Underpants-type absorbent article

Abstract

Provided is an underpants-type absorbent article. In order to easily tear along a side seal extending in the longitudinal direction and stabilize the step for forming the side seal in an underpants-type absorbent article, an underpants-type disposable diaper (100) has a side seal (50) formed by joining a side part (11) of an abdomen-side part (10) and a side part (31) of a back-side part (30), and has a waist opening (P1) and two leg openings (P2) formed therein. In the side seal (50), at least two rows of a plurality of seal parts (51a, 52a) arranged in the longitudinal direction (H) are formed in the width direction (W), the seal parts (51a) of an inner first row (51) and the seal parts (52a) of an inner second row (52) are alternately arranged in the longitudinal direction (H), the interval (Dy) along the longitudinal direction (H) between the seal parts (51a, 52a) is set to be 0.8-1.2 [mm], and the seal parts (51a, 52a) are formed such that the longitudinal dimension (Y) is longer than the lateral dimension (X).

Description

Technical Field

[0001] The present invention relates to pant-type absorbent articles. Background Art

[0002] When taking off (removing) the worn underpants type disposable diaper, the joining area (side seal) extending longitudinally at both sides of the waist of the diaper is torn. The side seal is generally formed with a plurality of joining parts (sealing parts) arranged longitudinally.

[0003] When tearing the side seal, the side seal is torn from the waist opening toward the leg opening, but the longitudinal tearing along the side seal is sometimes not smooth, and the side seal is torn in the circumferential direction of the waist, that is, in the transverse direction of the width of the diaper. Moreover, if the diaper is torn in the transverse direction, it is difficult to remove the diaper smoothly.

[0004] Therefore, in order to facilitate sealing along the longitudinal tear side, a pull-on disposable diaper with improved shapes and arrangement patterns of seal portions has been proposed (see, for example, Patent Documents 1 and 2).

[0005] Patent Document 1: Japanese Patent Application Publication No. 2015-096192

[0006] Patent Document 2: Japanese Patent Application Publication No. 2022-070524

[0007] However, if the interval between the sealing parts is too narrow, there is a possibility that adhesives such as hot melt adhesive melted by ultrasonic welding will seep out to the upper surface side, or an area where a collection of multiple sealing parts, i.e., a sealing pattern, does not exist in the lateral direction will be formed. As a result, the control in the process of forming the side seal will be unstable, and residues of the diaper material, i.e., the non-woven fabric, will adhere to the process equipment, making the operation of the sealing process unstable. Summary of the invention

[0008] The present invention has been completed in view of the above situation, and its purpose is to provide an underpants-type absorbent article that can easily tear along the side seal extending in the longitudinal direction when the side seal is torn from the waist opening toward the leg opening or when the side seal is torn from the leg opening toward the waist opening, and can stabilize the process of forming the side seal.

[0009] The present invention is an underpants-type absorbent article, which, in an unfolded state, is formed by a ventral portion, a crotch portion, and a dorsal portion being continuously connected in a prescribed direction in sequence, and has a joining area formed by overlapping and joining the side portions of the ventral portion and the side portions of the dorsal portion, forming a waist opening and two leg openings, wherein the joining area is formed with at least two rows of a plurality of joining portions arranged in a direction in which the joining area extends in a width direction, the plurality of joining portions arranged in the first inner row and the plurality of joining portions arranged in the second inner row being alternately arranged in the direction in which the joining area extends, and the inner first row The row is the row of the joining parts that are most inner in the width direction among the two rows of the joining parts, the inner second row is the row of the joining parts that are closest to the inner first row and are outer in the width direction, the interval Dy between the joining parts of the inner first row and the joining parts of the inner second row along the direction in which the joining area extends is set to 0.8 to 1.2 [mm], and the contour shape of the joining parts of the inner first row and the contour shape of the joining parts of the inner second row are formed so that the longitudinal dimension along the direction in which the joining area extends is longer than the lateral dimension along the direction orthogonal to the direction in which the joining area extends.

[0010] According to the underwear-type absorbent article involved in the present invention, when the side seal is torn from the waist opening toward the leg opening or when the side seal is torn from the leg opening toward the waist opening, it is easy to tear along the side seal extending in the longitudinal direction, and the process of forming the side seal is stabilized. BRIEF DESCRIPTION OF THE DRAWINGS

[0011] Figure 1 The diagram is a schematic diagram showing a disposable diaper in a state where it is worn by a wearer.

[0012] Figure 2 This is a schematic diagram showing a joining region (side seal) on the left side of the disposable diaper of Example 1.

[0013] Figure 3 It is a schematic diagram showing an example of a vertically long ellipse as the outline shape of the seal portion in the inner first row and the inner second row.

[0014] Figure 4 This is a schematic diagram showing how the rupture due to the tear load advances in the longitudinal direction H of the side seal 50 .

[0015] Figure 5 This is a schematic diagram showing the side seal on the left side of the disposable diaper of Example 2.

[0016] Figure 6 This is a schematic diagram showing the side seal on the left side of the disposable diaper of Example 3. DETAILED DESCRIPTION

[0017] Hereinafter, embodiments of the absorbent article according to the present invention will be described with reference to the drawings.

[0018] [Basic structure]

[0019] Figure 1 Schematic diagrams showing disposable diapers 100, 200, and 300 worn by a wearer M. Figure 2 1 is a schematic diagram showing the left side joining area (side seal) 50 of the disposable diaper 100 of Example 1. The disposable diaper 100 is an embodiment of the underpants absorbent article of the present invention. The disposable diaper 100 is formed by the ventral part 10, the crotch part 20, and the dorsal part 30 being connected in sequence in a predetermined direction (length direction) in the unfolded state.

[0020] Furthermore, the disposable diaper 100 has a joining region (side seal) 50 formed by joining the left side portion 11 of the belly portion 10 in the width direction (lateral direction) W and the left side portion 31 of the back portion 30 in the width direction W in the state of being expanded in the longitudinal direction, and has a joining region (side seal) 50 formed by joining the right side portion 12 of the belly portion 10 in the width direction W and the right side portion 32 of the back portion 30 in the width direction W. Thus, in the disposable diaper 100, the upper portion of the side seal 50 in the extension direction (height direction, longitudinal direction) H is formed with a waist opening P1 in which the belly portion 10 and the back portion 30 are connected in the circumferential direction R, and the lower portion in the height direction (longitudinal direction) H is formed with two leg openings P2, and the overall shape is a panty-like shape.

[0021] The two leg openings P2 are openings for allowing the legs of the wearer M to pass through when the wearer M wears the disposable diaper 100, and the waist opening P1 is an opening for allowing the waist of the wearer M to pass through. When the wearer wears the disposable diaper 100 in this way, the abdominal part 10 covers the lower abdomen of the wearer M, the back part 30 covers the buttocks of the wearer M, and the crotch part 20 covers the crotch of the wearer M.

[0022] Here, the side seal 50 is formed by ultrasonic welding with micro vibration while applying pressure in the stacking direction of the belly side 10 side and the back side 30 side while sandwiching an adhesive such as hot melt adhesive between the overlapping surfaces of the belly side 10 and the back side 30.

[0023] (Example 1)

[0024] In the disposable diaper 100 of the first embodiment, the side seals 50 are formed in the basic structure described above as described below.

[0025] That is, Figure 2As shown, the side seal 50 on the left side in the width direction W of the disposable diaper 100 has: a row 51 composed of a plurality of joining portions (sealing portions) 51a arranged along the direction (longitudinal direction H) in which the side seal 50 extends; a row 52 composed of a plurality of sealing portions 52a arranged along the longitudinal direction H; a row 53 composed of a plurality of sealing portions 53a arranged along the longitudinal direction H; a row 54 composed of a plurality of sealing portions 54a arranged along the longitudinal direction H; and a row 55 composed of a plurality of sealing portions 55a arranged along the longitudinal direction H.

[0026] The side seal 50 on the right side in the width direction W of the disposable diaper 100 and Figure 2 The side seal 50 on the left side shown is formed to be bilaterally symmetrical in the width direction W. Figure 2 In the figure, the left side in the width direction W is the inner side in the center direction of the disposable diaper 100 , and the right side in the width direction W is the outer side of the disposable diaper 100 .

[0027] Here, the row 51 is the row formed on the innermost side in the width direction W in the side seal 50 on the left side, and is hereinafter referred to as the inner first row 51. In addition, the row 52 is the row formed on the outer side in the width direction W closest to the inner first row 51, and is hereinafter referred to as the inner second row 52. As described later, the inner first row 51 and the inner second row 52 form a guide portion that guides rupture by a tear load.

[0028] In addition, row 53 is the row formed on the outside of the width direction W closest to the inner second row 52, ​​hereinafter referred to as the inner third row 53, row 54 is the row formed on the outside of the width direction W closest to the inner third row 53, hereinafter referred to as the inner fourth row 54, and row 55 is the row formed on the outside of the width direction W closest to the inner fourth row 54, hereinafter referred to as the inner fifth row 55.

[0029] The plurality of seals 51a arranged in the inner first row 51 and the plurality of seals 52a arranged in the inner second row 52 of the disposable diaper 100 are alternately arranged in the longitudinal direction H, and the gap Dy between the alternately arranged seals 51a and 52a is set to 0.8 to 1.2 [mm].

[0030] In addition, the contour shape of the seal portion 51a of the inner first row 51 and the contour shape of the seal portion 52a of the inner second row 52 of the disposable diaper 100 are formed so that the dimension (longitudinal dimension) Y along the longitudinal direction H is longer than the dimension (lateral dimension) X along the width direction W (lateral direction) orthogonal to the longitudinal direction H. Specifically, Figure 2 As shown, the contour shape of the sealing portion 51a and the sealing portion 52a is formed into a vertically long diamond shape in which the longitudinal dimension Y is longer than the lateral dimension X.

[0031] Figure 3Schematic diagram showing an example of a longitudinally long ellipse as the contour shape of the sealing portion 51a and the sealing portion 52a. The contour shape of the sealing portion 51a and the sealing portion 52a of the disposable diaper 100 can be any shape as long as it is long (lateral dimension X < longitudinal dimension Y), and is not limited to a longitudinally long rhombus. Specifically, the contour shape of the sealing portion 51a and the sealing portion 52a of the disposable diaper 100 can also be as follows: Figure 3 The shape shown is an elongated oval, but other elongated shapes are also possible.

[0032] In addition, if Figure 2 As shown in the figure, the seal portions 53a of the inner third row 53, the seal portions 54a of the inner fourth row 54, and the seal portions 55a of the inner fifth row 55 of the disposable diaper 100 are formed in a longitudinally long elliptical shape, but the seal portions on the outer side in the width direction W other than the seal portions 51a of the inner first row 51 and the seal portions 52a of the inner second row 52 may not be in a longitudinally long shape, and may be in a shape other than an elliptical shape. In addition, the disposable diaper 100 may not have the inner third row 53, the inner fourth row 54, and the inner fifth row 55 on the outer side in the width direction W other than the seal portions 51a of the inner first row 51 and the seal portions 52a of the inner second row 52, ​​or may only have at least one of the inner third row 53, the inner fourth row 54, and the inner fifth row 55.

[0033] The seal portions 51a, 52a, 53a, 54a, and 55a are not only joined at the contour portions of the longitudinal contour shapes, but also are entirely joined at the inner ranges surrounded by the contour shapes.

[0034] In the disposable diaper 100, the longitudinal dimension Y of the seal portion 51a of the inner first row 51 is set to be larger than the interval Dy between the seal portion 51a and the seal portion 52a (Dy<Y).

[0035] In the disposable diaper 100, the inner second row of seals 52a are arranged on the extension line 60 of the tear line 51p of the seals 51a of the inner first row 51. Here, the tear line 51p is a straight line connecting the inner end point of the seal 51a in the transverse dimension X and the lower end point in the longitudinal dimension Y. Figure 2 In the diamond-shaped sealing portion 51 a shown, the contour line located at the lower inner side in the width direction W of the diamond contour shape is consistent.

[0036] In addition, the contour shape of the sealing portion 51a is Figure 3In the case of the longitudinally long oval shown, the tear line 51p is a straight line connecting the end point of the sealing portion 51a on the inner side of the transverse dimension X and the end point on the lower side of the longitudinal dimension Y. When the contour shape of the sealing portion 51a is another shape, the tear line 51p is the same as in the case of the longitudinally long oval.

[0037] Furthermore, the disposable diaper 100 is set so that the distance d21 from the seal portion 52a of the inner second row 52 to the seal portion 51a of the inner first row 51 is shorter than the distance d23 from the seal portion 52a of the inner second row 52 to the seal portion 53a of the inner third row 53 (d21<d23).

[0038] When the wearer M takes off the disposable diaper 100 that the wearer M has been wearing by himself or when an assistant takes off the disposable diaper 100 that the wearer M has been wearing, the wearer M or the assistant holds the ventral part 10 near the side seal 50 at the waist opening P1 with one hand and holds the dorsal part 30 near the side seal 50 at the waist opening P1 with the other hand, and moves the two hands away from each other, thereby tearing the side seal 50 from the waist opening P1 toward the leg opening P2.

[0039] The tearing load first acts on the uppermost seal portion 51a of the first inner row 51 of the side seal 50. Then, the tearing load breaks the ventral portion 10 or the dorsal portion 30 along the contour line located inside the width direction of the contour shape of the seal portion 51a. Here, whether the ventral portion 10 or the dorsal portion 30 breaks varies depending on the sealing state of the seal portion 51a, the method of applying the load during tearing, and the like.

[0040] Figure 4 Schematic diagram showing the state in which the tearing load causes the fracture to advance in the longitudinal direction H of the side seal 50. Figure 4 As shown by the dotted line with short intervals in the figure, the tearing load causes the ventral part 10 or the dorsal part 30 to break along the inner contour line of the uppermost seal portion 51a of the inner first row 51 in the width direction W, and reaches the seal portion 51a formed below the seal portion 51a of the inner second row 52. Then, the tearing load is turned back to the inner side in the width direction W at the seal portion 52a, and is transmitted to the seal portion 51a of the second layer formed below the seal portion 52a of the inner first row 51.

[0041] Next, from the upper side toward the lower side, the tearing load is alternately transmitted to the sealing portion 51a of the inner first row 51 and the sealing portion 52a of the inner second row 52, ​​as shown in FIG. Figure 4As shown by the short dashed lines at short intervals, between the sealing portions 51a of the inner first row 51 and the sealing portions 52a of the inner second row 52 in the side seal 50, the break advances from the upper side toward the lower side, and finally reaches the leg opening P2 on the left side. The left side seal 50 breaks along the longitudinal direction H, and the ventral part 10 and the dorsal part 30 are separated.

[0042] Regarding the right side seal 50, it breaks in the same way as the break of the left side seal 50 described above, and the ventral part 10 and the dorsal part 30 are separated.

[0043] As described above, the disposable diaper 100 of the pant type in the first embodiment is formed with at least these two rows, the inner first row 51 and the inner second row 52, on both sides in the width direction W, as rows of a plurality of sealing portions arranged discontinuously along the longitudinal direction H. The plurality of sealing portions 51a arranged in the inner first row 51 and the plurality of sealing portions 52a arranged in the inner second row 52 are respectively formed to be alternately arranged in the longitudinal direction H.

[0044] Thereby, the disposable diaper 100 can transfer the break generated from the periphery of the sealing portion 51a of the inner first row 51 to the sealing portion 52a of the inner second row 52, and can easily tear the side seal 50 along the longitudinal direction H, and is not easily broken in the width direction W.

[0045] In addition, regarding the shape of the sealing portion 51a of the inner first row 51 and the shape of the sealing portion 52a of the inner second row 52 for transmitting the tearing load of the disposable diaper 100, the longitudinal dimension Y is longer than the transverse dimension X (transverse dimension X < longitudinal dimension Y). Therefore, regarding the break along the contour of each of the sealing portions 51a, 52a, this break is more likely to occur in the longitudinal direction H than in the width direction W, and the tearing load is easily transmitted in the longitudinal direction H, and the side seal 50 can be easily torn along the longitudinal direction H.

[0046] In addition, the interval Dy along the longitudinal direction H between the sealing portions 51a of the inner first row 51 and the sealing portions 52a of the inner second row 52, which are alternately arranged in the longitudinal direction H of the disposable diaper 100, is set to 0.8 to 1.2 [mm]. Thereby, the disposable diaper 100 can easily transmit the tearing load in the longitudinal direction H, and can prevent the adhesive from leaking from the sealing portions 51a, 52a to the sonic equipment (Japanese: ソニック設備) in the manufacturing process of forming the sealing portions 51a, 52a, thereby preventing dirt from adhering to the sonic equipment, and can prevent the operation of the sonic equipment from becoming unstable due to the adhesion of dirt, thereby stabilizing the process of forming the side seal 50.

[0047] In addition, the disposable diaper 100 is set so that the longitudinal dimension Y of the sealing portion 51a of the inner first column 51 is larger than the interval Dy of the gap between the sealing portion 51a of the inner first column 51 and the sealing portion 52a of the inner second column 52 (Dy<Y), so it is easy to transmit the tearing load from the sealing portion 51a of the inner first column 51 to the sealing portion 52a of the inner second column 52.

[0048] In addition, the disposable diaper 100 can also be set so that the longitudinal dimension Y of the sealing portion 51a of the inner first column 51 is equal to the interval Dy between the sealing portion 51a and the sealing portion 52a (Dy=Y). In this case, it is also easy to transfer the tearing load from the sealing portion 51a of the inner first column 51 to the sealing portion 52a of the inner second column 52.

[0049] It is a preferred form to set the longitudinal dimension Y of the sealing portion 51a of the inner first column 51 to be greater than or equal to the interval Dy (Dy≤Y) between the sealing portion 51a of the inner first column 51 and the sealing portion 52a of the inner second column 52, but it is not a necessary component of the underwear-type absorbent article involved in the present invention.

[0050] In addition, the disposable diaper 100 has the seal portion 52a of the inner second column 52 arranged on the extension line 60 of the tear line 51p of the seal portion 51a of the inner first column 51, so it is easy to transfer the tearing load from the seal portion 51a of the inner first column 51 to the seal portion 52a of the inner second column 52.

[0051] It is a preferred embodiment that the seal portions 52a of the inner second row 52 are arranged on the extension line 60 of the tear line 51p of the seal portions 51a of the inner first row 51, but this is not an essential component of the underpants-type absorbent article of the present invention.

[0052] In addition, the distance d21 from the seal portion 52a of the inner second column 52 to the seal portion 51a of the inner first column 51 of the disposable diaper 100 is shorter than the distance d23 from the seal portion 52a of the inner second column 52 to the seal portion 53a of the inner third column 53. Therefore, for a break that advances from the seal portion 51a of the inner first column 51 to the seal portion 52a of the inner second column 52, the break can more easily advance to the seal portion 51a of the inner first column 51 than from the seal portion 52a of the inner second column 52 to the seal portion 53a of the inner third column 53.

[0053] In addition, it is a preferred form that the distance d21 from the sealing portion 52a of the inner second column 52 to the sealing portion 51a of the inner first column 51 is shorter than the distance d23 from the sealing portion 52a of the inner second column 52 to the sealing portion 53a of the inner third column 53, but it is not a necessary component of the underwear-type absorbent article involved in the present invention.

[0054] (Example 2)

[0055] Figure 5 1 is a schematic diagram showing the left side seal 50 of the underpants-type disposable diaper 200 of Example 2. The basic structure of the underpants-type disposable diaper 200 of Example 2 is the same as that of the disposable diaper 100 of Example 1 described above.

[0056] Specifically, if Figure 5 As shown, the side seal 50 on the left side in the width direction W of the disposable diaper 200 is formed with an inner first row 51, an inner second row 52, ​​an inner third row 53, an inner fourth row 54 and an inner fifth row 55 in order from the inner side in the width direction W.

[0057] Moreover, the disposable diaper 200 has a plurality of sealing portions 51a arranged along the longitudinal direction H in the first inner column 51, a plurality of sealing portions 52a arranged along the longitudinal direction H in the second inner column 52, a plurality of sealing portions 53a arranged along the longitudinal direction H in the third inner column 53, a plurality of sealing portions 54a arranged along the longitudinal direction H in the fourth inner column 54, and a plurality of sealing portions 55a arranged along the longitudinal direction H in the fifth inner column 55.

[0058] In the disposable diaper 200, the plurality of seals 51a arranged in the inner first row 51 and the plurality of seals 52a arranged in the inner second row 52 are arranged alternately in the longitudinal direction H, and the gap Dy between the alternately arranged seals 51a and 52a is set to 0.8 to 1.2 [mm].

[0059] In addition, the contour shape of the seal portion 51a of the inner first row 51 and the contour shape of the seal portion 52a of the inner second row 52 of the disposable diaper 200 are formed so that the dimension (longitudinal dimension) Y along the longitudinal direction H is longer than the dimension (lateral dimension) X along the width direction W (lateral direction) orthogonal to the longitudinal direction. Specifically, the contour shape of the seal portion 51a and the seal portion 52a is formed in a lateral fan shape.

[0060] For the transverse fan shape of the sealing portion 51a, 52a, specifically, the line toward the inner side of the width direction W is an arc, and the line toward the outer side of the width direction is formed as a straight line inclined in a manner of descending toward the lower side of the longitudinal direction H as it approaches the outer side of the width direction W from the upper end of the arc, and a straight line inclined in a manner of rising toward the upper side of the longitudinal direction H as it approaches the outer side of the width direction W from the lower end of the arc, intersecting at an angle of 90 degrees.

[0061] In the disposable diaper 200, the sealed portions 53a of the inner third row 53, the sealed portions 54a of the inner fourth row 54, and the sealed portions 55a of the inner fifth row 55 are formed in a circular shape, but these inner third row 53, inner fourth row 54, and inner fifth row 55 may be omitted.

[0062] In addition, in the disposable diaper 200, the dimension between the inner first column 51 and the inner second column 52 is set so that at least one seal portion 51a, 52a is formed in any longitudinal direction H within the entire range L0 in the width direction W from the seal portion 51a of the inner first column 51 to the seal portion 52a of the inner second column 52.

[0063] That is, in the disposable diaper 200, the seal portions 51a and 52a are arranged so that Figure 5 In the entire range L0 in the width direction W from the sealing portion 51a of the inner first column 51 to the sealing portion 52a of the inner second column 52, when the straight line L extending along the longitudinal direction H is assumed to move, within the entire range L0, the straight line L crosses at least one of the sealing portion 51a and the sealing portion 52a.

[0064] Similar to the disposable diaper 100 of Example 1, the underwear-type disposable diaper 200 of Example 2 constructed in this way can transfer the rupture generated at the periphery of the sealing portion 51a of the inner first column 51 to the sealing portion 52a of the inner second column 52, and can easily tear the side seal 50 along the longitudinal direction H without being easily broken in the width direction W.

[0065] In addition, with respect to the shapes of the sealing portions 51a of the inner first column 51 and the sealing portions 52a of the inner second column 52 of the disposable diaper 200 that transmit the tearing load, the longitudinal dimension Y is longer than the transverse dimension X (transverse dimension X<longitudinal dimension Y). Therefore, with respect to the rupture along the contour of each sealing portion 51a, 52a, the rupture is more likely to occur in the longitudinal direction H than in the width direction W, and the tearing load is easily transmitted in the longitudinal direction H, so that the side seal 50 can be easily torn along the longitudinal direction H.

[0066] In addition, the interval Dy along the longitudinal direction H between the seal portions 51a of the inner first row 51 and the seal portions 52a of the inner second row 52 of the disposable diaper 200, which are alternately arranged in the longitudinal direction H, is set to 0.8 to 1.2 [mm]. As a result, the disposable diaper 200 can easily transmit the tear load in the longitudinal direction H, and can prevent the adhesive from leaking from the seal portions 51a, 52a to the sonic wave device in the manufacturing process of forming the seal portions 51a, 52a, thereby preventing dirt from adhering to the sonic wave device, and preventing the operation of the sonic wave device from becoming unstable due to the adhesion of dirt, thereby stabilizing the process of forming the side seal 50.

[0067] In addition, in the disposable diaper 200, the dimension between the inner first column 51 and the inner second column 52 is set so that at least one sealing portion 51a, 52a is formed in any longitudinal direction H within the entire range L0 in the width direction W from the sealing portion 51a of the inner first column 51 to the sealing portion 52a of the inner second column 52.

[0068] Here, in the case of a side seal of a disposable diaper having a portion where no seal portion exists in the entire range L0 in the width direction W from the seal portion 51a of the inner first column 51 to the seal portion 52a of the inner second column 52, when the disposable diaper that is relatively formed and moved in the width direction W is pressurized by the horn (Japanese: ホーン) of an ultrasonic welding device extending along the longitudinal direction H, it is necessary to carefully perform control such as weakening the pressure in the portion where no seal portion exists in the entire longitudinal direction H, which may become a major cause of unstable operation of the ultrasonic wave device.

[0069] In contrast, the disposable diaper 200 of Example 2 has no portion without a seal portion in the entire range L0 in the width direction W, so there is no factor that causes the operation of the sonic wave device to be unstable, and the sonic wave device can be operated stably.

[0070] It is a preferred embodiment that there is no portion without a seal portion in the entire longitudinal direction H at all positions in the entire range L0 in the width direction W, but it is not an essential component of the underpants-type absorbent article according to the present invention.

[0071] In addition, the seal portion 51a of the disposable diaper 200 is formed into a transverse fan shape with the inner line in the width direction W being an arc, so the tearing load is easily transmitted from the seal portion 51a of the inner first row 51 to the seal portion 52a of the inner second row 52.

[0072] In the disposable diaper 200 , the seal portion 51 a may also be provided with a crescent shape that becomes convex toward the inside in the width direction W, instead of the lateral fan shape in which the line toward the inside in the width direction W is an arc.

[0073] (Example 3)

[0074] Figure 6 1 is a schematic diagram showing the side seal 50 on the left side of the underpants-type disposable diaper 300 of Embodiment 3. The basic structure of the underpants-type disposable diaper 300 of Embodiment 3 is the same as that of the disposable diaper 100 of Embodiment 1 described above.

[0075] Specifically, if Figure 6As shown, the side seal 50 on the left side in the width direction W of the disposable diaper 300 is formed with an inner first row 51, an inner second row 52, ​​an inner third row 53, an inner fourth row 54 and an inner fifth row 55 in order from the inner side in the width direction W.

[0076] Moreover, the disposable diaper 300 has a plurality of sealing portions 51a arranged along the longitudinal direction H in the first inner column 51, a plurality of sealing portions 52a arranged along the longitudinal direction H in the second inner column 52, a plurality of sealing portions 53a arranged along the longitudinal direction H in the third inner column 53, a plurality of sealing portions 54a arranged along the longitudinal direction H in the fourth inner column 54, and a plurality of sealing portions 55a arranged along the longitudinal direction H in the fifth inner column 55.

[0077] The plurality of seals 51a arranged in the inner first row 51 and the plurality of seals 52a arranged in the inner second row 52 of the disposable diaper 300 are alternately arranged in the longitudinal direction H, and the gap Dy between the alternately arranged seals 51a and 52a is set to 0.8 to 1.2 [mm].

[0078] In addition, the contour shape of the seal portion 51a of the inner first row 51 and the contour shape of the seal portion 52a of the inner second row 52 of the disposable diaper 300 are formed so that the dimension (longitudinal dimension) Y along the longitudinal direction H is longer than the dimension (lateral dimension) X along the width direction W (lateral direction) perpendicular to the longitudinal direction. Specifically, the contour shape of the seal portion 51a and the seal portion 52a is formed into a longitudinally long elliptical shape.

[0079] Moreover, the seal parts 53a of the inner third row 53, the seal parts 54a of the inner fourth row 54, and the seal parts 55a of the inner fifth row 55 of the disposable diaper 300 are formed in a circular shape.

[0080] Moreover, if Figure 6 As shown, a part of the seal portions 52a of the plurality of seal portions 52a of the inner second row 52 of the disposable diaper 300 and the seal portions 54a formed at the same position in the longitudinal direction H of the inner fourth row 54 are connected by a horizontally long strip-shaped seal portion 56 to form a whole. Similarly, a part of the seal portions 53a of the plurality of seal portions 53a of the inner third row 53 of the disposable diaper 300 and the seal portions 55a formed at the same position in the longitudinal direction H of the inner fifth row 55 are connected by a horizontally long strip-shaped seal portion 56 to form a whole.

[0081] In addition, a part of the plurality of seals 51a in the inner first row 51 of the disposable diaper 300 may be connected to the seals 53a formed at the same position in the longitudinal direction H in the inner third row 53 by a horizontally long strip-shaped seal 56 to form an integral body.

[0082] Similar to the disposable diaper 100 of Example 1, the underwear-type disposable diaper 300 of Example 3 constructed in this way can transfer the rupture generated at the periphery of the sealing portion 51a of the inner first column 51 to the sealing portion 52a of the inner second column 52, and can easily tear the side seal 50 along the longitudinal direction H without being easily broken in the width direction W.

[0083] In addition, with respect to the shapes of the sealing portions 51a of the inner first column 51 and the sealing portions 52a of the inner second column 52 of the disposable diaper 300 that transmit the tearing load, the longitudinal dimension Y is longer than the transverse dimension X (transverse dimension X<longitudinal dimension Y). Therefore, with respect to the breaking along the contour of each sealing portion 51a, 52a, the breaking is more likely to occur in the longitudinal direction H than in the width direction W, and the tearing load is easily transmitted in the longitudinal direction H, so that the side seal 50 can be easily torn along the longitudinal direction H.

[0084] In addition, the interval Dy along the longitudinal direction H between the seal portions 51a of the inner first row 51 and the seal portions 52a of the inner second row 52 of the disposable diaper 300, which are alternately arranged in the longitudinal direction H, is set to 0.8 to 1.2 [mm]. As a result, the disposable diaper 300 can easily transmit the tear load in the longitudinal direction H, and can prevent the adhesive from leaking from the seal portions 51a, 52a to the sonic wave device in the manufacturing process of forming the seal portions 51a, 52a, thereby preventing dirt from adhering to the sonic wave device, and preventing the operation of the sonic wave device from becoming unstable due to the adhesion of dirt, thereby stabilizing the process of forming the side seal 50.

[0085] Furthermore, a portion of the multiple seals 52a of the inner second column 52 of the disposable diaper 300 is integrated with the seals 54a of the inner fourth column 54, and a portion of the multiple seals 53a of the inner third column 53 is integrated with the seals 55a of the inner fifth column 55.

[0086] Therefore, the disposable diaper 300 does not have a portion in the entire range in the width direction W from the seal portion 52a of the second inner column 52 to the seal portion 54a of the fourth inner column 54 where the seal portion is not present in the entire longitudinal direction H. In addition, the disposable diaper 300 does not have a portion in the entire range in the width direction W from the seal portion 53a of the third inner column 53 to the seal portion 55a of the fifth inner column 55 where the seal portion is not present in the entire longitudinal direction H. Therefore, for the same reason as the disposable diaper 200 of Example 2, there is no main cause that makes the operation of the acoustic wave device unstable, and the acoustic wave device can be operated stably.

[0087] Furthermore, in the disposable diaper 300, when a portion of the seal portion 51a of the inner first column 51 and the seal portion 53a of the inner third column 53 are formed as one piece, there is no portion in the entire longitudinal direction H where the seal portion does not exist at any position in the entire range in the width direction W from the seal portion 51a of the inner first column 51 to the seal portion 53a of the inner third column 53, so that the ultrasonic device can be stably operated in the entire area of ​​the side seal 50.

[0088] In the disposable diaper 300, the seal portions at the same position in the longitudinal direction H are connected to each other and the seal portions are formed larger, so that the bonding strength of the portions can be increased.

[0089] In the disposable diaper 300, the seal portion 52a formed integrally with the seal portion 54a of the inner fourth row 54 among the plurality of seal portions 52a of the inner second row 52 may be selected according to the number of overlapping components of the ventral portion 10 and the dorsal portion 30. That is, the joint portion of the disposable diaper 300 having a larger number of overlapping components joined by the seal portion has a stronger joining strength than the joint portion having a smaller number of overlapping components joined by the seal portion.

[0090] Furthermore, a strong tearing load is required to tear the portion with high bonding strength and break the portion with high bonding strength in the disposable diaper 300. Therefore, for the bonding portion with a large number of overlapping sheets of the disposable diaper 300, it is preferred to reduce the bonding strength by making the bonding area smaller than that of the bonding portion with a small number of overlapping sheets, thereby achieving easier tearing.

[0091] Therefore, on the one hand, for the portion of the disposable diaper 300 where the number of overlapping sheets is large and joined by the sealing portion, the sealing portions are not connected to each other in order to reduce the joining area compared with the portion where the number of overlapping sheets is small. On the other hand, for the portion where the number of overlapping sheets is small and joined by the sealing portion, even if the joining area is increased compared with the portion where the number of overlapping sheets is large, the above-mentioned problem is less, so it is preferably selected as the portion where the sealing portions are connected to each other.

[0092] In addition, although connecting the seal parts to each other is a preferred embodiment, it is not an essential component of the pull-on absorbent article according to the present invention.

[0093] For the disposable diapers 100, 200, 300 of the above-mentioned embodiments 1, 2, and 3, an example is described as that when the side seal 50 is torn from the waist opening P1 toward the leg opening P2, it is easy to tear along the side seal 50 extending in the longitudinal direction H, and the process of forming the side seal 50 is stabilized. However, even when the side seal 50 is torn from the leg opening P2 toward the waist opening P1, it is easy to tear along the side seal 50 extending in the longitudinal direction H, and the process of forming the side seal 50 can be stabilized.

[0094] This application claims priority based on patent application No. 2023-012323 filed with the Japan Patent Office on January 30, 2023, the entire disclosure of which is fully incorporated into this specification by reference.

Claims

1. An underpants absorbent article, which, in an unfolded state, is formed by a ventral portion, a crotch portion, and a dorsal portion being connected in sequence in a predetermined direction, has a joining area formed by overlapping and joining the side portion of the ventral portion and the side portion of the dorsal portion, and has a waist opening and two leg openings, characterized in that: The joining region is formed with at least two rows of a plurality of joining portions arranged in a direction in which the joining region extends in the width direction. The plurality of joining portions arranged in the inner first column and the plurality of joining portions arranged in the inner second column are alternately arranged in the direction in which the joining area extends, the inner first column is the column of joining portions that is most inner in the width direction of the two columns of joining portions, and the inner second column is the column of joining portions that is closest to the inner first column and is most outer in the width direction. The interval between the bonding parts of the first inner row and the bonding parts of the second inner row along the direction in which the bonding area extends is set to 0.8 to 1.2, in units of mm. The contour shapes of the joining portions in the first inner row and the second inner row are formed such that the longitudinal dimension along the direction in which the joining region extends is longer than the lateral dimension along the direction orthogonal to the direction in which the joining region extends.

2. The underpants-type absorbent article according to claim 1, characterized in that The longitudinal dimension of the engagement portions of the inner first row is greater than or equal to the spacing.

3. The underpants-type absorbent article according to claim 1, characterized in that: The joining portions in the inner second row are arranged on the extension lines of the tear lines of the joining portions in the inner first row.

4. The underpants-type absorbent article according to claim 1, characterized in that: The distance from the joining portion of the inner second column to the joining portion of the inner first column is shorter than the distance from the joining portion of the inner second column to the joining portion of the inner third column, and the inner third column is a column of joining portions closer to the outer side of the inner second column in the width direction.

5. The underpants-type absorbent article according to claim 1, characterized in that: The joining portion of at least one of the joining portions of the first inner column and the joining portions of the second inner column, and the joining portions at the same position in the direction in which the joining area extends in other columns of the joining portions different from the first inner column or in other columns of the joining portions different from the second inner column are connected by a band-shaped joining portion to form a whole.

6. The underpants-type absorbent article according to any one of claims 1 to 5, characterized in that: In the entire range in the width direction from the joining portions in the inner first row to the joining portions in the inner second row, at least one of the joining portions is formed in the direction in which the joining region extends.

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