JP7382252B2 - Pants-type absorbent article - Google Patents

Description

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

A conventional pants-type absorbent article 100 shown in FIG. 6 has elastic elastic members such as rubber threads arranged around the waist, waist, buttocks, etc. in order to make it easy to wear and to obtain a good fit while wearing. (Patent Document 1). The arrangement of the elastic stretchable members forms gathers 110, 111 and wrinkles with relatively large areas, which are major features in the appearance of the pants-type absorbent article 100. These bring about a big difference in appearance from cloth underwear. In particular, cloth underwear does not have transparent rubber threads around the waist or hips, and many large wrinkles that occur around them. The above-mentioned difference in appearance is not desirable for a wearer who wants to keep the wearing of the pants-type absorbent article secret from a third party. Therefore, there is a strong demand for pants-type absorbent articles that have an appearance more similar to cloth underwear.

In order to improve the appearance problems of pants-type absorbent articles, a composite sheet in which a nonwoven fabric as a surface material and a stretchable film are laminated as an exterior body has been proposed. Patent Document 2 discloses a laminate of a spunbond nonwoven fabric and a stretchable film that can be stretched in two orthogonal directions as an exterior body for diapers and personal care products, and the stretchable film is made of polyurethane, polyetheramide, and polyester. A biaxially elastically extensible breathable composite sheet is disclosed that is a film comprising one or more polymers selected from the group consisting of elastomers.

Japanese Patent Application Publication No. 10-137287 Japanese Patent Application Publication No. 2008-279774

Conventional pants-type absorbent articles that have a composite sheet as an exterior body have an appearance similar to cloth underwear, but since all the materials that make up the composite sheet are synthetic resins, they are made of natural fibers such as cotton and silk. The problem is that it is inferior to cloth underwear in terms of texture and sweat absorption, and it tends to get stuffy. On the other hand, some natural fibers may contain protein-based ingredients that can easily cause rashes on wearers with highly sensitive skin, so the use of natural fibers does not necessarily provide good performance for pants-type absorbent articles. It does not necessarily mean that it will be granted.

An object of the present invention is to provide a pants-type absorbent article that uses a composite sheet as an exterior body, has an appearance similar to cloth underwear, has a good texture, and is less likely to cause skin problems such as itching and rashes due to stuffiness. .

In order to solve the above-mentioned problems, the present inventor has conducted extensive research and found that a composite sheet containing a predetermined cotton-containing composite nonwoven fabric is used as a surface material, and the composite nonwoven fabric and a stretchable film are laminated as an exterior body. The inventors have discovered that a desired pants-type absorbent article can be obtained by doing so, and have completed the present invention. The present invention provides, as preferred embodiments, pants-type absorbent articles as described in (1) to (5) below, for example.

(1) an absorbent main body including a liquid-permeable top sheet, a liquid-impermeable back sheet, and an absorbent body disposed between the top sheet and the back sheet, and supporting the absorbent main body; A pants-type absorbent article comprising: an exterior body divided into a ventral part, a crotch part, and a dorsal part, the ventral part and the dorsal part each include a composite sheet, and the composite sheet comprises: A plurality of cotton-containing composite nonwoven fabrics, a stretchable film disposed between the cotton-containing composite nonwoven fabrics, and a plurality of cotton-containing composite nonwoven fabrics and the stretchable film integrated with each other at a distance from each other in the plane direction. an adhesive portion, and the cotton-containing composite nonwoven fabric includes a nonwoven fabric and a cotton fiber layer laminated on at least one surface of the nonwoven fabric.
(2) In the exterior body, the basis weight per sheet of the cotton-containing composite nonwoven fabric is 40 g/m ² or more and 60 g/m ² or less, the nonwoven fabric is a spunbond nonwoven fabric, and the spunbond nonwoven fabric and the cotton The pants-type absorbent article according to (1) above, wherein the weight composition ratio with the fiber layer is 40/60% by weight or more and 10/90% by weight or less.
(3) The pants-type absorbent article according to (1) or (2) above, wherein the composite sheet is an integrated product including the adhesive portion formed by heat fusion bonding and/or ultrasonic bonding.
(4) The pants-type absorbent article according to any one of (1) to (3) above, wherein the composite sheet has an elongation rate in the stretching direction of 150% or more and 270% or less.
(5) The pants-type absorbent article according to any one of (1) to (4) above, further comprising an elastic stretchable member disposed extending from the abdominal part to the back part via the crotch part.

According to the present invention, there is provided a pants-type absorbent article that uses a composite sheet as an exterior body, has an appearance similar to cloth underwear, has a good texture, and is less likely to cause stuffiness or allergies.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective view schematically showing the appearance of a pants-type absorbent article according to a first embodiment of the present invention. FIG. 2 is a schematic development view of the pants-type absorbent article shown in FIG. 1. FIG. 3 is a schematic cross-sectional view in the width direction taken along the line XX' in FIG. 2. FIG. It is a schematic plan view which expands and shows an example of each embodiment of an adhesive part and its arrangement pattern. FIG. 1 is a schematic diagram showing an embodiment of a manufacturing example of a composite sheet. FIG. 1 is a perspective view showing the appearance of a conventional pants-type absorbent article.

The pants-type absorbent article 1 according to the first embodiment will be described below with reference to the drawings. In this specification, it is defined as follows. 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 longitudinal direction is a direction spanning the front and back of the wearer when wearing the pants-type absorbent article 1, the width direction is a direction perpendicular to the longitudinal direction, and the thickness direction is a direction that includes the longitudinal direction and the width direction. This is a direction substantially perpendicular to a plane (for example, the plane shown in FIG. 2). When the pants-type absorbent article 1 is worn on the body, the surface that contacts or faces the wearer's skin is called the skin side, and the surface that contacts or faces the wearer's clothing is called the non-skin side. , and so on. 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 an external perspective view of the pants-type absorbent article 1, FIG. 2 is a schematic developed plan view of the pants-type absorbent article 1, and FIG. 3 is a cross-sectional view of the pants-type absorbent article 1 in the width direction. . Each figure does not specify the shape, size, or size relationship of each component of the pants-type absorbent article 1, such as the exterior body 10 and the absorbent main body 20. The dimensions of each component can be appropriately selected from a wide range depending on the purpose of the pants-type absorbent article 1, the wearer's age, body shape, etc. In FIG. 3, the layers of the constituent members are stacked without any gaps, but this embodiment also includes embodiments in which at least one gap exists between at least one layer.

As shown in FIGS. 1 to 3, the pants-type absorbent article 1 of the present embodiment includes an exterior body 10 that constitutes its external shape, and is supported in a predetermined area of the exterior body 10, and extends from the front and back of the wearer's groin area. and an absorbent main body 20 having a substantially band-like shape in the front-rear direction and covering the absorbent main body 20 from the front to the back. The exterior body 10 has a ventral part 11 that mainly contacts the wearer's abdomen, a dorsal part 12 that mainly contacts the wearer's back, and is located between the ventral part 11 and the dorsal part 12. The crotch area 13 mainly contacts the wearer's crotch area. The exterior body 10 mainly supports the absorbent body 20 on the skin side of the crotch area 13, and is arranged so that part or all of the absorbent body 20 overlaps the crotch area 13. The absorbent body 20 absorbs and retains the wearer's body fluids.

The longitudinal dimension of the pants-type absorbent article 1 when unfolded as shown in FIG. 2 is, for example, in the range of 600 mm or more and 1000 mm or less, and the width direction dimension is, for example, in the range of 450 mm or more and 900 mm or less. The pants-type absorbent article 1 having this unfolded dimension is made into a pants-type absorbent article for adults of various sizes such as S size, M size, and L size after arranging elastic stretchable members in predetermined areas as necessary. Article 1 may be used. The pants-type absorbent article 1 can be used, for example, as a paper diaper, a sanitary napkin, a disposable diaper for incontinence, or the like.
Hereinafter, each component of the pants-type absorbent article 1 of this embodiment will be explained in more detail in the order of the absorbent main body 20 and the exterior body 10.

<Absorbent body>
The absorbent main body 20 of the present embodiment includes a liquid-permeable top sheet 21 disposed relatively on the skin side, and a liquid-impermeable top sheet 21 disposed relatively on the non-skin side opposite to the top sheet 21. The absorbent body 23 is arranged between the top sheet 21 and the back sheet 22, and the three-dimensional gathers 24 are included. It has a unique structure. The absorbent main body 20 is arranged mainly on the skin side of the crotch area 13 of the exterior body 10 so as to extend from the ventral side part 11 to the dorsal side part 12. The absorbent main body 20 is fixed to the exterior body 10 using an adhesive such as hot melt, thermal fusion, ultrasonic bonding, or the like.

(Top sheet)
As the top sheet 21 of the present embodiment, a base material having liquid permeability that allows bodily fluids to move to the absorbent body 23 can be used without particular limitation, such as a nonwoven fabric such as a thermal bond nonwoven fabric, a thermal bond nonwoven fabric/spunbond fabric, etc. Examples include composite nonwoven fabrics that are laminates of nonwoven fabrics, open films such as open polyethylene films, foamed films such as polyethylene foams and urethane foams, and multilayer sheets obtained by laminating two or more of these. Further, the top sheet 21 is preferably subjected to embossing or perforation on the surface in order to improve liquid permeability. As for the processing method, any known method can be used without any limitation. Further, in order to reduce irritation to the skin, it is also preferable for the top sheet 21 to contain a lotion, an antioxidant, an anti-inflammatory component, a pH adjuster, an antibacterial agent, a humectant, and the like. Furthermore, in terms of strength and workability, the basis weight of the top sheet 21 is, for example, in the range of 14 g/m ² or more and 40 g/m ² or less. The shape of the top sheet 21 is not particularly limited, but may be any shape as long as it covers the absorbent body 23 in order to guide liquid such as urine to the absorbent body 23.

(back seat)
As the backsheet 22 of this embodiment, a liquid-impermeable base material that does not allow leakage of body fluids held by the absorber 23 can be used without particular limitation, such as a nonwoven fabric, a resin film, or a laminate of two or more of these. Examples include multi-layer sheets that are bodies. The manufacturing method of the nonwoven fabric is not particularly limited, and examples thereof include spunbond nonwoven fabric, meltblown nonwoven fabric, spunbond nonwoven fabric/meltblown nonwoven fabric laminate, spunbond nonwoven fabric/meltblown nonwoven fabric/spunbond nonwoven fabric laminate, and the like. Examples of the resin film include polyester film, polyvinyl alcohol film, polyethylene film, polypropylene film, and a composite sheet that is a laminate of polyethylene and polypropylene. Further, in order to prevent stuffiness when worn, the back sheet 22 preferably has moisture permeability. Examples of methods for imparting moisture permeability include adding a filler to the base resin film and embossing the backsheet 22 for perforation. The basis weight of the backsheet 22 is not particularly limited, but is, for example, in the range of 15 g/m ² or more and 60 g/m ² or less.

(Absorber)
The absorber 23 of this embodiment includes, for example, an absorbent base material and an absorbent component supported on the absorbent base material. As the absorbent base material, any absorbent base material that is generally included in absorbent articles such as sanitary napkins, diapers, and urine pads can be used without particular limitation, and examples thereof include flap pulp, hydrophilic sheets, and the like. Examples of the flap pulp include wood pulp, synthetic fibers, and cotton-like defibrated materials such as non-wood pulps such as synthetic resin fibers. Examples of the hydrophilic sheet include tissue, absorbent paper, and hydrophilic nonwoven fabric. Moreover, a spread body of acetate tow can be used as an absorbent base material. Known absorbent components can be used without particular limitation, such as super absorbent polymers (hereinafter also referred to as "SAP"). As the superabsorbent polymer, known ones can be used, and among them, polyacrylates are preferred, and sodium polyacrylate is more preferred, from the viewpoint of the amount of body fluid absorbed per area.

The absorbent body 23 is configured in a single-layer or multi-layer sheet shape using, for example, the above-mentioned absorbent base material and absorbent component. Among these, those formed by mixing a hydrophilic fiber matrix of a web of fluff pulp, such as wood pulp fluff, with SAP particles are preferred. Further, in order to prevent leakage of SAP particles and to stabilize the shape of the absorber 23, it is preferable to wrap the absorber 23 in a hydrophilic sheet (not shown) such as a tissue. Furthermore, embossing the surface of the absorbent body 23 is preferable because it controls the diffusion of body fluids and allows the absorbent body 23 to easily deform according to the user's body shape. The basis weight of the superabsorbent polymer in the absorbent body 23 is not particularly limited, but is, for example, in the range of 50 g/m ² or more and 500 g/m ² or less.

(3D gathers)
The three-dimensional gathers 24 are provided, for example, to prevent side leakage of body fluids. In the three-dimensional gathers 24 of this embodiment, one end in the width direction is fixed along the longitudinal direction near both ends in the width direction of the skin side of the back sheet 22, and a middle part in the width direction is fixed near both ends in the width direction of the skin side of the top sheet 21. A three-dimensional gather sheet 24b that is fixed along the longitudinal direction and whose other end in the width direction is a free end; It includes an elastic elastic member 24a for three-dimensional gathers that imparts elasticity. The other end in the width direction, which has the ability to stand up, is stretchable and deformable according to the wearer's body shape.

For the three-dimensional gather sheet 24b, for example, various nonwoven fabrics can be used without limitation, and for the three-dimensional gather elastic elastic member 24a, a general elastic elastic member such as thread rubber can be used without particular limitation. Note that one widthwise end (fixed end) of the three-dimensional gathered sheet 24b joins the periphery of the top sheet 21 and the periphery of the backsheet 22 near both widthwise ends of the skin side of the backsheet 22, and encloses the absorbent body 23. It may be fixed along the longitudinal direction near both widthwise ends of the bag, near both widthwise ends of the skin side of the top sheet 21, or near both widthwise ends of the non-skin side of the backsheet 22. The absorbent main body 20 of this embodiment also includes an embodiment that does not include the three-dimensional gathers 24.

<Exterior body>
The exterior body 10 includes a ventral part 11 that mainly contacts the wearer's ventral side, a dorsal part 12 that mainly contacts the wearer's dorsal side, and a space between the ventral part 11 and the dorsal part 12. The absorbent main body 20 is supported mainly on the skin side of the crotch area 13, and has a crotch area 13 interposed therebetween and mainly in contact with the wearer's crotch area. Furthermore, as shown in FIGS. 2 and 3, the exterior body 10 of the present embodiment has a pair of left and right leg gathers that extend from the ventral side part 11 to the crotch area 13 and to the dorsal side part 12 along the widthwise end. It is equipped with 16.

In this embodiment, a composite sheet 17 is used for the ventral side part 11 and the dorsal side part 12. On the other hand, the crotch portion 13 may be made of the same composite sheet 17 as the abdominal part 11 and the back part 12, or may be made of a conventional nonwoven fabric. In order to reduce the sluggishness when worn due to the thickness of the material in the crotch portion, a non-woven fabric, for example, is used for the crotch portion 13 from the viewpoint of making the material thickness as thin as possible. The type of nonwoven fabric is not particularly limited, and examples include nonwoven fabrics such as thermal bond nonwoven fabric, air-through nonwoven fabric, and spunbond nonwoven fabric. These nonwoven fabrics include fibers made of thermoplastic resin such as polyethylene, polypropylene, and polyester. It is preferable to include it as In addition, from the viewpoint of obtaining the crotch portion 13 having a predetermined ventilation resistance value and strength, the basis weight of the nonwoven fabric of the crotch portion 13 is, for example, in the range of 15 g/m ² to 40 g/m ² or 18 g/m ² to 40 g. / ^m2 or less.

<Composite sheet>
When the composite sheet 17 is used for the ventral part 11 and the dorsal part 12, as shown in FIG. 1, the amount of gathers and wrinkles on the surface can be significantly reduced compared to the gathers 110 and 111 shown in FIG. Therefore, the possibility that others will recognize that the pants-type absorbent article 1 is worn is greatly reduced compared to the conventional pants-type absorbent article 100 shown in FIG. Furthermore, since the composite sheet 17 disposed on the ventral side part 11 and the dorsal side part 12 has good breathability, the pants-type absorbent article 1 itself has good breathability, even when worn for a long time. It is extremely difficult to get stuffy and provides a good feeling of wearing.

The composite sheet 17 of the present embodiment includes two cotton-containing composite nonwoven fabrics 14 (hereinafter also simply referred to as "composite nonwoven fabrics 14"), a stretchable film 15 interposed between the two composite nonwoven fabrics 14, A plurality of bonding parts 30 are provided between the composite nonwoven fabric 14 and the stretchable film 15, spaced apart from each other in the plane direction, and integrating the composite nonwoven fabric 14 and the stretchable film 15. The composite sheet 17 of this embodiment includes two composite nonwoven fabrics 14, but is not limited to this, and includes three or more composite nonwoven fabrics 14 and two or more stretchable films 15 disposed between them. It may also include. The composite nonwoven fabric 14 is, for example, a polypropylene spunbond nonwoven fabric hydroentangled with cotton fibers to form a sheet, as disclosed in US Pat. No. 5,284,703.

(Cotton-containing composite nonwoven fabric)
The cotton-containing composite nonwoven fabric 14 of this embodiment mainly includes a cotton fiber layer and a nonwoven fabric as its constituent materials. The cotton fiber layer has too high wettability to liquid and too low strength, so it is difficult to use it alone as a component of the absorbent article 1. In contrast, according to the present embodiment, by reinforcing a cotton fiber layer that is so thin that it cannot be used as a component of the absorbent article 1 by laminating or integrating it with a nonwoven fabric, the cotton fiber layer is easily wetted. This makes it possible to exhibit a practically sufficient level of liquid absorption and liquid dispersion. In addition, the cotton fiber layer has excellent texture and softness, improving the feeling of wearing. Therefore, the pants-type absorbent article 1 of this embodiment using the cotton-containing composite nonwoven fabric 14 has the liquid absorbency, absorption rate, and liquid diffusivity in the absorbent body 23 required for a pants-type absorbent article. In addition to having a high level of various properties such as texture and comfort, it also has the advantage of being less likely to cause skin problems.

The cotton-containing composite nonwoven fabric 14 includes a nonwoven fabric and a cotton fiber layer laminated on at least one surface of the nonwoven fabric. A preferred embodiment of a cotton-containing composite nonwoven fabric includes a nonwoven fabric and a cotton fiber layer integrated into at least one surface of the nonwoven fabric. Here, "integration" means that at least before and after use of the absorbent article 1, the nonwoven fabric and the cotton fiber layer are in a state where even partial separation does not occur and the function thereof is not significantly reduced. The basis weight of the nonwoven fabric is, for example, in the range of 7 g/m ² or more and 30 g/m ² or less, and the basis weight of the cotton fiber layer is, for example, in the range of 30 g/m ² or more and 50 g/m ² or less. By setting the basis weights of the nonwoven fabric and the cotton fiber layer within the above ranges, it becomes easy to adjust the basis weight of the cotton-containing composite nonwoven fabric 14 to an appropriate range as described below.

Among the cotton-containing composite nonwoven fabrics 14, a monolithic fabric formed by hydroentanglement is preferable. The integrated product is, for example, a cotton-containing composite nonwoven fabric 14 in which a cotton fiber layer is provided on the surface of the nonwoven fabric by interlacing wood pulp fibers with a water jet and integrating them without using a binder. In such a cotton-containing composite nonwoven fabric 14, the fibers constituting the nonwoven fabric and the cotton fibers are intertwined with each other on one surface of the nonwoven fabric to integrate the cotton fiber layer, and some of the cotton fibers extend through the nonwoven fabric in the thickness direction. It penetrates through and is exposed on the other side, and the nonwoven fabric and the cotton fiber layer are extremely strongly bonded.

The weight ratio of the nonwoven fabric to the cotton fiber layer (nonwoven fabric/cotton fiber layer) is, for example, in the range of 40/60% by weight or more and 10/90% by weight or less. If the content of the cotton fiber layer is less than 40% by mass, the cotton-containing composite nonwoven fabric 14 tends to have poor texture and sweat absorption, and tends to become stuffy. If it exceeds 60% by mass, the cotton-containing composite nonwoven fabric 14 It tends to become hard. The nonwoven fabric to be integrated with the cotton fiber layer is not particularly limited, but spunbond nonwoven fabric is preferable from the viewpoints of support for the cotton fiber layer, strength, softness, texture, etc. of the composite nonwoven fabric 14 as a whole, and polypropylene is preferable. A spunbond nonwoven fabric containing fibers is more preferred, and a spunbond nonwoven fabric consisting of polypropylene fibers is even more preferred.

The basis weight of the cotton-containing composite nonwoven fabric 14 is, for example, in ^the range of 40 g/m ² to 60 g/m 2 or in the range of 40 g/m ² to 50 g/m ² from the viewpoint of strength, texture, and the like. If it is less than 40 g/m ² , the cotton-containing composite non-woven fabric ¹⁴ will become softer, but it will not be stably fixed during manufacturing, and the manufacturing yield will tend to decrease. By increasing the hardness and thickness, higher energy is required when integrating with the stretchable film 15, and there is a growing concern that the load on manufacturing equipment will increase.

(stretch film)
The stretchable film 15 is included in the composite sheet 17 in a state where it is stretched in the stretch direction (the elongation rate in the stretch direction is within a predetermined range). The stretchable film 15 is not particularly limited as long as it has stretchability, but a film made of a synthetic resin that exhibits stretchability when formed into a film is preferred. Examples of the synthetic resin include polyester elastomers, polyolefin elastomers, thermoplastic polyurethane resins, polyamide resins, and alloys of two or more of these. Among these, from the viewpoint of cost and elasticity, a film containing a polyurethane resin is preferred, and a film made of a polyurethane resin is more preferred. From the viewpoint of obtaining a composite sheet 17 having a predetermined ventilation resistance value and elongation rate in the stretching direction, the thickness of the stretchable film 15 is, for example, in the range of 20 μm or more and 60 μm or less, and the stretch rate of the stretchable film 15 in the stretching direction is, for example, The range is 150% or more and 270% or less.

(Adhesive part)
The bonded portion 30 is a portion where the composite nonwoven fabric 14 and the stretchable film 15 are bonded and integrated. In this specification, the integration of the composite nonwoven fabric 14 and the stretchable film 15 means that the composite nonwoven fabric 14 and the stretchable film 15 are bonded to each other, and this bonding occurs at least until the end of use of the pants-type absorbent article 1. means that it is maintained. The adhesive portion 30 has a predetermined planar shape, which will be described later. Further, it is preferable to use a method such as heat fusion bonding or ultrasonic bonding to integrate the cotton-containing composite nonwoven fabric 14 and the stretchable film 15. By using these integration methods, the adhesive portion 30 having a predetermined planar shape can be easily formed. The integration method will also be described later.

FIG. 4 is an enlarged schematic plan view showing an example of the planar shape and arrangement pattern of the adhesive portions 30 on the surface of the composite sheet 17. As shown in FIG. As shown in FIG. 4, the composite sheet 17 is integrated by a plurality of adhesive parts 30, which has a planar shape that is a combination of a square and a circle in plan view. The adhesive portion 30 has a planar shape in which a corner derived from a quadrilateral and a partial arc line derived from a circle are connected, and preferably a plurality of corner portions derived from a quadrilateral and a plurality of corner portions derived from a circle are connected. has a planar shape in which the partial circular arc lines are connected.

More specifically, the adhesive portion 30 of this embodiment has a shape in which a rectangle 40 extending orthogonally to the stretching direction Y of the composite sheet 17 and a circle 41 are integrated, and the diagonal line of the rectangle 40 The intersection point and the center of the circle 41 coincide (overlap), and the diameter of the circle 41 is longer than the short side of the rectangle 40 and shorter than the long side. The adhesive part 30 of this embodiment has four corners derived from a rectangle 40 and two partial arc lines derived from a circle 41, one of which is in one direction of the expansion/contraction direction Y and the other is protrude in the other direction of expansion and contraction. In the adhesive part 30 of this embodiment, the rectangular portion 40 extends in a direction substantially perpendicular to the stretching direction Y, but the present invention is not limited to this. It may be tilted at any angle such as 0.degree., 45.degree., 60.degree., or 90.degree. Hereinafter, the inclination of the rectangular portion 40 with respect to the expansion/contraction direction is also simply referred to as "inclination Z" (Table 1). Such adhesive parts 30 are arranged in a pattern X and/or a pattern Y along the stretching direction Y of the composite sheet 17. A predetermined phase difference may be provided for each column in pattern X or Y. Further, the adhesive portions 30 may be arranged in a grid pattern, a grid pattern, or the like.

The composite sheet 17, which is integrated with a plurality of adhesive parts 30 having such a planar shape, has appropriate mechanical strength, elasticity, and tightening properties, so it is easy to form gathers by disposing elastic elastic members. It is very suitable as the exterior body of the pants-type absorbent article 1 because it does not require the composite sheet and the low air permeability, which is a drawback of conventional composite sheets, has been improved.

In FIG. 4, a preferable example of each dimension of the adhesive part 30 is shown. The dimension (length in the stretching direction) of the rectangular 40 part of the adhesive part 30 indicated by the symbol "A" is 250% stretched in the stretching direction Y. For example, the dimension in the direction substantially perpendicular to the expansion/contraction direction Y of the adhesive portion 30, which is indicated by the symbol "B", is in the range of, for example, 0.2 mm or more and 0.4 mm or less, for example, 0.8 mm or more and 2.0 mm or more. The diameter of the circular portion 41 of the adhesive part 30, which is in the range of 0 mm or less and is indicated by the symbol "C", is, for example, in the range of 0.3 mm or more and 0.8 mm or less, and is indicated by the symbol "D ₁ ". When the composite sheet 17 is stretched by 250% in the stretching direction Y, the shortest length of the adhesion parts 30 adjacent to each other in the stretching direction Y is, for example, in the range of 1.0 mm or more and 3.0 mm or less, and has the code "D ₂ The shortest length of the adhesive parts 30 adjacent in the direction substantially perpendicular to the expansion/contraction direction Y is, for example, in the range of 1.0 mm or more and 3.0 mm or less, and the shortest length is in the range of 1.0 mm or more and 3.0 mm or less. When the composite sheet 17 is stretched by 250% in the stretching direction Y, the shortest length of the adhesive parts 30 adjacent to each other in the stretching direction Y is, for example, in the range of 2.0 mm or more and 5.0 mm or less. By setting the adhesive portion 30 within the above range, the breathability of the composite sheet 17 is further improved, and the decrease in durability of the stretchable film 15 is alleviated.

In the composite sheet 17, the adhesive area ratio of the adhesive portion 30 is in a range of, for example, 4% or more and 18% or less. Here, the adhesion area ratio is the ratio of the total area of the adhesive portions 30 present in the unit area of the composite sheet 17, expressed as a percentage. If the adhesion area ratio is less than 4%, the air permeability of the composite sheet 17 tends to decrease. On the other hand, when the adhesive area ratio exceeds 18%, the strength of the composite sheet 17 tends to decrease.

(Stretching properties of composite sheet, etc.)
As mentioned above, the composite sheet 17 of this embodiment is an integrated product of two cotton-containing composite nonwoven fabrics 14 and one stretchable film 15 at the adhesive part 30, and the cross-sectional view is unidirectional. The composite sheet 17 may have a three-dimensional shape that is layered and has a flat surface, or may have a three-dimensional shape that has a wavy line shape extending in one direction in cross section and has regular irregularities on the surface. A composite sheet 17 may also be used. From the viewpoint of texture, touch, cushioning properties, etc., the latter composite sheet 17 whose cross-sectional view has a wavy line shape extending in one direction is preferable.

The ventilation resistance value of the composite sheet 17 measured after being stretched by 250% in the stretching direction is, for example, in the range of 0.01 kPa·s/m or more and 0.5 kPa·s/m or less, or 0.05 kPa·s/m or more. The range is 0.35 kPa·s/m or less. Since the composite sheet 17 has a ventilation resistance value within the above range, even if the composite sheet 17 is used in the crotch area 13 and the absorbent main body 20 is attached to the skin side of the crotch area 13, the ventral area 11 and the dorsal side Good air permeability is maintained by the composite sheet 17 constituting the section 12. If the ventilation resistance value is less than 0.01 kPa·s/m, the heat retention of the pants-type absorbent article 1 tends to decrease, and the feeling of wearing tends to decrease. When the ventilation resistance value exceeds 0.5 kPa·s/m, the breathability of the pants-type absorbent article 1 decreases, and there is a tendency for stuffiness to occur when worn.

The elongation rate of the composite sheet 17 in the stretching direction is, for example, in the range of 150% or more and 270% or less, or in the range of 180% or more and 250% or less. Here, the elongation rate in the stretching direction is the tensile stress ( This is the ratio of the length increased by stretching to the natural length in the non-stretched state when a load (N/50 mm) is applied. The elongation rate can be measured using, for example, an autograph manufactured by Shimadzu Corporation. Since the elongation rate of the composite sheet 17 in the stretching direction is within the above range, the wearer can easily put on and take off the wearer, have appropriate tightness and feel comfortable to wear, and furthermore, the pants type is less prone to slipping down and provides a sense of security. Absorbent article 1 is obtained.

For example, the composite sheet 17 has an elongation load of 0.8 N/50 mm or more and 2.0 N/50 mm or less when elongated by 120% in the elongation/contraction direction, and 2. It has an extension load of 0 N/50 mm or more and 3.5 N/50 mm or less. Note that since the elongation rate varies depending on the wearer's body shape, elongation loads of 120% and 150% were specified. By doing this, there will be no difference in fit depending on body type. Further, the composite sheet 17 has an elongation rate in the stretching direction of, for example, 200% or more and 270% or less. Therefore, since it is possible to stretch 200% or more compared to conventional products, it is possible to provide a pants-type absorbent article 1 that is easy for the wearer to put on and take off.

Further, the composite sheet 17 has, for example, a breaking elongation in the range of 210% or more and 280% or less in the stretching direction. The elongation at break is defined as the elongation at break, where L1 is the length of the composite sheet 17 at its natural length in a non-stretchable state, and L2 is the length when the composite sheet 17 is stretched in the stretching direction and broken. (L2/L1)×100(%). Having a breaking elongation within this range has the effect that the pants will not be stretched or torn easily even if the pants are opened wide when putting on and taking off. The elongation at break can be measured using, for example, an autograph manufactured by Shimadzu Corporation.

<Method for manufacturing composite sheet>
The composite sheet 17 can be produced, for example, by the manufacturing method shown in FIG. FIG. 5 is a drawing schematically showing a method for manufacturing the composite sheet 17. As shown in FIG. FIG. 5(a) is a schematic side view showing all steps of the method for manufacturing the composite sheet 17. FIG. 5(b) is an enlarged schematic cross-sectional view showing the third step (bonding step). The manufacturing method shown in FIG. 5 is a method using ultrasonic bonding, thermal fusion, etc., and includes first to third steps in this order.

In the first step, the elastic film 15 wound around the feeding roller 51 is transported while applying a predetermined tension. The stretchable film 15 is transported while being stretched in the transport direction with a predetermined tension. The predetermined tension is a tension that stretches the stretchable film 15, for example, to a range of 200% or more or a range of 250±30%.

In the second step following the first step, the respective nonwoven fabrics 14 wound around the two feeding rollers 52 are laminated on top and bottom of the stretchable film 15 that is conveyed in a stretched state to obtain a laminate before integration.
In the third step following the second step, the pre-integrated laminate is passed through the pressure contact portion (hereinafter also referred to as “nip portion”) of the first and second bonding rollers 53 and 54 to form a predetermined adhesive portion 30. A composite sheet 17 is obtained. The first bonding roller 53 is provided with a plurality of recesses 55 extending in the width direction and having predetermined dimensions and a predetermined internal space shape at predetermined intervals in the circumferential direction on the circumferential surface of the first joining roller 53 . The second bonding roller 54 has a convex portion on its peripheral surface that extends in the width direction and has a predetermined size and a predetermined three-dimensional shape (a three-dimensional shape that allows the tip portion to be inserted into the recess 55 with the interposition of the laminate). A plurality of 56 are provided at predetermined intervals in the circumferential direction. The first and second bonding rollers 53 and 54 are engaged with each other so that the tip of the convex portion 56 can be inserted into the concave portion 55, and are pressed together with a predetermined pressure. In the nip portion of the first and second bonding rollers 53 and 54, seal lines that are substantially continuous in the width direction of the roller circumferential surface are formed at intervals of, for example, 0.5 mm or more and 2.0 mm or less in the expansion and contraction direction. ing. Either or both of the first and second bonding rollers 53 and 54 are equipped with an ultrasonic generator or a heating device, and can apply ultrasonic waves to the inner wall surface of the recess 55 or at least the tip portion of the convex portion 56. Or it is configured to be heated.

In the third step, the laminate obtained in the second step is passed through the nip portion of the first and second bonding rollers 53 and 54 under pressure, so that the inner wall surface of the recess 55 and the tip portion of the convex portion 56 are bonded. By applying ultrasonic waves or heating the seal wire that is the contact point, a plurality of adhesive parts 30 having a predetermined planar shape are formed, and the nonwoven fabric 14 and the stretchable film 15 are integrated by the plurality of adhesive parts 30, A composite sheet 17 with few surface wrinkles and smooth texture is obtained. That is, a plurality of adhesive parts 30 having the planar shape shown in FIG. 4 are formed at predetermined intervals shown in FIG. 4. A composite sheet 17 in which the nonwoven fabric 14 and the stretchable film 15 are integrated is obtained.

<Leg gathers>
As shown in FIGS. 2 and 3, the leg gathers 16 includes an elastic elastic member 16a and a leg gathers sheet 16b. The elastic stretchable member 16a is not particularly limited, and for example, a rubber thread or the like can be used. As the leg gather sheet 16b, for example, various nonwoven fabrics can be used. By providing the leg gathers 16, it becomes possible to expand and contract not only the direction of expansion and contraction (width direction) but also the direction that intersects the direction of expansion and contraction (longitudinal direction), improving the fit around the crotch area. The shape of the leg gathers 16 does not easily appear on the surface of clothing when the pants-type absorbent article 1 is worn. Note that the pants-type absorbent article 1 of this embodiment also includes an embodiment that does not include the leg gathers 16.

<Method for manufacturing pants-type absorbent article>
The pants-type absorbent article 1 is a conventional pants-type absorbent article, except that the composite sheet 17 is used as the exterior body 10 of the ventral part 11 and the dorsal part 12, or the ventral part 11, the dorsal part 12, and the crotch part 13. It can be produced in the same way as sex products. For example, the ventral part 11 and the dorsal part 12 are made of the composite sheet 17, the crotch part 13 is made of a conventional nonwoven fabric laminate or the composite sheet 17, and these are joined in the longitudinal direction in a predetermined order to form the exterior. A process of obtaining the body 10, a process of fixing the absorbent body 20 to a predetermined position (mainly the crotch area 13) on the skin side of the exterior body 10, and a process of fixing the absorbent body 20 on the skin side of the exterior body 10 near both widthwise ends of the absorbent body 20. The pants-type absorbent article 1 is obtained by the manufacturing method including the step of joining the leg gathers 16 to the legs. In addition, when the ventral side part 11, the dorsal side part 12, and the crotch part 13 are constructed from the composite sheet 17, the composite sheet 17 is die-cut into a predetermined shape (for example, the shape shown in the developed plan view shown in FIG. 2). It may also be used as the exterior body 10. The pants-type absorbent article 1 thus obtained is manufactured into a product by folding and bagging in a predetermined order.

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 described in the above embodiments and examples. It will be apparent to those skilled in the art that various changes or improvements can be made to the embodiments described above. 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.
<Examples 1 to 3, Comparative Examples 1 to 4>

(Creation of exterior body)
The exterior body of the ventral part, dorsal part, and crotch part has the planar shape and arrangement shown in FIG. 4 (array X and arrangement Y are arranged alternately in the direction perpendicular to the rows), and 1 (dimensions A, B, C, D ₁ , D ₂ , and E shown in FIG. 4), and each bonded part of Examples 1 to 3 formed by ultrasonic bonding, 2 A polyurethane film (thickness 20 μm, stretch rate 250% in the stretch direction) was placed between sheets of cotton-containing composite nonwoven fabric (basis weight 40, 50, and 60 g/m ² in the order of Examples 1, 2, and 3). , using an integrated composite sheet. In addition, in Comparative Examples 1 to 3, a polypropylene spunbond nonwoven fabric (basis weight 18, 25, and 40 g/m ² in the order of Comparative Examples 1, 2, and 3) was used instead of the cotton-containing composite nonwoven fabric. A composite sheet was produced in the same manner as in 1 to 3. In Comparative Example 4, a composite sheet was produced in the same manner as in Examples 1 to 3, except that a pulp-containing composite non-woven fabric (trade name: Hydroknit non-woven fabric, manufactured by Kimberly-Clark, USA) was used instead of the cotton-containing composite non-woven fabric. did.

In addition, an air-through nonwoven fabric with a basis weight of 30 g/m ² is used as the top sheet, a breathable polyethylene film with a basis weight of 28 g/m ² is used as the back sheet, and 12 g of fluff pulp, polyacrylic acid-based An absorbent body made of a mixture of 11 g of a super absorbent polymer made of resin was arranged to prepare an absorbent body, and the body was bonded to the skin side of the outer body mainly in the crotch area using a hot melt adhesive. In addition, two 940 decitex urethane thread rubber stretched in the longitudinal direction of spunbond nonwoven fabric are placed on the skin sides of the exterior body at both widthwise ends of the absorbent main body, each stretched to 200%. The gathers were joined to produce a pants-type absorbent article.

The following evaluation tests and sensory evaluations were conducted for each of the pants-type absorbent articles of Examples 1 to 3 and Comparative Examples 1 to 3. The results are shown in Table 1.

<Evaluation of elongation rate in stretching direction>
The elongation rate in the stretching direction was measured using an autograph manufactured by Shimadzu Corporation when stretching within the elastic region in a tensile test with an initial chuck interval (distance between gauge lines) of 150 mm and a tensile speed of 300 mm/min. It was determined as the ratio of the length increased by elongation to the natural length in the non-stretched state when a tensile stress (N/50 mm) was applied.

<Breathability evaluation>
A measurement test piece obtained by cutting out the ventral part from each of the pants-type absorbent articles of Examples 1 to 3 and Comparative Examples 1 to 3 was stretched once by 250% in the stretching direction, and then the stretching was released, and an air permeability test was conducted. The ventilation resistance value R (kPa·s/m) was measured using a machine (trade name: KES-F8, manufactured by Kato Tech Co., Ltd.).

<Sensory evaluation>
Sensory tests were conducted on the elasticity, fit, stuffiness around the abdomen, and feel of the outer body of the absorbent article. Each of the pants-type absorbent articles of Examples 1 to 3 and Comparative Examples 1 to 3 was worn by 20 monitors, and their elasticity (whether it is easy to wear or not), fit, stuffiness around the abdomen, A sensory evaluation was conducted regarding the feel of the exterior body portion (whether it has a softness and texture similar to cloth). Regarding the sensory evaluation, both evaluations were conducted using two options, ``good'' and ``bad,'' and evaluated based on the following criteria.
◎: When 17 to 20 people rated “Good” ○: When 12 to 16 people rated “Good” △: When 5 to 11 people rated “Good” ×: Is there no “Good”? , when there are more than 1 person and less than 4 people

From Table 1, Examples 1 to 3 in which the cotton-containing composite nonwoven fabric was used as the nonwoven fabric for the exterior body were superior in feel to Comparative Examples 1 to 3. In particular, Example 1 was superior to Comparative Examples 1 to 3 in terms of stuffiness.

1 Pants-type absorbent article 10 Exterior body 11 Ventral part 12 Back part 13 Crotch part 14 Cotton-containing composite nonwoven fabric 15 Stretch film 16 Leg gathers 17 Composite sheet 20 Absorbent main body 21 Top sheet 22 Back sheet 23 Absorbent body 24 Three-dimensional gathers 30 Adhesive part

Claims (5)

an absorbent body including a liquid-permeable top sheet, a liquid-impermeable back sheet, and an absorbent body disposed between the top sheet and the back sheet; , an exterior body divided into a crotch area and a back side area, the pants-type absorbent article comprising:
The ventral part and the dorsal part each include a composite sheet,
The composite sheet is
multiple cotton-containing composite nonwoven fabrics;
a stretchable film disposed between the cotton-containing composite nonwoven fabric;
a plurality of adhesive parts spaced apart from each other in the plane direction and integrating the cotton-containing composite nonwoven fabric and the stretchable film;
The cotton-containing composite nonwoven fabric is
non-woven fabric and
a cotton fiber layer laminated on at least one surface of the nonwoven fabric ,
The shape of the adhesive part is such that a rectangle extending in a direction intersecting the direction of expansion and contraction of the composite sheet overlaps a circle whose center coincides with the intersection of diagonals of the rectangle, and the diameter of the circle is the same as the short side of the rectangle. A pants-type absorbent article that is longer than the long side and shorter than the long side . In the exterior body, the basis weight per sheet of the cotton-containing composite nonwoven fabric is 40 g/m ² or more and 60 g/m ² or less, the nonwoven fabric is a spunbond nonwoven fabric, and the spunbond nonwoven fabric and the cotton fiber layer The pants-type absorbent article according to claim 1, wherein the weight composition ratio of the pants-type absorbent article is 40/60% by weight or more and 10/90% by weight or less. The pants-type absorbent article according to claim 1 or 2, wherein the composite sheet is an integrated product including the adhesive portion formed by thermal fusion bonding and/or ultrasonic bonding. The pants-type absorbent article according to any one of claims 1 to 3, wherein the composite sheet has an elongation rate in the stretching direction of 150% or more and 270% or less. The pants-type absorbent article according to any one of claims 1 to 4, further comprising an elastic elastic member disposed extending from the abdominal part to the back part via the crotch part.

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