JP6457780B2 - 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. It has been known.

  In the absorbent article, a resin film (so-called mesh sheet) in which a large number of apertures are formed as the liquid-permeable surface sheet is used in order to satisfy the dry touch feeling on the skin and increase the urine absorbability. Many things are offered to the market. Examples of the absorbent article using this mesh sheet include the following Patent Documents 1 and 2.

  In addition, many improvements have been made to this type of absorbent article, and in particular, a temporary storage and urine diffusion means for receiving urine discharged at a time, such as an incontinence pad, in a small area and quickly diffusing it. As a method, various types of grooves having grooves formed along the longitudinal direction on the skin side have been proposed (for example, Patent Documents 3 and 4 below).

JP 2004-298422 A JP 2003-284742 A Japanese Patent No. 5105884 JP 2009-112590 A

  When a nonwoven fabric is used as the liquid-permeable surface sheet, the entire surface becomes a liquid-permeable portion. However, when a mesh sheet as disclosed in Patent Documents 1 and 2 is used, the mesh sheet has a normal porosity. Since it is 5% to 20%, there is a limit to the amount of urine passing through, and it was not possible to cope with urine that dripped out at once. For this reason, even when a groove as described in Patent Documents 3 and 4 is provided, the amount of liquid passing through the groove is limited, so that urine may overflow from the groove and leakage may occur. It was.

  In addition, in order to quickly absorb the urine in the groove into the absorbent body, it is necessary to quickly flow the urine in the longitudinal direction of the groove and cause the absorbent body to absorb the urine in the process of flowing through the groove. The urine did not flow easily along the longitudinal direction of the groove.

  SUMMARY OF THE INVENTION Accordingly, a main object of the present invention is to provide an absorbent article capable of improving liquid permeability, preventing leakage, and absorbing urine quickly as a structure in which urine easily flows along the longitudinal direction of the groove.

In order to solve the above problems, as the present invention according to claim 1, an absorbent body is interposed between the liquid-permeable top sheet and the back sheet, and a groove is formed along the longitudinal direction on the skin side. And in the absorbent article in which the liquid-permeable surface sheet is disposed along the concave groove,
The concave groove is a concave groove for inflow of urine that is formed in the middle portion in the longitudinal direction in the center in the width direction corresponding to the urine excretion site,
The liquid-permeable surface sheet is made of a resin film in which a large number of apertures are formed, and is folded in a plurality along a fold extending in the longitudinal direction of the absorbent article in at least a width range including the concave groove. A bellows portion is formed, and a large number of holes are formed in the side surface portion connecting the mountain fold portion and the valley fold portion of the bellows portion, so that the holes existing per unit area in the concave groove are formed. The total area is increased ,
Within the concave groove, the liquid-permeable topsheet is bonded to the bottom of the concave groove by hot melt adhesive or a plurality of pin-shaped or dot-shaped embosses, and the wave-shaped portion of the bellows is maintained while maintaining the wave shape. By disposing the liquid surface sheet along the groove, the absorbent article is provided in which the bellows portion is disposed along the bottom surface and both side surfaces of the groove .

In the first aspect of the present invention, only one groove is formed in the central portion in the width direction corresponding to the urine excretion site and in the middle portion in the longitudinal direction. Further, even when a resin film having a large number of apertures is used as the liquid-permeable surface sheet, the urine passage in the concave groove is achieved by forming the bellows portion at least in the width direction range including the concave groove. The liquid volume is secured. Specifically, in the width direction range including at least the concave groove of the liquid-permeable surface sheet, a side surface portion that forms a folded bellows portion and connects the mountain fold portion and the valley fold portion of the bellows portion. A large number of apertures are formed. As a result, the total area of the openings existing per unit area in the concave groove is increased. Then, in the groove, the liquid-permeable surface sheet is bonded to the bottom of the groove by hot melt adhesive or a number of pin-shaped or dot-shaped embosses, and the corrugated portion remains corrugated. By arranging the liquid-permeable surface sheet along the concave groove, the bellows portion is arranged along the bottom surface and both side surfaces of the concave groove.
Accordingly, the amount of urine passing through the opening can be increased in the concave groove, and it is possible to cope with urine that is dripped at a time, and urine overflows from the concave groove and leaks. Can be prevented.

In the present invention, the accordion portion is formed on the bottom surface and both side surfaces of the concave groove by arranging the liquid-permeable surface sheet along the concave groove while maintaining the corrugated portion of the bellows portion. For this reason, the total area of the openings is increased on the bottom surface and both side surfaces of the groove, and the urine flow rate is increased. In order to dispose the liquid-permeable surface sheet along the groove while maintaining the corrugated portion of the bellows, a method of applying an adhesive to the bottom surface of the groove and bonding the liquid-permeable surface sheet to the absorber side Alternatively, a method of applying a number of pin-like embosses or dot-like embosses from the outer surface side of the liquid-permeable surface sheet can be used.

  In addition, since the bellows part is formed by being folded in a plurality along a fold extending in the longitudinal direction of the absorbent article, urine in the concave groove is in the groove longitudinal direction along the fold of the bellows part. It becomes easy to flow, and urine is quickly absorbed into the absorber through the opening in the process of flowing along the longitudinal direction of the groove.

  As the present invention according to claim 2, the total area of the openings existing per unit area is the total area of the openings existing per unit area when the liquid-permeable surface sheet is arranged in a plane. On the other hand, the absorbent article according to claim 1, which is 1.2 to 5 times.

  In the second aspect of the invention, the ratio for increasing the total area of the apertures is defined. Specifically, the total area of the apertures present per unit area is 1.2% of the total area of the apertures present per unit area when the liquid-permeable surface sheet is arranged in a plane. Double to 5 times. For this reason, even with a mesh sheet that is usually formed with an aperture ratio of 5 to 20%, the total area of the aperture is apparently increased, and the amount of urine passing through the aperture can be increased.

As the present invention according to claim 3, for holding the bellows shape of the bellows portion, the claims shape maintainer connecting folds adjacent the bellows portion is formed 1, 2 absorbent according to any one Articles are provided.

In the invention according to claim 3 , the bellows portion of the bellows portion is held in the manufacturing process of the absorbent article or while the absorbent article is worn so that the corrugated portion of the bellows portion folded in plural is not released. The shape holding part which connects the creases which adjoin the part is provided.

As the present invention according to claim 4 , there is provided the absorbent article according to claim 3 , wherein the shape holding portion is formed in a mesh shape.

In the invention according to claim 4 , the shape holding portion is provided in a mesh shape in order to effectively hold the bellows shape of the bellows portion.

  As described above in detail, according to the present invention, liquid permeability is improved, leakage can be prevented, and urine can be absorbed quickly by adopting a structure in which urine easily flows along the longitudinal direction of the groove.

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 expansion perspective view of the bellows part 17 of the liquid-permeable surface sheet 3. FIG. It is an expanded view of the incontinence pad 1 which concerns on another example of a form. FIG. 6 is a cross-sectional view (part 1) illustrating a processing step of the concave groove 22; FIG. 6 is a cross-sectional view (part 2) illustrating the processing step of the concave groove 22; FIG. 6 is a cross-sectional view (part 3) illustrating the processing step of the concave groove 22; It is process drawing which shows the manufacturing process of the liquid-permeable surface sheet. It is a figure which shows the recessed part formation roll 32. FIG. It is a top view of the synthetic resin film sheet 31 in which the recessed part was formed with the recessed part formation roll. It is a figure which shows the upper stage roll 37 of the extending | stretching gear roll 36. FIG. It is a figure which shows the lower stage roll 38 of the extending | stretching gear roll 36. FIG. FIG. 4 is a cross-sectional view showing a state in which an extension gear roll 36 is engaged. (A)-(C) are the expanded views 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 a top view of the incontinence pad 1 which concerns on another Example. It is a top view of the incontinence pad 1 which concerns on another Example. It is a principal part expanded sectional view 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. 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, and a substantially side edge portion of the absorbent body 4 as an upright base end, and provided at least in a predetermined section in the longitudinal direction so as to include the urine discharge site H. It is mainly composed of a pair of left and right three-dimensional gathers BS, side nonwoven fabrics 7 and 7 forming the BS, and around the absorbent body 4, the liquid-impervious back sheet 2 and the transparent material are disposed at the longitudinal edges. Liquid surface sheet 3 and The liquid-impervious back sheet 2 and the side nonwoven fabric whose outer edge portions are bonded by an adhesive such as hot melt or an adhesive means such as heat seal, and whose both side edge portions extend laterally from the absorbent body 4. 7 is bonded by an adhesive such as hot 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, the liquid-permeable surface sheet 3 is composed of a resin film in which a large number of apertures 15 are formed. As this material sheet, for example, an olefin resin such as polyethylene or polypropylene is preferably used, but a polyamide resin such as polyester, nylon, EVA or the like can also be used. The liquid permeable top sheet 3 will be described in detail later.

  The absorbent body 4 is composed of absorbent fibers such as cotton-like pulp and a highly water-absorbing 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 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 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.

  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.

[About the groove 22]
In the incontinence pad 1, 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.

  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. An absorbent body recess 20 is formed in a portion where the groove 22 is to be formed, and the liquid-permeable surface sheet 3 is disposed along the absorber recess 20, or along the absorber recess 20. The embossed portion 21 that squeezes the upper constituent member from the absorbent body 4 from the surface side (skin surface side) of the liquid-permeable surface sheet 3 prevents deformation of the concave groove 22 due to leg pressure. This is desirable because it can be done.

  In the incontinence pad 1, as shown in FIG. 2, the absorbent body 4 has urine drainage on the skin side (liquid-permeable surface sheet 3 side) surface in advance in the portion where the concave groove 22 is to be formed. Along the longitudinal direction including the portion H, an absorbent recess 20 having a groove shape or a slit shape, in the illustrated example, is formed 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 not compressed, and (A) stacked fiber, or (B) the lower layer absorbent body 4 a formed with the thickness of the bottom of the absorbent body recess 20, 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 being formed in a discontinuous line shape spaced apart in the pad longitudinal direction (FIG. 16 to FIG. 16). (See FIG. 18). 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 5 to 30 mm. 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 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} . Also in this absorber portion, the water-absorbing polymer 8 is dispersed and mixed with a predetermined basis weight.

  As shown in FIG. 4 (B), when the absorbent body 4 is composed of a laminate of an upper layer absorbent body 4b and a lower layer absorbent body 4a, pulp and high water absorption constituting the upper layer absorbent body 4b and the lower layer absorbent body 4a. The basis weight and ratio of the conductive polymer 8 may be the same or different. Further, the upper layer absorber 4b and the lower layer absorber 4a may be integrally surrounded by the encapsulating sheet 5 in a state where the upper layer absorber 4b and the lower layer absorber 4a are laminated, or the upper layer absorber 4b and the lower layer absorber 4a. The absorber 4a may be stacked after being surrounded by separate encapsulating sheets 5 respectively. Further, a paper material such as tissue or a liquid-permeable sheet material such as a nonwoven fabric may be disposed between the upper layer absorber 4b and the lower layer absorber 4a.

  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.

[About liquid-permeable surface sheet 3]
As the liquid-permeable surface sheet 3, as shown in FIG. 1, a resin film (plastic sheet) in which a large number of apertures 15, 15... Are formed is used. The urine discharged to the liquid-permeable surface sheet 3 can penetrate into the absorbent body 4 through the openings 15.

The diameter of the aperture 15 is 0.05 to 3.0 mm, preferably 0.1 to 2.0 mm, more preferably 0.5 to 1.5 mm, and the number of apertures is 100 to 500 / cm ^2. Preferably, it is desirable to set it to about 200 to 400 pieces / cm ² . The number of apertures is the number per unit area in a flat state where the liquid-permeable surface sheet 3 is not folded into a bellows shape. In order to form the apertures 15, the synthetic resin sheet is softened near the softening temperature and is positioned on the upper surface of the support body having a large number of apertures, and is sucked from below the support body. A method of pressurizing air pressure from the top surface, a method of stretching and opening the sheet material after engraving a large number of slits in the synthetic resin sheet material, and a knurled roll and a smooth surface as described in detail later After forming a fine recessed part by passing between the preheating rolls which have this, it can form by appropriate methods, such as the method of breaking and opening the said recessed part by extending | stretching greatly with an extending | stretching gear roll.

  The range in which the opening 15 is formed may be provided over the entire surface of the liquid-permeable surface sheet 3, or may be provided only in the center in the width direction including at least the concave groove 22. The range in which the aperture 15 is formed is substantially the same as or narrower than the range in which the bellows portion 17 described later is formed.

  Further, the liquid-permeable surface sheet 3 is alternately mountain-folded along a large number of fold lines 16, 16... Extending in the longitudinal direction of the pad and spaced apart in the pad width direction in at least the width direction range including the concave groove 22. The bellows portion 17 is formed by repeating the valley folding and is folded into a plurality of portions.

  As shown in FIG. 5, the bellows portion 17 has a structure in which a mountain fold portion 16 a protruding toward the skin side and a valley fold portion 16 b protruding toward the non-skin side are alternately and repeatedly formed. The mountain folds 16a and the valley folds 16b extend linearly along the pad longitudinal direction of the liquid-permeable surface sheet 3, and are arranged in parallel while being spaced apart in the pad width direction. The mountain fold portion 16a and the valley fold portion 16b are provided in a range extending over substantially the entire length in the pad longitudinal direction.

  The cross-sectional shape of the bellows portion 17 is formed in a substantially wave shape as shown in FIG. In the illustrated example, it is formed in a wave shape having a substantially trapezoidal cross section, but it can also be formed in a wave shape such as a V shape, a U shape, or a U shape.

  The height of the bellows portion 17 (the height from the bottom of the valley fold 16b to the top of the mountain fold 16a) is 0.5 mm to 5 mm, preferably 1 mm to 3 mm. The pitch of the bellows portion 17 (the distance between the centers of the adjacent mountain fold portions 16a and 16a or the distance between the centers of the adjacent valley fold portions 16b and 16b) is 0.3 mm to 3 mm, preferably 0.5 mm to 2 mm. It is good to do. The height and pitch of the bellows portion 17 do not have to be constant, and can be appropriately changed depending on the portion of the liquid-permeable surface sheet 3. For example, the total area of the openings 15 existing per unit area in the recessed groove 22 may be increased by making the pitch smaller than both sides at the center in the pad width direction.

  As shown in FIG. 1, the range in which the bellows portion 17 is formed may be only the center portion in the width direction including at least the concave groove 22, or as shown in FIG. 6, The whole surface may be sufficient. By forming the bellows portion 17 in a range including at least the concave groove 22, the total area of the openings 15 existing per unit area in the concave groove 22 can be increased, and the amount of liquid passing through the openings 15 is increased. Can be achieved. Moreover, when the bellows part 17 is formed over the whole surface of the liquid-permeable surface sheet 3, the contact area with the skin surface of the liquid-permeable surface sheet 3 can be reduced in a wider range, and a feeling of sticking to the skin And the feeling of texture can be improved.

  In the example shown in FIG. 1, the range in which the opening 15 and the bellows portion 17 are formed is only the range in which the concave groove 22 is formed and the central portion in the width direction up to a predetermined range on both sides thereof. The opening 15 and the bellows portion 17 are not formed on both sides in the outer width direction.

  As shown in FIG. 5, the apertures 15, 15... Are formed on the side surface connecting the top of the mountain fold 16 a and the bottom of the valley fold 16 b of the bellows 17, and the top of the mountain fold 16 a. It is not formed at the bottom of the valley fold 16b. As a result, urine can be transmitted to the absorber 4 through the openings 15 formed on both side surfaces of the valley fold 16b, and an opening is formed at the top of the mountain fold 16a and the bottom of the valley fold 16b. By not forming, the reverse of the urine absorbed by the absorber 4 can be prevented, and the smoothness of the surface is improved.

  By forming a large number of apertures 15 in the side surface of the bellows portion 17, the total area of the apertures 15 existing per unit area in the concave groove 22 is increased. The total area of the apertures 15 existing per unit area means that the liquid permeable surface sheet 3 is folded into a plurality of bellows in the bellows portion 17 and is present in a flat planar unit area. The apertures 15, 15... To be summed are the areas along the corrugated portion 17 along the wave shape (along the surface of the liquid-permeable surface sheet 3).

  In other words, the total area ΣA of the apertures 15 existing per unit area in the concave groove 22 is obtained when the liquid-permeable surface sheet 3 is arranged in a plane (the state folded in a bellows shape is expanded in the width direction). When arranged flat), it is larger than the total area ΣB of the apertures 15 existing in the same unit area. That is, by folding the liquid-permeable surface sheet 3 in a bellows shape, the number (area) of the openings 15 existing per unit area is increased as compared with the case where the liquid-permeable surface sheet 3 is arranged on a plane.

  The total area ΣA of the apertures 15 existing per unit area in the concave groove 22 is the total area ΣB of the apertures 15 existing per unit area when the liquid-permeable surface sheet 3 is arranged in a plane. In contrast, 1.2 times to 5 times (ΣA = 1.2ΣB to 5ΣB), preferably 1.5 times to 3 times (ΣA = 1.5ΣB to 3ΣB). If ΣA is less than 1.2 times ΣB, the effect of increasing the amount of liquid flow cannot be expected to be so great. If ΣA is more than 5 times, the interval between the folds 16 and 16 is too narrow and urine does not easily penetrate.

  With the configuration described above, the incontinence pad 1 can increase the amount of urine passing through the opening 15 in the concave groove 22 and can cope with urine discharged at a time. Become. For this reason, it becomes possible to prevent urine from overflowing from the concave groove 22 and leaking.

  Further, since the bellows portion 17 is formed by folding the liquid-permeable surface sheet 3 into a plurality along the fold line 16 extending in the longitudinal direction of the incontinence pad 1, the urine in the concave groove 22 causes the bellows portion 17. It becomes easy to flow in the longitudinal direction of the groove along the folds 16 (valley folds 16b, 16b...), And is quickly absorbed by the absorber 4 through the openings 15.

  When forming the concave groove 22, as shown in FIG. 2, the liquid-permeable surface sheet 3 is arranged along the concave groove 22 while maintaining the corrugated portion 17 in the concave groove 22. The bellows portion 17 is preferably disposed along the bottom surface and both side surfaces of the concave groove 22. As a result, the bellows portion 17 is formed on the entire circumferential surface in the concave groove 22, and the liquid permeability of urine can be effectively increased through the numerous openings 15 formed in the bellows portion 17.

  In order to arrange the liquid-permeable surface sheet 3 along the concave groove 22 while maintaining the wave shape of the bellows portion 17, the liquid-permeable surface sheet 3 is provided on the skin side surface of the absorbent body 4 as shown in FIG. After the lamination, from the skin surface side of the liquid-permeable surface sheet 3, a state in which the liquid-permeable surface sheet 3 is deformed so as not to be crushed by the bottom surface of the recessed groove 22 by the embossed convex portion 24. Thus, it is possible to use a method of joining the bottom of the absorber recess 20 and the liquid-permeable surface sheet 3 by a joining means such as a hot melt adhesive. Further, as shown in FIG. 8, the pin-like embossing or the dot-like embossing 25 can be used to perform a number of pin-like or dot-like embossing.

  On the other hand, as shown in FIG. 9, the concave groove 22 embosses the absorber recess 20 from the surface side of the liquid permeable surface sheet 3 in a state where the liquid permeable surface sheet 3 is laminated on the absorber 4. Accordingly, the bellows portion 17 can be prevented from being crushed and formed on the bottom surface of the concave groove 22. Thereby, the concave groove 22 is more reliably formed, and the function as a temporary urine storage location is effectively exhibited. In this case, although the flow rate of urine from the bottom surface of the concave groove 22 is reduced, the bellows portions 17 are formed on both side surfaces of the concave groove 22, so the liquid flow rate from both side surfaces is small. Secured.

  As shown in FIG. 1, in order to hold the bellows shape of the bellows portion 17, it is preferable to form a shape holding portion 18 that connects the adjacent folds 16, 16 of the bellows portion. The shape holding portion 18 is configured to prevent the wave shape of the bellows portion 17 folded in a plurality from being released when receiving an external force in the manufacturing process of the incontinence pad 1 or receiving an external force while the incontinence pad 1 is attached. It is provided to maintain the shape. The shape holding part 18 is continuous with the tops of the adjacent mountain folds 16a, 16a... Of the bellows part 17 or the bottoms of the adjacent valley folds 16b, 16b. The shape holding portion 18 is preferably continuous with the apex portions of the adjacent mountain fold portions 16a, 16a... Of the bellows portion 17 in order to easily maintain the wave shape of the bellows portion 17 with respect to external force.

  As shown in FIG. 1, a plurality of one-side shape holding portions 18a that are substantially along the pad width direction and are inclined to one side of the pad longitudinal direction are formed at intervals in the pad longitudinal direction. A plurality of other side shape holding portions 18b that are substantially along the pad width direction and are inclined to the other side of the pad longitudinal direction are formed at intervals in the pad longitudinal direction, and the one side shape holding portion 18a and the other side shape holding portion are formed. It is preferable to form a mesh by intersecting the portion 18b.

  The inclination angle of the one-side shape holding portion 18a with respect to the pad width direction line is set in a range larger than 0 ° and smaller than 90 °. Further, the inclination angle of the other-side shape holding portion 18b with respect to the pad width direction line is set in a range larger than 0 ° and smaller than 90 °.

  In the example shown in FIG. 1, the shape of each mesh surrounded by the one-side shape holding portion 18a and the other-side shape holding portion 18b is a substantially rhombus, but may be a polygon such as a triangle, a quadrangle, or a pentagon. In addition, the shape holding unit 18 is configured as a straight line in the illustrated example, but the shape of each mesh may be circular, elliptical, or the like by using a curved line. Further, the shape holding portions 18 do not cross the shape holding portions having different inclination directions, but are formed in a plurality of lines, curves, wavy lines, etc. that are formed along the pad width direction and at intervals in the pad longitudinal direction. You may comprise.

  Next, the manufacturing method of the said liquid-permeable surface sheet 3 is demonstrated. In order to manufacture the liquid-permeable surface sheet 3 having the bellows portion 17, the method disclosed in Japanese Patent Application Laid-Open No. 2013-212153 can be used. The method disclosed in the publication is as follows.

  The method disclosed in the publication includes a step (1B) of forming a recess in the synthetic resin film sheet and a step (2B) of gear-stretching the synthetic resin film sheet.

(Process 1B)
As shown in FIG. 10, the synthetic resin film sheet 31 supplied from the roll 30 passes through the recess forming roll 32, and the recess 33 is formed in the synthetic resin film sheet 31 (see FIG. 12). The recess forming roll 32 includes a knurling roll 34 and a preheating roll 35 having a smooth surface.

  FIGS. 11A and 11B are diagrams illustrating an example of the knurled roll 34. FIG. 11A is a view showing the entire knurled roll 34, and FIG. 11B is an enlarged view of a portion 34 a having irregularities on the outer peripheral surface of the knurled roll 34. FIG. 11C shows an example of the preheating roll 35 having a smooth surface. On the surface 34 a of the knurled roll 34, lattice-like convex portions 34 b are provided. As a result, a diamond-shaped recess 34 c is formed on the surface of the knurled roll 34.

  The preheating roll 35 having a smooth surface is maintained at a temperature of 70 ° C. to 100 ° C., and heats the supplied synthetic resin film sheet 31. Thereby, the synthetic resin film sheet 31 becomes soft and is easy to form.

  When the synthetic resin film sheet 31 passes between the knurled roll 34 and the preheating roll 35, the portion of the synthetic resin film sheet 31 that contacts the lattice-shaped convex portion 34b receives a strong pressure in the thickness direction. Thereby, as shown in FIG. 12, fine recesses 33 are formed in the synthetic resin film sheet 31. The recess 33 is preferably provided over the entire synthetic resin film sheet 31.

(Process 2B)
As shown in FIG. 10, a region corresponding to the bellows portion 17 of the liquid-permeable surface sheet 3 in the synthetic resin film sheet 31 by passing the synthetic resin film sheet 31 having a recess formed in the stretched gear roll 36. Is bent to produce a synthetic resin film sheet 31 in which the bellows portion 17 is formed. In the synthetic resin film sheet 31, the bellows portion 17 extends in the machine direction (MD) and is juxtaposed in the width direction. In the synthetic resin film sheet 31, the bellows portion 17 extending in the machine direction is interrupted at a plurality of locations. That is, in the synthetic resin film sheet 31, the bellows part 17 is formed discontinuously, and the synthetic resin film sheet 31 is not bent at the discontinuous part. This discontinuous portion corresponds to the shape holding portion 18 of the liquid-permeable surface sheet 3.

  The drawing gear roll 36 includes an upper roll 37 and a lower roll 38. 13A is a view for explaining the upper roll 37 of the stretched gear roll 36, and FIG. 13B is a view for explaining the gear teeth 37a arranged on the outer peripheral surface of the upper roll 37. FIG. 13C is a BB line arrow view of FIG. 13B. The gear teeth 37 a extend discontinuously in the circumferential direction of the upper roll 37. That is, the gear teeth 37a extending in the circumferential direction of the upper roll 37 are interrupted at a plurality of points in the middle. A discontinuous portion corresponding to the shape holding portion 18 of the liquid-permeable surface sheet 3 is formed by the portion 37b where the gear teeth 37a are interrupted. The portions 37b where the gear teeth 37a are interrupted are arranged so as to be aligned on a straight line in an oblique direction with respect to the direction in which the gear teeth 37a extend.

  14A is a view for explaining the lower roll 38 of the stretched gear roll 36, and FIG. 14B is a view for explaining the gear teeth 38a arranged on the outer peripheral surface of the lower roll 38. FIG. 14C is a view taken along the line CC of FIG. 14B. The gear teeth 38 a extend in the circumferential direction of the lower roll 38. The lower roll 38 is not interrupted at a plurality of places on the way like the upper roll 37. The width of the gear teeth 38a is, for example, equal to the width of the gear teeth 37a of the upper roll 37, and the distance between the centers of the adjacent gear teeth 38a is, for example, equal to the distance between the centers of the gear teeth 37a of the upper roll 37.

  When the synthetic resin film sheet 31 passes through the stretched gear roll 36, an opening corresponding to the opening 15 of the liquid-permeable surface sheet 3 is formed in the recess 33 of the synthetic resin film sheet 31.

  With reference to FIG. 15, the principle that an opening is formed in the synthetic resin film sheet 31 when the synthetic resin film sheet 31 is passed through the stretched gear roll 36 will be described. The synthetic resin film sheet 31 is greatly stretched at a portion 39 where the gear teeth 37a of the upper roll 37 and the gear teeth 38a of the lower roll 38 are engaged with each other. The portion where the concave portion 33 (see FIG. 12) is formed in the concave portion forming step described above is a portion where the synthetic resin film sheet 31 is thin and the scratches are given by the lattice-shaped convex portions 34b of the knurled roll 34. Therefore, the strength is weak, and the concave portion 33 of the synthetic resin film sheet 31 is broken when subjected to stretching. For this reason, in the part 39 which received the stretch of the synthetic resin film sheet 31, the recessed part 33 of the synthetic resin film sheet 31 is torn, the torn part of the synthetic resin film sheet 31 spreads, and an opening part is formed.

  The synthetic resin film sheet 31 is not stretched so much at the portions 40 and 41 where the gear teeth 37a of the upper roll 37 and the gear teeth 38a of the lower roll 38 are not engaged with each other. For this reason, even if the synthetic resin film sheet 31 passes through the stretched gear roll 36 in the portions 40, 41 where the gear teeth 37a of the upper roll 37 and the gear teeth 38a of the lower roll 38 are not engaged in the synthetic resin film sheet 31, The concave portion 33 formed in the above-described concave portion forming step is not torn and does not become an opening portion.

  In the region where the concave portion 33 of the synthetic resin film sheet 31 is not formed, even if the synthetic resin film sheet 31 is greatly stretched at the portion 39 where the gear teeth 37a of the upper roll 37 and the gear teeth 38a of the lower roll 38 are engaged with each other. Since the synthetic resin film sheet 31 is not torn, no opening is formed.

[Other examples]
The concave groove 22 can be arranged in various forms. As shown in FIG. 1, the concave groove 22 is preferably formed in the middle of the longitudinal direction in the center portion in the pad width direction corresponding to the urine discharge site H, but only one line is formed in FIG. As shown in A) and (B), a plurality of strips may be formed spaced apart in the pad width direction, or as shown in FIG. You may form in a shape. 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 a plurality of strips are formed apart in the pad width direction, the even strips shown in FIG. 16A or the odd strips shown in FIG. 16B may be used.

  Further, the planar shape of the concave groove 22 may be formed with an equal width along the longitudinal direction of the pad as shown in FIG. 1, or may be formed with different groove widths as shown in FIG. Also good. In FIG. 17A, a widened portion 22a having 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. 17B, or may be provided at the front and rear end portions as shown in FIG. 17C.

  The concave groove 22 may be provided with one or a plurality of branch portions 22b and 22c as shown in FIG. 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. 18A to 18C, 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, 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. 18D to 18F, 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, it is preferable to provide the absorber recessed part 20 along the shape of the said recessed groove 22.

  Further, as shown in FIG. 19, one or more longitudinal grooves 20a are provided as the absorbent body recess 20 along the longitudinal direction of the pad, and one or more branches are formed on one side or both sides of the longitudinal groove 20a. The liquid-permeable surface sheet 3 is disposed along the absorber recess 20 only by the longitudinal groove 20a, and the liquid-permeable surface sheet 3 is absorbed by the branching portion 20b of the absorber recess 20 You may arrange | position in the state which provided the space part between the absorber of the branch part 20b, and the liquid-permeable surface sheet 3, without arrange | positioning along 20. This makes it easier for urine to diffuse on the lower layer side of the liquid-permeable surface sheet 3 along the branching portion 20b of the absorbent body recess 20, so that urine can be absorbed and retained in a wider range of the absorbent body 4 and leakage is prevented. it can. The branching portion 20b is provided so as to extend from the longitudinal groove 20a to both sides in the width direction so as to extend to an intermediate position in the width direction with an interval in the pad longitudinal direction. The intervals between the branching portions 20b and 20b adjacent in the pad longitudinal direction may be equal in each portion, but as shown in FIG. 19, the urine discharge site H and the vicinity thereof are narrower than the front and back regions. It is preferable to arrange in the above.

  Further, as shown in FIG. 20, the concave groove 22 is composed of a linear portion 22d extending along the pad longitudinal direction and arcuate curved portions 22e extending on both sides of the linear portion 22d, and has an end portion. It can also be formed in a loop shape. Thereby, it can prevent that a leak arises from the edge part of the ditch | groove 22, urine tends to stay in a ditch | groove, and becomes easy to be absorbed by the absorber 4. FIG.

  In the above embodiment, the absorber recess 20 is formed in the shape of a groove with a bottom as shown in FIG. 2, but as shown in FIG. 21, a slit that penetrates from the front side to the back side. You may form in a shape. When the absorber recess 20 is slit-shaped, the embossed portion 21 has a liquid-impermeable back sheet 2 that penetrates the absorber recess 20 disposed on the bottom surface of the absorber recess 20 as shown in FIG. To be applied to. Even when the absorber recess 20 is formed in a slit shape and the absorber 4 is not interposed at the bottom of the groove 22, urine is absorbed through the liquid-permeable surface sheet 3 interposed at the bottom of the groove 22. Since the urine absorbed in the liquid-permeable surface sheet 3 on the bottom surface of the groove is diffused along the groove 22, a decrease in absorption performance is suppressed to a slight extent.

  DESCRIPTION OF SYMBOLS 1 ... Incontinence pad, 2 ... Liquid impervious 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, 15 ... opening, 16 ... crease, 17 ... bellows part, 18 ... shape holding part, 20 ... absorber recess, 21 ... embossing part, 22 ... recess groove

Claims (4)

An absorbent body is interposed between the liquid-permeable top sheet and the back sheet, a groove is formed along the longitudinal direction on the skin side, and the liquid-permeable surface sheet is disposed along the groove. In absorbent articles,
The concave groove is a concave groove for inflow of urine that is formed in the middle portion in the longitudinal direction in the center in the width direction corresponding to the urine excretion site,
The liquid-permeable surface sheet is made of a resin film in which a large number of apertures are formed, and is folded in a plurality along a fold extending in the longitudinal direction of the absorbent article in at least a width range including the concave groove. A bellows portion is formed, and a large number of holes are formed in the side surface portion connecting the mountain fold portion and the valley fold portion of the bellows portion, so that the holes existing per unit area in the concave groove are formed. The total area is increased ,
Within the concave groove, the liquid-permeable topsheet is bonded to the bottom of the concave groove by hot melt adhesive or a plurality of pin-shaped or dot-shaped embosses, and the wave-shaped portion of the bellows is maintained while maintaining the wave shape. The absorbent article , wherein the liquid surface sheet is disposed along the concave groove, whereby the bellows portion is disposed along a bottom surface and both side surfaces of the concave groove .   The total area of the apertures existing per unit area is 1.2 times to 5 times the total area of the apertures existing per unit area when the liquid-permeable surface sheet is arranged in a plane. The absorbent article according to claim 1, which is doubled. Wherein for holding the bellows of the bellows portion, the absorbent article according to claim 1, 2 or the shape holding portion connecting the folds adjacent the bellows portion is formed. The absorptive article according to claim 3 in which said shape maintenance part is formed in mesh shape.

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