Absorbent bodies and absorbent articles

Abstract

To provide an absorbent article provided with a thin absorber which is excellent in body fluid diffusibility, has absorption performance, absorption rate, and return preventiveness at high level, and has excellent wear feeling and fitness.SOLUTION: An absorbent article 50 has: a liquid permeable top sheet 10; a liquid impermeable back sheet 30; and an absorber 20 arranged between them. The absorber 20 does not contain absorbent fiber but has an absorbent sheet 25. The absorbent sheet 25 has high absorbent polymer 12 sealed between multi-layers of a polyurethane continuous porous body sheet 21, and the multi-layers of the polyurethane continuous porous body sheet 21 are bonded so as to form a block-shaped space 61 sealing the high absorbent polymer 12. The absorbent sheet 25 has a belt-shaped compression grooves 23 along a longitudinal direction.SELECTED DRAWING: Figure 2

Description

Technical Field

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

Background Art

[0002] Generally, an absorbent article includes a liquid-permeable topsheet, a liquid-impermeable backsheet, and an absorber disposed therebetween, and absorbs and holds body fluids such as urine that have passed through the topsheet with the absorber, and is configured such that the body fluid does not contact the wearer's clothes or the like with the backsheet. Absorbent articles include, for example, pad products such as light incontinence pads, light incontinence liners, urine absorption pads, sanitary napkins, and paper diaper products such as pant-type paper diapers and tape-fastened type paper diapers. There are various forms according to the application, and they are widely used regardless of whether the user is an infant, an adult, or an elderly person.

[0003] One of the recent problems of absorbent articles is the provision of a thin absorbent article that is not conspicuous when worn, causes no discomfort when worn, and gives no feeling of being worn. When designing a thin absorbent article, usually, thinning of the absorber that occupies most of the absorbent article is considered, and many absorbent articles using a thin absorber have been proposed.

[0004] Patent Document 1 has a second sheet disposed between the topsheet and the absorber, and a planar ring-shaped leak prevention groove (squeezing groove) provided along the contour of the absorber on the skin side surface (topsheet surface), and the density of the absorber is 0.12 g / cm 3 Higher, and the capillary force of the second sheet is 1.5×10 3An absorbent article having N or more is disclosed (Claim 1, Paragraph 0008, FIG. 1). As a specific example of the absorber, an absorbent sheet is disclosed in which particles of a superabsorbent polymer are sandwiched and fixed between two sheets of absorbent paper or nonwoven fabric and which does not contain absorbent fibers such as fluff pulp (Paragraph 0041). According to Patent Document 1, 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 absorption power at a high level, giving a sense of security and a comfortable wearing feeling during wearing (Paragraph 0004).

[0005] Patent Document 2 discloses an absorbent article having an upper absorbent layer (a nonwoven fabric disposed on the skin side) and a lower absorbent layer disposed opposite to the non-skin side of the upper absorbent layer (a hydrophilic porous body located on the non-skin side and a superabsorbent polymer fixed to the skin-side surface of the hydrophilic porous body), using an absorbent sheet that does not contain absorbent fibers as the absorber, the lower absorbent layer being substantially vertically long, and the central portion in the width direction of the lower absorbent layer having a smaller distribution amount of the superabsorbent polymer than other portions of the lower absorbent layer (FIG. 2, Abstract). Examples of the hydrophilic porous body include cellulose-based sponges and urethane-based foams (Paragraph 0014). According to Patent Document 2, by using a hydrophilic porous body for the lower absorbent layer and optimizing the distribution of the superabsorbent polymer, it is possible to maintain high liquid diffusibility and liquid retention properties while having a thin thickness and a high absorption rate.

Prior Art Documents

Patent Documents

[0006]

Patent Document 1

Patent Document 2

Summary of the Invention

Problems to be Solved by the Invention

[0007] In Patent Documents 1 and 2, although an absorbent sheet is used as an absorber to reduce the thickness of the absorbent article, when the absorbent article is thinned and lightened as described in Patent Document 1 or Patent Document 2, a certain degree of absorption performance must be sacrificed. In particular, in light incontinence products and urine collection pads with a narrow absorbent area, sufficient absorption performance cannot be maintained, and it is difficult to cope with multiple absorptions of body fluids, which is one of the current problems of absorbent articles.

[0008] In addition, in absorbent articles, both the absorption speed (hereinafter also referred to as "absorption rate") and the small amount of backflow are important as indicators of absorption performance. However, in a thin absorbent article using a conventional absorbent sheet as an absorber, it is difficult to satisfy both at a high level.

[0009] More specifically, in the absorbent article of Patent Document 1, the superabsorbent polymer absorbs body fluid inside the absorbent sheet and swells, binds to each other to form a large mass, and gel blocking that reduces the diffusibility and absorption rate of body fluid is likely to occur. Further, the leakage prevention groove described in Patent Document 1 is provided on the skin side surface layer of the absorbent article, and does not improve the diffusibility of body fluid inside the absorbent sheet. In the absorbent article of Patent Document 2, although the diffusibility of body fluid is ensured to some extent by making the distribution amount of the superabsorbent polymer in the central portion in the width direction of the lower absorbent layer less than that of other portions of the lower absorbent layer, since there is likely to be a large difference in liquid permeability between the non-woven fabric which is the upper absorbent layer and the hydrophilic porous body which constitutes a part of the lower absorbent layer, problems such as lateral leakage of body fluid and an increase in the amount of backflow are likely to occur.

[0010] An object of the present invention is to provide an absorbent article provided with a thin absorber having excellent body fluid diffusibility, having high levels of absorption performance, absorption rate, and backflow prevention performance, and also excellent in wearing comfort and fit.

Means for Solving the Problems

[0011] As a result of intensive research to solve the above problems, the present inventors used polyurethane continuous porous sheets as sheet materials disposed on the skin side and the non-skin side of the absorbent sheet, respectively, and formed a block-shaped space in which a superabsorbent polymer was encapsulated between the multiple layers of the polyurethane continuous porous sheets. The absorbent sheet was formed by partially joining the multiple layers so that the superabsorbent polymer was encapsulated between the multiple layers, and by providing strip-shaped squeezing grooves in a plan view on the skin side surface of the absorbent sheet, the inventors found that a desired absorbent article could be obtained, and thus completed the present invention. The present invention relates to the following absorbent body and an absorbent article including the absorbent body.

[0012] (1) An absorbent article comprising a liquid-permeable topsheet, a liquid-impermeable backsheet, and an absorbent body disposed between them, wherein the absorbent body does not contain absorbent fibers and has an absorbent sheet, the absorbent sheet has a superabsorbent polymer encapsulated between multiple layers of a polyurethane continuous porous sheet, the multiple layers of the polyurethane continuous porous sheet are joined so as to form a block-shaped space for encapsulating the superabsorbent polymer, and the absorbent sheet is characterized by having strip-shaped squeezing grooves along the longitudinal direction. (2) The absorbent article according to (1) above, wherein the absorbent sheet has a plurality of the squeezing grooves. (3) The absorbent article according to (1) or (2) above, wherein the width of the squeezing groove is 2 mm or more and 30 mm or less. (4) The absorbent article according to any one of (1) to (3) above, wherein the length of the squeezing groove is 20% or more and 90% or less of the length of the entire absorbent sheet. (5) The absorbent article according to any one of (1) to (4) above, wherein the depth of the squeezing groove is 10% or more and 80% or less of the thickness of the entire absorbent sheet. (6) The superabsorbent polymer present between the squeezing grooves when there are a plurality of the squeezing grooves, and the superabsorbent polymer present within 20 mm around the squeezing groove are fixed between the multiple layers of the polyurethane continuous porous sheet. The absorbent article according to any one of (2) to (5) above. (7) The polyurethane 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 any one of (1) to (6) above. (8) The polyurethane continuous porous sheet has a hydrophilic skeleton surface. The absorbent article according to any one of (1) to (7) above. (9) The basis weight of the superabsorbent polymer in the absorbent sheet is 30 g / m 2 or more and 300 g / m 2 or less. The absorbent article according to any one of (1) to (8) above.

Advantages of the Invention

[0013] According to the present invention, there is provided an absorbent article having a thin absorbent body that is excellent in body fluid diffusibility, has high levels of absorption performance, absorption speed, and prevention of backflow, and is also excellent in wearing comfort and fit.

Brief Description of the Drawings

[0014]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Modes for Carrying Out the Invention

[0015] In this specification, the wearing of an absorbent article refers to the state in which the absorbent article is worn on the body, regardless of whether it is before or after absorbing body fluids. 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 crotch of the wearer when the absorbent article is worn on the body. The width direction is the direction indicated by X in the figure, which is orthogonal to the longitudinal direction. The thickness direction is the direction indicated by Z in the figure, in which the respective constituent members are laminated. The skin side surface is the surface that contacts the skin of the wearer and the surface facing the skin when the absorbent article is worn. The non-skin side surface is the surface that contacts the clothing of the wearer or the surface facing the clothing. Body fluids refer to liquids discharged from the body to the outside, such as urine, blood, and moisture in soft feces.

[0016] <Absorbent article> Hereinafter, the absorbent article 50 according to the present embodiment will be described with reference to the drawings. FIGS. 1 to 3 show the absorbent article 50. FIG. 4 shows the absorbent sheet precursor 26. FIG. 5 shows a typical flow 65 of body fluid in the absorber 20. FIGS. 6 and 7 show absorbent articles 50A and 50B according to Example 7 and Comparative Example 1, respectively. These drawings do not define the shapes, dimensions, size relationships, etc. of the respective constituent members in the absorbent article 50.

[0017] The absorbent article 50 of the present embodiment can be used as various absorbent articles for infants, adults, and the elderly. Examples include pad products such as light incontinence products, light incontinence liners, urine collection pads, sanitary napkins, etc., and paper diaper products such as pant-type paper diapers and tape-fastened type paper diapers. Among these, by taking advantage of its thinness and the fact that the absorption amount and absorption rate do not decrease even after multiple absorptions, it can be suitably used particularly as pad products such as light incontinence products and urine collection pads. Also, various paper diaper products as the outer layer and the absorbent article 50 as the inner layer may be combined. The dimensions (maximum dimensions) in the longitudinal direction and the width direction of the absorbent article 50 are not particularly limited, but are, for example, in the range of 100 mm or more and 800 mm or less, and in the range of 50 mm or more and 500 mm or less, respectively. When the dimensions of the absorbent article 50 are adjusted to the above ranges, absorbent articles in various forms can be easily obtained.

[0018] The absorbent article 50 shown in FIGS. 1 and 2 includes a liquid-permeable topsheet 10 located on the skin side, a liquid-impermeable backsheet 30 disposed opposite to the topsheet 10 and located on the non-skin side, an absorber 20 disposed between the topsheet 10 and the backsheet 30, and a pair of three-dimensional gathers 40 provided on the skin side surface of the topsheet 10.

[0019] The absorber 20 includes an absorbent sheet 25 that does not contain absorbent fibers such as fluff pulp. As shown in FIG. 2, from the skin side toward the non-skin side, it has a multi-layer of a polyurethane continuous porous sheet 21 and a SAP layer in which a superabsorbent polymer 12 is encapsulated between the multi-layers. In the multi-layers of the polyurethane continuous porous sheet 21 (SAP layer), the SAP layer is divided into block-shaped spaces 61 in the plane direction, and strip-shaped joints 60 that partially join the multi-layers of the polyurethane continuous porous sheet 21 are provided vertically and horizontally. On the skin side surface of the absorbent sheet 25, a squeezing groove 23 that is recessed from the skin side toward the non-skin side is provided.

[0020] According to the present embodiment, the multi-layers of the polyurethane continuous porous sheet 21 are partially joined by the joining part 60, the multi-layers are divided into block-shaped spaces 61, the superabsorbent polymer 12 is enclosed in the block-shaped spaces 61, and a strip-shaped squeezing groove 23 is provided on the skin side surface in plan view to form the absorbent sheet 25. According to this configuration, the following first, second, and third effects can be obtained. First, the polyurethane continuous porous sheet 21 is used for both the skin-side material and the non-skin-side material of the absorbent sheet 25 to eliminate the difference in liquid permeability between the skin-side material and the non-skin-side material, and the squeezing groove 23 significantly improves the body fluid diffusibility of the entire absorbent sheet 25, thereby significantly suppressing the occurrence of lateral leakage and backflow of body fluids. Second, the multi-layers of the polyurethane continuous porous sheet 21 are divided into a plurality of block-shaped spaces 61 for enclosing the superabsorbent polymer 12, and further, by providing the squeezing groove 23, the superabsorbent polymer 12 that has absorbed the body fluid swells and binds, preventing the occurrence of gel blocking in which the superabsorbent polymer 12 becomes a large mass that suppresses the diffusion of the body fluid. Therefore, excellent body fluid diffusibility is maintained from the initial use to the end of use of the absorbent article 50, and particularly, the absorption rate and absorption amount do not decrease during repeated absorption. Third, the polyurethane continuous porous sheet 21 contains many pores and has a structure with appropriate elasticity. Before the body fluid is absorbed, it is difficult to feel the hardness of the superabsorbent polymer 12. Immediately after the body fluid is absorbed, the superabsorbent polymer 12 swells into a jelly-like state and the compressive feeling is dispersed due to being divided into block-shaped spaces. After the body fluid is absorbed, the superabsorbent polymer 12 swells and solidifies, relieving the lumpy feeling. In addition, since the superabsorbent polymer 12 is arranged in the block-shaped space 61, the displacement and movement of the polymer are suppressed, and the thickness and touch feeling can be maintained more uniformly in the longitudinal direction and the width direction even after the body fluid is absorbed. Therefore, the wearing feeling and the fitting property are improved. Therefore, according to the present embodiment, swelling after body fluid absorption is suppressed, so that particularly during repeated absorption, the absorption rate does not decrease, the backflow amount is small, the body fluid diffusion is excellent, and a thin absorbent body 20 and an absorbent article 50 including the absorbent body 20 with good absorbency and wearing feeling are provided.

[0021] The absorbent article 50 of the present embodiment is based on a basic structural unit including a topsheet 10, an absorber 20, and a backsheet 30. If necessary, various known modifications can be made, such as the arrangement of the three-dimensional gathers 40 as described above, the arrangement of a liquid-permeable transfer sheet (not shown) or a liquid-permeable second sheet between the topsheet 10 and the absorber 20. Hereinafter, the constituent members of the absorbent article 50 will be described in more detail in the order of the topsheet 10, the absorber 20, the backsheet 30, and the three-dimensional gathers 40.

[0022] <Topsheet> The topsheet 10 is a liquid-permeable sheet-like base material that allows body fluid to quickly pass therethrough toward the absorber 20. The topsheet 10 preferably has a soft texture and does not irritate the skin so that it may contact the skin of the wearer. Examples of the base material include a hydrophilic sheet, a composite sheet that is a laminate of the same or different hydrophilic sheets, a perforated film such as a perforated polyethylene film, a foamed film such as a polyethylene foam or a urethane foam, and the like. Examples of the hydrophilic sheet include an air-through nonwoven fabric, a thermal-bond nonwoven fabric, a spunlace nonwoven fabric, a spunbond nonwoven fabric, etc., which are made using one or more of synthetic fibers made of synthetic resins such as polypropylene and polyethylene, regenerated fibers such as rayon, and natural fibers such as cotton. Among these, nonwoven fabrics are preferred, and air-through nonwoven fabrics, thermal-bond nonwoven fabrics, spunbond nonwoven fabrics, etc. are more preferred.

[0023] From the viewpoint of improving liquid permeability, the topsheet 10 may be embossed or perforated on the surface. From the viewpoint of reducing irritation to the skin, the topsheet 10 may contain one or more of a lotion, an antioxidant, an anti-inflammatory component, a pH adjuster, an antibacterial agent, a humectant, etc. The basis weight of the topsheet 10 is, for example, 18 g / m 2 to 400 g / m 2 in the following range. The shape of the topsheet 10 is not particularly limited, and any shape that covers part or all of the absorber 20 and is necessary to guide body fluid to the absorber 20 so as not to leak is acceptable.

[0024] <Absorbent body> The absorbent body 20 has a longitudinal dimension (maximum length) in the range of, for example, 100 mm or more and 800 mm or less, 150 mm or more and 500 mm or less, or 270 mm or more and 500 mm or less. The widthwise dimension (maximum width) of the absorbent body 20 is in the range of, for example, 50 mm or more and 500 mm or less, 60 mm or more and 400 mm or less, or 70 mm or more and 105 mm or less. Further, when the planar shape of the absorbent body 20 is an hourglass shape, the longitudinal dimension is in the range of 180 mm or more and 800 mm or less, and the widthwise dimensions of the ventral side portion and the dorsal side portion that respectively contact the abdomen and the back of the wearer are both in the range of 60 mm or more and 400 mm or less, and the widthwise dimension of the crotch portion that contacts the crotch of the wearer is in the range of 90 mm or more and 250 mm or less. Embossing may be performed on the entire surface or a part of the absorbent body 20. Examples of the planar shape of the absorbent body 20 include an hourglass shape, an I shape, a rectangle, a rounded rectangle with rounded corners, an ellipse, and the like.

[0025] The absorbent body 20 of the present embodiment includes an absorbent sheet 25 that does not contain absorbent fibers such as fluff pulp, and a hydrophilic sheet 24 that wraps the absorbent sheet 25. The absorbent sheet 25 will be described in detail later. The hydrophilic sheet 24, for example, places the non-skin side surface of the absorbent sheet 25 near the central portion in the width direction, and after adhesively bonding them as necessary, the both sides in the width direction of the hydrophilic sheet 24 are overlapped on the skin side of the absorbent sheet 25 by C-folding, and the overlapped portion is adhesively bonded as necessary to wrap the entire absorbent sheet 25. The hydrophilic sheet 24 not only wraps the entire absorbent sheet 25 as described above, but also covers the non-skin side surface, both side surfaces in the width direction, and the vicinity of both ends in the width direction of the skin side surface of the absorbent sheet 25, and between the top sheet 10 and the absorbent sheet 25, the absorbent sheet 25 may be wrapped so that both ends in the width direction of the hydrophilic sheet 24 face each other while being separated, and a slit-shaped space extending in the longitudinal direction is formed.

[0026] (Hydrophilic sheet) As the hydrophilic sheet 24, any commonly used one in this field can be used. For example, hydrophilic non-woven fabrics such as thermal-bonded non-woven fabric, spunbond non-woven fabric, airlaid non-woven fabric, air-through non-woven fabric, pulp-containing non-woven fabric, tissue paper, absorbent paper, etc. can be mentioned. Among the hydrophilic non-woven fabrics, hydrophilic non-woven fabrics such as thermal-bonded non-woven fabric, spunbond non-woven fabric, air-through non-woven fabric, pulp-containing non-woven fabric are more preferable, and air-through non-woven fabric, pulp-containing non-woven fabric, spunbond non-woven fabric, etc. are even more preferable. The thickness of the hydrophilic sheet 24 is in the range of, for example, 0.10 mm or more and 0.25 mm or less, and the basis weight is in the range of, for example, 5 g / m 2 or more and 40 g / m 2 or less. Hereinafter, each member constituting the absorbent sheet will be described.

[0027] (Polyurethane continuous porous sheet) The polyurethane continuous porous sheet 21 is used for both the skin-side material and the non-skin-side material of the absorbent sheet 25, contains a polyurethane continuous foam (hereinafter also referred to as "soft polyurethane foam") as a main component, has good liquid permeability, and is rich in flexibility. Although the polyurethane continuous porous sheet 21 has good liquid permeability, it is inferior in liquid permeability compared to hydrophilic non-woven fabrics and the like. Utilizing this characteristic, as shown in FIG. 5, the body fluid that has entered the absorbent sheet 25 collides with the polyurethane continuous porous sheet 21 on the non-skin side and flows in the plane direction (longitudinal direction and width direction) as shown by the arrow 65, making it easier to spread throughout the absorbent sheet 25. It should be noted that when the body fluid that has passed through the top sheet 10 permeates inside the absorbent sheet 25, although it instantaneously receives the resistance of the polyurethane continuous porous sheet 21 on the skin side, since the squeezing groove 23 described later is formed on the skin side surface of the absorbent sheet 25, the body fluid is quickly absorbed throughout the absorbent sheet 25, preventing lateral leakage and liquid return. Here, "containing as a main component" means containing 50% by mass or more of soft polyurethane foam in the whole. As the polyurethane continuous porous sheet 21, for example, a single-layer sheet containing soft polyurethane foam as a main component, a single-layer sheet made of soft polyurethane foam, etc. can be used.

[0028] The polyurethane continuous porous sheet 21 uniformly diffuses the body fluid that has passed through the topsheet 10 throughout the absorber 20 (absorbent sheet 25), for example. The polyurethane continuous porous sheet 21 also has flexibility, which alleviates the rough feeling of the particles of the superabsorbent polymer 12 before body fluid absorption, and the jelly-like compressive feeling and the lumpy feeling after the superabsorbent polymer 12 swells after body fluid absorption, thereby greatly improving the wearing comfort of the absorbent article 50.

[0029] The flexible polyurethane foam can be obtained, for example, by mixing raw material compounds such as polyols and polyisocyanates, additives such as foaming agents, foam stabilizers, and catalysts, and heating the resulting mixture to cause foaming. Alternatively, a gas-phase foaming agent may be injected while reacting the raw material compounds under heating. By appropriately selecting reaction conditions such as the types of raw material compounds, the types and amounts of additives, the heating temperature during foaming, the foaming time, and the pressure during foaming, various properties of the flexible polyurethane foam such as the foaming ratio, apparent density, tensile strength, tensile elongation at break, elongation stress, mean coefficient of friction (MIU), and coefficient of friction variation (MMD) can be adjusted. For example, the foaming ratio of the flexible polyurethane foam is in the range of 10 times or more and 60 times or less from the viewpoints of body fluid diffusibility, flexibility, etc. Also, the flexible polyurethane foam can be produced according to the extraction method, the W / O emulsion method, etc.

[0030] The basis weight and apparent density of the polyurethane continuous porous sheet 21 are, from the viewpoints of body fluid diffusibility, flexibility, prevention of liquid return and body fluid leakage, air permeability, and stuffiness, etc., respectively, the basis weight is, for example, 30 g / m 2 or more and 300 g / m 2 or less, or 50 g / m 2 or more and 250 g / m 2 or less, and the apparent density is 100 kg / m 3 or more and 200 kg / m 3 or less, or 120 g / m 2 or more and 180 g / m 2 or less.

[0031] The thickness of the polyurethane continuous porous sheet 21 is, for example, in the range of 1.0 mm or more and 4.0 mm or less, or in the range of 1.5 mm or more and 3.2 mm or less. The thickness is measured under no-load conditions, for example, using a "height gauge" (manufactured by Mitutoyo Corporation).

[0032] The surface of the skeleton of the soft polyurethane foam contained in the polyurethane continuous porous sheet 21 may be hydrophilic or hydrophobic. However, from the viewpoint of the ease of wetting by body fluids and the like, in a preferred embodiment, the surface of the skeleton is hydrophilic. Examples of the hydrophilic skeleton include those containing a polyol and a polyalkylene oxide polyol. Further, a hydrophobic skeleton may be hydrophilized by introducing a hydrophilic group derived from a surfactant, ethylene oxide, or the like. Whether the surface of the skeleton is hydrophilic or not is determined as follows: First, a sample cut out from the polyurethane continuous porous sheet 21 with dimensions of 10 mm or more in width and 10 mm or more in length is placed still on a plane so as not to be bent. Next, 10 drops of water droplets (0.05 mL) of ion-exchanged water are dropped onto the sample, and the time until the sample absorbs the water droplets is measured. If this time is within 5 seconds, or if 8 or more water droplets are absorbed, it is determined that the sample is hydrophilic.

[0033] <Block-shaped space> In the present embodiment, as shown in FIGS. 1 and 2, between the multilayered polyurethane continuous porous sheets 21, the polyurethane continuous porous sheets 21 on the skin side and the non-skin side are partially joined, and a plurality of block-shaped spaces 61 for enclosing the superabsorbent polymer 12 are formed in the plane direction between the multilayered sheets. The joint portion 60 of the present embodiment is strip-shaped in plan view, and includes a frame-shaped region that extends substantially linearly in the longitudinal direction and the width direction along the outer edge in the vicinity of the outer edge of the absorbent article 50, and a plurality of partition regions that extend substantially at equal intervals in the longitudinal direction and substantially linearly in the width direction inside the frame-shaped region, and divide the inside of the frame-shaped region into a plurality of block-shaped spaces 61 of substantially the same size. The frame-shaped region is not limited to the present embodiment, and may be provided so as to extend substantially linearly in the longitudinal direction and the width direction along the outer edge of the absorbent article 50. Also, the number of partition regions may be one or any plurality. The widthwise dimension, the number and arrangement in the longitudinal and width directions of the joint portion 60 are appropriately selected according to the amount of the superabsorbent polymer 12 enclosed in the block-shaped space 61, the method of forming the joint portion 60, etc., so that the polyurethane continuous porous sheets 21 on the skin side and the non-skin side do not peel off. The joint portion 60 is composed of, for example, a hot melt adhesive, or may be a welded region by heat sealing, ultrasonic sealing, or the like.

[0034] In the present embodiment, the plurality of block-shaped (or rectangular) spaces 61 are closed spaces that are arranged in parallel in the longitudinal direction and surrounded by the joint portion 60, and the superabsorbent polymer 12 is enclosed therein. The amount of each superabsorbent polymer 12 enclosed in the block-shaped space 61 may be the same or different, but the basis weight of the superabsorbent polymer 12 is, for example, 30 g / m 2 or more and 300 g / m 2 or less. As a result, the superabsorbent polymer 12 that has absorbed body fluid and swelled binds over a wide range, preventing the occurrence of gel blocking that hinders the diffusion of body fluid. Therefore, even when body fluid is repeatedly absorbed, the decrease in absorption performance such as absorption rate and absorption amount is significantly reduced. In the present embodiment, the shape of the block-shaped space 61 provided between the multilayered polyurethane continuous porous sheets 21 is substantially rectangular in plan view, but is not limited thereto, and can be various shapes such as a triangle (particularly an equilateral triangle), a hexagon (particularly a regular hexagon), a circle, and a concentric circle.

[0035] (Superabsorbent Polymer) As the superabsorbent polymer 12, there is no particular limitation as long as it can absorb body fluids and prevent backflow. Examples include polyacrylate salts, polyaspartate salts, (starch-acrylic acid) graft copolymers, (acrylic acid-vinyl alcohol) copolymers, (isobutylene-maleic anhydride) copolymers, and their saponified products. Among these, from the viewpoint of the absorption amount per unit weight, polyacrylate salts are preferred, alkali metal polyacrylate salts are more preferred, and sodium polyacrylate is even more preferred. The superabsorbent polymer 12 can be used alone or in combination of two or more kinds.

[0036] The superabsorbent polymer 12 is used, for example, in the form of particles, fibers, etc. From the viewpoint of ease of handling, etc., it is preferably used in the form of particles. At this time, by avoiding the use of the superabsorbent polymer 12 in the form of fine powder with poor fluidity as a powder, and using the superabsorbent polymer 12 having a median particle diameter, the basic performance related to absorption can be enhanced, and the rough touch generated by the absorber 20 becoming hard can be reduced. The median particle diameter of the superabsorbent polymer 12 is, for example, in the range of 50 μm or more and 600 μm or less, or in the range of 100 μm or more and 500 μm or less.

[0037] To enclose the superabsorbent polymer 12 in the block-shaped space 61, for example, a hot melt adhesive is used. As the hot melt adhesive, those having a melting point of 100 °C or more and 180 °C or less can be used without particular limitation. Examples include synthetic rubber-based hot melt adhesives such as styrene-butadiene-styrene copolymers and styrene-isoprene-styrene copolymers, and olefin-based hot melt adhesives such as ethylene-vinyl acetate copolymers. As the coating method of the hot melt adhesive, known methods such as the curtain coating method and the spiral method for non-contact coating of the molten hot melt adhesive from a nozzle, and the slot method for contact coating can be used. The content of the hot melt adhesive is, from the viewpoint of not impairing the absorbency of the superabsorbent polymer 12 and the feel on the skin during wearing, for example, 10 g / m2 It is within the following range.

[0038] <Squeezing groove> As shown in FIGS. 2 and 3, the squeezing groove 23 of the present embodiment extends substantially linearly along the skin side surface of the absorbent sheet 25 in the longitudinal direction, and the polyurethane continuous porous sheet 21 on the skin side is recessed toward the non-skin side, and its non-skin side surface is provided so as to contact or join with the skin side surface of the polyurethane continuous porous sheet 21 on the non-skin side. That is, the squeezing groove 23 is a groove provided on the skin side surface of the absorbent sheet 25. The squeezing groove 23 includes a first form formed along a joining portion 60 extending in the longitudinal direction, a second form formed near the boundary between the joining portion 60 extending in the longitudinal direction and a block-shaped space 61 along it, and a third form formed so as to penetrate a plurality of block-shaped spaces 61 connected in the longitudinal direction in the longitudinal direction. From the viewpoint of increasing the body fluid receiving amount of the absorbent sheet 25 and preventing lateral leakage and backflow, the third form is preferable. The squeezing groove 23 can be formed on the skin side surface of the absorbent sheet 25 by using, for example, heat embossing, ultrasonic embossing, high-frequency embossing, or the like.

[0039] Here, the number of the squeezing grooves 23 may be one or a plurality. In the present embodiment, the shape of the bottom surface of the squeezing groove 23 is substantially flat, but it is not limited to this, and it may be a slope, a circular shape in cross-section, a shape having irregularities, a shape in which two or more of these shapes are combined, or the like. In the present embodiment, the squeezing groove 23 is substantially linear, but it is not limited to this, and it may be a linear shape combining a straight line and a curve, a curved shape, or the like.

[0040] By providing the squeezing groove 23 in such a form, the body fluid diffusibility of the entire absorbent sheet 25 is significantly improved, the occurrence of gel blocking is suppressed, and even when repeated absorption is performed a plurality of times, a decrease in the absorption rate and absorption amount is prevented. Further, even when a large amount of body fluid is discharged at once, the occurrence of lateral leakage, backflow, etc. is prevented.

[0041] The width of the squeezing groove 23 is, for example, in the range of 2 mm or more and 30 mm or less, or in the range of 3 mm or more and 25 mm or less. The length of the squeezing groove 23 is, for example, in the range of 20% or more and 90% or less, or 30% or more and 80% or less of the total length of the absorbent sheet 25. The formation position of the squeezing groove 23 includes, for example, the range from one end in the longitudinal direction of the absorbent sheet 25 to the middle part in the longitudinal direction, the range from one middle part to another middle part in the longitudinal direction of the absorbent sheet 25, and the like. The depth of the squeezing groove 23 is, for example, in the range of 10% or more and 80% or less, or 20% or more and 70% or less of the total thickness of the absorbent sheet 25. Here, the depth of the squeezing groove 23 is the length of the perpendicular line dropped from the opening surface of the squeezing groove 23 to the bottom surface on the skin side surface of the absorbent sheet 25. Measure the length of the perpendicular line at any five points, and average the obtained measured values as the depth. The total thickness of the absorbent sheet 25 is measured under no load using a height gauge (manufactured by Mitutoyo Corporation). When there are a plurality of squeezing grooves 23, the widths, lengths, and / or depths of the plurality of squeezing grooves 23 may be the same or different.

[0042] In a preferred embodiment, when the absorbent sheet 25 has a plurality of squeezing grooves 23, the plurality of squeezing grooves 23 are adjacent to each other in the width direction, and between one squeezing groove 23 and another squeezing groove 23, there is a superabsorbent polymer 12 encapsulated in the multilayer of the polyurethane continuous porous sheet 21 (or within the block-shaped space 61). Such a superabsorbent polymer 12 is fixed within the multilayer (or within the block-shaped space 61) in this embodiment. Also, regardless of the number of squeezing grooves 23 in the absorbent sheet 25, the superabsorbent polymer 12 exists around the squeezing grooves 23, particularly around the width direction. And the superabsorbent polymer 12 existing within 20 mm around the squeezing grooves 23 is fixed within the aforementioned multilayer (or within the block-shaped space 61) in this embodiment. The range where the superabsorbent polymer 12 is fixed is also referred to as the SAP fixing region. According to this embodiment, from the initial stage to the end stage of use of the absorbent article 50, the movement of the superabsorbent polymer 12 is suppressed around the squeezing grooves 23 that serve as the body fluid flow path and maintain the high level of body fluid diffusibility of the absorbent sheet 25. Therefore, the occurrence of gel blocking around the squeezing grooves 23 is significantly suppressed, a body fluid flow path from the squeezing grooves 23 to the entire absorbent sheet 25 is ensured, and a decrease in the absorption speed and absorption amount is reliably prevented. Also, when the wearer of the absorbent article 50 loses the balance of the posture and cannot maintain the horizontal state of the absorbent article 50 from the initial stage to the end stage of use, and the absorbent article 50 is inclined in any of the up-down directions of the front, back, left, or right, since the superabsorbent polymer 12 is fixed around the squeezing grooves 23, after the body fluid is absorbed, the walls of the swollen superabsorbent polymer 12 fixed on both sides of the squeezing grooves 23 are formed and maintained along the longitudinal direction, and a decrease in the absorption speed and absorption amount is reliably prevented.

[0043] <Method for manufacturing absorbent sheet and absorbent body> The absorbent sheet 25 of the present embodiment is, for example, on the skin side surface of the polyurethane continuous porous sheet 21 disposed on the non-skin side, leaving a planned formation area of the joint portion 60, and spraying the superabsorbent polymer 12 in a predetermined pattern; and, if necessary, supplying a hot melt adhesive to fix the superabsorbent polymer 12 existing between the plurality of squeezing grooves 23 and the superabsorbent polymer 12 existing within 20 mm or less from the planned formation area of the squeezing grooves 23; overlapping the skin side surface of the polyurethane continuous porous sheet 21 on the non-skin side on which the superabsorbent polymer 12 is sprayed or fixed with the non-skin side surface of the polyurethane continuous porous sheet 21 disposed on the skin side to obtain an absorbent sheet precursor 26 shown in FIG. 4; forming the joint portion 60 while pressurizing and / or heating the absorbent sheet precursor 26; and forming the squeezing grooves 23 in the laminate having the joint portion 60. The joint portion 60 can be formed, for example, using a hot melt adhesive or by a welding method such as heat sealing or ultrasonic sealing. By wrapping the obtained absorbent sheet 25 with the hydrophilic sheet 24 as described above, the absorber 20 is obtained. The hot melt adhesive used here and its coating method are the same as those of the hot melt adhesive for fixing and supporting the superabsorbent polymer 12.

[0044] <Backsheet> The backsheet 30 may be formed using a liquid-impermeable breathable or non-breathable base material that prevents the body fluid held by the absorber 20 from wetting the clothing. Examples of the base material include a resin film, a composite sheet which is a laminate of a resin film and a non-woven fabric, and the like. The non-woven fabric used for the composite sheet is not particularly limited in the manufacturing method. Examples thereof include single-layer non-woven fabrics such as spunbond non-woven fabric and meltblown non-woven fabric, composite non-woven fabrics such as a spunbond non-woven fabric / meltblown non-woven fabric laminate and a spunbond non-woven fabric / meltblown non-woven fabric / spunbond non-woven fabric laminate, and these composite materials. Examples of the resin film include polyester, polyvinyl alcohol, polyethylene, polypropylene, and a composite film of polyethylene and polypropylene.

[0045] The basis weight of the backsheet 30 is, from the viewpoints of strength and processability, for example, 15 g / m 2 or more and 40 g / m 2 or less. Further, in order to prevent stuffiness during wearing, it is preferable to provide the backsheet 30 with air permeability. In order to provide the backsheet 30 with air permeability, for example, a filler may be blended into the resin film of the base material, or the backsheet 30 may be embossed. Incidentally, calcium carbonate can be cited as the filler, and the blending method can be carried out without limitation by a known method.

[0046] <Three-dimensional gathers> The three-dimensional gathers 40 are fixed to the skin side surface of the topsheet 10 along the longitudinal direction of the absorbent article 50 near both ends in the width direction of the absorbent article 50, for example, in order to prevent lateral leakage of body fluid excreted by the wearer of the absorbent article 50. The three-dimensional gathers 40 include an elastic stretch member 40a and a water-repellent and / or waterproof sheet member 40b.

[0047] The elastic stretch member 40a is disposed along the longitudinal direction near the free end (the other end) of the sheet member 40b, imparts standing property to the free end, and enables the free end and the vicinity region thereof of the sheet member 40b to be deformed according to the body shape of the wearer. In the present embodiment, one end (fixed end) in the width direction of the sheet member 40b is fixed near both ends in the width direction of the skin side surface of the backsheet 30, the middle portion in the width direction is fixed near both ends in the width direction of the skin side surface of the topsheet 10, and the other end in the width direction is a free end having standing property. The fixing position of the fixed end (one end in the width direction) of the sheet member 40b is not limited to the present embodiment, and examples thereof include the non-skin side surface of the backsheet 30, the skin side surface or the non-skin side surface near both ends in the width direction of the joined body of all or part of the edges of the topsheet 10 and the backsheet 30 that houses the absorber 20 inside, and near both ends in the width direction of the skin side surface of the topsheet 10.

[0048] The sheet member 40b 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 made of hydrophobic fibers, and examples thereof include spunbond nonwoven fabric, meltblown nonwoven fabric, and composite nonwoven fabric (SMS nonwoven fabric) which is a spunbond nonwoven fabric / meltblown nonwoven fabric / spunbond nonwoven fabric laminate. The basis weight of the sheet member 40b is, for example, 13 g / m 2 More than 20g / m 2 The range is as follows: As the elastic and stretchable member 40a, for example, thread-, string- or band-shaped members made of natural rubber, synthetic rubber, polyurethane or the like can be used as appropriate.

[0049] <Method for manufacturing absorbent articles> The absorbent article 50 can be manufactured by a known manufacturing method, for example, a manufacturing method including the steps of placing the absorber 20 between the top sheet 10 and the back sheet 30, fixing the top sheet 10 and the back sheet 30 partially or entirely around the periphery using a hot melt adhesive, heat embossing, ultrasonic embossing, high-frequency embossing, or the like, and providing three-dimensional gathers 40 at predetermined positions on the back sheet 30 and the top sheet 10. When the absorbent article 50 is a urine absorption pad or a light incontinence pad, it can be individually packaged in a package and then folded lengthwise in thirds. Leg gathers, waist gathers, side flaps, and the like can be provided as needed.

[0050] 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 apparent to those skilled in the art that various modifications and improvements can be made to the above embodiments. Furthermore, it is clear from the claims that such modifications and improvements can also be included within the technical scope of the present invention. [Example]

[0051] The present embodiment will be described in more detail below with reference to examples and comparative examples.

[0052] (Examples 1 - 7 and Comparative Example 1) (Production of Absorbent Articles) A polyurethane continuous foam sheet (the surface of the skeleton is hydrophilic, basis weight 80 g / m 2 , thickness 2.0 mm, apparent density 140 kg / m 3 ) was used as the skin-side material disposed on the skin side and the non-skin-side material disposed on the non-skin side. Absorbent sheets having the configurations shown in Table 1 and the structures shown in FIG. 2 (Examples 1 - 6, having two squeezing grooves), FIG. 6 (Example 7, having one squeezing groove), and FIG. 7 (Comparative Example 1, having no squeezing groove) were produced. Each of the obtained absorbent sheets was C-folded and wrapped with a spunbond nonwoven fabric (hydrophilic sheet, basis weight 12 g / m 2 ), and absorbents having dimensions of 420 mm × 150 mm were used.

[0053] In addition, an air-through nonwoven fabric (basis weight 20 g / m 2 ) was used as the liquid-permeable top sheet, a breathable polyethylene sheet (basis weight 35 g / m 2 ) was used as the liquid-impermeable back sheet, and a composite nonwoven fabric (basis weight 15 g / m 2 ) in which a spunbond nonwoven fabric / meltblown nonwoven fabric / spunbond nonwoven fabric was laminated in this order was used as the three-dimensional gathers. When integrating the top sheet, the back sheet, and the absorbent, a hot melt adhesive was used to bond the top sheet to the skin side surface of the absorbent, and absorbent articles having a longitudinal dimension of 480 mm and a width dimension of 200 mm in Examples 1 - 7 and Comparative Example 1 were produced.

[0054] The following evaluations were performed on the absorbent articles of Examples 1 - 7 and Comparative Example 1. The results are shown in Table 1. (Total Absorption Capacity) 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 mm × 100 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 load, and the time taken to absorb the 120 ml of the third injection was measured. (Backflow of liquid) After the absorption rate has been measured three times, measure the weight of the water (g) that has flowed back and been absorbed in one minute onto filter paper with a diameter of 55 mm under a load condition of 35 gf / cm after 10 minutes. 2 Under the load condition, measure the weight of the water (g) that has flowed back and been absorbed in one minute onto filter paper with a diameter of 55 mm. (Diffusion length) Measure the maximum length of the portion that has absorbed physiological saline after the absorption rate has been measured three times.

[0055] [Table 1]

[0056] From Table 1, it can be seen that by using the absorbent body obtained by C-folding the absorbent sheet of the present embodiment with a hydrophilic sheet, a thin absorbent article with good body fluid diffusibility, high levels of body fluid absorption amount and repeated absorption rate, and excellent liquid backflow prevention property can be obtained. Note that the absorbent articles of Examples 1 to 7 did not feel the rough feeling of the superabsorbent polymer before body fluid absorption, had little compressive feeling immediately after body fluid absorption, and the feeling of stiffness due to the swelling and solidification of the superabsorbent polymer was greatly alleviated, and had a very good feeling of wearing and fit.

Description of reference numerals

[0057] 10 Top sheet 12 Superabsorbent polymer 20, 20A, 20B Absorbent body 21 Polyurethane continuous porous sheet 23 Squeezing groove 24 Hydrophilic sheet 25, 25A, 25B Absorbent sheet 26 Absorbent sheet precursor 30 Backsheet 40 Three-dimensional gather 40a Elastic stretch member 40b Sheet member 50, 50A, 50B Absorbent article 60 Joint 61 Block-shaped space

Claims

1. An absorbent article comprising a liquid-permeable top sheet, a liquid-impermeable back sheet, and an absorbent body disposed therebetween, The absorbent body does not contain absorbent fibers and has an absorbent sheet, The absorbent sheet has a highly absorbent polymer enclosed between multiple layers of a polyurethane continuous porous material sheet, Between the layers of the polyurethane continuous porous body sheet, joints are provided in the surface direction between the layers to form a plurality of block-shaped spaces for encapsulating the superabsorbent polymer; the joint portion includes a frame-shaped region extending substantially linearly in the longitudinal and width directions along the outer edge of the absorbent article, and a plurality of partition regions extending substantially equally spaced apart in the longitudinal direction and substantially linearly in the width direction within the frame-shaped region, dividing the interior of the frame-shaped region into a plurality of block-shaped spaces of substantially the same size; The superabsorbent polymer is in the form of particles having a median particle size in the range of 50 μm to 600 μm, An absorbent article, wherein the absorbent sheet has band-shaped compressed grooves along the longitudinal direction.

2. The absorbent sheet has a plurality of the compressed grooves, the compressed grooves are provided so that the non-skin side of the skin-side continuous porous polyurethane sheet is in contact with or bonded to the skin side of the non-skin-side continuous porous polyurethane sheet; The absorbent article of claim 1.

3. An absorbent article as described in claim 1 or claim 2, wherein the polyurethane continuous porous sheet is a soft polyurethane foam having an expansion ratio of 10 times or more and 60 times or less.

4. The width of the compression groove is 2 mm or more and 30 mm or less.

4. The absorbent article according to claim 1, wherein the length of the compressed grooves is 20% or more and 90% or less of the length of the entire absorbent sheet.

5. 5. The absorbent article according to claim 1, wherein the depth of the compressed grooves is 10% to 80% of the thickness of the entire absorbent sheet.

6. An absorbent article as described in any one of claims 2 to 5, wherein when there are multiple compressed grooves, the superabsorbent polymer present between the compressed grooves and the superabsorbent polymer present within 20 mm of the compressed groove are fixed between multiple layers of the polyurethane continuous porous sheet.

7. The polyurethane continuous porous sheet has a basis weight of 30 g / m ２ More than 300g / m ２ and an apparent density of 100 kg / m or less ３ More than 200kg / m ３ 7. The absorbent article according to claim 1, wherein:

8. 8. The absorbent article according to claim 1, wherein the surface of the skeleton of the polyurethane continuous porous material sheet is hydrophilic.

9. The basis weight of the superabsorbent polymer in the absorbent sheet is 30 g / m ２ More than 300g / m ２ 9. The absorbent article according to claim 1, wherein:

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