TWI819085B - Pad type absorbent article - Google Patents

Abstract

A pad-type absorbent article according to one aspect of the present invention includes an absorbent core having a front core portion, a rear core portion, and an intermediate core portion located on both end sides in the front-rear direction. The intermediate core part is located between the front core part and the rear core part. The length of the middle core part in the width direction orthogonal to the front-rear direction is shorter than the front core part and the rear core part. The above-mentioned intermediate core part has: a high basis weight part located in the central area in the width direction and having a higher basis weight than the above-mentioned front core part and the above-mentioned rear core part; and a low basis weight part located in both side areas in the width direction. , and has a lower basis weight than the above-mentioned high basis weight part. The high basis weight portion includes: a high basis weight and high thickness portion located at a central portion in the width direction; and a high basis weight and low thickness portion located on both sides of the high basis weight and high thickness portion in the width direction, and having a thickness greater than that of the high basis weight and high thickness portion. Heavy, high and thin.

Description

Pad-type absorbent articles

The present invention relates to pad-type absorbent articles such as menstrual sanitary napkins.

In disposable diapers that require a higher absorption capacity, designs are usually made such that the total amount of absorbent material contained in the absorber is increased. If the total amount of the absorbent material is large, the absorbent body will become hard, so there is a technique for reducing wearing discomfort by forming the lower crotch portion of the wearer into a shape that shrinks along the periphery of the leg (for example, patent documents 1).

In contrast, so-called pad-type absorbent articles, such as menstrual sanitary napkins, which are placed on the inside of underwear and used inside, usually do not require as much absorption capacity as diapers, so the absorbent body is not as hard as diapers, so in most cases A rectangular absorber is used. For example, Patent Document 2 discloses an absorbent core having a shape with equal widths throughout the front and rear directions. In order to prevent side leakage, this absorbent core system has a V-shaped opening on the skin surface of a protruding portion arranged in the center of the width direction facing the wearer's excretion part, and on both sides of the protruding portion. Has a high-density part.

[Prior technical literature] [Patent Document]

[Patent Document 1] Japanese Patent Application Laid-Open No. 2010-131206

[Patent Document 2] Japanese Patent Application Publication No. 2015-112235

A pad-type absorbent article according to one aspect of the present invention includes an absorbent core having a front core portion, a rear core portion, and an intermediate core portion located on both end sides in the front-rear direction.

The intermediate core part is located between the front core part and the rear core part.

The length of the middle core part in the width direction orthogonal to the front-rear direction is shorter than the front core part and the rear core part.

The above-mentioned intermediate core part has: a high basis weight part located in the central area in the width direction and having a higher basis weight than the above-mentioned front core part and the above-mentioned rear core part; and a low basis weight part located in both side areas in the width direction. , and has a lower basis weight than the above-mentioned high basis weight part.

The high basis weight portion has a high basis weight and high thickness portion located at a central portion in the width direction; and a high basis weight low thickness portion located on both sides of the high basis weight and high thickness portion in the width direction and having a thickness greater than that of the high basis weight portion. The high thickness part is thin.

1:Absorbent items

4: High basis weight department

4': High basis weight

10: sanitary napkins

11:Absorbent body

12: Front sheet

12a:Skin-facing side

14: Side sheet

16: Compression groove part

20:Absorbent core

20':Absorbent core

20a:Skin-facing side

21: Front core body part

21a: Inclined part

22:Middle core part

22s: retracted area

23:Rear core body part

23a: Inclined part

24:Absorbent body

25: Low basis weight part

27: Longitudinal groove part

27c: Longitudinal groove part

28: Transverse groove part

29: Peripheral groove part

30: chip-coated material

31: Front core covering part

32: Intermediate core covering part

33: Rear core covering part

34: Retracted covering part

41: High basis weight and high thickness part

42: High basis weight and low thickness part

44: Side part

45:Front end

46:Rear end part

50:pressure roller

51: Smooth roller

53: concave part

60: Junction groove part

61: Junction groove part

65:Central area

66: Side area

70:Absorbent core

71: Block Department

291:Linear Department

292:Bending part

341: Front area

342: Back area

D1:Width

D2:Width

D3:Width

F: rear wing

M: Ontology

M1: forward area

M2: middle area

M3: rear area

P1:junction

P2:junction

W: wing

X: forward and backward direction

Y: Width direction

Z: Up and down direction (thickness direction)

Fig. 1 is a top view of a pad-type absorbent article according to one embodiment of the present invention.

FIG. 2 is a schematic plan view of the absorbent body constituting a part of the pad-type absorbent article in FIG. 1 in a single state.

Figure 3 shows the absorbent body of Figure 2 along a straight line passing through the peripheral groove portion provided on the absorbent core. This is a schematic cross-sectional view cut along line III-III of the line, and is a diagram conceptually showing the relationship between the absorbent core and the core sheet.

FIG. 4 is a plan view showing an absorbent core constituting a part of the absorbent body of FIG. 2 .

Figures 5(A) and (B) are illustrative diagrams of compressing both sides of the high basis weight part in the width direction central part of the middle core part of the absorbent core in the width direction to form a high basis weight low thickness part. In the figure illustrating the method, the cross-section of the intermediate core part is schematically shown, and the illustration of the groove part is omitted.

FIG. 6 is a diagram equivalent to FIG. 3 of another embodiment of the present invention.

Fig. 7 is a plan view showing an absorbent core as a comparative example.

Even during the menstrual period, whether on weekdays or on rest days, women have more opportunities to perform the same activities as during non-menstrual periods. If a pad-type absorbent article such as a menstrual napkin has a rectangular absorbent body, for example, when worn for a long time, the absorbent article may rub against the groin or excretory area, causing discomfort to the wearer, thereby hindering the wearer's ability to wear it. Active activities. Therefore, technology to reduce friction between absorbent articles and skin is desired.

The present invention relates to a pad-type absorbent article that can reduce the friction between the absorbent article and the wearer's skin.

[The overall composition of sanitary napkins]

Hereinafter, in each figure, the X-axis direction corresponds to the front-rear direction of the pad-type absorbent article (hereinafter, may also be referred to as an absorbent article) 1, the Y-axis direction corresponds to the width direction, and the Z-axis direction corresponds to In the up and down direction (thickness direction). The X-axis, Y-axis and Z-axis are orthogonal to each other. In this specification, regarding the Z-axis direction, the side close to the wearer's skin when wearing the absorbent article 1 is referred to as the upper side, and the side farther from the skin is referred to as the lower side.

The absorbent article 1 of this embodiment is constituted as a menstrual sanitary napkin, and is hereinafter referred to as a sanitary napkin 10 .

As shown in FIG. 1 , the sanitary napkin 10 includes a main body M, a pair of wing portions W, and a pair of rear wing portions F.

The main body M extends in the front-to-back direction X and is fixed to the inner surface (worn surface) of the wearer's underwear when wearing. The main body M has an absorber 11 and has the function of absorbing the wearer's menstrual blood and other liquid substances (hereinafter also referred to as "liquid").

The main body M has a front area M1, a middle area M2, and a rear area M3 divided along the front-rear direction X.

The front region M1 is an area arranged in front of the middle region M2 (on the wearer's abdomen), and is configured to face the front of the wearer's excretory part when worn.

The middle region M2 is configured to face the wearer's excretory part when worn. Furthermore, the middle region M2 may be located in front of the body M as shown in the figure, or may be located in the center of the body M.

The rear region M3 is a region arranged behind the middle region M2 (on the wearer's back side), and is configured to face the rear of the wearer's excretory part when worn.

The wing portion W is configured to protrude greatly toward the outside in the width direction Y from the middle region M2.

The rear wing portion F is configured to bulge outward in the width direction Y from the rear region M3.

Furthermore, the sanitary napkin 10 may not have at least one of the wings W and the rear wings F.

[The composition of various parts of sanitary napkins]

As shown in FIG. 1 , the sanitary napkin 10 includes an absorbent body 11, a front sheet 12, a back sheet (not shown), a pair of side sheets 14, and compression grooves 16. In the main body M, the sanitary napkin 10 has a structure in which a back sheet, an absorber 11 and a front sheet 12 are laminated. The sanitary napkin 10 is configured so that the skin-facing surface 12a of the front sheet 12 comes into contact with the wearer's skin when worn.

The absorbent body 11 has a front-to-back direction in the X-axis direction, and is arranged at the center of the sanitary napkin 10 in the thickness direction. The absorber 11 absorbs liquid from the surface on the front sheet 12 side, diffuses the liquid inside, and holds the liquid. The absorber 11 will be described below.

The front sheet 12 is configured as a liquid-permeable thin sheet and is placed on the absorber 11 . The front sheet 12 forms the upper outer surface of the sanitary napkin 10 in the thickness direction of the main body M.

The back sheet and the front sheet 12 are arranged to face each other in the thickness direction with the absorber 11 interposed therebetween. The back sheet forms the lower outer surface of the sanitary napkin 10 in the thickness direction. The back sheet is joined to the front sheet 12 and the side sheet 14 at, for example, the peripheral edge portion by adhesive, heat sealing, or the like.

The pair of side sheets 14 are opposed to each other in the width direction Y with the front sheet 12 interposed therebetween, and are arranged on the periphery of the sanitary napkin 10 in the width direction.

The compression groove portion 16 is configured as a linear groove formed by compressing the absorber 11 and the top sheet 12 .

(Basic composition of absorber)

As shown in FIG. 3 , the absorbent body 11 has an absorbent core 20 and a covering sheet 30 .

The absorbent core 20 has the function of absorbing and retaining liquid. The absorbent core 20 may, for example, be made of The fiber assembly may be formed of a fiber assembly containing hydrophilic fibers such as pulp fibers, or may have a structure in which the fiber assembly retains a water-absorbing polymer. Hereinafter, the member constituting the absorbent core 20 will be referred to as an absorbent member.

As shown in FIGS. 2 and 3 , the covering sheet 30 is wound around the width direction Y of the absorbent core 20 so as to cover the front and back surfaces of the absorbent core 20 . The length of the core sheet 30 along the X-axis direction is equal to the length (full length) of the absorbent core 20 in the front-rear direction X, but is not limited to this, and may be longer than the total length of the absorbent core 20. , can be shorter.

The covering sheet 30 covers the absorbent core 20 and has a function of maintaining the shape of the absorbent core 20, for example. The coating sheet is made of, for example, thin and soft paper such as toilet paper or liquid-permeable non-woven fabric. The chip-coated material 30 may be composed of one thin sheet or a plurality of thin sheets. The core sheet 30 can also be joined to the front sheet 12 and the back sheet 13 by, for example, an adhesive applied in a specific pattern.

(Constitution of absorbent core)

As shown in FIG. 4 , the absorbent core 20 has a front core part 21 located in the front region M1 , a middle core part 22 located in the middle region M2 , and a rear core part 23 located in the rear region M3 . The front core portion 21 and the rear core portion 23 are located on both end sides of the absorbent core 20 in the front-rear direction X, and the intermediate core portion 22 is located between the front core portion 21 and the rear core portion 23 . The intermediate core part 22 reaches the front side of the rear area M3 from the rear side of the front area M1 via the intermediate area M2. The absorptive core 20 has a left-right symmetrical planar shape in the width direction Y.

In FIG. 4 , widths D1, D2, and D3 are shown as dimensions in the width direction Y of the front core portion 21, the middle core portion 22, and the rear core portion 23. The width D2 of the middle core portion 22 is wider than that of the front core. Both the width D1 of the body portion 21 and the width D3 of the rear core portion 23 are short. That is, the absorptive core 20 has the middle core part 22 formed between the pair of indented areas 22s in the middle part in the front-back direction X, and has the width|variety narrower than the front core part 21 and the rear core part 23.

In this embodiment, the width D1 of the front core part 21 is the same as the width D3 of the rear core part 23. However, the width D1 of the front core part 21 and the width D3 of the rear core part 23 may be different. In addition, the widths of the front core part 21, the middle core part 22, and the rear core part 23 may also be non-uniform. In this case, the maximum dimensions in the width direction Y of the front core part 21 and the rear core part 23 can be set to widths D1 and D3 respectively, and the minimum dimension in the width direction Y of the middle core part 22 can be set to D2.

The middle core portion 22 is an excretion-part facing portion disposed to face the wearer's excretion part, that is, the vaginal opening when the sanitary napkin 10 is worn. The front core part 21 is arranged closer to the front side (ventral side) of the wearer than the middle core part 22 , and the rear core part 23 is arranged closer to the rear side (dorsal side) of the wearer than the middle core part 22 .

As shown in FIG. 4 , the front core part 21 has an inclined part 21 a at the rear end, and the rear core part 23 has an inclined part 23 a at the front end. The inclined portion 21a (23a) reduces the width of the front core portion 21 (rear core portion 23) toward the middle core portion 22. The narrowed region 22s corresponds to the space formed between both edges in the width direction Y of the intermediate core portion 22 and the inclined portions 21a and 23a.

A plurality of grooves are provided on the skin-facing surface 20a side of the absorbent core 20.

Specifically, the front core part 21 , the middle core part 22 and the rear core part 23 are provided with The longitudinal groove part 27 and the lateral groove part 28 are provided with the peripheral groove part 29 in the middle core part 22.

Furthermore, a boundary groove portion 60 is provided at the boundary portion P1 between the front core portion 21 and the middle core portion 22 , and a boundary groove portion is provided at the boundary portion P2 between the middle core portion 22 and the rear core portion 23 . Groove 61. The boundary portion P1 and the boundary portion P2 are each positioned so as to cross the absorbent core 20 along the width direction Y.

Furthermore, the boundary portion P1 refers to a portion between the front core portion 21 and the middle core portion 22 that does not belong to either of them, and the boundary portion P2 refers to a portion between the rear core portion 23 and the middle core portion 22 . It is not part of any one.

The absorbent core 20 is formed in a block shape by the longitudinal groove portion 27, the transverse groove portion 28, the peripheral groove portion 29, and the boundary groove portions 60 and 61 of the low basis weight of the absorbent member. Divide into plural pieces. These groove parts are formed in such a manner that they sink downward from the upper surface in the thickness direction (the surface located on the wearer's skin side) with respect to the square parts divided into blocks. On the other hand, the square portion is configured to protrude upward in the thickness direction.

In the absorbent core 20, the thickness of the area where the groove portion is formed, that is, the bottom portion where the groove portion is formed is relatively thin compared to the area of the square portion where the groove portion is not formed. The basis weight of the bottom forming the groove portion is relatively lower than that of the square portion, and the rigidity of the bottom of the groove portion is lower than that of the square portion. Therefore, when an external force is applied to the absorbent core 20, the absorbent core 20 is easily deformed using the groove portion as a deformation starting point.

In the following description, the basis weight of the front core part 21 , the middle core part 22 and the rear core part 23 refers to the basis weight of the square parts except the groove parts 27 , 28 , 29 , 60 , and 61 .

The vertical groove portions 27 extend along the front-rear direction X, and a plurality of them are arranged at intervals along the width direction Y. The vertical groove portion 27 is formed over the entire length of the front-rear direction X so as to divide each of the front core portion 21 , the intermediate core portion 22 , and the rear core portion 23 in the width direction Y.

The lateral groove portions 28 extend along the width direction Y and are arranged at intervals along the front-rear direction X. The lateral groove portion 28 is formed over the entire length in the width direction Y so as to divide each of the front core portion 21 , the intermediate core portion 22 , and the rear core portion 23 in the front-rear direction X. Furthermore, in this embodiment, the boundary groove portions 60 and 61 formed at the boundary portions P1 and P2 are not included in the lateral groove portion 28 . The length of the boundary groove portions 60 and 61 in the front-rear direction X, that is, the groove width, is wider than the transverse groove portion 28 .

The peripheral groove portion 29 is formed along the outer edge in the front-rear direction X of the high basis weight portion 4 described below.

Furthermore, the shape or arrangement of the longitudinal groove portion 27, the lateral groove portion 28, and the peripheral groove portion 29 are not limited to the structure shown in Fig. 4, and may be based on the shape or requirements of the absorbent core 20. Functions, etc. and set appropriately.

In this way, by providing the longitudinal groove portion 27, the transverse groove portion 28, the peripheral groove portion 29, and the boundary groove portions 60 and 61 with low basis weight and easy deformation, the flexibility of the absorbent core 20 can be improved, and To improve wearability. In addition, by providing the groove portion, the excreted liquid can be quickly introduced into the space of the groove and taken into the absorbent core 20, thereby increasing the liquid absorption speed. In addition, by dividing the absorbent core 20 into a plurality of square parts, the surface area of the absorbent core 20 can be increased, thereby efficiently absorbing and retaining liquid.

(Constitution of the middle core part)

As shown in FIGS. 3 and 4 , the intermediate core portion 22 has a high basis weight portion 4 with a relatively high basis weight of the absorbent member, and a low basis weight portion 25 with a lower basis weight than the higher basis weight portion 4 . The basis weight of the high basis weight portion 4 is higher than that of the front core portion 21 and the rear core portion 23 .

The high basis weight portion 4 is located in the width-direction central region 65 of the intermediate core portion 22 and is provided extending in the front-rear direction X. The low basis weight portion 25 extends in the front-rear direction X and is located at both widthwise side areas 66 and 66 of the intermediate core portion 22 . The pair of low basis weight portions 25 extend in the front-rear direction X and are positioned on the left and right oppositely along the width direction Y with the high basis weight portion 4 in between. The low basis weight portion 25 is located below the upper surface of the higher basis weight high thickness portion 41 . Furthermore, in the absorbent core 20, when an imaginary line is drawn that passes through the part with the largest width direction length of the high basis weight portion 4 and is parallel to the longitudinal direction X, the inner side of the imaginary line in the width direction Y is the central region. 65, and the outer side is the lateral area 66. The "portion with the largest length in the width direction of the high basis weight portion 4" is preferably present in the longitudinal center portion of the middle core portion 22 in consideration of the conformability to the wearer's groin portion.

The high basis weight portion 4 has a high basis weight and high thickness portion 41 and a high basis weight and low thickness portion 42 . The high basis weight and high thickness portion 41 is located in the center portion in the width direction. The pair of high basis weight and low thickness portions 42 are located opposite the high basis weight and high thickness portion 41 along the width direction Y on both sides of the high basis weight and high thickness portion 41 in the width direction.

The high basis weight high thickness portion 41 and the high basis weight low thickness portion 42 are located in the area provided with the shrinkage area 22s along the front-rear direction It is provided extending over the entire length in the front and rear directions.

In the sanitary napkin 10, in the middle core portion 22, the high basis weight and high thickness portion 41, the high basis weight and low thickness portion 42, and the peripheral edge are symmetrically arranged with the longitudinal groove portion 27c located at the center in the width direction as the axis of symmetry. The groove part 29 and the low basis weight part 25.

The high basis weight portion 4 is arranged to face the excretory part of the wearer when the sanitary napkin 10 is worn.

In FIG. 4 , the low basis weight part 25 is represented by a dot pattern with a relatively sparse density, and the high basis weight part 4 is represented by a dense dot pattern of the basic weight part 25 with a relatively low density. Furthermore, in the high basis weight part 4 , the density of the dot pattern of the high basis weight low thickness part 42 is expressed more densely than in the high basis weight high thickness part 41 .

The basis weight of the high basis weight and low thickness portion 42 is equal to the basis weight of the high basis weight and high thickness portion 41 . However, the basis weights of the high basis weight and high thickness portion 41 and the high basis weight and low thickness portion 42 do not need to be exactly the same. From the viewpoint of absorptive performance, the difference between the higher basis weight and the lower basis weight is divided by the basis weight. The higher value obtained is preferably within 20%, preferably within 10%. The density of the absorbent member in the high basis weight and low thickness portion 42 is higher than that in the high basis weight and thickness portion 41, and is high density. The high basis weight low thickness portion 42 is thinner than the higher basis weight high thickness portion 41 and is equal to the low basis weight portion 25 . The high basis weight and low thickness portion 42 is located between the high basis weight and high thickness portion 41 and the low basis weight portion 25 .

In the middle core part 22 , the high basis weight and low thickness part 42 has the highest rigidity, the high basis weight and high thickness part 41 has the second highest rigidity, and the low basis weight part 25 has the lowest rigidity.

As shown in FIG. 3 , the high basis weight and high thickness portion 41 in the high basis weight portion 4 is formed thicker than the lower basis weight portion 25 and the high basis weight low thickness portion 42 , and is directed upward in the thickness direction (towards the front sheet 12 side). )protrude. This ensures good fit between the central portion of the middle region M2 of the sanitary napkin 10 corresponding to the high basis weight and high thickness portion 41 and the wearer's excretory area.

In this specification, in the absorptive core 20, the part located outside the higher basis weight part 4 in the width direction Y is called the side part 44. Therefore, in this embodiment, the absorbent core 20 The portion including both the low basis weight portion 25 and the linear portion 291 of the peripheral groove portion 29 is the side portion 44 . As shown in FIG. 4 , in plan view, the side portions 44 have an elongated shape extending in the front-rear direction X, and a pair of the side portions 44 are provided to face each other in the width direction Y with the high basis weight portion 4 interposed therebetween. The pair of side portions 44 are respectively in contact with the high basis weight portion 4 and are located on both sides of the high basis weight portion 4 in the width direction Y, and are regions with a lower basis weight than the higher basis weight portion 4 .

The middle portion of the side portion 44 in the front-rear direction X has a uniform width along the front-rear direction X.

The width of the high basis weight portion 4 has a substantially semicircular shape gradually decreasing toward the front core portion 21 and the rear core portion 23 in the front portion and the rear portion respectively, and the side portions 44 follow this shape in the front and rear portions. The high basis weight portion 4 is arranged in a substantially semicircular shape. Thereby, the width of the front part and the rear part of the side part 44 becomes a shape which gradually increases from the middle part of the side part 44 in the front-rear direction X toward both front and rear end parts.

Here, a first virtual straight line along the width direction Y is drawn in the region where the straight portion 291 of the peripheral groove portion 29 of the absorbent core 20 exists. On the first imaginary straight line, the area where the high basis weight portion 4 is located is the central area 65 in the middle core portion 22 , and the area where the side portions 44 are located on one of the two sides of the high basis weight portion 4 is the side area. 66. The boundary between the central region 65 and the side region 66 extends linearly along the front-rear direction X.

A second imaginary straight line along the width direction Y is drawn in the region where the curved portion 292 of the peripheral groove portion 29 of the absorbent core 20 exists. On the second imaginary straight line, in the central region 65 , in addition to the high basis weight portion 4 , there is also a part of the side portion 44 , the boundary between the central region 65 and the side regions 66 and the high basis weight portion 4 and the side portions. The junction of 44 is inconsistent.

In this embodiment, as shown in Fig. 3, the width a of the high basis weight and high thickness portion 41, the high basis weight The width b of the low thickness portion 42, the width c of the low basis weight portion 25, and the width e of the peripheral groove portion 29 respectively represent the high basis weight high thickness portion 41 and the high basis weight low thickness portion 42 located on the first imaginary straight line. , the width length of the low basis weight portion 25 and the peripheral groove portion 29 in the width direction Y. The width f of the side portion 44 represents the width length in the width direction Y of the side portion 44 located on the first virtual straight line, and is equivalent to the width c of the low basis weight portion 25 and the width e of the peripheral groove portion 29 Those who add up the income. The contracted covering part 34 covering the contracted area 22s is located on the first imaginary straight line, and the width d of the contracted covering part 34 represents the width length in the width direction Y of the contracted covering part 34. Furthermore, when there is no peripheral groove portion 29 , the width c of the low basis weight portion 25 is the same as the width dimension f of the side portion 44 .

As shown in FIG. 3 , in the absorbent core 20 of the sanitary napkin 10 , the dimension b in the width direction Y of the high basis weight low thickness portion 42 is smaller than the dimension f in the width direction Y of the side portion 44 .

The method of providing the high-density high-basis-weight low-thickness portion 42 in the high-basis-weight portion 4 is not particularly limited. For example, as shown in FIG. 5 , the high basis weight low thickness portion 42 may be formed using press processing.

As shown in FIG. 5(A) , the middle core part of the absorbent core 20' before stamping processing has: a high basis weight part 4', which is arranged in the width direction central area 65 and has a high basis weight; and a low basis weight part 4'. The basis weight portion 25 is arranged in both side areas 66 in the width direction and has a lower basis weight than the basis weight portion 4'.

The absorbent core 20' is covered with a coating sheet (not shown), and is introduced between two rollers of a pressing device including a pressing roller 50 having a recess 53 on a part of its circumferential surface and a smoothing roller 51 having a smooth circumferential surface. Thereby, as shown in FIG. 5(B) , both sides of the high basis weight portion 4' in the width direction Y are strongly pressed and compressed, thereby forming the high basis weight low thickness portion 42. During pressurization, the distance between the pressure roller 50 and the smoothing roller 51 is set so that the low basis weight portions 25 disposed in both side areas 66 are not pressurized. Furthermore, the depth of the recessed portion 53 is set so that the area corresponding to the recessed portion 53 of the pressure roller 50 in the high basis weight portion 4' is not pressurized.

In this way, by locally compressing the high basis weight portion 4', the high basis weight portion 4 having the high basis weight and high thickness portion 41 and the high basis weight and low thickness portion 42 is formed.

The central core part 22 is provided with a peripheral groove part 29, one longitudinal groove part 27c, and four lateral groove parts 28. Here, in order to distinguish it from the longitudinal groove portions 27 provided in other core portions, the longitudinal groove portion located in the middle core portion 22 will be referred to as the vertical groove portion 27c for description, and no special distinction is required. , it is simply called the longitudinal groove portion 27.

As shown in FIG. 4 , the peripheral groove portion 29 as the first groove portion is formed between the high basis weight portion 4 and the low basis weight portion 25 so as to surround at least the periphery of the high basis weight portion 4 in the front-rear direction X. between. The peripheral groove portion 29 is provided along the side edge of the high basis weight low thickness portion 42 . The low basis weight portion 25 is provided along the side edge of the high basis weight portion 4 with the peripheral groove portion 29 interposed therebetween. The peripheral groove portion 29 has a lower basis weight than the low basis weight portion 25 .

The peripheral groove portion 29 is provided throughout the front-rear direction X, and has a straight portion 291 extending along the front-rear direction X and a curved portion 292 connected to the straight portion 291 and curved. The curved portion 292 forms the front end portion 45 and the rear end portion 46 of the high basis weight portion 4 into a substantially semicircular shape. Furthermore, the shape is not limited to a semicircle, but is preferably a shape that can disperse external forces acting in the plane, such as a triangular shape, a trapezoidal shape, or a combined shape of an arc and a straight line.

The peripheral groove portion 29 and the second groove provided in the boundary portion P2 (P1) of the middle core portion 22 and the rear core portion 23 (the front core portion 21 and the middle core portion 22) and extending in the width direction Y The groove portion, that is, the boundary groove portion 61 (60) communicates with each other.

The rear end portion 46 of the high basis weight portion 4 extending in the front-rear direction X is adjacent to the interface groove portion 61 , and the front end portion 45 of the high basis weight portion 4 is adjacent to the interface groove portion 60 .

In addition, there is no high basis weight low thickness portion 42 at the front end portion and the rear end portion of the high basis weight portion 4 . In the front-rear direction area of the intermediate core portion 22 corresponding to the high-basis-weight low-thickness portion 42 where the high-basis-weight portion 4 does not exist, the width of the low-basis-weight portion 25 extends from the front-rear direction X of the low-basis weight portion 25 The middle part gradually increases toward both ends.

The longitudinal groove portion 27c is located at the center of the width direction Y of the middle core portion 22 and is the center of the width direction Y of the high basis weight and high thickness portion 41, and is located in the width direction of each of the front core portion 21 and the rear core portion 23. The longitudinal grooves 27 in the center of Y are located on the same straight line and communicate with each other.

The four lateral groove portions 28 provided in the middle core portion 22 are arranged at equal intervals and parallel to each other so as to cross the middle core portion 22 in the width direction Y. The lateral groove portion 28 is arranged to be orthogonal to the straight portion 291 of the peripheral groove portion 29 .

(Constitution of chip-coated materials)

As shown in FIG. 2 , the core covering material 30 has: core covering parts (31 to 33) covering each part of the absorbent core 20; and a pair of shrinking covering parts 34 covering parts of the absorbent core 20. A pair of retracted areas 22s.

The core covering part includes: a front core covering part 31 that covers the front core part 21; a middle core covering part 32 that covers the middle core part 22; and a rear core covering part 33 that covers the rear core part. twenty three. In FIG. 2 , a single-point chain line represents the boundary between each core covering portion 31 to 33 and the shrinking covering portion 34 .

The covering sheet 30 includes a thin sheet material with a sufficiently lower rigidity than the absorbent core 20, and therefore covers the absorbent core 20 in a shape corresponding to the shape of the absorbent core 20. For example, the intermediate core is covered As shown in FIG. 3 , the portion 32 is deformed into a shape corresponding to the shape of the protruding portion (high basis weight portion 4 ) of the front surface 20 a of the intermediate core portion 22 .

On the other hand, the retracted covering portion 34 is installed between the front core portion 21 and the rear core portion 23 and extends from the outer edge of the middle core portion 22 to the retracted region 22s. Therefore, the contracted covering portion 34 is maintained in a shape corresponding to the contracted region 22s in a state in which fixed tension is applied in the front-rear direction X.

Inside the shrink cover part 34, as shown in FIG. 3, there is no absorbent member constituting the absorbent core 20, but fibers protruding outward from the periphery of the absorbent core 20, or fibers protruding from the absorbent core may be partially present. A portion of the absorbent member separated from the body 20. Furthermore, the retracted covering portion 34 is depicted in Figure 3 as having the same thickness as the low basis weight portion 25 of the absorbent core in the thickness direction Z, but there is basically no space in the thickness direction in the absorbent article. Preferably, the front area 341 and the back area 342 are in contact with each other.

[Function and effect of this embodiment]

By using the absorbent core 20 with a narrow width of the central core portion 22 and an overall retracted shape, in the sanitary napkin 10, the area including the retracted area 22s in the main body M has a more absorbent property. The areas of core 20 are less rigid and soft. Therefore, when wearing, although the middle area M2 of the sanitary napkin 10 is an area that receives an external force from the wearer's legs outside the width direction Y toward the inside in the width direction Y, since this area has low rigidity and is soft, Therefore, the friction between the groin and the sanitary napkin 10 can be reduced. This can provide the wearer with a comfortable feeling of use.

Moreover, in the middle core part 22 of the absorbent core 20, the high basis weight part 4 is provided in the center of the width direction Y, and the low basis weight part 25 is provided on both sides.

Furthermore, the high basis weight portion 4 has a high basis weight and high thickness portion 41 in the center of the width direction Y, and between the high basis weight and high thickness portion 41 and the low basis weight portion 25, there is a thinner portion with a higher basis weight and a higher thickness portion 41 . A pair of high basis weight low thickness portions 42 . The high basis weight and low thickness portion 42 makes it difficult for the force from the thigh applied to the low basis weight portion 25 to be transmitted to the high basis weight and high thickness portion 41 . Therefore, since the high basis weight and high thickness portion 41 is less likely to undergo unnecessary deformation, the high basis weight and high thickness portion 41 is easily in close contact with the wearer's excretory area, thereby improving the fit. Furthermore, the deformation of the middle core portion 22 in the area facing the excretory part and its periphery will locally produce higher rigidity, which may cause a strong friction feeling with the wearer's skin. However, through the internal The existence of the shrinkage area 22s also suppresses the deformation of the low basis weight portion 25 and the high basis weight low thickness portion 42, thereby reducing the friction feeling.

In addition, the structure of the present invention also has a good influence on the absorption performance. Due to the presence of the high basis weight and low thickness portion 42, the high basis weight and high thickness portion 41 becomes less likely to undergo unnecessary deformation, so the high basis weight and high thickness portion 41 becomes more likely to be in close contact with the wearer's excretory area. Since body fluids discharged from the excretory part are easily introduced into the absorbent core 20, the high basis weight part 4 becomes easier to hold more body fluids and can suppress side leakage of body fluids in the contracted part.

In addition, compared with the high basis weight and high thickness portion 41, the absorbing member of the high basis weight and low thickness portion 42 is formed more densely, and the ability to absorb liquid is more excellent. The absorbent core 20 has the function of attracting liquid from the side of the skin. The force of attracting liquid is generated by the capillary force of the absorbent core 20. The capillary force is proportional to the density of the absorbent members constituting the absorbent core. Becoming stronger in proportion to the ground. That is, by providing the high-density, high-basis-weight, low-thickness portion 42 , capillary force acts, making it easier to remove from the skin. The side absorbs liquid and prevents the attracted liquid from reaching the side edge of the absorbent core. Furthermore, since the function of the above-mentioned contracted region 22s also suppresses the deformation of the high basis weight and low thickness portion 42, it is also possible to suppress the extrusion of body fluids held by the high basis weight and low thickness portion 42 to the low basis weight during wearing. Part 25 side.

Furthermore, since the compressed high-density high-basis-weight low-thickness portion 42 is provided over the entire length of the narrow-width intermediate core portion 22 and extends in the front-rear direction The way the absorbed liquid spreads in the front-to-back direction X guides the spreading direction of the liquid, thereby further suppressing side leakage. In this way, even if the width of the intermediate core portion 22 serving as the excretion portion facing portion is narrow, side leakage can be suppressed by providing the high-density, high-basis-weight, low-thickness portion 42 .

Moreover, when wearing the absorbent body 11, if an external force is received from the wearer's legs located outside the width direction Y toward the inside in the width direction Y, typically, as shown in Fig. 3, the shrinkage area 22s will Correspondingly, the indented covering portion 34 with low rigidity, which does not have the absorbent core 20, deforms first, and then the low basis weight portion 25 deforms.

By providing the shrink area 22s in the absorbent core in this way, compared with the case of using an absorbent core without a shrink area formed with equal width across the front-to-back direction External force on body 22. Thereby, deformation of the intermediate core part 22 is suppressed, and liquid leakage caused by the deformation is suppressed. Furthermore, by suppressing the deformation of the middle core portion 22, the occurrence of deformation of the rear core portion caused by the deformation of the middle core portion being transmitted to the rear core portion is also suppressed, so that the deformation of the rear core portion can be suppressed. resulting in liquid leakage.

In the sanitary napkin 10, the high basis weight and high thickness portion 41 is formed to protrude toward the skin over the entire length of the middle core portion 22. This ensures high base weight and high thickness when wearing the sanitary napkin 10 A good sense of conformity between the thigh part 41 and the excretory part.

As described above, the absorbent article of this embodiment can reduce the friction between the groin area and the sanitary napkin, thereby providing the wearer with a comfortable feeling of use with less stiffness, and furthermore, has higher conformability to the excretory area, and It has excellent liquid absorption performance and is not easy to leak.

Furthermore, as shown in FIG. 3 , in the sanitary napkin 10 , the width b in the width direction Y of the high basis weight low thickness portion 42 is preferably smaller than the width f of the side portion. In addition, the dimension b in the width direction Y of the high basis weight low thickness portion 42 is preferably smaller than the width c of the low basis weight portion 25 . These relationships only need to be satisfied by 1/2 of the total length of the middle core portion 22 in the front-rear direction The entire length of the body 22 in the front-to-back direction X is satisfied.

Thereby, the proportion of the high basis weight and low thickness portion 42 with the highest rigidity in the middle core portion 22 in the width direction Y of the middle core portion 22 can be relatively reduced, thereby reducing the friction between the wearer's skin and the sanitary napkin 10 of friction. Furthermore, by making the width b smaller than at least one of the width c and the width f, the length from the side edge part in the width direction Y of the intermediate core part 22 to the high basis weight low thickness part 42 with high rigidity can be made become longer. That is, the width of the lower rigid lateral portion 44, preferably the lateral region 66, can be widened, thereby reducing the friction between the groin portion and the sanitary napkin 10 when worn.

Furthermore, by providing a lower basis weight peripheral groove portion 29 between the high basis weight low thickness portion 42 and the low basis weight portion 25 along the side edge of the high basis weight low thickness portion 42, the intermediate core body is increased. The softness of part 22. Thereby, when the sanitary napkin 10 comes into contact with the wearer's skin during wearing, the absorbent core 20 changes softly, and the friction at the groin is alleviated.

Furthermore, by providing the peripheral groove portion 29 that has a lower basis weight than the low basis weight portion 25 and is easily deformed, deformation around the high basis weight portion 4 is absorbed by the peripheral groove portion 29, so that the low basis weight portion The deformation of 25 becomes less likely to be transmitted to the high basis weight part 4. That is, when wearing, the external force received from the left and right leg sides is relaxed by the peripheral groove portion 29, and the external force transmitted to the high basis weight portion 4 is further reduced. Therefore, deformation of the high basis weight portion 4 can be suppressed, and liquid leakage can be suppressed.

Furthermore, by providing the junction groove portions 60 and 61, the junction groove portions 60 and 61 become a bending point when worn, so that the sanitary napkin 10 becomes easy to bend in the front-rear direction The person's body is deformed. In addition, the bending portion 292 of the peripheral groove portion 29 arranged across the front-to-back direction X also becomes a bending point when worn, and the sanitary napkin 10 becomes easy to bend and deforms along the wearer's body. Thereby, the fit is improved, friction is reduced, and the gap between the skin and the sanitary napkin 10 is reduced, thereby suppressing liquid leakage.

Furthermore, since the peripheral groove portion 29 communicates with the boundary groove portion 61 (60), the external force acting on the intermediate core portion 22 passes through the peripheral groove portion 29 and is further relaxed in the boundary groove portion 61 (60). Therefore, the intermediate core portion 22 is The deformation at the core part 22 is not easily transmitted to the rear core part 23 (the front core part 21).

In addition, the deformation generated in each of the front core part 21 and the rear core part 23 is relaxed in the boundary groove parts 60 and 61, and becomes less likely to be transmitted to the intermediate core part 22, so that high deformation can be effectively suppressed. Deformation of base weight part 4.

In addition, by providing the lateral groove portion 28 and the peripheral groove portion 29 in the middle core portion 22, the low basis weight portion 25 is divided into a plurality of square blocks, and a certain effect of sealing the deformation area in block units can be obtained. . Thereby, the transmission of external force to the high basis weight part 4 can be suppressed, and the deformation prevention effect of the high basis weight part 4 can be further improved.

In addition, as shown in FIG. 4 , there is no longitudinal groove portion 27 having a lower basis weight than the square portion in the low basis weight portion 25 of the middle core portion 22 . In other words, there is no longitudinal groove portion 27 dividing the low basis weight portion 25 in the width direction Y in the low basis weight portion 25 of the intermediate core portion 22 . Furthermore, the longitudinal groove portion 27 of the front core portion and the longitudinal groove portion 27 of the rear core portion are respectively present in front of and behind the low basis weight portion 25 . With this structure, it is possible to utilize the longitudinal groove portions 27 of the front and rear core portions to escape the load from the groin portion to the front and rear core portions while maintaining the absorption capacity of the low basis weight portion 25 of the middle core portion 22. This enables further improvement. Unexpected deformation of the high basis weight portion 4 is suppressed.

In addition, if the width of the high basis weight portion 4 is gradually narrowed from the front and rear as shown in FIG. 4 , the force exerted from the thigh to the low basis weight portion 25 will easily escape to the front and rear of the middle core portion 22 . Therefore, even if an unusually strong force is applied to the middle core portion 22 , the deformation of the middle core portion 22 can be easily suppressed. Furthermore, if the high basis weight portion 4 does not have the high basis weight low thickness portion 42 at its front end portion and the rear end portion, but only has the high basis weight high thickness portion 41 , then the width of the low basis weight portion 25 will be The low basis weight portion 25 gradually increases from the middle portion in the front-rear direction X toward both end portions, so it is easier to obtain this effect.

[Additional explanation of this embodiment]

The following is a supplementary description of this embodiment.

Numerical examples of each configuration will be described. However, these numerical values are examples and are not limited to the numerical values described here.

(Numerical examples of each component)

The widths D1 and D3 of the front core part 21 and the rear core part 23 are for menstrual sanitary napkins. is preferably 60 mm or more, further preferably 70 mm or more, and further preferably 100 mm or less, further preferably 90 mm or less.

The thickness of the front core portion 21 and the rear core portion 23 is preferably 1.5 mm or more, more preferably 2 mm or more, and further preferably 6 mm or less, further preferably 5.5 mm or less. The basis weight of the front core part 21 and the rear core part 23 is preferably 90 g/m ² or more, more preferably 100 g/m ² or more, and more preferably 350 g/m ² or less, further preferably 300 g/m 2 m ² or less.

The width D2 of the middle core portion 22 is typically formed to be larger than the crotch width of a general wearer (about 30 mm), preferably 35 mm or more, more preferably 40 mm or more, and preferably 75 mm or less, still more preferably is less than 70mm. This makes it less susceptible to the influence of external forces inward in the width direction Y caused by the wearer's legs, etc., and can also cope with the deviation of the wearing position in the width direction Y, thereby giving the wearer a sense of security.

The length of the intermediate core portion 22 in the front-rear direction X is, for example, preferably 60 mm or more, more preferably 80 mm or more, and further preferably 180 mm or less, further preferably 170 mm or less. Thereby, even when there is a deviation in the wearing position in the front-rear direction X, the intermediate core part 22 can be made to face the wearer's excretion part.

Hereinafter, regarding the width of the high basis weight portion 4 , the width of the high basis weight high thickness portion 41 , the width of the high basis weight low thickness portion 42 and the width of the low basis weight portion 25 , the width of the high basis weight portion 4 is in the front and rear direction. In the case of non-uniformity on

The width of the high basis weight portion 4 arranged in the central area in the width direction of the intermediate core portion 22 is preferably 15 mm or more, and more preferably 20 mm or more, and is preferably 60 mm or less, further preferably 50 mm or less. By setting the width to such a range, sufficient absorption capacity can be ensured.

The high basis weight portion 4 has a high basis weight low thickness portion 42 in which the thickness is locally reduced by compressing both side portions. By reducing the thickness in this way, the stiffness when worn can be reduced.

As shown in FIG. 3 , the width a of the high basis weight and high thickness portion 41 is preferably 10 mm or more, more preferably 15 mm or more, and is preferably 40 mm or less, further preferably 30 mm or less. By setting the width of the high basis weight and high thickness portion 41 serving as the protruding portion of the absorbent core 20 within such a range, the fit to the wearer's excretory area can be improved.

From the viewpoint of spreading the absorbed liquid in the front-rear direction It is preferably 10 mm or less, and further preferably 7.5 mm or less.

In addition, it is preferable if the width f of the side portion 44 is wider than the width b of the low-thickness portion 42 in basis weight, because friction caused by the sanitary napkin 10 in the groin can be further suppressed. The width f of the side portion 44 is preferably 10 mm or more, and further preferably 12 mm or more. Furthermore, it is preferably 30 mm or less, and further preferably 25 mm or less. The width c of the low basis weight portion 25 is preferably 5 mm or more, and more preferably 7.5 mm or more. Furthermore, the width c of the low basis weight portion 25 is preferably 30 mm or less, and further preferably 20 mm or less.

The width f of the side portion 44 is preferably at least 2 times the width b of the high basis weight low thickness portion 42, more preferably at least 2.5 times, and further preferably at most 5 times, further preferably at most 4 times.

In addition, the dimension b in the width direction Y of the high basis weight low thickness portion 42 is preferably smaller than the dimension d in the width direction Y of the tapered covering portion 34 . The width d of the contracted covering portion 34 is preferably 5 mm or more, more preferably 10 mm or more, and further preferably 30 mm or less, further preferably 20 mm or less.

From the viewpoint of ensuring sufficient liquid absorption capacity, the basis weight of the high basis weight portion 4 is preferably 250 g/m ² or more, further preferably 300 g/m ² or more, and further preferably 700 g/m ² or less. Furthermore, it is more preferable that it is 650g/ ^m2 or less.

From the viewpoint of reducing rigidity while maintaining appropriate liquid absorbency, the basis weight of the low basis weight portion 25 is preferably 90 g/m ² or more, further preferably 100 g/m ² or more, and further preferably 350 g/m 2 m ² or less, and more preferably 300 g/m ² or less.

The thickness of the high basis weight and high thickness portion 41 is preferably 2 mm or more, more preferably 2.5 mm or more, and further preferably 9 mm or less, further preferably 8 mm or less.

From the viewpoint of reducing a hard and solid feeling, the thickness of the high basis weight low thickness portion 42 and the low basis weight portion 25 is preferably 1.5 mm or more, more preferably 2 mm or more, and more preferably 6 mm or less, further preferably 6 mm or less. Below 5.5mm.

The difference between the thickness of the high basis weight and high thickness portion 41 and the thickness of the high basis weight and low thickness portion 42 is preferably 0.5 mm or more from the viewpoint of the conformability of the high basis weight and high thickness portion 41 to the excretory part. It is more preferably 1 mm or more, more preferably 5 mm or less, and still more preferably 4 mm or less.

The density of the high basis weight and high thickness portion 41 is preferably 0.073g/cm ³ or more, more preferably 0.091g/cm ³ or more, and further preferably 0.182g/cm ³ or less, further preferably 0.164g/cm 3 ³ or less.

The density of the high basis weight low thickness portion 42 is preferably 0.114g/cm ³ or more, more preferably 0.143g/cm ³ or more, and further preferably 0.286g/cm ³ or less, further preferably 0.257g/cm 3 ³ or less.

The density of the high basis weight and low thickness portion 42 is preferably at least 1.6 times that of the high basis weight and high thickness portion 41. However, it is preferably 1.4 times or more, more preferably 2.4 times or less, and still more preferably 2.2 times or less.

The widths of the peripheral groove portion 29, the longitudinal groove portion 27, and the lateral groove portion 28 are preferably 0.5 mm or more, more preferably 1 mm or more, and are preferably 10 mm or less, further preferably 5 mm or less.

Arranged at the boundary between the middle core part 22 and the rear core part 23 (front core part 21), in other words, between the high basis weight part 4 and the rear core part 23 (front core part 21) along the width direction Y The width of the extending boundary groove portions 61 (60) is preferably 1.5 mm or more, and more preferably 2 mm or more, and is preferably 3.5 mm or less, further preferably 3 mm or less.

The basis weight of the peripheral groove portion 29, the longitudinal groove portion 27, and the transverse groove portion 28 is lower than that of the square portion, and is preferably 50 g/m ² or more, and is preferably 250 g/m ² or less.

The numerical value in each of the above-mentioned structures can be measured by the following measurement method.

(Measurement method of width of each part of the absorbent core)

Regarding the width of the absorbent core portion, the high basis weight and high thickness portion, the high basis weight and low thickness portion, the low basis weight portion, and the width of the lateral outer portion, the width of the absorbent core can be determined by placing the absorbent core horizontally and using a microscope ( VHX-1000 (manufactured by KEYENCE Corporation) adjusts the measurement magnification to enlarge the skin-facing surface 20a to measure the width.

(Measurement method of basis weight of each part of the absorbent core)

Each part of the absorbent core 20 to be measured was cut using a single-edged razor manufactured by Feather Co., Ltd. to obtain small pieces so as to have a predetermined area. Use an electronic balance (electronic balance GR-300 manufactured by A&D Company, accuracy: 4 digits after the decimal point) to measure the weight of these small pieces. quantity. Divide the calculated weight by the area of each piece to calculate the basis weight of the piece. For each part, the average of the basis weights of the five small pieces is set as the basis weight.

(Measurement method of density in high basis weight and high thickness portions and high basis weight and low thickness portions)

The density is calculated by dividing the basis weight obtained by the same method as the measurement method of the basis weight by the thickness of the small piece to be measured.

The thickness of the small piece to be measured is measured by measuring the thickness of the small piece cut out for measuring the basis weight. A circular aluminum plate with a diameter of 25 mm, a thickness of 3 mm, and a mass of 2.45 g was placed horizontally and slowly on the measuring surface of a small piece cut out of the self-absorbent core, using a non-contact laser displacement meter manufactured by KEYENCE Corporation ( Laser head LK-G30, displacement meter LK-GD500) to measure the thickness of the sample. When the size of the cut pieces is small and difficult to measure using a non-contact laser displacement meter, you can also use a microscope (VHX-1000 manufactured by KEYENCE Corporation) to observe the cut at a magnification of 20 to 100 times. The cross section of the obtained sample was measured.

The embodiments of the present invention have been described above. However, the present invention is not limited to the above-described embodiments. It goes without saying that various changes can be made without departing from the gist of the present invention.

For example, in the above-mentioned embodiment, the high basis weight portion 4 protrudes upward in the thickness direction Z. However, it may instead have a form in which it protrudes toward the lower side in the thickness direction Z like the absorber 24 shown in FIG. 6 . Furthermore, in the above embodiment, various groove portions such as the longitudinal groove portion 27, the lateral groove portion 28, the peripheral groove portion 29, and the boundary groove portions 60 and 61 provided in the absorbent core 20 are formed in the thickness direction Z. The upper side has an opening, but it may be replaced by an absorbent body 24 as shown in FIG. 6 in the thickness direction Z. Those with openings on the side.

Furthermore, in the above-mentioned embodiment, the example of a menstrual napkin is shown as an absorbent article, but it is not limited to this. The absorbent article of the present invention may also be, for example, an incontinence pad or a vaginal secretion pad.

Hereinafter, the present invention will be further described using examples, but the present invention is not limited to these examples in any way.

(1)

A pad-type absorbent article, which is an absorbent article having an absorbent core. The absorbent core has a front core part and a rear core part located on both end sides in the front-rear direction, and the front core part is located on the front core part. The intermediate core portion is between the body portion and the rear core portion, and the length of the intermediate core portion in the width direction orthogonal to the front-rear direction is shorter than the front core portion and the rear core portion, and the intermediate core portion The body part has: a high basis weight part located in the central area in the width direction and having a higher basis weight than the front core part and the rear core part; and a low basis weight part located in both side areas in the width direction and having The basis weight is lower than the above-mentioned high basis weight part; the above-mentioned high basis weight part has: a high basis weight and high thickness part, which is located in the central part in the width direction; and a high basis weight and low thickness part, which is located between the above-mentioned high basis weight and high thickness part Both sides in the width direction, and the thickness is thinner than the above-mentioned high basis weight and high thickness part.

(2)

The pad-type absorbent article according to the above (1), wherein the width direction dimension of the low basis weight portion is larger than the width direction dimension of the high basis weight low thickness portion.

(3)

The pad-type absorbent article according to the above (1) or (2), wherein the high basis weight and low thickness portion is arranged over the entire length of the intermediate core in the front-rear direction.

(4)

The pad-type absorbent article according to any one of the above (1) to (3), wherein the intermediate core portion has a front-to-back direction between the high basis weight low thickness portion and the low basis weight portion. The first groove portion has a lower basis weight than the above-mentioned low basis weight portion.

(5)

The pad-type absorbent article according to any one of the above (1) to (4), wherein the absorbent core has a basis weight lower than that at the interface between the middle core portion and the rear core portion. The heavy part is the low 2nd groove part.

(6)

The pad-type absorbent article according to any one of the above (1) to (5), wherein the absorbent core has a basis weight lower than that at the interface between the front core portion and the middle core portion. The heavy part is the low 2nd groove part.

(7)

The pad-type absorbent article according to the above (5) or (6), wherein the intermediate core portion has a basis weight greater than that in the front-to-back direction between the high basis weight low thickness portion and the low basis weight portion. The low basis weight portion is a low first groove portion, and the second groove portion communicates with the first groove portion.

(8)

The pad-type absorbent article according to any one of the above (1) to (7), wherein the front core portion has an inclined portion at a rear end, and the rear core portion has an inclined portion at a front end.

(9)

The pad-type absorbent article according to any one of the above (1) to (8), wherein the front core part, the middle core part and the rear core part have longitudinal grooves extending in the front-rear direction. The groove portion and the transverse groove portion extending in the width direction.

(10)

The pad-type absorbent article according to any one of the above (1) to (9), wherein the basis weight of the high basis weight and low thickness portion and the basis weight of the high basis weight and high thickness portion are such that the basis weight is greater than that of the above-mentioned high basis weight and high thickness portion. The value obtained by dividing the difference between the higher basis weight and the lower basis weight by the higher basis weight is preferably within 20%, and more preferably within 10%.

(11)

The pad-type absorbent article according to any one of the above (1) to (10), wherein the front core portion has an inclined portion at the rear end, the rear core portion has an inclined portion at the front end, and the inclined portion Do not reduce its width toward the above-mentioned middle core portion.

(12)

The pad-type absorbent article according to any one of the above (1) to (11), wherein the intermediate core portion is formed between a pair of indented regions located in the middle portion of the absorbent core in the front-rear direction. , the above-mentioned absorbent core system is covered with a covering sheet material, and is further outward in the width direction than the side edge part of the above-mentioned middle core part, by erecting the above-mentioned covering sheet material between the above-mentioned front core part and the above-mentioned rear core part. material, and has an indented covering portion extending from the outer edge of the central core portion toward the indented region.

(13)

The pad-type absorbent article according to the above (11), wherein the absorbent member constituting the absorbent core does not exist inside the shrink cover portion.

(14)

The pad-type absorbent article according to the above (11) or (12), wherein the width direction dimension of the high basis weight low thickness portion is smaller than the width direction dimension of the shrink cover portion.

(15)

The pad-type absorbent article according to any one of the above (1) to (14), wherein the intermediate core portion is divided into a plurality of blocks in a block shape by transverse groove portions. In the low basis weight part of the body part, there is no longitudinal groove part that divides the low basis weight part in the width direction and has a lower basis weight than the square part of the low basis weight part, the above-mentioned front core part and the above-mentioned rear core part The portion has longitudinal groove portions in front and rear of the low basis weight portion.

(16)

The pad-type absorbent article according to any one of the above (1) to (15), wherein the width of the high basis weight portion is gradually reduced from the front portion to the rear portion.

(17)

The pad-type absorbent article according to any one of the above (1) to (16), wherein the high basis weight low thickness portion does not exist in the front end portion and the rear end portion of the high basis weight portion, and in the middle portion In the front-rear direction area of the core portion, the width of the low basis weight portion gradually increases from the middle portion side of the low basis weight portion in the front-rear direction toward both ends.

(18)

The pad-type absorbent article according to any one of the above (1) to (17), wherein the density of the high basis weight and high thickness portion is 0.073 g/cm ³ or more, and more preferably 0.091 g/cm ³ above, and preferably 0.182g/cm ³ or less, further preferably 0.164g/cm ³ or less.

(19)

The pad-type absorbent article according to any one of the above (1) to (18), wherein the density of the high basis weight low thickness portion is preferably 0.114g/cm ³ or more, and more preferably 0.143g/cm 3 cm ³ or more, and preferably 0.286 g/cm ³ or less, further preferably 0.257 g/cm ³ or less.

(20)

The pad-type absorbent article according to any one of the above (1) to (19), wherein the pad-type absorbent article is a menstrual sanitary napkin.

(twenty one)

The pad-type absorbent article according to any one of the above (1) to (20), wherein the width of the front core portion and the rear core portion is preferably 60 mm or more, and more preferably 70 mm or more, Furthermore, it is preferably 100 mm or less, and further preferably 90 mm or less.

(twenty two)

The pad-type absorbent article according to any one of the above (1) to (21), wherein the thickness of the front core portion and the rear core portion is preferably 2 mm or more, and more preferably 2.5 mm or more. , and it is preferably 7 mm or less, further preferably 6 mm or less.

(twenty three)

The pad-type absorbent article according to any one of the above (1) to (22), wherein the basis weight of the front core portion and the rear core portion is preferably 90 g/m ² or more, and more preferably It is 100 g/m ² or more, and it is preferably 300 g/m ² or less, and further preferably 250 g/m ² or less.

(twenty four)

The pad-type absorbent article according to any one of the above (1) to (23), wherein the width of the middle core portion is preferably 35 mm or more, more preferably 40 mm or more, and further preferably 75 mm. or less, and more preferably 70 mm or less.

(25)

The pad-type absorbent article according to any one of the above (1) to (24), wherein the above The length of the core body portion in the front-rear direction is preferably 60 mm or more, more preferably 80 mm or more, and further preferably 180 mm or less, further preferably 170 mm or less.

(26)

The pad-type absorbent article according to any one of the above (1) to (25), wherein the width of the high basis weight low thickness portion is preferably 2 mm or more, more preferably 3 mm or more, and more preferably It is 10 mm or less, and it is more preferable that it is 7.5 mm or less.

(27)

The pad-type absorbent article according to any one of the above (1) to (26), wherein the intermediate core portion has one of the low basis weight portions located on both sides of the width direction of the high basis weight portion. As for the side portion, the width of the side portion is preferably at least 2 times the width of the high basis weight low thickness portion, more preferably at least 2.5 times, and more preferably at most 5 times, further preferably at least 4 times. times or less.

[Example 1]

A menstrual sanitary napkin having the same basic structure as the sanitary napkin 10 shown in Figures 1 to 4 is produced. An air-through nonwoven fabric with a basis weight of 74 g/m ² is used as the front sheet 12 , a non-moisture-permeable polyethylene film sheet with a basis weight of 25 g/m ² is used as the back sheet, and a water-repellent spunbond nonwoven fabric with a basis weight of 20 g/m ² is used. As side sheets.

The absorbent core system uses the form of the indented shape shown in Figure 4 as follows, that is, the width of the middle core part 22 is 65 mm and the dimension X in the front and rear direction is 90 mm, and the width of the front core part 21 is 72 mm and the front and rear direction The dimension in the direction X is 23 mm, the width of the rear core portion 23 is 72 mm, and the dimension in the front-rear direction X is 82 mm.

The absorbent core is provided with a plurality of lateral groove portions, vertical groove portions, peripheral groove portions, and boundary groove portions in the same manner as in the form shown in FIG. 4 . The basis weight of these groove parts is 75g/m ² , and the thickness of the bottom forming the groove parts is 2 mm.

The width a of the high basis weight and high thickness portion 41 is 20 mm, and the width b of the high basis weight and low thickness portion 42 is 5 mm. The width c of the low basis weight portion 25 is 16 mm. The groove width of the peripheral groove portion 29 and the longitudinal groove portion 27c provided in the middle core portion 22 is 1.5 mm.

Five longitudinal groove portions 27 are provided in the front core portion 21 and the rear core portion 23. The width of the three longitudinal groove portions 27 located in the center is 4 mm. There are one or two longitudinal grooves on each side of 27, the width of which is 1.5mm. The size of each block portion provided in the front core portion 21 and the rear core portion 23 in the width direction is equal.

In the absorbent core 20, the groove width (dimension in the front-rear direction X) of the transverse groove portion 28 is 2 mm. The groove width of the junction groove portions 60 and 61 is 2.5 mm.

The basis weight of the front core part 21 and the rear core part 23 is 200g/ ^m2 , and the thickness is 3.5mm. In the middle core part 22 , the low basis weight part 25 has a basis weight of 200 g/m ² and a thickness of 3.5 mm, and the high basis weight part 4 has a basis weight of 440 g/m ² . By locally compressing the high basis weight portion 4, a high basis weight high thickness portion 41 and a high basis weight low thickness portion 42 are provided. The thickness of the high basis weight and high thickness portion 41 is 5.5 mm, and the thickness of the high basis weight and low thickness portion 42 is 3.5 mm. The density of the high basis weight and high thickness portion 41 is 0.080g/m ³ , and the density of the high basis weight and low thickness portion 42 is 0.126 g/m ³ .

The absorbent core in the above form is covered with a sheet sheet to form an absorbent body, and the absorbent body is sandwiched between the front sheet and the back sheet, and then side sheets are provided to produce the sanitary napkin of Example 1. . The absorber and the front sheet, the absorber and the back sheet, the side sheet and the front sheet, and the front sheet and the back sheet are joined via an adhesive.

[Example 2]

Compared with Example 1, the basis weight of the high basis weight part 4 of the middle core part 22, the thickness and density of the high basis weight high thickness part 41, the thickness and density of the high basis weight low thickness part 42, and the front and The width of the rear core part is different. Otherwise, it is a sanitary napkin with the same structure as Example 1.

In the sanitary napkin of Example 2, the basis weight of the high basis weight portion 4 is 550g/m ² . The thickness of the high basis weight and high thickness portion 41 is 7.0mm and the density is 0.079g/m ³ . The thickness of the high basis weight and low thickness portion 42 is 3.5mm and the density is 0.157g/m ³ .

The absorbent core system uses the indented shape shown in Figure 4 as follows, that is, the width of the middle core part 22 is 65 mm and the dimension X in the front and rear direction is 130 mm, and the width of the front core part 21 is 80 mm and the front and rear direction The dimension in the direction X is 36 mm, the width of the rear core portion 23 is 80 mm, and the dimension in the front-rear direction X is 137 mm.

[Comparative example]

FIG. 7 corresponds to the absorbent core described in Patent Document 2 mentioned above. The basic structure of the absorbent core in Figure 7 is different from the absorbent core described in Patent Document 2 in the number of square parts, but the width without shrinkage is uniform in the front-rear direction X and a part is compressed. The high basis weight part is common to the middle core part.

The shape of the high basis weight portion 4 of the absorbent core 70 in the form shown in Figure 7 is used, and the shape of the front and rear end portions of the high basis weight portion 4 in the above embodiment is an oblate shape that is substantially semicircular. The sanitary napkin of Comparative Example was produced in the same manner as the sanitary napkin of Example 1 except that a menstrual sanitary napkin was manufactured. The absorbent core 70 in the form shown in Figure 7 is different from the indented absorbent cores of Examples 1 and 2 in that it has an equal width in the front-to-back direction X, and its width is 72 mm. In FIG. 7 , the same components as those of the absorbent core described above are denoted by the same symbols.

The absorptive core 70 is provided with a plurality of lateral groove portions 28, vertical groove portions 27, peripheral groove portions 29, and boundary groove portions 60 and 61. The basis weight and thickness of these groove parts are the same as those in Examples 1 and 2. In the absorbent core 70, the groove widths of the longitudinal groove portion 27 and the peripheral groove portion 29 are both 1.5 mm. The groove width of the boundary groove portions 60 and 61 is the same as the transverse groove portion 28, which is 2 mm.

The three longitudinal groove portions 27 formed in the middle core portion 22 are located on the same straight line as the five longitudinal groove portions 27 respectively located in the front core portion 21 and the rear core portion 23.

The dimensions of each block portion 71 provided in the front core portion 21 and the rear core portion 23 are equal in the width direction.

The basis weight and thickness of the high basis weight portion 4 and the low basis weight portion 25 , as well as the thickness, density, and width of the high basis weight high thickness portion 41 and the high basis weight low thickness portion 42 are the same as those in Embodiment 1.

[evaluate]

By the following method, the absorbency and friction of the sanitary napkins of Examples 1 and 2 and the sanitary napkin of the comparative example were evaluated based on the following evaluation criteria, and the evaluation results are shown in Table 1.

(Evaluation method for absorbency)

The subject's menstrual sanitary napkin is fixed to menstrual shorts and worn on a dynamic model that simulates the lower body of the human body. As a dynamic model of the human body, a movable female waist model that allows the legs to walk is used. Start the walking motion of the dynamic model, and 1 minute after the start of the walking motion, inject 2g of simulated blood from the liquid excretion point (the first time). Furthermore, 3 g of simulated blood was injected (second time) 3 minutes after the end of the first liquid injection. Furthermore, 2 g of simulated blood was injected 3 minutes after the end of the second liquid injection (third time). After the third time, repeat the operation of injecting 2g of simulated blood 3 minutes after the liquid is injected, and end the liquid injection operation at the point when the simulated blood leaks out from the wings of the menstrual sanitary napkin. simulation The total weight of blood is set as the dynamic maximum absorption volume.

The simulated blood was measured using a B-type viscometer (model TVB-10M manufactured by Toki Industrial Co., Ltd., measurement conditions: rotor No. 19, 30 rpm, 25°C, 60 seconds) and the viscosity was 8 mPa. It is obtained by adjusting the ratio of blood cells and plasma of defibrinated horse blood (manufactured by NIPPON BIO-TEST LABORATORIES Co., Ltd.) using the s method.

(Friction evaluation method)

Fix the subject's menstrual sanitary napkin to menstrual shorts and wear it on the dynamic model of the human body. As a dynamic model of the human body, a movable female waist model that allows the legs to walk is used. A 3-axis tactile sensor (ShokacChip TS type, Touchence Co., Ltd.) was installed on the groin of the dynamic model, and the friction between the groin and the sanitary napkin was measured within 1 minute from the start of walking. End the walking action after 1 minute, and set the maximum shear force during walking as the amount of friction. The smaller the maximum shear force is, the smaller the friction between the groin and the sanitary napkin is.

As shown in Table 1, it can be seen that good absorption characteristics can be obtained even if the width of the central core portion is narrowed by setting the pinch, and friction is reduced by setting the pinch.

[Industrial availability]

The pad-type absorbent article according to the present invention can reduce the friction between the sanitary napkin and the skin.

4: High basis weight department

20:Absorbent core

20a:Skin-facing side

21: Front core body part

21a: Inclined part

22:Middle core part

22s: retracted area

23:Rear core body part

23a: Inclined part

25: Low basis weight part

27: Longitudinal groove part

27c: Longitudinal groove part

28: Transverse groove part

29: Peripheral groove part

41: High basis weight and high thickness part

42: High basis weight and low thickness part

44: Side part

45:Front end

46:Rear end part

60: Junction groove part

61: Junction groove part

291:Linear Department

292:Bending part

D1:Width

D2:Width

D3: Width

P1:junction

P2:junction

X: forward and backward direction

Y: width direction

Z: Up and down direction (thickness direction)

Claims (25)

A pad-type absorbent article, which is an absorbent article having an absorbent core. The absorbent core has a front core part and a rear core part located on both end sides in the front-rear direction, and the front core part is located on the front core part. The intermediate core portion is between the body portion and the rear core portion, and the length of the intermediate core portion in the width direction orthogonal to the front-rear direction is shorter than the front core portion and the rear core portion, and the intermediate core portion The body part has: a high basis weight part located in the central area in the width direction and having a higher basis weight than the front core part and the rear core part; and a low basis weight part located in both side areas in the width direction and having The basis weight is lower than the above-mentioned high basis weight part; the above-mentioned high basis weight part has: a high basis weight and high thickness part, which is located in the central part in the width direction; and a high basis weight and low thickness part, which is located between the above-mentioned high basis weight and high thickness part On both sides in the width direction, the thickness is thinner than the high basis weight and high thickness portion, and the density is higher than the high basis weight and high thickness portion; and the intermediate core portion is between the high basis weight and low thickness portion and the low basis weight portion. There is a first groove portion having a lower basis weight than the low basis weight portion throughout the front-to-back direction; and the above-mentioned intermediate core portion is formed between a pair of inward regions located in the middle portion of the front-to-back direction of the above-mentioned absorbent core, The above-mentioned absorbent core system is covered with a covering sheet material, and is further outside the side edge part of the above-mentioned middle core part in the width direction, by erecting the above-mentioned covering sheet material between the above-mentioned front core part and the above-mentioned rear core part. , and has an indented covering portion extending from the outer edge of the central core portion toward the indented region; and the low basis weight portion of the above intermediate core portion does not divide the low basis weight in the width direction. The longitudinal groove portion has a lower basis weight than the square portion of the low basis weight portion, The front core portion and the rear core portion have longitudinal groove portions in front of and behind the low basis weight portion, respectively. The pad-type absorbent article according to claim 1, wherein the width direction dimension of the low basis weight portion is larger than the width direction dimension of the high basis weight low thickness portion. The pad-type absorbent article according to claim 1 or 2, wherein the high basis weight and low thickness portion is disposed over the entire length of the intermediate core portion in the front-rear direction. The pad-type absorbent article according to claim 1 or 2, wherein the absorbent core has a second groove portion with a lower basis weight than the low basis weight portion at the interface between the middle core portion and the rear core portion. . The pad-type absorbent article according to claim 1 or 2, wherein the absorbent core has a second groove portion with a lower basis weight than the low basis weight portion at the interface between the front core portion and the middle core portion. . The pad-type absorbent article according to claim 4, wherein the second groove portion communicates with the first groove portion. The pad-type absorbent article according to claim 1 or 2, wherein the front core portion has an inclined portion at a rear end, and the rear core portion has an inclined portion at a front end. The pad-type absorbent article according to claim 1 or 2, wherein the front core part, the middle core part and the rear core part have longitudinal groove parts extending in the front-rear direction and a longitudinal groove part extending in the width direction. Transverse groove part. The pad-type absorbent article of claim 1 or 2, wherein the basis weight of the high basis weight and low thickness portion and the basis weight of the high basis weight and high thickness portion are such that the one with the higher basis weight is the same as the one with the lower basis weight. The difference divided by the higher basis weight is within 20%. The pad-type absorbent article according to claim 1 or 2, wherein the front core portion has an inclined portion at the rear end, the rear core portion has an inclined portion at the front end, and the inclined portions respectively have their widths facing the middle core. The portion is smaller. The pad-type absorbent article according to claim 1 or 2, wherein the absorbent member constituting the absorbent core is not present inside the shrink cover portion. The pad-type absorbent article according to Claim 1 or Claim 2, wherein the dimension in the width direction of the high basis weight and low thickness portion is smaller than the dimension in the width direction of the retracted covering portion. The pad-type absorbent article according to claim 1 or 2, wherein the intermediate core portion is divided into a plurality of blocks in a block shape by transverse groove portions. The pad-type absorbent article according to claim 1 or 2, wherein the width of the high basis weight portion is gradually reduced from the front portion to the rear portion. The pad-type absorbent article according to claim 1 or 2, wherein the high-basis-weight low-thickness portion does not exist at the front end portion and the rear-end portion of the high-basis-weight portion, and in the front-to-rear direction area of the intermediate core portion The width of the low basis weight portion gradually increases from the middle portion in the front-rear direction of the low basis weight portion toward both ends. For example, the pad-type absorbent article of Claim 1 or 2, wherein the density of the high basis weight and high thickness portion is 0.073g/cm3 or ^more and 0.182g/cm3 ^or less. For example, the pad-type absorbent article of Claim 1 or 2, wherein the density of the high basis weight and low thickness portion is 0.114g/cm3 ^or more and 0.286g/cm3 ^or less. The pad-type absorbent article of claim 1 or 2, wherein the pad-type absorbent article is a menstrual sanitary napkin. The pad-type absorbent article according to claim 1 or 2, wherein the width of the front core portion and the rear core portion is 60 mm or more and 100 mm or less. The pad-type absorbent article according to claim 1 or 2, wherein the thickness of the front core portion and the rear core portion is 2 mm or more and 7 mm or less. The pad-type absorbent article according to claim 1 or 2, wherein the basis weight of the front core portion and the rear core portion is 90 g/m ² or more and 300 g/m ² or less. The pad-type absorbent article according to claim 1 or 2, wherein the width of the above-mentioned intermediate core part is 35 mm or more and 75 mm or less. The pad-type absorbent article according to claim 1 or 2, wherein the length of the above-mentioned intermediate core portion in the front-to-rear direction is 60 mm or more and 180 mm or less. The pad-type absorbent article according to claim 1 or 2, wherein the width of the high basis weight low thickness portion is 2 mm or more and 10 mm or less. The pad-type absorbent article according to claim 1 or 2, wherein the intermediate core portion has a pair of side portions including the low basis weight portion located on both sides of the width direction of the high basis weight portion, and the side portions The width shall be not less than 2 times but not more than 5 times the width of the above-mentioned high basis weight and low thickness part.