Absorbent article

Abstract

An absorbent article (1) in which, in a state in which a fixing portion (5) is engaged with predetermined positions of waist portions (20, 30) that are separated from each other to form a waist opening portion, at a predetermined contraction rate of 55% or more, at a central position in the up-down direction of the fixing portion (5), the length of the waist portions (20, 30) from the center in the left-right direction to one side end and the length of the waist portions (20, 30) from the center in the left-right direction to the other side end are identical, the value obtained by dividing the extension force acting on the waist portions (20, 30) when the waist portions (20, 30) are elongated in the left-right direction to a contraction rate that is 10% higher than the certain contraction rate by the extension force acting on the waist portions (20, 30) when the waist portions (20, 30) are elongated in the left-right direction to the certain contraction rate is 1.8 or more.

Description

Technical Field

[0001] This invention relates to an absorbent article. Background Technology

[0002] Patent Document 1 discloses a disposable diaper, which is a shorts-type diaper with a waist opening and a pair of leg openings. The diaper does not increase the wearing pressure at the waist opening compared to previous methods, but increases the wearing pressure on the wearer from the iliac crest to the anterior superior iliac spine. According to this shorts-type disposable diaper, slippage during diaper wearing can be effectively prevented.

[0003] Existing technical documents

[0004] Patent documents

[0005] Patent Document 1: Japanese Patent Application Publication No. 2006-61680 Summary of the Invention

[0006] The problem the invention aims to solve

[0007] Typically, when wearing shorts-type diapers, the user first extends their waist considerably, and the user's or the wearer's legs are inserted. Therefore, to facilitate this extension, the stress (so-called constant-tension stress) acting on the waist when it stretches is designed to be relatively small. Consequently, even with studies on the configuration of stretchable materials as in Patent Document 1, shorts-type diapers still present the problem that when the wearer's posture changes, or their waistline shifts due to eating or other factors, the waist tends to stretch, causing the diaper to slip and leak.

[0008] The present invention was made in view of the aforementioned problems, and its object is to provide an absorbent article that easily maintains a fit that adapts to changes in the wearer's waistline.

[0009] Solution for solving the problem

[0010] The main invention for achieving the above-mentioned objective is an absorbent article having mutually orthogonal vertical, horizontal, and front-back directions, and having a waist section and a crotch section, wherein the waist section comprises one side waist section and another side waist section, characterized in that,

[0011] The absorbent article has a fixing part.

[0012] The front end of the fastening part has a locking part that can be detachably engaged with the non-skin side of the waist.

[0013] The waist section is equipped with a telescopic component that extends and retracts in the left-right direction.

[0014] With the fixing part engaging with at least one predetermined position of the separated waist part to form a waist opening, the fixing part is engaged with the engaging part.

[0015] When the shrinkage rate is defined as the ratio obtained by dividing the length of the waist portion in the left-right direction by the length of the waist portion in the left-right direction when it is at its maximum elongation.

[0016] At a predetermined shrinkage rate of 55% or more, at the center position of the fixed portion in the vertical direction, the length of the waist portion from the center in the horizontal direction to one side of the horizontal direction is the same as the length of the waist portion from the center in the horizontal direction to the other side of the horizontal direction.

[0017] The elongation force acting on the waist section when it stretches along the left-right direction to a contraction rate that is 10% higher than 55% is divided by the elongation force acting on the waist section when it stretches along the left-right direction to the contraction rate, resulting in a value of 1.8 or higher.

[0018] Other features of the invention will become clear from the description in this specification and the accompanying drawings.

[0019] The effects of the invention

[0020] According to the present invention, an absorbent article is provided that easily maintains a fit that adapts to changes in the wearer's waistline. Attached Figure Description

[0021] Figure 1 This is a 3D image of a disposable diaper 1 in its worn state.

[0022] Figure 2 This is a top view of the diaper 1 in its natural state, observed from the ventral side (20 sides).

[0023] Figure 3 This is a top view of the diaper 1 in its unfolded and elongated state, viewed from the non-skin side.

[0024] Figure 4 yes Figure 3 A magnified view of part X in the image.

[0025] Figure 5 This diagram illustrates the separation of the ventral waist section 20 and the formation of the waist opening.

[0026] Figure 6 This diagram illustrates the action of cutting off the ventral waist section 20.

[0027] Figure 7 This is an explanatory diagram of the marking part 60 for engaging the fixing part 50.

[0028] Figure 8 of Figure 8 A and Figure 8 B is an explanatory diagram regarding the contraction rate of the waist at 20 and 30 degrees.

[0029] Figure 9 of Figure 9 A~ Figure 9 C is an explanatory diagram illustrating the method for measuring the elongation and contraction forces at waist 20 and 30.

[0030] Figure 10 of Figure 10 A and Figure 10 B is a graph showing the measurement results of the elongation and contraction forces of diaper 1 of size S.

[0031] Figure 11 of Figure 11 A and Figure 11 B is a graph showing the measurement results of the elongation and contraction forces of diaper 1 of size M.

[0032] Figure 12 This diagram illustrates the engaging portion 25 and the non-stretchable region N.

[0033] Figure 13 of Figure 13 A and Figure 13 B is a diagram showing a modified example of the marking part 60.

[0034] Figure 14 of Figure 14 A and Figure 14 B is a diagram showing a modified example of the marking part 60.

[0035] Figure 15 This is an enlarged view of the fixed part F1 and the auxiliary fixed part F2. Detailed Implementation

[0036] Based on the description in this specification and the accompanying drawings, at least the following matters become clear.

[0037] (Method 1)

[0038] An absorbent article has mutually orthogonal vertical, horizontal, and front-back directions, and includes a waist section and a crotch section. The waist section comprises one side waist section and another side waist section. The absorbent article has a fastening portion, the front end of which has a locking portion that can detachably engage with the non-skin side of the waist section. The waist section includes a telescopic member that extends and retracts along the horizontal direction. When the fastening portion engages with at least one predetermined position of the separated waist section using the locking portion to form a waist opening, the length of the waist section in the horizontal direction divided by the maximum elongation of the waist section... When the ratio obtained by the length in the left-right direction is the shrinkage rate, at a predetermined shrinkage rate of 55% or more, at the center position of the fixed part in the vertical direction, the length of the waist part from the center in the left-right direction to one side of the left-right direction and the length of the waist part from the center in the left-right direction to the other side of the left-right direction are the same. The value obtained by dividing the elongation force acting on the waist part when the waist part is stretched in the left-right direction to a shrinkage rate that is 10% higher than a certain shrinkage rate of 55% or more by the elongation force acting on the waist part when the waist part is stretched in the left-right direction to the certain shrinkage rate is 1.8 or more.

[0039] According to method 1, compared to the case where the elongation force ratio is less than 1.8, the ease of stretching at the waist can be moderately suppressed. Therefore, when the wearer's waist circumference increases, the force applied to the wearer's body from the waist is also greater, making it easier to maintain a fit that corresponds to changes in the wearer's waist. Thus, it can suppress slippage at the waist and leakage of excrement. In addition, when wearing absorbent materials, the fastening part is locked even when the waist is separated, so even though the ease of stretching at the waist is suppressed, the user is less likely to experience difficulty in wearing it. Furthermore, when the waist is worn at a predetermined contraction rate, the balance of the length of the waist on both sides is better, making it less likely to cause discomfort to the wearer.

[0040] (Method 2) Among the absorbent articles described in Method 1,

[0041] The value obtained by dividing the contraction force acting on the waist section when it contracts to the specified contraction rate in the left-right direction by the elongation force acting on the waist section when it stretches to the specified contraction rate in the left-right direction is 0.8 or less.

[0042] According to method 2, compared to cases where the value obtained by dividing the contraction force by the elongation force is greater than 0.8, the contraction force relative to the elongation force is smaller. Therefore, when the waist area is fitted to match the wearer's waist circumference, the force exerted on the wearer's body from the waist area is smaller, reducing the feeling of tightness. Thus, the wearing comfort of absorbent materials can be improved.

[0043] (Method 3) In the absorbent articles described in Method 1 or Method 2,

[0044] The waist portion has: a locking portion that can engage with the fixing portion; and a non-stretchable region in which the stretchable member is not present from the upper end to the lower end of the waist portion, and the locking portion has a portion that overlaps with the non-stretchable region in the left-right direction.

[0045] According to method 3, when a user wears an absorbent material, when one hand grasps the fixing part and the other hand grasps the locking part or its vicinity, the locking part is not easy to extend in the left and right directions and is not easy to become unstable. Therefore, the fixing part can be stably and closely locked to the locking part.

[0046] (Method 4) Among the absorbent articles described in Method 3,

[0047] In the left-right direction, the entire area of ​​the engaged portion overlaps with the non-stretchable area.

[0048] According to method 4, when a user wears an absorbent material, when one hand grasps the fixing part and the other hand grasps the locking part or its vicinity, the locking part is not easy to extend in the left and right directions and is not easy to become unstable. Therefore, the fixing part can be stably and closely locked to the locking part.

[0049] (Method 5) Among the absorbent articles described in any of Methods 1 to 4,

[0050] The absorbent article has an absorbent body, and the waist portion has a non-stretchable region on the front side in the front-rear direction, from the upper end to the lower end of the waist portion, where the stretchable member is not present. The non-stretchable region is located at the center of the absorbent body in the left-right direction across the front side. When the fixing portion is engaged with at least one separated waist portion at a predetermined position by the engaging portion and is extended, the length of the non-stretchable region in the left-right direction is more than 20% and less than 50% of the total length of the left-right direction of the waist portion on one side and the waist portion on the other side.

[0051] According to method 5, the wearer's abdomen abuts against the non-stretchable area, thus reducing the feeling of tightness on the abdomen and improving wearing comfort. Furthermore, compared to a case where the lateral length of the non-stretchable area is less than 20% of the total length, the feeling of tightness on the abdomen is reduced, and the ease of waist stretching is also moderately suppressed, thus easily maintaining a fit that adapts to changes in the wearer's waistline. Additionally, compared to a case where the lateral length of the non-stretchable area is more than 50% of the total length, waistline stretch is ensured, allowing the waistline to firmly conform to the wearer's waist.

[0052] (Method 6) Among the absorbent articles described in any of Methods 1 to 5,

[0053] The predetermined position is located on the front side of the waist section in the front-back direction. For the telescopic region of the front waist section, the force used to extend the area of ​​unit width in the vertical direction by a predetermined length in the horizontal direction is greater than that of the telescopic region of the rear waist section.

[0054] According to method 6, when the user wears the absorbent material, when the front waist is grasped, the stretching of the front waist is suppressed, making it less prone to instability. Therefore, the fastener can be stably and closely engaged with the front waist. On the other hand, the back waist can easily stretch more by wrapping around the wearer's buttocks, making it easier to achieve a close fit between the waist and the wearer's back.

[0055] (Method 7) Among the absorbent articles described in any of Methods 1 to 6,

[0056] The absorbent article has an absorbent body, the base end of the fixed part is fixed to the waist part by a fixing part, and the area from the center of the absorbent body to the fixing part in the left-right direction of the waist part is a non-stretchable area from the top to the bottom where the stretchable member does not exist.

[0057] According to method 7, when the user engages the fastener with the waist, the user can grasp the front end of the waist that is separated from the fastener, i.e., the non-stretchable area. The non-stretchable area is not easily unstable, so the fastener can be stably and closely engaged with the waist.

[0058] (Method 8) Among the absorbent articles described in any of Methods 1 to 7,

[0059] The base end of the fixed part is fixed to the waist part by the fixing part. The waist part has a first part that is located on the outer side in the left-right direction than the fixing part, and a second part that is engaged with the engaging part of the fixed part. The absorbent article has a marking part for engaging the fixed part in such a way that the center line that bisects the first part in the vertical direction and the center line that bisects the second part in the vertical direction are located on a straight line along the left-right direction.

[0060] According to method 8, the vertical positions of the first part on the fastening side and the second part on the opposite side are easily aligned, and the first and second parts are easily parallel together in the left-right direction. Therefore, the elastic member of the waist section can easily follow the circumference of the wearer's waist, and the waist section can evenly cover the wearer's waist on both sides. Therefore, discomfort during wearing is less likely to occur.

[0061] (Method 9) Among the absorbent articles described in Method 8,

[0062] The marking portion is shaped along the outer contour of the fixing portion.

[0063] According to method 9, the user can easily attach the fastener to the waist by placing the center line that bisects the first part in the vertical direction and the center line that bisects the second part in the vertical direction on a straight line in the horizontal direction based on the marking part.

[0064] (Method 10) Among the absorbent articles described in any of Methods 1 to 9,

[0065] The absorbent article has a marking portion for engaging the fixing portion at the predetermined position.

[0066] According to method 10, when the user wears the waistband with a predetermined contraction rate based on the marking part, the fastener can easily engage with the waistband in a way that improves the balance of the left and right lengths of the waistband.

[0067] (Method 11) Among the absorbent articles described in any of Methods 1 to 10,

[0068] The absorbent article has an absorbent body, and at a position one side away from the center in the left-right direction of the absorbent body, the base end of the fixing part is fixed to the waist part by a fixing part, and at least one marking part is provided for engaging the fixing part.

[0069] According to method 11, the fastening part and the position (marking part) for engaging the fastening part are concentrated on one side of the waist in the left-right direction. Therefore, for example, the user does not need to go around the fastening part to the front of the absorbent body to engage it, and it is easy to engage the fastening part with the waist.

[0070] ===Implementation Methods===

[0071] Hereinafter, an example of an absorbent article of the present invention will be a disposable diaper in the form of shorts for infants. However, the absorbent article of the present invention is not limited to disposable diapers for infants, but can also be used as a disposable diaper for adults, sanitary shorts, etc.

[0072] ===Structure of Disposable Diaper 1===

[0073] Figure 1 It is a three-dimensional view of a disposable diaper 1 (hereinafter referred to as "diaper") in its worn state, and is a three-dimensional view obtained from one side in the left-right direction. Figure 2 This is a top view of the diaper 1 in its natural state, observed from the ventral side (20 sides). Figure 3 This is a top view of the diaper 1 in its unfolded and elongated state, viewed from the non-skin side. Figure 3 The center line CC of the triangle is the center line in the left-right direction when it is in its extended state. Furthermore, Figure 3 It shows Figure 1 and Figure 2 The shorts-type diaper 1 is shown in its unfolded and stretched state.

[0074] "Natural state" refers to the state of diaper 1 after being placed for a predetermined time. For example, diaper 1, taken out of its packaging, has its back waist section 30 pulled outwards to the left and right, causing the waist sections 20 and 30 to be in an "extended state." This extended state is maintained for 15 seconds, after which the pulling of diaper 1 is released and it is placed on a flat surface such as a table. Then, the state of being laid flat on such a surface for 5 minutes is defined as the natural state.

[0075] "Unfolded state" refers to a state in which the joints 2a and 2b of the two sides of the diaper 1 in its shorts-type state—that is, the two side ends of the abdominal waist section 20 and the two side ends of the back waist section 30—are separated and opened, allowing the diaper 1 to be unfolded as a whole in a flat plane. "Extended state" refers to a state in which the elastic members of the diaper 1 are extended to the point where the wrinkles of the diaper 1 are no longer visually discernible. Specifically, it refers to a state in which the extension is such that the dimensions of each component constituting the diaper 1 (such as the abdominal waist section 20 described later) are the same as or close to the dimensions of a single component.

[0076] exist Figure 1 and Figure 2In the shorts-style configuration shown, the diaper 1 has mutually orthogonal vertical, horizontal, and front-back directions, and forms a waist opening BH and a pair of leg openings LH. In the vertical direction, the waist opening BH side is designated as the upper side, and the crotch side as the lower side. In the front-back direction, the wearer's abdominal side is designated as the front side, and the wearer's back side as the back side. Furthermore, the direction in which the materials constituting the diaper 1 are layered is called the thickness direction; the side in the thickness direction that contacts the wearer is called the skin side, and the side opposite to the skin side is called the non-skin side. Moreover, the thickness direction is also along the front-back direction in its natural state.

[0077] Diaper 1 is a so-called 3-piece type, having an absorbent body 10, a ventral waist section 20, and a dorsal waist section 30. The ventral waist section 20 covers the wearer's ventral side, and the dorsal waist section 30 covers the wearer's dorsal side. Diaper 1 also has a fastening section 5.

[0078] exist Figure 3 In the unfolded state of the diaper 1 shown, the ventral waist portion 20 and the dorsal waist portion 30 are arranged along their length in the left-right direction of the diaper 1. Furthermore, the end of the absorbent body 10 along its length is positioned at the center of the ventral waist portion 20 in the left-right direction, and the end of the absorbent body 10 along its length is positioned at the center of the dorsal waist portion 30 in the left-right direction, thus forming the crotch portion 40. The absorbent body 10 is positioned closer to the skin than the ventral waist portion 20 and the dorsal waist portion 30.

[0079] Will Figure 3 The diaper 1 in its unfolded state, with the absorbent body 10 folded along its length along the vertical direction, is folded at approximately the center CL of the absorbent body 10. The two ends of the ventral waist portion 20 and the two ends of the dorsal waist portion 30 in the left-right direction are joined using heat welding, ultrasonic welding, or the like, forming a pair of joints 2a and 2b. Thus, it becomes... Figure 1 and Figure 2 The diaper 1 is shown in a shorts-like configuration. The joint 2a is a joint on one side in the left-right direction, and the joint 2b is a joint on the other side in the left-right direction.

[0080] Furthermore, the diaper 1 in this embodiment is for infants and young children, therefore, in the unfolded and stretched state of the diaper 1 ( Figure 3Under these conditions, the maximum length of diaper 1 (from the upper end of the abdominal waist portion 20 to the upper end of the back waist portion 30) is preferably between 395 mm and 425 mm. The length (vertical direction) of the side joints 2a and 2b is preferably between 88.5 mm and 98.5 mm. However, diapers for infants of sizes outside the above range are also acceptable.

[0081] In this embodiment, the portion overlapping the pair of joints 2a and 2b in the vertical direction is designated as the waist portion 20 and 30. The waist portion 20 and 30 have an abdominal waist portion 20 as one side of the waist portion and a back waist portion 30 as the other side of the waist portion. Furthermore, the portion below the waist portion 20 and 30 is designated as the crotch portion 40. Alternatively, the absorbent article may be an outer material located on the non-skin side of the absorbent body 10, with protrusions extending downward from the abdominal waist portion 20 and the back waist portion 30. The protrusions can cover the wearer's lower abdomen and buttocks. In addition, the abdominal waist portion 20 and the back waist portion 30 are not limited to being separate components; the crotch portion may be an outer material with an outer member between the abdominal waist portion 20 and the back waist portion 30, and the abdominal waist portion 20 and the back waist portion 30 may be a continuous single component.

[0082] The absorbent body 10 has: an absorbent body 11, a liquid-permeable top sheet 12, a second sheet 13, a side sheet 14, a liquid-impermeable back sheet 15, and an outer cover sheet 16. The top sheet 12 is disposed on the skin side of the absorbent body 11, the second sheet 13 is disposed between the top sheet 12 and the absorbent body 11, the side sheet 14 is disposed on the skin side of the absorbent body 11 and the second sheet 13, the back sheet 15 is disposed on the non-skin side of the absorbent body 11, and the outer cover sheet 16 is disposed on the non-skin side of the back sheet 15.

[0083] The absorbent body 11 is roughly rectangular in shape when viewed from above, and includes an absorbent core 11A that absorbs and retains excretory fluids such as urine, and a liquid-permeable core cover (not shown) covering the absorbent core. Examples of the absorbent core 11A include an absorbent core (a molded form of liquid absorbent fiber) formed from pulp containing a superabsorbent polymer (SAP) into a predetermined shape, such as an absorbent core (a molded form of liquid absorbent fiber) that is roughly hourglass-shaped when viewed from above, and a so-called SAP sheet formed from a sheet of superabsorbent polymer (SAP). Alternatively, the absorbent core 11A may be formed by overlapping a SAP sheet and a molded form of liquid absorbent fiber along the thickness direction; for example, it may be an absorbent core 11A with a structure in which a SAP sheet, a molded form of liquid absorbent fiber, and a SAP sheet are sequentially overlapped from the skin side in the thickness direction. The length of the absorbent core 11A of the diaper 1 in the left-right direction is approximately the same as the length of the absorbent body 11 in the left-right direction. Examples of the core cover include a liquid-permeable sheet such as thin cotton paper or non-woven fabric. Alternatively, it can also be a structure without a core-coated sheet.

[0084] like Figure 3 As shown, the leg folding stretch members 17 provided on both sides of the absorbent body 10 in the left-right direction constitute leg pleats. In the shorts-type diaper 1, the leg pleats are provided along each leg opening LH, and the diaper 1 conforms to the wearer's leg circumference by stretching the leg folding stretch members 17. The leg folding stretch members 17 of the diaper 1 use multiple elastic bands, for example, to fix the outer sheet 16, which is folded back inwards in the left-right direction to each other, between the back sheet 15 and the outer sheet 16 in a state of elongation along the length direction of the absorbent body 10.

[0085] On both sides of the absorbent body 10 in the left-right direction, there are leak-proof elastic members 18 located inside the leg opening elastic members 17. Multiple leak-proof elastic members 18 are fixed in a lengthwise extended state between the two side panels 14 folded back in the left-right direction, forming a pair of leak-proof sections along the length direction. When the diaper 1 is worn, the leak-proof sections, utilizing the elasticity of the leak-proof elastic members 18, stand upright towards the wearer's skin and conform to the wearer's crotch area.

[0086] Examples of leg circumference expansion member 17 and leak-proof wall expansion member 18 include elastic cords, elastic sheets, etc.

[0087] The ventral waist section 20 has a skin-side sheet 21, a non-skin-side sheet 22, and multiple telescopic members 23 that extend and retract in the left-right direction. The skin-side sheet 21 and the non-skin-side sheet 22 are joined together by bonding units such as hot melt adhesive, heat, or ultrasonic welding. The skin-side sheet 21 and the non-skin-side sheet 22 are sheet members of approximately the same size and shape, and in this embodiment, they have a generally rectangular shape. The non-skin-side sheet 22 is positioned on the non-skin side closer to the skin-side sheet 21. As the skin-side sheet 21 and the non-skin-side sheet 22, non-telescopic sheets such as SMS nonwoven fabric (spunbond / meltblown / spunbond nonwoven fabric), spunbond nonwoven fabric, hot air nonwoven fabric, dot-bonded nonwoven fabric, stretch nonwoven fabric, plastic sheet, perforated plastic sheet, and laminates of the above materials can be used.

[0088] Multiple telescopic members 23 of the abdominal waist section 20 are arranged vertically between the skin side panel 21 and the non-skin side panel 22, and are fixed in an extended state in the lateral direction. Therefore, the abdominal waist section 20 stretches in the lateral direction to fit the wearer's waist. Examples of telescopic members 23 include rubber, spandex, etc. In the abdominal waist section 20, the non-skin side of the non-skin side panel 22 has a latching portion 25 that can latch with the latching portion 51 (described later) of the fastening portion 5. The latching portion 25 is a so-called target area, and a non-woven fabric sheet can be exemplified, for example. In addition, when a male member of a hook and loop fastener is used for the latching portion 51, it is desirable to select a latching portion corresponding to the latching portion 51, such as a female member of a hook and loop fastener used for the latching portion 25. Furthermore, instead of providing other components on the non-skin side of the non-skin side piece 22, the non-skin side piece 22 can be made of a component (such as non-woven fabric) that can engage with the engaging part 51, so that the engaging part 51 directly engages with the non-skin side of the non-skin side piece 22. However, contrary to the above, the engaging part 25 of the abdominal waist part 20 can be a male component of the hook and loop fastener, and the engaging part 51 of the fastening part 5 (the side opposite to the abdominal waist part 20) can be a non-woven fabric sheet, a female component of the hook and loop fastener, etc.

[0089] The back-side waist section 30 has a skin-side sheet 31, a non-skin-side sheet 32, and multiple telescopic members 33 that extend and retract in the left-right direction. The skin-side sheet 31 and the non-skin-side sheet 32 ​​are joined together by bonding units such as hot melt adhesive, heat, or ultrasonic welding. The skin-side sheet 31 and the non-skin-side sheet 32 ​​are sheet members of approximately the same size and shape, and in this embodiment, they have a generally rectangular shape. The non-skin-side sheet 32 ​​is positioned on the non-skin side closer to the skin-side sheet 31. For example, non-telescopic sheets such as polypropylene SMS nonwoven fabric (spunbond / meltblown / spunbond nonwoven fabric), spunbond nonwoven fabric, hot air nonwoven fabric, dot-bonded nonwoven fabric, stretch nonwoven fabric, plastic sheet, perforated plastic sheet, and laminates of the above materials can be used for the skin-side sheet 31 and the non-skin-side sheet 32.

[0090] Multiple telescopic members 33 of the back waist section 30 are arranged vertically between the skin side panel 31 and the non-skin side panel 32, and are fixed in an extended state in the left-right direction. Therefore, the abdominal waist section 20 and the back waist section 30 extend and contract in the left-right direction respectively, conforming to the wearer's waist. Examples of telescopic members 23 and 33 include elastic members made of rubber, spandex, etc.

[0091] The attachment part 5 is a so-called protrusion (grip) member, which is used to form a waist opening when the ventral waist part 20 is cut off. Figure 4 yes Figure 3 An enlarged view of part X in the diagram. In the fixing part 5 of this embodiment, the base end portion of the fixing part 5 ( Figure 3 The front end of the fastening part 5 is fixed to one side of the left-right direction (as shown in the image) at a position closer to the center of the left-right direction than the abdominal waist part 20. Figure 3 The other side (in the left and right directions) has a locking part 51 that can be detachably locked onto the non-skin side of the abdominal waist 20.

[0092] The fastening part 5 is a gripping part for the wearer, or a person attempting to put on the diaper 1 (hereinafter also referred to as "the wearer, etc."), to grasp and perform actions. Therefore, it is preferable that the fastening part 5 has strength sufficient to prevent it from breaking on its own. As the fastening part 5, various films such as plastic film, nylon film, non-woven fabric, and films formed by laminating non-woven fabric can be used, for example. In this embodiment, the fastening part 5 of the diaper 1 uses a sheet-like component consisting of three layers of non-woven fabric of the same size overlapped on both sides of a plastic film.

[0093] The engaging portion 51 is provided on the skin side of the fixing portion 5 and is a component that can be detachably engaged with the non-skin side of the abdominal waist portion 20 (specifically, the engaged portion 25). Examples of engaging portions 51 include male components of hook and loop fasteners, adhesive sheets, and other adhesive materials. The engaging portion 51 in this embodiment is generally rectangular in shape, but it can also be any shape such as circular.

[0094] like Figure 4 As shown, the fastening part 5 is fixed to the abdominal waist part 20 using the fixing part F1 and the auxiliary fixing part F2. In this embodiment, the fixing part F1 and the auxiliary fixing part F2 are welded parts formed by joining the fastening part 5 and the abdominal waist part 20 along the thickness direction using methods such as heat welding and ultrasonic welding. The fastening part 5 is mainly fixed to the abdominal waist part 20 by the fixing part F1, and the auxiliary fixing part F2 assists in the fixation based on the fixing part F1.

[0095] ===How to put on diaper 1===

[0096] The diaper 1 of this embodiment can be worn by pre-cutting the abdominal waist part 20 at the cutting guide so that one side in the left and right direction is in the form of a so-called belt-type diaper (without the leg opening LH) and the other side in the left and right direction is in the form of a shorts-type diaper (with the leg opening LH).

[0097] First, the abdominal waist section 20 is cut at the cutting guide section, so that the wearer's other leg (the wearer's right leg in diaper 1) passes through the leg opening LH on the other side (in the form of a shorts-type diaper) in the left-right direction. Then, the diaper 1 is lifted up to the wearer's crotch. After that, the locking part 51 of the fastening part 5 is locked onto the abdominal waist section 20 in a way that fits the wearer's waist, forming a waist opening, thus achieving the wearing state.

[0098] By wearing the diaper in this way, even for infants who have difficulty passing their legs through the leg openings LH on both sides due to their legs moving around, as long as one leg of the wearer can pass through the leg opening LH, it can be easily put on using the fastening part 5 (hooking part 51). In addition, when the wearer is wearing diaper 1, there may be situations where it is difficult to wear a regular strap diaper (a diaper with straps on both sides in the left and right directions) in the bathroom, etc. However, by making one side of the diaper shorts-like and the other side fastening part 5 (strap type), it can be put on easily, and the fit around the waist can be easily adjusted.

[0099] Furthermore, when removing the used diaper 1 from the body, the abdominal waist section 20 is separated at the cutting guide section, and one side of the diaper 1 in the left and right directions is removed from the wearer's body. The other leg is pulled out from the leg opening LH on the other side in the left and right directions. Thus, the diaper 1 can be removed from the wearer's body.

[0100] ===Regarding the 20-degree cut in the ventral waist area===

[0101] use Figure 5 and Figure 6 This describes the cutting of the ventral side waist section 20. Figure 5 This diagram illustrates the separation of the ventral waist section 20 and the formation of the waist opening. Figure 6 This diagram illustrates the action of cutting off the ventral waist section 20. Figure 5 This is an explanation Figure 4 A diagram of the structure of the cross-section viewed from direction AA. Furthermore, Figure 5 and Figure 6 This is a schematic diagram; dimensions and other details may not be accurate.

[0102] Figure 5 A is Figure 1 Diaper 1 in the form of shorts, as shown. That is, the ventral waist portion 20 is not cut off, and the ventral waist portion 20 and the dorsal waist portion 30 form a continuous waist opening through the joints 2a and 2b. Figure 5 B and Figure 6 A indicates from Figure 5 The state shown in Figure A is the state of grasping the front end of the fixing part 5 and pulling it up towards the non-skin side.

[0103] Then, as Figure 6 As shown in Figure A, grasp the waistline 20 with one hand and the anchoring part 5 with the other hand, and pull them outwards to the left and right respectively. Thus, as... Figure 5 C and Figure 6 As shown in Figure B, the ventral waist portion 20 is cut along the cutting guide, separating it into one side and the other side in the left-right direction. The "cutting guide" refers to the guide portion used when at least a partial section of the ventral waist portion 20 is cut. In the diaper 1, the fixing portion F1, which secures the ventral waist portion 20 and the fixing portion 5, functions as the cutting guide. Specifically, when... Figure 6As shown in Figure A, when the abdominal waist section 20 and the fixing part 5 are held separately and pulled to the left and right, firstly, the force generated by the pulling is concentrated at the cutting guide point K, which is located at the frontmost end of the cutting guide (fixed part F1). Then, the force is transmitted along the inclined part that slopes upward from the cutting guide point K and is inclined downward from the cutting guide point K and is inclined to the base end. Then, the abdominal waist section 20 is cut off with the other end CE in the left and right direction of the fixing part F1 as the boundary, separating the abdominal waist section 20 into a part with the fixing part 5 and a part without the fixing part 5.

[0104] Then, as needed, such as Figure 5 As shown in Figure D, the engaging portion 51 of the fastening portion 5 engages with the engaged portion 25 of the abdominal waist portion 20, thereby forming the waist opening of the diaper 1. The engaging portion 51 can be engaged with the engaged portion 25 in such a way that one side of the abdominal waist portion 20, separated in the left-right direction, overlaps with the other side in the front-back direction (thickness direction), or the engaging portion 51 can be engaged with the engaged portion 25 in a way that the two sides of the abdominal waist portion 20 do not overlap in the front-back direction (thickness direction). By adjusting the position in which the engaging portion 51 engages, the size of the waist opening of the diaper 1 can be adjusted.

[0105] However, the cutting guide is not limited to the fixing part F1; it can also be provided with an easy-tear line, a low weight-per-unit-area part, or other cutting guides that can guide the cutting of the abdominal waist 20. Furthermore, the diaper 1 may not even have a cutting guide. Alternatively, the wearer or others can use a knife or their hands to cut the abdominal waist 20 at the desired location.

[0106] ===Regarding the elasticity of the waist at 20 and 30 degrees===

[0107] Figure 7 This is an explanatory diagram of the marking part 60 for engaging the fixing part 50. Figure 8 A and Figure 8 B is an explanatory diagram regarding the contraction rate of the waist at 20 and 30 degrees.

[0108] Here, the fastening part 50 is engaged with the engaging part 51 at the "predetermined position p0" of the ventral waist part 20 separated from the cutting guide part (fixing part F1), thereby forming the waist opening part BH. Figure 5 D、 Figure 8 A) is called the "baseline wearing state". For example... Figure 7As shown, in diaper 1, a marking part 60 for engaging the fastening part 50 is provided at a predetermined position p0.

[0109] In this standard wearing state, the length WN in the left and right directions of the waist (20, 30) is... Figure 8 B) Divide by the length W100 in the left-right direction when the waist is at its maximum extension at 20 and 30 ( Figure 8 A) The resulting proportion is Figure 8 The shrinkage rate at point B (N% = WN / W100×100) is calculated as follows.

[0110] Furthermore, the joints 2a and 2b have widths in the left-right direction. Therefore, in the case of absorbent articles having joints 2a and 2b, such as the diaper 1 of this embodiment, the lengths (WN, W100) of the waist portions 20 and 30 in the left-right direction refer to the lengths in the left-right direction from the inner end (other end) of one side of the joint 2a in the left-right direction to the inner end (one end) of the other side of the joint 2b in the left-right direction.

[0111] In addition, the length in the left and right directions when the waist parts 20 and 30 are stretched to their maximum extent refers to the length when the waist parts 20 and 30 are stretched to the point where the folds of the waist parts 20 and 30 are no longer visually discernible. It also refers to the length when the dimensions of the skin side panels 21 and 31 and the non-skin side panels 22 and 32 that make up the waist parts 20 and 30 are consistent with or close to the dimensions of their individual components (so-called pattern dimensions).

[0112] In absorbent articles with elastic members 23 and 33 in the waist sections 20 and 30, the waist sections 20 and 30 fit the wearer's waist in a state that shrinks in the left and right directions from their maximum extended state (shrinkage rate of 100%). For example, in a general shorts-type absorbent article that does not have a fastening part 50, unlike the diaper 1 of this embodiment, it can be statistically seen that it is worn at about 55% of its maximum extended length in the left and right directions (shrinkage rate of 55%).

[0113] Therefore, in the diaper 1 of this embodiment, the following is achieved at a predetermined shrinkage rate of 55% or more. For example... Figure 8 As shown in B, at the center position 5C in the vertical direction of the fixing part 5 (that is, the center position in the vertical direction of the joint parts 2a and 2b), the length (WN / 2) of the waist parts 20 and 30 from the center C in the left-right direction to one side in the left-right direction is the same as the length (WN / 2) of the waist parts 20 and 30 from the center C in the left-right direction to the other side in the left-right direction.

[0114] Furthermore, the center C in the left-right direction of the waist portions 20 and 30 corresponds to the center in the left-right direction of the absorbent body 11 (absorbent main body 10). Additionally, in the case of absorbent articles having joints 2a and 2b, such as the diaper 1 of this embodiment, the end of the waist portions 20 and 30 to one side in the left-right direction refers to the inner end (other side end) of the joint 2a to one side in the left-right direction, and the end of the waist portions 20 and 30 to the other side in the left-right direction refers to the inner end (one side end) of the joint 2b to the other side in the left-right direction.

[0115] Preferably, under this predetermined shrinkage rate corresponding to the wearing state, the left and right lengths of the waist sections 20 and 30, extending outwards from the absorbent body 11 located at the wearer's crotch, are consistent. This results in better left-right balance of the waist sections 20 and 30 during wear, reducing the likelihood of discomfort for the wearer. For example, it prevents a situation where one side of the waist sections 20 and 30 is more secure than the other side.

[0116] In the diaper 1 of this embodiment, the "predetermined shrinkage rate" is determined based on the average waist size of the intended wearer. For example, in the S-size diaper 1, in the standard wearing state (with the fastening part 5 engaged at the predetermined position P0), the circumference of the waist portions 20 and 30 at a shrinkage rate of 66% corresponds to the average waist size of the wearer. Therefore, the predetermined shrinkage rate of the S-size diaper 1 is 66%. Furthermore, in the M-size diaper 1, in the standard wearing state, the circumference of the waist portions 20 and 30 at a shrinkage rate of 74% corresponds to the average waist size of the wearer. Therefore, the predetermined shrinkage rate of the M-size diaper 1 is 74%. The predetermined shrinkage rates for both sizes are higher than 55%.

[0117] Furthermore, in the diaper 1 of this embodiment, for the waist sections 20 and 30 in the contracted state, the elongation force acting on the waist sections 20 and 30 when they stretch in the left and right direction to a contraction rate 10% higher than 55% is defined as Fa. Additionally, for the waist sections 20 and 30 in the contracted state, the elongation force acting on the waist sections 20 and 30 when they stretch in the left and right direction to a certain contraction rate is defined as Fb. In this case, the value obtained by dividing the elongation force Fa by the elongation force Fb is 1.8 or higher (Fa / Fb≥1.8).

[0118] Therefore, compared to cases where the elongation force ratio (Fa / Fb) is less than 1.8, the force (constant elongation stress) required to elongate the waist sections 20 and 30 is greater. Thus, even if the wearer's waist circumference increases due to changes in posture, eating, or breathing, the elongation of the waist sections 20 and 30 can be moderately suppressed, maintaining a snug fit. In other words, when the wearer's waist circumference increases, the force exerted on the wearer's body from the waist sections 20 and 30 is greater, maintaining a snug fit. Therefore, slippage of the diaper 1 and leakage of excrement during wear can be prevented.

[0119] Furthermore, the diaper 1 of this embodiment, which has the fastening part 50, is generally in a state where the abdominal waist part 20 is separated at the cutting guide part (fastening part F1) (see reference). Figure 6 B) for wearing. Therefore, unlike conventional shorts-type diapers where the waist section is not separated, the user (protector, etc.) does not need to significantly expand the waist section while inserting the wearer's (infant's) legs. In other words, in diaper 1 where the fastening part 5 engages with at least one separated waist section 20, 30 to form the waist opening BH, the probability of significantly expanding the waist section 20, 30 during wearing is low. Therefore, even if the elongation force ratio (Fa / Fb) is set to 1.8 or higher, the user is unlikely to feel difficulty in wearing diaper 1. Instead, only one leg of the crawling infant needs to pass through the leg opening LH from the waist opening BH, making it easy to feel the ease of wearing. However, for diaper 1 of this embodiment, it is also possible to insert the wearer's legs from the waist opening BH to the leg opening LH without separating the waist section 20, 30, just like conventional shorts-type diapers.

[0120] Furthermore, the relationship between the elongation force ratio (Fa / Fb≥1.8) is valid as long as the shrinkage rate is 55% or higher and the shrinkage rate is 10% higher than that shrinkage rate. Therefore, even if the relationship between the elongation force ratio does not hold at other shrinkage rates of 55% or higher and at other shrinkage rates that are 10% higher than other shrinkage rates, this is still included in the absorbent articles of the present invention.

[0121] Furthermore, the absorbent article that engages with at least one separated waist section to form a waist opening is not limited to the diaper 1 of this embodiment, but may also have the following structure.

[0122] For example, the absorbent material could be provided with a fastening part 5 not only on one side of the abdominal waist section 20 in the left-right direction, but also on the other side of the abdominal waist section 20 in the left-right direction. In this case, the state in which the two parts of the abdominal waist section 20 are separated and the two fastening parts 5 are engaged in their respective predetermined positions is defined as the standard wearing state.

[0123] Alternatively, the fixing part 5 can be fixed to the back waist part 30 by the fixing part F1 and engaged with the back waist part 30.

[0124] Alternatively, the absorbent article may be such that, only on one side in the left-right direction, the ventral waist portion 20 and the dorsal waist portion 30 are joined by a joint, and on the opposite side, the ventral waist portion 20 and the dorsal waist portion 30 are separated, with a fastening portion 5 provided. Alternatively, the absorbent article may be such that, on both sides in the left-right direction, the ventral waist portion 20 and the dorsal waist portion 30 are separated, with two fastening portions 5 provided. In the above cases, the fastening portion 5 can be fixed in the middle of the waist portions 20 and 30 using the fastening portion F1, as in the diaper 1 of this embodiment, or the fastening portion 5 can be fixed at the separated front end of the ventral waist portion 20 or the dorsal waist portion 30, as in a belt-type diaper.

[0125] Alternatively, the ventral waist section 20 and the dorsal waist section 30 can be constructed from a single continuous cylindrical component.

[0126] In this embodiment, the diaper 1 is passed through with the abdominal waist section 20 and the back waist section 30 joined together by the joints 2a and 2b. The user removes the diaper 1 from the packaging and separates the abdominal waist section 20 at the fixing part F1, but this is not a limitation. Alternatively, the diaper 1 can be stored in the packaging with the waist sections pre-separated by the fastening part.

[0127] Figure 9 A~ Figure 9 C is an explanatory diagram illustrating the method for measuring the elongation and contraction forces at waist 20 and 30. Figure 10 A and Figure 10 B is a graph showing the measurement results of the elongation and contraction forces of diaper 1 of size S. Figure 11 A and Figure 11 B is a graph showing the measurement results of the elongation and contraction forces of diaper 1 of size M.

[0128] In practice, diapers of sizes S and M from the prepared embodiment (this embodiment), and diapers of sizes S and M from the comparative example were used as samples, and the following measurements were performed using a tensile testing machine 70. The comparative example diaper is a general shorts-type diaper (commercially available) worn without a fastening part and with the waist section not separated. Regarding the diaper of the embodiment, the abdominal waist section 20 was cut off at the fastening part F1, and the fastening part 5 was engaged at a predetermined position P0 (marking part 60), and measurements were performed in the above-described standard wearing state.

[0129] As the tensile testing machine 70, measurements were performed using an Instron tensile testing machine (model: 5965) or equivalent. First, as... Figure 9 As shown in Figure A, the initial distance L0 between the pair of chucks (fixed clamps) 71 separated in the stretching direction is adjusted to match the length of the waist section of the sample, to a length that is neither too loose nor too loose. Since this is for infant diapers, L0 is set to 130 mm.

[0130] Next, the waist section (20, 30) of the sample (diaper 1) in its natural state is attached to the chuck 71. As previously stated, "natural state" refers to the state in which the sample has been placed without load for a predetermined time. The end of the waist section (20, 30) on one side of the chuck 71 in the left-right direction is attached, and the end of the waist section (20, 30) on the other side of the chuck 71 in the left-right direction is attached. In the case of samples with joints (2a, 2b), the width direction of the outer side of the chuck 71 in the stretching direction (with...) is... Figure 9 The sample is set in the center of the paper (in an orthogonal direction).

[0131] Next, the gap between the pair of chucks 71 is separated along the stretching direction at a speed of 100 mm / min. The waist portion (20, 30) of the sample is stretched in the left-right direction until the distance between the pair of chucks 71 reaches a predetermined length. For example, the stretching starts from the shrinkage rate corresponding to the minimum waist of the wearer and extends to at least the shrinkage rate corresponding to the maximum waist of the wearer. In this case, for size S, the stretching is from the initial length (130 mm) to a length of 242 mm, and for size M, the stretching is from the initial length (130 mm) to a length of 250 mm.

[0132] Next, starting from the elongated state of the waist (20, 30), the gap between the pair of chucks 71 is brought closer at a speed of 100 mm / min until the distance between the pair of chucks 71 returns to the initial distance L0.

[0133] Repeat this cycle twice. Then, during the stretching phase of the second cycle, record the contraction rate of the elongated waist (the length of the waist in the left-right direction) and the elongation force applied to the waist (the force required to elongate the waist to that length). Similarly, during the contraction phase of the second cycle, record the contraction rate of the contracted waist (the length of the waist in the left-right direction) and the contraction force applied to the waist (the force required to contract the waist to that length).

[0134] The actual measured results are shown in Figure 10 A and Figure 11 The graph of A. The horizontal axis of the graph represents the shrinkage rate of the waist area, and the vertical axis represents the measured load (N). Figure 10 A represents the results of the embodiments and comparative examples with dimension S. Figure 11 A represents the results of the embodiments and comparative examples with size M.

[0135] according to Figure 10 A and Figure 11 The elongation force curve of Example A (the curve rising to the right, the curve of constant elongation stress during elongation) shows that, compared to the comparative example, the slope of the change in elongation force relative to the shrinkage rate is larger in the Example. In other words, it can be seen that, compared to the comparative example, the increase rate of elongation force is also higher when the shrinkage rate is 10% higher in the Example, thus appropriately suppressing the ease of elongation at the waist 20 and 30. Therefore, it is easier to maintain a fit even when the wearer's waist circumference increases.

[0136] Specifically, an approximate quadratic curve was derived from the elongation force measurements (graphs) of the S-size embodiments and comparative examples. The elongation force at 66% shrinkage (a certain shrinkage rate) and at 76% shrinkage (a shrinkage rate 10% higher than a certain shrinkage rate) were calculated and summarized. Figure 10 Table B. In the comparative example, the value obtained by dividing the elongation force (7.2 N) at 76% shrinkage rate by the elongation force (4.4 N) at 66% shrinkage rate is "1.64", which is less than 1.8. On the other hand, in the embodiment, the value obtained by dividing the elongation force (6.1 N) at 76% shrinkage rate by the elongation force (3.3 N) at 66% shrinkage rate is "1.85", which is greater than 1.8.

[0137] Similarly, an approximate quadratic curve was derived from the elongation force measurements (graphs) of the M-size embodiments and comparative examples. The elongation force at 74% shrinkage (a certain shrinkage rate) and at 84% shrinkage (a shrinkage rate 10% higher than a certain shrinkage rate) were calculated and summarized. Figure 11Table B. In the comparative example, the value obtained by dividing the elongation force (8.8 N) at 84% shrinkage rate by the elongation force (6.0 N) at 74% shrinkage rate is "1.47", which is less than 1.8. On the other hand, in the embodiment, the value obtained by dividing the elongation force (7.3 N) at 84% shrinkage rate by the elongation force (3.9 N) at 74% shrinkage rate is "1.87", which is greater than 1.8.

[0138] Based on the above results, for embodiments where the elongation force obtained by dividing the elongation force at a shrinkage rate 10% higher than a certain shrinkage rate by the elongation force at a certain shrinkage rate (64% for size S, 74% for size M) is 1.8 or higher, the ease of stretching at the waist can be moderately suppressed compared to comparative examples that do not follow this pattern (general shorts-type diapers). Therefore, it can be concluded that it is easy to maintain a fit that adapts to changes in the wearer's waist circumference.

[0139] Alternatively, for a given shrinkage rate and a shrinkage rate 10% higher than that shrinkage rate, an approximate curve can be obtained from the elongation force measurement results, as described above. The elongation force at each shrinkage rate can then be calculated from this approximate curve, and the elongation force ratio can be calculated. Alternatively, during measurements using the tensile testing machine 70, the following can be obtained: Figure 9 B shows the measured value of elongation force at a shrinkage rate A%, and as shown in Figure B, the measured value of elongation force at a shrinkage rate A% is as follows: Figure 9 C shows the measured elongation force at a shrinkage rate A+10% higher than a certain shrinkage rate, and the ratio of elongation force is calculated. The same applies to the shrinkage force discussed later.

[0140] Furthermore, as mentioned above, the relationship between the elongation force ratio (Fa / Fb ≥ 1.8) is acceptable as long as the shrinkage rate is 55% or higher and the shrinkage rate is 10% higher than that shrinkage rate. The telescopic members 23 and 33 of the waist portions 20 and 30 are elastic members. Therefore, as can be seen from the graph of the measurement results, the stress change of the waist portions 20 and 30 increases approximately proportionally when they are stretched to a predetermined length. Therefore, it is considered that, in the embodiment, the relationship between the elongation force ratio is also valid at shrinkage rates other than a certain shrinkage rate (S dimension is 64%, M dimension is 74%). On the other hand, it is considered that, in the comparative example, the relationship between the elongation force ratio is not valid at shrinkage rates other than a certain shrinkage rate (S dimension is 64%, M dimension is 74%).

[0141] Furthermore, in this embodiment, a predetermined shrinkage rate (64% for size S, 74% for size M) is set as the shrinkage rate that provides optimal balance in the lateral length of the waist portions 20 and 30 relative to the absorber 11 under the baseline wearing condition. In other words, the relationship between the elongation force ratio (Fa / Fb ≥ 1.8) holds true at both the predetermined shrinkage rate and a shrinkage rate 10% higher than the predetermined shrinkage rate. Therefore, when the waist portions 20 and 30 are worn around the wearer's waist at the predetermined shrinkage rate, the lateral balance of the waist portions 20 and 30 is better, and a fit that adapts to changes in the waistline is achieved. However, the shrinkage rate at which the elongation force ratio relationship holds true may differ from the predetermined shrinkage rate.

[0142] In addition, Figure 10 A, Figure 11 The graph in section A also shows the curve of contraction force (the curve that descends to the left, the curve of return stress during contraction). Compared to the curve of elongation force, the curve of contraction force is lower and the force is weaker. That is to say, even at the same rate of contraction, the force required to contract to that rate of contraction is less than the force required to elongate to that rate of contraction.

[0143] Therefore, the contraction force acting on the waist parts 20 and 30 when they are in an elongated state contracted to a certain contraction rate in the left and right directions is defined as Fc, and the elongation force acting on the waist parts 20 and 30 when they are in an elongated state extend to a certain contraction rate in the left and right directions is defined as Fb. Preferably, the value obtained by dividing the contraction force Fc by the elongation force Fb is 0.8 or less (Fc / Fb≤0.8).

[0144] Therefore, compared to cases where the ratio of contractile force to elongation force (Fc / Fb) is greater than 0.8, the contractile force of the waist sections 20 and 30 can be reduced. Consequently, the force exerted on the wearer's body when the waist sections 20 and 30 contract is smaller, reducing the feeling of tightness around the wearer's waist. Therefore, the wearing comfort of diaper 1 is improved.

[0145] Furthermore, in the diaper 1 of this embodiment, the relationship between the elongation force ratio (Fa / Fb≥1.8) holds true at a certain shrinkage rate and a shrinkage rate 10% higher than that certain shrinkage rate. Therefore, when the waist sections 20 and 30 are worn on the wearer's waist at a certain shrinkage rate, a fit that varies with changes in the waist can be obtained while reducing the feeling of tightness.

[0146] An approximate quadratic curve was derived from the shrinkage force measurement results (curve graphs) of the S-size examples and comparative examples where the shrinkage force was actually measured. The shrinkage force at a 66% shrinkage rate (a certain shrinkage rate) was calculated and summarized. Figure 10Table B. In the comparative example, the value obtained by dividing the shrinkage force (3.6N) at 66% shrinkage rate (4.4N) by the elongation force (4.4N) at 66% shrinkage rate is "0.82", which is greater than 0.8. On the other hand, in the embodiment, the value obtained by dividing the shrinkage force (2.2N) at 66% shrinkage rate (3.3N) by the elongation force (3.3N) at 66% shrinkage rate is "0.67", which is less than 0.8.

[0147] Similarly, an approximate quadratic curve was derived from the measurement results (graphs) of the shrinkage force of the M-size embodiments and comparative examples, and the shrinkage force at a 74% shrinkage rate (a certain shrinkage rate) was calculated and summarized. Figure 10 Table B. In the comparative example, the value obtained by dividing the shrinkage force (5.2 N) at 74% shrinkage rate (6.0 N) by the elongation force (6.0 N) at 74% shrinkage rate is "0.87", which is greater than 0.8. On the other hand, in the embodiment, the value obtained by dividing the shrinkage force (2.5 N) at 74% shrinkage rate (3.9 N) by the elongation force (3.9 N) at 74% shrinkage rate is "0.64", which is less than 0.8.

[0148] The results above show that for examples where the value obtained by dividing the shrinkage force at a certain shrinkage rate (64% for size S and 74% for size M) by the elongation force at a certain shrinkage rate is 0.8 or less, the tightness around the waist can be reduced compared to comparative examples (general shorts-type diapers) where this is not the case.

[0149] Figure 12 This diagram illustrates the engaging portion 25 and the non-stretchable region N. Figure 12 yes Figure 3 A magnified view of a portion of the image.

[0150] As described above, the ventral waist portion 20 has an engaging portion 25 (e.g., a non-woven fabric sheet, a hook and loop fastener, etc.) that can engage with the fastening portion 5. Furthermore, the ventral waist portion 20, being the front side of the waist portion in the front-rear direction, has a non-stretchable region N from its upper end to its lower end where the stretching member 23 is absent. The absence of the stretching member 23 means the following: Figure 12 As shown, there is no stretchable member 23 exhibiting elasticity in the waist sections 20 and 30. Therefore, it is also possible that the stretchable member 23 that does not exhibit elasticity in the waist sections 20 and 30 (e.g., a thin, discontinuous elastic cord that has been cut off, the cut end of the elastic cord that is not fixed to the skin side piece 21 by adhesive, or the non-skin side piece 22) exists in the non-stretchable area N.

[0151] In addition, the area where the telescopic member 23 exists and the waist parts 20 and 30 extend and retract in the left and right directions is called the telescopic area S.

[0152] And, as Figure 12As shown, it is preferable that the engaging portion 25 has a portion that overlaps with the non-telescopic region N in the left-right direction. Alternatively, a portion of the engaging portion 25 may overlap with the telescopic region S in the left-right direction, but it is more preferable that the entire area of ​​the engaging portion 25 overlaps with the non-telescopic region N in the left-right direction.

[0153] Therefore, when the user wears diaper 1 (refer to...) Figure 6 (B) When holding the fastening part 5 with one hand and the engaging part 25 or its vicinity with the other hand, the engaging part 25 is not easily stretched in the lateral direction, and therefore is not easily unstable. Therefore, the user can stably and closely engage the fastening part 5 with the engaging part 25, making it easy to put on.

[0154] Furthermore, there is a concern that if the telescopic member 23 is only present in a portion of the vertical direction of the abdominal waist section 20 where the engaging portion 25 is located, then only that portion is easily pulled outward in the left-right direction, causing the engaging portion 25 to tilt relative to the left-right direction. However, in the non-telescopic region N, the telescopic member 23 is not present in the entire vertical direction of the abdominal waist section 20, making it difficult for the engaging portion 25 to tilt relative to the left-right direction. Therefore, the side of the abdominal waist section 20 closest to the engaging portion 25 (in... Figure 12 The middle part (the other side in the left-right direction) and the part on the side of the waist 20 near the fastening part 5 (the side in the left-right direction) are easy to wear parallel in the left-right direction. Therefore, it is less likely to cause discomfort to the wearer.

[0155] Furthermore, since the engaging portion 25 and the telescopic member 23 are arranged in a large number of areas that do not overlap or are arranged without overlap along the thickness direction, it is possible to suppress the situation where the engaging portion 25 shrinks in the left-right direction due to the telescopic member 23. Therefore, the engaging portion 51 of the fixing portion 5 can be firmly engaged with the flat surface of the engaging portion 25.

[0156] In addition, such as Figure 12 As shown, the non-stretchable area N is preferably located at the center of the absorbent body 11 in the left-right direction on the front (abdominal) side. This allows the non-stretchable area N to contact the wearer's abdomen, preventing the stretchable member 23 from constricting the wearer's abdomen. In particular, infants and young children, who are the wearers of the diaper 1 in this embodiment, have bulging abdomens that easily bulge due to eating and breathing; therefore, the effect of preventing constriction on the abdomen is effectively achieved.

[0157] Furthermore, in the extended state where the fixing part 5 is engaged with at least one of the separated waist parts 20, 30 at a predetermined position P0 using the engaging part 51 (that is, as...), Figure 8As shown in A, under the condition of maximum extension in the baseline wearing state, the following is preferred. That is, preferably, the length (LN) of the non-stretchable region N in the left and right direction is more than 20% and less than 50% of the total length (overall length: W100×2) of the left and right directions of the abdominal waist part 20 and the back waist part 30.

[0158] Therefore, compared to cases where the length LN of the non-stretchable area N is less than 20% of the overall length of the waist sections 20 and 30, the feeling of tightness in the wearer's abdomen can be suppressed more reliably. Furthermore, by increasing the ratio of the non-stretchable area N, the ease of stretching of the waist sections 20 and 30 can be moderately suppressed, making it easier to maintain a fit that adapts to changes in the wearer's waistline. On the other hand, compared to cases where the length LN of the non-stretchable area N is greater than 50% of the overall length of the waist sections 20 and 30, the elasticity of the waist sections 20 and 30 can be ensured, resulting in a fit that conforms to the wearer's waistline.

[0159] Furthermore, in the case of absorbent articles such as diaper 1 having a pair of left and right joints 2a, 2b, the total length (overall length) is the sum of the lengths (W100×2) of the left and right directions of the abdominal waist part 20 and the dorsal waist part 30, respectively, from the inner end of the joint 2a on one side to the inner end of the joint 2b on the other side, with the fastening part 5 engaged in the predetermined position P0.

[0160] In addition, such as Figure 12 As shown, the base end of the fixing part 5 is fixed to the ventral waist part 20 by the fixing part F1. In this case, it is preferable that the region from the center C of the absorbent body 11 to the fixing part F1 in the left-right direction of the ventral waist part 20 is a non-stretchable region N. The ventral waist part 20 can be easily cut off at the fixing part F1 (see reference). Figure 5 C), therefore, the region from the end of the slit in the ventral waist 20 (F1) to the center C of the absorber 11 becomes the non-stretchable region N.

[0161] Therefore, when putting on diaper 1, the user holds the fastening part 5 with one hand and the non-stretchable area N with the other hand. As a result, the non-stretchable area N is not easily unstable, and the user can stably and closely engage the fastening part 5 with the flat non-stretchable area N, making it easy to put on.

[0162] Furthermore, as in this embodiment, the locking position of the fixing part 5, which becomes the reference wearing state, is ( Figure 7 The predetermined position P0 is preferably located in the ventral waist region 20. That is, it is preferable that the force (extension force) for extending the region of unit width in the vertical direction by a predetermined length in the horizontal direction is larger for the extension region S of the ventral waist region 20 compared with the extension region S of the dorsal waist region 30.

[0163] In addition, such as Figure 12 As shown, in the ventral waist section 20, there is a stretchable region Sa on one side of the non-stretchable region N in the left-right direction (between the fixation part 5), and a stretchable region Sb on the other side of the non-stretchable region N in the left-right direction. On the other hand, in the dorsal waist section 30, as... Figure 3 As shown, the stretching area S is located between a pair of joints Sa and Sb in the left and right directions.

[0164] The ventral waist portion 20 has a larger elongation force (the force required for elongation, the constant elongation stress), which moderately suppresses the ease of stretching. Therefore, when the fastener 5 is engaged at the predetermined position P0 on the ventral side, the ventral waist portion 20 is less prone to instability and can be easily and stably engaged. On the other hand, the dorsal waist portion 30 has a smaller elongation force and is easier to stretch. Therefore, the fastener 5 can be engaged at the predetermined position P0 while stretching in a manner that utilizes the dorsal waist portion 30 to wrap around the wearer's buttocks. Thus, the fit of the waist portions 20 and 30 to the wearer's dorsal side can be improved.

[0165] Furthermore, when the elongation force is small, the contraction force also tends to be small, thus moderately suppressing the contraction force of the dorsal waist section 30 (the force required for contraction, the return stress). Therefore, for example, when attempting to put on the diaper 1 with the wearer in a supine position after the ventral waist section 20 has been cut by the cutting guide (fixed part F1), it is possible to prevent the dorsal waist section 30 from contracting excessively, causing the fixing part 5 to go under the wearer's buttocks.

[0166] In the ventral waist section 20 and the dorsal waist section 30, the method for measuring the force used to stretch a unit width area in the vertical direction by a predetermined length in the horizontal direction can be performed using the aforementioned tensile testing machine 70 (manufactured by Instron).

[0167] First, the stretchable area S of the abdominal waist 20 is cut from the diaper 1 and cut to a predetermined size (per unit area) to serve as test piece A. Similarly, the stretchable area S of the back waist 30 is cut to the same size as test piece A to serve as test piece B. For these test pieces A and B, the length when relaxed in the left-right direction (e.g., 25 mm) is used as the measurement interval, and they are clamped by the chuck 71 of the tensile testing machine 70.

[0168] Then, the measuring section is pulled to the left and right at a predetermined speed (e.g., 100 mm / min) until it extends to a predetermined length (e.g., 50 mm). Afterward, the measuring section is contracted at a speed of 100 mm / min until the distance between the chucks returns to its initial length (25 mm). This cycle is repeated multiple times (e.g., twice). In the multiple cycles, the tensile load at the predetermined length is measured, thereby calculating and comparing the elongation forces of test piece A and test piece B. Furthermore, if the stretchable range of the test piece is narrow and it cannot extend to the predetermined length, adjustments can be made by shortening the predetermined length at which the measuring section extends (e.g., changing 50 mm to 40 mm).

[0169] In addition, such as Figure 8 As shown in Figure A, the ventral waist portion 20 has a first portion 201 located laterally outside the fixing portion F1 that fixes the base end of the fastening portion 5, and a second portion 202 for engaging with the engaging portion 51 of the fastening portion 5. That is, the first portion 201 and the second portion 202 are connected by the fastening portion 5 from their separated state, forming the waist opening BH. Preferably, the diaper 1 has a marking portion 60 for engaging the fastening portion 5 in such a way that the center line C1-C1, which bisects the first portion 201 vertically, and the center line C2-C2, which bisects the second portion 202 vertically, are located on a straight line in the left-right direction. In other words, the marking portion 60 is a marker that guides the user to align the center lines C1-C1 and C2-C2 in the vertical direction and make them parallel when engaging the fastening portion 5.

[0170] Therefore, the vertical positions of the first part 201 on the fastening part 5 side of the abdominal waist part 20 and the second part 202 on the opposite side of the fastening part 5 of the abdominal waist part 20 are easily aligned, and the first part 201 and the second part 202 are easily parallel together in the left and right directions. Therefore, the telescopic members 23 and 33 of the waist parts 20 and 30 are easily aligned with the circumference of the wearer's waist. In addition, the waist parts 20 and 30 can cover the wearer's waist evenly on both sides. Therefore, it is less likely to cause discomfort to the wearer. In addition, for example, it can also prevent the situation where the leg opening LH on the first part 201 side becomes smaller because the center line C1-C1 of the first part 201 is inclined downward and outward in the left and right directions relative to the center line C2-C2 of the second part 202 (such as the locking part 25).

[0171] Specifically, such as Figure 7As shown, the marking portion 60 is preferably shaped along the outer contour of the fastening portion 5. In this case, the position of the fastening portion 5 (first portion 201) in the left-right direction and the up-down direction is defined relative to the second portion 202 of the abdominal waist portion 20. Therefore, the marking portion 60 can guide the user to engage the fastening portion 5 in a manner where the center line C1-C1 of the first portion 201 and the center line C2-C2 of the second portion 202 are located on a straight line in the left-right direction.

[0172] Furthermore, the marking portion 60 is not limited to the entire shape along the outer contour of the fixing portion 5, but may also be a partial shape along the outer contour. Additionally, the marking portion 60 may be a line along the outer contour, or it may be a colored portion formed by coloring the inner part of the outer contour. Figure 7 The illustrated marking portion 60 is composed of curves and straight lines, but it can also be constructed by arranging smaller patterns such as dots, stars, and flowers along the outline of the fixing portion 5.

[0173] Figure 13 A and Figure 13 B is a diagram showing a modified example of the marking part 60. Figure 14 A and Figure 14 Figure B shows a modified example of the marking part 60. The marking part 60 is not limited to a shape that follows the outline. Even in the modified example of the marking part 60 described below, the user can be guided to engage with the fixing part 5 in such a way that the center line C1-C1 of the first part 201 of the ventral waist part 20 and the center line C2-C2 of the second part 202 are located on a straight line in the left and right direction.

[0174] It could also be, such as Figure 13 As shown in Figure A, the marking portion 60 consists of a first marking portion 61A (e.g., a black triangle) indicating the engagement position of the fixing portion 5 in the vertical direction, and a second marking portion 61B (e.g., a white triangle) indicating the engagement position of the fixing portion 5 in the horizontal direction. A first marking portion 61A and a second marking portion 61B are provided on each of the abdominal waist portions 20, and a first marking portion 61A and a second marking portion 61B are also provided on each of the fixing portions 5. Therefore, the user can align the first marking portion 61A of the fixing portion 5 and the first marking portion 61A of the abdominal waist portion 20 (so that the vertices of the triangles face each other) in the vertical direction, and can align the second marking portion 61B of the fixing portion 5 and the second marking portion 61B of the abdominal waist portion 20 in the horizontal direction.

[0175] It could also be, such as Figure 13As shown in Figure B, the marking section 60 consists of three patterns 62A and 62B (in this case, a giraffe pattern) divided into three parts along the vertical direction. The marking sections 62A of the upper and lower patterns are located on the ventral side waist section 20, while the marking section 62B of the middle pattern is located on the fixing section 5. Therefore, the user can align the marking section 62B of the pattern on the fixing section 5 with the marking section 62A of the pattern on the ventral side waist section 20 vertically, and can also align the left and right position of the marking section 62B of the middle pattern with the marking sections 62A of the upper and lower patterns. Thus, the pattern is completed and can be appreciated.

[0176] It could also be, such as Figure 14 and Figure 14 As shown in Figure B, the marking portion 60 is constructed by coloring the telescopic member 23 (setting it to a different color from the other telescopic members 23). Alternatively, as... Figure 14 As shown in Figure A, telescopic members 23A and 23B, whose vertical positions are the same as the upper and lower ends of the marking portion 63 provided on the fixing portion 5, are colored to form marking portions 63A and 63B, respectively. Therefore, the user can align the vertical position of the marking portion 63 of the fixing portion 5 based on the colored telescopic members 23A and 23B, and can engage the fixing portion 5 in a manner where the upper and lower ends of the marking portion 63 of the fixing portion 5 are parallel to the colored telescopic members 23A and 23B along the left and right directions.

[0177] Alternatively, it could be, such as Figure 14 As shown in Figure B, multiple telescopic members 23C located at positions overlapping with the marking portion 63 of the fixing portion 5 in the vertical direction are colored to form the marking portion 63C. In this case, the user can also align the vertical position of the marking portion 63 of the fixing portion 5 based on the colored telescopic members 23C, and can engage the fixing portion 5 in a manner where the upper and lower ends of the marking portion 63 of the fixing portion 5 are parallel to the colored telescopic members 23C along the left and right directions.

[0178] In addition, Figure 14 A and Figure 14 In case B, although not shown in the figure, a marking part indicating the engagement position of the fixing part 5 in the left and right directions may be provided.

[0179] Furthermore, the marking section 60 can be formed by printing, embossing, or other methods to make it visible to the user from the non-skin side of the diaper 1.

[0180] Furthermore, the marking portion 60 can be positioned at a location overlapping the fixing portion 5 in the thickness direction, and as follows: Figure 7The fixing part 5 can be rolled up as shown for visual identification, or it can be placed at a position that does not partially or completely overlap with the fixing part 5 in the thickness direction.

[0181] Alternatively, multiple marking sections 60 can be provided for a single fixing section 5.

[0182] Furthermore, in cases where the waist section 20 and 30 have a locking portion 25 (target area), even if the diaper 1 does not have a marking portion 60, the wearer can still lock the fastening portion 5 into the appropriate position on the waist section 20. However, by having a marking portion 60 on the diaper 1, the fastening portion 5 can be locked into a more appropriate position (a position that is not too tight around the wearer's waist and not too loose to prevent leakage).

[0183] Alternatively, the marking part 60 may be a marking part that only indicates the position of the fastener 5 in the left-right direction (e.g., a straight line along the up-down direction).

[0184] Additionally, preferably, the diaper 1 has a marking portion 60 for engaging the fastening portion 5 at a predetermined position P0, which is the reference wearing state.

[0185] Therefore, when the waist sections 20 and 30 are worn on the wearer's waist at a predetermined shrinkage rate or a shrinkage rate close to the predetermined shrinkage rate, the left and right lengths of the waist sections 20 and 30 extending outwards from the absorbent body 11 located at the wearer's crotch are the same or similar. Thus, the left and right balance of the waist sections 20 and 30 is better when worn, and discomfort is less likely to occur during wear.

[0186] Furthermore, preferably, the diaper 1 has a marking portion 60 for engaging the fastening portion 5 with the waist portions 20 and 30 in such a way that, when the waist portions 20 and 30 have a predetermined shrinkage rate, such as Figure 8 As shown in B, at the center position 5C in the vertical direction of the fixation part 5, the length WN / 2 of the waist part 20, 30 (absorbent 11) from the center C in the left-right direction to one side in the left-right direction is the same as the length WN / 2 of the waist part 20, 30 from the center (absorbent 11) in the left-right direction to the other side in the left-right direction.

[0187] Therefore, when the waist sections 20 and 30 are worn on the wearer's waist at a predetermined shrinkage rate or a shrinkage rate close to the predetermined shrinkage rate, the left and right lengths of the waist sections 20 and 30 extending outwards from the absorbent body 11 located at the wearer's crotch are the same or similar. Thus, the left and right balance of the waist sections 20 and 30 is better when worn, and discomfort is less likely to occur during wear.

[0188] In addition, preferably, such as Figure 12 As shown, at a position one side of the center C in the left-right direction of the absorbent body 11, the base end of the fixing part 5 is fixed to the abdominal waist part 20 by the fixing part F1, and at least one marking part 60 is provided for engaging the fixing part 5.

[0189] If the marking portion 60 is positioned away from the center C of the absorbent body 11 (on the side opposite to the fixing portion F1 of the fastening portion 5), the user must reach around the absorbent body 11 with their hand holding the fastening portion 5, making it difficult to wear. Therefore, as described above, by concentrating the fastening portion 5 and the marking portion 60 indicating the engagement position of the fastening portion 5 on one side of the abdominal waist portion 20 in the left-right direction, it is easier to engage the fastening portion 5 with the waist portions 20 and 30. In addition, when engaging the fastening portion 5 with the waist portions 20 and 30, the overlapping portion of the abdominal waist portions 20 does not become excessively long, allowing for material reduction.

[0190] Alternatively, if the diaper 1 has multiple marking portions 60, all marking portions 60 are located on one side (the side of the fastening portion 5) further to the left and right than the center C of the absorbent body 11. In this case, the fastening portion 5 is easy to operate and can further reduce material usage.

[0191] Alternatively, one part of the marking portion 60 may be located on one side (the side of the fastening portion 5) of the absorbent body 11, while the other part of the marking portion 60 may be located on the other side of the absorbent body 11, further to the left and right. In this case, by engaging the fastening portion 5 based on the other part of the marking portion 60, the waist portions 20 and 30 can also fit the wearer with a smaller waist.

[0192] Alternatively, not limited to the above, all the markings 60 may be located on the opposite side (opposite to the fastening part 5) in the left-right direction from the center C of the absorbent body 11. In this case, the waist parts 20 and 30 can also fit the wearer with a smaller waist.

[0193] Furthermore, it is preferable that even if the marking portion 60 is located on the opposite side of the center C of the absorbent body 11 in the left-right direction, the marking portion 60 is also located on the absorbent body 11. In this case, compared to the case where the marking portion 60 is provided on the opposite side of the absorbent body 11 in the left-right direction, it is not necessary to make the fastening portion 5 wrap around to a greater extent, which can reduce the difficulty of wearing. In addition, the portion where the abdominal waist 20 overlaps with each other is also reduced.

[0194] Furthermore, preferably, when the diaper 1 is stretched out, and viewed from the ventral waist portion 20 (one side of the waist portion) in the front-to-back direction, the diaper 1 (absorbent material) appears as follows: Figure 4As shown, the overlapping area W of the non-skin side of the ventral waist 20 and the attachment part 5 overlaps, as... Figure 3 As shown, the overlapping area W is asymmetrically arranged with respect to the center line C in the left-right direction of the diaper 1. In the diaper 1 of this embodiment, the overlapping area W is located on one side closer to the center in the left-right direction and not on the other side closer to the center in the left-right direction, and the overlapping area W is asymmetrical with respect to the center line CC in the left-right direction of the diaper 1.

[0195] In this case, when viewed from the waist side in the front-back direction, the user can easily identify that the diaper 1 has an asymmetrical shape relative to the center line in the left-right direction. Therefore, the user does not need to pay too much attention to wearing the diaper 1 symmetrically on the wearer's body, thus making the wearing of the diaper 1 easier.

[0196] Furthermore, such as Figure 2 As shown, in the natural state of diaper 1, the overlapping area W is asymmetrical with respect to the center line CC in the left-right direction, and diaper 1 is an asymmetrical shape with respect to the center line CC in the left-right direction. Therefore, the user can easily recognize that diaper 1 has an asymmetrical shape in the left-right direction even in the natural state.

[0197] Specifically, when viewing the diaper 1 in its natural state from the ventral waist section 20 in the front-back direction, the length from one side end of the ventral waist section 20 in the left-right direction to the center (CC) of the diaper 1 in the left-right direction is defined as L1, and the length from the other side end of the ventral waist section 20 in the left-right direction to the center (CC) of the diaper 1 in the left-right direction is defined as L2. Preferably, these lengths L1 and L2 are different. In this embodiment, the length L1 of the side with the fastening part 5 in the left-right direction is longer than the length L2 of the other side without the fastening part 5 in the left-right direction (L1 > L2). Therefore, the user can easily identify the asymmetrical shape of the diaper 1 in its natural state relative to the center line CC in the left-right direction.

[0198] In addition, preferably, such as Figure 12 As shown, when the diaper 1 is viewed from the ventral waist 20 side in the front-back direction in the stretched state, the non-stretchable area N on the outer side of the absorbent core 11A in the left-right direction is asymmetrically arranged relative to the center line CC in the left-right direction.

[0199] Therefore, because the contractile force differs in the region closer to one side and the region closer to the center line CC in the left-right direction, the shape of the diaper 1's ventral waist portion 20 is easily asymmetrical relative to the center line CC when viewed from the ventral waist portion 20 side in the front-back direction. Users can easily identify this asymmetrical shape relative to the center line CC when viewing the diaper 1 from the ventral waist portion 20 side.

[0200] In addition, preferably, such as Figure 4 As shown, in the left-right direction, there is a one-sided telescopic region Sa between the joint 2a and the fixing part F1 that extends and retracts in the left-right direction. Furthermore, in the extended state, the length of the one-sided telescopic region Sa in the left-right direction is shorter than the length of the other-sided telescopic region Sb in the left-right direction.

[0201] Therefore, it is possible for a user who observes the diaper 1 from the side of the waist 20 to easily identify that the diaper 1 has an asymmetrical shape relative to the center line CC in the left and right directions. Furthermore, the elastic region Sa located between the joint 2a and the fixing part F1 can be used to give the fixing part 5 elasticity when the locking part 51 of the fixing part 5 is locked to the side of the waist 20. As a result, the operability of the fixing part 5 is improved, and it is easy to leave the user with the impression that the diaper 1 is easy to wear.

[0202] Furthermore, in diaper 1, the ends of the abdominal waist portion 20 and the dorsal waist portion 30 on one side in the left-right direction are joined by the joining portion 2a, and the base end of the fastening portion 5 is fixed to the abdominal waist portion 20 by the fixing portion F1. The front end of the fastening portion 5 has a locking portion 51 that can be detachably engaged with the non-skin side of the abdominal waist portion 20, and at least a portion of the fixing portion F1 that fixes the fastening portion 5 and the abdominal waist portion 20 is separated from the joining portion 2a in the left-right direction.

[0203] The attachment part 5 and the fixing part F1 are the parts to which force is applied when forming the waist opening, adjusting the size of the waist opening, and cutting off the ventral waist part 20. Therefore, by separating at least a portion of the fixing part F1 from the joint 2a, concerns can be reduced that the joint 2a may break or peel off from the ventral waist part 20 and the dorsal waist part 30 due to the force applied to the attachment part 5 and the fixing part F1 based on the movement of the attachment part 5.

[0204] Furthermore, even in a structure where the fixing part F1 is partially separated from the joining part 2a and the fixing part F1 partially overlaps the joining part 2a in the thickness direction (front-back direction), damage and peeling of the joining part 2a caused by the movement of the fixing part 5 can be reduced. However, it is more preferable that, as Figure 3As shown, in the left-right direction, the fixing part F1 is completely separated from the joint part 2a. This further reduces concerns that the joint of the joint part 2a may break or peel off due to the movement of the fixing part 5.

[0205] Regarding the fixing part 5, preferably, in the left-right direction, the fixing part F1 is located on the other side than the joining part 2a, and the engaging part 51 is located on the other side than the fixing part F1, such as... Figure 12 As shown, the fixing part 5 has a non-fixed part D on one side of the fixing part F1 and on the other side of the joining part 2a. The non-fixed part D is a so-called glue-free edge part that is not fixed to the abdominal waist part 20, and is a part that does not have adhesive, welding or other joining units.

[0206] like Figure 4 As shown, the non-fixed portion D is provided between the fixed portion F1 and the connecting portion 2a in the left-right direction. The portion between the fixed portion F1 and the connecting portion 2a in the left-right direction is the portion where force is applied during the movement and engagement of the fixing portion 5. Therefore, by covering at least a portion of this portion with the non-fixed portion D, concerns about damage to the portion between the fixed portion F1 and the connecting portion 2a can be reduced. However, not limited to the above, the non-fixed portion D can also be temporarily fixed by a plurality of discretely arranged welded portions. This prevents the non-fixed portion D from rolling up during manufacturing or distribution, and prevents the fixing portion 5 from separating from the waist portions 20 and 30 due to this rolling up.

[0207] Furthermore, the area between the joint 2a and the fixing part F1 in the left-right direction is a part where force is easily applied when the fixing part 5 is moved, and it is also a part that is prone to breakage. Therefore, by providing a one-sided telescopic region Sa that extends and retracts in the left-right direction between the joint 2a and the fixing part F1, the expansion and contraction of the one-sided telescopic region Sa can easily buffer the force generated by the movement of the fixing part 5, and reduce concerns about the part between the joint 2a and the fixing part F1 being broken.

[0208] Furthermore, preferably, in the left-right direction, there is a non-stretchable region Na (a portion of the non-stretchable region N) between the joint 2a and the fixing part F1, which does not stretch or extend in the left-right direction. This makes it easier to directly apply a force to the fixing part 5 to move it when moving it, facilitating engagement of the fixing part 5 and adjustment of the size of the waist opening based on the fixing part 5. More preferably, the non-stretchable region Na is configured to be adjacent to one side of the fixing part F1 in the left-right direction. By making the non-stretchable region Na adjacent to the fixing part F1, it is easier to directly apply a force to move the fixing part 5.

[0209] Furthermore, preferably, the base end of the fixing portion 5 is fixed to the waist portions 20 and 30 by the fixing portion F1, and at least a portion of the fixing portion F1 is also a cutting guide when at least a portion of the waist portions 20 and 30 is cut. Thus, a diaper 1 manufactured with a simplified manufacturing process can be provided, eliminating the need for manufacturing processes such as forming an easy-tear line to form the cutting guide.

[0210] Furthermore, the fixation of the ventral waist portion 20 and the fixing portion 5 at the fixing portion F1 can be achieved, for example, by using heat-based or ultrasonic welding, adhesives, or other methods. The skin-side waist portion 20, which has a tear-resistant seam, is prone to breakage due to its perforations and relatively few fibers. On the other hand, the welding portion is formed by melting and solidifying fibers, thus not reducing the total amount of fibers. Therefore, by using the fixing portion F1 based on the welding portion as a cutting guide, cutting can be performed when the intended cutting is desired. Furthermore, concerns can be reduced regarding the unintentional breakage of the ventral waist portion 20 at the cutting guide when cutting is not intended.

[0211] Preferably, when the diaper 1 is viewed from the ventral side of the waist section 20 in the front-back direction, in the adjacent area adjacent to the fixing part F1 from the front end side of the fixing part 5, the minimum weight per unit area of ​​the fixing part 5 is greater than the maximum weight per unit area of ​​the waist sections 20 and 30.

[0212] Therefore, when the fixing part 5 and the ventral waist part 20 are pulled outwards in the left and right directions respectively, the tearing force is concentrated on the fixing part F1. At the end CE on the other side of the fixing part F1 in the left and right directions, the ventral waist part 20, which has a smaller weight per unit area, is easily cut off by tearing. The fixing part 5, which has a larger weight per unit area, is more easily kept fixed to the fixing part F1.

[0213] Figure 15 This is an enlarged view of the fixed part F1 and the auxiliary fixed part F2.

[0214] The foremost end K in the cutting guide (fixed part F1) is the cutting guide starting point K. The cutting guide starting point K is the part where force is most easily concentrated when applying force to the ventral waist part 20 and the fixing part 5 to cut the ventral waist part 20 using the cutting guide, and it is also the part where cutting can be easily started initially. Furthermore, it is preferable that, as... Figure 8As shown, the cutting guide has inclined portions fa1 and fb1 that slope from the foremost end K toward the base end and are inclined in the vertical direction. This allows the force exerted by the wearer when pulling the abdominal waist section 20 and the fastening portion 5 to be concentrated first at the cutting guide starting point K, and this force can be easily transmitted from the cutting guide starting point K to the inclined portions fa1 and fb1. Therefore, it is easy to cut the abdominal waist section 20 into a shape along the cutting guide.

[0215] In addition, preferably, such as Figure 8 As shown, the cutting guide has an upper inclined portion fa1 and a lower inclined portion fb1. The upper inclined portion fa1 is an inclined portion that slopes upward from the foremost end K (cutting guide starting point) and is inclined towards the base end side, while the lower inclined portion fb1 is an inclined portion that slopes downward from the foremost end K (cutting guide starting point) and is inclined towards the base end side. Therefore, it is easy to concentrate the force applied to the ventral waist portion 20 and the fixing portion 5 for cutting the ventral waist portion 20 using the cutting guide at the cutting guide starting point K, and it is easy to transmit the force concentrated at the cutting guide starting point K to the upper inclined portion fa1 and the lower inclined portion fb1, thereby facilitating the cutting of the ventral waist portion 20.

[0216] Furthermore, more preferably, the angle θ at the base end in the left-right direction of the angle formed by the upper inclined portion fa1 and the lower inclined portion fb1 is an obtuse angle (an angle greater than 90 degrees and less than 180 degrees). This facilitates the transmission of the force applied from the cutting guide point K to the upper inclined portion fa1 and the lower inclined portion fb1, making the cutting of the ventral waist portion 20 easier, and compared to the case where θ is an acute angle, the length of the cutting guide portion (fixed portion F1) in the left-right direction can be shortened.

[0217] Preferably, the two ends of the ventral waist portion 20 and the dorsal waist portion 30 are joined by joints 2a and 2b, respectively. The waist portions 20 and 30 have cutting guides for cutting at least partially, and the cutting guides are located at positions different from the joints 2a and 2b provided at the two ends in the left-right direction. The cutting guides are molten portions formed by melting at least partially of the waist portions 20 and 30. Thus, when an operation is performed with the intention of cutting, cutting is possible. On the other hand, concerns that the ventral waist portion 20 may break at the cutting guides without the wearer's or other intention to cut is reduced.

[0218] Preferably, the diaper 1 has auxiliary melting sections F2 that are different from the melting section F1. In the plurality of auxiliary melting sections F2, at least a portion of the ventral waist section 20 is melted, and they are arranged intermittently in the vertical direction. Preferably, the plurality of auxiliary melting sections F2 are provided in the direction along the waist opening at a position closer to the base end of the fixing section 5 than the cutting guide section (fixing section F1).

[0219] Therefore, by using the fixing part F1 as a cutting guide to guide the cutting of the abdominal waist part 20 and having multiple auxiliary melting parts F2, the following concern can be reduced: the abdominal waist part 20 is cut off at a position opposite to the wearer's intention, that is, at the base end side of the fixing part 5, which is closer to the cutting guide.

[0220] Furthermore, it is preferable that at least partially, the length f2w in the left-right direction of the plurality of auxiliary melting portions F2 is longer than the length f2t in the up-down direction (f2w > f2t). By making the length f2w in the left-right direction of the auxiliary melting portion F2 longer than the length f2t in the up-down direction, compared with the case where the length f2w in the left-right direction of the auxiliary melting portion F2 is shorter than the length f2t in the up-down direction, the concern that the skin-side waist portion 20 may break off from the auxiliary melting portion F2 relative to the force applied to the ventral waist portion 20 from the left-right direction can be reduced.

[0221] The embodiments of the present invention have been described above. However, these embodiments are provided to facilitate understanding of the present invention and are not intended to limit the scope of the invention. Furthermore, it is self-evident that the present invention can be modified and improved without departing from its spirit, and the present invention includes its equivalents.

[0222] Explanation of reference numerals in the attached figures

[0223] 1. Diaper (disposable diapers, absorbent items); 2a, 2b. Joining part; 5. Fixing part; 10. Absorbent body; 11. Absorbent core; 11A. Absorbent insert; 12. Top piece; 13. Second piece; 14. Side piece; 15. Back piece; 16. Outer piece; 17. Leg opening elastic member; 18. Leak-proof elastic member; 20. Abdominal side waist (one side waist); 21. Skin side piece; 22. Non-skin side piece; 23. Elastic member; 25. Attachment 30. Waist section (other side waist section); 31. Skin side panel; 32. Non-skin side panel; 33. Telescopic component; 51. Locking part; 60. Marking part; P0. Predetermined position; 70. Tensile testing machine; 71. Chuck; BH. Waist opening; LH. Leg opening; F1. Fixing part; F2. Auxiliary fixing part; S. Telescopic area; Sa. Telescopic area on one side; Sb. Telescopic area on the other side; N. Non-telescopic area; W. Overlapping area.

Claims

1. An absorbent article having mutually orthogonal vertical, horizontal, and front-back directions, and having a waist section and a crotch section, wherein the waist section comprises a side waist section and a side waist section, characterized in that, The absorbent article has a fixing part. The front end of the fastening part has a locking part that can be detachably engaged with the non-skin side of the waist. The waist section is equipped with a telescopic component that extends and retracts in the left-right direction. With the fixing part engaging with at least one predetermined position of the separated waist part to form a waist opening, the fixing part is engaged with the engaging part. When the shrinkage rate is defined as the ratio obtained by dividing the length of the waist portion in the left-right direction by the length of the waist portion in the left-right direction when it is at its maximum elongation. At a predetermined shrinkage rate of 55% or more, at the center position of the fixed portion in the vertical direction, the length of the waist portion from the center in the horizontal direction to one side of the horizontal direction is the same as the length of the waist portion from the center in the horizontal direction to the other side of the horizontal direction. The elongation force acting on the waist section when it stretches along the left-right direction to a contraction rate that is 10% higher than 55% is divided by the elongation force acting on the waist section when it stretches along the left-right direction to the contraction rate, resulting in a value of 1.8 or higher.

2. The absorbent article according to claim 1, characterized in that, The value obtained by dividing the contraction force acting on the waist section when it contracts to the specified contraction rate in the left-right direction by the elongation force acting on the waist section when it stretches to the specified contraction rate in the left-right direction is 0.8 or less.

3. The absorbent article according to claim 1 or 2, characterized in that, The waist section has: The engaging portion, which can engage with the fixing portion; and In the non-stretchable region, there is no stretchable member from the upper end to the lower end of the waist section. The engaging portion has a portion that overlaps with the non-stretchable region in the left-right direction.

4. The absorbent article according to claim 3, characterized in that, In the left-right direction, the entire area of ​​the engaged portion overlaps with the non-stretchable area.

5. The absorbent article according to claim 1 or 2, characterized in that, The absorbent article has an absorbent body. The waist section has a non-telescopic region on its front side in the front-rear direction, from the upper end to the lower end of the waist section, where the telescopic member is not present. The non-stretchable region is located at the center of the absorber in the left-right direction across the front side. When the fixing part is engaged with the locking part at at least one of the separated waist parts and is in an extended state, the length of the non-telescopic region in the left-right direction is more than 20% and less than 50% of the total length of the left-right direction of the waist part on one side and the waist part on the other side.

6. The absorbent article according to claim 1 or 2, characterized in that, The predetermined position is located on the front side of the waist in the front-back direction. Regarding the telescopic region of the front waist section, compared to the telescopic region of the rear waist section, The force used to extend the area of ​​unit width in the vertical direction by a predetermined length in the horizontal direction is relatively large.

7. The absorbent article according to claim 1 or 2, characterized in that, The absorbent article has an absorbent body. The base end of the fixed part is fixed to the waist part by the fixing part. The region from the center of the absorbent body to the fixed part in the left-right direction of the waist section is a non-telescopic region from the top to the bottom where the telescopic member does not exist.

8. The absorbent article according to claim 1 or 2, characterized in that, The base end of the fixed part is fixed to the waist part by the fixing part. The waist portion has a first portion located on the outer side in the left-right direction compared to the fixing portion, and a second portion for engaging with the engaging portion of the fixing portion. The absorbent article has markings for engaging the fixation portion in such a way that the center line bisecting the first portion along the vertical direction and the center line bisecting the second portion along the vertical direction are located on a straight line along the horizontal direction.

9. The absorbent article according to claim 8, characterized in that, The marking portion is shaped along the outer contour of the fixing portion.

10. The absorbent article according to claim 1 or 2, characterized in that, The absorbent article has a marking portion for engaging the fixing portion at the predetermined position.

11. The absorbent article according to claim 1 or 2, characterized in that, The absorbent article has an absorbent body. At a location one side closer to the center in the left-right direction of the absorbent, the base end of the fixing part is fixed to the waist part by a fixing part, and at least one marking part is provided for engaging the fixing part.

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