Absorbent articles

Abstract

To provide an absorbent article that ensures liquid permeation and prevents liquid return, and markedly suppresses propagation of germs and occurrence of ammonia odor even when body fluid remains on the top sheet.SOLUTION: An absorbent article 1 has a liquid-permeable top sheet 10, a liquid-impermeable back sheet 20, and an absorber 30 provided between both sheets. The top sheet 10 has a first fiber layer 11 including durable hydrophilic fibers, and a second fiber layer 12 that is adjacent to a non-skin-contact side of the first fiber layer 11 and includes general hydrophilic fibers and antibacterial fibers. A skin face of the first fiber layer 11 is a skin face of the top sheet 10, and a non-skin face of the second fiber layer 12 is a non-skin face of the top sheet 10. The durable hydrophilic fibers of the first fiber layer 11 have a basis weight of 3 g / m2 or more and 15 g / m2 or less, the general hydrophilic fibers of the second fiber layer 12 have a basis weight of 7 g / m2 or more and 25 g / m2 or less, and the antibacterial fibers have a basis weight of 1 g / m2 or more and 6 g / m2 or less.SELECTED DRAWING: Figure 2

Description

[Technical Field] 【0001】 This invention relates to absorbent articles. [Background technology] 【0002】 Recently, there has been a very high demand for adding antibacterial and deodorizing functions to absorbent products such as disposable diapers, light incontinence products, and pet pads. Antibacterial function, for example, suppresses the growth of various bacteria, such as ammonia-producing bacteria, after urination. In response to this demand, various absorbent products with antibacterial and / or deodorizing functions have been proposed. 【0003】 Patent Document 1 discloses an absorbent article in which an absorbent is wrapped in a carrier sheet coated with a deodorant or antibacterial agent, and the entire article is further wrapped in a surface sheet (Claim 1, Claim 7). 【0004】 Patent Document 2 discloses a diaper comprising a surface material that comes into contact with the skin, which includes synthetic fibers containing zeolite supported with silver ions, copper ions, or zinc ions; an internal fiber sheet corresponding to an absorbent, which includes the zeolite and fibers containing a deodorant; and a superabsorbent polymer inner layer (Claim 1). As the synthetic fibers containing zeolite, polyethylene terephthalate fibers, polyethylene fibers, polypropylene fibers, etc., can be used (Paragraph 0007). Furthermore, as the fibers constituting the internal fiber sheet, polyester fibers, etc., can be used (Paragraph 0009). 【0005】 Patent Document 3 discloses antibacterial cellulose fibers (product name: Cellgaia®, manufactured by Rengo Co., Ltd.) in which zeolite is supported inside the cellulose fibers and Ag, Cu, etc., is supported inside the zeolite, as well as woven fabrics, nonwoven fabrics, and paper containing the antibacterial cellulose fibers. For example, by making paper from the cellulose fibers, the paper itself can be given a deodorizing function. It is also described that woven fabrics, nonwoven fabrics, or paper containing the cellulose fibers can be used as materials for disposable diapers (paragraph 0018). 【0006】 Patent Document 4 discloses an absorbent article comprising a topsheet, a backsheet, an absorber disposed therebetween, a region between the absorber and the backsheet, and a hydrophilic deodorant sheet disposed in a region between the topsheet and the backsheet around the absorber, the hydrophilic deodorant sheet containing the antibacterial cellulose fibers described in Patent Document 3 (Claim 1, Paragraph 0026). 【Prior Art Documents】 【Patent Documents】 【0007】 【Patent Document 1】 Japanese Patent Application Laid-Open No. 2004-089322 (Claim 1, Claim 7) 【Patent Document 2】 Japanese Patent Application Laid-Open No. 05-161671 (Claim 1, Paragraphs 0007, 0009) 【Patent Document 3】 Japanese Patent No. 4149066 (Claim 1, Paragraph 0018) 【Patent Document 4】 Japanese Patent Application Laid-Open No. 2008-48775 (Claim 1, Paragraph 0026) 【Summary of the Invention】 【Problems to be Solved by the Invention】 【0008】 In recent absorbent articles, it is required to absorb multiple excretions of body fluids, and since there are many opportunities to wear a single absorbent article for a long time, it is considered that various germs are likely to multiply in this environment. In particular, when the excretion amount of body fluid is relatively large, the growth of bacteria tends to be promoted. Although the absorbent articles described in Patent Documents 1 to 4 are provided with a certain antibacterial function, the topsheet that comes into contact with the skin of the wearer does not contain an antibacterial agent. Therefore, it is impossible to effectively exert an antibacterial action (such as an inhibitory action on the growth of bacteria) on the body fluid remaining on the topsheet. 【0009】 The present invention has been made in view of the above problems, and the object of the present invention is to provide an absorbent article that has excellent liquid permeability and liquid return properties, and in which the growth of bacteria and the generation of ammonia odor are significantly suppressed even if bodily fluids remain on the top sheet. [Means for solving the problem] 【0010】 In view of the above problems, the inventors conducted diligent research. As a result, the inventors found that the above problems can be solved by arranging the top sheet in a specific ratio, wherein the top sheet comprises two fiber layers including antibacterial fibers, the first fiber layer located on the skin side of the top sheet contains durable hydrophilic fibers, and the second fiber layer located on the non-skin side of the top sheet contains antibacterial fibers and general hydrophilic fibers, and the first and second fiber layers are arranged in a specific ratio. This led to the completion of the present invention. The present invention relates to the following absorbent article. 【0011】 (1) A first aspect of the present invention is an absorbent article comprising a liquid-permeable top sheet, a liquid-impermeable back sheet, and an absorbent disposed between the top sheet and the back sheet, The top sheet comprises a first fiber layer made of durable hydrophilic fibers, and a second fiber layer adjacent to the non-skin contact surface of the first fiber layer, made of general hydrophilic fibers and antibacterial fibers, wherein the skin contact surface of the first fiber layer constitutes the skin contact surface of the top sheet, and the non-skin contact surface of the second fiber layer constitutes the non-skin contact surface of the top sheet. The basis weight of the durable hydrophilic fibers in the first fiber layer is 3 g / m². 2 More than 15g / m 2 The basis weight of the general hydrophilic fibers in the second fiber layer is 7 g / m². 2 More than 25g / m 2 The following applies, and the basis weight of the antibacterial fiber is 1 g / m². 2 More than 6g / m 2 An absorbent article characterized by the following: However, the above general hydrophilic fiber and the above durable hydrophilic fiber shall have a basis weight of 20 g / m² including the hydrophilic fiber. 2When 100 μL of 0.9% saline is dropped every 30 seconds at the same position of the air-through non-woven fabric, the dropped saline does not penetrate the air-through non-woven fabric, and it is defined by hydrophilicity evaluation that counts the number of drops when the saline forms droplets on the air-through non-woven fabric. The hydrophilic fibers contained in the air-through non-woven fabric with a hydrophilicity evaluation of 1 or more and 8 or less are general hydrophilic fibers, and the hydrophilic fibers contained in the air-through non-woven fabric with a hydrophilicity evaluation of 9 or more are durable hydrophilic fibers. (2) The second aspect of the present invention is the absorbent article according to (1), wherein the topsheet is an air-through non-woven fabric. (3) The third aspect of the present invention is the absorbent article according to (1) or (2), wherein the basis weight of the topsheet is 15 g / m 2 or more and 40 g / m 2 or less. (4) The fourth aspect of the present invention is the absorbent article according to any one of (1) to (3), wherein a liquid-diffusive second sheet is disposed between the topsheet and the absorber, and the second sheet is an air-through non-woven fabric. (5) The fifth aspect of the present invention is the absorbent article according to any one of (1) to (4), further comprising an absorber covering sheet disposed between the absorber and the topsheet, wherein the absorber covering sheet contains pulp fibers. (6) The sixth aspect of the present invention is the absorbent article according to any one of (1) to (5), wherein the ratio of the basis weight of the topsheet to the second sheet is 50% or more and 130% or less. 【Advantages of the Invention】 【0012】 According to the present invention, there is provided an absorbent article that is excellent in liquid permeability and liquid return property, and even when body fluid remains on the topsheet, the growth of miscellaneous bacteria and the generation of ammonia odor are significantly suppressed. 【Brief Description of the Drawings】 【0013】 [Figure 1] This is a schematic plan view showing the configuration of an absorbent article according to the first embodiment of the present invention. [Figure 2] Figure 1 shows a schematic cross-sectional view in the width direction along the X1-X1 cutting line. [Figure 3] Figure 1 is a schematic cross-sectional view showing the structure of the top sheet in an absorbent article. [Modes for carrying out the invention] 【0014】 In this specification, wearing an absorbent article means the state in which the absorbent article is attached to the body, regardless of whether it has absorbed bodily fluids or not. In an absorbent article, the longitudinal direction is the direction indicated by Y in the figure, which extends from the front to the back of the body through the wearer's groin when the absorbent article is worn on the body; the width direction is the direction indicated by X in the figure, which is perpendicular to the longitudinal direction; and the thickness direction is the direction indicated by Z in the figure, which is the direction in which each component is stacked. The skin-contact surface (hereinafter also simply referred to as the "skin surface") is the surface that comes into contact with the wearer's skin and the surface facing the skin when the absorbent article is worn, and the non-skin-contact surface (hereinafter also simply referred to as the "non-skin surface") is the surface that comes into contact with the wearer's clothing or the surface facing the clothing. Bodily fluids refer to liquids that are expelled from the body to the outside, such as urine, blood, and water in loose stools. 【0015】 <Absorbent Articles> The absorbent article 1 according to the first embodiment will be described below with reference to the attached drawings. Figures 1 and 2 show the absorbent article 1. Figure 3 shows the top sheet 10. These drawings do not specify the shape, dimensions, size relationships, etc., of each component in the absorbent article 1. 【0016】 The absorbent article 1 of this embodiment can be used as various absorbent articles, whether for babies or adults. Examples include pad products such as light incontinence pads and urine absorption pads, and pant-type products such as pant-type disposable diapers and tape-fastened disposable diapers. A combination of a pant-type product as an outer layer and an absorbent article 1 in the form of a pad product as an inner layer is also possible. The dimensions of the absorbent article 1 in the longitudinal direction (hereinafter simply referred to as "length") and the width direction (hereinafter simply referred to as "width") are not particularly limited, but for example, they are in the range of 100 mm to 800 mm and 50 mm to 500 mm, respectively. By adjusting the dimensions of the absorbent article 1 to the above ranges, absorbent articles 1 for various uses can be easily obtained. 【0017】 The absorbent article 1 comprises a liquid-permeable top sheet 10 located on the skin side of the wearer, a liquid-impermeable back sheet 20 located opposite the top sheet 10 on the side not in contact with the wearer's skin, an absorbent core 30 positioned between the top sheet 10 and the back sheet 20, a second sheet 40 and an absorbent core covering sheet 50 positioned between the top sheet 10 and the absorbent core 30, sequentially from the skin side to the non-skin side of the wearer, and a pair of three-dimensional gathers 60 arranged so as to extend longitudinally near both ends in the width direction of the absorbent article 1. 【0018】 As shown in Figure 3, the top sheet 10 of this embodiment has a structure in which two fiber layers are superimposed in the thickness direction: a first fiber layer 11 located on the skin side of the wearer and containing durable hydrophilic fibers, and a second fiber layer 12 located on the non-skin side of the wearer and containing antibacterial fibers and general hydrophilic fibers. According to this embodiment, the above-mentioned structure of the top sheet 10 not only provides excellent bodily fluid permeability and fluid return properties, but also excellent antibacterial properties. Even when the absorbent article 1 is worn for a long time, the growth of bacteria is suppressed, and the generation of ammonia odor or bacterial growth odor, as well as adhesion to the wearer's clothing, is greatly reduced. 【0019】 The absorbent article 1 of this embodiment requires a top sheet 10, a back sheet 20, and an absorbent body 30, while one or more of the second sheet 40, absorbent body covering sheet 50, and three-dimensional gathers 60 are components that can be used arbitrarily depending on the form and application of the absorbent article 1. Various known modifications can be made to the absorbent article 1. The configuration of each component will be described in more detail below, in the order of top sheet 10, back sheet 20, absorbent body 30, second sheet 40, absorbent body covering sheet 50, and three-dimensional gathers 60. 【0020】 <Top sheet> The top sheet 10 includes a first fiber layer 11 located on the skin side of the wearer and a second fiber layer 12 located on the non-skin side of the wearer. Therefore, the skin side of the first fiber layer 11 becomes the skin side of the top sheet 10, and the non-skin side of the second fiber layer 12 becomes the non-skin side of the top sheet 10. The first fiber layer 11 includes durable hydrophilic fibers, and the second fiber layer 12 includes antibacterial fibers and general hydrophilic fibers. The first fiber layer 11 may consist of durable hydrophilic fibers, and may also include other fibers together with the durable hydrophilic fibers, to the extent that it does not impair the effect of the water-resistant hydrophilic fibers. The second fiber layer 12 may consist of general hydrophilic fibers and antibacterial fibers, and may also include other fibers to the extent that it does not impair the effect of these fibers. Examples of the aforementioned other fibers in the first fiber layer 11 and the second fiber layer 12 include one or more types of synthetic fibers made of synthetic resins such as polypropylene and polyethylene, regenerated fibers such as rayon, and natural fibers such as cotton and cellulose fibers. 【0021】 For the first fiber layer 11 and the second fiber layer 12, for example, a substrate in the form of a sheet or film can be used. Specific examples of the substrate from the viewpoint of liquid permeability include nonwoven fabrics such as air-through nonwoven fabric, thermal-bonded nonwoven fabric, and spunbond nonwoven fabric; composite nonwoven fabrics such as thermal-bonded nonwoven fabric / spunbond nonwoven fabric laminates; foamed films such as urethane foam; and composite sheets which are laminates of two or more of these. Among these, nonwoven fabrics are preferred from the viewpoint of liquid permeability, and air-through nonwoven fabrics are more preferred. 【0022】 The first fiber layer 11 and the second fiber layer 12 may be embossed or perforated on their surfaces according to known methods in order to improve liquid permeability. Furthermore, the first fiber layer 11 and the second fiber layer 12 may contain one or more of the following in order to reduce skin irritation: lotion, antioxidant, anti-inflammatory component, pH adjuster, moisturizer, etc. The top sheet 10 may be coated with an organic acid such as citric acid, glutamic acid, or malic acid as a weakly acidic solution, to the extent that it does not impair water absorption performance. 【0023】 The durable hydrophilic fibers contained in the first fiber layer 11 and the general hydrophilic fibers contained in the second fiber layer 12 are defined based on the results of the following hydrophilicity test. (Hydrophilicity test) Using hydrophilic fibers, basis weight 20 g / m² 2 An air-through nonwoven fabric is prepared, and 100 μL of 0.9% saline solution is dropped onto the same location on the obtained air-through nonwoven fabric every 30 seconds. The number of drops in which the dropped saline solution does not penetrate the air-through nonwoven fabric but forms droplets on the air-through nonwoven fabric is then measured. Hydrophilic fibers contained in air-through nonwoven fabrics with a drop count of 1 to 8 are defined as general hydrophilic fibers, and hydrophilic fibers contained in air-through nonwoven fabrics with a drop count of 9 or more are defined as durable hydrophilic fibers. 【0024】 Durable hydrophilic fibers and general hydrophilic fibers are obtained by treating natural fibers or synthetic fibers with a predetermined hydrophilic treatment agent to impart a predetermined level of hydrophilicity. Here, treatment with a hydrophilic treatment agent includes, for example, a method of adding a hydrophilic treatment agent to a synthetic resin and spinning the synthetic resin; a method of immersing natural fibers or synthetic resins in a hydrophilic treatment solution obtained by dissolving or dispersing a hydrophilic treatment agent in a suitable solvent such as water, an organic solvent, or a mixed solvent of water and an organic solvent for a predetermined time and drying; and a method of applying a hydrophilic treatment agent or a hydrophilic treatment solution obtained by dissolving or dispersing a hydrophilic treatment agent in a suitable solvent such as water, an organic solvent, or a mixed solvent of water and an organic solvent to natural fibers or synthetic resins. Natural fibers are not particularly limited, but examples include cotton fibers and cellulose fibers. Synthetic fibers are not particularly limited, but examples include polyester fibers such as polyester fibers and polyethylene terephthalate (PET) fibers, and polyolefin fibers such as polyethylene fibers and polypropylene fibers. In addition, fibers spun from hydrophilic resins described later may also be used. 【0025】 Examples of hydrophilic treatment agents used for general hydrophilic fibers include anionic surfactants such as sodium lauryl sulfonate and potassium lauryl phosphate. Among these, potassium lauryl phosphate is preferred from the viewpoint of hydrophilicity. Treatment agents used for durable hydrophilic fibers include polyoxyalkylene chain adducts of natural oils such as castor oil and hydrogenated castor oil, or their fatty acid esters, polyoxyethylene stearyl ether, and water-soluble modified silicone. Among these, hydrogenated polyoxyethylene castor oil is preferred from the viewpoint of productivity. 【0026】 The antibacterial fibers included in the second fiber layer 12 are not particularly limited as long as they have antibacterial properties and are suitable as a material for the absorbent article 1, but fibers with antibacterial metal ions supported on the inside and / or surface are preferred. Metal compounds containing metal ions may also be used by supporting them on an inorganic porous body. Examples of support methods include physical adsorption, chemical adsorption, ion exchange, vapor deposition, surface thin film formation, and mechanical support. The antibacterial metal ions are not particularly limited and include, for example, ions such as silver, copper, and zinc. Among these, silver ions, which exhibit antibacterial effects even in trace amounts, are preferred. Examples of inorganic porous bodies include zeolite, hydrotalcite, hydroxyapatite, clay minerals, alumina, silica, and bentonite. Antibacterial organic compounds (antibacterial agents) may also be used. The antibacterial agents are not particularly limited, but examples include hinokitiol, cetylpyridinium chloride, chlorhexidine gluconate, isopropylmethylphenol, benzalkonium chloride, chlorhexidine hydrochloride, benzethonium chloride, and triclosan. Antibacterial metal ions and antibacterial agents can each be used individually or in combination of two or more. Hereinafter, antibacterial metal ions and antibacterial agents may be collectively referred to as antibacterial components. 【0027】 Antibacterial fibers can be produced by methods such as immersing and drying fibers in an antibacterial solution, which is a solution or dispersion containing one or more antibacterial components, to fix the antibacterial components to the fiber surface; applying and drying an antibacterial solution to the fiber surface to fix the antibacterial components to the fiber surface; or adding one or more antibacterial components to a molten synthetic resin and then spinning the synthetic resin. Examples of fibers include cellulose fibers and synthetic fibers. Specific examples of cellulose fibers include natural cellulose fibers such as pulp fibers, cotton fibers, hemp fibers, and kenaf fibers; chemically modified cellulose fibers such as ethylcellulose-containing fibers, hydroxyethylcellulose-containing fibers, hydroxypropylcellulose-containing fibers, methylcellulose-containing fibers, ethylhydroxyethylcellulose-containing fibers, and carboxymethylcellulose-containing fibers; and regenerated cellulose fibers. Examples of synthetic fibers include synthetic fibers spun from hydrophilic resins such as polyacrylamide, polyvinyl alcohol, cross-linked polyvinyl alcohol, chitin, chitosan, ethylene vinyl acetate copolymer, and polyvinyl formal; polyester fibers such as polyester fibers and polyethylene terephthalate (PET) fibers; and polyolefin fibers such as polyethylene fibers and polypropylene fibers. Furthermore, water, organic solvents, and mixed solvents of water and organic solvents can be appropriately selected and used as solvents for the antibacterial solution. 【0028】 The basis weight of the durable hydrophilic fibers in the first fiber layer 11 is, for example, 3 g / m². 2 More than 15g / m 2 The following is preferred: 5 g / m² 2 More than 10g / m 2 From the viewpoint of absorption rate during urination and liquid return, a more preferable value is 7 g / m². 2 More than 9g / m 2 The following applies: The basis weight of the durable hydrophilic fiber is 3 g / m². 2 Smaller particles may result in a slower absorption rate, so 15g / m² is recommended. 2 If the size is larger, there is a risk that the amount of fluid returning to the body will increase. 【0029】 The basis weight of the general hydrophilic fibers in the second fiber layer 12 is not particularly limited, but for example, 7 g / m² 2 More than 25g / m 2 The following is preferable: 12 g / m² 2 More than 21g / m 2 From the perspective of liquid return, a more preferable concentration is 14 g / m². 2 More than 18g / m 2 The following applies: The basis weight of the general hydrophilic fiber is 7 g / m². 2 If the amount is smaller than 25g / m², there is a risk of increased liquid return. 2 If the amount is larger, the antibacterial properties of the top sheet 10 may decrease. The basis weight of the antibacterial fibers in the second fiber layer 12 is, for example, 1 g / m². 2 More than 6g / m 2 The following is preferable: 2 g / m 2 More than 4g / m 2 The following applies: The basis weight of the antibacterial fiber is 1 g / m². 2 Smaller sizes may reduce antibacterial properties, so 6g / m 2 If the metal is larger, the metal ions released by bodily fluids may affect the skin. 【0030】 The overall basis weight of the top sheet 10 is, for example, 15 g / m². 2 More than 40g / m 2 The following is preferable: 19 g / m² 2 More than 35g / m 2 The following applies: The basis weight of Top Sheet 10 is 15 g / m². 2 Smaller sizes may increase the risk of liquid backflow, so 40g / m 2 If it is larger, it tends to become harder when it comes into contact with the skin. There are no particular restrictions on the shape of the top sheet 10, but it should be shaped to cover all or part of the skin-facing side of the absorbent 30, which is necessary to guide bodily fluids to the absorbent 30 to prevent leakage. 【0031】 <Back seat> The backsheet 20 can be formed using a base material that is impermeable to liquid so that the bodily fluids held by the absorbent 30 do not wet the clothing. Examples of such base materials include resin films and composite sheets which are laminates of resin films and nonwoven fabrics. The nonwoven fabric used in the composite sheet is not particularly limited in its manufacturing method and can include single-layer nonwoven fabrics such as spunbond nonwoven fabrics and meltblown nonwoven fabrics, composite nonwoven fabrics such as spunbond nonwoven fabric / meltblown nonwoven fabric laminates and spunbond nonwoven fabric / meltblown nonwoven fabric / spunbond nonwoven fabric laminates, and composite materials thereof. Examples of resin films include polyester, polyvinyl alcohol, polyethylene, polypropylene, and composite films of polyethylene and polypropylene. 【0032】 The basis weight of backsheet 20 is, for example, 15 g / m², considering strength and processability. 2 More than 60g / m 2 The following range applies. Furthermore, to prevent stuffiness during wear, it is preferable that the back sheet 20 be breathable. To provide breathability to the back sheet 20, for example, a filler can be compounded into the resin film of the base material, or the back sheet 20 can be embossed. Calcium carbonate can be used as a filler, and the compounding method can be any known method without limitation. 【0033】 <Absorbent> The absorbent material 30 has a longitudinal dimension (maximum length) that is, for example, in the range of 100 mm to 800 mm, 150 mm to 500 mm, or 270 mm to 500 mm. The width dimension (maximum width) of the absorbent material 30 is, for example, in the range of 50 mm to 500 mm, 60 mm to 400 mm, or 70 mm to 105 mm. Furthermore, if the plan view shape of the absorbent material 30 is hourglass-shaped, the longitudinal dimension is in the range of 180 mm to 480 mm, the width dimensions of the ventral and dorsal parts that come into contact with the wearer's abdomen and back are both in the range of 60 mm to 160 mm, and the width dimension of the crotch part that comes into contact with the wearer's groin is in the range of 50 mm to 140 mm. Embossing may be applied to the entire surface or part of the absorbent material 30. Examples of the planar shape of the absorber 30 include an hourglass shape, an I-shape, a rectangle, a rounded quadrilateral with rounded corners, an oval, and so on. 【0034】 In this embodiment, the absorbent material 30 is interposed between the absorbent material covering sheet 50 and the back sheet 20, and absorbs and retains bodily fluids that have permeated, for example, the top sheet 10, the second sheet 40, and the absorbent material covering sheet 50. The absorbent material 30 contains, for example, absorbent fibers and a superabsorbent polymer (hereinafter also referred to as "SAP") as an absorbent base material. 【0035】 (Absorbent fiber) Absorbent fibers are generally not limited to those used in absorbent articles such as sanitary napkins, disposable diapers, and incontinence pads. Examples include fluff pulp, cotton, rayon, acetate, tissue, absorbent paper, and hydrophilic nonwoven fabrics. Among these, fluff pulp is preferred from the viewpoint of absorbency. Examples of fluff pulp include wood pulp (for example, bleached kraft pulp from coniferous trees such as Southern pine and Douglas fir (N-BKP)), synthetic fibers, resin fibers, and cotton-like defibrated products of non-wood pulp. When fluff pulp is used as the absorbent fiber in the absorbent body 30, the basis weight of the absorbent fiber is, for example, 100 g / m². 2 More than 800g / m 2 The following range or 325g / m² 2 More than 615g / m 2The range is as follows. This allows for the absorption of more bodily fluids without compromising the feel against the skin. 【0036】 (Highly absorbent polymer) There are no particular limitations on the superabsorbent polymer as long as it can absorb bodily fluids and prevent backflow. Examples include polyacrylates, polyaspartates, (starch-acrylic acid) graft copolymers, (acrylic acid-vinyl alcohol) copolymers, (isobutylene-maleic anhydride) copolymers, and their saponifies. Among these, polyacrylates are preferred from the viewpoint of absorption per unit weight, alkali metal polyacrylates are more preferred, and sodium polyacrylate is even more preferred. The superabsorbent polymer can be used alone or in combination of two or more. 【0037】 Superabsorbent polymers are used in various forms, such as particulate or fibrous, but are preferably used in particulate form for ease of handling. In this case, by avoiding the use of superabsorbent polymers in the form of fine powder, which have poor fluidity as a powder, and instead using superabsorbent polymers with a medium particle size, the basic performance related to absorption can be improved, and the rough texture caused by the hardening of the absorbent material 30 can be reduced. The medium particle size of the superabsorbent polymer is, for example, in the range of 50 μm to 600 μm or 100 μm to 500 μm. 【0038】 The basis weight of SAP in absorbent material 30 is, for example, 240 g / m². 2 More than 450g / m 2 The following ranges, or 245g / m² 2 More than 445g / m 2 The following range applies. By keeping the basis weight of the SAP within the aforementioned numerical range, gel blocking in the absorbent material 30 can be prevented, and a large amount of bodily fluids can be absorbed by the absorbent material 30. Furthermore, in the absorbent material 30, the ratio of the weight of the superabsorbent polymer to the total weight of the absorbent material 30, i.e., weight of superabsorbent polymer / total weight of absorbent material 30 × 100 (%), is, for example, in the range of 40% by weight or more, or in the range of 40% by weight or more and 70% by weight or less. 【0039】 In the absorbent body 30, the form of the absorbent fibers and SAP may be one in which SAP particles are mixed into absorbent fibers, or it may be an SAP sheet in which SAP particles are fixed between absorbent fibers. Furthermore, a carrier sheet (not shown) may be provided below the absorbent body 30 for the purpose of preventing leakage of SAP particles and stabilizing the shape of the absorbent body 30. The base material of the carrier sheet may be any material that is hydrophilic, and examples include hydrophilic nonwoven fabrics such as tissue, absorbent paper, and airlaid nonwoven fabric. If multiple carrier sheets are provided, the base materials of the multiple carrier sheets may be the same or different. 【0040】 <Second row seats> As shown in Figure 2, the second sheet 40 is positioned between the top sheet 10 and the absorbent covering sheet 50, and for example, improves the liquid diffusion of the absorbent article 1 and suppresses the return of bodily fluids from the absorbent 30. The second sheet 40 can be any liquid-diffusive substrate that has a faster permeability of bodily fluids than the top sheet 10 and allows for rapid diffusion of bodily fluids into the absorbent 30. Examples of such substrates include hydrophilic nonwoven fabrics, and among these, air-through nonwoven fabrics are preferred. 【0041】 The second sheet 40 has a thickness of, for example, 0.1 mm or more, and a basis weight of, for example, 10 g / m². 2 More than 60g / m 2 The following ranges, or 15g / m² 2 More than 40g / m 2 The following ranges apply: Thickness less than 0.1 mm, or basis weight 10 g / m². 2 Less than 60g / m² 2 If the size is larger, the body fluids tend not to spread sufficiently across the entire skin surface of the absorbent material 30. Also, although there are no particular restrictions on the shape of the second sheet 40, it is preferable that it be shaped in such a way that it can completely cover the surface of the absorbent material 30 so that the body fluids spread evenly across the absorbent material 30. 【0042】 The ratio of the basis weight of the top sheet 10 to the second sheet 40 (percentage, basis weight of second sheet 40 / basis weight of top sheet 10) is preferably 50% to 130%, more preferably 50% to 100%. By setting the basis weight ratio to 50% to 130%, the liquid diffusion and liquid permeability when liquid permeates from the top sheet 10 to the second sheet 40 are improved, and liquid is less likely to flow back from the second sheet 40 to the top sheet 10. 【0043】 <Absorbent covering sheet> As shown in Figure 2, the absorbent covering sheet 50 is positioned between the second sheet 40 and the absorbent 30. The base material of the absorbent covering sheet 50 can be any hydrophilic material, and tissue containing pulp or absorbent paper is particularly preferred, but a hydrophilic nonwoven fabric such as airlaid nonwoven fabric may also be used. 【0044】 <3D Gathering> The three-dimensional gathers 60 are fixed to the skin-facing side of the top sheet 10 along the longitudinal direction of the absorbent article 1 near both ends in the width direction of the absorbent article 1, for example, to prevent lateral leakage of bodily fluids excreted by the wearer of the absorbent article 1. The three-dimensional gathers 60 include an elastic stretchable member 60a and a water-repellent and / or waterproof sheet member 60b. 【0045】 The elastic stretchable member 60a is arranged along the longitudinal direction near the free end (other end) of the sheet member 60b, providing the free end with uprightness and allowing the free end and its vicinity to deform to conform to the wearer's body shape. In this embodiment, one end (fixed end) of the sheet member 60b in the width direction is fixed near both ends in the width direction of the skin-facing side of the back sheet 20, a portion in the width direction is fixed near both ends in the width direction of the skin-facing side of the top sheet 10, and the other end in the width direction is an upright free end. The fixing position of the fixed end (one end in the width direction) of the sheet member 60b is not limited to this embodiment, and examples include the non-skin-facing side of the back sheet 20, near both ends in the width direction of the skin-facing or non-skin-facing side of the joint between all or part of the edges of the top sheet 10 containing the absorbent material 30 and the back sheet 20, and near both ends in the width direction of the skin-facing side of the top sheet 10. 【0046】 The sheet member 60b is a water-repellent and / or waterproof sheet, and is made of, for example, a nonwoven fabric. The nonwoven fabric for the first sheet member can be any water-repellent and / or waterproof (liquid-impermeable) nonwoven fabric formed from hydrophobic fibers, without any particular limitations. Examples include spunbond nonwoven fabric, meltblown nonwoven fabric, and composite nonwoven fabric (SMS nonwoven fabric) which is a laminate of spunbond nonwoven fabric / meltblown nonwoven fabric / spunbond nonwoven fabric. The basis weight of the sheet member 60b is, for example, 13 g / m². 2 More than 20g / m 2 The range is as follows. As the elastic stretchable member 60a, thread-like, string-like, or strip-like materials made of natural rubber, synthetic rubber, polyurethane, etc., can be used as appropriate. 【0047】 <Method for manufacturing absorbent articles> The absorbent article 1 can be manufactured by known manufacturing methods, but for example, a manufacturing method may include the steps of: overlapping a top sheet 10, a second sheet 40, an absorbent covering sheet 40, an absorbent 30, and a back sheet 20 in the thickness direction, and placing the absorbent 30 between the top sheet 10 and the back sheet 20; fixing the edges of the top sheet 10 and the back sheet 20 to part or all of their circumference using hot melt adhesive, heat embossing, ultrasonic embossing, high-frequency embossing, etc.; and installing three-dimensional gathers 60 at predetermined positions on the back sheet 20 and the top sheet 10. If the absorbent article 1 is a urine pad or a light incontinence pad, it can be individually packaged in a packaging body and then folded into thirds in the longitudinal direction. Depending on the use and form of the absorbent article 1, leg gathers, waist gathers, side flaps, etc. may be provided as appropriate. 【0048】 Although the present invention has been described above using embodiments, it goes without saying that the technical scope of the present invention is not limited to the scope described in the above embodiments and examples. It will be obvious to those skilled in the art that various modifications or improvements can be made to the above embodiments. Furthermore, it is clear from the claims that such modified or improved forms may also be included in the technical scope of the present invention. [Examples] 【0049】 The present invention will be described in detail below with reference to examples. However, the present invention is not limited in any way to the examples shown below. 【0050】 (Production of general hydrophilic fibers and water-resistant hydrophilic fibers) A 2.0% by weight aqueous solution of potassium lauryl phosphate (hydrophilization solution A) was prepared. Polyethylene fibers were immersed in this hydrophilization solution A for 60 minutes at room temperature, and then dried with hot air at 120°C to produce general hydrophilic fibers that required 4 drops in the hydrophilicity test described above. In addition, a 1.0% by weight aqueous solution of polyoxyethylene stearyl ether (hydrophilization solution B) was prepared. Polyethylene fibers were immersed in this hydrophilization solution B for 60 minutes at room temperature, and then dried with hot air at 120°C to produce durable hydrophilic fibers that required 9 drops in the hydrophilicity test described above. 【0051】 (Production of antibacterial fibers) Polyethylene fibers were immersed in a 4.0 wt% aqueous solution of sodium metasilicate. A fixed amount of a 3.0 wt% aqueous solution of sodium aluminate and a silver ion-supported zeolite were then added, and the mixture was immersed at 90°C for 3 hours to produce silver ion-supported zeolite-supported polyethylene fibers. The silver ion load of the obtained polyethylene fibers was 0.002 wt%. 【0052】 (Creating the top sheet) Using the general hydrophilic fibers (fiber thickness 2.6 dtex, fiber length 50 mm), durable hydrophilic fibers (fiber thickness 2.0 dtex, fiber length 51 mm), and antibacterial fibers (fiber thickness 2.2 dtex, fiber length 51 mm) obtained above, a two-layer air-through nonwoven fabric was prepared, with durable hydrophilic fibers in the first fiber layer and general hydrophilic fibers and antibacterial fibers in the second fiber layer, and this was used as the top sheet. Its composition is shown in Table 1. 【0053】 (Preparation of medical supplies) The absorbent material is formed by mixing 6g of SAP into 7g of the base material, which is fluff pulp, and the top sheet is the two-layer type air-through nonwoven fabric obtained above (basis weight 25g / m²). 2 ), and a breathable polyethylene sheet (basis weight 32g / m²) as a liquid-impermeable backsheet. 2 ), as a second seat, air-through nonwoven fabric (basis weight 30g / m²) 2 ), and composite nonwoven fabrics (basis weight 15g / m²) which are laminates of spunbond nonwoven fabric / meltblown nonwoven fabric / spunbond nonwoven fabric as three-dimensional gathers. 2 ), upper and lower carrier sheets made of tissue (basis weight 15g / m²) 2 Using the above materials, absorbent articles for Examples 1-5 and Comparative Examples 1-3 were prepared, with the dimensions of the absorbent body being 220 mm in the longitudinal direction and 70 mm in width, and the dimensions of the absorbent article being 270 mm in the longitudinal direction and 105 mm in width. 【0054】 The following evaluation tests were conducted on the absorbent articles of Examples 1-5 and Comparative Examples 1-3. The results are shown in Table 1. (Absorption rate) Bottom area 16.8cm 2 A measuring jig with a cylindrical shape, a hole with an inner diameter of 19 mm in the center, and a weight of 755.6 g, was placed on the center of the absorbent material in both its longitudinal and width directions. 20 ml of physiological saline solution was dropped from the hole at the top, and the time (in seconds) was measured from the moment the physiological saline solution came into contact with the absorbent material until the liquid was completely absorbed into the circumference of the central circle of the jig. (Liquid return property) With the top sheet facing upwards, 120 ml of physiological saline was poured towards the center of the absorbent material. After standing for 10 minutes, a filter paper (ADVANTEC No. 2 filter paper, 55 mm in diameter) whose weight had been measured in advance was placed on the absorption site of the physiological saline. A weight of 35 kgf / cm2 was then placed on top of the filter paper, and after 30 seconds, the weight of the filter paper was measured. The difference in the weight of the filter paper was defined as the amount of liquid return (g), and the liquid return performance was evaluated. A smaller amount of liquid return indicates better liquid return performance. (antibacterial) Antibacterial properties were assessed using the top sheet, following the JIS L 1902 method. Products with an antibacterial activity value of 3 or higher, based on the results of a standard cloth (cotton cloth) for Staphylococcus aureus, were marked with ○, those with a value of 2 or higher but less than 3 were marked with △, and those with a value less than 2 were marked with ×. 【0055】 [Table 1] 【0056】 The results in Table 1 show that the absorbent articles of Examples 1-5 exhibit excellent absorption rate, liquid return, and antibacterial properties. On the other hand, the antibacterial fiber was 3 g / m 2 Although the absorbent article of Comparative Example 1 showed good antibacterial properties, its liquid return and water absorption rate were significantly inferior to those of the absorbent articles of Examples 1 to 5. Furthermore, the absorbent article of Comparative Example 2, in which the second fiber layer consisted solely of antibacterial fibers, had poor antibacterial properties and a slow absorption rate. Moreover, the absorbent article of Comparative Example 3 showed no antibacterial properties. Therefore, according to the present invention, it is possible to provide an absorbent article that has excellent liquid permeability, excellent return properties of body fluids, and excellent antibacterial properties even when body fluids remain on the top sheet. [Explanation of symbols] 【0057】 1. Absorbent articles 10 Top Sheets 11. First fiber layer 12. Second fiber layer 20 Backseat 30 absorbent material 40 Second row seats 50 Absorbent covering sheets 60 Three-dimensional gathers

Claims

[Claim 1] An absorbent article comprising a liquid-permeable top sheet, a liquid-impermeable back sheet, and an absorbent disposed between the top sheet and the back sheet, The top sheet comprises a first fiber layer made of durable hydrophilic fibers, and a second fiber layer adjacent to the non-skin contact surface of the first fiber layer, made of general hydrophilic fibers and antibacterial fibers, wherein the first fiber layer and the second fiber layer are overlapped in the thickness direction, the skin contact surface of the first fiber layer constitutes the skin contact surface of the top sheet, and the non-skin contact surface of the second fiber layer constitutes the non-skin contact surface of the top sheet. The aforementioned top sheet is an air-through nonwoven fabric, The basis weight of the durable hydrophilic fibers in the first fiber layer is 5 g / m². ２ 15g / m or more ２ The basis weight of the general hydrophilic fibers in the second fiber layer is 7 g / m². ２ 21g / m or more ２ The following applies, and the basis weight of the antibacterial fiber is 2 g / m². ２ 4g / m or more ２ The absorbent article is as follows, characterized in that the antibacterial fibers are not included in the first fiber layer. However, the above general hydrophilic fiber and the above durable hydrophilic fiber shall have a basis weight of 20 g / m² including the hydrophilic fiber. ２ Hydrophilicity is defined by a hydrophilicity evaluation that is observed when 100 μL of 0.9% saline solution is dropped onto the same position on the air-through nonwoven fabric every 30 seconds, and the number of drops at which the dropped saline solution does not penetrate the air-through nonwoven fabric but forms droplets on the air-through nonwoven fabric is observed. Hydrophilic fibers contained in the air-through nonwoven fabric with a hydrophilicity evaluation of 1 to 8 times are defined as general hydrophilic fibers, and hydrophilic fibers contained in the air-through nonwoven fabric with a hydrophilicity evaluation of 9 or more times are defined as durable hydrophilic fibers. [Claim 2] The basis weight of the topsheet is 15 g / m ２ or more and 40 g / m ２ or less, and the absorbent article according to claim 1, characterized in that. [Claim 3] A liquid-diffusive second sheet is placed between the top sheet and the absorbent, The absorbent article according to claim 1 or claim 2, characterized in that the second sheet is made of an air-through nonwoven fabric. [Claim 4] The absorbent article according to any one of claims 1 to 3, further comprising an absorbent covering sheet disposed between the absorbent and the top sheet, wherein the absorbent covering sheet contains pulp fibers. [Claim 5] The absorbent article according to claim 3, characterized in that the ratio of the basis weight of the top sheet to the second sheet is 50% or more and 130% or less.