CN111405887B

CN111405887B - Pants-type absorbent article

Info

Publication number: CN111405887B
Application number: CN201980005870.9A
Authority: CN
Inventors: 恩田蓝子; 浦山优辅; 大西玲子
Original assignee: Kao Corp
Current assignee: Kao Corp
Priority date: 2018-04-02
Filing date: 2019-03-06
Publication date: 2021-10-22
Anticipated expiration: 2039-03-06
Also published as: GB2585293A; WO2019193906A1; GB202013122D0; GB2585293B; DE112019000549T5; RU2757895C1; CN111405887A

Abstract

A pants-type absorbent article according to one embodiment of the present invention has an absorbent body, a waist portion, and a crotch portion. The absorber is located at the crotch part. The waist portion has a ventral portion and a dorsal portion located at a waist portion. The crotch portion is located between the front side portion and the back side portion, and holds the absorbent body together with the front side portion and the back side portion. At least one of the ventral portion and the dorsal portion includes a stretch panel comprising: a first region; and a second region located on an upper side of the first region in a vertical direction orthogonal to a circumferential direction of the waist portion. The stretchable sheet includes an elastic resin and a nonwoven fabric layer containing the elastic resin, and the circumferential contraction stresses are different from each other in the first region and the second region, and the circumferential dimensions in a natural state are equal in the first region and the second region.

Description

Pants-type absorbent article

Technical Field

The present invention relates to a pants-type absorbent article such as a disposable diaper.

Background

A pants-type absorbent article such as a diaper including an absorbent body and an outer cover for fixing the absorbent body has an absorbent article in which a stretchable nonwoven fabric is used in a waist portion of the outer cover for the purpose of improving fit to a waist portion of a wearer (for example, see patent document 1).

Documents of the prior art

Patent document

Patent document 1: japanese patent laid-open No. 2008-106378

Disclosure of Invention

One embodiment of the present invention provides a pants-type absorbent article having an absorber, a waist portion, and a crotch portion.

The absorber is located at the crotch part.

The waist portion has a ventral portion and a dorsal portion located at a waist portion.

The crotch portion is located between the front side portion and the back side portion, and holds the absorbent body together with the front side portion and the back side portion.

At least one of the ventral portion and the dorsal portion includes a stretch panel comprising: a first region; and a second region located on an upper side of the first region in a vertical direction orthogonal to a circumferential direction of the waist portion.

The stretchable sheet includes an elastic resin and a nonwoven fabric layer containing the elastic resin, and the circumferential contraction stresses are different from each other in the first region and the second region, and the circumferential dimensions in a natural state are equal in the first region and the second region.

One embodiment of the present invention provides a stretch panel having a plurality of elastic threads and two layers of nonwoven fabric.

The elastic wire is capable of stretching in a first direction.

The two nonwoven fabrics are arranged to face each other with the elastic threads interposed therebetween.

The nonwoven fabric has: a plurality of projections arranged at intervals along the first direction and extending in a second direction orthogonal to the first direction; and a flat portion disposed between the convex portions adjacent to each other among the plurality of convex portions, and extending in the second direction.

The convex portion has a first convex portion and a second convex portion different in height from each other in the second direction, and the height of the second convex portion is higher than the height of the first convex portion.

Drawings

Fig. 1 is a perspective view of a disposable diaper according to first to sixth embodiments of the present invention.

Fig. 2 is a schematic exploded perspective view of the disposable diaper of the first embodiment in an unfolded state.

Fig. 3 is a plan view showing a developed state of the disposable diaper of the first embodiment, as viewed from the inside.

Fig. 4 is a plan view showing a developed state of the outer cover of the disposable diaper according to the first embodiment, and is a view for explaining a pattern of an adhesive layer of the outer cover.

Fig. 5 is an expanded schematic perspective view of the region surrounded by the ellipse V of fig. 3, showing a natural state in which the outer package is expanded to be opened, and showing a state in which the folded portion is expanded.

Fig. 6 is a sectional view taken along line VI-VI of fig. 3.

Fig. 7 (a) is a plan view showing the first sheet 11 in an enlarged manner in a region surrounded by an ellipse VIIA in fig. 4, schematically showing the structure of the first sheet 11, and fig. 7 (B) is a cross-sectional view taken along line VIIB-VIIB in fig. 7 (a).

Fig. 8 is a plan view showing a developed state of the disposable diaper according to the second embodiment, as viewed from the inside.

Fig. 9 is a plan view showing a developed state of an outer cover of the disposable diaper according to the third embodiment, and is a view for explaining a pattern of an adhesive layer of the outer cover.

Fig. 10 is a plan view showing a developed state of an outer cover of the disposable diaper according to the fourth embodiment, and is a view for explaining a pattern of an adhesive layer of the outer cover.

Fig. 11 is a plan view showing a developed state of an outer cover of the disposable diaper according to the fifth embodiment, and is a view for explaining a pattern of an adhesive layer of the outer cover.

Fig. 12 is a plan view showing a developed state of an outer cover of the disposable diaper according to the sixth embodiment, and is a view for explaining a pattern of an adhesive layer of the outer cover.

Fig. 13 is an enlarged plan view of another first sheet constituting the exterior body according to the seventh embodiment, and is a view schematically showing the structure of the first sheet.

Fig. 14 is a perspective view schematically showing a natural state of the stretch panel according to the eighth embodiment of the present invention.

Fig. 15 (a) is a sectional view schematically showing a state of being cut along the line IIA-IIA of the stretchable sheet of fig. 14 in the stretching direction, and fig. 15 (B) is a sectional view schematically showing a state of being cut along the line IIB-IIB of the stretchable sheet of fig. 14.

Fig. 16 is a perspective view schematically showing a state in which the stretch panel of fig. 14 is linearly formed so that the undulation of the elastic yarn is straightly extended without extending the elastic yarn, and the boundary surface between the first nonwoven fabric and the second nonwoven fabric is expanded in a planar shape.

Fig. 17 is a schematic plan view of the stretch panel of fig. 14, and is a plan view of a state in which a boundary surface between the first nonwoven fabric and the second nonwoven fabric is expanded in a planar shape, as in fig. 16.

Fig. 18 is a partially enlarged cross-sectional view schematically showing the vicinity of the convex portion in the natural state and the extended state of the stretchable panel of fig. 16, wherein fig. 18 (a) shows the natural state, and fig. 18 (B) shows the stretchable panel extended in the stretching direction (Y-axis direction).

Fig. 19 is a schematic plan view showing a state in which the stretch panel of fig. 14 is extended in the stretching direction.

Fig. 20 (a) is a cross-sectional view schematically showing a state corresponding to fig. 16, and fig. 20 (B) is a cross-sectional view schematically showing a state corresponding to fig. 14 in which the wave shape of the elastic yarn of the stretch panel and the boundary surface between the first nonwoven fabric and the second nonwoven fabric is maintained.

Fig. 21 is a schematic enlarged plan view of a nonwoven fabric showing the position of a heat-fusion bonded portion constituting a part of the stretch panel of fig. 14.

Fig. 22 is a cross-sectional view schematically showing a stretching apparatus according to an embodiment used for manufacturing the stretch panel.

Fig. 23 (a) is a perspective view of a cogged stretching roller used in the stretching device of fig. 22, and fig. 23 (B) is a perspective view of teeth provided on the cogged stretching roller.

Fig. 24 is a view schematically showing a case where the convex portion of the stretch panel is formed by roll drawing, and in each of (a), (B), and (C) of fig. 24, the upper portion shows a partially enlarged view of the drawing device of fig. 22 in roll drawing, and the lower portion shows a cross-sectional view in which the laminate or the stretch panel in the processing shown in the upper portion is stretched in a planar state so as not to stretch the elastic yarn.

Fig. 25 is a perspective view of a disposable diaper using the stretch panel.

Fig. 26 is a schematic exploded perspective view of the disposable diaper of fig. 25 in an unfolded state.

Fig. 27 is a plan view showing a developed state of the outer package of the disposable diaper of fig. 25.

Fig. 28 is a partially enlarged sectional view of the stretch panel of the ninth embodiment, schematically showing a state corresponding to fig. 16.

Fig. 29 is a schematic exploded perspective view of a disposable diaper according to another embodiment in an unfolded state.

Detailed Description

Among pants-type absorbent articles, an absorbent article that is close to the appearance and feel of pants of underwear is desired. The present invention relates to a pants-type absorbent article that maintains fit and exhibits an appearance and a texture close to pants (cloths) of underwear. The present invention also relates to a stretchable sheet suitable for use in pants-type absorbent articles or the like for which fitness to the waist is desired.

Embodiments of the present invention will be described below with reference to the drawings.

In the drawings, an X-axis, a Y-axis, and a Z-axis orthogonal to each other are shown as necessary.

< first embodiment >

[ integral Structure of Disposable diaper ]

A disposable diaper 1 according to a first embodiment of the present invention will be described with reference to fig. 1. The disposable diaper 1 is a pants-type absorbent article for collecting excrement from an infant as a wearer without leakage.

The disposable diaper 1 includes an outer package 8 and an absorber 9. The outer package 8 constitutes an outer package of the disposable diaper 1. The absorber 9 is held inside the outer package 8. That is, the outer cover 8 is disposed on the outer surface side of the absorbent body 9 opposite to the skin side of the wearer when worn. Hereinafter, the inner side of each structure indicates the skin side of the wearer when the disposable diaper is worn, and the outer side indicates the opposite side to the skin side of the wearer.

The outer package 8 is formed by a waist portion 16 and a crotch portion 17 formed continuously. The waist portion 16 forms a waist opening 7 and is disposed at the waist of the wearer. The waist portion 16 is formed of an extensible sheet that extends and contracts in the girth direction so as to be fitted to the waist portion of the wearer. In fig. 1, the crotch portion 17 is located below the waist portion 16 and is disposed in the crotch of the wearer.

The waist portion 16 has a front abdominal portion 16a disposed on the front side and a rear back portion 16b disposed on the rear side when worn. The front side portion 16a and the back side portion 16b are joined to each other by, for example, heat sealing, ultrasonic sealing, or the like at side seal portions 18 provided at both ends in the width direction orthogonal to the front-back direction. Thereby, the waist portion 16 is formed in a tubular shape, and the waist opening 7 is formed between the abdomen-side portion 16a and the back-side portion 16 b.

The crotch portion 17 is located between the stomach-side portion 16a and the back-side portion 16 b. The crotch portion 17 connects the front side portion 16a and the back side portion 16b so that a pair of leg openings 14 through which the legs of the wearer are inserted are formed on both sides in the width direction. The crotch portion 17 is provided with leg gathers 19 including rubber threads 19a disposed along the leg openings 14. The leg gathers 19 are attached to the legs of the wearer inserted through the leg openings 14 by the expansion and contraction of the rubber thread 19 a.

The disposable diaper 1 and the outer cover 8 shown in fig. 2 to 4 are in a state in which the side seal 18 is torn from the state shown in fig. 1 to separate the front side portion 16a and the back side portion 16b, and the outer cover 8 and the absorbent body 9 are stretched along the XY plane.

Fig. 3 shows a state in which the second sheet 12 constituting the exterior body 8 is positioned on the near side and the first sheet 11 is positioned on the deep side, and the absorbent body 9 is shown by a broken line for convenience. In fig. 3, the outer package 8 is shown in a stacked state, and therefore, the lower right corner of the back side portion 16b of the second sheet 12 and the adhesive layer 13 provided corresponding thereto are shown in the figure as being cut so that the first sheet 11 positioned on the deeper side can be seen. The same applies to fig. 8 described later.

In fig. 4, the first sheet 11 constituting the exterior body 8 is shown in a state of being positioned on the near side and the second sheet 12 is positioned on the deep side, and the adhesive layer 13 is shown by a solid line for convenience. Fig. 4 shows the outer package 8 in a stacked state, and therefore, the drawing shows the second sheet 12 positioned on the depth side by cutting the lower right corner portion of the first sheet 11 and the adhesive layer 13 provided corresponding thereto. The same applies to fig. 9 to 12 described later.

As shown in fig. 2, the exterior body 8 is composed of a composite sheet 10 in which a first sheet 11 and a second sheet 12 are bonded to each other with an adhesive layer 13. The first sheet 11 constituting the outer cover 8 is folded back inward at the opening peripheral edge 15 of the waist opening 7 of the disposable diaper 1. Fig. 3 shows a state where the folded portion 20 of the first sheet 11 is folded inward, and fig. 4 shows a state where the folded portion 20 is unfolded.

In the disposable diapers 1 shown in fig. 2 and 3 and the outer package 8 shown in fig. 4, the X-axis direction corresponds to the front-rear direction, the Y-axis direction corresponds to the width direction, and the Z-axis direction corresponds to the thickness direction. The circumferential direction of the waistline in the ventral portion 16a and the dorsal portion 16b of the waist portion 16 in fig. 1 corresponds to the width direction Y in fig. 3 and 4.

Hereinafter, the waist portion 16 may be described as being in the vertical direction. The vertical direction corresponds to the vertical direction of the disposable diaper 1 when the wearer wears the disposable diaper 1 in a standing state. The front-back direction is the same as the up-down direction. The disposable diaper 1 will be described below in the embodiment shown in fig. 2 to 4.

As shown in fig. 1 to 3, the absorbent body 9 is configured to be capable of collecting excrement and absorbing liquid contained in the excrement. The absorber 9 is formed in a band shape and disposed in a wide range from the crotch portion 17 of the outer package 8 to the abdomen-side portion 16a and the back-side portion 16b of the waist portion 16. Thus, in the disposable diaper 1, since the crotch region of the wearer is covered with the absorber 9 over a wide range, even if the wearer moves, the excrement is less likely to leak.

In addition, the absorption body 9 mainly absorbs liquid in the region where excrement is collected in the crotch portion 17. The liquid absorbed into the absorbent body 9 is absorbed into the waist portion 16 without staying in this region. That is, the absorbent body 9 can hold liquid over a wide range of the crotch portion 17 and the waist portion 16. Thus, the disposable diaper 1 can absorb a sufficient amount of liquid by the absorber 9.

As shown in fig. 2, the outer package 8 is composed of a composite sheet 10 which is an extensible sheet. The composite sheet 10 has: a first sheet 11 including a stretchable nonwoven fabric made of a nonwoven fabric layer containing an elastic resin; a second sheet 12 comprising a non-stretchable nonwoven fabric opposite to the first sheet 11; and an adhesive layer 13 for bonding the first sheet 11 and the second sheet 12. The first piece is a flexible piece, and the second piece is a non-flexible piece. Here, the stretch nonwoven fabric means a nonwoven fabric having a recovery rate (elongation recovery rate) of 70% or more when elongated by 100% at least in the same direction as the contraction direction. The stretch nonwoven fabric (first sheet) used in the present embodiment preferably has an elongation of 100% or more, and more preferably 150% or more. In the present embodiment, the second sheet 12 is provided so as to face the inside of the first sheet 11, and the first sheet 11 is positioned on the outer surface 8a side of the exterior body 8. Details of the

sheets

11 and 12 and the adhesive layer 13 constituting the exterior body 8 will be described later.

The waist portion 16 of the outer package 8 is stretchable in the circumferential direction of the waistline. As shown in fig. 3, the abdomen-side portion 16a (back-side portion 16b) of the waist portion 16 of the outer body 8, which requires stretchability in the girth direction, has a first region 31a (first region 31b), a second region 32a (second region 32b), and a third region 33a (third region 33b) which are different in the contraction stress in the girth direction. The first region 31a (first region 31b), the second region 32a (second region 32b), and the third region 33a (third region 33b) are equal in size in the circumferential direction of the waistline in the natural state (stress-released state). Hereinafter, the tensile load (cN) per unit length (1mm) when the sheet is stretched to 185% of the natural length in the circumferential direction and then contracted to 140% of the length is defined as the contraction stress of the sheet.

The first region 31 (second region 32, third region 33) includes: the first region 31a of the front side (the second region 32a of the front side, and the third region 33a of the front side) and the first region 31b of the back side (the second region 32b of the back side, and the third region 33b of the back side) are referred to as the first regions 31 (the second regions 32 and the third regions 33) when there is no need to distinguish between them.

In fig. 3 and 4, the expansion and contraction regions are represented by dot patterns, and the degree of the magnitude of the contraction stress in each region is represented by the density of the dot patterns. The higher the shrinkage stress, the higher the density of the dot pattern, and the lower the shrinkage stress, the lower the density. The same applies to the dot pattern of the drawings used in the description of other embodiments described below.

The first region 31, the second region 32, and the third region 33 are different from each other with respect to the shrinkage stress. Specifically, in the present embodiment, the first region 31 has the highest shrinkage stress, the third region 33 has the second highest shrinkage stress, and the second region 32 has the lowest shrinkage stress. That is, when the first to third regions 31 to 33 are elongated at the same elongation, the forces (shrinkage stresses) to be restored to the original state by shrinkage in the respective regions are different. Thus, when the waist portion 16 is stretched at the same elongation, tightening pressure different for each region acts on the wearer. In the present embodiment, the second region 32 and the third region 33 are located on the upper side of the first region 31 in the vertical direction orthogonal to the circumferential direction of the waistline. That is, the lower side contraction stress is higher than the upper side of the waist portion 16.

The third region 33 is located at the opening peripheral edge 15 which is an upper edge of the exterior body 8. The composite sheet 10 constituting the exterior body 8 is folded inward downward in the vertical direction to form a third region 33. The vertical length of the third region 33 is equal to or less than 1/2, which is about 1/3 in the present embodiment, of the vertical length of the second region 32.

Specifically, as shown in fig. 2, in the composite sheet 10, the first sheet 11 has portions extending from the second sheet 12 at both ends in the front-rear direction, and the extending portions are folded portions 20. The folded portion 20 is folded at a position corresponding to both front and rear end edges of the second sheet 12 as a folded position. This folded-back position corresponds to the position of the opening peripheral edge 15 when the disposable diaper 1 is used.

[ detailed Structure of the outer cover ]

Hereinafter, each structure of the exterior body 8 will be described in detail with reference to fig. 2 to 7. Fig. 5 and 6 each show a partial view of the back portion 16b, but the ventral portion 16a has the same configuration.

(first sheet)

The first sheet 11 is a single-layer stretch nonwoven fabric, i.e., a single-sheet stretch nonwoven fabric, which is continuously formed from the stomach-side portion 16a to the back-side portion 16b through the crotch portion 17.

As shown in fig. 2, 4, and 5, the first sheet 11 has extending portions extending from the second sheet 12 at both ends in the front-rear direction. The extended portion is a folded-back portion 20 folded inward. The folded portion of the folded back portion 20 becomes the third region 33. As shown in fig. 6, in the third region 33, two first sheets 11, one second sheet 12, and two adhesive layers 13 are stacked, and the first sheet 11 is provided in two layers.

As shown in fig. 4, the first sheet 11 of the waist portion 16 of the outer body 8 has a high contraction stress region P1 and a low contraction stress region P2, in which contraction stresses are different in the front-rear direction, in the expanded state in which the folded-back portion 20 is expanded. The high shrinkage stress region P1 and the low shrinkage stress region P2 have different shrinkage stresses. In the present embodiment, the low shrinkage stress region P2 has a lower shrinkage stress than the high shrinkage stress region P1. In addition, the width dimension of the low shrinkage stress region P2 is equal to the width dimension of the high shrinkage stress region P1.

The high shrinkage stress region P1 corresponds to the first region 31.

The low shrinkage stress region P2 corresponds to the second region 32 and the third region 33. In contrast to the low shrinkage stress regions P2 of the first sheet 11 being arranged in a single layer in the second region 32, the low shrinkage stress regions P2 of the first sheet 11 being arranged in a double layer in the third region 33. Therefore, the shrinkage stress of the third region 33 is higher than that of the second region 32.

As described above, the first sheet 11 of the exterior body 8 of the present embodiment has the high shrinkage stress region P1 and the low shrinkage stress region P2 in which the shrinkage stresses are different from each other in the front-rear direction in the state before the exterior body 8 is assembled.

As shown in fig. 7, the first sheet 11 is a stretch nonwoven fabric having a plurality of elastic threads 42 and a nonwoven fabric layer 41 containing the elastic threads 42. The first sheet 11 includes a nonwoven fabric layer 41 extending along the XY plane and elastic threads 42 as an elastic resin incorporated in the nonwoven fabric layer 41.

The nonwoven fabric layer 41 is formed of a nonwoven fabric made of fibers having low elasticity. The nonwoven fabric forming the nonwoven fabric layer 41 is not limited to a specific type, and may be selected from, for example, a hot air nonwoven fabric, a hot roll nonwoven fabric, a spunlace nonwoven fabric, a spunbond nonwoven fabric, a meltblown nonwoven fabric, and the like. The fibers constituting the nonwoven fabric layer 41 are not limited to specific types, and may be selected from chemical fibers such as polyethylene, polypropylene, polyester, and polyamide. The nonwoven fabric layer 41 may be formed of a composite fiber containing a plurality of types of chemical fibers. In addition, natural fibers such as cotton and silk may be blended with the fibers constituting the nonwoven fabric layer 41.

The elastic wire 42 is a linear elastic body extending in the Y-axis direction. The plurality of elastic threads 42 are arranged at equal intervals in the X-axis direction in the waist portion 16. The elastic wires 42 can be formed of an elastic material such as a thermoplastic elastomer or rubber. In particular, the elastic threads 42 are preferably formed of a thermoplastic elastomer which is easily fused to the fibers constituting the nonwoven fabric layer 41. As the thermoplastic elastomer forming the elastic yarn 42, for example, styrene-based elastomer, olefin-based elastomer, polyester-based elastomer, polyurethane-based elastomer, or the like can be used. In addition, the elastic wire 42 can also be formed by combining a plurality of thermoplastic elastomers. The elastic yarn 42 may be a core-sheath type or side-by-side type composite fiber.

In the first sheet 11, the stretchable and contractible portions 11a and the connecting portions 11b extending in the X-axis direction are alternately arranged along the Y-axis direction. In the first sheet 11, the grammage of the nonwoven fabric layer 41 of the stretchable part 11a is lower than the grammage of the nonwoven fabric layer 41 of the connecting part 11 b. Therefore, the expansion and contraction portion 11a is more easily deformed in the Y-axis direction than the connection portion 11 b. In the nonwoven fabric layer 41, the strength is secured by the connection portions 11b that are not easily deformed.

In the extended state of the first sheet 11 of the waist portion 16, a force that extends in the Y-axis direction is applied, and thereby the stretchable portion 11a extends mainly in the Y-axis direction. In the present embodiment, in the first sheet 11 in the extended state, both the connecting portion 11b and the stretchable portion 11a are extended, but the stretchable portion 11a is extended more largely than the connecting portion 11 b. The connecting portion 11b may be in a state of not being extended substantially, and the expansion portion 11a may be extended to a greater extent than the connecting portion 11 b.

On the other hand, when the force extending in the Y-axis direction is released from the extended state, the first sheet 11 of the waist portion 16 contracts in the Y-axis direction by the elastic force of the elastic wires 42. In the contracted state of the first sheet 11, the dimension of the stretchable and contractible portion 11a in the Y axis direction is smaller than that of the first sheet 11 in the expanded state. Thus, the first sheet 11 is a stretchable nonwoven fabric stretchable in the Y-axis direction.

The elastic threads 42 are made of elastic fibers and arranged at equal intervals in the X-axis direction. In the present embodiment, the elastic threads 42a made of elastic fibers having a relatively large fineness are disposed in the first region 31, and the elastic threads 42b made of elastic fibers having a relatively small fineness are disposed in the second region 32. This makes it possible to make the contraction stresses of the first region 31 and the second region 32 different.

In this way, in the composite sheet 10, the first sheet 11 itself can be stretched by the elastic force of the elastic wire 42. Therefore, the composite sheet 10 can expand and contract the waist portion 16 of the outer cover 8 in the girth direction in fig. 1 by utilizing the stretchability of the first sheet 11. Therefore, the composite sheet 10 can be configured without providing an elastic body such as a rubber thread between the first sheet 11 and the second sheet 12.

The first sheet 11 can be manufactured by any manufacturing method. For example, the first sheet 11 can be manufactured using the elastic threads 42 and two sheets of nonwoven fabric. In this manufacturing method, first, the melt-spun elastic yarn 42 is sandwiched between two nonwoven fabrics to form a laminate. Thereby, the nonwoven fabric is welded to the elastic threads 42.

In the first sheet 11 at this stage, the basis weight of the nonwoven fabric layer 41 is constant, and the stretchable part 11a and the connecting part 11b are not formed. In order to form the stretchable and contractible portions 11a and the connecting portions 11b in the first sheet 11, for example, stretching in the Y-axis direction may be applied only to the stretchable and contractible portions 11 a. This can reduce only the grammage of the expansion/contraction portion 11a while maintaining the grammage of the connection portion 11 b.

The stretching process for forming the stretchable portion 11a and the connecting portion 11b in the first sheet 11 may be any method, and for example, a roll stretching process using two grooved rolls that mesh with each other may be used. In this roll drawing process, the first sheet 11 is alternately drawn by biting the first sheet 11 between the rotating grooved rolls, thereby alternately forming the expansion and contraction parts 11a and the connection parts 11 b. The nonwoven fabric layer 41 is formed by subjecting a laminate formed by sandwiching the elastic yarn 42 between two nonwoven fabrics to a roll drawing process, and drawing the two nonwoven fabrics.

Since the nonwoven fabric and the elastic threads 42 sandwiched between the nonwoven fabrics are welded together to form the first sheet 11, the elastic threads 42 are contained in the nonwoven fabric layer 41 without being exposed on the surface of the nonwoven fabric layer 41, and the first sheet 11 is configured to be stretchable in one piece.

In this manufacturing method, the first sheet 11 can be manufactured without using an adhesive. Therefore, the first sheet 11 does not lose the tactile sensation of the nonwoven fabric layer 41 due to the adhesive. In addition, the first sheet 11 does not spoil the texture of the nonwoven fabric layer 41 due to the elastic threads 42 contained in the nonwoven fabric layer 41. Therefore, the soft texture inherent to the nonwoven fabric layer 41 can be directly obtained in the first sheet 11.

The elastic resin contained in the nonwoven fabric layer 41 of the first sheet 11 is not limited to the structure using the elastic filaments 42, as long as it has elasticity at least in the Y-axis direction.

For example, the elastic resin contained in the nonwoven fabric layer of the first sheet 11 may be elastic fibers made of short fibers, for example. The elastic fibers are arranged so as to extend in one direction without crossing each other, but when elastic fibers made of short fibers are used, the elastic fibers may be arranged randomly or may be arranged so as to be oriented in any one direction. In these configurations, the nonwoven fabric layer 41 can be welded to the elastic resin, and therefore the first sheet 11 can be produced without using an adhesive.

(adhesive layer)

As shown in fig. 2, the adhesive layer 13 includes a plurality of adhesive portions 21 disposed between the first sheet 11 and the second sheet 12. As shown in fig. 5, the adhesive layer 13 is disposed so that a series of patterns are formed in the first region 31a (first region 31b) and the second region 32a (second region 32b) across the abdominal portion 16a (back portion 16 b).

In the present embodiment, the adhesive layer 13 is provided in a series of patterns over the entire ventral portion 16a and the entire dorsal portion 16b having the stretchable region. The adhesive layer 13 is composed of a plurality of adhesive portions 21 arranged at intervals in the circumferential direction of the waistline. The adhesive portion 21 extends across the first region 31a (first region 31b) and the second region 32a (second region 32b) of the abdominal portion 16a (back portion 16 b). The plurality of adhesive sections 21 extend continuously in one direction, in the vertical direction in the present embodiment, in a strip shape having an equal width and being long and narrow, and are arranged at equal intervals in the circumferential direction of the waistline.

In the present embodiment, the adhesive layer 13 is provided on the waist portion 16 having the stretchable region, but the adhesive layer 13 may be provided in a series of patterns also in the crotch portion 17 and continuously with the waist portion 16.

Typically, the adhesive layer 13 is formed of an adhesive. As a method for forming the adhesive layer, for example, various printing methods, various transfer methods, and the like can be used. As the printing method, for example, gravure printing, relief printing, offset printing, or the like can be used. As the transfer method, for example, roller transfer, thermal transfer, or the like can be used.

As the adhesive for forming the adhesive layer 13, a hot melt adhesive can be used. The adhesive layer 13 can be formed using various adhesives such as a thermoplastic adhesive and a reactive adhesive, in addition to a hot-melt adhesive. The adhesive layer 13 may be formed by various adhesive members other than an adhesive. Examples of such adhesive members include sheet-like members having adhesiveness on both sides, such as double-sided tapes.

(second sheet)

The second sheet 12 having the non-stretchable non-woven fabric constituting a part of the composite sheet 10 may be formed of any non-stretchable member that is not easily stretchable in the Y-axis direction. As the non-stretchable member constituting the second sheet 12, for example, nonwoven fabric, woven fabric, paper, or the like can be used. For example, the second sheet 12 may be formed of a nonwoven fabric using the same fibers as the nonwoven fabric layer 41 of the first sheet 11 in order to obtain the same skin feel as the first sheet 11.

As shown in fig. 2, the outer shape of the second sheet 12 substantially matches the shape of the first sheet 11 in the extended state except for the folded portion 20. Since the adhesive layers 13 extend in the vertical direction and are arranged at intervals in the circumferential direction of the waistline, the second sheet 12 forms a plurality of raised portions 35 which are raised toward the opposite side of the first sheet 11 in the natural state in which the outer covering 8 in the extended state of the first sheet 11 is released after the first sheet 11 and the second sheet 12 in the extended state are bonded via the adhesive layers 13, as shown in fig. 5. The ridge portion 35 is formed by the second sheet 12 bulging in a direction away from the first sheet 11 between adjacent rows of the adhesive portions 21.

In the present embodiment, as shown in fig. 4, since the plurality of adhesive sections 21 constituting the adhesive layer 13 are arranged at equal intervals in the circumferential direction of the waistline, the respective swelling sections 35 extend at equal widths in the vertical direction, are arranged at equal intervals in the circumferential direction, and form wrinkles in a pattern uniform in the plane on the inner side of the waist section 16 of the outer body 8. In this way, in the disposable diaper 1, the plurality of raised parts 35 of the second sheet 12 form a series of patterns in a natural state in which no extension is applied.

Here, the series of patterns refers to a state in which the pattern formed by the plurality of protrusions 35 formed in the first region 31 is the same as the pattern formed by the plurality of protrusions 35 formed in the second region 32, and the pattern formed in each region is continuously formed in the vicinity of the boundary between the first region 31 and the second region 32 without interruption (tendency, form, and the like).

In the present embodiment, since the second sheet 12 is disposed on the inner side of the disposable diaper 1, the raised portion 35 is formed on the inner side of the disposable diaper 1. On the other hand, since the first sheet 11 is positioned outside the disposable diaper 1, no raised portion is formed on the outer surface of the disposable diaper 1.

[ method for producing an outer Package ]

The exterior body 100 is formed by disposing the adhesive layer 13 on the first sheet 11 that is elongated at a constant elongation and bonding the adhesive layer to the second sheet 12. Here, the bonding at a constant elongation means that the second sheet 12 is bonded in a state where the high shrinkage stress region P1 and the low shrinkage stress region P2 of the first sheet 11 are elongated at the same elongation.

Specifically, in a state where the first sheet 11 is stretched at a constant elongation, as shown in fig. 4, the adhesive layer 13 is disposed over the entire region corresponding to the waist portion 16 including the folded portion 20. The second sheet 12 is superposed on the first sheet 11 on which the adhesive layer 13 is disposed, and both are adhered by the adhesive layer 13. In this state, the folded portion 20 is extended from a region where the first sheet 11 and the second sheet 12 overlap, and the adhesive layer 13 is disposed on the folded portion 20.

After the second sheet 12 is bonded to the first sheet 11, the extended folded portion 20 is folded back toward the inside of the exterior body 8, and the folded portion 20 is bonded to the second sheet 12. This forms the exterior package 8.

Next, after the absorbent body 9 is bonded and fixed to the inside of the outer package 8 in the stretched state, the back side portion 16b and the stomach side portion 16a are overlapped while maintaining the stretched state, and the corresponding side edge portions are joined to form the side seal 18. In this way, a pants-type disposable diaper 1 is manufactured.

In the manufactured disposable diaper 1, the ridges 35 having a series of patterns are formed inside in a natural state without applying any tension from the outside.

[ methods for measuring recovery from elongation and elongation ]

The recovery from elongation and the elongation of the stretch nonwoven fabric used in the first sheet 11 can be measured in the following manner.

(method of measuring elongation recovery)

A sample piece of a stretch nonwoven fabric having a length of 50mm and a width of 25mm was prepared, and the sample piece was fixed at a chuck interval L0 using a Tensilon tensile tester ("Auto Graph AG-X precision electronic universal tester manufactured by shimadzu corporation"), stretched at a speed of 300mm/min to a length L2(L2 ═ L0 × 2) at 100% elongation, and then returned at the same speed as the tensile speed, and the length of the sample piece when the tensile load became 0 was taken as a length L1 after the elongation was recovered. The elongation recovery at 100% elongation was calculated according to the following formula.

Elongation recovery rate at 100% elongation (%) { (L2-L1)/(L2-L0) } × 100

(method of measuring elongation)

A sample piece having the same size as a sample piece using the method for measuring the elongation recovery rate was elongated under the same conditions as the measurement of the elongation recovery rate, and the elongation at the time of breaking was defined as the elongation.

[ measuring method of the dimensions in the circumferential direction of the first region and the second region ]

The disposable diaper 1 is placed on a table in a natural state, and the circumferential dimension relationship between the first region 31 and the second region 32 of the outer package 8 in the natural state can be observed by measuring the circumferential width between the side seal 18 and the region sandwiched by the extensions of the pair of both side edge portions of the absorbent body 9 that define the width direction of the absorbent body 9.

In the present embodiment, the first region and the second region have the same circumferential dimension in the natural state. That is, the side seals 18 are equidistant from the extended lines of the side edge portions of the absorbent body 9 in the circumferential direction. Here, the equality means that the value of the distance in one region is in the range of 95% to 105% of the distance in the other region.

[ measurement methods of shrinkage stress value, dimension of each region, and shrinkage stress value ]

(shrinkage stress value, size of each region)

The preferable shrinkage stress value in the package 8 is as follows.

The contraction stress of the first region 31 is preferably 1.4cN/mm or more, more preferably 2cN/mm or more, and further preferably 5cN/mm or less, and is preferably 1.4cN/mm or more and 5cN/mm or less, more preferably 2cN/mm or more and 5cN/mm or less.

The shrinkage stress of the second region 32 is preferably 0.1cN/mm or more, more preferably 0.5cN/mm or more, and further preferably 3cN/mm or less, more preferably 2.5cN/mm or less, and is preferably 0.1cN/mm or more and 3cN/mm or less, more preferably 0.5cN/mm or more and 2.5cN/mm or less.

The shrinkage stress of the third region 33 is preferably 1.4cN/mm or more, more preferably 1.5cN/mm or more, and further preferably 4cN/mm or less, more preferably 3.5cN/mm or less, and is preferably 1.4cN/mm or more and 4cN/mm or less, more preferably 1.5cN/mm or more and 3.5cN/mm or less.

These numerical values are set as appropriate according to the size of the disposable diaper corresponding to the size of the wearer's body.

The contraction stress of the first region 31 is preferably 1.2 times or more, more preferably 1.4 times or more, and further preferably 3 times or less, more preferably 2.5 times or less, and further preferably 1.2 times or more and 3 times or less, more preferably 1.4 times or more and 2.5 times or less, of the contraction stress of the second region 32.

The contraction stress of the first region 31 is preferably 1.1 times or more, more preferably 1.5 times or more, and further preferably 2.5 times or less, more preferably 2 times or less, and further preferably 1.1 times or more and 2.5 times or less, more preferably 1.5 times or more and 2 times or less, of the contraction stress of the third region 33.

Further, the dimensions in each region are preferably set as follows.

The length of the first region 31 in the vertical direction is preferably 1.0 time or more, more preferably 1.2 times or more, and further preferably 2 times or less, more preferably 1.8 times or less, and further preferably 1.0 time or more and 2 times or less, more preferably 1.2 times or more and 1.8 times or less, of the length of the second region 32.

The length of the third region 33 in the vertical direction is preferably equal to or less than 1/2 of the length of the second region 32.

The length of the third region 33 in the vertical direction is preferably 0.5cm or more, more preferably 5cm or less, even more preferably 3cm or less, even more preferably 1.5cm or less, and is preferably 0.5cm or more and 5cm or less, more preferably 0.5cm or more and 3cm or less, even more preferably 0.5 to 1.5cm or less. The specific dimensions vary depending on the size of the disposable diaper 1.

The shrinkage stresses of the first to third regions 31 to 33 of the exterior body 8 can be measured in the following manner.

(method of producing sample for measuring shrinkage stress of outer body)

The side seal 18 of the disposable diaper 1 is torn, the outer cover 8 is stretched at the same rate in any one of the first to third regions 31 to 33 of the outer cover 8, developed and spread out in a plane, and for each of the front and

back side portions

16a and 16b, the sample is cut out in a rectangular shape from the region of each of the first to third regions 31 to 33 along a straight line parallel to the width direction and further along a straight line parallel to the front-back direction. The sample was cut out from a region other than the region of the outer package 8 facing the absorbent body 9 in a plan view, that is, a region sandwiched between extension lines of a pair of both side edge portions of the absorbent body 9 defining the width direction of the absorbent body 9, and a region located outside. The size of the sample in the stress-released state (natural state) after cutting was cut out in a band-like manner to 70mm in the width direction and 50mm in the front-rear direction, and a sample having a width of 50mm and a length of 70mm was prepared. In addition, when it is difficult to form a sample of 70mm in the width direction, the length is appropriately changed.

(measurement method)

Both sides in the longitudinal direction (corresponding to the width direction of the disposable diaper) of the cut sample of each region were fixed between a pair of chucks of the Tensilon tensile tester. The sample was fixed by holding the chuck at portions of the sample, each having a width of 10mm from the end edge, at both ends in the longitudinal direction. The chuck interval was set to 50mm, and the sample was fixed in a natural state (a state of naturally contracting without applying an external force). Further, the chuck interval is appropriately adjusted according to the length of the sample piece. The sample was stretched in the same direction as the diaper width direction (the sample longitudinal direction) at 300mm/min to a point where the sample length (the distance between chucks) became 185% of the natural length, and then the tensile load (cN) per unit length (1mm) in the width direction when the sample contracted to 140% of the length was defined as the contraction stress. The index of 140% is to reproduce the extended state of the sample when the pants-type disposable diaper 1 is worn.

[ fineness of elastic fiber ]

The fineness of the elastic fibers of the elastic filaments 42a used in the first region 31 is preferably 20 μm or more, more preferably 40 μm or more, and further preferably 400 μm or less, more preferably 300 μm or less, and further preferably 20 μm or more and 400 μm or less, more preferably 40 μm or more and 300 μm or less.

The fineness of the elastic fibers of the elastic threads 42b used in the second region 32 is preferably 10 μm or more, more preferably 20 μm or more, and further preferably 300 μm or less, more preferably 250 μm or less, and further preferably 10 μm or more and 300 μm or less, more preferably 20 μm or more and 250 μm or less.

The fineness of the elastic fiber used in the first region 31 is preferably 1.2 times or more, more preferably 1.5 times or more, and further preferably 3 times or less, more preferably 2.5 times or less, and further preferably 1.2 times or more and 3 times or less, more preferably 1.5 times or more and 2.5 times or less, of the fineness of the elastic fiber used in the second region 32.

The fineness of the elastic fiber corresponds to the fiber diameter of the elastic fiber.

[ Effect of the present embodiment ]

In the disposable diaper 1 of the present embodiment, the first sheet 11 for making the composite sheet 10 constituting the front and

back side portions

16a, 16b stretchable is a seamless one-piece member, and has a structure in which regions having different contraction stresses in the vertical direction are present. This makes it possible to obtain a disposable diaper 1 having an appearance and a touch like underwear and shorts which has no seam in the whole area of the abdomen-side portion 16a and the whole area of the back-side portion 16b and has a uniform texture like a cloth.

In the present embodiment, the exterior body 8 is manufactured by bonding the second sheet 12 while extending both the high shrinkage stress region P1 corresponding to the first region 31 of the first sheet 11 and the low shrinkage stress region P2 corresponding to the second region 32 and the third region 33 at a constant elongation. This allows the outer cover 8 to have a uniform texture like a cloth over the entire waist portion 16 regardless of the regions with different magnitudes of contraction stress when the outer cover is extended and released. In the exterior body 8 thus manufactured, the first region 31 and the second region 32 of the exterior body 8 have the same dimensions in the circumferential direction in a natural state, and the first region 31 and the second region 32 have different contraction stresses in the girth direction.

In addition, in the present embodiment, the contraction stress of the first region 31 located on the lower side is higher than that of the second region 32 and the third region 33 located on the upper side of the waist portion 16, and therefore, the disposable diaper 1 can be effectively prevented from slipping down during wearing.

Since the abdomen of the wearer, particularly an infant, is protruded as a physical feature of the wearer, when the tightening force of the portion of the waist portion abutting the protruded abdomen is increased, the waist portion of the disposable diaper is gradually contracted due to the high tightening force, and the waist portion is easily slid down to the portion where the abdomen is narrowed.

In the present embodiment, the first region 31 having a high contraction stress is provided below the waist portion 16 so that the region having a relatively high tightening force of the waist portion 16 abuts on the narrowed portion of the waist portion, and therefore, slipping down during wearing can be effectively prevented. In order to effectively prevent such slipping-off during wearing, the relationship between the contraction stress of the second region 32 and the third region 33 located on the upper side of the waist portion 16 and the contraction stress of the first region 31 located on the lower side is preferably set to the above-described range.

In this way, in the present embodiment, since the abdomen-side portion 16a and the back-side portion 16b are each configured to have the regions in which the contraction stresses are different from each other by the seamless stretch nonwoven fabric (first sheet 11), the disposable diaper 1 having the function as a diaper, the appearance and the touch of underwear shorts having a good fit and a uniform texture like a cloth can be obtained.

In the present embodiment, the vicinity of the opening peripheral end 15 of the waist opening 7 corresponds to the third region 33. The third region 33 has a higher shrinkage stress than the second region 32 disposed immediately therebelow, and has a lower shrinkage stress than the first region 31.

In ordinary underwear pants, rubber is used for the waist. In the present embodiment, by providing the third region 33 having a higher contraction stress than the second region 32, it is possible to provide the wearer with a proper tightening feeling at the waist opening end portion during wearing, and to provide the wearer with a wearing feeling like underwear pants. Further, by providing the third region 33, it is possible to give the operator a feeling of stretching like underwear and shorts when the operator spreads the waist opening 7 of the disposable diaper 1 and passes the legs through the leg openings 14, etc. during the wearing operation.

Further, by setting the length of the third region 33 in the front-rear direction to the above range, a wearing feeling close to that of ordinary underwear pants using rubber at the waist can be given to the wearer.

In the present embodiment, the ridge portions 35 are formed in a series of patterns in the front side portion 16a and the back side portion 16b across the first region 31 and the second region 32. This makes it possible to obtain a disposable diaper 1 having an appearance and a tactile feeling like underwear and shorts in which a smooth pattern is formed without interruption in the abdomen-side portion 16a and the back-side portion 16b of the disposable diaper 1 and a uniform texture like a cloth is obtained.

Each of the raised portions 35 forms a hollow portion extending in the vertical direction together with the first sheet 11. At the same time, the raised parts 35 also form hollow parts extending in the vertical direction between the raised parts 35 and the skin (outside the raised parts 35) when worn. The hollow portions formed inside and outside the ridge portion 35 can function as an air passage through which air flows, and the composite sheet 10 can be made to be a sheet having excellent cushioning properties and excellent air permeability.

< other embodiments >

In any of the embodiments, similarly to the first embodiment, a composite sheet composed of a first sheet and a second sheet bonded to each other via an adhesive layer is used for the front side portion and the back side portion, and a composite sheet having the same shrinkage stress distribution as that of the first embodiment is used for the waist portion of the outer body.

In the following embodiments, the first sheet including the first region and the second region having different vertical shrinkage stresses is formed of a single seamless stretch nonwoven fabric, as in the first embodiment. This makes it possible to obtain a disposable diaper having a uniform texture over the entire abdomen-side portion and the entire back-side portion, such as underwear pants, and having an appearance and a tactile sensation similar to those of a cloth.

In the following embodiments, the contraction stress of the first region located on the lower side is higher than that of the second region and the third region located on the upper side of the waist portion, and therefore, it is possible to effectively prevent slipping-off during wearing of the disposable diaper. Further, the third region may be configured in such a manner that the contraction stress is the same as that of the first contraction region, and the contraction stress of the first region located on the lower side is higher than that of the second region located on the upper side, so that the slipping-off during wearing can be effectively prevented as well.

In the following embodiments, by providing the third region having a higher contraction stress than the second region, it is possible to provide the wearer with a proper tightening feeling at the waist opening end portion when wearing the garment, and to provide a wearing feeling like underwear. Further, by providing the third region, the operator can expand the waist opening of the disposable diaper during wearing operation, and can give the operator a feeling of stretching like underwear when passing the legs through the leg openings and the like.

In the following embodiments, the first region and the second region are spanned by the waist portion, and the ridge portions formed by the second sheet form a series of patterns. Thus, a disposable diaper having a smooth pattern without interruption formed on the front and back side portions and having an underwear-like appearance and a feeling like underwear with a uniform texture like a cloth can be obtained.

The second to seventh embodiments will be described in detail below. The same components as those of the first embodiment are denoted by the same reference numerals, and description thereof may be omitted.

< second embodiment >

The disposable diaper 2 of the present embodiment will be described with reference to fig. 1 and 8. Fig. 8 shows a state in which the folded-back portion 20 is not unfolded.

The disposable diaper 2 shown in fig. 1 includes an outer package 28 and an absorbent member 9. The disposable diaper 2 of the present embodiment is configured by adding the elastic body 29 to the structure of the disposable diaper 1 described in the first embodiment. As shown in fig. 8, the elastic body 29 is disposed in the third region 33. As the form of the elastic body 29, a linear elastic body such as a rubber thread having a rectangular, circular, or polygonal cross section, or a belt-like elastic body such as a flat rubber can be used. The elastic body 29 is disposed in the folded composite sheet (stretch sheet) 10 in the third region 33 along the circumferential direction of the waistline.

The elastic body 29 is disposed on the front side portion 16a and the back side portion 16b along the entire width in the circumferential direction so as to have a length equal to or greater than the width of each of the front side portion 16a and the back side portion 16b in a natural state in which no tension is applied.

Thus, the disposable diaper 2 in a natural state can provide a clean appearance such as underwear without wrinkles caused by the elastic body 29 occurring at the opening peripheral edge 15 of the waist opening 7.

Further, by providing the elastic body 29, even if the stretchability is broken and slackened at the end portion of the first sheet 11 on the side of the waist opening 7 during use, the stretchability of the end portion on the side of the waist opening 7 can be maintained by the elastic body 29, and a stable quality disposable diaper 2 can be obtained.

When the disposable diaper 2 is worn, the elastic body 29 stretches, thereby giving a tight feeling to the wearer. This can give the wearer a feeling of use like underwear.

Next, as third to sixth embodiments, examples in which the pattern shape of the adhesive layer is different from that of the first embodiment will be described.

In the above-described embodiment, the adhesive layer has a pattern in which a plurality of adhesive portions extending continuously in the vertical direction are arranged at equal intervals in the width direction, but the pattern of the adhesive layer is not limited to this. As described in the following embodiments, the plurality of adhesive sections may be disposed at intervals in the circumferential direction on the ventral side and the dorsal side, and may be disposed continuously or discontinuously in one direction across the first region 31 and the second region 32.

Thus, the plurality of ridges formed by the second sheet 12 form a series of patterns, and a smooth pattern is formed over the entire abdominal portion and the entire back portion without interruption.

In the following third to sixth embodiments, the pattern of the adhesive layer is different from that of the first embodiment, and thus, only the shape of the pattern forming the ridge portion is different. In the following third to sixth embodiments, a plan view showing a developed state of the outer package of the disposable diaper is used, but these plan views each show a state in which the side seal portion of the disposable diaper shown in fig. 1 is torn to separate the abdomen-side portion and the back-side portion, and the outer package is stretched along the XY plane. In the plan view of the package, the second sheet is not shown, and only the first sheet and the adhesive layer are shown, in order to explain the arrangement pattern of the adhesive layer constituting a part of the package.

< third embodiment >

The disposable diaper 3 of the present embodiment will be described with reference to fig. 1 and 9.

The disposable diaper 3 shown in fig. 1 includes an outer package 38 and an absorbent member 9. The outer package 38 shown in fig. 9 is composed of a waist portion 36 and a crotch portion 37 formed continuously, and the waist portion 36 has a front side portion 36a and a back side portion 36 b. The exterior body 38 has the first sheet 11 and the second sheet 12 bonded to each other via the adhesive layer 22.

The adhesive layer 22 is disposed between the first sheet 11 and the second sheet 12, and is composed of a plurality of elongated strip-shaped adhesive portions 25 continuously extending in the width direction at equal widths. The plurality of adhesive portions 25 have the same width and are arranged at equal intervals in the vertical direction. The adhesive portions 25 are arranged in a series of patterns over the entire width of each of the front and

back portions

36a and 36b having the stretchable and contractible regions of the outer package 38.

The disposable diaper 3 of the present embodiment has a plurality of protrusions formed by the second sheet 12 bulging in a direction away from the first sheet 11 between adjacent rows of the bonded portions 25 in a natural state. The raised portions extend in the width direction, are formed at equal intervals in the vertical direction, and form wrinkles in a pattern uniform in the plane on the inner side of the waist portion 36 of the outer body 38.

< fourth embodiment >

The disposable diaper 4 of the present embodiment will be described with reference to fig. 1 and 10.

The disposable diaper 4 shown in fig. 1 includes an outer package 48 and an absorbent member 9. The outer package 48 shown in fig. 10 is constituted by a waist portion 46 and a crotch portion 47 formed continuously, and the waist portion 46 has a front side portion 46a and a back side portion 46 b. The exterior body 48 has a first sheet 11 and a second sheet 12 bonded to each other via an adhesive layer 23.

The adhesive layer 23 includes a plurality of adhesive portions 26 disposed between the first sheet 11 and the second sheet 12. The plurality of adhesive portions 26 have an elongated strip shape continuously extending with an equal width in a direction inclined with respect to the width direction and the vertical direction. The plurality of adhesive portions 26 each have the same width and are arranged at equal intervals. The adhesive sections 26 are arranged in a series of patterns over the entire ventral portion 46a and the entire dorsal portion 46b of the outer package 48 having the stretchable region.

The disposable diaper 4 has a plurality of protrusions formed by the second sheet 12 bulging in a direction away from the first sheet 11 between adjacent rows of the bonded portions 26 in a natural state. The respective ridges extend with equal width obliquely with respect to the circumferential direction and the vertical direction, and are arranged in plurality at equal intervals.

In the present embodiment, the adhesive portion 26 is formed in a shape that extends continuously along a straight line in an oblique direction, but is not limited thereto. For example, the plurality of adhesive portions may constitute an adhesive portion group discontinuously arranged on a straight line in an oblique direction, and the plurality of adhesive portion groups may be arranged at intervals in the circumferential direction to constitute the adhesive layer.

< fifth embodiment >

The disposable diaper 5 of the present embodiment will be described with reference to fig. 1 and 11.

The disposable diaper 5 shown in fig. 1 includes an outer package 58 and an absorbent member 9. The outer package 58 shown in fig. 11 is composed of a waist portion 56 and a crotch portion 57 formed continuously, and the waist portion 56 has a front side portion 56a and a back side portion 56 b. The exterior body 58 has the first sheet 11 and the second sheet 12 bonded to each other via the adhesive layer 24.

The adhesive layer 24 is disposed between the first sheet 11 and the second sheet 12, and is composed of a plurality of adhesive part groups 27 disposed at equal intervals in the circumferential direction of the waistline. Each bonding portion group 27 is composed of a plurality of bonding portions 27a arranged at equal intervals in the vertical direction. In other words, the adhesive portion group 27 is configured by arranging a plurality of adhesive portions 27a discontinuously on a straight line along the vertical direction.

The disposable diaper 5 of the present embodiment has a plurality of protrusions formed by the second sheet 12 bulging in a direction away from the first sheet 11 between adjacent rows of the bonded part groups 27 in a natural state. The protrusions are arranged in a matrix.

In the disposable diaper 5, the hollow portions of the plurality of raised portions spatially communicate with each other in the front side portion 56a and the back side portion 56b, and therefore, the diaper has good air permeability.

< sixth embodiment >

The disposable diaper 6 of the present embodiment will be described with reference to fig. 1 and 12.

The disposable diaper 6 shown in fig. 1 includes an outer package 68 and an absorbent body 9. The outer package 68 shown in fig. 12 is constituted by a waist portion 66 and a crotch portion 67 formed continuously, and the waist portion 66 has a front side portion 66a and a back side portion 66 b. The exterior body 68 has the first sheet 11 and the second sheet 12 bonded to each other via the adhesive layer 63.

The adhesive layer 63 is composed of a plurality of adhesive portions 64 arranged in a staggered pattern between the first sheet 11 and the second sheet 12. The plurality of adhesive sections 64 are arranged at intervals in the circumferential direction of the waistline, and are also arranged at intervals in the vertical direction. The plurality of adhesive portions 64 are discontinuously arranged in the vertical direction. Here, the staggered shape means that the adhesive portions are staggered with each other between the adhesive portion groups in which the plurality of adjacent adhesive portions 64 are discontinuously arranged in the vertical direction.

The disposable diaper 6 has a plurality of raised portions formed by the second sheet 12 bulging in a direction away from the first sheet 11 between the adjacent adhesive portions 64 in a natural state. The plurality of ridges are arranged in a staggered pattern.

The disposable diaper 6 has a plurality of protrusions substantially uniform in both the width direction and the vertical direction over the entire region of the front and

back side portions

66a, 66b, and therefore can provide the outer covering 68 with a cushion feeling and a soft appearance.

In the above embodiments, examples of patterns of some adhesive layers have been described, but the patterns are not limited to these. For example, in the first, fourth, fifth, and sixth embodiments, the adhesive portions extending continuously in the vertical direction or the oblique direction or the adhesive portion group in which a plurality of adhesive portions are discontinuously arranged are arranged at equal intervals in the circumferential direction.

In contrast, the adhesive portions or the adhesive portion groups extending in the vertical direction or the oblique direction may be arranged at different arrangement intervals in the circumferential direction. For example, in each of the back and abdominal portions constituting the waist portion, the arrangement interval of the adhesive portions or the adhesive portion groups arranged on both side portions in the width direction close to the side seal portion may be narrower than the arrangement interval of the adhesive portions or the adhesive portion groups arranged on the center portion in the width direction. The arrangement interval may be changed so as to gradually or continuously narrow from the center portion to the side portions of the back and the abdomen, respectively.

Even if the bonding portions are arranged at intervals while changing the arrangement intervals in the width direction in this way, the arrangement pattern of the bonding portions is the same in the high shrinkage stress region P1 and the low shrinkage stress region P2 arranged along the vertical direction, and therefore, the plurality of ridges of the second sheet form a series of patterns across the high shrinkage stress region P1 and the low shrinkage stress region P2.

This forms a smooth pattern without interruption from the high-contraction stress region P1 to the low-contraction stress region P2 in the entire ventral portion region and the entire dorsal portion region.

< seventh embodiment >

In the first embodiment, the first sheet 11 having the high shrinkage stress region P1 and the low shrinkage stress region P2 is formed by making the fineness of the elastic fibers constituting the elastic resin different from each other, but the present invention is not limited thereto.

For example, the arrangement intervals of the elastic wires may be different.

In the first sheet 50 shown in fig. 13, the elastic threads 62 constituting the elastic resin are composed of elastic fibers having the same fineness, for example, elastic fibers having a fineness of 100 μm in this case, in the first region 31 which becomes the high shrinkage stress region P1 and in the second region 32 which becomes the low shrinkage stress region P2. The plurality of elastic wires 62a for the first region 31 and the plurality of elastic wires 62b for the second region 32 extend in the circumferential direction and are arranged at intervals in the vertical direction. The arrangement interval of the elastic wires 62a in the first region 31 is narrower than the arrangement interval of the elastic wires 62b in the second region 32. This makes it possible to increase the contraction stress of the first region 31 to be higher than that of the second region 32.

The arrangement interval of the elastic threads 62a arranged in the first region 31 is preferably 0.2mm or more, more preferably 0.5mm or more, and further preferably 2.5mm or less, more preferably 2mm or less, and further preferably 0.2mm or more and 2.5mm or less, more preferably 0.5mm or more and 2mm or less.

The arrangement interval of the elastic threads 62b arranged in the second region 32 is preferably 0.5mm or more, more preferably 0.8mm or more, and further preferably 5.0mm or less, more preferably 3.0mm or less, and further preferably 0.5mm or more and 5.0mm or less, more preferably 0.8mm or more and 3.0mm or less.

The arrangement interval of the elastic wires 62b arranged in the second region 32 is preferably 1.2 times or more, more preferably 1.5 times or more, further preferably 3 times or less, more preferably 2.5 times or less, further preferably 1.2 times or more and 3 times or less, more preferably 1.5 times or more and 2.5 times or less the arrangement interval of the elastic wires 62a arranged in the first region 31.

Alternatively, the first region 31 may have a higher shrinkage stress than the second region 32 by making the weight of the elastic resin per unit area of the first region 31 greater than that of the second region 32.

The elastic resin disposed in the first region 31 preferably has a weight per unit area of 5g/m²Above, more preferably 7g/m²The above is preferably 15g/m²Hereinafter, it is more preferably 12g/m²Hereinafter, it is preferably 5g/m²Above and 15g/m²Hereinafter, more preferably 7g/m²Above and 12g/m²The following.

The elastic resin disposed in the second region 32 preferably has a weight per unit area of 4g/m²Above, more preferably 5g/m²The above is preferably 12g/m²Hereinafter, more preferably 10g/m²Hereinafter, it is preferably 4g/m²Above and 12g/m²Hereinafter, more preferably 5g/m²Above and 10g/m²The following.

The weight per unit area of the elastic resin used for the first region 31 is preferably 1.2 times or more, more preferably 1.5 times or more, and further preferably 3 times or less, more preferably 2.5 times or less, and further preferably 1.2 times or more and 3 times or less, more preferably 1.5 times or more and 2.5 times or less, of the second region 32.

Alternatively, the first region 31 may have a higher shrinkage stress than the second region 32 by increasing the density of the plurality of elastic fibers constituting the elastic resin of the first region 31 to be higher than that of the second region 32.

The density of the plurality of elastic fibers constituting the elastic resin used in the first region 31 is preferably 1.2 times or more, more preferably 1.5 times or more, and further preferably 3 times or less, more preferably 2.5 times or less, and further preferably 1.2 times or more and 3 times or less, more preferably 1.5 times or more and 2.5 times or less, of the second region 32.

< other embodiments >

While the embodiments of the present invention have been described above, it is needless to say that the present invention is not limited to the above-described embodiments, and various modifications can be made without departing from the scope of the present invention.

For example, although the adhesive layer is provided so that the ridge portions form a series of patterns in the above-described embodiment, the adhesive layer may not be provided so that the ridge portions are formed by a series of patterns, as long as the first sheet is stretched at a constant elongation and then the second sheet is bonded to the first sheet in the production of the exterior body. The outer cover is produced by stretching the first sheet at a constant elongation and then bonding the first sheet to the second sheet, whereby a disposable diaper having an appearance and a touch like underwear and shorts having a uniform texture across a plurality of regions of the outer cover having different contraction stresses can be obtained.

In the above-described embodiment, the first sheet and the second sheet are used for the outer covering, but the outer covering may be formed only by the first sheet (stretch sheet), and the side seals may be formed and bonded while the front and back side portions are stretched at a constant rate.

In the above-described embodiment, both the ventral portion and the dorsal portion of the waist portion have the stretchable region, but at least one of the ventral portion and the dorsal portion may have the stretchable region.

In addition, in the case where a laminate sheet in which a first sheet (stretchable sheet) and a second sheet (non-stretchable sheet) are laminated is used in the waist portion of the outer covering of the above-described embodiment, and the laminate sheet is applied to a disposable diaper, the first sheet as the stretchable sheet is disposed on the outer surface side and the second sheet is disposed on the inner surface side. In this structure, the raised portions are formed on the outer surface of the disposable diaper, but since the plurality of raised portions are formed in a series of patterns, the waist portion of the disposable diaper can be formed into the appearance and touch of underwear shorts having a uniform texture such as a cloth having a uniform feeling as a whole.

In the above-described embodiment, the folded-back portion formed by folding back the first sheet is provided at the opening peripheral edge end of the waist opening, but the folded-back portion may not be provided. In this case, the outer package is composed of a composite sheet in which a first sheet (stretchable sheet) and a second sheet (non-stretchable sheet) having the same outer shape are laminated. Further, even when the exterior body is formed of only the first sheet, the folded portion may be provided or may not be provided.

In the case where the folded-back portion is not provided, for example, in the case of forming the adhesive layer pattern as in the first, fourth, fifth, and sixth embodiments, the raised portion forms an opening together with the first sheet at the opening peripheral edge of the waist opening portion. Thus, the air flowing inside the hollow raised part easily flows to the outside of the disposable diaper through the opening formed by the raised part, and the air permeability is further excellent.

In each of the above embodiments, a part of the elastic element of the stretchable sheet in the region of the waist portion facing the absorbent body may be cut or removed to form a non-stretchable region. Therefore, the contraction of the stretchable sheet does not act on the absorbent body and wrinkle in the absorbent body, and does not hinder the liquid absorption performance of the absorbent body.

The pants-type absorbent article of the present invention may not be a pants-type disposable diaper previously formed in a pants shape by joining side seals as in the above-described embodiment. That is, the pants-type absorbent article of the present invention may be a tape-type disposable diaper having a pants shape in which a tape such as a surface fastener is provided instead of the side seal portion and the tape is attached when worn.

The pants-type absorbent article of the present invention may not be a disposable diaper for infants, but may be a disposable diaper for adults or children. The pants-type absorbent article of the present invention may not be a disposable diaper as long as it is a type of absorbent article to be worn on the lower body. Examples of such pants-type absorbent articles include pants-type sanitary napkins, pants-type urine-receiving pads, and the like.

Next, a stretchable sheet having a high shrinkage stress region P1 and a low shrinkage stress region P2, which can be applied to the pants-type absorbent article, will be described.

The stretch panel of the present invention is a continuous panel having no seam in the planar direction, including a plurality of regions different from each other in terms of tensile stress of shrinkage (hereinafter, referred to as shrinkage stress). As a method of forming a sheet including a plurality of regions having different tensile stresses due to shrinkage, there is a method of connecting sheets of a plurality of different members having different shrinkage stresses. The stretchable sheet of the present invention is not formed by connecting a plurality of sheets of different members, and therefore, not only is the strength of the object against contact with the stretchable sheet and against external force generated by a handling person's grip excellent, but also the stretchable sheet has an appearance that is integrally perceived. By providing a structure without a seam, it is possible to prevent deformation such as wrinkles from occurring in the stretchable sheet without restricting extension in the vicinity of the seam when sheets of different members are joined in a contracted state and without restricting contraction in the vicinity of the seam when sheets of different members are joined in an extended state. Here, the contraction stress is a tensile stress generated by contraction in which the stretchable sheet is contracted to return to its original shape when the stretchable sheet in a natural state is expanded. In the present specification, the natural state refers to a state of being left on a horizontal plane without applying an external force to the stretchable sheet to cause deformation such as elongation or crushing, unless otherwise specified. When such a stretch sheet is used for an outer covering of an absorbent article, for example, leakage of excrement, diffusion of moisture, and leakage to the outside of the article are not likely to occur because no seams are formed.

Such an extensible sheet is suitable for use as, for example, an outer covering of a pants-type disposable diaper as an absorbent article requiring stretchability in a waistline portion.

< eighth embodiment >

The stretchable sheet, the stretching device used in the production of the stretchable sheet, the method for producing the stretchable sheet, and the pants-type disposable diaper using the stretchable sheet according to the eighth embodiment will be described below in order.

[ Structure of stretchable sheet ]

First, the stretch panel according to the first embodiment will be described with reference to fig. 14 to 17.

The stretch panel 70 includes a plurality of elastic threads 87a, and a first nonwoven fabric 85 and a second nonwoven fabric 86 which are arranged in two layers facing each other with the elastic threads 87a interposed therebetween.

The plurality of elastic threads 87a can expand and contract in the first direction (Y-axis direction) to form the elastic layer 87. The stretchable sheet 70 can be stretched in the Y-axis direction by the plurality of elastic wires 87 a. The Y-axis direction corresponds to the expansion and contraction direction of the expansion piece 70. The Z-axis direction corresponds to the thickness direction of the stretchable sheet 70. The X-axis direction as the second direction corresponds to a direction orthogonal to the stretching direction and the thickness direction.

The first nonwoven fabric 85 and the second nonwoven fabric 86 are not limited to specific types, and may be selected from, for example, a through-air nonwoven fabric, a hot-roll nonwoven fabric, a spunlace nonwoven fabric, a spunbond nonwoven fabric, a meltblown nonwoven fabric, and the like.

The fibers constituting the nonwoven fabric are not limited to specific types, and may be selected from chemical fibers such as polyethylene, polypropylene, polyester, and polyamide. The nonwoven fabric may be formed of a composite fiber containing a plurality of types of chemical fibers. Further, natural fibers such as cotton and silk may be blended with the fibers constituting the nonwoven fabric.

In the present embodiment, the first nonwoven fabric 85 and the second nonwoven fabric 86 are the same kind of nonwoven fabric.

The elastic wire 87a is a linear elastic body extending in the Y-axis direction. A plurality of elastic wires 87a are arranged at equal intervals in the X-axis direction orthogonal to the Y-axis direction. The elastic threads 87a are directly welded to the first nonwoven fabric 85 and the second nonwoven fabric 86, respectively. That is, the elastic threads 87a are bonded to the first nonwoven fabric 85 and the second nonwoven fabric 86 without using an adhesive or the like. In this way, the first nonwoven fabric 85 and the second nonwoven fabric 86 are welded to the elastic threads 87a sandwiched between these nonwoven fabrics to form the stretch panel 70, and therefore, the elastic threads 87a are not exposed on the surface of the stretch panel 70 but are incorporated in the nonwoven fabric layer, and the stretch panel 70 is configured to be stretchable independently.

The elastic wire 87a is formed of an elastic material such as a thermoplastic elastomer. In particular, the elastic threads 87a are preferably formed of a thermoplastic elastomer which is easily fused to the fibers constituting the nonwoven fabric.

As the thermoplastic elastomer forming the elastic yarn, for example, styrene-based elastomers, olefin-based elastomers, polyester-based elastomers, polyurethane-based elastomers, and the like can be used. In addition, the elastic yarn may be formed by combining a plurality of thermoplastic elastomers. The elastic yarn may be a core-sheath type or side-by-side type composite fiber.

In this embodiment, as shown in fig. 14 and 15, the elastic wire 87a is in a wave shape in a natural state. The stretchable sheet 70 has a wave shape according to the wave shape of the elastic wire 87 a. In other words, the boundary surface between the first nonwoven fabric 85 and the second nonwoven fabric 86 is formed in a wave shape according to the wave shape of the elastic threads 87 a.

The corrugated stretch panel 70 has a corrugated shape in which top portions 81 on the first nonwoven fabric 85 side and bottom portions 82 on the second nonwoven fabric 86 side are alternately arranged. The top portion 81 and the bottom portion 82 are connected via a wall portion 83.

The first nonwoven fabric 85 (second nonwoven fabric 86) has a plurality of protrusions 74(71) and a plurality of flat portions 75(72) made of fibers constituting the nonwoven fabric. As shown in fig. 16, in a state where the wave shape of the stretch sheet 70 is stretched into a flat shape, the convex portions 74(71) and the flat portions 75(72) each extend in the X-axis direction and are alternately arranged in plural numbers along the Y-axis direction.

In the present embodiment, the case where the boundary surface between the first nonwoven fabric 85 and the second nonwoven fabric 86 is wavy in a natural state is exemplified, but may be planar. At this time, the stretchable sheet takes the form shown in fig. 16 in a natural state.

In the present embodiment, as shown in fig. 14 and 15, the

convex portions

74 and 71 are located on the wall portion 83 of the corrugated expansion sheet 70.

Flats

75, 72 are located at the top 81 or bottom 82 of the corrugated telescoping piece 70.

As described above, in the present embodiment, since the stretchable sheet 70 has a wave shape in addition to the convex portions 74 provided on the first nonwoven fabric 85 and the convex portions 71 provided on the second nonwoven fabric 86, when the stretchable sheet 70 is used for the outer covering of a disposable diaper, the contact area between the skin of the wearer of the disposable diaper and the stretchable sheet 70 can be reduced, and stuffiness, rash, and the like can be effectively prevented. Further, since the difference between the natural length of the stretch panel 70 in the Y-axis direction and the length when stretched can be increased, the disposable diaper can be applied to a wide-size wearer.

The fibers constituting the

convex portions

74 and 71 are fibers that are plastically deformed by roll drawing described later, and are held in a state of being stretched by the roll drawing, and are fibers that are peeled from the elastic threads 87a by the roll drawing. The fibers constituting the

flat portions

75 and 72 are fibers that are not plastically deformed by roll drawing described later.

The convex portions 74(71) form the stretchable portions of the first nonwoven fabric 85 (second nonwoven fabric 86), and the flat portions 75(72) form the connecting portions of the first nonwoven fabric 85 (second nonwoven fabric 86). The expansion and contraction section and the connection section will be described later.

The fiber density of the convex portions 74(71) is relatively lower than that of the flat portions 75 (72).

In the present embodiment, the projecting portion 71 of one surface of the stretchable sheet 70 is located at the position of the projecting portion 74 of the other surface, and the flat portion 72 of the other surface is located at the position of the flat portion 75 of the one surface in the thickness direction. In this way, in the present embodiment, the projections 74 and the projections 71 are formed in a substantially plane-symmetrical shape at the boundary surface between the first nonwoven fabric 85 and the second nonwoven fabric 86. Further, the regions that become the connection portions of the first nonwoven fabric 85 and the second nonwoven fabric 86 are also present oppositely in the thickness direction of the stretch sheet 70.

Therefore, in the present embodiment, the stretchable portion and the connecting portion of the first nonwoven fabric 85 and the stretchable portion and the connecting portion of the second nonwoven fabric 86 are not separately described, and the stretchable portions of the two types of nonwoven fabrics are referred to as the stretchable portions 70a of the stretchable sheet 70, and the connecting portion of the two types of nonwoven fabrics is referred to as the connecting portion 70b of the stretchable sheet 70.

A part of the fibers constituting the first nonwoven fabric 85 (second nonwoven fabric 86) is peeled from the elastic threads 87a and plastically deformed, and the convex portions 74 (convex portions 71) are formed in a loop shape in the stretch panel 70 in a natural state. The convex portion 74 (convex portion 71) becomes a stretching amount portion (portion for realizing stretching) when the stretch panel 70 is stretched. The region where the fibers of the plastically deformed nonwoven fabric are arranged is the stretch portion 70a of the stretch sheet 70. Thus, the

convex portions

74 and 71 constitute the extensible and contractible portion 70a which is extensible and contractible in the Y-axis direction.

On the other hand, the fibers constituting the first nonwoven fabric 85 (second nonwoven fabric 86) are fibers that are not elongated by the roll drawing process and are not plastically deformed, and are fibers having a length almost unchanged from the length before the roll drawing process, and form the flat portions 75 (72). The region where the fibers of the non-plastically deformed nonwoven fabric are arranged is the connecting portion 70b of the stretch panel 70. Thus, the

flat portions

75 and 72 constitute the connecting portion 70b which is less stretchable than the stretchable portion 70a in the Y-axis direction.

Accordingly, the elastic filaments 87a and the first nonwoven fabric 85 (second nonwoven fabric 86) have less weld-bonded regions per unit area in the stretchable part 70a than in the connecting part 70 b.

As shown in fig. 17, in the stretchable sheet 70, a plurality of stretchable sections 70a and connecting sections 70b extending in the X-axis direction are alternately arranged along the Y-axis direction. The plurality of connecting portions 70b are arranged at intervals in the Y-axis direction and extend in the X-axis direction. The connecting portion 70b is disposed between adjacent ones of the plurality of expansion portions 70a, and connects the adjacent expansion portions 70a to each other.

In the extended state of the extensible sheet 70, the force applied to extend in the Y-axis direction extends mainly in the Y-axis direction in the extensible part 70 a. That is, the stretchable sheet 70 in the stretched state does not actually stretch at the connecting portion 70 b. The stretchable sheet 70 in the stretched state may be stretched in the connecting portion 70b if the amount of stretch is smaller than the amount of stretch in the stretchable portion 70 a.

When the extensible sheet 70 releases the force of extension in the Y-axis direction from the extended state, the elastic wire 87a contracts in the Y-axis direction due to its elastic force. The dimension of the stretchable panel 70a in the Y-axis direction is smaller in the contracted state of the stretchable panel 70 than in the extended state of the stretchable panel 70. In this way, even if the stretchable sheet 70 is not provided with an elastic member such as a rubber thread, the stretchable sheet 70 itself can be stretched by the elastic force of the elastic wire 87 a.

As shown in fig. 18 (a), in the stretch panel 70 in the natural state, the elastic threads 87a are not stretched and are in the contracted state. The fibers constituting the first nonwoven fabric 85 (second nonwoven fabric 86) form projections 74(71) in the stretchable part 70a, and the projections 74(71) project in the direction away from the elastic threads 87 a.

As shown in fig. 18 (B), in the stretch portion 70a of the stretch panel 70 in the stretched state, the fibers of the first nonwoven fabric 85 constituting the convex portions 74 and the fibers of the second nonwoven fabric 86 constituting the convex portions 71 are plastically deformed and stretched by the roll drawing process, and therefore, the portions that bulge out as the elastic filaments 87a contract are stretched so as to be straight. On the other hand, in the connecting portion 70b, the fibers of the nonwoven fabric positioned in the connecting portion 70b are not plastically deformed, and therefore, are less likely to stretch.

In this embodiment, as shown in fig. 14 to 17, each of the plurality of convex portions 74 and the convex portions 71 is a convex portion that extends continuously along the X-axis direction without being interrupted and has a locally different height.

Each of the convex portions 74(71) has a high convex portion 74b (71b) as a second convex portion and a low convex portion 74a (71a) as a first convex portion, which are different in height from each other in the X-axis direction. As shown in fig. 15 and 16, the height of the high protrusions 74b (71b) is higher than the height of the low protrusions 74a (71a), and the fiber density is low.

The high protrusions 74b (71b) and the low protrusions 74a (71a) having different fiber densities can be formed by adjusting the meshing amount of the tooth grooves in the roll drawing process using the tooth groove drawing roll. The production method will be described later.

In the stretchable part 70a of the stretchable sheet 70 in the stretched state, when the stretchable sheet 70 is stretched, the portion that bulges out in a ring shape is stretched so as to be straight as the elastic wire 87a is stretched. That is, the higher the height of the convex portion is, the larger the elongation at the time of elongation is.

Therefore, the elongation at elongation of the stretchable part 70a with the high convex portions 74b (71b) is larger than the elongation at elongation of the stretchable part 70a with the low convex portions 74a (71 a). Thus, in the stretch panel 70, the regions where the high protrusions 74b (71b) are present and the regions where the low protrusions 74a (71a) are present have different amounts of extensibility during stretching. That is, the region where the high convex portions 74b (71b) are present is more easily elongated than the region where the low convex portions 74a (71a) are present, and when both regions are elongated at the same elongation, the region where the low convex portions 74a (71a) are present is higher than the region where the high convex portions 74b (71b) are present with respect to the contraction stress to return the stretch panel 70 to its original state.

As shown in fig. 14 and 16, in the stretchable panel 70, a region where the plurality of high protrusions 74b (71b) extending in the X-axis direction are arranged to be spaced apart from each other in the Y-axis direction constitutes a low shrinkage stress region P2. The region where the plurality of low protrusions 74a (71a) extending in the X-axis direction are arranged apart from each other in the Y-axis direction constitutes a high shrinkage stress region P1.

In the high shrinkage stress region P1 and the low shrinkage stress region P2, a plurality of elastic threads 87a are arranged at equal intervals.

In the stretchable panel 70 of the present embodiment, the low shrinkage stress region P2, the high shrinkage stress region P1, and the low shrinkage stress region P2 are provided in this order in the X-axis direction. The stretchable sheet 70 has a higher shrinkage stress in a region in the center in the X-axis direction than in other regions.

Thus, as shown in fig. 19, when the stretchable sheet 70 is stretched at a uniform elongation in the Y-axis direction, the upper and lower portions of the stretchable sheet 70 in the X-axis direction are easily stretched, and the central portion is not easily stretched, so that the central portion in the X-axis direction is formed in a tapered shape.

Referring to fig. 21, the first nonwoven fabric 85 is exemplified, but the second nonwoven fabric 86 may have the same structure as the first nonwoven fabric 85.

In the present embodiment, the first nonwoven fabric 85 is formed by, for example, a spunbond method, is embossed, and has a plurality of heat fusion bonded portions 61. The heat-fusion bonded portion 61 is formed in a predetermined pattern on the entire surface of the first nonwoven fabric 85, and thereby a uniform skin feel can be obtained over the entire surface. The heat-fused part in the present invention refers to a part where fibers in a nonwoven fabric are heat-fused to each other, and it is not necessary to emboss the nonwoven fabric. For example, a point at which fibers in a through-air nonwoven fabric are fused to each other by hot air is also a heat fusion part of the present invention.

When the stretch panel 70 is formed using the first nonwoven fabric 85, the heat-fusion bonded portions 61 may be arranged at a distance from each other at the boundary 69 between the high shrinkage stress region P1 and the low shrinkage stress region P2 of the first nonwoven fabric 85. Here, it is assumed that there is a rectangular heat-fusion-bond-portion absent region 65 surrounded by the heat fusion bonds 61 adjacently arranged on the boundary 69 and the heat fusion bonds 61 adjacently arranged along the X-axis direction with the boundary 69 interposed therebetween. Each side of the rectangular heat-fusion-part absent region 65 is parallel to the boundary 69 (extending in the Y-axis direction) or an imaginary line (extending in the X-axis direction) orthogonal to the boundary 69, and is in contact with the heat fusion part 61. The length of the heat-fusion-bond-absent region 65 in the X-axis direction is preferably longer than the length in the Y-axis direction. This makes it possible to prevent the first nonwoven fabric 85 from being damaged.

Generally, the thickness of the heat-fused portion (embossed portion) formed by the embossing is flattened compared to the region other than the embossed portion, and a level difference is present in the vicinity of the edge of the embossed portion. Further, the embossed portion is easily deteriorated and damaged by the influence of heat, and the edge of the embossed portion is easily a starting point of material breakage.

In the present invention, when the stretch panel 70 is stretched, a force in the shear direction acts on the boundary 69 between the high-shrinkage stress region P1 and the low-shrinkage stress region P2. Here, in the heat-fusion-bond-part-absent region 65, by making the length in the X-axis direction of the heat-fusion-bond-part-absent region 65 longer than the length in the Y-axis direction, the displacement amount during elongation can be reduced as compared with making the length in the Y-axis direction longer than the length in the X-axis direction.

Therefore, in the vicinity of the boundary 69 where the material is likely to be loaded by the extension of the stretch panel 70, sufficient strength can be obtained without using another support for ensuring the strength.

In addition, in the stretch sheet 70, the length in the X axis direction of the region 65 where the heat-fusion-bonded part is not present may be longer than the length in the Y axis direction in at least one of the first nonwoven fabric 85 and the second nonwoven fabric 86.

[ stretching device ]

Next, a stretching apparatus used for manufacturing the stretch panel 70 will be described with reference to fig. 22 and 23. The stretch sheet 70 is produced by subjecting a laminate 70' described later to roll drawing by a drawing device.

The stretching device 90 includes a pair of

toothed stretching rollers

91, 92. A driving device, not shown, for driving the rollers of the stretching device 90 is connected to the rollers. By this driving device, each roller rotates.

On the peripheral surface of the spline stretching roller 91(92), a plurality of teeth 79(80) are provided radially from the rotation axis in the direction orthogonal to the rotation direction of the roller, and concave and convex portions are formed along the rotation direction by the plurality of teeth. The convex portions of the uneven portions correspond to the teeth 79(80), and the concave portions correspond to the grooves between the adjacent teeth 79 (80).

Hereinafter, a sheet in a state before the stretch sheet 70 is subjected to the roll stretching process will be referred to as a laminate 70', and the stretch sheet 70 subjected to the roll stretching process and exhibiting stretchability will be described separately. The laminate 70 ' is formed by laminating two sheets of the pre-processed first nonwoven fabric (reference numeral 85 ' in fig. 24) and the pre-processed second nonwoven fabric (reference numeral 86 ' in fig. 24) as the base material by supplying heated elastic threads 87a and applying pressure. In the laminate 70 ', the elastic yarn 87a is directly welded to the first nonwoven fabric 85 ' and the second nonwoven fabric 86 ' before processing by the heat of the elastic yarn 87a melt-spun in the ground. The first nonwoven fabric 85 'and the second nonwoven fabric 86' before processing each have a plurality of heat-fusion bonded portions 61.

The laminate 70' is sandwiched between the pair of grooved stretching

rollers

91 and 92, and is conveyed by the rotation of the grooved stretching

rollers

91 and 92. The roll drawing process is performed by passing the laminate 70' between the teeth 79 of one of the cogged drawing rolls 91 and the grooves of the opposing and meshing cogged drawing roll 92, and between the teeth 80 of the cogged drawing roll 92 and the grooves of the opposing and meshing cogged drawing roll 91.

As shown in fig. 23B, the teeth 79(80) have high tooth height portions 77B (78B) and low tooth height portions 77a (78a) having a lower tooth height than the high tooth height portions 77B (78B).

In the present embodiment, the low tooth height portions 77a (78a) of the teeth 79(80) are located at the central portion trisected in the axial direction orthogonal to the rotational direction, the high tooth height portions 77b (78b) are located on both sides of the low tooth height portions 77a (78a), respectively, and the tooth height of the central portion of the teeth 79(80) in the axial direction is low.

The region of the teeth 79 where the low tooth height portion 77a exists and the region of the teeth 80 where the low tooth height portion 78a exists, and the region of the teeth 79 where the high tooth height portion 77b exists and the region of the teeth 80 where the high tooth height portion 78b exists are opposed to each other in the roll drawing process, respectively.

In the present embodiment, the blank roller 76 around which the laminate 70 'is wound is rotatably provided upstream of the grooved stretching

rollers

91 and 92 of the stretching device 90, and the laminate 70' can be drawn out in the direction of the arrow C. A pair of feed rollers 93 is provided between the material roller 76 and the above-described

grooved stretching rollers

91 and 92.

The feed speed of the laminate 70' fed between the

grooved stretching rollers

91 and 92 is adjusted by adjusting the rotation speed of the feed roller 93. The laminate 70' can be fed between the cogged stretching

rollers

91 and 92 in a state where tension is applied thereto by the pair of feed rollers 93 and the cogged stretching

rollers

91 and 92.

A pair of discharge rollers 94 is provided downstream of the grooved stretching

rollers

91 and 92. The feed speed of the stretch sheet 70 fed out from between the

grooved stretching rollers

91 and 92 is adjusted by adjusting the rotational speed of the pair of discharge rollers 94. The stretch sheet 70 after the roll drawing process is fed out in the direction of arrow D by the discharge roller 94.

The stretch panel 70 is pulled out from between the

grooved stretching rollers

91 and 92 in a state where tension is applied by the discharge roller 94. Since the stretch sheet 70 is easily stretched even when a small tension is applied thereto, the tension applied to the stretch sheet 70 after the stretching process by the pair of discharge rollers 94 is preferably lower than the tension applied to the laminate 70' before the stretching process by the pair of feed rollers 93.

The laminate 70' having passed between the pair of feed rollers 93 is not given stretchability because it is before the roll stretching process. The laminate 70' to which no stretchability is imparted is subjected to roll drawing by engaging the teeth 79 with the teeth 80 in a state in which the laminate is positioned between the

grooved drawing rollers

91 and 92, thereby forming the stretchable part 70a and the connecting part 70 b. This allows the stretch sheet 70 to exhibit stretchability.

The adjustment of the stretching degree in the region to become the stretching portion 70a is performed by adjusting the rotation speed of the cogged stretching

rollers

91, 92 and the rotation speed of the pair of feed rollers 93. By adjusting the ratio of the rotation speed of the feed roller 93 and the rotation speed of the cogged stretching

rollers

91 and 92, the tension applied to the laminate 70 'when the laminate 70' is fed between the cogged stretching

rollers

91 and 92 is adjusted. For example, when the height of the convex portions 74 made of nonwoven fabric in the stretchable portion 70a is to be relatively increased, the tension applied to the laminate 70' fed into the

grooved stretching rollers

91 and 92 is increased.

The amount of meshing between the low tooth height portion 77a and the low tooth height portion 78a is smaller than the amount of meshing between the high tooth height portion 77b and the high tooth height portion 78 b. Thus, the draw ratio is higher in the region where the high tooth height portion 77b meshes with the high tooth height portion 78b than in the region where the low tooth height portion 77a meshes with the low tooth height portion 78 a.

In the regions of the laminate 70' processed at a relatively high stretch ratio, the high protrusions 74b and the high protrusions 71b are formed. The region of the laminated body 70' passing between the high tooth height portion 77b of the tooth 79 and the high tooth height portion 78b of the tooth 80 is a low contraction stress region P2, which is a region where the high convex portion 74b and the high convex portion 71b of the stretchable sheet 70 are formed.

On the other hand, in the regions of the laminate 70' processed at a relatively low stretch ratio, the low protrusions 74a and the low protrusions 71a are formed. The region of the stacked body 70' passing between the low tooth-height portion 77a of the tooth 79 and the low tooth-height portion 78a of the tooth 80 is a high shrinkage stress region P1, which is a region where the low convex portion 74a and the low convex portion 71a of the stretchable sheet 70 are formed.

In this way, in the roll stretching process of the present embodiment, the regions having different meshing amounts of the upper and lower teeth are provided, and the laminate 70' is subjected to the process so that the stretching ratios are different for each region, thereby forming the convex portions 74(71) having the high convex portions 74b (71b) and the low convex portions 74a (71 a).

Further, the draw ratio can be appropriately set by adjusting the ratio of the rotation speed of the feed roll 93 to the rotation speed of the grooved draw rolls 91 and 92.

In the present embodiment, the teeth of the respective grooved stretching

rollers

91 and 92 have the high tooth height portion and the low tooth height portion, but the teeth of only one grooved stretching roller may have the high tooth height portion and the low tooth height portion, and the teeth of the other grooved stretching roller may have the same tooth height in the axial direction.

[ method for producing stretchable sheet ]

Next, a method for manufacturing the stretch panel 70 using the stretching device 90 described above will be described with reference to fig. 22 and 23.

In the drawing shown in the upper part of fig. 24, the laminate 70' is processed by being sandwiched between a pair of cogged stretching

rollers

91 and 92 of the stretching device 90. The laminate 70' is naturally subjected to roll drawing and has a concavo-convex shape, and the entire stretchable sheet 70 may be formed in a wave shape, but in fig. 24 (B) and (C), the concavo-convex shape and the wave shape are illustrated in a state where the elastic thread 871 is not stretched but stretched in a flat shape for convenience.

As shown in the lower drawing of fig. 24 (a), in the laminate 70 ' before the roll drawing process, the elastic threads 87a are fused to the fibers of the first nonwoven fabric 85 ' and the second nonwoven fabric 86 ' before the process at the interface. The laminate 70' at this stage has no stretchability. The elastic wire 87a is stretched along the conveying direction of the laminated body 70'. The conveying direction corresponds to the Y-axis direction of the stretchable sheet 70.

Next, as shown in fig. 24 (B), the laminate 70 'is partially stretched by meshing the laminate 70' between the rotating grooved stretching

rollers

91 and 92. Specifically, the area of the stacked body 70' between the top portion 88 of the adjacent tooth 79 and the top portion 89 of the tooth 80 when the tooth 79 and the tooth 80 mesh with each other is elongated, and the area abutting against the top portion 88 of the tooth 79 and the top portion 89 of the tooth 80 is hardly elongated.

In the stretched region of the laminate 70 ', the elastic threads 87a are stretched, and the fibers constituting the first nonwoven fabric 85 ' and the second nonwoven fabric 86 ' before processing are stretched and plastically deformed to be stretched, and part of the fibers fused to the elastic threads 87a is peeled off from the elastic threads 87 a.

On the other hand, in the non-stretched region of the laminate 70 ', the elastic threads 87a are not stretched, and the fibers constituting the first nonwoven fabric 85 ' and the second nonwoven fabric 86 ' before processing are not plastically deformed, and the fibers are hardly peeled from the elastic threads 87 a.

When the elongation of the elastic wire 87a by the roll drawing process is released, as shown in fig. 24 (C), the fiber that is plastically deformed by the roll drawing process and maintains the elongation state, and the fiber that is peeled off from the elastic wire 87a, are annularly expanded so as to be separated from the elastic wire 87a in accordance with the contraction of the elastic wire 87a, and the convex portion 74 and the convex portion 71 are formed. The

convex portions

74 and 71 formed by the fibers of the nonwoven fabric bulging become the stretching amount of the stretch sheet 70 when stretched. The region where the fibers of the nonwoven fabric plastically deformed in this manner are arranged becomes the stretchable part 70a of the stretchable sheet 70.

On the other hand, the nonwoven fabric forming

flat portions

75 and 72 maintain the regions where the elastic threads 87a are welded to the elastic threads 87a without causing the elastic threads 87a to stretch and the fibers to plastically deform during roll drawing. The region where the fibers of the nonwoven fabric are arranged without plastic deformation becomes the connecting portion 70b of the stretch panel 70.

In this way, when the teeth 79 mesh with the teeth 80 during the roll drawing process, the region of the stacked body 70 'abutting against the top portions 88 of the teeth 79 and the top portions 89 of the teeth 80 becomes the connecting portion 70b, and the region of the stacked body 70' located between the top portions 88 of the adjacent teeth 79 and the top portions 89 of the teeth 80 becomes the expansion/contraction portion 70 a. The expansion and contraction portions 70a and the connection portions 70b are alternately formed in the Y-axis direction.

In the roll drawing process of the present embodiment, the low-profile high portion 77a of the spline drawing roll 91 and the low-profile high portion 78a of the spline drawing roll 92 are in contact with the central portion of the laminate 70' that is formed by trisecting the laminate in the X-axis direction orthogonal to the conveyance direction, and the high-profile high portion 77b of the spline drawing roll 91 and the high-profile high portion 78b of the spline drawing roll 92 are in contact with both side portions in the X-axis direction.

In the present embodiment, the meshing amount of the low-tooth-

height portions

77a, 78a is set to 2mm, and the meshing amount of the high-tooth-

height portions

77b, 78b is set to 3 mm. Thus, the stretch ratio of the region in the center in the X axis direction, which has been subjected to the stretch processing by the meshing of the low-

profile portions

77a and 78a, is lower than the stretch ratio of the region in both side portions in the X axis direction, which has been subjected to the stretch processing by the meshing of the high-

profile portions

77b and 78 b.

In this manufacturing method, the stretch panel 70 can be manufactured without using an adhesive. Therefore, the stretch panel 70 can flexibly maintain the texture of the first nonwoven fabric 85 and the second nonwoven fabric 86 with the adhesive. In the stretch panel 70, the elastic threads 87a are enclosed in the first nonwoven fabric 85 and the second nonwoven fabric 86, and even if the elastic threads 87a are used, the soft texture of the nonwoven fabric itself can be obtained without impairing the texture of the first nonwoven fabric 85 and the second nonwoven fabric 86.

[ Structure of Disposable diaper ]

Fig. 25 is a perspective view of a disposable diaper 30 (hereinafter, referred to as a diaper 30) according to an embodiment of the present invention in which the stretch panels 70 having the regions with different contraction stresses are applied to the outer package 39. The diaper 30 is a pants-type absorbent article that collects excrement from an infant as a wearer without leakage.

The diaper 30 includes an outer package 39 and an absorber 9. The outer package 39 constitutes an outer package of the diaper 30. The absorber 9 is held inside the outer package 39. That is, the outer package 39 is disposed on the outer surface side of the absorbent body 9 opposite to the skin side of the wearer when worn.

Hereinafter, the inner side of each structure means the side located on the skin side of the wearer when the diaper is worn, and the outer side means the side opposite to the skin side of the wearer.

The absorber 9 is configured to collect excrement and absorb liquid contained in the excrement. The absorber 9 is formed in a band shape and disposed in a wide range from the crotch portion 40 of the outer package 39 to the abdomen-side portion 34a and the back-side portion 34b of the waist portion 34.

The outer package 39 is formed by the waist portion 34 and the crotch portion 40 formed continuously. The waist portion 34 forms a waist opening 7 and is disposed at the waist of the wearer. The waist portion 34 is formed of an extensible member that is extensible in the girth direction so as to be fitted to the waist portion of the wearer. In fig. 25, the crotch portion 40 is located below the waist portion 34 and is disposed in the crotch region of the wearer.

The waist portion 34 has a front abdominal portion 34a disposed on the front side and a rear back portion 34b disposed on the rear side when worn. The front and

back side portions

34a and 34b are joined to the side seal portions 18 provided at both ends in the width direction orthogonal to the front-rear direction, for example, by heat sealing, ultrasonic sealing, or the like. Thus, the waist portion 34 is formed in a tubular shape, and the waist opening 7 is formed between the abdomen-side portion 34a and the back-side portion 34 b.

The crotch portion 40 is located between the stomach-side portion 34a and the back-side portion 34 b. The crotch unit 40 connects the front side portion 34a and the back side portion 34b so that a pair of leg openings 14 through which the legs of the wearer are inserted are formed on both sides in the width direction. The crotch unit 40 is provided with leg gathers 19 including rubber threads 19a arranged along the leg openings 14.

In the diaper 30 and the outer package 39 shown in fig. 26 and 27, the side seals 18 are torn from the state shown in fig. 25 to separate the front side portion 34a and the back side portion 34b, and the outer package 39 and the absorbent body 9 are stretched along the XY plane.

Fig. 27 is a plan view showing a developed state of the outer package 39 of the diaper 30 of fig. 25, showing the positions of the high-contraction stress region P1 and the low-contraction stress region P2. Fig. 27 corresponds to a view of the exterior body 39 as viewed from the outside, and is a state in which a first sheet 44 described later is positioned on the near side. The expansion and contraction regions of the exterior body 39 are represented by a dot pattern, and the degree of the magnitude of the contraction stress in each region is represented by the density of the dot pattern. The higher the shrinkage stress, the higher the density of the dot pattern, and the lower the shrinkage stress, the lower the density of the dot pattern.

The outer package 39 has a stretchable sheet, and the outer package 39 of the present embodiment is composed of a composite sheet 60 as a stretchable member in which the first sheet 44 and the second sheet 12 as a base sheet are bonded together with the adhesive layer 13. The first sheet 44 is formed using the stretchable sheet 70 having a plurality of regions with different contraction stresses. The regions of the first sheet 44 corresponding to the ventral portion 34a and the dorsal portion 34b can expand and contract in the circumferential direction of the waist.

The first sheet 44 is a stretch nonwoven fabric made of a nonwoven fabric containing an elastic resin layer. The second sheet 12 is a non-stretch sheet including a non-stretch nonwoven fabric disposed to face the first sheet 44. The adhesive layer 13 bonds the first sheet 44 to the second sheet 12. In the present embodiment, the second sheet 12 is provided so as to face the inside of the first sheet 44, and the first sheet 44 is positioned on the outer surface 39a side of the exterior body 39.

In the diaper 30 shown in fig. 25 and 26 and the outer package 39 shown in fig. 27, the X-axis direction corresponds to the front-rear direction, the Y-axis direction corresponds to the width direction, and the Z-axis direction corresponds to the thickness direction. The circumferential direction of the waistline in the ventral portion 34a and the dorsal portion 34b of the waist portion 34 in fig. 25 corresponds to the width direction Y in fig. 26 and 27. The stretch direction Y of the stretch panel 70 described above coincides with the width direction Y of the diaper 30.

Hereinafter, the waist portion 34 may be described as being in the vertical direction. The vertical direction corresponds to the vertical direction of the diaper 30 when the wearer wears the diaper 30 in a standing state. The front-back direction is the same as the up-down direction.

The waist portion 34 of the outer package 39 is stretchable in the circumferential direction of the waistline. As shown in fig. 27, the abdomen-side portion 34a (back-side portion 34b) of the waist portion 34 of the first sheet 44 constituting the exterior body 39 which requires stretchability in the girth direction has a first region 31a (first region 31b) and two second regions 32a (second regions 32b) which have different contraction stresses from each other.

The first region 31a (first region 31b) of the stomach-side portion 34a (back-side portion 34b) is located in a central region among the three regions in the vertical direction perpendicular to the circumferential direction of the waistline, and in the present embodiment, the second region 32a (second region 32b) is located in both of a pair of end regions provided so as to face each other in the vertical direction across the central region. In the present embodiment, the second region is formed by disposing the high convex portions in both of the pair of end regions, but the high convex portions may be disposed in at least one of the pair of end regions.

The first region 31 (second region 32) includes a first region 31a of the ventral portion (second region 32a of the ventral portion) and a first region 31b of the dorsal portion (second region 32b of the dorsal portion), and is particularly referred to as the first region 31 (second region 32) when it is not necessary to distinguish between the two regions.

The contraction stresses of the first region 31 and the second region 32 are different from each other. The first region 31 is a high-shrinkage stress region P1, and the second region 32 is a low-shrinkage stress region P2. The

low protrusions

71a, 74a are disposed in the first region 31, and the

high protrusions

71b, 74b are disposed in the second region 32. With respect to the shrinkage stress, the first region 31 is relatively high and the second region 32 is relatively low. The width dimension (length in the Y-axis direction) of the low shrinkage stress region P2 is substantially equal to the width dimension of the high shrinkage stress region P1.

That is, the waist portion 34 is configured as follows: when the first region 31 and the second region 32 are elongated at the same elongation, the force (shrinkage stress) to be restored to the original state after shrinkage differs in each region. Thus, when the waist portion 34 is elongated at the same elongation, different tightening pressures act on the wearer in each region.

In the present embodiment, the upper side (the vicinity of the waist opening 7) and the lower side (the region of the waist portion 34 near the crotch portion 40) of the waist portion 34 are configured such that the contraction stress is lower, that is, the tightening pressure is weaker, than the vertically central portion of the waist portion 34.

(construction of outer body)

The respective structures of the package 39 will be described with reference to fig. 26 and 27.

The first sheet 44 is a continuous stretch panel without seams formed by connecting the stomach-side portion 34a to the back-side portion 34b through the crotch portion 40.

In the composite sheet 60, the first sheet 44 itself can be stretched by the elastic force of the elastic wire 87a, and the composite sheet 60 functions as a stretchable sheet. Therefore, in the composite sheet 60, the waist portion 34 of the outer package 39 can be stretched in the girth direction in fig. 25 by the stretchability of the first sheet 44. Therefore, the composite sheet 60 can be configured without providing an elastic body such as a rubber thread between the first sheet 44 and the second sheet 12.

The adhesive layer 13 has a plurality of adhesive portions 21 arranged between the first sheet 44 and the second sheet 12. The adhesive layer 13 is disposed across the first region 31a (first region 31b) and the two second regions 32a (second regions 32b) of the ventral portion 34a (back portion 34 b). The plurality of adhesive portions 21 extend continuously in the vertical direction and are arranged at intervals in the circumferential direction of the waistline.

Typically, the adhesive layer 13 is formed of an adhesive. As the adhesive for forming the adhesive layer 13, a hot melt adhesive can be used. The adhesive layer 13 can be formed using various adhesives such as a thermoplastic adhesive and a reactive adhesive, in addition to a hot-melt adhesive.

The second sheet 12 made of a non-stretchable nonwoven fabric constituting a part of the composite sheet 60 can be made of any non-stretchable sheet that is not easily stretchable in the Y-axis direction. As the non-stretchable member constituting the second sheet 12, for example, nonwoven fabric, woven fabric, paper, or the like can be used. For example, the second sheet 12 may be formed of a nonwoven fabric using the same fibers as the first nonwoven fabric 85 and the second nonwoven fabric 86 of the first sheet 44 in order to obtain the same skin feel as the first sheet 44.

The diaper (30) is manufactured as follows.

The exterior body 39 is formed by disposing the adhesive layer 13 on the first sheet 44 that is elongated at a constant elongation and bonding the adhesive layer to the second sheet 12. Here, the bonding at a constant elongation means that the second sheet 12 is bonded in a state where the high shrinkage stress region P1 and the low shrinkage stress region P2 of the first sheet 44 are elongated at the same elongation.

Next, the absorbent body 9 is superposed on the inside of the outer package 39 in the stretched state, and after the two are bonded and fixed, the side seal 18 is formed by superposing the front side portion 34a and the back side portion 34b and joining the corresponding side edge portions while maintaining the stretched state. In this manner, a pants-type diaper 30 is produced.

In the diaper 30 of the present embodiment, the stretchable sheet 70 is used as the first sheet 44 for providing stretchability to the composite sheet 60 constituting the front and

back side portions

34a, 34 b. This makes it possible to obtain a disposable diaper 30 having high body conformability and excellent fit to the waist.

In the diaper 30 of the present embodiment, the stretchable sheet 70 having no seam as described above and having regions of different contraction stresses in the X-axis direction in one sheet member is used as the first sheet 44. This makes it possible to obtain a diaper 30 having an appearance and a touch like underwear pants having a uniform texture like a cloth without seams in the sheet over the entire abdominal portion 34a and the entire back portion 34 b.

In addition, in the diaper 30 of the present embodiment, the central portion in the vertical direction above and below the waist portion 34 is configured to have a high contraction stress and a high tightening pressure when worn, and therefore, it is possible to effectively prevent the diaper 30 from slipping down during wearing.

Since the abdominal circumference is protruded as a characteristic feature of the body of the wearer, particularly the infant, when the tightening force of the portion of the waist portion abutting the protruded abdominal circumference is increased, the tightening force is increased, and therefore, the waist portion of the disposable diaper is gradually contracted, and the waist portion is easily slid down to the portion where the abdominal circumference is narrowed.

In the present embodiment, the first region 31 having a high contraction stress is provided in the vertical center portion of the waist portion 34 so that the region having a relatively high tightening force of the waist portion 34 comes into contact with the narrowed portion of the waist portion, and therefore, slipping down during wearing can be effectively prevented. In order to effectively prevent such slipping-off during wearing, the relationship between the contraction stress at the upper and lower sides of the waist portion 34 and the central portion in the vertical direction is preferably set to the following range.

Hereinafter, the shrinkage stress value, the dimensions of each structure, and the like, which are suitable for using the stretch panel 70 in an outer package of an absorbent article such as a diaper will be described. The numerical values described here are examples, and the dimensions and the like of the respective structures of the stretchable sheet can be appropriately set so as to have a distribution of shrinkage stress suitable for an article using the stretchable sheet.

[ shrinkage stress value ]

(shrinkage stress value of expansion sheet)

When the stretch panel of the present invention is used as an outer package of an absorbent article or the like, the contraction stress at 50% elongation of the low contraction stress region P2 and the high contraction stress region P1 of the stretch panel is set to be equal to or less than the upper limit value described below, so that the skin of the wearer can be kept from being stricken, and the stretch panel can be set to be equal to or more than the lower limit value described below, so that an appropriate wearing state can be maintained.

Here, the outer cover may be formed of a single stretchable sheet or a composite sheet obtained by laminating a stretchable sheet and a non-stretchable sheet as in the diaper 30. In any configuration, by setting the shrinkage stress value in the stretchable sheet alone to be within the range described later, the shrinkage stress distribution suitable for the exterior body can be obtained.

Specifically, the shrinkage stress at 50% elongation of the low shrinkage stress region P2 in which the high protrusions 74b (71b) are arranged is preferably 1cN/mm or more, more preferably 1.5cN/mm or more, further preferably 3cN/mm or less, more preferably 2.5cN/mm or less, further preferably 1cN/mm or more and 3cN/mm or less, more preferably 1.5cN/m or more and 2.5cN/mm or less. In the present embodiment, it is 2 cN/mm.

The shrinkage stress at 100% elongation of the low shrinkage stress region P2 in which the high protrusions 74b (71b) are arranged is preferably 2cN/mm or more, more preferably 2.5cN/mm or more, further preferably 4cN/mm or less, more preferably 3.5cN/mm or less, and further preferably 2cN/mm or more and 4cN/mm or less, more preferably 2.5cN/mm or more and 3.5cN/mm or less. In the present embodiment, it is 3 cN/mm.

The shrinkage stress at 50% elongation of the high shrinkage stress region P1 in which the low convex portions 74a (71a) are arranged is preferably 2cN/mm or more, more preferably 2.5cN/mm or more, further preferably 4cN/mm or less, more preferably 3.5cN/mm or less, and further preferably 2cN/mm or more and 4cN/mm or less, more preferably 2.5cN/mm or more and 3.5cN/mm or less. In the present embodiment, the value is 4 cN/mm.

The shrinkage stress at 100% elongation of the high shrinkage stress region P1 in which the low protrusions 74a (71a) are arranged is preferably 40cN/mm or more, more preferably 50cN/mm or more, further preferably 90cN/mm or less, more preferably 80cN/mm or less, further preferably 40cN/mm or more and 90cN/mm or less, more preferably 50cN/mm or more and 80cN/mm or less. In the present embodiment, the value is 67 cN/mm.

In this way, in the stretchable panel 70, the low-shrinkage stress region P2 has a lower shrinkage stress per unit length in the Y-axis direction than the high-shrinkage stress region P1.

In the present embodiment, a plurality of elastic threads 87a are arranged at equal intervals in the X-axis direction in both the high shrinkage stress region P1 and the low shrinkage stress region P2, and the fineness and density of the elastic threads 87a are the same. Therefore, the difference in contraction stress due to the difference in height between the high projections 74b (71b) and the low projections 74a (71a) is effectively exhibited in the stretchable panel 70.

For example, it is not necessary to separately use elastic wires such that an elastic wire having a high elastic stress is disposed in order to provide a high-shrinkage stress region and an elastic wire having a low elastic stress is disposed in order to provide a low-shrinkage stress region.

Therefore, it is preferable that the stretchable sheet 70 is configured to have a structure in which the convex portions having the high convex portions and the low convex portions are provided, and the contraction stress of 50% elongation and 100% elongation of the high contraction stress region P1 and the low contraction stress region P2 is within the above numerical range.

Hereinafter, a method of manufacturing a sample and a method of measuring the shrinkage stress of the stretchable sheet will be described.

(method of producing sample for measuring shrinkage stress of stretchable sheet)

In an absorbent article including an extensible sheet in a part of its structure, when only a part composed of an elastic yarn and a nonwoven fabric directly joined thereto, which is a minimum structural unit of the extensible sheet, is exposed, only the exposed part can be cut with scissors or a knife. In the case where the exposed portion is not present and the stretchable sheet is bonded to another component with an adhesive, the absorbent article is immersed in acetone, toluene, or butyl acetate for 24 hours, then the minimum structural unit is taken out onto a metal plate, and subjected to air drying treatment in a ventilator for 96 hours to obtain the stretchable sheet. In the case where the above-described exposed portion is not provided and the stretch panel is directly joined to another component by thermal fusion or the like, the stretch panel is obtained by carefully removing the stretch panel by hand without damaging the stretch panel.

The stretch panel obtained by the above method was cut along a straight line parallel to the stretching direction (corresponding to the Y-axis direction) from each of the high-shrinkage stress region P1 and the low-shrinkage stress region P2, and further cut along a straight line parallel to the direction (corresponding to the X-axis direction) orthogonal to the stretching direction, to cut out a rectangular sample. The sample was cut out in a band-like shape in a natural state after cutting, and the size was 70mm in the Y-axis direction and 50mm in the X-axis direction. In addition, when it is difficult to form a sample of 70mm in the width direction, the length is appropriately changed.

(measurement method)

Both sides in the longitudinal direction (corresponding to the Y-axis direction) of the sample of each cut region were fixed between a pair of chucks of a Tensilon tensile tester ("Auto Graph AG-X precision electronic universal material tester manufactured by shimadzu corporation"). The length of the chuck section in the stretching direction was 20mm, and the length in the direction perpendicular to the stretching direction was 60 mm. The sample is fixed by being held by the chuck with an air pressure of at least 1MPa so that the sample is contained in the chuck section at each of both end portions in the longitudinal direction thereof and at a portion having a width of 10mm from the end edge. The chuck spacing was 50mm and the samples were held in a natural state. Further, the chuck interval is appropriately adjusted according to the length of the sample piece. The sample was elongated at 300mm/min, and the tensile load (cN) per unit length (1mm) at the time when the length (inter-chuck distance) of the sample became 150% and 200% of the length in the natural state was defined as a contraction stress at an elongation of 50% and a contraction stress at an elongation of 100%.

(shrinkage stress value of outer body)

When the composite sheet 60 is used to form the outer package 39 of the diaper 30, the composite sheet 60 preferably has the following shrinkage stress values.

The shrinkage stress of the high shrinkage stress region P1 (first region 31) is preferably 1.4cN/mm or more, more preferably 2cN/mm or more, and further preferably 5cN/mm or less, and is preferably 1.4cN/mm or more and 5cN/mm or less, more preferably 2cN/mm or more and 5cN/mm or less.

Hereinafter, a method for producing a sample and a method for measuring the shrinkage stress of the package will be described.

(method of producing sample for measuring shrinkage stress of outer body)

The side seals 18 of the disposable diaper 30 were torn, the outer package 39 was stretched at the same rate in both the first region 31 and the second region 32 of the outer package 39, developed and spread out in a plane, and for each of the front and

back side portions

34a and 34b, the first region 31 and the second region 32 were cut along a straight line parallel to the width direction, and further along a straight line parallel to the front-back direction, and a rectangular sample was cut. The sample is cut out from a region of the outer package 39 other than the region facing the absorbent body 9 in plan view, that is, a region outside the region sandwiched by the extension lines of the pair of both side edge portions of the absorbent body 9 defining the width direction of the absorbent body 9. The size of the sample in the natural state after cutting was 70mm in the Y-axis direction and 50mm in the X-axis direction, as in the case of the sample preparation of the stretch panel.

(measurement method)

The cut samples of each region were fixed to the Tensilon tensile tester in the same manner as the measurement method of the stretch panel. Next, the sample was elongated at 300mm/min, and the tensile load (cN) per unit length (1mm) in the width direction when the sample was contracted to 140% after the elongation was reached to 185% of the length (inter-chuck distance) in the natural state was taken as the contraction stress. The index of 140% is to reproduce the extended state of the sample when the pants-type disposable diaper 30 is worn.

[ dimensions of the structures of the stretch panels ]

An example of specific dimensions of each structure when the stretchable panel 70 has the above-described shrinkage stress value will be described.

First, the positions shown in the respective configurations will be described with reference to fig. 17 and 20.

As shown in fig. 20, the height h of the projection 74(71) indicates the distance from the center of the elastic wire 87a to the top of the projection 74(71) in the Z-axis direction.

The width w of the projections 74(71), i.e., the length in the Y-axis direction, indicates the distance from the boundary between the projections 74(71) and the flat portions 75(72) located on both sides thereof.

The distance c between the projections 74(71) indicates the distance between the tops of the projections 74(71) adjacent to each other on the same surface side of the stretchable panel 70.

The width d of the flat portions 75(72), i.e., the length in the Y-axis direction, indicates the distance from the boundary between the respective convex portions 74(71) located on both sides of the flat portions 75(72) as viewed from the flat portions 75 (72).

As shown in fig. 20 (B), the amplitude e represents the distance between the top 81 and the bottom 82 of the corrugated stretch panel 70, and corresponds to the thickness of the corrugated stretch panel 70.

As shown in fig. 17, the arrangement interval f of the elastic wires 87a indicates the center-to-center distance between the adjacent elastic wires 87 a.

(dimensions of structures)

Since the threshold value for two-point discrimination between human fingertips is known to be about 2mm, the height h, width w, distance c, width d, amplitude e, and interval f are preferably 2mm or less in order to obtain uniformity on the surface of the stretch panel from the viewpoint of tactile sensation.

More specifically, the height h of the high protrusions 74b (71b) located in the low shrinkage stress region P2 is preferably 750 μm or more and 950 μm or less. In the present embodiment, the height h of the high convex portion 74b (71b) is 841. mu.m.

The width w of the high convex portion 74b (71b) is preferably 900 μm or more and 1100 μm or less. In the present embodiment, the width w of the high convex portion 74b (71b) is 998 μm.

The distance c between the high projections 74b (71b), i.e., the arrangement interval of the projections 74(71) of the low shrinkage stress region P2, is preferably 1400 μm or more and 1600 μm or less. In the present embodiment, the distance c between the high protrusions 74b (71b) is 1526 μm.

The width d of the flat portion 75(72) of the low shrinkage stress region P2 is preferably 500 μm or more and 750 μm or less. In the present embodiment, the width d of the flat portion 75(72) of the low shrinkage stress region P2 is 620 μm.

The amplitude e of the low shrinkage stress region P2 is preferably 350 μm or more and 600 μm or less. In the present embodiment, the amplitude e of the low shrinkage stress region P2 was 481 μm.

The height h of the low convex portion 74a (71a) located in the high shrinkage stress region P1 is preferably 450 μm or more and 650 μm or less. In the present embodiment, the height h of the low convex portion 74a (71a) is 544 μm.

The width w of the low protrusion 74a (71a) is preferably 850 μm or more and 1050 μm or less. In the present embodiment, the width w of the low convex portion 74a (71a) is 957 μm.

The distance c between the low projections 74a (71a), that is, the arrangement interval of the projections 74(71) of the high shrinkage stress region P1, is preferably 1500 μm or more and 1700 μm or less. In the present embodiment, the distance c between the low protrusions 74a (71a) is 1602 μm.

The width d of the flat portion 75(72) of the high shrinkage stress region P1 is preferably 500 μm or more and 750 μm or less. In the present embodiment, the width d of the flat portion 75(72) is 636 μm.

The amplitude e of the high shrinkage stress region P1 is preferably 350 μm or more and 600 μm or less. In the present embodiment, the amplitude e of the high shrinkage stress region P1 is 491 μm.

The arrangement interval f of the elastic wires 87a is preferably 0.5mm to 2 mm. In the present embodiment, the arrangement interval f of the elastic wires 87a is 1 mm.

In the low protrusions 74a (71a) and the high protrusions 74b (71b) respectively disposed on the same surface side of the stretch panel 70, the height of the low protrusions 74a (71a) is preferably 0.5 times or more, more preferably 0.6 times or more, further preferably 0.8 times or less, more preferably 0.7 times or less, further preferably 0.5 times or more and 0.8 times or less, more preferably 0.6 times or more and 0.7 times or less the height of the high protrusions 74b (71 b). In the present embodiment, the height of the low protrusions 74a (71a) is about 0.65 times the height of the high protrusions 74b (71 b).

In the present embodiment, the distance c between the high protrusions 74b (71b) of the low shrinkage stress region P2 is substantially the same as the distance c between the low protrusions 74a (71a) of the high shrinkage stress region P1. Since the width w of the high protrusions 74b (71b) is substantially the same as the width w of the low protrusions 74a (71a), the high-shrinkage stress region P1 of the stretch panel 70 in the natural state is substantially the same as the width in the stretching direction of the low-shrinkage stress region P2. The stretchable sheet 70 is less likely to see the boundary between the high-shrinkage-stress region P1 and the low-shrinkage-stress region P2, and has an integrated appearance. In addition, although this sheet has an integral appearance, it is a sheet that can exhibit a function in which a contraction stress varies depending on a region even when it is stretched.

In the present specification, "substantially the same" means that one value is in the range of 90% to 110% of the other value.

In the stretchable sheet 70, the ratio (h/c) of the height h of the convex portions to the distance c between the convex portions in each of the high-shrinkage-stress region P1 and the low-shrinkage-stress region P2 in each of the surfaces of the stretchable sheet 70 in the natural state is preferably 1 or less. By setting the upper limit value or less, the stretch panel 70 can have an appearance that is integrated in the nonwoven fabric surface, and the overall surface of the panel can be smoothly undulated to prevent material breakage due to hooking.

(method of measuring dimensions of each structure of stretchable sheet)

The height and width of the convex portions of the stretchable sheet 70 at the non-stretching time, the distance between the convex portions, the dimension of the width of the flat portion, the amplitude, the arrangement interval of the elastic threads 87a, and the size of the heat fusion bonded part non-existing region 65 described later were measured as follows.

Each of the dimensions can be measured by pressing the blade of a single-blade edge trimming razor (3-face.009 "/.23mm) manufactured by shin EM corporation against the stretchable sheet 70 at a strain rate of at least 100Hz to cut the sheet to obtain 5 samples, and observing the cross section of each cut sample at 20 to 100 times magnification using a microscope (VHX-1000 manufactured by KEYENCE corporation), and calculating the average value of the measurement results of the 5 samples as the dimension.

[ size of non-existing region of Heat-fused portion ]

The length of the heat-fusion-bond-absent region 65 of the stretch panel 70 in the Y axis direction is preferably 0.2mm or more, more preferably 0.4mm or more, and preferably 1.4mm or less, more preferably 1.2mm or less, and preferably 0.2mm or more and 1.4mm or less, more preferably 0.4mm or more and 1.2mm or less. In this embodiment, it is 0.79 mm.

The length of the region 65 in the X axis direction in which the heat-fusion-part does not exist is preferably 1.2mm or more, more preferably 1.4mm or more, and further preferably 2.4mm or less, more preferably 2.2mm or less, and further preferably 1.2mm or more and 2.4mm or less, more preferably 1.4mm or more and 2.2mm or less. In this embodiment 1.84 mm.

The length of the region 65 in which the heat-fusion-bonded portion is not present in the X axis direction is preferably 1.5 times or more, more preferably 1.8 times or more, and preferably 3 times or less, more preferably 2.8 times or less, and preferably 1.5 times or more and 3 times or less, more preferably 1.8 times or more and 2.8 times or less, the length in the expansion and contraction direction Y. In this embodiment, the number of times is about 2.3.

[ residual Strain of fiber of nonwoven Fabric ]

In at least one layer of the

nonwoven fabrics

85, 86 constituting the stretch panel 70, the residual strain of the fibers constituting the nonwoven fabric after 100% elongation is preferably 70% or less, more preferably 65% or less, and further preferably 50% or more, more preferably 55% or more, and preferably 50% or more and 70% or less, more preferably 55% or more, and further preferably 50% or more and 70% or less, and more preferably 55% or more and 65% or less.

At the boundary 69, shear stress is inclined with respect to the boundary 69 during elongation. In order to prevent material damage during stretching, the first nonwoven fabric 85 or the second nonwoven fabric 86 preferably has an elastic sheet capable of allowing the shear stress.

When the first nonwoven fabric 85 and the second nonwoven fabric 86 are formed using fibers having a large number of elastic-based actions with a residual strain equal to or less than the above upper limit value, the shearing stress can be allowed in the vicinity of the boundary 69 between the high-shrinkage stress region P1 and the low-shrinkage stress region P2, and material damage can be prevented from occurring during elongation.

Therefore, the residual strain of the fibers constituting at least one layer of the first nonwoven fabric 85 and the second nonwoven fabric 86 as the base material after 100% elongation is more preferably not more than the above upper limit. Such a nonwoven fabric having a small residual strain can be obtained, for example, by a spunbond method using a resin obtained by mixing an isotactic polypropylene with a propylene/ethylene/α -olefin copolymer.

Here, the synthesis of forces when virtual squares of the same size are provided on the boundary 69 as one side in each of the high shrinkage stress region P1 and the low shrinkage stress region P2 and the virtual squares in the respective regions are arranged so that the diagonal lines of the virtual squares are aligned on a straight line is examined.

When shear strain in the stretching direction is applied to the stretch panel 70, the amount of elongation occurring in the diagonal direction of the virtual square provided in the vicinity of the boundary 69 is about 1.41 times the amount of elongation occurring in the side direction of the square in the stretching direction. Therefore, the amount of inelastic operation of the fibers constituting the nonwoven fabric is allowed to be at most about 70% of a value obtained by multiplying a value obtained by dividing the length of the side of the virtual square by the length of the diagonal line of the virtual square by 100.

Therefore, in at least one layer of the first nonwoven fabric 85 and the second nonwoven fabric 86, the residual strain of the fibers constituting the nonwoven fabric after 100% elongation is preferably 70% or less, and thus material damage is less likely to occur.

(method of measuring residual Strain of fiber of nonwoven Fabric)

The measurement of the residual strain of the fibers constituting the

nonwoven fabrics

85 and 86 of the stretch sheet 70 is performed as follows.

In the region of the flat portion of the stretchable sheet 70 not including the heat-fusion bonded portion, the razor was pressed against the stretchable sheet in the same manner as the above-described measurement method of the dimensions of each configuration, and the largest rectangle was cut so that 2 sides of 4 sides were parallel to the X-axis and Y-axis directions in the range not including the heat-fusion bonded portion. The cut stretch panel member is pulled by tweezers, and the first nonwoven fabric 85 and the second nonwoven fabric 86 are peeled off from the elastic threads 87a and separated. In the stretch panel 70, the first nonwoven fabric 85, the second nonwoven fabric 86, and the elastic threads 87a are fused at the interface, and thus can be separated.

Subsequently, in the nonwoven fabric sheet of the

nonwoven fabrics

85 and 86 separated by peeling, all the fibers were pulled out by tweezers from the cross section along the X-axis direction of the stretch sheet, to obtain a fiber group. One fiber was taken out from the fiber group, and both sides of the fiber were fixed between a pair of chucks of the Tensilon tensile tester. The sample was fixed by holding the chuck with 20% of the fiber length from the end edge of each of both ends in the longitudinal direction of the sample. The chuck spacing was set to 60% of the fiber length. Further, the chuck interval is appropriately adjusted according to the length of the sample piece. The sample was elongated at an elongation of 100% in the longitudinal direction of the sample at 50mm/min, and then the elongation was gradually released to contract, and the strain (%) at which the tensile stress became 0.1cN/mm was determined. The sample was elongated at a speed of 50mm/min, and the elongation at which the elongation of the sample was stopped was determined as the maximum point elongation (%). The residual strain (%) is a value obtained by multiplying the strain at which the tensile stress became 0.1cN/mm by the value of the elongation at the maximum point by 100. This measurement was performed on all of the fiber groups, and the residual strain was obtained, and the average value thereof was taken as the residual strain of the fibers constituting the nonwoven fabric.

[ residual Strain of elastic yarn ]

When the stretch panel 70 is applied to the outer package 39 of the diaper 30, the elastic yarn 87a preferably has a residual strain of 60% or less after 6 hours 100% elongation at a temperature of 40 ℃. And preferably 50% or more. Here, 40 ℃ is a temperature close to the body temperature of the wearer of the disposable diaper when the stretch panel 70 is applied to the outer package of the disposable diaper, and is therefore set to a temperature close to the environment in which the disposable diaper is used in practice.

By using the elastic thread 87a having little stress relaxation in which the residual strain after the 100% elongation is applied for 6 hours at 40 ℃ is 60% or less, the stretchability of the stretch sheet 70 can be maintained. This can provide a comfortable wearing feeling to the wearer.

When only the elasticity of the elastic wire 87a is concerned, the lower limit of the residual strain is not limited.

(method of measuring residual Strain of elastic yarn)

The measurement of the residual strain of the elastic wire described above was performed as follows.

The stretch sheet member is cut out from the stretch sheet 70 by the same method as the method for measuring the residual strain of the fibers of the nonwoven fabric, and the

nonwoven fabrics

85, 86 are separated from the elastic threads 87 a.

Subsequently, the separated elastic yarn 87a was cut into a length of 10mm, and 5 samples were prepared. Both sides of the cut sample in the longitudinal direction were fixed between a pair of chucks of the Tensilon tensile testing machine. The sample was fixed by clamping the portions of the sample having a width of 2.5mm from the end edges at both ends in the longitudinal direction thereof to a chuck at a pressure of at least 1 MPa. The chuck spacing was set at 5mm and the samples were fixed in the natural state. Further, the chuck interval is appropriately adjusted according to the length of the sample piece. The sample was allowed to stand at 40 ℃ for 6 hours in a state of being elongated at 50mm/min in the longitudinal direction of the sample to 100% elongation. Then, the elongation was released and the sample was contracted, and the elongation at which the tensile stress became 0 was measured to determine the residual strain.

[ recovery from elongation and elongation of stretchable sheet and non-stretchable sheet ]

The outer package 39 of the disposable diaper 30 described above has the first sheet 44 as an extensible sheet and the second sheet 12 as a non-extensible sheet. The stretch nonwoven fabric is a nonwoven fabric having a recovery rate (elongation recovery rate) of 70% or more when 100% elongation is performed at least in the same direction as the contraction direction. The stretch nonwoven fabric used in the present embodiment preferably has an elongation of 100% or more, and more preferably 150% or more.

The elongation recovery and elongation can be measured as follows.

(measurement of elongation recovery)

A sample piece of a stretch panel having a length of 50mm and a width of 25mm was prepared, and the sample piece was fixed at a chuck interval of L0 using the Tensilon tensile tester, stretched at a speed of 300mm/min to a length L2 at 100% elongation (L2 ═ L0 × 2), and then returned at the same speed as the stretching speed, and the length of the sample piece at which the tensile load became 0 was set to a length L1 after recovery of elongation. The elongation recovery at 100% elongation was calculated according to the following formula.

Elongation recovery rate at 100% elongation (%) { (L2-L1)/(L2-L0) } × 100

(method of measuring elongation)

A sample piece having the same size as the sample piece used in the method for measuring the elongation recovery rate was elongated under the same conditions as the measurement of the elongation recovery rate, and the elongation at the time of fracture was defined as the elongation.

< ninth embodiment >

The stretch panel 99 of the present embodiment will be described with reference to fig. 28. Note that the same components as those in the above-described embodiments are denoted by the same reference numerals, and description thereof may be omitted.

Fig. 28 is a schematic sectional view of the stretch panel 99. Fig. 28 is a view showing a state in which the boundary surface between the first nonwoven fabric 85 and the second nonwoven fabric 86 is spread in a planar shape so that the undulation of the elastic thread 87a is straightly extended in a state in which the elastic thread 87a is not extended.

The stretch panel 70 of the first embodiment is configured such that the convex portion 71 of one surface is disposed opposite to the convex portion 74 of the other surface in the thickness direction.

In contrast, as shown in fig. 28, the stretchable sheet 99 of the ninth embodiment is configured such that the convex portion 71 of one surface is provided at a position between the adjacent

convex portions

74 and 74, and the convex portion 71 of the other surface is provided so as to face the convex portions in the thickness direction.

In the stretch sheet 99, the convex portion 74 of the first nonwoven fabric 85 is positioned at the stretch portion 95 of the first nonwoven fabric 85, and the flat portion 75 is positioned at the connection portion 96. The convex portions 71 of the second nonwoven fabric are located at the stretch portions 97 of the second nonwoven fabric 86, and the flat portions 72 are located at the connection portions 98. The projection 74 (projection 71) has a length in the Y axis direction longer than the flat portion 75 (flat portion 72).

In the present embodiment, the stretchable section 95 of the first nonwoven fabric 85 and the stretchable section 97 of the second nonwoven fabric 86 are provided so as to partially face each other in the thickness direction. The stretch units 95 of the first nonwoven fabric 85 face the joint 98 of the second nonwoven fabric 86 and a part of each of the

stretch units

97 and 97 adjacent to the joint 98 and located on both sides thereof in the thickness direction.

That is, in the stretch panel 99, the region where the connecting portions 96 of the first nonwoven fabric 85 are not arranged and the region where the connecting portions 98 of the second nonwoven fabric 86 are arranged face each other in the thickness direction. In other words, the stretch panel 99 has a structure in which there is no region having only the connection portion in the XY plane.

Here, the connection portions 96(98) are necessary to fix the first nonwoven fabric 85 (second nonwoven fabric 86) and the elastic threads 87a, but the stretchability is not exhibited in the connection portions 96 (98).

In the stretch panel 99 of the present embodiment, since the flat portion (connecting portion) of the other surface is provided so as to face the convex portion (stretchable portion) of the one surface in the thickness direction, the convex portion (stretchable portion) can exhibit stretchability even in the region where the convex portion of the one surface faces the flat portion of the other surface while canceling out the influence of non-stretchability exhibited by the flat portion (connecting portion). This can exhibit extensibility in the Y-axis direction over the entire XY plane.

In the present embodiment, as in the first embodiment, the convex portions 74 and the convex portions 71 have high convex portions and low convex portions, respectively, and have the same dimensions as in the first embodiment. In the stretchable sheet 99 having the high convex portions and the low convex portions, the regions where the high convex portions are arranged face each other are the low shrinkage stress regions P2, and the regions where the low convex portions are arranged are the high shrinkage stress regions P1.

The stretch panels 99 having different contraction stresses can be applied to the outer package of a disposable diaper and the like, as with the stretch panel 70 of the first embodiment.

Other embodiments of the stretchable sheet

While the embodiments of the present invention have been described above, the present invention is not limited to the above-described embodiments, and it is needless to say that various modifications can be made within the scope not departing from the gist of the present invention.

For example, in the stretch panel 70 of the first embodiment, the center in the Y axis direction of the convex portion 74 disposed on one surface is substantially aligned with the center in the Y axis direction of the convex portion 71 disposed on the other surface opposite to the convex portion 74 in the thickness direction. In the stretchable sheet 99 of the second embodiment, the center in the Y axis direction of the convex portion 74 formed on one surface substantially coincides with the center in the Y axis direction of the flat portion 72 disposed on the other surface facing the convex portion 74 in the thickness direction. However, the arrangement positions of the convex portions 74 and the convex portions 71 are not limited to this.

As another example, the convex portion 71 on the other surface and the flat portion 72 adjacent to one surface thereof may be disposed to face the convex portion 74 disposed on the one surface in the thickness direction. In this case, the center in the Y axis direction of the convex portion 74 disposed on one surface is located between the center in the Y axis direction of the flat portion 72 disposed to face the convex portion 74 and the center in the Y axis direction of the convex portion 71. In this configuration, the projecting portion is formed of the high projecting portion and the low projecting portion, whereby the stretchable sheet having high shrinkage stress and low shrinkage stress can be obtained. The positional relationship between the convex portion on one surface and the convex portion on the other surface can be adjusted by changing the positions of the teeth engaged with each of the

slot stretching rollers

91 and 92.

In the above-described embodiment of the disposable diaper, the outer cover is formed using the first sheet and the second sheet, but the outer cover may be formed using only the first sheet. As the first sheet, the stretchable sheet 70 or the stretchable sheet 99 described above can be used.

In the above embodiments, both the ventral portion and the dorsal portion of the waist portion have the stretchable region, but at least one of the ventral portion and the dorsal portion may have the stretchable region.

In the disposable diaper according to the first embodiment, a composite sheet in which a first sheet (stretchable sheet) and a second sheet (non-stretchable sheet) are laminated is used in the waist portion of the outer covering, and when the disposable diaper is applied, the first sheet as the stretchable sheet is disposed on the outer surface side and the second sheet is disposed on the inner surface side.

In the disposable diaper, a part of the elastic member of the stretchable sheet in the region facing the absorbent body in the waist portion may be cut or removed to form a non-stretchable region. This prevents the absorbent body from being wrinkled due to contraction of the stretchable sheet, and thus does not hinder the liquid-absorbing performance of the absorbent body.

The outer package of the disposable diaper according to the first embodiment is composed of a seamless sheet in which the front and back side portions are connected to each other via the crotch portion. In contrast, the stretchable sheet of the present invention can be used for the outer package 59 separated from the front and back sides as in the disposable diaper 45 shown in fig. 29. The outer package 59 includes a composite sheet 49 including a ventral portion 53a, a dorsal portion 53b, an adhesive layer 13, and

second sheets

12a and 12 b. The

stretch panels

70 and 99 of the present invention can be applied to the front and

back side portions

53a and 53b, and a diaper 45 having stretchability in the waistline portion can be obtained.

The absorbent article of the present invention may be a pants-type disposable diaper formed in advance in a pants shape, without being joined by side seals as in the above-described embodiment. That is, the pants-type absorbent article of the present invention may be a tape type disposable diaper in which a tape such as a fastening material is provided instead of the side seal portion.

The absorbent article of the present invention may be a disposable diaper for adults and children, for example, instead of the disposable diaper for infants and children. The absorbent article of the present invention may not be a disposable diaper as long as it is a type of absorbent article to be worn on the lower body. Examples of such absorbent articles include pants-type sanitary napkins and pants-type urine receiving pads.

The present invention also discloses the following absorbent article according to the above embodiment.

< 1 > a pants-type absorbent article having: an absorbent body positioned in the crotch portion; a waist portion having a ventral portion and a dorsal portion located at a waist-body portion; and a crotch portion located between the front portion and the back portion and holding the absorber together with the front portion and the back portion, wherein the pants-type absorbent article,

at least one of the ventral portion and the dorsal portion includes a stretch panel comprising: a first region; and a second region located on the upper side of the first region in the vertical direction orthogonal to the circumferential direction of the waist portion,

the stretchable sheet includes an elastic resin and a nonwoven fabric layer containing the elastic resin, the circumferential contraction stress of the first region and the circumferential contraction stress of the second region are different from each other, and the first region and the second region have the same dimensions in the circumferential direction in a natural state.

< 2 > the pants-type absorbent article according to the above < 1 >, wherein,

the stretch panel has:

a first sheet comprising the nonwoven layer containing the elastic resin;

a second sheet comprising a non-stretch nonwoven opposite the first sheet; and

an adhesive layer bonding the first sheet to the second sheet.

< 3 > the pants-type absorbent article according to the above < 2 >, wherein,

the second sheet has a plurality of raised portions raised to the opposite side of the first sheet, the raised portions forming a series of patterns,

the adhesive layer is disposed across the first region and the second region.

< 4 > the pants-type absorbent article according to the above < 3 >, wherein,

the adhesive layers are arranged at intervals in the circumferential direction, and have a plurality of adhesive portions arranged continuously or discontinuously in one direction across the first region and the second region.

< 5 > the pants-type absorbent article according to the above < 4 >, wherein,

the plurality of bonding portions are arranged continuously or discontinuously along the vertical direction.

< 6 > the pants-type absorbent article according to the above < 4 >, wherein,

the plurality of bonding portions are arranged in a staggered manner.

< 7 > the pants-type absorbent article according to the above < 1 >, wherein,

the stretch panel includes a first sheet formed of the nonwoven fabric layer containing the elastic resin therein.

< 8 > the pants-type absorbent article according to any one of the above < 1 > to < 7 >, wherein,

the shrinkage stress of the first region is higher than the shrinkage stress of the second region.

< 9 > the pants-type absorbent article according to any one of the above < 1 > -to < 8 >, wherein,

the weight of the elastic resin per unit area of the first region is greater than the weight of the elastic resin per unit area of the second region.

< 10 > the pants-type absorbent article according to any one of the above < 1 > -to < 8 >, wherein,

the elastic resin is composed of a plurality of elastic fibers,

the plurality of elastic fibers of the first region have a higher density than the plurality of elastic fibers of the second region.

< 11 > the pants-type absorbent article according to any one of the above < 1 > to < 8 >, wherein,

the elastic resin is composed of a plurality of elastic fibers,

the plurality of elastic fibers of the first region have a larger denier than the plurality of elastic fibers of the second region.

< 12 > the pants-type absorbent article according to any one of the above < 1 > to < 8 >, wherein,

the elastic resin is composed of a plurality of elastic wires continuously arranged in the stretching direction,

the plurality of elastic wires are arranged along the circumferential direction at intervals in the vertical direction,

the arrangement interval of the plurality of elastic wires in the first region is smaller than the arrangement interval of the plurality of elastic wires in the second region.

< 13 > the pants-type absorbent article according to the above < 12 >, wherein,

the plurality of elastic filaments in the first and second regions have the same denier.

< 14 > the pants-type absorbent article according to any one of the above < 1 > to < 13 >, wherein,

the stretch panel further includes a third region located at an edge portion on an upper side in the vertical direction and formed by folding back the stretch panel toward a lower side in the vertical direction,

the contraction stress in the circumferential direction of the third region is the same as the contraction stress in the circumferential direction of the first region, or is lower than the contraction stress in the circumferential direction of the first region and higher than the contraction stress in the circumferential direction of the second region.

< 15 > the pants-type absorbent article according to the above < 14 >, wherein,

the vertical length of the third region is 1/2 or less of the vertical length of the second region.

< 16 > the pants-type absorbent article according to the above < 14 > or < 15 >, wherein,

the pants-type absorbent article further includes an elastic body disposed in the third region in the circumferential direction inside the folded-back stretchable panel.

< 17 > the pants-type absorbent article according to any one of the above < 1 > to < 16 >, wherein,

the first region preferably has a shrinkage stress of 1.4cN/mm or more, more preferably 2cN/mm or more, further preferably 5cN/mm or less, and preferably 1.4cN/mm or more and 5cN/mm or less, more preferably 2cN/mm or more and 5cN/mm or less.

< 18 > the pants-type absorbent article according to any one of the above < 1 > -17, wherein,

the second region preferably has a shrinkage stress of 0.1cN/mm or more, more preferably 0.5cN/mm or more, and preferably 3cN/mm or less, more preferably 2.5cN/mm or less, and preferably 0.1cN/mm or more and 3cN/mm or less, more preferably 0.5cN/mm or more and 2.5cN/mm or less.

< 19 > the pants-type absorbent article according to any one of the above < 14 > to < 16 >, wherein,

the shrinkage stress of the third region is preferably 1.4cN/mm or more, more preferably 1.5cN/mm or more, and is preferably 4cN/mm or less, more preferably 3.5cN/mm or less, and is preferably 1.4cN/mm or more and 4cN/mm or less, more preferably 1.5cN/mm or more and 3.5cN/mm or less.

< 20 > the pants-type absorbent article according to any one of the above < 1 > -19 >, wherein,

the shrinkage stress of the first region is preferably 1.2 times or more, more preferably 1.4 times or more, and further preferably 3 times or less, more preferably 2.5 times or less, and further preferably 1.2 times or more and 3 times or less, more preferably 1.4 times or more and 2.5 times or less, the shrinkage stress of the second region.

< 21 > the pants-type absorbent article according to any one of < 14 > - < 16 > and < 19 > wherein,

the shrinkage stress of the first region is preferably 1.1 times or more, more preferably 1.5 times or more, and further preferably 2.5 times or less, more preferably 2 times or less, and further preferably 1.1 times or more and 2.5 times or less, more preferably 1.5 times or more and 2 times or less, of the shrinkage stress of the third region.

< 22 > the pants-type absorbent article according to any one of the above < 1 > -21 >, wherein,

the length of the first region in the vertical direction is preferably 1.0 times or more, more preferably 1.2 times or more, further preferably 2 times or less, more preferably 1.8 times or less, and further preferably 1.0 times or more and 2 times or less, more preferably 1.2 times or more and 1.8 times or less the length of the second region.

< 23 > the pants-type absorbent article according to any one of < 14 > - < 16 >, < 19 >, < 21 > above, wherein,

the length of the third region in the vertical direction is preferably 0.5cm or more, more preferably 5cm or less, even more preferably 3cm or less, even more preferably 1.5cm or less, and is preferably 0.5cm or more and 5cm or less, more preferably 0.5cm or more and 3cm or less, even more preferably 0.5 to 1.5cm or less.

< 24 > the pants-type absorbent article according to the above < 16 >, wherein,

the elastic body is disposed on the ventral portion and the dorsal portion over the entire width in the circumferential direction, in a natural state in which no tension is applied, and in a length equal to or greater than the width of each of the ventral portion and the dorsal portion in the natural state in the circumferential direction.

< 25 > a stretch panel having: a plurality of elastic wires capable of being stretched in a first direction; and two layers of nonwoven fabrics welded to the elastic threads and arranged to face each other with the elastic threads interposed therebetween, wherein in the stretch sheet,

the nonwoven fabric has: a plurality of projections arranged at intervals along the first direction and extending in a second direction orthogonal to the first direction; and a flat portion disposed between the convex portions adjacent to each other among the plurality of convex portions, and extending in the second direction,

< 26 > the stretch panel according to the above < 25 >, wherein,

at least one of the two layers of the nonwoven fabric contains fibers having a residual strain of 70% or less after 100% elongation is applied.

< 27 > the stretch panel according to the above < 25 > or < 26 >, wherein,

at least one of the two nonwoven fabrics is a fiber having a residual strain of 50% to 70% after 100% elongation of the fiber constituting the nonwoven fabric.

< 28 > the stretch panel according to < 26 > or < 27 > above, wherein,

the fiber has a residual strain after 100% elongation is applied of 55% or more and 65% or less.

< 29 > the stretch panel according to any one of the above < 25 > to < 28 >, wherein,

the elastic yarn has a residual strain of 60% or less after applying 100% elongation for 6 hours under a temperature condition of 40 ℃.

< 30 > the stretch panel according to any one of the above < 25 > to < 29 >, wherein,

the elastic yarn has a residual strain of 50% or more and 60% or less after applying 100% elongation for 6 hours under a temperature condition of 40 ℃.

< 31 > the stretch panel according to any one of the above < 25 > to < 30 >, wherein,

the stretchable sheet has a low shrinkage stress region for disposing the second convex portion and a high shrinkage stress region for disposing the first convex portion,

the nonwoven fabric has a plurality of heat-fused parts formed by heat-fusing a plurality of fibers constituting the nonwoven fabric,

in a region where the rectangular heat-fusion-bonded portion is not present, each side in contact with the heat-fusion-bonded portion, which is surrounded by the heat-fusion-bonded portion arranged adjacent to the boundary between the high-shrinkage-stress region and the low-shrinkage-stress region and the heat-fusion-bonded portion arranged adjacent to each other in the second direction with the boundary interposed therebetween, is parallel to the boundary or an imaginary line orthogonal to the boundary, and the length in the second direction is longer than the length in the first direction.

< 32 > the stretch panel according to the above < 31 >, wherein,

the length of the region where the heat-fusion-bonded part is not present in the second direction is 1.5 times or more and 3 times or less the length in the first direction.

< 33 > the stretch panel according to the above < 31 >, wherein,

the length of the region where the heat-fusion-bonded part is not present in the second direction is 1.8 times or more and 2.8 times or less the length in the first direction.

< 34 > the stretch panel according to any one of the above < 25 > to < 33 >, wherein,

the low shrinkage stress region has a lower shrinkage stress per unit length in the first direction than the high shrinkage stress region.

< 35 > the stretch panel according to any one of the above < 25 > to < 34 >, wherein the stretch panel is a continuous panel having no seam in a planar direction.

< 36 > the stretch panel according to any one of the above < 25 > to < 35 >, wherein the elastic yarn is directly welded to the nonwoven fabric.

< 37 > the stretch panel according to any one of the above < 25 > to < 36 >, wherein a boundary surface between two layers of the nonwoven fabric in the stretch panel has a waveform.

< 38 > the stretch panel according to any one of the above < 25 > -37 >, wherein the fibers constituting the convex portions are peeled off from the elastic thread.

< 39 > the stretch panel according to any one of the above < 25 > -38 >, wherein the fiber density of the convex portion is lower than the fiber density of the flat portion.

< 40 > the stretch panel according to any one of the above < 25 > to < 39 >, wherein,

the projecting portion of one surface of the stretchable sheet is provided at the position of the projecting portion of the other surface in the thickness direction, and the non-projecting portion of the other surface is provided at the position of the flat portion of the one surface.

< 41 > the stretch panel according to any one of the above < 25 > -to < 40 >, wherein the plurality of projections are provided continuously along the second direction without interruption.

< 42 > the stretch panel according to any one of the above < 25 > to < 41 >, wherein,

the height of the first convex part is more than 0.5 times and less than 0.8 times of the height of the second convex part.

< 43 > the stretch panel according to any one of the above < 25 > -42 >, wherein,

the height of the first convex part is more than 0.6 times and less than 0.7 times of the height of the second convex part.

< 44 > the stretch panel according to any one of the above < 25 > to < 43 >, wherein,

the ratio of the height of the projections to the distance between the projections (height of projections/distance between projections) is 1 or less.

< 45 > the stretch panel according to any one of the above < 25 > -44 >, wherein,

the convex portion constitutes an extensible portion extensible in the first direction,

the flat portion constitutes a connecting portion that is less likely to expand and contract in the first direction than the expanding and contracting portion.

< 46 > an absorbent article comprising the stretch panel according to any one of the above < 25 > to < 45 >.

< 47 > the absorbent article according to the above < 46 >, wherein,

the absorbent article includes:

an absorbent body positioned in the crotch portion;

a waist portion having a front side portion and a back side portion which are positioned in a waist portion, at least one of the front side portion and the back side portion being formed using the stretchable sheet which is stretchable in a circumferential direction of the waist portion; and

a crotch portion that is located between the front side portion and the back side portion and holds the absorbent body together with the front side portion and the back side portion,

in the waist portion having the stretch panel, the first convex portion is disposed in a central region located at the center of regions obtained by trisecting the waist portion in a direction orthogonal to the circumferential direction, and the second convex portion is disposed in at least one of a pair of end regions provided so as to face each other with the central region interposed therebetween.

< 48 > the absorbent article according to the above < 47 >, wherein,

the second convex portion is disposed in both of a pair of end regions provided opposite to each other with the central region interposed therebetween in the waist portion including the stretch panel.

< 49 > the absorbent article according to any one of the above < 46 > -48 >, wherein,

the absorbent article includes an outer body and the absorbent body,

the outer package body has the stretchable sheet.

< 50 > the absorbent article according to the above < 49 >, wherein,

the outer package body includes the stretch sheet and a base sheet,

the stretch panel and the base material sheet are joined without an elastic body.

< 51 > the absorbent article according to any one of the above < 46 > -50 >, wherein,

the absorbent article is a disposable diaper for infants.

< 52 > a method for producing a stretch panel, comprising:

a step of supplying heated elastic yarns between the first nonwoven fabric and the second nonwoven fabric and applying pressure to laminate the elastic yarns to obtain a laminate; and

a stretching step of performing a roll stretching process by passing the laminate through a pair of grooved stretching rolls,

the cogging draw rolls have a high tooth height portion and a low tooth height portion having a tooth height lower than the high tooth height portion.

< 53 > the process for producing a stretch panel according to the above < 52 >, wherein,

the tension applied to the stretchable sheet after the stretching step is made weaker than the tension applied to the laminate before the stretching step.

< 54 > a method for producing an absorbent article, comprising:

a step of obtaining an outer package by bonding the stretch sheet produced by the production method described in the above < 52 > or < 53 > to a base sheet while stretching the stretch sheet at a constant elongation; and

and a step of overlapping the absorbent body with the outer package.

< 55 > the method for producing an absorbent article according to the above < 54 >, wherein,

the stretch panel and the base material sheet are joined without an elastomer.

Industrial applicability

According to the present invention, the appearance and touch of shorts (cloth) close to underwear can be presented while maintaining the fit and the basic performance as a diaper. Further, according to the present invention, a stretchable sheet having regions with different shrinkage stresses can be obtained.

Claims

1. A pants-type absorbent article having: an absorbent body positioned in the crotch portion; a waist portion having a ventral portion and a dorsal portion located at a waist-body portion; and a crotch portion located between the front portion and the back portion and holding the absorber together with the front portion and the back portion, the pant-type absorbent article being characterized in that:

the stretchable sheet comprises an elastic resin and a nonwoven fabric layer containing the elastic resin, the contraction stress in the circumferential direction of the first region and the contraction stress in the circumferential direction of the second region are different from each other, the dimensions in the circumferential direction of the first region and the second region in a natural state are equal to each other,

the elastic resin is composed of an elastic wire,

the stretch panel has: a plurality of the elastic wires capable of being stretched in a first direction; and two layers of nonwoven fabrics welded to the elastic threads and arranged to face each other with the elastic threads interposed therebetween,

2. The pant-type absorbent article according to claim 1, wherein:

3. A pant-type absorbent article according to claim 1 or 2, wherein:

4. A pant-type absorbent article according to claim 1 or 2, wherein:

the density of the plurality of elastic wires of the first region is higher than the density of the plurality of elastic wires of the second region.

5. A pant-type absorbent article according to claim 1 or 2, wherein:

the titer of the plurality of elastic filaments of the first region is greater than the titer of the plurality of elastic filaments of the second region.

6. A pant-type absorbent article according to claim 1 or 2, wherein:

7. The pant-type absorbent article according to claim 6, wherein:

the titer of the plurality of elastic filaments in the first and second regions is the same.

8. A pant-type absorbent article according to claim 1 or 2, wherein:

9. The pant-type absorbent article according to claim 8, wherein:

10. The pant-type absorbent article according to claim 8, wherein:

11. A stretch panel, comprising: a plurality of elastic wires capable of being stretched in a first direction; and two layers of nonwoven fabrics welded to the elastic threads and disposed to face each other with the elastic threads interposed therebetween, the stretch panel being characterized in that:

12. The expansion tab of claim 11 wherein:

13. The stretch panel of claim 11 or 12, wherein:

14. The stretch panel of claim 11 or 12, wherein:

15. The stretch panel of claim 11 or 12, wherein:

16. An absorbent article characterized by:

comprising a stretch panel according to any one of claims 11 to 15.

17. The absorbent article of claim 16, wherein:

the absorbent article includes:

an absorbent body positioned in the crotch portion;

18. A method of making a stretchable sheet, comprising:

a step of supplying heated elastic threads which can stretch and contract in a first direction between the first nonwoven fabric and the second nonwoven fabric, and applying pressure to laminate the elastic threads to obtain a laminate; and

the cogging draw rolls have high tooth height portions and low tooth height portions having a tooth height lower than the high tooth height portions,

the high tooth height portion and the low tooth height portion of the slot draw roll are set at positions such that the laminate after the roll drawing process in the drawing step becomes a stretchable sheet having a structure including: a plurality of projections arranged at intervals along the first direction and extending in a second direction orthogonal to the first direction; and a flat portion which is disposed between the convex portions adjacent to each other among the plurality of convex portions, extends in the second direction, and has a first convex portion and a second convex portion which are different from each other in height in the second direction, and the height of the second convex portion is higher than the height of the first convex portion.