WO2012165327A1

WO2012165327A1 - Absorbent article

Info

Publication number: WO2012165327A1
Application number: PCT/JP2012/063467
Authority: WO
Inventors: 剛大石川; 加藤　隆弘; 長原　進介; 宙夫安田; 裕美立川
Original assignee: 花王株式会社
Priority date: 2011-05-27
Filing date: 2012-05-25
Publication date: 2012-12-06

Abstract

In an absorbent article (1), an absorbent (4) is configured of an absorbent core (40) containing an absorbent material. The absorbent core (40) has high-weight parts (41) containing a relatively large amount of the absorbent material and low-weight parts (42) containing a relatively small amount of the absorbent material and the high-weight parts (41) and the low-weight parts (42) are alternately formed both in the lengthwise direction (X) and in the widthwise direction (Y) of the absorbent article (1). In the absorbent article (1), a groove (7) is formed by concaving a front face sheet (2) together with the absorbent core (40). The groove (7) is at least formed of a row of two high-weight parts (41) and (41) and one low-weight part (42), said low-weight part (42) being positioned between said two high-weight parts (41) and (41), that are aligned in the lengthwise direction (X) or in the widthwise direction (Y). A bottom wall part (71) constituting the groove (7) is positioned closer to the non-skin-contact face (4b) side than the thickness direction center (Tc) of the absorbent core (40).

Description

Absorbent articles

The present invention relates to absorbent articles such as sanitary napkins, disposable diapers, and incontinence pads.

As an absorbent article such as a sanitary napkin, a longitudinally long article having an absorbent body including a topsheet, a backsheet, and a liquid-retaining absorbent core interposed between both sheets is known. Further, in the absorbent article having such a configuration, the surface sheet and the absorbent body are integrally formed on the skin contact surface side for the purpose of damming the excretory fluid such as menstrual blood and preventing it from leaking outside. It is known to form a leak-proof groove that is recessed. For example, Patent Document 1 discloses an absorbent article in which a part (center portion) of an absorbent body has a middle-high portion whose thickness is increased on the skin contact surface side, and a leak-proof groove is formed around the middle-high portion. Are listed.

Patent Document 2 describes that an absorbent body in an absorbent article uses a plurality of absorbent portions that are spaced apart from each other and fixed to one side of a base sheet made of an elastic sheet or the like. In the absorbent body described in Patent Literature 2, an absorbent material is disposed at a lower basis weight than the absorbent portion between adjacent absorbent portions. According to the absorbent article described in Patent Document 2, by having the absorbent body having such a configuration, the absorbent article is deformed according to the complex undulating skin surface, and is deformed according to the movement of the wearer's body. In addition, it is said that high liquid absorption retention can be realized regardless of the presence or absence of deformation. Further, Patent Document 3 uses an absorbent body in an absorbent article in which a large number of individual absorbent parts are arranged over the plane direction, and the absorbent part is interposed between the top sheet and the back sheet. It is described that it is fixed to a sheet. In the absorbers described in

Patent Documents

2 and 3, the liquid absorbing portion (absorbent core) is partitioned into a plurality of regions (absorbing portions), and the plurality of absorbing portions are adhesives. They are common in that they are joined and fixed to the sheet by joining means such as the above.

Further, as an absorbent article such as a sanitary napkin, an absorbent body including a topsheet, a backsheet, and a liquid-retaining absorbent core interposed between both sheets is known, and a substantially vertically long article is known. Yes. The present applicant has previously proposed an absorbent article provided with a back sheet made of a moisture permeable sheet having a predetermined moisture permeability in order to effectively reduce the humidity in the wearing during use of the absorbent article. (See Patent Document 4). According to the absorbent article described in Patent Document 4, the humidity in the clothes is effectively reduced, there is less discomfort such as swelling and stickiness, and there is a comfortable texture, and skin troubles such as kayumi and burring are caused. Difficult to develop.

In addition, the applicant previously provided with an absorbent body, in addition to the absorbent article provided with the back sheet having a predetermined moisture permeability, formed by separating a large number of compressed parts recessed from the top sheet side from each other. An absorbent article was proposed (see Patent Document 5). According to the absorbent article described in Patent Document 5, it is excellent in liquid return at the time of use, and can provide a comfortable wearing feeling with a reduced wet feeling without leaving liquid on the surface.

Japanese Patent No. 4167406 WO2010134456 A1 US2010262108 A1 EP 0640328 A1 US2006041239 A1

As described in Patent Document 1, when a leak-proof groove is formed in a normal absorbent body in which the absorbent core is not partitioned into a plurality of regions, the excrement liquid is blocked by the leak-proof groove. While the effect of improving the leakage is achieved, i) the excretory fluid tends to stay locally, and the discomfort of the wearer due to wetting cannot be resolved, ii) the high-density leak-proof groove is the absorber Since the absorbent body is partially cured by being continuously formed, there is a possibility that inconveniences such as difficulty in fitting to the wearer's body and lowering of fitting property may occur.

Since the absorbent body described in

Patent Documents

2 and 3 has a configuration in which the absorbent core is partitioned into a plurality of regions (absorbing portions), the above-described i) and ii) compared to a normal absorbent body, In particular, although it is difficult to cause the inconvenience of ii), since the plurality of absorbing portions are bonded and fixed to the sheet by bonding means such as an adhesive, for example, the absorbing portion and the sheet are integrally formed from the same material. Compared to the case, the transferability of the excretory fluid between the two is inferior, and there is room for improvement in terms of the diffusion / absorption action of the excretory fluid in cooperation with the leak-proof groove. Therefore, the absorbent article which employ | adopted the combination of the absorber of

patent document

2 and 3 and a leak-proof groove has room for improvement in the wetting effect (side-leakage prevention effect) of the excretion liquid by a leak-proof groove especially. Yes, especially when there is a large amount of excretion at one time, the excretion fluid moves on the skin contact surface and reaches the leakage prevention groove, and further moves beyond the leakage prevention groove to the outside of the absorbent article, There is a risk of side leakage.

As a method for preventing such side leakage due to movement of excretory fluid beyond the leakage prevention groove, a method of arranging an absorbent body outside the absorbent article rather than the leakage prevention groove is conceivable. For example, when a leak-proof groove extending in the longitudinal direction of the absorbent article is formed, the absorbent body disposed inside the width-wise direction of the absorbent article from the leak-proof groove is absorbed from the leak-proof groove. The article is extended outward in the width direction. However, since this method requires an absorber having a certain size (width) having such an extended portion, it is difficult to reduce the size (width) of the absorber, which is a recent need. It is difficult to make the absorbent article compact, and the degree of freedom in product design is poor. There has not yet been provided an absorptive article that is excellent in the diffusion / absorption effect of excretory fluid by the cooperation between the absorbent body and the leak-proof groove, eliminates discomfort caused by the wearer's wetting, and is excellent in fit.

Further, as described above, according to the absorbent article described in Patent Document 4, it is possible to effectively reduce the humidity in the wearing, but in recent years, the humidity in the wearing is further effectively reduced. Thus, there has been an increasing demand for absorbent articles that further reduce the wet feeling and provide a more comfortable wearing feeling.

The present invention (first invention) is a vertically long absorbent comprising a top sheet disposed on the skin contact surface side, a back sheet disposed on the non-skin contact surface side, and an absorbent body interposed between both sheets. The absorbent body includes an absorbent core including an absorbent material, and the absorbent core includes a high basis weight portion in which the absorbent material is relatively large, and the absorbent material. Has a relatively low low basis weight part, and the high basis weight part and the low basis weight part are alternately formed in each of the longitudinal direction and the width direction of the absorbent article, and the absorbent The article is formed with a groove in which the top sheet and the absorbent core are integrally recessed, and the groove has at least two high basis weights arranged in the longitudinal direction or the width direction. Part and the one low basis weight part sandwiched between the two high basis weight parts to define the groove That the bottom wall portion, there is provided an absorbent article than the thickness direction center of the absorbent core is located at the non-skin contact surface side.

According to the absorbent article of the present invention (the first and third inventions), the excretory fluid can be absorbed and diffused quickly, and the discomfort caused by the wetness of the wearer can be eliminated.
In addition, according to the absorbent article of the present invention (second invention), the excretory fluid can be quickly absorbed and diffused, discomfort caused by the wetness of the wearer can be eliminated, and the leakage prevention groove is provided. Regardless, it has moderate flexibility and excellent fit.
Further, according to the absorbent article of the present invention (fourth invention), the humidity in the wearing during use can be effectively reduced, the wet feeling can be further reduced, and a more comfortable wearing feeling can be given.

FIG. 1 is a partially cutaway perspective view showing a sanitary napkin as an embodiment of the absorbent article of the present invention (first invention) from the skin contact surface side. FIG. 2 is a cross-sectional view schematically showing a cross section taken along line II of FIG. Fig. 3 (a) is a plan view showing the absorbent core used in the sanitary napkin in Fig. 1 from the skin contact surface side, and Fig. 3 (b) is a part of Fig. 3 (a). It is a top view which expands and shows (the part enclosed with the circle). FIG. 4 is a cross-sectional view schematically showing a cross section taken along line II-II in FIG. FIG. 5 is a cross-sectional view schematically showing a cross section taken along line III-III in FIG. FIG. 6 is a cross-sectional view schematically showing a cross section taken along line IV-IV in FIG. FIG. 7 is a schematic cross-sectional view of an embodiment of a method for manufacturing the absorbent body (absorbent core) shown in FIG. 3 and a manufacturing apparatus used therefor. FIG. 8 is a schematic cross-sectional view along the width direction of a part (concave portion) on the outer peripheral surface side of the rotating drum shown in FIG. FIG. 9 is a schematic cross-sectional view showing a state where an absorbent material is deposited in the concave portion of the rotating drum shown in FIG. FIG. 10 is an explanatory diagram of the compression process of the deposit. FIG. 11 is an explanatory diagram of a method for evaluating air permeability by the Gurley tester method.

FIG. 12 is a partially cutaway perspective view showing a sanitary napkin as an embodiment of the absorbent article of the present invention (second invention) from the skin contact surface side. 13 is a cross-sectional view schematically showing a cross section taken along line II of FIG. Fig. 14 (a) is a plan view showing the absorbent core used in the sanitary napkin in Fig. 12 from the skin contact surface side, and Fig. 14 (b) is a part of Fig. 14 (a). It is a top view which expands and shows (the part enclosed with the circle). FIG. 15 is a cross-sectional view schematically showing a cross section taken along line II-II in FIG. FIG. 16 is a cross-sectional view schematically showing a cross section taken along line III-III in FIG. FIG. 17 is a cross-sectional view schematically showing a cross section taken along line IV-IV in FIG. 18 (a) is a plan view (a view corresponding to FIG. 14 (b)) showing an enlarged part of the absorbent core shown in FIG. 14 (a), and FIG. 18 (b) and FIG. 18 (c). These are each a top view which expands and shows a part of absorptive core and groove | channel outside the range of this invention (2nd invention).

FIG. 19 is a partially cutaway perspective view showing a sanitary napkin as an embodiment of the absorbent article of the present invention (third invention) from the skin contact surface side. 20 is a cross-sectional view schematically showing a cross section taken along line II of FIG. FIG. 21 (a) is a plan view showing the absorbent core used in the sanitary napkin in FIG. 19 from the skin contact surface side, and FIG. 21 (b) is a part of FIG. 21 (a). It is a top view which expands and shows (the part enclosed with the circle). FIG. 22 is a cross-sectional view schematically showing a cross section taken along line II-II in FIG. FIG. 23 is a cross-sectional view schematically showing a cross section taken along line III-III in FIG. FIG. 24 is a cross-sectional view schematically showing a cross section taken along line IV-IV in FIG. FIG. 25 is a plan view schematically showing an enlarged part (a tear and its vicinity) of FIG.

FIG. 26 is a partially cutaway perspective view showing an embodiment of an absorbent article of the present invention (fourth invention) from the skin facing surface side. 27 is a cross-sectional view schematically showing a cross section taken along line Y1-Y1 of FIG. FIG. 28 is a plan view showing the absorbent core used in the absorbent article shown in FIG. 26 from the skin facing surface side. 29A is a cross-sectional view schematically showing a cross section taken along line Y2-Y2 of FIG. 28, and FIG. 29B is a cross-sectional view schematically showing a cross section taken along line Y3-Y3 of FIG.

The present invention (the first invention and the third invention) relates to an absorbent article that can quickly absorb and diffuse excretory fluid and eliminate discomfort caused by the wetness of the wearer.
In addition, the present invention (second invention) absorbs and diffuses excreted fluid quickly, eliminates discomfort caused by the wearer's wetting, and has moderate flexibility despite having a leak-proof groove. The present invention also relates to an absorbent article excellent in fit.
Moreover, this invention (4th invention) is providing the absorbent article which can satisfy the demand mentioned above.

Hereinafter, the absorbent article of the present invention (first invention) will be described with reference to the drawings based on a sanitary napkin which is a preferred embodiment thereof. As shown in FIGS. 1 and 2, the napkin 1 A of this embodiment includes a top sheet 2 disposed on the skin contact surface side, a back sheet 3 disposed on the non-skin contact surface side, and both sheets 2. 4A is provided, and is vertically long (long shape in one direction). As shown in FIG. 1, the napkin 1 A is disposed on the abdomen side of the wearer with respect to the excretory part facing part 11 disposed opposite to the excretion part (vaginal opening) of the wearer at the time of wearing. The front portion 12 and the rear portion 13 disposed on the back side of the wearer rather than the excretory portion facing portion 11 at the time of wearing are provided in the longitudinal direction X. The excretory part opposing part 11 is a part which has a pair of

wing parts

6 and 6 on either side mentioned later. The pair of

wing parts

6 and 6 are parts that are wound around the crotch part (crotch part) of the underwear when the napkin 1A is fixed to the underwear such as shorts. In addition, when the absorbent article (sanitary napkin) of the present invention (first invention) does not have a wing part, the excretory part facing part of the sanitary napkin has a so-called short length of 25 cm or less in the product longitudinal direction. The time / daytime napkin is the central part (second area from the front) when the napkin is divided into three equal parts in the longitudinal direction to form the front part, the central part, and the rear part. In the so-called long daytime and nighttime napkins that exceed this, it is the second region from the front (the third region from the back) when these napkins are equally divided into four in the longitudinal direction.

In the present specification, the skin contact surface is a surface of the absorbent article or a component thereof that faces the wearer's skin when the absorbent article is mounted, and the non-skin contact surface is the absorbent article. Alternatively, the surface of the member is directed to the side opposite to the skin side (clothing side) when the absorbent article is mounted. Moreover, a longitudinal direction is a direction along the long side of an absorbent article or its structural member, and a width direction is a direction orthogonal to this longitudinal direction. In the figure, the direction indicated by the symbol X is the longitudinal direction of the absorbent article (absorber, absorbent core), and the direction indicated by the symbol Y is the width direction of the absorbent article (absorber, absorbent core). .

As shown in FIG. 2, the top sheet 2 covers the entire skin contact surface 4 a of the absorbent body 4 A, and further extends outward in the width direction Y from the left and right side edges along the longitudinal direction X of the absorbent body 4. Further, the back sheet 3 covers the whole area of the non-skin contact surface 4b of the absorbent body 4A, and further extends outward in the width direction Y from both side edges of the absorbent body 4A. Further, the top sheet 2 and the back sheet 3 also extend outward in the longitudinal direction X from the front end and the rear end in the longitudinal direction X of the absorbent body 4A. They are joined together by a known joining means such as an ultrasonic seal.

As shown in FIGS. 1 and 2, a pair of

side sheets

5 and 5 are disposed on the left and right side portions along the longitudinal direction X of the napkin 1 A over the entire length of the napkin 1 A in the longitudinal direction X. The side sheet 5 has an inner side in the width direction Y joined to the skin contact surface 2a of the surface sheet 2 by a known joining means, and an outer side of the side sheet 5 of the absorber 4A. It extends outward in the width direction Y from the side edge along the longitudinal direction X, and the extension part is joined to the extension part from the side edge of the absorber 4A in the back sheet 3 by a known joining means. Yes. The back sheet 3 and the side sheet 5 have the maximum length extending outward in the width direction Y from the side edge of the absorber 4A in the excretory part facing part 11, and the maximum extension part A pair of

wing portions

6 and 6 are formed.

The non-skin contact surface of the napkin 1A (the non-skin contact surface 3b of the back sheet 3) is directed to the clothing side, such as the crotch portion of the shorts when worn. The non-skin contact surface 3b is provided with an adhesive portion (not shown) for fixing the napkin 1A to a crotch portion of underwear such as shorts. Further, the non-skin contact surfaces (non-skin contact surface 3b of the back sheet 3) of the pair of

wing portions

6 and 6 are adhesive portions (not shown) for fixing to the outer surface (non-skin contact surface) of the shorts. Z). These adhesive portions are provided by applying a hot melt adhesive at a predetermined location, and are covered with a release sheet (not shown) made of a film, nonwoven fabric, paper, etc. before using the napkin 1A.

The absorbent body 4A includes an absorbent core 40A including an absorbent material (fiber material such as pulp, water-absorbing polymer, etc.). The absorbent body 4A in the present embodiment is configured by covering the absorbent core 40A with a core wrap sheet (not shown) made of tissue paper or a water-permeable nonwoven fabric. The absorbent core 40A may be composed of only a fiber material such as pulp together with the high basis weight portion 41 and the low basis weight portion 42, which will be described later, or includes the fiber material and a water-absorbing polymer. In the latter case, the water-absorbing polymer may be uniformly mixed between the fiber materials, or may include a fiber layer mainly composed of the fiber material and a polymer layer mainly composed of the water-absorbing polymer, and The polymer layer may be sandwiched between the two fiber layers. Between the top sheet 2 and the absorber 4A, and between the absorber 4A and the back sheet 3 are bonded to each other by a pattern-coated adhesive (hot melt adhesive or the like) such as dots, spirals, and stripes. Also good.

As shown in FIGS. 2 and 3, the absorbent core 40A includes a high basis weight portion 41 having a relatively large amount of absorbent material and a low basis weight portion 42 (42X, 42Y) having a relatively small amount of absorbent material. The high basis weight portions 41 and the low basis weight portions 42 are alternately formed in the longitudinal direction X and the width direction Y, respectively. More specifically, the absorbent core 40A has a linear low basis weight portion 42X extending along the longitudinal direction X and a linear low basis weight portion extending along the width direction Y, as shown in FIG. 42Y and a plurality of low basis weight portions 42 are formed in a lattice shape as a whole, and a portion partitioned by these linear low

basis weight portions

42X and 42Y is a high basis weight portion 41. . Each of the plurality of linear low basis weight portions 42X is formed to extend over the entire length in the longitudinal direction X of the absorbent core 40A, and each of the plurality of linear low basis weight portions 42Y is absorbent. The core 40A is formed to extend over the entire length in the width direction Y. Each of the plurality of high basis weight portions 41 has a rectangular shape in plan view as shown in FIG.

In the present embodiment, as shown in FIG. 2, the absorbent core 40A has a uniform apparent thickness, so that the high basis weight portion 41 is compared to the low basis weight portion 42 (42X, 42Y). Therefore, the absorbent core 40A has an uneven structure in which the high basis weight portion 41 is raised as compared with the low basis weight portion 42. When the absorbent core 40A has a concavo-convex structure, the absorbent core 40A absorbs when the napkin 1A is attached, as compared with the case where the skin contact surface and the non-skin contact surface are both substantially flat. Deformation of the absorbent core 40A (absorber 4A), specifically, deformation of the absorbent core 40A into a shape that protrudes toward the skin of the napkin wearer is easily induced. Due to the ease of deformation of the absorbent core 40A, the excretory part-facing portion 11 is easily deformed into a shape that is pressed against the skin of the napkin wearer when the napkin 1A is worn. A comfortable wearing feeling is given to the person, and leakage of menstrual blood is effectively suppressed.

In the cross-sectional view of the absorbent core 40A as shown in FIG. 2, the low basis weight portions 42 (42X, 42Y) are unevenly distributed in the thickness direction of the absorbent core 40A. More specifically, in the present embodiment, as shown in FIG. 2, the low basis weight portion 42 is unevenly distributed on the skin contact surface 4a side in the thickness direction T of the absorbent core 40A. And since the low basic weight part 42 is unevenly distributed in the skin contact surface 4a side in the thickness direction T in this way, the high basic weight part 41 is the opposite side to the skin contact surface 4a, ie, thickness direction. In T, it protrudes to the non-skin contact surface 4b side. Therefore, in the absorbent core 40A, the skin contact surface 4a (the surface facing the top sheet 2) is substantially flat and substantially flat (no flatness and flat) except for the formation portion of the groove 7 described later. On the other hand, the non-skin contact surface 4b (opposite surface to the back sheet 3) has a low basis weight located between the projecting high basis weight portion 41 (convex portion) and the high

basis weight portions

41, 41. It has unevenness due to the portion 42 (non-convex portion or concave portion). In this way, when the low basis weight portion 42 is unevenly distributed on the skin contact surface 4a side in the absorbent core 40A, as shown in FIG. 2, the non-skin contact surface on the opposite side to the skin contact surface 4a side. Since the space portion (non-convex portion or concave portion) due to the absence of the low basis weight portion 42 is formed on the 4b side, the absorbent core 40A is based on the low basis weight portion 42 on the skin contact surface 4a side. It is easy to deform | transform into the shape which protrudes toward a napkin wearer's skin as an effect, Therefore, the improvement effect of a fitting property and the effect of a menstrual blood leak prevention are show | played.

In the present invention (first invention), the uneven distribution position of the low basis weight portion 42 (42X, 42Y) in the thickness direction T of the absorbent core 40A is not limited to the skin contact surface 4a side as shown in FIG. For example, on the contrary, the non-skin contact surface 4b side may be sufficient. That is, in a cross-sectional view of the absorbent core 40A, the low basis weight portion 42 may be unevenly distributed on the non-skin contact surface 4b side in the thickness direction T of the absorbent core 40A. In that case, the high basis weight portion 41 protrudes on the side opposite to the non-skin contact surface 4b side, that is, on the skin contact surface 4a side in the thickness direction T, and as shown in FIG. Is upside down. Therefore, in the absorbent core 40A in which the low basis weight portion 42 is unevenly distributed on the non-skin contact surface 4b side, the non-skin contact surface 4b (opposite surface to the back sheet 3) is substantially flat. On the other hand, the skin contact surface 4a (the surface facing the top sheet 2) has a high basis weight portion 41 (convex portion) formed so as to protrude and a low basis weight portion located between the high

basis weight portions

41, 41. 42 (non-convex portion or concave portion), and a space portion (non-convex portion or concave portion) due to the absence of the low basis weight portion 42 is formed on the skin contact surface 4a side. Since the space portion on the skin contact surface 4a side is formed so as to be sandwiched between two adjacent high

basis weight portions

41, 41, the shape of the space portion is easily maintained even when the napkin is mounted. The air existing between the skin of the napkin wearer and the napkin 1A is ventilated by the space portion, and the stuffiness felt by the napkin wearer is reduced.

Further, in the present invention (first invention), in the cross-sectional view of the absorbent core 40A, the low basis weight portion 42 (42X, 42Y) and the skin contact surface 4a in the thickness direction T of the absorbent core 40A and the non-skin You may be unevenly distributed in the approximate center part with the contact surface 4b. In this case, the high basis weight portion 41 protrudes in the thickness direction T on the skin contact surface 4a side and the non-skin contact surface 4b side. Therefore, in the absorbent core 40A in which the low basis weight portion 42 is unevenly distributed in the approximate center between the skin contact surface 4a and the non-skin contact surface 4b, the skin contact surface 4a and the non-skin contact surface 4b respectively. However, the skin contact surface has irregularities due to the protruding high basis weight portion 41 (convex portion) and the low basis weight portion 42 (non-convex portion or concave portion) located between the high

basis weight portions

41, 41. Space portions (non-convex portions or concave portions) due to the absence of the low basis weight portions 42 are formed on the 4a side and the non-skin contact surface 4b side, respectively. The absorbent core 40A having such a configuration is directed toward the skin of the napkin wearer with the low basis weight portion 42 positioned at a substantially central portion in the thickness direction T (substantially central portion of the apparent thickness of the absorbent core 40A) as a basic axis. It is easy to be deformed into a raised shape, and the space part also has an effect of ventilating air existing between the napkin wearer's skin and the napkin 1A.

Thus, in this invention (1st invention), the uneven distribution position of the low basic weight part 42 (42X, 42Y) in the thickness direction T of 40 A of absorbent cores is the effect (absorbent core) show | played resulting from it. Depending on which one of the deformation induction effect and ventilation effect of 40A is particularly desired, the skin contact surface 4a side, the non-skin contact surface 4b side, or the skin contact surface 4a side as shown in FIG. It is possible to appropriately select from the substantially central portion with the skin contact surface 4b.

The absorbent core 40A according to the present embodiment (the concavo-convex structure) has a plurality of absorption parts each having a rectangular shape in a plan view made of an absorbent material on one surface side of the absorbent material formed into a thin plate shape. It may appear to be similar to the absorbent body described in Patent Documents 2 and 3 (absorbent body in which a plurality of absorbent parts are fixed to a sheet) in that it is configured to be spaced apart. However, as will be described later, the absorbent core 40A according to this embodiment is manufactured by molding an absorbent material so as to have the uneven structure, and includes a high basis weight portion 41 and a low basis weight portion. 42 is integrated without using a bonding means such as an adhesive or heat-sealing, and is formed so as not to have a boundary (boundary between the high basis weight portion 41 and the low basis weight portion 42) by the same material. On the other hand, the absorbers described in

Patent Documents

2 and 3 are manufactured by fixing a plurality of the absorbing parts to the sheet separate from the absorbing parts, and the absorbing parts And the sheet are joined to each other via a joining means and have a boundary between the absorbing portion and the sheet, and they are different in this respect. And by the difference of such a structure, while the high basic weight part 41 and the low basic weight part 42 which concern on this embodiment have the continuity in which a liquid can move smoothly, patent document 2 And the absorbent portion and the sheet in the absorbent body according to 3, since there is an interface composed of joining means between them (boundary), liquid diffusion easily occurs at the boundary portion, and the liquid can move smoothly. It is hard to say that it has continuity.

In the napkin 1A, as shown in FIGS. 1 to 3, a groove 7 is formed in which the topsheet 2 and the absorbent core 40A are recessed integrally. The groove 7 is a space (a portion where the material for forming the napkin 1A does not exist) defined by a bottom wall portion 71 and a side wall portion 72 described later. As shown in FIG. 3A, the groove 7 includes a pair of

vertical grooves

7X and 7X that continuously extend in the longitudinal direction X and two horizontal grooves 7Y1 and 7Y2 that extend continuously in the width direction Y. These four grooves are connected at their respective end portions to form an annular groove as a whole. The pair of

longitudinal grooves

7X and 7X extend over the entire length in the longitudinal direction X of the excretory part facing part 11 at the left and right side parts along the longitudinal direction X of the absorbent core 40A, and further, the front part 12 and the rear part 13 also extends to each. The lateral groove 7Y1 is formed in the front part 12, and the lateral groove 7Y2 is formed in the rear part 13, respectively. Both lateral grooves 7Y1 and 7Y2 are formed to include a horizontally long shape that is convexly convex outward in the longitudinal direction X in plan view, and the tops of the protrusions of both lateral grooves 7Y1 and 7Y2 have a width of Located in the center of the direction Y.

The groove 7 (7X, 7Y1, 7Y2) can be formed in accordance with an ordinary method by embossing such as embossing with or without heat, or ultrasonic embossing. That is, in the manufacturing process of the napkin 1A, after supplying the topsheet 2 on one surface of the absorber 4A (absorbent core 40A having an uneven structure), a predetermined portion is moved from the topsheet 2 side to the absorber 4A side by embossing. The groove 7 can be formed in the predetermined portion by pressing (squeezing) in a concave shape. In the groove 7, the top sheet 2 and the absorbent body 4 A are integrated by heat fusion or the like. The groove 7 has a large number of deep depressions (relatively deep depressions, high embossing parts) and shallow depressions (relatively shallow depressions) such as rectangles, squares, rhombuses, circles, and crosses in plan view. Part, low embossed part) may be alternately connected to form a continuous line as a whole, or a plurality of hollow parts may be intermittently arranged. “Intermittently” means that the interval between adjacent recesses is 5 mm or more.

The groove 7 includes at least two high basis weight portions (convex portions) 41, 41 arranged in the longitudinal direction X or the width direction Y and one low

basis weight portion

41, 41. It is formed continuously with the basis weight part (non-convex part or concave part) 42. That is, the groove 7 is formed so as to straddle the unevenness of the absorbent core 40A. In the present embodiment, as shown in FIG. 3 (a), with respect to the longitudinal direction X, a pair of longitudinal grooves 7X that are a part of the groove 7 in the excretory part facing part 11 that is a part that directly receives excretion fluid. Each of 7X is formed to be connected to two high

basis weight portions

41, 41 adjacent to each other in the longitudinal direction X and one low basis weight portion 42Y positioned therebetween, and absorbs continuously to the longitudinal direction X. It is formed so as to straddle the irregularities of the core 40. Regarding the width direction Y, in the front portion 12, the lateral groove 7Y1, which is a part of the groove 7, is adjacent to the two high

basis weight portions

41, 41 in the width direction Y and one piece between them. It is formed continuously with the low basis weight portion 42 X, and further, in the rear portion 13, the lateral groove 7 Y 2 that is a part of the groove 7 is formed in a similar manner.

Such a positional relationship between the groove 7 and the high basis weight portion 41 and the low basis weight portion 42 is to make sure that the excretory fluid absorption / diffusion action according to the present invention (first invention) to be described later is performed more reliably. In particular, as described above, the groove 7 (vertical groove 7X) is formed so as to straddle the irregularities of the absorbent core 40A continuous in the longitudinal direction X. The excretion fluid moves in the width direction Y. This is important because it relates to the effect of preventing leakage to the outside (so-called side leakage) caused by the above. Therefore, in the present embodiment, as a device for ensuring that the arrangement over the unevenness of the groove 7 is obtained more reliably, in the longitudinal direction X of the napkin 1A, the low basis weight portion 42 is as described above. The groove 7 is formed so as to include a linear portion 42X extending in the longitudinal direction X in plan view, and the groove 7 includes a portion 7X having a curved portion and extending in the longitudinal direction X in plan view. Forming. That is, in the present embodiment, the pair of

longitudinal grooves

7X and 7X, which are a part of the groove 7, are respectively in the longitudinal direction of the napkin 1A in the excretory part facing part 11 as shown in FIG. Each of both side portions along X includes a vertically long shape that is convexly curved outward in the width direction Y of the napkin 1A. As described above, the low basis weight portion 42X of the absorbent core 40A is formed in a linear shape that completely coincides with the longitudinal direction X of the absorbent core 40A, while the longitudinal groove 7X is completely different from the longitudinal direction X. By forming it so as to have a curved portion that does not match (partially matches), at least the curved portion of the longitudinal groove 7X is completely the same as the linear low basis weight portion 42X extending in the longitudinal direction X in plan view. And the vertical grooves 7X are easily formed so as to straddle the irregularities of the absorbent core 40A continuous in the longitudinal direction X.

Further, in the present embodiment, from the same viewpoint as described above, the low basis weight portion 42 is formed so as to include the linear portion 42Y extending in the width direction Y in plan view as described above, and the groove 7 is formed so as to include portions 7Y1 and 7Y2 having a curved portion in a plan view and extending in the width direction Y. That is, in the present embodiment, the lateral grooves 7Y1 and 7Y2 which are part of the groove 7 are respectively formed in the napkin 1A at the front part 12 or the rear part 13 of the napkin 1A as shown in FIG. Of the horizontal grooves 7Y1 and 7Y2 so that at least the curved portions of the lateral grooves 7Y1 and 7Y2 are linear low-tsubo extending in the width direction Y in plan view. The lateral grooves 7Y1 and 7Y2 do not completely coincide with the amount portion 42Y, and the lateral grooves 7Y1 and 7Y2 are easily formed so as to straddle the unevenness of the absorbent core 40A continuous in the width direction Y.

4 to 6 schematically show the cross section of the groove 7 in each part of the absorbent core 40A. The groove 7 (7X, 7Y1, 7Y2) is defined by a bottom wall portion 71 and a side wall portion 72 standing from the bottom wall portion 71, as shown in FIGS. As shown in FIGS. 5 and 6, the bottom wall portion 71 that defines the groove 7 is less than the center Tc in the thickness direction of the absorbent core 40 A in both the high basis weight portion 41 and the low basis weight portion 42. It is located on the skin contact surface 4b side. When the absorbent core 40A has an uneven structure as in the present embodiment, the thickness direction center Tc is the center of the apparent thickness of the absorbent core 40A having the uneven structure. It is located in the middle between the skin contact surface 4a and the portion that protrudes most toward the non-skin contact surface 4b. When the absorbent core 40A does not have an uneven structure, the thickness direction center Tc is the center of the substantial thickness of the absorbent core 40A, and the skin contact surface 4a and the non-skin contact in the absorbent core 40A. Located in the middle of the contact surface 4b.

In this way, when the bottom wall portion 71 that defines the groove 7 is designed to be positioned on the non-skin contact surface 4b side with respect to the thickness direction center Tc, the skin contact of the absorbent core 40A when the groove 7 is formed. In pressing from the surface 4a side, 1) In the high basis weight part 41, the part which becomes the bottom wall part 71 and the part which becomes the side wall part 72 which define the groove 7 after the pressing are respectively compressed, so that the groove 7 2) In the low basis weight portion 72, the low basis weight portion 72 is deformed in accordance with the shape of the groove 7 from the skin contact surface 4a side by the pressing, so that the low basis weight portion 72 is partially Stretched. And the groove | channel 7 obtained after the said pressing, ie, the groove | channel 7 in which the bottom wall part 71 is located in the non-skin contact surface 4b side rather than the thickness direction center Tc, is the groove | channel 7 in the high basic weight part 41. Since the shape of the liquid is stable, the attraction of liquid by capillary force is enhanced, and in the low basis weight portion 72, the groove 7 is extended and the thickness is reduced, so that the liquid is diffused. As a result, the amount of liquid is easily moved to the high basis weight portion 41 in the groove 7 (mainly the side wall portion 72). From the viewpoint of more surely exhibiting such an effect, the bottom wall 71 defining the groove 7 is 0.1 mm or more, particularly 0.2 mm or more from the thickness direction center Tc to the non-skin contact surface 4b side. It is preferable to exist in a distant position.

Positioning the bottom wall portion 71 that defines the groove 7 closer to the non-skin contact surface 4b than the center Tc in the thickness direction of the absorbent core 40A is by adjusting the squeezing force or the like when forming the groove 7. Basically, it is possible, but it becomes more reliable by devising the configuration of the absorbent core 40A. As described above, the groove 7 is formed by squeezing the absorbent core 40A together with the top sheet 2. In particular, the relatively thin portion such as the low basis weight portion 42 has the groove 7 as described above. By being formed so as to straddle the unevenness of the absorbent core 40A, the degree of squeezing is suppressed lower than that of the high basis weight portion 41, and the bulk tends to recover to some extent after squeezing. Moreover, in the high basic weight part 41, at the time of formation of the groove | channel 7, the shape of the groove | channel 7 is formed by being squeezed over the part used as the side wall part 72 from the part used as the bottom wall part 71 which defines the groove | channel 7 after pressing. In the low basis weight portion 42, the portion to be squeezed by the formation of the groove 7 is the bottom wall portion 71 and its periphery, and is compressed as compared with the high basis weight portion 41, while it is in a state that is relatively easily maintained. Since there are few parts to squeeze, the volume of the part squeezed after squeezing is easy to recover. Therefore, immediately after squeezing, even if the bottom wall portion 71 that defines the groove 7 formed by squeezing is located on the non-skin contact surface 4b side with respect to the thickness direction center Tc, the bottom wall is recovered by the bulk recovery with time. The portion 71 moves to the skin contact surface 4a side, and finally, in the low basis weight portion 42, the bottom wall portion 71 may be located closer to the skin contact surface 4a than the thickness direction center Tc. This is prevented, and the bottom wall portion 71 that defines the groove 7 is reliably positioned closer to the non-skin contact surface 4b side than the center Tc in the thickness direction not only in the high basis weight portion 41 but also in the low basis weight portion 42. For this purpose, the distance L1 (see FIG. 3) across which the groove 7 crosses the low basis weight portion 42, that is, the width L1 of the linear low basis weight portion 42 (42X, 42Y) should not be set too long. Is effective. By reducing the width L1 of the low basis weight part 42 to some extent, the bulk recovery of the low basis weight part 42 after pressing for the formation of the groove 7 is suppressed, and the bottom wall part 71 that defines the groove 7 is thickened. It becomes more reliable to position it on the non-skin contact surface 4b side than the direction center Tc. From such a viewpoint, the width L1 of the low basis weight portion 42 is preferably 1 to 5 mm, more preferably 1 to 3 mm. The low

basis weight portions

42X and 42Y may have the same or different width L1.

Incidentally, as described above, in the case where the groove 7 is formed by alternately connecting the deep depressions and the shallow depressions, the deep depressions of the grooves 7 are formed only in the low basis weight 41. When the absorbent core 40A is squeezed, the volume of the squeezed portion is difficult to recover after squeezing, and thus the above-described effects are hardly obtained. Therefore, in order to reliably obtain the above-described effect, there is a method in which the length in the longitudinal direction X of the napkin 1A of the deep depression is longer than the width L1 of the linear low basis weight portion 42 (42X, 42Y). It is valid. Other than such a method, the formation direction of the groove 7 (direction in which the linear groove 7 extends) is inclined with respect to the formation direction of the low basis weight part (direction in which the linear low basis weight part extends) (both formations). A method of setting a predetermined angle between directions) is effective.

In the present embodiment, the high basis weight portion 41, the low basis weight portion 42, the groove 7, and the vicinity thereof, the high basis weight portion 41 has a higher density than the low basis weight portion 42, and the groove 7 is further formed. There is a density gradient. That is, in FIGS. 3B and 4 to 6, the density of the parts indicated by reference signs A to E is A ≦ B << C << E, more preferably A << B << C <D <E. The density decreases as the distance from the groove 7 (vertical groove 7X) decreases (site A), and the density increases as the distance from the groove 7 increases (area B and / or C). In the groove 7 (bottom wall portion 71), The density is maximized (sites D and E). Moreover, about the groove | channel 7 (bottom wall part 71), the site | part D in the low basic weight part 42 (42Y) is along the groove | channel 7 because the density is made a little low compared with the site | part E in the high basic weight part 41. It is more preferable that the density of the liquid is higher than that of the part C in the vicinity of the groove 7 in the high basis weight portion 41. The density gradient that the density increases as it approaches the groove 7 is mainly caused by the formation of the groove 7 by the above-described embossing (squeezing of the absorbent core 40A), and an absorbent body in which a conventional leak-proof groove is formed. Also exists. In this embodiment, the density gradient is characterized in that the part C has a higher density (B << C) than the part B, and the vicinity of the groove 7 is the density of the high basis weight portion 41 and the low basis weight portion 42. Is different. The “near the groove” means the side wall portion 72 (see FIGS. 4 to 6) that defines the groove 7 and the vicinity thereof, and mainly the length of the groove 7 from the groove 7 (the outer surface of the side wall portion 72). It means a portion within 5 mm outside the direction perpendicular to the vertical direction (width direction of the groove 7).

As described above, the portions B and C in the vicinity of the groove 7 (vertical groove 7X) have the same distance from the groove 7, but the portion C located in the high basis weight portion 41 has a lower basis weight. The reason why the density is higher than the portion B located in the amount portion 42 (42Y) is that the high basis weight portion 41 is more absorbent than the low basis weight portion 42 before the groove 7 is formed by pressing the absorbent core 40A. This is because there are many materials and the density is high. That is, as will be described later, the absorbent core 40A according to the present embodiment deposits an absorbent material so as to have a high basis weight portion 41 and a low basis weight portion 42 to obtain a deposit having an uneven structure, When the entire deposit is produced by compressing the entire deposit with a uniform compressive force using a pressure roll or the like, in such a compression step, the high basis weight portion 41 as a convex portion is more likely to be a non-convex portion or a concave portion. Since it is compressed more strongly than the low basis weight portion 42, the high basis weight portion 41 (site C) has a higher density than the low basis weight portion 42 (site B). Thus, there is a difference in density between the part B and the part C before the formation of the groove 7, and when the groove 7 is formed in the part B and the part C by pressing, the side wall part 72 that defines the groove 7. And this density difference is reflected in the vicinity thereof, and as a result, B << C with respect to the density.

The napkin 1A of the present embodiment has a concavo-convex structure formed by a high basis weight part (convex part) 41 and a low basis weight part (non-convex part or concave part) 42 as an absorbent core in which the grooves 7 are formed. By adopting the absorbent core 40A, it is possible to solve the above-mentioned problem ii) that the absorbent article employing the conventional combination of a flat absorbent core without unevenness and a leak-proof groove has, and the absorbent body 4A ( Despite the formation of the high-density grooves 7 in the absorbent core 40), the absorber 4A is hardly cured and has excellent fit. As shown in FIG. 3, when the low basis weight portion 42 is formed on the outer side of the napkin 1 A (outer part of the groove 7) than the groove 7, the leakage prevention effect by the groove 7 is further increased, and the napkin A soft feel can be given to the peripheral edge of 1 (particularly both side edges along the longitudinal direction X of the napkin 1A). Moreover, as shown in FIG. 3, when the site | part in which the high basic weight part 41 was enclosed by the low basic weight part 42 is distribute | arranged to the substantially whole absorbent core 40A, it is with respect to a wearer at the time of mounting | wearing of the napkin 1A. The hit becomes soft and can provide a flexible feel.

Further, in the napkin 1A of the present embodiment, the groove 7 is mainly connected to two high

basis weight portions

41, 41 adjacent to each other in a predetermined direction and one low basis weight portion 42 positioned therebetween. By being formed so as to straddle the irregularities of the absorbent core 40A, excretion fluid such as menstrual blood can be quickly absorbed and diffused regardless of the amount thereof, The above-mentioned problem i) of an absorbent article employing a combination of a conventional flat absorbent core having no irregularities and a leak-proof groove can be solved, has excellent leak-proof properties (side-leakage prevention properties), and an absorber. Therefore, it is possible to cope with downsizing of the absorbent article and further downsizing of the absorbent article.

Explaining the absorption / diffusion action of the excretory fluid in the napkin 1A of this embodiment with reference to FIG. 3B, the excretory fluid W such as menstrual blood excreted by the wearer of the napkin 1A is usually facing the excretory part It is received at the center in the width direction Y of the portion 11 and moves in the width direction Y from the skin contact surface (skin contact surface 2a of the topsheet 2) toward the groove 7 (vertical groove 7X), for example, FIG. In (b), various components (surface sheet) of the napkin 1A from the part A (near the central part in the width direction Y of the excretory part facing part 11) toward the part B (near the groove 7 in the low basis weight part 42). 2, move along the absorbent core 40A and the like. As described above, since there is a density difference between the part B and the part C and the density is B << C, the excretory liquid W that has reached the part B is a groove in the high basis weight portion 41 due to capillary force. 7 easily moves to a part C that is in the vicinity of 7 and hardly stays in the part B. Thus, the excretion liquid W moves in the front-rear direction of the napkin 1A along the groove 7 in the vicinity of the groove 7 and inward in the width direction Y from the groove 7, and quickly from the excretion part facing part 11 in the longitudinal direction X. To spread.

Since the part B exists not as a mere gap (space) located between the adjacent high

basis weight parts

41, 41 but as a part of the absorbent core 40A (low basis weight part 42), the excretion fluid is retained. It has a function. Therefore, the amount of the excretory fluid W is large, and the moving speed of the excretory fluid W from the site A to the site B is higher than the moving speed of the excreted fluid W from the site B to the site C (diffusion rate in the longitudinal direction X). Even when it is fast, the excretory fluid can be temporarily held at the site B. Therefore, the site D (the groove 7 in the low basis weight portion 42 is defined outside the site B in the width direction Y of the napkin 1A). A large amount of excretory liquid is prevented from moving to the bottom wall portion 71) formed at the same time. As a result, the excretory liquid W moves over the groove 7 to the outside in the width direction Y of the napkin 1A and leaks laterally. It is prevented that it leads to. In addition, the fact that the part B itself has a relatively high density due to the squeezing at the time of forming the groove 7 also suppresses the movement of the liquid from the part B to the part D and thus contributes to the prevention of side leakage. ing.

The excretory liquid W is quickly absorbed and held by the high basis weight portion 41 while moving from the portion B to the portion C in the vicinity of the groove 7 and inward in the width direction Y from the groove 7. As shown in FIG. 6, the portion exceeding the absorption capacity of the portion E is located in the portion E (the bottom wall portion 71 that defines the groove 7 in the high basis weight portion 41) located outside the portion C in the width direction Y. Moving. The site E is the most compressed site when the groove 7 is formed, and the density thereof is overwhelmingly higher than the site C adjacent to the width direction Y. Therefore, the excretion fluid W moves from the site E to the site C. Therefore, it is unlikely that the excretion liquid W moves beyond the groove 7 to the outside in the width direction Y of the napkin 1A. This is the same as the relationship between the part B and the part D in the low basis weight portion 42 described above. The excretion fluid W that has moved to the site E via the site C passes through the groove 7 without leaking to the outside of the groove 7, and is adjacent to the site D (the bottom wall that defines the groove 7 in the low basis weight portion 42. Part 71) and further to another part E adjacent thereto. Thus, the excretory fluid W moving in the groove 7 is absorbed and held mainly by the high basis weight portion 41 during the movement.

As described above, in the napkin 1A of the present embodiment, the excreted liquid excreted in the central part in the width direction Y of the excretory part facing part 11 is closer to the longitudinal groove 7X and the longitudinal groove 7X than the longitudinal groove 7X. In both of the portions located inward in the width direction Y, the napkin 1A is quickly diffused in the front-rear direction, and is absorbed and held mainly by the high basis weight portion 41 in the middle of such diffusion. Therefore, the napkin 1A of the present embodiment can quickly diffuse and absorb the excreted excreta by the diffusion / absorption action of the excretory liquid by the cooperation of the absorber 4A (absorbent core 40A) and the groove 7, It is difficult to cause side leakage and can eliminate discomfort caused by the wetness of the wearer. From the viewpoint of ensuring the operational effects of the napkin 1A, it is preferable to set the dimensions and the like of the respective parts as follows.

The ratio (S41 / S42) of the basis weight S41 of the high basis weight portion 41 and the basis weight S42 of the low basis weight portion 42 of the absorbent core 40A is preferably 1.25 or more, more preferably 3 or more, and preferably Is 10 or less, more preferably 6 or less.
The basis weight S41 of the high basis weight portion 41 is preferably 100 g / m ² or more, more preferably 150 g / m ² or more, and preferably 600 g / m ² or less, more preferably 500 g / m ² or less. The basis weight S42 of the basis weight part 42 is preferably 10 g / m ² or more, more preferably 30 g / m ² or more, and preferably 150 g / m ² or less, more preferably 100 g / m ² or less.
The ratio (T41 / T42) between the thickness T41 of the high basis weight portion 41 and the thickness T42 of the low basis weight portion 42 is preferably 1 or more, more preferably 1.5 or more, and preferably 20 or less, more preferably 10 or less.
The thickness T41 of the high basis weight portion 41 is preferably 0.5 mm or more, more preferably 1 mm or more, and preferably 10 mm or less, more preferably 8 mm or less. The thickness T42 of the low basis weight portion 42 is preferably It is 0.1 mm or more, more preferably 0.2 mm or more, and preferably 5 mm or less, more preferably 3 mm or less.

The size of the high basis weight portion 41 in a plan view as shown in FIG. 3A differs depending on the type and use of the absorbent article, but in a sanitary napkin such as the napkin 1A, the length L2 in the longitudinal direction X (See FIG. 3A) is preferably 5 mm or more, more preferably 10 mm or more, and preferably 50 mm or less, more preferably 30 mm or less, and a length L3 in the width direction Y (see FIG. 3A). ) Is preferably 3 mm or more, more preferably 5 mm or more, and 30 mm or less, more preferably 20 mm or less.
The number of high basis weight portions 41 is preferably 5 or more, more preferably 10 or more, and preferably 70 or less, more preferably 60 or less per 50 cm ² area.

The width L5 (see FIG. 3B) of the groove 7 (7X, 7Y1, 7Y2) is preferably 0.5 mm or more, more preferably 1.0 mm or more, and preferably 5.0 mm or less, more preferably 4 0.0 mm or less.
The depth L6 of the groove 7 (see FIG. 5) is preferably 0.5 mm or more, more preferably 1.0 mm or more.

In addition, although the dimension of each part of the groove | channel 7 mentioned above may be measured using a ruler etc. with the naked eye, Preferably, it measures using a digital microscope. For example, the groove 7 can be enlarged and photographed using a digital microscope VHX-1000 manufactured by KEYENCE, and the dimensions of each part can be measured. The width L5 of the groove 7 is measured at the bottom surface of the groove 7. The depth L6 of the groove 7 is obtained by measuring the cross section of the groove 7 with a digital microscope.

The material for forming each part of the napkin 1A will be described. As the top sheet 2 and the back sheet 3, various materials conventionally used in the technical field can be used without particular limitation. As the surface sheet 2, for example, a liquid-permeable sheet such as a nonwoven fabric or an apertured film can be used. As the back sheet 3, for example, a resin film that does not have moisture permeability, a resin film that has micropores and has moisture permeability, a nonwoven fabric such as a water-repellent nonwoven fabric, a laminate of these and other sheets, and the like are used. Can do. Moreover, as the side sheet | seat 5, the various things conventionally used in the said technical field can be especially used without a restriction | limiting, For example, the sheet | seat made from a water-repellent nonwoven fabric and a resin film can be used.

As an absorptive material which is a forming material of the absorptive core 40A, various materials conventionally used in the technical field can be used without particular limitation. For example, natural materials such as wood pulp, cotton, hemp and the like can be used as fiber materials. Fibers: synthetic fibers made of synthetic resins such as polyethylene and polypropylene; semi-synthetic fibers such as acetate and rayon can be used. Further, in addition to these fiber materials, water-absorbing polymers of various shapes such as particles can be used as the absorbent material.

Hereinafter, the manufacturing method of the absorbent body (absorbent core) according to the present invention (first invention) will be described by taking the above-described manufacturing method of the absorbent body 4A (absorbent core 40A) as an example. FIG. 7 shows an embodiment of a method for manufacturing the absorbent body 4A and a manufacturing apparatus used therefor. The absorber manufacturing apparatus includes a rotating drum 50 that is rotationally driven in the direction of arrow R1, a duct 60 that supplies the absorbent material 45, which is a raw material of the absorbent core 40A, to the outer peripheral surface of the rotating drum 50, and the rotating drum 50 A transfer roll 70 disposed obliquely below and rotated in the direction of arrow R2, a vacuum box 65 disposed between the duct 60 and the transfer roll 70 in the circumferential direction of the rotary drum 50, a vacuum box 65 and the rotary drum 50 and a mesh belt 75, which is a sheet-like breathable member, disposed so as to pass between the transfer roll 70 and the rotary drum 50, and a vacuum conveyor 80 disposed below the transfer roll 70. I have.

As shown in FIG. 7, the rotating drum 50 has a cylindrical shape, and receives power from a motor such as a motor, and the members forming the outer peripheral surface rotate around the horizontal axis. A space 56 capable of depressurizing the inside is formed in a non-rotating portion on the inner side (rotating shaft side) of the rotating drum 50. A known exhaust device (not shown) such as an intake fan is connected to the space 56, and the interior of the space 56 can be maintained at a negative pressure by operating the exhaust device. On the other hand, piping (not shown) capable of taking in air outside the apparatus is connected to the

spaces

57 and 58 on the inner side (rotating shaft side) of the rotating drum 50.

As shown in FIG. 8, a concave portion 51 having a shape corresponding to the shape of the absorbent core 40A to be manufactured is formed on the outer peripheral surface of the rotary drum 50. A large number of pores are formed in the bottom surface portion 52 of the recess 51, and the pores of the bottom surface portion 52 of the recess 51 absorb while the recess 51 passes over the space 56 maintained at a negative pressure. It functions as a suction hole for the conductive material 45. On the other hand, the left and right side portions of the outer peripheral surface of the rotating drum 50 in which the recess 51 is not formed are made of a frame body of the rotating drum 50 made of a metal rigid body and are non-breathable.

As shown in FIG. 8, a plurality of partition members 53 that partition the recess 51 into a plurality of regions are formed on the bottom surface 52 of the recess 51. Each partition member 53 is made of a non-breathable plate member. The inside of the recess 51 is partitioned into a plurality of regions 54 corresponding to the plurality of high basis weight portions 41 in the absorbent core 40A described above by a plurality of partition members 53. The shape of each partitioned region 54 in plan view is the same shape (rectangular shape) as that of the high basis weight portion 51 in plan view. Further, as will be described later, in order for the absorbent material to be deposited in the recess 51 beyond the height of the partition member 53 protruding from the bottom surface 52, the height of the partition member 53 protruding from the bottom surface 52. Is shorter than the depth of the recess 51.

As shown in FIG. 7, one end side of the duct 60 covers the outer peripheral surface of the rotary drum 50 positioned on the space 56 maintained at a negative pressure, and the other end side (not shown) has a fiber material introduction device. have. The fiber material introducing device includes, for example, a pulverizer that pulverizes sheet-like wood pulp into defibrated pulp and feeds the defibrated pulp (fiber material) into a duct. A water-absorbing polymer introduction part that introduces the water-absorbing polymer may be provided in the middle of the duct 60.

The transfer roll 70 has a cylindrical outer peripheral portion having air permeability, and the outer peripheral portion rotates around a horizontal axis upon receiving power from a motor such as a motor. In the non-rotating portion on the inner side (rotating shaft side) of the transfer roll 70, a space 71 that can be depressurized is formed. A known exhaust device (not shown) such as an intake fan is connected to the space 71, and the interior of the space 71 can be maintained at a negative pressure by operating the exhaust device.

The vacuum box 65 is disposed between the downstream end 61 of the duct 60 and the transfer roll 70 in the rotation direction R1 of the rotary drum 50. The vacuum box 65 has a box-like shape having upper and lower surfaces, left and right side surfaces, and a back surface, and has an opening that opens in the direction of the rotary drum 50 at a portion facing the back surface. The vacuum box 65 is connected to a known exhaust device (not shown) such as an intake fan via an exhaust pipe 61, and the inside of the vacuum box 65 can be maintained at a negative pressure by the operation of the exhaust device. .

The mesh belt 75 is a sheet-like breathable member, which is a belt-shaped breathable belt having a mesh connected in an endless manner, and is guided by a plurality of free rolls and transfer rolls 70 so as to continue a predetermined path. Move on. The mesh belt 75 is driven by the rotation of the transfer roll 70. As shown in FIG. 7, the mesh belt 75 is introduced between the vacuum box 65 and the rotary drum 50 and the transfer roll after being introduced onto the outer peripheral surface of the rotary drum 50 in the vicinity of the downstream end portion 61 of the duct 60. 70 and the rotating drum 50 are arranged so as to pass sequentially. While the mesh belt 75 passes in front of the opening of the vacuum box 65, the mesh belt 75 is in contact with the outer peripheral surface of the rotary drum 50, and the transfer roll 70 and the rotary drum 50 are closest to each other. In the vicinity of the portion, the transfer drum 70 moves away from the outer peripheral surface of the rotating drum 50.

The vacuum conveyor 80 includes an endless breathable belt 83 that is stretched between a drive roll 81 and a driven roll 82, and a vacuum box 84 that is disposed at a position facing the transfer roll 70 with the breathable belt 83 interposed therebetween. ing.

Next, a method for continuously manufacturing the absorbent body 4A (absorbent core 40A) using the above-described absorbent body manufacturing apparatus will be described. In order to manufacture the absorber 4A using the above-described absorber manufacturing apparatus, the exhaust 56 connected to the space 56 in the rotary drum 50 and the vacuum box 65 are operated to make negative pressure. . By making negative pressure in the space 56, an air flow is generated in the duct 60 to convey the absorbent material 45 to the outer peripheral surface of the rotary drum 50. Further, the rotating drum 50 and the transfer roll 70 are rotated, and the vacuum conveyor 80 is operated. Then, when the fiber material introduction device is operated to supply the fiber material into the duct 60 and further supply the water-absorbing polymer, these absorbent materials 45 ride on the air flow flowing through the duct 60 and scatter. The state is supplied toward the outer peripheral surface of the rotating drum 50.

While the portion covered with the duct 60 is being conveyed, the absorbent material (mixture of the fiber material and the water-absorbing polymer) 45 is sucked into the concave portion 51 of the rotary drum 50. The absorbent material 45 is gradually deposited on the bottom surface portion 52 of each partition region 54 of the recess 51, and finally, the protruding height from the bottom surface portion 52 of the partition member 53 is set as shown in FIG. It accumulates in the recessed part 51 beyond. In the deposit 46 obtained in this way, the part (partition member corresponding part) 46a formed by depositing the absorbent material 45 on the partition member 53 has a relatively small amount of deposited absorbent material 45, and other parts. (Partition region corresponding part) 46b has a relatively large amount of deposited absorbent material 45, and the entire deposit 46 has an uneven structure.

Then, when the rotary drum 50 rotates and the concave portion 51 comes to a position opposite to the vacuum box 65, the deposit 46 in the concave portion 51 is sucked to the mesh belt 75 by suction from the vacuum box 65. . In this state, the deposit 46 in the recess 51 is conveyed to a position immediately before the closest portion between the transfer roll 70 and the rotary drum 50, and the mesh belt 75 is sucked from the transfer roll 70 side near the closest portion. The mold is released from the concave portion 51 while being sucked on the transfer roll 70 and moves onto the transfer roll 70.

Thus, the deposit 46 transferred onto the transfer roll 70 together with the mesh belt 75 is transported to the transfer section (the lowermost end portion of the transfer roll 70) with the vacuum conveyor 80 while being adsorbed by the mesh belt 75 on the transfer roll 70. Then, in the transfer section, the vacuum box 84 moves to the vacuum conveyor 80 by suction.

In the absorbent body manufacturing apparatus of the present embodiment, as shown in FIG. 7, the first core wrap sheet 47 made of tissue paper or water-permeable nonwoven fabric is placed on the vacuum conveyor 80 before the deposit 46 is placed. Is introduced, and the deposit 46 moves onto the first core wrap sheet 47. Further, after the second core wrap sheet 48 is introduced on the upper surface side of the deposit 46, the deposit 46 covered with both the

core wrap sheets

47, 48 is cut at a predetermined interval to obtain one napkin. The absorber precursor 49 cut to the minute dimension is obtained. In addition, in FIG.1 and FIG.2, illustration of both the

core wrap sheets

47 and 48 is abbreviate | omitted.

And in the absorber manufacturing apparatus of this embodiment, the absorber precursor 49 obtained in this way is compressed by the pressurizing means 90, and the thickness of the deposit 46 which comprises the absorber precursor 49 is actively reduced. Thus, the intended absorber 4A (absorbent core 40A) is obtained. As shown in FIG. 7, the pressurizing means 90 includes a pair of

rolls

91 and 92 with smooth surfaces, and can pressurize an object to be pressed introduced between the

rolls

91 and 92 from the upper and lower surfaces to compress in the thickness direction. It is configured.

FIG. 10 schematically shows the state of the deposit 46 before and after compression. The left diagram across the arrow of FIG. 10 shows the deposit 46 before compression, the right diagram shows the deposit 46 after compression (absorbent core 40A), and in both the left and right diagrams, the upper stage shows the deposit 46 ( The cross-sectional view of the absorbent core 40A), the lower part shows a perspective view of the deposit 46. When the deposit 46 is compressed by the pressurizing means 90, the partition region corresponding portion 46b (convex portion) having a relatively large absorbent material and a large thickness has a partition member corresponding portion 46a having a relatively small absorbent material and a small thickness. It is compressed more strongly than (non-convex part or concave part). As a result, the partition region corresponding portion 46b in the deposit 46 becomes a high basis weight portion 41 having a relatively high density in the absorbent core 40A, and the partition member corresponding portion 46a in the deposit 46 is relatively in the absorbent core 40A. It becomes a low basis weight portion 42 having a low density.

According to the method for manufacturing an absorbent body described above, the relatively high density high basis weight portion 41 and the relatively low density low basis weight portion 42 are alternately formed in both the longitudinal direction X and the width direction Y. The absorbent core 40 A having the uneven structure can be efficiently manufactured. The ratio (D41 / D42) of the density D41 of the high basis weight portion 41 and the density D42 of the low basis weight portion 42 is preferably 1.5 to 20, and more preferably 2.0 to 10. The density of the high basic weight part 41 and the low basic weight part 42 is measured as follows.

<Density measurement method>
The density of the high basis weight portion 41 was calculated by dividing the weight of the high basis weight portion 41 by the volume (thickness × length × width) of the high basis weight portion 41. The density of the low basis weight portion 42 was calculated by dividing the weight of the low basis weight portion 42 by the volume (thickness × length × width) of the low basis weight portion 42. The “thickness” used for calculating the volume of each of the high basis weight portion 41 and the low basis weight portion 42 was measured as follows. An acrylic plate having a length of 37 mm, a width of 37 mm, and a thickness of 3 mm is placed on the absorbent core 40A to be measured, and the thickness of the high basis weight portion 41 of the absorbent core 40A is determined by a non-contact type laser displacement meter manufactured by KEYENCE ( The thickness of the low basis weight portion 42 was measured using a laser head LK-G30 and a displacement meter LK-GD500), and the cross section of the absorbent core 40A (see FIG. 2) using a microscope VHX-1000 manufactured by KEYENCE. It was measured by observing the cross section as shown. The “weight” of each of the high basis weight portion 41 and the low basis weight portion 42 was measured as follows. A razor manufactured by FEATHER (feather shaving blade S single blade) is pressed against the absorbent core 40A to be measured to cut out the high basis weight portion 41 and the low basis weight portion 42, respectively, and the cut out high basis weight portion 41 and the low basis weight. The weight of each part 42 was measured using an electronic balance (Electronic balance GR-300 manufactured by A & D, accuracy: 4 digits after the decimal point).

The present invention (first invention) is not limited to the above embodiment. For example, in the above-described embodiment, the low basis weight portion 42 is unevenly distributed on the skin contact surface 4a side in the thickness direction of the absorbent core 40A. It may be unevenly distributed on the contact surface 4b side, or may be unevenly distributed in a substantially central portion between the skin contact surface 4a and the non-skin contact surface 4b. In the cross-sectional view of the absorbent core 40A, when the low basis weight portion 42 is unevenly distributed on the non-skin contact surface 4b side in the thickness direction of the absorbent core 40A, the non-skin contact surface 4b is substantially uneven. It is almost flat (no irregularities and flat).

Moreover, the low basic weight part 42 (42X, 42Y) of planar view linear form is formed in the absorptive core 40A whole as shown in FIG. 3 (so that the front part 12, the excretory part opposing part 11, and the rear part 13 may be straddled). A region between the at least a pair of grooves 7 and 7 (

vertical grooves

7X and 7X) and its vicinity (groove peripheral region) in the excretory part facing part 11 (of the excretion part facing part 11). It suffices if it is formed in the width direction inward part. Moreover, the planar view shape of the low basic weight part 42 is not restrict | limited to linear form like the said embodiment, Curve shape may be sufficient.

Moreover, in the absorbent core 40A, the high basis weight portions 41 may be arranged in a staggered manner. That is, a large number of high basis weight portions 41 are arranged at predetermined intervals in the longitudinal direction X to form a high basis weight portion row, and a plurality of high basis weight portion rows are arranged at predetermined intervals in the width direction Y. In this case, the pitches of the high basis weight portions 41 in the high basis weight portion rows adjacent to each other may be shifted. In other words, the high basis weight portion 41 is adjacent to the high basis weight portion 41 when projected in a direction (width direction Y) perpendicular to the high basis weight portion row in the predetermined high basis weight portion row. You may arrange | position so that it may not correspond with the projection image of the basic weight part 41. FIG. By doing in this way, the groove | channel 7 (lateral groove 7Y1 and 7Y2) extended in the width direction Y will be on the outward of the longitudinal direction X of the napkin 1A by planar view like the said embodiment (refer FIG. 3). Even if it is not formed so as to include a horizontally long shape that is convexly curved (for example, even if the horizontal grooves 7Y1, 7Y2 are formed in a straight line extending in the width direction Y), the horizontal grooves 7Y1, 7Y2 It can prevent that the quantity part 42 corresponds completely.

Further, as described above, the groove 7 is sandwiched between the two high

basis weight portions

41, 41 and the two high

basis weight portions

41, 41 arranged in the longitudinal direction X or the width direction Y of the napkin 1A. As a method of forming continuously with the individual low basis weight portions 42, in other words, as a method of not completely matching the groove 7 and the low basis weight portion 42 of the absorbent core 40A, as in the above embodiment, In addition to the method of forming the groove 7 so as to include a shape curved convexly toward the outside of the napkin 1A in plan view and forming the low basis weight portion 42 in a straight line shape in plan view, a) relative A method of arranging a relatively small sized low basis weight portion 42 around a large sized high basis weight portion 41, and b) a plan view shape as a high basis weight portion 41 combined with the low basis weight portion 42. One that uses one or more of the five or more polygonal high basis weight portions 41 alone or in combination of two or more. C) The angle formed by the direction in which the grooves 7 are formed (the direction in which the linear grooves 7 extend) and the direction in which the low basis weights are formed (the direction in which the linear low basis weights extend) is set to 30 to 60 °. Method, etc.

In addition, a sanitary napkin is given as one example of application of the absorbent article of the present invention (first invention), but the present invention can also be applied to disposable diapers, incontinence pads, panty liners, and the like.

Hereinafter, the absorbent article of the present invention (second invention) will be described with reference to the drawings based on a sanitary napkin which is a preferred embodiment thereof. As shown in FIGS. 12 and 13, the napkin 1 B of the present embodiment includes a top sheet 2 disposed on the skin contact surface side, a back sheet 3 disposed on the non-skin contact surface side, and both sheets 2. It has the absorber 4B interposed between 3 and is vertically long (a shape long in one direction). As shown in FIG. 12, the napkin 1 B is disposed on the abdomen side of the wearer with respect to the excretion part facing part 11 disposed opposite to the excretion part (vaginal opening) of the wearer at the time of wearing and the excretion part facing part 11 at the time of wearing. The front portion 12 and the rear portion 13 disposed on the back side of the wearer rather than the excretory portion facing portion 11 at the time of wearing are provided in the longitudinal direction X. The excretory part opposing part 11 is a part which has a pair of

wing parts

6 and 6 on either side mentioned later. The pair of

wing parts

6 and 6 are parts that are wound around the crotch part (crotch part) of the underwear when the napkin 1B is fixed to the underwear such as shorts. In addition, when the absorbent article (sanitary napkin) of the present invention (second invention) does not have a wing part, the excretory part facing part of the sanitary napkin has a so-called short length of 25 cm or less in the product longitudinal direction. The time / daytime napkin is the central part (second area from the front) when the napkin is divided into three equal parts in the longitudinal direction to form the front part, the central part, and the rear part. In the so-called long daytime and nighttime napkins that exceed this, it is the second region from the front (the third region from the back) when these napkins are equally divided into four in the longitudinal direction.

As shown in FIG. 13, the top sheet 2 covers the entire skin contact surface 4a of the absorbent body 4B, and further extends outward in the width direction Y from the left and right side edges along the longitudinal direction X of the absorbent body 4B. In addition, the back sheet 3 covers the entire area of the non-skin contact surface 4b of the absorbent body 4B, and further extends outward in the width direction Y from both side edges of the absorbent body 4B. Further, the top sheet 2 and the back sheet 3 also extend outward in the longitudinal direction X from the front end and the rear end in the longitudinal direction X of the absorbent body 4B. They are joined together by a known joining means such as an ultrasonic seal.

As shown in FIGS. 12 and 13, a pair of

side sheets

5, 5 are disposed over the entire length in the longitudinal direction X of the napkin 1 B on both left and right side portions along the longitudinal direction X of the napkin 1 B. The side sheet 5 has an inner side portion in the width direction Y joined to the skin contact surface 2a of the surface sheet 2 by a known joining means, and an outer side portion of the absorbent body 4B. It extends outward in the width direction Y from the side edge along the longitudinal direction X, and the extension part is joined to the extension part from the side edge of the absorber 4B in the back sheet 3 by a known joining means. Yes. The back sheet 3 and the side sheet 5 have the maximum length extending outward in the width direction Y from the side edge of the absorber 4B in the excretory part facing part 11, and the maximum extension part A pair of

wing portions

6 and 6 are formed.

The non-skin contact surface of the napkin 1B (the non-skin contact surface 3b of the back sheet 3) is directed to the clothing side such as the crotch portion of the shorts when worn. The non-skin contact surface 3b is provided with an adhesive portion (not shown) for fixing the napkin 1B to a crotch portion of underwear such as shorts. Further, the non-skin contact surfaces (non-skin contact surface 3b of the back sheet 3) of the pair of

wing portions

6 and 6 are adhesive portions (not shown) for fixing to the outer surface (non-skin contact surface) of the shorts. Z). These adhesive portions are provided by applying a hot melt adhesive to a predetermined location, and are covered with a release sheet (not shown) made of a film, nonwoven fabric, paper, or the like before the napkin 1B is used.

The absorbent body 4B includes an absorbent core 40B including an absorbent material (fiber material such as pulp, water-absorbing polymer, etc.). The absorbent body 4B in the present embodiment is configured by covering the absorbent core 40B with a core wrap sheet (not shown) made of tissue paper or a water-permeable nonwoven fabric. The absorbent core 40B may be composed of only a fiber material such as pulp together with the high basis weight portion 41 and the low basis weight portion 42, which will be described later, or includes the fiber material and a water-absorbing polymer. In the latter case, the water-absorbing polymer may be uniformly mixed between the fiber materials, or may include a fiber layer mainly composed of the fiber material and a polymer layer mainly composed of the water-absorbing polymer, and The polymer layer may be sandwiched between the two fiber layers. The top sheet 2 and the absorber 4B, and the absorber 4B and the back sheet 3 are joined to each other by a pattern-coated adhesive (hot melt adhesive or the like) such as dots, spirals, and stripes. Also good.

The absorber 4B has a high basis weight portion 41 having a relatively high basis weight, and a low basis weight portion 42 having a relatively low basis weight adjacent to the high basis weight portion 41. In this embodiment, as shown in FIGS. 13 and 14, the absorbent core 40 B constituting the absorbent body 4 B has a relatively small amount of the high basis weight portion 41 and the absorbent material having a relatively large amount of the absorbent material. The low basis weight part 42 (42X, 42Y) has a concavo-convex structure formed alternately in a predetermined direction (longitudinal direction X and width direction Y). As shown in FIG. 13, the apparent thickness of the absorbent core 40B is uniform. More specifically, as shown in FIG. 14, the absorbent core 40 B has a linear (continuous linear) low basis weight portion 42 X extending along the longitudinal direction X and a linear shape extending along the width direction Y. A plurality of (continuous linear) low basis weight portions 42Y are respectively formed, and the low basis weight portion 42 is formed in a lattice shape as a whole, and parts (parts) defined by these linear low

basis weight portions

42X and 42Y ( The position of the grid eye) is the high basis weight portion 41. Each of the plurality of linear low basis weight portions 42X is formed to extend over the entire length in the longitudinal direction X of the absorbent core 40B, and each of the plurality of linear low basis weight portions 42Y is absorbent. The core 40B is formed to extend over the entire length in the width direction Y. Each of the plurality of high basis weight portions 41 has a rectangular shape in plan view as shown in FIG.

The low basis weight part 42 (42X, 42Y) is unevenly distributed on the skin contact surface 4a side in the thickness direction T of the napkin 1B (absorbent core 40B), as shown in FIGS. And since the low basic weight part 42 is unevenly distributed in the skin contact surface 4a side of the thickness direction T in this way, the high basic weight part 41 is the opposite side to the skin contact surface 4a, ie, thickness direction. It protrudes to the non-skin contact surface 4b side of T. Therefore, in the absorbent core 40B, the skin contact surface 4a (the surface facing the top sheet 2) is substantially flat with no irregularities except for the formation portion of the groove 7 to be described later. The skin contact surface 4b (opposite surface to the back sheet 3) has a high basis weight portion 41 (convex portion) formed to protrude and a low basis weight portion 42 (non-convex portion) located between the high

basis weight portions

41, 41. Or it has an unevenness due to the recess).

The absorbent core 40B according to the present embodiment (the concavo-convex structure) has an external appearance on one surface side of the absorbent material molded into a thin plate shape, and a plurality of absorbent parts having a rectangular shape in plan view made of the absorbent material are mutually connected. It may seem similar to the absorber described in Patent Documents 2 and 3 (absorber formed by fixing a plurality of absorbers to a sheet) in that it is configured to be spaced apart. However, as will be described later, the absorbent core 40B according to the present embodiment is manufactured by molding an absorbent material so as to have the uneven structure, and includes a high basis weight portion 41 and a low basis weight portion. 42 is integrated without using a bonding means such as an adhesive or heat-sealing, and is formed so as not to have a boundary (boundary between the high basis weight portion 41 and the low basis weight portion 42) by the same material. On the other hand, the absorbers described in

Patent Documents

2 and 3 are manufactured by fixing a plurality of the absorbing parts to the sheet separately from the absorbing parts, and the absorbing parts And the sheet are joined to each other via a joining means and have a boundary between the absorbing portion and the sheet, and they are different in this respect. And by the difference of such a structure, while the high basic weight part 41 and the low basic weight part 42 which concern on this embodiment have the continuity in which a liquid can move smoothly, patent document 2 And the absorbent portion and the sheet in the absorbent body according to 3, since there is an interface composed of joining means between them (boundary), liquid diffusion easily occurs at the boundary portion, and the liquid can move smoothly. It is hard to say that it has continuity.

As shown in FIGS. 12 to 14, the napkin 1B has a groove 7 in which the top sheet 2 and the absorbent body 4B (absorbent core 40B) are recessed integrally. The groove 7 is a space (a portion where the material for forming the napkin 1B does not exist) defined by a bottom wall portion 71 and a side wall portion 72 described later. As shown in FIG. 14A, the groove 7 includes a pair of left and right vertical grooves 7 X and 7 X that continuously extend in the longitudinal direction X, and two horizontal grooves 7 Y 1 and 7 Y 2 that extend continuously in the width direction Y. These four grooves are connected at the respective end portions to form an annular groove as a whole. The pair of

longitudinal grooves

7X and 7X extend over the entire length in the longitudinal direction X of the excretory part-facing part 11 at the left and right side parts along the longitudinal direction X of the absorbent core 40B, and further, the front part 12 and the rear part 13 also extends to each. The lateral groove 7Y1 is formed in the front part 12, and the lateral groove 7Y2 is formed in the rear part 13, respectively. Both lateral grooves 7Y1 and 7Y2 are formed to include a horizontally long shape that is convexly convex outward in the longitudinal direction X in plan view, and the tops of the protrusions of both lateral grooves 7Y1 and 7Y2 have a width of Located in the center of the direction Y.

As shown in FIG. 14, the groove 7 (7X, 7Y1, 7Y2) has a shallow groove portion 73 that is recessed relatively shallow and a deep groove portion 74 that is recessed relatively deeply. The groove 7 forms a continuous line as a whole by the shallow groove portion 73 and the deep groove portion 74 being alternately connected along the length direction of the groove 7. The groove 7 is formed by squeezing the absorbent core 40B together with the top sheet 2 by embossing, and the shallow groove 73 is squeezed relatively weakly in the embossing, and the bottom depth (skin of the bottom wall 71) The depth from the contact surface 2a is a shallow portion, and the deep groove portion 74 is a portion where the bottom portion depth is deeply squeezed relatively strongly in the embossing. The plan view shapes of the shallow groove portion 73 and the deep groove portion 74 are not particularly limited, and may be a rectangle, a square, a rhombus, a circle, a cross, or the like.

The groove 7 (7X, 7Y1, 7Y2) can be formed in accordance with an ordinary method by embossing such as embossing with or without heat, or ultrasonic embossing. That is, in the manufacturing process of the napkin 1B, after supplying the surface sheet 2 on one surface of the absorber 4B (absorbent core 40B having an uneven structure), a predetermined portion is moved from the surface sheet 2 side to the absorber 4B side by embossing. The groove 7 can be formed in the predetermined portion by pressing (squeezing) in a concave shape. In the groove 7, the top sheet 2 and the absorber 4B are integrated by heat fusion or the like.

The groove 7 is formed across the high basis weight part (convex part) 41 and the low basis weight part (non-convex part or concave part) 42. More specifically, the groove 7 includes two high basis weight portions (convex portions) 41 and 41 adjacent to each other in a predetermined direction and one low basis weight portion (between both high basis weight portions 41 and 41). (Non-convex part or concave part) 42 is formed. In the present embodiment, as shown in FIG. 14A, with respect to the longitudinal direction X, a pair of longitudinal grooves 7X, which are a part of the grooves 7, in the excretory part facing part 11 that is a part that directly receives excretion fluid. Each of 7X is formed continuously with two high

basis weight portions

41, 41 adjacent to each other in the longitudinal direction X and one low basis weight portion 42Y positioned therebetween, and absorbs continuously with the longitudinal direction X. It is formed so as to straddle the irregularities of the core 40B. Regarding the width direction Y, in the front portion 12, the lateral groove 7Y1, which is a part of the groove 7, is adjacent to the two high

basis weight portions

Such a positional relationship between the groove 7 and the high basis weight portion 41 and the low basis weight portion 42 is to make sure that the excretory fluid absorption / diffusion action according to the present invention (second invention) to be described later is achieved. In particular, as described above, the groove 7 (vertical groove 7X) is formed across the high basis weight portion (convex portion) 41 and the low basis weight portion (non-convex portion or concave portion) 42 in the longitudinal direction X. This is important because it relates to the effect of preventing leakage (so-called side leakage) to the outside due to movement of the excretory fluid in the width direction Y. Therefore, in the present embodiment, as a device for more reliably obtaining such an arrangement over the unevenness of the vertical groove 7X, “a linear (continuous linear) shape in which the napkin 1B extends in the longitudinal direction X” is used. It includes a low basis weight portion 42X, and the longitudinal groove 7X extending in the longitudinal direction X has a portion whose length direction is different from that of the linear low basis weight portion 42X. " . That is, in the present embodiment, as described above, the low basis weight portion 42X is formed in a linear shape extending in the longitudinal direction X in plan view, and the vertical groove 7X is shown in FIG. As shown in FIG. 2, the both sides along the longitudinal direction X of the napkin 1B in the excretory part facing part 11 include a vertically long shape (curved part) curved convexly outward in the width direction Y of the napkin 1B. It is formed so that the curve which consists of this curved part may be included as a part from which the length direction differs from the linear low basic weight part 42X. As described above, the low basis weight portion 42X of the absorbent core 40B is formed in a linear shape that completely coincides with the longitudinal direction X of the absorbent core 40B, while the longitudinal groove 7X is not completely in the longitudinal direction X. By forming it so as to have a curved portion that does not match (partially matches), at least the curved portion of the longitudinal groove 7X is completely the same as the linear low basis weight portion 42X extending in the longitudinal direction X in plan view. The vertical grooves 7 X are easily formed so as to straddle the high basis weight portion 41 and the low basis weight portion 42 in the longitudinal direction X without matching.

15 to 17 schematically show the cross section of the groove 7 in each part of the absorbent core 40B. The groove 7 (7X, 7Y1, 7Y2) is defined by a bottom wall portion 71 and a side wall portion 72 standing from the bottom wall portion 71, as shown in FIGS. 15 to 17, for the sake of easy explanation, the illustration of the shallow groove portion 73 and the deep groove portion 74 is omitted, and the bottom wall portion 71 is described as a substantially flat portion having no step in the length direction of the groove 7. However, in actuality, the shallow groove portion 73 and the deep groove portion 74 are different in the position of the bottom wall portion in the thickness direction of the absorbent core. Nearly, the bottom wall portion 71 of the deep groove portion 74 is relatively far from the surface sheet 2, so that the actual bottom wall portion 71 has a shallow groove portion 73 at a relatively high position and a deep groove portion at a relatively low position. There is a step corresponding to 74

In the present embodiment, the high basis weight portion 41 has a higher density than the low basis weight portion 42, and there is a density gradient in the high basis weight portion 41, the low basis weight portion 42, the groove 7, and the vicinity thereof. Exists. That is, the density of the parts indicated by reference signs A to E in FIG. 14B and FIGS. 15 to 17 is A ≦ B << C << E, more preferably A << B << C <D <E. The density decreases as the distance from the groove 7 (vertical groove 7X) decreases (site A), and the density increases as the distance from the groove 7 increases (area B and / or C). In the groove 7 (bottom wall portion 71), The density is maximized (sites D and E). Moreover, about the groove | channel 7 (bottom wall part 71), the site | part D in the low basic weight part 42 (42Y) is along the groove | channel 7 because the density is made a little low compared with the site | part E in the high basic weight part 41. It is more preferable that the density of the liquid is higher than that of the part C in the vicinity of the groove 7 in the high basis weight portion 41. The density gradient that the density increases as it approaches the groove 7 is mainly caused by the formation of the groove 7 by the embossing process described above (squeezing of the absorbent core 40B). Also exists. A characteristic of the present embodiment regarding the density gradient is that B << C, that is, the high basis weight portion 41 is higher in density than the low basis weight portion 42 in the entire absorbent core 40B. This means that this relationship is also established in the vicinity. The term “in the vicinity of the groove” means the side wall portion 72 (see FIGS. 15 to 17) that defines the groove 7 and the vicinity thereof. It means a portion within 5 mm outside the direction perpendicular to the vertical direction (width direction of the groove 7).

As described above, the portions B and C in the vicinity of the groove 7 (vertical groove 7X) have the same distance from the groove 7, but the portion C located in the high basis weight portion 41 has a lower basis weight. The reason why the density is higher than the portion B located in the amount portion 42 (42Y) is that the high basis weight portion 41 is more absorbent than the low basis weight portion 42 before the groove 7 is formed by pressing the absorbent core 40B. This is because there are many materials and the density is high. That is, the absorbent core 40B according to this embodiment, as will be described later, obtains a deposit having an uneven structure by depositing an absorbent material so as to have a high basis weight portion 41 and a low basis weight portion 42. When the entire deposit is produced by compressing the entire deposit with a uniform compressive force using a pressure roll or the like, in such a compression process, the high basis weight portion 41 as the convex portion is more non-convex or as the concave portion. Since it compresses more strongly than the low basic weight part 42, the high basic weight part 41 (part C) becomes high density compared with the low basic weight part 42 (part B). Thus, there is a difference in density between the part B and the part C before the formation of the groove 7, and when the groove 7 is formed in the part B and the part C by pressing, the side wall part 72 that defines the groove 7. And this density difference is reflected in the vicinity thereof, and as a result, B << C with respect to the density.

Further, in the low basis weight portion 42 in the present embodiment, as shown in FIG. 15, the side wall portion 72 (part B, “near the groove”) that defines the groove 7 (vertical groove 7 X) is the side wall portion 72. The basis weight is lower than that of the portion A (a portion that is further away from the groove than “the vicinity of the groove”) that is located farther from the groove 7 (vertical groove 7X). Such a basis weight difference resulting from the distance from the groove 7 in the low basis weight portion 42 is due to the formation of the groove 7 by embossing (squeezing of the absorbent core 40B). That is, in the process of forming the groove 7 by embossing, the low basis weight part 42 is finally pushed into a concave shape with the part (part D) that becomes the bottom wall part 71 defining the groove 7 as a pushing center. By pressing the low basis weight portion 42, the vicinity of the indentation center (part B) is selectively stretched to reduce the basis weight, while the part farther from the indentation center (part A) is substantially reduced. It is not stretched (basis weight does not change), and as a result, the vicinity (part B) of the indentation center becomes a side wall part 72 having a lower basis weight than part A. Thus, when the side wall part 72 which defines the groove | channel 7 in the low basic weight part 42 is a lower basic weight than the part further away from the groove | channel 7, the transport amount of the excretion liquid by the side wall part 72 will fall. Therefore, as will be described later, the excretory fluid is effectively prevented from moving outward in the width direction Y of the napkin 1B over the groove 7. From the viewpoint of more surely exhibiting such operational effects in the low basis weight portion 42, the side wall portion 72 in the low basis weight portion 42 [in the vicinity of the groove 7 (from the outer surface of the side wall portion 72 to the width direction of the groove 7 is 5 mm). In the low basis weight portion 42, a portion that is located farther from the groove 7 than the side wall portion 72 (a portion that is 5 mm or more away from the outer surface of the side wall portion 72 in the width direction of the groove 7). ) Is the basis weight, the ratio of both basis weights (W1 / W2) is preferably 1.1 to 15, more preferably 1.2 to 3.0.

Thus, the napkin 1B of this embodiment has the absorber 4B (absorbent core 40B) having the high basis weight part 41 and the low basis weight part 42 adjacent thereto, and the groove 7 has these high basis weights. By being formed across the portion 41 and the low basis weight portion 42, the absorption / diffusion action of the excretory fluid described below functions, whereby the excretory fluid such as menstrual blood is reduced depending on the amount thereof. It can be absorbed and diffused quickly. The absorption / diffusion action of the excretory fluid in the napkin 1B of the present embodiment will be described with reference to FIG. 14 (b). The excretory fluid W such as menstrual blood excreted by the wearer of the napkin 1B is normally opposed to the excretory part. It is received at the center of the width direction Y of the portion 11 and moves in the width direction Y from the skin contact surface (skin contact surface 2a of the topsheet 2) toward the groove 7 (vertical groove 7X), for example, FIG. In (b), various constituent members (surface sheet) of the napkin 1B from the part A (near the central part in the width direction Y of the excretory part facing part 11) toward the part B (near the groove 7 in the low basis weight part 42). 2 and the absorbent core 40B). As described above, since there is a density difference between the part B and the part C and the density is B <C, the excretory liquid W that has reached the part B is groove 7 in the high basis weight part 41 due to capillary force. It is easy to move to the part C in the vicinity of, and it is difficult to stay in the part B. Thus, the excretory liquid W moves in the front-rear direction of the napkin 1B along the groove 7 in the vicinity of the groove 7 and inward in the width direction Y than the groove 7, and quickly in the longitudinal direction X from the excretory part facing part 11. To spread.

basis weight parts

41, 41 but as a part of the absorbent core 40B (low basis weight part 42), the excretion fluid is retained. It has a function. Therefore, the amount of the excretory fluid W is large, and the moving speed of the excretory fluid W from the site A to the site B is higher than the moving speed of the excreted fluid W from the site B to the site C (diffusion rate in the longitudinal direction X). Even when it is fast, the excretory fluid can be temporarily held at the site B. Therefore, the site D (the groove 7 in the low basis weight portion 42 is defined outside the site B in the width direction Y of the napkin 1B). A large amount of excretory liquid is prevented from moving to the bottom wall portion 71) at the same time. As a result, the excretory liquid W moves over the groove 7 to the outside in the width direction Y of the napkin 1B and leaks laterally. It is prevented that it leads to. Further, as described above, the portion B has a lower basis weight than the portion A, and the excretion of the portion B is reduced when the transport amount of the excretory liquid is reduced due to the low basis weight. The decrease in the liquid transporting ability also contributes to suppressing the movement of the liquid from the part B to the part D and thus preventing side leakage.

The excretory liquid W is quickly absorbed and held by the high basis weight portion 41 while moving from the portion B to the portion C in the vicinity of the groove 7 and inward in the width direction Y from the groove 7. As shown in FIG. 17, the part exceeding the absorption capacity of the part E is located in the part E (the bottom wall part 71 defining the groove 7 in the high basis weight part 41) located outside the part C in the width direction Y. Moving. The site | part E is the site | part compressed most at the time of formation of the groove | channel 7 (at the time of pressing), and since the density is overwhelmingly high compared with the site | part C adjacent to the width direction Y, the site | part E from the excretion liquid W site Therefore, it is unlikely that the excretion liquid W moves beyond the groove 7 to the outside in the width direction Y of the napkin 1B. This is the same as the relationship between the part B and the part D in the low basis weight portion 42 described above. The excretion fluid W that has moved to the site E via the site C passes through the groove 7 without leaking to the outside of the groove 7, and is adjacent to the site D (the bottom wall that defines the groove 7 in the low basis weight portion 42. Part 71) and further to another part E adjacent thereto. Thus, the excretory fluid W moving in the groove 7 is absorbed and held mainly by the high basis weight portion 41 during the movement.

As described above, in the napkin 1B of the present embodiment, the excreted liquid excreted in the central portion in the width direction Y of the excretory part facing part 11 is closer to the longitudinal groove 7X and the longitudinal groove 7X than the longitudinal groove 7X. In both of the portions located inward in the width direction Y, the napkin 1B is quickly diffused in the front-rear direction, and is absorbed and held mainly by the high basis weight portion 41 in the middle of such diffusion. Therefore, the napkin 1B of the present embodiment can quickly diffuse and absorb the excreted excreta by the diffusion and absorption action of the excretory liquid by the cooperation of the absorber 4B (absorbent core 40B) and the groove 7, It is difficult to cause side leakage and can eliminate discomfort caused by the wetness of the wearer.

And in the napkin 1B of this embodiment, the structure of the groove | channel 7 is devised and the softness | flexibility is heightened on the premise of the expression of the spreading | diffusion / absorption effect | action of excretion liquid by cooperation with such an absorber 4B and the groove | channel 7 like this. Thus, the fit of the napkin 1B to the wearer's body is enhanced. The device on the structure of the groove 7 is a structure in which the shallow groove portion 73 is longer in the length direction of the groove than the deep groove portion 74. That is, taking the vertical groove 7X extending in the longitudinal direction X as an example, as shown in FIG. 18A, the length L8 of the shallow groove 73 in the longitudinal direction X of the vertical groove 7X is the same as that of the deep groove 74. It is longer than the length L9 in the length direction X. The relationship between the length of the shallow groove portion 73 and the deep groove portion 74 is the same for the lateral groove 7Y.

As described above, the shallow groove portion 73 is a low density portion that is relatively weakly squeezed during embossing when the groove 7 is formed, and the deep groove portion 74 is a high density that is squeezed relatively strongly during the embossing. In this case, the length L9 of the high-density deep groove portion 74 is longer than the length L8 of the low-density shallow groove portion 73, and the proportion of the deep groove portion 74 in the groove 7 increases (that is, the shallow groove portion 73 When the proportion of the groove 7 decreases, the groove 7 is hardened as a whole in addition to the influence in the direction in which the groove 7 extends due to the formation of the groove. Difficult to fit. On the other hand, the deep groove part 74 plays an important role in the structural stability of the groove 7 and preventing excretion fluid from moving beyond the groove 7 in the width direction Y of the napkin 1B (lateral leakage). If the ratio of the deep groove portion 74 in the groove 7 decreases (that is, the ratio of the shallow groove portion 73 increases), the side leakage prevention property by the groove 7 may be reduced.

FIG. 18 (b) and FIG. 18 (c) show such a trade-off relationship between the flexibility (fitness) in the groove and the side leakage prevention property. As shown in FIGS. 18B and 18C, the absorbent core 40B ′ having a uniform basis weight without a high basis weight portion and a low basis weight portion has a shallow groove portion 73 and a deep groove portion 74. When the groove 7 (vertical groove 7X) is formed, the length in the groove length direction X is made equal between the shallow groove portion 73 and the deep groove portion 74 as shown in FIG. 18B (L8 = L9). ) And the vertical groove 7X becomes hard and disadvantageous in terms of flexibility (fitness), while the side leakage prevention property works advantageously, the excretory fluid W exceeds the vertical groove 7X in the width direction Y. It is difficult to move outward, and it is easier to move along the longitudinal groove 7X inward in the width direction Y than the longitudinal groove 7X. As shown in FIG. 18 (c), if L8> L9, the flexibility (fitness) of the vertical groove 7X increases as the proportion of the low-density shallow groove 74 occupying the vertical groove 7X increases. Although it is improved over the form shown in FIG. 18 (b), it works against the side leakage prevention, so as shown by the symbol W1 in FIG. 18 (c), the excretory fluid exceeds the longitudinal groove 7X and the napkin 1B. The risk of moving outward in the width direction Y increases.

On the other hand, in this embodiment, as an absorber (absorbent core) in which the groove 7 is formed, as described above, the high basis weight portion 41 and the low basis weight portion 42 adjacent thereto are provided. Regardless of the length relationship between the shallow groove portion 73 and the deep groove portion 74, the absorbent body 4 B (absorbent core 40 B) exhibiting an excellent diffusion / absorption action on the excretory fluid is employed, and the periphery of the groove 7 described above. Therefore, it is possible to determine the size relationship from the viewpoint of improving the flexibility (fitness) of the groove 7, and accordingly, “the shallow groove portion 73 is the deep groove portion 74. The configuration in which the length in the length direction of the groove is longer than that in the case can be adopted, thereby enhancing the flexibility (fitness) of the napkin 1B. The ratio (L8 / L9) of the length L8 (see FIG. 18A) of the shallow groove 73 to the length L9 of the deep groove 74 (see FIG. 18A) in the length direction. Is preferably 1.2 to 18, more preferably 1.2 to 4.0. Further, the length L8 of the shallow groove portion 73 in the length direction of the groove is preferably 1.2 to 18.0 mm, and more preferably 1.2 to 4.0 mm.

From the viewpoint of ensuring the operational effects of the napkin 1B described above, the dimensions and the like of each part are preferably set as follows.
The ratio (S41 / S42) of the basis weight S41 of the high basis weight portion 41 and the basis weight S42 of the low basis weight portion 42 of the absorbent core 40B is preferably 1.25 or more, more preferably 3 or more, and preferably Is 10 or less, more preferably 6 or less.
The basis weight S41 of the high basis weight portion 41 is preferably 100 g / m ² or more, more preferably 150 g / m ² or more, and preferably 600 g / m ² or less, more preferably 500 g / m ² or less. The basis weight S42 of the basis weight part 42 is preferably 10 g / m ² or more, more preferably 30 g / m ² or more, and preferably 150 g / m ² or less, more preferably 100 g / m ² or less.
The ratio (T41 / T42) between the thickness T41 of the high basis weight portion 41 and the thickness T42 of the low basis weight portion 42 is preferably 1 or more, more preferably 1.5 or more, and preferably 20 or less, more preferably 10 or less.
The thickness T41 of the high basis weight portion 41 is preferably 0.5 mm or more, more preferably 1 mm or more, and preferably 10 mm or less, more preferably 8 mm or less. The thickness T42 of the low basis weight portion 42 is preferably It is 0.1 mm or more, more preferably 0.2 mm or more, and preferably 5.0 mm or less, more preferably 3.0 mm or less.

The width L1 (see FIG. 14 (a)) of the low basis weight portion 42 is preferably 1 mm or more, and preferably 5 mm or less, more preferably 3 mm or less. The low

basis weight portions

42X and 42Y may have the same or different width L1.
The size of the high basis weight portion 41 in a plan view as shown in FIG. 14A differs depending on the type and use of the absorbent article, but in a sanitary napkin such as the napkin 1B, the length L2 in the longitudinal direction X (See FIG. 14A) is preferably 5 mm or more, more preferably 10 mm or more, and preferably 50 mm or less, more preferably 30 mm or less, and length L3 in the width direction Y (see FIG. 14A). ) Is preferably 3 mm or more, more preferably 5 mm or more, and preferably 30 mm or less, more preferably 20 mm or less.
The number of high basis weight portions 41 is preferably 5 or more, more preferably 10 or more, and preferably 70 or less, more preferably 60 or less per 50 cm ² area.

The width L5 (see FIG. 14B) of the groove 7 (7X, 7Y1, 7Y2) is preferably 0.5 mm or more, more preferably 1.0 mm or more, and preferably 5.0 mm or less, more preferably 4 0.0 mm or less.
The depth L6 of the groove 7 (see FIG. 16) is preferably 0.5 mm or more, and more preferably 1.0 mm. The depth L6 means the depth of the deep groove portion 74, which is the deepest part in the groove 7. The depth of the shallow groove portion 73 is preferably less than 0.5 mm, more preferably less than 1.1.0 mm.

The shallow groove portion 73 preferably has a shorter length in the longitudinal direction X of the napkin 1B than the high basis weight portion 41. Taking the vertical groove 7X extending in the longitudinal direction X as an example, the length L8 of the shallow groove portion 73 (see FIG. 18A) is the length L2 of the high basis weight portion 41 in the longitudinal direction X (FIG. 14A). It is preferable to be shorter than (see)). With such a configuration, the deep groove portion 74 in the vertical groove 7X is necessarily formed in the high basis weight portion 41, whereby the groove structure is stably formed and high liquid retaining performance is achieved. The ratio (L8 / L2) between the length L8 of the shallow groove portion 73 and the length L2 of the high basis weight portion 41 in the longitudinal direction X is preferably 0.06 to 0.9, more preferably 0.06 to 0.00. 2.

Moreover, in this embodiment, the site | part corresponding to the groove | channel 7 (site | part which forms the bottom wall part 71 which defines the groove | channel 7) in the non-skin contact surface 4b of the absorptive core 40B (absorber 4B) is as follows. It is preferable that the low basis weight part 42 is closer to the top sheet 2 (far from the back sheet 3) than the high basis weight part 41. That is, taking the vertical groove 7X extending in the longitudinal direction X as an example, as shown in FIG. 17, the portion corresponding to the vertical groove 7X in the low basis weight portion 42 (the bottom wall portion 71 defining the vertical groove 7X is formed. L42> L41, where L42 is the separation distance between the non-skin contact surface and the back sheet 3 and L41 is the separation distance between the non-skin contact surface and the back sheet 3 in the high basis weight portion 41. It is preferable. With such a configuration, the disadvantage that the low basis weight portion 42 is pushed and broken when the groove 7 is formed by embossing (when the absorbent core 40B is squeezed) is avoided, and the groove 7 is formed more stably. . When L42 = L41 or L42 <L41, the side wall portion 72 that defines the groove 7 in the low basis weight portion 42 and the vicinity thereof may be broken. The difference (L42−L41) between the separation distance L42 in the low basis weight portion 42 and the separation distance L41 in the high basis weight portion 41 is preferably 1.5 mm or less, more preferably 1.0 mm or less. Usually, the separation distance L41 is 0.5 mm or less.

When the formation material of each part in the napkin 1B is demonstrated, as the surface sheet 2 and the back surface sheet 3, various things conventionally used in the said technical field can be especially used without a restriction | limiting. As the surface sheet 2, for example, a liquid-permeable sheet such as a nonwoven fabric or an apertured film can be used. As the back sheet 3, for example, a resin film that does not have moisture permeability, a resin film that has micropores and has moisture permeability, a nonwoven fabric such as a water-repellent nonwoven fabric, a laminate of these and other sheets, and the like are used. Can do. Moreover, as the side sheet | seat 5, the various things conventionally used in the said technical field can be especially used without a restriction | limiting, For example, the sheet | seat made from a water-repellent nonwoven fabric or a resin film can be used, for example.

As an absorptive material which is a material for forming the absorptive core 40B, various materials conventionally used in the technical field can be used without particular limitation. For example, natural materials such as wood pulp, cotton, hemp and the like can be used as fiber materials. Fibers: synthetic fibers made of synthetic resins such as polyethylene and polypropylene; semi-synthetic fibers such as acetate and rayon can be used. Further, in addition to these fiber materials, water-absorbing polymers of various shapes such as particles can be used as the absorbent material.

The absorber (absorbent core) according to the second invention can be manufactured by the same method as the method for manufacturing the absorber (absorbent core) according to the first invention described above. The absorber 4B (absorbent core 40B) according to the second invention can be manufactured in the same manner as the absorber 4A (absorbent core 40A) according to the first invention, using the absorber manufacturing apparatus shown in FIG. The description of the method of manufacturing the absorbent body 4A (absorbent core 40A) according to the first invention described above is applicable to the method of manufacturing the absorbent body 4B (absorbent core 40B) according to the second aspect of the invention.

The present invention (second invention) is not limited to the above embodiment. For example, in the absorbent core 40B, the high basis weight portions 41 may be arranged in a staggered manner. That is, a large number of high basis weight portions 41 are arranged at predetermined intervals in the longitudinal direction X to form a high basis weight portion row, and a plurality of high basis weight portion rows are arranged at predetermined intervals in the width direction Y. In this case, the pitches of the high basis weight portions 41 in the high basis weight portion rows adjacent to each other may be shifted. In other words, the high basis weight portion 41 is adjacent to the high basis weight portion 41 when projected in a direction (width direction Y) perpendicular to the high basis weight portion row in the predetermined high basis weight portion row. You may arrange | position so that it may not correspond with the projection image of the basic weight part 41. FIG. Temporarily, the groove | channel 7 (transverse groove 7Y1 and 7Y2) extended in the width direction Y curvedly convexly toward the outward of the longitudinal direction X of the napkin 1B in planar view like the said embodiment (refer FIG. 14). (For example, even if the lateral grooves 7Y1 and 7Y2 are formed in a straight line extending in the width direction Y), the lateral grooves 7Y1 and 7Y2 and the low basis weight portion 42 are completely formed. Matching can be prevented.

Further, as described above, the groove 7 is sandwiched between the two high

basis weight portions

41, 41 and the two high

basis weight portions

41, 41 arranged in the longitudinal direction X or the width direction Y of the napkin 1B. As a method of forming continuously with the individual low basis weight portions 42, in other words, as a method of not completely matching the groove 7 and the low basis weight portion 42 of the absorbent core 40B, as in the above embodiment, In addition to the method of forming the groove 7 so as to include a convexly curved shape toward the outside of the napkin 1B in plan view and forming the low basis weight portion 42 in a straight line in plan view, a) relative A method of arranging a relatively small sized low basis weight portion 42 around a large sized high basis weight portion 41, and b) a plan view shape as a high basis weight portion 41 combined with the low basis weight portion 42. One that uses one or more of the five or more polygonal high basis weight portions 41 alone or in combination of two or more. C) The angle formed by the direction in which the grooves 7 are formed (the direction in which the linear grooves 7 extend) and the direction in which the low basis weights are formed (the direction in which the linear low basis weights extend) is set to 30 to 60 °. Method, etc.

In addition, a sanitary napkin is given as one example of application of the absorbent article of the present invention (second invention), but the present invention can also be applied to disposable diapers, incontinence pads, panty liners, and the like.

Hereinafter, the absorbent article of the present invention (third invention) will be described with reference to the drawings based on a sanitary napkin which is a preferred embodiment thereof. As shown in FIGS. 19 and 20, the napkin 1 C of the present embodiment includes a top sheet 2 disposed on the skin contact surface side, a back sheet 3 disposed on the non-skin contact surface side, and both sheets 2. It has an absorber 4C interposed between the three, and is vertically long (a shape that is long in one direction). As shown in FIG. 19, the napkin 1 C is disposed on the abdomen side of the wearer with respect to the excretion part facing part 11 disposed opposite to the excretion part (vaginal opening) of the wearer at the time of wearing, and to the excretion part facing part 11 at the time of wearing. The front portion 12 and the rear portion 13 disposed on the back side of the wearer rather than the excretory portion facing portion 11 at the time of wearing are provided in the longitudinal direction X. The excretory part opposing part 11 is a part which has a pair of

wing parts

6 and 6 on either side mentioned later. The pair of

wing parts

6 and 6 are parts that are wound around the crotch part (crotch part) of the underwear when the napkin 1C is fixed to the underwear such as shorts. In addition, when the absorbent article (sanitary napkin) of the present invention does not have a wing part, the excretion part facing part of the sanitary napkin is a so-called short-time napkin whose total length in the product longitudinal direction is 25 cm or less. Is a central portion (second region from the front) when the napkin is divided into three equal parts in the longitudinal direction to form a front portion, a central portion, and a rear portion, and the total length in the product longitudinal direction exceeds 25 cm. In the case of night and night napkins, this is the second area from the front (the third area from the back) when these napkins are equally divided into four in the longitudinal direction.

As shown in FIG. 20, the surface sheet 2 covers the entire skin contact surface 4a of the absorbent body 4C, and further extends outward in the width direction Y from the left and right side edges along the longitudinal direction X of the absorbent body 4C. Further, the back sheet 3 covers the entire area of the non-skin contact surface 4b of the absorbent body 4C, and further extends outward in the width direction Y from both side edges of the absorbent body 4C. The top sheet 2 and the back sheet 3 also extend outward in the longitudinal direction X from the front end and the rear end of the absorbent body 4C in the longitudinal direction X, respectively. They are joined together by a known joining means such as an ultrasonic seal.

As shown in FIGS. 19 and 20, a pair of

side sheets

5, 5 are disposed over the entire length of the napkin 1 C in the longitudinal direction X on both left and right side portions along the longitudinal direction X of the napkin 1 C. As for the side sheet 5, the side part of the inner side of the width direction Y is joined to the skin contact surface 2a of the surface sheet 2 by a well-known joining means, and the side part of the outer side is the absorber 4C. It extends outward in the width direction Y from the side edge along the longitudinal direction X, and the extension part is joined to the extension part from the side edge of the absorber 4C in the back sheet 3 by a known joining means. Yes. The back sheet 3 and the side sheet 5 have a maximum length of outward extension in the width direction Y from the side edge of the absorber 4C in the excretory part facing part 11, and the maximum extension part A pair of

wing portions

6 and 6 are formed.

The non-skin contact surface of the napkin 1C (the non-skin contact surface 3b of the back sheet 3) is directed to the clothing side, such as the crotch portion of the shorts when worn. The non-skin contact surface 3b is provided with an adhesive portion (not shown) for fixing the napkin 1C to an underwear crotch portion such as shorts. Further, the non-skin contact surfaces (non-skin contact surface 3b of the back sheet 3) of the pair of

wing portions

6 and 6 are adhesive portions (not shown) for fixing to the outer surface (non-skin contact surface) of the shorts. Z). These adhesive portions are provided by applying a hot melt adhesive at a predetermined location, and are covered with a release sheet (not shown) made of a film, nonwoven fabric, paper, or the like before the napkin 1C is used.

The absorbent body 4C is configured to include an absorbent core 40C including an absorbent material (fiber material such as pulp, water-absorbing polymer, etc.). The absorbent body 4C in the present embodiment is configured by covering the absorbent core 40C with a core wrap sheet (not shown) made of tissue paper or a water-permeable nonwoven fabric. The absorbent core 40C may be composed of only a fiber material such as pulp together with the high basis weight portion 41 and the low basis weight portion 42, which will be described later, or includes the fiber material and a water-absorbing polymer. In the latter case, the water-absorbing polymer may be uniformly mixed between the fiber materials, or may include a fiber layer mainly composed of the fiber material and a polymer layer mainly composed of the water-absorbing polymer, and The polymer layer may be sandwiched between the two fiber layers. The top sheet 2 and the absorber 4C, and the absorber 4C and the back sheet 3 are joined to each other by a pattern-coated adhesive (hot melt adhesive or the like) such as dots, spirals, and stripes. Also good.

As shown in FIGS. 20 and 21, the absorbent core 40 C includes a high basis weight portion 41 having a relatively large amount of absorbent material and a low basis weight portion 42 (42 X, 42 Y) having a relatively small amount of absorbent material. The high basis weight portions 41 and the low basis weight portions 42 are alternately formed in a predetermined direction (each in the longitudinal direction X and the width direction Y). More specifically, the absorbent core 40C includes a linear low basis weight portion 42X extending along the longitudinal direction X and a linear low basis weight portion extending along the width direction Y, as shown in FIG. 42Y and a plurality of low basis weight portions 42 are formed in a lattice shape as a whole, and a portion partitioned by these linear low

basis weight portions

42X and 42Y is a high basis weight portion 41. . Each of the plurality of linear low basis weight portions 42X is formed to extend over the entire length in the longitudinal direction X of the absorbent core 40C, and each of the plurality of linear low basis weight portions 42Y is absorbent. The core 40C is formed to extend over the entire length in the width direction Y. Each of the plurality of high basis weight portions 41 has a rectangular shape in plan view as shown in FIG.

In the present embodiment, as shown in FIG. 20, the absorbent core 40C has a uniform apparent thickness, so that the high basis weight portion 41 is compared to the low basis weight portion 42 (42X, 42Y). Therefore, the absorbent core 40C has a concavo-convex structure in which the high basis weight portion 41 is raised as compared with the low basis weight portion 42. When the absorbent core 40C has a concavo-convex structure, the absorbent core 40C absorbs when the napkin 1C is attached, as compared to the case where the skin contact surface and the non-skin contact surface are both substantially flat. The deformation of the conductive core 40C (absorber 4C) is easily induced.

In the cross-sectional view of the absorbent core 40C as shown in FIG. 20, the low basis weight parts 42 (42X, 42Y) are unevenly distributed in the thickness direction of the absorbent core 40C. More specifically, as shown in FIG. 20, the low basis weight portion 42 is unevenly distributed on the skin contact surface 4a side in the thickness direction T of the absorbent core 40C. And since the low basic weight part 42 is unevenly distributed in the skin contact surface 4a side in the thickness direction T in this way, the high basic weight part 41 is the opposite side to the skin contact surface 4a, ie, thickness direction. In T, it protrudes to the non-skin contact surface 4b side. Accordingly, in the absorbent core 40C, the skin contact surface 4a (opposite surface to the topsheet 2) is substantially flat with no irregularities except for a portion where a groove 7 to be described later is formed. The skin contact surface 4b (opposite surface to the back sheet 3) has a high basis weight portion 41 (convex portion) formed so as to protrude and a low basis weight portion 42 (non-convex portion) located between the high

basis weight portions

41, 41. Or it has an unevenness due to the recess).

The absorbent core 40C according to the present embodiment (the concavo-convex structure) has a plurality of absorbent parts having a rectangular shape in plan view made of an absorbent material on one surface side of the absorbent material formed into a thin plate shape. It may appear to be similar to the absorbent body described in Patent Documents 2 and 3 (absorbent body in which a plurality of absorbent parts are fixed to a sheet) in that it is configured to be spaced apart. However, as will be described later, the absorbent core 40C according to the present embodiment is manufactured by molding an absorbent material so as to have the uneven structure, and includes a high basis weight portion 41 and a low basis weight portion. 42 is integrated without using a bonding means such as an adhesive or heat-sealing, and is formed so as not to have a boundary (boundary between the high basis weight portion 41 and the low basis weight portion 42) by the same material. On the other hand, the absorbers described in

Patent Documents

2 and 3 are manufactured by fixing a plurality of the absorbing parts to the sheet separate from the absorbing parts, and the absorbing parts And the sheet are joined to each other through a joining means and have a boundary between the absorbing portion and the sheet, and the two are different in this respect. And by the difference of such a structure, while the high basic weight part 41 and the low basic weight part 42 which concern on this embodiment have the continuity in which a liquid can move smoothly, patent document 2 And the absorbent portion and the sheet in the absorbent body according to 3, since there is an interface composed of joining means between them (boundary), liquid diffusion easily occurs at the boundary portion, and the liquid can move smoothly. It is hard to say that it has continuity.

In the napkin 1C, as shown in FIG. 19 to FIG. 21, at least a pair of grooves 7 in which the topsheet 2 and the absorbent core 40C are integrally recessed are formed at predetermined intervals in a predetermined direction. The groove 7 is a space (a portion where the material for forming the napkin 1C does not exist) defined by a bottom wall portion 71 and a side wall portion 72 described later. As shown in FIG. 21A, the groove 7 includes a pair of

vertical grooves

longitudinal grooves

7X, 7X are formed on both left and right side portions along the longitudinal direction X of the absorbent core 40C with a gap in the width direction Y, and each longitudinal groove 7X is the longitudinal length of the excretory part facing part 11 It extends over the entire length in the direction X, and further extends to the front part 12 and the rear part 13 respectively. The lateral groove 7Y1 is formed in the front part 12, and the lateral groove 7Y2 is formed in the rear part 13, respectively. Both lateral grooves 7Y1 and 7Y2 are formed to include a horizontally long shape that is convexly convex outward in the longitudinal direction X in plan view, and the tops of the protrusions of both lateral grooves 7Y1 and 7Y2 have a width of Located in the center of the direction Y.

As shown in FIG. 21, the groove 7 (7X, 7Y1, 7Y2) has a shallow groove portion 73 that is recessed relatively shallow and a deep groove portion 74 that is recessed relatively deeply. The groove 7 forms a continuous line as a whole by the shallow groove portion 73 and the deep groove portion 74 being alternately connected along the length direction of the groove 7. The groove 7 is formed by squeezing the absorbent core 40C together with the top sheet 2 by embossing, and the shallow groove 73 is squeezed relatively weakly in the embossing, and the bottom depth (skin of the bottom wall 71) The depth from the contact surface 2a is a shallow portion, and the deep groove portion 74 is a portion that is relatively strongly squeezed in the embossing and has a deep bottom portion. The plan view shapes of the shallow groove portion 73 and the deep groove portion 74 are not particularly limited, and may be a rectangle, a square, a rhombus, a circle, a cross, or the like.

The groove 7 (7X, 7Y1, 7Y2) can be formed in accordance with an ordinary method by embossing such as embossing with or without heat, or ultrasonic embossing. That is, in the manufacturing process of the napkin 1C, after supplying the topsheet 2 on one surface of the absorber 4C (absorbent core 40C having an uneven structure), a predetermined portion is moved from the topsheet 2 side to the absorber 4C side by embossing. The groove 7 can be formed in the predetermined portion by pressing (squeezing) in a concave shape. In the groove 7, the top sheet 2 and the absorbent body 4C are integrated by heat fusion or the like.

The groove 7 includes at least two high basis weight portions (convex portions) 41 and 41 arranged in a predetermined direction and one low basis weight portion (non-covered portion) sandwiched between the two high

basis weight portions

41 and 41. (Convex portion or concave portion) 42. That is, the groove 7 is formed so as to straddle the unevenness of the absorbent core 40C. In the present embodiment, as shown in FIG. 21 (a), with respect to the longitudinal direction X, a pair of longitudinal grooves 7X, which are a part of the grooves 7, in the excretory part facing part 11 that is a part that directly receives excretion fluid. Each of 7X is formed continuously with two high

basis weight portions

41, 41 adjacent to each other in the longitudinal direction X and one low basis weight portion 42Y positioned therebetween, and absorbs continuously with the longitudinal direction X. It is formed so as to straddle the irregularities of the core 40C. Regarding the width direction Y, in the front portion 12, the lateral groove 7Y1, which is a part of the groove 7, is adjacent to the two high

basis weight portions

Such a positional relationship between the groove 7 and the high basis weight portion 41 and the low basis weight portion 42 is important in order to more surely exhibit the absorption / diffusion action of excretory fluid according to the present invention described later, In particular, as described above, the fact that the groove 7 (vertical groove 7X) is formed so as to straddle the irregularities of the absorbent core 40C continuous in the longitudinal direction X is due to the movement of the excretory fluid in the width direction Y to the outside. This is important because it is related to the effect of preventing the leakage (so-called side leakage). Therefore, in the present embodiment, as a device for ensuring that the arrangement over the unevenness of the groove 7 is obtained more reliably, in the longitudinal direction X of the napkin 1C, the low basis weight portion 42 is as described above. The groove 7 is formed so as to include a linear portion 42X extending in the longitudinal direction X in plan view, and the groove 7 includes a portion 7X having a curved portion and extending in the longitudinal direction X in plan view. Forming. That is, in the present embodiment, the pair of

longitudinal grooves

7X and 7X, which are a part of the groove 7, are respectively in the longitudinal direction of the napkin 1C in the excretory part facing part 11 as shown in FIG. Each of both side portions along X includes a vertically long shape that is convexly curved outward in the width direction Y of the napkin 1C. As described above, the low basis weight portion 42X of the absorbent core 40C is formed in a straight line that completely coincides with the longitudinal direction X, while the longitudinal groove 7X does not completely coincide with the longitudinal direction X (partial). The curved portion of at least the longitudinal groove 7X can completely coincide with the linear low basis weight portion 42X extending in the longitudinal direction X in plan view. However, the longitudinal grooves 7X are easily formed so as to straddle the irregularities of the absorbent core 40C continuous in the longitudinal direction X.

Further, in the present embodiment, from the same viewpoint as described above, the low basis weight portion 42 is formed so as to include the linear portion 42Y extending in the width direction Y in plan view as described above, and the groove 7 is formed so as to include portions 7Y1 and 7Y2 having a curved portion in a plan view and extending in the width direction Y. That is, in the present embodiment, the lateral grooves 7Y1 and 7Y2 that are part of the groove 7 are respectively formed in the napkin 1C at the front part 12 or the rear part 13 of the napkin 1C as shown in FIG. Of the horizontal grooves 7Y1 and 7Y2 so that at least the respective curved portions of the lateral grooves 7Y1 and 7Y2 are linear low-tsubo extending in the width direction Y in plan view. The lateral grooves 7Y1 and 7Y2 do not completely coincide with the amount portion 42Y, and the lateral grooves 7Y1 and 7Y2 are easily formed so as to straddle the unevenness of the absorbent core 40C continuous in the width direction Y.

22 to 24 schematically show the cross section of the groove 7 in each part of the absorbent core 40C. The groove 7 (7X, 7Y1, 7Y2) is defined by a bottom wall portion 71 and a side wall portion 72 standing from the bottom wall portion 71, as shown in FIGS. 22 to 24, for the sake of easy explanation, the illustration of the shallow groove portion 73 and the deep groove portion 74 is omitted, and the bottom wall portion 71 is described as a substantially flat portion having no step in the length direction of the groove 7. In practice, however, the position of the bottom wall portion in the thickness direction of the absorbent core differs between the shallow groove portion 73 and the deep groove portion 74, and the bottom wall portion 71 of the shallow groove portion 73 is relatively distant from the topsheet 2. Nearly, the bottom wall portion 71 of the deep groove portion 74 is relatively far from the surface sheet 2, so that the actual bottom wall portion 71 has a shallow groove portion 73 at a relatively high position and a deep groove portion at a relatively low position. There is a step corresponding to 74

As one of the main features of this invention, as shown in FIG.21, FIG.22 and FIG.24, the low basic weight part 42 is made into the thickness direction in the site | part which comprises the side wall part 72 in the low basic weight part 42 (42Y). The point which the tear 78 which penetrates is formed is mentioned. FIG. 25 schematically shows a substantially elliptical tear 78 and its vicinity in an enlarged view in plan view. When the groove 7 (longitudinal groove 7X) is formed by embossing (when the absorbent core 40C is squeezed), the tear 78 is concave from the skin contact surface 4a side toward the non-skin contact surface 4b. It is formed as a result of the low basis weight portion 42 being stretched along its deformed shape and being broken when it is deformed by being pushed into the space, and is a space where the material for forming the absorbent core 40C does not exist. Because the rift 78 is space, the excretory fluid cannot move along the rift 78. Such behavior of the excretory fluid at the tear 78 is particularly likely to occur when the excreted fluid is a relatively viscous fluid such as menstrual blood. Therefore, it can be said that the present invention is particularly effective when applied to absorbent articles mainly intended for absorption of menstrual blood, such as sanitary napkins and panty liners. As described above, the tear 78 has a function of hindering the movement of the excretory fluid, and such a function of the tear 78 contributes to the diffusion of the excretory fluid in the front-rear direction of the napkin 1C.

As described above, the tear 78 is formed in a portion constituting the side wall portion 72 in the low basis weight portion 42 due to the formation of the groove 7 by embossing, but the side wall portion 72 in the high basis weight portion 41 is formed. It is not formed on the constituent parts. The reason is that the high basis weight portion 41 has a thickness larger than that of the low basis weight portion 42 and is raised as a convex portion, so that when the groove 7 is embossed when the groove 7 is formed, it is pushed in a concave shape in the thickness direction. In addition, it is presumed that it is easy to be compressed in the thickness direction in accordance with the pressing and is not easily stretched in the direction intersecting the thickness direction as in the low basis weight portion 42.

Moreover, regarding the formation site of the tear 78, even in the side wall portion 72 in the same low basis weight portion 42, there are a site where the tear 78 is easily formed and a site where it is difficult to form. That is, the region sandwiched between the pair of grooves 7 and 7 (the pair of

vertical grooves

7X and 7X), in other words, the side wall portion 72 located on the inner side of the napkin with respect to the vertical groove 7X (bottom wall portion 71), The side wall 72 located on the opposite side (napkin outer side) via the longitudinal groove 7X is a portion where the tear 78 is difficult to be formed. In the present embodiment, the tear 78 is formed in the side wall 72 located on the inner side of the napkin with respect to the groove 7 (bottom wall 71), and is formed in the side wall 72 located on the outer side of the napkin. Not. At the time of forming the groove 7 by embossing, the region sandwiched between the pair of

vertical grooves

7X, 7X is embossed from the upper side (surface sheet 2 side) at both ends in the width direction Y of the region. There is no escape space for the stress of the absorber distortion due to the force to be pushed in, and therefore the tear 78 is likely to be formed. On the outer side in the width direction Y from the longitudinal groove 7X, the stress escape field of the absorber strain is in the width direction. Since it is outside Y, it is assumed that a tear 78 is difficult to form. Therefore, it can be said that the existence of the pair of grooves 7 and 7 (

vertical grooves

7X and 7X) formed at a predetermined interval is important for the formation of the tear 78.

From the viewpoint of making the most of the diffusing action of excretory liquid in the front-rear direction of the napkin 1C, which will be described later, the tear 78 is at least inward in the width direction Y from the groove 7 (vertical groove 7X) in the excretory part facing part 11. It is preferable to be formed in the side wall part 72 located in the side. In the present embodiment, the tear 78 is formed not only in the excretory part facing part 11 but also in the front part 12 and the rear part 13, and only in the side wall part (side wall part on the inner side of the napkin) 72 of the vertical groove 7X. In addition, it is also formed on the side wall portion (side wall portion on the inner side of the napkin) 72 of each of the lateral grooves 7Y1 and 7Y2. The lateral grooves 7Y1 and 7Y2 correspond to “a pair of grooves formed at predetermined intervals” that play an important role in forming the tear 78.

From the viewpoint of reliably forming the tear 78 in the portion constituting the side wall portion 72 in the low basis weight portion 42, as shown in FIG. 25, at least a portion of the deep groove portion 74 and the low basis weight portion 42 in plan view. It is preferable that they overlap. As described above, the deep groove portion 74 is a portion that is strongly squeezed compared to the shallow groove portion 73 in embossing for forming the groove 7, and the deep groove portion 74 that is such a strong squeezed portion is a plan view. In this case, the breakage of the low basis weight portion 42 due to the embossing described above is promoted, and a tear 78 is formed in the portion constituting the side wall portion 72 in the low basis weight portion 42. Is easily formed.

From the same viewpoint, as shown in FIG. 25, the deep groove portion 74 is located at the center of the width direction of the groove 7 (vertical groove 7X) (direction perpendicular to the length direction of the groove 7), and the deep groove portion It is preferable that the shallow groove portion 73 is located outside the 74 in the width direction. When the length in the width direction of the shallow groove portion 73 is L9 and the length in the width direction of the deep groove portion 74 is L10, the ratio (L9 / L10) between them is preferably 0.05 to 0.5, more preferably 0.1 to 0.4.

In the present embodiment, the high basis weight portion 41, the low basis weight portion 42, the groove 7, and the vicinity thereof, the high basis weight portion 41 has a higher density than the low basis weight portion 42, and the groove 7 is further formed. There is a density gradient. That is, in FIGS. 21B and 22 to 24, the density of the parts indicated by reference signs A to E is A ≦ B << C << E, more preferably A << B << C <D <E. The density decreases as the distance from the groove 7 (vertical groove 7X) decreases (site A), and the density increases as the distance from the groove 7 increases (area B and / or C). In the groove 7 (bottom wall portion 71), The density is maximized (sites D and E). Moreover, about the groove | channel 7 (bottom wall part 71), the site | part D in the low basic weight part 42 (42Y) is along the groove | channel 7 because the density is made a little low compared with the site | part E in the high basic weight part 41. It is more preferable that the density of the liquid is higher than that of the part C in the vicinity of the groove 7 in the high basis weight portion 41. The density gradient that the density increases as it approaches the groove 7 is mainly caused by the formation of the groove 7 by embossing as described above (squeezing of the absorbent core 40C), and an absorbent body in which a conventional leak-proof groove is formed. Also exists. In this embodiment, the density gradient is characterized in that the part C has a higher density (B << C) than the part B, and the vicinity of the groove 7 is the density of the high basis weight portion 41 and the low basis weight portion 42. Is different. The “near the groove” means the side wall portion 72 (see FIGS. 22 to 24) that defines the groove 7 and its adjacent portion (a portion adjacent to the side wall portion 72 in a plan view of the groove 7). The adjacent portion means a portion within 5 mm outward from the groove 7 (outer surface of the side wall portion 72) in a direction orthogonal to the length direction of the groove 7 (width direction of the groove 7). Usually, the boundary between the side wall portion and the adjacent portion is not clear, but in the present invention, a flat acrylic plate (weight 5 g) is provided on the skin contact surface side (surface sheet side) of the absorbent article. When the groove below the acrylic plate is visually observed in this state, the region that approaches the groove from the vicinity of the groove (the adjacent portion) in the width direction of the groove A portion where the skin contact surface (surface sheet) is separated from the acrylic plate is defined as the boundary.

As described above, the portions B and C in the vicinity of the groove 7 (vertical groove 7X) have the same distance from the groove 7, but the portion C located in the high basis weight portion 41 has a lower basis weight. The reason why the density is higher than the portion B located in the amount portion 42 (42Y) is that the high basis weight portion 41 is more absorbent than the low basis weight portion 42 before the groove 7 is formed by pressing the absorbent core 40C. This is because there are many materials and the density is high. That is, as will be described later, the absorbent core 40C according to the present embodiment obtains a deposit having an uneven structure by depositing an absorbent material so as to have a high basis weight portion 41 and a low basis weight portion 42. When the entire deposit is produced by compressing the entire deposit with a uniform compressive force using a pressure roll or the like, in such a compression process, the high basis weight portion 41 as the convex portion is more non-convex or as the concave portion. Since it is compressed more strongly than the low basis weight portion 42, the high basis weight portion 41 (site C) has a higher density than the low basis weight portion 42 (site B). Thus, there is a difference in density between the part B and the part C before the formation of the groove 7, and when the groove 7 is formed in the part B and the part C by pressing, the side wall part 72 that defines the groove 7. And this density difference is reflected in the vicinity thereof, and as a result, B << C with respect to the density. As shown in FIG. 21 (b), the tear 78 has a symmetrical relationship with the part B across the groove 7 (vertical groove 7X), so the vicinity of the tear 78 in the low basis weight portion 42 (the tear). The area within 3 mm from the peripheral edge of 78) has substantially the same density as the part B. Therefore, the vicinity of the tear 78 is also lower in density than the part C (the vicinity of the tear 78 in the low basis weight portion 42 << C).

The napkin 1C of the present embodiment has a concavo-convex structure formed by a high basis weight part (convex part) 41 and a low basis weight part (non-convex part or concave part) 42 as an absorbent core in which the grooves 7 are formed. By adopting the absorbent core 40C, it is possible to solve the above-mentioned problem ii) of the conventional absorbent article employing a combination of a flat absorbent core having no irregularities and a leak-proof groove, and the absorber 4C ( Despite the formation of the high-density grooves 7 in the absorbent core 40C), partial curing of the absorbent body 4C hardly occurs and the fit is excellent. As shown in FIG. 21, when the low basis weight portion 42 is formed on the outer side of the napkin 1 C (the outer portion of the groove 7) than the groove 7, the leakage prevention effect by the groove 7 is further increased, and the napkin A soft touch can be given to the peripheral part of 1C (especially both side edges along the longitudinal direction X of the napkin 1C). Moreover, as shown in FIG. 21, when the site | part in which the high basic weight part 41 was enclosed by the low basic weight part 42 is distribute | arranged to the substantially whole absorbent core 40C, it is with respect to a wearer at the time of mounting | wearing of the napkin 1C. The hit becomes soft and can provide a flexible feel.

Further, in the napkin 1C of the present embodiment, the groove 7 is mainly connected to two high

basis weight portions

41, 41 adjacent to each other in a predetermined direction and one low basis weight portion 42 positioned therebetween. By being formed so as to straddle the unevenness of the absorbent core 40C, excretion fluid such as menstrual blood can be quickly absorbed and diffused regardless of the amount thereof, The above-mentioned problem i) of an absorbent article employing a combination of a conventional flat absorbent core having no irregularities and a leak-proof groove can be solved, and has excellent leak-proof properties (side-leakage prevention properties), and an absorbent body. Therefore, the size of the absorbent article can be reduced, and the absorbent article can be made compact.

The absorption / diffusion action of excretory fluid in the napkin 1C of the present embodiment will be described with reference to FIG. 21 (b). The excretory fluid W such as menstrual blood excreted by the wearer of the napkin 1C is usually opposed to the excretory part. 21 is received at the center of the width direction Y of the portion 11 and moves in the width direction Y from the skin contact surface (skin contact surface 2a of the topsheet 2) toward the groove 7 (vertical groove 7X). In (b), various constituent members (surface sheet) of the napkin 1C from the part A (near the center part in the width direction Y of the excretory part facing part 11) toward the tear 78 (near the groove 7 in the low basis weight part 42). 2, move along the absorbent core 40C and the like. Thus, as described above, the tear 78 is a space in which the material for forming the absorbent core 40C such as the absorbent material (the material for forming the napkin 1C) does not exist, and therefore excretion that has reached the vicinity of the tear 78. The liquid W cannot pass through the tear 78 and therefore cannot cross the tear 78. Therefore, as shown in FIG. In the vicinity of the groove 7 (the part C on the inner side in the width direction Y from the groove 7). In addition, as described above, the vicinity of the tear 78 in the low basis weight portion 42 is similar to the portion C in the same manner as the portion B located symmetrically with the tear 78 across the groove 7 (vertical groove 7X). Since the density is low (B << C), a capillary force is likely to act between the vicinity of the tear 78 and the site C, and the movement of the excretory fluid W to the site C is also promoted by this capillary force. Is done. Thus, the excretion liquid W moves in the front-rear direction of the napkin 1C along the groove 7 in the vicinity of the groove 7 and inward in the width direction Y from the groove 7, and quickly from the excretion part facing part 11 in the longitudinal direction X. To spread.

The excretory liquid W is quickly absorbed and held by the high basis weight portion 41 while moving from the portion B to the portion C in the vicinity of the groove 7 and inward in the width direction Y from the groove 7. As shown in FIG. 24, the part exceeding the absorption capacity of the part E is located in the part E (the bottom wall part 71 defining the groove 7 in the high basis weight part 41) located outside the part C in the width direction Y. Moving. The part E is the part most compressed when the groove 7 is formed, and the density thereof is overwhelmingly higher than the part C adjacent to the width direction Y, so that the excretion fluid W moves from the part E to the part C. Therefore, it is difficult for the excretion liquid W to move outward in the width direction Y of the napkin 1C over the groove 7. The excretion fluid W that has moved to the site E via the site C passes through the groove 7 without leaking to the outside of the groove 7, and is adjacent to the site D (the bottom wall that defines the groove 7 in the low basis weight portion 42. Part 71) and further to another part E adjacent thereto. Thus, the excretory fluid W moving in the groove 7 is absorbed and held mainly by the high basis weight portion 41 during the movement.

As described above, in the napkin 1C of the present embodiment, the excreted liquid excreted in the central portion in the width direction Y of the excretory part facing part 11 is closer to the longitudinal groove 7X and the longitudinal groove 7X than the longitudinal groove 7X. In both of the portions located inward in the width direction Y, the napkin 1C is quickly diffused in the front-rear direction, and is absorbed and held mainly by the high basis weight portion 41 in the middle of such diffusion. Therefore, the napkin 1C of the present embodiment can quickly diffuse and absorb the excreted excretory liquid by the diffusion and absorption action of the excreted liquid by the cooperation of the absorbent body 4C (absorbent core 40C) and the groove 7, It is difficult to cause side leakage and can eliminate discomfort caused by the wetness of the wearer. From the viewpoint of more surely exhibiting the operational effects of the napkin 1C, it is preferable to set the dimensions and the like of the respective parts as follows.

The ratio (S41 / S42) of the basis weight S41 of the high basis weight portion 41 and the basis weight S42 of the low basis weight portion 42 of the absorbent core 40C is preferably 1.25 or more, more preferably 3 or more, and preferably Is 10 or less, more preferably 6 or less.
The basis weight S41 of the high basis weight portion 41 is preferably 100 g / m ² or more, more preferably 150 g / m ² or more, and preferably 600 g / m ² or less, more preferably 500 g / m ² or less. The basis weight S42 of the basis weight part 42 is preferably 10 g / m ² or more, more preferably 30 g / m ² or more, and preferably 150 g / m ² or less, more preferably 100 g / m ² or less.
The ratio (T41 / T42) between the thickness T41 of the high basis weight portion 41 and the thickness T42 of the low basis weight portion 42 is preferably 1 or more, more preferably 1.5 or more, and preferably 20 or less, more preferably 10 or less.
The thickness T41 of the high basis weight portion 41 is preferably 0.5 mm or more, more preferably 1 mm or more, and preferably 10 mm or less, more preferably 8 mm or less. The thickness T42 of the low basis weight portion 42 is preferably It is 0.1 mm or more, more preferably 0.2 mm or more, and preferably 5.0 mm or less, more preferably 3.0 mm or less.

The width L1 (see FIG. 21A) of the low basis weight portion 42 is preferably 0.5 mm or more, more preferably 1 mm or more, and preferably 7.5 mm or less, more preferably 5 mm or less. The low

basis weight portions

42X and 42Y may have the same or different width L1.
The size of the high basis weight portion 41 in a plan view as shown in FIG. 21A varies depending on the type and use of the absorbent article, but in a sanitary napkin such as the napkin 1C, the length L2 in the longitudinal direction X (Refer to FIG. 21A) is preferably 5 mm or more, more preferably 10 mm or more, and preferably 50 mm or less, more preferably 30 mm or less, and the length L3 in the width direction Y (see FIG. 21A). ) Is preferably 3 mm or more, more preferably 5 mm or more, and preferably 30 mm or less, more preferably 20 mm or less.
The number of high basis weight portions 41 is preferably 5 or more, more preferably 10 or more, and preferably 70 or less, more preferably 60 or less per 50 cm ² area.

The width L5 (see FIG. 21B) of the groove 7 (7X, 7Y1, 7Y2) is preferably 0.5 mm or more, more preferably 1.0 mm or more, and preferably 5.0 mm or less, more preferably 4 0.0 mm or less.
The depth L6 of the groove 7 (see FIG. 23) is preferably 0.5 mm or more, and more preferably 1.0 mm. The depth L6 means the depth of the deep groove portion 74, which is the deepest part in the groove 7. The depth of the shallow groove portion 73 is preferably less than 0.5 mm, more preferably less than 1.1.0 mm.

A length L7 (see FIG. 25) along the length direction of the groove 7 (7X, 7Y1, 7Y2) of the tear 78 is along the length direction of the low basis weight portion 42 in which the tear 78 is formed. The length is preferably 20 to 90%, more preferably 40 to 80%, with respect to the length (for example, the length along the length direction of the groove 7X of the low basis weight portion 42Y in FIG. 25).
The length L8 (see FIG. 25) along the width direction of the groove 7 (7X, 7Y1, 7Y2) of the tear 78 is preferably equal to or less than the length L7 (L7 ≧ L8).

The material for forming each part of the napkin 1C will be described. As the top sheet 2 and the back sheet 3, various materials conventionally used in the technical field can be used without particular limitation. As the surface sheet 2, for example, a liquid-permeable sheet such as a nonwoven fabric or an apertured film can be used. As the back sheet 3, for example, a resin film that does not have moisture permeability, a resin film that has micropores and has moisture permeability, a nonwoven fabric such as a water-repellent nonwoven fabric, a laminate of these and other sheets, and the like are used. Can do. Moreover, as the side sheet | seat 5, the various things conventionally used in the said technical field can be especially used without a restriction | limiting, For example, the sheet | seat made from a water-repellent nonwoven fabric and a resin film can be used.

As an absorptive material which is a forming material of the absorptive core 40C, various materials conventionally used in the technical field can be used without particular limitation. For example, natural materials such as wood pulp, cotton, hemp and the like can be used as fiber materials. Fibers: synthetic fibers made of synthetic resins such as polyethylene and polypropylene; semi-synthetic fibers such as acetate and rayon can be used. Further, in addition to these fiber materials, water-absorbing polymers of various shapes such as particles can be used as the absorbent material.

The absorber (absorbent core) according to the third invention can be manufactured by the same method as the method for manufacturing the absorber (absorbent core) according to the first invention described above. The absorber 4C (absorbent core 40C) according to the third invention can be manufactured in the same manner as the absorber 4A (absorbent core 40A) according to the first invention, using the absorber manufacturing apparatus shown in FIG. The description of the manufacturing method of the absorbent body 4A (absorbent core 40A) according to the first invention described above can be applied to the manufacturing method of the absorbent body 4C (absorbent core 40C) according to the third aspect of the invention.

The present invention (third invention) is not limited to the above embodiment. For example, in the said embodiment, although the low basic weight part 42 was unevenly distributed in the skin contact surface 4a side in the thickness direction of the absorptive core 40C, on the contrary, it is on the non-skin contact surface 4b side. It may be unevenly distributed. In that case, the high basic weight part 41 protrudes to the skin contact surface 4a side, and the upper and lower sides of the absorbent core 40C as a whole are reversed from those shown in FIG.

Moreover, the low basic weight part 42 (42X, 42Y) of planar view linear form is formed in the absorptive core 40C whole as shown in FIG. 21 (so that the front part 12, the excretion part opposing part 11, and the rear part 13 may be straddled). A region between the at least a pair of grooves 7 and 7 (

longitudinal grooves

7X and 7X) and the vicinity thereof (groove peripheral region) in the excretory part facing part 11 (of the excretion part facing part 11). It suffices if it is formed in the inner part in the width direction. Moreover, the planar view shape of the low basic weight part 42 is not restrict | limited to linear form like the said embodiment, Curve shape may be sufficient.

Further, in the absorbent core 40C, the high basis weight portions 41 may be arranged in a staggered manner. That is, a large number of high basis weight portions 41 are arranged at predetermined intervals in the longitudinal direction X to form a high basis weight portion row, and a plurality of high basis weight portion rows are arranged at predetermined intervals in the width direction Y. In this case, the pitches of the high basis weight portions 41 in the high basis weight portion rows adjacent to each other may be shifted. In other words, the high basis weight portion 41 is adjacent to the high basis weight portion 41 when projected in a direction (width direction Y) perpendicular to the high basis weight portion row in the predetermined high basis weight portion row. You may arrange | position so that it may not correspond with the projection image of the basic weight part 41. FIG. By doing in this way, the groove | channel 7 (transverse groove 7Y1 and 7Y2) extended in the width direction Y will be on the outward of the longitudinal direction X of the napkin 1C by planar view like the said embodiment (refer FIG. 21). Even if it is not formed so as to include a horizontally long shape that is convexly convex (for example, even if the lateral grooves 7Y1, 7Y2 are formed in a straight line extending in the width direction Y), the lateral grooves 7Y1, 7Y2 It can prevent that the quantity part 42 corresponds completely.

Further, as described above, the groove 7 is formed in the two high

basis weight portions

41, 41 and the two high

basis weight portions

41, 41 arranged in a predetermined direction (longitudinal direction X or width direction Y of the napkin 1C). As a method of continuously forming the sandwiched one low basis weight portion 42, in other words, as a method of not making the groove 7 and the low basis weight portion 42 of the absorbent core 40C completely coincide with each other, the above embodiment is used. In addition to the method of forming the groove 7 in a plan view so as to include a shape curved convexly toward the outside of the napkin 1C, and forming the low basis weight portion 42 in a straight line in plan view, A) a method of disposing a relatively small size low basis weight portion 42 around a relatively large size high basis weight portion 41; b) a high basis weight portion 41 combined with the low basis weight portion 42; One type of the high basis weight portion 41 having a polygonal shape with a pentagonal shape or more in plan view alone or in combination of two or more types C) The angle formed by the direction in which the grooves 7 are formed (the direction in which the linear grooves 7 extend) and the direction in which the low basis weights are formed (the direction in which the linear low basis weights extend) is 30 to 60 °. The method of setting to, etc. are mentioned.

In addition, a sanitary napkin is given as one example of application of the absorbent article of the present invention (third invention), but the present invention can also be applied to disposable diapers, incontinence pads, panty liners, and the like.

The absorbent article of the present invention (fourth invention) will be described below with reference to FIGS. 26 to 29 based on preferred embodiments thereof. Examples of the absorbent article 1D of the present embodiment (hereinafter, also referred to as “absorbent article 1D”) include sanitary napkins, disposable diapers, and incontinence pads.
The absorbent article 1D has a liquid-permeable surface sheet 2 arranged on the skin facing surface (surface directed toward the skin side of the wearer) and a non-skin facing surface (on the side opposite to the wearer's skin side). A longitudinally absorbent main body 10 having a liquid-impermeable rear surface sheet 3 disposed on the side and a longitudinally absorbent body 4D interposed between the

sheets

2 and 3. As shown in FIG. 26, the absorbent article 1 D is formed symmetrically with respect to the center line CL extending in the longitudinal direction of the absorbent main body 10. The “X” direction shown in each figure is a direction parallel to the center line CL, and is also the same direction as the longitudinal direction of the absorbent main body 10. Moreover, the “Y” direction shown in each figure is a direction orthogonal to the center line CL, and is also the same direction as the width direction of the absorbent main body 10.

As shown in FIG. 26, each of the topsheet 2 and the backsheet 3 forming the absorbent main body 10 has an elongated shape that is long in the longitudinal direction (X direction) of the absorbent main body 10, and is absorbent. It has a contour that matches the contour of the main body 10. Thus, as for the surface sheet 2 and the back surface sheet 3, in the absorbent article 1D, the surface sheet 2 and the back surface sheet 3 are formed in the same shape and size. As shown in FIGS. 26 and 27, each of the top sheet 2 and the back sheet 3 covers the entire surface of the absorbent body 4D on the skin facing surface side and the entire surface of the non-skin facing surface side, and extends from the periphery of the absorbent body 4D. It has the extended part which protrudes, These extended parts are joined by hot embossing, and the peripheral seal part 5 is formed in the peripheral part.
In the absorbent article 1D, the peripheral seal portion 5 is formed by hot embossing, but may be formed by ultrasonic sealing, or may be formed by an adhesive such as hot melt.

The absorbent body 4D includes an absorbent core 40D including an absorbent material 45 (fiber material such as pulp, water-absorbing polymer, etc.). The absorbent body 4D in the present embodiment is configured by covering the absorbent core 40D with a core wrap sheet (not shown) made of tissue paper or a water-permeable nonwoven fabric. Both the high basic weight part 41 and the low basic weight part 42 which are mentioned later may be comprised only from fiber materials, such as a pulp, and the absorptive core 40D may hold | maintain a water absorbing polymer between these fiber materials. The top sheet 2 and the absorber 4D, and the absorber 4D and the back sheet 3 are joined to each other by a pattern-coated adhesive (hot melt adhesive or the like) such as dots, spirals, and stripes. Also good.

In the present invention (fourth invention), the absorbent body 4D includes a high basis weight portion 41 having a relatively high basis weight, and a low basis weight portion 42 having a relatively low basis weight adjacent to the high basis weight portion 41. And have. Specifically, in the absorbent article 1D, as shown in FIG. 27 and FIG. 28, the absorbent core 40D constituting the absorbent body 4D includes a high basis weight portion 41 and an absorbent material having a relatively large amount of the absorbent material. Has a relatively low low basis weight portion 42 (42X, 42Y). As shown in FIG. 27, the apparent thickness of the absorbent core 40D is uniform. 27 and 28, the absorbent core 40D has a linear (continuous linear) low basis weight portion 42X extending along the longitudinal direction X and a linear (continuous) extending along the width direction Y. A plurality of straight basis) low basis weight portions 42Y are formed. As shown in FIGS. 27 and 28, the low basis weight portion 42 is composed of a linear low basis weight portion 42X extending in the longitudinal direction X and a linear low basis weight portion 42Y extending in the width direction Y as a whole. It is formed in a lattice shape, and a high basis weight portion 41 is arranged at a portion (the position of the lattice eye) partitioned by these linear low

basis weight portions

42X and 42Y. Each of the plurality of linear low basis weight portions 42X is formed to extend over the entire length in the longitudinal direction X of the absorbent core 40D, and each of the plurality of linear low basis weight portions 42Y is absorbent. The core 40D is formed to extend over the entire length in the width direction Y.

In this invention (4th invention), as shown in FIG. 27, the high basic weight part 41 and the low basic weight part 42 are integrally molded, and the high basic weight part 41 is formed in the back sheet 3 side of absorber 4D. The uneven structure formed by alternately arranging the convex portions and the concave portions that are the low basis weight portions 42 is formed, and the low basis weight portions 42 are unevenly distributed on the surface sheet 2 side of the absorbent body 4D. Here, “being integrally formed” means that the high basis weight portion 41 and the low basis weight portion 42 are integrated so as not to be separated from each other without using a bonding means such as an adhesive or heat fusion, It means that it is integrally formed from the same material. Thus, if the high basic weight part 41 and the low basic weight part 42 are integrally molded, it will have the continuity which a bodily fluid can move smoothly. As shown in FIG. 27, the low basis weight part 42 is unevenly distributed on the topsheet 2 side (skin facing surface side of the absorbent body 4D) in the thickness direction T of the absorbent article 1D. And since the low basic weight part 42 is unevenly distributed in the surface sheet 2 side of the thickness direction T in this way, as shown in FIG. 27, the high basic weight part 41 is the opposite side to the surface sheet 2 side, That is, it protrudes to the back sheet 3 side in the thickness direction T (the non-skin facing surface side of the absorber 4D). In the absorbent core 40D, the skin facing surface (surface on the surface sheet 2 side) side of the absorbent core 40D is composed of the low basis weight portion 42 and is formed substantially in a substantially flat shape. Further, in the absorbent core 40D, a plurality of high basis weight portions 41 (convex portions) and high basis weight portions 41 that are formed to protrude on the non-skin facing surface (surface on the back sheet 3 side) side of the absorbent core 40D. , 41 and a low basis weight portion 42 (concave portion) is formed between the concave and convex portions.

In the absorbent article 1D formed as described above, as shown in FIG. 27, the low basis weight portion (concave portion) 42 is recessed toward the topsheet 2, and the high basis weight portion (convex portion) 41 is the back surface. Convex on the sheet 3 side. That is, the concave portion recessed on the surface sheet 2 side in the concave-convex structure of the absorber 4D is mainly formed by the low basis weight portion 42, and the convex portion protruding toward the back sheet 3 side in the concave-convex structure of the absorber 4D is mainly formed. The high basis weight portion 41 is formed. Here, “the recess is mainly formed by the low basis weight portion 42” means that the high basis weight portion 41 near the boundary between the low basis weight portion 42 and the high basis weight portion 41 forms a part of the recess. Similarly, “the convex portion is mainly formed by the high basis weight portion 41” means that the low basis weight in the vicinity of the boundary between the high basis weight portion 41 and the low basis weight portion 42. This means that the amount portion 42 forms a part of the convex portion.

In the case where the absorbent article 1D is used for a sanitary napkin, the width L1 of the low basis weight portion 42 is easy to bend according to the shape of the wearer's body, and the smoothness of the surface is taken into consideration for the wearer. From the viewpoint of providing an excellent wearing feeling, it is preferably 0.5 mm or more, preferably 2.5 mm or less, and more preferably 1.5 mm or less.
Moreover, when the absorbent article 1D is used for a disposable diaper, the width L1 of the low basis weight portion 42 takes into account that the low density portion temporarily acquires the liquid and quickly draws the liquid from the surface. From the viewpoint that it is necessary to design slightly larger than the design value of the sanitary napkin, it is preferably 1.0 mm or more, preferably 7.0 mm or less, more preferably 5.0 mm or less.
Note that the width L1 may be the same or different between the low basis weight portion 42X in the longitudinal direction X and 42Y in the width direction Y. The width L1 is a measured value at the position of the bottom of the recess in the concavo-convex structure of the absorber 4D.

When the absorbent article 1D is used for a sanitary napkin, the basis weight of the low basis weight portion 42 (42X, 42Y) forming the recess is preferably 20 g / m ² , more preferably 50 g / m ² , And it is preferably 200 g / m ² or less, more preferably 150 g / m ² or less. Moreover, the high basic weight part 41 which forms a convex part preferably has a basis weight of 50 g / m ² , more preferably 100 g / m ² , and preferably 500 g / m ² or less, more preferably 400 g / m ^2. It is as follows. Moreover, the thickness of the low basic weight part 42 (concave part) is 80% or less of the thickness of the high basic weight part 41 (convex part), preferably 70% or less, and the thickness of the low basic weight part 42 (concave part) is preferably Is 0.3 mm or more, more preferably 0.5 mm or more, and preferably 3.0 mm or less, more preferably 2.0 mm or less. Furthermore, the thickness of the high basis weight part 41 (convex part) is preferably 0.5 mm or more, more preferably 1.0 mm or more, and preferably 7.0 mm or less, more preferably 5.0 mm or less.
In the case where the absorbent article 1D is used for a disposable diaper, the low basis weight portions 42 (42X, 42Y) that form the recesses temporarily acquire the liquid and take the function of quickly drawing the liquid from the surface. The basis weight is preferably 30 g / m ² , more preferably 50 g / m ² , and preferably 300 g from the viewpoint that the basis weight is preferably designed to be slightly larger than the design value of the sanitary napkin. / M ² or less, more preferably 200 g / m ² or less. Moreover, the high basic weight part 41 which forms a convex part preferably has a basis weight of 100 g / m ² , more preferably 150 g / m ² , and preferably 700 g / m ² or less, more preferably 500 g / m ^2. It is as follows. Moreover, the thickness of the low basic weight part 42 (concave part) is 80% or less of the thickness of the high basic weight part 41 (convex part), preferably 70% or less, and the thickness of the low basic weight part 42 (concave part) is preferably Is 0.3 mm or more, more preferably 0.5 mm or more, and preferably 5.0 mm or less, more preferably 3.0 mm or less. Furthermore, the thickness of the high basis weight part 41 (convex part) is preferably 1.0 mm or more, more preferably 1.5 mm or more, and preferably 9.0 mm or less, more preferably 7.0 mm or less.
In addition, the thickness of the high basic weight part 41 (convex part) and the low basic weight part 42 (42X, 42Y) (recessed part) is the width direction (a) shown in FIG. Y direction) or in the longitudinal direction X, and the cross section of the cut sample is measured. The thickness of the high basis weight part 41 (convex part) is a value measured at the thickest position in the convex part, and the thickness of the low basis weight part 42 (concave part) is a value measured at the thinnest position in the concave part. is there. When it is difficult to measure with the naked eye, the section of the cut sample may be observed and measured at a magnification of 25 to 50 times using, for example, a microscope (VHX-1000 manufactured by KEYENCE).
The basic weight of the high basic weight part 41 and the low basic weight part 42 is measured as follows.

<Measurement method of basis weight>
The measuring method of the basic weight of the high basic weight part 41 and the low basic weight part 42 is as follows.
From the absorbent body 4D, the boundary line portion between the high basis weight portion 41 and the low basis weight portion 42 is cut using a single blade razor manufactured by Feather Corporation. Ten small pieces of the high basis weight portion 41 obtained by cutting were measured using an electronic balance (Electronic balance GR-300 manufactured by A & D, accuracy: 4 digits after the decimal point), and averaged. Find the weight of one small piece. The basis weight of the high basis weight portion 41 is calculated by dividing the calculated weight by the area per piece of the high basis weight portion 41 calculated from the design dimensions of the high basis weight portion 41.
Next, along the boundary line extending in the product longitudinal direction of the high basis weight portion 41 and the low basis weight portion 42, the length is 100 mm, and the width is a piece manufactured by Feather Co., Ltd. according to the design dimensions of the width of the low basis weight portion 42. Using a blade razor, cut out five samples of the thin striped low basis weight portion 42. Each of the five obtained samples is measured using an electronic balance (Electronic Balance GR-300 manufactured by A & D, accuracy: 4 digits after the decimal point), and the weight of one sample of the low basis weight portion 42 is obtained on average. The calculated weight is divided by the area of the sample of the low basis weight portion 42 to calculate the basis weight of the low basis weight portion 41.

In the absorbent body 4D of the absorbent article 1D, since the high basis weight portion 41 has more absorbent material than the low basis weight portion 42, the high basis weight portion 41 includes the low basis weight portion 42 ( 42X, 42Y).
When the absorbent article 1D is used for a sanitary napkin, the ratio (D41 / D42) of the density D41 of the high basis weight portion 41 and the density D42 of the low basis weight portion 42 is 1/4 to 3/4. It is preferably 1/3 to 2/3. Further, the density of the low basis weight portion 42 that forms the concave portion is 0.03 to 0.18 g / cm ³ , and preferably 0.05 to 0.15 g / cm ³ . The high basis weight portion 41 forming the convex portion has a density of 0.05 to 0.50 g / cm ³ , and preferably 0.10 to 0.40 g / cm ³ .
When the absorbent article 1D is used for a disposable diaper, the ratio (D41 / D42) of the density D41 of the high basis weight portion 41 and the density D42 of the low basis weight portion 42 is 1/5 to 3/4. It is preferably 1/4 to 2/3. Further, the density of the low basis weight portion 42 forming the concave portion is 0.01 to 0.20 g / cm ³ , and preferably 0.03 to 0.15 g / cm ³ . The high basis weight portion 41 forming the convex portion has a density of 0.05 to 0.50 g / cm ³ , and preferably 0.10 to 0.40 g / cm ³ .
The density of the high basic weight part 41 and the low basic weight part 42 is measured as follows.

<Density measurement method>
Using a microscope VHX-1000 manufactured by KEYENCE, the cross section corresponding to FIG. 27 of the absorber 4D is observed, and the thicknesses of the high basis weight portion 41 and the low basis weight portion 42 are measured.
The density of the high basis weight part 41 and the low basis weight part 42 is calculated by dividing the basis weight of the high basis weight part 41 and the low density part 42 obtained by the above-described method by the measured thickness.

In the absorbent article 1D, as shown in FIG. 28, the high basis weight portion 41 forming the convex portion has a corner formed in an arc shape when seen in a plan view. Specifically, as shown in FIG. 28, the high basis weight portion 41 of the absorbent article 1D has a four-corner arc shape in plan view, and the curvature radius of each corner is preferably 0.5 mm or more, More preferably, it is 1.0 mm or more, preferably 5.0 mm or less, more preferably 3.0 mm or less. Thus, when the corner of the high basis weight portion 41 is formed in an arc shape, the high basis weight portion 41 stacked in the drum recess 51 formed on the rotary drum 50 is transferred onto the mesh belt 75. In this case, it is easy to be quickly transferred from the drum recess 51, and the effect of improving the moldability of the high basis weight portion 41 is achieved. In the absorbent article 1D, the high basis weight portion 41 is viewed in plan, and the corners are formed in an arc shape, but the shape may not be arc shape, and the plan view shape of the high basis weight portion 41 is A rectangular shape, an ellipse, etc. may be sufficient.

As shown in FIG. 28, when the absorbent article 1D is used for a sanitary napkin, the high basis weight portion 41 forming the convex portion preferably has a length L2 in the longitudinal direction X. Is 10 mm or more, more preferably 15 mm or more, and preferably 30 mm or less, more preferably 25 mm or less. The length L3 in the width direction Y is preferably 5 mm or more, more preferably 7.5 mm or more, and preferably 25 mm or less, more preferably 20 mm or less.
In the case where the absorbent article 1D is used in a disposable diaper, the high basis weight portion 41 forming the convex portion has a length L2 in the longitudinal direction X of preferably 10 mm or more, more preferably 20 mm or more, and preferably Is 70 mm or less, more preferably 60 mm. The length L3 in the width direction Y is preferably 5 mm or more, more preferably 10 mm or more, and preferably 50 mm or less, more preferably 40 mm or less.

In the present invention (fourth invention), as shown in FIGS. 27 and 28, the concave and convex structure (low basis weight portion) 42 and the back sheet 3 are formed in the concave and convex structure of the absorbent body 4D. The space 6 extending continuously in at least the longitudinal direction X. As described above, in the absorbent article 1D, as shown in FIGS. 27 and 28, the low basis weight portion 42 (42X, 42Y) is formed in a lattice shape as a whole, and the high basis weight is located at the position of the lattice eye. The portion 41 is disposed, and the concave portion (low basis weight portion 42) is disposed so as to surround the convex portion (high basis weight portion 41). Thus, in the absorbent article 1D, as shown in FIGS. 27 and 28, a plurality of continuous linear recesses (low basis weight portions 42X) extending in the longitudinal direction X and a plurality of back sheets 3 are formed. The space 6X extends continuously in the longitudinal direction X, and the plurality of spaces 6Y formed by the continuous linear recesses (low basis weight portion 42Y) extending in the width direction Y and the back sheet 3 have a width. Each extends continuously in the direction Y.

In the sanitary napkin, the humidity in the dressing is particularly high due to absorption of menstrual blood, and in the disposable diaper, the humidity in the dressing is considered to be particularly high due to absorption of urine.
In the sanitary napkin, in the case where the absorbent article 1D is used for a sanitary napkin, from the viewpoint of effectively reducing the humidity in the wearing at the time of use, the space 6X continuously extending in the longitudinal direction X (low 2 or more are preferable, and it is more preferable that 3 or more are provided.
In disposable diapers, the amount of urine absorbed per disposable diaper is generally larger than the amount of menstrual blood absorbed per sanitary napkin. Generally, disposable diapers are more disposable than sanitary napkins. Since the absorbent body is wide, from the viewpoint of further effectively reducing the humidity in the wearing during use, when the absorbent article 1D is used in a disposable diaper, a space continuously extending in the longitudinal direction X 6X (the same number as the low basis weight portion 42X) is preferably arranged in three or more, and more preferably four or more.
For the same reason, when the absorbent article 1D is used for a sanitary napkin, eight or more spaces 6Y (the same number as the low basis weight portion 42Y) continuously extending in the width direction Y are arranged. It is preferable that 10 or more are arranged. When the absorbent article 1D is used in a disposable diaper, it is preferable that 10 or more spaces 6Y (the same number as the low basis weight portion 42Y) extending continuously in the width direction Y are arranged, 12 More preferably, it is arranged above.

In the absorbent article 1D, the absorbent body 4D corresponds to the concave portion (low basis weight portion 42) of the concavo-convex structure on the back sheet 3 side on the top sheet 2 side of the absorbent body 4D, as shown in FIG. And it has the surface side recessed part 43 dented in the back surface sheet 3 side. Specifically, as described above, in the absorbent article 1D, the recess (low basis weight portion 42) has a plurality of continuous linear recesses (low basis weight portions) extending in the longitudinal direction X as shown in FIG. 42X) and a plurality of continuous linear recesses (low basis weight portion 42Y) extending in the width direction Y. Accordingly, in the absorbent article 1D, the absorbent body 4D corresponds to each of the plurality of continuous linear recesses (low basis weight portions 42X) extending in the longitudinal direction X, and the surface of the top sheet 2 side on the back sheet 3 side. A plurality of surface side recesses 43X (see FIGS. 28 and 29A), each surface side recess 43X extends linearly in the longitudinal direction X and extends in the width direction Y. Corresponding to each of a plurality of continuous linear recesses (low basis weight portion 42Y), the surface sheet 2 side has a plurality of surface side recesses 43Y (see FIG. 28) recessed on the back sheet 3 side, The front surface side recess 43Y extends in a continuous straight line in the width direction Y. As shown in FIG. 28, the number of the low basis weight portions 42X (space 6X) is the same as the number of the surface side recesses 43X, the number of the low basis weight portions 42Y (space 6Y), and the number of the surface side recesses 43Y. Are the same number.

As described above, the absorbent body 4D of the absorbent article 1D has the surface-side

concave portions

43X and 43Y corresponding to the concave portions (low

basis weight portions

42X and 42Y) of the concave-convex structure, as shown in FIG. However, the absorbent article 1D is easily deformed into a convex shape toward the wearer's skin to improve fit and prevent leakage, and the non-skin compared to the wearer's skin contact surface of the absorbent body 4D By increasing the area of the contact surface, the absorbed liquid is more easily evaporated from the non-skin contact surface, and from the viewpoint of preventing an increase in humidity on the skin contact surface side, The depth d2 of the

quantity parts

42X, 42Y) is deeper than the depth d1 of the surface side recesses 43X, 43Y. The depth d2 of the recesses (low

basis weight portions

42X, 42Y) is preferably at least 3 times the depth d1 of the surface side recesses 43X, 43Y, and more preferably at least 5 times the depth d1. The depth d1 of the surface side

concave portions

43X and 43Y is preferably 2 to 20% of the thickness of the convex portion (high basis weight portion 41) in the absorber 4D (absorbent core 40D), and is 3 to 15%. More preferably. The depth d2 of the recesses (low

basis weight portions

42X, 42Y) and the depth d1 of the surface side recesses 43X, 43Y are the thicknesses of the high basis weight portion 41 (convex portion) and the low basis weight portion 42 (recessed portion) described above. Measure in the same manner as above.

As shown in FIG. 29A, the absorbent body 4D (absorbent core 40D) of the absorbent article 1D is a length of the lower side L5 on the back sheet 3 side in a cross-sectional view across the width direction (Y direction). However, it is longer than the length of the upper side L4 on the surface sheet 2 side.
In particular, when the absorbent article 1D is used for a sanitary napkin, the length of the lower side L5 is the length of the upper side L4 from the viewpoint of effectively reducing the humidity generated from menstrual blood absorbed by the absorbent body 4D. The thickness is preferably 1.5 to 5 times, more preferably 2 to 4 times.
In particular, when the absorbent article 1D is used in a disposable diaper, the length of the lower side L5 is the length of the upper side L4 from the viewpoint of effectively reducing the humidity generated from the urine absorbed in the absorbent body 4D. The thickness is preferably 1.5 to 7 times, more preferably 2 to 5 times.
The length of the lower side L5 is measured in the same manner as the thicknesses of the high basis weight portion 41 (convex portion) and the low basis weight portion 42 (concave portion) described above. The lower side L5 is a contour path, and the lower side L5 is the length in the width direction (Y direction) at the top of the convex portion (high basis weight portion 41) of the concavo-convex structure on the back sheet 3 side, and the convex portion (high plow). Measure the length of the pair of walls facing each other in the Y direction forming the amount portion 41) and the length in the width direction (Y direction) at the bottom of the concave portion (low basis weight portion 42) of the concavo-convex structure, and add them Is the calculated length. For the upper side L4, the contour path length is measured in the same manner as the lower side L5.

As described above, the space 6 formed by the concave portion (low basis weight portion 42) of the uneven structure on the back sheet 3 side and the back sheet 3 is as shown in FIGS. 27 and 28 in the absorbent article 1D. It consists of a plurality of spaces 6X extending continuously in the longitudinal direction X and a plurality of spaces 6Y extending continuously in the width direction Y. In the absorbent article 1D, the low basis weight portion 42 in the intersecting region 6XY of the space 6X extending in the longitudinal direction X and the space 6Y extending in the width direction Y is the center of the intersecting region 6XY as shown in FIG. The thickness is the thinnest in the part. More specifically, the low basis weight portion 42X (concave portion) forming the space 6X continuously extending in the longitudinal direction X is formed in an arc shape at the bottom of the concave portion as shown in FIG. 29B. The low basis weight portion 42Y (concave portion) that forms the space 6Y continuously extending in the width direction Y is also formed in an arc shape at the bottom of the concave portion in a cross-sectional view. In the intersection region 6XY between the space 6Y in the width direction 6X and the space 6Y, the central portion is most concave on the surface sheet 2 side, and the central portion is thicker than the boundary between the adjacent convex portions (high basis weight portion 41). The thickness is the smallest among the low basis weight portions 42. With such a configuration, the absorbed liquid quickly penetrates the space 6X in the longitudinal direction X and the space 6Y in the width direction Y through the intersecting region 6XY, quickly absorbs the liquid from the top sheet 2, and is excellent for the wearer. An effect of providing a dry feeling can be achieved.

In particular, in the absorbent body 4D of the absorbent article 1D, as described above, the surface side concave portion 43X is formed corresponding to the low basis weight portion 42X that forms the concave portion in the longitudinal direction X, and the concave portion in the width direction Y is formed. As shown in FIG. 29 (b), the surface-side recess 43X has a circular arc shape at the bottom of the surface-side recess 43X. The surface side recess 43Y is also formed in an arc shape at the bottom of the recess as viewed in cross section. Therefore, in the intersecting region between the front-side concave portion 43X in the longitudinal direction X and the front-side concave portion 43Y in the width direction Y, the central portion is most concave on the back sheet 3 side. Therefore, the distance between the central portion in the intersecting region between the surface-side concave portion 43X and the surface-side concave portion 43Y and the central portion in the intersecting region 6XY between the space 6X in the longitudinal direction X and the space 6Y in the width direction Y is the largest. It is short and the thickness of the central part in the intersection area 6XY is the thinnest in the low basis weight part 42. With such a configuration, the moisture existing between the absorbent article 1D and the wearer's skin can be absorbed through the intersecting region 6XY, and the effect of making the wearer less likely to feel stuffiness can be achieved.

The absorber (absorbent core) according to the fourth invention can be manufactured by the same method as the method for manufacturing the absorber (absorbent core) according to the first invention described above. The absorber 4D (absorbent core 40D) according to the fourth invention can be manufactured in the same manner as the absorber 4A (absorbent core 40A) according to the first invention using the absorber manufacturing apparatus shown in FIG. The description of the manufacturing method of the absorbent body 4A (absorbent core 40A) according to the first invention described above can be applied to the manufacturing method of the absorbent body 4D (absorbent core 40D) according to the third aspect of the invention.

The forming material in the absorbent article 1D will be described.
As the top sheet 2, various types conventionally used in the technical field can be used without particular limitation. As the surface sheet 2, for example, a liquid-permeable sheet such as a nonwoven fabric or an apertured film can be used.
As the absorbent material 45 which is a material for forming the absorbent core 40D, various materials conventionally used in the technical field can be used without particular limitation. For example, as a fiber material, wood pulp, cotton, hemp, etc. Natural fibers; synthetic fibers made of synthetic resins such as polyethylene and polypropylene; semi-synthetic fibers such as acetate and rayon can be used. Further, in addition to these fiber materials, water-absorbing polymers of various shapes such as particles can be used as the absorbent material.

As the back sheet 3, a moisture permeable sheet having moisture permeability is used. Examples of moisture permeable sheets include sheets having a large number of fine pores and high water vapor permeability, such as inorganic powders such as calcium carbonate and barium sulfate, and incompatible organic polymers such as nylon and polystyrene. A sheet having fine pores and having a high water vapor permeability, which is obtained by uniaxially or biaxially stretching a polyethylene film kneaded with bismuth, is preferably used. Specifically, a basis weight obtained by stretching a polyethylene film having a basis weight of 20 to 50 g / m ² containing 30 to 60% by weight of calcium carbonate or the like having an average particle size of 0.5 to 1.0 μm twice in the MD direction. Examples thereof include a moisture permeable film of 13 to 28 g / m ² . As the moisture permeable sheet, a water repellent nonwoven fabric or a composite sheet of the above sheet and the water repellent nonwoven fabric may be used.

In the case where the absorbent article 1D is used for a sanitary napkin, the absorbent article 1D has a sufficient ventilation rate to quickly exhaust moisture existing between the wearer's skin and the sanitary napkin surface, and is fine enough to allow air to pass through. The moisture permeability of the moisture permeable sheet used for the back sheet 3 is preferably 0.5 g / 100 cm ² · hr or more, from the viewpoint that it is necessary to have sufficient water pressure resistance so that menstrual blood does not ooze out from the pores. Preferably it is 1.0 g / 100 cm ² · hr or more, preferably 3.0 g / 100 cm ² · hr or less, more preferably 2.0 g / 100 cm ² · hr or less, and more specifically, preferably 0 g / 100 cm ² · hr or less. 0.5 to 3.0 g / 100 cm ² · hr, more preferably 1.0 to 2.0 g / 100 cm ² · hr.
When the absorbent article 1D is used for a disposable diaper, it is necessary to quickly evaporate a large amount of moisture generated from urine from the inside of the disposable diaper. For this reason, the moisture permeability of the moisture permeable sheet used for the back sheet 3 is preferably 0.7 g / 100 cm ² from the viewpoint that sufficient water pressure resistance is easily expressed even if many fine holes are present in the back sheet 3. Hr or more, more preferably 1.2 g / 100 cm ² · hr or more, and preferably 4.0 g / 100 cm ² · hr or less, more preferably 3.0 g / 100 cm ² · hr or less, more specifically Is preferably 1.2 to 3.0 g / 100 cm ² · hr, more preferably 0.7 to 4.0 g / 100 cm ² · hr.

The effect at the time of using the absorbent article 1D of embodiment of this invention (4th invention) mentioned above is demonstrated.
As shown in FIG. 27, the absorbent body 4D included in the absorbent article 1D includes an integrally formed high basis weight portion 41 (convex portion) and low basis weight portion 42 (low

basis weight portions

42X, 42Y) (concave portion). The low basis weight portion 42 (low

basis weight portions

42X and 42Y) is unevenly distributed on the top sheet 2 side, and has an uneven structure on the back sheet 3 side of the absorbent body 4D. Thus, since the high basic weight part 41 and the low basic weight part 42 (low

basic weight part

42X, 42Y) are integrally molded, the low basic weight unevenly distributed in the surface sheet 2 side at the time of use of absorbent article 1D. The body fluid easily moves from the portion 42 (low

basis weight portions

42X, 42Y) to the high basis weight portion 41, and the absorbent body 4D of the absorbent article 1D has the high basis weight portion 41 and the low basis weight portion 42 (low basis weight).

Part

42X, 42Y), the lower side L5 of the back sheet 3 side is longer than the upper side L4 of the top sheet 2 side, that is, the back sheet 3 of the absorber 4D. The surface area of the surface on the side is larger than the surface area of the surface on the surface sheet 2 side, and the vapor divergence amount on the back sheet 3 side is likely to increase. In addition, a space 6X formed by the concave portion (low basis weight portion 42 (low basis weight portion 42X)) and the moisture-permeable back sheet 3 in the uneven structure on the back sheet 3 side of the absorber 4D is continuous in the longitudinal direction X. Therefore, moisture in the wearing during use is easily diffused with the space 6X as a passage. Therefore, according to the absorbent article 1D, it is possible to effectively reduce the humidity in the wearing during use, reduce the wet feeling, and give a comfortable wearing feeling.

In particular, in the absorbent article 1D, the high basis weight portion 41 (convex) is formed at a higher density than the low basis weight portion 42 (42X, 42Y) (concave), and therefore the absorbent article 1D is used. Sometimes, the body fluid is more likely to move from the low basis weight portion 42 (low

basis weight portions

42X, 42Y) unevenly distributed on the surface sheet 2 side to the high basis weight portion 41. The high basis weight portion 41 has a relatively high absorption capacity with respect to the low basis weight portion 42 and has a high density, and therefore absorbs liquid faster than the low basis weight 42. For this reason, since the low basic weight part 42 is more difficult to absorb liquid than the high basic weight part 41, the low basic weight part 42 is less likely to swell and is adjacent to the enemy basic weight part even after the absorber 4D absorbs a relatively large amount of liquid. The

spaces

6X and 6Y are not lost. In particular, in the absorbent article 1D, the space 6Y formed by the concave portion (low basis weight portion 42 (low basis weight portion 42Y)) and the moisture-permeable back sheet 3 also extends continuously in the width direction Y. Therefore, the moisture in the wearing during use is more easily diffused from both side edges of the product, with the space 6Y having a shorter moving passage as a passage.

Moreover, as shown to Fig.29 (a), the absorber 4D with which the absorbent article 1D is equipped has surface side recessed

part

43X, 43Y corresponding to the recessed part (low

basic weight part

42X, 42Y) (recessed part) of an uneven structure. Since it has, it is easy to bend | bend in any direction of the skin contact surface side and the non-skin contact surface side, and it is easy to deform | transform more complicatedly. For this reason, since the absorbent article 1D is flexibly deformed along the wearer's complicated body line, the absorbent article 1D provides the wearer with an excellent wearing feeling and improves fit and provides excellent leakage prevention.

The absorbent article of this invention (4th invention) is not restrict | limited to the said embodiment.
For example, in the above-described embodiment, in the absorbent core 40D of the absorbent body 4D, the high basis weight portion 41 is arranged at substantially equal intervals in the longitudinal direction X and the width direction Y as shown in FIGS. However, if the space 6X formed by the concave portion (low basis weight portion 42 (low basis weight portion 42X)) and the moisture-permeable back sheet 3 in the concavo-convex structure extends continuously in the longitudinal direction X, The high basic weight portions 41 may be arranged in a zigzag pattern. That is, a large number of high basis weight portions 41 are arranged at predetermined intervals in the longitudinal direction X to form a high basis weight portion row, and a plurality of high basis weight portion rows are arranged at predetermined intervals in the width direction Y. In this case, the pitches of the high basis weight portions 41 in the high basis weight portion rows adjacent to each other may be shifted. In other words, the high basis weight portion 41 is adjacent to the high basis weight portion 41 when projected in a direction (width direction Y) orthogonal to the high basis weight portion row in the predetermined high basis weight portion row. You may arrange | position so that it may not correspond with the projection image of the basic weight part 41. FIG.

The parts of only one embodiment described above can be mutually used as appropriate within each invention (first to fourth inventions) or between each invention. The following additional notes (absorbent articles) are disclosed with respect to the embodiment described above.

[1] A vertically long absorbent article comprising a top sheet disposed on the skin contact surface side, a back sheet disposed on the non-skin contact surface side, and an absorbent body interposed between both sheets,
The absorbent body is configured to include an absorbent core including an absorbent material, and the absorbent core includes a high basis weight portion in which the absorbent material is relatively large and a low basis weight in which the absorbent material is relatively small. Having a basis weight part, the high basis weight part and the low basis weight part are alternately formed in each of the longitudinal direction and the width direction of the absorbent article,
In the absorbent article, a groove is formed by recessing the top sheet and the absorbent core integrally, and the groove is at least two pieces of the side by side in the longitudinal direction or the width direction. It is formed continuously with a high basis weight part and one low basis weight part sandwiched between two high basis weight parts,
The absorbent article which the bottom wall part which defines the said groove | channel is located in the non-skin contact surface side rather than the thickness direction center of the said absorbent core.

[2] The absorbent article according to [1], wherein the vicinity of the groove is different in density between the high basis weight portion and the low basis weight portion.
[3] The groove is convexly curved outward in the width direction of the absorbent article in a plan view at both side portions along the longitudinal direction of the absorbent article in the excretory part facing portion of the absorbent article. The absorbent article according to [1] or [2], wherein the absorbent article is formed to include a vertically long shape.
[4] The low basis weight portion according to any one of [1] to [3], wherein the low basis weight portion is formed to include a linear portion extending in a longitudinal direction of the absorbent article in plan view. Absorbent article.
[5] The low basis weight portion is formed so as to include a linear portion extending in the width direction of the absorbent article in a plan view, and the groove is a length of the absorbent article in a plan view. The absorbent article according to any one of [1] to [4], wherein the absorbent article is formed so as to include a horizontally elongated shape that is convexly curved outward in the direction.
[6] The high basis weight portion is thicker than the low basis weight portion, and the absorbent core has an uneven structure in which the high basis weight portion is raised as compared to the low basis weight portion. The absorbent article according to any one of [1] to [5].
[7] In any one of the above [1] to [6], in the cross-sectional view of the absorbent core, the low basis weight portion is unevenly distributed on the skin contact surface side in the thickness direction of the absorbent core. The absorbent article as described.
[8] The absorbent article according to any one of [1] to [7], wherein the skin contact surface of the absorbent core is flat with no irregularities except for the groove formation site.
[9] In the cross-sectional view of the absorbent core, the low basis weight portion is unevenly distributed on the non-skin contact surface side in the thickness direction of the absorbent core, any one of [1] to [6] Absorbent article as described in 1.
[10] The absorbent article according to any one of [1] to [6] and [9], wherein the non-skin contact surface of the absorbent core is flat without unevenness.

[11] A vertically long absorbent article comprising a top sheet disposed on the skin contact surface side, a back sheet disposed on the non-skin contact surface side, and an absorbent body interposed between both sheets,
The absorbent body is configured to include an absorbent core including an absorbent material, and the absorbent core includes a high basis weight portion in which the absorbent material is relatively large and a low basis weight in which the absorbent material is relatively small. Having a basis weight part, the high basis weight part and the low basis weight part are alternately formed in a predetermined direction,
In the absorbent article, a groove is formed by recessing the top sheet and the absorbent core integrally,
The groove is defined by a bottom wall portion and a side wall portion standing from the bottom wall portion, and is sandwiched between at least the two high basis weight portions and the two high basis weight portions arranged in a predetermined direction. Formed with one piece of the low basis weight portion,
The absorbent article in which the tear which penetrates this low basic weight part in the thickness direction is formed in the site | part which comprises the said side wall part in the said low basic weight part.

[12] The absorbent article according to [11], wherein, in a cross-sectional view of the absorbent core, the low basis weight portion is unevenly distributed on the skin contact surface side in the thickness direction of the absorbent core.

[13] A vertically long absorbent article having a top sheet disposed on the skin contact surface side, a back sheet disposed on the non-skin contact surface side, and an absorbent body interposed between both sheets,
The absorbent body is configured to include an absorbent core including an absorbent material, and the absorbent core is adjacent to the high basis weight portion, the high basis weight portion being relatively rich in the absorbent material, and the high basis weight portion. The absorbent material has a relatively low low basis weight part, and the low basis weight part is unevenly distributed on the skin contact surface side in the thickness direction of the absorbent core,
The absorbent article has a groove in which the topsheet and the absorbent core are integrally recessed and extends in a longitudinal direction of the absorbent article, and the groove includes the high basis weight portion and the high basis weight portion. A shallow groove portion that is formed so as to straddle a low basis weight portion and is relatively shallowly recessed in the groove, and a deep groove portion that is relatively deeply recessed in the length direction of the groove. Are alternately formed along
The shallow groove part is an absorbent article having a longer length in the length direction of the groove than the deep groove part.

[14] The absorbent article according to the above [12] or [13], wherein the skin contact surface of the absorbent core is flat with no irregularities except for the groove formation site.
[15] The absorbent article according to any one of [11] to [14], wherein density is different between the high basis weight portion and the low basis weight portion in the vicinity of the groove.

[16] The groove is convexly curved outward in the width direction of the absorbent article in a plan view on both side portions along the longitudinal direction of the absorbent article in the excretory part facing portion of the absorbent article. The absorbent article according to any one of [11] to [15], which is formed so as to include a vertically long shape.
[17] The low basis weight portion according to any one of [11] to [16], wherein the low basis weight portion is formed to include a linear portion extending in a longitudinal direction of the absorbent article in plan view. Absorbent article.
[18] The low basis weight portion is formed so as to include a linear portion extending in the width direction of the absorbent article in a plan view, and the groove is a longitudinal direction of the absorbent article in a plan view. The absorbent article according to any one of [11] to [17], wherein the absorbent article is formed to include a horizontally long shape that is convexly curved outward in the direction.

[19] A vertically long absorbent article comprising a top sheet disposed on the skin contact surface side, a back sheet disposed on the non-skin contact surface side, and an absorbent body interposed between both sheets,
The back sheet has moisture permeability,
The absorbent body has a high basis weight part having a relatively high basis weight and a low basis weight part having a relatively low basis weight adjacent to the high basis weight part, The low basis weight part is integrally molded, and the concave-convex structure in which the convex part that is the high basic weight part and the concave part that is the low basic weight part are alternately arranged on the back sheet side of the absorber. Formed, and on the surface sheet side of the absorber, the low basis weight portion is unevenly distributed, the concave portion is recessed on the surface sheet side, and the convex portion is convex on the back sheet side,
An absorbent article in which a space formed by the concave portion and the back sheet extends continuously in at least the longitudinal direction.

[20] The high basis weight portion is thicker than the low basis weight portion, and the absorbent core has an uneven structure in which the high basis weight portion is raised as compared to the low basis weight portion. [11] The absorbent article according to any one of [19].

[21] A vertically long absorbent article having a top sheet disposed on the skin contact surface side, a back sheet disposed on the non-skin contact surface side, and an absorbent body interposed between both sheets,
The absorbent body has a high basis weight part having a relatively high basis weight and a low basis weight part having a relatively low basis weight adjacent to the high basis weight part, and the low basis weight part. Is unevenly distributed on the skin contact surface side in the thickness direction of the absorbent article,
The absorbent article has a groove in which the topsheet and the absorbent body are integrally recessed and extends in the longitudinal direction of the absorbent article, and the groove includes the high basis weight portion and the low basis weight portion. A shallow groove portion that is formed so as to straddle the basis weight portion and is relatively shallowly recessed in the groove, and a deep groove portion that is relatively deeply recessed along the length direction of the groove. Are formed alternately,
The shallow groove part is an absorbent article having a longer length in the length direction of the groove than the deep groove part.

[22] The absorption according to [21], wherein in the low basis weight portion, the side wall portion defining the groove has a lower basis weight than a portion located farther from the groove than the side wall portion. Sex goods.
[23] The portion corresponding to the groove on the non-skin contact surface of the absorbent body is the [21] or [22], wherein the low basis weight portion is closer to the top sheet than the high basis weight portion. The absorbent article as described.
[24] The absorbent article according to any one of [21] to [23], wherein the high basis weight part has a higher density than the low basis weight part.
[25] The absorbent article according to any one of [21] to [24], wherein the shallow groove portion has a shorter length in the longitudinal direction of the absorbent article than the high basis weight portion.
[26] The absorbent body includes the linear low basis weight portion extending in the longitudinal direction of the absorbent article, and the groove is a portion having a different length direction from the linear low basis weight portion. The absorbent article according to any one of the above [21] to [26].

[27] A vertically long absorbent article comprising a top sheet disposed on the skin contact surface side, a back sheet disposed on the non-skin contact surface side, and an absorbent body interposed between both sheets,
The absorbent body is configured to include an absorbent core including an absorbent material, and the absorbent core includes a high basis weight portion in which the absorbent material is relatively large and a low basis weight in which the absorbent material is relatively small. Having a basis weight part, the high basis weight part and the low basis weight part are alternately formed in a predetermined direction,
In the absorbent article, a groove is formed by recessing the top sheet and the absorbent core integrally,
The groove is defined by a bottom wall portion and a side wall portion standing from the bottom wall portion, and is sandwiched between at least the two high basis weight portions and the two high basis weight portions arranged in a predetermined direction. Formed with one piece of the low basis weight portion,
The absorbent article in which the tear which penetrates this low basic weight part in the thickness direction is formed in the site | part which comprises the said side wall part in the said low basic weight part.

[28] The absorbent article according to [27], wherein the vicinity of the groove is different in density between the high basis weight portion and the low basis weight portion.
[29] The groove is convexly curved outward in the width direction of the absorbent article in a plan view at both side portions along the longitudinal direction of the absorbent article in the excretory part facing portion of the absorbent article. The absorbent article according to the above [27] or [28], which is formed to include a vertically long shape.
[30] The absorbent article according to [29], wherein the low basis weight portion is formed to include a linear portion extending in a longitudinal direction of the absorbent article in plan view.
[31] The low basis weight portion is formed so as to include a linear portion extending in the width direction of the absorbent article in a plan view, and the groove is a length of the absorbent article in a plan view. The absorbent article according to any one of [27] to [30], wherein the absorbent article is formed so as to include a horizontally long shape that is convexly curved outward in the direction.
[32] The groove includes a shallow groove portion that is relatively shallowly recessed and a deep groove portion that is relatively deeply recessed, and at least a part of the deep groove portion is the low-tsubo in plan view. The absorbent article according to any one of the above [27] to [31], which overlaps with the amount part.
[33] The absorbent article according to [32], wherein the deep groove portion is located in a central portion in the width direction of the groove, and the shallow groove portion is located outward in the width direction of the deep groove portion.

[34] A longitudinal absorbent article comprising a top sheet disposed on the skin facing surface side, a back sheet disposed on the non-skin facing surface side, and a longitudinal absorbent body interposed between both sheets,
The back sheet has moisture permeability,
The absorbent body has a high basis weight part having a relatively high basis weight and a low basis weight part having a relatively low basis weight adjacent to the high basis weight part, The low basis weight part is integrally molded, and the concave-convex structure in which the convex part that is the high basic weight part and the concave part that is the low basic weight part are alternately arranged on the back sheet side of the absorber. Formed, and on the surface sheet side of the absorber, the low basis weight portion is unevenly distributed, the concave portion is recessed on the surface sheet side, and the convex portion is convex on the back sheet side,
An absorbent article in which a space formed by the concave portion and the back sheet extends continuously in at least the longitudinal direction.

[35] The absorbent article according to [34], wherein the concave portion is disposed so as to surround the convex portion, and the space continuously extends in each of a longitudinal direction and a width direction.
[36] The absorber has, on the top sheet side of the absorber, a front-side recess that is recessed on the back sheet side, corresponding to the recess of the concavo-convex structure on the back sheet side,
The absorbent article according to [34] or [35], wherein the depth of the recess is deeper than the depth of the surface-side recess.
[37] The absorbent article according to any one of [34] to [36], wherein the high basis weight part has a higher density than the low basis weight part.
[38] The space continuously extends in each of the longitudinal direction and the width direction, and the low basis weight portion in the intersection region between the space extending in the longitudinal direction and the space extending in the width direction is at a central portion of the intersection region. The absorbent article according to any one of [35] to [37], which is the thinnest.
[39] The absorbent article according to any one of [35] to [38], wherein the high basis weight portion forming the convex portion has a corner formed in an arc shape in plan view.

Hereinafter, the present invention (the first invention and the second invention) will be described more specifically with reference to examples, but the present invention is not limited to such examples.

[Example 1A]
A sanitary napkin having the same configuration as that of the napkin 1A shown in FIGS. 1 and 2 was produced and used as a sample of Example 1A. A surface sheet (details will be described later) having a two-layer structure is used as the surface sheet, a non-moisture permeable polyethylene film having a basis weight of 30 g / m ² is used as the back sheet, and a basis weight of 20 g / using air-through nonwoven m ^2, as the core wrap sheet covering the absorbent core, using absorbent paper having a basis weight of 16g / m ^2. As an absorptive core, what was manufactured according to the method mentioned above was used. The absorptive core used in Example 1 is a block-type absorptive core having the same configuration (uneven structure) as the absorptive core 40A shown in FIG. 3, and exposed softwood kraft pulp (NBKP, fiber material) as the absorptive material. And a particulate water-absorbing polymer in a weight ratio of the former: the latter = 4: 1, a mixed fiber type absorbent core, a pulp basis weight of 200 g / m ^{2 in} the entire absorbent core, and a water-absorbing polymer basis weight 50 g / m ² , basis weight of high basis weight part 300 g / m ² , high basis weight part thickness 2.0 mm, low basis weight part basis weight 140 g / m ² , low basis weight part thickness 0.8 mm, The total length in the longitudinal direction was 200 mm, and the total length in the width direction was 75 mm. Moreover, regarding the high basis weight portion, the length L2 in the longitudinal direction (see FIG. 3A) was 20 mm, and the length L3 in the width direction (see FIG. 3A) was 10 mm. Further, 18 high basis weight portions were formed per 50 cm ² area. The groove width L5 (see FIG. 3B) was 2 mm, and the groove depth L6 (see FIG. 5) was 0.5 mm.

The top sheet having a two-layer structure used in Example 1A is composed of an upper layer positioned on the skin contact surface side and a lower layer positioned on the non-skin contact surface side, and the separately manufactured upper layer and the lower layer And integrated. The upper layer was manufactured as follows. That is, first, as a non-heat-shrinkable fused fiber, a core-sheath type composite fiber (trade name NBF-SH, core: polyethylene terephthalate, sheath: polyethylene, core / sheath weight ratio = 5/5, manufactured by Daiwa Boseki Co., Ltd. The fused fiber is defibrated using a card machine to obtain a web using a fineness of 2.2 dtex and a fiber length of 51 mm, and then the web is heat treated by an air-through method (120 ° C.) to have a basis weight of 20 g / m ^2. The air-through nonwoven fabric was obtained, and the air-through nonwoven fabric was used as the upper layer. The lower layer was manufactured as follows. That is, latent crimpable fiber (core-sheath type composite fiber having heat shrinkability with ethylene-propylene random copolymer as a core component and polypropylene as a sheath component, fineness of 2.2 dtex, manufactured by Daiwabo Co., Ltd. A web having a basis weight of 20 g / m ² was produced using a card machine in the same manner as described above using a starting temperature of 90 ° C. as a raw material, and the web was used as the lower layer.

And the upper layer and the lower layer separately produced in this way are superposed to obtain a polymer, and the polymer is passed through a hot embossing roll device composed of a combination of an engraving roll and a smooth roll, and subjected to heat embossing, whereby both layers Were joined and integrated to obtain a nonwoven fabric having an embossed portion (concave portion). At that time, the engraving roll was brought into contact with the lower layer, and embossing was performed from the lower layer side. The engraving roll was set to 175 ° C, and the smooth roll was set to 125 ° C. The embossing pattern of the engraving roll is a so-called staggered pattern, and each embossing point constituting the pattern is circular (embossing area 0.047 cm ² ) and the distance (pitch) of the embossing points along the machine direction is The distance (pitch) of the emboss point along the horizontal direction was 7 mm, and the distance of the emboss point along the oblique 45 ° direction was 5 mm. The embossed area ratio at this time was 7.2%. Next, the obtained nonwoven fabric was heat-treated (air-through process) for 1 to 3 minutes in a heat dryer heated to 130 ° C. By such heat treatment of the nonwoven fabric, fibers exhibiting heat extensibility contained in the nonwoven fabric (upper layer non-heat-shrinkable fusion fibers) are stretched at portions other than the embossed portions (concave portions). Since the portion is fixed by the embossed portion, the stretched portion of the fiber loses its place in the plane direction of the nonwoven fabric and moves in the thickness direction of the nonwoven fabric. As a result, convex portions are formed in each of the plurality of regions surrounded by the embossed portions of the staggered pattern on both the skin contact surface and the non-skin contact surface of the nonwoven fabric. Thus, a surface sheet made of a nonwoven fabric having a two-layer structure having protrusions on both sides was obtained. In this surface sheet (nonwoven fabric having a two-layer structure), the fiber density of the protrusions existing on the skin contact surface is 0.04 g / cm ³ , and the fiber density of the protrusions existing on the non-skin contact surface is 0.10 g / cm ^3. The fiber density of the embossed part was 0.70 g / cm ³ . The ratio of the total area of the embossed portion to the surface area of the topsheet _{_{(q 1) (q 2)}} (q 2 / q 1) was 0.29.

[Example 2A]
A sanitary napkin was prepared in the same manner as in Example 1A except that the absorbent core shown below was used, and this was used as Example 2A.
Absorbent core used in Example 2A: Absorbent in which the uneven distribution position of the low basis weight portion in the thickness direction of the absorbent core is on the non-skin contact surface side, opposite to the absorbent core used in Example 1 Core (block type absorbent core). This absorptive core is comprised similarly to the absorptive core used in Example 1A including the dimension except the above point.

[Comparative Example 1A]
A sanitary napkin was prepared in the same manner as in Example 1A except that the absorbent core shown below was used, and this was used as Comparative Example 1A.
Absorbent core used in Comparative Example 1A: A plurality of absorbent portions having a predetermined basis weight (portions corresponding to high basis weight portions in the absorbent core used in Example 1A) are respectively in the longitudinal direction and the width direction of the absorbent core. The two absorbent parts adjacent to each other are spaced apart from each other, and there is no absorbent material between the two adjacent absorbent parts (ie, the absorbent used in Example 1A). Absorbent core (block type absorbent core) in which there is no portion corresponding to the low basis weight portion in the core. This absorptive core is comprised similarly to the absorptive core used in Example 1A including the dimension except the above point.

[Comparative Example 2A]
A sanitary napkin was prepared in the same manner as in Example 1A except that the absorbent core shown below was used, and this was used as Comparative Example 2A.
Absorbent core used in Comparative Example 2A: Absorbent material is distributed over the entire core with a uniform basis weight, does not have a low basis weight part and a high basis weight part, and does not have an uneven structure. Absorbent core with flat contact surface and non-skin contact surface (flat absorbent core). This absorptive core is comprised similarly to the absorptive core used in Example 1A including the dimension except the above point.

[Evaluation A]
For each sample (sanitary napkin) of Examples 1A to 2A and Comparative Examples 1A to 2A, the dynamic maximum absorption amount, flexibility, and air permeability were evaluated according to the following methods. The results are shown in Table 1 below.

<Evaluation method of dynamic maximum absorption>
The sanitary napkin was fixed to a sanitary short, and the sanitary short was attached to a dynamic model of a human body. The walking motion of the dynamic model is started, and 1 minute after the start of the walking motion, as the first fluid injection operation, 2 g of horse blood is injected into the sanitary napkin from the fluid excretion point of the dynamic model. Three minutes after the end of the liquid injection operation, as a second liquid injection operation, 3 g of horse blood was injected into the sanitary napkin from the liquid excretion point of the dynamic model, and further 3 minutes after the end of the second liquid injection operation, As a third liquid injection operation, 2 g of horse blood is injected into the sanitary napkin from the liquid excretion point of the dynamic model. The third and subsequent liquid injection operations are performed by injecting 2 g of horse blood into the sanitary napkin from the liquid excretion point of the dynamic model 3 minutes after the end of the previous liquid injection operation. Such liquid injection operation is repeated until the liquid (horse blood) exudes from the wing part of the sanitary napkin, and the maximum amount of liquid injected by the liquid injection operation performed before the liquid exudes is dynamically absorbed. The amount. The larger the value of the dynamic maximum absorption amount, the better the prevention of menstrual bleeding and the higher the evaluation.

<Flexibility evaluation method>
The bending stiffness of the absorbent core in the sanitary napkin is evaluated according to JIS L-1096 (General Textile Testing Method). As an evaluation device, a handometer (model: HOM-3) manufactured by Daiei Scientific Instruments Co., Ltd. is used. The slit width of the handometer is set to 40 mm. More specifically, the absorbent body (with the absorbent core coated with the core wrap sheet) is taken out from the sanitary napkin, and the hand-held meter is used to remove the absorbent body (total length in the longitudinal direction of 200 mm, width direction) The absorbent body was bent in the longitudinal direction and the width direction at a portion 100 mm from the front end portion of the total length 75 mm), and the load value at that time was measured. The smaller the load value, the better the flexibility and the higher the evaluation.

<Breathability evaluation method>
From the sanitary napkin, a laminate of a top sheet and an absorbent body (with an absorbent core covered with a core wrap sheet) is taken out, and an elliptical inlet (length 5 cm, Using an acrylic plate provided with a width of 2.2 cm and an area of 11 cm ² ), 6 g of blood clot is injected from the injection port and then left for 1 minute. Thereafter, the surface sheet was removed from the laminate, and the remaining absorbent was used as an evaluation sample to evaluate the air permeability. The air permeability was evaluated by referring to “Paper and paperboard—Air permeability test method—Gurley test machine method” prescribed in JIS P8117 (1998). Gurley test machine B type (trade name “GURLEY DENSOMETER”, Osamu Kumagai Performed by Kogyo Kogyo Co., Ltd.). Specifically, as shown in FIG. 11, an evaluation sample 90 (with an absorbent core covered with a core wrap sheet) is placed between two

acrylic plates

91 and 92 having a square shape of 50 mm in length and width. It is set on the Gurley tester with the skin contact surface of 90 in contact with one acrylic plate 91 located on the air injection side. One acrylic plate 91 has a square-shaped through hole 93 of 10 mm in length and width passing through the acrylic plate 91 in the thickness direction, whereas the other acrylic plate 92 has a through hole. Not done. Note that the weight of one acrylic plate 91 is 9.7 g, and the size of the evaluation sample 90 exceeds the size of the

acrylic plates

91 and 92. Then, the time required for 300 ml of air to pass (time required for injection, seconds) was measured by the method described in JIS P8117 (1998), and the ventilation rate (ml / second) was calculated from the measured value. The greater the value of this ventilation rate, the better the air permeability and the higher the evaluation.

As is clear from the results shown in Table 1, Examples 1A and 2A had a larger value of dynamic maximum absorption than Comparative Examples 1A and 2A, were excellent in prevention of menstrual blood leakage, and were bent. When the load value was small, the flexibility was excellent. From this result, as described above, forming a groove with a specific structure in an absorbent core (block-type absorbent core) in which a low basis weight part and a high basis weight part are formed in a specific pattern, It was suggested that it is effective in obtaining an absorbent article that excels in absorption and diffusion of excretory fluids and is less likely to cause discomfort due to wetness of the wearer. In addition, from comparison between Examples 1A and 2A and Comparative Example 1A and Comparative Example 2A, the block-type absorbent core having a concavo-convex structure is superior in air permeability as compared to a flat-type absorbent core having no concavo-convex structure. It was suggested that the ventilation effect of the air existing between the skin of the napkin wearer and the napkin is excellent.

[Example 1B]
A sanitary napkin having the same configuration as that of the napkin 1B shown in FIGS. 12 and 13 was produced and used as a sample of Example 1B. A surface sheet having a two-layer structure is used as the surface sheet, a non-moisture permeable polyethylene film having a basis weight of 30 g / m ² is used as the back sheet, and an air-through nonwoven fabric having a basis weight of 20 g / m ² is used as the side sheet. As a core wrap sheet for covering the absorbent core, an absorbent paper having a basis weight of 16 g / m ² was used. As an absorptive core, what was manufactured according to the method mentioned above was used. The absorptive core used in Example 1B has the same configuration (uneven structure) as the absorptive core 40B shown in FIG. 14, and as absorptive material, softwood bleached kraft pulp (NBKP, fiber material) and particulate This is a mixed fiber type absorbent core containing a water-absorbing polymer in a weight ratio of the former: latter = 4: 1, and has a pulp basis weight of 200 g / m ² and a water-absorbing polymer basis weight of 50 g / m in the entire absorbent core. ² , Basis weight of high basis weight part 300g / m ² , High basis weight part thickness 2.0mm, Low basis weight part basis weight 140g / m ² , Low basis weight part thickness 0.8mm, Longitudinal length The total length in the width direction was 200 mm. Moreover, regarding the high basis weight portion, the length L2 in the longitudinal direction (see FIG. 14A) was 20 mm, and the length L3 in the width direction (see FIG. 14A) was 10 mm. Further, 18 high basis weight portions were formed per 50 cm ² area. Further, the groove width L5 (see FIG. 14B) was 2 mm, and the groove depth L6 (see FIG. 16) was 0.5 mm. Further, the length L8 (see FIG. 18A) of the shallow groove portion in the length direction is 3.4 mm, and the length L9 of the deep groove portion in the length direction (see FIG. 18A) is 1. It was 0 mm.

[Comparative Example 1B]
Example 1B except that the absorbent core shown below was used, and the length L8 of the shallow groove and the length L9 of the deep groove were 1.2 mm, respectively. Similarly, a sanitary napkin was prepared and used as Comparative Example 1B.
Absorbent core used in Comparative Example 1B: Absorbent material is distributed over the entire core with a uniform basis weight, does not have a low basis weight part and a high basis weight part, and does not have an uneven structure. Absorbent core with substantially flat contact and non-skin contact surfaces. This absorptive core is comprised similarly to the absorptive core used in Example 1B including the dimension except the above point.

[Comparative Example 2B]
A sanitary napkin was prepared in the same manner as in Example 1B except that the same absorbent core as that used in Comparative Example 1B was used as the absorbent core, and this was used as Comparative Example 2B.

[Evaluation B]
For each sample of Example 1B and Comparative Examples 1B to 2B (sanitary napkins), the dynamic maximum absorption amount and flexibility were evaluated according to the methods described above. The results are shown in Table 2 below.

As is clear from the results shown in Table 2, Example 1B has a larger value of dynamic maximum absorption than Comparative Examples 1B and 2B, which is excellent in preventing menstrual blood leakage, and when folded. The load value was small and the flexibility was excellent. From this result, as described above, forming a groove with a specific structure in an absorbent core in which a low basis weight part and a high basis weight part are formed in a specific pattern, absorbs and diffuses excretory fluid quickly. It is suggested that it is effective in eliminating the discomfort caused by the wearer's wetting and obtaining an absorbent article having moderate flexibility and excellent fit despite having a leak-proof groove. It was done.

Claims

A vertically long absorbent article comprising a top sheet disposed on the skin contact surface side, a back sheet disposed on the non-skin contact surface side, and an absorbent body interposed between both sheets,
The absorbent body is configured to include an absorbent core including an absorbent material, and the absorbent core includes a high basis weight portion in which the absorbent material is relatively large and a low basis weight in which the absorbent material is relatively small. Having a basis weight part, the high basis weight part and the low basis weight part are alternately formed in each of the longitudinal direction and the width direction of the absorbent article,
In the absorbent article, a groove is formed by recessing the top sheet and the absorbent core integrally, and the groove is at least two pieces of the side by side in the longitudinal direction or the width direction. It is formed continuously with a high basis weight part and one low basis weight part sandwiched between two high basis weight parts,
The absorbent article which the bottom wall part which defines the said groove | channel is located in the non-skin contact surface side rather than the thickness direction center of the said absorbent core.
The absorbent article according to claim 1, wherein the density of the high basis weight portion and the low basis weight portion is different in the vicinity of the groove.
The groove is a vertically long shape that is convexly curved outward in the width direction of the absorbent article in a plan view at both side portions along the longitudinal direction of the absorbent article in the excretory part facing portion of the absorbent article. The absorbent article of Claim 1 or 2 currently formed so that it may contain.
The absorbent article according to any one of claims 1 to 3, wherein the low basis weight portion is formed so as to include a linear portion extending in a longitudinal direction of the absorbent article in a plan view.
The low basis weight portion is formed so as to include a linear portion extending in the width direction of the absorbent article in plan view, and the groove is outward in the longitudinal direction of the absorbent article in plan view. The absorbent article according to any one of claims 1 to 4, wherein the absorbent article is formed so as to include a horizontally long shape that is convexly curved toward the top.
The high basis weight portion is thicker than the low basis weight portion, and the absorbent core has an uneven structure in which the high basis weight portion is raised compared to the low basis weight portion. The absorbent article as described in any one of 5.
The absorbent article according to any one of claims 1 to 6, wherein in the cross-sectional view of the absorbent core, the low basis weight portion is unevenly distributed on the skin contact surface side in the thickness direction of the absorbent core. .
The absorbent article according to any one of claims 1 to 7, wherein the skin contact surface of the absorbent core is flat and has no irregularities except for the portion where the groove is formed.
The absorptivity according to any one of claims 1 to 6, wherein, in a cross-sectional view of the absorbent core, the low basis weight portion is unevenly distributed on the non-skin contact surface side in the thickness direction of the absorbent core. Goods.
The absorbent article according to any one of claims 1 to 6 and 9, wherein the non-skin contact surface of the absorbent core is flat with no irregularities.
A vertically long absorbent article comprising a top sheet disposed on the skin contact surface side, a back sheet disposed on the non-skin contact surface side, and an absorbent body interposed between both sheets,
The absorbent body is configured to include an absorbent core including an absorbent material, and the absorbent core includes a high basis weight portion in which the absorbent material is relatively large and a low basis weight in which the absorbent material is relatively small. Having a basis weight part, the high basis weight part and the low basis weight part are alternately formed in a predetermined direction,
In the absorbent article, a groove is formed by recessing the top sheet and the absorbent core integrally,
The groove is defined by a bottom wall portion and a side wall portion standing from the bottom wall portion, and is sandwiched between at least the two high basis weight portions and the two high basis weight portions arranged in a predetermined direction. Formed with one piece of the low basis weight portion,
The absorbent article in which the tear which penetrates this low basic weight part in the thickness direction is formed in the site | part which comprises the said side wall part in the said low basic weight part.
The absorbent article according to claim 11, wherein, in a cross-sectional view of the absorbent core, the low basis weight portion is unevenly distributed on the skin contact surface side in the thickness direction of the absorbent core.
A vertically long absorbent article having a top sheet disposed on the skin contact surface side, a back sheet disposed on the non-skin contact surface side, and an absorbent body interposed between both sheets,
The absorbent body is configured to include an absorbent core including an absorbent material, and the absorbent core is adjacent to the high basis weight portion, the high basis weight portion being relatively rich in the absorbent material, and the high basis weight portion. The absorbent material has a relatively low low basis weight part, and the low basis weight part is unevenly distributed on the skin contact surface side in the thickness direction of the absorbent core,
The absorbent article has a groove in which the topsheet and the absorbent core are integrally recessed and extends in a longitudinal direction of the absorbent article, and the groove includes the high basis weight portion and the high basis weight portion. A shallow groove portion that is formed so as to straddle a low basis weight portion and is relatively shallowly recessed in the groove, and a deep groove portion that is relatively deeply recessed in the length direction of the groove. Are alternately formed along
The shallow groove part is an absorbent article having a longer length in the length direction of the groove than the deep groove part.
14. The absorbent article according to claim 12 or 13, wherein the skin contact surface of the absorbent core is flat and has no irregularities except for the site where the groove is formed.
The absorbent article according to any one of claims 11 to 14, wherein the density is different between the high basis weight portion and the low basis weight portion in the vicinity of the groove.
The groove is a vertically long shape that is convexly curved outward in the width direction of the absorbent article in a plan view at both side portions along the longitudinal direction of the absorbent article in the excretory part facing portion of the absorbent article. The absorbent article according to any one of claims 11 to 15, wherein the absorbent article is formed to include
The absorbent article according to any one of claims 11 to 16, wherein the low basis weight portion is formed to include a linear portion extending in a longitudinal direction of the absorbent article in plan view.
The low basis weight portion is formed so as to include a linear portion extending in the width direction of the absorbent article in plan view, and the groove is outward in the longitudinal direction of the absorbent article in plan view. The absorbent article according to any one of claims 11 to 17, wherein the absorbent article is formed so as to include a horizontally long shape that is convexly curved toward the top.
A vertically long absorbent article comprising a top sheet disposed on the skin contact surface side, a back sheet disposed on the non-skin contact surface side, and an absorbent body interposed between both sheets,
The back sheet has moisture permeability,
The absorbent body has a high basis weight part having a relatively high basis weight and a low basis weight part having a relatively low basis weight adjacent to the high basis weight part, The low basis weight part is integrally molded, and the concave-convex structure in which the convex part that is the high basic weight part and the concave part that is the low basic weight part are alternately arranged on the back sheet side of the absorber. Formed, and on the surface sheet side of the absorber, the low basis weight portion is unevenly distributed, the concave portion is recessed on the surface sheet side, and the convex portion is convex on the back sheet side,
An absorbent article in which a space formed by the concave portion and the back sheet extends continuously in at least the longitudinal direction.
The high basis weight portion is thicker than the low basis weight portion, and the absorbent core has a concavo-convex structure in which the high basis weight portion is raised as compared with the low basis weight portion. The absorbent article as described in any one of 19.