JP2010200831A - Absorbent article - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a flexible absorbent article which secures sufficient fitting property of an external sheet by means of an elastic member without an unnecessary thickness. <P>SOLUTION: A vertical range having hip elastic members 25 and a vertical range 31 having bending elastic members 26 and 28 overlap partly or wholly at the front F and the back B of an external sheet 20, and some of the hip elastic members 25 are included in the overlapped range 30. Mutual interval d1 between at least a part of the hip elastic members 25 are wider than mutual interval d2 between the other hip elastic members 25. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

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

  The pants-type disposable diaper includes an exterior sheet having a front body and a back body, and an interior body including an absorbent body fixed to the inner surface of the exterior sheet, and the front body and the back body of the exterior sheet are on both sides. Are joined together to form a waist opening and a pair of left and right leg openings.

  In the pants-type disposable diaper, in order to improve the fit to the body, fixing various elastic members to the exterior sheet in an expanded state (see, for example, Patent Documents 1 to 6), The one provided with the waist elastic member, the waist elastic member, and the curved elastic member (represented in Patent Document 6) has a relatively high fit to the body. Here, a plurality of waist elastic members are arranged in parallel along the width direction at intervals in the vertical direction at the edge of the waist opening. Further, the waist elastic member is disposed along the width direction with a space in the vertical direction in a region closer to the center in the front-rear direction than the waist elastic member. Furthermore, the curved elastic member extends while curving from both side portions of at least one of the front body and the back body so as to go to the opposite body side toward the center in the width direction.

JP-A-7-265357 JP-A-7-299094 JP-A-11-36103 JP 2001-258931 A JP 2001-204762 A JP 2006-043415 A

However, if a large number of waist elastic members and curved elastic members are provided in order to improve the fit, a large number of wrinkles (hereinafter referred to as pleats) due to the contraction are formed densely, and the thickness is unnecessarily increased. In addition, there is a problem that the exterior sheet becomes hard and deteriorates the wearing feeling.
Therefore, the main problem of the present invention is to make the exterior sheet sufficiently flexible without being unnecessarily thick while sufficiently securing the fit property of the exterior sheet by the elastic member.

  As a result of further research on the hard feeling among the above problems, the present inventors have found that the hard feeling is particularly strong in the region where the waist elastic member and the curved elastic member overlap. And when the cause was further researched, it was found that the elasticity of the elastic member strongly influences the hardness of the exterior sheet due to the dense arrangement of the elastic member, and the elasticity of the elastic member due to the dense arrangement of the elastic member. It has been found that the amount of adhesive applied to fix the member increases, and the hardness of the adhesive strongly affects the hardness of the exterior sheet. The present invention described below is based on such knowledge.

<Invention of Claim 1>
By including 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, the front body and the back body of the exterior sheet are joined at both sides. In a pants-type disposable diaper in which a waist opening and a pair of left and right leg openings are formed,
At least one of the front body and the back body of the exterior sheet;
A plurality of elongated waist elastic members extending along the width direction are bonded to the edge of the waist opening at intervals in the vertical direction,
Three or more elongated waistline elastic members extending along the width direction are bonded to the region on the center side in the front-rear direction with respect to the waist elastic member, and spaced apart in the vertical direction.
A curved elastic member that extends while curving so as to go to the opposite body side from the both sides toward the center in the width direction is bonded,
The longitudinal range having the waist elastic member and the longitudinal range having the curved elastic member partially or entirely overlap, and a plurality of waist elastic members are included in the overlapping range, The mutual interval of at least some of the waist elastic members is wider than the mutual interval of the other waist elastic members,
A pants-type disposable diaper characterized by that.

(Function and effect)
The waist elastic member and the curved elastic member need to be provided in a large amount at a certain narrow interval in order to fully exert their respective functions. In this case, the waist region elastic member and the curved elastic member are curved. It is inevitable that an overlapping range with the longitudinal range having the elastic member occurs. However, the problem will occur as described above. Therefore, in the present invention, while allowing such an overlapping range, by providing a wide portion of the waist elastic member within the range, the denseness of the elastic member is suppressed without impairing the fit. It is. Thereby, in the above overlapping range, the pleats are not concentrated on the exterior sheet, the unnecessary increase in thickness, the elastic member itself and hardening due to adhesion thereof are suppressed, and a flexible and comfortable wearing feeling can be obtained. .

<Invention of Claim 2>
The waist elastic member is a plurality in the longitudinal range having the curved elastic member, and a plurality in the intermediate range between the longitudinal range having the curved elastic member and the longitudinal range having the waist elastic member, Each is provided,
The spacing between the at least some waist elastic members is 15 to 50 mm, and the spacing between the other waist elastic members is 10 to 20 mm.
The pants-type disposable diaper according to claim 1.

(Function and effect)
Specifically, it is desirable to provide the waist elastic members at such intervals.

<Invention of Claim 3>
The longitudinal length of the overlapping range is 15 to 30% of the total length of the diaper in the unfolded state, and the ratio of the wide spacing portions of the waist elastic members occupying the overlapping range is the longitudinal length. The pants-type disposable diaper according to claim 2, wherein the ratio is 60 to 100%.

(Function and effect)
The overlapping range of the longitudinal range having the waist elastic member and the longitudinal range having the curved elastic member is preferably wide to some extent as described above, and in this case, the wide interval portion between the waist elastic members is It is preferable to secure this degree.

<Invention of Claim 4>
The waist elastic member, the waist elastic member, and the curved elastic member are sandwiched between a pair of sheet layers constituting the exterior sheet, and are bonded and fixed to the sheet layers with an adhesive, and The bonding part is only an arrangement part of the waist elastic member and the vicinity thereof, an arrangement part of the waist elastic member and the vicinity thereof, an arrangement part of the curved elastic member, and an area within ± 25 mm in each of the vertical and horizontal directions. The listed pants-type disposable diapers.

(Function and effect)
Thus, the hardening by an adhesive agent can be suppressed by reducing an adhesive application area | region as much as possible.

<Invention of Claim 5>
The pants-type disposable diaper according to claim 4, wherein the sheet layer constituting the exterior sheet is a nonwoven fabric, and the outermost nonwoven fabric located on the outermost side has a twist of 3.8 gf · cm / cm or less.

(Function and effect)
This invention is based on the knowledge that the suppleness of the outermost nonwoven fabric among the exterior sheets has a strong influence on the suppleness of the diaper as a whole. Since the thin sheet nonwoven fabric has been generally used as the exterior sheet, this finding was unexpected at first, but it can be reasonably understood considering that the outer sheet has a larger deformation amount. is there. Currently, a spunbonded nonwoven fabric is widely used as the outermost nonwoven fabric of the exterior sheet from the viewpoint of strength. However, the conventional outermost nonwoven fabric has a high degree of twist and is inferior in flexibility. On the other hand, as described above, when a non-woven fabric having a sufficiently low twist is used as the outermost non-woven fabric, the flexibility of the entire diaper is remarkably increased. As a result, skin troubles such as itching and rash are alleviated and it is easy to take off and the like.
The “twisting degree” in the present invention can be measured using, for example, KES-YN1 (manufactured by Kato Tech Co., Ltd.), and the smaller the value, the more flexible the twisting is. To do. Moreover, when an exterior sheet | seat consists of one nonwoven fabric, it itself means an outermost nonwoven fabric.

  As described above, according to the present invention, there is an advantage that the fitting property in the exterior sheet is sufficiently ensured by the elastic member, but it is not unnecessarily thick and rich in flexibility.

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

Hereinafter, an embodiment of the present invention will be described in detail with reference to the accompanying drawings.
1-7 has shown the underpants type disposable diaper 1 of embodiment. This pants-type disposable diaper 1 (hereinafter also simply referred to as diaper) has an exterior sheet 20 having a front body F and a back body B, and an interior body 10 fixed and integrated on 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. The waist opening and a pair of left and right leg openings are formed by folding at the center in the longitudinal direction (front-rear direction), which is the boundary of B, and joining both sides thereof by heat welding or hot melt adhesive. A pants-type disposable diaper.

(External sheet structure example)
As shown in FIGS. 4 to 6, the exterior sheet 20 is a nonwoven fabric sheet having a two-layer structure composed of an upper layer nonwoven fabric 20 </ b> A and a lower layer nonwoven fabric 20 </ b> B (that is, the lower layer nonwoven fabric is the outermost nonwoven fabric in this embodiment). Various elastic members are disposed between 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. 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.

  In particular, in the illustrated exterior sheet 20, as the elastic member, in the developed shape shown in FIGS. 1 to 3, the waist elastic members 24, 24. The back body B has a plurality of waist elastic members 25, 25... Arranged at intervals in the vertical direction along the width direction, and the waist elastic members in the front body F and the back body B respectively. Apart from the groups 25, 25..., The both sides of the interior body 10 are curved toward the opposite body side from the both side joining edge joining the front body F and the back body B toward the center in the width direction. A plurality of curved elastic members 26, 28, which extend to overlapping portions (or do not necessarily overlap each other, such as in the vicinity of both side portions) and are arranged at intervals without crossing each other, are provided. Have . In addition, in this exterior sheet 20, what is called a leg periphery elastic member substantially continuous along the leg periphery line 29 is not provided.

  The waist elastic members 24, 24... Are disposed in the vicinity of the waist opening edge in the range of the side joint edges 21 and 22 where the front body F and the back body B are joined, with a space in the vertical direction. A plurality of thread rubber-like elastic members for attaching a diaper to the body by applying an expansion / contraction force so as to tighten around the waist of the body. As the waist elastic member 24, thread rubber is used in the illustrated example, but a tape-like elastic member may be used, for example. 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 elastic rubber members arranged along the width direction at intervals in the vertical direction over a range from the upper part to the lower part of the side joint edges 21, 22. It is an elastic member, and applies elastic force in the width direction to the waist portions of the front body F and the back body B, respectively, to bring the diaper into close contact with the body. The boundary between the waist elastic members 24, 24... And the waist elastic members 25, 25. For example, among the elastic members arranged in the width direction with an interval in the vertical direction on the front body F and the back body B, even if the number cannot be specified, several on the upper side function as the waist elastic members. The remaining elastic members only 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 an intersecting portion 70 having a longitudinal crossing angle θ of 60 ° or less in a region overlapping with both side portions of the interior body. 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. Three or more, preferably five or more are arranged with an interval of about 3 to 20 mm, preferably about 6 to 16 mm.

  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, the vertical crossing angle θ is arranged along a predetermined curve having a crossing portion 70 having a value of 60 ° or less. There may be one ventral curved elastic member 2826, but a plurality of ventral curved elastic members 2826 are preferable. In the illustrated example, there are five thread-like elastic members, and these ventral curved elastic members 28, 28. Without being spaced apart. The ventral curved elastic member groups 28, 28... Are also 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. Three or more, preferably five or more are arranged with an interval of about 3 to 20 mm, preferably about 6 to 16 mm.

  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. For example, as the latter example, the waist elastic members 25, 25... And the curved elastic members 26... 28 are crossed from the side joint edge 22 on one side across the interior body 10 and on the other (opposite) side. After providing continuously to the joining edge 22, the general form which cut | disconnects part or all of the part which traverses the interior body 10, and makes it discontinuous is contained. By making the elastic member discontinuous at the portion overlapping the interior body 10, it is possible to further prevent the interior body (particularly the absorber 13) from contracting in the width direction. Of course, the waist elastic members 25, 25... And the curved elastic members 26, 28... Can be continuously arranged across the interior body 10.

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

Unlike the illustrated example, the curved elastic member may be provided only on one of the front body F and the back body B. 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. Although a form (not shown) in which a part or all of the group of the curved elastic members B arranged can be adopted, the group of the curved elastic members 28 arranged on the front body F side as in the illustrated example, Further, a configuration in which the group of the curved elastic members B arranged on the back body B side is separated in the longitudinal direction at a position slightly deviated from the middle part in the front-rear direction, particularly the front body F without crossing each other, is preferable. The minimum vertical separation distance in the vertical separation range 90 is preferably about 10 to 15 mm, and a wide fixed region described later is preferably provided in this portion.
Further, the curved elastic members 26, 28,... May not be entirely curved as in the illustrated example, and may partially have a linear portion.

(Configuration related to flexibility of exterior sheet 20)
Characteristically, the longitudinal range having the waist elastic members 25... And the longitudinal range 31 having the curved elastic members 26... 28 overlap partially (or all), and this overlapping range. 30 includes a plurality of waistline elastic members 25 (for example, about 5 to 10), and at least a part of the waistline elastic members 25 has an interval d1 between the other waistline elastic members 25. It is wider than the mutual interval d2. Further, even outside the overlapping range 30, the waistline elastic members 25... Are in an intermediate range 32 between the longitudinal range 31 having the curved elastic members 26, 28... And the longitudinal range having the waist elastic member 24. A plurality (for example, about 10 to 16) are provided.

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

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

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

  On the other hand, the waist elastic member 24, the waist elastic member 25, and the curved elastic members 26, 28,... Are sandwiched between a pair of sheet layers 20A, 20B constituting the exterior sheet 20, and the sheet layers 20A, 20B, The adhesive is fixed to 20B with an adhesive, and the amount of adhesive applied greatly affects the flexibility of the exterior sheet 20. Therefore, as shown in FIG. 8, the adhesive portions B1 and B2 by the adhesive include the arrangement portion and the vicinity thereof of the waist elastic member 24, the arrangement portion and the vicinity thereof of the waist elastic member 25, and the curved elastic member 26. , 28... And a region within a predetermined distance a within each length and width (normally within ± 25 mm, more preferably within ± 10 mm, particularly preferably within ± 5 mm), and both sheets other than these adhesives. It is preferable not to apply an adhesive between the layers. In this way, by reducing the adhesive application portion as much as possible, hardening by the adhesive can be suppressed at each stage. In addition, when this is combined with an increase in the local spacing between the waist elastic members 25...

  FIG. 8 shows application sites B1, B2 of the hot melt adhesive in the manufacturing process, and the curved elastic members 26, 28, ... are in a state before cutting a portion crossing the interior body 10 as indicated by a two-dot chain line. Is shown. Adhesives B1 and B2 for fixing the waist elastic member 24 and the waist elastic member 25 to the two sheet layers 20A and 20B are substantially applied only to the arrangement portions of the elastic members 24 and 25 and the vicinity thereof. Yes. Such application of the adhesive can be realized by sandwiching the elastic members 24 and 25 having the adhesive applied to the outer peripheral surface between the two sheet layers 20A and 20B, and the outer peripheral surfaces of such elastic members 24 and 25. The adhesive can be applied to a Nordson Surerup nozzle.

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

(Structural example of interior body)
As shown in FIGS. 5 to 7, the interior body 10 has an absorbent body 13 interposed between a liquid-permeable top sheet 11 made of a nonwoven fabric or the like and a liquid-impermeable back side sheet 12 made of polyethylene or the like. The excretory fluid that has permeated through the top sheet 11 is absorbed and retained.

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

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

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

  It is preferable that solid gather BSs that fit around the legs are formed on both sides of the interior body 10. This three-dimensional gathered BS is formed by the gathered nonwoven fabric 15. As the gathered nonwoven fabric, as shown in FIG. 6 and FIG. 7, 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 stretch 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 stretch force as shown by a two-dot chain line in FIG. It is.

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

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

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

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

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

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

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

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

(About the non-woven fabric constituting the exterior sheet)
Of the non-woven fabrics constituting the exterior sheet 20, at least the outermost non-woven fabric 20B preferably has a twist degree of 3.8 gf · cm / cm or less. 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, if a nonwoven fabric with a sufficiently low twist is used, the flexibility of the diaper as a whole is significantly increased. 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.

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

  Furthermore, each sample nonwoven fabric is used as the nonwoven fabric 20A, 20B, 51, 61 of the exterior sheet 20 in the pants-type disposable diaper having the structure shown in FIGS. 1 to 7, and a pants-type disposable diaper similar to that shown in the figure is used. It was prepared and subjected to sensory evaluation on the suppleness of the diaper (◯: rich in suppleness, △: normal, ×: stiff).

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

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

  DESCRIPTION OF SYMBOLS 1 ... Pants type disposable diaper, 10 ... Interior body, 11 ... Liquid-permeable surface sheet, 12 ... Liquid-impermeable back side sheet, 13 ... Absorber, 14 ... Packaging sheet, 15 ... Gathered nonwoven fabric, 16 ... Yarn-like elastic stretch 20 ... exterior sheet, 21.22 ... side joint edge, 24 ... waist elastic member, 25 ... waist elastic member, 26 ... dorsal curve elastic member, 28 ... ventral curve elastic member, 29 ... leg circumference Line, 20C ... exterior sheet folded portion, 70 ... intersection, 71 ... non-fixed region, 80, 81, 82 ... fixed region, [theta] ... longitudinal crossing angle, F ... front body, B ... back body.

Claims (5)

By including 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, the front body and the back body of the exterior sheet are joined at both sides. In a pants-type disposable diaper in which a waist opening and a pair of left and right leg openings are formed,
At least one of the front body and the back body of the exterior sheet;
A plurality of elongated waist elastic members extending along the width direction are bonded to the edge of the waist opening at intervals in the vertical direction,
Three or more elongated waistline elastic members extending along the width direction are bonded to the region in the front-rear direction center portion side than the waist elastic member, with a vertical interval therebetween,
A curved elastic member that extends while curving so as to go to the opposite body side from the both sides toward the center in the width direction is bonded,
The longitudinal range having the waist elastic member and the longitudinal range having the curved elastic member partially or entirely overlap, and a plurality of waist elastic members are included in the overlapping range, The mutual interval of at least some of the waist elastic members is wider than the mutual interval of the other waist elastic members,
A pants-type disposable diaper characterized by that. The waist elastic member is a plurality in the longitudinal range having the curved elastic member, and a plurality in the intermediate range between the longitudinal range having the curved elastic member and the longitudinal range having the waist elastic member, Each is provided,
The spacing between the at least some waist elastic members is 15 to 50 mm, and the spacing between the other waist elastic members is 10 to 20 mm.
The pants-type disposable diaper according to claim 1.   The longitudinal length of the overlapping range is 15 to 30% of the total length of the diaper in the unfolded state, and the ratio of the wide spacing portions of the waist elastic members occupying the overlapping range is the longitudinal length. The pants-type disposable diaper according to claim 2, wherein the ratio is 60 to 100%.   The waist elastic member, the waist elastic member, and the curved elastic member are sandwiched between a pair of sheet layers constituting the exterior sheet, and are bonded and fixed to the sheet layers with an adhesive, and The bonding part is only an arrangement part of the waist elastic member and the vicinity thereof, an arrangement part of the waist elastic member and the vicinity thereof, an arrangement part of the curved elastic member, and an area within ± 25 mm in each of the vertical and horizontal directions. The listed pants-type disposable diapers.   The pants-type disposable diaper according to claim 4, wherein the sheet layer constituting the exterior sheet is a nonwoven fabric, and the outermost nonwoven fabric located on the outermost side has a twist of 3.8 gf · cm / cm or less.

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