JP6254030B2 - Absorbent articles - Google Patents

Description

  The present invention mainly relates to absorbent articles used for incontinence pads, sanitary napkins, cage sheets, medical pads, toiletries, disposable diapers, and the like, and grooves are formed along the longitudinal direction on the surface side. The present invention relates to an absorbent article.

  Conventionally, as the absorbent article, an absorbent body is interposed between a liquid-impermeable back sheet such as a polyethylene sheet or a polyethylene sheet-laminated nonwoven fabric and a liquid-permeable surface sheet such as a nonwoven fabric or a liquid-permeable plastic sheet. It has been known.

  Numerous improvements have been made to this kind of absorbent article, and it is one of the means for temporary storage and urine diffusion for receiving urine that is drunk at a time, such as a light incontinence pad, in a small area and quickly diffusing it. Various types have been proposed in which concave grooves are formed along the longitudinal direction on the surface side.

  For example, in Patent Document 1 below, in order to suppress bulging caused by swelling of the superabsorbent resin in the absorbent article, a dense layer in which the superabsorbent resin is dense and the dense layer in the vertical direction An absorbent article provided with an absorbent body material having interspersed portions provided with adjacent space layers is disclosed.

  Moreover, in the following patent document 2, a recessed part is formed in the bodily fluid-absorbing core used in the bodily fluid-absorbing article, and the surface layer part that defines the peripheral wall of the recessed part is mainly made of water-absorbing fibers. An article formed by water-absorbing fibers and high water-absorbing polymer particles in which the inner part located inside the surface layer part is in a mixed state is disclosed.

  Furthermore, in the following Patent Document 3, in the disposable diaper provided with a feces pocket for storing and holding excrement in the absorbent body, a superabsorbent polymer is mixed inside the absorbent body, and in portions other than the fecal pocket, An absorbent article having a structure in which a superabsorbent polymer is unevenly distributed on the surface layer side and the stool pocket is unevenly distributed on the peripheral wall portion and the bottom surface portion is disclosed.

JP 2008-237382 A Japanese Patent Application Laid-Open No. 2012-139381 JP 2007-117727 A

  However, in the absorbent article described in Patent Document 1, since the absorbent body around the groove is composed only of pulp, the function of absorbing and holding body fluid diffused around the groove is small, and the amount of return is increased. There was a possibility that the amount of absorbed urine could not be compensated.

  Further, since the absorbent body does not exist by forming a concave groove in the absorbent body, a configuration that compensates for the amount of absorption reduced by that amount is required, as in the absorbent articles described in Patent Documents 2 and 3 above. However, if the structure is not provided to compensate for the reduced amount of absorption, the absorption of the absorber can be achieved by forming the concave groove compared to the case where the concave groove is not provided. There was a risk that the capacity would decrease.

  Furthermore, in the above-mentioned Patent Document 2, since the surface layer portion that defines the peripheral wall of the concave portion is mainly formed of water-absorbing fibers, there is a possibility that the retained body fluid is poorly retained and the amount of reversion is increased. On the other hand, in the above-mentioned Patent Document 3, since the superabsorbent polymer is unevenly distributed on the surface layer side of the absorber, gel block is likely to occur at the time of water absorption, and body fluid may not be easily absorbed inside the absorber. there were. Thus, the absorption capacity of the absorbent body may be reduced depending on the arrangement of the superabsorbent resin with respect to the absorbent body.

  When the concave groove is provided, there is a possibility that the concave groove may be crushed by applying pressure from the inner part of the base of the leg during mounting, and in that case, the effect is remarkably reduced. Therefore, in order to prevent deformation of the concave groove at the time of mounting, a core embossing that squeezes the absorbent body is provided in the concave groove along the concave groove, or a fit embossing that is compressed from the surface side of the liquid-permeable surface sheet is provided. May be provided. At that time, if both side walls and the bottom surface of the groove are pressed and pressed, the problem that the highly water-absorbent resin does not easily expand during water absorption occurs. Since it is squeezed, it is difficult to expand at the time of water absorption, and as a result, the central portion is high and the both side portions are low as a whole. For this reason, unevenness in body pressure load due to the difference in expansion height has occurred, and a sense of pressure at the time of water absorption expansion and reversal due to concentration of body pressure load have occurred.

  Then, the 1st subject of this invention is providing the absorbent article which prevented the fall of the absorption capacity by forming a ditch | groove. A second problem is to provide an absorbent article in which the expansion of the polymer in the groove at the time of water absorption is made uniform and the uneven body pressure applied to the polymer is corrected.

In order to solve the first problem, as the present invention according to claim 1, an absorbent body in which a superabsorbent resin is dispersed and mixed is interposed between the liquid-permeable top sheet and the back sheet, and the skin In the absorbent article in which a concave groove is formed along the longitudinal direction on the contact surface side,
An absorbent article is provided in which a basis weight of the superabsorbent resin in a region overlapping with the concave groove is set higher than a basis weight of the superabsorbent resin in another region.

  In the invention according to claim 1, in the absorbent body in which the superabsorbent resin is dispersed and mixed, the basis weight of the superabsorbent resin in the region overlapping the concave groove is determined from the basis weight of the superabsorbent resin in other regions. Since it is set high, the absorption capacity of the recessed groove portion that has been reduced by forming the recessed groove can be compensated by the highly water-absorbing resin arranged with a high basis weight in the region overlapping the recessed groove, and the absorber It is possible to prevent the absorption capacity of the liquid from decreasing.

  In order to solve the second problem, as a second aspect of the present invention, the basis weight of the superabsorbent resin in the region overlapping with the concave groove is sparse at the center in the width direction and dense at both sides in the width direction. An absorbent article according to claim 1 is provided.

  In the invention according to the second aspect, the basis weight of the highly water-absorbing resin in the region overlapping with the concave groove is provided in a sparse relationship in the center portion in the width direction and in a dense relationship in both side portions in the width direction. The superabsorbent resin sparsely arranged on the sparse part expands in a chevron shape, and the lower part of the ridge at the central part in the width direction deformed into the chevron shape is filled so that each side part in the width direction is densely arranged. The superabsorbent resin provided will expand. For this reason, the height of the concave groove at the time of water absorption becomes substantially uniform, and the body pressure applied to the highly water-absorbent resin is equalized and dispersed, so that the uncomfortable feeling at the time of wearing is reduced and reversal is suppressed. .

  Further, the groove is provided in the groove along the groove, as in the case where the core embossing obtained by pressing the absorbent body is provided, or in the case where the fitting embossing compressed from the surface side of the liquid-permeable surface sheet is provided. If both side walls and bottom of the product are pressed and hardened, there is a problem that the highly water-absorbent resin is less likely to expand during water absorption. Because of this, the force that rises due to water absorption and swelling at the side wall portions that have been pressed and compacted increases, and the height of the expanded concave groove at the time of water absorption becomes substantially uniform.

  The present invention according to claim 3 is the absorbent article according to any one of claims 1 and 2, wherein a superabsorbent resin is disposed along the concave groove on both sides in the width direction of the bottom surface of the concave groove. Provided.

  In the third aspect of the invention, by disposing the highly water-absorbing resin on both sides in the width direction of the bottom surface of the concave groove, the superabsorbent resin dispersed and mixed in the region overlapping the concave groove, and the concave groove The total amount of the superabsorbent resin, which is the sum of the superabsorbent resins arranged on the bottom surface, is provided so as to be sparse at the center in the width direction and dense at both sides in the width direction. For this reason, the height of the concave groove at the time of water absorption becomes substantially uniform, and the body pressure applied to the highly water-absorbent resin is equalized and dispersed, so that the uncomfortable feeling at the time of wearing is reduced and reversal is suppressed. .

  As the present invention according to claim 4, the superabsorbent resin disposed on the bottom surface of the concave groove has a larger absorption capacity and an absorption rate than the superabsorbent resin dispersed and mixed in the absorber. The absorbent article according to claim 3, which uses a product having a low speed.

  In the invention of claim 4, as the superabsorbent resin disposed on the bottom surface of the concave groove, the absorption capacity (the mass of the superabsorbent resin before water absorption is greater than the superabsorbent resin dispersed and mixed in the absorber. The ratio of the amount of water absorption with respect to) is large and the absorption rate is slow, so that the body fluid temporarily stored in the groove is absorbed faster by the highly water-absorbent resin disposed on the bottom surface of the groove, After diffusing into the absorbent body and being absorbed in advance by the superabsorbent resin dispersed and mixed in the absorbent body, the body fluid remaining in the concave groove is transferred to the superabsorbent resin disposed on the bottom surface of the concave groove. Be absorbed. Therefore, the body fluid can be diffused and absorbed over a wide range of the absorber, and the absorption capacity of the absorber can be utilized to the maximum extent.

  As described above in detail, according to the present invention, it is possible to prevent the absorption capacity from being lowered due to the formation of the concave groove. Further, the expansion of the polymer in the concave groove during water absorption can be made uniform, and the uneven body pressure applied to the polymer can be corrected.

It is a partially broken developed view of the incontinence pad 1 according to the present invention. It is the II-II arrow directional view of FIG. It is the III-III arrow directional view of FIG. FIG. 4 is a cross-sectional view of the absorber 4. It is an expanded sectional view of the absorber 4 at the time of water absorption. (A) is an enlarged cross-sectional view of the absorbent body 4 before water absorption and (B) is after water absorption. (A) is an enlarged cross-sectional view of the absorbent body 4 before water absorption, (B) is a water absorption process, and (C) is after water absorption. (A) is an enlarged cross-sectional view of the absorbent body 4 before water absorption and (B) is after water absorption.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

[Basic configuration of incontinence pad 1]
As shown in FIGS. 1 to 3, the incontinence pad 1 according to the present invention includes a liquid-impermeable back sheet 2 made of a polyethylene sheet and the like, a liquid-permeable surface sheet 3 that quickly transmits urine, and the like. Absorbent body 4 made of cotton-like pulp or synthetic pulp interposed between both sheets 2 and 3, and crepe paper or non-woven fabric surrounding the absorbent body in order to maintain the shape and improve the diffusibility of the absorbent body 4 And the like, a hydrophilic second sheet 6 disposed between the liquid-permeable surface sheet 3 and the absorber 4 as necessary, and a substantially side edge portion of the absorber 4 standing upright. From the side nonwoven fabrics 7 and 7 that form a pair of left and right three-dimensional gathers BS and BS provided as base ends and projecting toward the skin side in a predetermined section in the longitudinal direction so as to include at least the body fluid discharge site H Configured and said suction In the periphery of the body 4, the outer edge portion of the liquid-impervious back sheet 2 and the liquid-permeable surface sheet 3 is joined at the edge portion in the longitudinal direction by an adhesive such as hot melt or an adhesive means such as heat seal. In addition, the liquid-impervious back sheet 2 and the side nonwoven fabric 7 that extend laterally from the absorbent body 4 at the both side edges are joined by an adhesive such as hot melt or an adhesive means such as heat seal. ing.

Hereinafter, the structure of the incontinence pad 1 will be described in detail.
The liquid-impervious back sheet 2 is made of a sheet material having at least water-impervious properties such as polyethylene and polypropylene, but in addition to this, a non-woven sheet after securing a substantially liquid-impervious property through a waterproof film. (In this case, a liquid-impervious back sheet is composed of the waterproof film and the nonwoven fabric). In recent years, those having moisture permeability tend to be suitably used from the viewpoint of preventing stuffiness. The water- and moisture-permeable sheet material is a microporous material obtained by melting and kneading an inorganic filler in an olefin-based resin such as polyethylene or polypropylene to form a sheet, and then stretching in a uniaxial or biaxial direction. A sheet is preferably used.

  Next, as the liquid-permeable surface sheet 3, a porous or non-porous nonwoven fabric or a porous plastic sheet is preferably used. Examples of the material fibers constituting the nonwoven fabric include synthetic fibers such as polyethylene or polypropylene, synthetic fibers such as polyester and polyamide, 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 lace method, a spun bond method, a thermal bond method, a melt blown method, or a needle punch method can be used. Among these processing methods, the spunlace method is excellent in terms of flexibility and drapeability, and the thermal bond method is excellent in terms of being bulky and soft.

  The absorbent body 4 is composed of, for example, absorbent fibers such as fluffy pulp and the superabsorbent polymer 8, and in the illustrated example, the planar shape is an oblong shape that is long in the longitudinal direction of the pad. The superabsorbent polymer 8 is, for example, granular powder, and is dispersed and mixed in the pulp constituting the absorber 4.

Examples of the pulp include chemical fibers obtained from wood, cellulose fibers such as dissolving pulp, and artificial cellulose fibers such as rayon and acetate. It is preferably used in terms of price. In this incontinence pad 1, since the absorbent body 4 is surrounded by the encapsulating sheet 5, the encapsulating sheet 5 is interposed between the liquid-permeable surface sheet 3 and the absorbent body 4 as a result. The excellent encapsulating sheet 5 quickly diffuses body fluids and prevents the urine and the like from returning. Basis weight of the ^{pulp, 100g / m 2 ~600g / m} 2, and it is preferably a ^{200g / m 2 ~500g / m 2} .

  Examples of the superabsorbent polymer 8 include a cross-linked polyacrylate, a self-crosslinked polyacrylate, a saponified acrylate-vinyl acetate copolymer cross-linked product, and a cross-linked isobutylene / maleic anhydride copolymer. , A crosslinked polysulfonate, and a partially crosslinked water-swellable polymer such as polyethylene oxide and polyacrylamide. Among these, those based on acrylic acid or acrylate that are excellent in water absorption and water absorption speed are preferred. In the production process, the superabsorbent polymer having the water-absorbing performance can be adjusted in absorption capacity (water-absorbing power) and absorption rate by adjusting the crosslinking density and the crosslinking density gradient. This superabsorbent polymer 8 will be further described in detail later.

  The absorbent body 4 may be mixed with synthetic fibers. As the synthetic fiber, 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. It may be a mixture. In addition, a composite fiber such as a core-sheath fiber, a side-by-side fiber, or a split fiber having a fiber having a high melting point as a core and a fiber having a low melting point as a sheath can also be used. In the case of a hydrophobic fiber, it is desirable to use a synthetic fiber that has been surface-treated with a hydrophilizing agent so as to have an affinity for body fluids.

  The encapsulating sheet 5 can be a paper material such as tissue or a liquid-permeable sheet such as a nonwoven fabric. In particular, it is preferable to use a non-woven fabric that does not easily cause destruction (breaking) of the material when the superabsorbent polymer in the groove 22 expands as will be described in detail later. As such a nonwoven fabric, a nonwoven fabric processed by a spunbond method and an SMS method excellent in balance between thinness and strength, and an elastic fiber made of a thermoplastic elastomer resin are directly connected to a spinning process such as a spunbond method or a melt blow method. Nonwoven fabrics mainly made of stretchable materials such as nonwoven fabrics, latex, urethane and olefinic fibers processed by the method of forming a web are suitable. In the encapsulating sheet 5, the hydrophilicity of the sheet is not particularly limited as long as at least the skin contact surface side (surface side) of the absorbent body 4 is not water-repellent.

  The second sheet 6 only needs to be hydrophilic to body fluids. Specifically, by using recycled fibers such as rayon and cupra, natural fibers such as cotton, the material itself has hydrophilicity, or synthesis of olefins such as polyethylene or polypropylene, polyesters, polyamides, etc. The fiber which surface-treated with the hydrophilizing agent and provided the hydrophilic property can be used. Further, the second sheet 6 may have a porous film layer on the back surface side (absorber 4 side) in order to give a firmness, and a material containing pulp may be used.

  Side nonwoven fabrics 7 and 7 are provided on both sides of the surface of the incontinence pad 1 along the longitudinal direction and over the entire length of the incontinence pad 1, and the outer portions of the side nonwoven fabrics 7 and 7 extend laterally. The liquid-impermeable back sheet 2 is laterally extended, and the side nonwoven fabric 7 portion and the liquid-impermeable back sheet 2 portion that are extended to the side are formed by a hot melt adhesive or the like. Joined to form side flaps.

  As the side nonwoven fabric 7, a water-repellent treated nonwoven fabric or a hydrophilic treated nonwoven fabric can be used from the viewpoint of an important function. For example, if importance is placed on functions such as preventing the penetration of urine, etc. or enhancing the feeling of touch, such as SSMS, SMS, and SMMS coated with a silicon-based, paraffin-based, alkylchromic chloride-based water repellent, etc. It is desirable to use a water-repellent non-woven fabric, and if importance is attached to the absorbability of body fluids, a method of polymerizing a compound having a hydrophilic group, such as an oxidation product of polyethylene glycol, in the synthetic fiber production process, Treating with metal salt such as stannic, partially dissolving the surface to make it porous and making the synthetic fiber swell or porous by applying a metal hydroxide, etc., applying capillary action to impart hydrophilicity It is desirable to use a hydrophilic treated nonwoven fabric. As this side nonwoven fabric 7, what was formed by a proper processing method using natural fiber, synthetic fiber, regenerated fiber, etc. as a raw material can be used.

  The side nonwoven fabrics 7 and 7 are appropriately folded, and a pair of left and right inner solid gathers 10 and 10 that stand on the skin side with the position near the side edge of the absorbent body 4 as a standing base end, and the inner side relatively A pair of left and right outer three-dimensional gathers 11 standing on the skin side formed by the liquid-impervious back sheet 2 and the side nonwoven fabric 7 that are located outside the three-dimensional gather 10 and extend laterally from the absorbent body 4, 11 is a three-dimensional gather BS having a double gather structure. Note that the three-dimensional gather BS may have a single gather structure including only the inner three-dimensional gather 10 or the outer three-dimensional gather 11, or a three-dimensional gather standing up on the skin side simply by disposing the side nonwoven fabric 7. It does not have to be formed into a shape.

  The structure of the inner three-dimensional gather 10 and the outer three-dimensional gather 11 will be described in more detail. As shown in FIG. 2, the side nonwoven fabric 7 is folded back on both sides in the width direction toward the back side of the pad. In the illustrated example, one or a plurality of double sheet portions 7a and 7b are formed on the outer side, and both ends or appropriate positions in the longitudinal direction are fixed inside the double sheet portion 7a on the inner side in the width direction. One or a plurality of thread elastic elastic members 12 are arranged in the double sheet portion 7b on the outer side in the width direction, and two appropriate positions in the longitudinal direction are fixed. Of the liquid-permeable surface sheet 3, in which the base end portion of the double sheet portion 7 a on the inner side in the width direction is disposed on the side portion of the absorbent body 4. While being bonded by a hot-melt adhesive or the like, the base end portion of the double sheet portion 7b on the outer side in the width direction is hot on the side end portion of the liquid-impermeable back sheet 2 that extends to the side of the absorbent body 4. By being bonded by a melt adhesive or the like, the inner solid gathers 10 are formed on the skin side by the double sheet portion 7a on the inner side in the width direction, and the skin side is formed by the double sheet portion 7b on the outer side in the width direction. An outer three-dimensional gather 11 that stands up is formed. As shown in FIG. 3, the side nonwoven fabric 7 is not provided with the elastic elastic members 12 and 13 at both ends in the longitudinal direction of the pad, and the double sheet portion 7a on the inner side in the width direction is hot. It is joined to the absorber 4 side by a melt adhesive or the like.

[About the groove 22]
In the incontinence pad 1, a body fluid inflow groove 22 is formed along the longitudinal direction on the surface side. The concave groove 22 receives body fluid discharged on the surface of the liquid-permeable surface sheet 3, temporarily stores the body fluid, induces diffusion of the body fluid in the front-rear direction, and absorbs the body fluid into the absorber 4. This is to increase the speed and prevent side leakage.

  The concave groove 22 is formed in advance in the absorbent body 4 along the longitudinal direction of the skin contact surface side including the body fluid discharge site, without forming the concave groove-shaped or slit-shaped absorbent concave portion 20 without squeezing. The absorbent body 4 is surrounded by the encapsulating sheet 5, and the liquid-permeable surface sheet 3 and the second sheet 6 are laminated, if necessary, on the surface side (skin contact surface side) of the liquid-permeable surface sheet 3. The embossed portion 21 is formed by forming an embossed portion 21 along the absorber recessed portion 20 inside the absorber recessed portion 20 by embossing.

  Absorber recesses 20 are formed in the absorber 4 in advance without being compressed before the embossed portions 21 are formed. The absorbent body recess 20 is recessed from the periphery to the non-skin contact surface side (impermeable liquid back sheet 2 side) on the skin contact surface side (liquid permeable top sheet 3 side) of the absorber 4. Further, it is a non-penetrating concave groove portion having a bottom surface. For example, as shown in FIG. 4, the absorbent body recess 20 is formed by (A) stacking fiber, or (B) the lower layer absorbent body 4 a formed with the thickness of the bottom of the absorber recess 20, and A portion corresponding to the absorber recess 20 is formed by a laminated structure with the upper absorber 4b opened.

  As shown in FIG. 1, the absorbent body recess 20 is formed in the pad width direction center portion corresponding to the body fluid discharge site H and only one strip in the longitudinal middle portion with respect to the absorbent body 4. However, it is also possible to form a plurality of strips separated in the pad width direction, or to form discontinuous lines separated in the pad longitudinal direction (not shown). In addition, when providing two or more absorber recessed parts 20, it is preferable to provide the said embossed part 21 with respect to each absorber recessed part 20. As shown in FIG.

  As for the planar dimensions of the absorber recess 20, the length in the pad longitudinal direction is preferably 100 to 180 mm, and the groove width (bottom groove width) is 5 to 30 mm. When the absorber recess is formed in a groove shape, the depth of the absorber recess 20 is preferably 50% or more of the thickness of the absorber 4, specifically about 5 to 8 mm.

The absorbent 4 portion interposed in the bottom of the absorbent recess 20 (the liquid-impermeable back sheet 2 side portion, the non-skin side portion) has a pulp basis weight of 70 g / m ^{2 to} 210 g / m ² , preferably preferably set to ^{90g / m 2 ~190g / m 2} . Also in this absorber portion, the water-absorbing polymer 8 is dispersed and mixed with a predetermined basis weight.

The planar dimension when the embossed part 21 is provided may be larger or smaller than the dimension of the absorber recess 20. On the bottom surface of the embossed portion 21, a high-pressure squeezed portion squeezed deeper than the bottom surface of the peripheral concave groove 22 may be formed in an appropriate pattern.
[About super absorbent polymer]
As shown in FIG. 2, the superabsorbent polymer 8 dispersed and mixed in the absorbent body 4 is set such that the basis weight of the region B overlapping the absorbent body recess 20 is higher than the basis weight of the other region A. Specifically, the basis weight of the region B is set to be 50 to 150 g / m ² , preferably about 80 to 130 g / m ² higher than the basis weight of the region A. The basis weight of the superabsorbent polymer 8 in the region A is preferably 100 to 500 g / m ² , and the basis weight of the superabsorbent polymer 8 in the region B is preferably 150 to 650 g / m ² .

  The region B that overlaps with the absorber recess 20 is a region that overlaps with the absorber recess 20 in the thickness direction of the absorber 4, and the space within the absorber recess 20 and the bottom surface of the absorber recess 20. It is the area | region containing the absorber part formed thinner than the other part on the lower side (non-skin side). The other region A is a region other than the region B, and is a region where the absorber other than the absorber recess 20 is formed thick.

  By setting the basis weight of the superabsorbent polymer 8 in the region B overlapping with the absorber concave portion 20 to be higher than the basis weight of the superabsorbent polymer 8 in other regions A, it was reduced by forming the absorber concave portion 20. The absorption capacity of the absorbent body 4 can be supplemented by the superabsorbent polymer 8, so that the absorption capacity of the absorbent body 4 can be prevented from decreasing.

  Further, since the superabsorbent polymer 8 is also dispersed and mixed in the other region A, the body fluid diffused in this region is absorbed and held in the superabsorbent polymer 8 and the absorbent body 4 is compressed by the body pressure. However, reversal is less likely to occur.

  On the other hand, as shown in FIG. 2, when the superabsorbent polymer 8 disposed in the region B overlapping with the absorber recess 20 is uniformly distributed over the width direction of the absorber recess 20, at the time of water absorption, In the cross-sectional view of the absorbent body 4 shown in FIG. 5, the absorbent body recess 20 bulges into a mountain shape in which the central part in the width direction is high and both sides are low. In particular, in the incontinence pad 1, the absorber recess 20 is formed without squeezing. Therefore, when the bottom of the absorber recess 20 rises, the resistance at the side wall of the absorber recess 20 becomes very large. There is a tendency that both sides in the width direction do not rise easily.

As a first means for solving such a problem, in the incontinence pad 1, as shown in FIG. 6A, in the region B overlapping with the absorber recess 20, the absorber 4 is dispersed and mixed. and the basis weight of superabsorbent polymer 8, sparse at the widthwise central portion B _1, can be provided in close relationship with both widthwise side portion B _2. That is, the basis weight of superabsorbent polymer 8 arranged in the widthwise central portion B ₁ is, is set smaller than the basis weight of the superabsorbent polymer 8 arranged on both sides in the width direction portion B _2.

Specifically, the basis weight of superabsorbent polymer 8 of the widthwise central portion _{B 1} represents preferably ^{150~400g / m 2, 200~350g / m} 2 is more preferable. Also, the basis weight of superabsorbent polymer 8 of the widthwise side portion _{B 2} is preferably ^{400~650g / m 2, 450~600g / m} 2 is more preferable. Incidentally, the basis weight of the widthwise central portion B ₁ represents, is set higher than the basis weight of the other area A.

Thus, as shown in FIG. 6 (B), at the time of water absorption, together with the superabsorbent polymer 8 arranged sparsely in the widthwise central portion B ₁ is expanded in Yamagata, the widthwise central portion B ₁ is Yamagata Since the highly water-absorbing polymer 8 arranged densely on each of the widthwise side portions B ₂ and B ₂ expands more strongly so as to fill the low part of the mountain ridge that has been deformed, the absorber recess 20 at the time of water absorption The inflated height is substantially uniform. Therefore, since the body pressure applied to the expanded superabsorbent polymer 8 is equalized and dispersed, the uncomfortable feeling and the feeling of pressure at the time of wearing are reduced. Furthermore, since the body pressure applied to the highly water-absorbing polymer 8 that has absorbed water is dispersed, it is possible to suppress reversion.

Moreover, when the said absorber recessed part 20 is formed by squeezing from the skin side surface, or as mentioned above, the absorber recessed part 20 inside the absorber recessed part 20 by embossing from the surface side of the said liquid-permeable surface sheet 3 is carried out. When the embossed portion 21 is formed along the both side walls and the bottom surface of the absorbent body recess 20, there is a problem that the highly water-absorbing polymer 8 is difficult to expand at the time of water absorption. However, this in the incontinence pad 1, since that is closely arranged in the width direction both sides B ₂ as described above, the force raised by hygroscopic expansion in both side walls that are compacted is increased, the absorption of water The height of the expanded concave groove can be made substantially uniform.

  In the incontinence pad 1, the encapsulating sheet 5 and the absorbent body 4 are moved to the extent that the superabsorbent polymer 8 is not released even if the superabsorbent polymer 8 absorbs and expands along the absorbent body recess 20 in the absorbent body recess 20. A fixing part (not shown) joined by joining means such as heat sealing or hot melt adhesive can be provided. The fixing portion is provided continuously or intermittently along the absorber recess 20. By providing the fixing portion, the bulge toward the skin side when the superabsorbent polymer 8 absorbs and expands is suppressed, so that the superabsorbent polymer 8 that absorbs and expands by the first urination can block the groove 22. Since the structure of the concave groove 22 can be maintained after the first water absorption, the space for movement and expansion of the superabsorbent polymer 8 can be controlled even in the case of multiple urinations.

Next, as a second means for solving the problem that the absorber recess 20 swells in a mountain shape, as shown in FIG. 7A, the basis weight of the superabsorbent polymer 8 in the region B overlapping the recess is shown. In addition, a highly water-absorbing polymer 23 can be separately disposed along the absorber recess 20 on both sides of the bottom surface of the absorber recess 20 in the width direction. The superabsorbent polymer 23 is on the bottom surface of the absorber recess 20 and is fixed to the absorber 4 side with an adhesive or the like between the absorber 4 and the encapsulating sheet 5. As in the above first means, sparse basis weight of the absorbent body recess 20 superabsorbent polymer was formed region 8 in the widthwise central portion B _1, provided in close relationship with both widthwise side portion B ₂ In addition, the highly water-absorbing polymer 23 may be disposed on both sides of the bottom surface of the absorber recess 20.

Thus, the basis weight of the sum of the superabsorbent polymer 8 and 23, as in the first means, sparse at the widthwise central portion B ₁ of the absorbent body recess 20, in close relation with the width direction of both side portions B ₂ become provided, at the time of water absorption, together with the superabsorbent polymer 8 arranged sparsely in the widthwise central portion B ₁ is expanded in Yamagata, lower the foot of the mountain of the widthwise central portion B ₁ is deformed in Yamagata Since the highly water-absorbing polymers 8 and 23 arranged densely in the width direction both side parts B ₂ and B ₂ are expanded so as to fill the part, the height of expansion of the absorber concave portion 20 at the time of water absorption is substantially uniform. Become.

The superabsorbent polymers 23 and 23 disposed on both sides of the bottom surface of the absorber recess 20 may have a basis weight of 60 to 200 g / m ² , preferably 80 to 180 g / m ² . Moreover, when arrange | positioning the said high water absorption polymer 23, it is preferable to arrange | position about 1-2 mm apart from the side surface of the absorber recessed part 20, and it is preferable that the width | variety of the bottom face of the absorber recessed part 20 shall be 10 mm or more. More preferred.

  As the superabsorbent polymer 23, the same superabsorbent polymer 8 dispersed and mixed in the absorber 4 may be used, but it is preferable to use a polymer having different properties as described in detail below.

  When the polymer having different properties is used as the superabsorbent polymer 8, 23, the superabsorbent polymer 23 disposed on both sides of the bottom surface of the absorber recess 20 is compared with the superabsorbent polymer 8 dispersed and mixed in the absorber 4. Thus, it is preferable to use a material having a large absorption capacity and a low absorption rate.

The absorption capacity of the superabsorbent polymers 8 and 23 is determined by enclosing a superabsorbent polymer having a mass Wc = 0.5 g in a tea bag (200 mesh nylon bag) having a known mass Wb and having a 200 ml capacity beaker. Into 100 ml of physiological saline, the tea bag was immersed for 30 minutes and then taken out, suspended for 5 minutes, drained, the total mass Wa after water absorption was measured, and the absorption ratio was calculated from the following equation To do.
Absorption capacity = (Wa−Wb) / Wc
In the incontinence pad 1, the absorption rate of the superabsorbent polymer 23 disposed on the bottom surface of the absorbent recess 20 is 1.1 compared with the absorption factor of the superabsorbent polymer 8 dispersed and mixed in the absorber 4. Those adjusted to be about -2.0 times larger, preferably those adjusted to be about 1.2-1.8 times larger are used. As described above, the absorption ratio of the superabsorbent polymer can be adjusted by adjusting the crosslink density and the crosslink density gradient in the production process of the superabsorbent polymer.

  On the other hand, the absorption speed of the superabsorbent polymers 8 and 23 is determined by placing 50 ml of physiological saline and a stirrer chip in a beaker having a capacity of 100 ml, stirring with a magnetic stirrer at a rotational speed of 600 ± 60 rpm, With the vortex generated, 2.0 g of the superabsorbent polymer is quickly added, and the time from the addition to the convergence of the vortex on the liquid level is measured with a stopwatch, and this time is taken as the absorption rate.

  In this incontinence pad 1, the absorption rate of the superabsorbent polymer 23 disposed on the bottom surface of the absorber recess 20 is 10 seconds to that of the superabsorbent polymer 8 dispersed and mixed in the absorber 4. What was adjusted late about 50 seconds, Preferably what was adjusted late about 10 seconds-20 seconds is used. As described above, the absorption rate of the superabsorbent polymer can be adjusted by adjusting the crosslink density and the crosslink density gradient in the production process of the superabsorbent polymer.

  As described above, by using the superabsorbent polymer 23 having a larger absorption capacity and a slower absorption rate than the superabsorbent polymer 8, the body fluid temporarily stored in the absorber recess 20 becomes the absorber recess. The superabsorbent polymer 23 diffused into the absorber 4 sooner than it is absorbed by the superabsorbent polymer 23 disposed on the bottom surface of 20 and dispersed and mixed in the absorber 4 as shown in FIG. 8, the body fluid remaining in the absorber recess 20 is absorbed by the superabsorbent polymer 23 (FIG. 7C). Therefore, since the bodily fluid temporarily stored in the absorber recess 20 is diffused and absorbed in a wide range of the absorber, the absorption capacity of the absorber 4 can be utilized to the maximum extent.

As a third means for solving the problem that the absorber recess 20 bulges in a mountain shape, as shown in FIG. 8A, the absorber recess 20 overlaps with the absorber recess 20 as compared with the second means. the basis weight of the superabsorbent polymer 8, which is dispersed and mixed in the region B, high in the widthwise central portion B ₁ of the absorbent body recess 20 is set to be lower in the both widthwise side portion B _2. For this reason, compared with the said 2nd means, the rise of the bottom face of the absorber recessed part 20 at the time of water absorption becomes large, and the expansion height of the absorber recessed part 20 at the time of water absorption becomes more uniform easily.

  By the way, it is desirable that the volume of the absorbent recess 20 is substantially equal to the expanded volume of the superabsorbent polymers 8 and 23 upon water absorption. Thereby, when the highly water-absorbing polymers 8 and 23 arranged on the lower side and the bottom surface of the absorber recess 20 are absorbed and expanded, the height of the swell of the bottom surface of the absorber recess 20 and the height of the surrounding absorbers are substantially equal. As a result, the discomfort at the time of wearing can be further alleviated. The rising height of the bottom surface of the absorber recess 20 at the time of water absorption is 5 to 5 in which the height after 15 to 20 seconds elapses after 25 cc ± 5 cc of urine is sprayed on the absorber recess 20. The amount of the superabsorbent polymers 8 and 23 is adjusted to be about 8 mm.

For example, in the incontinence pad 1 employing the first means shown in FIG. 6, the volume of the absorbent body recess 20 and the volume when the superabsorbent polymer 8 expands due to water absorption are substantially equal, and the superabsorbent polymer 8 Exemplifying the condition that the height when water absorbs and expands is equivalent to the height of the surrounding absorber, the absorber recess 20 is formed with dimensions of 145 mm in length, 10 mm in width, and 8 mm in depth, and the material is polyacrylic acid 25 cc when the superabsorbent polymer 8 made of a salt cross-linked product is arranged with a basis weight of 200 g / m ^{2 in} the center part B ₁ in the width direction and with a basis weight of 450 g / m ^{2 in} both side parts B ₂ in the width direction. This can occur when the urine of urine is allowed to flow into the absorber recess 20.

  Of the incontinence pad 1 having the above configuration, the manufacturing process of the absorbent body 4 will be described in detail. The absorbent body is provided with the absorbent body concave portion 20 and the absorbent body 8 is dispersed and mixed in a predetermined area with a predetermined basis weight. 4 is manufactured by stacking fibers, etc., and then, if necessary, the superabsorbent polymer 23 is fixed to both sides in the width direction of the bottom surface of the absorber recess 20, and the absorber 4 is surrounded by the encapsulating sheet 5 as necessary. . The encapsulating sheet 5 may be drawn out into a line before the production of the absorbent body 4 and used as a transport base for the absorbent body 4, or the super absorbent polymer 23 is sprayed on the bottom surface of the absorbent body recess 20 to surround the absorbent body. You may pay out to the line.

  DESCRIPTION OF SYMBOLS 1 ... Incontinence pad, 2 ... Impervious back sheet, 3 ... Impervious surface sheet, 4 ... Absorber, 5 ... Encapsulated sheet, 6 ... Second sheet, 7 ... Side nonwoven fabric, 8 ... Super absorbent polymer, DESCRIPTION OF SYMBOLS 10 ... Inner three-dimensional gather, 11 ... Outer three-dimensional gather, 12.13 ... Thread-like elastic elastic member, 20 ... Absorber recessed part, 21 ... Embossed part, 22 ... Groove, 23 ... Super absorbent polymer

Claims (4)

An absorbent article in which an absorbent body in which a superabsorbent resin is dispersed and mixed is interposed between the liquid-permeable top sheet and the back sheet, and a groove is formed along the longitudinal direction on the skin contact surface side. In
An absorbent article, wherein a basis weight of the superabsorbent resin in a region overlapping with the concave groove is set higher than a basis weight of the superabsorbent resin in another region.   2. The absorbent article according to claim 1, wherein the basis weight of the superabsorbent resin in a region overlapping with the concave groove is provided in a sparse relationship at a central portion in the width direction and a dense relationship at both side portions in the width direction.   The absorbent article according to any one of claims 1 and 2, wherein a highly water-absorbent resin is disposed along the concave groove on both sides in the width direction of the bottom surface of the concave groove.   The high water-absorbent resin disposed on the bottom surface of the concave groove has a higher absorption capacity and a slower absorption rate than the high water-absorbent resin dispersed and mixed in the absorber. 3. The absorbent article according to 3.

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