JP3407906B2 - Surface material of absorbent article and method of manufacturing the same - Google Patents

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 and a method for producing the same.

[0002]

2. Description of the Related Art Generally, absorbent articles such as sanitary napkins and diapers include an absorbent body that absorbs liquid such as blood and urine, a surface material that covers the surface of the absorbent body, and a surface material that is applied to the skin. 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 the absorbent body can absorb the liquid. A liquid return prevention property that does not return the absorbed liquid to the skin side 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-mentioned demand, for example, a nonwoven fabric which is a hydrophobic fine fiber aggregate is used, and liquid permeability is impaired by forming a space under a hydrophobic atmosphere between the skin and the absorber. Without reducing the liquid return from the absorber (JP-A-58-180602) or a hydrophobic liquid-impermeable sheet provided with pores to reduce the liquid return from the absorber. Materials (see 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.

Among the above-mentioned surface materials, a modification of the latter surface material is a surface material provided with micro-embossing so that the non-opening base surface adheres to the skin and gives discomfort. Is also proposed.

[0005]

However, 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 Even when a shearing force is applied between the surface materials, the fibers constituting the surface material are freely relaxed and the stress can be relaxed, so that an extremely comfortable texture can be provided. However, conversely, when the liquid is excreted, the liquid easily accumulates in the minute spaces in the fiber assembly, and when pressure is applied, the accumulated liquid moves to the surface side (skin side) and becomes sticky. In addition to giving discomfort to the eyes, there is a drawback that it gives a visually unpleasant feeling such as being stained with blood.

The above-mentioned latter surface material uses a hydrophobic film and has openings for free movement of the liquid. When it comes into contact, because it is a continuous body of hydrophobic film, the area in contact with the body is extremely large, which interferes with physiological functions of the skin, such as heat dissipation and moisture release, and causes discomfort as well as disorders such as swelling and itchiness. It has the drawback of causing it. Even when a shearing force is applied between the body and the surface material, the contact area is large, resulting in remarkably resistance and giving an unpleasant feeling of use. It has also been proposed to prevent the above-mentioned drawbacks by imparting micro unevenness to these hydrophobic apertured films, but it is effective in the dry state before excretion, but essential in the wet state after excretion. It has not yet been able to prevent physiological disorders of the skin. When a liquid such as blood is excreted, since the continuous layer of the hydrophobic film is present, the liquid is not retained in the surface material layer. It also has a blood-shielding effect, and has a great effect of giving a visual sense of cleanliness after use. However, when the latter surface material is in contact with the body during use,
There are many phenomena in which excreted liquid exists between the continuous layer of the hydrophobic film and the hydrophilic skin, and it has not been possible to provide a substantially comfortable dry state.

Further, even if any of the above-mentioned conventional surface materials is made of a flexible material, the shear yield stress in the direction along the surface of the surface material is large, and there is a feeling of discomfort during mounting. Therefore, the purpose of the present invention is to have a liquid permeability that allows the liquid to freely migrate, and a liquid return prevention property in which the liquid once absorbed does not return to the skin side and a dry property in which the liquid does not stay on the skin, Wearability that does not make you feel uncomfortable when wearing,
An object of the present invention is to provide a surface material for an absorbent article having a shielding property for hiding the color of the absorbed liquid so as not to appear on the surface, and a method for producing the same.

[0008]

The present invention has achieved the above object by providing the following surface material for absorbent articles.

A surface material for covering the surface of the absorbent body of the absorbent article having the absorbent body, which is made of a liquid impermeable material, has a large number of holes, and the liquid permeation openings are formed in the holes. In the surface material, the surface material has a large number of tops each having a convex curved surface with a void on the back side, a large number of aperture bottoms, and a cylindrical wall portion connecting the tops and the aperture bottoms, respectively. And the apex has a dot-like or linear shape when no load is applied.
It presents a contact surface with a shape and is an ellipse according to the load when loaded.
Exhibits a contact surface having a Jo outer peripheral, each hole is formed respectively from a plurality of said top adjacent, and one of the cylindrical wall portion for connecting them with one of the apertures bottom, the open hole The bottom part constitutes the liquid permeation opening, and has a communication hole structure.Further, each of the hole parts having the communication hole structure has a base closest to the top part at the opening edge of the opening bottom part. At this time, the length from the base to the highest part of the top (this length is the vertical distance in the thickness direction of the surface material) =
L ₁ and from basal to the farthest site for the top of the opening edge length ratio of = L ₂ (the vertical distance in the thickness direction of the length is the surface material) (L ₂ / L ₁₎ is A surface material for absorbent articles, which has a structure of less than 0.5.

Further, according to the present invention, as a preferred method for producing the above surface material, a surface material forming resin is supplied to one surface portion of a surface material molding die made of a spiral braided wire mesh , Vacuum suction is performed from the other surface portion of the surface material molding die, and the surface material forming resin has a shape along the surface shape of the surface material molding die and corresponds to the space between the wire rods of the wire mesh. The present invention also provides a method for producing a surface material for an absorbent article, which comprises forming the sheet having the above-mentioned hole portion. As the surface material forming resin, a sheet-shaped molten resin or a sheet formed into a film in advance is usually used.

[0011]

The surface material of the absorbent article according to the present invention has the above-mentioned structure, and therefore has the following various effects. Compared to the conventionally proposed tubular wall with vertical or mere taper, the liquid holding space is larger, and the surface material moves along the surface by the movement of the wearer (plane direction). When it is pulled to, the liquid permeation opening (opening bottom) is deformed like it is closed, and there is a liquid return prevention property that prevents the liquid once absorbed by the absorber from returning to the skin side. Even if body pressure is applied to the cylindrical wall of
The cylindrical wall bends to relieve this stress, giving a soft feeling when mounting and the space between the tops (holes)
And prevents the liquid permeation opening from closing and at the same time guides the liquid from the space between the tops to the liquid permeation opening. Further, in any direction along the surface of the surface material, since it has an uneven surface morphology mainly composed of a large number of hole forming spaces and a large number of tops, the shear yield stress is small,
Moreover, the top part has a rounded non-round circular convex shape with a void on the back side, and when pressed from above with a flat plate, the outer circumference of the contact surface to the flat plate becomes a non-round shape depending on the load. long becomes, because when the unloaded having <br/> a shape exhibiting a contact surface close to a point or line, also the contact area with the skin with possible follow complex motion in a state in which the top portion is in point contact with the skin It is extremely small and has good wearability and a good texture with a cloth-like feel such as peach skin and silk satin.

These effects cannot be obtained with a conventional surface material having a uniform three-dimensional opening in a continuous plane. To further elaborate the above-mentioned action, since it has a large number of apexes composed of convex curved surfaces that do not form a continuous plane, the contact area when contacted with the body becomes extremely small, which may impair the physiological function of the skin. Absent. Further, even when the liquid is excreted, the liquid does not stay on the body side even if it is a hydrophobic film because the contact area is not so small, and the liquid has a dry feeling. In addition, since each of the above-mentioned holes has the above-mentioned communication hole structure, the holding space of the liquid is substantially increased when the surface material is actually used, and the liquid is effectively absorbed even when a large amount of liquid is excreted. It can be transmitted to the body and absorbed from any direction.

These are essentially different from the conventional open-hole form of the hydrophobic film which has been conventionally proposed (the proposal that the tapered capillary tube or the cylindrical wall portion is vertical, etc.), and does not form a continuous flat surface. The convex curved surface is superior to the conventional ones in that the liquid retains on the body side and the transmissivity is accompanied by the excretion of a large amount of liquid. That is, in actual use, it is used under stress, 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.

[0014]

【Example】

(Example of Surface Material) First, an 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
1 shows an embodiment of the surface material of the absorbent article of the present invention.
FIG. 2 is a perspective view showing a cutaway part of an 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 the absorbent article of the present invention, and FIG. 2B is a partially enlarged plan view of the surface material according to the present embodiment, and FIG. 2B is a partially enlarged perspective view of the surface material shown in FIG.
FIG. 3C is a partially enlarged perspective view of the surface material shown in FIG. 2A when viewed from the back side, and FIG. 3 shows a metal knitting as a surface material molding die used for manufacturing the surface material of the absorbent article of the present invention. Three
FIG. 3A is an enlarged plan view of metal knitting, and FIG. 3B is an enlarged perspective view showing a part of the wire mesh further enlarged. FIG. 4 is a partially enlarged cross-sectional view of a part of an embodiment of the surface material of the absorbent article of the present invention,
4 (A), (B) and (C) show typical cross-sectional shapes of the holes together with the wire rod positions of the mold during molding of the surface material. FIG. 5A is a side view of the surface material when a flat plate is pressed from above, FIGS. 5B to 5E are plan views of the top surface of the surface material where the flat plate is pressed, FIG. 5B shows no load, and FIG. 5C shows a low load. Fig. 5D is for medium load, Fig. 5E
[Fig. 4] is a plan view under high load.

The surface material 1 shown in FIG. 2 according to this embodiment is
A surface material that covers the surface of the absorbent body 2 of an absorbent article including the absorbent body 2, is made of a liquid impermeable material, has a large number of holes P, and has holes for liquid transmission formed in the holes P. Specifically, the surface material is a melted resin, and a right-handed or left-handed same-direction spiral woven wire mesh 7 (see FIGS. 3A and 3B).
Is formed into a sheet shape having a shape along the surface shape and having the hole portion at a position corresponding to the space between the wire rods of the spiral braided wire net 7. That is, the surface material 1
2A and B, as shown in FIG.
(See FIG. 3) A large number of tops 3 formed in a shape that conforms to the surface shape of the wire rod located at the top of the wire rod without a continuous flat surface consisting of convex curved surfaces having voids on the back side, and a spiral braided wire mesh No. 7, a large number of aperture bottoms 4 formed by being dropped into the space between the wire rods, and the spiral braided wire netting 7 being formed between the wire rods, formed into an inclined curved surface shape or a stepped curved surface shape,
Each of the holes P has an adjacent curved wall 5 that connects the top 3 and the aperture bottom 4, and each of the holes P includes four adjacent tops 3 and one aperture bottom. 4 and one of the cylindrical wall portions 5 connecting them, each having a communication hole structure in which a communication hole is formed from the space between the tops 3 to the opening bottom 4. The transmission opening 6 is formed by the opening bottom portion 4.
It should be noted that, in drawing, the drawings do not necessarily show the actual shapes accurately, and this is remarkable particularly in FIG. 2C (also in FIG. 6C).

As shown in FIG. 4, each of the holes P has a base H ₀ which is the closest part to the top 3 at the opening edge of the hole bottom 4 (the opening 6) of each hole P. , The length from the base H ₀ to the highest portion H ₁ of the top portion 3 (this length is the vertical distance in the thickness direction of the surface material) = L ₁
And the length from the base H ₀ to the farthest portion H ₂ of the opening edge from the top portion 3 (this length is the vertical distance in the thickness direction of the surface material) = L ₂ (L ₂ / L _The structure is such that ₁ ) is less than 0.5.

In this embodiment, the holes P are adjacent to each other.
It is formed by one of the tops 3, one of the perforated bottoms 4 and one of the tubular walls 5 connecting them. Furthermore, the top portion 3 has a dot-like or linear shape when no load is applied.
The contact surface has a shape, and when loaded, the contact surface has an elliptical outer circumference according to the load. In the production of the surface material, the tubular wall portion can be obtained by appropriately selecting the resin composition and the production conditions such as the viscosity at the time of melting of the resin, the direction of vacuum suction, the direction of pressure flow pressurized from the side opposite to the suction. It is also possible to form the shape of the above-mentioned "spiral shape" corresponding to the shape of the above-mentioned spiral braided wire mesh 7.

The liquid impermeable material (hydrophobic sheet) constituting the surface material 1 is a polyolefin, a copolymer of olefin and an acrylic ester, another vinyl monomer such as vinyl acetate, polyester, Examples include hydrophobic thermoplastic resins such as polyamides alone or blends, and blends with hydrophilic resins such as polyvinyl alcohol and 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. The liquid impermeable material is preferably opaque. According to the surface material 1 of the present embodiment, the shapes of the top portion 3, the hole bottom portion 4 (the opening 6) and the curved tubular wall portion 5, and the shape and position of the communication hole formed by them, etc. With this structure, the color of liquid such as blood and urine absorbed in the absorbent body 2 can be shielded, but it is more preferable that the liquid impermeable material itself is opaque from the viewpoint of shielding property. Various means are conceivable 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, as shown in FIGS. 2B and 5, 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 also after absorbing the liquid. The amount of liquid retained in the body is extremely reduced to give a substantially dry feeling, and it is more preferable to add micro unevenness to the top. This micro-roughening is performed 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 by molding the surface material, or by post-processing by pressing, polishing, electric discharge treatment, etc. after molding the surface material. To be done. It can also be obtained by adding the above-mentioned inorganic filler and high-melting point organic material particles. Next, in FIG.
With reference to FIG. 5, the hole P of the surface material 1 of the present invention and the hole P
For a preferred shape of the opening bottom portion 4 (opening 6) in it will be described.

Each hole P of the surface material 1 of the embodiment shown in FIG.
Each is shown in FIG. 4 as (A), (B) and (C).
It has a cross-sectional shape as shown in FIG.
The cross section of P has the surface material 1 formed by the wire rods 7a, 7
Shown with b. In (A), the mold wire rods 7a and 7b are
Both sides show cross sections located at the top, (B) shows
Showing cross sections where the wire rods 7a and 7b are located at different heights,
(C) is when the wire rods 7b, 7b are at the lowest position on both sides
The cross section of FIG. And each of the holes of the surface material 1
As shown in FIG. 4, the part P has the basis H₀From above 3
Highest part of H₁Up to length L₁And the basis H₀Farthest from above
Part H₂Up to length L₂Ratio with (L₂/ L ₁) Is 0.5
The structure is less than. In addition, each hole P is
As shown in FIG.
Closest part to the top 3 at the opening edge of the mouth 6)
Base H₀And the basis H₀From the highest of the above 3
Part H₁Up to (the length in the thickness direction of the above surface material
Vertical distance) = L₁And the basis H₀From the opening edge above
The furthest part H from the top 3₂Up to (this length
Is the vertical distance in the thickness direction of the surface material) = L₂Ratio with
(L₂/ L₁) Is less than 0.5.

The above L ₁ is preferably set in the range of 0.05 mm to 2 mm, and particularly preferably in the range of 0.2 to ₁ mm. The distance L between the tops is 0.05.
It is preferable to set in the range of up to 5 mm, especially 0.2
It is more preferable to set in the range of 2 mm. Shape is of the top 3, as shown in FIG. 5A, the surface material 1 of this embodiment
When the flat plate Y is pressed from above, the peripheral length of the shape Z of the surface where the top portion 3 contacts the flat plate Y is 0.5 according to the load.
0.1mm~5mm when the g / cm ² load, 0.3Mm～15mm is preferred when the 50 g / cm ² load.

As described above, the shape of the hole P is different in the vertical cross section arbitrarily cut in the vertical direction in the thickness direction passing through the central portion of the hole P. The perimeter of the opening bottom 4 (peripheral length of the opening edge of the liquid permeation opening 6) is 0.1.
mm to 15 mm is preferable, and 0.5 mm to 10 mm is more preferable. The opening area of the opening bottom 4 is 0.02 mm ^{2 to} 9 mm.
It is preferably ² . If the opening area is smaller than 0.02 mm ² , the liquid permeability is poor, and if it is larger than 9 mm ² , the liquid returning property is poor. Space between the top 3 (the number of holes P per unit area of the surface material) opening density of the (opening) is preferably in two / cm ² to 100 pieces / cm ^2. When the opening area of the opening bottom portion 4 is small and the opening density (hole forming density) is small, the liquid permeability is substantially inferior, and when the opening area is larger than 9 mm ² , the liquid return prevention property is inferior. Because. Therefore, in consideration of these circumstances, the circumferential length and the opening density of the opening edge portion of the opening bottom portion 4 are set. The area (opening area) of the space between the tops 3 is usually substantially larger than the opening area of the open bottom 4. A backing material 8 is provided on the back surface of the absorbent body 2 of the absorbent article shown in FIG. 1 to cover the back surface and prevent liquid leakage.

Next, the function and effect 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 structure of the communicating hole of the hole P, and the top 3 is deformed due to the variation of the mounting pressure to increase or decrease the contact area with the skin, and the curved tube. Combined with the constricted shape of the wall portion 5, it works to promote the transfer of blood, urine, etc. to the absorber 2 side, like the transfer of food by the peristaltic movement of the esophagus. Further, this effect is remarkable in a viscous liquid, and is greatly different from the effect of a conventional surface material having a uniform three-dimensional opening in a continuous plane.

Further, the surface material 1 is deformed so as to close the opening bottom portion 4 (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 is released. As 6 opens, it returns to its original shape.
That is, the surface material 1 has the liquid permeation opening 6 only when a large force is applied when the absorbent article is attached (only when a force that returns the liquid once absorbed to the absorber 2 is applied to the skin side). It is closed so as to reliably prevent the liquid from returning from the absorber 2 to the skin side.

By setting the hole portion P formed by the top portion 3, the cylindrical wall portion 5 and the hole bottom portion 4 and the communication hole structure of the hole portion P to the above-mentioned shape, substantially high elasticity can be obtained. Even if a material with a high modulus is used, the elasticity and compression elasticity are excellent, and since the shear yield stress is small, the shear force is small in any direction along the surface of the surface material 1, and the top portion 3
The surface material 1 can follow the complicated movements of the wearer while being in point contact with the skin, and does not cause sticking or discomfort even if the surface material 1 comes into close contact with the skin without causing a mounting deviation.

6A-C show a surface material 10 according to another embodiment.
Is shown. This surface material 10 has a shape that follows the surface shape of a spiral braided wire net 70 (see FIGS. 7 and 7B) in which molten resin is wound right-handed and left-handed alternating spirals are connected by force bones (rods), and Braided wire mesh 7
It is formed into a sheet having holes P at positions corresponding to the holes P between the 0 wire rods. Therefore, the surface material 10
Similar to the surface material 1, is a plurality of tops 30 each having a convex curved surface having voids on the back side and a plurality of open bottoms 40, which do not have continuous planes, the tops 30 and the openings. It has a cylindrical wall portion 50 that connects the hole bottom portions 40 (liquid permeation openings 60), respectively, and has a communication hole structure similar to that of the surface material 1 and also has a similar hole portion P. That is, the surface material 10 is configured substantially the same as the surface material 1 except that the shape of the top portion 30 is partly different, and has the same effect as the surface material 1.

(Example of Method for Manufacturing Surface Material) Next, an example of a method for manufacturing the surface materials 1 and 10 according to the above-mentioned embodiment will be described with reference to FIG.

FIG. 8 is a process explanatory view showing an embodiment of the method for manufacturing a surface material of the present invention, and FIGS. 8A to 8E are views showing each process. The manufacturing method of this embodiment is
The surface materials 1 and 10 are manufactured by melt-molding a thermoplastic resin, and a spiral knitting wire net 7 shown in FIGS. 3A and 3B or a spiral knitting wire net 70 shown in FIGS. 7A and 7B is used as a surface material molding die. It

The material of the spiral braided wire nets 7 and 70 is preferably metal because it requires toughness and cooling properties for solidifying the molten resin. In addition to the spiral woven wire nets 7 and 70, a spiral woven wire net using a plurality of twisted wires, a spiral woven wire net using uneven wire rods, and a spiral woven wire net in which wires of different thicknesses are combined are cited. To be

According to the manufacturing method of this embodiment, the sheet-shaped molten resin 9 (see FIG. 8A) as the surface material molding resin is
For example, the sheet-like molten resin 9 is supplied from the upper part of the spiral braided wire net 7 while being vacuumed from the lower part of the spiral braided wire net 7 so that the sheet-shaped molten resin 9 is spread along the surfaces of the wire rods 7a and 7b of the spiral braided wire net 7. The spiral braided wire netting 7 is arranged, cooled and solidified by the wire rods 7a and 7b, and has a shape along the surface shape of the spiral braided wire mesh 7 having a hole P at a position corresponding to the space between the wire rods of the spiral braided wire mesh 7. I am trying to mold it.

To explain this in detail, as shown in FIG. 8A, the sheet-shaped molten resin 9 is supplied from the upper portion of the spiral braided wire net 7 through a T die (not shown), while the vacuum is fed from the lower portion of the spiral braided wire mesh 7. When inhaled, first see Figure 8B.
As shown in FIG. 4, the sheet-shaped molten resin 9 contacts with the uppermost wire 7a of the spiral braided wire net 7 to be cooled and solidified (this portion becomes the top), and then the sheet-like melted portion of the portion which does not contact the wire 7a is melted. As shown in FIG. 8C, the resin 9 is deformed by receiving a vacuum suction force, is in contact with the lower wire 7b, and is cooled and solidified (this portion becomes the top wall / cylindrical wall portion 5 connecting the tops). Thereafter, the sheet-shaped molten resin 9 in the portion which does not contact the lower wire 7b is deformed as shown in FIG. 8D and is solidified by air cooling.
As shown in FIG. 8E, the opening bottom portion 4 (liquid permeation opening 6) is formed by being spread and broken. 8A to 8E show the shape of the cut surface viewed from one direction passing through the center of the hole (see FIG. 4B). As described above, the wire material of the spiral braided wire mesh is shown in FIG. 2A, FIG. 2B, FIG. 5A, and FIG. 7a and 7 as shown in 5B
The position of b is up and down, and when it is separated left and right, it approaches and intersects 7
The a and 7b are vertically inverted, and the cylindrical wall portion forming one hole P has a continuously deformed shape corresponding to the shape of the spiral braided wire net 7. Moreover, although the top is almost near the point, the front and back, and the left and right descend in a curved shape.

By using the spiral braided wire net 70 as shown in FIGS. 7A and 7B, the surface material 10 having the shapes shown in FIGS. 6A to 6C can be molded. Further, as the surface material molding resin, instead of the molten resin 9 supplied from the T die,
A film may be used. In this case, the film is preheated to be softened and supplied to the spiral knitting wire net 7, or the film is heated and softened after being supplied to the spiral knitting wire net 7, or both are used in combination. It is formed by softening by the method described above and vacuum suction. Further, it is possible to form not only by vacuum suction but also by vacuum suction while supplying a heating flow from the vacuum suction side and the opposite side of the spiral braided wire net 7 (outside of the film). Furthermore, during the molding of the surface material by the above-mentioned method (before demolding) and / or after the manufacture (after demolding), the part from the base to the farthest part of the opening edge from the top part (L ₂ part) is re-formed. A preferable shape is obtained by shrinking by heating (or reheating the surface material from the bottom side of the opening). That is, when the L ₂ portion is long, the bottom of the aperture (the liquid permeation opening) is closed by the pressing force during wearing, and the liquid permeability decreases. In the melt vacuum suction molding method (this manufacturing method), L ₂
Since the portion is stretched, the stretched L ₂ portion shrinks and deforms during post-processing and storage, but does not shrink by performing this step (reheating).

The surface material of the absorbent article of the present invention is not limited to the manufacturing method thereof, but is also limited to the one formed by using the spiral braided wire nets 7 and 70 as the surface material forming mold. Instead, for example, it may be manufactured using a ceramic material or a surface material molding die having another shape .

Next, a more specific example of the above-mentioned embodiment (embodiment of the method for manufacturing a surface material) will be described. As the spiral braided wire net 7, a 26-mesh wire net (SP-26-0.35 manufactured by Kansai Wire Net Co., Ltd.) having a wire diameter of 0.35 mm and consisting of spirals in the same direction was used, and as the sheet-shaped molten resin 9, TiO 2 was used. the L-LD-PE molten resin containing _25%, while supplying a T die to provide 25 g / cm ^2, a vacuum nozzle from the lower (opposite side of the molten resin feed side) of the spiral braided wire mesh 7 After vacuum suction,
A sheet (surface material 1) having the same number of hole portions P and opening bottom portions 4 (liquid permeation openings 6) as the mesh number of the wire mesh and having a shape corresponding to the surface shape of the spiral knitted wire mesh 7 was formed. L ₂ / L ₁ of this sheet is 0.29 mm / 0.6
It was 0 mm = 0.48. Before demolding this sheet, the sheet was reheated to 120 ° C. with a far-infrared heater from the back side of the sheet while applying a gentle suction flow, and then cooled and demolded. L ₂ / L ₁ = 0.05 / 0 0.58 mm =
Surface material 1 of 0.86 was molded.

When a sanitary napkin was manufactured using the surface material 1, it was superior in absorbability, had a dry feeling, and had a weak wearing pressure, as compared with a sanitary napkin using a conventional surface material. The fit was good following the movement of the wearer, and it was a pleasant one that did not give a feeling of strangeness.

[0036]

EFFECTS OF THE INVENTION The surface material of the absorbent article of the present invention has liquid permeability that allows liquid to freely migrate, and also has a liquid return preventing property and a liquid that prevent the liquid once absorbed from returning to the skin side. In addition to the dry property that does not stay on the skin, the wearability that does not make the user feel uncomfortable when wearing it, and the shielding property that hides the color of the absorbed liquid so as not to appear on the surface, it has the various effects described above. Further, according to the method for manufacturing a surface material for absorbent articles of the present invention, a surface material having the above effects can be efficiently manufactured.

[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. 2A is a partially enlarged plan view of the surface material according to this embodiment, and FIG. 2B is a front surface side of the surface material shown in FIG. 2A. FIG. 2C is a partially enlarged perspective view of the surface material shown in FIG. 2A as seen from the back side.

FIG. 3 shows a wire mesh as a surface material molding die used for manufacturing the surface material of the absorbent article of the present invention, FIG. 3A is an enlarged plan view of gold knitting, and FIG. 3B is an enlarged perspective view of FIG. 3A. It is a figure.

FIG. 4 is a perspective view showing a cross section of one hole of a surface material according to the present embodiment, and FIG. 4A is a wire rod 7a of a mold;
7b shows a cross section with the uppermost part on both sides, and FIG. 4B shows
Shows cross sections where the wire rods 7a and 7b on both sides are located at different heights.
However, in FIG. 4C, the wires 7b, 7b are located at the lowest position on both sides.
The cross section is shown in FIG.

5 shows an embodiment of the present surface material, FIG. 5A is a side view when the surface material is pressed by a flat plate from above, and FIG.
6A to 6E are outer peripheral shape diagrams of the contact surface where the top of the surface material contacts the flat plate. 5B shows no load, FIG. 5C shows low load, FIG. 5D shows medium load, and FIG. 5E shows high load.

6A to 6C show another embodiment of the surface material, and FIG.
6A is an enlarged plan view of a surface material according to another embodiment, FIG. 6B is a partially enlarged perspective view when the surface material shown in FIG. 6A is viewed from the surface, and FIG. 6C is a surface material shown in FIG. It is a partial expansion perspective view at the time.

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

8A, 8B, 8C, 8D and 8E are process explanatory views showing an embodiment of the method for manufacturing a surface material of the present invention.

[Explanation of symbols]

1, 10 Surface material P hole portion 2 Absorber 3, 30 Top portion 4, 40 Opening bottom portion 5, 50 Cylindrical wall portion 6, 60 Liquid permeation opening 7, 70 Surface material molding die (spiral braided wire mesh) 7a, 7b Wire material 8 Back material 9 Surface material molding resin (sheet-shaped molten resin) Y Flat plate Z Perimeter of contact surface of surface material L ₁ Base (H ₀ ) to maximum part (H ₁ ) Length L ₂ base (H Length from ₀ ) to the furthest part (H ₂ )

─────────────────────────────────────────────────── ─── Continuation of the front page (72) Minoru Nishinishi Minoru Nakanishi 3298-75 Yakushiji, Minamikawachi-cho, Kawachi-gun, Tochigi Prefecture (56) References JP-A-62-57551 (JP, A) JP-A-64-64655 (JP, A) ) JP-A-1-292104 (JP, A) JP-A-60-177900 (JP, A) JP-A-58-1517 (JP, A) JP-A-2-198551 (JP, A) (58) Field (Int.Cl. ⁷ , DB name) A61F 13/00-13/84

Claims (4)

(57) [Claims] 1. A surface material for covering the surface of the absorbent body of an absorbent article having an absorbent body, which is made of a liquid impermeable material, has a large number of holes, and has a liquid permeation opening in the holes. In the formed surface material, the surface material has a large number of tops formed of convex curved surfaces having voids on the back side, a large number of aperture bottoms, and a tubular shape that connects the tops and the aperture bottoms, respectively. A wall portion, and the top portion has a dotted or linear shape when there is no load.
Presents a contact surface that, when loaded, has an elliptical outer circumference that corresponds to the load.
Exhibits a contact surface having, each hole has a plurality of said top adjacent, each formed from a single of the tubular wall portion for connecting them with one of the apertures bottom, by the open hole bottom Comprising the liquid permeation opening, consisting of a communication hole structure, further, each hole portion consisting of the communication hole structure, when the base of the most recent portion of the opening edge of the opening bottom portion to the top, The length from the base to the highest part of the top (this length is the vertical distance in the thickness direction of the surface material) = L ₁ and the length from the base to the farthest part of the opening edge from the top ( A surface material of an absorbent article, characterized in that this length has a structure such that a ratio (L ₂ / L ₁ ) of the surface material to a vertical distance in the thickness direction) = L ₂ is less than 0.5. 2. The farthest portion of the opening edge is
The surface material of the absorbent article according to claim 1, which is substantially equal to the lowest part of the hole. 3. The method for manufacturing a surface material for an absorbent article according to claim 1, wherein the surface material forming resin is supplied to one surface portion of a surface material molding die made of a spiral knitted wire net , Vacuum suction is performed from the other surface of the molding die, and the surface material forming resin has a shape along the surface shape of the surface material molding die and is placed at a position corresponding to the space between the wire rods of the wire mesh. A method for producing a surface material of an absorbent article, comprising forming a sheet having holes. 4. The method for producing a surface material for an absorbent article according to claim 1, wherein the surface material is reheated during molding (before demolding) and / or after manufacturing (after demolding). The method for manufacturing an absorbent article according to claim 3, wherein the hole portion is contracted from the base to the lowest portion.