Disposable diapers

Abstract

To provide a disposable diaper especially for a wearer of a high urination volume.SOLUTION: In a disposable diaper in which an absorption element 50 having an absorber 56 using cotton-like pulp as a main constituent and a high absorbent polymer is interposed between a liquid permeable top sheet 30 and a liquid impermeable sheet 11, an intermediate sheet 40 having a front end in a position separated by 5 to 50 mm from an abdominal side front end of the absorber 56 toward a crotch side is arranged at least in a front body and is interposed between the top sheet 30 and the absorption element 50. The intermediate sheet 40 is an air-through non-woven fabric having a basis weight of 30 g / m2 or more and a thickness of 3 to 8 mm.SELECTED DRAWING: Figure 8

Description

[Technical Field]

[0001] This invention relates to disposable diapers. [Background technology]

[0002] Due to underdeveloped bladder development or insufficient nocturnal secretion of antidiuretic hormone (which suppresses urine production), some people continue to wet the bed at night even after the age of five (approximately 800,000 people in Japan). In patients with nocturnal enuresis, if the cause is insufficient nocturnal secretion of antidiuretic hormone, a large amount of urine is produced in the bladder even at night. Since the bladder capacity increases with growth, if the amount of urine produced exceeds the bladder capacity, a large amount of urine is urinated at once.

[0003] Normally, people with nocturnal enuresis use diapers at night, but if they are sleeping face down when they urinate, the absorbent material can only be used on the front side. This presents a problem where the amount and speed of absorption cannot keep up with the volume and speed of urination, making leakage very likely. To address the above issues, it is common to use highly diffusive materials such as air-through nonwoven fabrics for the surface material (top sheet or second sheet) or to provide slits in the absorbent material. However, when sleeping face down, gravity prevents diffusion to the back side of the absorbent material, making it difficult to improve the absorption speed.

[0004] Patent Document 1 (Patent No. 3949020) describes an absorbent article with a thickness of 1.5 mm to 4 mm that uses an intermediate sheet (so-called second sheet) of 0.8 to 2 mm, with the intermediate sheet being the thickest part. Based on this structure and scope of disclosure, it is thought that the invention described in Patent Document 1 is intended for use as a sanitary napkin. [Prior art documents] [Patent Documents]

[0005] [Patent Document 1] Patent No. 3949020 [Overview of the project] [Problems that the invention aims to solve]

[0006] Therefore, the main objective of the present invention is to provide a disposable diaper, particularly for wearers with a large volume of urine output. Another challenge is to provide a disposable diaper that can prevent or suppress leakage even when the baby is sleeping face down. [Means for solving the problem]

[0007] The following disposable diapers solve the above problems. <Basic philosophy> The basic idea of ​​this invention is to create a disposable diaper that prevents leakage, for example, when sleeping face down, by making the intermediate sheet (second sheet) bulky and less prone to liquid flow (i.e., more likely to retain liquid), and by placing it in front of the absorbent, quickly draws in (retains) urine, transfers it to the absorbent directly below, and diffuses it within the absorbent, thereby preventing or suppressing leakage when sleeping face down.

[0008] <Basic configuration> Between the permeable top sheet and the liquid-impermeable sheet is a layer primarily composed of cotton-like pulp, with a thickness of 3-10 mm and a basis weight of 130-250 g / m². 2 It has an inner body with an absorbent element having an absorbent material and a superabsorbent polymer interposed therebetween, and an outer body provided on the back side thereof, Front of the garment Both sides of the exterior body The outer body on both sides of the back is joined together. Side seal section is formed So along These are disposable pant-type diapers with waist and leg openings. The absorbent body 、 From the front of the body, through the crotch, to the back of the body, An intermediate sheet, narrower than the absorbent, is interposed between the permeable top sheet and the absorbent element. The front end of the intermediate sheet is located 5 to 50 mm below the crotch from the ventral front end of the absorbent material. The longitudinal length of the intermediate sheet is in the range of 40 to 70% of the absorber length, Both side edges of the intermediate sheet are on the center side in the width direction from both side edges of the absorber, The intermediate sheet The fiber thickness is 2.0 to 10 dtex. has a basis weight of 30 ~80 g / m 2 ,and and is an air-through nonwoven fabric with a thickness of 3 to 8 mm, , has water-retaining properties and the exterior body has a front curved elastic member that bulges and is fixed from the side seal portion to the crotch side between the outer sheet layer and the inner sheet layer in the front body, and has a rear curved elastic member that bulges and is fixed from the side seal portion to the crotch side between the outer sheet layer and the inner sheet layer in the rear body, And the front curved elastic member is disposed across an end portion extending to the crotch side of the intermediate sheet, The portion of the aforementioned forward-curving elastic member that crosses the intermediate sheet is arranged to curve so as to bulge outwards towards the crotch area. The rear end of the intermediate sheet is positioned forward of the portion of the rear-curved elastic member that is located closest to the crotch. the rear curved elastic member is not disposed across the intermediate sheet, and is characterized by a disposable diaper.

[0009] An air-through nonwoven fabric is used as the intermediate sheet. Since the air-through nonwoven fabric is difficult for liquid to flow through (easy to retain water), it can quickly receive urine that has passed through the top sheet, suppress backflow, and transfer the urine to the absorber. Also, the basis weight of the intermediate sheet is 30 g / m 2 or more, preferably 30 to 80 g / m 2 and the thickness is 2.5 to 8 mm, more preferably 3 to 7 mm. Since it is bulky and difficult for liquid to flow through, the function of the intermediate sheet is显著 manifested.

[0010] ​If the intermediate sheet is bulky (thick), its rigidity will cause it to try to maintain a flat state. As shown in the schematic diagram in Figure 11, when worn, the absorbent material 56 tends to fold at both edges of the intermediate sheet 40, creating a space between it and the top sheet 30. This space temporarily holds urine, preventing overflow and thus preventing urine leakage. To achieve this configuration, it is desirable that the side edges of the intermediate sheet be located closer to the center in the width direction than the side edges of the absorber. Furthermore, if the absorbent material has cut sections in the middle of its front-to-back direction, where the cuts extend inward in the width direction from both edges, it improves the fit with the wearer. Additionally, if the intermediate sheet is narrower than the width of the absorbent material and extends across the cut sections, it has the advantage of easily exhibiting the shape shown in Figure 11.

[0011] Furthermore, the intermediate sheet is positioned so that its front end is 5 to 50 mm below the crotch area from the ventral front end of the absorbent. If the front end of the intermediate sheet were to coincide with the ventral front end of the absorbent, in cases such as sleeping face down, the urine absorbed by the intermediate sheet may seep forward due to the pressure of sleeping face down, causing leakage to the front. In this regard, by positioning the front end of the intermediate sheet at a predetermined distance below the crotch from the ventral front end of the absorbent, leakage to the front can be prevented or suppressed.

[0012] The absorbent core should ideally be 3-10 mm thick. The basis weight should be 130-250 g / m². 2 Especially 150-220g / m 2 This is desirable to ensure sufficient absorption.

[0013] The disposable diaper can be a pant-type disposable diaper. For example, it can be a pant-type disposable diaper having an inner body in which an absorbent element having an absorbent material mainly composed of cotton pulp and a superabsorbent polymer is interposed between a liquid-permeable top sheet and a liquid-impermeable sheet, and an outer body provided on the back side thereof, with both sides of the outer body joined together to form a waist opening and leg openings. In this configuration, it is desirable to provide a transverse elastic member along the width direction in at least the lower part of the waist of the front body of the outer garment, and to provide curved elastic members that bulge out from both sides of the outer garment toward the crotch and cross the intermediate sheet. In addition to transverse elastic members, curved elastic members allow the intermediate sheet and absorbent elements to fit the wearer's side. [Effects of the Invention]

[0014] According to the present invention, disposable diapers are particularly suitable for preventing or suppressing leakage in wearers with large urine volumes. Furthermore, even if the user is sleeping face down, leakage can be prevented or suppressed. [Brief explanation of the drawing]

[0015] [Figure 1] This is a plan view showing the inside of the first type of disposable pull-up diaper in its unfolded state. [Figure 2] This is a plan view showing the outer surface of a pull-up type disposable diaper in its unfolded state. [Figure 3] This is a cross-sectional view of section 3-3 in Figure 1. [Figure 4] This is a cross-sectional view of section 4-4 in Figure 1. [Figure 5] (a) Cross-sectional view of line 5-5 in Figure 1, and (b) Cross-sectional view of line 5-5 in Figure 1. [Figure 6] This is a perspective view of a pull-up type disposable diaper. [Figure 7] This is a plan view showing the unfolded state of the outer surface of the second type of disposable pull-up diaper. [Figure 8] (a) A cross-sectional view of 8A-8A in Figure 7, and (b) a cross-sectional view of 8B-8B in Figure 7. [Figure 9] This is a plan view of the unfolded state as seen from the side used. [Figure 10] This is a cross-sectional view of line 10-10 in Figure 9. [Figure 11] This is a cross-sectional view showing an overview of the usage condition of the diaper's main compartment. [Modes for carrying out the invention]

[0016] Embodiments of the present invention will be described in detail below with reference to the accompanying drawings. <First type of disposable pull-up diaper> Figures 1 to 6 show an example of the first type of disposable pant-type diaper, 100. The dotted pattern in the cross-sectional view indicates the adhesive used as a joining means to connect the various components located on the front and back sides. This is formed by applying hot melt adhesive in solid, bead, curtain, summit, or spiral coats, or by pattern coating (transfer of hot melt adhesive using a relief printing method). Alternatively, the fixing portion of the elastic component is formed by applying adhesive to the outer surface of the elastic component using a comb gun or SureWrap, either in conjunction with or in conjunction with the above. Examples of hot melt adhesives include EVA-based, adhesive rubber-based (elastomer-based), olefin-based, and polyester / polyamide-based adhesives, but they are not particularly limited in their use. As a joining means to connect the various components, material welding methods such as heat sealing or ultrasonic sealing can also be used.

[0017] The first type of disposable pant-type diaper 100 comprises a front outer body 12F constituting the front body F and a rear outer body 12B constituting the back body B, and an inner body 200 provided inside the outer bodies 12F and 12B so as to extend from the front outer body 12F through the crotch area to the rear outer body 12B. The sides of the front outer body 12F and the sides of the rear outer body 12B are joined to form a side seal portion 12A, so that the openings formed by the front and rear ends of the outer bodies 12F and 12B become a waist opening WO through which the wearer's torso passes, and the portions enclosed by the lower edges of the outer bodies 12F and 12B and the side edges of the inner body 200 on both sides in the width direction become leg openings LO through which the legs pass, as shown in Figure 6. The inner body 200 is the part that absorbs and retains excrement such as urine, and the outer bodies 12F and 12B are the parts that support the inner body 200 against the wearer's body. Furthermore, the symbol Y represents the total length of the diaper in its unfolded state (the length in the front-to-back direction from the edge of the waist opening WO on the front panel F, as shown in Figure 6, to the edge of the waist opening WO on the back panel B), and the symbol X represents the total width of the diaper in its unfolded state.

[0018] Furthermore, the first pant-type disposable diaper 100 has a waist region T defined as a front-to-back range having a side seal portion 12A (a front-to-back range from the waist opening WO to the upper end of the leg opening LO), and an intermediate region L defined as a front-to-back range of the portion forming the leg opening LO (between the front-to-back range of the front body F having the side seal portion 12A and the front-to-back range of the back body B having the side seal portion 12A). Conceptually, the waist region T can be divided into a "waist portion" W that forms the edge of the waist opening and a "lower waist portion" U that is the portion below the waist portion. Normally, if there is a boundary within the waist region T where the widthwise stretch stress changes (for example, the thickness or elongation rate of the elastic member changes), the waist portion W is the portion on the waist opening WO side of the boundary on the waist opening WO side, and if there is no such boundary, the waist portion W is the portion on the waist opening WO side of the absorbent body 56 or inner body 200. These lengths in the front-to-back direction vary depending on the size of the product and can be determined as appropriate. For example, the waist portion W can be 15-40 mm, and the lower waist portion U can be 65-120 mm. On the other hand, both sides of the intermediate region L are constricted in a U-shape or curved shape to conform to the wearer's legs, and this is where the wearer's legs are inserted. As a result, the unfolded pant-type disposable diaper has an overall shape that is roughly hourglass-shaped.

[0019] (Interior body 200) The inner lining 200 can take any shape, but in the illustrated form it is rectangular. As shown in Figures 3 to 5, the inner lining 200 comprises a top sheet 30 that faces the body, a liquid-impermeable sheet 11, and an absorbent element 50 interposed between them, and is the main body responsible for the absorption function. Reference numeral 40 indicates an intermediate sheet (second sheet) provided between the top sheet 30 and the absorbent element 50 to quickly transfer liquid that has permeated through the top sheet 30 to the absorbent element 50, and reference numeral 60 indicates three-dimensional gathers 60 that stand upright on both sides of the inner lining 200 and are provided on both sides of the inner lining 200 to prevent excrement from leaking out.

[0020] The interior body 200 can be fixed to the exterior bodies 12F and 12B by joining means such as heat sealing or ultrasonic sealing, which involve material welding, or by hot melt adhesive. In the illustrated configuration, the interior body 200 is fixed to the inner surfaces of the exterior bodies 12F and 12B by hot melt adhesive applied to the back surface of the interior body 200, that is, in this case, the back surface of the liquid-impermeable sheet 11 and the mounting portion 65 of the three-dimensional gather 60. The interior and exterior fixing portion 201 that fixes the interior body 200 and the exterior bodies 12F and 12B can be provided over almost the entire area where they overlap, and it is usually preferable to provide it in the portion excluding both ends in the width direction of the interior body.

[0021] (Top 30) The top sheet 30 is permeable to liquids, and examples include perforated or non-perforated nonwoven fabrics and porous plastic sheets. Furthermore, the raw material fibers of the nonwoven fabric are not particularly limited. Examples include synthetic fibers such as polyethylene and polypropylene (olefin-based), polyester, and polyamide; regenerated fibers such as rayon and cupro; natural fibers such as cotton; and mixed fibers and composite fibers using two or more of these. Moreover, the nonwoven fabric may be manufactured by any processing method. Examples of processing methods include known methods such as spunlace, spunbond, thermal bond, meltblown, needle punch, air-through, and point bond. For example, if flexibility and drape are desired, the spunbond and spunlace methods are preferred; if bulkiness and softness are desired, the air-through, point bond, and thermal bond methods are preferred. The most suitable material is polypropylene spunbond nonwoven fabric.

[0022] Furthermore, the top sheet 30 may consist of a single sheet or a laminated sheet obtained by bonding two or more sheets together. Similarly, the top sheet 30 may consist of a single sheet or two or more sheets in the planar direction.

[0023] When a three-dimensional gather 60 is provided, it is preferable that both sides of the top sheet 30 are joined to the liquid-impermeable sheet 11 and the three-dimensional gather 60, passing between the liquid-impermeable sheet 11 and the three-dimensional gather 60, and wrapping around to the back side of the absorbent element 50, in order to prevent liquid penetration.

[0024] It is desirable to fix the top sheet 30 to the adjacent component on the back side using a joining method that involves material welding, such as heat sealing or ultrasonic sealing, or by hot melt adhesive, in order to prevent misalignment with the component on the back side. In the illustrated configuration, the top sheet 30 is fixed to the surface of the intermediate sheet 40 and the surface of the part of the packaging sheet 58 that is located on the front side of the absorbent 56 by hot melt adhesive applied to its back surface.

[0025] (Intermediate sheet 40) To quickly transfer the liquid that has permeated through the top sheet 30 to the absorbent material, an intermediate sheet (also called a "second sheet") 40 is provided, which has a faster liquid permeation rate than the top sheet 30. This intermediate sheet 40 not only enhances the absorption performance of the absorbent material by quickly transferring the liquid to the absorbent material, but also prevents the "backflow" phenomenon of the absorbed liquid from the absorbent material, keeping the top sheet 30 constantly dry.

[0026] Examples of the intermediate sheet 40 include the same material as the top sheet 30, as well as spunlace nonwoven fabric, spunbond nonwoven fabric, SMS nonwoven fabric, pulp nonwoven fabric, a mixed sheet of pulp and rayon, point-bonded nonwoven fabric, or crepe paper. Air-through nonwoven fabrics are particularly preferred due to their bulkiness. It is preferable to use a core-sheath composite fiber for the air-through nonwoven fabric; in this case, the resin used for the core may be polypropylene (PP), but polyester (PET) with high rigidity is preferred. The basis weight is 30-80 g / m². 2 Preferably, 35-60 g / m 2is more preferable. The thickness of the raw material fibers of the non-woven fabric is preferably 2.0 to 10 dtex. In order to make the non-woven fabric bulky, it is also preferable to use eccentric fibers without a core in the center, hollow fibers, or eccentric and hollow fibers as all or part of the mixed fibers of the raw material fibers.

[0027] The intermediate sheet 40 in the illustrated form is arranged in the center and shorter than the width of the absorber 56, but it may be provided over the entire width. The longitudinal length of the intermediate sheet 40 may be the same as the length of the absorber 56, or it is desirable to be in a short length range centered on the liquid receiving region, for example, about 40 to 70% of the length of the absorber.

[0028] The intermediate sheet 40 is preferably fixed to the member adjacent to the back side by joining means such as material welding such as heat sealing and ultrasonic sealing or by a hot melt adhesive for the purpose of preventing displacement with respect to the back side member. In the illustrated form, the intermediate sheet 40 is fixed to the surface of the portion of the packaging sheet 58 located on the front side of the absorber 56 by a hot melt adhesive applied to its back surface.

[0029] Due to the above problems, the basis weight of the intermediate sheet is 30 g / m 2 or more, preferably 30 to 80 g / m 2 and it is desirable that the thickness is 2.5 to 8 mm, more preferably 3 to 7 mm. As already explained, when the intermediate sheet is bulky (thick), it tries to maintain a flat state due to its rigidity. Therefore, as shown in the schematic explanatory view of FIG. 11, when worn, the absorber 56 is likely to bend at both side edge portions of the intermediate sheet 40, and a space is likely to be formed between the intermediate sheet 40 and the top sheet 30. The space temporarily stores urine, preventing the urine from overflowing and preventing urine leakage. In order for such a form to appear, it is desirable that both side edges of the intermediate sheet are closer to the center in the width direction than both side edges of the absorber. Furthermore, if the absorbent material has cut sections in the middle of its front-to-back direction, where the cuts extend inward in the width direction from both edges, it improves the fit with the wearer. Additionally, if the intermediate sheet is narrower than the width of the absorbent material and extends across the cut sections, it has the advantage of easily exhibiting the shape shown in Figure 11.

[0030] Furthermore, the front end of the intermediate sheet 40 is positioned 5 to 50 mm below the crotch from the ventral front end of the absorbent body 56. By positioning the front end of the intermediate sheet at a predetermined distance below the crotch from the ventral front end of the absorbent body, leakage to the front can be prevented or suppressed.

[0031] (Liquid-impermeable sheet 11) The material of the liquid-impermeable sheet 11 is not particularly limited, but examples include plastic films made of olefin resins such as polyethylene and polypropylene, laminated nonwoven fabrics with a plastic film on the surface of a nonwoven fabric, and laminated sheets made by layering and bonding a nonwoven fabric to a plastic film. It is preferable to use a material that is both liquid-impermeable and moisture-permeable for the liquid-impermeable sheet 11, which is preferred from the viewpoint of preventing stuffiness. As a moisture-permeable plastic film, a microporous plastic film obtained by kneading an inorganic filler into an olefin resin such as polyethylene or polypropylene, forming a sheet, and then stretching it in a uniaxial or biaxial direction is widely used. In addition, sheets that are made liquid-impermeable without using a plastic film can also be used as the liquid-impermeable sheet 11 by methods such as using a nonwoven fabric made of microdenier fibers, enhancing leak resistance by reducing the voids in the fibers by applying heat or pressure, or coating with a superabsorbent resin or hydrophobic resin or water-repellent agent.

[0032] The liquid-impermeable sheet 11 is designed to fit behind the absorbent element 50, as shown in the figure. In addition, to enhance leak prevention, it can be extended around both sides of the absorbent element 50 to the sides of the top sheet 30 of the absorbent element 50. The width of this extended portion should be approximately 5 to 20 mm on each side.

[0033] Furthermore, an excretion indicator that changes color due to the absorption of liquid can be provided on the inside of the liquid-impermeable sheet 11, particularly on the side surface of the absorbent material 56.

[0034] (3D Gathered 60) The three-dimensional gathers 60 are strip-shaped members that extend along both sides of the inner body 200 in the entire front-to-back direction, and are provided to block excrement that moves laterally along the top sheet 30 and prevent lateral leakage. In this embodiment, the three-dimensional gathers 60 are provided to stand up from the sides of the inner body 200, with the base portion standing diagonally towards the center in the width direction, and the portion from the middle to the tip portion standing diagonally outward in the width direction.

[0035] More specifically, the three-dimensional gather 60 is made by folding a strip-shaped gather sheet 62, which has a length equal to the front-to-back length of the interior body 200, in the width direction and overlapping it in two. Multiple elongated gather elastic members 63 are fixed between the folded portion and the sheet in its vicinity, extended along the longitudinal direction and spaced apart in the width direction. The base end of the three-dimensional gather 60, located opposite the tip (the end opposite the folded portion in the width direction), is an attachment portion 65 fixed to the back surface of the side edge of the interior body 200, and the portion other than this attachment portion 65 is a protruding portion 66 (the portion on the folded portion side) that protrudes from the attachment portion 65. The protruding portion 66 consists of a base portion that faces the center in the width direction and a tip portion that is folded outward in the width direction from the tip of this base portion. This form is a surface contact type three-dimensional gather, but a line contact type three-dimensional gather (not shown) that is not folded outward in the width direction can also be used. Furthermore, while the front and rear ends of the protruding portion 66 are fixed to the side surface of the top sheet 30 in a collapsed state, forming front and rear fixed portions 67, the front and rear intermediate portion located between these is an unfixed free portion 68, and a gathered elastic member 63 oriented in the front and rear direction is fixed to this free portion 68 in an extended state.

[0036] In the free portion 68 of the three-dimensional gather 60, at least one of hot-melt adhesives applied using various methods and fixing means such as heat sealing or ultrasonic sealing can be used to bond the inner and outer layers of the gather sheet 62 and to fix the gather elastic member 63 sandwiched between them. Since bonding the entire inner and outer layers of the gather sheet 62 would impair flexibility, it is preferable that the parts of the gather elastic member 63 other than the bonded parts are not bonded or are weakly bonded. In the illustrated embodiment, hot-melt adhesive is applied only to the outer surface of the gather elastic member 63 using an application means such as a comb gun or Surewrap nozzle, and the member is sandwiched between the inner and outer layers of the gather sheet 62. This structure allows the elongated elastic member to be fixed to the inner and outer layers of the gather sheet 62 and to be fixed between the inner and outer layers of the gather sheet 62 using only the hot-melt adhesive applied to the outer surface of the gather elastic member 63.

[0037] Furthermore, to fix the waterproof film 64 incorporated into the three-dimensional gather 60 to the gather sheet 62, and to fix the front and rear fixing parts 67 to the side surface of the interior body 200, at least one of hot melt adhesives applied using various methods, and material welding methods such as heat sealing or ultrasonic sealing can be used. In the illustrated embodiment, slot application of hot melt adhesive is used to fix the waterproof film 64. In addition, although a combination of hot melt adhesive and material welding is used to fix the front and rear fixing parts 67 in the illustrated embodiment, these fixings can also be performed using only one of these methods.

[0038] As the gathered sheet 62, flexible, uniform, and opaque nonwoven fabrics such as spunbond nonwoven fabric (SS, SSS, etc.), SMS nonwoven fabric (SMS, SSMMS, etc.), and meltblown nonwoven fabric can be suitably used, and may be treated with a water-repellent coating such as silicone as needed. The fiber weight should be 10-30 g / m². 2It is preferable to have a thickness of approximately 600-1240 dtex. As the elongated elastic member 63, thread elastic or the like can be used. When using spandex thread elastic, the thickness is preferably 470-1240 dtex, and more preferably 620-940 dtex. The elongation rate when fixed is preferably 150-350%, and more preferably 200-300%. Also, as shown in the figure, a waterproof film 64 can be interposed between the two folded gathered sheets.

[0039] The number of elongated elastic members 63 provided in the free portion of the three-dimensional gather 60 is preferably 2 to 6, and more preferably 3 to 5. The spacing 60d between them is appropriately 3 to 10 mm. With this configuration, the area where the elongated elastic members 63 are placed will be more likely to make contact with the skin over a larger surface area. The elongated elastic members 63 may be placed not only at the tip but also at the base.

[0040] The attachment portion 65 of the three-dimensional gather 60 can be fixed to any appropriate member of the interior body 200, such as the top sheet 30, the liquid-impermeable sheet 11, or the absorbent element 50.

[0041] In the three-dimensional gather 60 thus constructed, the contraction force of the elongated elastic member 63 acts to bring both ends in the front-to-back direction closer together. However, while the front-to-back ends of the protruding portion 66 are fixed so as not to stand up, the area between them is left as an unfixed free portion. Therefore, only the free portion stands up so as to come into contact with the body, as shown in Figure 3. In particular, if the attachment portion 65 is located on the back side of the inner body 200, the three-dimensional gather 60 stands up so as to open outward in the width direction in the crotch area and its vicinity, so that the three-dimensional gather 60 comes into contact with the legs over a surface area, improving the fit.

[0042] The dimensions of the three-dimensional gathers 60 can be determined as appropriate, but in the case of infant diapers, for example, as shown in Figure 3, the standing height (width of the protruding portion 66 in the unfolded state) W6 of the three-dimensional gathers 60 is preferably 15 to 60 mm, and particularly preferably 20 to 40 mm. Also, when the three-dimensional gathers 60 are folded flat so as to be parallel to the surface of the top sheet 30, the distance W3 between the innermost folds is preferably 60 to 190 mm, and particularly preferably 70 to 140 mm.

[0043] In addition, unlike the illustrated configuration, the interior body 200 can also be provided with double (two rows) three-dimensional gathers on both the left and right sides.

[0044] (Absorption element 50) The absorbent element 50 comprises an absorbent body 56 and a packaging sheet 58 that encloses the entire absorbent body 56. The packaging sheet 58 may be omitted.

[0045] (Absorbent material 56) The absorbent body 56 can be formed from a fiber aggregate. This fiber aggregate can be made by stacking short fibers such as cotton pulp or synthetic fibers, or by using filament aggregates obtained by opening tows (fiber bundles) of synthetic fibers such as cellulose acetate as needed. For fiber basis weight, when using cotton pulp or stacked short fibers, for example, 100-300 g / m² is used. 2 It can be set to a certain extent, and in the case of filament aggregates, for example, 30-120 g / m². 2 The fineness can be set to a certain extent. In the case of synthetic fibers, the fineness is, for example, 1 to 16 dtex, preferably 1 to 10 dtex, and more preferably 1 to 5 dtex. In the case of a filament aggregate, the filaments may be non-crimped fibers, but crimped fibers are preferred. The degree of crimp of the crimped fibers can be, for example, 5 to 75 per 2.54 cm, preferably 10 to 50, and more preferably 15 to 50. Uniformly crimped fibers can also be used. It is preferable to disperse and retain highly absorbent polymer particles in the absorbent body 56.

[0046] The absorbent material 56 may be rectangular in shape, but as shown in Figures 1 and 2, it is preferable to have an hourglass shape with a front end, a rear end, and a constricted section located between them that is narrower than the front and rear ends, because this improves the fit of the absorbent material 56 itself and the three-dimensional gathers 60 around the legs.

[0047] Furthermore, the dimensions of the absorbent body 56 can be appropriately determined as long as it extends in all directions (front, back, left, and right) around the urinary opening, but it is preferable that it extends to the peripheral edge of the inner casing or its vicinity in the front-to-back and width directions. Reference numeral 56X indicates the width of the absorbent body 56.

[0048] The absorbent core should ideally be 3-10 mm thick. The basis weight should be 130-250 g / m². 2 Especially 150-220g / m 2 This is desirable to ensure sufficient absorption.

[0049] (Highly absorbent polymer particles) The absorbent material 56 may contain superabsorbent polymer particles in part or in whole. Superabsorbent polymer particles include not only "particles" but also "powder." As for the superabsorbent polymer particles 54, those used in this type of disposable diaper can be used as is, and it is desirable that the percentage of particles remaining on the sieve after sieving (shaking for 5 minutes) using a 500 μm standard sieve (JIS Z8801-1:2006) is 30% by weight or less, and it is also desirable that the percentage of particles remaining on the sieve after sieving (shaking for 5 minutes) using a 180 μm standard sieve (JIS Z8801-1:2006) is 60% by weight or more.

[0050] While there are no particular limitations on the material used for the superabsorbent polymer particles, those with a water absorption capacity of 40 g / g or more are preferred. Examples of superabsorbent polymer particles include starch-based, cellulose-based, and synthetic polymer-based materials. Starch-acrylic acid (salt) graft copolymers, saponified starch-acrylonitrile copolymers, crosslinked sodium carboxymethylcellulose, and acrylic acid (salt) polymers can be used. While the commonly used granular form is preferred for the superabsorbent polymer particles, other forms can also be used.

[0051] As superabsorbent polymer particles, those with a water absorption rate of 70 seconds or less, and particularly 40 seconds or less, are preferably used. If the water absorption rate is too slow, the liquid supplied into the absorbent material 56 is likely to flow back out of the absorbent material 56, a phenomenon known as backflow. As the superabsorbent polymer particles, those with high liquid permeability are preferably used.

[0052] The basis weight of the superabsorbent polymer particles can be appropriately determined according to the amount of absorption required for the application of the absorbent material 56. Therefore, it is not possible to say definitively, but it is generally between 50 and 350 g / m². 2 This can be achieved. The basis weight of the polymer is 50 g / m². 2 Below 350g / m², it becomes difficult to ensure sufficient absorption. 2 Beyond a certain point, the effect saturates.

[0053] If necessary, the dispersion density or amount of superabsorbent polymer particles can be adjusted in the planar direction of the absorbent body 56. For example, the amount of liquid discharged can be increased at the discharge site compared to other sites. When considering gender differences, the dispersion density (amount) can be increased at the front for men and at the central part for women. It is also possible to provide areas in the planar direction of the absorbent body 56 where the polymer is not present locally (e.g., in a spot-like manner).

[0054] (Packaging sheet 58) When using packaging sheets 58, the material can be tissue paper, especially crepe paper, nonwoven fabric, poly-laminated nonwoven fabric, or sheets with small holes. However, it is desirable that the sheet does not allow superabsorbent polymer particles to escape. When using nonwoven fabric instead of crepe paper, hydrophilic SMS nonwoven fabric (SMS, SSMMS, etc.) is particularly suitable, and the material can be polypropylene, polyethylene / polypropylene composite, etc. The basis weight should be 5-40 g / m². 2 Especially 10-30g / m 2 That would be preferable.

[0055] The packaging form of the packaging sheet 58 can be determined as appropriate, but from the viewpoint of ease of manufacturing and preventing leakage of highly absorbent polymer particles from the front and rear edges, it is preferable to wrap the sheet around the absorbent body 56 in a cylindrical shape so as to surround the front and back surfaces and both sides, with the front and rear edges extending beyond the front and rear of the absorbent body 56, and to join the overlapping portions and the overlapping portions of the front and rear by joining means such as hot melt adhesive or material welding.

[0056] (Exterior 12F, 12B) The outer casings 12F and 12B consist of a front outer casing 12F, which constitutes the front body F, and a rear outer casing 12B, which constitutes the back body B. The front outer casing 12F and the rear outer casing 12B are not continuous at the crotch and are spaced apart in the front-to-back direction. This separation distance 12d can be approximately 150 to 250 mm. It is desirable to attach a crotch cover sheet 12M made of nonwoven fabric or the like to cover a part of the exposed area on the back surface of the inner casing 200 in this separated area (for example, the entire area in the front-to-back direction of the exposed area between the front outer casing 12F and the rear outer casing 12B, but not extending to the front and rear ends of the inner casing 200, and the widthwise side edges not reaching the side edges of the inner casing 200) or the entire area, but this can be omitted. Also, as shown in Figures 7 and 8, the outer casing 12 can be a single, continuous piece that passes through the crotch from the front body F to the back body B. In other words, the outer garments 12F and 12B, which individually constitute the front body F and back body B, correspond to the former form, while the outer garment 12, which integrally constitutes the front body F and back body B, corresponds to the latter form.

[0057] The outer casings 12F and 12B have a waist portion that corresponds to the waist region T in the front-to-back direction. In this embodiment, the front outer casing 12F does not have a portion corresponding to the intermediate region L, but the rear outer casing 12B has a buttock cover portion 14 that extends from the waist region T towards the intermediate region L. Although not shown, the front outer casing 12F may also be provided with an inguinal cover portion that extends from the waist region T towards the intermediate region L, or it may be provided with an inguinal cover portion but not a buttock cover portion, or it may not be necessary to provide portions corresponding to the intermediate region L in both the front outer casing 12F and the rear outer casing 12B. In the illustrated embodiment, the lower edge of the buttock cover portion 14 is formed in a straight line along the width direction, similar to the lower edge of the front outer casing 12F, but it can also be a curve that is positioned towards the waist opening as it moves outward in the width direction.

[0058] As shown in Figures 3 to 5, the outer casings 12F and 12B are formed by joining an outer sheet layer 12S and an inner sheet layer 12H using a joining method such as hot melt adhesive or welding. The sheet material forming the outer sheet layer 12S and the sheet material forming the inner sheet layer 12H can be a single common sheet material as shown in Figure 5, or they can be separate sheet materials as shown in Figure 8. In the former case, the inner sheet layer 12H and the outer sheet layer 12S are formed by the inner and outer parts of a single sheet material that is folded over at the edge of the waist opening WO (which may also be the edge on the crotch side). The former configuration has the advantage of being less prone to shifting when bonding the inner sheet layer 12H and the outer sheet layer 12S, while the latter configuration has the advantage of requiring fewer sheet materials.

[0059] The sheet material used for the outer sheet layer 12S and the inner sheet layer 12H is not particularly limited, but nonwoven fabric is preferred. For example, nonwoven fabrics made of synthetic fibers such as polyethylene, polypropylene, olefins, polyesters, and polyamides, or mixed fibers and composite fibers using two or more of these, can be used. Furthermore, the nonwoven fabric may be manufactured by any processing method. Examples of processing methods include known methods such as spunlace, spunbond, thermal bond, meltblown, needle punch, air-through, and point bond. When using nonwoven fabric, its basis weight should be 10-30 g / m². 2 It is preferable to keep it to a certain degree.

[0060] Furthermore, the total weight of the outer casing (12F, 12B) is 20-60g / m². 2 It is preferable that it be of a certain degree.

[0061] (Stretchable area / non-stretchable area) Furthermore, in the outer casings 12F and 12B, elongated elastic members 15 to 19, such as elastic thread, are provided between the outer sheet layer 12S and the inner sheet layer 12H to improve the fit around the wearer's waist, forming an expandable region that elastically expands and contracts in the width direction as the elastic members expand and contract. In this expandable region, in the natural length state, the outer sheet layer 12S and the inner sheet layer 12H contract as the elastic members contract, forming wrinkles or folds. When stretched in the longitudinal direction of the elastic members, the outer sheet layer 12S and the inner sheet layer 12H can be stretched to a predetermined elongation rate without wrinkles. The elongated elastic members 15 to 19 may be made of synthetic rubber or natural rubber. For bonding the outer sheet layer 12S and the inner sheet layer 12H of the exterior bodies 12F and 12B, and for fixing the elongated elastic members 15-19 sandwiched between them, at least one of hot-melt adhesives applied using various methods and fixing means such as heat sealing or ultrasonic sealing can be used. Since firmly fixing the entire surface of the exterior bodies 12F and 12B would impair flexibility, it is preferable that the parts of the elongated elastic members 15-19 other than the bonded parts are not bonded or are weakly bonded. In the illustrated embodiment, hot-melt adhesive is applied only to the outer circumferential surfaces of the elongated elastic members 15-19 using an application means such as a comb gun or Surewrap nozzle, and they are sandwiched between the two sheet layers 12S and 12H. This structure ensures that the elongated elastic members 15-19 are fixed to the two sheet layers 12S and 12H, and that the two sheet layers 12S and 12H are fixed together using only the hot-melt adhesive applied to the outer circumferential surfaces of the elongated elastic members 15-19. The elastic members 15-19 can be fixed to the outer sheet layer 12S and the inner sheet layer 12H only at both ends in the expansion / contraction direction within the expansion / contraction region.

[0062] More specifically, in the waist portion W of the outer bodies 12F and 12B, multiple waist elastic members 17 are attached at vertical intervals between the outer sheet layer 12S and the inner sheet layer 12H, so as to be continuous throughout the entire width direction. Furthermore, one or more of the waist elastic members 17 located in the region adjacent to the lower waist portion U may overlap with the inner body 200, or they may be provided on both sides in the width direction, excluding the central portion in the width direction that overlaps with the inner body 200. The waist elastic members 17 have a thickness of 155 to 1880 dtex, particularly around 470 to 1240 dtex (in the case of synthetic rubber; in the case of natural rubber, the cross-sectional area is 0.05 to 1.5 mm²). 2 Especially 0.1~1.0mm 2 It is preferable to provide 3 to 22 strands of elastic thread (of a certain thickness) at intervals of 4 to 12 mm, and the resulting elongation rate in the width direction of the waist portion W is preferably 150 to 400%, and particularly preferably 220 to 320%. Furthermore, it is not necessary to use waist portion elastic members 17 of the same thickness or have the same elongation rate throughout the entire front-to-back direction of the waist portion W; for example, the thickness and elongation rate of the elastic members 17 may differ between the upper and lower parts of the waist portion W.

[0063] Furthermore, multiple waist-lower elastic members 15 and 19, made of elongated elastic material, are attached between the outer sheet layer 12S and the inner sheet layer 12H in the waist-lower portion U of the outer casings 12F and 12B, spaced apart in the vertical direction.

[0064] The elastic members 15 and 19 in the lower waist section should have a thickness of 155 to 1880 dtex, especially around 470 to 1240 dtex (in the case of synthetic rubber; in the case of natural rubber, the cross-sectional area should be 0.05 to 1.5 mm²). 2 Especially 0.1~1.0mm 2 It is preferable to provide about 5 to 30 strands of elastic thread (of a certain degree) at intervals of 1 to 15 mm, and especially 3 to 8 mm, and the resulting elongation rate in the width direction of the lower waist U is preferably 200 to 350%, and especially 240 to 300%.

[0065] Furthermore, multiple elongated elastic members 16 are attached between the outer sheet layer 12S and the inner sheet layer 12H of the rear outer casing 12B, spaced apart in the vertical direction.

[0066] The elastic member 16 of the cover section has a thickness of 155 to 1880 dtex, especially around 470 to 1240 dtex (in the case of synthetic rubber; in the case of natural rubber, the cross-sectional area is 0.05 to 1.5 mm²). 2 Especially 0.1~1.0mm 2 It is preferable to provide 2 to 10 strands of elastic thread (of a certain degree) at intervals of 5 to 40 mm, and especially 5 to 20 mm, and the resulting elongation rate in the width direction of the cover portion is preferably 150 to 300%, and especially 180 to 260%.

[0067] If an inguinal cover portion is provided on the front outer casing 12F, an elastic member for the cover portion can be provided in a similar manner.

[0068] When elastic members 15, 16, and 19 are provided in the front-to-back range having an absorbent 56, such as the lower waist portion U and the buttock cover portion 14 in the illustrated configuration, in order to prevent contraction of the absorbent 56 in the width direction in part or all of the portion, the middle of the width direction including part or all of the portion overlapping with the absorbent 56 in the width direction (preferably including the entire inner and outer fixing portion 201) is designated as a non-stretchable region A1, and both sides of that in the width direction are designated as stretchable regions A2. It is preferable that the waist portion W is a stretchable region A2 throughout its entire width direction, but similar to the lower waist portion U, a non-stretchable region may be provided in the middle of the width direction.

[0069] (Formation of non-stretchable regions) The expandable region A2 and the non-expandable region A1 can be constructed by supplying elastic members 15-17, 19 between the inner sheet layer 12H and the outer sheet layer 12S, on which a display sheet 25 is fixed to the inner surface with hot-melt adhesives H1, H2. The elastic members 15, 16, 19 are fixed at least at both ends in the expansion direction of the expandable region A2 via hot-melt adhesive, but not in the region that becomes the non-expandable region A1. In the region that becomes the non-expandable region A1, the elastic members 15, 16, 19 are cut by pressurizing and heating at one point in the middle of the width direction, or by cutting almost the entire elastic members 15, 16, 19 into small pieces by pressurizing and heating, thereby retaining expandability in the expandable region A2 while eliminating expandability in the non-expandable region A1.

[0070] <Second type of disposable pant-style diaper> The first type of disposable pant-style diaper, shown in Figures 1 to 6, has a structure in which an inner body 200 is provided spanning between the front and rear outer bodies 12F and 12B. Alternatively, instead of this first type of disposable pant-type diaper, a second type of disposable pant-type diaper may be used, as shown in Figures 7 to 10, which has an inner lining 200 provided inside the outer sheet layer 12S and inner sheet layer 12H that are not divided into front and back sections. If the constituent materials of the second type of disposable diaper are substantially the same as those of the first type of disposable diaper, the same reference numeral is used and the explanation is omitted.

[0071] In the second type of disposable pant-style diaper, the front body F has a front-curving elastic member 70F positioned between the outer sheet layer 12S and the inner sheet layer 12H, which bulges outwards from the side seal portions 12A and 12A towards the crotch and is fixed with hot-melt adhesive. In addition, the back body B has a rear-curving elastic member 70B positioned between the outer sheet layer 12S and the inner sheet layer 12H, which bulges outwards from the side seal portions 12A and 12A towards the crotch and is fixed with hot-melt adhesive.

[0072] Comparing the position of the front-curving elastic member 70F in Figure 7 with the position of the edge of the intermediate sheet 40 extending towards the crotch, it is found that the optimal configuration for enhancing the urine absorption of the intermediate sheet 40 is for the front-curving elastic member 70F to be positioned across the edge of the intermediate sheet 40 that extends towards the crotch, thereby allowing the intermediate sheet 40 to actively come into contact with the wearer's skin.

[0073] Furthermore, the liquid-impermeable sheet 11 can be made to have a horizontal stripe design, for example, spaced apart in the front-to-back direction of the diaper, and this horizontal stripe design can be made visible from the outside.

[0074] <Other> • The above example is an application to pull-up type disposable diapers, but it can be applied to tape-type disposable diapers and pad-type disposable diapers in general.

[0075] <Explanation of terms used in the specification> The following terms in this specification shall have the meanings set forth below unless otherwise specified in this specification.

[0076] As shown in the diagram, the "anterior-posterior (longitudinal) direction" refers to the direction connecting the ventral (front) side and the dorsal (back) side, while the "width direction" refers to the direction perpendicular to the anterior-posterior direction (left-right direction).

[0077] • "Elongation rate" refers to the value relative to the natural length, which is set at 100%. For example, an elongation rate of 200% is equivalent to an elongation ratio of 2.

[0078] "Weight" is measured as follows: After pre-drying the sample or test piece, leave it in a test room or apparatus under standard conditions (temperature 23±1°C, relative humidity 50±2%) to reach a constant weight. Pre-drying means bringing the sample or test piece to a constant weight in an environment of 100°C. Note that pre-drying is not necessary for fibers with an official moisture content of 0.0%. Using a sample-taking template (100mm x 100mm), cut out a sample measuring 100mm x 100mm from the test piece that has reached a constant weight. Measure the weight of the sample, multiply it by 100 to calculate the weight per square meter, and this is the weight.

[0079] • "Thickness" was measured using an automatic thickness measuring instrument (KES-G5 handy compression measurement program) with a load of 0.098 N / cm². 2 , and pressure area: 2cm 2 Automatic measurement is performed under these conditions.

[0080] • Water absorption is measured according to JIS K7223-1996 "Test method for water absorption of superabsorbent polymers".

[0081] The water absorption rate shall be the "time to the endpoint" when 2 g of superabsorbent polymer and 50 g of physiological saline solution are used in the JIS K7224-1996 "Test method for water absorption rate of superabsorbent polymers".

[0082] "Unfolded state" refers to a state in which something is unfolded flat without contraction or sagging.

[0083] Unless otherwise specified, the dimensions of each part refer to the dimensions in the unfolded state, not the natural length state.

[0084] Unless otherwise specified, the tests and measurements shall be conducted in a test room or apparatus under standard conditions (temperature 23±1°C, relative humidity 50±2%). [Industrial applicability]

[0085] The present invention can be used in the above-mentioned example of disposable pant-type diapers. [Explanation of Symbols]

[0086] 11...Liquid-impermeable sheet, 12...Outer casing, 12A...Side seal section, 12F...Front outer casing, 12B...Rear outer casing, 12H...Inner sheet layer, 12S...Outer sheet layer, 30...Top sheet, 40...Intermediate sheet, 50...Absorbing element, 56...Absorbing material, 58...Packaging sheet, 60...Three-dimensional gather, 62...Gathered sheet, 70F...Front curved elastic member, 70B...Rear curved elastic member, 200...Inner casing.

Claims

1. Between the permeable top sheet and the liquid-impermeable sheet is a layer primarily composed of cotton-like pulp, with a thickness of 3 to 10 mm and a basis weight of 130 to 250 g / m². ２ This is a pant-type disposable diaper having an inner body containing an absorbent element having an absorbent material and a superabsorbent polymer, and an outer body provided on the back side thereof, wherein the sides of the outer body on the front and the sides of the outer body on the back are joined to form a side seal, and waist openings and leg openings are formed. The absorbent material extends from the front of the body through the crotch to the back of the body, and has a front end, a back end, and a constricted portion located between them, which is narrower in width than the front end and the back end. An intermediate sheet, narrower than the absorbent, is interposed between the permeable top sheet and the absorbent element. The front end of the intermediate sheet is located 5 to 50 mm below the crotch from the ventral front end of the absorbent material. The longitudinal length of the intermediate sheet is in the range of 40 to 70% of the length of the absorbent. The side edges of the aforementioned intermediate sheet are located closer to the center in the width direction than the side edges of the absorbent. The aforementioned intermediate sheet has a fiber thickness of 2.0 to 10 dtex and a basis weight of 30 to 80 g / m². ２ Furthermore, it is a water-retentive, air-through nonwoven fabric with a thickness of 3 to 8 mm. The outer body has a front-curving elastic member positioned and fixed between the outer sheet layer and the inner sheet layer of the front body, bulging outwards from the side seal portion towards the crotch, and a rear-curving elastic member positioned and fixed between the outer sheet layer and the inner sheet layer of the back body, bulging outwards from the side seal portion towards the crotch. The aforementioned forward-curving elastic member intersects with the side edge of the absorber in front of the constricted portion and is positioned across the end that extends towards the crotch side of the intermediate sheet in the region having the constricted portion. The portion of the aforementioned forward-curving elastic member that crosses the intermediate sheet is arranged to curve so as to bulge outwards towards the crotch area. The rear-curving elastic member is positioned so as to intersect the side edge of the absorber behind the constricted portion and pass through the region having the constricted portion, the rear end of the intermediate sheet is positioned in front of the portion of the rear-curving elastic member located closest to the crotch, and the rear-curving elastic member is not positioned across the intermediate sheet. Disposable diapers characterized by the following:

2. The absorbent material extends from the front of the garment through the crotch to the back of the garment, and each of the front-to-back intermediate portions of the absorbent material has cut sections that are notched inward in the width direction from both side edges. The disposable diaper according to claim 1, wherein the intermediate sheet is narrower than the width of the absorbent material and extends to the cut portion.

3. In the aforementioned outer garment, a transversely elastic member is provided along the width direction in at least the lower part of the waist of the front body. A disposable diaper according to claim 1.

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