JP7161438B2 - Stretchable member and underpants-type disposable wearing article having this stretchable member - Google Patents

Description

TECHNICAL FIELD The present invention relates to a stretchable member having a stretchable structure in which an elastic sheet such as an elastic sheet is sandwiched between a first sheet layer and a second sheet layer, and a pants-type disposable wearing article having this stretchable member.

Disposable wearing articles such as disposable diapers are generally provided with stretchability around the legs and around the waist in order to improve the fit to the body surface. Conventionally, as a method for imparting elasticity, a method of attaching an elongated elastic member such as rubber thread while being stretched in its longitudinal direction has been widely adopted. employs a mode in which the rubber threads are fixed in a state of being arranged side by side at intervals in the width. In addition, as a method for providing an even better fit as a surface, a method of attaching an elastic sheet in a state of being stretched in the direction of imparting elasticity has also been proposed, including those of the present applicant. (See Patent Documents 1 and 2, for example).

This stretchable structure using an elastic film (hereinafter also referred to as an elastic sheet stretchable structure) is formed by laminating an elastic film between a first sheet layer whose stretchable region is made of nonwoven fabric and a second sheet layer made of nonwoven fabric. , in a state in which the elastic film is stretched in the stretching direction along the surfaces thereof, the first sheet layer and the second sheet layer are arranged in the stretching direction and in the direction perpendicular thereto, respectively, in the shape of a number of dots arranged at intervals. The sheet is joined through a joint hole penetrating the elastic film.
In such an elastic sheet stretchable structure, since the elastic film shrinks between the sheet joints in the natural length state, the gap between the sheet joints becomes narrower, and the sheet joints of the first sheet layer and the second sheet layer Contraction wrinkles extending in a direction intersecting with the stretching direction are formed.
On the other hand, during elongation, as the elastic film stretches between the sheet joints, the gap between the sheet joints and the contraction wrinkles in the first sheet layer and the second sheet layer widen, and the first sheet layer and the second sheet layer expand. It is possible to elastically extend to the fully deployed state. This elastic sheet stretchable structure is not only excellent in surface fitting properties, but also has no surface bonding between the first sheet layer and the second sheet layer and the elastic film. Since the number of bonding points is extremely small, it is very flexible, and there is an advantage that the bonding holes in the elastic film also contribute to the improvement of air permeability in the thickness direction.

However, when the shrinkage wrinkles continue for a long time, the appearance of the product is observed to be uniform with the shrinkage wrinkles repeated in a wavy shape in one direction, and the appearance becomes monotonous, and the appeal of the product to consumers is poor.

Japanese Patent No. 5967736 JP 2015-204982 A

Therefore, the main object of the present invention is to provide an absorbent article that exhibits a complex appearance rather than a monotonous shrink wrinkle, and that is highly appealing to consumers when applied to absorbent articles.

The elastic member of the present invention, which solves the above problems,
An elastic sheet is interposed between a first air-permeable sheet layer and a second air-permeable sheet layer, and the first sheet layer and the second sheet layer are arranged with a gap therebetween. and an elastic sheet elastic structure joined through a joint hole penetrating the elastic sheet or through the elastic sheet,
The stretchable region indicating the stretchable structure of the elastic sheet is stretchable in the stretchable direction due to the stretching force of the elastic sheet,
wherein the joints form rows of joints spaced along an alignment direction that intersects the stretch direction;
A large number of the joint rows are formed at intervals in the stretching direction,
A third joint row is formed between the adjacent first joint row and second joint row,
The joints forming the first joint row, the joints forming the second joint row, and the joints forming the third joint row are all oriented in the same direction along the alignment direction. and
the spacing of at least a part of the third joint row in the alignment direction is longer than the spacing in the alignment direction of the first joint row and the second joint row on both sides of the third joint row;
The angle at which the alignment direction intersects the stretch direction is within a range of 45 degrees to 135 degrees, and the alignment direction is inclined with respect to the stretch direction.
It is characterized by

When at least a part of the spacing in the alignment direction of the third joint row is longer than the spacing in the alignment direction of the first joint row and the second joint row on both sides of the third joint row, the first joint Shrink wrinkles can be formed between the row and the second row of joints with a limited joint-to-joint length of the third row of joints.
If the third joint does not exist, the shrinkage wrinkles generated over the entirety between the first joint row and the second joint row are long pleated ones (hereinafter “inter-row continuous pleats”). The inter-row continuous pleats undulate in the stretching direction, giving a monotonous appearance.
In contrast, the contraction wrinkles generated according to the present invention are contraction wrinkles with a limited length across the joints of the third joint row and are not continuous in the entire alignment direction. Since the shrinkage wrinkles appear dispersedly in the stretching direction and alignment direction, the appearance is excellent.
In other words, the shrink wrinkles present a complex appearance rather than a monotonous one, and when applied to absorbent articles, they are highly appealing to consumers.

An angle between the aligning direction and the stretching direction may be 45 degrees to 135 degrees.
By providing the crossing angle, when applied to an absorbent article, the shrinkage wrinkles are not aligned in the front-rear direction, but the shrinkage wrinkles can be made to appear in an oblique direction. By arranging it in the width direction, it is possible to present a peculiar appearance different from the form in which contraction wrinkles appear in the front-rear direction, and it is highly appealing to consumers.

In the embodiment, the joints of the third joint row form intersecting rows aligned in a direction transverse to the joint row groups together with the adjacent joints of the first joint row and the joints of the second joint row. I can provide the form.

In addition, contraction wrinkles are formed in the alignment direction on both sides of the joint row. Conversely, between the shrink wrinkles in the alignment direction and the shrink wrinkles in the alignment direction are rows of joints. If the rows of joints between the shrinkage creases are continuous throughout the alignment direction, the airflow path will be generally straight.
However, when the wearer wears the absorbent article, the contact of the wearer's skin with the elastic region (for example, whether it contacts strongly or weakly) may differ, and in this case, the ventilation path is partially insufficient. Sometimes.
On the other hand, when the third joint row is formed, a ventilation path is formed along the third joint row, the ventilation path in the alignment direction and the ventilation path in the direction crossing the joint row group are communicated, and the mesh is formed. As a result of the formation of the mesh-shaped ventilation paths, the stuffiness emitted from the wearer can be exhausted through the mesh-shaped ventilation paths.

The cross rows may be formed in a plurality of rows spaced apart in the alignment direction.
The discontinuity between shrinkage wrinkles in the alignment direction and shrinkage wrinkles becomes clear in appearance, and the design becomes clear.
Moreover, there is also an advantage that the ventilation path can be sufficiently secured.

The pants-type disposable wearing article having the elastic member is
An integrated outer body extending from the front body to the back body, or an outer body provided separately on the front body and the back body, and an inner body attached to the middle part in the width direction of the outer body and extending over both front and rear sides of the crotch part. , a side seal portion in which both side portions of the exterior body of the front body and both side portions of the exterior body of the back body are respectively joined, and a waist opening and a pair of left and right leg openings. A pants-type disposable wearing article having the elastic member according to item 1,
The outer body of at least one of the front body and the back body has the elastic sheet over a width direction range corresponding to between the side seal portions in at least a partial range in the front-rear direction. is provided as
It is characterized by

When the elastic member is applied as an outer covering in a pants-type disposable wearing article, the product fully exhibits the advantages in terms of appearance obtained according to the present invention.

As described above, according to the present invention, shrinkage wrinkles are not monotonous but have a complex appearance, and when this is applied to absorbent articles, they are highly appealing to consumers.

Fig. 2 is a plan view (inner surface side) of the underpants-type disposable diaper in an unfolded state; 1 is a plan view (outer surface side) of a pants-type disposable diaper in an unfolded state; FIG. FIG. 2 is a plan view showing only the essential parts of the underpants-type disposable diaper in an unfolded state; (a) is a cross-sectional view taken along line CC of FIG. 1, and (b) is a cross-sectional view taken along line EE of FIG. FIG. 2 is a cross-sectional view taken along the line AA of FIG. 1; FIG. 2 is a cross-sectional view taken along the line BB of FIG. 1; Fig. 10 is a plan view (inner surface side) of a stretchable region of the pants-type disposable diaper in an unfolded state; (a) is a cross-sectional view corresponding to line CC of FIG. 1, and (b) is a cross-sectional view corresponding to line EE of FIG. FIG. 2 is a plan view and a cross-sectional view showing a joint arrangement disclosed in Patent Document 1; FIG. 4 is a plan view showing a joint arrangement disclosed in Patent Document 2; FIG. 4 is a plan view showing a joint arrangement as a reference example for explanation; 1 shows a first embodiment of the joint arrangement of the present invention; FIG. 4 is a plan view showing a second embodiment of the joint arrangement of the present invention; FIG. 11 is a plan view showing a third embodiment of the joint arrangement of the present invention; FIG. 11 is a plan view showing a fourth embodiment of the joint arrangement of the present invention; FIG. 11 is a plan view showing a fifth embodiment of the joint arrangement of the present invention; FIG. 11 is a plan view showing a sixth embodiment of the joint arrangement of the present invention; FIG. 11 is a plan view showing a seventh embodiment of the joint arrangement of the present invention; FIG. 12 is a plan view showing an eighth embodiment of the joint arrangement of the present invention; FIG. 12 is a plan view showing a ninth embodiment of the joint arrangement of the present invention; FIG. 10 is a plan view showing a tenth embodiment of the joint arrangement of the present invention; FIG. 11 is a plan view showing an eleventh embodiment of the joint arrangement of the present invention; FIG. 20 is a plan view showing a twelfth embodiment of the joint arrangement of the present invention; FIG. 20 is a plan view showing a thirteenth embodiment of the joint arrangement of the present invention; FIG. 20 is a plan view showing a fourteenth embodiment of the joint arrangement of the present invention; FIG. 4 is a plan view showing an example of a joint form at a joint; FIG. 4 is an explanatory cross-sectional view showing an example of a bonding form; FIG. 4 is an explanatory cross-sectional view showing an example of a bonding form; FIG. 10 is a plan view showing an example of a bonding form; 1 is a schematic diagram of an ultrasonic sealing device for manufacturing an elastic member; FIG.

An embodiment of the present invention will be described in detail below with reference to the accompanying drawings. Note that the dotted pattern portion in the cross-sectional view indicates a bonding means such as a hot-melt adhesive.
1 to 6 show a pants-type disposable diaper as an example of the disposable wearing article of the present invention. LD (longitudinal direction) indicates the front-rear direction, and WD indicates the width direction.
This pants-type disposable diaper (hereinafter also simply referred to as a diaper) has an outer body 20 forming a front body F and a back body B, and an inner body 10 fixed and integrated to the inner surface of the outer body 20. The inner body 10 has an absorbent body 13 interposed between a liquid-permeable top sheet 11 and a liquid-impermeable sheet 12 . In manufacturing, after the back surface of the inner body 10 is joined to the inner surface (upper surface) of the outer body 20 by a joining means such as a hot-melt adhesive, the inner body 10 and the outer body 20 are joined to the front body F and the back body B. By folding at the center of the front-back direction LD (longitudinal direction), which is the boundary of the waist opening and the left and right It becomes a pants-type disposable diaper in which a pair of leg openings are formed.

(Example of internal body structure)
As shown in FIGS. 4 to 6, the inner body 10 has a structure in which an absorbent body 13 is interposed between a liquid-permeable top sheet 11 and a liquid-impermeable sheet 12 made of polyethylene or the like. The top sheet 11 absorbs and retains the excreted fluid that has permeated through the top sheet 11 . Although the planar shape of the interior body 10 is not particularly limited, it is generally rectangular as shown in FIG.

As the liquid-permeable top sheet 11 covering the front side (skin side) of the absorbent body 13, a perforated or non-perforated nonwoven fabric, a porous plastic sheet, or the like is preferably used. The material fibers that make up the non-woven fabric can be synthetic fibers such as olefins such as polyethylene or polypropylene, polyesters, and polyamides, as well as recycled fibers such as rayon and cupra, and natural fibers such as cotton. , spunbond method, thermal bond method, meltblown method, needle punch method, etc. can be used. Among these processing methods, the spunlace method is superior in flexibility and drapeability, and the thermal bond method is superior in that it is bulky and soft. When a large number of through-holes are formed in the liquid-permeable top sheet 11, urine and the like are quickly absorbed, and the dry touch is excellent. The liquid-permeable top sheet 11 extends to the back side of the absorbent body 13 by wrapping around the side edges of the absorbent body 13 .

The liquid-impermeable sheet 12 covering the back side (non-skin-contacting side) of the absorbent body 13 is made of a liquid-impermeable plastic sheet such as polyethylene or polypropylene. is preferably used. This water-impermeable/moisture-permeable sheet is a microporous sheet obtained by, for example, forming a sheet by melt-kneading an inorganic filler in an olefin resin such as polyethylene or polypropylene, and then stretching the sheet in a uniaxial or biaxial direction. be.

The absorber 13 is a known one, for example, a pile of pulp fibers, an aggregate of filaments such as cellulose acetate, or a non-woven fabric, which is optionally mixed or fixed with a superabsorbent polymer. can be used. The absorber 13 can be wrapped with a liquid-permeable and liquid-retaining wrapping sheet 14 such as crepe paper, if necessary, for shape and polymer retention.

The absorber 13 has a substantially hourglass shape with a constricted portion 13N narrower than the front and rear sides in the crotch portion. The size of the constricted portion 13N can be appropriately determined, but the length in the front-rear direction of the constricted portion 13N can be about 20 to 50% of the total length of the diaper, and the width of its narrowest portion is 40% of the total width of the absorbent body 13. It can be about 60%. In the case where the inner body 10 has such a constricted portion 13N, if the planar shape of the inner body 10 is substantially rectangular, a portion of the inner body 10 corresponding to the constricted portion 13N of the absorbent body 13 does not have the absorbent body 13. Absorber side portions 17 are formed.

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

Three-dimensional gathers 90 that fit around the legs are formed on both sides of the inner body 10 . As shown in FIGS. 5 and 6, the three-dimensional gathers 90 include a fixing portion 91 fixed to the side portion of the back surface of the inner body 10, and the inner body 10 extending from the fixing portion 91 to the side of the inner body 10. and the front and rear ends of the body portion 92 are fixed to the side portions of the surface of the interior body 10 (the top sheet 11 in the illustrated form) in a fallen state. It has a portion 93 and a free portion 94 between which the lying portion 93 is not fixed. Each of these parts is formed by a gather sheet 95 formed by folding a sheet of nonwoven fabric or the like into a double sheet. The gathered sheet 95 is attached over the entire front-to-rear direction of the inner body 10 , the fallen portions 93 are provided on the front and rear sides of the non-absorbent side portion 17 , and the free portions 94 are on both front and rear sides of the non-absorbent side portion 17 . extended. Also, between the double gather sheets 95, an elongated gather elastic member 96 is disposed at the tip of the free portion or the like. The gather elastic member 96 is for raising the free portion 94 by elastic stretching force as shown in FIG. 5 in the product state.

In the form shown in FIGS. 5 and 6, the gather elastic member 96 is adhesively fixed to the gather sheet 95 via a hot-melt adhesive at the position of the gather elastic member 96 except for the non-stretchable portion 97, and the gather sheet 95 However, in the lodging non-stretchable portion 97, there is no hot-melt adhesive at the position of the gathering elastic member 96, so the gathering elastic member 96 and the gathering sheet 95 are not bonded, and the gathering elastic The facing surface of the gather sheet 95 is not joined at the position where the member 96 is provided.

The three-dimensional gathers 90 shown in FIGS. 5 and 6 have a form in which the main body portion 92 is not folded.

Materials such as styrene rubber, olefin rubber, urethane rubber, ester rubber, polyurethane, polyethylene, polystyrene, styrene butadiene, silicone, and polyester can be used for the gather elastic member 96 . Also, in order to make it difficult to see from the outside, it is preferable to set the thickness to 925 dtex or less, the tension to 150 to 350%, and the interval to 7.0 mm or less. As the gather elastic member 96, a tape-like member having a certain width can be used in addition to the filament-like one shown in the figure.

As with the liquid-permeable top sheet 11, the raw material fibers constituting the gather sheet 95 are synthetic fibers such as olefins such as polyethylene or polypropylene, polyesters, and polyamides, recycled fibers such as rayon and cupra, and cotton. and other natural fibers, and nonwoven fabrics obtained by appropriate processing methods such as spunbonding, thermal bonding, meltblowing, and needle punching can be used. It is preferable to use a nonwoven fabric having a low basis weight and excellent air permeability. Furthermore, the gather sheet 95 is coated with a silicone, paraffin metal, or alkylchromic chloride water repellent agent to prevent permeation of urine and the like, prevent rashes, and improve the touch (dry feeling) to the skin. It is desirable to use a water-repellent nonwoven fabric coated with

As shown in FIGS. 3 to 6, the rear surface of the inner body 10 is joined to the inner surface of the outer body 20 at the inside/outside fixed area 10B (hatched area) with a hot-melt adhesive or the like. The inside/outside fixing region 10B can be determined as appropriate, and can be substantially the entire width direction WD of the inner body 10, but it is preferable that both ends in the width direction are not fixed to the exterior body 20. FIG.

(Structure example of exterior body)
The exterior body 20 extends outward from the side edge of the absorbent body 13 . In the crotch portion of the outer body 20, the side edge of the outer body 20 may be positioned more centrally in the width direction than the side edge of the inner body 10, as in the illustrated embodiment, or may be positioned on the outer side in the width direction. In addition, the outer body 20 is the front-rear direction range between the waist portion T corresponding to the side seal portion 21 and the waist portion T of the front body F and the waist portion T of the back body B. a middle portion L;

In the illustrated embodiment of the exterior body 20, except for the middle portion in the front-rear direction of the middle portion L, as shown in FIGS. , an elastic sheet, for example, an elastic film 30 is interposed, and as shown in FIG. It has an elastic sheet elastic structure 20X joined through a joint hole 31 penetrating the film 30 .
In the form of application to the diaper, the elastic sheet (elastic film 30 in the example of FIG. 9) stretches and contracts ED in the width direction WD of the diaper.

The first sheet layer 20</b>A and the second sheet layer 20</b>B may be indirectly joined via the elastic film 30 instead of through the joining holes 31 of the elastic film 30 . The planar shape of the exterior body 20 is formed by concave leg circumference lines 29 so that the width direction side edges of the intermediate portion L form leg openings, respectively, and the overall shape resembles an hourglass. The outer body 20 may be formed separately from the front body F and the back body B, and the two may be arranged so as to be separated from each other in the front-rear direction LD of the diaper at the crotch portion.

The configuration shown in FIGS. 1 and 2 is a configuration in which the elastic sheet elastic structure 20X extends to the waist edge 23. However, if the elastic sheet elastic structure 20X is used for the waist edge 23, the waist edge 23 can be stretched. If necessary, such as insufficient tightening, the elastic sheet stretchable structure 20X is not provided at the waist end 23 as shown in FIGS. Structures can also be provided. The waist elastic member 24 is an elongated elastic member such as a plurality of thread rubbers arranged at intervals in the front-rear direction LD, and provides elastic force so as to tighten the circumference of the body. The waist elastic members 24 are not arranged substantially as a bundle with 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 elastic zone. , preferably five or more. Although the elongation rate of the waist elastic member 24 when fixed can be determined as appropriate, it can be about 230 to 320% in the case of normal adult use. In the illustrated example, the waist elastic member 24 uses thread rubber, but other elongated stretchable members such as flat rubber may be used. Although not shown, an elastic film 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 film 30 to form a stretchable structure with both elastic members. In the illustrated embodiment, the edge portion of the leg opening in the exterior body 20 is not provided with an elongated elastic member extending along the leg opening. An elongated elastic member may be provided instead of the elastic film 30 at the part.

As another form (not shown), an intermediate part L between the waist part T of the front body F and the waist part T of the back body B is not provided with the elastic sheet elastic structure 20X. 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 to the inside of the waist portion T of the back body B through the intermediate portion L, or either the front body F or the back body B. Appropriate modification such as provision of the elastic sheet expansion structure 20X only in the upper part is also possible.

(Form of junction)
The present invention is characterized by the arrangement of the joints. In order to clarify this feature, the arrangement of the joints in the conventional example will be specifically described.

FIG. 9 is shown in Patent Document 1 as a representative example.
That is, the joints 40 are arranged in a zigzag arrangement, the joints 40 are elongated in a direction perpendicular to the stretching direction, and are symmetrical with respect to a center line passing through the center of the stretching direction (left-right symmetry in FIG. 9A). The width 40x of the joints 40 in the expansion/contraction direction is preferably 0.2 to 0.4 mm, and the interval d1 between the joints 40 arranged in the expansion/contraction direction is 3 to 12.9 mm, more preferably 5 to 5 mm. The distance d2 between the joints 40 arranged in the direction orthogonal to the expansion/contraction direction is set to 6.4 mm, and the distance d2 is set to 2 to 10.5 mm, more preferably 2.3 to 4.6 mm.
In this way, the joints 40 with a remarkably narrow width 40x in the stretching direction are arranged in a zigzag pattern with a relatively wide spacing d1 in the stretching direction, and the contractive force of the elastic film 30 is applied directly to each joint 40. As a result, the arrangement and spacing of the joints 40 at the positions of the joint holes 31 of the elastic film 30 are firmly maintained, and as a result, the flexibility is less likely to decrease. In addition, the folds 25f extend almost straight along the direction perpendicular to the stretching direction, and the joints 40 are hidden between the folds 25f and become inconspicuous. As a result, the elastic sheet stretchable structure 20X has an appearance closer to cloth while suppressing a decrease in flexibility.

On the other hand, although the joints 40 are arranged in a staggered arrangement, if the joints 40 are circular, the joints 40 can be clearly seen between the folds 25f of the wrinkles and the folds 25f. Since the pleats 25f extend in a direction orthogonal to the stretching direction so as to largely wrap around the joints 40, the pleats 25f are formed in a wavy line shape as a whole, and there is a tendency that a fabric-like appearance cannot be obtained.

From this point of view, it is desirable that the shape of the joint portion 40 is elongated in the direction perpendicular to the expansion/contraction direction. However, if the maximum length of the joining portion 40 in the direction orthogonal to the stretching direction is too short or too long, the straightness of the pleats 25f may deteriorate and the flexibility may deteriorate. Therefore, although these dimensions can be determined as appropriate, the length 40y of the joint 40 in the direction orthogonal to the expansion/contraction direction is preferably 0.4 to 3.2 mm, particularly 0.7 to 1.4 mm. It is

On the other hand, in Patent Document 2, both the two examples shown in FIGS. ) in which small circular sub-joints are arranged between rectangular main openings. The example (b) is also based on the concept of staggered arrangement.
The arrangement and dimensions of each opening are preferably within the dimension range (unit: mm) shown in FIG.

Both inventions of Patent Documents 1 and 2 disclose vertically elongated openings and also disclose a staggered arrangement.
However, in the conventional example, since the gap between the openings of the elastic film in the direction orthogonal to the stretching direction is set large, the stretching stress in the stretching direction is high, and when applied to, for example, a pants-type disposable diaper, the elastic film is excessively stretched. There are not a few wearers who feel that they will be strongly tightened (in the width direction).
Here, the opening length B is set to 0.3 to 0.7 mm, and the interval H is set to 0.6 to 1.4 mm.

On the other hand, as shown in FIG. 11, the present inventor found that if the spacing between the openings of the elastic film in the direction perpendicular to the stretching direction (the vertical direction in the drawing: the direction of symbol LD) is set small, the stretching The present inventors have found that the stretch stress in the direction can be reduced, so that when applied to an underpants-type disposable diaper, it is possible to gently fit the wearer with a weak tightening force.
The reason for this is that the openings open in the width direction to form joining holes 31 as shown in FIG. Even if it is stretched in the width direction, there are no openings in the spaced-apart regions perpendicular to the stretching direction between the sections. It is believed that there is.

In the form shown in FIG. 11, in addition to being able to fit the wearer gently, the area ratio occupied by the joints and the area ratio occupied by the joint holes in the state of use extended in the width direction are high, so it is excellent in breathability. It also brings the advantage of
However, in the usage pattern of the product shown in FIG. 11(a),
in the alignment direction (perpendicular direction) in the spaced-apart region between the row of joints 40, 40 ... along the orthogonal direction LD and the adjacent row of joints 40, 40 ... separated in the stretching direction ED (width direction) Wrinkles are formed along the LD. As shown in FIG. 11(b), this wrinkle 25F is simply a uniform mountain shape. That is, it differs from the cross section shown in US Pat.
When the form shown in FIG. 11 is viewed from the viewpoint of design as the entire stretchable region of the product, wrinkles 25F (inter-row continuous pleats) long in the alignment direction LD are formed in a uniform repetition in the stretch direction ED (width direction). It is likely to be a simple design that only exists, and the product lacks appeal.

The present invention has a first joint portion and a second joint portion, and specifically has the configuration described in the claims, includes various forms, and also includes combinations of various forms.
Due to space limitations, representative examples will be sequentially described below.
12 to 25 illustrate the arrangement of the joint 40 between the first sheet layer 20A and the second sheet layer 20B, and the shrinkage wrinkles generated by the shrinkage of the elastic sheet, for example, the elastic film 30 are indicated by 26. Indicated. Although the shape of the joint portion 40 can be selected as appropriate, a rectangular shape is exemplified.
Also, the ventilation path is indicated by PW (broken line path).

<First embodiment>
In the elastic member according to the first embodiment shown in FIG. 12, an elastic sheet ( (not shown) is interposed, and the first sheet layer and the second sheet layer are joined at a number of spaced sheet joints 40 through joint holes (not shown) penetrating the elastic sheet. Alternatively, it has an elastic sheet stretchable structure joined via the elastic sheet.
Further, the stretchable region indicating the stretchable structure of the elastic sheet can be stretched in the stretching direction by the stretching force of the elastic sheet.

In the present invention, the joints 40 are formed in spaced rows of joints (FIG. 12) along an alignment direction that intersects the stretch direction (perpendicularly in the example shown in FIG. 12). In the illustrated example, they are aligned vertically.)

In FIG. 12, a third joint row A3 is formed between the adjacent first joint row A1 and second joint row A2, and at least a part of the third joint row A3 is spaced S3 in the alignment direction. is longer than the intervals S1 and S2 in the alignment direction between the first joint row A1 and the second joint row A2 on both sides of the third joint row A3.

In such a form, contraction wrinkles 26 having a limited length between the joints 40 of the third joint row A3 are formed between the first joint row A1 and the second joint row A2. can be formed.
If the third joints 40 were not present, the contraction wrinkles generated over the entirety between the first joint row A1 and the second joint row A2 would result in long pleats as shown in FIG. The inter-row continuous pleats are wavy in the stretching direction, and the appearance is monotonous.
In contrast, the shrinkage wrinkles 26 produced in accordance with the present invention extend between the first joint row A1 and the second joint row A2 and between the joints 40 and 40 of the third joint row A3. Since the shrinkage wrinkles 26 have a limited length and are not continuous in the entire alignment direction, the shrinkage wrinkles 26 appear dispersedly in the stretching direction and the alignment direction, resulting in an excellent appearance.
In other words, the shrink wrinkles 26 have a complex appearance rather than a monotonous one, and when applied to absorbent articles, they are highly appealing to consumers.

Note that the alignment direction is not perpendicular to the expansion/contraction direction ED (WD) as in the example of FIG. 25, which will be described later, but the intersection angle θ can be within a range of 45 degrees to 135 degrees, for example.
By providing the crossing angle, when applied to an absorbent article, the contracted wrinkles 26 can be made to appear in an oblique direction instead of aligning the contracted wrinkles in the front-back direction. By arranging it in the width direction of the article, it is possible to present a peculiar appearance, which is different from the conventional form in which contraction wrinkles appear in the front-rear direction, and it is highly appealing to consumers.

On the other hand, as shown in FIG. 12, the joints 40 of the third joint row are aligned with the adjacent joints 40 of the first joint row A1 and the joints 40 of the second joint row. Embodiments can be provided that form cross rows X aligned across the group.

Alignment direction shrink wrinkles 26 are formed on both sides of the joint row. Conversely, there is a joint row between the shrink wrinkles 26 in the alignment direction and the shrink wrinkles 26 in the alignment direction. If the rows of junctures between shrinkage wrinkles 26, 26 are continuous throughout the alignment direction, the airflow path will be generally straight.
However, when the wearer wears the absorbent article, the contact of the wearer's skin with the elastic region (for example, whether it contacts strongly or weakly) may differ, and in this case, the ventilation path is partially insufficient. Sometimes.
On the other hand, when the third joint row A3 is formed, the ventilation path PW is formed along the joints 40 of the third joint row A3, and the ventilation path PW in the alignment direction and in the direction crossing the joint row group is formed. The ventilation paths PW are communicated with each other to form a mesh-like ventilation path PW. As a result, the stuffiness emitted from the wearer can be exhausted through the mesh-like ventilation path PW.

<Second embodiment>
In the embodiment shown in FIG. 13, the joint portions 40 of the first joint portion A1 row and the joint portions 40 of the second joint portion row A1 are different in shape and size, and the intervals S1 and S2 are different.

<Third embodiment>
In the embodiment shown in FIG. 14, the joints 40 of the third joint row cross joint rows together with the joints 40 of the adjacent first joint row A1 and the joints 40 of the second joint row. In this form, crossing rows X aligned in the direction are formed. In particular, two rows of cross rows X are formed. The width of the ventilation path PW (the width in the vertical direction in the illustrated example) is larger than that of the first embodiment, and the ventilation is improved.

<Fourth embodiment>
The embodiment shown in FIG. 15 is an example in which the shrinkage wrinkles 26 are formed in a stepped manner. The design can be complicated rather than monotonous, and can give a sense of luxury. Further, the ventilation path PW is formed stepwise.

<Fifth embodiment>
The embodiment shown in FIG. 16 is an example in which the shrinkage wrinkles 26 are formed in a wave shape as a whole. As a design, it can give a sense of dynamism instead of being monotonous. Also, the ventilation path PW is formed in a wavy shape.

<Sixth embodiment>
The embodiment shown in FIG. 17 is an example in which the contraction wrinkles 26 are formed as hexagons with slightly rounded corners. The design is not monotonous and can give interest. Also, the ventilation path PW is formed in a honeycomb.

<Seventh embodiment>
The embodiment shown in FIG. 18 is an example in which the contraction wrinkles 26 are formed in a more complicated shape elongated vertically. The design is not monotonous and can give interest. Also, the ventilation path PW is formed in an angular wave shape.

<Eighth embodiment>
The embodiment shown in FIG. 19 is an example in which the cross rows are slanted. Shrink wrinkles 26 are such that oblique rectangles are generated. The design is not monotonous and can give interest.

<Ninth embodiment>
In the embodiment shown in FIG. 20, in contrast to the example in FIG. 18, the existence of the joints 40, 40 of the first joint row A1 causes an annular contraction wrinkle 26 to be generated. . The design is not monotonous and can give interest. Also, the ventilation path PW is formed in an angular wave shape.

<Tenth embodiment>
The embodiment shown in FIG. 21 is an example in which the cross rows are slanted in the opposite direction to the example in FIG. Shrink wrinkles 26 are such that oblique rectangles are generated. The design is not monotonous and can give interest.

<Eleventh embodiment>
The embodiment shown in FIG. 22 is an example in which the crossing rows are inclined in a plurality of rows, in the illustrated example, in three rows. Shrink wrinkles 26 are such that oblique rectangles are generated. The design is not monotonous and can give interest.

<Twelfth embodiment>
In the embodiment shown in FIG. 23, shrink wrinkles 26 of different sizes are generated. The design is not monotonous and can give interest.

<Thirteenth embodiment>
In the embodiment shown in FIG. 24, three shrink wrinkles 26 with different sizes are generated. The design is not monotonous and can give interest.

<14th embodiment>
In the above example, the alignment direction is perpendicular to the expansion/contraction direction ED (WD). They can be crossed in the range of ~135 degrees. The design is not monotonous and can give interest. The crossing angle θ is preferably 50 degrees to 130 degrees, particularly preferably 60 degrees to 120 degrees.

In relation to the fourteenth embodiment shown in FIG. 25, the advantage of slanting the joint row rather than being orthogonal to the shrink direction ED (WD) (i.e., θ=90 degrees) is from a design standpoint. However, there are other advantages as well. Next, its advantages will be explained.

That is, as can be seen from FIG. 25, the space between the joints 40, 40 can be increased on the orthogonal direction line. In the example of FIG. 12, in the first joint row A1 and the second joint row A2, the space between the joints 40, 40 is extremely narrow. As described above, the joining of the first sheet layer 20A and the second sheet layer 20B at the sheet joining portion 40 is desirably performed by joining means such as heat sealing, ultrasonic sealing, or other material welding.
In the case of continuous production, ultrasonic seal melting is performed between the anvil roll and the ultrasonic horn, but in order to prevent energy loss, the ultrasonic horn is also closely attached to the sheet along the entire axial direction of the anvil roll. For this reason, when forming a pattern with a large proportion of anvil roll projections, such as the joints 40, 40 along the generatrices that are in line contact, a large ultrasonic output is produced. Therefore, if an excessive contact force is applied along the line-contact busbars, the burden on the facility side is large.
On the other hand, in the case of the 14th embodiment shown in FIG. 25 (generally in the case of an inclined arrangement), the proportion of the joints located on the line in the orthogonal direction is small, and the line pressure is stable. The equipment burden is small, and stable operation is possible.

The joint portion 40 is formed with a length of 0.3 to 7.0 mm, preferably 0.5 to 5.0 mm, particularly preferably 0.7 to 2.5 mm, in the orthogonal direction. The width of the joint 40 is desirably 0.2 to 1.0 mm.
The rows of joints 40, 40 are formed with a formation pitch of 2.0 to 20.0 mm, preferably 2.0 to 15.0 mm, particularly preferably 2.0 to 10.0 mm, based on the expansion/contraction direction ED. be.

Furthermore, as the distance on the orthogonal basis determined by the interrelationship of adjacent joints 40, 40 in the joints 40, 40 ... row,
(Distance d between adjacent joints 40, 40) / (distance from one point of joint to corresponding point of adjacent joint: pitch) percentage is 5 to 60%, preferably 10 to 45 %, particularly preferably 20 to 35%.
If this percentage is too high, when applied to a product, the stretching stress in the width direction (stretching direction) is high, making it difficult to obtain an appropriate fit as a wearable article.
Also, if the percentage is too low, the possibility that the joints 40, 40 adjacent to each other in the orthogonal direction LD become continuous during the manufacturing process cannot be ruled out. This places an excessive burden on the equipment, hindering stable operation.
can

The shapes of the individual sheet joint portions 40 and the joint holes 31 in the natural length state can be appropriately determined in addition to the already-described rectangular shape elongated in the orthogonal direction. For example, as shown in FIG. 26, convex lens shape (see FIG. 26(a)), rhombic shape (see FIG. 26(b)), concave lens shape (see FIG. 26(c)), elliptical shape (see FIG. 26(d)) ), a perfect circle, a triangle, a polygon, a star, a cloud, or any other shape.

The joint hole 31 is mainly related to the shape of the joint portion 40 (41, 42, 43), the manufacturing stage, or the degree of expansion and contraction.

When the first sheet layer 20A and the second sheet layer 20B are joined at the sheet joining portion 40 through the joining holes 31 formed in the elastic film 30, at least the first sheet layer 20A and the second sheet layer 20B at the sheet joining portion 40 are bonded. It is desirable that the first sheet layer 20A and the second sheet layer 20B are not joined to the elastic film 30 except between the sheet layers 20B.

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

When the first sheet layer 20A and the second sheet layer 20B are joined through the joining holes 31 of the elastic film 30 at the sheet joining portion 40, the sheet joining portion 40 is formed by material welding. A first welding mode in which the first sheet layer 20A and the second sheet layer 20B are joined only by a melted and solidified material 20m of at least one of the first sheet layer 20A and the second sheet layer 20B (see FIG. 27(a)). )), and a second welding mode in which the first sheet layer 20A and the second sheet layer 20B are joined only by the melted and solidified material 30m of all or most of the elastic film 30 at the sheet joining portion 40 (see FIG. 27 ( b)), and a third welding mode (see FIG. 27(c)) in which both of these are combined, but the second and third welding modes are preferred.
Particularly preferably, the first sheet layer 20A and the second sheet layer 20B are partially melted and solidified 20m and all or most of the elastic film 30 at the sheet joint 40 is melted and solidified 30m. 20A and the second sheet layer 20B are joined. In the third welding mode shown in FIG. 29(b), the elastic film 30 shown in white is placed between the melted and solidified fibers 20m of the first sheet layer 20A or the second sheet layer 20B shown in black. While the melted solidified material 30m can be seen, in the first welding mode shown in FIG. can't see anything.

As in the first bonding mode and the third bonding mode, the first sheet layer 20A and the second sheet layer 20B are bonded to each other by using the molten and solidified material 20m of at least one of the first sheet layer 20A and the second sheet layer 20B as an adhesive. When joining the sheet layers 20B, it is preferable not to melt a part of the first sheet layer 20A and the second sheet layer 20B so that the sheet joining portion 40 is not hardened.
When the first sheet layer 20A and the second sheet layer 20B are non-woven fabrics, the core (the core ( Including not only the core in the conjugate fiber but also the central part of the monocomponent fiber) remains, but the surrounding part (including not only the sheath in the conjugate fiber but also the surface layer side part of the monocomponent fiber) is melted, or some Including morphologies in which the fibers are not melted at all, but the remaining fibers are all melted, or the core remains but its surrounding portion melts.

When the first sheet layer 20A and the second sheet layer 20B are joined using the melted and solidified material 30m of the elastic film 30 as an adhesive as in the second welding mode and the third welding mode, the peel strength is high. In the second welding mode, the melting point of at least one of the first sheet layer 20A and the second sheet layer 20B is higher than the melting point of the elastic film 30 and the heating temperature for forming the sheet joint portion 40. and the second sheet layer 20B, pressurize and heat the portion to be the sheet joint portion 40, and melt only the elastic film 30. As shown in FIG.
On the other hand, in the third welding mode, under the condition that the melting point of at least one of the first sheet layer 20A and the second sheet layer 20B is higher than the melting point of the elastic film 30, It can be produced by sandwiching the elastic film 30 and applying pressure and heat to the portion that will become the sheet joint 40 to melt at least one of the first sheet layer 20A and the second sheet layer 20B and the elastic film 30 .
From this point of view, the melting point of the elastic film 30 is preferably about 80 to 145°C, and the melting points of the first sheet layer 20A and the second sheet layer 20B are about 85 to 190°C, particularly about 150 to 190°C. is preferable, and 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 film 30 is preferably about 60 to 90.degree. Also, the heating temperature is preferably about 100 to 150.degree.

In the second welding mode and the third welding mode, when the first sheet layer 20A and the second sheet layer 20B are nonwoven fabrics, the melted and solidified material 30m of the elastic film 30 is formed at the sheet joints as shown in FIG. 28(c). 40 may penetrate between the fibers throughout the thickness direction of the first sheet layer 20A and the second sheet layer 20B, but as shown in FIG. As shown in FIG. 28(b), the flexibility of the sheet joint portion 40 is higher in the form in which the fibers of the first sheet layer 20A and the second sheet layer 20B hardly permeate.

FIG. 30 shows an example of an ultrasonic sealing device suitable for forming the second weld configuration and the third weld configuration. In this ultrasonic sealing device, when forming the sheet joint portion 40, between the anvil roll 60 having projections 60a formed on the outer surface in the pattern of the sheet joint portion 40 and the ultrasonic horn 61, the first sheet layer 20A, The elastic film 30 and the second sheet layer 20B are fed. At this time, for example, by making the feed transfer speed of the upstream elastic film 30 by the feed drive roll 63 and the nip roll 62 slower than the transfer speed after the anvil roll 60 and the ultrasonic horn 61, the feed drive roll 63 and the nip roll 62 The elastic film 30 is stretched to a predetermined elongation rate in the MD direction (machine direction, machine direction) along the path from the nip position by the anvil roll 60 and the ultrasonic horn 61 to the seal position by the ultrasonic horn 61 . The elongation rate of the elastic film 30 can be set by selecting the speed difference between the anvil roll 60 and the feeding drive roll 63, and can be set to about 300% to 500%, for example. 62 is a nip roll.
The first sheet layer 20A, the elastic film 30 and the second sheet layer 20B sent between the anvil roll 60 and the ultrasonic horn 61 are laminated in this order, and the protrusion 60a and the ultrasonic horn 61 While being pressurized between them, they are heated by the ultrasonic vibration energy of the ultrasonic horn 61 to melt only the elastic film 30, or to melt at least one of the first sheet layer 20A and the second sheet layer 20B and the elastic film 30. By doing so, the joint holes 31 are formed in the elastic film 30 and at the same time, the first sheet layer 20A and the second sheet layer 20B are joined through the joint holes 31 . Therefore, in this case, the area ratio of the sheet joint portion 40 can be selected by selecting the size, shape, spacing of the protrusions 60a of the anvil roll 60, the arrangement pattern in the roll length direction and the roll circumferential direction, and the like. can be done.

Although the reason why the joint hole 31 is formed is not necessarily clear, it is considered that the portion of the elastic film 30 corresponding to the protrusion 60a of the anvil roll 60 melts and separates from the surroundings to form the hole. At this time, as shown in FIGS. 9(a) and 11(a), the portions of the elastic film 30 between the joint holes 31 adjacent to each other in the stretch direction ED are separated from the portions on both sides of the stretch direction by the joint holes 31, as shown in FIGS. Since the support on both sides of the contraction direction is lost, the center side of the direction LD perpendicular to the contraction direction ED shrinks until it balances to the contraction direction center side within the range where continuity in the direction perpendicular to the contraction direction can be maintained. Then, the joint hole 31 expands in the expansion/contraction direction ED.

The constituent materials of the first sheet layer 20A and the second sheet layer 20B can be used without any particular limitation as long as they are in the form of sheets. The nonwoven fabric is not particularly limited as to what the raw material fibers are. For example, synthetic fibers such as olefins such as polyethylene and polypropylene, polyesters, and polyamides, regenerated fibers such as rayon and cupra, natural fibers such as cotton, and mixed fibers and composite fibers using two or more of these. etc. can be exemplified. Furthermore, the nonwoven fabric may be manufactured by any processing.
Examples of processing methods include known methods such as spunlace, spunbond, thermal bond, meltblown, needle punch, air through, and point bond methods. When a non-woven fabric is used, it is preferable that its basis weight is about 10 to 25 g/m ² . Also, part or all of the first sheet layer 20A and the second sheet layer 20B may be a pair of layers formed by folding one sheet of material and facing each other. For example, as shown in the illustrated embodiment, in the waist end portion 23, the second sheet layer 20B is used as the outer component, and the first sheet layer 20A is used as the folded portion 20C that is folded inward at the waist opening edge. , and the elastic film 30 is interposed therebetween, and in the other portions, the inner constituent material is the first sheet layer 20A, the outer constituent material is the second sheet layer 20B, and the elastic film 30 is interposed therebetween. can intervene. Of course, the constituent members of the first sheet layer 20A and the constituent members of the second sheet layer 20B are separately provided over the entire front-rear direction LD, and the constituent members of the first sheet layer 20A and the second sheet layer 20B are arranged without folding back the constituent members. An elastic film 30 can also be interposed between the components of layer 20B.

The elastic film 30 is not particularly limited. As long as it is a thermoplastic resin film that itself has elasticity, it can be a non-porous film or a film having a large number of holes or slits for ventilation. . 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-back direction LD (direction perpendicular to the stretching direction LD, CD direction) is 5 to 20 N / 35 mm, the width direction The elastic film 30 preferably has a tensile elongation of 450 to 1050% in the WD and a tensile elongation of 450 to 1400% in the longitudinal direction LD. Although the thickness of the elastic film 30 is not particularly limited, it is preferably about 20 to 40 μm.

(stretch area)
A region having the elastic sheet stretchable structure 20X in the exterior body 20 has a stretchable region that is stretchable in the width direction WD. In the stretchable region 80, the elastic film 30 has a linearly continuous portion along the width direction WD (for example, the region indicated by reference numeral 32 in FIG. 12), and the stretchable force of the elastic film 30 stretches the It is contracted and expandable in the width direction WD. More specifically, in a state in which the elastic film 30 is stretched in the width direction WD, the elastic film 30 is stretched at intervals in the width direction WD and in the front-rear direction LD (direction LD orthogonal to the stretch direction). By joining the first sheet layer 20A and the second sheet layer 20B through the joining holes 31 to form a large number of sheet joining portions 40, the elastic sheet stretchable structure 20X is formed, and the elastic film 30 is formed in the stretchable region 80. Such stretchability can be imparted by arranging the joint holes 31 so as to have a linearly continuous portion 32 along the width direction WD.

In the stretchable region, in the natural length state, the first sheet layer 20A and the second sheet layer 20B between the sheet joints 40 swell in the direction of separating from each other, forming shrinkage wrinkles 26 extending in the front-rear direction LD, and extending in the width direction WD. Even in the worn state in which it is stretched to some extent, the contraction wrinkles 26 are stretched but remain.

It is desirable that the elastic limit elongation in the width direction WD of the elastic region 80 is 200% or more (preferably 265 to 295%). The elastic limit elongation of the stretchable region 80 is substantially determined by the elongation rate of the elastic film 30 at the time of manufacture, but based on this, it decreases due to factors that inhibit contraction in the width direction WD. The main factor of such a hindrance is the ratio of the length L of the sheet joint portion 40 per unit length in the width direction WD, and the larger the ratio, the lower the elastic limit elongation. Normally, the length L of the sheet joints 40 has a correlation with the area ratio of the sheet joints 40 , so the elastic limit elongation of the elastic region 80 can be adjusted by the area ratio of the sheet joints 40 .

The area ratio of the sheet joints 40 in the stretchable region 80 and the area of each individual sheet joint 40 can be determined as appropriate, but in normal cases, it is preferable to set them within the following ranges.
Area of sheet joint 40: 0.14 to 3.5 mm ² (especially 0.14 to 1.0 mm ² )
Area ratio of sheet joint 40: 1.8 to 19.1% (especially 1.8 to 10.6%)

In this way, since the elastic limit elongation and elongation stress of the elastic region 80 can be adjusted by the area of the sheet joint portion 40, as shown in FIG. can be provided to change the fit depending on the part. In the form shown in FIG. 7, the area 81 extending obliquely along the base of the leg in the front body F and the edge area 82 of the leg opening have a higher area ratio of the sheet joints 40 than the other areas. Therefore, the extension stress is weak, and the area is flexibly stretchable. In addition, the ilium-facing region 83 of the back body B and the edge region 82 of the leg opening also have a higher area ratio of the sheet joint portion 40 than other regions, and therefore are weak in extension stress and flexibly stretchable. It has become.

(Non-stretch area)
A non-stretchable region 70 can be provided on at least one widthwise side 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 arrangement of the stretchable regions 80 and the non-stretchable regions 70 can be determined as appropriate. In the case of the outer body 20 of the underpants-type disposable diaper as in the present embodiment, the portion overlapping the absorbent body 13 is a region that does not require expansion and contraction. (It is desirable to include substantially the entire inner/outer fixing region 10B) as the non-stretchable region 70 . Of course, the non-stretchable region 70 can be provided from the region overlapping the absorbent body 13 to the region not overlapping the absorbent body 13 located in the width direction WD or the front-rear direction LD, and only the non-stretchable region in the region not overlapping the absorbent body 13. 70 can also be provided.

The non-stretchable region 70 is defined as a region where the elastic film 30 is continuous in the width direction WD but does not have a linearly continuous portion along the width direction WD due to the existence of the joining holes 31 . Therefore, in a state in which the elastic film 30 is stretched in the width direction WD, the first sheet layer 20A and the second sheet layer 20A and the second sheet layer 20A and the second sheet layer 20A are separated from each other through the joining holes 31 of the elastic film 30 in the width direction WD and the front-rear direction LD orthogonal thereto. Even if the entire elastic sheet stretchable structure 20X including both the stretchable regions 80 and the non-stretchable regions 70 is formed by bonding the two sheet layers 20B and forming a large number of sheet joints 40, the non-stretchable regions 70: Since the elastic film 30 is not linearly continuous along the width direction WD, the contractile force of the elastic film 30 hardly acts on the first sheet layer 20A and the second sheet layer 20B, and the stretchability is almost lost and the elastic limit is reached. Elongation is close to 100%.
In such a non-stretchable region 70, the first sheet layer 20A and the second sheet layer 20B are joined by a large number of sheet joints 40 arranged at intervals, and the sheet joints 40 are not continuous. , the loss of flexibility is prevented.

The arrangement pattern of the joint holes 31 in the elastic film 30 in the non-stretchable region 70 can be determined appropriately.
The area ratio of the sheet joints 40 in the non-stretchable region and the area of the individual sheet joints 40 can be determined as appropriate. It is preferable because the non-stretchable region 70 does not become hard due to the low area ratio of the joint portion 40 .
Area of sheet joint 40: 0.10 to 0.75 mm ² (especially 0.10 to 0.35 mm ² )
Area ratio of sheet joint 40: 4 to 13% (especially 5 to 10%)

In the above example, an elastic film is used as the elastic sheet. However, elastic nonwovens can also be used. Alternatively, an elastic nonwoven can be provided on one or both sides of the elastic film and interposed between the first sheet layer 20A and the second sheet layer 20B.

<Description of terms in the specification>
The following terms in the specification have the following meanings unless otherwise specified in the specification.
- "Front body" and "rear body" refer to the front and rear portions of the underpants-type disposable diaper, respectively, with respect to the center in the front-rear direction. In addition, the crotch part means the front-rear direction range including the front-rear direction center of the pants-type disposable diaper, and means the front-rear direction range of the portion having the constricted part when the absorbent body has the constricted part.
・"Elastic limit elongation" means the elongation at the elastic limit (in other words, the state in which the first sheet layer and the second sheet layer are completely unfolded) in the stretching direction ED, and the length at the elastic limit is the natural length. is expressed as a percentage when the is 100%.
・"Area ratio" means the ratio of the target portion to the unit area, and the target portion (for example, the sheet joint portion 40, the opening of the joint hole 31, the ventilation hole ) is expressed as a percentage by dividing the total area of the target area by the area of the target area. Especially, the “area ratio” in the area having a stretchable structure means the area ratio in the state stretched to the elastic limit in the stretch direction ED. It is something to do. In a form in which a large number of target portions are provided at intervals, it is desirable to determine the area ratio by setting the target region to a size that includes 10 or more target portions.
- "Elongation rate" means a value when the natural length is taken as 100%.
- "Matsuke" is measured as follows. After pre-drying the sample or test piece, it is left in a test room or apparatus under standard conditions (test location: temperature 23±1° C., relative humidity 50±2%) to a constant weight. Pre-drying refers to making a sample or test piece constant weight in an environment at a temperature of 100°C. Fibers with an official moisture content of 0.0% do not need to be pre-dried. Using a sampling template (100 mm x 100 mm), a sample with dimensions of 100 mm x 100 mm is cut from the constant weight specimen. The weight of the sample is measured, multiplied by 100 to calculate the weight per square meter, and used as basis weight.
・The "thickness" of the absorber is measured by Ozaki Seisakusho Co., Ltd.'s thickness measuring instrument (Peacock, dial thickness gauge large type, model JB (measuring range 0 to 35 mm) or model K-4 (measuring range 0 to 50 mm)). Measure by placing the sample and the thickness gauge horizontally.
• "Thickness" other than the above is automatically measured using an automatic thickness gauge (KES-G5 handy compression measurement program) under the conditions of a load of 0.098 N/cm ² and a pressurized area of 2 cm ² .
・ "Tensile strength" and "tensile elongation (breaking elongation)" are in accordance with JIS K7127: 1999 "Plastics - Test method for tensile properties -" except that the test piece is a rectangular shape with a width of 35 mm and a length of 80 mm. means a value measured with an initial chuck interval (distance between gauge lines) of 50 mm and a tensile speed of 300 mm/min. As a tensile tester, for example, AUTOGRAPH AGS-G100N manufactured by SHIMADZU can be used.
・"Elongational stress" is determined according to JIS K7127:1999 "Plastics - Tensile property test method -" by a tensile test with an initial chuck interval (marked line distance) of 50 mm and a tensile speed of 300 mm / min. , 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 subject. The test piece is preferably rectangular with a width of 35 mm and a length of 80 mm or more, but if a test piece with a width of 35 mm cannot be cut, create a test piece with a width that can be cut, converted to In addition, even if the target area is small and sufficient test pieces cannot be collected, if the magnitude of the tensile stress is compared, it is possible to compare at least a small test piece as long as the test piece of the same size is used. . As a tensile tester, for example, AUTOGRAPH AGS-G100N manufactured by SHIMADZU can be used.
- "Unfolded state" means a flat unfolded state without contraction or slack.
・Unless otherwise specified, the dimensions of each part mean the dimensions in the unfolded state, not in the natural length state.
・If there is no description about environmental conditions for testing and measurement, the test and measurement shall be performed in a laboratory or equipment under standard conditions (test location: temperature 23±1°C, relative humidity 50±2%). do.

As long as it has a stretchable region to which the elastic sheet stretchable structure can be applied, the present invention can be applied to various disposable diapers such as tape type and pad type, sanitary napkins, swimming It can be used for general disposable wearing articles such as disposable wearing articles for playing in water.

DESCRIPTION OF SYMBOLS 10... Inner body, 10B... Inner-outer fixing area, 11... Top sheet, 12... Liquid-impermeable sheet, 13... Absorbent body, 13N... Constricted part, 14... Packaging sheet, 17... Non-absorbent side part, 20... Exterior body 20A First sheet layer 20B Second sheet layer 20C Folded portion 20X Elastic sheet elastic structure 21 Side seal portion 23 Waist edge 24 Waist elastic member 25F, 25f Contraction wrinkles 26 Contraction wrinkles 29 Leg circumference line 30 Elastic film 31 Joining hole 33 Ventilation hole 40 Sheet joint (first joint) 41 Second joint 42 Third joint portion 43 Fourth joint portion 70 Non-stretchable region 80 Stretchable region 90 Three-dimensional gather 93 Falling portion 94 Free portion 95 Gathered sheet 96 Gathered elastic member B Back body, ED: Elastic direction (width direction), F: Front body, L: Intermediate part, LD: Orthogonal direction (front-rear direction), T: Waist part.

Claims (4)

An elastic sheet is interposed between a first air-permeable sheet layer and a second air-permeable sheet layer, and the first sheet layer and the second sheet layer are arranged with a gap therebetween. and an elastic sheet elastic structure joined through a joint hole penetrating the elastic sheet or through the elastic sheet,
The stretchable region indicating the stretchable structure of the elastic sheet is stretchable in the stretchable direction due to the stretching force of the elastic sheet,
wherein the joints form rows of joints spaced along an alignment direction that intersects the stretch direction;
A large number of the joint rows are formed at intervals in the stretching direction,
A third joint row is formed between the adjacent first joint row and second joint row,
The joints forming the first joint row, the joints forming the second joint row, and the joints forming the third joint row are all oriented in the same direction along the alignment direction. and
the spacing of at least a part of the third joint row in the alignment direction is longer than the spacing in the alignment direction of the first joint row and the second joint row on both sides of the third joint row;
The angle at which the alignment direction intersects the stretch direction is within a range of 45 degrees to 135 degrees, and the alignment direction is inclined with respect to the stretch direction.
An elastic member characterized by: 3. The joints of the third joint row, together with the joints of the adjacent first joint row and the joints of the second joint row, form intersecting rows aligned in a direction transverse to the joint rows. 2. The elastic member according to 1. 3. The elastic member of claim 2, wherein the cross rows are formed in a plurality of rows spaced apart in said alignment direction. An integrated outer body extending from the front body to the back body, or an outer body provided separately on the front body and the back body, and an inner body attached to the middle part in the width direction of the outer body and extending over both front and rear sides of the crotch part. , a side seal portion in which both side portions of the exterior body of the front body and both side portions of the exterior body of the back body are respectively joined, and a waist opening and a pair of left and right leg openings. A pants-type disposable wearing article having the elastic member according to item 1,
The outer body of at least one of the front body and the back body has the elastic sheet over a width direction range corresponding to between the side seal portions in at least a partial range in the front-rear direction. is provided as
A pants-type disposable wearing article having the elastic member.

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