JP6025153B2 - Pants-type disposable diaper - Google Patents

Description

  The present invention relates to a pants-type disposable diaper having an exterior sheet having both fit, thinness and flexibility.

The pants-type disposable diaper includes an exterior sheet having a front body and a back body, and an interior body including an absorbent body fixed to the inner surface of the exterior sheet, and the front body and the back body of the exterior sheet are on both sides. Are joined together to form a waist opening and a pair of left and right leg openings.
In the pants-type disposable diaper, in order to improve the fit to the body, various elastic members are fixed to the exterior sheet in an expanded state (see, for example, Patent Documents 1 to 7). The one provided with the waist elastic member, the waist elastic member, and the curved elastic member (represented in Patent Document 6) has a relatively high fit to the body. Here, a plurality of waist elastic members are arranged in parallel along the width direction at intervals in the vertical direction at the edge of the waist opening. Further, the waist elastic member is disposed along the width direction with a space in the longitudinal direction in a region closer to the center in the front-rear direction than the waist elastic member. Furthermore, the curved elastic member extends while curving from both side portions of at least one of the front body and the back body so as to go to the opposite body side toward the center in the width direction.

However, in the conventional general pants-type disposable diapers, there is a problem that the crotch part is mokomoko unlike ordinary underwear. And according to the study by the present inventors, one of the causes of this problem is that the absorbent body floats from the body in the part from the rupture to the crotch, that is, the fit at the part is insufficient. Met.
In order to improve the fit of the crack, there are various forms such as an arrangement in which the curved elastic member on the back side protrudes convexly toward the waist opening at the crotch crossing part. Although it has been proposed (see, for example, Patent Documents 8 and 9), the inner surface of the diaper has a shape that fits the rupture, but it is difficult to maintain the diaper fit, and the fit from the rupture to the crotch tends to be insufficient. In addition to the above problems, when attaching an elastic member in manufacturing, it is necessary to change the direction of the elastic member to a steep angle, which makes it difficult to manufacture with a high-speed line.

JP-A-7-265357 JP-A-7-299094 JP-A-11-36103 JP 2001-258931 A JP 2001-204762 A JP 2006-043415 A Special table 2007-113978 gazette JP 2007-97621 A JP 2008-253289 A

  Then, the main subject of this invention is providing the underpants type disposable diaper which improves the fitting property from a rupture to a crotch, and a crotch part is hard to mokomoko at the time of mounting | wearing.

The present invention that has solved the above problems is as follows.
<Invention of Claim 1>
An exterior sheet that forms a front body and a back body, and an interior body including an absorbent body that is fixed to an inner surface of the exterior sheet, and both sides of the exterior sheet in the front body and both sides of the exterior sheet in the back body And pants type disposable diapers in which a waist opening and a pair of left and right leg openings are formed,
A bent fitting part that is bent so as to enter the wearer's crack is provided in the crack facing part in the back body,
The exterior sheet in the front body and the exterior in the back body as a pulling elastic member that exerts a contraction force of a longitudinal component so that the crotch portion is lifted to the waist side in each of the exterior sheet in the front body and the exterior sheet in the back body In each of the sheets, an elongated curved elastic member that extends while being curved toward the opposite body side from the both sides toward the center in the width direction is stretched at a predetermined elongation rate in the extending direction. Fixed,
In each of the exterior sheet in the front body and the exterior sheet in the back body, a plurality of elongated waist elastic members extending along the width direction are spaced apart in the longitudinal direction at the edge of the waist opening, respectively. Elongated waist elastic that is fixed in a state of being stretched at a predetermined stretch rate along the width direction and extends along the width direction in a region closer to the center in the front-rear direction than the waist elastic member A plurality of members are fixed in a state where they are stretched at a predetermined stretch rate along the width direction at intervals in the longitudinal direction,
The outer sheet is at least the waist elastic member, the portion having the waist elastic member, and the curved elastic member comprises an adhesive laminating a plurality of nonwoven fabrics, and the waist during the non-woven fabric of the outer sheet part elastic members, waist elastic members, and the curved elastic members are fixed,
Elastic deformation at 80% elongation in the longitudinal direction in the front body due to at least one of the thickness, elongation rate, and number of the curved elastic members being different between the curved elastic member in the front body and the curved elastic member in the back body The tensile stress at time is 1.1 times or more of the tensile stress at the time of elastic deformation at 80% elongation in the longitudinal direction in the back body.
A pants-type disposable diaper characterized by that.

(Function and effect)
Simply providing a bent fitting part does not necessarily provide a sufficient fit for a rupture, but as described above, a pulling elastic member is provided on the front and back bodies to provide tensile stress during elastic deformation in the longitudinal direction in the front body. If it is larger than that of the back body, the crotch part of the diaper is lifted while moving to the front side due to the contraction force of the pulling elastic member of the front body against the contraction force of the pulling elastic member of the back body in the mounted state. The crotch fits, and the front end portion of the bent fit portion is pulled forward, and as a result, the bent fit portion fits the crack while maintaining the bent state. Therefore, according to this invention, while fitting well from a rupture to a crotch, the fit follows the movement of a body and is maintained elastically, and a crotch part becomes difficult to mokomoko at the time of mounting | wearing.
The curved elastic member is preferable because it improves the fit to the buttock in the front body, improves the fit to the bulge of the buttock in the back body, and functions as the pulling elastic member of the present invention.
Furthermore, if it is configured to perform circumferential tightening by the waist elastic member and waist elastic member along the width direction, a sufficient circumferential tightening force can be secured, and the contracting action of the curved elastic member can be reliably demonstrated with this as a support. In addition, it is preferable because the contraction force of the waist elastic member and the waist elastic member hardly adversely affects the balance action of the curved elastic member.

<Invention of Claim 2>
A crack elastic member is provided on the back body so that a contraction force in the width direction acts on the crack facing portion of the crack facing portion and portions located on both sides thereof. The pants-type disposable diaper according to claim 1, wherein the bent fitting portion is formed by a contracting action of a member.

(Function and effect)
The bent fitting portion can be formed by providing a groove or a slit in the absorbent body. However, it is preferable to form the bent fitting portion with the above-described cracked portion elastic member because elastic fit is obtained.

<Invention of Claim 3>
The crack part elastic member is an elongated elastic member extending across the crack facing part in the width direction, and the crack facing part of the crack facing part and portions located on both sides thereof The pants-type disposable diaper according to claim 2, wherein portions positioned on both side portions are finely cut so that a contractile force acts on the diaper.

(Function and effect)
Thus, by forming the cracked part elastic member with the elongated elastic member extending across the crack facing part in the width direction, not only can it be manufactured at a low cost, but the cracked part elastic member is conventionally produced at the time of manufacturing. Thus, there is no need to change to a steep angle, and there is an advantage that the high-speed line can be manufactured stably.

<Invention of Claim 4>
The contraction force acting portion of the cracked portion elastic member has a width that increases from the front end of the crack facing portion to the middle in the front-rear direction toward the rear side, and further to the rear side, the width further toward the rear side. The pants-type disposable diaper according to claim 3, which has a reduced shape.

(Function and effect)
By forming the contraction force acting part of the cracked part elastic member in such a shape, a bent fitting part that fits suitably to the crack can be formed.

<Invention of Claim 5>
The groove | channel or slit which follows a crack is formed in the crack opposing part in the said absorber, The said bending | flexion fitting part is formed using this groove | channel or slit as a crease | fold, The any one of Claims 1-4. The pants-type disposable diaper described in 1.

(Function and effect)
By forming such a groove or slit, a bent fit portion is formed with an appropriate position as a crease, and the shape is maintained well.

<Invention of Claim 6>
The curved elastic member in the front body and the curved elastic member in the back body are arranged in parallel with a predetermined interval, respectively.
The longitudinal direction interval of the curved elastic member in the back body is wider than the longitudinal direction interval of the curved elastic member in the front body at a portion on the outer side in the width direction from the side edge of the interior body. The pants-type disposable diaper described in 1.

(Function and effect)
In this way, a plurality of curved elastic members are arranged side by side at a predetermined interval, and at the portion on the outer side in the width direction from the side edge of the interior body, the interval between the curved elastic members on the rear body is relatively widened, By relatively narrowing the interval between the curved elastic members at the time, the fitting property that enters the buttocks by the curved elastic member at the front body is exhibited, and the bulge of the buttocks is wrapped by the curved elastic member at the back body In addition to exhibiting the fit, the above-described action of the present invention makes it difficult for the bending fit portion to bite into the crack when it fits into the crack while maintaining its bent state.

  As described above, according to the present invention, the fit property from the crack to the crotch is improved, and the crotch portion is less likely to be bent when worn.

It is a top view (inner surface side) of the underpants type disposable diaper of a deployment state. It is a top view (outer surface side) of the underpants type disposable diaper of a deployment state. It is a principal part top view of the underpants type disposable diaper of an unfolded state. It is CC sectional drawing of FIG. It is AA sectional drawing of FIG. It is BB sectional drawing of FIG. It is a top view which shows an adhesive agent application pattern. It is a top view which shows an elastic member cut pattern. It is a perspective view of the wearing state of a pants type disposable diaper. It is a rear view of the wearing state of a pants type disposable diaper. It is DD sectional drawing of FIG. It is a rear view of the wearing state of the conventional pants type disposable diaper. It is a graph which shows the test result of MIU / MMD and a twist degree. It is a graph which shows the test result of a twist degree and a bending resistance. It is a graph which shows the test result of compression hardness LC, compression work WC, compression resilience RC, and bending resistance.

Hereinafter, an embodiment of the present invention will be described in detail with reference to the accompanying drawings.
1-11 has shown the underpants type disposable diaper 1 of embodiment. The pants-type disposable diaper 1 (hereinafter also simply referred to as a diaper) includes an exterior sheet 20 that forms a front body F and a back body B, and an interior body 10 that is fixed and integrated with the inner surface of the exterior sheet 20. The interior body 10 is formed by interposing an absorber 13 between a liquid-permeable top sheet 11 and a liquid-impermeable back sheet 12. In manufacturing, after the back surface of the interior body 10 is fixed to the inner surface (upper surface) of the exterior sheet 20 by a joining means such as a hot melt adhesive G, the interior body 10 and the exterior sheet 20 are the front body F and the back body. Folded at the center of the vertical direction (front-rear direction) which is the boundary of B, both sides thereof are joined to each other by heat welding or hot melt adhesive, etc., and side seal portions 21 and 22 are formed. And it becomes a pants type disposable diaper in which a pair of left and right leg openings are formed.

(External sheet structure example)
As shown in FIGS. 4 to 6, the exterior sheet 20 is a nonwoven fabric sheet having a two-layer structure composed of an upper layer nonwoven fabric 20 </ b> A and a lower layer nonwoven fabric 20 </ b> B (that is, the lower layer nonwoven fabric is the outermost nonwoven fabric in this embodiment). Various elastic members are sandwiched and fixed in an expanded state between the nonwoven fabric of the upper layer nonwoven fabric 20A and the lower layer nonwoven fabric 20B and between the nonwoven fabrics of the folded portion 20C formed by folding the lower layer nonwoven fabric 20B to the inner surface side at the waist opening edge, thereby imparting elasticity. ing. The planar shape has a pseudo hourglass shape as a whole by concave leg-around lines 29 formed to form leg openings on both sides of the middle. As the elastic member, a synthetic rubber or natural rubber processed into an arbitrary form such as a thread, string, net, or sheet can be used.

  In particular, in the exterior sheet 20 of the illustrated form, as shown in FIGS. 1 to 3, the waist elastic members 24, 24... Disposed in the vicinity of the waist opening 23 in each of the front body F and the back body B. A plurality of waist elastic members 25, 25... Arranged in the crotch side with respect to the waist elastic member and arranged in the width direction at intervals in the vertical direction, and waist elastic members 25, 25. Aside from the side seal portions 21 and 22 that join the front body F and the back body B, the portions that overlap with both side portions of the interior body 10 are curved toward the opposite body side toward the center in the width direction. A plurality of curved elastic members 26..., 28... That extend up to (or do not necessarily overlap each other, such as in the vicinity of both side portions) and that are spaced apart from each other. Yes. In the exterior sheet 20, the curved elastic members 26, 28, etc. ensure the fit around the legs, so that the leg circumferences that are substantially continuous from the front body F to the back body B along the leg circumference line 29. Although the elastic member is not provided, it is also possible to provide it together with or instead of the curved elastic members 26.

  The waist elastic members 24, 24... Are a plurality of thread rubber-like elastic members arranged in the vertical direction near the waist opening edge in the vertical range having the side seal portions 21, 22. It is for attaching the waist opening edge of a diaper to a body by giving an elastic force so that the circumference | surroundings of the waist part of a body may be tightened. For the waist elastic member 24, rubber thread is used in the illustrated example. However, for example, a tape-like elastic member may be used. Further, the waist elastic members 24, 24... Shown in the figure are sandwiched between the nonwoven fabrics of the folded portions 20C of the lower layer nonwoven fabric 20B at the waist, but may be sandwiched between the upper nonwoven fabric 20A and the lower layer nonwoven fabric 20B. good.

  The waist elastic members 25, 25... Are spaced vertically in the vertical range corresponding to the side seal portions 21, 22 and the range from the crotch side to the upper side to the lower side. It is a slender elastic member such as rubber thread arranged along the width direction, and gives a stretchable force in the width direction to the waist part of the front body F and the back body B, respectively, to bring the diaper into close contact with the body Is. The boundary between the waist elastic members 24, 24... And the waist elastic members 25, 25. For example, among the elastic members arranged in the width direction with an interval in the vertical direction on the front body F and the back body B, even if the number cannot be specified, several on the upper side function as the waist elastic members. The remaining elastic members only need to function as waist elastic members.

  In the back body B, the dorsal curved elastic members 26, 26,... Arranged separately from the waist elastic members 25, 25,... Have an acute angle side crossing angle .theta. A predetermined curve in which the vertical crossing angle θ increases within a range of 0 ° to 90 ° from the minimum point toward the both sides in the width direction, and In a state where the diaper is unfolded, it is arranged along a predetermined curve having a crossing portion 70 having a vertical crossing angle θ of 60 ° or less in a region overlapping with both side portions of the interior body 10. There may be one dorsal curved elastic member 26, but it is preferable that there are a plurality of dorsal curved elastic members 26. In the illustrated example, there are five elastic rubber-like elastic members, and these dorsal curved elastic members 26, 26. They are arranged at intervals without crossing. The dorsal curved elastic member groups 26, 26,... Are arranged so as to form a predetermined expansion / contraction zone, instead of arranging a few elastic expansion / contraction members at a close interval and substantially as one bundle. Plural or more are arranged at predetermined intervals.

  In the front body F of the exterior sheet 20, the ventral curved elastic members 28, 28... Arranged separately from the waist elastic member groups 25, 25. Is a predetermined curve in which the longitudinal crossing angle θ increases within the range of 0 degrees to 90 degrees from the minimum point toward both sides in the width direction, and the diaper is unfolded In the region overlapping the both side portions of the interior body 10, the longitudinal crossing angle θ is arranged along a predetermined curve having an intersecting portion 70 having a value of 60 ° or less. The ventral curved elastic members 28, 28... May be one, but preferably a plurality. The illustrated example is five thread-like elastic members, and these ventral curved elastic members 28, 28. They are arranged at intervals without crossing each other. The ventral curved elastic member groups 28, 28,... Are not substantially arranged as a bundle with a few intervals between the two or three elastic elastic members so as to form a predetermined elastic zone. Plural or more are arranged at predetermined intervals.

  The curved elastic members 26, 28,... May not be entirely curved as in the illustrated example, and may partially have a linear portion. When the curved elastic members 26, 28,... Are provided on both the front body F and the back body B, a part or all of the group of the curved elastic members 28 arranged on the front body F side and the back body B side. A form (not shown) in which a part or all of the group of curved elastic members 26 arranged on the crotch part intersects at the crotch part or in the vicinity of the front side or the rear side thereof can be adopted, but as shown in the illustrated example, the front body F side The group of curved elastic members 28 arranged on the back side and the group of curved elastic members 26 arranged on the back body B side do not cross each other, and in the longitudinal direction at a position slightly deviated from the front / rear middle part, particularly the front body F The minimum vertical separation distance in the vertical separation range 90 is preferably about 10 to 20 mm, and a wide fixed region described later is preferably provided in this portion.

  On the other hand, in the illustrated example, the waist elastic members 25, 25... And the curved elastic members 26, 28... Arranged in the front body F and the back body B are not provided in a portion crossing the interior body 10. This portion is a non-stretchable region. Thus, the form which does not have or is not provided with the elastic member includes the form in which the elastic member is present, but also the form in which the elastic member is present but is finely cut to the extent that the contraction force does not act. FIG. 8 shows the latter example. The waist elastic members 25, 25... And the curved elastic members 26... 28 are crossed across the interior body 10 from the side joint edge 22 on one side (opposite side). After continuously providing up to the side joint edge 22 on the side, a part or all of the portion crossing the interior body 10 is cut by a predetermined cutting pattern CP to make it discontinuous. By making the elastic members 25, 26 and 28 discontinuous at the portion overlapping the interior body 10, shrinkage in the width direction of the interior body 10 (particularly the absorber 13) can be prevented. Of course, the waist elastic members 25, 25... And the curved elastic members 26... 28 can be continuously arranged across the interior body 10.

  The above-described exterior sheet 20 can be manufactured by, for example, techniques described in Japanese Patent Application Laid-Open No. 4-28363 and Japanese Patent Application Laid-Open No. 11-332913. Moreover, in order to cut | disconnect the curved elastic members 26 ... 28 on the interior body 10 and to make it discontinuous, it describes in Unexamined-Japanese-Patent No. 2002-35029, Unexamined-Japanese-Patent No. 2002-178428, and Unexamined-Japanese-Patent No. 2002-273808. The cutting method to be used is preferably employed.

(Bent fit part)
Characteristically, as shown in FIG. 11, a bent fitting portion 40 that is bent so as to enter the wearer's crack is provided at the crack facing portion in the back body B. The part shown with the dashed-two dotted line in FIG. 11 has shown the bending fitting part 40 of the bent state. The bent fitting portion 40 can also be formed by providing a groove 41 or a slit along the longitudinal direction in the crack facing portion of the absorbent body 13, in which case the bent fitting portion 40 is formed with a fold as an appropriate position. The shape is also easily maintained, but in addition to or instead of this, the contraction force in the width direction acts on the crack facing portion of the crack facing portion and the both sides of the back body B so as to act in the width direction. It is preferable to provide the cracked part elastic member 42 and to form the bent fitting part 40 by the contracting action of the cracked part elastic member 42 because the bent shape can be elastically maintained.

  The cracked part elastic member 42 is provided with a dedicated elastic member at a predetermined part of the back body B, and together with or instead of the dedicated elastic member, the waist elastic member 25 and the curved elastic member 26. It can also comprise using the part which crosses a crack opposing part along the width direction. When a dedicated elastic member is provided, a sheet-like elastic member can be used in addition to an elongated elastic member such as rubber thread.

  In the illustrated example, the curved elastic member 26... And the waist elastic member 25 provided in the back body B are used as the cracked elastic member 42. More specifically, as shown in FIG. 8, a plurality of waist elastic members 25 are continuously provided in the width direction at a portion passing through the crack facing portion of the exterior sheet 20 of the back body B, and the curved elastic members 26. Are continuously provided so that a part (or all) of the portion curved to the crotch side may cross the crack facing portion in the width direction, and then the elongated elastic members 25,. The part located on both sides of the crack facing part in ... is cut finely, the part located in the crack facing part is left uncut and not cut, and the part left uncut is It functions as the crack elastic member 42, and a contraction force in the width direction acts on the crack facing portion, the crack facing portion of the back body B bends and the inner surface rises in a ridge shape.

  The contraction force acting portion of the cracked elastic member 42 has a rectangular shape extending in the front-rear direction, a shape that increases in width toward the front side (for example, an isosceles triangle shape whose base is located on the front side, and its isosceles are curved. It may be a trumpet shape), but the width increases from the front end to the middle in the front-rear direction of the crack-facing portion, and the width increases toward the rear side, and further on the rear side, the width decreases toward the rear side. In particular, it is preferable because the bent fitting portion 40 that fits suitably against the crack is formed.

  Although the size of the contraction force acting part (region having the cracked part elastic member 42) of the cracked part elastic member 42 can be appropriately determined, the width is narrower than that of the absorber 13, for example, within a range of 40 to 90 mm. It is desirable that the length in the front-rear direction is about 1/5 to 1/2 of the length in the front-rear direction of the absorber 13. Moreover, it is preferable that the front end is located in the front-back direction center or its vicinity. The non-cut portion NC in the above-described cutting pattern has the same shape as the contraction force acting portion and has the same or slightly larger dimensions. Further, the length and width of the groove 41 or slit provided in the absorber 13 described above may be shorter, longer or the same as the contraction force acting part, but the width is less than the contraction force acting part. It is preferable to do this.

(Balance of tensile stress during longitudinal elastic deformation)
Also, characteristically, curved elastic members 26, 28,... Are provided as pulling elastic members that exert a contraction force of a longitudinal component so as to lift the crotch portion toward the waist in the front body F and the back body B, The longitudinal contraction force balance in which the tensile stress at the time of elastic deformation in the front body F is larger than the tensile stress at the time of elastic deformation in the longitudinal direction of the back body B is set. The tensile stress at the time of elastic deformation is the tensile test of the waist opening edge part of the body part to be measured and the crotch side end part of the opposite body part not to be measured, after peeling off both side seal parts 21 and 22 of the diaper and making them unfolded. It can be measured by holding each with a machine chuck and performing a tensile test. The difference in tensile stress at the time of elastic deformation can be determined as appropriate, but the tensile stress at the time of elastic deformation at 80% elongation in the front body F is about 1.1 to 1.2 times that in the back body B. Preferably there is.

  When the front elastic body 26, 28,... Are provided on the front body F and the back body B as described above, and the tensile stress during the longitudinal elastic deformation in the front body F is larger than that of the back body B, FIG. As shown in FIG. 11, in the mounted state, the crotch portion of the diaper is moved forward by the contraction force of the pulling elastic member 28 of the front body F against the contraction force of the pulling elastic member 26 of the back body B. While lifting, the crotch fits and the front end of the bent fitting portion 40 is pulled forward, and as a result, the bent fitting portion 40 fits the fissure while maintaining its bent state. Therefore, while fitting well from a rupture to a crotch, the fit follows the movement of a body and is maintained elastically, and a crotch part becomes difficult to mokomoko at the time of mounting | wearing. On the other hand, in a conventional general pants-type disposable diaper, as shown in FIG. 12, as a result of the ruptured opposing part bulging and being largely separated from the skin, the crotch part is mokomoko, remarkably different from ordinary underwear Different discomfort occurs.

  In the illustrated example, the pulling elastic member is composed of only the curved elastic members 26. The curved elastic members 26..., 28... Have a function of improving the fit to the buttocks in the front body F and improving the fit to the swelling of the buttocks in the back body B. Of course, instead of or together with the curved elastic members 26, 28, etc., an elastic member such as an elongated shape or a sheet shape may be fixed in a stretched state along the longitudinal direction at the intermediate portion in the width direction to form a lifting elastic member ( (Not shown). When the curved elastic members 26, 28,... Are used in combination with other types of lifting elastic members, the curved elastic members 26, 28,... Are used as either the front body F or the back body B, unlike the illustrated example. Only the other elastic member may be provided on the other side.

  In particular, when the curved elastic members 26, 28, etc. as shown in the illustrated example are provided, the longitudinal interval of the curved elastic members 26 in the rear body B is the front body F at the outer side in the width direction from the side edge of the interior body 10. If the arrangement is wider than the vertical spacing of the curved elastic members 28 in the case, the fitting elastic property of entering the buttocks by the curved elastic members 28 of the front body F is exhibited, and the buttocks by the curved elastic members 26 of the back body B In addition to exhibiting a fitting property that envelops the bulge, when the bent fitting portion 40 fits into a crack while maintaining its bent state, it is difficult to cause a situation of biting into the crack. Therefore, it is preferable.

  The aforementioned front-rear contraction force balance is a factor of the tensile stress at the time of elastic deformation in the body F and B, which is at least one of the thickness, elongation rate, and number of the pulling elastic members 26. Realized by making them different. When adjusting the thickness or the like of the pulling elastic members 26, 28, etc., the number of the pulling elastic members 26, 28, etc. is preferably determined according to the size and arrangement of the diapers. The front body F is preferably thicker or higher than the back body B so that at least one of the thickness and the elongation rate is obtained so that the aforementioned front-rear contraction force balance can be obtained.

Specifically, in the illustrated example, it is preferable to define the specifications of each part within the following range. Although the unit of thickness of the elastic member is unified to dtex, it is not limited to synthetic rubber, and natural rubber can be used. The unit dtex when natural rubber is used is the synthesis of the dtex. This means the thickness of natural rubber having an SS curve equivalent to that of rubber (eg, 0.5 mm to 3.0 mm when natural rubber is used for the waist elastic member 24).
・ Exterior sheet 20
Material: Non-woven fabric Basis weight: 30-75 g / m ² , especially 36-60 g / m ²
-Waist elastic member 24 of front body F and back body B
Thickness: 470 to 1,240 dtex, especially 940 to 1,240 dtex
Number: 5-10, especially 8-10 (each body)
Spacing: 0-5mm, especially 3-5mm
Elongation rate when fixed: 200 to 350%, especially 250 to 300%
-Elastic member 25 around the waist of the front body F
Thickness: 470-1,240 dtex, especially 470-620 dtex
Number: 6-26, especially 8-16 Interval: 10-40 mm, especially 15-35 mm
Elongation rate when fixed: 200 to 350%, especially 250 to 300%
-Of the waist elastic part 25 of the back body B, those not constituting the crack elastic member 42 Thickness: 470-1,240 dtex, especially 470-620 dtex
Number: 6-24, especially 9-14 Interval: 10-40 mm, especially 15-35 mm
Elongation rate when fixed: 200 to 350%, especially 250 to 300%
Of the waist elastic member 25 of the back body B, what constitutes the cracked elastic member 42 Thickness: 470 to 1,240 dtex, especially 940 to 1,240 dtex
Number: 5 to 20, especially 9 to 10 Spacing: 5 to 20 mm, especially 10 to 16 mm
Elongation rate when fixed: 200 to 350%, especially 250 to 330%
-Curved elastic member 28 of front body F
Thickness: 620-1,240 dtex, especially 620-940 dtex
Number: 3-10, especially 5-10 Interval: 10-35 mm, especially 16-32 mm
Elongation rate at the time of fixation: 230 to 380%, particularly 300 to 380%, and higher elongation rate than the curved elastic member 26 of the back body B. The curved elastic member 26 of the back body B (including the constituent parts of the cracked elastic member 42) )
Thickness: 620-1,240 dtex, especially 620-940 dtex
Number: 3-10, especially 5-10 Interval: 10-35 mm, especially 16-32 mm
Elongation rate when fixed: 200 to 350%, especially 250 to 300%

(Configuration for exterior sheet flexibility)
The longitudinal range having the waist elastic members 25... And the longitudinal range 31 having the curved elastic members 26..., 28. A plurality of the elastic members 25 (for example, about 5 to 10) are included, and the mutual interval d1 of at least some of the waist elastic members 25 is greater than the mutual interval d2 of the other waist elastic members 25. It is preferable that it is wide. Further, even outside the overlapping range 30, the waist elastic member 25... Is in an intermediate range 32 between the longitudinal range 31 having the curved elastic members 26, 28, and the longitudinal range having the waist elastic member 24. It is preferable to provide a plurality (for example, about 10 to 16).

  In this way, while allowing the overlap range 30 between the longitudinal range having the waist elastic members 25 ... and the longitudinal range having the curved elastic members 26, 28 ... to some extent, the waist elastic members 25 ... are within that range. By providing a portion with a large mutual interval, the denseness of the elastic members can be suppressed without impairing the fit. As a result, the pleats are not concentrated on the exterior sheet 20 in the overlapping range 30, an unnecessary increase in thickness, the elastic member itself and hardening due to its adhesion are suppressed, and a flexible and comfortable wearing feeling can be obtained. Become.

  In the normal case, the mutual distance d1 between the waist elastic members 25 is preferably about 15 to 50 mm, and the mutual distance d2 between the other waist elastic members 25 is preferably about 10 to 20 mm. The longitudinal length of the overlapping range 30 is preferably about 15 to 30% of the total length of the diaper in the unfolded state, and the waist portion elastic members 25 occupying the overlapping range 30 have a wide interval portion 35. The ratio is preferably about 60 to 100% in the ratio of the length in the vertical direction (that is, the sum of the distances d1 / the vertical length of the overlapping range 30). If the overlapping range 30 is too narrow, the significance of widening the interval between the waist elastic members 25 becomes thin. If it is too wide, the wide portion 35 of the waist elastic members 25 increases, resulting in a decrease in fit. In addition, if the proportion of the portion 35 having a wide mutual spacing between the waist elastic members 25 occupying the overlapping range 30 is too small, improvement in flexibility can be expected, but remarkable improvement becomes difficult.

  Specifically, in the case of the illustrated example, the ratio of the wide portion 35 having the mutual interval d1 of the waist elastic members 25 to the overlapping range 30 is about 40% in the front body F and 100% in the back body B. . As described above, the configuration relating to the improvement in flexibility can be made different between the front body F and the back body B, and can be applied only to either the front body F or the back body B in the exterior sheet 20. (same as below).

  On the other hand, the waist elastic member 24, the waist elastic member 25, and the curved elastic members 26, 28 are sandwiched between a pair of sheet layers 20A, 20B constituting the exterior sheet 20, and the sheet layers 20A, 20B, The adhesive is fixed to 20B with an adhesive, and the amount of adhesive applied greatly affects the flexibility of the exterior sheet 20. Therefore, as shown in FIG. 7, the adhesive portions B1 and B2 by the adhesive include the arrangement portion of the waist elastic member 24 and the vicinity thereof, the arrangement portion of the waist elastic member 25, and the vicinity thereof, the curved elastic member 26,. , 28... And a region within a predetermined distance a within each length and width (normally within ± 25 mm, more preferably within ± 10 mm, particularly preferably within ± 5 mm), and both sheets other than these adhesives. It is preferable not to apply an adhesive between the layers. In this way, by reducing the adhesive application portion as much as possible, hardening by the adhesive can be suppressed at each stage. In addition, when this is combined with the increase in the local spacing between the waist elastic members 25.

  FIG. 7 shows application sites B1, B2 of the hot melt adhesive in the manufacturing process, and the curved elastic members 26, 28, ... are in a state before cutting of a portion crossing the interior body 10 as indicated by a two-dot chain line. Is shown. Adhesives B1 and B2 for fixing the waist elastic member 24 and the waist elastic member 25 to the two sheet layers 20A and 20B are substantially applied only to the arrangement portions of the elastic members 24 and 25 and the vicinity thereof. Yes. Such application of the adhesive can be realized by sandwiching the elastic members 24 and 25 having the adhesive applied to the outer peripheral surface between the two sheet layers 20A and 20B, and the outer peripheral surfaces of such elastic members 24 and 25. The adhesive can be applied to a Nordson Surerup nozzle.

  On the other hand, the adhesive for fixing the curved elastic members 26 ..., 28 ... to the two sheet layers 20A, 20B has a rectangular adhesive application portion B2 in a step shape along the bending direction of the curved elastic members 26 ..., 28 ... , The adhesive is applied only to the portion where the curved elastic members 26, 28,..., 28. ing. In the application process, in the normal form in which the lateral direction (diaper width direction) of the sheet layers 20A and 20B is along the line MD direction (flow direction) in the application process, the adhesive layer crosses the line CD direction (MD direction). In the direction), a plurality of slot coating nozzles are arranged in parallel, and the adhesive can be applied independently and intermittently from each nozzle.

(Structural example of interior body)
As shown in FIGS. 4 to 6, the interior body 10 has an absorbent body 13 interposed between a liquid-permeable top sheet 11 made of a nonwoven fabric or the like and a liquid-impermeable back side sheet 12 made of polyethylene or the like. The excretory fluid that has permeated through the top sheet 11 is absorbed and retained.

  As the liquid-permeable surface sheet 11 covering the surface side (skin contact surface side) of the absorbent body 13, a porous or non-porous nonwoven fabric or a porous plastic sheet is preferably used. The material fibers that make up the nonwoven fabric can be synthetic fibers such as olefins such as polyethylene or polypropylene, polyesters, and polyamides, recycled fibers such as rayon and cupra, and natural fibers such as cotton. A nonwoven fabric obtained by an appropriate processing method such as a spun bond method, a thermal bond method, a melt blown method, or a needle punch method can be used. Among these processing methods, the spunlace method is excellent in terms of flexibility and drapeability, and the thermal bond method is excellent in terms of being bulky and soft. When a large number of through holes are formed in the liquid permeable surface sheet 11, urine and the like are quickly absorbed, and the dry touch property is excellent. The liquid permeable top sheet 11 is wound around the side edge of the absorber 13 and extends to the back side of the absorber 13.

  As the liquid-impermeable back sheet 12 that covers the back surface side (non-skin contact surface side) of the absorbent body 13, a liquid-impermeable plastic sheet such as polyethylene or polypropylene is used. Those having wettability are preferably used. This water-impervious / breathable sheet is a microporous sheet obtained by, for example, melt-kneading an inorganic filler in an olefin resin such as polyethylene or polypropylene to form a sheet, and then stretching in a uniaxial or biaxial direction. is there.

  Absorbent body 13 is a known one, for example, a pulp fiber stack, a filament aggregate such as cellulose acetate, or a non-woven fabric, mixed with a superabsorbent polymer as necessary, fixed, etc. In the example shown in the figure, a shape formed with a substantially rectangular planar shape is used, and the width dimension is a dimension width that does not give the wearer a feeling of goreness by hitting the crotch part. The absorbent body 13 can be packaged with a wrapping sheet 14 having liquid permeability and liquid retention, such as crepe paper, if necessary, for holding the shape and polymer. The shape of the absorber 13 may be a rectangular shape as shown in the figure, or may be an hourglass shape (constricted shape) in which the width of the crotch portion is narrower than the back side and the abdominal side.

  It is preferable that solid gather BSs that fit around the legs are formed on both sides of the interior body 10. This three-dimensional gathered BS is formed by the gathered nonwoven fabric 15. As the gathered nonwoven fabric, as shown in FIGS. 5 and 6, a nonwoven fabric made into a double sheet by folding is preferably used. The side edge portion of the wound absorbent body 13 is further wound from the upper side thereof and extends to the back surface side of the absorbent body 13 to be bonded. More specifically, the gathered nonwoven fabric 15 has a three-dimensional gather BS forming portion left in the middle portion in the longitudinal direction of the diaper 1, and a range from the middle portion in the width direction to the back side of the absorbent body 13 is bonded by a hot melt adhesive or the like. Further, at the longitudinal front and rear end portions, the section from the width direction intermediate portion to the one side end edge is bonded in a range extending to the back surface side of the absorber 13, and a portion forming the three-dimensional gather BS is attached to the absorber 13 It is bonded with a hot melt adhesive or the like while being folded at the upper surface.

  Inside the gathered nonwoven fabric 15 formed of a double sheet nonwoven fabric, a plurality of thread-like elastic elastic members 16, 16... The thread-like elastic elastic members 16, 16... Are for forming a three-dimensional gather BS by raising the nonwoven fabric portion protruding from the absorber side edge by elastic elastic force as shown by a two-dot chain line in FIG. 5 in the product state. It is.

  The liquid-impermeable back side sheet 12 enters the inside of the double sheet-like gathered nonwoven fabric 15 and constitutes a leak-proof wall on the lower end side of the three-dimensional gathered BS as shown in FIG. . As the liquid-impermeable back side sheet 12, it is desirable to use an opaque sheet so that brown such as defecation and urine does not appear. As the opacification, a plastic film and a pigment and filler such as calcium carbonate, titanium oxide, zinc oxide, white carbon, clay, talc and barium sulfate are preferably used.

  As the thread-like elastic elastic member 16, materials such as styrene rubber, olefin rubber, urethane rubber, ester rubber, polyurethane, polyethylene, polystyrene, styrene butadiene, silicon, polyester, and the like that are usually used can be used. In order to make it difficult to see from the outside, it is preferable that the thickness is 925 dtex or less, the tension is 150 to 350%, and the interval is 7.0 mm or less. Instead of the thread-like elastic elastic member, a tape-like elastic elastic member having a certain width may be used.

  In the same manner as the liquid-permeable surface sheet 11, the material fibers constituting the gathered nonwoven fabric 15 are olefin-based, polyester-based, amide-based synthetic fibers such as polyethylene or polypropylene, regenerated fibers such as rayon and cupra, and cotton. Non-woven fabric obtained by an appropriate processing method such as a spunbond method, a thermal bond method, a melt blown method, a needle punch method, etc. can be used. It is preferable to use a nonwoven fabric that suppresses the basis weight and has excellent air permeability. Furthermore, for the gathered nonwoven fabric 15, in order to prevent the transmission of urine and the like, to prevent fogging, and to enhance the touch to the skin (dry feeling), silicon-based, paraffin metal-based, alkylchromic croid-based water repellent, etc. It is desirable to use a water-repellent non-woven fabric coated with.

(Fixing the interior and exterior sheets)
The interior body 10 and the exterior sheet 20 are fixed to each other with a characteristic structure. As shown in FIG. 3, in a state where the diaper is unfolded, an intersection 70 where the acute angle crossing angle θ between the curved elastic members 26... The outer sheet 20 and the inner body 10 are not fixed in the vertical range (in the illustrated example, the entire vertical range) of 80% or more of the portion 80, 81, 82 other than this. The exterior sheet 20 and the interior body 10 are fixed by a joining means such as a hot melt adhesive. As a result, the contraction force of the curved elastic members 26... 28 is hardly or not applied to the side portion of the interior body 10, and as a result, the curved elastic members 26. Also, the thickness and hardness of the diaper are about the same as the surroundings, and recumbency is hardly generated on the inner surface of the interior body 10. In addition, as long as 80% or more of the vertical range of the intersecting portion 70 is a fixed portion, not only a form in which the entire portion is continuously fixed as in the illustrated example, but also a portion of the intersecting portion is not fixed. It is also possible to fix it intermittently within the intersection.

  On the other hand, as described above, when the non-fixed region 71 is provided in the range including the intersecting portion 70, the fixed region between the exterior sheet 20 and the interior body 10 is inevitably reduced in the same vertical range as the intersecting portion 70. . Therefore, in a state where the diaper is unfolded and the position in the vertical direction is the same as that of the intersecting portion 70, a non-stretchable region not having an elastic member is provided on the center side in the width direction of the intersecting portion 70 and the portion is attached to the exterior sheet 20 In the range where the longitudinal position is on the waist side of the intersecting portion 70 from the width direction center side edge of the intersecting portion 70 to the width direction center side of the intersecting portion 70, the fixing region 80 with the interior body 10 is used. It is desirable to provide a non-stretchable region that does not have an elastic member and to use that portion as a fixing region 81 between the exterior sheet 20 and the interior body 10. Specifically, as in the illustrated example, the fixed width between the exterior sheet 20 and the interior body 10 is set to be equal to or less than the interval between the intersecting portions 70 on both sides in the width direction in the same vertical range as the intersecting portion 70. On the waist side, it is proposed to make it wider (may be enlarged stepwise as in the illustrated example or may be enlarged continuously). Thereby, fixation of the interior body 10 becomes stronger.

  Moreover, while arrange | positioning the curved elastic members 26 ..., 28 ... in the front body F and the back body B, respectively, while ensuring the vertical direction separation | spacing range 90 without making the front and back curved elastic members 26 ..., 28 ... cross | intersect each other, Also in this longitudinally spaced region 90, a non-stretchable region not having an elastic member is provided from the width direction outer side to the width direction center side of the intersecting portion 70 with respect to the width direction center side edge of the intersecting portion 70, and this portion is provided as an exterior sheet. It is also proposed that the fixed width 82 in the vertical direction separation range 90 is made wider than the fixed width in the same vertical direction range as the intersecting portion 70 as the fixed region 82 between the inner body 20 and the interior body 10. Thereby, fixation of the interior body 10 can be made still stronger.

(Front / rear presser sheet)
As shown in FIGS. 1 and 4, in order to cover the front and rear end portions of the interior body 10 attached on the inner surface of the exterior sheet 20 and to prevent leakage from the front and rear edges of the interior body 10, 50, 60 are provided. The illustrated embodiment will be described in more detail. The front presser sheet 50 extends over the entire width direction from the inner surface of the folded portion 20C of the waist side end portion to the position overlapping the front end portion of the interior body 10 in the inner surface of the front body F. The rear presser sheet 60 extends across the entire width direction from the inner surface of the folded portion 20C at the end on the waist side to the position overlapping the rear end of the interior body 10 in the inner surface of the back body B. If a slight non-adhesive portion is provided in the crotch side edges of the front and rear presser sheets 50, 60 over the entire width direction (or only the central portion), not only the adhesive does not stick out, but also this portion is removed from the surface sheet. It can be lifted slightly to function as a leak-proof wall.

  When the front and rear presser sheets 50 and 60 are attached as shown in the figure, there is an advantage that the degree of freedom of material selection is increased, but there are also disadvantages such as an increase in materials and manufacturing processes. Therefore, the folded portion 20C formed by folding the exterior sheet 20 on the inner surface of the diaper 1 can be extended to a portion overlapping the absorbent pad 200 to form a portion equivalent to the presser sheets 50 and 60 described above.

(About the non-woven fabric constituting the exterior sheet)
Of the non-woven fabrics constituting the exterior sheet 20, at least the outermost non-woven fabric 20B preferably has a twist degree of 3.8 gf · cm / cm or less. Here, the “degree of twist” can be measured using, for example, KES-YN1 (manufactured by Kato Tech Co., Ltd.), and the smaller the value, the more flexible the twist. Moreover, when an exterior sheet | seat consists of one nonwoven fabric, it itself means the nonwoven fabric located in the outermost side. It is desirable to employ the same nonwoven fabric as the outermost nonwoven fabric 20B for all the nonwoven fabrics constituting the exterior sheet 20, that is, the other nonwoven fabrics 20A, 50, 60 that are not located on the outermost side (the same applies hereinafter). In this way, when a nonwoven fabric with a sufficiently low twist is used, the flexibility of the diaper as a whole is remarkably increased, and as a result, the feeling of wearing and the skin troubles such as itching and rash due to rubbing with the skin are reduced. In addition, there are advantages such as easy removal and attachment. If the degree of twist is not sufficiently low, the effect of improving flexibility is not exhibited. Such a twist degree can be achieved, for example, by selecting the type of raw fiber, reducing the fineness, shortening the fiber length, reducing the basis weight or thickness, and the like.

  Further, the ratio MIU / MMD between the average surface friction coefficient and the average deviation in the outermost nonwoven fabric 20B is preferably 20 or more, and more preferably 25 or more. By sufficiently increasing the MIU / MMD ratio, the feel of the exterior sheet surface is improved, so that the suppleness is compensated, and skin troubles such as itching and rash due to rubbing with the skin are further reduced. become. Such an MIU / MMD ratio can be achieved, for example, by reducing the fineness or performing surface processing.

In addition, the outermost nonwoven fabric 20B has a thickness when the basis weight is 10 to 30 g / m ² and the pressure is 0.5 g / cm ² so as not to impair the basic functions (hiding function, strength, etc.) as the exterior sheet 20. It is preferable that T0 is 0.1 to 1.0 mm. A more preferable basis weight is 13 to 22 g / m ² , and a thickness T0 is 0.1 to 0.5 mm.

  Furthermore, in order to compensate for flexibility, the bending resistance of the outermost nonwoven fabric 20B according to JIS-L-1096 (45 degree cantilever method) is preferably 45 mm or less, and more preferably 35 mm or less. Thereby, the reduction of the feeling of tingling and the ease of putting on and taking off become even more preferable. Such bending resistance can be achieved, for example, by selecting the type of raw fiber, changing the ratio, lowering the embossing pressure, reducing the basis weight or thickness, and the like.

  Since the strength tends to decrease when the flexibility is improved, the outermost nonwoven fabric 20B has a tensile strength defined in JIS-P-8113 of 40 to 120 kgf / m in the width direction, particularly 60 to 100 kgf / m, in the front-rear direction. It is preferably 10 to 80 kgf / m, particularly 25 to 60 kgf / m, and the tear strength specified in JIS-P-8116 is preferably 4 to 30 kgf / m, particularly 8 to 25 kgf / m in the front-rear direction. Such tensile strength and tear strength can be achieved, for example, by increasing the degree of entanglement between fibers.

  The compression characteristics of the outermost nonwoven fabric 20B are also closely related to flexibility. Therefore, the compression characteristics of the outermost nonwoven fabric 20B are such that the compression hardness LC is 0.3 to 1.0, particularly 0.5 to 0.9, and the compression work WC is 0.01 to 0.10. The compression resilience RC is preferably 20 to 90%, particularly preferably 25 to 70%. Such compression hardness LC, compression work WC, and compression resilience RC can be achieved, for example, by selecting the type of raw fiber, changing the ratio, reducing the basis weight, and the thickness.

  The outermost nonwoven fabric 20B is not particularly limited with respect to the material, structure, manufacturing method, fineness, fiber length (short fiber, filament), and the like of the raw fiber. For example, the raw fiber can be appropriately selected from olefins such as polyethylene and polypropylene, synthetic fibers such as polyester and polyamide, recycled fibers such as rayon and cupra, natural fibers such as cotton, and the fiber structure is parallel. It can be suitably selected from two-layer type composite fibers such as molds and core-sheath types, multilayer type composite fibers, non-composite fibers, mixed fibers, and split fibers. Furthermore, as a manufacturing method, it can select and use suitably from well-known methods, such as the spunlace method, the spun bond method, the thermal bond method, the melt blown method, the needle punch method, the air through method, the point bond method. Known specifications can be adopted for the fineness and fiber length of the fiber, but the fineness is preferably 0.7 to 3 dtex, particularly 1 to 2.5 dtex.

(Test example)
Various nonwoven fabric samples were prepared and subjected to various tests and measurements. The constituent fibers of each sample nonwoven fabric are all continuous fibers (long fibers) as can be seen from the production method, and the fiber diameters are all measured by microscopic observation. As a result, they are almost the same thickness (about 0.15 to 0.25 μm). )Met. In accordance with the Gakushin type friction test specified in JISK6404-16, the fluff test is performed on a non-woven fabric sample using a friction cloth covered with a dry white cotton cloth, and the state of the fluff is observed with a microscope. 1: The height of the fluffy fiber is 1 mm or less, 2: The height of the fluffy fiber is 2 mm or less, 3: The height of the fluffy fiber is 3 mm or less, 4: The amount of fluff is not large, but The height is 3 mm or more, 5: The amount of fluff is large and the entire surface is fluffed, and the height of the fluffy fiber is 3 mm or more. The MIU / MMD ratio was calculated by (MIU (width direction) + MIU (front-rear direction)) / (MMD (width direction) + MMD (front-rear direction)). Other conditions (adhesive usage, etc.) not specifically mentioned were common to all samples.

  Furthermore, each sample nonwoven fabric has substantially the same structure as the structure shown in FIGS. 1 to 11 (there is no bent fitting part or cracked part elastic member, and the interval between the curved elastic members is substantially the same between the front body and the back body). Construction of exterior sheet 20 in type disposable diaper A pants-type disposable diaper similar to that shown in the figure is used as the nonwoven fabric 20A, 20B, 51, 61, and sensory evaluation of the flexibility as a diaper (○: suppleness) Rich, Δ: normal, ×: messy).

  The above results are summarized in Table 1. Also, some graphs are shown in FIGS. As is clear from these results, Samples 1 to 9 were rich in flexibility as diapers. Among them, the sensory evaluation of those having MIU / MMD of 20 or higher was high, and among them, the sensory evaluation of those having a bending resistance of 35 mm or less was high.

  The present invention can be used in a pants-type disposable diaper as in the above example.

  DESCRIPTION OF SYMBOLS 1 ... Pants type disposable diaper, 10 ... Interior body, 11 ... Liquid-permeable surface sheet, 12 ... Liquid-impermeable back side sheet, 13 ... Absorber, 14 ... Packaging sheet, 15 ... Gathered nonwoven fabric, 16 ... Yarn-like elastic stretch 20 ... exterior sheet, 21, 22 ... side joint edge, 24 ... waist elastic member, 25 ... waist elastic member, 26 ... dorsal curved elastic member, 28 ... ventral curved elastic member, 29 ... leg circumference Line, 20C ... exterior sheet folded portion, 70 ... intersection, 71 ... non-fixed region, 80, 81, 82 ... fixed region, [theta] ... longitudinal crossing angle, F ... front body, B ... back body.

Claims (6)

An exterior sheet that forms a front body and a back body, and an interior body including an absorbent body that is fixed to an inner surface of the exterior sheet, and both sides of the exterior sheet in the front body and both sides of the exterior sheet in the back body And pants type disposable diapers in which a waist opening and a pair of left and right leg openings are formed,
A bent fitting part that is bent so as to enter the wearer's crack is provided in the crack facing part in the back body,
The exterior sheet in the front body and the exterior in the back body as a pulling elastic member that exerts a contraction force of a longitudinal component so that the crotch portion is lifted to the waist side in each of the exterior sheet in the front body and the exterior sheet in the back body In each of the sheets, an elongated curved elastic member that extends while being curved toward the opposite body side from the both sides toward the center in the width direction is stretched at a predetermined elongation rate in the extending direction. Fixed,
In each of the exterior sheet in the front body and the exterior sheet in the back body, a plurality of elongated waist elastic members extending along the width direction are spaced apart in the longitudinal direction at the edge of the waist opening, respectively. Elongated waist elastic that is fixed in a state of being stretched at a predetermined stretch rate along the width direction and extends along the width direction in a region closer to the center in the front-rear direction than the waist elastic member A plurality of members are fixed in a state where they are stretched at a predetermined stretch rate along the width direction at intervals in the longitudinal direction,
The outer sheet is at least the waist elastic member, the portion having the waist elastic member, and the curved elastic member comprises an adhesive laminating a plurality of nonwoven fabrics, and the waist during the non-woven fabric of the outer sheet part elastic members, waist elastic members, and the curved elastic members are fixed,
Elastic deformation at 80% elongation in the longitudinal direction in the front body due to at least one of the thickness, elongation rate, and number of the curved elastic members being different between the curved elastic member in the front body and the curved elastic member in the back body The tensile stress at time is 1.1 times or more of the tensile stress at the time of elastic deformation at 80% elongation in the longitudinal direction in the back body.
A pants-type disposable diaper characterized by that.   A crack elastic member is provided on the back body so that a contraction force in the width direction acts on the crack facing portion of the crack facing portion and portions located on both sides thereof. The pants-type disposable diaper according to claim 1, wherein the bent fitting portion is formed by a contracting action of a member.   The crack part elastic member is an elongated elastic member extending across the crack facing part in the width direction, and the crack facing part of the crack facing part and portions located on both sides thereof The pants-type disposable diaper according to claim 2, wherein portions positioned on both side portions are finely cut so that a contractile force acts on the diaper.   The contraction force acting portion of the cracked portion elastic member has a width that increases from the front end of the crack facing portion to the middle in the front-rear direction toward the rear side, and further to the rear side, the width further toward the rear side. The pants-type disposable diaper according to claim 3, which has a reduced shape.   The groove | channel or slit which follows a crack is formed in the crack opposing part in the said absorber, The said bending | flexion fitting part is formed using this groove | channel or slit as a crease | fold, The any one of Claims 1-4. The pants-type disposable diaper described in 1. The curved elastic member in the front body and the curved elastic member in the back body are arranged in parallel with a predetermined interval, respectively.
The longitudinal direction interval of the curved elastic member in the back body is wider than the longitudinal direction interval of the curved elastic member in the front body at a portion on the outer side in the width direction from the side edge of the interior body. The pants-type disposable diaper described in 1.

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