Elastic sheet, absorbent article, and underpants-type absorbent article

Abstract

An elastic sheet (20, 40) in which an elastic member (23) is disposed between a pair of sheets (21, 22) joined by a welded section (50), the elastic member (23) having a first welded section pair (51a1) and a second welded section pair (50a2) located aside on one side in the left-right direction, the position of the elastic member (23) being restricted by being sandwiched between the welded section pairs in a state in which the elastic member (23) is contracted in the left-right direction, and the first welded section pair (51a1) and the second welded section pair (50a2) being located aside on one side in the left-right direction. The first welded part pair (51a1) has a first welded part (501) and a second welded part (502) positioned at a first interval in the left-right direction on the same side in the up-down direction with respect to the elastic member (23), and the first welded part pair (51a1) has a first welded part (501) and a second welded part (502) positioned at a second interval in the left-right direction. The length in the left-right direction from the end on one side in the left-right direction of the first welded section pair (51a1) to the end on the other side in the left-right direction of the second welded section pair (51a2) is greater than the length in the left-right direction of the first gap.

Description

Technical Field

[0001] The present invention relates to a stretchable sheet, an absorbent article, and a pants-type absorbent article. Background Art

[0002] Patent Document 1 discloses a stretchable sheet in which an elastic member (string-like member) is arranged between fold lines (tubular sleeves) of the sheet, and connecting parts for connecting two sheets are formed on both sides in a direction across the elastic member. When tension is applied to the elastic member, the elastic member can be detached from between the connecting parts, and when tension is not applied, the elastic member is fixed to the narrow part between the connecting parts.

[0003] Prior Art Literature

[0004] Patent Literature

[0005] Patent Document 1: Japanese Patent No. 3212615 Summary of the invention

[0006] Problems to be solved by the invention

[0007] The rigidity of the sheet increases at the connection portion (weld portion) formed by heat pressing etc. Therefore, by shortening the length of the weld portion sandwiching the elastic member (the length along the direction of the elastic member), the flexibility of the sheet can be ensured.

[0008] However, if the length of the weld is shortened, the force of the elastic member clamped in the narrow part between the welds (between the weld pairs) will be small, and the elastic member to be contracted cannot be completely fixed, and the elastic member is easy to be separated from between the weld pairs.

[0009] The present invention has been made in view of the above-mentioned problems, and an object of the present invention is to ensure the flexibility of a stretchable sheet, suppress detachment of an elastic member from between a pair of welded portions, and suppress a decrease in stretchability.

[0010] Solutions to Solve Problems

[0011] The main invention for achieving the above-mentioned purpose is a stretchable sheet, which has an up-down direction and a left-right direction that intersect each other, and a plurality of elastic members that can stretch and contract along the left-right direction are arranged at intervals in the up-down direction between a pair of sheets joined by a plurality of welded portions, characterized in that the plurality of welded portions have a plurality of welded portion pairs located on both sides of the elastic members in the up-down direction, and each of the elastic members is restricted in position in the left-right direction relative to the pair of sheets by being sandwiched between the welded portion pairs in a state of being contracted along the left-right direction, and the plurality of welded portion pairs have: a first welded portion pair; and a welded portion pair located at the first A second weld portion pair is located next to one side of the weld portion pair in the left-right direction, the first weld portion pair and the second weld portion pair both sandwich the first elastic member, the first weld portion pair is on the same side of the up-down direction based on the first elastic member, and has a first weld portion and a second weld portion positioned with a first interval in the left-right direction, and in a state extended along the left-right direction, a length in the left-right direction from an end of the first weld portion pair on one side in the left-right direction to an end of the second weld portion pair on the other side in the left-right direction, i.e., a first length, is greater than a length of the first interval in the left-right direction.

[0012] Other features of the present invention will become apparent from the description of this specification and the accompanying drawings.

[0013] Effects of the Invention

[0014] According to the present invention, the flexibility of the stretchable sheet can be ensured, and the elastic member can be prevented from falling out between the welded portion pairs, thereby preventing a decrease in stretchability. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 It is a schematic perspective view of the underpants-type disposable diaper 1.

[0016] Figure 2 This is a schematic plan view of the diaper 1 in the unfolded and stretched state as viewed from the skin side of the wearer.

[0017] Figure 3 yes Figure 2 A schematic cross-sectional view at A-A in FIG.

[0018] Figure 4 It is an explanatory diagram of the welded portion rows Ra and Rb provided in the abdominal waistline portion 20 .

[0019] Figure 5A as well as Figure 5B This is an explanatory diagram of the attachment function of the waist elastic member 23.

[0020] Fig. 6AThis is a diagram showing a partial enlargement of the welded portion arrays Ra and Rb. Figure 6B It is an explanatory diagram of a conventional welded portion pair 51b.

[0021] Figure 7 It is an explanatory diagram of the disconnected fusion-bonded portion pair 51a.

[0022] Fig. 8A 1 is an explanatory diagram of the disconnected welded portion pair 51a in the extended state. Figure 8B as well as Figure 8C It is an explanatory diagram of the split and welded portion pair 51a in a contracted state.

[0023] Figures 9A to 9C It is an explanatory diagram of a modification of the split fusion-bonded portion pair 51a.

[0024] Fig. 10A as well as Fig. 10B It is an explanatory diagram of a modification of the split fusion-bonded portion pair 51a.

[0025] Fig.11 The diagram shows the relationship between the patterns of the compressed portions 60 and 61 of the skin-side sheet 21 and the non-skin-side sheet 22 and the non-fusion-bonded portion 52 .

[0026] Fig. 12A as well as Fig. 12B It is an explanatory diagram of the waist elastic member 23.

[0027] Fig.13 It is an explanatory diagram of the split fusion bonded portion pair 51 a provided in the side portion of the absorbent body 10 and in the vicinity of the side joint portion SS.

[0028] Fig.14 It is a top view of the state which unfolded the belt type diaper 2 in the longitudinal direction. DETAILED DESCRIPTION

[0029] At least the following matters will be clarified based on the description of this specification and the accompanying drawings.

[0030] Mode 1 is a stretchable sheet having mutually intersecting up-down directions and left-right directions, wherein between a pair of sheets joined by a plurality of welded portions, a plurality of elastic members that can stretch and contract in the left-right direction are arranged at intervals in the up-down direction, characterized in that the plurality of welded portions have a plurality of welded portion pairs located on both sides of the elastic members in the up-down direction, and each of the elastic members is restricted in position in the left-right direction relative to the pair of sheets by being sandwiched between the welded portion pairs when contracted in the left-right direction, and the plurality of welded portion pairs have: a first welded portion pair; and a The second weld portion pair is next to one side in the left-right direction, the first weld portion pair and the second weld portion pair both sandwich the first elastic member, the first weld portion pair is on the same side in the up-down direction based on the first elastic member, and has the first weld portion and the second weld portion positioned with a first interval in the left-right direction, and in a state extended along the left-right direction, the length in the left-right direction from the end of the first weld portion pair on one side in the left-right direction to the end of the second weld portion pair on the other side in the left-right direction, i.e., the first length, is greater than the length of the first interval in the left-right direction.

[0031] According to the first aspect, the sheet shrinks and the fiber density increases in the non-welded portion of the first interval smaller than the first length as the interval between the welded portion pairs. Therefore, the fibers are easily wound around the elastic member in the non-welded portion, and the detachment of the elastic member from the first welded portion pair can be further suppressed, thereby ensuring the elasticity of the stretch sheet. In addition, by providing the non-welded portion in the first welded portion pair, the interval between the welded portion pairs adjacent in the left-right direction is also large, and the welded portions are not densely arranged in the left-right direction, thereby also ensuring the softness of the stretch sheet.

[0032] Mode 2 is a stretchable sheet as described in Mode 1, characterized in that, in a state stretched in the left-right direction, the length of the first interval in the left-right direction is less than the length of the first weld in the left-right direction, and less than the length of the second weld in the left-right direction.

[0033] According to the second aspect, the sheet between the long first and second welded portions (first interval) can be firmly sandwiched, and the fiber density of the sheet can be increased. Therefore, the fibers are easily wound around the elastic member, and the elastic member can be prevented from detaching from the first welded portion pair.

[0034] Aspect 3 is the stretchable sheet according to aspect 1 or 2, wherein in a state stretched in the left-right direction, the first length is greater than a length of the first welded portion pair in the left-right direction.

[0035] According to method 3, in the first weld portion pair, multiple weld portions are adjacent to each other with a first interval, and the length in the left-right direction is longer. By arranging the weld portion pairs in the left-right direction with an interval (first length) larger than the length of the first weld portion pair, the softness of the stretch sheet can be ensured.

[0036] Mode 4 is a stretchable sheet as described in any one of Modes 1 to 3, characterized in that the second weld portion has a third weld portion and a fourth weld portion positioned at a second interval in the left-right direction on the same side of the up-down direction based on the first elastic member, and when stretched in the left-right direction, the first length is greater than the length of the second interval in the left-right direction.

[0037] According to the fourth embodiment, fibers in not only the first welded portion pair but also the second interval non-welded portion in the second welded portion pair are easily entangled with the elastic member, and the detachment of the elastic member from the welded portion pair can be more reliably suppressed, thereby ensuring the stretchability of the stretchable sheet.

[0038] Mode 5 is a stretchable sheet as described in any one of Modes 1 to 4, characterized in that the first weld portion has one or more fifth weld portions arranged with a gap between the first weld portion and the second weld portion in the left-right direction on the same side of the up-down direction based on the first elastic member, and in a state stretched in the left-right direction, the first length is greater than the length in the left-right direction of the gap between the fifth weld portion and the first weld portion or the fifth weld portion adjacent to the fifth weld portion in the left-right direction.

[0039] According to method 5, the fiber density of the sheet can be increased in the non-welded portions having intervals smaller than the first length as the interval between the welded portion pair. In addition, there are two or more non-welded portions having increased fiber density, thereby further suppressing the detachment of the elastic member from the first welded portion pair.

[0040] Method 6 is a stretchable sheet as described in Method 5, characterized in that, in a state stretched along the left-right direction, the length in the left-right direction of the interval between the fifth weld and the first weld adjacent to the fifth weld or the fifth weld adjacent to the fifth weld in the left-right direction is less than the lengths in the left-right direction of each of the first weld, the second weld and the fifth weld.

[0041] According to the sixth aspect, the long first, second and fifth welded portions can firmly sandwich the sheet therebetween, thereby increasing the fiber density of the sheet.

[0042] Therefore, the fibers are easily entangled with the elastic member, and the detachment of the elastic member from the first fusion portion pair can be further suppressed.

[0043] Mode 7 is a stretchable sheet as described in any one of Modes 1 to 6, characterized in that the above-mentioned first weld portion has a sixth weld portion and a seventh weld portion positioned at a third interval along the above-mentioned left-right direction on the side opposite to the above-mentioned same side in the above-mentioned up-down direction based on the above-mentioned first elastic member.

[0044] According to the seventh aspect, by positioning the non-welded portions on both sides of the elastic member in the vertical direction, the non-welded portions are easily contracted in the horizontal direction, and the fiber density is easily increased. In addition, the fibers are easily wound around the elastic member from both sides in the vertical direction, and the detachment of the elastic member from the first welded portion pair can be further suppressed.

[0045] Mode 8 is a stretchable sheet as described in Mode 7, characterized in that, in a state stretched along the left-right direction, the first interval and the third interval have overlapping areas in the left-right direction, and the center of the first interval in the left-right direction and the center of the third interval in the left-right direction are offset in the left-right direction.

[0046] According to the eighth aspect, at the portion where the non-welded portion and the welded portion overlap in the left-right direction at the first interval or the third interval, the elastic member receives force from the welded portion on one side in the up-down direction, and receives force from the non-welded portion with high fiber density on the other side in the up-down direction. Therefore, the fibers are easily entangled with the elastic member.

[0047] Mode 9 is a stretchable sheet as described in Mode 8, characterized in that the stretchable sheet has a plurality of eighth welds arranged at intervals from the first weld in the up-down direction, the stretchable sheet has a ninth weld arranged at intervals from the second weld in the up-down direction, the eighth weld is positioned offset in the left-right direction from the first weld or the eighth weld adjacent to the up-down direction, the ninth weld is positioned offset in the left-right direction from the second weld or the ninth weld adjacent to the up-down direction, and in a state stretched in the left-right direction, the first length is greater than the length in the left-right direction of the interval between the eighth weld and the ninth weld adjacent to the left-right direction.

[0048] According to method 9, the portion of the elastic member located in the non-welded portion of the first interval also overlaps with the 8th welded portion and the 9th welded portion arranged in the up-down direction in the left-right direction, and is therefore easily affected by the 8th welded portion and the 9th welded portion, and the fibers are easily entangled on the elastic member.

[0049] Mode 10 is a stretchable sheet as described in any one of Modes 1 to 9, characterized in that the pair of sheets respectively have a plurality of compressed portions compressed in the thickness direction of the sheet, and when the stretchable sheet in a state extended in the left-right direction is viewed from above, at least a portion of the plurality of compressed portions of one sheet of the pair of sheets has an area that does not overlap with the compressed portions of the other sheet.

[0050] According to the tenth aspect, by making the compressed portions of a pair of sheets not completely overlap, it is easy to position the uncompressed fibers of one sheet at the non-welded portion of the first interval. Therefore, the fibers are easily entangled with the elastic member at the non-welded portion, and the elastic member can be prevented from being separated from the first welded portion pair.

[0051] Mode 11 is a stretchable sheet as described in any one of modes 1 to 10, characterized in that at least one of the pair of sheets has a plurality of compressed portions compressed in the thickness direction of the sheet, and when the stretchable sheet in a state extended in the left-right direction is viewed from above, the first interval has an area that does not overlap with the compressed portion.

[0052] According to aspect 11, the uncompressed fibers of the sheet are positioned at the non-fused portions of the first intervals, so that the fibers are easily entangled with the elastic member at the non-fused portions, and separation of the elastic member from the first fused portions can be suppressed.

[0053] Mode 12 is a stretchable sheet as described in any one of Modes 1 to 11, characterized in that at least one of the pair of sheets has a plurality of compressed portions compressed in the thickness direction of the sheet, and in a state stretched along the left-right direction, the length of the first interval in the left-right direction is less than the maximum value in the left-right direction of the interval between the compressed portions adjacent to each other in the left-right direction.

[0054] According to aspect 12, the first interval non-welded portion can be easily positioned between the compression portions adjacent to each other in the left-right direction. Therefore, the fibers can be easily entangled with the elastic member in the non-welded portion, and the elastic member can be prevented from being separated from the first welded portion pair.

[0055] Mode 13 is a stretchable sheet as described in any one of Modes 1 to 12, characterized in that when a length twice the thickness of at least one of the pair of sheets is set as the second length, in a state stretched along the left-right direction, the length of the first interval in the left-right direction is greater than the second length.

[0056] According to aspect 13, the non-welded portion of the first interval is not too narrow, the sheet can bend in the non-welded portion, and the fiber density of the sheet can be increased. Therefore, it is possible to suppress the elastic member from being separated from the first welded portion pair.

[0057] Aspect 14 is the stretch sheet according to any one of aspects 1 to 13, wherein the first elastic member is disposed between the pair of sheets in a twisted state.

[0058] According to aspect 14, the dense fibers of the non-welded portion of the first interval are easily entangled with the torsion portion of the elastic member, and the detachment of the elastic member from the welded portion pair can be suppressed.

[0059] Mode 15 is a stretchable sheet as described in any one of Modes 1 to 14, characterized in that the above-mentioned first elastic member is a linear elastic member that is a collection of multiple elastic fibers, and has a first outer diameter portion with an outer diameter of the first outer diameter and a second outer diameter portion with an outer diameter smaller than the above-mentioned first outer diameter.

[0060] According to the fifteenth aspect, even if a part of the elastic fibers are disconnected, the remaining elastic fibers can maintain the connection, and the disconnection of the elastic member can be suppressed. In addition, in the first outer diameter portion with a large thickness, a strong friction force is easily generated between it and the welded portion, and the fibers of the non-welded portion of the first interval are easily entangled. Therefore, the separation of the elastic member from the welded portion can be further suppressed.

[0061] Mode 16 is a stretchable sheet as described in any one of Modes 1 to 15, characterized in that the plurality of weld portion pairs include a third weld portion pair located next to the other side of the left-right direction of the first weld portion pair and sandwiching the first elastic member, and in a state stretched along the left-right direction, a length in the left-right direction from the end of the other side of the left-right direction of the first weld portion pair to the end of the one side of the left-right direction of the third weld portion pair is greater than a length in the left-right direction of the first interval.

[0062] According to aspect 16, the first welded portion pairs are positioned at relatively large intervals (first lengths) on both sides of the first welded portion pairs in the left-right direction. Therefore, the welded portion pairs can be prevented from being densely arranged in the left-right direction, and the flexibility of the stretch sheet can be ensured.

[0063] Mode 17 is an absorbent article, which has a stretch sheet described in any one of modes 1 to 16, and is characterized in that the absorbent article has an up-down direction and a left-right direction that intersect each other, the up-down direction of the stretch sheet is along the up-down direction of the absorbent article, and the left-right direction of the stretch sheet is along the left-right direction of the absorbent article, and the first elastic member has: a discontinuous portion in which the first elastic member is cut discontinuously in the center of the absorbent article in the left-right direction; and a continuous portion located on the outside of the discontinuous portion in the left-right direction, and the first welded portion is sandwiched between the end portions on the center side of the continuous portion in the left-right direction.

[0064] According to aspect 17, fibers of the sheet in the first interval non-welded portion are easily entangled at the cut end of the elastic member cut by the discontinuous portion, and the elastic member is unlikely to be separated from the first welded portion, thereby ensuring the stretchability of the stretchable sheet.

[0065] Mode 18 is an absorbent article, which has a stretch sheet according to any one of Modes 1 to 17, characterized in that the absorbent article has an up-down direction and a left-right direction that intersect each other, the up-down direction of the stretch sheet is along the up-down direction of the absorbent article, and the left-right direction of the stretch sheet is along the left-right direction of the absorbent article, the stretch sheet has a fourth weld portion pair that sandwiches the first elastic member, the fourth weld portion pair is on the same side of the up-down direction based on the first elastic member, and has a plurality of weld portions arranged at intervals along the left-right direction, the first weld portion pair is located at the end portion of the absorbent article in the left-right direction, the fourth weld portion pair is located in the center portion of the absorbent article in the left-right direction, and the length of the first weld portion pair in the left-right direction is greater than the length of the fourth weld portion pair in the left-right direction.

[0066] According to aspect 18, the side joints of a pull-on diaper or the hook and loop fasteners of a tape diaper are positioned at the ends in the left-right direction of the absorbent article, so that the elastic member is easily cut.

[0067] Therefore, by the long first welding part pair, the elastic member can be suppressed from being separated from the first welding part pair, and the elasticity of the stretchable sheet can be ensured. On the other hand, by suppressing the length of the fourth welding part pair, the elastic member can be suppressed from being separated from the fourth welding part pair, and the softness of the stretchable sheet can be ensured.

[0068] Mode 19 is a panty-type absorbent article, which has a stretch sheet described in any one of modes 1 to 18, and is characterized in that the above-mentioned panty-type absorbent article has mutually intersecting up-down directions and left-right directions, and has an absorbent body and a pair of waistline parts, and the above-mentioned stretch sheet is provided on at least one of the above-mentioned pair of waistline parts, the above-mentioned up-down direction of the above-mentioned stretch sheet is along the above-mentioned up-down direction of the above-mentioned panty-type absorbent article, and the above-mentioned left-right direction of the above-mentioned stretch sheet is along the above-mentioned left-right direction of the above-mentioned panty-type absorbent article, and the above-mentioned pair of waistline parts are joined by a pair of side joints on both sides of the above-mentioned left-right direction, and in a state stretched along the above-mentioned left-right direction, at least a portion of the above-mentioned first welded portion pair is located in the area of ​​the above-mentioned first length from the end of the inside of the above-mentioned side joint in the left-right direction toward the inside of the above-mentioned left-right direction.

[0069] According to aspect 19, even if the elastic member is cut at the side joint portion, the elastic member is easily sandwiched by the first welded portions near the side joint portion, and stretchability can be ensured over a wide range in the left-right direction of the stretchable sheet.

[0070] ===First Embodiment===

[0071] In the first embodiment, as an absorbent article (underwear-type absorbent article) using a stretchable sheet, an underwear-type disposable diaper for adults is taken as an example and described.

[0072] <<Basic structure of underpants type disposable diaper 1>>

[0073] Figure 1 It is a schematic perspective view of a pull-on disposable diaper 1 (hereinafter also referred to as a "diaper").

[0074] Figure 2 This is a schematic plan view of the diaper 1 in the unfolded and stretched state as viewed from the skin side of the wearer. Figure 3 yes Figure 2 A schematic cross-sectional view at A-A in FIG.

[0075] The diaper 1 has a vertical direction, a horizontal direction, and a front-back direction that intersect each other, and has a waist opening BH and a pair of leg openings LH. In the vertical direction, the waist opening BH side is set as the upper side, and the side that will become the crotch side of the wearer is set as the lower side. In the front-back direction, the side that will become the belly side of the wearer is set as the front side, and the side that will become the back side is set as the back side. In addition, the diaper 1 is as shown in FIG. Figure 3 As shown in the figure, the material is layered in the thickness direction, and the side in contact with the wearer in the thickness direction is set as the skin side, and the opposite side is set as the non-skin side.

[0076] The diaper 1 includes an absorbent body 10 and a pair of waist portions 20, 30. The pair of waist portions 20, 30 are joined to the non-skin side of the absorbent body 10 by adhesive or the like. The waist portion located on the front side of the pair of waist portions 20 is also referred to as the ventral waist portion 20, and the waist portion located on the rear side is also referred to as the dorsal waist portion 30. The ventral waist portion 20 and the dorsal waist portion 30 are joined at both sides in the left-right direction by a pair of side joining portions SS. Examples of the joining method using the side joining portions SS include a joining method using heat fusion, ultrasonic fusion or adhesive, and the like.

[0077] like Figure 3As shown in the figure, the absorbent body 10 comprises: an absorbent core 11; a liquid-permeable top sheet 12 arranged on the skin side relative to the absorbent core 11; a liquid-impermeable back sheet 13 arranged on the non-skin side relative to the absorbent core 11; and an outer sheet 14. The absorbent core 11 can be any structure as long as it absorbs and retains excrement, for example, a structure in which a liquid-absorbent material such as pulp fiber or superabsorbent polymer is formed into a predetermined shape. In addition, the absorbent core 11 can also be covered with a liquid-permeable sheet such as tissue paper or nonwoven fabric.

[0078] like Figure 2 As shown in the figure, a leg elastic member 15 (e.g., rubber thread) that stretches and contracts along the length direction of the absorbent body 10 may also be provided on both sides of the absorbent body 10 in the left-right direction. Furthermore, a leak-proof wall that can stand up toward the skin side may also be provided at a position that is closer to the inside of the leg elastic member 15 in the left-right direction. The leak-proof wall is formed, for example, by folding back both sides of the outer sheet 14 in the left-right direction toward the inside of the left-right direction in a manner that is located on the skin side of the top sheet 12, and providing a leak-proof wall elastic member 16 (e.g., rubber thread) that stretches and contracts in the length direction at the folded-back position.

[0079] In the present embodiment, the part overlapping with the side joint part SS in the up-down direction is set as the waistline part 20, 30, and the ventral waistline part 20 and the dorsal waistline part 30 are rectangular parts in a top view. On the lower crotch side of the dorsal waistline part 30, a roughly trapezoidal extension part 30E is provided. The wearer's buttocks can be covered by the extension part 30E. In the following description, the dorsal waistline part 30 and the extension part 30E are also referred to as the dorsal outerwear part 30, 30E. However, it is not limited to the above-mentioned structure, for example, it can also be a structure without the extension part 30E on the dorsal side, and it can also be a structure with a part extending from the ventral waistline part 20 toward the lower crotch side.

[0080] The ventral waistline portion 20 and the back outerwear portion 30, 30E respectively have skin side sheets 21, 31, non-skin side sheets 22, 32 and waist elastic components 23, 33 (such as rubber threads) that can be stretched in the left and right directions. A plurality of waist elastic components 23, 33 are arranged at intervals between the skin side sheets 21, 31 and the non-skin side sheets 22, 32 in the up and down directions.

[0081] As the skin side sheets 21, 31 and the non-skin side sheets 22, 32, soft sheet members are preferred, and examples thereof include spunbond nonwoven fabrics, meltblown nonwoven fabrics, SMS (spunbond / meltblown / spunbond) nonwoven fabrics, etc. The constituent fibers of the nonwoven fabrics are not limited to single fibers of polypropylene (PP), which is a representative example of thermoplastic resins, but single fibers of other thermoplastic resins such as polyethylene (PE) can also be used, and composite fibers having a sheath-core structure of PE and PP can also be used.

[0082] The basic structure of the diaper 1 is described above, but the structure of the diaper 1 is only an example and is not limited to this. For example, in the diaper 1 of this embodiment, the ventral waistline portion 20 and the dorsal outer covering portions 30, 30E are composed of independent components, and the non-skin side of the absorbent body 10 is exposed in the crotch portion. This is not limited to this. For example, it is also possible to have an outer covering member composed of three components, namely, the ventral waistline portion 20, the dorsal outer covering portions 30, 30E, and the crotch portion connecting them, or it is also possible to have an outer covering member composed of one component continuous from the ventral waistline portion 20 to the dorsal waistline portion 30.

[0083] <<About the waistline portions 20 and 30 (elastic sheet 40)>>

[0084] Figure 4 It is an explanatory diagram of the welded portion rows Ra and Rb provided in the abdominal waistline portion 20 . Figure 5A as well as Figure 5B This is an explanatory diagram of the attachment function of the waist elastic member 23. Fig. 6A This is a diagram showing a partial enlargement of the welded portion arrays Ra and Rb. Figure 6B It is an explanatory diagram of a conventional welded portion pair 51b.

[0085] exist Figure 4 , Fig. 6A , Figure 6B In the accompanying drawings, the state of the ventral waistline 20 (elastic sheet 40) when stretched in the left-right direction is shown. The state in which the waistline 20, 30 or the elastic sheet 40 is stretched in the left-right direction means that the stretching is such that wrinkles are not substantially seen on the waistline 20, 30 or the elastic sheet 40, and the size of each component (such as the skin side sheet 21, etc.) constituting the waistline 20, 30 or the elastic sheet 40 is stretched to a length that is consistent with or close to the size of its component monomer (i.e., the size of the elastic component when it is not elastic).

[0086] <Regarding the Position Limitation of the Waist Elastic Member 23>

[0087] The ventral waistline 20 and the dorsal waistline 30 are composed of a stretch sheet 40, and the stretch sheet 40 is provided with a plurality of waist elastic members 23, 33 (elastic members) that can stretch in the left and right directions at intervals in the vertical direction between the skin side sheets 21, 31 and the non-skin side sheets 22, 32 joined by a plurality of welded parts 50 (between a pair of sheets). Fig. 6A As shown, the skin side sheets 21, 31 and the non-skin side sheets 22, 32 are intermittently joined by a plurality of welded portions 50 discretely arranged in the vertical direction and the horizontal direction. The welded portions 50 can be formed by a known welding method such as ultrasonic welding or heat welding.

[0088] The pair of sheets joined by the welding part 50 may be two independent sheets like the skin side sheets 21, 31 and the non-skin side sheets 22, 32 of the present embodiment, or may be a sheet formed into two layers by folding back one sheet. In addition, the welding part 50 is not limited to joining only a pair of sheets sandwiching the waist elastic members 23, 33, but may also join three or more layers of sheets together with the sheets stacked on the pair of sheets.

[0089] Since the abdominal waistline portion 20 and the dorsal waistline portion 30 have substantially the same configuration, the abdominal waistline portion 20 will be described below as a representative of the two.

[0090] The abdominal waistline portion 20 (elastic sheet 40) has a plurality of welded portion rows Ra and Rb in which a plurality of welded portions 50 are arranged in the vertical direction. The plurality of welded portion rows Ra and Rb are arranged at intervals in the horizontal direction. Figure 4 As shown in FIG. 1 , the welded portion rows Ra and Rb of the present embodiment extend in the vertical direction while zigzagging in the horizontal direction. Fig. 6A As shown in FIG. 1 , the positions of the welded portions 50 adjacent to each other in the vertical direction are shifted in the horizontal direction.

[0091] On the other hand, the positions of the welded portions 50 adjacent to each other in the left-right direction in the vertical direction are aligned. Figure 5A As shown in the figure, the vertical positions of the spaces through which the waist elastic members 23 pass between the welded portions 50 adjacent in the vertical direction are aligned, so that the waist elastic members 23 can be arranged in the left-right direction. However, the present invention is not limited thereto, and the vertical positions of the welded portions 50 adjacent in the left-right direction may be staggered, and the waist elastic members 23 may pass between welded portions 50 at different vertical positions. In these cases, the ventral waist portion 20 can also be provided with stretchability in the left-right direction.

[0092] like Figure 5A As shown in the figure, the two welds 50 located on both sides of the waist elastic member 23 in the vertical direction are also referred to as "weld pair 51". The upper weld 50 and the lower weld 50 constituting the weld pair 51 are arranged in the vertical direction with a gap GH50 therebetween. The size of the gap GH50 is set to be the same as or slightly larger than the outer diameter d1 of the waist elastic member 23 in the state where the ventral waist portion 20 is stretched to the maximum in the left-right direction (GH50 ≥ d1).

[0093] However, the waist elastic member 23 becomes thicker as it contracts in the left-right direction. Figure 5BAs shown, the interval GH50 of the welding part 51 is smaller than the maximum outer diameter d2 of the waist elastic member 23 in the state of contraction in the left and right directions (that is, the natural state of the abdominal waist circumference 20) (GH50<d2). By constituting in this way, the waist elastic member 23 in the state of contraction in the left and right directions is sandwiched between the welding part 51 (the enlargement in the up and down direction is limited). Therefore, the position (activity) of the waist elastic member 23 in the left and right directions and the up and down directions relative to the skin side piece 21 and the non-skin side piece 22 is limited.

[0094] Therefore, even if the waist elastic member 23 is fixed to the skin side sheet 21 and the non-skin side sheet 22 without using an adhesive, the positional deviation of the waist elastic member 23 can be suppressed, and the elasticity of the ventral waist portion 20 can be maintained. That is, by using the welded portion 50, the waist elastic member 23 can be installed on the skin side sheet 21 and the non-skin side sheet 22 without using an adhesive or with a reduced amount of adhesive. Therefore, the softness of the ventral waist portion 20 (elastic sheet 40) can be suppressed from being reduced due to the hardening of the adhesive. In addition, the elasticity of the waist elastic member 23 can be suppressed from being reduced due to the hardening of the adhesive.

[0095] In addition, in the ventral waist circumference portion 20, the waist elastic member 23 is fixed to the skin side sheet 21 and the non-skin side sheet 22 at the side joint portion SS. Specifically, when the diaper 1 is manufactured, the waist elastic member 23 in the stretched state is sandwiched between the skin side sheet 21 and the non-skin side sheet 22 to form the side joint portion SS, and the end of the waist elastic member 23 is fixed to the side joint portion SS. Therefore, even if the ventral waist circumference portion 20 is greatly stretched when the diaper 1 is worn, the waist elastic member 23 can be prevented from being separated from between the welding portion pair 51, and the elasticity of the ventral waist circumference portion 20 can be maintained.

[0096] In addition, the relationship between the interval GH50 of the welding part pair 51 and the outer diameters d1 and d2 of the waist elastic member 23 is not limited to the above-mentioned structure. For example, it can also be set to a degree that the waist elastic member 23 is not cut so that a part of the waist elastic member 23 overlaps with the welding part 50. In this case, the waist elastic member 23 is sandwiched between the welding part pair 51 in a state of contraction in the left-right direction, and the position of the left-right direction and the up-down direction relative to the skin side sheet 21 and the non-skin side sheet 22 is restricted.

[0097] In addition, not all waist elastic members 23 (elastic members) disposed on the ventral waist portion 20 (elastic sheet 40) are clamped by the welded portion pair 51 and their positions are restricted. As long as at least a portion of the waist elastic members 23 is restricted in position by the welded portion pair 51, the other portion of the waist elastic members 23 may be fixed to the skin side sheet 21 and the non-skin side sheet 22 by adhesive.

[0098] <<About the disconnection welded portion array Ra>>

[0099] Figure 7 It is an explanatory diagram of the disconnected fusion-bonded portion pair 51a. Fig. 8A 1 is an explanatory diagram of the disconnected welded portion pair 51a in the extended state. Figure 8B as well as Figure 8C It is an explanatory diagram of the split and welded portion pair 51a in a contracted state. Figures 9A to 9C , Fig. 10A as well as Fig. 10B It is an explanatory diagram of a modification of the split fusion-bonded portion pair 51a. Fig.11 The diagram shows the relationship between the patterns of the compressed portions 60 and 61 of the skin-side sheet 21 and the non-skin-side sheet 22 and the non-fusion-bonded portion 52 .

[0100] like Figure 4 , Fig. 6A As shown in the figure, the abdominal waistline portion 20 (elastic sheet 40) has two types of welded portion rows, namely, "disconnected welded portion row Ra" and "regular welded portion row Rb". In the abdominal waistline portion 20, a plurality of welded portion rows Ra and Rb are arranged at a predetermined interval D1 in the left-right direction. As the interval D1 in the left-right direction of the welded portion rows Ra and Rb, a length of about 4 to 14 times the length La of the welded portion 50 in the left-right direction can be exemplified, and a plurality of welded portion rows Ra and Rb are arranged at a large interval.

[0101] In the following description, the weld pair 51 sandwiching the waist elastic member 23 among the welds 50 belonging to the split weld column Ra is referred to as a "split weld pair 51a". In addition, the weld pair 51 sandwiching the waist elastic member 23 among the welds 50 belonging to the regular weld column Rb is referred to as a "regular weld pair 51b".

[0102] like Fig. 6A As shown in FIG. 1 , in the normal welded portion row Rb, the welded portions 50 are arranged in a row in the vertical direction. Figure 6B As shown, the normal welded portion pair 51 b is composed of two welded portions 50 disposed one each on both sides of the waist elastic member 23 in the up-down direction.

[0103] On the other hand, in the separation welded portion row Ra, two welded portion rows are formed by a group of two welded portions 50 adjacent to each other at a small interval in the left-right direction and arranged in the vertical direction. Figure 7 As shown, the split weld portion pair 51 a is composed of four weld portions 50 , two of which are arranged on both sides of the waist elastic member 23 in the up-down direction.

[0104] Regarding the disconnection of the welded portion pair 51a, the Figure 7 For more details, please refer to the following sections. Figure 7In the figure, the disconnected welding portion pair 51a arranged at a position close to the side joint portion SS is referred to as the "first disconnected welding portion pair 51a1 (first welding portion pair)". The disconnected welding portion pair 51a located next to one side in the left-right direction is referred to as the "second disconnected welding portion pair 51a2 (second welding portion pair)". The first disconnected welding portion pair 51a1 and the second disconnected welding portion pair 51a2 both clamp the same waist elastic member 23 (first elastic member).

[0105] The first split weld portion pair 51a1 includes a first weld portion 501 and a second weld portion 502 located at a first interval S1 in the left-right direction on the same side (here, the lower side) in the up-down direction with respect to the waist elastic member 23 .

[0106] Furthermore, when the abdominal waistline portion 20 is extended in the left-right direction, the left-right length D1 (first length) from the end of one side of the left-right direction of the first disconnected welded portion pair 51a1 to the end of the other side of the left-right direction of the second disconnected welded portion pair 51a2 is greater than the left-right length Lb of the first interval S1 (D1>Lb).

[0107] In the following description, the length D1 is also referred to as "the weld portion pair interval D1". In addition, the length Lb of the first interval S1 in the left-right direction refers to the length from the end of the first weld portion 501 on the other side in the left-right direction (the second weld portion 502 side) to the end of the second weld portion 502 on one side in the left-right direction (the first weld portion 501 side). The same applies to the lengths of the other intervals (the second interval S2 and the third interval S3) described later.

[0108] As described above, in the split welded portion pair 51a, a portion of the welded portion 50 is separated on one side of the waist elastic member 23 in the vertical direction, and a non-welded portion 52 is formed between the welded portions (501 and 502) arranged in the left-right direction. The non-welded portion 52 is a region having a length substantially the same as the left-right length Lb of the first interval S1, and is a smaller region than the welded portion pair interval D1. Therefore, when the waist elastic member 23 contracts ( Figure 8B ), the two welded parts (501 and 502) on both outer sides of the non-welded part 52 are close to each other, and the skin side sheet 21 and the non-skin side sheet 22 (hereinafter also referred to as "sheets 21, 22") located in the non-welded part 52 are sandwiched by the two welded parts (501 and 502). As a result, in the non-welded part 52, the density of the fibers constituting the sheets 21 and 22 becomes high.

[0109] like Figure 6BAs shown in the figure, a non-welded portion is also formed between the regular welded portion pair 51b arranged in the left-right direction. However, the non-welded portion is an area as large as the interval D1 between the welded portion pairs. Therefore, even if the waist elastic member 23 shrinks, it is difficult for the welded portion 50 to approach to a degree that increases the fiber density of the sheets 21 and 22 in the non-welded portion. In addition, if the length (D1) of the sheets 21 and 22 located between the non-welded portions is long, the sheets 21 and 22 are likely to bend more toward the outside of the thickness than the welded portion 50. Therefore, it is difficult to increase the fiber density of the sheets 21 and 22 without sandwiching the sheets 21 and 22 between the welded portions 50.

[0110] Therefore, as in the split welded portion pair 51a, a non-welded portion 52 having an interval Lb smaller than the interval D1 of the welded portion pair can be provided. Specifically, Lb is preferably 2.54 mm or less, and more preferably about 0.5 mm. With such a configuration, when the waist elastic member 23 contracts, the sheets 21 and 22 of the non-welded portion 52 can be sandwiched by the welded portions (501 and 502), and the fiber density of the sheets 21 and 22 can be increased in the non-welded portion 52. As a result, dense fibers can be easily entangled on the waist elastic member 23 in the non-welded portion 52, and the movement of the waist elastic member 23 can be restricted. Therefore, it is possible to suppress the waist elastic member 23 from detaching from the split welded portion pair 51a.

[0111] In particular, in the underpants-type diaper 1, in the process of forming the side joints SS when manufacturing the diaper 1, the sheets 21 and 22 are relatively strongly welded, so the waist elastic member 23 may be disconnected. In addition, when the diaper 1 is worn, when the diaper 1 is pulled up while holding the side joints SS, a strong pulling force acts on the side joints SS, and the waist elastic member 23 may be disconnected. Even if the waist elastic member 23 is separated from the side joints SS, the waist elastic member 23 contracted from the side joints SS is restrained by the split welded portion pair 51a, and the waist elastic member 23 can be prevented from being separated from the split welded portion pair 51a. Therefore, the elasticity of the ventral waist portion 20 can be prevented from being reduced.

[0112] In addition, even if the conventional welded portion 51b ( Figure 6B ) is formed, by lengthening the left-right length of the weld 50, the friction between the weld 50 and the waist elastic member 23 becomes higher, and the waist elastic member 23 can be suppressed from detaching from the conventional weld 51b. However, if the weld 50 with high rigidity is lengthened, the flexibility of the ventral waist portion 20 will be reduced.

[0113] In contrast, in the split welded portion pair 51a, the non-welded portion 52 is provided in a portion in the left-right direction. Therefore, compared with the case where the conventional welded portion pair 51a having the same length Lc as the split welded portion pair 51a is provided, the area ratio of the welded portion 50 in the left-right direction can be suppressed, and the flexibility of the abdominal waistline portion 20 can be ensured. In addition, the non-welded portion 52 can easily become a bending base point of the abdominal waistline portion 20 in the left-right direction. Therefore, the abdominal waistline portion 20 can be easily bent in the left-right direction and can be easily matched to the waist circumference of the wearer.

[0114] As described above, by providing the split welding portion pair 51a in the ventral waist portion 20 (elastic sheet 40), the detachment of the waist elastic member 23 can be suppressed, the reduction of elasticity can be suppressed, and the softness of the ventral waist portion 20 can be ensured. That is, the position of the waist elastic member 23 relative to the sheets 21 and 22 is restricted by the welding portion pair 51, and the softness of the ventral waist portion 20 can be ensured by suppressing the amount of adhesive used.

[0115] In addition, Figure 4 In the illustrated abdominal waistline portion 20, a disconnected welded portion row Ra (disconnected welded portion pair 51a) is arranged in a shape that meanders in the left-right direction near the side joint portion SS and near the side of the absorbent body 10. However, the shape, number or arrangement position of the disconnected welded portion row Ra is not particularly limited, as long as the abdominal waistline portion 20 (elastic sheet 40) has at least one disconnected welded portion pair 51a. Figure 7 In the figure, the shape of the weld 50 is a parallelogram, but the shape of the weld 50 is not particularly limited. In addition, the shapes of the plurality of welds 50 included in each weld row Ra, Rb may be the same or different.

[0116] In addition, the welded portion rows provided in the abdominal waistline portion 20 may all be the disconnected welded portion rows Ra, or may be a mixture of a normal welded portion row Rb consisting of one row and the disconnected welded portion row Ra. By configuring in this way, the waist elastic member 23 can be prevented from being separated from the welded portion pair 51, and the softness of the abdominal waistline portion 20 can be ensured.

[0117] In addition, when the ventral waistline portion 20 is stretched in the left-right direction, the left-right length Lb of the first interval S1 of the first split weld portion pair 51a1 can be less than the left-right length La of the first weld portion 501 and less than the left-right length La of the second weld portion 502 (Lb≤La).

[0118] By configuring in this way, the rigidity of the welded parts (501, 502) becomes high, and the non-welded parts 52 can be sandwiched therebetween. Therefore, in the non-welded parts 52, the fiber density of the sheets 21, 22 becomes high, and the fibers can be wound around the waist elastic member 23. In addition, as the welded parts (501, 502) become longer, the friction force generated between the welded parts (501, 502) and the waist elastic member 23 becomes higher, and the welded parts (501, 502) can restrict the movement of the waist elastic member 23. Therefore, it is possible to suppress the waist elastic member 23 from detaching from the split welded part pair 51a.

[0119] However, the present invention is not limited to the above configuration, and the left-right length Lb of the first interval S1 may be greater than the left-right length La of the first weld 501 or the second weld 502. The left-right length La of the first weld 501 and the second weld 502 may be the same or different.

[0120] In addition, when the abdominal waistline portion 20 is stretched in the left-right direction, it is preferable that the weld pair interval D1 is larger than the left-right length Lc of the entire first split weld pair 51a1 (D1>Lc).

[0121] By configuring in this way, the intervals between the welded portion rows Ra and Rb become larger, and the welded portions 50 can be prevented from being densely arranged in the left-right direction, thereby ensuring the flexibility of the abdominal waistline portion 20. In other words, it can be said that in the first disconnected welded portion pair 51a1, the lengths of the plurality of welded portions (501, 502) or the non-welded portions 52 in the left-right direction are short. Therefore, the flexibility of the abdominal waistline portion 20 can be ensured by the short welded portions (501, 502), and the fiber density of the sheets 21 and 22 can be increased in the short non-welded portions 52. However, the present invention is not limited to the above configuration, and the welded portion pair interval D1 may be less than the left-right length Lc of the first disconnected welded portion pair 51a1.

[0122] In addition, if Figure 7 As shown in the figure, the welded portion pair (second split welded portion pair 51a2) adjacent to the first split welded portion pair 51a in the left-right direction may also have the same structure, and may have the third welded portion 503 and the fourth welded portion 504 located at a second interval S2 in the left-right direction on the same side (here, the lower side) in the up-down direction with respect to the waist elastic member 23. Furthermore, when the abdominal waist portion 20 is stretched in the left-right direction, the welded portion pair interval D1 may be greater than the left-right length Lb of the second interval S2 (D1>Lb).

[0123] Thus, by arranging the split welded portion pair 51a continuously in the left-right direction, it is possible to more reliably suppress the waist elastic member 23 from being separated from the welded portion pair 51, and to suppress the reduction in the elasticity of the ventral waist portion 20. However, the present invention is not limited to the above-mentioned structure, and the welded portion pair (second welded portion pair) adjacent to the first split welded portion pair 51a in the left-right direction may be a normal welded portion pair 51b ( Figure 6B ).

[0124] In addition, you can also Fig. 10A as well as Fig. 10B As shown in the first split weld portion pair 51a1, one or more fifth weld portions 505 are arranged in the left-right direction with a gap between the first weld portion 501 and the second weld portion 502 on the same side in the up-down direction based on the waist elastic member 23. That is, three or more weld portions 50 may be provided on the same side in the up-down direction based on the waist elastic member 23.

[0125] Furthermore, when the ventral waistline portion 20 is stretched in the left-right direction, the interval D1 between the welded portions may be greater than the left-right length Lb ( Lb ) of the interval between the fifth welded portion 505 and the first welded portion 501 adjacent to the fifth welded portion 505 in the left-right direction. Fig. 10A , Fig. 10B ), and also, a length Lb in the left-right direction greater than the interval between the fifth fusion portions 505 adjacent to each other in the left-right direction ( Fig. 10B )(D1>Lb).

[0126] In this case, two or more non-welded portions 52 as small areas are formed on one side in the vertical direction of the waist elastic member 23. Therefore, the waist elastic member 23 is easy to be entangled with fibers at two locations, and the waist elastic member 23 can be further prevented from being separated from the split welded portion pair 51a.

[0127] In the above case, when the abdominal waistline portion 20 is stretched in the left-right direction, the left-right length Lb of the interval between the fifth weld 505 and the first weld 501 or the fifth weld 505 adjacent to the fifth weld 505 in the left-right direction may be less than the left-right length La of each weld (the first weld 501, the second weld 502, the fifth weld 505) (Lb≤La). With such a configuration, the left-right short non-weld portion 52 can be firmly sandwiched by the left-right long welds (501, 502, 505), and the fiber density of the non-weld portion 52 can be increased.

[0128] So far, attention has been paid to one side (lower side) in the up-down direction based on the waist elastic member 23, but the non-welded portion 52 may be provided on the opposite side. That is, the first split welded portion pair 51a1 includes the sixth welded portion 506 and the seventh welded portion 507 located at a third interval S3 in the left-right direction on the opposite side (upper side) in the up-down direction based on the waist elastic member 23. Furthermore, when the abdominal waist portion 20 is stretched in the left-right direction, the welded portion pair interval D1 may be larger than the left-right length Lb of the third interval S3 (D1>Lb).

[0129] By positioning the non-welded portions 52 as small areas on both sides of the waist elastic member 23 in the vertical direction, the non-welded portions 52 are easily contracted in the left-right direction, and the fiber density of the sheets 21 and 22 is easily increased in the non-welded portions 52. In addition, the fibers are easily wound around the elastic member from both sides in the vertical direction. As a result, the fibers are easily wound around the waist elastic member 23, and the waist elastic member 23 can be further prevented from being separated from the split welded portion pair 51a.

[0130] However, the configuration is not limited to the above configuration. For example, Fig.9A As in the modified example, on one side in the vertical direction, the welded portion 50 is not divided and does not have the non-welded portion 52. In this case, the length of the welded portion 50 without the non-welded portion 52 in the left-right direction can be shorter than the total length of the welded portions 501, 502 and the non-welded portion 52 on the opposite side in the vertical direction ( Fig.9A In addition, in the adjacent split welding portion pairs 51a1 and 51a2 in the left-right direction, the side where the non-welded portion 52 is located can be either the upper and lower opposite sides ( Fig.9A ), or the same side.

[0131] In addition, if Figure 8C As shown, when the ventral waist portion 20 is stretched in the left-right direction, the first interval S1 between the first weld portion 501 and the second weld portion 502 on the lower side of the waist elastic member 23 and the third interval S3 between the sixth weld portion 506 and the seventh weld portion 507 on the upper side can have an overlapping area in the left-right direction.

[0132] By configuring in this way, in the region where the first interval S1 and the third interval S3 overlap, the shrinkage of the non-welded portion 52 is less likely to be hindered by the welded portion 50 located on the opposite side in the up-down direction, and the shrinkage can be reliably achieved. Therefore, in the non-welded portion 52, the fiber density of the sheets 21, 22 is likely to be increased, and the detachment of the waist elastic member 23 from the split welded portion pair 51a can be further suppressed.

[0133] Furthermore, the left-right center of the first interval S1 can be offset from the left-right center of the third interval S3. By configuring in this way, in the area where the first interval S1 and the third interval S3 do not overlap in the left-right direction, Figure 8C As shown in the figure, a part of the waist elastic member 23 faces the welded portion (e.g., the sixth welded portion 506) on one side (e.g., the upper side) in the vertical direction, and faces the non-welded portion 52 on the opposite side (e.g., the lower side). Therefore, the waist elastic member 23 receives a force toward the center side (lower side) in the vertical direction from the welded portion (506), and also receives a force toward the center side (upper side) in the vertical direction from the fibers densely packed and overflowing in the non-welded portion 52. Therefore, the fibers of the sheets 21 and 22 are easily entangled with the waist elastic member 23, and the detachment of the waist elastic member 23 from the split welded portion pair 51a can be further suppressed.

[0134] In addition, if Fig. 6A As shown in the figure, the weld 50 arranged with a gap from the first weld 501 in the vertical direction is called the eighth weld 508, and the weld 50 arranged with a gap from the second weld 502 in the vertical direction is called the ninth weld 509. The eighth weld 508 is positioned offset from the first weld 501 or the eighth weld 508 adjacent in the vertical direction in the left-right direction, and the ninth weld 509 is positioned offset from the second weld 502 or the ninth weld 509 adjacent in the vertical direction in the left-right direction.

[0135] When the abdominal waistline portion 20 is stretched in the horizontal direction, the weld pair interval D1 may be greater than the horizontal length Lb of the interval between the eighth weld 508 and the ninth weld 509 adjacent to each other in the horizontal direction (D1>Lb).

[0136] In this way, by arranging the welded parts (508, 509) arranged in the vertical direction in a staggered manner in the horizontal direction, the part of the waist elastic member 23 located in the non-welded part 52 overlaps not only the welded parts 50 sandwiching the waist elastic member 23 in the horizontal direction, but also overlaps the welded parts (508, 509) arranged in the vertical direction, and is also easily affected by the welded parts (508, 509). For example, the dense fibers of the non-welded part 52 are pushed toward the waist elastic member 23 side by the welded parts (508, 509). Therefore, in the non-welded part 52, the fibers are easily entangled with the waist elastic member 23, and the detachment of the waist elastic member 23 from the split welded part pair 51a can be further suppressed.

[0137] However, it is not limited to the above configuration, and it is also possible to Fig. 9B As shown, the welded portions 50 adjacent to each other in the vertical direction are not offset in the horizontal direction, and the welded portions 50 are arranged linearly in the vertical direction.

[0138] In addition, the pair of sheets 21 and 22 sandwiching the waist elastic member 23 may have compressed portions 60 and 61 (embossed pattern) compressed in the thickness direction on the individual sheets. In the compressed portions 60 and 61, the fibers constituting the sheets 21 and 22 are tightly entangled, and few fibers can move freely.

[0139] Therefore, when a pair of sheets 21, 22 respectively have a plurality of compression portions 60, 61, the following configuration may be adopted. Fig.11 As shown in FIG. 1 , when the ventral waistline portion 20 in a state of being stretched in the left-right direction is viewed from above in the thickness direction, at least a portion of the plurality of compressed portions 60 of one sheet (e.g., the skin side sheet 21) may have an area that does not overlap with the compressed portion 61 of the other sheet (e.g., the non-skin side sheet 22). That is, as long as a portion or all of the plurality of compressed portions 60 of the skin side sheet 21 are staggered with the compressed portion 61 of the non-skin side sheet 22. The two compressed portions 60, 61 may overlap partially or may be completely staggered.

[0140] By configuring in this way, even if the compressed portion 60 of one sheet (e.g., the skin side sheet 21) is positioned at the non-welded portion 52, the probability that the compressed portion 61 of the other sheet (e.g., the non-skin side sheet 22) is not positioned is increased. Therefore, the waist elastic member 23 can be entangled with the uncompressed fibers of at least one sheet at the non-welded portion 52. Therefore, the waist elastic member 23 can be more reliably prevented from detaching from the split welded portion pair 51a.

[0141] In addition, when at least one of the pair of sheets 21 and 22 has a plurality of compressed portions 60 and 61, the following configuration may be adopted. When the ventral waistline portion 20 in a state of being stretched in the left-right direction is viewed from above in the thickness direction, it is preferred that: Figure 7 The first interval S1 of the first pair of divided and fused portions 51a1 shown has a region that does not overlap with the compressed portions 60 and 61 included in at least one of the sheets.

[0142] With this configuration, the non-welded portion 52 does not overlap the compressed portions 60, 61 at all, and the uncompressed free fibers are located in the non-welded portion 52. Therefore, the fibers of the sheets 21, 22 are easily entangled with the waist elastic member 23, and the waist elastic member 23 can be prevented from being separated from the split welded portion pair 51a.

[0143] In addition, when at least one of the pair of sheets 21 and 22 has a plurality of compressed portions 60 and 61, when the abdominal waistline portion 20 is stretched in the left-right direction, Figure 7The length Lb of the first interval S1 of the first split welding portion pair 51a1 in the left-right direction may be less than the maximum value E1 of the interval between the compression portions 60 and 61 adjacent to each other in the left-right direction (Lb≤E1). In addition, the interval between the compression portions 60 and 61 adjacent to each other in the left-right direction refers to the interval between the compression portions 60 and 61 adjacent to each other in the left-right direction among the compression portions 60 and 61 provided in the same sheet (21 or 22).

[0144] By configuring in this way, the non-welded portion 52 is easily accommodated between the compression portions 60 and 61 adjacent to each other in the left-right direction, and the free fibers that are not compressed are easily positioned in the non-welded portion 52. Therefore, the fibers of the sheets 21 and 22 are easily wound around the waist elastic member 23, and the waist elastic member 23 can be prevented from being separated from the split welded portion pair 51a.

[0145] In addition, the length Lb of the first interval S1 in the left-right direction may be greater than the maximum value E2 of the length of the compressed portions 60 and 61 in the left-right direction (Lb>E2). With such a configuration, even if the compressed portions 60 and 61 are positioned in the non-welded portion 52, an area that does not overlap with the compressed portions 60 and 61 is formed in the non-welded portion 52. Therefore, the fibers of the sheets 21 and 22 are easily entangled with the waist elastic member 23, and the waist elastic member 23 can be prevented from being separated from the split welded portion pair 51a.

[0146] However, the present invention is not limited to the above-mentioned structure. For example, the sheets 21 and 22 may not have the compression parts 60 and 61. Fig.11 In the figure, the elliptical compression parts 60, 61 are arranged at equal intervals in the left-right direction and the up-down direction, and the shape, number, and arrangement of the compression parts 60, 61 are not particularly limited. For example, compression parts 60, 61 of different shapes may be provided on the skin side sheet 21 and the non-skin side sheet 22.

[0147] In addition, the first interval S1 of the first disconnected and welded portion pair 51a1 may be configured as follows. Fig. 8A As shown in FIG. 1 , the length of at least one of the pair of sheets 21 and 22 sandwiching the waist elastic member 23 is twice the thickness h of the sheet as the second length 2h. At this time, when the ventral waistline portion 20 is stretched in the left-right direction, the left-right length Lb of the first interval S1 is preferably greater than the second length 2h (Lb ≥ 2h).

[0148] By configuring in this way, it is possible to prevent the first interval S1 from being too small and the non-welded portion 52 from shrinking in the left-right direction. Figure 8BAs shown in the figure, the sheets 21, 22 of the non-welded portion 52 are convexly bent toward the outside in the thickness direction and are sandwiched between the welded portions (501, 502), and the fiber density of the sheets 21, 22 becomes high. Therefore, the fibers of the sheets 21, 22 are easily entangled with the waist elastic member 23, and the waist elastic member 23 can be prevented from being separated from the split welded portion pair 51a.

[0149] The thickness of the sheets 21 and 22 can be measured by a known method. For example, in the separation welding portion pair 51a, the sheets 21 and 22 are cut in the left-right direction between the welding portions arranged in the vertical direction (for example, between the welding portions 501 and 502 and the welding portions 506 and 507). Fig. 8A The measurement is performed by observing the cross-section with a scanning electron microscope (for example, HITACHI FlexSEM 1000 or an equivalent device) in a state in which the cross-section is extended in the left-right direction as shown.

[0150] Fig. 12A as well as Fig. 12B It is an explanatory diagram of the waist elastic member 23.

[0151] like Fig. 12A As shown in the figure, the waist elastic member 23 is preferably a linear elastic member composed of a plurality of elastic fibers 23A. With such a configuration, even if a part of the elastic fibers 23A are disconnected during the process of forming the side joint portion SS, the remaining elastic fibers 23A are connected, thereby preventing the waist elastic member 23 from being cut. Therefore, it is possible to suppress the waist elastic member 23 from being separated from the welded portion pair 51, and ensure the elasticity of the ventral waist portion 20.

[0152] In addition, since the elastic fibers 23A are composed of a plurality of elastic fibers 23A, it is easy to form gaps S between the elastic fibers 23A. Therefore, even if the waist elastic member 23 is compressed in the process of forming the side joints SS (welded portions, etc.), the gaps S can be compressed to form a relief amount (not cut by the convex pattern forming the side joints SS), and thus the waist elastic member 23 can be prevented from being cut.

[0153] In addition, by being composed of a plurality of elastic fibers 23A, the thickness of the waist elastic member 23 is easily different locally according to the collection pattern of the elastic fibers 23A. Therefore, it is preferred that the elastic member 23 has a large diameter portion (first outer diameter portion) 23B having an outer diameter of the first outer diameter d23B and a small diameter portion (second outer diameter portion) 23C having an outer diameter d23C smaller than the first outer diameter d23B.

[0154] With such a configuration, when the large diameter portion 23B of the elastic member 23 is positioned between the pair of split welds 51a, the large diameter portion 23B is easily subjected to the force of the fibers that overflow due to the contraction of the non-welded portion 52, and the fibers are easily entangled. In addition, the force to be amplified by the large diameter portion 23B is strongly applied to the welded portion 50, and the large diameter portion 23B is tightly sandwiched between the welded portions 50. Therefore, the waist elastic member 23 can be further suppressed from being separated from the pair of split welds 51a.

[0155] In addition, it is preferable that the waist elastic member 23 is arranged in a twisted state between the pair of sheets 21 and 22. With such a configuration, when the waist elastic member 23 contracts, the twisted pitch of the waist elastic member 23 becomes smaller, and the fibers of the sheets 21 and 22 are easily entangled with the twisted portion of the waist elastic member 23 in the non-welded portion 52. Therefore, it is possible to further suppress the waist elastic member 23 from being separated from the pair of split welded portions 51a.

[0156] Whether the waist elastic members 23 are twisted can be checked visually, for example, by separating the pair of sheets 21 and 22 constituting the abdominal waist portion 20 so that the waist elastic members 23 are exposed.

[0157] In addition, the first disconnected welded portion pair 51a1 is adjacent to the second disconnected welded portion pair 51a2 at one side in the left-right direction with a relatively large welded portion pair interval D1 therebetween. Fig. 9C As shown in FIG. 1 , the welded portion pair 51a3 (third welded portion pair) may be adjacent to the welded portion pair 51a3 (third welded portion pair) at a relatively large interval (D1) on the other side in the left-right direction. That is, preferably, the length D1 in the left-right direction from the end of the first split welded portion pair 51a1 on the other side in the left-right direction to the end of the welded portion pair 51a3 on one side in the left-right direction is greater than the length Lb of the first interval S1 in the left-right direction (D1>Lb).

[0158] By configuring in this way, it is possible to prevent the welded portion pairs 51 from being densely arranged in the left-right direction, thereby ensuring the flexibility of the abdominal waistline portion 20. Fig. 9C In this case, the first weld pair 51a from the side joint SS is a disconnected weld pair 51a (first weld pair), and the conventional weld pair 51b can also be used. Fig. 9C As shown, on the outside in the left and right directions ( Fig. 9C The adjacent welded portion pair 51a3 (third welded portion pair) may also be located at the side joint portion SS. Figure 7As shown in the figure, when the first disconnected and welded portion pair 51a1 is positioned near the side joint portion SS, there may be no outer side ( Figure 7 The second second disconnected weld portion pair 51a2 from the side joint portion SS may also correspond to the first weld portion pair.

[0159] In addition, as described above, when the side joints SS are formed or when the side joints SS are held and pulled, the waist elastic member 23 is easily cut. Therefore, near the side joints SS, the waist elastic member 23 is easily separated from the welded portion pair 51. Therefore, it is preferable that Figure 7 As shown, when the ventral waistline portion 20 is extended in the left-right direction, the area of ​​the weld pair interval D1 is entered from the end SSa on the inner side in the left-right direction of the side joint portion SS toward the inner side in the left-right direction, and at least a portion of the disconnected weld pair 51a (the first disconnected weld pair 51a1) is positioned.

[0160] By configuring in this way, the welded portion pair 51 closest to the side joint SS is easily formed into the split welded portion 51a. Therefore, even if the waist elastic member 23 is cut at the side joint SS, the split welded portion pair 51a near the side joint SS can prevent the waist elastic member 23 from being separated. Therefore, the elasticity can be maintained over a wide range in the left-right direction of the abdominal waist portion 20.

[0161] Furthermore, if Figure 4 As shown in FIG. 1 , by arranging a plurality of (here, four) disconnected welded portion rows Ra in the left-right direction near the side joint SS, the waist elastic member 23 can be more reliably prevented from detaching from the disconnected welded portion pair 51a near the side joint SS. However, the present invention is not limited to the above-mentioned configuration, and the disconnected welded portion pair 51a may be positioned at a position farther from the inner side end SSa of the side joint SS than the welded portion pair interval D1, or the welded portion pair 51 closest to the side joint SS may be a normal welded portion pair 51b.

[0162] In addition, if Figure 4As shown in the figure, the waist elastic member 23D overlapping the absorbent body 10 may also have a discontinuous portion SB in which the waist elastic member 23D is cut and discontinuous, and a continuous portion SA located on the outside of the left-right direction compared to the discontinuous portion SB in the central part of the diaper 1 in the left-right direction. In the area corresponding to the discontinuous portion SB, the elasticity is basically not shown, and the elastic force of the waist elastic member 23 per unit width in the up-down direction is reduced compared to the area corresponding to the continuous portion SA. Therefore, the absorbent body 10 can be suppressed from shrinking due to the waist elastic member 23, the flatness of the absorbent body 10 (especially the absorbent core 11) can be ensured, and the close fit relative to the wearer is improved. In addition, when the absorbent body 10 is provided with a pattern (not shown) that can be recognized from the non-skin side, the visibility of the pattern is improved.

[0163] If the waist elastic member 23 is cut during the manufacturing process of the diaper 1, the waist elastic member 23 shrinks and its diameter increases, and is sandwiched by the welded portion pair 51 on the way. Therefore, when the ventral waist portion 20 is stretched, the cut ends of the stretched waist elastic member 23 are held by the welded portion pair 51, and the stretchability of the continuous portion SA can be ensured. In addition, when the waist elastic member 23 is cut at multiple locations, the waist elastic member 23D (not shown) that does not show stretchability is located at the discontinuous portion SB.

[0164] Furthermore, a first disconnected and welded portion pair 51a1 ( Figure 7 ) the same split welding portion pair 51a (first welding portion pair). Figure 4 As shown in FIG. 1 , a split welded portion row Ra is provided near the side end of the absorbent body 10. Thus, the split welded portion pair 51a can sandwich the end portion of the continuous portion SA of the waist elastic member 23D in the left-right direction. With such a configuration, the fibers of the non-welded portion 52 are easily wound around the split ends of the waist elastic member 23D, and the waist elastic member 23D can be prevented from being separated from the split welded portion pair 51a. Therefore, the elasticity of the ventral waist portion 20 can be ensured.

[0165] Fig.13 This is an explanatory diagram of the split welded portion pair 51a provided in the side portion of the absorbent body 10 and in the vicinity of the side joint portion SS. Figure 7 The first split weld pair 51a1 (first weld pair) described above refers to the split weld pair 51a located in the middle portion in the left-right direction of the abdominal waistline portion 20 (diaper 1) as a fourth split weld pair (fourth weld pair).

[0166] The fourth pair of disconnected and welded portions 51a4 also has a plurality of welded portions 50 arranged at intervals in the left-right direction on the same side in the up-down direction with respect to the waist elastic member 23, similarly to the first pair of disconnected and welded portions 51a1. However, the length Lc in the left-right direction of the first pair of disconnected and welded portions 51a1 may be longer than the length Ld in the left-right direction of the fourth pair of disconnected and welded portions 51a4 (Lc>Ld).

[0167] The fact that the length Lc of the first split weld pair 51a in the left-right direction is long means that the length of the welded portions (501, 502) is long or the number of the non-welded portions 52 is large. Therefore, the waist elastic member 23 is less likely to be detached in the first split weld pair 51a1 than in the fourth split weld pair 51a4. Therefore, the waist elastic member 23 is easily cut in the side joint SS, and the first split weld pair 51a1 near the side joint SS can reliably suppress the waist elastic member 23 from detaching. On the other hand, in the left-right central portion of the ventral waist portion 20 where the waist elastic member 23 is less likely to be cut like in the side joint SS, the fourth split weld pair 51a4 having a short length can suppress the waist elastic member 23 from detaching, and the flexibility of the ventral waist portion 20 can be ensured. However, the present invention is not limited to the above-mentioned configuration, and the length of the split weld pair 51a in the left-right direction can be constant.

[0168] In the above, an embodiment in which the elastic sheet 40 is provided in the ventral waistline portion 20 is described. Therefore, the elastic sheet 40 is provided in the ventral waistline portion 20 in such a manner that the left-right direction of the elastic sheet 40 (the direction along which the elastic member is arranged) coincides with the left-right direction of the underpants-type diaper 1, and the up-down direction of the elastic sheet 40 (the direction orthogonal to the elastic member) coincides with the up-down direction of the underpants-type diaper 1.

[0169] In the above embodiment, both the ventral waistline portion 20 and the dorsal waistline portion 30 are formed of the elastic sheet 40, but only one of the waistline portions may be formed of the elastic sheet 40. In addition, the dorsal waistline portion 30 has an extension portion 30E extending downward from the side joint portion SS, and the extension portion 30E is provided. Figure 2 In contrast, when an elastic member is disposed along the left-right direction in the extension portion 30E, the extension portion 30E may be formed of the stretch sheet 40 .

[0170] ===Second Embodiment===

[0171] Fig.141 is a top view of a belt-type diaper 2 unfolded in the longitudinal direction. In the first embodiment, an example is given of a case where the elastic sheet 40 is provided on the waist circumference 20, 30 of the underpants-type diaper 1 for adults. However, the absorbent article having the elastic sheet 40 is not limited thereto, and may be, for example, underpants-type disposable diapers for infants and young children, pant-type sanitary napkins, belt-type disposable diapers, absorbent pads for light incontinence, sanitary napkins for menstruation, etc.

[0172] The tape diaper 2 has a pair of hook and loop fasteners 70 extending from the back side toward both outer sides in the left and right directions. The wearer holds the hook and loop fasteners 70 and stretches them along the waistline of the wearer to the ventral side, and fastens the hook and loop fasteners 70 to the ventral side of the tape diaper 2. Therefore, the hook and loop fasteners 70 are preferably formed of a stretch sheet 40. With such a structure, the wearer can easily pull the hook and loop fasteners 70.

[0173] In this case, the left-right direction of the stretch sheet 40 (the direction along which the elastic member 3 extends) coincides with the left-right direction (width direction) of the belt-type diaper 2, and the up-down direction of the stretch sheet 40 (the direction orthogonal to the elastic member 3) coincides with the up-down direction of the belt-type diaper 2 (the length direction of the absorbent core 11).

[0174] Furthermore, it is preferred that the split welding portion row Ra is provided at both ends of the hook and loop fastener portion 70 (elastic member 3) in the left and right directions. By such a configuration, even if the hook and loop fastener portion 70 is strongly pulled when the belt-type diaper 2 is worn, the elastic member 3 can be suppressed from being separated from the split welding portion pair 51a. On the other hand, a conventional welding portion row Rb can be provided at the central portion in the left and right directions of the hook and loop fastener 70. By such a configuration, the softness of the hook and loop fastener 70 can be ensured.

[0175] In addition, although not shown, an elastic member may be arranged in a portion other than the hook and loop fastener 70, for example, in the central portion in the left and right direction of the back portion, and the elastic member is sandwiched by the split welding portion pair 51a. Fig.13 Similarly, the length of the split welded portion pair 51a in the left-right direction of the hook and loop fastener 70 (the left-right end of the tape-type diaper 2) is longer than the split welded portion pair 51a in the left-right direction of the dorsal portion. By configuring in this way, the elastic member 3 can be further prevented from detaching from the split welded portion pair 51a in the hook and loop fastener 70 that is strongly pulled.

[0176] In addition, the elastic sheet 40 is not limited to being applied to the waist circumference 20, 30 of the underpants-type diaper 1 or the hook and loop fastener 70 of the belt-type diaper 2, but can also be applied to other parts of the absorbent article, such as the elastic part of the leg circumference, etc. In addition, the elastic sheet 40 can also be applied to products other than absorbent articles (such as cleaning components or masks, etc.).

[0177] The above embodiments are intended to facilitate understanding of the present invention and are not intended to be limiting of the present invention. The present invention may be modified and improved without departing from its concept, and the present invention also includes equivalent configurations.

[0178] Description of Reference Numerals

[0179] 1. Diapers (underwear absorbent articles),

[0180] 2 belt type diaper, 3 elastic member,

[0181] 10 absorbent body, 11 absorbent core, 12 top sheet,

[0182] 13 bottom sheet, 14 outer sheet, 15 leg elastic member,

[0183] 16 leak-proof wall elastic member,

[0184] 20 ventral waist circumference (waist circumference),

[0185] 21 skin side sheet (sheet), 22 non-skin side sheet (sheet),

[0186] 23 waist elastic member (elastic member, first elastic member),

[0187] 23A elastic fiber,

[0188] 30 back waist (waist), 30E extension,

[0189] 31 skin side sheet (sheet), 32 non-skin side sheet (sheet),

[0190] 33 waist elastic member (elastic member),

[0191] 40 stretchable sheets,

[0192] SS side joint,

[0193] 50 welding part,

[0194] 501 first welding part, 502 second welding part,

[0195] S1 Space 1,

[0196] 51 welded parts,

[0197] 51a Separate the welded part pair,

[0198] 51a1: first disconnected welded portion pair (first welded portion pair),

[0199] 51a2: second disconnected welded portion pair (second welded portion pair),

[0200] 51b Conventional welding section pair,

[0201] 52 non-welded portion,

[0202] 60, 61 compression part,

[0203] 70 Velcro.

Claims

1. A stretchable sheet having a vertical direction and a horizontal direction intersecting each other, wherein a plurality of elastic members capable of stretching in the horizontal direction are arranged at intervals in the vertical direction between a pair of sheets joined by a plurality of welded portions, wherein: The plurality of welded portions include a plurality of welded portion pairs located on both sides of the elastic member in the up-down direction. Each of the elastic members is sandwiched between the pair of welded portions in a state of being contracted in the left-right direction, so that the position of each elastic member in the left-right direction relative to the pair of sheets is restricted. The plurality of welded portion pairs include: a first welded portion pair; and a second welded portion pair located next to one side of the first welded portion pair in the left-right direction. The first welding portion pair and the second welding portion pair both sandwich the first elastic member. The first welding portion pair includes a first welding portion and a second welding portion located at a first interval in the left-right direction on the same side in the up-down direction based on the first elastic member, In the state extended in the left-right direction, the length in the left-right direction from the end of the first welding portion pair on one side in the left-right direction to the end of the second welding portion pair on the other side in the left-right direction, i.e., the first length, is greater than the length in the left-right direction of the first interval.

2. The stretchable sheet according to claim 1, wherein In the state extended in the left-right direction, the length of the first interval in the left-right direction is less than or equal to the length of the first weld in the left-right direction and less than or equal to the length of the second weld in the left-right direction.

3. The stretchable sheet according to claim 1 or 2, wherein In the state of being extended in the left-right direction, the first length is greater than the length of the first welded portion pair in the left-right direction.

4. The stretchable sheet according to claim 1 or 2, wherein The second welded portion pair includes a third welded portion and a fourth welded portion located at a second interval in the left-right direction on the same side in the up-down direction based on the first elastic member, In the state extended in the left-right direction, the first length is greater than the length of the second interval in the left-right direction.

5. The stretchable sheet according to claim 1 or 2, wherein The first weld portion pair has one or more fifth weld portions arranged in the left-right direction at intervals from the first weld portion and the second weld portion on the same side in the up-down direction based on the first elastic member, In the state extended in the left-right direction, the first length is greater than the left-right length of the interval between the fifth weld and the first weld or the fifth weld adjacent to the fifth weld in the left-right direction.

6. The stretchable sheet according to claim 5, wherein In the state extended in the left-right direction, the length in the left-right direction of the interval between the fifth weld and the first weld adjacent to the fifth weld or the fifth weld adjacent to the fifth weld in the left-right direction is less than the length in the left-right direction of each of the first weld, the second weld and the fifth weld.

7. The stretchable sheet according to claim 1 or 2, wherein The first welded portion pair includes a sixth welded portion and a seventh welded portion located at a third interval in the left-right direction on the side opposite to the same side in the up-down direction based on the first elastic member, In the state extended in the left-right direction, the first length is greater than the length of the third interval in the left-right direction.

8. The stretchable sheet according to claim 7, wherein In the state of being extended in the left-right direction, The first interval and the third interval have an overlapping area in the left-right direction. The center of the first interval in the left-right direction and the center of the third interval in the left-right direction are offset in the left-right direction.

9. The stretchable sheet according to claim 8, wherein The stretch sheet has a plurality of eighth welded portions arranged at intervals from the first welded portion in the up-down direction. The stretch sheet has a ninth weld portion arranged at a distance from the second weld portion in the up-down direction. The eighth weld is positioned in the left-right direction so as to be offset from the first weld or the eighth weld adjacent to the up-down direction. The ninth weld is positioned in the left-right direction so as to be offset from the second weld or the ninth weld adjacent to the upper-lower direction. In a state extended in the left-right direction, the first length is greater than a length in the left-right direction of a distance between the eighth weld portion and the ninth weld portion adjacent to each other in the left-right direction.

10. The stretchable sheet according to claim 1 or 2, wherein The pair of sheets each have a plurality of compressed portions compressed in the thickness direction of the sheet. When the stretchable sheet stretched in the left-right direction is viewed from above, the stretchable sheet has a region where at least a part of the plurality of compressed portions of one sheet of the pair of sheets does not overlap with the compressed portions of the other sheet.

11. The stretchable sheet according to claim 1 or 2, wherein At least one of the pair of sheets has a plurality of compressed portions compressed in the thickness direction of the sheet. The stretchable sheet in a state of being stretched in the left-right direction has a region where the first space does not overlap with the compressed portion when viewed from above.

12. The stretchable sheet according to claim 1 or 2, wherein At least one of the pair of sheets has a plurality of compressed portions compressed in the thickness direction of the sheet. In a state extended in the left-right direction, a length of the first interval in the left-right direction is less than or equal to a maximum value in the left-right direction of intervals between adjacent compression portions in the left-right direction.

13. The stretchable sheet according to claim 1 or 2, wherein When a length twice the thickness of at least one of the pair of sheets is defined as a second length, a length of the first interval in the left-right direction in a state stretched in the left-right direction is equal to or longer than the second length.

14. The stretchable sheet according to claim 1 or 2, wherein The first elastic member is disposed between the pair of sheets in a twisted state.

15. The stretchable sheet according to claim 1 or 2, wherein The first elastic member is a linear elastic member formed by a collection of a plurality of elastic fibers, and includes a first outer diameter portion having an outer diameter equal to a first outer diameter and a second outer diameter portion having an outer diameter smaller than the first outer diameter.

16. The stretchable sheet according to claim 1 or 2, wherein The plurality of welded portion pairs include a third welded portion pair located next to the first welded portion pair on the other side in the left-right direction and sandwiching the first elastic member. In the state extended in the left-right direction, the length in the left-right direction from the end of the other side of the left-right direction of the first welding portion pair to the end of the one side of the left-right direction of the third welding portion pair is greater than the length in the left-right direction of the first interval.

17. An absorbent article comprising the stretchable sheet according to claim 1 or 2, characterized in that: The absorbent article has an up-down direction and a left-right direction that intersect each other. The up-down direction of the stretch sheet is along the up-down direction of the absorbent article. The left-right direction of the stretch sheet is along the left-right direction of the absorbent article. The first elastic member comprises: a discontinuous portion in which the first elastic member is cut and discontinuously formed at a central portion in the left-right direction of the absorbent article; and a continuous portion located outside the discontinuous portion in the left-right direction. The first welded portion sandwiches the end portions of the continuous portion on the center side in the left-right direction.

18. An absorbent article comprising the stretchable sheet according to claim 1 or 2, characterized in that: The absorbent article has an up-down direction and a left-right direction that intersect each other. The up-down direction of the stretch sheet is along the up-down direction of the absorbent article. The left-right direction of the stretch sheet is along the left-right direction of the absorbent article. The stretch sheet has a fourth welded portion pair sandwiching the first elastic member. The fourth welding portion pair includes a plurality of welding portions arranged at intervals in the left-right direction on the same side in the up-down direction based on the first elastic member, The first welded portion is located at the end portion in the left-right direction of the absorbent article. The fourth welded portion is located at the center of the absorbent article in the left-right direction. The length of the first pair of welded portions in the left-right direction is greater than the length of the fourth pair of welded portions in the left-right direction.

19. A pants-type absorbent article comprising the stretchable sheet according to claim 1 or 2, characterized in that: The above-mentioned underwear type absorbent article has a vertical direction and a horizontal direction that intersect each other, and has an absorbent body and a pair of waist parts. The elastic sheet is provided on at least one of the pair of waist portions. The up-down direction of the stretch sheet is along the up-down direction of the underwear-type absorbent article. The left-right direction of the stretch sheet is along the left-right direction of the underwear-type absorbent article. The pair of waist parts are joined by a pair of side joint parts at both sides in the left-right direction. In the state extended in the left-right direction, at least a portion of the first pair of welded portions is located in a region extending from an inner end of the side joint portion in the left-right direction toward an inner side in the left-right direction by the first length.

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