JPH02218368A - Physiology napkin - Google Patents

Abstract

PURPOSE:To improve the adhesiveness in the case when a slip-off preventing adhesive is used, by superposing the lip part of an impermeable sheet, side part of a surface sheet, and the lip part of a nonwoven fabric in succession and fixing at least the lip part of the impermeable sheet and the side part of the surface sheet. CONSTITUTION:A liquid-permeable surface sheet 1 and a nonwoven fabric 2 are fixed each other onto the both side edges of the surface sheet 1, except a part in the longitudinal direction of a napkin, by a hot melt type adhesive 3, and the above-described part is fixed by a heat embossing HE. The nonwoven fabric 2 surrounds an inside element, and inside the nonwoven fabric 2, a waterproof paper sheet 4 as liquid-impermeable sheet having a lip groove form is installed. A wave-shape cushion material layer 5 is fixed onto a bellows base sheet 6 on the lower side, and an absorbing body 8 consisting of cotton pulp surrounded by an absorbing paper 7 is installed under the base sheet 6, and a part of the absorbing paper 7 is superposed onto the undersurface. While, the perforated surface sheet 1 is fixed with the cushion member layer 5 by a hot melt adhesive 9, at the top part, and also the bellows base sheet 6 and the absorbing paper 7 are fixed by a hot melt adhesive 10.

Description

[Detailed description of the invention] [Industrial application field] The present invention relates to sanitary napkins.

[Conventional technology]

In recent years, as an improvement over the conventional sanitary napkins that mainly use cotton-like pulp as the absorbent element, absorbent materials made of cotton-like pulp have been developed to improve spot absorbency, absorption speed, surface stickiness, and wearing comfort. Providing a cushioning material layer on the body has been proposed, for example, in JP-A-62
This is known from, for example, Japanese Patent No.-125001.

In addition, as a napkin structure, in Japanese Patent Publication No. 5910222 and Utility Model Application No. 61-97629, etc., the side edges of a leak-proof sheet rolled up through the side of the absorbent body are overlapped on both side edges of the top sheet. It is known that napkins are bonded intermittently or continuously in the longitudinal direction of the napkin. Utility Model Publication No. 60=31718 also discloses a structure in which an absorbent body and a leak-proof sheet are entirely covered with a liquid-permeable sheet.

[Problem to be solved by the invention]

However, as a leak-proof sheet, a plastic film itself or a so-called polylaminated nonwoven fabric, which is a combination of a plastic film such as polyethylene and a nonwoven fabric, is usually used. When using the napkin, the adhesion of the anti-slip adhesive used to temporarily attach it to the shorts becomes poor. Therefore, it is preferable to use a polylaminated nonwoven fabric and to make the nonwoven fabric surface the outer surface.

However, when compared to simple nonwoven fabrics, polylaminated nonwoven fabrics are hard and do not have a very good feel.

Therefore, even if only the side edges are exposed as in Japanese Patent Publication No. 59-10222 and Utility Model Application No. 61-97629, as long as a portion touches the skin, the tactility is impaired. Although this latter technology contributes to improved tactility because the side edges of the leakproof sheet are wrapped in nonwoven fabric, it requires a nonwoven fabric that is wider than the width of the plastic film, which increases costs and requires special products. Therefore, it must be made in-house, which requires a separate process, which is not practical. Furthermore, when polylaminated nonwoven fabric is placed over the top surface of the top sheet and bonded with hot melt adhesive, either continuously or intermittently, the side edges themselves are not bonded, so when they are turned over, the side edges of the plastic film is exposed,
It feels bad (to have a bad feeling).

In view of these points, Utility Model Publication No. 60-31718 has excellent tactility because the entire body is wrapped with nonwoven fabric.

However, non-woven fabrics are not so cheap, do not have the best texture, and tend to cause menstrual blood to return.

As an improvement in this respect, it has recently been known to use a perforated plastic film as the top sheet of the napkin, as typically shown in Japanese Patent Publication No. 57-17081. The actual product using this technology is simply an absorbent body wrapped around all four sides with a perforated plastic film. Although this product is certainly superior in many ways,
The biggest drawback is that the product has a smooth feel when you hold it in your hand, as it is covered with plastic film all around. Furthermore, since the plastic film and the absorbent body are separated from each other, the absorbent body is likely to shift within the plastic film due to the movement of the wearer.

Moreover, as mentioned above, it is difficult to use an adhesive for preventing slippage.

Therefore, the main object of the present invention is to provide a sanitary napkin that has excellent tactility, is inexpensive, can use a perforated plastic film, and has excellent adhesive properties when using an anti-slip adhesive. It is about providing.

[Means to solve the problem]

The above-mentioned problem consists of an absorbent element, a perforated surface sheet having a large number of holes disposed above the absorbent element, a lip groove-shaped nonwoven fabric that wraps around the absorbent element and spans the lower surface, side surfaces, and upper side portions of the absorbent element; a hydrophobic cushioning material layer disposed between the topsheet and the absorbent element; a lip-groove-shaped liquid-impermeable sheet disposed between the nonwoven fabric and the absorbent element and spanning the lower, side, and upper sides of the nonwoven fabric; a lip portion of the liquid-impermeable sheet,
This problem can be solved by sequentially overlapping the side parts of the top sheet and the lip part of the nonwoven fabric and fixing them to each other.

Furthermore, it is preferred that a hydrophobic cushioning material layer is provided between the topsheet and the absorbent element.

[Effect]

In the present invention, the bottom surface of the absorbent element, excluding the top sheet,
It is covered with a lip groove-shaped nonwoven fabric that spans the side and top sides, and this nonwoven fabric comes into contact with the skin, so it has an extremely superior feel compared to plastic films and polylaminated nonwoven fabrics. Furthermore, since the lower surface (unused surface) of the napkin is made of nonwoven fabric, the adhesiveness of the anti-slip adhesive is good.

Furthermore, when a perforated plastic film or perforated nonwoven fabric is used as the top sheet, the spot absorption of menstrual blood and the effect of preventing backflow are superior to the case where a nonwoven fabric is used. Thus, the present invention can solve the problem that the tactility, the spot absorption of menstrual blood, and the anti-reversion effect are contradictory to each other.

Furthermore, even if the side edges of the nonwoven fabric are turned over, the nonwoven fabric itself comes into contact with the skin, so unlike when polylaminated nonwoven fabric is used, the side edges of the plastic film will not be exposed and damage the skin.

Moreover, in the present invention, since the cushioning material layer is provided, the cushioning properties are excellent. In conjunction with the perforated top sheet, this cushioning material layer exhibits remarkable menstrual blood spot absorbency and backflow prevention effect, as will be described later.

[Specific structure of the invention]

The present invention will be explained in more detail below.

Figures 1 to 3 show an example of the structure of a sanitary napkin as an absorbent article, in which 1 is a liquid-permeable top sheet, 2 is a nonwoven fabric, and except for a part in the longitudinal direction of the napkin, Both side rolls of the topsheet 1 are fixed to each other with a hot melt adhesive 3, and some portions are fixed by heat embossing HE. This nonwoven fabric 2
has a lip-channel shape in cross section and envelops the internal element as shown in the drawings.

Inside the non-woven fabric 2 is a waterproof paper 4, which also has a lip groove shape and serves as a liquid-impermeable sheet (leakproof sheet) according to the present invention, and its lip portions are located below both side edges of the top sheet l. There is. The waterproof paper 4 has an inner surface made of paper or nonwoven fabric and an outer surface made of a plastic film, and is, for example, what is known as a so-called polylaminated waterproof paper.

This waterproof paper 4 prevents absorbed menstrual blood from leaking to the outside.

Reference numeral 5 denotes a corrugated (concert-shaped) cushioning material layer, which will be explained in detail later, which is fixed to the bellows-shaped mount 6 below it.

Below this bellows mount 6, an absorbent paper 7 made of tissue or the like and an absorbent body 8 made of a cotton-like bulb surrounded by this paper are provided. The absorbent paper 7 is partially overlapped on its lower surface.

On the other hand, the top sheet 1 is made of a perforated or non-perforated nonwoven fabric or a perforated plastic film. As seen in the above-mentioned publication, the use of a perforated plastic film as a top sheet has recently been adopted in some sanitary napkins.

This topsheet 1 is fixed to the cushioning material layer 5 at its ridges using a hot melt adhesive 9. Both the bellows mount 6 and the absorbent paper 7 are fixed with a hot melt adhesive 10. Thereby, inclusions (internal elements) such as the cushioning material layer 5 and the absorbent body 8 are immobilized.

As is clear from the comparison with FIG. 1.2.3, a portion of the absorbent body 8 and the absorbent paper 7 are cut out narrowly to improve the fit (adhesion) to the local area. In this narrow portion, the nonwoven fabric 2, the top sheet 1, and the waterproof paper 4 are fixed to each other by thermal melting by the heat embossing HE. Regardless of whether the top sheet l is a plastic film or a nonwoven fabric, it will be fixed by thermal melting. In areas other than the narrow part, the nonwoven fabric 2 and the top sheet 1 are bonded with hot melt adhesive 3.
It is only fixed by. Of course, the three may be fixed to each other.

Reference numeral 11 denotes a slip-preventing hot melt adhesive that is adhered to the shorts after the release paper 12 is peeled off.

The front and back ends of the napkin are sealed with hot melt adhesive or the like.

Incidentally, it is known from Japanese Patent Application Laid-Open No. 125001/1983 to provide a cushioning material layer below a perforated hydrophobic fiber sheet. However, the cushioning material layer here is simply a single layer of hydrophobic fibers and is flush. This has disadvantages such as lack of cushioning properties and high cost as described later, so it is preferable to have a corrugated cross section and a laminated structure of multiple layers.

Therefore, in the embodiment, the cushioning material layer 5 is
It has a two-layer laminated structure of an upper layer 5A and a lower layer 5B. The reason for this two-layer structure is to increase the bulkiness of the cushioning material layer 5 and to provide voids between the layers to improve the cushioning properties and increase the absorption rate.
- It does not prevent it from being a layer or three or more layers.

The cushioning material in the present invention is hydrophobic fibers such as ES fibers (polypropylene fibers coated with polyethylene) and ET fibers (polypropylene fibers covered with polyethylene).
The main component is synthetic fibers (preferably 80% or more) such as polyester fibers covered with polyethylene.
The one that is used is The thickness of the fibers constituting the cushioning material is preferably 3 to 14 deniers. The synthetic fiber is not particularly limited as long as it is a hydrophobic fiber, and may be one that makes the cushioning material insensitive to moisture. If it is necessary to reduce the moisture insensitivity of the cushion layer, a method of spraying a surfactant or immersing it in a surfactant solution can be used, or a small amount of rayon fiber or the like may be included.

As a manufacturing method for the cushion material, a method can be used in which a part of fibers having heat-melting properties such as ES fibers and ET fibers is melted using a hot air flow and the fibers are bonded to each other. However, a fiber bonding method using an adhesive may also be used.

The basis weight of the cushion material is 8 g/rd to 30 g
/rd, and when laminated to form a corrugated shape, the sheets preferably have a basis weight of 20 g/rd to 90 g/rd. Different types of materials having different densities and deniers may be stacked.

In addition to the above reasons, the reasons why multi-layer cushioning material is preferable are that when supplying absorbent articles such as sanitary napkins in a rolled state in the process of manufacturing absorbent articles, it is preferable to roll up a thick single layer of cushioning material. This is because there is also the advantage that the number of times the winding needs to be replaced is reduced compared to using the winding method. The density of the cushion material itself is less than 0, tg/m, especially 0
．． 005 to 0.05 g/m is preferable. As for bulk,
0.5-10 cities, especially 1,0-7. ON is preferred.

As for the appearance finish form of the cushioning material layer, a flat sheet will have poor cushioning effect, so it is particularly preferable to make it wave-like (concert-like) as in the above example because it improves cushioning properties and absorption speed. .

When manufacturing such a corrugated cushioning material layer, it is preferable to employ the methods shown in FIGS. 4 to 7.

That is, as shown in (al to (C1) in FIG.
In order to obtain the shape of the blade, as shown in FIG.
Pressure is applied so that both rolls are brought into close contact with each other, and the original cushion material 5 is
Add a waveform to 0.

The blade roll 21 has a large number of annular blades 21a protruding from its surface at intervals in the longitudinal direction of the roll, and the blades 21a are heated to a temperature higher than the melting point of the cushioning material.
1a is being heated. This heating temperature is 100
~200℃, and when the cushioning material is ES fiber, ET fiber, or a mixed fiber thereof, the temperature is 160~1
90°C, especially 170 to 180°C is preferred. It is preferable that the receiving roll 22 is also a heated roll having a similar temperature or a slightly lower temperature. The blade roll 21 is, for example,
As shown in Figure 5, the outer diameter Φ is 100 mm and the length L is 10 mm.
ffi11. The blade pitch p can be 5 mm, and the blade tip thickness t can be 1.

In this way, after applying the waveform, downstream
The bellows mount 6 and the cushioning material layer can be quickly thermally bonded to each other by residual heat of the cushioning material or by a heating roll. Bonding may also be done by hot melt adhesive. The subsequent steps can be easily guessed from the structure of the napkin.

The cushioning material layer 5 may be provided at least in the longitudinal center of the napkin, and may extend over the entire length. The number of waves is preferably 3-10. In the embodiment, the bottom surface of the cushioning material layer 5 is flush with the receiving roll 22 because it has a flat surface. By using a corrugated roll, the lower surface of the cushioning material layer can also be formed into a corrugated shape. Therefore, both sides of the cushioning material layer may be corrugated.

According to the above example, when a pressure force is applied to the original fabric of the cushioning material by the blade roll, the original fabric is deformed into a wave shape by the applied force. At this time, since the temperature of the blade of the blade roll is higher than the melting point of the synthetic fibers forming the cushioning material, the fibers are not melted and deformed to restore their shape. Further, since the blade roll 21 is provided with a plurality of blades 21a, it is possible to form a plurality of waves at the same time, and if the temperature of the blades is kept considerably higher than the melting point, it is possible to form waves at high speed. Furthermore, when the troughs of the waves are pressurized or thermally melted by the blade 21a to create a density difference within the cushioning material, menstrual blood quickly moves from the crests to the troughs, as shown by the arrows in FIG. This can speed up the absorption of menstrual blood.

In the above example, the absorbent element according to the present invention was basically composed of the absorbent body 8 and the absorbent paper 7, but the absorbent element refers to the part that ultimately retains menstrual blood, and its composition is limited. It's not something you can do.

Although the bellows mount 6 is not essential, its presence
The shape retention of the cushioning material layer 5 is improved.

On the other hand, it is preferable that the perforated surface sheet 1 is made of a plastic film or a nonwoven fabric in terms of feel. When a plastic film is used, it may be shaped like a funnel as in the above-mentioned publication, or it may be simply a right-angled hole. No matter what material it is made of, the thickness of the top sheet should be less than laum, especially 0.
．． 1 order or less, the diameter Ds of the hole IO is 1 mm or less, and the open area ratio is 1
5 to 45%, especially 27 to 32%, wetting angle (angle formed by water droplet H) α is 90° or less, hole angle θ based on the outer surface is 90°
The above is preferable.

In order to form the hole IO, an appropriate method may be used such as puncturing with a needle or perforating with a high-pressure fluid such as high-pressure water. The reason why the holes 10 are teardrop-shaped in the topsheet when needles are used, as shown in FIG. 8, is that when the topsheet is passed between the heating needle roll and the elastic roll, the needles This is caused by a time lag when the sheet leaves the hole IO.

On the other hand, even if the bottom surface of the cushioning material layer is a bellows mount 6
Even if it is held by the wearer, the upper surface is free, so the waveform is likely to collapse due to pressure from the wearer, shear force, etc. Therefore, as in the above embodiment, it is preferable to fix the upper surface of the cushioning material layer 5 with the hot melt adhesive 9 to maintain the shape. The hot melt adhesive can be applied by bead coating or spray coating, but the former method results in a linear coating that is unpleasant to the touch, and the latter method requires high spray pressure. Therefore, when spraying onto the topsheet 1, it may block the holes IO or reach the conveyance roll through the holes IO, resulting in a problem in productivity. It is not impossible to spray the surface of the cushion material layer 5 if the production process is changed significantly, but the high spray pressure causes a large proportion of the material to penetrate into the cushion material, and if a large amount is applied, menstrual blood Both are undesirable as they impair the absorbability of the substance.

Therefore, it has been found that it is optimal to adopt a spiral coating method as shown in FIG. 1O. This method involves arranging one or more coating pads 11 in the width direction of the napkin,
By spraying the hot melt adhesive 9 from the center nozzle IIA of the application head 11, and by spraying high pressure air onto the hot melt adhesive 9 from the surrounding air holes 11B whose blowing directions do not face the center when viewed from the surrounding bottom surfaces, The hot melt adhesive 9 is made to flow out in a spiral manner. According to this method, the cushioning material layer 5 and the topsheet 1 are bonded to each other at random locations, and even if the applied area is small, the bonding is good, and effects such as improved tactility are brought about.

In the examples, the cushioning material layer 5 was formed into a corrugated shape in order to provide desired cushioning properties.

As a result, as shown in FIG.
The proportion of the contact area with the body decreases, impairing the inflow of menstrual blood. In order to practically satisfy both characteristics, the contact area between the surface of the cushioning material layer 5 and the top sheet l (to be more precise, the contact area since there are some areas where hot melt adhesive is not applied) Sc, The relationship with the non-contact area Sn is S
c/(Sc +S n ) ~0.3 (preferably 0.
5) ~0.7 is preferred. If the hot melt adhesive is an adhesive type, it may escape from the holes 10 to the surface, so a fixed type is preferable.

〔Effect of the invention〕

As described above, according to the present invention, the sanitary napkin has excellent tactility, is inexpensive, can use a perforated plastic film, and has excellent adhesive properties when using an anti-slip adhesive. can be provided.

[Brief explanation of the drawing]

Figure 1 is a partially cutaway view of an example of the structure of a sanitary napkin, Figure 2
3 are views taken along the II-n line and ■-■ line, respectively, FIG.
The figure is a relationship diagram between the blade roll and the receiving roll, and Fig. 6 (a
l ~ (C1 is a schematic diagram of an example of folding the original cushioning material,
Fig. 7 is an explanatory diagram of the state of corrugation, Fig. 8 is a plan view of the top sheet, Fig. 9 is a sectional view of the surface portion, Fig. 10 is a perspective view of an example of a hot melt adhesive coating device, and Fig. 11 is a A sectional view of the coating head, and FIG. 12 is a bottom view thereof. ■... Surface sheet 2... Nonwoven fabric 4... Waterproof paper 6... Bellows mount 8... Absorber 10... Holes 5... Cushion material layer 7... Absorbent paper 9...・Hot melt adhesive 11... Application head

Claims (2)

[Claims] (1) An absorbent element, a perforated surface sheet having a large number of holes arranged above the absorbent element, a lip groove-shaped nonwoven fabric that wraps around the absorbent element and spans the lower surface, side surfaces, and upper side portions of the absorbent element; a lip-groove-shaped liquid-impermeable sheet that is located between the absorbent element and spans the lower surface, side surfaces, and upper side portions of the absorbent element;
The lip part of the liquid-impermeable sheet, the side part of the top sheet, and the lip part of the nonwoven fabric are stacked in order, and at least the lip part of the liquid-impermeable sheet and the side part of the top sheet are fixed to each other. Characteristic sanitary napkins. (2) an absorbent element, a perforated top sheet having a large number of holes arranged above the absorbent element, a lip groove-shaped nonwoven fabric that wraps around the absorbent element and spans the bottom, side and top sides of the absorbent element; a hydrophobic cushioning material layer disposed between the sheet and the absorbent element; a lower surface of the nonwoven fabric and the absorbent element;
a liquid-impermeable sheet in the form of a lip groove extending over the side surfaces and the side portions of the top surface; A sanitary napkin characterized in that a lip part of a liquid-impermeable sheet and a side part of a top sheet are fixed to each other.