JP7387253B2 - Disposable wearing items - Google Patents

Description

TECHNICAL FIELD The present invention relates to a disposable wearing article equipped with an elastic member that is elastically expanded and contracted by an elastic sheet such as an elastic film.

In disposable wearing articles such as disposable diapers, in order to improve the fit to the body surface, it is common to add elasticity to appropriate areas such as around the legs and torso. Conventionally, as a method for imparting elasticity, a method of attaching an elongated elastic member such as a rubber thread in a state in which it is stretched in the longitudinal direction has been widely adopted, but when it is desired to impart elasticity to a certain width. In this method, rubber threads are arranged and fixed at widthwise intervals. In addition, a method of attaching an elastic sheet in a stretched state in the direction of imparting elasticity has also been proposed as a method for improving the fit as a surface. (For example, see Patent Document 1 and Patent Document 2).

In the elastic member including this elastic sheet, the elastic sheet is laminated between the first sheet layer and the second sheet layer, and the elastic sheet is stretched in the elastic direction. The layers are welded through bonding holes formed in the elastic sheet at a number of point-like sheet bonding portions arranged at intervals in the direction of expansion and contraction and in the direction orthogonal thereto. In the natural length state of this elastic member, as the elastic sheet contracts between the sheet joints, the interval between the sheet joints becomes narrower, and the distance between the sheet joints in the first sheet layer and the second sheet layer becomes narrower. Folds are formed that extend in a direction transverse to the stretching direction. On the contrary, during stretching, as the elastic sheet stretches between the sheet joints, the interval between the sheet joints and the folds in the first sheet layer and the second sheet layer widen, and the first sheet layer and the second sheet layer are completely stretched. It becomes possible to stretch elastically to the unfolded state. The stretch area made of this elastic sheet not only has excellent surface fit, but also has no bond between the first sheet layer and the second sheet layer and the elastic sheet, and also has no bond between the first sheet layer and the second sheet layer. It has the advantage that it is extremely flexible because it is extremely small in number, and that the joining holes in the elastic sheet also contribute to improving air permeability.

On the other hand, when adopting a stretchable member including the above-mentioned elastic sheet in a disposable wearing article such as a pant-type disposable diaper, it is necessary to extend the stretchable area as widely as possible using the same elastic sheet in order to simplify the structure and reduce material costs. It is desirable to form a

Additionally, in general, in disposable wearable articles, a strong tightening force is required at the waist, whereas it is desirable to have a weaker tightening force in the area adjacent to the waist located between the front and back waists. .

However, parts having the same elastic sheet cannot normally change the tightening force in a direction perpendicular to the direction of expansion and contraction. Therefore, it is difficult to provide the waist portion with a stronger tightening force than the portions adjacent to the waist. As one method to solve this problem, Patent Document 3 proposes increasing the number of layers of elastic sheets by folding back the elastic sheets at the waist, but there is a problem that the thickness of the waist increases. There is. As another solution, it has been proposed to adopt a structure that has been widely used in the past, such as providing an elongated elastic member only at the waist, but a simpler solution using only an elastic sheet is proposed. desired.

Special Publication No. 2004-532758 Japanese Patent Application Publication No. 2016-189932 Japanese Patent Application Publication No. 2016-187387

Therefore, the main problem of the present invention is to provide a disposable elastic sheet that can provide elasticity to the waist area and areas adjacent to the waist, but can tighten the waist area more strongly without increasing the thickness of the waist area. It's about providing diapers.

A stretchable member that solves the above problems, a disposable wearing article having this stretchable member, and a method for manufacturing the stretchable member are as follows.
<First aspect>
A disposable wearing article comprising an elastic member having a waist portion and a waist adjacent portion adjacent to the waist portion,
The waist part and the waist adjacent part of the elastic member have a first sheet layer, a second sheet layer, and an elastic sheet interposed between them,
The elastic sheet is continuous from the waist portion to a portion adjacent to the waist,
The first sheet layer and the second sheet layer are welded through a joining hole penetrating the elastic sheet at spaced apart sheet joining parts,
The waist portion and the waist adjacent portion of the elastic member have an elastic region that is contracted in the width direction due to contraction of the elastic sheet and can be expanded in the width direction,
In the elastic region of the waist portion, in the unfolded state, a non-porous band in which the portion without joining holes is continuous along the width direction, and a joining band in which the sheet joining portions are arranged at intervals in the width direction. are provided alternately and repeatedly in the orthogonal direction perpendicular to the width direction,
The elastic region adjacent to the waist is provided with a non-porous band in which the portion without the joining hole is continuous along the width direction in the unfolded state, and the non-porous band of the plurality of non-porous bands in the waist portion The dimension in the orthogonal direction is longer than the dimension in the orthogonal direction of the imperforate band in the portion adjacent to the waist, or the imperforate band is not provided in the elastic region of the portion adjacent to the waist .
A disposable wearing article characterized by:

(effect)
The tightening force exerted by a stretchable member including an elastic sheet is almost determined by the stretching stress of the elastic sheet and the contact area, and the strength of the stretching stress of the elastic sheet is basically determined by the cross-sectional area of the elastic sheet (if the thickness is constant, the width direction (dimension in the orthogonal direction). Furthermore, in this stretchable structure, the continuity of the elastic sheet is lost in the portion having the sheet joint. Therefore, in this stretchable structure, the cross-sectional area of the elastic sheet that contributes to the stretching stress is basically determined by the dimension of the imperforate zone in the orthogonal direction. Here, in this elastic structure, the orthogonal dimension of the plurality of imperforate bands in the waist part is longer than the orthogonal direction dimension of the imperforate bands in the part adjacent to the waist, or the non-porous belt is in the part adjacent to the waist. Not provided. Therefore, although the disposable wearing article of this embodiment is stretchable by the same elastic sheet covering the waist region and adjacent waist regions, there is no increase in the thickness of the waist region. Even if it is not layered, it can tighten the waist area more strongly.

<Second aspect>
The elastic sheet is an elastic film with a thickness of 20 to 40 μm,
The dimension of the plurality of imperforate bands in the waist portion in the orthogonal direction is 2 to 5 mm,
The dimension in the orthogonal direction of the non-porous band in the waist adjacent portion is 0.25 times or less the dimension in the orthogonal direction of the plurality of non-porous bands in the waist portion, or There is no imperforate zone,
Disposable wearing article according to the first aspect.

(effect)
The dimension in the orthogonal direction of the non-porous bands in the waist portion is not particularly limited, but if the elastic sheet is an elastic film with a thickness like the one in this embodiment, the dimension in the orthogonal direction of the plurality of non-porous bands in the waist portion, etc. is preferably within the scope of this embodiment.

<Third aspect>
The joining hole located in the joining zone of the waist portion has a natural length shape that is elongated in the width direction and has a straight upper edge and a lower edge.
The disposable wearing article according to the first or second aspect.

(effect)
Although the shape of the joining hole is not particularly limited, in this stretchable structure, when comparing the used area of the same elastic sheet, the shorter the dimension in the orthogonal direction of the joining hole, the stronger the tightening force at the waist part. This is preferable because it allows for Further, in this case, the area of the sheet joint portion 40 can be reduced while the first sheet layer and the second sheet layer are joined over a wide range, resulting in excellent flexibility and air permeability.

<Fourth aspect>
The dimension in the orthogonal direction of the imperforate band of the waist portion becomes longer as it approaches the edge of the waist opening.
The disposable wearing article according to any one of the first to third aspects.

(effect)
In this aspect, the closer the edge of the waist portion is, the higher the adhesion to the skin is, so it is suitable when the adhesion of the waist portion is important.

<Fifth aspect>
The dimension in the orthogonal direction of the imperforate band of the waist portion becomes shorter as it approaches the edge of the waist opening.
The disposable wearing article according to any one of the first to third aspects.

(effect)
In this aspect, the tightening force becomes weaker closer to the edge of the waist portion, so that the disposable wearing article can be grasped by easily inserting a finger between the waist portion and the skin while being worn. Therefore, for example, in the case of a pants-type disposable diaper, the waist portion can be easily grasped when the diaper is worn, and the work of putting up and lowering the pants-type disposable diaper becomes easy.

<Sixth aspect>
The dimension in the orthogonal direction of the imperforate band of the waist portion becomes longer as it approaches the edge of the waist opening in the middle of the width direction of the waist portion, and becomes shorter as it approaches the edge of the waist opening outside of this in the width direction. has become,
The disposable wearing article according to any one of the first to third aspects.

(effect)
In this aspect, the dimension in the orthogonal direction of the non-porous band of the waist portion changes depending on the position in the width direction. Here, in this aspect, although the area of the elastic sheet is large in the portion where the non-porous band has a long dimension in the orthogonal direction, at least one of its width directions has a short dimension in the orthogonal direction, so the tightening force is weak. As a result, in this aspect, in the part that tightens the abdomen, the tightening force becomes weaker as it gets closer to the edge of the waist part, and in the part that contacts the ilium, the tightening force becomes weaker as it gets farther from the edge of the waist part, so that the fit of the waist part is improved. becomes even better.

<Seventh aspect>
A disposable wearing article comprising an elastic member having a waist portion and a waist adjacent portion adjacent to the waist portion,
The waist part and the waist adjacent part of the elastic member have a first sheet layer, a second sheet layer, and an elastic sheet interposed between them,
The first sheet layer and the second sheet layer are welded through a joining hole penetrating the elastic sheet at spaced apart sheet joining parts,
The waist portion and the waist adjacent portion of the elastic member have an elastic region that is contracted in the width direction due to contraction of the elastic sheet and can be expanded in the width direction,
The elastic region of the waist portion includes a non-porous band in which a portion without the sheet joint portion is continuous along the width direction in the unfolded state, and a joint in which the sheet joint portions are arranged at intervals in the width direction. The bands are alternately and repeatedly provided in the orthogonal direction orthogonal to the width direction,
In each non-jointed band in the elastic region of the waist portion, an elastic band in which the elastic sheet is divided in the orthogonal direction is arranged in the non-porous band ,
The elastic region adjacent to the waist is provided with a non-porous band in which the portion without the joining hole is continuous along the width direction in the unfolded state, and the elastic band of the plurality of elastic bands in the waist portion is provided with The dimension in the orthogonal direction is longer than the dimension in the orthogonal direction of the imperforate band in the portion adjacent to the waist, or the imperforate band is not provided in the elastic region of the portion adjacent to the waist .
A disposable wearing article characterized by:

(effect)
In the seventh aspect, the elastic band at the waist portion is formed by dividing an elastic sheet, and the dimension in the orthogonal direction of the plurality of elastic bands at the waist portion is equal to orthogonal to the non-porous band at the portion adjacent to the waist. It is longer than the specified size, or there is no imperforate band adjacent to the waist. Therefore, although a single elastic sheet imparts elasticity to the waist area and the area adjacent to the waist, there is no increase in the thickness of the waist area, that is, the elastic sheet is a single layer (not multiple layers due to folding, etc.). However, the waist can be tightened even more tightly. Furthermore, since the elastic sheet is not continuous from the waist part to the part adjacent to the waist, and an elastic band in which the elastic sheet is divided is provided in the elastic region of the waist part, the appearance of the waist part is different from the appearance of the part adjacent to the waist, and This makes it possible to make the appearance of the part stand out.

<Eighth aspect>
The elastic sheet is an elastic film with a thickness of 20 to 40 μm,
The dimension of the plurality of elastic bands in the waist portion in the orthogonal direction is 2 to 5 mm,
The dimension in the orthogonal direction of the non-porous band adjacent to the waist is 0.25 times or less the dimension in the orthogonal direction of the plurality of elastic bands in the waist, or No holes are provided,
Disposable wearing article according to the seventh aspect.

<Ninth aspect>
An integral exterior body spanning from the front body to the back body, or an exterior body provided separately on the front body and the back body, and an interior body attached to the widthwise middle part of this exterior body and extending across both front and rear sides of the crotch area. , a pants-type disposable wearing article comprising a side seal portion in which both sides of the exterior body in the front body and both sides of the exterior body in the back body are respectively joined, a waist opening and a pair of left and right leg openings. hand,
the exterior body is the elastic member;
The disposable wearing article according to any one of the first to eighth aspects.

(effect)
The above-mentioned elastic member is suitable for the exterior body of a pants-type disposable wearing article as in the present embodiment.

According to the present invention, although a single elastic sheet imparts elasticity to the waist region and adjacent regions, the waist region can be tightened more strongly without increasing the thickness of the waist region. is brought about.

FIG. 2 is a plan view (inner side) of the pant-type disposable diaper in an unfolded state. FIG. 2 is a plan view (outer surface side) of the pant-type disposable diaper in an unfolded state. FIG. 2 is a plan view showing only the main parts of the pant-type disposable diaper in an unfolded state. (a) is a sectional view taken along line CC in FIG. 1, and (b) is a sectional view taken along line EE in FIG. 2 is a sectional view taken along line AA in FIG. 1. FIG. 2 is a sectional view taken along line BB in FIG. 1. FIG. (a) is a plan view of a main part of the elastic region, (b) is a cross-sectional view taken along line DD in (a), (c) is a cross-sectional view in the attached state, and (d) is a cross-sectional view in the natural length state. FIG. 3 is a cross-sectional view schematically showing a cross section of a main part of the exterior body which has been expanded to a certain extent. (a) is a plan view of a main part of the elastic region, (b) is a cross-sectional view taken along line DD in (a), (c) is a cross-sectional view in the attached state, and (d) is a cross-sectional view in the natural length state. FIG. 3 is a plan view showing various arrangements of sheet joints. FIG. 3 is a plan view of the stretchable region in an expanded state. FIG. 3 is a plan view showing an enlarged main part of the stretchable region in an expanded state; FIG. 3 is a plan view showing an enlarged main part of the stretchable region in its natural length state. (a) is a cross-sectional view taken along the line DD in FIG. 12, and (b) is a cross-sectional view in the natural length state. FIG. 3 is a plan view of the stretchable region in an expanded state. FIG. 3 is a plan view showing an enlarged main part of the stretchable region in an expanded state; FIG. 3 is a plan view showing an enlarged main part of the stretchable region in its natural length state. FIG. 2 is a schematic diagram of an ultrasonic sealing device. FIG. 3 is a plan view showing an enlarged main part of the stretchable region in an expanded state; FIG. 3 is a plan view showing an enlarged main part of the stretchable region in an expanded state; FIG. 3 is a plan view showing an enlarged main part of the stretchable region in an expanded state; FIG. 3 is a plan view showing an enlarged main part of the stretchable region in an expanded state; FIG. 3 is a plan view showing an enlarged main part of the stretchable region in an expanded state; FIG. 3 is a plan view showing an enlarged main part of the stretchable region in an expanded state;

Hereinafter, a disposable wearing article including an elastic member including an elastic sheet will be explained in detail based on an example of a pants-type disposable diaper shown in the accompanying drawings. Note that the dotted portion in the cross-sectional view indicates a bonding means such as hot melt adhesive.

1 to 6 show a pants-type disposable diaper. The symbol LD (vertical 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 exterior body 20 that forms a front body F and a back body B, and an interior body 10 that is fixed and integrated with the inner surface of this exterior body 20. The interior body 10 includes an absorbent body 13 interposed between a liquid-permeable top sheet 11 and a liquid-impermeable sheet 12. During manufacturing, after the back surface of the interior body 10 is joined to the inner surface (upper surface) of the exterior body 20 by a joining means such as hot melt adhesive, the interior body 10 and the exterior body 20 are attached to the front body F and the back body B. The waist opening and the left and right sides are folded at the center of the front-rear direction LD (longitudinal direction), which is the boundary between the This is a pants-type disposable diaper with a pair of leg openings.

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

As the top sheet 11 that covers the front side (skin side) of the absorber 13, a perforated or non-perforated nonwoven fabric, a porous plastic sheet, or the like is suitably used. Here, the nonwoven fabrics that can be used for this product, including the top sheet 11, are as follows. In other words, the constituent fibers of the nonwoven fabric include, for example, olefin-based fibers such as polyethylene, polypropylene, or copolymers thereof (e.g., polyethylene or copolymers containing ethylene as a copolymer component), synthetic fibers such as polyester-based, polyamide-based fibers (single-component fibers), etc. In addition to composite fibers such as core-sheath fibers, recycled fibers such as rayon and cupra, natural fibers such as cotton, etc. can be selected without particular limitation, and a mixture of these can also be used. In order to increase the flexibility of the nonwoven fabric, it is preferable that the constituent fibers be crimped fibers. In addition, even if the constituent fibers of a nonwoven fabric are hydrophilic fibers (including those made hydrophilic by a hydrophilizing agent), they may be hydrophobic fibers or water-repellent fibers (water-repellent fibers made water-repellent by a water-repellent agent). ). In addition, nonwoven fabrics generally vary depending on the fiber length, sheet forming method, fiber binding method, and laminated structure. It is classified into nonwoven fabrics, point bonded nonwoven fabrics, laminated nonwoven fabrics (SMS nonwoven fabrics with a meltblown layer sandwiched between spunbond layers, SMMS nonwoven fabrics, etc.), and any of these nonwoven fabrics can be used.

As the liquid-impermeable sheet 12 covering the back side (non-skin contact side) of the absorbent body 13, a liquid-impermeable plastic sheet such as polyethylene or polypropylene can be used, and has moisture permeability in particular from the viewpoint of preventing stuffiness. 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 the sheet in uniaxial or biaxial directions can be suitably used.

The absorbent material 13 may be a known material, such as a stack of pulp fibers, an aggregate of filaments such as cellulose acetate, or a material based on nonwoven fabric, mixed with or fixed with a superabsorbent polymer as necessary. can be used. This absorbent body 13 can be packaged with a packaging sheet 14 having liquid permeability and liquid retention properties, such as crepe paper, if necessary, in order to maintain the shape and polymer.

The shape of the absorbent body 13 is formed into a substantially hourglass shape with a constricted portion 13N in the crotch region that is narrower than both the front and rear sides. The dimensions of the constriction portion 13N can be determined as appropriate, but the length of the constriction portion 13N in the front-rear direction can be approximately 20 to 50% of the total length of the diaper, and the width of the narrowest portion is approximately 40% of the total width of the absorbent body 13. It can be about 60%. In the case of having such a constricted portion 13N, if the planar shape of the interior body 10 is approximately rectangular, there is a blank area without the absorbent body 13 in a portion of the interior body 10 that corresponds to the constricted portion 13N of the absorber 13. An absorbent body side portion 17 is formed.

The liquid-impermeable sheet 12 is folded back together with the top sheet 11 on both sides of the absorber 13 in the width direction. As the liquid-impermeable sheet 12, it is desirable to use an opaque sheet so as to prevent brown stains such as feces and urine from coming out. For opacity, it is preferable to use plastics in which pigments and fillers such as calcium carbonate, titanium oxide, zinc oxide, white carbon, clay, talc, and barium sulfate are added internally to form a film.

Three-dimensional gathers 90 that fit around the legs are formed on both sides of the interior body 10. As shown in FIGS. 5 and 6, the three-dimensional gathers 90 includes a fixing part 91 fixed to the side of the back surface of the interior body 10, and a fixing part 91 that extends from the fixing part 91 to the side of the interior body 10. The main body part 92 extends up to the sides of the surface of the body part 92, and the front and rear ends of the main body part 92 are laid down and attached to the sides of the surface of the interior body 10 (in the illustrated example, the top sheet 11) using hot melt adhesive 95b or the like. It has a fixed collapsed portion 93 and a free portion 94 that is not fixed between the collapsed portions 93. Each of these parts is formed by a gathered sheet 95 that is a double sheet made by folding back a sheet of nonwoven fabric or the like. The gathered sheet 95 is attached over the entire front and back direction of the interior body 10, with the folding portion 93 provided on the front and rear sides of the non-absorbent side portion 17, and the free portion 94 provided on both front and rear sides of the non-absorbent side portion 17. It has been extended. Further, between the double gather sheets 95, a gather elastic member 96 is arranged at the tip of the free portion, etc. The gather elastic member 96 is for raising the free portion 94 by 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, and for example, as in the example shown in FIGS. Although the gather elastic member 96 is adhesively fixed to the gather sheet 95 and the opposing surfaces of the gather sheet 95 are joined, there is no hot melt adhesive at the position of the gather elastic member 96 in the collapsed portion 93, and therefore the gather elasticity is It is possible to adopt a structure in which the member 96 and the gather sheet 95 are not bonded to each other, and the opposing surfaces of the gather sheet 95 are not bonded at the position where the gather elastic member 96 is provided.

As the gather elastic member 96, commonly used materials such as styrene rubber, olefin rubber, urethane rubber, ester rubber, polyurethane, polyethylene, polystyrene, styrene butadiene, silicone, and polyester can be used. Further, in order to make it difficult to see from the outside, it is preferable that the thickness be 925 dtex or less, the tension be 150 to 350%, and the interval be 7.0 mm or less. In addition, 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 gather sheet 95 is coated with a silicone-based, paraffin metal-based, alkylchromic chloride-based water repellent, etc. to prevent the permeation of urine, etc., prevent rashes, and improve the feel (dry feeling) on the skin. It is desirable to use water-repellent treated nonwoven fabric.

As shown in FIGS. 3 to 6, the back surface of the interior body 10 is bonded to the inner surface of the exterior body 20 in the inner and outer fixing areas 10B (shaded areas) using a hot melt adhesive or the like. The inner and outer fixing regions 10B can be determined as appropriate, and can be formed over almost the entire width direction WD of the interior body 10, but it is preferable that both ends in the width direction are not fixed to the exterior body 20.

(Example of structure of exterior body)
The exterior body 20 has at least a waist circumference T of the front body F and a waist circumference T of the back body B, and in the illustrated example, between the waist circumference T of the front body F and the waist circumference T of the back body B. It further has an intermediate portion L that extends in the front-rear direction. The waist circumference T is a range in the front-rear direction that includes the side seal portions 21. The waist portion T has a waist portion 23 that forms the edge of the waist opening. A portion adjacent to at least one of the waist portion 23 of the front body F and the waist portion 23 of the back body B is the waist adjacent portion 22. Normally, when there is a boundary in the waist circumference T where the stretching stress (contraction force during stretching) in the width direction WD changes, the waist opening side is the waist opening side of the boundary closest to the waist opening side, and such a boundary If there is no waist opening side of the absorbent body 13 or the inner body 10, the waist portion 23 becomes the waist opening side. These dimensions in the orthogonal direction XD vary depending on the size of the product and can be determined as appropriate. For example, the dimension in the orthogonal direction XD of the waist portion 23 can be 20 to 40 mm. Further, both side edges of the intermediate portion L are constricted in a U-shape or a curved shape so as to follow the circumference of the wearer's legs, and these are the portions that follow the circumference of the wearer's legs. As shown in the illustrated example, the side edges of the exterior body 20 may be located closer to the center in the width direction than the side edges of the interior body 10 in the crotch region, or may be located on the outer side in the width direction.

The illustrated example exterior body 20 has a first sheet layer 20A and a second sheet layer 20B, as shown in FIGS. 2 and 4 to 6, except for the intermediate portion L in the longitudinal direction LD. and an elastic sheet 30 interposed between them. In other words, the exterior body 20 is a telescopic member. Further, as shown in FIGS. 7, 9, etc., the first sheet layer 20A and the second sheet layer 20B have bonding holes 31 that penetrate the elastic sheet 30 at a large number of sheet bonding portions 40 arranged at intervals. It is joined through. Hereinafter, the structure in which the first sheet layer 20A, the second sheet layer 20B, and the elastic sheet 30 are laminated will also be referred to as an elastic sheet stretchable structure 20X.

The planar shape of the exterior body 20 is such that the middle part L is constricted so that both widthwise edges 29 of the middle part L form leg openings (the width of the middle part L is narrower than the width of the waist circumference part T). ing). The exterior body 20 may be formed of a front body F and a back body B separately, 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 area.

The elastic sheet stretchable structure 20X does not need to be provided in a part of the waist adjacent part 22 as long as it continues from the waist part 23 to the waist adjacent part 22 among the front and rear waist parts 23 and the part located between them. For example, like the illustrated example of the exterior body 20, a structure may be adopted in which the elastic sheet 30 is not provided only in the middle of the intermediate portion L in the longitudinal direction LD, a structure in which the elastic sheet 30 is not provided over the entire intermediate portion L, or a structure in which the elastic sheet 30 is not provided over the entire intermediate portion L, or A structure may be adopted in which the elastic sheet 30 is not provided in a part of the crotch side of the portion T. Of course, the elastic sheet stretchable structure 20X may continue over the entire exterior body 20 including the intermediate portion L.

(Joint structure of sheet joint)
When the first sheet layer 20A and the second sheet layer 20B are joined through the joining hole 31 formed in the elastic sheet 30, at least the first sheet layer 20A and the second sheet layer 20B at the sheet joining section 40 are joined through the joining hole 31 formed in the elastic sheet 30. 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 joining hole 31 of the elastic sheet 30 at the sheet joining section 40, both the first sheet layer 20A and the second sheet layer 20B are melted at the sheet joining section 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 joint portion 40. Furthermore, a molten and solidified product of the elastic sheet 30 may be sandwiched within the sheet joint portion 40.

Even if the first sheet layer 20A and the second sheet layer 20B are uniformly melted and solidified over the entire thickness direction and plane direction in the sheet joint portion 40 as in the example shown in FIG. 8(a), the first sheet layer 20A and the second sheet layer 20B are ) It may be melted and solidified non-uniformly as shown by the dotted gradation in (c). For example, the degree of melting of the first sheet layer 20A and the second sheet layer 20B may be lower toward the outer side in the thickness direction of the sheet joint portion 40, as in the example shown in FIG. 8(b). 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 joint 40, and the first sheet layer 20A and the second sheet layer 20B are not melted on the surface of the sheet joint 40. A state in which the melted and solidified material of the sheet layer 20B and unmelted fibers are mixed, and a state 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 joint portion 40, but the fibers are not melted. Includes conditions of varying degrees.

With or without a change in the degree of melting in the thickness direction in the sheet joint part 40, the first sheet layer 20A and the second sheet layer 20B are formed in the sheet joint part 40 as in the example shown in FIG. 8(c). The degree of melting may be lower toward the peripheral edge. 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 edge of the sheet joint 40 (however, the melted and solidified material of the elastic sheet 30 described later is not melted). ), a state in which the melted and solidified products of the first sheet layer 20A and the second sheet layer 20B and unmelted fibers are mixed at the peripheral edge of the sheet joint 40, and the plane of the sheet joint 40 This includes a state in which the fibers of the first sheet layer 20A and the second sheet layer 20B are melted throughout the direction, but the degree of melting changes.

In addition, in these conditions, the melting of the fibers of the first sheet layer 20A and the second sheet layer 20B includes not only the entire fiber melting but also the core of the fiber (not only the core of composite fibers but also the monocomponent fibers). (including the central portion of the composite fiber) remains, but the surrounding portion (including not only the sheath in the composite fiber but also the surface layer portion of the monocomponent fiber) is melted.

In addition, in a state where the melted and solidified material of the elastic sheet 30 remains in the sheet joint portion 40, there is a gap between the first sheet layer 20A or its melted and solidified layer and the second sheet layer 20B or its melted and solidified layer. A state in which the first sheet layer 20A and the second sheet layer 20B remain in a layered form without being mixed together, a state in which the first sheet layer 20A and the second sheet layer 20B are mixed with those that melt and solidify, and a state in which the first sheet layer 20A and the second sheet layer 20B do not melt and solidify. or between the remaining fibers (including the core) in the one of the first sheet layer 20A and the second sheet layer 20B that is melted and solidified.

The state in which the melted and solidified product of the elastic sheet 30 remains in the sheet joint portion 40 occurs when 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 the portion that will become the sheet joint portion 40 is pressurized and heated to bond at least one of the first sheet layer 20A and the second sheet layer 20B to the elastic sheet 30. It can be manufactured by melting.

In this case, the melting point of the elastic sheet 30 is preferably about 80 to 145°C, and the melting point of the first sheet layer 20A and second sheet layer 20B is preferably about 85 to 190°C, particularly about 150 to 190°C. It is preferable that the difference between the melting points of the first sheet layer 20A and the second sheet layer 20B and the melting point of the elastic sheet 30 is about 60 to 90°C. Further, the heating temperature is preferably about 100 to 150°C.

FIG. 18 shows an example of a suitable ultrasonic sealing device. In this ultrasonic sealing device, when forming the sheet joint 40, the first sheet layer 20A, The elastic sheet 30 and the second sheet layer 20B are fed. At this time, for example, by making the feeding speed of the upstream elastic sheet 30 by the feeding drive roll 63 and the nip roll 62 slower than the feeding speed of the anvil roll 60 and the ultrasonic horn 61 and subsequent parts, the feeding drive roll 63 and the nip roll 62 The elastic sheet 30 is stretched in the MD direction (machine direction, flow direction) to a predetermined elongation rate along the path from the nip position by the anvil roll 60 and the sealing position by the ultrasonic horn 61. The elongation rate of the elastic sheet 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, elastic sheet 30, and 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 applying pressure between the two layers, heating is performed by ultrasonic vibration energy from the ultrasonic horn 61 to melt only the elastic sheet 30 or to melt at least one of the first sheet layer 20A and the second sheet layer 20B and the elastic sheet 30. By doing so, the first sheet layer 20A and the second sheet layer 20B are bonded through the bonding holes 31 at the same time as forming the bonding holes 31 in the elastic sheet 30. Therefore, in this case, the area ratio of the sheet joining portion 40 can be selected by selecting the size, shape, spacing, arrangement pattern in the roll length direction and roll circumferential direction, etc. of the projections 60a of the anvil roll 60. Can be done.

Although the reason why the joining holes 31 are formed is not necessarily clear, it is thought that the holes are formed when a portion of the elastic sheet 30 corresponding to the protrusion 60a of the anvil roll 60 melts and separates from the surroundings. At this time, the portions of the elastic sheet 30 between adjacent joining holes 31 lined up in the stretching direction ED are as shown in FIGS. In this case, the bonding hole 31 cuts the parts on both sides in the expansion and contraction direction, and the support on both sides in the contraction direction is lost. The center side contracts until it is balanced with the center side in the expansion/contraction direction, and the joining 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 nonwoven fabric in which at least a portion of the fibers can be welded (that is, it contains a thermoplastic resin component). For example, synthetic fibers such as olefin-based fibers such as polyethylene and polypropylene, polyester-based fibers, and polyamide-based fibers, mixed fibers containing two or more of these components, or composite fibers containing two or more of these components (e.g., fibers with a sheath component that is molten) An example is a core-sheath type that is easy to clean. Furthermore, the nonwoven fabric may be manufactured by any processing.

The basis weight of the nonwoven fabric used for the first sheet layer 20A and the second sheet layer 20B is preferably about 10 to 25 g/m ² . Moreover, a part or all of the first sheet layer 20A and the second sheet layer 20B may be a pair of layers formed by folding back a single sheet of material and facing each other. For example, as shown in the figure, in the waist portion 23, the outer component is the second sheet layer 20B, and the folded part 20C, which is folded back toward the inner side at the waist opening edge, is the first sheet layer 20A. An elastic sheet 30 is interposed between them, and in other parts, the inner component is the first sheet layer 20A, the outer component is the second sheet layer 20B, and the elastic sheet 30 is interposed between them. can be done. Of course, the constituent materials of the first sheet layer 20A and the constituent materials of the second sheet layer 20B are separately provided over the entire front and rear direction LD, and the constituent materials of the first sheet layer 20A and the second sheet An elastic sheet 30 can also be interposed between the constituent materials of layer 20B.

The elastic sheet 30 is not particularly limited, and may be an elastic film or a stretchable nonwoven fabric as long as it is made of thermoplastic resin and has elasticity. Moreover, as the elastic sheet 30, in addition to a non-porous one, one in which many holes or 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, CD perpendicular to the stretching direction) is 5 to 20 N/35 mm, and the tensile strength in the width direction is 5 to 20 N/35 mm. It is preferable that the elastic sheet 30 has a tensile elongation in the WD of 450 to 1050% and a tensile elongation in the longitudinal direction LD of 450 to 1400%. The thickness of the elastic sheet 30 is not particularly limited, but is preferably about 20 to 40 μm.

(stretch area)
In the region of the exterior body 20 having the elastic sheet stretchable structure 20X, the waist portion 23 and the waist adjacent portion 22 are contracted in the width direction due to the contraction of the elastic sheet 30 and are expandable in the width direction (that is, in the stretch direction ED). is the width direction WD of the diaper). The elastic region 80 is contracted in the width direction WD due to the contraction force of the elastic sheet 30, and can be expanded in the width direction WD. More specifically, with the elastic sheet 30 stretched in the width direction WD, the first sheet is inserted through the joining holes 31 of the elastic sheet 30 at intervals in the width direction WD and the orthogonal direction XD perpendicular thereto. By joining the layer 20A and the second sheet layer 20B to form a large number of sheet joints 40, the elastic sheet stretchable structure 20X is formed, and the elastic sheet 30 remains unbroken in the width direction WD in the stretchable region 80. , and by arranging the sheet joining portion 40 so that the first sheet layer 20A and the second sheet layer 20B contract due to the contraction force of the elastic sheet 30 to form contraction folds 25, such elasticity can be achieved. can be granted.

In the elastic region 80 in the waist adjacent portion 22, the elastic sheet 30 (that is, the portion without the joining hole 31) is a non-porous band that continues linearly along the width direction WD, as shown in the example shown in FIGS. 7 and 9. 32 or not as in the example shown in FIG. 11 and the example shown in FIG.

In the stretchable region 80, in the natural length state, the first sheet layer 20A and the second sheet layer 20B between the sheet joint portions 40 are Contraction folds 25 are formed that swell in directions that separate from each other and extend in the orthogonal direction XD, and even in the installed state where they are stretched to some extent in the width direction WD, the contraction folds 25 remain although they are stretched. Further, as shown in the illustrated embodiment, the first sheet layer 20A and the second sheet layer 20B are not joined to the elastic sheet 30 at least at a portion other than between the first sheet layer 20A and the second sheet layer 20B at the sheet joint portion 40. , FIGS. 7(c) and 9(c) assuming the attached state, and FIGS. 7(a), (b), and 9(a) assuming the unfolded state of the first sheet layer 20A and the second sheet layer 20B. ) As can be seen from (b), in these conditions, a gap is formed between the joining hole 31 in the elastic sheet 30 and the sheet joining part 40, and the material of the elastic sheet 30 is a non-porous film or sheet. Even if there is, this gap adds breathability. In particular, when the elastic sheet 30 has a non-porous band 32 that continues linearly along the width direction WD, in the natural length state, the joining hole 31 narrows due to further contraction of the elastic sheet 30. If the configuration is such that almost no gap is formed between the joining hole 31 and the sheet joining portion 40 and the elastic sheet 30 does not have a linearly continuous portion along the width direction WD, the joining hole 31 and the sheet joining portion 40 A gap remains between the joint portion 40 and the joint portion 40 .

It is desirable that the maximum elongation of the stretchable region 80 in the width direction WD is 190% or more (preferably 200 to 220%). The maximum elongation of the elastic region 80 is approximately determined by the elongation rate of the elastic sheet 30 during manufacture, but based on this, it is reduced by factors that inhibit contraction in the width direction WD. The main inhibiting factor is the ratio of the length L of the sheet joint portion 40 per unit length in the width direction WD, and the larger this ratio is, the lower the maximum elongation is. In normal cases, the length L of the sheet joint 40 has a correlation with the area ratio of the sheet joint 40, so the maximum elongation of the elastic region 80 can be adjusted by the area ratio of the sheet joint 40.

In the case where the elastic sheet 30 has a non-porous band 32 linearly continuous along the width direction WD, as in the examples shown in FIGS. 7 and 9, the elongation stress in the elastic region 80 is mainly The elastic sheet 30 is determined by the sum of the orthogonal dimensions 32w (equal to the bonding hole spacing 31d) of the non-porous band 32 (see FIGS. 7(a) and 9(a)) that continues linearly along the width direction WD. Can be adjusted. On the other hand, as in the example shown in FIG. 11 and the example shown in FIG. It can be adjusted by the intersection angle between the direction and the expansion/contraction direction ED, and normally, in the unfolded state, the acute intersection angles θ1 and θ2 between the continuous direction of the unjointed bands 51 and 52 and the expansion/contraction direction ED are each larger than 0 degrees. The temperature is preferably 45 degrees or less, particularly in the range of 10 to 30 degrees.

The area ratio of the sheet joint portions 40 in the elastic region 80 and the area of each sheet joint portion 40 can be determined as appropriate, but in normal cases, it is preferably within the following range.
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, the maximum elongation and elongation stress of the elastic region 80 can be adjusted by the area of the sheet joint 40, so as shown in FIGS. The fit can be changed depending on the area. In the form shown in FIGS. 1 and 2, the edge region 82 of the leg opening has a higher area ratio of the sheet joint portion 40 than other regions, and therefore has a weaker extensional stress and is a region that flexibly expands and contracts. There is.

The shape of each sheet joining portion 40 and joining hole 31 in their 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 diamond, a convex lens shape, a concave lens shape, or a star. It can be of 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 orthogonal dimension 31y of the joining hole 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 perpendicular to the direction of expansion and contraction.

The size of each sheet joint 40 may be determined as appropriate; however, if it is too large, the hardness of the sheet joint 40 will have a large effect on the feel, and if it is too small, the joint area will be small and the materials will not adhere well to each other. Therefore, in the normal case, it is preferable that the area of each sheet joining portion 40 is approximately 0.14 to 3.5 mm ² . Since the sheet joint is formed through the joint hole 31, the area of the opening of each joint hole 31 may be larger than the sheet joint, but it should be about 1 to 1.5 times the area of the sheet joint. It is preferable. Note that the area of the opening of the bonding hole 31 means the value in the state of the elastic film 30 not in the state of being alone but in the state of being integrated with the first sheet layer 20A and the second sheet layer 20B and in the state of natural length. This means the minimum value when the area of the opening 31 is not uniform in the thickness direction, such as when the area of the opening is different between the front and back sides of the elastic film 30.

Although the planar arrangement of the sheet joint portions 40 and the joining holes 31 in the waist adjacent portion 22 can be determined as appropriate, a regularly repeated planar arrangement is preferable, such as an orthorhombic lattice shape as shown in FIG. 10(b), a square lattice as shown in FIG. 10(c), a rectangular lattice as shown in FIG. 10(d), and a rectangular lattice as shown in FIG. 10(e). ), such as a parallel body lattice (as shown in the figure, two groups of parallel diagonal rows are provided so as to intersect with each other), etc. In addition to those that are regularly repeated (including those that are inclined at an angle), groups of sheet joints 40 (the arrangement of the group unit may be regular or irregular, and may be in the shape of a pattern or letter) are regular. It can also be repeated.

The arrangement pattern of the sheet joining portions 40 in the waist adjacent portion 22 is preferably as shown in the example shown in FIG. 9, the example shown in FIG. 11, and the example shown in FIG. 15. That is, in these examples, the stretchable region 80 has an acute angle (acute side crossing angle θ1) with respect to the stretchable direction ED as non-joint bands 51 and 52 in which parts without the sheet joint portion 40 are continuous in the unfolded state. The first unjointed zones 51 that are linearly continuous along the first direction 51d that intersects with the first direction 51d are repeatedly present at intervals in the direction perpendicular to the first direction 51d. Furthermore, a large number of sheet joint portions 40 and joint holes 31 are provided at intervals between adjacent first non-joint bands 51 in the elastic region 80 . Characteristically, a unit structure including a plurality of first unjointed bands 51 having different first widths 51w determined as widths in a direction perpendicular to the first direction 51d is perpendicular to the first direction 51d in the elastic region 80. exist repeatedly in the direction.

In this way, when unit structures including a plurality of first unjointed bands 51 having different first widths 51w are repeatedly present in the direction orthogonal to the first direction 51d in the elastic region 80, the inside of the first unjointed bands 51 A similar width change in size is also formed in the continuous portion of the elastic sheet 30. In other words, if the width 51w of the first non-bonded band 51 is narrow, the width of the continuous portion of the internal elastic sheet 30 will also be narrow, and if the width 51w of the first non-bonded band 51 is wide, the continuous part of the internal elastic sheet 30 will be narrow. The width of the section also becomes wider. If there is a change in the first width 51w in the continuous portion of the elastic sheet 30 in the first non-bonded band 51, the continuous portion of the elastic sheet 30 in the wide first non-bonded band 51 and the narrow continuous portion 1. As a result of visually emphasizing both continuous parts of the elastic sheet 30 within the unjointed band 51, even if the stretchable region 80 is in its natural length state (see FIGS. 13 and 17), it can be stretched to a certain extent in the attached state. Even if there is, it will have a beautiful diagonal striped appearance. In addition, in a state of shrinkage to a certain extent, the size of the shrinkage folds 25 in the first non-bonded band 51 changes according to the first width 51w of the first non-bonded band 51, so the effect of the shrinkage folds 25 causes diagonal stripes. The pattern will appear more clearly.

The unit structure described above is not limited by the magnitude of the width 51w as long as it includes a plurality of first non-joint bands 51 having different first widths 51w. The width 51w is preferably 1.2 to 60 times as large as the first non-bonded band 51 having the nearest width 51w, and 0.01 to 0.8 times as small.

Further, as long as the unit structure described above includes a plurality of first non-joint bands 51 having different first widths 51w, the first widths 51w of all the first non-joint bands 51 may be different, and the first widths 51w may be different from each other as shown in the figure. The first width 51w of some of the plurality of first non-joint bands 51 may be different from the first width 51w of the other one or more first non-joint bands 51.

Even if a diagonal striped pattern along the first direction 51d due to the contraction folds 25 of the first unjointed band 51 and the continuous portion of the elastic sheet 30 inside appears in the elastic region 80, other If the diagonal striped pattern along the diagonal direction becomes more visible, the diagonal striped pattern caused by the contraction folds 25 of the first unjointed band 51 and the continuous portion of the elastic sheet 30 inside thereof may become less noticeable. On the other hand, the maximum value of the first width 51w in the first unjointed band 51 is the maximum value of the width in the direction orthogonal to the continuous direction in all the unjointed bands 51, 52 having different and common inclination directions. This is preferable because the diagonal striped pattern formed by the contraction folds 25 of the first unjointed band 51 and the continuous portion of the elastic sheet 30 inside the contraction folds 25 in the stretchable region 80 becomes more clearly visible. In this case, the maximum value of the first width 51w of the first non-joint band 51 can be determined as appropriate, but it is preferably 0.01 to 9 times the width of the first non-joint band 51 having the nearest width 51w. preferable. Note that the width of all the non-bonded bands 51 and 52 including the first non-bonded band 51 in the direction perpendicular to the continuous direction is not limited, but is usually within the range of 0.3 to 50 mm. It is preferable. Needless to say, the width in the direction orthogonal to the continuous direction of the non-joint bands 51 and 52 is the first width 51w of the first non-joint band 51, which is a linearly continuous portion. Therefore, the width is equal.

The first interval 51s, which is defined as the interval between adjacent first unjointed bands 51 in a direction perpendicular to the first direction 51d, can be determined as appropriate. Therefore, the first interval 51s may be the same as, wider, or narrower than the first width 51w of the adjacent first non-joint bands 51. One preferable example is a unit structure in which the maximum value of the first width 51w in the first non-bonded zone 51 is smaller than the maximum value of the first interval 51s. In this way, by forming the widely spaced parts in the unit structure, the diagonal striped pattern caused by the contraction folds 25 of the first unjointed band 51 and the continuous part of the elastic sheet 30 inside thereof becomes more clearly visible. . In this case, the maximum value of the first width 51w in the first non-joint zone 51 can be determined as appropriate, but it is preferably 0.01 to 9 times the maximum value of the first interval 51s. Note that the interval in the direction perpendicular to the continuous direction in all the non-bonded bands 51 and 52 including the first non-bonded band 51 is not particularly limited, but is usually within the range of 0.3 to 50 mm. It is preferable. Needless to say, the interval in the direction perpendicular to the continuous direction in the non-joint bands 51 and 52 is the first interval 51s in the first non-joint band 51, and is equal to the continuous direction. .

The non-bonded bands 51 and 52 include a second non-bonded band 52 that continues linearly along a second direction 52d that intersects at an acute angle (acute angle side crossing angle θ2) with respect to the expansion/contraction direction ED, other than the first direction 51d. may exist repeatedly at intervals in the direction orthogonal to the second direction 52d, or the second non-bonded zone 52 may not exist. One preferable form having the second non-bonded zone 52 is that the non-bonded zones 51 and 52 are formed in a diagonal lattice shape in the elastic region 80, and the first non-bonded zone 51 is formed in a diagonal lattice shape. The second unjointed belt 52 is a part of the bands 51 and 52 that continues in one direction, and the second unjointed belt 52 is a part that continues in the other direction of the oblique lattice-shaped unjointed bands 51 and 52. In this case, the first direction 51d and the second direction 52d have opposite polarities with respect to the expansion/contraction direction ED. Note that even if the form does not have the unjointed 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 acute cross angles θ1 and θ2 of the first direction 51d and the second direction 52d with respect to the stretching direction ED are respectively 5 to 45 degrees, particularly 10 to 30 degrees, thereby ensuring sufficient stretchability in the stretchable region 80. Can be done.

However, if the diagonal striped pattern along the diagonal direction of the second non-bonded band 52 is more strongly visible in the same elastic region 80, the contraction fold 25 of the first non-bonded band 51 and the continuous part of the elastic sheet 30 inside it The diagonal striped pattern may become less noticeable. Therefore, when the second non-joint band 52 is provided as in the example shown in FIG. , it is desirable to arrange the sheet joint portion 40 so as not to have the second non-joint zone 52. As a result, the diagonal striped pattern formed by the contraction folds 25 of the first unjointed band 51 and the continuous portion of the elastic sheet 30 inside the contraction folds 25 becomes more clearly visible within the stretchable region 80 .

On the other hand, the sheet joints 40 are aligned in the first direction 51d between the adjacent first non-joint bands 51, but in this case, as shown in FIG. 16, all the sheet joints 40 are If the acute angle side intersection angle θ3 of the longitudinal direction with respect to the direction perpendicular to the direction ED is within 10 degrees, and the maximum dimension 40e in the expansion/contraction direction ED is 0.1 to 0.4 mm, the first unjointed zone is formed. This is preferable because it is possible to ensure a larger dimension in the stretching direction ED of 51 and to suppress a decrease in stretchability.

Further, as in the example shown in FIG. 11, the unit structure includes a wide first unjointed band 51 having a maximum first width 51w, and a narrow first unjointed band 51 having a narrower first width 51w. , in the case where a plurality of strips are included adjacent to each other in a direction orthogonal to the first direction 51d, between the adjacent wide first non-jointed bands 51, the acute angle side intersection angle in the longitudinal direction with respect to the second direction 52d is within 5 degrees, It is preferable that the sheet joining parts 40, which are elongated and have a maximum dimension 40f of 0.1 to 0.4 mm in the direction orthogonal to the longitudinal direction, are arranged at intervals in the first direction 51d. Moreover, between the adjacent narrow width first unjointed bands 51, the acute angle side intersection 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 the sheet joining portions 40, each having a slender shape of 1 to 0.4 mm, are arranged at intervals in the first direction 51d. With such a shape and arrangement of the sheet joint portion 40, the shrinkage folds 25 of the first non-joint band 51 and the continuous portion of the elastic sheet 30 therein can be particularly visually emphasized with a smaller area of the sheet joint portion 40. Become so.

The row of sheet joint portions 40 located between adjacent non-joint bands 51 and 52 (the row in the continuous direction of non-joint bands 51 and 52) may be one row or multiple rows. Furthermore, although it is preferable that the intervals between the sheet joining parts 40 in the row direction be regular, all the intervals do not need to be constant, and some intervals may be different.

(Regarding the differences in the elastic areas of the waist and adjacent waist areas)
FIG. 19 shows an example of the arrangement of the joining holes 31 and the sheet joining portions 40 that can tighten the waist portion 23 more strongly. In this example, the elastic region 80 of the waist portion 23 includes a non-porous band 32 in which a portion without joining holes 31 is continuous along the width direction WD in the unfolded state, and a sheet joint portion 40 that is spaced apart in the width direction WD. The joining bands 53 arranged at intervals are alternately and repeatedly provided in the orthogonal direction XD orthogonal to the width direction WD. Further, in the elastic region 80 of the waist adjacent portion 22, there is at least one non-porous band 32 (in the illustrated example, the non-porous band 32 is continuous along the width direction WD) in the expanded state. , and joint bands 53 in which the sheet joint parts 40 are arranged at intervals in the width direction WD are provided alternately and repeatedly in the orthogonal direction XD. is longer than the dimension of the non-porous band 32 of the waist adjacent portion 22 in the orthogonal direction XD. Even if part or all of the elastic region 80 of the waist adjacent portion 22 has the above-described structure (the example shown in FIG. 9, the example shown in FIG. 11, and the example shown in FIG. 15) without the imperforate band 32, good.

As mentioned above, in the present elastic structure 20X, the tightening force is almost determined by the elongation stress and the contact area of the elastic sheet 30, and the strength of the elongation stress of the elastic sheet 30 is basically determined by the cross-sectional area of the elastic sheet 30 (with constant thickness). If so, it is determined by the dimension in the orthogonal direction XD perpendicular to the width direction WD). Furthermore, in the present stretchable structure 20X, the continuity of the elastic sheet 30 is lost in the portion having the sheet joint portion 40. Therefore, in the present stretchable structure 20X, the cross-sectional area of the elastic sheet 30 that contributes to the stretching stress is basically determined by the dimension of the non-porous band 32 in the orthogonal direction XD. Here, in the present elastic structure, the dimension in the orthogonal direction XD of the plurality of imperforate bands 32 in the waist portion 23 is longer than the dimension in the orthogonal direction XD of the imperforate bands 32 in the waist adjacent portion 22, or the waist adjacent portion 22 is not provided with a non-porous band 32. Therefore, although the disposable wearing article of this embodiment is stretchable by the same elastic sheet 30 covering the waist portion 23 and the waist adjacent portion 22, the thickness of the waist portion 23 is not increased, that is, the waist portion 23 is expanded and contracted as shown in the illustrated example. Even if the elastic sheet 30 is a single layer (not a plurality of layers due to folding or the like), the waist portion 23 can be tightened more strongly.

The dimensions of the imperforate band 32 in the waist portion 23 and the waist adjacent portion 22 in the orthogonal direction XD may be determined as appropriate. As an example, when the elastic sheet 30 is an elastic film with a thickness of 20 to 40 μm, the dimension of the plurality of non-porous bands 32 in the waist portion 23 in the orthogonal direction XD is 2 to 5 mm, and The dimension in the orthogonal direction XD of 32 is 0.25 times or less the dimension in the orthogonal direction It is preferable if it is not.

The number of imperforate bands 32 of the waist part 23 is naturally determined by the dimension of the imperforate band 32 in the orthogonal direction XD, which is determined according to the tightening force, and the dimension of the waist part 23 in the orthogonal direction XD. In this case, it is preferable that the number is about 3 to 7.

As long as the dimension in the orthogonal direction XD of the plurality of imperforate bands 32 in the waist part 23 is longer than the dimension in the orthogonal direction XD of the imperforate bands 32 in the waist adjacent part 22, the waist part The dimension in the orthogonal direction XD of one (or more than one, but preferably less than the majority) imperforate band 32 in 23 is larger than the dimension in the orthogonal direction XD of the imperforate band 32 in the waist adjacent part 22. It can be short. In this case, the imperforate band 32 of the waist portion 23 that is shorter than the dimension in the orthogonal direction XD of the imperforate band 32 of the waist adjacent portion 22 is only located at the end of the waist portion 23 on the waist opening side. is desirable, but it may be located in the middle of the waist portion 23 in the orthogonal direction XD.

The shape of the joining hole 31 in the waist portion 23 is not particularly limited. The joining holes 31 in the waist portion 23 may be all the same as in the example shown in FIG. 19, or may be different as in the example shown in FIG. It is preferable that the natural length state of the joining hole 31 in the waist portion 23 is elongated in the width direction WD, as shown in the examples shown in FIGS. It is more preferable that the joint hole 31 has a linear shape, since the shorter the dimension of the joining hole 31 in the orthogonal direction XD, the stronger the tightening force of the waist portion 23 can be, when comparing the usage area of the same elastic sheet 30. Further, in this case, the area of the sheet joining portion 40 can be reduced while joining the first sheet layer 20A and the second sheet layer 20B over a wide range, resulting in excellent flexibility and air permeability. Although FIGS. 20 to 22 show the expanded state, in the natural length state, the shape of the bonding hole 31 is a rectangle with the long side along the width direction WD. The shape of the joining hole 31 in the natural length state may be a long hole shape with arcuate ends at both ends in the width direction WD, or a rectangular shape with rounded corners. Although the dimensions of the joining hole 31 in the joining band 53 of the waist portion 23 can be determined as appropriate, it is usually preferable that the dimension in the orthogonal direction XD is 0.1 to 1.1 mm. Note that, as described above, if the non-perforated belt 32 is adjacent to both sides of the joining band 53 in the orthogonal direction be. The shapes of the joining holes 31 in the waist portion 23 and the joining holes 31 in the waist adjacent portion 22 may be the same as in the example shown in FIG. 19, or may be different as in the example shown in FIG. 22.

Furthermore, if the joining hole 31 in the joining band 53 of the waist portion 23 is too large or too close to the stretching direction ED, there is a risk that the elastic sheet 30 will partially break. is 3 to 6 mm, and the interval in the expansion/contraction direction ED is preferably 3 to 8 mm. Note that the arrangement and dimensions of the joint portion of the waist adjacent portion 22 and the joint hole 31 can be determined as appropriate within the above-mentioned range.

Regarding some or all of the plurality of imperforate bands 32 in the waist portion 23, the dimensions in the orthogonal direction XD may be the same or different. For example, as in the example shown in FIG. 21, if the dimension in the orthogonal direction Since the adhesiveness of the waist portion 23 is increased, it is suitable when the adhesiveness of the waist portion 23 is important. As an example, the dimension of the non-porous band 32 in the orthogonal direction XD can be such that the longest dimension is about 1.5 to 2.5 times the shortest dimension.

Further, as in the example shown in FIG. 22, the dimension in the orthogonal direction XD of the imperforate band 32 of the waist portion 23 may become shorter as it approaches the edge of the waist opening. In this case, since the tightening force becomes weaker closer to the edge of the waist portion 23, the user can easily insert his or her fingers between the waist portion 23 and the skin to grasp the disposable wearing article in the worn state. Therefore, for example, in the case of a pants-type disposable diaper, the waist portion 23 can be easily grasped in the worn state, and the work of putting up and lowering the pants-type disposable diaper becomes easy. As an example, the dimension of the non-porous band 32 in the orthogonal direction XD can be such that the longest dimension is about 1.5 to 2.5 times the shortest dimension.

As shown in FIG. 23, the dimension of the non-porous band 32 of the waist portion 23 in the orthogonal direction range) may become longer as it approaches the edge of the waist opening, and may become shorter as it approaches the edge of the waist opening at the outer side 20S in the width direction WD. In this case, the dimension of the non-porous band 32 of the waist portion 23 in the orthogonal direction XD changes depending on the position in the width direction WD. Here, in this embodiment, although the area of the elastic sheet 30 is large in the portion where the non-porous band 32 has a long dimension in the orthogonal direction XD, at least one of its width directions WD has a short dimension in the orthogonal direction As a result, it becomes weaker. As a result, in this embodiment, the tightening force is stronger in the portion that tightens the abdomen as it gets closer to the edge of the waist portion 23, and in the portion that contacts the ilium, the tightening force is weaker as it gets farther from the edge of the waist portion 23. The fit of No. 23 becomes even better. As an example, the dimension of the non-porous band 32 in the orthogonal direction XD can be such that the longest dimension is about 1.5 to 2.5 times the shortest dimension.

On the other hand, in the example shown in FIG. 24, the stretchable region 80 of the waist portion 23 includes a non-porous band 32 in which the portion without the joining hole 31 is continuous along the width direction WD and the sheet joining portion 40 in the unfolded state. Bonding bands 53 arranged at intervals in the width direction WD are alternately and repeatedly provided in the orthogonal direction XD orthogonal to the width direction WD. Further, in each imperforate band 32 in the elastic region 80 of the waist portion 23, an elastic band 33 in which the elastic sheet 30 is divided in the orthogonal direction XD is arranged. Such division of the elastic band 33 is achieved by closely arranging the sheet joints 40 along the division positions in the elastic sheet 30 and breaking all the parts between the joint holes 31 formed together with the sheet joints 40. It can be carried out. Furthermore, in the stretchable region 80 of the waist adjacent portion 22, there is at least one non-porous band 32 (in the illustrated example, the non-porous band 32 is continuous along the width direction WD in the portion without the joining hole 31) in the expanded state. , the sheet joint portions 40 are provided with joint bands 53 arranged at intervals in the width direction WD, alternately and repeatedly in the orthogonal direction XD, and the dimensions of the plurality of elastic bands in the waist portion 23 in the orthogonal direction XD. is wider than the dimension of the non-porous band 32 of the waist adjacent portion 22 in the orthogonal direction XD. Part or all of the elastic region 80 of the waist adjacent portion 22 may have the above-described structure (the example shown in FIG. 9, the example shown in FIG. 11, and the example shown in FIG. 15) without the imperforate band 32. .

In this example, the elastic band 33 of the waist portion 23 is formed by dividing the elastic sheet 30, and the dimension of the plurality of elastic bands 33 in the waist portion 23 in the orthogonal direction is longer than the dimension in the orthogonal direction XD, or the non-porous band 32 is not provided in the waist adjacent portion 22. Therefore, although the single elastic sheet 30 imparts elasticity to the waist portion 23 and the waist adjacent portion 22, the thickness of the waist portion 23 does not increase. ), the waist portion 23 can be tightened more strongly. Furthermore, since the elastic sheet 30 is not continuous from the waist part 23 to the waist adjacent part 22, and the elastic band 33 in which the elastic sheet 30 is divided is provided in the elastic region 80 of the waist part 23, the appearance of the waist part 23 is different from that of the waist part 22. Unlike the appearance of the adjacent portion 22, it is possible to make the appearance of the waist portion 23 stand out.

The dimensions of the elastic band 33 of the waist portion 23 and the imperforate band 32 of the waist adjacent portion 22 in the orthogonal direction XD may be determined as appropriate. As an example, when the elastic sheet 30 is an elastic film with a thickness of 20 to 40 μm, the dimension of the plurality of elastic bands 33 in the waist portion 23 in the orthogonal direction XD is 2 to 5 mm, and the non-porous band 3 The dimension in the orthogonal direction XD is 0.25 times or less the dimension in the orthogonal direction and preferable.

As long as the dimension in the orthogonal direction XD of the plurality of elastic bands 33 in the waist part 23 is longer than the dimension in the orthogonal direction , preferably less than a majority) may be shorter than the dimension of the elastic band 33 in the waist adjacent portion 22 in the orthogonal direction XD. In this case, it is desirable that the elastic band 33 of the waist part 23 that is shorter than the dimension in the orthogonal direction XD of the elastic band 33 of the waist adjacent part 22 is located only at the end of the waist part 23 on the waist opening side. may be located in the middle of the waist portion 23 in the orthogonal direction XD.

The number of elastic bands 33 in the waist part 23 is naturally determined by the dimension of the elastic bands 33 in the orthogonal direction XD, which is determined according to the tightening force, and the dimension of the waist part 23 in the orthogonal direction XD. It is preferable that the number is about 7 to 7.

The dimensions and arrangement of the sheet joint portion 40 may be determined as appropriate as long as the elastic sheet 30 can be separated, but normally, the size of the sheet joint portion 40 in the expansion/contraction direction ED is 0.5 to 3.0 mm; The spacing in the stretching direction ED is preferably 2 to 5 mm.

Other matters in the example shown in FIG. 24 are the same as in the example shown in FIG. 19 and the like described above.

(Non-stretchable area)
In the region of the exterior body 20 having the elastic sheet stretchable structure 20X, a non-stretchable region 70 can be provided at least on one side in the width direction of the stretchable region 80, as shown in FIG. The non-stretchable region 70 means that the maximum elongation in the stretching direction is 120% or less. The maximum elongation of the non-stretchable region 70 is preferably 110% or less, 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 outer body 20 of the pants-type disposable diaper as in this example, the portion overlapping with the absorbent core 13 is an area that does not require expansion and contraction. It is preferable that the non-stretchable region 70 includes almost the entire inner and outer fixed regions 10B. That is, the stretchable region 80 of the waist portion 23 is continuous over the entire widthwise WD of the waist portion 23 (excluding the side seal portions 21), but a portion of the waist adjacent portion 22 is the non-stretchable region 70. Of course, the non-stretchable region 70 can be provided from the region that overlaps with the absorbent core 13 to the region that does not overlap with the absorbent core 13 located in the width direction WD or front-rear direction LD, and the non-stretchable region is provided only in the region that does not overlap with the absorbent core 13. 70 may also be provided.

The shape of each sheet joining portion 40 in the non-stretchable region 70 is not particularly limited, and can be appropriately selected from the shapes described above.

In addition, the area ratio of the sheet joints 40 in the non-stretchable region 70 and the area of each sheet joint 40 can be determined as appropriate, but in normal cases, if it is within the following range, the area of each sheet joint 40 is It is preferable that the non-stretchable region 70 becomes hard because it is small and the area ratio of the sheet joint portion 40 is low.
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%)

The non-stretchable region 70 can be formed by, for example, arranging the sheet joining portions 40 closely so that the first sheet layer and the second sheet layer do not contract due to the contraction force of the elastic sheet 30 and creases are not formed. Specific examples of methods for forming the non-stretchable region 70 include those shown in Japanese Patent No. 5980355, Japanese Patent No. 5918877, Japanese Patent No. 5980367, and Japanese Patent No. 6049228.

<Explanation of terms in the specification>
The following terms in the specification have the following meanings unless otherwise specified in the specification.
- "Front body" and "back body" refer to the front and rear parts of the pants-type disposable diaper, respectively, with the front-rear center as the border. In addition, the crotch area refers to the range in the front-rear direction including the center in the front-rear direction of the pants-type disposable diaper, and in the case where the absorbent body has a constriction part, it means the range in the front-rear direction of the part having the constriction part.
・"Maximum elongation" means the maximum elongation in the stretching direction ED (in other words, the elongation in the unfolded state where the first sheet layer and the second sheet layer are flattened without shrinkage or slack), and The length is expressed as a percentage when the natural length is 100%.
・"Area ratio" means the ratio of the target part to the unit area, and the target part (for example, the sheet joint 40, the opening of the joint hole 31, the ventilation hole) in the target area (for example, the stretchable region 80, the non-stretchable region 70) ) is divided by the area of the target region and expressed as a percentage. In particular, the "area ratio" in a region having a stretchable structure means the area ratio in the expanded state. In a configuration in which a large number of target parts are provided at intervals, it is desirable to set the target area to a size that includes 10 or more target parts and calculate the area ratio.
- "Elongation rate" means a value when the natural length is 100%.
・“Basic weight” 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 reach a constant weight. Pre-drying refers to making the sample or test piece constant weight in an environment at a temperature of 100°C. Note that fibers with an official moisture content of 0.0% do not need to be pre-dried. From the test piece that has reached a constant weight, use a sample sampling template (100 mm x 100 mm) to cut out a sample with dimensions of 100 mm x 100 mm. Measure the weight of the sample, multiply by 100 to calculate the weight per square meter, and use it as the basis weight.
・The "thickness" of the absorber can be measured using a thickness measuring device manufactured by Ozaki Seisakusho Co., Ltd. (Peacock, dial thickness gauge large type, model J-B (measuring range 0 to 35 mm) or model K-4 (measuring range 0 to 50 mm)) Measure with the sample and thickness measuring device horizontal.
- "Thickness" other than the above is automatically measured using an automatic thickness measuring device (KES-G5 Handy Compression Measurement Program) under the conditions of load: 0.098 N/cm ² and pressurized area: 2 cm ² .
・“Tensile strength” and “Tensile elongation (elongation at break)” were determined according to JIS K7127:1999 “Plastics - Test method for tensile properties”, except that the test piece was rectangular 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 the tensile tester, for example, AUTOGRAPH AGS-G100N manufactured by SHIMADZU can be used.
・"Elongation stress" is determined by a tensile test with an initial chuck interval (distance between gauge lines) of 50 mm and a tensile speed of 300 mm/min in accordance with JIS K7127:1999 "Plastics - Test method for tensile properties." , means the tensile stress (N/35 mm) measured when elongating within the elastic region, and the degree of elongation can be determined as appropriate depending on the test object. It is preferable that the test piece has a rectangular shape with a width of 35 mm and a length of 80 mm or more, but if it is not possible to cut out a test piece with a width of 35 mm, create a test piece with the width that can be cut out, and measure the measured value with a width of 35 mm. The value is converted to Furthermore, even if the target area is small and it is not possible to collect enough test pieces, if the magnitude of the elongation stress is to be compared, it is possible to at least make comparisons using suitably small test pieces or test pieces of the same size. . As the tensile tester, for example, AUTOGRAPH AGS-G100N manufactured by SHIMADZU can be used.
- "Unfolded state" means a state in which it is flattened without shrinkage or slack.
- Unless otherwise specified, the dimensions of each part refer to the dimensions in the unfolded state, not in the natural length state.
- If there is no description of the environmental conditions for the test or measurement, the test or measurement shall be conducted in a test room or equipment under standard conditions (test location: temperature 23 ± 1°C, relative humidity 50 ± 2%). do.

As long as the present invention is equipped with an elastic member that can be elastically expanded and contracted by an elastic sheet, the present invention is applicable to disposable wearing articles such as pants-type disposable diapers as mentioned above, tape-type disposable diapers, disposable wearing articles for swimming and playing in the water, etc. It can be used universally.

DESCRIPTION OF SYMBOLS 10...Inner body, 10B...Internal and external fixed areas, 11...Top sheet, 12...Liquid-impermeable sheet, 13...Absorbent body, 13N...Narrowed portion, 14...Wrapping sheet, 17...Non-absorbent body side part, 20...Exterior body , 20A...First sheet layer, 20B...Second sheet layer, 20C...Folded portion, 20X...Elastic sheet stretchable structure, 21...Side seal portion, 22...Waist adjacent portion, 23...Waist portion, 25...Shrinkage folds, 30 ... Elastic sheet, 31... Joining hole, 32... Non-porous band, 33... Elastic band, 40... Sheet joint portion, 51, 52... Non-joining band, 51... First non-joining band, 51d... First direction, 51s... First interval, 51w...first width, 52...second unjointed band, 52d...second direction, 53...joint band, 70...non-stretchable region, 80...stretchable region, 90...three-dimensional gather, 93...lodging portion, 94...Free portion, 95...Gathered sheet, 96...Gathered elastic member, B...Back body, ED...Stretching direction, F...Front body, L...Intermediate part, T...Waist circumference, LD...Anteroposterior direction, WD...Width Direction, XD...Orthogonal direction.

Claims (4)

A disposable wearing article comprising an elastic member having a waist portion and a waist adjacent portion adjacent to the waist portion,
The waist part and the waist adjacent part of the elastic member have a first sheet layer, a second sheet layer, and an elastic sheet interposed between them,
The elastic sheet is continuous from the waist portion to a portion adjacent to the waist,
The first sheet layer and the second sheet layer are welded through a joining hole penetrating the elastic sheet at spaced apart sheet joining parts,
The waist portion and the waist adjacent portion of the elastic member have an elastic region that is contracted in the width direction due to contraction of the elastic sheet and can be expanded in the width direction,
In the elastic region of the waist portion, in the unfolded state, a non-porous band in which the portion without joining holes is continuous along the width direction, and a joining band in which the sheet joining portions are arranged at intervals in the width direction. are provided alternately and repeatedly in the orthogonal direction perpendicular to the width direction,
The elastic region adjacent to the waist is provided with a non-porous band in which the portion without the joining hole is continuous along the width direction in the unfolded state, and the non-porous band of the plurality of non-porous bands in the waist portion the dimension in the orthogonal direction is longer than the dimension in the orthogonal direction of the imperforate band of the portion adjacent to the waist, or the imperforate band is not provided in the elastic region of the portion adjacent to the waist;
The dimension in the orthogonal direction of the imperforate band of the waist part is such that in the central range of 1/4 to 1/2 of the total width of the waist part, it becomes longer as it approaches the edge of the waist opening, and on both sides of this central range. In the lateral range over the entire length of the waist, it becomes shorter as it approaches the edge of the waist opening,
The dimension in the orthogonal direction of the imperforate zone in the central range and the dimension in the orthogonal direction of the imperforate zone in the side regions are such that the longest dimension is 1.5 to 2.5 times the shortest dimension, respectively. and
The dimension of the plurality of imperforate bands in the waist portion in the orthogonal direction is 2 to 5 mm ;
A disposable wearing article characterized by: The elastic sheet is an elastic film with a thickness of 20 to 40 μm,
The dimension in the orthogonal direction of the non-porous band in the waist adjacent portion is 0.25 times or less the dimension in the orthogonal direction of the plurality of non-porous bands in the waist portion, or There is no imperforate zone,
The disposable wearing article according to claim 1. The joining hole located in the joining zone of the waist portion has a natural length shape that is elongated in the width direction and has a straight upper edge and a lower edge.
The disposable wearing article according to claim 1 or 2. An integral exterior body spanning from the front body to the back body, or an exterior body provided separately on the front body and the back body, and an interior body attached to the widthwise middle part of this exterior body and extending across both front and rear sides of the crotch area. , a pants-type disposable wearing article comprising a side seal portion in which both sides of the exterior body in the front body and both sides of the exterior body in the back body are respectively joined, a waist opening and a pair of left and right leg openings. hand,
the exterior body is the elastic member;
The disposable wearing article according to any one of claims 1 to 3 .

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