JPH0713702Y2 - Absorbent article - Google Patents

Description

[Detailed Description of the Invention] [Industrial field of application] The present invention relates to an absorbent article, and more specifically, it absorbs sanitary napkins, etc., which not only improve the user's feeling of use but also have an excellent leak-proof effect. It relates to a sex article.

[Problems to be solved by conventional techniques and devices]

Conventionally, a basic structure of an absorbent article such as a sanitary napkin that is generally used is configured by including a liquid-permeable surface material, a liquid-impermeable back material, and an absorbent body interposed therebetween, It is formed substantially vertically. And in such an absorbent article, good absorption performance,
In addition to having a high leak-proof effect such as leakage in any state, the liquid absorbed in the absorber does not return and is not sticky, and there is no feeling of discomfort during use, such as feeling comfort. Is strongly demanded.

Therefore, as an absorbent article such as a sanitary napkin, a device for enhancing the liquid absorbing function and the liquid retaining function of the absorbent body, for example, incorporation of a superabsorbent polymer, installation of an elastic body for suppressing deformation, surface treatment, etc. As a material, improvements have been made to the liquid permeability to the absorber and the suppression of liquid return, but it has not been completed yet. This is apparent from the fact that most of the user's dissatisfaction is due to the feeling of leakage, stickiness and slat.

Recently, as a surface material, a non-woven fabric containing a large amount of hydrophobic fibers, a hydrophobic film provided with openings, and the like have been proposed, and absorbent articles such as sanitary napkins using these are also on the market. However, it is difficult to wet due to its hydrophobicity, and on the other hand, it is not sticky, but on the other hand, it has a poor liquid absorbing property and causes leakage. If it is attempted to improve the liquid absorbency, a large opening must be provided, and the absorbed liquid tends to come out, which is disadvantageous in that it becomes sticky. Therefore, it is hard to say that these conflicting relationships are compatible.

[Means for Solving the Problems]

The present inventors, as a result of earnest research to solve the above problems,
As a skin contact surface for a liquid-retaining structure made of polyurethane or polyolefin foam having a three-dimensional skeleton structure and an average distance between skeletons of 150 to 700 μm as a surface material of absorbent articles. If a hydrophobic film is integrated and the hydrophobic film has a hole penetrating the above structure, liquid can be quickly introduced to the absorbent body through the through hole, and further pressure is applied to the absorbent body. The inventors have found that even if the liquid leaks out, it does not return to the body side, has an excellent feeling of use, maintains a smooth surface, and can reliably prevent liquid leakage, and completed the present invention.

That is, the present invention provides an absorbent article having a liquid-permeable surface material, a liquid-impermeable back material, and an absorber interposed therebetween, and the surface material has a three-dimensional skeleton structure. A hydrophobic film is integrated as a skin-contacting surface with a liquid-retaining structure made of a polyurethane-based or polyolefin-based foam having an average distance between the skeletons of 150 to 700 μm. It is intended to provide an absorbent article characterized in that the structure is provided with a hole penetrating therethrough.

〔Example〕

Embodiments of the present invention will be described below with reference to the drawings, but the present invention is not limited to such embodiments.

FIG. 1 is a schematic sectional perspective view showing an embodiment of a surface material used in the absorbent article of the present invention, FIG. 2 is an enlarged sectional view of one hole shown in FIG. 1, and FIG. 1 is a schematic perspective view of a sanitary napkin showing an embodiment of the absorbent article of the present invention to which the surface material of FIG. 1 is applied, and FIG. 4 is an X of the sanitary napkin of FIG.
FIG. 5 is a cross-sectional view of the sanitary napkin showing another embodiment of the absorbent article of the present invention.

As shown in FIG. 1, the surface material 1 has a hydrophilic surface 3
A hydrophobic resin film 3 is integrated with a liquid retaining structure 2 having a dimensional skeleton structure, and a plurality of random depressions 4 are formed in the film 3 in order to increase the liquid absorption rate.
A hole 5 penetrating the structure 2 is provided therein.

Examples of the liquid-retaining structure having a three-dimensional skeleton structure in the present invention include a polyurethane-based foam having an average distance between skeletons of 150 to 700 μm or a polyolefin-based foam such as polyethylene. , Japanese Patent Application Sho 63
-294315, the hydrophilicity of the water-absorbent polyurethane-based foam obtained by the production method as described in the specification (content of ethylene oxide in the total epoxide in the polyol is 20% by weight or more), skeleton structure, It is preferable because compression characteristics and the like can be imparted relatively easily.

In the present invention, the average distance between skeletons means the average diameter of each cell (cell) of the foam (the measuring method will be described later).
By using a structure having an average distance between skeletons of 150 to 700 μm, a liquid-retaining structure having extremely excellent liquid-absorbing property and liquid-retaining property can be obtained. However, when the average distance is less than 150 μm, the liquid-absorbing speed is This is not the purpose of the present invention because it is not practically sufficient, and conversely, the structure having a thickness of more than 700 μm has insufficient liquid retention.

In the foam according to the present invention, the shape of the cell membrane may be such that closed cells may be mixed in the open cells, but in order to obtain higher absorption performance, the open cells are preferable, and among the open cell foams. It is particularly desirable that the porosity of the bubble film (measuring method will be described later) be 40% or more.

The bubble film means a thin film extending from the skeleton, and its composition is substantially the same as that of the skeleton. A bubble in which adjacent bubbles are blocked from each other by this bubble film is called an independent bubble. On the other hand, a bubble film having open pores, that is, continuous pores, in which adjacent bubbles are not blocked from each other is referred to as continuous pores.

On the other hand, the average cell (cell) diameter of the foam corresponds to the distance between the skeletons as described above, and therefore it is necessary to be 150 to 700 μm.

Further, in consideration of the absorption rate, the average pore diameter (the measuring method will be described later) of the communicating pores connecting the bubbles is preferably 20 to 200 μm, and more preferably 60 to 100 μm.

As the elasticity of the structure of the present invention, it is preferable that the compressive stress at 50% deformation (the measuring method will be described later) is 10 to 200 g / cm ² .

In the structure of the present invention, it is preferable that at least the surface of the skeleton has hydrophilicity to some extent. When the material constituting the skeleton is a hydrophobic material, it is treated with an appropriate wetting agent to improve the hydrophilicity of the surface. It is preferable to use it by allowing it to be used, but it is more preferable if the constituent material itself has a certain degree of hydrophilicity, since treatment with a wetting agent is not required and the process is simplified. This hydrophilicity is quantified as a hydrophilicity by a powder method (a measuring method will be described later), and the hydrophilicity is preferably 0.3 or more.

<Measurement method> (1) Measurement of average bubble diameter, bubble film open area ratio and average communicating pore diameter After taking a photograph of the test sample with an electron microscope, each bubble is measured using an image analyzer (Avio EXCEL manufactured by Japan Avionics Co., Ltd.) The area was determined, and the diameter of the circle corresponding to the area was taken as the bubble diameter. The average value of 200 cells was taken as the average cell diameter.

The bubble film open area ratio α was determined by the following equation (1).

N ₀ : Number of communication holes connecting each bubble N ₁ : Number of remaining bubble film connecting each bubble without opening (No + N ₁ = 200) Similarly, for the average communication pore diameter, the area of the pores that connect the bubbles is determined, and the circle equivalent diameter corresponding to the area is defined as the pore diameter. The pore size of the pores where the bubble film is not open is calculated as 0,
The average value of 200 pieces was defined as the average communication hole diameter.

(2) Measurement of 50% compressive stress A sample having a size of 100 mm × 50 mm and a thickness of 5 mm is compressed with a Tensilon compression tester at a compression speed of 10 mm / min and a compression area of 10 cm ² .
The compressive stress per unit area when the sample reached 50% (2.5 mm) of the initial thickness was determined as 50% compressive stress (g / cm ² ).

(3) Measurement of hydrophilicity The hydrophilicity is measured using the device shown in FIG.

First, the following operation is performed using ethanol (EtOH) as the measurement liquid 10.

Set the liquid level at the side port of ethanol in the measuring table 11 and burette 12 at a constant height (so that the pressure becomes equal), and test on the glass filter 15 (No.1) with a diameter of 80 mm in the measuring table 11. Piece 13
(50 mm thick, 40 mm x 40 mm rectangular parallelepiped) is put on and immediately load 14
(Weight 80 g, load pressure 5 g / cm ² ) and leave it for 60 minutes (At this time, the amount of ethanol absorbed by the test piece introduces air from the side port of the buret, and the liquid level at the side port becomes equal. Kept). During this period, the amount of ethanol absorbed by the test piece was determined.

Next, the measurement liquid 10 was changed to physiological saline, and the absorption amount of physiological saline was obtained by the same method as above, and the hydrophilicity cos θ between the physiological saline and the test piece was calculated by the following formula (θ: physiological saline and test The contact angle with one piece) was calculated.

The measurement of the hydrophilicity cos θ is also called a powder method.

The surface material of the present invention comprises a liquid-retaining structure having the above-mentioned three-dimensional skeleton structure and a hydrophobic resin film integrated with the surface of the hydrophobic film, and a hole penetrating the structure. Any hydrophobic resin may be used as long as it can be formed into a film, but a resin that can be laminated is preferable in consideration of being integrated with a structure having a three-dimensional skeleton and having an opening. More preferred are polyethylene and its copolymers. After lamination, the depressions 4 and the random through holes 5 can be easily formed by a known method such as suction or blowing with hot air. The size of the depression 4 is a liquid-retaining structure 2 having a three-dimensional skeleton.
Although it is determined by the surface condition of No. 1, it is preferable that the diameter is in the range of 1 to 5 mm in view of the appearance and the texture during use. The through holes 5 are randomly present in the depressions 4, and the diameter of the through holes 5 is substantially equal to the distance between the skeletons of the liquid retaining structure 2.

The sanitary napkin 8 of the present invention shown in FIGS. 3 and 4 to which the surface material shown in FIG. 1 is applied is a surface material 1 and an ultrathin synthetic resin film such as polyethylene, or the film on paper. It has a backing material 7 made of laminated waterproof paper, and an absorbent body 6 made of defibrated pulp or a highly absorbent polymer interposed therebetween, and is substantially vertically long.

Here, in the surface material 1, only the absorbing surface is opened, and the side surface portion and the non-absorbing surface side are merely laminated, and no opening portion is provided. The sanitary napkin 8 is wound and covered with the surface material 1.

In the sanitary napkin 8, the liquid is the depression 4 of the surface material 1.
From the through hole 5 existing in the inside, it rapidly moves to the absorber 6 and is absorbed. Even if the absorbed liquid leaks from the absorber 6 under pressure, it does not leak to the body side due to the three-dimensional structure 2 having elastic force. Furthermore, the liquid is entirely hydrophobic and exists in the depression 4. The through holes 5 are integrated between the skeletons that open in random directions, and the through holes themselves have random directionality, and as a result, leakage to the body side can be suppressed.

Even if the absorber 6 undergoes any deformation and its shape changes, the surface material 1
Since it itself has absorbing power and elastic recoverability, a certain absorbing performance can be maintained without changing the absorbing performance.

Therefore, the sanitary napkin according to the present invention has no menstrual leakage and the surface is always slatted, and has an excellent feeling of use.

Further, in the present invention, an absorbent body having a three-dimensional skeleton structure, at least the surface of which is hydrophilic, and a liquid retaining structure having an average distance between the skeletons of 50 to 700 μm is used. Is preferred. An example of a sanitary napkin as an embodiment of the present invention using such an absorber is shown in FIG. In the sanitary napkin 9 shown in FIG. 5, the liquid-retaining structure 2 itself having a three-dimensional skeletal structure is configured as an absorber without using defibrated pulp as the absorber. The liquid-retaining structure 2 having a three-dimensional skeleton has a recess 4 and a through hole 5 on the absorption surface side, and the side surface and the non-absorption surface side are laminated only and are not provided with openings. Therefore, the sanitary napkin 9 of the present embodiment can have the same action and effect as the sanitary napkin 8.

The sanitary napkin 9 using the liquid-retaining structure 2 having a three-dimensional skeleton as an absorber has a great advantage in that the manufacturing process can be simplified even on the producer side.

[Advantages of the Invention] The absorbent article of the present invention has a three-dimensional skeleton liquid-retaining structure having an elastic opening having a specific size as a surface material, and a hydrophobic resin laminated on the liquid-retaining structure to penetrate through the absorbent article in a random direction. By using one with holes, the liquid permeation rate is increased,
And, the surface material is hydrophobic and openings in random directions,
Due to its elastic function, liquid does not leak to the body side, stickiness of the absorbent surface is reduced and leakage can be suppressed, and it has an excellent feeling of use, and also absorbs sanitary napkins etc. with a simple structure Articles can also be constructed, and their practical value is extremely large.

[Brief description of drawings]

FIG. 1 is a schematic sectional perspective view showing an embodiment of a surface material used in the absorbent article of the present invention, FIG. 2 is an enlarged sectional view of one hole shown in FIG. 1, and FIG. 1 is a schematic perspective view of a sanitary napkin showing an embodiment of the absorbent article of the present invention to which the surface material of FIG. 1 is applied, and FIG. 4 is an X of the sanitary napkin of FIG.
FIG. 5 is a sectional view of a sanitary napkin showing another embodiment of the absorbent article of the present invention, and FIG. 6 is a sectional view of an apparatus used for measuring hydrophilicity. 1: Surface material 2: Liquid-retaining structure having a three-dimensional skeleton 3: Hydrophobic resin film 4: Indentation 5: Through hole 6: Absorber 7: Back material 8,9: Sanitary napkin 10: Measurement liquid 11: Measuring table 12: Burette 13: Specimen 14: Load 15: Glass filter

Claims (2)

[Scope of utility model registration request] 1. A liquid-permeable front material, a liquid-impermeable back material,
And an absorbent article having an absorbent body interposed therebetween, wherein the surface material has a three-dimensional skeleton structure and an average distance between skeletons is 150 to 700 μm. An absorbent article characterized in that a hydrophobic film is integrated as a skin contacting surface with the liquid retaining structure, and a hole penetrating the structure is provided on the surface of the hydrophobic film. 2. The absorber has a three-dimensional skeleton structure,
The absorbent article according to claim 1, wherein at least the surface of the skeleton is hydrophilic, and the liquid-retaining structure has an average distance between the skeletons of 50 to 700 µm.