core 10 in the longitudinal direction. A single gap 13 is formed continuously over the entire length of. By forming the gap part 13 in the central part in the width direction, it is possible to increase the body fluid absorption speed at a position close to the body fluid discharge part of the wearer.

As shown in FIGS. 4 and 5, the upper-layer absorbent body 11 is preferably arranged such that the widthwise outer edge substantially coincides with the widthwise inner edge of the leg-surrounding notch 12 . preferable. As a result, the area of the upper absorbent core 11 arranged between the leg cutouts 12, 12 can be increased as much as possible, and the water absorption capacity can be ensured, and the leg cutouts 12 of the lower absorbent core 10 can be secured. Since body fluids diffused in the vicinity of are absorbed by the upper absorbent body 11 arranged on the side of the skin, leakage from the edges of the cutouts 12 around the legs can be reliably prevented.

The upper absorbent body 11 has a widthwise outer profile line formed by a straight line extending along the longitudinal direction. preferably placed in contact with the top of the That is, by not forming the outline of the outer side in the width direction of the upper layer absorbent body 11 in a shape that bulges inward along the outline of the cutouts 12 around the legs, the absorbent body 4 around the legs is easily deformed. At the same time, since the lower absorbent core 10 having a high pulp fiber content fits easily around the legs, the wearing comfort is improved.

The upper absorbent bodies 11 can be arranged in various patterns. For example, as shown in FIGS. 7 to 9, it may be arranged not only between the leg cutouts 12, 12 but also on both sides of the lower absorbent core 10 including the leg cutouts 12. good. At this time, on both sides of the lower absorbent core 10 including the leg cut-outs 12, it is preferable to arrange them on the front side and rear side of the leg cut-outs 12 so as to be spaced apart from each other. By arranging the upper layer absorbent body 11 on both sides of the lower layer absorbent body 10 including the leg-surrounding cutouts 12, it is possible to increase the water retention capacity of this part on the side of the skin contacting surface. Absorbed body fluid can be prevented from returning after absorption.

In addition, the upper absorbent core 11 arranged between the leg-surrounding cutouts 12, 12 is arranged along the longitudinal direction in the central portion in the width direction of the lower absorbent core 10, and one or more strips are arranged on each side thereof. You may arrange it. As a result, the gap 13 is not formed in the central portion of the absorbent body 4 in the width direction, but the body fluid passes through the gaps 13, 13 formed on both sides of the upper absorbent core 11 mainly arranged in the central portion in the width direction. can migrate to the lower absorbent core 10.

Next, a method for manufacturing the absorbent body 4 will be described. As shown in FIG. 10, the absorbent body 4 is produced by manufacturing a continuum 10A of lower-layer absorbent bodies and a continuum 11A of upper-layer absorbent bodies, which are continuous in the longitudinal direction, using a predetermined fiber stacking device. It is manufactured by laminating and integrally cutting the continuous body 10A of the lower layer absorbent body and the continuous body 11A of the upper layer absorbent body into a predetermined length. The fiber stacking device for manufacturing the continuous body 10A of the lower-layer absorbent bodies has an absorbent-body-forming concave portion formed continuously in the rotational direction on the outer peripheral surface so that the lower-layer absorbent bodies 10 are continuous in the longitudinal direction. Equipped with a rotating drum for Similarly, in the fiber stacking device for manufacturing the continuous body 11A of the upper layer absorbent body, an absorbent body forming recess having a shape in which the upper layer absorbent body 11 is continuous in the longitudinal direction is formed on the outer peripheral surface so as to be continuous in the rotational direction. Equipped with a rotating drum for stacking. Further, in a state in which the continuous body 10A of the lower absorbent body and the continuous body 11A of the upper absorbent body are laminated, the continuous body 10A of the lower absorbent body and the continuous body 11A of the upper absorbent body are integrally surrounded by the continuous body of the core wrap sheet, and then the continuous body 10A of the lower absorbent body and the upper layer. It is preferable to integrally cut the continuous body 11A of the absorbent body and the continuous body of the core wrap sheet. As shown in FIG. 1, the spillage of the superabsorbent polymer from this cut portion will be removed in a subsequent process by the leakproof sheet 2 extending outward from the absorbent body 4 at the upper and lower edges of the absorbent body 4 . , the outer edge portions of the surface sheet 3 and the exterior sheet 5 are joined together at the joining portion F to prevent this. As described above, in the present pad 1, the upper absorbent core 11 is arranged over the entire length of the lower absorbent core 10. Therefore, in manufacturing the absorbent core 4, the upper absorbent core 11 is formed on the outer peripheral surface of the rotating drum for stacking fibers. The recessed portions for forming the absorbent body can be provided continuously in the circumferential direction, and the production of the absorbent body is facilitated compared to the case where the lower layer absorbent body and the upper layer absorbent body are separately laminated at predetermined intervals as in the conventional art. In addition to improving efficiency, the pulp and polymer that have accumulated in the spaced areas are not wasted, improving yield and eliminating uneven suction. There is an advantage that it becomes almost uniform over the entire length of the absorbent body, and the same body fluid absorbing effect can be obtained up to the ends of the absorbent body.

In the present pad 1, the upper layer absorbent bodies 11 extend along the longitudinal direction and are intermittently arranged in a plurality of strips with spaces in the width direction. Body fluids can easily flow into the lower absorbent body through the gaps 13 formed in the upper layer. That is, when bodily fluids permeate the skin side of the upper absorbent body 11 arranged on the skin-contacting side of the absorbent body 4, the upper absorbent body 11 contains a high water-absorbent polymer with a slow absorption speed, and absorbs Since the content ratio of high-speed pulp fibers is low, a small amount of body fluid is absorbed by the upper layer absorbent body 11, and most of it overflows on the skin side surface of the upper layer absorbent body 11 and migrates to the lower layer absorbent body 10 through the gap 13. . In the lower layer absorbent body 10, the content ratio of the super absorbent polymer is lower than the content ratio of the super absorbent polymer in the upper layer absorbent body 11, and the content ratio of the pulp fibers is higher. As a result, the body fluid is easily absorbed into the lower absorbent body 10 and the absorbed body fluid is easily diffused inside the lower absorbent body 10 . Therefore, the body fluid absorption speed can be increased. In particular, since the gaps 13 are provided continuously over the entire length of the lower absorbent body 10, even if the excretion position deviates in the front-rear direction due to the body shape and posture of the wearer, the mounting position of the pad 1, etc. , the body fluid can be quickly transferred to the lower absorbent body 10 through the gap 13, and the absorption speed can be increased more reliably. The body fluid absorbed by the lower layer absorbent body 10 spreads to the adjacent upper layer absorbent body 11 and is absorbed and retained by the superabsorbent polymer contained in the upper layer absorbent body 11 .

In addition, by making the content ratio of the super absorbent polymer in the upper layer absorbent body 11 higher than the content ratio of the super absorbent polymer in the lower layer absorbent body 10, the water retention capacity of the skin contact side of the lower layer absorbent body 10 is increased. Therefore, it is possible to prevent the body fluid absorbed by the lower absorbent body 10 from returning to the skin side after absorbing the fluid. That is, when the body fluid absorbed by the lower layer absorbent body 10 permeates the skin side and passes through the upper layer absorbent body 11, it is absorbed and retained by the superabsorbent polymer contained in the upper layer absorbent body 11. Body fluid does not overflow to the skin side of 11, and reversal can be prevented. Body fluids that have permeated the skin side of the lower absorbent body 10 in the portion corresponding to the gap 13 are not interposed by the upper absorbent body 11 on the skin contacting surface side, but the upper absorbent body 11 that is adjacent to the gap 13 is absorbed. Since the body fluid is absorbed as if it is drawn into the body, the body fluid does not overflow to the skin side of the upper absorbent core 11 through the gap 13 .

Furthermore, since the content ratio of the superabsorbent polymer is high and the content ratio of pulp fibers is low in the upper layer absorbent body 11, the thickness of the absorbent body 4 is reduced, and the wearing comfort can be improved.

REFERENCE SIGNS LIST 1 Pad 2 Leak-proof sheet 3 Top sheet 4 Absorbent body 5 Exterior sheet 6 Side non-woven fabric 7 Thread-like elastic elastic member 8 Core wrap sheet 10 Lower absorbent body 11 ... upper layer absorbent body, 12 ... notch around the leg, 13 ... gap

Claims (4)

An absorbent article comprising an absorbent body comprising a lower absorbent body containing pulp fibers and a superabsorbent polymer, and an upper absorbent body disposed on the skin side of the lower absorbent body and containing pulp fibers and a superabsorbent polymer. hand,
The upper-layer absorbent body extends along the longitudinal direction and is intermittently arranged over a plurality of strips at intervals in the width direction, and the content ratio of the superabsorbent polymer in the upper-layer absorbent body is the lower-layer absorbent body. is higher than the content ratio of the superabsorbent polymer in
In the lower absorbent body, leg-surrounding notches are formed by notching both sides of the lower-layer absorbent body corresponding to the wearer's crotch,
The upper absorbent body is arranged between the leg-surrounding cutouts of the lower absorbent body, and is positioned in front of the leg-surrounding cutouts on both sides of the lower absorbent body including the leg-surrounding cutouts. and a back side of the absorbent article. The content ratio (X) of the superabsorbent polymer in the upper layer absorbent body is 50 to 90% by weight, the content ratio (Y) of the superabsorbent polymer in the lower layer absorbent body is 5 to 50% by weight, and 2. The absorbent article according to claim 1, wherein the difference (XY) between the content ratio of the superabsorbent polymer in the upper layer absorbent body and the content ratio of the superabsorbent polymer in the lower layer absorbent body is 10 to 85. 2. The upper absorbent body is arranged over the entire length of the lower absorbent body, and a gap formed between adjacent upper absorbent bodies is continuously provided over the entire length of the lower absorbent body. , 2. The absorbent article according to any one of the above. The upper absorbent core arranged between the leg-surrounding notches is arranged along the longitudinal direction in the center of the width direction of the lower absorbent core, and one or a plurality of strips are arranged on both sides of the lower absorbent core. 4. The absorbent article according to any one of 1 to 3.

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