JP4520475B2 - Absorbent article using continuous filament surface structure - Google Patents

Description

  The present invention relates to an absorbent article such as a disposable diaper or a sanitary napkin having a surface structure formed of continuous filaments.

  In conventional absorbent articles such as disposable diapers and sanitary napkins, a liquid-impermeable back sheet is stacked on the back side of the absorbent layer, and a liquid-permeable top sheet is stacked on the surface side that is the liquid receiving side. Yes.

  The surface sheet of the conventional absorbent article is formed of a liquid-permeable nonwoven fabric or a synthetic resin film having a large number of apertures. However, since the thickness of the conventional surface sheet is constant in the width direction, it is difficult to properly adhere to the excretion site of the wearer, a gap is formed between the excretion site and the surface sheet, There arises a problem that the excreted liquid leaks to the side along the surface sheet.

  Therefore, for example, in Patent Document 1 below, there is a jetty formed by deforming the central portion of the liquid-permeable surface layer so as to rise toward the wearer, and this jetty hits the excretion site of the wearer. It is disclosed.

Further, as a means for preventing liquid leakage from occurring laterally along the surface layer, there has conventionally been a method in which a leak-proof wall extending in the vertical direction is formed on both sides of the surface layer. The leak-proof wall is formed of a hydrophobic sheet rising from the surface sheet and an elastic member provided on the top of the sheet, and the hydrophobic sheet is raised from the surface sheet by a contraction force of the elastic member. Is.
JP 9-322908 A

  However, since the thing of the said patent document 1 deform | transforms the surface layer so that a center part may protrude as a structure for forming a protruding part in the center part of an absorbent article, the structure of a surface layer is It is very complex and expensive to manufacture.

  Further, even in the case where the leakage prevention wall is formed by a hydrophobic sheet as in the conventional case, in order to form the leakage prevention wall, the hydrophobic sheet is joined to the surface sheet, or the hydrophobic sheet is formed. A manufacturing process, such as joining an elastic member, is required. Therefore, there is a limit to reducing the manufacturing cost.

  The present invention solves the above-mentioned conventional problems, when forming a raised portion that contacts the excretion site of the wearer in the central portion on the liquid receiving side, or when forming a bank that prevents liquid leakage on both sides An object of the present invention is to provide an absorbent article that can be manufactured very easily and can soften the feeling of contact with the skin of the wearer.

The present invention relates to an absorbent article having a liquid-permeable surface structure, a back sheet, and an absorbent layer positioned between the surface structure and the back sheet.
When the direction from the ventral side to the butt side when worn is the vertical direction, and the direction perpendicular to it is the horizontal direction,
The surface structure, which layer of heat-fusible continuous filaments extending without being opened from the toe interrupted in the longitudinal direction are stacked two or more layers,
The lower layer located on the absorption layer side has a predetermined width dimension, the upper layer located on the surface side has a width dimension shorter than the lower layer, and the upper layer is located at the center or both sides of the lower layer,
The surface of all of the layers of two or more layers of the continuous filament of the structure, are joined sheets by a plurality of bonding lines extending in the horizontal direction at intervals in the longitudinal direction, placed on the absorbing layer It is characterized by being.

  For example, it is preferable that the lower layer has higher hydrophilicity than the upper layer. In this case, the upper layer is formed of a hydrophobic continuous filament that has not been subjected to a hydrophilic treatment, and the lower layer is formed of a hydrophobic continuous filament or a hydrophilic continuous filament that has been subjected to a hydrophilic treatment.

  Further, the density of the continuous filament in the upper layer is different from the density of the continuous filament in the lower layer, and preferably the density of the continuous filament in the lower layer is higher than the density of the continuous filament in the upper layer It is.

  The continuous filament bundle may be two layers of a lower layer and an upper layer, but are laminated in order of the lower layer, the middle layer, and the upper layer from the absorption layer side, and the width dimension becomes shorter in the order of the lower layer, the middle layer, and the upper layer. It may be what you have.

  In this case, the hydrophilicity increases in the order of the upper layer, the middle layer, and the lower layer. For example, the upper layer is formed of a hydrophobic continuous filament that has not been subjected to a hydrophilic treatment.

  Furthermore, the density of continuous filaments may be different between the lower layer, the middle layer, and the upper layer. In this case, it is preferable that the density of the continuous filament is higher in the order of the upper layer, the middle layer, and the lower layer.

Further, the upper layer is located on both sides in the lateral direction, and the upper layer can be configured to be water repellent.

  In the present invention, since the surface structure is formed of continuous filaments, the density is low and the bulk is high, and the wearer's skin is soft. In particular, since continuous filaments are continuous in the longitudinal direction in the surface structure, filament ends do not appear on the surface, and the surface is smooth.

  In this continuous filament surface structure, by changing the hydrophilicity and / or density between the upper layer and the lower layer, the liquid permeability in the surface structure is improved, and the effect of preventing the liquid from returning is increased.

  Also, continuous filaments with different hydrophilicities and continuous filaments with different densities are continuously fed out and partially fused to make surface structures having layers with different hydrophilicities and / or densities very simple. Can be manufactured.

  In the present invention, the surface structure of the absorbent article can be made to have a good liquid permeability and hardly cause the liquid to reverse, and has a soft touch to the skin and an excellent cushioning property. Further, it is possible to produce a surface structure having a different volume and more preferably having a different hydrophilicity and density by a simple process of simply stacking multi-layer continuous filament bundles.

  FIG. 1 is a plan view of a disposable diaper as a first embodiment of the absorbent article according to the present invention as seen from the liquid receiving side, FIG. 2 is a sectional view of the disposable diaper, and FIG. 3 is used for the disposable diaper. It is a fragmentary perspective view of a surface structure. FIG. 4 is a cross-sectional view of a disposable diaper according to another embodiment of the present invention, and FIG. 5 is a partial perspective view of a surface structure used in the disposable diaper of FIG.

  FIG. 1 shows a disposable diaper 1 developed in a planar shape, with the X direction being the width direction and the Y direction being the vertical direction. The disposable diaper 1 has an hourglass shape having an intermediate part 2 attached to the crotch part, a front part 3 applied to the abdomen side, and a rear part 4 applied to the buttocks side.

  As shown in the cross-sectional view of FIG. 2, the disposable diaper 1 has an absorbent core (absorbing layer) 8 superimposed on a liquid-impermeable back sheet 7. As shown in FIG. 1, the absorbent core 8 has an hourglass shape and occupies from the middle of the front part 3 to the middle of the rear part 4 through the intermediate part 2. A liquid-permeable surface structure 10 formed of continuous filaments is overlaid on the liquid-receiving surface of the absorbent core 8.

  As shown in FIG. 2, liquid-impervious side sheets 9, 9 are joined to both sides of the surface structure 10, and these side sheets 9, 9 are connected to the left and right sides of the intermediate part 2. The flaps 6a, 6a, the flaps 6b, 6b on both sides of the front part 3 and the flaps 6c, 6c on both sides of the rear part 4, and the back sheet 7 and the side sheets 9, 9 is joined with a hot-melt adhesive or the like.

  The said back surface sheet 7 is liquid-impermeable, and is a moisture-permeable resin film or a nonwoven fabric, or the resin film and the nonwoven fabric joined. The absorbent core 8 is a mixture of pulverized pulp and SAP, and is further wrapped with liquid-permeable paper, or airlaid pulp, absorbent paper, or hydrophilic fiber formed into a sheet by binder treatment. Non-woven fabric mainly composed of

  The side sheet 9 is formed of a nonwoven fabric such as an air-through nonwoven fabric, a point bond nonwoven fabric, a spunbond nonwoven fabric, a spunlace nonwoven fabric, a melt blown nonwoven fabric, or an airlaid nonwoven fabric, and is preferably hydrophobic or water repellent.

  As shown in FIGS. 2 and 3, the surface structure 10 is formed of three layers: a lower layer 10a located on the absorption layer 8 side, an intermediate layer 10b thereon, and an upper layer 10c located further thereon. . The lower layer 10a has a predetermined width dimension W including the central portion of the liquid absorption region of the disposable diaper and is formed in a belt shape. The middle layer 10b has a width dimension shorter than that of the lower layer 10a, and the upper layer 10c has a width dimension shorter than that of the middle layer 10b.

  The middle layer 10b is located at the center of the lower layer 10a, and the upper layer 10c is located at the center of the middle layer 10b. Therefore, the surface structure 10 has a central convex shape in which the basis weight and the bulk are low at both sides in the X direction, and the basis weight and the bulk increase toward the center.

  The lower layer 10a is a bundle of continuous filaments 11a that are continuous in the Y direction in the surface structure 10, and similarly, the middle layer 10b and the upper layer 10c are also continuous filaments 11b and 11c that are continuous in the Y direction. It is a bunch.

  The continuous filaments 11a, 11b, and 11c are opened from a convergent body called a tow (TOW) in which the filaments are crimped and converged. By this opening, the individual continuous filaments 11a, 11b, and 11c are loosened and separated to form a uniform bulk in the width direction, thereby forming the lower layer 10a, the middle layer 10b, and the upper layer 10c.

  The continuous filaments 11a, 11b, and 11c are formed of a heat-synthesizable hydrophobic synthetic resin, such as a composite synthetic fiber having a core-sheath structure such as PE / PET or PE / PP, PE / PET, or PE / PP. It is a side-by-side type composite fiber or a single fiber such as PE, PP, or PET. Further, it is preferable that the continuous filaments 11a, 11b, and 11c contain 0.5 to 10% by mass of an inorganic filler for whitening such as titanium oxide. By the whitening treatment, the urine absorbed in the absorbent core 8 can be easily concealed on the appearance. The fiber cross section of the continuous filament may be round or irregular.

  The crimps are crimped at the time of filament production, and the number of crimps is increased by preheating calendering or hot air treatment. Or you may pass through a pre-heating calendar | calender and it may produce the distortion in the orientation of resin which forms a filament by repeating extending | stretching and cancellation | release of extending | stretching at this time, and may be made to crimp in the shape of a coil.

  The converging body of the crimped continuous filaments is transferred between transfer rolls. At this time, tension is applied in the extending direction of the filaments, and the tension is released. By repeating this process, the continuous filaments are individually separated. It is opened to separate. Alternatively, a sliding plate can be applied from both sides to the converging body transferred between transfer rolls, the converging body can be slid on the sliding plate, and individual filaments can be separated and opened by the sliding force. . The bundle of continuous filaments opened from the converging body has a reduced filament density and an increased apparent width.

  Further, the bundle of continuous filaments opened is expanded so that the bulk thereof is uniform in the X direction in the widening step, and the lower layer 10a having the width dimension W and the middle layer 10b and the upper layer 10c having a smaller width dimension are respectively provided. It is formed.

  A bundle of continuous filaments 11b to be the middle layer 10b and a bundle of continuous filaments 11c to be the upper layer 10c are stacked on the bundle of continuous filaments 11a to be the lower layer 10a that has been opened and widened. And the joining line 12 is formed by the uneven | corrugated embossing etc. which were formed in the surface of the fuse | melting roll. In this joining line 12, the continuous filament 11a of the lower layer 10a, the continuous filament 11b of the middle layer 10b, and the continuous filament 11c of the upper layer 10c are thermally fused to each other, or are fused by induction heating with ultrasonic waves to form a sheet.

  As shown in FIGS. 1 and 3, the bonding lines 12 extend linearly in the X direction, and each bonding line 12 is formed with a certain pitch P in the Y direction. However, the planar pattern of the joining line may be a continuous curve approximated to a trigonometric function curve, or may be V-shaped. Alternatively, it may be an intermittent joining line formed with a certain interval in the X direction. Alternatively, the continuous filament may be fused not by the joining line but by a joining portion such as a circular shape distributed in a dot shape.

  The surface structure 10 can be easily manufactured by a process in which bundles of continuous filaments constituting the lower layer 10a, the middle layer 10b, and the upper layer 10c are sent out in the Y direction and laminated, and bonded with a fusion roll as described above. it can. In addition, the width dimension, basis weight and bulk of each layer can be freely changed, and the number of layers is not limited to three layers as in the embodiment of the figure, but can be two layers of only a lower layer and an upper layer, and four or more layers. It is easy to make a multilayer structure.

  As shown in FIG. 3, the thickness of the portion of the lower layer 10a only is T1, the thickness of the portion where the lower layer 10a and the middle layer 10b are overlapped is T2, and the thickness of the central portion where the lower layer 10a, the middle layer 10b and the upper layer 10c are stacked is It is T3, and the thickness and the basis weight are different in each portion facing the width direction (X direction).

For example, the thickness T1 is 5 to 8 mm, T2 is 8 to 15 mm, and T3 is 15 to 25 mm. The basis weight of the portion of the thickness T1 is 25~75g / ^{m 2,} in a portion of the thickness T2, a 75~100g / ^{m 2,} in a portion of the thickness T3 is 100 to 200 g / ^{m 2.}

The average density of the filaments of the entire surface structure 10 including the lower layer 10a, the middle layer 10b, and the upper layer 10c is 0.002 to 0.01 g / cm ³ .

  Moreover, the fineness of the continuous filaments 11a, 11b, and 11c of each layer is 1.1 to 20 dtex, and more preferably 1.1 to 11 dtex.

  The number of crimps of the continuous filaments 11a, 11b, and 11c is 5 to 30, more preferably 15 to 30 per inch, and the crimp elastic modulus is preferably 70% or more.

  The number of crimps is based on JISL1015, and the crimp elastic modulus is based on JISL1074. In the case of a filament having a fineness of less than 5.5 dtex, an initial load of 0.49 mN is applied in the tensile direction, and the filament having a fineness of 5.5 dtex or more is applied. In this case, an initial load of 0.98 mN is applied in the tensile direction. The number of crimps is the number of crimps per inch (25 mm) when the initial load is applied.

  Further, the length of the filament when the initial load is applied is a, the length when the crimp is extended by applying a tension of 4.9 mN per 1.1 dtex for 30 seconds, and the tension is removed. When the length when the initial load is applied again after a minute has elapsed is c, the crimp elastic modulus is represented by {(bc) / (ba)} × 100 (%). .

  In the disposable diaper 1 using the surface structure 10, since the portion that contacts the skin is formed of continuous filaments, the fiber ends do not appear on the surface, the contact with the skin is smooth, and the continuous filament follows the skin. Because it can move, it is less irritating to the skin. Moreover, it is bulky and has excellent cushioning properties.

  Moreover, since the surface structure 10 shown in FIG. 2 and FIG. 3 is thick in the central part, when it is used for girls, the part of the central part having a thickness T3 is in close contact with the excretion site of the wearer. Cheap. Therefore, excretion fluid such as urine is given to the upper layer 10 c that is in close contact with the surface structure 10 without being dispersed right and left and given to the absorbent core 8. Since the wearer's excretion site and the surface structure 10 are likely to be in close contact with each other, and a gap is not easily formed between the excretion site and the surface structure 10, side leakage such as urine is less likely to occur.

  Furthermore, since the continuous filaments 11a, 11b, and 11c extend in the longitudinal direction (Y direction) of the disposable diaper 1, the liquid guiding direction becomes the longitudinal direction, and lateral leakage in the lateral direction (X direction) can be reduced. Moreover, since the continuous filaments 11a, 11b, and 11c are joined by the joining lines 12 that are spaced apart at a constant pitch P in the longitudinal direction, diffusion of the liquid in the longitudinal direction in the surface structure 10 can be suppressed, and the liquid It becomes easy to guide to the absorption layer 8.

  In the surface structure 10, the hydrophilicity of the continuous filament is changed in each layer. For example, the lower layer 10a has higher hydrophilicity than the upper layer 10c, or the upper layer 10c, the middle layer 10b, and the lower layer 10a have higher hydrophilicity in order. It is possible to configure. Alternatively, the density of the filaments in each layer can be made different, for example, the density of the upper layer 10c can be higher than the density of the lower layer 10a, or the filament density of the lower layer 10a can be higher than the filament density of the upper layer 10c. It is also possible to give a difference in both hydrophilicity and density between the respective layers.

  For example, when the degree of hydrophilicity is increased as it goes to the lower layer, urine or the like given to the upper layer 10c is attracted by the continuous filament of the lower layer, so that urine can be easily guided to the absorbent core 8, and the upper layer side is made hydrophobic. By having a configuration with low property or hydrophilicity, it is possible to effectively prevent urine absorbed by the absorbent core 8 from returning to the skin side of the wearer. Similarly, when the density is increased on the lower layer side, urine or the like given to the upper layer side is drawn by the capillary action in the higher density layer, and the liquid permeability to the absorbent core 8 can be improved. In addition, it is difficult for urine to return to the wearer.

  Here, the difference in hydrophilicity means a difference in surface chemical properties of the surface in the case of a hydrophobic filament, and the lower the water contact angle, the higher the hydrophilicity. The hydrophilic filament is attracted to moisture by the hydrophilic group on the surface, and the hydrophilicity is different depending on the hydrophilic group. That is, the hydrophilicity is higher in the filament that can attract more moisture by the hydrophilic group. Further, in hydrophobic fibers and hydrophilic fibers that have been subjected to hydrophilic treatment, the hydrophilicity increases as the surface area increases when compared per unit mass.

  When the continuous filament is a hydrophobic filament such as PE / PP or PE / PET core-sheath type composite fiber, and the hydrophilic oil agent is applied to the surface of the continuous filament and the hydrophilic treatment is performed, the hydrophilic A difference in the hydrophilicity can be provided by using oil agents having different durability against liquids.

  For example, the continuous filaments of the upper layer 10c and / or the middle layer 10b are coated with an initial hydrophilic oil agent, that is, a hydrophilic oil agent that is relatively easy to fall off when contacted with water or other liquids. Such initial hydrophilic oil agents include PEG-modified polyester, polyoxyethylene alkyl sulfate, alkyl phosphate ester K salt, polyoxyethylene alkyl ester, alkylsulfonate Na salt and the like.

  On the other hand, a durable hydrophilic oil that is less likely to fall off with water or liquid than the initial hydrophilic oil is applied to the continuous filament of the lower layer 10a. Examples of the durable hydrophilic oil agent include polyether ester, ether nonion, polyether-modified silicone, sulfosuccinate, polyoxyethylene amide ether, alkyl imidazoline type cation, and polyglycerin polyester.

  Thus, by selecting the kind of hydrophilic oil agent, the durability of the hydrophilic oil agent with respect to the liquid on the lower layer 10a side can be enhanced, and the hydrophilicity of the lower layer 10a can be made higher than the hydrophilicity of the middle layer 10b and the upper layer 10c. Further, the upper layer 10c is formed of a hydrophobic filament not subjected to hydrophilic treatment, the initial hydrophilic oil agent is applied to the filament of the middle layer 10b, and the durable hydrophilic oil agent is applied to the filament of the lower layer 10a, whereby the upper layer 10c, the middle layer 10b, and the lower layer 10a. The hydrophilicity can be increased in order.

  Alternatively, the hydrophilicity can be varied by changing the coating amount of the hydrophilic oil agent per 1 dtex of the continuous filament. For example, the upper layer 10c is not applied to the continuous filament 11c of the upper layer 10c, but is applied a little to the continuous filament 11b of the middle layer 10b, and more hydrophilic oil is applied to the continuous filament 11a of the lower layer 10a. The hydrophilicity can be increased in the order of the middle layer 10b and the lower layer 10a.

  Also, the upper layer 10c is composed of hydrophobic continuous filaments that are not hydrophilically treated, the middle layer 10b is composed of hydrophobic continuous filaments that are hydrophilically treated, and the lower layer 10a is composed of hydrophilic continuous filaments such as cellulose acetate. The hydrophilicity can be increased in the order of the upper layer 10c, the middle layer 10b, and the lower layer 10a.

  Further, for example, short fibers such as natural cellulose fibers may be fixed to the hydrophobic continuous filament constituting the lower layer 10a with an adhesive or the like to increase the hydrophilicity of the lower layer 10a.

  Next, the density difference can be adjusted by changing the fineness of the continuous filament. For example, the density can be increased by using a continuous filament having a small fineness. Due to this difference in fineness, the density of the lower layer 10a can be made higher than that of the upper layer 10c, or the density can be increased in the order of the upper layer 10c, the middle layer 10b, and the lower layer 10a.

  In addition, the density between the layers can be made different by changing the number of crimps of the continuous filament and / or changing the crimp elastic modulus. For example, the density can be increased by increasing the number of continuous filament crimps. The density can also be lowered by increasing the crimp elastic modulus.

  Next, in the disposable diaper 1A whose sectional view is shown in FIG. 4, the surface structure 20 shown in FIG. 5 is used instead of the surface structure 10 shown in FIG. The structure of the diaper other than the surface structure 20 is exactly the same as in FIGS.

  In the surface structure 20 of this embodiment, a lower layer 20a, an intermediate layer 20b, and an upper layer 20c are stacked in this order, and the width dimension becomes shorter in the order of the lower layer 20a, the intermediate layer 20b, and the upper layer 20c. The lower layer 20a, the middle layer 20b, and the upper layer 20c having uniform bulk are formed by continuous filaments 21a, 21b, and 21c opened from a converging body called a tow where the crimped filaments are converged. Each filament extends continuously in the Y direction without interruption.

  However, in this embodiment, the middle layer 20b is located on the left and right sides of the lower layer 20a, and the upper layer 20c is located on the left and right sides. And each continuous filament which comprises the lower layer 20a, the middle layer 20b, and the upper layer 20c is mutually fuse | fused by the joining line 22 formed with the predetermined pitch P in the Y direction.

  Moreover, thickness T1, T2, T3 of each part shown in FIG. 5 and the fabric weight of each part are the same as the surface structure 10 shown in FIG. Further, the fineness of the continuous filament and the average density of the surface structure 20 are the same as those of the surface structure 10.

  The disposable diaper 1A shown in FIG. 4 is particularly suitable as a boy's diaper because the bulky surface structure 20 is used on both sides. In the surface structure 20, the middle layer 20 b and the upper layer 20 c are positioned on both the left and right sides, and the thickness is increased. Therefore, the middle layer 20 b and the upper layer 20 c function as a leakage barrier that substantially prevents urine lateral leakage. .

  Further, similarly to the surface structure 10 shown in FIG. 3, the hydrophilicity of the lower layer 20a may be made higher than that of the upper layer 20c, or the hydrophilicity may be made higher in the order of the upper layer 20c, the middle layer 20b, and the lower layer 20a. Alternatively / further, the filament density of the lower layer 20a may be higher than that of the upper layer 20c, or the filament density may be increased in the order of the upper layer 20c, the middle layer 20b, and the lower layer 20a.

  In order to increase the leakage prevention effect, the density of the upper layer 20c may be higher than the density of the lower layer 20a, or the density may be increased in the order of the lower layer 20a, the middle layer 20b, and the upper layer 20c. In addition, a hydrophobic continuous filament that has been subjected to a hydrophilic treatment as the continuous filament 21a of the lower layer 20a, and functions as a leakage barrier that prevents lateral leakage of urine and the like by subjecting at least one of the middle layer 20b and the upper layer 20c to water repellency treatment Can be high.

  In the embodiment shown in FIG. 4 and FIG. 5, the leakage barrier is formed by a process in which the middle layer 20 b and the upper layer 20 c which are bundles of continuous filaments are overlapped with the bundle of continuous filaments in the lower layer 20 a and are partially fused. it can. Therefore, the leakage barrier can be formed with a simpler structure than the conventional leakage barrier made of the hydrophobic sheet and the elastic member.

  In the surface structures 10 and 20 shown in FIGS. 3 and 5, the middle layers 10b and 20b may be omitted, and a two-layer structure of the lower layers 10a and 20a and the upper layers 10c and 20c may be used.

  FIG. 6 is a perspective view showing a sanitary napkin 30 as an absorbent article according to another embodiment of the present invention.

  In this sanitary napkin 30, an absorption layer is installed on a liquid-impermeable back sheet 31, and a surface structure 10A having a structure similar to the surface structure 10 shown in FIG. 3 is installed thereon. Further, the leak-proof walls 32, 32 on both sides are formed of a hydrophobic sheet, and the hydrophobic sheet is joined to the back sheet 31 at the flaps 33, 33 on both sides.

  The surface structure 10A of the sanitary napkin 30 is similar to the surface structure 10 shown in FIG. 3, in which the middle layer 10b of the continuous filament bundle is similarly overlapped with the center of the lower layer 10a of the continuous filament bundle, and the center above it is further centered. The upper layer 10c of the continuous filament bundle is superposed on the part. However, the upper layer 10 c is provided only at the center in the vertical direction of the sanitary napkin 30.

  The continuous filaments of the lower layer 10a, the middle layer 10b, and the upper layer 10c are partially fused by a curved line-shaped joining line 12A to form a sheet. In the surface structure 10A, since the central portion is raised, the surface structure 10A can be in close contact with the excretion site of the wearer, and side leakage of menstrual blood is easily prevented.

  Further, as described above, by increasing the hydrophilicity and / or increasing the density in the order of the upper layer 10c, the middle layer 10b, and the lower layer 10a, the liquid permeability can be improved and the liquid can be prevented from returning. . The surface structure 10A may also be composed of only two layers, a lower layer 10a and an upper layer 10c.

  In each of the above embodiments, the surface structure is formed only by a bundle of continuous filaments. However, a liquid-permeable nonwoven fabric sheet is stacked under the bundle of continuous filaments forming each layer, and the layers are continuously formed. The filament and the nonwoven sheet may be joined together to form a surface structure.

The top view which shows a disposable diaper from liquid receiving side as embodiment of this invention, Sectional drawing of the disposable diaper shown in FIG. The fragmentary perspective view of the surface structure currently used for the disposable diaper shown in FIG. Sectional drawing of the disposable diaper of other embodiment, The fragmentary perspective view of the surface structure currently used for the disposable diaper shown in FIG. The perspective view which shows the sanitary napkin as other embodiment of this invention,

Explanation of symbols

1, 1A Disposable diaper 2 Middle part 3 Front part 4 Rear part 7 Back sheet 8 Absorbent core 10, 10A, 20 Surface structure 10a, 20a Lower layer 10b, 20b Middle layer 10c, 20c Upper layer 11a, 11b, 11c, 21a, 21b , 21c Continuous filament 12, 12A, 22

Claims (11)

In an absorbent article having a liquid-permeable surface structure, a back sheet, and an absorbent layer located between the surface structure and the back sheet,
When the direction from the ventral side to the butt side when worn is the vertical direction, and the direction perpendicular to it is the horizontal direction,
The surface structure, which layer of heat-fusible continuous filaments extending without being opened from the toe interrupted in the longitudinal direction are stacked two or more layers,
The lower layer located on the absorption layer side has a predetermined width dimension, the upper layer located on the surface side has a width dimension shorter than the lower layer, the upper layer is located at the center or both sides of the lower layer,
The surface of all of the layers of two or more layers of the continuous filament of the structure, are joined sheets by a plurality of bonding lines extending in the horizontal direction at intervals in the longitudinal direction, placed on the absorbing layer Absorbent article characterized by being made.   The absorbent article according to claim 1, wherein the lower layer has a higher hydrophilicity than the upper layer.   The absorbent article according to claim 2, wherein the upper layer is formed of a hydrophobic continuous filament that has not been subjected to a hydrophilic treatment, and the lower layer is formed of a hydrophobic continuous filament or a hydrophilic continuous filament that has been subjected to a hydrophilic treatment.   The absorbent article according to any one of claims 1 to 3, wherein a density of the continuous filaments in the upper layer is different from a density of the continuous filaments in the lower layer.   The absorbent article according to claim 4, wherein the density of the continuous filaments in the lower layer is higher than the density of the continuous filaments in the upper layer.   The absorbent article according to claim 1, wherein the continuous filament bundle is laminated in the order of the lower layer, the middle layer, and the upper layer from the absorbent layer side, and the width dimension is shortened in the order of the lower layer, the middle layer, and the upper layer.   The absorptive article according to claim 6 whose hydrophilicity becomes high in order of said upper layer, middle layer, and lower layer.   The absorbent article according to claim 7, wherein the upper layer is formed of a hydrophobic continuous filament that has not been subjected to a hydrophilic treatment.   The absorbent article according to any one of claims 6 to 8, wherein the density of continuous filaments is different between the lower layer, the middle layer, and the upper layer.   The absorbent article according to claim 9, wherein the density of continuous filaments increases in the order of the upper layer, the middle layer, and the lower layer. The absorbent article according to any one of claims 1 to 10, wherein the upper layer is located on both sides in the lateral direction, and the upper layer is water-repellent.

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