JP7351689B2 - absorbent articles - Google Patents

Description

The present invention relates to an absorbent article used for incontinence pads, panty liners, sanitary napkins, etc. More specifically, the top sheet forming the skin contact surface is made of cellulose fibers, and the absorbent article is made of cellulose fibers and The present invention relates to an absorbent article in which slits are formed in corresponding regions.

Conventionally, absorbent articles such as incontinence pads, panty liners, and sanitary napkins have been made of paper cotton such as pulverized pulp between a liquid-impermeable back sheet such as a polyethylene sheet or polyethylene sheet laminate nonwoven fabric and a top sheet. Types with an absorber interposed are known.

Since the topsheet forms the skin-contact surface, it is required to be flexible, provide a dry feel even after absorbing excretory fluid, and be less irritating to the skin. As materials that meet these requirements, synthetic fiber nonwoven fabrics and resin mesh sheets are widely used in the field of absorbent articles. However, the surface sheet made of a nonwoven fabric made of synthetic fibers was not fully satisfactory in that it easily caused itching and rashes.

To solve this problem, a surface sheet made of cotton fibers has been proposed. A top sheet made of cotton fibers has the advantage of providing a soft feel similar to underwear, but in absorbent articles, the top sheet has high liquid permeability and allows liquid to quickly transfer to the absorbent body. However, when ordinary absorbent cotton fibers are contained in the top sheet, there is a problem that the top sheet itself has high liquid retention properties and tends to leave a sticky feeling on the surface.

As a technique for preventing such a sticky feeling due to liquid residue on the top sheet, Patent Document 1 below discloses that the top sheet is composed of two liquid-permeable nonwoven fabric sheets, and the uppermost nonwoven fabric sheet on the body side is Linear slits penetrating the nonwoven fabric sheet are intermittently provided along the longitudinal direction of the absorbent article, and the nonwoven fabric sheet is disposed in the lower layer along the width direction of the absorbent article. An absorbent article is disclosed in which penetrating linear slits are provided intermittently, and the slits provided in each of the vertically laminated nonwoven fabric sheets do not overlap in the vertical direction.

Further, Patent Document 2 listed below discloses an absorbent article in which the topsheet has a plurality of convex portions having internal cavities, and the convex portions have slits passing through the top portions.

JP2017-209306A Japanese Patent Application Publication No. 2005-124854

In a normal top sheet, the fibers are oriented along the longitudinal direction of the absorbent article, but in the absorbent article described in Patent Document 1, the slits provided in the nonwoven fabric sheet of the uppermost layer on the body side are aligned with the fiber orientation. Because they extend in parallel directions, body fluids that diffuse along the fiber orientation are difficult to migrate to the lower layer side through the slits, and the diffusion area of body fluids on the surface becomes large, which tends to cause a sticky feeling on the surface.

Further, in the absorbent article described in Patent Document 2, a slit is provided at the top of the convex portion having an internal cavity, so body fluids that diffuse along the top of the convex portion are easily transferred to the lower layer side. However, body fluids that diffuse along the recesses are difficult to migrate to the lower layer, and the surface tends to feel sticky.

Therefore, the main object of the present invention is to create an absorbent article that uses cellulose fibers as the fibers constituting the skin-contact surface layer, which facilitates the transfer of body fluids to the lower layer and reduces the sticky feeling on the surface. It is about providing.

In order to solve the above problems, in a first aspect, the top sheet forming the skin contact surface has a non-woven fabric layer made of cellulose fibers on the skin side and a non-woven fabric layer made of synthetic fibers on the non-skin side. A single-layer structure of a nonwoven fabric made of cellulose fibers, or a nonwoven fabric layer made of cellulose fibers on the skin side and a nonwoven fabric layer made of synthetic fibers on the non-skin side, combined by intertwining of the fibers. A second sheet made of synthetic fiber is placed on the non-skin side of the top sheet, which has a two-layer structure.
The nonwoven fabric made of cellulose fibers is composed of a spunlace nonwoven fabric,
The fibers of the nonwoven fabric made of cellulose fibers are oriented along the longitudinal direction of the absorbent article,
In a region of the top sheet corresponding to a body fluid discharge part of the wearer, slits are provided at intervals in the longitudinal direction, and extend through the top sheet and cross the longitudinal center line of the absorbent article in the width direction. Multiple formations ,
An absorbent article characterized in that the non-skin side nonwoven fabric layer or the second sheet is formed with a fused portion that partially fuses the synthetic fibers on both sides of the slit so as to straddle the slit. is provided.

In the first aspect, the top sheet forming the skin-contacting surface is composed of a non-woven fabric layer made of cellulose fibers on the skin side and a non-woven fabric layer made of synthetic fibers on the non-skin side, which are combined by intertwining of the fibers. A single-layer structure of a non-woven fabric made of cellulose fibers or a two-layer structure in which a non-woven fabric layer made of cellulose fibers on the skin side and a non-woven fabric layer made of synthetic fibers on the non-skin side are combined by fiber entanglement. In an absorbent article in which a second sheet made of synthetic fiber is disposed on the non-skin side of a top sheet , the top sheet is penetrated into an area corresponding to the wearer's body fluid discharge area, and the second sheet is made of synthetic fiber. A plurality of slits that extend continuously across the longitudinal center line of the absorbent article in the width direction are formed at intervals in the longitudinal direction, so that the fibers are usually oriented along the longitudinal direction of the absorbent article. In the top sheet, body fluids that diffuse along the fiber orientation easily enter the slits extending in the width direction of the absorbent article, which is substantially perpendicular to the fiber orientation, and the body fluids easily migrate to the lower layer side through these slits. As a result, body fluids are less likely to remain on the surface, reducing the sticky feeling on the surface.

In the first aspect, the top sheet may have a single layer structure of a nonwoven fabric made of cellulose fibers, or a nonwoven fabric layer made of cellulose fibers on the skin side and a nonwoven fabric layer made of synthetic fibers on the non-skin side. A two-layer structure in which the fibers are joined by intertwining the fibers is used. In any case, since the skin-contacting surface is made of cellulose fibers, it feels soft to the touch. In addition, in the case of a two-layer structure, the non-woven fabric layer made of synthetic fibers bonded to the non-skin side makes tearing at the slit ends less likely to occur compared to a case made only of cellulose fibers.

In the first aspect, the fibers of the nonwoven fabric made of cellulose fibers are oriented along the longitudinal direction of the absorbent article, and the slits extend in the width direction of the absorbent article perpendicular to the fiber orientation, so that the fibers are oriented along the longitudinal direction of the absorbent article. Body fluids that diffuse along the oriented direction tend to enter the slits.

In the first aspect, a layer made of synthetic fiber is provided on the non-skin side of a layer made of cellulose fiber on the skin contacting side, and the layer made of synthetic fiber is provided so as to straddle the slit. Since the synthetic fibers form the fused portion, the layer made of cellulose fibers on the skin-contacting surface side of the slit portion can be prevented from peeling or brittle, and deterioration of the wearing feeling can be suppressed.

In a second aspect, an absorbent article is provided in which the length of the slit is 10 to 60 mm.

In the second aspect described above, if the length of the slit is too short, body fluids tend to go around both ends of the slit and diffuse to the outside, and if the length of the slit is too long, the top sheet may turn over, worsening the fit and causing the body fluid to return. This tends to occur, so the length of the slit is set to a predetermined length.

As a third aspect, a second sheet made of synthetic fiber is disposed on the non-skin side of the top sheet, and the slit is formed to penetrate the top sheet and the second sheet . An absorbent article according to the present invention is provided.

In the third aspect, a top sheet made of cellulose fibers and a second sheet made of synthetic fibers are laminated, and the slits are formed in these top sheets and second sheets. By arranging the second sheet made of synthetic fibers on the non-skin side of the topsheet, tearing at the slit ends becomes less likely to occur compared to a sheet made only of cellulose fibers.

As a fourth aspect, there is provided the absorbent article according to any one of claims 1 to 3 , wherein a burr protruding toward the non-skin side is formed on the periphery of the slit.

In the fourth aspect, the slits are formed by cutting the topsheet from the skin-contacting side toward the non-skin side with a cutter. It is made to protrude to the side. Therefore, body fluids tend to migrate to the non-skin side along this burr.

As a fifth aspect, the absorbent material according to any one of claims 1 to 4 , wherein the planar shape of the slit is a straight line or a curved line that bulges outward with respect to the center of the region corresponding to the wearer's body fluid discharge part. Goods are provided.

In the fifth aspect, the planar shape of the slit is a straight line or a concave curved line toward the center of the body fluid discharge section. In particular, when the latter curve is formed, the body fluid accumulated in the concave portion of the curve easily enters the slit and transfers to the non-skin side, and the amount of body fluid that goes around both ends of the slit and diffuses to the outside is reduced.

As described in detail above, according to the present invention, in an absorbent article using cellulose fibers as the fibers constituting the skin-contact surface layer, body fluids can easily migrate to the lower layer side, and the sticky feeling on the surface can be reduced. Become.

1 is a partially cutaway developed view of a light incontinence pad 1 according to the present invention. 2 is a view taken along the line II-II in FIG. 1. FIG. 2 is a view taken along the line III-III in FIG. 1. FIG. FIG. 3 is a cross-sectional view of the top sheet 3. FIG. FIG. 3 is an enlarged plan view of the top sheet 3. FIG. 3 is a perspective view of a slit 20. FIG. 7 is a view taken along the line VII-VII in FIG. 6. FIG. FIG. 3 is a plan view of a light incontinence pad 1 according to a modified example. FIG. 3 is a plan view of a light incontinence pad 1 according to a modified example. FIG. 3 is a plan view of a light incontinence pad 1 according to a modified example. FIG. 3 is a plan view of a light incontinence pad 1 according to a modified example. 3 is a perspective view of a slit 20. FIG. 13 is a view taken along the line XIII-XIII in FIG. 12. FIG. FIG. 3 is a plan view of a light incontinence pad 1 according to a modified example. FIG. 7 is an enlarged plan view of a slit 20 according to a modified example.

Embodiments of the present invention will be described in detail below with reference to the drawings.

<An example of the basic structure of light incontinence pad 1>
As shown in FIGS. 1 to 3, the light incontinence pad 1 according to the present invention has a liquid-impermeable back sheet 2 made of a polyethylene sheet, etc., and a skin-contacting surface, and quickly removes body fluids such as urine. A liquid-permeable surface sheet 3 for permeation, an absorbent body 4 made of cotton-like pulp or synthetic pulp interposed between these two sheets 2 and 3, and a material for retaining the shape of the absorbent body 4 and improving its diffusivity. An enveloping sheet 5 made of crepe paper or non-woven fabric that covers at least the skin side and non-skin side of the absorbent body 4, and a second sheet 6 interposed between the top sheet 3 and the absorbent body 4 as necessary. and a pair of left and right parts that have substantially the side edges of the absorbent body 4 as their upright base ends, and that are provided so as to protrude toward the skin within a predetermined section in the front-rear direction that includes at least a region corresponding to the wearer's body fluid discharge part H. It is mainly composed of three-dimensional gathers BS, and side nonwoven fabrics 7, 7 forming the BS, and around the absorber 4, the outer edges of the back sheet 2 and top sheet 3 are hot at the upper and lower edges thereof. The back sheet 2 and the side nonwoven fabric 7, which are joined by a joining means such as an adhesive such as melt, heat sealing, or ultrasonic sealing, and which extend laterally beyond the absorber 4 at both side edges thereof, are hot melted. They are bonded using bonding means such as adhesives, heat seals, and ultrasonic seals. In the illustrated example, the absorbent body 4 has a one-layer structure, but it may have a multi-layer structure forming a middle portion, or a multi-layer structure in which absorbers of the same size and shape are stacked.

The back sheet 2 is made of a sheet material such as polyethylene that has at least a water-blocking property, but in recent years there has been a tendency to use a sheet material that has moisture permeability from the viewpoint of preventing stuffiness. This water-blocking and moisture-permeable sheet material is made by melt-kneading an inorganic filler into an olefin resin such as polyethylene or polypropylene, forming a sheet, and then stretching the sheet in a uniaxial or biaxial direction. A sheet is preferably used. One or more adhesive layers (not shown) are formed on the underwear contacting surface (outer surface) of the back sheet 2, so that the light incontinence pad 1 is fixed to the underwear when worn on the body. As the back sheet 2, a polylaminated nonwoven fabric made by laminating a plastic film and a nonwoven fabric may be used.

The absorbent body 4 is capable of absorbing and retaining body fluids, and is made of fluff-like pulp fibers mixed with powder-like super absorbent polymer dispersed therein, or an upper layer sheet placed on the skin side and a non-skin-like material. It is possible to use a polymer sheet in which a superabsorbent polymer is interposed in a predetermined region between the lower sheet and the lower sheet disposed on the side.

Examples of the pulp fibers include cellulose fibers such as chemical pulp and dissolving pulp obtained from wood, and artificial cellulose fibers such as rayon and acetate. Softwood pulp, which has a longer fiber length, is more functional than hardwood pulp. and is suitable for use in terms of price. The pulp fiber has a basis weight of 150 to 500 g/m ² , preferably 250 to 400 g/m ² , and the superabsorbent polymer has a basis weight of 70 to 470 g/m ² , preferably 140 to 240 g/m 2 . It is better to set it to ^m2 .

Examples of the superabsorbent polymer include crosslinked polyacrylates, self-crosslinked polyacrylates, saponified crosslinked acrylic ester-vinyl acetate copolymers, crosslinked isobutylene/maleic anhydride copolymers, Examples include crosslinked polysulfonate salts and partially crosslinked water-swellable polymers such as polyethylene oxide and polyacrylamide. Among these, acrylic acid or acrylate-based materials are preferred because of their excellent water absorption amount and water absorption rate. The absorption capacity (water absorption power) and absorption rate of the superabsorbent polymer having water absorption performance can be adjusted by adjusting the crosslink density and the crosslink density gradient during the manufacturing process.

In the illustrated example, the topsheet 3 is slightly wider than the width of the absorbent core 4 and only covers the absorbent core 4, and the outside of the topsheet 3 in the width direction extends from the surfaces of both sides of the topsheet 3. It is covered with the existing side nonwoven fabric 7 (a member different from the topsheet 3). A portion of the side nonwoven fabric 7 on the center side in the width direction forms a three-dimensional gather BS. As the side nonwoven fabric 7, a nonwoven fabric material that has been subjected to an appropriate water repellent treatment or hydrophilic treatment can be used depending on the purpose of preventing body fluids from permeating or enhancing the texture. The side nonwoven fabric 7 may be made of natural fibers, synthetic fibers, recycled fibers, or the like and formed by an appropriate processing method, but it is preferable to eliminate stiffness and prevent stuffiness. Therefore, it is best to use a nonwoven fabric with a low basis weight and breathability. Specifically, it is desirable to use a nonwoven fabric with a basis weight of 15 to 23 g/ ^m2 , and coat it with a water repellent such as silicone or paraffin to reliably prevent the permeation of body fluids. A water-repellent treated nonwoven fabric is preferably used.

As shown in FIGS. 2 and 3, the side nonwoven fabric 7 extends from the middle part in the width direction to the outer edge of the backsheet 2 from the inner side of the absorbent body 4 to the outer edge of the backsheet 2, slightly beyond the side edge of the absorbent body. It is attached using adhesive such as hot melt.

On the other hand, the inner side portion of the side nonwoven fabric 7 is folded back almost double, and one or more fibers are fixed at both ends or at appropriate positions in the longitudinal direction inside the double sheet. In the illustrated example, the two elastic stretchable members 8, 8 of the book are arranged with both ends or appropriate positions in the longitudinal direction fixed, so that the contractile force of the elastic stretchable members 8, 8 is applied to the skin side. A three-dimensional gather BS standing upright is formed. The front and rear ends of this double sheet portion are fixed to the topsheet 3 side in a folded state, as shown in FIG.

<Surface sheet>
The topsheet 3 forms the skin-contacting surface of the incontinence pad 1 that covers the skin side of the absorbent body 4, and at least the skin-contacting surface layer is made of a nonwoven fabric made of cellulose fibers. The top sheet 3 may have a single layer structure of a nonwoven fabric made of cellulose fibers, as shown in FIG. The non-woven fabric layer 3a and the non-skin side non-woven fabric layer 3b made of synthetic fibers may have a two-layer structure, which are combined by intertwining of fibers. In any case, the skin-contacting surface of the topsheet 3 is made of hydrophilic cellulose fibers.

Examples of the hydrophilic cellulose fibers include naturally derived fibers such as cotton fibers and pulp fibers, and artificial cellulose fibers such as rayon fibers, acetate fibers, and lyocell fibers. The cotton fibers include raw cotton, cotton fibers that have been refined and bleached, cotton fibers that have been refined and bleached and then dyed, cotton fibers that have been refined and bleached, and fibers that have been defibrated into yarn or fabric. Any type of cotton fiber, such as hair, can be used, but in order to increase the absorption speed and dispersion of liquid in the lower sheet, absorbent cotton fibers that have been degreased from the natural oils and fats of the cotton wax adhering to the surface of the cotton fibers are used. is preferable.

The aforementioned nonwoven fabric made of cellulose fibers is particularly preferably composed of a spunlace nonwoven fabric made of 100% by weight cotton fibers. By being composed only of cotton fibers, it feels soft to the touch and is less likely to cause skin problems such as itching or rashes even when worn for a long time. In addition, spunlace nonwoven fabrics have advantages such as not using adhesives and having flexibility.

The basis weight of the nonwoven fabric made of cellulose fibers is preferably 10 to 30 g/m ² , preferably 15 to 20 g/m ² so as to exhibit the flexibility and texture of cellulose fibers. The basis weight of the nonwoven fabric was determined by cutting out a sample with dimensions of 50 mm x 50 mm (±2 mm), measuring the weight, and converting the weight to the weight per 1 m ² .

For the non-woven fabric layer 3b made of synthetic fibers on the non-skin side, a perforated or non-porous non-woven fabric is used. The nonwoven fiber material contains heat-fusible fibers. Examples of the heat-fusible fibers include single thermoplastic synthetic fibers such as olefins such as polyethylene or polypropylene, polyesters, and polyamides, as well as recycled fibers such as rayon and cupro, cotton, etc. Natural fibers such as these can be included, and composite fibers having a core-sheath structure containing these synthetic fibers can also be used. By providing the non-woven fabric layer 3b made of synthetic fibers on the non-skin side of the non-woven fabric layer 3a made of cellulose fibers, bondability can be improved by thermal melting of the heat-fusible fibers, and the non-woven fabric layer 3b made of synthetic fibers can be improved. It is difficult to retain liquid, and the permeability of liquid to the lower layer side is improved, and it is possible to suppress the phenomenon that body fluids are retained in the nonwoven fabric layer 3b made of synthetic fibers and return to the skin side.

In order to facilitate the transfer of body fluids from the non-woven fabric layer 3a made of cellulose fibers on the skin side to the non-woven fabric layer 3b made of synthetic fibers on the non-skin side, a hydrophilic agent may be externally applied to the non-woven fabric layer 3b made of synthetic fibers. . Application of the hydrophilic agent to the nonwoven fabric layer 3b made of synthetic fibers prevents the hydrophilic agent from running off during hydroentangling when the nonwoven fabric layer 3a on the skin side and the nonwoven fabric layer 3b on the non-skin side are joined by hydroentanglement. Therefore, after these are joined by hydroentanglement, it is preferable to apply it to the outer surface of the nonwoven fabric layer 3b made of synthetic fibers. However, when the joining of both nonwoven fabric layers 3a and 3b is by puncturing with a needle, the nonwoven fabric layer 3a on the skin side It may be done before or after joining with.

The nonwoven fabric layer 3b made of synthetic fibers can also be configured not to contain non-thermal fusible fibers, specifically the above-mentioned cellulose fibers, and may be made of non-thermal fusible fibers, specifically synthetic fibers. It may be composed only of fibers.

The basis weight of the non-woven fabric layer 3b made of synthetic fibers on the non-skin side is preferably smaller than that of the non-woven fabric layer 3a made of cellulose fibers on the skin side, specifically 8 to 25 g/m ² , preferably 13 to 25 g/m 2 . It is preferable to set it to 20g/ ^m2 . By making the non-woven fabric layer 3a made of cellulose fibers on the skin side larger than the basis weight of the non-woven fabric layer 3b made of synthetic fibers on the non-skin side, the synthetic fibers are less likely to jump out onto the non-woven fabric layer 3a made of cellulose fibers, resulting in a good texture. becomes.

It is desirable that the skin-side non-woven fabric layer 3a made of cellulose fibers and the non-skin-side non-woven fabric layer 3b made of synthetic fibers be joined by a predetermined joining method. If the layers 3a and 3b were simply laminated without being bonded together, the strength of the nonwoven fabric layer 3a made of cellulose fibers would be weak and it would be easily torn, which is not preferable. That is, by joining the nonwoven fabric layers 3a and 3b, the nonwoven fabric layer 3a made of cellulose fibers on the skin side is reinforced by the nonwoven fabric layer 3b made of synthetic fibers on the non-skin side, and tearing of the topsheet 3 can be prevented. preferable. In addition, when the surface sheet has the same basis weight, it is more expensive than synthetic fibers because it has a two-layer structure of non-woven fabric layers 3a and 3b, compared to a one-layer structure consisting only of non-woven fabric made of cellulose fibers. It is preferable to have a two-layer structure in which the nonwoven fabric layers 3a and 3b are bonded, since the amount of cellulose fibers used can be reduced, and the cost of the topsheet 3 can be suppressed.

The nonwoven fabric layer 3a made of cellulose fibers on the skin side and the nonwoven fabric layer 3b made of synthetic fibers on the non-skin side are preferably joined by intertwining their fibers, rather than using an adhesive or the like. By intertwining these fibers with each other and joining them, there is no material such as adhesive interposed between these nonwoven fabric layers 3a and 3b that tends to inhibit the transfer of body fluids, compared to the case where they are joined with an adhesive or the like. Body fluids are easily transferred from the non-woven fabric layer 3a on the skin side to the non-woven fabric layer 3b on the non-skin side, and body fluids are also easily transferred from the non-woven fabric layer 3a on the skin side to the non-woven fabric layer 3b on the non-skin side through the intertwined fibers. In addition, since the joining strength is not so strong when the fibers are intertwined, when the nonwoven fabric layer 3b made of synthetic fibers is heated and squeezed, the effect of heating and squeezing on the nonwoven fabric layer 3a made of cellulose fibers is reduced. It also has the advantage of Examples of joining methods by intertwining fibers include a water jet entanglement method in which the fibers are entangled with each other by jetting a high-pressure water jet, and a piercing method in which the fibers are mechanically entangled with each other by piercing with a needle.

By bonding the non-woven fabric layer 3b made of synthetic fibers to the non-skin side of the non-woven fabric layer 3a made of cellulose fibers by intertwining the fibers, the non-woven fabric layer made of cellulose fibers can be formed even if slits 20, which will be described in detail later, are formed. 3a becomes difficult to tear.

By the way, as shown in FIG. 5, the nonwoven fabric made of cellulose fibers of the top sheet 3 has a large number of openings 12 penetrating the front and back, at least in the area corresponding to the body fluid discharge part H, in order to improve liquid permeability. It is preferable to provide 12.... Specifically, the openings 12 can be formed by supporting the fibrous material on a mesh support during the hydroentangling process during spunlace production. In this case, by changing the conditions of the mesh used, it is possible to adjust the individual aperture size and aperture ratio. Of course, the holes may be formed by punching the nonwoven fabric after production. The openings 12 may be provided in the entire surface sheet, but are preferably provided at least in the region corresponding to the body fluid discharge section H. Preferably, it includes a region corresponding to the body fluid discharge part H, and corresponds to 15% or more of the length of the absorbent body in the product length direction, and 50% or more of the absorbent body width in the product width direction, and more preferably corresponds to the body fluid discharge part H. It is provided in an area that is 50% or more of the length of the absorbent body in the product length direction and 70% or more of the absorbent body width in the product width direction. If the area in which the openings 12 are formed is less than 15% of the absorber length in the product length direction and less than 50% of the absorber width in the product width direction, there is a possibility that the body fluid drainage range cannot be covered. This occurs, and body fluids remain on the top sheet 3, making it feel sticky and causing skin problems such as itching and rashes when worn. The apertures 12 may be provided only in the nonwoven fabric made of cellulose fibers, or the topsheet 3 may be formed between a nonwoven fabric layer 3a made of cellulose fibers on the skin side and a nonwoven fabric layer 3b made of synthetic fibers on the non-skin side. When it has a layered structure, it may be provided on both the nonwoven fabric layers 3a and 3b.

As shown in FIG. 5, the opening 12 is formed in a vertically elongated shape extending in the longitudinal direction of the light incontinence pad 1. For this reason, liquid can permeate through the top sheet 3 more easily than through the circular holes, so body fluids can easily pass through the top sheet 3 through the holes 12, and water retention in the top sheet 3 is reduced. Furthermore, when the body fluid passes through the openings 12, the fluid passes through while being deformed vertically, so the direction of diffusion of the body fluid can be controlled in the longitudinal direction of the napkin, and diffusion in the lateral direction is suppressed, making side leakage difficult. In the case of spunlace, the shape of the hole is difficult to be uniform, but the shape of the hole 12 is approximately rectangular to a long hole with rounded corners or an ellipse.

As for the dimensions of the opening 12, the length L1 in the longitudinal direction of the light incontinence pad 1 is preferably 0.5 to 4.0 mm, preferably 1.0 to 3.0 mm. The length L2 in the width direction is preferably 0.5 to 1.5 mm, preferably 0.5 to 1.0 mm. If the dimension of the aperture 12 is less than 0.5 mm, it is difficult for body fluids to pass through, and it is difficult to form a clear aperture due to the fluff of the fibers. This causes the material that makes up the absorber 4 to become exposed on the surface. Further, the ratio between L1 and L2 (L1/L2) is preferably 1.2 to 5.0, preferably 2.0 to 3.0. The area A of the opening 12 is preferably 0.3 to 3.0 mm ² , preferably 0.4 to 2.5 mm ² . Further, the porosity is preferably 15 to 45%, preferably 17 to 30%, and more preferably 18 to 25%. The dimensions of the openings 12 do not need to be uniform throughout, and can be formed to any size within the above range.

As shown in FIG. 5, the nonwoven fabric made of cellulose fibers of the top sheet 3 is made of cotton fibers, and extends along the longitudinal direction of the light incontinence pad 1, and is formed at intervals in the width direction. Vertical stripes 13, 13... and a large number of horizontal stripes 14, 14... extending along the width direction of the light incontinence pad 1 and connecting adjacent longitudinal strips 13, 13 formed at intervals in the longitudinal direction. It is preferable to have a structure in which the openings 12 are formed in a portion surrounded by the vertical stripes 13 and the horizontal stripes 14.

The width W1 of the vertical stripes 13 is preferably 0.3 to 2.5 mm, preferably 0.4 to 2.3 mm, and the width W2 of the horizontal strips 14 is preferably 0.1 to 1.6 mm. It is preferable to set it to 0.1 to 1.4 mm. Further, the ratio of the widths W1 and W2 (W1/W2) is preferably 1.2 to 3.0, preferably 1.5 to 2.0. By making the width W1 of the vertical stripes 13 larger than the width W2 of the horizontal stripes 14, liquid diffusion in the longitudinal direction of the light incontinence pad 1 along the longitudinal stripes 13 is likely to occur.

The vertical stripes 13 have a larger amount of fibers than the horizontal strips 14, and are formed at a higher density. As a result, only the vertical stripes 13 come into contact with the skin, and by reducing the contact area with the skin, skin problems such as itching and rashes are less likely to occur even when worn for a long time, and at the same time, it is possible to eliminate Even after applying the liquid, the sticky feeling is reduced. Further, when body fluid passes through the topsheet 3, it tends to diffuse in the longitudinal direction of the light incontinence pad 1 along the relatively high-density longitudinal stripes 13 due to the capillary action of the fibers. Furthermore, since the diffusion directions of the body fluid passing through the apertures 12 and the body fluid permeating the topsheet 3 are the same in the longitudinal direction of the light incontinence pad 1, the topsheet is drawn in by the body fluid passing through the apertures 13. Since the liquid permeates through the vertical stripes 13 of No. 3, the amount of liquid remaining on the top sheet 3 is suppressed as much as possible.

The amount of fiber can be measured according to the "Pulp-sieving test method" of JIS P8207:2009. In addition, the density was measured by automatically measuring the thickness T ₀ (load: 0.5 gf/cm ² ) using an automatic thickness measuring device (handy compression testing machine manufactured by Kato Tech Co., Ltd., KES-G5). It can be calculated from T ₀ .

It is preferable that a water repellent agent is externally applied to at least a region corresponding to the body fluid discharge portion H on the nonwoven fabric made of cellulose fibers of the top sheet 3. As the water repellent, one which is less irritating to the skin can be appropriately selected from among known ones such as paraffin-based and silicon-based ones.

Application of the water repellent to the nonwoven fabric made of cellulose fibers is carried out in such a way that the top sheet 3 has a two-layer structure of a nonwoven fabric layer 3a made of cellulose fibers on the skin side and a nonwoven fabric layer 3b made of synthetic fibers on the non-skin side. In this case, when the nonwoven fabric layers 3a and 3b are joined by hydroentangling, in order to prevent the water repellent from flowing down during hydroentangling, the nonwoven fabric layer 3a on the skin side is It is preferable to apply it to the outer surface, but if the nonwoven fabric layers 3a and 3b are joined by needle pricking, it may be applied either before or after the nonwoven fabric layer 3b on the non-skin side is joined.

Even if the water repellent is applied only to the skin-contacting surface of the skin-contacting surface and the non-skin-contacting surface (the surface on the absorbent body 4 side) of the nonwoven fabric made of cellulose fibers, It may be applied to both the surface of the absorbent body 4, but it is recommended that the water absorption amount determined from the water absorption test described below be at least 0.03 g or less, preferably 0.02 g or less. preferable.

The water absorption amount of the top sheet 3 was determined by the following procedure. (1) Prepare a 10 cm square sample and measure its weight (A). (2) Stack three 10 cm square filter papers with the smooth surface facing up, and set the sample on top of them. (3) Drop 3 ml of room temperature tap water onto the set sample and leave it for 5 minutes. (4) Measure the weight of the sample after standing for 5 minutes (B). (5) Determine the water absorption amount (water retention amount) of the top sheet 3 from (B) - (A) = water absorption amount (g).

As a method for applying the water repellent, known methods such as transfer, spraying, brushing, impregnation, and dipping can be used as appropriate. When the water absorption on both sides of the sheet is made to differ, a transfer coating method can be preferably used.

From the viewpoint of manufacturing efficiency, it is preferable to apply the water repellent to the entire surface, but it suffices if the water repellent is applied to at least the area corresponding to the body fluid discharge part H, and may be applied only to the area that receives the excretory fluid.
<Second seat>
The second sheet 6, which is provided as necessary, is placed between the topsheet 3 and the absorbent core 4 and adjacent to the non-skin side of the topsheet 3. That is, the non-skin side surface of the top sheet 3 and the skin side surface of the second sheet 6 are disposed to face each other. Preferably, these are joined by an adhesive applied in an intermittent application pattern. It is preferable that the second sheet 6 has substantially the same planar shape as the top sheet 3.

The second sheet 6 is made of perforated or non-perforated nonwoven fabric. The fiber material of the nonwoven fabric contains synthetic fibers. For example, in addition to thermoplastic synthetic fibers such as olefins such as polyethylene or polypropylene, polyesters, and polyamides, these synthetic fibers may include recycled fibers such as rayon and cupro, and natural fibers such as cotton. As the nonwoven fabric, a nonwoven fabric obtained by an appropriate processing method such as a spunlace method, a spunbond method, a thermal bond method, a melt blown method, a needle punch method, etc. can be used.

The second sheet 6 is preferably formed to have a lower basis weight and density than the top sheet 3. As a result, some of the fibers of the topsheet 3 enter between the fibers of the second sheet 6, making it easier for bodily fluids to transfer from the topsheet 3 to the second sheet 6. The basis weight of the second sheet 6 is preferably 13 to 35 g/m ² , preferably 13 to 18 g/m ² .

It is preferable that the second sheet 6 uses a material fiber that is hydrophilic to body fluids. Specifically, synthetic fibers that are surface-treated with a hydrophilic agent to impart hydrophilic properties can be used. It is preferable that the second sheet 6 has higher hydrophilicity than the top sheet 3.

<Slit>
In this light incontinence pad 1, a region of the top sheet 3 corresponding to the wearer's body fluid discharge part H is penetrated through the front and back of the top sheet 3, and the longitudinal center line CL of the light incontinence pad 1 is aligned in the width direction. A plurality of slits 20, 20... extending across are formed at intervals in the longitudinal direction. The slit 20 extends across the left side region and the right side region with the longitudinal center line CL of the light incontinence pad 1 as a border, and is formed along the width direction at the center of the light incontinence pad 1 in the width direction. . In order to provide the slits 20 in the top sheet 3, the top sheet 3 in which slits have been previously provided may be used, or the slits 20 may be provided by cutting with a cutter during the manufacturing process of the light incontinence pad 1.

By forming the slits 20, normally, in the top sheet 3 in which the fibers are oriented along the longitudinal direction of the light incontinence pad 1 as described above, the body fluid that diffuses along the fiber orientation is almost the same as the fiber orientation. The body fluid easily enters the slit 20 extending in the perpendicular width direction, the body fluid easily moves to the lower layer side through the slit 20, and the body fluid is less likely to remain on the top sheet 3, so that the sticky feeling on the surface can be reduced. That is, since the fibers of the topsheet 3 are cut by the slits 20, the diffusion of body fluids along the fibers of the topsheet 3 is significantly suppressed by the slits 20, and it becomes difficult for the body fluids to spread outside the slits 20. The diffusion area can be kept small. Therefore, the amount of body fluid remaining in the nonwoven fabric made of cellulose fibers of the top sheet 3 is small, and the sticky feeling on the surface is reduced.

As shown in FIG. 1, the length X of the slit 20 along the direction in which the slit 20 extends is preferably 10 to 60 mm, preferably 20 to 60 mm, and more preferably 40 to 60 mm. If the length X of the slit 20 is too short, body fluids tend to go around both ends of the slit 20 and diffuse outward. Further, if the length is longer than 60 mm, the top sheet 3 may curl up at the slit 20 portion, which tends to cause discomfort when worn, and also makes it easy for body fluids to flow back. As long as the length X of the slit 20 is within the above range, all the slits 20, 20... arranged in plurality in the longitudinal direction may be formed with approximately the same length, or may be formed with different lengths. It is optional. In the example shown in FIG. 1, all the slits 20 are formed to have approximately the same length. When the slits 20 are formed with different lengths, it is preferable that the slits 20 located on the outside of the body fluid discharge part H are longer than the slit 20 located in the center of the body fluid discharge part H. Thereby, the body fluid that goes around both ends of the slit 20 arranged at the center of the body fluid discharge part H and diffuses to the outside can be transferred to the lower layer side by the outer slit 20 formed longer than this. .

The length X of the slit 20 is preferably smaller than the widthwise separation width of the side nonwoven fabrics 7, 7 on both sides, and is preferably formed with a length extending outward from the area corresponding to the body fluid discharge part H of the wearer. . Specifically, as shown in FIG. 1, the length is approximately 0.3 to 0.7 times, preferably 0.4 to 0.6 times, the separation width M of the side nonwoven fabrics 7, 7 on both sides. It is best to form it with

The distance P between the slits 20, 20 adjacent to each other in the longitudinal direction of the light incontinence pad 1 is preferably shorter than the length X of the slit 20, specifically, 5 to 50 mm, preferably 10 to 50 mm, or more. Preferably it is 30 to 50 mm. In the example shown in FIG. 1, the intervals P are approximately equal intervals, but may be different intervals. If they are arranged at different intervals, it is preferable that the intervals are wider on the outer side of the body fluid discharge part H than on the center side.

As shown in FIG. 6, the width C of the slit 20 (maximum width of the slit 20) is preferably 3 mm or less, preferably 0.1 to 3 mm. The slit 20 is cut with a roll cutter and has almost no width, and the slit 20 has the effect of suppressing body fluid diffusion by tearing the fiber orientation. Although it is not necessary to widen the top sheet 3 to a predetermined width, when joining the top sheet 3 to the absorbent body 4 side, the top sheet 3 may be stretched in the longitudinal direction so that the slits 20 have a predetermined separation width. This is preferable because the effect of suppressing body fluid diffusion is promoted. If the width of the slit 20 is made too large, the flexibility of the cellulose fibers will be lost in the slit 20 portion, which may reduce the feeling of wearing and also make it more likely that the fabric will return from the slit 20.

As shown in FIG. 4(B), the top sheet 3 has a nonwoven fabric layer 3a made of cellulose fibers on the skin side and a nonwoven fabric layer 3b made of synthetic fibers on the non-skin side, which are joined by fiber entanglement. In the case of a layered structure, the slit 20 is preferably formed so as to integrally penetrate these nonwoven fabric layers 3a and 3b.

Moreover, when the said second sheet 6 is arrange|positioned on the non-skin side of the said top sheet 3, it is preferable that the said slit 20 penetrates these top sheet 3 and the second sheet 6 integrally, and is formed. This makes it easier for body fluids that have entered the slits 20 to transfer to the absorbent body 4.

As shown in FIG. 7, it is preferable that a burr 21 protruding toward the non-skin side is formed on the periphery of the slit 20. This burr 21 is formed by cutting the slit 20 from the surface side of the topsheet 3 using a cutter roll or the like, so that the fiber ends around the slit 20 are stretched toward the non-skin side and protrude. By causing the burr 21 to protrude toward the non-skin side, bodily fluids can easily migrate to the non-skin side along the burr 21, and the amount of liquid remaining on the top sheet 3 is further reduced.

Next, a modification of the slit 20 will be described. As shown in FIG. 8, second slits 22 extending along the longitudinal direction are spaced apart from each other on both sides of the slits 20 arranged along the width direction, 22 may be formed. By providing the second slit 22, it is possible to prevent the body fluid from flowing around both sides of the slit 20 and diffusing to the outside, thereby further promoting the movement of the body fluid to the lower layer side. The second slit 22 is formed with a length extending outward in the longitudinal direction of the light incontinence pad 1 from the arrangement range of the plurality of slits 20 extending in the width direction, so that the second slit 22 extends around both side edges of the slit 20. This is preferable from the viewpoint of preventing the particles from diffusing outward. The second slit 22 may be a continuous line extending in the longitudinal direction of the light incontinence pad 1, as shown in the illustrated example, or may be an intermittent line extending in the center between adjacent slits 20, 20. When used as an intermittent line, the intermittent length along the second slit 22 should be approximately 0.1 to 0.3 times the distance P between the adjacent slits 20, 20 in the width direction from the second slit 22. This is preferable from the viewpoint of preventing bodily fluids from dispersing to the outside. The distance between the slit 20 and the second slit 22 in the width direction of the incontinence pad 1 is preferably 2 to 10 mm.

As shown in FIG. 9, among the slits 20 arranged along the width direction, the slits 20 arranged at the front and rear ends are spaced apart from each other at the front and back of both ends of the light incontinence pad 1. Third slits 23, 23, . . . extending in the direction may be arranged. By arranging the third slit 23, it is possible to prevent body fluids from spreading outside by going around both ends of the slits 20, 20 arranged at the front and rear ends. In the illustrated example, the third slit 23 is arranged only on the outside of the slits 20, 20 at the front and rear ends, but it is arranged on the outside of the middle slit 20, 20 (that is, in the middle part between the adjacent slits 20, 20). May be placed.

As another modification, as shown in FIG. 10, the planar shape of the slit 20 may be formed into a curved shape that bulges outward with respect to the center of the region corresponding to the wearer's body fluid discharge portion H. It's okay. That is, it is formed in a curved line that is concave toward the center of the wearer's body fluid discharge portion H. Thereby, body fluid accumulates in the curved concave portion and easily moves to the non-skin side through the slit 20, and it is possible to reduce the body fluid that goes around both ends of the slit 20 and diffuses to the outside.

As shown in FIGS. 11 to 13, when the top sheet 3 has a two-layer structure in which a non-woven fabric layer 3a made of cellulose fibers on the skin side and a non-woven fabric layer 3b made of synthetic fibers on the non-skin side are joined. , or when the second sheet 6 made of synthetic fiber is laminated on the non-skin side of the top sheet 3, the slit 20 is placed at a position straddling the slit 20 of the nonwoven fabric layer 3b made of synthetic fiber or the second sheet 6. A fused portion 24 may be formed by partially fusing the synthetic fibers on both sides of the fibers. As shown in FIG. 13, the fused portion 24 is a recessed portion in which the surface on the nonwoven fabric layer 3b or second sheet 6 side is depressed toward the skin side. By providing the fused portion 24, some of the synthetic fibers fused in the fused portion 24 solidify while entering the nonwoven fabric layer 3a or top sheet 3 made of cellulose fibers, so that the non-skinned fibers in the slit 20 are solidified. Since the sides are partially joined, it is possible to prevent the slit 20 from opening or bending, and it is possible to suppress a decrease in wearing comfort. In the fused portion 24, only the non-woven fabric made of synthetic fibers on the non-skin side is thermally fused, and the non-woven fabric made of cellulose fibers on the skin-contacting side is not fused. Diffusion of body fluids from one side to the other side is suppressed. The fused parts 24 can be arranged in plural numbers at one or a predetermined interval in the direction in which the slit 20 extends.

In addition, as shown in FIG. 14, in order to prevent the ends of the slits 20 from tearing, synthetic fibers are added to the nonwoven fabric layer 3b made of synthetic fibers or the second sheet 6 at positions overlapping with the ends of the slits 20. A partially fused portion 25 may be formed. Since the ends of the slit 20 are reinforced by providing the fused portion 25, tearing of the ends of the slit 20 can be prevented even if an external force in the tearing direction is applied due to friction with the skin.

The slit 20 may be formed by a continuous line cut continuously over the entire length of the slit 20, as shown in FIG. By providing one or more uncut portions 27 along the direction, the plurality of cut portions 26 may be formed by intermittent lines arranged intermittently. By forming the intermittent line with the uncut portions 27, the slit 20 is prevented from opening, and deterioration of the wearing feeling and relapse can be more reliably prevented. The length D of the uncut portion 27 along the direction in which the slit 20 extends is 0.02 to 0.25 times, preferably 0.05 to 0.1 times the length X of the slit 20. Good. The specific length D of the uncut portion 27 is preferably 1 to 8 mm, preferably 1 to 4 mm. If D is too small, the uncut portion 27 will be likely to tear due to friction with the skin when worn. On the other hand, if it is too large, bodily fluids will easily diffuse outside the slit 20 through the uncut portion 27.

A test was conducted to determine the relationship between the slit length X and the body fluid diffusion area S. The test method is as follows.

(1) A test sample is prepared in which a back sheet 2, an absorbent body 4, and a top sheet 3 made of cellulose fibers in which two slits 20, 20 are formed in parallel are laminated. Note that the separation width between the two slits 20, 20 is 20 mm.
(2) Place an injection cylinder vertically on the upper surface of the top sheet 3 of the test sample, in the center between the slits 20, 20, and inject 0.2 ml of artificial urine from the upper opening of the injection cylinder. do. The artificial urine contains urea: 2 wt%, sodium chloride: 0.8 wt%, calcium chloride dihydrate: 0.03 wt%, magnesium sulfate heptahydrate: 0.08 wt%, and ion exchange water: 97.09 wt%. % and used at a temperature of 37 degrees unless otherwise specified.
(3) For 10 minutes after injection, the injection tube is left standing on the test sample, and after 10 minutes, only the top sheet 3 is isolated from the test sample.
(4) An image of the surface of the isolated topsheet 3 is taken and imported into a computer, and the diffusion area of the artificial urine is measured.

The measurement results are shown in Table 1.

In Table 1, the diffusion area S is expressed as a ratio of 100 when the slit length X is 0 mm (when the slit 20 is not formed). In this test, the lowest line of diffusion area at which a wet feeling could be clearly recognized when touching the entire surface of the test sample with your hand was around 90%, so the minimum effective range of the slit 20 was set to 90% or less. It was set to As the diffusion area S becomes smaller, the degree of wet feeling decreases.

From the above results, when the slit length The feeling can be reduced.

DESCRIPTION OF SYMBOLS 1... Light incontinence pad, 2... Back sheet, 3... Top sheet, 4... Absorber, 5... Covering sheet, 6... Second sheet, 7... Side nonwoven fabric, 8... Thread-like elastic elastic member, 12... Hole, 13 ...Vertical stripe, 14...Horizontal stripe, 20...Slit, 21...Burr, 22...Second slit, 23...Third slit, 24...Fused part, 25...Fused part, 26...Cut part, 27...Uncut part

Claims (5)

The top sheet forming the skin contact surface is composed of a non-woven fabric layer made of cellulose fibers on the skin side and a non-woven fabric layer made of synthetic fibers on the non-skin side, which are combined by intertwining the fibers, or are made of cellulose fibers. The non-skin surface sheet has a single-layer structure of a non-woven fabric made of or a two-layer structure in which a non-woven fabric layer made of cellulose fibers on the skin side and a non-woven fabric layer made of synthetic fibers on the non-skin side are combined by fiber entanglement. A second sheet made of synthetic fiber is placed on the side,
The nonwoven fabric made of cellulose fibers is composed of a spunlace nonwoven fabric,
The fibers of the nonwoven fabric made of cellulose fibers are oriented along the longitudinal direction of the absorbent article,
In a region of the top sheet corresponding to a body fluid discharge part of the wearer, slits are provided at intervals in the longitudinal direction, and extend through the top sheet and cross the longitudinal center line of the absorbent article in the width direction. Multiple formations ,
An absorbent article characterized in that the non-skin side nonwoven fabric layer or the second sheet is formed with a fused portion that partially fuses the synthetic fibers on both sides of the slit so as to straddle the slit. . The absorbent article according to claim 1, wherein the length of the slit is 10 to 60 mm. The absorbent article according to any one of claims 1 and 2 , wherein a second sheet made of synthetic fiber is disposed on the non-skin side of the top sheet, and the slit is formed to penetrate the top sheet and the second sheet. . The absorbent article according to any one of claims 1 to 3 , wherein a burr protruding toward the non-skin side is formed on the periphery of the slit. The absorbent article according to any one of claims 1 to 4 , wherein the planar shape of the slit is a straight line or a curved line that bulges outward from the center of the region corresponding to the wearer's body fluid discharge part.

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