CN106794085B

CN106794085B - Absorbent article

Info

Publication number: CN106794085B
Application number: CN201580055603.4A
Authority: CN
Inventors: 山口达之; 长岛启介; 松井学; 塚本祐贵
Original assignee: Kao Corp
Current assignee: Kao Corp
Priority date: 2014-10-30
Filing date: 2015-10-20
Publication date: 2020-03-10
Anticipated expiration: 2035-10-20
Also published as: TWI691313B; WO2016067965A1; JP2016086872A; JP6181027B2; CN106794085A; TW201628573A

Abstract

An absorbent article having an absorbent (4) between a skin-side sheet (2a, 2b) forming a skin-facing surface and a non-skin-side sheet (3) forming a non-skin-facing surface, the absorbent (4) including a longitudinally long absorbent core (40) that is long in the front-rear direction of the absorbent article, the absorbent core (40) having, at a portion facing a discharge portion: side regions (45) located on both sides in the width direction; and a central region (41) which is located on the center side in the width direction of the side regions (45) and has a larger thickness than the side regions (45); the side regions (45) are formed integrally with the central region (41), the central region (41) protrudes toward the non-skin-side sheet, and the absorbent body (4) has a non-joined region that is not joined to the non-skin-side sheet (3) in a region where the side regions (45) are located in a plan view.

Description

Absorbent article

Technical Field

The present invention relates to an absorbent article such as a sanitary napkin, a panty liner (vaginal discharge liner), or an incontinence liner.

Background

It is known that a raised portion is provided in an absorbent body of an absorbent article such as a sanitary napkin so as to follow the uneven shape of the skin of a wearer, and a groove is formed in the raised portion. For example,

patent documents

1 and 2 disclose an absorbent body having a ridge portion having a groove in the vicinity of a central portion of the absorbent body.

Documents of the prior art

Patent document

Patent document 1: japanese laid-open patent publication No. 2009-112590

Patent document 2: japanese laid-open patent publication No. 2012-125366

Disclosure of Invention

The present invention relates to an absorbent article having an absorbent body between a skin-side sheet forming a skin-facing surface and a non-skin-side sheet forming a non-skin-facing surface, the absorbent body including a vertically long absorbent core that is long in the front-rear direction of the absorbent article. The absorbent core has, at the excretion portion-corresponding portion: side regions located on both sides in the width direction; and a central region located closer to the widthwise center side than the side regions and having a thickness greater than the side regions. The side regions are formed integrally with the central region, and the central region protrudes toward the non-skin-side sheet. The absorbent body has a non-joined region that is not joined to the non-skin-side sheet in a region where the side region is located in a plan view.

Drawings

Fig. 1 is a perspective view showing a sanitary napkin according to a first embodiment of the present invention.

FIG. 2(a) is a sectional view taken along line IIa-IIa of FIG. 1, and FIG. 2(b) is a sectional view taken along line IIb-IIb of FIG. 1.

Fig. 3 is a plan view of the absorbent body of the sanitary napkin shown in fig. 1, as viewed from the non-skin-facing side.

Fig. 4 is an explanatory view of an example of a method of pressing both side portions of the central thick-walled region to form the protruding portions having a higher density than the central protruding portion and a higher grammage than the side regions, adjacent to the high-density portions.

Fig. 5 is a schematic view showing a deformed state of an absorbent body of the sanitary napkin of fig. 1 in a worn state.

Fig. 6 is a schematic view showing a main part of a fiber stacking apparatus preferably used for manufacturing the absorbent core of the sanitary napkin shown in fig. 1.

Fig. 7(a) and 7(b) are schematic views showing a cross section of the outer peripheral portion of the fiber stacking tube in the fiber stacking device shown in fig. 6 in the tube circumferential direction.

Detailed Description

The absorbent body in patent document 1 has a laminated structure including an upper layer and a lower layer, and a groove penetrating the upper layer and the lower layer is formed in a central region where a ridge portion is formed. However, since the groove is formed by hot embossing, the vicinity of the bottom of the groove is compacted, and thus there is room for improvement in soft following ability to the movement of the wearer.

In patent document 2, a raised portion including a plurality of convex portions is similarly provided in an absorbent body having a plurality of block-shaped convex portions, and the raised portion is likely to follow the movement of the wearer, but there is room for improvement in fit when a strong pressure is applied from the wearer side during wearing.

Accordingly, an object of the present invention is to provide an absorbent article which can further improve the performance of the above-described conventional art.

Hereinafter, preferred embodiments of the present invention will be described with reference to the accompanying drawings.

The sanitary napkin 1 (hereinafter also simply referred to as "napkin 1") as the first embodiment of the absorbent article of the present invention is a sanitary napkin for night use suitable for use at bedtime, and is preferably a sanitary napkin having a length of 30cm or more.

As shown in fig. 1, the sanitary napkin 1 has an absorbent main body 6 having a shape elongated in the front-rear direction, a pair of side flaps 7, and a pair of rear flaps 8, 8. The "front-back direction" of an absorbent article such as a sanitary napkin means a direction that coincides with the front-back direction of a wearer when worn. In the present specification, the front-rear direction is a longitudinal direction, and a direction perpendicular thereto is referred to as a width direction.

The sanitary napkin 1 has a front portion a, a discharge portion facing portion B, and a rear portion C in the longitudinal direction thereof, and has a pair of

side flaps

7, 7 on the left and right sides of the absorbent body 6 in the discharge portion facing portion B, and a pair of rear flaps 8, 8 on the left and right sides of the absorbent body 6 in the rear portion C. In the sanitary napkin 1 (absorbent article) or the absorbent body 6, the excretion portion-facing portion B is a portion in which the central portion in the width direction is disposed so as to face the body fluid excretion portion, which is the vaginal opening of the wearer, the front portion a is a portion disposed on the front side (ventral side) of the wearer with respect to the excretion portion-facing portion B, and the rear portion B is a portion disposed on the back side of the wearer with respect to the excretion portion-facing portion B.

The sanitary napkin 1 comprises: a skin-side sheet 2 which forms a skin-facing surface facing the skin of the wearer when worn; a non-skin side sheet 3 which forms a non-skin-facing surface facing the clothing side such as shorts when worn; and an absorbent body 4 disposed between the two

sheets

2 and 3. In the present specification, a portion where the skin-side sheet 2, the non-skin-side sheet 3, and the absorbent core 40 overlap in a plan view is referred to as an absorbent main body 6. In the sanitary napkin 1, the skin-side sheet 2 has a liquid-permeable topsheet 2a and a pair of

side sheets

2b and 2b joined to both sides thereof. The liquid-permeable topsheet 2a is disposed in the center of the absorbent body 6 in the width direction Y, over the entire length of the absorbent body 6. The side sheet 2b is joined to the topsheet 2a at a position slightly outside in the width direction from the side edge 21 in a state where the side edge 21 at the center side in the width direction of the absorbent main body is superposed on the topsheet 2 a. In the sanitary napkin 1, the widthwise inner end portions of the side sheets 2b are not joined to the front sheet 2a in the lengthwise direction. In addition, in the sanitary napkin 1, no elastic member is provided at the widthwise inner end of the side sheet 2 b. However, an elastic member for forming a three-dimensional protector may be disposed in the vicinity of the side edge portion 21, and a portion of the excretory part facing portion B having a predetermined width from the side edge portion 21 may be raised so as to be separated from the topsheet 2a by a contraction force of the elastic member when worn, thereby forming a three-dimensional protector.

The pair of

side wing portions

7, 7 and the pair of rear wing portions 8, 8 include side sheets 2b and non-skin side sheets 3 extending from both side edges of the absorbent body 4. On the surface of each of the pair of side flaps 7 including the non-skin side sheet 3, a not-shown side flap adhesive portion for fixing to the non-skin-facing surface of the crotch portion of the pants is provided, and a not-shown main body adhesive portion for fixing the main body 6 to the inner surface of the pants is provided on the non-skin-facing surface of the absorbent main body 6. In the sanitary napkin 1, the main body bonded portion is provided at least in a region overlapping with a side region of the absorbent core 40 described below in a plan view. The rear flap 8 is disposed on the inner surface of the pants when worn. Preferably, the surface of the rear wing section 8 including the non-skin side sheet 3 is also provided with a bonding section for fixing to the inner surface of the pants. The skin-side sheet 2 and the non-skin-side sheet 3 are joined to each other by an adhesive at a portion extending to the outside of the peripheral edge of the absorbent body 4, and are joined to the peripheral edge of the sanitary napkin 1 by heat sealing. The skin-side sheet 2 and the absorbent member 4, and the absorbent member 4 and the non-skin-side sheet 3 are preferably bonded to each other with an adhesive applied in a pattern such as dots, spirals, or stripes. However, the surface of the absorber 4 on the non-skin contact surface side has a non-joined region that is not joined to the non-skin side sheet in a region where the side region 45 of the absorbent core 40 described below is located.

The absorbent body 4 in the sanitary napkin 1 has an absorbent core 40 of a vertically long shape which is long in the front-rear direction of the sanitary napkin. The absorbent core 40 includes a fiber aggregate made of a fiber material such as pulp fiber or a material in which a super absorbent polymer is held between fibers of the fiber aggregate. The absorber 4 has a core sheet (not shown) covering the absorbent core 40. That is, the absorbent core 40 covers both the upper and lower surfaces with a core-wrapped sheet (not shown) including tissue paper and/or water-permeable nonwoven fabric. The core-wrapped sheet is used to prevent the material forming the absorbent core 40 from leaking out or to improve the shape retention of the absorbent core 40. The absorbent core 40 is preferably formed by wrapping a cross section in the width direction of the absorbent core 40 over the entire circumference with one core-wrapped sheet, or by wrapping a cross section in the width direction of the absorbent core 40 over the entire circumference with a plurality of core-wrapped sheets. It is also preferable that, for example, both side portions of a rectangular core-covering sheet disposed on the skin-facing surface or non-skin-facing surface of the absorbent core 40 are folded back to the other surface side of the absorbent core 40, and are laminated on both side portions of another rectangular core-covering sheet covering the other surface. The sheets of the part of the laminate may be unbonded but preferably are bonded.

As shown in fig. 1, the absorbent core 40 in the sanitary napkin 1 has a longitudinal shape that is long in the same direction as the front-back direction of the sanitary napkin 1. As shown in fig. 2(a) and 2(b), the absorbent core 40 has

side regions

45, 45 on both sides in the width direction Y; and a central region 41 located on the central side and having a thickness greater than that of the

side regions

45, 45. In the region B facing the bodily fluid excretion portion in the sanitary napkin 1, the central region 41 is a region having the central protruding portion 5 protruding toward the non-skin side sheet 3 side, i.e., downward in fig. 2, than the lower surfaces S2, S2 of the side regions 45, respectively.

In the absorbent core 40, the

side regions

45, 45 are integrally formed with the central region 41.

In the present specification, "integrally formed" means that members manufactured in different steps are integrally formed in one step using the same material, unlike a case where members manufactured in different steps are joined to each other by a joining method such as an adhesive or compression. Therefore, at the boundary between the central region 41 and the side regions 45, there is no joint or coupling between the core bodies, which occurs when the separately manufactured 2 absorbent cores are arranged side by side. In the sanitary napkin 1 of the present embodiment, since the entire absorbent core 40 is integrally formed, there is no abutting portion or joint portion between the layers between the portion 42d of the central region 41 where the central protrusion 5 is formed and the portion 42u closer to the skin side than the portion 42 d.

A method of manufacturing the absorbent core having such a structure is explained below.

The ratio of the width W1 (see fig. 2(a)) of the central protruding portion 5 to the entire width W2 of the absorbent core 40 is preferably 20% or more, more preferably 30% or more, and further preferably 80% or less, more preferably 70% or less, and further preferably 20% or more and 80% or less, and more preferably 30% or more and 70% or less. In the case where the length of the central protrusion 5 in the width direction is not constant, for example, in the case of an oval or oblong shape, the width W1 of the central protrusion 5 is the length of the portion having the longest length in the width direction, and the full width W2 of the absorbent core 40 is set to the entire width of the same position in the length direction of the absorbent core 40 in comparison with this width.

As shown in fig. 1, the central protruding portion 5 of the absorbent core 40 in the sanitary napkin 1 has a shape that is long in the longitudinal direction of the absorbent core 40, and is formed from the excretion portion-facing portion B of the sanitary napkin 1 over a part of the rear portion C. More specifically, the discharge portion facing portion B is formed in a range from the vicinity of the front end portion thereof to the vicinity of the central portion in the X direction of the rear portion C.

The central protrusion 5 is preferably formed from the drainage portion facing portion B over a part of the rear portion C in the front-rear direction X of the sanitary napkin 1 (absorbent article). The central protrusion 5 is preferably formed over 30% or more of the entire length of the sanitary napkin 1 in the front-rear direction X, more preferably over 40% or more of the entire length of the sanitary napkin 1, and even more preferably over 50% or more of the entire length of the sanitary napkin 1. The same applies to the vertical groove 50 and the high-density portion 12 described below.

As shown in fig. 2(a) and 3, a vertical groove 50 having a bottom portion on the skin-facing surface side along the longitudinal direction X of the absorbent core 40 is formed in the non-skin-facing surface of the central region 41 of the absorbent core 40. That is, the vertical grooves 50 have openings 50a on the non-skin-facing surface side of the absorbent core 40 and do not penetrate the absorbent core 40. In the sanitary napkin 1, the longitudinal grooves 50 are formed by reducing the grammage of the absorbent material of the absorbent core 40. That is, the vertical grooves 50 of the sanitary napkin 1 are not formed by compressing a part of the absorbent core 40 by embossing or the like. In the sanitary napkin 1, the number of the vertical grooves 50 provided in the central protrusion 5 is 1, and the number of the vertical grooves provided in the central protrusion 5 is not limited thereto, and a plurality of vertical grooves may be provided at intervals in the width direction Y. In the sanitary napkin 1, the longitudinal grooves 50 are disposed so as to penetrate the central protrusion 5 longitudinally along the central protrusion 5.

In the central region 41 of the absorbent core 40, as in the case of the vertical grooves 50, lateral grooves 44a are formed, which are formed by reducing the grammage of the material forming the absorbent core 40 and have a bottom on the skin-facing surface side. That is, the lateral grooves 44a also have openings on the non-skin-facing surface side of the central region 41 and are grooves that do not penetrate the absorbent core 40, as in the vertical grooves 50. The lateral grooves 44a extend in the width direction Y of the absorbent core 40.

In the sanitary napkin 1 shown in fig. 1, a plurality of transverse grooves 44a are provided at intervals in the longitudinal direction X in the central region 41. In the sanitary napkin 1, the lateral grooves 44a are provided so as to cross the central protrusion 5 along the width direction Y of the central protrusion 5.

In the central region 41 of the absorbent core 40, as shown in fig. 2(a), high grammage parts 42 are formed alternately with low grammage parts 43 forming the bottoms of the longitudinal grooves 50 in the width direction Y of the absorbent core 40, and the low grammage parts 43 extend in the longitudinal direction X of the absorbent core 40. The high grammage part 42 is a portion where the grammage of the material forming the absorbent core is relatively higher than the low grammage part 43, and the low grammage part 43 is a portion where the grammage of the material forming the absorbent core is relatively lower than the high grammage part 42.

In the central region 41 of the absorbent core 40, the ratio of the grammage of the low grammage portion 43 forming the bottom of the longitudinal groove 50 to the grammage of the high grammage portion 42 is preferably 5% or more, more preferably 10% or more, further preferably 80% or less, more preferably 70% or less, further preferably 5% or more and 80% or less, more preferably 10% or more and 70% or less. Further, the grammage of the high grammage part 42 is preferably 200g/m²Above, more preferably 300g/m²The above is preferably 800g/m²Hereinafter, more preferably 700g/m²Hereinafter, it is preferably 200g/m²Above and 800g/m²Hereinafter, more preferably 300g/m²Above and 700g/m²The following. The grammage of the low grammage part 43 is preferably 10g/m²Above, more preferably 15g/m²The above is preferably 400g/m²Hereinafter, more preferably 350g/m²Hereinafter, it is preferably 10g/m²Above and 400g/m²Hereinafter, more preferably 25g/m²Above and 350g/m²The following.

In the central region 41 of the absorbent core 40, the high grammage portion 42 is larger in not only grammage than the low grammage portion 43 forming the bottom of the longitudinal groove 50 but also in thickness than the low grammage portion 43. The ratio of the thickness of the low grammage portion 43 to the thickness of the high grammage portion 42 is preferably 5% or more, more preferably 10% or more, and further preferably 50% or less, more preferably 40% or less, and further preferably 5% or more and 50% or less, and more preferably 10% or more and 40% or less. The thickness of the high grammage portion 42 is preferably 1.5mm or more, more preferably 2mm or more, and preferably 10mm or less, more preferably 8mm or less, and preferably 1.5mm or more and 10mm or less, and more preferably 2mm or more and 8mm or less. The thickness of the low grammage portion 43 is preferably 0.08mm or more, more preferably 0.15mm or more, and further preferably 5mm or less, more preferably 4mm or less, and further preferably 0.08mm or more and 5mm or less, and more preferably 0.15mm or more and 4mm or less.

In the case where the absorbent core is configured to include the lateral grooves 44a as in the sanitary napkin 1 of the present embodiment, each of the values of the high grammage part 42 and the relationship with the low grammage part 43 may correspond to a high grammage part that does not include the lateral grooves 44 a.

(method of measuring grammage of high and low grammage parts)

The absorbent core 40 was cut along the boundary line between the high grammage portion 42 and the low grammage portion 43 using a single-blade razor manufactured by feater corporation, and small pieces of the high grammage portion 42 and the low grammage portion 43 were obtained. The portion of the high grammage portion 42 sandwiched between the side region 45 and the low grammage portion 43 or the portion sandwiched between the pair of

low grammage portions

43, 43 is cut into small pieces so as to have a predetermined area. When the small piece includes the low grammage portion 48 forming the bottom of the lateral groove 44a extending in the width direction Y, a portion surrounded by an intersection line of the high grammage portion 42 and the side region 45, the low grammage portion 43, or the low grammage portion 48 is used for measurement so that the high grammage portion 42 is cut into small pieces. The small piece of the low grammage portion 43 is cut so that a narrow portion sandwiched between the pair of

high grammage portions

42, 42 has a length of 30 mm. In the case where a small piece having a length of 30mm and not including the intersection with the low grammage portion 48 is not obtained as the small piece of the low grammage portion 43, small pieces having a length of 30mm and including as small an intersection with the low grammage portion 48 as possible are cut out and used as the small pieces of the low grammage portion 43.

The weight of these chips was measured using an electronic balance (electronic balance GR-300, manufactured by A & D, accuracy: 4 digits after decimal point). The grammage of the small piece was calculated by dividing the obtained weight by the area of the small piece in the high grammage part 42 or the low grammage part 43. The high grammage portion 42 and the low grammage portion 43 each set the average grammage of 5 chips to the grammage.

(method of measuring the thickness of the high grammage part and the low grammage part)

The thickness of the high grammage portion 42 and the low grammage portion 43 is measured by measuring the thickness of a small piece cut out for measuring the grammage of each portion. An acrylic plate 20mm in size by 20mm and 3mm in thickness was placed so that the center thereof coincided with the center of the chip, and the thickness of the sample was measured using a noncontact laser displacement meter (laser head LK-G30, displacement meter LK-GD500) manufactured by KEYENCE.

Further, the pressure during the thickness measurement was set to 0.5g/cm². When the size of the cut piece is small and it is difficult to measure the piece with a noncontact laser displacement meter, the cut piece can be measured by observing the cross section of the cut sample at a magnification of 20 to 100 times using, for example, a microscope (VHX-1000 manufactured by KEYENCE).

In the central region 41 of the absorbent core 40, the high grammage part 42 has a higher density of the absorbent member than the low grammage part 43 forming the bottom of the longitudinal groove 50. Such a configuration is obtained, for example, by pressing the central region 41 of the absorbent core 40 in the process of manufacturing the absorbent core 40. At this time, the pressure applied is concentrated on the high grammage portion 42 having a large thickness, and the low grammage portion 43 having a small thickness is not compressed because it is not subjected to the pressure applied. In this way, only the high grammage portion 42 is compressed, whereby the high grammage portion 42 is designed so that the density of the absorbent member is increased relative to the low grammage portion 43. In the central region 41 of the absorbent core 40, high grammage portions 42 and low grammage portions 48 forming the bottoms of the lateral grooves 44a are formed alternately in the longitudinal direction X of the absorbent core 40. The high grammage portion 42 also has a higher density of the absorbent member than the low grammage portion 48 forming the bottom of the lateral groove 44 a. The density was calculated by using the grammage and thickness obtained by the above measurement method.

The grammage and thickness of the low grammage portion 48 were measured by cutting out a small piece by the same method as in the case of the low grammage portion 43. The small piece of the low grammage portion 48 is cut so that a narrow portion sandwiched between the pair of

high grammage portions

42, 42 has a length of 30 mm. In the case where a chip having a length of 30mm, which does not include the intersection with the low grammage portion 43, is not obtained, a chip having a length of 30mm, which includes as small an amount as possible of the intersection with the low grammage portion 43, is cut out to be used as a chip of the low grammage portion 48. The above-described preferable grammage ratio, thickness ratio, and the like of the high grammage part 42 and the low grammage part 43 are also the same between the high grammage part 42 and the low grammage part 48.

Further, the high grammage portion 42 and the low grammage portion 43 having the grammage difference and the density difference are formed in the above-described manner, and the longitudinal grooves 50 recessed toward the skin-facing surface side in the non-skin-facing surface of the central region 41 of the absorbent core 40 are formed to extend in the longitudinal direction X of the absorbent core 40.

In the present specification, the skin-facing surface is a surface of the absorbent article or a constituent member thereof which faces the skin side of the wearer when worn, and the non-skin-facing surface is a surface of the absorbent article or a constituent member thereof which faces the side opposite to the skin side of the wearer when worn.

In the side region 45 of the absorbent core 40, as shown in fig. 2(a), high grammage parts 46 and low grammage parts 47 are alternately formed in the width direction Y of the absorbent core 40, and the low grammage parts 47 extend along the longitudinal direction X of the absorbent core 40. The grammage of the material forming the absorbent core is relatively higher in the high grammage section 46 than in the low grammage section 47, and relatively lower in the low grammage section 47 than in the high grammage section 46.

Further, since the high grammage portion 46 and the low grammage portion 47 having the grammage difference and the density difference are formed in the above-described manner, the plurality of lateral longitudinal grooves 52 recessed toward the skin-facing surface side in the non-skin-facing surface of the lateral region 45 of the absorbent core 40 are also formed to extend in the longitudinal direction X of the absorbent core 40.

In the side regions 45 of the absorbent core 40, the high grammage portion 46 has a higher density of the absorbent member than the low grammage portion 47 forming the bottom of the longitudinal groove 52. Such a constitution can be obtained as follows. The side regions 45 of the absorbent core 40 are pressurized in a step different from the step of pressurizing the central region 41. The pressure applied is concentrated on the high grammage portion 46 having a large thickness, and the low grammage portion 47 having a small thickness is not compressed because it is not subjected to the pressure applied. In this way, only the high grammage portion 46 is compressed, and thus the high grammage portion 46 is designed so that the density of the absorbent member is increased relative to the low grammage portion 47. The pressing step used in this step is contrived as follows: a measure is taken to use a pressure roller that is cut out to have a shape corresponding to the central region 41, a roller that has a pressure section only in a portion corresponding to the side region 45 of the absorbent core 40, or the like, and only the side region of the absorbent core 40 is pressurized.

In the side region 45 of the absorbent core 40, the ratio of the grammage of the low grammage portion 47 forming the bottom of the side longitudinal groove 52 to the grammage of the high grammage portion 46 is preferably 5% or more, more preferably 10% or more, and further preferably 50% or less, more preferably 40% or less, and further preferably 5% or more and 50% or less, and more preferably 10% or more and 40% or less. Further, the grammage of the high grammage part 46 is preferably 50g/m²Above, more preferably 100g/m²The above is preferably 400g/m²Hereinafter, more preferably 300g/m²Hereinafter, it is preferably 50g/m²Above and 400g/m²Hereinafter, more preferably 100g/m²Above and 300g/m²The following. The grammage of the low grammage part 47 is preferably 2.5g/m²Above, more preferably 5g/m²The above is preferably 200g/m²Hereinafter, it is more preferably 150g/m²Hereinafter, it is preferably 2.5g/m²Above and 200g/m²Hereinafter, more preferably 5g/m²Above and 150g/m²The following.

In the side regions 45 of the absorbent core 40, the high grammage portions 46 are not only heavier than the low grammage portions 47 forming the bottom portions of the side longitudinal grooves 52, but also thicker than the low grammage portions 47. The ratio of the thickness of the low grammage portion 47 to the thickness of the high grammage portion 46 is preferably 5% or more, more preferably 10% or more, and further preferably 50% or less, more preferably 40% or less, and further preferably 5% or more and 50% or less, and more preferably 10% or more and 40% or less. The thickness of the high grammage portion 46 is preferably 0.8mm or more, more preferably 1mm or more, and preferably 5mm or less, more preferably 4mm or less, and preferably 0.8mm or more and 5mm or less, and more preferably 1mm or more and 4mm or less. The thickness of the low grammage portion 47 is preferably 0.04mm or more, more preferably 0.08mm or more, and further preferably 0.4mm or less, more preferably 0.32mm or less, and further preferably 0.04mm or more and 0.4mm or less, and more preferably 0.08mm or more and 0.32mm or less.

In the case where the absorbent core is configured to include the lateral grooves 44b as in the sanitary napkin 1 of the present embodiment, each of the values of the high grammage part 46 and the relationship with the low grammage part 47 may correspond to a high grammage part that does not include the lateral grooves 44 b.

The grammage and thickness of each of the high grammage portion 46 and the low grammage portion 47 are measured in the same manner as in the high grammage portion 42 and the low grammage portion 43 described above.

Further, the high grammage portion 42 in the central region 41 where the central protrusion 5 is located has a larger grammage than the high grammage portion 46 of the side region 45, and has a larger thickness than the high grammage portion 46 of the side region 45. Thus, the thickness t1 of the central region 41 is thicker than the thickness t2 of the side regions 45, and the central protruding portion 5 protruding below the lower surface S2 of the side regions 45 is formed in the central region 41.

The ratio of the thickness t1 of the central region 41 to the thickness t2 of the side regions 45 is preferably 110% or more, more preferably 120% or more, and further preferably 400% or less, more preferably 300% or less, and further preferably 110% or more and 400% or less, and more preferably 120% or more and 300% or less. In the present embodiment, the thickness t1 of the central region 41 is the thickness of the high grammage part 42 located at the widthwise central portion of the central region 41, and the thickness t2 of the side regions 45 is the thickness of the high grammage part 46 located closest to the central region 41. When the side region 45 is provided with the high-density portion 12 adjacent to the protrusion, the thickness of the high-grammage portion 46 closest to the high-density portion 12 adjacent to the protrusion is set.

In the central protruding portion 5, the ratio of the height t protruding from the lower surface S2 of the side region 45 to the entire thickness t1 of the central region 41 is preferably 20% or more, more preferably 30% or more, and further preferably 90% or less, more preferably 80% or less, and further preferably 20% or more and 90% or less, more preferably 30% or more and 80% or less in each of the drain opposite portion B and the rear portion C. The projecting height t of the central projecting portion 5 is the same as a value obtained by subtracting the thickness t2 of the side region 45 from the entire thickness t1 of the central region 41.

In the sanitary napkin 1, the high grammage portions 46 and the low grammage portions 49 are also formed alternately in the longitudinal direction X of the absorbent core 40 in the side regions 45, and the low grammage portions 49 also extend in the width direction Y of the absorbent core 40. Thus, in the side region 45, the plurality of lateral grooves 44b are arranged at intervals in the longitudinal direction X. The low grammage portion 48 of the central region 41 and the low grammage portion 49 of the side region 45 are aligned at the boundary between the central region 41 and the side region 45 in the longitudinal direction X of the absorbent core 40, and similarly, the horizontal grooves 44a of the central region 41 and the horizontal grooves 44b of the

side regions

45, 45 are aligned at the boundary in the longitudinal direction X of the absorbent core 40.

That is, when the absorbent core 40 is viewed from the non-skin-facing surface side in plan view of the lateral grooves 44a of the central region 41 and the lateral grooves 44b of the

lateral regions

45, 1 lateral groove 44 is formed continuously from the central region 41 of the absorbent core 40 to the lateral regions 45, and the lateral grooves 44 extend over the entire width of the absorbent core 40. The plurality of transverse grooves 44 are formed at intervals in the longitudinal direction of the absorbent core 40. In other words, the low grammage portion 48 of the central region 41 and the low grammage portion 49 of the side region 45 form one low grammage portion extending continuously over the entire width of the absorbent core 40, and the grammage, thickness, and density of the material forming the absorbent core of the one low grammage portion are smaller than those of the high grammage portion 46 of the side region 45.

The transverse grooves 44 are continuous from the central region to the lateral regions, and mean that the transverse grooves are not interrupted between the central region and the lateral regions, and are continuously present from the central region to the lateral regions when the absorbent core 40 is viewed from the non-skin-facing surface side. In the sanitary napkin 1 of the present embodiment, the transverse grooves 44 and the longitudinal grooves 50 cross each other in a cross shape in plan view, but when all or part of the space in the other transverse groove is present in the extension of the space in the transverse groove on the side facing each other across the longitudinal grooves, the transverse grooves are not interrupted at the intersection with the longitudinal grooves.

The absorbent body 4 in the sanitary napkin 1 has a non-joined region that is not joined to the non-skin side sheet 3 in a region 45 '(hereinafter also referred to as a side region 45' of the absorbent body) where the side region 45 of the absorbent core 40 is located in a plan view. On the other hand, the absorbent body 4 is joined to the non-skin side sheet 3 in a region 41 '(hereinafter also referred to as a central region 41' of the absorbent body) where the central protruding portion 5 of the absorbent core 40 is located in a plan view. Therefore, as shown in fig. 2(a), in the side region 45' of the absorber 4, a space is formed between the absorbent core 40 and the non-skin-side sheet 3. In the case where the absorbent core 40 is covered with the core-covering sheet, the space may be formed between the absorbent core and the core-covering sheet, or between the core-covering sheet and the non-skin-side sheet 3, and preferably, a space is formed between the core-covering sheet and the non-skin-side sheet 3. In this case, the absorbent core 40 and the core sheet may or may not be bonded to each other. The surface of the absorbent core 40 on the non-skin-facing surface side may be bonded to the core sheet over the entire area with a pattern-coated adhesive. The skin contact surface side surface of the absorbent core 40 may be bonded to the core sheet over the entire area with a pattern-coated adhesive.

In the sanitary napkin 1, non-joined regions are present over the entire width-directional region of the side regions 45 'of the absorbent body 4 located outside the region where the central protruding portion 5 is located in the width direction, and in fig. 2(a), the side regions 45' overlap the non-joined regions. However, the present invention is not limited to this, and a part of the region 45' where the side region 45 is located in the plan view of the absorbent body 4 may be joined to the non-skin side sheet 3. For example, a configuration in which only the widthwise edge of the absorbent core 40 is joined to the non-skin side sheet may be mentioned. In addition, the following forms are also possible: only the entire region of the side region 45 'located in the excretion portion-facing portion B is made to be a non-joined region, and the front portion a and/or the rear portion C have a portion where the side region 45' of the absorbent body 4 is joined to the non-skin-side sheet 3. In addition, the following forms are possible: when the central protrusion 5 has a shape having a non-uniform width, such as an oblong shape, the side region 45 'located on the inner side in the width direction longitudinally forward or rearward of the maximum width portion of the central protrusion 5 is joined to the non-skin side sheet 3 at the side region 45' of the absorbent body 4, and the non-joined region is formed on the outer side of an imaginary line extending longitudinally forward or rearward from the maximum width portion in the longitudinal direction X. However, it is preferable that a non-joined region not joined to the non-skin side sheet 3 is formed over at least the entire region 45' in the side region 45 of the region B facing the bodily fluid excretion portion.

In the absorbent article of the present invention, the central region 41 of the absorbent core 40 is integrally formed with the side regions 45, and the central protruding portion 5 of the central region 41 having a relatively large thickness protrudes toward the non-skin side sheet 3. In addition, the side regions 45' of the absorbent body 4 located further outward in the width direction than the central protruding portion 5 have non-joined regions where the absorbent body 4 is not joined to the non-skin-facing sheet 3. Therefore, unique effects as explained below can be obtained.

First, when the wearer wears the absorbent article of the present invention, the peripheral portions of the excretory part facing portion of the absorbent article are deformed so as to follow the shape of the body. At this time, the central protruding portion 5 protruding in a direction away from the skin of the wearer allows the peripheral portion to have a pressure-absorbing region or space on the non-skin-facing surface side. Therefore, the side regions 45' and 45' of the absorbent body 4 have the cushion region between the crotch region and the center region 41' and are folded, so that a deformed shape having excellent cushioning properties can be formed (see fig. 5).

In the sanitary napkin 1 shown in fig. 2(a), the region that buffers pressure is a space formed between the side region 45' of the absorbent member 4 and the non-skin-side sheet 3. In particular, when a force is applied from the skin-facing surface side to the non-skin-facing surface side when the sanitary napkin 1 is worn, the side regions 45' are bent and moved in the direction of the non-skin-facing surface, but the regions of the side regions 45' adjacent to the central protruding portion 5 easily maintain the space between the side regions 45' and the non-skin-side sheet 3. In the sanitary napkin 1 of the present embodiment, further, the longitudinal grooves and the lateral grooves are formed in the central region 41 and the lateral regions 45 of the absorbent core 40, and the pressure applied from the product width direction can be further relaxed.

Further, since the cushion region can be formed so as to maintain the space between the central projecting portion 5 and the side region 45', an air-permeable passage is formed in a region close to the central region 41 having a large absorption capacity and holding a large amount of excretory fluid, and a feeling of stuffiness can be reduced.

Furthermore, the central protruding portion 5 protruding toward the skin-side sheet 3 functions as a cushion pad, and can softly receive pressure even when strong pressure, for example, from the skin-facing surface side toward the non-skin-facing direction is applied to the absorbent article from the bodily fluid excretion portion of the wearer after the excretion liquid is absorbed by the absorbent article, and a space for the central protruding portion 5 to expand can be secured by the cushion region, so that the wearer can be given a soft wearing feeling, and the excretion liquid can be prevented from leaking from the central protruding portion 5.

These effects are particularly preferable in the case where the absorbent article is a sanitary napkin, since they can provide a soft touch feeling to the sensitive vaginal opening and the vicinity thereof. In the case of an absorbent article having a fixing mechanism to underwear or the like on the non-skin side sheet 3, since the side regions 45 and the non-joined regions of the non-skin side sheet 3 are present, the absorbent core 40 is less susceptible to twisting, wrinkling, or the like of the underwear or the like, and the advantage of the above-described effect is great. This advantageous effect is particularly advantageous when the fixing means is provided on the non-skin contact surface of the portion of the non-skin-side sheet facing the lateral region.

The absorbent core 40 of the sanitary napkin 1 of the present embodiment has a protrusion adjacent to the high-density portion 12, and the protrusion adjacent to the high-density portion 12 is adjacent to the central region 41 of the

side regions

45 and 45, and has a higher density than the central region 41. In comparison between the high grammage portion 42 without longitudinal grooves and lateral grooves in the central region 41 and the high-density portion 12 adjacent to the protrusion, the density of all the constituent materials such as fibers and absorbent polymers forming the absorbent core means that the high grammage portion 42 is relatively low in density compared to the protrusion adjacent to the high-density portion 12.

In the sanitary napkin 1, the side regions 45 having a relatively lower grammage and a relatively lower density than the adjacent high-density portions 12 of the protrusions are disposed further on the outer side in the width direction than the adjacent high-density portions 12 of the protrusions.

In the case where the protrusions adjacent to the high-density portion 12 are formed by the method shown in fig. 4, the density on the non-skin-facing surface side is higher than the density on the skin-facing surface side, but the density of the protrusions adjacent to the high-density portion 12 is measured by cutting the entire absorbent core in the thickness direction.

The density of the high-density portion 12 adjacent to the protrusion is 110% or more, preferably 120% or more, and further preferably 400% or less, and more preferably 300% or less, and further preferably 110% or more and 400% or less, and further preferably 120% or more and 300% or less, with respect to the density of the high grammage portion 42 having no longitudinal grooves and no lateral grooves in the central region 41.

The density of the high-density portion 12 adjacent to the protruding portion is 150% or more, preferably 160% or more, further preferably 500% or less, more preferably 400% or less, further preferably 150% or more and 500% or less, more preferably 160% or more and 400% or less, with respect to the density of the side region 45.

[ method of calculating Density of Central region ]

In the absorbent core 40, a test piece having a size of 3mm in the product width direction and 30mm in the product length direction was cut out using a single-blade razor manufactured by feater corporation so as to have a predetermined area. First, a test piece of the high grammage portion 42 having no longitudinal grooves and no lateral grooves in the central region 41 was cut out, and the mass thereof was measured using an electronic balance (electronic balance GR-300 manufactured by a & D company, accuracy: 4 decimal places). Next, the cut sample is observed at a magnification of 20 to 100 times using, for example, a microscope (VHX-1000, KEYENCE Co., Ltd.) to measure the thickness. The number of test pieces to be measured was set to 5, and the average value was set to the thickness of the central region. The density of the central region was calculated by dividing the mass measured above by the volume of the test piece (thickness x length in the product width direction x length in the product length direction).

[ method of calculating Density of high-Density portion adjacent to projection ]

A plurality of test pieces each having a size of 3mm in the width direction of the product and 30mm in the length direction of the product were continuously cut from the center of the product in the width direction of the absorbent article (product) toward the end of the product, and the mass thereof was measured using an electronic balance (GR-300, manufactured by A & D, accuracy: 4 decimal places). Then, the cut sample is observed at a magnification of 20 to 100 times using, for example, a microscope (VHX-1000 manufactured by KEYENCE) to measure the thickness.

The test pieces cut out were cut out from 5 absorbent articles, and the average value of the measured test pieces at the same position of each 5 absorbent cores 40 was set as the thickness of the test piece. The measured mass was divided by the volume of the test piece (thickness × length in the product width direction × length in the product length direction), and the density of the test piece cut out from each part was calculated.

With respect to each of the obtained test pieces, the density ratio (former/latter) of the test piece cut from the product center side at the center side in the product width direction and the test piece cut from the portion adjacent to the outer side in the product width direction in order from the test piece cut from the product center side was calculated, and when the density ratio reached 0.5 or less, the density of the test piece on the outer side in the product width direction among the 2 test pieces was set as the density of the protrusion adjacent to the high-density portion 12.

In the sanitary napkin 1 of the present embodiment, as shown in fig. 4, the protrusion-adjacent high-density portion 12 is formed by compressing both widthwise side portions 12 'of the central region 41 of the absorbent core 40, which are formed to have the same thickness as the portion 42' to be the high grammage portion 42, at the time of manufacturing the sanitary napkin. With such a configuration in the central region 41, the following effects can be exhibited.

First, the protrusion portion adjacent to the high-density portion 12 has a deformation resistance against deformation when pressure from the wearer is applied to the excretory part-facing portion, so the side regions 45 of the absorbent core 40 are easily deformed while maintaining a space between the central protrusion portion 5 and the side regions 45. Therefore, the effects of the present invention described above can be more easily exhibited.

In addition, the present configuration is also advantageous in terms of absorption performance. First, the bodily fluid is discharged to the central protrusion 5 of the central region 41 at the drainage portion facing portion B. At the side of the central region 41, there is a protrusion formed by compressing the central protrusion 5 adjacent to the high-density portion 12. Therefore, the body fluid diffused in the width direction Y and the thickness direction is guided to the high-density portion. The reason why the protrusions are adjacent to the high-density portion 12 is that the absorbent material has a higher grammage than the side region 45, and therefore has a high ability to hold body fluid. Therefore, the body fluid is blocked at both side portions of the central region 41, and hardly reaches both side portions in the width direction of the sanitary napkin 1. Therefore, in the sanitary napkin 1, the side leakage of body fluid is easily suppressed.

The protrusion portion adjacent to the high-density portion 12 will be described more specifically.

The protrusion-adjacent high-density portion 12 in the sanitary napkin 1 is formed by manufacturing an absorbent core 40A shown in fig. 4(a) using a fiber stacking apparatus, the main portion of which is shown in fig. 6, and then compressing both side portions of a central thick region 41' of the absorbent core 40A, and the absorbent core 40A has a central thick region 41' which includes the portion 12' where the protrusion is adjacent to the high-density portion 12 and is formed thick. In the sanitary napkin 1, the fixed portions of the central thick-walled region 41' on both the left and right sides of the portion to be the central protruding portion are compressed, thereby reducing the thickness, and this portion is formed as a region having a higher density than the uncompressed central protruding portion 5, with the protrusion adjoining the high-density portion 12. In addition, the protrusion-adjacent high-density portion 12 has a higher grammage of the absorbent material than the other portions of the side region 45, and therefore has sufficient absorption capacity, and prevents body fluid from reaching the side edges of the absorbent core 40. Therefore, leakage of body fluid from the side portions of the sanitary napkin 1 is easily prevented. In the sanitary napkin 1 of the present embodiment, the protrusion-adjacent high-density portion 12 has substantially the same thickness as the portion of the side region 45 where the longitudinal grooves 52 and the lateral grooves 44 are not present, but is not limited thereto, and the protrusion-adjacent high-density portion 12 may have a thickness smaller than that of the central protruding portion 5 but thicker than that of the side region 45.

In the sanitary napkin 1, the longitudinal grooves 50 of the central protrusion 5 have a width-directional length of the bottom portion 50b smaller than that of the opening portion 50 a. More specifically, as shown in fig. 2(a) and 2(b), the longitudinal groove 50 of the central protrusion 5 has a width-directional length that gradually decreases from the opening 50a toward the bottom 50b, and the longitudinal groove 50 has a substantially inverted V-shape extending from the non-skin-facing surface side toward the skin-facing surface side when viewed in a cross-sectional view in the width direction. In addition to this, the sheet may have a stepped cross-sectional shape, but when pressure is applied from both sides in the width direction in the case of a substantially inverted V shape, the non-skin-facing surface of the central region 41 is largely deformed and the amount of deformation of the skin-facing surface is small, so that a soft feeling can be obtained without reducing the absorption area at the excretory part-facing portion. This effect is particularly effective when the high-density portion 12 is adjacent to the projection.

The width-directional length La of the opening 50a of the vertical groove 50 of the central protrusion 5 is preferably 0.5mm or more, more preferably 1mm or more, and further preferably 5mm or less, more preferably 4mm or less, and the width-directional length Lb of the bottom portion 50b is preferably 1mm or less, and further preferably 0.5mm or less. The lower limit of the width direction length Lb of the bottom portion 50b is 0 (zero).

The depth of the vertical groove 50 is preferably 0.5mm or more and 5.0mm or less, and more preferably 1.0mm or more and 3.0mm or less. The difference in the width-directional length between the opening 50a and the bottom 50b of the vertical groove 50 (La — Lb) is preferably 0.5mm to 3mm, and more preferably 1mm to 2 mm.

The ratio (depth/difference (La — Lb)) of the depth of the vertical groove 50 to the difference (La — Lb) in the width direction between the opening 50a and the bottom 50b is preferably 0.5 to 20, and more preferably 1 to 10. Within this range, the shape of the vertical groove during wearing is easily stabilized, and a preferable shape for absorbing excrement is easily maintained.

Further, the bottom portion 50b of the vertical groove 50 is located below the lower surface S2 of the side region 45. The position of the lower surface S2 of the side region 45 referred to herein is the lower surface of the high grammage portion 46 in the portion of the side region 45 adjacent to the central region 41. The bottom portions 50b of the vertical grooves 50 are preferably located below the lower surfaces S2 of the side regions 45 in the longitudinal direction X of the absorbent core 40 over the entire central region 41. With this configuration, excessive deformation of the sanitary napkin during wearing can be easily suppressed, and a proper fit feeling can be easily provided.

Further, in each of the central region 41 and the side regions 45 of the absorbent core 40, the non-skin-facing surface has an uneven shape due to the presence of the lateral grooves and the longitudinal grooves, and the skin-facing surface is flat.

According to the sanitary napkin 1 of the present embodiment, the transverse grooves 44 are formed in the central region 41 having the central projecting portion 5, the transverse grooves 44 are shallow in depth, the bottom portion 44d reaches a position closer to the non-skin-side surface than the lower surface S2 of the side region 45, and also extends from the central region 41 to the side region 45, and the transverse grooves 44 are formed by reducing the grammage of the material forming the absorbent core, so that the central projecting portion 5, which is generally likely to be an obstacle to bending, is provided, but the sanitary napkin is rich in deformability, and is less likely to cause wrinkles on the skin-facing surface of the sanitary napkin 1. Therefore, as shown in fig. 5, the absorbent body 4 and the sanitary napkin 1 including the same can be deformed so that the overall shape thereof follows the shape of the wearer's body fluid excretion portion or gluteal fold while the non-skin-facing surface thereof follows the shape of the wearer's body fluid excretion portion or gluteal fold, and therefore, the absorbent body is excellent in fit to the unevenness of the body and also excellent in deformation following the wearer's movement, and is less likely to cause discomfort due to wrinkles or bending of the absorbent core.

With respect to this effect, the bottom portion 44d of the lateral groove 44 is further improved when the entire region of the central region 41 in the width direction Y of the absorbent core 40 is located below the lower surface S2 of the lateral region 45.

From the viewpoint of more reliably exhibiting such an effect, the ratio of the depth of the lateral groove 44a (44) of the central region 41 to the thickness t1 of the central region 41 is preferably 50% or more, more preferably 60% or more, and further preferably 95% or less, more preferably 90% or less, and further preferably 50% or more and 95% or less, and further preferably 60% or more and 90% or less.

The width W of the lateral groove 44 is preferably 0.2mm or more, more preferably 0.5mm or more, and preferably 3mm or less, more preferably 2mm or less, and preferably 0.2mm or more and 3mm or less, more preferably 0.5mm or more and 2mm or less. As shown in fig. 1, the width W of the transverse grooves 44 is the dimension in the longitudinal direction X of the absorbent core.

In the sanitary napkin 1, since the high grammage portion 42 in the central region 41 has a higher density than the low grammage portion 43, the body fluid absorbed through the lateral grooves 44 is quickly absorbed into the high grammage portion 42. Therefore, the bodily fluid is absorbed along the lateral grooves 44 in the longitudinal direction of the absorbent core 40, and thus the bodily fluid absorption in the central region 41 can be efficiently performed. As a result, the suppression of liquid leakage from the absorbent core 40 is improved. In addition, in the side region 45, the density of the high grammage portion 46 is higher than that of the low grammage portion 47, and therefore the same effect can be obtained.

In each of the central region 41 and the side regions 45, the ratio of the density of the low grammage part to the density of the adjacent high grammage part is preferably 5% or more, more preferably 10% or more, and further preferably 50% or less, more preferably 40% or less, and further preferably 5% or more and 50% or less, and further preferably 10% or more and 40% or less.

In the sanitary napkin 1, the lateral longitudinal grooves 52 extending in the longitudinal direction are also provided in the lateral regions 45. In the lateral longitudinal grooves 52, the opening 52a on the non-skin-facing surface side and the bottom portion 52b on the skin-facing surface side have substantially the same length in the width direction Y. Here, "substantially the same" means that the difference in the width direction length between the opening and the bottom at the same position in the length direction is within 5%. With this configuration, since the compression force received by the sanitary napkin 1 from the legs of the user during wearing is uniformly transmitted to the lateral longitudinal grooves 52 and the lateral longitudinal grooves 52 are uniformly compressed, the reaction of the compression force received by the user from the sanitary napkin 1 can be alleviated, and the uncomfortable feeling experienced by the user during wearing the sanitary napkin 1 can be eliminated. Further, if the opening 52a of the side longitudinal groove 52 is configured to be wider than the bottom portion 52b, the opening is deformed more largely by the compressive force received from the base of the leg of the user during wearing of the sanitary napkin 1, and the side edge portion of the sanitary napkin 1 may be deformed so as to curl toward the user. Such deformation is caused by the side edge portion of the sanitary napkin 1 being warped toward the skin of the wearer, and therefore the sanitary napkin 1 may strongly abut against the groin portion or the skin of the wearer may be spaced from the surface of the sanitary napkin 1 at the center portion of the sanitary napkin 1. However, by making the width direction lengths of the opening 52a and the bottom 52b substantially the same, the risk of occurrence of such a problem can be reduced. Further, the stability of the shape of the vertical groove 50 in the central region 41 in the present invention is also promoted.

The lateral longitudinal grooves 52 are preferably adjacent to the high-density portion 12 adjacent to the protruding portion. With this configuration, the absorbent core 40 in contact with the lateral side of the lateral longitudinal grooves 52 and the absorbent core 40 in contact with the central side of the lateral longitudinal grooves 52 have different hardness, and the difference in hardness makes it easy for the sanitary napkin 1 to bend in the direction opposite to the skin of the user with the lateral longitudinal grooves 52 as the base axis, and the shape of the sanitary napkin 1 while being worn is more stable, so that the discomfort felt by the user when wearing the sanitary napkin 1 can be reduced, and the central portion of the sanitary napkin 1 can be brought into closer contact with the skin of the user, and liquid can be absorbed more efficiently. Further, by making the high-density portion, which is responsible for the action of absorbing and capturing the liquid, adjacent to the lateral longitudinal grooves 52, which are relatively low in density, the following effects are exhibited: liquid is prevented from seeping to the side of the high-density portion, and the liquid is fixed in the region closer to the central region of the sanitary napkin 1, thereby preventing the liquid from leaking from the side edge portion of the sanitary napkin 1.

Preferably, the bottom surface 50a of the vertical groove 50 in the central region 41 is located closer to the non-skin-facing surface side than the bottom surface 52a of the lateral vertical groove 52. With this configuration, first, the side portions of the sanitary napkin 1 are bent in the direction opposite to the skin of the wearer with the longitudinal grooves 50 of the bottom surface on the side other than the skin-facing surface as the base axes, and second, the side portions of the sanitary napkin 1 are bent in the direction opposite to the skin of the wearer with the longitudinal grooves 52 of the bottom surface on the side other than the skin-facing surface as the base axes, whereby the shape of the sanitary napkin 1 can be further stabilized while being worn.

The absorbent core 40 of the sanitary napkin 1 can be manufactured by, for example, manufacturing the absorbent core 40A using a fiber stacking apparatus 53 (see fig. 6), and then performing the process shown in fig. 4, wherein the fiber stacking apparatus 53 includes: a fiber accumulating cylinder 54 having an accumulating recess 55 on an outer peripheral surface thereof and rotating in one direction R; and a duct 59 for supplying the absorbent core forming material to the outer peripheral surface of the fiber accumulating cylinder 54 in a scattered state. In fig. 4, the following is shown: the absorbent core 40A having the central thick region 41 'in the central portion in the direction CD orthogonal to the conveyance direction MD is introduced between the pressure roller 61 having the concave portion 62 in a part of the peripheral surface and the smooth roller 63 having a smooth peripheral surface, and the portion 12' adjacent to the portion to be the central region 41 is strongly pressed, thereby forming the absorbent core 40 having the protrusion portion adjacent to the high-density portion 12. In fig. 4, the portion to be the central region 41 where the central protruding portion 5 is formed is not pressurized, but either or both of the portion to be the central region 41 and the portion to be the side region 45 may be compressed under pressure weaker than the portion 12' to be the protrusion adjacent to the high-density portion 12.

In the fiber accumulating device 53 shown in fig. 6, a plurality of collecting recesses 55 are formed at regular intervals in the circumferential direction of the outer peripheral surface of the fiber accumulating cylinder 54. The bottom surface 56 of the collection recess 55 includes a mesh plate or the like, and has a plurality of fine holes functioning as suction holes.

As shown in fig. 7(a), a recess 56a for forming the central thick region 41' is formed in a part of the bottom surface 56 of the concentration recess 55. At the bottom of the collecting recessed portion 55, gas

impermeable members

57 and 58 are disposed to form low grammage portions such as the

low grammage portions

43 and 48. The

members

57 and 58, which are difficult to ventilate, may be fixed so as to protrude from the bottom surface of the collecting recessed portion 55, and may be non-breathable members, such as metal and plastic.

Similarly to a known fiber accumulating apparatus having a fiber accumulating cylinder, a material for forming the absorbent core is supplied into the conduit while sucking from the bottom surface of the collecting recessed portion 55, and the material for forming the absorbent core is accumulated in the collecting recessed portion 55 in a specific shape as shown in fig. 7 (b). The absorbent core 40A is obtained by releasing the deposit 4' from the collecting recess 55. The absorbent core 40A may be appropriately compressed by being pressed between a pair of rollers or the like before or after being coated with the core sheet. As shown in fig. 7(b), the portions including the core forming material deposited on the difficult-to-air-

permeable members

57, 58 become the low grammage portion 43 and the like, and the portions deposited on the bottom surface not including the difficult-to-air-

permeable members

57, 58 become the high grammage portion 42 and the like. As described above, the central region 41 of the absorbent core 40A is pressurized to form the high grammage portions 42 having a higher density than the low grammage portions 43 in the central region 41, and the side regions 45 are pressurized separately from the central region 41 to form the high grammage portions 46 having a higher density than the low grammage portions 47 in the side regions 45. Alternatively, the pressing (compression) for forming the protrusion adjacent to the high-density portion 12 in the central thick-walled region 41' of the absorbent core 40A may be performed before or after the covering with the core sheet. The pressing (compression) for forming the protrusion adjacent to the high-density portion 12 may be performed simultaneously with the pressing of the central region 41 by using a roller having a step difference in the peripheral surface, or may be performed simultaneously with the pressing of the side regions 45. Further, by designing the step formed on the roller circumferential surface to have an appropriate size, the pressurization of the central region 41 and the pressurization of the side regions 45 can be performed simultaneously. Further, the pressurization of the central region 41 and the pressurization of the side regions 45 may be performed in different steps, or the pressurization may be performed in different steps before the pressurization of the central region 41, during the pressurization of the central region 41 and the pressurization of the side regions 45, and after the pressurization of the side regions 45. In the case of producing an absorbent core containing a water-absorbent polymer, it is preferable to provide an introduction section for the water-absorbent polymer in the middle of the duct.

As the front sheet 2a and the non-skin side sheet 3, the same sheets as those conventionally used in the art can be used without particular limitation. For example, a nonwoven fabric or a perforated film having liquid permeability may be used as the topsheet 2 a. As the non-skin side sheet 3, a liquid impermeable film made of a synthetic resin, or a nonwoven fabric having high water repellency against water pressure such as a spunbond-meltblown-spunbond laminated nonwoven fabric can be used. As the side sheet 2b, a nonwoven fabric having high water repellency against water pressure, for example, a spunbond-meltblown-spunbond laminate nonwoven fabric or the like can be used.

The present invention has been described above based on preferred embodiments thereof, but the present invention is not limited to the above embodiments.

For example, in the lateral region 45, either or both of the lateral transverse grooves 44b and the lateral longitudinal grooves 52 may be absent. Either or both of the lateral transverse grooves 44b and the lateral longitudinal grooves 52 may be formed on the skin-facing surface side of the absorbent core 40.

The lateral grooves 44 continuous from the central region 41 to the side regions 45 may be formed only in the excretion portion-corresponding portions of the absorbent article, or may be formed only in the rear portion.

The absorbent core may contain only a fiber material such as pulp fiber, or may contain both a fiber material and a super absorbent polymer. As the fiber material, various fiber materials conventionally used in the absorber of absorbent articles such as sanitary napkins, panty liners, disposable diapers and the like can be used without particular limitation, and for example, short fibers of cellulose fibers such as pulp fibers, rayon fibers, cotton fibers and the like, short fibers of synthetic fibers such as polyethylene and the like can be used. These fibers may be used alone in 1 kind or in combination of 2 or more kinds. The fiber material is preferably wholly or partially pulp fibers, and the proportion of the pulp fibers in the fiber material is preferably 50 to 100 mass%, more preferably 80 to 100 mass%, and still more preferably 100 mass%. In addition, the absorbent core may contain a deodorant, an antimicrobial agent, or the like, as necessary, in addition to the super absorbent polymer.

In the above embodiment, the density of the high grammage part is made higher than that of the low grammage part, but the densities of the two parts may be made the same by omitting the pressing step of the absorbent core.

The absorbent article of the present invention may be other absorbent articles such as a panty liner (vaginal discharge protector), an incontinence pad, and a disposable diaper, in addition to the sanitary napkin. The requirements of the omitted portions of the one embodiment and of the only one embodiment can be applied to other embodiments as appropriate, and the requirements of the embodiments can be replaced with each other as appropriate.

With regard to the above embodiment, the present invention further discloses the following absorbent article.

[ 1 ] an absorbent article having an absorbent body between a skin-side sheet forming a skin-facing surface and a non-skin-side sheet forming a non-skin-facing surface, the absorbent body including a vertically long absorbent core that is long in the front-rear direction of the absorbent article, the absorbent core having, at a discharge portion facing portion: side regions located on both sides in the width direction; and a central region located on the width direction central side of the side regions and having a thickness larger than that of the side regions; the side regions are formed integrally with the central region, the central region protrudes toward the non-skin-side sheet, and the absorbent body has a non-joined region that is not joined to the non-skin-side sheet in a region where the side regions are located in a plan view.

< 2 > the absorbent article according to the above < 1 >, wherein the side regions have high-density portions having a higher density than the central region in portions adjacent to the central region.

< 3 > the absorbent article according to < 1 > or < 2 > above, wherein a longitudinal groove having a bottom portion on the skin-facing surface side along the longitudinal direction of the absorbent core is formed on the non-skin-facing surface side of the central region, and the length of the bottom portion in the width direction of the longitudinal groove is narrower than the opening portion.

< 4 > the absorbent article according to < 3 > above, wherein the longitudinal grooves have a width-directional length that gradually decreases from the opening toward the bottom.

< 5 > the absorbent article according to any one of the above < 1 > to < 4 >, wherein a central transverse groove extending in the width direction of the absorbent core is formed in the central region.

[ 6 ] the absorbent article according to any one of the above-mentioned items < 1 > to < 5 ], wherein lateral longitudinal grooves extending in the longitudinal direction of the absorbent core are formed in the lateral regions.

< 7 > the absorbent article according to < 6 > above, wherein lateral transverse grooves extending in the width direction of the absorbent core are formed in the lateral regions.

< 8 > the absorbent article as defined in any one of above < 3 > to < 7 >, wherein either or both of the longitudinal grooves and the transverse grooves are formed by reducing the grammage of the absorbent material of the absorbent core.

[ 9 ] the absorbent article according to any one of the above [ 3 ] to [ 8 ], wherein each of the central region and the side regions of the absorbent core has a non-skin-facing surface having an uneven shape and a flat skin-facing surface.

< 10 > the absorbent article according to any one of the above < 3 > to < 9 >, wherein the central region of the absorbent core has a high grammage part having a higher grammage than the low grammage part forming the bottom of the longitudinal groove.

< 11 > the absorbent article as stated in above < 10 >, wherein in said central region, the density of said absorbent member is higher in said high grammage portion than in said low grammage portion.

[ 12 ] the absorbent article according to any one of the above-mentioned items < 6 > to < 11 ], wherein the side regions of the absorbent core have high grammage parts having a higher grammage than the low grammage parts forming the bottoms of the longitudinal grooves.

< 13 > the absorbent article according to the above < 12 >, wherein the absorbent member in the high grammage part has a higher density than the low grammage part in the side region.

< 14 > the absorbent article according to any one of the above < 1 > to < 13 >, wherein a ratio of the width of the central protrusion to the entire width of the absorbent core is 20% or more and 80% or less.

[ 15 ] the absorbent article according to any one of the above-mentioned items < 1 > to < 14 ], wherein the ratio of the thickness of the central region to the thickness of the side regions is 110% or more and 400% or less.

[ 16 ] the absorbent article according to any one of the above-mentioned < 10 > to < 15 ], wherein, in the central region of the absorbent core, a ratio of a grammage of the low grammage part to a grammage of the high grammage part is 5% or more and 80% or less.

[ 17 ] the absorbent article according to any one of the above-mentioned items < 7 > to < 16 ], wherein, at a boundary portion between the central region and the side regions, the lateral grooves of the central region and the lateral grooves of the side regions are aligned in position in the longitudinal direction of the absorbent core.

< 18 > the absorbent article according to any one of the above < 3 > to < 17 >, wherein the bottom of the longitudinal groove in the central region is located below the lower surfaces of the side regions.

< 19 > the absorbent article according to any one of the above < 3 > to < 17 >, wherein the bottom of the longitudinal groove in the central region is present at substantially the same position as the lower surface of the side region.

The absorbent article according to any one of the above items < 3 > to < 17 > wherein the bottom of the longitudinal groove in the central region is located above the lower surfaces of the side regions.

[ 21 ] the absorbent article according to any one of the above-mentioned < 5 > to < 20 ], wherein a ratio of a depth of the lateral grooves in the central region to an entire thickness of the absorbent core in the central region is 50% or more and 95% or less.

[ claim 22 ] the absorbent article according to any one of the above-mentioned < 1 > to < 21 >, wherein a ratio of a height of the central protruding portion protruding from the lower surface of the side region at the excretion portion-facing portion to an entire thickness of the central region is 20% or more and 90% or less.

< 23 > the absorbent article according to < 22 > above, wherein the ratio of the height of the central protrusion protruding from the lower surfaces of the side regions at the rear portion to the entire thickness of the central region is 20% or more and 90% or less.

< 24 > the absorbent article according to any one of the above < 1 > to < 23 >, wherein the absorbent article has a front portion, a discharge portion facing portion and a rear portion in a longitudinal direction thereof, and has a pair of side wing portions on both left and right sides of an absorbent main body which is a region where the skin-side sheet, the non-skin-side sheet and the absorbent core overlap in a plan view in the discharge portion facing portion.

< 25 > the absorbent article according to any one of the above < 1 > to < 24 >, wherein the rear portion has a pair of rear wing portions on both left and right sides of the absorbent main body.

< 26 > the absorbent article according to any one of the above < 1 > to < 25 >, wherein the absorbent article is a sanitary napkin.

Industrial applicability

The absorbent article of the present invention has excellent fit when worn, and particularly has excellent fit when a high pressure is applied.

Claims

1. An absorbent article having an absorbent body between a skin-side sheet forming a skin-facing surface and a non-skin-side sheet forming a non-skin-facing surface, the absorbent body including a vertically long absorbent core that is long in a front-rear direction of the absorbent article, the absorbent article characterized in that:

the absorbent article has a front portion, a discharge portion facing portion, and a rear portion in the longitudinal direction thereof,

the absorbent core has, at the excretion portion-facing portion: side regions located on both sides in the width direction; and a central region located on the width direction central side of the side regions and having a thickness larger than that of the side regions;

the side regions are integrally formed with the central region,

the central region protrudes toward the non-skin-side sheet,

a longitudinal groove having a bottom portion on the skin-facing surface side along the longitudinal direction of the absorbent core is formed on the non-skin-facing surface side of the central region,

the absorbent body has a non-joined region that is not joined to the non-skin-side sheet in a region where the side region is located in a plan view,

a high density portion having a higher density than the central region is provided in a portion of the side region adjacent to the central region,

the high-density portion has the same thickness as or is thicker than a portion of the side region where the groove is not present.

2. The absorbent article of claim 1, wherein:

the bottom of the vertical groove has a width-directional length smaller than that of the opening.

3. The absorbent article of claim 2, wherein:

the length of the longitudinal groove in the width direction gradually becomes narrower from the opening portion toward the bottom portion.

4. The absorbent article of claim 1, wherein:

a central transverse groove extending in the width direction of the absorbent core is formed in the central region.

5. The absorbent article of claim 4, wherein:

lateral longitudinal grooves extending in the longitudinal direction of the absorbent core are formed in the lateral regions.

6. The absorbent article of claim 5, wherein:

lateral transverse grooves extending in the width direction of the absorbent core are formed in the lateral regions.

7. The absorbent article of claim 1, wherein:

the longitudinal grooves are formed by reducing the grammage of the absorbent material of the absorbent core.

8. The absorbent article of claim 4, wherein:

the central transverse groove is formed by reducing the grammage of the absorbent material of the absorbent core.

9. The absorbent article of claim 1, wherein:

the central region of the absorbent core has a high grammage part having a higher grammage than a low grammage part forming the bottom of the longitudinal groove.

10. The absorbent article of claim 9, wherein:

in the central region, the density of the absorbent member in the high grammage portion is higher than that of the low grammage portion.

11. The absorbent article of claim 5, wherein:

the side regions of the absorbent core have high grammage portions having a higher grammage than low grammage portions forming the bottom portions of the side longitudinal grooves.

12. The absorbent article of claim 11, wherein:

in the side regions, the density of the absorbent member is higher in the high grammage portion than in the low grammage portion.

13. The absorbent article of claim 1, wherein:

the central region has a central protruding portion protruding toward the non-skin-side sheet from the lower surface of the side region,

the ratio of the width of the central protruding section to the entire width of the absorbent core is 20% or more and 80% or less.

14. The absorbent article of claim 1, wherein:

the ratio of the thickness of the central region to the thickness of the side regions is 110% to 400%.

15. The absorbent article of claim 9, wherein:

in the central region of the absorbent core, the ratio of the grammage of the low grammage part to the grammage of the high grammage part is 5% or more and 80% or less.

16. The absorbent article of claim 6, wherein:

in a boundary portion between the central region and the side regions, a central lateral groove of the central region and a side lateral groove of the side regions are aligned in position in a longitudinal direction of the absorbent core.

17. The absorbent article of claim 2, wherein:

the bottom of the longitudinal groove in the central region is located below the lower surface of the side region.

18. The absorbent article of claim 2, wherein:

the bottom of the vertical groove in the central region is located at substantially the same position as the lower surface of the side region.

19. The absorbent article of claim 2, wherein:

the bottom of the longitudinal groove in the central region is located above the lower surface of the side region.

20. The absorbent article of claim 4, wherein:

the ratio of the depth of the central transverse groove in the central region to the entire thickness of the absorbent core in the central region is 50% to 95%.

21. The absorbent article of claim 1, wherein:

the ratio of the height of the central protruding portion protruding from the lower surface of the side region at the drain portion facing portion to the entire thickness of the central region is 20% to 90%.

22. The absorbent article of claim 21, wherein:

the ratio of the height of the rear portion protruding from the lower surfaces of the side regions to the entire thickness of the central region is 20% to 90%.

23. The absorbent article of claim 1, wherein:

the absorbent main body, which is a region where the skin-side sheet, the non-skin-side sheet, and the absorbent core overlap in a plan view, of the excretion portion-facing portion has a pair of side wing portions on both left and right sides.

24. The absorbent article of claim 23, wherein:

the absorbent main body in the rear portion has a pair of rear wing portions on both left and right sides thereof.

25. The absorbent article of claim 1, wherein:

the absorbent article is a sanitary napkin.