Absorbent article

Abstract

To provide an absorbent article whose absorption rate does not lower especially during repetitive absorption, which has only a small amount of liquid return, is excellent in liquid diffusibility, and has excellent absorbency and wear feeling.SOLUTION: An absorbent article is provided with a liquid permeable top sheet, a liquid impermeable back sheet and an absorber. The absorber has a high absorbent sheet and a hydrophilic sheet. The high absorbent sheet has a continuous porous body sheet, a composite type unwoven fabric sheet, and a high absorbent polymer. The high absorbent polymer includes: a first high absorbent polymer sealed between layers of a first continuous porous body sheet and a second continuous porous body sheet; and a second high absorbent polymer sealed between layers of the second continuous porous body sheet and a composite type nonwoven fabric sheet. Absorption rate of the first high absorbent polymer is below 40 g / g and liquid-passing speed is 30 ml / minute or more; absorption rate of the second high absorbent polymer is 40 g / g or more and the liquid-passing speed is 10 ml / minute or less.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to an absorber and an absorbent article provided with the absorber.

Background Art

[0002] Generally, an absorbent article is composed of a liquid-permeable topsheet, a liquid-impermeable backsheet, and an absorber disposed between the topsheet and the backsheet.

[0003] In recent years, products that are not conspicuous when wearing absorbent articles, have no discomfort when worn, and give no feeling of wearing them have been desired. Therefore, many aspects of absorbent articles with a thinner absorber, which occupies most of the absorbent articles, have been proposed.

[0004] As such an absorbent article, for example, Patent Document 1 discloses an absorbent article in which a second sheet is disposed between a surface sheet and an absorber, and the absorber has a density higher than 0.12 g / cm 3 and the second sheet has a capillary force of 1.5×10 3 N or more. By optimizing the density of the absorber and the capillary force of the second sheet, it is possible to achieve both a thin absorber and excellent absorbency at a high level, and to provide a sense of security and a comfortable wearing feeling when worn. Further, Patent Document 2 discloses an absorbent article having an upper absorbent layer composed of a nonwoven fabric and an absorbent polymer, and a lower absorbent layer composed of a hydrophilic porous body and an absorbent polymer. The lower absorbent layer is substantially vertically long, and the central portion in the width direction of the lower absorbent layer has a smaller distribution amount of the absorbent polymer than other portions of the lower absorbent layer. By using a hydrophilic porous material in the lower absorbent layer and optimizing the distribution of the absorbent polymer, it is possible to maintain high liquid diffusibility and liquid retention while having a thin thickness and a high absorption rate.

[0005] On the one hand, as an absorber using a urethane foam, Patent Document 3 discloses an absorber having a base material layer with a first surface and a second surface, an absorbent polymer material layer with a first surface and a second surface, and an adhesive layer with a first surface and a second surface. The absorbent polymer material layer is included between the adhesive layer and the base material layer. The second surface of the absorbent polymer material layer contacts the first surface of the base material layer, and the first surface of the absorbent polymer material layer contacts the second surface of the adhesive layer. The base material layer includes an absorbent core provided with a foam material layer. By incorporating a foam layer having an absorbent gel material into a layer stably attached on the base material layer, it is described that the fit is good and comfortable, and the utilization rate of the core absorption capacity can be maintained. Further, Patent Document 4 discloses a laminate composed of one or more plastic foam layers and / or latex foam layers and particulate superabsorbent polymers for absorbing water and aqueous liquids. The superabsorbent polymer is configured in a planar arrangement that is predetermined and fixed quantitatively and / or spatially directly on, between, or under the foam plastic and / or foam latex layers. Also disclosed is a laminate in which the quantitative ratio of the foam plastic and / or foam latex layer to the superabsorbent polymer is 1:500 to 50:1, preferably 1:50 to 25:1, and most preferably 1:5 to 10:1. It is described that the absorption capacity for water and aqueous liquids is enhanced, especially under load.

Prior Art Documents

Patent Documents

[0006]

Patent Document 1

Patent Document 2

Patent Document 3

Patent Document 4

Summary of the Invention

Problems to be Solved by the Invention

[0007] However, when thinning and lightening the absorbent article in the above-described manner, a certain degree of absorption performance must be sacrificed. In particular, sufficient absorption performance cannot be maintained in products for incontinent use and urine collection pads with a narrow absorption surface area. Also, both the absorption speed and the small amount of liquid return (backflow) are important as indicators of absorption performance, but it is difficult to satisfy both at a high level in a thin absorbent article.

[0008] The present invention has been made in view of such circumstances, and an object thereof is to provide an absorbent article having excellent absorbency and wearing comfort, in which the absorption speed does not decrease particularly during repeated absorption, the amount of liquid return is small, and the diffusion of body fluid is excellent.

Means for Solving the Problems

[0009] The present inventors have conducted intensive studies and provided a highly absorbent sheet containing a highly absorbent polymer between layers of a composite nonwoven fabric sheet in which a continuous porous polyurethane sheet and a pulp fiber web are laminated and integrated on a spunbond nonwoven fabric. By adopting two types of highly absorbent polymer particles having specific absorption ratios and liquid permeability rates, it has been found that an absorbent article having excellent absorbency and wearing comfort, in which the absorption speed does not decrease particularly during repeated absorption, the amount of liquid return is small, and the diffusion of body fluid is excellent, can be obtained, and the above problems can be solved, leading to the completion of the present invention. Specifically, the present invention provides the following.

[0010] (1) The first aspect of the present invention is an absorbent article comprising a liquid-permeable top sheet, a liquid-impermeable back sheet, and an absorber containing no fluff pulp between the top sheet and the back sheet, wherein the absorber has a superabsorbent sheet and a hydrophilic sheet wrapping the entire superabsorbent sheet. The superabsorbent sheet has a continuous porous body sheet made of polyurethane, a composite nonwoven fabric sheet formed by laminating and integrating a pulp fiber web on a spunbond nonwoven fabric, and a superabsorbent polymer encapsulated between the layers of each sheet. The superabsorbent sheet is laminated in the order of a first continuous porous body sheet, a second continuous porous body sheet, and the composite nonwoven fabric sheet from the skin contact surface side of the wearer. The superabsorbent polymer includes a first superabsorbent polymer encapsulated between the layers of the first continuous porous body sheet and the second continuous porous body sheet, and a second superabsorbent polymer encapsulated between the layers of the second continuous porous body sheet and the composite nonwoven fabric sheet. The absorption capacity of the first superabsorbent polymer is less than 40 g / g and the liquid permeability rate is 30 ml / min or more, and the absorption capacity of the second superabsorbent polymer is 40 g / g or more and the liquid permeability rate is 10 ml / min or less. It is an absorbent article characterized by this. (2) The second aspect of the present invention is the absorbent article according to (1), wherein the continuous porous body sheet has a basis weight of 30 g / m 2 or more and 300 g / m 2 or less, and an apparent density of 100 kg / m 3 or more and 200 kg / m 3 or less. (3) The third aspect of the present invention is the absorbent article according to (1) or (2), wherein the continuous porous body sheet has a hydrophilic skeleton surface. (4) The fourth aspect of the present invention is the absorbent article according to any one of (1) to (3), wherein the strength in the tensile test of the composite nonwoven fabric sheet is such that the force required to stretch a test piece formed to a width of 25 mm in the longitudinal direction by 2 mm in a test with a tensilon is 1.5 N / 25 mm or more and 5.0 N / 25 mm or less. (5) The fifth aspect of the present invention is the absorbent article according to any one of (1) to (4), wherein the material of the spunbond nonwoven fabric is selected from one or a combination of two or more from the group consisting of nylon, vinylon, polyester, acrylic, polyethylene, polypropylene, and polystyrene. (6) The sixth aspect of the present invention is the absorbent article according to any one of (1) to (5), wherein in the hydroentangling step of hydroentangling the spunbond nonwoven fabric and the pulp fiber web, the hole diameter Φ of the water jet nozzle for injecting the water jet is 0.06 mm or more and 0.15 mm or less, and the interval between the water jet nozzles is 0.4 mm or more and 1.0 mm or less. (7) The seventh aspect of the present invention is the absorbent article according to (6), wherein the surface of the composite nonwoven fabric sheet in contact with the second superabsorbent polymer is the surface that is hit by the water jet and hydroentangled. (8) The eighth aspect of the present invention is the absorbent article according to any one of (1) to (7), wherein the ratio (2A / 1A) of the absorption capacity (2A) of the second superabsorbent polymer to the absorption capacity (1A) of the first superabsorbent polymer is 1.2 or more. (9) The ninth aspect of the present invention is the absorbent article according to any one of (1) to (8), wherein the ratio (1S / 2S) of the liquid permeability rate (1S) of the first superabsorbent polymer to the liquid permeability rate (2S) of the second superabsorbent polymer is 5 or more. (10) The tenth aspect of the present invention is the absorbent article according to any one of (1) to (9), wherein the basis weight of the superabsorbent polymer is 30 g / m 2 or more and 300 g / m 2 or less.

Advantages of the Invention

[0011] According to the present invention, it is possible to provide an absorbent article having excellent absorbency and wearing comfort, which does not exhibit a decrease in absorption rate, has a small amount of liquid return, and is excellent in the diffusion of body fluid, especially during repeated absorption.

Brief Description of the Drawings

[0012]

Figure 1

Figure 2

Figure 3

Modes for Carrying Out the Invention

[0013] Hereinafter, embodiments for carrying out the present invention (hereinafter referred to as embodiments) will be described in detail with reference to the drawings. However, these are presented for illustrative purposes and do not limit the present invention. The same reference numerals are assigned to the same elements throughout the description of the embodiments.

[0014] In addition, in the description of this specification, the time of wearing the absorbent article 1 means at least one of the time of wearing and after wearing the absorbent article 1. The longitudinal direction of the absorbent article 1 is the direction extending across the front and back of the wearer when the absorbent article 1 is worn, and is the direction indicated by the symbol X in the figure. The width direction of the absorbent article 1 is a direction horizontal or orthogonal to the longitudinal direction, and is the direction indicated by the symbol Y in the figure. Further, the skin-contact surface is the surface of each member such as the absorber that is arranged on the skin side of the wearer during wearing, and the non-skin-contact surface is the surface of each member such as the absorber that is directed to the side opposite to the skin side of the wearer during wearing. Body fluid means a liquid discharged from the body to the outside, such as urine, blood, and moisture in soft feces. Further, examples of the absorbent article 1 include, but are not limited to, incontinent products and urine pads, and other absorbent articles may also be used.

[0015] <Absorbent Article> FIG. 1 is a plan view of the absorbent article 1 according to an embodiment of the present invention as viewed from the topsheet 10 side, and FIG. 2 is a cross-sectional view taken along the Y 1 -Y 1 line. The absorbent article 1 of the present invention includes a liquid-permeable topsheet 10, a liquid-impermeable backsheet 20, and an absorber 30 that does not contain fluff pulp between the topsheet 10 and the backsheet 20. Note that the absorbent article 1 preferably has a longitudinal dimension of 100 mm or more and 800 mm or less, and a width dimension of 50 mm or more and 500 mm or less. By adjusting each dimension of the absorbent article 1 within the above range, an absorbent article 1 suitable for a loss prevention product, a urine collection pad, etc. can be obtained.

[0016] In addition, in order to prevent lateral leakage of the body fluid excreted by the wearer, as shown in FIGS. 1 and 2, along the longitudinal direction of the absorbent article 1, a pair of three-dimensional gathers 50 having elastic members for three-dimensional gathers are provided on the topsheet 10. The outer ends of the three-dimensional gathers 50 in the width direction of the absorbent article 1 are fixed to the backsheet 20, the inner ends thereof are fixed to the topsheet 10, and the center thereof is arranged as a free end not fixed to the topsheet 10 so that a three-dimensional gather sheet is arranged. By providing the elastic member for three-dimensional gathers along the longitudinal direction, the three-dimensional gathers 50 have standing properties and can be deformed according to the body shape of the wearer. As the elastic member for three-dimensional gathers, for example, a thermal bond nonwoven fabric, a spunbond nonwoven fabric, a polyethylene film, or a sheet obtained by combining and joining those sheets can be used. From the viewpoints of strength and processability, the basis weight of the three-dimensional gathers 50 is preferably 10 g / m 2 or more and 30 g / m 2 or less.

[0017] <Topsheet> The topsheet 10 may be formed from a base material having liquid permeability such that body fluid can move to the absorber 30. For example, known hydrophilic nonwoven fabrics such as thermal bond nonwoven fabric and spunbond nonwoven fabric can be used. Further, in order to improve the liquid permeability, the topsheet 10 may be embossed or perforated on the surface. As methods for performing these embossing and perforating processes, known methods can be implemented without limitation. Further, in order to reduce irritation to the skin, the topsheet 10 may contain lotion, antioxidant, anti-inflammatory component, pH adjuster, antibacterial agent, moisturizing agent, etc. In terms of strength, processability, and rewet amount, the basis weight of the topsheet 10 is 18 g / m 2 or more and 400 g / m 2 or less, preferably 20 g / m 2 or more and 100 g / m 2 or less, more preferably. The shape of the topsheet 10 is not particularly limited, but it may be a shape that covers the absorber 30, which is necessary to guide body fluid to the absorber 30 so that there is no leakage.

[0018] <Backsheet> The backsheet 20 may be formed using a base material having liquid impermeability such that the body fluid held by the absorber 30 does not wet the clothing, and an air-permeable or non-air-permeable liquid-impermeable plastic film can be used.

[0019] In terms of strength and processability, the basis weight of the backsheet 20 is 12 g / m 2 or more and 40 g / m 2 or less, preferably 15 g / m 2 or more and 35 g / m 2 or less, more preferably. In order to make the backsheet 20 air-permeable, for example, a filler may be blended into the resin film of the base material, or the backsheet 20 may be embossed. Examples of the filler include calcium carbonate, and the blending method can be performed using known methods without limitation.

[0020] <Absorber> In the absorbent article 1 of the present invention, the longitudinal dimension of the absorber 30 is preferably 50 mm or more and 750 mm or less, and more preferably 80 mm or more and 700 mm or less. Further, the widthwise dimension of the absorber 30 is preferably 20 mm or more and 450 mm or less, and more preferably 30 mm or more and 400 mm or less. Note that, as described above, the absorber 30 does not contain fluff pulp. This is because fluff pulp has a large bulk and is not suitable for thinning the absorber 30.

[0021] (High-absorbency sheet) As shown in FIG. 2, the absorber 30 has a high-absorbency sheet 60 and a hydrophilic sheet 70 that wraps the entire high-absorbency sheet 60. Among these, the high-absorbency sheet 60 has a continuous porous sheet 80 made of polyurethane, a composite nonwoven fabric sheet 90 obtained by laminating and integrating a pulp fiber web on a spunbond nonwoven fabric, and a superabsorbent polymer (hereinafter also referred to as SAP) 100 encapsulated between the layers of each sheet.

[0022] More specifically, as shown in the enlarged view of FIG. 3, the high-absorbency sheet 60 is laminated in the order of a first continuous porous sheet 81, a second continuous porous sheet 82, and a composite nonwoven fabric sheet 90 from the side in contact with the wearer's skin. Among these, for both the first continuous porous sheet 81 and the second continuous porous sheet 82, a single-layer sheet of a known urethane foam or the like can be used. Further, the basis weight of both is 30 g / m 2 300 g / m or more 2 and 200 kg / m or less, and it is preferable that the apparent density of both is 100 kg / m 3 200 kg / m or more 3 and 200 kg / m or less. Further, it is preferable that the surface of the skeleton of the first continuous porous sheet 81 and the second continuous porous sheet 82 is hydrophilic.

[0023] In the composite nonwoven fabric sheet 90, the basis weight of the spunbond nonwoven fabric is 7 g / m 2 20 g / m or more 2It is preferably as follows, and the basis weight of the pulp fiber web is 30 g / m 2 or more and 70 g / m 2 or less. Further, the weight composition ratio of the spunbond nonwoven fabric and the pulp fiber web is preferably 10 / 90 wt% or more and 40 / 60 wt% or less. In addition, in the tensile test of the composite nonwoven fabric sheet 90, in the test with a tensilon, the force required to stretch the test piece formed to a width of 25 mm by 2 mm in the longitudinal direction is preferably 1.5 N / 25 mm or more and 5.0 N / 25 mm or less.

[0024] The material of the spunbond nonwoven fabric is preferably selected from one or a combination of two or more of the group consisting of nylon, vinylon, polyester, acrylic, polyethylene, polypropylene, and polystyrene. Among them, polypropylene is more preferable.

[0025] When laminating and integrating the pulp fiber web on the spunbond nonwoven fabric, it passes through a water entanglement process of water entanglement treatment of the spunbond nonwoven fabric and the pulp fiber web. In this process, the hole diameter Φ of the water jet nozzle for injecting the water jet is 0.06 mm or more and 0.15 mm or less, and the interval between the water jet nozzles is preferably 0.4 mm or more and 1.0 mm or less. Further, the surface of the composite nonwoven fabric sheet 90 in contact with the second superabsorbent polymer 102 described later is preferably the surface where the water jet hits and is water-entangled.

[0026] The continuous porous sheet 80 made of polyurethane hardly feels the hardness of the superabsorbent polymer 100 described later when worn. Further, in the composite nonwoven fabric sheet 90, the uneven surface formed by the water jet on the water entanglement surface is in contact with the second superabsorbent polymer 102, and further, the superabsorbent polymer 100 is arranged in the space formed in a block shape, so that the displacement and movement of the superabsorbent polymer 100 are suppressed, and the thickness and touch can be kept more uniform in the longitudinal and width directions even after absorbing body fluids. Therefore, the wearing feeling of the absorbent article 1 is improved.

[0027] (Superabsorbent Polymer) The superabsorbent polymer 100 includes a first superabsorbent polymer 101 encapsulated between the first continuous porous sheet 81 and the second continuous porous sheet 82, and a second superabsorbent polymer 102 encapsulated between the second continuous porous sheet 82 and the composite nonwoven sheet 90. At this time, the first superabsorbent polymer 101 and the second superabsorbent polymer 102 are those with different absorption rates and liquid permeability rates. Specifically, it is preferable to use a high liquid permeability type with a high liquid permeability rate for the first superabsorbent polymer 101, and a high absorption type with a high absorption rate for the second superabsorbent polymer 102. More specifically, expressed as numerical values, the absorption rate of the first superabsorbent polymer 101 is less than 40 g / g and the liquid permeability rate is 30 ml / min or more, and the absorption rate of the second superabsorbent polymer 102 is 40 g / g or more and the liquid permeability rate is 10 ml / min or less. By arranging SAPs with different properties on the skin-contact side and the non-skin-contact side, particularly by setting the first superabsorbent polymer 101 on the skin-contact side to the high liquid permeability type and the second superabsorbent polymer 102 on the non-skin-contact side to the high absorption type, the absorbent article 1 can be obtained, which can direct the absorption of body fluids from the thickness direction to the longitudinal and width direction flows, and increase the absorption amount while improving the diffusibility.

[0028] In addition, the absorption rate of the first superabsorbent polymer 101 is preferably 20 g / g or more and 38 g / g or less, and the liquid permeability rate is preferably 30 ml / min or more and 50 ml / min or less. Also, the absorption rate of the second superabsorbent polymer 102 is preferably 42 g / g or more and 80 g / g or less, and the liquid permeability rate is preferably 2 ml / min or more and 10 ml / min or less.

[0029] The absorption rate of the superabsorbent polymer 100 mentioned here refers to the absorption rate (unit: g / g) after the superabsorbent polymer 100 (the first superabsorbent polymer 101 and the second superabsorbent polymer 102) is immersed in a large excess of 0.9 mass% sodium chloride aqueous solution under no pressure for 30 minutes for free swelling, and then dehydrated at 150G using a centrifuge. The liquid permeability rate of the superabsorbent polymer 100 is the liquid permeability rate (unit: ml / min) of a 0.9 mass% sodium chloride aqueous solution passing between gels of the superabsorbent polymer 100 (the first superabsorbent polymer 101 and the second superabsorbent polymer 102) swollen in a large excess of 0.9 mass% sodium chloride aqueous solution in advance under a pressure of 0.3 psi. More specifically, the method for measuring the liquid permeability rate can be measured in accordance with paragraph

[0037] of JP-A-2017-070497.

[0030] Also, the ratio (2A / 1A) of the absorption capacity (2A) of the second superabsorbent polymer 102 to the absorption capacity (1A) of the first superabsorbent polymer 101 is preferably 1.2 or more, and the ratio (1S / 2S) of the liquid permeability rate (1S) of the first superabsorbent polymer 101 to the liquid permeability rate (2S) of the second superabsorbent polymer 102 is preferably 5 or more. By setting each ratio within the above numerical range, the diffusibility of body fluids can be further improved. Note that the ratio (2A / 1A) is more preferably 1.4 or more and 2 or less, and the ratio (1S / 2S) is more preferably 5.5 or more and 10 or less.

[0031] The superabsorbent polymer 100 is not particularly limited as long as it can absorb body fluids and prevent liquid return, and materials formed from materials such as sodium polyacrylate-based, polyaspartate-based, (starch-acrylic acid) graft copolymers, (acrylic acid-vinyl alcohol) copolymers, (isobutylene-maleic anhydride) copolymers and their saponified products can be used. Among these, from the viewpoints of absorption capacity and liquid permeability rate, the first superabsorbent polymer 101 is preferably sodium polyacrylate-based, and the second superabsorbent polymer 102 is preferably sodium polyacrylate-based. Also, the basis weight of the superabsorbent polymer 100 is preferably 30 g / m 2 300 g / m or more 2 and preferably 300 g / m or less.

[0032] (Hydrophilic sheet) The hydrophilic sheet 70 may be formed from a base material having liquid permeability such that body fluid moves to the absorber 30, similar to the top sheet 10. For example, known hydrophilic non-woven fabrics such as thermal-bonded non-woven fabric and spun-bonded non-woven fabric can be used. In terms of strength, processability, and liquid return amount, the basis weight of the hydrophilic sheet 70 is 10 g / m 2 or more and 50 g / m 2 or less, preferably, and more preferably 12 g / m 2 or more and 30 g / m 2 or less. The shape of the hydrophilic sheet 70 is not particularly limited, but it may be a shape that covers the entire absorber 30, which is necessary to guide the absorbed body fluid to the absorber 30 without leakage and prevent the absorber 30 from falling out of the gap.

[0033] (Joint portion) As shown in FIGS. 1 and 2, in the absorbent article 1 of the present invention, the first continuous porous body sheet 81, the second continuous porous body sheet 82, and the second continuous porous body sheet 82 and the composite non-woven fabric sheet 90 are preferably joined to each other at the joint portion 40 partially. By partially joining between the sheets at the joint portion 40 and forming a space containing the superabsorbent polymer 100 in a block shape between the sheets, an absorbent body 30 with excellent absorption performance and wearing comfort, in which the absorption rate does not decrease during repeated absorption and the diffusion of body fluid is excellent, and an absorbent article 1 including the absorbent body 30 can be obtained. The joining between the sheets is preferably in a form of linearly joining several locations on the outer periphery and in the width direction of the sheet as shown in FIG. 1. However, other forms may be used as long as a space containing the superabsorbent polymer 100 is formed in a block shape between the sheets. At this time, known methods such as hot melt, heat seal, and ultrasonic seal can be appropriately used as the joining method.

[0034] The present invention has been described using the embodiments above. Needless to say, the technical scope of the present invention is not limited to the scope described in the above embodiments and examples. It is obvious to those skilled in the art that various changes or improvements can be made to the above embodiments. Also, it is obvious from the description of the claims that forms with such changes or improvements can also be included in the technical scope of the present invention.

Example

[0035] Hereinafter, the present invention will be described in detail with reference to examples. Note that the present invention is not limited to the examples shown below.

[0036] (Examples and Comparative Examples) A topsheet (air-through nonwoven fabric, basis weight 20 g / m 2 ) and a backsheet (breathable polyethylene film, basis weight 35 g / m 2 ) were prepared, and the absorbent article of Example 1 was produced in such a form that an absorber was installed between them. The absorber was a composite nonwoven fabric sheet formed by laminating and integrating a pulp fiber web on two continuous porous sheets (both urethane foam sheets, basis weight 80 g / m 2 ) and a spunbond nonwoven fabric (basis weight of the spunbond nonwoven fabric 15 g / m 2 , basis weight of the pulp fiber web 40 g / m 2 , one sheet each) in order from the skin-contact surface side, and 5 g each of a high liquid-permeability type superabsorbent polymer (absorption ratio: 35 g / g, liquid-permeation rate: 35 ml / min) was placed between the layers of the two continuous porous sheets, and a high-absorption type superabsorbent polymer (absorption ratio: 45 g / g, liquid-permeation rate: 8 ml / min) was placed between the layers of the continuous porous sheet and the composite nonwoven fabric sheet on the non-skin-contact surface side (intermediate layer), and the sheets were joined together. In Comparative Example 1, both the first superabsorbent polymer and the second superabsorbent polymer were of the high liquid permeability type. In Comparative Example 2, both the first superabsorbent polymer and the second superabsorbent polymer were of the high absorption type. In Comparative Example 3, no sheet was disposed in the intermediate layer, the high absorption type was used for the first superabsorbent polymer, and the high liquid permeability type was used for the second superabsorbent polymer. All other conditions were the same as those in the examples. In the examples and each comparative example, the dimension in the longitudinal direction of each sheet was 420 mm, the dimension in the width direction was 150 mm, and the dimension in the longitudinal direction of the absorbent article was 480 mm, and the dimension in the width direction was 200 mm, so as to be unified.

[0037] For the examples and each comparative example, evaluations were made on the following items. Total absorption amount: After being immersed in physiological saline for 5 minutes, it was drained on a wire mesh for 30 seconds, and the weight difference before and after absorption was measured. Repeated absorption rate: Using a jig with a bottom surface of 140×1000 mm, an outer diameter of 40 mm, an inner diameter of 35 mm, and a weight of 1400 g, 120 ml of physiological saline was injected three times at 10-minute intervals under a load, and the time taken to absorb 120 ml of the third injection was measured. Liquid return: After measuring the absorption rate three times, after 10 minutes, under a load condition of 35 gf / cm 2 The amount of water absorbed by liquid return and absorbed by a filter paper with a diameter of 55 mm in 1 minute was measured. Diffusion length: After measuring the absorption rate three times, the maximum length of the portion that had absorbed physiological saline was measured. Wearing comfort (from wearing to replacement): A 20-person monitor test was conducted, and the wearing comfort was evaluated according to the following criteria. ○: "The wearing comfort is good" for 16 or more and 20 or fewer people. △: "The wearing comfort is good" for 11 or more and 15 or fewer people. ×: There were no people with "good wearing comfort", or there were 1 or more and 10 or fewer people. The results are shown in Table 1.

[0038]

Table 1

[0039] As shown in Table 1, the absorbent article of Example 1 was excellent in all of the total absorption amount, repeated absorption rate, liquid return, and diffusion length, and had a good feeling of wearing. On the other hand, the absorbent article of Comparative Example 1 had a small total absorption amount and a large liquid return amount, the absorbent article of Comparative Example 2 had a slow repeated absorption rate, a short diffusion length, and was inferior in the feeling of wearing, and the absorbent article of Comparative Example 3 was inferior in the feeling of wearing. From the above, the absorbent article of the present invention can provide an absorbent article having good absorbency and a good feeling of wearing, which is particularly excellent in that the absorption rate does not decrease during repeated absorption, the amount of liquid return is small, and the diffusion of body fluid is excellent.

Explanation of Signs

[0040] 1 Absorbent article 10 Topsheet 20 Backsheet 30 Absorbent body 40 Joint part 50 Three-dimensional gathers 60 Superabsorbent sheet 70 Hydrophilic sheet 80, 81, 82 Continuous porous body sheet 90 Composite nonwoven fabric sheet 100, 101, 102 Superabsorbent polymer

Claims

1. An absorbent article comprising a liquid-permeable topsheet, a liquid-impermeable backsheet, and an absorber containing no fluff pulp between the topsheet and the backsheet, wherein the absorber has a superabsorbent sheet and a hydrophilic sheet that wraps the entire superabsorbent sheet, the superabsorbent sheet has a continuous porous body sheet made of polyurethane, a composite nonwoven sheet obtained by laminating and integrating a pulp fiber web on a spunbond nonwoven fabric by hydroentangling treatment, and a superabsorbent polymer encapsulated between the layers of each sheet, the superabsorbent sheet is laminated in the order of a first continuous porous body sheet, a second continuous porous body sheet, and the composite nonwoven sheet from the side in contact with the wearer's skin, the superabsorbent polymer includes a first superabsorbent polymer encapsulated between the layers of the first continuous porous body sheet and the second continuous porous body sheet, and a second superabsorbent polymer encapsulated between the layers of the second continuous porous body sheet and the composite nonwoven sheet, the absorption capacity of the first superabsorbent polymer is less than 40 g / g and the liquid permeability rate is 30 ml / min or more, the absorption capacity of the second superabsorbent polymer is 40 g / g or more and the liquid permeability rate is 10 ml / min or less, the ratio (2A / 1A) of the absorption capacity (2A) of the second superabsorbent polymer to the absorption capacity (1A) of the first superabsorbent polymer is 1.2 or more, the ratio (1S / 2S) of the liquid permeability rate (1S) of the first superabsorbent polymer to the liquid permeability rate (2S) of the second superabsorbent polymer is 5 or more, the surface of the composite nonwoven sheet that is contacted by the water jet and hydroentangled during the hydroentangling treatment is in contact with the second superabsorbent polymer, characterized absorbent article (However, in the superabsorbent sheet, those in which the superabsorbent polymer is mutually bonded by a bridging agent with the first continuous porous body sheet, the second continuous porous body sheet, and / or the composite nonwoven sheet are excluded.)

2. The continuous porous sheet has a basis weight of 30 g / m ２ or more and 300 g / m ２ or less, and has an apparent density of 100 kg / m ３ or more and 200 kg / m ３ or less. The absorbent article according to claim 1, characterized in that it is as described above.

3. The absorbent article according to claim 1 or 2, wherein the surface of the skeleton of the continuous porous body sheet is hydrophilic.

4. The absorbent article according to any one of claims 1 to 3, characterized in that the strength in the tensile test of the composite nonwoven fabric sheet is such that the force required to stretch a test piece formed to a width of 25 mm by 2 mm in the longitudinal direction is 1.5 N / 25 mm or more and 5.0 N / 25 mm or less in a test using a tensilon.

5. The absorbent article according to any one of claims 1 to 4, characterized in that the material of the spunbond nonwoven fabric is selected from one or a combination of two or more of the group consisting of nylon, vinylon, polyester, acrylic, polyethylene, polypropylene, and polystyrene.

6. The basis weight of the superabsorbent polymer is 30 g / m ２ or more and 300 g / m ２ or less, and the absorbent article according to any one of claims 1 to 5 is characterized thereby.

7. In the water entanglement step of subjecting the spunbond nonwoven fabric and the pulp fiber web to water entanglement treatment, the hole diameter Φ of the water jet nozzle for jetting the water jet is 0.06 mm or more and 0.15 mm or less, and the interval between the water jet nozzles is 0.4 mm or more and 1.0 mm or less. A method for producing the absorbent article according to any one of claims 1 to 6.

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