JP2019198620A - Absorbent article - Google Patents

Abstract

To provide an absorbent article comprising a top sheet which hardly gives uncomfortable stimulation to the skin of a wearer, and is agreeable to the touch.SOLUTION: There is provided an absorbent article. In the absorbent article, a top sheet (2) includes: a first fiber layer (2a) containing water retaining fibers (F), and forming a surface at a skin side of the top sheet (2); and a second fiber layer (2b) containing thermoplastic resin fibers (F) and the water retaining fibers (F), and forming a surface at a non-skin side of the top sheet (2) adjacently to a non-skin side of the first fiber layer (2a). A ratio of the water retaining fibers (F) in the fibers constituting the first fiber layer (2a) is larger than a ratio of the water retaining fibers (F) in the fibers constituting the second fiber layer (2b). At least a part of the water retaining fibers (F) contained in the first fiber layer (2a) is coated by a molten material (F) of the thermoplastic resin fibers (F), in at least a part of an entanglement part (P) in entanglement parts (P) of the fibers.SELECTED DRAWING: Figure 3

Description

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

  As a surface sheet used for an absorbent article such as a sanitary napkin, a sheet containing water-retaining fibers that absorb and retain moisture such as cotton fiber is known. For example, Patent Document 1 discloses an absorbent article. As a non-woven fabric that can be used as a surface material, a bleached cotton fiber (cotton fiber) to which natural fats and oils are attached and a thermoplastic short fiber having at least a fiber surface made of an olefin polymer, the constituent fibers are three-dimensionally formed. A non-woven fabric entangled is disclosed. According to the nonwoven fabric disclosed in Patent Document 1, it can be suitably used in a field where a conventional nonwoven fabric made of absorbent cotton fibers such as a surface material of an absorbent article has not been used.

JP 2005-139594 A

  However, as with the nonwoven fabric disclosed in Patent Document 1, the skin of the wearer's crotch and its surroundings can be obtained only by interlacing cotton fibers (water-retaining fibers) and thermoplastic short fibers (thermoplastic resin fibers). When used as a surface sheet of an absorbent article that is in direct contact with (i.e., the skin where it is easy to perceive irritation), the thermoplastic resin fibers contained in the nonwoven fabric feel irritating to the wearer's skin. It is easy to give unpleasant irritation such as tingling and tingling, and during use of the absorbent article, the interlacing of fibers due to friction with the wearer's skin etc. is loosened, and the water retention fiber breaks As a result, fluffing of the water-retaining fibers occurs on the skin side surface of the topsheet, and the fluffing may cause unpleasant stimulation to the wearer's skin.

  Then, an object of this invention is to provide the absorptive article containing the surface sheet excellent in the touch which is hard to give an unpleasant irritation | stimulation to a wearer's skin.

One aspect (aspect 1) of the present invention is an absorbent article including a surface sheet,
The surface sheet is
A first fiber layer containing water retention fibers and forming a skin side surface of the top sheet;
A second fiber layer that includes a thermoplastic resin fiber and a water retention fiber and forms a non-skin side surface of the top sheet adjacent to the non-skin side of the first fiber layer;
With
The ratio of the water retention fiber in the fibers constituting the first fiber layer is greater than the ratio of the water retention fiber in the fibers constituting the second fiber layer,
At least a part of the water-retaining fibers contained in the first fiber layer is covered with a melt of the thermoplastic resin fiber in at least a part of the entangled part of the fibers. It is an absorbent article.

In the absorbent article of this aspect, the ratio of the water retention fiber of the first fiber layer in the top sheet is higher than the ratio of the water retention fiber of the second fiber layer, and the thermoplastic resin contained in the second fiber layer Since at least a part of the fibers is a melt that covers the water-retaining fibers in at least some of the entangled portions of the fibers included in the first fiber layer, the surface sheet is a thermoplastic resin. Even if it contains fibers, the thermoplastic resin fibers are less likely to come into contact with the wearer's skin, and it is possible to make it difficult for the wearer to be given unpleasant stimuli such as an irritating feel or an irritating feel.
Further, in the absorbent article according to this aspect, at least a part of the water retaining fibers contained in the first fiber layer is coated with a melt of thermoplastic resin fibers at least a part of the entangled part of the fibers. As a result, the entanglement between the fibers in the surface sheet is less likely to be loosened, and the water retention fiber is less likely to break, so that the water retention fiber fuzz due to the loosening of the entanglement and the breakage of the water retention fiber Can be made difficult to cause unpleasant stimulation caused by the fluff.
Therefore, the absorbent article of this aspect can realize an absorbent article that includes a surface sheet that is less likely to give unpleasant stimulation to the wearer's skin and that is excellent in touch.

  Moreover, in another aspect (aspect 2) of the present invention, in the absorbent article of aspect 1, the thermoplastic resin fiber is entangled with a plurality of the water-retaining fibers. Each of the entangled portions of the one thermoplastic resin fiber and the plurality of water retaining fibers is covered with a melt of the one thermoplastic resin fiber.

  The absorbent article of this aspect has a plurality of entangled portions of one thermoplastic resin fiber and a plurality of water retention fibers covered with a melt of one thermoplastic resin fiber. Since the water-retaining fibers are connected through a single thermoplastic resin fiber, it is possible to make it more difficult to generate fuzz due to the above-mentioned loosening of the entanglement and breakage of the water-retaining fibers.

  In still another aspect (Aspect 3) of the present invention, in the absorbent article according to Aspect 1 or 2, the melt of the thermoplastic resin fiber is not exposed on the skin side surface of the first fiber layer.

  In the absorbent article of this aspect, since the melt of the thermoplastic resin fibers is not exposed on the skin side surface of the first fiber layer, the presence of the melt is not easily perceived by the wearer, and the surface sheet is good. You can get a certain touch more reliably.

  In still another aspect (Aspect 4) of the present invention, in the absorbent article according to any one of Aspects 1 to 3, at least an average fiber length of the water-retaining fibers contained in the first fiber layer is the thermoplastic resin. It is shorter than the average fiber length of the fiber.

  The absorbent article of this aspect is contained in the second fiber layer because the average fiber length of the water-retaining fibers contained in the first fiber layer is shorter than the average fiber length of the thermoplastic resin fibers contained in the second fiber layer. Since the number of water-retaining fibers in the first fiber layer in contact with the one thermoplastic resin fiber is increased, the adhesion amount of the thermoplastic resin fiber melt per one water-retaining fiber can be increased, It is possible to make the above-mentioned water retention fiber fluff less likely to occur.

  In still another aspect (Aspect 5) of the present invention, in the absorbent article according to any one of Aspects 1 to 4, the average fiber length of the water-retaining fibers contained in at least the first fiber layer is 5 mm or more and less than 35 mm. is there.

  In the absorbent article of the present aspect, since the average fiber length of the water-retaining fibers contained in the first fiber layer is within the specific range, the water-retaining fibers described above are less likely to cause fuzz. It is easy to maintain flexibility and texture, and as a result, the touch of the surface sheet can be improved.

  In still another aspect (Aspect 6) of the present invention, in the absorbent article according to any one of Aspects 1 to 5, the thermoplastic resin fiber is a composite fiber, and the composite fiber has a resin component having a low melting point. It is exposed on the surface of the composite fiber.

In the absorbent article of this embodiment, since the thermoplastic resin fiber is a composite fiber, the resin component having a low melting point exposed on the fiber surface (for example, in the case of a core-sheath type composite fiber, the resin component constituting the sheath, side In the case of a bi-side type composite fiber, the resin component on one side is melted to coat the water retaining fiber, while the resin component having a high melting point (for example, in the case of a core-sheath type composite fiber, the resin component constituting the core part) In the case of a side-by-side type composite fiber, the resin component on the other side) can be kept entangled with water-retaining fibers and other composite fibers, and a predetermined bulk can be maintained as a surface sheet. .
Thereby, the absorbent article of this aspect is easy to ensure the softness | flexibility, texture, cushioning property, etc. with a favorable surface sheet, making it difficult to produce the fuzz of the above-mentioned water retention fiber.

  In still another aspect (Aspect 7) of the present invention, in the absorbent article according to any one of Aspects 1 to 6, the topsheet has a squeezed portion that is recessed in the thickness direction from the skin-side surface.

  Since the absorbent article of this aspect has the pressing part in which the surface sheet was formed by the embossing etc., the said pressing part hold | maintains a water retention fiber, and makes the above-mentioned water retention fiber fluff more difficult to produce. be able to.

  In still another aspect (aspect 8) of the present invention, in the absorbent article according to any one of aspects 1 to 7, the top sheet extends along a longitudinal direction of the absorbent article, and the absorbent article. There are a plurality of convex portions located at intervals in the width direction, and a plurality of concave portions extending along the longitudinal direction of the absorbent article and located between the convex portions adjacent to each other.

  In the absorbent article of this aspect, since the surface sheet has the above-described specific uneven structure, the contact area between the skin side surface of the surface sheet and the skin of the wearer is reduced. It is possible to further reduce the possibility that unpleasant irritation caused by the fuzz of the thermoplastic resin fibers and water-retaining fibers contained is imparted to the wearer's skin.

  In still another aspect (Aspect 9) of the present invention, in the absorbent article according to Aspect 8, the absorbent article further includes an auxiliary sheet positioned on the non-skin side of the top sheet, and the top sheet includes the top sheet Each of the plurality of recesses is joined to the auxiliary sheet.

  In the absorbent article of this aspect, since the top sheet is bonded to the auxiliary sheet in each of the plurality of recesses, the bonded portion with the auxiliary sheet holds the water-retaining fibers, and the above-described water-retaining fibers are more fuzzy. It can be made difficult to occur.

  In still another aspect (Aspect 10) of the present invention, in the absorbent article according to any one of Aspects 1 to 9, the water retention fiber is organic cotton.

Since the absorbent article of this embodiment is an organic cotton whose water retention fiber is excellent in flexibility, texture, etc., the surface sheet can easily ensure good flexibility, texture, etc., and can realize a better touch. it can.
Moreover, when the topsheet contains such organic cotton, there is an advantage that a sense of security can be nurtured by using a natural material for the topsheet for the wearer of the absorbent article. .

  In still another aspect (Aspect 11) of the present invention, in the absorbent article according to any one of Aspects 1 to 10, the fiber density of the second fiber layer is larger than the fiber density of the first fiber layer.

In the absorbent article according to this aspect, the fibers constituting the second fiber layer are close to each other because the fiber density of the second fiber layer is greater than the fiber density of the first fiber layer, and the second fiber layer Capillarity can be generated more strongly in the liquid, so that the liquid excretion excreted on the skin side surface of the top sheet (that is, the skin side surface of the first fiber layer) can be quickly drawn into the second fiber layer. In addition, the liquid excrement drawn into the second fiber layer can be quickly transferred to the non-skin side of the second fiber layer by the thermoplastic resin fiber.
Thereby, the absorptive article of this mode can secure good absorption performance, making the surface sheet excellent in touch.

  In still another aspect (Aspect 12) of the present invention, in the absorbent article according to any one of Aspects 1 to 11, the average distance between the fibers of the second fiber layer is between the fibers of the first fiber layer. Shorter than the average distance.

In the absorbent article of this aspect, the average distance between the fibers of the second fiber layer is shorter than the average distance between the fibers of the first fiber layer, so that the fibers constituting the second fiber layer are close to each other. In addition, since the capillary phenomenon can be generated more strongly in the second fiber layer, the liquid excretion excreted on the skin side surface of the first fiber layer can be quickly drawn into the second fiber layer. The liquid excrement drawn into the two-fiber layer can be quickly transferred to the non-skin side of the second fiber layer by the thermoplastic resin fiber.
Thereby, the absorptive article of this mode can secure good absorption performance, making the surface sheet excellent in touch.

  In still another aspect (Aspect 13) of the present invention, in the absorbent article according to any one of Aspects 1 to 12, the absorbent article is located on the skin side of the topsheet at both ends in the width direction. Further, the pair of side sheets has a wet dynamic friction coefficient lower than the wet dynamic friction coefficient of the top sheet.

  In the absorbent article of this aspect, the pair of side sheets that are easy to touch the skin around the wearer's legs has a lower coefficient of dynamic friction than the surface sheet that is excellent in the touch. Can be provided.

  ADVANTAGE OF THE INVENTION According to this invention, the absorbent article containing the surface sheet excellent in the touch which is hard to give an unpleasant irritation | stimulation to a wearer's skin can be provided.

FIG. 1 is a plan view of a sanitary napkin 1 according to an embodiment of the present invention as viewed in the thickness direction T from the topsheet 2 side in the unfolded state. FIG. 2 is a cross-sectional view taken along the line II-II of the sanitary napkin 1 in FIG. FIG. 3 is an enlarged schematic view of the main part of the first fiber layer 2a in the topsheet 2. FIG. 4A is an enlarged plan view of the top sheet 2, and FIG. 4B is a cross-sectional view taken along the line IVb-IVb of the top sheet 2 in FIG. FIG. 5 is an electron micrograph of the first fiber layer in the top sheet of Example 1 of the present invention. FIG. 6 is a comparative photograph showing the occurrence of fluffing between Example 1 of the present invention and Comparative Examples 1 and 2.

  Hereinafter, preferred embodiments of the absorbent article of the present invention will be described in detail with reference to the drawings. In this specification, unless otherwise specified, “an object placed on a horizontal surface in an unfolded state (for example, a sanitary napkin (absorbent article) or the like) is placed from above in the vertical direction. “Viewing in the thickness direction” is simply referred to as “plan view”.

FIG. 1 is a plan view of a sanitary napkin 1 according to an embodiment of the present invention as viewed in the thickness direction T from the top sheet 2 side in the unfolded state, and FIG. 2 is a sanitary napkin 1 in FIG. It is sectional drawing along the II-II line.
The sanitary napkin 1 of this embodiment has the longitudinal direction L, the width direction W, and the thickness direction T which are orthogonal to each other as shown in FIGS. 1 and 2, and further passes through the center of the width direction W. In addition, it has a longitudinal center line C _L (virtual line) extending in the longitudinal direction L and a width direction center line C _W (imaginary line) passing through the center of the longitudinal direction L and extending in the width direction _W.

In the present specification, in the longitudinal direction L of the sanitary napkin 1, the relatively proximal called inner side of the longitudinal direction L, the width-direction center line C _W the width direction center line C _W On the other hand, the relatively distal side is referred to as the outer side in the longitudinal direction L. Similarly, in the width direction W of the sanitary napkin 1, referred to as inner side in the width direction W relatively proximal to the longitudinal center line C _L, relative to the longitudinal center line C _L The distal side is referred to as the outer side in the width direction W.
Further, in this specification, an arbitrary direction in a plane including the longitudinal direction L and the width direction W is referred to as a “planar direction”.
Furthermore, in this specification, in the thickness direction T of the sanitary napkin 1, when the sanitary napkin 1 is worn, the proximal side relative to the skin surface of the wearer is referred to as the skin side, and the sanitary napkin 1 When the is worn, the “distal side” relative to the skin surface of the wearer is referred to as the non-skin side.
The definitions of these terms are similarly used for various members constituting the sanitary napkin 1 and absorbent articles other than the sanitary napkin 1.

[Sanitary napkin]
As shown in FIG. 1, a sanitary napkin 1 (an example of an “absorbent article” in the present invention) according to an embodiment of the present invention is long in the longitudinal direction L and in the width direction W in plan view. It is a short, substantially rectangular shape, and has a vertically long shape in which both end edges in the longitudinal direction L project so as to draw an arc toward the outer side in the longitudinal direction L.
Furthermore, the sanitary napkin 1 protrudes so that both end portions in the width direction W of the sanitary napkin 1 form a substantially trapezoidal shape toward the outer side in the width direction W at the center portion in the longitudinal direction L. It has a pair of wing parts 9 and 9.

  In addition, the planar view shape of the sanitary napkin 1 is not limited to the thing of such an aspect, If the length of the longitudinal direction L is a longitudinally longer shape than the length of the width direction W, it will be in various usage aspects etc. Any desired shape (eg, rectangle, ellipse, hourglass, etc.) can be employed. Moreover, the shape of the wing part 9 is not limited to the substantially trapezoidal shape, and may be, for example, a semicircular shape or a semielliptical shape.

As shown in FIG. 2, the sanitary napkin 1 of the present embodiment has a surface sheet 2 that forms a skin-side surface of the sanitary napkin 1 in the thickness direction T, and a non-skin-side surface of the sanitary napkin 1. Are formed as a basic structure. The back surface sheet 3 is formed between the two sheets and the absorbent body 4 is disposed between the two sheets.
In the present embodiment, the sanitary napkin 1 includes an auxiliary sheet 5 disposed between the top sheet 2 and the absorber 4 in the thickness direction T, as shown in FIGS. A pair of side sheets 6 and 6 disposed at both ends of the napkin 1 in the width direction W are further provided.
In the present embodiment, each of the pair of side sheets 6 and 6 includes a pair of non-skins of a pair of loop portions 5L and 5L in which both end portions in the width direction W of the auxiliary sheet 5 are folded back to the non-skin side. The side surface is joined so that the skin side surface of the end portion on the inner side in the width direction W of each side sheet 6 overlaps, while the non-skin on the outer side in the width direction W of each side sheet 6 The side surface is joined to the skin side surface of the back sheet 3.

Hereinafter, various members constituting the sanitary napkin 1 of the present embodiment will be described in more detail.
Here, FIG. 3 is a schematic diagram in which the main part of the first fiber layer 2a in the top sheet 2 is enlarged, FIG. 4 (a) is an enlarged plan view of the top sheet 2, and FIG. FIG. 5 is a cross-sectional view taken along the line IVb-IVb of the top sheet 2 of FIG.

[Surface sheet]
As shown in FIG. 1, the top sheet 2 has a substantially rectangular shape extending in the longitudinal direction L from the longitudinal end portion on the front side to the longitudinal end portion on the rear side of the sanitary napkin 1 in plan view. It has a vertically long plan view shape. As shown in FIG. 2, the top sheet 2 is arranged at a skin side position in the thickness direction T of the sanitary napkin 1 and can contact the wearer's skin (that is, the skin of the sanitary napkin 1 Side surface) and a liquid-permeable sheet-like member.
In the present specification, in the longitudinal direction L of the sanitary napkin 1, one side that is relatively proximal to the wearer's abdomen when wearing the sanitary napkin 1 is referred to as the front side, The other side that is relatively distal to the abdomen is referred to as the rear side. In this connection, the sanitary napkin 1, as shown in FIG. 1, in the longitudinal direction L, having a front area A _F, the central region A _C and the rear side area A _B.

Then, in this embodiment, the topsheet 2 has a first fibrous layer 2a to form a skin-side surface of the water retention fibers F includes ₁ and topsheet 2, a thermoplastic resin fiber F ₂ and water retention fibers F ₁ And a second fiber layer 2b that forms a non-skin side surface of the top sheet 2 adjacent to the non-skin side of the first fiber layer 2a, and a sheet-like member having a two-layer structure. Yes.
In addition, the surface sheet 2 may further include one or a plurality of fiber layers on the non-skin side of the second fiber layer 2b, and may have a multilayer structure of three layers or more as a whole.

(First fiber layer)
The first fibrous layer 2a as described above includes water retention fibers F _1.
The water retaining fiber F ₁ is not particularly limited as long as it has a property of absorbing and retaining moisture (water retaining property), and examples thereof include cellulosic fibers.
Furthermore, as a cellulose fiber, if it is a fiber containing a cellulose, it will not restrict | limit, For example, a natural cellulose fiber, a regenerated cellulose fiber, a refined cellulose fiber, a semi-synthetic cellulose fiber etc. are mentioned. Examples of natural cellulose fibers include plant fibers, for example, seed hair fibers such as cotton, stark fibers such as hemp, leaf vein fibers such as Manila hemp, and fruit fibers such as coconut.

Examples of cotton (fiber) include hirssum cotton such as Upland cotton, barbadense cotton, arborium cotton, and Herbaqueum cotton. In addition, as cotton (fiber), organic cotton, pre-organic cotton (trademark), etc. can also be used. However, the organic cotton means cotton that has been certified by GOTS (Global Organic Textile Standard).
Examples of the regenerated cellulose fiber include fibers such as rayon, for example, viscose rayon obtained from viscose, polynosic, modal, copper ammonia rayon obtained from a copper ammonia salt solution of cellulose (also referred to as “cupra”). .
As refined cellulose fibers, lyocell, specifically, pulp is dissolved in an aqueous solution of N-methylmorpholine N-oxide to form a spinning dope and extruded into a dilute solution of N-methylmorpholine N-oxide. And so on. Purified cellulose is commercially available, for example, as Tencel (trademark).
Examples of semisynthetic cellulose fibers include acetate fibers such as triacetate and diacetate.

Among the various water retaining fibers described above, the water retaining fiber F ₁ is preferably a natural cellulose fiber, more preferably a cotton, and still more preferably an organic cotton, from the viewpoint of water retention and touch.
When the water-retaining fiber F ₁ is an organic cotton excellent in flexibility and texture, the topsheet 2 can easily ensure good flexibility and texture, and can realize a better touch. Moreover, when the surface sheet 2 contains such organic cotton, it is possible to nurture a sense of security for the wearer of the sanitary napkin 1 by using a natural material for the surface sheet 2. There are also advantages.

(Second fiber layer)
The second fibrous layer 2b as described above, and a thermoplastic resin fiber F ₂ and water retention fibers F _1.
Thermoplastic resin fiber F _2, if fiber made of a thermoplastic resin (generally hydrophobic fibers) is not particularly limited. Examples of the thermoplastic resin forming the thermoplastic resin fiber F ₂ include olefin resins such as polyethylene (PE), polypropylene (PP), and ethylene-vinyl acetate copolymer (EVA), polyethylene terephthalate (PET), poly Known resins such as polyester resins such as lactic acid (PLA) and polyamide resins such as 6-nylon may be used, and these resins may be used alone or in combination of two or more resins.

Further, the structure of the thermoplastic resin fiber F ₂ is not particularly limited. For example, a core-sheath type composite fiber such as PET (core part) / PE (sheath part) or PP (core part) / PE (sheath part), Composite fibers such as side-by-side type composite fibers and sea-island type composite fibers; hollow type fibers; irregular cross-section type fibers such as flat, Y-shaped, and C-shaped; three-dimensional crimped fibers with latent crimp or actual crimp; Examples include split fibers that are split by a physical load such as water flow, heat, embossing, and the like, and fibers having these structures may be used alone or in combination of two or more types.
In the sanitary napkin 1 of the present embodiment, the thermoplastic resin fibers F ₂ of the second fibrous layer 2b is a core-sheath type composite fibers of PP (core) / PE (sheath).

As for the water-retentive fiber F ₁ included in the second fibrous layer 2b, it is the same as the water retention fibers F ₁ of the first fibrous layer 2a.

Then, in the first fibrous layer 2a and the second fibrous layer 2b constituting the topsheet 2, the percentage of water retention fibers F ₁ of the fibers constituting the first fiber layer 2a is, constituting the second fiber layer 2b which is greater than the proportion of the water-retentive fiber F ₁ of the fibers. Thereby, also the surface sheet 2 is comprise a thermoplastic resin fibers F _2, the thermoplastic resin fibers F ₂ is less likely to contact the wearer's skin, unpleasant, such as feel was feel and tingling which was stiff Stimulation can be made difficult to give to the wearer.

The ratio of water-retentive fiber F ₁ of the fibers constituting the first fiber layer 2a, from the viewpoint of enhancing the feel of the surface sheet 2, thermoplastic resin fibers F of all the constituent fibers (described later of the first fibrous layer 2a based on the total weight of.) except the _second melt is preferably 70 to 100 mass%, more preferably from 80 wt% to 100 wt%, more preferably 90 to 100 mass%. By setting the ratio of the water retention fiber F ₁ to 70% by mass or more, the wearer recognizes the skin-side surface of the surface sheet 2 formed by the first fiber layer 2a as containing the water retention fiber F _1. It becomes easy to feel good touch feeling.

Of the fibers which make up the first fiber layer 2a, fibers other than water retention fibers F ₁ is not particularly limited as long as the fibers capable of forming a layer having a liquid-permeable, for example, a second fibrous layer 2b it may contain the same thermoplastic resin fibers and thermoplastic resin fibers F ₂ contained.
In the present embodiment, the first fiber layer 2a has a water-retaining fiber F ₁ ratio of 100% by mass, and does not include fibers other than the water-retaining fiber F ₁ .

In the present embodiment, the average fiber length of the water-retentive fiber F ₁ of the second fiber layer 2b is shorter than the average fiber length of the water-retentive fiber F ₁ of the first fibrous layer 2a. Accordingly, at least the fibers constituting the second fiber layer 2b are likely to be close to each other (that is, the distance between the fibers is easily shortened), and the capillary phenomenon is more likely to occur, so liquid excrement such as menstrual blood and urine can be removed. It can be drawn more strongly into the second fiber layer 2b.

3, at least some of the water-retentive fiber F ₁ are included in the first fibrous layer 2a, at least some of the confounding portion P _E of the entangled portion P _E between fibers, thermoplastic resin fibers It is covered with the melt _{F 2M} of F _2.
Thus, the sanitary napkin 1 of this embodiment, the ratio of the water-retentive fiber F ₁ of the first fibrous layer 2a on the surface sheet 2 becomes larger than the ratio of the water-retentive fiber F ₁ of the second fiber layer 2b in it is over, at least part of the thermoplastic resin fibers F ₂ is included in the second fibrous layer 2b, at least part of the confounding portion P _E of the entangled portion P _E of the fibers contained in the first fibrous layer 2a , since a melt F _2M coating the water-retentive fiber F _1, also the topsheet 2 is comprise a thermoplastic resin fibers F _2, contact the thermoplastic resin fibers F ₂ is the skin of the wearer It is difficult to give the wearer an unpleasant stimulus such as an irritating feel or a tingling feel.
Furthermore, in the sanitary napkin 1 of the present embodiment, at least a part of the water retention fibers F ₁ included in the first fiber layer 2a is heated in at least a part of the entangled part P _E among the entangled parts P _E between the fibers. By being covered with the melt F _2M of the plastic resin fiber F ₂ , the entanglement between the fibers in the surface sheet 2 is difficult to be loosened, and the water retention fiber F ₁ is difficult to break. unraveling and water retention fibers F water-retentive fiber F ₁ caused by the rupture of _one fuzz can be unlikely to occur, can be difficult to give an unpleasant stimulus by the fuzz wearer.
Therefore, the sanitary napkin 1 according to the present embodiment includes the top sheet 2 that is difficult to give unpleasant stimulation to the wearer's skin and is excellent in touch.

In the present specification, the entangled portion refers to a portion where the fibers are entangled, and includes the entangled point and the periphery of the entangled point.
Moreover, in this specification, a molten material means the thing of the state solidified through the molten state.

Further, as described above, in the present embodiment, as the thermoplastic resin fibers F ₂ in the second fibrous layer 2b of the topsheet 2, the core-sheath type composite fibers are used. Thus, the surface sheet 2, while the sheath made of a low resin component having a melting point of core-sheath type composite fiber to coat the water-retentive fiber F ₁ by melting, core water retention fibers F made of high melting point resin ₁ and other core-sheath type composite fibers (thermoplastic resin fibers F ₂ ) can be maintained in an entangled state, and a predetermined bulk can be maintained as a surface sheet.
In addition, when using a composite fiber in which a resin component having a low melting point such as a side-by-side type composite fiber is exposed on the surface of the composite fiber, such as a side-by-side type composite fiber, the same effects as described above are obtained. Can play.

Further, in the present embodiment, the thermoplastic resin fiber F ₂ described above has one thermoplastic resin fiber F ₂ entangled with a plurality of water retention fibers F ₁ , and the one thermoplastic resin. each of confounding portions P _E between the water retention fibers F ₁ of the resin fibers F ₂ and a plurality of are covered by the melt F _2M thermoplastic resin fibers F ₂ of the one.
Thus, each of the entangled portion P _E between one thermoplastic resin fibers F ₂ and a plurality of water-retentive fiber F ₁ is covered by one of the thermoplastic resin fibers F ₂ melts F _2M In this case, since a plurality of water retaining fibers F ₁ are connected via one thermoplastic resin fiber F ₂ , the above-mentioned loosening due to entanglement and breakage of the water retaining fibers F ₁ are less likely to occur. can do.

  Moreover, in this invention, it is preferable that the melt of a thermoplastic resin fiber is not exposed to the skin side surface of a 1st fiber layer. If the melt of the thermoplastic resin fiber is not exposed on the surface of the first fiber layer on the skin side, the presence of the melt is less likely to be sensed by the wearer, and a good touch of the surface sheet can be obtained more reliably. Can do.

The fiber length (average fiber length) of the water retention fiber F ₁ of the first fiber layer 2a is not particularly limited as long as the effect of the present invention is not impaired, but at least the average of the water retention fibers F ₁ contained in the first fiber layer 2a. fiber length, shorter is more preferable than the average fiber length of the thermoplastic resin fibers F _2. If the average fiber length of the water-retentive fiber F ₁ included in the first fibrous layer 2a is shorter than the average fiber length of the thermoplastic resin fibers F ₂ in the second fibrous layer 2b, 1 included in the second fibrous layer 2b because the number of water-retentive fiber F ₁ of the first fibrous layer 2a in contact with the thermoplastic resin fibers F ₂ of the increases, adhesion of the melt F _2M thermoplastic resin fibers F ₂ per one said water-retentive fiber As a result, it is possible to make the above-mentioned water-retaining fibers F ₁ less likely to fluff.

Incidentally, as a specific average fiber length of the water-retentive fiber _{F 1} that is included in the first fibrous layer 2a, for example, an average fiber length of 5Mm～80mm (i.e. 5mm or 80mm or less). When the average fiber length of the water-retaining fiber F ₁ is 5 mm or more, the flexibility and texture of the water-retaining fiber F ₁ are easily maintained and the fibers are easily entangled, so that sufficient strength can be easily obtained. On the other hand, when the average fiber length of the water-retaining fibers F ₁ is 80 mm or less, some water-retaining fibers F ₁ are difficult to extend outward in the width direction W of the sanitary napkin 1. It is possible to make it difficult for liquid excrement to leak from the width direction W of the sanitary napkin 1 through the water-retaining fibers F ₁ extending outward.
Further, the average fiber length of water-retentive fiber _{F 1} included in the first fibrous layer 2a is preferably at 5mm or more 60mm or less, and more preferably less than than 5mm 35 mm. When the average fiber length of the water-retaining fibers F ₁ contained in the first fiber layer 2a is 5 mm or more and less than 35 mm, the water-retaining fibers F ₁ are less likely to be fuzzed, and the water-retaining fibers F ₁ are flexible. It is easy to maintain the texture and the texture, and as a result, the touch of the topsheet 2 can be made more excellent.

The fineness, average fiber length, and the like of the fibers other than the water retention fiber F ₁ in the first fiber layer 2a are not particularly limited, but the water retention fiber F is considered in consideration of the influence of the water retention fiber F _{1 on} the touch. It is preferably about the same as ₁ (within a range of 0.5 to 2 times). However, in the present embodiment, the first fibrous layer 2a as described above does not include the water-retentive fiber F ₁ except the fiber.

The proportion of water-retentive fiber F ₁ of the fiber constituting the second fiber layer 2b is the less than the percentage of water retention fibers F ₁ of the first fibrous layer 2a, not particularly limited. The proportion of the water-retentive fiber F ₁ of the second fiber layer 2b, for example, with respect to the total mass of all fibers constituting the second fiber layer 2b, include 50 wt% to 90 wt%. When the ratio of the water retention fiber F ₁ is 50% by mass or more, the touch feeling in a state where pressure is applied in the thickness direction T can be improved, and the ratio of the water retention fiber F ₁ is 90% by mass. % Or less, the effect of preventing fuzz due to the melt F _2M of the thermoplastic resin fiber F ₂ is more stably exhibited.
Furthermore, the proportion of water-retentive fiber _{F 1} of the second fibrous layer 2b is preferably 60 wt% to 85 wt%, more preferably 70 wt% to 80 wt%. Correspondingly, the proportion of thermoplastic resin fiber F ₂ of the second fiber layer 2b is, for example, 10% to 50% by weight relative to the total mass of all fibers constituting the second fiber layer 2b and the like, 15 % By mass to 40% by mass is preferable, and 20% by mass to 30% by mass is more preferable.
Note that the second fibrous layer 2b, in addition to the water-retentive fiber F ₁ and the thermoplastic resin fibers F _2, may include a third fiber.

Incidentally, the fineness of the water-retentive fiber F ₁ included in the second fibrous layer 2b is preferably the same as the water retention fibers F ₁ included in the first fibrous layer 2a.

Fiber length of the water-retentive fiber F ₁ of the second fiber layer 2b (average fiber length) is not particularly limited as long as it does not inhibit the effects of the present invention, similarly to the first fibrous layer 2a described above, the thermoplastic resin fibers F It is preferable that the average fiber length is less than ₂ . Since the average fiber length of the water-retentive fiber F ₁ is shorter than the average fiber length of the thermoplastic resin fibers F _2, becomes large number of water-retentive fiber F ₁ in contact with the thermoplastic resin fibers F ₂ of one, the water retention It is possible to increase the adhesion amount of the melt F _2M of the thermoplastic resin fiber F ₂ per one of the functional fibers, and to make the above-mentioned interlaced fibers loose and breakage of the water retention fiber F ₁ more difficult. it can.

As a specific average fiber length of the water-retentive fiber _{F 1} included in the second fibrous layer 2b, for example, the average fiber length of 3Mm～40mm. If the average fiber length of the water-retentive fiber F ₁ is at 3mm or more, on easy to maintain the flexibility and texture of the water-retentive fiber F _1, for the fibers are easily entangled, sufficient strength can be easily obtained. On the other hand, when the average fiber length of the water retaining fiber F ₁ is 40 mm or less, the degree of dynamic freedom of the fibers in the web state is high during the production of the second fiber layer 2b, and the water retaining fiber F ₁ is the thermoplastic resin fiber F. _Since it becomes easy to enter the gap between the _two , the interfiber distance in the second fiber layer 2b tends to be short, and as a result, the fiber density of the second fiber layer 2b tends to be high.
Further it, the average fiber length of the water-retentive fiber F ₁ included in the second fibrous layer 2b, like the water-retentive fiber F ₁ of the first fibrous layer 2a described above, although not particularly limited, it is less than 5 mm 35 mm Is preferred. When the average fiber length of the water retaining fiber F ₁ contained in the second fiber layer 2b is within such a range, it is easy to maintain the flexibility and texture of the water retaining fiber F ₁ . The touch can be made better.

In the present invention, a mixed water retaining fiber obtained by mixing two or more types of water retaining fibers having different average fiber lengths can be used as the water retaining fiber F ₁ included in at least the second fiber layer 2b. For example, the water-retaining fibers are water-retaining fibers having a long average fiber length, water-retaining fibers having an average fiber length of 15 mm to 40 mm (preferably 20 mm to 35 mm), and water-retaining fibers having a short average fiber length. A water-retaining fiber having a length of 3 mm to 25 mm (preferably 5 mm to 20 mm) can be mixed and used. When such a mixed water retention fiber is used as the water retention fiber F ₁ of the second fiber layer 2b, the average fiber length of the second fiber layer 2b is enhanced by the water retention fiber having a long average fiber length while the average fiber length is increased. The distance between fibers of the 2nd fiber layer 2b can be shortened with a short water retention fiber.

In addition, when the 2nd fiber layer 2b contains the 1 or several fiber layer in the non-skin side, ie, when the surface sheet 2 has the multilayer structure of three layers or more as a whole, liquid permeation | transmission from the viewpoint of enhancing the gender, the more fiber layers close to the non-skin side of the surface of the surface sheet 2, water retention fibers ratio of F ₁ is relatively low, and have an average fiber length of the water-retentive fiber F ₁ is short preferable.

Entanglement of ease of the water-retentive fiber F ₁ is a major component fibers of the thermoplastic resin fibers F ₂ and the first fiber layer 2a of the second fibrous layer 2b, i.e., the liquid waste from the first fibrous layer 2a migrated and ease of, from the viewpoint of preventing the delamination between the first fibrous layer 2a and the second fibrous layer 2b, the fineness of the thermoplastic resin fibers F ₂ of the second fibrous layer 2b, the first fibrous layer 2a it is preferable smaller than the fineness of the water-retentive fiber F _1.

The fiber length of the thermoplastic resin fibers F ₂ of the second fiber layer 2b (average fiber length), as long as it does not inhibit the effect of the present invention is not particularly limited, for example, 10Mm～80mm. However, entanglement of ease of the water-retentive fiber F ₁ is the major constituent fiber of the thermoplastic resin fibers F ₂ of the second fiber layer 2b first fibrous layer 2a, i.e., a liquid excretion from the first fibrous layer 2a and and ease of migration of the object, from the viewpoint of preventing the delamination between the first fibrous layer 2a and the second fibrous layer 2b, an average fiber length of the thermoplastic resin fibers F ₂ of the second fibrous layer 2b is a long is preferably compared with average fiber length of the water-retentive fiber _{F 1} of the first fiber layer 2a and the second fibrous layer 2b, for example, the average fiber length of 15Mm～100mm.

Each thickness of the 1st fiber layer 2a and the 2nd fiber layer 2b is not restrict | limited especially unless the effect of this invention is inhibited, For example, the thickness of 0.05 mm-4 mm is mentioned, 0.1 mm-3 mm The thickness is preferably 0.2 mm to 2 mm.
However, when the thickness of the first fiber layer 2a is relatively thick and the thickness of the second fiber layer 2b is relatively thin, the touch of the first fiber layer 2a is improved and rewetting on the wearer's skin. When the back becomes easy to suppress and the thickness of the first fiber layer 2a is relatively thin and the thickness of the second fiber layer 2b is relatively thick, the water retention fiber F ₁ of the first fiber layer 2a. but it becomes more likely to be covered by the melt F _2M thermoplastic resin fibers F ₂ of the second fibrous layer 2b, it is possible to more reliably suppress fuzz by water retention fibers F ₁ described above.
Moreover, the thickness (namely, total thickness of each fiber layer) of the surface sheet 2 is not particularly limited as long as the effect of the present invention is not impaired, and for example, a thickness of 0.1 mm to 5 mm is mentioned. A thickness of 4 mm to 4 mm is preferable, and a thickness of 0.8 mm to 3 mm is more preferable.

Here, the ratio of the kind of fiber in a sheet | seat like a fiber layer can be measured as follows.
That is, according to the following procedure, the ratio of the kind of fiber can be measured by coloring the water retaining fiber and the thermoplastic resin fiber with different colors.
(1) The top sheet 2 is cut into a size of 70 mm × 70 mm to obtain a sample.
(2) By carrying out a coloring treatment with the reagent Kaystein Q (Color dye Co., Ltd.), only the water-retaining fibers are dyed blue and only the thermoplastic resin fibers are colored yellow.
(3) Using a digital microscope VHX-100 manufactured by Keyence Corporation, measure the ratio of blue to yellow when viewed from the skin side surface (first fiber layer 2a) of the sample in a range of 50 mm x 50 mm. Therefore, it is set as the ratio of the kind of fiber in the 1st fiber layer 2a. On the other hand, the ratio of the kind of fiber in the 2nd fiber layer 2b is made by measuring the ratio of blue and yellow when it sees from the surface (2nd fiber layer 2b) of a non-skin side in the range of 50 mm x 50 mm.
In determining the size relationship between the ratios of the types of fibers, if the size relationship between the blue and yellow ratios is apparent, it can be determined by the appearance, but the ratio between the blue and yellow ratios can be determined. If the relationship cannot be judged by appearance alone, count the number of fibers colored in each color, and use the number and the structural characteristics of each fiber (for example, fiber size such as fiber length and fineness, specific gravity, etc.) It can be judged by calculating the total mass of each fiber and comparing the total mass.

The distance between constituent fibers in a sheet such as a fiber layer can be measured according to the following measurement method.
(1) The top sheet 2 is cut into a size of 10 mm × 10 mm to obtain a sample.
(2) Using a digital microscope VHX-100 (lens VH-Z20R + variable illumination attachment VH-K20) manufactured by Keyence Co., Ltd., an imaging magnification: 200 times, a measurement area: 1300 μm in length × 1735 μm in width, a surface sheet Images of the skin surface 2 (first fiber layer 2a) and the non-skin side surface (second fiber layer 2b) are taken. At that time, for each of the skin-side surface and the non-skin-side surface, images are taken a total of five times for each depth of 20 μm in a depth range of 0 μm to 100 μm.
(3) The area of the part where no fiber is present is determined from each of the obtained images. At that time, the presence or absence of a fiber in the pixel is determined based on whether the luminance at each pixel in the obtained image is lower or higher than a predetermined luminance (threshold), and the fibers in the imaging region in each image are determined. Determine presence or absence. However, since light is transmitted through only a portion where no fiber is present and brightens (that is, luminance is increased), the area of the portion where no fiber is present in the imaging region is obtained using the light.
(4) The void ratio is calculated by subtracting the calculated area of the region where there is no fiber from the area of the imaging region (measurement area) and dividing by the area of the imaging region (measurement area). Such a calculation is performed on images with a depth of 20 μm, and five void ratios are calculated.
(5) The average value of the calculated five void ratios is defined as the respective void ratios of the skin-side surface (first fiber layer 2a) and the non-skin-side surface (second fiber layer 2b) of the topsheet 2. . The size of the interfiber distance can be determined by comparing the size of the porosity. That is, when the porosity is large, the interfiber distance is large. For example, on the skin side surface of the top sheet 2 (first fiber layer 2a: surface of, for example, 100% cotton fiber (water retaining fiber)), the porosity is 25.4%, and the non-skin side surface (second surface) In the fiber layer 2b: for example, the surface of 60% cotton fiber (water retaining fiber) and 40% thermoplastic resin fiber), the porosity is 24.5%.

  Further, the fiber length (average fiber length) of the fiber of the sheet such as the fiber layer is determined by “A7.1.1 A method (standard)” of “A7.1 Measurement of fiber length” in Annex A of JIS L 1015: 2010. Method) According to “Method of 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.

  Moreover, the basic weight of a sheet | seat like a fiber layer can be measured in accordance with the following measuring methods. That is, a fiber layer for one layer is prepared, the fiber layer is cut into a size of 5 cm × 5 cm, used as a sample, dried in an atmosphere of 100 ° C. or higher, and then the mass of the sample is measured. Next, the basis weight of the sample is calculated by dividing the measured mass by the area of the sample. A value obtained by averaging the basis weights of 10 samples is defined as the basis weight of the sheet.

  Moreover, the thickness of a sheet | seat like a fiber layer can be measured in accordance with the following measuring methods. That is, an enlarged image is taken from a direction perpendicular to the cut surface of the top sheet 2 using a digital microscope VHX-100 manufactured by Keyence Corporation. At this time, the enlarged image is an image that has been enlarged to a magnification such that the entire surface sheet 2 in the thickness direction T can be photographed, and the enlarged magnification is, for example, 20 to 50 times. The obtained enlarged image (three-dimensional image) is converted into a two-dimensional image, and the thickness of each fiber layer is measured in the two-dimensional image. The average value of the thicknesses measured at three different cut surfaces is taken as the thickness of the topsheet 2.

Moreover, in the sanitary napkin 1 of the above-mentioned embodiment, it is preferable that the average distance between the constituent fibers of the second fiber layer 2b is shorter than the average distance between the constituent fibers of the first fiber layer 2a. When the average distance between the constituent fibers of the second fiber layer 2b is shorter than the average distance between the constituent fibers of the first fiber layer 2a, the fibers constituting the second fiber layer 2b are close to each other, and the second Since the capillary phenomenon can be generated more strongly in the fiber layer 2b, the liquid excretion excreted on the skin side surface of the first fiber layer 2a can be quickly drawn into the second fiber layer 2b. the retracted liquid excreta in second fibrous layer 2b, it is possible to rapidly transition from a thermoplastic resin fiber F ₂ to the non-skin side of the second fibrous layer 2b.
Accordingly, the sanitary napkin 1 having such a configuration can ensure good absorption performance while making the topsheet 2 excellent in touch.

Furthermore, in the sanitary napkin 1 of this embodiment, it is preferable that the fiber density of the 2nd fiber layer 2b is larger than the fiber density of the 1st fiber layer 2a. That is, it is preferable that a gradient of the fiber density exists in the thickness direction T of the topsheet 2 so that the fiber density increases from the first fiber layer 2a toward the second fiber layer 2b.
In this way, when the fiber density of the second fiber layer 2b is larger than the fiber density of the first fiber layer 2a, the fibers constituting the second fiber layer 2b are close to each other, and the second fiber layer 2b Since the capillary phenomenon can be generated more strongly, the liquid excretion supplied to the skin side surface of the top sheet 2 (that is, the skin side surface of the first fiber layer 2a) is quickly drawn into the second fiber layer 2b. it can, further, the drawn liquid excreta in the second fibrous layer 2b, it is possible to rapidly transition from a thermoplastic resin fiber F ₂ to the non-skin side of the second fibrous layer 2b.
Accordingly, the sanitary napkin 1 having such a configuration can ensure good absorption performance while making the topsheet 2 excellent in touch.

  However, in the case where one or more fiber layers are further provided on the non-skin side surface of the second fiber layer 2b, that is, when the surface sheet 2 has a multilayer structure of three layers or more, the surface sheet It is preferable that the fiber layer closer to the non-skin-side surface of 2 has a relatively high fiber density. Thereby, the liquid permeability from the fiber layer positioned relatively on the skin side to the fiber layer positioned relatively on the non-skin side can be further increased, and the liquid excrement can be stabilized by the auxiliary sheet 5 and the absorbent body 4. Can be migrated.

The fiber density of a sheet such as a fiber layer can be measured according to the following measurement method.
(1) The top sheet 2 is cut into a size of 10 mm × 10 mm to obtain a sample.
(2) The cut surface parallel to the thickness direction T of the sample is enlarged and observed using a scanning electron microscope (JEOL Ltd .: JCM-5100). The magnification is a magnification (for example, 150 to 500 times) at which a cross section of 30 to 60 fibers can be measured within one screen.
(3) The observation region is divided into three equal parts in the thickness direction T into the skin side layer, the intermediate layer, and the non-skin side layer, the skin side layer is defined as the first fiber layer 2a, and the non-skin side layer is defined as the first layer. After setting it as the 2 fiber layer 2b, the number of the cross sections of the fiber in each fiber layer is measured. That is, the number of cross-sections of the cut fibers is counted on a cut surface having a predetermined area.
(4) the number of cross section of the fiber in terms of the number of the cross-section of the fibers per 1 mm ^2, which the fiber density (the / 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.
In addition, as the fiber density, the number of fibers per unit volume may be used. The number of fibers per unit volume can be determined, for example, by analysis using X-ray CT. Although the fiber density per unit area and the fiber density per unit volume are different, the relative results of fiber densities between fiber layers (for example, large and small) have the same result.

Further, as shown in FIG. 3, in this embodiment, a portion of thermoplastic resin fibers F ₂ in the second fibrous layer 2b are thermally fused to each other. That is, some of the thermoplastic resin fibers F ₂ are joined to each other by thermal fusion at the places where the thermoplastic resin fibers are in contact with each other, and in the second fiber layer 2b, a kind of the thermoplastic resin fibers F ₂ are formed. It can be seen that it forms a matrix.
Sanitary napkin 1 having such a configuration, the second fiber layer 2b, the portion of the thermoplastic resin fibers F ₂ was heat-sealed to each other, keeping a shape of the second fibrous layer 2b stably Therefore, even if the average fiber length of the water retention fibers F ₁ contained in the second fiber layer 2b is relatively short, the water retention fibers F ₁ are not biased between the thermoplastic resin fibers F ₂ (in the matrix). It can be held stably. Thereby, the sanitary napkin 1 of this embodiment can transfer the liquid excretion drawn in the 2nd fiber layer 2b to the absorber 4 (and auxiliary sheet 5) stably without bias, and was excellent. Absorption performance can be demonstrated.
Incidentally, the thermoplastic resin fibers F ₂ of the sanitary napkin 1 is thus not have to be heat-sealed to each other.

Further, as shown in FIG. 4, in this embodiment, at least a portion of the thermoplastic resin fibers F ₂ of the second fibrous layer 2b are exposed to the skin-side surface of the first fibrous layer 2a. That is, the thermoplastic resin fibers F ₂ of the second fibrous layer 2b, the second while the shape of the fiber layer 2b held stably, the at least partially continuously from the second fibrous layer 2b first fibrous layer 2a And further reaches the surface of the first fiber layer 2a on the skin side.
The sanitary napkin 1 having such a configuration, by thermoplastic resin fibers F ₂ of the second fibrous layer 2b extends continuously to the inside of the first fibrous layer 2a, of the first fibrous layer 2a since the water-retentive fiber F ₁ can be stably held between the thermoplastic resin fibers F _2, the average distance between the fibers constituting the first fiber layer 2a is relatively long, strength of the first fibrous layer 2a is Even if it is relatively weak, it is possible to suppress sagging. Further, water retention fibers F ₁ of the first fibrous layer 2a is held between the thermoplastic resin fibers F _2, further by being covered by the melt F _2M of the thermoplastic resin fibers F _2, water retention fibers it is possible to effectively suppress the generation of fuzz by breakage of F _1.
Therefore, the sanitary napkin 1 having such a configuration can make the first fiber layer 2a of the top sheet 2 more excellent in touch.
Furthermore, a part of the thermoplastic resin fiber F ₂ that does not have the water retention property of the second fiber layer 2 b is present in the first fiber layer 2 a, so that the first fiber layer is interposed via the thermoplastic resin fiber F _2. Since the transfer of the liquid excrement from 2a to the second fiber layer 2b can be promoted, the liquid excrement can be stably transferred to the absorber 4 (and the auxiliary sheet 5).
Incidentally, the thermoplastic resin fibers F ₂ of the second fibrous layer 2b of the sanitary napkin 1 may not be exposed to the skin-side surface of the first fibrous layer 2a.

Moreover, in this embodiment, the fiber which comprises the surface sheet 2 is a fiber which exists in the both ends of the width direction W of the surface sheet 2, rather than the fiber which exists in the center part of the width direction W of the surface sheet 2. The top sheet 2 is oriented in the longitudinal direction L. That is, in the topsheet 2 of the present embodiment, the fibers present in the center portion in the width direction W have a relatively small orientation in the longitudinal direction L, and the fibers present at both ends in the width direction W are in the longitudinal direction L. The orientation of is relatively large.
In the sanitary napkin 1 having such a configuration, since the fiber orientation is relatively random in the center portion in the width direction W of the top sheet 2, the liquid excrement can be diffused substantially concentrically. Since the fiber orientation is formed in the longitudinal direction L at both ends in the width direction W of the topsheet 2, the liquid excrement reaching the both ends can be diffused in the longitudinal direction L. That is, the sanitary napkin 1 can be used as a whole in the planar direction, and more excellent absorption performance can be exhibited. Moreover, since the number of fibers exposed from the edge decreases at both ends of the top sheet 2 in the width direction W, friction on the wearer's skin is reduced, and the touch can be made smoother.
In addition, as for the fiber orientation of the surface sheet 2 of the sanitary napkin 1, the orientation of the longitudinal direction L does not need to be relatively large in the both ends of the width direction W.

As shown in FIG. 1, the sanitary napkin 1 has an excretory opening contact area XA at a position slightly in front of the center in the longitudinal direction L and in the center in the width direction W in plan view. Is set. The excretion opening contact area XA is an area that faces or contacts the wearer's excretion opening when the sanitary napkin 1 is worn, and is generally set according to the type and use of the absorbent article. The excretory opening contact area XA is, for example, at a position slightly in front of the central portion of the absorbent body 4 in the longitudinal direction L and having a length of about 1/4 to 1/2 of the entire length of the absorbent body 4 in the longitudinal direction L. In the width direction W, the width is set to approximately 1/2 to 1/3 of the entire length of the absorbent body 4 in the width direction W at a substantially central position of the absorbent body 4.
In addition, like the sanitary napkin 1 described above, when the absorbent article includes a wing part, the excretory opening contact area is generally set so as to overlap the wing part in the width direction. For example, the excretory opening contact area can be set so that the longitudinal center position of the excretion opening contact area substantially overlaps the longitudinal center position of the wing part in the width direction.

(Pressing part)
In the present embodiment, the sanitary napkin 1 is located on both outer sides in the width direction W with respect to the excretory opening contact area XA and continuously or intermittently in the longitudinal direction L as shown in FIG. A pair of extended pressing parts (squeezing grooves) 12 and 12 are provided.
Moreover, as shown in FIG. 1, in this embodiment, the sanitary napkin 1 is located in the rear side of the longitudinal direction L of each of a pair of pressing parts 12 and 12, and is a pair of pressing which extends in the longitudinal direction L Squeezing portions (squeezing grooves) 13 and 13, and squeezing portions (squeezing grooves) 11 and 14 that are located on the front side and the rear side in the longitudinal direction L with respect to the excretory opening contact area XA and have a heart-shaped annular shape And a plurality of dot-shaped pressing parts 15 in the excretion opening contact area XA.

These pressing parts 11 to 15 are formed by pressing the top sheet 2 and the absorbent body 4 in the thickness direction T by processing means such as embossing. That is, the top sheet 2, the auxiliary sheet 5, and the absorbent body 4 (specifically, the core wrap 4 b and the absorbent core 4 a on the skin side of the absorbent body 4) are squeezed in the thickness direction T. As shown in FIG. 2, each pressing part is weakly pressed, formed at a position where the depth from the skin side surface of the topsheet 2 is shallow, and a low density part LPA having a relatively low fiber density, and strongly It is compressed and has a high-density portion HPA that is formed at a position where the depth from the skin-side surface of the topsheet 2 is deep and the fiber density is relatively high. These low density part LPA and high density part HPA can also be called the bottom part of the depth position in each pressing part, and the bottom part of the deep position.
As shown in FIG. 2, the low density part LPA and the high density part HPA of the pressing parts 11 to 15 are located in the absorbent core 4a, but the high density part HP reaches the core wrap 4b on the non-skin side. It may be.

  In addition, the shape in particular of the pressing parts 11-15 is not restrict | limited, Arbitrary shapes according to desired liquid diffusibility, deformation | transformation inducibility, intensity | strength, etc. are employable.

Moreover, although the sanitary napkin 1 does not need to be provided with such pressing parts 11-15, it is preferable to provide at least one pressing part among the pressing parts 11-15.
When the sanitary napkin 1 (more specifically, the topsheet 2) has a squeezed portion that is recessed in the thickness direction T from the skin-side surface, the squeezed portion is a water-retaining fiber in the topsheet 2. By holding F ₁ , the above-described water retention fiber F ₁ can be made more difficult to fuzz.

Further, in the present embodiment, at least a portion of the thermoplastic resin fibers F ₂ of the second fibrous layer 2b, at least one compressing portion of compressing portions 11 to 15, exposed on the inner surface of the compressed portion Yes. When the sanitary napkin 1 is provided with such a configuration, by thermoplastic resin fibers F ₂ is present in the first fibrous layer 2a so as to be exposed on the inner surface of the compressed portion, the even within compression portions 1 water retention fibers F ₁ of the fibrous layer 2a can be stably held between the thermoplastic resin fibers F _2. This can also be less likely to occur fuzz by water retention fibers F ₁ in the compressed portion can be a touch of the first fibrous layer 2a in the compressing portion better. Furthermore, when a part of the thermoplastic resin fiber F ₂ which does not have the water retention property of the second fiber layer 2 b is present in the first fiber layer 2 a in the pressing part, the second fiber layer 2 b is pressed through the thermoplastic resin fiber F _2. Since the transfer of liquid excrement from the first fiber layer 2a in the section to the second fiber layer 2b can be promoted, the liquid excrement can be transferred more stably to the absorber 4 (and the auxiliary sheet 5). Can do.
Incidentally, the sanitary napkin 1, the thermoplastic resin fibers F ₂ may not be exposed on the inner surface of the compressed portion.

Further, in the present embodiment, at least a portion of the thermoplastic resin fibers F ₂ of the second fibrous layer 2b, at least one compressing portion of compressing portions 11 to 15, the surface of the low density portion LPA of the compressing portion Exposed. When the sanitary napkin 1 is provided with such a configuration, by thermoplastic resin fibers F ₂ is present in the first fibrous layer 2a so as to be exposed on the surface of the low-density portion LPA, the low-density portion LPA The water retention fiber F ₁ of the first fiber layer 2 a can be stably held between the thermoplastic resin fibers F ₂ . This can also be less likely to occur fuzz by water retention fibers F ₁ in the low-density portion LPA, can be better skin feel of the first fibrous layer 2a in the lower density part LPA. Furthermore, when a part of the thermoplastic resin fiber F ₂ that does not have the water retention property of the second fiber layer 2 b is present in the first fiber layer 2 a in the low density portion LPA, the thermoplastic resin fiber F ₂ is Since the transition of the liquid excrement from the first fiber layer 2a in the low density part LPA to the second fiber layer 2b can be promoted, the liquid excrement can be more stably transferred to the absorber 4 (and the auxiliary sheet 5). Can be migrated.
Incidentally, the sanitary napkin 1, the thermoplastic resin fibers F ₂ may not be exposed on the surface of the low-density portion LPA.

(Uneven structure)
In the present embodiment, the topsheet 2 has an uneven structure as shown in FIG.
As shown in FIG. 4B, the first fiber layer 2a has a first upper surface 2aE on the upper side (skin side) in the thickness direction T and a first lower surface 2aF on the lower side (non-skin side), The second fiber layer 2b has a second upper surface 2bE on the upper side in the thickness direction T and a second lower surface 2bF on the lower side. The first lower surface 2aF of the first fiber layer 2a and the second upper surface 2bE of the second fiber layer 2b are virtual boundaries between the two fiber layers. Because it penetrates into the fiber layer, it is not a strict boundary.

And the 1st fiber layer 2a is continuously extended along the longitudinal direction L, and is arrange | positioned at predetermined intervals in the width direction W, and several 1st upper surface 2aE protrudes to the upper side (skin side). A plurality of concave portions 22 in which the first upper surface 2aE is recessed downward (non-skin side), which is disposed between the convex portions 21 and the convex portions 21 that continuously extend along the longitudinal direction L and are adjacent to each other; have.
When the topsheet 2 has a specific concavo-convex structure having such a plurality of convex portions 21 and a plurality of concave portions 22, the contact area between the skin side surface of the topsheet 2 and the skin of the wearer Therefore, the possibility that an unpleasant irritation caused by the fuzz of the thermoplastic resin fibers F ₂ and the water retaining fibers F ₁ contained in the surface sheet 2 is further given to the wearer's skin can be further reduced. it can.

  In the present embodiment, each of the plurality of convex portions 21 has a solid structure as shown in FIG. Thus, when each of the plurality of convex portions 21 has a solid structure, each convex portion 21 is not easily crushed and the liquid is transferred from each convex portion 21 that is easily in contact with the wearer's body to the absorbent body 4. Since it is excellent in the property, the dryness of the surface of each convex part 21 can be improved.

On the other hand, the 2nd fiber layer 2b has a substantially flat structure except the below-mentioned hollow part 23 formed by pressing. However, the second upper surface 2bE of the second fiber layer 2b may be slightly raised upward in the thickness direction T at a position corresponding to the convex portion 21.
The second fiber layer 2b extends continuously along the longitudinal direction L and has a predetermined interval in the width direction W in the same manner as the first fiber layer 2a (however, opposite to the thickness direction T). The second lower surface 2bF is disposed between the plurality of convex portions protruding downward (non-skin side) and the convex portions continuously extending along the longitudinal direction L and adjacent to each other. 2 The lower surface 2bF may have a plurality of recesses that are recessed upward (skin side). In that case, it is preferable that the positions of the convex portions 21 and the concave portions 22 of the first fiber layer 2a correspond to the positions of the convex portions and the concave portions of the second fiber layer 2b in the thickness direction T.

  The first fiber layer 2a and the second fiber layer 2b are joined to each other by entanglement. Examples of the entanglement method include a spunlace method and a water jet method. However, the confounding method is not limited to this example, and other confounding methods such as an air through method may be used.

In the present embodiment, the fiber density of the top portion 21T of the convex portion 21 is S1, the fiber density of the bottom portion 22B of the concave portion 22 is S2, and the region MP between the top portion 21T of the convex portion 21 and the bottom portion 22B of the concave portion 22 is MP. When the fiber density of S3 is S3, the relationship of S1 <S3 <S2 is satisfied.
When the sanitary napkin 1 has such a configuration, the top sheet 21 has a medium (medium density) fiber density S3 from the top 21T of the convex portion 21 having a sparse (low density) fiber density S1. Capillary phenomenon tends to work toward the bottom portion 22B of the concave portion 22 having the dense (high density) fiber density S2 through the region MP having the surface MP, so that the surface on the most skin side of the surface sheet 2 (that is, the convex portion 21) The liquid excretion excreted in the top portion 21T or the vicinity thereof can be more easily drawn into the bottom portion 22B of the concave portion 22 located in the vicinity of the surface on the non-skin side of the topsheet 2. Thereby, a liquid excretion can be more stably moved from the skin side surface of the surface sheet 2 to the absorber 4 (and the auxiliary sheet 5) through the non-skin side surface of the surface sheet 2.
Moreover, the surface sheet 2 can make liquid return of the liquid excrement once absorbed difficult by the fiber density gradient (S1 <S3 <S2), and further, the fiber density of the convex portion 21 is low. Since the soft feel can be provided to the wearer, the topsheet 2 can improve the absorption performance while improving the touch.
In addition, the sanitary napkin 1 does not need to have said uneven structure in the surface sheet 2, and also does not need to have said fiber density gradient.

Moreover, in this embodiment, as shown in FIG. 4, as for the surface sheet 2, in each of several recessed part 22, the 1st fiber layer 2a and the 2nd fiber layer 2b are thickness directions by processing means, such as embossing. It has a plurality of depressions 23 that are compressed by T. The plurality of depressions 23 are intermittently arranged along the longitudinal direction L in each recess 22 and at regular intervals or non-equal intervals.
In addition, in the recessed part 22 adjacent to the width direction W, the recessed part 23 may be a position on the same straight line in the longitudinal direction L, or may be a position not lined up on the same straight line. In the present embodiment, the plurality of depressions 23 are arranged in a checkered pattern with respect to the recess 22 as shown in FIG. In addition, the shape of each of the plurality of depressions 23 in plan view is not particularly limited, and may be elliptical as in the present embodiment or any other shape.
When the sanitary napkin 1 has such a configuration, the first fiber layer 2a and the second fiber layer 2b are fixed in the thickness direction T by squeezing in each of the plurality of depressions 23 (that is, water retention fibers F ₁ is by) that has been compressed in the first fibrous layer 2a, fuzz by water retention fibers F ₁ is less likely to occur, can be further favorably maintained soft topsheet 2.
In addition, the sanitary napkin 1 does not need to equip the surface sheet 2 with such a plurality of hollow parts 23.

(Auxiliary sheet)
In the present embodiment, as shown in FIG. 1, the auxiliary sheet 5 extends in the longitudinal direction L from the longitudinal end portion on the front side to the longitudinal end portion on the rear side of the sanitary napkin 1 in plan view. It has a substantially rectangular vertically long plan view shape. As shown in FIG. 2, the auxiliary sheet 5 is disposed between the top sheet 2 and the absorbent body 4 in the thickness direction T of the sanitary napkin 1, and removes liquid excrement that has permeated through the top sheet 2. It is comprised by the liquid-permeable sheet-like member made to transfer to the skin side absorber 4. As shown in FIG.

  The liquid-permeable sheet-like member that can be used as the auxiliary sheet 5 is not particularly limited as long as the effect of the present invention is not impaired, and examples thereof include liquid-permeable nonwoven fabrics and woven fabrics, and composite sheets in which these are laminated. .

In the present embodiment, the auxiliary sheet 5 positioned on the non-skin side of the topsheet 2 includes the plurality of recesses 22 of the topsheet 2 (more specifically, the second lower surface 2bF corresponding to each of the recesses 22). And) by any joining means such as an adhesive or a heat-fusing means. Thus, the auxiliary sheet 5 and the topsheet 2 and are joined together at each of the plurality of recesses of the topsheet 2, the junction of the auxiliary sheet 5 and the topsheet 2 holds the water retention fibers F ₁ Thus, the above-described water retention fiber F ₁ can be made more difficult to fuzz.

Furthermore, as shown in FIG. 2, the auxiliary sheet 5 in the present embodiment has a slightly larger shape in the width direction W than the top sheet 2, and a pair of loop portions 5 </ b> L at both ends in the width direction W. 5L is formed. In the pair of loop portions 5L and 5L, both end portions in the width direction W of the auxiliary sheet 5 are folded in a loop shape on the inner side in the width direction W of the auxiliary sheet 5 and on the non-skin side (below the thickness direction T). It is formed by being.
Both ends of the folded auxiliary sheet 5 are sandwiched between the top sheet 2 and the pair of side sheets 6, 6, and the pair of inward side ends facing the pair of side sheets 6, 6, and the longitudinal direction L Are joined to each other via a pair of adhesive portions (not shown) extending intermittently or continuously. The loop portion 5L does not include an elastic member.
Moreover, as for each of the both ends of the folded auxiliary sheet 5, the inner surfaces of the loop part 5l (that is, the non-skin-side surfaces of the auxiliary sheet 5 before folding) are intermittent or continuous along the longitudinal direction L. Are joined to each other via a pair of adhesive portions extending in the direction.

Usually, in the surface sheet containing a large amount of water-retaining fibers, when the edges are rubbed, the water-retaining fibers are easily loosened from the edges and easily fall off. In this embodiment, the dimension in the width direction W of the auxiliary sheet 5 is The dimension of the top sheet 2 is larger than the dimension in the width direction W. That is, the portion of the auxiliary sheet 5 on the outer side of both edges in the width direction W of the top sheet 2 in the plan view is the width direction W. The pair of extending portions are formed to extend outward, and as the pair of extending portions, the pair of loop portions 5L and 5L described above are formed at both ends in the width direction W of the auxiliary sheet 5 as the pair of extending portions. Since it is formed, the force received by the sanitary napkin 1 from the wearer's thigh can be received by the pair of loop portions 5L and 5L (a pair of extending portions), and both ends in the width direction W of the topsheet 2 The edge and thigh can be made hard to rub, Water retention fibers F ₁ can be unlikely to occur to fall off loose from both edges in the width direction W of the topsheet 2.
Furthermore, when the above-described pair of loop portions 5L and 5L are used as the pair of extending portions, the force received by the sanitary napkin 1 from the wearer's thigh is softly received by the cushioning action of the pair of loop portions 5L and 5L. The tactile sensation given to the wearer can be improved. In particular, water retention fibers F ₁ is the case of the cotton fibers, their effect is remarkable.

Moreover, in this embodiment, the auxiliary sheet 5 has a fiber density higher than the fiber density of the 2nd fiber layer 2b. When the sanitary napkin 1 has such a configuration, the liquid excretion drawn into the second fiber layer 2b can be more stably transferred to the auxiliary sheet 5 by capillary action. The liquid excrement can be more stably transferred from 2 to the absorbent body 4 via the auxiliary sheet 5, and as a result, the absorption performance can be improved while improving the touch of the topsheet 2. .
The sanitary napkin 1 may not include the auxiliary sheet 5 or the loop portion 5L.

In addition, when the auxiliary sheet 5 includes the water retaining fiber F ₁ corresponding to the surface sheet 2 and the surface sheet 2 includes the cellulosic fiber (preferably cotton fiber), the auxiliary sheet 5 includes the cellulosic fiber ( Preferably, it contains cotton fiber). When the sanitary napkin 1 has such a configuration, the water-retaining water-retaining fiber F ₁ , preferably a cellulosic fiber, more preferably a cotton fiber, is formed from the first fiber layer 2 a of the top sheet 2. Since it exists so as to communicate with the auxiliary sheet 5 through the two-fiber layer 2b, the absorbent body 4 from the top sheet 2 through the auxiliary sheet 5 by utilizing the liquid diffusion of the liquid excreta by these fibers. The liquid excrement can be transferred more stably, and as a result, the absorption performance can be further improved while improving the touch of the topsheet 2.
In the sanitary napkin 1, the auxiliary sheet 5 may not contain water-retaining fibers, cellulosic fibers, or cotton fibers. In that case, as the auxiliary sheet 5, for example, a nonwoven fabric made of thermoplastic resin fibers can be used.

  In the present invention, the dimensional shape, thickness, etc. of the auxiliary sheet are not particularly limited as long as the effects of the present invention are not impaired, and any dimensional shape, thickness, etc. according to the desired absorption performance, flexibility, etc. are adopted. be able to.

(Absorber)
In the above-described embodiment, as shown in FIG. 1, the absorbent body 4 extends in the longitudinal direction L across the longitudinal center line C _L and the width center line C _W of the sanitary napkin 1 in plan view. In addition, it extends in a wide range in the width direction W, and has a vertically long plan view shape in which both end portions in the longitudinal direction L protrude so as to draw an arc toward the outer side in the longitudinal direction L. As shown in FIG. 2, the absorbent body 4 is disposed between the top sheet 2 and the back sheet 3 (more specifically, between the auxiliary sheet 5 and the back sheet 3) in the thickness direction T of the sanitary napkin 1. It is formed by a water-absorbing member having predetermined liquid absorption performance and liquid retention performance that can be disposed and absorb and retain liquid excretion such as menstrual blood that has permeated through the top sheet 2.

  In the present invention, the water-absorbing member that can be used as an absorber is not particularly limited as long as it can absorb and retain at least liquid excretion such as menstrual blood, and any water-absorbing member known in the art is adopted. can do. Examples of such a water-absorbing member include those in which at least one absorbent core composed of any water-absorbing material is covered with a core wrap sheet such as a hydrophilic tissue. Here, examples of the water-absorbing material constituting the absorbent core include hydrophilic fibers and superabsorbent polymers. More specifically, cellulose fibers such as pulverized pulp, cotton, rayon, acetate, etc .; acrylic Examples thereof include granular materials composed of a superabsorbent polymer such as sodium acid copolymer; and mixtures of these arbitrarily combined.

In the above-mentioned embodiment, the absorber 4 is comprised by the absorptive core 4a which consists of a water absorbing material, and the core wrap 4b which coat | covers it.
In addition, when the surface sheet 2 contains a cellulosic fiber (preferably cotton fiber), it is preferable that the absorber 4 contains a cellulosic fiber (preferably cotton fiber) corresponding to the surface sheet 2. In that case, it is preferable that a part of the cellulosic fibers contained in the surface sheet 2 is in contact with the cellulosic fibers contained in the absorbent body 4. When the sanitary napkin 1 has such a configuration, highly diffusible cellulosic fibers are passed through the first fiber layer 2a to the second fiber layer 2b of the top sheet 2 (in some cases, an auxiliary sheet). 5), the liquid excrement is transferred from the surface sheet 2 to the absorber 4 by utilizing the liquid diffusion of the liquid excretion by the cellulosic fiber. It can be diffused directly, and as a result, the absorption performance can be further enhanced.
In the sanitary napkin 1, the absorbent body 4 may not contain cellulosic fibers or cotton.

  In the present invention, the shape of the absorbent body in plan view, various dimensions, basis weight and the like are not particularly limited as long as they can be used as the absorbent body of the absorbent article, and according to the desired absorption performance, flexibility, strength, and the like. Arbitrary planar shapes (for example, a rectangle, an ellipse, an hourglass, etc.), various dimensions, basis weight, etc. can be adopted.

  Further, in the present invention, when the absorbent article has a predetermined absorbent performance as a whole absorbent article by a constituent member other than the absorber (for example, a surface sheet or the like), the absorbent article is Such an absorber may not necessarily be provided.

(Side seat)
In the above-described embodiment, the pair of side sheets 6, 6 is a pair of strips extending in the longitudinal direction L at both ends in the width direction W of the sanitary napkin 1 in plan view, as shown in FIG. 1. It has the shape of The pair of side sheets 6, 6 are positioned on the non-skin side of the top sheet 2 at both ends in the width direction W of the sanitary napkin 1, and the liquid excrement supplied to the skin side surface of the top sheet 2 The napkin 1 is formed of a hydrophilic or water-repellent sheet-like member that functions to diffuse in the longitudinal direction L while blocking so as not to leak outward in the width direction W.

  The hydrophilic or water-repellent sheet-like member that can be used as the side sheet 6 is not particularly limited as long as it can function as a side sheet. For example, a nonwoven fabric constituted by fibers having hydrophilicity or water repellency, hydrophilization Examples thereof include a nonwoven fabric subjected to treatment or water repellent treatment, and a synthetic resin film having air permeability.

  Further, in the sanitary napkin 1 of the present embodiment, the pair of side sheets 6 and 6 have a dynamic friction coefficient when wet that is lower than that when the top sheet 2 is wet. The pair of side sheets 6, 6 that are easy to touch the skin around the wearer's legs have a lower dynamic friction coefficient than the above-described surface sheet 2 that is excellent in the touch, so that the sanitary napkin 1 has a smoother touch. Can be provided.

Here, the dynamic friction coefficient when wet can be measured according to the following method.
(1) The surface sheet and the side sheet of the absorbent article are cut, and a sample having a width direction of 40 mm and a longitudinal direction of 80 mm is cut out. In addition, when these sheets cannot be separated by an adhesive such as a hot melt (HMA) type adhesive, the adhesive is washed off with toluene and dried in the air for 24 hours.
(2) 10 mm in the longitudinal direction of each sample is fixed to a horizontal plate using a gum tape (ASKUL Co., Ltd .: “On-site power” cloth tape 0.26 mm thickness 50 mm width × 25 m length roll).
(3) Kanakin (50 mm x 40 mm, JIS L 0803 compliant) Dyeing fastness with a digital force gauge (Nidec Symposium, FGP-0.5 (FGP-2)) and an end of 10 mm on each sample. Attached white cloth for degree test, Japanese Standards Association, single fiber cloth). Further, a 525 g weight which is a rectangular parallelepiped having a bottom surface of 35 mm × 25 mm is placed thereon.
(4) Kanakin moistened approximately averagely with a predetermined amount of ion-exchanged water is moved 30 mm on the sheet at a speed of 100 mm / min, and the maximum value displayed at that time is taken as the dynamic friction coefficient. At this time, Kanakin is applied to the skin side surface of each sample.
In this measurement method, the wet skin of the wearer is reproduced by wetting the canakin, and the amount of skin moisture to be reproduced is 60% when wet.
Therefore, the predetermined amount of ion-exchanged water is 60% by mass with respect to the mass of canakin. Specifically, when the 40 mm × 50 mm kanakin is 50 g / m ² , the volume is 0.06 mL (50 g / m ² × 0.04 m × 0.05 m × 60%).
If the sheet cannot be collected with the above width dimensions, the sample is collected at the maximum width that can be collected and measured. Then, a weight that fits within the sheet area and that is 30 g / cm ² and a weight of +10 mm (digital force gauge connection part) is placed on the sheet, and the maximum distance is moved on the sheet at a speed of 100 mm / min. Let the maximum value displayed at that time be the dynamic friction coefficient.

  In this embodiment, the coefficient of dynamic friction when the top sheet 2 is wet is 0.80, and the coefficient of dynamic friction when the side sheet 6 is wet is 0.49. Further, the difference between the dynamic friction coefficient of the top sheet 2 and the dynamic friction coefficient of the side sheet 6 can be set to 0.1 or more and 0.25 or less, for example. When the difference in the dynamic friction coefficient is within such a range, the wearer can easily feel the difference in surface characteristics between the topsheet 2 and the sidesheet 6.

In addition, the pair of side sheets 6 and 6 having a low dynamic friction coefficient can be obtained by using a low friction material as a material for forming the side sheets 6 and 6 (for example, constituent fibers of a nonwoven fabric), or It can form by coat | covering the low friction material on the skin side surface of the well-known sheet-like member used as a sheet | seat.
In addition, the low friction material that can be used for the side sheet is not particularly limited, for example, an olefin resin such as polyethylene or polypropylene, a resin having a low coefficient of friction such as a silicone resin, a fluororesin such as polytetrafluoroethylene, or the like. Examples thereof include resin compositions containing these resins.
In addition, the pair of side sheets 6 and 6 may not have a lower dynamic friction coefficient when wet when the top sheet 2 is wet.

  In the present invention, the plan view shape and various dimensions of each of the pair of side sheets are not particularly limited as long as they can be used as the side sheets of the absorbent article, and correspond to desired leakage prevention performance, absorption performance, and the like. Arbitrary planar view shapes and various dimensions can be adopted.

  Moreover, since it is not an essential constituent requirement in the absorbent article of the present invention that the absorbent article includes such a pair of side sheets, the absorbent article does not include such a pair of side sheets. May be.

(Back sheet)
In the sanitary napkin 1 of the above-described embodiment, as shown in FIG. 1, the back sheet 3 is long in the plan view from the front side longitudinal end of the sanitary napkin 1 to the rear side longitudinal end. It extends in the direction L and has a vertically long plan view shape extending in the width direction W from the width direction end on one side in the width direction W of the sanitary napkin 1 to the width direction end on the other side. Yes. As shown in FIG. 2, the back sheet 3 is disposed at a position on the non-skin side in the thickness direction T of the sanitary napkin 1, and the liquid that has permeated the absorbent body 4 or has oozed out of the absorbent body 4. The liquid impervious sheet-like member functions to prevent excrement from leaking out of the sanitary napkin 1.

  The liquid-impermeable sheet-like member that can be used as the back sheet 3 prevents permeation of liquid excretion such as menstrual blood discharged from the wearer so that the liquid excretion does not leak into the wearer's clothes and the like. In particular, any hydrophobic thermoplastic resin fibers (for example, polyolefin fibers such as PE and PP, polyester fibers such as polyethylene terephthalate (PET), core sheath) Non-woven fabrics formed by hydrophobic composite resins such as PE and PP; and non-woven fabrics bonded to the resin films. Any liquid-impermeable sheet-like member such as a laminated nonwoven fabric such as an SMS nonwoven fabric can be used.

  The plan view shape, various dimensions, basis weight, and the like of the back sheet 3 are not particularly limited as long as they can be used as the back sheet, and any plan view according to desired leakage prevention performance, air permeability, strength, and the like. Shape, various dimensions, basis weight, etc. can be adopted.

  Further, in the sanitary napkin 1 of the present embodiment, the top sheet 2 is joined to the auxiliary sheet 5 with an adhesive or the like (for example, a hot melt type adhesive or the like), and the auxiliary sheet 5 and the pair of side sheets 6 and 6 are combined. The portion facing each of the absorber 4 is bonded to the absorber 4 with an adhesive or the like, and further, the portion facing each of the pair of side sheets 6 and 6 and the back sheet 3 in each of the absorbers 4 It is joined to the back sheet 3 by an adhesive or the like.

(Adhesive part)
In this embodiment, the sanitary napkin 1 is for fixing the sanitary napkin 1 to the wearer's clothes (for example, underwear etc.) on the non-skin side surface of the back sheet 3, as shown in FIG. A plurality of adhesive portions 7 and a pair of adhesive portions 8 and 8 are further provided.
The plurality of adhesive portions 7 are disposed on the non-skin side surface of the back sheet 3 so as to overlap the absorber 4 in the thickness direction T, extend continuously in the longitudinal direction L, and intermittently in the width direction W. It has a plurality of stripes (a plurality of substantially rectangular shapes) arranged in a plan view.
The pair of adhesive portions 8, 8 are arranged on the non-skin side surface of the back sheet 3 so as to overlap the pair of wing portions 9, 9 in the thickness direction T, and continuously extend in the longitudinal direction L. It has a substantially rectangular shape in plan view.

  In addition, these adhesion parts 7 and 8 will not be restrict | limited especially if each can fix the sanitary napkin 1 to a wearer's clothing, For example, it can form with arbitrary adhesives, such as a styrene-type polymer. it can.

  Moreover, since it is not an essential constituent requirement in the absorbent article of this invention that an absorbent article is equipped with such an adhesion part, the absorbent article does not need to be equipped with such an adhesion part.

[Production method]
Next, the manufacturing method of the surface sheet 2 of the sanitary napkin 1 according to the above-described embodiment will be exemplarily described.

(Second fiber web forming step)
First, the water retaining fiber F ₁ and the thermoplastic resin fiber F ₂ for forming the second fiber layer 2b are supplied to the first card machine (for example, a dry roller card using a single card or a double card). A second fiber web corresponding to the second fiber layer 2b is formed. The second fiber web is transported in the transport direction MD by the transport device.

(First fiber web forming step)
Then, water retention fibers F ₁ for forming a first fibrous layer 2a is provided in the second carding machine (the first carding machine and the same dry roller cards), corresponding to the first fiber layer 2a A first fibrous web is formed.

(Fiber web lamination process)
The formed 1st fiber web is laminated | stacked on the 2nd fiber web currently conveyed with a conveying apparatus. Thereby, a composite fiber web having a two-layer structure in which the first fiber web and the second fiber web are laminated is formed.
In addition, the ratio of each fiber in each fiber web is controllable by the ratio of the raw material fiber supplied to each card machine.

(Entanglement process)
Next, the composite fiber web having a two-layer structure is subjected to water jet processing by a water jet processor, and the fibers in the composite fiber web are hydroentangled with each other. Thereby, a composite fiber sheet (spunlace nonwoven fabric) is formed.
In this manner, the fibers in the composite fibrous web are generally entangled by hydroentangling, on things like falling out by unraveling water retention fibers F _1, such as cotton fibers is less likely, even better feel It becomes easy to obtain.

Here, in the above-described water jet treatment, a high-pressure jet water stream is jetted from the upper surface side to the composite fiber web placed on the mesh belt that moves continuously, and the action of the water stream causes The fibers are entangled.
The properties of the composite fiber sheet obtained by the water jet treatment can be appropriately adjusted depending on the mass of each fiber web, the hole diameter of the injection nozzle, the number of holes (pitch) of the injection nozzle, the moving speed of the fiber web, and the like.

  In addition, the formation method of the fiber web corresponding to each fiber layer is not limited to the said method, For example, you may employ | adopt a wet method etc. Further, the web bonding method is not limited to the above-described method. For example, the air-through method (that is, the composite fiber web is transported to a heating device, and the fibers in the composite fiber web are bonded to each other by heated air in the heating device. A entanglement method) or a needle punch method may be employed.

(Drying process)
The composite fiber sheet that has passed through the water jet processor is conveyed to a dryer (heated hot air oven) and dried with hot air.

(Heat treatment process)
Furthermore, the dried composite fiber sheet is conveyed to a heat treatment apparatus (heated hot air oven) and is heat-treated with hot air at a predetermined temperature. By this heat treatment, at least a part of the thermoplastic resin fibers F ₂ in the composite fiber sheet is melted, and the melt F _2M flows in the composite fiber sheet and exists in a portion corresponding to the first fiber layer 2a. adhering like water retention fibers F ₁ at confounding portions P _E of the water-retentive fiber F ₁ and the composite fibers in the sheet. Thus, at least a portion of the water-retentive fiber F ₁ are included in the portion corresponding to at least a first fibrous layer 2a is, in at least some of the confounding portion P _E of the entangled portion P _E between fibers, a thermoplastic resin Covered by a melt F _2M of fibers F ₂ .

The conditions for the heat treatment are not particularly limited as long as the thermoplastic resin fiber F ₂ can be melted, but the thermoplastic resin fiber F ₂ is a core-sheath type composite fiber or a side-by-side type composite fiber. In the case of a conjugate fiber, a resin component having a low melting point exposed on the surface of the conjugate fiber (for example, a resin component constituting the sheath in the case of a core-sheath type conjugate fiber, one side in the case of a side-by-side type conjugate fiber) It is preferable to employ a temperature condition in which only the resin component) is melted.
Moreover, you may use together the apparatus (namely, dryer and heat processing apparatus) used for the drying after the above-mentioned water jet process, and subsequent heat processing.

(Shaping process)
Next, the composite fiber sheet after the heat treatment is supplied to the shaping device while being conveyed in the conveyance direction MD. Here, the shaping apparatus is provided with a pair of shaping rolls extending in the circumferential direction on the outer peripheral surface and having a concave portion and a convex portion that mesh with each other, and the composite fiber sheet after the heat treatment is a pair of shaping rolls. The specific concavo-convex structure that is sandwiched between the concave and convex portions and extends in the transport direction MD is shaped.
In addition, when the surface sheet 2 does not have such a specific uneven structure, the shaping step may be omitted.
In this way, a composite fiber shaped sheet for the top sheet 2 is formed. The composite fiber shaped sheet is laminated with a sheet-like member for other constituent members of the sanitary napkin 1, and then cut into the shape of the sanitary napkin 1 to become a top sheet 2.

  In addition to the sanitary napkin of the above-described embodiment, the present invention can be applied to various absorbent articles such as a panty liner, a (light) incontinence pad, and a disposable diaper. In addition, the absorbent article of the present invention is not limited to the above-described embodiment and examples to be described later, and can be appropriately combined, substituted, changed, and the like without departing from the object and spirit of the present invention. is there.

In addition, the nonwoven fabric provided with the 1st fiber layer and the 2nd fiber layer used for the surface sheet of the absorbent article of the present invention is a nonwoven fabric that hardly gives unpleasant irritation to the user's skin and is excellent in the touch. Therefore, it can be applied to other sheet-like members (for example, side sheets and exterior sheets) that require a good touch, and furthermore, sanitary products other than absorbent articles (for example, masks and dirt wiping sheets) Further, it can be applied to nonwoven fabrics used for face masks, cosmetic sheets, puffs (eg, cotton puffs).
When applied to such a nonwoven fabric, the nonwoven fabric is a nonwoven fabric having a first surface and a second surface,
The nonwoven fabric is
A first fiber layer comprising water retention fibers and forming the first surface of the nonwoven fabric;
A second fiber layer that includes thermoplastic resin fibers and water retention fibers, and that forms the second surface of the nonwoven fabric adjacent to the second surface side of the first fiber layer, and
The ratio of the water retention fiber in the fibers constituting the first fiber layer is greater than the ratio of the water retention fiber in the fibers constituting the second fiber layer,
At least a part of the water-retaining fibers contained in the first fiber layer is covered with a melt of the thermoplastic resin fiber in at least a part of the entangled part of the fibers. It becomes a non-woven fabric.

  Hereinafter, the present invention will be described more specifically by way of examples and comparative examples. However, the present invention is not limited to these examples.

  A surface sheet (Example) that can be used for the absorbent article of the present invention and a surface sheet (Comparative Example) that does not satisfy the constituent requirements of the present invention were produced, and the occurrence of fluff was verified.

Example 1
First, as water retention fibers and thermoplastic resin fibers for forming the second fiber layer, cotton fibers (fiber length 5 mm to 35 mm, basis weight 16 g / m ² ) and core-sheath type composite fibers (core part: PP, (Sheath part: PE, fiber length 38 mm, basis weight 4 g / m ² ) were prepared, and these fibers were supplied to the first card machine to form a second fiber web corresponding to the second fiber layer (second). Fiber web forming step). The mixing ratio (mass ratio) of the cotton fiber and the core-sheath type composite fiber in the second fiber web was set to cotton fiber: core-sheath type composite fiber = 60: 40.
Next, only cotton fibers (fiber length 20 mm to 35 mm, basis weight 10 g / m ² ) are prepared as water retention fibers for forming the first fiber layer, and the cotton fibers are provided to the second card machine, A first fiber web corresponding to one fiber layer was formed (first fiber web forming step).
And the formed 1st fiber web was laminated | stacked on the 2nd fiber web currently conveyed with a conveying apparatus, and the composite fiber web of the two-layer structure by which the 1st fiber web and the 2nd fiber web were laminated | stacked was formed. (Fiber web laminating step) After this, the composite fiber web is subjected to water jet treatment by a water jet processor, and the fibers in the composite fiber web are hydroentangled to obtain a composite fiber sheet (spunlace nonwoven fabric). (Entanglement process).
The composite fiber sheet that passed through the water jet processor was conveyed to a dryer (heated hot air oven) and dried with hot air at 70 ° C. (drying step).
Furthermore, the dried composite fiber sheet is conveyed to a heat treatment device (heated hot air oven) and heat-treated with hot air at 130 ° C., and the cotton-sheathed melted core-sheath composite fiber at the entangled portion of the fibers. (Specifically, a melt of PE in the sheath) was coated (heat treatment step).
Next, the composite fiber sheet after the heat treatment is supplied to a shaping apparatus including a pair of shaping rolls having a concave portion and a convex portion that mesh with each other, and is sandwiched between the concave portion and the convex portion of the pair of shaping rolls. The concavo-convex structure extending in the transport direction MD was shaped (shaped process).
Thus, the composite fiber shaped sheet | seat in which the uneven structure was shaped was cut | disconnected to the defined shape, and the surface sheet of Example 1 was obtained.

Comparative Example 1
A surface sheet of Comparative Example 1 was obtained in the same manner as in Example 1 except that the heat treatment step and the shaping step were not performed.

Comparative Example 2
Only a cotton fiber (fiber length 20 mm to 35 mm, basis weight 30 g / m ² ) was used as a fiber for forming the top sheet (that is, the top sheet was made of a fiber layer having a single layer structure without a second fiber layer ( The surface sheet of Comparative Example 2 was obtained in the same manner as in Example 1 except that the cotton fiber layer) was not used, and the heat treatment step and the shaping step were not performed.

The surface sheet of Example 1, the state of the first fiber layer was observed by a scanning electron microscope, cotton fiber (water-retentive fiber F ₁₎ is a core-sheath composite yarn in entangling portions P _E between fibers (heat It was confirmed that it was covered with a melt of the plastic resin fiber F ₂ ) (specifically, a melt of PE in the sheath portion) F _2M . The confirmation result (that is, the electron micrograph of the first fiber layer in the top sheet of Example 1) is shown in FIG.

  Further, for each surface sheet of Example 1, Comparative Example 1 and Comparative Example 2, the occurrence state of fluff of each surface sheet was comparatively evaluated according to the following <Method for evaluating fluff by friction fastness test>. The evaluation results (namely, comparative photographs showing the occurrence of fluffing in Example 1 and Comparative Examples 1 and 2) are shown in FIG.

<Evaluation method of fuzz by friction fastness test>
(1) A measurement target region is obtained by cutting out a measurement target region from a non-woven fabric constituting the surface sheet with a predetermined size (for example, 80 mm × 40 mm).
(2) A measurement sample is fixed on a measurement stage of a dyed product friction fastness tester (manufactured by Daiei Kagaku Seiki Seisakusho Co., Ltd.).
(3) Attach a 200 g weight to the upper surface of the friction terminal of the dyeing section friction fastness tester, and affix a cloth tape that forms a friction surface on the lower surface.
(4) The surface of the measurement sample fixed on the measurement stage is rubbed with the friction surface of the friction terminal. At this time, the number of reciprocations of the friction terminal is 100 and 200, and the movement range (reciprocation width) of the friction terminal is 60 mm. The items “0T”, “100T”, and “200T” shown in FIG. 6 indicate that the number of reciprocations of the friction terminal in the friction fastness test (FF) is “0”, “100”, and “200”, respectively. "Means.
(5) Observe the fluffing state on the surface of the measurement sample after rubbing with a friction terminal.

As shown in FIG. 6, the surface sheet of Example 1 in which the heat treatment was performed and the cotton fibers were covered with the melt of the core-sheath type composite fibers at the entangled portions of the fibers was rubbed 200 times with the friction terminals. After that, it was found that the fluff was hardly generated and the touch was excellent (see the photograph in the column A in FIG. 6).
On the other hand, it was found that the surface sheets of Comparative Example 1 and Comparative Example 2 that were not subjected to heat treatment were fluffed even when rubbed 100 times with a friction terminal, and the touch was reduced (see FIG. 6 (see photographs in column B (Comparative Example 1) and column C (Comparative Example 2)).

1 Sanitary napkin (an example of an absorbent article)
2 surface sheet 2a 1st fiber layer 2b 2nd fiber layer 3 back sheet 4 absorber 5 auxiliary sheet 6 side sheet F ₁ water retention fiber F ₂ thermoplastic resin fiber F _2M melt

Claims (13)

An absorbent article including a face sheet,
The surface sheet is
A first fiber layer containing water retention fibers and forming a skin side surface of the top sheet;
A second fiber layer that includes a thermoplastic resin fiber and a water retention fiber and forms a non-skin side surface of the top sheet adjacent to the non-skin side of the first fiber layer;
With
The ratio of the water retention fiber in the fibers constituting the first fiber layer is greater than the ratio of the water retention fiber in the fibers constituting the second fiber layer,
At least a part of the water retaining fibers contained in the first fiber layer is covered with a melt of the thermoplastic resin fiber in at least a part of the entangled part of the fibers.
The absorbent article. In the thermoplastic resin fiber, one thermoplastic resin fiber is entangled with a plurality of the water retention fibers,
The absorptivity according to claim 1, wherein each of the entangled portions of the one thermoplastic resin fiber and the plurality of water retaining fibers is covered with a melt of the one thermoplastic resin fiber. Goods.   The absorbent article according to claim 1 or 2, wherein a melt of the thermoplastic resin fibers is not exposed on a skin side surface of the first fiber layer.   The absorbent article as described in any one of Claims 1-3 whose average fiber length of the said water retention fiber contained in a said 1st fiber layer is shorter than the average fiber length of the said thermoplastic resin fiber.   The absorbent article as described in any one of Claims 1-4 whose average fiber length of the said water retention fiber contained in a said 1st fiber layer is 5 mm or more and less than 35 mm. The thermoplastic resin fiber is a composite fiber,
The said composite fiber is an absorbent article as described in any one of Claims 1-5 in which the resin component with low melting | fusing point is exposed on the surface of the said composite fiber.   The said surface sheet is an absorptive article as described in any one of Claims 1-6 which has a pressing part dented in the thickness direction from the skin side surface. The surface sheet is
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;
The absorbent article as described in any one of Claims 1-7 which has these. The absorbent article further includes an auxiliary sheet located on the non-skin side of the top sheet,
The absorbent article according to claim 8, wherein the surface sheet is joined to the auxiliary sheet in each of the plurality of recesses.   The absorptive article according to any one of claims 1 to 9 in which said water retention fiber is organic cotton.   The absorbent article as described in any one of Claims 1-10 whose fiber density of a said 2nd fiber layer is larger than the fiber density of a said 1st fiber layer.   The absorbent article according to any one of claims 1 to 11, wherein an average distance between the fibers of the second fiber layer is shorter than an average distance between the fibers of the first fiber layer. The absorbent article further includes a pair of side sheets positioned on the skin side of the top sheet at both ends in the width direction,
The absorbent article according to any one of claims 1 to 12, wherein the pair of side sheets has a lower coefficient of dynamic friction when wet than a coefficient of dynamic friction when the top sheet is wet.