TW201529055A - Absorptive article - Google Patents

Abstract

An absorptive article is provided with an absorptive core (4) which has a shape long in the front-rear direction of the absorptive article. The absorptive core (4) has arranged in the width direction thereof a center region (41) and side regions (45, 45) located on both sides of the center region (41). The center region (41) has a protrusion (5) protruding further upward than the upper surfaces of the side regions. In the absorptive core (4), the center region (41) and the side regions (45) are formed integrally with each other, and the center region (41) has on both sides thereof high-density sections (41a) having higher density than the protrusion (5) and also having a greater weighed amount than the side regions (45). The skin-contact surface of the protrusion (5) has formed therein a longitudinal groove (50) formed in the longitudinal direction by reducing the weighed amount of a material which forms the absorptive core, the longitudinal groove (50) having a bottom section (50b) on the non-skin-contact surface side thereof. In the longitudinal groove (50), the length of the bottom section (50b) thereof in the width direction is less than length of the opening (50a) thereof in the width direction.

Description

Absorbent article

The invention relates to an absorbent article such as a menstrual sanitary napkin, a sanitary pad (vaginal secretion pad), an incontinence pad and the like.

Conventionally, it has been known that an absorbent body in an absorbent article such as a menstrual napkin is provided with a ridge portion along a concave-convex shape of a wearer's skin, and it is also known that a groove is formed in the ridge portion. For example, Patent Literatures 1 and 2 disclose an absorber having a raised portion having a groove in the vicinity of a central portion of the absorbent body.

Further, Patent Document 3 discloses a technique in which a high-density region is disposed in a region including both side portions of the upper portion of the opposing portion of the excretory portion, thereby improving the diffusion and retention performance of the body fluid.

Prior technical literature Patent literature

Patent Document 1: Japanese Patent Laid-Open Publication No. 2009-112590

Patent Document 2: Japanese Patent Laid-Open Publication No. 2012-125366

Patent Document 3: Japanese Patent Laid-Open No. 2011-120696

The absorbent body of Patent Document 1 has a laminated structure including an upper layer and a lower layer, and a central portion in which an upper layer is formed and a raised portion is formed, and a recess extending through the upper and lower layers is formed. However, the recess is formed by hot embossing, and the vicinity of the bottom of the recess is densified, so that the liquid does not easily diffuse from the vicinity of the bottom of the recess to other portions, in the case of Wetback. There is room for improvement in terms of preventing performance and efficient use of the absorbent capacity of the absorbent body.

Further, Patent Document 2 discloses an absorbent body having a plurality of convex portions having a square shape, and a ridge portion including a plurality of convex portions is provided, and the density of the square absorbing portion of the middle and high portions is higher than the surrounding portion. However, the density of the block absorbing portion of the middle and high portions is improved by compressing the entire absorbing portion of the block, and the density of the absorbing portion of the block becomes uniform, thereby improving the diffusibility of the body fluid from the liquid drain portion to the peripheral portion. There is room for improvement in terms of the anti-wetting prevention performance and the effective utilization of the absorption capacity of the absorbent body.

Further, Patent Document 3 discloses an absorbent body having a high portion disposed in an opposing portion of the excretion portion, and a side portion of the compressed high-absorbent body along the longitudinal direction of the absorbent article to make the absorbent article width direction The density of the central portion is relatively low, and the density of the side portions including at least a portion of the side portions of the middle and high portions is relatively high. However, since there is no longitudinal groove for allowing the liquid to permeate rapidly, the absorption speed of the liquid is slow, and the liquid is quickly infiltrated into the inside of the absorbent body to effectively utilize the absorbent body in terms of providing a dry feeling to the wearer quickly. There is room for improvement in terms of absorption capacity.

The present invention relates to an absorbent article having an absorbent core having a shape that is long in the front and rear direction of the absorbent article. The absorptive core has a central region and a lateral region on both sides thereof in the width direction thereof, and the central region has a protruding portion that protrudes upward from the upper surface of each of the lateral regions. The central portion of the absorbent core system is integrally formed with the lateral region, and has a high-density portion that compresses both side portions in the width direction of the central portion and has a higher density than the protruding portion on the inner side in the width direction. a longitudinal groove is formed in the skin contact surface of the protruding portion, and the longitudinal groove is formed along the longitudinal direction of the absorbent core to reduce the basis weight of the material for forming the absorbent core, and is non-skinned The side has a bottom. The longitudinal groove has a length in the width direction of the bottom portion that is narrower than the opening portion.

1‧‧‧Periodical cotton

2‧‧‧Skin side sheet

2a‧‧‧Front sheet

2b‧‧‧Three-dimensional protective forming sheet

3‧‧‧Non-skin side sheet

4‧‧‧Absorbent core

4'‧‧‧ Deposits

4A‧‧‧Absorbent core

5‧‧‧Protruding

6‧‧‧Absorbable ontology

7‧‧‧Flanking

8‧‧‧ rear wing

11‧‧‧Uplift

21‧‧‧ Side edge

41‧‧‧Central area

41a‧‧‧High Density Department

42‧‧‧High base

42'‧‧‧Parts

42d‧‧‧Parts

Section 42u‧‧‧

43‧‧‧Low basis weight

43'‧‧‧Parts

44‧‧‧ transverse slot

44a‧‧‧ transverse slot

44b‧‧‧ transverse slot

44d‧‧‧ bottom

45‧‧‧Side area

46‧‧‧High base

47‧‧‧Low basis weight

48‧‧‧Low basis weight

49‧‧‧Low basis weight

50‧‧‧ longitudinal slot

50a‧‧‧ openings

50b‧‧‧ bottom

50c‧‧‧ side wall

52‧‧‧ side longitudinal groove

52a‧‧‧ Opening

52b‧‧‧ bottom

54‧‧‧Fiber Stacking Roller

55‧‧‧Concave recess

56‧‧‧ bottom

56a‧‧‧ recess

57‧‧‧Insufficient gas-permeable components

61‧‧‧ Pressing section (compression section)

A‧‧‧ front section

B‧‧‧The Department of Liquid Excretion

C‧‧‧ Rear

La‧‧‧ Length

Lb‧‧‧ length

P1‧‧‧ parts

R‧‧ Direction

S2‧‧‧ surface above the side area

T‧‧‧ Height

T1‧‧‧ thickness

T2‧‧‧ thickness

W‧‧‧Width

W1‧‧‧Width

W2‧‧‧Width

X‧‧‧The length direction of the absorbent core

Y‧‧‧The width direction of the absorbent core

BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1 is a perspective view showing a menstrual sanitary napkin according to an embodiment of the present invention.

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

3(a) to 3(c) are explanatory views showing an example of a method of forming a high-density portion having a higher density than the protruding portion and a higher basis weight than the side portion on both side portions of the central portion.

Fig. 4 is a schematic view showing a state of deformation of the absorbent core in the wearing state of the menstrual napkin of Fig. 1.

5(a) and 5(b) are schematic views showing a cross section in the circumferential direction of the fiber stacking drum which is preferably used in the manufacture of the absorbent core of the menstrual sanitary napkin shown in Fig. 1.

6(a) and 6(b) are explanatory views showing an example of a method of forming a compression portion that is caught in the vertical groove.

An object of the present invention is to provide an absorbent article which can further improve the performance of the prior art described above.

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

The menstrual sanitary napkin 1 (hereinafter also referred to simply as the sanitary napkin 1) which is one embodiment of the absorbent article of the present invention is a sanitary napkin suitable for use at night when sleeping, and preferably has a length of 30 cm or more.

As shown in Fig. 1, the sanitary napkin 1 has an absorbent body 6, a pair of side flap portions 7, 7 and a pair of rear wing portions 8, 8 which are long in the front-rear direction. Regarding absorbent articles such as menstrual napkins, the "front-rear direction" is a direction in which the wearer is in the same direction as before and after wearing. Further, in the present specification, the front-rear direction is the longitudinal direction, and the direction orthogonal thereto is referred to as the width direction.

The absorbent main body 6 has a front portion A, a liquid discharge portion facing portion B, and a rear portion C in the longitudinal direction thereof, and has a pair of side flap portions 7 and 7 on the right and left sides of the liquid discharge portion opposing portion B, and is rearward. The left and right sides of the portion C have a pair of rear wing portions 8, 8. The portion where the central portion of the liquid excretion portion in the width direction of the opposing portion B is opposed to the liquid excretion portion (vaginal opening) of the wearer, and the front portion A is disposed on the front side of the liquid excretion portion facing portion B. (belly In the portion of the side, the rear portion B is disposed on a portion of the back side of the wearer facing portion B of the liquid discharge portion.

The sanitary napkin 1 includes a skin side sheet 2 that forms a skin abutting surface toward the wearer's skin side when worn, and a non-skin side sheet 3 that is formed on a non-skin abutting surface toward the garment side such as a pair of shorts when worn. And an absorbent core 4 disposed between the two sheets 2 and 3. The skin side sheet 2 is provided with a liquid-permeable front sheet 2a and a pair of three-dimensional protective forming sheets 2b and 2b joined to both sides thereof. The liquid-permeable front sheet 2a is disposed in the central portion of the absorbent body 6 in the width direction so as to extend over the entire length of the absorbent body 6. In a state in which the side edge portion 21 on the center side in the width direction of the absorbent body is superposed on the front sheet 2a, the sheet 2b for the three-dimensional protection forming is slightly outward in the width direction from the side edge portion 21, and The front sheet 2a is joined. The three-dimensional protective forming sheet 2b has an elastic member (not shown) for forming a three-dimensional shield in the vicinity of the side edge portion 21, and the liquid excretion portion facing portion B is formed by the contraction force of the elastic member when worn. A portion of the side edge portion 21 having a specific width rises away from the front sheet 2a to form a three-dimensional shield.

The pair of side flap portions 7 and 7 and the pair of rear wing portions 8 and 8 include a sheet for forming a stereoscopic protection sheet 2b and a non-skin side sheet 3 which are extended from both side edges of the absorbent core 4. A side flap adhesive portion (not shown) for fixing the non-skin contact surface of the crotch portion of the shorts to the surface of the pair of side flap portions 7 including the non-skin side sheet 3 is provided on the absorbent body 6 The non-skin contact surface is provided with a body adhesive portion (not shown) for fixing the main body 6 to the inner surface of the shorts. When the rear wing portion 8 is worn, it is placed on the inner surface (skin contact surface) of the shorts. Preferably, the surface of the rear wing portion 8 including the non-skin side sheet 3 is provided with an adhesive portion for fixing to the inner surface of the shorts. The skin side sheet 2 and the non-skin side sheet 3 are joined to each other on the outer side of the peripheral edge portion of the absorbent core 4 by an adhesive, and joined to the peripheral portion of the napkin 1 by heat sealing. It is preferable that the skin-side sheet 2 and the absorbent core 4 are interposed between the absorbent core 4 and the non-skin-side sheet 3 by an adhesive which is applied by patterning such as dots, spirals, and stripes. Engage.

The absorbent core 4 in the sanitary napkin 1 includes a fiber aggregate containing a fibrous material such as pulp fibers or a polymer having a highly water-absorptive polymer between the fibers of the fiber aggregate. The absorbent core 4 is coated on both the upper and lower sides by a core material (not shown) including a toilet paper or a water-permeable nonwoven fabric. The packaged chip material is used to prevent leakage of the formation material of the absorbent core or to improve the shape retention of the absorbent core.

As shown in Fig. 1, the absorbent core 4 in the sanitary napkin 1 has a shape that is long in the same direction as the front and rear directions of the sanitary napkin 1. Further, as shown in Fig. 2 (a) and Fig. 2 (b), the absorbent core 4 has a central portion 41 and lateral regions 45, 45 on both sides thereof in the width direction Y, and the central portion 41 has A protruding portion 5 that protrudes upward from the upper surfaces S2 and S2 of each of the side regions 45 and 45.

In the sanitary napkin 1, the protruding portion 5 of the absorbent core 4 is present under the front sheet 2a, and a raised portion 11 that protrudes toward the wearer's skin side is formed at the center portion in the width direction of the skin contact surface.

Further, the ratio of the width W1 of the protruding portion 5 (see Fig. 2(a)) to the entire width W2 of the absorbent core is preferably 20% or more, more preferably 30% or more, and still more preferably 80% or less. More preferably, it is 70% or less, and further preferably 20% or more and 80% or less, more preferably 30% or more and 70% or less.

As shown in Fig. 1, the protruding portion 5 of the absorbent core 4 in the sanitary napkin 1 and the ridge portion 11 formed thereby have a shape elongated in the longitudinal direction of the absorbent core, and are from the sanitary napkin 1 The liquid discharge portion facing portion B is formed over one portion of the rear portion C. More specifically, it is formed in the range from the vicinity of the front end portion of the liquid discharge portion facing portion B to the vicinity of the central portion of the rear portion C in the X direction.

The protruding portion 5 and the raised portion 11 are preferably formed in the front and rear direction X of the sanitary napkin 1 (absorbent article) from the liquid discharge portion facing portion B to one portion of the rear portion C. Further, the protruding portion 5 and the raised portion 11 are preferably formed over a length of 30% or more of the entire length of the front and rear directions X of the sanitary napkin 1, and more preferably 40% or more of the entire length of the sanitary napkin 1. Further, it is preferably formed over a length of 50% or more of the entire length of the sanitary napkin 1. The same applies to the longitudinal groove 50 and the high density portion 41a described below.

A longitudinal groove 50 is formed in the skin abutting surface of the protruding portion 5 of the absorbent core 4, and the longitudinal groove 50 is along the longitudinal direction X of the absorbent core 4 to reduce the base of the material for forming the absorbent core. It is formed by weight and has a bottom on the non-skin abutting side. In other words, the vertical groove 50 is not formed by compressing one portion of the protruding portion 5 such as embossing, but is formed in a portion of the protruding portion 5 and provided with a portion having a lower basis weight of the material for forming the absorbent core. Further, the vertical groove 50 has an opening 50a on the skin contact surface of the absorbent core 4, and has a bottom portion 50b on the non-skin contact surface side. In the sanitary napkin 1 shown in Fig. 1, the number of the longitudinal grooves 50 provided in the protruding portion 5 is one, but the number of the longitudinal grooves provided in the protruding portion is not limited thereto, and may be intermittently set with respect to the width direction Y. There are multiple articles. In the sanitary napkin 1, the vertical groove 50 is disposed so as to vertically project the protruding portion 5 along the longitudinal direction of the protruding portion 5.

Further, a lateral groove 44a is formed in the protruding portion 5 of the absorbent core 4, and the lateral groove 44a is formed in the same manner as the vertical groove 50, and the basis weight of the material for forming the absorbent core 4 is reduced. The abutting side has a bottom. The lateral groove 44a extends along the width direction Y of the absorbent core 4.

In the sanitary napkin 1 shown in Fig. 1, a plurality of lateral grooves 44a are intermittently provided in the protruding portion 5 with respect to the longitudinal direction X. In the sanitary napkin 1, the lateral groove 44a is provided so as to cross the protruding portion 5 along the width direction of the protruding portion.

As shown in Fig. 2(a), in the central region 41 of the absorbent core 4, a high basis weight portion 42 and a low base forming the bottom portion of the longitudinal groove 50 are alternately formed in the width direction Y of the absorbent core 4. The weight portion 43 and the low basis weight portion 43 extend along the longitudinal direction X of the absorbent core 4. The high basis weight portion 42 is a portion where the basis weight of the material for forming the absorbent core is relatively higher than that of the low basis weight portion 43, and the low basis weight portion 43 is the basis weight and high basis weight of the material for forming the absorbent core. The portion 42 is relatively lower than the basis weight.

In the central region 41 of the absorbent core 4, the ratio of the basis weight of the low basis weight portion 43 forming the bottom of the longitudinal groove 50 to the basis weight of the high basis weight portion 42 is preferably 5% or more, more preferably 10%. The above is preferably 50% or less, more preferably 40% or less, still more preferably 5% or more and 80% or less, and still more preferably 10% or more and 70% or less. Further, the basis weight of the high basis weight portion 42 is preferably 200 g/m ² or more, more preferably 300 g/m ² or more, further preferably 800 g/m ² or less, more preferably 700 g/m ² or less. It is preferably 200 g/m ² or more and 800 g/m ² or less, more preferably 300 g/m ² or more and 700 g/m ² or less. The basis weight of the low basis weight portion 43 is preferably 10 g/m ² or more, more preferably 15 g/m ² or more, further preferably 400 g/m ² or less, more preferably 350 g/m ² or less, and further preferably It is 10 g/m ² or more and 400 g/m ² or less, more preferably 25 g/m ² or more and 300 g/m ² or less.

In the central region 41 of the absorbent core 4, the high basis weight portion 42 has a base weight that is larger than the low basis weight portion 43 forming the bottom of the longitudinal groove 50, and is also thicker than the low basis weight portion 43. The ratio of the thickness of the low basis weight portion 43 to the thickness of the high basis weight portion 42 is preferably 5% or more, more preferably 10% or more, further preferably 50% or less, more preferably 40% or less, and It is preferably 5% or more and 50% or less, more preferably 10% or more and 40% or less. Further, the thickness of the high basis weight portion 42 is preferably 1.5 mm or more, more preferably 2 mm or more, further preferably 10 mm or less, more preferably 8 mm or less, further preferably 1.5 mm or more and 10 mm or less, more preferably 2mm or more and 8mm or less. The thickness of the low basis weight portion 43 is preferably 0.08 mm or more, more preferably 0.15 mm or more, further preferably 5 mm or less, more preferably 4 mm or less, and further preferably 0.08 mm or more and 5 mm or less, more preferably 0.15. Mm or more and 4 mm or less.

In the case where the sanitary napkin 1 of the present embodiment includes the lateral grooves 44a to constitute the absorbent core, the values of the high basis weight portion 42 and the values associated with the low basis weight portion 43 are as long as The high basis weight portion not including the lateral groove 44a may satisfy the above conditions.

[Method for determining the basis weight of high basis weight and low basis weight]

Using a single-edged razor manufactured by FEATHER Co., the absorbent core is cut along the boundary line between the high basis weight portion 42 and the low basis weight portion 43 to obtain a high basis weight portion 42 and a low portion in a predetermined area. A small piece of the basis weight 43. The high base weight 42 will be clamped to a pair of low basis weights Portions of the sections 43, 43 are cut out as small pieces. That is, the high basis weight portion 42 is cut out as a small square piece divided by the low basis weight portion 43. When the small piece is in the case of the low basis weight portion 48 including the bottom portion of the lateral groove 44a extending in the width direction, the boundary line between the high basis weight portion 42 and the low basis weight portion 43 and the low basis weight portion 48 is divided. The high basis weight 42 is cut out as a sample slice and used for measurement. The small piece of the low basis weight portion 43 is cut out as a small piece so that the narrow portion sandwiched between the pair of high basis weight portions 42 and 42 has a length of 30 mm.

The weight of the small pieces was measured using an electronic balance (electronic balance GR-300 manufactured by A & D Co., Ltd., accuracy: 4 digits after the decimal point). The basis weight of the small piece is calculated by dividing the obtained weight by the area of the small piece of the high basis weight portion 42 or the low basis weight portion 43. Regarding each of the high basis weight portion 42 and the low basis weight portion 43, the basis weight of the five small pieces is averaged as the basis weight.

[Method for measuring the thickness of high base weight and low basis weight]

The measurement of the thickness of the high basis weight portion 42 and the low basis weight portion 43 is performed by measuring the thickness of the small piece cut for the basis weight measurement of each portion. The measurement unit of the high basis weight portion 42 and the small base portion of the low basis weight portion 43 cut out from the absorbent article was pressed by a pressure of 5 kPa for 10 minutes, and immediately after the pressure release. In the central region of the sample after pressure release, an acrylic plate having a size of 20 mm × 20 mm and a thickness of 3 mm was placed on the absorber 3, using a non-contact laser displacement meter manufactured by KEYENCE (laser LK-G30, displacement) Calculate the thickness of the sample by counting LK-GD500). When the size of the cut piece is small and it is difficult to measure by a non-contact laser displacement meter, for example, a microscope (VHX-1000 manufactured by KEYENCE Corporation) can be used, at a magnification of 20 to 100 times. The measurement was performed by observing the cross section of the cut sample described above.

In the central region 41 of the absorbent core 4, the high basis weight portion 42 has a higher density of the absorbent member than the low basis weight portion 43 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 4 in the step of manufacturing the absorbent core 4. At this time, the pressure applied by the pressing is concentrated on the thick base portion 42 having a relatively large thickness, and the low basis weight portion 43 having a small thickness is not subjected to pressure by pressing and is not compressed. So designed to borrow The density of the absorbing members of the high basis weight portion 42 with respect to the low basis weight portion 43 is increased by compressing only the high basis weight portion 42. Further, in the central portion 41 of the absorbent core 4, a high basis weight portion 42 and a low basis weight portion 48 forming a bottom portion of the lateral groove 44a are alternately formed in the longitudinal direction X of the absorbent core 4. The high basis weight portion 42 also has a higher density of the absorbing member than the low basis weight portion 48 forming the bottom of the lateral groove 44a. Further, the density can be calculated by using the basis weight and thickness obtained by the above measurement method.

On the other hand, in the side region 45 of the absorbent core 4, the high basis weight portion 46 has a higher density of the absorbing member than the low basis weight portion 47 forming the bottom portion of the side longitudinal groove 52. Such a constitution can be obtained as follows. The lateral region 45 of the absorbent core 4 is pressed in a different step than the step of pressing the central region 41. The pressure applied by pressing is concentrated on the thicker base portion 46 having a thicker thickness, and the lower basis weight portion 47 having a smaller thickness is not subjected to pressure by pressing and is not compressed. As such, it is designed such that the density of the absorbing members of the high basis weight portion 46 with respect to the low basis weight portion 47 becomes high by compressing only the high basis weight portion 46. Further, the pressing step used in this step is performed by using a press roll which is cut into a shape corresponding to the central portion 41 or a portion which is only in a portion corresponding to the side region 45 of the absorbent core 4 A measure such as a roller presses only the lateral region of the absorbent core 4.

Further, by forming the high basis weight portion 42 having the basis weight difference and the density difference and the low basis weight portion 43 in the above-described manner, the skin contact surface of the central portion 41 of the absorbent core 4 is absorbed separately. The vertical groove 50 that is recessed toward the non-skin contact surface side is formed to extend in the width direction Y of the core body 4. In the present specification, the skin contact surface of the absorbent article or the constituent member thereof is a non-skin-resistant surface of the absorbent article or the constituent member of the absorbent article or the constituent member thereof when worn toward the wearer's skin side. The junction is the surface of the absorbent article or its constituent members on the opposite side of the skin side facing the wearer when worn.

Further, as shown in Fig. 2(a), the high basis weight portion 46 and the low basis weight portion 47 are alternately formed in the lateral direction 45 of the absorbent core 4 in the width direction Y of the absorbent core 4. Each of the low basis weight portions 47 extends along the longitudinal direction X of the absorbent core 4. Absorption of high basis weight 46 The basis weight of the forming material of the core body is relatively higher than that of the low basis weight portion 47, and the basis weight of the material forming the absorbent core of the low basis weight portion 47 is relatively larger than that of the high basis weight portion 46. Lower.

Further, by forming the high basis weight portion 46 and the low basis weight portion 47 having the basis weight difference and the density difference in the above-described manner, the skin contact surface of the side region 45 of the absorbent core 4 is also respectively A plurality of side longitudinal grooves 52 that are recessed toward the non-skin contact surface side are formed to extend in the longitudinal direction X of the absorbent core 4.

In the lateral region 45 of the absorbent core 4, the ratio of the basis weight of the low basis weight portion 47 forming the bottom portion of the side longitudinal groove 52 to the basis weight of the high basis weight portion 46 is preferably 5% or more, more preferably It is 10% or more, more preferably 50% or less, more preferably 40% or less, further preferably 5% or more and 50% or less, more preferably 10% or more and 40% or less. Further, the basis weight of the high basis weight portion 46 is preferably 50 g/m ² or more, more preferably 100 g/m ² or more, further preferably 400 g/m ² or less, more preferably 300 g/m ² or less. It is preferably 50 g/m ² or more and 400 g/m ² or less, more preferably 100 g/m ² or more and 300 g/m ² or less. The basis weight of the low basis weight portion 47 is preferably 2.5 g/m ² or more, more preferably 5 g/m ² or more, further preferably 200 g/m ² or less, more preferably 150 g/m ² or less, and further, It is preferably 2.5 g/m ² or more and 200 g/m ² or less, more preferably 5 g/m ² or more and 150 g/m ² or less.

In the lateral region 45 of the absorbent core 4, the high basis weight portion 46 has a base weight that is larger than the low basis weight portion 47 forming the bottom of the side longitudinal groove 52, and is also thicker than the low basis weight portion 47. The ratio of the thickness of the low basis weight portion 47 to the thickness of the high basis weight portion 46 is preferably 5% or more, more preferably 10% or more, further preferably 50% or less, more preferably 40% or less, and It is preferably 5% or more and 50% or less, more preferably 10% or more and 40% or less. Further, the thickness of the high basis weight portion 46 is preferably 0.8 mm or more, more preferably 1 mm or more, further preferably 5 mm or less, more preferably 4 mm or less, further preferably 0.8 mm or more and 5 mm or less, more preferably 1mm or more and 4mm or less. The thickness of the low basis weight portion 47 is preferably 0.04 mm or more, more preferably 0.08 mm or more, further preferably 0.4 mm or less, more preferably 0.32 mm or less, and further preferably 0.04 mm or more and 0.4 mm or less. Good is 0.08mm or more and 0.32mm or less.

In the case where the sanitary napkin 1 of the present embodiment includes the lateral grooves 44b to constitute the absorbent core, the values of the high basis weight portion 46 and the values associated with the low basis weight portion 47 are as long as The high basis weight portion not including the lateral groove 44b may satisfy the above conditions.

Further, the method of measuring the basis weight and the thickness of each of the high basis weight portion 46 and the low basis weight portion 47 is performed in the same manner as the measurement method of the high basis weight portion 42 and the low basis weight portion 43 described above.

Further, the basis weight of the high basis weight portion 42 of the central portion 41 is larger than the high basis weight portion 46 of the side portion 45, and the thickness is also larger than the high basis weight portion 46 of the side portion 45. Therefore, the thickness t1 of the central portion 41 is thicker than the thickness t2 of the side region 45, and the central portion 41 is formed with the protruding portion 5 that protrudes upward from the upper surface S2 of the side region 45.

The ratio of the thickness t1 of the central region 41 to the thickness t2 of the lateral region 45 is preferably 110% or more, more preferably 120% or more, further preferably 400% or less, more preferably 300% or less, and further, Preferably, it is 110% or more and 400% or less, more preferably 120% or more and 300% or less. In the present embodiment, the thickness t1 of the central portion 41 is the thickness of the high basis weight portion 42 located at the central portion in the width direction of the central portion 41, and the thickness t2 of the side portion 45 is a high basis weight portion adjacent to the central portion 41. The above thickness of 46.

In either of the liquid discharge portion facing portion B and the rear portion C, the ratio of the height t of the protruding portion 5 protruding from the upper surface S2 of the side portion 45 to the total thickness t1 of the central portion 41 is preferably 20 More than %, more preferably 30% or more, further preferably 90% or less, more preferably 80% or less, further preferably 20% or more and 90% or less, more preferably 30% or more and 80% or less. The protruding height t of the protruding portion 5 is the same as the value obtained by subtracting the thickness t2 of the side region 45 from the total thickness t1 of the central portion 41.

In the sanitary napkin 1, in the side region 45, a high basis weight portion 46 and a low basis weight portion 49 are alternately formed in the longitudinal direction X of the absorbent core 4, and each of the low basis weight portions 49 is along the absorbent The width direction Y of the core 4 extends. Thereby, a plurality of lateral grooves 44b are intermittently arranged in the lateral direction 45 with respect to the longitudinal direction X. The low basis weight portion 48 of the central region 41 and the low basis weight portion 49 of the side region 45 are at the boundary portion between the central region 41 and the side region 45, and the absorbent core 4 The positions in the longitudinal direction X are identical, and similarly, the lateral grooves 44a of the central portion 41 and the lateral grooves 44b of the lateral regions 45 and 45 are at the boundary portion, and the positions in the longitudinal direction X of the absorbent core 4 coincide.

That is, the lateral groove 44a of the central portion 41 and the lateral groove 44b of the lateral regions 45, 45 form a continuous lateral groove 44 extending from the central region 41 of the absorbent core 4 to the lateral regions 45, 45. The groove 44 extends over the entire width of the absorbent core 4. Further, the lateral grooves 44 are formed in plural at intervals in the longitudinal direction of the absorbent core 4. In other words, the low basis weight portion 43 of the central region 41 and the low basis weight portion 47 of the side region 45 are formed to continuously extend one of the low basis weights throughout the entire width of the absorbent core 4, which is a low basis weight portion The basis weight, thickness and density of the material forming the absorbent core are smaller than the high basis weight 46 of the side region 45.

Regarding the lateral groove 44, the space in the lateral groove from which the upper portion is liberated from the central region to the lateral region is not disconnected from the central region and the lateral region, but is transmitted from the central region to the lateral region. Exist continuously. In the sanitary napkin 1 of the present embodiment, the lateral groove 44 and the vertical groove 50 intersect in a cross shape in plan view, but there is another cross in the extension of the space in the lateral groove on one side of the face-to-face with the longitudinal groove interposed therebetween. In the case of all or part of the space in the tank, the lateral grooves are not broken at the intersection with the longitudinal grooves.

In the sanitary napkin 1 of the present embodiment, the absorbent core 4 is integrally formed with the central region 41 and the side region 45, and has the above-mentioned projections having a density on the inner side in the width direction on both sides in the width direction of the central portion 41. The high-density portion 41a having a high portion 5 and a higher basis weight than the side region 45. In the sanitary napkin 1 of the present embodiment, as shown in Figs. 3(a) to 3(c), the high-density portion 41a is compressed to form a central portion 41 of the absorbent core 4 when the sanitary napkin is manufactured. The portion 42' of the high basis weight portion 42 is formed by forming the same thickness in both sides in the width direction. Further, in the sanitary napkin 1, the longitudinal groove 50 of the protruding portion 5 has a length in the width direction of the bottom portion 50b which is narrower than the opening portion 50a. As shown in Fig. 2(a), the longitudinal groove 50 has a substantially V shape when viewed in a cross section in the width direction. The central region 41 has such a configuration, and the characteristic effects can be exhibited in the present invention as follows.

First, the body fluid is discharged to the protruding portion 5 of the central region 41 at the liquid discharge portion facing portion B. By the longitudinal grooves 50 extending in the longitudinal direction X, the excrement becomes easy to diffuse in the longitudinal direction X. On the other hand, in the width direction Y, the vertical groove 50 has a shape in which the opening portion 50a is wide and the bottom portion 50b is narrow. Therefore, the body liquid entering the vertical groove 50 is in contact with the side wall 50c of the vertical groove 50, and faces the bottom portion 50b. The direction flows. Therefore, the body fluid is absorbed by the side wall 50c before reaching the bottom portion 50b, diffuses in the width direction Y of the protruding portion 5, and penetrates in the thickness direction. In the side portion of the central portion 41, there is a high-density portion 41a in which the protruding portion 5 is compressed. Therefore, the body fluid diffused in the width direction Y and the thickness direction is guided to the high density portion. The basis weight of the absorbent material of the high density portion is higher than that of the side region 45, so the ability to retain body fluid is high. Therefore, the body fluid is intercepted at both side portions of the central portion 41, and it is not easy to reach both sides in the width direction of the sanitary napkin 1. Therefore, in the sanitary napkin 1, it is easy to suppress the side leakage of the body fluid. Further, in the sanitary napkin 1 of the present embodiment, since the high-density portion 41a has substantially the same thickness as the high basis weight portion 46 of the side region 45, it is easy to provide the width of the protruding portion 5 and the wearer. The shape of the excretory portion is suitable for the high absorption area which is not easy to give an uncomfortable feeling. However, the present invention is not limited thereto, and the thickness of the high-density portion 41a may be smaller than the thickness of the protruding portion 5, and may be thicker than the high basis weight portion 46 of the side region 45, or may be thicker from the protruding portion 5 toward the lateral region 45. The high-density portion 41a is inclined so as to be gradually smaller than the height of the high basis weight portion 46 of the side portion 45, whereby the inclined portion from the protruding portion 5 to the side portion 45 is provided to impart a soft appearance Sex.

In the present specification, the "integral molding" is different from the members which are manufactured in different steps by means of bonding means such as an adhesive or compression, and means that the same material is used and integrally formed in one step. Therefore, for example, between the portion 42u of the central portion 41 where the projection 5 is formed and the portion 42d located lower than the portion 42u, there is no occurrence of the case where the two absorbent cores which are separately manufactured are overlapped. The adjacent portion or the joint portion of the layers, and the boundary portion between the central portion 41 and the side regions 45 and 45, are not present in the case where the two absorbent cores to be separately manufactured are arranged and arranged. Body each other Adjacent or joint.

When the central region 41 including the protruding portion 5 is integrally formed with the pair of lateral regions 45, 45, the absorbed liquid has continuity of smooth movement. A method of producing an absorbent core of such a configuration will be described below.

More specifically, the high density portion 41a will be described.

The high-density portion 41a of the sanitary napkin 1 is formed by using a fiber stacking device having a main portion shown in Fig. 5(a), and is formed to have a wall thickness including a portion including the high-density portion 41a as shown in Fig. 3(a). After the absorbent core 4A of the central region 41 is compressed, both sides of the central region 41 of the absorbent core 4A are compressed. In the sanitary napkin 1, the thickness is reduced by compressing a fixed portion of the left and right side portions of the protruding portion 5 of the central portion 51, and this portion is formed as a high density as a region having a higher density than the uncompressed protruding portion 5. Part 41a. Further, since the high-density portion 41a has a higher basis weight than the side region 45 of the absorbent material, it has a sufficient absorption capacity, so that the body fluid can be prevented from reaching the side edge of the absorbent core 4.

Therefore, it is easy to prevent leakage of body fluid from the side of the sanitary napkin 1. In the sanitary napkin 1 of the present embodiment, the thickness of the high-density portion (region) 41a is substantially the same as the portion of the lateral region 45 where the vertical groove 50 and the lateral groove 44 are not present. However, the present invention is not limited thereto, and the high-density portion may be used. The thickness is thinner than the protruding portion 5, but the thickness is thicker than the lateral portion 45.

Further, in the sanitary napkin 1, as shown in Fig. 2(a), the longitudinal groove 50 of the protruding portion 5 gradually narrows in the width direction from the opening portion 50a toward the bottom portion 50b, and the longitudinal groove is observed in the width direction cross section. 50 becomes a substantially V shape. In addition to this form, the shape may be a stepped cross-sectional shape. However, when it is substantially V-shaped, the body fluid can be efficiently contacted with the wall surface of the side wall 50c before the opening 50a of the vertical groove 50 reaches the bottom portion 50b. Since the gap portion is gradually narrowed, the capillary force acts from the opening portion 50a of the vertical groove toward the bottom portion 50b, and the liquid can be absorbed into the inside of the absorbent core 4 more quickly, so that the liquid is easily abutted from the skin of the protruding portion 5. It is preferable that the side is absorbed into the inside of the absorbent core 4.

The length La of the opening portion 50a of the longitudinal groove 50 of the protruding portion 5 in the width direction is preferably 0.5 mm. The above is more preferably 1 mm or more, further preferably 5 mm or less, further preferably 4 mm or less, and the width direction Lb of the bottom portion 50b is preferably 1 mm or less, and more preferably 0.5 mm or less. The lower limit of the width direction length Lb of the bottom portion 50b is 0 (zero).

Further, the depth of the vertical groove 50 is preferably 0.5 mm or more and 5.0 mm or less, and more preferably 1.0 mm or more and 3.0 mm or less. Further, the difference between the length of the opening 50a of the vertical groove 50 and the length of the bottom portion 50b (the above-mentioned La-Lb) is preferably 0.5 mm or more and 3.0 mm or less, and more preferably 1.0 mm or more and 2.0 mm or less.

Further, the ratio of the depth of the vertical groove 50 to the difference in the width direction of the opening portion 50a and the bottom portion 50b (the above-described La-Lb) [depth/difference (La-the above-mentioned Lb)] is preferably 0.5 or more and 20 or less. Further, it is preferably 1 or more and 10 or less. If it is this range, it is easy to stabilize the shape of the longitudinal groove in wearing, and it is easy to maintain the shape preferable for absorbing excrement.

Further, the bottom portion 50b of the vertical groove 50 is located below the upper surface S2 of the side portion 45. Here, the position of the upper surface S2 of the side region 45 is the upper surface of the high basis weight portion 46 of the portion of the side region 45 adjacent to the central portion 41. The bottom portion 50b of the longitudinal groove 50 is preferably in the longitudinal direction X of the absorbent core 4, over the entire area of the central portion 41, and below the upper surface S2 of the lateral portion 45. By forming such a configuration, the liquid can be quickly moved from the surface of the sanitary napkin 1 to the inside of the absorbent core 4, and the liquid is directed from the inside of the absorbent core 4 toward the side edge of the absorbent core 4. diffusion. By temporarily absorbing the liquid from the surface of the sanitary napkin 1 into the interior of the absorbent core 4, the liquid is diffused inside the absorbent core 4, whereby the diffusion of the liquid onto the surface of the sanitary napkin 1 can be suppressed, and the liquid is allowed to be liquid. Spread on the back of the sanitary napkin 1. Therefore, the portion of the surface of the sanitary napkin 1 which is moistened by the liquid can be reduced, the user can be provided with a comfortable dry feeling, and the liquid can be easily transferred to the side region 45 of the absorbent core 4, and the absorbent core can be utilized more efficiently. The absorption capacity of the body 4 provides a product which is less likely to leak even when used for a long period of time. Further, since the diffusion of the liquid on the surface of the sanitary napkin 1 is suppressed, the difference in the diffusibility of the liquid on the surface of the sanitary napkin 1 and the back surface of the sanitary napkin 1 becomes large, and the difference allows the user to visually feel the sanitary napkin 1 The absorption is higher. to In the sanitary napkin 1, the basis weight and the thickness of the low basis weight portion 43 of the central portion 41 are smaller than the high basis weight portion 46 of the side portion 45. Therefore, the longitudinal groove 50 and the lateral groove 44 are respectively spread over the absorbent core 4 The entire length of the central region 41 in the longitudinal direction X and the width direction Y is located below the upper surface S2 of the lateral region 45.

Further, in the sanitary napkin 1 of the present embodiment, the plurality of lateral grooves 44 are in the width direction Y of the absorbent core 4, and the portions P1 and P1 of the central region 41 adjacent to the lateral region 45 are referred to [Fig. 2 (refer to Fig. 2). The bottom portion 44d of b)] is located below the upper surface S2 of the side area 45. As shown in Fig. 2(b), the bottom portion 44d of the lateral groove 44 is preferably in the width direction of the absorbent core 4, over the entire area of the central portion 41, and below the upper surface S2 of the lateral portion 45. In the present sanitary napkin 1, the basis weight and the thickness of the low basis weight portion 43 of the central portion 41 are smaller than the high basis weight portion 46 of the side portion 45. Therefore, the longitudinal groove 50 and the lateral groove 44 extend over the absorbent core 4, respectively. The entire length of the central region 41 in the longitudinal direction X and the width direction Y is located below the upper surface S2 of the lateral region 45.

Whether the bottoms of the longitudinal grooves 50 and the lateral grooves 44 are located lower than the upper surface S2 of the lateral portion 45 is determined by measuring the portion 43 forming the bottom portion 50b of the longitudinal groove 50 or forming the central portion 41 adjacent to the lateral portion 45. The thickness of the portion of the bottom portions 44d of the portions P1, P1 and the thickness of the high basis weight portion 46 of the side regions 45 are determined. Specifically, first, the absorbent core 4 is taken out from the sanitary napkin 1, and the thickness of the high basis weight portion 46 of the side region 45 is measured based on the bottom surface of the central portion 41. The thickness was measured by pressing the respective parts at a pressure of 5 kPa for 10 minutes. After the pressure release, an acrylic plate having a size of 20 mm × 20 mm and a thickness of 3 mm was placed in the measurement site, and a non-contact laser displacement meter manufactured by KEYENCE Corporation was used. The shot LK-G30, displacement meter LK-GD500) was carried out. Next, using a single-edged razor manufactured by FEATHER Co., the measuring portion at the bottom of the portions P1 and P1 adjacent to the side region 45 of the central region 41 was cut out from the absorbent article, and pressurized at a pressure of 5 kPa for 10 minutes to release the pressure. The thickness was measured immediately afterwards. An acrylic plate having a size of 20 mm × 20 mm and a thickness of 3 mm was placed on the absorbent body 3 in the central portion of the sample after the pressure release, using KEYENCE A non-contact laser displacement meter (laser head LK-G30, displacement meter LK-GD500) was fabricated to determine the thickness of the sample. When the size of the cut piece is small and it is difficult to measure by a non-contact laser displacement meter, for example, a microscope (VHX-1000 manufactured by KEYENCE Corporation) can be used, at a magnification of 20 to 100 times. The measurement was performed by observing the cross section of the cut sample described above. If the thickness of the measurement portion at the bottom of the portions P1 and P1 adjacent to the side region 45 of the central region 41 is larger than the thickness of the high basis weight portion 46 of the lateral region 45 obtained previously, it is determined that the longitudinal groove 50 and the lateral groove are The bottom of 44 is located below the surface S2 above the side area 45.

Further, in either of the central region 41 and the lateral region 45, the absorbent core 4 is present by the lateral grooves and the longitudinal grooves, and the skin abutting surface has a concave-convex shape, and on the other hand, the non-skin abutting surface The sides are flat.

According to the sanitary napkin 1 of the present embodiment, the central portion 41 having the protruding portion 5 is formed with a lateral groove 44 having a deeper depth, and the bottom portion 44d reaches a position deeper than the upper surface S2 of the lateral portion 45, and The central portion 41 extends to the side portion 45, and the lateral groove 44 is formed by reducing the basis weight of the material for forming the absorbent core. Therefore, in general, although it has a protruding portion 5 which is easy to hinder the bending, it is also deformable. The skin abutment surface is also less prone to wrinkles. Therefore, as shown in FIG. 4, the protruding portion 5 and the ridge portion 11 formed thereby can be deformed along the body of the wearer along the liquid discharge portion or the gluteal groove of the wearer. It is excellent in the conformability with respect to the unevenness of the body, and is excellent in followability with respect to the movement of the wearer, and it is also difficult to impart discomfort due to wrinkles or bending of the absorbent core.

This effect is further improved if the bottom portion 44d of the lateral groove 44 extends over the entire central portion 41 of the absorbent core 4 in the width direction Y and is located below the upper surface S2 of the lateral portion 45.

Further, since the absorbent core system is integrally formed, the lateral grooves 44 are formed by reducing the basis weight of the material for forming the absorbent core, and therefore the liquid absorbed from the protruding portion 5 is thick in the central portion 41. The liquid diffuses smoothly in the direction of the liquid, and the liquid easily diffuses from the vicinity of the bottom of the lateral groove 44 to other portions, and the liquid remaining in the vicinity of the bottom of the lateral groove 44 is not returned to the skin abutting surface by the pressurization. Therefore, even when a large amount of liquid is supplied, the liquid does not easily remain on the skin contact surface, and a comfortable wearing feeling can be obtained.

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

Further, the width W of the lateral groove 44 is preferably 0.2 mm or more, more preferably 0.5 mm or more, further preferably 3 mm or less, more preferably 2 mm or less, and further preferably 0.2 mm or more and 3 mm or less. It is 0.5 mm or more and 2 mm or less. As shown in Fig. 1, the width W of the lateral groove 44 is the dimension in the longitudinal direction X of the absorbent core.

Further, in the sanitary napkin 1, since the density of the high basis weight portion 42 of the central portion 41 is low and the basis weight portion 43 is high, the body fluid absorbed into the lateral groove 44 is quickly absorbed into the high basis weight portion 42. Therefore, since the body fluid flows along the lateral grooves 44 and is absorbed in the longitudinal direction of the absorbent core 4, the body fluid absorption in the central region can be efficiently performed. As a result, the inhibition of leakage of the liquid from the absorbent core 4 is enhanced. Further, in the side region 45, the density of the high basis weight portion 46 is also lower than that of the base portion 47, so that the same effect can be obtained.

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

Further, in the sanitary napkin 1, a plurality of compression portions that are compressed from the front sheet 2a side toward the absorbent core 4 so as to be integrated are provided in the center portion 41. Further, in a portion where the compression portion overlaps with the vertical groove 50 of the central portion 41, the front sheet 2a is caught in the vertical groove 50. Therefore, it is difficult to cause the bulging of the front sheet 2a during wearing, and wrinkles are less likely to occur. Further, the body fluid easily enters the absorbent core 4 from the compression portion, and it is easy to prevent the body fluid from flowing on the front sheet 2a and causing side leakage or the like. This effect is particularly effective in the case of highly viscous body fluids such as menstrual blood. For example, as shown in Fig. 6 (a) and Fig. 6 (b), the compressed portion is formed by overlapping the front sheet 2a on the skin contact surface side of the absorbent core 4, and pressing the front sheet from the side of the front sheet 2a. 2a and the absorbent core 4 are formed. The pressing is performed, for example, by pressing the convex portion 6 for embossing provided on the circumferential surface of the roller and pressing the portion indicated by reference numeral 61 in Fig. 6(a).

Further, in the sanitary napkin 1, the side longitudinal grooves 52 extending in the longitudinal direction are also provided in the side region 45. The side longitudinal groove 52 has substantially the same length in the width direction of the opening portion 52a on the skin contact surface side and the bottom portion 52b on the non-skin side surface side. Here, "substantially the same" means that the difference in the width direction between the opening portion and the bottom portion at the same position in the longitudinal direction is within 5%. With such a configuration, the sanitary napkin 1 is uniformly transmitted in the lateral longitudinal groove 52 by the compressive force received from the user's leg during wearing, and the lateral longitudinal groove 52 is uniformly compressed, thereby relaxing the user's self-contained cotton. The reaction of the compressive force that is subjected to 1 eliminates the discomfort felt by the user in wearing the sanitary napkin 1. Further, when the opening portion 52a of the side vertical groove 52 is formed to be wider than the bottom portion 52b, the opening portion of the sanitary napkin 1 is more greatly deformed due to the compressive force received from the leg portion of the user during wearing. The side edge portion of the sanitary napkin 1 is deformed in such a manner as to be rolled up toward the user. The deformation is such that the side edge of the sanitary napkin 1 is warped toward the skin side of the user, so that the sanitary napkin 1 strongly collides with the groin portion, or in the central portion of the sanitary napkin 1, the skin of the user and the surface of the sanitary napkin 1 Produce separation. However, by making the lengths of the opening portion 52a and the bottom portion 52b substantially the same in the width direction, the risk of such a problem can be reduced. Moreover, it also contributes to the stability of the shape of the longitudinal grooves 50 of the central portion 41 of the present invention.

The side longitudinal grooves 52 are preferably adjacent to the high density portion. With such a configuration, the hardness of the absorbent core 4 that is in contact with the side of the side longitudinal groove 52 and the absorbent core 4 that is in contact with the center side of the side longitudinal groove 52 are different. The difference is that the sanitary napkin 1 is easy to be bent with the side longitudinal groove 52 as a base axis, so that the side edge portion is bent in a direction opposite to the skin of the user, so that the wearing portion is worn. The shape of the sanitary napkin 1 is more stable, whereby the user feels uncomfortable by wearing the sanitary napkin 1, and the central portion of the sanitary napkin 1 can be more closely adhered to the skin of the user, thereby absorbing the liquid more efficiently. Further, by arranging the high-density portion for attracting and capturing the liquid adjacent to the side longitudinal groove 52 having a relatively low density, it is possible to prevent the liquid from oozing sideways toward the higher density portion and to fix the liquid to the liquid. The area near the central portion of the sanitary napkin 1 prevents liquid from leaking from the side edges of the sanitary napkin 1.

Preferably, the bottom portion 50b of the longitudinal groove 50 of the central portion 41 is located on the bottom surface of the lateral side longitudinal groove 52 (the upper surface of the bottom portion 52b) on the non-skin abutting surface side. With this configuration, first, the side portion of the sanitary napkin 1 is bent in the direction opposite to the skin of the user with the bottom surface of the longitudinal groove 50 on the side closer to the non-skin contact surface, and the side of the sanitary napkin 1 The square portion has a side surface located on the side longitudinal groove 52 on the side closer to the skin contact surface, and is bent in a direction opposite to the skin of the user, so that the shape of the sanitary napkin 1 in use can be more stabilized.

The absorbent core 4 of the sanitary napkin 1 can be produced by processing the absorbent core 4A after performing the processing shown in Figs. 3(a) to 3(c) by using a fiber stacking device. The stacking device includes a fiber stacking drum 54 that includes a collecting recess 55 on the outer peripheral surface and that rotates in the one-way R, and a duct (not shown) that supplies the outer peripheral surface of the fiber stacking drum 54 in a scattered state. The material forming the core.

The collecting recesses 55 are formed in plural at a fixed interval in the circumferential direction of the outer peripheral surface of the fiber stacking drum 54. The bottom surface 56 of the collecting recess 55 includes a mesh plate or the like and has a plurality of fine holes that function as suction holes.

As shown in Fig. 5(a), a recess 56a for forming the central portion 41 having the projection 5 is formed in a portion of the bottom surface 56 of the accumulation recess 55. At the bottom of the collecting recess 55, a gas-impermeable member 57 for forming a low basis weight such as a low basis weight portion 43, 43 is disposed. The gas-impermeable member 57 is fixed so as to protrude from the bottom surface of the collecting recess 55, and may be a non-breathable member, for example, containing metal or plastic.

As with the known fiber stacking device with a fiber stacking drum, one side The suction is applied to the bottom surface of the concave portion 55, and the material for forming the absorbent core is supplied to the inside of the conduit. As shown in Fig. 5(b), the material for forming the absorbent core is deposited into a specific shape in the collecting recess 55. . The absorbent core 4A can be obtained by releasing the deposit 4' from the collecting recess 55. The absorbent core 4A may be appropriately compressed by being pressurized by a pair of rolls or the like before or after being coated with the core material. As shown in Fig. 5(b), the portion 43' including the core forming material deposited on the gas-impermeable member 57 is a low basis weight portion 43 or the like, and is deposited on the bottom portion of the bottom surface of the gas-impermeable member 57. 'Become a high base weight 42 and so on. Further, as described above, by pressing the central portion 41 of the absorbent core 4A, the base portion 41 is formed with a high basis weight portion 42 having a lower density than the base portion 41, which is different from the portion which becomes the central portion 41. The ground portion 45 is pressed, and the side portion 45 is formed with a high basis weight portion 46 having a lower density base portion 47. Further, pressing (compression) of forming the high-density portion 41a in the central portion 41 of the absorbent core 4A may be performed before or after being coated with the core material. The pressing (compression) of forming the high-density portion 41a can be performed simultaneously with the pressing of the central portion 41 at the same time as the pressing of the central portion 41, or simultaneously with the pressing of the side portion 45. Further, it is also possible to carry out the pressing of the central portion 41 and the pressing of the side regions 45 simultaneously by designing the step formed on the circumferential surface of the roller to an appropriate size. Further, it may be carried out in a different step from the pressing of the central portion 41 and the pressing of the side regions 45, or before the pressing of the central portion 41, between the pressing of the central portion 41 and the pressing of the lateral region 45, and the side. After the pressing of the square region 45, it is carried out in a different step than the pressing.

In the case of producing an absorbent core containing a water-absorptive polymer, it is preferred to provide an introduction portion of the water-absorbent polymer in the middle of the conduit.

As the front sheet 2a and the non-skin side sheet 3, the same as the front sheet and the non-skin side sheet which have been used in the prior art can be used without particular limitation. For example, as the front sheet 2a, a non-woven fabric having a liquid permeability or a perforated film can be used. As the non-skin side sheet 3, a liquid impervious film made of synthetic resin or a spunbond-meltblown can be used. - Water-resistant non-woven fabric with high water pressure resistance such as spunbonded non-woven fabric. Further, as the sheet for forming the three-dimensional protective sheet 2b, a water-repellent non-woven fabric having a high water pressure resistance, for example, a spunbond-meltblown-spunbonded nonwoven fabric or the like can be used.

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

For example, the continuous lateral groove 44 extending from the central region 41 to the lateral region 45 may be formed only in the liquid discharge portion facing portion of the absorbent article, or may be formed only in the rear portion.

Further, the absorbent core may contain only a fibrous material such as pulp fibers, or may contain both a fibrous material and a superabsorbent polymer. As the fibrous material, various materials of the absorbent body previously used for an absorbent article such as a sanitary napkin, a sanitary pad, or a disposable diaper can be used without particular limitation, and for example, pulp fiber, rayon fiber, cotton fiber can be used. Short fibers such as cellulose fibers or short fibers of synthetic fibers such as polyethylene. These fibers may be used alone or in combination of two or more. Further, the fiber material is preferably a whole or a part of pulp fibers, and the ratio of the pulp fibers in the fiber material is preferably from 50 to 100% by mass, more preferably from 80 to 100% by mass, even more preferably from 100% by mass. Further, in the absorbent core, in addition to the superabsorbent polymer, a deodorant or an antibacterial agent may be formulated as needed.

Further, in the above embodiment, the high basis weight has a lower density and a higher basis weight, but the density of the two may be the same by omitting the pressing step of the absorbent core.

Further, the front sheet 2a may be recessed in the lateral groove 40a formed in the central portion 41 by the pressing portion 61 (compression portion), and the front sheet 2a may be formed in the lateral groove 44a of the central portion 41 at the pressing portion, or Instead of causing the front sheet 2a to be caught in the vertical groove 50 formed in the central portion 41 by the pressing portion 61 (compression portion), the front sheet 2a is caught in the lateral groove 44a formed in the central portion 41 at the pressing portion.

Moreover, the absorbent article of the present invention may be a sanitary pad (vaginal secretion pad), an incontinence pad, a disposable diaper, or the like, in addition to the menstrual period. The description of the above-described one embodiment and the requirements of only one embodiment are suitable. When applied to other embodiments, the requirements of the respective embodiments may be mutually replaced as appropriate.

In the above embodiment, the present invention further discloses the following absorbent article.

<1> An absorbent article comprising an absorbent core having a shape elongated in a front-rear direction in an absorbent article, wherein the absorbent core has a central region in a width direction thereof and a lateral region on both sides thereof The central region has a protruding portion that protrudes upward from an upper surface of each of the lateral regions, and the central portion of the absorbent core system is integrally formed with the lateral region, and is formed at both sides in the width direction of the central region. a high-density portion having a density higher than that of the protruding portion and having a higher basis weight than the lateral portion, and a longitudinal groove formed in the skin contact surface of the protruding portion, the longitudinal groove being along the longitudinal direction of the absorbent core The base material of the material for forming the absorbent core is reduced, and has a bottom portion on the non-skin contact surface side, and the longitudinal groove has a length in the width direction of the bottom portion that is narrower than the opening portion.

<2> The absorbent article according to the above <1>, wherein the length of the longitudinal groove in the width direction is gradually narrowed from the opening toward the bottom.

The absorbent article according to the above <1>, wherein the protruding portion is formed with a lateral groove extending in the width direction of the absorbent core.

<4> The absorbent article according to the above <3>, wherein the lateral grooves are intermittently arranged in plural with respect to the longitudinal direction (synonymous with the longitudinal direction of the absorbent core).

The absorbent article according to any one of the above aspects, wherein the longitudinal groove longitudinally cuts the protruding portion in the longitudinal direction.

The absorbent article according to any one of the above aspects, wherein the liquid permeable front sheet is disposed on the skin contact surface side of the absorbent core, and the front sheet is disposed. A pressing portion that is integrally pressed with the absorbent core is provided in the central region, and the front sheet is caught in the vertical groove or the lateral groove in the pressing portion.

The absorbent article of any one of the above-mentioned <1> to <6> wherein a side longitudinal groove extending in the longitudinal direction of the absorbent core is disposed on the skin contact surface side of the side region of the absorbent core, and the lateral longitudinal groove is substantially the length of the opening portion and the bottom portion in the width direction. the same.

The absorbent article according to any one of the above aspects, wherein the skin contact surface of the side region of the absorbent core is disposed in the longitudinal direction of the absorbent core. a lateral longitudinal groove extending, and the high density portion is in contact with the lateral longitudinal groove.

The absorbent article according to any one of the above aspects, wherein the bottom portion of the longitudinal groove of the central region adjacent to the lateral region is located above the upper surface of the lateral region. Below.

The absorbent article according to any one of the above aspects, wherein the bottom portion of the longitudinal groove of the portion of the central region adjacent to the lateral region is located closer to the bottom surface of the lateral longitudinal groove. Below.

The absorbent article according to any one of the above aspects, wherein the lateral groove has a bottom on the non-skin abutting surface side, and the bottom portion is located on the upper surface than the lateral side surface. Abut the side of the face.

The absorbent article according to any one of the above aspects, wherein the ratio of the width of the protruding portion to the entire width of the absorbent core is 20% or more and 80% or less.

The absorbent article according to any one of the above aspects, wherein the protruding portion is formed over a length of 30% or more of the entire length of the absorbent article in the front-rear direction.

<14> The absorbent article according to any one of the above-mentioned <1> to <13> wherein, in the central region of the absorbent core, the high basis weight portion has a higher density of the absorbent member than the low basis weight portion.

<15> The absorbent article according to any one of <1> to <14> above, wherein In the central region, the ratio of the basis weight of the low basis weight portion forming the bottom portion of the vertical groove to the basis weight of the high basis weight portion is 5% or more and 80% or less.

<16> The absorbent article according to the above <15>, wherein the ratio of the thickness of the low basis weight portion to the thickness of the high basis weight portion in the central region is 5% or more and 50% or less.

The absorbent article according to any one of the above aspects, wherein the ratio of the thickness of the central region to the thickness of the lateral region is 110% or more and 400% or less.

The absorbent article of any one of the above-mentioned <3>, wherein the lateral groove of the central region and the lateral groove of the lateral region form a central region from the absorbent core to the lateral region. One continuous horizontal groove extends the entire width of the absorbent core.

The absorbent article according to any one of the above aspects, wherein the side region has a gap between the longitudinal groove and the front sheet.

The absorbent article according to any one of the above aspects, wherein the front sheet is caught in the lateral groove in the pressing portion in the central portion.

The absorbent article according to any one of the above aspects, wherein the length of the opening of the vertical groove of the protruding portion in the width direction is preferably 0.5 mm or more, and more preferably 1 mm or more. Further, it is preferably 5 mm or less, and more preferably 4 mm or less.

The absorbent article according to any one of the above aspects, wherein the length Lb of the bottom of the vertical groove of the protruding portion is preferably 1 mm or less, more preferably 0.5 mm or less. And the lower limit is 0 (zero).

The absorbent article according to any one of the above aspects, wherein the depth of the longitudinal groove of the protruding portion is 0.5 mm or more and 5.0 mm or less, and more preferably 1.0 mm or more and 3.0 mm. the following.

<24> The absorbent article according to any one of the above <1> to <23> wherein The difference between the length of the opening of the vertical groove and the width of the bottom portion in the central region (La-Lb) is 0.5 mm or more and 3.0 mm or less, and more preferably 1.0 mm or more and 2.0 mm or less.

The absorbent article according to any one of the above aspects, wherein the depth of the longitudinal groove of the central region is different from the width direction of the opening portion and the bottom portion (the above-mentioned La-Lb) The ratio [depth/difference (La-the above-mentioned Lb)] is 0.5 or more and 20 or less, and more preferably 1 or more and 10 or less.

The absorbent article according to any one of the above-mentioned items, wherein the absorbent article is a menstrual sanitary napkin.

[Industrial availability]

The absorbent article of the present invention has high body fluid absorption performance and can effectively suppress side leakage of body fluid.

1‧‧‧Periodical cotton

2b‧‧‧Three-dimensional protective forming sheet

3‧‧‧Non-skin side sheet

5‧‧‧Protruding

21‧‧‧ Side edge

41‧‧‧Central area

41a‧‧‧High Density Department

42‧‧‧High base

42d‧‧‧Parts

Section 42u‧‧‧

43‧‧‧Low basis weight

44‧‧‧ transverse slot

44a‧‧‧ transverse slot

44b‧‧‧ transverse slot

44d‧‧‧ bottom

45‧‧‧Side area

46‧‧‧High base

47‧‧‧Low basis weight

48‧‧‧Low basis weight

49‧‧‧Low basis weight

50‧‧‧ longitudinal slot

50a‧‧‧ openings

50b‧‧‧ bottom

50c‧‧‧ side wall

52‧‧‧ side longitudinal groove

52a‧‧‧ Opening

52b‧‧‧ bottom

La‧‧‧ Length

Lb‧‧‧ length

P1‧‧‧ parts

S2‧‧‧ surface above the side area

T‧‧‧ Height

T1‧‧‧ thickness

T2‧‧‧ thickness

W1‧‧‧Width

W2‧‧‧Width

Y‧‧‧The width direction of the absorbent core

Claims (26)

An absorbent article comprising an absorbent core having a shape that is long in a front-rear direction of the absorbent article, and wherein the absorbent core has a central region in a width direction thereof and a lateral region on both sides thereof, the center The region has a protruding portion that protrudes upward from the upper surface of each of the lateral regions, and the central portion of the absorbent core system is integrally formed with the lateral region, and has a density at both sides in the width direction of the central region. The high-density portion having a high protruding portion and a higher basis weight than the lateral region, and a longitudinal groove formed in the skin contact surface of the protruding portion, the longitudinal groove is reduced in absorption along the longitudinal direction of the absorbent core The base material is formed by the basis weight of the material, and has a bottom portion on the non-skin contact surface side, and the longitudinal groove has a length in the width direction of the bottom portion that is narrower than the opening portion. The absorbent article of claim 1, wherein the lengthwise direction of the longitudinal groove is gradually narrowed from the opening toward the bottom. The absorbent article according to claim 1, wherein the protruding portion is formed with a lateral groove extending in a width direction of the absorbent core. The absorbent article according to claim 3, wherein the lateral grooves are intermittently arranged in plural with respect to the longitudinal direction of the absorbent core. The absorbent article of claim 1, wherein the longitudinal groove longitudinally cuts the protruding portion in a longitudinal direction of the absorbent core. The absorbent article according to claim 1, wherein a liquid-permeable front sheet is disposed on a skin contact surface side of the absorbent core, and the front sheet and the absorbent core are integrally pressed. The pressing portion is provided in the central region, and the front sheet is caught in the vertical groove at the pressing portion. The absorbent article according to claim 1, wherein a side longitudinal groove extending in a longitudinal direction of the absorbent core is disposed on a skin contact surface side of a side region of the absorbent core, and the side is laterally The opening of the vertical groove is substantially the same length as the width of the bottom. The absorbent article according to claim 1, wherein a side longitudinal groove extending in a longitudinal direction of the absorbent core is disposed on a skin contact surface side of the side region of the absorbent core, and the height is high. The density portion is in contact with the side longitudinal groove. The absorbent article of claim 1, wherein the bottom of the longitudinal groove is located below the upper surface of the lateral region. The absorbent article according to claim 1, wherein a lateral longitudinal groove extending in a longitudinal direction of the absorbent core is disposed on a skin contact surface side of the lateral region of the absorbent core, and the longitudinal direction is The bottom of the groove is located below the bottom surface of the side longitudinal groove. The absorbent article of claim 3, wherein the lateral groove has a bottom on a non-skin abutting surface side, and the bottom portion is located on a non-skin abutting surface side of the upper surface of the lateral region. The absorbent article according to claim 1, wherein the ratio of the width of the protruding portion to the entire width of the absorbent core is 20% or more and 80% or less. The absorbent article according to claim 1, wherein the protruding portion is formed over a length of 30% or more of the entire length of the absorbent article in the front-rear direction. The absorbent article of claim 1, wherein in the central region, a high basis weight portion and a low basis weight portion forming a bottom portion of the longitudinal groove are alternately formed in a width direction of the absorbent core, and the high base is The weight of the absorbing member is higher with respect to the above-mentioned low basis weight. An absorbent article according to claim 1, wherein in said central region, said absorbent a high basis weight portion and a low basis weight portion forming a bottom portion of the vertical groove are alternately formed in a width direction of the core body, and a ratio of a basis weight of the low basis weight portion to a basis weight of the high basis weight portion is 5 More than %, less than 80%. The absorbent article according to claim 15, wherein the ratio of the thickness of the low basis weight portion to the thickness of the high basis weight portion in the central region is 5% or more and 50% or less. The absorbent article according to claim 1, wherein a ratio of a thickness of the central region to a thickness of the lateral region is 110% or more and 400% or less. The absorbent article of claim 3, wherein the lateral groove of the central region and the lateral groove of the lateral region form a continuous transverse groove extending from a central region of the absorbent core to a lateral region, and the transverse groove is continuous Extending the entire width of the absorbent core. The absorbent article according to claim 1, wherein a liquid-permeable front sheet is disposed on a skin contact surface side of the absorbent core, and between the longitudinal groove and the front sheet in the lateral region. There is a gap. The absorbent article according to claim 3, wherein a liquid-permeable front sheet is disposed on a skin contact surface side of the absorbent core, and the front sheet and the absorbent core are integrally pressed. The pressing portion is provided in the central region, and in the central region, the front sheet is caught in the lateral groove at the pressing portion. The absorbent article according to claim 1, wherein the length direction La of the opening of the vertical groove of the protruding portion is 0.5 mm or more and 5 mm or less. The absorbent article according to claim 1, wherein the length Lb in the width direction of the bottom of the vertical groove of the protruding portion is 1 mm or less, and the lower limit is 0. The absorbent article according to claim 1, wherein the depth of the longitudinal groove of the protruding portion is 0.5 mm or more and 5.0 mm or less. The absorbent article according to claim 1, wherein the difference between the length of the opening of the vertical groove and the length of the bottom portion in the central region (the above-mentioned La-Lb) is 0.5 mm or more and 3.0 mm or less. The absorbent article according to claim 1, wherein the ratio of the depth of the longitudinal groove of the central region to the difference in the width direction of the opening portion and the bottom portion (the above-described La-Lb) is [depth/difference (La-Lb above) )] is 0.5 or more and 20 or less. The absorbent article of claim 1, wherein the absorbent article is a menstrual napkin.