WO2019220568A1

WO2019220568A1 - Absorbent body to be used in absorbent article

Info

Publication number: WO2019220568A1
Application number: PCT/JP2018/018931
Authority: WO
Inventors: 匡志宇田; 弘光田房
Original assignee: ユニ・チャーム株式会社
Priority date: 2018-05-16
Filing date: 2018-05-16
Publication date: 2019-11-21
Also published as: JP7050909B2; JPWO2019220568A1; CN111885987A; CN111885987B

Abstract

Provided is an absorbent body which is to be used in an absorbent article and is capable of exhibiting the desired ventilation properties and deformation ease, and maintaining the shape of openings while being worn. An absorbent body (13) to be used in an absorbent article (10, 80) includes an absorbent core (20) which has a plurality of openings (40) which substantially pass therethrough in the thickness direction. The openings (40) in the absorbent core (20) have a first opening section (41), and a second opening section (42) which aligns in a first direction (K1) with the first opening (41) with an interval interposed therebetween. Long fibers (30) have first fibers (31) which are positioned on a first and/or second surface around the periphery of the first opening section (41), and also have second fibers (32) which are positioned thereon around the periphery of the second opening section (42). The first long fibers (31) and the second long fibers (32) intersect one another directly or indirectly with another long fiber interposed therebetween.

Description

Absorber for absorbent articles

The present invention relates to an absorbent body for absorbent articles such as sanitary napkins and disposable diapers.

Conventionally, absorbers for absorbent articles are known. For example, Patent Document 1 discloses an absorbent core including (cellulosic) absorbent fibers, such as pulp fibers, encapsulated in a liquid-permeable sheet and shaped into a required shape, and superabsorbent polymer particles. An absorber comprising

JP 2002-35036 A (P2002-35036A)

The absorbent body disclosed in Patent Document 1 is relatively thin and has a plurality of openings that penetrate the absorbent core in the thickness direction. It is excellent in flexibility and can be deformed and fitted so as to conform to the wearer's body shape when worn.

However, when the legs are moved in a state where the absorbent body is sandwiched between the wearer's buttocks, the shape of the peripheral edge of the opening may collapse and the opening may be blocked. If the opening is blocked during wearing, the wearer may feel uncomfortable, and the breathability and followability to the body may be reduced. In order to avoid such a situation, when the absorber is made thick or the opening ratio of the plurality of openings is lowered, similarly, desired air permeability and ease of deformation cannot be exhibited.

[Technical Field] The present invention is an improvement of a conventional absorbent body for an absorbent article, and is intended for an absorbent article that can maintain the shape of the opening during wearing and exhibit desired breathability and ease of deformation. The issue is to provide absorbers.

[Means for Solving the Problems] The present invention relates to an absorbent body for absorbent articles.

An absorbent body for an absorbent article according to the present invention includes an absorbent core having a first surface and a second surface facing each other in the thickness direction, and a plurality of openings penetrating the absorbent core in the thickness direction. The absorbent core includes a water absorbent fiber and a long fiber longer than the water absorbent fiber, and the opening is spaced from the first opening and the first opening. Second long openings arranged in the first direction, and the long fibers are positioned around the first openings on at least one of the first surface and the second surface. And second long fibers located around the second opening, and the first long fibers and the second long fibers intersect each other directly or indirectly through other long fibers. It is characterized by that.

The absorbent body for absorbent articles according to the present invention has the following preferred embodiments.
(1) The first long fibers extend to the periphery of the second opening section across a separation portion located between the first opening section and the second opening section, and the second long fibers. Extends across the spaced-apart portion to the periphery of the first opening.
(2) the opening includes a second direction orthogonal to the first direction, a first imaginary line extending along the second direction so as to overlap a center of the first opening, and the second opening A second imaginary line extending in the second direction and overlapping the center, wherein the first long fiber and the second long fiber intersect the first and second imaginary lines. Cross the part.
(3) The long fibers further include third long fibers extending in the first direction, and the third long fibers intersect with the first long fibers and the second long fibers.
(4) A part of the long fibers straddles the opening.
(5) The long fibers are thermoplastic resin fibers and have an average fiber length of 6 to 70 mm.
(6) The absorbent core further includes superabsorbent polymer particles, and the superabsorbent polymer particles have a mass of 5 to 400 g / m ² .
(7) The area of each of the openings is 12 to 150 mm ² , and the ratio of the total area of the plurality of openings to the area of the absorbent core is 1 to 50%.
(8) The opening has a rectangular shape.
(9) The opening has a rhombus shape.
(10) The long fibers are uniformly arranged in the entire absorbent core.
(11) The long fibers are densely arranged in the opening edge of the opening compared to other regions.

According to the absorbent body for an absorbent article according to the present invention, it is possible to prevent the opening from being completely blocked during wearing, and to maintain desired air permeability and ease of deformation.

The drawings illustrate specific embodiments of the invention and include selective and preferred embodiments as well as the essential features of the invention.
The partially broken perspective view of the sanitary napkin using the absorber for absorbent articles which concerns on this invention. (A) The partially broken top view of an absorptive core. (B) The enlarged view of the area | region enclosed with the dashed-dotted line II (b) of FIG. The enlarged view of the area | region enclosed with the dashed-dotted line III of FIG.2 (b). The enlarged view of the 1st opening part after an absorptive core absorbs a bodily fluid. (A) The same figure as FIG. 3 in an example of the modification of an absorber. (B) The same figure as FIG. 3 in another example of a modification. (C) The same figure as FIG. 3 in another example of a modification. (A) The top view similar to FIG. 2 in an example of the other modification of an absorber. (B) The top view similar to FIG. 2 in an example of the other modification of an absorber. (C) The top view similar to FIG. 2 in an example of the other modification of an absorber. (D) The top view similar to FIG. 2 in an example of the other modification of an absorber. (E) The top view similar to FIG. 2 in an example of the other modification of an absorber. The top view of the disposable diaper which shows the other usage example of the absorber which concerns on this invention.

The following embodiment relates to the absorbent body for the disposable absorbent article shown in FIGS. 1 to 7 and includes not only an indispensable structure of the invention but also a selective and preferable structure.

1 to 3, a sanitary napkin 10 shown as an example of the absorbent article of the present invention includes a longitudinal direction Y and a lateral direction X, a skin facing surface, and a non-skin facing surface located on the opposite side. A liquid-permeable top sheet 11, a liquid-impervious back sheet 12, and an absorber 13 interposed between the two sheets.

The back sheet 12 extends further outward in the lateral direction than the top sheet 11, and a pair of side sheets 15 are fixed on the front side. An end flap 16 located outside the absorbent body 13 in the longitudinal direction Y is formed by a part of the top sheet 11, the back sheet 12, and the side sheet 15, and the back sheet 12 and the side sheet 15 form the end flap 16. A pair of side flaps 17 are also formed which are located outside in the lateral direction X and have a pair of wings that protrude outward in the lateral direction X at the central portion. The

sheets

11, 12, 15 facing each other are joined to each other via a known adhesive means, for example, a hot melt adhesive, and to each other via an outer peripheral seal portion 19 that extends along the outer periphery of the sanitary napkin 10. It is welded.

The top sheet 11 is formed of thermoplastic resin fibers such as a spunbond nonwoven fabric, a meltbond nonwoven fabric, a meltblown nonwoven fabric, a SMS nonwoven fabric in which a spunbond nonwoven fabric, a meltblown nonwoven fabric, and a spunbond nonwoven fabric are laminated. A non-woven fabric or a perforated plastic film can be used. Similarly, the back sheet 12 is made of a material commonly used in the art, for example, a liquid-impervious or moisture-permeable liquid-impervious plastic film, a fiber nonwoven fabric formed from various thermoplastic resin fibers, and a plastic film. A laminate sheet in which a fiber nonwoven fabric is bonded to the outer surface can be suitably used.

The absorbent body 13 has an absorbent core 20 shaped into a required shape, and a core wrap sheet 21 that covers the absorbent core 20. The core wrap sheet 21 is an option, and the absorbent body 13 may be formed only from the absorbent core 20 as long as the absorbent core 20 has the required shape retention. The absorber 13 is so-called semi-rigid that is higher in rigidity than each sheet, and has first and

second end edges

13a and 13b that are curved outward in the longitudinal direction Y, and first and second end edges 13a, Between both sides 13b, both

side edges

13c, 13d extending linearly in the longitudinal direction Y are provided.

Although not shown in the drawing, the mass of the absorbent core 20 is higher in the central portion of the absorbent body 13 in the longitudinal direction Y and the lateral direction X than in other regions, and the thickness dimension is larger than in other regions. Large mid-high portions can also be formed. Thus, by forming the middle-high part in the absorbent body 13, the middle-high part can be brought into close contact with the wearer's excretion port, and menstrual blood can be absorbed and retained more effectively. In addition, when the absorber 13 has a middle-high part, in order to absorb a bodily fluid more effectively, the opening part 40 does not need to be sparsely arranged in the middle-high part.

The absorbent core 20 is formed from a mixture including water absorbent fibers 25, super absorbent polymer particles (SAP (super absorbent polymer) particles) 26 and long fibers 30 longer than the water absorbent fibers 25. The water-absorbent fibers 25 include cellulose-based materials commonly used in the technical field, for example, non-wood pulp made from softwood or hardwood, hemp, cotton, etc., and recycled cellulose fibers such as rayon fiber. Semi-rigid fibers such as acetate fibers are preferably used.

As the SAP particles 26, those well known in the art can be used. For example, particles formed of polyacrylic acid, polyacrylic acid salt, starch acrylonitrile copolymer, polyvinyl alcohol, polyvinyl ether, polyacrylamide, carboxymethyl cellulose, natural polysaccharide, etc. can be used.

The long fiber 30 is a natural fiber or a synthetic fiber having a fiber length longer than that of the water-absorbing fiber 25. Preferably, a thermoplastic resin fiber is used. The thermoplastic resin fiber is a single fiber formed by using a single component such as polyethylene (PE), polypropylene (PP), polyethylene terephthalate (PET), nylon, or a composite fiber composed of a plurality of these components.

The composite fiber preferably contains at least two kinds of components having different melting points, such as core-sheath fiber, side-by-side fiber, sea-island fiber, flat fiber, Y-shaped fiber, C-shaped fiber, etc. Is used. In particular, from the viewpoint of industrial inexpensiveness, a core-sheath fiber such as a PET / PE, PP / PE (core / sheath part), etc. core-sheath fiber whose melting point of the sheath part component is lower than the melting point of the core part component. Are preferably used. Regarding the mass ratio, the cross-sectional area ratio, and the diameter ratio of the core component and the sheath component, in consideration of the required crimp rate, spinnability at the time of manufacture, etc. On the other hand, if the ratio of the sheath component is too large, the spinnability tends to decrease. Therefore, it is necessary to adjust appropriately, for example, the ratio is 10/90 to 90/10, preferably, 30/70 to 70/30. The “melting point” of the thermoplastic resin fiber means a peak top temperature of an endothermic peak when changing from a solid state to a liquid state when measured at a temperature rising rate of 10 ° C./min in a differential running calorimeter. As the differential running calorimeter, for example, a DSC-60 type DSC measuring apparatus manufactured by Shimadzu Corporation can be used.

The core wrap sheet 21 is used for shape retention of the liquid diffusible and absorbent core 20, and is made of thermoplastic resin fibers and subjected to a hydrophilic treatment in addition to tissue paper. Nonwoven fabrics and the like can be used. The core wrap sheet 21 may be a single sheet that covers the entire absorbent core 20, an upper core wrap sheet that covers the skin facing surface side of the absorbent core, and a non-skin facing surface. You may form from the several sheet | seat with the lower core wrap sheet | seat which covers the side.

2 (a) and 2 (b), the absorbent core 20 has a plurality of openings 40 that are spaced apart from each other in the vertical direction Y and the horizontal direction X. The absorber 13 (absorbent core 20) has a longitudinal center line P that bisects the dimension in the horizontal direction X and a transverse center line Q that bisects the dimension in the vertical direction Y.

The openings 40 have a substantially square shape and are arranged in a so-called zigzag pattern arranged at equal intervals in the horizontal direction X and the vertical direction Y, and are oblique with respect to the vertical center line P and the transverse center line Q. A plurality of rows 50 extending are formed. Specifically, a plurality of columns 50 are formed along a first direction K1 that is inclined with respect to the longitudinal center line P and the transverse center line Q, and each column is perpendicular to the first direction K1. The two directions K2 are spaced apart from each other. The first direction K1 can intersect with the longitudinal center line P at an appropriate inclination angle, but in the illustrated example, the first direction K1 intersects with an inclination of about 45 degrees. The plurality of openings 40 may be arranged at different intervals instead of at equal intervals.

Thus, by forming the plurality of openings 40 in the absorbent core 20, the breathability is excellent, and the inside of the sanitary napkin 10 after absorbing the body fluid can be prevented. Further, the absorbent core 20 is excellent in flexibility, and is bent at a plurality of locations starting from the vicinity of the opening 40 in a state where the absorbent body 13 is sandwiched between the wearer's buttocks. It can be deformed along the shape.

Referring to FIG. 2 (b), the length t1 of one side of the opening 40 is 4 to 15 mm, preferably 6 to 12 mm. When the length t1 of one side is less than 4 mm, the opening 40 is easily crushed during wearing, and the air permeability may be reduced. On the other hand, when the length t1 of one side exceeds 15 mm, the opening 40 becomes relatively large, and there is a risk of giving anxiety about absorbency to the wearer and / or the wear assistant. Actually, body fluids such as menstrual blood and urine are not easily transferred to the absorber 13, and the absorption performance may be reduced.

The separation dimension R1 between the openings in the first direction K1 and the separation dimension R2 between the openings in the second direction K2 are substantially the same, and are 4 to 15 mm, preferably 6 to 12 mm. When the separation dimensions R1 and R2 are less than 4 mm, the opening 40 is liable to be crushed during wearing and the air permeability may be reduced, and the ratio of the opening 40 increases, and the wearer and / or There is a risk of anxiety about absorbability for the wearer. On the other hand, when the separation dimensions R1 and R2 exceed 15 mm, the ratio of the opening 40 is relatively small, and the required air permeability and deformability may not be exhibited.

FIG. 3 is an enlarged view in which the region surrounded by the alternate long and short dash line III in FIG. 2B is rotated about 45 degrees counterclockwise for convenience of explanation. The first row 51 includes first and

second openings

41 and 42 that are separated from each other in the first direction K1. The second row 52 adjacent to the first row 51 in the second direction K2 includes third and

fourth openings

43 and 44 that are separated from each other in the first direction K1. The first opening 41 and the second opening 42, and the third opening 43 and the fourth opening 44 are opposed to each other via spaced

portions

71 and 72 positioned therebetween in the first direction K1. positioned. 2A, 2 </ b> B, and 3 are planar views of the skin facing surface side (first surface side) of the absorbent core 20, the skin facing surface of the absorbent core 20. It is preferable that at least one of the side (first surface side) and the non-skin facing surface side (second surface side) has the illustrated mode. 3 and 4, for the convenience of description, the long fibers 30 forming the network structure around the first to fourth openings 41-44 are shown as black thick lines, and the network structure around the other openings 40 is shown. The long fibers 30 to be formed are indicated by thin black lines.

Further, in the following, the configuration of the long fibers 30 positioned around the first to fourth openings 41-44 in the first and

second rows

51, 52 will be described, but in all the openings 40 in each row 50, Has the same configuration except for a part. In addition, regarding the network structure of the long fibers 30 around the opening 40, the other opening 40, the second opening 40, the second opening 51-52, which are positioned side by side with the first to fourth openings 41-44 of the first and

second rows

51, 52, are provided. The openings 40 in the rows adjacent to the first and

second rows

51 and 52 in the direction K2 have the same configuration, but are omitted from the drawings for convenience of explanation. In order to maintain the shape of each opening 40, it is preferable that all the long fibers 30 located around each opening 40 intersect each other directly or indirectly.

The first and

second openings

41, 42 respectively include

outer end sides

41a, 42a and opposing

sides

41b, 42b extending in the second direction K2, and first and second side sides (both sides) extending in the first direction K1. ) 41c, 41d, 42c, 42d. Similarly, the third and

fourth openings

43 and 44 respectively include

outer end sides

43a and 44a extending in the second direction K2, opposing

sides

43b and 44b, and first and second side sides extending in the first direction K1. (Both sides) 43c, 43d, 44c, 44d.

As described above, the absorbent core 20 includes the water-absorbing fibers 25, preferably the long fibers 30 preferably made of thermoplastic resin fibers, and optionally SAP particles 26. The long fiber 30 has a shape-retaining long fiber 31 located around the first opening 41 and a shape-retaining long fiber 32 located around the second opening 42 in the first row 51. Here, “the shape-retaining

long fibers

31, 32 are positioned around the first and

second openings

41, 42” means that the shape-retaining

long fibers

31, 32 are respectively the first openings 41. The

first side

41c, 42c extending in the first direction K1 of at least the first and

second openings

41, 42 and the opposite extending in the second direction K2 so as to surround the entire outer periphery of the first opening 42 and the second opening 42. It means extending along the

sides

41b and 42b.

In the illustrated embodiment, the shape-retaining long fibers 31 located around the first opening 41 are formed from the first opening 41 and the second opening 42 from the outside of the first side 41 c of the first opening 41. And extends to the periphery of the second opening 42 (on the second side 42d side of the second opening 42) across the spacing portion 71 located between the two. In addition, the shape-retaining long fibers 32 located around the second opening 42 cross the separation portion 71 from the outside of the first side 42c of the second opening 42 and surround the first opening 41 (first The first opening 41 extends to the second side 42d side). In this way, the shape-retaining

long fibers

31 and 32 extend toward the

openings

41 and 42 facing each other, so that they intersect each other directly at the separated portion 71.

In the second row 52, similarly to the first row 51, the shape-retaining long fibers 33 are located around the third opening 43, and the shape-retaining long fibers 34 are located around the fourth opening 44. Yes. In addition, the shape-retaining long fibers 33 cross the separation portion 72 located between the third opening 43 and the fourth opening 44 from the outside of the first side 43 c of the third opening 43 to the fourth. It extends to the periphery of the opening 44 (the second side 44d side of the fourth opening 44). The shape-retaining long fiber 34 crosses the separation portion 72 from the outside of the first side 44c of the fourth opening 44 and surrounds the third opening 43 (the second side 43d side of the third opening 43). The shape-retaining long fibers 33 and the shape-retaining long fibers 34 intersect each other directly at the spacing portion 72.

Also, the long fibers 30 have connecting long fibers 35-37 extending in the first direction K1 so as to intersect with the shape-retaining

long fibers

33, 34 located around the respective openings 41-44. The connecting long fibers 35-37 are, in the second direction K2, the connecting long fibers 35 located outside the second row 52 and the connecting long fibers located between the first row 51 and the second row 52. 36 and the connecting long fibers 37 located outside the first row 51. Specifically, the connecting long fibers 35 extending substantially linearly in the second direction K2 intersect the shape-maintaining

long fibers

33, 34, and the connecting long fibers 36 extending while curving in the second direction K2 are shaped. The connecting long fibers 37 that intersect with the long fibers 31-34 and extend substantially linearly in the second direction K2 intersect with the shape-retaining

long fibers

31, 32. In this way, the shape-retaining long fibers 31-34 intersect each other directly or indirectly via the connecting long fibers 35-37, so that the periphery of each opening 41-44 is long. A network structure by the fibers 30 is formed.

Here, the fact that the long fibers 30 cross each other includes not only simply overlapping each other in the thickness direction of the absorbent core 20 but also including entanglement of the fibers. The entanglement of fibers includes not only physical entanglement of fibers, but also the case of forming an entanglement point in which thermoplastic resin fibers are thermally fused together by heat treatment during production. The long fibers 30 of the present embodiment include all aspects of simple intersections, physical entanglement, and entanglement points by fusion, and in order to form a strong network structure by the long fibers 30, simple intersections. It is preferable to include more portions that are physically entangled than portions, and it is more preferable to include more tangled points that are heat-sealed than portions that are physically entangled.

Referring to FIG. 4, when the sanitary napkin 10 is worn, the excreted body fluid is absorbed and held in the absorbent core 20 and the water absorbent fibers 25. Specifically, while being absorbed by the water absorbent fibers 25 and the SAP particles 26, body fluid is temporarily stored in the fiber gap, but the absorbent body 13 is sandwiched between the wearer's buttocks, A pressing force directed inward acts on both side edges of the absorbent body 13, and the plurality of openings 40 formed in the entire area of the absorbent core 20 may collapse and be blocked. In addition, the SAP particles 26 that have absorbed and retained the body fluid swell and gel, and a plurality of SAP particles 26 gather to form a lump. When the SAP particles 26 gel and become a lump, the lump part tends to enter the first opening 41, and the shape of the peripheral edge collapses, making it difficult to maintain the opening shape before excretion. . Thus, when the opening area of the 1st opening part 41 shrinks | closes or completely obstruct | occludes, there exists a possibility that the absorptive core 20 cannot exhibit desired air permeability and a deformation | transformation ease.

In the present embodiment, the shape-retaining long fibers 31-34 are located around the respective openings 41-44, and in plan view, they are directly and / or single or plural other long fibers. By forming a network structure by indirectly intersecting with each other, it is possible to suppress the shape of the openings 41-44 from collapsing. Therefore, even if the absorbent body 13 is pinched between the buttocks of the wearer and the SAP particles 26 are agglomerated to block the opening 41-44, the opening 41-44 is completely blocked. There is no. In other words, by retaining the opening area to a certain extent, the desired air permeability and ease of deformation can be exhibited, and the ability to follow stuffiness and body movement during wear is reduced. can do. Referring to FIG. 4, the SAP particles 26 swell and gel after absorption of the body fluid to form a plurality of massive portions. By forming the massive portion of the SAP particles 26, the first opening 41 is deformed and cannot maintain the rectangular shape before wearing, and has changed into an irregular shape. The

long fibers

31, 32, 36, and 37 located around 41 are not completely closed by forming a network structure, and have a required opening area.

In order to retain the first to fourth openings 41-44, the shape-retaining long fibers 31-34 preferably extend so as to surround the entire circumference of each opening 41-44. In the wearing state, each of the openings 41-44 is not completely closed, and it is preferable that the openings 41-44 are positioned around the openings so that the opening area can be maintained to a certain extent. Specifically, the shape-retaining long fibers 31-34 located around the opening 41-44 are overlapped with the center points O1 to O4 of one opening 41-44 located around the second direction. Virtual lines N1 and N2 extending along K2, that is, extending in parallel to the transverse center line Q, overlap with the center point O1-O4 of the other opening 41-44 opposite to the one opening 41-44. It is preferable to cross the separated

portions

71 and 72 so as to intersect the virtual lines N1 and N2 extending in the second direction K2.

More specifically, for example, one end of the shape-retaining long fiber 31 located around the first opening 41 is outside the second direction K2 of the first side 41c of the first opening 41. While intersecting with the imaginary line N1 of the first opening 41, the central portion thereof intersects with the central portion of the shape-retaining long fibers 32 located around the second opening portion 42 at the separation portion 71, and the other end is the second. On the outside of the second side 42d of the opening 42 in the second direction K2, it is positioned so as to intersect with the virtual line N2 that overlaps the center point O2 of the second opening 42 and extends in the second direction K2. The shape-retaining long fibers 32-34 located around the second to fourth openings 42-44 have the same form. In the present embodiment, since the openings 40 have the same shape and size, the openings 40 aligned in the second direction K2, that is, the first opening 41, the third opening 43, and the second opening are arranged. 42 and the fourth opening 44, the imaginary lines N1 and N2 overlapping the respective center points O1 to O4 coincide with each other. However, in the case of different sizes and shapes, of course, the imaginary lines N1 and N2 Are different.

It is possible to retain each opening 41-44 by forming a network structure by crossing the shape-retaining long fibers 31-34 directly, but in this embodiment, in the first direction By crossing indirectly through the connecting long fibers 35 extending to K1, a stronger network structure can be formed, and higher shape retention can be exhibited. In the absorbent core 20, body fluid is temporarily stored in the plurality of openings 40, but is quickly absorbed and diffused by the water absorbent fibers 25 and the SAP particles 26 located on the inner peripheral surface of the openings 40. .

The plurality of openings 40 are essentially through-holes that penetrate the absorbent core in the thickness direction, but it is difficult to exclude all long fibers from the openings 40 in the manufacturing process. 40 includes a case where a part of the long fiber is located slightly. Referring to FIG. 3, a part 30 a of the long fiber 30 straddles the third opening 43. As described above, the part 30a of the long fiber straddles the opening 40, thereby acting together with the network structure located around the opening 40 so as to prevent the opening 40 from being crushed and blocked during wearing. can do. Moreover, the water absorption fiber which consists of a pulp fiber may be entangled in a part of long fiber. In such a case, the network structure by the long fibers 30 is further strengthened.

The long fiber 30 is a thermoplastic resin fiber, and has an average fiber length of 6 to 70 mm, preferably 15 to 40 mm. When the average fiber length of the long fibers 30 is less than 6 mm, any thermoplastic resin fiber tends to be difficult to be entangled with other thermoplastic resin fibers and / or the water absorbent fibers 25. When the average fiber length exceeds 70 mm, the opening property of the thermoplastic resin fiber is remarkably lowered, and the absorbent body 13 includes the thermoplastic resin fiber that is not opened in a part of the absorbent body 13. There is a risk that the uniformity of the film will be reduced.

The water-absorbent fibers 25 are mainly pulp fibers having an average fiber length of 2 to 5 mm, and are mixed with the absorbent core 20 and positioned in the separated

portions

71 and 72, so that the openings 40 are slightly retained. Although it may contribute to shape, the opening 40 used in the present embodiment is formed to be relatively large, so that the pulp fiber crosses the spaced

portions

71 and 72 from the periphery of the opening 40. It does not extend to the periphery of another opening 40 facing in the one direction K1. Since the long fibers 30 are longer than the pulp fibers and at least longer than the lengths of the separation portions 71 and 72 (separation dimensions R1 and R2), they contribute to the shape retention of each opening 40 compared to the pulp fibers. Yes.

<Measurement method of average fiber length>
The average fiber length of the thermoplastic resin fibers of the long fibers 30 and the fibers other than the pulp fibers of the water-absorbing fibers 25, for example, regenerated cellulose fibers and semi-synthetic fibers, is “A7” in Annex A of JIS L 1015: 2010. .1 Measurement of fiber length "according to" A7.1.1 Method of measuring length of individual fibers on glass plate with A method (standard method) scale ". The above method is a test method corresponding to ISO 6989 issued in 1981. Moreover, the average fiber length of a pulp fiber means a weight weighted average fiber length, and is measured by Kajaani Fiber Lab Fiber Properties (off-line) manufactured by Metso Automation Co., Ltd. [kajaani Fiber Lab fiber properties (off-line)] Means L (w) value.

The mass of the SAP particles 26 is 5 to 400 g / m ² , preferably 10 to 300 g / m ² . The SAP particles 26 swell to several tens to several hundreds times their own weight by absorbing bodily fluids, and thus act to close the opening 40, and preferably have a mass as low as possible. If the mass of the SAP particles 26 is less than 5 g / m ² , the absorption capacity of the absorbent core 20 is reduced, and all excreted body fluids cannot be absorbed and retained, and there is a risk of causing side leakage. On the other hand, when the mass of the SAP particles 26 exceeds 400 g / m ² , the portions of the SAP particles 26 that gel and become agglomerate are relatively large, and the openings 40 are surrounded by the network structure of the long fibers 30. Even if it exists, there exists a possibility that this block-shaped part may approach so that the whole peripheral part of the opening part 40 may be crushed, and may obstruct | occlude.

The area per opening 40 is 12 to 150 mm ² . When the area per opening 40 is less than 12 mm ² , the opening 40 becomes relatively small and may be blocked during wearing, and air permeability may be reduced. On the other hand, when the area per opening 40 exceeds 150 mm ² , the opening 40 appears to be relatively large, and the wearer and / or the wearing assistant can absorb the absorbent 13. May cause anxiety.

The ratio of the total area of the plurality of openings to the area of the absorbent core is 1 to 50%. The area of the opening 40 is larger than the opening defined in the absorbent body (absorbent core) of the conventional absorbent article, and the internal air is surely passed through each opening 40. And can function as an inflection point of the absorbent core 20 during wearing. Since the opening 40 has a relatively large area, it is held by the network structure of the long fibers 30 and is pressed between the wearer's crotch parts or is crushed by the massive part of the SAP particles and slightly opened. Even if the area is reduced, it is not completely occluded.

It is preferable that the long fibers 30 are disposed substantially uniformly throughout the absorbent core 30 in order to effectively retain the shape of the opening 40. The long fibers 30 are disposed substantially uniformly throughout the absorbent core 30, so that the absorbent core 30 has relatively high rigidity even when the absorbent core 30 is thin. Even if a force for closing the opening 40 from the lateral direction X is applied, the force applied by the entire absorbent core 30 can be received and the opening 40 can be prevented from closing.

Further, the long fibers 30 may be arranged more densely at the opening edge of the opening 40 than at other regions in order to effectively retain the opening 40. For example, among the long fibers 30 mixed in the absorbent core 20, the shape-retaining long fibers 31-34 and the connecting long fibers 35-37 located around the openings 41-44 are the openings 41-44. Although the long fibers 30 that can contribute to shape retention but are not located around the openings 41-44 do not contribute much to the shape retention of the openings 41-44, they are arranged relatively sparsely. It may be.

The opening 40 is a rectangle with the same length and the same length of each side, that is, a substantially square shape, and the corner portion has a sharp shape. Since the corner portion has a sharp shape, the long fibers 30 are positioned in a bent state in the periphery thereof as compared with the case where the corner portions are curved, so that the long fibers 30 are more entangled. It becomes easy to form a network structure.

Moreover, even if the force which goes to the inner side of the horizontal direction X by a collar part acts on the absorber 13 at the time of wear with respect to the absorber 13 by the square of the opening part 40, it is applied by the both sides extended linearly so that it may cross | intersect it The force can be widely received and the opening 40 can be prevented from being blocked. In addition, the opposing sides extending in the lateral direction X of the plurality of square-shaped openings 40 face each other through the separating

portions

71 and 72, thereby causing the separating

portions

71 and 72 in the longitudinal direction Y along the body shape. Can be bent.

Unlike the illustrated example, the opening 40 may be arranged such that the first direction K1 is parallel to the longitudinal centerline P and / or the transverse centerline Q. However, when the wearer moves the thigh in the wearing state by extending the first direction K1 so as to be inclined with the longitudinal centerline P and / or the transverse centerline Q as in the illustrated example. It can be said that the opening 40 is less likely to be blocked by receiving the force acting on the generated absorber 13 acting obliquely by the sides extending obliquely.

The opening 40 may have a rectangular shape that is long in the first direction K1 or the second direction K2, that is, a rectangular shape. Since the opening 40 has a rectangular shape, the length of the side extending in the first direction K1 and the length of the side extending in the second direction K2 are different from each other. Arranged in a bent state, it can be said that more long fibers 30 are entangled. In addition, the opening 40 may not be rectangular but may be circular, elliptical, rhombus, or polygonal as long as a required technical effect can be exhibited.

In particular, when the opening 40 has a rhombus shape and the dimension in the lateral direction X is larger than the dimension in the longitudinal direction Y of the opening 40, the fibers in the lateral direction X are produced according to the manufacturing method described later. Are easily oriented, and it can be said that the opening 40 is hardly blocked by the force applied in the lateral direction X. On the other hand, when the opening 40 has a rhombus shape and the dimension in the longitudinal direction Y of the opening 40 is larger than the dimension in the lateral direction X, according to the manufacturing method described later, the fibers are in the longitudinal direction Y. Since it becomes easy to orientate, the rigidity with respect to the vertical direction Y improves the opening part 40, for example, can improve the fitting property of a wearer's vaginal opening vicinity. Further, the openings 40 may not be the same shape and the same size, but may be different sizes and shapes. For example, each row 50 is a combination of a rectangular shape and a circular shape opening portion 40 having different sizes. It may be formed.

As described above, the long fiber 30 can be formed of a composite fiber, for example, a core-sheath fiber including a core part and a sheath part having a melting point lower than that of the core part. When the long fibers 30 are formed from core-sheath fibers, the long fibers 30 made of thermoplastic resin fibers can be welded to each other at the entanglement point at a relatively low set temperature in the heat treatment of the manufacturing process. Can be crimped. When the long fibers 30 are crimped, they can be easily entangled with each other and a stronger network structure can be formed. Further, the long fiber 30 may have a plurality of types of composite fibers having different crimping rates. In such a case, when the degree of crimping of the long fibers 30 is different, the fibers can be entangled irregularly to form a stronger network structure. In addition, as heat processing of a manufacturing process, there exist the pressurization and heating process performed in order to shape the absorptive core 20, the hot embossing performed on the surface of the sanitary napkin 10, etc., for example. By performing these heat treatments, at least a part of the long fibers 30 located on the heat-treated surface of the absorbent core 20 is melted.

Regarding the manufacturing method of the absorbent core 20, a manufacturing method commonly used in this kind of field can be used, and for example, it can be manufactured by the following method.

The manufacturing apparatus of the absorbent core 20 includes a duct and a molding drum having a concave mold frame on the circumferential surface, which is positioned opposite to the duct, and passes through each supply path positioned upstream of the duct, and the SAP particles 26. The long fibers (thermoplastic resin fibers) 30 and the water-absorbing fibers 25 are supplied into the duct. Inside the duct, air is sucked from the inlet of the duct toward the outlet through the suction mechanism of the molding drum. The SAP particles 26, the long fibers 30, and the water-absorbing fibers 25 fly on the inside of the duct while being carried on the airflow, are mixed and become a core material, and move toward the outlet.

When the rotating forming drum faces the outlet of the duct, air is sucked from the formwork toward the inside of the drum through the suction mechanism, so that the mixed core material is deposited on the formwork. A plurality of protrusions are disposed on the bottom surface of the mold, and the core absorbent material is not deposited on the protrusions. After that, the core material deposited on the mold approaches the conveyor by the rotation of the molding drum while being held in the mold by the suction force of the suction mechanism, and is suctioned by the suction mechanism located below the conveyor when facing the conveyor. The core material is pulled from the formwork onto the conveyor by force. Thereafter, the core material is compressed in the pressurizing / heating compression process by the traveling conveyor to become the absorbent core 20.

According to such a manufacturing method, when the core material is deposited on the mold of the molding drum, the plurality of openings 40 are formed in the absorbent core 20 by not being deposited on the plurality of protrusions arranged on the bottom surface of the mold. Can be formed. Moreover, since the long fiber 30 which goes to a projection part from a duct hits a projection part and is bounced to the periphery, it will be located in the periphery so that a projection part may be enclosed in planar view. Similarly, the long fibers 30 are also bounced in the plurality of protrusions, so that the long fibers 30 positioned around the protrusions intersect each other directly or indirectly in plan view. However, in such a manufacturing method, for example, the network structure may be formed by intersecting the long fibers 30 by making the shape of the protruding portion sharp and preventing it from splashing around its periphery. Prior to mixing the SAP particles 26 in the duct, the long fibers 30 and the water absorbent fibers 25 are mixed in the conveying path for a relatively long time before the shape of the protrusions is sharpened. The long fibers 30 and the long fibers 30 and the water-absorbing fibers 25 are well blended and entangled with each other, so that the entangled state is maintained when depositing on the mold of the molding drum. Good.

Further, as another manufacturing method, for example, in the above manufacturing process, after the core material is taken from the molding drum to the conveyor without arranging a plurality of protrusions on the bottom surface of the mold frame of the molding drum, Before or after that, the plurality of openings 40 can be formed by inserting and pulling out the core material without cutting the core material with a plurality of sharp pins. Even in such a case, the long fibers 30 scraped by the sharp pins are positioned in the periphery so as to surround the opening 40 in plan view, and the long fibers 30 positioned in the periphery of each opening 40. Can cross each other indirectly or directly. However, in such a manufacturing method, in order to insert a sharp pin into the absorbent core 20 without substantially cutting the long fibers 30 to form a plurality of openings 40, the mass of the long fibers 30, the distribution range, It is necessary to appropriately adjust all conditions such as the distribution area, the size and opening ratio of the opening 40, the conveyance speed of the absorbent core 20 on the conveyor, and the insertion speed of the pins.

<Measurement method of thickness of absorber>
The thickness (mm) of the absorber 13 is FS-60DS [measurement surface 44 mm (diameter), measurement pressure 3 g / cm ² ] manufactured by Daiei Kagaku Seisakusho Co., Ltd., and is in a standard state (temperature 23 ± 2 ° C.). , Relative humidity of 50 ± 5%), pressurize five different parts of the absorber 13, measure the thickness after 10 seconds of pressurization at each part, and calculate the average value of the five measured values of the absorber 13. The thickness dimension.

Fig.5 (a) is a figure similar to FIG. 3 which shows an example of the modification of the absorber 13 for absorbent articles which concerns on this invention. In this modification, each opening 41-44 has a circular shape instead of a rectangular shape. The circular shape-retaining long fibers 31-34 located around the openings 41-44 overlap with the center points O1 to O4 of the openings 41-44 located around the openings 41-44 in the second direction K2. An imaginary line (not shown) extending along the transverse center line Q, and the center point O1-O4 of the opening 41-44 facing each opening 41-44 located in the periphery The crossing

portions

71 and 72 are crossed so as to intersect with an imaginary line (not shown) extending in the second direction K2 so as to overlap. Therefore, the openings 41 to 44 can be retained by the network structure of the long fibers 30 so that the openings 41 to 44 are not completely closed.

FIG.5 (b) is a figure which shows another example of the modification of the absorber 13 for absorbent articles which concerns on this invention. In the present modification, the shape-retaining long fibers 31 positioned around the first opening 41 extend in a curved shape so as to surround the half circumference of the first opening 41, and the second opening 42 The shape-retaining long fibers 32 located in the periphery extend in a curved shape so as to surround the half circumference of the second opening 41. These shape-retaining

long fibers

31 and 32 intersect each other directly at the separated portion 71, but do not indirectly intersect with each other via the connecting long fibers 35-37. Even in such a case, the shape retaining

long fibers

33 and 34 intersect each other only directly, so that a network structure capable of retaining the openings 41 to 44 can be formed. The shape-retaining

long fibers

33 and 34 located around the third and

fourth openings

43 and 44 also have the same form as the shape-retaining

long fibers

31 and 32.

FIG.5 (c) is a figure which shows another example of the modification of the absorber 13 for absorbent articles which concerns on this invention. In the present modification, the shape-retaining long fibers 31 positioned around the first opening 41 extend in a curved shape so as to surround the half circumference of the first opening 41, and the second opening 42 The shape-retaining long fibers 32 located in the periphery extend in a curved shape so as to surround the half circumference of the second opening 42. The shape-retaining

long fibers

31 and 32 are spaced apart and opposed to each other in the first direction K1 at the separation portion 71, and do not directly cross each other, but extend in the first direction K1. Crossing each other only indirectly. Even in such a case, the shape retaining

long fibers

31 and 32 intersect each other only indirectly, so that a network structure capable of retaining the openings 41 to 44 can be formed. The shape-retaining

long fibers

33 and 34 located around the third and

fourth openings

43 and 44 also have the same form as the shape-retaining

long fibers

31 and 32.

6 (a) to 6 (e) are plan views showing still another example of a modified example of the absorber 13 according to the present invention. In the embodiment shown in FIG. 6A, the plurality of openings 40 are not arranged in the central portion 74 in the longitudinal direction Y and the lateral direction X of the absorber 13. In such an embodiment, for example, when the absorbent article is the sanitary napkin 10, the menstrual blood can be sufficiently and promptly provided by not arranging the plurality of openings 40 in the central portion 74 facing the vicinity of the wearer's vaginal opening. Can be absorbed into. In addition, in a region other than the central portion 74, the plurality of openings 40 are arranged, thereby exhibiting required air permeability and having appropriate followability to the wearer's body.

In the embodiment shown in FIG. 6 (b), a plurality of openings 40 are arranged only in the central portion 74 of the absorbent body 13 in the vertical direction Y and the horizontal direction X. In such an embodiment, for example, when the absorbent article is a disposable diaper, the body fluid is effectively spot-absorbed by absorbing the body fluid through the plurality of openings 40 arranged in the central portion 74. Can do.

In the embodiment shown in FIG. 6C, a plurality of openings 40 are arranged on the entire absorber 13, and the openings 40A having different sizes in each row 50 arranged in the first direction K1. , 40B are alternately arranged. In such an embodiment, the design of the absorber 13 is improved and the relatively small opening 40B is arranged as compared with the case where the opening 40 is composed of a plurality of openings having the same shape and the same size. Therefore, it is possible to suppress anxiety about the absorbability of the absorbent body 13 with respect to the wearer and / or the wear assistant.

In the embodiment shown in FIG. 6 (d), the plurality of openings 40 are not arranged in the entire area in the vertical direction Y dimension of the intermediate portion 75, which is the central portion of the absorbent body 13 in the horizontal direction X. In such an embodiment, the design is improved as compared with the case where the openings 40 are arranged in the entire absorber 13, and the plurality of openings 40 are arranged in the entire area in the longitudinal direction Y of the intermediate portion 75. By not being carried out, anxiety about the absorptivity of the absorber 13 can be suppressed with respect to a wearer and / or a wear assistant.

In the embodiment shown in FIG. 6E, the absorbent body 13 has an opening area 76 in which a plurality of openings 40 are arranged and a non-opening area 77 in which the plurality of openings 40 are not arranged. Alternatingly arranged in Y. In such an embodiment, the opening areas 76 and the non-opening areas 77 are alternately arranged in the longitudinal direction Y, so that a plurality of openings 40 are arranged at equal intervals throughout the absorber 13. The design is improved and the non-opening area 77 is positioned between them in the longitudinal direction Y while maintaining the required breathability and followability to the body of the absorber 13 by the plurality of opening areas 76. The absorber 13 has a required rigidity with respect to the lateral direction X, and the twisting at the time of wearing can be suppressed.

FIG. 7 shows an example of a usage example of the absorbent body 13 for absorbent articles according to the present invention. In this usage example, the absorbent body 13 is used in a disposable diaper (absorbent article) 80. ing. The disposable diaper 80 is shown in a state where the side seams joining both side edges of the front and

rear waist panels

84 and 85 are peeled off and extended in the horizontal and vertical directions.

The disposable diaper 80 has a front waist region 81, a rear waist region 82, and a crotch region 83 located between the front and

rear waist regions

81, 82. The diaper 80 includes a front waist panel 84 that defines a part of the front waist region 81 and the crotch region 83, a rear waist panel 85 that defines a part of the rear waist region 82 and the crotch region 83, and front and rear waists. A liquid absorbing structure 86 extending in the vertical direction on the skin facing surface side of the

panels

84 and 85, and arranged at intervals in the vertical direction in a state where both side edges of the front and

rear waist panels

84 and 85 are overlapped with each other. By being joined to each other via the plurality of seam portions 88, a waist opening and a pair of leg openings are defined. The absorber 13 extends from the crotch region 83 to the front and

rear waist regions

81 and 82 in the liquid absorbing structure 86.

The diaper 80 is a so-called pants type in which both side edges of the front and

rear waist regions

81 and 82 are joined in advance, and, like the sanitary napkin 10, the absorbent body 13 positioned in the crotch region 83 is worn in the wearing state. In addition, the SAP particles 26 that have absorbed the body fluid swell and gel and form a lump portion, and the shape of the opening 40 may be destroyed. By forming the structure, the opening 40 can be shaped and required air permeability and ease of deformation can be exhibited. In addition, as an absorbent article which concerns on this invention, not only a pants type diaper but an open type diaper may be sufficient.

Unless otherwise specified, the members constituting the

absorbent articles

10 and 80 are not limited to the materials described in the present specification, but may be any known materials that are commonly used in this type of field. Can be used. Further, terms such as “first”, “second”, “third”, and “fourth” used in this specification are simply used to distinguish similar elements, positions, and the like.

10 Sanitary napkins (absorbent articles)
20 Absorbent core 25 Water-absorbent fiber 26 Super absorbent polymer particles (SAP particles)
30 Long fiber 30a Part of long fiber 31 Long fiber for shape retention (first long fiber, second long fiber)
32 Long fibers for shape retention (first long fiber, second long fiber)
33 Long fibers for shape retention (first long fiber, second long fiber)
34 Long fibers for shape retention (first long fiber, second long fiber)
35 Long fibers for connection (third long fiber)
36 Linking long fibers (third long fibers)
37 Long fibers for connection (third long fibers)
40 opening part 41 1st opening part 42 2nd opening part 43 3rd opening part 44 4th opening part 71 Separation part 72 Separation part 80 Disposable diaper (absorbent article)
K1 first direction K2 second direction N1 virtual line (first virtual line)
N2 virtual line (second virtual line)
O1-O4 Opening center point X Horizontal direction Y Vertical direction

Claims

An absorbent for an absorbent article,
An absorbent core having a first surface and a second surface facing each other in the thickness direction; and a plurality of openings that penetrate the absorbent core in the thickness direction;
The absorbent core includes water-absorbing fibers and long fibers longer than the water-absorbing fibers,
The opening includes a first opening and a second opening arranged in the first direction with a space from the first opening;
The long fibers are at least one of the first surface and the second surface, the first long fibers located around the first opening, and the second long located around the second opening. With fibers,
The absorbent body, wherein the first long fiber and the second long fiber intersect each other directly or indirectly through another long fiber.
The first long fibers extend to the periphery of the second opening across a separation portion located between the first opening and the second opening, and the second long fibers are The absorbent body according to claim 1, extending across the spaced-apart portion to the periphery of the first opening.
The opening overlaps the second direction perpendicular to the first direction, the first imaginary line extending along the second direction overlapping the center of the first opening, and the center of the second opening. A second imaginary line extending along the second direction, and traverses the separated portion so that the first long fiber and the second long fiber intersect the first and second imaginary lines. The absorbent body according to claim 2.
4. The long fiber according to claim 1, further comprising a third long fiber extending in the first direction, wherein the third long fiber intersects with the first long fiber and the second long fiber. The absorber of description.
The absorbent according to any one of claims 1 to 4, wherein a part of the long fibers straddles the opening.
The absorbent according to any one of claims 1 to 5, wherein the long fibers are thermoplastic resin fibers and have an average fiber length of 6 to 70 mm.
The absorbent core further comprises a super absorbent polymer particles, the mass of the superabsorbent polymer particles, absorbent body according to any one of claims 1 to 6, which is 5 ~ 400g / m 2.
The area per one of the openings is 12 to 150 mm 2 , and the ratio of the total area of the plurality of openings to the area of the absorbent core is 1 to 50%. The absorber according to crab.
The absorber according to any one of claims 1 to 8, wherein the opening has a rectangular shape.
The absorber according to any one of claims 1 to 8, wherein the opening has a rhombus shape.
The absorbent according to any one of claims 1 to 10, wherein the long fibers are uniformly arranged in the entire absorbent core.
The absorbent according to any one of claims 1 to 10, wherein the long fibers are arranged denser in the opening edge of the opening than in other regions.