JP6441629B2 - Absorbent articles - Google Patents

Description

  The present invention relates to an absorbent article mainly used for incontinence pads, disposable diapers, and the like, and more particularly to an absorbent article having a groove formed along the longitudinal direction on the skin side.

  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. Things are known.

  Many improvements have been made to this type of absorbent article, and in particular, as a means of temporary storage and urine diffusion, in order to receive and spread quickly in a small area, such as an incontinence pad, in a small area, Various proposals have been made in which concave grooves are formed along the longitudinal direction on the skin side.

  In the following Patent Document 1, it has a liquid-permeable top sheet, a liquid-impervious back sheet, and a liquid-absorbent core interposed between both sheets, and the core is covered with an absorbent diffusive sheet. The core is formed with at least one groove recessed in the direction from the top sheet to the back sheet on the top sheet side, and the bottom and side walls of the groove are covered with the top sheet. In the diaper, the core includes water-absorbing fibers and superabsorbent polymer particles, and the water-absorbing fibers and superabsorbent polymer particles are interposed between the top sheet and the back sheet at the bottom of the groove. A disposable diaper is disclosed.

  Moreover, in following patent document 2, the absorbent article which has a liquid-permeable surface sheet, the back surface sheet | seat arrange | positioned at the non-skin contact surface side, and the liquid absorptive absorber arrange | positioned between these both sheets. The absorbent body has an upper layer absorbent body on the skin contact surface side and a lower layer absorbent body on the non-skin contact surface side, and the middle and high portions formed by the upper layer absorbent body and the lower layer absorbent body are: (1) a portion forming the recess in the middle and high portions is formed on the skin contact surface side, and a convex portion on a lower surface of the upper absorbent body protruding toward the non-skin contact surface side. A recess on the upper surface of the lower layer absorber that is integral with the lower layer absorber, or (2) the recess is an opening that penetrates the upper layer absorber, and forms a bottom surface of the opening. An absorbent article is disclosed in which the lower layer absorber is located on the lower surface of the upper layer absorber.

JP 2002-165834 A JP 2009-112590 A

  In the absorbent article described in Patent Documents 1 and 2, a concave groove that is recessed along the longitudinal direction on the skin side along with the surface sheet is formed on the non-skin surface side, and even if a large amount of urine is discharged at a time, urine is discharged. At the same time that the groove is temporarily stored, urine is prevented from leaking sideways by diffusing in the longitudinal direction in the groove.

  However, in order to receive the urine discharged at a time in the groove and diffuse it along the longitudinal direction, there is a problem that the cross-sectional area (depth and width) of the groove must be secured to some extent. there were. Since the groove is configured as a space where there is no absorber and is a part with extremely low rigidity, if the cross-sectional area of the groove is increased, it will become rigid when subjected to foot pressure from both sides in the width direction during wearing. Therefore, problems such as the absorption of the absorber and the deformation of the groove have occurred.

  In addition, when it is desired to make the absorber thin for reasons such as storage and ease of carrying, the depth of the groove cannot be secured sufficiently, so the width of the groove should be increased to receive a large amount of urine. There was a problem that the above-mentioned problem became more serious.

  Then, the main subject of this invention is enabling the reduction | decrease of the cross-sectional area of the said ditch | groove in the absorbent article by which the ditch | groove was formed along the longitudinal direction on the skin side.

In order to solve the above problems, as the present invention according to claim 1, in an absorbent article in which an absorber is interposed between a liquid-permeable top sheet and a back sheet,
The absorbent body has a groove-shaped or slit-shaped absorbent body on the surface of the liquid-permeable surface sheet side along the longitudinal direction of the absorbent article and over the longitudinal range including the urine discharge site without being squeezed. With a recess,
Between the liquid-permeable surface sheet and the absorbent body, a fiber assembly sheet made of tow is disposed in a state where the fiber direction is the longitudinal direction of the absorbent article,
In the state where the fiber assembly sheet made of the tow and the liquid-permeable surface sheet are laminated on the upper surface of the absorber, the absorber concave portion is formed on the absorber concave portion with respect to the bottom surface of the absorber concave portion from the surface side of the liquid-permeable surface sheet. by applying embossed along concave groove in the longitudinal direction are formed on the skin side, both side surfaces and the bottom surface of the recessed groove is covered by a fiber aggregate sheet comprising the toe and the liquid-pervious topsheet An absorbent article is provided which is characterized in that

In the first aspect of the present invention, the absorbent body is not squeezed across the longitudinal range of the absorbent article along the longitudinal direction of the absorbent article and including the urine discharge site on the surface of the liquid-permeable topsheet. A concave groove-shaped or slit-shaped absorber concave portion is provided, and the bottom surface of the absorber concave portion is embossed along the absorber concave portion, thereby forming a concave groove along the longitudinal direction on the skin side of the absorbent article. Therefore, the urine discharged at a stroke flows into the concave groove, diffuses back and forth along the concave groove, passes through the peripheral surface of the concave groove, and is absorbed by the absorber. For this reason, since the urine diffused through the concave groove is absorbed by a wide range of the absorber, the urine is quickly absorbed and side leakage can be prevented. In addition, the density of the absorbent body around the concave groove can be prevented from becoming extremely high compared to the case where the concave groove is formed by squeezing integrally with the absorbent body, and urine temporarily stored in the concave groove is absorbed. It becomes easy to move to the body.

  In order to reduce the cross-sectional area of the concave groove, in the present invention, in particular, the fiber assembly sheet made of tow has the fiber direction as the longitudinal direction of the absorbent article between the liquid-permeable surface sheet and the absorbent body. In a state where the fiber aggregate sheet made of the tow and the liquid permeable surface sheet are laminated on the upper surface of the absorbent body, embossing is performed from the surface side of the liquid permeable surface sheet, and the skin side The concave groove is formed along the longitudinal direction. Both side surfaces and bottom surface of the groove are covered with the liquid-permeable surface sheet and the fiber assembly sheet made of the tows.

  As a result of repeated thought and error, the inventor has tried to reduce the cross-sectional area of the groove without reducing the performance, and as a result, if the diffusibility of urine in the longitudinal direction can be further improved in the groove, We focused on the fact that the same performance can be maintained even if the cross-sectional area is reduced.

  In the past, fiber assembly sheets made of tow were often mixed into the absorbent body together with the piled pulp that mainly constitutes the absorbent body. It is mentioned that the diffusibility in the fiber direction is very high. In the present invention, by utilizing the high diffusibility of the fiber assembly made of tow, if the urine flowing into the groove can be quickly diffused in the longitudinal direction before overflowing, the cross-sectional area of the groove is reduced. However, attention has been paid to the fact that the same performance can be maintained, and the present invention has been achieved. The “fiber assembly sheet made of tow” will be described in detail later.

  Therefore, in the absorbent article according to the present invention, since the cross-sectional area of the groove formed along the longitudinal direction on the skin side can be reduced, it is possible to prevent the absorbent body from being bent or deformed. It becomes possible. In addition, it becomes possible to easily meet the demand for reducing the thickness of the absorber in order to improve the storage performance and the ease of carrying.

  As this invention which concerns on Claim 2, while having superabsorbent resin mixed in the inside of the said absorber, superabsorbent resin is spread | dispersed between the fiber assembly sheet | seat which consists of the said absorber and tow | toe. An absorbent article according to claim 1 is provided.

  In the invention according to the second aspect, the superabsorbent resin is mixed inside the absorbent body, and the superabsorbent resin is dispersed between the absorbent body and the fiber assembly sheet made of tow. It is. Even when the urine absorbed by the absorbent body while diffusing along the concave groove cannot be held inside the absorbent body and is about to ooze out to the skin side, it is between the absorbent body and the fiber assembly sheet made of tow. Because it is absorbed and retained by the resin sprayed on the urine, it is possible to reliably prevent urine collected in the absorbent body from returning to the surface side of the liquid-permeable surface sheet, and to maintain a smooth feeling of the surface material after water absorption. become.

  Further, the fiber assembly sheet made of the tow is bulky and can quickly diffuse the body fluid that has absorbed many gaps between the fibers, but after absorbing the liquid, it is crushed and thinned to reduce the liquid permeability. There is a drawback that tends to decrease. Therefore, the fiber assembly made of tow is formed by spraying a superabsorbent resin on the lower surface side of the fiber assembly sheet made of tow and quickly absorbing the body fluid absorbed by the fiber assembly sheet made of tow with the super absorbent polymer. It becomes possible to maintain the liquid permeability of the body sheet.

  As the present invention according to claim 3, there is provided an absorbent article according to any one of claims 1 and 2, wherein embossments in a staggered pattern, a lattice pattern, or an oblique lattice pattern are formed on the skin surface side of the absorber. .

  In the invention of claim 3, by forming staggered, latticed or diagonal latticed embossments on the skin surface side of the absorber, the liquid flow can be slowed when the discharged urine flows laterally. In addition, when combined with the invention according to claim 2 above, a zigzag pattern in which the superabsorbent resin dispersed between the absorbent body and the fiber assembly sheet made of tow is formed on the skin surface side of the absorbent body, It becomes difficult to move in the front-rear and left-right directions due to the embossing in a lattice or diagonal lattice. Therefore, it is possible to prevent the highly water-absorbing resin from gathering at one place and expanding due to water absorption, thereby significantly impairing the wearing feeling.

  As the present invention according to claim 4, there is provided the absorbent article according to any one of claims 1 to 3, wherein the fiber assembly sheet made of the tow is disposed on the entire upper surface side of the absorber.

  In the invention described in claim 4, the fiber assembly sheet made of the tow is disposed not only on the concave groove region but also on the entire upper surface side of the absorbent body. By arranging the fiber assembly sheet made of tow over the entire upper surface of the absorbent body, the compression recovery property at the time of wearing, the liquid return to the surface is less, and even a twist is added to the absorbent body The advantage that cracks and twists are less likely to occur in the absorbent body due to restraint by tow fibers.

As the present invention according to claim 5 , the fiber assembly sheet made of the tow has a surface whose skin side surface includes a plurality of ridges and a plurality of grooves along the fiber direction, and the fiber made of the tow. The absorbent article according to any one of claims 1 to 4, wherein the assembly sheet has an entanglement point formed by entanglement of tow fibers.

In the invention described in claim 5, regarding the physical properties of the fiber assembly sheet made of tow, the skin side surface forms a surface including a large number of ridges and a large number of grooves along the fiber direction. Therefore, the amount of fiber in the buttock is larger than the amount of fiber in the groove, so it has excellent compression resistance and the absorption rate is not easily lowered even when body pressure is applied, so that leakage can be reduced even after long use. become. Moreover, the fiber assembly sheet | seat which consists of the said tow has the entanglement point formed when the fiber of tow | entangles mutually. There are products that fix tow fibers together with a water-soluble adhesive, but in such products, when the liquid is absorbed, the water-soluble adhesive dissolves and the intersection disappears, so Although there is a drawback that the permeability tends to decrease, the fibers are tied together by the entanglement points due to the entanglement of the fibers, so that it can follow the swelling of the superabsorbent resin and suppress the deformation of the fiber assembly sheet. Can do. In addition, the fiber assembly sheet can maintain its shape even when subjected to intense body pressure, and the water-soluble adhesive may coat the superabsorbent resin by dissolution and impair the absorption performance. Since no adhesive is used, the absorption inhibition of the highly water-absorbent resin hardly occurs.

  As described above in detail, according to the present invention, in the absorbent article in which the groove is formed on the skin side along the longitudinal direction, the cross-sectional area of the groove can be reduced.

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 a perspective view of the fiber assembly sheet | seat 15 which consists of tows. It is a top view which shows the embossing pattern example (A)-(C) formed in the upper surface of the absorber 4. FIG. It is a top view at the time of arrange | positioning partially the fiber assembly sheet | seat 15 which consists of a tow in the range containing the concave groove 22. FIG. (A), (B) is an expanded view of the incontinence pad 1 which shows the other Example of the groove 22. (A)-(C) are the expanded views of the incontinence pad 1 which shows the other Example of the groove 22. (A)-(F) are the expanded views of the incontinence pad 1 which shows the other Example of the groove 22. It is sectional drawing of the incontinence pad 1 which shows the other Example of the absorber recessed part 20. FIG.

  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. In order to maintain the shape of the absorbent body 4 and improve the diffusibility, the absorbent body 4 is surrounded by the absorbent body 4 made of cotton-like pulp or synthetic pulp interposed between the two sheets 2 and 3. The wrapping sheet 5 made of crepe paper, nonwoven fabric, or the like, and a substantially side edge portion of the absorbent body 4 as an upright proximal end and projecting toward the skin side in a predetermined section in the longitudinal direction so as to include at least the urine discharge site H A state in which the fiber direction is the longitudinal direction of the incontinence pad 1 between the pair of left and right three-dimensional gathers BS provided on the side, the side nonwoven fabrics 7 and 7 forming the BS, and the liquid-permeable surface sheet 3 and the absorbent body 4 From the tow arranged in The outer periphery of the liquid-impervious back sheet 2 and the liquid-permeable surface sheet 3 is hot at the end edge in the longitudinal direction around the absorbent body 4 mainly composed of the fiber assembly sheet 15. The liquid-impervious back sheet 2 and the side nonwoven fabric 7 which are bonded by an adhesive such as a melt or an adhesive means such as heat seal and extend laterally from the absorbent body 4 at both side edges thereof are hot. They are joined by an adhesive such as a melt or an adhesive means such as heat sealing. In addition, a hydrophilic second sheet can be arrange | positioned between the said liquid-permeable surface sheet 3 and the absorber 4 as needed.

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. Of these processing methods, the spunlace method is excellent in terms of flexibility and drapeability, and the thermal bond method is excellent in terms of bulkiness and high compression recovery.

  The absorbent body 4 is composed of absorbent fibers such as cotton pulp and a highly water-absorbent resin 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 resin 8 is, for example, granular powder, dispersed and mixed in the pulp constituting the absorbent body 4, and mixed with the absorbent fibers almost uniformly without being unevenly distributed in part.

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 diffuses urine quickly and prevents the urine 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 resin 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 of the highly water-absorbent resin having the water-absorbing performance, it is possible to adjust the absorption ratio (water absorption power) and the absorption speed by adjusting the cross-linking density and the cross-linking density gradient.

  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 hydrophobic fibers, it is desirable to use the synthetic fibers surface-treated with a hydrophilizing agent so as to have affinity for urine.

  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 nonwoven fabric that does not easily cause destruction (breaking) of materials. 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.

  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 emphasis is placed on urine absorbability, 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.

In this incontinence pad 1, as shown in FIGS. 1 to 3, a concave groove 22 for inflow of urine is formed along the longitudinal direction on the skin side. The concave groove 22 receives urine discharged on the surface of the liquid-permeable surface sheet 3, temporarily stores urine, induces urine diffusion in the front-rear direction, and absorbs urine into the absorber 4. This is to increase the speed and prevent side leakage.
[About the groove 22]
Hereinafter, the concave groove 22 will be described in detail.

  The concave groove 22 may be formed by integrally squeezing components from the surface side of the liquid-permeable surface sheet 3 to the absorber 4 from the surface side of the liquid-permeable surface sheet 3. The absorbent body recess 20 is formed in a portion where the concave groove 22 is to be formed, and the constituent member that is above the absorbent body 4 from the surface side (skin surface side) of the liquid-permeable surface sheet 3 along the absorber recess 20. What formed by providing the embossed part 21 which squeezes is desirable for the reason that deformation of the concave groove 22 due to leg pressure can be prevented.

  In the incontinence pad 1, the absorbent body 4 is formed on the skin side (liquid permeable surface sheet 3 side) in advance on the portion where the concave groove 22 is to be formed, as shown in FIGS. 1 and 2. In addition, along the longitudinal direction including the urine discharge site H, there is formed a concave groove-shaped or slit-shaped absorber concave portion 20 in the illustrated example without being squeezed. 2 has a non-skin contact surface side (liquid-impervious back sheet 2 side) from the periphery on the skin contact surface side (liquid-permeable surface sheet 3 side) of the absorbent body 4. ) 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 recess 20 is formed only on the absorbent body 4 at the center in the pad width direction corresponding to the urine discharge site H and in the middle in the longitudinal direction. However, the incontinence pad 1 may be formed in a plurality of strips spaced apart in the width direction, or may be formed in various forms such as a discontinuous line shape spaced apart in the pad longitudinal direction (FIGS. 8 to 8). (See FIG. 10). The absorbent recess 20 is formed in a groove shape that is long in the longitudinal direction of the pad at a position including the portion corresponding to the urine discharge portion H in both cases where only one strip is formed and in other forms. Yes. In addition, when providing the some absorber recessed part 20, it is preferable to provide the 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 2 to 30 mm. The depth of the absorber recess 20 is preferably 50% or more of the thickness of the absorber 4, specifically about 2 to 8 mm.

  The absorber 4 is preferably set so that the density of the bottom surface of the absorber recess 20 and the density of the periphery (portion other than the absorber recess 20) are substantially the same. That is, it is preferable that the density of the absorbent body is made substantially the same by forming the absorbent body concave part 20 in a concave groove shape without squeezing.

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 0 g / m ^{2 to} 210 g / m ² , preferably preferably set to ^{70g / m 2 ~190g / m 2} . The superabsorbent resin 8 is also dispersed and mixed in the absorber portion with a predetermined basis weight.

  By providing the concave groove 22, urine discharged at once flows into the concave groove 22 and is temporarily stored, and while diffusing forward and backward along the concave groove 22, It penetrates and is absorbed by the absorber 4. Thus, since urine diffused back and forth through the concave groove 22 is absorbed in a wide range of the absorber 4, urine can be absorbed quickly and side leakage can be prevented.

  The concave groove 22 is embossed from the surface side of the liquid-permeable surface sheet 3 in a state where the liquid-permeable surface sheet 3 and the fiber assembly sheet 15 made of the tow are laminated on the upper surface side of the absorbent body 4. The both side surfaces and the bottom surface of the concave groove 22 are covered with the liquid-permeable surface sheet 3 and the fiber assembly sheet 15 made of tow.

  Hereinafter, the fiber assembly sheet 15 made of the tow will be described in detail.

  Tow refers to a long fiber bundle in which many spun yarns of chemical fibers are collected. In this specification, a tow is a bundle of continuous filaments (fiber assembly), and each filament is aligned in a certain direction. Means what In the present invention, the tow processed into a sheet is used.

  Examples of fibers constituting the fiber assembly (hereinafter simply referred to as tow constituent fibers) include polysaccharides or derivatives thereof (cellulose, cellulose ester, chitin, chitosan, etc.), synthetic polymers (polyethylene, polypropylene, polyamide, polyester, Polylactamides, polyvinyl acetate, etc.), and cellulose esters and cellulose are particularly preferred.

  Since it is necessary for the fiber to have hydrophilicity, it is preferable to use a hydrophilic fiber in nature. However, in the case of a material that does not have hydrophilicity, a fiber imparted with hydrophilicity by applying a hydrophilic treatment. Used as

  As the fiber assembly sheet 15 made of tow, a flat sheet having a smooth surface may be used. Preferably, as shown in FIG. 5, the skin side surface has a large number along the fiber direction. It is desirable to form a surface including a plurality of groove portions 15a, 15a ... and a large number of groove portions 15b, 15b ..., and to have an entanglement point formed by entanglement of tow fibers. The fiber assembly sheet 15 composed of a tow having such physical properties can be formed by spraying a fluid on the sheet-like tow while the conveying direction is the fiber direction. By spraying the fluid, the tow fibers receive the kinetic energy of the ejected fluid, and the fibers are entangled to form an entanglement point. In addition, when a jetting device having a large number of fluid nozzles in the width direction is used, the fibers at the part where the fluid collides are sorted in a direction perpendicular to the transport direction, so that a large number of flanges and a large number of grooves are formed on the surface. The groove surface which has along a direction can be formed. As the fluid, heated air, air such as water vapor, or liquid such as water or warm water can be used. It is desirable to use heated air or water vapor as the fluid in that a subsequent drying step is unnecessary. The fiber assembly sheet 15 made of tow having such physical properties can be obtained as a “web made of tow” disclosed in JP 2012-213480 A.

  The fiber assembly sheet 15 made of the tow is disposed between the liquid-permeable surface sheet 3 and the absorber 4 as shown in FIG. When the absorbent body 4 is surrounded by the encapsulating sheet 5 as in this example, it is disposed between the encapsulating sheet 5 that covers the skin side surface of the absorbent body 4 and the liquid-permeable surface sheet 3. When a hydrophilic second sheet (not shown) is provided between the liquid-permeable surface sheet 3 and the absorbent body 4, it is disposed between the second sheet and the absorbent body 4.

  The fiber assembly sheet 15 made of the tow is covered with the liquid permeable surface sheet 3 and the fiber assembly sheet 15 made of tow in the concave groove 22 on both side surfaces and the bottom surface of the concave groove 22. The cross-sectional area of the groove 22 can be reduced by significantly improving the diffusibility of urine in the longitudinal direction in the groove 22. That is, in the present invention, in order to reduce the cross-sectional area of the groove without reducing performance, if the diffusibility of urine in the longitudinal direction can be further improved in the groove, the cross-sectional area of the groove 22 can be reduced. By observing that the same performance should be maintained, by utilizing the high diffusibility of the fiber assembly made of tow, the urine flowing into the concave groove 22 can be quickly diffused in the longitudinal direction before overflowing. Thus, the cross-sectional area of the concave groove 22 can be reduced.

  In selecting a material for improving urine diffusibility, the present inventor also examined a non-woven fabric or the like in which the fiber orientation is unidirectional. However, the liquid diffusion performance was insufficient, and attention was paid to a tow which is a bundle of continuous filaments.

  The tow has the property of rapidly diffusing the liquid through the space between the tow fibers by capillary action when the liquid is absorbed. Accordingly, when both side surfaces and bottom surface of the groove 22 are covered with the two layers of the liquid permeable surface sheet 3 and the fiber assembly sheet 15 made of the tow, a large amount of urine is discharged into the groove 22 in one place. Even if it is made, by utilizing the high diffusibility of the fiber assembly sheet 15 made of tow, the cross-sectional area of the groove 22 can be quickly diffused in the longitudinal direction before overflowing the urine flowing into the groove 22. It is possible to maintain the same performance even if it is reduced.

  The liquid diffusion length in the fiber orientation direction of the fiber assembly sheet 15 made of the tow is 40 mm or more, preferably 50 mm or more, more preferably 60 mm or more. When the liquid diffusion length is 40 mm or more, the absorbed liquid can be quickly diffused in the orientation direction of the tow fibers. This liquid diffusion length can be measured by the measuring method described in Japanese Patent Laid-Open No. 2012-213480. Specifically, (1) A sample having a size of 100 × 100 mm is placed on a wire mesh, for example, one having φ: 0.5 mm and pitch: 3 mm. (2) The lower end of the dropping funnel containing 40 g of physiological saline is fixed at the center of the test and at a height of 10 mm from the sample, and the physiological saline is dropped onto the sample in about 5 seconds. (3) After about 30 seconds, the liquid diffusion length (the fiber orientation direction and its orthogonal direction), which is the length of diffusion of the physiological saline, is measured.

  The basis weight of the fiber assembly sheet 15 made of the tow is preferably 10 to 70 g / m <2> and more preferably 20 to 50 g / m <2>.

As shown in FIG. 1, the fiber assembly sheet 15 made of the tows is preferably disposed so as to cover the entire upper surface side of the absorbent body 4. By adopting such an arrangement mode, the following advantages can be further obtained.
(1) Since it is bulky and has many gaps between fibers, the skin feel is soft and fluffy.
(2) Since the compression / restoration property is high, even if the product is highly compressed in the package or stored for a long time in a folded state, the compression / restoration property is good at the time of mounting, so that the original soft feeling can be obtained.
(3) Even when water is absorbed, the distance between the skin and the absorbent body is maintained, and the liquid retainability on the surface is small. Therefore, even when body pressure is applied, liquid return is small and a light feeling can be maintained.
(4) Even when a force sufficient to twist the absorber is applied, the tow fibers, which are bundles of continuous filaments, are restrained, so that cracking and twisting of the absorber can be suppressed.

  By the way, in this incontinence pad 1, as shown in FIG. 2, a superabsorbent resin 8 is mixed inside the absorbent body 4, and a fiber assembly sheet 15 made of the absorbent body 4 and the tow is used. A super absorbent resin 14 is sprayed between them. Therefore, even when the urine absorbed in the absorbent body 4 while diffusing along the concave groove 22 cannot be held inside the absorbent body and is likely to ooze out to the skin side, the fiber assembly composed of the absorbent body 4 and the tow Since it is absorbed and held by the superabsorbent resin 14 dispersed between the body sheet 15 and the urine collected in the absorbent body 4 can be reliably prevented from returning to the surface side of the liquid-permeable surface sheet 3, It becomes possible to maintain the smoothness of the surface material after water absorption. Further, the fiber aggregate sheet 15 made of the tow has a drawback that the liquid permeability tends to be lowered because the fiber aggregate sheet 15 is crushed and thinned after absorbing the liquid. By sucking the body fluid from the assembly sheet 15, the liquid permeability of the fiber assembly sheet 15 made of tow can be maintained.

The superabsorbent resin 14 can be composed of a single superabsorbent resin or a mixture of superabsorbent resin and absorbent fibers. When composed of a single highly water-absorbing resin, it is excellent in water absorption of urine, and when it is composed of a mixture with the water-absorbing resin, it is excellent in water permeability of urine. Basis weight of the super absorbent polymer ^{14, 50g / m 2 ~500g / m} 2, preferably from ^{100g / m 2 ~400g / m 2} .

  The superabsorbent resin contained in the superabsorbent resin 14 is in the form of granular powder in the same manner as the superabsorbent resin 8 contained in the absorber 4. In addition, as such a superabsorbent resin, as in the superabsorbent resin 8 included in the absorbent body 4, for example, a polyacrylate cross-linked product, a self-crosslinked polyacrylate, an acrylate-vinyl acetate copolymer Examples thereof include saponified products of cross-linked polymers, cross-linked products of isobutylene / maleic anhydride copolymer, cross-linked polysulfonates, and water-swellable polymers 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 of the highly water-absorbent resin having the water-absorbing performance, it is possible to adjust the absorption ratio (water absorption power) and the absorption speed by adjusting the cross-linking density and the cross-linking density gradient.

  The spray range of the superabsorbent resin 14 can be the entire surface of the fiber assembly sheet 15 made of tow, but the longitudinal groove forming range of the concave groove 22 + the dimension of 10 to 30 mm on each side is added. It may be set to a range.

  On the other hand, as shown in FIGS. 6 (A) to 6 (C), staggered, lattice-shaped or diagonal lattice-shaped embosses 4a to 4c are preferably formed on the skin surface side of the absorbent body 4. . Accordingly, the liquid flow can be slowed when the discharged urine flows laterally, and the superabsorbent resin 8 dispersed between the absorbent body 4 and the fiber assembly sheet 15 made of tow is absorbed by the absorbent body 4. It is preferable because it is difficult to move in the front-rear and left-right directions by the staggered, lattice-like or diagonal lattice-like embosses 4a to 4c formed on the skin surface side. Therefore, it is possible to prevent the highly water-absorbing resin 14 from gathering at one place and expanding due to the water absorption, thereby significantly impairing the wearing feeling.

[Other examples]
(1) In the above embodiment, the fiber assembly sheet 15 made of the tow is arranged so as to cover the entire upper surface side of the absorbent body 4 as shown in FIG. 7, it may be arranged not in the entire upper surface of the absorber 4 but in a partial range including the concave groove 22. An essential problem of the present invention is to reduce the cross-sectional area of the concave groove, and even if the fiber assembly sheet 15 made of the tow is partially disposed in the range including the concave groove 22, The urine flowing into the groove 22 can be quickly diffused in the longitudinal direction, and the initial purpose can be achieved.

(2) The concave groove 22 can be arranged in various forms. As shown in FIG. 1, it is preferable to form only one groove in the center portion in the pad width direction corresponding to the urine discharge site H and in the middle portion in the longitudinal direction, as shown in FIG. As shown in FIG. 8A, a plurality of strips may be formed apart from each other in the pad width direction. Alternatively, as shown in FIG. May be. When a plurality of strips are formed, the urine diffusion effect can be more reliably enhanced even when a large amount of urine is discharged at once. Moreover, when it forms in a discontinuous line shape, the crushing when the ditch | groove 22 receives external forces, such as leg pressure, from the width direction both sides can be prevented more reliably. When forming a plurality of strips separated in the pad width direction, as shown in FIG. 8 (A), it is formed at the center in the pad width direction and arranged so that one or more strips are formed on both sides thereof. Is preferred.

(3) Further, the planar shape of the concave groove 22 may be formed with a uniform width along the longitudinal direction of the pad as shown in FIG. 1, or with different groove widths as shown in FIG. It may be formed. In FIG. 9A, a widened portion 22a with an enlarged groove width is provided at the front end portion of the concave groove 22 in the pad longitudinal direction. By providing the widened portion 22a, a temporary storage space for urine can be expanded, and even when a large amount of urine is dripped at a time such as urge incontinence, the urine can be reliably received by the groove 22 It becomes. The widened portion 22a may be provided at the end portion on the rear side of the pad as shown in FIG. 9B, or may be provided at the front and rear end portions as shown in FIG. 9C.

(4) Further, as shown in FIG. 10, the concave groove 22 may be provided with one or a plurality of branch portions 22b and 22c. By providing the branch portions 22b and 22c, the urine temporarily stored in the concave groove 22 is diffused along the concave groove 22 to a wide area of the absorbent body 4, and the urine is spread over a wider area of the absorbent body 4. Can absorb. In the example shown in FIGS. 10A to 10C, as the branching portion 22b, the front side, the rear side, or the front side and the rear side in the longitudinal direction of the pad extend outward from both side edges of the concave groove 22, respectively. There are provided a plurality of inclining toward the end in the longitudinal direction of the pad, three each on the left and right in the illustrated example. Further, in the example shown in FIGS. 10D to 10F, as the branching portion 22c, a plurality of concave grooves 22 are radially formed on the front end, the rear end, or the front end and the rear end in the longitudinal direction of the pad. In the example shown, the one that is branched into five is provided.

  In addition, when providing the said absorber recessed part 20 in the formation planned part of the recessed groove 22 of the absorber 4 previously, the absorber recessed part 20 is provided along the shape of the said recessed groove 22.

(5) In the above embodiment, the absorber recess 20 is formed in a bottomed groove shape as shown in FIG. 2, but as shown in FIG. 11, from the front side to the back side. You may form in the slit shape which penetrated. When the absorber concave portion 20 is slit-shaped, the embossed portion 21 has a liquid-impervious back sheet 2 that penetrates the absorber concave portion 20 disposed on the bottom surface of the absorber concave portion 20, as shown in FIG. To be applied to. Even when the absorbent body recess 20 is formed in a slit shape and the absorbent body 4 is not interposed at the bottom of the groove 22, urine is formed by the fiber assembly sheet 15 made of tows present on both side surfaces and the bottom surface of the groove 22. Can be quickly diffused along the longitudinal direction.

  DESCRIPTION OF SYMBOLS 1 ... Incontinence pad, 2 ... Impermeable back sheet, 3 ... Liquid permeable surface sheet, 4 ... Absorber, 5 ... Encapsulating sheet, 7 ... Side nonwoven fabric, 8 ... Super absorbent polymer, 10 ... Inside solid gather , 11 ... outer three-dimensional gather, 12 · 13 ... thread-like elastic elastic member, 14 ... super absorbent resin, 15 ... fiber assembly sheet made of tow, 20 ... absorber recess, 21 ... embossed part, 22 ... recessed groove

Claims (5)

In the absorbent article in which an absorbent body is interposed between the liquid-permeable top sheet and the back sheet,
The absorbent body has a groove-shaped or slit-shaped absorbent body on the surface of the liquid-permeable surface sheet side along the longitudinal direction of the absorbent article and over the longitudinal range including the urine discharge site without being squeezed. With a recess,
Between the liquid-permeable surface sheet and the absorbent body, a fiber assembly sheet made of tow is disposed in a state where the fiber direction is the longitudinal direction of the absorbent article,
In the state where the fiber assembly sheet made of the tow and the liquid-permeable surface sheet are laminated on the upper surface of the absorber, the absorber concave portion is formed on the absorber concave portion with respect to the bottom surface of the absorber concave portion from the surface side of the liquid-permeable surface sheet. by applying embossed along concave groove in the longitudinal direction are formed on the skin side, both side surfaces and the bottom surface of the recessed groove is covered by a fiber aggregate sheet comprising the toe and the liquid-pervious topsheet Absorbent article characterized by being made.   The absorbent article according to claim 1, wherein a superabsorbent resin is mixed inside the absorbent body, and the superabsorbent resin is dispersed between the absorbent body and a fiber assembly sheet made of tow.   The absorbent article according to any one of claims 1 and 2, wherein a staggered, lattice-like or oblique lattice-like emboss is formed on the skin surface side of the absorbent body.   The absorbent article according to any one of claims 1 to 3, wherein the fiber assembly sheet made of the tow is disposed on the entire upper surface side of the absorbent body. The fiber assembly sheet composed of the tow has a surface on the skin side including a number of ridges and a plurality of grooves along the fiber direction, and the fiber assembly sheet composed of the tow is composed of fibers of tows. The absorptive article according to any one of claims 1 to 4 which has an entanglement point formed by entanglement.

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