KR101913534B1 - Absorbent article - Google Patents

Abstract

There is provided an absorbent article having a longitudinal direction, a width direction and a thickness direction orthogonal to each other. The absorbent article includes an absorbent body including an absorbent core comprising liquid absorbent fibers. The absorbent body is provided along a longitudinal direction thereof with a folding line for guiding the absorbent body to bend and protrude toward the skin side in the thickness direction. Wherein the absorbent core has a low density portion which is formed at a position of the folding line in the width direction and in which the distribution density of the liquid absorbent fibers is lower than the distribution density of the surrounding portion; A skin side layer positioned on the skin side in the thickness direction with respect to the low density portion; And a non-skin side layer positioned on the non-skin side in the thickness direction with respect to the low density portion. And the liquid absorbent fiber exists in the low density portion. The skin side layer has a portion corresponding to the folding line, and the portion is bent so as to protrude toward the skin side in the thickness direction.

Description

Absorbent article

The present invention relates to an absorbent article such as a sanitary napkin.

BACKGROUND ART [0002] A sanitary napkin is known as an absorbent article that absorbs excreted liquid such as menstrual blood. Such napkins include longitudinal and transverse directions and thickness directions intersecting with each other. Further, each of these napkins includes an absorbent core comprising a liquid absorbent fiber as a main material between a liquid permeable top sheet and a liquid-pervious back sheet.

Patent Document 1: JP-A-2012-157459

An example of such a sanitary napkin includes a napkin 1 'which includes a folding line LB extending in the longitudinal direction and which is bent and protruded along the folding line LB toward the skin in the thickness direction. When the napkin 1 'is mounted on the groin 201K as shown in the schematic view of Fig. 1, the portion protruding toward the skin along the folding line LB is located at a position where the excretion hole 201He such as a vaginal opening is present You can touch the labia or get into the labia. As a result, good fit performance can be achieved.

However, in order to attach the sanitary napkin 1 'to the groin 201K, the undergarment (not shown) such as a panty is fixed to the groin 201K by disposing the sanitary napkin 1' The shape of the napkin 1 'may change to a shape different from the shape protruding toward the skin side as the case may be. Also, even when an external force toward the inside in the width direction, such as the crotch tightening force of the wearer 201, acts on the napkin 1 'during wear of the napkin 1', the shape of the napkin 1 ' There is a possibility that the shape protruding to the skin side is changed to a shape different from the shape protruding to the skin side.

When the shape is changed in this manner, the portion of the napkin 1 'protruding toward the skin side can not be properly brought into contact with the labia or between the labia, and as a result, the fit property is deteriorated.

On the other hand, in the case of the napkin 1 ', in addition to the aforementioned pit property, good absorbency of the excreted liquid is also required. That is, it is unacceptable to sacrifice the absorbency in order to improve the fitability.

The present invention has been made in view of the above problems, and an object of the present invention is to make it possible to stably maintain the shape of the absorbent article in a folded shape so that the absorbent article protrudes toward the skin along the folding line, .

The main aspect of the present invention to attain the above object is an absorbent article having a longitudinal direction, a width direction and a thickness direction orthogonal to each other,

An absorbent article comprising an absorbent body comprising an absorbent core comprising liquid absorbent fibers,

Wherein the absorbent body is provided with a folding line along the longitudinal direction to guide the absorbent body to bend and protrude toward the skin side in the thickness direction,

Wherein the absorbent core has a low density portion which is formed at a position of the folding line in the width direction and in which the distribution density of the liquid absorbent fibers is lower than a distribution density of surrounding portions and a low density portion which is formed on the skin side And a non-skin side layer positioned on the non-skin side in the thickness direction with respect to the low-density portion,

Wherein the liquid absorbent fiber is present in the low density portion,

Wherein the skin side layer has a portion corresponding to the folding line and the portion is bent so as to protrude toward the skin side in the thickness direction.

Other features of the present invention will become apparent from the following description with reference to the accompanying drawings.

According to the present invention, it is possible to stably maintain the shape of the absorbent article in a folded shape so that the absorbent article projects along the folding line to the skin side, and to exhibit good absorbency.

Fig. 1 is a schematic front view for explaining that the napkin 1 ', which can be bent so as to protrude toward the skin side in the thickness direction along the folding line LB, exhibits a good fitting property.
2 is a schematic plan view of the sanitary napkin 1 as an example of the absorbent article of the present embodiment viewed from the skin side in the thickness direction.
3 is a schematic plan view of the napkin 1 seen from its non-skin side in the thickness direction.
4 is a schematic exploded view taken along the line IV-IV in Fig.
5 is a schematic plan view of the absorber 10 viewed from the non-skin side in the thickness direction.
Fig. 6A is a schematic view showing the bending state of the absorber 10 taken along arrows VI-VI in Fig. 2. Fig.
Fig. 6B is a schematic view of the folded state of the napkin 1 taken along arrows VI-VI in Fig.
Fig. 7A is a schematic diagram of a cut surface cut along the width direction of the absorbent core 11, and is further a schematic view showing a portion corresponding to the folding line LB on the cut surface.
FIG. 7B is an electron micrograph of part B of FIG. 7A. FIG.
Fig. 8 shows Table 1 showing experimental data and results of obtaining a preferable range of the fiber density of the absorbent core 11. Fig.
Fig. 9 shows Table 2 showing experimental data and results for obtaining conditions under which the absorber 10 is held in the shape of a sharply folded line at the folding line LB.
10A is a schematic plan view of a test piece for measuring the bending resistance provided in this experiment.
FIG. 10B is an arrow mark taken along the line BB in FIG. 10A. FIG.
11A is a schematic front view of a test piece used to evaluate the maintenance stability of a mountain-folded shape.
Fig. 11B is a schematic front view of a copper specimen in which an acid-folded shape is roundly deformed by its own weight. Fig.

At least the following will become apparent from the description of the present specification and the accompanying drawings.

An absorbent article having a longitudinal direction, a width direction and a thickness direction orthogonal to each other,

Wherein the absorbent article comprises an absorbent body including an absorbent core comprising liquid absorbent fibers,

Wherein the absorbent body is provided with a folding line along the longitudinal direction to guide the absorbent body to bend and protrude toward the skin side in the thickness direction,

Wherein the absorbent core has a low density portion which is formed at a position of the folding line in the width direction and in which the distribution density of the liquid absorbent fibers is lower than a distribution density of surrounding portions and a low density portion which is formed on the skin side And a non-skin side layer positioned on the non-skin side in the thickness direction with respect to the low-density portion,

Wherein the liquid absorbent fiber is present in the low density portion,

Wherein the skin side layer has a portion corresponding to the folding line, and the portion is bent so as to protrude toward the skin side in the thickness direction.

According to such an absorbent article, the shape of the absorbent article can be stably maintained in a bent shape so that the absorbent article protrudes toward the skin along the folding line. The details are as follows. First, on the skin side layer of the absorbent core, a portion corresponding to the folding line is bent and protruded toward the skin side. Therefore, a folding phenomenon such as protruding to the skin side can be imparted to the absorbent article. And a low-density portion is located on the non-skin side of the skin side layer. Therefore, even when an external force toward the inside in the width direction, such as a crotch tightening force, acts on the article during wear of the absorbent article, the skin side layer can be made larger It can be bent. That is, when the skin side layer is more largely bent, the inner side portion of the skin side layer can quickly move toward the low density portion. Accordingly, when the skin side layer is further bent, the above-described inner side portion is displaced to avoid a situation in which a large resistance is exhibited. Thus, the shape of the absorbent article can be stably maintained in a bent shape so as to protrude toward the skin along the folding line.

The liquid-absorbent fiber exists in the low-density portion. As a result, the excreted liquid absorbed by the skin side layer can be drawn quickly toward the non-skin side layer. Thus, the absorbed excreted liquid can be rapidly diffused in the thickness direction. As a result, the absorbent article can exhibit good absorbency.

In such an absorbent article,

Wherein the non-skin side layer has, on the non-skin side layer, the respective portions located on both sides of the folding line protruding toward the skin in the thickness direction, and the portion located between the respective portions is protruded toward the non-skin side in the thickness direction And it is preferably bent in a shape of a letter.

According to such an absorbent article, even when an external force toward the inside in the width direction, such as a crotch tightening force, acts on the article during wear of the absorbent article, the non-skin side layer can be quickly And can be narrowly deformed in the width direction. Therefore, it is possible to reliably prevent the non-skin side layer from inhibiting the maintenance of the folded state of the skin side layer bent so as to protrude toward the skin side. Thus, the skin side layer can stably maintain the above-mentioned bent shape.

In such an absorbent article,

The average value of the fiber density of the liquid absorbent fiber of the absorbent core is preferably 0.092 (g / cm < 3 >) or more.

According to such an absorbent article, since the average value of the fiber density of the absorbent core is maintained at 0.092 (g / cm3) or more, it is possible to reliably form the low density portion by bending the core at the folding line .

In such an absorbent article,

It is preferable that the dimension of the skin side layer is larger than the dimension of the non skin side layer when the dimension in the thickness direction of the position corresponding to the folding line in the width direction is compared between the skin side layer and the non- .

According to such an absorbent article, the absorbable capacity of the excreted liquid is large in the skin side layer based on a large dimension in the thickness direction. Therefore, the excreted liquid such as menstrual discharge excreted from the excretion of the vaginal opening or the like can be quickly absorbed by the skin side layer and diffused into the surrounding portion of the non-skin side layer or the like. As a result, leakage of the excreted liquid from the absorbent article can be effectively prevented.

In such an absorbent article,

Said absorbent body comprising a skin side sheet secured to the skin side of said absorbent core,

The skin-side sheet is preferably integrally formed with the absorbent core and bent along the folding line.

According to this absorbent article, the above-described skin-side sheet is folded along the folding line integrally with the absorbent core. Therefore, the skin-side sheet can compensate the stiffness of the core so that the shape of the core is not collapsed, while preventing the maintenance of the folded state of the absorbent core. As a result, inadvertent deformation such as so-called warpage of the absorbent core can be effectively prevented.

In such an absorbent article,

Wherein the skin side sheet is a nonwoven fabric comprising thermoplastic resin fibers,

Wherein the absorbent core comprises a thermoplastic resin fiber and a cellulosic absorbent fiber as the liquid absorbent fiber,

It is preferable that the thermoplastic resin fibers of the skin side sheet and the thermoplastic resin fibers of the absorbent core are joined.

According to this absorbent article, the skin-side sheet includes thermoplastic resin fibers. The absorbent core also includes thermoplastic resin fibers. These thermoplastic resin fibers are bonded to each other. Here, these thermoplastic resin fibers are materials having similar properties. Therefore, these thermoplastic resin fibers can be strongly bonded by pressing or the like. Thus, the copper sheet is strongly bonded to the core. As a result, the copper sheet can more effectively supplement its rigidity so that the shape of the absorbent core is not collapsed.

In such an absorbent article,

When the lubrication degree is measured by the Gurley method defined in JIS L1085,

In the case where the absorbent body is bent so that a portion corresponding to the folding line protrudes toward the non-skin side in the thickness direction, when the absorbent body is bent so that a portion corresponding to the folding line protrudes toward the skin in the thickness direction It is preferable that the lattice constant is greater than 0.50 mN.

According to such an absorbent article, the lubrication degree in the case of bending the absorbent body to the opposite side is larger than 0.50 mN as compared with the lubrication when the absorbent body is bent so as to protrude toward the skin side. Therefore, the absorbent body is easily held in a sharply bent shape so as to protrude toward the skin along the folding line. As a result, the protruding portions are likely to come into contact with the labia in which vaginal discharge orifices are present or to enter between the labia.

In such an absorbent article,

It is preferable that the sheet which is subjected to the elongation treatment and in which the elasticity in the width direction is developed or the sheet in which the slit is formed along the longitudinal direction is arranged on the skin side in the thickness direction with respect to the absorbent core.

According to this absorbent article, the sheet disposed on the skin side of the absorbent core has good stretchability in the width direction. That is, in the case of the former sheet, stretchability is exhibited in the stretching process and exerts good extensibility. In the case of the latter sheet, good extensibility in the width direction is given based on the slit. Therefore, it is prevented that the sheet is inhibited from being bent so that the absorbent core projects along the folding line to the skin side. Accordingly, the shape of the absorbent article can be stably maintained in a bent shape so as to protrude toward the skin side.

In such an absorbent article,

The absorbent body and the top sheet disposed on the skin side in the thickness direction with respect to the absorbent body are joined and integrated by a plurality of compressed portions formed by compression from the skin side of the top sheet in the thickness direction,

It is preferable that a portion of the absorbent core of the absorbent core at which the folding line is not present has a portion where the crimping portion is not formed.

According to such an absorbent article, it is possible to suppress the bending rigidity of the folding line portion of the absorbent core from being raised by the above-mentioned crimping portion. Thus, it is difficult for the shape of the absorbent core to be bent so as to protrude toward the skin along the folding line. As a result, the bending shape can be stabilized.

In addition, the entrapment of the excreted liquid on the topsheet is enhanced. As a result, the topsheet can exhibit good liquid dropout.

In such an absorbent article,

It is preferable that no pressing portion is formed on the folding line of the absorbent core of the absorbent core.

According to such an absorbent article, it is possible to reliably prevent the bending rigidity of the folding line portion of the absorbent core from being increased by the above-mentioned crimping portion.

In such an absorbent article,

The folding line preferably extends along the entire length in the longitudinal direction of the absorbent core.

According to such an absorbent article, since the folding line extends along the entire length in the longitudinal direction of the absorbent core, the shape of the absorbent article is more stably maintained in a bent form so as to protrude toward the skin along the folding line It becomes possible.

In such an absorbent article,

A sheet is formed on the non-skin side of the non-skin side layer in the thickness direction, the sheet is integrally formed with the non-skin side layer and is bent in an M-

Wherein when the absorbent article is viewed from the non-skin side in the thickness direction, a valley-folding line at a position corresponding to the respective portions protruding toward the skin side in the non- And an acid-folding line is formed along the longitudinal direction at a position corresponding to the portion projecting toward the non-skin side.

According to this absorbent article, the above-described sheet is folded in an M-shape in unison with the non-skin side layer of the M-shape. Therefore, even when an external force such as a crotch tightening force toward the inside in the width direction acts on the absorbent article, the sheet can be contracted and deformed rapidly in the width direction together with the non-skin side layer. Thus, it is prevented that the maintenance of the state of the skin side layer that is bent so as to protrude toward the skin side is inhibited.

=== Embodiment Mode ===

Figs. 2 to 6B are explanatory views of the sanitary napkin 1 as an example of the absorbent article of the present embodiment. Fig. Fig. 2 is a schematic plan view of the sanitary napkin 1 viewed from the skin side in the thickness direction, and Fig. 3 is a schematic plan view of the napkin 1 seen from the non-skin side in the thickness direction. 4 is a schematic exploded view taken along the line IV-IV in Fig. 5 is a schematic plan view of the absorber 10 seen from its non-skin side in the thickness direction. 6A is a schematic view of the folding state of the absorber 10 taken along the arrow VI-VI in FIG. 2, FIG. 6B is a schematic view of the folding state of the napkin 1 taken along the arrow VI- to be.

As shown in Figs. 2 to 4, the napkin 1 is a vertically elongated sheet-shaped member in a plan view having a longitudinal direction, a width direction, and a thickness direction. In the napkin 1, the liquid-permeable top sheet 20, the liquid-absorbent absorbent 10, and the liquid-pervious back sheet 30 are arranged in this order from the skin side to the non-skin side in the thickness direction Respectively. These members 20, 10, and 30 are joined to each other by an adhesive (HMA) such as hot melt adhesive. Examples of the application pattern of the adhesive (HMA) include an Ω-type pattern, a spiral pattern, a stripe pattern, and the like, and the same applies to other adhesives (HMA) to be described hereinafter. In the following description, the direction corresponding to the back side of the wearer 201 along the longitudinal direction is referred to as "front side ", and the direction corresponding to the back side of the wearer 201 is also referred to as the " back side ".

2, the planar size of the topsheet 20 and the backsheet 30 is larger than the planar size of the absorber 10, as shown in Fig. The outer peripheral edge portions 20e and 30e of the both sheets 20 and 30 (see the dot-shaped portion in FIG. 2) are respectively projected outward in the longitudinal direction and outward in the width direction from the absorber 10 have. The outer circumferential edge portions 20e and 30e are bonded to each other by bonding or welding so that the absorbent body 10 is held between the both sheets 20 and 30.

In this example, the planar shapes of the both sheets 20 and 30 are the same. The protruding portions 20w and 30w are formed in such a manner that the napkin 1 is inserted into the undergarment (not shown) Called wing portions 1w and 1w which serve to arrange and fix the wing portions 1w and 1w. 3 and 4, on the non-skin side of each portion 30w of the back sheet 30 corresponding to the wing portion 1w, there is provided an adhesive portion for fixing the napkin 1 to the undergarment, For example, a substantially rectangular shape by an appropriate adhesive. The adhesive portion 40c for the purpose is also applied to the portion 30c between the wing portions 1w and 1w on the non-skin side of the back sheet 30 by a suitable adhesive, As shown in Fig. However, the arrangement pattern of the adhesive portions 40w and 40c is not limited to the above.

An example of the material of the topsheet 20 is an appropriate nonwoven fabric such as an air-through nonwoven fabric. In this example, an air-through nonwoven fabric is used. However, the material is not limited thereto. That is, any liquid-permeable flexible sheet may be used. An example of the material of the back sheet 30 is an appropriate resin film such as polyethylene (PE). In this example, a PE film is used. However, the material is not limited thereto. That is, any other sheet may be used as long as it is a fluid-permeable flexible sheet.

2, a plurality of pressed portions E, E, ... are formed from the skin side on the skin side surface of the topsheet 20, so that the topsheet 20 and the absorbent body 10, Are pressed together in the thickness direction and joined together. In this example, as the crimping portion E, two kinds of crimping portions EL and ED are formed. The one pressing portion (E) is a linear pressing portion (EL). These linear bonding portions EL, EL, ... are formed continuously along the outer peripheral edge portion of the absorber 10, and as a whole, are substantially annular in the longitudinal direction. On the other hand, the other crimping portion E is a pointed crimping portion ED. These pointed portions ED, ED ... are arranged in a substantially closed area AEL in which the plurality of linear pressing portions EL, EL ... are separated on the topsheet 20, Respectively. In this example, the planar shapes of the pressure bonding portions ED on the respective points are circular with a diameter of 1 mm, and these pressure bonding portions ED, ED... Are arranged in a staggered arrangement pattern, but are not limited thereto. Further, the pressure bonding portions ED and the linear pressure bonding portions EL on these points may be omitted.

As shown in Fig. 5, the absorbent core 10 includes an absorbent core 11 formed by shaping a liquid absorbent fiber or the like into a vertically elongated shape as seen in a long plane in a longitudinal direction as an example of a predetermined shape, A skin side sheet 12 having a substantially planar shape in plan view so as to cover the side surface of the skin; a skin side sheet 12 having substantially the same planar shape as the core core 11 so as to cover the core 11 from the non- And a skin side sheet (13). 4, the sheets 12 and 13 are bonded and integrated to the absorbent core 11 by an adhesive agent (HMA) such as a hot-melt adhesive agent, So that the absorbent core 11 is prevented from being inadvertently deformed, such as wrinkles or warps.

The absorbent core 11 includes cellulose-based water absorbent fibers and thermoplastic resin fibers as liquid absorbent fibers in a range of, for example, a basis weight 100 (g / m2) to 400 (g / m2) . In this example, pulp fiber is used as an example of the former, and as an example of the latter, a composite fiber of so-called super structure in which the sheath is made of polyethylene (PE) and the core is made of polyethylene terephthalate (PET) Is used in a fiber length of 30 mm, but is not limited thereto. For example, rayon fibers may be used as the former, and the latter may be made of single fibers of polyethylene (PP) or single fibers of PE. Further, the latter thermoplastic resin fiber may be omitted.

In this example, in addition to the liquid absorbent fibers, the core 11 is made of a super absorbent polymer (so-called SAP, for example) having a basis weight of 5 (g / m2) to 50 ), But this SAP is also optional.

In this example, an air through nonwoven fabric having a basis weight in the range of 10 (g / m 2) to 70 (g / m 2) is used as the skin side sheet 12, Do not. That is, other types of nonwoven fabric may be used, or tissue paper or the like may be used, and furthermore, the skin side sheet 12 may be omitted. Spunbond / meltblown / spunbond (SMS) nonwoven fabric having a basis weight in the range of 10 (g / m2) to 50 (g / m2) is used as the non-skin side sheet 13, It is not limited. That is, other types of nonwoven fabric may be used, or tissue paper or the like may be used, and further, the same non-skin side sheet 13 may be omitted.

As shown in Fig. 5, in this absorber 10, a pointed compression bonding portion ED10 is also pressed and formed from the non-skin side. That is, in this example, since the absorbent body 10 includes the skin side sheet 12, the absorbent core 11, and the non-skin side sheet 13, these three members are pressed together in the thickness direction, And a portion ED10 is formed. As a result, rigidity is increased, and as a result, inadvertent deformation such as wrinkles can be suppressed. In this example, the flattened shape of the crimping portion ED10 is circular with a diameter of 1.2 mm, and these crimping portions ED10, ED10, ... are arranged in a staggered arrangement pattern, but are not limited thereto. The maximum value of the thickness of the absorber 10 in which the pressed portion ED10 and the pressed portion EL are formed is within a range of, for example, 0.5 mm to 5 mm, but is not limited thereto.

On the other hand, as shown in Figs. 5 and 6A, a folding line LB is formed along the entire length of the copper absorbing body 10 in a straight line along the longitudinal direction at a central position in the width direction, Thus, as shown in Fig. 6A, the copper absorbent 10 is bent so as to protrude along the folding line LB toward the skin in the thickness direction. As a result, as shown in Fig. 6B, the napkin 1 is also guided so that the central position in the width direction is bent toward the skin and protruded. 1, in order for the wearer 201 to attach the napkin 1 to the napkin 201K, a panty (not shown) in which the napkin 1 is placed and fixed to the crotch portion is inserted into the napkin 201 201K, the above-mentioned portion protruding toward the skin side comes into contact with the labia in which the excretion 201He such as the vaginal opening is present or between the labia. Thus, the napkin 1 can exhibit a good fitability.

However, as described in the beginning, such a shape in which the central position in the width direction protrudes toward the skin can be changed during the lifting process of the pant or the wearing of the napkin 1, and when the shape is changed, 1) is difficult to contact with the labia, or is difficult to enter between the labia, and as a result, the fitability deteriorates.

Thus, in the present embodiment, such a shape that is bent so as to protrude toward the skin side is designed to be stably maintained. Hereinafter, this invention will be described.

7A is a schematic diagram of a cut surface cut along the width direction of the absorbent core 11, and further a schematic enlarged view of a portion corresponding to the folding line LB in the cut surface. FIG. 7B is an electron micrograph of part B of FIG. 7A. FIG. The schematic view of Fig. 7A and the electron micrograph of Fig. 7B show that the dimension in the width direction is slightly narrower than that in a normal state to slightly increase the bending state for the purpose of making the design easier to see.

First, the absorbent core 11 is bent so as to protrude toward the skin in the thickness direction along the folding line LB extending straight in the longitudinal direction as described above. Here, the distribution density (g / cm 3) (hereinafter also referred to as fiber density (g / cm 3)) of the liquid absorbent fibers is set around the core 11 at the position of the folding line LB in the width direction Density portion 11DL which is lower than that of the portion of the lower density portion 11DL. The core 11 includes a skin side layer 11s which is located on the skin side of the low density portion 11DL and has a higher fiber density than the low density portion 11DL and a skin side layer 11s which is located on the skin side of the low density portion 11DL, (11 ns) having a fiber density higher than that of the non-skin side layer (11 ns).

The skin side layer 11s is folded so that the portion 11sLB corresponding to the folding line LB protrudes toward the skin side. 6B). Thus, even when the panty is lifted, the napkin 1 can be prevented from being folded back to the napkin 1 (see Fig. 6B) 1 is likely to be held in a protruding shape toward the skin side.

On the non-skin side of the skin side layer 11s, a low density portion 11DL is located. Therefore, even when external force toward the inside in the width direction such as a crotch tightening force acts on the napkin 1 while the napkin 1 is worn, the skin side layer 11s can be prevented from being bent It can be quickly and more largely bent while maintaining the shape. That is, when the skin side layer 11s is further bent, as shown in Fig. 7A, the inner side portion 11sp of the skin side layer 11s can quickly move toward the low density portion 11DL. As a result, when the skin side layer 11s is further bent, the inner side portion 11sp is displaced to avoid a situation in which a large resistance is exhibited. Therefore, the shape of the napkin 1 can be stably maintained in a bent shape so as to protrude toward the skin along the folding line LB.

On the other hand, as shown in Fig. 7B, in the low density portion 11DL, the amount of the liquid absorbing fiber is smaller than that in the surrounding portion. Therefore, the excreted liquid absorbed by the skin side layer 11s can be drawn quickly toward the non-skin side layer 11ns. Thus, the absorbed excreted liquid can be rapidly diffused in the thickness direction. As a result, the napkin 1 can exhibit good absorbency.

It is preferable that the dimension in the thickness direction of the skin side layer 11s at the position corresponding to the folding line LB is in the range of 0.3 mm to 3 mm in view of ensuring the above- And the maximum value of the dimension in the thickness direction of the low density portion 11DL and the maximum dimension in the width direction are preferably in the range of 0.3 mm to 3.5 mm and 0.5 mm to 5 mm, .

The confirmation that the fiber density (g / cm 3) of the low density portion 11DL is lower than the fiber density (g / cm 3) of the portion around the low density portion 11DL can be confirmed by cutting the absorbent core 11 along the width direction , And the cut surface is colored with ink to make the liquid absorbent fiber visible. That is, by making the gap between the fibers and the fibers clearly visible as shown in FIG. 7B by the above-described dyeing treatment, the fiber density of the low density portion 11DL is lower than the fiber density of the surrounding portion, .

If such visual confirmation is difficult, the following may be used. First, for example, the number of liquid absorbent fibers located in the region A11DL (hereinafter also referred to as a low density portion assumed region A11DL) assumed to be the low density portion 11DL is counted to determine the total length of the liquid absorbent fibers . Similarly, for example, the total number of the liquid absorbent fibers located at the periphery of the low density partial assumed area A11DL is counted to obtain the total length. Then, multiplication values are obtained by multiplying the sum of the obtained lengths by the specific gravity of the liquid-absorbent fibers and the cross-sectional area of the fiber, respectively. Thereafter, each multiplication value is divided by the corresponding volume of each of the regions, and divided values are respectively obtained. As a result, the fiber density (g / cm3) of the low density partly assumed area A11DL and the fiber density (g / cm3) of the surrounding area can be obtained. As a result, it can be confirmed whether or not the low density portion assumed region A11DL is actually the low density portion 11DL.

On the other hand, as shown in Fig. 7A, in this example, the non-skin side layer 11ns is bent in an M-shape. That is, the portions 11nsp and 11nsp located on both sides in the width direction of the folding line LB in the non-skin side layer 11ns protrude toward the skin side, and the portions 11nsp and 11nsp located between the respective portions 11nsp and 11nsp Skin side layer 11ns is bent such that the portion 11nspm protrudes toward the non-skin side. Therefore, even when an external force toward the inside in the width direction such as a crotch tightening force acts on the napkin 1 while the napkin 1 is worn, the above-mentioned non-skin side layer 11ns has the above- It can be quickly deformed in the width direction. Therefore, the state of the skin side layer 11s bent to protrude toward the skin side is surely prevented from being inhibited by the non-skin side layer 11ns. As a result, the skin side layer 11s can stably maintain the above-mentioned bent shape. However, it is not limited thereto. That is, the non-skin side layer 11ns may not be bent in an M-shape.

In this example, when the dimension in the thickness direction of the position corresponding to the folding line LB in the width direction is compared between the skin side layer 11s and the non-skin side layer 11ns, the dimension L11s ) Is larger than the dimension (L11ns) of the non-skin side layer (11ns). Based on the fact that such a dimension L11s in the thickness direction is large, the absorbable capacity of the excreted liquid is large in the skin side layer 11s. Therefore, the excretion liquid such as menstrual discharge excreted from the vaginal opening 201He of the vaginal opening or the like quickly and immediately absorbs the large amount of absorbable capacity of the skin side layer 11s, As shown in FIG. As a result, the napkin 1 can exhibit a high absorbency immediately, thereby effectively preventing the leakage of the excreted liquid from the napkin 1. However, it is not limited thereto. That is, in the dimension in the thickness direction, the dimension L11ns of the non-skin side layer 11ns may be larger than the dimension L11s of the skin side layer 11s.

In this example, the skin side sheet 12 of Fig. 4 fixed to the skin side of the absorbent core 11 is integrated with the absorbent core 11 by the above-mentioned adhesive (HMA) or the like. Thus, the skin-side sheet 12 is integrated with the core 11 and bent along the folding line LB. Therefore, the copper sheet 12 can compensate the rigidity of the core 11 so that the shape of the core 11 is not collapsed, while preventing the absorbent core 11 from being held in the folded state. As a result, inadvertent deformation such as wrinkles of the absorbent core 11 can be effectively prevented. However, it is not limited thereto. In other words, the skin-side sheet 12 may not be integral with the absorbent core 11.

The skin-side sheet 12 is an air-through nonwoven fabric as described above, and includes thermoplastic resin fibers as constituent fibers. On the other hand, the absorbent core 11 also includes thermoplastic resin fibers. The thermoplastic resin fibers are thermally fused to each other by being pressed together with the above-mentioned crimping portions (EL, ED, and ED10) in that they are materials having similar properties. As a result, the skin-side sheet 12 is firmly bonded to the absorbent core 11. Therefore, the skin-side sheet 12 can effectively exert a reinforcing action for supplementing the rigidity of the absorbent core 11 described above. However, it is not limited thereto. That is, the skin side sheet 12 may not contain thermoplastic resin fibers. The absorbent core 11 may also not contain thermoplastic resin fibers.

In this example, the non-skin side sheet 13 and the back sheet 30 are formed on the non-skin side of the absorbent core 11 as shown in Fig. These sheets 13 and 30 are adhered and fixed integrally to the non-skin side layer 11ns (Fig. 7A) of the core 11 by the above-mentioned adhesive (HMA). Accordingly, these sheets 13, 30 are also integrated with the non-skin side layer 11ns and bent in an M-shape. Therefore, when external force toward the inside in the width direction such as the crotch tightening force acts on the napkin 1, these sheets 13 and 30 can also be contracted and deformed rapidly in the width direction together with the non-skin side layer 11ns . Thus, it is prevented that the folded state of the skin side layer 11s bent to protrude toward the skin side is inhibited. However, it is not limited thereto. That is, the non-skin side sheet 13 and the back sheet 30 may not be integrated with the non-skin side layer 11ns of the absorbent core 11. [

With respect to the M shape of the back sheet 30, the napkin 1 can be easily seen from the non-skin side. 7A, at the respective positions on the back sheet 30 corresponding to the portions 11nsp and 11nsp projecting to the skin side in the non-skin side layer 11ns, as shown in Fig. 3, Folding lines Lv and Lv are formed along the longitudinal direction. On the other hand, an acid-folding line Lm is formed along the longitudinal direction at a position on the back sheet 30 corresponding to the portion 11nspm projecting toward the non-skin side. Therefore, it can be easily confirmed that the back sheet 30 is folded in an M-shape by looking at these bone-fold lines Lv and Lv and the acid-fold line Lm.

2, in this example, the pointed crimping portions (ED, ED, ...) for pressing and bonding the topsheet 20 and the absorbent body 10 from the skin side together are integrally formed as a zigzag arrangement pattern Respectively. Here, as in the example of Fig. 2, it is preferable that these pressed portions ED, ED ... are not formed on the folding line LB of the absorbent core 11.

In this case, it is possible to prevent the bending rigidity of the portion of the folding line LB from being increased due to the pressed portions ED, ED .... Therefore, the shape of the absorbent core 11 is not inhibited from being bent to protrude toward the skin along the folding line LB. As a result, the bending shape can be stabilized.

However, it is not limited thereto. That is, unless the pressed portion ED is formed on at least a part of the folding line LB of the absorbent core 11, the above-described inhibition effect can be correspondingly enjoyed. Therefore, it suffices that there is a portion where the crimping portion ED is not formed in the portion of the folding line LB in the absorbent core 11.

In view of the prevention of the above-described inhibition, it is preferable that the skin side sheet 12 or the top sheet 20 in the example of Fig. 4, which is located on the skin side in the thickness direction with respect to the absorbent core 11, It is sufficient if it has high elongation in the width direction. In this case, these sheets 12 and 20 do not inhibit the absorbent core 11 from being bent so as to protrude toward the skin along the folding line LB. As a result, the shape of the napkin 1 can be stably maintained in a bent shape so as to protrude toward the skin side. As the sheet having a high elongation in the width direction, there can be used a sheet having stretchability in the width direction by stretching treatment such as a so-called gear stretching treatment or a sheet having one slit along the longitudinal direction or a sheet having a plurality of slits And sheets formed side by side in the width direction. Examples of the material of the former sheet (stretchable and stretchable sheet) include an elastomer, such as a polyurethane-based elastomer, exhibiting substantially elasticity, and a sheet containing a thermoplastic resin exhibiting substantially inelasticity such as a polyolefin- have.

When the absorbent core 11 is bent so as to protrude toward the skin side, the non-skin side sheet 13 is not stretched generally in the width direction. Therefore, as the non-skin-side sheet 13, a sheet having lower stretchability than the skin-side sheet 12 can be used. For example, in this example, an air through nonwoven fabric is used for the skin side sheet 12 and an SMS nonwoven fabric is used for the non-skin side sheet 13. [ This is because the air through nonwoven fabric has a higher elongation in the width direction than the SMS nonwoven fabric. And a similar way of thinking can be extended to the topsheet 10 or the backsheet 30. That is, the stretchability of the non-skin-side sheet 13 or the back sheet 30 can be lower than the stretchability of the skin-side sheet 12 or the topsheet 10. As used herein, extensibility means a property of being stretched without being broken when stretched by 5% of the natural length in a predetermined direction. It is preferable that the load at 25 mm width when stretched by 5% is 10 N / 25 mm or less.

In order to form a low density portion 11DL inside the absorbent core 11 and to form a folded shape so as to project the skin side layer 11s of the core 11 to the skin side, The folding line LB thus formed can be formed, for example, as follows.

First, the absorbent body 10 on which the compression bonding portion ED10 is formed is folded in two in the width direction while overlapping the portions facing each other in the thickness direction so that the skin side becomes the outer peripheral side. Then, by moving the copper absorbing body 10 between the pair of upper and lower press rollers in a state of being folded in two, the absorber 10 folded in two by the press rollers is pressed in the thickness direction. After the pressing, the folded line LB is formed along the longitudinal direction at the center position in the width direction when the folded state of the absorbent body 10 in the folded state is released in the width direction and the folded state of the absorbent body 10 is released . At the portion between the skin side layer 11s and the non-skin side layer 11ns of the absorbent core 11, peeling or the like occurs. As a result, the low density portion 11DL is formed in the portion and the shape projecting to the skin side remains in the skin side layer 11s. Thus, the folding line LB on which the above two designs are made is formed on the absorber 10.

In the manufacturing process of the absorber 10, basically, the absorber 10 is in the state of a continuum continuing in the longitudinal direction, and the press process described above is also performed on the continuum of the absorber 10. Therefore, the press processing can be continuously performed, and as a result, the absorber 10 can be manufactured with high productivity.

Here, the average value of the fiber density of the absorbent core 11 is preferably 0.092 (g / cm < 3 >) or more in view of reliably performing the formation of the low density portion 11DL. Here, the numerical range of 0.092 (g / cm < 3 >) or more is obtained by experiments. Hereinafter, this experiment will be described.

First, the absorbent core 11 to be a test piece was prepared with the composition shown in Table 1 in Fig. That is, the absorbent core (20 g / m < 2 >) in which the composite fibers of the core structure of 200 (g / m 2) pulp fibers and the PE (sheathed) / PET (11). The absorbent core 11 made of only pulp fibers was prepared at two levels of 200 (g / m 2) and 400 (g / m 2). With regard to the fiber density (g / cm 3), for example, a plurality of pressed portions are discretely formed on each of the above-described absorbent core 11 and the thickness thereof is adjusted to each value in Table 1, . After the test pieces thus obtained are folded in two, the test piece is opened up to 90 DEG, and the presence or absence of the low density portion 11DL of the absorbent core 11 is visually determined.

The calculation of the fiber density (g / cm 3) in the case where the test piece contains the pulp fiber and the composite fiber is carried out by dividing the sum of the basis weights (g / m 2) of the pulp fiber and the composite fiber by the thickness I do. On the other hand, the calculation of the fiber density (g / cm 3) when the test piece contains only the pulp fiber is performed by dividing the basis weight (g / m 2) of the pulp fiber by the thickness (mm) of the test piece.

In Table 1, the naked eye determination result with or without the low density portion 11DL is shown in correspondence with the fiber density (g / cm 3). From this, it can be seen that when the fiber density is 0.092 (g / cm3) or more, the low density portion 11DL is formed. Therefore, from the viewpoint of reliably forming the low density portion 11DL, the fiber density of the absorbent core 11 is preferably 0.092 (g / cm < 3 >) or more.

Preferably, the average fiber density of the core 11 is 0.6 (g / cm3) or less, and more preferably 0.5 (g / cm3) or less. If this is done, there is a problem that may arise when the average fiber density of the core 11 changes more than 0.6 (g / cm 3), that is, the core 11 is excessively stiff Deterioration of the mounting feeling of the napkin 1 can be effectively prevented.

If the absorbent body 10 is easily held in a sharply folded shape at the folding line LB, the portion projecting to the skin side is contacted to the labia on which the vaginal opening 201He exists Or it is easy to enter between the labia.

Therefore, the present inventor has studied a condition for easily maintaining a shape that is sharply bent so as to protrude toward the skin along the folding line LB. This will be described below.

First, from the results, in order to easily maintain the shape that is sharply bent so as to protrude to the skin side, when the bending rigidity of the absorbent article 10 is measured by the lengthening method according to JIS L1085, LB of the absorbent body 10 is projected toward the non-skin side so that the portion corresponding to the folding line LB protrudes toward the non-skin side, as compared with the case where the absorbent body 10 is folded in the acid- The degree of laminating in the case of folding with folding may be made to be 0.50 mN or more. Here, a numerical range of 0.50 mN or more is obtained by experiments. This experiment will be described below.

First, a plurality of samples made of pulp fibers simulating the absorber 10 were produced at a plurality of basis weights as shown in Table 2 in Fig. A plurality of pointed crimping portions were discretely formed in each sample to keep the thickness of all the samples in the range of 1.3 to 1.75 mm, thereby matching the thicknesses of the samples to substantially the same value. Further, folding lines LB were formed along the longitudinal direction at the same position by bending the samples at the respective weighing levels at the central position in the width direction. Then, a test piece was cut out from the sample having the folding line LB formed into a rectangular shape of 38 mm in length × 25 mm in width.

Fig. 10A shows a schematic plan view of the test piece, and Fig. 10B shows an arrow mark taken along the line B-B in Fig. 10A. 10A and 10B, when cutting the test piece, the longitudinal direction in the direction of the 38 mm length is made to follow the width direction of the sample, while the lateral direction in the direction of the 25 mm length is the length of the sample I followed directions. Here, the width direction of the sample coincides with the width direction of the napkin 1, and the longitudinal direction of the sample coincides with the longitudinal direction of the napkin 1.

At the position of 11 mm from the upper end in the longitudinal direction of the test piece, the test piece was cut so that the folding line LB described above was located along the lateral direction. In order to prevent the distortion of the test piece, an acrylic adhesive tape having a thickness of 48 占 퐉 was attached to the skin side surface and the non-skin side surface of the upper end portion in the longitudinal direction of the test piece. In order to prevent the adhesive tape from affecting the measurement accuracy of the lubrication degree, the adhesive tape is applied to the portion of the test piece in such a manner as not to be projected downward from the chuck of the grip type flexibility tester described later It was a verb.

The measurement of the acid-folding and bone-folding laminates of the test pieces was carried out using a Jelly type flexibility tester (manufactured by Yasuda Seiki KK) capable of performing the Jurassic method of JIS L1085. The measuring procedure was in accordance with JIS L1085. In the measurement, the upper end portion of the test piece in the longitudinal direction was fixed to the chuck of the movable arm of the tester with a length of 6.3 mm in the longitudinal direction, and the lower end portion of the test piece was fixed to the upper end of the pendulum of the tester Lt; / RTI > Then, the movable arm was moved so as to bend the test piece in the thickness direction, and the scale of the pendulum position at the time when the lower end portion of the test piece fell from the upper end portion of the pendulum was read. The measurement of the degree of lubrication was carried out five times for each level of the basis weight, and the average value of the five measurements was the lecture level of each level.

Evaluation was made as to whether or not each sample of each basis weight was easy to hold in an acid-folded shape that was sharply bent so as to protrude to the skin side.

First, 5 or 10 pieces were cut out from each sample of the basis weight level at which the folding line LB was formed in a rectangular shape of 65 mm in the width direction and 30 mm in the longitudinal direction to evaluate the maintenance stability of the bent shape A specimen was produced. At the time of cutting, the folding line LB was located at the center position of the 65 mm length.

As shown in Fig. 11A, each test piece was bent at the folding line LB to form an acid-folded shape which was bent so as to protrude toward the skin side. At this time, the distance between the pair of slopes in the acid-folded shape was adjusted to be 40 mm at the lower end thereof. The pair of slopes was fixed on the above-mentioned horizontal table surface while keeping the interval between the lower ends at 40 mm as described above.

Then, as shown in Fig. 11B, the acid-folded shape of the test piece is rounded by the weight of the test piece. The degree of rounding was visually confirmed by ten judges, and it was judged whether or not the acid-folded shape of the test piece was sharp for each basis weight, and a final judgment was made by majority vote of these judgment results.

The experimental results are shown in Table 2 in Fig. From this, it can be seen that when the subtraction value of the acid-folded lattice diagram from the bone-folded lattice diagram is 0.50 mN or more, the acid-folded structure is easily maintained in a sharp folded shape. Therefore, in order to make it easier to hold the absorbent body 10 in the sharp folded shape, the absorbent body 10 is formed so as to protrude toward the non-skin side rather than the liner of the case where the absorbent body 10 is acid- It was found that the degree of lapping in the case of bone-folding should be increased by 0.50 mN or more.

=== Other Embodiments ===

Although the embodiment of the present invention has been described above, the embodiment described above is for facilitating understanding of the present invention, and is not for limiting the present invention. Further, the present invention can be changed or improved without departing from the gist, and it goes without saying that the present invention includes its equivalents. For example, the following modifications are possible.

In the above-described embodiment, the sanitary napkin 1 is exemplified as the absorbent article, but it is not limited thereto at all. For example, the absorbent article may be a panty liner.

In the above-described embodiment, the sanitary napkin 1 as an example of the absorbent article includes the pair of wing portions 1w and 1w, but is not limited thereto. That is, the wing portion 1w may be omitted.

In the above-described embodiment, the folding line LB is formed at the center position in the width direction of the absorbent core 11, but the present invention is not limited to this. That is, the folding line LB may be formed at a position slightly shifted from the center position in the width direction. However, the absorbent core 11 and the napkin 1 are preferably formed symmetrically with respect to the center position in the width direction, so that the folding line LB is preferably formed at the center position.

In the above-described embodiment, the absorbent core 11 is covered with the two sheets of the skin side sheet 12 and the non-skin side sheet 13, but is not limited thereto. For example, the skin side surface and the non-skin side surface of the absorbent core 11 may be covered with a single sheet.

In the above-described embodiment, the folding line LB is formed along the entire length in the longitudinal direction of the absorber 10, but is not limited thereto. That is, the folding line LB may be formed in a part of the longitudinal direction of the absorbent body 10, as long as the absorbent body 10 is bent and projected toward the skin side by the folding line LB. For example, the folding line LB may be formed only in the excretion opening opposing region where the excretion hole 201He such as a vaginal opening is opposed to the absorber 10 in the absorber 10.

11: absorbent core, 11: absorbent core, 11DL: low density portion, 11s: skin side layer, 11sLB: portion corresponding to folding line, 11sp: inner side portion, 11ns The present invention relates to a non-skin side sheet, a non-skin side sheet, a non-skin side layer, a non-skin side layer, A: area A11DL: low-density part assumed area, E: pressed part, EL: line-up part, 40c: adhesive part, 40w: adhesive part, 201: wearer, 201K: grout, 201He: excretion hole, LB: folding line, Folded line, Lm: folded line, Lm: folded line, ED: pointed bonded part, ED10: pressed part, LKs: cut line, Lkns: cut line, HMA:

Claims (12)

An absorbent article having a longitudinal direction, a width direction and a thickness direction orthogonal to each other,
Wherein the absorbent article comprises an absorbent body including an absorbent core comprising liquid absorbent fibers,
Wherein the absorbent body is provided with a folding line along the longitudinal direction to guide the absorbent body to bend and protrude toward the skin side in the thickness direction,
Wherein the absorbent core has a low density portion which is formed at a position of the folding line in the width direction and in which the distribution density of the liquid absorbent fibers is lower than a distribution density of surrounding portions and a low density portion which is formed on the skin side And a non-skin side layer positioned on the non-skin side in the thickness direction with respect to the low-density portion,
Wherein the liquid absorbent fiber is present in the low density portion,
Wherein the skin side layer has a portion corresponding to the folding line, and the portion is bent so as to protrude toward the skin side in the thickness direction. The method according to claim 1,
Wherein the non-skin side layer has, on the non-skin side layer, the respective portions located on both sides of the folding line protruding toward the skin in the thickness direction, and the portion located between the respective portions is protruded toward the non-skin side in the thickness direction Wherein the absorbent article is folded in a shape of a letter. 3. The method according to claim 1 or 2,
Wherein the average value of the fiber density of the liquid absorbent fibers of the absorbent core is 0.092 (g / cm < 3 >) or more. The method according to claim 1,
Side layer and the non-skin side layer, the dimension in the thickness direction of the position corresponding to the folding line in the width direction is compared with the dimension in the skin side layer and the non-skin side layer, article. The method according to claim 1,
Said absorbent body comprising a skin side sheet secured to the skin side of said absorbent core,
Wherein the skin-side sheet is integrally formed with the absorbent core and is folded along the folding line. 6. The method of claim 5,
Wherein the skin side sheet is a nonwoven fabric comprising thermoplastic resin fibers,
Wherein the absorbent core comprises thermoplastic resin fibers and cellulose-based absorbent fibers as the liquid absorbent fibers,
Wherein the thermoplastic resin fibers of the skin side sheet and the thermoplastic resin fibers of the absorbent core are bonded. The method according to claim 1,
When the lubrication degree is measured by the Gurley method defined in JIS L1085,
In the case where the absorbent body is bent so that a portion corresponding to the folding line protrudes toward the non-skin side in the thickness direction, when the absorbent body is bent so that a portion corresponding to the folding line protrudes toward the skin in the thickness direction Absorbent article is larger than the lattice degree by at least 0.50 mN. The method according to claim 1,
Wherein the stretchable sheet and the stretchable sheet in the width direction or the sheet in which the slit is formed along the longitudinal direction are arranged on the skin side in the thickness direction with respect to the absorbent core. The method according to claim 1,
The absorbent body and the top sheet disposed on the skin side in the thickness direction with respect to the absorbent body are joined and integrated by a plurality of compressed portions formed by compression from the skin side of the top sheet in the thickness direction,
Wherein the absorbent core of the absorbent core has a portion where the crimping portion is not formed at a portion of the folding line. 10. The method of claim 9,
Wherein no pressing portion is formed on a portion of the folding line of the absorbent core of the absorbent core. The method according to claim 1,
Wherein the folding line extends along the entire length in the longitudinal direction of the absorbent core. 3. The method of claim 2,
A sheet is formed on the non-skin side of the non-skin side layer in the thickness direction, and the sheet is folded in an M-shape integrally with the non-skin side layer,
Wherein when the absorbent article is viewed from the non-skin side in the thickness direction, a valley-folding line at a position corresponding to the respective portions protruding toward the skin side in the non- And a mountain-folding line is formed along the longitudinal direction at a position corresponding to the portion projecting toward the non-skin side.

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