JP4540564B2 - Absorbent articles - Google Patents

Description

  The present invention relates to an absorbent article, and more particularly to an absorbent article used by being sandwiched between female labia.

DESCRIPTION OF RELATED ART Conventionally, small absorbent articles, such as an interlabial pad used by being pinched | interposed into the space between female labia, are known. This type of absorbent article is worn with its skin contact surface in direct contact with the labial area, and has improved leakage resistance. Conventionally, an absorbent article that can be washed in a flush toilet has been known. This type of absorbent article has both leak-proof property and washability during use, and can be poured into a flush toilet, so that its disposal is easy. A small absorbent article such as an interlabial pad is thought to be relatively easy to realize the possibility of washing with water because its constituent members are small and the number of constituent members is small.
In addition, there is a leak-proof body fluid without being decomposed in a wet state while being worn, and after the absorbent article is discarded in a flush toilet after use, the back side sheet does not remain in its original form. There has been proposed an interlabial pad absorbent article that has the ability to be washed with water that does not impair the function of the septic tank by being dispersed in a single sheet piece.

  For example, in Patent Document 1, an absorber is provided between a liquid-permeable front-side sheet and a liquid-impermeable back-side sheet, and the back-side sheet is composed of two sheet pieces and is adjacent. The sheet pieces have a longitudinal overlap portion formed by overlapping each other, and the longitudinal overlap portion is disposed at a position where the end of the sheet piece located on the body surface side is away from the longitudinal center line. Absorbent articles that are superimposed in this manner are disclosed.

JP 2004-261230 A

  In the absorbent article described in Patent Document 1, the two liquid-impermeable sheet pieces forming the back side sheet side are joined to each other by an adhesive at the overlapping portion. However, even if the adhesive is water-soluble, it is difficult for water to penetrate into the adhesive, so that it is difficult to disassemble into individual sheet pieces. Moreover, since the back side sheet has the above-described configuration, it is considered that this type of absorbent article is not easy to manufacture.

  Accordingly, an object of the present invention is to provide an absorbent article which is used by being sandwiched between labia and can be washed with water after use, and is easy to manufacture.

  The present invention is an absorbent article that includes an absorbent layer and a leak-proof layer and is used by being sandwiched between labia, and has a thickness of 5.5 mm or less when deployed in a planar shape. The leak-proof layer achieves the above object by providing an absorbent article that is separated by the water flow of a flush toilet.

  According to the absorbent article of the present invention, it is used by being sandwiched between labia and can be washed with water after use, and its manufacture is easy.

  Hereinafter, a preferred first embodiment of the disposable diaper of the present invention will be described with reference to FIGS.

As shown in FIGS. 1 and 2, the absorbent article 1 of the present embodiment includes a liquid-retaining absorbent layer 10 and a liquid-impermeable leak-proof layer 11, which is substantially vertically long, and is a female labia Used across the space between. The absorbent layer 10 in the absorbent article 1 is formed of a liquid-permeable top sheet 2 and a liquid-retaining absorbent body 4, and the leak-proof layer 11 is composed of a liquid-impermeable back sheet 3.
The absorbent article 1 of the present embodiment is used by being folded in two along the longitudinal direction and sandwiched between the labia's labia and has a thickness of 5.5 mm or less when deployed in a flat shape. The thickness is preferably 2.0 mm or less. The article 1 is made of a thin and soft material, and deforms and contacts flexibly according to the shape of the surface between the labia.
The absorbent layer 10 and the leak-proof layer 11 in the absorbent article 1 of the present embodiment are separated by the water flow of the flush toilet when the article 1 is discarded in the flush toilet after use. The article 1 may be often washed away in a flush toilet, but may be discarded in a waste container or the like, and is not necessarily discarded in a flush toilet (the same applies hereinafter).
In the absorbent article 1 of the present embodiment, the top sheet 2 is a water-decomposable nonwoven fabric, the absorbent body 4 is water-degradable paper, and the absorbent layer 10 has water-decomposable properties. Moreover, the back sheet 3 which is a leak-proof layer has biodegradability.

  If the absorbent article 1 of this embodiment is explained in full detail, the surface sheet 2 and the back surface sheet 3 will each be elliptical shape in planar view. Further, as shown in FIG. 2, the absorber 4 is sandwiched and fixed between the top sheet 2 and the back sheet 3, and the shape in plan view is an elliptical shape that is substantially similar to the top sheet 2 and the back sheet 3. It is. It is preferable that the absorbent body 4 is not joined to the back sheet 3 from the viewpoint of separating the absorbent body 4 and the back sheet 3 by the water flow of the flush toilet when the article 1 is discarded in the flush toilet after use. In addition, it is preferable that the absorbent body 4 is partially bonded to the top sheet 2 with a water-soluble adhesive from the viewpoint of maintaining the rigidity of the absorbent body 4 in a wet state when the article 1 is used.

In the absorbent article 1 of the present embodiment, the surface sheet 2 and the back sheet 3 that is a leak-proof layer extend from the periphery of the absorbent body 4 as shown in FIGS. They are bonded together using an adhesive and a heat seal as a physical bonding means.
The water-soluble adhesive is preferably continuously applied to the peripheral portion of the back sheet 3 of the article 1 from the viewpoint of maintaining a bonded state in a wet state when the absorbent article is used. The water-soluble adhesive is preferably applied to the peripheral portion of the article 1 with a certain width, and specifically, applied to the entire surface on the skin contact surface side of the back sheet 3 including the peripheral portion. It is preferable that it is applied to at least the peripheral edge of the back sheet 3. Actually, from the viewpoint of covering the entire back sheet 3 including the peripheral portion and not making the article 1 hard, spiral spray, slot spray, an appropriately spaced linear pattern or a combination thereof (for example, a lattice pattern), It is preferable that it is applied to substantially the entire surface of the back sheet 3 in a pattern having a gap such as a dot pattern. When the article 1 is discarded in a flush toilet and subjected to agitation by a large amount of water, the water-soluble adhesive dissolves in water, and the adhesion between the top sheet 2 and the back sheet 3 by the adhesive disappears.

On the other hand, the embossed portion 6 by heat sealing, which is the physical joining means, has a short linear shape, and the adhesive is applied along the peripheral edge of the article 1 at a position inside the peripheral edge. A plurality of discontinuous areas are provided.
Specifically, in the embossed portion 6, the top sheet 2 and the back sheet 3 are partially fused as described below.
The top sheet 2 and the back sheet 3 were embossed in a dotted line shape having a length of 5 mm, a width of 1 mm, and a line spacing of 2 mm as an emboss pattern, and were pushed from the front side (at a temperature of 100 degrees or more, preferably 110 to 140 degrees) It is physically joined by an embossed portion 6 formed in a pattern.
As described above, the bonding between the top sheet 2 and the back sheet 3 in the peripheral portion is performed by both the water-soluble adhesive and physical bonding means such as embossing.
In this case, the physical bonding is performed by increasing the adhesion effect of the water-soluble adhesive by press-contacting the materials, and forming the surface sheet 2 and the back sheet 3 with the water-soluble adhesive by pressing and heating. Adhesion is enhanced on both sides of penetration into the non-woven fabric and increased adhesion by engagement effect.
Here, in the adhesion of the peripheral portion, the water-soluble adhesive alone or the physical (for example, thermal) bonding means alone does not provide sufficient adhesion to withstand use, and the combination of the two leads to sufficient adhesion. That is important.
That is, as will be described later, the top sheet 2 and the back sheet 3 use a water-decomposable non-woven fabric, and therefore generally have poor heat-fusibility (or as a sheet that can be preferably used).
As described later, various adhesives can be selected as the water-soluble adhesive, but all of them are hard and poor in surface tackiness, and it is necessary to apply a large amount in order to achieve sufficient adhesiveness alone. The part becomes hard and the feeling of use is impaired.
When both are used together, a small amount of liquid in use is in contact with the seal portion at the periphery due to embossing, so moisture cannot enter, while on the other hand, a large amount of liquid invades from everywhere The water-soluble adhesive is washed away, so that the adhesive force between the sheets is remarkably lowered, and the seal is easily released by the force of the water flow.

The absorbent sheet 1 according to this embodiment will be further described. The top sheet 2 is a water-decomposable nonwoven fabric formed by a hydroentanglement method. After this article 1 is discarded in the flush toilet after use, and the topsheet 2 is separated from the backsheet 3 over part or all by the water flow of the flush toilet, the topsheet 2 is a fiber forming a sheet. It is preferable to have a property of decomposing to a level size, and at least the size of each part after hydrolyzing the sheet 2 is decomposed to a size that does not clog a filter medium such as a septic tank. It is preferable. In the present specification, water degradability means a property that does not hydrolyze in a wet state during use of the absorbent article 1, but rapidly decomposes finely when discarded and stirred in a large amount of water.
Moreover, the back sheet 3 in the absorbent article 1 of this embodiment has biodegradability. When this article 1 is discarded in a flush toilet after use, after the back sheet 3 is separated from the top sheet 2 by the water flow of the flush toilet, the back sheet 3 is further biodegraded and its shape disappears. have.

The absorbent body 4 in the absorbent article 1 of the present embodiment is formed from a layer made of a water-decomposable sheet, and the water-decomposable sheet is made of absorbent hydrolyzed paper. As shown in FIG. The water repellent finish is partially applied in a grid pattern.
More specifically, the absorbent body 4 is provided with a water repellent coating portion 41 coated with a water repellent. In the longitudinal direction of the absorbent body 4, the water repellent coating part 41 extends continuously along the longitudinal direction to the front and rear end portions thereof, and is provided at predetermined intervals along the width direction. Moreover, in the width direction of the absorber 4, it extends over the both ends along the width direction, and is provided at predetermined intervals along the longitudinal direction. Further, the linear portions along the longitudinal direction and the width direction are orthogonal to each other.
The absorbent body 4 is preferably coated with a water repellent so as to form a plurality of partially closed shapes by the water repellent coating portion 41. In the present embodiment, the absorbent body 4 has a plurality of substantially rectangular closed shapes by the water repellent coating part 41 as shown in FIG.
Further, the water repellent agent in the water repellent coating portion 41 immerses the entire thickness direction of the absorbent body 4 from the viewpoint of maintaining the structure of the absorbent body 4 in a wet state when the article 1 is used. It is preferable that
The absorbent body 4 preferably has a basis weight of 30 to 200 g / m ² and more preferably 40 to 150 g / m ² from the viewpoint of securing sufficient absorbency and wet rigidity. . The absorbent body may be a single sheet, or may be a laminate of a plurality of sheets having a predetermined basis weight. In the case of a plurality of sheets, it is preferable that the water repellent finish is applied to all sheets, but sheets that are not subjected to the water repellent finish may be mixed.

While the distance between the linear portions along each of the longitudinal direction and the width direction forming the water repellent coating portion 41 is maintained in the wet state when the absorbent auxiliary sheet 1 is used, the rigidity of the sheet is maintained. When it is discarded in the flush toilet after use, it is preferably 4 to 15 mm from the viewpoint of quick water dissolution. Moreover, it is preferable that the width | variety of the linear part along the longitudinal direction and the width direction which respectively forms the water repellent coating part 41 is 1-5 mm from the same viewpoint.
In addition, the presence or absence of water-repellent processing and the coating pattern of the water-repellent agent are obtained when water containing an appropriate colorant, for example, a 0.03% aqueous solution of methylene blue is sprayed from the surface of the absorber sheet by spraying. It can be easily confirmed by visually confirming the coloring. At this time, the water-repellent processed portion is less likely to penetrate the liquid, so that the coloring is lighter, and the non-processed portion is darkly colored.

The absorbent article 1 of the present embodiment will be further described. As shown in FIGS. 1 and 4, the skin contact surface side of the absorbent layer 10 is a mountain along the longitudinal center line C of the absorbent article 1. Thus, the non-skin contact surface side of the leak-proof layer 11 is folded in two so as to form a valley, and the non-skin contact surfaces of the leak-proof layer 11 are water-soluble at the center in the longitudinal direction. Partially bonded by an adhesive.
More specifically, in the packaged state, the article 1 is folded in two so that the non-skin contact surfaces of the back sheet 3 overlap each other. Moreover, when it takes out from packaging at the time of use, the non-skin contact surfaces of the back sheet 3 in the article 1 are in the natural state, as shown in FIG. Are separated from each other, and the inner sides in the width direction of the non-skin contact surfaces are close to each other. In this specification, as described above, the double fold includes a state in which the non-skin contact surfaces are overlapped and folded into two and a state in which the non-skin contact surface is opened in a fan shape as shown in FIG.
It is also preferable to use an adhesive that exhibits non-tackiness when wet instead of the water-soluble adhesive. Examples of adhesives that are non-tacky when wet include styrene-isoprene-styrene block copolymer (SIS), styrene-butadiene-styrene block copolymer (SBS), and styrene-ethylene-butylene-ethylene copolymer. Among adhesives containing (SEBS) or the like as a main component (base polymer), hydrogenated petroleum resin as a tackifier, and paraffin oil or paraffin wax as a plasticizer, there are few plasticizer components / tackifier Many types of adhesives that are hard and hard and have an adhesive strength with surface tack are preferably used for this purpose. As an example, an adhesive having 50% by weight of SEBS, 18% by weight of a plasticizer, and 32% by weight of a tackifier may be mentioned. Since this adhesive is hard when spiral sprayed or slot sprayed, it is difficult to bite into the material and the engagement effect is weak, but the surface tack is large (so-called stickiness), so it has strong adhesion when dried To express. However, since the surface tack caused by hydrogenated petroleum resin is not wetted, the adhesive force is quickly reduced when the toilet is inserted. The preferable composition is preferably 50% by mass or less of the base polymer, 20% by mass or less of the plasticizer, and 30% by mass or more of the tackifier.
In addition, the thickness when this article 1 is developed in a flat shape is a state in which the non-skin contact surfaces of the back sheet 3 are removed from each other at the bonding portion 5 and developed.

As shown in FIG. 5, the absorbent article 1 of this embodiment is sandwiched between spaces between labia of a woman, and the skin contact surface of the article 1 is preferably worn in close contact with the labium. The The article 1 has a thickness of 5.5 mm or less, preferably 2.0 mm or less, more preferably 1.8 mm or less, is thin and soft, and deforms and contacts flexibly according to the shape of the surface between the labia. Since this article 1 is used with a mountain-folded ridge portion arranged behind the labia of a woman, the excreted body fluid moves in the longitudinal direction along the ridge portion. Absorption of bodily fluid is made by the entire article 1. Further, since the ridge portion has a round cross section as shown in FIG. 1 due to the elasticity of the material, it is difficult to cause discomfort and pain when pushed. Further, although not clearly shown in FIG. 4, the sheet has a constricted shape due to the fixation on the back surface side, so that it is easily sandwiched between the labia.
The thickness is measured under a load of 2.5 g / cm ² by placing a measuring plate of an appropriate size by using a table thickness gauge made by Peacock, for example.
When the article 1 is worn, a finger is inserted between the non-skin contact surfaces of the back sheet 3 that is folded in the valley to support the article 1 with the finger, and the article 1 is placed between the labia in this state. It is preferable to wear it sandwiched between two spaces.
Moreover, when using the absorbent article 1 of this embodiment, it is also preferable to use together with the normal absorbent article used by fixing to the inner side of an underwear from a viewpoint of improving the absorption performance of a bodily fluid.

The absorbent article 1 of this embodiment is sandwiched between spaces between labia of a woman and closely contacts the wall of the labia to prevent leakage of bodily fluids, and when disposed in a flush toilet after use, From the viewpoint of not clogging the septic tank or the sewer, etc., the size of each of the top sheet 2, the absorber 4 and the back sheet 3 as constituent members does not exceed 12 cm in length, 6 cm in width, and 0.5 cm in thickness. It is preferable that it becomes a magnitude | size. The length and the width are the maximum values in the longitudinal direction or the width direction when the sheet 1 is developed in a planar shape (the same applies hereinafter).
In the present embodiment, the absorbent body 4 is formed only from one piece of water-disintegrating paper, but it is also preferable that the absorbent body 4 is formed from a plurality of members. As described above, it is preferable to separate into a size not exceeding 12 cm in length, 6 cm in width, and 0.5 cm in thickness by the water flow of the toilet. In addition, these numerical values are dimensions in a state in which each constituent member of the article 1 is separated, and are not in a state in which the constituent members form the article 1.

In the absorbent article 1 of the present embodiment, the top sheet 2 is formed by forming a web and further forming a nonwoven fabric by a hydroentanglement method.
As the web material, various known materials can be used, but those obtained by forming a web from thermoplastic fibers, hydrophilic fibers, or mixed fibers of both are preferred. The fiber length of each fiber may be 6 to 120 mm from the viewpoint of quick water disintegration when discarded in a flush toilet after use while the sheet is maintained in a wet state when the article 1 is used. preferable.
Specific examples of thermoplastic fibers include polyolefins such as polyethylene and polypropylene, polyesters such as polyethylene terephthalate, synthetic fibers made of resins such as polyamide, composite fibers thereof, and durable hydrophilizing agents for these fibers. A coated fiber or the like is preferable.
Specifically, the hydrophilic fiber is preferably wood pulp, cellulose fiber, regenerated cellulose fiber, or fiber containing a mixed fiber thereof. Wood pulp includes bleached wood pulp such as softwood bleached kraft pulp (NBKP), softwood sulfite pulp (NBSP), hardwood bleached kraft pulp (LBKP), etc., mercerized pulp subjected to chemical treatment and alkali swelling, spiral structure Chemically cross-linked pulp having Examples of cellulose fibers include cotton fibers. Examples of the regenerated cellulose fiber include fibers obtained by a viscose method, a copper ammonia method, and an organic solvent method. For example, rayon fibers formed by the viscose method can be preferably used.
Further, it is more preferable to form the web by using a biodegradable fiber, which will be described later, or a fiber made of a biodegradable resin, in addition to the naturally degradable fiber such as the hydrophilic fiber. Examples of the water-degradable sheet having biodegradability include those described in Table 97/13920.
As the water-decomposable non-woven fabric, it is also preferable to use a non-woven fabric made of the web by a chemical bond method using a water-soluble adhesive.
In addition, a sheet in which a water-soluble adhesive is applied and penetrated into a non-woven sheet by the hydroentanglement method to reinforce the bond is also preferable. Examples of this binding reinforcing agent include those obtained by adding polyvinyl alcohol as a binding reinforcing agent, those obtained by adding polyvinyl alcohol as a binding reinforcing agent, and further impregnated with a carboxylic acid salt (aqueous solution) and dried. 3 to 0.6, pH ≧ 5 carboxymethylcellulose and / or salts thereof added as a binding reinforcing agent, etc. are raised, and these are not dissolved in water for a small amount of water as a stable binding agent When a large amount of water permeates in the flush toilet, the bond breaks immediately due to structural changes such as the metal cross-links of the salt being removed, and the water is dissolved.

In the absorbent article 1 of the present embodiment, various known materials can be used as the material of the leak-proof back sheet 3 having biodegradability, but a biodegradable film or biodegradable paper or biodegradable can be used. A non-woven fabric coated with wax is preferable. The wax is preferably biodegradable.
Specifically, as the biodegradable film, a film formed from an aliphatic polyester, a copolymer of an aliphatic polyester and an aromatic polyester, or an aliphatic polycarbonate resin can be preferably used. The resin includes polyethylene succinate (PES), polybutylene succinate (PBS), polylactic acid (PLA), polyglycolic acid (PGA), polyhydroxybutyrate (PHB), polycaprolactone (PCL). , A mixture or copolymer of polycaprolactone and polybutylene succinate (PCL / PBS), a copolymer of polyhydroxybutyrate and polyhydroxyvalerate (PHB / PHV), polybutylene succinate and polybutylene adipate A resin such as a mixture or copolymer (PBS / PBA), a copolymer of polyethylene terephthalate and polyethylene succinate (PET / PES), or a copolymer of polybutylene terephthalate and polybutylene adipate (PBT / PBA). preferable.
Also, water-insoluble polysaccharides such as cellophane and chitosan, cellulose derivatives such as cellulose acetate, unvulcanized natural rubber, unvulcanized polyisoprene, heat-cured shellac resins, and cured Natural resins, polyvinyl alcohol resins, polysaccharides such as starch, proteins such as gelatin, polymalic acid, polyglutamic acid, polyaspartic acid and the like are also preferable.
Each said resin can be used individually or in combination of 2 or more.

  For forming a biodegradable film, a conventional film forming method such as a calendar method, a melt extrusion method, a method of evaporating a solvent or a dispersion medium after applying a resin solution or an emulsion, and the like is used. Can do.

  The thickness of the biodegradable film is preferably 12 to 50 μm, more preferably 20 to 40 μm, from the viewpoints of film strength and film handleability and ease of biodegradability.

The biodegradable paper is preferably formed by adding an adhesive to a web containing natural fibers, chemical fibers having biodegradability, or a mixture of both, and the web is particularly formed from hydrophobic fibers. It is preferable. Moreover, as this adhesive agent, what has biodegradability is preferable.
Examples of natural fibers include plant fibers and animal fibers. Specific examples of plant fibers include seed hair fibers (cotton), bast fibers (juju, cannabis, flax, linseed, and cannabis), and leaf vein fibers (manila hemp and sisal). Specific examples of animal fibers include silk, wool, cashmere, goat, alpaca, and horse hair. Examples of biodegradable chemical fibers include regenerated fibers and biodegradable synthetic fibers. Specifically, the regenerated cellulose fiber is used as the regenerated fiber. Specifically, as the synthetic fiber having biodegradability, a fiber made of the above-described resin is used as a material for the biodegradable film.
Various known biodegradable webs can be used, but the biodegradable fibers are preferably used alone or in combination of two or more.
As the biodegradable nonwoven fabric, various known ones can be used. The biodegradable web is formed by chemical bond method or hydroentanglement method, and contains heat-fusible fibers. Those formed by the method are preferred. In the chemical bond method, it is preferable to use an adhesive having biodegradability, and in the air-through method, it is preferable to use a heat-fusible fiber having biodegradability. Moreover, what was formed by the spunbond method using only the biodegradable synthetic fiber which has thermoplasticity is also preferable.

  The biodegradable film, biodegradable paper, biodegradable web or biodegradable nonwoven fabric described above is biodegradable (aerobic ultimate biodegradability: JIS K 6950 or 6953) from the viewpoint of degrading in a practical period. ) Is preferably 30% or more, more preferably 50% or more, and even more preferably 60% or more.

Various known waxes can be used as the biodegradable wax, but plant waxes, animal waxes, petroleum waxes and the like are preferable.
Specific examples of the plant wax include rice wax, carnauba wax, and candelilla wax. Specific examples of animal waxes include beeswax, lanolin, and whale wax. Specific examples of the petroleum wax include those having a melting point of 85 ° C. or less, such as microcrystalline wax and paraffin wax. Moreover, even if it is a synthetic wax, what has biodegradability can be used. The wax is preferably applied to the skin contact surface side of biodegradable paper or biodegradable nonwoven fabric.

  In the absorbent article 1 of the present embodiment, various known materials can be used as the absorbent 4 that is hydrolytic paper, but water-soluble adhesive is applied to a web containing hydrophilic fibers, thermoplastic fibers, or a mixed fiber of both. Those formed by adding an agent are preferred. The absorbent body 4 is preferably formed from hydrophilic fibers from the viewpoint of good absorbency, and is preferably formed from hydrophobic synthetic fibers from the viewpoint of good softness. From the viewpoint of combining good absorbency and softness, the mass ratio of the hydrophilic fiber to the hydrophobic synthetic fiber is preferably 100: 0 to 60:40. In addition, the fiber length of each fiber is 6 to 120 mm from the viewpoint of quick water disintegration when discarded in a flush toilet after use while maintaining the rigidity of the absorbent body 4 in a wet state when the article 1 is used. It is preferable that

Examples of the hydrophilic fiber and the hydrophobic synthetic fiber that form the absorbent body 4 include the same materials as those described above as the material of the topsheet 2.
In addition, it is more preferable to form hydrolytic paper using the above-described fibers having biodegradability or fibers made of a resin having biodegradability and having hydrophilicity. Examples of the hydrolytic paper having biodegradability include those described in Table No. 97/13920.
Moreover, it is also preferable to use together the constituent member of the absorber currently formed from the web or the water-disintegratable nonwoven fabric with water-disintegrating paper. Examples of the fibers forming the web or the water-decomposable nonwoven fabric include the same materials as those described above as the material of the topsheet 2. In this case as well, the web or the water-decomposable nonwoven fabric is formed using the above-described biodegradable fiber or fiber made of a biodegradable resin and having hydrophilicity. preferable.
Furthermore, it is also preferable to carry a predetermined amount of superabsorbent polymer from the viewpoint of improving absorbability. Specifically, from the viewpoint of fluidity after disposal in the flush toilet, it is preferable to carry the superabsorbent polymer in an amount of 0 to 33% by mass with respect to the mass of the absorber.
Various resins known to those skilled in the art can be used for the superabsorbent polymer, but considering biodegradation after being discharged into the environment,
1) Polymers based on biodegradable polymers such as starch, cellulose, carboxymethyl cellulose and their salts, and graft polymerization of acrylic acid and acrylate
2) It is insoluble in menstrual blood, urine, etc. (electrolyte solution), such as polyacrylic acid (or its salt) with low degree of crosslinking and weak gel strength, salt obtained by partially neutralizing polyacrylic acid with a small amount of polyvalent cation, etc. Synthetic polymers that are water soluble when exposed to large amounts of water
3) Polymers having high biodegradability such as superabsorbents derived from natural products such as starch, insolubilized starch, carrageenan, carboxymethylcellulose and salts thereof, natto-produced polyglutamic acid and cross-linked products thereof are particularly preferably used.
Further, the superabsorbent polymer is preferably a fibrous polymer from the viewpoint of being easily dispersed and supported on the sheet material constituting the absorber (as described later, a part of the absorber has a wood pulverized pulp layer). In this case, it is possible to disperse and support a granular or powdery polymer in this layer).

  In the absorbent article 1 of the present embodiment, various known adhesives are used as the water-soluble adhesive. For example, an anionic binder having a carboxyl group, polyvinyl alcohol, starch or a derivative thereof, sodium alginate, tant gum, Guar gum, xanthan gum, gum arabic, carrageenan, galactomannan, gelatin, casein, albumin, pull plan, polyethylene oxide, viscose, polyvinyl ethyl ether, sodium polyacrylate, sodium polymethacrylate, polyacrylamide, polyacrylic acid hydroxylation Derivatives, polyvinyl pyrrolidone / vinyl pyrrolidone vinyl acetate copolymer and the like are preferred. Examples of the anionic binder include polysaccharide derivatives, synthetic polymers, and natural products. Examples of the polysaccharide derivative include carboxymethyl cellulose (CMC) or a salt thereof, carboxyethyl cellulose or a salt thereof, carboxymethylated starch or a salt thereof, and an alkali metal salt of carboxymethyl cellulose is particularly preferable. Examples of the synthetic polymer include a salt of an unsaturated carboxylic acid polymer or copolymer, a salt of a copolymer of an unsaturated carboxylic acid and a monomer copolymerizable with the unsaturated carboxylic acid, and the like. Examples of the unsaturated carboxylic acid include acrylic acid, methacrylic acid, itaconic acid, crotonic acid, maleic anhydride, maleic acid, and fumaric acid. Examples of monomers that can be copolymerized with these include esters of these unsaturated carboxylic acids, vinyl acetate, ethylene, acrylamide, and vinyl ether. Examples of natural products include xanthan gum, gellan gum, tarragant gum, and pectin. Among these, in addition to the viewpoints of water solubility and adhesive strength when wet, from the viewpoint of easy application of melt coating, such as spiral spraying, which is easy for those skilled in the art, water-soluble thermoplastics mainly composed of polyvinyl alcohol. The adhesive is preferred.

  In the absorbent article 1 of the present embodiment, various known adhesives are used as biodegradable adhesives. Starch, polyvinyl alcohol, glue, gelatin, casein, unvulcanized natural rubber, unvulcanized Of these, polyisoprene is preferred.

  Moreover, it is also preferable to add a crosslinking agent to a water-soluble adhesive as needed. As a result of crosslinking and insolubilizing the adhesive by the crosslinking agent, the adhesive cannot be dissolved with a small amount of water. However, when discarded in a large amount of water, the insolubilized adhesive will be dissolved again in water. As the type of the crosslinking agent, an appropriate one is used according to the type of the adhesive. For example, when the adhesive is a water-soluble adhesive having a carboxyl group such as CMC described above, polyvalent metal ions are preferably used as the crosslinking agent. In particular, it is preferable to use one or more metal ions selected from the group consisting of alkaline earth metals, manganese, zinc, cobalt and nickel from the viewpoints of water solubility and adhesive strength when wet.

  In the absorbent article 1 of the present embodiment, various known water repellents that form the water repellent coating portion 6 of the absorbent body 4 are used, and silicone oligomers, fluorine oligomers, and the like are preferable. Specific examples of the silicone oligomer include polymethylsilicone obtained by substituting a part of its methyl group with a phenyl group or a trifluoropropyl group, and polyfluorosilicone. Specific examples of the fluorine oligomer include a polymer of an acrylic ester of alcohol containing a perfluoroalkyl group or a phosphate ester.

According to the absorbent article 1 of the present embodiment described above, the topsheet 2 and the backsheet 3 are joined together using a water-soluble adhesive and heat seal, so that the wetness when the absorbent article 1 is used. In this state, a sufficient joined state is maintained. On the other hand, when it is discarded in the flush toilet after use, it is quickly separated into the top sheet 2 and the back sheet 3.
Further, since the water-repellent paper as the absorbent body 4 is coated with a water-repellent agent in a lattice shape, the rigidity is maintained in the wet state when the absorbent article 1 is used, but it is discarded in the flush toilet after use. In this case, since water is dissolved by stirring with a large amount of water flow, clogging of water pipes and septic tanks is not caused.
Moreover, since the surface sheet 2 has water decomposability and the back surface sheet 3 has biodegradability, it is decomposed | disassembled small continuously after each separating with the water flow of a flush toilet.
In addition, when the top sheet 2 and the absorbent body 4 have biodegradability as well as water decomposability, it is decomposed to below the size of the fiber, so finally, in the downstream of the flush toilet such as a septic tank, The ratio remaining as a solid is extremely small, which is more suitable for the environment.
In addition, since the non-skin contact surfaces of the back sheet 3 are bonded and fixed together with a water-soluble adhesive, when discarded in a flush toilet after use, the adhesive melts and the non-skin contact surface side opens. The surface sheet 2 and the back sheet 3 are quickly separated from each other by stirring with a large amount of water flow. In addition, when stirring by a water flow is strong, etc., separation | separation with the surface sheet 2 and the back surface sheet 3 may occur first before this adhesive agent melt | dissolves.
Furthermore, since the number of constituent members is small and the configuration is simple, the production of the article 1 is easy.

  Next, the absorbent article 1 of 2nd-4th embodiment is demonstrated, referring FIG.6 and FIG.7. Regarding the second to fourth embodiments, the description in detail regarding the first embodiment is appropriately applied to points that are not particularly described. Moreover, in FIG.6 and FIG.7, the same code | symbol is attached | subjected to the same member as FIGS.

In the absorbent article 1 according to the second preferred embodiment of the present invention, the topsheet 2 is biodegradable.
In the absorbent article 1 of the present embodiment, various known materials can be used as the material of the liquid-permeable surface sheet 2 having biodegradability, but biodegradable films, biodegradable paper, biodegradable materials can be used. A web or a biodegradable nonwoven fabric is preferred. These sheet materials are preferably provided with a plurality of holes so that the body fluid can pass therethrough.
Examples of the material of the biodegradable film, biodegradable paper, biodegradable web, or biodegradable nonwoven fabric include the same materials as those of the back sheet of the first embodiment. In addition, as a material for the biodegradable paper, hydrophilic fibers are also preferable.

  According to the absorbent article 1 of the present embodiment, the top sheet 2 has biodegradability and is finally decomposed to a size equal to or less than the size of the fiber, so that it is solid downstream of the flush toilet such as a septic tank. The ratio remaining as a product is extremely small, which is suitable for the environment.

In the absorbent article 1 according to the third preferred embodiment of the present invention, the topsheet 2 and the absorbent body 4 are biodegradable.
In the absorbent article 1 of the present embodiment, examples of the material of the liquid-permeable surface sheet 2 having biodegradability include the same materials as those of the second embodiment.

In the absorbent article 1 of the present embodiment, various known materials can be used as the material of the absorbent 4 having biodegradability, such as biodegradable paper, biodegradable web, or biodegradable nonwoven fabric. Is preferred.
When biodegradable paper is used, the material is preferably formed by adding an adhesive to a web made of hydrophilic biodegradable fibers. Examples of hydrophilic biodegradable fibers include those having hydrophilicity among the biodegradable fibers described above,
Specifically, various fibers described as cotton fibers (cotton flowers) and hydrophilic fibers that are the materials of the hydrolytic paper of the first embodiment are used.
When a biodegradable web is used, the material is preferably formed from hydrophilic biodegradable fibers. Examples of hydrophilic biodegradable fibers include those described above for the biodegradable paper.
The biodegradable nonwoven fabric is preferably formed from the biodegradable web by a chemical bond method or a hydroentanglement method, or by a heat-fusible fiber and formed by an air-through method. In the chemical bond method, it is preferable to use an adhesive having biodegradability, and in the air-through method, it is preferable to use a heat-fusible fiber having biodegradability. Moreover, what was formed by the spunbond method using only the biodegradable synthetic fiber which has thermoplasticity is also preferable.

  According to the absorbent article 1 of the present embodiment, the topsheet 2 and the absorbent body 4 are biodegradable, so that they are decomposed below the size of the fiber. In the downstream of the toilet, the proportion remaining as a solid matter is extremely small, which is more suitable for the environment.

As shown in FIGS. 6 and 7, in the absorbent article 1 of the fourth preferred embodiment of the present invention, both side portions in the longitudinal direction of the article 1 are curved toward the skin side of the wearer. Bends are provided along the longitudinal direction at positions on the inner side in the width direction of both sides in the longitudinal direction of the article 1. The bending habit is formed by a known method such as heat sealing.
According to the absorbent article 1 of the present embodiment, since both sides in the longitudinal direction of the article 1 are curved toward the wearer's skin, the article 1 is worn when the absorbent article 1 is worn. Since it contacts along a wearer's skin, fit property and leak-proof property are improved over the width direction of the excretion part vicinity.

The absorbent article of the present invention is not limited to the above-described embodiment, and can be appropriately changed without departing from the gist of the present invention.
For example, it is also preferable to provide a fixing adhesive portion for fixing to the underwear or the like on the non-skin contact surface side of the back sheet in the absorbent article of the present invention. In particular, when used in combination with conventional absorbent articles fixed to underwear, the absorbent article of the present invention is the skin contact surface of the absorbent article fixed to the underwear through the adhesive portion during wearing Fixed to. Therefore, when exchanging the absorbent article of the present invention, the undergarment can be lowered and the article can be removed from between the labial areas, which is preferable because the exchange is easy.

  Moreover, in each embodiment, the double-folded form of the absorbent article of the present invention is maintained by a shape-retaining sheet that is stretched between both longitudinal sides of the non-skin contact surface, and the shape-retaining sheet Has water-decomposability and / or biodegradability, and both the longitudinal sides of the shape-retaining sheet and the longitudinal sides of the non-skin contact surface are bonded with a water-soluble adhesive. Is preferable from the viewpoint of maintaining the folded form of the article. In that case, it is preferable that the shape retaining sheet has water decomposability and / or biodegradability.

Moreover, in each embodiment, although the adhesion part of the non-skin contact surfaces of a back surface sheet was provided in the center part of the longitudinal direction, you may provide in one edge part of the longitudinal direction of an absorbent article. .
In each embodiment, the top sheet and the back sheet are joined by a plurality of embossed parts by heat sealing as physical joining means, but may be an embossed part by ultrasonic sealing, or by engagement with a pin or a needle. There may be.
In each embodiment, although the back sheet had biodegradability, it may have water decomposability. Furthermore, the back sheet may have water decomposability and biodegradability. Furthermore, it is also preferable that the back sheet as the leak-proof layer is water-soluble.
In each embodiment, each constituent member of the absorbent article has water decomposability and / or biodegradability, but each constituent member may be separated by a water flow in a flush toilet. Or biodegradability.
Moreover, in each embodiment, although the lattice pattern of the water repellent coating part in an absorber was provided along the longitudinal direction or the width direction of an absorbent article, it does not need to follow.
Moreover, although the surface sheet in 1st Embodiment was a water-degradable nonwoven fabric, water-degradable paper or the surface sheet in 1st Embodiment was a water-degradable nonwoven fabric, Also good. Furthermore, although the absorbent body in 1st Embodiment used the hydrolytic paper, you may use the component member of the absorbent body formed from the water-degradable web or the water-degradable nonwoven fabric individually or in combination. For example, a cotton-like pulp layer made of pulverized wood pulp may be included in a part of the configuration. Although the absorber in the first embodiment has water decomposability, it may have only biodegradability without having water decomposability.
Further, in the embodiments, the folded shape (three-dimensional shape) is formed in advance, but the absorbent auxiliary sheet of the present invention does not include a three-dimensionally formed (water-decomposable) adhesive or a shape-retaining sheet, and has a planar shape. You may be doing. In this case, the user himself / herself folds it into a predetermined shape and uses it. For this reason, it is more preferable to add a pattern, printing, embossing, etc. that serves as a guideline for the center line (for example, the vertical center line). When forming a fold line with embossing, the fold line is bent sharply, In order to prevent pain, it is more preferable to devise methods such as placing a plurality of embossed lines at the periphery of the center folding position, and placing a discontinuous embossed pattern such as a dot shape in the center region.
The absorbent article of the present invention may be a menstrual absorption pad or an incontinence pad.
The description omitted in one embodiment described above and the requirements of only one embodiment can be applied to other embodiments as appropriate, and the requirements in each embodiment can be appropriately changed between the embodiments. Can be substituted.
Moreover, although the example which coats a water repellent with a predetermined pattern was disclosed to the sheet | seat used for an absorber, it is also possible to comprise an absorber by combining the sheet | seat which is not coated with a water repellent.

FIG. 1 is a perspective view showing a first embodiment of an absorbent article of the present invention. 2 is a cross-sectional view taken along line XX of FIG. FIG. 3 is a plan view of the absorbent body in the absorbent article according to the first embodiment. FIG. 4 is a cross-sectional view taken along line YY of FIG. FIG. 5 is a cross-sectional view schematically showing a state in which the absorbent article of the first embodiment is worn along the line XX in FIG. 1. FIG. 6 is a perspective view showing a fourth embodiment of the absorbent article of the present invention. 7 is a cross-sectional view taken along the line ZZ in FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Absorbent article 10 Absorbent layer 11 Leak-proof layer 2 Top sheet 3 Back sheet 4 Absorber 41 Water repellent coating part 5 Adhesion part 6 Embossed part C Vertical center line

Claims (7)

An absorbent article comprising an absorbent layer and a leak-proof layer and used between the labia,
The thickness when deployed in a plane is 5.5 mm or less, and the absorption layer and the leak-proof layer are separated by a water flow in a flush toilet ,
The absorbent layer is formed from a top sheet and a water-degradable sheet that is a part of the water-repellent finish that is an absorbent, and the absorbent is between the top sheet and the leak-proof layer. Are arranged in the
The absorbent layer and the leak-proof layer are bonded at the peripheral edge of the absorbent article using a water-soluble adhesive and a physical bonding means applied continuously to the peripheral edge . Goods. The absorbent article according to claim 1 , wherein the absorbent body is not joined to the leak-proof layer . The absorbent article according to claim 1 or 2, wherein the water-repellent sheet is provided with the water-repellent finish in a lattice shape. The absorbent article according to any one of claims 1 to 3, wherein the absorbent body is partially bonded to the topsheet with a water-soluble adhesive .   The absorbent article according to any one of claims 1 to 4, wherein each of the absorbent layer and the leak-proof layer has water decomposability and / or biodegradability.   Along the longitudinal center line of the absorbent article, the absorbent layer is folded in two so that the skin contact surface side of the absorbent layer is a mountain, and the non-skin contact surface side of the leak-proof layer is a valley, The absorbent article according to any one of claims 1 to 5, wherein the non-skin contact surfaces of the leak-proof layer are partially bonded to each other with a water-soluble adhesive. The absorbent article according to any one of claims 1 to 6, wherein the absorbent article is an interlabial pad used by being sandwiched between female labia.

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