Absorber and absorbent article

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 fluids do 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 absorbent pads, sanitary napkins, and paper diaper products such as pant-type paper diapers and tape-fastened type paper diapers. There are various forms depending on 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, which 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 leakage 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, Figure 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 absorption layer (a nonwoven fabric disposed on the skin side) and a lower absorption layer disposed opposite to the non-skin side of the upper absorption 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 absorption layer being substantially vertically long, and the central portion in the width direction of the lower absorption layer having a smaller distribution amount of the superabsorbent polymer than other portions of the lower absorption layer (Figure 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 in the lower absorption layer and optimizing the distribution of the superabsorbent polymer, it is possible to maintain high liquid diffusibility and liquid retention 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 the absorbent article is made thinner by using an absorbent sheet as the absorber, when the absorbent article is made thinner and lighter 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 thin absorbent articles using a conventional absorbent sheet as the 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 lump, 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 a large difference in liquid permeability between the non-woven fabric that is the upper absorbent layer and the hydrophilic porous body that 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 that is excellent in body fluid diffusibility, has high-level absorption performance, absorption rate, and backflow prevention performance, and is also excellent in wearing feeling 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. By partially joining the multiple layers to form an absorbent sheet and providing a strip-shaped squeezing groove on the skin side surface of the absorbent sheet in plan view, 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 therebetween, 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 a strip-shaped squeezing groove along the longitudinal direction, the absorbent article. (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 existing between the squeezing grooves when there are a plurality of the squeezing grooves and the superabsorbent polymer existing 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 a bulk density of 100 kg / m 3 or more and 200 kg / m 3 or less. The absorbent article according to any one of the above (1) to (6). (8) The polyurethane continuous porous sheet has a hydrophilic skeleton surface. The absorbent article according to any one of the above (1) to (7). (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 the above (1) to (8).

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 anti-backflow property, 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 before and after the absorption of 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 perpendicular 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 fluids in the absorber 20. FIGS. 6 and 7 show the 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. For example, it includes 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 preferably 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) of the absorbent article 50 in the longitudinal direction and the width direction 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 within 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 to 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 a joint portion 60 in a strip shape in plan view that partially joins the multi-layers of the polyurethane continuous porous sheet 21 is 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 to 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 joint portion 60, the multi-layers are divided into block-shaped spaces 61, the superabsorbent polymer 12 is encapsulated 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, by using the polyurethane continuous porous sheet 21 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 by the squeezing groove 23 significantly improving the body fluid diffusibility of the entire absorbent sheet 25, the occurrence of lateral leakage, backflow, etc. of the body fluid is significantly suppressed. Second, by dividing the multi-layers of the polyurethane continuous porous sheet 21 into a plurality of block-shaped spaces 61 for encapsulating the superabsorbent polymer 12 and further 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 it 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 in particular, 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 sense of compression is dispersed due to being divided into block-shaped spaces. After the body fluid is absorbed, the superabsorbent polymer 12 swells and solidifies, and the feeling of stiffness is alleviated. 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 can be kept more uniform 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, by suppressing the swelling after the body fluid is absorbed, in particular, the absorption rate does not decrease during repeated absorption, the amount of backflow is small, the body fluid diffuses excellently, 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 top sheet 10, an absorber 20, and a back sheet 30 as basic constituent units. As needed, 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 top sheet 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 top sheet 10, the absorber 20, the back sheet 30, and the three-dimensional gathers 40.

[0022] <Top sheet> The top sheet 10 is a liquid-permeable sheet-like base material that allows body fluids to quickly pass through toward the absorber 20. The top sheet 10 preferably has a soft feel and does not irritate the skin so that it can contact the wearer's skin. 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 an apertured 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-bonded nonwoven fabric, a spunlace nonwoven fabric, a spunbond nonwoven fabric, etc. made of 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-bonded nonwoven fabrics, spunbond nonwoven fabrics, etc. are more preferred.

[0023] From the viewpoint of improving liquid permeability, the top sheet 10 may be embossed or perforated on the surface. From the viewpoint of reducing irritation to the skin, the top sheet 10 may contain one or more of a lotion, an antioxidant, an anti-inflammatory component, a pH adjuster, an antibacterial agent, a moisturizing agent, etc. The basis weight of the top sheet 10 is, for example, 18 g / m 2 to 400 g / m 2 in the following range. The shape of the top sheet 10 is not particularly limited, and any shape that covers part or all of the absorber 20 and is necessary to guide body fluids 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 width 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. 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 width dimensions of the ventral side and the dorsal side 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 width dimension of the crotch part that contacts the crotch of the wearer is in the range of 90 mm or more and 250 mm or less. Embossing may be applied to 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 part in the width direction, and after adhering them as necessary, 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 part is adhered 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 the absorbent sheet 25 may be wrapped so that a slit-shaped space extending in the longitudinal direction is formed with both ends in the width direction of the hydrophilic sheet 24 facing each other while being separated between the top sheet 10 and the absorbent sheet 25.

[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 bond 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 bond non-woven fabric, spunbond non-woven fabric, air-through non-woven fabric, pulp-containing non-woven fabric, etc. 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, etc. Utilizing this characteristic, as shown in FIG. 5, the body fluid that has invaded into 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. In addition, when the body fluid that has passed through the top sheet 10 permeates into 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 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, for example, uniformly diffuses the body fluid that has passed through the topsheet 10 throughout the absorber 20 (absorbent sheet 25). The polyurethane continuous porous sheet 21 also has flexibility, which alleviates the feeling of roughness of the particles of the superabsorbent polymer 12 before body fluid absorption, and alleviates the jelly-like compressive feeling generated when the superabsorbent polymer 12 swells after body fluid absorption, and the feeling of stiffness after absorbing the body fluid and swelling and hardening. Therefore, the wearing comfort of the absorbent article 50 is greatly improved.

[0029] The flexible polyurethane foam can be obtained, for example, by mixing raw material compounds such as polyol and polyisocyanate, additives such as a foaming agent, a foam stabilizer, and a catalyst, 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 type of raw material compound, the type and addition amount of the additive, 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, average 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 manufactured 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 selected from the range of 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 from the viewpoints of the mechanical strength of the entire absorber 20, prevention of slippage of the absorber 20 after body fluid absorption, flexibility, etc.

[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 using, for example, a "height gauge" (manufactured by Mitutoyo Corporation).

[0032] The skeleton surface of the soft polyurethane foam contained in the polyurethane continuous porous sheet 21 may be hydrophilic or hydrophobic, but from the viewpoint of the ease of wetting with body fluids and the like, in a preferred embodiment, the skeleton surface 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 skeleton surface 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 multiple layers of the polyurethane continuous porous sheet 21, the polyurethane continuous porous sheets 21 on the skin side and the non-skin side are partially joined, and a joining portion 60 is provided to form a plurality of block-shaped spaces 61 for enclosing the superabsorbent polymer 12 in the plane direction between the multiple layers. The joining 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 of the absorbent article 50 in the vicinity of the outer edge, 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, dividing 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 of the joining portion 60, the number and arrangement in the longitudinal and width directions, etc. are appropriately selected according to the amount of the superabsorbent polymer 12 enclosed in the block-shaped space 61, the method of forming the joining 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 joining portion 60 may be configured to include, 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 arranged in parallel in the longitudinal direction and are closed spaces surrounded by the joining portion 60 on all sides, 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 and swollen with body fluid 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 the absorption rate and absorption amount is significantly reduced. In the present embodiment, the shape of the block-shaped space 61 provided between the multiple layers of the polyurethane continuous porous sheet 21 is substantially rectangular in plan view, but is not limited thereto, and can be various shapes such as a triangle (especially an equilateral triangle), a hexagon (especially a regular hexagon), a circle, a concentric circle, etc.

[0035] (Superabsorbent polymer) The superabsorbent polymer 12 is not particularly limited as long as it can absorb body fluids and prevent backflow, and examples thereof include polyacrylate salts, polyaspartate salts, (starch-acrylic acid) graft copolymers, (acrylic acid-vinyl alcohol) copolymers, (isobutylene-maleic anhydride) copolymers, and saponified products thereof. Among these, from the viewpoint of the absorption amount per unit weight, polyacrylate salts are preferable, alkali metal polyacrylate salts are more preferable, and sodium polyacrylate is even more preferable. The superabsorbent polymer 12 can be used alone or in combination of two or more.

[0036] The superabsorbent polymer 12 is used, for example, in the form of particles, fibers, etc., but is preferably used in the form of particles from the viewpoint of ease of handling. 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 hardening of the absorber 20 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 higher and 180 °C or lower can be used without particular limitation. Examples thereof 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 application method of the hot melt adhesive, known methods such as the curtain coating method, the spiral method, and the slot method for applying the molten hot melt adhesive from a nozzle in a non-contact manner or in a contact manner can be used. The content of the hot melt adhesive is, for example, 10 g / m from the viewpoint of not impairing the absorbency of the superabsorbent polymer 12 and the feel on the skin during wearing.2 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. It is provided so as to be in contact with or joined to 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 the joint portion 60 extending in the longitudinal direction, a second form formed near the boundary between the joint portion 60 extending in the longitudinal direction and the block-shaped space 61 along it, and a third form formed so as to penetrate the plurality of block-shaped spaces 61 connected in the longitudinal direction in the longitudinal direction. However, 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. In addition, 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 in the longitudinal direction of the absorbent sheet 25 to the other middle part, 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 measurement values to obtain 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 multi-layers of the polyurethane continuous porous sheet 21 (or within the block-shaped space 61). In this embodiment, such a superabsorbent polymer 12 is fixed within the multi-layers (or within the block-shaped space 61). Further, regardless of the number of squeezing grooves 23 that the absorbent sheet 25 has, 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 multi-layers (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, during the period 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 rate and absorption amount is reliably prevented. Also, when the wearer of the absorbent article 50 loses the balance of 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-and-down directions in the front-back, left-right directions, 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 rate 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 non-skin side surface of the polyurethane continuous porous sheet 21 disposed on the skin side with the skin side surface of the polyurethane continuous porous sheet 21 on which the superabsorbent polymer 12 is sprayed or fixed on the non-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 absorbent sheet 25 can be produced by a manufacturing method including these steps. 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 that 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 its manufacturing method. Examples include single-layer non-woven fabrics such as spunbond non-woven fabrics and meltblown non-woven fabrics, composite non-woven fabrics such as spunbond non-woven fabric / meltblown non-woven fabric laminates and spunbond non-woven fabric / meltblown non-woven fabric / spunbond non-woven fabric laminates, and composite materials thereof. Examples of the resin film include polyester, polyvinyl alcohol, polyethylene, polypropylene, and composite films 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. Note that calcium carbonate can be cited as the filler, and the blending method can be carried out without limitation by known methods.

[0046] <Three-dimensional gather> The three-dimensional gather 40 is 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 gather 40 includes 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 part 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. As the nonwoven fabric for the first sheet member, any water-repellent and / or waterproof (liquid-impermeable) nonwoven fabric made of hydrophobic fibers can be used without any particular limitation, 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 stretchable member 40a, for example, thread-, string- or band-shaped members made of natural rubber, synthetic rubber, polyurethane or the like can be appropriately used.

[0049] <Method of manufacturing absorbent articles> The absorbent article 50 can be manufactured by a known manufacturing method, for example, a manufacturing method including a step of arranging the absorbent body 20 between the top sheet 10 and the back sheet 30, a step of 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 a step of 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 may be individually wrapped in a package and then folded in thirds in the longitudinal direction. Leg gathers, waist gathers, side flaps, and the like may be provided as necessary.

[0050] Although the present invention has been described above using the 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 is clear to those skilled in the art that various modifications and improvements can be made to the above embodiments. In addition, it is clear from the description of the claims that forms with such modifications or improvements can also be included in the technical scope of the present invention. EXAMPLES

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

[0052] (Examples 1 to 7 and Comparative Example 1) (Production of Absorbent Articles) As the skin-side material disposed on the skin side and the non-skin-side material disposed on the non-skin side, 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, and absorbent sheets having the configurations shown in Table 1 and the structures shown in Fig. 2 (Examples 1 to 6, having 2 squeezing grooves), Fig. 6 (Example 7, having 1 squeezing groove), and Fig. 7 (Comparative Example 1, having no squeezing groove) were produced. Each of the obtained absorbent sheets was used as an absorber having dimensions of 420 mm × 150 mm, which was C-folded and wrapped with a spunbond nonwoven fabric (hydrophilic sheet, basis weight 12 g / m 2 ).

[0053] Also, 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 absorber, a hot melt adhesive was used to join the top sheet and the skin side surface of the absorber, and absorbent articles having a longitudinal dimension of 480 mm and a width dimension of 200 mm for Examples 1 to 7 and Comparative Example 1 were produced.

[0054] The following evaluations were performed on the absorbent articles of Examples 1 to 7 and Comparative Example 1. The results are shown in Table 1. (Total Absorption Capacity) After immersing in physiological saline for 5 minutes, draining water on a wire mesh for 30 seconds, and measuring the weight difference before and after absorption. (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 120 ml of the third injection was measured. Backflow of liquid After measuring the absorption rate three times, measure the weight (g) of the water absorbed in reverse in 1 minute on 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 (g) of the water absorbed in reverse in 1 minute on filter paper with a diameter of 55 mm. (Diffusion length) Measure the maximum length of the part that has absorbed physiological saline after measuring the absorption rate three times.

[0055]

Table 1

[0056] From Table 1, it can be seen that by using the absorber obtained by C-folding the absorbent sheet of this 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. In addition, the absorbent articles of Examples 1 to 7 did not feel the rough feeling of the superabsorbent polymer before absorbing body fluid, had little compressive feeling immediately after absorbing body fluid, and had a significantly reduced feeling of stiffness due to the swelling and solidification of the superabsorbent polymer, and had a very good wearing feeling and fit.

Explanation of symbols

[0057] 10 Top sheet 12 Superabsorbent polymer 20, 20A, 20B Absorber 21 Polyurethane continuous porous sheet 23 Squeezing groove 24 Hydrophilic sheet 25, 25A, 25B Absorbent sheet 26 Absorbent sheet precursor 30 Back sheet 40 Three-dimensional gather 40a Elastic stretch member 40b Sheet member 50, 50A, 50B Absorbent article 60 Joint part 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; An absorbent article, wherein the absorbent sheet has band-shaped compressed grooves along the longitudinal direction.

2. 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, the layers of the polyurethane continuous porous material sheet are bonded together to form a block-shaped space in which the superabsorbent polymer is enclosed; The absorbent sheet has a plurality of band-shaped compressed grooves along the longitudinal direction, 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; An absorbent article characterized by:

3. 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, The continuous porous polyurethane sheet is a flexible polyurethane foam having an expansion ratio of 10 to 60 times, the layers of the polyurethane continuous porous material sheet are bonded together to form a block-shaped space in which the superabsorbent polymer is enclosed; An absorbent article, wherein the absorbent sheet has band-shaped compressed grooves along the longitudinal direction.

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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