JP6546251B2 - Telescopic member, disposable wearing article having the telescopic member, and method of manufacturing telescopic member - Google Patents

Description

  The present invention relates to a stretchable member having a stretchable structure in which an elastic sheet such as an elastic film is sandwiched between a first sheet layer and a second sheet layer, and a disposable wearing article having the stretchable member.

  In disposable wearing articles such as disposable diapers, in order to improve the fit to the body surface, it is common to impart stretchability to appropriate places such as around the legs and around the waist. Conventionally, as a method for imparting stretchability, a method of attaching an elongated elastic member such as thread rubber in a state of being stretched in the longitudinal direction is widely adopted, but in the case of wanting to impart stretchability with a certain width In the above, a mode is adopted in which thread rubbers are fixed in a state of being arranged side by side at intervals in the width. Moreover, as a thing excellent in the fit property as a surface, the method of attaching in the state which expand | extended the elastic sheet in the provision direction of stretchability is also proposed. (See, for example, Patent Document 1 and Patent Document 2).

  The elastic member is laminated between the first sheet layer and the second sheet layer, and the elastic member including the elastic sheet is in a state in which the elastic film is expanded in the elastic direction, the first sheet layer and the second sheet A layer is welded through a bonding hole formed in an elastic film at a large number of point-like sheet bonding portions arranged at intervals in the stretching direction and the direction orthogonal thereto, respectively. Then, in the natural length state, in the natural length state, as the elastic sheet shrinks between the sheet bonding portions, the distance between the sheet bonding portions narrows, and the sheet bonding portion in the first sheet layer and the second sheet layer A weir is formed extending in a direction intersecting the expansion and contraction direction. On the other hand, at the time of elongation, as the elastic sheet elongates between the sheet joints, the space between the sheet joints and the wrinkles in the first sheet layer and the second sheet layer spread, and the completeness of the first sheet layer and the second sheet layer Elastic extension is possible to the deployed state. The elastic region by this elastic sheet is not only excellent in planar fit, but there is no bonding between the first sheet layer and the second sheet layer and the elastic sheet, and also the bonding of the first sheet layer and the second sheet layer There is an advantage that it is very flexible because it is extremely small, and that the bonding holes of the elastic sheet also contribute to the improvement of air permeability.

  On the other hand, since the stretchability and appearance of the stretchable member including the elastic sheet changes depending on the shape of the sheet bonding portion, it is desirable to provide a plurality of sheet bonding portions having different shapes according to the portion of the disposable wearing article.

  However, when a plurality of sheet junctions having different shapes are provided, the first sheet layer and the second sheet layer do not weld at a part of the sheet junctions, or they are peeled off due to a weak force of welding. There was a problem (welding failure).

JP, 2016-189932, A JP, 2015-204982, A

  Then, the main subject of this invention is making welding defect in the case of having a sheet | seat junction part from which a shape differs from occurring easily.

The elastic member which solved the said subject, the disposable wearing article which has this elastic member, and the manufacturing method of an elastic member are as follows.
<First aspect>
An elastic sheet is interposed between the first sheet layer made of non-woven fabric and the second sheet layer made of non-woven fabric, and the plurality of sheet junctions where the first and second sheet layers are arranged at intervals. Has an elastic sheet stretchable structure welded through a joint hole penetrating the elastic sheet,
The area having the elastic sheet expansion / contraction structure has an expansion / contraction area which is contracted in the expansion / contraction direction by the contraction of the elastic sheet and is extensible in the expansion / contraction direction,
The area | region which has the said elastic sheet expansion-contraction structure has a sheet | seat junction part from which a shape differs,
The bonding reference diameter is 0.2 mm or more, the maximum value of the bonding reference diameter is 1 to 3 times the minimum value, and the circumferential length of all the sheet bonding portions in the region having the elastic sheet stretch structure are bonding 1 to 15 times the circumferential length of the circle whose diameter is the reference diameter,
Expandable member characterized in that.

(Action effect)
As a result of researches on the above-mentioned welding defects, the inventors of the present invention have found that welding defects when there are sheet junctions of different shapes increase the linear pressure when forming the sheet junctions (in ultrasonic sealing, the force pressure is high) We have found that the improvement is not only limited, but it is not preferable because it leads to premature wear and breakage of equipment such as anvil rolls. Therefore, as a result of further research on the cause of welding defects, welding defects are unlikely to occur by setting the bonding reference diameter and circumferential length in the specific range as described above, even if there are sheet junctions of different shapes. We have found out what we can do. Here, the bonding reference diameter means the diameter of the largest inscribed circle inscribed in the outer shape of the sheet bonding portion.

  The reason why the welding failure can be made less likely to occur by setting the bonding reference diameter and the circumferential length in the specific range as described above is considered as follows. That is, for welding, it is necessary for the heat to spread to a certain extent in a radial direction from the center of the heating portion to a certain extent and to a certain extent and to melt the nonwoven fabric. To this end, the sheet bonding portion preferably has a shape that can include a circle of a sufficient size, that is, has a bonding reference diameter of a certain degree or more. The lower limit of the bonding reference diameter is 0.2 mm according to the knowledge of the present inventor. In addition, excessively long sheet junctions having an excessively complicated outer shape are likely to cause partial welding failure. From this viewpoint, the circumferential length of the sheet bonding portion is preferably in the above range. Furthermore, if the difference in the reference bonding diameter of the sheet bonding portion is too large, welding failure is likely to occur if the linear pressure at the time of forming the sheet bonding portion is matched to the sheet bonding portion having the large bonding reference diameter. In addition, if the linear pressure at the time of forming the sheet bonding portion is increased according to the sheet bonding portion having a small bonding reference diameter, there is a possibility that it may lead to early wear and breakage of equipment such as an anvil roll. On the other hand, when the bonding reference diameter is set in the specific range as described above, welding that is unlikely to cause welding defects can be performed with an appropriate pressure.

<Second aspect>
The first sheet layer and the second sheet layer are non-woven fabrics having a fineness of 0.7 to 6 dtex and a basis weight of 10 to 25 g / m ² ,
All the said sheet | seat junction parts in the area | region which has the said elastic sheet expansion-contraction structure are 0.2-0.8 mm in the said junction reference diameter,
The telescopic member of the first aspect.

(Action effect)
In order to achieve both suppression of welding defects and prevention of early wear and breakage of the device, in particular, the non-woven fabric and the bonding standard diameter in the above range are preferable.

<Third aspect>
The area having the elastic sheet expansion and contraction structure includes the expansion and contraction area and a non-expansion and contraction area provided on at least one side in the expansion and contraction direction of the expansion and contraction area.
The area ratio of the sheet bonding portion in the stretchable region is 0.5 to 1 times the area ratio of the sheet bonding portion in the non-stretchable region,
The boundary between the stretchable region and the non-stretchable region has a shape in which the boundary between the stretchable region and the non-stretchable region is continuously shifted only to one side in the stretch direction from the one end to the other end.
The telescopic member of the first or second aspect.

(Action effect)
The expansion and contraction characteristics can be changed by changing the area ratio of the sheet bonding portion. However, if the area ratio of the sheet joint changes rapidly, that is, if the boundary between the stretchable region and the non-stretchable region is along the orthogonal direction orthogonal to the stretch direction from one end to the other end, welding occurs In this case, the linear pressure changes rapidly at the boundary between the stretchable region and the non-stretchable region. Such a rapid change in linear pressure may lead to premature wear and breakage of equipment such as an anvil roll. On the other hand, in the case of this aspect, since there is no rapid change in linear pressure, there is little possibility of leading to premature wear and breakage of the device such as an anvil roll.

<Fourth aspect>
An integral exterior body extending from the front to the back, or an exterior provided separately for the front and the back, and an interior extending to the front and back of the crotch attached to the widthwise middle of the exterior. A disposable pants-type wearable article comprising a side seal portion in which both sides of an exterior body in a front body and both sides of an exterior body in a back body are joined, and a waist opening and a pair of left and right legs. ,
The exterior body of the front body and the back body has a waist portion which is a range in the front-rear direction corresponding to the side seal portion,
The exterior body in at least one of the front body and the back body has an intermediate portion positioned on the center side in the front-rear direction with respect to the waist portion,
The middle portion has an edge area along the leg opening,
The exterior body having the intermediate portion extends the elastic sheet expansion / contraction structure of the first aspect in the longitudinal direction, from the inside of the intermediate portion to the inside of the waist portion and in the width direction between the side seal portions. Is an expansion and contraction member provided in the width direction,
The shape of the sheet bonding portion in the edge area along the leg opening is different from the shape of the sheet bonding portion in the other area;
All the sheet junctions in the edge area along the leg opening and the other areas have a bonding reference diameter of 0.2 mm or more, and the maximum bonding reference diameter is 1 to 3 times the minimum value, and The circumferential length is 1 to 15 times the circumferential length of the circle having the bonding reference diameter as a diameter,
Disposable wear article characterized in that.

(Action effect)
The above-mentioned elastic member is suitable for the exterior body of the pants-type disposable wearing article as in this embodiment. In particular, an elastic sheet stretch structure is provided from the middle to the inside of the waist in the front and rear direction and between the side seals in the width direction, and the stretchability of the edge along the leg opening and the stretchability of the other area It is preferable to improve the fit around the legs and other areas by making the difference. In this case, since the shape of the sheet bonding portion in the edge region along the leg opening is different from the shape of the sheet bonding portion in the other region, welding failure may occur. However, by setting the bonding reference diameter and the circumferential length in the specific range as described above, welding that is less likely to cause welding defects can be performed with an appropriate pressure, as described in the first aspect.

<Fifth aspect>
The exterior body having the elastic sheet stretchable structure has a non-stretchable region at the widthwise intermediate portion, and a width direction range corresponding between the non-stretchable region and the side seal portion is the stretchable region.
The area ratio of the sheet bonding portion in the stretchable region is 0.5 to 1 times the area ratio of the sheet bonding portion in the non-stretchable region,
The boundary between the stretchable region and the non-stretchable region has a shape which is continuously shifted only to the side seal portion side from the end on the waist opening side toward the center in the front-rear direction of the disposable wearing article.
The disposable wearing article according to the fourth aspect.

(Action effect)
In the pants-type disposable wearing article, it is general to provide a non-stretchable area at the position of this embodiment. Therefore, in this case, as in the second aspect, it is desirable to shift the position of the boundary between the stretchable region and the non-stretchable region in the orthogonal direction. However, the boundary between the stretchable region and the non-stretchable region in this case extends in the front-rear direction of the pants-type disposable wearing article, so that the stretchable region on the waist opening side becomes short from the viewpoint of securing fit. Not desirable. Therefore, as in this embodiment, the position of the boundary between the stretchable region and the non-stretchable region is continuously shifted only to the side seal portion side from the end on the waist opening side toward the center in the front-rear direction of the disposable wearing article. Is preferred.

<Sixth aspect>
Supplying the elastic sheet in a state of being stretched in the MD direction between the first sheet layer and the second sheet layer;
An anvil roll having a large number of projections arranged in a predetermined pattern on the outer peripheral surface of the first sheet layer, the second sheet layer, and the elastic sheet in an extended state interposed therebetween; The first sheet layer and the second sheet layer are welded between the ultrasonic horns facing the outer peripheral surface of the anvil roll, and only the portion sandwiched between the multiple projections and the ultrasonic horns is welded to join the sheets. Forming a portion, bonding step,
Including
While forming sheet junctions with different joining reference diameters with one ultrasonic horn,
All of the sheet junctions formed by one ultrasonic horn have a junction reference diameter of 0.2 mm or more, the maximum junction reference diameter is 1 to 3 times the minimum value, and the circumferential length is the junction reference It is 1 to 15 times the length of the circumference of the circle whose diameter is the diameter,
A manufacturing method of an elastic member characterized by things.

(Action effect)
When forming a sheet | seat junction part by ultrasonic sealing, there exists an effect similar to a 1st aspect.

<Seventh aspect>
Supplying the elastic sheet in a state of being stretched in the MD direction between the first sheet layer and the second sheet layer;
An anvil roll having a large number of projections arranged in a predetermined pattern on the outer peripheral surface of the first sheet layer, the second sheet layer, and the elastic sheet in an extended state interposed therebetween; The first sheet layer and the second sheet layer are sandwiched between the plurality of projections and the opposing roll by passing between the outer circumferential surface of the anvil roll and the opposing roll opposed to each other by the heated anvil roll and the opposing roll. Bonding step to form a sheet bonding portion by welding only
Including
While forming a sheet joining portion having different joining reference diameters by the pair of anvil rolls and the opposing rolls,
The bonding reference diameter is 0.2 mm or more, the maximum value of the bonding reference diameter is 1 to 3 times the minimum value, and the circumferential length of all the sheet bonding portions formed by the pair of anvil rolls and the opposing rolls is 0.2 mm or more. 1 to 15 times the circumferential length of the circle whose diameter is the bonding reference diameter,
A manufacturing method of an elastic member characterized by things.

(Action effect)
When forming a sheet | seat junction part by heat sealing, there exists an effect similar to a 1st aspect.

  ADVANTAGE OF THE INVENTION According to this invention, when it has a sheet | seat junction part from which a shape differs, the welding defect becomes difficult to occur, etc. and an advantage is brought about.

It is a top view (inner surface side) of the underpants type disposable diaper of an unfolded state. It is a top view (outer surface side) of the underpants type disposable diaper of an unfolded 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 elastic region, (b) is a DD sectional view of (a), (c) is a sectional view in a mounted state, (d) is a sectional view in a natural length state. It is sectional drawing which shows roughly the principal part cross section of the exterior body expanded to a certain extent. (A) is a principal part top view of an elastic region, (b) is a DD sectional view of (a), (c) is a sectional view in a mounted state, (d) is a sectional view in a natural length state. It is a top view which shows various arrangements of a sheet | seat junction part. It is a top view of the expansion-contraction area | region of an unfolded state. It is a top view which expands and shows the principal part of the expansion-contraction area | region of an expansion | deployment state. It is a top view which expands and shows the principal part of the expansion-contraction area | region of a natural length state. (A) is DD sectional drawing of FIG. 12, (b) is sectional drawing in a natural length state. It is a top view of the expansion-contraction area | region of an unfolded state. It is a top view which expands and shows the principal part of the expansion-contraction area | region of an expansion | deployment state. It is a top view which expands and shows the principal part of the expansion-contraction area | region of a natural length state. It is a front view which shows only the principal part of a pants type disposable diaper. It is a front view which shows only the principal part of a pants type disposable diaper. It is a front view which shows only the principal part of a pants type disposable diaper. It is the schematic of an ultrasonic sealing apparatus. It is a top view which expands and shows the Q section of FIG. It is a top view which expands and shows the Q section of FIG. It is a top view which shows the various shapes of a sheet | seat junction part.

  Hereinafter, based on the example of the underpants-type disposable diaper shown by the attached drawing, the manufacturing method of an elastic member, a disposable wearing article, and an elastic member is explained in full detail. In addition, the dotted part in sectional drawing has shown joining means, such as a hot-melt-adhesive agent.

  1 to 6 show a pants-type disposable diaper. The code | symbol LD (vertical direction) has shown the front-back direction, and WD has shown the width direction. This pants-type disposable diaper (hereinafter, also simply referred to as a diaper) has an exterior body 20 forming a front body F and a back body B, and an interior body 10 fixed and integrated to the inner surface of the exterior body 20. The inner body 10 is formed by interposing an absorber 13 between the liquid-permeable top sheet 11 and the liquid-impermeable sheet 12. In manufacturing, after the back surface of the inner body 10 is joined to the inner surface (upper surface) of the outer body 20 by bonding means such as a hot melt adhesive, the inner body 10 and the outer body 20 are front body F and back body B Are folded at the center in the front-rear direction LD (longitudinal direction), which is the boundary between the two, and both sides thereof are joined to each other by heat welding or a hot melt adhesive, etc. It becomes a pants type disposable diaper in which a pair of leg openings were formed.

(Example of the structure of the interior body)
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, as shown in FIGS. It absorbs and holds the excretory fluid that has passed through the sheet 11. The planar shape of the inner body 10 is not particularly limited, but generally it is generally rectangular as shown in FIG.

  As the top sheet 11 that covers the front side (skin side) of the absorbent body 13, a non-woven or non-porous non-woven fabric, a porous plastic sheet, or the like is suitably used. The material fibers constituting the non-woven fabric may be synthetic fibers of olefin type such as polyethylene or polypropylene, polyester type, polyamide type etc., regenerated fibers such as rayon or cupra, natural fibers such as cotton, etc. Spunlace method Nonwoven fabrics obtained by an appropriate processing method such as a spun bond method, a thermal bond method, a meltblown method, a needle punch method or the like can be used.

  A liquid impermeable plastic sheet such as polyethylene or polypropylene can be used as the liquid impermeable sheet 12 covering the back side (non-skin contact side) of the absorbent body 13, and in particular, it has moisture permeability from the viewpoint of dripping prevention. For example, a microporous sheet obtained by 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 can be suitably used.

  The absorbent 13 is a known one, for example, a pile of pulp fibers, an assembly of filaments such as cellulose acetate, or a non-woven fabric, and is formed by mixing or fixing a superabsorbent polymer as necessary. Can be used. The absorbent body 13 can be packaged by a packaging sheet 14 having liquid permeability and liquid holding property, such as crepe paper, as necessary, for shape and polymer holding.

  The shape of the absorber 13 is formed in a substantially hourglass shape having a narrow portion 13N at the crotch portion which is narrower than the front and rear sides. The dimension of the constricted portion 13N can be determined as appropriate, but the longitudinal length of the constricted portion 13N can be about 20 to 50% of the total length of the diaper, and the width of the narrowest part is 40% of the total width of the absorbent 13 It can be about 60%. In the case of having such a constricted portion 13N, when the planar shape of the interior body 10 is substantially rectangular, the absorber 13 is not included in the portion corresponding to the constricted portion 13N of the absorber 13 in the interior body 10. An absorber side 17 is formed.

  The liquid impermeable sheet 12 is folded back on the both sides in the width direction of the absorber 13 together with the top sheet 11. As this liquid impermeable sheet 12, it is desirable to use an opaque sheet so as not to have brown color such as defecation and urine. As the opacification, a film formed by internally adding a pigment such as calcium carbonate, titanium oxide, zinc oxide, white carbon, clay, talc, barium sulfate or the like into a plastic and using it as a film is preferably used.

  On both sides of the interior body 10, solid gathers 90 fitted around the legs are formed. As shown in FIGS. 5 and 6, the three-dimensional gather 90 includes a fixing portion 91 fixed to the side of the back surface of the inner body 10, and the fixing portion 91 passing through the side of the inner body 10. Body 92 extending to the side of the surface of the body, and the front and rear ends of the body 92 are in a laid-down state by hot melt adhesive 95b or the like on the side of the surface (top sheet 11 in the illustrated example) It has a fixedly formed falling portion 93 and a free portion 94 formed non-fixed between the falling portions 93. Each of these parts is formed of a gather sheet 95 formed by folding a sheet such as non-woven fabric into a double sheet. The gather sheet 95 is attached over the entire front-rear direction of the inner body 10, the falling portions 93 are provided on the front and back sides of the non-absorbent side 17 and the free portions 94 are on both sides of the non-absorbent side 17 It is extended. Further, between the double gather sheets 95, a gather elastic member 96 is disposed at the tip of the free part or the like. The gather elastic member 96 is for raising the free portion 94 by an elastic contraction force as shown in FIG. 5 in the product state.

  The fixing structure of the gather elastic member 96 and the gather sheet 95 is not particularly limited. For example, as in the examples shown in FIGS. 5 and 6, except for the falling portion 93, the hot melt adhesive at the position of the gather elastic member 96 Although the gather elastic member 96 is adhesively fixed to the gather sheet 95 and the opposite surface of the gather sheet 95 is joined, in the falling portion 93, there is no hot melt adhesive at the position of the gather elastic member 96, and therefore gather elastic It is possible to adopt a structure in which the member 96 and the gather sheet 95 are not bonded and the opposite surface of the gather sheet 95 is not joined at the position where the gather elastic member 96 is present.

  As the gather elastic member 96, materials such as styrene rubber, olefin rubber, urethane rubber, ester rubber, polyurethane, polyethylene, polystyrene, styrene butadiene, silicone, polyester and the like which are usually used can be used. Moreover, in order to make it hard to see from the outside, it is preferable to arrange the thickness at 925 dtex or less, the tension at 150 to 350%, and the interval at 7.0 mm or less. As the gather elastic member 96, in addition to the elongated shape as shown in the illustrated example, a tape-like member having a certain width can also be used.

  The material fibers constituting the above-mentioned gather sheet 95 are also synthetic fibers such as olefins such as polyethylene or polypropylene, polyesters and polyamides, as well as synthetic fibers such as rayon and cupra, natural fibers such as cotton, etc. Although non-woven fabrics obtained by an appropriate processing method such as a spun bond method, a thermal bond method, a meltblown method, a needle punch method or the like can be used as the fiber, in particular, the basis weight is It is preferable to use a non-woven fabric which is excellent in breathability by suppressing. Furthermore, as for the gather sheet 95, silicone type, paraffin metal type, alkylchromic chloride type water repellent, etc. in order to prevent permeation of urine and the like, to prevent run-out and to improve the feel (dry feeling) to the skin. It is desirable to use a water repellent treated non-woven fabric coated with.

  As shown in FIGS. 3 to 6, the inner surface of the inner body 10 is joined to the inner surface of the outer body 20 by a hot melt adhesive or the like in the inner and outer fixed area 10B (hatched area). The inside and outside fixed area 10B can be appropriately determined, and can be substantially the entire width direction WD of the inner body 10. However, it is preferable that both widthwise end portions are not fixed to the outer body 20.

(Example of structure of exterior body)
The exterior body 20 has at least a waist T of a front body F and a waist T of a rear body B. In the illustrated example, between the waist T of the front F and the waist T of the rear B It further has an intermediate portion L which is a range in the front-rear direction of. As shown in the illustrated example, the exterior body 20 may be located at the center side in the width direction from the side edge of the interior body 10 in the crotch portion, or may be located outside in the width direction.

  And in the exterior body 20 of the illustrated example, as shown in FIG. 2 and FIG. 4 to FIG. 6 except for the middle in the front-rear direction of the middle portion L, between the first sheet layer 20A and the second sheet layer 20B. The elastic sheet 30 is interposed, and as shown in FIGS. 7 and 9 etc., the first sheet layer 20A and the second sheet layer 20B are elastic at a large number of sheet bonding portions 40 arranged at intervals. The elastic sheet stretchable structure 20 </ b> X is joined through the joining hole 31 penetrating the sheet 30. The area having the elastic sheet stretch structure has a stretch area which is shrunk in the width direction by shrinkage of the elastic sheet and is stretchable in the width direction (that is, the stretch direction ED is the width direction WD of the diaper). doing.

  The planar shape of the exterior body 20 is formed by concave line around the leg 29 so that the widthwise side edges of the middle portion L respectively form a leg opening, and has a shape resembling an hourglass as a whole. The exterior body 20 may be formed separately in the front body F and the back body B, and may be disposed so as to be separated in the crotch region in the front-rear direction LD of the diaper.

  Although the form shown in FIG.1 and FIG.2 is a form which provides the expansion-contraction structure by the conventional elongate waist elastic member 24, without providing the elastic sheet expansion-contraction structure 20X in the waist end part 23, an elastic sheet expansion-contraction structure 20X may be extended to the waist end 23. 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 LD, and provides an elastic force so as to tighten the circumference of the trunk of the body. The waist elastic members 24 are not arranged substantially as one bundle at close intervals, but three or more at intervals of about 3 to 8 mm in the front-rear direction so as to form a predetermined stretch zone. , Preferably five or more. Although the extension rate at the time of fixation of the waist part elastic member 24 can be determined suitably, in the case for normal adults, it can be made into about 230 to 320%. Although a rubber thread is used as the waist portion elastic member 24 in the illustrated example, for example, another elongated elastic member such as a plain rubber may be used. Although not shown, the elastic sheet 30 may be provided at the waist end 23, and an elongated waist elastic member 24 may be provided at a position overlapping with the elastic sheet 30 so as to have an elastic structure by both elastic members. Further, in the illustrated embodiment, the stretchable region of the elastic sheet stretchable structure 20X exists up to the edge region 82 of the leg opening in the exterior body 20. For this reason, the edge region 82 of the leg opening in the exterior body 20 is not provided with an elongated elastic member extending along the leg opening, but at a position overlapping the elastic sheet 30 in the edge region 82 or Instead of the elastic sheet 30 in the edge area 82, an elongated elastic member may be provided.

  As another form, although not shown, the elastic sheet stretchable structure 20X is not provided at the intermediate portion L between the waist T of the front body F and the waist T of the back body B, or the front body An elastic sheet stretchable structure 20X is continuously provided in the front-rear direction LD from the inside of the waist portion T of F through the middle portion L to the inside of the waist portion T of the back body B, or any one of the front body F and the back body B An appropriate deformation is also possible such as providing the elastic sheet stretchable structure 20X only in the above.

(Stretch area)
The area | region which has the elastic sheet expansion-contraction structure 20X in the exterior body 20 has an expansion-contraction area | region which can expand-contract in the width direction WD. In the elastic region 80, the elastic sheet 30 is contracted in the width direction WD by the contraction force of the elastic sheet 30, and is extensible in the width direction WD. More specifically, in a state in which the elastic sheet 30 is expanded in the width direction WD, the elastic sheet 30 is spaced apart in the width direction WD and the longitudinal direction LD orthogonal to this (the direction LD orthogonal to the expansion and contraction direction). The first sheet layer 20A and the second sheet layer 20B are bonded through the bonding holes 31 to form a large number of sheet bonding portions 40, thereby forming the elastic sheet expansion and contraction structure 20X. Are arranged uninterruptedly in the width direction WD, and the sheet bonding portion 40 is arranged such that the first sheet layer 20A and the second sheet layer 20B are contracted by the contraction force of the elastic sheet 30 to form the contraction ridge 25. Such elasticity can be imparted by this.

  In the stretchable area 80, even if the elastic sheet 30 has a portion 32 linearly continuous along the width direction WD as shown in FIGS. 7 and 9, the example shown in FIG. 11 and FIG. It does not have to have as an example.

  As shown in FIGS. 7 (d), 9 (d) and 14 (b), in the natural length state, the first sheet layer 20A and the second sheet layer 20B between the sheet bonding portions 40 are mutually stretched. The contraction ridges 25 which expand in the separating direction are formed, and the contraction ridges 25 extending in the front-rear direction LD are formed, and even though the contraction ridges 25 are stretched in the width direction WD to some extent, they remain. Further, as in the illustrated embodiment, the first sheet layer 20A and the second sheet layer 20B are not joined to the elastic sheet 30 except at least between the first sheet layer 20A and the second sheet layer 20B in the sheet joining portion 40. 7 (c) and 9 (c) assuming the mounted state, and FIGS. 7 (a) and (b) and FIG. 9 (a) 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 bonding hole 31 in the elastic sheet 30 and the sheet bonding portion 40, and the material of the elastic sheet 30 is a non-porous film or sheet Even if there is, air permeability is added by this gap. In particular, in the case where the elastic sheet 30 has the portion 32 linearly continuous along the width direction WD, in the natural length state, the joint hole 31 is narrowed due to the further contraction of the elastic sheet 30, and the joint hole is formed. In the case where a gap is hardly formed between the sheet 31 and the sheet bonding portion 40, and the elastic sheet 30 does not have a linearly continuous portion along the width direction WD, the bonding hole 31 and the sheet bonding portion A gap remains with 40.

  It is desirable that the maximum elongation in the width direction WD of the stretchable region 80 be 190% or more (preferably 200 to 220%). The maximum elongation of the expansion and contraction region 80 is substantially determined by the expansion rate of the elastic sheet 30 at the time of manufacture, but is basically reduced by the factor that inhibits the contraction in the width direction WD. The main factor of such an inhibition factor is the ratio of the length L of the sheet bonding portion 40 to the unit length in the width direction WD, and the maximum elongation decreases as the ratio increases. In a normal case, since the length L of the sheet bonding portion 40 has a correlation with the area ratio of the sheet bonding portion 40, the maximum elongation of the stretchable region 80 can be adjusted by the area ratio of the sheet bonding portion 40.

  The tensile stress of the stretchable area 80 is mainly an elastic sheet when the elastic sheet 30 has a portion 32 linearly continuous along the width direction WD as in the example shown in FIGS. 7 and 9. Adjusting by the sum (equal to the spacing 31d of the bonding holes) of the orthogonal dimension 32w of the portion 32 (see FIGS. 7A and 9A) in which the 30 is linearly continuous along the width direction WD it can. On the other hand, as in the example shown in FIG. 11 and the example shown in FIG. 15, when the elastic sheet 30 does not have a portion which continues linearly along the width direction WD, the non-bonding bands 51 and 52 are continuous. It can be adjusted by the crossing angle formed by the direction and the expansion / contraction direction ED. In the normal case, the acute angle side intersection angles θ1 and θ2 formed by the continuous direction of the non-bonding bands 51 and 52 and the expansion / contraction direction ED in the unfolded state are larger than 0 degrees It is preferable to set it as 45 degrees or less, especially 10 to 30 degrees.

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

  Thus, since the maximum elongation and expansion stress of the stretchable area 80 can be adjusted by the area of the sheet bonding portion 40, as shown in FIGS. 1 and 2, a plurality of area ratios of the sheet bonding portion 40 in the stretchable area 80 are different. The region of 、 can be provided to change the fit according to the site. In the embodiment shown in FIGS. 1 and 2, the edge area 82 of the leg opening has a high area ratio of the sheet bonding portion 40 as compared with the other areas, and hence the expansion stress is weak and becomes an area flexible and stretchable. There is.

  The shapes of the individual sheet bonding portions 40 and the bonding holes 31 in the natural length state can be determined as appropriate, but may be a perfect circle, an ellipse, a triangle, a rectangle, a polygon such as a rhombus, or a convex lens shape, a concave lens shape, a star shape It can be in any shape such as a shape or a cloud shape. The dimensions of the individual sheet joints are not particularly limited, but the maximum length 40y (approximately equal to the dimension 31y in the orthogonal direction of the joint holes 31) is 0.5 to 3.0 mm, particularly 0.7 to 1.1 mm. The maximum width 40x is preferably 0.1 to 3.0 mm, particularly 0.1 to 1.1 mm in the case of a long shape in the direction XD orthogonal to the expansion and contraction direction.

The size of each sheet bonding portion 40 may be appropriately determined, but if the size is too large, the hardness of the sheet bonding portion 40 has a large influence on the feel, and if it is too small, the bonding area is small and the materials are sufficiently adhered. In general, the area of each sheet bonding portion 40 is preferably about 0.14 to 3.5 mm ² because it can not be done. The area of the opening of each bonding hole 31 may be equal to or larger than the sheet bonding portion because the sheet bonding portion is formed through the bonding holes 31, but it is about 1 to 1.5 times the area of the sheet bonding portion Is preferred. In addition, the area of the opening of the bonding hole 31 means a value in a state of not only the elastic film 30 alone but integrated with the first sheet layer 20A and the second sheet layer 20B and in a natural length state. When the area of the opening 31 is not uniform in the thickness direction, for example, the front and back of the elastic film 30 are different, this means the minimum value.

  Although the plane arrangement of the sheet bonding portion 40 and the bonding holes 31 can be appropriately determined, a plane arrangement which is regularly repeated is preferable, and an oblique lattice shape as shown in FIG. 10 (a) or FIG. 10 (b) Hexagonal grid as shown (these are also referred to as zigzag), square grid as shown in FIG. 10 (c), rectangular grid as shown in FIG. 10 (d), as shown in FIG. 10 (e) Parallel lattice (in which two groups are provided so that a group of many parallel oblique rows intersect each other as shown) or the like (these are inclined at an angle of less than 90 degrees with respect to the expansion and contraction direction) And the group of sheet bonding portions 40 (the arrangement of group units may be regular or irregular, and may be a pattern, characters, etc.) are regularly repeated. You can also

  It is preferable that the arrangement pattern of the sheet bonding portion 40 of the stretchable area 80 is as shown in the example shown in FIG. 9, the example shown in FIG. 11, and the example shown in FIG. That is, in these examples, in the expansion / contraction area 80, an acute angle (sharp angle side intersection angle θ1) with respect to the expansion / contraction direction ED as non-bonding bands 51, 52 in which a portion without the sheet bonding portion 40 is continuous The first non-bonding zone 51 linearly continuous along the first direction 51d intersecting with is repeatedly present at an interval in a direction orthogonal to the first direction 51d. Further, a large number of sheet bonding portions 40 and bonding holes 31 are provided at intervals between adjacent first non-bonding bands 51 in the stretchable region 80. Characteristically, a unit structure including a plurality of first non-bonding bands 51 having different first widths 51w determined as widths in a direction orthogonal to the first direction 51d is orthogonal to the first direction 51d in the stretchable region 80. It exists repeatedly in the direction.

  As described above, when the unit structure including the plurality of first non-bonding bands 51 having different first widths 51 w is repeatedly present in the direction orthogonal to the first direction 51 d in the stretchable area 80, the inside of the first non-bonding bands 51 In the continuous portion of the elastic sheet 30, the same magnitude change in width is formed. That is, if the width 51w of the first non-bonding band 51 is narrow, the width of the continuous portion of the elastic sheet 30 inside is also narrow, and if the width 51w of the first non-bonding band 51 is wide, the continuous of the elastic sheet 30 inside The width of the department also increases. Then, when there is a change in the first width 51w in the continuous portion of the elastic sheet 30 in the first non-bonding zone 51, the continuous portion of the elastic sheet 30 in the wide first non-bonding zone 51 and the narrow width (1) Both continuous portions of the elastic sheet 30 in the non-bonding zone 51 are visually emphasized, so that even in the natural length state (see FIGS. 13 and 17), the expansion and contraction region 80 is in a partially expanded state Even if there is, it will have a beautiful appearance with diagonal stripes. Moreover, since the size of the contraction ridge 25 in the first non-bonding zone 51 changes in accordance with the first width 51 w of the first non-bonding zone 51 in a state of contraction to a certain extent, oblique stripes due to the influence of the contraction ridge 25 Patterns will appear more clearly.

  The unit structure described above is not limited by the magnitude of the width 51 w as long as it includes a plurality of first non-junction bands 51 having different first widths 51 w. The width 51w is preferably 1.2 to 60 times larger and 0.01 to 0.8 times smaller than the nearest first non-bonding zone 51 of width 51w.

  Furthermore, as long as the unit structure described above includes a plurality of first non-junction bands 51 having different first widths 51 w, the first widths 51 w of all the first non-junction bands 51 may be different, as shown in FIG. As described above, the first width 51 w of some of the plurality of first non-junction bands 51 may be different from the first width 51 w of the other one or more first non-junction bands 51.

  Even if an oblique stripe pattern along the first direction 51 d by the contraction ridge 25 of the first non-bonding band 51 and the continuous part of the elastic sheet 30 inside thereof appears in the expansion and contraction area 80, the other expansion and contraction area 80 If the diagonal stripe pattern along the diagonal direction is more strongly recognized, the diagonal stripe pattern due to the continuous portion of the contraction ridge 25 of the first non-bonding zone 51 and the elastic sheet 30 inside thereof may be inconspicuous. On the other hand, the maximum value of the first width 51w in the first non-bonding zone 51 is the maximum value of the width in the direction orthogonal to the continuous direction in all the non-bonding zones 51 and 52 having different inclination directions and in common. This is preferable because in the stretchable area 80, the diagonal stripes formed by the contraction ridges 25 of the first non-bonding band 51 and the continuous portion of the elastic sheet 30 inside the first bonding bands 51 become more strongly visible. In this case, the maximum value of the first width 51w in the first non-bonding zone 51 can be determined as appropriate, but it is 0.01 to 9 times the nearest first non-bonding zone 51 of width 51w. preferable. Although all the non-bonding bands 51 and 52 including the first non-bonding band 51 are not limited in width in the direction orthogonal to the continuous direction, they are within the range of 0.3 to 50 mm in the normal case. Is preferred. Needless to say, the width of the non-bonding bands 51 and 52 in the direction orthogonal to the continuous direction is the first width 51 w in the first non-bonding band 51 and is a portion that is linearly continuous. Because it is equal width.

  The first interval 51s defined as an interval in a direction orthogonal to the first direction 51d in the adjacent first non-bonding bands 51 can be appropriately determined. Therefore, the first interval 51s may be the same as, wider than, or smaller than the first width 51w of the adjacent first non-bonding bands 51. One preferable example is a mode in which the maximum value of the first width 51 w in the first non-bonding zone 51 in the unit structure is smaller than the maximum value of the first interval 51 s. Thus, by forming the wide interval portion in the unit structure, the diagonal stripe pattern by the continuous ridge of the contraction ridge 25 of the first non-bonding zone 51 and the elastic sheet 30 inside thereof becomes more visible . In this case, the maximum value of the first width 51w in the first non-bonding zone 51 can be appropriately determined, but is preferably 0.01 to 9 times the maximum value of the first interval 51s. In addition, although the space | interval of the direction orthogonal to the continuous direction in all the no bonding bands 51 and 52 containing the 1st no bonding band 51 is not specifically limited, It is in the range of 0.3-50 mm in the case of usual. Is preferred. Needless to say, the distance between the non-bonding bands 51 and 52 in the direction orthogonal to the continuous direction is the first distance 51s in the first non-bonding band 51 and is equal to the continuous direction. .

  In the stretchable region 80, as the non-bonding bands 51 and 52, a second continuous straight line is formed along a second direction 52d intersecting an acute angle (the acute angle side crossing angle θ2) with respect to the stretch direction ED other than the first direction 51d. The two non-bonding bands 52 may be repeatedly present at intervals in the direction orthogonal to the second direction 52 d, or the second non-bonding bands 52 may not exist. In one preferable embodiment having the second non-bonding zone 52, the non-bonding zones 51 and 52 are formed in a diagonal grid shape in the expansion and contraction region 80, and the first non-bonding zone 51 is a non-junction It is a portion which is continuous in one direction in the bands 51, 52, and the second non-bonding zone 52 is a portion which is continuous in the other direction in the non-bonding zones 51, 52 in the oblique grid shape. In this case, in the first direction 51 d and the second direction 52 d, the positive and negative inclinations with respect to the expansion and contraction direction ED are opposite to each other. Incidentally, even in the form without the non-bonding bands 51 and 52 continuous in the width direction WD (stretching direction ED) as in the example shown in FIG. 11 and the example shown in FIG. The stretchability in the stretchable region 80 is sufficiently ensured by the acute angle side crossing angles θ1 and θ2 of the first direction 51d and the second direction 52d with respect to the stretch direction ED being 5 to 45 degrees, particularly 10 to 30, respectively. Can.

  However, when the diagonal stripe pattern along the oblique direction of the second non-bonding zone 52 is more strongly recognized in the same stretchable area 80, the contraction ridge 25 of the first non-bonding zone 51 and the continuous portion of the elastic sheet 30 inside thereof There is a risk that the diagonal stripes due to Therefore, when the second non-bonding zone 52 is provided as in the example shown in FIG. 15, all the second widths 52w defined as widths in the direction orthogonal to the second direction in the second non-bonding zone 52 are the same, or It is desirable to arrange the sheet bonding portion 40 so as not to have the second non-bonding band 52. As a result, in the stretchable area 80, the diagonal stripes formed by the contraction ridges 25 of the first non-bonding band 51 and the continuous portion of the elastic sheet 30 inside the first bonding bands 51 become more visible.

  On the other hand, the sheet bonding portion 40 is aligned in the first direction 51 d between the adjacent first non-bonding bands 51. In this case, for example, as shown in FIG. When the acute angle side crossing angle θ3 of the longitudinal direction with respect to the direction orthogonal to the direction ED is 10 degrees or less and the maximum dimension 40e of the stretching direction ED is a slender shape of 0.1 to 0.4 mm, the first bonding-free zone Since the dimension of the expansion-contraction direction ED of 51 can be ensured larger and the fall of elasticity can be suppressed, it is preferable.

  Further, as in the example shown in FIG. 11, the wide first non-bonding zone 51 where the first width 51 w is maximum and the narrow first non-bonding zone 51 where the first width 51 w is narrower When a plurality of adjacent ones are included in the direction orthogonal to the first direction 51d, the acute angle side crossing angle in the longitudinal direction with respect to the second direction 52d is within 5 degrees between the adjacent wide first non-bonding bands 51, And it is preferable that the elongate sheet | seat junction part 40 which makes the largest dimension 40f of the direction orthogonal to the longitudinal direction which is 0.1-0.4 mm is spaced apart and arrange | positioned in the 1st direction 51d. Further, between the adjacent narrow first non-bonding bands 51, the acute angle side crossing angle θ3 in the longitudinal direction with respect to the first direction 51d is 45 degrees or more, and the maximum dimension 40g in the direction orthogonal to the longitudinal direction is 0. It is preferable that an elongated sheet bonding portion 40 having a length of 1 to 0.4 mm be aligned at intervals in the first direction 51 d. With such a shape and arrangement of the sheet bonding portion 40, the contraction ridges 25 of the first non-bonding band 51 and the continuous portion of the elastic sheet 30 inside thereof are particularly visually emphasized with less area of the sheet bonding portion 40. Become so.

  The row (the row in the continuous direction of the non-bonding bands 51 and 52) of the sheet bonding portion 40 located between the non-bonding bands 51 and 52 adjacent to each other may be one or more. Also, although it is preferred that the spacing of the sheet joints 40 in the row direction be regular, not all spacings need be constant, and some spacings may be different.

(Non-stretchable area)
A non-stretchable region 70 can be provided on at least one side in the width direction of the stretchable region 80 in the region having the elastic sheet stretchable structure 20X in the exterior body 20, as shown in FIG. The non-stretchable area 70 means that the maximum elongation in the stretch direction is 120% or less. The maximum elongation of the non-stretchable region 70 is preferably 110% or less, and more preferably 100%. The arrangement of the stretchable region 80 and the non-stretchable region 70 can be determined as appropriate. In the case of the exterior body 20 of the underpants type disposable diaper as in this example, a portion overlapping with the absorber 13 is a region that does not require expansion and contraction, so a part or all of the portion overlapping with the absorber 13 It is preferable to make the non-stretchable region 70 preferably) to include substantially the whole of the inner and outer fixation regions 10B. Of course, the non-stretchable region 70 can be provided from the region overlapping the absorber 13 to the region not overlapping the absorber 13 located in the width direction WD or the longitudinal direction LD, and the non-stretch region only in the region not overlapping the absorber 13 70 can also be provided.

  The shape of each sheet bonding portion 40 in the non-stretchable region 70 is not particularly limited, and can be appropriately selected from the same shape as that described in the stretchable region 80 section.

Moreover, although the area ratio of the sheet bonding portion 40 in the non-stretchable region 70 and the area of each sheet bonding portion 40 can be appropriately determined, the area of each sheet bonding portion 40 is usually within the following range. It is preferable that the non-stretchable region 70 is hard and hard due to the small size and the low area ratio of the sheet bonding portion 40.
Area of sheet bonding portion 40: 0.10 to 0.75 mm ² (particularly 0.10 to 0.35 mm ² )
Area ratio of sheet bonding portion 40: 4 to 13% (especially 5 to 10%)

  The non-stretchable region 70 can be formed by closely arranging the sheet bonding portions 40 so that the first sheet layer and the second sheet layer do not shrink due to the contraction force of the elastic sheet 30 to form wrinkles. As a specific example of the formation method of the non-stretchable area | region 70, what is shown by patent 5980355, patent 5918877, patent 5980367, patent 6049228, for example can be mentioned.

  By changing the area ratio of the sheet bonding portion 40, the expansion and contraction characteristics can be changed. However, the position at which the area ratio of the sheet bonding portion 40 changes rapidly, that is, the boundary between the stretchable region 80 and the non-stretchable region 70 along the orthogonal direction XD orthogonal to the stretch direction ED from one end to the other end When welding is performed, the linear pressure changes rapidly at the boundary between the stretchable area 80 and the non-stretchable area 70 during welding. Such a rapid change in linear pressure may lead to premature wear and breakage of equipment such as an anvil roll. Therefore, as shown in FIGS. 2 and 18 to 20, when the area ratio of the sheet bonding portion 40 in the stretchable region 80 is 0.5 to 1 times the area ratio of the sheet bonding portion 40 in the non-stretchable region 70. Preferably, the boundary 71 between the stretchable region 80 and the non-stretchable region 70 is shaped so as to be continuously shifted only to one side in the stretch direction ED as it goes from one end to the other end. As a result, since there is no rapid change in linear pressure at the time of welding, there is little possibility of leading to premature wear and breakage of equipment such as an anvil roll.

  However, in the pants-type disposable wearing article, the boundary 71 between the stretchable area 80 and the non-stretchable area 70 continuously extends from the end on the waist opening side toward the center of the longitudinal direction LD of the disposable wearing article. It is not preferable from the viewpoint of securing the fit that the stretchable region 80 on the waist opening side is shortened if it has a shape that is only shifted. Therefore, as shown in the illustrated example, the position of the boundary 71 between the stretchable region 80 and the non-stretchable region 70 is continuously from the end on the waist opening side toward the center of the longitudinal direction LD of the disposable wearing article. It is preferable to shift only to

  The boundary 71 between the stretchable region 80 and the non-stretchable region 70 may be linear as in the example shown in FIGS. 2, 18 and 20, or curved as in the example shown in FIG. It is also good. As in the example shown in FIG. 20, in the case where the recess 72 recessed toward the crotch is formed in the waist opening side of the non-stretchable region 70 and this recess 72 is used as the stretchable region 80, the stretch direction of the recess 72 The boundaries 71 of the stretchable area 80 and the non-stretchable area 70 are produced on both sides of the ED. Therefore, it is desirable that the boundary 71 between the stretchable region 80 and the non-stretchable region 70 be obliquely oriented in this portion as well.

(Joint structure of sheet joint)
When the first sheet layer 20A and the second sheet layer 20B in the sheet bonding portion 40 are bonded through the bonding holes 31 formed in the elastic sheet 30, at least the first sheet layer 20A and the second sheet layer 20 in the sheet bonding portion 40. It is desirable that the first sheet layer 20A and the second sheet layer 20B are not joined to the elastic sheet 30 except between the sheet layers 20B.

  When the first sheet layer 20A and the second sheet layer 20B are welded through the bonding holes 31 of the elastic sheet 30 at the sheet bonding portion 40, both the first sheet layer 20A and the second sheet layer 20B melt at the sheet bonding portion 40. Even if it is solidified, only one of the first sheet layer 20A and the second sheet layer 20B may be melted and solidified in the sheet bonding portion 40. Furthermore, the melted and solidified material of the elastic sheet 30 may be sandwiched in the sheet bonding portion 40.

  Even if the first sheet layer 20A and the second sheet layer 20B are uniformly melted and solidified throughout the thickness direction and the planar direction of the sheet bonding portion 40 as in the example shown in FIG. (C) may be solidified and solidified nonuniformly as shown by the gradation of a dot pattern. For example, the degree of melting of the first sheet layer 20A and the second sheet layer 20B may be lower toward the outside in the thickness direction of the sheet bonding portion 40 as in the example illustrated in FIG. 8B. In this state, almost all the fibers of the first sheet layer 20A and the second sheet layer 20B are not melted on the surface of the sheet bonding portion 40, and the first sheet layer 20A and the second on the surface of the sheet bonding portion 40. In a state in which the melted and solidified material of the sheet layer 20B is mixed with unmelted fibers, and in which the fibers of the first sheet layer 20A and the second sheet layer 20B are melted throughout the thickness direction of the sheet bonding portion 40 It includes conditions of varying degrees.

  The first sheet layer 20A and the second sheet layer 20B are formed of the sheet bonding portion 40 as shown in FIG. 8C, with or without a change in the degree of melting in the thickness direction of the sheet bonding portion 40. The degree of melting may be lower toward the peripheral side. In this state, almost all the fibers of the first sheet layer 20A and the second sheet layer 20B are not melted at the peripheral portion of the sheet bonding portion 40 (however, the melted solidified material of the elastic sheet 30 described later is an adhesive) (Only when it intervenes as), a state in which the melted and solidified material of the first sheet layer 20A and the second sheet layer 20B and mixed fibers are not mixed at the periphery of the sheet bonding portion 40, and the plane of the sheet bonding portion 40 The state in which the degree of melting changes although the fibers of the first sheet layer 20A and the second sheet layer 20B are melted in the entire direction is included.

  In addition, in these states, in order for the fibers of the first sheet layer 20A and the second sheet layer 20B to melt, in addition to melting the entire fibers, the core of the fibers (not only the core in the composite fiber but also the single component fiber In this case, the central portion (including not only the sheath in the composite fiber but also the surface side portion of the monocomponent fiber) is melted.

  Further, in a state where the melted and solidified material of the elastic sheet 30 remains in the sheet bonding portion 40, the first sheet layer 20A or the melted and solidified layer thereof and the second sheet layer 20B or the melted and solidified layer thereof A state in which the first sheet layer 20A and the second sheet layer 20B are mixed with those that solidify and solidify, and a state in which the first sheet layer 20A and the second sheet layer 20B do not melt and solidify. And the remaining fibers (including the core) of the first sheet layer 20A and the second sheet layer 20B in the direction of melting and solidification are included to some extent.

  The state in which the melted and solidified material of the elastic sheet 30 remains in the sheet bonding portion 40 is determined 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 sheet 30. The elastic sheet 30 is sandwiched between the sheet layer 20A and the second sheet layer 20B, and a portion to be the sheet bonding portion 40 is pressurized and heated, and at least one of the first sheet layer 20A and the second sheet layer 20B and the elastic sheet 30. By melting.

  In this case, the melting point of the elastic sheet 30 is preferably about 80 to 145 ° C., and the melting points of the first sheet layer 20A and the second sheet layer 20 B are preferably about 85 to 190 ° C., particularly preferably about 150 to 190 ° C. The difference between the melting point of the first sheet layer 20A and the second sheet layer 20B and the melting point of the elastic sheet 30 is preferably about 60 to 90 ° C. Moreover, it is preferable to make heating temperature into about 100-150 degreeC.

  FIG. 21 shows an example of a suitable ultrasonic sealing device. In this ultrasonic sealing device, when forming the sheet bonding portion 40, the first sheet layer 20A, between the anvil roll 60 having the projections 60a formed in the pattern of the sheet bonding portion 40 on the outer surface, and the ultrasonic horn 61, The elastic sheet 30 and the second sheet layer 20B are fed. At this time, for example, the feed drive roll 63 and the nip roll 62 are set by making the feed transfer speed by the feed drive roll 63 and the nip roll 62 of the elastic sheet 30 on the upstream side slower than the transfer speeds of the anvil roll 60 and the ultrasonic horn 61 and thereafter. The elastic sheet 30 is stretched in the MD direction (machine direction, flow direction) to a predetermined elongation rate in a path from the nip position by the to the seal position by the anvil roll 60 and the ultrasonic horn 61. The extension ratio of the elastic sheet 30 can be set by selecting the speed difference between the anvil roll 60 and the feed driving roll 63, and can be set, for example, to about 300% to 500%. 62 is a nip roll.

  The first sheet layer 20A, the elastic sheet 30, and the second sheet layer 20B, which are fed between the anvil roll 60 and the ultrasonic horn 61, are laminated in this order with the protrusion 60a and the ultrasonic horn 61. Heating is performed by the ultrasonic vibration energy of the ultrasonic horn 61 while pressing between them to melt only the elastic sheet 30 or melt at least one of the first sheet layer 20A and the second sheet layer 20B and the elastic sheet 30. At the same time as forming the bonding holes 31 in the elastic sheet 30, the first sheet layer 20A and the second sheet layer 20B are bonded through the bonding holes 31. Therefore, in this case, the area ratio of the sheet bonding portion 40 is selected by selecting the size, shape, separation distance, arrangement pattern of the roll length direction and roll circumferential direction, and the like of the projection 60 a of the anvil roll 60. Can.

  The reason why the bonding hole 31 is formed is not necessarily clear, but it is considered that the portion of the elastic sheet 30 corresponding to the projection 60 a of the anvil roll 60 is melted and separated from the periphery to open the hole. At this time, portions of the elastic sheet 30 between adjacent bonding holes 31 aligned in the expansion / contraction direction ED are as shown in FIGS. 7 (a) and (b) and FIGS. 9 (a) and (b), and 12 and 13. In order to be cut off from the parts on both sides in the expansion and contraction direction by the bonding hole 31 and lose the support on both sides in the contraction direction, the direction LD orthogonal to the expansion and contraction direction ED is within a range where continuity in the direction orthogonal to the contraction direction can be maintained. The joint hole 31 is contracted in the expansion / contraction direction center side toward the center side in the expansion / contraction direction, and the bonding hole 31 expands in the expansion / contraction direction ED.

  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 non-woven fabric in which at least a part of the fibers can be welded (that is, contains a thermoplastic resin component). For example, synthetic fibers of olefins such as polyethylene and polypropylene, polyesters, polyamides, etc., mixed fibers in which two or more of them are used, or composite fibers containing two or more of these (eg sheath component is melted) Core-sheath type) and the like can be exemplified. Furthermore, the non-woven fabric may be produced by any processing.

The fiber bonding method in the non-woven fabric may be any of chemical means such as adhesive and solvent, physical means such as heating, or so-called entanglement, for example, spunlace method, spunbond method, thermal bond method, meltblown method, A needle punch method, an air through method, a point bond method or the like can be adopted. When using a nonwoven fabric, it is preferable to make the fabric weight into about 10-25 g / m < ² >. In addition, 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 sheet of material is folded back to be opposed. For example, as shown in the illustrated embodiment, at the waist end 23, the component positioned outside is the second sheet layer 20B, and the folded portion 20C formed by being folded back to the inner surface at the waist opening edge is the first sheet layer 20A. The elastic sheet 30 is interposed between the elastic sheet 30 and the first sheet layer 20A, and the second sheet layer 20B is an elastic sheet 30 interposed therebetween. It can be intervened. Of course, the constituent of the first sheet layer 20A and the constituent of the second sheet layer 20B are individually provided over the entire longitudinal direction LD, and the constituent of the first sheet layer 20A and the second sheet are not folded. The elastic sheet 30 can be interposed between the components of the layer 20B.

  The elastic sheet 30 is not particularly limited, and as long as it is a thermoplastic resin sheet having elasticity by itself, it may be an elastic nonwoven fabric as well as an elastic film. Further, as the elastic sheet 30, in addition to the non-porous sheet, a sheet in which a large number of holes and slits are formed for ventilation can be used. In particular, the tensile strength in the width direction WD (stretching direction ED, MD direction) is 8 to 25 N / 35 mm, the tensile strength in the front-rear direction LD (direction XD orthogonal to the stretching direction, CD direction) is 5 to 20 N / 35 mm, width direction It is preferable that the elastic sheet 30 has a tensile elongation of 450 to 1050% in WD and a tensile elongation of 450 to 1400% in the longitudinal direction LD. The thickness of the elastic sheet 30 is not particularly limited, but preferably about 20 to 40 μm.

(Combination of sheet joints of different shapes)
In the region having the elastic sheet stretch structure 20X, sheet junctions 40 having different shapes can be provided in order to change the stretch characteristics and the appearance. For example, although the sheet bonding portion 40 of the stretchable area 80 in the example shown in FIG. 11 includes rectangular sheet bonding portions 40 having different orientations, sheet bonding portions 40 having such different orientations also have different shapes. Part 40 is included. Further, although the sheet bonding portion 40 of the stretchable area 80 in the example shown in FIG. 15 includes rectangular sheet bonding portions 40 having different lengths, the sheet bonding portions 40 having such different lengths also have different shapes. The sheet joint portion 40 is included. Furthermore, even when the shape of the sheet bonding portion 40 in the stretchable region 80 and the shape of the sheet bond portion 40 in the non-stretchable region 70 are different, it goes without saying that the region with the elastic sheet stretch structure 20X has a different shape in the sheet bonding portion 40. It is included in having.

  In the case of the underpants type disposable wearing article as illustrated, the elastic sheet stretchable structure 20X is provided from the middle portion L to the waist portion T in the front-rear direction LD and between the side seal portions 21 in the width direction WD. It is preferable to improve the fit around the legs and other areas by making the elasticity and appearance of the edge area 82 along the opening different from the elasticity and appearance of the other areas. For this purpose, for example, as shown in an enlarged manner in FIG. 22, the shape of the sheet bonding portion 40 in the edge area 82 along the leg opening and the shape of the sheet bonding portion 40 in the other area are different. Can.

As described above, when the sheet bonding portion 40 having a different shape is provided in the area having the elastic sheet stretch structure 20X, the welding failure may occur as described above, or the premature wear or breakage of the device such as the anvil roll. There is a risk of connection. Therefore, all sheet bonding portions 40 in the region having elastic sheet stretch structure 20X have a bonding reference diameter φ of 0.2 mm or more, and the maximum value of bonding reference diameter φ is 1 to 3 times the minimum value, and It is preferable that the circumferential length is 1 to 15 times the circumferential length of the circle having the bonding reference diameter φ as a diameter. The meaning of each numerical value is as described above. That is, if the bonding reference diameter is less than 0.2 mm, welding failure is likely to occur basically. In addition, the overly long or over-folded outer shape sheet joint portion 40 is susceptible to partial welding failure. From this viewpoint, the circumferential length of the sheet bonding portion 40 is preferably in the above range. Furthermore, if the difference in the bonding reference diameter φ of the sheet bonding portion 40 is too large, welding failure is likely to occur if the linear pressure at the time of forming the sheet bonding portion 40 is matched to the large sheet bonding portion 40 of the bonding reference diameter φ. Further, if the linear pressure at the time of forming the sheet bonding portion 40 is increased in accordance with the sheet bonding portion 40 having the small bonding reference diameter φ, there is a possibility of leading to early wear and breakage of equipment such as an anvil roll.

  Here, the bonding reference diameter φ means the diameter of the largest inscribed circle 40 c inscribed in the outer shape of the sheet bonding portion 40. Therefore, as shown in FIGS. 24 (a) and 24 (b), the bonding reference diameter φ of the sheet joining portion 40 having a long and narrow shape is smaller than the major axis, and as shown in FIGS. 24 (c) and 24 (d) The bonding reference diameter φ of the sheet bonding portion 40 having a shape close to a circle such as a pentagon is substantially the same as the major diameter. As shown in FIG. 24E, also in the case of the L-shaped sheet bonding portion 40, the bonding reference diameter φ is smaller than the major diameter. As can be understood from these examples, although not shown, the junction reference diameter φ of the intricately shaped sheet joint portion 40 such as a star-like shape is smaller.

The dimension of the bonding reference diameter φ may be within the above range, but as one preferable example, the first sheet layer and the second sheet layer are non-woven fabrics having a fineness of 0.7 to 6 dtex and a basis weight of 10 to 25 g / m ² In some cases, it is preferable that all the sheet bonding portions 40 in the region having the elastic sheet stretchable structure 20X have a bonding reference diameter φ of 0.2 to 0.8 mm. As a result, it is possible to achieve both suppression of welding defects and prevention of early wear and breakage of the device. The more preferable range of the bonding reference diameter φ is 0.25 to 0.5 mm.

  In the sheet bonding portion 40 having a different shape, the bonding reference diameter φ may be different as in the example shown in FIG. 22 or may be the same as shown in FIG.

  Since the linear pressure that affects welding defects in ultrasonic sealing can be adjusted by force pressure, in order to reliably prevent welding defects, all sheet bonding portions 40 formed by one ultrasonic horn are not as described above. It is desirable to satisfy the condition. Similarly, in the case of heat sealing, it is desirable that all the sheet joining portions 40 formed by the pair of anvil rolls and the opposing rolls satisfy the above conditions.

<Explanation of terms in the specification>
The following terms in the specification have the following meanings unless otherwise indicated in the specification.
"Front body" and "back body" mean front and rear portions of the pants-type disposable diaper, respectively, bordering on the front-rear direction center. In addition, the crotch refers to a range in the front-rear direction including the center in the front-rear direction of the pants-type disposable diaper, and when the absorber has a constricted portion, it refers to the longitudinal range of the portion having the constricted portion.
-"Maximum elongation" means the maximum value of the elongation in the expansion / contraction direction ED (in other words, the expansion in the unfolded state in which the first sheet layer and the second sheet layer unfold flatly without shrinkage or slack) The length is expressed as a percentage when the natural length is 100%.
-"Area ratio" means the ratio of the target portion to the unit area, and the target portion (for example, the sheet bonding portion 40, the opening of the bonding hole 31), the vent hole in the target region The total area of (A) is divided by the area of the target area and expressed as a percentage, and in particular, the "area ratio" in the area having a stretchable structure means the area ratio in a developed state. In the embodiment in which a large number of target portions are provided at intervals, it is desirable to set the target area to a size that includes 10 or more target portions and to obtain the area ratio.
"Stretch rate" means the value when natural length is 100%.
・ "Age" is measured as follows. After the sample or test piece is predried, it is left in a test room or apparatus under standard conditions (test place: temperature 23 ± 1 ° C., relative humidity 50 ± 2%) to be in a constant weight state. Pre-drying refers to bringing a sample or test piece to a constant weight 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 percentage is 0.0%. From a test piece in a constant weight state, using a template for sampling (100 mm × 100 mm), cut out a sample of 100 mm × 100 mm in size. The weight of the sample is measured, multiplied by 100, the weight per square meter is calculated, and taken as the basis weight.
・ The “thickness” of the absorber is the thickness measuring instrument of Ozaki Manufacturing Co., Ltd. (Pecock, Dial Thickness Gauge Large Type, Model J-B (Measurement Range 0 to 35 mm) or Model K-4 (Measurement Range 0 to 50 mm)) Measure with the sample and thickness gauge horizontal.
- other than the above "thickness" is used automatic thickness measuring instrument (KES-G5 Handy Compression measurement program), load: 0.098 N / cm ^2, and the pressure area: automatically measured under the conditions of 2 cm ^2.
・ “Tensile strength” and “Tensile elongation (breaking elongation)” conform to JIS K 7127: 1999 “Plastic-Test method of tensile properties-” except that the test piece is made into a rectangular shape of 35 mm wide × 80 mm long. It means that the initial chuck distance (marked line distance) is 50 mm and the tensile speed is 300 mm / min. For example, AUTOGRAPH AGS-G100N manufactured by SHIMADZU can be used as a tensile tester.
· “Tensile stress” is a tensile test based on JIS K 7127: 1999 “Plastic-Test method for tensile properties-” with an initial chuck spacing (marked line distance) of 50 mm and a tensile speed of 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. Although it is preferable to make a test piece into a rectangular shape with a width of 35 mm and a length of 80 mm or more, when a test piece with a width of 35 mm can not be cut out, a test piece is made with a width that can be cut out and the measured value is 35 mm wide The value converted to In addition, even when the target area is small and sufficient test pieces can not be collected, at least comparison can be made as long as test pieces of the same size are used even if the small test pieces are appropriately compared if the magnitude of the extension stress is compared. . For example, AUTOGRAPH AGS-G100N manufactured by SHIMADZU can be used as a tensile tester.
"Expanded state" means a flat state without contraction or slack.
-Unless otherwise indicated, the dimension of each part means the dimension in the unfolded state, not the natural length state.
・ If there is no description about the environmental conditions in the test or measurement, the test or measurement shall be performed in the test room or equipment under the standard condition (test place: temperature 23 ± 1 ° C, relative humidity 50 ± 2%) Do.

  The present invention is applicable to various types of disposable diapers such as a tape type and a pad type other than the pants type disposable diaper as in the above example, as long as the elastic sheet stretchable structure is applicable. It can be used as a stretchable member in general disposable wear articles such as disposable wear articles for water play.

  DESCRIPTION OF SYMBOLS 10 ... Interior body, 10B ... Internal / external fixed area | region 11 ... Top sheet, 12 ... Liquid-impervious sheet, 13 ... Absorber, 13N ... Bump part, 14 ... Packaging sheet, 17 ... Non-absorber side, 20 ... Exterior body 20A: first sheet layer, 20B: second sheet layer, 20C: folded back portion, 20X: elastic sheet stretchable structure, 21: side seal portion, 23: waist end area, 24: waist elastic member, 25: shrinkage襞, 29: leg line line, 30: elastic sheet, 31: bonding hole, 40: sheet bonding portion, 51, 52: non-bonding zone, 51: first non-bonding zone, 51 d: first direction, 51s: first Spacing, 51 w: first width, 52: second non-bonding zone, 52 d: second direction, 70: non-stretching area, 80: stretching area, 90: solid gather, 93: falling part, 94: free part, 95: ... Gather sheet, 96 ... Ga Elastic elastic members, B: Rear body, ED: Elastic direction, F: Front, L: Intermediate, LD: Longitudinal direction, T: Torso, WD: Width direction, 71: Boundary, φ: Joint reference diameter .

Claims (7)

An elastic sheet is interposed between the first sheet layer made of non-woven fabric and the second sheet layer made of non-woven fabric, and the plurality of sheet junctions where the first and second sheet layers are arranged at intervals. Has an elastic sheet stretchable structure welded through a joint hole penetrating the elastic sheet,
The area having the elastic sheet expansion / contraction structure has an expansion / contraction area which is contracted in the expansion / contraction direction by the contraction of the elastic sheet and is extensible in the expansion / contraction direction,
The first sheet layer and the second sheet layer are non-woven fabrics having a fineness of 0.7 to 6 dtex and a basis weight of 10 to 25 g / m ² ,
The area | region which has the said elastic sheet expansion-contraction structure has a sheet | seat junction part from which a shape differs,
All the sheet bonding portions in the region having the elastic sheet stretch structure have a bonding reference diameter of 0.2 to 0.5 mm, and a circumferential length of a circle whose diameter corresponds to the bonding reference diameter. 1 to 15 times of,
Expandable member characterized in that. The area ratio of the sheet bonding portion is 1.8 to 19.1% .
The expandable member according to claim 1. An elastic sheet is interposed between the first sheet layer made of non-woven fabric and the second sheet layer made of non-woven fabric, and the plurality of sheet junctions where the first and second sheet layers are arranged at intervals. Has an elastic sheet stretchable structure welded through a joint hole penetrating the elastic sheet,
The area having the elastic sheet expansion / contraction structure has an expansion / contraction area which is contracted in the expansion / contraction direction by the contraction of the elastic sheet and is extensible in the expansion / contraction direction,
The area | region which has the said elastic sheet expansion-contraction structure has a sheet | seat junction part from which a shape differs,
The bonding reference diameter is 0.2 mm or more, the maximum value of the bonding reference diameter is 1 to 3 times the minimum value, and the circumferential length of all the sheet bonding portions in the region having the elastic sheet stretch structure are bonding 1 to 15 times the circumferential length of the circle whose diameter is the standard diameter,
The area having the elastic sheet expansion and contraction structure includes the expansion and contraction area and a non-expansion and contraction area provided on at least one side in the expansion and contraction direction of the expansion and contraction area.
The area ratio of the sheet bonding portion in the stretchable region is 0.5 to 1 times the area ratio of the sheet bonding portion in the non-stretchable region,
The entire boundary between the stretchable region and the non-stretchable region , which extends in the direction intersecting with the stretchable direction, has a shape in which it is continuously shifted only to one side in the stretchable direction from the one end to the other end Have,
Expandable member characterized in that . An integral exterior body extending from the front to the back, or an exterior provided separately for the front and the back, and an interior extending to the front and back of the crotch attached to the widthwise middle of the exterior. A disposable pants-type wearable article comprising a side seal portion in which both sides of an exterior body in a front body and both sides of an exterior body in a back body are joined, and a waist opening and a pair of left and right legs. ,
The exterior body of the front body and the back body has a waist portion which is a range in the front-rear direction corresponding to the side seal portion,
The exterior body in at least one of the front body and the back body has an intermediate portion positioned on the center side in the front-rear direction with respect to the waist portion,
The middle portion has an edge area along the leg opening,
Exterior body having a middle portion over the waist portion from within said intermediate portion in the longitudinal direction and over a period the side seal portion in the width direction, the elastic sheet stretching structure of claim 1, wherein, stretching direction of the stretchable region Is an expansion and contraction member provided in the width direction,
The shape of the seat joint portions in the edge region along the leg openings, is that different to the shape of the sheet bonding portion of the other region,
Disposable wear article characterized in that. An integral exterior body extending from the front to the back, or an exterior provided separately for the front and the back, and an interior extending to the front and back of the crotch attached to the widthwise middle of the exterior. A disposable pants-type wearable article comprising a side seal portion in which both sides of an exterior body in a front body and both sides of an exterior body in a back body are joined, and a waist opening and a pair of left and right legs. ,
The exterior body of the front body and the back body has a waist portion which is a range in the front-rear direction corresponding to the side seal portion,
The exterior body in at least one of the front body and the back body has an intermediate portion positioned on the center side in the front-rear direction with respect to the waist portion,
The middle portion has an edge area along the leg opening,
The elastic sheet stretchable structure according to claim 3, wherein the exterior body having the middle portion extends from the middle portion to the inside of the waist portion in the front-rear direction and between the side seal portions in the width direction. Is an expansion and contraction member provided in the width direction,
Exterior body having the elastic sheet stretchable structure, which has the non-stretchable region in the width direction intermediate portion, the width-direction range corresponding to between the side seal portion and the non-stretchable region is said stretchable region ,
The area ratio of the sheet bonding portion in the stretchable region is 0.5 to 1 times the area ratio of the sheet bonding portion in the non-stretchable region,
The entire boundary between the stretchable region and the non-stretchable region , which extends in the direction intersecting the stretch direction , continuously extends from the end on the waist opening side toward the center in the front-rear direction of the disposable wearing article It has a shape that only shifts to
Disposable wear article characterized in that . Supplying the elastic sheet in a state of being stretched in the MD direction between the first sheet layer and the second sheet layer;
An anvil roll having a large number of projections arranged in a predetermined pattern on the outer peripheral surface of the first sheet layer, the second sheet layer, and the elastic sheet in an extended state interposed therebetween; The first sheet layer and the second sheet layer are welded between the ultrasonic horns facing the outer peripheral surface of the anvil roll, and only the portion sandwiched between the multiple projections and the ultrasonic horns is welded to join the sheets. Forming a portion, bonding step,
Including
The first sheet layer and the second sheet layer are non-woven fabrics having a fineness of 0.7 to 6 dtex and a basis weight of 10 to 25 g / m ² ,
While forming sheet junctions with different joining reference diameters with one ultrasonic horn,
All of the sheet joints formed by one ultrasonic horn have a joint reference diameter of 0.2 to 0.5 mm and a circumferential length of a circle whose diameter corresponds to the joint reference diameter. 1 to 15 times,
A manufacturing method of an elastic member characterized by things. Supplying the elastic sheet in a state of being stretched in the MD direction between the first sheet layer and the second sheet layer;
An anvil roll having a large number of projections arranged in a predetermined pattern on the outer peripheral surface of the first sheet layer, the second sheet layer, and the elastic sheet in an extended state interposed therebetween; The first sheet layer and the second sheet layer are sandwiched between the plurality of projections and the opposing roll by passing between the outer circumferential surface of the anvil roll and the opposing roll opposed to each other by the heated anvil roll and the opposing roll. Bonding step to form a sheet bonding portion by welding only
Including
The first sheet layer and the second sheet layer are non-woven fabrics having a fineness of 0.7 to 6 dtex and a basis weight of 10 to 25 g / m ² ,
While forming a sheet joining portion having different joining reference diameters by the pair of anvil rolls and the opposing rolls,
All the above-mentioned sheet junctions formed by a pair of anvil rolls and opposing rolls have a joining reference diameter of 0.2 to 0.5 mm, and a circumferential length of a circle whose diameter corresponds to the joining reference diameter. 1 to 15 times the
A manufacturing method of an elastic member characterized by things.

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