TWI660718B - Absorbent article - Google Patents

Abstract

The invention relates to an absorbent article, which comprises an absorbent core (4) having a long shape in the front-back direction of the absorbent article, and the absorbent core (4) has a central region (41) in the width direction thereof. And the lateral areas (45, 45) on both sides thereof, and the central area (41) has protrusions (5) protruding upward from the upper surface of each of the lateral areas. The absorptive core (4) is formed integrally with the central region (41) and the lateral region (45), and is provided on both sides of the central region (41) with a higher density than the protruding portion (5) and a basis weight of the lateral region. The region (45) has a high-density portion (41a). A longitudinal groove (50) is formed on the skin abutment surface of the protrusion (5), and the longitudinal groove (50) is formed along the length direction to reduce the basis weight of the material forming the absorbent core, and is applied to non-skin The abutting surface side has a bottom portion (50b), and the longitudinal groove (50) is a widthwise length of the bottom portion (50b) that is narrower than the opening portion (50a).

Description

Absorbent article

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

Previously, it has been known that an absorbent body in an absorbent article such as menstrual tampons is provided with a raised portion along the uneven shape of the wearer's skin, and it is also known that a groove is formed in the raised portion. For example, Patent Documents 1 and 2 disclose an absorbent body including a raised portion having a groove in the vicinity of a central portion of the absorbent body.

In addition, Patent Document 3 discloses a technique in which a high-density region is arranged in a region including both sides of a middle portion of a high portion of the excretory portion facing portion, thereby improving the diffusion and retention performance of body fluids.

Prior art literature Patent literature

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

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

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

The absorber in Patent Document 1 has a laminated structure including an upper layer and a lower layer, and a recess is formed throughout the upper and lower layers in a central region where an upper layer is present and a raised portion is formed. However, the recess is formed by hot embossing, and the vicinity of the bottom of the recess is densified. Therefore, the liquid is not easily diffused from the vicinity of the bottom of the recess to other parts. There is room for improvement in terms of prevention performance and effective utilization of the absorption capacity of the absorber.

Further, Patent Document 2 discloses that an absorber having a plurality of block-shaped convex portions is provided with a raised portion that also includes a plurality of convex portions, so that the density of the block-absorptive portions in the middle and high portions is higher than the surroundings. However, the density of the block absorption portion in the middle and high portions is increased by compressing the entire block absorption portion, and the density of the block absorption portion becomes uniform, so the diffusion of body fluid from the liquid excretion portion to the surrounding portion is improved. There is room for improvement in terms of the anti-humidity prevention performance and the effective use of the absorption capacity of the absorber.

In addition, Patent Document 3 discloses an absorbent body provided at the mid-high portion of the excretory portion facing portion, and compressing both sides of the mid-high absorbent body along the length direction of the absorbent article to make the absorbent article widthwise. The density of the central portion is relatively low, and the density of the lateral portion including at least a part of the side portion of the middle-high portion is relatively high. However, because there is no vertical groove through which the liquid can pass quickly, the absorption rate of the liquid is relatively slow. In terms of quickly providing the wearer with a dry feeling, the liquid can quickly penetrate the inside of the absorbent body and effectively use the absorbent body. In terms of absorption capacity, there is room for improvement.

The present invention relates to an absorbent article provided with an absorbent core having a long shape in the front-back direction of the absorbent article. The absorptive core has a central region and lateral regions on both sides of the absorbent core in a width direction, and the central region has a protruding portion protruding upward from an upper surface of each of the lateral regions. In the absorptive core system, the central region and the lateral region are integrally formed, and have a high-density portion that compresses both sides in the width direction of the central region and has a higher density than the protrusions located on the inner side in the width direction. A vertical groove is formed on the skin abutting surface of the protruding portion, and the vertical groove is formed along the length direction of the absorbent core to reduce the basis weight of the material forming the absorbent core, and is abutted on the non-skin The face side has a bottom. The length of the vertical groove in the width direction of the bottom portion is narrower than that of the opening portion.

1‧‧‧Menstruation

2‧‧‧Skin Side Sheet

2a‧‧‧Front sheet

2b‧‧‧Three-dimensional protection forming sheet

3‧‧‧ Non-Skin Side Sheet

4‧‧‧ Absorbent core

4'‧‧‧ Accumulation

4A‧‧‧ Absorbent core

5‧‧‧ protrusion

6‧‧‧ Absorptive body

7‧‧‧flank

8‧‧‧ rear wing

11‧‧‧ bulge

21‧‧‧Side edge

41‧‧‧ central area

41a‧‧‧High density department

42‧‧‧High Basis Weight Division

42'‧‧‧part

42d‧‧‧part

42u‧‧‧part

43‧‧‧low basis weight

43'‧‧‧part

44‧‧‧ horizontal groove

44a‧‧‧ horizontal groove

44b‧‧‧ horizontal groove

44d‧‧‧ bottom

45‧‧‧side area

46‧‧‧High Basis Weight

47‧‧‧low basis weight

48‧‧‧low basis weight

49‧‧‧low basis weight

50‧‧‧ longitudinal groove

50a‧‧‧ opening

50b‧‧‧ bottom

50c‧‧‧ sidewall

52‧‧‧Side vertical groove

52a‧‧‧ opening

52b‧‧‧ bottom

54‧‧‧Fiber stacking drum

55‧‧‧Agglomeration recess

56‧‧‧ underside

56a‧‧‧ recess

57‧‧‧breathable member

61‧‧‧Pressing section (compression section)

A‧‧‧Front

B‧‧‧Liquid excretion section facing section

C‧‧‧Rear

La‧‧‧ length

Lb‧‧‧ length

P1‧‧‧part

R‧‧‧ direction

S2‧‧‧ The upper surface of the side area

t‧‧‧ height

t1‧‧‧thickness

t2‧‧‧thickness

W‧‧‧Width

W1‧‧‧Width

W2‧‧‧Width

X‧‧‧ Lengthwise direction of absorbent core

Y‧‧‧Width direction of absorbent core

FIG. 1 is a perspective view showing a menstrual tampon according to an embodiment of the present invention.

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

3 (a) to 3 (c) are explanatory diagrams of 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 lateral area on both sides of the central area.

FIG. 4 is a schematic diagram showing a deformed state 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 along the circumferential direction of a fiber stacking drum preferably used in the manufacture of the absorbent core of the sanitary napkin shown in FIG.

FIG. 6 (a) and FIG. 6 (b) are explanatory diagrams showing an example of a method for forming a compression portion that is trapped in a vertical groove.

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

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

As an embodiment of the absorbent article of the present invention, the menstrual tampon 1 (hereinafter, also simply referred to as the tampon 1) is a night tampon suitable for use at bedtime, preferably a length of 30 cm or more.

As shown in FIG. 1, the sanitary napkin 1 has an absorbent body 6 having a long shape in the front-rear direction, a pair of side wing portions 7, 7, and a pair of rear wing portions 8, 8. Regarding absorbent articles such as menstrual tampons, the so-called "front-rear direction" refers to a direction in which the wearer and the wearer's front-rear direction coincide with each other. In addition, in this specification, the front-back direction is a length direction, and the direction orthogonal to it is called a width direction.

The absorptive body 6 has a front portion A, a liquid draining portion facing portion B, and a rear portion C in its longitudinal direction, and a pair of side flap portions 7 and 7 on the left and right sides of the liquid draining portion facing portion B. The left and right sides of the portion C have a pair of rear wing portions 8, 8. The liquid excretion portion facing portion B is the portion where the central portion in the width direction and the wearer's liquid excretion portion (vaginal opening) face each other. The front portion A is disposed closer to the wearer's front side than the liquid excretion portion facing portion B. (belly Side), the rear portion B is a portion located closer to the wearer's back side than the liquid excretion portion facing portion B.

The sanitary napkin 1 includes: a skin-side sheet 2 that forms a skin abutment surface facing the wearer's skin side when worn; a non-skin-side sheet 3 that forms a non-skin abutment surface facing a clothing side such as shorts when worn And an absorbent core 4, which is arranged between the two sheets 2, 3. The skin-side sheet 2 includes a liquid-permeable front sheet 2a and a pair of three-dimensional protection forming sheets 2b and 2b joined to one of the two sides. The liquid-permeable front sheet 2 a is arranged at the central portion in the width direction of the absorbent body 6 so as to cover the entire length of the absorbent body 6. The sheet 3b for forming three-dimensional protection is superimposed on the front sheet 2a with the side edge portion 21 on the center side in the width direction of the absorbent body at a position slightly out of the width direction from the side edge portion 21, and The front sheet 2a is joined. The sheet 3b for forming a three-dimensional protection is provided with an elastic member (not shown) for forming a three-dimensional protection in the vicinity of the side edge portion 21, and when worn, the contraction force of the elastic member causes the liquid excretion portion facing portion B to A portion having a specific width from the side edge portion 21 stands up away from the front sheet 2a to form a three-dimensional protection.

The pair of side wing portions 7 and 7 and the pair of rear wing portions 8 and 8 include a three-dimensional protection-forming sheet 2b and a non-skin-side sheet 3 that extend from both edges of the self-absorbent core 4. On the side including the non-skin side sheet 3 of each of the pair of side flap portions 7, a side skin adhesive portion (not shown) for fixing to the non-skin contact surface of the crotch portion of the shorts is provided, and the absorbent body 6 A non-skin contact surface is provided with a main body adhesive portion (not shown) for fixing the main body 6 to the inner surface of the shorts. When worn, the rear wing portion 8 is placed on the inner surface (skin contact surface) of the shorts. It is preferable that an adhesive portion for fixing the inner surface of the shorts to the rear wing portion 8 including the non-skin-side sheet 3 is also provided. The skin-side sheet 2 and the non-skin-side sheet 3 are bonded to each other by an adhesive more on the outer side than the peripheral edge portion of the absorbent core 4, and are bonded to the peripheral edge portion of the sanitary napkin 1 by heat sealing. It is preferable that the skin side sheet 2 and the absorptive core 4 and the absorptive core 4 and the non-skin side sheet 3 are also mutually adhered by an adhesive for pattern coating such as dots, spirals, and stripes. Join.

The absorbent core 4 in the sanitary napkin 1 includes a fiber aggregate containing a fibrous material such as pulp fibers or a fiber having a superabsorbent polymer held between the fibers of the fiber aggregate. The absorptive core 4 is covered with upper and lower surfaces with a core material (not shown) including a toilet paper or a water-permeable nonwoven fabric. The core material is used to prevent leakage of the material forming 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 long shape in the same direction as the front and back directions of the sanitary napkin 1. As shown in FIGS. 2 (a) and 2 (b), the absorbent core 4 has a central region 41 and lateral regions 45 and 45 on both sides in the width direction Y. The central region 41 has A protruding portion 5 that protrudes upward from the upper surfaces S2 and S2 of each of the lateral regions 45 and 45.

The sanitary napkin 1 has a raised portion 11 protruding toward the skin side of the wearer at the central portion in the width direction of the skin abutting surface due to the protruding portion 5 of the absorbent core 4 under the front sheet 2a.

The ratio of the width W2 of the protruding portion 5 [see FIG. 2 (a)] to the entire width W1 of the absorbent core is preferably 20% or more, more preferably 30% or more, and still more preferably 80% or less. It is more preferably 70% or less, more preferably 20% or more and 80% or less, and even 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 raised portion 11 formed thereby have a shape that is longer in the length direction of the absorbent core, and is formed from the sanitary napkin 1. The liquid excretion portion facing portion B is formed over a portion of the rear portion C. More specifically, it is formed in a range from the vicinity of the front end portion of the liquid discharge portion facing portion B to the vicinity of the X-direction center portion of the rear portion C.

The protruding portion 5 and the raised portion 11 are preferably formed in a direction X from front to back of the sanitary napkin 1 (absorbent article) from the liquid excretion portion facing portion B to a portion of the rear portion C. The protruding portion 5 and the raised portion 11 are preferably formed over a length of more than 30% of the total length of the tampon 1 in the front-rear direction X, and more preferably formed over a length of more than 40% of the total length of the tampon 1. It is more preferable to form it over 50% of the total length of the sanitary napkin 1. The same applies to the vertical grooves 50 and the high-density portions 41 a described below.

A longitudinal groove 50 is formed on the skin abutment surface of the protruding portion 5 of the absorbent core 4, and the longitudinal groove 50 is along the length direction X of the absorbent core 4 to reduce the base of the material forming the absorbent core 4 It is heavy and has a bottom on the non-skin contact surface side. That is, the vertical groove 50 is not formed by compressing a part of the protruding portion 5 by embossing or the like, but is formed by arranging a portion of the protruding portion 5 with a portion having a low basis weight of the material for forming the absorbent core. Moreover, the vertical groove 50 has an opening part 50a on the skin contact surface of the absorbent core 4, and has a bottom part 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 to this, and it may be provided intermittently with respect to the width direction Y. There are multiple. In the sanitary napkin 1, the vertical grooves 50 are arranged so as to vertically cut the protruding portions 5 along the longitudinal direction of the protruding portions 5.

In addition, a horizontal groove 44a is formed in the protruding portion 5 of the absorbent core 4, and the horizontal groove 44a is formed by reducing the basis weight of the material forming the absorbent core 4 in the same manner as the vertical groove 50, and is applied to non-skin The contact surface side has a bottom. The lateral groove 44 a extends in the width direction Y of the absorbent core 4.

In the sanitary napkin 1 shown in FIG. 1, a plurality of lateral grooves 44 a are intermittently provided in the protruding portion 5 with respect to the longitudinal direction X. In the sanitary napkin 1, the horizontal 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 of the vertical groove 50 are alternately formed in the width direction Y of the absorbent core 4. The heavy 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 relatively higher basis weight of the material forming the absorbent core than the low basis weight portion 43, and the low basis weight portion 43 is the basis weight and the high basis weight of the forming material of the absorbent core. The portion 42 has a relatively low 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 to the basis weight of the high basis weight portion 42 forming the bottom of the vertical groove 50 is preferably 5% or more, and more preferably 10%. The above is more preferably 50% or less, more preferably 40% or less, still more preferably 5% or more and 80% or less, and even more preferably 10% or more and 70% or less. The basis weight of the high basis weight portion 42 is preferably 200 g / m ² or more, more preferably 300 g / m ² or more, still more preferably 800 g / m ² or less, and even more preferably 700 g / m ² or less. It is preferably 200 g / m ² or more and 800 g / m ² or less, and more preferably 300 g / m ² or more and 700 g / m ² or less. The basis weight of the low basis weight portion 43 is preferably 10 g / m ² or more, more preferably 15 g / m ² or more, more preferably 400 g / m ² or less, still more preferably 350 g / m ² or less, and more preferably It is 10 g / m ² or more and 400 g / m ² or less, and 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 is not only larger than the low basis weight portion 43 forming the bottom of the vertical groove 50, but also has a thickness greater 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, more preferably 50% or less, even more preferably 40% or less, and, It is preferably 5% or more and 50% or less, and more preferably 10% or more and 40% or less. The thickness of the high basis weight portion 42 is preferably 1.5 mm or more, more preferably 2 mm or more, more preferably 10 mm or less, more preferably 8 mm or less, and still more preferably 1.5 mm or more and 10 mm or less, and more preferably 2mm to 8mm. The thickness of the low basis weight portion 43 is preferably 0.08 mm or more, more preferably 0.15 mm or more, more preferably 5 mm or less, more preferably 4 mm or less, and still more preferably 0.08 mm or more and 5 mm or less, and more preferably 0.15. mm to 4mm.

When the absorbent core is formed by including the lateral groove 44a like the sanitary napkin 1 of this embodiment, the values of the above-mentioned high basis weight portion 42 and the values having a relationship with the low basis weight portion 43 only need to be The high basis weight portion that does not include the lateral groove 44a may meet the above conditions.

[Method for measuring basis weight of high basis weight portion and low basis weight portion]

Using a single-edged razor manufactured by FEATHER, the absorptive 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 area in a predetermined area. A small piece of the base weight 43. The high basis weight part 42 is sandwiched between a pair of low basis weights Parts 43 and 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 includes the low basis weight portion 48 forming the bottom of the horizontal groove 44a extending in the width direction, the small piece is divided by a boundary line between the high basis weight portion 42 and the low basis weight portion 43 and the low basis weight portion 48. The high basis weight portion 42 is cut out as a sample slice and used for measurement. The small pieces of the low basis weight portion 43 are cut out as small pieces with a narrow portion sandwiched between the pair of high basis weight portions 42 and 42 so that the length becomes 30 mm.

An electronic balance (electronic balance GR-300 manufactured by A & D company, accuracy: 4 digits after the decimal point) was used to determine the weight of these small pieces. The calculated weight is calculated by dividing the obtained weight by the area of the small pieces in 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 average of the basis weights of the five small pieces was taken as the basis weight.

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

The measurement of the thickness of the high basis weight part 42 and the low basis weight part 43 is performed by measuring the thickness of the small piece cut out for the basis weight measurement of each part. The measurement portion of the small pieces of the high basis weight portion 42 and the low basis weight portion 43 cut out of the self-absorbent article was pressurized with a pressure of 5 kPa for 10 minutes, and the measurement was performed immediately after the pressure was released. In the central area of the sample after pressure release, an acrylic plate with a size of 20 mm × 20 mm and a thickness of 3 mm was placed on the absorber 3, and a non-contact laser displacement meter (laser head LK-G30, displacement) manufactured by KEYENCE was used. LK-GD500), measure the thickness of the sample. When the size of the cut piece is small and it is difficult to measure it with a non-contact laser displacement meter, for example, a microscope (VHX-1000 manufactured by KEYENCE) can be used at a magnification of 20 to 100 times. Observe the cross section of the cut sample and perform the measurement.

In the central region 41 of the absorbent core 4, the high basis weight portion 42 has a higher density than the low basis weight portion 43 forming the bottom of the vertical groove 50. Such a structure 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 pressing is concentrated on the thick high-weight portion 42 and the thin low-weight portion 43 is not subjected to pressure due to pressing and is not compressed. So designed to borrow By compressing only the high basis weight portion 42, the density of the high basis weight portion 42 relative to the low basis weight portion 43 becomes higher. In the central region 41 of the absorptive core 4, a high basis weight portion 42 and a low basis weight portion 48 forming a bottom portion of the lateral groove 44 a are alternately formed in the longitudinal direction X of the absorptive 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 horizontal groove 44a. The density can be calculated by using a basis weight and a thickness obtained based on the measurement method described above.

On the other hand, in the lateral area 45 of the absorbent core 4, the high basis weight portion 46 has a higher density of the absorbent member than the low basis weight portion 47 forming the bottom of the lateral vertical groove 52. Such a structure can be obtained as follows. The lateral region 45 of the absorbent core 4 is pressed in a step different from the step of pressing the central region 41. The pressure applied by pressing is concentrated on the thick high base weight portion 46, and the thin low base weight portion 47 is not subjected to pressure due to pressing and is not compressed. In this way, it is designed to increase the density of the absorbing member in the high basis weight portion 46 with respect to the low basis weight portion 47 by compressing only the high basis weight portion 46. In addition, the pressing step used in this step is to try to use a pressing roller cut into a shape corresponding to the central area 41 or to have a pressing portion only in a portion corresponding to the lateral area 45 of the absorbent core 4 Rollers, etc., and only the lateral area of the absorbent core 4 is pressed.

In addition, by forming the high basis weight portion 42 and the low basis weight portion 43 having a difference in basis weight and a difference in density in the above state, the skin abutment surfaces of the central region 41 of the absorbent core 4 are respectively absorbed. A longitudinal groove 50 is formed extending in the longitudinal direction X of the core 4 toward the non-skin contact surface side. In this specification, the skin contact surface of the absorbent article or its constituent members refers to the surface of the absorbent article or its constituent members that faces the skin side of the wearer when worn, and the non-skin contact of the absorbent article or its constituent members. The contact surface is the surface of the absorbent article or its constituent member opposite to the wearer's skin side when worn.

As shown in FIG. 2 (a), in the lateral region 45 of the absorbent core 4, high basis weight portions 46 and low basis weight portions 47 are alternately formed 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 at high basis weight 46 The basis weight of the forming material of the flexible core is relatively higher than that of the low basis weight portion 47, and the basis weight of the forming material of the absorbent core of the low basis weight portion 47 is relatively higher than that of the high basis weight portion 46. Lower.

In addition, by forming the high basis weight portion 46 and the low basis weight portion 47 having a difference in basis weight and a difference in density in the above state, the skin abutment surfaces of the lateral regions 45 of the absorbent core 4 are also separately formed. A plurality of lateral vertical grooves 52 recessed toward the non-skin contact surface side are formed in the longitudinal direction X of the absorbent core 4.

In the lateral area 45 of the absorbent core 4, the ratio of the basis weight of the low basis weight portion 47 to the basis weight of the high basis weight portion 46 forming the bottom of the side longitudinal groove 52 is preferably 5% or more, more preferably It is 10% or more, more preferably 50% or less, more preferably 40% or less, still more preferably 5% or more and 50% or less, more preferably 10% or more and 40% or less. The basis weight of the high basis weight portion 46 is preferably 50 g / m ² or more, more preferably 100 g / m ² or more, still more preferably 400 g / m ² or less, and even more preferably 300 g / m ² or less. It is preferably 50 g / m ² or more and 400 g / m ² or less, and more preferably 100 g / m ² or more and 300 g / m ² or less. The basis weight of the low basis weight portion 47 is preferably 2.5 g / m ² or more, more preferably 5 g / m ² or more, more preferably 200 g / m ² or less, and even more preferably 150 g / m ² or less. 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 area 45 of the absorbent core 4, the high basis weight portion 46 is not only larger in base weight than the low basis weight portion 47 forming the bottom of the side longitudinal groove 52, but 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, more preferably 50% or less, even more preferably 40% or less, and, It is preferably 5% or more and 50% or less, and more preferably 10% or more and 40% or less. The thickness of the high basis weight portion 46 is preferably 0.8 mm or more, more preferably 1 mm or more, more preferably 5 mm or less, more preferably 4 mm or less, and still more preferably 0.8 mm or more and 5 mm or less, and more preferably 1mm to 4mm. The thickness of the low basis weight portion 47 is preferably 0.04 mm or more, more preferably 0.08 mm or more, more preferably 0.4 mm or less, more preferably 0.32 mm or less, and still more preferably 0.04 mm or more and 0.4 mm or less, more It is preferably 0.08 mm or more and 0.32 mm or less.

When the absorbent core is formed by including the lateral groove 44b like the sanitary napkin 1 of the present embodiment, the values of the above-mentioned high basis weight portion 46 and the values having a relationship with the low basis weight portion 47 only need to be The high basis weight portion excluding the lateral groove 44b may meet the above conditions.

The method of measuring the basis weight and 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 above-mentioned measurement method of the high basis weight portion 42 and the low basis weight portion 43.

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

The ratio of the thickness t1 of the central region 41 to the thickness t2 of the lateral region 45 is preferably 110% or more, more preferably 120% or more, more preferably 400% or less, more preferably 300% or less, and It is preferably 110% to 400%, more preferably 120% to 300%. In this embodiment, the thickness t1 of the central region 41 is the above-mentioned thickness of the high basis weight portion 42 located in the central portion in the width direction of the central region 41, and the thickness t2 of the lateral area 45 is a high basis weight portion adjacent to the central area 41. The above thickness of 46.

In any one of the liquid-draining portion facing portion B and the rear portion C, the ratio of the height t protruding from the upper surface S2 of the lateral area 45 to the total thickness t1 of the central area 41 is preferably 20 % Or more, more preferably 30% or more, more preferably 90% or less, more preferably 80% or less, still more preferably 20% or more and 90% or less, still 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 lateral area 45 from the total thickness t1 of the central area 41.

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

That is, the lateral groove 44a of the central area 41 and the lateral grooves 44b of the lateral areas 45 and 45 form a continuous lateral groove 44 extending from the central area 41 of the self-absorbent core 4 to the lateral areas 45 and 45. The groove 44 extends over the entire width of the absorbent core 4. A plurality of horizontal grooves 44 are formed at intervals in the longitudinal direction of the absorbent core 4. In other words, the low basis weight portion 48 of the central area 41 and the low basis weight portion 49 of the lateral area 45 form a low basis weight portion that extends continuously throughout the entire width of the absorbent core 4. The basis weight, thickness and density of the material forming the absorbent core are smaller than the high basis weight portion 46 of the lateral region 45.

Regarding the horizontal groove 44, the continuous from the central area to the lateral area means that the space in the lateral groove that is liberated on the upper side does not break between the central area and the lateral area, but extends from the central area to the lateral area. Continuously exists. In the sanitary napkin 1 of the present embodiment, the horizontal groove 44 and the vertical groove 50 cross in a cross shape in a plan view, but there is another horizontal direction in the extension of the space in the horizontal groove on one side of the facing surface across the vertical groove. In the case of all or part of the space in the groove, the horizontal groove does not break at the intersection with the vertical groove.

In the sanitary napkin 1 of this embodiment, the absorbent core 4 is formed integrally with the central region 41 and the lateral regions 45, and the two sides of the central region 41 in the width direction have the above-mentioned protrusions with a higher density than the inner side in the width direction. The high-density portion 41 a having a high portion 5 and a higher basis weight than the lateral area 45. In the sanitary napkin 1 of this embodiment, as shown in FIG. 3 (a) to FIG. 3 (c), the high-density portion 41a is compressed during the manufacture of the sanitary napkin to become the central region 41 of the absorbent core 4. The portions 42 ′ of the high basis weight portion 42 are formed on both sides in the width direction and have the same thickness. Moreover, in the sanitary napkin 1, the width direction length of the vertical groove 50 of the protruding part 5 is the bottom part 50b, and is narrower than the opening part 50a. As shown in FIG. 2 (a), the vertical groove 50 has a substantially V shape when viewed in a widthwise cross-section. By having such a configuration due to the central region 41, a characteristic effect can be exhibited in the present invention described below.

First, the body fluid is discharged from the liquid excretion portion facing portion B toward the protruding portion 5 of the central region 41. Due to the longitudinal grooves 50 extending in the longitudinal direction X, excrement becomes easy to spread in the longitudinal direction X. On the other hand, the longitudinal groove 50 has a shape in which the opening portion 50a is wider and the bottom portion 50b is narrower in the width direction Y. Therefore, the body fluid entering the longitudinal groove 50 is in contact with the side wall 50c of the longitudinal groove 50 and faces the bottom 50b. Direction flow. 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. On the side of the central region 41, there is a high-density portion 41a formed by compressing the protruding portion 5. 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 in the high-density portion is higher than that in the lateral region 45, so the ability to retain body fluid is high. Therefore, bodily fluids are intercepted on both sides of the central region 41 and it is difficult to reach the both sides in the width direction of the sanitary napkin 1. Therefore, in the sanitary napkin 1, it is easy to suppress side leakage of body fluids. Furthermore, in the sanitary napkin 1 of the present embodiment, the high-density portion 41a has a thickness substantially the same as that of the high-basis weight portion 46 of the lateral region 45, and therefore it is easy to provide both the width of the protruding portion 5 and the thickness of the wearer. A highly absorbing region with a suitable shape for the excretory portion and a difficulty in imparting discomfort. However, it is not limited to this, and the thickness of the high-density portion 41a may be made smaller than the thickness of the protruding portion 5 and thicker than the high-basis weight portion 46 of the lateral area 45, or the thickness from the protruding portion 5 to the lateral area 45. It is gradually made smaller so that the high-density portion 41a is inclined in the same manner as the height of the high basis weight portion 46 of the lateral area 45, thereby providing a slanted area from the protruding portion 5 to the lateral area 45 to impart softness to the appearance Sex.

In this specification, the so-called "integral molding" is different from the members manufactured in different steps by joining means such as adhesive or compression, but means that the same material is used to form them in one step. Therefore, for example, between the portion 42u where the protrusion 5 is formed in the central region 41 and the portion 42d located below the portion 42u, it does not occur when the two absorbent cores manufactured separately are overlapped. The adjacent part or joint part of the layers and the boundary part between the central area 41 and the lateral areas 45 and 45 also do not exist in the case where two absorbent cores manufactured separately are arranged and arranged. Body each other Abutment or joint.

If the central region 41 including the protruding portion 5 and the pair of lateral regions 45 and 45 are integrally formed, the absorbed liquid has a continuity that can move smoothly. The manufacturing method of the absorbent core of this structure is demonstrated below.

The high-density portion 41a will be described more specifically.

The high-density portion 41a of the sanitary napkin 1 is formed into a wall thickness by using a fiber stacking device having a main portion shown in FIG. 5 (a) as shown in FIG. 3 (a). After the absorbent core 4A of the central region 41 is formed, 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 the fixed portions on the left and right sides of the protruding portion 5 of the central area 41, and this portion is formed as a region having a higher density than the uncompressed protruding portion 5 to form a high density.部 41a。 41a. In addition, the high-density portion 41a has a higher absorptive capacity because the basis weight of the absorptive material is higher than that of the lateral region 45, so that the body fluid can be prevented from reaching the side edges of the absorptive core 4.

Therefore, it is easy to prevent body fluids from leaking from the side of the sanitary napkin 1. In the sanitary napkin 1 of this embodiment, the thickness of the high-density portion (area) 41a is substantially the same as the portion of the lateral area 45 where the vertical groove 52 and the horizontal groove 44 do not exist, but it is not limited to this. The thickness is thinner than the protruding portion 5, but the thickness is thicker than the lateral region 45.

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 as it goes from the opening portion 50a to the bottom portion 50b. 50 has a substantially V shape. In addition to this configuration, it may have a stepped cross-sectional shape. However, when the shape is substantially V-shaped, body fluid can efficiently contact the wall surface of the side wall 50c before reaching the bottom 50b from the opening 50a of the longitudinal groove 50, and because The gap gradually narrows, so the capillary force acts from the opening portion 50a of the longitudinal groove toward the bottom portion 50b, and the liquid can be absorbed into the inside of the absorbent core 4 more quickly. Therefore, the liquid is easy to contact the skin abutment surface of the protruding portion 5. It is preferable that the side absorbs into the inside of the absorbent core 4.

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

The depth of the vertical groove 50 is preferably 0.5 mm to 5.0 mm, and more preferably 1.0 mm to 3.0 mm. The difference in width direction length between the opening portion 50a and the bottom portion 50b of the vertical groove 50 (the La-the 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.

The ratio of the depth of the vertical groove 50 to the difference in the width direction length of the opening portion 50a and the bottom portion 50b (the La-the Lb) [depth / difference (the La-the Lb)] is preferably 0.5 or more and 20 or less. It is more preferably 1 or more and 10 or less. If it is this range, it will be easy to stabilize the shape of the vertical groove in wearing, and it will be easy to maintain the shape which is favorable for absorbing excrement.

The bottom 50b of the vertical groove 50 is located below the upper surface S2 of the lateral region 45. The position of the upper surface S2 of the lateral region 45 here is the upper surface of the high basis weight portion 46 of the lateral region 45 adjacent to the central region 41. The bottom 50 b of the vertical groove 50 is preferably located in the length direction X of the absorbent core 4 over the entire area of the central region 41 and located below the upper surface S2 of the lateral region 45. With such a structure, the liquid can be quickly moved from the surface of the sanitary napkin 1 to the deep inside of the absorbent core 4, and the liquid can be directed from the inside of the absorbent core 4 to the side edge of the absorbent core 4. diffusion. After temporarily absorbing the liquid from the surface of the sanitary napkin 1 to the inside of the absorbent core 4 in this manner, the liquid is diffused inside the absorbent core 4, thereby suppressing the diffusion of the liquid on the surface of the sanitary napkin 1 and making the liquid Spreads on the back of sanitary napkin 1. Therefore, the portion of the surface of the sanitary napkin 1 that is wet by the liquid can be reduced to provide a comfortable and dry feeling to the user, and the liquid can be easily transferred to the lateral area 45 of the absorbent core 4, and the absorbent core can be used more efficiently. The absorption capacity of the body 4 makes it possible to provide a product which is not easily leaked even after long-term use. In addition, since the diffusion of the liquid on the surface of the sanitary napkin 1 is suppressed, the difference between the diffusivity of the liquid on the surface of the sanitary napkin 1 and the back of the sanitary napkin 1 becomes larger. Due to this difference, the user can also feel the sanitary napkin 1 visually. Its absorption is higher. to In the sanitary napkin 1, the base weight and thickness of the low basis weight portion 43 in the central area 41 are smaller than those of the high basis weight portion 46 in the lateral area 45. Therefore, the vertical grooves 50 and the horizontal grooves 44 extend through the absorbent core 4 respectively. In the entire area of the central area 41 in the length direction X and the width direction Y, the bottom is located below the upper surface S2 of the lateral area 45.

Moreover, in the sanitary napkin 1 of the present embodiment, the plurality of lateral grooves 44 are located 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 regions 45 [see FIG. 2 ( b)] The bottom 44d is located below the upper surface S2 of the lateral region 45. As shown in FIG. 2 (b), the bottom 44 d of the horizontal groove 44 is preferably located in the width direction of the absorbent core 4 over the entire area of the central region 41 and is located below the upper surface S2 of the lateral region 45. In this tampon 1, the base weight and thickness of the low basis weight portion 43 of the central area 41 are smaller than the high basis weight portion 46 of the lateral area 45. Therefore, the longitudinal grooves 50 and the transverse grooves 44 extend through the absorbent core 4 respectively. In the entire area of the central area 41 in the length direction X and the width direction Y, the bottom is located below the upper surface S2 of the lateral area 45.

Whether the bottoms of the vertical grooves 50 and the horizontal grooves 44 are located below the upper surface S2 of the lateral area 45 is determined by measuring the portion 43 forming the bottom 50b of the vertical groove 50 or the central area 41 adjacent to the lateral area 45 The thickness of the portion P1 and the bottom portion 44d of the portion P1 and the thickness of the high basis weight portion 46 of the lateral area 45 are determined. Specifically, first, the absorbent core 4 is taken out from the sanitary napkin 1, and the bottom surface of the central region 41 is used as a base point, and the thickness of the high basis weight portion 46 of the lateral region 45 is measured. The thickness was measured by pressing each part with a pressure of 5 kPa for 10 minutes. After releasing the pressure, an acrylic plate with a size of 20 mm × 20 mm and a thickness of 3 mm was placed on the measurement part. A non-contact laser displacement meter (lightning) manufactured by KEYENCE Corporation was used. Head LK-G30, displacement gauge LK-GD500). Next, a single-edged razor manufactured by FEATHER was used to cut out the measurement portion at the bottom of the portions P1 and P1 of the central region 41 adjacent to the lateral region 45 from the absorbent article, pressurizing with a pressure of 5 kPa for 10 minutes, and releasing the pressure The thickness was measured immediately afterwards. In the central area 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 absorbent body 3, and manufactured by KEYENCE Corporation. A non-contact laser displacement meter (laser head LK-G30, displacement meter LK-GD500) was manufactured to measure the thickness of the sample. When the size of the cut piece is small and it is difficult to measure it with a non-contact laser displacement meter, for example, a microscope (VHX-1000 manufactured by KEYENCE) can be used at a magnification of 20 to 100 times. Observe the cross section of the cut sample and perform the measurement. If the thickness of the measurement portion at the bottom of the portion P1, P1 adjacent to the lateral area 45 in the central area 41 is greater than the thickness of the high basis weight portion 46 of the lateral area 45 previously determined, it is judged as a vertical groove 50 and a horizontal groove The bottom of 44 is located below the upper surface S2 of the lateral region 45.

In addition, in any one of the central region 41 and the lateral region 45, the absorptive core 4 has a horizontal groove and a vertical groove, and the skin abutment surface has a concave-convex shape, and the non-skin abutment surface The sides are flat.

According to the sanitary napkin 1 of this embodiment, a horizontal groove 44 is formed in the central area 41 having the protruding portion 5, the horizontal groove 44 is deeper, and the bottom portion 44d reaches a position deeper than the upper surface S2 of the lateral area 45, and Extending from the central region 41 to the lateral region 45, and the horizontal groove 44 is formed by reducing the basis weight of the material forming the absorbent core, it is generally deformable in spite of having the protruding portion 5 which is likely to hinder bending. The skin abutment surface is also less prone to wrinkles. Therefore, as shown in FIG. 4, while the protruding portion 5 and the raised portion 11 formed thereby can follow the wearer's liquid drainage portion or gluteal groove, the overall shape can be deformed along the wearer's body shape, Excellent conformability to unevenness of the body, excellent followability to the wearer's movements, and difficult to impart discomfort caused by wrinkles or bending of the absorbent core.

This effect is further enhanced if the bottom 44d of the lateral groove 44 covers the entire area of the central region 41 in the width direction Y of the absorbent core 4 and is located below the upper surface S2 of the lateral region 45.

In addition, the absorbent core system is integrally formed, and the horizontal groove 44 is formed by reducing the basis weight of the material forming the absorbent core. Therefore, the liquid absorbed from the protruding portion 5 is thicker in the central region 41. It spreads smoothly in the direction of the degree, and the liquid easily diffuses from the vicinity of the bottom of the horizontal groove 44 to other parts, and the liquid retained near the bottom of the horizontal groove 44 does not return to the skin abutment surface due to pressure. Therefore, even in the case where 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 reliably exerting such an effect, the ratio of the depth of the lateral grooves 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 It is preferably 95% or less, more preferably 90% or less, and more preferably 50% or more and 95% or less, and more preferably 60% or more and 90% or less.

The width W of the lateral groove 44 is preferably 0.2 mm or more, more preferably 0.5 mm or more, more preferably 3 mm or less, more preferably 2 mm or less, and still more 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 a dimension in the longitudinal direction X of the absorbent core.

Moreover, in the sanitary napkin 1, since the high basis weight portion 42 in the central region 41 has a lower density than the high basis weight portion 43, the body fluid absorbed into the horizontal groove 44 is quickly absorbed into the high basis weight portion 42. Therefore, the body fluid is absorbed in the longitudinal direction of the absorptive core body 4 while flowing along the horizontal grooves 44, so that the body fluid can be efficiently absorbed in the central region. As a result, the suppression of leakage of the liquid self-absorbent core 4 is improved. In addition, in the lateral area 45, the density of the high basis weight portion 46 is also lower than that of the basis weight portion 47, so the same effect can be obtained.

In each of the central area 41 and the lateral area 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 more preferably 50 % Or less, more preferably 40% or less, more 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 sections are provided in the central region 41 to compress the absorbent core 4 from the front sheet 2a side to form an integrated body. Further, in a portion where the compression portion overlaps the vertical groove 50 of the central region 41, the front sheet 2 a is sunk into the vertical groove 50. Therefore, it is difficult for the front sheet 2a to bulge during wearing, and it is difficult for wrinkles to occur. In addition, the body fluid easily enters into the absorbent core 4 from the compression section, and it is easy to prevent the body fluid from flowing on the front sheet 2a and causing problems such as side leakage. This effect is particularly effective in the case of highly viscous body fluids such as menstrual blood. For example, as shown in Figs. 6 (a) and 6 (b), the compression portion is formed by superimposing the front sheet 2a on the skin contact surface side of the absorbent core 4, and pressing the front sheet from the front sheet 2a side. 2a and the absorptive core 4 are formed. The pressing is performed, for example, by pressing the convex portion 60 for embossing provided on the peripheral surface of the roller, and pressing the portion indicated by reference numeral 61 in FIG. 6 (a).

Further, in the sanitary napkin 1, a lateral vertical groove 52 extending in the longitudinal direction is also provided in the lateral area 45. The lateral vertical grooves 52 have 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 width direction length between the openings at the same position and the bottom is within 5% in the length direction. With this structure, the compression force that the sanitary napkin 1 receives from the user's legs during wearing is uniformly transmitted to the lateral longitudinal grooves 52, and the lateral longitudinal grooves 52 are uniformly compressed. Therefore, the user's self-sanitary napkin can be relaxed. The adverse effect of the compression force experienced by 1 eliminates the discomfort felt by the user when wearing the sanitary napkin 1. Furthermore, if the opening portion 52a of the lateral vertical groove 52 is formed wider than the bottom portion 52b, the opening of the sanitary napkin 1 will be deformed more greatly due to the compressive force received from the user's leg during wearing. The side edge portion of the sanitary napkin 1 may be deformed so as to be rolled toward the user. Such deformation may occur as follows: the side edge portion of the sanitary napkin 1 is warped toward the user's skin side, so the sanitary napkin 1 strongly hits the groin, or at the central portion of the sanitary napkin 1, the user's skin and the surface of the sanitary napkin 1 Generate separation. However, by making the lengths in the width direction of the opening portion 52a and the bottom portion 52b approximately the same, it is possible to reduce the risk of generating such a trouble. Moreover, it also contributes to the stability of the shape of the vertical groove 50 in the central region 41 of the present invention.

The lateral vertical groove 52 is preferably adjacent to the high-density portion. With this configuration, the hardness of the absorptive core 4 in contact with the lateral side of the lateral longitudinal groove 52 and the absorptive core 4 in contact with the center side of the lateral longitudinal groove 52 are different. The difference is that the sanitary napkin 1 is easy to use the lateral longitudinal groove 52 as a base axis, so that the side edge portion is bent in a direction opposite to the user's skin, so that the The shape of the sanitary napkin 1 is more stable, thereby reducing the discomfort felt by the user when wearing the sanitary napkin 1, and making the central portion of the sanitary napkin 1 more tightly contacted with the skin of the user, thereby absorbing liquid more efficiently. In addition, by adjoining the high-density portion that is responsible for attracting and capturing the liquid and the side longitudinal groove 52 having a relatively low density, it is possible to exert an effect of preventing the liquid from oozing to the side of the higher-density portion and fixing the liquid to a more dense portion. The area close to the central area of the sanitary napkin 1 prevents leakage of liquid from the side edges of the sanitary napkin 1.

It is preferable that the bottom 50b of the vertical groove 50 in the central region 41 is located on the non-skin contact surface side of the bottom surface (upper surface of the bottom 52b) of the lateral vertical groove 52. With this configuration, first, the lateral portion of the sanitary napkin 1 is flexed in a direction opposite to the skin of the user, using the longitudinal groove 50 whose bottom surface is located closer to the non-skin contact surface side as the base axis, and secondly, the side of the sanitary napkin 1 The square part uses the lateral longitudinal groove 52 whose bottom surface is located closer to the skin abutting surface side as a base axis, and further bends in a direction opposite to the skin of the user, so that the shape of the sanitary napkin 1 in the wearing can be more stable.

A fiber stacking device can be used for the absorbent core 4 of the sanitary napkin 1. After the absorbent core 4A is manufactured, the fiber is manufactured by performing the processing shown in FIGS. 3 (a) to 3 (c). The stacking device includes a fiber stacking drum 54 provided with a collecting recess 55 on the outer peripheral surface and rotating in a unidirectional direction R; and a duct (not shown) which supplies and absorbs the outer peripheral surface of the fiber stacking drum 54 in a scattered state. Material for forming the core.

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

As shown in FIG. 5 (a), a recessed portion 56 a for forming a central region 41 having a protruding portion 5 is formed on a part of the bottom surface 56 of the recessed portion 55 for accumulation. A gas-permeable member 57 is formed on the bottom of the accumulation recess 55 to form a low basis weight portion such as a low basis weight portion 43 or 43. The air-impermeable member 57 is fixed in such a manner as to protrude from the bottom surface of the recessed portion 55 for agglomeration, and may be a non-air-permeable member, such as metal or plastic.

Similar to a known fiber stacking device including a fiber stacking drum, It sucks from the bottom surface of the agglomeration recess 55, and supplies the forming material of the absorptive core facing the inside of the catheter. As shown in FIG. . By releasing the deposit 4 'from the accumulation recess 55, the absorbent core 4A can be obtained. The absorptive core 4A may be appropriately compressed by being pressurized by passing through a pair of rollers 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 stacked on the air-impermeable member 57 becomes a low basis weight portion 43 and the like, and the portion 42 on the bottom surface of the non-air-permeable member 57 is deposited. 'Become a high basis weight part 42 and the like. As described above, by pressing the central region 41 of the absorbent core 4A, the central region 41 is formed with a high basis weight portion 42 having a low density basis weight portion 43 and a high basis weight portion 42, which is different from the portion forming the central area 41. Ground, by pressing the lateral area 45, a high basis weight portion 46 having a lower density and a higher basis weight portion 47 is formed in the lateral area 45. The pressing (compression) of forming the high-density portion 41a in the central region 41 of the absorptive core 4A may be performed before or after coating with the core material. The pressing (compression) for forming the high-density portion 41a can be performed on a roll having a step on the peripheral surface, and can be performed simultaneously with the pressing of the central region 41 or the pressing of the lateral region 45. In addition, the step formed on the peripheral surface of the roller may be designed to have an appropriate size, and the pressing in the central region 41 and the pressing in the lateral region 45 may be performed simultaneously. Furthermore, it may be performed in a different step from the pressing of the central region 41 and the pressing of the lateral region 45, or before, or between, the pressing of the central region 41 and the pressing of the lateral region 45. After the pressing of the square area 45, it is performed in a step different from these pressings.

When manufacturing an absorbent core containing a water-absorptive polymer, it is preferable to provide an introduction part of a water-absorptive polymer in the middle of a catheter.

As the front sheet 2a and the non-skin-side sheet 3, the same thing as the front sheet and non-skin-side sheet which have been conventionally used in this technical field can be used without a restriction | limiting in particular. 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-impermeable film made of synthetic resin, or spunbond-meltblown can be used. -Water-repellent nonwoven fabrics with high water pressure resistance such as spunbond layer nonwoven fabric. Further, as the sheet 2b for forming three-dimensional protection, a water-repellent nonwoven fabric with high water pressure resistance, such as a spunbond-meltblown-spunbond layer nonwoven fabric, can be used.

As mentioned above, although this invention was demonstrated based on the preferable embodiment of this invention, this invention is not limited to the said embodiment.

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

The absorbent core may contain only fibrous materials such as pulp fibers, or may contain both fibrous materials and superabsorbent polymers. As the fiber material, various materials previously used in absorbent bodies such as menstrual cotton, sanitary pads, or disposable diapers, can be used without particular restrictions. For example, pulp fibers, rayon fibers, and cotton fibers can be used. Short fibers such as cellulose fibers or short fibers such as polyethylene and synthetic fibers. These fibers can be used alone or in combination of two or more. In addition, the fiber material is preferably pulp fibers in whole or in part, and the ratio of pulp fibers in the fiber material is preferably 50 to 100% by mass, more preferably 80 to 100% by mass, and still more preferably 100% by mass. In addition, in addition to the super absorbent polymer, an absorbent core may be prepared with a deodorant, an antibacterial agent, or the like, if necessary.

Further, in the above embodiment, the density of the high basis weight portion is lower than that of the basis weight portion, but the density of the two can be made the same by omitting the pressing step of the absorbent core.

In addition, the front sheet 2a may be inserted into the horizontal groove 44a formed in the central region 41 in the pressing portion in addition to the pressing portion 61 (compressed portion) in the pressing portion 61 (compressed portion), or Instead of sinking the front sheet 2a into the vertical groove 50 formed in the central region 41 in the pressing portion 61 (compressed portion), the front sheet 2a is pushed into the horizontal groove 44a formed in the central region 41 in the pressing portion.

In addition, the absorbent article of the present invention may be other absorbent articles such as sanitary pads (vaginal secretion pads), incontinence pads, disposable diapers, in addition to menstrual pads. The omitted parts of the description in the above one embodiment and the requirements of only one embodiment are applicable respectively. When applied to other embodiments, the elements in each embodiment may be replaced with each other as appropriate.

Regarding the above embodiments, the present invention further discloses the following absorbent articles.

<1> An absorbent article comprising an absorbent core having a longer shape in the front-back direction of the absorbent article, and the absorbent core having a central region in the width direction and lateral regions on both sides thereof The central region has protrusions protruding upward from the upper surface of each of the lateral regions, the central region of the absorptive core system and the lateral region are integrally formed, and both sides of the central region in the width direction, A high-density portion having a higher density than the protruding portion and a higher basis weight than the lateral region, and a longitudinal groove is formed on the skin abutment surface of the protruding portion, and the longitudinal groove is along the length direction of the absorbent core. It is formed by reducing the basis weight of the forming material of the absorbent core, and has a bottom on the non-skin abutting surface side. The width of the longitudinal groove is narrower than the opening in the width direction.

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

<3> The absorbent article according to the above <1> or <2>, wherein a horizontal groove extending in a width direction of the absorbent core is formed in the protruding portion.

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

<5> The absorbent article according to any one of the above <1> to <4>, wherein the vertical groove longitudinally cuts the protruding portion in the vertical direction.

<6> The absorbent article according to any one of <1> to <5>, wherein a liquid-permeable front sheet is disposed on the skin abutment surface side of the absorbent core, and the front sheet A pressing portion integrally pressed with the absorptive core is provided in the central region, and the front sheet is sunk into the vertical groove or the horizontal groove in the pressing portion.

<7> The absorbent article according to any one of <1> to <6> above, wherein A lateral longitudinal groove extending in the longitudinal direction of the absorptive core is arranged on the skin abutting surface side of the lateral region of the absorptive core, and the lateral longitudinal groove is approximately the width of the opening and the bottom in the width direction. the same.

<8> The absorbent article according to any one of the above <1> to <7>, wherein the skin abutment surface on the lateral area of the absorbent core is arranged in the length direction of the absorbent core The extended side longitudinal groove, and the high-density portion is in contact with the side longitudinal groove.

<9> The absorbent article according to any one of the above <1> to <8>, wherein the bottom of the vertical groove in the portion of the central region adjacent to the lateral region is located closer to the upper surface of the lateral region Below.

<10> The absorbent article according to any one of the above <1> to <9>, wherein the bottom of the vertical groove of the central area adjacent to the lateral area is located closer to the bottom surface of the lateral vertical groove Below.

<11> The absorbent article according to any one of <3> to <10>, wherein the horizontal groove has a bottom on the non-skin abutting surface side, and the bottom is located on the non-skin surface than the upper surface of the lateral area Abutment surface side.

<12> The absorbent article according to any one of <1> to <11>, wherein the ratio of the width of the protrusions to the entire width of the absorbent core is 20% or more and 80% or less.

<13> The absorbent article according to any one of the above <1> to <12>, wherein the protruding portion is formed over a length of more than 30% of the total length of the absorbent article in the front-back direction.

<14> The absorbent article according to any one of <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 to the basis weight of the high basis weight portion forming the bottom of the vertical groove 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.

<17> The absorbent article according to any one of <1> to <16>, 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.

<18> The absorbent article according to any one of <3> to <17>, wherein the horizontal grooves in the central region and the lateral grooves in the lateral region form a central region extending from the central region of the absorbent core to the lateral region. One continuous horizontal groove, and the horizontal groove extends over the entire width of the absorbent core.

<19> The absorbent article according to any one of <1> to <18>, wherein a gap exists between the vertical groove and the front sheet in the lateral region.

<20> The absorbent article according to any one of <1> to <19>, wherein in the central region, the front sheet is sunk into the horizontal groove in the pressing portion.

<21> The absorbent article according to any one of the above <1> to <20>, wherein the width direction length La of the opening of the longitudinal groove of the protruding portion is preferably 0.5 mm or more, and more preferably 1 mm or more Also, it is preferably 5 mm or less, and further preferably 4 mm or less.

<22> The absorbent article according to any one of <1> to <21>, wherein the widthwise length Lb of the bottom of the longitudinal groove of the protruding portion is preferably 1 mm or less, and more preferably 0.5 mm or less, And the lower limit is 0 (zero).

<23> The absorbent article according to any one of <1> to <22>, wherein the depth of the longitudinal grooves 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 or less. the following.

<24> The absorbent article according to any one of <1> to <23> above, wherein The difference in width direction length between the opening of the vertical groove and the bottom in the central region (the La-the 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.

<25> The absorbent article according to any one of the above <1> to <24>, wherein the depth of the longitudinal grooves in the central region with respect to the width-wise length of the opening and the bottom (the above-mentioned La-the above-mentioned Lb) The ratio [depth / difference (the above La-the above Lb)] is 0.5 or more and 20 or less, and more preferably 1 or more and 10 or less.

<26> The absorbent article according to any one of <1> to <25>, wherein the absorbent article is a menstrual tampon.

[Industrial availability]

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

Claims (25)

An absorbent article comprising an absorbent core having a long shape in the front-back direction of the absorbent article, and the absorbent core has a central region in the width direction and lateral regions on both sides thereof, the central The region has a protruding portion protruding more upwardly than the upper surface of each of the lateral regions. The central region of the absorbent core system is integrally formed with the lateral region, and has density on both sides in the width direction of the central region. A high-density portion that is higher than the protruding portion and has a higher basis weight than the lateral region. A vertical groove is formed on the skin abutment surface of the protruding portion, and the longitudinal groove is along the length direction of the absorbent core to reduce absorption. The core material is formed by the basis weight of the material and has a bottom on the non-skin contact surface side. The width of the longitudinal groove is narrower than that of the opening, and the width is from the opening to the bottom. Gradually narrows. In the absorbent article according to claim 1, a lateral groove extending in the width direction of the absorbent core is formed in the protruding portion. In the absorbent article according to claim 2, a plurality of the horizontal grooves are intermittently arranged with respect to the longitudinal direction of the absorbent core. The absorbent article according to claim 1, wherein the vertical grooves vertically cut the protruding portions in the longitudinal direction of the absorbent core. For example, the absorbent article according to claim 1, wherein a liquid-permeable front sheet is arranged on the skin abutment 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 sunk into the vertical groove by the pressing portion. For example, in the absorbent article of claim 1, a lateral longitudinal groove extending in the longitudinal direction of the absorbent core is arranged on the skin abutment surface side of the lateral region of the absorbent core, and the lateral side The length of the opening of the vertical groove is substantially the same as the width in the bottom. For example, in the absorbent article according to claim 1, a lateral longitudinal groove extending in the longitudinal direction of the absorbent core is arranged on the skin abutment surface side of the lateral region of the absorbent core, and the height is high. The density portion is in contact with the lateral vertical groove. The absorbent article according to claim 1, wherein the bottom of the vertical groove is located below the upper surface of the lateral area. For example, in the absorbent article according to claim 1, a lateral longitudinal groove extending in the longitudinal direction of the absorbent core is arranged on the skin abutment surface side of the lateral region of the absorbent core, and the vertical The bottom of the groove is located below the bottom surface of the lateral longitudinal groove. The absorbent article according to claim 2, wherein the horizontal groove has a bottom on the non-skin abutting surface side, and the bottom is located on the non-skin abutting surface side than the upper surface of the lateral area. For example, in the absorbent article according to claim 1, the ratio of the width of the protrusions to the entire width of the absorbent core is 20% or more and 80% or less. For example, in the absorbent article according to claim 1, the protrusions are formed over a length of 30% or more of the total length of the absorbent article in the front-back direction. The absorbent article according to claim 1, wherein in the central region, a high basis weight portion and a low basis weight portion forming a bottom of the vertical groove are alternately formed in the width direction of the absorbent core, and the high basis The weight portion has a higher density of the absorbing member than the low basis weight portion. The absorbent article according to claim 1, wherein in the central region, a high basis weight portion and a low basis weight portion forming a bottom of the vertical groove are alternately formed in the width direction of the absorbent core, and the low basis weight The ratio of the basis weight of the heavy portion to the basis weight of the high basis weight portion is 5% or more and 80% or less. For example, in the absorbent article according to claim 14, 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. For example, the absorbent article according to claim 1, 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. For example, the absorbent article of claim 2, wherein the horizontal grooves in the central region and the lateral grooves in the above-mentioned region form a horizontal groove continuous from the central region of the absorbent core to the lateral region, and the transverse groove extends across The entire width of the absorbent core extends. For example, the absorbent article according to claim 1, wherein a liquid-permeable front sheet is disposed on the skin abutment surface side of the absorbent core, and in the lateral region, between the vertical groove and the front sheet There is a gap. For example, the absorbent article according to claim 2, wherein a liquid-permeable front sheet is arranged on the skin abutment surface side of the above-mentioned absorbent core, and the front sheet is integrally pressed with the absorbent core. The pressing portion is provided in the central region, and in the central region, the front sheet is sunk into the horizontal groove in the pressing portion. The absorbent article according to claim 1, wherein the widthwise length La of the opening of the vertical groove of the protruding portion is 0.5 mm or more and 5 mm or less. For example, the absorbent article according to claim 1, wherein the widthwise length Lb of the bottom of the longitudinal groove of the protruding portion is 1 mm or less, and the lower limit is 0. In the absorbent article according to claim 1, wherein the depth of the vertical grooves of the protruding portion is 0.5 mm or more and 5.0 mm or less. For example, the absorbent article according to claim 1, wherein the difference in width direction length between the opening of the longitudinal groove in the central region and the bottom (the La-the Lb) is 0.5 mm or more and 3.0 mm or less. For example, the absorbent article according to claim 1, wherein the ratio of the depth of the longitudinal grooves in the central region to the difference in the width direction length of the opening and the bottom (the above-mentioned La-the above-mentioned Lb) )] Is 0.5 or more and 20 or less. The absorbent article according to claim 1, wherein the absorbent article is a menstrual tampon.