JP2002011046A - Back sheet for sanitary goods and sanitary goods - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a back sheet for sanitary goods and sanitary goods with superb water solubility and leak-proof property which, thrown into the toilet, quickly dissolves in water without becoming a jellylike lump in water. SOLUTION: A bodily fluid absorbing member is pinched and surrounded by a body fluid-permeating surface sheet and bodily fluid-non-permeating back sheet, and further, an adhesive layer is formed on a face opposite to the side of the bodily fluid absorbing member of the back sheet. The back sheet for sanitary goods, moreover, has a water-soluble base material, on one face of which a filler layer made of bodily fluid non-permeating water soluble resin is integrally laminated.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a back sheet used for sanitary articles and a sanitary article using the back sheet.

[Prior art]

[0002] Conventionally, sanitary articles such as sanitary napkins and orimono absorbent sheets generally have a body fluid absorbing member sandwiched and surrounded by a body fluid permeable top sheet and a body fluid impermeable back sheet. On the outer surface of the back sheet,
An adhesive layer is formed to fix the sanitary article to underwear. FIG. 2 is a partially cutaway perspective view schematically showing a conventional sanitary article, and FIG. 3 is a sectional view taken along line AA in FIG. Numeral 2 is a sanitary article, and a body fluid-permeable topsheet 2
1, body fluid absorbing member 22, body fluid impermeable back sheet 2
The release sheet 3 and the release paper 24 are laminated in this order, and the back sheet 23 and the release paper 24 are temporarily fixed by the adhesive layer 25.

[0003] The above sanitary articles are discarded after use. Conventionally, however, they often include a non-water-disintegrable member as a whole. There is a problem that pipes are often clogged when flushed into a toilet. As a method for solving the above-mentioned problem, for example, Japanese Patent Laid-Open Publication No. Hei 5-161672 discloses a sanitary article which has water disintegration as a whole, is water-disintegrated even when flushed into a toilet, and is unlikely to cause pipe clogging.

[0004] However, the sanitary articles described in the above publication use water-repellent paper treated with water-repellent water-insoluble material such as fluorine, silicone, dimethyl silicone, etc. as the back sheet, and sufficient water-dissolvability is obtained. Within the range, there is a problem that the leak-proof property tends to be insufficient, and it is difficult to achieve both water-dissolving property and leak-proof property.

In the sanitary articles described in the above-mentioned publications, the water-repellent resin sheet used as a surface sheet of the sanitary articles is liable to form jelly-like lumps in water when the toilet articles are flushed, and the load on the septic tank is high. There was also the problem of becoming.

[0006]

SUMMARY OF THE INVENTION It is an object of the present invention to have excellent water dissolving properties and leak-proofing properties, and to quickly disintegrate even in a toilet without forming jelly-like lumps in water. It is an object of the present invention to provide a back sheet for sanitary goods and a sanitary article. Another object of the present invention is to provide a back sheet for sanitary articles and a sanitary article which is excellent in feeling of use, in which, in addition to the above-mentioned water dissolving property and leak-proof property, adhesive residue due to sweat, moisture and the like during use of the sanitary article hardly occurs. Is to do.

[0007]

According to the present invention, there is provided a back sheet for sanitary goods, wherein a body fluid absorbing member is sandwiched and surrounded by a body fluid permeable top sheet and a body fluid impermeable back sheet, and It is used for sanitary ware in which the pressure-sensitive adhesive layer is formed on the surface of the back sheet opposite to the body fluid-absorbing member side, and one surface of the water-decomposable base material is made of a body fluid-impermeable water-soluble resin. The sealing layer is characterized by being laminated and integrated.

FIG. 1 is a schematic cross-sectional view of a back sheet for sanitary ware according to the present invention. The back sheet for sanitary ware 1 comprises a water-disintegrable base material 11 and a sealing layer 12 laminated and integrated.

The water-decomposable substrate 11 used in the present invention is not particularly limited as long as it is a sheet having water-decomposability. For example, the fibers become entangled in water and fibers are separated from each other. And a fibrous body composed of the water-disintegrable fiber in a state. Among them, a nonwoven fabric made of water-decomposable fibers is preferably used. Examples of the water-decomposable fiber include pulp, rayon, cupra, cotton, hemp, wool, silk, and the like. Among them, pulp is preferable. The water-decomposable fibers may be bound together by a water-soluble binder. Examples of the water-soluble binder include polyvinyl alcohol, cellulose derivatives such as methyl cellulose and hydroxyethyl cellulose, starch, sodium alginate, sodium polyacrylate, polyacrylate, and the like.

In addition to the above-mentioned nonwoven fabric, a sheet or the like in which short fibers made of a synthetic resin are bound to each other by a water-soluble binder can be used as long as it has water dissolvability.
Examples of the synthetic resin include a polyethylene-based resin, a polypropylene-based resin, a polyester-based resin, and a polyamide-based resin. Examples of the water-soluble binder include those similar to those used for the nonwoven fabric.

When the basis weight of the water-disintegrable base material is reduced, the strength is reduced, processing becomes difficult, and when the basis weight is increased, the water-disintegrability of the obtained back sheet for sanitary goods and sanitary goods is reduced. m ² is preferred.

The water-soluble resin constituting the filling layer 12 used in the present invention has a body fluid impermeability when formed into a layer, and is, for example, polyvinyl alcohol, polyacrylamide, polyacrylic acid, polyethylene oxide. ,
Examples thereof include vinyl ether-based polymers and modified products thereof, among which polyvinyl alcohol and modified products thereof are preferable.

Examples of the modified polyvinyl alcohol include those obtained by adding ethylene oxide to polyvinyl alcohol, and ethylene-vinyl alcohol copolymers having an ethylene content of less than 50 mol%.
The ethylene content of the ethylene-vinyl alcohol copolymer is lower, the water resistance of the resulting sanitary goods backsheet and sanitary goods is reduced, the leakproofness is reduced, and the obtained sanitary goods backsheet is increased when the amount is increased. Since the water disintegration property of the sanitary article decreases, 3 to 40 mol% is preferable.

When the basis weight of the filling layer is small, film formation becomes difficult, and when it is large, the obtained backsheet for sanitary goods becomes too stiff and the feeling of use of the obtained sanitary goods is reduced. When polyvinyl alcohol or a modified product thereof is used as the water-soluble resin, 5 to 10
0 g / m ² is preferable, and more preferably 10 to 30 g / m ²
m ² .

The method for laminating and integrating the water-decomposable base material and the sealing layer is not particularly limited. For example, a method in which a water-soluble resin constituting the sealing layer is extrusion-laminated on one surface of the water-decomposable base material, A method in which a water-soluble resin constituting the stop layer is formed into a film and the film is partially adhered to one surface of the water-disintegrable base material with an adhesive, etc., but the interlayer adhesion strength is excellent and the process is simple. Therefore, a method by extrusion lamination is preferred. In addition, since the water-disintegratable base material and the filling layer are integrated over the entire surface by laminating and integrating by extrusion lamination, the water-disintegratable base material that easily disperses in water when the obtained sanitary article is poured into a toilet. Is preferable since the water dispersion of the sealing layer is easily promoted and the back sheet for sanitary goods is rapidly hydrolyzed.

The back sheet for sanitary ware of the present invention is used as the back sheet 23 of the sanitary ware 2 shown in FIG. That is, the backsheet for sanitary goods, the surface sheet permeable to body fluid, the body fluid absorbing member is sandwiched and surrounded, and, on the surface opposite to the body fluid absorbing member side of the backsheet for sanitary goods. A pressure-sensitive adhesive layer is formed, which is used as a sanitary product.

In the backsheet for hygiene articles, it is preferable that the water-decomposable base material is on the body fluid absorbing member side and the filling layer is on the pressure-sensitive adhesive layer side. When the water-disintegratable substrate is on the side of the adhesive layer, the water-disintegratable substrate absorbs sweat, moisture, etc. while using the sanitary ware, so the strength of the water-disintegratable substrate decreases, and When the article is peeled off from the underwear, the strength of the water-disintegrable base material becomes weaker than the adhesive strength between the adhesive layer and the underwear, so that the water-disintegrable base material is destroyed, and the adhesive layer is slightly damaged. The so-called glue residue easily remains in the underwear together with the water-disintegrable base material. By setting the filling layer on the side of the pressure-sensitive adhesive layer, such adhesive residue can be prevented. Further, in order to prevent displacement of the body fluid absorbing member, irregularities may be formed on the surface of the water-disintegrable substrate of the back sheet for sanitary goods by mat processing or the like.

The surface sheet is not particularly limited as long as it is a sheet having water dissolving property and body fluid permeability. For example, a water dissolving material in which fibers become entangled in water and fibers are separated from each other is obtained. Fibrous bodies made of conductive fibers. Among them, a nonwoven fabric made of water-decomposable fibers is preferably used. Examples of the water-decomposable fiber include pulp, rayon, cupra, cotton, hemp, wool, silk, and the like. Among them, pulp is preferable. The water-decomposable fibers may be bound together by a water-soluble binder. Examples of the water-soluble binder include polyvinyl alcohol, cellulose derivatives such as methylcellulose and hydroxyethylcellulose, starch, sodium alginate,
Examples thereof include sodium polyacrylate and polyacrylate.

When the basis weight of the topsheet is reduced, the strength is reduced, and the surface sheet is apt to be broken when the obtained sanitary article is used. / M ² is preferred.

The body fluid absorbing member is not particularly limited as long as it has water dissolving property and body fluid absorbing property. For example, a water dissolving property in which fibers become entangled in water and fibers are separated from each other. A fibrous body made of fiber is exemplified. Among them, a nonwoven fabric made of water-decomposable fibers is preferably used. As the water-disintegrable fiber, for example, pulp,
Rayon, cupra, cotton, hemp, wool, silk, etc.,
Among them, pulp is preferred. The water-decomposable fibers may be bound together by a water-soluble binder. Examples of the water-soluble binder include polyvinyl alcohol, cellulose derivatives such as methyl cellulose and hydroxyethyl cellulose, starch, sodium alginate, sodium polyacrylate, polyacrylate, and the like.

When the basis weight of the above-mentioned body fluid-absorbing member decreases, the body fluid absorbability of the obtained sanitary article decreases, and when the basis weight increases, the stiffness of the obtained sanitary article becomes too strong and the feeling of wearing deteriorates. / M ² is preferred.

Although the shape of the sanitary article is not particularly limited, it is generally formed so as to gradually become narrower toward the center as shown in the conventional sanitary article in FIG. A top sheet having a substantially vertically elongated rectangular shape and a back sheet having substantially the same shape as the top sheet are arranged so as to sandwich the body fluid absorbing member made smaller than the top sheet and the back sheet from the front and back, and these top sheets and The back peripheral sheet may be one in which opposing peripheral edges are integrated by heat fusion or an adhesive, and further, an adhesive layer is formed outside the back sheet.

[0023]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The embodiments of the present invention will be described in more detail with reference to the following examples, but the present invention is not limited to these examples.

Example 1 One surface of a non-woven fabric made of pulp (basis weight 15 g / m ² ) was coated with an ethylene-vinyl alcohol copolymer having an ethylene content of 20 mol% and a basis weight of 1
After extrusion lamination to 5 g / m ² , length 15
The sheet was cut into a rectangular shape of 0 mm x 54 mm to obtain a back sheet. Next, a non-woven fabric made of pulp (basis weight 30 g / m ² , rectangular shape of 150 mm × 54 mm width) as a surface sheet, and a non-woven fabric made of pulp (basis weight 45 g / m ² , 100 mm × 54 mm width) as a body fluid absorbing member Rectangular shape) was prepared. After sandwiching the body fluid-absorbing member between the nonwoven fabric side and the topsheet of the obtained backsheet, the opposite peripheral portions of the backsheet and the topsheet are adhered with a polyvinyl alcohol-based adhesive to surround the body fluid-absorbing member, and further, An acrylic pressure-sensitive adhesive was applied to the center of 2000 mm ² so that the coating amount was 10 g / m ² on the ethylene-vinyl alcohol copolymer layer side of the back sheet to obtain a sanitary article.

Example 2 The same back sheet, top sheet and body fluid absorbing member as in Example 1 were used, and the body sheet absorbing member was connected to the ethylene-vinyl alcohol copolymer layer side of the back sheet and the top sheet. After sandwiching, the opposite peripheral portions of the back sheet and the top sheet are adhered with a polyvinyl alcohol-based adhesive to surround the body fluid-absorbing member, and an acrylic adhesive is further applied to the nonwoven fabric side of the back sheet in the same manner as in Example 1. It was applied to obtain a sanitary article.

(Example 3) Polyvinyl alcohol (polymerization degree: 600, fighting rate: 88%, melting point: 190 ° C.) was coated on one surface of a nonwoven fabric made of pulp (basis weight: 15 g / m ² ), and the basis weight was 15 g / m ^2. After extrusion lamination to become
The sheet was cut into a rectangular shape having a length of 150 mm and a width of 54 mm to obtain a back sheet. Using the same topsheet and bodily fluid absorbent member as in Example 1, after sandwiching the bodily fluid absorbent member between the nonwoven fabric side of the backsheet and the topsheet, the opposite peripheral portions of the backsheet and topsheet are bonded by polyvinyl alcohol. The body fluid-absorbing member was surrounded by an adhesive, and an acrylic pressure-sensitive adhesive was applied to the backsheet in the same manner as in Example 1 on the polyvinyl alcohol layer side to obtain a sanitary article.

Example 4 Using a back sheet similar to that of Example 3, a top sheet and a body fluid absorbing member similar to that of Example 1, the body sheet was absorbed by the polyvinyl alcohol layer side of the back sheet and the top sheet. After sandwiching the conductive member, the opposing peripheral portions of the back sheet and the top sheet are adhered with a polyvinyl alcohol-based adhesive to surround the bodily fluid absorbing member. An adhesive was applied to obtain a sanitary article.

Comparative Example 1 The same ethylene-vinyl alcohol copolymer (ethylene content: 20 mol%) as used in the back sheet of Example 1 was weighed at 15 g /
After extruding into a single layer so as to obtain m ² , it was cut into a rectangular shape of 150 mm long × 54 mm wide to obtain a back sheet. Next, using the same topsheet and body fluid absorbing member as in Example 1, after sandwiching the body fluid absorbing member between one surface of the obtained backsheet and the topsheet, the opposing peripheral portions of the backsheet and topsheet are used. Was adhered with a polyvinyl alcohol-based adhesive to surround the body fluid-absorbing member, and an acrylic pressure-sensitive adhesive was applied to the other surface of the back sheet in the same manner as in Example 1 to obtain a sanitary article.

(Comparative Example 2) A nonwoven fabric made of the same pulp as used in the back sheet of Example 1 (basis weight 15 g / m2)
² ) was cut into a rectangular shape having a length of 150 mm and a width of 54 mm to obtain a back sheet. Next, the same topsheet and bodily fluid absorbent member as in Example 1 were prepared, and after sandwiching the bodily fluid absorbent member between one surface of the obtained back sheet and the topsheet,
The opposite peripheral portions of the back sheet and the top sheet are adhered with a polyvinyl alcohol-based adhesive to surround the body fluid absorbing member, and an acrylic pressure-sensitive adhesive is applied to the other side of the back sheet in the same manner as in Example 1. , Got sanitary goods.

Comparative Example 3 A nonwoven fabric made of the same pulp as used in the back sheet of Example 1 (basis weight 15 g / m2)
² ) On one surface, a coating agent obtained by mixing and stirring 100 parts by weight of platinum-added silicone and 5 parts by weight of a platinum catalyst was applied so that the basis weight of the solid content was 0.5 g / m ² . rear,
The sheet was cured by heating and cut into a rectangular shape having a length of 150 mm and a width of 54 mm to obtain a back sheet. Next, using the same topsheet and bodily fluid absorbent member as in Example 1, after sandwiching the bodily fluid absorbent member between the coating agent-coated surface of the obtained backsheet and the topsheet, the backsheet and topsheet were obtained. The peripheral edges of the sheet were adhered with a polyvinyl alcohol-based adhesive to surround the body fluid-absorbing member, and an acrylic pressure-sensitive adhesive was applied to the nonwoven fabric side of the back sheet in the same manner as in Example 1 to obtain a sanitary article. .

With respect to the above Examples and Comparative Examples, the water disintegration property and leakproof property of the obtained back sheet and the leakproof property and presence or absence of adhesive residue of the obtained sanitary article were evaluated, and the results are shown in Table 1. Was.

(Water degradability of back sheet) The water decomposability of the obtained back sheet was measured in accordance with JIS P4501. The back sheet obtained in Comparative Example 1 became a jelly-like lump in water and could not be measured.

(Leak-proofing property of back sheet) The obtained back sheet is horizontally arranged so that the surface on which the body fluid-absorbing member is arranged faces upward, and the backsheet is placed on the surface on which the body fluid-absorbing member is arranged. .
1 g of water drops were added dropwise. Ten minutes after the dropping, the surface opposite to the dropping surface was visually observed and evaluated as follows. ：: No leak was confirmed ×: Leak was confirmed

(Leak-proofing property of sanitary article) The obtained sanitary article was placed horizontally with the top sheet facing upward, and 0.7 g of water droplets were dropped on the top sheet. Ten minutes after the dropping, the back sheet side of the sanitary article was visually observed and evaluated as follows. ：: No leak was confirmed ×: Leak was confirmed

(Presence or absence of adhesive residue on hygiene article) The obtained hygiene article was placed on a silk cloth so that the adhesive-coated surface of the hygiene article was on the cloth side. Next, from the top of sanitary goods, 10
A load of 0 g / cm ² was applied over the entire area, at a temperature of 40 ° C.
After leaving for 2 hours under the condition of a relative humidity of 90%, the load was removed and the sanitary article was peeled off from the cloth. After peeling off, the cloth surface was visually observed to confirm the presence of adhesive residue.

[0036]

[Table 1]

[0037]

The back sheet for sanitary goods according to the first aspect of the present invention has excellent water decomposability, so that it does not cause clogging of pipes even when flushed into a toilet, so that the sanitary goods can be used. The sanitary goods using the back sheet for use can be flushed into a toilet as long as the other members have water disintegration properties, and are excellent in handleability. In addition, since the dispersing power of the water-disintegrable base material that is easily dispersed in water promotes water diffusion of the filling layer, the sanitary product backsheet is rapidly hydrolyzed in water, and has a jelly-like shape. There is no lump, and the load on the septic tank is small even when flushed into the toilet. Furthermore, since the back sheet for sanitary goods is also excellent in leakproofness, the sanitary goods using the back sheet for sanitary goods do not leak during use and have a good feeling of use.
The backsheet for sanitary goods of the invention according to claim 2, since the surface on which the pressure-sensitive adhesive layer is formed is a sealing layer, when the resulting sanitary goods are peeled off from underwear or the like after use, sweat during use, Glue residue due to moisture and the like is unlikely to occur. Since the back sheet for sanitary goods according to the third aspect of the present invention forms the sealing layer with a specific water-soluble resin, the back sheet for sanitary goods excellent in water dissolving property and leak-proof property as described above is easily obtained. Is obtained. The backsheet for sanitary goods of the invention according to claim 4 is obtained by a simple process and has excellent interlayer adhesion strength between the water-decomposable base material and the filling layer. Further, since the water-disintegrable base material and the sealing layer are integrated over the entire surface, the dispersing power of the water-disintegrable base material that is easily dispersed in water facilitates the water diffusion of the sealing layer, and the sanitary article The back sheet for use is rapidly hydrolyzed in water, does not form a jelly-like lump, and has little load on the septic tank even when flushed into a toilet. The sanitary article of the invention according to claim 5 uses the above-mentioned back sheet for sanitary goods, and since both the top sheet and the body fluid-absorbing member have water dissolving properties, they are excellent in water dissolving properties as a whole, It can be flushed to the toilet and is easy to handle. In addition, the back sheet that is most difficult to impart water disintegration is generally a jelly-like lump in water because the dispersing power of the water-disintegrable base material that is easily dispersed in water promotes water diffusion of the filling layer and is rapidly hydrolyzed. And the load on the septic tank is small even when flushed into the toilet. Furthermore, since the back sheet having excellent leakproofness is used, there is no occurrence of leakage during use, and a good feeling of use is provided. In the sanitary article according to the sixth aspect of the present invention, since the pressure-sensitive adhesive layer is formed on the filling layer, when peeled off from underwear or the like after use, adhesive residue due to sweat, moisture, or the like during use hardly occurs.

[Brief description of the drawings]

FIG. 1 is a schematic cross-sectional view of a back sheet for sanitary goods of the present invention.

FIG. 2 is a partially cutaway perspective view schematically showing a conventional sanitary article.

FIG. 3 is a sectional view taken along line AA of FIG. 2;

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Back sheet for sanitary articles 11 Water-disintegrable base material 12 Filler layer 2 Sanitary articles 21 Top sheet 22 Body fluid absorbing member 23 Back sheet 24 Release paper 25 Adhesive layer

 ────────────────────────────────────────────────── ─── Continuing on the front page (72) Inventor Hiroaki Nakagawa 2-2 Kamikaba Kamichocho Minami-ku, Kyoto City, Kyoto Prefecture Sekisui Chemical Co., Ltd. F-term (reference) 4C003 CA04 HA04

Claims (6)

[Claims] 1. A humor-absorbing member is sandwiched and surrounded by a humor-permeable top sheet and a humor-impermeable backsheet, and on a surface of the backsheet opposite to the humor-absorbing member side. A backsheet used for a sanitary article having an adhesive layer formed thereon, wherein a filling layer made of a body fluid impermeable water-soluble resin is laminated and integrated on one surface of the water-disintegrable base material. Back sheet for hygiene products. 2. The sanitary article back sheet according to claim 1, wherein the filling layer is provided on the side of the pressure-sensitive adhesive layer of the sanitary article. 3. The backsheet for sanitary goods according to claim 1, wherein the water-soluble resin is polyvinyl alcohol or a modified product thereof. 4. The water-disintegrable base material and the filling layer are laminated and integrated by extrusion laminating a water-soluble resin constituting the filling layer on one surface of the water-disintegrable base material. The back sheet for sanitary goods according to any one of claims 1 to 3. 5. A water-decomposable body fluid-absorbing member is sandwiched between the sanitary article back sheet according to any one of claims 1 to 4 and a water-decomposable body fluid-permeable topsheet. And a pressure-sensitive adhesive layer formed on the surface of the back sheet for sanitary goods opposite to the body fluid-absorbing member side. 6. The sanitary article according to claim 5, wherein the sealing layer of the back sheet for sanitary articles is on the side of the pressure-sensitive adhesive layer.