JP2007202596A - Body fluid absorbing element and body fluid absorbable article - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a body fluid absorbent article such as a disposable paper diaper, a sanitary napkin, a urine absorbing pad, an absorbing pad and a body fluid absorbing element excellent in absorbency which can be used in the body fluid absorbent article. <P>SOLUTION: The body fluid absorbing element 3 is constituted of a body fluid absorber 4 and a cover sheet 5 of the body fluid absorber 4. Further, the cover sheet 5 has a cover sheet 5a in the front face side of the body fluid absorber 4 and a covering sheet 5b in the back face side of the same respectively, the body fluid absorbing element 3 is constituted by connecting the cover sheets 5a, 5b in the outside of the periphery of the body fluid absorber 4 and folding back the connected portion outward and connecting the same to the back face of the back face side cover sheet 5b if needed. In this case, the front face side cover sheet 5a and the back face side cover sheet 5b are formed of a nonwoven cloth and a tissue respectively. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a bodily fluid absorbent article such as a disposable paper diaper, a sanitary napkin, a urine pad, an absorbent pad, and a bodily fluid absorbing element that can be used for the bodily fluid absorbent article.

As this type of bodily fluid absorbing element, there is conventionally a bodily fluid absorbing element 100 as shown in FIG. The body fluid absorbing element 100 mainly includes a body fluid absorber 101 and a covering sheet 102 of the body fluid absorber 101. The body fluid absorber 101 is formed by mixing a granular absorbent polymer in a fiber assembly such as a fluffy pulp fiber assembly or a fiber assembly made of tow. On the other hand, the covering sheet 102 is made of crepe paper or the like, and is wound around the surface, one side surface, the back surface, the other side surface, and the surface of the body fluid absorbent body 101 in this order (so-called frame winding). (For example, refer to Patent Document 1). The forehead winding of the covering sheet 102 is performed such that an overlap portion 103 (a portion where one end portion and the other end portion of the covering sheet 102 overlap) is formed on the surface of the body fluid absorber 101. This is because the portion of the body fluid absorbent body 101 that is not covered by the coating sheet 102 is eliminated, and thus, for example, the shape retention of the body fluid absorbent body 101 is improved. The conventional bodily fluid absorbing element 100 thus configured is commercially available as a bodily fluid absorbent article such as a paper diaper or a sanitary napkin, for example, by providing a surface side article sheet such as a top sheet or a second sheet on the surface side. It has become.
However, in this conventional body fluid absorbing element 100, the covering sheet 102 has the overlap portion 103, so that the body fluid may stagnate in the overlap portion 103. When the body fluid stagnates, for example, the absorption rate is lowered, the body fluid is reversed, the feeling of wiping is reduced, and the absorption performance is lowered.
JP 2001-161748 A

  A main problem to be solved by the present invention is to provide a body fluid absorbing element and a body fluid absorbent article having excellent absorption performance.

The present invention that has solved this problem is as follows.
[Invention of Claim 1]
A body fluid absorbing element comprising a body fluid absorber and a covering sheet of the body fluid absorber,
In the covering sheet, the covering sheet provided on the front surface side of the body fluid absorber and the covering sheet provided on the back surface side are joined at the outer periphery of the body fluid absorber, or joined at the outer periphery of the body fluid absorber. This joined portion is folded outward and joined to the back side of the back side covering sheet,
The body fluid-absorbing element, wherein the surface-side covering sheet is formed of a nonwoven fabric and the back-side covering sheet is formed of tissue paper.

[Invention of Claim 2]
The body fluid-absorbing element according to claim 1, wherein the nonwoven fabric is formed of fibers having a diameter of 0.02 dtex or more.

[Invention of Claim 3]
The bodily fluid absorbing element according to claim 1 or 2, wherein the bodily fluid absorbent includes an absorbent polymer, and the nonwoven fabric has an interfiber distance of 50 µm or more and less than 850 µm.

[Invention of Claim 4]
A bodily fluid absorbent article comprising a bodily fluid absorbent body and a bodily fluid absorbing element comprising a covering sheet of the bodily fluid absorbent body, and at least one article sheet provided on the surface side of the bodily fluid absorbent element,
The covering sheet is formed by joining the covering sheet provided on the front surface side of the body fluid absorber and the covering sheet provided on the back surface side, on the outer periphery of the body fluid absorber,
The body surface absorbent sheet according to claim 1, wherein the surface side covering sheet has a flat surface and a raised surface on the back surface.

[Invention of Claim 5]
The bodily fluid absorbent article according to claim 4, wherein the covering sheet includes only the front surface side covering sheet, not the back surface side covering sheet, and a waterproof sheet is provided on the back surface side of the body fluid absorbing element.

  According to the present invention, it becomes a bodily fluid absorption element and a bodily fluid absorptive article excellent in absorption performance.

  Next, an embodiment of the present invention will be described. In the following, a case where the body fluid absorbent article is a “fixing tape-type paper diaper” will be described as an example.

[Shape of paper diapers, etc.]
As shown in FIGS. 2 and 3, the disposable diaper 10 according to the present embodiment includes a front-side article sheet composed of a body fluid-permeable top sheet 1 and a second sheet 6, and a back-side side composed of a body fluid-impermeable waterproof sheet 2. It consists mainly of an article sheet and a body fluid absorbing element 3 interposed between the top sheet 1 and the waterproof sheet 2.

  The top sheet 1 and the waterproof sheet 2 have the same shape as the planar outer shape of the disposable diaper 10, and the front and rear end portions and both side portions extend forward and rearward or laterally from the front and rear end edges or both side edges of the body fluid absorbing element 3. ing. The lateral extension of the top sheet 1 and the waterproof sheet 2 is particularly long at the front and rear ends. For example, a fastening material such as a fastening tape (not shown) can be attached to the long extending portion (hereinafter also simply referred to as “extending portion”).

  Moreover, the top sheet 1 and the waterproof sheet 2 are joined at the extending portion. The bonding method is not particularly limited. For example, hot melt bonding, ultrasonic sealing, heat sealing (thermal fusion), heat pressing (thermocompression bonding), or a combination thereof can be used. FIG. 3 shows a form bonded by hot melt H2.

  On the other hand, the body fluid absorbing element 3 mainly includes a body fluid absorber 4 and a covering sheet 5 that covers the body fluid absorber 4. As shown in FIG. 2, the body fluid absorbing element 3 has a substantially hourglass shape with a narrow central portion in the front-rear direction. The body fluid absorber 4 is held in shape by the covering sheet 5.

  The covering sheet 5 is formed by joining the covering sheet 5a provided on the front surface side of the body fluid absorber 4 and the covering sheet 5b provided on the back surface side on the outer periphery of the body fluid absorber 4 (hereinafter this joined). The part is also simply referred to as “joining part”), or joined at the outer periphery of the periphery, and the joined part is folded outward and joined to the back surface of the back-side coating sheet 5b. According to this form, the surface side of the body fluid absorber 4 is constituted by the surface side covering sheet 5a and becomes flat (planar), and the overlap portion 103 (see FIG. 1) is not formed (does not exist). There is no possibility that the absorption performance is lowered. Moreover, the surface side coating sheet 5a and the back surface side coating sheet 5b may be laminated, hydrophilized (usually, for the surface side coating sheet 5a), hydrophobized / water-repellent, as required. It can be processed (normally about the back surface side coating sheet 5b).

  The joining method in the outer periphery of the body fluid absorber 4 of the front surface side covering sheet 5a and the back surface side covering sheet 5b is not particularly limited. It can be the same as the joining in the extension part of the top sheet 1 and the waterproof sheet 2. FIG. 3 shows a form bonded by hot melt H1.

  In addition, this joining is performed from the inner edge of the joint portion so that the distance between the peripheral edge of the body fluid absorber 4 and the inner edge of the joint portion is any distance (that is, how far away from the peripheral edge of the body fluid absorber 4). The distance to the outer edge (that is, over which range) is not particularly limited. However, it is preferable to join so that the peripheral edge of the body fluid absorber 4 and the inner edge of the joined portion are as short as possible, more preferably joined so as to be 10 mm or less, and joined so as to be 5 mm or less. It is particularly preferable to do this. If it joins so that it may become as short distance as possible, the shift | offset | difference, a twist, a crack, etc. of the bodily fluid absorber 4 are prevented, and shape retainability improves. In addition, from the viewpoint of shape retention, there is no particular limitation on the distance at which the joining portion is joined from the inner edge to the outer edge. The distance from the inner edge to the outer edge of the bonding portion can be set as appropriate from the viewpoint of, for example, bonding strength.

  In this embodiment, it is preferable to form the front surface side covering sheet 5a with a nonwoven fabric and the back surface side covering sheet 5b with tissue paper, respectively. When the covering sheet 5a on the surface side, which is the skin surface side, is formed of a nonwoven fabric, mechanical processing such as embossing and pressing can be performed, and surface properties, absorbability, and flexibility can be improved. Moreover, when the surface side coating sheet 5a is formed with a nonwoven fabric, there is also an advantage that it is difficult to tear. On the other hand, when the back surface side covering sheet 5b is formed of tissue paper, the above advantages of improved surface properties and resistance to tearing are realized at low cost.

  The nonwoven fabric of the surface-side coating sheet 5a is preferably formed of fibers having a diameter of 0.02 to 2.0 dtex, more preferably formed of fibers having a diameter of 0.05 to 0.5 dtex. preferable. When the non-woven fabric is formed of fibers having a diameter of 0.02 dtex or more, the surface-side covering sheet 5a is rich in bulk, density, stiffness, absorption polymer removal prevention, raising, elasticity, flexibility, and the like.

  Here, when the body fluid absorber 4 includes an absorbent polymer, specifically, for example, when the absorbent polymer is mixed into the fiber assembly, the interfiber distance of the nonwoven fabric is 50 μm. As described above, it is preferably less than 850 μm, more preferably 50 μm or more and less than 500 μm, further preferably 50 μm or more and less than 180 μm, and more preferably 50 μm or more and 90 μm. Particularly preferred. When the distance between the fibers is shortened, the absorbent polymer is prevented from coming off.

  Moreover, as for the surface side coating sheet 5a, as expanded and shown in FIG. 3, it is preferable that the surface 5a1 is made into a flat (flat) surface, and the back surface 5a2 is made into the raising surface (fluffed surface). When the surface 5a1 is a flat surface, the adhesion between the article sheet provided on the surface side of the body fluid absorbing element 3 and the second sheet 6 in this embodiment is improved, and the article sheet and the body fluid absorbing element 3 are improved. Misalignment is prevented. On the other hand, when the back surface 5a2 is a raised surface, this raised hair becomes a body fluid passage from the surface side covering sheet 5a to the body fluid absorber 4, and the absorption performance is improved.

  Furthermore, the covering sheet 5 may be provided with the waterproof sheet 2 or the like directly or indirectly on the back side of the body fluid absorbing element 3 without the back side covering sheet 5b only by the front side covering sheet 5a. If there is no back side covering sheet 5b, the material source is reduced, and the soft feeling when gripping the product (article) is improved (that is, the rough feeling peculiar to tissue paper is lost).

(Other)
(1) In this embodiment, the article sheet on the front side is a two-layer structure in which the top sheet 1 and the second sheet 6 are laminated. However, the purpose is not limited to two layers. For example, it can be set as one layer which consists only of the top sheet 1, or it can also be set as the 3 layer, the 4 layer, the 5 layer, or more layers by which the other sheet | seat was laminated | stacked suitably. That is, it is sufficient that at least one article sheet is provided. In addition, the form which has the second sheet | seat 6 like this form is excellent in the diffusibility of a bodily fluid.
(2) The back surface side covering sheet 5 b can be joined to the waterproof sheet 2. By this joining, deviation between the back side article sheet (waterproof sheet 2) and the body fluid absorbing element 3 is prevented. In addition, this joining can be performed by the method similar to the joining in the extension part.
(3) The paper diaper 10 may be provided with known leakage prevention means such as a three-dimensional gather and a three-dimensional cuff.
(4) In this embodiment, the fiber assembly constituting the body fluid absorber 4 is preferably a fiber assembly made of tow. Since the fiber assembly made of tow has a large void volume, the body fluid holding ability of the body fluid absorber 4 is improved.
(5) In this specification, for example, “consisting of” A and B does not mean “consisting solely of” A and B. That is, the form which does not contain the form containing other than A and B is also included.

[Material of each component]
(Fiber assembly made of tow)
The fiber assembly made of tow means a fiber assembly made of tows (fiber bundles) composed of fibers, that is, manufactured using tow as a raw material. Examples of tow fibers include polysaccharides or derivatives thereof (cellulose, cellulose ester, chitin, chitosan, etc.), synthetic polymers (polyethylene, polypropylene, polyamide, polyester, polylactamamide, polyvinyl acetate, etc.). In particular, cellulose esters and cellulose are preferable.

  As cellulose, cellulose derived from plants such as cotton, linter, and wood pulp, bacterial cellulose, and the like can be used. Regenerated cellulose such as rayon may be used, and the regenerated cellulose may be a spun fiber. The shape and size of cellulose is a continuous fiber that can be regarded as a substantially infinite length and has a long diameter of several millimeters to several centimeters (for example, 1 mm to 5 cm), and a particle diameter of about several microns (for example, 1 to 100 μm). Can be selected from various sizes up to a fine powder. Cellulose may be fibrillated, such as beaten pulp.

  Examples of the cellulose ester include organic acid esters such as cellulose acetate, cellulose butyrate, and cellulose propionate; mixed acid esters such as cellulose acetate propionate, cellulose acetate butyrate, cellulose acetate phthalate, and cellulose nitrate acetate; polycaprolactone graft Cellulose ester derivatives such as hydrogenated cellulose ester can be used. These cellulose esters can be used alone or in admixture of two or more. The viscosity average degree of polymerization of the cellulose ester is, for example, 50 to 900, preferably 200 to 800. The average substitution degree of the cellulose ester is, for example, about 1.5 to 3.0, preferably about 2 to 3.

  The average degree of polymerization of the cellulose ester can be, for example, 10 to 1000, preferably 50 to 900, more preferably 200 to 800, and the average degree of substitution of the cellulose ester is, for example, 1 to 3, preferably 1 to 2. 15, more preferably 1.1 to 2.0. The average degree of substitution of the cellulose ester can be selected from the viewpoint of enhancing biodegradability.

  As the cellulose ester, an organic acid ester (for example, an ester with an organic acid having about 2 to 4 carbon atoms), particularly cellulose acetate is suitable. Cellulose acetate can easily adjust the density.

  In addition, the acetylation degree of cellulose acetate is often about 43 to 62%, but particularly 30 to 50% is preferable because it is excellent in biodegradability.

  The tow constituent fiber may contain various additives such as a heat stabilizer, a colorant, an oil agent, a yield improver, a whiteness improver, and the like. Of these, the oil agent is effective for skin care that also serves as a water repellency, and may be applied to the tow constituent fibers.

  The fineness of the tow constituent fibers can be, for example, 1 to 16 denier, preferably 1 to 10 denier, more preferably 2 to 8 denier. The tow constituent fiber may be a non-crimped fiber, but is preferably a crimped fiber. The crimped degree of the crimped fibers can be, for example, 5 to 75, preferably 10 to 50, more preferably 15 to 50 per inch (2.54 cm). Further, a crimped fiber that is uniformly crimped is often used. When crimped fibers are used, a bulky and lightweight fiber assembly can be produced, and a highly integrated tow can be easily produced by entanglement between fibers. The cross-sectional shape of the tow constituting fiber is not particularly limited, and may be any one of, for example, a circular shape, an oval shape, an irregular shape (for example, a Y shape, an X shape, an I shape, an R shape) or a hollow shape. Also good. The tow constituting fiber is used in the form of a tow (fiber bundle) formed by bundling, for example, 3,000 to 1,000,000, preferably 5,000 to 1,000,000 single fibers. Can do. The fiber bundle is preferably formed by bundling 3,000 to 1,000,000 continuous fibers.

  Tow is excellent in air permeability due to weak entanglement between fibers, but may sag. Therefore, for the purpose of preventing sagging and maintaining a wide gap, it is preferable to use a binder having an action of bonding or fusing the contact portion of the fiber.

  Examples of binders include ester plasticizers such as triacetin, triethylene glycol diacetate, triethylene glycol dipropionate, dibutyl phthalate, dimethoxyethyl phthalate, and triethyl citrate, as well as various resin adhesives, especially thermoplastic resins. Can be used.

  The thermoplastic resin is a resin that exhibits an adhesive force when melted and solidified, and includes a water-insoluble or hardly water-soluble resin and a water-soluble resin. A water-insoluble or poorly water-soluble resin and a water-soluble resin can be used together as necessary.

  Examples of water-insoluble or hardly water-soluble resins include olefinic homo- or copolymers such as polyethylene, polypropylene, ethylene-propylene copolymer, ethylene-vinyl acetate copolymer, polyvinyl acetate, polymethyl methacrylate, methacryl Acid methyl-acrylic acid ester copolymer, acrylic resin such as copolymer of (meth) acrylic monomer and styrene monomer, polyvinyl chloride, vinyl acetate-vinyl chloride copolymer, polystyrene, styrene monomer ( Styrenic polymers such as copolymers with (meth) acrylic monomers, optionally modified polyesters, nylon 11, nylon 12, nylon 610, nylon 612 and other polyamides, rosin derivatives (eg, rosin esters), Hydrocarbon resin (for example, terpene resin Dicyclopentadiene resin, petroleum resin), and hydrogenated hydrocarbon resins. One or two or more of these thermoplastic resins can be used.

  Examples of water-soluble resins include various water-soluble polymers such as polyvinyl alcohol, polyvinyl pyrrolidone, polyvinyl ether, vinyl monomers, and copolymerizable monomers having a carboxyl group, a sulfonic acid group, or a salt thereof. Vinyl water-soluble resins such as copolymers, acrylic water-soluble resins, polyalkylene oxides, water-soluble polyesters, water-soluble polyamides, and the like can be used. These water-soluble resins can be used alone or in combination of two or more.

  Various additives such as stabilizers such as antioxidants and ultraviolet absorbers, fillers, plasticizers, preservatives, and antifungal agents may be added to the thermoplastic resin.

  The fiber assembly can be produced by a known method using tow as a raw material, and at that time, it can be opened in a strip shape so as to have a desired size and bulk as necessary. The opening width of the tow is arbitrary, and can be, for example, a width of 100 to 2000 mm, preferably 150 to 1500 mm. The fiber density of the absorbent body can be adjusted by adjusting the degree of tow opening.

  Tow opening methods include, for example, a method in which tow is spread over a plurality of opening rolls, and the tow width is gradually expanded as the tow progresses, and tow tension (elongation) and relaxation (contraction) And the like, and a method of widening and opening using compressed air can be used.

  FIG. 4 is a schematic diagram illustrating an example of the opening facility. In this example, the tow 71 serving as a raw fabric is sequentially fed out, and in the conveying process, a widening means 77 using compressed air and a plurality of spread nip rolls 73, 74, 75 whose peripheral speed is faster as the downstream side roll is combined. After passing through the opened portion and widened / opened, it is passed through a binder addition box 76, and a binder is added (for example, the box 76 is filled with mist of triacetin), and the tow having a desired width and density is formed. A fiber assembly 33 is formed.

(Surface-side article sheet (top sheet 1 and second sheet 6))
In this embodiment, the surface-side article sheet has a property of transmitting body fluid. Therefore, the material of the surface-side article sheet is sufficient if it exhibits this body fluid permeability, and examples thereof include a porous or non-porous nonwoven fabric and a porous plastic sheet. Of these, the nonwoven fabric is not particularly limited as to what the raw fiber is. Examples include synthetic fibers such as polyethylene and polypropylene such as olefins, polyesters and polyamides, recycled fibers such as rayon and cupra, natural fibers such as cotton, and mixed fibers in which two or more of these are used. can do. Furthermore, the nonwoven fabric may be manufactured by any processing. Examples of the processing method include known methods such as a spunlace method, a spunbond method, a thermal bond method, a melt blown method, and a needle punch method. For example, the spun lace method is a preferable processing method when the flexibility and drape properties are required, and the thermal bond method is the preferable processing method when the bulkiness and softness are required.

  Further, the front-side article sheet may be composed of one sheet or two or more sheets in the plane direction.

(Body fluid absorber 4)
The body fluid absorber 4 has a property of holding the absorbed body fluid, and can be formed, for example, by mixing an absorbent polymer into the fiber assembly. The material of the fiber assembly is not particularly limited. For example, known materials such as cotton-like pulp and synthetic pulp can be exemplified. Moreover, the raw material fiber of a pulp is not specifically limited, For example, the cellulose fiber obtained from woods, such as a mechanical pulp, a chemical pulp, and a dissolving pulp, Artificial cellulose fibers, such as rayon and an acetate, etc. can be illustrated. However, the wood used as the raw material for cellulose fibers is more preferable in terms of function and price because conifers have longer fiber lengths than hardwoods.

Furthermore, the fiber assembly can be formed of a fiber assembly made of the above-described tow. Hereinafter, this case will be described in detail.
FIG. 5 shows an example of a manufacturing facility for the body fluid absorbing element 3, and a continuous belt-like fiber assembly 33 made of tows having a desired width and density is supplied. For this reason, this continuous body liquid absorption element manufacturing line is directly connected with the above-mentioned fiber assembly manufacturing line, and the manufactured fiber assembly 33 can be directly sent to the main body liquid absorption element manufacturing line.

  The supplied fiber assembly 33 is defibrated with compressed air in a defibrating box 89 and then fed into a suction drum 88. The suction drum 88 has an intake hole on the outer peripheral wall, and is configured to be sucked by a suction pump (not shown) from the inside over a predetermined range in the circumferential direction (a range substantially in the left half in the illustrated example). The fiber assembly 33 is guided by the suction drum 88 while being in contact with the outer peripheral surface. In this process, suction is performed from the suction hole of the suction drum 88, so that the fiber aggregate 33 and the bottom sheet 7 defibrated in a cotton shape are bonded and transported to the next process.

  In a particularly preferred form, the fiber assembly 33 is defibrated (here, defibration means a state in which the fiber assembly 33 is made into a cotton shape with compressed air, and the above-described opening means that the fiber assembly 33 is desired. (It is different in that it is widened (widened)), and then the bottom sheet 7 is further covered thereon. In this case, in the suction drum 88, suction is performed from the side surface opposite to the surface of the fiber assembly 33 that covers the bottom sheet 7. Thus, when the bottom sheet 7 is covered prior to suction, a stronger suction force acts than in the case where nothing is covered, and adhesion between the fiber assembly 33 and the bottom sheet 7 is improved. Make it stronger and more uniform.

  The back surface side covering sheet 5 b is covered on the back surface side of the fiber assembly 33 and the bottom sheet 7 guided by the suction drum 88. Thereafter, the absorbent polymer 35 is passed through an absorbent polymer supply device 87 including a spray box and a rotating drum.

  Thus, the fiber assembly 33 (that is, the body fluid absorber 4) to which the absorbent polymer 35 has been applied (mixed) is separately covered with, for example, a front surface side coating sheet 5a, and the front surface side coating sheet 5a and the back surface side coating sheet 5b. Is joined outside the peripheral edge of the body fluid absorber 4, and if necessary, the joined portion is folded outward and joined to the back surface of the back surface side covering sheet 5 b and then cut to a predetermined length. The individual body fluid absorbing element 3 is used.

  In the above manufacturing process, the adhesive can be applied to the fiber assembly 33, the back-side coating sheet 5b, the bottom sheet 7, and the like by the adhesive application devices 84, 85, and 86. The adhesive application device 84 is used for bonding the back surface side coating sheet 5 b and the bottom sheet 7, and the adhesive application device 85 is used for bonding the bottom sheet 7 and the fiber assembly 33. Is provided for adhesion between the fiber assembly 33 and the absorbent polymer 35 (for polymer fixation). Any one or a combination of two or more of these adhesives can be applied (applied). As the adhesive, an adhesive made of a thermoplastic resin (specific examples are as described above) can be suitably used.

  The quantitative arrangement and density distribution of the absorbent polymer 35 with respect to the fiber assembly 33 are preferably uniform for the purpose of general purpose, but the purpose is to exhibit special absorption characteristics. It is also preferable to bias in accordance with the above.

  Specifically, in the case of applying to the illustrated form, in the absorbent polymer supply device 87, the spray amount can be biased in the plane direction. Further, by biasing the suction force in the suction drum 88, a higher amount of the absorbent polymer 35 is located on the suction drum 88 side as the suction force is higher. Therefore, the density of the absorbent polymer 35 is reduced. Can be biased. For example, the density of the absorbent polymer 35 at the center in the width direction of the fiber assembly 33 can be increased by making the suction force at the center in the width direction of the suction drum 88 higher than the sides (or by increasing the suction time). Can be higher than the sides.

  Furthermore, when the fiber assembly 33 is a fiber assembly made of tow, the liquid easily flows along the continuous direction of the fibers. Therefore, special absorption characteristics can be imparted by biasing the density of the fibers. it can. For this reason, as a method of biasing the fiber density, it can be achieved by performing unbalanced fiber opening at the time of manufacturing the fiber assembly 33 or by partially using a plurality of tows. For example, if the fiber density at the center portion in the width direction of the fiber assembly 33 is biased so as to be higher than both side portions, the diffusion speed of the body fluid becomes higher at the center portion in the width direction of the fiber assembly 33.

(Waterproof sheet 2)
In this embodiment, the waterproof sheet 2 has a property of not transmitting body fluid. Therefore, the material of the waterproof sheet 2 is sufficient as long as it exhibits this body fluid impermeability, for example, an olefin resin such as polyethylene or polypropylene, a laminated nonwoven fabric in which a nonwoven fabric is laminated on a polyethylene sheet, or a waterproof film is interposed. Thus, a non-woven fabric that is substantially impervious to liquid (in this case, the waterproof film and the non-woven fabric constitute the body fluid-impermeable waterproof sheet 2), and the like. Of course, in addition to this, materials having liquid impermeability and moisture permeability, which have been used and used in recent years from the viewpoint of preventing stuffiness, can also be exemplified. As the sheet of the material having liquid impermeability and moisture permeability, for example, an inorganic filler is kneaded in an olefin resin such as polyethylene or polypropylene, and the sheet is formed, and then stretched in a uniaxial or biaxial direction. Examples of the microporous sheet obtained in this way can be given.

(Coating sheet 5)
In this embodiment, the material of the covering sheet 5 is not particularly limited. Specifically, for example, a body fluid permeable sheet such as crepe paper, tissue paper, non-woven fabric, or a perforated sheet can be used. However, as described above, it is preferable that the front surface side cover sheet 5a is formed of a nonwoven fabric and the back surface side cover sheet 5b is formed of tissue paper.

(Absorbent polymer 35)
As the absorptive polymer 35, a polymer that absorbs and retains bodily fluids, for example, ten times or more of its own weight can be used. Examples of this include starch-based, cellulose-based and synthetic polymer-based materials, such as starch-acrylic acid (salt) graft copolymer, saponified starch-acrylonitrile copolymer, sodium carboxymethylcellulose cross-linked product and acrylic. An acid (salt) polymer or the like can be used. The shape of the absorbent polymer 35 is preferably a granular material that is usually used, but other shapes can also be used.

  INDUSTRIAL APPLICABILITY The present invention can be applied as a body fluid absorbent article such as a fastening tape type paper diaper or a pants type paper diaper, a sanitary napkin, an absorbent pad, a urine collection pad, and a body fluid absorbent element of the body fluid absorbent article.

It is a cross-sectional schematic diagram of a conventional body fluid absorbing element. It is a plane schematic diagram of the paper diaper of this form. FIG. 2 is a schematic cross-sectional view taken along the line II of FIG. 1. It is the schematic which shows the manufacturing flow of a fiber assembly. It is the schematic which shows the manufacturing flow of a bodily fluid absorber and a bodily fluid absorption element.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Top sheet, 2 ... Waterproof sheet, 3 ... Body fluid absorption element, 4 ... Body fluid absorber, 5 ... Cover sheet, 5a ... Front side cover sheet, 5b ... Back side cover sheet, 6 ... Second sheet, 10 ... Paper diaper, 33 ... fiber assembly, 35 ... absorbing polymer.

Claims (5)

A body fluid absorbing element comprising a body fluid absorber and a covering sheet of the body fluid absorber,
In the covering sheet, the covering sheet provided on the front surface side of the body fluid absorber and the covering sheet provided on the back surface side are joined at the outer periphery of the body fluid absorber, or joined at the outer periphery of the body fluid absorber. This joined portion is folded outward and joined to the back side of the back side covering sheet,
The body fluid-absorbing element, wherein the surface-side covering sheet is formed of a nonwoven fabric and the back-side covering sheet is formed of tissue paper.   The body fluid-absorbing element according to claim 1, wherein the nonwoven fabric is formed of fibers having a diameter of 0.02 dtex or more.   The bodily fluid absorbing element according to claim 1 or 2, wherein the bodily fluid absorbent includes an absorbent polymer, and the nonwoven fabric has an interfiber distance of 50 µm or more and less than 850 µm. A bodily fluid absorbent article comprising a bodily fluid absorbent body and a bodily fluid absorbing element comprising a covering sheet of the bodily fluid absorbent body, and at least one article sheet provided on the surface side of the bodily fluid absorbent element,
The covering sheet is formed by joining the covering sheet provided on the front surface side of the body fluid absorber and the covering sheet provided on the back surface side, on the outer periphery of the body fluid absorber,
The body surface absorbent sheet according to claim 1, wherein the surface side covering sheet has a flat surface and a raised surface on the back surface.   The bodily fluid absorbent article according to claim 4, wherein the covering sheet includes only the front surface side covering sheet, not the back surface side covering sheet, and a waterproof sheet is provided on the back surface side of the body fluid absorbing element.

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