Absorbent article

Abstract

Even if a polymer sheet is used as an absorbent body, an embossed part can be formed with good aesthetic property, and the function of the embossed part can be reliably exerted. A sanitary napkin (1) is provided with a polymer sheet (4) in which a superabsorbent polymer (12) is disposed between an upper sheet (10) disposed on the skin side and a lower sheet (11) disposed on the non-skin side. On the skin-side surface of the polymer sheet (4), non-continuous linear embossed sections (20) in which extruded sections (21) and non-extruded sections (22) are alternately arranged are formed along the longitudinal direction of the sanitary napkin (1). And the ratio of the length (A) of each extrusion part (21) to the length (B) of each non-extrusion part (22) is (7: 1)-(1: 1).

Description

[0001] This application is a divisional application of the application with application number "201880051782.8" (international application number: PCT / JP2018 / 032106), application date "August 30, 2018", and invention title "absorbent article". Technical Field

[0002] This invention mainly relates to absorbent articles used in sanitary napkins, panty liners, incontinence pads, medical pads, toiletries, disposable diapers, etc. More specifically, it relates to absorbent articles in which embossed portions can be aesthetically formed on absorbent articles using pulp-free absorbents. Background Technology

[0003] As absorbent articles, absorbent articles that do not contain pulp fibers and are called so-called pulp-free absorbents are known as being situated between a liquid-impermeable back sheet such as a polyethylene sheet or a polyethylene sheet laminated with nonwoven fabric, and a liquid-permeable front sheet such as a nonwoven fabric or a liquid-permeable plastic sheet.

[0004] Absorbent articles using the aforementioned polymer sheet have the following advantages: the absorbent can be made thin and the discomfort during wear can be reduced.

[0005] On the other hand, there is a technology that, for the purpose of preventing bodily fluids from spreading in the width direction or making the absorbent less prone to wrinkling and thus improving its close fit to the skin, forms embossed grooves on the skin-side surface of the liquid-permeable front sheet by heat embossing.

[0006] For example, Patent Document 1 discloses an absorbent article in which embossed grooves are continuously formed along the length direction. Patent Document 2 discloses an absorbent article in which a pair of first length embossed grooves and a pair of second length embossed grooves are continuously formed along the length direction, wherein the second length embossed grooves are positioned on the outer side of the first length embossed grooves in the width direction.

[0007] Existing technical documents

[0008] Patent documents

[0009] Patent Document 1: Japanese Patent Application Publication No. 2006-20976

[0010] Patent Document 2: Japanese Patent Application Publication No. 2015-93170 Summary of the Invention

[0011] The problem that the invention aims to solve

[0012] However, in the absorbent articles described in the aforementioned patent documents 1 and 2, since the embossing groove is continuously formed along the length of the absorbent article, there is a concern that during the processing of the embossing groove, when the absorbent article is introduced between the embossing roller and the flat roller and is extruded sequentially from one side along the length of the absorbent article, as the processing length of the embossing groove increases, the stress or strain caused by the extrusion is gradually accumulated. When a certain length is reached, the stress or strain will wrinkle or crack on the front sheet or absorbent body because there is no place to release it, thus resulting in a deterioration in the aesthetics of the embossing groove.

[0013] In particular, in absorbent articles with a pulpless absorbent body that uses a polymer sheet formed by placing a highly absorbent polymer between nonwoven fabric sheets as a body fluid absorbing component, unlike absorbent articles with a thicker absorbent body such as fibrous pulp, the stress or strain caused by the compression of pulp fibers during embossing is not easily relaxed. Therefore, this is more likely to promote wrinkling or cracking of the front sheet or absorbent body, thus further deteriorating the aesthetics of the embossed groove.

[0014] On the other hand, there is a technique that alternately arranges extruded and non-extruded sections to form a discontinuous linear embossing groove. However, when the length of the non-extruded section is short, the stress or strain associated with the embossing process of the extruded section cannot be adequately released through the non-extruded section. Due to the stress or strain accumulated over a certain length, wrinkling or cracking may occur on the front sheet or absorbent material, leading to concerns about a deterioration in the aesthetics of the embossing groove. Furthermore, when the length of the non-extruded section becomes too long relative to the length of the extruded section, bodily fluids can easily penetrate the non-extruded section and diffuse to the outer side in the width direction. Moreover, it is not easy to generate deformation along the body shape starting from the embossing section, leading to concerns about deterioration in wearability and a reduction in the function of the embossing groove.

[0015] Therefore, the main objective of this invention is to provide an absorbent article in which the embossed portion can be formed aesthetically pleasingly even when a polymer sheet is used as the absorbent, and the embossed portion can reliably function.

[0016] Methods for solving problems

[0017] To address the aforementioned issues, the present invention, as claimed in claim 1, provides an absorbent article comprising a polymer sheet, wherein a highly absorbent polymer is disposed between an upper sheet disposed on the skin side and a lower sheet disposed on the non-skin side, characterized in that, on the skin-side surface of the polymer sheet, discontinuous linear embossed portions alternately arranged with squeeze portions and non-squeeze portions are formed along the length direction of the absorbent article, wherein the ratio of the length A of each squeeze portion to the length B of each non-squeeze portion is A:B = 7:1 to 1:1.

[0018] In the invention described in claim 1, in an absorbent article comprising a polymer sheet, a discontinuous linear embossed section, alternating between squeezed portions and non-squeezed portions, is formed on the skin-side surface of the polymer sheet along the length direction of the absorbent article. In this case, the ratio of the length A of each squeezed portion to the length B of each non-squeezed portion is formed in the range of A:B = 7:1 to 1:1. Therefore, since the length B of the non-squeezed portion is formed at a certain ratio relative to the length A of the squeezed portion, the non-squeezed portion reliably functions as a relaxation portion, releasing the stress or strain accumulated due to the embossing process of the squeezed portion. Thus, excessive stress or strain accumulation is suppressed, preventing wrinkling or cracking on the front sheet and absorbent body, and enabling the embossed section to be formed with good aesthetics.

[0019] Furthermore, since the length B of the non-extrusion part is formed at a ratio of less than a specified ratio to the length A of the extrusion part, the effect of the embossed part in blocking body fluid is not significantly reduced, and the diffusion of body fluid to the outside of the width direction of the embossed part can be appropriately suppressed. Moreover, when worn, it can reliably deform from the embossed part as the starting point, resulting in good fit and wearability, and the function of the embossed part is not impaired.

[0020] As a claim 2, the present invention provides an absorbent article as claimed in claim 1, wherein an intermediate sheet is disposed between the upper sheet and the lower sheet in the polymer sheet, and the superabsorbent polymer is disposed between the upper sheet and the intermediate sheet and between the intermediate sheet and the lower sheet, respectively.

[0021] In the invention described in claim 2, an intermediate sheet is disposed between the upper and lower sheets, and a highly absorbent polymer is disposed between each sheet, thereby creating a polymer sheet composed of a 5-layer structure. By configuring the intermediate sheet, the polymer sheet becomes porous, making it easy to clearly form embossed portions.

[0022] As a claim 3, the present invention provides an absorbent article as described in claim 1 or 2, wherein the length of each of the extrusion portions is 3 to 70 mm.

[0023] In the invention described in claim 3, the length A of the extrusion portion is set to 3–70 mm. If the length A of the extrusion portion is greater than 70 mm, the stress or strain accumulated during the embossing process will become excessive, making it easy for wrinkles or cracks to occur on the front sheet or absorbent material. On the other hand, if the length A of the extrusion portion is less than 3 mm, the pressing force will be too small, making it difficult to clearly form the embossed portion and resulting in poor aesthetics.

[0024] As a claim 4, the present invention provides an absorbent article according to any one of claims 1 to 3, wherein the length of each of the non-compression portions is 0.4 to 50 mm.

[0025] In the invention described in claim 4 above, by setting the length B of the non-extruded portion to 0.4 to 50 mm, the stress or strain accumulated during the embossing process of the extruded portion can be reliably released, and the function of the embossed portion can be reliably performed.

[0026] As a claim 5, the present invention provides an absorbent article according to any one of claims 1 to 4, wherein the groove width of the extrusion portion is 2 to 10 mm.

[0027] In the invention described in claim 5 above, the groove width of the extrusion part is set to 2 to 10 mm, so that the embossed part can be clearly formed and the situation that the embossed part hardens and causes discomfort when wearing it will not occur.

[0028] The effects of the invention

[0029] As detailed above, according to the present invention, even when using polymer sheets as absorbents, embossed portions can be formed with good aesthetics and can reliably perform their function. Attached Figure Description

[0030] Figure 1 This is a partial cross-sectional view of the sanitary napkin 1 of the present invention.

[0031] Figure 2 It is along Figure 1 The arrow on line II-II in the diagram is for observation.

[0032] Figure 3 This is a cross-sectional view of polymer sheet 4.

[0033] Figure 4 This is a cross-sectional view of polymer sheet 4, a modified example.

[0034] Figure 5 This is a top view of polymer sheet 4.

[0035] Figure 6 It is along Figure 5 The arrows on the VI-VI lines are shown in the diagram.

[0036] Figure 7 This is an enlarged top view of the embossed part 20. Detailed Implementation

[0037] Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings.

[0038] (Basic structure of sanitary napkin 1)

[0039] like Figure 1 and Figure 2 As shown, the sanitary napkin 1 of the present invention is mainly composed of the following parts: a liquid-impermeable back sheet 2, which is made of polyethylene sheet or the like; a liquid-permeable front sheet 3, which allows menstrual blood to pass through quickly; a polymer sheet 4, which is located between the two sheets 2 and 3, and a highly absorbent polymer 12 is disposed in a predetermined area between the upper sheet 10 disposed on the skin side and the lower sheet 11 disposed on the non-skin side; and side nonwoven fabrics 7, 7, which are respectively disposed on both sides of the skin side surface along the length direction. Around the polymer sheet 4, at its length direction end edge, the outer edges of the liquid-impermeable back sheet 2 and the liquid-permeable front sheet 3 are joined together by an adhesive such as hot melt adhesive or by a joining means such as heat sealing or ultrasonic sealing. In addition, at its side edges, the liquid-impermeable back sheet 2 and the side nonwoven fabric 7, which extend laterally from the polymer sheet 4, are joined together by an adhesive such as hot melt adhesive or by a joining means such as heat sealing or ultrasonic sealing. A hydrophilic second sheet (not shown) may also be disposed between the liquid-permeable front sheet 3 and the polymer sheet 4 as needed.

[0040] The structure of the sanitary napkin 1 will be described in further detail below. The liquid-impermeable backing sheet 2 uses a sheet material with at least water-resistant properties, such as polyethylene or polypropylene. However, in addition to this, a non-woven fabric sheet can also be used (in which case, the liquid-impermeable backing sheet is formed by the waterproof membrane and the non-woven fabric). In recent years, there has been a tendency to appropriately use breathable sheets from the viewpoint of preventing stuffiness. As this water-resistant / breathable sheet material, a microporous sheet obtained by the following method is preferred: after molding an inorganic filler into an olefin resin such as polyethylene or polypropylene into a sheet, it is obtained by stretching in a uniaxial or biaxial direction.

[0041] Next, the liquid-permeable front sheet 3 is preferably made of porous or non-porous nonwoven fabric, or porous plastic sheet, etc. As the fabric fiber constituting the nonwoven fabric, in addition to synthetic fibers such as olefin-based fibers (e.g., polyethylene or polypropylene), polyester-based fibers, and polyamide-based fibers, regenerated fibers such as rayon or cuprammonium fiber, and natural fibers such as cotton can also be used. This allows for the production of nonwoven fabrics obtained through appropriate processing methods such as hydroentangling, spunbonding, thermal bonding, meltblowing, and needle punching. Among these processing methods, hydroentangling is superior in terms of flexibility and drape, while thermal bonding is superior in terms of bulkiness and softness.

[0042] On both sides of the skin-contact side of the sanitary napkin 1, side nonwoven fabrics 7 and 7 are provided along almost the entire length of the sanitary napkin 1. These side nonwoven fabrics 7 and 7 extend laterally, and the liquid-impermeable backing sheet 2 also extends laterally, thereby forming wing portions without absorbent material 4 on both sides of the main body. Furthermore, a portion of the laterally extending side nonwoven fabric 7 and a portion of the liquid-impermeable backing sheet 2 form outwardly protruding wing-like wings W and W. When worn, these wing-like wings W and W are positioned at the fold line RL at their base, such that they roll up the crotch area of ​​the underwear. Figure 1 It is used by folding it outwards at the wing-shaped wing W and attaching the anti-offset adhesive layer (not shown) on the outer surface of the liquid-impermeable backing sheet 2 of the wing-shaped wing W to the outer surface of the underwear, thereby preventing it from shifting relative to the underwear.

[0043] As the side nonwoven fabric 7, depending on the desired function, a water-repellent nonwoven fabric or a hydrophilic nonwoven fabric can be used. For example, if the focus is on preventing menstrual blood or vaginal discharge from seeping through, or improving skin feel, a water-repellent nonwoven fabric coated with silicone-based, paraffin-based, or alkyl chromium chloride-based water-repellent agents is preferred. Conversely, if the absorbency of the wing-shaped wings W and W's for menstrual blood is important, a hydrophilic nonwoven fabric is preferred, which is formed by swelling or making the synthetic fibers porous during the manufacturing process and applying capillary action to impart hydrophilicity. This is achieved by methods such as allowing hydrophilic compounds, such as oxidation products of polyethylene glycol, to coexist and overlap; or by treating with a metal salt such as tin tetrachloride to partially dissolve the surface and make it porous, and precipitating the metal hydroxide. To achieve welding with the liquid-permeable front sheet 3, it is preferable to blend synthetic fibers into the side nonwoven fabric 7.

[0044] (Polymer sheet 4)

[0045] like Figure 3 As shown, the polymer sheet 4 between the impermeable back sheet 2 and the permeable front sheet 3 is structured such that a superabsorbent polymer 12 is disposed between the upper sheet 10 disposed on the skin side (the permeable front sheet 3 side) and the lower sheet 11 disposed on the non-skin side (the impermeable back sheet 2 side). The polymer sheet 4 is a so-called pulp-free absorbent material that does not contain pulp fibers. The superabsorbent polymer 12 is not dispersed in fibrous materials such as pulp between the upper sheet 10 and the lower sheet 11, but is disposed as a monomeric aggregate of powdered superabsorbent polymer 12. This allows for a thinner polymer sheet 4, enabling the sanitary napkin 1 to be made thinner.

[0046] The upper sheet 10, which constitutes the skin-side layer of the polymer sheet 4, is made of porous or non-porous nonwoven fabric, crepe paper, pulp sheet, or porous plastic sheet. As the fiber fabric of the nonwoven fabric, a water-permeable fiber fabric containing chemical fibers is preferred. Specifically, similar to the liquid-permeable front sheet 3, in addition to thermoplastic synthetic fibers such as polyethylene or polypropylene (olefin-based, polyester-based, polyamide-based), these synthetic fibers may also include man-made fibers, regenerated fibers such as cuprammonium cellulose, and natural fibers such as cotton. The processing method of the nonwoven fabric is arbitrary, but to make it difficult to retain liquid, a processing method such as hot air processing, which reduces the fiber density of the resulting product, is preferred. Furthermore, to prevent the highly absorbent polymer 12 from falling off, processing methods such as spunbonding, meltblowing, and needle punching, which increase the fiber density of the resulting product, can also be used. Because the upper sheet 10 contains chemical fibers, it is difficult for the upper sheet 10 to retain liquid, resulting in good fluid permeability towards the lower layer and reducing the likelihood of bodily fluids being retained in the upper sheet 10 and flowing back towards the skin. To prevent the superabsorbent polymer 12 from detaching, it is preferable that the pore diameter of the porous plastic sheet is smaller than the average particle size of the superabsorbent polymer 12.

[0047] The weight per unit area of ​​the upper sheet 10 is 15-40 g / m². 2 Preferably, it is 18–30 g / m 2 The thickness is 0.05–0.4 mm, preferably 0.14–0.23 mm. Regarding the measurement of weight per unit area, a 20 mm × 40 mm (±2 mm) dimension is cut from the sample using a roller cutter, and the weight is measured and converted to per 1 m³. 2 The weight is taken as the weight per unit area (g / m²) 2 Furthermore, the thickness was measured using a thickness gauge (PEACOCK, dial-type thickness gauge, large type, model JB (measuring range 0-35mm)) from Ozaki Manufacturing Co., Ltd., with the sample and the thickness gauge level. The weight per unit area and thickness can be measured using the same method.

[0048] Furthermore, the lower sheet 11, which constitutes the non-skin-friendly side layer of the polymer sheet 4, can be made of a water-resistant sheet, in addition to porous or non-porous nonwoven fabric, crepe paper, pulp sheet, or porous plastic sheet. Similar to the upper sheet 10, the processing method for the nonwoven fabric is arbitrary, and can include hot air processing, spunbonding, meltblowing, needle punching, etc. To prevent the superabsorbent polymer 12 from detaching, it is preferable that the pore diameter of the porous plastic sheet is smaller than the average particle size of the superabsorbent polymer 12. The water-resistant sheet can be made of the same material as the liquid-impermeable back sheet 2.

[0049] Examples of the superabsorbent polymer 12 include, for instance, crosslinked polyacrylates, self-crosslinked polyacrylates, saponified crosslinked acrylate-vinyl acetate copolymers, crosslinked isobutylene-maleic anhydride copolymers, crosslinked polysulfonates, or crosslinked polymers formed by partially crosslinking water-swellable polymers such as polyethylene oxide and polyacrylamide. Among these polymers, acrylic or acrylate-based polymers with excellent water absorption capacity and absorption rate are preferred. For superabsorbent polymers possessing the aforementioned water absorption properties, the water absorption capacity and absorption rate can be adjusted during the manufacturing process by adjusting the crosslinking density and crosslinking density gradient.

[0050] Preferably, such as Figure 3 As shown, the superabsorbent polymer 12 is bonded to the upper sheet 10 and the lower sheet 11 respectively via an adhesive layer 14 made of hot melt adhesive or the like, disposed between the upper sheet 10 and the lower sheet 11.

[0051] As a variation of the polymer sheet 4, such as Figure 4 As shown, it can be constructed with a 5-layer structure as follows: an intermediate sheet 13 is disposed between the upper sheet 10 and the lower sheet 11, and superabsorbent polymers 12a and 12b are disposed between the upper sheet 10 and the intermediate sheet 13, and between the intermediate sheet 13 and the lower sheet 11, respectively. By providing the intermediate sheet 13, which divides the superabsorbent polymer layers into two layers, when the superabsorbent polymer absorbs water and swells, close contact between the superabsorbent polymer 12a on the upper side and the superabsorbent polymer 12b on the lower side will not occur, thus suppressing gel blockage. The intermediate sheet 13 can be made of a porous or non-porous nonwoven fabric.

[0052] Regarding the polymer sheet 4, it is preferable to have a joint portion provided in a predetermined shape for sealing the superabsorbent polymer 12 into a predetermined area between the upper sheet 10 and the lower sheet 11, thereby joining the upper sheet 10 and the lower sheet 11. That is, it is preferable to divide the polymer sheet 4 into one or more dividing regions 17 by the joint portion, and to arrange the superabsorbent polymer 12 in the dividing region 17.

[0053] The dividing region 17 can be formed in any form. For example, although not shown, it can be formed by providing a joint along the periphery of the polymer sheet 4, thereby forming a dividing region 17 covering almost the entire surface of the polymer sheet 4. Alternatively, it can be formed by further providing a grid-like joint in the middle, thereby forming a plurality of dividing regions 17 divided into a grid.

[0054] As a particularly preferred form, such as Figure 5 and Figure 6As shown, the structure can be configured such that the joints 15 and 16 that join the upper sheet 10 and the lower sheet 11 together divide the area into multiple generally elliptical regions 17, 17..., and a superabsorbent polymer 12 is disposed within each of the regions 17. In this configuration, since the polymer placement area is divided into multiple regions 17..., even if the superabsorbent polymer 12 sealed within each region 17 swells and causes each region 17 to bulge during water absorption, the surrounding joints 15 and 16 will not bulge. Therefore, the joints 15 and 16 become flow paths, and body fluids can easily diffuse even during repeated water absorption.

[0055] for Figure 5 The planar configuration of the joints 15 and 16 shown will be described in more detail. Regarding the dividing area 17, when viewed from above, the upper, lower, left, and right positions are surrounded by the first joint 15 that joins the upper layer 10 to the lower layer 11, and the inclined middle position connecting each of the first joints 15 is surrounded by the second joint 16 that joins the upper layer 10 to the lower layer 11. The dividing area 17 is arranged in a grid pattern along the length and width directions of the sanitary napkin 1.

[0056] More specifically, in the polymer sheet 4, the upper sheet 10 and the lower sheet 11 are joined together by a first joint 15 arranged in an alternating grid pattern, and by a second joint 16, wherein the second joint 16 is located at an inclined middle position connecting the four first joints 15, 15... present in the up / down and left / right positions. The alternating grid pattern arrangement means that adjacent rows or columns with equal spacing are arranged in a way that every other row or column is staggered by half a spacing, and that they are arranged in a way that every other row or column is arranged in both the up / down and left / right directions. Furthermore, in this specification, the up / down position refers to the position in the direction consistent with the length direction (front / back direction) of the sanitary napkin 1, and the left / right position refers to the position in the direction consistent with the width direction of the sanitary napkin 1.

[0057] Furthermore, a highly absorbent polymer 12 is disposed within the plurality of partitioned regions 17 in the polymer configuration region, which are surrounded by the first joint 15 and the second joint 16 and arranged in a grid pattern along the length and width directions of the sanitary napkin.

[0058] The first joint portions 15, 15, disposed at the upper and lower ends of the divided regions 17 are preferably formed as grooves that are longer in the left-right direction (the width direction of the sanitary napkin), and the first joint portions 15, 15, disposed at the left and right ends of the divided regions 17 are preferably formed as grooves that are longer in the up-down direction (the length direction of the sanitary napkin). Thus, between adjacent divided regions 17, 17, the first joint portions 15 are respectively formed as grooves that are longer in the direction of the connecting line connecting the first joint portions 15, thereby easily forming a flow path for the flow of bodily fluids between adjacent divided regions 17, 17. Furthermore, although the first joint portions 15 are preferably formed as continuous grooves, they can also be formed as discontinuous dots.

[0059] Alternatively, preferably, the second joint 16 is configured separately from the first joint 15 and is formed as a plurality of discontinuous dots in the direction connecting adjacent first joints 15, 15 to each other. The second joint 16 may be formed as discontinuous dots with a weaker bonding strength than the first joint 15, so as to preferentially peel off when the superabsorbent polymer 12 absorbs liquid and swells, but it may also be formed as a continuous groove.

[0060] The joints 15 and 16 are not formed continuously around the division area 17, but are formed intermittently with non-joints. Therefore, bodily fluids flowing into the division area 17 can easily diffuse through the non-joints to adjacent division areas 17.

[0061] The joint between the upper sheet 10 and the lower sheet 11 can be achieved by a joining method of extrusion from the outer surface of the upper sheet 10 followed by thermal fusion or ultrasonic fusion, or by a joining method based on a hot melt adhesive. In the hot melt adhesive-based bonding, it is preferable to apply the adhesive in a striped or planar pattern using any one of the following coating methods: slot coating, apex coating, or spiral coating, and to disperse granular superabsorbent polymer 12 on the adhesive.

[0062] (Embossing section 20)

[0063] In this sanitary napkin 1, such as Figure 1 and Figure 7 As shown, on the skin-side surface of the polymer sheet 4, a discontinuous linear embossed portion 20 is formed along the length direction of the sanitary napkin 1, consisting of alternating squeeze portions 21 and non-squeeze portions 22.

[0064] The embossed portion 20 can be formed by pressing from the skin side of the liquid-permeable front sheet 3 to the polymer sheet 4, causing the entire component from the liquid-permeable front sheet 3 to be integrally recessed towards the non-skin side, or it can be formed by pressing from the skin side of the polymer sheet 4, causing only the polymer sheet 4 to be recessed towards the non-skin side.

[0065] The compression portion 21 is formed by indenting into the non-skin side under a certain pressure. That is, for the compression portion 21, instead of applying embossing with different depths on the bottom surface as in high compression portions and low compression portions, they are all formed at a fixed depth. In this sanitary napkin 1, the polymer sheet 4 does not have the thickness of a fiber-staple absorbent core, therefore, it is difficult to create a difference between high compression portions and low compression portions, and there is a concern that the embossed portion 20 cannot be clearly formed.

[0066] The non-compression portion 22 is the portion where no compression from the skin side is applied, and it is a gap provided between adjacent compression portions 21, 21. The non-compression portion 22 can be formed to approximately the same height as the area other than the embossed portion 20, or it can be formed to be slightly recessed towards the non-skin side due to the influence of the compression portion 21. Preferably, multiple compression portions 21 and non-compression portions 22 are provided along the length direction of the sanitary napkin 1. This ensures that the function of the discontinuous linear embossed portion 20 can be reliably performed.

[0067] The ratio of the length A of each extruded portion 21 to the length B of each non-extruded portion 22 is formed in the range of A:B = 7:1 to 1:1, preferably 7:1 to 2:1, and more preferably 6:1 to 4:1. The lengths A and B are lengths along the direction in which the embossed portion 20 extends, such as... Figure 7 As shown, when the embossed portion 20 is formed in a curved shape, the length (arc length) is along the curve. The length B of the non-extruded portion 22 can be set as the length along the extension line from the extruded portions 21, 21 at adjacent ends toward the non-extruded portion 22. Preferably, the extruded portions 21... and the non-extruded portions 22... formed along the embossed portion 20 are each formed to approximately the same length throughout the entire embossed portion 20.

[0068] In this sanitary napkin 1, since the length B of the non-compression portion 22 is formed at a certain ratio to the length A of the compression portion 21, the non-compression portion 22 reliably functions as a relaxed portion. This relaxed portion releases the stress or strain accumulated due to the embossing process of the compression portion 21, thereby suppressing excessive stress or strain accumulation. Therefore, wrinkling or cracking does not occur on the liquid-permeable front sheet 3 and the polymer sheet 4, and the embossed portion 20 can be formed aesthetically. When the length A of the compression portion 21 is more than 7 times the length B of the non-compression portion 22, the compression portion 21 becomes excessively long, and the stress or strain associated with the embossing process of the compression portion 21 easily accumulates. When the accumulated stress or strain reaches a certain level, wrinkling or cracking will occur on the upper sheet 10 and lower sheet 11 of the liquid-permeable front sheet 3 or the polymer sheet 4. On the other hand, in order to release the stress caused by the embossing process of the extrusion portion 21, the non-extrusion portion 22 can be formed with a length longer than the extrusion portion 21. However, as explained below, in order to ensure the function of the embossing portion 20, it is preferable to form the non-extrusion portion 22 in a certain proportion.

[0069] In the embossed portion 20, since the length B of the non-compression portion 22 is formed at a ratio equal to or less than the length A of the compression portion 21, the effect of the embossed portion 20 in blocking bodily fluids is not significantly reduced. This effectively suppresses the diffusion of bodily fluids outwards in the width direction of the embossed portion 20. Furthermore, when worn, the sanitary napkin 1 can reliably deform from the embossed portion 20, resulting in a good fit and comfortable wear, without compromising the function of the embossed portion 20. Conversely, if the length B of the non-compression portion 22 is made longer than the length A of the compression portion 21, the amount of bodily fluids diffusing through the non-compression portion 22 to the width direction of the embossed portion 20 increases, raising concerns about side leakage. Furthermore, since the length B of the non-compression portion 22 is larger than the length A of the compression portion 21, deformation of the sanitary napkin starting from the embossed portion 20 is difficult to occur between adjacent compression portions 21, 21. At the non-compression portion 22, it will bend in an unexpected direction, making it difficult to fit the body shape and raising concerns about poor wearability. In particular, in this sanitary napkin 1, since a polymer sheet 4 is used as the absorbent, when embossed portions extending along the length direction are formed on both sides of the body fluid discharge portion H by continuous compression portions, the diffusion of body fluid to the outside in the length direction is blocked by the embossed portions, and gel blockage caused by body fluid retention is likely to occur near the body fluid discharge portion H. However, in the embossed portion 20 of the present invention, since it is formed as a discontinuous line with the compression portion 21 and the non-compression portion 22 arranged in a prescribed ratio, body fluid can appropriately diffuse to the outside in the width direction of the embossed portion 20, thereby making it difficult for gel blockage to occur near the body fluid discharge portion H.

[0070] Furthermore, by providing the non-squeezable portion 22, the flow of bodily fluid along the squeeze portion 21 can be intermittently interrupted, thereby suppressing excessive diffusion of bodily fluid along the embossed portion 20. In contrast, when the squeeze portion is continuously formed without providing the non-squeezable portion, bodily fluid is more likely to diffuse only along the embossed portion compared to other areas. As a result, users of used sanitary napkins may experience concerns such as whether leakage will occur from the end of the absorbent core or whether the absorbency of the sanitary napkin is insufficient.

[0071] The length A of each of the extrusion portions 21 can be 3 to 70 mm, preferably 5 to 20 mm. If the length A of the extrusion portion 21 is greater than 70 mm, the stress or strain accumulated during the embossing process will become too large, which will easily cause wrinkling or cracking of the liquid-permeable front sheet 3 or polymer sheet 4. On the other hand, if the length A of the extrusion portion 21 is less than 3 mm, the pressing force of the embossed portion 20 will be smaller, making it difficult to clearly form the embossed portion 20 and resulting in poor aesthetics.

[0072] The length B of the non-compression portion 22 can be 0.4 to 50 mm, preferably 0.7 to 20 mm. If the length B of the non-compression portion 22 is less than 0.4 mm, the stress or strain accumulated during the compression of the compression portion 21 cannot be reliably released. Furthermore, if the length B of the non-compression portion 22 is greater than 50 mm, there is a concern that bodily fluids may easily penetrate and diffuse through the non-compression portion 22, thereby reducing the function of the embossed portion 20.

[0073] The groove width (width at the bottom of the groove) of the compression portion 21 can be 2 to 10 mm, preferably 2 to 6 mm. This allows for the clear formation of the embossed portion 20 without causing it to harden and resulting in discomfort when worn.

[0074] Preferably, the two ends of the extrusion section 21 are formed into an arc shape, with the ends of the two side walls connected to each other by an outwardly bulging arc. This prevents the liquid-permeable front sheet 3 and the polymer sheet 4 from cracking at the ends of the extrusion section 21. The arc is preferably a semicircle with a radius of half the width of the groove of the extrusion section 21 (with the groove width as the diameter).

[0075] Table 1 shows the results of a relative evaluation of the adhesive strength, aesthetics, and hardness of the embossed portion 20 when the groove width of the extrusion portion 21 is varied. Table 2 shows the results of a relative evaluation of the adhesive strength, aesthetics, and hardness of the embossed portion 20 when the length A of the extrusion portion 21 is varied. The evaluations are expressed as follows: ×: poor; ○: good; ◎: very good.

[0076] [Table 1]

[0077]

[0078] [Table 2]

[0079]

[0080] Preferably, such as Figure 1 As shown, on both sides of the body fluid discharge portion H, one embossed section 20 is formed in a left-right pair. The embossed section 20 is preferably formed within a predetermined length including the body fluid discharge portion H, and more specifically, preferably within a length longer than the base length of the wing-like protective wings W on both sides. Thus, body fluid that can diffuse from the body fluid discharge portion H to both sides in the width direction can be reliably blocked by the embossed sections 20, 20.

[0081] exist Figure 1 In the example shown, the left and right paired embossed portions 20 are formed by arcs bulging outward in the width direction, but they can also be formed by straight lines extending in the length direction of the sanitary napkin 1 or arcs bulging inward in the width direction. As long as they are formed along the approximate length direction of the sanitary napkin 1, they can be any shape.

[0082] Furthermore, one embossed portion 20 is formed on each side of the fluid discharge portion H, but multiple portions, two or more, can also be formed. When multiple portions are formed, adjacent embossed portions 20 can be arranged such that the squeezing portion 21 and the non-squeezing portion 22 are arranged in the width direction of the sanitary napkin 1, or the squeezing portion 21 and the non-squeezing portion 22 can be arranged alternately. In the latter case, the effect of blocking fluid that diffuses outwards in the width direction through the non-squeezing portion 22 is improved, and therefore this is the preferred configuration.

[0083] Regarding the aforementioned paired embossed portions 20, 20, it can be as follows: Figure 1 The front and back ends are separated as shown. Although not illustrated, embossed sections can also be provided to connect the front ends to each other and / or the back ends to each other.

[0084] Alternatively, a figurative embossing portion 23 may be provided separately from the paired embossing portions 20 and 20 at a position further forward and / or rearward than the paired embossing portions 20, 20, and at the center of the width direction. Figure 1In the example shown, the embossed portion 23 is formed in the shape of a ribbon, but it can also be other shapes such as hearts or stars, or geometric patterns such as circles or lines. The embossed portion 23 can also be formed in the same way as the embossed portion 20, as a discontinuous line with alternating extruded and non-extruded portions, or it can be formed as a continuous line with continuous extruded portions. When formed as a discontinuous line, the embossed portion can be formed with good aesthetics, and therefore it is the preferred form.

[0085] To impart the embossed portion 20, it can be done by: inserting a laminate formed by layering the liquid-permeable front sheet 3 onto the skin-side surface of the polymer sheet 4 between an embossing roller and a flat roller, wherein the embossing roller has a protrusion corresponding to the extrusion portion 21 of the embossed portion 20, and the liquid-permeable front sheet 3 and the polymer sheet 4 are joined together by heating and pressing at positions corresponding to the protrusions of the embossing roller.

[0086] Label Explanation

[0087] 1: Sanitary napkin; 2: Liquid-impermeable back sheet; 3: Liquid-permeable front sheet; 4: Polymer sheet; 7: Side non-woven fabric; 10: Top sheet; 11: Bottom sheet; 12: Superabsorbent polymer; 13: Middle sheet; 14: Adhesive layer; 20: Embossed part; 21: Extruded part; 22: Non-extruded part.

Claims

1. An absorbent article provided with a polymer sheet having a superabsorbent polymer disposed between an upper sheet disposed on a skin side and a lower sheet disposed on a non-skin side, characterized in that on a surface of the polymer sheet on the skin side, discontinuous linear embossed portions in which pressed portions and unpressed portions are alternately disposed are formed along a length direction of the absorbent article, a ratio of a length A of each of the pressed portions to a length B of each of the unpressed portions is A:B = 7:1 to 1:1, a left and right pair of the embossed portions is formed on both sides of a body fluid discharge site, both ends of the pressed portion are formed in a circular arc shape in which both side walls of the pressed portion are connected to each other by a circular arc line bulging outward, the left and right embossed portions are formed in a circular arc shape bulging outward in a width direction.

2. The absorbent article according to claim 1, wherein the length of each of the unpressed portions is 0.7 mm to 20 mm.

3. The absorbent article according to claim 1, wherein the ratio of the length A of each of the pressed portions to the length B of each of the unpressed portions is a constant ratio.

4. The absorbent article according to claim 1, wherein the length of each of the unpressed portions is 0.4 mm to 50 mm.

5. The absorbent article according to claim 1, wherein the length of each of the pressed portions is 3 mm to 70 mm.

6. The absorbent article according to claim 1, wherein the length of each of the unpressed portions is 0.4 mm to 50 mm, the length of each of the pressed portions is 3 mm to 70 mm, the ratio of the length A of each of the pressed portions to the length B of each of the unpressed portions is a constant ratio.

7. The absorbent article according to claim 1, wherein at least one of the lower sheet constituting a non-skin side layer of the polymer sheet and the upper sheet constituting a skin side layer of the polymer sheet is formed of a nonwoven fabric with or without holes.

8. The absorbent article according to claim 1, wherein the polymer sheet is divided into divided regions by a joint portion in which the superabsorbent polymer is disposed.

9. The absorbent article according to claim 1, wherein the polymer sheet is configured to provide a joint portion that joins the upper sheet and the lower sheet for enclosing a prescribed region of the superabsorbent polymer between the upper sheet and the lower sheet in a prescribed form.

10. The absorbent article according to claim 1, wherein the polymer sheet is configured to provide a joint portion that joins the upper sheet and the lower sheet for enclosing a prescribed region of the superabsorbent polymer between the upper sheet and the lower sheet in a prescribed form, the polymer sheet is divided into divided regions by the joint portion in which the superabsorbent polymer is disposed.

11. The absorbent article according to claim 1, wherein the superabsorbent polymer exists as an aggregate of particles of the superabsorbent polymer.

12. The absorbent article according to claim 1, wherein the pressed portions are all formed at a fixed depth, each of the non-pressed portions has a length of 0.4 mm to 50 mm, each of the pressed portions has a length of 3 mm to 70 mm, a ratio of the length A of each of the pressed portions to the length B of each of the non-pressed portions is a certain ratio.

13. The absorbent article according to claim 1, wherein the polymer sheet is configured to provide a joining portion that joins the upper sheet and the lower sheet, for enclosing the superabsorbent polymer in a prescribed region between the upper sheet and the lower sheet, the polymer sheet is divided by the joining portion into a divided region in which the superabsorbent polymer is disposed, a side nonwoven fabric is provided on a skin-contacting surface side of the absorbent article, the absorbent article has a liquid-impermeable back sheet, a wing-shaped flaps that protrude outward are formed by a portion of the side nonwoven fabric that extends laterally and a portion of the liquid-impermeable back sheet that extends laterally.

14. The absorbent article according to claim 1, wherein the circular arc line is a semicircular arc having a length of half the groove width of the pressed portion as a radius.

15. The absorbent article according to claim 1, wherein the circular arc line is a semicircular arc having a length of half the groove width of the pressed portion as a radius, and is configured to prevent a liquid-permeable front sheet of the absorbent article and the polymer sheet from being broken at an end portion of the pressed portion.

16. The absorbent article according to claim 1, wherein the embossed portions on the left and right are formed in a circular arc shape that bulges outward in a width direction of the absorbent article.

17. The absorbent article according to claim 1, wherein each of the non-pressed portions has a length of 0.4 mm to 50 mm, each of the pressed portions has a length of 3 mm to 70 mm, a ratio of the length A of each of the pressed portions to the length B of each of the non-pressed portions is a certain ratio, the embossed portions on the left and right are formed in a circular arc shape that bulges outward in a width direction of the absorbent article.

18. The absorbent article according to claim 1, wherein the embossed portions on the left and right are formed in a circular arc shape that bulges outward in a width direction of the absorbent article at a central portion of the embossed portions.

19. The absorbent article according to claim 1, wherein the embossed portions on the left and right are formed in a circular arc shape that bulges outward in a width direction of the absorbent article at a central portion of the embossed portions.

20. The absorbent article according to claim 1, wherein the absorbent article further has: a liquid-impermeable back sheet; a liquid-permeable front sheet; and a side nonwoven fabric disposed on both side portions of a skin side surface of the polymer sheet and extending in a length direction of the absorbent article, the polymer sheet is disposed between the liquid-impermeable back sheet and the liquid-permeable front sheet, at a peripheral portion of the polymer sheet, an outer edge portion of the liquid-impermeable back sheet and an outer edge portion of the liquid-permeable front sheet are joined at an end edge portion in a length direction of the polymer sheet, at a side edge portion of the polymer sheet, a portion of the liquid-impermeable back sheet that extends laterally beyond the polymer sheet is joined to the side nonwoven fabric.

21. The absorbent article according to claim 1, wherein the absorbent article further comprises: a liquid-impermeable back sheet; a liquid-permeable front sheet; and a side nonwoven fabric disposed on both side portions of the skin-facing surface of the polymer sheet and extending in the length direction of the absorbent article, the polymer sheet is disposed between the liquid-impermeable back sheet and the liquid-permeable front sheet, at the end edge portion of the polymer sheet in the length direction of the polymer sheet, the outer edge portion of the liquid-impermeable back sheet and the outer edge portion of the liquid-permeable front sheet are joined by an adhesive or a joining means of heat sealing or ultrasonic sealing, at the side edge portion of the polymer sheet, the portion of the liquid-impermeable back sheet that extends laterally beyond the polymer sheet and the side nonwoven fabric are joined by an adhesive or a joining means of heat sealing or ultrasonic sealing.

22. The absorbent article according to any one of claims 1 to 21, wherein in the polymer sheet, an intermediate sheet is disposed between the upper sheet and the lower sheet, and the superabsorbent polymer is disposed between the upper sheet and the intermediate sheet and between the intermediate sheet and the lower sheet, respectively.

23. The absorbent article according to any one of claims 1 to 21, wherein the groove width of the pressed portion is 2 mm to 10 mm.

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