JP2019000197A - Underpants type disposable diaper - Google Patents

Abstract

To improve leak prevention properties of leg peripheries by simple change, in an expansion and contraction structure in which leg peripheries and parts continuing therefrom are made of the same elastic film.SOLUTION: An underpants type disposable diaper is such that: a leg periphery R in a film lamination region 20X has a leg periphery extensible region 80 including an elastic film 30; in the leg periphery extensible region 80, a pleat formation part 90 in which a first sheet layer 20A is not in contact with the elastic film 30 and a second sheet layer 20B extends in a leg periphery direction while spacing an interval between an edge 29 of a leg opening; adjacent parts 91 opposed to each other across the pleat formation part 90 are parts in which the first sheet layer 20A and the second sheet layer 20B are connected by a sheet connecting part 40; and a dimension of the pleat formation part 90 in a direction orthogonal to the edge 29 of the leg opening is larger than a width direction interval 40b of the sheet connecting part 40 and a forward and backward direction interval 40d of the sheet connecting part 40 in the adjacent parts 91.SELECTED DRAWING: Figure 2

Description

  The present invention relates to a pants-type disposable diaper.

  The pants-type disposable diaper is an inner body including an outer body that forms at least a waist part of the front body and a waist part of the rear body, and an absorbent body that is attached to the inner surface of the outer body so as to extend from the front body to the rear body. The side opening of the outer body of the front body and the side edge of the outer body of the rear body are joined to form a side seal portion, thereby forming a waist opening and a pair of left and right leg openings. What is common is.

  The outer body of the pants-type disposable diaper is provided with elastic members such as rubber thread in the waist area that is defined as the front-rear direction range (the front-rear direction range from the waist opening to the upper end of the leg opening) with side seals. In general, as an elastic member for that purpose, a method in which a large number of elongated elastic members such as rubber thread are stretched in the longitudinal direction and fixed in a longitudinal direction has been widely used. However, a method of attaching an elastic film in a stretched direction in a stretchable direction has been proposed as having excellent fit as a surface. (For example, refer patent documents 1-4).

  The elastic region of the elastic film is formed by laminating an elastic film between a first sheet layer made of non-woven fabric and a second sheet layer made of non-woven fabric, and the elastic film is stretched in the elastic direction along their surfaces. In this state, the first sheet layer and the second sheet layer are through holes formed in the elastic film with a large number of dot-like sheet joint portions arranged at intervals in the stretching direction and the direction orthogonal thereto. It is formed by joining through. In the natural length state, the stretchable region due to the elastic film is such that, as the elastic film contracts between the sheet bonding portions, the interval between the sheet bonding portions becomes narrower, and the sheet bonding portions between the first sheet layer and the second sheet layer are reduced. A ridge extending in a direction intersecting with the expansion / contraction direction is formed on the surface. On the other hand, when the elastic film is stretched between the sheet joining portions, the gap between the sheet joining portions and the wrinkles in the first sheet layer and the second sheet layer are widened, and the first sheet layer and the second sheet layer are completely separated. Elastic extension is possible up to the deployed state. The stretchable region by the elastic film is excellent in surface fit, and there is no bonding between the first sheet layer and the second sheet layer and the elastic film, and the bonding between the first sheet layer and the second sheet layer is also possible. Since there are very few, it is very flexible, and the through-hole of an elastic film has the advantage that it contributes also to air permeability improvement.

  In a pants-type disposable diaper, when a stretchable structure using an elastic film is adopted for the exterior body, it is desirable to form a stretchable region as wide as possible with the same elastic film in order to simplify the structure and reduce material costs. . However, the elastic region of the elastic film usually cannot change the tightening force in the direction orthogonal to the elastic direction. In addition, if the elastic film is thinned to ensure flexibility, the elastic film becomes weak. If anything, the structure is unsuitable for exerting a strong clamping force. Furthermore, there is a limit to what the tightening force can be changed to some extent due to the change in the area ratio of the sheet joint portion (see, for example, Patent Document 4). For this reason, if a stretchable structure with the same elastic film is provided over the leg surrounding portion along the edge of the leg opening and the subsequent portion where a relatively strong tightening force is desired, the tightening force of the edge portion is insufficient. As a result, there was a risk that the leakage prevention property would be reduced.

  In addition, it has also been proposed to add an elongated elastic member such as rubber thread along the leg circumference to the leg circumference portion having the elastic film (see, for example, Patent Document 2). Although this technique is effective, the manufacturing process is complicated because the elongated elastic member is provided in the portion having the elastic film, and the product structure is also complicated. Therefore, it is desired to improve leakage prevention by another approach.

JP-T-2004-532758 Special table 2009-536845 International Publication No. 2008/126708 JP 2017-64226 A

  Therefore, the main problem of the present invention is to improve the leakage prevention performance of the leg-surrounding part by a simple change in the stretchable structure using the elastic film having the same leg-surrounding part and the subsequent part.

The pants type disposable diaper which solved the above-mentioned subject is as follows.
<First aspect>
In the pants-type disposable diaper in which the side edge of the front body and the side edge of the back body are joined on both sides in the width direction to form a waist opening and a leg opening,
An elastic film is laminated between the first sheet layer positioned on the skin side of the wearer and the second sheet layer positioned on the outer side of the leg surrounding portion and the subsequent portion along the edge of the leg opening. The first sheet layer and the second sheet layer have a film lamination region bonded directly or indirectly by a number of sheet bonding portions arranged at intervals,
The leg periphery portion in the film lamination region has a leg periphery expansion / contraction region that is contracted in the width direction and expandable in the width direction by contraction of the elastic film,
In the leg-surrounding stretchable region, a ridge-forming portion where the first sheet layer, the elastic film, and the second sheet layer are not joined extends in the leg-surrounding direction while being spaced from the edge of the leg opening. And
The adjacent parts facing each other across the ridge-forming part are parts where the first sheet layer and the second sheet layer are joined by the sheet joining part,
The size of the flange forming portion in the direction orthogonal to the edge of the leg opening is larger than the width-direction interval of the sheet bonding portion and the front-rear direction interval of the sheet bonding portion in the adjacent portion,
A pants-type disposable diaper characterized by that.

(Function and effect)
In this aspect, the leakage preventing ridge due to the shrinkage of the first sheet layer is formed on the skin side of the leg-surrounding stretchable region with the elastic film being contracted to some extent. Here, when the size of the ridge forming portion in the direction orthogonal to the edge of the leg opening is larger than the interval in the width direction of the sheet joint portion in the adjacent portion and the interval in the front-rear direction of the sheet joint portion, A high (large) leakage prevention ridge is formed, which becomes a weir extending in the direction around the leg. Therefore, according to this aspect, the leak-proof ridge that bulges to the skin side by a simple device that simply provides the above-described heel-forming portion (non-joined portion) and adjacent portion (joined portion) in the leg-stretchable region is a weir. Thus, it extends along the leg circumference, and the leakage prevention performance of the leg circumference portion is improved.

<Second aspect>
The pants-type disposable diaper according to the first aspect, wherein the second sheet layer is bonded to the elastic film via a hot melt adhesive at least in the heel-forming portion.

(Function and effect)
If the second sheet layer is not bonded to the elastic film at the wrinkle forming portion, not only the first sheet layer (skin side) but also the second sheet layer (outside) is formed with high wrinkles, so it is neat Appearance does not become. On the other hand, when the second sheet layer is bonded to the elastic film at the wrinkle forming portion as in this aspect, a high leakage preventing wrinkle is formed on the first sheet layer (skin side). Since the sheet layer (outside) is formed with low and fine wrinkles, it has a clean appearance while improving leakage prevention.

<Third Aspect>
The pants-type disposable diaper according to the first or second aspect, wherein the size of the heel-forming portion in the direction orthogonal to the edge of the leg opening is gradually or continuously enlarged as it approaches the crotch side.

(Function and effect)
As the leg circumference part is closer to the crotch side, leakage prevention becomes more important. Therefore, by changing the size of the heel-forming part in the direction perpendicular to the edge of the leg opening as in this aspect, the leg circumference part is formed on the leg circumference part. It is preferable to increase the height of the leakage prevention ridge as it approaches the crotch side.

<Fourth aspect>
The pants-type disposable diaper according to any one of the first to third aspects, wherein a plurality of the heel-forming portions are provided at intervals so as not to cross each other.

(Function and effect)
Since the leakage prevention ridge formed on the first sheet layer is flexible and deformable, there is a risk that a portion having a low damming action may be formed due to the formation of irregularities, etc., and only one piece has leakage prevention properties May be insufficient. Therefore, it is preferable to provide a plurality of wrinkle forming portions as in this embodiment.

<Fifth aspect>
The size of the flange forming portion in the direction orthogonal to the edge of the leg opening is 2 to 6 mm, the interval in the width direction of the sheet joint portion in the adjacent portion is 1 to 3 mm, and the sheet joint portion in the adjacent portion The front-rear direction interval is 0.5-2 mm,
The dimension of the flange forming portion in the direction orthogonal to the edge of the leg opening is 2 to 6 times the larger one of the width direction interval of the sheet joint portion and the front-rear direction interval of the sheet joint portion in the adjacent portion. ,
The underpants type disposable diaper of any one aspect of the 1st-4th.

(Function and effect)
The size of the ridge-forming portion and the interval in the width direction of the sheet joining portion in the direction orthogonal to the edge of the leg opening are not particularly limited, but in the normal case, it is preferably within the range described in this section.

  As described above, according to the present invention, in the stretchable structure using the same elastic film in the leg periphery portion and the subsequent portion, there are advantages such as being able to improve the leakage prevention performance of the leg periphery portion by a simple change. Brought about.

It is a top view (inner surface side) of the underpants type disposable diaper of a deployment state. It is a top view (outer surface side) of the underpants type disposable diaper of a deployment state. It is a top view which shows only the principal part of the underpants type disposable diaper of an unfolded state. (A) is CC sectional drawing of FIG. 1, (b) is EE sectional drawing of FIG. It is AA sectional drawing of FIG. It is BB sectional drawing of FIG. (A) is a principal part top view of an expansion-contraction area | region, (b) is DD sectional drawing of (a), (c) is sectional drawing in a mounting state, (d) is sectional drawing in a natural length state. (A) Trace diagram of micrograph from plane direction of sample stretch region, (b) Trace diagram of high magnification micrograph from plane direction, (c) Trace diagram of high magnification micrograph from perspective direction. (A) is a principal part top view of an expansion-contraction area | region, (b) is DD sectional drawing of (a), (c) is sectional drawing in a mounting state, (d) is sectional drawing in a natural length state. (A) Trace diagram of micrograph from plane direction of sample stretch region, (b) Trace diagram of high magnification micrograph from plane direction, (c) Trace diagram of high magnification micrograph from perspective direction. (A) is a principal part top view of a non-expandable area | region, (b) is DD sectional drawing of (a), (c) is sectional drawing in a mounting state, (d) is sectional drawing in a natural length state. It is the trace figure of the photograph of the non-stretching area | region of a sample. It is a principal part enlarged plan view of a non-expandable region. (A) Cross-sectional view in the unfolded state in the direction across the ridge-forming portion, (b) is a cross-sectional view in the mounted state, and (c) is a cross-sectional view in the natural length state. It is a top view (outer surface side) of the underpants type disposable diaper of a deployment state. (A) is CC sectional drawing of FIG. 15, (b) is EE sectional drawing of FIG. It is sectional drawing which shows roughly the principal part cross section of the exterior body extended to some extent. It is sectional drawing which shows roughly the principal part cross section of the exterior body extended to some extent. (A) Trace figure of the plane photograph of the sheet | seat junction part formed with the 1st welding form, (b) Trace figure of the plane photograph of the sheet | seat junction part formed with the 3rd welding form. It is the schematic of an ultrasonic sealing apparatus. It is a top view which shows the various arrangement | sequence examples of a sheet | seat junction part. (A) Cross-sectional view in the unfolded state in the direction across the ridge-forming portion, (b) is a cross-sectional view in the mounted state, and (c) is a cross-sectional view in the natural length state.

Hereinafter, an embodiment of the present invention will be described in detail with reference to the accompanying drawings. In addition, the dotted pattern part in sectional drawing has shown joining means, such as a hot-melt-adhesive.
1 to 6 show a pants-type disposable diaper. This pants-type disposable diaper (hereinafter also simply referred to as a diaper) is fixed to and integrated with an exterior body 20 that forms at least a waist part of the front body F and a waist part of the back body B. The interior body 10 has an absorbent body 13 interposed between a liquid-permeable top sheet 11 and a liquid-impermeable sheet 12. In manufacturing, after the back surface of the interior body 10 is joined to the inner surface (upper surface) of the exterior body 20 by a joining means such as a hot melt adhesive, the interior body 10 and the exterior body 20 are the front body F and the back body B. Are folded at the center in the front-rear direction (longitudinal direction), and the side seal portions 21 are formed by joining both sides thereof by heat welding or hot melt adhesive, thereby forming a waist opening and a pair of left and right A pants-type disposable diaper in which leg openings are formed.

(Structural example of interior body)
As shown in FIGS. 4 to 6, the inner body 10 has a structure in which an absorber 13 is interposed between a top sheet 11 and a liquid-impermeable sheet 12 made of polyethylene or the like. The excretory fluid that has passed through the sheet 11 is absorbed and retained. Although the planar shape of the interior body 10 is not particularly limited, it is generally a rectangular shape as shown in FIG.

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

  As the liquid-impermeable sheet 12 covering the back side (non-skin contact side) of the absorbent body 13, a liquid-impermeable plastic sheet such as polyethylene or polypropylene is used, but in recent years, it has moisture permeability from the viewpoint of preventing stuffiness. Are preferably used. This water-impervious and moisture-permeable sheet is a microporous sheet obtained by, for example, melt-kneading an inorganic filler in an olefin resin such as polyethylene or polypropylene to form a sheet, and then stretching in a uniaxial or biaxial direction. is there.

  Absorbent body 13 is a known one, for example, a pulp fiber stack, a filament aggregate such as cellulose acetate, or a non-woven fabric, mixed with a superabsorbent polymer as necessary, fixed, etc. Can be used. The absorbent body 13 can be packaged with a wrapping sheet 14 having liquid permeability and liquid retention, such as crepe paper, if necessary, for holding the shape and polymer.

  The shape of the absorber 13 is formed in a substantially hourglass shape having a narrowed portion 13N having a narrower width than the front and rear sides in the crotch portion, but may be an appropriate shape such as a rectangular shape. Although the size of the constricted portion 13N can be determined as appropriate, the length in the front-rear direction of the constricted portion 13N can be about 20 to 50% of the total length of the diaper, and the width of the narrowest portion is 40% of the total width of the absorber 13. It can be about -60%. In the case of having such a constricted portion 13N, if the planar shape of the interior body 10 is substantially rectangular, the remainder of the interior body 10 that does not have the absorber 13 in the portion corresponding to the constricted portion 13N of the absorber 13 A part is formed.

  A solid gather BS that fits around the legs is formed on both sides of the interior body 10. As shown in FIGS. 5 and 6, the three-dimensional gather BS includes a fixed portion fixed to a side portion on the back surface of the interior body, and a side portion on the surface of the interior body from the fixed portion to the side of the interior body. The body part that extends to the front, the front and rear ends of the body part in a lying state, and the lying part that is fixed to the side of the surface of the interior body, and the freedom part that is formed with this lying part being unfixed The part is formed of a gathered nonwoven fabric 15 that is turned into a double sheet by folding.

  Further, between the double sheets, an elongated gather elastic member 16 is disposed at the tip of the free part. The gather elastic member 16 is for forming a three-dimensional gather BS by raising a free part by elastic stretching force as shown by a two-dot chain line in FIG. 5 in the product state.

  The liquid-impermeable sheet 12 is folded back together with the top sheet 11 on both sides in the width direction of the absorber 13. As this liquid-impermeable sheet 12, it is desirable to use an opaque sheet so that brown color such as defecation and urine does not appear. As the opacification, a plastic film and a pigment and filler such as calcium carbonate, titanium oxide, zinc oxide, white carbon, clay, talc and barium sulfate are preferably used.

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

  In the same manner as the top sheet 11, the material fiber constituting the gathered nonwoven fabric 15 is not only synthetic fibers such as olefins such as polyethylene or polypropylene, polyesters, and amides, but also regenerated fibers such as rayon and cupra, and natural fibers such as cotton. Nonwoven fabric obtained by an appropriate processing method such as a spun bond method, a thermal bond method, a melt blown method, a needle punch method, etc. can be used. It is better to use a nonwoven fabric that suppresses and has excellent air permeability. Furthermore, for the gathered nonwoven fabric 15, silicone, paraffin metal, alkylchromic croid water repellent, etc. are used in order to prevent urine transmission and the like, as well as to prevent fogging and to improve skin feel (dry feeling). It is desirable to use a water-repellent non-woven fabric coated with.

  As shown in FIG. 3, the back surface of the interior body 10 is fixed to the inner surface of the exterior body 20 with a hot melt adhesive or the like in the inner / outer fixing area 10 </ b> B (shaded area). This inner / outer fixed region 10 </ b> B extends across the front and rear sides of the non-absorbent body side portion 17 with a width extending from one non-absorbent body side portion 17 to the other non-absorbent body side portion 17. The side edge of the inner / outer fixing region 10B is preferably located laterally from the middle in the width direction of the non-absorbent body side portion 17, and in particular, the exterior body over almost the whole width direction of the interior body 10 and almost the whole front and rear direction. More preferably, it is fixed to 20.

(External body structure example)
The exterior body 20 is an intermediate portion that is a front-rear direction range between a waistline portion T that is a front-rear direction range corresponding to the side seal portion 21, and a waistline portion T of the front body F and a waistline portion T of the rear body B. L. And in the exterior body 20 of the illustrated form, the first sheet layer 20A located on the skin side of the wearer, as shown in FIG. 2 and FIGS. More than that, the elastic film 30 is laminated between the second sheet layers 20B, and as shown in FIG. 7, the first sheet layers 20A and the second sheet layers 20B are arranged in a large number at intervals. It has the film lamination | stacking area | region 20X by which the expansion-contraction direction was made into the width direction joined through the through-hole 31 which penetrates the elastic film 30 in the sheet | seat junction part 40. The first sheet layer 20 </ b> A and the second sheet layer 20 </ b> B may be indirectly joined through the elastic film 30 instead of through the through hole 31 of the elastic film 30. As for the planar shape of the exterior body 20, the concave portions at both side edges of the intermediate portion L are the edges 29 of the leg openings, and the shape is like an hourglass as a whole. The exterior body 20 may be divided into two parts in the front-rear direction so that both are separated in the front-rear direction at the crotch part.

  The form shown in FIGS. 1 and 2 is a form in which the film lamination region 20X extends to the waist end region 23, but the tightening of the waist end region 23 is insufficient only by expansion and contraction by the film lamination region 20X. As shown in FIGS. 15 and 16, the elastic structure is formed by a conventional elongated waist elastic member 24 without providing (or providing) the film lamination region 20 </ b> X in the waist end region 23 as shown in FIGS. 15 and 16. 20X can also be provided. The waist elastic member 24 is an elongated elastic member such as a plurality of thread rubbers arranged at intervals in the front-rear direction, and gives an elastic force so as to tighten around the body torso. The waist elastic members 24 are not arranged substantially as a single bundle with a close interval, but with a spacing of about 3 to 8 mm so as to form a predetermined stretch zone, preferably three or more, preferably Five or more are arranged. The stretch rate at the time of fixing the waist elastic member 24 can be determined as appropriate, but can be about 230 to 320% in the case of a normal adult. For the waist elastic member 24, thread rubber is used in the illustrated example, but other elongated elastic members such as flat rubber may be used.

  As other forms, although not shown in the figure, the intermediate part L between the waist part T of the front body F and the waist part T of the back body B is not provided with the film lamination region 20X, or the front body F The stretchable structure 20X is continuously provided in the front-rear direction from the inside of the waist part T to the inside of the waist part T of the back body B through the intermediate part L, or the film is laminated only on either the front body F or the back body B It is also possible to provide the region 20X.

  Although the shape in the natural length state of each sheet | seat junction part 40 and the through-hole 31 can be determined suitably, a perfect circle (refer FIG. 7, FIG. 8), an ellipse, a triangle, a rectangle (refer FIG. 9-12). ), Rhombus (see FIG. 13B), etc., or convex lens shape (see FIG. 13A), concave lens shape (see FIG. 13C), star shape, cloud shape, etc. be able to. The dimensions of the individual sheet joints are not particularly limited, but the maximum length is preferably 0.5 to 3.0 mm, particularly preferably 0.7 to 1.1 mm, and the maximum width 40x is 0.1 to 3.0 mm. In particular, when the shape is long in the direction orthogonal to the expansion and contraction direction, the thickness is preferably 0.1 to 1.1 mm.

The size of each sheet bonding portion 40 may be determined as appropriate. However, if the size is too large, the hardness of the sheet bonding portion 40 has an effect on the touch. If the size is too small, the bonding area is small and the materials are sufficiently bonded to each other. Since it becomes impossible, it is preferable that the area of each sheet | seat junction part 40 shall be about 0.14-3.5 mm < ² > normally. The area of the opening of each through hole 31 may be equal to or greater than the sheet joint portion because the sheet joint portion is formed through the through hole 31, but is about 1 to 1.5 times the area of the sheet joint portion. It is preferable. In addition, the area of the opening of the through-hole 31 means a value in a state of being integrated with the first sheet layer 20A and the second sheet layer 20B, not in the state of the elastic film 30 alone, and in a natural length state. When the area of the opening 31 is not uniform in the thickness direction, such as when the elastic film 30 is different from the front and back, it means the minimum value.

  The planar arrangement of the sheet joint portion 40 and the through-holes 31 can be determined as appropriate, but a regularly repeated planar arrangement is preferable, and an oblique lattice shape as shown in FIG. Hexagonal lattice shape as shown (these are also called zigzag shapes), square lattice shape as shown in FIG. 21 (c), rectangular lattice shape as shown in FIG. 21 (d), as shown in FIG. 21 (e) Parallel body lattice (as shown in the figure, two groups are provided so that a large number of groups of parallel diagonal rows intersect each other), etc. (these are inclined at an angle of less than 90 degrees with respect to the expansion and contraction direction And a group of sheet joint portions 40 (group unit arrangement may be regular or irregular, and may be a pattern or a letter shape) is regularly repeated. You can also

  The first sheet layer 20 </ b> A and the second sheet layer 20 </ b> B in the sheet bonding portion 40 are bonded through the through-hole 31 formed in the elastic film 30. In this case, it is desirable that the elastic film 30 is not bonded at least except between the first sheet layer 20A and the second sheet layer 20B in the sheet bonding portion 40.

  The joining means of the first sheet layer 20A and the second sheet layer 20B in the sheet joining portion 40 is not particularly limited. For example, the joining of the first sheet layer 20A and the second sheet layer 20B in the joining portion 40 may be performed by a hot melt adhesive, or may be performed by a joining means such as heat sealing or ultrasonic sealing.

  When the first sheet layer 20 </ b> A and the second sheet layer 20 </ b> B are bonded through the through hole 31 in the sheet bonding portion 40, the form in which the sheet bonding portion 40 is formed by material welding is the first sheet layer 20 </ b> A in the sheet bonding portion 40. And a first welding form in which the first sheet layer 20A and the second sheet layer 20B are joined only by the majority or part of the molten solidified material 20m of at least one of the second sheet layer 20B (see FIG. 17A), The second welding mode in which the first sheet layer 20A and the second sheet layer 20B are joined by all or most of the elastic film 30 in the sheet joining portion 40 or only a part of the melt-solidified material 30m (see FIG. 17B). , And a third welding form in which both of these are combined (see FIG. 17 (c)), but the second and third welding forms are preferable. Particularly preferably, the first sheet layer is composed of a part of the melt-solidified material 20m of the first sheet layer 20A and the second sheet layer 20B and the whole or most of the melt-solidified material 30m of the elastic film 30 in the sheet joint portion 40. 20A and the second sheet layer 20B are joined together. In the third welding mode shown in FIG. 19B, the elastic film 30 appears in white between the melt-solidified products 20m of the fibers of the first sheet layer 20A or the second sheet layer 20B shown in black. In the first welding form shown in FIG. 19A, an elastic film is formed between the melt-solidified products 20m of the fibers of the first sheet layer 20A or the second sheet layer 20B. A melt-solidified product is not observed (the white part is the boundary between the fiber melt-solidified product 20 m and the diffuse reflection of the fiber melt-solidified product 20 m).

  As in the first adhesive form and the third adhesive form, the first sheet layer 20A and the second sheet 20A and the second sheet 20A and the second sheet layer 20B are used by using at least one of the first sheet layer 20A and the second sheet layer 20B as the adhesive. When joining the sheet layer 20B, it is preferable not to melt part of the first sheet layer 20A and the second sheet layer 20B because the sheet joining part 40 does not harden. Note that when the first sheet layer 20A and the second sheet layer 20B are non-woven fabrics, a part of the first sheet layer 20A and the second sheet layer 20B does not melt. The composite fiber contains not only the core but also the central part of the single component fiber), but the surrounding part (including not only the sheath but also the surface part of the single component fiber of the composite fiber) melts, The fibers do not melt at all, but the remaining fibers either completely melt or the core remains but the surrounding portion includes a molten form.

  When the first sheet layer 20A and the second sheet layer 20B are joined using the melt-solidified material 30m of the elastic film 30 as an adhesive as in the second welding form and the third welding form, the peel strength becomes high. In the second welding mode, the first sheet layer 20A and the second sheet layer 20B have a melting point that is higher than the melting point of the elastic film 30 and the heating temperature when forming the sheet joint 40. In addition, the elastic film 30 is sandwiched between the second sheet layers 20 </ b> B, the portion to be the sheet bonding portion 40 is pressurized and heated, and only the elastic film 30 is melted. On the other hand, in the third welding mode, the first sheet layer 20A and the second sheet layer 20B are between the first sheet layer 20A and the second sheet layer 20B under the condition that the melting point of at least one of the first sheet layer 20A and the second sheet layer 20B is higher than the melting point of the elastic film 30. It can be manufactured by sandwiching the elastic film 30, pressurizing and heating a portion to be the sheet bonding portion 40, and melting at least one of the first sheet layer 20 </ b> A and the second sheet layer 20 </ b> B and the elastic film 30. From such a viewpoint, the melting point of the elastic film 30 is preferably about 80 to 145 ° C., and the melting points of the first sheet layer 20A and the second sheet layer 20B are about 85 to 190 ° C., particularly about 150 to 190 ° C. The difference between the melting points of the first sheet layer 20A and the second sheet layer 20B and the melting point of the elastic film 30 is preferably about 60 to 90 ° C. Moreover, it is preferable that heating temperature shall be about 100-150 degreeC.

  In the second welding mode and the third welding mode, when the first sheet layer 20A and the second sheet layer 20B are non-woven fabrics, the melt-solidified product 30m of the elastic film 30 is a sheet joint portion as shown in FIG. 40 may penetrate between the fibers in the entire thickness direction of the first sheet layer 20A and the second sheet layer 20B, but as shown in FIGS. 17 (b) (c) and 18 (a), it is intermediate in the thickness direction. The form that penetrates between the fibers up to or the form that hardly penetrates between the fibers of the first sheet layer 20A and the second sheet layer 20B as shown in FIG. It will be a thing.

  FIG. 20 shows an example of an ultrasonic sealing device suitable for forming the second welding form and the third welding form. In this ultrasonic sealing apparatus, when the sheet bonding portion 40 is formed, the first sheet layer 20A, between the anvil roll 60 and the ultrasonic horn 61, each having a projection 60a formed in the pattern of the sheet bonding portion 40 on the outer surface, The elastic film 30 and the second sheet layer 20B are fed. At this time, for example, the feeding driving speed of the upstream elastic film 30 by the feeding driving roll 63 and the nip roll 62 is made slower than the feeding speed after the anvil roll 60 and the ultrasonic horn 61, thereby the feeding driving roll 63 and the nip roll 62. The elastic film 30 is stretched in the MD direction (machine direction, flow direction) to a predetermined stretch rate through the path from the nip position due to the above to the seal position due to the anvil roll 60 and the ultrasonic horn 61. The stretch rate of the elastic film 30 can be set by selecting the speed difference between the anvil roll 60 and the feed drive roll 63, and can be set to about 300% to 500%, for example. The first sheet layer 20 </ b> A, the elastic film 30, and the second sheet layer 20 </ b> B fed between the anvil roll 60 and the ultrasonic horn 61 are stacked in this order, and the protrusion 60 a and the ultrasonic horn 61 are While being pressurized, the ultrasonic horn 61 is heated by ultrasonic vibration energy to melt only the elastic film 30 or at least one of the first sheet layer 20A and the second sheet layer 20B and the elastic film 30 are melted. By doing so, the first sheet layer 20 </ b> A and the second sheet layer 20 </ b> B are joined through the through-hole 31 at the same time as the through-hole 31 is formed in the elastic film 30. Therefore, in this case, by selecting the size, shape, separation interval, arrangement pattern in the roll length direction and roll circumferential direction, etc., of the projections 60a of the anvil roll 60, the area ratio of the sheet joining portion 40 is selected. Can do.

  The reason why the through hole 31 is formed is not necessarily clear, but it is considered that the hole corresponding to the protrusion 60a of the anvil roll 60 in the elastic film 30 is melted and separated from the surroundings. At this time, a portion of the elastic film 30 between the through holes 31 adjacent to each other in the expansion / contraction direction is expanded / contracted by the through holes 31 as shown in FIGS. 7 (a), 9 (a), and 11 (a). Since it is cut from both sides and loses the support on both sides in the contraction direction, the central side in the direction orthogonal to the expansion / contraction direction is balanced with the central side in the expansion / contraction direction within a range that can maintain continuity in the direction orthogonal to the contraction direction. The through hole 31 expands in the expansion / contraction direction. And when the sheet | seat junction part 40 is formed in the pattern in which the part which the elastic film 30 continues linearly along the expansion-contraction direction like the expansion-contraction area | region 80 mentioned later is shown in FIG.7 (d) and FIG.9 (d). Thus, when contracting to a natural length state by cutting into individual products, the length in the expansion / contraction direction of the enlarged portion of the through hole 31 creates a gap between the through hole 31 and the sheet joining portion 40. It will shrink until it runs out. On the other hand, when the sheet joining portion 40 is formed in a pattern in which the elastic film 30 does not have a linearly continuous portion along the stretching direction as in a non-stretchable region 70 described later, as shown in FIG. Since it hardly shrinks when it is shrunk to a natural length state by cutting into a product or the like, a large gap is left between the through hole 31 and the sheet bonding portion 40.

The constituent material of the first sheet layer 20A and the second sheet layer 20B can be used without particular limitation as long as it is a sheet, but it is preferable to use a nonwoven fabric from the viewpoint of air permeability and flexibility. The nonwoven fabric is not particularly limited as to what the raw fiber is. For example, synthetic fibers such as olefins such as polyethylene and polypropylene, polyesters and polyamides, recycled fibers such as rayon and cupra, natural fibers such as cotton, and mixed fibers and composite fibers using two or more of them. Etc. can be illustrated. Furthermore, the nonwoven fabric may be manufactured by any processing. Examples of the processing method include known methods such as a spunlace method, a spunbond method, a thermal bond method, a melt blown method, a needle punch method, an air through method, and a point bond method. When using a nonwoven fabric, the basis weight is preferably about 12 to ²⁰ g / m ² . Moreover, a part or all of the first sheet layer 20A and the second sheet layer 20B may be a pair of layers in which one material is folded and faced. For example, as shown in the figure, in the waist end region 23, the constituent material located outside is the second sheet layer 20B, and the folded portion 20C that is folded back to the inner surface side at the waist opening edge is the first sheet layer 20A. In addition, the elastic film 30 is interposed therebetween, and in the other portions, the constituent material positioned inside is the first sheet layer 20A, and the constituent material positioned outside is the second sheet layer 20B, and the elastic film 30 is interposed therebetween. Can be interposed. Of course, the constituent material of the first sheet layer 20A and the constituent material of the second sheet layer 20B are individually provided over the entire front-rear direction, and the constituent material of the first sheet layer 20A and the second sheet layer are not folded back. The elastic film 30 can also be interposed between the constituent materials of 20B.

  The elastic film 30 is not particularly limited, and as long as it is a thermoplastic resin film having elasticity per se, a film having a large number of holes and slits for ventilation can also be used. . In particular, the tensile strength in the width direction (stretching direction, MD direction) is 8 to 25 N / 35 mm, the tensile strength in the front-rear direction (direction perpendicular to the stretching direction, CD direction) is 5 to 20 N / 35 mm, and the tensile elongation in the width direction. Is preferably 450 to 1050%, and the elastic film 30 having a tensile elongation in the front-rear direction of 450 to 1400%. Although the thickness of the elastic film 30 is not specifically limited, It is preferable that it is about 20-40 micrometers.

(Stretchable area and non-stretchable area)
The film lamination region 20 </ b> X in the exterior body 20 includes a non-stretchable region 70 and a stretchable region 80 that can be stretched in the width direction, and the stretchable region 80 is located in a leg-around portion R along the edge 29 of the leg opening. It has an elastic area around the legs. The arrangement of the stretchable region 80 and the non-stretchable region 70 can be changed as appropriate. In the case of the exterior body 20 of the pants-type disposable diaper as in the present embodiment, the portion overlapping the absorber 13 is an area that does not need to be expanded and contracted, and therefore, part or all of the portion overlapping the absorber 13 as illustrated. It is preferable to make the non-stretchable region 70 (desirably including almost the entire inner and outer fixed region 10B). Of course, the non-stretchable region 70 can be provided from the region overlapping with the absorber 13 to the region not overlapping with the absorber 13 positioned in the width direction or the front-rear direction, and the non-stretchable region 70 is provided only in the region not overlapping with the absorber 13. It can also be provided.

  Moreover, in order to extend the heel forming portion 90 described later to the crotch side than the illustrated example, the width of the non-stretchable region 70 may be narrowed, the crotch width of the exterior body 20 may be widened, or both. it can.

(Elastic area)
In the stretchable region 80, the elastic film 30 has a portion 32 linearly continuous along the width direction, and is contracted in the width direction by the contraction force of the elastic film 30, and can be expanded in the width direction. It has become. More specifically, in a state where the elastic film 30 is extended in the width direction, the through-holes 31 of the elastic film 30 are formed at intervals in the width direction and in the front-rear direction (direction orthogonal to the expansion / contraction direction) orthogonal thereto. The first sheet layer 20A and the second sheet layer 20B are joined together to form a large number of sheet joint portions 40, thereby forming the film lamination region 20X including both the stretch region 80 and the non-stretch region 70, In the stretchable region 80, such stretchability can be imparted by arranging the through holes 31 so that the elastic film 30 has a linearly continuous portion along the width direction.

  In the stretchable region 80, in the natural length state, as shown in FIGS. 7D and 9D, the first sheet layer 20A and the second sheet layer 20B between the sheet joining portions 40 swell in a direction away from each other. Thus, a collar 25 extending in the front-rear direction is formed. As shown in FIGS. 7 (c) and 9 (c), the collar 25 is stretched but remains even in a mounted state that extends to some extent in the width direction. Yes. Further, as illustrated, the first sheet layer 20A and the second sheet layer 20B are not joined to the elastic film 30 except at least between the first sheet layer 20A and the second sheet layer 20B in the sheet joining portion 40. FIGS. 7 (c) and 9 (c) assuming the mounted state, and FIGS. 7 (a) (b) and 9 (a) (9) assuming the expanded state of the first sheet layer 20A and the second sheet layer 20B. As can be seen from b), in these states, a gap is formed between the through hole 31 in the elastic film 30 and the sheet joint portion 40, and the material of the elastic film 30 is a non-porous film or sheet. However, air permeability is added by this gap. Further, in the natural length state shown in FIG. 7D and FIG. 9D, the through hole 31 is squeezed due to the contraction of the elastic film 30, and almost no gap is formed between the through hole 31 and the sheet joining portion 40. Not. In addition, the state of the collar 25 in the mounted state and the natural length state also appears in the trace diagrams of the sample photographs in FIGS. 8 and 10.

  The elastic limit elongation in the width direction of the stretchable region 80 is desirably 200% or more (preferably 265 to 295%). The elastic limit elongation of the stretchable region 80 is substantially determined by the stretch rate of the elastic film 30 at the time of manufacture, but based on this, it is lowered by a factor that inhibits shrinkage in the width direction. The main factor of such inhibition is the ratio of the length 40x of the sheet joint portion 40 per unit length in the width direction, and the elastic limit elongation decreases as the ratio increases. In a normal case, the length 40x of the sheet bonding portion 40 has a correlation with the area ratio of the sheet bonding portion 40, so that the elastic limit elongation of the stretchable region 80 can be adjusted by the area ratio of the sheet bonding portion 40.

  The elongation stress of the stretchable region 80 can be adjusted mainly by the sum of the widths 32w of the portions 32 where the elastic film 30 continues linearly along the width direction. The width 32w of the portion 32 in which the elastic film 30 is linearly continuous along the width direction is equal to the interval 31d in the front-rear direction of the through-holes 31 in contact with both side edges of the continuous portion 32. 31d is when the length 31y of the through-hole 31 in the front-rear direction is equal to the length 40y of the sheet-joint portion 40 in the front-rear direction (when the above-described simultaneous formation method of the through-hole 31 and the sheet joint 40 is employed) ) Is equal to the interval 40d in the front-rear direction of the sheet joining portion 40 in contact with both side edges of the continuous portion. Therefore, in this case, the extension stress of the stretchable region 80 can be adjusted by the ratio of the length 40y of the sheet joint portion 40 per unit length in the front-rear direction. Since the length 40y has a correlation with the area ratio of the sheet bonding portion 40, the elongation stress of the stretchable region 80 can be adjusted by adjusting the length of the sheet bonding portion 40 by the area ratio of the sheet bonding portion 40. The elongation stress of the expansion / contraction region 80 can be determined based on the elongation stress when it is expanded to 50% of the elastic limit.

The area ratio of the sheet bonding portion 40 and the area of each sheet bonding portion 40 in the stretchable region 80 can be determined as appropriate, but in the normal case, it is preferably within the following range.
Area of sheet joint 40: 0.14 to 3.5 mm ² (particularly 0.14 to 1.0 mm ² )
Area ratio of sheet joint portion 40: 1.8 to 19.1% (particularly 1.8 to 10.6%)

  As described above, since the elastic limit elongation and the extension stress of the stretchable region 80 can be adjusted by the area of the sheet joint portion 40, a plurality of regions having different area ratios of the sheet joint portion 40 in the stretchable region 80 as shown in FIG. The fitting property can be changed according to the part. In the form shown in FIG. 15, the area 81 extending in the oblique direction along the base of the leg in the front body F and the edge area 82 of the leg opening have a higher area ratio of the sheet joint portion 40 than the other areas. Therefore, the extensional stress is weak and the region expands and contracts flexibly. In addition, the iliac facing region 83 and the edge region 82 of the leg opening in the back body B also have a higher area ratio of the sheet joint portion 40 than the other regions, and therefore the extension stress is weak and the region expands and contracts flexibly. It has become.

(Non-stretchable area)
On the other hand, the non-stretchable region 70 is a region that does not have a linearly continuous portion along the width direction due to the presence of the through hole 31, although the elastic film 30 is continuous in the width direction. Therefore, in a state where the elastic film 30 is extended in the width direction, the first sheet layer 20 </ b> A and the second sheet layer are spaced via the through-holes 31 of the elastic film 30 with an interval in the width direction and the front-rear direction orthogonal thereto. Even if the entire film laminated region 20X including both the stretchable region 80 and the non-stretchable region 70 is formed by joining 20B and forming a large number of sheet joint portions 40, as shown in FIG. 70, since the elastic film 30 is not linearly continuous along the width direction, the contraction force of the elastic film 30 hardly acts on the first sheet layer 20A and the second sheet layer 20B, and the stretchability is almost lost. The elastic limit elongation is close to 100%. In such a non-stretchable region 70, the first sheet layer 20 </ b> A and the second sheet layer 20 </ b> B are joined by a large number of sheet joining portions 40 arranged at intervals, and the sheet joining portion 40 is not continuous. Therefore, a decrease in flexibility is prevented. In other words, the stretchable region 80 and the non-stretchable region 70 can be formed by the presence or absence of a portion where the elastic film 30 does not continue linearly along the width direction. Also, the continuity of the elastic film 30 remains in the non-stretchable region 70, and as can be seen from the trace diagram of the sample photograph shown in FIG. Since it is not formed, it looks very good and the air permeability in the thickness direction by the through hole 31 is ensured. The non-stretchable region 70 preferably has an elastic limit elongation in the width direction of 120% or less (preferably 110% or less, more preferably 100%).

  Although the arrangement pattern of the through holes 31 in the elastic film 30 in the non-stretchable region 70 can be determined as appropriate, it is arranged in a staggered manner as shown in FIG. If the pattern is shorter than the length 31y in the direction, the linear continuity in the width direction can be almost completely eliminated while maintaining the continuity of the elastic film 30, and the appearance is preferable as shown in FIG. In this case, it is more preferable that the center interval 31f in the width direction of the through hole 31 is shorter than the length 31x of the through hole 31 in the width direction.

  In a normal case, in particular, when the elastic film 30 has a stretching stress of 4.0 to 12 N / 35 mm when stretched four times in the width direction, the non-stretchable region 70 is stretched to the elastic limit in the width direction. The center distance 31e in the front-rear direction of the through-hole 31 is 0.4 to 2.7 mm, and the length 31y in the front-rear direction of the through-hole 31 is 0.5 to 3.0 mm, particularly 0.7 to 1.1 mm. And preferred. Further, the center interval 31f in the width direction of the through holes 31 is preferably 0.5 to 2.0 times, particularly 1.0 to 1.2 times the length 31y of the through holes 31 in the front-rear direction. The length 31x in the width direction of 31 is preferably 1.1 to 1.8 times, particularly 1.1 to 1.4 times the center interval 31f in the width direction of the through hole 31. In the state in which the non-stretchable region 70 is extended to the elastic limit in the width direction (in other words, the first sheet layer 20A and the second sheet layer 20B are completely expanded), the center interval 31f in the width direction of the through hole 31 Is equal to the center interval 40f in the width direction of the sheet bonding portion 40, the center interval 31e in the front-rear direction of the through-hole 31 is equal to the center interval 40e in the front-rear direction of the sheet bonding portion 40, and the length 31y in the front-rear direction of the through-hole 31 Is equal to the length 40y in the front-rear direction of the sheet joint 40.

  In the non-stretchable region 70, the first sheet layer 20A and the second sheet layer 20B and the elastic film 30 are not joined except for the portion between the first sheet layer 20A and the second sheet layer 20B in the sheet joining portion 40, And when it has a gap formed by separating the peripheral edge of the through hole 31 of the elastic film 30 and the sheet bonding portion 40 on both sides in the width direction of the sheet bonding portion 40 in a natural length state, the material of the elastic film 30 is Even a non-porous film or sheet is preferable because air permeability is always added by this gap. In the case where the above-described simultaneous formation method of the through hole 31 and the sheet joint portion 40 is adopted, this state naturally occurs regardless of the shape or the like of the sheet joint portion 40.

  Although the shape in the natural length state of each sheet | seat junction part 40 and the through-hole 31 is not specifically limited, In order to eliminate the linear continuity of the width direction of the elastic film 30, it is desirable that an area is small from a softness | flexibility viewpoint. Since it is desirable to have a shape that is long in the front-rear direction, an ellipse that is long in the front-rear direction, a rectangle (see FIGS. 11 and 13D), a rhombus (see FIG. 13B), and a convex lens shape (see FIG. 13). (See (a)), and preferably a concave lens shape (see FIG. 13C). However, if the corner is an acute angle like a diamond, the elastic film 30 is easily broken. On the other hand, the convex lens shape is preferable because the welding of the sheet joining portion 40 is stable, and the concave lens shape is preferable in that the area can be further reduced.

Although the area ratio of the sheet joint portion 40 and the area of each sheet joint portion 40 in the non-stretchable region can be determined as appropriate, in the normal case, if within the following range, the area of each sheet joint portion 40 is small and the sheet It is preferable that the non-stretchable region 70 does not become hard due to the low area ratio of the joint 40.
Area of sheet joint 40: 0.10 to 0.75 mm ² (particularly 0.10 to 0.35 mm ² )
Area ratio of sheet joint 40: 4 to 13% (especially 5 to 10%)

  As described above, the elastic limit elongation of the non-stretchable region 70 can be changed by the arrangement pattern of the through holes 31, the dimensions of the individual through holes 31, and the center interval. Therefore, although not shown, these can be made different at a plurality of locations in the stretchable region 80 or between the plurality of non-stretchable regions 70. For example, it is one preferable mode to make the elastic limit elongation in the non-stretchable region 70 of the front body F larger than the elastic limit elongation in the non-stretchable region 70 of the rear body B.

  Although the non-stretchable region 70 has a portion that is linearly continuous along the width direction like the stretchable region, the elastic limit elongation is remarkable because the area ratio of the sheet joint portion is higher than the stretchable region. It is also possible to adopt a form that kills other stretchability, such as a form that is 130% or less, a form that is cut at one place or a plurality of places in the width direction, such as a stretchable structure using a conventional rubber thread.

(Wrinkle forming part)
Characteristically, as in the examples shown in FIGS. 2 and 14, the first sheet layer 20 </ b> A, the elastic film 30, and the second sheet layer 20 </ b> B are formed in the leg-surrounding stretchable region located in the leg-surrounding portion R in the stretchable region 80. The heel forming portion 90 to which the three members are not joined extends along the edge 29 of the leg opening while being spaced from the edge 29 of the leg opening, and is adjacent to the adjacent portion 91 across the heel forming portion 90. Is a portion where the first sheet layer 20A and the second sheet layer 20B are joined by the sheet joining portion 40, and the dimension 90d of the heel forming portion 90 in the direction perpendicular to the edge 29 of the leg opening is the adjacent portion 91. This is larger than the interval 40b in the width direction of the sheet bonding portion 40 and the interval 40d in the front-rear direction of the sheet bonding portion 40.

  The dimension 90d of the flange forming portion 90 in the direction orthogonal to the edge 29 of the leg opening is not particularly limited as long as it is larger than the width-direction interval 40b of the sheet joining portion 40 and the front-rear direction interval 40d of the sheet joining portion 40 in the adjacent portion 91. In a normal case, it is preferably 2 to 6 times the larger of the interval 40b in the width direction of the sheet bonding portion 40 and the interval 40d in the front-rear direction of the sheet bonding portion 40 in the adjacent portion 91.

  As described above, in the mounted state in which the elastic film 30 is contracted to some extent, the collar 25 is formed in the stretchable region 80 including the leg stretchable region by contraction of the first sheet layer 20A and the second sheet layer 20B. Here, when the dimension 90d of the flange forming portion 90 in the direction orthogonal to the edge 29 of the leg opening is larger than the width-direction interval 40b of the sheet bonding portion 40 and the front-rear direction interval 40d of the sheet bonding portion 40 in the adjacent portion 91, The heel forming portion 90 is formed with a leakage preventing ridge 25B which is higher (larger) than the adjacent portion 91, and this becomes a weir extending in the direction around the legs. Therefore, the leakage prevention rod 25B that bulges to the skin side is like a weir with a simple contrivance that merely provides the above-described wrinkle forming portion 90 (non-joined portion) and adjacent portion 91 (joint portion) in the leg stretchable region. It will extend in the leg-circumferential direction, and the leakage preventing property of the edge 29 portion of the leg opening will be improved.

  The wrinkle forming portion 90 may not be bonded to the first sheet layer 20A, the elastic film 30, and the second sheet layer 20B. However, as in the example shown in FIG. 14, if the second sheet layer 20 </ b> B is not joined to the elastic film 30 in the wrinkle forming portion 90, not only the first sheet layer 20 </ b> A (skin side) but also the second sheet layer 20 </ b> B. Since the high collar 25 is formed also on the (outside), it does not have a clean appearance. On the other hand, as shown in FIG. 22, when the second sheet layer 20B is bonded to the elastic film 30 via the hot melt adhesive 30H at least in the wrinkle forming portion 90, the first sheet layer 20A (skin A high leakage prevention ridge 25B is formed on the side), but a low and fine ridge 25 is formed on the second sheet layer 20B (outside), thus improving the leakage prevention performance and providing a clean appearance. .

  The dimension 90d of the heel-forming portion 90 in the direction orthogonal to the edge 29 of the leg opening may be constant in the leg-circumferential direction. However, as the leg-peripheral portion R is closer to the crotch side, leakage prevention becomes more important. Therefore, as shown in the example, the dimension 90d of the heel forming portion 90 in the direction orthogonal to the edge 29 of the leg opening is continuously increased (or may be stepped) as it approaches the crotch side, and the leg surrounding portion R is increased. It is preferable to increase the height of the leakage preventing collar 25B formed as it approaches the crotch side.

The dimension 90d of the flange forming portion 90 in the direction orthogonal to the edge 29 of the leg opening, the width-direction interval 40b of the sheet bonding portion 40, and the interval 40d in the front-rear direction of the sheet bonding portion 40 in the adjacent portion 91 are not particularly limited. In this case, it is desirable to be within the following range.
Dimension 90d of heel-forming portion 90 in the direction orthogonal to leg opening edge 29: 2 to 6 mm
Width direction interval 40b of the sheet joint portion 40 in the adjacent portion 91: 1 to 3 mm
Front-rear direction interval 40d of the sheet joint portion 40 in the adjacent portion 91: 0.5 to 2 mm

  The number of wrinkle forming portions 90 can be determined as appropriate, and can be one as in the example shown in FIG. However, since the leakage prevention rod 25B formed on the first sheet layer 20A is flexible and deformable, there is a risk that a portion having a low damming action may be formed due to the formation of irregularities, etc. There is a risk that the leakage prevention property is insufficient. Therefore, as in the example shown in FIG. 2, it is preferable to provide a plurality of ridge forming portions 90 at intervals so as not to cross each other. The interval between the heel forming portions 90 in the direction orthogonal to the edge 29 of the leg opening can be determined as appropriate, but is 0.5 to 3 times the dimension 90d of the heel forming portion 90 in the direction orthogonal to the edge 29 of the leg opening. It is preferable to do.

(Front / rear holding sheet)
As shown in FIGS. 1 and 4, in order to cover the front and rear end portions of the interior body 10 attached on the inner surface of the exterior body 20 and to prevent leakage from the front and rear edges of the interior body 10, 51 and 52 may be provided. Explaining in more detail about the illustrated form, the front presser sheet 51 extends in the width direction from the inner surface of the folded portion 20C of the waist end region 23 to the position overlapping the front end portion of the inner body 10 in the inner surface of the outer body 20 of the front body F. The rear pressing sheet 52 extends in the width direction from the inner surface of the folded portion 20C of the waist end region 23 to the position overlapping the rear end portion of the inner body 10 in the inner surface of the outer body 20 of the back body B. It extends throughout. When a slight non-adhesive portion is provided over the entire width direction (or only the central portion) at the crotch side edges of the front and rear pressing sheets 51 and 52, not only does the adhesive not protrude, but this portion is slightly removed from the top sheet. Can float and function as a leak-proof wall.

  If the front and rear presser sheets 51 and 52 are attached separately as in the illustrated embodiment, there is an advantage that the degree of freedom of material selection increases, but there are also disadvantages such as an increase in materials and manufacturing processes. Therefore, the folded portion 20C formed by folding the exterior body 20 on the inner surface of the diaper can be extended to a portion overlapping the interior body 10 to form portions equivalent to the press sheets 51 and 52 described above.

<Explanation of terms in the specification>
The following terms in the specification have the following meanings unless otherwise specified in the specification.
-"Front body" and "rear body" mean the front and rear portions of the pants-type disposable diaper in the front-rear direction center, respectively. Moreover, a crotch part means the front-back direction range containing the center of the front-back direction of a pants type disposable diaper, and when an absorber has a constriction part, it means the front-back direction range of the part which has the said constriction part.
-“Elastic limit elongation” means the elongation of the elastic limit in the expansion / contraction direction (in other words, the state in which the first sheet layer and the second sheet layer are completely expanded), and the length at the elastic limit is the natural length. It is expressed as a percentage when 100% is assumed.
The “area ratio” means the ratio of the target portion to the unit area, and the target portion (for example, the sheet joint portion 40, the stretchable region 80, the non-stretchable region 70, the main stretchable portion, the buffer stretchable portion) in the target region. The total area of the through holes 31 and the vent holes) is divided by the area of the target region and expressed as a percentage. In particular, the “area ratio” in the region having the stretchable structure extends to the elastic limit in the stretchable direction. It means the area ratio of the state. In a form in which a large number of target portions are provided at intervals, it is desirable to set the target region to a size that includes 10 or more target portions and obtain the area ratio.
“Elongation rate” means a value when the natural length is 100%.
・ "Weight" is measured as follows. After the sample or test piece has been pre-dried, it is left in a test room or apparatus in a standard state (test location is temperature 23 ± 1 ° C., relative humidity 50 ± 2%) to a constant weight. Pre-drying refers to making a sample or test piece constant in an environment at a temperature of 100 ° C. In addition, it is not necessary to perform preliminary drying about the fiber whose official moisture content is 0.0%. From the test piece in a constant weight state, a sample plate (100 mm × 100 mm) is used to cut a sample having a size of 100 mm × 100 mm. The weight of the sample is measured, multiplied by 10, and the weight per square meter is calculated and used as the basis weight.
・ "Thickness" of the absorber is a thickness measuring instrument (Peacock, dial thickness gauge large type, model JB (measurement range 0 to 35 mm) or model K-4 (measurement range 0 to 50 mm)) manufactured by Ozaki Mfg. Co., Ltd. Measure the sample and the thickness meter horizontally.
-"Thickness" other than the above is automatically measured using an automatic thickness measuring instrument (KES-G5 handy compression measurement program) under the conditions of load: 0.098 N / cm ² and pressure area: 2 cm ² .
・ "Tensile strength" and "tensile elongation (breaking elongation)" are in accordance with JIS K7127: 1999 "Plastic-Test method for tensile properties-" except that the test piece is rectangular with a width of 35 mm and a length of 80 mm. The initial chuck interval (distance between marked lines) is 50 mm, and the tensile speed is 300 mm / min. As a tensile tester, for example, AOUTGRAPHAGS-G100N manufactured by SHIMADZU can be used.
・ "Elongation stress" means according to JIS K7127: 1999 "Plastics-Test method for tensile properties-" by a tensile test in which the initial chuck interval (distance between marked lines) is 50 mm and the tensile speed is 300 mm / min. This means the tensile stress (N / 35 mm) measured when stretching in the elastic region, and the degree of stretching can be appropriately determined depending on the test object. It is preferable that the test piece has a rectangular shape with a width of 35 mm and a length of 80 mm or more. However, when a test piece with a width of 35 mm cannot be cut out, the test piece is prepared with a width that can be cut out, and the measured value is 35 mm. The value converted to. Even if the target area is small and sufficient specimens cannot be collected, as long as the magnitude of the extension stress is compared, at least a comparison can be made even if the specimens of the same size are used even if they are appropriately small. . As a tensile tester, for example, AOUTGRAPHAGS-G100N manufactured by SHIMADZU can be used.
-"Developed state" means a state where the plate is flattened without contraction or slack.
-Unless otherwise specified, the dimensions of each part mean dimensions in a deployed state, not a natural length state.
・ If there is no description about the environmental conditions in the test and measurement, the test and measurement shall be performed in a test room or equipment in the standard state (test location: temperature 23 ± 1 ° C, relative humidity 50 ± 2%). To do.

  The present invention is applicable to an exterior body of a pants-type disposable diaper.

  DESCRIPTION OF SYMBOLS 10 ... Interior body, 11 ... Top sheet, 12 ... Liquid impervious sheet, 13 ... Absorber, 13N ... Constricted part, 14 ... Packaging sheet, 15 ... Gather nonwoven fabric, 16 ... Gather elastic member, 20 ... Exterior body, 20A ... 1st sheet layer, 20B ... 2nd sheet layer, 20C ... Folded part, 20X ... Film lamination area, 21 ... Side seal part, 23 ... Waist edge part area, 24 ... Waist part elastic member, 25 ... Gutter, 25B ... Leakage prevention ridge, 29 ... edge of leg opening, 30 ... elastic film, 31 ... through hole, 40 ... sheet joint part, 40b ... interval in width direction, 40d ... interval in front and rear direction, 70 ... non-stretchable region, 80 ... stretchable region, 90 ... Wrinkle forming part, 91 ... Adjacent part, B ... Rear body, F ... Front body, L ... Middle part, R ... Leg circumference part, T ... Trunk circumference part.

  The present invention relates to a pants-type disposable diaper.

  The pants-type disposable diaper is an inner body including an outer body that forms at least a waist part of the front body and a waist part of the rear body, and an absorbent body that is attached to the inner surface of the outer body so as to extend from the front body to the rear body. The side opening of the outer body of the front body and the side edge of the outer body of the rear body are joined to form a side seal portion, thereby forming a waist opening and a pair of left and right leg openings. What is common is.

  The outer body of the pants-type disposable diaper is provided with elastic members such as rubber thread in the waist area that is defined as the front-rear direction range (the front-rear direction range from the waist opening to the upper end of the leg opening) with side seals. In general, as an elastic member for that purpose, a method in which a large number of elongated elastic members such as rubber thread are stretched in the longitudinal direction and fixed in a longitudinal direction has been widely used. However, a method of attaching an elastic film in a stretched direction in a stretchable direction has been proposed as having excellent fit as a surface. (For example, refer patent documents 1-4).

  The elastic region of the elastic film is formed by laminating an elastic film between a first sheet layer made of non-woven fabric and a second sheet layer made of non-woven fabric, and the elastic film is stretched in the elastic direction along their surfaces. In this state, the first sheet layer and the second sheet layer are through holes formed in the elastic film with a large number of dot-like sheet joint portions arranged at intervals in the stretching direction and the direction orthogonal thereto. It is formed by joining through. In the natural length state, the stretchable region due to the elastic film is such that, as the elastic film contracts between the sheet bonding portions, the interval between the sheet bonding portions becomes narrower, and the sheet bonding portions between the first sheet layer and the second sheet layer are reduced. A ridge extending in a direction intersecting with the expansion / contraction direction is formed on the surface. On the other hand, when the elastic film is stretched between the sheet joining portions, the gap between the sheet joining portions and the wrinkles in the first sheet layer and the second sheet layer are widened, and the first sheet layer and the second sheet layer are completely separated. Elastic extension is possible up to the deployed state. The stretchable region by the elastic film is excellent in surface fit, and there is no bonding between the first sheet layer and the second sheet layer and the elastic film, and the bonding between the first sheet layer and the second sheet layer is also possible. Since there are very few, it is very flexible, and the through-hole of an elastic film has the advantage that it contributes also to air permeability improvement.

  In a pants-type disposable diaper, when a stretchable structure using an elastic film is adopted for the exterior body, it is desirable to form a stretchable region as wide as possible with the same elastic film in order to simplify the structure and reduce material costs. . However, the elastic region of the elastic film usually cannot change the tightening force in the direction orthogonal to the elastic direction. In addition, if the elastic film is thinned to ensure flexibility, the elastic film becomes weak. If anything, the structure is unsuitable for exerting a strong clamping force. Furthermore, there is a limit to what the tightening force can be changed to some extent due to the change in the area ratio of the sheet joint portion (see, for example, Patent Document 4). For this reason, if a stretchable structure with the same elastic film is provided over the leg surrounding portion along the edge of the leg opening and the subsequent portion where a relatively strong tightening force is desired, the tightening force of the edge portion is insufficient. As a result, there was a risk that the leakage prevention property would be reduced.

  In addition, it has also been proposed to add an elongated elastic member such as rubber thread along the leg circumference to the leg circumference portion having the elastic film (see, for example, Patent Document 2). Although this technique is effective, the manufacturing process is complicated because the elongated elastic member is provided in the portion having the elastic film, and the product structure is also complicated. Therefore, it is desired to improve leakage prevention by another approach.

JP-T-2004-532758 Special table 2009-536845 International Publication No. 2008/126708 JP 2017-64226 A

  Therefore, the main problem of the present invention is to improve the leakage prevention performance of the leg-surrounding part by a simple change in the stretchable structure using the elastic film having the same leg-surrounding part and the subsequent part.

The pants type disposable diaper which solved the above-mentioned subject is as follows.
<First aspect>
In the pants-type disposable diaper in which the side edge of the front body and the side edge of the back body are joined on both sides in the width direction to form a waist opening and a leg opening,
An elastic film is laminated between the first sheet layer positioned on the skin side of the wearer and the second sheet layer positioned on the outer side of the leg surrounding portion and the subsequent portion along the edge of the leg opening. The first sheet layer and the second sheet layer have a film lamination region bonded directly or indirectly by a number of sheet bonding portions arranged at intervals,
The leg periphery portion in the film lamination region has a leg periphery expansion / contraction region that is contracted in the width direction and expandable in the width direction by contraction of the elastic film,
In the leg-surrounding stretchable region, a ridge-forming portion where the first sheet layer, the elastic film, and the second sheet layer are not joined extends in the leg-surrounding direction while being spaced from the edge of the leg opening. And
The adjacent parts facing each other across the ridge-forming part are parts where the first sheet layer and the second sheet layer are joined by the sheet joining part,
The size of the flange forming portion in the direction orthogonal to the edge of the leg opening is larger than the width-direction interval of the sheet bonding portion and the front-rear direction interval of the sheet bonding portion in the adjacent portion,
A pants-type disposable diaper characterized by that.

(Function and effect)
In this aspect, the leakage preventing ridge due to the shrinkage of the first sheet layer is formed on the skin side of the leg-surrounding stretchable region with the elastic film being contracted to some extent. Here, when the size of the ridge forming portion in the direction orthogonal to the edge of the leg opening is larger than the interval in the width direction of the sheet joint portion in the adjacent portion and the interval in the front-rear direction of the sheet joint portion, A high (large) leakage prevention ridge is formed, which becomes a weir extending in the direction around the leg. Therefore, according to this aspect, the leak-proof ridge that bulges to the skin side by a simple device that simply provides the above-described heel-forming portion (non-joined portion) and adjacent portion (joined portion) in the leg-stretchable region is a weir. Thus, it extends along the leg circumference, and the leakage prevention performance of the leg circumference portion is improved.

<Second aspect>
The pants-type disposable diaper according to the first aspect, wherein the second sheet layer is bonded to the elastic film via a hot melt adhesive at least in the heel-forming portion.

(Function and effect)
If the second sheet layer is not bonded to the elastic film at the wrinkle forming portion, not only the first sheet layer (skin side) but also the second sheet layer (outside) is formed with high wrinkles, so it is neat Appearance does not become. On the other hand, when the second sheet layer is bonded to the elastic film at the wrinkle forming portion as in this aspect, a high leakage preventing wrinkle is formed on the first sheet layer (skin side). Since the sheet layer (outside) is formed with low and fine wrinkles, it has a clean appearance while improving leakage prevention.

<Third Aspect>
The pants-type disposable diaper according to the first or second aspect, wherein the size of the heel-forming portion in the direction orthogonal to the edge of the leg opening is gradually or continuously enlarged as it approaches the crotch side.

(Function and effect)
As the leg circumference part is closer to the crotch side, leakage prevention becomes more important. Therefore, by changing the size of the heel-forming part in the direction perpendicular to the edge of the leg opening as in this aspect, the leg circumference part is formed on the leg circumference part. It is preferable to increase the height of the leakage prevention ridge as it approaches the crotch side.

<Fourth aspect>
The pants-type disposable diaper according to any one of the first to third aspects, wherein a plurality of the heel-forming portions are provided at intervals so as not to cross each other.

(Function and effect)
Since the leakage prevention ridge formed on the first sheet layer is flexible and deformable, there is a risk that a portion having a low damming action may be formed due to the formation of irregularities, etc., and only one piece has leakage prevention properties May be insufficient. Therefore, it is preferable to provide a plurality of wrinkle forming portions as in this embodiment.

<Fifth aspect>
The size of the flange forming portion in the direction orthogonal to the edge of the leg opening is 2 to 6 mm, the interval in the width direction of the sheet joint portion in the adjacent portion is 1 to 3 mm, and the sheet joint portion in the adjacent portion The front-rear direction interval is 0.5-2 mm,
The dimension of the flange forming portion in the direction orthogonal to the edge of the leg opening is 2 to 6 times the larger one of the width direction interval of the sheet joint portion and the front-rear direction interval of the sheet joint portion in the adjacent portion. ,
The underpants type disposable diaper of any one aspect of the 1st-4th.

(Function and effect)
The size of the ridge-forming portion and the interval in the width direction of the sheet joining portion in the direction orthogonal to the edge of the leg opening are not particularly limited, but in the normal case, it is preferably within the range described in this section.

  As described above, according to the present invention, in the stretchable structure using the same elastic film in the leg periphery portion and the subsequent portion, there are advantages such as being able to improve the leakage prevention performance of the leg periphery portion by a simple change. Brought about.

It is a top view (inner surface side) of the underpants type disposable diaper of a deployment state. It is a top view (outer surface side) of the underpants type disposable diaper of a deployment state. It is a top view which shows only the principal part of the underpants type disposable diaper of an unfolded state. (A) is CC sectional drawing of FIG. 1, (b) is EE sectional drawing of FIG. It is AA sectional drawing of FIG. It is BB sectional drawing of FIG. (A) is a principal part top view of an expansion-contraction area | region, (b) is DD sectional drawing of (a), (c) is sectional drawing in a mounting state, (d) is sectional drawing in a natural length state. (A) Trace diagram of micrograph from plane direction of sample stretch region, (b) Trace diagram of high magnification micrograph from plane direction, (c) Trace diagram of high magnification micrograph from perspective direction. (A) is a principal part top view of an expansion-contraction area | region, (b) is DD sectional drawing of (a), (c) is sectional drawing in a mounting state, (d) is sectional drawing in a natural length state. (A) Trace diagram of micrograph from plane direction of sample stretch region, (b) Trace diagram of high magnification micrograph from plane direction, (c) Trace diagram of high magnification micrograph from perspective direction. (A) is a principal part top view of a non-expandable area | region, (b) is DD sectional drawing of (a), (c) is sectional drawing in a mounting state, (d) is sectional drawing in a natural length state. It is the trace figure of the photograph of the non-stretching area | region of a sample. It is a principal part enlarged plan view of a non-expandable region. (A) Cross-sectional view in the unfolded state in the direction across the ridge-forming portion, (b) is a cross-sectional view in the mounted state, and (c) is a cross-sectional view in the natural length state. It is a top view (outer surface side) of the underpants type disposable diaper of a deployment state. (A) is CC sectional drawing of FIG. 15, (b) is EE sectional drawing of FIG. It is sectional drawing which shows roughly the principal part cross section of the exterior body extended to some extent. It is sectional drawing which shows roughly the principal part cross section of the exterior body extended to some extent. (A) Trace figure of the plane photograph of the sheet | seat junction part formed with the 1st welding form, (b) Trace figure of the plane photograph of the sheet | seat junction part formed with the 3rd welding form. It is the schematic of an ultrasonic sealing apparatus. It is a top view which shows the various arrangement | sequence examples of a sheet | seat junction part. (A) Cross-sectional view in the unfolded state in the direction across the ridge-forming portion, (b) is a cross-sectional view in the mounted state, and (c) is a cross-sectional view in the natural length state.

Hereinafter, an embodiment of the present invention will be described in detail with reference to the accompanying drawings. In addition, the dotted pattern part in sectional drawing has shown joining means, such as a hot-melt-adhesive.
1 to 6 show a pants-type disposable diaper. This pants-type disposable diaper (hereinafter also simply referred to as a diaper) is fixed to and integrated with an exterior body 20 that forms at least a waist part of the front body F and a waist part of the back body B. The interior body 10 has an absorbent body 13 interposed between a liquid-permeable top sheet 11 and a liquid-impermeable sheet 12. In manufacturing, after the back surface of the interior body 10 is joined to the inner surface (upper surface) of the exterior body 20 by a joining means such as a hot melt adhesive, the interior body 10 and the exterior body 20 are the front body F and the back body B. Are folded at the center in the front-rear direction (longitudinal direction), and the side seal portions 21 are formed by joining both sides thereof by heat welding or hot melt adhesive, thereby forming a waist opening and a pair of left and right A pants-type disposable diaper in which leg openings are formed.

(Structural example of interior body)
As shown in FIGS. 4 to 6, the inner body 10 has a structure in which an absorber 13 is interposed between a top sheet 11 and a liquid-impermeable sheet 12 made of polyethylene or the like. The excretory fluid that has passed through the sheet 11 is absorbed and retained. Although the planar shape of the interior body 10 is not particularly limited, it is generally a rectangular shape as shown in FIG.

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

  As the liquid-impermeable sheet 12 covering the back side (non-skin contact side) of the absorbent body 13, a liquid-impermeable plastic sheet such as polyethylene or polypropylene is used, but in recent years, it has moisture permeability from the viewpoint of preventing stuffiness. Are preferably used. This water-impervious and moisture-permeable sheet is a microporous sheet obtained by, for example, melt-kneading an inorganic filler in an olefin resin such as polyethylene or polypropylene to form a sheet, and then stretching in a uniaxial or biaxial direction. is there.

  Absorbent body 13 is a known one, for example, a pulp fiber stack, a filament aggregate such as cellulose acetate, or a non-woven fabric, mixed with a superabsorbent polymer as necessary, fixed, etc. Can be used. The absorbent body 13 can be packaged with a wrapping sheet 14 having liquid permeability and liquid retention, such as crepe paper, if necessary, for holding the shape and polymer.

  The shape of the absorber 13 is formed in a substantially hourglass shape having a narrowed portion 13N having a narrower width than the front and rear sides in the crotch portion, but may be an appropriate shape such as a rectangular shape. Although the size of the constricted portion 13N can be determined as appropriate, the length in the front-rear direction of the constricted portion 13N can be about 20 to 50% of the total length of the diaper, and the width of the narrowest portion is 40% of the total width of the absorber 13. It can be about -60%. In the case of having such a constricted portion 13N, if the planar shape of the interior body 10 is substantially rectangular, the remainder of the interior body 10 that does not have the absorber 13 in the portion corresponding to the constricted portion 13N of the absorber 13 A part is formed.

  A solid gather BS that fits around the legs is formed on both sides of the interior body 10. As shown in FIGS. 5 and 6, the three-dimensional gather BS includes a fixed portion fixed to a side portion on the back surface of the interior body, and a side portion on the surface of the interior body from the fixed portion to the side of the interior body. The body part that extends to the front, the front and rear ends of the body part in a lying state, and the lying part that is fixed to the side of the surface of the interior body, and the freedom part that is formed with this lying part being unfixed The part is formed of a gathered nonwoven fabric 15 that is turned into a double sheet by folding.

  Further, between the double sheets, an elongated gather elastic member 16 is disposed at the tip of the free part. The gather elastic member 16 is for forming a three-dimensional gather BS by raising a free part by elastic stretching force as shown by a two-dot chain line in FIG. 5 in the product state.

  The liquid-impermeable sheet 12 is folded back together with the top sheet 11 on both sides in the width direction of the absorber 13. As this liquid-impermeable sheet 12, it is desirable to use an opaque sheet so that brown color such as defecation and urine does not appear. As the opacification, a plastic film and a pigment and filler such as calcium carbonate, titanium oxide, zinc oxide, white carbon, clay, talc and barium sulfate are preferably used.

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

In the same manner as the top sheet 11, the material fiber constituting the gathered nonwoven fabric 15 is not only synthetic fibers such as olefins such as polyethylene or polypropylene, polyesters, and amides, but also regenerated fibers such as rayon and cupra, and natural fibers such as cotton. Nonwoven fabric obtained by an appropriate processing method such as a spun bond method, a thermal bond method, a melt blown method, a needle punch method, etc. can be used. It is better to use a nonwoven fabric that suppresses and has excellent air permeability. Furthermore, for the gathered nonwoven fabric 15, silicone, paraffin metal, alkylchromic chloride water repellent, etc. are used to prevent urine transmission and the like, as well as to prevent fogging and to improve skin feel (dry feeling). It is desirable to use a water-repellent non-woven fabric coated with.

  As shown in FIG. 3, the back surface of the interior body 10 is fixed to the inner surface of the exterior body 20 with a hot melt adhesive or the like in the inner / outer fixing area 10 </ b> B (shaded area). This inner / outer fixed region 10 </ b> B extends across the front and rear sides of the non-absorbent body side portion 17 with a width extending from one non-absorbent body side portion 17 to the other non-absorbent body side portion 17. The side edge of the inner / outer fixing region 10B is preferably located laterally from the middle in the width direction of the non-absorbent body side portion 17, and in particular, the exterior body over almost the whole width direction of the interior body 10 and almost the whole front and rear direction. More preferably, it is fixed to 20.

(External body structure example)
The exterior body 20 is an intermediate portion that is a front-rear direction range between a waistline portion T that is a front-rear direction range corresponding to the side seal portion 21, and a waistline portion T of the front body F and a waistline portion T of the rear body B. L. And in the exterior body 20 of the illustrated form, the first sheet layer 20A located on the skin side of the wearer, as shown in FIG. 2 and FIGS. More than that, the elastic film 30 is laminated between the second sheet layers 20B, and as shown in FIG. 7, the first sheet layers 20A and the second sheet layers 20B are arranged in a large number at intervals. It has the film lamination | stacking area | region 20X by which the expansion-contraction direction was made into the width direction joined through the through-hole 31 which penetrates the elastic film 30 in the sheet | seat junction part 40. The first sheet layer 20 </ b> A and the second sheet layer 20 </ b> B may be indirectly joined through the elastic film 30 instead of through the through hole 31 of the elastic film 30. As for the planar shape of the exterior body 20, the concave portions at both side edges of the intermediate portion L are the edges 29 of the leg openings, and the shape is like an hourglass as a whole. The exterior body 20 may be divided into two parts in the front-rear direction so that both are separated in the front-rear direction at the crotch part.

  The form shown in FIGS. 1 and 2 is a form in which the film lamination region 20X extends to the waist end region 23, but the tightening of the waist end region 23 is insufficient only by expansion and contraction by the film lamination region 20X. As shown in FIGS. 15 and 16, the elastic structure is formed by a conventional elongated waist elastic member 24 without providing (or providing) the film lamination region 20 </ b> X in the waist end region 23 as shown in FIGS. 15 and 16. 20X can also be provided. The waist elastic member 24 is an elongated elastic member such as a plurality of thread rubbers arranged at intervals in the front-rear direction, and gives an elastic force so as to tighten around the body torso. The waist elastic members 24 are not arranged substantially as a single bundle with a close interval, but with a spacing of about 3 to 8 mm so as to form a predetermined stretch zone, preferably three or more, preferably Five or more are arranged. The stretch rate at the time of fixing the waist elastic member 24 can be determined as appropriate, but can be about 230 to 320% in the case of a normal adult. For the waist elastic member 24, thread rubber is used in the illustrated example, but other elongated elastic members such as flat rubber may be used.

  As other forms, although not shown in the figure, the intermediate part L between the waist part T of the front body F and the waist part T of the back body B is not provided with the film lamination region 20X, or the front body F The stretchable structure 20X is continuously provided in the front-rear direction from the inside of the waist part T to the inside of the waist part T of the back body B through the intermediate part L, or the film is laminated only on either the front body F or the back body B It is also possible to provide the region 20X.

  Although the shape in the natural length state of each sheet | seat junction part 40 and the through-hole 31 can be determined suitably, a perfect circle (refer FIG. 7, FIG. 8), an ellipse, a triangle, a rectangle (refer FIG. 9-12). ), Rhombus (see FIG. 13B), etc., or convex lens shape (see FIG. 13A), concave lens shape (see FIG. 13C), star shape, cloud shape, etc. be able to. The dimensions of the individual sheet joints are not particularly limited, but the maximum length is preferably 0.5 to 3.0 mm, particularly preferably 0.7 to 1.1 mm, and the maximum width 40x is 0.1 to 3.0 mm. In particular, when the shape is long in the direction orthogonal to the expansion and contraction direction, the thickness is preferably 0.1 to 1.1 mm.

The size of each sheet bonding portion 40 may be determined as appropriate. However, if the size is too large, the hardness of the sheet bonding portion 40 has an effect on the touch. If the size is too small, the bonding area is small and the materials are sufficiently bonded to each other. Since it becomes impossible, it is preferable that the area of each sheet | seat junction part 40 shall be about 0.14-3.5 mm < ² > normally. The area of the opening of each through hole 31 may be equal to or greater than the sheet joint portion because the sheet joint portion is formed through the through hole 31, but is about 1 to 1.5 times the area of the sheet joint portion. It is preferable. In addition, the area of the opening of the through-hole 31 means a value in a state of being integrated with the first sheet layer 20A and the second sheet layer 20B, not in the state of the elastic film 30 alone, and in a natural length state. When the area of the opening 31 is not uniform in the thickness direction, such as when the elastic film 30 is different from the front and back, it means the minimum value.

  The planar arrangement of the sheet joint portion 40 and the through-holes 31 can be determined as appropriate, but a regularly repeated planar arrangement is preferable, and an oblique lattice shape as shown in FIG. Hexagonal lattice shape as shown (these are also called zigzag shapes), square lattice shape as shown in FIG. 21 (c), rectangular lattice shape as shown in FIG. 21 (d), as shown in FIG. 21 (e) Parallel body lattice (as shown in the figure, two groups are provided so that a large number of groups of parallel diagonal rows intersect each other), etc. (these are inclined at an angle of less than 90 degrees with respect to the expansion and contraction direction And a group of sheet joint portions 40 (group unit arrangement may be regular or irregular, and may be a pattern or a letter shape) is regularly repeated. You can also

  The first sheet layer 20 </ b> A and the second sheet layer 20 </ b> B in the sheet bonding portion 40 are bonded through the through-hole 31 formed in the elastic film 30. In this case, it is desirable that the elastic film 30 is not bonded at least except between the first sheet layer 20A and the second sheet layer 20B in the sheet bonding portion 40.

  The joining means of the first sheet layer 20A and the second sheet layer 20B in the sheet joining portion 40 is not particularly limited. For example, the joining of the first sheet layer 20A and the second sheet layer 20B in the joining portion 40 may be performed by a hot melt adhesive, or may be performed by a joining means such as heat sealing or ultrasonic sealing.

  When the first sheet layer 20 </ b> A and the second sheet layer 20 </ b> B are bonded through the through hole 31 in the sheet bonding portion 40, the form in which the sheet bonding portion 40 is formed by material welding is the first sheet layer 20 </ b> A in the sheet bonding portion 40. And a first welding form in which the first sheet layer 20A and the second sheet layer 20B are joined only by the majority or part of the molten solidified material 20m of at least one of the second sheet layer 20B (see FIG. 17A), The second welding mode in which the first sheet layer 20A and the second sheet layer 20B are joined by all or most of the elastic film 30 in the sheet joining portion 40 or only a part of the melt-solidified material 30m (see FIG. 17B). , And a third welding form in which both of these are combined (see FIG. 17 (c)), but the second and third welding forms are preferable. Particularly preferably, the first sheet layer is composed of a part of the melt-solidified material 20m of the first sheet layer 20A and the second sheet layer 20B and the whole or most of the melt-solidified material 30m of the elastic film 30 in the sheet joint portion 40. 20A and the second sheet layer 20B are joined together. In the third welding mode shown in FIG. 19B, the elastic film 30 appears in white between the melt-solidified products 20m of the fibers of the first sheet layer 20A or the second sheet layer 20B shown in black. In the first welding form shown in FIG. 19A, an elastic film is formed between the melt-solidified products 20m of the fibers of the first sheet layer 20A or the second sheet layer 20B. A melt-solidified product is not observed (the white part is the boundary between the fiber melt-solidified product 20 m and the diffuse reflection of the fiber melt-solidified product 20 m).

  As in the first adhesive form and the third adhesive form, the first sheet layer 20A and the second sheet 20A and the second sheet 20A and the second sheet layer 20B are used by using at least one of the first sheet layer 20A and the second sheet layer 20B as the adhesive. When joining the sheet layer 20B, it is preferable not to melt part of the first sheet layer 20A and the second sheet layer 20B because the sheet joining part 40 does not harden. Note that when the first sheet layer 20A and the second sheet layer 20B are non-woven fabrics, a part of the first sheet layer 20A and the second sheet layer 20B does not melt. The composite fiber contains not only the core but also the central part of the single component fiber), but the surrounding part (including not only the sheath but also the surface part of the single component fiber of the composite fiber) melts, The fibers do not melt at all, but the remaining fibers either completely melt or the core remains but the surrounding portion includes a molten form.

  When the first sheet layer 20A and the second sheet layer 20B are joined using the melt-solidified material 30m of the elastic film 30 as an adhesive as in the second welding form and the third welding form, the peel strength becomes high. In the second welding mode, the first sheet layer 20A and the second sheet layer 20B have a melting point that is higher than the melting point of the elastic film 30 and the heating temperature when forming the sheet joint 40. In addition, the elastic film 30 is sandwiched between the second sheet layers 20 </ b> B, the portion to be the sheet bonding portion 40 is pressurized and heated, and only the elastic film 30 is melted. On the other hand, in the third welding mode, the first sheet layer 20A and the second sheet layer 20B are between the first sheet layer 20A and the second sheet layer 20B under the condition that the melting point of at least one of the first sheet layer 20A and the second sheet layer 20B is higher than the melting point of the elastic film 30. It can be manufactured by sandwiching the elastic film 30, pressurizing and heating a portion to be the sheet bonding portion 40, and melting at least one of the first sheet layer 20 </ b> A and the second sheet layer 20 </ b> B and the elastic film 30. From such a viewpoint, the melting point of the elastic film 30 is preferably about 80 to 145 ° C., and the melting points of the first sheet layer 20A and the second sheet layer 20B are about 85 to 190 ° C., particularly about 150 to 190 ° C. The difference between the melting points of the first sheet layer 20A and the second sheet layer 20B and the melting point of the elastic film 30 is preferably about 60 to 90 ° C. Moreover, it is preferable that heating temperature shall be about 100-150 degreeC.

  In the second welding mode and the third welding mode, when the first sheet layer 20A and the second sheet layer 20B are non-woven fabrics, the melt-solidified product 30m of the elastic film 30 is a sheet joint portion as shown in FIG. 40 may penetrate between the fibers in the entire thickness direction of the first sheet layer 20A and the second sheet layer 20B, but as shown in FIGS. 17 (b) (c) and 18 (a), it is intermediate in the thickness direction. The form that penetrates between the fibers up to or the form that hardly penetrates between the fibers of the first sheet layer 20A and the second sheet layer 20B as shown in FIG. It will be a thing.

  FIG. 20 shows an example of an ultrasonic sealing device suitable for forming the second welding form and the third welding form. In this ultrasonic sealing apparatus, when the sheet bonding portion 40 is formed, the first sheet layer 20A, between the anvil roll 60 and the ultrasonic horn 61, each having a projection 60a formed in the pattern of the sheet bonding portion 40 on the outer surface, The elastic film 30 and the second sheet layer 20B are fed. At this time, for example, the feeding driving speed of the upstream elastic film 30 by the feeding driving roll 63 and the nip roll 62 is made slower than the feeding speed after the anvil roll 60 and the ultrasonic horn 61, thereby the feeding driving roll 63 and the nip roll 62. The elastic film 30 is stretched in the MD direction (machine direction, flow direction) to a predetermined stretch rate through the path from the nip position due to the above to the seal position due to the anvil roll 60 and the ultrasonic horn 61. The stretch rate of the elastic film 30 can be set by selecting the speed difference between the anvil roll 60 and the feed drive roll 63, and can be set to about 300% to 500%, for example. The first sheet layer 20 </ b> A, the elastic film 30, and the second sheet layer 20 </ b> B fed between the anvil roll 60 and the ultrasonic horn 61 are stacked in this order, and the protrusion 60 a and the ultrasonic horn 61 are While being pressurized, the ultrasonic horn 61 is heated by ultrasonic vibration energy to melt only the elastic film 30 or at least one of the first sheet layer 20A and the second sheet layer 20B and the elastic film 30 are melted. By doing so, the first sheet layer 20 </ b> A and the second sheet layer 20 </ b> B are joined through the through-hole 31 at the same time as the through-hole 31 is formed in the elastic film 30. Therefore, in this case, by selecting the size, shape, separation interval, arrangement pattern in the roll length direction and roll circumferential direction, etc., of the projections 60a of the anvil roll 60, the area ratio of the sheet joining portion 40 is selected. Can do.

  The reason why the through hole 31 is formed is not necessarily clear, but it is considered that the hole corresponding to the protrusion 60a of the anvil roll 60 in the elastic film 30 is melted and separated from the surroundings. At this time, a portion of the elastic film 30 between the through holes 31 adjacent to each other in the expansion / contraction direction is expanded / contracted by the through holes 31 as shown in FIGS. 7 (a), 9 (a), and 11 (a). Since it is cut from both sides and loses the support on both sides in the contraction direction, the central side in the direction orthogonal to the expansion / contraction direction is balanced with the central side in the expansion / contraction direction within a range that can maintain continuity in the direction orthogonal to the contraction direction. The through hole 31 expands in the expansion / contraction direction. And when the sheet | seat junction part 40 is formed in the pattern in which the part which the elastic film 30 continues linearly along the expansion-contraction direction like the expansion-contraction area | region 80 mentioned later is shown in FIG.7 (d) and FIG.9 (d). Thus, when contracting to a natural length state by cutting into individual products, the length in the expansion / contraction direction of the enlarged portion of the through hole 31 creates a gap between the through hole 31 and the sheet joining portion 40. It will shrink until it runs out. On the other hand, when the sheet joining portion 40 is formed in a pattern in which the elastic film 30 does not have a linearly continuous portion along the stretching direction as in a non-stretchable region 70 described later, as shown in FIG. Since it hardly shrinks when it is shrunk to a natural length state by cutting into a product or the like, a large gap is left between the through hole 31 and the sheet bonding portion 40.

The constituent material of the first sheet layer 20A and the second sheet layer 20B can be used without particular limitation as long as it is a sheet, but it is preferable to use a nonwoven fabric from the viewpoint of air permeability and flexibility. The nonwoven fabric is not particularly limited as to what the raw fiber is. For example, synthetic fibers such as olefins such as polyethylene and polypropylene, polyesters and polyamides, recycled fibers such as rayon and cupra, natural fibers such as cotton, and mixed fibers and composite fibers using two or more of them. Etc. can be illustrated. Furthermore, the nonwoven fabric may be manufactured by any processing. Examples of the processing method include known methods such as a spunlace method, a spunbond method, a thermal bond method, a melt blown method, a needle punch method, an air through method, and a point bond method. When using a nonwoven fabric, the basis weight is preferably about 12 to ²⁰ g / m ² . Moreover, a part or all of the first sheet layer 20A and the second sheet layer 20B may be a pair of layers in which one material is folded and faced. For example, as shown in the figure, in the waist end region 23, the constituent material located outside is the second sheet layer 20B, and the folded portion 20C that is folded back to the inner surface side at the waist opening edge is the first sheet layer 20A. In addition, the elastic film 30 is interposed therebetween, and in the other portions, the constituent material positioned inside is the first sheet layer 20A, and the constituent material positioned outside is the second sheet layer 20B, and the elastic film 30 is interposed therebetween. Can be interposed. Of course, the constituent material of the first sheet layer 20A and the constituent material of the second sheet layer 20B are individually provided over the entire front-rear direction, and the constituent material of the first sheet layer 20A and the second sheet layer are not folded back. The elastic film 30 can also be interposed between the constituent materials of 20B.

  The elastic film 30 is not particularly limited, and as long as it is a thermoplastic resin film having elasticity per se, a film having a large number of holes and slits for ventilation can also be used. . In particular, the tensile strength in the width direction (stretching direction, MD direction) is 8 to 25 N / 35 mm, the tensile strength in the front-rear direction (direction perpendicular to the stretching direction, CD direction) is 5 to 20 N / 35 mm, and the tensile elongation in the width direction. Is preferably 450 to 1050%, and the elastic film 30 having a tensile elongation in the front-rear direction of 450 to 1400%. Although the thickness of the elastic film 30 is not specifically limited, It is preferable that it is about 20-40 micrometers.

(Stretchable area and non-stretchable area)
The film lamination region 20 </ b> X in the exterior body 20 includes a non-stretchable region 70 and a stretchable region 80 that can be stretched in the width direction, and the stretchable region 80 is located in a leg-around portion R along the edge 29 of the leg opening. It has an elastic area around the legs. The arrangement of the stretchable region 80 and the non-stretchable region 70 can be changed as appropriate. In the case of the exterior body 20 of the pants-type disposable diaper as in the present embodiment, the portion overlapping the absorber 13 is an area that does not need to be expanded and contracted, and therefore, part or all of the portion overlapping the absorber 13 as illustrated. It is preferable to make the non-stretchable region 70 (desirably including almost the entire inner and outer fixed region 10B). Of course, the non-stretchable region 70 can be provided from the region overlapping with the absorber 13 to the region not overlapping with the absorber 13 positioned in the width direction or the front-rear direction, and the non-stretchable region 70 is provided only in the region not overlapping with the absorber 13. It can also be provided.

  Moreover, in order to extend the heel forming portion 90 described later to the crotch side than the illustrated example, the width of the non-stretchable region 70 may be narrowed, the crotch width of the exterior body 20 may be widened, or both. it can.

(Elastic area)
In the stretchable region 80, the elastic film 30 has a portion 32 linearly continuous along the width direction, and is contracted in the width direction by the contraction force of the elastic film 30, and can be expanded in the width direction. It has become. More specifically, in a state where the elastic film 30 is extended in the width direction, the through-holes 31 of the elastic film 30 are formed at intervals in the width direction and in the front-rear direction (direction orthogonal to the expansion / contraction direction) orthogonal thereto. The first sheet layer 20A and the second sheet layer 20B are joined together to form a large number of sheet joint portions 40, thereby forming the film lamination region 20X including both the stretch region 80 and the non-stretch region 70, In the stretchable region 80, such stretchability can be imparted by arranging the through holes 31 so that the elastic film 30 has a linearly continuous portion along the width direction.

  In the stretchable region 80, in the natural length state, as shown in FIGS. 7D and 9D, the first sheet layer 20A and the second sheet layer 20B between the sheet joining portions 40 swell in a direction away from each other. Thus, a collar 25 extending in the front-rear direction is formed. As shown in FIGS. 7 (c) and 9 (c), the collar 25 is stretched but remains even in a mounted state that extends to some extent in the width direction. Yes. Further, as illustrated, the first sheet layer 20A and the second sheet layer 20B are not joined to the elastic film 30 except at least between the first sheet layer 20A and the second sheet layer 20B in the sheet joining portion 40. FIGS. 7 (c) and 9 (c) assuming the mounted state, and FIGS. 7 (a) (b) and 9 (a) (9) assuming the expanded state of the first sheet layer 20A and the second sheet layer 20B. As can be seen from b), in these states, a gap is formed between the through hole 31 in the elastic film 30 and the sheet joint portion 40, and the material of the elastic film 30 is a non-porous film or sheet. However, air permeability is added by this gap. Further, in the natural length state shown in FIG. 7D and FIG. 9D, the through hole 31 is squeezed due to the contraction of the elastic film 30, and almost no gap is formed between the through hole 31 and the sheet joining portion 40. Not. In addition, the state of the collar 25 in the mounted state and the natural length state also appears in the trace diagrams of the sample photographs in FIGS. 8 and 10.

  The elastic limit elongation in the width direction of the stretchable region 80 is desirably 200% or more (preferably 265 to 295%). The elastic limit elongation of the stretchable region 80 is substantially determined by the stretch rate of the elastic film 30 at the time of manufacture, but based on this, it is lowered by a factor that inhibits shrinkage in the width direction. The main factor of such inhibition is the ratio of the length 40x of the sheet joint portion 40 per unit length in the width direction, and the elastic limit elongation decreases as the ratio increases. In a normal case, the length 40x of the sheet bonding portion 40 has a correlation with the area ratio of the sheet bonding portion 40, so that the elastic limit elongation of the stretchable region 80 can be adjusted by the area ratio of the sheet bonding portion 40.

The elongation stress of the stretchable region 80 can be adjusted mainly by the sum of the widths 32w of the portions 32 where the elastic film 30 continues linearly along the width direction. The width 32w of the portion 32 in which the elastic film 30 is linearly continuous along the width direction is equal to the interval 31d in the front-rear direction of the through-holes 31 in contact with both side edges of the continuous portion 32. 31d is when the length 31y of the through-hole 31 in the front-rear direction is equal to the length 40y of the sheet-joint portion 40 in the front-rear direction (when the above-described simultaneous formation method of the through-hole 31 and the sheet joint 40 is employed, etc.) ) Is equal to the interval 40d in the front-rear direction of the sheet joining portion 40 in contact with both side edges of the continuous portion. Therefore, in this case, the extension stress of the stretchable region 80 can be adjusted by the ratio of the length 40y of the sheet joint portion 40 per unit length in the front-rear direction. Since the length 40y has a correlation with the area ratio of the sheet bonding portion 40, the length of the sheet bonding portion 40 can be adjusted by the area ratio of the sheet bonding portion 40. The elongation stress of the expansion / contraction region 80 can be determined based on the elongation stress when it is expanded to 50% of the elastic limit.

The area ratio of the sheet bonding portion 40 and the area of each sheet bonding portion 40 in the stretchable region 80 can be determined as appropriate, but in the normal case, it is preferably within the following range.
Area of sheet joint 40: 0.14 to 3.5 mm ² (particularly 0.14 to 1.0 mm ² )
Area ratio of sheet joint portion 40: 1.8 to 19.1% (particularly 1.8 to 10.6%)

  As described above, since the elastic limit elongation and the extension stress of the stretchable region 80 can be adjusted by the area of the sheet joint portion 40, a plurality of regions having different area ratios of the sheet joint portion 40 in the stretchable region 80 as shown in FIG. The fitting property can be changed according to the part. In the form shown in FIG. 15, the area 81 extending in the oblique direction along the base of the leg in the front body F and the edge area 82 of the leg opening have a higher area ratio of the sheet joint portion 40 than the other areas. Therefore, the extensional stress is weak and the region expands and contracts flexibly. In addition, the iliac facing region 83 and the edge region 82 of the leg opening in the back body B also have a higher area ratio of the sheet joint portion 40 than the other regions, and therefore the extension stress is weak and the region expands and contracts flexibly. It has become.

(Non-stretchable area)
On the other hand, the non-stretchable region 70 is a region that does not have a linearly continuous portion along the width direction due to the presence of the through hole 31, although the elastic film 30 is continuous in the width direction. Therefore, in a state where the elastic film 30 is extended in the width direction, the first sheet layer 20 </ b> A and the second sheet layer are spaced via the through-holes 31 of the elastic film 30 with an interval in the width direction and the front-rear direction orthogonal thereto. Even if the entire film laminated region 20X including both the stretchable region 80 and the non-stretchable region 70 is formed by joining 20B and forming a large number of sheet joint portions 40, as shown in FIG. 70, since the elastic film 30 is not linearly continuous along the width direction, the contraction force of the elastic film 30 hardly acts on the first sheet layer 20A and the second sheet layer 20B, and the stretchability is almost lost. The elastic limit elongation is close to 100%. In such a non-stretchable region 70, the first sheet layer 20 </ b> A and the second sheet layer 20 </ b> B are joined by a large number of sheet joining portions 40 arranged at intervals, and the sheet joining portion 40 is not continuous. Therefore, a decrease in flexibility is prevented. In other words, the stretchable region 80 and the non-stretchable region 70 can be formed by the presence or absence of a portion where the elastic film 30 does not continue linearly along the width direction. Also, the continuity of the elastic film 30 remains in the non-stretchable region 70, and as can be seen from the trace diagram of the sample photograph shown in FIG. Since it is not formed, it looks very good and the air permeability in the thickness direction by the through hole 31 is ensured. The non-stretchable region 70 preferably has an elastic limit elongation in the width direction of 120% or less (preferably 110% or less, more preferably 100%).

  Although the arrangement pattern of the through holes 31 in the elastic film 30 in the non-stretchable region 70 can be determined as appropriate, it is arranged in a staggered manner as shown in FIG. If the pattern is shorter than the length 31y in the direction, the linear continuity in the width direction can be almost completely eliminated while maintaining the continuity of the elastic film 30, and the appearance is preferable as shown in FIG. In this case, it is more preferable that the center interval 31f in the width direction of the through hole 31 is shorter than the length 31x of the through hole 31 in the width direction.

  In a normal case, in particular, when the elastic film 30 has a stretching stress of 4.0 to 12 N / 35 mm when stretched four times in the width direction, the non-stretchable region 70 is stretched to the elastic limit in the width direction. The center distance 31e in the front-rear direction of the through-hole 31 is 0.4 to 2.7 mm, and the length 31y in the front-rear direction of the through-hole 31 is 0.5 to 3.0 mm, particularly 0.7 to 1.1 mm. And preferred. Further, the center interval 31f in the width direction of the through holes 31 is preferably 0.5 to 2.0 times, particularly 1.0 to 1.2 times the length 31y of the through holes 31 in the front-rear direction. The length 31x in the width direction of 31 is preferably 1.1 to 1.8 times, particularly 1.1 to 1.4 times the center interval 31f in the width direction of the through hole 31. In the state in which the non-stretchable region 70 is extended to the elastic limit in the width direction (in other words, the first sheet layer 20A and the second sheet layer 20B are completely expanded), the center interval 31f in the width direction of the through hole 31 Is equal to the center interval 40f in the width direction of the sheet bonding portion 40, the center interval 31e in the front-rear direction of the through-hole 31 is equal to the center interval 40e in the front-rear direction of the sheet bonding portion 40, and the length 31y in the front-rear direction of the through-hole 31 Is equal to the length 40y in the front-rear direction of the sheet joint 40.

  In the non-stretchable region 70, the first sheet layer 20A and the second sheet layer 20B and the elastic film 30 are not joined except for the portion between the first sheet layer 20A and the second sheet layer 20B in the sheet joining portion 40, And when it has a gap formed by separating the peripheral edge of the through hole 31 of the elastic film 30 and the sheet bonding portion 40 on both sides in the width direction of the sheet bonding portion 40 in a natural length state, the material of the elastic film 30 is Even a non-porous film or sheet is preferable because air permeability is always added by this gap. In the case where the above-described simultaneous formation method of the through hole 31 and the sheet joint portion 40 is adopted, this state naturally occurs regardless of the shape or the like of the sheet joint portion 40.

  Although the shape in the natural length state of each sheet | seat junction part 40 and the through-hole 31 is not specifically limited, In order to eliminate the linear continuity of the width direction of the elastic film 30, it is desirable that an area is small from a softness | flexibility viewpoint. Since it is desirable to have a shape that is long in the front-rear direction, an ellipse that is long in the front-rear direction, a rectangle (see FIGS. 11 and 13D), a rhombus (see FIG. 13B), and a convex lens shape (see FIG. 13). (See (a)), and preferably a concave lens shape (see FIG. 13C). However, if the corner is an acute angle like a diamond, the elastic film 30 is easily broken. On the other hand, the convex lens shape is preferable because the welding of the sheet joining portion 40 is stable, and the concave lens shape is preferable in that the area can be further reduced.

Although the area ratio of the sheet joint portion 40 and the area of each sheet joint portion 40 in the non-stretchable region can be determined as appropriate, in the normal case, if within the following range, the area of each sheet joint portion 40 is small and the sheet It is preferable that the non-stretchable region 70 does not become hard due to the low area ratio of the joint 40.
Area of sheet joint 40: 0.10 to 0.75 mm ² (particularly 0.10 to 0.35 mm ² )
Area ratio of sheet joint 40: 4 to 13% (especially 5 to 10%)

  As described above, the elastic limit elongation of the non-stretchable region 70 can be changed by the arrangement pattern of the through holes 31, the dimensions of the individual through holes 31, and the center interval. Therefore, although not shown, these can be made different at a plurality of locations in the stretchable region 80 or between the plurality of non-stretchable regions 70. For example, it is one preferable mode to make the elastic limit elongation in the non-stretchable region 70 of the front body F larger than the elastic limit elongation in the non-stretchable region 70 of the rear body B.

Although the non-stretchable region 70 has a portion that is linearly continuous along the width direction as in the stretchable region, the elastic limit elongation is remarkably low because the area ratio of the sheet joint portion is higher than that of the stretchable region. May adopt other forms that kill other stretchability, such as a form that is 130% or less, a form that is cut at one or a plurality of places in the width direction, such as a conventional stretch structure using rubber thread.

(Wrinkle forming part)
Characteristically, as in the examples shown in FIGS. 2 and 14, the first sheet layer 20 </ b> A, the elastic film 30, and the second sheet layer 20 </ b> B are formed in the leg-surrounding stretchable region located in the leg-surrounding portion R in the stretchable region 80. The heel forming portion 90 to which the three members are not joined extends along the edge 29 of the leg opening while being spaced from the edge 29 of the leg opening, and is adjacent to the adjacent portion 91 across the heel forming portion 90. Is a portion where the first sheet layer 20A and the second sheet layer 20B are joined by the sheet joining portion 40, and the dimension 90d of the heel forming portion 90 in the direction perpendicular to the edge 29 of the leg opening is the adjacent portion 91. This is larger than the interval 40b in the width direction of the sheet bonding portion 40 and the interval 40d in the front-rear direction of the sheet bonding portion 40.

  The dimension 90d of the flange forming portion 90 in the direction orthogonal to the edge 29 of the leg opening is not particularly limited as long as it is larger than the width-direction interval 40b of the sheet joining portion 40 and the front-rear direction interval 40d of the sheet joining portion 40 in the adjacent portion 91. In a normal case, it is preferably 2 to 6 times the larger of the interval 40b in the width direction of the sheet bonding portion 40 and the interval 40d in the front-rear direction of the sheet bonding portion 40 in the adjacent portion 91.

  As described above, in the mounted state in which the elastic film 30 is contracted to some extent, the collar 25 is formed in the stretchable region 80 including the leg stretchable region by contraction of the first sheet layer 20A and the second sheet layer 20B. Here, when the dimension 90d of the flange forming portion 90 in the direction orthogonal to the edge 29 of the leg opening is larger than the width-direction interval 40b of the sheet bonding portion 40 and the front-rear direction interval 40d of the sheet bonding portion 40 in the adjacent portion 91, The heel forming portion 90 is formed with a leakage preventing ridge 25B which is higher (larger) than the adjacent portion 91, and this becomes a weir extending in the direction around the legs. Therefore, the leakage prevention rod 25B that bulges to the skin side is like a weir with a simple contrivance that merely provides the above-described wrinkle forming portion 90 (non-joined portion) and adjacent portion 91 (joint portion) in the leg stretchable region. It will extend in the leg-circumferential direction, and the leakage preventing property of the edge 29 portion of the leg opening will be improved.

  The wrinkle forming portion 90 may not be bonded to the first sheet layer 20A, the elastic film 30, and the second sheet layer 20B. However, as in the example shown in FIG. 14, if the second sheet layer 20 </ b> B is not joined to the elastic film 30 in the wrinkle forming portion 90, not only the first sheet layer 20 </ b> A (skin side) but also the second sheet layer 20 </ b> B. Since the high collar 25 is formed also on the (outside), it does not have a clean appearance. On the other hand, as shown in FIG. 22, when the second sheet layer 20B is bonded to the elastic film 30 via the hot melt adhesive 30H at least in the wrinkle forming portion 90, the first sheet layer 20A (skin A high leakage prevention ridge 25B is formed on the side), but a low and fine ridge 25 is formed on the second sheet layer 20B (outside), thus improving the leakage prevention performance and providing a clean appearance. .

  The dimension 90d of the heel-forming portion 90 in the direction orthogonal to the edge 29 of the leg opening may be constant in the leg-circumferential direction. However, as the leg-peripheral portion R is closer to the crotch side, leakage prevention becomes more important. Therefore, as shown in the example, the dimension 90d of the heel forming portion 90 in the direction orthogonal to the edge 29 of the leg opening is continuously increased (or may be stepped) as it approaches the crotch side, and the leg surrounding portion R is increased. It is preferable to increase the height of the leakage preventing collar 25B formed as it approaches the crotch side.

The dimension 90d of the flange forming portion 90 in the direction orthogonal to the edge 29 of the leg opening, the width-direction interval 40b of the sheet bonding portion 40, and the interval 40d in the front-rear direction of the sheet bonding portion 40 in the adjacent portion 91 are not particularly limited. In this case, it is desirable to be within the following range.
Dimension 90d of heel-forming portion 90 in the direction orthogonal to leg opening edge 29: 2 to 6 mm
Width direction interval 40b of the sheet joint portion 40 in the adjacent portion 91: 1 to 3 mm
Front-rear direction interval 40d of the sheet joint portion 40 in the adjacent portion 91: 0.5 to 2 mm

  The number of wrinkle forming portions 90 can be determined as appropriate, and can be one as in the example shown in FIG. However, since the leakage prevention rod 25B formed on the first sheet layer 20A is flexible and deformable, there is a risk that a portion having a low damming action may be formed due to the formation of irregularities, etc. There is a risk that the leakage prevention property is insufficient. Therefore, as in the example shown in FIG. 2, it is preferable to provide a plurality of ridge forming portions 90 at intervals so as not to cross each other. The interval between the heel forming portions 90 in the direction orthogonal to the edge 29 of the leg opening can be determined as appropriate, but is 0.5 to 3 times the dimension 90d of the heel forming portion 90 in the direction orthogonal to the edge 29 of the leg opening. It is preferable to do.

(Front / rear holding sheet)
As shown in FIGS. 1 and 4, in order to cover the front and rear end portions of the interior body 10 attached on the inner surface of the exterior body 20 and to prevent leakage from the front and rear edges of the interior body 10, 51 and 52 may be provided. Explaining in more detail about the illustrated form, the front presser sheet 51 extends in the width direction from the inner surface of the folded portion 20C of the waist end region 23 to the position overlapping the front end portion of the inner body 10 in the inner surface of the outer body 20 of the front body F. The rear pressing sheet 52 extends in the width direction from the inner surface of the folded portion 20C of the waist end region 23 to the position overlapping the rear end portion of the inner body 10 in the inner surface of the outer body 20 of the back body B. It extends throughout. When a slight non-adhesive portion is provided over the entire width direction (or only the central portion) at the crotch side edges of the front and rear pressing sheets 51 and 52, not only does the adhesive not protrude, but this portion is slightly removed from the top sheet. Can float and function as a leak-proof wall.

  If the front and rear presser sheets 51 and 52 are attached separately as in the illustrated embodiment, there is an advantage that the degree of freedom of material selection increases, but there are also disadvantages such as an increase in materials and manufacturing processes. Therefore, the folded portion 20C formed by folding the exterior body 20 on the inner surface of the diaper can be extended to a portion overlapping the interior body 10 to form portions equivalent to the press sheets 51 and 52 described above.

<Explanation of terms in the specification>
The following terms in the specification have the following meanings unless otherwise specified in the specification.
-"Front body" and "rear body" mean the front and rear portions of the pants-type disposable diaper in the front-rear direction center, respectively. Moreover, a crotch part means the front-back direction range containing the center of the front-back direction of a pants type disposable diaper, and when an absorber has a constriction part, it means the front-back direction range of the part which has the said constriction part.
-“Elastic limit elongation” means the elongation of the elastic limit in the expansion / contraction direction (in other words, the state in which the first sheet layer and the second sheet layer are completely expanded), and the length at the elastic limit is the natural length. It is expressed as a percentage when 100% is assumed.
The “area ratio” means the ratio of the target portion to the unit area, and the target portion (for example, the sheet joint portion 40, the stretchable region 80, the non-stretchable region 70, the main stretchable portion, the buffer stretchable portion) in the target region. The total area of the through holes 31 and the vent holes) is divided by the area of the target region and expressed as a percentage. In particular, the “area ratio” in the region having the stretchable structure extends to the elastic limit in the stretchable direction. It means the area ratio of the state. In a form in which a large number of target portions are provided at intervals, it is desirable to set the target region to a size that includes 10 or more target portions and obtain the area ratio.
“Elongation rate” means a value when the natural length is 100%.
・ "Weight" is measured as follows. After the sample or test piece has been pre-dried, it is left in a test room or apparatus in a standard state (test location is temperature 23 ± 1 ° C., relative humidity 50 ± 2%) to a constant weight. Pre-drying refers to making a sample or test piece constant in an environment at a temperature of 100 ° C. In addition, it is not necessary to perform preliminary drying about the fiber whose official moisture content is 0.0%. From the test piece in a constant weight state, a sample plate (100 mm × 100 mm) is used to cut a sample having a size of 100 mm × 100 mm. Measure the weight of the sample, multiply it by 100 , calculate the weight per square meter , and use it as the basis weight.
・ "Thickness" of the absorber is a thickness measuring instrument (Peacock, dial thickness gauge large type, model JB (measurement range 0 to 35 mm) or model K-4 (measurement range 0 to 50 mm)) manufactured by Ozaki Mfg. Co., Ltd. Measure the sample and the thickness meter horizontally.
-"Thickness" other than the above is automatically measured using an automatic thickness measuring instrument (KES-G5 handy compression measurement program) under the conditions of load: 0.098 N / cm ² and pressure area: 2 cm ² .
・ "Tensile strength" and "tensile elongation (breaking elongation)" are in accordance with JIS K7127: 1999 "Plastic-Test method for tensile properties-" except that the test piece is rectangular with a width of 35 mm and a length of 80 mm. The initial chuck interval (distance between marked lines) is 50 mm, and the tensile speed is 300 mm / min. As the tensile tester, for example, AUTOGRAPH AGS-G100N manufactured by SHIMADZU can be used.
・ "Elongation stress" means according to JIS K7127: 1999 "Plastics-Test method for tensile properties-" by a tensile test in which the initial chuck interval (distance between marked lines) is 50 mm and the tensile speed is 300 mm / min. This means the tensile stress (N / 35 mm) measured when stretching in the elastic region, and the degree of stretching can be appropriately determined depending on the test object. It is preferable that the test piece has a rectangular shape with a width of 35 mm and a length of 80 mm or more. However, when a test piece with a width of 35 mm cannot be cut out, the test piece is prepared with a width that can be cut out, and the measured value is 35 mm. The value converted to. Even if the target area is small and sufficient specimens cannot be collected, as long as the magnitude of the extension stress is compared, at least a comparison can be made even if the specimens of the same size are used even if they are appropriately small. . As the tensile tester, for example, AUTOGRAPH AGS-G100N manufactured by SHIMADZU can be used.
-"Developed state" means a state where the plate is flattened without contraction or slack.
-Unless otherwise specified, the dimensions of each part mean dimensions in a deployed state, not a natural length state.
・ If there is no description about the environmental conditions in the test and measurement, the test and measurement shall be performed in a test room or equipment in the standard state (test location: temperature 23 ± 1 ° C, relative humidity 50 ± 2%). To do.

  The present invention is applicable to an exterior body of a pants-type disposable diaper.

  DESCRIPTION OF SYMBOLS 10 ... Interior body, 11 ... Top sheet, 12 ... Liquid impervious sheet, 13 ... Absorber, 13N ... Constricted part, 14 ... Packaging sheet, 15 ... Gather nonwoven fabric, 16 ... Gather elastic member, 20 ... Exterior body, 20A ... 1st sheet layer, 20B ... 2nd sheet layer, 20C ... Folded part, 20X ... Film lamination area, 21 ... Side seal part, 23 ... Waist edge part area, 24 ... Waist part elastic member, 25 ... Gutter, 25B ... Leakage prevention ridge, 29 ... edge of leg opening, 30 ... elastic film, 31 ... through hole, 40 ... sheet joint part, 40b ... interval in width direction, 40d ... interval in front and rear direction, 70 ... non-stretchable region, 80 ... stretchable region, 90 ... Wrinkle forming part, 91 ... Adjacent part, B ... Rear body, F ... Front body, L ... Middle part, R ... Leg circumference part, T ... Trunk circumference part.

Claims (5)

In the pants-type disposable diaper in which the side edge of the front body and the side edge of the back body are joined on both sides in the width direction to form a waist opening and a leg opening,
An elastic film is laminated between the first sheet layer positioned on the skin side of the wearer and the second sheet layer positioned on the outer side of the leg surrounding portion and the subsequent portion along the edge of the leg opening. The first sheet layer and the second sheet layer have a film lamination region bonded directly or indirectly by a number of sheet bonding portions arranged at intervals,
The leg periphery portion in the film lamination region has a leg periphery expansion / contraction region that is contracted in the width direction and expandable in the width direction by contraction of the elastic film,
In the leg-surrounding stretchable region, a ridge-forming portion where the first sheet layer, the elastic film, and the second sheet layer are not joined extends in the leg-surrounding direction while being spaced from the edge of the leg opening. And
The adjacent parts facing each other across the ridge-forming part are parts where the first sheet layer and the second sheet layer are joined by the sheet joining part,
The size of the flange forming portion in the direction orthogonal to the edge of the leg opening is larger than the width-direction interval of the sheet bonding portion and the front-rear direction interval of the sheet bonding portion in the adjacent portion,
A pants-type disposable diaper characterized by that.   The pants-type disposable diaper according to claim 1, wherein the second sheet layer is bonded to the elastic film via a hot melt adhesive at least in the heel-forming portion.   The pants-type disposable diaper according to claim 1 or 2, wherein a size of the heel-forming portion in a direction perpendicular to the edge of the leg opening is gradually or continuously enlarged as approaching the crotch side.   The pants-type disposable diaper according to any one of claims 1 to 3, wherein a plurality of the heel-forming portions are provided at intervals so as not to cross each other. The size of the flange forming portion in the direction orthogonal to the edge of the leg opening is 2 to 6 mm, the interval in the width direction of the sheet joint portion in the adjacent portion is 1 to 3 mm, and the sheet joint portion in the adjacent portion The front-rear direction interval is 0.5-2 mm,
The dimension of the flange forming portion in the direction orthogonal to the edge of the leg opening is 2 to 6 times the larger one of the width direction interval of the sheet joint portion and the front-rear direction interval of the sheet joint portion in the adjacent portion. ,
The underpants type disposable diaper of any one of Claims 1-4.

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