JPH082364B2 - Sanitary goods surface materials - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention generally relates to a surface material that can be suitably used for sanitary articles such as disposable absorbent articles, and more specifically, sanitary napkins and similar articles. The present invention relates to a surface material for a perforated molded film which can be suitably used for the sanitary ware.

[Conventional technology and its problems]

The absorbent article used for absorbing and retaining liquid from the human body has a structure in which an absorbent body for absorbing and retaining liquid is interposed between a liquid-permeable surface material and a liquid-impermeable leak-proof film. What is formed is public knowledge. In this absorbent article, the liquid-permeable surface material (sometimes referred to as the topsheet or coverstock) does not effectively transfer the liquid to be absorbed into the absorbent body, of course. It is required that the liquid does not return to the human body, gives a dry feeling to the human body, and has a good texture when it comes into contact with the human body surface.

To achieve this purpose, many proposals have been made and many improvements have been made. For example, a non-woven fabric, which is a hydrophobic fine fiber aggregate, is used as the surface material, and the permeability of the fluid is not impaired by designing a void under a hydrophobic atmosphere between the human body surface and the absorber, and A technique for reducing liquid return and providing a substantially dry surface (Japanese Patent Laid-Open No. 58-18060)
Or, a technology that further reduces the liquid return from the absorber by providing holes in the hydrophobic liquid impermeable film (Japanese Patent Publication No. 57-17081,
Typical examples are JP-A-57-1340).

However, in these techniques, in a non-woven fabric using a hydrophobic material, the liquid to be transferred to the absorber is easily retained in the minute space inevitably formed as an aggregate of fibers, and easily retained when pressure is applied. There is a drawback that the liquid migrates to the body surface. In particular, in the case of a colored liquid such as menstrual blood, it is a major visual defect.

On the other hand, it has been proposed that a liquid-impermeable film is provided with specific openings to improve the retention of the liquid of the surface material and not to impair the original function of the surface material. Therefore, it is necessary to increase the aperture area for the free passage of liquid. Due to the loss of hydrophobicity inside the opening, it is not always possible to prevent the liquid from returning in the opposite direction, and in the case of absorbing colored liquid, the liquid is observed from the opening and it is not always the desired surface material. It can not be said.

Therefore, it is desired to develop a surface material that can quickly transfer a fluid to an absorber as soon as possible, does not return liquid, and can cover the color of the absorbed liquid even when absorbing the colored liquid. There is.

[Means for solving problems]

The present inventors have completed the present invention as a result of intensive studies to overcome the above problems.

That is, the present invention is a surface material for a sanitary article which covers the surface of an absorbent body, which contains a hydrophobic film having openings provided in at least a part thereof, and the absorbent body is provided at the periphery of the openings. There is provided a protruding thin film, which is movable and does not completely cover the opening, thereby providing a surface material for hygiene products.

 Hereinafter, the present invention will be described in more detail with reference to the drawings.

FIG. 1 is a perspective view showing a typical example of the surface material of the present invention, and FIG. 2 is an enlarged view of the opening thereof.

The preferred surface material of the present invention comprises an opaque hydrophobic film or a fiber assembly laminated with a hydrophobic film having a concave portion composed of a top portion 1, a bottom portion 2 and a wall portion 3 connecting them, the wall portion 3 being The inclined portion has an inclined portion, the opening 4 is provided in at least a part of the inclined portion, and the inclined portion having the opening is not covered by the top portion 1, and the absorber 4 is provided in the peripheral portion of the opening 4. There is at least one thin film 5 of the hydrophobic film protruding to the outside. The opening 4 serves as a passage port for the liquid discharged from the human body.

The surface material of the present invention is different from the hydrophobic film having tapered capillary-shaped openings disclosed in Japanese Patent Publication No. 57-17081 in that it absorbs a colored liquid, and the openings are partially formed in the hydrophobic film. By providing a thin film projecting to the absorber side in the periphery of the opening, it is possible to rapidly transfer the liquid discharged from the human body to the absorber (hereinafter referred to as liquid permeability). Even in the case of the opening, the effect of effectively preventing the liquid from returning from the absorber to the surface after absorbing the liquid (hereinafter, referred to as liquid return prevention property) is large. In particular, this effect is further enhanced by installing the opening in the inclined portion. Although the above-described effect can be recognized by providing a simple opening in the inclined portion, by providing a thin film projecting to the absorber side in the peripheral portion of the opening in the inclined portion, the thin film moves and the effect can be remarkably exhibited.
The size of the movable thin film depends on the substance constituting the lower layer part of the perforated hydrophobic film, but at least the open part is not completely covered, that is, the total area of the thin film is the open part. It is preferable that one or more thin films exist for each opening, and it is more preferable that the number of thin films be smaller than the partial area.

Further, if the sloped part having the openings is not covered by the top, the openings are present in the surface material even when the absorbent article is subjected to a large pressure by the body of the wearer, and the liquid is Permeability does not decrease and is preferred. On the other hand, when the inclined portion having the opening is covered with the top portion, when the pressure is applied, the opening portion is blocked by the top portion, which may significantly reduce the liquid permeability.

Another important advantage of providing an aperture in the ramp of the wall is that the liquid quickly separates from the wearer's body surface and that the liquid flows away from the body surface. As a result, keep the user's skin dry (hereinafter referred to as surface dryness).
It can be used comfortably.

The apparent thickness of the surface material, that is, the distance between the top and bottom is
Although it can be arbitrarily determined within a range that provides sufficient liquid return prevention property and surface dryness, 0.1 to 5 mm is usually preferable.

The size of the openings and the density of the openings can be arbitrarily determined within a well-balanced range of the liquid permeability, the liquid return prevention property, and the shielding property, but usually the size of the holes is 0.02 to 30 mm ² . In addition, the open pore density is preferably 1 to 100 holes / cm ² .

Further, the angle (α in FIG. 5) between the plane formed by the apex connected to the wall portion having the opening and the inclined portion is within the range in which the opening is not covered by the apex, that is, smaller than the right angle. Is preferable, but it is usually necessary to obtain sufficient liquid return prevention and shielding properties.
It is more preferably 20 ° or more.

The hydrophobic film used in the present invention is preferably opaque. When the hydrophobic film itself is opaque, the surface material having pores of the present invention also becomes opaque and can be preferably used as the surface material of an absorbent article that absorbs a colored liquid such as menstrual blood. The opacity of the surface material having the openings is quantified as whiteness (see Examples), and the whiteness is preferably 10% or more.

Various methods are conceivable as a method for imparting opacity. For example, a method of adding a white pigment such as titanium oxide or zinc oxide to a resin in the film manufacturing process,
Examples include a method of coating a white pigment on the film surface by mixing with a suitable binder such as acrylic, vinyl, or rubber, but if the desired opacity can be imparted, it is not limited to these methods. You may use.

A composite obtained by laminating a hydrophobic film on a fiber assembly such as a nonwoven fabric or paper can also be preferably used in the present invention. Also in the fiber assembly laminated with this hydrophobic film, the form of the apertures is exactly the same as when the film alone is used. As for the size of the thin film,
It is preferable that the size from the fiber assembly, that is, from the surface in the direction opposite to the laminated side, is smaller than the open area of the fiber assembly as the sum of the areas.

As a main component of the hydrophobic film, a polyolefin, a copolymer of an olefin and an acrylate ester, another monomer such as vinyl acetate, any hydrophobic resin such as polyester, polyamide, or cellulose acetate can be used. A polyolefin or a copolymer of an olefin and another monomer is preferable in terms of texture.

As a method for laminating a fiber assembly such as a non-woven fabric or paper, a known method can be used, for example, bonding using an adhesive such as hot melt, or thermal bonding lamination from a heat-melted thin film. Can be mentioned.

Examples of methods for forming openings in a hydrophobic film include a method of embossing, which is represented by embossing, a suction method by vacuum, a pressure method by air pressure, and the like. An appropriate method can be selected according to the shape of the open hole.

Further, in order to enhance the liquid permeability of the perforated hydrophobic film or hydrophobic laminated film, a hydrophilic fiber such as pipe or rayon can be attached to the inside (absorber side) thereof.

Referring back to the drawings again, a typical example of the surface material according to the present invention will be described.

In the surface material shown in FIG. 2, the bottom portion 2 is formed adjacent to the opening 4, but the bottom portion 2 may be installed separately from the opening 4 as shown in FIG. However, in the case of the surface material shown in FIG. 2, the liquid discharged onto the bottom is rapidly transferred from the opening 4 to the absorber, but in the case of the surface material shown in FIG. Since the liquid may be retained in the space formed by 3, it is more preferable to adopt the structure as shown in FIG.

In the surface material shown in FIGS. 2 and 3, the shape of the opening 4 is rectangular, but the shape of the opening 4 is not particularly limited, and may take any shape such as a semicircle as shown in FIG. be able to.

In the above example, the aperture does not necessarily have to be present in the illustrated wall ramp, but can be in any wall ramp.

As described above, as can be understood from the examples shown in FIGS. 1 to 4, the preferable surface material of the present invention is a hydrophobic film or a hydrophobic film having a concave portion composed of a top portion, a bottom portion and a wall portion connecting them. Made of a fiber assembly laminated with a flexible film, the wall has an inclined part that is inclined, at least a part of the inclined part is provided with an opening, and the inclined part having the opening is covered at the top. Instead, the thin film protruding toward the absorber is formed in the periphery of the opening to allow the fluid to pass freely even when pressure is applied, with little liquid return, and for absorbing colored fluid. Also, it is a surface material which can reduce the coloration after absorption and is suitably used for absorbent articles, particularly sanitary articles such as sanitary napkins that absorb colored liquids such as menstrual blood.

The surface material of the present invention is not limited to the above-mentioned examples, and various modifications can be made within the range defined above.

〔Example〕

Hereinafter, how useful the present invention is will be described with reference to specific examples, but the present invention is not limited to these examples.

Examples 1 to 9 and Comparative Examples 1 to 2 Using the constituent materials shown in Table 1, various surface materials shown in Table 2 were prepared by a predetermined method.

The method of measuring the physical properties of each constituent material and surface material will be described below. Each physical property value is an average value of 10 measured values.

(1) Method for measuring physical properties of constituent materials Film layer i) Size of opening: An enlarged photograph of the opening surface viewed from the vertical direction is taken using a stereoscopic microscope, and the size of the opening on the photograph is taken. The value a was measured using a planimeter, and the size A of the actual aperture was calculated by the equation (1).

A (mm ² ) = a (mm ² ) / x ² (1) x: Magnification of photograph against actual product ii) Density of open pores: Measured by counting the number of open pores per 1 cm ^{2 of} surface material.

iii) Inclination angle: The cross section of the surface material was photographed as shown in FIG. 5, and the angle indicated by α was measured with a protractor, and this was taken as the inclination angle.

iv) Whiteness: Measured using a ND-101DP type colorimetric color difference meter manufactured by Nippon Denshoku Industries Co., Ltd. First, after calibrating so that the reflectance of the standard white plate (barium sulfate) for light with a wavelength of 500 nm (green) is 100%, measure the reflectance of each surface material sample for light with the same wavelength, This was defined as whiteness. In addition, the detailed operation method conformed to "101DP type instruction manual".

 Fiber layer i) Basis weight: The weight of the fiber layer was measured to calculate the basis weight.

(2) Surface material: For evaluation, a commercially available sanitary napkin "Laurier"
Instead of removing the surface material (manufactured by Kao Corporation), each surface material was constituted, and this was evaluated as a napkin assumed sample.

Absorption time and amount of fluid returned: 10 g of horse defibrinated blood was injected into a sample napkin sample under a pressure of 5 g / cm ² , and the time required for absorption was defined as the absorption time. In general, the smaller the absorption time, the better the liquid permeability of the surface material. Further, after a certain period of time, the pressure was increased to 50 g / cm ² , and the amount of the test liquid returning from inside through the surface material was measured, and the amount was referred to as a liquid return amount. The smaller the amount of this liquid returned, the less stickiness on the surface and the better the feeling of use.

Visual dryness: The state after absorbing 4 g of equine defibrinated blood in the assumed napkin sample was classified into the following four ranks.

Grade 4: No red color of blood is observed.

Grade 3: Red color of blood is very slight.

Grade 2: Some red color of blood is observed.

1st grade: Red color of blood is noticeable as it causes discomfort.

As shown in Examples 1 to 9, the surface material of the present invention is
The absorption time and the amount of liquid returned are small, the visual dryness is good, and the texture is also very good. In particular, Examples 1 to 8 which also satisfy the second claim are at a particularly high level in terms of the liquid return prevention property and the visual dryness, and can be said to be exactly ideal surface materials. On the other hand, in Example 9, the inclination angle is 6 °, that is, the surface material does not substantially have a three-dimensional shape, and therefore the liquid return prevention property and the visual dryness are slightly inferior.

On the other hand, in Comparative Examples 1 and 2, since there is no thin film around the openings, the liquid permeability, the liquid return prevention property, and the visual dryness are poor, and it is found that the surface material is insufficient. .

[Brief description of drawings]

FIG. 1 is a perspective view showing an embodiment of the surface material of the present invention, and FIG.
The figure is an enlarged view of the open hole portion, FIGS. 3 to 4 are enlarged views of the open hole portion of another embodiment of the surface material of the present invention, and FIG. 5 is a view showing a method for measuring the inclination angle. 1: Top, 2: Bottom 3: Wall, 4: Opening 5: Thin film

Claims (2)

[Claims] 1. A surface material for a hygiene article which covers the surface of an absorbent body, which contains a hydrophobic film having openings formed in at least a part thereof, and the periphery of the openings is provided on the absorbent body side. A surface material for a sanitary article, which is provided with a protruding thin film, which is movable and does not completely cover the opening. 2. A hydrophobic film has a concave portion composed of a top portion, a bottom portion and a wall portion connecting them, the wall portion has an inclined portion which is inclined, and an opening is formed in a part of the inclined portion. The surface material for a sanitary article according to claim 1, wherein the inclined portion provided with holes and having an opening is not covered by the top.