TWI837419B - Shorts type disposable diaper - Google Patents

Abstract

The problem to be solved by the present invention is to provide a shorts-type disposable diaper that can improve the coverage of the buttocks. In order to solve this problem, the shorts-type disposable diaper of the present invention has a front outer body 12F and a rear outer body 12B, which have a waist circumference stretchable area A2 that is elastically stretchable in the width direction WD; an inner body 200 has side wings 70, and the side wings 70 have side stretchable areas SG that are elastically stretchable in the front-rear direction LD; each side wing 70 has a rear connection that is connected to the lower end 14 of the rear outer body 12B. The rear joining area 70B shrinks in the width direction WD together with the waist stretching area A2 of the rear outer body 12B and can stretch in the width direction WD; and, when the lower end portion 14 is stretched in the width direction to the elastic limit and then shrinks to 3/4 of its size, the stretching force of the front outer body 12F is greater than that of the rear outer body 12B.

Description

Briefs Disposable Diapers

The present invention relates to a shorts-type disposable diaper with a two-part outer structure, which improves the coverage of the buttocks.

A shorts-type disposable diaper with a two-part outer structure comprises: a front outer body, which constitutes at least the waistline of the front body; a rear outer body, which constitutes at least the waistline of the rear body; and an inner body including an absorbent body, which is installed on the outer body in a manner extending from the front outer body to the rear outer body; the two side portions of the front outer body and the two side portions of the rear outer body are joined together to form side sealing portions, thereby forming a waist opening and a pair of left and right leg openings (for example, refer to patent document 1).

In order to improve the fit to the body, such a shorts-type disposable diaper generally has a stretch structure provided on the front and rear outer bodies. For example, a shorts-type disposable diaper having a stretch region that can stretch in the width direction provided in a waist region determined by the front-rear direction range corresponding to the side seals or in a middle region between the front and rear waist regions has a relatively high fit to the body.

On the other hand, in the shorts-type disposable diaper of the outer two-part type, the fit of the leg opening cannot but be reduced. That is, in the shorts-type disposable diaper of the outer two-part type, when worn, the distance from the position corresponding to the crotch of the inner body to the intersection position of the inner body and the outer body is long, so the inner body is easy to swing left and right with the intersection position as a fulcrum, and the inner body is easy to move in the horizontal direction compared to the type of outer body that is continuous from the front to the back. In addition, in the shorts-type disposable diaper of the outer two-part type, the edge of the crotch side of the outer body is a straight line or a nearly straight line shape along the width direction, and intersects with the side edge of the inner body at a right angle or a nearly right angle. This means that the fit is likely to be insufficient near the intersection of the side edge of the inner body and the edge of the crotch side of the outer body in the edge of the leg opening.

In contrast, if side wings extending laterally further than the upright folds on both sides of the inner body extend from the front outer body to the rear outer body in the front-rear direction, and the side wings have side stretchable areas that elastically stretch in the front-rear direction, then the side stretchable areas elastically support the lateral movement of the inner body, and the side stretchable areas cover the side surfaces of the inner body, so that gaps are not easily generated on the side surfaces of the inner body, which is better.

Here, in order to fully demonstrate the fit of the side stretchable area, it is preferred to expand the inner and outer joints where the inner body and the outer body are joined to the side wings.

However, if there is a portion where the stretchable area of the outer body overlaps the side stretchable area of the inner body in the inner and outer joints, the side wings of the inner body will shrink in the width direction, causing the coverage width of the side wings to become narrower. In particular, if the coverage width of the side wings of the inner body at the back becomes narrower, the buttocks cannot be covered widely enough, so there is a problem that the inner body is easily caught in the buttocks seam.

[Prior technical literature] (Patent literature) Patent literature 1: Japanese Patent No. 5790031

[Problems that the invention aims to solve] Thus, the main problem that the invention aims to solve is to improve the coverage of the buttocks.

[Technical means for solving the problem] The shorts-type disposable diaper that solves the above-mentioned problem is as follows. ＜First embodiment＞ A shorts-type disposable diaper is characterized in that it has: a front outer body that constitutes at least the waistline of the front body; a rear outer body that constitutes at least the waistline of the rear body; an inner body including an absorbent body, which is arranged in a manner extending from the front outer body to the rear outer body; an inner-outer joint that connects the inner body to the front outer body and the rear outer body, respectively; a side seal that is formed by the two sides of the front outer body. The front outer body and the side parts of the aforementioned rear outer body are respectively joined together to form a waist opening and a pair of left and right leg openings; the aforementioned front outer body and the aforementioned rear outer body have a waist circumference stretching area that is elastically stretchable in the width direction, and the waist circumference stretching area includes the lower end portion of the part that is defined as the side closest to the leg opening when the front-to-back direction range having the aforementioned side sealing part is divided into four equal parts in the front-to-back direction; on the side parts of the aforementioned inner body, a waist opening that is more elastic than the aforementioned absorbent body is formed; The side wings extending laterally extend from the front outer body to the rear outer body in the front-rear direction; The side wings have a side stretchable area that is elastically stretchable in the front-rear direction at least in the portion overlapping with the front outer body and the portion overlapping with the rear outer body; The waist stretchable area of the rear outer body is provided with a portion that overlaps with at least the left and right side wings; The left and right side wings have a rear joint area that is connected to the waist and the rear outer body. The lower end of the rear outer body is partially joined together; The aforementioned rear joint area, together with the waistline stretching area of the aforementioned rear outer body, shrinks in the width direction and can stretch in the width direction; The tensile force when the lower end of the aforementioned front outer body is stretched in the width direction to the elastic limit and then shrinks to 3/4 of its size is greater than the tensile force when the lower end of the aforementioned rear outer body is stretched in the width direction to the elastic limit and then shrinks to 3/4 of its size.

(Effect) In the present shorts-type disposable diaper, the rear joint area of the side flaps shrinks in the width direction together with the waist stretching area of the rear outer body in the natural length (before wearing). Here, in the present shorts-type disposable diaper, the tensile force when the lower end of the front outer body is stretched in the width direction to the elastic limit and then shrinks to 3/4 of its size is greater than the tensile force when the lower end of the rear outer body is stretched in the width direction to the elastic limit and then shrinks to 3/4 of its size, so in the wearing state, the lower end of the rear outer body is stretched more (stretched longer) in the width direction than the lower end of the front outer body. As a result, the rear joint area of the side flaps is expanded more in the width direction, and the side flaps cover the buttocks more widely, making it less likely for the inner body to be caught in the buttock seam. In addition, "the tensile force when it is stretched to the elastic limit in the width direction and then contracted to 3/4 of its size" is the state of a general shorts-type disposable diaper when it is worn by a wearer of the appropriate size.

<Second Aspect> The shorts-type disposable diaper as described in the first aspect, wherein the tensile force when the lower end of the front outer body is stretched in the width direction to the elastic limit and then contracted to 3/4 of its size is 1.3 to 3.0 times the tensile force when the lower end of the rear outer body is stretched in the width direction to the elastic limit and then contracted to 3/4 of its size.

(Effect) Although the difference in tensile force between the lower end of the front exterior body and the lower end of the rear exterior body can be appropriately determined, it is generally preferred to be within the range of this embodiment.

<Third Aspect> The shorts-type disposable diaper as described in the first aspect or the second aspect, wherein the width dimension of the rear joining region is 0.8 to 1 times the width dimension of the side flap.

(Effect) Although the width dimension of the post-joining region can be appropriately determined, it is preferably sufficiently wide, and is usually preferably within the range of this embodiment.

<Fourth Aspect> A shorts-type disposable diaper as described in any of the first to third aspects, wherein the front outer body and the rear outer body are rectangular with the same dimensions in the front-to-back direction and the same dimensions in the width direction; The front-to-back dimensions of the front outer body and the rear outer body are 0.2 to 0.4 times the total length of the product.

(Effect) In order to reduce the amount of raw materials used in the outer body and to make a simple structure, it is preferred that the front outer body and the rear outer body are rectangular with the same dimensions in the front-to-back direction and the width direction. In this design, the appropriate front-to-back dimensions of the front outer body and the rear outer body are 0.2 to 0.4 times the total length of the product. At this time, although the coverage of the buttocks is reduced only in the rear outer body, the coverage of the buttocks can be compensated by the side wings of the aforementioned inner body.

<Fifth Aspect> A shorts-type disposable diaper as described in any of the first to fourth aspects, wherein the waist stretchable area of the front outer body is provided with a portion overlapping at least the left and right side flaps; The left and right side flaps have a front joining area joined to a portion including the lower end of the front outer body; The front joining area shrinks in the width direction together with the waist stretchable area of the front outer body and can be stretched in the width direction.

(Effect) In the present shorts-type disposable diaper, the front joint area of the side flaps shrinks in the width direction together with the waist stretch area of the front outer body in the natural length (before wearing). Here, in the present shorts-type disposable diaper, the tensile force when the lower end of the front outer body is stretched in the width direction to the elastic limit and then shrinks to 3/4 of its size is greater than the tensile force when the lower end of the rear outer body is stretched in the width direction to the elastic limit and then shrinks to 3/4 of its size, so that in the wearing state, the lower end of the rear outer body is stretched more (stretched longer) in the width direction than the lower end of the front outer body. As a result, although the front joining area of the side flap expands in the width direction, it does not expand more than the rear joining area, so the side flap can fit more appropriately to the groin than if the front and rear joining areas expanded to the same extent. <Sixth Aspect> A shorts-type disposable diaper as described in any of the first to fifth aspects, wherein the side stretchable area is an area in the side flaps where one or more side elastic members are arranged at intervals along the front-to-back direction; The side flaps have a hollow portion which is continuous along the side edges of the side flaps from the front joining area to the rear joining area in the front-to-back direction; and by contraction of the side elastic members, the portion of the side flaps including the hollow portion contracts in the front-to-back direction to form side wrinkles.

(Effect) In this shorts type disposable diaper, the side elastic member is contracted in the front-back direction along the part including the hollow part in the side flap to form the folds of the side pleats arranged in the front-back direction. Here, if the side pleats are formed in the part including the hollow part in the side flap, the folds of the side pleats are formed in a manner that the hollow part bulges greatly, and become very soft (that is, rich in cushioning) folds. Therefore, by means of this very soft fold, the skin touch of the side of the crotch becomes good (becomes fluffy and soft folds). In particular, as described above, when worn, the waist stretching area of the rear outer body is stretched more (longer) in the width direction than the waist stretching area of the front outer body, and the rear joint area of the side wings is more open in the width direction, so the bulge of the hollow part becomes closer to flat as it moves toward the rear joint area, and the fit to the buttocks becomes good. Furthermore, in the sixth state, the width of the side wings becomes narrower from the back to the front, and the bulge of the hollow part becomes larger from the back to the front, so the fit to the groin is also particularly good.

[Effects of the invention] According to the present invention, it has the advantages of improving the coverage of the buttocks.

Hereinafter, a detailed description will be given with reference to the attached drawings for an example of a shorts-type disposable diaper. The dot pattern portion in the cross-sectional view indicates that the adhesive as a joining means for joining the components located on the front side and the back side thereof is formed by applying the hot melt adhesive to the entire surface, in a linear pattern, in a curtain pattern, at a key position, or in a spiral pattern (transfer of the hot melt adhesive by relief printing), or the fixing portion of the elastic member is formed by applying the adhesive to the outer peripheral surface of the elastic member by using a comb-type spray gun or a rubber band nozzle instead of or together with the adhesive. As hot melt adhesives, there are EVA-based, adhesive rubber-based (elastic-based), olefin-based, polyester-polyamide-based adhesives, and other types of adhesives, and any of them can be used without particular limitation. As a means of joining the components together, a means based on welding the raw materials, such as heat sealing or ultrasonic sealing, can also be adopted.

Fig. 1 to Fig. 6 show an example of a shorts type disposable diaper. The shorts type disposable diaper comprises: a rectangular front outer body 12F constituting at least the waistline of the front body F; a rectangular rear outer body 12B constituting at least the waistline of the rear body B; and an inner body 200 provided on the outer bodies 12F and 12B in a manner extending from the front outer body 12F through the crotch to the rear outer body 12B. The two sides of the front outer body 12F and the two sides of the rear outer body 12B are joined together to form the side seal 12A, whereby the opening formed by the front and rear ends of the outer bodies 12F and 12B becomes the waist opening WO for the wearer's waist to pass through, and the parts surrounded by the lower edges of the outer bodies 12F and 12B and the side edges of the inner body 200 on both sides in the width direction of the inner body 200 become the leg openings LO for the legs to pass through. The inner body 200 is a part that absorbs and retains excreta such as urine, and the outer bodies 12F and 12B are parts for supporting the inner body 200 relative to the body of the wearer. In addition, the symbol Y represents the full length of the diaper in the unfolded state (the length in the front-to-back direction from the edge of the waist opening WO of the front body F to the edge of the waist opening WO of the back body B), and the symbol X represents the full width of the diaper in the unfolded state.

The present shorts type disposable diaper has a waist region T and a middle region L, wherein the waist region T is determined as the front-back direction range having the side seals 12A (the front-back direction range from the waist opening WO to the upper end of the leg openings LO), and the middle region L is determined as the front-back direction range of the portion forming the leg openings LO (between the front-back direction region having the side seals 12A of the front body F and the front-back direction region having the side seals 12A of the back body B). The waist region T can be conceptually divided into a "waist portion" W forming the edge of the waist opening and a "waist lower portion" U which is a portion below the waist. Generally, when there is a boundary in the waist region T where the tensile stress in the width direction WD changes (for example, the thickness and elongation of the elastic member change), the part closer to the waist opening WO than the boundary closest to the waist opening WO becomes the waist W. When there is no such boundary, the waist extension part 12E extending further to the waist opening WO than the absorbent body 56 or the inner body 200 becomes the waist W. The lengths of these in the front-back direction vary depending on the size of the product and can be appropriately determined. For example, the waist W can be 15 to 40 mm, and the lower waist part U can be 65 to 120 mm. On the other hand, the side edges of the middle region L are gathered in a U-shape or a curve shape along the wearer's legs, and this is the part where the wearer's legs are inserted. As a result, the overall shape of the shorts-type disposable diaper in the unfolded state is substantially an hourglass shape.

(Inner body) The inner body 200 can be in any shape, but in the illustrated examples, it is almost always rectangular. As shown in FIGS. 3 to 5 , the inner body 200 has: a top sheet 30 on the body side, a liquid-impermeable sheet 11, and an absorbent member 50 between the top sheet 30 and the liquid-impermeable sheet 11, and the inner body 200 has an absorption function. Reference numeral 40 indicates an intermediate sheet disposed between the top sheet 30 and the absorbent member 50 in order to allow the liquid that has passed through the top sheet 30 to move quickly to the absorbent member 50, and reference numeral 60 indicates upright pleats 60 extending from both sides of the inner body 200 in contact with the legs of the wearer in order to prevent excrement from leaking to both sides of the inner body 200.

The dimension of the inner body 200 in the width direction WD can be appropriately determined, and can be set to, for example, 1 to 1.5 times the dimension of the absorbent body 56 in the width direction WD.

(Top sheet) The top sheet 30 has a property of allowing liquid to pass through, and examples thereof include non-woven fabric with or without holes, porous plastic sheets, etc. Furthermore, the top sheet 30 may be composed of a single sheet, or a laminated sheet obtained by bonding two or more sheets. Similarly, the top sheet 30 may be composed of a single sheet, or may be composed of two or more sheets in the planar direction.

The side portions of the top sheet 30 may be folded back toward the back side at the side edges of the absorbent member 50 , or may not be folded back but extend further to the side than the side edges of the absorbent member 50 .

For the purpose of preventing the top sheet 30 from being displaced relative to the back side member, it is desirable to fix the top sheet 30 to the member adjacent to the back side by a joining method based on raw material welding such as heat sealing or ultrasonic sealing, or a hot melt adhesive. In the example shown in the figure, the top sheet 30 is fixed to the surface of the middle sheet 40 and the surface of the portion of the packaging sheet 58 located on the surface side of the absorbent body 56 by a hot melt adhesive applied to the back side thereof.

(Middle sheet) In order to make the liquid that has passed through the top sheet 30 move quickly to the absorbent body, a middle sheet (also called "second sheet") 40 whose liquid penetration speed is faster than the top sheet 30 can be provided. The middle sheet 40 is used for the following purposes: to make the liquid move quickly to the absorbent body 56 to improve the absorption performance of the absorbent body 56, and to prevent the absorbed liquid from seeping back from the absorbent body 56. The middle sheet 40 can also be omitted.

As the middle sheet 40, the same raw material as the top sheet 30, or spunlace nonwoven fabric, spunbond nonwoven fabric, SMS nonwoven fabric, pulp nonwoven fabric, mixed sheet of pulp and man-made fiber, point-bonded nonwoven fabric or spunlace paper can be exemplified. Hot air nonwoven fabric is particularly preferred because it is very bulky. For hot air nonwoven fabric, it is preferred to use a composite fiber with a core-sheath structure. In this case, the resin used for the core can be polypropylene (PP), but polyester (PET) with high rigidity is preferred. The weight per unit area is preferably 17 to 80 g/ ^m2 , and more preferably 25 to 60 g/ ^m2 . The coarseness of the raw fiber of the nonwoven fabric is preferably 2.0 to 10 dtex. In order to make the nonwoven fabric bulky, it is preferable to use an eccentric fiber whose core is not in the center, a hollow fiber, or an eccentric and hollow fiber as the mixed fiber for all or part of the raw fiber.

The middle sheet 40 shown in the figure is shorter than the width of the absorbent body 56 and is arranged in the center, but it can also be arranged to cover the entire width. The front-to-back length of the middle sheet 40 can be the same as the full length of the diaper, the same as the length of the absorbent member 50, or within a shorter length range centered on the liquid receiving area.

For the purpose of preventing the position of the intermediate sheet 40 from shifting relative to the back side member, it is desirable to fix the intermediate sheet 40 to the member adjacent to the back side by means of a joining method based on raw material welding such as heat sealing or ultrasonic sealing, or by a hot melt adhesive. In the example shown in the figure, the intermediate sheet 40 is fixed to the surface of the portion of the packaging sheet 58 located on the surface side of the absorbent body 56 by means of a hot melt adhesive applied to the back side thereof.

(Liquid-impermeable sheet) The raw material of the liquid-impermeable sheet 11 is not particularly limited, and examples thereof include a plastic film made of an olefin resin such as polyethylene or polypropylene, a laminated nonwoven fabric formed by providing a plastic film on the surface of a nonwoven fabric, and a laminated sheet formed by overlapping and joining nonwoven fabrics on a plastic film. For the liquid-impermeable sheet 11, it is preferable to use a material having liquid-impermeability and moisture-permeability suitable for use from the perspective of preventing dampness. As a moisture-permeable plastic film, a microporous plastic film obtained by mixing an inorganic filler in an olefin resin such as polyethylene or polypropylene, molding it into a sheet, and extending it along one or two axes is widely used. In addition, as the liquid-impermeable sheet 11, a sheet having liquid-impermeability without using a plastic film can also be used. This sheet achieves liquid-impermeability by the following methods: using a non-woven fabric using microdenier fibers; applying heat or pressure to reduce the gaps between the fibers to enhance leak-proofness; and applying a highly absorbent resin or a hydrophobic resin or a water repellent. However, in order to obtain sufficient bonding strength when bonding with the mask non-woven fabric 13 described later by a hot-melt adhesive, it is desirable to use a resin film.

The liquid-impermeable sheet 11 is formed to have a width to be accommodated on the back side of the absorbent member 50 as shown in the figure, but in order to improve the leakage prevention, it can also be wrapped around both sides of the absorbent member 50 and extended to both sides of the absorbent member 50 on the side of the top sheet 30. The width of this extension part is preferably about 5 to 20 mm on both sides.

(Absorbent member) The absorbent member 50 includes an absorbent body 56 and a wrapping sheet 58 that wraps the entire absorbent body 56. The wrapping sheet 58 may also be omitted.

(Absorbent) The absorbent 56 may be formed of a fiber aggregate. As this fiber aggregate, in addition to an aggregate formed by fiberizing short fibers such as cotton pulp or synthetic fibers, a filament aggregate obtained by opening a tow (fiber bundle) of synthetic fibers such as cellulose acetate as needed may be used. The weight per unit area of the fibers may be, for example, 100 to 300 g/ ^m2 in the case of fiberizing cotton pulp or short fibers, and may be, for example, 30 to 120 g/ ^m2 in the case of a filament aggregate. In the case of synthetic fibers, the thickness is, for example, 1 to 16 dtex, preferably 1 to 10 dtex, and more preferably 1 to 5 dtex. In the case of a filament aggregate, the filaments may be non-curled fibers, but are preferably curly fibers. The curvature of the curly fibers may be, for example, 5 to 75 per 2.54 cm, preferably 10 to 50, and more preferably about 15 to 50. In addition, uniformly curled curly fibers may be used. It is preferred that highly absorbent polymer particles are dispersed and retained in the absorbent body 56.

The absorbent body 56 may be rectangular in shape, but it is preferably formed into an hourglass shape with a gathering portion 56N in the middle of the front-to-back direction whose width is narrower than the front and rear sides of the middle of the front-to-back direction as shown in FIG. 7 . This improves the fit of the absorbent body 56 itself and the standing pleats 60 around the legs.

The size of the absorber 56 can be appropriately determined, but preferably extends from the position overlapping with the front outer body through the crotch to the position overlapping with the rear outer body, and can extend to the periphery of the inner body 200 or its vicinity in the front-rear direction LD and the width direction WD as shown in the example shown in the figure. In addition, the reference numeral 56X represents the full width of the absorber 56.

(High absorbent polymer particles) A part or all of the absorbent body 56 may contain high absorbent polymer particles. High absorbent polymer particles include "powder" in addition to "particles". As high absorbent polymer particles, particles used in such disposable diapers can be used directly. For example, particles whose proportion of particles remaining on the sieve in sieving (vibrating for 5 minutes) using a 500μm standard sieve (JISZ8801-1:2006) is 30% by weight or less are desirable. Also, particles whose proportion of particles remaining on the sieve in sieving (vibrating for 5 minutes) using a 180μm standard sieve (JISZ8801-1:2006) is 60% by weight or more are desirable.

The material of the superabsorbent polymer particles can be used without particular limitation, but preferably a material having a water absorption of 40 g/g or more. The superabsorbent polymer particles include starch-based, cellulose-based, and synthetic polymer-based superabsorbent polymer particles, and superabsorbent polymer particles such as starch-acrylic acid (salt) graft polymer, starch-acrylonitrile copolymer saponification product, carboxymethyl cellulose sodium crosslinked product, and acrylic acid (salt) polymer can be used. The shape of the superabsorbent polymer particles is preferably a commonly used powdery granular form, but other shapes can also be used.

As the superabsorbent polymer particles, it is preferred to use superabsorbent polymer particles having a water absorption rate of 70 seconds or less, particularly preferably 40 seconds or less. If the water absorption rate is too slow, the liquid supplied to the absorbent body 56 is likely to return to the outside of the absorbent body 56, which is called backflow.

Furthermore, as the superabsorbent polymer particles, it is preferable to use superabsorbent polymer particles having a gel strength of 1000 Pa or more. Thereby, even when the absorbent body 56 is formed into a swollen state, the sticky feeling after liquid absorption can be effectively suppressed.

The weight per unit area of the superabsorbent polymer particles can be appropriately determined according to the absorption amount required by the use of the absorbent body 56. Therefore, it cannot be generally determined, but it can be 50 to 350 g/ ^m2 . If the weight per unit area of the polymer is less than 50 g/ ^m2 , it is difficult to ensure the absorption amount. If the weight per unit area of the polymer exceeds 350 g/ ^m2 , the effect is saturated.

(Packaging sheet) When the packaging sheet 58 is used, as its raw material, tissue paper, particularly wadding paper, nonwoven fabric, laminated nonwoven fabric, sheet with small holes, etc. can be used. However, it is desirable to use a sheet from which the superabsorbent polymer particles do not fall out. When nonwoven fabric is used instead of wadding paper, hydrophilic SMS nonwoven fabric (SMS, SSMMS, etc.) is particularly preferred, and its material can be polypropylene, polyethylene/polypropylene composite material, etc. The desired weight per unit area is 5 to 40 g/ ^m2 , and particularly 10 to 30 g/ ^m2 is desirable.

The packaging method of the packaging sheet 58 can be appropriately determined, but from the perspective of ease of manufacturing and preventing superabsorbent polymer particles from leaking out from the front and rear edges, the following method is preferred: the packaging sheet 58 is rolled into a tube in a manner that surrounds the surface, back surface and two sides of the absorbent body 56, and its front and rear edges are exposed from the front and rear of the absorbent body 56, and the overlapping parts of the rolled parts and the overlapping parts of the front and rear exposed parts are joined together by hot-melt adhesives, raw material welding, or other joining means.

(Standing pleats) The standing pleats 60 have a standing portion 68 standing up from the side of the inner body 200. The standing portion 68 contacts the range from the groin of the wearer through the leg circumference to the buttocks and prevents side leakage. In the standing pleats 60 shown in the figure, the root side portion 60B stands up obliquely toward the center side in the width direction, and the front side portion 60A stands up obliquely from the middle portion further toward the outside in the width direction, but it is not limited to this, and it can also be a suitable change such as a method of standing up toward the center side in the width direction as a whole.

To explain in more detail, the standing gathers 60 shown in the figure are constructed as follows: a strip-shaped gathered sheet 62 having a length equal to the length of the inner body 200 in the front-rear direction is folded back in the width direction WD at the portion that becomes the front end and folded into two parts, and a plurality of thin elongated gathered elastic members 63 are fixed at intervals in the width direction WD in a state of being stretched in the length direction between the folded portion and the adjacent sheet. The base end portion (the end portion on the side opposite to the sheet folded back portion in the width direction WD) of the standing gathers 60 located on the side opposite to the front end portion is a root portion 65 fixed to the side of the inner body 200, and the portion other than the root portion 65 is a main body portion 66 (the portion on the folded back portion side) extending from the root portion 65. The main body portion 66 has a root side portion 60B extending toward the center side in the width direction, and a front side portion 60A folded back at the front end of the root side portion 60B and extending toward the outside in the width direction. In addition, the front and rear ends of the main body portion 66 are lying portions 67 fixed relative to the side surface of the top sheet 30 in a lying state, and the middle portion in the front and rear direction between them is a non-fixed standing portion 68, and the wrinkled elastic member 63 along the front and rear direction LD is fixed to at least the front end of the standing portion 68 in an extended state.

In the standing gathers 60 constructed as described above, the contraction force of the gather elastic member 63 causes the standing portion 68 to stand up in a manner that contacts the skin as indicated by the arrow mark in FIG. 3 .

In the curved structure of the main body portion 66 composed of the root side portion 60B extending toward the center side in the width direction and the front side portion 60A folded back at the front end of the root side portion 60B and extending toward the outside in the width direction, the front side portion 60A and the root side portion 60B are joined together in a fallen state at the fallen portion 67, and the root side portion 60B is joined to the top sheet 30 in a fallen state. For joining the opposing surfaces in the fallen portion 67, at least one of hot melt adhesives based on various coating methods and means based on welding of raw materials such as heat sealing and ultrasonic sealing can be adopted. At this time, the root side portion 60B and the top sheet 30 and the front side portion 60A and the root side portion 60B may be joined by the same means or by different means. For example, it is preferred to join the root side portion 60B and the top sheet 30 by hot melt adhesive and to join the front side portion 60A and the root side portion 60B by welding of raw materials.

As the wrinkled sheet 62, a wrinkled sheet made by water-repelling a soft non-woven fabric (SS, SSS, etc.), SMS non-woven fabric (SMS, SSMMS, etc.), melt-blown non-woven fabric, etc., which is excellent in uniformity and concealment, using silicone or the like as needed can be appropriately used. At this time, the weight per unit area of the fiber of the non-woven fabric is preferably about 10 to 30 g/ ^m2 . As the wrinkled elastic member 63, a rubber thread or the like can be used. When a polyurethane rubber thread is used, the thickness is preferably 470 to 1240 dtex, and more preferably 620 to 940 dtex. The elongation of the wrinkled elastic member 63 in the installed state is preferably 150 to 350%, more preferably 200 to 300%. The number of wrinkled elastic members 63 is preferably 2 to 6, more preferably 3 to 5. The arrangement interval 60d of the wrinkled elastic member 63 is appropriately 3 to 10 mm. If it is configured like this, it is easy to contact the skin with the surface within the range where the wrinkled elastic member 63 is arranged. The wrinkled elastic member 63 can be arranged not only on the front side but also on the root side.

At the rising portion 68 of the rising pleats 60, at least one of hot melt adhesives based on various coating methods and fixing means based on welding of raw materials such as heat sealing or ultrasonic sealing can be used for bonding the inner layer and the outer layer of the pleated sheet 62 or fixing the pleated elastic member 63 sandwiched therebetween. If the inner layer and the outer layer of the pleated sheet 62 are bonded to each other over the entire surface, the flexibility will be impaired. Therefore, it is preferable not to bond or to weakly bond the portion other than the bonding portion of the pleated elastic member 63. In the example shown in the figure, the structure is as follows: the hot melt adhesive is applied only on the outer peripheral surface of the corrugated elastic member 63 by using a comb-type spray gun or a rubber band nozzle, and the corrugated elastic member 63 is sandwiched between the inner layer and the outer layer of the corrugated sheet 62, thereby fixing the corrugated elastic member 63 relative to the inner layer and the outer layer of the corrugated sheet 62, and fixing the inner layer and the outer layer of the corrugated sheet 62 to each other using only the hot melt adhesive applied to the outer peripheral surface of the corrugated elastic member 63.

Similarly, for fixing the fallen portion 67, at least one of a hot melt adhesive based on various coating methods and a means based on welding of raw materials such as heat sealing or ultrasonic sealing can be used.

(Side wings) Side wings 70 extending from the sides of the absorber 56 are provided on both sides of the inner body 200. As shown in the example in the figure, each side wing 70 is preferably formed as a flat portion extending only to the side without folding back. The dimension of each side wing 70 in the width direction WD can be appropriately determined, for example, it can be set to 0.1 to 0.2 times the dimension of the inner body 200 in the width direction WD.

In addition, each side wing 70 has a side stretchable area SG that is elastically stretchable in the front-rear direction LD at least between the portion overlapping the front outer body 12F and the portion overlapping the rear outer body 12B. The side stretchable area SG is an area in which one or a plurality of side elastic members 73 are provided along the front-rear direction LD, and the side elastic members can be contracted and stretched in the front-rear direction. Furthermore, each side wing 70 preferably has a hollow portion 70H that is continuous in the front-rear direction LD along the side edge of the side wing 70. By contraction of the side elastic member 73, the portion of the side flap 70 including the hollow portion 70H contracts in the front-rear direction LD, so that a plurality of folds are arranged in the front-rear direction LD to form side wrinkles. Here, if the portion of the side flap 70 including the hollow portion 70H is formed with side wrinkles, as shown in FIG. 6 , the folds of the side wrinkles are formed in such a way that the hollow portion 70H bulges greatly, and become very soft (that is, rich in cushioning) folds. Therefore, by means of such very soft folds, the skin touch of the side of the crotch becomes good (becomes fluffy and soft folds).

In order to fix the side elastic member 73 , the side wing 70 preferably has a first layer 71 on the back side facing the side elastic member 73 and a second layer 72 on the surface side facing the side elastic member 73 .

The sheet material for forming the first layer 71 and the second layer 72 is not particularly limited, and a suitable nonwoven fabric such as a nonwoven fabric that can be used for the aforementioned standing pleats 60 or the aforementioned outer body 12F, 12B can be selected. In the examples shown in Figs. 3, 4, and 11, the first layer 71 and the second layer 72 are formed by extending the pleated sheet 62 of the standing pleats 60 as described later. As shown in Figs. 9, 10, and 12, a dedicated sheet 79 different from the standing pleats 60 may be added to construct the side flap 70. In the former case, the front and rear ends of the side wings 70 may be consistent with the front and rear ends of the standing pleats 60 (that is, the front and rear ends of the inner body 200 in this case); in the latter case, the front and rear ends of the side wings 70 may be located closer to the center side in the front-to-rear direction than the front and rear ends of the standing pleats 60.

The side elastic member 73 is not particularly limited, and the same elongated elastic member as the aforementioned wrinkled elastic member 63 can be used. The elongation of the side elastic member 73 in the side expansion and contraction area SG in the expanded state is preferably 150 to 350%, and more preferably 200 to 270%. The number of the side elastic members 73 is preferably 2 to 16, and more preferably 6 to 10. The configuration interval of the side elastic members 73 is appropriately 5 to 10 mm. It is particularly preferred that a plurality of side elastic members 73 are provided at intervals in the width direction WD, and the elongation of the side elastic members 73 in the side stretchable region SG in the expanded state is lower as the elongation of the side elastic members 73 closer to the side is lower, so that the side stretchable region SG rises more slowly toward the skin side, and the side stretchable region SG is more likely to be in a proper wearing state, which is preferred. If the side stretchable region SG rises more sharply, the side flaps 70 are folded back inward and caught between the leg and the surface of the disposable article, which may cause leakage.

The side elastic member 73 is fixed to the first sheet 71 and the second sheet 72. For the bonding of the first sheet 71 and the second sheet 72, or the fixing of the side elastic member 73 sandwiched therebetween, a fixing means based on the welding of raw materials such as hot melt adhesive HM based on various coating methods or heat sealing, ultrasonic sealing, etc. can be adopted. If the bonding area of the first sheet 71 and the second sheet 72 is large, the flexibility will be impaired, so it is better not to bond or to bond weakly the part other than the bonding part of the side elastic member 73. In the example shown in the figure, the following structure is formed: by using a coating means such as a comb-type spray gun or a rubber band nozzle, the hot melt adhesive HM is coated only on the outer peripheral surface of the side elastic member 73 and the side elastic member 73 is sandwiched between the first layer 71 and the second layer 72, thereby using only the hot melt adhesive HM coated on the outer peripheral surface of the side elastic member 73 to fix the side elastic member 73 relative to the first layer 71 and the second layer 72, and to fix the first layer 71 and the second layer 72 to each other.

The installation range of the side elastic member 73 in the front-to-back direction LD, that is, the range of the side expansion and contraction zone SG in the front-to-back direction LD, is preferably formed from the portion overlapping with the front outer body 12F to the portion overlapping with the rear outer body 12B, as shown in the example in the figure, but is not limited to this. Therefore, for example, the front end of the side expansion and contraction zone SG is located at the rear end of the front outer body, or it can also be located at a position further to the rear side than the rear end. Similarly, the rear end of the side expansion and contraction zone SG is located at the front end of the rear outer body, or it can also be located at a position further to the front side than the front end. In addition, the range of the side expansion and contraction zone SG in the front-to-back direction LD is preferably the same as the contraction portion generated by the wrinkle elastic member 63 of the upright wrinkles 60, or extends further to the front and rear sides than the contraction portion.

The side flap 70 preferably has three or more layers, including a first layer 71 and a second layer 72. In other words, it preferably has at least one inner layer 76 between the first layer 71 and the second layer 72, in addition to the layer 74 closest to the front side and the layer 75 closest to the back side. Some or all of these layers may be formed using separate sheets, or may be formed by folding a sheet once or multiple times. The inner sheet layer 76 can be appropriately selected from nonwoven fabrics similar to the aforementioned pleated sheet 62, the liquid-impermeable sheet 11, or the outer bodies 12F and 12B described later, or can be formed by appropriately extending or folding the aforementioned pleated sheet 62 or the liquid-impermeable sheet 11.

The structure of the hollow portion 70H is not particularly limited, and can be formed, for example, by the following layer stacking structure. That is, in the side flap 70 shown in the figure, a non-joined portion 77 is formed, which is not joined to the inner layer 76 of the layer overlapping the at least one of the layer 74 on the most surface side and the layer 75 on the most back side. This non-joined portion 77 is a continuous or intermittent portion in the front-rear direction LD within the range of the width direction WD of the area between the side elastic member 73 located most on the side and the side edge of the side flap 70. That is to say, as long as either the layer 74 closest to the surface side or the layer 75 closest to the back side is not bonded to the inner layer 76 of the layer overlapping either side, part or all of the layers outside the non-bonded portion 77 may be bonded, and all the layers in the thickness direction may be non-bonded. For example, in the non-bonding portion 77 of the examples shown in Figures 3, 4 and 11, the non-bonding portion of the layer 74 closest to the surface side and the inner layer 76 overlapping the layer 74 closest to the surface side is from the side edge to the fixed position of the side elastic component 73 closest to the side; the non-bonding portion of the layer 75 closest to the back side and the inner layer 76 overlapping the layer 75 closest to the back side is more continuous than the fixed position of the side elastic component 73 closest to the side to the center side in the width direction. In the non-bonded portion 77 of the examples shown in Figures 9, 10 and 12, the non-bonded portion of the layer 74 closest to the surface and the inner layer 76 overlapping the layer 74 closest to the surface, as well as the layer 75 closest to the back side and the non-bonded portion of the inner layer 76 overlapping the layer 75 closest to the back side, are both continuous from the side edge to the center side in the width direction that is more continuous than the fixed position of the side elastic member 73 closest to the side, but the former is more continuous to the center side in the width direction.

The dimension of the non-joined portion 77 in the width direction WD can be appropriately determined, but is preferably 2 to 15 mm, and particularly preferably 5 to 10 mm. In other words, the dimension of the hollow portion 70H in the width direction WD is preferably 2 mm or more. As shown in the example shown in the figure, when there are standing wrinkles 60, the edge of the center side of the width direction WD of the non-joined portion 77 is preferably located more laterally than the boundary between the root portion 65 and the main portion 66 (the starting point of the standing). In addition, the dimension of the non-joined portion 77 in the front-to-back direction LD (the dimension of the hollow portion 70H in the front-to-back direction) is preferably 30% or more of the total length Y of the product, and particularly preferably 40% or more of the total length Y of the product. Furthermore, in the case of a shorts-type disposable article of clothing in which the front outer body 12F and the rear outer body 12B are separated as shown in the example in the figure, it is preferable that the non-joined portion 77 extends to a position overlapping the front outer body 12F and the rear outer body 12B, respectively. In this case, it is preferable that the non-joined portion 77 extends over the entire front-rear direction LD of the inner body 200. It is also preferable that the non-joined portion 77 extends only to the front and rear edges of the inner body 200, and to a position between the elastic members 16 and 19 on the side closest to the leg opening LO of the front outer body 12F and the rear outer body 12B. Furthermore, the non-joined portion 77 may extend only to a position between the elastic members 16, 19 of the front exterior body 12F and the rear exterior body 12B closest to the leg opening LO and the edge of the leg opening LO (the rear edge of the exterior body 12F and the front edge of the rear exterior body 12B).

Furthermore, on both sides of the width direction WD of the non-joined portion 77, the gap between at least one of the sheet layer 74 closest to the surface side and the sheet layer 75 closest to the back side and the inner sheet layer 76 superimposed on the at least one sheet layer is closed. As shown in the example in the figure, one side of the gap of the non-joined portion 77 can be closed by folding back the sheet material forming the sheet layer 74 closest to the surface side or the sheet layer 75 closest to the back side at the side edge of the side flap 70. Furthermore, the other side of the gap of the non-joined portion 77 can be closed by joining the adjacent sheets in the thickness direction at appropriate locations using a hot melt adhesive HM or welding means. Of course, both sides of the gap of the non-joined portion 77 can also be sealed by the same method, such as folding back the sheet or hot melt adhesive HM.

As shown in the example of the figure, a non-joined portion 77 is formed with both sides in the width direction WD closed, and if this non-joined portion 77 is continuous in the front-rear direction LD in the width direction WD range (the same or larger width direction WD range as this region) of the region between the side elastic member 73 closest to the side and the side edge of the middle region L, then the hollow portion 70H surrounded by the sheet in the side edge of the side wing becomes continuous in the front-rear direction LD. At this time, the fold formed on the side of the side wing is formed by at least one of the sheet 74 closest to the surface side and the sheet 75 closest to the back side with a large bulge, and becomes a very soft (that is, rich in cushioning) fold. Therefore, since the very soft folds are formed on the inner side, outer side, both inner and outer sides, or the entire thickness direction of the range including the side edges of the side wings 70, the skin touch of the end of the leg opening LO becomes good.

The side elastic member 73 may be located near the side edge of the side wing 70, but preferably, the side elastic member 73 is not included in the portion within the range of 2 to 15 mm (particularly preferably 5 to 10 mm) from the side edge to the center side in the width direction WD of the side wing 70. Furthermore, preferably, the portion within the range of 2 to 15 mm (particularly preferably 5 to 10 mm) from the side edge to the center side in the width direction WD includes a part or all of the hollow portion 70H. In this way, if the side elastic members 73 are sufficiently separated from the side edges of the side wings 70, when the product is held during wearing or purchase, or when the skin is pressed during wearing (that is, the part with the side elastic members 73), a large fold with rich softness and cushioning properties is formed in the entire thickness direction of the side, so it is particularly good in improving the skin feel of the end of the leg opening LO. This effect is particularly significant when the side elastic members 73 are sufficiently separated from the side edges of the side wings 70 and a part or all of the hollow part 70H is included in the separated part.

The positional relationship between the hollow portion 70H and the side elastic member 73 can be appropriately determined. However, if, as shown in the example shown in the figure, there is at least one side elastic member 73 on the surface side of the hollow portion 70H, the contraction force of the side elastic member 73 will be directly applied to the hollow portion 70H, so that the shape maintenance of the folds in the hollow portion 70H becomes higher, which is better.

In the non-joined portion 77, the inner layer 76 superimposed on the layer 74 closest to the surface or on the back of the layer 75 closest to the back side may also be fixed to the adjacent layer on the opposite side as shown in FIG. 12 (the first layer 71 and the first layer 72 in the illustrated example are bonded to each other using a hot melt adhesive HM), and the inner layer 76 shown in FIG. 11 is particularly preferred, which is non-fixed relative to the adjacent layers on both sides in the thickness direction. In other words, the hollow portion 70H divided by the inner layer 76 is preferably provided in a plurality of overlapping portions in the thickness direction. Thus, independent folds are formed in the portions between the plurality of hollow portions 70H, and these folds overlap, so that folds with better cushioning properties can be formed on the sides of the side wings 70.

As shown in the example of the figure, the side flap 70 has a folded sheet layer that is folded back at the side edge of the side flap 70 from the portion of the hollow portion 70H located on the surface side to the portion of the hollow portion 70H located on the back side. If the hollow portion 70H extends laterally to the folded position of the folded sheet layer, the cushioning property of the fold formed in the hollow portion 70H is particularly improved by the restoring force against the folding, which is preferred. In addition, the folded layer refers to a pair of layers formed by folding back the sheet material.

A preferred example is a structure as shown in Fig. 3, Fig. 4 and Fig. 11. This side wing 70 has two layers of folded sheet layers folded back at its side edge, and the sheet layer 74 closest to the surface side and the sheet layer 75 closest to the back side of the non-joined portion 77 are respectively formed into a surface side portion and a back side portion with the folded position of the folded sheet layer located outside as a boundary. In addition, the side elastic member 73 is fixed to a position farther from the center side of the width direction WD than the folded position between the surface side portion with the folded position of the folded sheet layer located outside as a boundary and the surface side portion with the folded position of the folded sheet layer located inside as a boundary. Furthermore, between the side elastic member 73 located most to the side and the side edge of the side flap 70, all the adjacent layers (four layers) in the thickness direction are not joined, thereby forming a hollow portion 70H between each layer. In this structure, a three-stage (three chambers in the thickness direction) hollow portion 70H can be formed at least on the side of the side flap 70. At this time, the two layers of the folded-back layer each have a restoring force for folding back, so that a fold with better cushioning performance can be formed on the side of the side flap 70 using less sheet material.

Other preferred examples are structures shown in Figures 9, 10 and 12. The side flap 70 is folded back at its side edge to have two folded back sheets, and sandwiches the first sheet 71 and the second sheet 72 of the side elastic member 73, and includes a portion on one side and a portion on the other side respectively with the folded position of the inner folded back sheet as a boundary (that is, either the first sheet 71 or the second sheet 72 is the inner sheet 76). Furthermore, the non-joined portion 77 is a portion where the sheet 74 closest to the front side and the second sheet 72 overlapped therewith are not joined, and a portion where the sheet 75 closest to the back side and the first sheet 71 overlapped therewith are not joined, and the hollow portion 70H extends laterally to the folded position of the folded-back sheet located outside. In this structure, the hollow portion 70H is formed on both the front and back sides of the side portion of the side flap 70, thereby forming large folds on both the front and back sides, respectively, so that the skin touch of the side portion of the side flap 70 becomes good. In addition, since the side elastic member 73 is covered by two layers of folded sheet layers, the touch of the side elastic member 73 is not easily transmitted to the skin, making the skin touch particularly good. Furthermore, the sheet layer 74 closest to the surface side and the sheet layer 75 closest to the back side are the part on one side and the part on the other side with the folded position of the folded sheet layer located outside as the boundary, so the cushioning property of the fold formed in the part having the hollow part 70H is also excellent due to the restoring force against the folding.

Although not shown, the side elastic member 73 in the structure shown in Fig. 3, Fig. 4 and Fig. 11 may be located between the back side portion bordered by the folded position of the outer folded sheet layer and the back side portion bordered by the folded position of the inner folded sheet layer. In other words, the side elastic member 73 may be installed at the back side portion of the hollow portion 70H.

As in these examples, when the non-joined portion 77 is formed into a four-layer structure of a sheet, as in the example shown in Fig. 11, it is preferable to construct the side flap 70 using the sheet of the standing pleats 60. That is, the folded sheet layer of the side flap 70 can be formed by the first portion P1, which is a portion of the two-layer structure of the pleated sheet 62 of the standing pleats 60 extending from the root portion 65 of the standing pleats 60 to the side edge of the side flap 70, and the second portion P2, which is a portion of the two-layer structure of the pleated sheet 62 of the standing pleats 60 folded back at the side edge of the side flap 70 and extending to the center side in the width direction.

(Mask nonwoven fabric) In the two-part outer shorts type disposable diaper, since the inner body 200 is exposed between the front outer body 12F and the rear outer body 12B, it is preferable to provide a mask nonwoven fabric 13 in a manner that does not expose the liquid-impermeable sheet 11 on the back of the inner body 200. The mask nonwoven fabric 13 extends from between the front outer body 12F and the inner body 200 to between the rear outer body 12B and the inner body 200 on the back of the inner body 200. The inner surface and the outer surface of the mask nonwoven fabric 13 can be bonded to their respective opposite surfaces by a hot melt adhesive. The nonwoven fabric used for the mask nonwoven fabric 13 can be appropriately selected from the same raw materials as those of the outer bodies 12F and 12B.

(Exterior body) Exterior body 12F, 12B is composed of a rectangular front exterior body 12F which constitutes at least the waistline of the front body F, and a rectangular rear exterior body 12B which constitutes at least the waistline of the back body B. The front exterior body 12F and the rear exterior body 12B are discontinuous on the crotch side and are separated in the front-to-back direction LD (exterior body divided into two). The separation distance 12d in the front-to-back direction can be set to, for example, 40 to 60% of the total length Y. In the example shown in the figure, the lower edges of the front exterior body 12F and the rear exterior body 12B are formed in a straight line along the width direction WD, but the lower edge of at least one of the front exterior body 12F and the rear exterior body 12B can also be formed in a curved line along the leg circumference.

The outer bodies 12F and 12B have a front-to-back direction range corresponding to the waist region T, that is, the waist region. Again, in this example, the front-to-back direction dimension of the front outer body 12F is the same as the front-to-back direction dimension of the rear outer body 12B. It is also possible to have a structure as shown in FIG8 , in which the front-to-back direction dimension of the rear outer body 12B is longer than the front-to-back direction dimension of the front outer body 12F, a buttocks shielding portion C extending from the waist region T to the middle region L is provided on the rear outer body 12B, and the front outer body 12F does not have a portion corresponding to the middle region L. In this case or in contrast to this case, although not shown, a groin shielding portion extending from the waist region T to the middle region L can also be provided on the front outer body 12F.

As shown in Fig. 4 and Fig. 5, the outer body 12F, 12B has an inner layer 12H and an outer layer 12S, and elastic members 16 to 19 disposed between these layers. Each layer can be made into a common sheet or an individual sheet. That is, in the former case, in part or all of the front outer body 12F and the rear outer body 12B, the elastic members 16 to 19 are disposed between the inner and outer portions of a sheet that can be folded back at appropriate positions such as the edge of the waist opening WO or the edge of the leg opening LO. In the example shown in the figure, the waist W has a folded portion including each sheet. For example, in the waist portion W, the sheet forming the outer layer 12S extends only to the edge of the waist opening WO, but the sheet forming the inner layer 12H is wrapped around the edge of the waist side of the sheet forming the second layer and folded back to the inner side thereof. Moreover, this folded back portion becomes the inner cover layer 12r extending in the width direction of the entire outer body to the position overlapping with the end of the waist opening WO side of the inner body 200. The inner cover layer 12r may be formed not by folding back the sheet forming the inner layer 12H, but by attaching a dedicated sheet.

In order to improve the fit to the waist of the wearer, the elastic members 16 to 19 are built into the waist of the outer body 12F and 12B to form a waist stretching area A2 (area having the elastic members 16 to 19), which can be elastically stretched in the width direction WD along with the stretching of the elastic members. The waist stretching area A2 is set in a manner to include the lower end 14 of the part defined as the side closest to the leg opening LO when the waist part (the front-back direction range having the side seal part 12A) in the front outer body 12F and the rear outer body 12B is divided into four equal parts in the front-back direction. In addition, the waist stretching area A2 of the rear outer body 12B is set in a manner to include the part overlapping with the left and right side flaps 70. Similarly, the waist stretch area A2 of the front outer body 12B is provided so as to include the portion overlapping with the left and right side flaps 70. In the waist stretch area A2, the outer bodies 12F and 12B shrink as the elastic members shrink in the natural length, thereby forming wrinkles or pleats, and when the elastic members are stretched in the longitudinal direction, they can be stretched to a predetermined elongation rate to fully stretch without wrinkles. The elastic members 16 to 19 are not particularly limited, and in addition to being able to use thin and long elastic members such as rubber threads (as shown in the figure), known elastic members such as belts, nets, and films can also be used. As the elastic members 16 to 19, synthetic rubber such as spandex may be used, or natural rubber may be used.

If the elastic members 16 to 19 of the illustrated example are described in more detail, a plurality of waist elastic members 17 are installed in the waist portion W of the outer body 12F, 12B in a continuous manner throughout the width direction WD and at intervals in the front-rear direction. In addition, one or more of the waist elastic members 17 disposed in the region adjacent to the lower waist portion U may overlap with the inner body 200, or may be disposed on both sides in the width direction except for the central portion in the width direction overlapping with the inner body 200. As the waist elastic member 17, 2 to 15, preferably 4 to 10 rubber threads of a thickness of 155 to 1880 dtex, preferably 470 to 1240 dtex (in the case of synthetic rubber, the cross-sectional area is 0.05 to 1.5 ^mm2 , preferably 0.1 to 1.0 mm2 in the case of natural rubber) are provided at intervals of ² to 12 mm, preferably 3 to 7 mm. The elongation of the waist W in the width direction WD obtained thereby is preferably 150 to 400%, preferably 220 to 320%. Furthermore, the waist W does not need to have the same thickness of the waist elastic component 17 or the same elongation in the entire front-to-back direction LD. For example, the thickness or elongation of the waist elastic component 17 can be different in the upper and lower parts of the waist W.

Furthermore, it is preferred that a plurality of elastic members 16 and 19 below the waist formed of elongated elastic members are installed at intervals in the front-rear direction in the below-waist portion U of the exterior bodies 12F and 12B. The lower waist elastic members 16, 19 are preferably 5 to 30 rubber cords having a thickness of 155 to 1880 dtex, particularly preferably 470 to 1240 dtex (in the case of synthetic rubber, the cross-sectional area is 0.05 to ^1.5 mm2, particularly preferably 0.1 to 1.0 mm2 in the case of natural rubber) arranged at intervals of 1 to 15 mm, particularly preferably ³ to 8 mm. The elongation of the lower waist portion U in the width direction WD obtained thereby is preferably 200 to 350%, particularly preferably 240 to 300%.

Furthermore, as shown in Figure 8, when a buttocks cover portion C is provided on the rear outer body 12B, or although not shown, when a groin cover portion is provided on the front outer body 12F, an elastic member similar to that below the waist can be provided, thereby preferably setting the elongation in the width direction WD to 150 to 300%, particularly preferably to 180 to 260%.

As in the example of the lower waist U, when the elastic members 16 and 19 are preferably provided in the front-back direction range of the absorbent body 56, in order to prevent the absorbent body 56 from shrinking in the width direction WD, the middle of the width direction (preferably including the entire inner and outer joints 201 and 202) including part or all of the part overlapping with the absorbent body 56 in the width direction WD is provided as a non-stretching area A1, and both sides in the width direction are provided as waist circumference stretching areas A2. The waist W is preferably provided as the waist circumference stretching area A2 throughout the entire width direction WD, but the non-stretching area A1 may be provided in the middle of the width direction like the lower waist U.

Such waist stretch zone A2 and non-stretch zone A1 can be constructed in the following manner: elastic components 16 to 19 are supplied between the inner sheet 12H and the outer sheet 12S, and after the elastic components 16 and 19 are fixed only in the portion located in the waist stretch zone A2 by hot-melt adhesive, the elastic components 16 and 19 are cut by pressurizing and heating at a point in the middle in the width direction in the area having the absorbent body 56, or almost the entire elastic components 16 and 19 are finely cut by pressurizing and heating, so as to retain the stretchability in the waist stretch zone A2 and eliminate the stretchability in the non-stretch zone A1.

The sheet material forming the inner sheet layer 12H and the outer sheet layer 12S is not particularly limited, but nonwoven fabrics can be preferably used. When nonwoven fabrics are used, the weight per unit area of each sheet is preferably 10 to 30 g/ ^m2 .

The elastic members 16 to 19 are fixed to the outer bodies 12F and 12B by hot melt adhesive HM applied by various coating methods. The inner sheet 12H and the outer sheet 12S are preferably joined in the portions having the elastic members 16 to 19 by hot melt adhesive HM for fixing the elastic members 16 to 19; in the portions not having the elastic members 16 to 19, they may be joined by hot melt adhesive HM, may be joined by means of raw material welding such as heat sealing or ultrasonic sealing, or may be partially or entirely bonded. In the portion of the outer body 12F, 12B in the illustrated example having the elastic members 16 to 19, a hot melt adhesive HM is applied only on the outer peripheral surface of the elastic members 16 to 19 by using a coating means such as a comb-type spray gun or a rubber band spray nozzle, and the elastic members 16 to 19 are sandwiched between the sheets, thereby fixing the elastic members 16 to 19 relative to the two sheets and fixing the two sheets with each other using only the hot melt adhesive HM applied on the outer peripheral surface of the elastic members 16 to 19. The elastic members 16 to 19 may also be fixed to the two sheets only at the two end portions in the stretching direction in the waist stretching area A2.

(Inner and outer joints) The inner body 200 can be joined to the outer body 12F, 12B by means of joining methods such as heat sealing or ultrasonic sealing based on the fusion of raw materials, or by hot melt adhesives. The inner and outer joints 201, 202 that join the inner body 200 and the outer body 12F, 12B together can be provided in almost the entire area where the inner body 200 and the outer body 12F, 12B overlap, as shown in FIG2 , for example, can be provided in the portion of the inner body 200 other than the two ends in the width direction.

In the illustrated example, the back surface of the inner body 200, that is, in this case, is fixed to the inner surface of the outer body 12B, 12B by a hot melt adhesive applied to the back surface of the liquid-impermeable sheet 11 and the root portion 65 of the standing gathers 60. Moreover, as shown in FIGS. 13 to 15, the back surfaces of the left and right side flaps 70 are joined to the portion overlapping with the rear outer body 12B by a hot melt adhesive HM. Thus, the left and right side flaps 70 have a rear joining region 70B joined to the portion including the lower end portion 14 of the rear outer body 12B.

(Hip coverage) In the present shorts-type disposable diaper, the rear joint area 70B of the side flap 70 is contracted in the width direction WD together with the waist extension area A2 of the rear outer body 12B in the natural length (before wearing). Here, if the tensile force when the lower end 14 of the front outer body 12F is contracted to 3/4 of its size in the width direction WD after stretching to the elastic limit is greater than the tensile force when the lower end 14 of the rear outer body 12B is contracted to 3/4 of its size in the width direction WD after stretching to the elastic limit, then as shown by the arrow mark in FIG. 17, the lower end 14 of the rear outer body 12B is more stretched (longer stretched) in the width direction WD than the lower end 14 of the front outer body 12F in the wearing state. As a result, the rear joint area 70B of the side flap 70 is expanded more widely in the width direction WD, and the side flap 70 covers the buttocks in a wider range, making it difficult for the inner body 200 to be caught in the buttocks seam.

In particular, as shown in the example shown in the figure, when the aforementioned hollow portion 70H is set to the rear joining area 70B, when worn, the rear joining area 70B is expanded more in the width direction WD, so as the bulge of the hollow portion 70H becomes closer to flatness as it moves toward the rear joining area 70B, thereby achieving a good fit on the buttocks.

The tensile force when the lower end 14 of the front outer body 12F and the lower end 14 of the rear outer body 12B are stretched to the elastic limit in the width direction WD and then contracted to 3/4 of their size can be measured separately by the following steps. (1) As shown in FIG. 18(a), the side seal 12A is peeled off, and the two side portions of the front outer body 12F and the two side portions of the rear outer body 12B are separated into an unfolded state, and then the lower end 14 of the front outer body 12F and the lower end 14 of the rear outer body 12B are cut, and the absorbent body 56 is removed as much as possible to prepare a test piece 14F of the lower end 14 of the front outer body 12F and a test piece 14B of the lower end 14 of the rear outer body 12B. In the test pieces 14F and 14B, a portion 200c other than the absorbent body 56 in the inner body 200 remains. (2) The widthwise dimension between the side seals 12A in the test piece 14F (not shown) of natural length is measured using a ruler (the shortest dimension when the widthwise dimension changes in the front-rear direction). In addition, for the test piece 14F at the lower end 14 of the front outer body 12F, the side seals 12A on one side are maintained parallel to the side seals 12A on the other side, while being stretched in the widthwise direction to the elastic limit (the expanded state in which the waistline expansion zone is not contracted or relaxed but is flatly expanded), and the widthwise dimension d2 of the side seals 12A at the elastic limit is measured using a ruler. In addition, the latter dimension d2 is the same in both the test piece 14F at the lower end 14 of the front exterior body 12F and the test piece 14B at the lower end 14 of the rear exterior body 12B, so only one side needs to be measured. (3) In a state where the chuck distance Dc is less than the dimension in the width direction between the side seals 12A in the test piece 14F of the natural length, the side seal 12A of one side of the test piece 14F at the lower end 14 of the front exterior body 12F is clamped by the chuck (clamp) C1 of one side of the tensile testing machine over the entire front-to-back direction LD, and the side seal 12A of the other side of the test piece 14F at the lower end 14 of the front exterior body 12F is clamped by the chuck (clamp) C2 of the other side of the tensile testing machine over the entire front-to-back direction LD. (4) As shown in FIG. 18(b), while maintaining the parallelism between the side seals 12A on one side and the side seals 12A on the other side, the clamp distance Dc is stretched to d2 (elastic limit) at a stretching speed of 300 mm/min, and then the clamp distance Dc is shortened. The tensile force when the test piece 14F is contracted when the clamp distance Dc becomes 3/4 of d2 is measured. This tensile force is set as the measured value of the tensile force when the lower end portion 14 of the front outer body 12F is contracted to 3/4 of its size in the width direction WD after being stretched to the elastic limit. (5) For the test piece 14B at the lower end 14 of the rear outer body 12B, the above steps (2) to (4) are performed in the same manner as for the front outer body 12F, and the tensile force is measured when the lower end 14 of the rear outer body 12B is stretched to the elastic limit in the width direction WD and then contracted to 3/4 of its size. (6) In addition, the distance Dc between the clamps is measured using a ruler.

In order to make the above-mentioned difference in tensile force, the number, thickness, spacing, type of raw material, arrangement in the front-rear direction LD, and maximum elongation of the elastic members 16 to 19 can be made different in the front outer body 12F and the rear outer body 12B. For example, in a general shorts-type disposable diaper, as shown in the example, the dimension of the width direction WD of the front outer body 12F is almost the same as the dimension of the width direction WD of the rear outer body 12B. The front outer body 12F and the rear outer body 12B can be contracted in the width direction WD by the elastic members 16 to 19 in the state of natural length, and can be extended in the width direction WD only by the contracted amount. In this case, the simplest method is to make the number, thickness, spacing, type of raw material, and arrangement of the elastic members 16 to 19 in the front outer body 12F and the rear outer body 12B the same, and only make the maximum elongation of the front outer body 12F larger than that of the rear outer body 12B, so that the above-mentioned difference in tensile force can be made. It is also possible to make the number of elastic members 16 to 19 larger in the front outer body 12F than in the rear outer body 12B, and make the other conditions common in the front outer body 12F and the rear outer body 12B, or to make the thickness of the elastic members thicker in the front outer body 12F than in the rear outer body 12B, and make the other conditions common in the front outer body 12F and the rear outer body 12B.

It is sufficient to appropriately determine the difference in tensile force between the lower end portion 14 of the front outer body 12F and the lower end portion 14 of the rear outer body 12B. Under normal circumstances, it is preferred that the tensile force at which the lower end portion 14 of the front outer body 12F contracts to 3/4 of its size after stretching to the elastic limit in the width direction WD is 1.3 to 3.0 times the tensile force at which the lower end portion 14 of the rear outer body 12B contracts to 3/4 of its size after stretching to the elastic limit in the width direction WD, and is particularly preferred to be 1.5 to 2.0 times.

The dimension of the width direction WD of the rear joint region 70B (in the expanded state) can be appropriately determined, but in order to ensure that the coverage range of the buttocks is as wide as possible, it is preferably 0.8 to 1 times the dimension of the width direction WD of the side flap 70 (in the expanded state). In addition, the dimension of the front-back direction LD of the rear joint region 70B (in the expanded state) is preferably greater than the dimension of the front-back direction LD of the overlapping region of the side flap 70 and the waistline stretching region A2 of the rear outer body 12B, and less than the dimension of the front-back direction LD of the overlapping region of the rear outer body 12B and the side flap 70.

In order to reduce the amount of raw materials used in the outer bodies 12F and 12B and to make a simple structure, the front outer body 12F and the rear outer body 12B are preferably rectangular with the same dimensions in the front-to-back direction LD and the same dimensions in the width direction WD. In this design, the appropriate dimensions in the front-to-back direction LD of the front outer body 12F and the rear outer body 12B are 0.2 to 0.4 times the total length Y of the product. At this time, although the coverage of the buttocks is reduced only in the rear outer body 12B, the coverage of the buttocks can be compensated by the side wings 70 of the inner body 200.

As in the case of the rear outer body 12B, as shown in FIG16, the back surfaces of the left and right side flaps 70 are preferably joined to the portion overlapping the front outer body 12F by hot melt adhesive HM, and the left and right side flaps 70 have a front joining area 70F joined to the portion including the lower end 14 of the front outer body 12F. At this time, the front joining area 70F of the side flap 70 shrinks in the width direction WD together with the waist stretching area A2 of the front outer body 12F in the state of natural length (before wearing). Here, as mentioned above, if the tensile force when the lower end portion 14 of the front outer body is stretched in the width direction WD and then contracted to 3/4 of its size is greater than the tensile force when the lower end portion 14 of the rear outer body is stretched in the width direction WD and then contracted to 3/4 of its size, then in the worn state, the lower end portion 14 of the rear outer body 12B is stretched to a greater extent (stretched longer) in the width direction WD than the lower end portion 14 of the front outer body 12F. As a result, as shown in FIG. 17 , although the front joining area 70F of the side flap 70 expands in the width direction WD, it does not expand more than the rear joining area 70B. Therefore, compared with the case where the front joining area 70F and the rear joining area 70B expand to the same extent, the side flap 70 can fit the groin more appropriately.

In particular, when the aforementioned hollow portion 70H is set to the front joining area 70F as shown in the example shown in the figure, the rear joining area 70B is expanded more in the width direction WD than the front joining area 70F when worn, so the width of the side wings 70 becomes narrower from the back to the front, and the bulge of the hollow portion 70H becomes larger from the back to the front, so that the fit for the groin becomes good.

The dimension of the width direction WD of the front joint region 70F is preferably the same as the dimension of the width direction WD of the rear joint region 70B, but may be shorter or longer. In addition, the dimension of the front joint region 70F in the front-back direction LD is preferably greater than the dimension of the front-back direction LD of the overlapping region between the side flap 70 and the waistline stretchable region A2 of the front outer body 12F, but less than the dimension of the front-back direction LD of the overlapping region between the front outer body 12F and the side flap 70.

(Nonwoven fabric) As the nonwoven fabric described above, known nonwoven fabrics can be used appropriately according to the location and purpose. As the constituent fibers of the nonwoven fabric, in addition to being able to select synthetic fibers such as olefins such as polyethylene and polypropylene, polyesters, and polyamides (including composite fibers such as core-sheath fibers in addition to single-component fibers), regenerated fibers such as rayon or cuprosan, and natural fibers such as cotton can be used without particular limitation, and these fibers can also be used in a mixed manner. In order to improve the softness of the nonwoven fabric, it is preferable to set the constituent fibers to curled fibers. Furthermore, the constituent fibers of the nonwoven fabric may be hydrophilic fibers (including fibers made hydrophilic by a hydrophilic agent), hydrophobic fibers, or water-repellent fibers (including fibers made water-repellent by a water-repellent agent). Furthermore, nonwoven fabrics are generally classified into short-fiber nonwoven fabrics, long-fiber nonwoven fabrics, spunbond nonwoven fabrics, meltblown nonwoven fabrics, spunlace nonwoven fabrics, thermal bond (hot air) nonwoven fabrics, needle-punched nonwoven fabrics, point-bonded nonwoven fabrics, laminated nonwoven fabrics (SMS nonwoven fabrics and SMMS nonwoven fabrics formed by sandwiching a meltblown layer between spunbond layers, etc.), etc., according to the fiber length, sheet forming method, fiber bonding method, and laminate structure, and any of these nonwoven fabrics can also be used.

＜Explanation of terms used in this manual＞ Unless otherwise specified in this manual, the following terms in this manual have the following meanings.

・The “front-rear direction” refers to the direction indicated by the symbol LD in the figure (longitudinal direction), and the “width direction” refers to the direction indicated by the symbol WD in the figure (left-right direction). The front-rear direction is orthogonal to the width direction.

・The "front side" refers to the side closer to the wearer's skin when the shorts-type disposable diaper is worn, and the "back side" refers to the side farther from the wearer's skin when the shorts-type disposable diaper is worn.

・“Front surface” refers to the side of the member that is closer to the wearer’s skin when the shorts-type disposable diaper is worn, and “back surface” refers to the side that is farther from the wearer’s skin when the shorts-type disposable diaper is worn.

・"Elongation" refers to the value when the natural length is set to 100%. For example, an elongation of 200% means that the elongation ratio is 2 times.

・The "maximum elongation" refers to the elongation when stretched to the elastic limit (in other words, the elongation in the expanded state where the stretchable area is not contracted or relaxed but stretched flat).

・"Gel strength" was measured as follows. 1.0 g of superabsorbent polymer was added to 49.0 g of artificial urine (a mixture of 2 wt% urea, 0.8 wt% sodium chloride, 0.03 wt% calcium chloride dihydrate, 0.08 wt% magnesium sulfate heptahydrate, and 97.09 wt% ion-exchanged water) and stirred with a stirrer. The generated gel was placed in a constant temperature and humidity chamber at 40°C × 60% RH for 3 hours and then returned to room temperature. The gel strength was measured using a curdmeter (Curdmeter-MAX ME-500 manufactured by I.techno Engineering).

・The "weight per unit area" is measured as follows. After pre-drying the sample or test piece, place it in a standard test room or device (temperature of the test site is 23±1℃, relative humidity is 50±2%) to make it a constant weight state. Pre-drying means that the sample or test piece is kept constant in an environment with a temperature of 100℃. In addition, for fibers with a legal moisture content of 0.0%, pre-drying is not required. Using a template for sample selection (100mm×100mm), cut a sample of 100mm×100mm size from the test piece in a constant weight state. Measure the weight of the sample and multiply it by 100 to calculate the weight per square meter as the weight per unit area.

・The thickness is measured automatically with an automatic thickness tester (KES-G5 portable compression measuring program) at a load of 0.098N/ ^cm2 and a pressurized area of ^2cm2 .

・"Water absorption" is measured according to JIS K7223-1996 "Test method for water absorption of highly water-absorbent resins".

・The water absorption rate is the "time to the end point" when using 2g of super absorbent polymer and 50g of physiological saline in accordance with JIS K 7224-1996 "Test method for water absorption rate of super absorbent resins".

・The "expanded state" means a state in which the device is flatly expanded without contraction or relaxation.

・The dimensions of each part are in the unfolded state, not the natural length, unless otherwise specified.

・In the absence of any description of the environmental conditions during the test or measurement, the test or measurement is carried out in a test room or device under standard conditions (test site at a temperature of 23±1℃ and a relative humidity of 50±2%).

[Industrial Applicability] The present invention can be used for the above-mentioned shorts-type disposable diapers.

11: Liquid-impermeable sheet 12A: Side seal 12B: Rear exterior body (exterior body) 12E: Waist extension 12F: Front exterior body (exterior body) 12H: Inner sheet layer 12S: Outer sheet layer 12d: Distance between the front and rear directions of the exterior body 12r: Inner cover layer 13: Cover nonwoven fabric 14: Lower end 14F, 14B: Test piece 15, 19: Elastic member below waist (elastic member) 16: Elastic member 17: Elastic member at waist (elastic member) 18: Elastic member 30: Top sheet 40: Middle sheet 50: Absorbent member 56: Absorber 56N: Gathering part 56X: Full width of absorber 58: Packing sheet 60: Rising pleats 60A: Front side part 60B: Root side part 62: Pleated sheet 63: Pleated elastic member 65: Root part 66: Main body part 67: Falling part 68: Rising part 70: Side flap 70F: Front joint area 70B: Back joint area 70H: Hollow part 71: First layer 72: Second layer 73: Side elastic member 74: Layer closest to the surface 75: Layer closest to the back 76: Inner layer 77: Non-joined part 79: Special sheet 200: Inner body 201,202: Inner and outer joints Y: Full length of diaper (full length of product) X: Full width of diaper WO: Waist opening LO: Leg opening LD: Front and back direction WD: Width direction A1: Non-stretching area A2: Waist stretch area F: front body B: back body L: middle area SG: side stretch area T: waist area U: lower waist area W: waist area C: hip cover area P1: first part P2: second part HM: hot melt adhesive d2: width dimension of the side seal within the elastic limit Dc: distance between clips D1, D2: clips (clamps) 200c: part of the inner body other than the absorbent body 2-2, 3-3, 4-4, 5-5: section line

FIG. 1 is a plan view showing the inner surface of a shorts-type disposable diaper in an unfolded state. FIG. 2 is a plan view showing the outer surface of a shorts-type disposable diaper in an unfolded state. FIG. 3 is a cross-sectional view along line 2-2 in FIG. 1. FIG. 4 is a cross-sectional view along line 3-3 in FIG. 1. FIG. 5(a) is a cross-sectional view along line 4-4 in FIG. 1, and FIG. 5(b) is a cross-sectional view along line 5-5 in FIG. 1. FIG. 6 is a perspective view of a shorts-type disposable diaper. FIG. 7 is a plan view showing the outer surface of an inner body in an unfolded state together with the outline of an outer body. FIG. 8 is a plan view showing the outer surface of an inner body in an unfolded state together with the outline of an outer body. FIG. 9 is a cross-sectional view of another example equivalent to the cross-sectional view along line 2-2 in FIG. 1. FIG. 10 is a cross-sectional view of another example of the cross-sectional view along the line 3-3 in FIG. 1 FIG. 11 is an enlarged cross-sectional view of an important part of FIG. FIG. 12 is an enlarged cross-sectional view of an important part of FIG. 9 FIG. 13 is an enlarged cross-sectional view of a portion having a rear joining area. FIG. 14 is an enlarged cross-sectional view of a portion having a front joining area. FIG. 15 is an enlarged plan view of a portion having a rear joining area. FIG. 16 is an enlarged plan view of a portion having a front joining area. FIG. 17 is a plan view schematically showing a wearing state. FIG. 18 is a front view schematically showing a tensile test method.

Domestic storage information (please note the storage institution, date, and number in order) None

Overseas storage information (please note the storage country, institution, date, and number in order) None

12A: Side seal

12B: Rear exterior body (exterior body)

12F: Front exterior body (exterior body)

30: Top piece

60: Stand up wrinkles

70: Side Wings

70B: rear junction area

200:Interior body

LO: Leg opening

Claims (4)

A shorts-type disposable diaper, characterized in that it comprises: a front outer body, which constitutes at least the waistline of the front body; a rear outer body, which constitutes at least the waistline of the rear body; an inner body including an absorbent body, which is arranged in a manner extending from the front outer body to the rear outer body; an inner-outer joint, which connects the inner body to the front outer body and the rear outer body respectively; and a side seal, which is formed by connecting the two side parts of the front outer body to the rear outer body. The two sides of the body are respectively joined together to form a waist opening and a pair of left and right leg openings; the front outer body and the rear outer body have a waist circumference stretching area that is elastically stretchable in the width direction, and the waist circumference stretching area includes the lower end portion of the portion that is defined as the side closest to the leg opening when the front-to-back direction range having the side sealing portion is divided into four equal parts in the front-to-back direction; on the two sides of the inner body, the side sealing portions that extend laterally further than the absorbent body The side wings extend from the front outer body to the rear outer body in the front-rear direction; the side wings have a side stretchable area that is elastically stretchable in the front-rear direction from the portion overlapping with the front outer body to the portion overlapping with the rear outer body; the waist stretchable area of the front outer body and the waist stretchable area of the rear outer body are provided with a portion that overlaps with at least the left and right side wings; the left and right side wings have a front joint area and a rear joint area The front joining area is joined to a portion including the lower end of the front outer body, and the rear joining area is joined to a portion including the lower end of the rear outer body; the width dimensions of the front joining area and the rear joining area are 0.8 to 1 times the width dimension of the side wing; the front joining area, together with the waistline stretching area of the front outer body, can be shrunk in the width direction and can be stretched in the width direction; The aforementioned rear joint area, together with the waistline stretching area of the aforementioned rear outer body, can be shrunk in the width direction and can be stretched in the width direction; the tensile force when the lower end portion of the aforementioned front outer body is stretched in the width direction to the elastic limit and then shrunk to 3/4 of its size is 1.3 to 3.0 times the tensile force when the lower end portion of the aforementioned rear outer body is stretched in the width direction to the elastic limit and then shrunk to 3/4 of its size; the aforementioned side stretching area, The side wing is a region in which a plurality of side elastic members are arranged at intervals along the front-rear direction; the side wing has two layers of folded sheet layers, which are folded back at the side edge of the side wing and extend to the back side of the side wing; the surface side portion of the folded sheet layer located outside and having the folded position as the boundary is connected to the folded sheet layer located inside. The side elastic member is fixed between the surface side portions with the bending position as the boundary; at least one of the sheet layer closest to the surface side of the side wing and the sheet layer closest to the back side of the side wing is not joined to the sheet layer adjacent to the back side thereof, thereby forming a first hollow portion in the side wing; and the surface side portion with the bending position as the boundary in the inner part of the folded back sheet layer is not joined to the member adjacent to the back side thereof, thereby forming a first hollow portion in the front part of the side wing. The side wing forms a second hollow portion; the second hollow portion extends from the side edge of the side wing to the central side closer to the width direction than the side elastic member located closest to the central side in the width direction, and continues from the front joint area to the rear joint area in the front-to-back direction; by contraction of the side elastic member, the portion of the side wing including the first hollow portion and the second hollow portion contracts in the front-to-back direction to form side wrinkles. The shorts type disposable diaper as claimed in claim 1, wherein the back side portion of the folded sheet layer located outside and the back side portion of the folded sheet layer located inside extend further to the central side in the width direction than the side elastic member located most laterally; between the side elastic member located most laterally and the side edge of the side flap, all the adjacent sheets in the thickness direction are not joined, thereby forming a hollow portion between each sheet layer. A shorts-type disposable diaper as described in claim 1 or 2, wherein the side flaps do not include the side elastic member in the portion from the side edge of the side flaps to the center side in the width direction to 5 mm. A shorts-type disposable diaper as described in claim 1 or 2, wherein the front outer body and the rear outer body are rectangular with the same dimensions in the front-to-back direction and the same dimensions in the width direction; the front-to-back dimensions of the front outer body and the rear outer body are 0.2 to 0.4 times the total length of the product.