JP4859508B2 - Absorbent articles - Google Patents

Description

  The present invention relates to absorbent articles such as disposable diapers, sanitary napkins, urine pads, and absorbent pads. More specifically, the present invention relates to an absorbent article provided with an absorber under a top sheet.

In recent years, devices that have a problem of dispersion of body pressure, such as nursing beds (hereinafter, also simply referred to as “body pressure dispersion devices”), have been proposed one after another as technological innovation has advanced and body pressure dispersion performance has been improved. ing. By improving the body pressure dispersion performance, fatigue, rough skin, etc. of the cared person are reduced.
On the other hand, as an absorbent article such as a paper diaper, an article provided with an absorber under a surface sheet has been widely used. The absorbent body used in this conventional absorbent article is formed by mixing a granular absorbent polymer into a fluffy pulp fiber aggregate (stacked pulp) (for example, see Patent Document 1). This conventional absorbent article was expected to improve the body pressure dispersion performance of the body pressure dispersing device because the absorbent polymer of the absorbent body absorbs the body fluid and expands. However, when the conventional absorbent article is subjected to body pressure from the wearer and is sandwiched between the body pressure dispersing devices, the absorbent pulp is moved and cracked due to movement of the piled pulp. was there. If the absorbent body is cracked or cracked, the body pressure dispersion performance of the body pressure dispersion device may be improved, rather than hindered.
Therefore, it is conceivable to give an absorbent polymer to a sheet of nonwoven fabric or the like that does not move like a piled pulp, thereby forming an absorbent body. However, even if an absorbent polymer is simply applied to the sheet, it is not possible to prevent the absorbent body from cracking or cracking. This is because the polymer is fixed on the nonwoven fabric surface without fixing the polymer in the voids of the nonwoven fabric.
Japanese Patent Laid-Open No. 9-16012

  SUMMARY OF THE INVENTION The main problem to be solved by the present invention is to provide an absorbent article that is free from kinking and cracking of the absorbent body.

The present invention that has solved this problem is as follows.
[Invention of Claim 1]
An absorbent article comprising a body fluid permeable top sheet, a body fluid impermeable back sheet, and an absorbent body interposed between these sheets,
The absorbent body includes an absorbent layer in which an absorbent polymer having an average particle size of 300 to 400 μm is applied to an air-through nonwoven fabric sheet composed of spiral crimped fibers at a basis weight of 40 to 200 g / m ² , and the absorbent layer A diffusion layer composed of an air-through non-woven sheet composed of spiral crimped fibers, which is bonded to the front surface and back surface of the sheet with a hot melt adhesive, and bonded only to the back surface of the diffusion layer with a hot melt adhesive It is formed by pressing a laminated structure consisting of piled fiber pulp layers,
And the air-through nonwoven fabric sheet of the absorption layer is a nonwoven fabric having a density of 0.01 to 0.13 g / cm ³ , and the absorbent polymer is fixed in the voids of the nonwoven fabric with a hot melt adhesive.
An absorbent article characterized by the above.

  Next, an embodiment of the present invention will be described. In the following, an example in which the absorbent article is a “fastening tape-type paper diaper” will be described.

[Shape of paper diapers, etc.]
As shown in FIGS. 1 and 2, the disposable diaper 10 of this embodiment includes a body fluid permeable top sheet 1, a body fluid impermeable back sheet 2, and an absorbent element interposed between these sheets 1 and 2. 3 and so on.

  The top sheet 1 and the back 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 or rearward or sideward than the front and rear end edges or both side edges of the absorbent element 3. Yes. The lateral extension of the topsheet 1 and the backsheet 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 this long extended portion (hereinafter also simply referred to as “extended portion”).

  Further, the top sheet 1 and the back 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.

  On the other hand, the absorbent element 3 mainly includes an absorbent body 31 and a covering sheet 32 that covers the absorbent body 31. In the absorbent element 3 of this embodiment, the shape of the absorbent body 31 is maintained by the covering sheet 32. Moreover, as shown in FIG. 1, the absorbent element 3 of the present embodiment has a substantially planar hourglass shape with a narrow central portion in the front-rear direction.

As shown in FIG. 3 and FIG. 4, the absorbent body 31 of this embodiment has at least an absorption layer 33 (33 </ b> A, 33 </ b> B) formed by applying an absorbent polymer to an air-through nonwoven fabric sheet. Then, such air-through nonwoven fabric sheet has a density 0.01~0.13g / cm ³ at (preferably 0.01~0.03g / cm ³⁾ of the nonwoven fabric, the absorbent polymer basis weight in the gap of the non-woven fabric 40 It is fixed with a hot melt adhesive so as to be ˜200 g / m ² . Since the absorbent polymer is imparted to the air-through nonwoven fabric sheet instead of the piled pulp, there is no possibility that the absorbent 31 will be cracked due to the movement of the piled pulp. Therefore, there is no possibility of obstructing the body pressure dispersion performance of the body pressure dispersion tool. Rather, when the absorbent polymer absorbs body fluid and expands, there will be a buffer material called the absorbent polymer expanded at the site where the body pressure is applied, so that the body pressure dispersion performance of the body pressure dispersing device can be improved. Be expected.

  In addition, when the absorbent polymer is mixed in the piled pulp, the absorbent polymer is little or no longer present at the portion where the piled pulp is small (frozen) or no longer exists (cracked). Therefore, there is a possibility that there is no buffer material called an absorbent polymer expanded at a site where body pressure is applied. Rather, usually, there is little or no fiber pile in the part where body pressure is applied, so it can be said that there is almost no effect of improving body pressure dispersion performance.

  In this embodiment, application of the absorbent polymer to the nonwoven fabric is fixed by a hot melt adhesive. This sticking is stronger when the object (object) is a non-woven fabric than a piled pulp, and therefore the movement of the absorbent polymer during wearing is reduced, and the effect of improving body pressure dispersion performance is reliably obtained. Will be. Further, for this fixation, it is preferable to first apply a hot melt adhesive to the nonwoven fabric and then mix the absorbent polymer into the voids of the nonwoven fabric. This is to fix the absorbent polymer in the voids. Without application of hot melt, the absorbent polymer cannot be fixed with sufficient strength. The same applies to the case where the hot melt is applied after the absorbent polymer is mixed.

But when the density of a nonwoven fabric exceeds 0.13 g / cm < ³ >, there exists a possibility that an absorptive polymer may not fully enter into the space | gap of a nonwoven fabric. On the other hand, if the density is less than 0.01 g / cm ³ , the absorbent polymer may not stay in the voids of the nonwoven fabric and may fall off. On the other hand, when the basis weight of the absorbent polymer exceeds 300 g / m ² , it cannot be sufficiently fixed even by the hot melt adhesive. In addition, if the usage-amount of a hot-melt-adhesive is increased, an absorber will become stiff.

  In this embodiment, the type of sheet (nonwoven fabric) that is an object (object) to which the absorbent polymer is applied is an air-through nonwoven fabric sheet. Since the air-through nonwoven fabric has a high porosity, it can impart a sufficient absorbent polymer.

  In this embodiment, there is no particular limitation on how many absorbent layers are formed by applying an absorbent polymer to the air-through nonwoven fabric sheet. As shown in FIG. 3, it is set as one layer only of the absorption layer 33, As shown in FIG. 4, it is set as two layers of the surface side absorption layer 33A and the back surface side absorption layer 33B, 3 layers which are not illustrated, 4 There can be multiple layers of 5 layers or more. When designing with appropriate consideration of the fact that the absorbent polymer application rate is too large, the absorbent polymer may be unevenly distributed, drop off, or the absorbent polymer application rate will be reduced and it will be suitable for repeated absorption. Good.

  In this embodiment, the absorbent body 31 includes a diffusion layer 34A (front surface side) made of an air-through nonwoven fabric sheet, as shown in FIG. 3 and FIG. 4, of the front surface side and the back surface side of the absorption layer 33 (33A, 33B). Diffusion layer), 34B (backside diffusion layer). Because the diffusion layers 34A and 34B allow body fluids such as urine and blood to diffuse quickly over the entire surface of the absorber 31, the entire absorption layer 33 (33A and 33B) is effectively used.

  Further, in this embodiment, the absorbent body 31 is a piled pulp on the back side of the absorption layer 33 (33A, 33B) and on the back side of the back side diffusion layer 34B as shown in FIGS. It is preferable to have a pulp layer 35 made of By having the pulp layer 35, the bodily fluid absorption speed is increased, and the bodily fluid absorption capacity is increased. In this respect, as described above, the pulp layer 35 is made of a piled pulp, and the problem of cracking is that the absorbent body 33 (33A, 33A, 33) 33B), there is almost no possibility of occurrence. Therefore, the pulp layer 35 needs to be provided on the back surface side of the absorption layer 33 (33A, 33B).

(Other)
(1) A second sheet 4 (see FIG. 2) can be interposed between the top sheet 1 and the absorbent element 3. When the second sheet 4 is interposed, the diffusibility of body fluid is improved.
(2) The absorbent element 3 can be joined to the back sheet 2. By this joining, the shape retention of the paper diaper 10 is improved. 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) Manufacture of the absorber 31 can be performed by the following procedure, for example, when the absorption layer 33 is one layer. <1> Pulp is piled to form a pulp layer 35. <2> On this pulp layer 35, a back side diffusion layer 34B made of an air-through nonwoven fabric sheet coated with a hot melt adhesive is laminated. <3> An air-through nonwoven fabric sheet (33) coated with a hot melt adhesive on the back surface is laminated and adhered on the back-side diffusion layer 34B. <4> This air-through nonwoven fabric sheet (33) After the hot melt adhesive is applied to the surface of the film, the absorbent polymer is sprayed (thereby forming the absorbent layer 33). <5> On the absorbent layer 33, the hot melt adhesive is applied to the back surface. The surface side diffusion layer 34A made of an air-through non-woven sheet is laminated and bonded, and a laminated structure of <6> or more is pressed.
(5) In addition, the absorber can be manufactured by the following procedure. <1> Only the pulp is piled up (180 g / m ² ). <2> A hot melt adhesive is applied to an air-through nonwoven fabric (40 g / m ² (density 0.016 g / cm ³ )) in a spiral manner (non-contact) at a rate of 10 g / m ² . And <2> are bonded to the air-through non-woven fabric. <4> A hot melt adhesive is applied to this by a spray method (non-contact) at 10 g / m < ² >. <5> An absorbent polymer is applied thereon from above. 170 g / m ^{2 is} sprayed <6> An air-through non-woven fabric 40 g / m ² is stacked and pressed on this.

[Material of each component]
(Surface sheet 1)
In this embodiment, the top sheet 1 has a property of transmitting body fluid. Therefore, the material of the surface sheet 1 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. For example, olefins such as polyethylene (PE) and polypropylene (PP), polyesters, polyamides, etc., synthetic fibers such as rayon and cupra, natural fibers such as cotton, etc. are used. The mixed fibers can be exemplified. 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 for obtaining flexibility and drapeability, and the thermal bond method is for obtaining bulkiness and softness.
Moreover, the surface sheet 1 may be composed of a single sheet or may be composed of a laminated sheet obtained by bonding two or more sheets. Similarly, the top sheet 1 may be composed of one sheet or two or more sheets in the planar direction.

(Body fluid absorber 31: absorbent polymer)
As an absorptive polymer, what absorbs and hold | maintains a bodily fluid 10 times or more of own weight can be used. Examples of this include starch-based, cellulose-based and synthetic polymer-based ones, such as starch-acrylic acid (salt) graft copolymer, starch-acrylonitrile copolymer saponified product, sodium carboxymethylcellulose crosslinked product, An acrylic acid (salt) polymer or the like can be used. As a shape of an absorptive polymer, the granular material normally used is used.
The quantitative arrangement and density distribution of the absorbent polymer with respect to the air-through nonwoven sheet are preferably uniform for the purpose of general purpose, but for the purpose of exhibiting special absorption characteristics, It is also preferable to bias it accordingly.
The average particle size of the absorbent polymer in the present invention is 300 to 400 μm.

(Body fluid absorber 31: accumulated fiber pulp)
In this embodiment, the raw material for the piled pulp 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, wood, which is a raw material for cellulose fibers, is preferable in terms of function and price because conifers have a longer fiber length than hardwoods.

(Back sheet 3)
In this embodiment, the back sheet 3 has a property of not transmitting body fluid. Accordingly, the material of the back sheet 3 is sufficient if 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 liquids (in this case, the waterproof film and the non-woven fabric constitute the back sheet 3 that is impermeable to bodily fluids) can be exemplified. 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 32)
In the present embodiment, the material of the covering sheet 32 is not particularly limited as long as it has a property of transmitting body fluid. For example, the same material as exemplified as the top sheet 1 can be used. Specifically, for example, a body fluid permeable sheet such as a crepe paper, a nonwoven fabric, or a perforated sheet can be used.

(Second sheet 4)
The second sheet 4 has a property of diffusing and transmitting body fluid. Therefore, the material of the second sheet 4 is sufficient as long as it exhibits this body fluid diffusion / permeability, and examples thereof include the same material as the top sheet 1. However, for example, spunlace, pulp nonwoven fabric, mixed sheet of pulp and rayon, point bond or crepe paper is preferable. In addition, the second sheet 4 is particularly preferably one having better body fluid permeability than the top sheet 1, and has a fiber density smaller than that of the top sheet 1, such as polypropylene, polyethylene, polyethylene terephthalate, polyamide, nylon, rayon, vinylon, A nonwoven fabric made of acrylic or the like is particularly preferable.

(Other)
In the form of one absorbent layer 33 illustrated in FIG. 3, the diffusion layers 34A and 34B are air-through nonwoven fabric sheets having a basis weight of 40 g / m ² , PE / PP spiral crimped fibers, and a fineness of 5.6 dtex. 33 is an air-through nonwoven fabric sheet having a basis weight of 40 g / m ² , PE / PP spiral crimped fiber, and a fineness of 5.6 dtex, and an absorbent polymer is applied by curtain bonding at a rate of 170 g / m ² . A form in which the pulp layer 35 has a basis weight of 180 g / m ² can be exemplified.
Further, in the case where the absorption layer illustrated in FIG. 4 is a two-layered form of the front side absorption layer 33A and the back side absorption layer 33B, the diffusion layers 34A and 34B have a basis weight of 40 g / m ² , PE / PP spiral crimped fibers, The air-through nonwoven fabric sheet with a fineness of 5.6 dtex, the absorbent layers 33A and 33B are both 40 g / m ² per unit area, PE / PP spiral crimped fiber, the air-through nonwoven fabric sheet with a fineness of 5.6 dtex, A mode in which the pulp layer 35 is applied by curtain bonding at a rate of 100 g / m ^{2 and} the basis weight is 180 g / m ² can be exemplified. This form has the advantage that the fixing strength of the absorbent polymer is increased and the repetitive absorption is suitable because the application rate of the absorbent polymer is smaller than that of the previous form (form having one absorbent layer).

  INDUSTRIAL APPLICABILITY The present invention can be applied as absorbent articles such as fastening tape-type paper diapers, pants-type paper diapers, sanitary napkins, absorbent pads, urine collection pads, and the like.

It is a top view of a paper diaper. It is the II sectional view taken on the line of FIG. It is a cross-sectional schematic diagram of an example of an absorber. It is a cross-sectional schematic diagram of an example of an absorber.

  DESCRIPTION OF SYMBOLS 1 ... Top sheet, 2 ... Back sheet, 3 ... Absorbing element, 4 ... Second sheet, 10 ... Paper diaper, 31 ... Absorber, 32 ... Cover sheet, 33 ... Absorbing layer, 33A ... Front side absorption layer, 33B ... Back side Absorption layer, 34A ... front side diffusion layer, 34B ... back side diffusion layer, 35 ... pulp layer.

Claims (1)

An absorbent article comprising a body fluid permeable top sheet, a body fluid impermeable back sheet, and an absorbent body interposed between these sheets,
The absorbent body includes an absorbent layer in which an absorbent polymer having an average particle size of 300 to 400 μm is applied to an air-through nonwoven fabric sheet composed of spiral crimped fibers at a basis weight of 40 to 200 g / m ² , and the absorbent layer A diffusion layer composed of an air-through non-woven sheet composed of spiral crimped fibers, which is bonded to the front surface and back surface of the sheet with a hot melt adhesive, and bonded only to the back surface of the diffusion layer with a hot melt adhesive It is formed by pressing a laminated structure consisting of piled fiber pulp layers,
And the air-through nonwoven fabric sheet of the absorption layer is a nonwoven fabric having a density of 0.01 to 0.13 g / cm ³ , and the absorbent polymer is fixed in the voids of the nonwoven fabric with a hot melt adhesive.
An absorbent article characterized by the above.

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