JP2021153898A5 - - Google Patents

Description

TECHNICAL FIELD The present invention relates to a trunks-type disposable wearing article in which the fit of tubular leg portions can be changed.

A pants-type disposable diaper has a waist opening and a pair of leg openings, an outer body extending from the edge of the waist opening on the front side to the edge of the waist opening on the rear side, and an absorbent body provided at least in the crotch portion of the outer body. and a side seal portion that joins both front and rear side portions of the exterior body.

As one form of underpants-type disposable diaper, a trunk-type disposable diaper (also called a one-quarter length shape or a boxer type) having a pair of leg cylinders surrounding the root side of the thigh is known (for example, Patent Document 1, 2).

In trunks-type disposable diapers, an elastic member is attached to the leg tube to provide the leg tube with an elastic region that elastically expands and contracts in the circumferential direction. As the elastic member attached to the leg cylinder, an elongated elastic member such as rubber thread is generally used.

Further, in trunks-type disposable diapers, there is a demand to be able to adjust the tightening pressure of the leg cylinders in accordance with the leg circumference dimensions, etc., which vary from wearer to wearer (see Patent Documents 1 and 2, for example).

JP 2015-134129 A Japanese Patent Application Laid-Open No. 2010-220980 WO2016/121975

In response to such a demand, the inventor of the present invention has found that the number of elastic members per unit contact area of the leg tube portion can be increased by turning the leg tube portion upside down and overlapping the leg tube portion as necessary. Therefore, it was found that the tightening pressure can be increased.

However, even if it is a single layer, the stretchable region formed by the elastic member forms folds (including wrinkles; the same shall apply hereinafter) when it is worn to some extent, and the thickness increases. In the case of , the thickness is further increased, and there is a possibility that the appearance and the feeling of wearing are deteriorated.

SUMMARY OF THE INVENTION Accordingly, a main object of the present invention is to suppress an increase in thickness when a stretchable tubular leg portion is turned upside down.

The trunks-type disposable wearing article that solves the above problems is as follows.
<First Aspect>
Equipped with a pair of leg cylinders surrounding the root side of the thigh,
In the leg cylinder, convex regions and concave regions are alternately and repeatedly provided adjacent to each other in a leg length direction orthogonal to the circumferential direction,
The convex region and the concave region are regions where the first sheet layer and the second sheet layer are overlapped,
The convex region has a joint portion between the first sheet layer and the second sheet layer where the first sheet layer and the second sheet layer are not joined or a space is provided between the first sheet layer and the second sheet layer. ,
the recessed region has a joint portion of the first sheet layer and the second sheet layer spaced apart;
an elastic sheet is provided between the first sheet layer and the second sheet layer at least in the recessed area;
The first sheet layer and the second sheet layer in the convex region and the concave region have folds formed by contracting in the stretching direction together with the elastic sheet and expanding in directions opposite to each other,
The convex region has a wider interval in the expansion and contraction direction of the joint than the concave region,
The convex region and the concave region each have a constant dimension in the leg length direction,
The dimension of the convex region in the leg length direction is equal to or less than the dimension of the concave region in the leg length direction,
A trunks-type disposable wearing article characterized by:

(Effect)
In the tubular leg portion of the trunks-type disposable diaper, the convex regions and the concave regions are alternately and repeatedly provided adjacent to each other in the leg length direction. In addition, at least the concave region has an elastic sheet, and the first sheet layer and the second sheet layer in the convex region and the concave region shrink in the stretching direction together with the elastic sheet in a natural length and in a state of being shrunk to some extent, while being opposite to each other. It has folds formed by swelling in the direction. Even if the convex region alone does not stretch more than the concave region (including the case where it does not have an elastic member such as an elastic sheet), it shrinks together with the adjacent concave region to form folds. Here, if the distance between the joints in the stretching direction is wider in the convex region than in the concave region, the convex region is higher than the concave region at least in the wearing state (for example, in a state of being stretched to half of the maximum stretch in the stretching direction). Large folds are formed. Therefore, one of the convex regions and the concave regions is relatively convex and the other is relatively concave due to the difference in thickness (difference in maximum elongation) due to the folds in the contracted state. With such convex regions and concave regions, the convex regions and concave regions can be meshed with each other when the wearer turns over the tubular leg portions and stacks them in a double layer or the like as necessary. Therefore, tightening pressure can be increased while suppressing an increase in thickness. Moreover, although this was not initially anticipated, the meshing of the convex and concave regions also brings about the advantage that the turned-up portion is less likely to shift.

<Second Aspect>
The elastic sheet is provided in the convex region and the concave region,
An arrangement pattern of the joints in the convex region and an arrangement pattern of the joints in the concave region are different,
The trunks-type disposable wearing article of the first aspect.

(Effect)
It is preferable to provide the elastic sheet in the convex region and the concave region because the stretchability is not interrupted in the lengthwise direction of the leg and the fit of the tubular leg portion is improved.

<Third Aspect>
Only one of the convex region and the concave region is provided at the same position in the leg length direction,
The convex region is provided at the end of the leg cylinder on the leg opening side,
The trunks-type disposable wearing article of the second aspect.

(Effect)
In the case of this aspect, it is possible to tighten firmly up to the end on the leg opening side, and the minimum turn-over length required to mesh the convex region and the concave region can be shortened, and the tightening force can be adjusted. wider range.

<Fourth Aspect>
The maximum elongation of the convex regions in the direction of stretching is 200 to 350%, and the maximum elongation of the concave regions in the direction of stretching is 0.70 to 0.95 times the maximum elongation of the convex regions in the direction of stretching. be,
The trunks-type disposable wearing article of the second or third aspect.

(Effect)
When the convex region and the concave region have an elastic sheet, one is convex and the other is concave due to the difference in maximum elongation. Therefore, the maximum elongation of the convex region and the concave region may be appropriately adjusted according to the degree of meshing desired for the convex region and the concave region, but in normal cases, it is preferably within the range of this aspect.

<Fifth Aspect>
an exterior body having a waist opening and a pair of leg openings and extending from the edge of the waist opening on the front side to the edge of the waist opening on the rear side; a side seal portion that joins both front side portions and rear side portions of the exterior body,
An annular waist portion is formed between one side seal portion and the other side seal portion in the width direction of the exterior body,
The crotch portion of the exterior body has a pair of inner thigh contact portions extending outward in the width direction from both side edges of the absorbent body, and a portion along the edge of the leg opening including these inner thigh contact portions. is the leg cylinder,
In the outer body, a region extending from the leg tube portion to at least one of the front and rear waist portions is a region having the first sheet layer, the second sheet layer, and the elastic sheet.
A trunks-type disposable wearing article according to any one of aspects 1 to 4.

(Effect)
As in this aspect, by making the trunks-type disposable wearing article having the same basic structure as the pants-type disposable wearing article without the leg tube portions, the first sheet layer and the second sheet layer common from the waist portion to the leg tube portions are provided. It is preferable because the sheet layer and the elastic sheet can be arranged to add stretchability.

ADVANTAGE OF THE INVENTION According to this invention, the advantage of becoming able to suppress the increase in thickness when the leg cylinder part which has elasticity is turned over is brought about.

Fig. 2 is a plan view (inner surface side) of the trunks-type disposable diaper in an unfolded state; Fig. 2 is a plan view (outer surface side) of the trunks-type disposable diaper in an unfolded state; It is a top view of an inner body. 4 is a cross-sectional view taken along line 4-4 of FIG. 1; FIG. FIG. 2 is a cross-sectional view taken along line 2-2 of FIG. 1; 3 is a cross-sectional view taken along line 3-3 of FIG. 1; FIG. Fig. 3 is a perspective view of the trunks-type disposable diaper in a worn state, viewed obliquely from below; Fig. 2 is a plan view showing an enlarged main part of the trunks-type disposable diaper in an unfolded state; Fig. 2 is a plan view showing an enlarged main part of the trunks-type disposable diaper in an unfolded state; It is the front schematic diagram for demonstrating the usage. Fig. 2 is a plan view showing an enlarged main part of the trunks-type disposable diaper in an unfolded state; Fig. 2 is a plan view (outer surface side) of the trunks-type disposable diaper in an unfolded state; (a) is a plan view of the main part of the expansion/contraction region in the unfolded state, (b) is a DD cross-sectional view of (a), (c) is a cross-sectional view of the attached state, and (d) is a cross-sectional view of the natural length state. be. 4A and 4B are plan views showing various shapes of joints; FIG. FIG. 4 is a plan view showing an enlarged main part of the stretchable region in the unfolded state; (a) is a plan view of the essential part of the non-stretchable region, (b) is a cross-sectional view taken along line DD of (a), (c) is a cross-sectional view of the worn state, and (d) is a cross-sectional view of the natural length state. FIG. 4 is a plan view of the main part of the non-stretchable region; FIG. 4 is a cross-sectional view schematically showing a cross-section of a principal part of an exterior body elongated to some extent; FIG. 4 is a cross-sectional view schematically showing a cross-section of a principal part of an exterior body elongated to some extent; (a) A trace diagram of a plane photograph of a joint formed in a first welding mode, (b) A trace diagram of a plane photograph of a joint formed in a third welding mode.

FIGS. 1 to 10 show a trunks-type disposable diaper (hereinafter also simply referred to as a diaper) as an example of a trunks-type disposable wearing article having a pair of leg cylinders 50. FIG. Note that points necessary for explanation among the points adhered by the hot-melt adhesive are marked with dots in the drawing. 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.

The pair of leg cylinders 50 of the trunks-type disposable diaper is not particularly limited as long as it has a tubular shape surrounding the thighs in the worn state, and the structures described in Patent Documents 1 and 2 can also be adopted. On the other hand, the illustrated trunks-type disposable diaper employs a simpler structure than those described in Patent Documents 1 and 2. As shown in FIG.

More specifically, the illustrated trunk-type disposable diaper has a waist opening WO and a pair of leg openings LO, and the outer body 20 extends from the edge of the waist opening WO of the front body F to the edge of the waist opening WO of the back body B. , the inner body 10 including the absorber 13 provided at least in the crotch portion 28 of the outer body 20, and the side seal portions 21 that join both front side portions and rear side side portions of the outer body 20. It is. In addition, the crotch portion 28 of the outer body 20 has a pair of inner thigh contact portions 51 extending from both side edges of the absorbent body 13 to one side and the other side in the width direction WD. A pair of leg tube portions 50 surrounding the base of the thigh are formed along the edge 29 of the leg opening. During manufacturing, after the inner body 10 is joined to the outer body 20 by a joining means such as a hot-melt adhesive, the inner body 10 and the outer body 20 are aligned in the front-rear direction LD at the boundary between the front body F and the back body B. The waist opening WO and a pair of leg openings LO are formed by folding the center (longitudinal direction) and joining both sides thereof by heat welding or hot-melt adhesive to form side seal portions 21. It becomes a trunk type disposable diaper.

(Example of internal body structure)
As shown in FIGS. 3 to 6, the inner body 10 has an absorbent body 13 interposed between a liquid-permeable top sheet 11 made of nonwoven fabric or the like and a liquid-impermeable sheet 12 made of polyethylene or the like. It has a structure and absorbs and retains the excreted fluid that has permeated the top sheet 11 . Although the planar shape of the interior body 10 is not particularly limited, it is generally rectangular as shown in the figure.

As the top sheet 11 that covers the front side of the absorbent body 13 and forms a skin-contacting surface, a perforated or non-perforated nonwoven fabric, a porous plastic sheet, or the like is preferably used. The material fibers that make up the non-woven fabric can be synthetic fibers such as olefins such as polyethylene or polypropylene, polyesters, and polyamides, as well as recycled fibers such as rayon and cupra, and natural fibers such as cotton. , spunbond method, thermal bond method, meltblown method, needle punch method, etc. can be used. Among these processing methods, the spunlace method is superior in flexibility and drapeability, and the thermal bond method is superior in that it is bulky and soft. When a large number of through-holes are formed in the top sheet 11, urine and the like are rapidly absorbed, and the dry touch property is excellent. In the illustrated embodiment, the top sheet 11 wraps around the side edges of the absorbent body 13 and extends to the back side of the absorbent body 13, but is not limited to this.

A liquid-impermeable plastic sheet such as polyethylene or polypropylene is used for the liquid-impermeable sheet 12 that covers the back side of the absorbent body 13. In recent years, a moisture-permeable sheet is preferably used in order to prevent stuffiness. The water-impermeable/moisture-permeable sheet is a microporous sheet obtained by, for example, forming a sheet by melt-kneading an inorganic filler in an olefin resin such as polyethylene or polypropylene, and then stretching the sheet in a uniaxial or biaxial direction. can be mentioned.

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

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

The overall shape of the absorber 13 is formed in a substantially hourglass shape with a constricted portion 13N narrower in width than both front and rear sides thereof in the front-rear direction range including the crotch portion 28, but may be any other shape such as a rectangular shape. be able to. The size of the constricted portion 13N can be determined as appropriate, but the length in the front-rear direction of the constricted portion 13N can be about 20 to 50% of the total length of the diaper, and the width of the narrowest portion 13m is the width of the entire width of the absorbent body 13. It can be about 40 to 60%. In the case where the inner body 10 has such a constricted portion 13N, if the planar shape of the inner body 10 is substantially rectangular, a portion of the inner body 10 corresponding to the constricted portion 13N of the absorbent body 13 is left without the absorbent body 13. part is formed.

Three-dimensional gathers BS are formed on both sides of the inner body 10 to fit around the legs. As shown in FIGS. 5 and 6, the three-dimensional gathers BS are composed of a fixing portion fixed to the side portion of the back surface of the inner body 10, and a front surface of the inner body 10 extending from the fixing portion to the side of the inner body 10. a main body portion extending to the sides of the main body portion, a fallen portion formed by fixing the front and rear end portions of the main body portion to the side portions of the surface of the inner body 10 in a fallen state, and the portion between the fallen portions being unfixed. The formed free portion is formed by a gather sheet 15 which is doubled by folding. A water-repellent nonwoven fabric is preferably used as the gather sheet 15 .

Also, between the double gather sheets 15, an elongated gather elastic member 16 is disposed at the tip of the free portion or the like. The gather elastic member 16 is for forming a three-dimensional gather BS by erecting a free portion by elastic expansion and contraction force, as indicated by a chain double-dashed line in FIG. 5 in the product state.

Materials such as styrene rubber, olefin rubber, urethane rubber, ester rubber, polyurethane, polyethylene, polystyrene, styrene butadiene, silicone, and polyester can be used for the gather elastic member 16 . Also, in order to make it difficult to see from the outside, it is preferable that the thickness is 925 dtex or less, the elongation rate is 150 to 350%, and the interval is 10.0 mm or less. As the gather elastic member 16, a tape-like member having a certain width can be used in addition to the filament-like one shown in the figure.

The nonwoven fabric used for the gather sheet 15 is not particularly limited, and is made of synthetic fibers such as olefin-based, polyester-based, and polyamide-based fibers such as polyethylene or polypropylene, regenerated fibers such as rayon and cupra, and natural fibers such as cotton. Also, it can be manufactured by an appropriate processing method such as a spunbond method, a thermal bond method, a meltblown method, a needle punch method, or the like. In particular, as the gather sheet 15, it is desirable to use a water-repellent non-woven fabric coated with a silicone, paraffin metal, or alkylchromic chloride water repellent to prevent permeation of urine or the like.

(Exterior body)
As shown in FIGS. 1, 2, and 8, the exterior body 20 has a substantially hourglass shape with a constricted middle in the front-rear direction LD, and both side edges of this constriction form the edges 29 of the leg openings. there is As described above, the crotch portion 28 of the outer body 20 has a pair of inner thigh contact portions 51 extending from both side edges of the absorbent body 13 to one side and the other side in the width direction WD. A portion along the edge 29 of the leg opening, including the inner thigh contact portion 51, forms a pair of leg tube portions 50 surrounding the base side of the thigh. The dimensions of the inner thigh contact portion 51 may be appropriately determined according to the length of the tubular leg portion 50, but in normal cases, the width 51x of the inner thigh contact portion 51 at the narrowest portion of the outer body 20 is equal to that of the diaper. It is preferably about 1 to 5% of the total length Y. Further, as shown in FIG. 9, in the front body F, the width direction is set at an angle θ ₁ of 20 degrees with respect to the width direction from the imaginary point P1 located on the edge 29 of the leg opening, which is the most centered in the width direction. When the imaginary straight line L1 extending outward and toward the waist side is drawn, it is preferable to have an intersection point P2 between the imaginary straight line L1 and the side edge of the exterior body 20 in the front-rear direction range having the side seal portions 21, and from this intersection point P2. The distance 50f in the front-rear direction to the edge 29 of the leg opening is preferably equal to or greater than the distance 51d between the side edge of the exterior body 20 and the side edge of the interior body 10 at the narrowest portion of the exterior body 20, and is substantially the same. Preferably. On the other hand, in the back body B, from the virtual point P1 located on the edge 29 of the leg opening at the center in the width direction to the width direction at an angle θ ₂ of 30 degrees, the virtual When the straight line L2 is drawn, it is preferable to have an intersection point P3 between the imaginary straight line L2 and the side edge of the exterior body 20 in the front-rear direction range having the side seal portion 21, and the distance from the intersection point P3 to the edge 29 of the leg opening. The space 50b in the front-rear direction may be less than or greater than the space 51d between the side edge of the exterior body 20 and the side edge of the interior body 10 at the narrowest portion of the exterior body 20 .

2, 4 to 6, and 8, the elastic sheet 30 is interposed between the first sheet layer 20A and the second sheet layer 20B. In addition, as shown in FIG. 13, the first sheet layer 20A and the second sheet layer 20B are elastically bonded through bonding holes 31 penetrating the elastic sheet 30 at a number of bonding portions 40 arranged at intervals. It has a sheet elastic structure 20X. That is, the outer peripheral edge of the joint portion 40 is surrounded by the inner peripheral edge of the joint hole 31, and the two are not joined and can be separated from each other. Although not shown, the first sheet layer 20A and the second sheet layer 20B may be joined via the elastic sheet 30 at a number of joints 40 arranged at intervals. The region having the elastic sheet stretchable structure 20X is contracted in the width direction due to the contraction of the elastic sheet 30 and is stretchable in the width direction WD (that is, the stretch direction ED becomes the width direction WD of the diaper). have an area.

Although not shown, it is possible to configure the stretchability of the region including the waist end portion 23 of the outer body 20 with an elastic sheet stretchable structure. However, in many cases, it is difficult to achieve a more suitable fit. Therefore, as shown in the figure, the waist end portion 23 is not provided with the elastic sheet elastic structure 20X, and the conventional elongated waist elastic member is used. It is also preferred to provide a telescoping structure according to 24 . The waist elastic member 24 is an elongated elastic member such as a plurality of thread rubbers arranged at intervals in the front-rear direction LD, and gives elastic force so as to tighten the circumference of the body. The waist elastic members 24 are not arranged substantially as a bundle with close intervals, but three or more at intervals of about 3 to 8 mm in the front-rear direction so as to form a predetermined elastic zone. Preferably, 5 or more are arranged. The elongation rate of the waist elastic member 24 when fixed can be determined as appropriate, but in the case of normal adult use, it can be about 230 to 320%. Although the waist elastic member 24 uses thread rubber in the illustrated example, other elongated stretchable members such as flat rubber may be used. Although not shown, an elastic sheet 30 may be provided at the waist end portion 23, and an elongated waist elastic member 24 may be provided at a position overlapping the elastic sheet 30 to form a stretchable structure by both elastic members.

As will be described later, the tubular leg portion 50 has an elastic sheet expansion/contraction structure 20X. In this case, the elastic sheet stretchable structure 20X can be configured with separate members for the leg tube portion 50 and other portions. It is preferable that the region from the leg tube portion 50 to at least one of the front and rear waist portions is a region having a single elastic sheet stretchable structure 20X. In order to form convex regions 55 and concave regions 57, which will be described later, the tubular leg portion 50 is not provided with elastic members other than the elastic sheet 30, such as elongated elastic members extending along the leg openings LO.

As shown in FIG. 12, instead of providing the elastic sheet elastic structure 20X in the waist portion other than the waist end portion 23, the elastic structure is provided by conventional elongated waist elastic members 26 such as thread rubber. can also

(stretch area)
A region having the elastic sheet stretchable structure 20X in the exterior body 20 has a stretchable region 80 that is stretchable in the width direction WD. The stretchable region 80 is contracted in the width direction WD due to the shrinkage force of the elastic sheet 30 and is expandable in the width direction WD. More specifically, in a state in which the elastic sheet 30 is stretched in the width direction WD, the elastic sheet 30 is stretched at intervals in the width direction WD and the front-rear direction LD (the direction perpendicular to the stretch direction). By joining the first sheet layer 20A and the second sheet layer 20B through the joint holes 31 to form a large number of joints 40, the elastic sheet stretchable structure 20X is formed, and the elastic sheet 30 is formed in the stretchable region 80. By arranging the joints 40 so as to remain uninterrupted in the width direction WD, and to contract the first sheet layer 20A and the second sheet layer 20B by the contraction force of the elastic sheet 30 to form the contraction folds 25. , such elasticity can be imparted.

In the stretchable region 80, even if the elastic sheet 30 has a linear continuous portion 32 along the width direction WD as in the example shown in FIG. does not have to be

In the stretchable region 80, in the natural length state, the first sheet layer 20A and the second sheet layer 20B between the joints 40 are oriented in opposite directions (separated) from each other, as shown in FIGS. 13(c) and 13(d). Inflated, contraction folds 25 extending in the front-rear direction LD are formed, and even in the mounted state in which they are stretched to some extent in the width direction WD, the contraction folds 25 are stretched but remain. Further, as shown in the illustrated example, if the first sheet layer 20A and the second sheet layer 20B are not joined to the elastic sheet 30 at least at the joining portion 40 other than between the first sheet layer 20A and the second sheet layer 20B, As can be seen from FIG. 13C, which assumes the mounted state, and FIG. Even if the edge of the joining hole 31 is separated from the outer peripheral edge of the joining portion 40 in the stretching direction to form a vent hole 33 (gap), and the material of the elastic sheet 30 is a non-porous film or sheet, the vent hole 33 is Adds breathability. In particular, when the elastic sheet 30 has a linearly continuous portion 32 along the width direction WD, further contraction of the elastic sheet 30 causes the joint hole 31 to narrow in the natural length state. A gap is hardly formed between 31 and joint portion 40, and if elastic sheet 30 does not have a linearly continuous portion along width direction WD, vent hole 33 remains.

It is desirable that the maximum elongation in the width direction WD of the elastic region 80 is 190% or more (preferably 200 to 220%). The maximum elongation of the elastic region 80 is substantially determined by the elongation rate of the elastic sheet 30 at the time of manufacture, but based on this, it decreases due to factors that inhibit contraction in the width direction WD. The main factor of such a hindrance is the ratio of the length of the joint 40 per unit length in the width direction WD, and the larger the ratio, the lower the maximum elongation. Normally, since the length of the joint 40 has a correlation with the area ratio of the joint 40 , the maximum elongation of the stretchable region 80 can be adjusted by the area ratio of the joint 40 .

When the elastic sheet 30 has a portion 32 that is linearly continuous along the width direction WD as in the example shown in FIG. It can be adjusted by the sum of the orthogonal dimension 32w (equal to the interval 31d of the joint holes in the orthogonal direction XD) of the linearly continuous portions 32 (see FIG. 13(a)) along the direction WD. On the other hand, as in the example shown in FIG. 11 and the example shown in FIG. 15, when the elastic sheet 30 does not have a linearly continuous portion along the width direction WD, the stretching stress of the stretchable region 80 is It can be adjusted by the crossing angle formed by the direction of continuation of the non-bonded bands 41 and 42 in which the portions having no joints are continuous and the stretching direction ED. It is preferable that the acute side crossing angles θ1 and θ2 formed by and the stretching direction ED are larger than 0 degrees and 45 degrees or less, particularly preferably in the range of 10 to 30 degrees.

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

In this way, the maximum elongation and elongation stress of the stretchable region 80 can be adjusted by adjusting the area ratio and spacing of the joints 40. Therefore, as shown in FIG. can be provided. Although the interval between the joints 40 is not particularly limited, for example, the interval 40d in the expansion/contraction direction can be about 0.5 to 5 times the maximum width 40x of the joints 40, and the length can be about 0.5 to 2 mm.

The shape of each joint portion 40 and joint hole 31 in the natural length state can be determined as appropriate, but may be circular, elliptical, triangular, rectangular (see FIG. 13), rhombus (see FIG. 14(b)), or the like. , a convex lens shape (see FIG. 14(a)), a concave lens shape (see FIG. 14(c)), a star shape, a cloud shape, and the like. The dimensions of the individual joints are not particularly limited, but the maximum length 40y (substantially equal to the orthogonal dimension 31y of the joint hole 31) is 0.5 to 3.0 mm, particularly 0.7 to 1.1 mm. is preferable, and the maximum width 40x is preferably 0.1 to 3.0 mm.

The arrangement pattern of the joints 40 of the elastic region 80 is not particularly limited, and any pattern (see, for example, Patent Documents 1 to 8) can be adopted. It is preferable that a non-bonded zone in which portions having no bonded portion are continuous exists in an oblique grid pattern.

(Non-stretch area)
As shown in FIG. 2, of the region having the elastic sheet stretchable structure 20X in the exterior body 20, the portion overlapping the absorber 13 may be partly or entirely (preferably including substantially the entire inner/outer fixing region 10B), or the like. A non-stretchable region 70 can be provided at the site of .

When the non-stretchable region 70 is provided in the portion overlapping with the absorbent body 13, its arrangement can be determined as appropriate. For example, the non-stretchable region 70 may be provided from a region overlapping the absorbent body 13 to a region located in the width direction WD or the front-rear direction LD and not overlapping the absorbent body 13 . 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 shape of each joint 40 in the non-stretchable region 70 is not particularly limited, and can be appropriately selected from shapes similar to those described in the section on the stretchable region 80 .

In addition, the area ratio of the joints 40 in the non-stretchable region and the area of the individual joints 40 can be determined as appropriate. It is preferable because the non-stretchable region 70 does not become hard due to the low area ratio of 40 .
Area of joint 40: 0.10 to 0.75 mm ² (especially 0.10 to 0.35 mm ² )
Area ratio of joint 40: 4 to 13% (especially 5 to 10%)

The non-stretchable region 70 can be formed by densely arranging the joints 40 so that the first sheet layer 20A and the second sheet layer 20B are not shrunk by the contractile force of the elastic sheet 30 and folds are not formed. . As a specific example of the method of forming the non-stretchable region 70, for example, the method described in Patent Document 3 can be cited. 16 and 17 show an example of the non-stretchable region 70 described in Patent Document 3. FIG. In the non-stretchable region 70, the joint holes 31 are arranged in a zigzag pattern more densely than a certain degree, and although the elastic sheet 30 is continuous in the stretch direction ED, due to the presence of the joint holes 31, the joint holes 31 linearly extend along the stretch direction ED. It does not have continuous parts. In this case, as shown in FIGS. 16 and 17, the vent holes 33 (gap) are opened with substantially the same size in both the natural length state and the unfolded state.

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

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

When the first sheet layer 20A and the second sheet layer 20B are joined through the joint hole 31 of the elastic sheet 30 at the joining portion 40, the joining portion 40 is formed by material welding. A first welding mode in which the first sheet layer 20A and the second sheet layer 20B are joined only by a melted and solidified material 20m of at least one of at least one of the second sheet layer 20A and the second sheet layer 20B (see FIG. 18(a)) , a second welding mode in which the first sheet layer 20A and the second sheet layer 20B are joined only by the melted and solidified material 30m of the elastic sheet 30 in the joining portion 40 (see FIG. 18B). , and a third welding mode (see FIG. 18(c)) in which both of these are combined, but the second and third welding modes are preferable.

Particularly preferably, the first sheet layer 20A is formed by the melted and solidified material 20m of a part of the first sheet layer 20A and the second sheet layer 20B and the melted and solidified material 30m of all or most of the elastic sheet 30 at the joint 40. and the second sheet layer 20B are joined. In addition, in the third welding mode shown in FIG. 20(b), 30m of the melted and solidified material of the elastic sheet 30 can be seen between 20m of the melted and solidified material of the fibers of the first sheet layer 20A or the second sheet layer 20B. On the other hand, in the first welding mode shown in FIG. 20(a), the melted and solidified material of the elastic sheet 30 is not seen between the melted and solidified materials 20m of the fibers of the first sheet layer 20A or the second sheet layer 20B.

As in the first welding mode and the third welding mode, the first sheet layer 20A and the first sheet layer 20A and the first sheet layer 20B and the first sheet layer 20A and the second sheet layer 20B are melted and solidified 20m of at least one of them. When joining the second sheet layer 20B, it is preferable that a part of the first sheet layer 20A and the second sheet layer 20B is not melted so that the joined portion 40 is not hardened.

When the first sheet layer 20A and the second sheet layer 20B are made of nonwoven fabric, the core (composite) of all the fibers of the joint portion 40 must be partially melted. Including not only the core of the fiber but also the central part of the monocomponent fiber) remains, but the surrounding part (including not only the sheath of the composite fiber but also the surface layer of the monocomponent fiber) is melted, and some fibers does not melt at all, but the rest of the fiber melts entirely, or the core remains but its surrounding portion melts.

In the second welding mode and the third welding mode, when the first sheet layer 20A and the second sheet layer 20B are nonwoven fabrics, the melted and solidified material 30m of the elastic sheet 30 is bonded to the joint 40 as shown in FIG. 19(c). It may penetrate between the fibers throughout the thickness direction of the first sheet layer 20A and the second sheet layer 20B in FIG. As shown in 19(b), the flexibility of the joint 40 is higher in the form in which the fibers hardly permeate between the fibers of the first sheet layer 20A and the second sheet layer 20B.

(Convex area and concave area)
As shown in FIGS. 1, 2, and 8, the tubular leg portion 50 has convex regions 55 and concave regions 57 that are alternately and repeatedly provided adjacent to each other in the leg length direction orthogonal to the circumferential direction. The circumferential direction of the leg tube portion 50 is parallel to the edge 29 of the leg opening. In the illustrated example, the leg length direction is the front-rear direction LD at the end portion on the side seal portion 21 side, and the width direction WD at the narrowest portion of the exterior body 20 . Here, the convex region 55 and the concave region 57 are the stretchable region 80 having the elastic sheet stretchable structure 20X. In other words, the first sheet layer 20A and the second sheet layer 20B in each region contract in the elastic direction (the width direction WD in the example shown in FIG. 2) together with the elastic sheet 30 in the natural length and in the state of being contracted to some extent. It has folds 25 (see FIG. 13(c)) formed by swelling in opposite directions . Further, the distance 40d in the stretching direction ED of the joint 40 is wider in the convex region 55 than in the concave region 57, and in the convex region 55 and the concave region 57, the dimensions 55L and 57L in the leg length direction are constant regions, respectively. The dimension 55L of the convex region 55 in the leg length direction is less than or equal to the dimension 57L of the concave region 57 in the leg length direction.

In such a leg tube 50 , at least in the wearing state (for example, in a state of being stretched to half of the maximum stretch in the stretching direction), the convex region 55 is formed with a large fold 25 that is higher than the concave region 57 . Therefore, as shown in FIG. 10, one of the convex regions 55 and the concave regions 57 is relatively convex due to the difference in thickness (difference in maximum elongation) due to the folds 25 in the contracted state, and the other is relatively concave. It is. With such a convex region 55 and a concave region 57, as indicated by the two-dot chain line in the figure, when the wearer turns over the leg tube portion 50 and stacks it in a double layer or the like as necessary, the The convex region 55 and the concave region 57 can be meshed between the folded portion and the folded portion 50r. Therefore, tightening pressure can be increased while suppressing an increase in thickness. Moreover, although this was not originally expected, the meshing of the convex region 55 and the concave region 57 also brings about the advantage that the turned-up portion is less likely to shift.

When the projecting region 55 and the recessed region 57 are used as the stretchable region 80, the elastic sheet stretchable structure 20X can be configured by separate members in the projecting region 55 and the recessed region 57. As shown in the example, when the stretchable region 80 having the single elastic sheet stretchable structure 20X is provided with the convex region 55 and the concave region 57 having different stretchability due to different arrangement patterns of the joints 40, the leg length increases. It is preferable because the fit of the tubular leg portion 50 is improved without breaking the stretchability in the longitudinal direction.

As long as the convex region 55 shrinks together with the elastic sheet 30 in the concave region 57 to form the folds 25, the convex region 55 does not need to be provided with the elastic sheet 30 or have the joining portion 40. . For example, as in the example shown in FIG. 12, the narrow elastic sheet 30 forming the recessed region 57 is moved from one side seal portion 21 along the edge 29 of the leg opening toward the center in the width direction WD, and A plurality of them may be attached in parallel in a pattern that traverses the center of the WD toward the other leg opening LO and extends along the edge 29 of the other leg opening to the other side seal portion 21 . In this case, the direction of expansion and contraction is the direction in which the elastic sheet 30 is attached, and therefore the direction of expansion and contraction is the circumferential direction of the tubular leg portion 50 in the portion where the direction of attachment of the elastic sheet 30 is along the edge 29 of the leg opening.

The convex region 55 and the concave region 57 preferably form an annular shape continuously in the circumferential direction of the tubular leg portion 50, but may be intermittently provided in the circumferential direction as shown in FIG. In the illustrated example, the convex region 55 and the concave region 57 are provided (the stretchable region 80 is provided) only outside the narrowest portion of the exterior body 20 in the width direction WD. Instead, the exterior body 20 may have a portion where the convex region 55 and the concave region 57 are not provided on the outer side in the width direction WD of the narrowest portion.

The convex regions 55 and the concave regions 57 are provided alternately and repeatedly while being adjacent to each other in the leg length direction. Although not shown, the convex regions 55 and the concave regions 57 can be alternately and repeatedly provided in the circumferential direction at the same position in the leg length direction as long as they can be matched (that is, the convex regions 55 and the concave regions 57 are arranged in a checkered pattern). Become). In this case, the turned-up portion of the tubular leg portion 50 is less likely to move in the circumferential direction, but the tightening force in the circumferential direction changes. On the other hand, as in the illustrated example, only one of the convex region 55 and the concave region 57 is provided at the same position in the leg length direction (horizontal stripes are formed by the convex region 55 and the concave region 57). , uniform tightening can be achieved in the circumferential direction. In the latter case, if the end of the tubular leg portion 50 on the side of the leg opening LO is provided with a convex region 55 as in the illustrated example, the end on the side of the leg opening LO can be firmly tightened. At the same time, the minimum turn-up length required for meshing the convex region 55 and the concave region 57 can be shortened, and the tightening force can be adjusted in a wider range, which is preferable.

The dimension 55L of the convex region 55 in the leg length direction can be determined appropriately as long as it is equal to or smaller than the dimension 57L of the concave region 57 in the leg length direction. It is preferably smaller than the leg length dimension 57L. Further, specific dimensions can be determined as appropriate. For example, in a normal case, the dimension 55L of the convex region 55 in the leg length direction can be about 5 to 10 mm, and the dimension 57L of the concave region 57 in the leg length direction can be about 5 to 10 mm. It can be about 3 to 8 mm.

When the convex region 55 and the concave region 57 have the elastic sheet 30, one is convex and the other is concave due to the difference in maximum elongation. Therefore, the maximum elongation of the convex region 55 and the concave region 57 may be appropriately adjusted according to the degree of meshing desired for the convex region 55 and the concave region 57. Preferably, the elongation is 200-350%, and the maximum elongation of the concave regions 57 in the direction of stretching is 0.70-0.95 times the maximum elongation of the convex regions 55 in the direction of stretching .

(Front and rear presser sheet)
As shown in FIGS. 1 and 4, a pressing sheet 60 is provided to cover the front and rear ends of the inner body 10 mounted on the inner surface of the outer body 20 and to prevent leakage from the front and rear edges of the inner body 10. may be provided. To explain the illustrated embodiment in more detail, the pressing sheet 60 extends across the entire width direction from the inner surface of the folded portion 20C of the inner surface of the front body F to a position overlapping the front end portion of the inner body 10, and the inner surface of the back body B. It extends over the entire width direction from the inner surface of the folded portion 20</b>C to a position overlapping the rear end portion of the inner body 10 . Attaching the pressing sheet 60 separately as in the illustrated embodiment has the advantage of increasing the degree of freedom in material selection, but also has the disadvantage of increasing the number of materials and manufacturing processes. Therefore, the folded portion 20</b>C can be extended to a portion overlapping the inner body 10 to form a portion equivalent to the pressing sheet 60 .

(inner body joint)
As shown in an enlarged view in FIG. 10, when the inner body joint portion 18, which is the joint region between the outer body 20 and the inner body 10, is arranged in the non-stretchable region 70 provided in the portion overlapping the absorbent body 13, This is preferable because the inner body 10 is less likely to contract in the width direction WD together with the stretchable region 80 and the fit is less likely to deteriorate.

<Others>
As the nonwoven fabric in the above description, a known nonwoven fabric can be appropriately used depending on the site and purpose. Constituent fibers of non-woven fabrics include, for example, synthetic fibers such as olefin-based, polyester-based, and polyamide-based fibers such as polyethylene or polypropylene (including composite fibers such as core-sheath fibers in addition to single-component fibers), as well as recycled rayon and cupra. Fibers, natural fibers such as cotton, etc., can be selected without particular limitation, and these can also be mixed and used. In order to increase the softness of the nonwoven fabric, it is preferable to use crimped fibers as the constituent fibers. In addition, even if the constituent fibers of the nonwoven fabric are hydrophilic fibers (including those made hydrophilic by a hydrophilic agent), they may be hydrophobic fibers or water-repellent fibers (water-repellent fibers made water-repellent by a water-repellent agent). including). In addition, nonwoven fabrics are generally classified into short fiber nonwoven fabrics, long fiber nonwoven fabrics, spunbond nonwoven fabrics, meltblown nonwoven fabrics, spunlace nonwoven fabrics, thermal bonded (air-through) nonwoven fabrics, and needle punched nonwoven fabrics, depending on the fiber length, sheet forming method, fiber bonding method, and laminate structure. Nonwoven fabrics are classified into nonwoven fabrics, point-bonded nonwoven fabrics, laminated nonwoven fabrics (such as SMS nonwoven fabrics and SMMS nonwoven fabrics in which a meltblown layer is sandwiched between spunbond layers), and any of these nonwoven fabrics can be used.

<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.

・"MD direction" and "CD direction" mean the flow direction (MD direction) and the transverse direction (CD direction) perpendicular to this in the manufacturing equipment, and one of them is the front-back direction depending on the part of the product and the other is the width direction. The MD direction of a nonwoven fabric is the direction of fiber orientation of the nonwoven fabric.

- "Front side" means the side closer to the wearer's skin when worn, and "back side" means the side farther from the wearer's skin when worn.

"Front" means the side of the member that is closer to the wearer's skin when worn, and "back" means the side of the member that is farther from the wearer's skin when worn. .
- "Front body" and "rear body" refer to the front and rear portions of the disposable diaper, respectively, with respect to the center in the front-rear direction.
・"Crotch part" means the part that is to be positioned between the crotch of the wearer, and normally, as shown in FIG. It means the range in the front-rear direction in which the acute crossing angle with the direction is 45° or less.

- "Maximum elongation" means the maximum value of elongation in the stretching direction ED (in other words, the elongation in the unfolded state in which the first sheet layer and the second sheet layer are flatly unfolded without shrinkage or slack). The length is expressed as a percentage when the natural length is taken as 100%.

- "Area ratio" means the ratio of the target portion to the unit area, and the target portion (for example, the joint 40, the opening of the joint hole 31, the ventilation hole) in the target region (for example, the stretchable region 80, the non-stretchable region 70) is expressed as a percentage by dividing the total area of by the area of the target region. In particular, the "area ratio" in the area having an elastic structure means the area ratio in the unfolded state. In a form in which a large number of target portions are provided at intervals, it is desirable to determine the area ratio by setting the target region to a size that includes 10 or more target portions.

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

- "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 .

・The direction of "fiber orientation of nonwoven fabric" is the direction along which the fibers of the nonwoven fabric are aligned. It can be determined by a simple measurement method that determines the fiber orientation direction from the tensile strength ratio of the direction.

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

・Unless otherwise specified, the dimensions and positional relationships of each part refer to the dimensions in the unfolded state, not in the natural length state.

・If there is no description about environmental conditions for testing and measurement, the test and measurement shall be performed in a laboratory or equipment under standard conditions (test location: temperature 23±1°C, relative humidity 50±2%). do.

INDUSTRIAL APPLICABILITY The present invention can be used for trunks-type disposable diapers such as those described above.

B... Back body, BS... Three-dimensional gathers, C1... Intersection position, F... Front body, LD... Front-back direction, LO... Leg opening, ED... Elastic direction, WD... Width direction, XD... Orthogonal direction, WO... Waist opening, Sheet... Front and back presser 10... Inner body 11... Top sheet 12... Liquid-impermeable sheet 13... Absorbent body 13N... Constricted part 14... Packaging sheet 15... Gather sheet 16... Gather elastic member 17 Diffusion groove 18 Inner body joint portion 20 Outer body 20A First sheet layer 20B Second sheet layer 20C Folded portion 20X Elastic sheet expansion structure 21 Side seal portion 22 Intermediate region 24 Waist elastic member 25 Folds 26 Waist elastic member 28 Crotch portion 29 Edge of leg opening 30 Elastic sheet 40 Joining portion 50 Leg tube portion 51 Inner thigh contact portion 55... Convex area 57... Concave area 70... Non-stretchable area 80... Stretchable area.

Claims (5)

Equipped with a pair of leg cylinders surrounding the root side of the thigh,
In the leg cylinder, convex regions and concave regions are alternately and repeatedly provided adjacent to each other in a leg length direction orthogonal to the circumferential direction,
The convex region and the concave region are regions where the first sheet layer and the second sheet layer are overlapped,
The convex region has a joint portion between the first sheet layer and the second sheet layer where the first sheet layer and the second sheet layer are not joined or a space is provided between the first sheet layer and the second sheet layer. ,
the recessed region has a joint portion of the first sheet layer and the second sheet layer spaced apart;
an elastic sheet is provided between the first sheet layer and the second sheet layer at least in the recessed area;
The first sheet layer and the second sheet layer in the convex region and the concave region have folds formed by contracting in the stretching direction together with the elastic sheet and expanding in directions opposite to each other,
The convex region has a wider interval in the expansion and contraction direction of the joint than the concave region,
The convex region and the concave region each have a constant dimension in the leg length direction,
The dimension of the convex region in the leg length direction is equal to or less than the dimension of the concave region in the leg length direction,
A trunks-type disposable wearing article characterized by: The elastic sheet is provided in the convex region and the concave region,
An arrangement pattern of the joints in the convex region and an arrangement pattern of the joints in the concave region are different,
The trunks-type disposable wearing article according to claim 1. Only one of the convex region and the concave region is provided at the same position in the leg length direction,
The convex region is provided at the end of the leg cylinder on the leg opening side,
The trunks-type disposable wearing article according to claim 2. The maximum elongation of the convex regions in the direction of stretching is 200 to 350%, and the maximum elongation of the concave regions in the direction of stretching is 0.70 to 0.95 times the maximum elongation of the convex regions in the direction of stretching. be,
The trunks-type disposable wearing article according to claim 2 or 3. an exterior body having a waist opening and a pair of leg openings and extending from the edge of the waist opening on the front side to the edge of the waist opening on the rear side; a side seal portion that joins both front side portions and rear side portions of the exterior body,
An annular waist portion is formed between one side seal portion and the other side seal portion in the width direction of the exterior body,
The crotch portion of the exterior body has a pair of inner thigh contact portions extending outward in the width direction from both side edges of the absorbent body, and a portion along the edge of the leg opening including these inner thigh contact portions. is the leg cylinder,
In the outer body, a region extending from the leg tube portion to at least one of the front and rear waist portions is a region having the first sheet layer, the second sheet layer, and the elastic sheet.
The trunks-type disposable wearing article according to any one of claims 1 to 4.