JP2809491B2 - Surface sheet for absorbent articles - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a surface sheet of an absorbent article, and more particularly, to a body fluid such as a sanitary napkin, a sanitary tampon, and a disposable diaper which is coated with an absorbent core. The present invention relates to a topsheet for constituting an absorbent article.

(Prior art, problems to be solved by the invention) Conventionally, as a surface sheet of this kind, in order to reduce the wet feeling of bodily fluid on the wearer's skin and relatively increase the permeability of bodily fluid, There is known a hydrophobic nonwoven fabric in which openings of a given pattern are arranged and formed. But,
The apertures in the topsheet are planar in structure, with the lower surface of the skin contact area extending between each of the apertures directly contacting the upper surface of the absorbent core. Therefore, when body pressure is applied to the core that has absorbed the body fluid, or when the core expands due to the absorption of the body fluid and this is pressed against the topsheet, the body fluid passes from the core to the top surface of the topsheet through the opening. Oozing, failing to achieve its intended purpose.

On the other hand, as a topsheet intended to remove defects of the topsheet, etc., a liquid guide is formed by arranging openings of a given pattern in a plastic film and extending downward from the periphery of these openings. One with a tube is known. This topsheet can tentatively achieve the object of reducing the contact area of the wearer with the skin and the feeling of body fluid wetting on the skin and relatively increasing the permeability of the body fluid. However, when body pressure is applied to the core that has absorbed body fluid, or when the core absorbs body fluid and expands, the core comes into pressure contact with the topsheet, thereby deforming and closing the liquid guide tube. Loss air permeability by the liquid guide tube. As a result, the surface sheet and the skin of the wearer become stuffy and cause dermatitis on the skin, such as rash, swelling,
Give itching. Of course, when the liquid guide tube is closed in this way, the liquid guide tube loses its function, and the body fluid excreted on the upper surface of the topsheet after the blockage cannot be introduced into the inside. Further, since the surface sheet still completely maintains the properties of the film itself, it cannot be said that the texture is better than that of the cloth.

The present invention makes it possible to eliminate the above-mentioned disadvantages of the prior art by forming a liquid-guiding recess having excellent capillary action from a part of a nonwoven fabric obtained by fusing thermoplastic fibers as a base material. It is intended to provide a topsheet.

(Means for Solving the Problems) In order to achieve the above object, a topsheet according to the present invention is made of a nonwoven fabric to which thermoplastic fibers are fused. In this nonwoven fabric, a liquid guide recess having an opening and a bottom surface and extending downward is arranged, and a skin contact area continuous with the periphery of the opening of the liquid guide recess is formed. A plurality of liquid guide tears are provided on the bottom surface and the side surface of the liquid guide recess.

In a preferred embodiment, the skin contact area is either impermeable or air permeable.

(Function) The topsheet according to the present invention having the above configuration is used to form the surface of an article having a liquid-absorbent core inside. In this use state, bodily fluid flows into each of the liquid guide recesses and is absorbed into the interior of the article through these liquid flow gaps (claims 1 to 3).

Unlike the plastic film, the top surface of the topsheet makes contact with the wearer's skin without adhering to the skin and gives a cloth-like feel, while allowing the skin to ventilate and hardly hinder skin breathing. 1 to 3).

By providing the skin contact area with air permeability, there is no ventilation in the skin contact area, but the body fluid does not exude from the lower surface to the upper surface of the skin contact area under any pressure (claim 2).

Ventilation with the inside of the article can be achieved through the breach in the liquid guide recess. This ventilation is not hindered even when the liquid guide recess is deformed by body pressure (claims 1 to 3).

By providing the skin contact area with air permeability, air permeability with the inside of the article is further improved (claim 3).

(Example) An example of a topsheet according to the present invention will be described below with reference to the drawings.

FIG. 1 is a perspective view of a partially cut-off sanitary napkin as an example using a topsheet according to the present invention. The napkin 1 is a surface sheet having a liquid-guiding recess described later.
11, an impermeable back sheet 2 and an absorbent core 3 interposed therebetween.

FIG. 2 is a schematic perspective view of a part of the topsheet 11, and FIG. 3 is a schematic sectional view of the liquid guide recess 13. Surface sheet 11
Is composed of a nonwoven fabric as a base material and includes a skin contact area (non-opening area or continuous rib area) 12 and a large number of liquid guiding recesses 13. The liquid guide recesses 13 are arranged with an opening 13a and a bottom surface 13b, and have a liquid guide gap 14 on the bottom surface 13b and the side surface 13c. The periphery of the opening 13a is continuous with the skin contact area 12. The liquid guide recess 13 is formed in a tapered shape whose diameter is gradually reduced from the opening 13a to the bottom surface 13b.

The nonwoven fabric as the base material of the topsheet 11 is obtained by fusing thermoplastic fibers to give a cloth form. The nonwoven fabric may be provided with air permeability or may be provided with air permeability. The most preferable of such nonwoven fabrics is obtained by a conventionally known means for producing a meltblown nonwoven fabric. Either imperviousness or air permeability can be imparted depending on the basis weight and density of the nonwoven fabric, or by means of heat compression after the formation of the nonwoven fabric. As this nonwoven fabric, generally, thermoplastic (hydrophobic) fibers such as olefins, polyesters, nylons, and EVA with a fineness of 0.01 to 1 d are fused, and the basis weight is 10 to 50 g / m ² , above all 20-35 g /
None m ^2, the use of what are no density to 0.03~0.5g / cm ³ is preferable for obtaining a good touch, required strength.

In the case of a breathable nonwoven fabric, the air permeability according to JIS.
500 cc / cm ² / sec, water resistance according to JIS.L.1092 10-2
A diameter of 50 mm is preferable in order to obtain required air permeability in the skin contact area 12 and to prevent backflow of body fluid from the lower surface of the skin contact area 12 to the upper surface thereof. By the way, conventionally,
The nonwoven fabric used as the topsheet of the absorbent article has an air permeability of 500 cc / cm ² / sec or more and is excellent in air permeability, but has almost no water pressure resistance.

Regarding the opening 13a, the diameter is 0.2-2 mm, especially 0.7
1.3 mm, the total aperture ratio of each is 20-70%, and the height (length) of the liquid guide recess 13 is 0.5-5 mm. This is preferable in that a high liquid-conducting effect is obtained while suppressing outflow of bodily fluids from the lower surface to the upper surface.

4 to 6 show another embodiment of the liquid guide recess 13, and are sectional views corresponding to FIG. The liquid guide recess 13 shown in FIG. 4 is the same as that shown in FIG. 3 in that the diameter thereof is gradually reduced from the opening 13a to the bottom surface 13b.
Are formed much smaller than those shown in FIG. The liquid guide recess 13 shown in FIG. 5 is formed so that its side surface 13c is substantially parallel and the diameter of the opening 13a and the bottom surface 13b are substantially the same. The liquid guide recess 13 shown in FIG.
It is formed in a taper gradually increasing from a to the bottom surface 13b. The thickness of the bottom surface 13b and the side surface 13c of each illustrated liquid guide recess 13 is not thinner than that of the skin contact area 12, and the side surface 13c is provided with a plurality of folds substantially in the extending direction of the liquid guide recess 13. is there. The liquid guide recess 13 has a lower fiber density at the bottom surface 13b and side surfaces 13c than at the skin contact area 12.

The topsheet 11 can be manufactured in this way, for example. The molten polymer is discharged from the melt blower, turned into ultrafine fibers by a high-speed high-temperature air flow, and deposited on the upper surface of a conveyor having a forming element group having the same shape, size, and arrangement as the liquid guide recesses 13 to form a nonwoven fabric. At the same time, suction is applied to a given area of the non-woven fabric where the fibers are in a softened state by a suction arranged on the lower surface of the conveyor, and the non-woven fabric portion located in the group of openings of the conveyor in the area where the pressure is applied is drawn downward by suction. In this way, the liquid-guiding recess 13 in which the extended portion of the nonwoven fabric hangs in a tubular shape having an opening 13a and a bottom surface 13b.
Is formed. The treatment for forming the liquid guide recess 13 may be performed by forming a nonwoven fabric and treating it with a heating roll (including an embossing roll) or ultrasonic waves, if necessary.
It can be performed after the surface is further smoothed and the fusion ratio and strength are increased.

As described above, by stretching the relevant portion of the nonwoven fabric, the bottom surface 13b and the side surface 13c of the liquid guide recess 13 thus formed are formed.
The fiber density of the fabric becomes lower than that of the skin contact area 12, and these fabrics partially rupture to form crevices 14. Depending on the stretching ratio, the basis weight, the density, and the fineness of the nonwoven fabric, the tear 14 can be increased.

Forming the above-described state in the liquid guiding recess 13 imparts air permeability to the topsheet 11 when the nonwoven fabric maintains an integral fiber accumulation form, that is, is formed into a film and does not have air permeability. It is effective on the above. In addition, even if the fibers of the nonwoven fabric are randomly oriented and fused,
At least a part of the fiber on the side surface 13c of the liquid guiding recess 13 is oriented in the drawing direction (extending direction of the liquid guiding concave portion 13), and as a result, the capillary action in the direction on the side surface 13c becomes stronger. This is effective in promoting the introduction of bodily fluid from the upper surface to the lower surface of the liquid guide recess 13.

As illustrated in FIG. 7, the topsheet 11 is provided with a liquid guiding recess.
The bottom surface 13b of 13 is used to cover the core 3 by facing it. The liquid guide recess 13 may be appropriately filled in the core 3.

(Effect of the Invention) According to the topsheet according to the present invention having the above-described configuration and function, it is possible to maintain air permeability and liquid permeability at all times during the wearing of the article. Therefore, it is possible to prevent the surface sheet and the skin of the wearer from becoming stuffy and causing rash, irritability, itching or the like which causes skin diseases.

[Brief description of the drawings]

FIG. 1 is a sanitary napkin showing an example of an article to which the topsheet according to the present invention is to be used, FIG. 2 is a schematic perspective view of the topsheet, and FIG. FIG. 4 is a schematic longitudinal sectional view of a liquid guide recess, FIGS. 4 to 6 are views corresponding to FIG. 3, showing another embodiment, and FIG. 7 is a schematic partial enlarged sectional view of the article. It is. 11: Surface sheet, 12: Skin contact area 13: Liquid guiding recess, 13a: Opening 13b: Bottom, 13c: Side surface 14: Liquid guiding breach

──────────────────────────────────────────────────続 き Continuation of the front page (72) Inventor Tsutomu Kido 883-1 Tsumatoricho, Kawanoe-shi, Ehime (56) References JP-A-4-58950 (JP, A) JP-A-3-97458 (JP, A) JP-A-3-51355 (JP, A) (58) Fields investigated (Int. Cl. ⁶ , DB name) A61F 13/15

Claims (3)

(57) [Claims] 1. A liquid guide recess formed of a nonwoven fabric to which thermoplastic fibers are fused, having an opening and a bottom surface and extending downward and arranged in a row, and a skin contact continuous with the periphery of the opening of the liquid guide recess. A surface area of the absorbent article, wherein the surface sheet has a plurality of liquid crevices formed on the bottom surface and the side surface of the liquid conductive recess. 2. The surface sheet according to claim 1, wherein air permeability is imparted to the skin contact area. 3. The surface sheet according to claim 1, wherein the skin contact area is provided with air permeability.