JP7129179B2 - Elastic structure of absorbent article - Google Patents

Description

TECHNICAL FIELD The present invention relates to a stretchable structure of an absorbent article with improved fit to a local three-dimensional projection on the surface of the body and its surroundings.

In an absorbent article, in order to improve the fit to the body surface, it is common to impart stretchability to appropriate portions such as around the legs and around the waist. Conventionally, as a method for imparting elasticity, a method of arranging a large number of elongated elastic members such as rubber threads and fixing them in a state of being stretched in the longitudinal direction has been widely adopted. As a method, a method has been proposed in which an elastic sheet is attached while being stretched in the direction in which elasticity is imparted. (See Patent Document 1, for example).

In the laminated stretchable structure in which the elastic sheet is sandwiched between cover layers, the elastic sheet is placed between a first cover layer made of a non-stretchable material such as non-woven fabric and a second cover layer made of a non-stretchable material such as non-woven fabric. It is laminated. While the elastic sheet is stretched in the stretching direction (one direction perpendicular to the thickness direction), the first cover layer and the second cover layer are arranged in the stretching direction and in the direction perpendicular to the stretch direction. At the joining portion, the elastic sheet is joined through a through hole formed in the elastic sheet. In the state of natural length, shrinkage wrinkles are formed in the first cover layer and the second cover layer as the elastic sheet shrinks, and in the state of maximum elongation (elastic limit state), the first cover layer elongates the elastic sheet. and the second cover layer becomes taut, and shrinkage wrinkles disappear. This laminated stretchable structure has excellent planar fit, and there is no bonding between the first cover layer and the second cover layer and the elastic sheet, and there is very little bonding between the first cover layer and the second cover layer. Therefore, it is very flexible, and there is an advantage that the through-holes in the elastic sheet also contribute to the improvement of air permeability.

However, the stretching direction of such a laminated stretchable structure is limited to the direction in which the elastic sheet is stretched at the time of manufacture, that is, the direction orthogonal to the thickness direction. Therefore, there is room for improvement in fit to local three-dimensional projections on the body surface such as the iliac crest and the anterior superior iliac spine and their surroundings.

In addition, in the above-described laminated elastic structure, since the stretched elastic sheet is sandwiched between the first cover layer and the second cover layer, the arrangement of the elastic structure is limited depending on the product structure and manufacturing method. Furthermore, in the laminated elastic structure described above, shrinkage wrinkles inevitably formed in the first cover layer and the second cover layer provide an appearance peculiar to disposable diapers.

On the other hand, there is also known a laminated elastic structure in which a cover layer in which linear slits are formed in a non-stretchable material such as a non-woven fabric is integrated with an elastic sheet (see Patent Document 3). In the laminated stretchable structure using the cover layer having the slit, even if the elastic sheet is integrated with the cover layer in a non-stretched state, the slit can be opened so as to widen toward the center, thereby reducing the opening deformation. It becomes possible to expand and contract mainly in the direction crossing the slit within the range. Of course, even when the elastic sheet is integrated with the slit sheet in a stretched state, the laminated elastic structure using the cover layer having slits can be stretched in the direction in which the elastic sheet was stretched at the time of manufacture. It becomes possible to expand and contract in the direction orthogonal to the slit within the range of opening deformation of the slit. However, the opening deformation of a linear slit is subject to many restrictions, such as the direction.

Further, as another example of a laminated stretchable structure using a cover layer having slits, a structure in which a cover layer in which a large number of fine linear slits are arranged in a dense zigzag pattern and an elastic sheet are integrated has been proposed. (see Patent Document 4). In this case, by opening each slit so as to widen toward the center, the cover layer extends in a direction perpendicular to the slit and forms an oblique mesh. However, in this case as well, since the slits are linear, the direction and degree of expansion/contraction are limited.

Japanese Patent Publication No. 2004-532758 JP 2016-189826 A JP 2015-173689 A Japanese Patent Publication No. 2006-511375

Accordingly, the main object of the present invention is to provide a stretchable structure of an absorbent article that is excellent in fit to the local three-dimensional projections on the surface of the body and their surroundings.

Various aspects of the elastic structure of the absorbent article that solves the above problems are as follows.
<First Aspect>
The elastic sheet, the first cover layer covering the front side of the elastic sheet, and the second cover layer covering the back side of the elastic sheet are integrated,
The first cover layer and the second cover layer have no stretchability,
having a three-dimensional deformation region in a region where the first cover layer, the second cover layer and the elastic sheet overlap;
The first cover layer and the second cover layer in the three-dimensionally deformable region are provided with a plurality of slits or slits formed of perforations for forming slits,
The plurality of slits extend across the three-dimensional deformation area from one edge to the other edge of the three-dimensional deformation area,
The plurality of slit portions intersect with each other,
All portions of the first cover layer and the second cover layer located within the three-dimensional deformation area are continuous with portions located outside the three-dimensional deformation area without passing through the slit section.
An elastic structure of an absorbent article characterized by:

(Effect)
In the elastic structure of the absorbent article of this aspect, the first cover layer and the second cover layer are deformed such that the plurality of slits widen as they approach the crossing position, and the elastic sheet widens each slit. It is elastically extensible depending on the As a result, when a force is applied to the three-dimensional deformation region from one side to the other in the thickness direction, the three-dimensional deformation region follows the force and extends mainly in a plurality of directions perpendicular to the slits. , can be deformed to be recessed relative to the surrounding portion. Therefore, if such a three-dimensional deformation area that undergoes concave deformation is provided at a position in contact with a local three-dimensional convex portion on the body surface, the fit to the convex portion and its surrounding portion will be excellent.
In addition, since the three-dimensional deformation area is determined by the plurality of slits, compared to the conventional example based on a single linear slit, there is no restriction on the direction of expansion and contraction, and the degree of expansion and contraction can be increased. can.
Furthermore, since all the portions of the first cover layer and the second cover layer located within the three-dimensional deformation area are continuous with the portions located outside the three-dimensional deformation area without passing through the slit portion, the existing In the manufacturing equipment, it is possible to manufacture by simply providing the slit portions in the first cover layer and the second cover layer.

<Second Aspect>
In the three-dimensionally deformable region, when the elastic sheet is in a natural length state, shrinkage wrinkles caused by contraction of the elastic sheet are not formed in the first cover layer and the second cover layer.
The elastic structure of the absorbent article of the first aspect.

(Effect)
The elastic structure by the slit portion may be attached with the elastic sheet stretched at the time of manufacture, but it is not necessary. Therefore, by integrating the elastic sheet with the first cover layer and the second cover layer in a substantially unstretched state at the time of manufacture, wrinkles (including folds) are not formed as in this embodiment, and the elastic sheet has a good appearance. structure. In this case, since only the slits are provided in the first cover layer and the second cover layer, there is an advantage that the elastic sheet is neatly hidden by the first cover layer and the second cover layer in the natural length state.

<Third Aspect>
The slit portion includes a plurality of slit portions that pass through the central portion of the three-dimensional deformation area and extend to the edges of the three-dimensional deformation area at both ends,
The stretchable structure of the absorbent article according to the first or second aspect.

(Effect)
The slit part can include a plurality of slits passing through the central part as in this aspect. In this case, the slit portion extends radially (including X-shape and cross-shape) from the central portion of the three-dimensional deformation area. In this aspect, a wide range of three-dimensional deformation regions can be formed with a minimum number of slits. This aspect is suitable when the three-dimensional deformation area is a circle, an ellipse, or a rhombus.

<Fourth Aspect>
The slit portion includes a central slit portion that passes through the center of the three-dimensional deformation area and has both ends extending to the edges of the three-dimensional deformation region, and a central slit portion that passes through the ends of the central slit portion and has both ends of the three-dimensional shape. and an end slit extending to the edge of the deformation region,
The elastic structure of the absorbent article according to any one of the first to third aspects.

(Effect)
As in this aspect, it can include a central slit and end slits passing through the ends thereof. In this case, the slit portion extends in a T-shape, an H-shape, or the like. This aspect is suitable when the three-dimensional deformation area is triangular or rectangular.

<Fifth Aspect>
The absorbent article is
having a crotch portion including the center in the front-rear direction, a ventral portion extending forward from the center in the front-rear direction, and a dorsal portion extending rearward from the center in the front-rear direction,
Having an absorber built in a range including the crotch part,
The ventral portion and the dorsal portion have side flap portions extending to both left and right sides from the absorbent body,
The side flap portion of the dorsal portion has connecting means for detachably connecting the dorsal portion and the ventral portion,
The outer surface of the ventral portion has a target portion to which the connecting means is connected,
It is a tape type disposable diaper,
The three-dimensional deformation area is at least one of the width direction inner side of the connecting means in the side flap portion of the dorsal portion and the width direction outer side of the target portion in the side flap portion of the ventral portion,
The elastic structure of the absorbent article according to any one of the first to fourth aspects.

(Effect)
In the tape-type disposable diaper, the widthwise inner side of the connection means in the side flap portion of the dorsal portion and the widthwise outer side of the target portion of the side flap portion of the ventral portion are the iliac crest and the anterior superior iliac spine. It is a part that touches the local three-dimensional convex part of the body surface. Therefore, it is desirable to provide a three-dimensional deformation area having the aforementioned slit portion at this portion.

<Sixth Aspect>
A waist stretchable sheet that elastically stretches in the width direction is attached to the back portion over at least the left and right side flaps,
The region having the waist stretch sheet is elastically stretchable in the width direction together with the waist stretch sheet,
Having the three-dimensional deformation area between the waist elastic sheet and the connecting means,
The elastic structure of the absorbent article of the fifth aspect.

(Effect)
It is known to attach a waist elastic sheet like this aspect to the back portion of a tape-type disposable diaper to improve the fit around the waist. It is often difficult to provide such a waist elastic sheet close to the connecting means. This is because most tape-type disposable diapers are manufactured so that the front-rear direction of the product matches the MD direction (machine direction) of the production line, and the waist elastic sheet is attached while being stretched in the width direction. This is due to the need, etc. However, the portion between the waist stretchable sheet and the connecting means is located in the side flap portion and is the portion in contact with the iliac crest as described above. Therefore, it is preferable to provide the three-dimensional deformation area having the aforementioned slit portion at this portion. The above-mentioned three-dimensionally deformable region having slits can be manufactured by providing slits in advance in the first cover body and the second cover body, and simply arranging the elastic sheet in a substantially unstretched state. A three-dimensional deformation area can be formed even in a difficult position.

ADVANTAGE OF THE INVENTION According to this invention, advantages, such as becoming excellent in the fitting property with respect to the local three-dimensional convex part of a body surface, and its surrounding part, are brought about.

Fig. 2 is a plan view showing the inner surface of the tape-type disposable diaper when the diaper is unfolded; Fig. 2 is a plan view showing the outer surface of the tape-type disposable diaper when the diaper is unfolded; 6 is a cross-sectional view taken along line 6-6 of FIG. 1; FIG. FIG. 7 is a cross-sectional view taken along line 7-7 of FIG. 1; 1. (a) A cross-sectional view taken along the line 8-8 in FIG. 1, and (b) a cross-sectional view taken along the line 9-9 in FIG. (a) A cross-sectional view taken along line 5-5 in FIG. 1, and (b) a cross-sectional view in a deformed state. They are (a) the top view in the expansion|deployment state of a waist elastic sheet, and (b) sectional drawing. It is a top view which shows various slit parts. FIG. 10 is a plan view showing various examples of arrangement of three-dimensional deformation areas; FIG. 4 is a perspective view showing a deformed state of a three-dimensional deformation area;

1 to 6 show an example of a tape-type disposable diaper, where X in the figures indicates the total width of the diaper excluding the connecting tape, and L indicates the total length of the diaper. A dotted pattern portion indicates a hot-melt adhesive as a joining means for joining each component located on the front side and the back side. The hot melt adhesive is applied by known methods such as slot coating, continuous line or dotted line bead coating, spiral or Z-shaped spray coating, or pattern coating (transfer of hot melt adhesive by letterpress method). can be applied. Alternatively or additionally, at the fixing portion of the elastic member, a hot melt adhesive can be applied to the outer peripheral surface of the elastic member to fix the elastic member to the adjacent member. Hot-melt adhesives include, for example, EVA-based, adhesive rubber-based (elastomer-based), olefin-based, and polyester-polyamide-based adhesives, and can be used without particular limitation. As a joining means for joining each constituent member, a means by material welding such as heat sealing or ultrasonic sealing can be used.

This tape-type disposable diaper has a crotch portion including the center in the front-rear direction LD, an abdominal portion F extending forward from the center in the front-rear direction LD, and a back portion B extending rearward from the center in the front-rear direction LD. is doing. In addition, this tape-type disposable diaper includes an absorbent body 56 built in a region including the crotch portion, a liquid-permeable top sheet 30 covering the front side of the absorbent body 56, and a liquid-impermeable top sheet 30 covering the back side of the absorbent body 56. It has a sheet 11 and an exterior nonwoven fabric 12 that covers the back side of the liquid-impermeable sheet and constitutes the outer surface of the product. On the other hand, on both sides in the width direction from the ventral portion F to the dorsal portion B, side flap portions SF having no absorber 56 are formed, and the side flap portions SF of the dorsal portion B increase toward the rear It has a leg-surrounding edge 10 extending to be positioned laterally and a waist-surrounding forming region 80 positioned behind the leg-surrounding edge 10 . The waist region 80 of the dorsal portion B has a connecting tape 13 detachably connected to the outer surface of the ventral portion F. As shown in FIG. The connecting tape 13 is connected to the outer surface of the ventral portion F in the mounted state. As shown in FIG. 2 and the like, the side flaps of the ventral portion F also have leg-surrounding edges 10 that extend laterally toward the front, and waist-surroundings that are located behind the leg-surrounding edges 10 . It has a configuration area 80 . The leg-surrounding edges 10 of the ventral portion F and the back portion B are continuous, and the middle of the tape-type disposable diaper in the front-rear direction LD is constricted. The illustrated tape-type disposable diaper also has a pair of end flap portions EF that do not have the absorbent body 56 and extend to the front and rear sides of the absorbent body 56, respectively.

The materials and characteristic parts of each part will be described in order below.
(Absorber)
The absorbent body 56 is a part that absorbs and retains the excreted fluid, and can be formed by an assembly of fibers. The filament assembly may be a filament assembly obtained by laminating short fibers such as cotton pulp or synthetic fibers, or by opening tows (fiber bundles) of synthetic fibers such as cellulose acetate as necessary. can also be used. The fiber basis weight can be, for example, about 100 to 300 g/m ² when piling up cotton-like pulp or short fibers, and for example, about 30 to 120 g/m ² for filament aggregates. can be done. The fineness of synthetic fibers is, for example, 1 to 16 dtex, preferably 1 to 10 dtex, more preferably 1 to 5 dtex. In the case of a filament assembly, the filaments may be non-crimped fibers, but crimped fibers are preferred. The degree of crimping of the crimped fibers can be, for example, about 5 to 75, preferably 10 to 50, more preferably 15 to 50 per 2.54 cm. Further, uniformly crimped crimped fibers can be used.

(superabsorbent polymer particles)
Absorbent body 56 may contain superabsorbent polymer particles in part or in its entirety. Superabsorbent polymer particles include "powder" in addition to "particles". As the superabsorbent polymer particles 54, those used in this type of absorbent article can be used as they are. Although the particle size of the superabsorbent polymer particles is not particularly limited, for example, sieving using a 500 μm standard sieve (JIS Z8801-1: 2006) (shaking for 5 minutes), and particles falling under the sieve in this sieving When sieving (shaking for 5 minutes) using a 180 μm standard sieve (JIS Z8801-1: 2006), the percentage of particles remaining on the 500 μm standard sieve is 30% by weight or less, and the 180 μm standard sieve It is desirable that the proportion of particles remaining on the top is 60% by weight or more.

Materials for the superabsorbent polymer particles may be used without any particular limitation, but those having a water absorption of 40 g/g or more are suitable. Superabsorbent polymer particles include starch-based, cellulose-based, and synthetic polymer-based particles. and acrylic acid (salt) polymers can be used. As for the shape of the superabsorbent polymer particles, the powder particles that are commonly used are suitable, but other shapes can also be used.

As the superabsorbent polymer particles, those having a water absorption rate of 70 seconds or less, particularly 40 seconds or less are preferably used. If the water absorption rate is too slow, the liquid supplied into the absorbent body 56 tends to return to the outside of the absorbent body 56, which is called reversion.

As the superabsorbent polymer particles, those having a gel strength of 1000 Pa or more are preferably used. As a result, even when the absorbent body 56 is bulky, it is possible to effectively suppress the feeling of stickiness after liquid absorption.

The basis weight of the superabsorbent polymer particles can be appropriately determined according to the absorption amount required for the use of the absorbent body 56 . Therefore, although it cannot be generalized, it can be 50 to 350 g/m ² . If the basis weight of the polymer is less than 50 g/m ² , it becomes difficult to secure the absorption capacity. If the amount exceeds 350 g/m ² , not only the effect is saturated, but also the excessive superabsorbent polymer particles give a gritty feeling of discomfort.

(packaging sheet)
In order to prevent the superabsorbent polymer particles from slipping out or to improve the shape retention of the absorbent body 56, the absorbent body 56 can be incorporated as an absorbent element 50 wrapped with a wrapping sheet 58. FIG. As the wrapping sheet 58, tissue paper, especially crepe paper, nonwoven fabric, poly-laminated nonwoven fabric, a sheet with small holes, or the like can be used. However, it is desirable that the sheet is such that the superabsorbent polymer particles do not escape. When non-woven fabric is used instead of crepe paper, hydrophilic SMMS (spunbond/meltblown/meltblown/spunbond) nonwoven fabric is particularly suitable, and polypropylene, polyethylene/polypropylene, etc. can be used as the material. The fiber basis weight is preferably 5 to 40 g/m ² , particularly 10 to 30 g/m ² .

As shown in FIGS. 3 and 5, the packaging sheet 58 may have a structure in which a single sheet wraps the entire absorbent body 56, or a plurality of sheets, such as two upper and lower sheets, may wrap the entire absorbent body 56. Good . The packaging sheet 58 can also be omitted.

(top sheet)
The top sheet 30 is liquid-permeable, and may be, for example, a perforated or non-perforated nonwoven fabric, a porous plastic sheet, or the like. In addition, among these, 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. For example, if flexibility and drapeability are desired, the spunlace method is preferable, and if bulkiness and softness are desired, the thermal bond method is the preferable processing method.

The top sheet 30 extends from the front end to the rear end of the product in the front-rear direction, and extends laterally from the absorbent body 56 in the width direction WD. If necessary, such as when the top sheet 30 is located on the center side in the width direction, the width of the top sheet 30 may be made shorter than the total width of the absorbent body 56, and other suitable modifications may be made.

(intermediate sheet)
An intermediate sheet (also called a “second sheet”) 40 having a faster liquid permeation rate than the top sheet 30 can be provided in order to quickly transfer the liquid that has permeated the top sheet 30 to the absorbent body. The intermediate sheet 40 is intended to quickly transfer the liquid to the absorbent body to enhance the absorption performance of the absorbent body and to prevent the phenomenon of "backflow" of the absorbed liquid from the absorbent body. The intermediate sheet 40 can also be omitted.

Examples of the intermediate sheet 40 include materials similar to those of the top sheet 30, spunlace nonwoven fabric, spunbond nonwoven fabric, SMS nonwoven fabric, pulp nonwoven fabric, mixed sheet of pulp and rayon, pointbond nonwoven fabric, and crepe paper. In particular, an air-through nonwoven fabric is preferred because it is bulky. Composite fibers having a core-sheath structure are preferably used for the air-through nonwoven fabric. In this case, the resin used for the core may be polypropylene (PP), but polyester (PET) having high rigidity is preferable. The basis weight is preferably 17-80 g/m ² , more preferably 25-60 g/m ² . The thickness of the raw fibers of the nonwoven fabric is preferably 2.0 to 10 dtex. In order to make the non-woven fabric bulky, it is also preferable to use eccentric fibers, hollow fibers, or eccentric and hollow fibers whose core is not in the center as mixed fibers of all or part of the raw material fibers.

The intermediate sheet 40 in the illustrated example is shorter than the width of the absorbent body 56 and arranged in the center, but it may be provided over the entire width. Further, the intermediate sheet 40 may be provided over the entire length of the diaper, or may be provided only in the intermediate portion including the excretion position as shown in the illustrated example.

(liquid-impermeable sheet)
The liquid-impermeable sheet 11 is not particularly limited, but preferably has moisture permeability. As the liquid-impermeable sheet 11, for example, an inorganic filler is kneaded in an olefin resin such as polyethylene or polypropylene, the sheet is molded, and then the sheet is stretched in a uniaxial or biaxial direction. A sheet can be preferably used. Moreover, as the liquid-impermeable sheet 11, a non-woven fabric as a base material with improved waterproofness can also be used.

It is desirable that the liquid-impermeable sheet 11 extends in the same or wider range than the absorbent body 56 in the front-rear direction LD and the width direction WD. A structure in which the end portions of the absorber 56 are not covered in the front-rear direction LD and the width direction WD may also be employed.

(exterior non-woven fabric)
The exterior nonwoven fabric 12 covers the entire back side of the liquid-impermeable sheet 11 to give the outer surface of the product a cloth-like appearance. The exterior nonwoven fabric 12 is not particularly limited, and examples of raw material fibers include olefin-based, polyester-based, and polyamide-based synthetic fibers such as polyethylene or polypropylene, regenerated fibers such as rayon and cupra, and natural fibers such as cotton. A spunlace method, a spunbond method, a thermal bond method, an air through method, a needle punch method, or the like can be used as a processing method. However, spunbond nonwoven fabrics, SMS nonwoven fabrics, SMMS nonwoven fabrics, and other long-fiber nonwoven fabrics are suitable because they can achieve both good texture and strength. The non-woven fabric can be used singly or in multiple layers. In the latter case, it is preferable to bond the nonwoven fabrics together with a hot-melt adhesive or the like. When non-woven fabric is used, its fiber basis weight is preferably 10 to 50 g/m ² , particularly 15 to 30 g/m ² .

(Getting up gathers)
On both sides of the top sheet 30 in the width direction WD, rise gathers 60 standing up toward the wearer's skin are provided in order to prevent excrement from moving laterally along the top sheet 30 and prevent so-called side leakage. preferably. Of course, the rising gathers 60 can be omitted.

When adopting the rising gathers 60, the structure is not particularly limited, and any known structure can be adopted. The illustrated rising gathers 60 are composed of a gathering sheet 62 substantially continuous in the width direction WD, and an elongated gathering elastic member 63 fixed to the gathering sheet 62 in a stretched state along the front-rear direction LD. ing. As the gather sheet 62, a water-repellent nonwoven fabric can be used, and as the gather elastic member 63, thread rubber or the like can be used. The elastic member may be provided in a plurality of pieces as shown in FIGS. 1 and 2, or may be provided in a single piece.

The inner surface of the gather sheet 62 has a joining start end in the width direction WD on the side of the top sheet 30, and the portion outside the joining start end in the width direction is the inner surface of each side flap portion SF, that is, the liquid impermeable in the illustrated example. The nonwoven fabric 12 is bonded to the side of the adhesive sheet 11 and to the side of the exterior nonwoven fabric 12 positioned on the outside in the width direction thereof with a hot-melt adhesive or the like.

Around the legs, the width direction inner side from the joining start end of the rising gathers 60 is fixed on the top sheet 30 at both ends in the front and back direction of the product, but the portion in between is a non-fixed free portion. It rises due to the contractile force of the elastic member 63 and comes to adhere to the surface of the body.

(flat gather)
A side elastic member 64 made of an elongated elastic member such as rubber thread is fixed to each side flap portion SF while being stretched along the front-rear direction LD. is constructed as a planar gather. As shown in the figure, the leg elastic members 64 are provided between the gathered sheet 62 and the liquid-impermeable sheet 11 on the outside in the width direction near the joining start end of the joined portion of the gathered sheet 62. It can also be provided between the liquid-impermeable sheet 11 and the exterior nonwoven fabric 12 in the SF. A plurality of leg-surrounding elastic members 64 may be provided on each side as in the illustrated example, or only one leg-surrounding elastic member 64 may be provided on each side.

(connecting tape)
A connecting tape 13 as a connecting means that is detachably connected to the outer surface of the ventral portion F is provided in the waist forming region 80 in the dorsal portion B, respectively. When wearing the diaper, the connecting tape 13 is wrapped around the outer surface of the abdominal portion F from both sides of the waist, and the connecting portions 13A of the connecting tape 13 are connected to the outer surface of the abdominal portion F at appropriate locations.

The structure of the connecting tape 13 is not particularly limited, but in the illustrated example, a sheet base material forming a tape attachment portion 13C fixed to the waist forming region 80, a tape main body portion 13B projecting from the tape attachment portion 13C, and this A connecting portion 13A for the ventral side is provided in the widthwise intermediate portion of the tape main body portion 13B of the sheet base material, and the leading end side of the connecting portion 13A serves as a knob portion. The shape of the connecting tape 13 is also not particularly limited, but the tape attachment portion 13C has the longest longitudinal dimension and has a constant portion, and the tape body portion 13B has a tapered shape that tapers toward the tip. can be done. Also, the longitudinal dimension of the tape attachment portion 13C is preferably 50 to 90% of the longitudinal dimension of the waist forming region 80, and is preferably longer than the longitudinal dimension Y1 of the three-dimensional deformation region 90, which will be described later.

As the connection portion 13A, a hook member (male member) of a mechanical fastener (surface fastener) may be provided, or an adhesive layer may be provided. The hook material has a large number of engaging projections on its connection surface, and the shapes of the engaging projections are (A) square-shaped, (B) J-shaped, (C) mushroom-shaped, and (D). Although there are a T shape, (E) a double J shape (a shape in which two J shapes are joined back to back), and the like, any shape may be used.

Further, as the sheet base material forming the tape attachment portion 13C to the tape main body portion 13B, nonwoven fabric, plastic film, poly-laminated nonwoven fabric, paper, or a composite material thereof can be used. , a basis weight of 20 to 100 g/m ² and a thickness of 1 mm or less.

(Target part)
It is preferable to provide a target portion at a connecting portion of the connecting tape 13 in the ventral portion F. As shown in FIG. The target portion can be provided by attaching a target sheet 20 to the outer surface of the ventral portion F for facilitating connection, as shown in the illustrated example. When the connecting portion 13A is a hook material, the target sheet 20 may be one in which a large number of loop threads are provided on the surface of a sheet base material made of a plastic film or a non-woven fabric so that the engaging protrusions of the hook material can be entangled. Further, in the case of the adhesive layer, a sheet substrate made of a plastic film having a smooth surface and having high adhesiveness and having a release treatment applied to the surface thereof can be used. In addition, when the connecting portion of the connecting tape 13 in the ventral portion F is made of nonwoven fabric, for example, when the outer nonwoven fabric 12 is provided as shown in the figure, the target sheet 20 is omitted and the hook material is used as the fiber of the outer nonwoven fabric 12. It can also be tangled and connected. In this case, a target sheet 20 as a mark may be provided between the outer nonwoven fabric 12 and the liquid-impermeable sheet 11, or a mark may be printed on the outer surface of the outer nonwoven fabric 12 or the liquid-impermeable sheet 11.

(Waist elastic sheet)
A waist stretchable sheet 70 elastically stretchable in the width direction WD is attached at least between the left and right connecting tapes 13 in the back portion B, and the region having the waist stretchable sheet 70 is elastically stretchable in the width direction WD. It is preferable to have The waist stretchable sheet 70 may be positioned only at the end flap portion EF, but if it is arranged so as to extend from the end flap portion EF to the rear end portion of the absorbent body 56 as in the illustrated example, the absorbent body 56 It is preferable because the rear end of the is firmly pressed against the body.

The waist elastic sheet 70 may be made of a sheet-like elastic member such as a rubber sheet, but preferably has air permeability. In this case, a sheet-like elastic member having air permeability such as a stretchable nonwoven fabric can be used, but as shown in FIGS. It is preferable that the support layers 71 are bonded together with an agent, and an elastic member 72 such as a perforated sheet-like, net-like, or elongated (thread-like or string-like) elastic member 72 is fixed in a state of being stretched along the width direction WD. used for As the material of the support layer 71 in this case, the same material as the exterior nonwoven fabric 12 can be used. The elongation rate of the elastic member 72 is preferably about 150-250%. When an elongated (thread-like or string-like) elastic member 72 is used, it is preferable to provide about 5 to 15 elastic members having a thickness of 420 to 1120 dtex at intervals 72d of 3 to 10 mm.

Although the width of the waist stretchable sheet 70 can be appropriately determined, it is preferable that the width extends between the left and right side flap portions SF as shown in the illustrated example. As for specific dimensions, the width of the waist elastic sheet 70 is preferably about 80 to 95% of the total width X of the body portion excluding the connecting tape 13 .

Both ends of the waist stretchable sheet 70 in the width direction WD may be non-stretchable regions 76 for holding and attaching by suction during manufacturing. The dimensions of the non-stretchable regions 76 and the dimensions of the intermediate stretchable region 75 positioned between them and stretchable in the width direction WD can be determined as appropriate. The width of the non-stretchable region 76 is preferably 45 to 90% of the width between the connecting portions 13A, and the width of the non-stretchable region 76 is preferably about 5 to 50 mm in order to prevent shrinkage and tearing during manufacturing. The non-stretchable region 76 may be a region that does not have the elastic member 72. However, the elastic member 72 is attached over the middle stretchable region 75 and the non-stretchable region 76, and the elastic member 72 is cut in the non-stretchable region 76. A structure in which the elastic member 72 remains in the region 76 but hardly or not stretches at all may be employed.

Also, a part of the elastic member 72 can be arranged so as to traverse the absorbent body 56, but as shown in FIG. Therefore, if the elastic member 72 remains but does not expand or contract at all, the rear end portion of the absorbent body 56 does not shrink in the width direction, so that the fit is further improved.

The waist elastic sheet 70 is arranged between the liquid-impermeable sheet 11 and the absorbent element 50 in the illustrated example, but is not particularly limited to this arrangement. For example, the waist elastic sheet 70 may be arranged between the liquid-impermeable sheet 11 and the exterior nonwoven fabric 12 , or may be provided outside the exterior nonwoven fabric 12 . Moreover, when forming the exterior nonwoven fabric 12 by stacking a plurality of sheets, the entire waist elastic sheet 70 may be provided between the sheets of the exterior nonwoven fabric 12 .

(Three-dimensional deformation area)
Characteristically, as shown in FIGS. 1, 6, and 8, a three-dimensional deformation region 90 that is concavely deformed is provided inside the side flap portion of the back portion B in the width direction WD from the connecting tape 13. there is That is, in this three-dimensional deformation area 90, an elastic sheet 93 having a size that covers the inside and outside of the three-dimensional deformation area 90, a first cover layer 91 that covers the front side of the elastic sheet 93, and a second cover layer 92 that covers the back side. are integrated. That is, in this example, the first cover layer 91 is made of the gather sheet 62 and the second cover layer 92 is made of the exterior nonwoven fabric 12 . Although each of the first cover layer 91 and the second cover layer 92 is composed of a single layer sheet in this example, at least one of them may be composed of an integrated multi-layer sheet. In addition, it goes without saying that the materials for the first cover layer 91 and the second cover layer 92 differ from those of this example, depending on the position where the three-dimensionally deformable region 90 is formed. Further, if the first cover layer 91 and the second cover layer 92 do not have stretchability, the sheets contained therein may contain stretchable sheets, but both the front and back sides are made of nonwoven fabric. It is preferable that Not having stretchability (non-stretchable) means that the stretch ratio at the elastic limit is 1.0 to 1.3 times in all directions perpendicular to the thickness direction.

The elastic sheet 93 is not particularly limited, and may be an elastic film or a stretchable nonwoven fabric as long as it is a sheet that itself has elasticity. Moreover, as the elastic sheet 93, in addition to the non-perforated one, the one having many holes or slits for ventilation can be used. Although the elastic sheet 93 is not limited by its characteristics, for example, it has a tensile strength of 8 to 25 N/35 mm in the width direction WD (stretching directions ED and MD), and a tensile strength of 8 to 25 N/35 mm in the front-rear direction LD (directions perpendicular to the stretching direction XD and CD). direction) of 5 to 20 N/35 mm, a tensile elongation of 450 to 1050% in the width direction WD, and a tensile elongation of 450 to 1400% in the longitudinal direction LD. Although the thickness of the elastic sheet 93 is not particularly limited, it can be, for example, about 20 to 40 μm.

The first cover layer 91 and the elastic sheet 93, and the second cover layer 92 and the elastic sheet 93 can be integrated by bonding with a hot melt adhesive, or by welding at least one of them. In addition, the first cover layer 91, the elastic sheet 93 and the second cover layer 92 are intermittently joined even if the entire adjacent layers are continuously joined as long as they are integrally stretchable. good too. In addition, by adopting the integration method shown in Japanese Patent Application Laid-Open No. 2004-532758 and Japanese Patent Application Laid-Open No. 2016-189826, the elastic sheet 93 is sandwiched between the first cover layer 91 and the second cover layer 92. The first cover layer 91 and the second cover layer 92 may be joined at multiple joints through through-holes formed in the elastic sheet 93 (not shown) by performing ultrasonic sealing in a scattered manner.

Also, characteristically, the first cover layer 91 and the second cover layer 92 in the three-dimensional deformation area 90 are provided with a plurality of slits 95 and 96, which are slits or perforations for forming slits. there is These slits 95 and 96 extend across the three-dimensional deformation area 90 from one edge to the other edge of the three-dimensional deformation area 90 and intersect each other. All the portions of the first cover layer 91 and the second cover layer 92 located within the three-dimensional deformation area 90 are continuous with the portions located outside the three-dimensional deformation area 90 without passing through the slits 95 and 96. is doing. As a result, in the three-dimensional deformation area 90 of this example, as in the examples shown in FIGS. And with the deformation of the second cover layer 92 , the elastic sheet 93 can be elastically stretched according to the expansion of the slit portions 95 and 96 .

In other words, in the three-dimensional deformation region 90, when a force is applied to the three-dimensional deformation region 90 from one side to the other in the thickness direction as indicated by the arrow in FIG. Following this, it can be deformed so as to be depressed with respect to the surrounding portion while extending mainly in a plurality of directions orthogonal to the respective slit portions 95 and 96 . Therefore, if such a three-dimensional deformation region 90 that undergoes concave deformation is provided at a position in contact with a local three-dimensional projection on the surface of the body, the fit to the projection and its surroundings will be excellent. In addition, since the three-dimensional deformation area 90 is determined by the plurality of slits 95 and 96, there is no limitation in the expansion/contraction direction and the degree of expansion/contraction is large compared to the conventional example based on a single linear slit. can be Further, all the portions of the first cover layer 91 and the second cover layer 92 located within the three-dimensional deformation area 90 are continuous with the portions located outside the three-dimensional deformation area 90 without passing through the slits 95 and 96. Therefore, it is possible to manufacture by simply providing the slit portions 95 and 96 in the first cover layer 91 and the second cover layer 92 in the existing manufacturing equipment.

The elastic structure of the slits 95 and 96 may be attached with the elastic sheet 93 stretched during manufacture. In this case, the three-dimensional deformation region 90 is formed by shrinking the first cover layer 91 and the second cover layer 92 as the elastic sheet 93 shrinks to its natural length. Shrink wrinkles are formed. Alternatively, it is possible to integrate the elastic sheet 93 with the first cover layer 91 and the second cover layer 92 in a substantially unstretched state during manufacturing. The illustrated example assumes this case, and in the state of natural length, wrinkles (including folds) are not formed in the three-dimensional deformation area 90, and the appearance is good. In particular, by providing only the slit portions 95 and 96 in the first cover layer 91 and the second cover layer 92, the elastic sheet 93 is neatly concealed by the first cover layer 91 and the second cover layer 92 in the natural length state. There is also the advantage of being

The slit portions 95 and 96 may extend not only in the front-rear direction LD and the width direction WD, but also in oblique directions. As long as the slits 95 and 96 cross the three-dimensional deformation area 90 and extend to the edges, the slits 95 and 96 may have a linear shape as shown in the drawing, or may have a curved shape such as an arc or a wavy line. The crossing angle of the two slits 95 and 96 that cross each other can be appropriately determined according to the dimensions and shape of the three-dimensional deformation area 90 and the arrangement of the slits 95 and 96. If one of the angles is an acute angle, it can be 15 degrees or more and less than 90 degrees, particularly 30 degrees or more and less than 90 degrees. The dimension of the three-dimensional deformation area 90 can be determined as appropriate, but normally, the front-rear dimension Y1 can be about 2 to 7 mm, and the width dimension X1 can be about 4 to 7 mm. As shown in FIG. 9A, the front-rear dimension Y1 is longer than the width-direction dimension X1, as shown in FIG. The dimension Y1 in the direction and the dimension X1 in the width direction may be the same. The three-dimensional deformation area 90 preferably does not include the edge of the article in its peripheral edge, but may partially include it. The number of slit portions 95 and 96 is not limited, and may be more than the illustrated example.

Arrangement of the plurality of slit portions 95 and 96 is not particularly limited. For example, as in each example shown in FIG. 8, a plurality of slit portions 95 (example of FIG. 8A) or all slit portions 95 (FIGS. 8B and 8C) are three-dimensionally deformed. It is preferable that both ends pass through the center of the region 90 and extend to the edges of the three-dimensional deformation region 90. In this case, the slit portion 95 extends radially (X-shaped or cross-shaped) from the center of the three-dimensional deformation region 90. If the slits 95 are arranged so as to radially extend from the central portion of the three-dimensional deformation area 90 in this way, three-dimensional deformation over a wide range can be achieved with a minimum number of slits 95 . It is possible to form the region 90. The arrangement of the slit portions 95 is suitable when the three-dimensional deformation region 90 is circular, elliptical, or rhombic.

As in the example shown in FIG. 8(a), the slits 95 and 96 include a central slit 95 extending through the center of the three-dimensional deformation area 90 and having both ends extending to the edges of the three-dimensional deformation area 90. It also preferably includes end slits 96 passing through the ends of the central slit and having both ends extending to the edges of the three-dimensional deformation area 90 . In this case, the slit portions 95 and 96 extend in a T-shape, H-shape, or the like. Also, the arrangement of the slits 95 and 96 is suitable when the three-dimensional deformation area 90 is triangular or rectangular. As shown in FIG. 8(d), only three or two end slit portions 96 may be provided so as to surround the three-dimensional deformation area 90 in a U-shape or V-shape.

The slit portions 95 and 96 of the first cover layer 91 and the slit portions 95 and 96 of the second cover layer 92 have the same size and shape and are arranged at the same position (that is, completely overlap in the thickness direction). Although desirable, some deviation is acceptable. Also, the slit portions 95 and 96 of the first cover layer 91 and the slit portions 95 and 96 of the second cover layer 92 may have different dimensions and shapes.

In the tape-type disposable diaper having the side flap portions SF as in this example, the target portion ( In the illustrated example, the portion outside the target sheet 20) in the width direction WD is a portion in contact with a local three-dimensional projection on the body surface such as the iliac crest and anterior superior iliac spine. Therefore, as shown in FIG. 9(a), it is also possible to provide the three-dimensional deformation area 90 having the aforementioned slits 95 and 96 in both of these parts. Also, of course, it may be provided only at one of these sites. Moreover, it is preferable to provide it in the end flap part EF of the back side part B like the example shown in FIG.9(b).

In addition, when attaching the waist elastic sheet 70 to the back side portion B to improve the fit around the waist as in the illustrated example, it is often difficult to provide the waist elastic sheet 70 close to the connecting tape 13 . This is because most tape-type disposable diapers are manufactured so that the front-rear direction LD of the product matches the MD direction (machine direction) in the production line, and the waist stretch sheet 70 is stretched in the width direction WD. This is due to the fact that it needs to be attached in a state. However, the portion between the waist stretchable sheet 70 and the connecting tape 13 is located in the side flap portion SF and is the portion in contact with the iliac crest as described above. Therefore, it is preferable to provide the three-dimensional deformation area 90 having the aforementioned slits 95 and 96 at this portion. The three-dimensional deformation area 90 having the aforementioned slits 95 and 96 can be obtained by providing the slits 95 and 96 in advance in the first cover body and the second cover body, and arranging the elastic sheet 93 in a substantially unstretched state. Therefore, the three-dimensional deformation area 90 can be formed even at a position where it is difficult to form conventionally.

<Others>
Although the three-dimensionally deformable region 90 having the slits 95 and 96 in the above example is provided in the side flap portion SF of the tape-type disposable diaper, it can also be provided in other parts and other types of products. For example, although not shown, the three-dimensional deformation area 90 having the slits 95 and 96 can be provided on the connecting tape 13 of the tape-type disposable diaper or around the waist of the pants-type disposable diaper.

<Description of terms in the specification>
The following terms in the specification have the following meanings unless otherwise specified in the specification.
・"Front-back direction" means the direction (longitudinal direction) indicated by symbol LD in the figure, and "width direction" means the direction (left-right direction) indicated by WD in the figure. are orthogonal.

- "Unfolded state" means a flat unfolded state without contraction or slack.

- "Elongation rate" means a value when the natural length is taken as 100%. For example, an elongation rate of 200% is synonymous with an elongation ratio of 2 times.

- "Gel strength" is measured as follows. Artificial urine (urea: 2 wt%, sodium chloride: 0.8 wt%, calcium chloride dihydrate: 0.03 wt%, magnesium sulfate heptahydrate: 0.08 wt%, and deionized water: 97.09 wt%) 1.0 g of superabsorbent polymer is added to 49.0 g and stirred with a stirrer. The resulting gel is left in a constant temperature and humidity bath at 40° C. and 60% RH for 3 hours, then returned to room temperature, and the gel strength is measured with a card meter (Curdmeter-MAX ME-500 manufactured by I. techno Engineering).

- "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 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 a tensile tester, for example, AUTOGRAPH AGS-G100N manufactured by SHIMADZU can be used.

・The “water absorption” is measured according to JIS K7223-1996 “Testing method for water absorption of super absorbent polymer”.

・"Water absorption rate" is "Time to end point" when JIS K7224-1996 "Test method for water absorption rate of superabsorbent polymer" is performed using 2g of superabsorbent polymer and 50g of physiological saline. and

・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.

・Unless otherwise specified, the dimensions of each part mean the dimensions in the unfolded state, not in the natural length state.

INDUSTRIAL APPLICABILITY The present invention can be applied to elastic structures in general disposable wearable articles such as various disposable diapers such as pants type and pad type, sanitary napkins, and disposable wearable articles for swimming and playing in the water, in addition to tape-type disposable diapers as described above. It is possible.

DESCRIPTION OF SYMBOLS 10... Leg peripheral edge 11... Liquid-impermeable sheet 12... Exterior nonwoven fabric 13... Connection tape 13A... Connection part 13B... Tape body part 13C... Tape attachment part 20... Target sheet 30... Top sheet , 40... Intermediate sheet, 50... Absorbent element, 56... Absorbent body, 58... Wrapping sheet, 60... Rising gather, 62... Gather sheet, B... Dorsal part, F... Abdominal part, WD... Width direction, LD... Front-and-rear direction 70 Waist stretchable sheet 80 Waist structure region 90 Three-dimensional deformation region 93 Elastic sheet 91 First cover layer 92 Second cover layer 95, 96 Slit portion 95 ... central slit portion, 96 ... end slit portion, SF ... side flap portion.

Claims (6)

An elastic sheet, a first cover layer covering the front side of the elastic sheet, and a second cover layer covering the back side of the elastic sheet ,
The elastic sheet, the first cover layer and the second cover layer are integrated by continuously bonding the entire adjacent layers ,
The first cover layer and the second cover layer have no stretchability,
having a three-dimensional deformation region in a region where the first cover layer, the second cover layer and the elastic sheet overlap;
In the three-dimensionally deformable region, when the elastic sheet is in a state of natural length, shrinkage wrinkles formed along with contraction of the elastic sheet are not formed in the first cover layer and the second cover layer,
Each of the first cover layer and the second cover layer in the three-dimensionally deformable region is provided with a plurality of slits or slits formed of perforations for forming slits,
The plurality of slits extend across the three-dimensional deformation area from one edge to the other edge of the three-dimensional deformation area,
The plurality of slit portions intersect each other at an intersection angle of 90 degrees or an acute angle side of 15 degrees or more and less than 90 degrees ,
All portions of the first cover layer and the second cover layer located within the three-dimensional deformation area are continuous with portions located outside the three-dimensional deformation area without passing through the slit section.
An elastic structure of an absorbent article characterized by: 2. The article according to claim 1 , which has a portion in contact with the iliac crest and has the three-dimensional deformation area in the portion in contact with the iliac crest, and the peripheral edge of the three-dimensional deformation area does not include the edge of the article. Elastic structure for absorbent articles. The slit portion includes a plurality of slit portions that pass through the central portion of the three-dimensional deformation area and extend to the edges of the three-dimensional deformation area at both ends,
The elastic structure of the absorbent article according to claim 1 or 2. The slit portion includes a central slit portion that passes through the center of the three-dimensional deformation area and has both ends extending to the edges of the three-dimensional deformation region, and a central slit portion that passes through the ends of the central slit portion and has both ends of the three-dimensional shape. and an end slit extending to the edge of the deformation region,
The elastic structure of the absorbent article according to any one of claims 1 to 3. The absorbent article is
having a crotch portion including the center in the front-rear direction, a ventral portion extending forward from the center in the front-rear direction, and a dorsal portion extending rearward from the center in the front-rear direction,
Having an absorber built in a range including the crotch part,
The ventral portion and the dorsal portion have side flap portions extending to both left and right sides from the absorbent body,
The side flap portion of the dorsal portion has connecting means for detachably connecting the dorsal portion and the ventral portion,
The outer surface of the ventral portion has a target portion to which the connecting means is connected,
It is a tape type disposable diaper,
The three-dimensional deformation area is at least one of the width direction inner side of the connecting means in the side flap portion of the dorsal portion and the width direction outer side of the target portion in the side flap portion of the ventral portion,
The elastic structure of the absorbent article according to any one of claims 1 to 4. A waist stretchable sheet that elastically stretches in the width direction is attached to the back portion over at least the left and right side flaps,
The region having the waist stretch sheet is elastically stretchable in the width direction together with the waist stretch sheet,
Having the three-dimensional deformation area between the waist elastic sheet and the connecting means,
The elastic structure of the absorbent article according to claim 5.

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