JP2812340B2 - 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 can eliminate the above-mentioned drawbacks of the prior art by forming a liquid guide tube having an 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, the present invention provides a liquid guide tube having an upper surface and a lower surface opening and arranged to extend downward, and an upper opening edge of these liquid guide tubes. It is assumed that the surface sheet of the absorbent article has a continuous skin contact area.

In the present invention, on the premise, a nonwoven fabric is formed by fusing thermoplastic fibers, and the liquid guide tube is formed from a part of the nonwoven fabric, and a fiber fluff is formed at an opening end of a lower surface of the liquid guide tube.

In a preferred embodiment, the skin contact area is provided with air permeability (first mode) or is impermeable (second mode).
In any of the first and second aspects, the peripheral wall of the liquid guide tube is provided with air permeability and liquid permeability.

(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 is absorbed into the article through each liquid guide tube. In this case, the liquid guide tube, particularly the fiber fluff located at the open end of the lower surface thereof, comes into contact with the core to exert an excellent capillary action, thereby effectively transferring the body fluid to the core (claims 1 to 4).

Unlike the plastic film, the top surface of the topsheet is in contact with the wearer's skin without adhering to the wearer's skin to give a cloth-like feel, and at the same time, is ventilated between the skin and hardly interferes with skin breathing. 1 to 4).

Since the peripheral wall of the liquid guide tube is provided with air permeability, the inside of the article can be ventilated through the peripheral wall. This ventilation is not hindered even when the liquid guide tube is deformed or closed by body pressure (claim 4).

Since the skin contact area is also provided with air permeability, air permeability with the inside of the article is further improved (claim 2).

By providing the skin contact area with air-impermeable property, 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 3).

By imparting liquid permeability to the peripheral wall of the liquid guide tube, similar to the ventilation, even if the liquid guide tube is deformed or closed by body pressure, the liquid guide function through the liquid guide tube is performed. There is no hindrance (claim 4).

(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 has a surface sheet 11 on which a liquid guide tube is formed.
And a liquid-impermeable backing sheet 2 and a liquid-absorbing 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 tube 13. Top sheet 11,
A nonwoven fabric is used as a base material, and includes a skin contact area (non-opening area or continuous rib area) 12 and a number of liquid guide tubes 13. Liquid guide tube 13
Has an upper surface opening 13a and a lower surface opening 13b, and extends downward from the periphery of the upper surface opening 13a to form an array. The fluff 14 is formed by letting it out. The periphery of the upper surface opening 13a is continuous with the skin contact area 12. The diameter of the liquid guide tube 13 is
The lower surface 13b is formed to have a taper gradually reduced from a.

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. Depending on the basis weight and density of the non-woven fabric, or by means of heat-compression treatment after the formation of the non-woven fabric, any of air permeability and air permeability can be imparted. 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 upper surface opening 13a, the diameter is 0.2 to 2 mm, especially 0.7 to 1.3 mm, and the total aperture ratio of each is 20 to 70%.
The height (length) of the liquid guide tube 13 is set to 0.5 to 5 mm to obtain a high liquid guide effect from the upper surface of the liquid guide tube 13 to its lower surface, while the body fluid from the lower surface to the upper surface is obtained. From the viewpoint of suppressing outflow of water.

4 to 6 show another embodiment of the liquid guide tube 13,
FIG. 4 is a cross-sectional view corresponding to FIG. The liquid guide tube 13 shown in FIG.
Is the same as that shown in FIG. 3 in that its diameter is gradually reduced from the upper surface opening 13a to the lower surface opening 13b, but the lower surface opening 13b is formed much smaller than that shown in FIG. Although not shown, in some cases, the lower surface opening 13b
May be almost closed. 5th liquid guide tube
13 has a substantially parallel wall surface and upper and lower openings 13
The diameters of a and 13b are formed substantially the same. The liquid guide tube 13 shown in FIG. 6 is formed in a taper whose diameter gradually increases from the upper surface opening 13a to the lower surface opening 13b.

The thickness of the peripheral wall of each illustrated liquid guide tube 13 is not thinner than that of the skin contact area 12, and the peripheral wall of the liquid guide tube 13 is provided with a plurality of folds substantially in the extending direction of the liquid guide tube 13. There is a bottom opening
The periphery of 13b is irregularly formed. The liquid guide tube 13 has a fiber density on the peripheral wall thereof lower than that of the skin contact region 12, thereby imparting gas permeability and liquid permeability to the liquid guide tube 13. Then, even when the liquid guide tube 13 is deformed or closed by body pressure, it is possible to introduce the body fluid from the upper surface to the lower surface. In order to enhance the gas permeability and liquid permeability, the fiber gap on the peripheral wall of the liquid guide tube 13 may be increased.

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 having the same shape, size, and arrangement as the openings 13a to form a nonwoven fabric. At the same time, a negative pressure 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 negative pressure is applied is drawn downward by suction. I do.
In this case, the suction portion of the nonwoven fabric hangs down in a tubular shape having an upper surface opening, and the lower surface of the tubular portion is broken and the fiber is opened in a loosened state, that is, upper and lower surface openings 13a, 13b and fiber fluff are obtained. Liquid conduit 1 with 14
3 is formed. The treatment for forming the liquid guide tube 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 portion of the nonwoven fabric downward, the fiber density of the peripheral wall of the liquid guide tube 13 thus formed can be made lower than that of the skin contact area 12. The peripheral wall of the liquid guide tube 13 having a reduced fiber density has excellent air permeability and also has liquid permeability. Depending on the suction force and the basis weight, density and fineness of the nonwoven fabric, the fiber gap in the peripheral wall of the liquid guide tube 13 can be increased.

Forming the above-described state in the liquid guide tube 13 is achieved through the peripheral wall of the liquid guide tube 13 when the nonwoven fabric maintains an integral fiber accumulation form, that is, is formed into a film, and does not have air permeability. This is effective in imparting air permeability to the topsheet 11.
Even if the fibers of the nonwoven fabric are oriented and fused at random, at least a part of the fibers on the peripheral wall of the liquid guide tube 13 is drawn in the suction direction (extending direction of the liquid guide tube 13) by the suction force.
, So that the capillary action in that direction on the peripheral wall becomes stronger. This is effective in promoting the introduction of bodily fluid from the upper surface to the lower surface of the liquid guide tube 13.

As illustrated in FIG. 7, the topsheet 11 is
The lower opening 13b is used to cover the core 3 by facing it. The liquid guide tube 13 may be buried in the core 3 as appropriate.

(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 or air permeability and liquid permeability at all times during 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.

In particular, the fiber fluff located at the open end of the lower surface of the liquid guide tube comes into contact with the core and exerts an excellent capillary action, effectively transferring the body fluid to the core of the article. Can be prevented from remaining and giving a feeling of wetness to the skin, in other words, a so-called dry touch feeling can be improved.

[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 tube, 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 guide tube, 13a: Upper surface opening 13b: Lower surface opening, 14: Fiber fluff

──────────────────────────────────────────────────続 き Continuation of the front page (72) Inventor Tsutomu Kido 883-1 Tsumatori-cho, Kawanoe-shi, Ehime (56) References JP-A-4-58951 (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 (4)

(57) [Claims] 1. A surface sheet for an absorbent article having a liquid guide tube having upper and lower openings and extending downward and arranged, and a skin contact area continuous with the periphery of the upper surface opening of the liquid guide tube. Wherein the thermoplastic fibers are fused to form a non-woven fabric, and the liquid guide tube is formed from a part of the non-woven fabric, and a fiber fluff is formed at an open end of a lower surface of the liquid guide tube. The topsheet. 2. The surface sheet according to claim 1, wherein the skin contact area is provided with air permeability. 3. The surface sheet according to claim 1, wherein the skin contact area is provided with air permeability. 4. The surface sheet according to claim 2, wherein the peripheral wall of the liquid guide tube is provided with air permeability and liquid permeability.