JP2002238949A - Absorbable article - Google Patents

Abstract

PROBLEM TO BE SOLVED: To solve such a problem that the leak preventing wall provided to a conventional sanitary napkin can develop a function for pushing back a liquid much to a certain degree but a small amount of the liquid is liable to stagnate and flow out to the outside from the leak preventing wall. SOLUTION: The leak preventing wall 5 of the sanitary napkin is constituted so that an inner surface region 5A becoming a skin contact surface is formed of a hydrophilic sheet 6 and an outer surface region 5B is formed of a hydrophobic sheet 7. The liquid much to a certain degree and flowing through a surface layer 4 in a lateral direction is pushed back to an absorbing layer 3 side by the hydrophobic sheet 7. A small amount of the liquid flowing along the skin is held by the hydrophilic sheet 6 to be prevented from flowing out toward a side edge 11.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a sanitary napkin for absorbing excretions such as menstrual blood, or an absorbent article such as a disposable diaper or urine absorbing pad. It relates to the provided absorbent article.

[0002]

2. Description of the Related Art Absorbent articles such as sanitary napkins, disposable diapers, and urine absorbing pads have a liquid-impermeable back layer, a liquid-permeable front layer, the back layer and the front surface. And an absorbing layer provided between the layers.
In addition, some of the absorbent articles have a leakage-preventing wall that is located on both sides in the horizontal direction on the liquid receiving side surface of the main body and extends in the vertical direction of the main body.

In a conventional absorbent article, the leak-proof wall is formed of a hydrophobic non-woven fabric mainly composed of hydrophobic synthetic fibers. An elastic member extending in the vertical direction is attached to the leak preventing wall, and a longitudinal elastic contraction force acts on the leak preventing wall by the elastic member, and the main body is bent by the elastic contraction force. As a result, the leak-proof wall rises from the surface of the main body.

[0004] In the absorbent article, liquid such as menstrual blood and urine applied to the surface layer penetrates the surface layer and is absorbed by the absorbent layer. At this time, when the liquid applied to the surface layer exceeds the amount of the liquid permeating the surface layer, the liquid travels along the surface of the surface layer to reach the leak-proof wall, and the liquid leaks through the hydrophobic leak-proof wall. The liquid is pushed back to the inside of the main body, and the pushed back liquid permeates the surface layer and is absorbed by the absorbing layer. In a conventional absorbent article, the above-mentioned operation is mainly used to prevent lateral leakage of liquid.

[0005]

However, since the leak-preventing wall is entirely hydrophobic, a large amount of liquid is given to the surface layer as described above, and the liquid flows at a certain flow rate on the surface of the surface layer. When the liquid reaches the leak-proof wall, the liquid can be pushed back. However, since the leak preventing wall itself does not have a liquid absorbing ability due to a capillary phenomenon, when a small amount of liquid adheres to the leak preventing wall, the liquid cannot be pushed back to the surface of the absorbing layer.

For example, since a relatively small amount of liquid travels along the wearer's skin and reaches the leak-proof wall, this small amount of liquid cannot be returned to the surface side of the absorbent layer by the leak-proof wall, and It easily stays on the leaking wall. Then, the retained liquid may seep out between the skin and the leakage prevention wall and leak out of the leakage prevention wall.

In particular, when the leak-proof wall falls down to the side edge of the absorbent article due to the contact pressure with the skin and the material forming the flap outside the leak-proof wall comes into contact with the leak-proof wall, the small amount of Liquid easily leaks to the surface of the flap. As a result, sanitary napkins may cause underwear to be stained.

The present invention has been made to solve the above-mentioned conventional problems, and has a function of pushing back a large amount of liquid applied to the surface layer to the surface side of the absorption layer, and a small amount of liquid that can be transmitted through the skin. It is an object of the present invention to provide an absorbent article capable of preventing a liquid from seeping out of a leakage prevention wall.

[0009]

According to the present invention, there is provided a body having a liquid-permeable surface layer, a back surface layer, an absorbing layer located between the surface layer and the back surface layer, and a surface of the body. Absorbing walls located on both sides and extending in a longitudinal direction of the main body, at least a part of the leak preventing walls have a fixed end on the surface of the main body and a free end separated from the surface of the main body. In the sexual article, the leak-proof wall has an inner surface area facing the center line OO extending in the longitudinal direction of the main body and an outer surface area on the opposite side, and at least a part of the inner surface area. Is formed of a hydrophilic sheet, and a hydrophobic sheet is located in the outer surface area.

The free end of the leak preventing wall is directed toward a side edge of the main body, and a portion having a predetermined width starting from the free end of the leak preventing wall is formed on the surface of the main body. The skin contact portion extends obliquely or extends in parallel with the surface, and in the inner surface area, the hydrophilic sheet can appear at least at the skin contact portion.

Further, the hydrophilic sheet of the leak-proof wall has a structure in which two or more sheets are stacked, and the hydrophilic sheet is folded at the free end to form a structure in which two sheets are stacked. It may be.

Further, the case where the hydrophilic sheet has one sheet and the case where
In both of the case of the laminated structure, the hydrophilic sheet may have a higher hydrophilicity on the side in contact with the hydrophobic sheet than the hydrophilicity on the surface side of the inner surface area.

Further, the hydrophobic sheet may be folded back at the free end to the inner surface area, and the hydrophobic sheet may be overlaid on the surface of the hydrophilic sheet at the free end side of the inner surface area. Good.

Further, a flap is formed between the fixed end of the leak-proof wall and a side edge of the main body, and the flap is an extension of the back surface layer extending at least outside the absorbent layer; And an extension of the hydrophobic sheet forming the leak-proof wall extending outward from the fixed end.

In this case, a base end of the hydrophilic sheet forming the leak-proof wall extends from the fixed end toward the flap, and at least a part of the flap includes the hydrophilic sheet. May be located between the extension of the back surface layer and the extension of the hydrophobic sheet.

Further, the hydrophilic sheet forming the leak-proof wall may be formed by an extension of the surface layer extending from a region covering the absorbing layer.

For example, the hydrophilic sheet is a non-woven fabric having at least hydrophilic fibers. The hydrophobic sheet provided on the outer surface is preferably a plastic sheet having openings.

In this case, the plastic sheet is
It has a conduit extending toward the hydrophilic sheet, and the inside of the conduit is the opening, or the opening is formed so as to extend obliquely in the thickness direction of the plastic sheet. Can be used.

It is preferable that an elastic member that exerts an elastic contraction force in the vertical direction is attached to the leak-preventing wall, but it may not have an elastic member.

[0020]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below with reference to the drawings. FIG. 1 is a plan view showing a sanitary napkin 1 as an embodiment of the absorbent article of the present invention from the liquid receiving side, FIG. 2 is a cross-sectional view taken along the line II-II of FIG. 1, and FIG. FIG. 4 is an enlarged cross-sectional view showing a leak-proof wall portion of a napkin.
(A) and (B) are enlarged cross-sectional views showing a material forming a leak-proof wall, and FIG. 5 and subsequent figures are cross-sectional views showing an enlarged part of a leak-proof wall showing another embodiment.

The sanitary napkin 1 shown in FIGS. 1 and 2 comprises a back layer 2 facing an externally mounted body such as underwear, and an absorbent layer 3.
And a liquid-permeable surface layer 4 that covers the absorption layer. In the main body 1A, the absorbing layer 3 is provided in a region including a central portion and surrounded by a dotted line in FIG.

The lateral direction of the main body 1A is defined as an X direction in the drawing,
When the vertical direction is the Y direction, the main body 1A has side edges 11, 11 extending in the vertical direction on both sides in the horizontal direction. Further, the main body 1A has a front edge 12 directed toward the front of the body when worn and a rear edge 13 directed toward the rear of the body at both ends in the vertical direction. And the main body 1A
It has a symmetrical shape with respect to a center line OO extending in the vertical direction.

On both sides of the main body 1A, longitudinally extending leak-proof walls 5, 5 are provided equidistant from the center line OO. In the intermediate region indicated by La in FIG. 1, as shown in FIG. 2 and FIG.
However, the fixed end 5a is provided on the surface of the main body 1A, and the free end 5b can be raised so as to be separated from the surface of the main body 1A. In the front area Lb and the rear area Lc other than the intermediate area La, the entirety of the two folds is joined to the surface of the main body 1A in a state where the leak-proof walls 5 and 5 are folded in two. In Lb and the rear area Lc, the leakage preventing walls 5 and 5 do not rise. The longitudinal length of the intermediate region La is 30% to 70% of the longitudinal length of the main body 1A.

The back surface layer 2 extends to the positions of the side edges 11, 11 and the front edge 12 and the rear edge 13, and the plan shape of the back surface layer 2 is the same as that of the sanitary napkin shown in FIG. Match.

In the intermediate region La, a portion between the fixed ends 5a of the pair of leakage preventing walls 5, 5 is a main liquid receiving region 20. In addition, between the fixed ends 5a, 5a and the side edges 11, 11 in the intermediate region La,
In addition, flaps 21 and 21 are formed between the outer edges of the two-fold leakproof walls 5 and 5 in the front and rear regions Lb and Lc and the side edges 11 and 11.

As shown in FIG. 1, the flaps 21 and
1 is a shape that expands in the lateral direction in the rear area Lc,
In this portion, the side edges 11, 11 have a shape that forms a curved line and spreads in the horizontal direction. Further, in the intermediate region La, wings 21a, 21a are formed by protruding a part of the flaps 21, 21 to both outer sides in the lateral direction.

As shown in FIG. 3, the flaps 21 and
1 and the wings 21a, 21a, the extension 2a of the back surface layer 2 extends to the side edge 11 beyond the fixed end 5a as described above. The surface layer 4 also has an extension 4a extending laterally beyond the fixed end 5a, and the flaps 21, 21 and the outer end regions 2 of the wings 21a, 21a.
7, the extension 2a of the back layer 2 and the surface layer 4
Are bonded with a hot melt type adhesive or the like.

In FIG. 1, a front flap 22 is formed between the front edge 12 and the absorbent layer 3, and a rear flap 23 is formed between the rear edge 13 and the absorbent layer 3. Also in the front flap 22 and the rear flap 23, the extension of the back surface layer 2 and the extension of the surface layer 4 are adhered by a hot-melt adhesive.

As shown in FIG. 3, the leakage prevention side wall 5 has an inner surface area 5A facing the center line OO and an outer surface area 5B facing the side edge 11. The leak-proof side walls 5 on both sides are formed of a sheet joined body in which a hydrophilic sheet 6 and a hydrophobic sheet 7 are joined, and the hydrophilic sheet 6 appears on the inner surface area 5A and the outer surface area 5B. A hydrophobic sheet 7 appears.

The hydrophilic sheet 6 has an extension 6a extending from the fixed end 5a toward the side edge 11. The hydrophobic sheet 7 also has an extension 7a extending from the fixed end 5a to the side edge 11. And the flap 21
Now, the extension 4a of the surface layer 4 and the hydrophilic sheet 6
And the extension 6a of the back layer 2
And the extension 7 a of the hydrophobic sheet 7. Then, each of the extension portions 2a, 4a, 6
a and 7a are fixed to each other with a hot melt type adhesive. That is, the fixed end 5 a of the leak-proof wall 5 means an end of an adhesion region between the hydrophilic sheet 6 and the surface layer 4.

The flap 21 and the wing 21
In the outer end area 27a, only the hydrophobic back sheet 2a and the extension 7a of the hydrophobic sheet 7 are joined to each other with a hot melt adhesive, and the outer end area 27 causes the liquid to seep out. It is an area to prevent.

In the leak-proof wall 5, a plurality of elastic members 8a, 8b, 8c extending in the vertical direction are located substantially parallel to each other at the joint boundary between the hydrophilic sheet 6 and the hydrophobic sheet 7. The members are the hydrophilic sheet 6 and the hydrophobic sheet 7
And is joined to. Each elastic member 8a, 8b, 8c
Each of the elastic members 8a, 8b, 8c exerts an elastic contraction force on the leakage preventing walls 5, 5, which has a length extending over the entire length of the leakage preventing walls 5, 5. Due to this elastic contraction force, the main body 1A is curved so that the back surface layer 2 side becomes convex. As a result, in the intermediate region La, each of the leak-proof walls 5, 5 has its free end 5b separated from the main body 1A. Stand up.

In the front area Lb and the rear area Lc, the leak-proof wall 5 is folded in two and joined to the surface of the main body 1A, so that the leak-proof wall 5 in the intermediate area La
The cross section rises in a substantially V shape.

The leak-proof wall 5 is connected to the intermediate point 5 from the fixed end 5a.
c is the first wall portion 15, and the intermediate point 5
The second wall 16 extends from c to the free end 5b.
The first wall portion 15 mainly functions to push liquid flowing laterally on the surface of the surface layer 4 back to the absorption layer 3 side. FIG.
, The rising angle α of the first wall portion 15 with respect to the back surface layer 2 is less than 90 degrees. However, the angle α is approximately 9
At 0 degrees, the first wall 15 may rise substantially vertically, or α may exceed 90 degrees, and the first wall 15 may be inclined toward the side edge 11. .

In the second wall 16, the free end 5 b is directed toward the side edge 11. As a result, the second wall portion 16 has an angle β with respect to a horizontal line H parallel to the back surface layer 2.
It is inclined. Is greater than 90 degrees and 180
Degrees, and the second wall portion 16 is directed obliquely toward the side edge 11 or in a direction parallel to the back surface layer 2. And this 2nd wall part 16 is a main contact part with respect to a wearer's skin.

In the embodiment shown in FIG. 3, the hydrophilic sheet 6 appears on both the inner surface of the first wall 15 and the inner surface of the second wall 16.

The leak preventing wall 5 is separated from the fixed end 5a to the free end 5a.
The total length up to b is 10 to 60 mm, more preferably 20 to 40 mm. The intermediate point 5c
Is preferably in the range of 30 to 70% of the total length from the fixed end 5a to the free end 5b.

However, in the present invention, the leak preventing wall 5 extends obliquely in a substantially planar manner toward the side edge 11 in the entire width from the fixed end 5a to the free end 5b. May be a skin contact portion. Conversely, the leak-proof wall 5
Is bent at two or more intermediate points when viewed in its cross section, rises in a zigzag manner in a direction away from the surface of the main body 1A, and the free end 5b extends obliquely toward the side edge 11. Is also good.

In the embodiment shown in FIG. 3, the fixed end 5a is located on the surface layer 4 at a position deviating from the absorbing layer 3, but the fixed end 5a is located on the absorbing layer 3. It may be located on the surface of the surface layer 4. The distance between the fixed ends 5a of the leakage preventing walls 5 and 5 on both sides, that is, the width of the main liquid receiving area 20 is preferably 40 to 100 mm, and more preferably 40 to 80 mm. .

In the sanitary napkin 1, the liquid receiving area 2
At 0, the liquid applied to the surface layer 4 penetrates the surface layer 4 and is absorbed by the absorbing layer 3. However, a large amount of liquid is given to the surface layer 4, and the liquid permeates the surface layer 4 in any place of the liquid receiving area 20, more than the permeation flow rate of the liquid in the surface layer 4 (permeation amount per unit time) When the supply flow rate (supply amount per unit time) exceeds the above, the liquid cannot pass through the surface layer 4 and travels on the surface of the surface layer 4. When this liquid reaches the leak-proof wall 5, the liquid tends to be absorbed mainly by the hydrophilic sheet 6 in the first wall portion 15, but since this liquid has a certain flow rate, the outer The liquid pushed back to the absorbent layer 3 side by the hydrophobic sheet 7 in the area 5B,
The light passes through the surface layer 4 and is absorbed by the absorbing layer 3.

When the sanitary napkin 1 is worn, the second wall portion 16 mainly serves as a skin contact portion, and the hydrophilic sheet 6 located on the inner surface thereof contacts the skin. here,
Since a small amount of liquid is transmitted through the skin and is not an amount that is pushed back by the hydrophobic sheet 7, the small amount of liquid stays in a state of adhering to the inner surface area 5A of the leak-proof wall 5, or It easily stays between the inner surface of the second wall portion 16. However, this small amount of liquid permeates into the hydrophilic sheet 6 and propagates through the inside of the hydrophilic sheet 6 by capillary action, so that it is possible to prevent the liquid from staying and to prevent the liquid from leaking from the free end 5b. Can be prevented. Also, due to the contact pressure of the wearer's skin, the leak-proof wall 5 falls outward, and the free end 5b is
Even when it comes in contact with the top 1, since the hydrophilic sheet 6 has a liquid holding force, the liquid hardly oozes from the free end 5 b to the surface of the flap 21.

In the flap 21 outside the fixed end 5a of the leakage preventing wall 5, the extension 2a of the hydrophobic back layer 2
The extension 6a of the hydrophilic sheet 6 and the extension 4 of the liquid-permeable surface layer 4 are located between the extension 7a of the hydrophobic sheet 7 and the extension 7a of the hydrophilic sheet 6.
a is sandwiched. Therefore, even if the liquid absorbed by the absorbent layer 3 oozes out to the surface layer 4 due to the pressure of the wearer's skin,
This liquid is guided to the extension 4a in the flap 21 beyond the fixed end 5a by the capillary action in the surface layer 4, and at the same time, to the extension 6a of the hydrophilic sheet 6 located in the flap 21. Therefore, the liquid that has oozed out into the surface layer 4 due to the pressure with the skin can be diffused in the direction of the flap 21 and can be prevented from returning to the skin. However, in the outer end region 27, since the extension 2a of the back surface layer 2 and the extension 7a of the hydrophobic sheet 7 are joined, the liquid can be prevented from reaching the side edge 11.

In order to exert such diffusion prevention, the extension 4a of the surface layer 4 and the extension 6a of the hydrophilic sheet 6 are required.
It suffices that at least one of a extends into the flap 21.

Preferred examples of each material forming the sanitary napkin 1 of the present invention will be described below. The back surface layer 2 is formed of a liquid-impermeable sheet. The back layer 2 is a resin film, a gas-permeable resin film, a laminate of resin and paper, a sheet in which a nonwoven fabric and a resin film are laminated, and the like. Further, on the outer surface of the back layer 2, an adhesive layer for hooking to an externally mounted body such as underwear is provided, and a release paper for protecting the adhesive layer until use of the sanitary napkin is provided.

The absorbent layer 3 is made of cotton-like pulp, air-laid pulp, open-cell type hydrophilic foam, tissue paper, spunlaced nonwoven fabric using hydrophilic fibers, melt-blown nonwoven fabric subjected to hydrophilic treatment, or superabsorbent polymer. For example, a fibrous superabsorbent polymer and a foam superabsorbent polymer. Or you may comprise combining these.

The surface layer 4 is a liquid-permeable sheet,
Nonwoven sheet mainly composed of hydrophobic fiber, nonwoven sheet mixed with hydrophobic fiber and hydrophilic fiber, or perforated nonwoven sheet with many holes formed, continuous fiber defibrated from fiber bundle (tow) Is a layer having a predetermined thickness, a perforated film, an open-cell foam sheet subjected to hydrophilic treatment, or a combination thereof.

The hydrophilic sheet 6 provided on the inner surface area 5A of the leak-proof wall 5 is, for example, a nonwoven fabric sheet. Further, an apertured nonwoven fabric having a large number of holes formed therein to facilitate liquid introduction into the sheet may be used. The perforated nonwoven sheet is formed by fibrillating fibers by needling the holes, and has a high fiber density around the holes. It becomes easy to absorb by the capillary action of the surrounding high-density fiber. Considering the durability of the hydrophilic sheet 6 for forming the leak-proof wall 5 and the effect of the capillary action, the opening area of one hole is 0.19 to 1.76 mm ² and the hydrophilic sheet is It is preferable that the area ratio of the hole in No. 6 is about 5 to 35%.

The hydrophilic sheet 6 has the ability to absorb and retain liquid by capillary action, and its constituent fibers are PE / PP, PE / PET, EVOH / PE.
T, or composite fibers such as EVA / PP, PP, PET,
It is a single fiber such as PE or graft polymerization of PE and PP. Further, it is preferable that these hydrophobic fibers have been subjected to a hydrophilic treatment on the surface. Alternatively, the hydrophilic sheet 6 may be formed of hydrophilic fibers of natural cellulose or regenerated cellulose such as viscose rayon, acetate rayon, or natural cellulose fiber. Alternatively, it may be formed by combining any one of the hydrophobic fiber and the hydrophilic fiber. The fineness considers the feeling of wearing and the effect of the capillary phenomenon,
A range of 1.1 to 4.4 dtex is preferred.

The hydrophilic sheet 6 has a fiber structure that is different from that of the surface of the surface of the inner surface area 5A of the leak-preventing wall 5 and that of the back surface joined to the hydrophobic sheet 7 in the structure of the sheet itself. You can use what you have. For example,
The surface portion of one hydrophilic sheet is formed only of fibers that have been subjected to hydrophobic treatment with silicone oil or the like, or is formed by including fibers that have been subjected to hydrophobic treatment, and the back portion is formed of hydrophilic fibers or hydrophilic fibers. It is preferable to form only the hydrophobic fiber which has been subjected to the hydrophilic treatment, or to form the hydrophilic fiber containing 5 to 30% by mass.

Alternatively, the hydrophilic sheet 6 is formed by laminating and partially joining two nonwoven fabrics, and the nonwoven fabric appearing on the surface of the inner surface area 5A of the leak-proof wall 5 is subjected to the above-described hydrophobic treatment. The non-woven fabric to be bonded to the hydrophobic sheet 7 may be made of hydrophilic fibers or only fibers subjected to hydrophilic treatment, or 5 to 30 fibers. It may be composed of a component containing the component by mass%.

As described above, when the hydrophilicity of the hydrophilic sheet 6 is made higher on the front side than on the rear side and higher on the rear side than on the front side, a small amount of the hydrophilic sheet 6 is given. Since the liquid is held on the back side of the sheet and the surface is in a dry state, the wearer is less likely to feel wet when the skin is in contact.

The hydrophilic sheet 6 is made of a point-bonded nonwoven fabric in which a fiber web is formed by a card method and fibers are fixed by heat sealing, a through-air nonwoven fabric in which hot air is applied to the fiber web to fuse the fibers, A spunlace nonwoven fabric or the like in which fibers are entangled by applying a water flow to a fiber web is used. In addition, a spunbonded nonwoven fabric or a meltblown nonwoven fabric obtained by heat setting continuous fibers formed of a thermoplastic resin to form a sheet, or a composite nonwoven fabric of spunbond and meltblown may be used.

Among the above nonwoven fabrics, preferred are through-air nonwoven fabrics which are bulky and easily form voids for liquid permeation in the sheet.

The basis weight of the nonwoven fabric is preferably in the range of ²⁰ to 100 g / m ² in the case of one sheet or two or more sheets. Further, in order to prevent the generation of fluff and tear due to friction during wearing, and to further improve the feeling of wearing, the breaking strength is 0.94 to 2.94 N per inch width in the weaker MD and CD. A range is preferred. The breaking strength was measured when the strength at break was measured with a tensilon tester at a chuck interval of 100 mm and a tensile speed of 100 mm / min, using a 1 inch width cut to a length of 150 mm as a sample. It is.

Further, the hydrophilic sheet 6 was obtained by defibrating a fiber bundle (tow) into a nonwoven material sheeted mainly with the composite synthetic fiber having a basis weight of 15 to 30 g / m ² . The continuous fiber layer having a basis weight of 30 to 150 g / m ² may be overlapped, and the continuous fiber layer and the nonwoven fabric material may be intermittently joined. The continuous fiber is a hydrophobic composite synthetic fiber, and preferably has a surface subjected to a hydrophilic treatment. The layer of continuous fibers is directed toward the wearer's skin. This layer has a high ability to hold bodily fluids,
The leak-proof wall 5 having a certain liquid holding power can be formed. Further, the continuous fiber layer has a cushioning property when it comes into contact with the skin.

In addition, as a material for forming the hydrophilic sheet 6, a foamed sheet having hydrophilic cells obtained by mixing or applying a hydrophilic agent to a resin such as PE or EVA and having open cells formed therein may be used. it can. The foamed sheet is also preferable because it has a feeling of bulkiness and also has a liquid holding power. The thickness of the foam sheet is in the range of 0.50 to 3.0 mm,
The expansion ratio is preferably in the range of 5 to 30 times.

As the hydrophobic sheet 7, a resin film or a nonwoven fabric formed of hydrophobic fibers subjected to a water-repellent treatment can be used, but a perforated plastic sheet having a large number of holes can be used. Is preferred. The perforated plastic sheet is preferable because it gives a soft feeling of wearing when the leak-proof wall 5 hits the skin because the sheet itself does not permeate the liquid and is soft. In addition, since the perforated plastic sheet has air permeability, the entirety of the leak-proof wall 5 has good air permeability, and it is difficult for the wearer to get stuffy.

The above-mentioned perforated plastic sheet is formed by extruding a film in a molten or softened state extruded from a die continuous with a melt extruder onto a screen drum, and applying a vacuum pressure from the inside of the screen drum to form the film. It is obtained by a manufacturing method in which it is formed along the opening shape of the screen and bursts. As a result, as shown in FIG. 4A, a large number of openings 7b are formed in the sheet forming the hydrophobic sheet 7, and a conduit 7c protruding to one surface side is formed around the opening 7b. You.

As shown in FIG. 4A, the conduit 7c is directed to the hydrophilic sheet 6, and the conduit 7c is attached to the hydrophilic sheet 6 with the hydrophilic sheet 6 and the hydrophobic sheet 7 bonded together. Penetrate inside the fibers that form Since the plastic sheet itself is hydrophobic,
In the opening 7b, almost no capillary action occurs, and the liquid between the fibers of the hydrophilic sheet 6 is hardly drawn out to the opening 7b. Further, since the conduit 7c and the opening 7b face the hydrophilic sheet 6 in a tapered state, when pressure is applied, the liquid in the hydrophilic sheet 6 does not easily seep into the opening 7b.

As shown in FIG. 4 (B), the apertured plastic sheet used as the hydrophobic sheet 7 has a center line of the aperture 7d of 20 to 6 with respect to a vertical line of the sheet surface.
It may be inclined within a range of 0 degrees. The perforated plastic sheet having the inclined perforations 7d also easily prevents the liquid from seeping out of the hydrophilic sheet 6 to the outer surface area 5B.
In both of FIGS. 4A and 4B, the opening preferably has a shape that tapers toward the hydrophilic sheet 6.

The opening area of one opening of the opening plastic sheet is 0.03 to 0.79 mm on the outer surface area 5B side.
² , the open area ratio of the hole is 30 to 70% on the outer surface area 5B side, and 10 to 10 on the hydrophilic sheet 6 side.
It is preferably in the range of 30%. When the thickness is within the above range, the leak-proof wall 5 has air permeability, and it is easy to prevent the liquid from leaking from the hydrophilic sheet 6 into the hole.

The arrangement of the holes may be a zigzag, lattice, geometric pattern, or the like, and the sizes of the holes may be individually different.

The resin raw material forming the perforated plastic sheet is an olefin resin such as PE or PP, a synthetic rubber resin such as urethane or SEBS, a random copolymer resin of PE and PP, or a hard component and a soft component. And a thermoplastic resin such as a polyester block copolymer resin of polyester as a hard component and polyether as a soft component. Or you may comprise combining these.

In consideration of the stability of the shape of the hole at the time of forming the hole, the density is 0.89 to 0.93 g / cm.
³ , and the melt flow rate is 2 to 30 g / m.
It is preferable to use a material selected from LDPE (low-density polyethylene) or LLDPE (linear low-density polyethylene) having a basis weight of 20 to 40 g / m ² .

As a plastic sheet constituting the hydrophobic sheet 7, an inorganic filler such as calcium carbonate, barium sulfate, silica, activated carbon, zeolite, talc, or a synthetic mineral filler is added to a resin such as LDPE or LLDPE. ６０60% by mass, and the whole was uniaxially or biaxially stretched, or subjected to a partial stretching treatment in the form of dots or lines to form fine voids between the filler and the resin. (Breathable).

As another material forming the hydrophobic sheet 7, a two-layer film is formed by extruding two layers of a polyolefin resin such as PE and a synthetic rubber resin, and the opening is formed in the two-layer film. May be done. For example, a film is formed so that the polyolefin-based resin layer is 10 to 80% by mass and the synthetic rubber-based resin layer is 90 to 20% by mass, and the polyolefin-based resin layer is formed on the surface of the outer surface area 5B side by a hydrophilic sheet. When the synthetic rubber-based resin layer is located on the side in contact with 6, the elasticity of the leak-proof wall 5 is improved, and the feeling of wearing when the leak-proof wall 5 touches the skin becomes a soft texture.

Further, 10 to 60% by mass of an inorganic filler is mixed with the two-layer co-pressed type polyolefin resin layer, and the inorganic filler is exposed on the surface of the outer surface area 5B, whereby the hydrophobic sheet 7 is formed. Can reduce the feeling of close contact when contacting the skin, and can improve the contact feeling of the skin. In this case, the average particle diameter of the inorganic filler is preferably in the range of 2 to 10 microns in order to increase the degree of surface exposure of the inorganic filler from the film surface. Furthermore, the plastic sheet constituting the hydrophobic sheet 7 may be provided with fine irregularities on the surface to reduce the degree of adhesion to the skin.

In the resin forming the plastic sheet, as a softening agent, for example, paraffin wax, ethylene glycol, fatty acid ester, etc.
A so-called plasticizer is mixed in an amount of 0.1 to 2.0% by mass.

The plastic sheet forming the hydrophobic sheet 7 is formed by mixing a water-producing agent such as silicon or fluorine in order to prevent the liquid from flowing out of the hydrophilic sheet 6 to the opening. Alternatively, it may be applied to the sheet surface.

Each of the elastic members 8a, 8b, 8c is made of a band-like film or thread material mainly composed of synthetic rubber, a band material or thread material obtained from natural rubber, or a sheet-like elastic material made of synthetic rubber. It is selected from a spunbonded nonwoven fabric, a material obtained by cutting a meltblown nonwoven fabric into a band, a material obtained by cutting a sheet-formed apertured film made of synthetic rubber as a raw material into a band, or a foam material made of synthetic rubber as a raw material. In addition, only one elastic member may be provided,
Four or more may be provided.

FIGS. 5 to 7 show another embodiment of the present invention, and are partial sectional views corresponding to FIG.

The points different from FIG. 3 in the embodiment shown in FIGS. 5 to 7 will be described. In the embodiment shown in FIG. 5, the hydrophobic sheet 7 is folded back at the free end 5b to the inner surface area 5A side, and a part of the second wall 16 serving as the skin contact surface on the free end 5b side has a hydrophobic surface. The hydrophilic sheet 7 is overlapped and joined to the surface of the hydrophilic sheet 6.

When a small amount of liquid absorbed by the hydrophilic sheet 6 tries to bleed to the free end 5b side by the contact pressure with the skin, the liquid is covered by the hydrophobic sheet 7 covering the free end 5b. Is prevented from leaking, and liquid leakage from the free end 5b to the outside can be prevented.

In the embodiment shown in FIG. 5, the end 7 of the hydrophobic sheet 7 folded from the free end 5b to the inner surface area 5A is formed.
The total length up to A is preferably in the range of 1 to 10 mm. Within this range, the second wall 16
The liquid leakage from the free end 5b can be prevented without impairing the ability to absorb a small amount of liquid in the inner surface area 5A and without causing the second wall portion 16 to have a rigid feeling.

In the embodiment shown in FIG. 6, the hydrophilic sheet 26 is folded at the free end 5b, and is joined to the hydrophobic sheet 7 in a state where the hydrophilic sheet 26 is folded in two layers. A leak-proof wall 5 is formed. The above 2
In the stacked hydrophilic sheets 26, two extending portions 26a and 26b extend from the fixed end 5a toward the flap 21. In the flap 21, in the region 24 having a predetermined width starting from the fixed end 5a, both the extension portions 26a and 26b of the hydrophilic sheet 26 are connected to the extension portion 4a of the surface layer 4 and the extension portion 7a of the hydrophobic sheet 7. It is sandwiched between. In the outer region 25, only one extension 26b is sandwiched between the extension 2a of the back layer 2 and the extension 7a of the hydrophobic sheet 7, and in the outer end region 28 outside the extension 26b, Only the extension 2a of the hydrophobic sheet 7 is joined to the extension 2a.

In this embodiment, in the region 24 which is a part of the flap 21, the two extensions 26 a and 26 b of the hydrophilic sheet 26 are located on the extensions 4 a of the surface layer 4. Therefore, the liquid flowing through the surface layer 4 is
Or when the wearer's skin is pressed against the absorbent layer 3
When the liquid oozing out of the surface layer 4 reaches the fixed end 5a, the liquid is absorbed by the two extended portions 26a and 26b, and the effect of preventing lateral leakage of the liquid can be enhanced.

In the embodiment shown in FIG. 7, an extension extending from the fixed end 5 a of the surface layer 4 covering the absorbing layer 3 is joined to the hydrophobic sheet 7. The extension of the surface layer 4 is folded back at the free end 5b, and the two sheet portions 4b and 4c are joined to the hydrophobic sheet 7 in a state where they are partially adhered to each other with an adhesive. . The seat portion 4c extends from the fixed end 5a outwardly.
The extension 4 d is sandwiched between the extension 2 a of the back layer 2 and the extension 7 a of the hydrophobic sheet 7 at a part of the flap 21. The extension of the surface layer 4 functions as a hydrophilic sheet located on the inner surface area 5 </ b> A of the leakage prevention wall 5.

In the embodiment shown in FIGS. 6 and 7, since the inner surface area 5A of the leak-proof wall 5 is formed of two hydrophilic sheets, the feel when hitting the skin is improved, and The ability to hold a small amount of liquid in the inner surface area 5A of the leakage prevention wall 5 is enhanced.

In each of the above embodiments, the inner surface area 5A is formed only on the second wall portion 16 which is the skin contact portion of the leakage preventing wall 5.
May appear, and a hydrophobic sheet may appear in the first wall portion 15 in the inner surface area 5A. With this configuration, the ability to push back the liquid toward the absorbent layer 3 in the inner surface area 5A of the first wall portion 15 increases, and the liquid stays between the inner wall region 5A of the second wall portion 16 and the skin. The ability to hold a small amount of liquid can be demonstrated.

The present invention can be applied not only to sanitary napkins but also to disposable diapers and urine absorbing pads for elderly care.

[0081]

As described above, in the absorbent article of the present invention, the liquid flowing in the lateral direction from the surface layer can be pushed back in the direction of the absorbent layer by the hydrophobic sheet of the leak-proof wall, and the skin can be removed. A small amount of transmitted liquid can be stopped by the hydrophilic sheet located on the inner surface area of the leak prevention wall, and can be guided into the hydrophilic sheet, preventing the liquid from leaking laterally and outwardly of the absorbent article. Function can be enhanced.

In particular, when a perforated plastic sheet is used as the hydrophobic sheet forming the leak-proof wall, the breathability of the leak-proof wall is not impaired, and the wearer does not feel stuffy.

[Brief description of the drawings]

FIG. 1 is a plan view showing a sanitary napkin from a liquid receiving side as an embodiment of an absorbent article according to the present invention;

2 is a sectional view taken along line II-II in FIG.

FIG. 3 is a partially enlarged cross-sectional view showing a leakage preventing wall of the sanitary napkin in FIG. 2;

4 (A) and 4 (B) are enlarged sectional views showing the structure of the leak-proof wall shown in FIG. 3;

FIG. 5 is a partially enlarged cross-sectional view showing another embodiment of the leakage preventing wall shown in FIG. 3;

FIG. 6 is a partially enlarged cross-sectional view showing another embodiment of the leakage preventing wall shown in FIG. 3;

7 is a partially enlarged cross-sectional view showing another embodiment of the leakage preventing wall shown in FIG. 3;

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Sanitary napkin 2 Back layer 2a Extension of back layer 3 Absorption layer 4 Surface layer 4a Extension of surface layer 5 Leak prevention wall 5A Inner surface area 5B Outer surface area 5a Fixed end 5b Free end 5c Intermediate point 6 Hydrophilic sheet 6a Hydrophilic Extension of hydrophobic sheet 7 Hydrophobic sheet 7a Extension of hydrophobic sheet 7b, 7d Opening 7c Conduit 8a, 8b, 8c Elastic member

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) A61F 5/44 (72) Inventor Hideki Kondo 1531-7 Takada, Wadahama, Toyohama-cho, Mitoyo-gun, Kagawa Japan Unicharm Corporation 3B029 BB05 BC05 BD12 4C003 CA01 CA04 CA06 4C098 AA09 CC08 CC10 CC12 CC37 DD10 DD16 DD19 DD22 DD24 DD25 DD26 DD30

Claims (14)

[Claims] 1. A body having a liquid-permeable surface layer, a back surface layer, and an absorption layer positioned between the surface layer and the back surface layer.
And a leakage barrier located on both sides of the surface of the body and extending in the longitudinal direction of the body, at least a portion of the leakage barrier has a fixed end on the surface of the body and a free end of the body. In the absorbent article remote from the surface, the leak-proof wall has a centerline OO extending in a longitudinal direction of the main body.
An inner surface area facing the side, and an outer surface area opposite to the inner surface area, at least a part of the inner surface area is formed of a hydrophilic sheet, and a hydrophobic sheet is located in the outer surface area. An absorbent article characterized by the following. 2. The free end of the leak preventing wall is directed toward a side edge of the main body, and at least a portion of a predetermined width starting from the free end of the leak preventing wall is formed on a surface of the main body. 2. The absorbent article according to claim 1, wherein the hydrophilic sheet is a skin contact portion extending obliquely with respect to or extending parallel to the surface, and in the inner surface area, the hydrophilic sheet appears at least on the skin contact portion. . 3. The absorbent article according to claim 1, wherein the hydrophilic sheet of the leak-proof wall has two or more overlapping structures. 4. The absorbent article according to claim 3, wherein the hydrophilic sheet is folded at the free end to form a two-ply structure. 5. The absorbent article according to claim 1, wherein the hydrophilic sheet has a higher hydrophilicity on the side in contact with the hydrophobic sheet than the hydrophilicity on the surface side of the inner surface area. 6. The hydrophobic sheet is folded back at the free end to the inner surface area, and the hydrophobic sheet is superimposed on the surface of the hydrophilic sheet at a portion of the inner surface area on the free end side. The absorbent article according to claim 1. 7. A flap is formed between a fixed end of the leak-proof wall and a side edge of the main body, the flap being an extension of the back layer extending at least outside the absorbent layer; The absorbent article according to any one of claims 1 to 6, wherein the absorbent article is formed by an extension of the hydrophobic sheet forming the leak-proof wall extending outward from the fixed end. 8. A base end of the hydrophilic sheet forming the leak-proof wall extends from the fixed end toward the flap, and at least a part of the flap extends the hydrophilic sheet. The absorbent article according to claim 7, wherein the overlapped portion is located between the extension of the back surface layer and the extension of the hydrophobic sheet. 9. The method according to claim 1, wherein the hydrophilic sheet forming the leak-proof wall is formed by an extension of the surface layer extending from a region covering the absorbing layer. Absorbent articles. 10. The absorbent article according to claim 1, wherein the hydrophilic sheet is a nonwoven fabric having at least hydrophilic fibers. 11. The absorbent article according to claim 1, wherein the hydrophobic sheet provided on the outer surface of the leakage preventing wall is a plastic sheet having openings. 12. The absorbent article according to claim 11, wherein the plastic sheet has a conduit extending toward the hydrophilic sheet, and the inside of the conduit is the opening. 13. The absorbent article according to claim 11, wherein the opening is formed so as to extend obliquely in a thickness direction of the plastic sheet. 14. The absorbent article according to claim 1, wherein an elastic member that exerts an elastic contraction force in the longitudinal direction is attached to the leakage preventing wall.