JP2021029685A - Absorber and absorbent article - Google Patents

Abstract

To provide an absorber that achieves both of the antibacterial properties of the absorber and the suppression of stickiness caused by a body fluid returning to the user's skin after adsorbed onto the absorber, and an absorbent article comprising the same.SOLUTION: This absorber 1 includes an absorbent polymer 3, an antibacterial agent 8, and cellulose fibers 5, wherein the absorbent polymer 3 and the antibacterial agent 8 are adhered to the cellulose fibers 5 via a binder 7. The antibacterial agent 8 is preferably attached to the surface of the binder 7. This absorbent article comprises a front side sheet and a rear side sheet and includes the absorber 1 between these sheets.SELECTED DRAWING: Figure 1

Description

The present invention relates to absorbers and absorbent articles.

Absorbents containing antibacterial agents from the viewpoint of suppressing the growth of bacteria derived from the wearer's skin and bacteria contained in body fluids such as urine, feces, sweat, and menstrual blood in the absorbers of absorbent articles such as diapers. It has been known. For example, Patent Document 1 describes an absorber in which a predetermined amount of an antibacterial agent is mixed and added to a binder that binds pulp and a super absorbent polymer.

Japanese Unexamined Patent Publication No. 2005-198701

The so-called liquid return may occur in which the body fluid absorbed by the absorber returns to the wearer's skin side. In the absorber containing the antibacterial agent, the antibacterial agent is transferred to the absorbed body fluid, so that the body fluid containing the antibacterial agent adheres to the wearer's skin by the liquid return. Body fluids containing antibacterial agents may cause stickiness, but if the content of the antibacterial agent in the absorber is reduced to prevent this, the antibacterial property of the absorber is lowered. The absorber described in Patent Document 1 does not have both the suppression of stickiness due to the reconstituted body fluid and the antibacterial property of the absorber.

Therefore, an object of the present invention is to provide an absorber having both antibacterial properties of the absorber and suppression of stickiness due to the reconstituted body fluid, and an absorbent article having the same.

The present invention provides an absorber containing a water-absorbent polymer, an antibacterial agent, and a cellulose fiber, in which the water-absorbent polymer and the antibacterial agent are adhered to the cellulose fiber via a binder.

The present invention also provides an absorbent article comprising a front surface sheet and a back surface sheet, and the absorber provided between the two sheets.

According to the present invention, it is possible to provide an absorber having both antibacterial properties of the absorber and suppression of stickiness due to the reconstituted body fluid, and an absorbent article having the same.

FIG. 1 is a diagram showing an embodiment of an absorber of the present invention, and is a cross-sectional view schematically showing a cross section of the absorber. FIG. 2 is an enlarged schematic view showing an adhesive state of the water-absorbent polymer, the antibacterial agent, and the cellulose fiber shown in FIG. FIG. 3 is a cross-sectional view schematically showing a cross section of another embodiment of the absorber of the present invention. FIG. 4 is a cross-sectional view schematically showing a cross section of still another embodiment of the absorber of the present invention. FIG. 5 is a cross-sectional view schematically showing a cross section of an absorbent core in still another embodiment of the absorber of the present invention. FIG. 6 is an enlarged schematic view of the complex shown in FIG. FIG. 7 is an enlarged schematic view of the complex in still another embodiment of the absorber of the present invention.

Hereinafter, the present invention will be described based on the preferred embodiment with reference to the drawings. 1 and 2 show a first embodiment of the absorber of the present invention. As shown in FIG. 1, the absorber 1a of the present embodiment includes an absorbent core 4 and a core wrap sheet 6 that covers the outer surface of the absorbent core 4. In the present embodiment, the absorbent core 4 is a mixed product of the water-absorbent polymer 3, the antibacterial agent 8 and the cellulose fiber 5, and the core wrap sheet 6 is composed of the antibacterial agent 8 and the cellulose fiber (not shown). As described above, the absorber 1a contains the water-absorbent polymer 3, the antibacterial agent 8, and the cellulose fiber 5.

The water-absorbent polymer 3 is a crosslinked product of various hydrogel materials, for example, a polymer or copolymer of an acrylic acid or an alkali metal salt of acrylic acid, a crosslinked product of polyacrylic acid and a salt thereof, a crosslinked product of a polyacrylate graft polymer, and starch. Alternatively, a crosslinked product of carboxymethylated cellulose, a crosslinked product of a hydrolysis product of a starch-acrylate graft copolymer, a crosslinked product of a vinyl alcohol-acrylate copolymer, a crosslinked product of maleic anhydride grafted polyvinyl alcohol, It is composed of a crosslinked isobutylene-maleic anhydride copolymer, a saponified product of a vinyl acetate-acrylic acid ester copolymer, and the like, and one of these components can be used alone or in combination of two or more. Examples of the shape of the particles of the water-absorbent polymer 3 include a spherical shape, a lump shape, a bale shape, an amorphous shape, and the like.

As the antibacterial agent 8, those used for antibacterial applications in absorbent articles such as diapers can be used without particular limitation. For example, an antibacterial metal, an antibacterial metal carrier, an organic antibacterial agent and the like can be mentioned. Examples of the metal having antibacterial activity include copper, silver, gold, lead, nickel, tin, zinc, iron, zirconium and the like. Examples of the antibacterial metal carrier include silver zeolite, divinylbenzene-2-vinylpyridine-2-vinylpyridine silver copolymer (for example, those described in JP-A-2006-307404), and aluminum / silver / sodium silicate silicate. (For example, those described in JP-A-2005-232654), a composite of silicon dioxide, zinc oxide, and aluminum oxide carrying silver or zinc (specifically, a metal-substituted silicate-like mineral carrying an antibacterial metal). , Silver zirconium phosphate, a mixture of silver and zinc zeolite, and other poorly water-soluble or water-insoluble antibacterial agents. Examples of the organic antibacterial agent include quaternary ammonium salts, specifically cationic antibacterial agents such as benzalkonium cetyl phosphate, benzethonium chloride, benzalkonium chloride, and cetylpyridinium chloride. As the antibacterial agent 8, one of the above-mentioned components can be used alone or in combination of two or more.

Examples of the cellulosic fiber 5 include cellulosic natural fibers, regenerated fibers and semi-synthetic fibers. Specific examples thereof include wood pulp fiber, rayon fiber, cotton fiber, cellulose acetate fiber and the like. Examples of the raw material pulp of the cellulose fiber include wood pulp such as coniferous kraft pulp and broadleaf kraft pulp; and non-wood pulp such as cotton pulp and straw pulp. Further, crosslinked cellulose fibers (pulp fibers) in which intramolecular or intermolecular crosslinks of cellulose are crosslinked with an appropriate cross-linking agent, or regenerated cellulose fibers such as rayon fibers having improved crystallinity of cellulose can also be used. As the cellulose fiber, one of the above-mentioned fibers can be used alone or in combination of two or more.

The absorber 1a may contain synthetic fibers, for example, thermoplastic fibers, as well as cellulose fibers. As the thermoplastic fiber, for example, a single fiber formed by using a single synthetic resin such as polyethylene, polypropylene, polyester, polyurethane, or a synthetic resin such as a composite of two or more kinds thereof was formed. Composite fibers such as core-sheath type and side-by-side type formed by using two or more kinds of synthetic resins can also be used. From the viewpoint of ensuring the liquid absorbency of the absorber 1a more reliably, the content of the synthetic fiber in the absorbent core 4 is preferably 50% by mass or less.

The water-absorbent polymer 3 and the antibacterial agent 8 are adhered to the cellulose fibers 5 via the binder 7. In the absorber 1a of the present embodiment, the binder 7 is arranged between the absorbent core 4 and the core wrap sheet 6, and the absorbent core 4 and the core wrap sheet 6 are joined via the binder 7. There is. At the interface between the absorbent core 4 and the core wrap sheet 6, the water-absorbent polymer 3 and the antibacterial agent 8 contained in the absorbent core 4 pass through the binder 7 to the cellulose fibers 5 contained in the absorbent core 4 and the cellulose fibers 5 and the antibacterial agent 8. It adheres to the cellulose fibers contained in the core wrap sheet 6 (see FIG. 2). At the interface, the antibacterial agent 8 contained in the core wrap sheet 6 is adhered to the cellulose fibers 5 contained in the absorbent core 4 and the cellulose fibers contained in the core wrap sheet 6 via the binder 7. That is, in the plane direction of the interface, the water-absorbent polymer 3, the antibacterial agent 8, and the cellulose fiber 5 in each of the core wrap sheet 6 and the absorbent core 4 are adhered to the binder 7.
Further, in the absorber 1a of the present embodiment, the binder 7 is not arranged on the inner side of the absorber 1a in the thickness direction Z. That is, in the absorber of the present invention, it is sufficient that a part of the water-absorbent polymer 3 and the antibacterial agent 8 are adhered to the cellulose fiber 5 via the binder 7, and all the water-absorbent polymer 3 and the antibacterial agent 8 are used. It does not have to be adhered to the cellulose fiber 5 via the binder 7.

Examples of the binder 7 include a water-soluble binder and a water-insoluble binder. Examples of the water-soluble binder include an anionic binder, a cationic binder, and a nonionic binder. Examples of the anionic binder include carboxymethyl cellulose salt, poly (meth) acrylic acid, poly (meth) acrylic acid salt (including partially neutralized product), and acrylamide-acrylic acid salt (including partially neutralized product) copolymer weight. Examples thereof include coalescence, maleic acid-acrylic acid salt (including partially neutralized product) copolymer, and polyamino acid salt (including partially neutralized product). Examples of the cationic binder include cationized starch, cationized sodium carboxymethyl cellulose, cationized polyvinyl alcohol and the like. Examples of the nonionic binder include polyvinyl alcohol, polyacrylamide, starch, polyethylene glycol, gum, methyl cellulose, hydroxyethyl cellulose, hydroxypropyl cellulose, hydroxypropyl methyl cellulose, polyvinylpyrrolidone and the like. Examples of the water-insoluble binder include those made of a hydrophobic thermoplastic resin, for example, styrene-ethylene-butylene-styrene (SEBS) type, styrene-isoprene-styrene (SIS) type, styrene-butylene-styrene (styrene-butylene-styrene). Examples thereof include various hot melt adhesives such as SBS) type, styrene-ethylene-propylene-styrene type (SEPS), ethylene vinyl acetate (EVA), and polyvinyl alcohol (PVA). As the binder, one of the above-mentioned components can be used alone or in combination of two or more.

The absorber 1a is used as a main liquid absorbing site in an absorbent article such as a diaper. In the absorber 1a that has absorbed body fluids such as urine, the antibacterial agent 8 is adhered to the cellulose fibers 5 via the binder 7 together with the water-absorbing polymer 3, so that the antibacterial agent 8 is attached to the absorber 1a after absorbing the liquid. Can be kept fixed. As a result, the antibacterial agent 8 is suppressed from being excessively eluted into the body fluid in the absorber 1a after absorbing the liquid. Therefore, according to the absorber 1a, stickiness due to the reconstituted body fluid can be prevented without reducing the amount of the antibacterial agent. Moreover, since the amount of the antibacterial agent is not reduced, the antibacterial property of the absorber 1a can be ensured. Furthermore, by suppressing stickiness, it is possible to maintain a good touch.

In this embodiment, the antibacterial agent 8 is attached to the surface of the binder 7. In other words, at least a part of the antibacterial agent 8 is exposed from the binder 7. With such a configuration, the antibacterial property of the absorber 1a is further improved by the contact between the exposed portion of the antibacterial agent and the bacteria. On the other hand, in the absorber described in Patent Document 1, since the antibacterial agent mixed (internally added) in the binder is embedded in the binder, sufficient antibacterial properties are not exhibited.
From the viewpoint of easily adhering the antibacterial agent 8 to the surface of the binder 7, it is preferable to externally add the antibacterial agent 8 to the binder 7 arranged on the absorber 7 by a method such as spraying or spraying.
The absorber 1a may have the antibacterial agent 8 embedded in the binder 7 together with the antibacterial agent 8 adhering to the surface of the binder 7. From the viewpoint of further improving the antibacterial property, it is preferable that the antibacterial agent 8 adhering to the surface of the binder 7 is present in a larger amount than the antibacterial agent 8 embedded in the binder 7.

The absorbent core 4 in the absorber of the present embodiment contains a water-absorbent polymer 3 and a fiber material. The absorbent core 4 may contain cellulose fibers 5. If the absorber comprises a core wrap sheet 6 containing cellulose fibers, the absorbent core 4 does not have to contain cellulose fibers. From the viewpoint of ensuring the liquid absorbency of the absorbent core 4 more reliably, the content of the cellulose fibers in the absorbent core 4 is preferably 10% by mass or more and 90% by mass or less, and more preferably 20% by mass or more and 80% by mass. It is mass% or less.
Further, a water-absorbent polymer having an antibacterial agent attached to one surface of the core wrap sheet (hereinafter, also referred to as an antibacterial agent-adhered water-absorbent polymer) may be sprayed. The antibacterial agent-adhering water-absorbent polymer can be obtained, for example, by a method of adhering antibacterial fine particles described in JP-A-2016-104119 to a superabsorbent polymer. The absorbent core 4 may be a mixed product of an antibacterial agent-adhering water-absorbent polymer and a fiber material.

The absorber 1a can be divided into three equal parts in the thickness direction Z, and the absorber 1a can be divided into an upper layer A, a lower layer C, and an intermediate layer B located between these two layers (see FIG. 1). The upper layer A is a layer arranged on the side closer to the skin in the absorbent article when the absorber 1a is incorporated into the absorbent article, and the lower layer C is a layer arranged on the side farther from the skin in the absorbent article. When the absorber includes a core wrap sheet, the absorber is divided into three equal parts in the thickness direction, including the thickness of the core wrap sheet.

From the viewpoint of arranging the water-absorbent polymer 3 on the surface layer side of the absorber to enhance the liquid retention and improve the liquid-absorbing property of the absorber, the upper layer A or the lower layer C is more water-absorbent than the intermediate layer B. It is preferable that the basis weight of the polymer is high, and it is more preferable that the upper layer A has a higher basis weight of the water-absorbent polymer than the lower layer C. Such an absorber can be obtained, for example, by appropriately changing the spraying amount of the water-absorbent polymer in the upper layer A, the intermediate layer B, and the lower layer C so that the water-absorbent polymer is unevenly distributed in the upper layer A.

From the same viewpoint as above, the basis weight of the water-absorbent polymer in the upper layer A, the intermediate layer B and the lower layer C is preferably within the following range.
The basis weight of the water-absorbent polymer 3 in the upper layer A is preferably 105% or more, more preferably 110% or more, and preferably 200% or less, more preferably, with respect to the basis weight of the water-absorbent polymer 3 in the lower layer C. Is 180% or less, preferably 105% or more and 200% or less, and more preferably 110% or more and 180% or less.
The basis weight of the water-absorbent polymer 3 in the lower layer C is preferably 105% or more, more preferably 110% or more, and preferably 200% or less, more than the basis weight of the water-absorbent polymer 3 in the intermediate layer B. The basis weight of the water-absorbent polymer 3 in the upper layer A, which is preferably 180% or less, preferably 105% or more and 200% or less, more preferably 110% or more and 180% or less, is the water absorption in the intermediate layer B and the lower layer C. On condition that it is higher than the basis weight of the polymer 3, it is preferably 10 g / m ² or more, more preferably 60 g / m ² or more, and preferably 150 g / m ² or less, more preferably 120 g / m ² or less. Yes, and more preferably 10 g / m ² or more and 150 g / m ² or less, and more preferably 60 g / m ² or more and 120 g / m ² or less.
The basis weight of the water-absorbent polymer 3 in the lower layer C is preferably higher than the basis weight of the water-absorbent polymer 3 in the intermediate layer B and lower than the basis weight of the water-absorbent polymer 3 in the upper layer A, preferably 10 g / g. m ² or more, more preferably 55 g / m ² or more, preferably 150 g / m ² or less, more preferably 115 g / m ² or less, and preferably 10 g / m ² or more and 150 g / m ² or less, more It is preferably 55 g / m ² or more and 115 g / m ² or less.
^{The basis weight of the water-absorbent polymer 3 in the intermediate layer B is preferably 10 g / m 2} or more, more preferably 50 g / m ² or more, provided that the basis weight of the water-absorbent polymer 3 in the upper layer A and the lower layer C is lower than the basis weight of the water-absorbent polymer 3. It is preferably 150 g / m ² or less, more preferably 110 g / m ² or less, and preferably 10 g / m ² or more and 150 g / m ² or less, more preferably 50 g / m ² or more and 110 g / m ² or less. Is.

From the viewpoint of arranging the cellulose fibers 5 on the surface layer side of the absorber to enhance the diffusivity of the liquid and improve the liquid absorbency of the absorber, the upper layer A or the lower layer C is made of cellulose fibers as compared with the intermediate layer B. It is preferable that the basis weight is high, and it is more preferable that the lower layer C has a higher basis weight of the cellulose fibers than the upper layer A. Such an absorber can be obtained, for example, by appropriately changing the content of the cellulose fibers in the upper layer A, the intermediate layer B and the lower layer C, or by incorporating the cellulose fibers in the core wrap sheet 6 that covers the surface of the absorbent core. can get.

From the same viewpoint as above, the basis weight of the cellulose fibers in the upper layer A, the intermediate layer B and the lower layer C is preferably within the following range.
The basis weight of the cellulose fiber 5 in the lower layer C is preferably 105% or more, more preferably 110% or more, and preferably 200% or less, more preferably 180, with respect to the basis weight of the cellulose fiber 5 in the upper layer A. % Or less, preferably 105% or more and 200% or less, and more preferably 110% or more and 180% or less.
The basis weight of the cellulose fiber 5 in the upper layer A is preferably 105% or more, more preferably 110% or more, and preferably 200% or less, more preferably more than the basis weight of the cellulose fiber 5 in the intermediate layer B. It is 180% or less, preferably 105% or more and 200% or less, and more preferably 110% or more and 180% or less.
^{The basis weight of the cellulose fiber 5 in the lower layer C is preferably 10 g / m 2} or more, more preferably 60 g / m ² or more, provided that the basis weight of the cellulose fiber 5 in the intermediate layer B and the upper layer A is higher than the basis weight of the cellulose fiber 5. It is preferably 150 g / m ² or less, more preferably 120 g / m ² or less, and preferably 10 g / m ² or more and 150 g / m ² or less, more preferably 60 g / m ² or more and 120 g / m ² or less. ..
The basis weight of the cellulose fiber 5 in the upper layer A is preferably higher than the basis weight of the cellulose fiber 5 in the intermediate layer B and lower than the basis weight of the cellulose fiber 5 in the lower layer C, preferably 10 g / m ² or more. , More preferably 150 g / m ² or more, preferably 55 g / m ² or less, more preferably 115 g / m ² or less, and preferably 10 g / m ² or more and 150 g / m ² or less, more preferably 55 g. / ^{M 2} or more and 115 g / m ² or less.
^{The basis weight of the cellulose fibers 5 in the intermediate layer B is preferably 10 g / m 2} or more, more preferably 150 g / m ² or more, provided that the basis weight of the cellulose fibers 5 in the upper layer A and the lower layer C is lower than the basis weight of the cellulose fibers 5. It is preferably 50 g / m ² or less, more preferably 110 g / m ² or less, and preferably 10 g / m ² or more and 150 g / m ² or less, more preferably 50 g / m ² or more and 110 g / m ² or less. ..

From the viewpoint of further improving the antibacterial property by arranging the antibacterial agent 8 on the surface layer side of the absorber, the upper layer A or the lower layer C preferably has a higher basis weight of the antibacterial agent than the intermediate layer B, and the lower layer C. More preferably, the basis weight of the antibacterial agent is higher than that of the upper layer A. In such an absorber, for example, the content of the antibacterial agent in the upper layer A, the intermediate layer B, and the lower layer C may be appropriately changed, or the basis weight may be taken into consideration at the interface between the absorbent core 4 and the core wrap sheet 6. Obtained by spraying an antibacterial agent.

From the same viewpoint as above, the basis weight of the antibacterial agent in the upper layer A, the intermediate layer B and the lower layer C is preferably within the following range.
The basis weight of the antibacterial agent 8 in the lower layer C is preferably 105% or more, more preferably 110% or more, and preferably 200% or less, more preferably 180, with respect to the basis weight of the antibacterial agent 8 in the upper layer A. % Or less, preferably 105% or more and 200% or less, and more preferably 110% or more and 180% or less.
The basis weight of the antibacterial agent 8 in the upper layer A is preferably 105% or more, more preferably 110% or more, and preferably 200% or less, more preferably more than the basis weight of the antibacterial agent 8 in the intermediate layer B. It is 180% or less, preferably 105% or more and 200% or less, and more preferably 110% or more and 180% or less.
^{The basis weight of the antibacterial agent 8 in the lower layer C is preferably 0.00003 g / m 2} or more, more preferably 0.0001 g / m, provided that the basis weight of the antibacterial agent 8 in the intermediate layer B and the upper layer A is higher than the basis weight of the antibacterial agent 8. is ² or more, and preferably 0.3 g / ^{m 2} or less, more preferably 0.1 g / ^{m 2} or less, and preferably 0.00003g / ^{m 2} or more 0.3 g / ^{m 2} or less, more preferably 0.0001 g / ^{m 2} or more 0.1 g / ^{m 2} or less.
The basis weight of the antibacterial agent 8 in the upper layer A is preferably higher than the basis weight of the antibacterial agent 8 in the intermediate layer B and lower than the basis weight of the antibacterial agent 8 in the lower layer C, preferably 0.00003 g / m. ² or more, more preferably 0.00009g / ^{m 2} or more, and preferably 0.3 g / ^{m 2} or less, and more preferably not more than 0.09 g / ^{m 2,} and preferably 0.00003g / ^{m 2} or more 0.3 g / ^{m 2} or less, more preferably 0.00009g / ^{m 2} or more 0.09 g / ^{m 2} or less.
^{The basis weight of the antibacterial agent 8 in the intermediate layer B is preferably 0.00003 g / m 2} or more, more preferably 0.00008 g / m, provided that the basis weight of the antibacterial agent 8 in the upper layer A and the lower layer C is lower than the basis weight of the antibacterial agent 8. is ² or more, and preferably 0.3 g / ^{m 2} or less, and more preferably not more than 0.08 g / ^{m 2,} and preferably 0.00003g / ^{m 2} or more 0.3 g / ^{m 2} or less, more preferably 0.00009g / ^{m 2} or more 0.08 g / ^{m 2} or less.

From the viewpoint of arranging the binder 7 on the surface layer side of the absorber to more stably fix the antibacterial agent, it is preferable that the upper layer A or the lower layer C has a higher basis weight of the binder than the intermediate layer B, and the lower layer. It is more preferable that C has a higher binder basis weight than the upper layer A. Such an absorber can be obtained, for example, by appropriately arranging a binder at the interface between the absorbent core 4 and the core wrap sheet 6 in consideration of the basis weight.

From the same viewpoint as above, the basis weight of the binder in the upper layer A, the intermediate layer B and the lower layer C is preferably within the following range.
The basis weight of the binder 7 in the lower layer C is preferably 105% or more, more preferably 110% or more, and preferably 200% or less, more preferably 180% or less, based on the basis weight of the binder 7 in the upper layer A. It is preferably 105% or more and 200% or less, and more preferably 110% or more and 180% or less.
The basis weight of the binder 7 in the upper layer A is preferably 105% or more, more preferably 110% or more, and preferably 200% or less, more preferably 180%, based on the basis weight of the binder 7 in the intermediate layer B. It is preferably 105% or more and 200% or less, and more preferably 110% or more and 180% or less.
^{The basis weight of the binder 7 in the lower layer C is preferably 1 g / m 2} or more, more preferably 4 g / m ² or more, provided that it is higher than the basis weight of the binder 7 in the intermediate layer B and the upper layer A. It is preferably 20 g / m ² or less, more preferably 19 g / m ² or less, and preferably 1 g / m ² or more and 20 g / m ² or less, more preferably 4 g / m ² or more and 19 g / m ² or less.
The basis weight of the binder 7 in the upper layer A is preferably higher than the basis weight of the binder 7 in the intermediate layer B and lower than the basis weight of the binder 7 in the lower layer C, preferably 1 g / m ² or more, more preferably. Is 3 g / m ² or more, preferably 20 g / m ² or less, more preferably 18 g / m ² or less, and preferably 1 g / m ² or more and 20 g / m ² or less, more preferably 3 g / m ^2. More than 18 g / m ² or less.
The basis weight of the binder 7 in the intermediate layer B, a condition that is lower than the basis weight of the binder 7 in the upper layer A and lower layer C, is preferably 1 g / m ² or more, more preferably 2 g / m ² or more, It is preferably 20 g / m ² or less, more preferably 17 g / m ² or less, and preferably 1 g / m ² or more and 20 g / m ² or less, more preferably 2 g / m ² or more and 17 g / m ² or less.
Each basis weight of the water-absorbent polymer, the cellulose fiber, the antibacterial agent, and the binder is measured by the following method.

<Measuring method for each basis weight of water-absorbent polymer, cellulose fiber, antibacterial agent, and binder>
The absorber is divided into three equal parts in the thickness direction, and the upper layer A, the intermediate layer B, and the lower layer C are cut out, respectively. After measuring the mass of each of these layers, the water-absorbent polymer and the fiber material of each layer are separated, and the mass of each of the water-absorbent polymer and the fiber material is further measured. For the separation of the water-absorbent polymer and the fiber material, various methods capable of almost completely separating the water-absorbent polymer and the fiber material can be used without particular limitation. For example, the difference in particle size may be used for sieving with a fine mesh, and the difference in mass may be used to place the pulp under an air volume such that only the pulp is scattered, and the weight before and after the scattering is measured. May be good. Further, each layer is immersed in an ascorbic acid solution and exposed to sunlight to dissolve the water-absorbent polymer, the weight of the residual fiber after washing with water is obtained, and the mass of the residual fiber after washing with water is subtracted from the weight of the cut-out absorber. It may be calculated. For the identification of cellulosic fibers and other fiber types in the separated fiber materials, and for the analysis of the mass and content ratio of the identified fibers, JIS L 1030-1 (Part 1 Fiber Identification), JIS L 1030-2 The standard of (Part 2 Method for testing the mixing ratio of textile products) can be used as appropriate.

For each of the upper layer A, the intermediate layer B, and the lower layer C taken ^{out, 300 mm 2} or more is cut out from an arbitrary place in a plan view, and this is used as a measurement sample. If the cut-out area at one location ^{is less than 300 mm 2} , cut out measurement samples from multiple locations so that the total area is 300 mm ² or more. Next, the measurement sample is subjected to a multi-step solvent extraction method from a non-polar solvent to a polar solvent, and the antibacterial agent and the binder present in each layer are separated to obtain a solution containing a single composition. The obtained solution is dried and solidified, and 1H-NMR (nuclear magnetic resonance), IR (infrared spectroscopy), LC (liquid chromatography), GC (gas chromatography), MS (mass spectrometry), GPC (gel). Permeation chromatography), fluorescent X-ray, etc. are combined to identify the chemical structure of the antibacterial agent and the binder. Further, using an agent having a specified chemical structure as a standard substance, a calibration curve is prepared by a well-known analytical means such as GC and LC, and the antibacterial agent and the binder in the measurement sample are quantified. Based on this quantification result, the basis weight of the antibacterial agent or the binder is determined. When a plurality of types of antibacterial agents are present in the measurement sample, the basis weight of the antibacterial agent is determined based on the total mass of each antibacterial agent. Similarly, when a plurality of types of binders are present in the measurement sample, the basis weight of the binders is determined based on the total mass of each binder.

From the viewpoint of further reducing the amount of the antibacterial agent in the body fluid that returns to the liquid and further suppressing the stickiness, the antibacterial agent is preferably a component that exhibits a positive charge when ionized in water. When the water-absorbent polymer exhibits a negative charge when ionized in water, the fixation of the antibacterial agent can be improved by the interaction between the antibacterial agent and the water-absorbent polymer. Examples of such an antibacterial agent include the above-mentioned cationic antibacterial agent.

The binder 7 is preferably made of a hydrophobic thermoplastic resin from the viewpoint of improving the fixation of the antibacterial agent 8 in the absorber and further suppressing the antibacterial agent from returning together with the body fluid. Examples of the hydrophobic thermoplastic resin include the hot melt adhesive described above.

From the viewpoint of improving the absorption performance of the absorber 1a, the water-absorbent polymer 3 is preferably one that can absorb and retain 20 times or more, particularly 30 times or more of its own weight if the object is urine, and if it is blood, its own weight. It is preferable that the polymer can absorb and retain 1 times or more, preferably 3 times or more of the above. The upper limit of water absorption / retention in the water-absorbent polymer 3 is not particularly limited, but 1000 times its own weight can be used as a guideline for the upper limit.

As the core wrap sheet 6, a liquid-permeable sheet conventionally used for an absorber in the art can be used without particular limitation. Examples of the core wrap sheet 6 include paper such as tissue paper, fiber sheets such as non-woven fabrics (spunbonded non-woven fabrics, spunlaced non-woven fabrics such as acrylic and rayon), and perforated films. The core wrap sheet 6 is preferably liquid-permeable and hydrophilic, and those containing hydrophilic fibers are preferably used.

In the core wrap sheet 6, the basis weight of the cellulose fibers may be different between those arranged in the upper layer A and those arranged in the lower layer C. From the viewpoint of further improving the diffusivity of the liquid, it is preferable that the core wrap sheet 6a arranged in the lower layer C has a higher basis weight of the cellulose fibers than the core wrap sheet 6b arranged in the upper layer A. From the same viewpoint as above, it is preferable that the basis weight of the cellulose fibers in the core wrap sheets 6a and 6b arranged in the upper layer A and the lower layer C is within the following range. The core wrap sheet 6a arranged in the lower layer C is preferably 105% or more, more preferably 110% or more, and preferably 200% or less, more preferably more than the core wrap sheet 6b arranged in the upper layer A. Is 180% or less, preferably 105% or more and 200% or less, and more preferably 110% or more and 180% or less.
^{The basis weight of the cellulose fibers 5 in the core wrap sheet 6b arranged in the lower layer C is preferably 5 g / m 2} or more on condition that the basis weight of the cellulose fibers in the core wrap sheet 6a arranged in the upper layer A is higher than the basis weight of the cellulose fibers in the core wrap sheet 6a arranged in the upper layer A. , More preferably 8 g / m ² or more, preferably 40 g / m ² or less, more preferably 30 g / m ² or less, and preferably 5 g / m ² or more and 40 g / m ² or less, more preferably 8 g. / M ² or more and 30 g / m ² or less.
The basis weight of the cellulose fibers 5 in the core wrap sheet 6a arranged in the upper layer A is preferably 5 g / m ² or more, more preferably 7 g / m ² or more, and preferably 38 g / m ² or less, more preferably. It is 28 g / m ² or less, preferably 5 g / m ² or more and 38 g / m ² or less, and more preferably 7 g / m ² or more and 28 g / m ² or less.

The core wrap sheet 6 of the present embodiment contains cellulose fibers (not shown), but when the absorbent core 4 contains cellulose fibers, the core wrap sheet 6 does not have to contain cellulose fibers.

In the present embodiment, one surface of the core wrap sheet 6 is supported with the antibacterial agent 8 via a binder 7 applied to the surface and is bonded to the surface of the absorbent core 4. When the binder 7 is applied to one surface of the core wrap sheet 6 from the viewpoint of enhancing the liquid absorption property of the absorber, the binder 7 is irregularly or regularly formed into a fiber net (that is, fibrous and mesh-like). It is preferable that it is applied. From the same viewpoint as above, it is preferable that the binder 7 is coated so as to generate a non-coated portion by using, for example, a spiral type, a summit type, an omega type, or a curtain type device. When the coating width per device is limited, a plurality of coating devices may be used or a device for spraying the binder in a mist form may be used depending on the desired coating width.

From the viewpoint of enhancing the liquid absorption property of the absorber, the coating amount (basis weight) of the binder 7 in the core wrap sheet 6 is preferably 1 g / m ² or more and 20 g / m ² or less, more preferably 2 g / m ² or more and 18 g /. It is m ² or less, more preferably 3 g / m ² or more and 17 g / m ² or less.

3 to 6 show other embodiments of the absorber of the present invention. Regarding the second to fifth embodiments to be described later, the components different from the first embodiment shown in FIGS. 1 and 2 will be mainly described, and the same components will be designated by the same reference numerals and the description thereof will be omitted. The description of the first embodiment is appropriately applied to the components not particularly described.

In the first embodiment described above, the absorbent core 4 contains the water-absorbent polymer 3 and the cellulose fiber 5, but the absorbent body 1b of the second embodiment shown in FIG. 3 contains the core wrap sheets 6a and 6b and water-absorbing material. It is composed of a laminate in which the sex polymer 3 is laminated. That is, in the absorbent body 1b, the water-absorbent polymer 3 is arranged between the core wrap sheets 6a and 6b, and the water-absorbent polymer 3 constitutes the absorbent core 4. In the present embodiment, the binder 7 is applied to one surface of the core wrap sheet 6, and the antibacterial agent 8 is sprayed on the binder 7. In the absorber 1b of the present embodiment, the core wrap sheet 6 contains cellulose fibers (not shown) and an antibacterial agent 8. The water-absorbent polymer 3 in the absorber 1b, the antibacterial agent 8 in the core wrap sheet 6, and the antibacterial agent 8 sprayed on the binder 7 adhere to the cellulose fibers in the core wrap sheet 6 in the planar direction via the binder 7. doing. Such an absorber 1b can be produced, for example, by the following method. First, two core wrap sheets coated with the binder 7 on one surface are prepared, and the water-absorbent polymer 3 is sprayed on the surface of the one core wrap sheet coated with the binder 7. The above-mentioned absorber can be obtained by superimposing the other core wrap sheet on the surface coated with the binder 7 so that the surface coated with the binder 7 and the water-absorbent polymer 3 face each other. This absorber is a polymer sheet having a structure in which the water-absorbent polymer 3 is sandwiched between core wrap sheets. The absorber of the present embodiment is a laminate of core wrap sheets 6a and 6b and a deposit of a water-absorbent polymer, or a laminate of core wrap sheets 6a and 6b and a mixed dry matter containing a water-absorbent polymer. You may. The mixed dried product is obtained, for example, by drying a mixed solution containing a water-absorbent polymer and a water-soluble polymer.

In the absorber 1c of the third embodiment shown in FIG. 4, the absorbent core 4 includes the mixed product fiber layer 41 and the water-absorbent polymer layer 43, and the other absorbers 1c and the absorber 1b of the second embodiment. It has a similar configuration. The mixed product layer 41 is made of a mixed product of a water-absorbent polymer 3 and a fiber material. The mixed product layer 41 contains cellulose fibers 5 as a fiber material. The water-absorbent polymer layer 43 is composed of a deposit of the water-absorbent polymer 3. In the absorber 1c of the present embodiment, the core wrap sheet 6 contains cellulose fibers (not shown) and an antibacterial agent 8. The water-absorbent polymer 3 in the mixed triple product layer 41 of the present embodiment, the antibacterial agent 8 in the core wrap sheet 6, and the antibacterial agent 8 sprayed on the binder 7 are mixed product fibers in the plane direction via the binder 7. It is adhered to the cellulose fibers in the layer 41 and the core wrap sheet 6. Such an absorber 1c can be obtained, for example, by laminating the above-mentioned mixed product fiber and a water-absorbent polymer between the core wrap sheets 6a and 6b. The water-absorbent polymer layer 43 may be prepared by arranging a water-absorbent polymer, a deposit of the water-absorbent polymer, or the mixed dry matter described above on a core wrap sheet having a binder 7 coated on one surface. An antibacterial agent may be sprayed on the surface of the core wrap sheet coated with the binder 7.

From the viewpoint of improving the liquid absorbency of the absorber, the mixed product layer 41 is preferably arranged on the upper layer A side of the water-absorbent polymer layer 43 in the thickness direction Z of the absorber.

In the first to third embodiments described above, the binder 7 is arranged between the core wrap sheet 6 and the absorbent core 4, but the absorbent core may include the binder 7. The absorbent core 4a of the fourth embodiment shown in FIGS. 5 and 6 contains a complex 10 in which a water-absorbent polymer 3, an antibacterial agent 8, and a cellulose fiber 5 are adhered via a binder.

In the complex 10a in the fourth embodiment, as shown in FIGS. 5 and 6, the binder 7a is fibrous. In the composite 10a, the bonding mode via the fibrous binder 7a is not particularly limited, and the water-absorbent polymer 3 and the antibacterial agent 8 to be bonded may be singular or plural. The fibrous binder 7a is preferably a hydrophilic adhesive having a fibrous form, and examples thereof include polyvinyl alcohol and carboxymethyl cellulose. The absorbent core 4a containing the composite 10a is obtained, for example, by mixing a fibrous binder 7a, a water-absorbent polymer 3 and an antibacterial agent 8 to obtain an adhesive in which the water-absorbent polymer 3 and the antibacterial agent 8 are adhered to each other. , Obtained by mixing and stacking the adhesive and the cellulose fiber 5. Alternatively, it can be obtained by mixing and stacking a mixture of the fibrous binder 7a and the above-mentioned antibacterial agent-adhering water-absorbent polymer and the cellulose fiber 5. Further, the surface of the mixed product of the antibacterial agent-adhering water-absorbent polymer and the cellulose fiber may be sprayed with the fibrous binder 7a, and the mixed product may be coated with a core wrap sheet containing the cellulose fiber. Good. In this case, the mixed product fiber constitutes the absorbent core, and the composite 10a is formed at the interface between the absorbent core and the core wrap sheet.

The complex 10a in the fourth embodiment was formed by the fibrous binder 7a, but the binder forming the complex 10 does not have to be fibrous. In the composite 10b in the fifth embodiment, a part of the surface of the water-absorbent polymer 3 is coated with the binder 7, and the water-absorbent polymer 3 and the antibacterial agent 8 adhere to the cellulose fiber 5 in the coating portion 31. (See Fig. 7). In the absorbent core containing such a composite 10b, for example, a binder 7 is sprayed on a part of the surface of the water-absorbent polymer 3, and this is mixed with the antibacterial agent 8 to obtain the water-absorbent polymer 3 and the antibacterial agent 8. It is obtained by mixing and stacking the adhesive and the cellulose fiber 5 after obtaining an adhesive to which the adhesive is adhered.

The absorbent core in the fourth and fifth embodiments may contain the above-mentioned complex 10 together with the water-absorbent polymer 3 which does not form the complex, the antibacterial agent 8, and the cellulose fiber 5. That is, all the water-absorbent polymers 3, the antibacterial agent 8, and the cellulose fibers 5 in the absorbent core do not have to form the complex 10, and may form the complex 10.

Further, the absorbers of the 4th and 5th embodiments may or may not include a core wrap sheet.

The above-mentioned absorber can be preferably used as an absorber of an absorbent article. Absorbable articles are mainly used for absorbing and retaining body fluids excreted from the body such as urine and menstrual blood. Absorbent articles include, but are not limited to, for example, disposable diapers, sanitary napkins, incontinence pads, panty liners, etc., and broadly include articles used for absorbing liquid discharged from the human body. To do. The absorbent article typically comprises a front surface sheet and a back surface sheet, and comprises a liquid-retaining absorber interspersed between the two sheets. The absorbent article may further include various members according to its specific use. Such members are known to those of skill in the art.

Although the present invention has been described above based on the preferred embodiment thereof, the present invention is not limited to the above-described embodiment. For example, in the above-described embodiment, the core wrap sheet 6 is composed of two sheets and is arranged in the upper layer A and the lower layer C of the absorber, but the core wrap sheet is composed of one sheet. May be good. In this case, the core wrap sheet 6 may be in a mode in which the entire outer surface of the absorbent core 4 is covered. For example, using only one core wrap sheet 6, the entire outer surface of the absorbent core 4 is covered in a tubular shape by the core wrap sheet 6, and both ends of the tubular core wrap sheet 6 are opened. May be sealed by a joining means such as adhesion or crimping.
In the above-described embodiment, the core wrap sheet 6 and the absorbent core 4 face each other so as to be in direct contact with each other without any intervention between the core wrap sheet 6 and the absorbent core 4. The core wrap sheet 6 and the absorbent core 4 may face each other with a sheet such as a non-woven fabric interposed between the core wrap sheet 6 and the absorbent core 4.

Regarding the above-described embodiment, the present invention further discloses the following absorber and an absorbent article comprising the following absorber.
<1>
An absorbent body comprising a water-absorbent polymer, an antibacterial agent, and a cellulose fiber, wherein the water-absorbent polymer and the antibacterial agent are adhered to the cellulose fiber via a binder.
<2>
The absorber according to <1>, wherein the antibacterial agent is attached to the surface of the binder.
<3>
The absorber is divided into three equal parts in the thickness direction, and the absorber is arranged in an absorbent article on the side closer to the skin, the lower layer arranged on the side farther from the skin, and between the upper layer and the lower layer. The absorber according to <1> or <2>, wherein the upper layer or the lower layer has a higher basis weight of the water-absorbing polymer than the intermediate layer when divided into intermediate layers located in.
<4>
The absorber according to <3>, wherein the upper layer has a higher basis weight of the water-absorbent polymer than the lower layer.
<5>
The basis weight of the water-absorbent polymer in the upper layer is 105% or more and 200% or less, preferably 110% or more and 180% or less with respect to the basis weight of the water-absorbent polymer in the lower layer. Absorbents described in.
<6>
The basis weight of the water-absorbent polymer in the lower layer is 105% or more and 200% or less, preferably 110% or more and 180% or less, based on the basis weight of the water-absorbent polymer in the intermediate layer. > The absorber according to any one of>.
<7>
The basis weight of the water-absorbent polymer in the upper layer is 10 g / m ² or more and 150 g / m ² or less, preferably 60 g / m ² or more and 120 g / m ² or less, according to any one of <3> to <6>. Absorber.
<8>
The absorber is divided into three equal parts in the thickness direction, and the absorber is arranged in an absorbent article on the side closer to the skin, the lower layer arranged on the side farther from the skin, and between the upper layer and the lower layer. The absorber according to any one of <1> to <7>, wherein the upper layer or the lower layer has a higher basis weight of the cellulose fibers than the intermediate layer when divided into the intermediate layers located in. ..
<9>
The absorber according to <8>, wherein the lower layer has a higher basis weight of the cellulose fibers than the upper layer.
<10>
The basis weight of the cellulose fibers in the upper layer is 105% or more and 200% or less, preferably 110% or more and 180% or less with respect to the basis weight of the cellulose fibers in the intermediate layer. The absorber described.

<11>
The basis weight of the cellulose fibers in the lower layer is 105% or more and 200% or less, preferably 110% or more and 180% or less with respect to the basis weight of the cellulose fibers in the upper layer, any of the above <8> to <10>. The absorber according to 1.
<12>
The basis weight of the cellulose fiber in the lower layer is 10 g / m ² or more and 150 g / m ² or less, preferably 60 g / m ² or more and 120 g / m ² or less, according to any one of <8> to <11>. Absorber.
<13>
The absorber is divided into three equal parts in the thickness direction, and the absorber is arranged in an absorbent article on the side closer to the skin, the lower layer arranged on the side farther from the skin, and between the upper layer and the lower layer. The absorber according to any one of <1> to <12>, wherein the upper layer or the lower layer has a higher basis weight of the antibacterial agent than the intermediate layer when divided into the intermediate layers located in. ..
<14>
The absorber according to <13>, wherein the lower layer has a higher basis weight of the antibacterial agent than the upper layer.
<15>
The basis weight of the antibacterial agent in the upper layer is 105% or more and 200% or less, preferably 110% or more and 180% or less with respect to the basis weight of the antibacterial agent in the intermediate layer. The absorber described.
<16>
The basis weight of the antibacterial agent in the lower layer is 105% or more and 200% or less, preferably 110% or more and 180% or less with respect to the basis weight of the antibacterial agent in the upper layer, any of the above <13> to <15>. The absorber according to 1.
<17>
The basis weight of the antimicrobial agent in the lower layer, 0.00003g / ^{m 2} or more 0.3 g / ^{m 2} or less, more preferably 0.1 g / ^{m 2} or less 0.0001 g / ^{m 2} or more, the <13> - The absorber according to any one of <16>.
<18>
The absorber is divided into three equal parts in the thickness direction, and the absorber is arranged in an absorbent article on the side closer to the skin, the lower layer arranged on the side farther from the skin, and between the upper layer and the lower layer. The absorber according to any one of <1> to <17>, wherein the upper layer or the lower layer has a higher basis weight of the binder than the intermediate layer when divided into the intermediate layers located in.
<19>
The absorber according to <18>, wherein the lower layer has a higher basis weight of the binder than the upper layer.
<20>
The basis weight of the binder in the upper layer is 105% or more and 200% or less, preferably 110% or more and 180% or less with respect to the basis weight of the antibacterial agent in the lower layer, according to <18> or <19>. Absorber.

<21>
The basis weight of the binder in the lower layer is 105% or more and 200% or less, preferably 110% or more and 180% or less with respect to the basis weight of the antibacterial agent in the upper layer, any of the above <18> to <20>. The absorber according to 1.
<22>
The basis weight of the binder in the upper layer is 1 g / m ² or more and 20 g / m ² or less, preferably 3 g / m ² or more and 18 g / m ² or less, according to any one of <18> to <21>. Absorber.
<23>
The absorber comprises the water-absorbent polymer, the antibacterial agent, and a core wrap sheet that coats the outer surface of the cellulose fibers.
The absorber is divided into three equal parts in the thickness direction, and the absorber is arranged in an absorbent article on the side closer to the skin, the lower layer arranged on the side farther from the skin, and between the upper layer and the lower layer. When divided into the intermediate layers located in, the core wrap sheet arranged in the lower layer has a higher basis weight of the cellulose fibers than the core wrap sheet arranged in the upper layer. 22> The absorber according to any one of 22>.
<24>
The absorber according to any one of <1> to <23>, wherein the antibacterial agent is a component that exhibits a positive charge when ionized in water.
<25>
The absorber according to <24>, wherein the antibacterial agent is one or more selected from benzalkonium cetyl phosphate, benzethonium chloride, benzalkonium chloride, and cetylpyridinium chloride.
<26>
The absorber according to any one of <1> to <25>, wherein the binder is made of a hydrophobic thermoplastic resin.
<27>
The pre-hydrophobic thermoplastic resin is styrene-ethylene-butylene-styrene (SEBS) type, styrene-isoprene-styrene (SIS) type, styrene-butylene-styrene (SBS) type, styrene-ethylene-propylene-styrene type ( The absorber according to <26> above, which is one or more selected from SEPS), ethylene vinyl acetate (EVA), and polyvinyl alcohol (PVA).
<28>
An absorbent article comprising a front surface sheet and a back surface sheet, and having an absorber according to any one of <1> to <27> between the front surface sheet and the back surface sheet.

1 Absorbent 3 Water-absorbent polymer 4 Absorbent core 5 Cellulose fiber 6 Core wrap sheet 7 Binder 10 Complex Z Thickness direction

Claims (13)

An absorbent body comprising a water-absorbent polymer, an antibacterial agent, and a cellulose fiber, wherein the water-absorbent polymer and the antibacterial agent are adhered to the cellulose fiber via a binder. The absorber according to claim 1, wherein the antibacterial agent is attached to the surface of the binder. The absorber is divided into three equal parts in the thickness direction, and the absorber is arranged in the absorbent article on the side closer to the skin, the lower layer arranged on the side farther from the skin, and between the upper layer and the lower layer. The absorber according to claim 1 or 2, wherein the upper layer or the lower layer has a higher basis weight of the water-absorbing polymer than the intermediate layer when divided into intermediate layers located in. The absorber according to claim 3, wherein the upper layer has a higher basis weight of the water-absorbent polymer than the lower layer. The absorber is divided into three equal parts in the thickness direction, and the absorber is arranged in an absorbent article on the side closer to the skin, the lower layer arranged on the side farther from the skin, and between the upper layer and the lower layer. The absorber according to any one of claims 1 to 4, wherein the upper layer or the lower layer has a higher basis weight of the cellulose fiber than the intermediate layer when divided into the intermediate layers located in. The absorber according to claim 5, wherein the lower layer has a higher basis weight of the cellulose fibers than the upper layer. The absorber is divided into three equal parts in the thickness direction, and the absorber is arranged in an absorbent article on the side closer to the skin, the lower layer arranged on the side farther from the skin, and between the upper layer and the lower layer. The absorber according to any one of claims 1 to 6, wherein the upper layer or the lower layer has a higher basis weight of the antibacterial agent than the intermediate layer when divided into intermediate layers located in. The absorber according to claim 7, wherein the lower layer has a higher basis weight of the antibacterial agent than the upper layer. The absorber is divided into three equal parts in the thickness direction, and the absorber is arranged in an absorbent article on the side closer to the skin, the lower layer arranged on the side farther from the skin, and between the upper layer and the lower layer. The absorber according to any one of claims 1 to 8, wherein the upper layer or the lower layer has a higher basis weight of the binder than the intermediate layer when divided into intermediate layers located in. The absorber according to claim 9, wherein the lower layer has a higher basis weight of the binder than the upper layer. The absorber according to any one of claims 1 to 10, wherein the antibacterial agent is a component that exhibits a positive charge when ionized in water. The absorber according to any one of claims 1 to 11, wherein the binder is made of a hydrophobic thermoplastic resin. An absorbent article comprising a front surface sheet and a back surface sheet, and having an absorber according to any one of claims 1 to 12 between the front surface sheet and the back surface sheet.

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