JP6257297B2 - 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.

  Conventionally, it has been known that an absorbent body in an absorbent article such as a sanitary napkin is provided with a raised portion along the uneven shape of the wearer's skin, and it is also known that a groove is formed in the raised portion. ing. For example, Patent Documents 1 and 2 disclose an absorber having a raised portion having a groove near the center of the absorber.

  Patent Document 3 discloses a technique for improving the diffusion and holding performance of body fluid by arranging a high-density region in a region including both sides of the middle and high portions provided in the excretory portion facing portion.

JP 2009-112590 A JP 2012-125366 A JP 2011-120696A

The absorber in Patent Document 1 has a laminated structure having an upper layer and a lower layer, and a depression extending over the upper and lower layers is formed in a central region where the upper layer exists and forms a raised portion. However, the recess is formed by hot embossing, and since the vicinity of the bottom of the recess is consolidated, the liquid hardly diffuses from the vicinity of the bottom of the recess to other parts, preventing wetback performance and absorption. There is room for improvement in terms of effective utilization of the body's absorption capacity.
Patent Document 2 discloses a structure in which a bump having a plurality of convex portions is provided on an absorber having a large number of block-shaped convex portions, and the density of the block absorbing portions in the middle and high portions is made higher than the surroundings. Is disclosed. However, the density of the middle and high block absorption parts is increased by compressing the entire block absorption part, and since the density of the block absorption part is uniform, the body fluid diffusibility from the liquid excretion part to the surrounding part is improved. There is room for improvement, and as a result, there is room for improvement in terms of wetback prevention performance and effective utilization of the absorbent capacity.
Moreover, in patent document 3, it has the middle-high part installed in the excretion part opposing part, compresses the both sides along the absorbent article longitudinal direction of a medium-high absorber, and the center part of an absorbent article width direction has a relative density. An absorbent body is disclosed in which the side portion including at least a part of the side portion of the middle-high portion is relatively high in density. However, since it does not have a vertical groove that allows liquid to pass through quickly, the absorption speed of the liquid is slow, providing a dry feeling to the wearer quickly, and the absorption capacity of the absorber is effective by allowing the liquid to penetrate quickly into the absorber. There is room for improvement in terms of utilization.

  Therefore, the subject of this invention is providing the absorbent article which can improve the performance of the prior art mentioned above more.

  The present invention is an absorbent article provided with an absorbent core having a long shape in the front-rear direction of the absorbent article, the absorbent core having a central region and lateral regions located on both sides thereof in the width direction. And the central region has a protruding portion that protrudes upward from the upper surface of each of the lateral regions, and the absorbent core is integrally formed with the central region and the lateral regions. , Both sides in the width direction of the central region are compressed and have a high density portion having a higher density than the protrusion located on the inner side in the width direction, and the skin contact surface of the protrusion has the absorption A longitudinal groove having a bottom portion is formed on the non-skin contact surface side, which is formed by reducing the basis weight of the absorbent core forming material along the longitudinal direction of the absorbent core. The present invention provides an absorbent article in which the width of the bottom is narrow.

  The absorbent article of the present invention has high body fluid absorption performance and is effective in suppressing side leakage of body fluids.

FIG. 1 is a perspective view showing a sanitary napkin according to an embodiment of the present invention. 2A is a cross-sectional view taken along the line IIa-IIa in FIG. 1, and FIG. 2B is a cross-sectional view taken along the line IIb-IIb in FIG. Drawing 3 is an explanatory view of an example of a method of forming a high-density part whose density is higher than a projection part and whose basic weight is higher than a side area in both sides of a central area. FIG. 4 is a schematic view showing a deformed state of the absorbent core when the sanitary napkin of FIG. 1 is worn. FIG. 5 is a schematic view showing a cross section along a circumferential direction of a fiber pile drum preferably used for manufacturing the absorbent core of the sanitary napkin shown in FIG. FIG. 6 is an explanatory diagram of an example of a method for forming the compressed portion that is indented into the vertical groove.

The present invention will be described below based on preferred embodiments with reference to the drawings.
A sanitary napkin 1 (hereinafter also simply referred to as napkin 1) as an embodiment of the absorbent article of the present invention is a night napkin suitable for use at bedtime, and preferably has a length of 30 cm or more. Is.
As shown in FIG. 1, the napkin 1 has an absorbent main body 6 that is long in the front-rear direction, a pair of wing portions 7, 7, and a pair of rear flap portions 8, 8. With respect to absorbent articles such as sanitary napkins, the “front-rear direction” is a direction that coincides with the wearer's front-rear direction when worn. Moreover, in this specification, the front-back direction is a longitudinal direction, and the direction orthogonal to this is called a width direction.
The absorptive main body 6 has a front part A, a liquid excretion part facing part B, and a rear part C in its longitudinal direction, and a pair of wing parts 7 and 7 on the left and right sides of the liquid excretion part facing part B. The left and right sides of the part C have a pair of rear flap parts 8 and 8. The liquid excretion part facing part B is a part in which the central part in the width direction is disposed to face the wearer's liquid excretion part (vagina opening), and the front part A is the front side of the wearer from the liquid excretion part facing part B ( The rear part B is a part arranged on the back side of the wearer from the liquid excretion part facing part B.

  The napkin 1 includes a skin-side sheet 2 that forms a skin contact surface that faces the wearer's skin when worn, a non-skin-side sheet 3 that forms a non-skin contact surface that faces the clothing side such as shorts when worn, And the absorptive core 4 arrange | positioned between these both sheets 2 and 3 is provided. The skin-side sheet 2 includes a liquid-permeable surface sheet 2a and a pair of three-dimensional guard forming sheets 2b and 2b joined to both sides thereof. The liquid permeable top sheet 2 a is arranged at the center in the width direction of the absorbent main body 6 so as to cover the entire length of the absorbent main body 6. The three-dimensional guard forming sheet 2b is formed in such a manner that the side edge 21 on the center side in the width direction of the absorbent main body is overlapped on the surface sheet 2a at a position slightly outward from the side edge 21 in the width direction. 2a. The solid guard forming sheet 2b has an elastic member (not shown) for forming a solid guard in the vicinity of the side edge portion 21, and when worn, due to the contraction force of the elastic member, the liquid excretion portion facing portion A solid guard is formed by standing so that a portion having a predetermined width from the side edge portion 21 in B is separated from the top sheet 2a.

  The pair of wing portions 7, 7 and the pair of rear flap portions 8, 8 are composed of a three-dimensional guard forming sheet 2 b and a non-skin side sheet 3 extending from both side edges of the absorbent core 41. A wing portion adhesive portion (not shown) for fixing to the non-skin contact surface of the crotch portion of the shorts is provided on the surface formed of the non-skin side sheet 3 of each of the pair of wing portions 7. The non-skin contact surface is provided with a main body adhesive portion (not shown) for fixing the main body 6 to the inner surface of the shorts. The rear flap 8 is arranged on the inner surface (skin contact surface) of the shorts when worn. It is preferable that an adhesive portion for fixing to the inner surface of the shorts is also provided on the surface of the rear flap portion 8 made of the non-skin side sheet 3. The skin-side sheet 2 and the non-skin-side sheet 3 are joined to each other from the periphery of the absorbent core 41 with an adhesive and are joined to each other at the periphery of the napkin 1 by heat sealing. The skin-side sheet 2 and the absorbent core 41 and the absorbent core 41 and the non-skin-side sheet 3 are also joined to each other by a pattern-coated adhesive such as dots, spirals, and stripes. Is preferred.

  The absorbent core 4 in the napkin 1 is composed of a fiber assembly made of a fiber material such as pulp fiber or a superabsorbent polymer held between fibers of the fiber assembly. The upper and lower surfaces of the absorbent core 4 are covered with a core wrap sheet (not shown) made of tissue paper or a water-permeable nonwoven fabric. The core wrap sheet is used for the purpose of preventing leakage of the forming material of the absorbent core or improving the shape retention of the absorbent core.

As shown in FIG. 1, the absorbent core 4 in the napkin 1 has a shape that is long in the same direction as the front-rear direction of the napkin 1. Moreover, the absorptive core 4 has the center area | region 41 and the side areas 45 and 45 located in the both sides in the width direction Y, as shown to Fig.2 (a) and FIG.2 (b), The central region 41 has a protruding portion 5 that protrudes upward from the upper surfaces S2 and S2 of the lateral regions 45 and 45, respectively.
In the napkin 1, the protruding portion 5 of the absorbent core 4 exists under the top sheet 2 a, so that a raised portion 11 that protrudes toward the wearer's skin is formed at the center in the width direction of the skin contact surface. ing.
Further, the width W1 of the protrusion 5 [see FIG. 2 (a)] is preferably 20% or more, more preferably 30% or more, and preferably 80% or less, with respect to the total width W2 of the absorbent core. More preferably, it is 70% or less, preferably 20% or more and 80% or less, more preferably 30% or more and 70% or less.

The protrusion 5 of the absorbent core 4 and the raised portion 11 formed thereby in the napkin 1 have a long shape in the longitudinal direction of the absorbent core, as shown in FIG. It is formed from the part facing part B to a part of the rear part C. More specifically, it is formed in the range from the vicinity of the front end of the liquid excretion part facing part B to the vicinity of the central part in the X direction of the rear part C.
It is preferable that the protrusion part 5 and the protruding part 11 are formed from the liquid excretion part opposing part B to a part of the rear part C in the front-rear direction X of the napkin 1 (absorbent article). Moreover, it is preferable that the protrusion part 5 and the protruding part 11 are formed over the length of 30% or more of the total length of the napkin 1 in the front-rear direction X. More preferably, it is formed over 50% or more of the total length of the napkin 1. The same applies to the longitudinal grooves 50 and the high density portions 41a described later.

  Non-skin contact surface side formed by reducing the basis weight of the absorbent core forming material along the longitudinal direction X of the absorbent core 4 on the skin contact surface of the protruding portion 5 of the absorbent core 4 A vertical groove 50 having a bottom portion is formed. That is, the vertical groove 50 is not formed by compressing a part of the protruding portion 5 by embossing or the like, but a portion having a low basis weight of the absorbent core forming material is provided in a part of the protruding portion 5. Is formed. Moreover, the vertical groove 50 has the opening part 50a in the skin contact surface of the absorptive core 4, and the bottom part 50b in the non-skin contact surface side. In the napkin 1 shown in FIG. 1, the number of vertical grooves 50 provided in the protruding portion 5 is one, but the number of vertical grooves provided in the protruding portion is not limited to this, and is intermittent in the width direction Y. A plurality of them may be provided. In the napkin 1, the vertical groove 50 is arranged so as to cut the protrusion 5 along the longitudinal direction of the protrusion 5.

Further, the protruding portion 5 of the absorbent core 4 is formed with a lateral groove 44a having a bottom portion on the non-skin contact surface side, which is formed by reducing the basis weight of the forming material of the absorbent core 4 similarly to the longitudinal groove 50. Has been. The lateral groove 44 a extends along the width direction Y of the absorbent core 4.
In the napkin 1 shown in FIG. 1, a plurality of lateral grooves 44 a are intermittently provided in the protruding portion 5 in the longitudinal direction X. In the napkin 1, the lateral groove 44a is provided so as to cross the protruding portion 5 along the width direction of the protruding portion.

  In the central area 41 of the absorbent core 4, as shown in FIG. 2A, a high basis weight portion 42 and a low basis weight portion 43 that forms the bottom of the longitudinal groove 50 are formed in the width direction Y of the absorbent core 4. The low basis weight portions 43 extend along the longitudinal direction X of the absorbent core 4. The high basis weight part 42 is a part where the basis weight of the absorbent core forming material is relatively higher than the low basis weight part 43, and the low basis weight part 43 is the basis weight of the absorbent core forming material. Is a portion having a relatively low basis weight as compared with the high basis weight portion 42.

In the central area 41 of the absorbent core 4, the basis weight of the low basis weight portion 43 that forms the bottom of the longitudinal groove 50 is preferably 5% or more, more preferably 10%, relative to the basis weight of the high basis weight portion 42. In addition, it is preferably 50% or less, more preferably 40% or less, preferably 5% or more and 80% or less, and more preferably 10% or more and 70% or less. The basis weight of the high basis weight portion 42 is preferably 200 g / m ² or more, more preferably 300 g / m ² or more, and preferably 800 g / m ² or less, more preferably 700 g / m ² or less. In addition, it is preferably 200 g / m ² or more and 800 g / m ² or less, and more preferably 300 g / m ² or more and 700 g / m ² or less. The basis weight of the low basis weight portion 43 is preferably 10 g / m ² or more, more preferably 15 g / m ² or more, and preferably 400 g / m ² or less, more preferably 350 g / m ² or less. it is more preferably at 10 g / m ² or more 400 g / m ² or less and preferably, 25 g / m ² or more 300 g / m ² or less.

In the central area 41 of the absorbent core 4, the high basis weight portion 42 not only has a larger basis weight than the low basis weight portion 43 that forms the bottom of the longitudinal groove 50, but also has a larger thickness. The thickness of the low basis weight portion 43 is such that the ratio to the thickness of the high basis weight portion 42 is preferably 5% or more, more preferably 10% or more, and preferably 50% or less, more preferably 40% or less. In addition, it is preferably 5% or more and 50% or less, and more preferably 10% or more and 40% or less. The thickness of the high basis weight portion 42 is preferably 1.5 mm or more, more preferably 2 mm or more, preferably 10 mm or less, more preferably 8 mm or less, and 1.5 mm or more and 10 mm or less. It is preferable that it is 2 mm or more and 8 mm or less. The thickness of the low basis weight portion 43 is preferably 0.08 mm or more, more preferably 0.15 mm or more, preferably 5 mm or less, more preferably 4 mm or less, and 0.08 mm or more and 5 mm or less. It is preferable that it is 0.15 mm or more and 4 mm or less.
In addition, the value of the high basic weight part 42 mentioned above, and the various values in the relationship with the low basic weight part 43 are the case where the absorptive core is comprised including the horizontal groove 44a like the napkin 1 of this embodiment. May correspond to the high basis weight portion not including the lateral groove 44a.

[Measurement method of basis weight of high basis weight part and low basis weight part]
The absorbent core is cut along the boundary line between the high basis weight portion 42 and the low basis weight portion 43 using a single blade razor manufactured by Feather, and the high basis weight portion 42 and the low basis weight so as to have a predetermined area. A small piece of the quantity part 43 is obtained. The high basis weight portion 42 cuts out a portion sandwiched between the pair of low basis weight portions 43, 43 as a small piece. That is, the high basis weight part 42 is cut out as small block pieces partitioned by the low basis weight part 43. When the small piece includes the low basis weight portion 48 that forms the bottom of the lateral groove 44a extending in the width direction, the high basis weight defined by the boundary line between the high basis weight portion 42, the low basis weight portion 43, and the low basis weight portion 48. The quantity part 42 is cut out as a sample slice and used for measurement. The small piece of the low basic weight part 43 cuts out the narrow part pinched | interposed between a pair of high basic weight parts 42 and 42 as a small piece so that length may be set to 30 mm.
The weights of these pieces are measured using an electronic balance (Electronic balance GR-300 manufactured by A & D, accuracy: 4 digits after the decimal point). The calculated basis weight is calculated by dividing the obtained weight by the area of the small basis weight portion 42 or the low basis weight portion 43. About each of the high basic weight part 42 and the low basic weight part 43, let the average of the basic weight of five small pieces be a basic weight.

[Measurement method of thickness of high basis weight part and low basis weight part]
The measurement of the thickness of the high basic weight part 42 and the low basic weight part 43 is performed by measuring the thickness of the small piece cut out in order to measure a basic weight about each site | part. The measurement part of the small basic weight part 42 and the low basic weight part 43 cut out from the absorbent article is pressurized with a pressure of 5 kPa for 10 minutes, and the measurement is performed immediately after dewetting. An acrylic plate having a size of 20 mm × 20 mm and a thickness of 3 mm is placed on the absorber 3 in the central area of the sample after dewetting, and a non-contact type laser displacement meter (laser head LK-G30, displacement meter LK- manufactured by KEYENCE) Measure the thickness of the sample using the GD 500. If the size of the cut piece is small and difficult to measure with a non-contact type laser displacement meter, the cross section of the cut sample is, for example, a microscope (Keyence Corporation). It may be observed and measured at a magnification of 20 to 100 times using VHX-1000).

  In the central area 41 of the absorbent core 4, the high basis weight portion 42 has a higher density of the absorbent member than the low basis weight portion 43 that forms the bottom of the longitudinal groove 50. Such a configuration is obtained, for example, by pressing the central region 41 of the absorbent core 4 in the process of manufacturing the absorbent core 4. Under the present circumstances, the pressure by a press concentrates on the thick high basic weight part 42, and the thin low basic weight part 43 does not receive a pressure by a press and is not compressed. In this way, the high basis weight portion 42 is designed so that the density of the absorbent member is increased with respect to the low basis weight portion 43 by compressing only the high basis weight portion 42. In the central area 41 of the absorbent core 4, high basis weight portions 42 and low basis weight portions 48 that form the bottom of the lateral grooves 44 a are alternately formed in the longitudinal direction X of the absorbent core 4. The high basis weight portion 42 has a higher density of the absorbent member in comparison with the low basis weight portion 48 that forms the bottom of the lateral groove 44a. In addition, a density is calculated by using the basic weight and thickness obtained based on the measuring method mentioned above.

  On the other hand, also in the side area 45 of the absorbent core 4, the high basis weight portion 46 has a higher density of the absorbent member than the low basis weight portion 47 that forms the bottom of the longitudinal groove 52. Such a configuration can be obtained as follows. The lateral region 45 of the absorbent core 4 is pressed in a step different from the step of pressing the central region 41. The pressure by the press is concentrated on the thick high basis weight portion 46, and the low low basis weight portion 47 is not compressed by the press and is not compressed. Thus, the high basis weight part 46 is designed so that the density of the absorbent member is increased with respect to the low basis weight part 47 by compressing only the high basis weight part 46. In addition, the press process used in this process is a measure such as using a press roll cut into a shape corresponding to the central area 41 or a roll having a press portion only in a part corresponding to the side area 45 of the absorbent core 4. It is devised so that only the side region of the absorbent core 4 is pressed.

  And the high basic weight part 42 and the low basic weight part 43 which have a basic weight difference and a density difference are formed in said aspect, By the skin contact surface in the center area 41 of the absorptive core 4, Longitudinal grooves 50 that are recessed toward the non-skin contact surface are formed so as to extend in the width direction Y of the absorbent core 4. In the present specification, the skin contact surface is a surface directed toward the wearer's skin when worn on the absorbent article or its constituent member, and the non-skin contact surface is when worn on the absorbent article or its constituent member. It is a surface directed to the side opposite to the wearer's skin side.

Further, in the side area 45 of the absorbent core 4, as shown in FIG. 2A, high basis weight portions 46 and low basis weight portions 47 are alternately formed in the width direction Y of the absorbent core 4. The individual low basis weight portions 47 extend along the longitudinal direction X of the absorbent core 4. The high basis weight portion 46 has a relatively high basis weight of the absorbent core forming material as compared to the low basis weight portion 47, and the low basis weight portion 47 has a high basis weight of the absorbent core forming material. The basis weight is relatively low as compared with the amount portion 46.
And the high basic weight part 46 and the low basic weight part 47 which have a basic weight difference and a density difference are formed in said aspect in the skin contact surface in the side area 45 of the absorptive core 4. FIG. Also, a plurality of side longitudinal grooves 52 that are recessed toward the non-skin contact surface side are formed extending in the longitudinal direction X of the absorbent core 4.

In the side area 45 of the absorbent core 4, the basis weight of the low basis weight portion 47 that forms the bottom of the side longitudinal groove 52 is preferably a ratio of 5% or more, more preferably, to the basis weight of the high basis weight portion 46. Is 10% or more, preferably 50% or less, more preferably 40% or less, preferably 5% or more and 50% or less, more preferably 10% or more and 40% or less. . The basis weight of the high basis weight portion 46 is preferably 50 g / m ² or more, more preferably 100 g / m ² or more, and preferably 400 g / m ² or less, more preferably 300 g / m ² or less. In addition, it is preferably 50 g / m ² or more and 400 g / m ² or less, and more preferably 100 g / m ² or more and 300 g / m ² or less. The basis weight of the low basis weight portion 47 is preferably 2.5 g / m ² or more, more preferably 5 g / m ² or more, and preferably 200 g / m ² or less, more preferably 150 g / m ² or less. In addition, it is preferably 2.5 g / m ² or more and 200 g / m ² or less, and more preferably 5 g / m ² or more and 150 g / m ² or less.

In the side area 45 of the absorbent core 4, the high basis weight portion 46 not only has a larger basis weight than the low basis weight portion 47 that forms the bottom of the side longitudinal groove 52, but also has a larger thickness. The thickness of the low basis weight portion 47 is such that the ratio to the thickness of the high basis weight portion 46 is preferably 5% or more, more preferably 10% or more, and preferably 50% or less, more preferably 40% or less. In addition, it is preferably 5% or more and 50% or less, and more preferably 10% or more and 40% or less. The thickness of the high basis weight portion 46 is preferably 0.8 mm or more, more preferably 1 mm or more, preferably 5 mm or less, more preferably 4 mm or less, and 0.8 mm or more and 5 mm or less. It is preferable that it is 1 mm or more and 4 mm or less. The thickness of the low basis weight portion 47 is preferably 0.04 mm or more, more preferably 0.08 mm or more, preferably 0.4 mm or less, more preferably 0.32 mm or less, and 0.04 mm. It is preferably 0.4 mm or less and more preferably 0.08 mm or more and 0.32 mm or less.
In addition, the value in the relationship with the high basic weight part 46 mentioned above and the low basic weight part 47 is the case where the absorptive core is comprised including the horizontal groove 44b like the napkin 1 of this embodiment. May correspond to a high basis weight part not including the lateral groove 44b.

  In addition, the measuring method of the basic weight and thickness in each of the high basic weight part 46 and the low basic weight part 47 is performed similarly to the measuring method in the high basic weight part 42 and the low basic weight part 43 mentioned above.

Further, the high basis weight portion 42 of the central area 41 has a larger basis weight than the high basis weight portion 46 of the side area 45, and the thickness is also larger than the high basis weight section 46 of the side area 45. It has become. As a result, the thickness t1 of the central region 41 becomes thicker than the thickness t2 of the side region 45, and the protruding portion 5 that protrudes above the upper surface S2 of the side region 45 is formed in the central region 41.
The ratio of the thickness t1 of the central region 41 to the thickness t2 of the side region 45 is preferably 110% or more, more preferably 120% or more, and preferably 400% or less, more preferably 300% or less. Also, it is preferably 110% or more and 400% or less, and more preferably 120% or more and 300% or less. In the present embodiment, the thickness t1 of the central region 41 is the thickness of the high basis weight portion 42 located in the central portion in the width direction of the central region 41, and the thickness t2 of the side region 45 is adjacent to the central region 41. This is the thickness of the high basis weight portion 46.
In the protruding portion 5, the ratio of the height t protruding from the upper surface S <b> 2 of the lateral region 45 to the total thickness t <b> 1 of the central region 41 is preferably 20% in both the liquid excretion portion facing portion B and the rear portion C. Or more, more preferably 30% or more, preferably 90% or less, more preferably 80% or less, preferably 20% or more and 90% or less, more preferably 30% or more and 80% or less. It is. The protrusion height t of the protrusion 5 is the same as the value obtained by subtracting the thickness t2 of the side area 45 from the total thickness t1 of the central area 41.

In the napkin 1, the high basis weight portions 46 and the low basis weight portions 49 are also alternately formed in the longitudinal direction X of the absorbent core 4 in the lateral region 45, and the individual low basis weight portions 49 are It extends along the width direction Y of the absorbent core 4. As a result, a plurality of lateral grooves 44 b are intermittently arranged in the lateral region 45 in the longitudinal direction X. The position in the longitudinal direction X of the absorptive core 4 matches the low basic weight part 48 of the central area 41 and the low basic weight part 49 of the lateral area 45 at the boundary part between the central area 41 and the lateral area 45. Similarly, the lateral groove 44a in the central region 41 and the lateral groove 44b in the lateral regions 45, 45 coincide with each other in the longitudinal direction X of the absorbent core 4 at the boundary portion.
That is, the lateral groove 44a in the central region 41 and the lateral groove 44b in the lateral regions 45, 45 form one lateral groove 44 that continues from the central region 41 to the lateral regions 45, 45 of the absorbent core 4. The lateral groove 44 extends over the entire width of the absorbent core 4. A plurality of the lateral grooves 44 are formed at intervals in the longitudinal direction of the absorbent core 4. In other words, the low basis weight portion 43 in the central region 41 and the low basis weight portion 47 in the side region 45 form a single low basis weight portion that extends continuously over the entire width of the absorbent core 4. The single low basis weight part is smaller in the basis weight, thickness and density of the absorbent core forming material than the high basis weight part 46 in the side region 45.
Concerning the lateral groove 44, continuous from the central area to the lateral area means that the space in the lateral groove whose upper side is released extends from the central area to the lateral area without being interrupted between the central area and the lateral area. That exist continuously. In the napkin 1 of the present embodiment, the horizontal groove 44 intersects the vertical groove 50 in a cross shape in plan view, but the other horizontal groove is on the extension of the space in the horizontal groove on one side facing the vertical groove. When all or part of the inner space is present, the transverse groove is not interrupted at the intersection with the longitudinal groove.

  In the napkin 1 of the present embodiment, the absorbent core 4 has the front central region 41 and the side regions 45 formed integrally, and is located on the inner side in the width direction on both sides in the width direction of the central region 41. It has a high density portion 41 a having a higher density than the protruding portion 5 and a higher basis weight than the side region 45. In the napkin 1 of the present embodiment, the high density portion 41a has the same thickness as the portion 42 ′ that becomes the high basis weight portion 42 in the central region 41 of the absorbent core 4 when the napkin is manufactured, as shown in FIG. It is formed by compressing both sides in the width direction. Further, in the napkin 1, the longitudinal groove 50 of the protruding portion 5 has a width in the width direction of the bottom 50b that is narrower than the opening 50a. As shown in FIG. 2A, the longitudinal groove 50 is substantially V-shaped in a cross-sectional view in the width direction. By having such a configuration in the central area 41, the following characteristic effects of the present invention can be achieved.

  First, the body fluid is discharged to the protruding portion 5 in the central area 41 at the excretory portion facing portion B. The excrement is easily diffused in the longitudinal direction X by the longitudinal grooves 50 extending in the longitudinal direction X. On the other hand, since the vertical groove 50 has a shape in which the opening 50a is wide and the bottom 50b is narrow in the width direction Y, the body fluid that has entered the vertical groove 50 comes into contact with the side wall 50c of the vertical groove 50 while the bottom 50b. It flows in the direction of. Therefore, the body fluid is absorbed from the side wall 50c before reaching the bottom 50b, and diffuses in the width direction Y of the protrusion 5 and enters the thickness direction. On the side of the central region 41, there is a high density portion 41a formed by compressing the protruding portion 5. For this reason, the body fluid which has spread in the width direction Y and the thickness direction is guided to the high density portion. Since the high-density portion has a higher basis weight of the absorbent material than the side region 45, the ability to hold body fluid is high. Therefore, the bodily fluid is dammed at both sides of the central area 41 and hardly reaches the both sides in the width direction of the napkin 1. For this reason, in the napkin 1, the side leakage of body fluid is easily suppressed. In addition, in the napkin 1 of this embodiment, since the high density part 41a has substantially the same thickness as the high basic weight part 52 in the side area 45, the width | variety of the protrusion part 5 fits a wearer's excretion part. It is easy to provide a high-absorption region that does not give a sense of incongruity while having a shape. However, the present invention is not limited to this, and the thickness of the high-density portion 41 a is smaller than the thickness of the protruding portion 5 and thicker than the high basis weight portion 52 in the side region 45, or the side region 45. Inclination from the protruding portion 5 to the side region 45 is provided by providing an inclination so that the thickness gradually decreases from the protruding portion 5 toward the side region 45 so as to be the same as the height of the high basis weight portion 52. An area can be provided to give a soft appearance.

In the present specification, “integrated molding” means that one member is manufactured using the same material, but different from members manufactured in separate steps by bonding means such as an adhesive or compression. It means that it is integrally formed. Therefore, for example, between the portion 42u forming the protruding portion 5 in the central region 41 and the portion 42d located below the portion 42u, there are layers of layers that are produced when two separately manufactured absorbent cores are stacked. There are no adjacent portions or joint portions, and adjacent portions between cores generated when two separately manufactured absorbent cores are arranged side by side at the boundary portion between the central region 41 and the side regions 45, 45. There is no joint.
When the central region 41 including the protruding portion 5 and the pair of side regions 45, 45 are integrally formed, the liquid to be absorbed has continuity that can move smoothly. A method for manufacturing the absorbent core having such a structure will be described later.

The high density part 41a will be described more specifically.
The high-density part 41a in the napkin 1 is a center formed thickly including the part to become the high-density part 41a as shown in FIG. After the absorbent core 4A having the region 41 is manufactured, both sides of the central region 41 of the absorbent core 4A are compressed and formed. In the napkin 1, the thickness is reduced by compressing certain portions of the left and right side portions of the projecting portion 5 in the central region 51, and the portion has a higher density than the uncompressed projecting portion 5. A density portion 41a is formed. Moreover, since the high-density part 41a has sufficient absorption capacity since the basic weight of an absorbent material is higher than the side region 45, since it has sufficient absorption capacity, a bodily fluid reaches | attains the side edge of the absorptive core 4. Suppress. Therefore, it becomes easy to prevent body fluid from leaking from the side of the napkin 1. In the napkin 1 of the present embodiment, the high-density region 41a has substantially the same thickness as the portion of the side region 45 where the vertical groove 50 and the horizontal groove 44 do not exist. Although the thickness is thinner, the thickness may be thicker than the side region 45.

  Further, in the napkin 1, as shown in FIG. 2 (a), the longitudinal groove 50 of the protruding portion 5 gradually decreases in length in the width direction from the opening 50a toward the bottom 50b, and is seen in a cross-sectional view in the width direction. Then, the vertical groove 50 is substantially V-shaped. In addition to such a form, a step-like cross-sectional shape may be used, but the substantially V-shaped can more efficiently contact the wall surface 50c before the body fluid reaches the bottom surface 50b from the opening 50a of the longitudinal groove 50, Since the gap is gradually narrowed, the capillary force acts from the longitudinal groove opening 50a to the bottom 50b, and the liquid can be taken into the absorbent core 4 more quickly. This is preferable because it can be easily taken into the absorbent core 4 from the contact surface side.

The longitudinal groove 50 of the protrusion 5 has a width direction length La of the opening 50a of preferably 0.5 mm or more, more preferably 1 mm or more, and preferably 5 mm or less, more preferably 4 mm. The width direction length Lb of the bottom 50b is preferably 1 mm or less, and more preferably 0.5 mm or less. The lower limit of the width direction length Lb of the bottom 50b is 0 (zero).
Moreover, the depth of the vertical groove 50 is preferably 0.5 mm or greater and 5.0 mm or less, and more preferably 1.0 mm or greater and 3.0 mm or less. Further, in the longitudinal groove 50, the difference in length in the width direction between the opening 50a and the bottom 50b (the La-the Lb) is preferably 0.5 mm or more and 3.0 mm or less, more preferably 1.0 mm or more and 2 0.0 mm or less.
In addition, the longitudinal groove 50 preferably has a depth ratio [depth / difference (La−Lb)] to a difference in length in the width direction between the opening 50a and the bottom 50b (La−Lb). 5 or more and 20 or less, more preferably 1 or more and 10 or less. Within this range, the shape of the longitudinal groove during wearing is easily stabilized, and it becomes easy to maintain a preferable shape for taking in excreta.

  Further, the bottom 50 b of the vertical groove 50 is located below the upper surface S <b> 2 of the side region 45. The position of the upper surface S <b> 2 of the side region 45 here is the upper surface of the high basis weight portion 46 in the side region 45 adjacent to the central region 41. The bottom 50b of the longitudinal groove 50 is preferably located below the upper surface S2 of the lateral region 45 over the entire region of the central region 41 in the longitudinal direction X of the absorbent core 4. By adopting such a configuration, the liquid is quickly transferred from the surface of the napkin 1 to the deep inside of the absorbent core 4, and the liquid is transferred from the inside of the absorbent core 4 toward the side edge of the absorbent core 4. It becomes possible to diffuse. In this way, once the liquid is taken into the absorbent core 4 from the surface of the napkin 1, the liquid is diffused inside the absorbent core 4, thereby suppressing the diffusion of the liquid on the surface of the napkin 1 and the back surface of the napkin 1. It becomes possible to diffuse the liquid. For this reason, the wetted part of the napkin 1 surface due to the liquid can be reduced to provide a comfortable dry feeling to the user, and the liquid can be easily transmitted to the side area 45 of the absorbent core 4. Since it is possible to utilize the absorption capacity of the core 4 more efficiently, it is possible to provide a product that does not leak even when used for a long time. In addition, since the liquid diffusion on the napkin 1 surface is suppressed, the difference in liquid diffusibility between the napkin 1 surface and the back surface of the napkin 1 becomes large. From this difference, the user can visually recognize the high absorbability of the napkin 1. It is also possible to appeal. In the present napkin 1, the low basis weight portion 43 in the central region 41 has a smaller basis weight and thickness than the high basis weight portion 46 in the side region 45, whereby the longitudinal groove 50 and the lateral groove 44 are absorbent. The bottom portion is located below the upper surface S <b> 2 of the side region 45 across the entire central region 41 in the longitudinal direction X and the width direction Y of the core 4.

  Further, in the napkin 1 of the present embodiment, the plurality of the lateral grooves 44 are portions P1, P1 adjacent to the side region 45 of the central region 41 in the width direction Y of the absorbent core 4 [FIG. 2 (b). 44d is located below the upper surface S2 of the side area 45. As shown in FIG. 2B, the bottom 44 d of the lateral groove 44 is located below the upper surface S <b> 2 of the side region 45 over the entire region of the central region 41 in the width direction of the absorbent core 4. It is preferable. In the present napkin 1, the low basis weight portion 43 in the central region 41 has a smaller basis weight and thickness than the high basis weight portion 46 in the side region 45, whereby the longitudinal groove 50 and the lateral groove 44 are absorbent. The bottom portion is located below the upper surface S <b> 2 of the side region 45 across the entire central region 41 in the longitudinal direction X and the width direction Y of the core 4.

  Whether the bottoms of the vertical grooves 50 and the horizontal grooves 44 are positioned below the position of the upper surface S2 of the side area 45 depends on the thickness of the bottom 44 in the parts P1, P1 adjacent to the side area 45 of the central area 41, And it judges by measuring the thickness of the high basic weight part 46 of the side area 45. FIG. Specifically, first, the absorbent core 4 is taken out from the napkin 1, and the thickness of the high basis weight portion 46 in the side region 45 is measured with the bottom surface of the central region 41 as a base point. Thickness is measured by pressurizing each part for 10 minutes at a pressure of 5 kPa, placing an acrylic plate with a size of 20 mm x 20 mm and thickness 3 mm on the measurement part after dewetting, and a non-contact type laser displacement meter (laser head) manufactured by KEYENCE. LK-G30 and displacement meter LK-GD 500. Next, measurement of the bottoms at the sites P1 and P1 adjacent to the side region 45 of the central region 41 using a feather blade made from an absorbent article. Cut out the part, pressurize it at a pressure of 5 kPa for 10 minutes, and measure the thickness immediately after dewetting.In the central area of the sample after dewetting, place an acrylic plate of size 20 mm × 20 mm and thickness 3 mm on the absorber 3. The sample thickness is measured using a non-contact type laser displacement meter (Laser Head LK-G30, Displacement Meter LK-GD500, manufactured by KEYENCE). When the size of the cut piece is small and difficult to measure with a non-contact type laser displacement meter, the cross section of the cut sample is 20 to 100 times using, for example, a microscope (VHX-1000 manufactured by KEYENCE). It is possible to observe and measure at a magnification of 1. The thickness of the high basis weight portion 46 of the side area 45 obtained previously, and the measurement part at the bottom in the parts P1, P1 adjacent to the side area 45 of the central area 41 If the thickness of the vertical groove 50 is large, it is determined that the bottoms of the vertical groove 50 and the horizontal groove 44 are located below the position of the upper surface S2 of the side region 45.

  In addition, the absorbent core 4 has a concavo-convex shape on the skin contact surface due to the presence of the lateral groove and the vertical groove in both the central region 41 and the side region 45, while the non-skin contact surface side is flat. ing.

According to the napkin 1 of the present embodiment, the central region 42 having the protrusions 5 has a deep depth, the bottom 44d reaches a position deeper than the upper surface S2 of the lateral region 45, and from the central region 42 to the lateral region 45. The lateral groove 44 is also formed, and the lateral groove 44 is formed by reducing the basis weight of the material for forming the absorbent core. Nevertheless, it is rich in deformability and hardly causes wrinkles on the skin contact surface. Therefore, as shown in FIG. 4, the entire shape is made to conform to the wearer's body shape while keeping the protruding portion 5 and the raised portion 11 formed thereby along the wearer's liquid excretion portion or tear. It can be deformed and has excellent fit with respect to the unevenness of the body, is excellent in follow-up deformability with respect to the movement of the wearer, and does not easily give a sense of incongruity due to wrinkles or breakage of the absorbent core.
Such an effect is further enhanced when the bottom 44 d of the lateral groove 44 is positioned below the upper surface S <b> 2 of the side region 45 over the entire region of the central region 41 in the width direction Y of the absorbent core 4. .

  Moreover, since the absorbent core is integrally formed and the lateral groove 44 is formed by reducing the basis weight of the material for forming the absorbent core, the liquid absorbed from the protruding portion 5 has a thickness in the central region 41. In addition to the smooth diffusion in the direction, the liquid easily diffuses from the vicinity of the bottom of the lateral groove 44 to other parts, and the liquid staying in the vicinity of the bottom of the lateral groove 44 does not return to the skin contact surface by pressurization. Therefore, even when a large amount of liquid is supplied, the liquid hardly remains on the skin contact surface, and a comfortable wearing feeling can be obtained.

  From the viewpoint of ensuring such an effect, the ratio of the depth of the lateral groove 44a (44) in the central area 41 to the thickness t1 of the central area 41 is preferably 50% or more. Preferably it is 60% or more, preferably 95% or less, more preferably 90% or less, preferably 50% or more and 95% or less, and preferably 60% or more and 90% or less. Is more preferable.

  Further, the width W of the lateral groove 44 is preferably 0.2 mm or more, more preferably 0.5 mm or more, preferably 3 mm or less, more preferably 2 mm or less, and 0.2 mm or more and 3 mm or less. It is preferable that it is 0.5 mm or more and 2 mm or less. The width W of the lateral groove 44 is a dimension in the longitudinal direction X of the absorbent core as shown in FIG.

  Further, in the napkin 1, since the high basis weight portion 42 in the central area 41 has a higher density than the low basis weight portion 43, body fluid taken into the lateral groove 44 is quickly taken into the high basis weight portion 42. It has become. For this reason, the body fluid is absorbed in the longitudinal direction of the absorbent core 4 while being transmitted through the lateral groove 44, so that the body fluid is efficiently absorbed in the central region. As a result, the suppression of liquid leakage from the absorbent core 4 is improved. In addition, since the high basis weight portion 46 has a higher density than the low basis weight portion 47 in the side region 45, the same effect can be obtained.

  In each of the central area 41 and the lateral area 45, the density of the low basis weight part is preferably 5% or more, more preferably 10% or more, and preferably the ratio to the density of the adjacent high basis weight part. It is 50% or less, more preferably 40% or less, preferably 5% or more and 50% or less, more preferably 10% or more and 40% or less.

  Moreover, in the napkin 1, the several compression part compressed so that it might become united toward the absorptive core 4 from the surface sheet 2a side in the center area 41 is provided. And the surface sheet 2a is indented in the vertical groove 50 in the part which a compression part overlaps with the vertical groove 50 of the center area 41. FIG. For this reason, it becomes difficult for the surface sheet 2a to float during wearing, and twisting is less likely to occur. In addition, it becomes easy for body fluid to enter the absorbent core 4 from the compression portion, and it is easy to prevent inconvenience that the body fluid travels on the top sheet 2a and causes side leakage. Such an effect is particularly effective in the case of a highly viscous body fluid such as menstrual blood. For example, as shown in FIG. 6, the compression part is formed by stacking the surface sheet 2 a on the skin contact surface side of the absorbent core 4 and pressing the surface sheet 2 a and the absorbent core 4 from the surface sheet 2 a side. Is done. The pressing is performed by, for example, pressing a portion indicated by reference numeral 61 in FIG. 6A with the embossing convex portion 6 provided on the peripheral surface of the roll.

  Further, in the napkin 1, side longitudinal grooves 52 extending in the longitudinal direction are also provided in the side region 45. In the lateral longitudinal groove 52, the opening 52a located on the skin contact surface side and the bottom 52b located on the non-skin side surface side have substantially the same length in the width direction. Here, “substantially the same” means that the difference in width direction length between the opening and the bottom at the same position in the longitudinal direction is within 5%. With such a configuration, the compressive force received from the user's foot during wearing of the napkin 1 is uniformly transmitted to the lateral longitudinal grooves 52 and the lateral longitudinal grooves 52 are evenly compressed, so that the user receives from the napkin 1. It is possible to relieve the reaction of the compressive force and eliminate the uncomfortable feeling that the user feels while wearing the napkin 1. If the opening 52a of the lateral longitudinal groove 52 is made wider than the bottom 52b, the opening is more greatly deformed by the compressive force that the napkin 1 receives from the lower part of the user's foot during wearing. One side edge portion may be deformed so as to be rounded toward the user. Such deformation is caused by the napkin 1 side edge warping toward the user's skin side, so that the napkin 1 hits the buttocks strongly, or the user's skin and the surface of the napkin 1 are separated from each other at the center of the napkin 1. May occur. However, by making the opening 52a and the bottom 52b have substantially the same length in the width direction, the risk of occurrence of such a problem can be reduced. Moreover, it is useful for the stability of the shape of the longitudinal groove 50 in the central region 41 in the present invention.

  The lateral longitudinal grooves 52 are preferably adjacent to the high density portion. With such a configuration, the absorbent core 4 in contact with the lateral side of the lateral longitudinal groove 52 and the absorbent core 4 in contact with the central side of the lateral longitudinal groove 52 are different in hardness. It becomes easy to bend the side edge part in the direction opposite to the user's skin with the longitudinal groove 52 as a basic axis, and by making the shape of the napkin 1 being worn more stable, the user feels uncomfortable feeling by wearing the napkin 1 In addition to the reduction, the central part of the napkin 1 is more closely attached to the user's skin, and the liquid can be absorbed more efficiently. Further, by adjoining the high-density portion that plays a role of sucking and capturing the liquid and the lateral vertical groove 52 having a relatively low density, the liquid is prevented from exuding to the side of the high-density portion, and more The liquid is fixed in an area close to the central area of the napkin 1, and there is an effect that liquid leakage from the side edge of the napkin 1 is prevented.

It is preferable that the bottom surface 50b of the longitudinal groove 50 in the central region 41 is located on the non-skin contact surface side than the bottom surface 52b of the lateral longitudinal groove 52. With such a configuration, first, the side portion of the napkin 1 is bent in the direction opposite to the user's skin, with the vertical groove 50 whose bottom surface is located on the non-skin contact surface side as a basic axis, and then the bottom surface is applied to the skin. The side part of the napkin 1 is bent more in the direction opposite to the user's skin with the side vertical groove 52 located on the contact surface side as a basic axis, and the shape of the napkin 1 being worn can be made more stable. It becomes possible.

The absorptive core 4 of the napkin 1 described above is provided with the accumulation recess 55 on the outer peripheral surface, and the stacking drum 54 that rotates in one direction R, and the absorbent core forming material is scattered on the outer peripheral surface of the stacking drum 54. It can manufacture by performing the process as shown in FIG. 3, after manufacturing the absorptive core 4A mentioned above using the fiber pile apparatus provided with the duct (not shown) supplied in a state.
A plurality of stacking recesses 55 are formed at regular intervals in the circumferential direction of the outer peripheral surface of the stacking drum 54. The bottom surface 56 of the accumulation recess 55 is made of a mesh plate or the like and has a large number of pores functioning as suction holes.

As shown in FIG. 5, a concave portion 56 a for forming the central region 41 having the protruding portion 5 is formed on a part of the bottom surface 56 of the accumulation concave portion 55. A breathable member 56 for forming low basis weight portions such as the low basis weight portions 43, 43 is disposed at the bottom of the accumulation recess 55. The air-impermeable member 56 is fixed so as to protrude from the bottom surface of the accumulation recess 55, and may be a non-air-permeable member, for example, made of metal or plastic.
As shown in FIG. 5 (b), the material for forming the absorbent core is supplied into the duct while sucking from the bottom surface of the accumulation recess 55, as in the known fiber stacking device including the fiber stacking drum. The material for forming the absorbent core is deposited in a predetermined shape in the accumulation recess 55. The absorbent core 4A is obtained by releasing the deposit 4 'from the accumulation recess 55. The absorbent core 4A may be pressed and compressed appropriately by passing between a pair of rolls before or after coating with the core wrap sheet. As shown in FIG. 5 (b), the portion 43 ′ made of the core forming material deposited on the breathable member 56 becomes the low basis weight portion 43 or the like, and the portion deposited on the bottom surface without the breathable member 56. 42 'becomes the high basic weight part 42 grade | etc.,. Further, as described above, by pressing the central area 41 of the absorbent core 4 </ b> A, the high basic weight part 42 having a higher density than the low basic weight part 43 is formed in the central area 41 and becomes the central area 41. Separately from the portion, by pressing the side region 45, the high basis weight portion 46 having a higher density than the low basis weight portion 47 is formed in the side region 45. Moreover, the press (compression) which forms the high basic weight part 41a in the center area 41 of the absorptive core 4A can also be performed before or after coating with the core wrap sheet. The press (compression) for forming the high basis weight portion 41a may be performed simultaneously with the pressing of the central region 41 or the pressing of the lateral region 45 using a roll having a step on the peripheral surface. Moreover, it is also possible to carry out simultaneously with the pressing of the central area 41 and the pressing of the side area 45 by designing the level difference formed on the roll peripheral surface to an appropriate dimension. Further, it can be performed in a separate process from the pressing of the central area 41 and the pressing of the lateral area 45, before the pressing of the central area 41, between the pressing of the central area 41 and the pressing of the lateral area 45, You may perform in the process different from those presses after the side area 45 press.
When manufacturing the absorptive core containing a water absorbing polymer, it is preferable to provide the introduction part of a water absorbing polymer in the middle of a duct.

  As the surface sheet 2a and the non-skin side sheet 3, those similar to those conventionally used in the technical field can be used without particular limitation. For example, as the top sheet 2a, a liquid-permeable nonwoven fabric or a perforated film can be used. As the non-skin side sheet 3, a water-repellent nonwoven fabric having a high water pressure resistance such as a liquid-impermeable film made of a synthetic resin or a spunbond-meltblown-spunbond laminated nonwoven fabric can be used. Further, as the three-dimensional guard forming sheet 2b, a water-repellent nonwoven fabric having a high water pressure resistance, such as a spunbond-meltblown-spunbond laminated nonwoven fabric, or the like can be used.

As mentioned above, although this invention was demonstrated based on the preferable embodiment, this invention is not restrict | limited to the said embodiment.
For example, the lateral groove 44 extending from the central area 41 to the lateral area 45 may be formed only in the liquid excretion part facing part of the absorbent article, or may be formed only in the rear part.

  Moreover, an absorptive core may consist only of fiber materials, such as a pulp fiber, and may contain both a fiber material and a super absorbent polymer. As the fiber material, various materials conventionally used for absorbent articles of absorbent articles such as sanitary napkins, panty liners, disposable diapers and the like can be used without particular limitation. For example, pulp fibers, rayon fibers, cotton Short fibers of cellulosic fibers such as fibers, short fibers of synthetic fibers such as polyethylene, and the like are used. These fibers can be used alone or in combination of two or more. Moreover, it is preferable that the fiber material is entirely or partly pulp fiber, and the ratio of the pulp fiber in the fiber material is preferably 50 to 100% by mass, more preferably 80 to 100% by mass, More preferably, it is 100 mass%. In addition to the superabsorbent polymer, the absorbent core may contain a deodorant or an antibacterial agent as necessary.

In the above-described embodiment, the density of the high basis weight portion is higher than that of the low basis weight portion. However, the density of both may be the same by omitting the pressing step of the absorbent core.
Further, in addition to or instead of causing the vertical sheet 50 formed in the central area 41 to indent the topsheet 2a by the pressing section 61 (compression section), the lateral groove 44a formed in the central area 41 has a pressing section. The top sheet 2a may be indented.

  In addition to the sanitary napkin, the absorbent article of the present invention may be other absorbent articles such as panty liners (origami sheets), incontinence pads, and disposable diapers. The description omitted in one embodiment described above and the requirements of only one embodiment can be applied to other embodiments as appropriate, and the requirements in each embodiment can be appropriately changed between the embodiments. Can be replaced with

This invention discloses the following absorbent articles further regarding embodiment mentioned above.
<1> An absorbent article provided with an absorbent core having a long shape in the front-rear direction of the absorbent article,
The absorbent core has, in the width direction, a central region and lateral regions located on both sides thereof, and the central region has a protruding portion that protrudes upward from the upper surface of each of the lateral regions. In the absorbent core, the central area and the side area are integrally formed, and both sides of the central area in the width direction are higher in density than the protrusions, and have a smaller area than the side area. A high-density portion having a high amount is formed, and the skin contact surface of the protruding portion is formed by reducing the basis weight of the absorbent core forming material along the longitudinal direction of the absorbent core. An absorbent article, wherein a longitudinal groove having a bottom portion is formed on the skin contact surface side, and the longitudinal groove has a width direction length of the bottom portion narrower than an opening portion.
<2> The absorbent article according to <1>, wherein the longitudinal groove is gradually narrowed in the width direction from the opening toward the bottom.
<3> The absorbent article according to <1> or <2>, wherein a lateral groove extending in a width direction of the absorbent core is formed in the protruding portion.
<4> The absorbent article according to <3>, wherein a plurality of the lateral grooves are intermittently arranged in the longitudinal direction.
<5> The absorbent article according to any one of <1> to <4>, wherein the vertical groove cuts the protruding portion in a vertical direction.
<6> A liquid-permeable surface sheet is disposed on the skin contact surface side of the absorbent core, and a pressing portion in which the surface sheet and the absorbent core are pressed together is provided in the central region. The absorbent article according to any one of <1> to <5>, wherein the top sheet is indented at the pressing portion in the longitudinal groove or the lateral groove. <7> The absorbent core A lateral longitudinal groove extending in the longitudinal direction is disposed on the skin contact surface side of the lateral region of the lateral region, and the lateral longitudinal groove has substantially the same width direction length of the opening and the bottom, <1 The absorbent article according to any one of> to <6>.
<8> The absorbent article according to any one of <1> to <7>, wherein the high-density portion is in contact with the lateral longitudinal groove.
<9> In any one of the above items <1> to <8>, wherein a bottom portion of the longitudinal groove in a portion adjacent to the lateral region of the central region is positioned below the upper surface of the lateral region. The absorbent article as described.
<10> Any one of the items <1> to <9>, wherein a bottom portion of the longitudinal groove in a portion adjacent to the lateral region of the central region is positioned below a bottom surface of the lateral longitudinal groove. Absorbent article as described in 1.

<11> The <3> to <10>, wherein the lateral groove has a bottom portion on the non-skin surface side, and the bottom portion is located on the non-skin contact surface side with respect to the top surface of the side region. The absorbent article as described in any one.
<12> The absorbent article according to any one of <1> to <11>, wherein the width of the protruding portion is 20% or more and 80% or less of the total width of the absorbent core.
<13> The absorbent article according to any one of <1> to <12>, wherein the protrusion is formed over a length of 30% or more of a total length in the front-rear direction of the absorbent article.
<14> The absorbent article according to any one of <1> to <13>, wherein the high basis weight portion has a higher density of the absorbent member than the low basis weight portion in the central region of the absorbent core.
<15> In the central region, the basis weight of the low basis weight part forming the bottom of the vertical groove is such that the ratio of the high basis weight part to the basis weight is 5% or more and 80% or less <1> to <12>. The absorbent article as described in any one of these.
<16> The absorbent article according to <15>, wherein in the central region, the thickness of the low basis weight part is 5% or more and 50% or less with respect to the thickness of the high basis weight part.
<17> The absorbent article according to any one of <1> to <16>, wherein the thickness of the central region is 110% or more and 400% or less with respect to the thickness of the side region.
<18> The lateral groove in the central region and the lateral groove in the lateral region form one lateral groove that extends from the central region to the lateral region of the absorbent core, and the lateral groove is the full width of the absorbent core. The absorbent article as described in any one of said <3>-<17> extended over.
<19> The absorbent article according to any one of <1> to <18>, wherein a gap exists between the longitudinal groove and the top sheet in the lateral region.
<20> The absorbent article according to any one of <1> to <19>, in which, in the central region, in the lateral groove, the topsheet is indented at the pressing portion.

<21> The longitudinal groove La of the projecting portion has a width direction length La of preferably 0.5 mm or more, more preferably 1 mm or more, and preferably 5 mm or less, more preferably 4 mm or less. The absorbent article according to any one of <1> to <20>.
<22> The vertical groove of the protruding portion has a width direction length Lb of the bottom portion of preferably 1 mm or less, more preferably 0.5 mm or less, and the lower limit is 0 (zero). The absorbent article as described in any one of <21>.
<23> Any of the above <1> to <22>, wherein the vertical groove of the protruding portion has a depth of 0.5 mm or more and 5.0 mm or less, and more preferably 1.0 mm or more and 3.0 mm or less. The absorbent article as described in any one.
<24> The longitudinal groove in the central region has a difference in length in the width direction between the opening and the bottom (La-Lb) of 0.5 mm to 3.0 mm, and more preferably 1.0 mm to 2 The absorbent article according to any one of <1> to <23>, which is 0.0 mm or less.
<25> The longitudinal groove in the central region has a depth ratio [depth / difference (La−Lb)] of 0 to a difference in length in the width direction between the opening and the bottom (La−Lb). The absorbent article according to any one of <1> to <24>, which is from 5 to 20 and more preferably from 1 to 10.
<26> The absorbent article according to any one of <1> to <25>, wherein the absorbent article is a sanitary napkin.

DESCRIPTION OF SYMBOLS 1 Sanitary napkin 2 Skin side sheet 2a Top surface sheet 2b Solid guard formation sheet 3 Non-skin side sheet S2 Side area upper surface 4,4A, AB Absorbent core 41 Central area 41a High density part 42 High basis weight part 43 Low Basis part 45 Side area 46 High basis weight part 47 Low basis weight part 5 Protruding part 6 Absorbent body 7 Wing part 8 Back flap part 11 Raised part 44 Horizontal groove 44a Horizontal groove in the central area 44b Horizontal groove in the lateral area 50 Central area Vertical groove 50a Vertical groove opening 50b Vertical groove bottom 50c Vertical groove wall 52 Vertical groove (side vertical groove)
54 Concentration concave part 55 Stacking drum 56 Bottom surface of the concave part for accumulation 56a Concave part Breathable member 57 Breathable member A Front part B Liquid excretion part opposite part C Rear part

Claims (7)

An absorbent article having an absorbent core having a long shape in the front-rear direction of the absorbent article,
The absorbent core has, in the width direction, a central region and lateral regions located on both sides thereof, and the central region has a protruding portion that protrudes upward from the upper surface of each of the lateral regions. ,
In the absorbent core, the central area and the side area are integrally formed, and the density in the both sides in the width direction of the central area is higher than that of the protruding portion, and the basis weight is higher than that of the side area. Has a high density part
On the skin contact surface of the protruding portion, a longitudinal groove having a bottom on the non-skin contact surface side is formed along the longitudinal direction of the absorbent core by reducing the basis weight of the absorbent core forming material. Formed,
In the absorbent article, the longitudinal groove has a width in the bottom that is narrower than the opening and gradually decreases in the width in the direction from the opening toward the bottom .   The absorbent article according to claim 1, wherein a lateral groove extending in the width direction of the absorbent core is formed in the protruding portion. A liquid-permeable surface sheet is disposed on the skin contact surface side of the absorbent core, and a pressing portion in which the surface sheet and the absorbent core are pressed together is provided in the central region,
The absorptive article according to claim 1 or 2 in which said surface sheet is indented in said press part in said longitudinal groove or transverse groove. A lateral longitudinal groove extending in the longitudinal direction of the absorbent core is formed on the skin contact surface side of the lateral region, and the lateral longitudinal groove has substantially the same width in the width direction of the opening and the bottom. The absorbent article according to any one of claims 1 to 3, wherein Side longitudinal grooves extending in the longitudinal direction of the absorbent core are formed on the skin contact surface side of the side region,
Wherein the high density portion, the absorbent article according to any one of claims 1 to 4 which is in contact the lateral longitudinal groove and the adjacent. The absorptive article given in any 1 paragraph of Claims 1-5 in which the bottom part of said longitudinal groove is located below the upper surface of said side field. Side longitudinal grooves extending in the longitudinal direction of the absorbent core are formed on the skin contact surface side of the side region,
The bottom surface of the longitudinal groove is positioned at the non-skin contact surface side than the bottom of the side circumferential groove, the absorbent article according to any one of claims 1-6.

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