Flat-leg pant-type disposable diaper and method of manufacturing the same

Abstract

Provides an easy-to-manufacture disposable diaper. The above problem is solved by a boxer shorts type disposable diaper having: an outer body (20) having a ventral outer body (20F), a back outer body (20B), and a crotch outer body (20C) extending between the ventral outer body (20F) and the back outer body (20B) through the wearer's crotch; and an inner body (10) joined to the inner side of at least the crotch outer body (20C) of the outer body (20), the inner body (10) including an absorbent body (13), the ventral outer body ( The crotch-side end of the central portion of the width direction of the outer part of the back outer part (20F) is joined with the crotch-side outer part (20C) to form a ventral joint (90F). The crotch-side end of the central portion of the width direction of the back outer part (20B) is joined with the crotch-side outer part (20C) to form a back joint (90B). The portion of the ventral outer part (20F) along the edge of the leg opening and the portion of the back outer part (20B) along the edge of the leg opening are telescopic in the width direction (WD). The portion of the crotch-side outer part (20C) along the edge of the leg opening is telescopic in the front-back direction (LD).

Description

Technical Field

[0001] This invention relates to a disposable diaper in the form of shorts and a method for manufacturing the same. Background Technology

[0002] Previously known types of disposable diapers can be broadly categorized into two types: belt type and panty type. Belt type disposable diapers are constructed as follows: the front and back sections are connected by straps located on the sides of the front or back section, forming a waistband that covers the wearer's waist, and simultaneously forming a waist opening and a pair of thigh openings.

[0003] On the other hand, the shorts-type disposable diaper is constructed as follows: the front and back parts are pre-joined together by heat fusion or other means to form the main body of the shorts, without the need for assembly as with belt-type disposable diapers.

[0004] As a type of disposable diaper in shorts, there are the following types: triangle shorts, which have a V-shaped edge that wraps around the leg root from the lower side of the crotch to the armpit side of the waist; and boxer shorts, which have a thigh circumference that covers the area around the thigh.

[0005] The aforementioned boxer shorts-style disposable diapers, with their thigh-length cuffs, offer the advantage of preventing leakage from the leg openings. Furthermore, in recent years, with the diversification of design preferences, the demand for boxer shorts-style disposable diapers has increased. In particular, there is a significant number of consumers who, while normally preferring boxer shorts underwear, are experiencing increased incontinence as they age (over 60) and are therefore considering disposable diapers. These consumers also seek the same comfort and appearance as boxer shorts underwear, making these diapers highly appealing.

[0006] As disposable diapers in the shape of boxer shorts, the following patent documents 1 to 4 are existing art documents.

[0007] Patent Document 1 discloses a disposable diaper having: a waist opening; a pair of leg openings; and a lower extending leg portion that extends downward along the wearer's leg to form the leg openings when worn. The disposable diaper also has: at least a pair of leak-proof walls that extend longitudinally and each has a free end and a fixed end, as well as a free end portion containing the corresponding free end; and a pair of leg pieces located on the outer side of each leak-proof wall in the transverse direction and having elongation. Each leak-proof wall has a free end elastic member that is an elongated elastic member that is installed on the free end portion of the leak-proof wall in the free direction. The inner side edge of each leg piece in the transverse direction is joined between the free end and the fixed end of the leak-proof wall, and each leg piece is in a non-elongated state when joined. By adopting such a structure, the following effect is disclosed: when the wearer wants to wear the diaper, the leg opening faces the direction for the wearer's legs to pass through, and the leg opening is not narrow. Therefore, when the wearer's legs pass through the leg opening, the legs are not easily stuck at the edge of the leg opening, and the legs can pass through easily.

[0008] Patent Document 2 discloses a boxer shorts-type disposable diaper comprising: an outer body having a front portion, a back portion, a crotch portion, and a pair of left and right leg covering portions, the left and right leg covering portions having a pair of left and right leg openings on the outer side of the crotch portion in the width direction; and an absorbent body disposed inside the crotch portion of the outer body, wherein an inner leg component is provided in the inner leg region of each pair of left and right leg covering portions, the circumferential length of the end of the inner leg component located on the side of the leg opening is longer than the circumferential length of the end located on the opposite side. The disclosed effect is that the inner leg component absorbs bodily fluid leaking from the crotch along the inner leg, prevents bodily fluid from leaking into the leg openings, and prevents elastic leg components such as rubber threads from directly contacting the skin.

[0009] In the disposable diaper of the shorts type disclosed in Patent Document 3, the front and back portions are connected at the side portions and crotch area to form a waist opening and a pair of leg openings. Each part of the front and back portions is recessed at approximately the center of the opposite side edge of the waist opening edge, and the distance from the bottom of the recess to the waist opening edge is shorter than the length of the side edge. The side edges of each part of the front and back portions are connected to each other, and the recessed edges are connected to each other. The lower part of the side edge joint and the recessed edge joint form a crotch tube with leg openings at the end. This diaper structure, due to the leg tube, allows it to fit snugly around the legs. Furthermore, since the leg openings are separate from the crotch area, leakage prevention is improved. In addition, it has a design very similar to briefs.

[0010] In the boxer brief type disposable diaper disclosed in Patent Document 4, the inner body has an elastic band that passes through the inner leg contact portion and extends continuously in the front-to-back direction from a position intersecting with the front leg elastic member to a position intersecting with the rear leg elastic member. At least the portion of the elastic band from the position intersecting with the front leg elastic member to the position intersecting with the rear leg elastic member is an elastic region in which an elongated relay elastic member is continuously mounted in the front-to-back direction. At least the elastic region of the elastic band engages with the outer body. By adopting this structure, the following effects are disclosed: it can prevent the inner leg contact portion from shrinking in the width direction, preventing a deterioration in wearing comfort and the formation of gaps.

[0011] Existing technical documents

[0012] Patent documents

[0013] Patent Document 1: Japanese Patent No. 5717660

[0014] Patent Document 2: Japanese Patent No. 6323379

[0015] Patent Document 3: Japanese Patent No. 4912199

[0016] Patent Document 4: Japanese Patent No. 6752696 Summary of the Invention

[0017] The problem that the invention aims to solve

[0018] The disposable diapers disclosed in Patent Documents 1 to 4 have elastic members arranged along the legs. To manufacture such diapers, for example, a continuous linear elastic member is fed between multiple sheets constituting the outer body and sandwiched and bonded, but when the elastic member is fed in, it is arranged along the leg circumference by swinging the elastic member.

[0019] However, since the multiple sheets constituting the outer body move at high speed during manufacturing, it is not easy (in particular, alignment is not easy) to arrange the elastic component along the leg opening of the diaper in accordance with the movement of such sheets. That is, from the point of view on the arrangement of the elastic component, the disposable diapers disclosed in Patent Documents 1 to 4 have the problem of manufacturing difficulties.

[0020] Therefore, the main objective of this invention is to provide a disposable diaper that is easy to manufacture.

[0021] Methods for solving problems

[0022] A representative embodiment of the present invention that solves the above-mentioned problems is as follows.

[0023] <Method 1>

[0024] A disposable diaper in the form of boxer shorts, characterized in that it comprises: an outer body having a ventral outer body, a back outer body, and a crotch outer body, the crotch outer body extending between the ventral and back outer bodies in a manner passing through the wearer's crotch; and an inner body joined to the inner side of at least the crotch outer body of the outer body, the inner body comprising an absorbent core, the side edges of the ventral outer body joining the side edges of the back outer body to form a waist opening and a pair of leg openings, the crotch outer body having a pair of inner leg contact portions, the pair of inner leg contact portions being wider than the absorbent core. Extending to one side and the other side in the angular direction, the portion along the edge of the leg opening, including the inner leg contact portion, forms a pair of leg tube portions surrounding the leg root side. The crotch-side end of the central portion of the abdominal outer garment in the width direction joins with the crotch-side outer garment to form an abdominal joint portion. The crotch-side end of the central portion of the back outer garment in the width direction joins with the crotch-side outer garment to form a back joint portion. The portion of the abdominal outer garment along the edge of the leg opening and the portion of the back outer garment along the edge of the leg opening are extendable in the width direction. The portion of the crotch-side outer garment along the edge of the leg opening is extendable in the front-back direction.

[0025] (Effects)

[0026] The outline of this diaper is that the abdominal and back outer garments, which extend in the width direction, are joined to the crotch outer garment, which extends in the front-to-back direction, on the abdominal and back sides respectively. The leg circumference outer garment constituting the diaper is divided into three parts: the abdominal outer garment, the back outer garment, and the crotch outer garment. Based on this, the extension direction of the abdominal and back outer garments is set to the width direction, and the extension direction of the crotch outer garment is set to the front-to-back direction. Each outer garment is joined together. By adopting the above structure, the diaper does not need to be configured with elastic members while swinging along the leg circumference, as in the aforementioned patent documents 1 to 4, thus making manufacturing easier.

[0027] <Method 2>

[0028] According to the first method of the disposable diaper in the shape of shorts, the ventral joint has an inclined portion that extends ventrally from the left and right sides in the width direction toward the central side.

[0029] (Effects)

[0030] When the abdominal joint is inclined in a manner that extends from the left and right sides toward the center in the width direction toward the abdominal side, the stretching direction of the abdominal outer garment and the stretching direction of the crotch outer garment are neatly connected in a line at this joint, thus improving the fit of the leg circumference.

[0031] <Third Method>

[0032] According to the first or second method of the flat-leg shorts type disposable diaper, the back-side joint has an inclined portion that extends towards the back side from the left and right sides in the width direction toward the central side.

[0033] (Effects)

[0034] Similar to the second method, when the back side joint is inclined in a way that extends towards the back side from the left and right sides in the width direction toward the center side, the stretching direction of the back side outer garment and the stretching direction of the crotch part outer garment are neatly connected in a line at this joint, thus improving the fit of the leg circumference.

[0035] <Method 4>

[0036] According to the first embodiment of the disposable diaper in the shape of shorts, the ventral joint has: a left-side inclined portion extending ventrally from the left side towards the center in the width direction; a right-side inclined portion extending ventrally from the right side towards the center in the width direction; and a connecting portion connecting the left-side inclined portion and the right-side inclined portion, wherein the ventralmost point of the connecting portion of the ventral joint is designated as the ventral connecting point. The dorsal joint has: a left-side inclined portion extending ventrally from the left side towards the center in the width direction; a right-side inclined portion extending ventrally from the right side towards the center in the width direction; and a connecting portion connecting the left-side inclined portion and the right-side inclined portion, wherein the dorsalmost point of the connecting portion of the dorsal joint is designated as the dorsal connecting point. The distance in the front-back direction from the point closest to the crotch side of the dorsal joint to the dorsal connecting point is shorter than the distance in the front-back direction from the point closest to the crotch side of the ventral joint to the ventral connecting point.

[0037] (Effects)

[0038] Because the rigidity of the ventral and dorsal joints is higher than that of their surrounding portions, there is a tendency for the diaper to bend gently at these joints during wear. Furthermore, as in this embodiment, by making the distance in the front-to-back direction from the point closest to the crotch of the dorsal joint to the dorsal connection point shorter than the distance in the front-to-back direction from the point closest to the crotch of the ventral joint to the ventral connection point, the area of ​​the dorsal outer garment that covers the dorsal portion during wear can be increased. As a result, the dorsal outer garment can be easily used to cover the buttocks, improving the comfort of wearing the diaper.

[0039] <Fifth Method>

[0040] According to the first method of the disposable diaper in the shape of shorts, the left and right portions of the crotch outer body are retractable in the front-back direction, while the central portion in the width direction is not retractable, and the absorbent body is engaged with the central portion in the width direction of the crotch outer body.

[0041] (Effects)

[0042] A structure is adopted that prevents the central portion of the crotch area outer cover, which connects to the absorbent core, from stretching. This structure prevents the absorbent core from stretching due to the outer cover's movement, thus preventing a deterioration in the diaper's comfort and absorbency.

[0043] On the other hand, a structure is adopted in which the left and right portions of the crotch area outer garment extend and retract in the front-to-back direction. Since the left and right portions of the crotch area outer garment are the parts that fit snugly against the inner thigh, the fit of the leg circumference can be improved by extending and retracting these portions in the front-to-back direction.

[0044] <Method 6>

[0045] A method for manufacturing a boxer shorts-type disposable diaper, which is the method for manufacturing a boxer shorts-type disposable diaper according to the first embodiment, is characterized in that the method for manufacturing a boxer shorts-type disposable diaper includes the following steps: an integrated outer body forming step, wherein a separately manufactured crotch portion outer body that extends in the front-back direction is sequentially joined at the crotch portion end of the portion of the abdominal outer body that extends in the width direction and the crotch portion end of the portion of the back outer body that extends in the width direction, to form an integrated outer body that extends in the front-back direction and the crotch portion. The process includes: an integrated outer casing that integrates the middle outer casing and the back outer casing; an inner casing installation process in which an additionally manufactured inner casing in an unfolded state is sequentially joined to the integrated outer casing to form an inner casing assembly; a folding process in which the inner casing assembly is folded in the CD direction to form a folded strip; and a side joining and cutting process in which the abdominal outer casing and the back outer casing are joined at the portions of the folded strip that become the two sides of each diaper, and the abdominal outer casing and the back outer casing are cut at the boundary of each diaper to obtain each diaper.

[0046] (Effects)

[0047] To provide elasticity along the leg circumference of the disposable diaper, a separately manufactured crotch-section outer garment that extends in the front-back direction is sequentially joined at the crotch-side ends of the portion spanning the abdominal outer garment that extends in the width direction and the portion forming the back outer garment that extends in the width direction, thus forming an integrated outer garment that integrates the abdominal outer garment, the crotch-section outer garment, and the back outer garment. By adopting this structure, it is not necessary to arrange the elastic member while allowing it to swing along the leg circumference, as in Patent Documents 1-4, making manufacturing easier.

[0048] <The 7th Method>

[0049] According to the manufacturing method of the flat-leg shorts type disposable diaper according to the sixth method, in the integrated outer body forming process, when the crotch side end of the part that will become the abdominal outer body is joined with the crotch part outer body to form an abdominal joint, the joint is joined obliquely as it extends from the left and right sides in the width direction toward the central side toward the abdominal side.

[0050] (Effects)

[0051] It achieves the same effect as the second method described above.

[0052] <The 8th Method>

[0053] According to the manufacturing method of the flat-leg shorts type disposable diaper according to the sixth or seventh method, in the integrated outer body forming process, when the crotch side end of the part that will become the back outer body is joined with the crotch part outer body to form the abdominal joint, the joint is joined obliquely as it extends from the left and right sides in the width direction toward the central side toward the back side.

[0054] (Effects)

[0055] Try to achieve the same effect as the third method described above.

[0056] Invention Effects

[0057] As described above, the present invention provides a disposable diaper that is easy to manufacture. Attached Figure Description

[0058] Figure 1 This is a top view (inner surface side) of a flat-legged disposable diaper in its unfolded state.

[0059] Figure 2 This is a top view (outer surface side) of a flat-legged disposable diaper in its unfolded state.

[0060] Figure 3 It is along Figure 1 A cross-sectional view along the XX line.

[0061] Figure 4 It is along Figure 1 A cross-sectional view of the YY line.

[0062] Figure 5 This is the front view of the product from the ventral side.

[0063] Figure 6 This is the front view of the abdomen when the garment is worn.

[0064] Figure 7 This is an observation of the clothing from a slightly lower front angle. Figure 1 A 3D image of a disposable diaper in the shape of shorts.

[0065] Figure 8 It is shown in magnification Figure 1 The diagram of the crotch absorbent body is a diagram in which the inner body is omitted.

[0066] Figure 9 This is a schematic diagram of the manufacturing method of the flat-leg shorts type disposable diaper of the present invention.

[0067] Figure 10 This is a top view (inner surface side) of a flat-leg shorts-type disposable diaper in its unfolded state, according to another embodiment.

[0068] Figure 11 This is an observation of the clothing from a slightly lower front angle. Figure 10 A 3D image of a disposable diaper in the shape of shorts.

[0069] Figure 12 This is a top view (inner surface side) of the flat-leg shorts type disposable diaper in the unfolded state of Comparative Example 1.

[0070] Figure 13 This is an observation of the clothing from a slightly lower front angle. Figure 12 A 3D diagram (illustrative image) of a disposable diaper in the shape of shorts.

[0071] Figure 14 This is a top view (inner surface side) of the flat-leg shorts type disposable diaper in the unfolded state of Comparative Example 2.

[0072] Figure 15 This is an observation of the clothing from a slightly lower front angle. Figure 14 A 3D diagram (illustrative image) of a disposable diaper in the shape of shorts. Detailed Implementation

[0073] Hereinafter, an embodiment of the present invention will be described in detail with reference to the accompanying drawings.

[0074] Figures 1 to 7A boxer shorts type disposable diaper 1 is shown. The boxer shorts type disposable diaper 1 (hereinafter also simply referred to as "diaper 1") has: an outer body 20 having a waist opening WO and a pair of leg openings LO, the outer body 20 extending from the edge of the waist opening on the ventral side FS to the edge of the waist opening on the dorsal side B; an inner body 10 disposed at least in the crotch portion C of the outer body 20, the inner body 10 including an absorbent body 13; and a side seal 21 that joins the two front sides and the two rear sides of the outer body 20.

[0075] Furthermore, the crotch portion outer body 20C disposed in the crotch portion C has a pair of inner leg contact portions 31 extending in the width direction relative to the absorber 13 (specifically referring to the outer rectangle of the absorber 13. The outer rectangle is an imaginary rectangle that is circumscribed to the absorber 13 when viewed from above in the unfolded state. In this embodiment, one opposite side of the outer rectangle of the absorber 13 is approximately the same as the two side edges of the inner body 10). The portion including the inner leg contact portions 31 and along the edge 29 of the leg opening forms a pair of leg tube portions 30 surrounding the leg root side.

[0076] During manufacturing, the inner body 10 and the outer body 20 are joined by a joining method such as hot melt adhesive. Then, the inner body 10 and the outer body 20 are folded at the center of the front part F and the back part B in the front-to-back direction (longitudinal direction). The two sides of the front part F and the back part B are joined together by hot melt welding or hot melt adhesive to form the side sealing part 21, thereby forming a flat-angle shorts type disposable diaper 1 with a waist opening WO and a pair of leg openings LO.

[0077] (Example of internal structure)

[0078] like Figure 3 , Figure 4 As shown, the inner body 10 has a structure in which the absorbent 13 is positioned between a liquid-permeable top sheet 11 made of non-woven fabric or the like and a liquid-impermeable sheet 12 made of polyethylene or the like, thereby absorbing and retaining excrement that has permeated through the top sheet 11. The planar shape of the inner body 10 is not particularly limited, but it is generally similar to... Figure 1 Set it to be roughly rectangular as shown in the figure.

[0079] (Top slide 11)

[0080] The top sheet 11, which covers the front side of the absorbent 13 and forms the skin-contacting surface, is preferably made of porous or non-porous nonwoven fabric, porous plastic sheet, etc. The fibers constituting the nonwoven fabric can be synthetic fibers such as olefin-based fibers (e.g., polyethylene or polypropylene), polyester-based fibers, polyamide-based fibers, regenerated fibers such as rayon or cuprammonium fiber, or natural fibers such as cotton. Nonwoven fabrics obtained through appropriate processing methods such as hydroentangling, spunbonding, thermal bonding, meltblowing, and needle punching can be used. Among these processing methods, hydroentangling is superior in terms of softness and drape, while thermal bonding is superior in terms of fluffiness and softness. When multiple pores are formed on the top sheet 11, urine and the like are quickly absorbed, resulting in excellent dryness. In the illustrated embodiment, the top sheet 11 wraps around the side edge of the absorbent 13 and extends to the back side of the absorbent 13, but this is not a limitation.

[0081] (Impermeable sheet 12)

[0082] The liquid-impermeable sheet 12 covering the back side of the absorbent 13 can be a liquid-impermeable plastic sheet such as polyethylene or polypropylene, but in recent years, from the viewpoint of preventing stuffiness, a liquid-impermeable sheet with moisture permeability is preferred. As such a water-blocking and moisture-permeable sheet, a microporous sheet can be cited as an example. This microporous sheet is formed by melt-blending an inorganic filler material in an olefin-based resin such as polyethylene or polypropylene, and then stretching the sheet in a uniaxial or biaxial direction.

[0083] As for the liquid-impermeable sheet 12, an opaque liquid-impermeable sheet is preferred to avoid brown discoloration from feces or urine. As for the opaque liquid-impermeable sheet, a sheet obtained by adding pigments or fillers such as calcium carbonate, titanium dioxide, zinc oxide, silica, clay, talc, and barium sulfate to plastic and then thinning it is preferred. In the illustrated embodiment, the liquid-impermeable sheet 12 and the top sheet 11 are folded back towards the back side on both sides in the width direction of the absorbent body 13, but this is not a limitation.

[0084] (Absorber 13)

[0085] As the absorbent 13, known absorbents can be used, such as those based on pulp fiber composites, aggregates of cellulose acetate filaments, or nonwoven fabrics, which are mixed with and fixed with highly absorbent polymers as needed. To maintain the shape and polymer, the absorbent 13 can be wrapped with a packaging sheet 14, such as crepe paper, which has liquid permeability and liquid retention properties, as needed. Furthermore, the absorbent 13 and the packaging sheet 14 are collectively referred to as absorbent member 49.

[0086] The absorbent body 13 is generally hourglass-shaped, having a narrower portion in the front-to-back direction, including the crotch portion C, whose width is narrower than the width of the front and back sides of the crotch portion C. However, it can also be any suitable shape, such as a rectangle. The size of the narrower portion can be appropriately determined, but the front-to-back length of the narrower portion can be approximately 20% to 50% of the total length of the diaper, and the width of the narrowest part of the narrower portion can be approximately 40% to 60% of the total width of the absorbent body 13. In the case of having such a narrower portion, if the planar shape of the inner body 10 is approximately rectangular, then a remaining portion without the absorbent body 13 is formed in the portion of the inner body 10 corresponding to the narrower portion of the absorbent body 13.

[0087] (3D Pleats BG)

[0088] Three-dimensional pleats (BG) that conform to the thigh area are formed on both sides of the inner body 10. For example... Figure 4 As shown, regarding this three-dimensional pleated BG, the fixed part, the main body, the folded part, and the free part are formed by pleated pieces 22 that are double-layered by folding back. The fixed part is fixed to the side of the back of the inner body 10. The main body extends from the fixed part, through the side of the inner body 10, to the side of the front of the inner body 10. The folded part is formed by fixing the front and rear ends of the main body to the side of the front of the inner body 10 in a folded state. The free part is formed by not fixing the folded parts together. Water-repellent nonwoven fabric is preferably used as the pleated piece 22.

[0089] Furthermore, between the double-layered pleated panels 22, elongated pleated elastic members 16 are disposed at the ends of the free portions, etc. The pleated elastic members 16 are used to maintain a shape similar to... Figure 4 As shown by the double-dotted line, the free part is raised by the elastic stretching force to form a three-dimensional pleat BG.

[0090] The pleated elastic component 16 can be made of commonly used materials such as styrene-based rubber, olefin-based rubber, polyurethane-based rubber, ester-based rubber, polyurethane, polyethylene, polystyrene, styrene-butadiene, silicone, and polyester. Furthermore, to prevent it from being easily observed from the outside, it can be configured with a thickness of 925 dtex or less, a tension of 150% to 350%, and a spacing of 10.0 mm or less. In addition to the linear shape shown in the illustration, a strip-shaped pleated elastic component with a certain width can also be used as the pleated elastic component 16.

[0091] The nonwoven fabric used for the pleats 22 is not particularly limited. In addition to synthetic fibers such as polyethylene or polypropylene, polyester, and polyamide, it can also be made of regenerated fibers such as rayon or cuprammonium cellulose, or natural fibers such as cotton. Furthermore, it can be manufactured using appropriate processing methods such as spunbonding, thermal bonding, meltblowing, and needle punching. In particular, to prevent urine from seeping through, it is preferable to use a nonwoven fabric coated with a water-repellent agent such as a silicone-based, paraffin-metal-based, or alkyl chromium chloride-based agent.

[0092] (Example of the construction of the outer casing 20)

[0093] In addition to the outer body 20, Figure 3 , Figure 4 Besides being formed by stacking multiple sheets as shown, it can also be formed by folding back a single sheet. The illustrated outer casing 20 has a three-layer structure consisting of a pressing sheet 7, a back sheet 9, and a stretch sheet 8. The pressing sheet 7 and back sheet 9 are made of non-woven fabric or the like, and the stretch sheet 8 is sandwiched between the pressing sheet 7 and back sheet 9, providing stretchability to the outer casing 20. However, the stacking structure of the outer casing 20 is not limited to this method. For example, it can also be a two-layer structure with the stretch sheet 8 and back sheet 9 without the pressing sheet 7, or a two-layer structure with the pressing sheet 7 and stretch sheet 8 without the back sheet 9. Furthermore, it can also be a one-layer structure with only the stretch sheet 8 without the pressing sheet 7 and back sheet 9, or a structure with four or more layers by adding additional sheets to the pressing sheet 7, stretch sheet 8, and back sheet 9.

[0094] Additionally, the stretchable piece 8 applies a stretching force WD in the width direction to the front part F and the back part B respectively, and a stretching force LD in the front-to-back direction to the crotch part C, so that the diaper 1 fits snugly against the body. Furthermore, the boundary between the waist elastic member 24 and the stretchable piece 8 does not need to be clearly defined. For example, the waist elastic member 24 and the stretchable piece 8 can overlap.

[0095] The stretch sheet 8 is not particularly limited; it can be an elastic (elastomer) film made of thermoplastic resin that is elastic in itself, or it can be a stretch nonwoven fabric. Using a stretch nonwoven fabric reduces the likelihood of wrinkles forming on the diaper surface. As a result, it can closely resemble the appearance of underwear and prevents undesirable situations such as diaper wrinkles appearing on outer garments such as pants. Furthermore, in addition to using a non-porous stretch sheet, a stretch sheet with multiple holes or slits for ventilation can also be used as the stretch sheet 8. An elastic sheet with the following tensile strength is particularly preferred: 8N to 25N / 35mm in the width direction WD (stretch directions ED, MD), 5N to 20N / 35mm in the front-to-back direction LD (directions perpendicular to the stretch directions XD, CD), a tensile elongation of 450% to 1050% in the width direction WD, and a tensile elongation of 450% to 1400% in the front-to-back direction LD. The thickness of the stretch sheet 8 is not particularly limited, but is preferably about 20μm to 40μm. Alternatively, the stretch sheet 8 can be a two-layer or multi-layer nonwoven fabric sheet. Regarding this nonwoven fabric sheet, an elongated elastic stretching member is sandwiched between any of the sheets constituting the nonwoven fabric sheet, allowing the entire nonwoven fabric sheet to stretch and contract through the stretching action of this elongated elastic stretching member. Furthermore, when using the stretch sheet 8 with the elongated elastic stretching member, to prevent folds or the like from protruding outwards during contraction, it is preferable to provide a fold-back portion or the like at a position further outwards than the stretch sheet 8.

[0096] Alternatively, to provide stretchability to the outer casing 20, the stretching sheet 8 may be omitted, and instead, elastic components may be provided. For example, various elastic components for providing stretchability to the outer casing 20 may be provided. In this case, multiple layers may be provided at least in the areas where elastic components are provided, with elastic components sandwiched between these layers. These multiple layers may be formed from a single sheet material, or they may be formed by folding back a single sheet material. As a specific example, the outer casing 20 may be formed as a two-layer structure consisting of a pressing sheet 7 and a back sheet 9, which are each made of non-woven fabric, etc. Various elastic components 24, etc., may be provided between the pressing sheet 7 and the back sheet 9, and between the non-woven fabric of the folded portion 20D obtained by folding the back sheet 9 back towards the inner surface at the waist opening edge, to provide stretchability.

[0097] The outer garment 20 may be composed, for example, of a ventral outer garment 20F disposed on the ventral side FS in the front-rear direction LD, a dorsal outer garment 20B disposed on the dorsal side BS in the front-rear direction LD, and a crotch outer garment 20C disposed in the crotch portion C between the ventral outer garment 20F and the dorsal outer garment 20B. The length of the crotch outer garment 20C in the width direction WD is shorter than the length of the ventral outer garment 20F and the dorsal outer garment 20B in the width direction WD, resulting in an outer garment 20 having a shape that narrows in the middle portion in the front-rear direction LD. In addition, the dorsal edge of the ventral outer garment 20F in the front-rear direction LD, the ventral edge of the dorsal outer garment 20B in the front-rear direction LD, and the two side edges of the crotch outer garment 20C respectively become the edge portions 29 of the leg opening.

[0098] (Segmented structure of outer casing 20)

[0099] The outer garment 20 is divided into a ventral outer garment 20F, a back outer garment 20B, and a crotch outer garment 20C. The crotch outer garment 20C extends between the ventral outer garment 20F and the back outer garment 20B, passing through the wearer's crotch. The crotch-side end of the central portion of the ventral outer garment 20F in the width direction joins with the crotch outer garment 20C to form a ventral joining portion 90F. Similarly, the crotch-side end of the central portion of the back outer garment 20B in the width direction joins with the crotch outer garment 20C to form a back joining portion 90B. Furthermore, the portion of the ventral outer garment 20F along the edge of the leg opening and the portion of the back outer garment 20B along the edge of the leg opening are extendable in the width direction WD, and the portion of the crotch outer garment 20C along the edge of the leg opening is extendable in the front-to-back direction LD. By dividing the leg opening outer body 20 constituting the diaper 1 into three parts—the abdominal outer body 20F, the back outer body 20B, and the crotch outer body 20C—and joining them to form a joint 90, and by making the stretching direction of the abdominal outer body 20F and the back outer body 20B the width direction WD, and the stretching direction of the crotch outer body 20C the front-back direction LD, it is not necessary to arrange the elastic member while it swings along the leg opening, as described in the aforementioned prior art documents, thus making manufacturing easier.

[0100] (Joint 90)

[0101] like Figure 8As shown, the ventral joint 90F in the joint 90 preferably extends obliquely toward the ventral FS from the left and right sides of the width direction WD toward the center. By having the ventral joint 90F have oblique portions 90FL and 90FR in this way, the stretching direction ECF of the ventral outer body 90F and the stretching direction ECC of the crotch outer body 90C are neatly connected in a line at the joint portions 90FL and 90FR, thereby improving the fit of the leg circumference.

[0102] Similarly, the back-side joining portion 90B in the joining portion 90 is preferably extended obliquely toward the back-side BS as it moves from the left and right sides of the width direction WD toward the center. By having the back-side joining portion 90B with oblique portions 90BL and 90BR in this way, the stretching direction ECB of the back-side outer garment 90B and the stretching direction ECC of the crotch outer garment 90C are neatly connected in a line at these joining portions 90BL and 90BR, thereby improving the fit of the leg circumference.

[0103] The tilt angles A1 to A4 of the abdominal joint 90F and the back joint 90B can be arbitrarily set, but are preferably about 5 degrees to 45 degrees, and more preferably about 10 degrees to 30 degrees. When the tilt angle is less than 5 degrees or greater than 45 degrees, the stretching directions of the leg circumference portion (crotch side portion) of the abdominal outer garment 20F, the leg circumference portion (crotch side portion) of the back outer garment 20B, and the leg circumference portion (both sides in the width direction WD) of the crotch outer garment 20C are difficult to connect neatly in a linear manner, which may lead to poor fit of the leg circumference portion.

[0104] Furthermore, the inclination angle A1 of the left side LS of the width direction WD of the ventral joint 90F refers to the angle (interior angle) between the ventral imaginary line FLF and the left inclination portion 90FL of the ventral joint 90F. This ventral imaginary line FLF is obtained by connecting the starting point 91FL of the left inclination portion 90FL of the ventral joint 90F and the starting point of the right inclination portion 90FR of the ventral joint 90F with a straight line. There is no particular problem when the left inclination portion 90FL of the ventral joint 90F is a straight line, but there are... Figure 8 In the case where the left-side inclined portion 90FL of the ventral joint 90F is curved, a tangent (called the imaginary tangent TL1) is drawn from the starting point 91FL of the left-side inclined portion 90FL of the ventral joint 90F. The angle between this imaginary tangent TL1 and the imaginary ventral line FLF is defined as the inclination angle A1. Similarly, as... Figure 8As shown, for the inclination angle A2 of the right side RS of the width direction WD of the ventral joint 90F, a tangent line (called imaginary tangent line TL2) is set from the starting point 91FR of the right side inclination portion 90FR of the ventral joint 90F. The angle (interior angle) between the imaginary tangent line TL2 and the ventral imaginary line FLF is defined as the inclination angle A2.

[0105] The same applies to the back-side joint 90B. Specifically, the tilt angle A3 of the left side LS in the width direction WD of the back-side joint 90B refers to the angle (interior angle) between the back-side imaginary line FLB and the left-side tilted portion 90BL of the back-side joint 90B. This back-side imaginary line FLB is obtained by connecting the starting point 91BL of the left-side tilted portion 90BL and the starting point of the right-side tilted portion 90BR of the back-side joint 90B with a straight line. (The last sentence appears to be incomplete and possibly refers to a different context.) Figure 8 When the inclined portion 90BL on the left side of the back-side joint 90B is curved, a tangent line (called the imaginary tangent line TL3) is drawn from the starting point 91BL of the inclined portion 90BL on the left side of the back-side joint 90B. The angle between this imaginary tangent line TL3 and the imaginary back-side line FLB is defined as the inclination angle A3. Similarly, for the inclination angle A4 of the right side RS of the width direction WD of the back-side joint 90B, as... Figure 8 As shown, a tangent (called imaginary tangent TL4) is set from the starting point 91BR of the inclined portion 90BR on the right side of the back joint 90B. The angle (interior angle) between the imaginary tangent TL4 and the imaginary back line FLB is defined as the inclination angle A4.

[0106] like Figure 8 As shown, the ventral joint 90F preferably has: a left inclined portion 90FL, which extends ventrally to the FS side from the left side LS of the width direction WD toward the center; a right inclined portion 90FR, which extends ventrally to the FS side from the right side RS of the width direction WD toward the center; and a connecting portion 90FT, which connects the left inclined portion 90FL to the right inclined portion 90FR. Similarly, the dorsal joint 90B preferably has: a left inclined portion 90BL, which extends dorsally to the BS side from the left side LS of the width direction WD toward the center; a right inclined portion 90BR, which extends dorsally to the BS side from the right side RS of the width direction WD toward the center; and a connecting portion 90BT, which connects the left inclined portion 90BL to the right inclined portion 90BR.

[0107] Furthermore, when the location of the most ventral FS in the connecting portion 90FT of the ventral joint 90F is assumed to be the ventral connection point 91FT, and the location of the most dorsal BS in the connecting portion 90BT of the dorsal joint 90B is assumed to be the dorsal connection point 91BT, it is preferable that the locations 91BL and 91BR (at the crotch side of the dorsal joint 90B) are located at... Figure 8 In this configuration, the distance BL from the dorsal junction 91BT to the dorsal junction 91BT in the anteroposterior direction LD is the same for 91BL and 91BR (where the positions of the frontal and posterior directions LD are the same). The distance BL is greater than the distance from the ventral junction 90F to the point closest to the crotch side, 91FL and 91FR (where the positions of the frontal and posterior directions LD are the Figure 8 In this configuration, the distance FL from the front-to-back LD of the 91FL and 91FR points to the front-to-back LD of the abdominal connection point 91FT is short. By adopting this structure, the area of ​​the back cover 20B covering the buttocks is increased when wearing the diaper, making it easier to cover the buttocks with the back cover 20B, thus improving the comfort of wearing the diaper. The distance BL from the point closest to the crotch side of the back joint 90B (where the front-to-back LD of points 91BL and 91BR are the same, this refers to points 91BL and 91BR; where the front-to-back LD of points 91BL and 91BR are different, this refers to the point closer to the crotch side of points 91BL and 91BR (91BL or 91BR). The same applies hereinafter.) to the front-to-back LD of the back connection point 91BT is preferably 5mm to 50mm, more preferably 10mm to 40mm. Furthermore, the distance FL from the point closest to the crotch side of the ventral joint 90F (where the positions of the front-rear direction LD of points 91FL and 91FR are the same, this refers to points 91FL and 91FR; where the positions of the front-rear direction LD of points 91FL and 91FR are different, this refers to the point closer to the crotch side of points 91FL and 91FR (91FL or 91FR). The same applies hereinafter.) to the front-rear direction LD of the ventral connection point 91FT is preferably 10mm to 60mm, more preferably 15mm to 50mm. Also, the difference between the distance BL from the point closest to the crotch side of the dorsal joint 90B to the front-rear direction LD of the dorsal connection point 91BT and the distance FL from the point closest to the crotch side of the ventral joint 90F to the front-rear direction LD of the ventral connection point 91FT is preferably 5mm to 30mm, more preferably 10mm to 20mm.

[0108] In addition, Figure 1 , Figure 8In this design, a connecting portion 90FT is provided at the abdominal joint 90F, but this connecting portion 90FT may be omitted. This is because, in many cases, the absorbent body 13 is joined to this connecting portion 90FT, and in many cases, the outer garment 20 with the absorbent body 13 joined is formed to be non-stretchable. Therefore, it is difficult to achieve the effect of neatly connecting the stretching direction ECF of the abdominal outer garment 90F and the stretching direction ECC of the crotch outer garment 90C in a linear manner, thereby improving the fit of the leg circumference. For the back joint 90B, for the same reason as the abdominal joint 90F, it is not necessary to provide a connecting portion 90BT.

[0109] like Figure 6 , Figure 7 As shown, the joint 90 is joined by means of heat fusion or the like, so in many cases the rigidity of the joint 90 is higher than that of the surrounding parts. Therefore, the diaper 1 becomes such that when the diaper 1 is worn, the outer body 20 bends at the joint 90, thus providing a sense of depth in the crotch area, similar to boxer briefs.

[0110] (Inner thigh contact area 31)

[0111] The crotch portion of the outer garment 20 has a pair of inner leg contact portions 31 extending in the width direction WD from both sides of the absorbent body 13 (particularly the outer rectangle of the absorbent body 13). The portion including these inner leg contact portions 31 and extending along the edge 29 of the leg opening forms a pair of leg tube portions 30 surrounding the leg root side. The width of the inner leg contact portions 31 (the length in the width direction WD from the side edge of the absorbent body 13 to the side edge of the crotch portion outer garment 20C) is preferably 10 mm to 80 mm, more preferably 20 mm to 60 mm. Furthermore, the width of these inner leg contact portions 31 is preferably 5% to 40% of the total width of the crotch portion outer garment 20C, more preferably 10% to 30%.

[0112] (The stretching and non-stretching of the crotch area outer garment 20C)

[0113] Preferably, the left and right portions of the crotch area outer garment 20C in the width direction WD are expandable and contractable in the front-to-back direction, while the central portion of the crotch area outer garment 20C in the width direction WD remains non-expandable. Furthermore, it is preferable that the absorbent body 13 is joined to the non-expandable portion of the crotch area outer garment 20C, i.e., the central portion in the width direction WD. By adopting this structure, the absorbent body 13 can be prevented from expanding and contracting due to the expansion and contraction of the crotch area outer garment 20C, thus preventing deterioration of the wearing comfort and absorbency of the diaper 1. Additionally, the left and right portions of the crotch area outer garment 20C in the width direction WD become portions that fit snugly against the inner thigh; therefore, by allowing these portions to expand and contract in the front-to-back direction LD, the fit around the leg circumference can be improved. Furthermore, the left and right portions of the crotch area outer garment 20C in the width direction WD correspond to the aforementioned inner thigh contact portion 31.

[0114] exist Figure 2 In this configuration, the entire area containing the absorbent body 13 in the crotch outer body 20C, the ventral outer body 20F, and the dorsal outer body 20B is designed to be non-stretchable (referred to as the non-stretchable area 19), with the remaining areas designated as stretchable areas. However, this configuration is not limited to this method. For example, a portion of the area containing the absorbent body 13 may be designated as the non-stretchable area 19, with the remaining areas designated as stretchable areas. Furthermore, it is possible to provide the non-stretchable area 19 not only in the area containing the absorbent body 13 but also in a portion of the area where the absorbent body is not present. For example, the entire area containing the inner body 10 may be designated as the non-stretchable area 19.

[0115] (The connection between the outer body 20 and the inner body 10)

[0116] exist Figure 2 In the middle, the portion where the inner body 10 and the outer body 20 are joined (inner body joint 18) is painted gray. Figure 2 In one manner, the entire back side of the inner body 10 is engaged with the outer body 20, but it is not limited to this manner; it is also possible to engage only a portion of the back side of the inner body 10 with the outer body 20.

[0117] (Waist elastic component 24)

[0118] The waist elastic member 24 is an elongated elastic member, such as multiple rubber threads, spaced apart in the front-to-back direction near the waist opening of the side sealing portion 21, which is formed by the front part F and the back part B. It is used to tighten the area near the waist opening of the diaper to make it fit snugly. In the illustrated example, the waist elastic member 24 uses multiple rubber threads, but a strap-like stretchable member can also be used instead. Furthermore, in the illustrated embodiment, the waist elastic member 24 is held between the non-woven fabric of the folded-back portion 20D of the back piece 9 at the waist, but it can also be held between the compression piece 7 and the back piece 9. The elongation rate of the elastic member 24 when fixed can be appropriately determined, but in the case of typical adult use, it can be approximately 160% to 320%.

[0119] (Press tablets 50 and 51 before and after)

[0120] like Figure 3 As shown, front and rear pressing tabs 50 and 51 can also be provided to cover the front and rear ends of the inner body 10 mounted on the inner surface of the outer body 20, and to prevent leakage from the front and rear edges of the inner body 10. To explain the illustrated arrangement in more detail, the front pressing tab 50 extends throughout the entire width direction from the inner surface of the folded portion 20D in the inner surface of the front body portion F to a position overlapping the front end of the inner body 10, and the rear pressing tab 51 extends throughout the entire width direction from the inner surface of the folded portion 20D in the inner surface of the rear body portion B to a position overlapping the rear end of the inner body 10. While installing the front and rear pressing tabs 50 and 51 separately as illustrated has the advantage of increased freedom in material selection, it also has disadvantages such as increased material and manufacturing processes. Therefore, the folded portion 20D can also be extended to the portion overlapping the inner body 10 to form a portion equivalent to the aforementioned pressing tabs 50 and 51.

[0121] (Manufacturing method)

[0122] exist Figure 9 An example of a method for manufacturing the flat-leg shorts type disposable diaper of the present invention is shown. Figure 9 (a) shows the main production line. Figure 9 (b) and (c) show the sub-production line, where MD represents Machine Direction (production line flow direction) and CD represents Crccss Machine Direction (perpendicular direction of production line flow direction).

[0123] Should Figure 9This diagram does not show all the steps involved in manufacturing a diaper. It primarily focuses on the assembly process of the inner body 10 and the outer body 20, as well as the steps preceding and following these steps. The diagram shows the gradual formation of the diaper from left to right. Furthermore, for ease of understanding, a method for manufacturing a diaper with rubber threads (elastic components) arranged on almost the entire surface of the outer body 20 (except for the portion where the inner body 10 is installed) is shown. However, the same method can also be used to manufacture diapers that do not use rubber threads on almost the entire surface of the outer body 20 but instead use stretch film or stretch nonwoven fabric.

[0124] In the main production line shown in Figure (a), the portion that becomes the ventral outer casing 20F and the portion that becomes the rear outer casing 20B flow along the MD direction with the width direction WD of the outer casings 20F and 20B aligned with the MD direction. In the secondary production line shown in Figure (b), the portion that becomes the crotch outer casing 20C flows along the MD direction with the front-to-back direction LD of the crotch outer casing 20C aligned with the MD direction. In the secondary production line shown in Figure (c), the portion that becomes the inner casing 10 flows along the MD direction with the front-to-back direction LD of the inner casing 10 aligned with the MD direction.

[0125] In the sub-production line of Figure (b), after the crotch outer body 20C is cut out one by one, the orientation of the crotch outer body 90C is rotated 90 degrees in the opposite direction. Similarly, in the sub-production line of Figure (c), after the inner body 10 is cut out one by one, the orientation of the inner body 10 is rotated 90 degrees in the opposite direction.

[0126] On the other hand, in the main production line shown in Figure (a), the crotch-side ends of the portion that will become the ventral outer garment 20F and the portion that will become the dorsal outer garment 20B are cut into arc shapes at the center side of the width direction WD. Then, the crotch-side outer garment 20C manufactured by the sub-production line shown in Figure (b) is placed on the cut portion, and the ventral outer garment 20F is joined to the crotch-side outer garment 20C along the edge of the cut arc-shaped portion, and the dorsal outer garment 20B is joined to the crotch-side outer garment 20C, forming an integrated outer garment 70 that integrates the outer garments 20F, 20C, and 20B (the arc-shaped joints are designated as the ventral joint 90F and the dorsal joint 90B) (this process of forming the integrated outer garment 70 is called the "integrated outer garment forming process"). Next, the inner body 10 manufactured by the sub-production line shown in Figure (c) is placed on the integrated outer body 70 and joined together to form an inner body assembly 71 (this process of forming the inner body assembly 71 is called the "inner body installation process"). Then, at the central portion CL in the front-rear direction LD of the inner body assembly 71, it is folded in the CD direction to form a folded strip 72 (this process of forming the folded strip 72 is called the "folding process"). Finally, the abdominal outer body 20F and the back outer body 20B are joined at the portions that become the two sides of each diaper (forming the side seal 21), and then the abdominal outer body 20F and the back outer body 20B are cut at the boundary of each diaper to obtain each diaper 1 (this process of joining the two sides and cutting at the boundary portion is called the "side joining and cutting process").

[0127] Furthermore, in the main production line shown in Figure (a), the process of cutting the crotch-side end of the portion that will become the ventral outer cover 20F and the portion that will become the dorsal outer cover 20B into an arc shape at the center side of the width direction WD can be omitted. In this case, when joining the ventral outer cover 20F to the crotch-side outer cover 20C and the dorsal outer cover 20B to the crotch-side outer cover 20C, the diaper 1 with an arc-shaped ventral joint 90F and a dorsal joint 90B can be formed by making the shape of the joints arc-shaped. By omitting the process of cutting the CT into an arc shape, it has the advantages of simplifying the manufacturing process, increasing manufacturing speed, and eliminating waste generated by cutting the CT.

[0128] In addition, the example above shows an example where the shape of the joint is arc-shaped, but it is not necessary to be arc-shaped. It can also be any shape, such as a straight line extending towards the central side in the width direction WD and the ventral side FS (or dorsal side BS) in the front-rear direction LD.

[0129] As described above, the diaper 1 is manufactured by joining the crotch outer body 20C with the stretching direction of the front-to-back direction LD and the abdominal outer body 20F and the back outer body 20B with the stretching direction of the width direction WD. Therefore, it is not necessary to arrange the elastic member while swinging along the leg circumference as in the patent documents 1 to 4, so manufacturing is easy.

[0130] (Before wearing, after wearing)

[0131] exist Figure 5 The image shows a boxer shorts-style disposable diaper 1 before wearing (product state). Figure 6 The image shows a disposable diaper 1 in the shape of shorts after being worn. Before wearing, the crotch area outer body 20C protrudes forward and backward in the LD crotch side CS. However, after wearing, the diaper 1 gains depth, and the crotch area outer body 20C abuts against the wearer's crotch. The crotch area outer body 20C extends from the abdomen to the back, so it becomes almost invisible when the diaper 1 is viewed from the front. Furthermore, the two sides of the crotch area outer body 20C in the width direction WD (mainly the inner thigh contact portion 31) are pressed downward by the wearer's feet to form a pair of thigh openings. Figure 6 In this way, the opening at the thigh circumference forms a one-tenth of the pant length. Of course, it's not limited to one-tenth of the pant length; it can also be two-tenths or longer.

[0132] (Other implementation methods)

[0133] exist Figure 1 , Figure 2 The example shows a diaper 1 with a waist area (excluding the area near the waist opening WO in the front part F and back part B) and a crotch area C made of a stretch membrane or stretch nonwoven fabric. By using such a stretch membrane or stretch nonwoven fabric, wrinkles are less likely to form on the surface of the diaper compared to cases using rubber threads, resulting in an appearance similar to boxer briefs. This can increase the purchasing intention of consumers who are looking for diapers with a similar appearance to underwear.

[0134] However, the present invention is not limited to this manner. For example, it can also be done as follows: Figure 10 As shown, elastic components 25, 26, and 27, such as rubber threads, are arranged around the waist and in the crotch area C. Generally, compared to stretch films and stretch nonwoven fabrics, the elastic components 25, 26, and 27 have a stronger tightening force; therefore, by using the elastic components 25, 26, and 27, the fit of the diaper can be improved compared to using stretch films and stretch nonwoven fabrics. Figure 10In the middle part of the front body part F and the rear body part B in the front-to-back direction LD (excluding the two ends of the front-to-back direction LD), a waist elastic member 25 is provided; a leg elastic member 26 is provided at the crotch side end of the front body part F and the rear body part B in the front-to-back direction LD; and a crotch elastic member 27 is provided in the crotch part C.

[0135] It can be seen that the leg circumference elastic component 26 and the crotch elastic component 27 intersect approximately at the inclined portion of the joint 90. At the joint 90, the stretching directions (stretching in the width direction WD) of the abdominal outer garment 90F and the back outer garment 90B are neatly connected in a line with the stretching direction (stretching in the front-to-back direction LD) of the crotch outer garment 90C. In this way, by connecting the stretching directions of the outer garments 20 in a line in a way that surrounds the wearer's legs, the fit of the leg circumference can be improved.

[0136] Similarly to the waist elastic member 24, the waist-circumference elastic member 25 and the leg-circumference elastic member 26 are elongated elastic members, such as multiple rubber threads spaced apart in the front-to-back direction LD. The crotch-area elastic member 27 is also an elongated elastic member, such as multiple rubber threads spaced apart in the width direction WD. While multiple rubber threads are used for the elastic members 25, 26, and 27 in the illustrated example, they can be replaced with, for example, strap-shaped stretchable members. Furthermore, the placement of these elastic members 25, 26, and 27 is not particularly limited; for example, they can be clamped between the compression plate 7 and the back plate 9. The elongation rate of the elastic members 25, 26, and 27 when fixed can be appropriately determined, but in the case of typical adult use, it can be approximately 160% to 320%.

[0137] Figure 11 It shows Figure 10 Another embodiment of the diaper 1 being worn. Figure 11 To improve visibility, the elastic member 25 around the waist (which actually exists) is omitted from the attached drawing. Instead, the elastic members 24 around the waist, 26 around the legs, and 27 around the crotch are shown. As can be seen from the drawing, the elastic members 26 around the legs and 27 around the crotch are neatly connected at the joint 90, thus surrounding the wearer's legs and resulting in improved leg fit.

[0138] exist Figure 12 , Figure 13 The image shows the wearing state of diaper 1 of Comparative Example 1. Additionally, in... Figure 13 In order to improve the visibility of the accompanying drawings, the elastic component 25 around the waist (which actually exists) is omitted, and the elastic components 24 around the waist, 26 around the legs and 27 around the crotch are shown.

[0139] In this comparative example 1, the ventral joint 90F and the dorsal joint 90B are formed as a straight line along the width direction WD. Figure 10 , Figure 11 In the embodiment, the ventral joint 90F is a shape that bulges out toward the ventral FS (protruding shape), and the dorsal joint 90B is a shape that bulges out toward the dorsal BS (protruding shape). However, in the embodiment of Comparative Example 1, there is no such bulging in the ventral joint 90F and the dorsal joint 90B.

[0140] When using the method of Comparative Example 1, according to Figure 13 The accompanying drawings also clearly show that the leg-circle elastic member 26 and the crotch elastic member 27 are not neatly connected at the joint 90 to surround the wearer's leg. Specifically, since the portion of the leg-circle elastic member 26 extending to the center side in the width direction WD extends into the inner body 10, the contraction force in the width direction WD becomes stronger, resulting in a state where it is pulled towards the width direction WD. As a result, it is difficult to improve the fit of the leg-circle.

[0141] exist Figure 14 , Figure 15 The image shows the wearing state of diaper 1 in Comparative Example 2. Additionally, in... Figure 14 In order to improve the visibility of the accompanying drawings, the elastic component 25 around the waist (which actually exists) is omitted, and the elastic components 24 around the waist, 26 around the legs and 27 around the crotch are shown.

[0142] In Comparative Example 2, the ventral joint 90F is bulging outwards towards the ventral FS (protruding shape), and the dorsal joint 90B is also bulging outwards towards the dorsal BS (protruding shape). However, this protruding shape is different from... Figure 1 They are different. Specifically, Figure 1 The ventral joint 90F and dorsal joint 90B of the aforementioned type have the aforementioned inclined portions, but the type in Comparative Example 2 does not have the inclined portions. That is, the aforementioned interior angles A1 to A4 are each 90 degrees.

[0143] When using the method of Comparative Example 2, according to Figure 15 The accompanying diagram also clearly shows that the leg-circle elastic member 26 and the crotch elastic member 27 are not neatly connected at the joint 90 to surround the wearer's leg. Specifically, because the front end of the crotch elastic member 27 in the front-back direction LD extends longer towards the abdominal side FS in the front-back direction LD, and the rear end of the crotch elastic member 27 in the front-back direction LD extends longer towards the back side BS in the front-back direction LD, the contraction force of the front-back direction LD becomes stronger as a whole, resulting in a state where it is pulled towards the front-back direction LD. As a result, it has the disadvantage of making it difficult to improve the fit of the leg-circle.

[0144] To prevent the aforementioned drawbacks, the ventral joint 90F and the dorsal joint 90B preferably have inclined portions 90FL, 90FR, 90BL, and 90BR formed on the left side FS and right side RS in the width direction WD. Furthermore, these inclined portions 90FL, 90FR, 90BL, and 90BR are not necessarily... Figure 8 The curved shape shown can also be changed to any shape, such as a straight line.

[0145] Furthermore, in the comparative examples 1 and 2 described above, examples with leg-circle elastic members 26 and crotch-area elastic members 27 were shown, but the examples are not limited to this manner. That is, the same can be said to apply when using stretch film or stretch nonwoven fabric instead of leg-circle elastic members 26 and crotch-area elastic members 27.

[0146] In addition, Figure 7 , Figure 11 , Figure 13 , Figure 15 In the perspective view, only the front part F and the crotch part C are shown, but the rear part B also has the same state. Therefore, as mentioned above, the shape of the back joint 90B of the rear part B is preferably formed as inclined portions 90BL and 90BR.

[0147] <Explanation of terms used in the instruction manual>

[0148] Unless otherwise specified in the instruction manual, the following terms shall have the following meanings.

[0149] • "Elongation" refers to the value when the natural length is set to 100%.

[0150] • "Unfolded state" refers to a state in which the body is flat and unfolded without shrinking or loosening.

[0151] Unless otherwise specified, the dimensions and positional relationships of each part refer to the dimensions in the unfolded state, not in the natural length state.

[0152] Industrial availability

[0153] This invention can be applied to disposable diapers in the form of briefs, as described above.

[0154] Label Explanation

[0155] 1: Flat-front shorts type disposable diaper; 7: Compression pad; 8: Stretch pad; 9: Back piece; 10: Inner body; 11: Top piece; 12: Liquid-proof pad; 13: Absorbent body; 14: Packaging piece; 16: Pleated elastic component; 18: Inner body joint; 19: Non-stretch area; 20: Outer body; 20F: Abdominal side outer body; 20C: Crotch area outer body; 20B: Back side outer body; 20D: Fold-back section; 21: Side seal; 22: Pleated piece; 24: Waist elastic component; 25: Waist area elastic component; 26: Leg circumference elastic component; 27: Crotch area elastic component; 29: 30: Leg opening edge; 31: Leg inner contact part; 49: Absorbing component; 50: Front pressing plate; 51: Rear pressing plate; 70: Integrated outer body; 71: Internal assembly; 72: Folded strip; 90: Joint; 90F: Abdominal joint; 90B: Back joint; BG: Three-dimensional pleats; F: Front part; C: Crotch part; B: Rear part; LD: Front-back direction; FS: Abdominal (front) side; BS: Back (rear) side; WD: Width direction; LS: Left side; RS: Right side; TD: Thickness direction; INS: Inner side; OUS: Outer side.

Claims

1. A disposable diaper in the shape of boxer shorts, characterized in that, The flat-leg shorts type disposable diaper has the following features: An outer garment having a ventral outer garment, a back outer garment, and a crotch outer garment, the crotch outer garment extending between the ventral outer garment and the back outer garment through the crotch of the wearer. as well as An inner body, which engages with the inner side of at least the crotch portion of the outer body, the inner body comprising an absorbent material. The two side edges of the ventral outer garment join the two side edges of the dorsal outer garment to form a waist opening and a pair of leg openings. The crotch area outer garment has a pair of inner leg contact portions, which extend in the width direction to one side and the other side, respectively, compared to the absorbent body. The portion along the edge of the leg opening, including the inner leg contact portions, forms a pair of leg tube portions surrounding the leg root side. The crotch-side end of the central portion of the abdominal outer garment in the width direction is joined to the crotch-side outer garment to form an abdominal joint portion. The crotch-side end of the central portion of the back-side outer garment in the width direction is joined to the crotch-side outer garment to form a back-side joint portion. The portion of the ventral outer garment along the edge of the leg opening and the portion of the dorsal outer garment along the edge of the leg opening are extendable in the width direction. The portion of the crotch area outer garment along the edge of the leg opening is extendable in the front-to-back direction. The ventral joint has: a left-side inclined portion extending ventrally from the left side toward the center in the width direction; a right-side inclined portion extending ventrally from the right side toward the center in the width direction; and a connecting portion connecting the left-side inclined portion and the right-side inclined portion. The point closest to the ventral side in the connecting portion of the ventral joint is designated as the ventral connection point. The back-side joint has: a left-side inclined portion extending towards the back side from the left side toward the center side in the width direction; a right-side inclined portion extending towards the back side from the right side toward the center side in the width direction; and a connecting portion connecting the left-side inclined portion and the right-side inclined portion. The point on the farthest side of the connecting portion of the far-side joint is designated as the far-side connection point. The distance from the point closest to the crotch of the dorsal joint to the dorsal connection point in the front-back direction is shorter than the distance from the point closest to the crotch of the ventral joint to the ventral connection point in the front-back direction.

2. The disposable diaper of the boxer shorts type according to claim 1, wherein, The left and right portions of the crotch area outer garment are extendable in the front-to-back direction, while the central portion is not extendable. The absorbent body is joined to the central portion of the crotch area outer garment in the width direction.

3. A method for manufacturing a disposable diaper in the form of boxer shorts, characterized in that, The method for manufacturing the disposable diaper in the shape of boxer shorts is the method for manufacturing the disposable diaper in the shape of boxer shorts as described in claim 1. The manufacturing method of the aforementioned boxer shorts-type disposable diaper includes the following steps: In the integrated outer garment forming process, at the crotch-side end of the portion of the abdominal outer garment that extends in the width direction and the crotch-side end of the portion of the back outer garment that extends in the width direction, a separately manufactured crotch-side outer garment that extends in the front-back direction is sequentially joined to form an integrated outer garment that integrates the abdominal outer garment, the crotch-side outer garment, and the back outer garment. The interior assembly process involves sequentially joining separately manufactured interior components in an unfolded state onto the integrated exterior to form an interior assembly. The folding process involves folding the internal assembly in the CD direction to form a folded strip. as well as The side joining and cutting process involves joining the abdominal outer garment and the back outer garment at the portions that form the two sides of each diaper in the folded strip, and cutting the abdominal outer garment and the back outer garment at the boundary of each diaper to obtain each diaper.

4. The method for manufacturing a disposable diaper in the shape of boxer shorts according to claim 3, wherein, In the integrated outer casing forming process, When the crotch side end of the part that will become the abdominal outer garment is joined with the crotch outer garment to form an abdominal joint, the joint is joined obliquely in such a way that it extends from the left and right sides in the width direction toward the central side toward the abdominal side.

5. The method for manufacturing a disposable diaper of the boxer shorts type according to claim 3 or 4, wherein, In the integrated outer casing forming process, When the crotch side end of the part that will become the back outer garment is joined to the crotch outer garment to form the ventral joint, the joint is joined obliquely in such a way that it extends from the left and right sides in the width direction toward the central side toward the back side.

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