JP2008253285A - Pull-up type disposable diaper - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To improve the fitting property and outside appearance of a pull-up type disposable diaper by preventing projection of an interior body in the buttocks. <P>SOLUTION: In the pull-up type disposable diaper, the front end of the interior body 20 is connected to the inner surface of an abdomen side exterior sheet 12F at the center in the cross direction, and the rear end is connected to the inner surface of a back side exterior sheet 12B at the center in the cross direction. The abdomen side exterior sheet 12F is not continued to the back side exterior sheet 12B at the crotch side. The width W1 of the front end 56N and the rear end 56B of an absorbent core 56 is 100-200 mm. A narrow part 56N has the deepest part 56d whose width is 50-100 mm at a prescribed position in the intermediate area in the front/rear direction. The narrow part 56N is formed in such a shape that the width is continuously or gradually widened from the deepest part 56d toward the front side or rear side to the width of the front end 56F or the width W1 of the rear end 56B of the absorbent core. The deepest part 56d is located within the range of 15 mm to the front or to the rear from the center in the front/rear direction, and the narrow part 56N is extended forward at least by 100 mm and rearward at least by 40 mm from the center in the front/rear direction. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a pants-type disposable diaper in which an exterior sheet is divided into two parts, a stomach side and a back side.

A general pants-type disposable diaper has a joint opening formed on both sides by joining both sides of the front body and both sides of the back body, and a torso opening and a pair of left and right leg openings. It is provided with a formed exterior sheet and an interior body fixed in a range from the abdominal side through the crotch to the back side along the center of the inner surface in the width direction, and the wearer's legs are connected to the torso opening It is to be mounted by inserting it into the leg opening through. The interior body includes a liquid-permeable surface sheet and an absorbent core formed on the outer surface side and formed by a fiber assembly. As the fiber aggregate, those formed by stacking pulp fibers are widely used.
In recent years, a disposable diaper that can be referred to as a two-divided type in which the exterior sheet is divided into the abdomen and the dorsal side has been proposed (see Patent Document 1, for example). ). The two-divided type has advantages in that there are few trims (excess disposal portions) when punching out the leg openings at the time of manufacture, and that each material of the abdominal exterior sheet and the back exterior sheet can be individually selected.
JP 2005-027839 A

However, in the two-split type, if the front / rear direction middle part of the absorbent core is bundled along the legs in order to improve the fit around the legs, the wearer repeats walking, so that the interior body is on the back side. By moving, the part which covers a buttocks protrudes like a duck's tail, and there existed a problem that the phenomenon which worsens fitting property and appearance occurred.
Then, the main subject of this invention is preventing protrusion of the interior body in a collar part, and improving fitting property and appearance.

The present invention that has solved the above problems is as follows.
<Invention of Claim 1>
The abdomen exterior sheet covering the abdominal side of the wearer's waist and the back exterior sheet covering the back side, with the upper edge of the abdomen exterior sheet and the upper edge of the back exterior sheet aligned, A cylindrical waistline portion formed by joining the joint portions on both side edges in the width direction of the side exterior sheet and the joint portions on both side edges in the width direction of the back side exterior sheet;
The front end is connected to the inner surface in the width direction central portion of the ventral exterior sheet, the rear end is connected to the inner surface in the width direction central portion of the back exterior sheet, and passes from the back side to the ventral side through the crotch portion. And an interior body covering
The interior body includes a liquid-permeable surface sheet and an absorbent core formed by a fiber assembly,
In the pants-type disposable diaper in which the ventral side exterior sheet and the back side exterior sheet are not continuous on the crotch side and are separated from each other,
The absorbent core has a front end portion, a rear end portion, and a constricted portion that is narrower than the front end portion and the rear end portion, and is positioned between them.
The absorption core front end and absorption core rear end have a width of 100 to 200 mm,
The constricted portion has a deepest portion having a width of 50 to 100 mm at a predetermined portion in the middle in the front-rear direction, and the width of the absorbent core front end portion and the width of the absorbent core rear end portion from the deepest portion toward the front side and the rear side, respectively. It has a shape that widens continuously or stepwise up to the width,
The deepest part is located within a range of 15 mm before and after the center in the front-rear direction,
The constricted part extends 100 mm or more on the front side and 40 mm or more on the rear side with respect to the center in the front-rear direction.
A pants-type disposable diaper characterized by that.

(Function and effect)
In the pants-type disposable diaper of the present invention, as shown in FIG.
(Ii) The front / rear length of the constricted portion 56N of the absorbent core 56 is widely secured, and the constricted portion 56N prevents the wearer's leg 100 from moving back and forth (indicated by a two-dot chain white arrow in FIG. 6). Since it is difficult for the wearer's leg 100 to exert a force in the front-rear direction against the absorbent core 56N,
(B) Since the position in the front-rear direction of the deepest portion of the constricted portion 56N is shifted rearward from the position where the distance between the legs 100 of the wearer is the narrowest, when the wearer's leg 100 moves backward It is difficult to apply a backward force to the absorbent core 56N (ie, when the wearer's leg 100 moves back and forth, the force applied to the absorbent core 56N in the forward direction causes the wearer's leg 100 to move backward. The force is greater than the force applied to the absorption core 56N in the rearward direction when moving to the right).
As a result, in the disposable diaper of the present invention, even if the wearer repeats walking, it becomes difficult to apply a rearward force to the interior body 20 in the crotch part, and the interior body 20 becomes difficult to move to the back side. The part covering the buttock becomes difficult to protrude like a duck tail, and deterioration of fit and appearance are prevented.

<Invention of Claim 2>
The pants-type disposable diaper according to claim 1, wherein a lower end of the belly side exterior sheet is positioned near a front end of the constricted portion, and a lower end of the back side exterior sheet is positioned near a rear end of the constricted portion.

(Function and effect)
When configured as described in this section, the front and rear movements of the wearer's legs are less likely to be hindered by the abdominal exterior sheet and the back exterior sheet. It becomes difficult to reach the body. Therefore, the effects of the present invention described above are further enhanced.

<Invention of Claim 3>
When the crossing angle between the tangential direction at the front end of both side edges of the constricted portion and the front-rear direction is θ1, and the crossing angle between the tangential direction and the front-back direction at the rear ends of both side edges of the constricted portion is θ2, 10 degrees ≦ The pants-type disposable diaper according to claim 2, wherein the shape of the constricted portion is formed so as to satisfy a magnitude relationship of θ1 ≦ θ2 ≦ 60 degrees.

(Function and effect)
If the crossing angle is too shallow, it is difficult to secure the position of the deepest portion at the position of the present invention, and the angle change of the absorption core side edge in the vicinity of the deepest portion becomes abrupt, which may deteriorate the wearing feeling. In addition, if the crossing angle is too deep, the width of the absorbent core is abruptly narrowed, which may deteriorate the wearing feeling. Therefore, it is desirable to configure as described in this section.

<Invention of Claim 4>
Both side edges of the constricted part are a rear end side arcuate part located on the rear end side in the front-rear direction, a front end side arcuate part located on the front end side in the front-rear direction, and the rear end side arcuate part between them. A linear portion connecting the front end and the rear end of the front end side arcuate portion and extending along a tangential direction at the rear end of the front end side arcuate portion;
The radius of curvature of the rear end side arc-shaped portion is larger than that of the front end side arc-shaped portion, the linear portion is inclined so that the width of the constricted portion becomes wider toward the front side in the front-rear direction, and the rear end side circle The pants-type disposable diaper according to claim 3, wherein the deepest portion is located at an intermediate position in the front-rear direction of the arc-shaped portion.

(Function and effect)
The narrow portion of the absorbent core described in this section has a two-stage constriction. That is, the constricted portion of the absorbent core described in this section includes a front end side arc-shaped portion and a linear portion that are smoothly and gently narrowed, and a rear end side arc-shaped portion that is constricted deeper than an extension line of the linear portion. And the deepest part is located at the intermediate position in the front-rear direction of the rear end side arc-shaped part. Therefore, when the wearer's leg moves to the front side, the leg hits the arcuate part and the straight part on the front end side where the width is smoothly and gently narrowed, and the movement force of the leg is weak and acts on the interior body gently. Will come to do. On the other hand, when the wearer's leg moves to the rear side, the rear end side arc-shaped portion is formed deeper by one step, so that the leg hardly hits the rear end side arc-shaped portion and acts on the interior body. The force to do is much weaker than when the legs move forward. Therefore, in the invention described in this section, the above-described effects of the present invention are further enhanced.

  As described above, according to the present invention, it is possible to prevent the inner body from projecting in the collar portion, thereby providing advantages such as improved fit and appearance.

Hereinafter, the present invention will be described in more detail with reference to embodiments shown in the drawings.
<First Embodiment>
1 to 8 show an example of a pants-type disposable diaper according to the present invention. In FIG. 1, “front-rear direction” means a direction connecting the abdomen and the back side, “width direction” means a direction orthogonal to the front-rear direction, and “up-down direction” means a waistline direction. It means a direction orthogonal to each other, in other words, a direction connecting the waist opening WO side and the crotch side.
This pants-type disposable diaper 10 has a ventral exterior sheet 12F that covers the abdominal side of the wearer's waist and a back exterior sheet 12B that covers the back side, and both side edges of the abdominal exterior sheet 12F in the width direction. The joining portion 12A and the joining portions 12A on both side edges in the width direction of the back exterior sheet 12B are joined by heat sealing, ultrasonic welding, or the like to form a cylindrical waistline portion 12. When the back exterior sheet 12B extends below the joining portion 12A as in the illustrated embodiment, the extension is integrally processed by heat sealing or the like in the vertical range including this portion. A welding part can be provided. By providing the extension weld portion, it is possible to prevent the second elongated elastic elastic member 16 from being pulled in the back side extension portion 14 described later. In this case, considering the ease of breakage of the side portion, the joining portion 12A is generally composed of a collection of small welded portions, and is generally a joining pattern having a low ratio of the welding area in the joining portion 12A. Since it is not necessary to consider the ease of tearing at the welded portion, the second elongated elastic elastic member 16 is surely welded and fixed by increasing the ratio of the welded area of the welded pattern as compared with the joining portion 12A. Also good. Further, the extended welded portion is welded with a curved line at the edge of the collar cover portion 14C, and the second elongated elastic elastic member 16 of the collar cover portion 14C can be prevented from being pulled.
In addition, the front end of the interior body 20 is connected to the inner surface of the waist portion 12F in the width direction center portion of the abdominal exterior sheet 12F by a hot melt adhesive or the like, and the interior body is connected to the inner surface of the back side exterior sheet 12B in the width direction center portion. The rear end portions of 20 are connected by a hot melt adhesive or the like, and the abdominal side exterior sheet 12F and the back side exterior sheet 12B are not continuous on the crotch side and are separated. This separation distance Y can be about 150 to 250 mm.
As can be seen from FIGS. 7 and 8, the upper opening of the waistline portion 12 becomes a waist opening WO through which the wearer's torso passes, and the lower edge of the waistline portion 12 and the interior body 20 on both sides in the width direction of the interior body 20. The portions surrounded by the side edges are leg openings LO through which the legs pass. In a state where each joint 12A is peeled off and developed, an hourglass shape is formed as shown in FIG. The interior body 20 extends from the back side through the crotch part to cover the abdomen side, and is a part that receives the excrement and absorbs and holds the liquid, and the waistline part 12 holds the interior body 20. This is the part that supports the wearer.

(Exterior sheet)
As shown in FIGS. 4 and 5, the abdominal exterior sheet 12 </ b> F and the back exterior sheet 12 </ b> B are formed by laminating two sheets S <b> 1 and S <b> 2 such as non-woven fabrics. , S2 are provided with elongated elastic elastic members 15 to 19 such as rubber thread at a predetermined extension rate. When using a nonwoven fabric, it is preferable that the basic weight shall be about 10-30 g / m < ² >. The nonwoven fabric is not particularly limited as to what the raw fiber is. For example, synthetic fibers such as olefins such as polyethylene and polypropylene, polyesters and polyamides, recycled fibers such as rayon and cupra, natural fibers such as cotton, and mixed fibers and composite fibers using two or more of them. Etc. can be illustrated. Furthermore, the nonwoven fabric may be manufactured by any processing. Examples of the processing method include known methods such as a spunlace method, a spunbond method, a thermal bond method, a melt blown method, a needle punch method, an air through method, and a point bond method. Further, as the elongated elastic elastic members 15 to 18, 19T, and 19U, synthetic rubber or natural rubber may be used.
More specifically, the back-side exterior sheet 12B includes a back-side main body portion 13 that occupies the same vertical range as the joint portion 12A, and a back-side extension portion 14 that extends below the back-side main body portion 13. Have. The back side extension part 14 has the width direction center part 14M which overlaps with the absorptive main body 20, and the collar part cover part 14C extended to the both sides.

The shape of the dorsal extension 14 can be determined as appropriate, but in the illustrated example, the upper end of the dorsal extension 14 has the same width as the dorsal body 13 and extends below the dorsal body 13. The width is narrowed as the lower side approaches the crotch side. A portion having the same width as that of the back-side main body 13 can be omitted. If comprised in this way, the edge 14e of the width direction outer side of the buttock cover part 14C will come in the shape of a straight line or a curve which approaches the absorptive main body 20 side as it approaches the crotch side, and covers the buttock part. Easy shape.
Although the dimension of the back side extension part 14 can be determined suitably, as shown in FIG. 6, the width direction length 14x of the collar part cover part 14C (the edge 14e on the width direction outer side of the collar part cover part 14C and the absorbent main body 20) It is more preferable that the maximum distance in the width direction with respect to the side edge is 80 to 160 mm, and the length 14y (extending length) in the vertical direction of the collar cover portion 14C is 30 to 80 mm. Further, assuming that the area of a quadrangle determined by the widest part in the width direction and the widest part in the vertical direction is S, the area of the back side extension part 14 is 20 to 80% of S, In particular, it is preferable that the content is about 40 to 60% because the outer appearance and wearing feeling of the buttocks are excellent.

The back body 13 can be conceptually divided into an upper end (waist part) W and a lower part U below the upper part in the vertical direction, and the range varies depending on the size of the product. The vertical length of the upper end W can be 15 to 80 mm, and the vertical length of the lower portion U can be 35 to 220 mm.
A plurality of back-side waist elastic elastic members 17 are vertically spaced at the upper end (waist) W of the back-side main body 13 so as to be continuous over the entire width direction and at a predetermined extension rate. It is fixed in a stretched state along the width direction. Moreover, about the 1 or several arrange | positioned in the area | region adjacent to the lower part U of the back side main-body part 13 among the back side waist part elastic elastic members 17, you may overlap with the absorption core 20. Alternatively, it may be provided on both sides in the width direction except for the central portion in the width direction that overlaps the absorbent main body 20. The back waist elastic elastic member 17 has a thickness of 155 to 1880 dtex, particularly about 470 to 1240 dtex (in the case of synthetic rubber. In the case of natural rubber, the cross-sectional area is 0.05 to 1.5 mm ² , particularly 0.1 to the rubber thread of 1.0mm about ^2), 3 to 22 present approximately at intervals of 4 to 12 mm, an extension ratio 150% to 400%, preferably fixed in particular about 220-320%. Further, it is not necessary for all of the back side waist elastic elastic members 17 to have the same thickness and extension rate. For example, the elastic waist members may have different thicknesses and extension rates at the upper and lower portions of the back waist part. Good. The back waist elastic elastic member 17 can be freely determined with respect to the first and second elongated elastic elastic members 15 and 16 regardless of the size or the expansion rate.
Further, in the lower portion U of the back-side main body portion 13, a plurality of portions are continuous so as to be continuous over the entire width direction at each of the upper side and both sides in the width direction except for the width-direction central portion overlapping the absorbent main body 20. The first elongated elastic elastic members 15 are fixed in a state where they are extended along the width direction at a predetermined extension rate with an interval in the vertical direction.

The first elongated elastic elastic member 15 has a thickness of 155 to 1880 dtex, particularly about 470 to 1240 dtex (in the case of synthetic rubber. In the case of natural rubber, the cross-sectional area is 0.05 to 1.5 mm ² , particularly 0.1. the rubber thread ~1.0mm about ^2), 1 to 15 mm, particularly 5 to 30 present approximately at intervals of 3 to 8 mm, at an extension rate of 200 to 350%, preferably fixed in particular about 240-300%.
Moreover, in the back side extension part 14, except for the width direction center part which overlaps with the absorptive main body 20, it extends so that it may continue to each site | part of the width direction both sides over the whole width direction (at least over the whole collar cover part 14C). In addition, the plurality of second elongated elastic elastic members 16 are fixed in a state where they are extended in the width direction at a predetermined extension rate with a space in the vertical direction.
The second elongated elastic elastic member 16 has a thickness of 155 to 1880 dtex, especially about 470 to 1240 dtex (in the case of synthetic rubber. In the case of natural rubber, the cross-sectional area is 0.05 to 1.5 mm ² , particularly 0.1. It is preferable that about ² to 10 thread rubbers having an interval of 5 to 40 mm, particularly 5 to 20 mm, and an elongation ratio of 150 to 300%, particularly 180 to 260%, are fixed.

On the other hand, the abdominal exterior sheet 12F is composed of only the abdominal body part basically the same as the back body part 13 of the back exterior sheet 12B (the part occupying the same vertical range as the joint part 12A). It has a rectangular shape extending along the direction, and does not have the back side extension portion 14 like the back side exterior sheet 12B.
That is, among the upper end portion (waist portion) W and the lower portion U of the ventral side exterior sheet (abdominal side main body portion) 12F, the upper end portion W has a plurality of ventral side waist portions so as to be continuous over the entire width direction. The elastic elastic members 18 are fixed in a state where they are extended along the width direction at a predetermined extension rate with a space in the vertical direction. The ventral waist elastic elastic member 18 is preferably as close as possible to the back waist elastic elastic member 17 in terms of number, thickness, stretch rate, spacing, and vertical arrangement, but may be different. When differentiating, the difference in number is 10 or less, preferably 5 or less, the difference in thickness is 1880 dtex or less, preferably 470 dtex or less, the difference in elongation is 100% or less, preferably 40% or less, the difference in spacing Is 10 mm or less, preferably 5 mm or less.

Further, in the lower portion U of the abdominal exterior sheet 12F (abdominal body portion), the width direction center portion overlaps with the absorbent main body 20, and the entire width direction is applied to each portion on the upper side and both sides in the width direction. A plurality of third elongated elastic elastic members 19 are fixed in a state of being stretched along the width direction at a predetermined stretch rate at intervals in the vertical direction so as to be continuous. Although the vertical disposition range of the third elongated elastic elastic member 19 may be a part of the lower portion, it is preferable that the third elongated elastic elastic member 19 is substantially the whole (a range in which the expansion / contraction force acts on the whole).
The third elongated elastic elastic member 19 is preferably as close as possible to the first elongated elastic elastic member 15 in terms of number, thickness, stretch rate, spacing, and vertical arrangement, but may be different. When differentiating, the difference in number is 10 or less, preferably 5 or less, the difference in thickness is 1880 dtex or less, preferably 470 dtex or less, the difference in elongation is 100% or less, preferably 40% or less, the difference in spacing Is 10 mm or less, preferably 5 mm or less.

The abdominal exterior sheet 12F in the illustrated form is composed of only a portion that occupies the same vertical range as the joint portion 12A, but, similarly to the back side, a ventral main body portion that occupies the same vertical range as the joint portion 12A; In addition, a configuration including an abdominal-side extension portion extending below the abdominal-side main body portion may be employed. Thereby, the leg periphery shape of the abdominal exterior sheet | seat 12F can be made into the shape fitted along a buttock. In this case, the area of the ventral extension part is preferably 10 to 80% of the area of the dorsal extension part, and more preferably 20 to 50%. If the ventral extension is excessively large, the fit is rather impaired, which is not preferable.
On the other hand, as shown in the figure, the first and second elongated elastic elastic members 15 and 16 are provided on both sides in the width direction except for the central portion in the width direction, which overlaps the absorbent main body 20, respectively. In addition to the configuration in which elastic elastic members exist only on both sides in the width direction, the elastic elastic members exist from one side of the width direction to the other side across the absorbent main body 20, but the width direction center overlapping the absorbent main body 20 Also included is a configuration in which the elastic stretchable member is cut at the portion so that the stretchable force does not act (substantially equal to not providing the elastic stretchable member). Moreover, in this invention, the 1st and 2nd elongate elastic expansion-contraction members 15 and 16 are made into an absorptive main body so that a stretching force may act on the whole width direction of the back side main-body part 13 and the back side extension part 14. FIG. It can also be provided across from 20 to the other side in the width direction.

(Interior body)
The interior body 20 can take any shape, but is rectangular in the illustrated form. As shown in FIG. 3, the interior body 20 includes a surface sheet 30 on the body side, a liquid-impermeable sheet, and an absorbent element 50 interposed therebetween. On the back side of the liquid-impermeable sheet 70, a crotch part is provided so as to cover the entire back surface of the interior body 20 or to cover the entire portion exposed between the abdominal exterior sheet 12F and the back exterior sheet 12B. The exterior sheet 12M can also be fixed. In addition, an intermediate sheet (second sheet) 40 can be provided between the top sheet 30 and the absorbent element 50 in order to quickly transfer the liquid that has passed through the top sheet 30 to the absorbent element 50. Furthermore, in order to prevent excrement from leaking on both sides of the absorption part 20, barrier cuffs 60 and 61 standing on the body side can be provided on both sides of the interior body 20. Although not shown, the constituent members of the interior body 20 can be appropriately fixed to each other by solid, bead or spiral application such as hot melt adhesive. The interior body 20 can also be detachably attached to the exterior sheet 20 using a mechanical fastener or an adhesive material.

(Surface sheet)
The top sheet 30 has a property of transmitting liquid. Therefore, the material of the top sheet 30 is sufficient if it exhibits this liquid permeability, and examples thereof include a porous or non-porous nonwoven fabric and a porous plastic sheet. Of these, the nonwoven fabric is not particularly limited as to what the raw fiber is. For example, synthetic fibers such as olefins such as polyethylene and polypropylene, polyesters and polyamides, recycled fibers such as rayon and cupra, natural fibers such as cotton, and mixed fibers and composite fibers using two or more of them. Etc. can be illustrated. Furthermore, the nonwoven fabric may be manufactured by any processing. Examples of the processing method include known methods such as a spunlace method, a spunbond method, a thermal bond method, a melt blown method, a needle punch method, an air through method, and a point bond method. For example, if flexibility and drapeability are required, the spunbond method and spunlace method are preferable. If bulkiness and softness are required, the air-through method, point bond method, and thermal bond method are preferable processing methods. .
Further, the top sheet 30 may be composed of one sheet or may be composed of a laminated sheet obtained by bonding two or more sheets. Similarly, the top sheet 30 may be composed of one sheet or two or more sheets in the planar direction.
When the barrier cuffs 60 and 61 are provided, both side portions of the top sheet 30 pass between the liquid-impermeable sheet 70 and the barrier cuffs 60 and 61 to the back side of the absorbent element 50 to prevent liquid penetration. Therefore, it is preferable to adhere to the liquid-impermeable sheet 70 and the barrier cuffs 60 and 61 with a hot melt adhesive or the like.

(Intermediate sheet)
In order to quickly transfer the liquid that has passed through the top sheet 30 to the absorbent core, an intermediate sheet 40 that is faster than the top sheet 30 and that is normally called “second sheet” can be provided. This intermediate sheet 40 not only improves the absorption performance by the absorption core by quickly transferring the liquid to the absorption core, but also prevents the “reversal” phenomenon of the absorbed liquid from the absorption core, and always dries the top sheet 30. It can be made into the state which carried out. The intermediate sheet 40 can be omitted.
Examples of the intermediate sheet 40 include the same material as the top sheet 30, spunlace, pulp nonwoven fabric, a mixed sheet of pulp and rayon, point bond, or crepe paper. In particular, an air-through nonwoven fabric and a spunbond nonwoven fabric are preferable.
The intermediate sheet 40 in the illustrated form is disposed in the center shorter than the width of the absorbent core 56, but may be provided over the entire width. The length of the intermediate sheet 40 in the longitudinal direction may be the same as the length of the absorbent core 56, or may be within a short length range centered on the region that receives the liquid. A typical material of the intermediate sheet 40 is a nonwoven fabric having excellent liquid permeability.

(Liquid impervious sheet)
The material of the liquid-impermeable sheet 70 is not particularly limited. For example, an olefin resin such as polyethylene or polypropylene, a laminated nonwoven fabric obtained by laminating a nonwoven fabric on a polyethylene sheet, or a waterproof film is substantially interposed. Non-woven fabrics that ensure liquid impermeability (in this case, a liquid-impermeable sheet is composed of a waterproof film and a non-woven fabric). Of course, in addition to this, materials having liquid impermeability and moisture permeability, which have been used and used in recent years from the viewpoint of preventing stuffiness, can also be exemplified. As the sheet of the material having liquid impermeability and moisture permeability, for example, an inorganic filler is kneaded in an olefin resin such as polyethylene or polypropylene, and the sheet is formed, and then stretched in a uniaxial or biaxial direction. Examples of the microporous sheet obtained in this way can be given. In addition, non-woven fabric using micro-denier fiber, strengthening leak-proofing by reducing the voids of the fiber by applying heat or pressure, and applying water-absorbing resin or hydrophobic resin or water repellent. A sheet that is liquid-impermeable without using a film can also be used as the liquid-impermeable sheet 70.
The liquid-impermeable sheet 70 is preferably extended around both sides of the absorbent element 50 to both sides of the side surface 30 of the absorbent element 50 in order to improve leakage prevention.
Further, the inner surface or the outer surface of the liquid-impermeable sheet 70 may be designed by printing or coloring. Further, a printed or colored design sheet, which is a separate member from the crotch outer sheet 12M, may be attached to the outside of the liquid-impermeable sheet 70. Further, an excretion indicator 80 whose color changes due to absorption of the liquid component can be provided inside the liquid-impermeable sheet 70.

(Barrier cuffs)
The barrier cuffs 60 and 61 are belt-like members extending along the both sides of the interior body 20 over the entire front-rear direction, and prevent urine and soft stool that move along the top sheet 30 in the lateral direction and prevent side leakage. It is provided to prevent this.
In the present embodiment, as shown in FIGS. 3 and 4, the barrier cuffs 60 and 61 are provided twice on the left and right sides of the interior body 20. The first barrier cuff 61 is erected obliquely from the side of the interior body 20 toward the center in the width direction, and the second barrier cuff 60 is disposed outside the first barrier cuff 61 in the width direction. The base side portion stands obliquely toward the center in the width direction, and the tip side portion from the intermediate portion stands obliquely outward in the width direction.
More specifically, the first barrier cuff 61 includes a belt-like barrier sheet 62 having a length equal to the length in the front-rear direction of the interior body 20 and folded in two in the width direction. A plurality of elongated elastic elastic members 63 are fixed between the sheets in a stretched state along the longitudinal direction at intervals in the width direction. The portion of the first barrier cuff 61 opposite to the folded portion in the width direction is an attachment portion 65 for the interior body 20, and the liquid impermeable sheet 70 is formed from the side in the width direction on the body side surface of the top sheet 30. It wraps around to the side in the width direction on the back surface, and is bonded and fixed in that range with a hot melt adhesive or the like. Further, the protruding portion 66 (the portion on the folded portion side) other than the mounting portion 65 extends to the center in the width direction, and both front and rear direction end portions of the protruding portion 66 are attached to the surface of the topsheet 30 with a hot melt adhesive 67 or the like. The middle part in the front-rear direction is an unfixed free part. A water-repellent nonwoven fabric or the like can be used as the barrier sheet 62, and a thread rubber or the like can be used as the elongated elastic elastic member 63.
The second barrier cuff 60 also has basically the same structure as the first barrier cuff 61, except that the attachment portion 65 is adhesively fixed to the outer surface of the first barrier sheet 61, and the protruding portion 66. Is folded outward in the width direction at the middle in the width direction, and the elongated elastic elastic member 63 is provided on the tip side from the folded portion, and at the both ends in the front-rear direction of the protruding portion 66, the root side The portion is different in that it is adhesively fixed to the first barrier cuff 61 and the tip side portion is adhesively fixed to the base side portion.
In the first and second barrier cuffs 60 and 61 configured as described above, the contraction force of the elongated elastic elastic member 63 acts so as to bring the both ends in the front-rear direction close to each other. Since they are fixed so as not to be fixed, they are non-fixed free parts, so that only the free parts stand on the body side of the face sheet 30 as shown in FIG.
Unlike the illustrated embodiment, only one of the first and second barrier cuffs 60 and 61 can be provided.

(Absorption element)
The absorbent element 50 includes an absorbent core 56 and a covering sheet 58 that wraps at least the back and side surfaces of the absorbent core 56. The covering sheet 58 can be omitted.

(Absorption core)
The absorbent core 56 may be a core made of filaments such as cellulose acetate, as well as a core of short fibers such as cotton pulp. It is preferable to disperse and hold superabsorbent polymer particles in the absorbent core 56.
Characteristically, as shown also in FIG. 6, the absorption core 56 is located at the front end portion 56F, the rear end portion 56B, and between these, and is a narrow portion having a narrower width than the front end portion 56F and the rear end portion 56B. 56N. The front and rear direction length L3 + L4 of the constricted portion 56N is 100 mm or more, preferably 120 to 240 mm, and the rear side length L5 is 40 mm or more, preferably 60 to 120 mm. . The front-rear direction length L8 of the entire constricted portion 56N is preferably 140 mm or more, and particularly preferably 180 to 360 mm.
The longitudinal length L2 of the absorbent core front end portion 56F is preferably 10 to 150 mm, and particularly preferably 20 to 50 mm. The length L6 in the front-rear direction of the absorbent core rear end portion 56B is preferably 70 to 280 mm, and particularly preferably 100 to 180 mm.
The width W1 of the absorbent core front end portion 56F and the absorbent core rear end portion 56B is 100 to 200 mm, preferably 140 to 180 mm. Further, the constricted portion 56N has the narrowest deepest portion 56d at a predetermined portion in the middle in the front-rear direction, and the width of the absorbent core front end portion 56F and the rear of the absorbent core are increased from the deepest portion 56d toward the front side and the rear side, respectively. The shape is such that the width is continuously increased (may be stepwise) up to the width W1 of the end portion 56B. The width W2 of the absorption core 56 in the deepest part 56d is 50 to 100 mm, preferably 70 to 90 mm.
Characteristically, the distance in the front-rear direction between the position in the front-rear direction of the deepest portion 56d and the center CL in the front-rear direction of the diaper is within 15 mm in the front-rear direction, more preferably within 5 mm in the front-rear direction.

When the absorbent core 56 is formed in this way, it is difficult to apply a rearward force to the interior body 20 in the crotch portion, even if the wearer repeats walking, due to the above-described principle. By being difficult to be brought to the side, the portion covering the buttock becomes difficult to protrude like a duck tail, and deterioration of fit and appearance are prevented.
In particular, in order to further enhance this effect, the lower end of the ventral exterior sheet 12F is positioned in the vicinity of the front end of the constricted portion 56N of the absorbent core 56, and the lower end of the back exterior sheet 12B is confined to the constricted portion of the absorbent core 56. It is preferable to be positioned near the rear end of 56N. If comprised in this way, since the back-and-forth movement of a wearer's leg will become difficult to be prevented by the abdominal exterior sheet | seat 12F and the back | dorsal exterior sheet | seat 12B, the back-and-forth movement of a wearer's leg will be via the exterior sheet | seats 12F and 12B. It becomes difficult to reach the interior body 20. In addition, the fit along the leg circumference is enhanced.

The shape of the constricted portion 56N is such that the intersection angle between the tangential direction at the front end of both side edges of the constricted portion 56N and the front-rear direction is θ1, and the angle between the tangential direction at the rear end of both side edges of the constricted portion 56N and the front-rear direction. Is preferably θ2 satisfying the magnitude relationship of 10 degrees ≦ θ1 ≦ θ2 ≦ 60 degrees. A more preferable magnitude relationship is 15 degrees ≦ θ1 ≦ θ2 ≦ 45 degrees. Further, it is more preferable that θ1 <θ2.
If these intersecting angles θ1 and θ2 are too shallow, it becomes difficult to design the position of the deepest portion 56d in the vicinity of the center CL in the front-rear direction, and the angle change of the side edge of the absorbent core 56 in the vicinity of the deepest portion 56d becomes abrupt. The feeling may get worse. In addition, if the intersecting angles θ1 and θ2 are too deep, the width of the absorbent core 56 is abruptly narrowed, which may deteriorate the feeling of wearing.

Further, both side edges of the constricted portion 56N are a rear end side arc-shaped portion N1 positioned on the rear end side in the front-rear direction, a front end side arc-shaped portion N2 positioned on the front end side in the front-rear direction, and a rear end side circle between them. It consists of a linear part N3 connecting the front end of the arcuate part N1 and the rear end of the front end side arcuate part N2, and the curvature radius R1 of the rear end side arcuate part N1 is greater than the curvature radius R2 of the front end side arcuate part N2. The linear portion N3 is inclined so that the width of the constricted portion 56N becomes wider toward the front side in the front-rear direction, and the deepest portion 56d is positioned at the middle position in the front-rear direction of the rear end side arc-shaped portion N1. As a result, the above-described effect is further enhanced.
That is, when the constricted portion 56N of the absorbent core 56 has such a two-stage constriction, when the wearer's leg moves forward, the leg is smoothly and gently narrowed in the front end side arc shape. When hitting the portion N2 and the linear portion N3, the leg moving force is weak and acts gently on the interior body 20. On the other hand, when the wearer's leg moves to the rear side, the rear end side arc-shaped portion N1 is formed deeper by one step, so that the leg does not easily hit the rear end side arc-shaped portion N1, and the inner body 20 The force acting on the leg is much weaker than when the leg moves forward.

In addition, the preferable dimensional relationship of the absorption core 56 is as follows.
(1) 1.5 ≦ L1 / (L2 + L3) ≦ 10.0
If L1 / (L2 + L3) is smaller than 1.5, the distance from the end of the product to the absorber is short, and it is easy to squeeze the stomach, and if it is larger than 10, the length of L2 is too short and it is easy to cause creaking / breaking. Also, manufacturing defects are likely to occur.
(2) 0 <L3 <L1
When L3 is 0, the constricted portion 56N does not exist up to the starting position of the leg movement, and the leg movement is suppressed.
(3) 1.5 ≦ (L3 + L4) /L5≦3.5
When (L3 + L4) / L5 is smaller than 1.5, it becomes difficult to secure the position of the deepest portion 56d in the vicinity of the center CL in the front-rear direction, and when it is larger than 3.5, the distance from the waist opening to the absorbent core 56 is shortened. , Easy to leak stomach.
(4) 1.0 <L7 / L8 ≦ 2.0
If L7 / L8 is smaller than 1.0, the lengths of L2 and L6 are too short, so that they are likely to be broken and broken, and manufacturing defects are likely to occur. On the other hand, when L7 / L8 is larger than 2.0, the constricted portion 56N does not exist up to the starting position of the leg movement, and the leg movement is suppressed.
(5) 1.1 <W1 / W2 ≦ 2.0
When W1 / W2 is 1.1 or less, the constricted portion 56N is shallow, and the fit of the crotch portion tends to be insufficient, and when it is larger than 2.0, the width at the deepest portion 56d is too narrow and the absorption core strength is insufficient. There is a fear.

(Superabsorbent polymer particles)
Superabsorbent polymer particles include “powder” in addition to “particles”. As the particle diameter of the superabsorbent polymer particles, those used in this type of absorbent article can be used as they are, and those having a particle size of 1000 μm or less, particularly 150 to 400 μm are desirable. The material of the superabsorbent polymer particles can be used without any particular limitation, but those having a water absorption of 40 g / g or more are suitable. High-absorbency polymer particles include starch-based, cellulose-based and synthetic polymer-based particles, such as starch-acrylic acid (salt) graft copolymers, saponified starch-acrylonitrile copolymers, and sodium carboxymethylcellulose crosslinks. Or an acrylic acid (salt) polymer can be used. As the shape of the superabsorbent polymer particles, a commonly used granular material is suitable, but other shapes can also be used.
As the superabsorbent polymer particles, those having a water absorption rate of 40 seconds or less are preferably used. When the water absorption speed exceeds 40 seconds, the liquid supplied into the absorption core 56 is liable to cause a so-called reversal that returns to the outside of the absorption core 56.
Further, as the superabsorbent polymer particles, those having a gel strength of 1000 Pa or more are preferably used. Thereby, even if it is a case where it is set as the bulky absorption core 56, the sticky feeling after liquid absorption can be suppressed effectively.
The basis weight of the superabsorbent polymer particles can be appropriately determined according to the amount of absorption required for the use of the absorbent core 56. Therefore, although it cannot be said unconditionally, it can be set to 50 to 350 g / m ² . If the amount of polymer is less than 50 g / m ^2, it is difficult to secure the absorption amount. When it exceeds 350 g / m ² , the effect is saturated.
If necessary, the superabsorbent polymer particles can adjust the spray density or spray amount in the plane direction of the absorbent core 56. For example, it is possible to increase the application amount of the liquid excretion site as compared to other sites. When gender differences are taken into account, men can increase the front spray density (amount), while women can increase the center spray density (amount). In addition, a portion where no polymer exists locally (for example, in a spot shape) in the planar direction of the absorbent core 56 may be provided.

(Enveloping sheet)
When the covering sheet 58 is used, as the material, tissue paper, particularly crepe paper, non-woven fabric, polylaminated non-woven fabric, a sheet with small holes, or the like can be used. However, it is desirable that the superabsorbent polymer particles be a sheet that does not escape. When a nonwoven fabric is used instead of the crepe paper, a hydrophilic SMMS (spunbond / meltblown / meltblown / spunbond) nonwoven fabric is particularly suitable, and polypropylene, polyethylene / polypropylene, etc. can be used as the material. The basis weight is preferably 5 to 40 g / m ² , particularly 10 to 30 g / m ² .
As shown in FIG. 2, the covering sheet 58 may cover only the back surface and side surfaces of the layer in addition to the form for covering the entire absorbent core 56. Although not shown, only the upper and side surfaces of the absorbent core 56 are covered with crepe paper or nonwoven fabric, and the lower surface is covered with a liquid-impermeable sheet such as polyethylene, and the upper surface of the absorbent core 56 is covered with crepe paper or nonwoven fabric. For example, the lower surface may be covered with a liquid-impermeable sheet such as polyethylene (each of these materials becomes a component of the covering sheet). If necessary, the absorbent core 56 may be sandwiched between two upper and lower sheets or disposed only on the lower surface, but this is not desirable because it is difficult to prevent the movement of the superabsorbent polymer particles.

(Crotch exterior sheet)
A crotch outer sheet 12M exposed on the outer surface of the product is provided on the back surface side of the inner body 20. As the material of the crotch outer sheet 12M, the same material as the abdominal outer sheet 12F and the back outer sheet 12B can be used, but a material containing a higher-strength material or a deodorant, etc. A material different from the exterior sheet 12F and the back-side exterior sheet 12B may be used. Specifically, a spunbond nonwoven fabric, a meltblown nonwoven fabric, a pointbonded nonwoven fabric, an air-through nonwoven fabric, an air point nonwoven fabric, a spunlace nonwoven fabric, an SMS nonwoven fabric, or the like, each made of fibers such as PP, PP / PE, PP / PET, or the like, or What added the deodorizer etc. to this can be used.
A high body pressure is applied to the crotch outer sheet 12M when sitting. Therefore, a material having a high friction fastness (non-fluffing) property is preferable, and in particular, a material that can be evaluated as “◎” or “◯” in the following friction fastness test is preferably used.
(Friction fastness test)
The fastness to friction is measured by the following method in accordance with JIS L 0849. That is, a sheet piece for measuring the friction fastness of 250 mm × 25 mm is prepared, and the friction fastness on the outer surface side (the outer surface side of the interior body) of the measurement sheet piece is measured. For example, COLOR FASTNESS RUBING TESTER (manufactured by Tester Sangyo Co., Ltd., Model: AB-301) can be used for measuring the friction fastness. The measurement is performed using a friction tester type II and applying 50 vibrations. The measurement sheet piece obtained as a result of the test was visually compared with the limit sample, and {◎: No kinking and fluffing ○: No kinking and fuzzing △: With kinking and fuzzing ×: Nonwoven fabric breaks 4 Evaluate in stages.
The crotch outer sheet 12M may be a sheet provided with design elements by printing or coloring. When used in combination with the above-described design sheet, it is preferable to dispose the designs so that they do not overlap.
It is preferable to use a stretchable nonwoven fabric as the crotch outer sheet 12M and to extend and paste in the longitudinal direction of the inner body 20 because the fit of the crotch part is improved.
When the absorbent core 56 is an ultra-thin absorbent core having a fiber basis weight of 100 g / m ² or less and a high-absorbent polymer basis weight of 100 g / m ² or more, the absorption core 56 is not stiff so as not to reduce the ease of breaking. It is necessary to strengthen the stiffness in the crotch region. On the other hand, firmness is not necessary in the abdomen and back. Therefore, in such a form, it is preferable to use a sheet having high rigidity (roughness) as the crotch outer sheet 12M. Specifically, a sheet having a bending resistance measured by the Clark method (JISL1096 C method) and a sum of the MD direction and the CD direction of the sheet of 100 mm or more, preferably 150 mm or more may be used.
In the illustrated example, the crotch outer sheet 12M is sandwiched between the inner body 20 and the abdominal and dorsal exterior sheets 12F and 12B where the abdomen and dorsal exterior sheets 12F and 12B overlap the interior body 20. However, it is also possible to affix to the outside of the ventral and back side exterior sheets 12F and 12B. The crotch outer sheet 12M is affixed to the back surface of the interior body 20 and the inner or outer surfaces of the abdominal and back-side outer sheets 12F and 12B with a hot melt adhesive or the like.

  The present invention can be applied to a pants-type disposable diaper that is formed in a pants shape in advance.

It is a top view in the state where the diaper was developed showing the inner surface of a disposable diaper. It is a top view in the state where the diaper was developed showing the outer surface of a disposable diaper. FIG. 3 is a sectional view taken along line 3-3 in FIG. 1. FIG. 4 is a sectional view taken along the line 4-4 in FIG. 1. FIG. 5 is a sectional view taken along line 5-5 in FIG. 1. It is a top view in the state where a diaper was developed showing only a principal part of a disposable diaper with a size. It is a front view of a product state. It is a rear view of a product state.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 10 ... Interior body, 12 ... Exterior sheet, 12F ... Abdominal side exterior sheet, 12B ... Back side exterior sheet, 13 ... Back side main body part, 14 ... Back side extension part, 15 ... 1st elongate elastic elastic member, 16 ... 2nd elongate elastic expansion-contraction member, 20 ... Interior body, 56 ... Absorption core, 56F ... Absorption core front end part, 56B ... Absorption core rear end part, 56N ... Constriction part, 56d ... Deepest part.

Claims (4)

The abdomen exterior sheet covering the abdominal side of the wearer's waist and the back exterior sheet covering the back side, with the upper edge of the abdomen exterior sheet and the upper edge of the back exterior sheet aligned, A cylindrical waistline portion formed by joining the joint portions on both side edges in the width direction of the side exterior sheet and the joint portions on both side edges in the width direction of the back side exterior sheet;
The front end is connected to the inner surface in the width direction central portion of the ventral exterior sheet, the rear end is connected to the inner surface in the width direction central portion of the back exterior sheet, and passes from the back side to the ventral side through the crotch portion. And an interior body covering
The interior body includes a liquid-permeable surface sheet and an absorbent core formed by a fiber assembly,
In the pants-type disposable diaper in which the ventral side exterior sheet and the back side exterior sheet are not continuous on the crotch side and are separated from each other,
The absorbent core has a front end portion, a rear end portion, and a constricted portion that is narrower than the front end portion and the rear end portion, and is positioned between them.
The absorption core front end and absorption core rear end have a width of 100 to 200 mm,
The constricted portion has a deepest portion having a width of 50 to 100 mm at a predetermined portion in the middle in the front-rear direction, and the width of the absorbent core front end portion and the width of the absorbent core rear end portion are increased from the deepest portion toward the front side and the rear side, respectively. It has a shape that widens continuously or stepwise up to the width,
The deepest part is located within a range of 15 mm before and after the center in the front-rear direction,
The constricted part extends 100 mm or more on the front side and 40 mm or more on the rear side with respect to the center in the front-rear direction.
A pants-type disposable diaper characterized by that.   The pants-type disposable diaper according to claim 1, wherein a lower end of the belly side exterior sheet is positioned in the vicinity of a front end of the constricted portion, and a lower end of the back side exterior sheet is positioned in the vicinity of a rear end of the constricted portion.   When the crossing angle between the tangential direction at the front end of both side edges of the constricted portion and the front-rear direction is θ1, and the crossing angle between the tangential direction and the front-back direction at the rear ends of both side edges of the constricted portion is θ2, 10 degrees ≦ The pants-type disposable diaper according to claim 2, wherein the shape of the constricted portion is formed so as to satisfy a magnitude relationship of θ1 ≦ θ2 ≦ 60 degrees. Both side edges of the constricted part are a rear end side arcuate part located on the rear end side in the front-rear direction, a front end side arcuate part located on the front end side in the front-rear direction, and the rear end side arcuate part between them. It consists of a straight part connecting the front end and the rear end of the front end side arcuate part,
The radius of curvature of the rear end side arc-shaped portion is larger than that of the front end side arc-shaped portion, the linear portion is inclined so that the width of the constricted portion becomes wider toward the front side in the front-rear direction, and the rear end side circle The pants-type disposable diaper according to claim 3, wherein the deepest portion is located at an intermediate position in the front-rear direction of the arc-shaped portion.

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