JPH05285171A - Absorbent article using a hydrophilic porous sheet - Google Patents

Abstract

(57) [Abstract] [Purpose] To provide a porous sheet having extremely small stickiness on the surface, liquid remaining, and liquid spreading, and excellent liquid absorbing performance, and not causing discomfort to the skin. Providing absorbent articles such as disposable diapers and napkins. In an absorbent article comprising a liquid-permeable surface material, a liquid-impermeable back material, and an absorber provided between them, a porous material having a plurality of liquid-permeable openings as the surface material. A hydrophilic sheet is used, and a hydrophilic treatment is applied to the inner wall surface of the liquid permeation opening of the porous sheet or to the sheet surface on the absorber side together with the inner wall surface.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an absorbent article using a hydrophilic porous sheet, and more particularly, it is excellent as a surface material for paper diapers and sanitary napkins. The present invention relates to an absorbent article using a porous sheet.

[0002]

2. Description of the Related Art Conventionally, as a technique for imparting hydrophilicity to a polyolefin-based porous sheet, the following methods (1) to (4) are known. (1) A method of kneading a hydrophilizing agent into a hydrophobic resin. As this method, there is a method in which a surfactant is added to polyolefin, a perforated film is thermally formed using this material, and further corona discharge treatment is performed (Japanese Patent Publication No. 1-49381). (2) A method of attaching a hydrophilic low molecular weight compound (surfactant). As this method, a method of adhering a high-affinity fatty acid ester type nonionic surfactant to a polyolefin-based porous sheet (JP-A-63-6166) and a method of using polyglycerin fatty acid ester (JP-A-2 −
No. 216265). (3) A method of performing physical treatment such as plasma treatment or corona discharge treatment. There is a method in which oxygen is excited with high frequency energy to reduce the pressure, and the surface of the sheet-like material is carbonylated (Japanese Patent Publication No. 53-794). (4) Chemical treatment methods such as chemical treatment and solvent treatment.

[0003]

However, in the method (1), the amount of the surfactant added greatly affects the processability and the performance after bleed-out, and causes yellowing of the resin. With regard to (2), the adhesion of the adhesive to the surface of the polymer is poor, but the expected liquid permeability cannot be obtained, although it is simple. Further, even if a certain level of liquid permeability is obtained, sufficient durability cannot be obtained. (3) and (4) have the drawback that the hydrophilicity deteriorates over time. Furthermore, in the case of an absorbent article, by any method, since the entire surface of the polyolefin-based porous sheet is made hydrophilic, the absorption performance is improved, but the liquid residue increases on the surface contacting the skin. It becomes sticky and causes discomfort. Further, since the liquid spread becomes large, it looks bad and may lead to leakage. Therefore, the present invention, the stickiness on the surface,
It is an object of the present invention to provide an absorbent article using a porous sheet that has very little liquid remaining and liquid spreading and is excellent in liquid absorbing performance.

[0004]

The present invention provides an absorbent article comprising a liquid-permeable surface material, a liquid-impermeable back material, and an absorber provided therebetween, wherein the surface material is A porous sheet having a plurality of liquid permeation openings is used as the inner surface of the liquid permeation openings of the porous sheet, or the sheet surface on the absorber side together with the inner wall is subjected to a hydrophilic treatment. The above-mentioned object is achieved by providing an absorbent article using a characteristic porous sheet.

Hereinafter, an absorbent article using the porous sheet according to the present invention will be described in detail with reference to the drawings. FIG. 1 is a perspective view of an absorbent article according to the present invention, FIG. 2 is an explanatory view of a main part showing a hydrophilic treatment portion when a porous sheet used in FIG. 1 is produced, and FIGS. c) is an enlarged cross-sectional view of various preferable embodiments of the porous sheet used in the present invention.

As shown in FIG. 1, an absorbent article (sanitary napkin) 1 includes a liquid-permeable surface material 2, a liquid-impermeable back material 3, and an absorbent body 4 provided therebetween. It consists of Then, the surface material 2 is provided with a plurality of liquid permeation openings 1
And a hydrophilic sheet is applied to the inner wall surface 10A of the liquid permeation opening 10 of the porous sheet or to the sheet surface 2A on the absorber side together with the inner wall surface 10A. ing.

The porous sheet 2 is made of a sheet material such as a non-woven fabric or a film.
0 μm to 5 mm, particularly 500 μm to 2 mm is desirable.
In the case of a film, the thickness is 10 to 100 μm,
In particular, it is preferably 20 to 40 μm, and the openings 10 formed in the film or the like may three-dimensionally project to the absorber 4 side. In this case, the length of the inner wall surface 10A is 100 μm to 3 mm, In particular, the thickness is preferably 300 μm to 1 mm. Examples of the material of the porous sheet 2 include nylon, cellulose (pulp), polyolefin such as polyethylene and polypropylene, polyester, and the like, or a composite of these materials. A polyolefin resin is preferable, and polyethylene is particularly preferable in view of productivity and economy. The porous sheet 2 is shown in FIG.
It may be a laminate material of the non-woven fabric layer 6 and the film layer 7 as shown in (c).

Although the size of the diameter of the opening 10 of the porous sheet 2 is not limited, the radius is preferably 0.1 to 5.0 mm, more preferably the radius, considering the liquid absorbency, texture, tear strength, and impression. 0.5-2.0 mm is good. Further, as shown in FIG. 3B, the protrusion angles α and β of the aperture wall are
Is not particularly limited to 90 °, and the aperture 1
The shape of 0 is not particularly limited and may be a conventionally known shape such as a flared end or a flared end.

The inner wall surface 10A of the opening 10 is hydrophilically treated. Specifically, the surfactant 5 is attached to the inner wall surface 10. If the inner wall is a non-woven fabric, the adhesion amount is preferably 0.05 to 1.0 wt% with respect to the weight of the non-woven fabric,
More preferably, it is 0.1 to 0.4 wt%. If the wall of the aperture 10 is formed of a film, the coating amount of the inner wall surface 10A is preferably 0.01 to 0.5 g /
m ² , more preferably 0.05 to 0.15 g / m ² . If the coating amount is less than the values shown here, the hydrophilicity is not sufficiently exerted, and if the coating amount is too large, it bleeds to the surface during coating and compresses when worn against skin. Etc., the surface becomes sticky and the effect of the present invention is halved. Further, in the porous sheet 2 of FIGS. 3A to 3C, only the inner wall surface 10A of the opening 10 is hydrophilically treated, but as described later (FIG. 5), the inner wall surface 10A of the opening 10 is formed. Also, the one surface 2A (the surface facing the absorber or the back surface side) where the aperture wall projects may be hydrophilically treated.

The surface-active agent 5 is attached to the above-mentioned non-woven fabric or sheet-like material such as a perforated film to impart hydrophilicity. The kinds of surface-active agents include nonionic surface-active agents and cationic surface-active agents. It may be either an agent or an anionic surfactant, or a mixed system of these surfactants. Examples thereof include fatty acid monoglyceride, polyoxyethylene fatty acid ester, sorbitan ester derivative, alkyl phosphate metal salt, alkyl sulfate metal salt, polyoxyethylene alkyl ether sulfate metal salt, and sugar derivative having a glucose ring. Further, when the material of the porous sheet 2 is mainly a polyolefin resin, a sugar derivative is particularly preferable for the treatment of the inner wall surface 10A.

Next, a method of manufacturing the porous sheet 2 shown in FIG. 3 will be described based on the apparatus shown in FIG. As shown in FIG. 2, the sheet 2 ′ is conveyed while being nipped between the touch roll 21 and the aperture forming roll 22. Further, on the outer peripheral surface of the hole forming roll 22, a plurality of hole forming needle materials 23,
.. are projected, and the surface active agent 15 in the tank 24 is attached to the needle material 23. In such a configuration, the opening 10 of the porous sheet 2 is formed by the needle material 23, and the surfactant 5 on the surface of the needle material 23 is formed by the needle material 23 during the formation.
It is applied to 0A, whereby the porous sheet 2 shown in FIG. 3 is formed. Such a porous sheet 2 has extremely little stickiness, liquid residue on the surface, and liquid spread on the surface, particularly on the surface where the walls of the openings 10 do not project. Further, the porous sheet 2 has excellent liquid absorption performance.

Therefore, such a porous sheet is
It is used as the surface material 2 of FIG. 1, and in this case, it is attached to the absorbent body 4 with one surface 2A of the porous sheet, that is, the surface from which the aperture wall 10 projects, as the inner surface. Therefore, in the absorbent article 1, by avoiding the contact surface with the skin and applying the hydrophilic surfactant 5 only to the inner wall surface 10A of the porous sheet 2, the absorption performance is improved and The skin-contacting surface remains hydrophobic, leaving a non-greasy, dry feel. In the production of the above-mentioned porous sheet, the needle material 23 was used to open the pores, and the inner wall 10A was coated with the surfactant 5. However, it is not limited to this,
As long as the inner wall surface 10A of the opening 10 can be mainly coated, brush coating or spraying may be used. Further, although the absorbent article 1 is the sanitary napkin, the absorbent article 1 is not limited to this and may be another disposable diaper or the like.

(Other Preferred Embodiments) FIG. 4 is an explanatory view of a main part showing a hydrophilic treatment part in producing the porous sheet used in the present invention. In addition, FIG. 5 is an enlarged view of the porous sheet used in the present invention produced in FIG. As shown in FIG. 4, the porous sheet 2 used in the present invention is wound around a part of the outer peripheral surface of the touch roll 30 with one surface from which the above-mentioned aperture wall protrudes outside, and a separation distance is provided around the wound part. The gravure roll 31 is brought into close proximity while preparing. Further, the gravure roll 31 is adapted to be coated with the surfactant 5 at a lower portion (not shown). In such a configuration, as shown in FIG. 5, one surface 2A of the sheet 2 as well as the inner wall surface 10A of the opening 10 of the porous sheet 2 is hydrophilized by the surfactant 5. When the above-described absorbent article is manufactured using such a porous sheet 2, stickiness on the skin-contacting surface, residual surface liquid, and liquid spreading are extremely similar to the porous sheet shown in FIG. Since it is small, it gives a dry feeling to the skin and improves the absorbability of liquid.

FIG. 6 is an explanatory view of a main part showing another hydrophilic treatment part when the porous sheet of FIG. 5 is produced. As shown in FIG. 6, the porous sheet 2 is moved in the direction of arrow A, and a brush roll 40 for coating the surfactant 5 is provided in the moving region. The lower part of the brush roll 40 is immersed in the surfactant solution. Moreover, the brush roll 40 side is sucked by the suction device (not shown) with the porous sheet 2 as a boundary, and air is sucked in the direction of arrow B. Even with such a configuration, the porous sheet 2 shown in FIG. 5 can be manufactured and can be used as the surface material of the absorbent article 1. The coating method is not particularly limited, such as brush coating, spraying, gravure coating, and before and after opening.

[0015]

EXAMPLES Examples according to the present invention will be shown below. The present invention is not limited to the examples below. Examples 1 to 4 Example Sample 1. For a polyolefin-based porous film with a thickness of 600 μm, selectively only on the inner wall of the pores,
Decyl glucoside was applied at a coating amount of 0.05 g / m ² . Example sample 2. For a polyolefin-based porous film with a thickness of 600 μm, selectively only on the inner wall of the pores,
Polyoxyethylene lauric acid ester (EO12mol
The additive) was applied at a coating amount of 0.05 g / m ² . Example sample 3. For a polyolefin-based porous film with a thickness of 600 μm, selectively only on the inner wall of the pores,
Polyoxyethylene lauryl ether sulfate sodium salt (EO 3 mol adduct) was applied at a coating amount of 0.05 g / m ² . Example sample 4. Thickness 120μm, basis weight 25g / m ²
The polyoxyethylene lauryl ether sulfate sodium salt (EO 3 mol adduct) was selectively added only to the inner wall portion of the pores of the polyolefin-based porous non-woven fabric of No. 1.
The coating amount was 075 g / m ² . As described above, the evaluation samples were obtained by wrapping the commercially available napkin absorbers with the example samples 1 to 4.

Comparative Examples 1 to 4 Comparative Example Sample 1. A 600 μm thick polyolefin-based porous film was subjected to a corona discharge treatment in a primary applied voltage of 110 V, a treatment speed of 5 m / min, and an air atmosphere. Comparative example sample 2. A 600 μm-thick polyolefin porous film was coated with decyl glucoside at a coating amount of 0.05 g / m ² on the entire resin surface. Comparative example sample 3. A polyoxyethylene laurate ester (EO 12 mol adduct) was applied to the entire surface of the resin on a 600 μm-thick polyolefin-based porous film at a coating amount of 0.05 g / m ² . Comparative sample 4. Thickness 120μm, basis weight 25g / m ²
Polyoxyethylene lauryl ether sulphate sodium salt (EO 3 mol adduct) was applied to the entire polyolefin-based perforated non-woven fabric of (3) at a coating amount of 0.075 g / m ² .

The obtained comparative sample was used as an evaluation sample by wrapping a commercially available napkin absorber as in the case of the example sample. Absorbency was evaluated for each of them by the following test methods. The results are shown in Table 1.

[0018]

[Table 1]

Glycerin solution absorption time A commercially available napkin absorber was wrapped with a test piece and sandwiched in a glass cylinder having an inner diameter of 35 mm. 5 cm ³ of a glycerin / water = 85/15 wt% solution was poured from above and the time taken to absorb all the solutions was measured. Further, the liquid residual property was evaluated from the observation of the surface state after the liquid absorption and the increase in weight. The stickiness was evaluated by touch in the black box. With respect to the liquid residual property and stickiness, the four grades of ⊚, ◯, Δ, and × are shown from the best.

[0020]

EFFECTS OF THE INVENTION The porous sheet according to the present invention has extremely little stickiness on the surface, liquid remaining, and liquid spreading, and is excellent in liquid absorbing performance. Further, the absorbent article according to the present invention does not give the skin an unpleasant feeling.

[Brief description of drawings]

FIG. 1 is a perspective view of an absorbent article according to the present invention.

FIG. 2 is an explanatory view of a main part showing a hydrophilic treatment part when a porous sheet used in FIG. 1 is produced.

3A to 3C are enlarged cross-sectional views of various preferable embodiments of a porous sheet.

FIG. 4 is an explanatory view of a main part showing a hydrophilic treatment part when a porous sheet used in the present invention is produced.

5 is an enlarged cross-sectional view of a porous sheet produced by using the hydrophilic treatment section of FIG.

FIG. 6 is an explanatory view of a main part showing a hydrophilic treatment part when a porous sheet used in the present invention is produced.

[Explanation of symbols]

 1 Absorbent Article 2 Surface Material (or Porous Sheet) 2A One Side 3 Back Material 4 Absorber 5 Surfactant 6 Nonwoven Fabric 7 Film 10 Opening Hole 10A Inner Wall Surface

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁵ Identification code Internal reference number FI technical display location 2119-3B A41B 13/02 E 7603-4C A61F 13/18 330

Claims (2)

[Claims] 1. An absorbent article comprising a liquid-permeable surface material, a liquid-impermeable back material, and an absorber provided therebetween, wherein a plurality of liquid-permeable holes are provided as the surface material. Use of a porous sheet having a porous sheet having a hydrophilic treatment on the inner wall surface of the liquid permeation opening of the porous sheet or on the sheet surface on the absorber side together with the inner wall surface. Absorbent article. 2. The absorbent article according to claim 1, wherein the porous sheet is a film or a nonwoven fabric, or a laminated sheet thereof.