JPH044742Y2 - - Google Patents

Description

[Detailed Description of the Invention] (Industrial Application Field) This invention relates to a top sheet of a disposable diaper that forms the absorbing surface of excreted urine and comes into contact with the user's skin.

(Prior art) Conventionally, a water-absorbent body made of pulverized pulp, superabsorbent polymer, etc. is encapsulated with a water-permeable top sheet and a water-impermeable back sheet, and excreted urine passes through the top sheet and is absorbed inside the top sheet. Disposable diapers are known in which water is absorbed and retained by a water absorbent body located in the body.

The top sheet of such a disposable diaper is desired to have the ability to quickly guide excreted urine to the water absorbent body, eliminate residual moisture on the top sheet, and prevent moisture from penetrating from the water absorbent body.

In order to satisfy such performance, the top sheet is formed of two layers of upper and lower non-woven fabrics, the upper layer in contact with the skin is rough and the lower non-woven fabric in contact with the water-absorbing body is hydrophilic, as disclosed in JP-A-61-2854. has been disclosed.

(Problems to be solved by the invention) The surface sheet disclosed in the above-mentioned Japanese Patent Application Laid-Open No. 61-2854 exhibits a certain degree of effectiveness in terms of liquid conductivity to the water absorbent body and prevention of leakage from the water absorbent body to the surface. However,
I still wasn't completely satisfied.

Since the top sheet of disposable diapers comes into direct contact with the baby's flexible skin, it is required to have a soft surface and good conformability to the skin, but conventional top sheets made of non-woven fabrics are not always suitable in this respect. It wasn't enough.

(Means for Solving the Problems) In order to solve the above problems, the means adopted by this invention consist only of heat-adhesive composite fibers in which a high melting point component is coated with a low melting point component and subjected to hydrophilic treatment. It consists of two layers, upper and lower, and an intermediate layer consisting of a mixture of coarse water-based heat-adhesive composite fibers in which a high melting point component is coated with a low melting point component and other non-thermally adhesive fibers. It is characterized in that the three layers are integrated by thermal adhesion to form a nonwoven fabric.

(Function) Urine excreted on the surface sheet quickly passes through the hydrophilic upper layer, passes through the rough water middle layer, reaches the hydrophilic lower layer, and is guided to the water absorbent body in contact with the lower layer for absorption. let Since the upper layer is made of hydrophilic heat-adhesive conjugate fibers, its surface is soft and, together with the hydrophilic nature of the fibers, improves its compatibility with the skin. Since the intermediate layer contains non-adhesive fibers, it can provide sufficient volume, and its rough water properties prevent liquid from penetrating from the water absorbent and from seeping onto the surface. Furthermore, since the lower layer is made of hydrophilic fibers, the moving liquid can be quickly transferred to the water absorbent body that comes into contact with it. In the upper, middle and lower three layers, the heat-adhesive composite fibers contained in each layer are thermally bonded to each other near the boundaries of each layer, so there is no risk of interlayer delamination, and the middle layer contains non-thermally-adhesive fibers. Since it is included, the volume of the layer is increased and it becomes bulky.

(Effects of the invention) According to this invention, it has good compatibility with the skin, quickly moves urine excreted on the surface to the water absorbent body, and prevents liquid from seeping to the surface of the water absorbent body. As a result, it is possible to provide a top sheet that is extremely easy to wear, has a smooth feeling, and does not feel sticky or uncomfortable on the skin. In addition, the upper, middle, and lower layers are bonded with heat-adhesive conjugate fibers to prevent delamination at the interface between the layers, so it is possible to provide a surface sheet with sufficient strength, and the middle layer is included therein. Since the non-thermally bondable fibers provide volume and bulk, it is possible to effectively prevent liquid from seeping out from the water absorbent body.

(Embodiments) Preferred embodiments of this invention will be described below with reference to the drawings. In the figure, 1 shows a disposable diaper to which a water absorbent body according to this invention is applied,
As is conventionally known, it has a length and width suitable for being attached to the crotch of an infant, and has fastener tapes 2 on both sides of the back.

The diaper 1 is constructed by sandwiching a water absorbent body 5 between a water-permeable top sheet 3 and a water-impermeable back sheet 4, and joining the side edges of the top sheet 3 and back sheet 4.
A plurality of elastic rubbers 6 are fixed to either the top sheet 3 or the back sheet 4, or both, and are arranged on both sides of the water absorbent body 5. Gears 7 that can be expanded and contracted freely
form.

As shown in FIGS. 3 and 5, the water permeable top sheet 3 is made of a laminate of three layers of nonwoven fabric, with an upper layer 8 in contact with the skin and a lower layer 9 adjacent to the water absorbent body 5 inside.
It is made of a nonwoven fabric made only of heat-adhesive composite fibers 11 consisting of high and low melting point components 12 and 13. The thermoadhesive composite fibers 11 are, for example, concentric fibers in which the outer periphery of polypropylene as the high-melting point component 12 is covered with polyethylene as the low-melting point component 13, and when heated, the low-melting point component 13 melts and forms adjacent fibers. Glue with. The nonwoven fabrics of both the upper and lower layers 8, 7 are subjected to hydrophilic treatment in the form of fibers, and have desired hydrophilic properties.

The intermediate layer 10 located between the upper and lower layers 8 and 9 is
It is made of a non-woven fabric in which the heat-adhesive conjugate fibers 11 and other non-thermally-adhesive fibers 14 are mixed, and when heated, the heat-adhesive conjugate fibers 11 in the intermediate layer 10 are thermally fused to each other and are adjacent to each other. It is thermally fused to the heat-adhesive composite fibers 11 of both the upper and lower layers 8 and 9 to be integrated as a whole. The other fibers 14 in the intermediate layer 10 are made of fibers that do not heat-seal with the heat-adhesive conjugate fibers 11 during heat-sealing, such as polypropylene. middle layer 10
It is preferable that the material be coarse water-based and as bulky as possible to prevent wet back. For this reason, if the amount of other fibers 14 is increased by setting the other fibers 14 to 80% and the heat-adhesive composite fiber 11 to 20%, and if the heat-adhesive composite fiber 11 is 2 deniers, then a thicker 3-denier fiber is used. Use.
Further, it is preferable that the top sheet 3 is light; for example, the upper and lower layers 8 and 9 have a weight of 7 g/m ² , and the middle layer 10 has a weight of 16 g/m 2 .
30g/m ² is appropriate ^.

In addition, in the case of diapers for infants under 12 months who have a small amount of urine, the lower layer 9 is omitted and the upper layer 8 and middle layer 1 are used.
The top sheet 3 may be composed of only 0.

Urine excreted onto the topsheet 3 quickly passes through the topsheet 3 and reaches the water absorbent body 5 adjacent to the topsheet 3. Due to the presence of the hydrophilic lower layer 9 located inside the top sheet 3, the moisture that has migrated is quickly transferred to the water absorbent body 5, and at the same time, the rough water intermediate layer 10 allows moisture to return to the surface well. to prevent. In this way, the upper surface of the top sheet 3 is low in moisture and can provide a smooth feeling to the skin.

The back sheet 4 is for preventing moisture from leaking to the back surface of the diaper, and is made of a synthetic rubber or polyethylene film with high tear strength.

The water absorbent body 5 has two matte-like crushed pulp layers 1
5, 16, and a super absorbent polymer layer 17 sandwiched between the pulverized pulp layers 15, 16 in a sandwich pattern.
Consisting of The pulp and superabsorbent polymer can be appropriately selected from those conventionally used in this type of product, and are not particularly limited. The upper pulp layer 15 adjacent to the topsheet 3 is embossed and integrated into a pressed part and a non-pressed part, together with the water absorbent body 18 laminated on its upper surface. The pressed part formed by the embossing process includes a central embossed line 19 that extends along the longitudinal direction of the central part of the water absorbent body 5 and side embossed lines that extend parallel to the central embossed line 19 on both sides of the water absorbent body 5. 20 and a horizontal embossed line 21 extending in the width direction of the water absorbent body 5 between the embossed lines 19 and 20. The upper pulp layer 15 is permanently compressed at the embossed line portion, and the pulp fibers become dense.
The capillary phenomenon becomes larger and the fluidity of water becomes higher than in the non-pressed area. As a result, the moisture excreted into the upper pulp layer 15 quickly moves to the lower superabsorbent polymer layer 17 at the embossed line portion, and also moves horizontally along the embossed line.

A plurality of horizontal embossed lines 21 are formed at equal intervals in the non-pressed part between the central embossed line 19 and the side embossed lines 20, and are formed at 45 degrees with respect to the central embossed line 19.
formed at an angle of The horizontal embossed lines 21 and the central embossed lines 19 are formed close to each other, so that moisture can quickly migrate from the central embossed lines 19 to the horizontal embossed lines 21. Further, the distance between the horizontal embossed line 21 and the side embossed line 20 is formed to be slightly wider than that between the lateral embossed line 21 and the center embossed line 19, and the distance between the lateral embossed line 21 and the side embossed line 2
This suppresses the migration of moisture to 0. Note that if the distance between the horizontal embossed lines 21 and the center embossed line 19 becomes too close, the pulp layer 15 will become hard and the wearing feeling will be poor, so the distance should be set appropriately.

In this way, the water excreted in the center of the water absorbent body 5 moves vertically at the center embossed line 19 and is absorbed into the super absorbent polymer layer 17, and at the same time moves along the central embossed line 19 along the longitudinal direction of the water absorbent body 5. move horizontally in the direction and spread. The moisture that has moved along the central embossed line diffuses into the non-pressed parts of the pulp layer, and at the same time moves to the horizontal embossed line 21 adjacent to the central embossed line 19.
1 in the width direction of the water absorbent body 5. In this way, the water excreted into the center of the water absorbent body 5 is diffused into an elliptical shape extending along the longitudinal direction of the water absorbent body 5.
It is widely diffused throughout the water absorbent body 5. When the moisture diffusion efficiency of the water absorbent body 5 of the present invention was compared with that of a water absorbent body without embossed lines, as shown in FIG. It showed the above-mentioned diffusivity, and the diffusivity was particularly good within 30 minutes after dropping water.

When the moisture diffused in the width direction of the water absorbent body 5 along the horizontal embossed lines 21 reaches the side embossed lines 20, it moves in the longitudinal direction of the water absorbent body 5 along the side embossed lines 20. leakage from the side edges of the diaper is suppressed, and water leakage from the sides of the diaper is prevented.

The horizontal embossed line 21 is the central embossed line 1 shown in the figure.
Although it may be formed perpendicularly to 9 rather than diagonally, it is preferable to form it diagonally in consideration of improving the fit of the diaper and dispersing moisture in an elliptical shape.

Further, the central embossed line 19, the horizontal embossed lines 21, and the side embossed lines 20 are not limited to the shapes shown in FIG. 6, but may be formed in various shapes shown in FIGS. 9 to 12.

The lower surface of the lower pulp 16 is preferably embossed in a lattice shape as shown in FIG. 7 in order to increase the strength of the entire water absorbent body 5 and in consideration of the mobility of water in the lower pulp 16.

To ensure good contact with the crotch area when worn,
As shown in Fig. 1, it is common practice to form a diaper with a slightly hollowed-out shape 21 on both sides, but as shown in Figs. It is also possible to attach the diaper by drawing the side portions of the diaper in a dotted manner and hollowing out the center portion of the side line of the diaper. With this structure, the diaper can be formed into a rectangular shape as shown in FIG. 13, and the shapes of the top sheet 3 and the back sheet 4 are simpler than those shown in FIG. 1, which simplifies manufacturing. It has the advantage of being

[Brief explanation of the drawing]

Figure 1 is a plan view of the diaper according to this invention, Figure 2
The figure is a perspective view of the same, Figure 3 is a sectional view, Figure 4 is a plan view of the top sheet, Figure 5 is an enlarged sectional view of the same part, Figure 6 is a plan view of the water absorbent body, and Figure 7 is the back side of the same. Figure, 8th
Figures 9-12 are diagrams showing the diffusion effect of the water-absorbing body, Figures 9-12 are diagrams showing modifications of the embossing formed on the plane of the water-absorbing body, and Figures 13-14 are planes showing one modification of the diaper according to this invention. FIG. 15 is a perspective view of the same. 1... Diaper, 2... Fastener tape, 3...
...Top sheet, 4...Back sheet, 5...Water absorber, 6...Elastic rubber, 7...Gears, 8...Upper layer, 9...Lower layer, 10...Middle layer, 11...Thermoadhesive composite Fiber, 12... High melting point component, 13... Low melting point component, 14... Other non-thermally adhesive fiber, 1
5, 16... Pulp layer, 17... Super absorbent polymer layer, 18... Water absorbing paper, 19... Center embossed line, 20... Side embossed line, 21... Lateral embossed line, 22... Gouged part .

Claims (1)

[Scope of utility model registration request] The upper and lower layers consist only of heat-adhesive conjugate fibers, which are made by coating a high-melting point component with a low-melting-point component and subjected to hydrophilic treatment. 1. A top sheet for a disposable diaper, comprising an intermediate layer made of a mixture with other heat-adhesive fibers, and the three layers are integrated into a nonwoven fabric by thermal adhesion of heat-adhesive conjugate fibers.