JP2880241B2 - Top sheet for wearable absorbent articles - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a topsheet for a wearable absorbent article, and more particularly to a plastic film topsheet suitable for use in napkins, disposable diapers, incontinence pads and the like. About.

(Prior Art) In an absorbent article worn by a person, in particular, a napkin, a disposable diaper or the like as a disposable absorbent article, it is generally used as a liquid-permeable topsheet, a liquid-impermeable backsheet and a liquid-impermeable backsheet. The top sheet is made of a hydrophobic plastic film, which is constituted by an intervening absorber and realizes a dry touch feeling at the time of use.
A method is widely used in which an aperture having an appropriate shape and an aperture ratio is provided to impart liquid permeability. Although such a topsheet is used in direct contact with human skin, such a topsheet has a unique feel to a plastic film, such as a "sticky" feeling, a "slimy" feeling, and a visual feeling. The problem is that the luster is difficult to handle, and it is difficult for people accustomed to wearing textiles to wear it on the skin.

In addition, various types of apertures for imparting liquid permeability to the hydrophobic plastic film have been proposed for the shape, but in any stage, when the absorbent article is actually worn, the pressure contact force and pressure contact with the human body are made. There is a problem that, with bending or the like for adapting to a part, waving or wrinkles generated in the film distorts or closes the aperture, thereby reducing the aperture area ratio initially applied to the film.

Among these problems, various attempts have been made to improve the feel of a plastic film. For example, an attempt has been made to give a fibrous feel by applying an embossing process or the like to the surface of a plastic to suppress the glossiness (for example, see Japanese Patent Application Laid-Open No. Sho 56 (1988)). -9401) and other technologies commonly used to make a stretched film by mixing a plastic material with an inorganic filler to make the surface of the film matte and to make the feel different from the plastic film. In each case, the film surface is provided with innumerable and minutely independent irregularities on the film surface, and the results have been commensurate.The technology has been applied to the apertured film for the top sheet of absorbent articles. I have. On the other hand, there is no method for preventing the distortion and clogging of the apertures of the apertured film and the accompanying reduction in the area ratio of the apertures and the reduction in liquid permeability.

(Problems to be Solved by the Invention) In a top sheet for a wearable absorbent article having an opening pattern, when a hydrophobic plastic film is used, a feeling peculiar to the plastic film, for example, a “sticky” feeling, a “slick” It is desirable to improve the feel and visual luster to make the feel and feel more familiar to humans, while at the same time the apertures in the aperture pattern are less distorted and less plugged, and therefore the area ratio of the aperture when worn However, there is no known technique that satisfies these requirements at the same time. An object of the present invention is to provide a topsheet for a wearable absorbent article having an aperture pattern that is effective in improving the feel inherent in such a plastic film and at the same time reducing distortion of the aperture. .

(Means for Solving the Problems) The gist of the present invention to achieve the above object is to provide a top sheet for a wearable absorbent article comprising a hydrophobic plastic film and having a large number of liquid-permeable openings. Each of the openings is a hollow rib that is formed by an annular wall portion protruding upward leaving a peripheral portion having an appropriate width extending in the radial direction and a top surface portion connected to the upper end thereof, and is opened on the back surface side of the top sheet. The topsheet is characterized in that the topsheet is surrounded.

(Function and Effect) The top sheet made of the hydrophobic plastic film of the present invention is provided with liquid permeability by providing an opening pattern, and by projecting ribs between the openings, the top sheet is exposed to the skin. The close contact, while reducing the contact area in an intermittent form via the ribs, also has the effect of visually reducing the feeling of plastic film, furthermore, the ribs prevent changes in the opening edge of the film,
Distortion and blockage of the apertures are reduced, thus preventing a reduction in the area ratio of the apertures when worn. Also, since the ribs are hollow, the entire top sheet has cushioning properties,
Improves skin contact feeling.

Furthermore, in the case of having a tapered liquid guide tube, the introduction of the body fluid is excellent, and the backflow of the body fluid is effectively prevented.

(Example 1) Fig. 1 shows a sanitary napkin 1 as an example of a wearable absorbent article according to the present invention, which includes a liquid-permeable top sheet 2A, a liquid-impermeable back sheet 3, and The top sheet 2A has an opening 5
80 μm thick polyethylene film provided with liquid permeability by the above, backsheet 3 is 100 μm thick polyethylene film, and absorber 4 is 10% by weight of superabsorbent polymer particles.
It is composed of crushed pulp.

FIG. 2 and FIG. 3 are a plan view and a cross-sectional view showing an open state of the top sheet 2A. The openings 5 are provided on the surface of the top sheet 2A, are substantially circular openings having an opening area of about 1 mm and have a hole diameter D, and a large number of openings 5 are formed in the entire top sheet 2A.
Are substantially uniformly distributed, and have an opening pattern and an opening ratio of 45%. A hollow rib 7 opening from the front surface of the top sheet 2A on the back surface thereof is located between the openings 5 at a distance L,
An annular wall 7a protruding upward at a height H of about 0.3 mm, leaving a radially extending peripheral edge 6 having a width to keep L '= about 0.2 mm.
And a top surface portion 7b connected to the upper end thereof, and surrounds each opening 5. In the cross section of FIG. 3, the width (W) of the rib is about 0.72 mm. Such a top sheet 2A can be obtained, for example, by using a process described later with reference to FIG.

When the top sheet 2A in the illustrated example is used for the napkin 1, fine irregularities are formed on the surface of the top sheet 2A by the ribs 7, and the "sticky" feeling, "slimy" feeling and gloss inherent to the plastic film. When the napkin 1 is worn, the overall surface of the film is less likely to adhere to the skin, and the top sheet 2A abuts intermittently via the ribs 7, so that the top sheet 2A abuts on the skin. The effect of improving the feel as a plastic film when repelled is remarkable. Moreover, since the vicinity of the periphery of the opening 5 has a rib structure,
Even if the napkin 1 is deformed, the opening 5 is distorted and the closing deformation is suppressed, and the effect of suppressing a decrease in the opening area ratio is exhibited.

(Example 2) Figs. 4 and 5 are a plan view and a cross-sectional view of a top sheet 2B having an opening pattern as yet another example.
The top sheet 2B is made of a polyethylene film having a thickness of 50 μm, and has a substantially circular tapered liquid guiding pipe portion 8 having a depth H ′ extending from the film surface toward the absorber 4 to 1.5 mm. The inside of the liquid pipe section 8 defines an opening 5,
The hole diameter (D) is determined on the film surface as shown in the figure, and is about 1.2 mm. Opening 5
An annular wall portion 7a having a height H of about 0.2 mm protruding upward from a peripheral edge of each opening 5 except for a peripheral portion 6 having a width for maintaining the distances L and L 'and extending in a radial direction. And the width W connected to its upper end
And a rib 7 formed by a top surface portion 7b of about 0.25 mm protrudes. The liquid guide tube portion 8 extends to the absorber 4 side continuously to the inner peripheral edge of the peripheral edge portion 6. The distances L and L 'can be independent of each other, except that both need to be at least 0.1 mm. Also in such a top sheet 2B, the rib 7 has the same effect as the embodiment in FIG. 2 and FIG. 3, but the top sheet 2B of this embodiment has only the height H ′ of the tapered liquid guide tube 8, The purpose is to isolate the film surface from the absorber 4 and use it, and it is required that the shape of the tapered liquid guide tube portion 8 is not distorted or collapsed as much as possible even when deformed when a napkin is worn. Therefore, in this case, the presence of the ribs 7 to reduce the deformation of the opening 5 and the tapered liquid guide tube portion 8 such as distortion and crushing is extremely convenient in maintaining the performance of the top sheet 2B. .

(Embodiment 3) FIGS. 6 and 7 show still another embodiment. FIG. 6 shows a top portion 9 of a rib 7 in a top sheet 2C of the present invention.
FIG. 7 illustrates an example of a process of obtaining the top sheet 2C from the raw film 20 together with a process of applying the coating 10. FIG. The coating 10 is for further modifying the feel, visual sensation, water repellency, hydrophobicity, etc. of the plastic film used for the top sheet 2C, such as acrylic resin paint, paint such as urethane resin paint, printing ink, It is obtained by gravure coating a coating material such as a surfactant. Paints, inks, and the like can be subjected to appropriate coloring, opacity, matting, and other treatments to improve the touch and visual effects of the top sheet 2C. The coating 10 is selectively applied only to the top 9 of the rib 7, and the top sheet
The touch when the 2C intermittently contacts the skin via the rib 7 can be replaced with the touch of the coating 10. The purpose of applying the coating 10 only on the top portion 9 is not only for the purpose of economical consumption of the coating material but also for improving the feel and the visual feeling, when the napkin is worn by intermittently contacting the skin when wearing the napkin. Because it is enough.

In FIG. 7, in the step of obtaining the top sheet 2C, the raw film 20 is supplied to the forming drum 21, and at a position where the suction portion 22 of the drum 21 faces the hot air jet device 23, the film 20 is softened by hot air, The garnet roll 24 in which a large number of aperture needles are arranged on the circumference while cooling the film 20 while cooling the film 20 is formed by applying suction to allow the mold to be provided with a predetermined rib shape provided on the drum 21. In the coating zone 25, the top of the rib is selectively coated with the coating paint 26 via the coating roller 27, and set in a low temperature range without damaging the shape of the formed rib. Heater
The paint 26 is dried and solidified by 28, and the top sheet 2C
And The top sheet 2C is used after being appropriately wound, cut, and the like before the absorbent article production line. From the viewpoints of manufacturing and assembling accuracy of the rib-shaped forming die provided on the drum 21 and the garnet roll 24, it is preferable that L and L 'in the second embodiment be 0.1 mm or more.

[Brief description of the drawings]

FIG. 1 is a perspective view of a sanitary napkin showing a part of the top sheet according to the present invention cut away, FIGS. 2 and 3 are plan and sectional views of the top sheet of FIG. FIG. 5 and FIG. 5 are a plan view and a sectional view of a top sheet according to another embodiment, FIG. 6 is a sectional view of a top sheet according to still another embodiment, and FIG. It is a schematic diagram showing a manufacturing process. DESCRIPTION OF SYMBOLS 1 ... Absorbent article 2A, 2B, 2C ... Top sheet 5 ... Opening 6 ... Peripheral part 7 ... Rib 7a ... Annular wall part 7b ... Top surface part 8 ... Tapered liquid guide tube part

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-61-56645 (JP, A) JP-A-56-49003 (JP, A) JP-A-1-292104 (JP, A) JP-A-2- 198551 (JP, A) JP-A-64-34365 (JP, A) JP-A-63-24944 (JP, A) JP-A-1-95920 (JP, U) JP-A-2-17126 (JP, U) JP-B-57-17081 (JP, B2) (58) Fields investigated (Int. Cl. ⁶ , DB name) A61F 5 / 44,13 / 15,13 / 54

Claims (2)

(57) [Claims] 1. A top sheet for a wearable absorbent article comprising a hydrophobic plastic film and having a large number of liquid-permeable openings, wherein each of the openings has a peripheral portion extending in its radial direction and having an appropriate width. The topsheet, wherein the topsheet is surrounded by hollow ribs formed of an annular wall protruding to the top and a top surface connected to the upper end thereof, and opened on the back surface side of the topsheet. 2. The top sheet according to claim 1, wherein a tapered liquid guide tube extends downward from an inner peripheral edge of a peripheral portion of the opening.