JP4721793B2 - 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 has a small component and a relatively small number of components. Therefore, it is considered that water washability is easily realized.

  In addition, in the wet state while wearing, it has a body fluid leak-proof without being decomposed, and after discarding the absorbent article in the flush toilet after use, the back sheet does not remain in its original form. An interlabial pad absorbent article has also been proposed that has the ability to be washed with water that does not impair the function of the septic tank by being dispersed in the sheet piece.

  For example, in Patent Document 1, an absorber is provided between a liquid-permeable top sheet and a liquid-impermeable back sheet, and the back sheet is composed of two sheet pieces, and the adjacent sheet pieces The overlapping portions in the longitudinal direction are formed so as to overlap each other, and the overlapping portions in the longitudinal direction are arranged at positions where the end portions of the sheet pieces located on the body surface side are separated from the longitudinal center line. Absorbent articles that are superimposed on each other are disclosed.

JP 2004-261230 A

  In the absorbent article described in Patent Document 1, the two liquid-impermeable sheet pieces forming the back sheet are joined to each other by an adhesive at the overlapping portion, so the absorbent article is discarded in the flush toilet In this case, even if the adhesive is water-soluble, it is difficult for water to penetrate into the adhesive, so that it may be difficult to disassemble into individual sheet pieces. On the other hand, since the absorbent article absorbs body fluid and becomes wet during wearing, the water-soluble adhesive may melt and the two sheet pieces may be separated from each other.

  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 by reliably decomposing after use, and which does not decompose during use.

  The present invention includes a top sheet, a back sheet, and an absorbent body interposed between the two sheets, and is a substantially vertically long absorbent article, which can start tearing at the peripheral portion of the absorbent article. The above object is achieved by providing an absorbent article that has a portion and is capable of tearing the absorbent article so that the absorbent body is exposed, starting from the division start portion.

  According to the absorbent article of the present invention, it is used by being sandwiched between the labia and can be washed with water by reliably decomposing after use, and does not decompose during use.

  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 to 3, the absorbent article 1 of the present embodiment includes a liquid-retaining top sheet 2, a liquid-impermeable back sheet 3, and an absorbent body 4 interposed between both sheets. It is substantially vertically long. This article 1 is used by being folded in half along the longitudinal direction and sandwiched between spaces between female labia, and is made of a soft material, and flexibly deforms according to the shape of the surface between the labia. Abut.
Moreover, as shown in FIG.1 and FIG.2, the absorbent article 1 of this embodiment has the division | segmentation start part 14 which can become a trigger of tearing in the peripheral part of this article | item 1, and this division | segmentation start part 14 is a starting point. As described above, the absorbent article 1 can be torn so that the absorbent body 4 is exposed. The torn article 1 can be discarded in a flush toilet. 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).
A knob 12 is formed at the front end of the article 1 in the longitudinal direction. The knob 12 is used as a knob when the article 1 is attached to or removed from the body. In the present embodiment, the division start unit 14 is a part of the knob unit 12.

The absorbent article 1 according to this embodiment will be further described. Each of the top sheet 2 and the back sheet 3 has a substantially elliptical shape in plan view as shown in FIG. The top sheet 2 and the back sheet 3 are joined at a portion extending from the periphery of the absorber 4. Further, as shown in FIG. 3, the absorber 4 is sandwiched and fixed between the top sheet 2 and the back sheet 3, and the shape in plan view is a substantially elliptical shape that is substantially similar to the top sheet 2 and the back sheet 3. Shape.
In the absorbent article 1 of the present embodiment, the top sheet 2 is a water-decomposable nonwoven fabric, and the absorbent body 4 also has water-decomposability. Moreover, the back surface sheet 3 has biodegradability.

The division start part 14 in the absorbent article 1 of the present embodiment is a notch formed in the peripheral part of the article 1. The notch is provided at the front end portion in the longitudinal direction of the absorbent article 1, and each of the top sheet 2 and the back sheet 3 has a V-shaped cut at the front end portion in the longitudinal direction as shown in FIG. Notches 23 and 33 are provided. The notch 23 of the top sheet 2 is provided substantially symmetrically with respect to the longitudinal center line C of the article 1, and the V-shaped narrowed tip of the notch 23 is the longitudinal direction of the article 1. It faces the inside of the direction.
The front end portion of the article 1 has a configuration in which a top sheet 2 and a back sheet 3 are laminated, and the front end portion in the longitudinal direction of the back sheet 3 is also V-shaped, which is the same shape as the top sheet 2. A notch 33 is provided, and the contours of the notches of the back sheet 3 and the top sheet 2 are overlapped.
The article 1 is preferably worn with the front end where the split start portion 14 is provided on the abdomen side of the body. When the article 1 is removed from the body after use, the vicinity of the notches 23 and 33 at the front end is removed. Thus, it is preferable to remove the space between the labia.

When the absorbent article 1 of the present embodiment is discarded in the flush toilet after use, it is preferable that the vicinity of the notches 23 and 33 is picked before the disposal and torn as shown in FIG.
The size of the knob 12 that triggers tearing, and the shape and size of the notches 23 and 33 are the overall size of the article 1, ease of removal when it is removed, and when the handle 12 is torn with the knob 12. It can be decided arbitrarily considering the ease of tearing.
From the viewpoint that the article 1 can be taken out satisfactorily, and from the viewpoint that it does not get in the way during mounting, the length of the knob 12 (when measuring from the front end of the absorbent body 4 to the front end of the article 1 along the longitudinal direction) The length is 10 to 30 mm, preferably 12 to 20 mm, the width of the knob 12 base (maximum width, as a guideline), the article 1 is developed in a planar shape, and the article 1 at the front end of the absorbent body 4. The length of the line drawn in the width direction (direction perpendicular to the longitudinal direction) is 10 to 50 mm, preferably 15 to 30 mm.
From the viewpoint of favorably tearing the article 1, it is preferable that the vicinity of the notches 23 and 33 has a form that can be easily picked and can be a trigger for tearing, with respect to the size and shape of the knob portion 12 as described above. . From this viewpoint, the length L (see FIG. 2) along the longitudinal direction of the notches 23 and 33 which are the division start portions 14 is 30% or more, preferably 40% to 70%, with respect to the entire length of the knob portion 12. The interval W (see FIG. 2) between both ends of the bifurcated side facing the outside in the longitudinal direction is 20% or more, preferably 25 to 50%, with respect to the width of the base of the knob 12 and has a wedge shape as a whole. It is easy to understand the meaning of the notch intuitively. As for the specific size of the length L and the width W, the length L is 2 to 20 mm, preferably 5 to 15 mm, and the width W is 2 to 15 mm, preferably 3 to 7 mm.
It should be noted that a cutting line extending in the longitudinal direction can be used as a trigger for tearing instead of the wedge-shaped notch by making it possible to visually recognize the tearing position such as various pattern printing and patterns. At this time, the length L along the longitudinal direction is the same as above, and the width W is 0 mm.

  In the surface sheet 2 in the absorbent article 1 of the present embodiment, a perforation 22 extending over substantially the entire length in the longitudinal direction of the absorbent article 1 has a V-shaped notch 23 that is the division start portion 14. It is provided to extend along the longitudinal direction starting from the narrowed tip. The perforation 22 is along the longitudinal center line of the topsheet 2. The perforation 22 is preferably provided in a portion of the topsheet 2 that is placed on the absorbent body 4. From the viewpoint of preventing the topsheet 2 from tearing while the article 1 is worn, the topsheet 2 It is preferable not to be provided around the article 1 where the back sheet 3 is bonded.

  In the cutout 23 of the topsheet 2 that is the split start portion 14, the topsheet 2 is picked at both ends divided into two branches and pulled toward the skin contact surface side of the topsheet 2 and the other is not By pulling toward the skin contact surface side to give a tearing stress along the longitudinal direction of the topsheet 2 or by pulling the topsheet 2 outward in the width direction, as shown in FIG. It is designed to be torn from side to side.

It is preferable that the topsheet 2 in the absorbent article 1 of the present embodiment does not tear at the perforation 22 in a state where the article 1 is worn. For example, in the notch 23 which is the division start part 14, the two ends divided into two branches are picked, one is pulled toward the skin contact surface side of the top sheet 2, and the other is directed toward the non-skin contact surface side. When pulling and applying a tearing stress along the longitudinal direction to the topsheet 2, it is preferable that the topsheet 2 is torn along the perforations 22 when the tearing stress is at least 28 cN or more, preferably 43 to 300 cN.
The tear stress at which the surface sheet 2 is torn at the perforation 22 is measured by applying the tear test method (the concept of tear direction) specified in JIS-K7128 (plastic film and sheet tear test method) as follows, and the trouser method. It is performed by applying a tearing method called.
A Tensilon tensile tester RTM-25 manufactured by Orientec Co., Ltd. was used for the measurement. Specifically, only the top sheet is taken out from the absorbent article, the distance between the chucks of Tensilon is set appropriately to the extent that each of the split start parts is inserted, and one of the left and right of the notch that is the split start part is the lower chuck. In the same manner, the other of the left and right cutouts was sandwiched between upper chucks, pulled upward at a speed of 300 mm / min, and the tear strength was measured. If the length is clear, such as perforations, the measurement distance is appropriately set within that range. As a temporary measure, it was pulled 30 mm and the maximum stress was taken as the tearing stress.

In the surface sheet 2 of the present article 1, the surface sheet 2 is not torn at the perforations 22 while the surface sheet 2 is pulled well in the vicinity of the notch 23 and is easily torn. From the viewpoint, the length of each cut forming the perforation 22 is 1 to 10 mm, preferably 2 to 8 mm. The space | interval of this each cut | interruption is 0.5-5 mm, Preferably it is 1-3 mm.
Further, as will be described later, for the purpose of exposing the absorber when discarded in a flush toilet, the length covered by the perforation is 40% or more, preferably 50 to 90% with respect to the entire length of the article 1. .

Further, the back sheet 3 in the absorbent article 1 of the present embodiment is formed from a biodegradable resin film that is uniaxially stretched in the longitudinal direction of the article 1 at least twice, preferably 2.5 to 10 times. Has been. The stretched direction of the resin film is made to coincide with the longitudinal direction of the back sheet 3.
Since the uniaxially stretched film is crystallized in the stretching direction, the film is strong in the stretching direction, and the tensile strength and the tearing strength are weak in the direction perpendicular to the stretching direction. Therefore, the back sheet 3 is cut at the notch 33 which is the division start portion 14 and the both ends of the back sheet 3 are gripped, one is pulled toward the skin contact surface side of the back sheet 3 and the other is not applied to the skin. Even if it does not have a special parting line by applying the tearing stress along the longitudinal direction to the back sheet 3 by pulling it toward the contact surface side or pulling the back sheet 3 in the width direction, the back sheet 3 It is easily torn along the longitudinal direction. The back sheet 3 in the present embodiment is torn to the left and right along the longitudinal center line of the back sheet 3 starting from the narrowed tip of the notch 33.

  It is preferable that the back sheet 3 in the absorbent article 1 of the present embodiment does not tear when the article 1 is worn. For example, in the notch 33 which is the division start portion 14, the two ends divided into two forks are picked, one is pulled toward the skin contact surface side of the back sheet 3, and the other is directed toward the non-skin contact surface side. When applying a tearing stress along the longitudinal direction to the back sheet 3 by pulling, it is preferable that the back sheet 3 is torn at a tear stress of at least 20 cN / mm or more, preferably 28 to 300 cN. The method for measuring the tear stress at which the back sheet 3 is torn is as described above.

The absorbent article 1 of the present embodiment will be further described. As shown in FIGS. 1 and 3, the skin contact surface side of the topsheet 2 is a mountain along the longitudinal center line C of the absorbent article 1. Thus, it is folded in half so that the non-skin contact surface side of the back sheet 3 becomes a valley.
More specifically, in the packaged state, the article 1 is folded in two with the surfaces on the non-skin contact surface side of the back sheet 3 being overlapped, or is developed and packaged in a flat shape. Further, when used, the article 1 is folded in two and the non-skin contact surface side opens in a fan shape as shown in FIG. In the present specification, the two-fold includes a state where the non-skin contact surfaces are overlapped and folded into two as described above and a state where the non-skin contact surfaces are opened in a fan shape as shown in FIG.
In addition, the thickness of this article 1 is that of the article 1 in a flat state.

When the absorbent article 1 of this embodiment is worn, as shown in FIG. 5, it is sandwiched between the labia's labia, and the skin contact surface of this article 1 is preferably in close contact with the wall between the labia. Worn. The article 1 is thin and soft and flexibly deforms and abuts according to the shape of the wall portion between the labia. Since this article 1 is used with the ridge portion of the mountain fold on the skin contact surface side being arranged in the back between the labia of the woman, the excreted body fluid moves in the longitudinal direction along the ridge portion. The body fluid is absorbed by the entire article 1. Further, since the ridge portion has a round cross section as shown in FIG. 3 due to the elasticity of the material, it is difficult to cause discomfort and pain when pushed.
When wearing the article 1, a finger is inserted between the non-skin contact surface side surfaces of the back sheet 3 that is folded in the valley, and the article 1 is supported by the finger. It is preferable to wear it by sandwiching it between the labia.
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.

When the absorbent article 1 of this embodiment is removed from the body after use and then discarded in the flush toilet, it is preferable that the vicinity of the division start portion 14 is picked and torn before the disposal. At the notches 23 and 33 in the split start portion 14 of the article 1, the two ends that are divided into two branches are picked, one is pulled toward the skin contact surface side of the article 1, and the other is the non-skin contact surface Each of the top sheet 2 and the back sheet 3 joined at the periphery by applying a tearing stress along the longitudinal direction to the article 1 by pulling it toward the side, or by pulling it outward in the width direction of the article 1 As shown in FIG. 4, it can be easily torn along the longitudinal direction. In this case, the absorber 4 may be partially torn to the left, right, torn approximately symmetrically, or may be exposed to the outside with little torn. For example, when the absorber 4 is joined to the back sheet 3 with an adhesive or the like, it is considered that the absorber 4 is torn with the back sheet 3 in a substantially bilaterally symmetric manner or partially to the left and right. Moreover, when the absorber 4 is not joined to either the back sheet 3 or the top sheet 2, it is considered that the absorber 4 is exposed to the outside with almost no tearing. In FIG. 4, the article 1 is symmetrically divided, and the broken portion is shown in a straight line. However, the top sheet 2 or the back sheet 3 may not be torn symmetrically in this way. In some cases, the broken portion is not linear. Further, in FIG. 4, the present article 1 is completely torn along the longitudinal direction and separated into right and left, but it is sufficient that the article 1 is torn to the extent that at least the absorber 4 is exposed to the outside.
When the present article 1 is torn in this way and is disposed of in a flush toilet with the absorbent 4 having water decomposability exposed to the outside, the absorbent 4 is agitated in the water flow of the flush toilet, Go out of the club. The article 1 after the absorbent body 4 has gone out is formed of the top sheet 2 and the back sheet 3 and is flexible, and there is no possibility of clogging the water distribution pipe, the septic tank or the sewer.

The absorbent article 1 of this embodiment is sandwiched between spaces between female labia and closely contacts the labia wall to prevent leakage of bodily fluids, and when discarded in a flush toilet after use, Alternatively, from the viewpoint of preventing clogging of sewers and the like, the article 1 preferably has a size not exceeding 12 cm in length, 6 cm in width, and 0.4 cm in thickness. The length and the width are the maximum values in the longitudinal direction or the width direction when the article 1 is developed in a planar shape.
The thickness of the absorbent article is measured under a pressure of 2.5 g / cm ² by appropriately adjusting the size of the measurement plate using a thickness gauge manufactured by Peacock.

  In the absorbent article 1 of this embodiment, the material for forming the topsheet 2 is a water-decomposable nonwoven fabric formed by a hydroentanglement method. When the article 1 is discarded in a flush toilet after use, the top sheet 2 preferably has a property of further decomposing to a fiber level size forming the sheet, and at least the sheet 2 It is preferable that the size of each part after the water is decomposed to a size that does not clog filter media such as septic tanks. In the present specification, the water decomposability 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.

In the absorbent article 1 of the present embodiment, the top sheet 2 is a nonwoven fabric that is entangled to the extent that a web is formed and further hydrolyzed by a hydroentanglement method.
As the web forming material, various known materials can be used, but those formed from a thermoplastic fiber, hydrophilic fiber or mixed fiber of the following are preferred, and in particular, rayon alone or rayon. It is preferable from the viewpoint that it is easy to be entangled and essentially hydrophilic and easily absorbable, as a main component, and a mixture of fibers selected from pulp, cotton and various thermoplastic fibers. The fiber length of each fiber is 10 to 120 mm from the viewpoint of promptly water-dissolving 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.
In addition, as the hydrophilic fiber, wood pulp, cellulose fiber, various regenerated cellulose fibers or fibers containing mixed fibers thereof are preferable. Wood pulp includes bleached wood pulp such as softwood bleached kraft pulp (NBKP), softwood sulfite pulp (NBSP), hardwood bleached kraft pulp (LBKP), etc. Chemically cross-linked pulp having Examples of the cellulose fiber include cotton fiber, burlap, cannabis, flax, linna, hemp, leaf fiber (Manila hemp, sisal hemp), kenaf and other annual fiber materials. Examples of the regenerated cellulose fiber include fibers obtained by a viscose method, a copper ammonia method, and an organic solvent method. For example, as described above, rayon fibers formed by the viscose method can be preferably used.
In addition to the hydrophilic and biodegradable fibers described above, it is more preferable to form a web using fibers having biodegradability described later or fibers made of a resin having biodegradability. Examples of the biodegradable web 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 sheet formed by a nonwoven fabric by the hydroentanglement method and the bond is reinforced 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 (by structural changes such as the removal of the metal cross-links of the salt), the bond is broken immediately and the water is dissolved.
When considering the tearability of the top sheet, it is possible to form a sheet that can be easily torn in the longitudinal direction of the article 1 without a perforation like the back sheet by devising the fiber sheet formation in the hydroentanglement method.
In this case, of course, it is not necessary to add an additional perforation. However, in order to evoke the tearing direction, it is preferable to print a mark on a portion that is visible from the use surface side, such as the skin contact surface or the non-skin contact surface of the top sheet 2 or the upper part of the absorber.
A specific method for improving the essential tearability of the topsheet is as follows.
1. As a fiber material, a long fiber rayon having a fiber length of 70 mm or more is mainly used, and a web is formed by a card method or an air current conveyance method. This web is essentially strong in the flow direction and weak in the direction crossing it because the fibers are aligned in the web production direction (flow direction). This flow direction is used in the longitudinal direction of the absorbent article.
2. Devise the water entanglement nozzle and water flow. Usually, a high-pressure water stream is ejected from a plurality of thin nozzles, and one of these nozzles is narrowed or the water stream is weakened. As a result, the entanglement of the surrounding fibers is weakened, so that the central portion is easily torn.
3. Hydroentanglement requires a support to receive the web, and usually various patterns of nets or perforated rolls are used to continuously feed the web. By devising the net or roll pattern, the same effect as changing the water flow nozzle can be obtained. For example, a deep groove is dug apart from the hole at the center (the effect is to keep the web away from the water stream and weaken the entanglement), and the opening pattern at the center is enlarged (a part of the fiber disappears from the center together with the water stream, and the strength On the contrary, it is possible to devise such as not opening the center only (no entanglement because the water flow does not escape).
It is possible to carry out the above three methods and a combination thereof.

  In the absorbent article 1 of the present embodiment, as the absorbent 4 having water decomposability, various known ones can be used, but a water degradable fiber assembly, a hydrolysable paper or a molded web of fluff pulp or rayon can be used. A water-decomposable non-woven fabric is preferred. The absorbent body 4 is preferably formed from hydrophilic fibers from the viewpoint of good absorbency, and from the viewpoint of good softness, the absorbent body 4 is formed from a bulky web made of thermoplastic fibers having a large three-dimensional crimp. It is preferable. From the viewpoint of combining good absorbency and softness, the mass ratio of the hydrophilic fiber to the thermoplastic fiber is preferably 100: 0 to 60:40. These may be a mixed web, or may be formed by laminating independent layers. In addition, the fiber length of each fiber is 6 to 120 mm from the viewpoint of quick water disintegration when the rigidity of the absorbent body 4 is maintained in a wet state when the article 1 is used and is discarded in a flush toilet after use. It is preferable that

As the hydrolytic paper for forming the absorbent body 4, various known ones can be used, which are formed by adding a water-soluble adhesive to a web containing hydrophilic fibers, hydrophobic fibers or mixed fibers of both. Etc. are preferred.
Examples of the hydrophilic fiber and the hydrophobic thermoplastic fiber that form the absorbent body 4 include the same materials as those described above as the material of the topsheet 2.
Further, various known materials can be used as the web material, but it is preferable to use the same material as the material for the hydrolytic paper.
As the water-decomposable non-woven fabric, various known materials can be used, and those formed by the chemical bond method or the hydroentanglement method are preferable. In the chemical bond method, it is preferable to use a water-soluble adhesive.
As the fiber forming the hydrolytic paper, the web or the water-decomposable nonwoven fabric, it is more preferable to use a fiber having biodegradability or a fiber made of a resin having biodegradability, which will be described later, and having hydrophilicity. Examples of the water-degradable paper or water-decomposable nonwoven fabric having biodegradability include those described in Table No. 97/13920.
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, part or all of the absorbent body 4 can be made of cotton-like pulp or rayon cotton.

  Moreover, the back surface sheet 3 in the absorbent article 1 of the present embodiment is a biodegradable resin film. When the article 1 is discarded in a flush toilet after use, the back sheet 3 has a property of further biodegrading and losing its shape.

In the absorbent article 1 of the present embodiment, various known materials can be used as a material for forming a leak-proof resin film having stretchability and biodegradability, and the following are particularly preferable.
Stretchable and biodegradable films are most easily handled by extruding a thermoplastic and biodegradable plastic into a film. Extrude film is formed, immediately after cooling, immediately after cooling, and uniaxially stretched. This is the most efficient film formation method. Preferred materials include, for example, polylactic acid resin, or polyolefin blended with 20 to 60% by mass polylactic acid resin, or polyolefin mixed with 20 to 40% by mass starch, starch, cellulose and / or powder thereof. Etc. are used. Other biodegradable plastics will be described later. Further, as another preferred embodiment of the back sheet 3, a water-soluble film made by melt-extrusion of a polyvinyl alcohol (PVA) resin having a high degree of saponification, PVA, carboxymethylcellulose and / or a salt thereof was selected. Water-soluble films such as films cast from polymers (thin films obtained by dissolving in water and coating and drying), etc. (films that are difficult to dissolve in a small amount of water and dissolve in a large amount of water), etc. Can be preferably used.

As other biodegradable plastics, specifically, 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), polyglycolic acid (PGA), polyhydroxybutyrate (PHB), polycaprolactone (PCL), polycaprolactone and polybutylene. Mixture or copolymer of succinate (PCL / PBS), copolymer of polyhydroxybutyrate and polyhydroxyvalylate (PHB / PHV), mixture or copolymer of polybutylene succinate and polybutylene adipate Resins such as (PBS / PBA), a copolymer of polyethylene terephthalate and polyethylene succinate (PET / PES), and a copolymer of polybutylene terephthalate and polybutylene adipate (PBT / PBA) are preferred.
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 Polysaccharides such as natural resins, 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. Among them, considering stretchability, the most preferable is a resin in which a polylactic acid resin, starch, starch, cellulose or the like is blended with polyolefin.
In addition, by blending the above resin with a highly environmentally compatible inorganic powder such as calcium carbonate, barium sulfate, talc, and activated carbon (on the other hand, incompatible with the resin) and stretching it into a film, it can be stretched at a relatively low stretch ratio. A film having a predetermined effect (high tearability) is obtained. In this case, the blended amount of the inorganic powder is 30 to 70%, preferably 40 to 60%, based on the total amount of the biodegradable plastic as a base. Since this film has fine pores formed by peeling at the interface between the powder and the resin and has moisture permeability, it is advantageous in terms of feeling of use (hardness).

  As a film forming method for forming a biodegradable resin film, a conventional 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 is used. be able to. The film thus formed is then stretched in one direction and then heat-set.

The stretched biodegradable film has a thickness of preferably 12 to 60 μm, and more preferably 18 to 35 μm, from the viewpoint of film strength and film handleability and ease of biodegradability. . As described above, in order to reinforce the strength of the film, it is also possible to form a leak-proof and biodegradable composite sheet by combining with a water-degradable nonwoven fabric, and the preferred thickness of the film at this time is 10 to 45 μm, It is 12-30 micrometers especially, and the preferable basic weight of a water-decomposable nonwoven fabric is 25-45 g / m < ² >, Especially 30-40 g / m < ² >.

  The biodegradable resin film described above is preferably 30% or more in terms of biodegradability (aerobic ultimate biodegradation: JIS K 6950 or 6953) from the viewpoint of decomposing in a practical period. More preferably, it is more preferably 60% or more.

In the absorbent article 1 of the present embodiment, as the adhesive, those conventionally used for absorbent articles can be used without particular limitation. However, the use of a water-soluble adhesive is particularly useful for the article 1. When it is discarded in the flush toilet, it is preferable from the viewpoint of quickly separating the top sheet 2 and the back sheet 3. It is also preferable to use a biodegradable adhesive.
As the water-soluble adhesive, various known ones are used. 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, galacto Mannan, gelatin, casein, albumin, pull plan, polyethylene oxide, viscose, polyvinyl ethyl ether, sodium polyacrylate, sodium polymethacrylate, polyacrylamide, hydroxylated derivatives of polyacrylic acid, polyvinylpyrrolidone / vinylpyrrolidone vinyl acetate Polymers 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 the monomer copolymerizable with these include esters of these unsaturated carboxylic acids, vinyl acetate, ethylene, acrylamide, vinyl ether and the like. 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.

Similarly, an adhesive that is preferably used may be an adhesive that is not water-soluble but has low tack when wet.
For example, styrene-isoprene-styrene block copolymer (SIS), styrene-butadiene-styrene block copolymer (SBS), styrene-ethylene-butylene-ethylene copolymer (SEBS), etc. as the main component (base polymer) Of adhesives containing hydrogenated petroleum resin as tackifier and paraffin oil or paraffin wax as plasticizer, plasticizer component is low / tackifier is hard, hard, and gains adhesive strength with surface tack The adhesive type is preferably used for this purpose. As an example, an adhesive having 50% by mass of SEBS, 18% by mass of a plasticizer, and 32% by mass of a tackifier is raised. When this adhesive is applied by spiral spraying or slot spraying (because it is hard), it does not easily penetrate into the material and has a weak engagement effect. However, it has a strong surface tack (so-called stickiness), so it has strong adhesion when dried. Is expressed. 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.

  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, if discarded in a large amount of water, the insolubilized adhesive will be dissolved in water again. 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, it is preferable to use a polyvalent metal ion as the cross-linking 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. Further, when polyvinyl alcohol is used for the adhesive as described above, the same appropriate insolubilization can be achieved by the salting out effect by blending a small amount of carboxylate.

According to the absorbent article 1 of this embodiment described above, the top sheet 2 and the absorbent body 4 have water decomposability, and the back sheet 3 has biodegradability. It is continuously decomposed by being stirred by.
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.

  Next, the absorbent article 1 of 2nd and 3rd embodiment of this invention is demonstrated. As for the second and third embodiments, the description in detail regarding the first embodiment is appropriately applied to points that are not particularly described.

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 for forming the liquid-permeable surface sheet 2 having biodegradability, but biodegradable films, biodegradable paper, Degradable webs or biodegradable nonwoven fabrics are preferred. These sheet materials are also preferably provided with a plurality of holes so that the body fluid can pass therethrough.
Examples of the material for forming the biodegradable film include the same materials as those for the back sheet of the first embodiment. When the topsheet 2 is formed of a film stretched in the longitudinal direction, the perforation 22 may not be provided.
As the material of the biodegradable paper, biodegradable web or biodegradable nonwoven fabric, various known materials can be used, but the water-decomposable nonwoven fabric or water-degradable paper forming material described in the first embodiment is preferable. . Others are the same as in the first embodiment.

  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. Others are the same as in the first embodiment.
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 a material for forming the biodegradable absorbent body 4, but biodegradable paper, biodegradable web, or biodegradable nonwoven fabric can be used. Etc. are 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 the hydrophilic biodegradable fiber include those having the hydrophilic property among the above-described biodegradable fibers. Specifically, the cotton fiber (cotton), the material of the hydrolytic paper of the first embodiment. Various fibers described as hydrophilic fibers 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 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.

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, in the absorbent article of the present invention, a plurality of division start portions may be provided. In this case, it is preferable that a plurality of perforations are also provided and extend from each of the division start portions as a starting point.
Moreover, it is also preferable to provide a fixing adhesive part for fixing to the underwear or the like on the non-skin contact surface side of the back sheet. In particular, when used in combination with a conventional absorbent article or the like that is fixed to the inside of the underwear, the absorbent article of the present invention is a skin contact of the absorbent article that is fixed to the underwear via the adhesive portion during the wearing. Fixed to the contact surface. 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. In this case, it is preferable that the material for forming the adhesive portion has water decomposability and / or biodegradability.
In addition, it is also preferable to provide a shape-retaining sheet that is stretched between both side portions in the longitudinal direction of the non-skin contact surface from the viewpoint of maintaining the folded form of the article. In this case, it is preferable that the material for forming the shape retaining sheet has water decomposability and / or biodegradability.
Further, the non-skin contact surface side surfaces of the back sheet are partially bonded with a water-soluble or biodegradable adhesive at one end portion in the longitudinal direction or the like. This is preferable from the viewpoint of maintaining the folded form and the part that restricts the insertion of the fingertip when worn.

Moreover, in each embodiment, although the division | segmentation start part was provided in each of the surface sheet and the back surface sheet, it should just be provided in any one. In this case, it is preferable that the division start portion is formed from one of the top sheet and the back sheet having the division start portion.
Further, in each embodiment, the perforation is provided over the entire length of the article, but it is sufficient that the perforation extends over 50% or more of the length of the article.
Moreover, in each embodiment, although the division | segmentation start part was provided in one edge part of the longitudinal direction of this article, you may be provided in both edge parts. Moreover, you may provide in the edge part of the width direction. In this case, it is preferable that the perforation is provided over 50% or more of the width of the article along the width direction of the topsheet, starting from the division start portion.
Moreover, it is good also as a system which replaces with the decomposition | disassembly system by a notch and a dividing line, and peels between a surface sheet and a back surface sheet, and decomposes | disassembles. That is, even in a system in which the top sheet and part of the back sheet are peeled off at the tip of the knob part, each is picked, and the outer peripheral seal part is peeled and disassembled (stripping the top sheet and the back sheet). Good.

Further, in each embodiment, the back sheet was formed from a stretched biodegradable film, but if the back sheet is not provided with a split start portion, it is sufficient if it has leakproofness, It is also preferable to use a biodegradable film or a biodegradable paper that does not have stretchability, a biodegradable nonwoven fabric, a water-degradable paper, or a water-degradable nonwoven fabric coated with wax.
Moreover, although the surface sheet in 1st Embodiment was a water-decomposable nonwoven fabric, it is also preferable that it is a water-decomposable paper or web.
Moreover, although the topsheet in 1st Embodiment was provided with the perforation, when the topsheet is formed from the nonwoven fabric by a hydroentanglement method, it does not need to provide the perforation. In this case, it is preferable to produce the topsheet so that the arrangement direction of the nonwoven fabric fibers forming the topsheet matches the longitudinal direction of the topsheet. Since the topsheet having such a configuration has a weak tear strength in the width direction, the topsheet can be easily torn if a notch that is a split start portion is provided at one end in the longitudinal direction. .
The absorbent article of the present invention may be an interlabial pad, but may also be a sanitary napkin or an incontinence pad that is used while being fixed inside an undergarment.
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.

FIG. 1 is a perspective view showing a first embodiment of an absorbent article of the present invention. FIG. 2 is a plan view of the absorbent article according to the first embodiment. 3 is a cross-sectional view taken along the line XX of FIG. Drawing 4 is a top view showing typically the state where the absorptive article of a 1st embodiment was torn. 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.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Absorbent article 12 Knob part 14 Division start part 2 Top sheet 22 Perforation 23 Notch 3 Back sheet 33 Notch 4 Absorber C Vertical center line

Claims (4)

It comprises a top sheet, a back sheet and an absorbent body interposed between both sheets, and is a substantially vertically long absorbent article,
Each of the top sheet, the back sheet and the absorber has water decomposability and / or biodegradability,
A split start part that can be a trigger for tearing in the peripheral part of the absorbent article, and a perforation extending in the longitudinal direction starting from the split start part in the top sheet, and starting from the split start part, The absorbent article is tearable so that the absorber is exposed ;
Along the longitudinal center line of the absorbent article, the top sheet is folded in two so that the skin contact surface side of the top sheet is a mountain and the non-skin contact surface side of the back sheet is a valley, and sandwiched between labia Used
The division start portion is provided at an end portion in the longitudinal direction of the absorbent article, and the perforation is provided on the longitudinal center line over a length of 50% or more in the longitudinal direction of the absorbent article. absorbent article it is.   The absorbent article according to claim 1, wherein the division start part is a notch or a cut formed in a peripheral part of the absorbent article.   3. The tear stress of the top sheet when the two notches or tears are torn and teared at both ends is 28 cN or more, and the tear stress of the back sheet when tearing is 20 cN or more. Absorbent article as described in 1. Before SL backsheet is formed of a resin film stretched at least twice in one direction, according to any one of claim 1 to 3, wherein the one direction is coincident with the longitudinal direction of the backsheet Absorbent articles.

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