JP4364247B2 - Absorbent articles - Google Patents

Description

  The present invention relates to an absorbent article that absorbs bodily fluids.

  Conventional absorbent articles that absorb bodily fluids such as disposable diapers, incontinence pads, sanitary napkins, etc. generally have a water-permeable surface-side sheet facing the body side, a back-side sheet facing the clothing side, and a body fluid contained in them. It consists of a liquid-absorbing core that absorbs, and body fluid released from the user is absorbed by the liquid-absorbing core through the surface side sheet.

  The bodily fluid that has reached the upper surface of the liquid-absorbent core via the surface-side sheet is sequentially absorbed by the liquid-absorbent core made of a hydrophilic material. At this time, in order to reduce the discomfort felt by the wearer as much as possible, urine and body fluid are quickly transferred from the surface side sheet to the liquid absorbent core, and urine and body fluid return from the liquid absorbent core to the surface sheet side. Less is needed. On the other hand, the user throws away the product after using these products, but when the product is thrown away, it is not only the user other than the user but also the user that he / she sees the part where the body fluid has adhered. Even the person himself feels uncomfortable.

  For this reason, in order to conceal the wetted part of the liquid-absorbent core with urine and body fluid and improve the absorbency, a sublimated and high-weight hydrophilic nonwoven fabric is used as a surface material and as a second sheet placed directly under it. ing.

  As mentioned above, research on materials for absorbent cores, etc., has been actively conducted to improve the absorbability of products, and in terms of increasing the absorbability of bodily fluids, some success has been achieved. ing. However, if the nonwoven fabric has a sufficient concealing effect, it is necessary to increase the weight per unit area and increase the density. On the other hand, the body fluid transfer from the surface side sheet to the liquid absorbent core is impaired, or the body fluid remaining in the surface side sheet May increase. Moreover, an absorbent article may become hard and may impair the wearer's feeling of wear.

  The present invention has been made in view of such a viewpoint, and its purpose is to improve the absorbability and fluid retention of the absorbent article by modifying the configuration of the absorbent article, and to improve the body fluid. It is an object of the present invention to provide an absorbent article that also improves concealment and can reduce discomfort felt by the user.

  In order to solve the problems as described above, the absorbent article according to the present invention is provided with a body fluid-permeable sheet between the surface-side sheet and the liquid-absorbent core, and adjusts the fiber density gradient of the sheet, By providing a hydrophobic hydrophobic layer on the liquid-absorbent core side of the body fluid-permeable sheet, the absorbability and body fluid retention of the absorbent article are improved, and the discomfort felt by the user is reduced.

  More specifically, the present invention provides the following.

(1) A water-permeable surface-side sheet facing the body side, a back-side sheet facing the clothing side, a liquid-absorbing core having a function of absorbing body fluid contained in the surface-side sheet and the back-side sheet In the absorbent article comprising: a body fluid permeability between the surface side sheet and the liquid absorbent core, the fiber density on the side facing the liquid absorbent core is greater than the fiber density on the side facing the surface side sheet A sheet is provided, and the surface of the body fluid permeable sheet on the liquid-absorbent core side is a flat surface having a SMD value of 2.0 to 4.5 μm, which is a parameter obtained from an average deviation of surface roughness by a hot roll. The surface is smoothened and densified at the same time , and a hydrophobic layer formed by printing a color or design with hydrophobic ink is provided on the smoothed and densified surface. It is characterized by being The absorbent article.

(2) A water-permeable surface-side sheet facing the body side, a back-side sheet facing the clothing side, a liquid-absorbent core that is included in the surface-side sheet and the back-side sheet and has a function of absorbing bodily fluids A body fluid whose fiber density increases between the surface-side sheet and the liquid-absorbent core from the side facing the surface-side sheet toward the liquid-absorbent core. A permeable sheet is provided, and the surface of the body fluid permeable sheet on the liquid-absorbent core side has a flatness of 2.0 to 4.5 μm with an SMD value that is a parameter determined by an average deviation of surface roughness. As a result, the surface is smoothened and densified at the same time , and a hydrophobic layer formed by printing a color or a pattern with hydrophobic ink is provided on the smoothed and densified surface. Absorbency characterized by Goods.

(3) A water-permeable surface-side sheet facing the body side, a back-side sheet facing the clothing side, a liquid-absorbent core that is included in the surface-side sheet and the back-side sheet and has a function of absorbing bodily fluids A process for producing a body fluid permeable sheet having a density gradient such that the fiber density increases from one surface to the other surface, and the body fluid permeability Smoothing and further densifying the surface of the sheet on the liquid-absorbent core side, and applying a color or design to the liquid-absorbent core side surface of the body fluid-permeable sheet with hydrophobic ink. The manufacturing method of an absorbent article including the process of performing the printing which provides hydrophobicity, and the process of pinching | interposing between the said surface side sheet | seat toward the said liquid-absorbent core the surface which performed the said printing.

  According to the present invention, “a water permeable front side sheet facing the body side, a back side sheet facing the garment side, an absorbent having a function of absorbing body fluid contained in the front side sheet and the back side sheet”. In an absorbent article comprising a liquid core, between the surface side sheet and the liquid absorbent core, the fiber density on the side facing the liquid absorbent core is greater than the fiber density on the side facing the surface side sheet. By providing a large body fluid permeable sheet and providing a hydrophobic layer formed by printing a color or a pattern on the liquid absorbent core side between the body fluid permeable sheet and the liquid absorbent core. '' It becomes possible to improve the diffusibility, retention, and concealment of the released body fluid.

  Embodiments of the present invention will be described below with reference to the drawings. In the following description, a liquid absorbent pad used for a so-called disposable diaper is described as being suitable for using the absorbent article of the present invention, but the method of using the absorbent article of the present invention is described here. It is not limited, and can be used for products that absorb bodily fluids such as so-called sanitary napkins.

  In the present embodiment, “width” means “short direction” of disposable diapers, etc., “length” means “longitudinal direction” of disposable diapers, and “thickness”. "Means the" height direction "of disposable diapers and the like.

[Feature Description]
FIG. 1 is a schematic perspective view showing the disposable liquid absorbent pad of the present embodiment.

  The disposable liquid absorption pad 10 is a pad-type disposable diaper, which is fixed by attaching a paper or cloth diaper, pants, etc. so as to cover the outer surface after being worn so as to be sandwiched between both thighs. It is.

  This disposable liquid-absorbing pad 10 has waist regions 20 and 21 in the longitudinal direction intersecting the width direction, and a crotch region 22 positioned between these waist regions 20 and 21, and is opposed to each other in the longitudinal direction. Both side edges 23, 24 that curve inwardly at the crotch region 22 and bend inward of the disposable liquid absorbent pad 10, and both end edges 25, 26 that cross both side edges 23, 24 and extend in the width direction opposite to each other. It has a front / rear object and a symmetrical type.

  A liquid-permeable top sheet 31 faces the widthwise central portion over the waist regions 20 and 21 and the crotch region 22, and will be described later together with a liquid-impermeable back sheet 41 (see FIG. 2) described later. The absorbent core 51 (see FIG. 3) is included.

  Moreover, the disposable liquid absorption pad 10 has the leak-proof cuffs 61 and 71 (refer FIG. 2) which join the top sheet 31, the back sheet 41, and the liquid-absorbent core 51 which were mentioned above to both the side edges 23 and 24, As will be described later, the disposable liquid absorbing pad 10 is bent inward by a plurality of elastic members 62, 63, 64, 72, 73, 74 (see FIG. 2) present in the leak-proof cuffs 61, 71.

  Furthermore, the disposable liquid absorbent pad 10 has pockets 27 and 28 recessed in the direction of the non-skin contact surface of the disposable diaper 10 from the vicinity of the center of the crotch region 22 to the edges 25 and 26 of the waist regions 20 and 21. The pockets 27 and 28 have a function of accumulating solid discharge. In addition, the disposable liquid absorption pad 10 of this embodiment is a back-and-forth symmetrical type, and when using the waist area 20 as a front surface, the pocket 28 has a function of accumulating solid discharge, and the waist area 21 Is used as the front surface, the pocket 27 has a function of accumulating solid discharge.

  Further, a fold line 29 extending in the width direction is formed at the center of the crotch region 22, and even when the waistline region 20 is a front surface and the waistline region 20 is folded so that the apex is on the body side. In addition, the waistline region 21 and the crotch region 22 are configured not to cause wrinkles.

[Configuration of absorbent article]
FIG. 2 is an exploded perspective view showing the disposable liquid absorbent pad 10 of the present embodiment, and FIG. 3 is a cross-sectional view showing the disposable liquid absorbent pad 10 of the present embodiment. 2 is drawn assuming that the leak-proof cuffs 61 and 71 are not contracted by the plurality of elastic members 62, 63, 64, 72, 73, and 74.

  As shown in FIG. 2, the disposable liquid-absorbing pad 10 includes a liquid-permeable top sheet 31, a liquid-impermeable back sheet 41, and a liquid-absorbent core 51 (between the top sheet 31 and the back sheet 41. 3) and a second sheet 81 that is a “body fluid permeable sheet” interposed between the top sheet 31 and the liquid absorbent core 51, and the top sheet 31, the back sheet 41, and the liquid absorbent core. 51, and a pair of leak-proof cuffs 61, 71 extending in the longitudinal direction.

  The above-described top sheet 31 comes into contact with the body side when worn, and a liquid-permeable sheet such as a liquid-permeable nonwoven fabric or a perforated plastic film is used.

  Further, the back sheet 41 mentioned above comes into contact with the clothes side when worn, and a liquid-impervious plastic film or a laminate sheet of a plastic film and a hydrophobic non-woven fabric, preferably a gas-impermeable liquid-impervious sheet is used. Is done.

  The liquid-absorbing core 51 described above is a two-layer type liquid-absorbing core. And liquid packaging sheets 121 and 151.

  The upper layer liquid absorbing liquid 101 and the lower layer liquid absorbing liquid 131 are a mixture of fluff pulp and superabsorbent polymer particles, compressed to a required thickness, and entirely covered with packaging sheets 121 and 151 having water permeability such as tissue paper. Has been.

  In addition, although the liquid absorbing core 51 in the present embodiment has the above-described configuration, the present invention is not limited to this configuration, and for example, a high-absorbing sheet or the like may be sandwiched. A type of liquid-absorbent core may be used.

[Description of body fluid permeable sheet]
As shown in FIG. 3, there is a sublime second between the top sheet 31 that is “a water-permeable surface-side sheet facing the body” and the liquid-absorbent core 51 that “has a function of absorbing bodily fluids”. The sheet 81 is located. Although the second sheet 81 and the top sheet 31 are fixed to each other, FIG. 3 shows a state in which the respective sheets are not fixed for convenience of explanation. In addition, the second sheet 81 and the liquid-absorbent core 51 are also fixed, but are not illustrated in FIG.

  FIG. 4 shows an enlarged cross-sectional view of the second sheet 81. As shown in FIG. 4, the second sheet 81 is composed of two-layer structure fiber layers 81a and 81b. As described above, the fiber layer 81a is fixed to the top sheet 31 with an adhesive such as a hot melt adhesive. As a fixing method, in addition to the method using the hot melt adhesive described above, heat welding such as hot embossing may be used.

  The fiber layer 81a is a nonwoven fabric formed using an initial hydrophilic oil agent, has a core-sheath structure mainly composed of polyethylene and polypropylene, and the fiber layer 81b is a nonwoven fabric formed using a durable hydrophilic oil agent. It has a core-sheath structure mainly composed of polyethylene and polyethylene terephthalate.

  Further, the fiber layer 81a has a lower fiber density than the fiber layer 81b. Thus, it becomes possible to increase the water absorption of the second sheet 81 by increasing the fiber density as the distance from the body-facing surface increases.

  In the present embodiment, the second sheet 81 has a two-layer structure using two fiber layers having different fiber densities, but the present invention is not limited to this. That is, if the fiber density increases from the top sheet 31 side toward the liquid-absorbent core 51 side, the object of the present invention is realized regardless of whether the layer is a single layer or three or more layers. It can be done.

  In the present embodiment, the fiber layer 81a has a core-sheath structure mainly composed of polyethylene and polypropylene, and the fiber layer 81b has a core-sheath structure mainly composed of polyethylene and polyethylene terephthalate. However, the present invention is not limited thereto, and the fiber layers 81a and 81b may have a single fiber structure or a hollow structure whose main material is polyethylene, polypropylene, polyethylene terephthalate, or the like. Further, the difference in fiber density can also be realized by a method in which the fiber diameter of the fiber used is different.

  A hydrophobic layer having hydrophobicity is formed on the liquid absorbent core 51 side of the fiber layer 81b (see FIG. 5). The material used as the hydrophobic layer is hydrophobic enough to diffuse the body fluid over the entire surface of the liquid-absorbent core 51, and the body fluid tends to be absorbed by the liquid-absorbent core 51. It is preferable that the amount does not hinder.

  For example, as shown in FIG. 5 (A), it is possible to provide a hydrophobic layer 90 formed of hydrophobic fibers. However, when the hydrophobic layer has a thickness, the liquid absorbent core 51 absorbs the body fluid. Therefore, it is necessary to reduce the cross-sectional thickness.

  According to experiments, it can be seen that the object of the present invention can be more effectively realized if the second sheet 81 and the hydrophobic layer are combined and have a cross-sectional thickness of about 1.5 to 2.0 mm. As shown in FIG. 5B, when the hydrophobic layer 91 is formed by printing on the surface 81c (see FIG. 4) of the fiber layer 81b on the liquid-absorbent core 51 side with hydrophobic ink or the like, Since the cross-sectional thickness of the hydrophobic layer also satisfies the above criteria, it is more preferable that the hydrophobic layer 51 does not interfere with the absorption of the body fluid while having diffusibility.

  As the ink for printing the surface of the fiber layer 81b in contact with the liquid-absorbent core 51, an ink that does not dissolve in body fluid or the like is preferable in consideration of after the absorbent article has absorbed body fluid. Examples of such an ink include an ink having a content of 0 to 50% for pigment, 15 to 25% for binder resin, and 35 to 80% for water. Moreover, the gravure coating method is used for printing.

  The surface 81c on which printing is performed is smoothed and further densified by a hot roll during manufacturing in order to facilitate printing. There is a KES system (Kato Tech Co., Ltd.) as a quantitative evaluation method of the surface smoothness of a fabric such as a non-woven fabric, and its characteristics can be clearly defined by this KES-FB4 measurement evaluation system. With this system, the smoothness of the surface 81c is preferably 2.0 to 4.5 (μm) in SMD value, which is a parameter obtained from the average deviation of the surface roughness.

  Furthermore, if color printing is performed on the surface 81c of the fiber layer 81b, a clean feeling can be appealed before use, and the concealability after absorbing bodily fluid after use can be improved. be able to. As a color satisfying these two effects, for example, green or blue is suitable. In addition to the above effects, the body fluid can be diffused in a more preferable direction by printing with a design. As a design satisfying this effect, a large design is arranged in a highly absorbent portion located near the center of the liquid absorbent core 51, and a small design is arranged in a peripheral portion having a low absorbency. It is preferable to print.

[Action]
The operation of the disposable liquid absorbing pad 10 of the present embodiment configured as described above will be described.

  As shown in FIG. 6, the disposable liquid absorbent pad 10 is in a state where the color printed on the liquid absorbent core 51 side of the second sheet 81 can be visually recognized from the water-permeable top sheet 31 side facing the body side. is there. As described above, the color visually recognized is printed on the surface of the second sheet 81 opposite to the top sheet 31 (see FIG. 3). By setting it as such a structure, it will be reflected in a light color so that a user's eyes of the disposable liquid absorption pad 10 may feel cleanliness. In addition, by making the color moderately light, the pressing force to conceal the color of the bodily fluid absorbed before use is not felt, so that the user can have a favorable feeling as touching the user's skin. In the disposable liquid-absorbing pad 10, absorption of body fluid starts when the user releases the body fluid.

  The bodily fluid released from the user reaches the upper surface of the second sheet 81 through the top sheet 31. As shown in FIG. 5A, the second sheet 81 includes a fiber layer 81a having a relatively low fiber density and a fiber layer 81b having a relatively high fiber density, and has reached the upper surface of the second sheet 81. The body fluid moves so as to be guided to the higher fiber density gradient (that is, the + Y direction shown in FIG. 5B). The moved body fluid reaches the upper surface of the hydrophobic layer 91 formed by printing on the surface 81c (see FIG. 4) of the fiber layer 81b.

  The body fluid that has reached the upper surface of the hydrophobic layer 91 is gradually absorbed by the liquid absorbent core 51 by the capillary force of the fibers constituting the liquid absorbent core 51. At this time, since the hydrophobic layer 91 has hydrophobicity, the body fluid diffuses on the upper surface of the hydrophobic layer 91 (that is, the body fluid spreads in the X direction shown in FIG. 5B). Thereby, the liquid absorptive core 51 will be able to exhibit the absorptivity over a wide range.

  FIG. 7 and FIG. 8 show data supporting the above-described “improvement of diffusion”. FIG. 7 is an explanatory diagram showing a method for testing the absorbency of the absorbent article. The experiment was performed three times as shown in FIG. 11, and the average value was calculated. In FIG. 7, the longitudinal direction of the second sheet 81 is described as the MD direction, and the width direction is described as the CD direction. In the experiment, five sheets of filter paper 141 were laminated below the second sheet 81 with the surface 81c of the fiber layer 81b below, and the liquid was dropped from above the second sheet 81 at a timing of 1 cc / sec. This is done by measuring the diffusion range of the liquid on 141. The experiment is performed on both the printed second sheet and the unprinted second sheet.

  FIG. 8 shows experimental result data. As is apparent from FIG. 8B, the second sheet 81 that has been printed has a wide diffusion range in both the MD direction (longitudinal direction) and the CD direction (width direction), but is not printed. In the second sheet 81, the diffusion range is narrow.

  As described above, by performing printing on the liquid-absorbent core 51 side of the second sheet 81, a hydrophobic layer having a function of improving diffusibility is formed. Thereby, since the liquid absorptive core 51 can exhibit the absorptivity over a wide range, the performance which absorbs a bodily fluid will also improve.

  On the other hand, due to the hydrophobicity of the hydrophobic layer 91, the water retention of the liquid-absorbent core 51 is increased. Specifically, the bodily fluid absorbed by the absorbent core 51 is prevented from returning in the reverse direction (that is, the −Y direction shown in FIG. 5B) due to the hydrophobicity of the hydrophobic layer 91, and absorbed. The discharged waste can be accumulated further from the body side.

  FIG. 9 and FIG. 10 show data supporting “improvement of body fluid retention” as described above. FIG. 9 is an explanatory diagram showing a method for experimenting body fluid retention of an absorbent article. The experiment was performed five times as shown in FIG. 12, and the average value was calculated. As shown in FIG. 9, in this experiment, ground pulp 142 (100 g / square meter) was placed below the second sheet 81 with the surface 81c of the fiber layer 81b facing downward, and 1 cc / second (from the top of the second sheet 81) The first stage is to drop the liquid at the timing of 5 cc / 5 seconds in FIG. 9A and inject the liquid into the second sheet 81 (see FIG. 9A). Then, as a second stage, after 15 seconds, the filter paper 141 is laminated above the second sheet 81, and the second sheet 81 is pressed from above the filter paper 141 using the weight (5 kg, 10 cm square) of the weight 143, and the load 10 seconds after the measurement, the amount of the reversed liquid detected on the filter paper 141 is measured (see FIG. 9B). The experiment is performed on both the printed second sheet and the unprinted second sheet.

  FIG. 10 shows experimental result data. As is apparent from FIG. 10B, the second sheet 81 that has been printed has a small liquid return amount of 1.8 g on average, whereas the second sheet 81 that has not been printed has a liquid return amount. Is as large as 2.5 g.

  As described above, by performing printing on the liquid-absorbent core 51 side of the second sheet 81, the liquid return amount from the liquid-absorbent core 51 is reduced due to its hydrophobicity. Thereby, the liquid-absorbent core 51 can improve its body fluid retention.

  Furthermore, the ink that forms the hydrophobic layer 91 reduces the color difference between the part where the body fluid is stained and the other part. Thereby, the color of the bodily fluid absorbed by the disposable liquid absorption pad 10 becomes inconspicuous, and the user can reduce feeling of discomfort when the disposable liquid absorption pad 10 after use is discarded. .

  By using the absorbent article configured as described above for a disposable liquid absorption pad, it gives the user a sense of cleanliness before use, improves the absorbability by increasing the diffusibility of body fluids during use, and after use Can improve the concealability while improving the retention of the absorbed body fluid.

It is a schematic perspective view which shows the disposable absorbent pad using the absorbent article in this embodiment. It is a disassembled perspective view which shows the disposable liquid absorption pad using the absorbent article in this embodiment. It is sectional drawing which shows the outline of the disposable liquid absorption pad using the absorbent article in this embodiment. It is sectional drawing which shows the outline of the bodily fluid permeable sheet of the absorbent article in this embodiment. It is sectional drawing which shows the outline of the bodily fluid permeable sheet and hydrophobic layer of the absorbent article in this embodiment. It is a schematic perspective view which shows the outline of the disposable liquid absorption pad using the bodily fluid permeable sheet of the absorbent article in this embodiment. It is explanatory drawing explaining the method of experimenting the diffusibility of the absorbent article in this embodiment. It is explanatory drawing which shows the numerical value which experimented the diffusibility of the absorbent article in this embodiment as data. It is explanatory drawing explaining the method of experimenting the bodily fluid retainability of the absorbent article in this embodiment. It is explanatory drawing which shows the numerical value which experimented the bodily fluid retainability of the absorbent article in this embodiment as data. It is a table | surface which shows the result of the experiment in FIG.7 and FIG.8. It is a table | surface which shows the result of the experiment in FIG.9 and FIG.10.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10, 211 Disposable liquid absorption pad 20, 21 Girth area 22 Inseam area 22a Center part 23, 24 Side edge 25, 26 Edge 27, 28 Pocket 31 Top sheet 41 Back sheet 51 Liquid absorbing core 61, 71 Leak-proof cuff 62 , 63, 64, 72, 73, 74 Elastic member 81 Second sheet 81a, 81b Fiber layer 81c Surface 90, 91 Hydrophobic layer 101 Upper layer liquid absorbent 121 Packaging sheet 131 Lower layer liquid absorbent 141 Filter paper 142 Crushed pulp 143 Weight

Claims (3)

A water-permeable surface-side sheet facing the body side;
A back side sheet facing the clothing side;
A liquid-absorbent core having a function of absorbing a body fluid contained in the front-side sheet and the back-side sheet;
In an absorbent article comprising:
Between the surface side sheet and the liquid absorbent core is provided a body fluid permeable sheet having a fiber density on the side facing the liquid absorbent core larger than the fiber density on the side facing the surface side sheet,
The surface on the liquid-absorbent core side of the body fluid permeable sheet is set to have a flatness of 2.0 to 4.5 μm with an SMD value which is a parameter obtained from an average deviation of surface roughness by a hot roll. , Smoothing and densifying at the same time ,
An absorbent article, characterized in that a hydrophobic layer formed by printing a color or a pattern with a hydrophobic ink is provided on the smoothed and densified surface. A water-permeable surface-side sheet facing the body side;
A back side sheet facing the clothing side;
A liquid-absorbent core having a function of absorbing a body fluid contained in the front-side sheet and the back-side sheet;
In an absorbent article comprising:
Between the surface side sheet and the liquid absorbent core, a body fluid permeable sheet is provided in which the fiber density increases from the side facing the surface side sheet toward the side facing the liquid absorbent core,
Surface of the liquid-absorbent core side of the body fluid permeable sheet, so that the flatness of 2.0~4.5μm in SMD value is a parameter determined by the mean deviation of surface roughness, a smoothing Absorption characterized by having a hydrophobic layer formed by printing a color or a pattern with hydrophobic ink on the smoothed and densified surface simultaneously with the density Sex goods. A water-permeable surface-side sheet facing the body side;
A back side sheet facing the clothing side;
A liquid-absorbent core having a function of absorbing a body fluid contained in the front-side sheet and the back-side sheet;
A method of manufacturing an absorbent article comprising:
Producing a body fluid permeable sheet having a density gradient such that the fiber density increases from one surface to the other surface;
Smoothing and further densifying the surface of the absorbent core side of the body fluid permeable sheet; and
A step of applying a color or a pattern with hydrophobic ink on the surface of the body fluid-permeable sheet on the liquid-absorbent core side to perform hydrophobicity; and
And a step of sandwiching the printed surface between the surface-side sheet and facing the liquid-absorbent core.

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