JP7494530B2 - Absorbent articles - Google Patents

Description

The present invention relates to an absorbent article.

In absorbent articles that absorb liquids such as urine and body fluids, elastic members are arranged in areas that correspond to the wearer's waist and legs (for example, Patent Document 1). The elastic members arranged in areas that correspond to the legs are arranged so as to stretch in the longitudinal direction of the absorbent article, and prevent gaps from forming between the wearer's legs and the absorbent article. In addition, the elastic members are arranged between the back sheet and the side sheet, centered on the crotch area that corresponds to the wearer's crotch.

JP 2018-140066 A

In absorbent articles, an adhesive-coated elastic member is placed on the skin-facing side of the back sheet in a region that corresponds to the area around the legs, and then a side sheet is laminated on the skin-facing side of the back sheet. As a result, the back sheet and the side sheet are joined in the area where the elastic member is placed, but the back sheet and the side sheet are not joined on a virtual extension line that is virtually extended in the direction in which the elastic member stretches. When the absorbent article is worn, if a force is applied to the part where the back sheet and the side sheet are not joined, forming a gap, there is a risk that liquid will leak through the gap.

The present invention aims to provide an absorbent article that prevents liquid leakage.

In order to solve the above problem, the present invention provides a first elastic member that is bonded along the width direction of the rear body region while stretched in the width direction.

In detail, the present invention relates to an absorbent article having a front body region located on the abdomen side of a wearer when worn, a crotch region located under the crotch, and a rear body region located on the back side, arranged in this order in the longitudinal direction, the absorbent article comprising: an absorbent body arranged to include the crotch region; a top sheet arranged on the skin-facing side of the absorbent body; a back sheet arranged on the non-skin-facing side of the absorbent body and formed wider than the top sheet; a pair of side sheets arranged on both sides of the top sheet in the width direction of the absorbent article and on the skin-facing side of the back sheet; a first elastic member bonded in a state stretched in the width direction along the width direction of the rear body region; and a pair of second elastic members arranged between the back sheet and the side sheet, bonded to at least one of the back sheet or the side sheet in a state stretched in the longitudinal direction, the pair of second elastic members arranged in an area not overlapping with the first elastic member.
The back sheet and the side sheet are not joined on a virtual extension line that is virtually extended in the stretching direction of the second stretchable member.

In the above absorbent article, a waist gather is formed by the first elastic member,
The second elastic member may form leg gathers.

In the above absorbent article, the back sheet extends to the rear body region and is positioned so as to overlap at least a portion of the first elastic member, and in the region where the back sheet and the first elastic member overlap, the first elastic member may be adhered to the non-skin-facing side of the back sheet.

The absorbent article may include a film that is joined to an exterior surface in the front body region and to which a tape is attached for fixing the absorbent article to the wearer, and the tape that protrudes from the rear body region on both sides in the width direction and fixes the absorbent article around the waist of the wearer while being attached to the film.

In the above absorbent article, the first elastic member may be urethane foam, and the second elastic member may be rubber thread.

This invention makes it possible to prevent liquid leakage.

FIG. 1 is a perspective view of a diaper according to an embodiment. FIG. 2 is an exploded perspective view of the diaper according to the embodiment. FIG. 3 is a cross-sectional view of the diaper according to the embodiment in an unworn state, taken along the width direction at the center in the longitudinal direction. FIG. 4 is a plan view of the diaper according to the embodiment in a stretched state, as viewed from the skin-facing side.

Below, absorbent articles according to embodiments of the present invention will be described with reference to the drawings. Note that the configurations of the following embodiments are examples, and the present invention is not limited to the configurations of these embodiments.

<Embodiment>
In this embodiment, the longitudinal direction of a tape-type disposable diaper (an example of an "absorbent article" in the present application, hereinafter simply referred to as a "diaper") is the direction connecting the front body arranged opposite the wearer's abdomen and the rear body arranged opposite the wearer's back. Between the front body (one side in the longitudinal direction) and the rear body (the other side in the longitudinal direction) (the center in the longitudinal direction), a crotch part arranged under the wearer's crotch (opposed to the crotch). In addition, when the diaper is worn by a wearer (hereinafter abbreviated as "worn state"), the side facing the wearer's skin (the inner side when worn) is the skin-facing side, and the opposite side of the skin-facing side (the outer side when worn) is the non-skin-facing side. Furthermore, the direction connecting the skin-facing side and the non-skin-facing side is the thickness direction, and the direction perpendicular to both the longitudinal direction and the thickness direction is the width direction. In addition, the view from the thickness direction is the planar view.

FIG. 1 is a perspective view of a diaper according to the present embodiment. The diaper 1 has a crotch region 1B, which corresponds to the crotch of the wearer covering the pubic region when worn, a front body region 1F, which is located in front of the crotch region 1B and corresponds to the front body of the wearer, and a rear body region 1R, which is located behind the crotch region 1B and corresponds to the rear body of the wearer. Tapes 2L and 2R are provided on both left and right edges of the rear body region 1R, which can be attached to a front patch 2F provided on the non-wearer side surface of the front body region 1F. The tape 2L has a hook portion 20L arranged on a surface facing the front patch 2F when the diaper 1 is worn. Similarly, the tape 2R has a hook portion 20R arranged on a surface facing the front patch 2F when the diaper 1 is worn. The front patch 2F has a loop portion on its surface that can be engaged with the hook portions 20L and 20R. In addition, the tip portion 21L of the tape 2L in the width direction of the diaper 1 has a wavy shape. Similarly, a tip portion 21R of the tape 2R in the width direction of the diaper 1 has a wavy shape.

When the tapes 2L, 2R are attached to the front patch 2F with the front body region 1F positioned against the wearer's abdomen and the rear body region 1R positioned against the wearer's back, the diaper 1 is secured to the wearer's body surrounding the wearer's waist and thighs. Since the diaper 1 is secured to the wearer's body in this manner, the wearer can stand and walk around while wearing the diaper 1.

In the diaper 1, an absorbent 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 can serve as a liquid outflow path, the diaper 1 is provided with leg gathers 3AL, 3AR in the area surrounding the wearer's legs (thighs), three-dimensional gathers 3BL, 3BR are provided on the inside of the leg gathers 3AL, 3AR in the width direction of the diaper 1, and a waist gather 3R is provided in the area surrounding the wearer's abdominal circumference. The leg gathers 3AL, 3AR, three-dimensional gathers 3BL, 3BR, and waist gathers 3R are in close contact with the wearer's skin by the elasticity of rubber thread, urethane foam, etc. Therefore, liquid discharged from the wearer's genitals is absorbed by the absorbent of the diaper 1 without leaking out of the diaper 1.

2 is an exploded perspective view of the diaper 1. FIG. 3 is a cross-sectional view of the diaper 1 when not worn, cut along the width direction at the center in the longitudinal direction. FIG. 4 is a plan view of the diaper 1 when stretched, as viewed from the skin side. In FIG. 4, the dashed line C1 is a center line representing the width direction center of the diaper 1. The diaper 1 has a cover sheet 4 that forms the outer surface when worn. The cover sheet 4 is a sheet-like member having a substantially rectangular appearance with constrictions 4KL, 4KR at the portions corresponding to the long sides, and forms the exterior surface of the diaper 1. The constrictions 4KL, 4KR are provided at the portions where the wearer's thighs are located (the leg surrounding regions 10L, 10R shown in FIG. 4). The cover sheet 4 is provided to reinforce the back sheet 5 described later and to improve the feel, and for example, a nonwoven fabric made of a liquid-impermeable thermoplastic resin can be used as the material for the cover sheet 4 in order to suppress leakage of excrement. Examples of liquid-impermeable thermoplastic resins include polyethylene (PE) and polypropylene (PP). The cover sheet 4 is not limited to a single-layer structure, but may be a multi-layer structure having an inner cover sheet and an outer cover sheet.

The diaper 1 has a back sheet 5, an absorbent 6C, and a top sheet 7, which are laminated in order on the wearer's side of the cover sheet 4. The back sheet 5, the absorbent 6C, and the top sheet 7 are all sheet-like members having an approximately rectangular appearance, and are laminated in order on the cover sheet 4 with their longitudinal direction coinciding with the longitudinal direction of the cover sheet 4. The back sheet 5, like the cover sheet 4, is a sheet formed from a liquid-impermeable thermoplastic resin material to suppress leakage of excrement. The back sheet 5 is preferably made of a material that also has moisture permeability to suppress stuffiness when worn. The top sheet 7 is a sheet-like member that is placed on the skin side of the wearer so as to cover the water-absorbing surface of the absorbent 6C. This top sheet 7 is liquid permeable in part or in its entirety. Therefore, when the diaper 1 is worn, liquid excreted from the wearer passes through the top sheet 7, which may come into contact with the wearer's skin, and enters the absorbent 6C, where it is absorbed. For example, woven fabric, nonwoven fabric, and porous film can be used as materials for the top sheet 7. The top sheet 7 may be hydrophilic.

The back sheet 5, absorbent 6C, and top sheet 7 all extend from the front body region 1F to the rear body region 1R. Therefore, when the wearer's private parts are covered with the cover sheet 4 in which the back sheet 5, absorbent 6C, and top sheet 7 are laminated, both ends in the longitudinal direction of the back sheet 5, absorbent 6C, and top sheet 7 are located on the wearer's ventral side and back side. In other words, the wearer's private parts are covered by the absorbent 6C from the wearer's ventral side to the back side. Therefore, whether the wearer is in a ventral or back-down position when excreting liquid, the excreted liquid comes into contact with the absorbent 6C via the top sheet 7.

The diaper 1 also has long, narrow, strip-shaped side sheets 8L, 8R. The side sheets 8L, 8R are liquid-impermeable sheets provided on the long sides of the top sheet 7. Like the cover sheet 4, the side sheets 8L, 8R have constrictions 8KL, 8KR at the areas where the wearer's thighs are located (leg-surrounding regions 10L, 10R shown in FIG. 4). Rubber threads 8EL, 8ER are woven into the side sheets 8L, 8R along their longitudinal direction to form three-dimensional gathers 3BL, 3BR. When the diaper 1 is worn, i.e., when the diaper 1 is U-shaped in side view, the side sheets 8L, 8R are drawn in the longitudinal direction by the contraction force of the rubber threads 8EL, 8ER and rise from the top sheet 7, forming three-dimensional gathers 3BL, 3BR that prevent liquid from leaking out.

In addition, in the diaper 1, rubber threads 5SL, 5SR (corresponding to the "second elastic member") for forming the leg gathers 3AL, 3AR described above are provided between the back sheet 5 and the side sheets 8L, 8R so as to be elastic in the longitudinal direction of the diaper 1. The rubber threads 5SL, 5SR are provided in an appropriate number (three in this embodiment) determined according to the elastic force (contractile force) required in the design of the diaper 1. As shown in Fig. 4, the leg gathers 3AL, 3AR are arranged to include leg surrounding regions 10L, 10R, which are the regions in the diaper 1 where the thighs of the wearer are located. The leg surrounding regions 10L, 10R are arranged at both widthwise end portions of the crotch region 1B. The regions where the rubber threads 4SL, 4SR are arranged are the leg gathers 3AL, 3AR.

Between the cover sheet 4 and the back sheet 5, rubber threads 4C are provided along the longitudinal direction of the diaper 1, on the inner side of the rubber threads 5SL and 5SR in the width direction of the diaper 1, in order to prevent a gap from being formed between the diaper 1 and the wearer's abdominal circumference, when viewed in the thickness direction. An appropriate number of rubber threads 4C (three in this embodiment) is provided depending on the elastic force (contractile force) required for the design of the diaper 1.

The elastic member 9ER (corresponding to the "first elastic member") for forming the waist gather 3R described above is provided between the back sheet 5 and the cover sheet 4 at a position further back than the end of the absorbent body 6C. The elastic member 9ER is attached in a stretched state to the non-skin-facing side of the back sheet 5 with its longitudinal direction, which is the stretch direction, oriented in the left-right direction of the diaper 1 (width direction). When the tapes 2L, 2R provided on both the left and right sides of the elastic member 9ER are attached to the front patch 2F on the wearer's abdominal side, the elastic member 9ER exerts a contractile force to bring the diaper 1 into close contact with the wearer and prevent the formation of a gap between the diaper 1 and the wearer's abdominal circumference.

The absorbent 6C has a structure in which granular absorbent resin such as SAP (Super Absorbent Polymer), a hydrophilic polymer with a cross-linked structure that can absorb and retain water, is held in the gaps between short fibers of cellulosic fibers such as pulp fibers, rayon fibers, or cotton fibers, or short fibers that have been hydrophilically treated synthetic fibers such as polyethylene, polypropylene, or polyethylene terephthalate. Therefore, in the absorbent 6C, the volumetric change of the absorbent resin before and after absorbing liquid basically occurs within the short fibers that hold the absorbent resin in the gaps. Therefore, when looking at the absorbent 6C as a whole, it can be said that the expansion rate of the thickness of the absorbent 6C that has absorbed liquid is not as large as the expansion rate of the absorbent resin itself.

The SAP particles of the present embodiment refer to a resin composition containing SAP in a granular form. The term "SAP-containing resin composition" as used herein includes both a composition consisting of SAP alone and a composition containing SAP as the main component and containing other substances to the extent that they do not adversely affect water absorption. Examples of the "other substances" include additives (such as a surface modifier added to make the particle surface hydrophobic), unreacted monomers remaining during the synthesis of SAP, and the like.

Thus, the diaper 1 according to this embodiment includes an absorbent 6C arranged including the crotch region 1B, a top sheet 7 arranged on the skin-facing side of the absorbent 6C, a back sheet 5 arranged on the non-skin-facing side of the absorbent 6C and formed wider than the top sheet 7, a pair of side sheets 8L, 8R arranged on both sides of the top sheet 7 in the width direction of the diaper 1 and on the skin-facing side of the back sheet 5, an elastic member 9ER arranged along the width direction of the rear body region 1R and elastic in the width direction, and rubber threads 5SL, 5SR arranged between the back sheet 5 and the side sheets 8L, 8R and between the back sheet 5 and the side sheets 8L, 8R in a state stretched in the longitudinal direction of the diaper 1. The rubber threads 5SL, 5SR may be bonded to at least one of the back sheet 5 and the side sheets 8L, 8R.

As shown in FIG. 4, the rubber threads 5SL, 5SR are arranged in a range that does not overlap with the elastic member 9ER. Here, the back sheet 5 and the side sheets 8L, 8R are not joined on an extension line virtually extended in the direction of elasticity (extension direction) of the rubber threads 5SL, 5SR. This is because, in the manufacturing process of the diaper 1, the rubber threads 5SL, 5SR to which adhesive is applied are arranged on the leg areas 10L, 10R on the skin-facing side of the back sheet 5, and then the side sheets 8L, 8R are laminated on the skin-facing side of the back sheet 5 to join the back sheet 5 and the side sheets 8L, 8R. Therefore, the back sheet 5 and the side sheets 8L, 8R are joined in the arrangement area of the rubber threads 5SL, 5SR, but the back sheet 5 and the side sheets 8L, 8R are not joined in the area on the extension line where the rubber threads 5SL, 5SR are not arranged, i.e., in the area corresponding to the wearer's waist. In addition, in areas other than the extension lines of the rubber threads 5SL and 5S, the back sheet 5 and the side sheets 8L and 8R are joined with an adhesive.

The diaper 1 according to this embodiment includes an elastic member 9ER arranged along the width direction of the rear body region 1R. The elastic member 9ER is joined to the non-skin-facing side of the back sheet 5 in a stretched state, and stretches in the width direction. Therefore, when the tapes 2L, 2R are attached to the front patch 2F with the rear body region 1R pulled outward in the width direction, the areas where the back sheet 5 and the side sheets 8L, 8R are not joined are pulled outward in the width direction, preventing the formation of gaps in those areas. This allows the diaper 1 according to this embodiment to prevent liquids such as urine, SAP, etc. from leaking out from those areas to the outside of the diaper.

In the diaper 1 according to this embodiment, the elastic member 9ER is urethane foam. The back sheet 5 extends to the rear body region 1R and is arranged so as to overlap at least a part of the elastic member 9ER in the width direction of the diaper 1. In the area where the back sheet 5 and the elastic member 9ER overlap, the elastic member 9ER is bonded to the non-skin side of the back sheet 5. Since the elastic member 9ER is arranged on the non-skin side of the back sheet 5, the back sheet 5 and the side sheets 8L, 8R can be pressed against the skin side of the wearer by the elastic member 9ER, and the formation of gaps in the areas where the back sheet 5 and the side sheets 8L, 8R are not joined can be suppressed. Note that the elastic member 9ER is made of urethane foam instead of rubber thread, and the elastic member 9ER has a rectangular shape that is wider than the rubber thread and is thicker than the rubber thread. Therefore, the back sheet 5 and the side sheets 8L, 8R can be pressed against the skin side of the wearer more than when rubber thread is used for the elastic member 9ER.

The diaper 1 according to the present embodiment is a tape-type diaper. The diaper 1 includes a front patch 2F, which is joined to the exterior surface of the front body region 1F and to which tapes 2L, 2R are attached for fixing the diaper 1 to the wearer, and tapes 2L, 2R, which protrude from both sides in the width direction from the rear body region 1R and which are attached to the front patch 2F to fix the diaper 1 around the waist of the wearer. Here, there are areas in the front body region 1F where the back sheet 5 and the side sheets 8L, 8R are not joined, but the front patch 2F is joined to the front body region 1F so as not to bend in the width direction, thereby making the front body region 1F less likely to bend in the width direction. As a result, the diaper 1 according to the present embodiment makes the areas less likely to bend in the width direction, thereby suppressing the formation of gaps and preventing liquids such as urine and SAP from leaking from the areas.

In the above embodiment, a tape-type diaper is shown as an example, but the invention can also be applied to pants-type diapers and various other types of absorbent articles.

1... Diaper 1B... Crotch region 1F... Front body region 1R... Back body region 2F... Front patch 2FT... Ventilation hole 2L, 2R... Tape 2LA, 2RA... First surface 2LB, 2RB... Second surface 3BL, 3BR... Three-dimensional gathers 3R... Waist gathers 4... Cover sheet 4KL, 4KR... Constrictions 4C, 5SL, 5SR, 8EL, 8ER, 9ER... Elastic thread 5... Back sheet 6C... Absorbent body 7... Top sheet 8... Side sheet 10L, 10R... Leg surrounding regions 20L, 20R... Hook section

Claims (5)

An absorbent article having a front body region located on the abdomen side of a wearer in a worn state, a crotch region located between the crotch of the wearer, and a rear body region located on the back side, arranged in this order in a longitudinal direction,
An absorbent body disposed including the crotch region;
A top sheet disposed on the skin side of the absorbent body;
A back sheet is disposed on the non-skin facing side of the absorbent body and is formed wider than the top sheet;
A pair of side sheets arranged on both sides of the top sheet in the width direction of the absorbent article and on the skin-facing side of the back sheet;
A first elastic member bonded along the width direction of the rear body region in a state stretched in the width direction;
a pair of second elastic members disposed between the back sheet and the side sheet and bonded to at least one of the back sheet or the side sheet in a state stretched in the longitudinal direction, the second elastic members being disposed in an area not overlapping with the first elastic members;
Equipped with
The back sheet and the side sheet are not joined on a virtual extension line that is virtually extended in the stretching direction of the second stretchable member,
The back sheet extends to the rear body region and is positioned so as to overlap at least a portion of the first elastic member;
In the region where the back sheet and the first elastic member overlap, the first elastic member is adhered to the non-skin-facing side of the back sheet.
Absorbent articles. A waist gather is formed by the first elastic member,
A leg gather is formed by the second elastic member.
The absorbent article of claim 1. The first elastic member extends to both outer sides in the width direction of the absorbent article beyond the back sheet.
3. The absorbent article according to claim 1 or 2. a film joined to an exterior surface in the front body region and to which a tape is attached for fixing the absorbent article to the wearer;
the tape protruding from the rear body region on both sides in the width direction and attached to the film to fix the absorbent article around the waist of the wearer;
The absorbent article of claim 1 , comprising: The first elastic member is a urethane foam,
The second elastic member is a rubber thread.
5. The absorbent article according to any one of claims 1 to 4.

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