JP5075615B2 - Absorbent articles - Google Patents

Description

  The present invention relates to an absorbent article such as a sanitary napkin, a panty liner (cage sheet), and an incontinence pad.

One way of preventing leakage in an absorbent article such as a sanitary napkin is to create as little gap as possible between the skin contact surface of the absorbent article and the skin of the wearer. In order not to generate a gap, it is effective that the absorbent article is deformed following the movement of the wearer, and for this reason, an absorbent article that is extensible is known (for example, see Patent Document 1). ).
Further, a thin absorbent sheet having a large absorption capacity that can be used as an absorbent body for absorbent articles such as sanitary napkins has been proposed (see, for example, Patent Document 2).

Japanese National Patent Publication No. 10-508225 JP-A-8-246395

The absorbent article described in Patent Document 1 is assumed to expand and contract together with the underwear in a state of being attached to the underwear, but the absorbent performance is reduced when the absorbent article is extended.
Further, if the absorbent sheet described in Patent Document 2 has the same thickness, the absorbent sheet tends to have higher rigidity than an absorbent body obtained by sucking and depositing pulverized pulp supplied in a scattered state. When used in a deformable absorbent article, the part located in the center in the width direction of the article is buckled in the longitudinal direction, and the creases, wrinkles, twists, etc. caused thereby are hard on the wearer. There are inconveniences such as a strange feeling and a stiff feeling.

  Accordingly, an object of the present invention is to provide an absorbent article that is excellent in fit, followability to the movement of the wearer, leakproofness, and wearing feeling.

  The present invention is an absorbent article comprising a liquid-permeable top sheet, a back sheet and a vertically long absorbent interposed between the two sheets, the absorbent comprising an absorbent sheet, , Having a notch extending inward in the width direction from each side edge in the longitudinal direction, and having a liquid holding capacity less than that of the absorbent sheet on the surface of the absorbent sheet on the surface sheet side. The object is achieved by providing an absorbent article in which an extensible sheet is arranged.

  The absorptive article of the present invention is excellent in fit nature, followability to a wearer's movement, leakproofness, and wearing feeling.

Hereinafter, the present invention will be described based on a preferred embodiment thereof with reference to the drawings.
A sanitary napkin 1 (hereinafter, also simply referred to as a napkin 1) according to the present embodiment includes a liquid-permeable surface sheet 2 and a liquid-impermeable (concept including impermeable) as shown in FIGS. A back sheet 3 and a vertically long absorbent body 4 interposed between the two sheets 2 and 3 are provided. The longitudinal direction of the absorbent body 4 in the napkin 1 coincides with the longitudinal direction of the wearer when the napkin 1 is worn, and also coincides with the longitudinal direction of the napkin 1.
The top sheet 2 and the back sheet 3 are joined to each other at the peripheral edge 11 of the napkin 1 at a portion extending from the peripheral edge of the absorbent body 4. The surface (non-skin contact surface) on the back sheet 3 side of the napkin 1 is provided with an adhesive portion (not shown) for fixing to underwear such as shorts.

The absorbent body 4 in the napkin 1 includes an absorbent sheet 41, and the absorbent sheet 41 has cuts 42 extending inward in the width direction from both side edges in the longitudinal direction, as shown in FIG. Yes. The absorbent sheet 41 has substantially no extensibility when there is no notch 42, but the both sides S are formed by forming the notches 42 on both sides S, S in the longitudinal direction. , S can be extended in the longitudinal direction. More specifically, both side portions S, S expand when the cut 42 is opened, and contract when the extended cut 42 is closed or opened.
In the present embodiment, a plurality of cuts 42 are intermittently formed at predetermined intervals on both side portions of the absorbent sheet 41 in the longitudinal direction. Further, the cuts 42 in the present embodiment have a slit shape and are formed substantially parallel to the width direction of the absorber 4.

The number and interval of notches formed in the absorbent sheet 41 can be appropriately determined according to the size of the napkin 1 (absorbent article), the size of the absorbent body 4 and the like.
In the absorbent sheet 41, an interval L1 (see FIG. 3) between the adjacent cuts 42 and 42 in the longitudinal direction of the absorbent body 4 is preferably 1 to 7 cm, and more preferably 1.5 to 5 cm.
Further, in the absorbent sheet 41, the number of cuts on one side in the longitudinal direction (three shown in FIG. 3) is preferably 2 to 50, and more preferably 3 to 30. If a more specific example is shown, when the full length L (refer FIG. 3) of the absorber 4 is 8-20 cm, the number of the notches of one side of the absorption sheet 41 will be 2-20, especially about 3-15. preferable.

  The cut depth L2 (see FIG. 3) of the absorbent sheet 41 is preferably 10 to 40% of the width W (see FIG. 3) of the absorbent body 4 at each cut-off portion, and more preferably. 15-30%. In addition, it is preferable that L2 is 1-4 cm, More preferably, it is 1.2-3 cm.

In the napkin 1 of the present embodiment, the non-woven stretchable sheet 5 having a smaller liquid holding capacity than the absorbent sheet 41 is disposed on the surface of the absorbent sheet 41 on the surface sheet 2 side.
The extensible sheet 5 has substantially the same shape as the non-extendable absorbent sheet 41, and has at least extensibility in the same direction as the longitudinal direction of the absorbent sheet 41 (absorbent body 4).

The extensible sheet 5 can draw the liquid smoothly from the top sheet 2 and temporarily hold the liquid, and when the absorbent sheet 41 exists in the lower layer, the liquid is quickly transmitted to the absorbent sheet 41. Is possible. This is due to the magnitude relationship between the surface sheet 2, the extensible sheet 5, and the absorbent sheet 41.
On the other hand, in the state where the cuts 42 of the absorbent sheet 41 are opened, the liquid temporarily held by the extensible sheet quickly moves to the lower layer (absorbent sheet) on the surface facing the absorbent sheet 41. On the other hand, in the portion facing the open cut 42, the liquid is temporarily held by the extensible sheet. However, when the liquid moves in the portion facing the absorbent sheet 41 (the amount of liquid in that portion becomes almost zero, on the other side of the cut 42, The liquid is redistributed (that is, horizontally diffused) due to a difference in the amount of liquid in the extensible sheet 5 (to retain the liquid still), and the liquid is sequentially transferred to the opposite side of the absorbent sheet, so that the absorbed liquid is absorbed. The cut-out portion 42 of the sheet 41 is avoided and the process proceeds to the absorbent sheet 41. This is due to the temporary retention of liquid and the liquid transferability (both horizontal and vertical directions) of the extensible sheet 5.
These properties of the extensible sheet 5 are obtained by the following sheet characteristics.
1) The entire sheet has hydrophilicity. As will be described later, since the fibers are aggregated so that the stretchability can be expressed, the stretchable sheet 5 has the following characteristics (compared to the absorbent sheet). 2) Low bulk density, 3) Low liquid holding capacity, 4) Low Krem water absorption.

1) Hydrophilicity is achieved by forming a sheet containing a large amount of essentially hydrophilic fibers such as rayon, pulp, and cotton, or the like by a hydrophilic treatment known to those skilled in the art. In the hydrophilization treatment, hydrophobic fibers may be hydrophilized in advance, or may be hydrophilized by a hydrophilization treatment after forming the sheet.

2) The bulk density is a weight (g / cm ³ ) per unit volume of the material and can be calculated as follows. Material weight: Weight measured with a METTLER electronic balance or the like with three or more digits after the decimal point, volume; material cut out with a width of 5 cm and a length of 10 cm to obtain a test piece. The thickness is measured with a peacock thickness gauge or the like, and the load thickness of 2.5 g / cm ² is measured and converted into cm, and the width × length × thickness (cm ³ ) is defined as the volume. By forming the extensible sheet 5 with a nonwoven fabric to be described later, it can be formed mainly in a dry process (method of depositing fibers in an air stream) and can have a low density, while the absorbent sheet 41 is wet (as described later). The latter bulk density can be increased by selecting a method in which fibers are deposited and combined under the influence of water or water. Specifically, the bulk density of the extensible sheet 5 is preferably 0.1 g / cm ³ or less, more preferably 0.07 g / cm ³ or less, and 0.015 to 0.065 g / cm ^3. Most preferably, it is in the range.
On the other hand, the bulk density of the absorbent sheet 41 is 0.08 g / cm ³ or more, preferably higher than the extensible sheet 5, more preferably 0.1 g / cm ³ or more, and 0 Most preferably, the density is higher than 125 g / cm ³ .

3) It is also preferable that the liquid holding capacity of the extensible sheet 5 is smaller than the liquid holding capacity of the absorbent sheet 41 in order to realize horizontal diffusion of the liquid in the extensible sheet and effective transfer to the absorbent sheet. If the capacity of the extensible sheet 5 is larger than that of the absorbent sheet 41, the absorbed body fluid is stored in the extensible sheet 5, causing direct liquid return and leakage, and even when the cut portion 42 is open, Since the body fluid is stably stored in the extensible sheet on the upper part, efficient liquid movement to the absorbent sheet is hindered.
Therefore, in the present invention, as the extensible sheet 5, a liquid holding capacity smaller than that of the absorbent sheet 4 is used.
The liquid holding capacity of the extensible sheet is 60% or less, particularly 2 to 45% of the liquid holding capacity of the absorbent sheet. As described above, the liquid obtained by the extensible sheet 5 can be quickly transferred to the lower absorbent sheet 41. This is preferable because it can be transmitted and does not reverse.

The liquid holding capacity of the extensible sheet and the absorbent sheet is measured as a liquid holding amount per unit weight as follows.
(Measurement method of liquid holding amount per unit weight)
The extensible sheet 5 and the absorbent sheet 41 are each taken out from the napkin (absorbent article). Both may be cut into a suitable size to form a test piece. For example, the test piece may be cut into a width of 50 mm and a length of 150 mm. As will be described later, it is preferable that the test piece is of a size that can be centrifuged without being overlapped, such as being folded in two.
A non-woven fabric or nylon mesh or the like is used to create a bag of a size that allows the test piece to be expanded and the bag weight is measured in advance. Let this weight be W0. Each test piece is weighed in advance. Let this weight be W1. The test piece is spread in the bag and immersed in a vat containing an excess amount of physiological saline for 1 minute. Immediately after this, the bag (with the test piece) is taken out, fixed to the inner periphery of the basket of Kokusan Co., Ltd. H-130C, centrifuged at 2000 rpm for 10 minutes, and then the bag. The test piece is taken out and the weight is measured. Let this weight be W2.
From the above measurement results, the amount of liquid retained per unit weight is
Liquid holding amount (g / g) = (W2-W1-W0) / W1
Can be calculated.

The liquid holding amount of the extensible sheet 5 is preferably 5 g / g or less, more preferably 3 g / g or less, and most preferably in the range of 0.4 to 2.4 g / g.
On the other hand, the liquid holding amount of the absorbent sheet 41 is preferably 7 g / g or more, more preferably 10 g / g or less, and most preferably in the range of 11 to 28 g / g.

4) The Krem water absorbency correlates with the mobility of the liquid between the materials, and the liquid tends to move to a material having a high Klem water absorbency. Therefore, the extremity sheet 5 needs to have a high water absorption rate so that the liquid can be pulled out from the top sheet 2 and low enough to smoothly move the liquid to the absorbent sheet 41.
(Measurement method of Krem absorbency)
JIS P8141 is applied mutatis mutandis as follows.
Each of the extensible sheet 5 and the absorbent sheet 41 is taken out and cut into a width of 15 mm and a length that can be taken according to the direction of the product to obtain a test piece.
In the case where the absorbent sheet 41 is configured by overlapping a plurality of sheets, it is preferable to measure the Klemm water absorbency individually for all the sheets and use the material having the highest water absorbency as the representative value.
When cutting out the test piece, a cutting method that may crush the sheet, such as a push-off cutter, is not preferable because it has a high possibility of affecting the results. In particular, when cutting out with a width of 12 mm (when the longitudinal direction of the test piece is cut out), the cut surface is cut out using a knife, cutter, razor or the like.
Hereinafter, a test piece is set on a jig specified in JIS P8141, and the water absorption after 1 minute is measured using physiological saline as a test solution. In order to facilitate the determination of the suction height, the test solution may be appropriately colored with a dye such as Blue No. 1 or methylene blue.
Normally, the water absorption of all components can be measured by the size (length) of the test piece. If the suction height after 1 minute exceeds the total length of the test piece, two test pieces are connected vertically. It may be remeasured together. Specifically, 3 mm of test pieces are overlapped at the seam, and measurement is performed by lightly fastening with a cellophane tape from one side. At this time, the cellophane tape width is set to the width of the test piece and the same length is set to 20 mm so that the influence of sticking is minimized.
The above measurement is performed three times, and the average value is defined as the Klem water absorption.

The extensible sheet 5 has a Klem water absorption of preferably 15 to 60 mm, and more preferably 20 to 55 mm.
On the other hand, the Klem water absorption of the absorbent sheet 41 is preferably 45 mm or more, more preferably 60 mm, and most preferably 65 to 120 mm.

  Satisfying all the above requirements 1) to 4) is the most preferable form for transferring body fluid to an absorbent sheet quickly, satisfying deformability and absorbability, and obtaining an absorbent article with a smooth surface. However, the requirements 1), 2), and 4) are important for achieving satisfactory absorption.

Further, the extensible sheet 5 can be easily extended in the same direction as the longitudinal direction of the absorbent sheet 41 so as not to prevent the absorption sheet 41 from being elongated and the deformation of the absorbent sheet 41 due to the opening of the cuts 42. Is preferred.
For example, the stretchable sheet 5 preferably has a stretch rate of 10% or more at a load of 50 gf when stretched in the same direction as the longitudinal direction of the absorbent sheet 41 (absorbent body 4), and is 15 to 40%. Is more preferable.

In addition, the extensible sheet 5 helps to restore the deformed absorbent sheet to its original state by opening the notch, and enhances the followability to the body movement of the napkin 1 to improve the fit and leakage prevention. From the viewpoint of obtaining the same followability (stretchability) with respect to repeated deformation, it is preferable to have elastic stretchability.
For example, the extensible sheet 5 preferably has a permanent distortion within 7% after being stretched to an elongation rate of 30% in the same direction as the longitudinal direction of the absorbent sheet 41 (absorber 4). More preferably.

Since a general material known to those skilled in the art does not have stretchability at a low load of about 50 g, a method of measuring the stretch rate by the following method can be easily used.
(Preparation of specimen)
A direction to be measured is a longitudinal direction, a direction orthogonal to the longitudinal direction is a width direction, and the test piece is cut to have a longitudinal direction of 12 cm × a width of 1 cm. For example, when measuring in the same direction as the longitudinal direction of the absorber, the length is 12 cm × 1 cm in the width direction, and when measuring in the same width direction, the length is 1 cm × 12 cm in the width direction.
(Measurement of low load elongation)
Measuring machine: Tensilon tensile tester RTM100 manufactured by Orientec Co., Ltd. was used.
Measurement conditions: Distance between chucks: 10 cm
Pulling speed: 100 mm / min Measurement is performed in the pulling direction, and the apparatus is stopped when the load is pulled to 50 g.
Read the change in the length of the test piece in the actual measurement of the chart or chuck distance, and calculate the expansion ratio as follows.
Elongation rate (%) = length variation (mm) / original specimen length (mm) × 100

In the measurement of the permanent strain, it is most convenient to measure the recovery process of the test piece following the measurement of the stretch ratio.
Immediately after measuring the stretch ratio, the Tensilon is restored to the original distance between chucks. Measurement speed at this time is 100 mm / min.
From the chart, read the point where the tensile load is 0 g. In the case of a material that expands and contracts completely, 0 g becomes the point of 0 mm extension, and in the case of an incompletely stretchable material, it becomes 0 g on the front side (position where the elongation of several mm to several cm is left). The elongation rate at the 0 g position is defined as permanent distortion. That is,
Permanent strain (%) = 0 g Elongation at restoration (mm) / Original specimen length (mm) × 100

As the nonwoven fabric used as the extensible sheet, various known extensible nonwoven fabrics conventionally used for this type of article can be used. From the viewpoint of ensuring good transferability of the liquid, the extensible sheet is preferably made of the following non-woven fabric A or non-woven fabric B.
Non-woven fabric A: Spunbond-based non-woven fabric containing elastic fibers Non-woven fabric B: It is preferably made of a non-woven fabric containing crimped fibers.

[Nonwoven fabric A]
As the elastic fiber in the non-woven fabric A, a fiber made of a thermoplastic elastomer, rubber or the like can be used. Examples of the thermoplastic elastomer include styrene elastomers such as SBS, SIS, SEBS, and SEPS, olefin elastomers, polyester elastomers, and polyurethane elastomers. The elastic fibers made of these resins can be used singly or in combination of two or more. Further, core-sheath type or side-by-side type composite fibers made of these resins can also be used.

The nonwoven fabric A is preferably made of 100% elastic fiber when spunbonded as described above.
On the other hand, an elastic spunbond layer and other nonwoven fabric layers can coexist. Examples of other fibers that coexist with the elastic fiber include PET, PP, PE, nylon, and composite fibers thereof. Examples of the nonwoven fabric include air-through and heat roll nonwoven fabric as well as spunbond.
The nonwoven fabric layer is bonded to the elastic spunbond layer so as to be stretchable by embossing, hot melt adhesive, and a composite thereof. In order to bond the layers in a stretchable manner, the nonwoven fabric layer is bonded under the elastic spunbond layer stretched state, or the nonwoven fabrics are bonded together, and then partially cut by various methods to develop the stretchability. Partial cutting means that the cutting is not continuous in the width direction of the sheet, but is made in a discrete pattern of dots or slits. More preferably, it means that the cutting is selectively performed mainly on the non-stretchable nonwoven fabric layer (as viewed in the thickness direction), and does not completely cut the elastic spunbond layer. The non-stretchable nonwoven fabric layer may be bonded to both surfaces of the elastic spunbond layer.

  The spunbond nonwoven fabric in the nonwoven fabric A includes a single layer spunbond nonwoven fabric (S) and a multilayer nonwoven fabric having a layer composed of a spunbond nonwoven fabric and a layer composed of another nonwoven fabric. The multilayer nonwoven fabric has one or more layers made of melt blown nonwoven fabric (M) between two layers made of spunbond nonwoven fabric (S) (SMS, SMMS), and spunbond nonwoven fabric (S) with melt blown nonwoven fabric (M ) And the like (SM).

[Nonwoven fabric B]
As the crimped fiber in the nonwoven fabric B, a fiber obtained by mechanically imparting secondary or three-dimensional crimps to the fiber can be used, including a latent crimpable fiber that exhibits a spiral crimp by heat treatment. It is preferable. The latent crimpable fiber that has developed crimps is in a coiled crimped state. The latent crimpable fiber includes, for example, an eccentric core-sheath type composite fiber or a side-by-side type composite fiber containing two types of thermoplastic polymer materials having different shrinkage rates as components. Examples thereof include those described in JP-A-9-296325 and Japanese Patent No. 2759331. As an example of two types of thermoplastic polymer materials having different shrinkage rates, for example, a combination of an ethylene-propylene random copolymer (EP) and polypropylene (PP) is preferably exemplified.
The nonwoven fabric B preferably contains crimped fibers, particularly latent crimpable fibers, in an amount of 25% by mass or more, more preferably 30 to 100% by mass, and more preferably 40 to 90% by mass in the total amount of the constituent fibers. This is true.
Other fibers that coexist with the latent crimpable fibers include polyolefins such as polyethylene (PE) and polypropylene (PP), fibers made of polyester (PET and PBT), polyamide, etc., and composite fibers thereof, rayon, Examples thereof include hydrophilic fibers such as pulp and cotton.

From the viewpoint of the production method, as the nonwoven fabric B, an air-through nonwoven fabric in which heat-bonding points of fibers are formed by a air-through method on a fiber web obtained by a card method or an airlaid method, a heat roll on a fiber web obtained by a card method Various nonwoven fabrics such as a heat roll nonwoven fabric, a heat embossed nonwoven fabric, a spunlace nonwoven fabric, and a needle punched nonwoven fabric in which heat-bonding points of fibers are formed by the method can be used.
In order to obtain a stretch nonwoven fabric with a low bulk density by applying latent crimped fibers, the fiber web deposited with a predetermined fiber composition is partially embossed with dots and then the air-through method The method of heating and heating to develop crimps is most preferable.

  In FIG. 4, the example of the preferable embossing pattern of the embossing given to the nonwoven fabric which comprises the extensible sheet | seat 5 was shown. 4A to 4C are emboss patterns preferable for the spunbond nonwoven fabric constituting the nonwoven fabric A, and FIG. 4D is a preferred emboss pattern for the nonwoven fabric constituting the nonwoven fabric B. FIG.

  The extensible sheet 5 is preferably hydrophilic including the non-woven fabric A or B. A hydrophilic non-woven fabric is a non-woven fabric made of hydrophilic fibers that are hydrophilic by subjecting them to hydrophilicity in the state of fibers or non-woven fabrics, or are made of hydrophilic fibers that are hydrophilic even if they are not hydrophilized. May be.

In the napkin 1 of the present embodiment, the longitudinal direction of the absorbent sheet 41 is between the extensible sheet 5 and the absorbent sheet 41 and between the absorbent sheet 41 and the back sheet 3 at the center M in the width direction of the absorbent sheet 41. Are joined together. Moreover, in each of the longitudinal side portions S, S of the absorbent sheet 41, there is no joint between the extensible sheet 5 and the absorbent sheet 41 and between the absorbent sheet 41 and the back sheet 3 across the cut. It is joined to. Specifically, the absorbent sheet 41 is joined to the extensible sheet 5 and the back sheet 3 at a part indicated by reference numeral 43 and a part indicated by reference numeral 44 in FIG. 3, respectively.
Joining between the extensible sheet 5 and the absorbent sheet 41 and between the absorbent sheet 41 and the back sheet 3 is preferably joined by an adhesive, respectively, but instead of the adhesive, any other optional heat seal or the like A joining method can also be used. Further, when joining with an adhesive, solid coating with a slot coater or the like may be used, but pattern coating is preferred. Preferable examples of the pattern coating application include spiral patterns, dot patterns, stripe patterns (striped patterns), lattice patterns, checkered patterns, and the like. Furthermore, in order to improve the anti-shrinking property, the amount between the sheet-like absorbent bodies 41 and 42 is changed to a sheet-like absorbent body at only one place in the center of the excretion part of the napkin (in this embodiment, the position of the line II-II in FIG. It can be fixed when there is no break.

As shown in FIG. 5, the napkin 1 of the present embodiment is used by being fixed to the inner surface side (skin facing surface side) of the crotch part of an underwear 6 (hereinafter also simply referred to as shorts) such as shorts.
When the napkin 1 is attached, the napkin 1 is fixed to the shorts and then the shorts are pulled up. When the shorts are pulled up, first, the cross-sectional shape of the napkin 1 in the width direction is directed upward with respect to the napkin 1. Thus, a force for deforming into a convex shape is mainly applied, and further, a force for deforming the cross-sectional shape of the napkin 1 in the longitudinal direction into a concave shape is applied.

In the napkin 1 of the present embodiment, both side portions S, S in the longitudinal direction of the absorbent sheet 41 (absorbent body 4) extend flexibly when the cuts 42 of the absorbent sheet 41 are opened. When a force that deforms the longitudinal cross-sectional shape upward is applied, both side portions S, S in the longitudinal direction of the absorbent body 4 are smoothly extended, and the absorbent body 4 is The cross section in the direction has a shape gently curved concavely on the skin contact surface side, and the cross section in the width direction also has a shape gently curved convexly on the skin contact surface side.
Therefore, the buckling of the absorbent body, in particular, the portion located at the center in the width direction of the napkin (absorbent article) is prevented from buckling in the longitudinal direction, and there is a sense of incongruity due to creases, wrinkles, twists, etc. caused by buckling of the absorbent body And discomfort can be prevented.
Moreover, since the extensible sheet 5 is disposed on the surface of the absorbent sheet 41 on the surface sheet 2 side, even if the cut portion 42 is opened entirely or partially when both side portions of the absorbent sheet 41 extend, The extensible sheet 5 smoothly transfers the liquid on the cuts 42 to other parts of the absorbent sheet 41. Therefore, inconvenience such as liquid leakage does not occur through the open cut 42.

  Moreover, if the extensible sheet 5 has elastic stretchability in the longitudinal direction, stretchability is imparted to both side portions of the napkin 1, and follow-up deformability with respect to body movement is improved, so that the body shape of the wearer is improved. The fitted state is maintained more stably. Furthermore, in this embodiment, the top sheet 2 and the back sheet 3 both have elasticity in the same direction as the longitudinal direction of the absorbent body 4 and in the same direction as the width direction. The fitted state is maintained more stably.

  In addition, it is preferable that both the surface sheet and the back sheet in the absorbent article of the present invention have at least extensibility in the same direction as the longitudinal direction of the absorbent body. Moreover, it is more preferable that both the front sheet and the back sheet have extensibility in the same direction as the longitudinal direction of the absorbent body and in the same direction as the width direction of the absorbent body. Furthermore, the top sheet preferably has stretchability in the same direction as the longitudinal direction of the absorbent body, and preferably has stretchability in the same direction as the longitudinal direction of the absorbent body and in the same direction as the width direction of the absorbent body.

  Here, “having extensibility” means that the stretch rate (length change) measured by the above-described method is 10% or more, and the stretch rate is preferably 20 to 40%. . Further, “having stretchability” means that the permanent strain of the material measured in the same manner is almost completely recoverable, and the permanent strain is preferably within 5%.

  In this napkin 1, the top sheet 2 includes a first fiber layer containing heat-shrinkable fibers and fibers that do not substantially heat shrink or fibers that do not substantially heat shrink at the shrinkage start temperature of the heat shrinkable fibers. After laminating and partially bonding the second fiber layer, an uneven sheet obtained by shrinking the first fiber layer by hot air treatment is used. In this concavo-convex sheet, the second fiber layer protrudes at a portion other than the joint portion with the first fiber layer to form a convex portion, while the joint portion forms a concave portion. The second fiber layer side of the concavo-convex sheet is used toward the wearer's skin. Since this concavo-convex sheet forms a dense layer of the contracted first fiber layer, even when the absorbent sheet 41 includes a water-absorbing polymer, even if the water-absorbing polymer leaks from the cut, It is possible to prevent the water-absorbing polymer from leaking to the skin contact surface of the napkin 1. The heat-shrinkable fiber is preferably a latent crimpable fiber. As such an uneven sheet, those described in JP 2002-187228 A, JP 2003-250836 A, JP 2004-166849 A, JP 2004-202890 A, and the like can be used.

  The top sheet 2 is not limited to the above-described concavo-convex sheet, and those conventionally used for this type of article can be used without particular limitation. Other preferable stretchable sheets that can be used as the surface sheet 2 include (a) a stretchable sheet obtained by hydrophilizing a spunbond nonwoven fabric using a urethane resin, and (b) a spunbond nonwoven fabric using a urethane resin in at least one direction. An unwoven nonwoven fabric obtained by laminating an air-through nonwoven fabric on it, laminating it with dot-like embossing, and releasing it, and (c) a film having a three-dimensional opening from an elastic resin such as urethane or EVA Examples include those formed and hydrophilized.

Moreover, as the back surface sheet 3, what is conventionally used for this kind of article can be used without particular limitation. Examples of a preferable stretchable sheet that can be used as the back sheet 3 include a film obtained from a polyolefin resin obtained using a urethane or metallocene catalyst, and a polyester-based elastic film.
In the case where an extensible or stretchable sheet is used as the top sheet 2 and / or the back sheet 3, the bonding between the two at the peripheral edge 11 of the napkin 1 can be performed using hot melt adhesive or the like from the viewpoint of not inhibiting the stretchability and stretchability. It is preferable to carry out via an adhesive.

  In the napkin 1 of the present embodiment, an absorbent sheet containing a fiber material and a water absorbent polymer is used as the absorbent sheet 41. The absorbent sheet is formed by bonding the water-absorbing polymer to the constituent fibers through the adhesive force generated in the water-absorbing polymer in the wet state or a separately added adhesive or adhesive fiber. This is preferable from the viewpoint of less dropping of the polymer.

  As the absorbent sheet 41, for example, an absorbent sheet manufactured by a method described in JP-A-8-246395, a pulverized pulp supplied on an air stream, and a water-absorbing polymer are deposited, and then an adhesive (for example, vinyl acetate) is deposited. A dry sheet solidified with an adhesive, PVA, etc.), an absorbent sheet obtained by applying a hot melt adhesive between paper and nonwoven fabric and then spraying a superabsorbent polymer, a spunbond or meltblown nonwoven fabric manufacturing process An absorbent sheet obtained by blending a superabsorbent polymer therein can be used. These absorbent sheets can be cut into a predetermined shape and used as an absorbent sheet. Also, a plurality of absorbent sheets are bonded together to form a multilayer sheet, or a single absorbent sheet is folded and the layers are bonded to form a multilayer sheet, and the multilayer sheet thus obtained is used as the absorbent sheet. You can also.

  In order to form a cut in the absorbent sheet 41, the absorbent sheet 41 may be cut by a known cutting means. However, when an absorbent sheet containing a water-absorbing polymer is used, from the viewpoint of preventing the water-absorbing polymer from leaking out. The heat-fusible material such as thermoplastic fiber and hot melt adhesive is contained in the absorbent sheet, and the heat-fusible material is melted at the same time as cutting or before and after cutting. Thus, it is also preferable to seal the cut surface so that the water-absorbing polymer does not leak out.

The present invention is advantageous in that even if an absorbent sheet having a relatively high rigidity is used, the absorbent body can be deformed into a shape as shown in FIG.
Examples of the absorber having relatively high rigidity include those having a rigidity of 30 to 300 cN, particularly 50 to 200 cN.
The rigidity here is measured as follows.
Daiei Kagaku Seisaku Seisakusho Co., Ltd .: Handometer tester, which conforms to the stiffness measurement method specified in JIS L1096 (General Textile Testing Method) is used. Place the test piece on the sample table adjusted to 30 mm between the slots so that the measurement site of the test piece is located at the center between the slots and the length of the test piece along the longitudinal direction of the absorber is orthogonal to the slot. It is arranged horizontally so that it coincides with the direction. Do not fix the specimen on the sample stage. A blade adjusted so as to descend to a position (lowermost position) 8 mm below the surface of the sample stage is lowered from above the test piece at a constant speed of 200 mm / min. Then, the maximum value (cN) indicated by the indicator (load meter) when the test piece is pressed back and forth in the length direction is read. The measurement was performed 5 times, and the average value was calculated as the stiffness value.
Note that the measurement is performed using a portion not including the slit.

The absorbent sheet preferably has a thickness of 1 to 5 mm, particularly 1.2 to 4 mm, and preferably has a basis weight of 40 to 250 g / m ² , particularly 55 to 180 g / m ^2. .

As another preferred embodiment of the present invention, an embodiment in which the width of the extensible sheet 5 is narrower than that of the absorbent sheet 41 and arranged in the center is also possible. Other constituent elements are common to the above-described embodiment.
In this embodiment, the stretchable sheet 5 in the center is bulky and hydrophilic, so that it can quickly permeate and diffuse the absorbed body fluid, but does not diffuse to the outside of the sheet 5 region, The absorbent sheet 41 can be transmitted without spreading.
The extensible sheet 5 has a function of transmitting body fluid to the absorbent sheet 41 (in the non-cut portion) as in the first embodiment in order to develop stable absorbability at the end regardless of opening and closing of the cut portion 42. . In a preferred embodiment capable of effectively transferring liquid, it is preferable that the stretchable sheet 5 covers a length of 40% or more of the cut depth L2 of the cut portion 42. Therefore, the preferred width of the stretchable sheet 5 is absorbed. It is 20% or more of body 4 width, More preferably, it is 30 to 70%.
In the present embodiment, the stretchable sheet 5 does not need to be stretched as much as the preferred embodiment 1 because it does not reach both ends of the absorbent body (the open end of the notch 42) that requires the most stretchability. In this case, the preferred elongation rate is preferably 5% or more, more preferably 7 to 40% when loaded with 50 gf. Similarly, the permanent set after stretching to a stretching rate of 30% is preferably within 13%, and more preferably within 8%.
As the stretchable sheet 5, each of the nonwoven fabrics exemplified in the first embodiment is most suitable. However, since the requirement for stretchability is low as described above, the following nonwoven fabrics are also applicable. An air-through nonwoven fabric, heat roll nonwoven fabric, spunbond nonwoven fabric, SMS, etc. using various heat-fusible fibers are partially cut. Among these, an air-through nonwoven fabric using a heat-fusible fiber having high tertiary crimp is effective.

This embodiment is particularly suitable for nighttime to long-time napkins where the absorbency at the center is sufficiently greater than the edges, and the liquid tends to spread back and forth with low activity.
On the other hand, the first embodiment can smoothly transmit the liquid to the absorbent sheet 41 even when the liquid spreads to the end, and has a high effect of restoring the notch 42 to the original position. Especially suitable for worried daytime to daytime napkins.

As mentioned above, although several embodiment of this invention was described, this invention is not restrict | limited to embodiment mentioned above, A various change is possible.
For example, the notch of the absorbent sheet 41 is not limited to the one parallel to the width direction of the absorber, and may be a notch 42 having an angle with respect to the width direction of the absorber as shown in FIG. . The cut angle with respect to the width direction of the absorber 4 can be set to, for example, 0 ° to less than 45 °, preferably 0 ° to less than 30 °.
Further, the slit of the absorbent sheet 41 is not limited to a linear one (slit), and may be a narrow triangle shape in plan view, such as a slit 42 shown in FIG.

Further, the absorbent sheet 41 may be formed with cuts 42 as shown in FIG. The notch 42 in FIG. 6C has a length that is 1/2 or more of the width of the absorbent sheet 41. Moreover, although the absorber 4 of the napkin 1 mentioned above consists of the single layer absorption sheet 41, the absorption sheet 41 may be laminated | stacked on two or more layers.
Moreover, when the nonwoven fabric which has elastic elasticity is used as the extensible sheet 5, if the both ends of a longitudinal direction are hold | gripped and pulled, this extensible sheet will extend in a longitudinal direction and the width | variety in a longitudinal direction center part will reduce. In this state, the absorbent body 4 is superposed on the absorbent body 4 and fixed to the absorbent body 4 with an annular joint (such as an embossed groove) surrounding the central portion of the absorbent body 4. Is preferable because it easily deforms into a shape that fits the wearer's body shape.

In addition to the sanitary napkin, the absorbent article of the present invention may be a panty liner (cage sheet), an incontinence pad, a disposable diaper, or the like.
In addition, the description omitted in one embodiment and the requirements of only one embodiment can be applied to other embodiments as appropriate, and the requirements in each embodiment can be appropriately applied between the embodiments. Can be substituted for each other.

1 is a perspective view illustrating a sanitary napkin according to an embodiment of the present invention with a part thereof broken. It is the II-II line schematic cross section of FIG. It is a figure which shows the extensible sheet | seat and the absorption sheet in the sanitary napkin shown in FIG. It is a top view which shows the preferable embossing pattern of the embossing given to the nonwoven fabric used as an extensible sheet. It is a perspective view which shows the deformation | transformation shape at the time of wear of the sanitary napkin shown in FIG. It is a top view which shows the absorber in other embodiment of this invention.

Explanation of symbols

1 Sanitary napkin (absorbent article)
2 Top sheet 3 Back sheet 4 Absorber 41 Absorbent sheet 42 Notch 5 Extensible sheet 6 Shorts (underwear)

Claims (5)

An absorbent article comprising a liquid-permeable top sheet, a back sheet and a vertically long absorbent interposed between the two sheets,
The absorbent body is composed of an absorbent sheet, and the absorbent sheet has notches extending inward in the width direction from both side edges in the longitudinal direction,
On the surface of the absorbent sheet on the surface sheet side, an extensible sheet made of non-woven fabric with less liquid holding capacity than the absorbent sheet is disposed ,
The extensible sheet is an absorbent article that is disposed in a central portion in the width direction of the absorbent sheet and covers a length of 40% or more of the cut depth L2 of the cut . The extensible sheet, when is extended the sheet in the same direction as the longitudinal direction of the absorbent body is elongation percentage of 10% or more at a load 50 gf, the absorbent article according to claim 1 Symbol placement.   The absorptive article according to claim 1 or 2 in which said extensibility sheet consists of a spunbond type nonwoven fabric containing an elastic fiber, or consists of a nonwoven fabric containing a crimped fiber. The nonwoven fabric constituting the stretchable sheet, embossing is applied, the absorbent article of any one of claims 1 to 3. Each of said topsheet and said backsheet, has a longitudinal and stretch in the same direction of at least the absorbent body, the absorbent article of any of claims 1-4.

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