JPH05317359A - Surface member of absorbent article - Google Patents

Abstract

PURPOSE:To provide a surface member of an absorbent article with liquid permeability, either the property of preventing returning of liquids or dryness by which the liquids are not allowed to remain on the skin, fitness by which the article is not felt foreign when worn, and a shielding property by which the color of the liquids absorbed is not exposed to the surface. CONSTITUTION:A surface member 1 is made of a liquid impermeable material covering the surface of an absorber of an absorbent article and has numerous pores P therethrough and includes numerous top portions 3 comprising projecting curved faces, bottom portions 4 comprising recessed curved faces, and connecting portions 5 for connecting the top portions 3 to the bottom portions 4. The pores P are each formed by the top portions 3 and the bottom portions 4 connected together by the connecting portions 5 and the body contact surfaces of the top portions are independent of one another to provide a structure having spaces 3a among the top portions 3. Liquid transmitting pores 6 communicating with the spaces 3a among the top portions 3 are formed in the bottom portions 4 and the height M3 of each bottom portion 4 is smaller than the height M1 of each top portion 3 and/or the height M2 of each connecting portion 5.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a surface material for absorbent articles such as sanitary napkins and diapers.

[0002]

2. Description of the Related Art Generally, absorbent articles such as sanitary napkins and diapers include an absorber that absorbs liquid such as blood and urine, a surface material that covers the surface of the absorber and is applied to the skin, and the above-mentioned absorber. And a back surface material that covers the back surface of the above and prevents liquid leakage. The surface material of the absorbent article is required to have liquid permeability so that liquid such as blood and urine can be rapidly transferred to the absorbent body and absorbed by the absorbent body. A liquid return prevention property that does not return the absorbed liquid to the skin side, a dry property that does not essentially leave the liquid on the skin, and a shielding property that shields the color of blood or the like diffused in the absorber are required.

Conventionally, in order to meet the above demands, for example, a nonwoven fabric which is a hydrophobic fine fiber aggregate is used, and a liquid atmosphere is impaired by forming a space under the hydrophobic atmosphere between the skin and the absorbent body. Without reducing the liquid return from the absorber (Japanese Patent Laid-Open No. 58-18060) or a hydrophobic liquid-impermeable sheet provided with holes to reduce the liquid return from the absorber. Materials (Japanese Utility Model Publication No. 54-124398, Japanese Patent Publication No. 57-17081, Japanese Patent Application Laid-Open No. 57-1340, Japanese Patent Application Laid-Open No. 61-45753, etc.) have been proposed. Further, among the above-mentioned surface materials, as a further improvement of the latter surface material, a surface material provided with micro-embossing so that the non-opened base surface adheres to the skin and gives discomfort is also proposed. Has been done.

[0004]

Since the former surface material described above is a structure of fine fiber aggregates, when it comes into contact with the body, the area of the contact surface is extremely small, and the body and the surface material are in contact with each other. Even when a shearing force is applied between the fibers, free relaxation occurs between the fibers constituting the surface material,
The ability to relieve stress can provide a very comfortable texture. However, in the case of this surface material, when the liquid is discharged, conversely, the liquid easily accumulates in the minute spaces in the fiber assembly, and when pressure is applied, the accumulated liquid migrates to the surface side (skin side) and becomes sticky. In addition to the tactile discomfort such as sticking, there is a drawback that it is visually unpleasant such as being stained with blood.

Further, the latter surface material mentioned above uses a hydrophobic film and is provided with openings for free movement of the liquid, and contrary to the former fiber assembly, When it comes into contact with the skin, since it is a continuous body of hydrophobic film, the area in contact with the body is extremely large, and it interferes with the physiological functions of the skin, such as heat dissipation and moisture release, causing not only discomfort but also itchiness and itchiness. It has the drawback of causing disabilities. Further, the latter surface material has a drawback in that even when a shearing force is applied between the body and the surface material, the surface area of contact with the body is large, resulting in remarkably resistance and giving an unpleasant feeling of use. .. Further, a technique for imparting micro unevenness to a film having a hydrophobic opening to prevent the above-mentioned drawbacks has been conventionally proposed, but according to such a conventional technique, an effect is recognized in a dry state before excretion. In the moist state after excretion, the essential physiological disorder of the skin has not been prevented yet.

Further, in the latter hydrophobic film described above, when a liquid such as blood is excreted, since the continuous layer of the hydrophobic film exists, the liquid is not retained in the surface material layer, Further, if titanium oxide or the like having a shielding effect is blended, there is also a shielding effect on menstrual blood, and a great effect of providing a visual cleanliness after use can be obtained. However, during the use of the latter surface material, when the surface material is in close contact with the body, there are many phenomena in which excreted liquid is present between the continuous layer of the hydrophobic film and the hydrophilic skin. Has not yet been given a comfortable and dry condition. Furthermore, all of the above-mentioned conventional surface materials were made of a flexible material, but the shear yield stress in the direction along the surface of the surface material was large, and there was a feeling of discomfort during mounting.

Therefore, an object of the present invention is to have liquid permeability that allows liquid to freely migrate, and also to prevent liquid from returning once absorbed liquid returns to the skin side or dry property not to stay on the skin. An object of the present invention is to provide a surface material for an absorbent article that has wearability that does not give a feeling of strangeness when worn and a shielding property that hides the color of the absorbed liquid so as not to appear on the surface.

[0008]

SUMMARY OF THE INVENTION The present invention relates to an absorbent article having an absorbent body, the surface material comprising a liquid impermeable material covering the surface of the absorbent body and having innumerable pores. Includes a myriad of tops each having an uneven curved surface, a myriad of bottoms each having a concave curved surface, and a connecting portion that connects the top and the bottom, respectively, and the holes are respectively formed by the connecting portions. The body contact surface of the top formed by the connected top and bottom is independent of each other, and has a structure having a space between the tops, and the bottom has a liquid communicating with the space between the tops. The above object can also be achieved by providing a surface material for an absorbent article, which is characterized in that a perforation hole is formed and a height of the bottom portion is smaller than a height of the top portion and / or the connection portion. It is.

[0009]

With the structure of the present invention, the liquid holding space is larger than the conventionally proposed one in which the wall portion is formed vertically or simply tapered, and even if body pressure is applied to the bottom portion, By bending this bottom to relieve this stress, it gives a soft feeling at the time of mounting, and prevents the space at the top and the liquid permeation opening from closing, and at the same time, the liquid permeation opening from the space between the tops. Fulfill the function of leading to.

Such an action cannot be obtained by a conventional surface material having a solid aperture in a continuous plane. To further elaborate the above-mentioned action, since the apex has innumerable independent apexes composed of uneven curved surfaces, when the apex comes into contact with the body, the contact area becomes extremely small and the physiological function of the skin is not hindered. .. The height of the bottom is the top and / or
Alternatively, since the height is smaller than the height of the connecting portion, the bottom portion is not easily deformed even when body pressure is applied, and the opening is not blocked. In addition, even if the liquid is excreted, the contact area is small, so that even if it is a hydrophobic film, the liquid hardly stays on the body side and the dryness (dry feeling)
To give. Moreover, if the cross section of the surface material at arbitrary positions has a shape that is bilaterally asymmetric with respect to the center line in the thickness direction passing through the center of the hole, the surface material is practically used during actual use. In addition, the liquid holding space becomes large, and even when a large amount of liquid is excreted, it can be effectively transmitted to the absorber, and further, it can be absorbed from any direction.

[0011] These are essentially different from the conventional apertured form of the hydrophobic film that has been conventionally proposed (proposed that the tapered capillary tube or the wall portion is vertical, etc.), and the uneven shape that does not form a continuous flat surface. It is superior to the conventional ones in terms of the transferability with the retention of liquid on the body side due to the curved surface and the excretion of large amounts of liquid. That is, in actual use, it is used in a stressed state, and the surface material of the present invention satisfies the absorbency under such stress, the contact area with the skin, and the adhesion of the liquid to the skin. is there.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS First, one embodiment of the surface material of the absorbent article of the present invention will be described with reference to the accompanying drawings. 1 to 5 show an embodiment of a surface material of an absorbent article of the present invention, and FIG. 1 is a perspective view showing a part of an absorbent article provided with a surface material according to an embodiment of the present invention in a cutaway view. FIG. 2 shows an embodiment of a surface material of an absorbent article of the present invention, FIG. 2 (A) is a partially enlarged plan view of the surface material according to this embodiment, and FIG. ) Is a partially enlarged perspective view of the surface material shown in FIG.
FIG. 3 shows gold knitting used for manufacturing the surface material of the absorbent article of the present invention, and FIG. 3 (A) is an enlarged plan view of the gold knitting, further showing a visual direction in FIG. 3B is an enlarged perspective view of the gold knitting shown in FIG. 3A, FIG. 4 is a plan view of the surface material according to the present embodiment, FIG. 4A is an enlarged plan view, and FIG. 3 is a cross-sectional view of the hole in the visual direction of FIG. 3, FIG. 5 is a cross-sectional view of the hole of the surface material according to the present embodiment, and FIG. 5A is a cross-sectional view in each visual direction shown in FIG. FIG. 4E is a cross-sectional view in each viewing direction shown in FIG.

The surface material 1 according to the present embodiment is a surface material made of a liquid impermeable material that covers the surface of the absorbent body 2 of the absorbent article having the absorbent body 2 and has an infinite number of holes P. (See FIG. 2). Specifically, the molten resin was applied along the surface shape of the right-handed or left-handed spiral-wound wire mesh 7 of the same direction (see FIGS. 3A and B) as a surface material molding die. It is formed into a sheet having a shape and a hole portion at a position corresponding to the space between the wire rods of the spiral braided wire net 7. That is, as shown in FIGS. 2A, 2B, and 5, the surface material 1 is a concave-convex curved surface formed into a shape that conforms to the surface shape of the wire material located at the uppermost part of the spiral braided wire mesh 7 (see FIG. 3). Innumerable tops 3 and spiral knitted wire mesh 7
Innumerable bottom portions 4 that are formed into concave curved surfaces by dropping into the space between the wire rods, and connecting portions 5 that connect the top portions 3 and the bottom portions 4 to each other.
Each of the holes P is formed by the top portion 3 and the bottom portion 4 which are connected by the connecting portion 5, and the body contacting surfaces of the top portion are independent of each other, and a space is provided between the top portions 3. 3a, and the bottom 4 is formed with a liquid permeation hole 6 that communicates with the space 3a between the tops 3, and the height M ₃ of the bottom 4 is equal to the top 3
The height is smaller than the height M ₁ and / or the height M ₂ of the connecting portion 5.

Further, the cut surfaces of the respective surface portions passing through the center of the holes in the respective hole portions P at different arbitrary positions in the thickness direction are formed to be asymmetrical or irregular. Further, the top portion 3 presents a contact surface having a dot-like or linear shape and / or physical properties when no load is applied, and presents a contact surface having an elliptical outer circumference according to the load when applied. .. When manufacturing the surface material, by appropriately selecting the resin composition and manufacturing conditions such as the viscosity at the time of melting the resin, the direction of vacuum suction, the direction of pressure flow pressurized from the side opposite to the suction, the shape of the wall Can be formed in a “spiral shape” corresponding to the shape of the spiral braided wire mesh 7 described above. Further, if the flexibility of the peripheral portion of the liquid permeation opening 6 is formed to be high, the height of the bottom portion is low, so that this portion acts as a valve to the absorber 2 without blocking the opening. It is also possible to enhance the liquid-conducting property and the liquid return-preventing property.

Here, as the liquid impermeable material (hydrophobic sheet) constituting the surface material 1, a polyolefin, a copolymer of an olefin and an acrylic ester, another vinyl monomer such as vinyl acetate, polyester, Examples include hydrophobic thermoplastic resins such as polyamide alone or in a blend system, and blend systems with a hydrophilic resin such as polyvinyl alcohol or polyoxyethylene. Among these, from the viewpoint of texture and handling, polyolefin or olefin and other A hydrophobic thermoplastic resin sheet of a copolymer with the above monomer or a polymer blend is preferable.

Further, although the color of the liquid such as blood and urine absorbed in the absorber 2 can be shielded by the top portion 3 and the bottom portion 4 and the like, it is shielded that the liquid impermeable material itself is opaque. It is preferable in terms of sex. Various means can be considered as means for making the liquid-impermeable material itself opaque. For example, white pigments such as titanium oxide and zinc oxide, fillers such as calcium carbonate, talc, clay, calcium sulfate and barium sulfate, which may be used alone or in combination, are added in the molding process of the surface material 1. .

Further, the top portion 3 of the surface material 1 has a roundness so as to give a soft feeling by making point contact with the skin, and the liquid which stays in the body even after the surface material 1 absorbs the liquid. Although it is made extremely small and gives a substantially dry feeling, it is more preferable to add micro unevenness to the top. Such micro-roughening can be achieved by forming irregularities on the surface of the wire material of the spiral knitting metal knitting used for molding of the surface material and transferring it by molding the surface material, or by pressing, polishing, electric discharge treatment after molding the surface material. Alternatively, it can be obtained by adding the above-mentioned inorganic filler and high-melting point organic particles. Next, the shape of the holes of the surface material 1 will be described.

In the present embodiment, any cut surface of the hole P has a left-right asymmetrical shape, but as a typical example, FIG.
The cut surfaces visually observed from the directions of (a) and (e) shown in (A) and FIG. 4 (B) are shown in FIGS. 5 (A) and 5 (E).

Height M of top 3₁Is 0.05 mm to 2.0
mm is preferable, and 0.1 to 0.5 mm is more preferable. Linking
Height M of part 5₂Is preferably 0.05 mm to 2.0 mm,
0.1 to 0.5 mm is more preferable. Height M of bottom 4
₃Is preferably 0.05 mm to 1.0 mm, and 0.1 to 0.
3 mm is more preferable. However, M₁, M₂, M₃Is above
M in any range₃Is always M ₁And / or
Is M₂Is set smaller than. Also, the top 3 and the top
The distance L between the space 3a and the portion 3 is in the range of 0.05 mm to 8 mm.
It is preferable to set it in the range of 0.2 mm to 5 mm.
It is more preferable to set it in the range.

As described above, the shape of the liquid permeation opening 6 is different in the thickness-wise cut surface passing through the center of one hole.
Also has a non-planar shape, and also has a slanting hole shape facing in one direction as a whole. The peripheral length of the liquid permeation opening 6 (which connects the tips of the bottom portions) is preferably 0.1 mm to 15 mm, and is preferably 0.1 mm to 15 mm.
It is more preferably 5 mm to 5 mm.

The opening area of the liquid permeation opening 6 is 0.0
It is preferably ² mm ^{2 to} 9 mm ² . Open area is 0.
Inferior low and liquid permeability than 02mm ^2, and because poor greater the liquid return than 9 mm ^2. Aperture density of the liquid passage for opening 6 is preferably a two / cm ² to 100 pieces / cm ^2. This is because when the open pore area is small and the open pore density is small, the liquid permeability is substantially inferior, and as the open pore area is large, the sheet formability is deteriorated. Therefore, the hole density and the perimeter of the holes are set in consideration of these circumstances.

A back surface material 8 (see FIG. 1) is arranged on the back surface of the absorbent body 2 to cover the back surface and prevent liquid leakage. Next, the operation of the surface material 1 of this embodiment will be described. When the absorbent article provided with the surface material 1 is mounted, blood, urine, etc. are transferred from the surface material 1 to the absorbent body 2 and absorbed by the absorbent body 2. At this time, the surface material 1 has liquid permeability due to the liquid permeation openings 6, and the top 3 is deformed due to the variation of the mounting pressure to increase or decrease the contact area with the skin. In this case, this effect is remarkable, and the effect is significantly different from the conventional three-dimensional opening.

The surface material 1 is deformed so as to close the liquid permeation opening 6 when a tensile force along the surface thereof acts, and when the tensile force is released, the liquid permeation opening 6 is released.
It returns to its original shape as if it was opened. That is, only when a large force acts when the absorbent article is attached (only when a force that returns the liquid once absorbed in the absorbent body 2 to the skin side acts),
The surface material 1 closes the liquid permeation opening 6, and reliably prevents the liquid from returning from the absorber 2 to the skin side.

By setting the top portion 3, the connecting portion 5 and the bottom portion 4 to have the above-described dimensions and shapes, even if a material having a substantially high elastic modulus is used, the elasticity and compression elasticity are excellent, and the shear yield stress is also high. Is smaller, the shearing force is small in any direction along the surface of the surface material 1, and the surface material can follow the complicated movement of the wearer while the top part 3 is in point contact with the skin, resulting in wearing deviation. No stickiness or discomfort even if it adheres to the skin. The shear yield stress is small in any of the directions along the surface, and the complex movement of the wearer with the top portion 3 in point contact with the skin does not cause a fitting displacement and adheres to the skin without giving a sense of discomfort.

6 and 7 show a surface material 1 according to another embodiment.
It shows 0. The surface material 10 is made of molten resin,
Holes between the wire rods of the spiral braided wire mesh 70 having a shape along the surface shape of the spirally braided wire mesh 70 (see FIGS. 6A and 6B) in which spirals of right-handed and left-handed turns are connected by force bones (rods). Is formed into a sheet having a hole at a position corresponding to. Therefore, the surface material 10
Is, like the surface material 1, a myriad tops 30 each having a convex curved surface that does not have a continuous flat surface, a myriad bottoms each having a concave curved surface, and a connecting portion that connects the top 30 and the bottom, respectively. And each of the holes P
Is a structure formed by the top portion 30 and the bottom portion connected by a connecting portion and having a space between the top portions 30, and the bottom portion has a liquid permeation opening communicating with the space between the top portions. As shown in FIG. 5, holes are formed so that the height M ₃ of the bottom portion is smaller than the height M _{1 of the} top portion and / or the height M _{2 of the} connecting portion. ing.

Further, in this embodiment, each of the holes P is
It is formed so as to be surrounded by the two top portions 30 and a bottom portion connecting the two top portions 30. Furthermore, the top portion 30 has a non-round convex shape whose section is rounded upward and exhibits a contact surface having a dot or line shape and / or physical properties when no load is applied, and an ellipse corresponding to the load when loaded. The same effect as that of the above-mentioned surface material 1 which exhibits a contact surface having a circular outer periphery can be obtained.

[0027]

EFFECT OF THE INVENTION The surface material of the absorbent article of the present invention has a liquid permeability that allows liquid to freely migrate, and has a liquid return preventing property that prevents the once absorbed liquid from returning to the skin side. At the same time, in addition to the wearability that does not give a feeling of strangeness and the shielding property that hides the color of the absorbed liquid so as not to appear on the surface, it has various effects as described above.

[Brief description of drawings]

FIG. 1 is a perspective view showing a partially cutaway absorbent article provided with a surface material according to an embodiment of the present invention.

FIG. 2 shows an embodiment of a surface material of an absorbent article of the present invention, FIG. 2 (A) is a partially enlarged plan view of the surface material according to this embodiment, and FIG. 2 (B) is the same. It is a partial expanded perspective view of the state which looked at the surface material shown in Drawing (A) from the front side.

FIG. 3 shows a wire net as a surface material molding die used for manufacturing the surface material of the absorbent article of the present invention, and FIG. 3 (A) is an enlarged plan view of the metal knitting, and FIG. 6B is a view showing the viewing direction in FIG. 4B, and FIG. 6B is an enlarged perspective view of the gold knitting shown in FIG.

4 is a plan view of a surface material according to an embodiment of the present invention, FIG. 4 (A) is an enlarged plan view, and FIG. 4 (B) is FIG.
It is a figure which shows the cross-sectional position of a hole part in correspondence with the viewing direction shown to (A).

5 is a cross-sectional view of a hole portion of a surface material according to an embodiment of the present invention. FIG. 5A is a cross-sectional view in each visual direction (a) shown in FIG. 4E is a cross-sectional view in the visual direction (e) shown in FIG.

FIG. 6 shows another embodiment of the surface material, which is shown in FIG.
Is a plan view of a surface material according to another embodiment, and FIG. 6B is a partially enlarged perspective view of the surface material shown in FIG.

7 (A) is a partially enlarged plan view of a spiral knitted metal knitting forming the surface material shown in FIG. 6, and FIG. 7 (B) is a partially enlarged perspective view.

[Explanation of symbols]

1, 10 Surface material P Hole 2 Absorber 3, 30 Top 4 Bottom 5 Connecting part 6 Liquid permeation opening M ₁ Top height M ₂ Connection height M ₃ Bottom height

Claims (2)

[Claims] 1. A surface material, which is made of a liquid-impermeable material that covers the surface of the absorbent body of an absorbent article having the absorbent body and has innumerable holes, wherein each of the surface materials has an uneven curved surface. It comprises a myriad of tops, a myriad of bottoms each made up of a concave curved surface, and a connecting part for connecting the tops and the bottoms, respectively, and the holes are respectively connected to the tops and the bottoms. And the body contacting surfaces of the top are independent of each other, and have a structure having a space between the tops, and the bottom has a liquid permeation opening that communicates with the space between the tops, The surface material of an absorbent article, wherein the height of the bottom portion is smaller than the height of the top portion and / or the connecting portion. 2. The absorbent article according to claim 1, wherein arbitrary cut surfaces which are different in the thickness direction of the surface material and which pass through the center of the hole in each of the hole portions are asymmetrical or asymmetrical shapes on the left and right, respectively. Surface material for plastic articles.