TWI667017B - Absorbent article - Google Patents

Abstract

An object of the present invention is to provide an absorbent article including a liquid-absorbent layer which is elongated and contracted along the body of a wearer to have good adhesion, and the body fluid excreted to the central portion thereof is less likely to leak and has Desired absorption performance.

The solution to the problem is that the absorbent article (10) has a liquid-absorbing layer (13), a liquid-permeable surface layer (8) located on the skin-opposing surface side of the liquid-absorbing layer (13), and a liquid-absorbing layer (13) The liquid-impermeable back surface layer (9) on the non-skin-facing side, the surface and back layers (8, 9) are extensible, and constitute the sheet member of the surface and back layers (8, 9). At least one of them is flexible. The liquid absorbing layer (13) includes a central elongation means (16) located at a central portion thereof and a side elongation means (18) located at both side portions. The central elongation means (16) is formed by a first slit (15) that intersects the vertical axis (P) and is separated by a predetermined size in the direction of the vertical axis (P). The side elongation means (18) is formed by A plurality of pairs of second narrow edges (13c, 13d) of both sides of the liquid-absorbent layer (13c) extending toward the vertical axis (P) and near the vertical axis (P) in the direction of the horizontal axis (Q). The seam (17) is formed. The second slit (17) is located between the first slits (15) aligned in the longitudinal axis (P) direction, and the inner end of the second slit (17) is located closer to the outer end of the first slit (15). On the side of the vertical axis (P), the liquid absorbing layer (13) can extend at least in the direction of the vertical axis (P).

Description

Absorbent article

The present invention is an absorbent article such as a sanitary napkin, a urine absorbing pad, a pad, and the like.

Absorbent articles having a stretchable liquid-absorptive layer have been conventionally known. For example, Patent Document 1 discloses an absorbent article including a liquid-permeable surface layer on the skin-opposing surface side; a back surface layer on a non-skin-opposing surface side; and an elongation between two sheets. Its liquid-absorbing layer.

[Advanced technical literature] [Patent Literature]

[Patent Document 1] Japanese Patent Laid-Open No. 2009-153736

According to the absorbent article disclosed in Patent Document 1, since the surface layer and the back layer are fixed in a contracted state, the elastic thin The plurality of slits formed of the sheet member and the elastic member and formed in the liquid-absorbent layer have a form extending diagonally from both edges of the liquid-absorbent layer and separated from each other in the longitudinal direction, or two portions from the liquid-absorbent layer. The side edges extend linearly in the width direction and are arranged alternately with each other in the vertical direction. Therefore, the liquid absorbent layer is extended at least in the longitudinal direction by extending the longitudinal direction and opening the slit. Therefore, the entire absorbent article including the liquid-absorbent layer can be stretched in the longitudinal direction during the wearing operation and during the wearing along the body of the wearer.

However, when the slit has the aforementioned form, the central portion of the liquid-absorbent layer between the slits does not extend in the longitudinal direction, and the entire liquid-absorbent layer cannot be sufficiently extended to closely adhere to the body of the wearer. In addition, when the slit has the latter form, the body fluid discharged to the central portion of the liquid absorbing layer may move along the slit toward both side edges, and may easily leak to the outside. In addition, since the top sheet and the back layer are formed of a stretchable sheet and an elastic member that are fixed in a contracted state, the entire absorbent article is in a bent state even in a natural state, and cannot be stretched in a flat state. .

The present invention is an improvement of a conventional absorbent article, and an object of the present invention is to provide an absorbent article having a liquid absorbing layer which is extended and contracted along the wearer's body to have a good fit and excreted to the body. The body fluid in the central part is less likely to leak and has the required absorption performance.

In order to solve the foregoing problem, an object of the present invention is an absorbent article including: a vertical axis and a horizontal axis; a skin-facing surface and a non-skin-facing surface opposite to the skin-facing surface; and a surface located on the skin-facing surface side. Layer; a back layer located on the non-skin-facing side; and a liquid absorbing layer located between the surface and the back layer.

The absorbent article of the present invention is characterized in that: the surface layer and the back layer are composed of a single or a plurality of sheet members, and at least have extensibility toward the longitudinal axis, and among the sheet members constituting the table and the back layer. At least one of them has stretchability in the direction of the longitudinal axis. The liquid absorbing layer includes a central extension means located at a central portion thereof and side extension means located at both side portions. The central extension means is formed by crossing the longitudinal axis. A plurality of first slits arranged in a predetermined size are arranged in the longitudinal axis direction, and the side elongation means is extended from both side edges of the liquid absorbing layer toward the longitudinal axis and horizontally in the vicinity of the longitudinal axis. The second slits are formed by a pair of second slits separated from each other in the axial direction. The second slits are located between the first slits arranged in the longitudinal axis direction. The inner ends of the second slits are positioned more than the first slits. The outer end of the slit is closer to the longitudinal axis side, and the liquid absorbing layer can be extended at least in the longitudinal axis direction.

The disposable absorbent article of the present invention has a central elongation means composed of a plurality of first slits arranged in the central portion of the liquid absorbing layer in the direction of the longitudinal axis, and from both sides of the liquid absorbing layer. A side elongation means in which a pair of second slits extending toward the longitudinal axis and facing each other in the transverse axis direction are aligned in the longitudinal axis direction, so that the liquid absorbing layer can extend at least in the longitudinal axis direction. Therefore, in a state where the absorbent article is attached to clothing such as underwear, the absorbent article can be stretched together with other sheet members, and the absorbent article can be worn along. The person's body deforms in a curved shape. Moreover, since the first slit and the second slit are arranged alternately in the longitudinal axis direction, the body fluid discharged between the first slits in the central portion is unlikely to move to both side portions and leak to the outside. In addition, since a part of the first slit and the second slit intersect in the longitudinal axis direction, the slits can be extended in the longitudinal axis direction even if the opening of each slit is small. In addition, since at least one of the sheets constituting the surface and the back layer has stretchability, the stretchable sheet does not shrink excessively in a natural state, so that the absorbent article can be easily formed into a flat shape.

10‧‧‧ sanitary napkin (absorbent article)

8‧‧‧ surface layer

9‧‧‧ back layer

11‧‧‧ surface sheet

12‧‧‧ back sheet

13‧‧‧Liquid-absorbing layer

13c, 13d ‧‧‧ side edges of the liquid absorbing layer

14‧‧‧Leak-proof sheet

15‧‧‧ 1st slit

16‧‧‧ Central extension means

17‧‧‧ 2nd slit

18‧‧‧Side extension means

19‧‧‧ Both sides of the surface sheet (bent part)

20‧‧‧ side sheet

24‧‧‧Flanks

26‧‧‧ Elastic auxiliary sheet

P‧‧‧Vertical axis

Q‧‧‧ Horizontal axis

R1‧‧‧ The separation dimension of the longitudinal direction of the first slit and the second slit

R2‧‧‧ Separation size of the second slits facing each other in the horizontal axis direction

FIG. 1 is a partially cut-away plan view showing a sanitary napkin as an example of the absorbent article of the present invention as viewed from the surface side.

Fig. 2 is a plan view of a sanitary napkin viewed from the back side.

FIG. 3 is a schematic cross-sectional view taken along the line III-III of FIG. 1.

Fig. 4 is a plan view of a liquid absorbing layer.

Fig. 5 is a plan view showing a state in which the liquid absorbing layer is extended in the longitudinal direction.

FIG. 6 is a view showing a sanitary napkin with an imaginary line and only a solid line showing a wearing state of the liquid-absorbent layer.

FIG. 7 is a view similar to FIG. 5 showing a modified example of the liquid absorbing layer.

FIG. 8 is a plan view showing a state where the liquid-absorbing layer is extended in the first modification.

FIG. 9 is a partially cut-away plan view similar to FIG. 1 in Modification 2. FIG.

Fig. 10 is a schematic sectional view taken along the line X-X in Fig. 9.

As shown in FIGS. 1 to 3, a sanitary napkin 10 shown as an example of the absorbent article of the present invention has a vertical axis P that divides the widthwise dimension into two equal parts, and a lengthwise dimension The horizontal axis Q is divided into two equal parts and includes: the skin-facing surface side and the non-skin-facing surface side on the opposite side; the curved first and second end edges 10a and 10b are protruding; The protruding and curved side edges 10c, 10d of the central part of the place; the liquid-permeable surface sheet 11 on the skin-opposing surface side; and the elastic and liquid-impermeable back sheet 12 on the non-skin-opposing surface side; A liquid-absorbing liquid-absorbing layer 13 between the two sheets 11 and 12; and a leak-proof sheet 14 covering the bottom surface of the liquid-absorbing layer 13. In order to improve the softness of the sanitary napkin 10, a fibrous non-woven intermediate sheet having a high fluffiness may be disposed between the surface sheet 11 and the liquid absorbing layer 13.

In the present invention, in the area where the liquid-absorptive layer 13 exists, a layer composed of a single or a plurality of sheet members located on the skin-opposing surface side is referred to as a surface layer 8, and the non-skin facing the liquid-absorbent structure 13 is opposed A layer composed of a singular or plural sheet member on the front side is referred to as a back layer 9. Therefore, the liquid absorbing layer 13 is interposed between the surface layer 8 and the back surface layer 9. In this embodiment, the surface layer 8 is composed of a surface sheet 11 and an intermediate sheet (not shown), and the back surface layer 9 is composed of a back sheet 12 and a leakage preventing sheet 14. In this embodiment, the pair of side sheets 20 described later is composed of other sheet members different from the back sheet 12, but the side sheet 20 may not be disposed, but a sheet material having the entire size of the sanitary napkin 10 may be used. A back sheet 12 is formed, and a flap portion is formed from the back sheet 12. again In this specification, 100% elongation means that the length from the natural state before the elongation force is doubled, and 50% elongation means that the length from the natural state before the elongation force is 1.5 times. length. Further, pulling the sanitary napkin 10 in the direction of the longitudinal axis P means grasping one end portion and the other end portion of the sanitary napkin 10 and separating the ends toward each other in the direction of the longitudinal axis P. Pulling out in the opposite direction also means fixing one end portion, and pulling the other end portion outward in the direction of the longitudinal axis P to separate it from one end portion.

The liquid-absorbent layer 13 has an elongation means which is arranged over the entire area and can extend at least this length dimension in the direction of the longitudinal axis P. The elongation means includes a central elongation means 16 composed of a plurality of first slits 15 arranged in a line at a central portion thereof in the direction of the longitudinal axis P and extending in the direction of the transverse axis Q; The side portion elongating means 18 constituted by a plurality of second slits 17 arranged in a state in which both sides are separated in a predetermined size in the direction of the longitudinal axis P. The first and second slits 15 and 17 of the liquid-absorbent layer 13 in this embodiment may include slits penetrating through the liquid-absorbent layer 13 and a part of the liquid-absorbent layer 13 remaining on the front or back side. A groove that allows the liquid absorbing layer 13 to be elongated at least in the direction of the longitudinal axis P.

The top sheet 11 is a side facing the back sheet 12 in the leak-proof sheet 14 while both side portions (folded portions) 19 are bent inward and joined. The back sheet 12 extends outward from the front sheet 11 in the direction of the horizontal axis Q, and a pair of side sheets 20 are fixed to the front side. Part of the front sheet 11, the back sheet 12, and the side sheet 20 forms an end flap 22 located on the outer side closer to the longitudinal axis P direction than the liquid absorbing layer 13, and the back sheet 12 and the side sheet 20 form side flaps 24 which are located closer to the outer side of the horizontal axis Q than the liquid absorbing layer 13 and have a pair of flap portions 23 protruding and curved toward the outside near the horizontal axis Q. By arranging the leakage preventing sheet 14 on the bottom surface of the liquid absorbing layer 13, it is possible to prevent leakage of body fluids.

The surface layer 8 and the back layer 9 are composed of singular or plural sheet members (the surface layer 8 is composed of the surface sheet 11 and the intermediate sheet, and the back layer 9 is composed of the back sheet 12 and the leak-proof sheet 14). Elongation in the direction of the longitudinal axis P. That is, all the sheets constituting the surface and back layers 8 and 9 have elasticity or inelastic stretchability. As the non-elastic and stretchable sheet, for example, various conventional fiber nonwovens or plastic films such as spunbond fiber nonwovens, SMS (spunbond-meltblown-spunbond), and fiber nonwovens can be used for gear extension. Processing and cutting are performed to impart predetermined stretchability in the direction of the longitudinal axis P.

In addition, as the elastic and stretchable sheet (that is, the stretch sheet) constituting the table and the back layers 8 and 9, a mass of 10 to 40 g / m ² and more preferably a mass of 15 to 30 g / m ^{2 can be used.} Spunbond nonwoven fabric, hot-air nonwoven fabric, and needle-punched nonwoven fabric composed of elastic fibers (elastic filaments) made of various elastic fiber nonwoven fabrics produced by various conventional manufacturing methods. The elastic fiber is made of a thermoplastic elastomer, rubber, or the like. In particular, when a thermoplastic elastomer is used as a raw material, it can be melt-spun using an extruder in the same manner as a general thermoplastic resin. The obtained fiber is easily heat-welded, and is ideal as a stretchable fiber nonwoven fabric. Examples of the thermoplastic elastomer include SBS (styrene-butadiene-styrene), SIS (styrene-isoprene-styrene), and SEBS (styrene-ethylene-butadiene-styrene). ), Styrene-based elastomers such as SEPS (styrene-ethylene-propylene-styrene), olefin-based elastomers, polyester-based elastomers, polyurethane-based elastomers, and the like. These elastomers can be used singly or in combination of two or more kinds. Further, a core-sheath type or a side-by-side type composite fiber composed of these resins may be used.

Here, the "stretchable sheet" of the present invention refers to a case where the target sheet is stretched with a force of 30mN / 25mm from the natural state toward the longitudinal axis P direction, and the dimension from the natural state to the longitudinal axis P direction If the elongation is 3% or more, the length before the elongation force becomes 1.03 times or more can be obtained.

<Measurement of elongation of stretchable sheet>

For the measurement of the elongation of the stretchable sheet, an Instek universal tensile tester (manufactured by Shimadzu Corporation; precision universal tester AG-1) was used. As a specific measurement method, a sample having a size of 50 mm × 25 mm in the longitudinal axis P direction and the transverse axis Q direction was cut out from a sheet having elongation, and was installed by holding both ends of the sample with a clamp, and 100 mm / A speed of min draws a length of 30 mm in the direction of the longitudinal axis P, and a width of 25 mm per dimension in the direction of the transverse axis Q, and measures the elongation (%) when an elongation force of 30 mN acts on the direction of the longitudinal axis Q.

In addition, at least one of the sheet members constituting the surface and back layers 8 and 9 is a person having elasticity in the direction of the longitudinal axis P. In addition to the elastically stretchable nonwoven fabric described above, the stretchable sheet may be a spunbond nonwoven fabric or an SMS (spunbond-meltblown- Multiple layers such as spunbond) and SM (spunbond-meltblown) can also be formed of a stretchable composite sheet formed by joining the stretchable fiber nonwoven fabric and a non-stretchable fiber nonwoven fabric composed of non-stretchable fibers. . The stretchable composite sheet may be composed of a plurality of layers of stretchable fiber nonwoven fabric arranged between two non-stretchable fiber nonwoven fabrics. The non-stretchable fiber nonwoven fabric may be formed of various conventional fiber nonwoven fabrics such as hot-air fiber nonwoven fabric and hot-rolled fiber nonwoven fabric in addition to spunbond fiber nonwoven fabric. Examples of the constituent fibers of the non-woven fabric used for the non-elastic sheet include fibers made of polyethylene (PE), polypropylene (PP), polyester (PET), and the like.

In the case of using a stretchable composite sheet of a stretchable fiber nonwoven fabric and a non-stretchable fiber nonwoven fabric as each of the sheets 11, 12, and 14, it is also possible to pass the non-stretchable fiber nonwoven fabric through embossing or hot-melt adhesives. The bonding means is bonded to the stretchable fiber nonwoven fabric that has been stretched to a predetermined ratio, and after the two fiber nonwoven fabrics are bonded, the non-stretchable fiber nonwoven fabric is at least partially cut, thereby imparting stretchability to the entire composite sheet. This part of the cut does not extend in series across the entire width direction of the stretchable composite sheet, but is arranged in a dot shape and a slit shape. The non-stretchable fiber nonwoven fabric is cut, and the stretchable fiber nonwoven fabric is not cut. It is better to reduce its stretchability.

Here, the stretchable sheet of the present invention is fixed to another in a state where it is stretched from the dimension of the longitudinal axis P of the natural state by 60% or less, and ideally 40% or less (the state of being stretched 1.4 to 1.6 times). Thin sheet member. In this way, the stretchable sheet is fixed with a relatively low elongation, and the absorbent layer 13 of the sanitary napkin 10 has the required rigidity, Therefore, the stretchable sheet does not shrink and maintains the stretched state. Therefore, the sanitary napkin 10 has a flat shape in a natural state, and when it is pulled in the direction of the longitudinal axis P, it is further extended from the extended state. Therefore, the sanitary napkin 10 can maintain a flat shape. Therefore, when it is fixedly attached to the clothes and is extended with the clothes, it can show a curved shape along the body.

It can be confirmed by the following method that the elastic sheet is fixed at a predetermined elongation. First, when the core wrapping sheet 29 or the side sheet 20 to which the back sheet (plastic film) 12 is bonded is formed of a non-elastic and stretchable sheet, and the back sheet 12 is formed of a stretchable sheet, the physiological A part of the portion where the two sheets were joined by the hot-melt adhesive was cut out with a sanitary napkin 10 as a sample. Next, a cold spray is sprayed on the joint interface of the sample, so that the sheet of the non-elastic and stretchable sheet and the sheet of the stretchable sheet are peeled into a natural state. The length dimension of the two sheets in the natural state was measured, and the length dimension (mm) of the inelastic and stretchable sheet was calculated. The length dimension (mm) of the sheet of the stretchable sheet was calculated. The calculated value was 1.6 or less. Therefore, it was confirmed that the back sheet 12 of the stretchable sheet was fixed in a state where the elongation was 60% or less.

The surface sheet 11 is a liquid-pervious sheet for transmitting body fluid and allowing the liquid-absorbent layer 13 to absorb and hold the surface sheet. A hydrophilic treatment may be performed on the aforementioned constituent fibers or fibrous nonwoven fabric, or a hydrophilic fiber may be used as the constituent. Non-woven fabric of fibers. Moreover, it is not necessary to perform a hydrophilic treatment, but to have a desired liquid permeability by using a porous fibrous nonwoven fabric. Flakes. The leak-proof sheet 14 is formed of a (elastic) thermoplastic film having a hydrophobic property and mainly a thermoplastic polyurethane polymer or the like. The leak-proof sheet 14 may also be formed of a composite sheet composed of the thermoplastic film and a stretchable fiber nonwoven fabric.

The liquid-absorbent layer 13 is a plate shape shaped into a predetermined shape and size, and includes: a semi-rigid and elastically recoverable liquid-absorbent core material 28 which is higher in rigidity than a sheet member; and as an option, in order to improve The liquid-permeable and extensible core material wrapping sheet 29 is formed by covering the liquid-absorbent core material 28 with shape retention and liquid diffusivity. The core-wrapping sheet 29 is similar to other stretchable sheets. It is ideal to use a conventional fiber nonwoven fabric for gear extension processing, cutting, elastic fiber nonwoven fabric, or gear extension including elastic fibers. Processed elastic stretch sheet. The liquid-absorbent core material 28 is formed of a mixture of airlaid fibrous nonwoven fabrics, fluff wood pulp, and superabsorbent polymer particles (SAP). Fluff wood pulp is an artificial cellulose fiber that can be used at the same time or in place of it, for example, chemical pulp, cellulose fiber, concrete, acetate, and the like. The air-laid nonwoven fabric can be, for example, a paper that is thermally fused with synthetic fibers or a binder. The superabsorbent polymer particle system is a three-dimensional mesh structure with a moderately crosslinked water-soluble polymer. It can absorb 30 to 60 times its own weight, but is essentially water-insoluble. For example, starch-based, acrylic-based, Amino acid-based particulate or fibrous polymers.

As the liquid absorbing layer 13 of this embodiment, it is preferable to use a layer formed by laminating a single layer or a plurality of layers of air-laid fibrous nonwoven fabrics without containing superabsorbent polymer particles. By not containing superabsorbent polymer particles, In the manufacturing process, the first and second slits 15 and 17 are easily formed, and there is no possibility that fine particulate superabsorbent polymer particles leak out from the slits 15 and 17. In addition, the formation of the first and second slits 15 and 17 makes it difficult to diffuse body fluids in the direction of the longitudinal axis P, and the superabsorbent polymer particles have a slower absorption rate than absorbing materials such as fluff wood pulp. Therefore, by not containing the superabsorbent polymer particles, it is possible to prevent the diffusion in the direction of the longitudinal axis P and further decrease the absorption rate.

As shown in FIG. 2, on the back side of the sanitary napkin 10, that is, on the outer surface of the back sheet 12, a plurality of first fixed attachment portions 31 for attaching the sanitary napkin 10 to underwear or the like is arranged. The first fixed mounting portions 31 extending linearly from the central portion in the direction of the horizontal axis Q are formed of a pressure-sensitive adhesive, and are arranged apart from each other by a predetermined size in the direction of the vertical axis P. A second fixed mounting portion 32 formed of a pressure-sensitive adhesive is also arranged on the outer surface of the fin portion 23. The first and second fixed mounting portions 31 and 32 are covered with a separator 33 made of a plastic film or a nonwoven fabric. The first and second fixed mounting portions 31 and 32 are preferably those having sufficient fixed mounting strength to the wearer's clothing on a practical level, and specifically have fixed mounting strength of about 2.0 to 4.0N. The first and second fixed mounting portions 31 and 32 do not overlap with the first and second slits 15 and 17 in a planar viewing angle of the sanitary napkin 10, and at least when the liquid-absorbent layer is placed in the direction of the vertical axis P When the existence area of 13 is divided into three equal parts, it is preferable that the area on the side of the first end edge 10a and the area on the side of the second end edge 10b do not overlap each other in a plane viewing angle. In this way, the first and second fixed mounting portions 31 and 32 do not overlap with the first and second slits 15 and 17 in a planar viewing angle, because Accordingly, the openings of the slits 15 and 17 during expansion are not suppressed, and the liquid-absorbent layer 13 can exhibit desired stretchability. Since the first and second fixed mounting portions 31 and 32 have such an arrangement aspect, the required elongation can be ensured on both end sides of the sanitary napkin 10, and the elongation is suppressed compared to such cases, Feeling better.

Although not shown, outer peripheral edges of the sanitary napkin 10 divided by the first and second end edges 10a and 10b and the side edges 10c and 10d are formed with a conventional joining means such as heat embossing. Various sealing methods (e.g., bypass seals) that join various sheet members by various thermal welding methods such as processing and ultrasonic processing. In addition to the outer peripheral edges joined by the sealing portion, the sheet members overlapping each other can use hot-melt adhesives known in this field, but in order not to hinder the overall elasticity of the sanitary napkin 10 It is better to use conventional rubber-based adhesives and hot-melt adhesives based on these mixtures.

As a method for forming the first and second slits 15 and 17 in the liquid-absorptive layer 13, a conventional cutting method can be used. However, when the liquid-absorptive layer 13 contains superabsorbent polymer particles, there is a mixture of thermoplasticity. When a hot-melt material such as fiber is partially cut by a cutting means in a state where only the liquid-absorbent core material 28 or the core material wrapping sheet 29 is used to cover it, the cutting may be performed at the same time or at the same time as the cutting. Before and after, the hot-melt material (when the core-wrapping sheet 29 is formed of thermoplastic fibers, and the core-wrapping sheet 29 is also melted at the same time) is melted, and the hot-melt material is used to prevent a highly absorbent polymer Particles leaked from the cut surface.

As shown in FIGS. 4 and 5, the liquid absorbing layer 13 has: The front and rear edges 13a, 13b are opposed to each other in the P direction, and the side edges 13c, 13d are opposed to each other in the Q direction of the horizontal axis. The central elongation means 16 is constituted by a plurality of first slits 15 which intersect the vertical axis P at the central portion of the liquid absorbing layer 13 and are arranged apart from each other by a predetermined size in the direction of the vertical axis P. . In addition, the side elongation means 18 is constituted by a pair of second slits 17, which are between the first slits 15 and extend from the side edges 10c and 10d toward the longitudinal axis P and Near the vertical axis P, they are separated from each other in the horizontal axis Q direction. The first slit 15 and the second slit 17 partially cross each other in the longitudinal axis P direction. Here, “intersecting” means that the inner end of the second slit 17 extending from the side edges 13c and 13d toward the longitudinal axis P is located closer to the longitudinal axis P than the outer end of the first slit 15, Some of these parts are located opposite to each other in the direction of the vertical axis P. The liquid-absorbent layer 13 is provided with a central elongation means 16 and a side elongation means 18 so that the entire other sheet members and the sanitary napkin 10 are extended in the direction of the longitudinal axis P. The first slit 15 is used to absorb the liquid A plurality of circular openings are formed in the central portion of 13, and the second slits 17 extending inwardly from the side edges 13c and 13d also extend the portion between the openings in the direction of the longitudinal axis P. Therefore, the entire portion is oriented in the longitudinal axis. Elongation in the P direction.

At least one sheet member constituting the sheet members of the surface and back layers 8 and 9 has elasticity, so that the sanitary napkin 10 has the performance of contraction after elongation. Specifically, for example, if at least one of the back sheet 12, the leak-proof sheet 14, and the side sheet 20 constituting the back layer 9 is stretchable, when the entire sanitary napkin 10 is oriented in the direction of the longitudinal axis P Stretchable when stretched. In order to achieve the technical effects of this embodiment As a result, when the sanitary napkin 10 itself is pulled from the natural state in the direction of the longitudinal axis with a force of about 700 mN / 25 mm, it can extend at least 3% in the direction of the longitudinal axis, that is, from the length before the extension force is given. The length is preferably 1.03 times or more. In this case, when the sanitary napkin 10 is extended in the direction of the longitudinal axis P, the liquid-absorbent layer 13 is stretched together with the front and back layers 8 and 9 by the respective extension means 16 and 18, so that the sanitary napkin 10 can be formed. It follows the shape of the body along with the clothing. In addition, the elastic sheet of the sanitary napkin 10 is contracted in accordance with a predetermined elongation of the sheet, and therefore, it can also conform to the movement of the body during wearing.

<Method for measuring elongation of sanitary napkin>

A clamp of a tensile testing machine (such as an Inster-type tensile testing machine) is used to hold both ends of the sanitary napkin 10 at a width of only 10 to 20 mm. For each 25 mm width, it is pulled at a speed of 100 mm / min. Measure the elongation (%) when the elongation force of 700mN that the sanitary napkin does not damage between the clamps is applied to the direction of the longitudinal axis P. Although not shown, in the case where the sanitary napkin 10 has a standing three-dimensional side, the measurement is performed with the three-dimensional side removed.

The elongation of the liquid-absorbent layer 13 in the longitudinal direction P depends on the shape, size, separation size, and the like of the first and second slits 15 and 17. For a 200% elongation, when the dimension W1 in the horizontal axis Q direction of the liquid absorbing layer 13 is about 50 to 120 mm and the dimension L1 in the longitudinal axis P direction is about 150 to 470 mm, the first and second slits 15, 17 Length dimension (in the Q direction of the horizontal axis Size) W2 is preferably about 30 to 70 mm, more preferably about 40 to 60 mm. The separation dimension R1 of the first slit 15 and the second slit 17 adjacent to each other in the longitudinal axis P direction in the longitudinal axis P direction is preferably about 5 to 30 mm, more preferably about 8 to 15 mm, and a separation dimension R2 arranged between a pair of second slits 17 in the Q direction of the horizontal axis is preferably about 5 to 30 mm, and more preferably about 10 to 20 mm.

When the length dimension W2 of the first and second slits 15 and 17 is approximately 30 mm or less, the liquid-absorbent layer 13 cannot be sufficiently extended in the direction of the longitudinal axis P, and the elongation of the entire sanitary napkin 10 may be reduced. . In addition, when the dimension W2 is about 70 mm or more, the tensile strength of the liquid absorbing layer 13 is reduced, and there is a possibility that its shape may collapse during wearing operation or wearing. When the separation dimensions R1 and R2 are each about 5 mm or less, the elongation of the liquid absorbing layer 13 is improved, but the separation dimensions R1 and 2 of the first slit 15 and the second slit 17 are different from each other. When the separation size R2 becomes smaller, the tensile strength of the liquid absorbing layer 13 is lowered, and there is a possibility that a part of the liquid absorbing layer 13 is broken during wearing or wearing operation. In addition, when the separation dimensions R1 and R2 are each about 30 mm or more, although the liquid-absorbent layer 13 has the required tensile strength, the extensibility is reduced, and the entire sanitary napkin 10 cannot be installed in the state of clothing. Fully stretched.

As shown in FIG. 6, in the wearing state of the sanitary napkin 10, since the sanitary napkin 10 is installed on the inner surface of the clothing, each sheet member constituting the sanitary napkin 10 and its liquid absorbing layer 13 are along with the clothing. The wearer's body 39 is elongated in a curved shape. Therefore, it can improve the adhesion to the clothing and the wearer's body 39, and easily conform to the wearer's body 39. Action, leakproof and installation. The first and second slits 15 and 17 constituting the central elongation means 16 and the side elongation means 18 are provided at regular positions of the entire liquid absorbing layer 13 so that the first and second slits 15 and 17 are used during elongation. The formed opening is formed in a regular shape and size. Therefore, compared with the case where the slit is formed in an irregular size and position, the liquid absorbing layer 13 shrinks from the extended state and easily returns to the original state. . In addition, the second slit 17 extends inward from the side edges 10c and 10d, and the entire liquid-absorbing layer 13 becomes accommodating as compared with the case where the second slit 17 extends inward from positions more inward than the side edges 10c and 10d. It extends in the direction of the longitudinal axis P.

For example, if the means for elongating the liquid absorbing layer 13 is formed only by a slit extending inward from the side edges 10c and 10d, the body fluid discharged to the liquid absorbing layer 13 moves along the slit in the horizontal axis Q direction. There is a possibility of leaking to the outside of the liquid-absorbent layer 13, but in this embodiment, the second slit 17 extending inward from the side edges 10c and 10d is located at the center of the liquid-absorbent layer 13 in the direction of the longitudinal axis P Since the first slits 15 arranged in a predetermined size are separated from each other, the body fluid 40 discharged between the first slits 15 in the central portion cannot easily move from the central portion to the outside in the horizontal axis Q direction and leak to the outside. In addition, a part of the first and second slits 15 and 17 intersects in the direction of the longitudinal axis P, so that it can be easily extended in the direction of the longitudinal axis P, and even when one opening is small, the required performance can be achieved. Elongation. That is, according to the arrangement pattern of the first and second slits 15 and 17 of this embodiment, it is possible to coexist the required elongation and body fluid absorption and retention. In addition, at least one of the surface and back layers 8 and 9 is stretchable by at least one of the thin sheet members formed, so that even the entire sanitary napkin 10 can be slightly Shrink to conform to the movements of the body during wearing.

In addition, as another embodiment, all the sheet members constituting the surface and the back layers 8 and 9, that is, the front sheet 11, the back sheet 12, the leak-proof sheet 14, and the side sheet 20 may be made of, for example, an elastic stretchable fiber nonwoven fabric or the like. Formed from a stretchable sheet. In this case, for example, the density of the liquid absorbing layer 13 is about 0.06 to 0.1 g / cm ³ , and the elongation of the liquid absorbing layer 13 is preferably about 100 to 200%. In general, clothing such as panties is designed to extend at least about 50% in the length direction (from the size before the extension force is applied) in order to make the body fit to the wearer, etc. The perineal part is made in a curved shape. In order to attach the sanitary napkin 10 to clothing and extend about 50% therewith, each sheet member and the liquid absorbing layer 13 constituting the sanitary napkin 10 are sealed with each other on the outer peripheral edge, a hot-melt adhesive, etc. If the elongation of the sheet material and the material of the liquid-absorptive layer 13 is reduced when they are bonded to each other, the elongation ratio of about 50% to the clothing makes it difficult to maintain the elongation of the components constituting the sanitary napkin 10 / The shape of the liquid-absorbent layer 13 after the shrinkage is 100% extensible, and it can be said that the shape can be easily maintained even if the expansion / contraction is repeated.

<Method for measuring elongation of liquid absorbing layer>

As a method for measuring the elongation of the liquid absorbing layer 13, first, a cold spray is sprayed on the joint interface of the liquid absorbing layer 13, and the liquid absorbing layer 13 is taken out from the sanitary napkin 10 as a sample. Hold one end of the sample in one of the clamps of a tensile tester (for example, an Inster type tensile tester), and clamp the other end Hold the other jig at a pulling speed of 50 mm / min, and pull until the liquid-absorbent core material 28 of the liquid-absorbent layer 13 is visually broken. Calculate the length of the longitudinal axis P of the liquid-absorbent layer 13 when the absorbent core material 28 is broken ÷ the length of the longitudinal axis P of the absorbent layer 13 when taken out of the sanitary napkin 10 (initial stage). For example, the calculated value is 2.5. In this case, the elongation is considered to be 150%.

In this way, when the surface sheet 11 is formed of a liquid-permeable stretchable fibrous nonwoven fabric, the skin feels good, and all the sheet members that come into contact with the skin of the wearer are the surface sheet 11 and the back surface constituting the surface layer 8 Both the sheet 12 and the side sheet 20 are formed of a stretchable fiber nonwoven fabric. As a result, the sanitary napkins as a whole have the skin-like feel and softness of undergarments, which improves the wearing feeling. In addition, the side flaps 24 are formed by the stretchable sheet, the back sheets 11, 12 and the stretchable side sheet 20, and therefore, the side flaps are formed more than the case where the side flaps 24 are formed only by the front and back sheets 11, 12. The strength of the 24 is improved and the stretchability is improved. When the side flap 24 is pulled toward the horizontal axis Q while being fixed to the clothing through the second fixed mounting portion 32 located on the back side of the flap portion 23, it can be stably fixed. installation.

<Change example 1>

As shown in FIG. 7 and FIG. 8, in one of the modified examples of the liquid absorbing layer 13, the first and second slits 15 and 17 are wavy, and the liquid absorbing layer 13 is extended in the direction of the longitudinal axis P together with the clothing. The shape of the opening formed by the first and second slits 15 and 17 is also wavy. In the case where the first and second slits are linear, they are bent to fit the body. The linearly deformed or curved portion may be slightly deformed or hardened to give the wearer an uncomfortable feeling. However, as in this modified example, it is wavy, that is, when it is continuously curved, it runs along the slit. Since the shape is curved, this discomfort can be suppressed.

<Change example 2>

As shown in FIGS. 9 and 10, in this modified example, between the surface sheet 11 and the side sheet 20, between the first and second end edges 10 a and 10 b, there are disposed extending from the outer edge of the bending portion 19 to One of the inner edges of the flap portion 23 is a pair of elastic auxiliary sheets 26. The elastic auxiliary sheet 26 is located outside the two side portions of the liquid absorbing layer 13 and imparts stretchability to its arrangement area, thereby assisting the semi-rigid liquid absorbing layer 13 having a higher rigidity than the sheet member to extend in a curved shape together with clothing such as underwear. Action. In this way, the elastic auxiliary sheet 26 and the elastic sheet constituting any of the sheet members of the surface and back layers 8 and 9 are stretched and contracted, so that the sanitary napkin 10 can easily conform to the wearer's body during wearing. action.

In addition, in the case where the constituent members constituting the sanitary napkin 10 are not specifically described, in addition to the materials described in this specification, various conventional methods commonly used in this field can be adopted without limitation. material. In addition, the terms "first" and "second" used in this specification and the scope of patent application are only used to distinguish the same elements, locations, and the like. Further, in order to improve the diffusivity of the body fluid from the front side to the back side of the sanitary napkin 10, a compression groove may be formed in a predetermined pattern.

The above-mentioned disclosure about the present invention can be at least The summary is as follows.

An absorbent article includes: a vertical axis and a horizontal axis; a skin-facing surface and a non-skin-facing surface on the opposite side thereof; a surface layer located on the skin-facing surface side; and a surface layer located on the non-skin-facing surface side A back layer; and a liquid absorbing layer between the above-mentioned table and the back layer, characterized in that the above-mentioned surface layer and the above-mentioned back layer are composed of a singular or plural sheet members and have at least elongation toward the longitudinal axis, At least one of the sheet member of the table and the back layer has stretchability in the direction of the longitudinal axis, and the liquid absorbing layer includes a central extension means located at a central portion thereof and a side extension means located at both side portions. The central elongation means is formed by a plurality of first slits which intersect the longitudinal axis and are arranged apart from each other by a predetermined size in the longitudinal axis direction. The side elongation means is formed from both sides of the liquid-absorbent layer toward the longitudinal direction. A pair of second slits extending along the axis and separated from each other in the horizontal axis direction near the vertical axis, the second slits being located between the first slits arranged in the vertical axis direction, The inner end of the second slit is located closer to the longitudinal axis side than the outer end of the first slit, and the liquid absorbing layer is at least extendable in the longitudinal axis direction.

The invention disclosed in the above paragraphs may include at least the following embodiments.

(1) When pulled from the natural state in the direction of the longitudinal axis with a force of about 700 mN / 25 mm, it can be extended at least 3% in the direction of the longitudinal axis.

(2) The surface layer is a liquid-permeable surface sheet, the back layer is a liquid-impermeable back sheet, and the At least one of them is formed of a stretchable fiber nonwoven fabric.

(3) The separation size of the first slit and the second slit in the longitudinal axis direction is approximately 5.0 to 30.0 mm, and the separation size of the pair of the second slits facing each other in the horizontal axis direction is approximately 5.0 to 30.0mm.

(4) The back surface layer includes a leak-proof sheet disposed on a bottom surface of the liquid absorbing layer and having liquid impermeability and elasticity.

(5) A stretchable side sheet is disposed extending from the two side portions of the liquid absorbing layer to the outside in the horizontal axis direction.

(6) A pair of elastic auxiliary sheets extending in the longitudinal axis direction are disposed on the side flaps formed by the front sheet, the back sheet, and the side sheet outside the both edges of the liquid absorbing layer.

Claims (7)

An absorbent article includes: a vertical axis and a horizontal axis; a skin-facing surface and a non-skin-facing surface on the opposite side; a surface layer on the skin-facing surface side; and a back surface on the non-skin-facing surface side And a liquid absorbing layer between the above-mentioned table and the back layer, wherein the surface layer and the back layer are composed of a singular or a plurality of sheet members, and have elongation at least toward the longitudinal axis, constituting the aforementioned At least one of the sheet members of the table and back layers is stretchable in the direction of the longitudinal axis, and the liquid absorbing layer includes a central part in the direction of the transverse axis and separated in the direction of the longitudinal axis. A plurality of central elongation means arranged at a predetermined size; and a side elongation means located on both sides and arranged alternately with the central elongation means in the direction of the longitudinal axis, the central elongation means intersecting the longitudinal axis only It is formed by a first slit, and the means for extending the side portion is formed by extending from both side edges of the liquid-absorbent layer toward the longitudinal axis and dividing each other in the direction of the transverse axis in the vicinity of the longitudinal axis. The second slits are formed by a pair of second slits. The second slits are located between the first slits arranged in the longitudinal axis direction. The inner end of the second slits is located more than the outer ends of the first slits. Closer to the longitudinal axis side, the liquid absorbing layer can extend at least in the longitudinal axis direction. For example, if the absorbent article according to item 1 of the patent application scope is drawn from the natural state in the direction of the longitudinal axis with a force of about 700mN / 25mm, it can be extended at least 3% in the direction of the longitudinal axis. For example, if the absorbent article according to item 1 or 2 of the patent application scope, the surface layer is a liquid-permeable surface sheet, the back layer is a liquid-impermeable back sheet, and at least one of the watch and the back sheet is used. One side is formed of a stretchable fiber nonwoven fabric. For example, if the absorbent article according to item 1 or 2 of the patent application scope, the separation dimension between the first slit and the second slit in the longitudinal axis direction is 5.0 to 30.0 mm, and The separation size of the second slit is 5.0 to 30.0 mm. For example, in the absorbent article according to the first or second aspect of the patent application, the back layer is a leak-proof sheet that is disposed on the bottom surface of the liquid-absorptive layer and has liquid impermeability and elasticity. For example, in the absorbent article according to the third aspect of the patent application, a stretchable side sheet extending from the two side portions of the liquid absorbing layer to an outer side in the horizontal axis direction is further disposed. For example, in the absorbent article according to item 6 of the patent application, the side flaps formed by the surface sheet, the back sheet, and the side sheet outside the side edges of the liquid absorbing layer are disposed toward the longitudinal axis. A pair of elastic auxiliary sheets extending in the direction.