JP7390172B2 - Pants-type absorbent article - Google Patents

Description

The present invention relates to a pants-type absorbent article.

Conventionally, pants-type disposable diapers (hereinafter also referred to as "pants-type absorbent articles") have been used to absorb excrement from infants, adults, and sick people. The pants-type absorbent article forms a waist opening and a pair of leg openings, and has an absorbent body that absorbs excrement and an exterior body that is a support member for the absorbent body, and the absorbent body is attached to the wearer from the front and back. covers the groin area. Then, the wearer puts both feet into the leg openings, pulls the paper diaper body up to the waist, and puts it on.

The exterior body of a conventional pants-type absorbent article is divided into a waist opening, a torso area, and an inseam area, and an elastic member that stretches in the width direction is arranged at the waist opening and the torso area, and an elastic member that stretches in the width direction is placed in the inseam area near the leg area. Elastic stretchable members are arranged along the legs. Each elastic elastic member expands and contracts in only one direction. However, if a gap is created between the body and the pants-type absorbent article in the crotch region where the user urinates, urine tends to leak from the absorbent body. Therefore, the absorbent body is required to have a fit that allows it to fit properly against the body even after absorbing body fluids such as urine. In addition, comfort in the crotch area and ease of movement around the legs are also required.

Patent Document 1 discloses a pants-type absorbent article consisting of an exterior body and an absorbent main body, in which a waist opening and a pair of left and right leg openings are formed in the exterior body, in which the exterior body has a right edge of the side part. a first elastic member extending from the left side edge of the ventral side through the crotch area to the right edge of the dorsal side through the crotch area; a second elastic member that intersects with the elastic member; and a third elastic member that is located between the left and right leg openings and the absorbent body, and whose both ends overlap the first and second elastic members. A pant-type absorbent article is disclosed.

Patent Document 2 discloses a plurality of front waist elastic members provided in the front waist region along the width direction substantially orthogonal to the length direction from the front waist region to the rear waist region for expanding and contracting the front waist region. , a plurality of rear waistline stretchable materials are provided along the width direction of the rear waistline section for expanding and contracting the rear waistline section, and the total elongation stress of the plurality of front waistline stretchable materials and the plurality of The front waist elastics and the rear waist elastics are arranged so that the total elongation stress of the rear waist elastics is approximately equal and the number of front waist elastics is greater than the number of rear waist elastics. A pants-type absorbent article is disclosed. Further, Patent Document 2 discloses that the front waist elastic material and the rear waist elastic material are arranged so that the total elongation stress of the plurality of front waist elastic materials and the total elongation stress of the plurality of rear waist elastic materials are approximately equal. By arranging it, the back and ventral sides of the wearer can be tightened evenly, and even if the weight of the pants-type absorbent article increases after excretion, one of the front waist or back waist will not slip off. It is stated that this can be prevented.

Patent Document 3 describes an absorbent body including a liquid-permeable top sheet, a liquid-impermeable back sheet, and an absorbent body disposed between these, and an exterior sheet bonded to the outer surface side of the back sheet. A pants-type absorbent article comprising: a dorsal torso portion located on the back side of the wearer; a crotch portion having leg portions on both sides in the width direction; The ventral waist portion located on the ventral side is provided integrally in the longitudinal direction, and is formed by joining both widthwise sides of the dorsal waistline and both widthwise sides of the ventral waistline. A waist opening located around the wearer's waist, a pair of leg openings located around the wearer's legs, a waist elastic member disposed around the entire edge of the waist opening, and a waist opening located around the wearer's legs; It has a plurality of dorsal elastic members that can be expanded and contracted in the width direction, and a plurality of ventral side elastic members that can be expanded and contracted in the width direction. is formed with a ventral elastic region extending in the longitudinal direction, the number of dorsal elastic members is greater than that of the ventral elastic members, and the distance between the dorsal elastic member and the waist elastic member closest to it is the same as the ventral elastic region. A dorsal elastic member is disposed at a position approximately equal to the distance between the member and the waist elastic member closest to it, the dorsal elastic region is formed wider in the longitudinal direction than the ventral elastic region, and the absorbent main body is discloses a pants-type absorbent article disposed at a position that does not overlap with the ventral elastic region and overlaps with the dorsal elastic region. In the above, the longitudinal direction and the width direction are the longitudinal direction and the width direction of the pants-type absorbent article, respectively.

Japanese Patent Application Publication No. 09-313531 JP2012-217553A Patent No. 4352003

Patent Document 1 is an invention that attempts to solve the problem of pants-type absorbent articles slipping down when worn by simply arranging a predetermined elastic member. Therefore, even if the configuration of the present invention is used, it is difficult to improve the fit of the absorbent main body in the crotch region, and a sufficient effect cannot be obtained with respect to slippage. Furthermore, the tension in the elastic members around the waist and legs becomes excessive, which may cause stress and discomfort to the wearer.

Patent Document 2 has a structure similar to that of Patent Document 1, in which the elastic member is arranged around the crotch area of the pants-type absorbent article, especially around the legs, and intersects at the crotch area. It is not possible to improve the fit.
Patent Document 3 does not attempt to improve the fit of the absorbent main body in the crotch region or around the legs.

An object of the present invention is to provide a pants-type absorbent article that has excellent fit to the entire crotch region, excellent prevention of leakage of body fluids, and has a good feeling when worn.

As a result of intensive research in order to solve the above problems, the present inventor has developed a pants-type absorbent product that solves the above problems by using a predetermined material that is stretchable in all directions as the exterior body of the crotch area. It was discovered that an article could be obtained, and the present invention was completed. The present invention provides pants-type absorbent articles as described below (1) to (6) as preferred embodiments.

(1) A front region divided from the upper part into a front waist region and a front waist region, a rear region divided from the upper part into a rear waist region and a rear waist region, and an inseam region located between these. A pants-type absorbent article comprising: an exterior body comprising a liquid-permeable top sheet, a liquid-impermeable back sheet, and an absorbent body comprising an absorbent body disposed between these,
Both side edges of the front region and both side edges of the rear region are respectively joined to form a waist opening at the upper part of the front region and the rear region, and leg openings at both left and right sides of the crotch region. A side seal part that
a plurality of waist region elastic elastic members provided along the width direction in the front waist region and the rear waist region;
A plurality of elastic stretchable front waist regions are provided along the width direction in the front waist region and the rear waist region, respectively, and are arranged so as not to overlap with the absorbent main body in the thickness direction of the pants-type absorbent article. a member and a plurality of rear waist region elastic stretchable members;
an exterior body of the front region including a non-skin-side nonwoven fabric, a skin-side nonwoven fabric, and the waist region elastic stretchable member or the waist region elastic stretchable member disposed therebetween;
The non-skin side non-woven fabric, the skin-side non-woven fabric, and the waist region elastic elastic member or the waist region elastic elastic member disposed between them, and are provided separately from the exterior body of the front region. an exterior body in the rear area;
The crotch area exterior body is disposed in the entire area of the crotch area, includes a flexible polyurethane foam that is stretchable in all directions, and is joined to each exterior body of the front side region and the rear side area,
A pants-type absorbent article, wherein the leg opening periphery and the crotch region have regions where the elastic elastic member is not arranged.
In this specification, being able to expand and contract in all directions means being able to expand and contract in any of the following directions: one direction, a direction substantially perpendicular to one direction, and a direction inclined at 45 degrees with respect to one direction, and preferably It means that it can be expanded and contracted in any of the three directions in the range of 10 mm or more and 100 mm or less, and more preferably in the range of 20 mm or more and 80 mm or less in any of the three directions. .
(2) The pants-type absorbent article according to (1) above, wherein the basis weight of the flexible polyurethane foam forming the crotch region exterior body is 70 g/m ² or more and 300 g/m ² or less.
(3) The pants-type absorbent article according to (1) or (2) above, wherein the flexible polyurethane foam forming the crotch region exterior body has a thickness of 1.0 mm or more and 4.0 mm or less.
(4) The pants-type absorbent article according to any one of (1) to (3) above, wherein the MIU of the flexible polyurethane foam that is the outer covering for the crotch area is 0.3 or more and 1.0 or less.
(5) The pants-type absorbent article according to any one of (1) to (4) above, wherein the MMD of the flexible polyurethane foam that is the outer covering for the crotch area is 0.01 or more and 0.03 or less.
(6) The pants-type absorbent article according to any one of (1) to (5) above, wherein the elastic polyurethane foam serving as the crotch region exterior body has a stretching stress of 3.0 N or more and 4.5 N or less when stretched by 60 mm. .

According to the present invention, it is possible to provide a pants-type absorbent article that has excellent fit to the entire crotch region, excellent prevention of leakage of body fluids, and has a good feeling when worn.

1 is a perspective view schematically showing the external configuration of a pants-type absorbent article according to a first embodiment of the present invention. FIG. 2 is a developed plan view schematically showing the structure of the pants-type absorbent article shown in FIG. 1. FIG. It is a graph showing the results of a tensile test of an exterior body made of flexible polyurethane foam. It is a graph showing the results of a tensile cycle test of an exterior body made of flexible polyurethane foam and a commercially available exterior body.

Hereinafter, a pants-type absorbent article 1 according to an embodiment of the present invention will be described. In addition, when the pants-type absorbent article 1 is worn, the position on the wearer's ventral side is referred to as the "front" or "front side", and the position on the back side of the wearer is referred to as the "rear" or "rear side". to be called. The surface that faces the wearer's skin when the pants-type absorbent article 1 is worn is also referred to as the "inner side." Wearing the pants-type absorbent article 1 refers to a state in which the pants-type absorbent article 1 is worn on the body, regardless of whether before, during, or after absorbing bodily fluids. The pants-type absorbent article 1 is usually worn on the body inside clothing, but it may be worn on the body so that at least a portion thereof is exposed to the outside. The longitudinal direction of the pants-type absorbent article 1, the absorbent main body 20, and each component included therein refers to the direction extending from the front and back of the wearer's crotch area when the pants-type absorbent article 1 is worn on the body. It is. The width direction of the pants-type absorbent article 1, the absorbent main body 20, and each component included therein is a direction perpendicular to the longitudinal direction. The thickness direction of the pants-type absorbent article 1, the absorbent main body 20, and each component included therein is the direction in which each component is laminated. In addition, the skin side surface (skin-side surface) of the pants-type absorbent article 1, the absorbent main body 20, and each component included therein refers to the skin side surfaces (skin-side surfaces) that contact the wearer's skin when the pants-type absorbent article 1 is worn on the body. The non-skin side surface (non-skin side surface) is the surface that comes into contact with the wearer's clothing or the surface that faces the clothing when the pants-type absorbent article 1 is worn on the body. . In addition, body fluids refer to fluids discharged from the body, such as urine, blood, and water in loose stools.

<Pants-type absorbent article>
FIG. 1 is a schematic perspective view showing the external configuration of a pants-type absorbent article 1 according to the first embodiment, and FIG. 2 is a schematic developed plan view of the pants-type absorbent article 1 shown in FIG. 1. Note that each figure does not specify the size relationship of the constituent members such as the absorbent main body 20 and the exterior body 30 of the pants-type absorbent article 1, and the dimensions of each constituent member are the same as those of the pants-type absorbent article 1. They can be appropriately selected from a wide range depending on the intended use, the age of the wearer, etc.

The pants-type absorbent article 1 includes an absorbent body 20 having a substantially band-like shape in the front-rear direction that covers the crotch region of the wearer from the front and back, and an absorbent body 20 that extends around the absorbent body 20 while overlapping the outside of the absorbent body 20. An exterior body 30 that configures the external shape of the pants-type absorbent article 1 is provided. As shown in FIGS. 1 and 2, the exterior shape of the pants-type absorbent article 1 is configured by the exterior body 30. It is divided into a rear side area 15 that abuts, and an inseam area 14 that is arranged so that a part or all of the absorbent main body 20 overlaps.

It is preferable that the longitudinal dimension of the pants-type absorbent article 1 before disposing the elastic elastic member 1 when unfolded is 600 mm or more and 1000 mm or less, and the width direction dimension is 450 mm or more and 900 mm or less. By setting the unfolded dimensions of the pants-type absorbent article 1 before disposing the elastic elastic member within the above range, the pants-type absorbent article for adults of various sizes such as S size, M size, L size, etc. can be provided.
Hereinafter, the absorbent main body 20 and the exterior body 30 that constitute the pants-type absorbent article 1 of this embodiment will be described in detail.

<Absorbent body>
As shown in FIG. 2, the absorbent main body 20 includes a liquid-permeable top sheet 24, a liquid-impermeable back sheet 25, and an absorbent body 29 disposed between the top sheet 24 and the back sheet 25. include. In addition, similarly to the above, in order to be able to provide pants-type absorbent articles for adults of various sizes, the lengthwise dimension of the absorbent body 20 is 300 mm or more and 500 mm or less, and the widthwise dimension is It is preferably 100 mm or more and 300 mm or less.
Each component included in the absorbent main body 20 will be described in detail below.

(Top sheet)
The top sheet 24 may be formed from a base material having liquid permeability that allows bodily fluids to move to the absorbent body 29, such as a nonwoven fabric such as a thermal bond nonwoven fabric or a spunbond nonwoven fabric, or a thermal bond nonwoven fabric and a spunbond nonwoven fabric. It is made of hydrophilic non-woven fabric materials such as composite non-woven fabrics that are laminated with non-woven fabrics, and materials other than non-woven fabrics that are soft to the touch and do not irritate the skin. Further, the top sheet 24 may be embossed or perforated on the surface in order to improve liquid permeability. As a method for performing embossing or perforation, any known method can be used without limitation. Further, in order to reduce irritation to the skin, the top sheet 24 may contain a lotion, an antioxidant, an anti-inflammatory component, a pH adjuster, an antibacterial agent, a humectant, and the like. Furthermore, from the viewpoint of strength and workability, the basis weight of the top sheet 24 is preferably 18 g/m ² or more and 40 g/m ² or less. The shape of the top sheet 24 is not particularly limited, but may be any shape that covers the absorbent body 29 and is required to guide body fluids to the absorbent body 29 to prevent leakage.

(back seat)
The backsheet 25 may be formed using a liquid-impermeable base material that prevents body fluids held by the absorbent body 29 from wetting clothing, and may be formed from a breathable or non-breathable resin film. Ru. Examples of resin films that can be used include polyester, polyvinyl alcohol, polyethylene, polypropylene, and composite films of polyethylene and polypropylene. In terms of strength and workability, the basis weight of the backsheet 25 is preferably 15 g/m ² or more and 40 g/m ² or less. Further, in order to prevent stuffiness when worn, it is preferable to use a breathable resin film as the back sheet 25. In order to provide the backsheet 25 with air permeability, for example, a filler may be added to the resin film of the base material, or the backsheet 25 may be embossed. In addition, calcium carbonate can be mentioned as a filler, and its compounding method can be carried out by any known method without restriction. For example, a porous resin film with good air permeability can be obtained by blending a filler with a resin, forming a film (or sheet), and removing the filler.

(Absorber)
The absorbent main body 20 has an absorbent body 29 disposed between a top sheet 24 and a back sheet 25. The absorbent body 29 contains absorbent fibers as a base material and super absorbent polymer (SAP). Absorbent fibers are not particularly limited as long as they are generally used in absorbent articles such as sanitary napkins, diapers, and incontinence pads; examples include fluff pulp, cotton, rayon, acetate, tissue, absorbent paper, and hydrophilic fibers. For example, nonwoven fabrics and the like can be mentioned. Among these, it is preferable to use fluff pulp from the viewpoint of absorbency. Examples of such fluff pulp include those obtained by defibrating wood pulp, synthetic fibers, polymer fibers, non-wood pulp, etc. into fluff. The absorbent fibers of the absorbent body 29 preferably have a basis weight of 50 g/m ² or more and 800 g/m ^{2 or} less so as not to impair absorption performance and texture.

The superabsorbent polymer used for the absorbent body 29 is not particularly limited as long as it can absorb body fluids and prevent backflow; polyacrylate-based, polyaspartate-based, (starch-acrylic) Those formed from materials such as (acrylic acid) graft copolymers, (acrylic acid-vinyl alcohol) copolymers, (isobutylene-maleic anhydride) copolymers, and saponified products thereof can be used. Among these, from the viewpoint of absorption per weight, polyacrylate-based materials are preferred, and sodium polyacrylate-based materials are more preferred. The amount of SAP in the absorbent body 29 is preferably set to a basis weight of 10 g/m ² or more and 500 g/m ² or less, and the content is 15% by mass or more and 50% by mass or less, so as not to impair absorption performance and texture. is preferred.

The form of the absorbent fibers and SAP in the absorbent body 29 is preferably in the form of a laminated mat formed by mixing SAP particles in the absorbent fibers. It is also possible to use SAP formed into fiber form. Furthermore, for the purpose of preventing leakage of SAP particles and stabilizing the shape of the absorber 29, it is preferable to wrap the absorber 29 in a carrier sheet. The base material of the carrier sheet may be any material as long as it has hydrophilic properties, and examples thereof include tissue, absorbent paper, and hydrophilic nonwoven fabrics such as air-laid nonwoven fabrics. When a plurality of carrier sheets are provided, the base materials of the carrier sheets may be the same or different.

The absorbent body 29 may be composed of two or more absorbent layers, for example, it may be formed by laminating an upper layer absorber and a lower layer absorber. In this case, the longitudinal and widthwise dimensions of the upper absorbent core and the lower absorbent core may be such that the upper absorbent core may be larger than the lower absorbent core, and the upper absorbent core may have the same dimensions as the lower absorbent core. The dimensions of the upper absorbent core may be smaller than those of the lower absorbent core.

<Exterior body>
The exterior body 30 is a member that configures the external shape of the pants-type absorbent article 1, is laminated on the back sheet 25 side of the absorbent main body 20, and a part thereof is a laminate of a nonwoven fabric and an elastic stretchable member. As shown in FIG. 2, the exterior body 30 includes a front region 13 divided from the upper part (one end in the longitudinal direction) of the pants-type absorbent article 1 into a front waist region 13A and a front waist region 13B; It includes a rear region 15 divided into a region 15A and a rear waist region 15B, and a crotch region 14 located between the front region 13 and the rear region 15. Further, in the front region 13, the crotch region 14, and the rear region 15, the region where the side seal portion 303 (described later) is provided (that is, the region where the leg opening 12 is not formed) is defined as the front region 13 or the rear region 15, and the side seal The region where the portion 303 is not provided (that is, the region where the leg opening 12 is formed) can also be separated from the crotch region 14.

Each of the exterior bodies of the front region 13 and the rear region 15 includes an exterior nonwoven fabric sheet 301 on the non-skin side, an interior nonwoven fabric sheet 302 on the skin side, and an elastic elastic member (not shown) disposed between these. include. The exterior body of the crotch area 14 is disposed over the entire area of the crotch area 14 and is a sheet containing flexible polyurethane foam. The exterior body of the crotch region 14 has one longitudinal end joined to the exterior body of the front region 13 , the other longitudinal end joined to the rear region 15 , and the exterior body of the front region 13 and the exterior body of the rear region 15 . It is provided separately from the exterior body.

The exterior nonwoven fabric sheet 301 used for the exterior of the front region 13 and the rear region 15 has a front region 13 and a rear region 15 that are substantially symmetrical in the longitudinal direction about a center line extending in the width direction of the crotch region 14. However, the absorbent main body 20 is also arranged substantially symmetrically in the longitudinal direction about the center line. The exterior nonwoven fabric sheet 301 is folded in half along the center line so that the absorbent main body 20 is on the inside. The side seal portion 303 joins both widthwise edges of the front region 13 and both widthwise edges of the rear region 15, and includes a waist opening 11 having elasticity and a pair of leg openings 12. The pants-type absorbent article 1 is configured as a removable pants-like structure as a whole. In this embodiment, no elastic contraction member is arranged around the periphery of the pair of leg openings 12 and the crotch region 14 thus formed. Note that the peripheral edge of the leg opening 12 can also be referred to as the edge of the leg opening 12 and its vicinity.

An interior nonwoven fabric sheet 302 is laminated on the inside of the exterior nonwoven fabric sheet 301 via an elastic elastic member to increase the strength of the exterior body 30, for example. Further, the exterior body 30 may include an auxiliary sheet (not shown) that covers the periphery of the absorbent body 20 in addition to the exterior nonwoven fabric sheet 301, the elastic elastic member, and the interior nonwoven fabric sheet 302. An auxiliary sheet may be laminated to the interior nonwoven fabric sheet 302. The exterior nonwoven fabric sheet 301 and the interior nonwoven fabric sheet 302 are nonwoven fabrics such as thermal bond nonwoven fabrics, air-through nonwoven fabrics, and spunbond nonwoven fabrics, preferably air-through nonwoven fabrics or spunbond nonwoven fabrics, and are made of thermoplastic resins such as polypropylene, polyester, and polyethylene. A nonwoven fabric made of can be used. The basis weight of these nonwoven fabrics is, for example, 15 m ² or more and 40 g/m ² or less.

In this embodiment, a sheet containing flexible polyurethane foam having predetermined characteristics is used as the exterior body of the crotch region 14, preferably a sheet made of flexible polyurethane foam having predetermined characteristics. Sheets containing flexible polyurethane foam include those made by dispersing particles, fibers, etc. of flexible polyurethane foam in other synthetic resins and forming them into sheets, and fabrics made of fibers (non-woven fabrics, knitted fabrics, woven fabrics, etc.). Examples include those in which particles and fibers of flexible polyurethane foam are mixed. Hereinafter, these may be collectively referred to as a "flexible polyurethane foam sheet." Note that in this embodiment, no elastic elastic member is arranged in the crotch region 14.

The flexible polyurethane foam sheet of this embodiment can be expanded and contracted in all directions, and can be expanded and contracted not only in one direction but also in a direction substantially perpendicular to one direction and in a direction inclined at 45 degrees with respect to one direction. This is obvious from the results of the tensile test shown in FIG. 3, for example. According to FIG. 3, the flexible polyurethane foam sheet of this embodiment can be used in one direction (vertical), in a direction substantially perpendicular to one direction (horizontal), and in a direction tilted at a predetermined angle with respect to one direction ( 45°), preferably in a range of 10 mm or more and 100 mm or less, more preferably 20 mm or more and 80 mm or less. The ability to expand and contract in at least three or more different directions in this way is referred to as being able to expand and contract in all directions. The details of the tensile test will be described later. Such flexible polyurethane foam is described in, for example, Japanese Patent Application Publication No. 2019-127537.

As the flexible polyurethane foam of this embodiment, it is possible to use a flexible polyurethane foam that has the property of being able to expand and contract in all directions when molded into a sheet shape, for example as shown in FIGS. 3 and 4. However, the flexible polyurethane foam of this embodiment Foams have various properties other than stretchability. For example, the flexible polyurethane foam of this embodiment is preferably an open-celled foam. When closed cell foam is used instead of open cell foam, the fit to the wearer's crotch area tends to deteriorate. Note that open-celled foam can be easily confirmed by cutting the flexible polyurethane foam and observing the cut surface under a microscope. Further, the apparent density is preferably 0.01 g/cm ³ or more and 0.3 g/cm ³ . The expansion ratio is preferably 10 times or more and 60 times or less. By setting the apparent density and/or expansion ratio within the above range, the material can easily be expanded and contracted in all directions. When the foaming ratio is less than 10 times and/or the apparent density exceeds 0.3 g/cm ³ , elasticity becomes insufficient and the entire crotch area 14 tends to be difficult to fit around the wearer's crotch area. When the expansion ratio exceeds 60 times and/or the apparent density is less than 0.01 g/cm ³ , the strength of the flexible polyurethane foam decreases, and the absorbent body 20 tends to easily slip off after absorbing body fluids. There is. Further, the skeleton surface of the flexible polyurethane foam can be adjusted to be either hydrophobic or hydrophilic by, for example, appropriately selecting the raw material compound, but in this embodiment, hydrophobicity is preferred.

The flexible polyurethane foam of this embodiment is produced by mixing raw materials such as polyols and polyisocyanates, additives such as blowing agents, foam stabilizers, and catalysts, and heating the resulting mixture according to known manufacturing methods. It can be obtained by foaming. Alternatively, a gaseous blowing agent may be injected while reacting the raw material compounds under heating. By appropriately selecting reaction conditions such as the type of raw material compound, the type and amount of additives, heating temperature during foaming, foaming time, and pressure during foaming, the expansion ratio, apparent density, tensile strength, Properties such as tensile elongation at break, elongation stress, MIU, and MMD can be adjusted.

The flexible polyurethane foam sheet preferably has a basis weight of 70 g/m ² or more and 300 g/m ² or less, more preferably 100 g/m ² or more and 250 g/m ² or less. When the basis weight is less than 70 g/m ² , body fluids tend to leak easily, and when it exceeds 300 g/m ² , air permeability decreases and stuffiness tends to occur. Further, the thickness of the flexible polyurethane foam sheet is preferably 1.0 mm or more and 4.0 mm or less, and more preferably 1.5 mm or more and 3.2 mm or less. If it is less than 1.0 mm, the sheet tends to break easily, and if it exceeds 4.0 mm, the sheet tends to be bulky and hard, reducing the feeling of wearing the pants-type absorbent article 1. There is a risk. The thickness is measured using a height gauge (manufactured by Mitutoyo Co., Ltd.) under no-load conditions.

The flexible polyurethane foam sheet of this embodiment preferably has at least one of tensile strength, tensile elongation at break, elongation stress, MIU, and MMD within the range shown below.

(Tensile strength)
It is preferably 10.0N or more and 15.0N or less. If it is less than 10.0 N, the tightness when the pants-type absorbent article 1 is worn becomes weak, and there is a tendency for it to slip off. If it exceeds 15.0N, it tends to be difficult to stretch when worn, making it difficult to wear. Tensile strength and tensile elongation at break (described below) are based on JIS P8113 and JIS P8111 (temperature and humidity conditions), and the length after being maintained in an equilibrium state under temperature and humidity conditions of 23 ± 1°C and 50 ± 2% RH. A sample of 70 mm in length and 25 mm in width was stretched by 250% at a crosshead movement speed of 300 mm/min with the unstretched Tensilon tensile tester set at a distance of 50 mm between the chucks, and the value obtained when the sample was 250% stretched. .
(Tensile elongation at break)
The length is preferably 200 mm or more and 300 mm or less. If the tensile elongation at break is less than 200 mm, it tends to tear easily when worn, and if it exceeds 300 mm, it tends to be difficult to wear and the breathability decreases, making it easy to get stuffy.

(Extension stress when extended by 60mm)
It is preferably 3.0N or more and 4.5N or less, and more preferably 3.5N or more and 4.2N or less. When the elongation stress is less than 3.0 N, the tightness when the pants-type absorbent article 1 is worn becomes weak, and there is a tendency for the article to slip off. If the elongation stress exceeds 4.5N, it tends to be difficult to stretch when worn, making it difficult to wear. This elongation stress was measured in the same manner as the above-mentioned methods for measuring tensile strength and tensile elongation at break, except that the elongation length was changed from 250% to 220%. Then, after elongating by 60 mm (220%), an SS curve for one cycle (the horizontal axis is elongation mm and the vertical axis is load N) is created until returning to the original state. After the sample in the non-stretched state is stretched by 60 mm, the value on the SS curve at the time when the distance between the chucks is returned to 50 mm, which is the dimension in the non-stretched state, is defined as the stretching stress. FIG. 4 shows the SS curve of one cycle of the flexible polyurethane foam sheet of this embodiment, and for comparison, the waist region of a pants-type absorbent article made of a laminate of a nonwoven fabric, a thread-like elastic elastic member, and a nonwoven fabric. A 70 mm x 25 mm sample (long in the stretching direction of the thread-like elastic stretch member) was cut out from the exterior body and used to show the SS curve of one cycle. According to FIG. 4, it is clear that the flexible polyurethane foam sheet of this embodiment has higher elasticity than the laminate of a nonwoven fabric, a thread-like elastic elastic member, and a nonwoven fabric.

(MIU)
It is preferably 0.3 or more and 1.0 or less, more preferably 0.4 or more and 0.6 or less. If the MIU is less than 0.3, it becomes slippery when worn and tends to fall off. When MIU exceeds 1.0, it tends to be difficult to slip and become uncomfortable to wear. The higher the average coefficient of friction MIU, the more difficult it is to slip. The friction coefficient MIU and the average deviation MMD of the average friction coefficient are measured using a friction feel tester KES-SE (manufactured by Kato Tech Co., Ltd.), placing the sample on a smooth metal plane, and measuring the width of 0.5 cm and the length of the sample on the sample. Measurements are taken while moving the contact horizontally over a 2 cm area at a constant speed of 0.1 cm/sec. For the contact, ten 0.5 mm piano wires are used, and the load applied to the contact is 50 gf.
(MMD)
It is preferably 0.01 or more and 0.03 or less. If MMD is less than 0.01, it tends to be too smooth and easily slip off, and if it exceeds 0.03, the surface tends to be rough and the feeling of wearing becomes poor. The higher the average deviation MMD of the average coefficient of friction, the lower the smoothness and the greater the roughness.

Table 1 shows the MIU and MMD of an example of the soft polyurethane sheet of this embodiment and the exterior body (laminate of a nonwoven fabric, a filamentous elastic member, and a nonwoven fabric) used in the test shown in FIG. From Table 1, it can be seen that the flexible polyurethane sheet of this embodiment is a material that is hard to slip, has relatively little roughness, and has no practical problems.

(Front waist circumference area and rear waist circumference area)
In this embodiment, as described above, the front region 13 is divided from the top into the front waist region 13A and the front waist region 13B, and the rear region 15 is divided from the top into the rear waist region 15A and the rear waist region 15B. It is classified. The front waistline region 13B and the rear waistline region 15B are regions that come into contact with the vicinity of the ilium when the pants-type absorbent article 1 of this embodiment is worn. The front waist region 13A and the rear waist region 15A are regions above the front waist region 13B and the rear waist region 15B, respectively.

The front waist region 13A and the rear waist region 15A are regions in which a plurality of waist region elastic elastic members 311 are respectively arranged along the width direction. More specifically, the front waist region 13A and the rear waist region 15A are defined, for example, from the side forming the waist opening 11 (that is, the sides located at both ends in the longitudinal direction in FIG. 2) to the inseam region 14. This is an area of about 20 to 60 mm in the direction. The front waist region 13B refers to the region within the front region 13 excluding the front waist region 13A, and the rear waist region 15B refers to the region within the rear region 15 excluding the rear waist region 15A. Although the number of waist region elastic stretchable members 311 is not particularly limited, it is preferably 4 or more and 12 or less in both the side waist region 13A and the rear waist region 15A.

Although a plurality of waist region elastic stretchable members 311 are provided along the width direction in the front waist region 13A and the rear waist region 15A, no elastic stretchable members are provided in the crotch region 14 and the periphery of the pair of leg openings 12. Not yet. Further, in this embodiment, as the exterior body of the front region 13 and the rear region 15, a laminate in which an elastic elastic member is arranged between two nonwoven fabrics is used as in the conventional case. Unlike the conventional case, a flexible polyurethane foam sheet is used as the exterior body, and one longitudinal end and the other end of the flexible polyurethane foam sheet are joined to the exterior bodies of the front region 13 and the rear region 15, respectively. By adopting such a configuration, in this embodiment, even though no elastic elastic member is disposed around the crotch area 14 and the pair of leg openings 12, the flexible polyurethane foam sheet can freely stretch and contract. The crotch area 14 is moderately tightened, and the absorbent main body 20 perfectly fits the wearer's crotch area regardless of whether or not the body fluid is absorbed. As a result, no gap is created between the wearer's crotch area and the pants-type absorbent article 1, making it extremely difficult for bodily fluids to leak. In addition, the pants-type absorbent article 1 of the present embodiment has a flexible polyurethane foam sheet that is the exterior body of the crotch region 14, which is highly elastic and flexible, so that it not only fits the wearer's crotch area but also has good wearability. It also has an excellent feel. Furthermore, since no elastic stretchable members are provided around the crotch area 14 and the pair of leg openings 12, the wearer's crotch area is not tightened, and the range of motion around the legs is expanded, allowing the wearer to freely move around the legs. You can move your legs, which significantly improves the feeling of wearing it.

Further, in the front waist region 13B, a plurality of front waist region elastic elastic members 312 are arranged along the width direction at positions that do not overlap with the absorbent main body 20 in the thickness direction of the pants-type absorbent article 1. Further, in the rear waist region 15B, a plurality of rear waist region elastic stretchable members 313 are arranged along the width direction at positions that do not overlap with the absorbent main body 20 in the thickness direction of the pants-type absorbent article 1. There is. This gives the pants-type absorbent article 1 a good fit around the waist of the wearer (a position corresponding to the iliac region of the wearer). Note that if the absorbent main body 20 and the front waistline elastic stretchable member 312 or the back waistline elastic stretchable member 313 overlap in the thickness direction of the pants-type absorbent article 1, the absorbent main body 20 will contract in that region. Because it deforms, its absorbency decreases and leaks are more likely to occur. In this embodiment, by mainly devising the aspects of the front waist region 13B and the rear waist region 15B, the feeling of pressure in the lower abdomen of the pants-type absorbent article 1 is alleviated, and from the rear side (dorsal side) It is possible to improve the ability to prevent the material from slipping off.

In this embodiment, the front waist area when the pants-type absorbent article 1 is attached to the outside of a cylinder with a circumference of 800 mm so that the bottom surface of the cylinder coincides with a position at a depth of 150 mm from the waist opening 11. The size of the circular arc between the side seal parts 303 of the rear waist region 15B may be adjusted to be 40 mm or more larger than the size of the circular arc between the side seal parts 303 of the rear waist region 15B. Thereby, the feeling of pressure in the lower abdomen can be sufficiently suppressed when worn, and especially when worn by an elderly person with a protruding lower abdomen, the feeling of pressure in the lower abdomen can be effectively reduced. In addition, when tested under the above conditions, the dimension of the circular arc between the side seal parts 303 of the front waistline region 13B is 40 mm or more and 150 mm or less than the dimension of the circular arc between the side seal parts 303 of the rear waistline region 15B. It is preferable that there be. If the value exceeds 150 mm, it will tend to slip off from the front when worn. Furthermore, it is more preferable that the above numerical value range is 55 mm or more and 100 mm or less.

In this embodiment, the following relationship may be given to the front waistline region 13B and the rear waistline region 15B. After stretching the rear waistline region 15B in the width direction to 2.0 times the widthwise dimension of the rear waistline region 15B before stretching, the rear waistline region 15B is stretched to 1.0 times the widthwise dimension of the rear waistline region 15B before stretching. Stress X is the elongation stress in the width direction of the rear waistline region 15B at the time when it is returned to 5 times. After stretching the front waist region 13B in the width direction to 2.0 times the width direction dimension of the front waist region 13B before stretching, the front waist region 13B is stretched to 1.5 times the width direction dimension of the front waist region 13B before stretching. Let stress Y be the elongation stress in the width direction of the front waist region 13B at the time of return. At this time, the stress X is preferably 1.3 times or more, more preferably 1.3 times or more and 2.5 times or less, and still more preferably 1.5 times or more and 2.0 times or less as compared to the stress Y.

Further, when the pants-type absorbent article 1 is attached to the outside of a cylinder with a circumference of 800 mm so that the bottom surface of the cylinder coincides with a position at a depth of 150 mm from the waist opening 11, the rear waistline region 15B is The wearing pressure is preferably 1.2 times or more, more preferably 1.2 times or more and 2.0 times or less, and even more preferably 1.3 times or more and 1.7 times or less as compared to the wearing pressure of the front waist region 13B. . By setting this range, when an elderly person with a protruding lower abdomen leans forward, the difference in pressure between the front and back of the wearer's waist (corresponding to the wearer's iliac region) is reduced. Since it is small, it can suppress the feeling of pressure in the lower abdomen and prevent it from slipping off from the rear side (dorsal side) when leaning forward.

To measure the above-mentioned wearing pressure, an air pack type contact pressure measuring device manufactured by AMI Techno Co., Ltd. is used. An air pack is pasted at the measurement position of the circumference of 800 mm, and the pants-type absorbent article 1 is attached to the outside of the cylinder so that the bottom of the cylinder coincides with the position 150 mm deep from the waist opening 11. Then, the pressure difference between the air packs before and after installation is read and taken as the wearing pressure, and the wearing pressure on the widthwise center line of each of the rear waistline region 15B and the front waistline region 13B is read and adopted as the wearing pressure of each region.

The number of the rear waistline region elastic elastic members 313 is preferably 1.5 times or more, more preferably 1.5 times or more and 3.0 times or less, and even more preferably It is 1.7 times or more and 2.5 times or less. By adjusting in this way, it is possible to suppress the feeling of pressure in the lower abdomen and more effectively suppress slipping down from the rear side (dorsal side) when leaning forward. It is preferable that the number of the rear waist region elastic expansion/contraction members 313 is 8 or more and 20 or less.

The elongation rate of the rear waistline region 13B is preferably 1.3 times or more, more preferably 1.3 times or more and 2.0 times or less, and even more preferably 1.3 times the elongation rate of the front waistline region 15B. It is 1.5 times or less. By adjusting in this way, it is possible to suppress the feeling of pressure in the lower abdomen and more effectively suppress slipping down from the rear side when leaning forward. The elongation rate (%) indicates the length (%) at the time of maximum elongation with respect to the length of each of the rear waist region or the front waist region in a stationary state. In addition, if the value becomes too large, in the manufacturing process of the pants-type absorbent article 1, when joining both side edges of the front region 13 and both side edges of the back region 15 through the side seal portions 303, The decrease in efficiency is suppressed.

One rear waist circumference when one rear waist region elastic elastic member 313 is stretched to 3.0 times its dimension before stretching and returned to 2.0 times its dimension before stretching. Let stress A be the expansion/contraction stress of the region elastic expansion/contraction member 313. One front waist region elasticity when one front waist region elastic elastic member 312 is stretched to 3.0 times its dimension before stretching and returned to 2.0 times its dimension before stretching. Let stress B be the expansion/contraction stress of the expansion/contraction member 312. It is preferable that stress A is 1.2 times or more greater than stress B. By adjusting in this way, it is possible to suppress the feeling of pressure in the lower abdomen and more effectively suppress slipping down from the rear side when leaning forward. By using the elastic stretchable members 312 and 313 having such properties, it becomes easier to adjust the relationship between the stretch stress and the wearing pressure between the front waistline region 13B and the rear waistline region 15B.

Both ends of one rear waistline elastic stretchable member 313 are attached to the chucks of the Tensilon tensile testing machine, and the measurement sample with both ends of the rear waistline elastic stretchable member 313 sandwiched between the chucks is passed through the crosshead. Start stretching at a moving speed of 300 mm/min, stretch to 3.0 times the dimension of the rear girth region before stretching, and then create an SS curve until it returns to its original state. After stretching to 3.0 times the dimension of the front rear waist region elastic elastic member 313, read the numerical value on the SS curve at the time when it returns to 2.0 times the dimension before stretching, and use it as the stretching stress. . One front waist region elastic elastic member 312 is also measured in the same manner.

The above-mentioned elastic stretchable members 311, 312, and 313 are joined to the exterior nonwoven fabric sheet 301 and the interior nonwoven fabric sheet 302. Note that it is preferable that the interior nonwoven fabric sheet 302 and each of the elastic stretchable members 311, 312, and 313 are bonded to each other via a hot melt adhesive that is present only on each elastic stretchable member.
As the elastic stretchable member, for example, thread-like, string-like, or flat-shaped members made of natural rubber, synthetic rubber, polyurethane, etc. can be used as appropriate, and the thickness thereof is preferably 300 dtex or more and 1500 dtex or less.

[Method for manufacturing pants-type absorbent article]
There are no particular restrictions on the method of manufacturing the pants-type absorbent article 1, and conventionally known methods can be adopted.For example, the absorbent body 29 is sandwiched between the top sheet 24 and the back sheet 25, and the top sheet 24 and back sheet 25 to produce the absorbent main body 20, and in the front waist region 13A, front waist region 13B, rear waist region 15A, and rear waist region 15B, the outer nonwoven fabric sheet 301 and the interior nonwoven fabric sheet 302, a step of arranging each of the above-described elastic elastic members 311, 312, and 313 and joining them to the exterior nonwoven fabric sheet 301 and the interior nonwoven fabric sheet 302 to form each exterior body of the front region 13 and the rear region 15, respectively; A step of longitudinally joining the exterior bodies of the front region 13 and the rear region 15 via the exterior body (soft polyurethane foam sheet) of the crotch region 14, and disposing the absorbent main body 20 on the body side of the exterior body 30. The pants of this embodiment can be manufactured by a manufacturing method in which the steps of joining both side edges of the front region 13 and both side edges of the rear region 15 through the side seal portions 303 are carried out in this order. A shaped absorbent article 1 can be obtained.

Although the present invention has been described above using the embodiments, it goes without saying that the technical scope of the present invention is not limited to the scope of the invention described in the above embodiments. It will be obvious to those skilled in the art that modifications may be made. Furthermore, it is clear from the claims that forms with such changes or improvements may also be included within the technical scope of the present invention.

Hereinafter, the present invention will be described in detail by giving examples. Note that the present invention is not limited to the examples shown below.

First, an absorbent body is prepared by mixing fluff pulp and SAP, and the absorbent body is sandwiched between a top sheet (thermal bond nonwoven fabric) and a back sheet (breathable polyethylene film). A hot melt adhesive was used to fix the entire circumference to produce an absorbent main body.

In the front waist region and the rear waist region, six strings of synthetic rubber (elastic elastic member, thickness 1240 detx) are inserted along the width direction between the exterior nonwoven fabric sheet and the interior nonwoven fabric sheet, which are spunbond nonwoven fabrics, respectively. In addition, thread-like synthetic rubber (elastic elastic member, thickness 620 detx) is arranged between the exterior nonwoven fabric sheet and the interior nonwoven fabric sheet, which are spunbond nonwoven fabrics, in the front and rear waistband regions, respectively. 14 pieces (7 mm intervals) were arranged along the width direction, and the exterior nonwoven fabric sheet and the interior nonwoven fabric sheet were joined to form the exterior bodies of the front region and the rear region. Next, the exterior bodies of the front region and the back region were joined in the longitudinal direction via a flexible polyurethane foam sheet of a predetermined size as the exterior body of the crotch region, thereby producing the exterior body of the pants-type absorbent article. After that, the absorbent main body is arranged on the body side of the exterior body, and the both side edges of the front region and the rear region are connected via the side seal part, and the pants-type absorbent body is prepared before each elastic elastic member is arranged. A pants-type absorbent article was produced by adjusting the lengthwise dimension of the sex article when unfolded to be 780 mm and the widthwise dimension to be 560 mm (corresponding to size M for adults).

In this example, the apparent density is 0.06 g/cm ³ , the thickness is 2.26 mm, the basis weight is 138.8 g/m ² , the tensile strength is 12.5 N, the tensile elongation at break is 245.4 mm, and the elongation stress when stretched by 60 mm is 4. .1N, MIU of 0.524, and MMD of 0.021, and a sheet made of expanded polyurethane foam was used, which exhibited the expansion and contraction behavior shown in FIGS. 3 and 4. Further, when the sheet was cut and the cut surface was observed under a microscope, it was confirmed that the sheet was an open-celled material.

The obtained pants-type absorbent article uses a polyurethane foam sheet with high elasticity as the exterior body, especially in the crotch area, so that it fits well (closely adheres) to the wearer's entire crotch area, and has a good contact with the crotch area. It was also effective in preventing leakage of body fluids because it did not create any gaps. In addition, since the exterior body in the crotch area is highly stretchable, a good feeling of wearing was obtained, and the shoe did not feel uncomfortable at all even when worn.

1 Pants-type absorbent article 11 Waist opening 12 Leg opening 13 Front region 13A Front waist region 13B Front waist region 14 Inseam region 15 Back region 15A Back waist region 15B Back waist region 20 Absorbent main body 24 Top sheet 25 Back sheet 29 Absorbent body 30 Exterior body 301 Exterior nonwoven fabric sheet 302 Interior nonwoven fabric sheet 303 Side seal portion 311 Waist area elastic elastic member 312 Front waist area elastic elastic member 313 Back waist area elastic elastic member 314 Leg circumference elastic elastic member

Claims (6)

An exterior body having a front region divided from the upper part into a front waist region and a front waist region, a rear region divided from the upper part into a rear waist region and a rear waist region, and a crotch region located between these regions. and an absorbent body including a liquid-permeable top sheet, a liquid-impermeable back sheet, and an absorbent body disposed between these , wherein the exterior body is on the non-skin side of the absorbent body. An overlapping pants-type absorbent article,
Both side edges of the front region and both side edges of the rear region are respectively joined to form a waist opening at the upper part of the front region and the rear region, and leg openings at both left and right sides of the crotch region. A side seal part that
a plurality of waist region elastic elastic members provided along the width direction in the front waist region and the rear waist region;
A plurality of elastic stretchable front waist regions are provided along the width direction in the front waist region and the rear waist region, respectively, and are arranged so as not to overlap with the absorbent main body in the thickness direction of the pants-type absorbent article. a member and a plurality of rear waist region elastic stretchable members;
an exterior body of the front region including a non-skin-side nonwoven fabric, a skin-side nonwoven fabric, and the waist region elastic stretchable member or the waist region elastic stretchable member disposed therebetween;
The non-skin side non-woven fabric, the skin-side non-woven fabric, and the waist region elastic elastic member or the waist region elastic elastic member disposed between them, and are provided separately from the exterior body of the front region. an exterior body in the rear area;
The crotch area is made of a flexible polyurethane foam sheet that is disposed over the entire area of the crotch area and includes a flexible polyurethane foam that is expandable and contractible in all directions, and is joined to each exterior body in the front area and the rear area. an exterior body;
A pants-type absorbent article, wherein the leg opening periphery and the crotch region have regions where the elastic elastic member is not arranged. The pants-type absorbent article according to claim 1, wherein the basis weight of the flexible polyurethane foam sheet that is the exterior body of the crotch region is 70 g/m ² or more and 300 g/m ² or less . The pants-type absorbent article according to claim 1 or 2, wherein the flexible polyurethane foam sheet that is the exterior body of the crotch region has a thickness of 1.0 mm or more and 4.0 mm or less. The pants-type absorbent article according to any one of claims 1 to 3, wherein the flexible polyurethane foam sheet that is the exterior body of the crotch region has an MIU of 0.3 or more and 1.0 or less. The pants-type absorbent article according to any one of claims 1 to 4, wherein the flexible polyurethane foam sheet that is the exterior body of the crotch region has an MMD of 0.01 or more and 0.03 or less. The pants-type absorbent according to any one of claims 1 to 5, wherein the elastic polyurethane foam sheet that is the exterior body of the crotch region has an elongation stress of 3.0 N or more and 4.5 N or less when stretched by 60 mm. Goods.