JP5691705B2 - Disposable diapers - Google Patents

Description

  The present invention relates to a disposable diaper that is attached to a wearer's crotch and absorbs and holds a liquid such as urine.

  Conventionally, a disposable diaper including a liquid-permeable top sheet, a liquid-impermeable back sheet, and an absorber interposed between these sheets is known. Moreover, the general disposable diaper is equipped with a pair of three-dimensional gathers which stand along the both-sides edge part of an absorber. The three-dimensional gather functions as a leak-proof wall for preventing a liquid from leaking outside when a liquid such as urine is received by a disposable diaper.

  More specifically, the three-dimensional gather stands up along the side edges of the absorber so as to come into contact with the skin of the wearer, and can be absorbed by the liquid that has not permeated the top sheet or the absorber. The liquid that has not been leaked is prevented from leaking from the opening of the disposable diaper. In such a three-dimensional gather, generally, an elastic elastic member in an extended state is disposed along the longitudinal direction of the three-dimensional gather. For this reason, a three-dimensional gather stands up in the direction which touches a wearer's skin using the contractive force at the time of an elastic elastic member contracting.

  Here, in a general three-dimensional gather, a thin thread-like elastic elastic member is linearly disposed along the upper edge of the three-dimensional gather, for example, as a disposable diaper disclosed in Patent Document 1. Thus, by arranging the elastic elastic members linearly along the upper edge of the three-dimensional gather, the shape of the three-dimensional gather when standing can be maintained.

JP 2000-271169 A JP 2007-209518 A

  However, as described above, the upper edge of the three-dimensional gather is also a part that touches the wearer's skin. An elastic elastic member such as a rubber thread has a certain degree of hardness. Accordingly, when the elastic stretchable member is disposed along the upper edge of the three-dimensional gather, the hard elastic stretchable portion continues to rub against the wearer's skin. For this reason, for example, on the skin of a wearer who has been wearing a disposable diaper for a long time, a situation has occurred in which a scratch remains on a portion of the skin that is in contact with the upper edge of the three-dimensional gather. In particular, since the skin of infants is soft and easily damaged, scratches after using disposable diapers were remarkable.

  In order to eliminate such a situation, it has been proposed to dispose the elastic elastic member at a position slightly shifted downward from the upper edge of the three-dimensional gather, such as a disposable diaper disclosed in Patent Document 2. ing. However, if the elastic elastic member is arranged at a position slightly shifted downward from the upper edge of the three-dimensional gather, a gap is formed between the upper edge of the three-dimensional gather and the elastic elastic member, and the sheet forming the three-dimensional gather is bent. It will be. As described above, when the three-dimensional gather is bent, not only the degree of adhesion between the three-dimensional gather and the wearer's skin is lowered, but also the shape of the three-dimensional gather at the time of standing cannot be maintained. Therefore, the original function of the three-dimensional gather, which improves the leak-proof property of the disposable diaper, is impaired.

  For this reason, at present, there is a demand for a disposable diaper that can maintain the leak-proof property while preventing the wearer's skin from being damaged by increasing the flexibility at the upper edge of the three-dimensional gather.

Accordingly, the inventors of the present invention have intensively studied the means for solving the problems of the above-described conventional invention. It was found that the upper edge of the gather was more flexible and the upper edge of the three-dimensional gather could be moved flexibly according to the unevenness and curvature of the wearer's body. The inventor has conceived that the problems of the prior art can be solved based on the above knowledge, and has completed the present invention.
Specifically, the present invention has the following configuration.

The present invention relates to a liquid-permeable top sheet 1, a liquid-impermeable back sheet 2, an absorbent body 3 interposed between these sheets, and a three-dimensional gather that stands along both side edges of the absorbent body 3. The present invention relates to a disposable diaper including four.
In the three-dimensional gather 4, the side sheet 40 that forms the three-dimensional gather 4 is folded back at a folding portion 41 corresponding to the upper end edge of the three-dimensional gather 4.
Between the side sheets 40 folded at the folded portion 41, an elastic elastic member 42 is disposed in an extended state along the longitudinal direction of the three-dimensional gather 4.
In the stretched state of the elastic elastic member 42, a plurality of gaps 421 extending in the short direction of the elastic elastic member 42 are formed in the longitudinal direction of the elastic elastic member 42.
In the contracted state, the elastic stretchable member 42 has a narrower gap 421 extending in the short direction of the three-dimensional gather 4 than in the stretched state of the elastic stretchable member 42.
Thereby, it is preferable that a plurality of darts 423 are formed on the upper end edge of the three-dimensional gather 4 in a state where the elastic elastic member 42 is contracted.

  In other words, the gap 421 formed in the elastic elastic body 42 in the expanded state becomes narrow when the elastic elastic member contracts, so that the side sheet 40 that forms the upper end portion of the three-dimensional gather 4 becomes the elastic elastic member 42. It is picked in between to form darts (folds). Thus, since the upper end edge of the three-dimensional gather 4 becomes flexible by forming the dart, it is possible to prevent a situation in which the wearer's skin is damaged. In addition, since the dart 423 is formed, the degree of adhesion between the three-dimensional gather and the wearer's skin can be increased, so that the leakproof property of the disposable diaper can be increased.

  In a preferred embodiment of the present invention, the elastic elastic member 42 has a cut 422 formed in the contracted state from the upper edge of the elastic elastic member 42 to the middle in the short direction of the elastic elastic member 42. Are formed in the longitudinal direction. As a result, in the stretched state of the elastic elastic member 42, the cut 422 is opened, and a gap 421 extending in the short direction of the elastic elastic member 42 is formed.

  Thus, by providing the cut 422 in the elastic elastic member 42 in the contracted state, the gap 421 can be formed in the elastic elastic member 42 in the extended state. Accordingly, in the contracted state, the gap of the elastic member 42 is eliminated or becomes extremely narrow. Thereby, since the bending width of the 3rd sheet | seat 40 which forms the three-dimensional gather 4 becomes large, the bigger dart 423 is formed. In addition, since the elastic stretch member 42 has a plurality of cuts 422 formed from the upper end to the middle, a strip 424 is formed between the cuts 422 in the upper part where the cuts 422 are formed. Each strip 424 can move freely according to the unevenness and curvature of the wearer's body. Thus, since the larger dart 423 and the strip part 424 are formed, the upper end edge of the three-dimensional gather 4 becomes flexible, and the degree of close contact between the three-dimensional gather 4 and the wearer's skin also increases.

  In a preferred embodiment of the present invention, the elastic elastic member 42 is joined between the side sheets 40 so that the upper edge of the cut 422 is in contact with the folded portion 41 of the side sheet 40.

  Thus, the elastic elastic member 42 is disposed at the upper end edge of the three-dimensional gather 4, so that the shape of the three-dimensional gather 4 when standing can be maintained. Furthermore, since the notch 422 is formed in the upper edge side of the elastic elastic member 42, it is flexible and does not damage the wearer's skin.

  Further, according to the present invention, between the side sheets 40 folded at the folded portion 41, the elastic elastic member 42 is a convex curve portion that swings in the width direction of the three-dimensional gather 4 along the longitudinal direction of the three-dimensional gather 4. 426 and the concave curved portion 427 may be arranged in a continuous wave shape. In this case, the elastic elastic member 42 is formed with a gap 421 between the convex curved portions 426 and the concave curved portions 427 that are wavy in the extended state. In the contracted state, the elastic stretchable member 42 has a narrower gap 421 than in the stretched state of the elastic stretchable member 42.

  That is, even when such a wave-like elastic elastic member 42 is disposed in the vicinity of the upper end edge of the three-dimensional gather 4, darts are formed on the upper end edge of the three-dimensional gather 4 when the elastic elastic member 42 contracts. It is formed. Therefore, since the softness | flexibility in the upper end edge of the three-dimensional gather 4 increases, the situation where a wearer's skin is damaged can be prevented and the leak-proof property of a disposable diaper can also be maintained.

FIG. 1 is a developed view of a disposable diaper, showing a state viewed from the top sheet side. FIG. 2 is a schematic cross-sectional view showing an example of a cross-sectional shape when the disposable diaper shown in FIG. 1 is cut along the line AA. FIG. 3 is an enlarged schematic perspective view showing a part near the upper end edge of the three-dimensional gather in a state where the elastic elastic member is extended. FIG. 4 is an enlarged schematic perspective view showing a part near the upper end edge of the three-dimensional gather in a state where the elastic elastic member is contracted. FIG. 5 is a schematic diagram for explaining a process of manufacturing a three-dimensional gather, and the manufacturing process is divided into processes (a) to (e). FIG. 6 is a schematic perspective view showing a part near the upper edge of the three-dimensional gather in an expanded state of the elastic elastic member. FIG. 7 is an enlarged schematic perspective view showing a part near the upper edge of the three-dimensional gather in a state where the elastic elastic member is contracted.

  Hereinafter, embodiments for carrying out the present invention will be described with reference to the drawings. The present invention is not limited to the embodiments described below, but includes those appropriately modified by those skilled in the art from the following embodiments.

(1. Overall configuration of disposable diapers)
The present invention can be applied to the disposable diaper 10. Specifically, the disposable diaper 10 includes a liquid-permeable top sheet 1, a liquid-impermeable back sheet 2, an absorber 3 interposed between the top sheet 1 and the back sheet 2, and the top sheet 1. And a pair of three-dimensional gathers 4 standing along both edges of the absorbent body 3. In the disposable diaper 10, the liquid that has passed through the top sheet 1 is absorbed and held by the absorbent body 3 disposed between the top sheet 1 and the back sheet 2. Moreover, in the disposable diaper 10, when the liquid is received, the side leakage of the liquid is prevented by the three-dimensional gathers 4 standing along the both side edges of the absorber 3.
The present invention only needs to have such a configuration, and is applied to, for example, a pants-type diaper, a tape-type diaper, and a urine removing pad.

  FIG. 1 is a development view of a disposable diaper 10 applied to a pants-type disposable diaper, and shows a state viewed from the top sheet 1 side. As shown in FIG. 1, the disposable diaper 10 includes a front body 51 that covers the wearer's abdomen when worn, a back body 52 that covers the wearer's back when worn, and a crotch that is applied to the inseam of the wearer when worn. Part 53 is included. Then, by joining the end portions of the side flaps 54 extending to both side edges of the front body 51 and the back body 52 so as to correspond to each other, a waist opening located around the waist of the wearer when worn, and a crotch 53 The leg opening around the leg of the wearer is formed at the time of wearing. For example, in the case where the disposable diaper 10 is a pants-type disposable diaper, the wearer puts both legs into the waist opening so that the front body 51 is located on the abdomen and the back body 52 is located on the back. A disposable diaper is worn by taking out the part from the opening around the leg.

(2. Specific configuration of disposable diapers)
Hereinafter, with reference to FIG. 2, the specific structure of the disposable diaper which concerns on this invention is demonstrated. FIG. 2 shows an example of a cross-sectional shape when the disposable diaper shown in FIG. 1 is cut along the line AA.

(2-1. Top sheet)
The top sheet 1 is a member that is in direct contact with the skin of the wearer's crotch and allows liquid such as urine to pass through the absorber 3. For this reason, it is preferable that the top sheet 1 is made of a liquid-permeable material having high flexibility. As shown in FIG. 2, the top sheet 1 is disposed so as to cover the surface of the absorbent body 3 (the surface that comes into contact with the skin of the wearer).

  The example of the impermeable material which comprises the top sheet 1 is a woven fabric, a nonwoven fabric, or a porous film. The top sheet 1 may be made of a nonwoven fabric obtained by hydrophilizing fibers of thermoplastic resin such as polypropylene, polyethylene, polyester, and nylon.

(2-2. Backsheet)
The back sheet 2 is a member for preventing the liquid that has passed through the top sheet 1 and absorbed by the absorber 3 from leaking out. For this reason, the backsheet 2 is made of a liquid-impermeable material. Then, as shown in FIG. 2, the back sheet 2 covers the bottom surface of the absorber 3 in order to prevent liquid leakage from the bottom surface of the absorber 3 (the surface opposite to the surface in contact with the wearer's skin). To be arranged.

An example of the impermeable material constituting the back sheet 2 is a liquid impermeable film made of polyethylene resin. In particular, it is preferable to use a microporous polyethylene film in which a plurality of fine pores of 0.1 to 4 μm or 2 to 3 μm are formed because air permeability can be imparted.
In the present specification, “A to B” means “A or more and B or less”.

  A cover sheet 55 may be bonded to the outer surface of the back sheet 2 in order to reinforce the back sheet 2 and improve its feel. As a material constituting the cover sheet 55, a woven fabric or a non-woven fabric is used. In particular, it is preferable to use a nonwoven fabric or a wet nonwoven fabric made of a thermoplastic resin such as polyethylene, polypropylene, or polyester as a material constituting the cover sheet 55.

(2-3. Absorber)
The absorber 3 is a member for absorbing liquid such as urine and holding the absorbed liquid. The absorber 3 is disposed between the liquid-permeable top sheet 1 and the liquid-impermeable back sheet 2. The absorber 3 has a function of absorbing and holding the liquid that has passed through the top sheet, and is made of an absorbent material.

  A known material can be adopted as the absorbent material constituting the absorber 3. As the absorbent material, for example, flap pulp, superabsorbent polymer, or hydrophilic sheet may be used. In addition, as the absorbent material, one kind of flap pulp, superabsorbent polymer, or hydrophilic sheet may be used alone, or two or more kinds may be used in combination. The absorbent material is usually formed and used in a single-layer or multi-layer mat shape.

  Moreover, it is preferable that the absorber 3 is clamped by at least a part between the top sheet 1 and the back sheet 2. The absorber 3 is sandwiched between the top sheet 1 and the back sheet 2 and is fixed between the top sheet 1 and the back sheet 2 by sealing the peripheral edge thereof.

  The shape of the absorber 3 can be appropriately designed according to the shape, size, and use of the disposable diaper. For example, the shape of the absorber 3 may be an hourglass shape as shown in FIG. The shape of the absorber 3 may be a rectangular shape, an elliptical shape, or a gourd shape.

(2-4. Solid gathers)
The three-dimensional gather 4 is a member that stands along both side edges of the absorber 3 and prevents side leakage of urine excreted by the wearer. The three-dimensional gather 4 is a urine leakage-preventing wall in a standing state (a state in which the elastic elastic member disposed at the upper edge is contracted). Prevents side leakage from the urine that has been squeezed out from the openings around the legs of the absorber. A pair of solid gathers 4 may be formed on both side edges of the absorbent body, or two or more pairs may be formed.

  Each of the three-dimensional gathers 4 has a fixing line 43 that is fixed to the side edge of the top sheet 1. For example, as shown in FIG. 2, the pair of three-dimensional gathers 4 may be fixed to the top sheet 1 and the back sheet 2 so as to sandwich both side edges of the top sheet 1 and the back sheet 2. Further, each of the three-dimensional gathers is formed by a side sheet 40 made of, for example, a nonwoven fabric. And the side sheet | seat 40 which forms the three-dimensional gather 4 is good also as being comprised as a different body from the top sheet | seat 1 and the back sheet | seat 2. FIG.

  In this way, the three-dimensional gather 4 is fixed to the top sheet 1 at the fixing line 43 by an adhesive or other bonding means. The three-dimensional gather 4 and the top sheet 1 may be fixed by, for example, a fixing method using a hot melt adhesive or other fluid adhesive, or fixed by heat welding such as heat sealing or ultrasonic welding. May be.

  As the side sheet 40 constituting the three-dimensional gather 4, it is preferable to use a hydrophobic material. As an example of the hydrophobic material, it is preferable to use a nonwoven fabric such as spunbond or card emboss from the viewpoint of high hydrophobicity and good air permeability. In particular, it is preferable to use a clogged nonwoven fabric such as SMS (spunbond / meltblown / spunbond) or SMMS (spunbond / meltblown / meltblown / spunbond) because of its high water pressure resistance.

  As shown in FIG. 2, the three-dimensional gather 4 rising at the fixed line 43 has its side sheet 40 in the folded portion 41 corresponding to the upper end edge of the three-dimensional gather 4 toward the direction in which the absorber 3 exists. Wrapped. For this reason, the side sheet 40 which forms the three-dimensional gather 4 has overlapped with the thickness direction (left-right direction in FIG. 2) of the three-dimensional gather 4 in the part folded in the folding | returning part 41. FIG. In addition, the side sheet | seat 40 which forms the three-dimensional gather 4 may be folded in the folding | returning part 41 toward the outward (direction where the absorber 3 does not exist) of a disposable diaper.

  As shown in FIG. 2, one or a plurality of elastic elastic members 42 are disposed in an extended state along the longitudinal direction of the three-dimensional gather 4 between the side sheets 40 folded at the folding portion 41. For this reason, the three-dimensional gather 4 stands by using the contraction force when the elastic expansion / contraction member 42 contracts. In the embodiment shown in FIG. 2, one planar elastic stretchable member 42 having a predetermined width is disposed. That is, since the elastic elastic member 42 is fixed to the three-dimensional gather 4 between the side sheets 40 in an extended state, when the elastic elastic member 42 contracts, the side sheet 40 of the three-dimensional gather 4 also contracts, and the three-dimensional gather 4 Rises from the fixed line 43 with the top sheet 1 as a starting point.

  The position at which the elastic elastic member 42 is disposed in the three-dimensional gather 4 can be appropriately changed according to the shape and size of the disposable diaper 10, but is preferably disposed at or near the upper edge of the three-dimensional gather 4. . Here, the vicinity of the upper end edge of the three-dimensional gather 4 is, for example, an upper region when the distance from the fixed line 43 of the three-dimensional gather 4 to the upper end edge is halved, and is divided into ３. In this case, the uppermost area may be the uppermost area when the area is divided into 1/5, or the uppermost area when the area is divided into 1/6.

  In this way, the three-dimensional gather 4 rises in a direction (upward direction in FIG. 2) in contact with the wearer's skin, starting from the fixing line 43 with the top sheet 1. Thereby, an upright portion from the fixed line 43 to the upper end edge is formed in the three-dimensional gather 4. In FIG. 2, an example in which the standing part of the three-dimensional gather 4 tilts in the direction in which the absorber 3 exists is shown. However, the standing part of the three-dimensional gather 4 may be, for example, a form that tilts toward the outside of the absorbent body 3, or a curved part or a broken line may be formed on a part of the standing part. Good. The length of the upright portion of the three-dimensional gather 4 (the length from the fixed line 43 to the upper edge) is, for example, 10 mm to 100 mm, or 20 mm to 80 mm, preferably 30 mm to 60 mm.

(3. Specific configuration of elastic elastic member: first embodiment)
FIG. 3 is an enlarged schematic perspective view showing a part near the upper edge of the three-dimensional gather 4 in a state where the elastic elastic member 42 is extended. In FIG. 3, the elastic elastic member 42 sandwiched between the side sheets 40 is transparently represented by a broken line.

  In the embodiment shown in FIG. 3, a sheet-like elastic elastic member 42 (flat rubber) having a predetermined length, width, and thickness is used. As shown in FIG. 3, the elastic elastic member 42 in the extended state is formed with gaps 421 (notches) at regular intervals along the upper edge side. The gap 421 is formed from the upper end edge to the middle of the elastic expansion / contraction member 42 in the short direction perpendicular to the longitudinal direction of the elastic expansion / contraction member 42. By providing a plurality of gaps 421 up to the middle of the elastic stretchable member 42, strip portions 424 are formed between the gaps 421, and the base portion of each strip portion 424 is a continuous portion 425 of the elastic stretchable member 42. Connected by As will be described later, the gap 421 formed along the upper end edge side of the elastic elastic member 42 in the expanded state is formed by opening a notch 422 formed from the upper edge of the elastic elastic member 42 in the contracted state to the middle. It is.

  The elastic elastic member 42 is joined between the side sheets 40 forming the three-dimensional gather 4 in the extended state (the state where the notch 422 is opened and the gap 421 is generated). That is, the strip portion 424 and the continuous portion 425 of the elastic elastic member 42 in the extended state are joined to the side sheet 40, and the side sheet 40 is not joined to the elastic elastic member 42 at a position corresponding to the gap 421. For example, a hot-melt adhesive or other fluid adhesive may be applied to both surfaces of the elastic elastic member 42 in an extended state, and bonded between the side sheets 40, for example, heat sealing The both sides of the elastic elastic member 42 in the stretched state and the side sheet 40 may be joined by heat welding or ultrasonic welding.

  Moreover, it is preferable that the elastic elastic member 42 in which the gap 421 is formed along the upper edge is joined between the side sheets 40 so that the upper edge contacts the folded portion 41 of the side sheet 40. . Even if the upper end edge of the elastic elastic member 42 is not in contact with the folded portion 41 of the side seat 40, the distance between the upper end edge of the elastic member 42 and the folded portion 41 is, for example, 0.1 mm to 5 mm, 0 .2 mm to 3 mm, 0.3 mm to 1 mm are preferable.

  FIG. 4 is an enlarged schematic perspective view showing a part near the upper edge of the three-dimensional gather 4 in a state where the elastic elastic member 42 is contracted. In FIG. 4 as well, the elastic elastic member 42 sandwiched between the side sheets 40 is transparently represented by a broken line. In particular, FIG. 4 shows a state in which the elastic elastic member 42 is contracted in the three-dimensional gather 4 in which the side sheet 40 is joined to the elastic elastic member 42 in an extended state in which a plurality of gaps 421 are formed along the upper edge. ing.

  That is, as shown in FIG. 4, when the elastic expansion / contraction member 42 contracts, the three-dimensional gather 4 rises and the gap 421 formed in the elastic expansion / contraction member 42 in the extended state disappears or becomes extremely narrow. Thereby, the part (part corresponding to the space | gap 421) of the side sheet 40 located between each strip part 424 of the elastic elastic member 42 in the expansion | extension state comes to bend. When the elastic expansion / contraction member 42 is in a contracted state (natural state) in which no tension is applied, a dart 423 (fold) is formed by the bent portion of the side seat 40 as shown in FIG. The dart 423 is formed at a position corresponding to the position of the gap 423 (cut 422) formed in the elastic elastic member 42. The dart 423 is formed so as to extend in the thickness direction of the three-dimensional gather 4. In FIG. 4, all the darts 423 are formed in the front direction in the figure, but the darts 423 formed in the depth direction in the figure may exist.

  As described above, when the elastic elastic member 42 contracts, the strip part 424 formed on the upper part of the elastic elastic member 42 is located at the lower part of the elastic elastic member 42 because the dart 423 formed on the three-dimensional gather 4 becomes a movement allowance. It can move with a high degree of freedom from the continuous part 425 as a base point. For this reason, when the elastic elastic member 42 is contracted (when the three-dimensional gather 4 is erected), the shape of the strip portion 424 that comes into contact with the wearer's skin changes flexibly according to the unevenness and curvature of the wearer's skin. .

  Further, as shown in FIG. 4, the elastic elastic member 42 preferably has no gap between the strips 424 formed on the upper end side in the contracted state. In order to form in this way, as will be described later, a plurality of cuts 422 may be formed from the upper end edge to the middle of the elastic stretchable member 42 in the stretched state, thereby forming the strip portion 424 in the elastic stretchable member 42. .

  Next, with reference to FIG. 5, the process of manufacturing the three-dimensional gather 4 of the disposable diaper 10 in 1st Embodiment is demonstrated. FIG. 5 is a schematic diagram for explaining a process of manufacturing the three-dimensional gather 4, and shows the manufacturing process divided into processes (a) to (e).

  FIG. 5A shows a flat rubber-like elastic elastic member 42 disposed near the upper edge of the three-dimensional gather 4. The flat rubber-like elastic elastic member 42 means an elastic elastic member 42 having a predetermined length, width, and thickness. The length of the elastic elastic member 42 at the time of contraction is, for example, 100 mm to 200 mm, 120 mm to 180 mm, and particularly preferably 140 mm to 150 mm. Moreover, the width | variety of the elastic expansion-contraction member 42 at the time of contraction is 5 mm-20 mm, 10 mm-15 mm, for example, It is preferable that it is especially 12 mm-13 mm. Moreover, the thickness of the elastic elastic member 42 at the time of contraction is 0.1 mm to 2 mm, 0.5 mm to 1.5 mm, and particularly preferably 0.9 mm to 1.1 mm. In addition, the length, width, and thickness of the elastic elastic member 42 described above can be appropriately changed according to the size and use of the disposable diaper 10.

  Further, as a material for forming the elastic elastic member 42, for example, styrene rubber, olefin rubber, urethane rubber, ester rubber, polyurethane, polyethylene, polystyrene, styrene butadiene, silicon, and polyester can be used. The expansion / contraction rate of the elastic expansion / contraction member 42 is, for example, 110% to 250%, 130% to 230%, and particularly preferably 150% to 200%. Moreover, the elastic strength of the elastic elastic member 42 is, for example, 50 g to 400 g, 70 g to 300 g, and preferably 100 g to 200 g.

  FIG. 5B shows the elastic elastic member 42 shown in FIG. 5A from the upper edge (the edge on the upper edge side of the three-dimensional gather 4) to the middle of the elastic elastic member 42 in the short direction. A state in which a plurality of cuts 422 are formed at regular intervals in the longitudinal direction of the elastic elastic member 42 is shown. This notch 422 is formed using a known cutting means.

  Further, the dart 423 (dart 423 formed on the upper end edge of the three-dimensional gather 4 according to the present invention depends on the number of the cuts 422 formed in the elastic elastic member 42, the interval between the cuts 422, and the length (depth) of the cuts 422. The number of pleats, the shape of the dart 423, and the size of the dart 423 change. Therefore, in order to form the desired dart 423, the number of cuts 422 formed in the elastic elastic member 42, the interval between the cuts 422, and the length (depth) of the cuts 422 may be adjusted as appropriate. For example, 10 to 200 or 50 to 100 notches 422 may be formed in the longitudinal direction of the elastic elastic member 42. Moreover, the distance between the notches 422 adjacent to the longitudinal direction of the elastic elastic member 42 may be set to 1 mm to 10 mm, or 3 mm to 8 mm, for example. Further, the length (depth) at which the notch 244 extends in the short direction of the elastic elastic member 42 may be, for example, 2 mm to 15 mm, or 5 mm to 20 mm. For example, the length may be 20% to 80% or 40% to 60%. Further, the distances between the cuts 422 may not be equal, and the cut depths may not be uniform. For example, the crotch part can be freely designed according to the use of the diaper, for example, by deepening the dart and making the dart shallower as it approaches the both ends of the rearing date.

  FIG. 5C shows a state in which the elastic elastic member 42 in the contracted state shown in FIG. 5B is pulled and elongated in the longitudinal direction. At this time, the notch 422 formed in the upper end edge of the elastic elastic member 42 in the contracted state 42 opens in the longitudinal direction of the elastic elastic member 42, and a gap 421 (notch) is formed in the elastic elastic member 42.

  The expansion / contraction rate of the elastic expansion / contraction member 42 is, for example, 110% to 250%, 130% to 230%, and particularly preferably 150% to 200%. Moreover, the elastic strength of the elastic elastic member 42 is, for example, 50 g to 400 g, 70 g to 300 g, and preferably 100 g to 200 g. Moreover, the width | variety (distance in the longitudinal direction of the elastic expansion-contraction member 42) of the space | gap 421 formed when the elastic expansion-contraction member 42 in which the notch 422 was formed is 1 mm-15 mm, or 5 mm-10 mm, for example, It is good also as 7 mm-8 mm.

  FIG. 5D shows a state in which the side sheets 40 forming the three-dimensional gather 4 are joined so as to sandwich the elastic elastic member 42 in the extended state shown in FIG. For example, a hot-melt adhesive or other fluid adhesive may be applied to both surfaces of the elastic elastic member 42 in an extended state, and bonded between the side sheets 40, for example, heat sealing The both sides of the elastic elastic member 42 in the stretched state and the side sheet 40 may be joined by heat welding or ultrasonic welding. At this time, the side sheets 40 can be joined to each other at the gap 421 formed in the elastic elastic member 42. However, in order to increase the flexibility of the upper end edge of the three-dimensional gather 4, it is preferable not to join the side sheets 40 in the gap 421 portion of the elastic elastic member 42.

  FIG.5 (e) has shown the state when the elastic elastic member 42 joined in the extended state between the side seat | sheets 40 shown by FIG.5 (c) contracted. At this time, the plurality of gaps 421 formed along the upper end edge of the elastic elastic member 42 in the extended state returns to the original notch 422 state or becomes extremely narrow as the elastic elastic member 42 contracts. It becomes. Accordingly, the portion of the side sheet 40 (the portion corresponding to the gap 421) located between the strip portions 424 of the elastic elastic member 42 in the extended state is bent to form a dart 423 (pleat).

  In this way, when a plurality of darts (folds) are formed at the upper edge of the three-dimensional gather 4 in the contracted state of the elastic expansion / contraction member 42 (the standing state of the three-dimensional gather 4), the looseness of the darts serves as a buffer Fulfill. For this reason, even if the upper end edge of the three-dimensional gather 4 is in contact with the wearer's skin for a long time, there is no risk of damaging the wearer's skin.

(4. Specific configuration of elastic elastic member: second embodiment)
Next, a second embodiment of the present invention will be described with reference to FIGS. In short, in the second embodiment, the rubber elastic elastic member 42 is disposed in a wave shape along the longitudinal direction of the three-dimensional gather 4 in the extended state, and as the elastic elastic member 42 contracts, Darts (folds) are formed at the upper edge of the three-dimensional gather 4.

  First, FIG. 6 is a schematic perspective view showing an enlarged part of the vicinity of the upper edge of the three-dimensional gather 4 in a state where the elastic elastic members 42a, 42b, and 42c are extended. Moreover, in FIG. 6, the elastic elastic members 42a, 42b, and 42c sandwiched between the side sheets 40 are transparently represented by broken lines.

  In the second embodiment shown in FIG. 6, a plurality of elastic rubber elastic members 42a, 42b, and 42c are used. However, the elastic elastic member 42 having a rubber thread shape may be one. Then, as shown in FIG. 6, the elastic elastic member 42 a disposed closest to the upper end edge of the three-dimensional gather is a convex that swings in the width direction of the three-dimensional gather 4 along the longitudinal direction of the three-dimensional gather 4. The curved portion 426 and the concave curved portion 427 form a continuous wave shape and are joined between the side sheets 40. A gap 421 is formed between the convex curves and between the concave curves at regular intervals. The gap 421 is formed between the convex curved portion 426 from the upper end edge side to the lower end edge side of the elastic elastic member 42a, and between the concave curved portion 427, the elastic elastic member 42a extends from the lower end edge side to the upper end edge side. Are formed.

  One or a plurality of elastic elastic members 42a, 42b, and 42c are joined between the side sheets 40 forming the three-dimensional gather 4 in the extended state. For example, a hot melt adhesive or other fluid adhesive may be applied to the elastic elastic members 42a, 42b, and 42c in an extended state, and bonded between the side sheets 40. The stretchable elastic elastic members 42a, 42b, and 42c and the side sheet 40 may be joined by such heat welding or ultrasonic welding.

  Here, in a state where the elastic elastic member 42a is extended, the distance between the tops of the convex curve portions 426 of the continuous elastic elastic member 42a and the top of the concave curve portion 427 of the continuous elastic elastic members 42a are appropriately determined. Can be changed. In particular, the number, shape, and size of darts 423 (folds) formed in the three-dimensional gather 4 to be described later vary depending on the distance between the tops of the convex curve portions 426. The distance between the tops of each convex curve part 426 and the distance between the tops of each concave curve part 427 may be, for example, 5 mm to 20 mm, or 10 mm to 15 mm.

  In addition, in a state where the elastic elastic member 42a is extended, the distance from the top of the convex curve portion 426 to the top of the concave curve portion 427 of the elastic elastic member 42a can be changed as appropriate. The number, shape, and size of darts 423 (folds) formed in the three-dimensional gather 4 to be described later also change depending on the distance from the top of the convex curve portion 426 to the top of the concave curve portion 427. The distance from the top of the convex curve portion 426 to the top of the concave curve portion 427 may be, for example, 5 mm to 20 mm, or 10 mm to 15 mm.

  Further, the elastic elastic member 42 a disposed closest to the upper end edge of the three-dimensional gather 4 is joined between the side sheets 40 so that the top of the convex curve portion 426 contacts the folded portion 41 of the side sheet 40. It is preferable that Further, even if the top of the convex curve portion 426 of the elastic elastic member 42a is not in contact with the folded portion 41 of the side seat 40, the distance between the top of the convex curve portion 426 and the folded portion 41 is, for example, 0 .1 mm to 5 mm, 0.2 mm to 3 mm, and 0.3 mm to 1 mm are preferable.

  FIG. 7 is an enlarged schematic perspective view showing a part of the vicinity of the upper end edge of the three-dimensional gather 4 in a state in which the elastic elastic members 42a, 42b, and 42c are contracted. Also in FIG. 7, the elastic elastic members 42a, 42b, and 42c sandwiched between the side sheets 40 are transparently represented by broken lines.

  That is, as shown in FIG. 7, when the elastic elastic member 42a disposed at the position closest to the upper edge of the three-dimensional gather 4 contracts, the three-dimensional gather 4 rises and is formed in the elastic elastic member 42a in the extended state. The gap 421 that has been narrowed. Thereby, in particular, a portion of the side sheet 40 (a portion corresponding to the gap 421) located between the convex curved portions 426 of the elastic elastic member 42a in the extended state is bent. When the elastic elastic members 42a, 42b, and 42c are in a contracted state (natural state) in which no tension is applied, a dart 423 (pleat) is formed by the bent portion of the side seat 40 as shown in FIG. . The dart 423 is formed at a position corresponding to the position of the gap 423 formed between the convex curves of the elastic elastic member 42a. The dart 423 is formed so as to extend in the thickness direction of the three-dimensional gather 4. In FIG. 7, all the darts 423 are formed in the front direction in the figure, but the darts 423 formed in the depth direction in the figure may exist.

  As described above, when the elastic elastic member 42a contracts, the dart 423 formed in the three-dimensional gather 4 becomes a movement allowance for the convex curved portion 426 of the elastic elastic member 42, and the concave curved portion 427 of the elastic elastic member 42a and other The linear elastic elastic members 42b and 42c can be moved with a high degree of freedom from the base point. For this reason, when the elastic elastic members 42a, 42b, and 42c are contracted (when the three-dimensional gather 4 is standing), the convex curve portion 426 of the elastic elastic member 42 is flexibly adapted to the unevenness and curvature of the wearer's skin. The shape changes.

  As described above, the problem of the present invention can also be solved by the second embodiment of the present invention.

  The disposable diaper according to the present invention can be applied to a disposable diaper for infants and the elderly. Therefore, the present invention can be suitably used in industries related to childcare and nursing care.

DESCRIPTION OF SYMBOLS 1 Top sheet 2 Back sheet 3 Absorber 4 Solid gather 10 Disposable diaper 40 Side sheet 41 Folding part 42 Elastic elastic member 43 Fixing line 51 Front body 52 Rear body 53 Crotch part 54 Side flap 55 Cover sheet 421 Cavity 422 Notch 423 Darts 424 Strip part 425 Continuous part 426 Convex curve part 427 Concave curve part

Claims (2)

A liquid-permeable top sheet (1), a liquid-impermeable back sheet (2), an absorber (3) interposed between the top sheet (1) and the back sheet (2), and the absorption In a disposable diaper including a three-dimensional gather (4) standing up along the side edges of the body (3),
The three-dimensional gather (4)
The side sheet (40) forming the three-dimensional gather (4) is folded at the folded portion (41) corresponding to the upper end edge of the three-dimensional gather (4),
Between the side sheets (40) folded back at the folded portion (41), an elastic elastic member (42) is disposed in an extended state along the longitudinal direction of the three-dimensional gather (4).
The elastic elastic member (42)
In the contracted state, an incision (422) formed from the upper end edge of the elastic elastic member (42) to the middle toward the short direction of the elastic elastic member (42) is a longitudinal direction of the elastic elastic member (42). Is formed in multiple,
An elastic stretchable member (42) in which the notch (422) is opened in a stretched state and a gap (421) extending in a short direction of the elastic stretchable member (42) is formed;
A disposable diaper in which a plurality of darts (423) are formed on an upper end edge of the three-dimensional gather (4) in a state where the elastic elastic member (42) is contracted . The elastic elastic member (42) is joined between the side sheets (40) such that the upper edge of the cut (422) is in contact with the folded portion (41) of the side sheet (40). ing
The disposable diaper according to claim 1 .

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