JP7325179B2 - absorbent article - Google Patents

Description

The present invention relates to absorbent articles.

Sheets containing water-retentive fibers that absorb and retain water, such as cotton fibers, are known as topsheets of absorbent articles.

For example, Patent Literature 1 discloses a fibrous sheet containing cotton fibers, which is used as a topsheet. This fiber sheet includes a cotton fiber layer and a nonwoven fabric made of synthetic fibers, and the cotton fiber layer is held in a state in which it is partially embedded in the nonwoven fabric.

Japanese Patent Application Laid-Open No. 2004-324038

However, since the absorbent article using the fiber sheet described in Patent Document 1 uses water-retaining fibers in the surface sheet, it has a good texture and quickly absorbs body fluids adhering to the skin, but the water-retaining fibers However, when a load such as body weight is applied to the topsheet, the body fluid retained in the absorbent body may return to the skin side of the topsheet and cause discomfort to the wearer.
In addition, since the water-retentive fiber retains body fluids at a temperature close to body temperature, there is a risk that germs will easily propagate.

Accordingly, it is an object of the present invention to provide an absorbent article that is excellent in anti-rewet performance and antibacterial properties while maintaining good touch and bodily fluid absorbency of a surface sheet made of water-retentive fibers.

The inventors of the present invention have conducted intensive research in view of the above problems. As a result, the topsheet has two fiber layers containing water-retaining fibers, and the content of the polymer phenol compound in the water-retaining fibers in the fiber layer located on the non-skin side of the topsheet is the same as that on the skin side of the topsheet. The present inventors have found that the above problems can be solved by an absorbent article in which the content of the high-molecular-weight phenolic compound in the water-retentive fibers in the fiber layer is large, and have completed the present invention. Specifically, the present invention provides the following.

The present invention is an absorbent article comprising a topsheet having a skin side and a non-skin side, a backsheet, and an absorbent body positioned between the topsheet and the backsheet, wherein the topsheet comprises: A first fiber layer that constitutes the skin side, and a second fiber layer that is adjacent to the non-skin side of the first fiber layer and constitutes the non-skin side. Each of the two fiber layers contains water-retaining fibers, and the content of the high-molecular-weight phenolic compound in the water-retaining fibers in the second fiber layer is equal to the content of the high-molecular-weight phenolic compound in the water-retaining fibers in the first fiber layer. To provide an absorbent article having a large content compared to the content of

The absorbent article of the present invention has a surface sheet with good texture and bodily fluid absorbency, excellent rewet prevention performance, and excellent antibacterial properties.

Fig. 2 is a plan view showing the unfolded state of the sanitary napkin according to the embodiment; (a) is a cross-sectional view taken along line II-II of FIG. 1, and (b) is a partially enlarged cross-sectional view of FIG. 2(a). It is a top view of the surface sheet concerning an embodiment. FIG. 3 is a partially enlarged cross-sectional view of a top sheet and an auxiliary sheet indicated by IV in FIG. 2(a); 4 is a partially enlarged view of the inside of the topsheet according to the embodiment; FIG. It is a schematic diagram which shows the structural example of the manufacturing apparatus of a sanitary napkin. It is a figure explaining typically the manufacturing method of a sanitary napkin.

Aspects of the present invention are described below.

[First aspect]
(composition)
An absorbent article comprising a topsheet having a skin side and a non-skin side, a backsheet, and an absorbent body positioned between the topsheet and the backsheet,
The surface sheet is
A first fiber layer constituting the skin side surface, and a second fiber layer adjacent to the non-skin side of the first fiber layer and constituting the non-skin side surface,
each of the first fiber layer and the second fiber layer contains a water-retentive fiber;
The absorbent article, wherein the content of the polymer phenol compound in the water-retaining fibers in the second fiber layer is greater than the content of the polymer phenol compound in the water-retaining fibers in the first fiber layer.

(effect)
In the absorbent article of the first aspect of the present invention, since the topsheet contains water-retaining fibers, the touch of the topsheet can be improved.
Further, the absorbent article of the first aspect of the present invention comprises a first fiber layer and a second fiber layer, and in the second fiber layer located on the non-skin side, the water-retaining fibers contain a polymer phenol compound. more quantity.
Here, since the polymer phenolic compound is hydrophobic, the existence of a larger amount of the polymer phenolic compound on the non-skin side of the topsheet facilitates the blockage of bodily fluids located on the non-skin side. Therefore, under the condition that a load is applied to the absorbent article, the absorbent article has excellent rewet prevention performance, which is a property that the body fluid contained in the absorbent body does not readily return to the skin side of the topsheet.
On the other hand, since the content of the polymer phenol compound in the water-retentive fibers in the first fiber layer is smaller, the absorbent article has good body fluid absorbency, which is the property of quickly absorbing body fluid adhering to the skin. can be
In addition, since the polymer phenolic compound itself has antibacterial properties, the water-retentive fiber containing a larger amount of the polymer phenolic compound suppresses the propagation of bacteria on the surface sheet, and the antibacterial properties of the surface sheet. increases.

[Second aspect]
(composition)
said at least said second fiber layer comprising thermoplastic resin fibers;
The amount of the thermoplastic resin fibers present in the second fiber layer is greater than the amount of the thermoplastic resin fibers present in the first fiber layer.
The absorbent article according to the first aspect.

(effect)
According to the second aspect of the present invention, at least the second fiber layer contains thermoplastic resin fibers, thereby increasing the mechanical strength of the topsheet. In addition, since the amount of thermoplastic resin fibers present in the second fiber layer is greater than that in the first fiber layer, the texture of the topsheet can be maintained well, and the second fiber layer is more hydrophobic. By increasing, the rewet prevention performance is further enhanced.

[Third aspect]
(composition)
The absorbent article according to the second aspect, wherein at least a portion of the water-retentive fibers contained in the first fiber layer is coated with a molten thermoplastic resin.

(effect)
In general, water-retentive fibers are excellent in touch, but tend to have low mechanical strength and tend to fluff easily. According to the third aspect of the present invention, at least some of the water-retaining fibers contained in the first fiber layer are coated with a thermoplastic resin melt, so that at least some of the water-retaining fibers are mechanically The strength is increased, and the mechanical strength of the topsheet is increased.
In addition, since the water-retentive fibers are less likely to move within the topsheet, the topsheet can be prevented from fluffing.

[Fourth aspect]
(composition)
At least some of the water-retentive fibers are coated with a melt of a thermoplastic resin in at least some of the entangled portions of the fibers,
The proportion of the intertwined portions covered with the melt of the thermoplastic resin in the second fiber layer is compared to the proportion of the intertwined portions covered with the melt of the thermoplastic resin in the first fiber layer. The absorbent article according to the third aspect, which is large in size.

(effect)
According to the fourth aspect of the present invention, the thermoplastic resin fiber contains a thermoplastic resin, and the water-retentive fiber is heat- The mechanical strength of the surface sheet is enhanced because it is coated with the molten plastic resin.
In addition, since the water-retentive fibers are less likely to move within the topsheet, the topsheet can be prevented from fluffing.
Furthermore, among the entangled portions of the fibers, the existence ratio of the entangled portion covered with the melt of the thermoplastic resin in the second fiber layer is the entangled portion covered with the melt of the thermoplastic resin in the first fiber layer. Since it is large compared to the existing ratio of the portions, the feel of the topsheet is less likely to deteriorate.

[Fifth aspect]
(composition)
The absorbent article according to any one of the second to fourth aspects, wherein the fiber length of the thermoplastic resin fibers is longer than the fiber length of the water-retentive fibers.

(effect)
According to the fifth aspect of the present invention, since the fiber length of the thermoplastic resin fibers is longer than the fiber length of the water-retaining fibers, the thermoplastic resin fibers are entangled with the plurality of water-retaining fibers, and the entangled portions are It is coated with a melt of thermoplastic resin.
As a result, the thermoplastic resin fibers and the plurality of water-retentive fibers form a complex crosslinked structure, which increases the mechanical strength of the surface sheet.

[Sixth aspect]
(composition)
The absorbent article according to any one of the second to fifth aspects, wherein the thermoplastic resin fiber is a composite fiber, and the resin component having a low melting point is exposed on the surface of the composite fiber.

(effect)
According to the sixth aspect of the present invention, the thermoplastic resin fiber is a composite fiber in which a resin component having a low melting point is exposed on the surface of the composite fiber, so that one of the resin components exposed on the surface melts. However, the other resin component can maintain the fiber structure, and under the condition that the one resin component exposed to the surface is melted, the mechanical strength of the top sheet is increased while the bulkiness of the top sheet is reduced. Easy to maintain.

[Seventh aspect]
(composition)
The fiber density of the second fiber layer is higher than the fiber density of the first fiber layer,
The absorbent article according to any one of the first to sixth aspects.

(effect)
According to the seventh aspect of the present invention, the fiber density of the second fibrous layer is higher than that of the first fibrous layer. It can be quickly drawn into the fiber layer, and the skin side of the top sheet can be more dry, which is a property that makes it difficult for body fluids to be retained, and the permeability in the thickness direction of the body fluid contained inside the top sheet. It is possible to increase the body fluid permeability.

[Eighth aspect]
(composition)
The absorbent article according to any one of the first to seventh aspects above, wherein the average distance between fibers in the second fibrous layer is shorter than the average distance between fibers in the first fibrous layer.

(effect)
According to the eighth aspect of the present invention, since the average distance between fibers in the second fibrous layer is shorter than the average distance between fibers in the first fibrous layer, permeation into the interior of the topsheet by capillary force It is possible to quickly draw the bodily fluids that have been absorbed into the second fiber layer, thereby enhancing the dryness of the skin side of the topsheet and increasing the permeability of the topsheet to bodily fluids.

[Ninth aspect]
(composition)
The absorbent article according to any one of the first to eighth aspects above, wherein the topsheet comprises a particulate material having a high polymeric phenolic compound content compared to the water-retentive fibers.

(effect)
According to the ninth aspect of the present invention, the anti-rewet performance of the topsheet is enhanced by providing the topsheet with a polymeric phenolic compound-rich particulate material.

[Tenth Aspect]
(composition)
Each of the first fiber layer and the second fiber layer includes, as water-retaining fibers, first water-retaining fibers and second water-retaining fibers,
The content of the high-molecular-weight phenolic compound in the first water-retaining fibers is greater than the content of the high-molecular-weight phenolic compound in the second water-retaining fibers,
The amount of the second water-retaining fibers in the first fiber layer is greater than the amount of the second water-retaining fibers in the second fiber layer,
The amount of the first water-retaining fibers in the second fiber layer is greater than the amount of the first water-retaining fibers in the first fiber layer,
The absorbent article according to any one of the first to ninth aspects.

(effect)
According to the tenth aspect of the present invention, the second fiber layer constituting the non-skin side of the topsheet contains a large amount of the first water-retaining fibers containing a large amount of the high-molecular-weight phenolic compound. is excellent in rewet prevention performance.
In addition, since the first fiber layer constituting the non-skin side of the topsheet contains a large amount of the second water-retentive fibers having a lower content of the high-molecular-weight phenolic compound, the body fluid absorbency of the topsheet in the absorbent article is maintained. be done.

[Eleventh aspect]
(composition)
An auxiliary sheet is provided between the surface sheet and the absorbent body,
The surface sheet and the auxiliary sheet are
a plurality of protrusions extending along the longitudinal direction of the absorbent article and positioned at intervals in the width direction of the absorbent article;
a plurality of recesses extending along the longitudinal direction of the absorbent article and positioned between adjacent protrusions;
and the plurality of protrusions of the auxiliary sheet are fitted to the non-skin surface of the plurality of protrusions of the topsheet.

(effect)
According to the eleventh aspect of the present invention, the top sheet has projections and recesses, and the projections of the top sheet are supported by the auxiliary sheet. The uneven structure of the surface sheet is maintained. As a result, the contact area between the topsheet and the skin is reduced, so that the feel of the topsheet is improved.

[Twelfth aspect]
(composition)
the widthwise dimension of the topsheet is smaller than the widthwise dimension of the auxiliary sheet;
The absorbent article according to the eleventh aspect, wherein the widthwise edges of the topsheet are not joined to the auxiliary sheet.

(effect)
According to the twelfth aspect of the present invention, the dimension in the width direction of the top sheet is smaller than the dimension in the width direction of the auxiliary sheet, and both edges in the width direction of the top sheet are not joined to the auxiliary sheet. By structuring the wall surface with both edges of the surface sheet slightly rising, it is possible to effectively prevent body fluid from leaking along the width direction.

<Sanitary napkin>
A sanitary napkin will be described as an example of the absorbent article according to the embodiment. However, the types and uses of the absorbent article of the present invention are not limited to those examples, and can be applied to other absorbent articles as long as they do not depart from the scope of the subject matter of the present invention. Other absorbent articles include, for example, pantiliners, light incontinence pads, and disposable diapers.

1 and 2 are diagrams showing configuration examples of a sanitary napkin 1 according to an embodiment. 1 is a plan view showing the unfolded state of the sanitary napkin 1, FIG. 2(a) is a cross-sectional view taken along line II-II of FIG. 1, and FIG. 2(b) is FIG. 2(a). 1 is a partially enlarged cross-sectional view of FIG. The sanitary napkin 1 of this embodiment has a longitudinal direction L, a width direction W and a thickness direction T which are orthogonal to each other. In the sanitary napkin 1 depicted in FIG. 1, the upper and lower sides of the figure are the front and rear sides in the longitudinal direction L, and the left and right sides are the left and right sides in the width direction W, respectively, and the front side with respect to the paper surface. and the back side are the upper side and the lower side in the thickness direction T, respectively. The sanitary napkin 1 has a longitudinal center line CL (virtual line) extending in the longitudinal direction L through the center of the width direction W, and a width direction center line _CW (virtual line) extending in the width direction _W through the center of the longitudinal direction L. line). The direction and the side toward the longitudinal center line _CL are defined as the inward direction and the inner side in the width direction W, respectively, and the direction and the side away from the longitudinal center line CL are defined as the outward direction and the outer side in the width direction W, respectively. On the other hand, the direction and the side toward the center line _CW in the width direction are defined as the inward direction and the inner side in the longitudinal direction L, respectively, and the direction and the side away from the center line CW are defined as the outward direction and the outer side in the longitudinal direction L, respectively. When the sanitary napkin 1 placed on a plane including the longitudinal direction L and the width direction W is viewed from the upper side in the thickness direction T, it is called "planar view", and the shape grasped in plan view is called "planar shape". An arbitrary direction within a plane including the longitudinal direction L and the width direction W is called a "planar direction". When the wearer wears the sanitary napkin 1, the sides in the thickness direction T that are relatively close to and far from the wearer's skin surface are referred to as the "skin side" and the "non-skin side." These definitions are commonly used for each material of the sanitary napkin 1 as well.

In the present embodiment, the sanitary napkin 1 (excluding the wing portion) has a substantially rectangular shape that is long in the longitudinal direction L and short in the width direction W in a plan view, and that both edges in the longitudinal direction L are substantially semicircular. . However, the shape is not particularly limited as long as it is long in the longitudinal direction L and short in the width direction W, and examples thereof include rounded rectangles, ellipses, hourglass shapes, and similar shapes. The sanitary napkin 1 has wings 9 extending outward in the width direction W from a substantially rectangular portion, and the wings 9 have a substantially trapezoidal shape. However, the shape of the wing portion 9 may be semicircular or semielliptical, for example.

In this embodiment, the sanitary napkin 1 comprises a topsheet 2 forming the skin-side surface of the sanitary napkin 1, a backsheet 3 forming the non-skin-side surface of the sanitary napkin 1, the topsheet 2 and and an absorbent body 4 arranged between the backsheets 3. Moreover, in this embodiment, the sanitary napkin 1 further includes an auxiliary sheet 5 and a pair of side sheets 6 , 6 . The auxiliary sheet 5 is arranged so as to overlap the non-skin side of the topsheet 2 . Each of the pair of side sheets 6, 6 is joined to both ends of the auxiliary sheet 5 in the width direction W on the non-skin side so that the inner end in the width direction W overlaps, and the outer side in the width direction W procrastinating. Therefore, in this embodiment, the absorbent body 4 is positioned between the top sheet 2, the auxiliary sheet 5, and the pair of side sheets 6, 6 and the back sheet 3. As shown in FIG. However, an exterior sheet may be provided on the non-skin side of the backsheet 3 .

[First fiber layer and second fiber layer]
The topsheet 2 is a liquid-permeable sheet and includes a first fiber layer 2a and a second fiber layer 2b. The skin side of the first fiber layer 2a constitutes the skin side of the topsheet 2. As shown in FIG. The second fiber layer 2b is adjacent to the non-skin side of the first fiber layer 2a. In this embodiment, the non-skin-side surface of the second fibrous layer 2b constitutes the non-skin-side surface of the topsheet 2, and therefore the topsheet 2 has a two-layer structure. In this embodiment, the first fiber layer 2a refers to a fiber layer closer to the skin than a plane parallel to the planar direction passing through the center of the thickness direction T of the width direction center line _CW of the topsheet 2. , the second fiber layer 2b refers to a fiber layer on the non-skin side of a plane passing through the center of the thickness direction T and parallel to the plane direction.

(water-retentive fiber)
The first fiber layer 2a and the second fiber layer 2b contain water-retentive fibers. By including the water-retentive fibers in the first fiber layer 2a and the second fiber layer 2b, at least the feel of the topsheet 2 can be improved.
The water-retentive fiber is not particularly limited as long as it has a property of absorbing and retaining water (water retentivity). Examples of water-retentive fibers include cellulosic fibers. Cellulosic fibers are not particularly limited as long as they contain cellulose, and examples thereof include natural cellulose fibers, regenerated cellulose fibers, refined cellulose fibers and semi-synthetic cellulose fibers. Examples of natural cellulose fibers include plant fibers such as seed hair fibers (example: cotton), pistil fibers (example: hemp), leaf vein fibers (example: Manila hemp), and fruit fibers (example: palm). Cotton includes, for example, Hirszum cotton (example: Upland cotton), Barbadense cotton, Arboreum cotton, and Helvaceum cotton. Organic cotton or pre-organic cotton (trademark) may be used as cotton. However, organic cotton means cotton certified by GOTS (Global Organic Textile Standard). Regenerated cellulose fibers include fibers such as rayon, e.g., viscose rayon obtained from viscose, polynosic and modal, cuprammonium rayon (also referred to as "cupra") obtained from cuprammonium salt solutions of cellulose. . As the purified cellulose fiber, lyocell, specifically pulp, is dissolved in an aqueous solution of N-methylmorpholine N-oxide to form a spinning stock solution (dope), which is extruded into a dilute solution of N-methylmorpholine N-oxide. Examples include fibers. Purified cellulose is commercially available, for example, as Tencel™. Semi-synthetic cellulose fibers include fibers such as semi-synthetic cellulose, such as acetate fibers, such as triacetate and diacetate. Among these, natural cellulose fibers are preferred, cotton is more preferred, and Hirsutum cotton is even more preferred, from the viewpoint of water retention and texture. In the present embodiment, the water-retentive fiber is Hirsutum cotton (hereinafter also simply referred to as "cotton fiber").

(Polymer phenol compound)
In the present embodiment, the water-retaining fibers contain a high-molecular-weight phenolic compound, and compared to the content of the high-molecular-weight phenolic compound in the water-retaining fibers in the first fiber layer 2a, the water-retaining properties in the second fiber layer 2b The content of high-molecular-weight phenolic compounds in the fibers is high.
Since the polymer phenolic compound is hydrophobic, the existence of a larger amount of the polymer phenolic compound on the non-skin side of the topsheet 2 makes it easier to block body fluids located on the non-skin side of the topsheet 2 . Therefore, the sanitary napkin 1 has excellent rewetting prevention performance.
On the other hand, since the content of the polymer phenolic compound in the water-retentive fibers in the first fiber layer 2a is smaller, the sanitary napkin 1 can have good body fluid absorbency.
Here, the polymer phenol compound generally refers to a compound called polyphenol, and includes catechin, anthocyanin, tannin, rutin, isoflavone, lignan, coumarin, and lignin. Preferred are water-insoluble/sparingly soluble polymeric phenolic compounds that do not readily detach from the fibers. In particular, when natural cellulose fibers are used as the water-retentive fibers, lignin, which coexists with cellulose fibers in the plant body, can be mentioned as the high-molecular phenolic compound. Lignin itself is insoluble/poorly soluble in water, and in addition, in natural cellulose fibers, it coexists with cellulose fibers and strongly binds to them. Does not fall off easily from fibers. Therefore, by adopting lignin as the high-molecular-weight phenol compound, the rewet-preventing performance and antibacterial properties of the topsheet 2 can be maintained for a long period of time even when body fluids are repeatedly excreted.
Since the polymer phenolic compound itself has antibacterial properties, the water-retentive fiber containing the polymer phenolic compound suppresses the propagation of bacteria on the topsheet 2 and enhances the antibacterial properties of the topsheet 2 .

In order to adjust the content of the polymer phenol compound in the water-retainable fiber, for example, a method of adjusting the reaction conditions for removing the polymer phenol compound from the water-retainable fiber containing the polymer phenol compound should be adopted. Just do it. More specifically, when the water-retentive fibers are natural cellulose fibers, the reaction temperature, The amount of lignin in the natural cellulose fiber may be adjusted by adjusting the reaction time, pH, bleaching agent concentration, and the like.

The content of the polymer phenol compound in the water-retentive fibers in the first fiber layer 2a is, for example, 0% by mass or more and 40% by mass or less. If it exceeds 40% by mass, the abundance of the high-molecular phenolic compound in the first fiber layer 2a is too large, and the body fluid absorbency of the first fiber layer 2a is reduced, resulting in the body fluid excreted by the wearer and the wearer's body fluid. It may be difficult to absorb bodily fluids adhering to the skin. The content of the polymer phenol compound in the water-retentive fibers in the first fiber layer 2a is preferably 0% by mass or more and 30% by mass or less, more preferably 0% by mass or more and 20% by mass or less.
The content of the polymer phenol compound per unit area in the first fiber layer 2a is, for example, 0 g/cm ² or more and 16 g/cm 2 or less, preferably 0 g/cm ^{2 or} more and 13 g/cm ² or less. , 0 g/cm ² or more and 10 g/cm ² or less.
Moreover, the content of the polymer phenol compound in the water-retentive fibers in the second fiber layer 2b is, for example, 0.1% by mass or more and 75% by mass or less. If it is less than 0.1% by mass, the water repellency of the second fiber layer 2b may be insufficient, and the rewet prevention performance of the topsheet 2 may deteriorate. If it exceeds 75% by mass, the permeability of the second fiber layer 2b to body fluids may decrease. The content of the polymer phenol compound in the water-retaining fibers in the second water-retaining fibers is preferably 0.3% by mass or more and 40% by mass or less, more preferably 0.5% by mass or more and 30% by mass or less.
The content of the polymer phenol compound per unit area in the second fiber layer 2b is, for example, 0.001 g/cm ² or more and 20 g/cm 2 or less, and 0.005 g/cm ^{2 or} more and 15 g/cm 2 or more. ² or less is preferable, and 0.01 g/cm ² or more and 10 g/cm ² or less is more preferable.

(First water-retaining fiber and second water-retaining fiber)
In addition, in the first fiber layer 2a and the second fiber layer 2b, when adjusting the content of the polymer phenol compound in the water-retentive fibers, as described above, the content of the polymer phenol compound is adjusted to obtain a high Two types of water-retaining fibers (for example, a first water-retaining fiber and a second water-retaining fiber) having different molecular phenolic compound contents are used, and each of these two types of water-retaining fibers in the surface sheet 2: The content of the high-molecular-weight phenolic compound in the water-retentive fibers in each of the first fiber layer 2a and the second fiber layer 2b can be adjusted by adjusting the gradients to be different.
In this case, the combination of the first water-retaining fibers and the second water-retaining fibers is such that, for example, the first water-retaining fibers are natural cellulose fibers that have not undergone any degreasing/delignification process or bleaching process, and the second water-retaining fibers are A combination in which the fibers are natural cellulose fibers that have undergone a degreasing/delignification process but have not undergone a bleaching process, or a combination in which the first water-retaining fibers have undergone a degreasing/delignification process but have undergone a bleaching process. and the second water-retaining fibers are natural cellulose fibers that have undergone a degreasing/delignification step and a bleaching step.
In the present embodiment, the first fiber layer 2a and the second fiber layer 2b contain the first water-retaining fiber and the second water-retaining fiber as the water-retaining fibers, and the polymer phenol compound contained in the first water-retaining fiber is greater than the content of the polymer phenolic compound contained in the second water-retentive fibers. However, in adjusting the content of the high-molecular-weight phenolic compound in the water-retaining fibers in the first fiber layer and the second fiber layer, a mode in which a plurality of types of water-retaining fibers having different contents of the high-molecular-weight phenolic compound are used. The content of the polymer phenolic compound in the water-retentive fiber may be adjusted in a manner other than the above.

In the present embodiment, the abundance of the first water-retaining fibers in the second fiber layer 2b is greater than the abundance of the first water-retaining fibers in the first fiber layer 2a, and the first fiber layer 2a, The abundance of the second water-retaining fibers is greater than the abundance of the second water-retaining fibers in the second fiber layer 2b. Since the polymer phenolic compound contained in the water-retentive fibers is hydrophobic, the existence of a larger amount of the polymer phenolic compound on the non-skin side of the surface sheet 2 makes it easier to block body fluids located on the non-skin side. Become. Therefore, the rewet prevention performance is excellent without impairing the absorbability of body fluids.
In the present embodiment, the amount of the first water-retainable fibers and the second water-retainable fibers on the skin side of the topsheet 2 is such that the amount of the second water-retainable fibers is the same as the amount of the first water-retainable fibers. The amount of the first water-retaining fibers is relatively large, and on the non-skin side of the topsheet 2, the amount of the first water-retaining fibers is greater than the amount of the second water-retaining fibers.

The fiber length of the second water-retentive fibers is, for example, 10 mm or more and 80 mm or less. If the fiber length is less than 10 mm, the fiber length is too short, making it difficult for the fibers to entangle with each other, and there is a risk that sufficient strength cannot be obtained. above 80 mm, some of such fibers may extend in the width direction W, resulting in fiber spanning from one thigh edge of the wearer to the other thigh edge; In this case, due to the body fluid diffusing effect of the second water-retentive fibers, the body fluid adhering to the central portion in the width direction W of the sanitary napkin 1 may diffuse to both thighs and cause discomfort to the wearer. . The fiber length is preferably 15 mm or more and 60 mm or less, more preferably 20 mm or more and 40 mm or less. Correspondingly, the average fiber length of the second water-retentive fibers is, for example, 15 mm or more and 50 mm or less, preferably 20 mm or more and 45 mm or less, and more preferably 25 mm or more and 40 mm or less.

In addition, the fineness, fiber length, and average fiber length of fibers other than the water-retaining fibers in the first fiber layer 2a are also about the same as the water-retaining fibers (from 0.5 times to within a range of 2 times) is preferred. However, in this embodiment, no fibers other than the water-retentive fibers are used.

Further, the fiber length of the first water-retaining fibers is, for example, 10 mm or more and 80 mm or less, but it is preferable that the average fiber length is shorter than the average fiber length of the second water-retaining fibers. The fiber length of the fibers is, for example, 3 mm or more and 40 mm or less. If the fiber length is less than 10 mm, the fiber length is too short, making it difficult for the fibers to entangle with each other, and there is a risk that sufficient strength cannot be obtained. above 80 mm, some of such fibers may extend in the width direction W, resulting in fiber spanning from one thigh edge of the wearer to the other thigh edge; In this case, due to the body fluid diffusing effect of the first water-retentive fibers, the body fluid adhering to the central portion of the sanitary napkin 1 in the width direction W may diffuse to both thighs and cause discomfort to the wearer. . The fiber length of the first water-retentive fibers is preferably 5 mm or more and 35 mm or less, more preferably 10 mm or more and 35 mm or less. Correspondingly, the average fiber length of the first water-retentive fibers is, for example, 5 mm or more and 30 mm or less, preferably 10 mm or more and 25 mm or less, and more preferably 15 mm or more and 20 mm or less.

In addition, in the first fiber layer 2a and the second fiber layer 2b, if the average fiber length of the first water-retaining fibers is shorter than the average fiber length of the second water-retaining fibers, then at least the first water-retaining fibers The fibers constituting the second fiber layer 2b, which are present in large amounts, are brought closer to each other, and the distance between the fibers is shorter than that of the fibers constituting the first fiber layer 2a, so that the fibers of the second fiber layer 2b The density is higher than the fiber density of the first fiber layer 2a. As a result, a stronger capillary force can be generated to draw in body fluids, and the dryness of the topsheet 2 on the skin side can be enhanced, and the permeability of the topsheet 2 to body fluids can be enhanced.

(Thermoplastic resin fiber)
At least the second fiber layer 2b contains thermoplastic resin fibers.
The thermoplastic resin fiber is not particularly limited as long as it contains a thermoplastic resin. Examples of thermoplastic resins include olefin resins such as polyethylene (PE), polypropylene (PP), ethylene-vinyl acetate copolymer (EVA), and polyester resins such as polyethylene terephthalate (PET) and polylactic acid (PLA). and known resins such as polyamide resins such as 6-nylon, and these resins may be used alone or in combination of two or more. In addition, the structure of fibers made of such a thermoplastic resin is not particularly limited, and examples thereof include composite fibers such as core-sheath type fibers, side-by-side type fibers, and island/sea type fibers; hollow type fibers; Flat, Y-shaped, C-shaped, and other modified cross-section fibers; Latent crimped or actual crimped three-dimensional crimped fibers; A single structured fiber may be used, or two or more types of fibers may be used in combination. In this embodiment, the thermoplastic resin fiber is a PP/PE core-sheath type composite fiber. Thermoplastic resin fibers may exhibit hydrophobicity, and the term “hydrophobicity” as used herein refers to a property that is difficult to blend with water or difficult to retain moisture. : specific resistance value of 10 MΩ·cm) is about 80° to 100°.
At least the second fiber layer 2b contains thermoplastic resin fibers, so that the mechanical strength of the topsheet 2 can be enhanced. In addition to the second fiber layer 2b, the first fiber layer 2a may also contain thermoplastic resin fibers.

FIG. 5 is a partially enlarged view of the interior of the topsheet 2 according to the embodiment. In this embodiment, the thermoplastic resin fiber is a conjugate fiber containing a thermoplastic resin, and the resin component having a low melting point is exposed on the surface of the conjugate fiber. More specifically, the thermoplastic resin fiber is a core-sheath type composite fiber in which the melting point of the sheath component is lower than the melting point of the core component. Since the thermoplastic resin fibers _F2 are core-sheath type conjugate fibers containing a thermoplastic resin, at least a part of the water-retaining fibers _F1 contained in the first fiber layer 2a are made of a thermoplastic resin melt _F2M. More specifically, at least part of the water-retaining fibers _F1 , such as the first water-retaining fibers and the second water-retaining fibers, is coated with heat in at least part of the entangled part _PE between the fibers It is coated with a thermoplastic resin melt _F2M contained in the plastic resin fiber _F2 . In general, the water-retentive fiber _F1 is excellent in touch, but tends to have low mechanical strength of the fiber itself, and _tends to fluff easily. By being covered with the material _F2M , the mechanical strength of the topsheet 2 is increased, and the water-retaining fibers are less likely to move within the topsheet 2, so that the topsheet 2 can be prevented from fluffing. Further, since the melting point of the sheath component is lower than the melting point of the core component, even if the sheath component melts, the core component can maintain the fiber structure. The bulkiness of the surface sheet 2 can be easily maintained while the mechanical strength of the surface sheet 2 is increased.

In this embodiment, the average fiber length of the thermoplastic resin fibers _F2 is longer than the average fiber length of the water-retentive fibers described above. As a result, the thermoplastic resin fiber _F2 is entangled with a plurality of water-retaining fibers _F1 (the first water-retaining fiber and the second water-retaining fiber), and the entangled portion _PE is formed by the thermoplastic resin melt _F2M . covered. Therefore, the thermoplastic resin fiber _F2 and a plurality of water-retentive fibers form a complex crosslinked structure, so that the mechanical strength of the surface sheet 2 is increased.
That is, in the thermoplastic resin fiber _F2 containing a thermoplastic resin, the thermoplastic resin fiber _F2 /the thermoplastic resin fiber _F2 and the water-retentive fiber _F1 are bonded to each other at the entangled portion _PE ( fusion). Such fused thermoplastic resin fibers _F2 can be regarded as forming a kind of matrix of thermoplastic resin fibers in the first fiber layer 2a and the second fiber layer 2b.
In the sanitary napkin 1 having such a configuration, the shapes of the first fiber layer 2a and the second fiber layer _2b are stably maintained by the heat-sealed thermoplastic resin fibers F2 in the second fiber layer 2b. can. Therefore, even if the average fiber length of the water-retaining fibers _F1 contained in the first fiber layer 2a and the second fiber layer 2b is relatively short, the water-retaining fibers _F1 are incorporated into (within the matrix of) the thermoplastic resin fibers. It can be held stably without bias. As a result, the body fluid drawn into the first fiber layer 2a and the second fiber layer 2b can be stably transferred to the absorbent body 4 (and the auxiliary sheet 5) without unevenness, and the body fluid permeability can be enhanced. The thermoplastic resin fibers of the sanitary napkin may not contain such a thermoplastic resin.
In the present embodiment, the existence ratio of the entangled portions _PE covered with the thermoplastic resin melt _F2M in the second fiber layer 2b is changed by the thermoplastic resin melt _F2M in the first fiber layer 2a. It is large compared to the existence ratio of the covered entangled parts _PE . As a result, the existence ratio of the entangled portions _PE covered with the melted material _F2M , which may deteriorate the feel of the skin, is small in the first fiber layer 2a. , the texture of the surface sheet 2 is less likely to deteriorate.

In the first fiber layer 2a and the second fiber layer 2b, the amount of thermoplastic resin fibers present in the second fiber layer 2b is greater than the amount of thermoplastic resin fibers present in the first fiber layer 2a. is greater than the amount of water-retaining fibers in the second fiber layer 2b. As a result, at least the feel of the topsheet 2 can be improved, and the rewet prevention performance is further enhanced by the presence of the second fiber layer 2b having a larger amount of the first water-retentive fibers.

The proportion of the thermoplastic resin fibers among the fibers constituting the first fiber layer 2a is preferably 0% by mass or more and less than 30% by mass, and is preferably 0% by mass or more and 20% by mass or less, from the viewpoint of enhancing the texture of the surface sheet 2. More preferably, 0% by mass or more and 10% by mass or less is even more preferable. When the amount is less than 30% by mass, the wearer can easily recognize the first fiber layer 2a as a layer containing water-retaining fibers, so that good touch feeling can be ensured. In addition, in this embodiment, the proportion of the water-retentive fiber is 100% by mass.

The ratio of the thermoplastic resin fibers in the fibers forming the second fiber layer 2b is not particularly limited as long as it is higher than the ratio of the thermoplastic resin fibers in the first fiber layer 2a. The proportion of thermoplastic resin fibers is, for example, 5% by mass or more and less than 60% by mass. If it is 60% by mass or more, there is a possibility that the feeling of touch may deteriorate when pressure is applied in the thickness direction. If the content is less than 5% by mass, the effect of the thermoplastic resin fibers to prevent fluffing may be reduced. The proportion of thermoplastic resin fibers is preferably 10% by mass or more and 40% by mass or less, more preferably 20% by mass or more and 30% by mass or less. The second fiber layer 2b may contain a third fiber in addition to the water-retentive fiber and the thermoplastic resin fiber.

The ease of entanglement between the thermoplastic resin fibers of the second fiber layer 2b and the water-retaining fibers that are the main fibers of the first fiber layer 2a, that is, the ease of transfer of body fluids from the first fiber layer 2a, From the viewpoint of preventing separation between the fiber layer 2a and the second fiber layer 2b, the fineness of the thermoplastic resin fibers is preferably smaller than that of the water-retentive fibers (fine fiber diameter).
Moreover, the fiber length of the thermoplastic resin fiber is not particularly limited, and is, for example, 10 mm or more and 80 mm or less. However, the ease of entanglement between the thermoplastic resin fibers of the second fiber layer 2b and the water-retentive fibers that are the main fibers of the first fiber layer 2a, that is, the ease of migration of body fluids from the first fiber layer 2a, From the viewpoint of preventing separation between the first fiber layer 2a and the second fiber layer 2b, the fiber length of the thermoplastic resin fibers is preferably longer than the fiber length of the water-retentive fibers. Correspondingly, the average fiber length of the thermoplastic resin fibers is, for example, 15 mm or more and 50 mm or less.

The thickness of each of the first fiber layer 2a and the second fiber layer 2b is not particularly limited. more preferred. However, from the viewpoint of improving the texture and improving the rewet prevention performance and body fluid absorption of the topsheet 2, the first fiber layer 2a and the second fiber layer 2b are preferably thicker. The thickness of the surface sheet 2 is not particularly limited, and is, for example, 0.1 mm or more and 5 mm or less, preferably 0.4 mm or more and 4 mm or less, and more preferably 0.8 mm or more and 3 mm or less. If it is less than 0.1 mm, the texture may be impaired. If it exceeds 5 mm, the retention of body fluids is too high, body fluids tend to remain in the water-retentive fibers, and dryness may be impaired.

The present invention also relates to nonwoven fabrics.
The nonwoven fabric of the present invention has a top surface and a bottom surface,
A first fiber layer forming an upper surface, and a second fiber layer adjacent to the lower surface side of the first fiber layer and forming the lower surface,
each of the first fiber layer and the second fiber layer contains a water-retentive fiber;
The content of the polymer phenol compound in the water-retaining fibers in the second fiber layer is greater than the content of the polymer phenol compound in the water-retaining fibers in the first fiber layer.

Such a nonwoven fabric can be used not only as a surface sheet for absorbent articles, but also as arbitrary sheets such as auxiliary sheets, side sheets, core wrap sheets, carrier sheets, and exterior sheets in absorbent articles. The nonwoven fabric of the present invention may be used as a nonwoven fabric constituting face masks, wet wipes, and puffs.

[Various measurement methods]
Unless otherwise specified, the high-molecular-weight phenolic compound content in the water-retaining fibers and the first water-retaining fibers/second water-retaining fibers means the content of the high-molecular-weight phenolic compound per unit mass of these fibers. do.
In a sheet such as a fiber layer, the content of the high-molecular-weight phenolic compound in the water-retaining fibers in the first fiber layer and the second fiber layer is measured as follows. For example, the fiber layer is frozen with liquid nitrogen or the like as necessary, and separated from the center in the thickness direction T into the first fiber layer and the second fiber layer. The weight of each fiber layer is measured, and the polymer phenol compound is quantified from the fibers constituting each fiber layer using any technique used for detecting polymer phenol compounds. For example, in water-retentive fibers, when quantifying the content of high-molecular-weight phenolic compounds represented by lignin, etc., a known detergent fiber analysis method using a surfactant is used / applied, and The content of the polymeric phenolic compound in can be measured.
In quantifying the content of the high molecular weight phenol compound in the water-retentive fiber, if it is necessary to remove the mixed thermoplastic resin fiber, for example, the first fiber in any organic solvent (eg, decahydronaphthalene) The layer or the second fiber layer may be melted and heated and stirred as necessary.
Further, in the case of dyeing a high-molecular-weight phenolic compound by a staining method and performing colorimetric determination, for example, as a method of dyeing lignin, which is one of the high-molecular-weight phenolic compounds, the phloroglucinol/hydrochloric acid method can be mentioned. , but not limited to.
Furthermore, when the water-retentive fiber is cotton fiber and the polymer phenolic compound is lignin, the content of the polymer phenolic compound in the cotton fiber can be estimated from the color difference in the L*a*b* color system. . For example, a sheet of nonwoven fabric made of 100% cotton fiber and having a basis weight of 30 g/cm ² is placed on a white board, and the formula difference is measured with a color difference meter CR-300 manufactured by Konica Minolta, Inc., the cotton fiber If the fiber is bleached cotton fiber, the formula difference between the front and back sides is 0.06 (n=20), and if the cotton fiber is unbleached cotton fiber, the formula difference between the front and back sides is 0.18 (n=20). . On the other hand, a spunlace nonwoven fabric formed by hydroentangling with 30 parts by mass of bleached cotton fibers on the front side and 40 parts by mass of unbleached cotton fibers on the back side has a formula difference of 0.55 (n = 20). Therefore, if the formula difference between the skin side and the non-skin side is 0.3 or more under the same conditions, it can be estimated that one side has a large content of the polymer phenol compound.

When measuring the content of the polymer phenol compound in the first water-retaining fiber and the second water-retaining fiber, if the first water-retaining fiber and the second water-retaining fiber as raw materials are available, each raw material Therefore, the content of the polymer phenol compound per unit mass can be measured according to the above method. In addition, when measuring the content of the high-molecular-weight phenol compound in the first water-retentive fiber and the second water-retentive fiber in the state of non-woven fabric, the difference in physical properties according to the difference in the content of the high-molecular-weight phenol compound Focusing on this, the first water-retainable fibers and the second water-retainable fibers are separated from the nonwoven fabric, respectively, and the contents of the high-molecular phenol compounds in the collected first water-retainable fibers and second water-retainable fibers are measured. Just do it. Illustratively, the first water-retaining fibers and the second water-retaining fibers are dyed as necessary, and separated under a microscope based on the difference in color of the water-retaining fibers to obtain the first water-retaining fibers and the second water-retaining fibers. A method of measuring the content of the polymer phenol compound per unit mass in the second water-retentive fiber is exemplified.

When calculating the content of the polymer phenol compound in the water-retentive fibers in the first fiber layer and the second fiber layer as the content of the polymer phenol compound per unit area of the first fiber layer and the second fiber layer , the content of the polymer phenol compound per unit weight is multiplied by the basis weight measured by the method described later, and converted into the basis weight per unit area. At that time, if the first fiber layer and the second fiber layer contain a material such as a particulate material described later, the water-retentive fiber is cut to a certain fiber length or less as necessary, and a centrifugal separation method or the like is performed. The water-retentive fiber and other materials are separated and classified by weight, density, size, aspect ratio, etc. by a known separation and classification method such as a sieving method, and the content of the high molecular weight phenolic compound is measured. It is also possible to measure the content of the macromolecular phenol compound in the entire fiber layer and the content of the macromolecular phenol compound in the water-retentive fibers contained in each fiber layer.
Regarding the method of measuring the content of polymer phenolic compounds, the properties and materials of water-retaining fibers, the types of polymer phenolic compounds contained and the binding mode of water-retaining fibers, other coexisting fibers/materials and impurities A plurality of measurement methods can be selectively employed depending on the type and amount. Due to differences in measurement methods for high molecular weight phenolic compounds, the content of high molecular weight phenolic compounds in water-retentive fibers and the content of high molecular weight phenolic compounds per unit area in the fiber layer may differ in absolute value. However, as long as the same measurement method is used for the first fiber layer and the second fiber layer, the magnitude relationship of the contents will not be reversed.

The ratio of water-retaining fibers/thermoplastic resin fibers in a sheet such as a fiber layer is measured as follows.
That is, by coloring the water-retentive fibers and the thermoplastic resin fibers with different colors, the ratio of the types of fibers is measured. (1) A sample of 70 mm×70 mm is cut out of the surface sheet 2 . (2) By performing a coloring treatment with the reagent Kayastain Q (Shikisen Co., Ltd.), only the water-retentive fibers are dyed blue, and only the thermoplastic resin fibers are colored yellow. (3) Digital Microscope VHX-100 manufactured by KEYENCE CORPORATION By measuring the ratio of blue and yellow when viewed from the skin side of the sample (first fiber layer 2a) in a range of 50 mm × 50 mm, It is the ratio of the types of fibers in the first fiber layer 2a. On the other hand, by measuring the ratio of blue and yellow when viewed from the non-skin side (second fiber layer 2b) in a range of 50 mm×50 mm, the ratio of the types of fibers in the second fiber layer 2b is obtained.
In addition, when judging the magnitude relationship of the ratio of the types of fibers, if the magnitude relationship of the ratio of blue and yellow is obvious by appearance, it can be judged by appearance, but the magnitude of the ratio of blue and yellow If the relationship cannot be judged by appearance alone, count the number of fibers colored in each color and calculate the total mass of each fiber from the number and the structural characteristics of each fiber (e.g. fiber length, specific gravity, etc.) It can also be determined by calculating and comparing the total mass.

Also, the distance between fibers in a sheet such as a fiber layer is measured according to the following measuring method. (1) A sample of 10 mm×10 mm is cut out of the surface sheet 2 . (2) Using a digital microscope VHX-100 (lens VH-Z20R + variable illumination attachment VH-K20) manufactured by Keyence Corporation, imaging magnification: 200 times, measurement area: vertical 1300 μm × horizontal 1735 μm, surface sheet Images are taken from each of the front surface (first fiber layer 2a) and the rear surface (second fiber layer 2b) of 2. At that time, images are taken five times in total for each depth of 20 μm in the range of 0 μm to 100 μm in depth for each of the front surface and the back surface. (3) From each image obtained, the area of the region where no fiber exists is determined. At that time, the presence or absence of fibers in each pixel is determined based on whether the brightness of each pixel in each obtained image is lower or higher than a predetermined brightness (threshold value). judge. However, light is transmitted only through the area where no fiber exists, and the area is bright, that is, the luminance is high. As a result, the area of the part without fibers in the imaging area is obtained. (4) The void ratio is calculated by subtracting the determined area of the fiber-free site from the area of the imaging region (measured area) and dividing by the area of the imaging region (measured area). The calculation is performed for each 20 μm deep image to calculate five porosities. (5) By calculating the average of the five porosities, the porosities of the front surface (first fiber layer 2a) and the back surface (second fiber layer 2b) of the topsheet 2 are determined. By comparing the size of the porosity, the size of the inter-fiber distance can be determined. That is, when the porosity is large, it can be considered that the inter-fiber distance is large. For example, the surface of the surface sheet 2, that is, the skin side (first fiber layer 2a: for example, cotton 100% surface) has a porosity of 25.4%, and the back surface, that is, the non-skin side (second fiber layer 2b: for example, cotton 60%). + 40% thermoplastic resin fiber surface) had a porosity of 24.5%.

In addition, the fiber length and average fiber length of the fibers of the sheet such as the fiber layer are measured in accordance with "A7.1.1 Method A (standard method ) is measured according to "Method for Measuring the Length of Individual Fibers on a Graduated Glass Plate". The above method is a test method corresponding to ISO 6989 issued in 1981.
In addition, the average fiber length of the water-retaining fiber when the water-retaining fiber is pulp fiber or the like means the weight-weighted average fiber length, and is measured by Kayani Fiber Lab Fiber Properties (offline) manufactured by Metso Automation. means the L(w) value measured by [kajaani FiberLab fiber properties (off-line)].

Also, the basis weight of a sheet such as a fiber layer is measured according to the following measuring method. A single fiber layer is prepared, and the fiber layer is cut into a size of 5 cm x 5 cm to obtain a sample, and the mass is measured after drying in an atmosphere of 100°C or higher. The basis weight of the sample is then calculated by dividing the measured mass by the area of the sample. A value obtained by averaging the grammage of 10 samples is taken as the grammage of the sheet.

Also, the thickness of a sheet such as a fiber layer is measured according to the following measuring method. Using a digital microscope VHX-100 manufactured by KEYENCE CORPORATION, an enlarged image is taken from a direction perpendicular to the cut surface of the surface sheet 2 . The magnified image is an image magnified such that the entirety of the surface sheet 2 in the thickness direction T can be photographed, and the magnification is, for example, 20 to 50 times. The thickness of each fiber layer is measured in the 2D image converted from the obtained 3D image. The thickness of the topsheet 2 is the average value of the thicknesses measured at three separate cut surfaces.

Also, the fiber density of a sheet such as a fiber layer is measured, for example, by the following measuring method.
(1) A sample of 10 mm×10 mm is cut out of the surface sheet 2 . (2) Enlarged observation of a cut surface of the sample parallel to the thickness direction T is performed using a scanning electron microscope (manufactured by JEOL Ltd.: JCM-5100). The magnification is such that the cross section of 30 to 60 fibers can be measured within one screen (example: 150 to 500 times). (3) The observation area is divided into three equal layers in the thickness direction T into a skin-side layer, an intermediate layer, and a non-skin-side layer. With two fiber layers 2b, the number of cross sections of fibers in each fiber layer is measured. That is, the number of cross-sections of the cut fiber is counted on a cut plane of a predetermined area. (4) Convert the number of obtained fiber cross sections into the number of fiber cross sections per 1 mm ² , and take this as the fiber density (fibers/mm ² ). The measurement is performed at three locations, and the average value of the measured values is taken as the fiber density of the sample. That is, the density of the number of fibers is used as the fiber density. In other words, the number of fibers per unit area in a cross section parallel to the thickness direction T is used as the fiber density. As the fiber density, the number of fibers per unit volume may be used. The number of fibers per unit volume can be determined by, for example, X-ray CT analysis. The fiber density per unit area and the fiber density per unit volume have different numerical values, but the relative comparison of the fiber densities between the fiber layers (example: comparison of size) is the same.

In the present embodiment, at least part of the thermoplastic resin fibers of the second fiber layer 2b reaches the vicinity of the skin-side surface of the first fiber layer 2a. That is, at least a part of the thermoplastic resin fibers of the second fiber layer 2b continuously enter the first fiber layer 2a from the second fiber layer 2b while stably maintaining the shape of the second fiber layer 2b. Furthermore, they reach the vicinity of the skin-side surface of the first fiber layer 2a.
In the sanitary napkin 1 having such a configuration, the thermoplastic resin fibers of the second fiber layer 2b continuously extend into the first fiber layer 2a, so that the water-retentive fibers of the first fiber layer 2a are It can be stably held in thermoplastic resin fibers. As a result, even if the strength of the first fiber layer 2a is relatively low, it is possible to suppress the sag. In addition, by holding the water-retaining fibers of the first fiber layer 2a between the thermoplastic resin fibers, it is possible to suppress fluffing. These can improve the feel of the first fiber layer 2a. In addition, since a part of the thermoplastic resin fibers having no water retention property in the second fiber layer 2b is present in the first fiber layer 2a, the second fibers can be separated from the first fiber layer 2a through the thermoplastic resin fibers. Transfer of bodily fluids to layer 2b can be facilitated. Thereby, the body fluid can be stably transferred to the absorbent body 4 (and the auxiliary sheet 5).
In this embodiment, the skin-side surface layer of the first fiber layer 2a is made of only water-retentive fibers, and preferably the skin-side surface is made of 100% organic cotton fibers.

In this embodiment, the fibers forming the topsheet 2 are oriented in the longitudinal direction L of the topsheet 2 at both ends in the width direction W of the topsheet 2 rather than at the central portion in the width direction W of the topsheet 2 . are doing. That is, in the width direction W, in the surface sheet 2, the orientation of the fibers in the central portion in the longitudinal direction L is relatively small, and the orientation of the fibers in the longitudinal direction L is relatively large in the ends.
In the sanitary napkin 1 having such a structure, since the fiber orientation of the topsheet 2 is relatively random in the central portion, the bodily fluid can be diffused substantially concentrically. , the body fluid reaching both ends can be diffused in the longitudinal direction L. That is, the sanitary napkin 1 can be used as a whole, and the absorption performance can be enhanced. In addition, since the number of fibers exposed from the edges is reduced at both ends of the topsheet 2 in the width direction W, the friction against the skin is reduced and the deterioration of the touch can be suppressed. As for the fiber orientation of the surface sheet of the sanitary napkin, the orientation in the longitudinal direction L at both ends in the width direction W does not have to be relatively large.

[Configuration of sanitary napkin]
In the sanitary napkin 1, the excretory opening contact area XA is set at the center in the width direction W near the center in the longitudinal direction L and slightly forward in plan view. The excretory opening contact area XA is an area that faces or contacts the excretory opening of the wearer when the sanitary napkin 1 is worn. The excretory opening contact area XA is set according to the type and application of the absorbent article. The excretory opening contact area XA is, for example, slightly forward from the center of the absorbent body 4 in the longitudinal direction L, and extends from about 1/4 to 1/2 of the total length of the absorbent body 4 in the longitudinal direction L. is set at approximately the center of the absorbent body 4 with a width of about 1/2 to 1/3 of the total length in the width direction W of the absorbent body 4 . When the sanitary napkin 1 is provided with the wing portions 9 , the excretory opening contact area XA may overlap in the width direction W with the installation area of the wing portions 9 in the longitudinal direction L. In addition, the center in the longitudinal direction L and the center in the width direction W of the excretion opening contact area XA are the center in the longitudinal direction L of the area where the wing portions 9 are installed and the center in the width direction W with respect to the width direction outer edges of the two wing portions 9. You may overlap with a line, respectively.

In this embodiment, the sanitary napkin 1 includes a pair of compressed portions (compressed grooves) 12, 12 that are positioned continuously or intermittently on both outer sides in the width direction W of the excretory opening contact area XA. In the present embodiment, the sanitary napkin 1 further includes a pair of compression portions (compression grooves) 13, 13 behind the pair of compression portions 12, 12 in the longitudinal direction L, and the length of the excretory opening contact area XA. Compressed portions (compressed grooves) 11 and 14 are provided on the front and rear sides in the direction L, respectively, and a plurality of dotted compressed portions 15 are provided in the excretory opening contact area XA. The compressed portions 11 to 15 are formed by compressing the top sheet 2 and the absorbent body 4 in the thickness direction T. As shown in FIG. That is, the surface sheet 2, the auxiliary sheet 5, and the absorbent body 4 (the skin-side core wrap 4b and absorbent core 4a) are compressed in the thickness direction T to form. At that time, each pressed part is weakly pressed and formed at a shallow position, and a low density part LPA having a relatively low fiber density and a strongly pressed part LPA formed at a deep position and having a relatively high fiber density and a high density portion HPA. However, the criteria for "shallow" and "deep" are the skin-side surface of the topsheet 2 . The low density LPA and high density HPA can be referred to as the shallow bottom and deep bottom of each squeeze. The low-density portion LPA and the high-density portion HPA of the compressed portions 11-15 are located within the absorbent core 4a. However, the high density portion HP may reach the core wrap 4b on the non-skin side. The shape of the compression parts 11 to 15 is arbitrary. Note that the sanitary napkin may not include at least one of the pressing portions 11-15.

In the present embodiment, at least part of the thermoplastic resin fibers of the second fiber layer 2b are exposed on the inner surface of at least one of the compressed portions 11-15.
In the sanitary napkin 1 having such a configuration, the thermoplastic resin fibers are present in the first fiber layer 2a so as to be exposed on the inner surface of the pressing portion, so that the first fiber layer 2a retains water even in the pressing portion. The elastic fibers can be stably held between the thermoplastic resin fibers. As a result, even if the strength of the first fiber layer 2a is relatively low in the compressed portion, it is possible to prevent the first fiber layer 2a from becoming saggy or fuzzy, and the texture of the first fiber layer 2a in the compressed portion can be improved. can. In addition, since a part of the thermoplastic resin fibers having no water retention property in the second fiber layer 2b is present in the first fiber layer 2a in the compressed portion, the first fibers in the compressed portion through the thermoplastic resin fibers Transfer of bodily fluids from the layer 2a to the second fibrous layer 2b can be facilitated. Thereby, the body fluid can be more stably transferred to the absorbent body 4 (and the auxiliary sheet 5). In the sanitary napkin, the thermoplastic resin fibers do not have to be exposed on the inner surface of the pressing portion.

In this embodiment, at least part of the thermoplastic resin fibers of the second fiber layer 2b is exposed on the surface of the low-density portion LPA of at least one of the compressed portions 11-15.
In the sanitary napkin 1 having such a configuration, the thermoplastic resin fibers are present in the first fiber layer 2a so as to be exposed on the surface of the low-density portion LPA, so that the first fiber layer 2a in the low-density portion LPA is of water-retaining fibers can be stably retained in the thermoplastic resin fibers. As a result, even if the strength of the first fiber layer 2a in the low-density portion LPA is relatively low, it is possible to prevent the first fiber layer 2a in the low-density portion LPA from becoming saggy and fuzzy, thereby improving the feel of the first fiber layer 2a in the low-density portion LPA. be able to. In addition, since a part of the thermoplastic resin fibers that do not retain water in the second fiber layer 2b is present in the first fiber layer 2a in the low-density portion LPA, the low-density portion through the thermoplastic resin fibers Transfer of body fluid from the first fiber layer 2a to the second fiber layer 2b in the LPA can be promoted. Thereby, the bodily fluid can be finally transferred to the absorbent body 4 (and the auxiliary sheet 5) more stably. In the sanitary napkin, the thermoplastic resin fibers do not have to be exposed on the surface of the low-density portion.

(Surface sheet and auxiliary sheet)
In this embodiment, the surface sheet 2 has an uneven structure and is integrated with the auxiliary sheet 5 . 3 is a plan view of the topsheet 2 according to the embodiment, and FIG. 4 is a partially enlarged sectional view of the topsheet 2 and the auxiliary sheet 5 indicated by IV in FIG. 2(a). The first fiber layer 2a has a first upper surface 2aE on the upper side in the thickness direction T and a first lower surface 2aF on the lower side, and the second fiber layer 2b has a second upper surface 2bE on the upper side in the thickness direction T and a lower side and a second lower surface 2bF. The first lower surface 2aF and the second upper surface 2bE are virtual boundaries between the two fiber layers, but they are not strict boundaries because some of the fibers of the two fiber layers are entangled with each other and enter the other fiber layer. The first fiber layer 2a extends continuously along the longitudinal direction L on the first upper surface 2aE. and a plurality of concave portions 22 extending between the convex portions 21 adjacent to each other. Since the topsheet 2 has the protrusions 21 and the recesses 22, the contact area between the topsheet 2 and the skin is reduced, so that the feel of the topsheet 2 is improved. In this embodiment, each of the plurality of protrusions 21 is formed solid. Since each of the plurality of protrusions 21 is formed solid in this manner, each protrusion 21 is less likely to be crushed, and body fluids transfer from each protrusion 21 to the absorbent body 4, which is easily in contact with the wearer's body. Since it has excellent properties, it is possible to improve the dryness of the surface of each projection 21 .

The second fiber layer 2b is slightly raised in the thickness direction T at positions corresponding to the protrusions 21 of the second upper surface 2bE, and is slightly raised in the thickness direction T at positions corresponding to the protrusions 21 of the second lower surface 2bF. Slightly concave upwards. An auxiliary sheet 5, which will be described later, is adhered along the second lower surface 2bF via an adhesive, and the upper surface of the auxiliary sheet 5 is positioned in the thickness direction T at a position corresponding to the convex portion 21. It is in a slightly raised state. That is, in the present embodiment, the top sheet 2 and the auxiliary sheet 5 are integrally formed in such a manner that the non-skin side surfaces of the plurality of projections 21 of the top sheet 2 are fitted with the plurality of projections of the auxiliary sheet 5. is becoming Therefore, since the convex portions 21 of the topsheet 2 are supported by the auxiliary sheet 5, the concave-convex structure of the topsheet 2 is maintained even in a situation where the flexural rigidity of the topsheet 2 itself tends to decrease. In addition, in the sanitary napkin, the second fiber layer may have a substantially flat shape except for depressions (described later) formed by pressing. In addition, the second fiber layer 2b extends continuously along the longitudinal direction L on the second lower surface 2bF in the same manner as the first fiber layer 2a (but in the opposite direction to the thickness direction T), and is spaced apart in the width direction W. and a plurality of recesses extending continuously along the longitudinal direction L and located between adjacent protrusions. In this case, the positions of the projections 21 and the recesses 22 of the first fiber layer 2a and the positions of the projections and the recesses of the second fiber layer 2b are preferably the same in plan view.

The first fiber layer 2a and the second fiber layer 2b are joined to each other by entangling. The entangling method includes, for example, the spunlace method or the water jet method. However, the interlacing method is not limited to this example, and other interlacing methods such as the air-through method may be used.

In this embodiment, the topsheet 2 has a plurality of depressions 23 in the thickness direction T in each of the plurality of recesses 22, where the first fiber layer 2a and the second fiber layer 2b are compressed. The plurality of recessed portions 23 are intermittently arranged along the longitudinal direction L in each recessed portion 22 at equal intervals or non-equidistant intervals. The recessed portions 23 may or may not be located at the same positions in the longitudinal direction L in the recessed portions 22 adjacent to each other in the width direction W. In this embodiment, the recesses 22 are arranged in a checkered pattern. Moreover, the shape of the recessed portion 23 in plan view is arbitrary, such as an elliptical shape.
In the sanitary napkin 1 having such a configuration, the first fiber layer 2 and the second fiber layer 2b are fixed by compression in the thickness direction T in the plurality of depressions 23, and thus the first fiber layer retains water. Compressed fibres. As a result, fluffing of the water-retentive fibers can be suppressed, and the texture of the topsheet can be maintained satisfactorily. In addition, the sanitary napkin does not have to have the recesses 23 in the topsheet.

In this embodiment, the surface sheet 2 comprises a particulate material having a high polymer phenolic compound content compared to water retentive fibers. The water repellency of the topsheet 2 is at least partially enhanced by providing the topsheet 2 with such a particulate material rich in high-molecular-weight phenolic compounds, thereby enhancing the dryness of the topsheet. Particulate materials rich in high molecular weight phenolic compounds can include lignin-rich plant fragments. For example, when cotton fibers are used as the water-retentive fibers, the particulate material rich in high-molecular-weight phenolic compounds can include cottonseed seed husks.
It should be noted that the sanitary napkin need not comprise particulate material rich in polymeric phenolic compounds.

In this embodiment, the auxiliary sheet 5 is a liquid-permeable sheet. Examples of the auxiliary sheet 5 include liquid-permeable nonwoven fabrics, woven fabrics, and composite sheets thereof. The dimension in the width direction W of the auxiliary sheet 5 is larger than the dimension in the width direction W of the topsheet 2 . That is, the auxiliary sheet 5 has a slightly larger shape in the width direction W than the top sheet 2 . The auxiliary sheet 5 has a pair of loop portions 5L, 5L at both ends in the width direction W. As shown in FIG. Both sides of the auxiliary sheet 5 in the width direction W of the pair of loop parts 5L and 5L are folded back in a loop shape to the inside of the auxiliary sheet 5 in the width direction W and to the non-skin side (lower side in the thickness direction T). formed by The ends of both sides of the folded-back auxiliary sheet 5 are attached to a pair of inner ends of the pair of side sheets 6, 6 facing each other along the longitudinal direction L. ) are joined to each other. Note that the loop portion 5L does not include an elastic member. Further, the ends of both sides of the folded back auxiliary sheet 5 are joined to the non-skin side surface of the auxiliary sheet 5 by a pair of adhesive portions extending intermittently or continuously along the longitudinal direction L. As shown in FIG.

In the surface sheet 2 of the present embodiment containing a large amount of water-retaining fibers, when the edges are rubbed, the water-retaining fibers are likely to come loose and fall off from the edges. Here, in the present embodiment, the dimension in the width direction W of the auxiliary sheet 5 is larger than the dimension in the width direction W of the top sheet 2 . That is, in a plan view, portions of the auxiliary sheet 5 outside both edges in the width direction W of the top sheet 2 extend outward in the width direction W to form a pair of extension portions. In this embodiment, a pair of loop portions 5L, 5L are formed at both end portions of the auxiliary sheet 5 in the width direction W as the pair of extending portions. As a result, the force that the sanitary napkin 1 receives from the thighs of the wearer can be received by the pair of loop portions 5L, 5L (the pair of extension portions), and both edges of the topsheet 2 in the width direction W It is possible to make it difficult to rub against the thighs. As a result, it is possible to prevent the water-retentive fibers from being frayed and dropped from both edges in the width direction W of the topsheet 2 due to rubbing at both edges in the width direction W of the topsheet 2, thereby suppressing a decrease in touch feeling. In particular, when the pair of loop portions 5L and 5L are used as the pair of extension portions, the force that the sanitary napkin 1 receives from the wearer's thighs is softly received by the pair of loop portions 5L and 5L. The texture felt by the wearer can be improved. Especially when the water-retentive fibers are cotton fibers, these effects are remarkable.

In this embodiment, the auxiliary sheet 5 has a fiber density higher than that of the second fiber layer 2b. In the sanitary napkin 1 having such a configuration, body fluid drawn into the second fiber layer 2b can be stably transferred to the auxiliary sheet 5 by capillary force. As a result, body fluid can be more stably transferred from the topsheet 2 to the absorbent body 4 via the auxiliary sheet 5, and the absorption performance can be improved while the touch of the topsheet 2 is improved. In addition, when the fiber density of the first fiber layer 2a<the fiber density of the second fiber layer 2b<the fiber density of the auxiliary sheet 5, body fluids are more stably transferred to the auxiliary sheet 5 by capillary force. It is transferable and preferred. In the sanitary napkin, the fiber density of the auxiliary sheet may be the same as the fiber density of the second fiber layer or may be lower than the fiber density of the second fiber layer. 5L may not be provided.

In the present embodiment, both edges in the width direction W of the topsheet 2 are not joined to the auxiliary sheet 5, and both edges in the width direction W of the topsheet 2 are slightly separated from the auxiliary sheet 5. It is standing up. As a result, the portions including both edges of the topsheet 2 constitute the wall surface, thereby effectively preventing body fluid from leaking along the width direction. The sanitary napkin may have both edges in the width direction W of the surface sheet joined to the auxiliary sheet.

In this embodiment, the auxiliary sheet 5 contains water-retentive fibers corresponding to the topsheet 2, and when the topsheet 2 contains cellulose fibers (preferably cotton fibers), cellulose fibers (preferably cotton fibers) ) is preferably included. In the sanitary napkin 1 having such a structure, water-retentive fibers with high liquid diffusibility, preferably cellulosic fibers, more preferably cotton fibers, extend from the first fiber layer of the top sheet 2 to the auxiliary sheet through the second fiber layer. 5 are connected. Therefore, by utilizing the diffusion of body fluids by these fibers, the body fluids can be more stably transferred from the topsheet 2 to the absorbent body 4 via the auxiliary sheet 5, and the touch of the topsheet 2 can be improved. , the absorption performance can be improved. In the sanitary napkin, the auxiliary sheet may not contain water-retentive fibers, cellulosic fibers or cotton fibers. In this case, the auxiliary sheet may be, for example, a nonwoven fabric made of hydrophobic fibers, and among them, a nonwoven fabric made of thermoplastic resin fibers is preferably used.

The absorbent body 4 is a layer having liquid absorption performance and liquid retention performance, and in the present embodiment, it has a shape elongated in the longitudinal direction L in plan view and having substantially semicircular ends in the longitudinal direction L. As shown in FIG. In this embodiment, the absorbent body 4 includes an absorbent core 4a and a core wrap 4b covering it. The absorbent core 4a includes, for example, a liquid-retaining substance containing water-absorbing fibers such as pulp fibers, and a water-absorbing material such as superabsorbent polymer (SAP). The core wrap 4b may be, for example, a liquid-permeable sheet containing a hydrophilic nonwoven fabric such as tissue.

In this embodiment, when the topsheet 2 contains cellulosic fibers (preferably cotton fibers), the absorber 4 preferably contains cellulosic fibers (preferably cotton fibers) corresponding to the topsheet 2 . . In that case, part of the cellulosic fibers contained in the topsheet 2 is preferably in contact with the cellulosic fibers contained in the absorbent body 4 .
In the sanitary napkin 1 having such a structure, the cellulose-based fibers with high liquid diffusibility pass from the first fiber layer 2a of the top sheet 2 through the second fiber layer 2b (in some cases, through the auxiliary sheet 5). It communicates up to the absorber 4 . Therefore, body fluid can be directly diffused from the topsheet 2 to the absorbent body 4 by utilizing the liquid diffusion of the body fluid by the cellulosic fibers. Thereby, absorption performance can be improved. In addition, the sanitary napkin does not have to include cellulosic fibers or cotton fibers in the absorbent.

(side sheet, back sheet)
In this embodiment, the side sheet 6 is a hydrophilic sheet. Examples of the side sheet 6 include a hydrophilic nonwoven fabric and a breathable synthetic resin film. Further, in this embodiment, the backsheet 3 is a liquid-impermeable sheet. Examples of the backsheet 3 include liquid-impermeable nonwoven fabrics, synthetic resin films, and composite sheets thereof. In this embodiment, the wing portions 9 are formed by the side sheets 6 and the back sheet 3 .

In the sanitary napkin 1 of the present embodiment, as described above, the top sheet 2 is joined to the auxiliary sheet 5 with an adhesive (example: hot-melt adhesive), and the absorbent members in the auxiliary sheet 5 and the pair of side sheets 6, 6 The part facing 4 is joined to the absorbent body 4 with an adhesive. The portions of the pair of side sheets 6, 6 and the absorbent body 4 facing the backsheet 3 are joined to the backsheet 3 with an adhesive or the like.

In this embodiment, the sanitary napkin 1 further includes a plurality of adhesive portions 7 and a pair of adhesive portions 8,8. The plurality of adhesive portions 7 have, for example, a substantially rectangular shape, are arranged on the non-skin side surface of the backsheet 3 so as to overlap the absorber 4 in plan view, extend continuously in the longitudinal direction L, and extend in the width direction. Lined up intermittently on W. The pair of adhesive portions 8, 8 has, for example, a substantially rectangular shape, is arranged on the non-skin side surface of the backsheet 3 so as to overlap with the pair of wing portions 9, 9 in plan view, and is continuous in the longitudinal direction L. extended. As the adhesive parts 7 and 8, for example, a hot melt adhesive can be used.

<Manufacturing method of sanitary napkin>
Next, an example of a method for manufacturing the sanitary napkin 1 according to this embodiment will be described.

FIG. 6 is a schematic diagram showing a configuration example of a manufacturing apparatus 300 for the sanitary napkin 1. As shown in FIG. 7A and 7B are diagrams schematically illustrating a method for manufacturing the sanitary napkin 1. FIG. The manufacturing apparatus 300 has a transport direction MD, a transverse direction CD, and a vertical direction TD for transporting materials such as sheets and semi-finished products. In this embodiment, the longitudinal direction, width direction and thickness direction of the materials and semi-finished products are all the same as the transport direction MD, the transverse direction CD and the vertical direction TD.

First, the first carding machine 110 forms the second fiber web P11 corresponding to the second fiber layer 2b. The first carder 110 is a dry roller card using a single card or double card commonly used for forming fibrous webs. The second fibrous web P11 contains second water-retentive fibers and thermoplastic resin fibers. The second fibrous web P11 is conveyed in the conveying direction MD by a conveying device (not shown).
Next, the second carding machine 120 forms the first fiber web P12 corresponding to the first fiber layer 2a. The second carding machine 120 is also a dry roller card similar to the first carding machine 110 . The first fibrous web P12 contains first water-retentive fibers. The first fibrous web P12 is laminated on the second fibrous web P11 being conveyed by the conveying device. As a result, a composite fiber web P13 having a two-layer structure in which the first fiber web P12 and the second fiber web P11 are laminated is formed, and is transported in the transport direction MD by the transport device. The ratio of each fiber in each fiber web can be controlled by the ratio of raw material fibers supplied to each carding machine.

Next, the composite fiber web P13 having a two-layer structure is subjected to water jet treatment by a water jet treatment machine 130 to entangle the fibers. Thereby, a first continuous sheet (spunlaced nonwoven fabric) P14 is formed. Here, in the water jet treatment, the composite fiber web P13 is placed on a continuously moving mesh belt, and a high-pressure water jet is jetted from the upper surface side of the composite fiber web P13 to entangle the fibers. The properties of the first continuous sheet P14 obtained by the water jet treatment can be appropriately adjusted and changed by the mass of each fiber web, the hole diameter of the injection nozzle, the number of holes (pitch) of the injection nozzle, the passing speed of the fiber web, and the like. . After that, the first continuous sheet P14 that has passed through the water jet processor 130 is dried by the dryer 140 . The dried first continuous sheet P15 is transported in the transport direction MD by the transport device.

The method for forming the fiber web corresponding to each fiber layer is not limited to the method described above, and for example, a wet method may be employed. Also, the web bonding method is not limited to the method described above, and for example, a hydroentanglement method, a needle punch method, or the like may be employed. Further, the first continuous sheet P15 is manufactured in a manufacturing factory different from the manufacturing factory of the sanitary napkin 1, wound into a roll, and then supplied in the state of a roll to the manufacturing factory of the sanitary napkin 1. good too.

Next, the first continuous sheet P16, which is the first continuous sheet P15 transported by a transport device (not shown) or rewound from a roll (not shown), is transported in the transport direction MD and shaped. It is supplied to device 210 . Here, the shaping device 210 includes shaping rolls 210a and 210b having uneven portions extending in the circumferential direction and meshing with each other on the outer peripheral surface. Then, the first continuous sheet P16 is nipped between the uneven portions of the shaping rolls 210a and 210b to be shaped into an uneven structure extending in the transport direction MD. After that, the first continuous sheet P16 is transported in the transport direction MD. Thereby, a continuous topsheet P16 for the topsheet 2 is formed.

Next, the continuous auxiliary sheet AS for the auxiliary sheet 5 unwound from the material roll WR3 is supplied to the heating device 220 while being transported in the transport direction MD. Next, the continuous auxiliary sheet AS is supplied to the coating device 302 after undergoing a heat treatment to restore bulk. One surface of the continuous auxiliary sheet AS is coated with an adhesive (example: hot-melt adhesive) in a predetermined pattern (example: spiral pattern). After that, the continuous auxiliary sheet AS and the continuous topsheet P16 are supplied to the joining device 230 while being transported in the transport direction MD, and sandwiched between a pair of joining rolls 230a and 230b of the joining device 230 to be joined. Thereby, a continuous surface sheet P17 is formed as shown in FIG. 7(a).
In the present embodiment, in order to realize a configuration in which the plurality of projections 21 of the auxiliary sheet 5 are fitted to the non-skin side surfaces of the plurality of projections 21 of the topsheet 2, the bonding device 230 must be provided. The joining roll 230b constitutes an embossing roll, and the joining roll 230a constitutes an anvil roll. do it.

Next, the continuous surface sheet P17 is supplied to the coating device 303 while being transported in the transport direction MD. Then, the continuous surface sheet P17 is applied with an adhesive (for example, hot melt adhesive agent) is applied in a predetermined pattern. Next, the continuous surface sheet P17 is supplied to the loop forming device 240 while being transported in the transport direction MD. Both end portions of the continuous auxiliary sheet AS of the continuous surface sheet P17 in the transverse direction CD are folded toward the central portion in a loop shape by a folding jig such as a sailor of the loop forming device 240 . As a result, a pair of side portions ASL, ASL corresponding to the pair of loop portions 5L, 5L are formed on both sides of the continuous surface sheet P17 in the transverse direction CD. Thereby, a continuous surface sheet P18 is formed as shown in FIG. 7(b).

Next, the continuous side sheet SS for the side sheet 6 unwound from the material roll WR4 is supplied to the cutting device 250 while being transported in the transport direction MD. Then, the continuous side sheet SS is cut into two halves in the transverse direction CD along the transport direction MD at the center position in the transverse direction CD to form a pair of continuous side sheets SSa and SSb adjacent to each other in the transverse direction CD. be done. After that, a pair of continuous side sheets SSa, SSb are supplied to a pair of coating devices 304a, 304b. Each of the pair of continuous side sheets SSa and SSb is coated with an adhesive (eg, hot-melt adhesive) in a predetermined pattern (eg, stripe pattern) on the inner edge in the transverse direction CD. Next, the pair of continuous side sheets SSa, SSb and the continuous top sheet P8 are supplied to the joining device 260 while being transported in the transporting direction MD, and sandwiched between the pair of joining rolls 260a, 260b of the joining device 260, spliced. Thereby, the pair of side portions ASL, ASL of the continuous surface sheet P18 and the pair of continuous side sheets SSa, SSb are respectively joined. Thereby, a continuous topsheet P2 is formed as shown in FIG. 7(c).

Next, the continuous topsheet P2 is supplied to the applicator 305, and an adhesive (example: hot-melt adhesive) is applied in a predetermined pattern on the side closer to the pair of continuous side sheets SSa and SSb. Next, the continuous surface sheet P2 and the absorbers P3 arranged in the transport direction MD at predetermined intervals are supplied to the joining device 270 while being transported in the transport direction MD. Then, the continuous surface sheet P2 and the absorbent body P3 are sandwiched between a pair of joining rolls 270a and 270b of the joining device 270 and joined. Thereby, a semi-finished product P4 is formed. Subsequently, the semi-finished product P4 is supplied to the pressing device 280 while being transported in the transport direction MD. In the pressing device 280, an embossing roll 280a having a convex portion for pressing on its outer peripheral surface and an anvil roll 280b are arranged to face each other. The semi-finished product P4 is sandwiched between the embossing roll 280a and the anvil roll 280b and squeezed. As a result, compressed portions 11 to 15 extending from the continuous surface sheet P2 to the absorbent body P3 are formed in the vertical direction TD, thereby forming the semi-finished product P5. In addition, each pressing part may be pressed by a mutually different pressing apparatus. Next, the continuous backsheet BS for the backsheet 3 is fed from the fourth material roll WR5 to the joining device 290 while being transported in the transport direction MD. One surface of the continuous backsheet BS is coated with an adhesive (example: hot-melt adhesive) by a coating device 306 . On the other hand, the semi-finished product P5 is supplied to the joining device 290 while being transported in the transport direction MD. Then, the continuous backsheet BS and the semi-finished product P5 are sandwiched between a pair of joining rolls 290a and 290b of the joining device 290 and joined. As a result, as shown in FIG. 7(d), the semi-finished product P6 is formed by laminating the continuous backsheet BS and the semi-finished product P5 in the vertical direction TD. Thereafter, a release sheet CT (adhesive portions 7 and 8) with an adhesive is attached to the semi-finished product P6. A napkin 1 is formed.

As described above, the sanitary napkin 1 is manufactured.

However, as a method for interlacing the composite fiber web P13 having a two-layer structure, an air-through method may be used. That is, it is a method in which the composite fiber web P13 is transported to a heating device, and the fibers of the composite fiber web P13 are entangled with heated air in the heating device.

The absorbent article of the present invention is not limited to the above-described embodiments, and can be appropriately combined and modified without departing from the scope and spirit of the present invention.

1 sanitary napkin (absorbent article)
2 surface sheet 2a first fiber layer 2b second fiber layer

Claims (8)

An absorbent article comprising a topsheet having a skin side and a non-skin side, a backsheet, and an absorbent body positioned between the topsheet and the backsheet,
The surface sheet is
A first fiber layer forming the skin side, and a second fiber layer adjacent to the non-skin side of the first fiber layer and forming the non-skin side,
each of the first fiber layer and the second fiber layer comprises a water-retentive fiber;
The content of polyphenols in the water-retaining fibers in the second fiber layer is greater than the content of polyphenols in the water-retaining fibers in the first fiber layer,
At least the second fiber layer contains thermoplastic resin fibers,
The amount of thermoplastic resin fibers present in the second fiber layer is greater than the amount of thermoplastic resin fibers present in the first fiber layer,
at least a portion of the water-retentive fibers contained in the first fiber layer are coated with a molten thermoplastic resin;
At least some of the water-retentive fibers are coated with the melt of the thermoplastic resin in at least some of the entangled portions of the fibers,
The proportion of the entangled portions covered with the molten thermoplastic resin in the second fiber layer is compared to the proportion of the entangled portions covered with the molten thermoplastic resin in the first fiber layer. and large, absorbent articles. An absorbent article comprising a topsheet having a skin side and a non-skin side, a backsheet, and an absorbent body positioned between the topsheet and the backsheet,
The surface sheet is
A first fiber layer forming the skin side, and a second fiber layer adjacent to the non-skin side of the first fiber layer and forming the non-skin side,
each of the first fiber layer and the second fiber layer comprises a water-retentive fiber;
The content of polyphenols in the water-retaining fibers in the second fiber layer is greater than the content of polyphenols in the water-retaining fibers in the first fiber layer,
Each of the first fiber layer and the second fiber layer contains, as water-retaining fibers, first water-retaining fibers and second water-retaining fibers,
The content of polyphenols in the first water-retaining fibers is greater than the content of polyphenols in the second water-retaining fibers,
The amount of the second water-retaining fibers in the first fiber layer is greater than the amount of the second water-retaining fibers in the second fiber layer,
The absorbent article, wherein the abundance of the first water-retaining fibers in the second fibrous layer is greater than the abundance of the first water-retaining fibers in the first fibrous layer. An absorbent article comprising a topsheet having a skin side and a non-skin side, a backsheet, and an absorbent body positioned between the topsheet and the backsheet,
The surface sheet is
A first fiber layer forming the skin side, and a second fiber layer adjacent to the non-skin side of the first fiber layer and forming the non-skin side,
each of the first fiber layer and the second fiber layer comprises a water-retentive fiber;
The content of polyphenols in the water-retaining fibers in the second fiber layer is greater than the content of polyphenols in the water-retaining fibers in the first fiber layer,
An auxiliary sheet is provided between the surface sheet and the absorbent body,
The surface sheet and the auxiliary sheet are
a plurality of protrusions extending along the longitudinal direction of the absorbent article and positioned at intervals in the width direction of the absorbent article;
a plurality of recesses extending along the longitudinal direction of the absorbent article and positioned between adjacent protrusions;
and the plurality of protrusions of the auxiliary sheet are fitted to the non-skin surface of the plurality of protrusions of the topsheet,
The widthwise dimension of the top sheet is smaller than the widthwise dimension of the auxiliary sheet,
The absorbent article, wherein the edges of the topsheet in the width direction are not joined to the auxiliary sheet. 4. The absorbent article according to any one of claims 1 to 3, wherein the fiber length of said thermoplastic resin fibers is longer than the fiber length of said water-retentive fibers. The absorbent article according to any one of claims 1 to 4, wherein the thermoplastic resin fibers are core-sheath type conjugate fibers, and the melting point of the sheath component is lower than the melting point of the core component. The fiber density of the second fiber layer is higher than the fiber density of the first fiber layer,
The absorbent article according to any one of claims 1-5. 7. An absorbent article according to any preceding claim, wherein the average distance between fibers of the second fibrous layer is smaller than the average distance between fibers of the first fibrous layer. 8. The absorbent article according to any one of claims 1 to 7, wherein said topsheet comprises a particulate material having a high content of polyphenols compared to said water-retentive fibers.

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