JP7128616B2 - pad - Google Patents

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a pad to be worn on a disposable diaper, and more particularly to a pad provided with a rear weir behind a slit formed in an absorbent body.

Conventionally, the absorbent body of an absorbent article is composed of an inner absorbent body located on the wearer's body side and an outer absorbent body located on the side opposite to the body side of the wearer, and the inner absorbent body extends in the front-rear direction. Means for connecting the rear part of the slit through which liquid such as urine passes and the front part of the recess formed in the outer absorbent body and formed in the front-rear direction and through which liquid such as urine passes are communicated. (Patent document 1)

In addition, the absorbent body of the absorbent article is composed of an inner absorbent body and an outer absorbent body, and a slit extending in the front-rear direction formed in the inner absorbent body and allowing liquid to pass therethrough is provided at a predetermined interval in the front-rear direction. Means has been proposed for connecting an opening separated from the outer absorbent body to a front portion of a concave portion formed in the outer absorbent body and extending in the front-rear direction and through which liquid such as urine is passed. (Patent document 2)

JP 2011-125537 A JP 2016-7495 A

However, in the means of Patent Documents 1 and 2, when a large amount of liquid moves to the slit formed in the inner absorbent body through the liquid-permeable surface sheet of the absorbent article, the liquid overflows from the slit, There is a possibility that the overflowed liquid may not be absorbed by the outer absorbent body, move to both side edges and the rear edge in the width direction of the absorbent article, and leak to the outside from the both edges and the rear edge.

Therefore, an object of the present invention is to provide a weir projecting on the body surface side behind a slit extending in the front-rear direction formed in an absorbent body so that liquid overflowing from the slit is absorbed by the absorbent body. To provide a pad that prevents liquid from leaking to the outside and from returning to the side of the body.

Means for solving the above problems are as follows.
A first means is a pad comprising a liquid-permeable topsheet, a liquid-impermeable backsheet, and an absorbent body provided between the topsheet and the backsheet,
The absorbent body is composed of an inner absorbent body located on the body side and an outer absorbent body located on the side opposite to the body side, and extends in the front-rear direction with a predetermined gap in the width direction of the inner absorbent body. A slit is provided, side weirs are provided on both sides of the slit in the inner absorbent body to extend in the front-rear direction and protrude toward the body surface, and the inner absorbent body extends in the front-rear direction on the rear side of the slit. A rear dam portion projecting toward the body surface side is provided, and the rear portion of the side dam portion and the front portion of the rear dam portion are connected to each other. The portion between the side dams is formed in the shape of a first elliptical arc curve having a major axis in the front-rear direction, and the thickness of the portion of the inner absorbent body where the rear dams are provided in a side view corresponds to the thickness of the inner absorbent body. The side portion facing the slit of the side dam portion in a cross-sectional view taken in the vertical direction in the width direction is formed to be 200 to 400% of the thickness of the portion of the body where the side dam portion and the rear dam portion are not provided. is formed perpendicularly to the width direction, and in a side view, the side dam portion and the rear dam portion are formed to have the same thickness .

A second means is characterized in that, in the structure of the first means , the basis weight of the outer absorbent is set smaller than the basis weight of the inner absorbent.

According to the first means, the absorbent body is composed of an inner absorbent body located on the body side and an outer absorbent body located on the side opposite to the body side, and the inner absorbent body has a predetermined gap in the width direction. A slit extending in the direction of the body is provided, a side dam portion extending in the front-rear direction is provided on both sides of the slit in the inner absorbent body and protrudes toward the body surface side, and a rear side portion of the slit in the inner absorbent body is provided in the front-rear direction. A rear dam portion that extends to project toward the body surface is provided, and the rear portion of the side dam portion and the front portion of the rear dam portion are connected to each other. The portion between the side weir portions is formed in the shape of a first elliptical arc curve having a major axis in the front-rear direction, and in a side view, the thickness of the portion of the inner absorbent body where the rear weir portion is provided is equal to the thickness of the inner absorbent body. 200 to 400% of the thickness of the portion where the side dam portion and the rear dam portion are not provided, and in a cross-sectional view taken in the vertical direction in the width direction, the side portion facing the slit of the side dam portion is Since the side dam portion and the rear dam portion are formed to have the same thickness when viewed from the side, the liquid overflowing from the slit moves to the rear dam portion and moves to the rear dam portion. It is possible to prevent the liquid that is absorbed by the body part and overflows from the slit from leaking from the rear part of the pad or returning to the body surface side. In addition, the liquid overflowing from the slit and moving in the width direction can be absorbed by the side dams, thereby preventing the liquid from leaking from both sides in the width direction.

According to the second means, in addition to the effects of the first means, since the basis weight of the outer absorbent is made smaller than the basis weight of the inner absorbent, the outer absorbent can reach the outer absorbent through the slit of the inner absorbent. The moved liquid can be efficiently diffused over the entire area of the outer absorbent. In addition, liquid that has diffused into the outer absorbent body and cannot be absorbed by the outer absorbent body can be moved to the inner absorbent body and absorbed by the inner absorbent body.

FIG. 4 is a plan view of a pad in an unfolded state; It is a top view which shows only an important part. FIG. 2 is a cross-sectional view taken along the line AA of FIG. 1; FIG. 2 is a cross-sectional view taken along the line BB of FIG. 1; FIG. 4 is a cross-sectional view of a convex portion of the surface sheet; FIG. 10 is a plan view of the projections of the surface sheet; FIG. 4 is a plan view of the outer absorbent body; Fig. 2 is a plan view of the inner absorbent body of the first embodiment; In FIG. 8, (a) is a sectional view taken along line AA, (b) is a sectional view taken along line BB, and (c) is a sectional view taken along line CC. In FIG. 8, (a) is a cross-sectional view along DD, (b) is a cross-sectional view along EE, and (c) is a cross-sectional view along FF. FIG. 10 is a plan view of the inner absorbent core of the second reference embodiment; In FIG. 11, (a) is a sectional view taken along line AA, (b) is a sectional view taken along line BB, and (c) is a sectional view taken along line CC. In FIG. 11, (a) is a cross-sectional view along DD, (b) is a cross-sectional view along EE, and (c) is a cross-sectional view along FF. FIG. 11 is a plan view showing the inner surface of the inner absorbent core of the third reference embodiment; FIG. 14(a) is a sectional view taken along line AA, (b) is a sectional view taken along line BB, and (c) is a sectional view taken along line CC. In FIG. 14, (a) is a cross-sectional view along DD, (b) is a cross-sectional view along EE, (c) is a cross-sectional view along FF, and (d) is a cross-sectional view along GG.

<Pad of First Embodiment>
As shown in FIGS. 1 to 4, the pad of the first embodiment includes a crotch portion 11, a front body portion 10 extending to the front side of the crotch portion 11, and a back body portion 12 extending to the rear side of the crotch portion 11. is formed from The dimensions of each part can be determined as appropriate. For example, the length of the pad in the front-rear direction is 350-700 mm, the width in the width direction is 130-400 mm, the length of the front part 10 in the front-rear direction is 50-350 mm, and the crotch part. 11 can be formed to have a length of 10 to 150 mm in the front-rear direction, a length of the back portion 12 in the front-rear direction of 50 to 350 mm, and a narrowest width of the crotch portion 11 of 200 to 260 mm.

The pad comprises a liquid-impermeable backsheet 21, a liquid-permeable topsheet 22, an absorber 23 disposed between the backsheet 21 and the topsheet 22, and both sides of the topsheet 22 in the width direction. It is formed by the provided three-dimensional gathers 24 .

A back sheet 21 is provided outside the absorbent body 23 so as to protrude slightly from the outer peripheral edge of the absorbent body 23 . As the back sheet 21, in addition to a polyethylene film or the like, a moisture-permeable sheet can be used without impairing water impermeability in order to prevent stuffiness. The water-impervious/moisture-permeable sheet is a microporous sheet obtained by, for example, forming a sheet by melt-kneading an inorganic filler in an olefin resin such as polyethylene or polypropylene, and then stretching the sheet in a uniaxial or biaxial direction. can be used.

An exterior sheet 27 made of nonwoven fabric is provided outside the backsheet 21 so as to protrude slightly from the outer peripheral edge of the backsheet 21 . Various nonwoven fabrics can be used as the exterior sheet 27 . As material fibers constituting the nonwoven fabric, synthetic fibers such as olefin-based, polyester-based, and polyamide-based fibers such as polyethylene or polypropylene, regenerated fibers such as rayon and cupra, and natural fibers such as cotton can be used.

A surface sheet 22 is provided inside the absorbent body 23 . In the first embodiment, the width of the topsheet 22 in the width direction is narrower than the width of the absorber 23 . It can also be formed wider than it is wide. As the surface sheet 22, a perforated or non-perforated nonwoven fabric, a perforated plastic sheet, or the like is used. As material fibers constituting the nonwoven fabric, synthetic fibers such as olefin-based, polyester-based, and polyamide-based fibers such as polyethylene or polypropylene, regenerated fibers such as rayon and cupra, and natural fibers such as cotton can be used.

An intermediate sheet 25 is provided between the surface sheet 22 and the absorbent body 23 . As the intermediate sheet 25, materials with low water retention and high liquid permeability, such as various nonwoven fabrics and mesh films, can be used.

On both sides of the surface sheet 22 in the width direction, three-dimensional gathers 24 are provided. It is formed from a body portion that extends beyond the side of the direction to the side of the inner surface of the topsheet 22 . Further, front and rear end portions of the body portion in the front-rear direction are fixed to the surface sheet 22, and a center portion in the front-rear direction of the body portion is not fixed to the surface sheet 22 and stands inward. In addition, the fixed part of the three-dimensional gathers 24 is indicated by oblique lines in FIG.

The three-dimensional gathers 24 are formed from a double gather sheet 24A and an elongated elastic member 24B extending in the front-rear direction. A plastic sheet or a meltblown nonwoven fabric can be used as the material of the gather sheet 24A, but the nonwoven fabric can be water-repellent treated with silicone or the like in terms of feel to the skin. The elastic member 24B may be made of thread-like, cord-like, belt-like, or the like styrene-based rubber, olefin-based rubber, urethane-based rubber, ester-based rubber, polyurethane, polyethylene, polystyrene, styrene-butadiene, silicone, polyester, or the like. Commonly used materials can be used. In addition, as shown in FIG. 4, the elastic member 24B causes the three-dimensional gathers 24 to stand inward due to its elastic force.

At the front and rear ends of the pad in the front-rear direction, the top sheet 22 and the exterior sheet 27 are fixed to form the end flap portions EF, and at both side ends in the width direction of the pad, the gather sheet 24A and the exterior sheet 27 are fixed. A side flap portion SF is formed. Note that the absorber 23 does not extend to the end flap portion EF and the side flap portion SF.

The absorbent body 23 is composed of an inner absorbent body 23A located inside, which is the wearer's body side, and an outer absorbent body 23B located outside. The inner absorbent body 23A and the outer absorbent body 23B are basically made of a pile of pulp fibers, an aggregate of filaments such as cellulose acetate, or a non-woven fabric. , fixed or the like can be used. In addition, the inner absorbent body 23A and the outer absorbent body 23B are preferably wrapped with a wrapping sheet 26 such as crepe paper in order to prevent the superabsorbent polymer particles from falling off.

The inner absorbent body 23A is formed in a substantially rectangular shape having long sides in the front-rear direction. The length in the front-rear direction of the inner absorbent core 23A is formed to be 60 to 90% of the length in the front-rear direction of the outer absorbent core 23B. It is formed to 60 to 90% of the width. Moreover, it is preferable that the inner absorbent core 23A has a basis weight of 350 to 700 g/m ² larger than that of the outer absorbent core 23B. As a result, the liquid that diffuses into the outer absorbent core 23B and cannot be completely absorbed by the outer absorbent core 23B can be moved to the inner absorbent core 23A and absorbed by the inner absorbent core 23A.

As shown in FIG. 5, in the portion of the surface sheet 22 facing the slits 32 described later in the inner absorbent body 23A, a large number of protrusions 45 protruding inward are arranged in a zigzag fashion at predetermined intervals in the front-rear and width directions. formed in the shape of

As a result, as shown in FIG. 6, urine urinated at the urinating position Z on the topsheet 22 flows more in the front-rear direction or in the width direction than in the protrusions 45 protruding from the topsheet 22 and adjacent protrusions 45 . A large amount of urine urinated at the urination position Z flows into the slits 32 formed on both sides of the urination position Z, so that the fit of the crotch part 11 is suppressed while suppressing the decrease in the absorbable amount. It becomes excellent in the property and also excellent in the anti-backflow property.

The protrusions 45 can be formed by extruding the topsheet 22 from the outside to the inside using embossing. Moreover, the shape of the convex portion 45 can be formed in a circular shape, an elliptical shape, or a polygonal shape.

As shown in FIG. 7, the outer absorbent body 23B includes a front side portion 40 located in the front portion 10 of the pad, a constricted portion 41 located in the crotch portion 11 of the pad, and a rear portion located in the back portion 12 of the pad. A portion 42 is formed. The constricted portion 41 is formed by notching both sides in the width direction of the front side portion 40 and the rear side portion 42 of the outer absorbent body 23B in a substantially trapezoidal shape.

The minimum width of the constricted portion 41 is 50 to 65% of the width of the front side portion 40 and the rear side portion 42 . Further, when the front end of the outer absorbent body 23B is 0% and the rear end of the outer absorbent body 23B is 100%, the front end of the constricted portion 41 is arranged at 10 to 25%, and the rear end of the constricted portion 41 is arranged at 40 to 65%. %, and the minimum width portion of the constricted portion 41 is arranged at 25 to 30%. Also, the basis weight of the outer absorbent core 23B is preferably 250 to 450 g/m ² . As a result, the liquid that has moved to the outer absorbent body 23B through the slits 32 of the inner absorbent body 23A can be efficiently diffused throughout the outer absorbent body 23B.

As shown in FIGS. 8 to 10, the inner absorbent body 23A has a front side portion 30 extending from the front side portion 10 of the pad to a portion corresponding to the crotch portion 11, and a portion corresponding to the rear side portion 12 from the crotch portion 11. It is formed from an extending rear side 31 . The thickness of the rear side portion 31 is preferably 200 to 400% of the thickness of the front side portion 30 . The thickness of the front side portion 30 is formed to be 100 to 150% of the thickness of the outer absorbent body 23B. As a result, the liquid overflowing from the slits 32 of the front side portion 30 and moving in the width direction is absorbed by the side dam portions 35, and the liquid overflowing from the slits 32 of the front side portion 30 and moving rearward in the front-rear direction is absorbed by the rear dam. The liquid can be absorbed by the portion 36 and prevented from leaking from both sides in the width direction and from the rear portion in the front-rear direction.

At a portion of the front side portion 30 facing the constricted portion 41 of the outer absorbent body 23B, a substantially rectangular shape having long sides in the front-rear direction with a predetermined interval in the width direction is provided symmetrically with respect to the center in the width direction. A pair of slits 32 are formed. In addition, the rear side portion 31 is formed with side dam portions 35 extending in the front-rear direction on both sides of the slit 32 of the front side portion 30 in the width direction of the rear side portion 31 . A rear dam portion 36 is formed at a portion of the portion 30 on the rear side of the slit 32 .

In a side view, the front portion of the rear weir portion 36 is formed in an elliptical arc curve shape (a first elliptical arc curve shape in the claims) 37 . More specifically, the front portion of the rear weir portion 36 is an elliptical arc curve defined by Equation 1 below, where a is the radius in the front-rear direction and b is the radius in the vertical direction orthogonal to the front-rear direction. It is formed along the shape 37 . Note that y indicates the position in the front-rear direction, and z indicates the position in the vertical direction.
y2/ ^{a2 +} z2/b2= ¹ Equation ¹
However, the calculated value of a/b is set to 2 to 8, so that the liquid overflowing from the slit 32 is moved to the rear dam portion 36 without remaining between the slit 32 and the rear dam portion 36, and It can be absorbed by the weir portion 36 . If the calculated value of a/b is less than 2, the liquid overflowing from the slit 32 may stay between the slit 32 and the rear weir portion 36. If the calculated value of a/b is more than 8. As a result, the upper end portion of the rear dam portion 36 is entirely formed in an arc shape, and the length of the rear dam portion 36 in the front-rear direction may become longer than necessary.

In a cross-sectional view, the side portion of the side dam portion 35 facing the slit 32 is formed perpendicularly to the width direction.

<Pad of the second reference form>
Next, the pad of the second embodiment will be explained. The same members as those of the pad of the first embodiment are denoted by the same reference numerals, and description thereof is omitted.

As shown in FIGS. 11 to 13, the inner absorbent body 23A has a front side portion 30 extending from the front side portion 10 of the pad to a portion corresponding to the crotch portion 11, and a portion corresponding to the rear side portion 12 from the crotch portion 11. It is formed from an extending rear side 31 . The rear side portion 31 has side dam portions 35 extending in the front-rear direction formed on both sides of the slit 32 in the width direction of the front side portion 31 . A rear dam portion 36 is formed at a portion on the rear side of the slit 32 of .

In a side view, the front portion of the rear weir portion 36 is formed in an elliptical arc curve shape 37 . More specifically, the front portion of the rear weir portion 36 is an elliptical arc curve defined by Equation 1 below, where a is the radius in the front-rear direction and b is the radius in the vertical direction orthogonal to the front-rear direction. It is formed along the shape 37 . Note that y indicates the position in the front-rear direction, and z indicates the position in the vertical direction.
y2/ ^{a2 +} z2/b2= ¹ Equation ¹
However, the calculated value of a/b is set to 2 to 8, so that the liquid overflowing from the slit 32 is moved to the rear dam portion 36 without remaining between the slit 32 and the rear dam portion 36, and It can be absorbed by the weir portion 36 . If the calculated value of a/b is less than 2, the liquid overflowing from the slit 32 may stay between the slit 32 and the rear weir portion 36. If the calculated value of a/b is more than 8. As a result, the upper end portion of the rear dam portion 36 is entirely formed in an arc shape, and the length of the rear dam portion 36 in the front-rear direction may become longer than necessary.

In a cross-sectional view, the side portion of the side dam portion 35 facing the slit 32 is formed in an elliptical arc curve 38 . More specifically, the side portion of the side dam portion 35 facing the slit 32 is defined by the following equation 2, where c is the radius in the width direction and d is the radius in the vertical direction orthogonal to the width direction. It is formed along an arcuate curve 38 of an ellipse. Note that x indicates the position in the width direction, and z indicates the position in the vertical direction.
x2/c2 ⁺ z2/d2 ^{= 1} Equation ²
However, the calculated value of c/d is set to 2 to 4, so that the liquid overflowing from the slit 32 is not retained between the slit 32 and the side dam 35, and is moved to the side dam 35. It can be absorbed by the weir portion 35 . If the calculated value of c/d is less than 2, the liquid overflowing from the slit 32 may stay between the slit 32 and the side weir portion 35. If the calculated value of c/d is more than 4. As a result, the widthwise length of the side dam portion 35 may become longer than necessary.

<Pad of the third reference form>
Next, the pad of the third embodiment will be explained. The same members as those of the pad of the first embodiment are denoted by the same reference numerals, and description thereof is omitted.

As shown in FIGS. 14 to 16, the inner absorbent body 23A has a front side portion 30 extending from the front side portion 10 of the pad to a portion corresponding to the crotch portion 11, and a portion corresponding to the rear side portion 12 from the crotch portion 11. It is formed from an extending rear side 31 . The rear side portion 31 is formed to extend rearward in the front-rear direction from the rear end portion of the front side portion 10 in the front-rear direction over the entire width direction of the inner absorbent body 23A. In plan view, the slit 32 is formed to extend in the front-rear direction from the front-rear intermediate portion of the front side portion 30 to the front-rear intermediate portion of the rear weir portion 36 of the rear side portion 31 .

In a side view, the front portion of the rear weir portion 36 is formed in an elliptical arc curve 39 . More specifically, the front portion of the rear weir portion 36 is an elliptical arc curve defined by Equation 1 below, where a is the radius in the front-rear direction and b is the radius in the vertical direction orthogonal to the front-rear direction. It is formed along the shape 39 . Note that y indicates the position in the front-rear direction, and z indicates the position in the vertical direction.
y2/ ^{a2 +} z2/b2= ¹ Equation ¹
However, the calculated value of a/b is set to 2 to 8, so that the liquid overflowing from the slit 32 is moved to the rear dam portion 36 without remaining between the slit 32 and the rear dam portion 36, and It can be absorbed by the weir portion 36 . If the calculated value of a/b is less than 2, the liquid overflowing from the slit 32 may stay on the front side of the rear weir portion 36. If the calculated value of a/b is more than 8, the liquid may Since the upper end portion of the weir portion 36 is entirely formed in a circular arc shape, the length of the rear weir portion 36 in the front-rear direction may become longer than necessary.

Also, it is preferable to set the calculated value of a/b in Equation 1 to 5-8. As a result, the upper end portion 36A of the rear dam portion 36 is positioned above (inside) the upper end portion 32A of the slit 32, so that when the wearer is in a supine posture, the weight of the wearer is distributed to the rear dam portion. 36, the shape of the slit 32 extending in the front-rear direction can be maintained, and the liquid that has moved from the surface sheet 22 to the slit 32 can be efficiently moved to the rear dam portion 36.例文帳に追加

INDUSTRIAL APPLICABILITY The present invention is applicable to absorbent articles.

21 back sheet 22 top sheet 23 absorber 23A inner absorber 23B outer absorber 32 slit 32A upper end (second end)
35 side weir portion 36 rear weir portion 36A upper end (first end)
37 Arc curve shape of ellipse (Arc curve shape of first ellipse)
38 elliptical arc curve (second ellipse arc curve)
39 elliptical arc (3rd elliptical arc)

Claims (2)

A pad comprising a liquid-permeable topsheet, a liquid-impermeable backsheet, and an absorbent body provided between the topsheet and the backsheet,
The absorbent body is composed of an inner absorbent body located on the body surface side and an outer absorbent body located on the side opposite to the body surface,
Slits extending in the front-rear direction are provided in the inner absorbent body at predetermined intervals in the width direction,
side weirs extending in the front-rear direction and protruding toward the body surface are provided on both sides of the slit in the inner absorbent body,
A rear dam extending in the front-rear direction and protruding toward the body surface is provided on the rear side of the slit in the inner absorbent body,
connecting the rear portion of the side weir portion and the front portion of the rear weir portion;
In a side view, a portion between the side dam portions provided on both sides in the width direction of the front portion of the rear dam portion is formed in a first elliptical arc curve shape having a major axis in the front-rear direction,
In a side view, the thickness of the portion of the inner absorbent body where the rear dam portion is provided is 200 to 400% of the thickness of the portion of the inner absorbent body where the side dam portion and the rear dam portion are not provided. form,
In a cross-sectional view taken in the vertical direction in the width direction, the side portion of the side dam facing the slit is formed perpendicular to the width direction,
A pad characterized in that the side dam portion and the rear dam portion are formed to have the same thickness when viewed from the side . 2. The pad according to claim 1 , wherein said outer absorbent has a basis weight smaller than that of said inner absorbent.

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