JPH0667398B2 - Absorbent article facing material - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial field of application] The present invention relates to a liquid-absorbent group which is coated on an absorbent substrate which absorbs liquid such as urine or blood, or which is placed on the substrate. The present invention relates to a facing material, and more particularly to a facing material containing a non-woven fabric as a part of a suitable structure for a disposable diaper or sanitary ware.

[Conventional technology and its problems]

Liquid absorbent articles, such as diapers and sanitary napkins, have a backing sheet for preventing liquid leakage on the back side of a water-absorbent substrate made of pulp, water-absorbent polymer or a mixture thereof, and for keeping the shape of the substrate on the surface. It has a three-layer structure including the facing material (also referred to as a topsheet). Conventionally, non-woven fabric, gauze, and film have been used as this facing material.

However, non-woven fabrics and gauze cause the liquid absorbed by the water-absorbent substrate to return to the user and cause discomfort to users of diapers and sanitary napkins, while those with sensitive skin such as infants may experience skin irritation. It is also one of the causes.

Therefore, the fibers constituting the non-woven fabric or gauze are made to be hydrophobic fibers, or water repellent treatment is performed, but this method allows urine and blood to reach the absorbent base material promptly. However, there is a problem in that the reversion decreases but the absorption performance, that is, the hydrophilicity, decreases.

When using the film as a facing material,
It is conceivable to provide a small hole in the film or a small hole provided with a valve for preventing backflow, but the film itself, which is the material, has poor breathability, which causes skin irritation. .

In addition, in order to hold a water-absorbent base material made of pulp or a water-absorbent polymer, there is a facing material having a structure in which the base material is coated with a tissue and a non-woven fabric or the like is laminated on it.
Since the tissue itself is hydrophilic, the water absorbency of the liquid is excellent, but it cannot prevent the reversion.

[Problems to be solved by the invention]

As described above, most of the conventional facing materials do not completely satisfy both of the water absorption and the reversion prevention.

Therefore, one of the objects of the present invention is to provide a facing material having an excellent anti-backflow property. Another object of the present invention is to provide a facing material having excellent water absorbency, that is, hydrophilicity. Another object of the present invention is to provide a facing material having an excellent texture and a good feeling of contact with the skin. Still another object of the present invention is to provide a facing material which can achieve the above-mentioned object with an extremely simple structure, not a complicated and special structure. Still another object of the present invention is to provide a facing material which can be manufactured easily and at low cost. Other objects of the present invention will be apparent from the description of the specification and the drawings.

[Means for solving problems]

That is, the present invention relates to a facing material for covering or placing an absorbent base material on the base material, wherein the facing material comprises a hydrophilic non-woven fabric (A) on one outer layer and a fiber of 3 denier or more. A hydrophobic non-woven fabric (B) constructed as above is used as the other outer layer, and has a laminated structure including at least Tatsuyu as an intermediate layer, and the non-woven fabric (A) is on the surface side and the non-woven fabric (B) is on the absorbent substrate side. It is a facing material for absorbent articles, which is characterized in that

[Action and effect]

The facing material of the present invention has a laminated structure including a hydrophilic non-woven fabric (A) on the surface side, a hydrophobic non-woven fabric (B) facing the absorbent substrate side, and at least a tissue as an intermediate layer.

Since the non-woven fabric (A) is the surface layer side of the facing material and comes into direct contact with the skin as described above, it is preferable that the non-woven fabric has a particularly good texture and a good feel. Therefore, the constituent fibers should be as thin as possible and the basis weight should be large to some extent. Therefore, it is preferable to give a sense of volume. Therefore, the weight per unit area which is usually composed of 1 to 4 denier fibers, especially 1 to 2 denier fibers is 15
-50 g / m ^{2 and} especially 20-30 g / m ² non-woven fabric is suitable.

Further, the nonwoven fabric (A) must be hydrophilic so that urine and blood can reach the absorbent substrate from the surface side as quickly as possible. Therefore, when the hydrophobic fiber made of the hydrophobic resin is used as the fiber forming the nonwoven fabric (A), hydrophilic treatment such as surface treatment with a surfactant is performed. Further, as long as it is composed of hydrophilic fibers made of a hydrophilic resin, it may be used as it is, or may be subjected to a hydrophilic treatment to further enhance hydrophilicity. Of course, in addition to the above, water repellent treatment may be performed in the opposite range to the extent that hydrophilicity is not impaired, and some hydrophobicity may be imparted.

A non-woven fabric which is not completely hydrophilic but also has some hydrophobicity is preferably used in the present invention. That is, since it is relatively hydrophilic, it quickly passes when urine or blood comes into contact with it, but when a small amount of urine or blood comes into contact with it due to reversion, urine or blood is slightly present due to its hydrophobicity. Are prevented from re-passing and oozing to the surface side. In particular, as in the present invention, the presence of the hydrophobic non-woven fabric (B) makes it possible to greatly reduce the amount of reversion, which is effective when only a very small amount of reversion reaches the back surface of the non-woven fabric (A). is there. From this point of view, the most suitable form of the nonwoven fabric (A) is a nonwoven fabric having hydrophobicity in which hydrophobic fibers are subjected to hydrophilic treatment.

As the non-woven fabric, those produced by various production methods can be used, but the one produced by the spun bond method is particularly preferable. That is, since the nonwoven fabric produced by the spunbond method has a structure in which continuous fibers are densely entangled with each other, the nonwoven fabric is bulky and has an excellent texture and is also very excellent in strength.

As the polymer compound which is a raw material of the fibers constituting the non-woven fabric, various known compounds can be used as long as they are not water-soluble. For example, polyethylene, polypropylene, etc., polyolefin, polyethylene terephthalate, polytetramethylene terephthalate, etc. polyester, nylon 6 Polyamide such as nylon 66, rayon, vinylon, etc. can also be used. Of course, even if the polymer compound is not exemplified here,
It will be apparent to those skilled in the art that it can be used as long as it is fiber-forming and the resulting fiber is not water soluble.

A preferred embodiment of the non-woven fabric (A) of the present invention is a non-woven fabric made of hydrophobic fibers obtained by the spunbond method as described above, which has been subjected to a hydrophilic treatment. Suitable polymer compounds include moldability, economy,
From the viewpoints of mechanical properties, chemical resistance and the like, polyolefin is particularly preferable, and polypropylene is preferable.

Hydrophilic treatment can be achieved by a well-known method of surface-treating with a surfactant as described above, but usually after producing a nonwoven fabric, the nonwoven fabric is sprayed with a surfactant, or a roller coater or the like is applied to the surface. A method of applying a surface-active agent or immersing in a surface-active agent for impregnation is used. The surfactant used at this time is not particularly limited, and various known surfactants are used, and the type and coating amount thereof are appropriately selected depending on the required performance of the final product.

The non-woven fabric (B) is located in the outer layer of the facing material on the side of the water-absorbent substrate and therefore does not come into direct contact with the skin.
The main purpose of the non-woven fabric (B) is that urine and blood that have reached and reached the water-absorbent substrate undergo some pressure before they are completely absorbed and retained by the water-absorbent substrate, and then return to re-face. This is to prevent the material from bleeding out.
Therefore, the nonwoven fabric (B) must be hydrophobic. However, if it is simply a hydrophobic non-woven fabric, the passage of urine or blood from the surface layer side passing through the non-woven fabric (A) to the water-absorbent adhesive side is obstructed, so that urine or blood is kept in the surface layer forever. It becomes a facing material that is inferior in hydrophilicity and remains in the state. In the present invention, in order to solve such a problem, the fibers constituting the nonwoven fabric (B) are solved by using fibers having a denier of 3 denier or more, particularly 6 denier or more, and more preferably relatively thick fibers. By using such a thick fiber, the fiber surface area is reduced for the same basis weight, and a non-woven fabric having a large inter-fiber void is formed,
Therefore, the hydrophobicity is apparently reduced. Therefore, for a relatively large amount of urine and blood passing from the surface side, although it does not hinder its passage, it is easy for the small amount of urine and blood returning to exhibit a hydrophobic property, It is considered to play a role as a backflow prevention layer.

The fibers constituting the non-woven fabric (B) are completely opposite to those in the non-woven fabric (A), and when hydrophilic fibers made of a hydrophilic resin are used, a water repellent treatment such as surface treatment with a water repellent agent is performed. I do. Further, as long as it is composed of a hydrophobic fiber made of a hydrophobic resin, it may be used as it is. Of course, water repellency may be given to further increase the hydrophobicity, and conversely, it may be possible to give hydrophilicity to some extent by performing hydrophilic treatment within a range not impairing the hydrophobicity.

The non-woven fabric (B) made of hydrophobic fiber is preferably used in the present invention. That is, it is adjusted by the fiber diameter so as not to obstruct the flow of urine and blood passing from the surface side, so the constituent fiber itself is provided by the hydrophobic fiber whose main purpose is to prevent reversion. It should be configured. As the non-woven fabric, those produced by various production methods can be used, but the spun-bonding method is preferred for the same reason as for the non-woven fabric (A). For the above reasons, the non-woven fabric (B) of the present invention is preferably a spun-bonded non-woven fabric using polyolefin, especially polypropylene.

The basis weight of the non-woven fabric (B) can take various ranges, but it is 10 to 30 from the purpose and the position of the laminated structure.
g / m ^2, especially 15-25 g / m ² are preferred.

The non-woven fabric (B) may be used as a single layer, or may be used by stacking a plurality of layers as necessary. As the number of non-woven fabrics (B) increases, the effect of preventing reversion improves.

At least a tissue (thin paper) is provided in the intermediate layer between the nonwoven fabric (A) and the nonwoven fabric (B) constituting the outer layer. The presence of Tetsuyu brings hydrophilicity and temporary retention of urine and blood, and exhibits an action of promptly absorbing urine and blood coming from the surface layer side of the nonwoven fabric (A). Further, as described above, when a plurality of non-woven fabrics (B) are used in order to improve the reversion prevention property, the non-woven fabrics tend to be slightly hydrophilic because the non-woven fabrics are hydrophobic. In such a structure, when at least the tissue is present as the intermediate layer, the above-described effect of imparting hydrophilicity is more clearly exhibited, and the decrease in hydrophilicity can be prevented.

Specific examples of the laminated structure of the facing material of the present invention having a tasyu as an intermediate layer include, for example, (i) non-woven fabric (A) / tashes / non-woven fabric (B) (ii) non-woven fabric (A) / tashes / non-woven fabric (B) / Non-woven fabric (B) (iii) Non-woven fabric (A) / Non-woven fabric (B) / Tattoo / Non-woven fabric (B) (iv) Non-woven fabric (A) / Tatish / Non-woven fabric (B) / Tatish / non-woven fabric (B). Among these, from the standpoint of both balance of excellent anti-backflow property and excellent hydrophilicity,
Using a plurality of non-woven fabrics (B) (ii), (iii), (i
v) is preferable, and (iii) is preferable from the viewpoint of excellent prevention of reversion.

Teshiyu is a paper of 400 g / m ^{2 and} especially 20 g / m ² or less,
In addition to normal paper, drop paper such as toilet paper may be used.

Next, application examples of the facing material of the present invention will be described with reference to the drawings.

1 and 2 show an example in which the facing material of the present invention is applied to a disposable diaper.

In the figure, 1 and 11 are facing materials of the present invention. 3 and 13
And 4 and 14 are the pipe and the water-absorbent polymer that constitute each absorbent substrate. On both sides of the absorptive base material, there are Tatsushiu 2,12 for shape retention of the base material and for hydrophilicity improvement, and polyethylene sheets 5,15 for liquid leakage prevention on the side facing the outside. It is provided. In the case of FIG. 2, a nonwoven fabric 16 is provided to maintain the strength of the water-absorbent polymer layer.

FIG. 3 is an example applied to a sanitary napkin.

In the figure, 21 is a facing material of the present invention, 24 is an absorbent substrate,
25 is a polyethylene sheet for preventing liquid leakage. 27 is a cushion material and 28 is an adhesive tape. In this embodiment, the facing material covers the absorbent base material.

4 and 5 are views showing the structure of the facing material of the present invention.

In the figure, 41 and 51 are non-woven fabrics (A), 42 and 52 are non-woven fabrics (B), and 43 and 53 are tastes. In this figure,
Of course, 41 or 51 is in contact with the human body.

In addition, although not shown, as an application example of the facing material of the present invention, a surgical vampire band or a postpartum pad can be used.

〔Example〕

The contents of the present invention will be described in detail below with reference to suitable examples, but the present invention is not limited to these examples unless otherwise specified.

The amount of reversion and the hydrophilicity in the following examples were evaluated by the following methods.

(Evaluation of the amount of reversion) Put the test piece in the frame of 95 mm in length and width and 10 mm in depth so that the facing material is on top, and 70 mm from the surface of the facing material.
0.1% aqueous sodium chloride solution is dropped onto the test piece at a rate of 10 cc / sec for 8 seconds from the height. After leaving for 5 minutes after dropping, take out the test piece, put 20 pieces of 100 mm square filter paper (Toyo Filter Paper No.526) on the test piece, and put it on 160 mm x 220 mm
Place another 3.5 kg weight on the acrylic plate and leave for 3 minutes. Next, the weight is removed, and after standing for another 2 minutes, the filter paper is weighed. This operation is repeated 3 times and the amount of reversion (g) is calculated from the weight difference from the filter paper before the test.

(Evaluation of hydrophilicity) Place the test piece on the sheet of stacked toys paper with the facing material facing up, and then from the surface of the facing material.
It is evaluated by how many times out of 10 times it takes 2 seconds or more to drop one drop (about 0.1g) of a 0.1% sodium chloride aqueous solution from a height of 15mm and start passing through the surface of the facing material. To do.

Reference example 1 2 denier polypropylene fiber basis weight 20 g / m ²
The spunbonded non-woven fabric of No. ² was coated with a 2.5% aqueous solution of a polyoxyethylene alkylphenol type surfactant at a ratio of 4 cc / m ² and subjected to hydrophilic treatment to obtain a non-woven fabric (A) of the facing material of the present invention. Further, a spunbonded nonwoven fabric having a basis weight of 20 g / m ² made of polypropylene fiber of 4 denier was used as a nonwoven fabric (B) of a facing material.

The non-woven fabric (B) and further the non-woven fabric (A) were laminated on the absorbent substrate composed of the water-absorbent polymer and the pulp so that the non-woven fabric was on the surface side, and the amount of reversion was measured by the method described above.

The nonwoven fabric (B) and the nonwoven fabric (A) were laminated on 10 sheets of toilet paper, and the hydrophilicity was measured by the method described above.

The results are shown in Table 1.

Reference Comparative Example 1 The same procedure as in Reference Example 1 was carried out except that a spunbonded non-woven fabric made of 2 denier polypropylene fiber and having a basis weight of 20 g / m ² was used as the non-woven fabric (B).

The results are shown in Table 1.

Reference Comparative Example 2 The procedure of Reference Example 1 was repeated except that a non-woven fabric (B) having a basis weight of 25 g / m ² made of nylon 6 fiber of 2 denier was used.

The results are shown in Table 1.

Reference Comparative Example 3 The procedure of Reference Example 1 was repeated except that the non-woven fabric (B) was not used. The results are shown in Table 1.

Reference Example 2 The procedure of Reference Example 1 was repeated except that a spunbonded nonwoven fabric having a basis weight of 20 g / m ² made of 8 denier polypropylene fiber was used as the nonwoven fabric (B).

The results are shown in Table 1.

Reference Example 3 The procedure of Reference Example 1 was repeated, except that a spunbond nonwoven fabric having a basis weight of 12 g / m ² made of polypropylene fiber of 4 denier was used as the nonwoven fabric (B).

The results are shown in Table 1.

As can be seen from the results in Table 1, the facing material having the laminated structure of the non-woven fabric (A) and the non-woven fabric (B) reduces the amount of reversion and does not impair the hydrophilicity. On the other hand, it can be seen that the nonwoven fabric (B) composed of fine denier fibers is poor in either the amount of reversion or the hydrophilicity and cannot balance the two.

Comparative Example 1 The amount of reversion was measured in the same manner as in Reference Example 1 except that two non-woven fabrics (B) in Reference Example 2 were laminated to form a non-woven fabric (A) / non-woven fabric (B) / non-woven fabric (B).

The results are shown in Table 2.

Example 1 Between the nonwoven fabric (A) and the nonwoven fabric (B) in Comparative Example 1,
The measurement was performed in the same manner as in Comparative Example 1 except that a toilet paper was provided as a taste.

The results are shown in Table 2.

Example 2 The same measurement as in Comparative Example 1 was carried out except that toilet paper was provided between the two nonwoven fabrics (B) in Comparative Example 1.

The results are shown in Table 2.

As can be seen from the results shown in Table 2, the laminate of two non-woven fabrics (B) has a very remarkable effect of preventing reversion, but the hydrophilicity is completely impaired, and it is used as a facing material for absorbent articles. It turns out that is not very suitable. On the other hand, as in the case of the present invention, the one in which Tatsuyu is present as the intermediate layer is excellent in both the reversion preventing effect and the hydrophilicity.

[Brief description of drawings]

1 to 3 are views showing an embodiment in which the facing material of the present invention is applied to an absorbent article, and FIGS. 4 and 5 are views showing an embodiment of the facing material of the present invention.

Claims (10)

[Claims] 1. A facing material for coating or placing an absorbent base material on the base material, wherein the facing material comprises a hydrophilic non-woven fabric (A) in one outer layer and a fiber of 3 denier or more. A hydrophobic non-woven fabric (B) constructed as above is used as the other outer layer, and has a laminated structure including at least Tateyu as an intermediate layer, and the non-woven fabric (A) is on the surface layer side and the non-woven fabric (B) is on the absorbent substrate side. A facing material for an absorbent article, wherein the facing material is arranged as follows. 2. The facing material according to claim 1, wherein the non-woven fabric (A) is a non-woven fabric composed of fibers having a denier of 1 to 4 and having a basis weight of 15 to 50 g / m ² . 3. The facing material according to claim 1 or ² , wherein the basis weight of the nonwoven fabric (B) is 10 to 30 g / m ² . 4. The facing material according to any one of claims 1 to 3, wherein a plurality of nonwoven fabrics (B) are used. 5. The facing material according to any one of claims 1 to 4, wherein the nonwoven fabric (A) is composed of hydrophilic fibers. 6. The non-woven fabric (A) is composed of hydrophobic fibers and is hydrophilically treated.
Item 5. The facing material according to any one of items 4 to 4. 7. The facing material according to any one of claims 1 to 6, wherein the nonwoven fabric (B) is composed of hydrophobic fibers. 8. The non-woven fabric (B) is composed of hydrophilic fibers and is subjected to a water repellent treatment.
Item 7. The facing material according to any one of Items 6 to 6. 9. The facing material according to any one of claims 1 to 8, wherein the laminated structure is non-woven fabric (A) / taste / non-woven fabric (B) / non-woven fabric (B). 10. A non-woven fabric (A) / non-woven fabric (B) having a laminated structure.
/ Tissue / non-woven fabric (B)
Item 9. The facing material according to any one of Items 8 to 8.