JP2012070917A - Pull-up disposable diaper - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an pull-up disposable diaper having side sealing portions equipped with an enough joint strength and a peeling easiness.SOLUTION: In the pull-up disposable diaper, both side parts of an outer decorative sheet of a front body F joined with side sealing portions 21 and 22 and both side parts of the outer decorative sheet of a back body B are jointed so that at least one or more lamination number changing portions in which the number of lamination of sheet raw materials to be joined are changed may be present in the intermediate parts in the longitudinal direction. The side sealing portions 21 and 22 are formed so that at least side edges of the insides in the width directions form wavy shapes, and the lamination number changing portions are positioned between the top points of the outsides in the width direction on the wavy side edges and adjacent top points on the insides in the width direction on the waist side.

Description

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

The pants-type disposable diaper includes an exterior sheet having a front body and a back body, and an interior body including an absorbent body fixed to the inner surface of the exterior sheet, and the front body and the back body of the exterior sheet are on both sides. The waist opening and the pair of left and right leg openings are formed by joining the side seal portions in FIG.
Many users of pants-type disposable diapers tear off the side seals on both sides after use and discard the diaper. For this reason, it is desirable that the side seal portion has sufficient bonding strength when worn and can be easily peeled off after use.
Side seals in pants-type disposable diapers generally have many small joints by welding along the vertical direction (longitudinal direction) on both sides, and are generally joined in dotted lines. (For example, see Patent Documents 1 to 3). By making the side seal part into a dotted line shape, there is an advantage that even if it is welded more strongly, a large force is not required at the time of peeling.

JP 2009-131539 A JP 2009-160128 A JP 2009-160129 A

However, in a conventional pants-type disposable diaper, if the side seal part is peeled off from the waist opening or leg opening, the side seal part is not peeled off in the middle, and the front or rear exterior sheet is torn. In some cases, the side seal portion could not be removed. In this case, it is necessary to redo the side seal portion from the opposite side.
Then, the main subject of this invention is providing the underpants type disposable diaper which does not generate | occur | produce such a peeling failure of a side seal part easily.

As a result of earnest research on the above issues, the following findings were obtained. That is, the exterior sheet is formed by laminating a plurality of sheet materials to sandwich the elastic elastic member, and the number of sheet materials stacked in the side seal portion is midway from the waist opening to the leg opening. For example, it is common to change from 8 layers to 6 layers and from 6 layers to 4 layers. In such a form, when the side seal part is peeled off from the waist opening part or the leg opening part, when the peeling force acts obliquely inward with respect to the vertical direction at a part where the number of laminated sheets changes. In addition, a situation in which the exterior sheet of the front body or the back body is torn without the side seal portion being peeled off easily occurs. The present invention described below is based on such knowledge.
In the present invention, the “longitudinal direction” refers to the longitudinal direction of the pants-type disposable diaper before joining, and the “lateral direction” refers to the width direction.

<Invention of Claim 1>
An exterior sheet that forms a front body and a back body, and an interior body including an absorbent body that is fixed to an inner surface of the exterior sheet, and both sides of the exterior sheet in the front body and both sides of the exterior sheet in the back body In the pants-type disposable diaper in which a waist opening and a pair of left and right leg openings are formed by forming a side seal part by joining each of
The exterior sheet is formed by laminating a plurality of sheet materials in a longitudinal range having at least the side seal portion,
The side seal part has at least one lamination number changing part in which the number of laminations of the sheet material to be joined changes in the longitudinal intermediate part thereof,
The side seal portion has at least a widthwise inner side edge having a wavy shape, and the number of stacked layers between the wavy side edge on the widthwise outer apex and the widthwise inner apex adjacent to the waist side. The change part is configured to be located,
A pants-type disposable diaper characterized by that.

(Function and effect)
As described above, at least the side edge on the inner side in the width direction of the side seal portion has a wave shape, and the number of laminations between the apex on the outer side in the width direction and the apex on the inner side in the width direction adjacent to the waist side. If it is configured so that the changing part is located, it will reach the part where the number of laminated sheet materials changes in the process of peeling the side seal part from the waist opening or leg opening, and further peeling force from there Since the direction of the peeling force acts obliquely outward with respect to the vertical direction when the is acting, it is difficult to cause a situation in which the side seal portion is not peeled off and the front or rear body exterior sheet is torn.

  In addition, in the side seal portion, the sheet material joint portion loses the flexibility of the sheet, but by making the side edge on the inner side in the width direction of the side seal portion wavy, the portion that contacts the skin of the side seal portion is reduced. , The feeling of wear is improved as compared with the linear shape.

  In addition, the side edge of the side seal portion is wavy, in addition to the form in which the joint portion of the sheet material is continuous in the vertical direction and the side edge is wavy, the joint portion of the sheet material is intermittent in the vertical direction. Are included, and the change in the width direction position of the joint side end in the vertical direction is wavy.

<Invention of Claim 2>
The side seal portion is formed by intermittently forming a large number of joint portions of the sheet material in the longitudinal direction, and joining the joint portion located at the end portion on the waist opening side and the end portion on the leg opening portion side. The portion has a shape in which the longitudinal length increases from the outer side in the width direction toward the inner side in the width direction, and the joint portion positioned at the intermediate portion in the vertical direction between the vertical portions increases from the outer side in the width direction toward the inner side in the width direction. The pants-type disposable diaper according to claim 1, wherein the pants-type disposable diaper has a shape whose direction length decreases.

(Function and effect)
As described above, by changing the longitudinal length of the joint portion of the side seal portion, when worn, the end portion on the side of the waist opening and the end portion on the leg opening portion side of the side seal portion are accidentally peeled off. In the middle part in the longitudinal direction after the side seal part starts to be peeled off when changing the diaper, it can be peeled off with a weaker force, and the length of the joint part in the middle part in the longitudinal direction is further reduced. The feeling of wearing is also improved because the part that hits the skin is reduced in length.

  As described above, according to the present invention, when the side seal portion is peeled off, the side seal portion is not peeled off in the middle, and it is difficult to cause a situation such as tearing the exterior sheet of the front body or the back body. Is 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 CC sectional drawing of FIG. It is AA sectional drawing of FIG. It is BB sectional drawing of FIG. It is sectional drawing which shows the other example of FIG. It is sectional drawing which shows the other example of FIG. It is a principal part enlarged view which shows the shape of a side seal part. (A) The figure which looked at the underpants type disposable diaper after side seal part joining from the ventral side, (B) DD sectional view. It is an enlarged view which shows the side seal part joining pattern of E part of FIG. It is a principal part enlarged view which shows the other example of FIG. 8 (A).

Hereinafter, an embodiment of the present invention will be described in detail with reference to the accompanying drawings.
1-5 has shown the underpants type disposable diaper 1 of embodiment. The pants-type disposable diaper 1 (hereinafter also simply referred to as a diaper) includes an exterior sheet 20 that forms a front body F and a back body B, and an interior body 10 that is fixed and integrated with the inner surface of the exterior sheet 20. The interior body 10 is formed by interposing an absorber 13 between a liquid-permeable top sheet 11 and a liquid-impermeable back sheet 12. In manufacturing, after the back surface of the interior body 10 is fixed to the inner surface (upper surface) of the exterior sheet 20 by a joining means such as a hot melt adhesive G, the interior body 10 and the exterior sheet 20 are the front body F and the back body. Folded at the center of the vertical direction (front-rear direction) which is the boundary of B, both sides thereof are joined to each other by heat welding or hot melt adhesive, etc., and side seal portions 21 and 22 are formed. And it becomes a pants type disposable diaper in which a pair of left and right leg openings are formed.

(External sheet structure example)
As shown in FIGS. 3 to 5, the outer sheet 20 is a non-woven sheet having a two-layer structure composed of an upper layer non-woven fabric 20 </ b> A and a lower layer non-woven fabric 20 </ b> B (that is, in this embodiment, the lower layer non-woven fabric is the outermost non-woven fabric). Various elastic members are sandwiched and fixed in an expanded state between the nonwoven fabric of the upper layer nonwoven fabric 20A and the lower layer nonwoven fabric 20B and between the nonwoven fabrics of the folded portion 20C formed by folding the lower layer nonwoven fabric 20B to the inner surface side at the waist opening edge, thereby imparting elasticity. ing. The planar shape has a pseudo hourglass shape as a whole by concave leg-around lines 29 formed to form leg openings on both sides of the middle. As the elastic member, a synthetic rubber or natural rubber processed into an arbitrary form such as a thread, string, net, or sheet can be used.

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

  The waist elastic members 24, 24... Are a plurality of thread rubber-like elastic members arranged in the longitudinal direction of the longitudinal range having the side seal portions 21, 22 at intervals in the longitudinal direction in the vicinity of the waist opening edge. It is for attaching the waist opening edge of a diaper to a body by giving an expansion-contraction force so that the waist part of a body may be tightened. For the waist elastic member 24, rubber thread is used in the illustrated example. However, for example, a tape-like elastic member may be used. Moreover, although the waist part elastic members 24, 24 ... of an illustration form are clamped between the nonwoven fabrics of the folding | returning part 20C of the lower layer nonwoven fabric 20B in a waist part, even if it clamps between 20 A of upper layer nonwoven fabrics, and the lower layer nonwoven fabric 20B. good.

  The waist elastic members 25, 25... Are spaced apart in the longitudinal direction over a range from the upper part to the lower part of the range in the longitudinal direction corresponding to the side seal portions 21, 22 and the crotch side. It is an elongated elastic member, such as rubber thread, arranged along the width direction, for applying a stretching force in the width direction to the waist part of the front body F and the back body B, respectively, and for bringing the diaper into close contact with the body Is. Note that the boundary between the waist elastic members 24, 24... And the waist elastic members 25, 25. For example, even if the number of the elastic members arranged in the width direction with the front body F and the back body B spaced apart in the vertical direction cannot be specified, some of the upper members function as the waist elastic members. The remaining elastic members only have to function as waist elastic members.

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

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

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

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

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

(Structural example of interior body)
As shown in FIGS. 3 to 5, the interior body 10 has an absorbent body 13 interposed between a liquid-permeable top sheet 11 made of nonwoven fabric or the like and a liquid-impermeable back side sheet 12 made of polyethylene or the like. The excretory fluid that has permeated through the top sheet 11 is absorbed and retained.

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

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

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

  In addition, the above-mentioned bending fitting part 40 can also assist the formation by providing a groove 41 or a slit along the longitudinal direction in the crack facing part of the absorbent body 13, and in that case, bending at an appropriate position as a fold. The fitting part 40 is formed and the shape thereof is easily maintained.

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

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

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

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

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

(Front / rear presser sheet)
As shown in FIGS. 1 and 3, in order to cover the front and rear end portions of the interior body 10 mounted on the inner surface of the exterior sheet 20 and to prevent leakage from the front and rear edges of the interior body 10, 50 and 60 are preferably provided. The illustrated embodiment will be described in more detail. The front presser sheet 50 extends over the entire width direction from the inner surface of the folded portion 20C of the waist side end portion to the position overlapping the front end portion of the interior body 10 in the inner surface of the front body F. The rear presser sheet 60 extends across the entire width direction from the inner surface of the folded portion 20C at the end on the waist side to the position overlapping the rear end of the interior body 10 in the inner surface of the back body B. If a slight non-adhesive portion is provided over the entire width in the crotch side edge of the front and rear presser sheets 50, 60, not only does the adhesive not protrude, but this portion is slightly lifted from the top sheet to function as a leak-proof wall. be able to.

  As shown in FIGS. 1 and 3, when the front and rear presser sheets 50 and 60 are attached as separate bodies, there is an advantage that the degree of freedom of material selection is increased, but there are also disadvantages such as an increase in materials and manufacturing processes. Therefore, as shown in FIG. 6, the folded portion 20 </ b> C formed by folding the exterior sheet 20 on the inner surface of the diaper 1 is extended to a portion that overlaps the absorbent pad 200 to form a portion equivalent to the presser sheets 50 and 60 described above. You can also

  Moreover, as shown in FIG. 7, you may distribute the pressing sheets 50 and 60 on the outer side of the folding | returning part 20C of a waist side edge part, ie, between the upper layer nonwoven fabric 20A and the folding | returning part 20C.

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

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

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

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

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

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

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

(Side seal part)
The side seal portions 21 and 22 at the diaper side end portions are formed by heat welding, hot melt adhesive, ultrasonic bonding, or the like. A detailed form of the side seal portion is shown in FIGS.
The side seal parts 21 and 22 are formed in a wave shape having apexes on the inner side and the outer side in the width direction of the diaper. The corrugated wavelength 31 is preferably 40 to 150 mm, particularly 50 to 100 mm, and the corrugated wave height 32 is preferably 2.0 to 12 mm, particularly 4.0 to 10 mm. The width 33 of the side seal part itself is preferably 3.0 to 15 mm, particularly 5.0 to 12 mm.

  8A and 8B correspond to the vertical direction. The number of stacked sheet materials in the portions a, b, c, and d in FIG. 8B is switched to 6, 8, 6, and 4, respectively. The side seal portion 22 is positioned so that the portion where the number of stacked sheets is switched (the number of stacked layers changing portion) is positioned between the apex on the outer side in the width direction of the corrugation and the apex on the inner side in the width direction on the adjacent waist side. Arranged. Furthermore, in order to prevent unexpected tearing of the sheet, it is preferable that an elastic member is not disposed in the stacking change portion and the vicinity thereof. In addition, the number of sheet | seat lamination | stacking and the number of lamination | stacking number change parts are not limited to said numerical value, It can change suitably according to the function of a diaper.

  FIG. 9 shows an enlarged view of the side seal portion. The pattern of the joint part 30 of the side seal part is not particularly limited, but if it is intermittent as shown in FIGS. 9A and 9B rather than being continuous in the vertical direction, it is easy to peel off while strengthening the joint. Further, it is preferable because it can be held. Moreover, the nonwoven fabric which comprises an exterior sheet and a holding | suppressing part usually loses the softness | flexibility in a junction part, However, By making a junction part intermittent, the influence on the wearing feeling of a junction part can be made small. . The bonding pattern shown in FIG. 9A has intermittent portions parallel to the width direction, but may be a pattern in which intermittent portions are arranged obliquely with respect to the width direction (not shown). Furthermore, as illustrated in FIG. 9B, the joint portion 30 is preferably configured to have a shape having a small inside in the width direction and a large outside. By setting it as such a shape, the joint part of the width direction inner side which is easy to touch skin becomes small, and it becomes possible to reduce deterioration of a feeling of wear more.

  The joint portion 30 may have a shape that is continuous in the vertical direction. In this case, as shown in FIG. 9C, when the entire side seal portion 22 is corrugated and the joint portion 30 is arranged in the side seal portion 22 as a minute corrugation, the pulling of the side seal portion 22 is performed. Since ease of peeling is not impaired, it is preferable.

  FIG. 10 shows another example of the side seal portions 21 and 22. The side seal portions 21 and 22 achieve the object of the present invention as long as at least the inner side in the width direction is wavy. Therefore, the outer side in the width direction can be linearly formed in the vertical direction as in the illustrated example. In this case, in the manufacturing process, fine alignment in the width direction of the diaper is not required when the side seal portion is applied, and the shape can be obtained by cutting the side end portion after the side seal portion is applied.

  In addition, about the shape of the side seal part 21, it is preferable that all are the same as the side seal part 22, or it is set as a substantially line symmetrical shape with respect to the center line of the width direction of a diaper.

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

  DESCRIPTION OF SYMBOLS 1 ... Pants type disposable diaper, 10 ... Interior body, 11 ... Liquid-permeable surface sheet, 12 ... Liquid-impermeable back side sheet, 13 ... Absorber, 14 ... Packaging sheet, 15 ... Gathered nonwoven fabric, 16 ... Yarn-like elastic stretch 20 ... exterior sheet, 21, 22 ... side seal part, 24 ... waist elastic member, 25 ... waist elastic member, 26 ... dorsal curve elastic member, 28 ... ventral curve elastic member, 29 ... leg circumference line , 20C ... exterior sheet folded portion, 30 ... joint, F ... front body, B ... back body.

Claims (2)

An exterior sheet that forms a front body and a back body, and an interior body including an absorbent body that is fixed to an inner surface of the exterior sheet, and both sides of the exterior sheet in the front body and both sides of the exterior sheet in the back body In the pants-type disposable diaper in which a waist opening and a pair of left and right leg openings are formed by forming a side seal part by joining each of
The exterior sheet is formed by laminating a plurality of sheet materials in a longitudinal range having at least the side seal portion,
The side seal part has at least one lamination number changing part in which the number of laminations of the sheet material to be joined changes in the longitudinal intermediate part thereof,
The side seal portion has at least a widthwise inner side edge having a wavy shape, and the number of stacked layers between the wavy side edge on the widthwise outer apex and the widthwise inner apex adjacent to the waist side. The change part is configured to be located,
A pants-type disposable diaper characterized by that.   The side seal portion is formed by intermittently forming a large number of joint portions of the sheet material in the longitudinal direction, and joining the joint portion located at the end portion on the waist opening side and the end portion on the leg opening portion side. The portion has a shape in which the longitudinal length increases from the outer side in the width direction toward the inner side in the width direction, and the joint portion positioned at the intermediate portion in the vertical direction between the vertical portions increases from the outer side in the width direction toward the inner side in the width direction. The pants-type disposable diaper according to claim 1, wherein the pants-type disposable diaper has a shape whose direction length decreases.

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