JP7519757B2 - Absorbent articles - Google Patents

Description

The present invention relates to an absorbent article.

Absorbent articles such as disposable diapers, urine pads, and sanitary products are equipped with an absorbent body that absorbs excreted liquids such as urine and body fluids. For example, pulp or super absorbent polymer (SAP) is used as this type of absorbent body.

Furthermore, when an absorbent article is worn, moisture generated from urine, body fluids, etc. absorbed into the absorbent body tends to accumulate in the internal space of the absorbent article (the space formed between the wearer's skin and the skin-contacting surface of the absorbent article), and this moisture is undesirable because it can cause skin troubles such as skin rashes and can also cause discomfort such as stuffiness and stickiness.

Therefore, various proposals have been made to improve the breathability of absorbent articles in order to discharge moisture trapped in the internal space of the absorbent article to the outside when the absorbent article is worn (see, for example, Patent Document 1, etc.). For example, a disposable diaper is known in which an elastic member is used to shrink the outer layer sheet and the inner layer sheet in the circumferential direction of the waist to form pleats around the waist, allowing moisture to be discharged to the outside through the gap between the pleats and the wearer's skin.

Patent No. 5573806

As described above, various proposals have been made to improve the breathability of absorbent articles, but the reality is that there is a demand for absorbent articles with even higher breathability. Therefore, one of the objectives of the present invention is to provide an absorbent article with better breathability than conventional ones.

In order to solve the above problems, the absorbent article according to the present invention is an absorbent article having a front body region covering the wearer's abdomen, a rear body region covering the wearer's back, and a crotch region located between the front body region and the rear body region and in which an absorbent is disposed, and includes a torso opening in the front body region and the rear body region, through which the wearer's torso can be inserted, which includes a lower torso opening contraction portion including a plurality of elastic members extending in the torso direction from at least a portion corresponding to the wearer's hip bones, and contracts the torso opening in the torso direction, and an upper torso opening contraction portion including a plurality of elastic members extending in the torso direction between the opening edge of the torso opening and the lower torso opening contraction portion, and contracts the torso opening in the torso direction, and the distance between the plurality of elastic members in the lower torso opening contraction portion is greater than the distance between the plurality of elastic members in the upper torso opening contraction portion.

The spacing between the multiple elastic members in the lower contraction section of the torso opening may be 6.5 mm or more and 12 mm or less.

The lower contraction portion of the body opening may be provided in an area including a range of 20 mm to 40 mm from the edge of the opening.

The garment may further include an air passage forming sheet that is laminated so as to cover the skin-facing surfaces of the upper contracted portion of the torso opening and the lower contracted portion of the torso opening, and the air passage forming sheet is joined to the skin-facing surface by a plurality of joints that are provided intermittently along the torso circumference direction, and contraction of the upper contracted portion of the torso opening and the lower contracted portion of the torso opening causes the non-jointed areas located between the joints to bend and deform into a wavy shape, thereby forming an air passage.

The garment may further include an opening edge side contraction portion that includes multiple elastic members extending in the torso circumference direction along the opening edge between the opening edge and the torso opening upper contraction portion, and that contracts the torso opening in the torso circumference direction, and the spacing between the multiple elastic members in the opening edge side contraction portion may be greater than the spacing between the multiple elastic members in the torso opening upper contraction portion.

The bag may also be provided with a cover sheet that contains the elastic member of the upper contraction section of the torso opening in the section that forms the torso opening, and the cover sheet may be folded back at the edge of the opening, with continuous ventilation holes penetrating the cover sheet at the fold of the folded back section.

The above absorbent article provides better breathability than conventional products.

FIG. 1 is a perspective view of a pants-type disposable diaper according to an embodiment. FIG. 2 is an exploded perspective view of the diaper according to the embodiment. FIG. 3 is a schematic diagram showing a state in which the diaper according to the embodiment is laid out. FIG. 4 is a diagram illustrating an installation mode of an air passage-forming sheet in a diaper according to an embodiment. FIG. 5 is a diagram showing the locations of the joints where the air passage forming sheets are joined. FIG. 6 is a diagram showing the magnitude of contraction force in each contraction portion. FIG. 7 is a diagram illustrating pleats formed in the second contracted portion of the waist gathers and the third contracted portion of the tummy gathers. FIG. 8 is a schematic diagram showing a diaper according to a modified example in an unfolded state. FIG. 9 is a diagram illustrating pleats formed in the first and second contracted portions of the waist gathers and the third contracted portion of the tummy gathers. FIG. 10 is a diagram showing the ventilation holes formed at the opening edge of the waist opening when the waist gathers are contracted.

The following describes an embodiment of the present invention. The embodiment described below is an example of an embodiment of the present invention, and does not limit the technical scope of the present invention to the following aspects.

<Embodiment>
Fig. 1 is a perspective view of a pants-type disposable diaper (hereinafter simply referred to as "diaper") 1 according to an embodiment. Fig. 2 is an exploded perspective view of the diaper 1 according to the embodiment. Fig. 3 is a schematic diagram showing the diaper 1 according to the embodiment in an unfolded state. Fig. 3(A) shows a schematic diagram of the internal structure of the diaper 1 when unfolded, as viewed from the left side. Fig. 3(B) shows a schematic diagram of the planar structure of the diaper 1 when unfolded.

The directional terms used in this specification refer to the directions that correspond to the front, back, left and right of the wearer when the diaper 1 is worn by the wearer. For example, the left and right directions in this specification refer to the directions that correspond to the left and right of the wearer when the diaper 1 is worn by the wearer.

In addition, in this specification, the "front body region" of the diaper 1 means a portion that covers the wearer's abdomen (front of the body) when the diaper 1 is worn by the wearer. The "crotch region" of the diaper 1 means a portion that covers the wearer's crotch when the diaper 1 is worn by the wearer. The "rear body region" of the diaper 1 means a portion that covers the wearer's back (rear of the body) when the diaper 1 is worn by the wearer. In addition, in this specification, the "longitudinal direction" means a direction connecting the front body region and the rear body region of the diaper 1. In other words, the longitudinal direction of the diaper 1 coincides with the connecting direction in which the front body region, the crotch region, and the rear body region are connected. In addition, the "width direction" means a direction perpendicular to the longitudinal direction of the diaper 1.

In this embodiment, as an example of an absorbent article, a pants-type disposable diaper having a tubular structure with an opening for the wearer's abdominal circumference and a pair of left and right openings through which the wearer's left and right lower legs are inserted is exemplified, but the "absorbent article" in this specification is not limited to pants-type disposable diapers. "Absorbent article" includes various forms of absorbent articles that can cover the abdominal circumference and crotch area, such as a tape-type disposable diaper in which a tubular structure is formed by attaching a tape fixed near one end of a sheet-like member that covers the wearer's crotch (genitals) from the front body region to the rear body region to the other end of the sheet-like member.

As shown in Figures 1 to 3, the diaper 1 has a crotch region 1B that covers the crotch (genital area) of the wearer when worn, a front body region 1F that covers the wearer's abdomen, and a rear body region 1R that covers the wearer's back. The crotch region 1B is located between the front body region 1F and the rear body region 1R and is connected to the front body region 1F and the rear body region 1R, and the crotch region 1B is provided with an absorbent body 15 (absorbent body 8) that absorbs and retains liquid.

The diaper 1 in this embodiment is a pants-type disposable diaper, so that the left edge of the front body region 1F and the left edge of the rear body region 1R are joined together, and the right edge of the front body region 1F and the right edge of the rear body region 1R are joined together, resulting in the assembly shown in FIG. 1. As shown in FIG. 1, a torso opening (waist opening) 2T is formed by the upper edge of the front body region 1F and the upper edge of the rear body region 1R. In addition, the diaper 1 has a left lower leg opening 2L formed on the left side of the crotch region 1B, which is not joined, and a right lower leg opening 2R formed on the right side of the crotch region 1B. The left lower leg opening 2L and the right lower leg opening 2R are openings through which the wearer's legs are inserted when the diaper 1 is worn.

When the diaper 1 is put on with the wearer's left lower leg inserted through the left lower leg opening 2L, the wearer's right lower leg inserted through the right lower leg opening 2R, and the wearer's torso entering (passing through) the torso opening 2T, the front body region 1F contacts the wearer's abdomen and the rear body region 1R contacts the wearer's back, the crotch region 1B is placed against the wearer's crotch, and further, the left lower leg opening 2L and the right lower leg opening 2R are fixed to the wearer's body with the openings surrounding the wearer's thighs. By fixing the diaper 1 to the wearer's body in this manner, it becomes possible for the wearer to stand and walk while wearing the diaper 1.

In the diaper 1, an absorbent body 8 capable of absorbing and retaining liquid is mainly arranged near the crotch region 1B. In addition, in order to prevent the formation of gaps between the diaper 1 and the wearer's skin that could serve as a path for liquid to flow out, the diaper 1 is provided with three-dimensional gathers G1L, G1R, and waist gathers G2 at the left lower leg opening 2L, right lower leg opening 2R, and torso opening 2T, respectively. The three-dimensional gathers G1L, G1R, and waist gathers G2 are configured to adhere closely to the wearer's skin by the elasticity of the rubber thread, so that excretory liquid discharged from the wearer can be absorbed by the absorbent body 15 (absorbent body 8) without leaking out of the diaper 1.

As shown in Figures 2 and 3, the diaper 1 has cover sheets 4F, 4R which form the outer surface when the diaper 1 is worn by a wearer, and a pad cover sheet 6. The cover sheet 4F is
The pad cover sheet 6 is a sheet member that mainly forms the outer surface of the front body region 1F of the diaper 1. The pad cover sheet 6 is a sheet member that mainly forms the outer surface of the crotch region 1B of the diaper 1. The cover sheet 4R is a sheet member that mainly forms the outer surface of the rear body region 1R of the diaper 1.

The cover sheets 4F, 4R and the pad cover sheet 6 are provided, for example, to reinforce the outer surface of the diaper 1 and to improve the feel. In addition, the cover sheets 4F, 4R and the pad cover sheet 6 can be formed, for example, from a nonwoven fabric made of a liquid-impermeable thermoplastic resin in order to prevent leakage of excrement. Examples of liquid-impermeable thermoplastic resins include polyethylene (PE) and polypropylene (PP). In addition, the liquid-impermeable sheet may have a large number of fine holes of about 0.1 to several μm formed therein so as to exhibit liquid impermeability and moisture permeability.

The diaper 1 also has an inner cover sheet 5F laminated on the skin-facing side of the cover sheet 4F, and an inner cover sheet 5R laminated on the skin-facing side of the cover sheet 4R. In this specification, the "skin-facing side" means the side that faces the wearer's skin when the diaper 1 is worn by the wearer. As will be described in detail later, the inner cover sheet 5F is a sheet member that is bonded to the cover sheet 4F with a rubber thread, which is a linear elastic member, sandwiched between the cover sheet 4F and the inner cover sheet 4F. The inner cover sheet 5F is a sheet member having a shape and size corresponding to the folded portion 4F5, which will be described later, and the portion of the cover sheet 4F excluding the first waist region RW1 in the outer cover portion 4F10. The inner cover sheet 5R is a sheet member that is bonded to the cover sheet 4F with a rubber thread, which is a linear elastic member, sandwiched between the cover sheet 4R and the inner cover sheet 4R. The inner cover sheet 5R is a sheet member having a shape and size corresponding to the folded portion 4R5 (described later) and the portion of the cover sheet 4R excluding the first waist region RW1 of the outer cover portion 4R10.

The diaper 1 of this embodiment includes an absorbent body 15. The absorbent body 15 is held in a bridged state between the front body region 1F and the rear body region 1R, and is placed under the crotch of the wearer when the diaper 1 is worn, and absorbs and retains liquids such as urine excreted by the wearer. As shown in Figures 2 and 3, the absorbent body 15 includes a pad cover sheet 6, a back sheet 7, an absorbent body 8, a center sheet 9, side sheets 10L and 10R, etc., and is integrally formed by these.

The back sheet 7, absorbent body 8, and center sheet 9 are layered in this order on the skin-facing surface of the pad cover sheet 6. The pad cover sheet 6 has a length in the longitudinal direction that reaches from the wearer's front body through the crotch to the back body, and is a sheet member having a rectangular plane with a predetermined width in the width direction perpendicular to the longitudinal direction. The back sheet 7, absorbent body 8, and center sheet 9 are also sheet members having a rectangular plane like the pad cover sheet 6, and are layered in this order on the pad cover sheet 6 with their longitudinal directions coinciding with the longitudinal direction of the pad cover sheet 6.

The absorbent body 8 is a member for absorbing liquid such as urine and retaining the absorbed liquid. The absorbent body 8 is disposed between the liquid-impermeable back sheet 7 and the liquid-permeable center sheet 9. The absorbent body 8 may have a structure in which granular absorbent resin such as a hydrophilic superabsorbent polymer having a cross-linked structure capable of absorbing and retaining water is retained in the gaps between short fibers of cellulosic fibers such as pulp fibers, rayon fibers, or cotton fibers, or short fibers obtained by subjecting synthetic fibers such as polyethylene, polypropylene, or polyethylene terephthalate to hydrophilic treatment. As a result, when the absorbent body 8 absorbs liquid excreted from the wearer, the absorbent resin retained in the gaps in the short fibers swells to retain the liquid in the short fibers. The absorbent body 8 may have a single-layer structure consisting of one mat, or a laminated structure in which multiple mats are superimposed. The absorbent body 8 may have an appropriate shape according to the purpose. Examples of the shape of the absorbent body 8 include a rectangular shape, an hourglass shape with a narrowed center, and various other shapes.

The center sheet 9 is a sheet member that comes into direct contact with the skin of the wearer's crotch area and allows liquids such as urine to pass through to the absorbent body 8, and is arranged in a layered manner to cover the water-absorbing surface of the absorbent body 8. In this embodiment, the center sheet 9 is made of a highly flexible liquid-permeable material. Examples of liquid-permeable materials that form the center sheet 9 include woven fabric, nonwoven fabric, and porous film. The center sheet 9 may also be hydrophilic.

The backsheet 7 is a sheet member for preventing the liquid that has permeated the center sheet 9 and been absorbed by the absorbent 8 from leaking out to the outside of the diaper 1. For this reason, the backsheet 7 is made of a liquid-impermeable material. An example of a liquid-impermeable material for forming the backsheet 7 is a liquid-impermeable film made of polyethylene resin. The backsheet 7 may also be made of a microporous polyethylene film with numerous micropores formed therein in order to ensure breathability.

The pad cover sheet 6 is a member that reinforces the back sheet 7 and improves its feel against the skin, and is attached to the back sheet 7. Examples of materials that form the pad cover sheet 6 include woven fabric and nonwoven fabric. The pad cover sheet 6 may also be a nonwoven fabric or wet-laid nonwoven fabric made of a thermoplastic resin such as polyethylene, polypropylene, or polyester.

The side sheets 10L, 10R in the absorbent body 15 are elongated strip-shaped members for forming the above-mentioned three-dimensional gathers G1L, G1R. The side sheets 10L, 10R extend along the long sides of the center sheet 9. Rubber threads 10L1, 10R1 are bonded to the side sheets 10L, 10R along the longitudinal direction. When the left edge 4F7 of the cover sheet 4F forming the left edge of the front body region 1F and the left edge 4R7 of the cover sheet 4R forming the left edge of the back body region 1R are joined together, and the right edge 4F8 of the cover sheet 4F forming the right edge of the front body region 1F and the right edge 4R8 of the cover sheet 4R forming the right edge of the back body region 1R are joined together to assemble the diaper 1 shown in FIG. 1, the side sheets 10L, 10R are pulled in the longitudinal direction by the contraction force of the rubber threads 10L1, 10R1, and rise from the center sheet 9 along the fold lines 10L2, 10R2.

This forms three-dimensional gathers G1L, G1R that prevent liquid from leaking out from the left lower leg opening 2L and the right lower leg opening 2R. The method for joining the side edges of the cover sheets 4F, 4R is not particularly limited, but examples include heat sealing, high-frequency sealing, and ultrasonic sealing. The absorbent body 15 extends from the front body region 1F to the back body region 1R.

Next, the detailed structure of the diaper 1 will be described. As shown in FIG. 3, the tip side of the cover sheet 4F is folded inward at the fold line 4F6 to form a fold-back portion 4F5. Hereinafter, the portion of the cover sheet 4F excluding the fold-back portion 4F5 will be referred to as the exterior cover portion 4F10. The exterior cover portion 4F10 of the cover sheet 4F forms the outer surface of the diaper 1. The fold line 4F6 of the cover sheet 4F forms the trunk opening edge 4F9 of the trunk opening 2T when the diaper 1 is assembled.

The folded-back portion 4F5 of the cover sheet 4F has the first rubber thread 4F1 in a stretched state disposed between the folded-back portion 4F5 and the outer cover portion 4F10.
The tip side of the inner cover sheet 5F is adhered to one end of the absorbent body 8 in a state where it is overlapped with the outer cover part 4F10, with one end side in the longitudinal direction of the inner cover sheet 5F, the pad cover sheet 6, the back sheet 7, and the absorbent body 8 being sandwiched between the layers of the outer cover part 4F10. In this specification, the manner in which one member and another member are expressed as being overlapped is not limited to the manner in which the members are overlapped in a state in which they are in full contact with each other, but is a concept that includes the manner in which a part of one member and the whole of the other member are overlapped, or the manner in which parts of one member and the other member are overlapped.

Furthermore, as shown in Fig. 3, the second rubber thread 4F2, the third rubber thread 4F3, and the fourth rubber thread 4F4 are arranged in this order from the fold-back line 4F6 side between the outer cover portion 4F10 and the inner cover sheet 5F in the cover sheet 4F, and are bonded in a sandwiched state between the outer cover portion 4F10 and the inner cover sheet 5F. As shown in Fig. 3, the first rubber thread 4F1 to the fourth rubber thread 4F4 in the cover sheet 4F are each arranged in parallel in groups of multiples, and all of them extend along the width direction (waist direction) of the cover sheet 4F.

On the other hand, the cover sheet 4R also has a folded-back portion 4R5 formed by folding back the tip side inward at the folding line 4R6. Hereinafter, the portion of the cover sheet 4R excluding the folded-back portion 4R5 is referred to as the outer cover portion 4R10. The outer cover portion 4R10 of the cover sheet 4R forms the outer surface of the diaper 1. The folding line 4R6 of the cover sheet 4R forms the torso opening edge 4R9 of the torso opening 2T when the diaper 1 is assembled. The folded-back portion 4R5 of the cover sheet 4R has the first rubber thread 4R1 in a stretched state disposed between the outer cover portion 4R10. The tip side of the folded-back portion 4R5 of the cover sheet 4R is bonded to the other end of the absorbent body 8 in a state of being overlapped with the other end of the absorbent body 8 with the other end of the inner cover sheet 5R, the pad cover sheet 6, the back sheet 7, and the absorbent body 8 sandwiched between the outer cover portion 4R10.

Furthermore, as shown in Fig. 3, the second rubber thread 4R2, the third rubber thread 4F3, and the fourth rubber thread 4R4 are arranged in this order from the fold-back line 4R6 side between the outer cover portion 4R10 and the inner cover sheet 5R in the cover sheet 4R, and are bonded in a sandwiched state between the outer cover portion 4R10 and the inner cover sheet 5R. As shown in Fig. 3, the first rubber thread 4R1 to the fourth rubber thread 4R4 in the cover sheet 4R are each arranged in parallel in groups of multiples, and all of them extend along the width direction (waist direction) of the cover sheet 4R.

Hereinafter, the area in the cover sheet 4F, 4R of the diaper 1 where the first rubber threads 4F1, 4R1 and the second rubber threads 4F2, 4R2 are arranged will be referred to as the "waist area RW". The waist area RW of the diaper 1 is located near the waist opening edges 4F9, 4R9 that form the waist opening 2T, and is the area where the waist gathers G2 are formed. Furthermore, within the waist area RW, the area where the first rubber threads 4F1, 4R1 are arranged will be referred to as the "first waist area RW1" (first area), and the area where the second rubber threads 4F2, 4R2 are arranged will be referred to as the "second waist area RW2" (second area).

The area of the cover sheet 4F, 4R of the diaper 1 where the third rubber threads 4F3, 4R3 and the fourth rubber threads 4F4, 4R4 are arranged is called the "tummy area RT." The tummy area RT is an area located below the waist area RW. Within the tummy area RT, the area where the third rubber threads 4F3, 4R3 are arranged is called the "first tummy area RT1," and the area where the fourth rubber threads 4F4, 4R4 are arranged is called the "second tummy area RT2."

Here, the first elastic threads 4F1, 4R1 in the first waist region RW1 are stretched during the assembly process of the diaper 1, and then the outer cover portion 4F
Similarly, the second rubber thread 4F2, 4R2 in the second waist region RW2 and the third rubber thread 4F3, 4R3 and the fourth rubber thread 4F4, 4R4 in the tummy region RT are applied with adhesive in a stretched state during, for example, the assembly process of the diaper 1, and then are sandwiched between the outer cover portion 4F10, 4R10 of the cover sheet 4F, 4R and the inner cover sheet 5F, 5R to be bonded between these layers.

When the first elastic thread 4F1, 4R1 of the first waist region RW1, which is sandwiched and bonded in a stretched state between the outer cover portion 4F10, 4R10 and the inner cover sheet 5F, 5R of the cover sheet 4F, 4R, contracts, the parts of the outer cover portion 4F10, 4R10 and the folded-back portion 4F5, 4R5 that correspond to the first waist region RW1 bend continuously in a pleated shape, forming a first contraction portion S1 that contracts the first waist region RW1 in the girth direction.

In the second waist region RW2, when the second rubber thread 4F2, 4R2, which is sandwiched and adhered in a stretched state between the layers of the outer cover portion 4F10, 4R10 and the inner cover sheet 5F, 5R, contracts, the portions of the outer cover portion 4F10, 4R10 and the inner cover sheet 5F, 5R that correspond to the second waist region RW2 are continuously flexed in pleats, forming a second contraction portion S2 (an example of the "upper contraction portion of the waist opening" as referred to in this application) that contracts the second waist region RW2 in the waist circumference direction.

In this embodiment, the waist gather G2 is formed mainly by the first contraction portion S1 formed in the first waist region RW1 and the second contraction portion S2 formed in the second waist region RW2. The waist gather G2 improves the fit of the diaper 1 around the wearer's waist by the contraction force of the first rubber threads 4F1, 4R1 and the second rubber threads 4F2, 4R2. In the first contraction portion S1 of the waist gather G2, a plurality of first rubber threads 4F1, 4R1 are arranged parallel to each other at a constant interval A1. In addition, in the second contraction portion S2 of the waist gather G2, a plurality of second rubber threads 4F2, 4R2 are arranged parallel to each other at a constant interval A2. Note that the interval between the rubber threads here means the distance between adjacent rubber threads in the longitudinal direction of the diaper (the direction connecting the body region and the rear body region).

In addition, in this embodiment, the first rubber threads 4F1, 4R1 in the first waist region RW1 and the second rubber threads 4F2, 4R2 in the second waist region RW2 extend across the entire width of the cover sheets 4F, 4R. Therefore, after the diaper 1 is completed, the first rubber threads 4F1, 4R1 and the second rubber threads 4F2, 4R2 form a substantially annular elastic member that runs around the waist opening 2T. In other words, after the diaper 1 is completed, the waist gathers G2 (first contraction portion S1, second contraction portion S2) are formed across the entire circumference in the waist direction.

In the first tummy region RT1, when the third rubber thread 4F3, 4R3, which is sandwiched and bonded in a stretched state between the outer cover portion 4F10, 4R10 of the cover sheet 4F, 4R and the inner cover sheet 5F, 5R, contracts, the portions of the outer cover portion 4F10, 4R10 of the cover sheet 4F, 4R and the inner cover sheet 5F, 5R corresponding to the first tummy region RT1 are continuously bent in a pleated shape, forming a third contraction portion S3 (an example of the "lower contraction portion of the waist opening" in this application) that contracts the first tummy region RT1 in the waist direction. The third contraction portion S3 is an area that fits near the height of the wearer's hip bones when the diaper 1 is worn, and is provided in an area including a range of 20 mm to 40 mm from the opening edge of the waist opening 2T.

Also, in the second tummy region RT2, when the fourth rubber thread 4F4, 4R4 sandwiched and bonded in a stretched state between the outer cover portion 4F10, 4R10 of the cover sheet 4F, 4R and the inner cover sheet 5F, 5R contracts, the portions of the outer cover portion 4F10, 4R10 of the cover sheet 4F, 4R and the inner cover sheet 5F, 5R corresponding to the second tummy region RT2 continuously bend in a pleated shape, forming a fourth contracted portion S4 that contracts the second tummy region RT2 in the waist direction. In this embodiment, the tummy gather G3 is formed mainly by the third contracted portion S3 formed in the first tummy region RT1 and the fourth contracted portion S4 formed in the second tummy region RT2. The tummy gathers G3 improve the fit of the diaper 1 around the lower abdomen of the wearer, for example, by the contraction forces of the third elastic threads 4F3, 4R3 and the fourth elastic threads 4F4, 4R4.

The third elastic threads 4F3, 4R3 arranged in the third contraction portion S3 of the tummy gather G3 are arranged parallel to each other with a constant interval A3 between them. The fourth elastic threads 4F4, 4R4 arranged in the fourth contraction portion S4 of the tummy gather G3 are also arranged parallel to each other with a constant interval A4 between them. In this embodiment, the interval A3 between the third elastic threads 4F3, 4R3 in the third contraction portion S3 of the tummy gather G3 is set to a dimension larger than the interval A2 between the second elastic threads 4F2, 4R2 in the second contraction portion S2 of the waist gather G2. This makes it easier to widen the third contraction portion S3 of the tummy gather G3, which is the portion that comes into contact with the hip bone of the wearer, than the second contraction portion S2 of the waist gather G2 when the waist opening 2T is widened to put on the diaper 1.

In this embodiment, the rubber threads 4F1, 4R1, 4F2, 4R2, 4F3, 4R3, 4F4, and 4R4 are extended along the width direction (waist circumference direction) of the cover sheets 4F and 4R to form the first contraction section S1 to the fourth contraction section S4. However, other materials and shapes may be used as long as they are linear elastic members, and are not limited to rubber threads. In this specification, the term "linear" refers to an elongated shape that extends in a specific direction, and includes belt-like and rectangular shapes. Examples of materials for the rubber threads include natural rubber and synthetic rubber, but the material is not limited to a specific material.

Next, the air passage forming sheets 11F, 11R of the diaper 1 will be described. As shown in Figs. 2 and 3, the diaper 1 has folded-back portions 4F5, 4R5 of the cover sheets 4F, 4R, and air passage forming sheets 11F, 11R laminated to the folded-back portions 4F5, 4R5 in the longitudinal end regions of the pad cover sheet 6, center sheet 9, etc. of the absorbent body 15. The air passage forming sheets 11F, 11R form the skin contact surfaces of the waist gathers G2 and tummy gathers G3 of the diaper 1. The "skin contact surface" refers to the surface that directly contacts the wearer's skin when the diaper 1 is worn, i.e., the innermost surface of the diaper 1.

Figure 4 is a diagram for explaining the installation mode of the air passage forming sheets 11F, 11R of the diaper 1 according to the embodiment. (A) of Figure 4 is a diagram showing the first contraction portion S1 of the waist gather G2 as viewed from the internal space side of the diaper 1. Also, (B) of Figure 4 is a diagram showing a schematic diagram of the internal structure of the first contraction portion S1 of the waist gather G2 as viewed from the side of the diaper 1. Also, (C) of Figure 4 is a diagram showing the first contraction portion S1 of the waist gather G2 as viewed from above the diaper 1 (i.e., the direction of the arrow A in (B)). For convenience, (A) and (C) of Figure 4 show the state before the first contraction portion S1 of the waist gather G2 is contracted. Also, (D) of Figure 4 is a diagram showing the state after contraction as viewed from above the first contraction portion S1 of the waist gather G2.

The air passage forming sheets 11F, 11R are disposed at least in the areas corresponding to the first contracted portion S1, the second contracted portion S2 and the third contracted portion S3, and are joined to the longitudinal end regions and the folded-back portions 4F5, 4R5 of the pad cover sheet 6 through the joints indicated by the symbol S. Fig. 5 is a diagram showing the positions of the joints S that join the air passage forming sheets 11F, 11R. In this embodiment, the cover sheet 4 formed of a thermoplastic resin is
The folded-back portions 4F5, 4R5 of the cover sheets 4F, 4R and the air passage forming sheets 11F, 11R superposed on the pad cover sheet 6 are joined by ultrasonic welding to form the joints S. As shown in Fig. 4(A) and Fig. 5, a plurality of joints S are intermittently arranged along the longitudinal direction perpendicular to the waist circumference direction (width direction) from the waist opening end edges 4F9, 4R9 of the cover sheets 4F, 4R, forming linear joints SL extending in the longitudinal direction of the diaper 1. In other words, one linear joint SL is formed as a collection of a plurality of joints S intermittently arranged along the longitudinal direction of the diaper 1. Here, "intermittently" means that the joints are arranged discontinuously or intermittently.

As shown in FIG. 4A, in the first contraction portion S1 of the waist gather G2, a plurality of linear joints SL are intermittently arranged along the waist circumference direction (width direction) of the cover sheets 4F, 4R. In the example shown in FIG. 4A, the linear joints SL are arranged parallel to each other, and the distance between the linear joints SL is set to be alternatingly large and small. In other words, the linear joints SL are intermittently arranged in such a manner that a double line formed by a set of linear joints SL is arranged at equal intervals in the waist circumference direction (width direction). Note that FIG. 3A illustrates the range in which the linear joints SL extend in the longitudinal direction of the diaper 1 by hatching. As shown in the figure, the linear joints SL extend across the first waist region RW1 in which the first contraction portion S1 is formed and the second waist region RW2 in which the second contraction portion S2 is formed.

The ultrasonic bonding of the air passage forming sheets 11F, 11R in the first contraction portion S1 and the second contraction portion S2 of the waist gather G2 and the third contraction portion S3 of the tummy gather G3 is performed in a state in which the first rubber thread 4F1, 4R1 and the second rubber thread 4F2, 4R2 of the waist gather G2 and the third rubber thread 4F3, 4R3 and the fourth rubber thread 4F4, 4R4 of the tummy gather G3 are in an elongated state. After the bonding of the air passage forming sheets 11F, 11R in the first contraction portion S1 and the second contraction portion S2 of the waist gather G2 and the third contraction portion S3 of the tummy gather G3 is completed, the elongated state of the first rubber thread 4F1, 4R1, the second rubber thread 4F2, 4R2, the third rubber thread 4F3, 4R3 and the fourth rubber thread 4F4, 4R4 sandwiched and fixed between the sheet layers is released. As a result, the waist gathers G2 and the tummy gathers G3 shrink, narrowing the distance between the linear joints SL in the air passage forming sheets 11F, 11R. As a result, the non-jointed areas 110 located between the linear joints SL in the air passage forming sheets 11F, 11R bend and deform into a wavy shape.

As a result, the non-bonded regions 110 located between the linear joints SL are separated, forming a first air passage 111 surrounded by the folded-back portions 4F5, 4R5, etc. and the non-bonded regions 110 of the air passage forming sheets 11F, 11R, as shown in FIG. 4D. Also, a second air passage 112 is formed on the skin contact surface 11a side of the air passage forming sheets 11F, 11R. The two-dot chain line indicated by the symbol SS in FIG. 4D shows the skin surface that contacts the air passage forming sheets 11F, 11R when the diaper 1 is worn by a wearer as an imaginary line. The second air passage 112 is formed as a gap formed between the skin contact surface 11a of the air passage forming sheets 11F, 11R and the wearer's skin when the diaper 1 is worn by the wearer. Moisture in the internal space of the diaper 1 can be discharged to the outside through the first air passage 111 and the second air passage 112 formed in the first contracted portion S1 and the second contracted portion S2 of the waist gather G2 and the third contracted portion S3 of the tummy gather G3. The first air passage 111 is an air passage through which moisture that has permeated the air passage forming sheets 11F, 11R from the internal space of the diaper 1 passes. On the other hand, the second air passage 112 is an air passage that directly connects the internal space of the diaper 1 to the external space, and allows moisture inside the diaper 1 to be discharged more smoothly.

As shown in FIG. 4D, after the waist gathers G2 and the tummy gathers G3 are contracted, relatively large first pleats 41 and relatively small second pleats 42 that form the first contracted portion S1 are formed alternately.
In the case of the 11F and 11R, the relatively large first pleats 113 and the relatively small second pleats 114 are formed alternately. This is because the intervals between the linear joints SL are set to be alternately large and small. That is, the large first pleats 41 and 113 are formed by a pair of linear joints SL with a wide interval, and the small second pleats 42 and 114 are formed by a pair of linear joints SL with a narrow interval.

Here, the first pleats 113 of the air passage forming sheets 11F, 11R that have been bent and deformed into a corrugated shape cooperate with the first pleats 41 that form the first contracted portion S1 to ensure a large first air passage 111. On the other hand, the second pleats 114 of the air passage forming sheets 11F, 11R cooperate with the second pleats 42 that form the first contracted portion S1 to form the first air passage 111, and also properly separate the first pleats 113 adjacent in the waist direction (width direction), thereby contributing to ensuring the ventilation cross section of the second air passage 112. In this embodiment, the flute structure formed by the air passage forming sheets 11F, 11R that deform into a wavy shape following the contraction of the waist gathers G2 and the tummy gathers G3 is provided on the skin contact surface side of the first contraction portion S1 and the second contraction portion S2 of the waist gathers G2 and the third contraction portion S3 of the tummy gathers G3, so that moisture inside the diaper 1 can be efficiently discharged to the outside through the first air passage 111 and the second air passage 112. In addition, in this embodiment, the linear joint SL is formed as a collection of multiple joints S that are intermittently arranged along the longitudinal direction of the diaper 1, so that adjacent first air passages 111 are connected to each other through the gaps between the joints S. Therefore, the breathability between adjacent first air passages 111 is improved, and the wearer is less likely to feel a localized stuffiness.

Furthermore, the air passage forming sheets 11F, 11R in this embodiment are provided with a large number of fine ventilation holes 11F1, 11R1 for ventilation. Here, the ventilation hole means an opening that communicates the space on one side of the sheet with the space on the other side, and the shape is not particularly limited. Therefore, the ventilation hole 11F1, 11R1 can be, for example, an opening having a shape such as a circle, an ellipse, a polygon (triangle, square, etc.). The formation of the ventilation hole 11F1, 11R1 in the air passage forming sheets 11F, 11R does not mean that the air passage forming sheets 11F, 11R are made of a material that has no air permeability, and the air passage forming sheets 11F, 11R may be made of a material that has air permeability or a material that does not have air permeability. The air passage forming sheets 11F, 11R are preferably made of a material that has air permeability and liquid permeability, but may be made of, for example, a material that has no air permeability. The size and number of the ventilation holes 11F1, 11R1 are not particularly limited, but for example, if the opening area is 0.5 to ¹⁰ mm2, it is preferable to form about 5 to 200 holes.

And, as a result of thorough investigation, the inventors have discovered that by making the distance A3 between the third rubber threads 4F3, 4R3 forming the third contraction portion S3 larger than the distance A2 between the second rubber threads 4F2, 4R2 forming the second contraction portion S2, the third contraction portion S3 is guided to the wearer's hip bone so that the diaper 1 is properly worn, and that the pump effect caused by the deformation due to the expansion and contraction of the first air passage 111 and the second air passage 112 in the third contraction portion S3, which expands and contracts in accordance with the wearer's movements, promotes the expulsion of moisture from inside the diaper 1. In particular, by setting the gap A3 to 6.5 mm or more and 12 mm or less, the degree to which the air passage forming sheets 11F, 11R are constrained by the third rubber threads 4F3, 4R3 is reduced compared to when the gap A3 is set to a narrower gap, and the reduced degree of constraint increases the size of the first air passage 111 and the second air passage 112, thereby enhancing the pump effect in the third contraction section S3.

Fig. 6 is a diagram showing the magnitude of the contraction force in each contraction portion. The white arrows in Fig. 6 indicate the magnitude of the contraction force. In the diaper 1 of this embodiment, the distance A3 between the third rubber threads 4F3, 4R3 forming the third contraction portion S3 is larger than the distance A2 between the second rubber threads 4F2, 4R2 forming the second contraction portion S2. Therefore, in the diaper 1 of this embodiment, as shown in Fig. 6, the contraction force of the third contraction portion S3 is weaker than the contraction forces of the first contraction portion S1 and the second contraction portion S2. The third contraction portion S3 is designed to abut against the hip bone of the wearer when the diaper 1 is worn in a proper position, and the hip bone is the widest part of the wearer's waist as shown in Fig. 6. The third contraction portion S3 is provided in a region including a range of 20 mm to 40 mm from the opening edge of the torso opening 2T so as to match the range of 20 mm to 40 mm, which is the distance from the first joint and the second joint of the index finger of a general adult to the finger tip. Therefore, in the diaper 1 of this embodiment in which the contraction force of the third contraction portion S3 is weaker than the contraction forces of the first contraction portion S1 and the second contraction portion S2, when the torso opening 2T is opened by hand when putting on the diaper 1 on a wearer, the third contraction portion S3 is the widest, so that the second joint of the index finger of the person putting on the diaper 1 is placed near the opening edge of the torso opening 2T, the first contraction portion S1 and the second contraction portion S2 are located between the first joint and the second joint of the index finger, and the tip of the index finger is caught by the third contraction portion S3, which is easier to open than the first contraction portion S1 and the second contraction portion S2. The diaper 1 is put on so that the hip bone, which has the widest width in the wearer's waist, naturally fits into the widest third contraction portion S3. As a result, the diaper 1, which is designed so that the third contraction portion S3 abuts against the hip bone of the wearer, is worn in a proper position on the wearer.

7 is a diagram illustrating pleats formed in the second contracted portion S2 of the waist gather G2 and the third contracted portion S3 of the tummy gather G3. The pleats formed between the rubber threads are more constrained by the rubber threads at locations closer to the rubber threads. Therefore, the first pleats 113 and the second pleats 114 of the air passage forming sheets 11F, 11R formed between the third rubber threads 4F3, 4R3 are less constrained than the first pleats 113 and the second pleats 114 of the air passage forming sheets 11F, 11R formed between the second rubber threads 4F2, 4R2 arranged at a distance A2 narrower than the distance A3 between the third rubber threads 4F3, 4R3. Therefore, the pleats formed in the third contracted portion S3 of the tummy gather G3 are larger than the pleats formed in the second contracted portion S2 of the waist gather G2. Therefore, in the diaper 1 according to the present embodiment, the first air passage 111 and the second air passage 112 formed by the first pleat 113 and the second pleat 114 are larger in the tummy gather G3 than in other parts. Since the tummy gather G3 is a part that expands and contracts with the wearer's movements, the first air passage 111 and the second air passage 112 formed in the tummy gather G3 perform a pump function by expanding and contracting in conjunction with the wearer's movements, and moisture in the diaper 1 is more smoothly discharged. In addition, the hip bone part of the wearer is the part with the largest width in the wearer's waist circumference, and is also a part that is likely to come into contact with things around the wearer and be subjected to external pressure, so that the tummy gather G3 corresponding to the hip bone part is expected to have a pump effect by expanding and contracting the first air passage 111 and the second air passage 112 due to external pressure. This makes it possible to create a more comfortable environment in the internal space of the diaper 1.

In addition, with the diaper 1 according to this embodiment, the pleats formed in the tummy gathers G3 are larger than the pleats formed in the second contraction portion S2 of the waist gathers G2, so that the pleats in the tummy gathers G3 stand out more than the others, and the wearer can be naturally made aware that the tummy gathers G3 are abutting the hip bone, which is the widest part of the wearer's waist. In addition, since the pleats formed in the tummy gathers G3 are larger than the pleats formed in the second contraction portion S2 of the waist gathers G2, the tummy gathers G3 are more likely to spread when the waist opening 2T is widened. Therefore, when the diaper 1 is put on, the diaper 1 is more likely to be naturally aligned so that the part of the tummy gathers G3, which is relatively easy to spread, abuts the hip bone.

The diaper 1 of the above embodiment may be modified as follows. Fig. 8 is a schematic diagram showing a diaper 1 according to the modified embodiment in an unfolded state. In this modified embodiment, the distance A1 between the first rubber threads 4F1, 4R1 in the first contracted portion S1 is set to a dimension larger than the distance A2 between the second rubber threads 4F2, 4R2 in the second contracted portion S2, so that the first contracted portion S1 ensures a moisture discharge function for discharging moisture in the internal space of the diaper 1 to the outside and a function for making it easy to widen the waist opening 2T. Meanwhile, the second contracted portion S2 of the waist gather G2 has a higher contraction force in the waist direction than the first contracted portion S1, so that the second contracted portion S2 ensures a position retention function (slip-down prevention function) for preventing the diaper 1 from slipping down when worn.

9 is a diagram illustrating the pleats formed in the first contracted portion S1 and the second contracted portion S2 of the waist gather G2 and the third contracted portion S3 of the tummy gather G3. As described above, the pleats formed between the rubber threads are more constrained by the rubber threads at locations closer to the rubber threads. Therefore, the first pleats 113 and the second pleats 114 of the air passage forming sheets 11F, 11R formed between the first rubber threads 4F1, 4R1 are less constrained than the first pleats 113 and the second pleats 114 of the air passage forming sheets 11F, 11R formed between the second rubber threads 4F2, 4R2 arranged at a distance A2 narrower than the distance A1 between the first rubber threads 4F1, 4R1. Therefore, the pleats formed in the first contracted portion S1 of the waist gather G2 are larger than the pleats formed in the second contracted portion S2 of the waist gather G2. Therefore, in the diaper 1 according to this modification, the first air passage 111 and the second air passage 112 formed by the first pleat 113 and the second pleat 114 in the first contraction portion S1 of the waist gather G2 are larger in size than in the second contraction portion S2. And since the waist gather G2 is a portion that expands and contracts due to the wearer's movements, the first air passage 111 and the second air passage 112 each have a pump function at two locations, the first contraction portion S1 of the waist gather G2 and the tummy gather G3, which allows moisture inside the diaper 1 to be discharged more smoothly (double pump function). This makes it possible to create a more comfortable environment in the interior space of the diaper 1.

Incidentally, the above-mentioned diaper 1 may have air holes formed by linearly cutting fine slits at the folding lines 4F6, 4R6 of the cover sheets 4F, 4R arranged in a dotted line. In this case, it is preferable that the dotted air holes formed at the folding lines 4F6, 4R6 are large enough that the wearer's fingers cannot enter. For example, if the air holes are formed by slits with a length of 5 mm or less, the fingers of an average infant cannot enter them. In addition, it is preferable that the folding lines 4F6, 4R6 have a predetermined interval between the slits forming the dotted air holes so that the cover sheets 4F, 4R are not torn at the folding lines 4F6, 4R6 under normal use conditions of the diaper 1. Although it depends on the strength of the material constituting the cover sheets 4F, 4R, if the sheet has a basis weight of about 8 to 50 g/ ^m2 that does not impair the elasticity and wearing comfort required for the waist circumference, the interval between the slits is preferably 2 mm or more.

Figure 10 is a diagram showing the ventilation holes formed at the opening edge of the waist opening 2T when the waist gather G2 shrinks. While Figure 10 shows the cover sheet 4F portion, the same is true for the cover sheet 4R. In this modified diaper 1, the fold-back lines 4F6, 4R6 of the cover sheets 4F, 4R are dotted ventilation holes formed by small straight slits, so that when the waist gather 3R shrinks due to the contraction force of the elastic threads 4F1, 4F2, the small slits forming the fold-back lines 4F6, 4R6 widen, and the ventilation holes 4F6K in the portions other than the seams 4F6T between the slits widen. Therefore, in the diaper 1 of this modification, not only the ventilation passages (spaces shown in halftone in FIG. 10) formed between the ventilation passage forming sheets 11F, 11R and the cover sheets 4F, 4R, but also the ventilation passages (spaces shown in hatching in FIG. 10) formed in the cover sheets 4F, 4R by folding back the cover sheets 4F, 4R at the folding lines 4F6, 4R6 are formed. Therefore, the diaper 1 of this embodiment has high breathability in the waist gathers 3R compared to a diaper 1 in which the ventilation holes 4F6K are not formed at the folding lines 4F6, 4R6. In particular, when combined with the embodiment having the double pump function shown as the modification above, that is, the embodiment in which the pump function is exerted at two locations, the first contraction portion S1 of the waist gathers G2 and the tummy gathers G3, ventilation through the ventilation holes 4F6K is also provided, and moisture in the diaper 1 can be discharged more smoothly. This makes it possible to create a more comfortable environment in the interior space of the diaper 1.

In the above embodiment, the diaper 1 is provided with the air passage forming sheets 11F, 11R, but the air passage forming sheets 11F, 11R may be omitted. If the air passage forming sheets 11F, 11R are omitted, the first air passage 111 and the second air passage 112 are lost, but the degree of restraint by the third rubber threads 4F3, 4R3 is maintained, so that the size of the folds formed in the third contraction portion S3 is maintained to be larger than the surrounding area, and the pump effect in the third contraction portion S3 can be maintained as in the above embodiment.

1: Diaper 1B: Crotch region 1F: Front body region 1R: Back body region 2T: Torso opening G2: Waist gathers 4F, 4R: Cover sheet 4F1, 4R1: First elastic thread 4F2, 4R2: Second elastic thread 4F3, 4R3: Third elastic thread 4F4, 4R4: Fourth elastic thread 11F, 11R: Air passage forming sheet S: Joint portion S1: First contracted portion S2: Second contracted portion S3: Third contracted portion S4: Fourth contracted portion

Claims (5)

An absorbent article including a front body region covering an abdomen of a wearer, a rear body region covering a back of the wearer, and a crotch region located between the front body region and the rear body region and in which an absorbent body is disposed, the absorbent article comprising:
A waist opening lower contraction portion includes a plurality of elastic members extending from at least a portion corresponding to a hip bone of the wearer in a waist opening through which the wearer's waist can be inserted, and contracts the waist opening in the waist direction.
a torso opening upper contraction portion including a plurality of elastic members extending along a torso direction between an opening edge of the torso opening and the torso opening lower contraction portion, the torso opening upper contraction portion contracting the torso opening in the torso direction;
The intervals between the plurality of elastic members in the lower contractible portion of the torso opening are greater than the intervals between the plurality of elastic members in the upper contractible portion of the torso opening,
The garment further includes an air passage forming sheet that is laminated and arranged to cover the skin-facing surfaces of the upper contracted portion of the body opening and the lower contracted portion of the body opening,
The air-passage forming sheet is joined to the skin-facing surface by a plurality of joining parts provided at intermittent intervals of alternating large and small sizes along the waist circumference direction, and a non-jointed area located between the joining parts is deflected and deformed into a wave shape by contraction of the upper contracted part of the waist opening and the lower contracted part of the waist opening, thereby forming a first air passage surrounded by the upper contracted part of the waist opening and the lower contracted part of the waist opening and the non-jointed area of the air-passage forming sheet, and a second air passage, which is a gap formed between the air-passage forming sheet and the skin of the wearer, is formed on the skin-facing surface side of the air-passage forming sheet.
Absorbent articles. The interval between the multiple elastic members of the lower contraction portion of the body opening is 6.5 mm or more and 12 mm or less.
The absorbent article of claim 1. The lower contracted portion of the body opening is provided in a region including a range of 20 mm to 40 mm from the edge of the opening.
3. The absorbent article according to claim 1 or 2. The waist opening further includes an opening edge side contraction portion that includes a plurality of elastic members extending in a waist circumference direction along the opening edge between the opening edge and the waist opening upper contraction portion, and contracts the waist opening in the waist circumference direction,
The spacing between the plurality of elastic members in the opening edge side contracted portion is greater than the spacing between the plurality of elastic members in the body opening upper contracted portion.
An absorbent article according to any one of claims 1 to 3 . a cover sheet including an elastic member of the upper contractible portion of the body opening in a portion that forms the body opening;
the cover sheet is folded back at the edge of the opening, and a continuous air hole is formed at the fold of the folded back portion, passing through the cover sheet;
5. An absorbent article according to any one of claims 1 to 4 .

Images