WO2020004554A1

WO2020004554A1 - Nonwoven fabric for absorbent articles, back sheet for absorbent articles, absorbent article and method for producing nonwoven fabric for absorbent articles

Info

Publication number: WO2020004554A1
Application number: PCT/JP2019/025619
Authority: WO
Inventors: 保紀中村
Original assignee: ダイワボウホールディングス株式会社; ダイワボウポリテック株式会社
Priority date: 2018-06-27
Filing date: 2019-06-27
Publication date: 2020-01-02
Also published as: JP2021045177A

Abstract

A nonwoven fabric for absorbent articles, which comprises a first fiber layer and a second fiber layer that is positioned on one main surface of the first fiber layer, and which is configured such that: the first fiber layer contains first sheath-core type composite fibers; the second fiber layer contains second sheath-core type composite fibers and cotton; the fineness (F1) of the first sheath-core type composite fibers is lower than the fineness (F2) of the second sheath-core type composite fibers; the value of (F2 - F1) is from 0.1 dtex to 1.5 dtex (inclusive); and the requirements described below are satisfied. (i) The sheath component of the first sheath-core type composite fibers and the sheath component of the second sheath-core type composite fibers contain a polyethylene; the heat of fusion ∆H of the sheath component of the first sheath-core type composite fibers is 130 J/g or more; and the heat of fusion ∆H of the sheath component of the second sheath-core type composite fibers is 130 J/g or more.

Description

Nonwoven fabric for absorbent article, backsheet and absorbent article for absorbent article, and method for producing nonwoven fabric for absorbent article

The present invention relates to a nonwoven fabric for an absorbent article, a backsheet and an absorbent article for an absorbent article, and a method for producing a nonwoven fabric for an absorbent article.

Absorbent articles such as disposable diapers, sanitary napkins, incontinence pads, panty liners, and the like include, besides the absorber, a sheet (also referred to as a “top sheet” in some documents) located on the skin side of the user, And a sheet (also referred to as a “back sheet” in some documents) located on the side opposite to the skin side (outside) of the user and on the clothes side of the user.

Patent Literature 1 discloses that a back sheet is required to be hard for a user to feel stuffy between an absorbent article and a user's clothes.
In order to solve the problem, Patent Document 1 discloses a laminated nonwoven fabric having a two-layer structure of a clothing side layer and a skin side layer as a back sheet (exterior sheet). The clothing side layer of the laminated nonwoven fabric is made of PET / PE composite fiber (fineness 2.8 dtex, average fiber length 45 mm, basis weight 20 g / m ² ), and the skin side layer is made of two types of PET / PE composite fiber ( Composite fiber A: Fineness 2.2 dtex, average fiber length 45 mm, Composite fiber B: Fineness 1.7 detx, average fiber length 45 mm, total basis weight of fibers A and B 10 g / m ² ) and cotton (average about 27 mm, basis weight 3 g) / m ² ) (see Table 1, Examples 1 and 2 of Patent Document 1).
Patent Document 1 discloses that a disposable diaper obtained by using the laminated nonwoven fabric as a back sheet has a low transpiration rate after absorbing artificial urine, and is unlikely to be wet or stuffy (Patent Document 1 paragraph 1). No. 0105).

Japanese Patent No. 6090302

The backsheet is also required to have less fuzz and less breakage of the non-woven fabric while being required to have a better touch (smoothness and softness).

When a nonwoven fabric such as a back sheet contains cotton, as disclosed in Patent Document 1, cotton is likely to exist as an aggregate, and voids are likely to exist around the cotton aggregate. Among them, it is expected that the strength will be insufficient, and it will be a portion where fluffing or breakage of the nonwoven fabric is likely to occur. In Patent Literature 1, since voids are intentionally provided around the cotton, it is expected that fluff or breakage of the nonwoven fabric is likely to occur. However, Patent Literature 1 does not mention these problems at all.

On the other hand, cotton is a natural fiber and tends to be favored by consumers as a material for absorbent articles, and cotton can provide a good tactile sensation. Therefore, the demand for absorbent articles containing cotton is high.
Therefore, if cotton is used as the material of the nonwoven fabric to try to obtain a better tactile sensation, voids are likely to exist around the cotton, which is likely to exist as an aggregate, as described above, and the strength is insufficient in the nonwoven fabric. , Fuzzing is likely to occur, and it is expected that tearing of the nonwoven fabric may increase.

Accordingly, the present invention is a nonwoven fabric containing cotton as a natural material, which has a better feel (smoothness and softness), has less fuzz, and has less tearing of the nonwoven fabric. An object of the present invention is to provide a nonwoven fabric having an excellent balance between the two.

As a result of intensive studies, the present inventors have found that controlling the fineness of each of the first and second core-sheath composite fibers contained in the first and second fiber layers, the first and second core-sheath composites It has been found that a nonwoven fabric for an absorbent article which can solve the above-mentioned problems can be obtained by controlling each polyethylene of the sheath component of the fiber. Further, they have found that such a nonwoven fabric for absorbent articles is suitable for a back sheet, and have completed the present invention.

That is, the present invention provides, as one gist, a nonwoven fabric for an absorbent article,
A nonwoven fabric comprising a first fiber layer and a second fiber layer located on one main surface of the first fiber layer,
The first fiber layer includes a first sheath-core composite fiber,
The second fiber layer includes a second sheath-core composite fiber and cotton,
The fineness (F1) of the first sheath-core composite fiber is smaller than the fineness (F2) of the second sheath-core composite fiber (F1 <F2),
The difference (F2-F1) between the fineness (F1) of the first sheath-core composite fiber and the fineness (F2) of the second sheath-core composite fiber is 0.1 dtex or more and 1.5 dtex or less,
The sheath component of the first sheath-core composite fiber and the sheath component of the second sheath-core composite fiber include polyethylene,
The heat of fusion ΔH of the sheath component of the first core-sheath type composite fiber is 130 J / g or more;
The heat of fusion ΔH of the sheath component of the second core-sheath type composite fiber is 130 J / g or more.

In another aspect, the present invention provides a nonwoven fabric for an absorbent article,
A nonwoven fabric comprising a first fiber layer and a second fiber layer located on one main surface of the first fiber layer,
The first fiber layer includes a first sheath-core composite fiber,
The second fiber layer includes a second sheath-core composite fiber and cotton,
The fineness (F1) of the first sheath-core composite fiber is smaller than the fineness (F2) of the second sheath-core composite fiber (F1 <F2),
The difference (F2-F1) between the fineness (F1) of the first sheath-core composite fiber and the fineness (F2) of the second sheath-core composite fiber is 0.1 dtex or more and 1.5 dtex or less,
The sheath component of the first sheath-core composite fiber and the sheath component of the second sheath-core composite fiber both include at least one selected from high-density polyethylene and medium-density polyethylene.

Further, the present invention provides, as a further aspect, a nonwoven fabric for an absorbent article,
A nonwoven fabric comprising a first fiber layer and a second fiber layer located on one main surface of the first fiber layer,
The first fiber layer includes a first sheath-core composite fiber,
The second fiber layer includes a second sheath-core composite fiber and cotton,
The fineness (F1) of the first sheath-core composite fiber is smaller than the fineness (F2) of the second sheath-core composite fiber (F1 <F2),
The ratio (F1 / F2) of the fineness (F1) of the first core-sheath type composite fiber to the fineness (F2) of the second core-sheath type composite fiber is 0.55 or more, and is smaller than 1;
The sheath component of the first sheath-core composite fiber and the sheath component of the second sheath-core composite fiber include polyethylene,
The heat of fusion ΔH of the sheath component of the first core-sheath type composite fiber is 130 J / g or more;
The heat of fusion ΔH of the sheath component of the second core-sheath type composite fiber is 130 J / g or more.

Still further, the present invention provides, as yet another aspect, a nonwoven fabric for an absorbent article,
A nonwoven fabric comprising a first fiber layer and a second fiber layer located on one main surface of the first fiber layer,
The first fiber layer includes a first sheath-core composite fiber,
The second fiber layer includes a second sheath-core composite fiber and cotton,
The fineness (F1) of the first sheath-core composite fiber is smaller than the fineness (F2) of the second sheath-core composite fiber (F1 <F2),
The ratio (F1 / F2) of the fineness (F1) of the first core-sheath type composite fiber to the fineness (F2) of the second core-sheath type composite fiber is 0.55 or more, and is smaller than 1;
The sheath component of the first sheath-core composite fiber and the sheath component of the second sheath-core composite fiber both include at least one selected from high-density polyethylene and medium-density polyethylene.

In another aspect, the present invention provides a method for producing a nonwoven fabric for an absorbent article,
Producing a first fibrous web comprising a first core-sheath composite fiber;
Producing a second fibrous web comprising a second core-sheath composite fiber and cotton;
Superimposing and integrating the first fiber web and the second fiber web,
A method for producing a nonwoven fabric for absorbent articles, comprising:
The fineness (F1) of the first sheath-core composite fiber is smaller than the fineness (F2) of the second sheath-core composite fiber (F1 <F2),
The difference (F2-F1) between the fineness (F1) of the first sheath-core composite fiber and the fineness (F2) of the second sheath-core composite fiber is 0.1 dtex or more and 1.5 dtex or less,
The sheath component of the first sheath-core composite fiber and the sheath component of the second sheath-core composite fiber include polyethylene,
The heat of fusion ΔH of the sheath component of the first core-sheath type composite fiber is 130 J / g or more;
The heat of fusion ΔH of the sheath component of the second core-sheath type composite fiber is 130 J / g or more.

Furthermore, the present invention provides, as yet another aspect, a method for producing a nonwoven fabric for an absorbent article,
Producing a first fibrous web comprising a first core-sheath composite fiber;
Producing a second fibrous web comprising a second core-sheath composite fiber and cotton;
Superimposing and integrating the first fiber web and the second fiber web,
A method for producing a nonwoven fabric for absorbent articles, comprising:
The fineness (F1) of the first sheath-core composite fiber is smaller than the fineness (F2) of the second sheath-core composite fiber (F1 <F2),
The difference (F2-F1) between the fineness (F1) of the first sheath-core composite fiber and the fineness (F2) of the second sheath-core composite fiber is 0.1 dtex or more and 1.5 dtex or less,
The sheath component of the first sheath-core composite fiber and the sheath component of the second sheath-core composite fiber both include at least one selected from high-density polyethylene and medium-density polyethylene.

In another aspect, the present invention provides a method for producing a nonwoven fabric for an absorbent article,
Producing a first fibrous web comprising a first core-sheath composite fiber;
Producing a second fibrous web comprising a second core-sheath composite fiber and cotton;
Superimposing and integrating the first fiber web and the second fiber web,
A method for producing a nonwoven fabric for absorbent articles, comprising:
The fineness (F1) of the first sheath-core composite fiber is smaller than the fineness (F2) of the second sheath-core composite fiber (F1 <F2),
The ratio (F1 / F2) of the fineness (F1) of the first core-sheath type composite fiber to the fineness (F2) of the second core-sheath type composite fiber is 0.55 or more, and is smaller than 1;
The sheath component of the first sheath-core composite fiber and the sheath component of the second sheath-core composite fiber include polyethylene,
The heat of fusion ΔH of the sheath component of the first core-sheath type composite fiber is 130 J / g or more;
The heat of fusion ΔH of the sheath component of the second core-sheath type composite fiber is 130 J / g or more.

Furthermore, the present invention provides, as yet another aspect, a method for producing a nonwoven fabric for an absorbent article,
Producing a first fibrous web comprising a first core-sheath composite fiber;
Producing a second fibrous web comprising a second core-sheath composite fiber and cotton;
Superimposing and integrating the first fiber web and the second fiber web,
A method for producing a nonwoven fabric for absorbent articles, comprising:
The fineness (F1) of the first sheath-core composite fiber is smaller than the fineness (F2) of the second sheath-core composite fiber (F1 <F2),
The ratio (F1 / F2) of the fineness (F1) of the first core-sheath type composite fiber to the fineness (F2) of the second core-sheath type composite fiber is 0.55 or more, and is smaller than 1;
The sheath component of the first sheath-core composite fiber and the sheath component of the second sheath-core composite fiber both include at least one selected from high-density polyethylene and medium-density polyethylene.

The present invention provides, as a preferred aspect, a nonwoven fabric for an absorbent article,
A nonwoven fabric comprising a first fiber layer and a second fiber layer located on one main surface of the first fiber layer,
The first fiber layer includes a first sheath-core composite fiber,
The second fiber layer includes a second sheath-core composite fiber and cotton,
The fineness (F1) of the first sheath-core composite fiber is smaller than the fineness (F2) of the second sheath-core composite fiber (F1 <F2),
The fineness (F1) of the first core-sheath composite fiber is 1.0 dtex or more and 2.0 dtex or less, and the fineness (F2) of the second core-sheath composite fiber is 1.7 dtex or more and 2.6 dtex or less. Yes,
The sheath component of the first sheath-core composite fiber and the sheath component of the second sheath-core composite fiber include polyethylene,
The heat of fusion ΔH of the sheath component of the first core-sheath type composite fiber is 130 J / g or more;
The heat of fusion ΔH of the sheath component of the second core-sheath type composite fiber is 130 J / g or more.

The present invention provides, as another preferred aspect, a nonwoven fabric for an absorbent article,
A nonwoven fabric comprising a first fiber layer and a second fiber layer located on one main surface of the first fiber layer,
The first fiber layer includes a first sheath-core composite fiber,
The second fiber layer includes a second sheath-core composite fiber and cotton,
The fineness (F1) of the first sheath-core composite fiber is smaller than the fineness (F2) of the second sheath-core composite fiber (F1 <F2),
The fineness (F1) of the first core-sheath composite fiber is 1.0 dtex or more and 2.0 dtex or less, and the fineness (F2) of the second core-sheath composite fiber is 1.7 dtex or more and 2.6 dtex or less. Yes,
The sheath component of the first sheath-core composite fiber and the sheath component of the second sheath-core composite fiber both include at least one selected from high-density polyethylene and medium-density polyethylene.

不織布 The nonwoven fabric for an absorbent article according to the embodiment of the present invention has a good feel and can reduce fluffing and tearing of the nonwoven fabric.

Nonwoven fabric for absorbent articles of one embodiment of the present invention,
A nonwoven fabric comprising a first fiber layer and a second fiber layer located on one main surface of the first fiber layer,
The first fiber layer includes a first sheath-core composite fiber,
The second fiber layer includes a second sheath-core composite fiber and cotton,
The fineness of the first sheath-core composite fiber is smaller than the fineness of the second sheath-core composite fiber,
The difference between the fineness of the first core-sheath type composite fiber and the fineness of the second core-sheath type composite fiber is 0.1 dtex or more and 1.5 dtex or less, and at least one of the following (i) and (ii): Meet.
(I) The sheath component of the first sheath-core composite fiber and the sheath component of the second sheath-core composite fiber include polyethylene, and the heat of fusion ΔH of the sheath component of the first sheath-core composite fiber is 130 J / g. The heat of fusion ΔH of the sheath component of the second core-sheath composite fiber is 130 J / g or more.
(Ii) The sheath component of the first core-sheath composite fiber and the sheath component of the second core-sheath composite fiber both include at least one selected from high-density polyethylene and medium-density polyethylene.

The nonwoven fabric for absorbent articles of a further embodiment of the present invention,
The first fiber layer includes a first sheath-core composite fiber, the second fiber layer includes a second sheath-core composite fiber and cotton, and the fineness of the first sheath-core composite fiber is the second core. The ratio of the fineness of the first core-sheath composite fiber to the fineness of the second core-sheath composite fiber is 0.55 or more, which is smaller than the fineness of the sheath-type composite fiber, and smaller than 1 and the following (i) ) And (ii).
(I) The sheath component of the first sheath-core composite fiber and the sheath component of the second sheath-core composite fiber include polyethylene, and the heat of fusion ΔH of the sheath component of the first sheath-core composite fiber is 130 J / g. The heat of fusion ΔH of the sheath component of the second core-sheath composite fiber is 130 J / g or more.
(Ii) The sheath component of the first core-sheath composite fiber and the sheath component of the second core-sheath composite fiber both include at least one selected from high-density polyethylene and medium-density polyethylene.

The method for producing a nonwoven fabric for an absorbent article according to the embodiment of the present invention includes:
Producing a first fibrous web comprising a first core-sheath composite fiber, producing a second fibrous web comprising a second core-sheath composite fiber and cotton, the first fibrous web and the second fibrous web And a method of producing a nonwoven fabric for an absorbent article, wherein the fineness of the first core-sheath composite fiber is smaller than the fineness of the second core-sheath composite fiber, The difference between the fineness of the first core-sheath composite fiber and the fineness of the second core-sheath composite fiber is 0.1 dtex or more and 1.5 dtex or less, and satisfies at least one of the following (i) and (ii): .
(I) The sheath component of the first sheath-core composite fiber and the sheath component of the second sheath-core composite fiber include polyethylene, and the heat of fusion ΔH of the sheath component of the first sheath-core composite fiber is 130 J / g. The heat of fusion ΔH of the sheath component of the second core-sheath composite fiber is 130 J / g or more.
(Ii) The sheath component of the first core-sheath composite fiber and the sheath component of the second core-sheath composite fiber both include at least one selected from high-density polyethylene and medium-density polyethylene.

A method for producing a nonwoven fabric for an absorbent article according to a further embodiment of the present invention,
Producing a first fibrous web comprising a first core-sheath composite fiber, producing a second fibrous web comprising a second core-sheath composite fiber and cotton, the first fibrous web and the second fibrous web And a method of producing a nonwoven fabric for an absorbent article, wherein the fineness of the first core-sheath composite fiber is smaller than the fineness of the second core-sheath composite fiber, The ratio of the fineness of the first core-sheath composite fiber to the fineness of the second core-sheath composite fiber is 0.55 or more, smaller than 1, and satisfies at least one of the following (i) and (ii): .
(I) The sheath component of the first sheath-core composite fiber and the sheath component of the second sheath-core composite fiber include polyethylene, and the heat of fusion ΔH of the sheath component of the first sheath-core composite fiber is 130 J / g. The heat of fusion ΔH of the sheath component of the second core-sheath composite fiber is 130 J / g or more.
(Ii) The sheath component of the first core-sheath composite fiber and the sheath component of the second core-sheath composite fiber both include at least one selected from high-density polyethylene and medium-density polyethylene.

Nonwoven fabric for absorbent articles of a preferred embodiment of the present invention,
A nonwoven fabric comprising a first fiber layer and a second fiber layer located on one main surface of the first fiber layer,
The first fiber layer includes a first sheath-core composite fiber,
The second fiber layer includes a second sheath-core composite fiber and cotton,
The fineness of the first sheath-core composite fiber is smaller than the fineness of the second sheath-core composite fiber,
The fineness of the first core-sheath composite fiber is 1.0 dtex or more and 2.0 dtex or less, and the fineness of the second core-sheath composite fiber is 1.7 dtex or more and 2.6 dtex or less,
At least one of the following (i) and (ii) is satisfied.
(I) The sheath component of the first sheath-core composite fiber and the sheath component of the second sheath-core composite fiber include polyethylene, and the heat of fusion ΔH of the sheath component of the first sheath-core composite fiber is 130 J / g. The heat of fusion ΔH of the sheath component of the second core-sheath composite fiber is 130 J / g or more.
(Ii) The sheath component of the first core-sheath composite fiber and the sheath component of the second core-sheath composite fiber both include at least one selected from high-density polyethylene and medium-density polyethylene.

不織布 The nonwoven fabric for an absorbent article according to the embodiment of the present invention is a nonwoven fabric including a first fiber layer and a second fiber layer located on one main surface of the first fiber layer. The nonwoven fabric for an absorbent article according to the embodiment of the present invention is a topsheet constituting the absorbent article, wherein the first fiber layer is on the side (outside) opposite to the skin side of the user, and is worn by the user. It can be suitably used as a sheet (also referred to as a back sheet) located on the side.

では In the present invention, the first fiber layer ensures the smoothness of the nonwoven fabric, and the second fiber layer ensures the softness, cushioning property and bulkiness of the nonwoven fabric.

The first fiber layer includes a first sheath-core composite fiber.
The first fiber layer preferably contains the first core-sheath type conjugate fiber in an amount of 50% by mass or more, more preferably 70% by mass or more, with the mass of the first fiber layer being 100% by mass, and more preferably 100% by mass. % Is even more preferred.
When the first fiber layer includes the first core-sheath type composite fiber in an amount of 50% by mass or more, with the mass of the first fiber layer being 100% by mass, an excellent effect of reducing fluffing of the nonwoven fabric and tearing of the nonwoven fabric. To play.
The first fiber layer may include fibers other than the first core-sheath composite fiber. The other fibers may be, for example, synthetic fibers other than the core-sheath type composite fiber.
The first fiber layer may not include cotton.

The second fiber layer includes a second core-sheath composite fiber and cotton.
The second fiber layer contains the second core-sheath type composite fiber in an amount of 70% by mass or more and 99% by mass or less and 1% by mass or more and 30% by mass or less of cotton, with the mass of the second fiber layer being 100% by mass. More preferably, the second core / sheath composite fiber is contained in an amount of 75% by mass or more and 98% by mass or less, and the cotton is more preferably contained in a content of 2% by mass or more and 25% by mass or less. % To 95% by mass, and even more preferably 5 to 15% by mass of cotton.
The second fiber layer contains the second core-sheath type composite fiber in an amount of 70% by mass or more and 99% by mass or less and 1% by mass or more and 30% by mass or less of cotton, with the mass of the second fiber layer being 100% by mass. In this case, the nonwoven fabric has an excellent effect of having a soft touch.
The second fiber layer may include fibers other than the second core-sheath composite fiber and cotton. The other fibers may be, for example, synthetic fibers other than the core-sheath type composite fiber.

The cotton contained in the second fiber layer is not particularly limited as long as the nonwoven fabric targeted by the present invention can be obtained. As the cotton, for example, upland cotton, barbadense cotton, desi cotton and the like can be exemplified.
The fineness of the cotton is not particularly limited, and may be, for example, 0.6 dtex or more and 5.6 dtex or less, particularly 1.4 dtex or more and 4.4 dtex or less, and more particularly 1.7 dtex or more and 3.3 dtex or less. When the fineness of the cotton is in this range, the nep does not become too large, and a smooth feel can be obtained. In addition, the fineness of cotton can be calculated according to a method using JIS L 1019 7.4.1 micronail (the same applies to the following).
The fiber length of the cotton is not particularly limited, and may be appropriately selected according to the method of producing the nonwoven fabric. When a card web is produced to produce a nonwoven fabric, the average fiber length of the cotton may be, for example, 15 mm or more and 100 mm or less, particularly 20 mm or more and 70 mm or less. Plant-derived natural fibers such as cotton are generally supplied in a form in which the fiber length is not constant, but such forms may be used in the present embodiment.

The second fiber layer preferably contains the cotton in a ratio of 1% by mass or more and 30% by mass or less, based on the total mass of the second fiber layer, and more preferably contains 2% by mass or more and 25% by mass or less. More preferably, the content is 5% by mass or more and 15% by mass or less.
When the second fiber layer contains the cotton at a ratio of 1% by mass or more and 30% by mass or less based on the total mass of the second fiber layer, the nonwoven fabric has an excellent effect of having a soft touch.

The fineness (F1) of the first core-sheath composite fiber is smaller than the fineness (F2) of the second sheath-core composite fiber (F1 <F2).
The fineness (F1) of the first core-sheath composite fiber is 1.0 dtex or more and 2.9 dtex or less on the assumption that the fineness (F2) of the second core-sheath composite fiber is smaller (F1 <F2). It is preferably from 1.0 dtex to 2.4 dtex, more preferably from 1.0 dtex to 2.0 dtex, even more preferably from 1.2 dtex to 1.9 dtex. It is even more preferred that the number be 4 dtex or more and 1.8 dtex or less.
The fineness (F2) of the second core-sheath type composite fiber is 1.7 dtex or more and 4.4 dtex or less on the assumption that the fineness (F1) of the first core-sheath type composite fiber is larger (F1 <F2). It is preferably 1.7 dtex or more and 3.5 dtex or less, preferably 1.7 dtex or more and 2.6 dtex or less, more preferably 1.8 dtex or more and 2.5 dtex or less, and 1.9 dtex. It is even more preferable that the number be 2.4 dtex or less.

において In the present specification, in the case where the first core-sheath conjugate fiber is a cotton blend containing two or more kinds of core-sheath conjugate fibers, the fineness means a mass average value. In the case where the second core-sheath type composite fiber is a cotton blend containing two or more kinds of core-sheath type composite fibers, the fineness similarly means a mass average value. Further, when the first core-sheath type composite fiber is a cotton blend containing two or more kinds of core-sheath type composite fibers, it is preferable that each fineness is included in the above numerical range, and the second core-sheath type composite fiber is In the case of a cotton blend containing two or more kinds of core-sheath type composite fibers, it is preferable that each fineness is included in the above numerical range.

Further, the ratio of the fineness (F1) of the first sheath-core composite fiber to the fineness (F2) of the second sheath-core composite fiber (the fineness of the first sheath-core composite fiber / the fineness of the second sheath-core composite fiber) ) (F1 / F2) is smaller than 1 and preferably 0.95 or less, more preferably 0.38 or more and 0.93 or less, and more preferably 0.40 or more and 0.93 or less. More preferably, it is 0.55 or more and 0.92 or less, and even more preferably 0.70 or more and 0.90 or less. When the ratio (F1 / F2) between the fineness of the first core-sheath type composite fiber and the fineness of the second core-sheath type composite fiber is smaller than 1 and 0.55 or more, the fibers constituting the second fiber layer And the number of places where the fibers constituting the first fiber layer adhere to the fibers constituting the second fiber layer does not decrease, thereby providing an advantageous effect that the nonwoven fabric is less likely to fluff or break. The nonwoven fabric has a soft and smooth touch when it is not less than 0.55 and not more than 0.92.
Assuming that the fineness of the first core-sheath composite fiber is smaller than the fineness of the second core-sheath composite fiber, the fineness of the first core-sheath composite fiber is 1.0 dtex or more and 2.9 dtex or less. It is preferable that the fineness of the second core-sheath composite fiber is 1.7 dtex or more and 4.4 dtex or less, and the nonwoven fabric can have a soft and smooth tactile sensation. When the fineness of the fiber is 1.0 dtex or more and 2.0 dtex or less, and the fineness of the second core-sheath composite fiber is 1.7 dtex or more and 2.6 dtex or less, the nonwoven fabric has a soft and smooth touch. Has the effect.

Assuming that the fineness of the first sheath-core composite fiber is smaller than the fineness of the second sheath-core composite fiber, the fineness of the first sheath-core composite fiber and the fineness of the second sheath-core composite fiber (The fineness of the second core-sheath type composite fiber−the fineness of the first core-sheath type composite fiber) is preferably 0.1 dtex or more and 1.5 dtex or less, and is 0.2 dtex or more and 1.2 dtex or less. It is more preferably 0.3 dtex or more and 1.0 dtex or less. When the difference between the fineness of the first core-sheath type composite fiber and the fineness of the second core-sheath type composite fiber is 0.1 dtex or more and 1.5 dtex or less, the number of fibers constituting the second fiber layer is small. In addition, since the number of places where the fibers constituting the first fiber layer adhere to the fibers constituting the second fiber layer does not decrease, the advantageous effect that the nonwoven fabric is less likely to be fluffed or torn can be obtained. .

The basis weight of the first fiber layer is preferably smaller than the basis weight of the second fiber layer. When the basis weight of the first fiber layer is smaller than the basis weight of the second fiber layer, the nonwoven fabric has an excellent effect of having a soft touch.
The basis weight of the first fiber layer, 5 g / preferably ^m is ² or more 20 g / ^{m 2} or less, more preferably 7 g / ^{m 2} or more 18 g / ^{m 2} or less, 8 g / ^{m 2} or more 15 g / m ^Even more preferably, it is ² or less.
The basis weight of the second fiber layer, 7 g / preferably ^m is ² or more 25 g / ^{m 2} or less, more preferably 9 g / ^{m 2} or more 23 g / ^{m 2} or less, 10 g / ^{m 2} or more 20 g / m ^Even more preferably, it is ² or less.

The ratio of the basis weight of the first fiber layer to the basis weight of the second fiber layer (the basis weight of the first fiber layer / the basis weight of the second fiber layer) is smaller than 1, preferably 0.95 or less, and 0.20 or less. It is more preferably not less than 0.90 and not more than 0.40, and still more preferably not less than 0.45 and not more than 0.80.
When the basis weight of the first fiber layer is 5 g / m ² or more and 20 g / m ² or less, and the basis weight of the second fiber layer is 7 g / m ² or more and 25 g / m ² or less, the nonwoven fabric has a soft touch. It has an excellent effect of having.

The first core-sheath conjugate fiber is a so-called concentric core-sheath conjugate fiber (also referred to as a concentric core-sheath conjugate fiber) in which two different resin components constituting the conjugate fiber are concentrically arranged. A so-called eccentric core-sheath type conjugate fiber in which the center of gravity of the core component in the fiber cross section is different from the center of gravity of the entire conjugate fiber may be used. More preferably, it is a concentric core-sheath type composite fiber. It is presumed that the concentric core-sheath type composite fiber has more intersection points between the fibers than the eccentric core-sheath type composite fiber, and thus it is easy to suppress fluffing and tearing of the nonwoven fabric.

The first core-sheath conjugate fiber preferably contains 50% by mass or more, more preferably 70% by mass or more, of the concentric core-sheath conjugate fiber. Particularly preferred are conjugate fibers. When the first core-sheath type conjugate fiber contains 50% by mass or more of the concentric core-sheath type conjugate fiber, the thickness of the nonwoven fabric can be suppressed, and the nonwoven fabric has an excellent effect of having a smooth touch.

The core component of the first core-sheath type conjugate fiber is not particularly limited as long as the nonwoven fabric targeted by the present invention can be obtained. However, polyethylene terephthalate, polytrimethylene terephthalate, polybutylene terephthalate, polyethylene naphthalate Polyester resins such as polylactic acid, polyolefin resins such as polypropylene and polymethylpentene, polyamide resins such as nylon 66, nylon 12, and nylon 6, acrylic resins, and polycarbonate, polyacetal, polystyrene, and cyclic polyolefin. It is preferable to contain at least one resin selected from engineering plastics in an amount of 50% by mass or more, more preferably 50% by mass or more of a polyester resin, and 50% by mass of polyethylene terephthalate. Even more preferably comprise more. When the core component of the first core-sheath composite fiber contains at least 50% by mass of at least one resin selected from a polyester resin and a polyolefin resin, the card processability of the first core-sheath composite fiber is reduced. It has an excellent effect of being good. The core component may contain other components such as other resins and various additives usually added to the resin constituting the core component, as long as the nonwoven fabric targeted by the present invention can be obtained.

The sheath component of the first core-sheath type composite fiber contains polyethylene.
The polyethylene contained in the sheath component is not particularly limited as long as the nonwoven fabric aimed at by the present invention can be obtained. Examples thereof include polyethylene, medium-density polyethylene, low-density polyethylene, and linear low-density polyethylene, and it is preferably at least one selected from high-density polyethylene and medium-density polyethylene. When the polyethylene is at least one selected from high-density polyethylene and medium-density polyethylene, the first core-sheath type conjugate fiber has an excellent effect in that the card processability is good. In addition, when the polyethylene is at least one selected from high-density polyethylene and medium-density polyethylene, an excellent effect that fluff and tear of the nonwoven fabric can be reduced can be achieved. High-density polyethylene and medium-density polyethylene are assumed to be able to reduce the fluff and tear of the non-woven fabric because the resin is harder than the low-density polyethylene and linear low-density polyethylene, so that the adhesive force between the fibers increases. Is done. The sheath component may contain other components such as other resins and various additives usually added to polyethylene as long as the sheath component is 100% by mass and the polyethylene is 50% by mass or more. The sheath component may contain polyethylene by 70% by mass or more, 80% by mass or more, 90% by mass or more, or 95% by mass or more, with the whole sheath component being 100% by mass. The sheath component may be substantially polyethylene.

Preferably, the heat of fusion ΔH of the sheath component of the first core-sheath composite fiber is 130 J / g or more, and the heat of fusion ΔH of the sheath component of the second core-sheath composite fiber is 130 J / g or more.
The heat of fusion ΔH of the sheath component of the first core-sheath composite fiber is 140 J / g or more and 270 J / g or less, and the heat of fusion ΔH of the sheath component of the second core-sheath composite fiber is 140 J / g or more and 270 J / g. The following is more preferable.
The heat of fusion ΔH of the sheath component of the first core-sheath composite fiber is 150 J / g or more and 220 J / g or less, and the heat of fusion ΔH of the sheath component of the second core-sheath composite fiber is 150 J / g or more and 220 J / g. It is even more preferred that:
When the heat of fusion ΔH of the sheath component of the first core-sheath composite fiber is 130 J / g or more and the heat of fusion ΔH of the sheath component of the second core-sheath composite fiber is 130 J / g or more, the nonwoven fabric is fluffed. And an excellent effect that tearing of the nonwoven fabric is suppressed. It is presumed that the sheath component, which requires a large amount of energy for melting, has a high adhesive strength, so that fluffing of the nonwoven fabric and tearing of the nonwoven fabric can be suppressed.
The heat of fusion ΔH of the sheath component of the conjugate fiber can be measured and obtained by the method described in Examples.
The difference between the heat of fusion ΔH of the sheath component of the first core-sheath composite fiber and the heat of fusion ΔH of the sheath component of the second sheath-core composite fiber is preferably 80 J / g or less in absolute value, and 50 J / g or less. Is more preferable, and it is more preferable that it is 30 J / g or less.

The melt flow rate of the sheath component of the first core-sheath composite fiber is preferably 15 g / 10 min or more, more preferably 16 g / 10 min or more and 30 g / 10 min or less, and 18 g / 10 min or more and 25 g. It is even more preferable that the time is / 10 minutes or less.
When the melt flow rate of the sheath component of the first core-sheath type composite fiber is 15 g / 10 minutes or more, an excellent effect of suppressing fluffing of the nonwoven fabric and tearing of the nonwoven fabric is exhibited.
The melt flow rate is measured by the method described in the examples.

The core / sheath ratio (core / shell component mass ratio) of the core / sheath component of the first core / sheath type composite fiber is preferably 20/80 to 80/20, and 30/70 to 70/70. The ratio is more preferably 30, more preferably 40/60 to 60/40, and particularly preferably 40/60 to 55/45.
When the core / sheath ratio (core component / sheath component mass ratio) between the core component and the sheath component of the first core / sheath conjugate fiber is 20/80 to 80/20, An excellent effect that both the card processability and the suppression of fluffing of the nonwoven fabric can be achieved is achieved.

The average fiber length of the first core-sheath type composite fiber is preferably 20 mm or more and 110 mm or less, more preferably 30 mm or more and 70 mm or less, and even more preferably 35 mm or more and 55 mm or less.
When the average fiber length of the first core-in-sheath type conjugate fiber is 20 mm or more and 110 mm or less, an excellent effect that the card processability of the first core-in-sheath type conjugate fiber is good is exhibited.

The second core-sheath composite fiber is a so-called concentric core-sheath composite fiber (also referred to as a concentric core-sheath composite fiber) in which two different resin components constituting the composite fiber are concentrically arranged. A so-called eccentric core-sheath type conjugate fiber in which the center of gravity of the core component in the fiber cross section is different from the center of gravity of the entire conjugate fiber may be used. More preferably, it is a concentric core-sheath type composite fiber. It is presumed that the concentric core-sheath type composite fiber has more intersections between the fibers than the eccentric core-sheath type composite fiber, so that the number of bonding points with the fibers constituting the first fiber layer increases, so that it is easy to suppress fluffing and tearing of the nonwoven fabric. You.

The second core-sheath conjugate fiber preferably contains 50% by mass or more, more preferably 70% by mass or more, of the concentric core-sheath conjugate fiber. Particularly preferred are conjugate fibers. When the second core-sheath type conjugate fiber contains 50% by mass or more of the concentric core-sheath type conjugate fiber, the thickness of the nonwoven fabric can be suppressed, and the nonwoven fabric has an excellent effect of having a smooth touch.

The core component of the second core-sheath type conjugate fiber is not particularly limited as long as the nonwoven fabric aimed at by the present invention can be obtained. Polyester resins such as polylactic acid, polyolefin resins such as polypropylene and polymethylpentene, polyamide resins such as nylon 66, nylon 12, and nylon 6, acrylic resins, and polycarbonate, polyacetal, polystyrene, and cyclic polyolefin. The resin preferably contains at least one resin selected from engineering plastics in an amount of 50% by mass or more, more preferably contains a polyester-based resin in an amount of 50% by mass or more, and contains polyethylene terephthalate in an amount of 50% by mass. It is even more preferred, including percent. When the core component of the second core-sheath composite fiber contains at least 50% by mass of at least one resin selected from a polyester resin and a polyolefin resin, the card processability of the second core-sheath composite fiber is reduced. It has an excellent effect of being good.

The second core-sheath type composite fiber has a sheath component containing polyethylene.
The polyethylene contained in the sheath component is not particularly limited as long as the nonwoven fabric aimed at by the present invention can be obtained. Examples thereof include polyethylene resin, medium-density polyethylene, low-density polyethylene, linear low-density polyethylene, and the like, and it is preferably at least one selected from high-density polyethylene and medium-density polyethylene. When the polyethylene is at least one selected from high-density polyethylene and medium-density polyethylene, an excellent effect is obtained in that the cardability of the second core-sheath composite fiber is good. Further, when the polyethylene is at least one selected from high-density polyethylene and medium-density polyethylene, as in the description of the first core-in-sheath type conjugate fiber, it is possible to reduce fluffing and tearing of the nonwoven fabric. It works. The sheath component may contain other components such as other resins and various additives usually added to polyethylene as long as the sheath component is 100% by mass and the polyethylene is 50% by mass or more. The sheath component may contain polyethylene by 70% by mass or more, 80% by mass or more, 90% by mass or more, or 95% by mass or more, with the whole sheath component being 100% by mass. The sheath component may be substantially polyethylene.

The melt flow rate of the sheath component of the second core-sheath type composite fiber is preferably 10 g / 10 min or more, more preferably 15 g / 10 min or more and 30 g / 10 min or less, and 17 g / 10 min or more and 25 g. It is even more preferable that the time is / 10 minutes or less.
When the melt flow rate of the sheath component of the second core-sheath composite fiber is 10 g / 10 minutes or more, an excellent effect of suppressing fluffing of the nonwoven fabric and tearing of the nonwoven fabric can be achieved.
The melt flow rate is measured by the method described in the examples.

In the second core-sheath type composite fiber, the core-to-sheath ratio (core component / sheath component 比 mass ratio) between the core component and the sheath component is preferably 20/80 to 80/20, and 30/70 to 70/30. Is more preferable, and even more preferably 40/60 to 60/40. When the core-sheath ratio (core component / sheath component 成分 mass ratio) of the core component and the sheath component is 20/80 to 80/20, the card processability of the second core-sheath type composite fiber and the suppression of fluffing of the nonwoven fabric are improved. An excellent effect that both can be achieved is exhibited.

The average fiber length of the second core-sheath type composite fiber is preferably 20 mm or more and 110 mm or less, more preferably 30 mm or more and 70 mm or less, and even more preferably 35 mm or more and 55 mm or less.
When the average fiber length of the second core-sheath type composite fiber is 20 mm or more and 110 mm or less, an excellent effect that the card processability of the second core-sheath type composite fiber is good is exhibited.

The combination of the resin contained in the core component and the resin contained in the sheath component of the first core-sheath type composite fiber and the second core-sheath type composite fiber may be the same or different.

第 The first fiber layer and the second fiber layer used in the present invention can be manufactured by using various methods for manufacturing a fiber web. The production method is not particularly limited as long as the nonwoven fabric for an absorbent article intended by the present invention can be obtained. As such a production method, for example, a card method such as a parallel web, a cross web, a Chris cross web, a semi-random web and a random web, an air lay method, and the like can be exemplified. Since the back sheet for an absorbent article is required to have flexibility and an appropriate porosity in which some gaps exist between fibers, the fiber web is preferably a card web. The first fiber layer and the second fiber layer may be different types of fibrous webs.

The present invention provides a method for producing a nonwoven fabric for an absorbent article of the embodiment of the present disclosure,
Producing a first fibrous web comprising a first core-sheath composite fiber;
Producing a second fibrous web comprising a second core-sheath composite fiber and cotton;
Superimposing and integrating the first fiber web and the second fiber web,
including.

不織布 The nonwoven fabric for an absorbent article according to the embodiment of the present invention can be manufactured by laminating and integrating a first fiber web serving as a first fiber layer and a second fiber web serving as a second fiber layer. The production method is not particularly limited as long as the nonwoven fabric for an absorbent article intended by the present invention can be obtained. Therefore, in order to integrate the first fiber web and the second fiber web, the first fiber web and the second fiber web are overlapped and entangled, for example, a needle punching process or a water entanglement process is performed so that the two fiber webs are entangled. An integrated nonwoven fabric may be used, but it is preferable that the first fibrous web and the second fibrous web are overlapped and bonded to form an integrated nonwoven fabric. For example, it is more preferable to produce a heat-bonded nonwoven fabric in which the first fiber web and the second fiber web are bonded by a thermal bonding method in which heat treatment is performed (also referred to as a thermal bond nonwoven fabric in some documents). This is because the heat-bonded non-woven fabric has remarkable effects such as flexibility in the thickness direction, bulk recovery, and smooth texture of the non-woven fabric surface.

The method of heat treatment, that is, the method of thermal bonding can be performed by a known method, for example, an air through method (hot air penetration heat treatment method), a hot air blowing heat treatment method, a heat roll method, an infrared heat treatment method, and the like. A heat treatment machine in which pressure such as wind pressure is not applied much to the fiber web is preferably used, and an air-through method (hot air penetration heat treatment method) is more preferable. The heat treatment conditions such as the heat treatment temperature are selected and performed, for example, such that the sheath component is sufficiently melted and / or softened and the fibers are joined at the contact points or intersections. For example, the heat treatment temperature is equal to or higher than Tm (Tm + 50 ° C.) when the melting point of the thermoplastic resin having the lowest melting point among the thermoplastic resins constituting the synthetic fibers contained in the first fiber web and the second fiber web is Tm (° C.). The heat treatment is preferably performed in the range of (° C) or less, more preferably in the range of (Tm + 3 ° C) or more and (Tm + 40 ° C) or less, and performed in the range of (Tm + 5 ° C) or more and (Tm + 30 ° C) or less. Is particularly preferred.

The hot air penetration type heat treatment method is not particularly limited, and can be performed by a known method.When manufacturing the nonwoven fabric, that is, when performing the heat treatment, a laminated web in which the first fiber web and the second fiber web are overlapped with each other, It is preferable that the first fibrous web is placed so as to be in contact with a transport support (for example, a conveyor belt) of a heat treatment machine, and is heat-treated by blowing hot air at a predetermined temperature from the second fibrous web. In the hot air penetrating heat treatment, the first fiber web serving as the first fiber layer is in contact with the supporting carrier during the heat treatment, and hot air is blown from the second fiber web side serving as the second fiber layer, The first fibrous web is pressed against the support during the heat treatment, resulting in a smoother surface. Therefore, a smoother feel is imparted to the surface of the nonwoven fabric. In addition, the nonwoven fabric for absorbent articles of the embodiment of the present invention may further have, if necessary, an additional layer usually included in the nonwoven fabric.

Therefore, in the nonwoven fabric for an absorbent article of the embodiment of the present invention, the fibers of the first fiber layer and the second fiber layer may be entangled and integrated, but the fibers are bonded and integrated. It is more preferable that the fibers are integrated by thermal bonding. In particular, it is preferable that the first fiber layer and the second fiber layer are bonded and integrated by the sheath component of the first core-sheath composite fiber and the sheath component of the second core-sheath composite fiber. In the first fiber layer, the fibers are preferably bonded to each other by a sheath component of a first core-sheath composite fiber, and the second fiber layer is bonded to each other by a sheath component of a second core-sheath composite fiber. Is preferred.

不織布 The nonwoven fabric for an absorbent article according to the embodiment of the present invention may be subjected to additional processing such as embossing, if necessary, and may have such additional forms and shapes.

The basis weight of the nonwoven fabric for an absorbent article according to the embodiment of the present invention is not particularly limited as long as the nonwoven fabric aimed at by the present invention can be obtained, but it is 12 g / m ² or more and 45 g / m ² or less. Is preferably 16 g / m ² or more and 41 g / m ² or less, and more preferably 18 g / m ² or more and 35 g / m ² or less.
When the basis weight of the nonwoven fabric is 12 g / m ² or more and 45 g / m ² or less, an excellent effect that the thickness of the nonwoven fabric is in an appropriate range is exhibited.

The thickness of the nonwoven fabric for an absorbent article according to the embodiment of the present invention is not particularly limited as long as the nonwoven fabric targeted by the present invention can be obtained, but may be 0.20 mm or more and 3.0 mm or less. More preferably, it is 0.30 mm or more and 1.5 mm or less, and even more preferably 0.40 mm or more and 1.0 mm or less.
When the thickness of the nonwoven fabric is 0.20 mm or more and 3.0 mm or less, the nonwoven fabric has an excellent effect of having a soft touch.

The specific volume of the nonwoven fabric for an absorbent article according to the embodiment of the present invention is not particularly limited as long as the nonwoven fabric aimed at by the present invention can be obtained, but is 5 cm ³ / g or more and 150 cm ³ / g or less. It is more preferably 7 cm ³ / g or more and 130 cm ³ / g or less, and still more preferably 10 cm ³ / g or more and 100 cm ³ / g or less.
When the specific volume of the nonwoven fabric is 5 cm ³ / g or more and 150 cm ³ / g or less, the nonwoven fabric has an excellent effect of having a soft touch.

The tensile strength (MD) of the nonwoven fabric for an absorbent article according to the embodiment of the present invention is not particularly limited as long as the nonwoven fabric targeted by the present invention can be obtained. For example, the tensile strength is 5 N / 5 cm or more and 60 N / 5 cm. Or less, preferably 5 N / 5 cm or more and 50 N / 5 cm or less, more preferably 10 N / 5 cm or more and 45 N / 5 cm or less, and even more preferably 20 N / 5 cm or more and 40 N / 5 cm or less.
When the tensile strength (MD) of the nonwoven fabric is 5 N / 5 cm or more and 60 N / 5 cm or less, there is an excellent effect that the workability of the nonwoven fabric in producing an absorbent article is good.

The tensile strength (CD) of the nonwoven fabric for an absorbent article according to the embodiment of the present invention is not particularly limited as long as the nonwoven fabric aimed at by the present invention can be obtained, but is not less than 1 N / 5 cm and not more than 17 N / 5 cm. Is preferable, and it is more preferable that it is 2 N / 5 cm or more and 15 N / 5 cm or less, and it is even more preferable that it is 3 N / 5 cm or more and 12 N / 5 cm or less.
When the tensile strength (CD) of the nonwoven fabric is 1 N / 5 cm or more and 15 N / 5 cm or less, there is an excellent effect that the nonwoven fabric has good workability when producing an absorbent article.

The elongation (MD) of the nonwoven fabric for an absorbent article according to the embodiment of the present invention is not particularly limited as long as the nonwoven fabric aimed at by the present invention can be obtained, but is 10% or more and 70% or less. Is preferably 15% or more and 60% or less, and more preferably 20% or more and 50% or less.
When the elongation (MD) of the nonwoven fabric is 10% or more and 70% or less, an excellent effect that the workability of the nonwoven fabric at the time of manufacturing an absorbent article is good is exhibited.

The elongation (CD) of the nonwoven fabric for an absorbent article according to the embodiment of the present invention is not particularly limited as long as the nonwoven fabric aimed at by the present invention can be obtained. Is preferably 60% or more and 140% or less, and more preferably 70% or more and 130% or less.
When the elongation (CD) of the nonwoven fabric is 50% or more and 150% or less, there is an excellent effect that workability of the nonwoven fabric at the time of manufacturing an absorbent article is good.

The stress at 10% elongation (MD) of the nonwoven fabric for an absorbent article according to the embodiment of the present invention is not particularly limited as long as the nonwoven fabric aimed at by the present invention can be obtained, but is, for example, 2N / 5cm to 25N. / 5 cm or less, preferably 3 N / 5 cm or more and 25 N / 5 cm or less, more preferably 5 N / 5 cm or more and 20 N / 5 cm or less, and more preferably 6 N / 5 cm or more and 15 N / 5 cm or less. Even more preferred.
When the 10% elongation stress (MD) of the nonwoven fabric is 2 N / 5 cm or more and 25 N / 5 cm or less, an excellent effect that the workability of the nonwoven fabric at the time of manufacturing an absorbent article is good is exhibited.

The stiffness (MD direction) of the nonwoven fabric of the embodiment of the present invention is preferably 40 cN or less, more preferably 30 cN or less, still more preferably 10.0 cN or less, and more preferably 7 cN or less. Is even more preferably 5 cN or less.
When the rigidity (MD direction) of the nonwoven fabric is 40 cN or less, the nonwoven fabric has an excellent effect of having a soft touch.

The stiffness (CD direction) of the nonwoven fabric of the embodiment of the present invention is preferably 70 cN or less, more preferably 60 cN or less, still more preferably 20.0 cN or less, and more preferably 15 cN or less. Is still more preferred, and particularly preferably 12 cN or less.
When the rigidity (CD direction) of the nonwoven fabric is 70 cN or less, the nonwoven fabric has an excellent effect of having a soft touch.

The stiffness (nonwoven fabric) of the nonwoven fabric of the embodiment of the present invention is preferably 110 cN or less, more preferably 90 cN or less, still more preferably 16.0 cN or less, and more preferably 15.0 cN or less. It is even more preferred that it is less than or equal to 14.0 cN, even more preferably 13.0 cN or less.
When the rigidity of the nonwoven fabric (the entire nonwoven fabric) is 110 cN or less, the nonwoven fabric has an excellent effect of having a soft touch.

不織布 The nonwoven fabric of the embodiment of the present invention preferably has a fuzz of 30 or less, more preferably 20 or less, and even more preferably 15 or less.

不織布 The nonwoven fabric for an absorbent article according to the embodiment of the present invention can be used for various absorbent articles such as disposable diapers, sanitary napkins, incontinence pads and panty liners. Since the nonwoven fabric for an absorbent article of the present invention is excellent in tactile sensation, it can be used for any member as long as it is various absorbent articles. The nonwoven fabric for an absorbent article of the present invention can also be used as a top sheet, side gathers, a back sheet, or a sheet of a waist portion in a pants-type disposable diaper.

In consideration of the feel and low fuzziness of the nonwoven fabric, the nonwoven fabric for an absorbent article according to the embodiment of the present invention is preferably used as a backsheet.
Accordingly, the present invention provides a backsheet for an absorbent article, including the nonwoven fabric for an absorbent article of the embodiment of the present invention.

Further, the present invention can provide various absorbent articles including such a nonwoven fabric for absorbent articles.
It is preferable that the absorbent article according to the embodiment of the present invention includes a backsheet for an absorbent article, and the first fiber layer of the backsheet for the absorbent article be disposed on a side close to clothing of a user.
Therefore, the present invention provides an absorbent article in which the first fiber layer of the backsheet for an absorbent article is disposed on the side close to the clothes of the user, and includes the backsheet for the absorbent article.

では In the absorbent article according to the embodiment of the present invention, it is preferable that the nonwoven fabric for the absorbent article has the first fiber layer disposed on the clothing side. As described above, in the present invention, the first fiber layer secures the smoothness of the nonwoven fabric, and the second fiber layer secures the softness, cushioning property, and bulkiness of the nonwoven fabric. The side directly touched by a consumer holding an absorbent article such as a diaper is the clothes side. When the clothing side has a smooth touch, the consumer can comfortably use the absorbent article (for example, can change diapers), and can exert excellent effects.

Hereinafter, the present invention will be described specifically and in detail with reference to examples and comparative examples. However, these examples are only one embodiment of the present invention, and the present invention is not limited to these examples.

The fibers used in Examples and Comparative Examples and methods for measuring their physical properties are shown.
<Fibers used in Examples and Comparative Examples>
Fiber A: polyethylene terephthalate (melting point: 260 ° C.) as a core, high-density polyethylene (melting point: 132 ° C., MFR: 20 g / 10 min) as a sheath, and a composite ratio (core / sheath, mass ratio) of 50 / Concentric core-sheath type conjugate fiber having a fineness of 1.7 dtex (fiber diameter 13.8 μm) and a fiber length of 45 mm, which is 50 (trade name NBF (SH) manufactured by Daiwabo Polytech Co., Ltd.)
Fiber B: polyethylene terephthalate (melting point: 260 ° C.) as a core, high-density polyethylene (melting point: 132 ° C., MFR: 19 g / 10 min) as a sheath, and a composite ratio (core / sheath, mass ratio) of 50 / Concentric core-sheath type composite fiber having a fineness of 2.2 dtex (fiber diameter 15.7 μm) and a fiber length of 44 mm (NBF (SH) manufactured by Daiwabo Polytech Co., Ltd.) of 50
Fiber C: polyethylene terephthalate (melting point: 260 ° C.) as a core, high-density polyethylene (melting point: 132 ° C., MFR: 12 g / 10 min) as a sheath, and a composite ratio (core / sheath, mass ratio) of 50 / Concentric core-sheath type conjugate fiber having a fineness of 2.0 dtex (fiber diameter 15.0 μm) and a fiber length of 45 mm (trade name: NBF (SH) manufactured by Daiwabo Polytech Co., Ltd.) having a fiber size of 50
Fiber D: polyethylene terephthalate (melting point: 260 ° C.) as the core, linear low density polyethylene (melting point: 120 ° C., MFR: 20 g / 10 min) as the sheath, composite ratio (core / sheath, mass ratio) Is 60/40, a concentric core-sheath composite fiber having a fineness of 2.0 dtex (fiber diameter 14.6 μm) and a fiber length of 45 mm (trade name NBF (SL) manufactured by Daiwabo Polytech Co., Ltd.)
Fiber E: polyethylene terephthalate (melting point: 260 ° C.) as the core, high-density polyethylene (melting point: 132 ° C., MFR: 20 g / 10 min) as the sheath, composite ratio (core / sheath, mass ratio 55/45) Eccentric core-sheath type composite fiber with a fineness of 3.3 dtex (fiber diameter 18.8 μm), a fiber length of 51 mm and an eccentricity of 25% (trade name NBF (SH) V manufactured by Daiwabo Polytech Co., Ltd.)
Fiber F: Cotton having an average fiber length of 35 mm (fiber length 10 to 60 mm) and an average fineness of 2.5 dtex (trade name MSD manufactured by Marusan Sangyo Co., Ltd.)
Fiber G: polyethylene terephthalate (melting point: 260 ° C.) as a core, high-density polyethylene (melting point: 132 ° C., MFR: 12 g / 10 min) as a sheath, and a composite ratio (core / sheath, mass ratio) of 50 / Concentric core-sheath composite fiber (fineness: 3.3 dtex (fiber diameter: 19.2 μm), fiber length: 51 mm, trade name: NBF (SH) manufactured by Daiwabo Polytech Co., Ltd.)
Fiber H: polyethylene terephthalate (melting point: 260 ° C.) as a core, medium density polyethylene (melting point: 125 ° C., MFR: 19 g / 10 min) as a sheath, and a composite ratio (core / sheath, mass ratio) of 50 / Concentric core-sheath composite fiber with a fineness of 2.3 dtex (fiber diameter 16.0 μm) and a fiber length of 45 mm, which is 50

<Measurement of melt flow rate (MFR)>
The polyethylene resin constituting the sheath component of the core-sheath type composite fiber was measured under the conditions of a measurement temperature of 190 ° C. and a load of 21.18 N based on JIS K7210-1.

<Measurement of heat of fusion ΔH of sheath component>
Differential scanning calorimetry (DSC) was performed on the sheath components of the first sheath-core composite fiber and the second sheath-core composite fiber used in Examples and Comparative Examples based on JIS K 7122 (1987), and the heat of fusion was measured. ΔH was determined. DSC was measured using a differential scanning calorimeter (trade name “EXSTAR6000 / DSC6200” manufactured by Seiko Instruments Inc.). The sample amount of the fiber was 3.0 mg, the temperature was raised from room temperature to 300 ° C. at a rate of 10 ° C./min to melt the fiber, and then the temperature was lowered to 20 ° C. at a rate of 10 ° C./min. Then, the temperature was increased again at a temperature increasing speed of 10 ° C./min. The heat of fusion ΔH of the sheath component was determined from the melting peak when the temperature was raised again. If the melting peak is reached when the temperature is raised again, it is considered that the temperature is close to the heat of fusion of the sheath component after the thermal bonding during the production of the nonwoven fabric. In this specification, the heat of fusion ΔH of the sheath component refers to the heat of fusion ΔH per mass of the sheath component.

Regarding the fibers A to H, the heat of fusion ΔH of the sheath component measured by the method described above was as follows.
Fiber A: 176.4 J / g
Fiber B: 175.6 J / g
Fiber C: 186.0 J / g
Fiber D: 98.8 J / g
Fiber E: 178.3 J / g
Fiber G: 171.6 J / g
Fiber H: 133.8 J / g

(Production of the nonwoven fabric of Example 1)
Using a fiber A as the first core-sheath composite fiber, a first fiber web to be a first fiber layer was produced using a parallel card machine. The target basis weight of the first fiber web was 10 g / m ² .
Using fiber B as the second core-sheath composite fiber, 91% by mass of fiber B and 9% by mass of fiber F are mixed, and the second fiber web to be the second fiber layer is formed by using a parallel card machine. Was prepared. The target basis weight of the second fiber web was 15 g / m ² .
The obtained first fiber web and second fiber web are superimposed to produce a laminated fiber web, and the laminated fiber web is heat-treated for 12 seconds by a hot air penetration heat treatment machine set at a temperature of 135 ° C. The fibers are adhered to each other by a polyethylene resin component of the first core-sheath type conjugate fiber and the second core-sheath type conjugate fiber contained in each of the first fiber web and the second fiber web, so that the first fiber layer and the second fiber layer are separated from each other. Was obtained. In addition, since the weight of the actually manufactured nonwoven fabric is not always as intended and has an error, the weight of the actually obtained nonwoven fabric is described in Table 1 for some examples and comparative examples. are doing.

(Production of the nonwoven fabric of Example 2)
A nonwoven fabric of Example 2 was obtained using the same method as that described in Example 1 except that the fiber C was used as the second core-sheath type composite fiber.

(Production of the nonwoven fabric of Comparative Example 1)
A nonwoven fabric of Comparative Example 1 was obtained using the same method as that described in Example 1 except that the fiber D was used as the second core-sheath type composite fiber.

(Production of the nonwoven fabric of Comparative Example 2)
In Example 2, a nonwoven fabric of Comparative Example 2 was obtained using 50% by mass of fiber C and 50% by mass of fiber E as the first core-sheath type composite fiber. In addition, (2.0 + 3.3) /2=2.65 dtex, which is a mass average value of the fineness of the fiber C and the fineness of the fiber E, was used as the fineness of the second core-sheath composite fiber of Comparative Example 2.

(Production of nonwoven fabric of Example 3)
A method similar to the method described in Example 2 was used, except that the target weight of the first fiber layer was 12.5 g / m ² and the target weight of the second fiber layer was 12.5 g / m ^2. Thus, a nonwoven fabric of Example 3 was obtained.

(Production of the nonwoven fabric of Example 4)
Example 4 was repeated using the same method as described in Example 2 except that the target weight of the first fiber layer was 7 g / m ² and the target weight of the second fiber layer was 18 g / m ^2. Was obtained.

(Production of nonwoven fabric of Example 5)
The nonwoven fabric of Example 5 was produced using the same method as that described in Example 1 except that fiber C was used as the first core-sheath composite fiber and fiber G was used as the second core-sheath composite fiber. Got.

(Production of the nonwoven fabric of Example 6)
A nonwoven fabric of Example 6 was obtained using the same method as that described in Example 1 except that the fiber H was used as the second core-sheath type composite fiber.

(Production of the nonwoven fabric of Example 7)
A nonwoven fabric of Example 7 was obtained using the same method as that described in Example 2, except that 80% by mass of the fiber C and 20% by mass of the fiber F were mixed.

(Production of the nonwoven fabric of Comparative Example 3)
The nonwoven fabric of Comparative Example 3 was produced using the same method as that described in Example 1 except that fiber G was used as the first core-sheath composite fiber and fiber G was used as the second core-sheath composite fiber. Got.

(Production of the nonwoven fabric of Comparative Example 4)
A nonwoven fabric of Comparative Example 4 was obtained using the same method as that described in Example 1 except that the fiber G was used as the second core-sheath type composite fiber.

不織布 The nonwoven fabrics of Examples 1 to 7 and Comparative Examples 1 to 4 were measured for thickness, specific volume, strength and elongation, flexibility, touch (smoothness), touch (softness), and fluffiness. The results are shown in Tables 1 to 3. In addition, these measuring methods and evaluation methods are shown below.

<Measurement of nonwoven fabric thickness and specific volume>
The thickness of the nonwoven fabric (including the nonwoven fabric sample) was measured using a thickness measuring machine (trade name: THICKNESS GAUGE model CR-60A manufactured by Daiei Kagaku Seiki Seisaku-sho, Ltd.) with a load of 294 Pa applied to the nonwoven fabric. .
The specific volume was determined by calculation from the basis weight and the thickness.

<Measurement of tensile strength, elongation, and stress at 10% elongation of nonwoven fabric>
According to JIS L 1913 (2010) 1096 6.312.1 A method (strip method), using a constant-speed tension type tensile tester, the width of a sample piece is 5 cm, the grip interval is 10 cm, and the tensile speed is 30 ± 2 cm / min. , A load value (tensile strength), an elongation, and a stress at 10% elongation at the time of cutting were measured. The tensile test was performed with the longitudinal direction (MD direction) and the lateral direction (CD direction) of the nonwoven fabric as the tensile direction. Each value was measured for three samples, and the average value was shown.

<Measurement of rigidity>
The rigidity of the nonwoven fabric was measured according to JIS L 1096 (2010) 8.21.5 E method (handle ometer method). Specifically, it measured by the following procedures.
A sample piece having a size of 20 cm × 20 cm in the MD direction × CD direction is placed on the sample table so that the measurement direction of the sample piece is perpendicular to the slot (gap width: 10 mm).
Next, the blade of the penetrator adjusted so as to be lowered to 8 mm from the surface of the sample table is lowered, and when the sample piece is pushed in, 6.7 cm (１／ of the width of the sample piece) from one of the sides is obtained. At the position, the resistance value against the pressing in is read at different positions (total of four positions) in the MD (vertical) direction and the CD (horizontal) direction, respectively. The highest value (cN) indicated by the microammeter is read as the resistance value. The sum of the maximum values of the two sides in the MD direction is obtained as the bending stiffness (cN) in the MD direction, and the sum of the maximum values of the two sides in the CD direction is obtained as the bending stiffness (cN) in the CD direction. . The total value of the bending resistance in the MD direction and the bending resistance in the CD direction is defined as the bending resistance (cN) of the entire nonwoven fabric. Note that the maximum value of each side is an average value obtained by performing three measurements.

<Measurement of tactile sensation (smoothness, softness)>
Sensory evaluation was performed by 12 panelists. The sensory evaluation was evaluated by each panelist according to the following five-point criteria, and the average value of the evaluations of 12 persons was calculated.
Smoothness sensory evaluation criteria 5: Very smooth 4: Smooth 3: Normal 2: Slightly rough 1: Rough Softness sensory evaluation criteria 5: Very soft 4: Soft 3: Normal 2 : A little hard 1: Hard

<Evaluation of fluffiness>
A friction test (Abrasion Test) was performed using a Martindale fluff tester (trade name “Martindale Abrasion and Pilling Tester No. 1309” manufactured by James Heal).
Two samples (140 mm in diameter and 38 mm in diameter each) were prepared for the nonwoven fabrics of Examples and Comparative Examples. A felt having a diameter of 140 mm was placed on a friction table (Abrading Table), and a sample having a diameter of 140 mm was laminated instead of the SM25 friction cloth (SM25 Abrasice Cloth), and the sample was fixed with a clamping ring (Clamp Ring). Next, a sample having a diameter of 38 mm and polyurethane having a diameter of 38 mm were placed in a sample holder (Sample Holder), and the sample holder was placed on a table (Abrading Tables) without placing a loading weight on the sample holder. The two samples were set on a tester such that the first fiber layers were in contact with each other. A friction test was performed by setting the number of friction times to 100 and setting the motion to 60.5 mm Lissajous motion. The two samples after the friction test were observed, the presence or absence of breakage of the nonwoven fabric was confirmed, and the number of fluff was counted. Three friction tests were performed (using a total of six samples). The average value of the number of fluffs was recorded. A break in the nonwoven fabric was recorded as torn if observed in one of the three tests, and torn if none was observed.

In the nonwoven fabrics of Examples 1 to 7, the first fiber layer contains the first core-sheath composite fiber, the second fiber layer contains the second core-sheath composite fiber and cotton, The fineness of the conjugate fiber is smaller than the fineness of the second sheath-core composite fiber, and the difference between the fineness F1 of the first sheath-core composite fiber and the fineness F2 of the second sheath-core composite fiber (F2-F1) Is not less than 0.1 dtex and not more than 1.5 dtex, and satisfies at least one of the following (i) and (ii).
(I) The sheath component of the first sheath-core composite fiber and the sheath component of the second sheath-core composite fiber include polyethylene, and the heat of fusion ΔH of the sheath component of the first sheath-core composite fiber is 130 J / g. The heat of fusion ΔH of the sheath component of the second core-sheath composite fiber is 130 J / g or more.
(Ii) The sheath component of the first core-sheath composite fiber and the sheath component of the second core-sheath composite fiber both include at least one selected from high-density polyethylene and medium-density polyethylene.
Therefore, the nonwoven fabrics of Examples 1 to 7 exhibit a smooth and soft touch while having excellent nonwoven fabric strength. Further, the nonwoven fabrics of Examples 1 to 7 have little fuzz and tear of the nonwoven fabric.

Further, in the nonwoven fabrics of Examples 1 to 7, the first fiber layer contains the first core-sheath type composite fiber, the second fiber layer contains the second core-sheath type composite fiber and cotton, The fineness of the sheath-type composite fiber is smaller than the fineness of the second core-sheath type composite fiber, and the ratio (F1 / F1) between the fineness F1 of the first core-sheath type composite fiber and the fineness F2 of the second core-sheath type composite fiber F2) is 0.55 or more, smaller than 1, and satisfies at least one of the following (i) and (ii).
(I) The sheath component of the first sheath-core composite fiber and the sheath component of the second sheath-core composite fiber include polyethylene, and the heat of fusion ΔH of the sheath component of the first sheath-core composite fiber is 130 J / g. The heat of fusion ΔH of the sheath component of the second core-sheath composite fiber is 130 J / g or more.
(Ii) The sheath component of the first core-sheath composite fiber and the sheath component of the second core-sheath composite fiber both include at least one selected from high-density polyethylene and medium-density polyethylene.
Therefore, the nonwoven fabrics of Examples 1 to 7 exhibit a smooth and soft touch while having excellent nonwoven fabric strength. Further, the nonwoven fabrics of Examples 1 to 7 have little fuzz and tear of the nonwoven fabric.

On the other hand, in the nonwoven fabric of Comparative Example 1, the heat of fusion ΔH of at least one of the sheath component of the first core-sheath composite fiber and the sheath component of the second core-sheath composite fiber is less than 130 J / g. Alternatively, in the nonwoven fabric of Comparative Example 1, at least one of the sheath component of the first sheath-core composite fiber and the sheath component of the second sheath-core composite fiber is not high-density polyethylene. Therefore, the nonwoven fabric of Comparative Example 1 does not exhibit a smooth and soft touch while having excellent nonwoven fabric strength. Furthermore, the nonwoven fabric of Comparative Example 1 has many fluffs, and the nonwoven fabric is broken.

In the nonwoven fabric of Comparative Example 2, the fineness of the first core-sheath composite fiber is not smaller than the fineness of the second core-sheath composite fiber. Therefore, the nonwoven fabric of Comparative Example 2 does not exhibit a smooth and soft touch.
The nonwoven fabric of Comparative Example 2 used bulky fiber (fiber E), but did not show a smooth and soft touch, and used a bulky fiber with less fuzz. As a result, the nonwoven fabric is broken.

不織布 In the nonwoven fabric of Comparative Example 3, the fineness of the first core-sheath composite fiber is the same as that of the second sheath-core composite fiber. Therefore, the nonwoven fabric of Comparative Example 3 does not have a sufficient tactile sensation.

不織布 In the nonwoven fabric of Comparative Example 4, the difference (F2-F1) between the fineness of the first core-sheath composite fiber and the fineness of the second core-sheath composite fiber is 1.6 dtex. Further, the ratio (F1 / F2) of the fineness of the first core-sheath composite fiber to the fineness of the second core-sheath composite fiber is 0.52. Therefore, the nonwoven fabric of Comparative Example 4 has a lot of fluff and breaks the nonwoven fabric.

すると Comparing Examples 2 to 4, Examples 2 and 4 were slightly superior to Example 3 in softness of the nonwoven fabric. In Examples 2 and 4, since the basis weight of the first fiber layer is smaller than the basis weight of the second fiber layer, it is assumed that the softness of the nonwoven fabric is improved.

The nonwoven fabric for an absorbent article according to the embodiment of the present invention has a good tactile sensation, can reduce fluff and tear of the nonwoven fabric, and can be suitably used as a back sheet.

Related Application This application claims priority based on Article 4 of the Paris Convention based on Japanese Patent Application No. 2018-122291 filed on June 27, 2018 in Japan. The contents of this basic application are incorporated herein by reference.

Claims

A nonwoven fabric comprising a first fiber layer and a second fiber layer located on one main surface of the first fiber layer,
The first fiber layer includes a first sheath-core composite fiber,
The second fiber layer includes a second sheath-core composite fiber and cotton,
The fineness of the first sheath-core composite fiber is smaller than the fineness of the second sheath-core composite fiber,
The difference between the fineness of the first core-sheath composite fiber and the fineness of the second core-sheath composite fiber is 0.1 dtex or more and 1.5 dtex or less,
The sheath component of the first sheath-core composite fiber and the sheath component of the second sheath-core composite fiber include polyethylene,
The heat of fusion ΔH of the sheath component of the first core-sheath type composite fiber is 130 J / g or more;
The heat of fusion ΔH of the sheath component of the second core-sheath composite fiber is 130 J / g or more;
Nonwoven fabric for absorbent articles.
A nonwoven fabric comprising a first fiber layer and a second fiber layer located on one main surface of the first fiber layer,
The first fiber layer includes a first sheath-core composite fiber,
The second fiber layer includes a second sheath-core composite fiber and cotton,
The fineness of the first sheath-core composite fiber is smaller than the fineness of the second sheath-core composite fiber,
The difference between the fineness of the first core-sheath composite fiber and the fineness of the second core-sheath composite fiber is 0.1 dtex or more and 1.5 dtex or less,
The sheath component of the first sheath-core composite fiber and the sheath component of the second sheath-core composite fiber both include at least one selected from high-density polyethylene and medium-density polyethylene,
Nonwoven fabric for absorbent articles.
A nonwoven fabric comprising a first fiber layer and a second fiber layer located on one main surface of the first fiber layer,
The first fiber layer includes a first sheath-core composite fiber,
The second fiber layer includes a second sheath-core composite fiber and cotton,
The fineness of the first sheath-core composite fiber is smaller than the fineness of the second sheath-core composite fiber,
The ratio between the fineness of the first core-sheath type composite fiber and the fineness of the second core-sheath type composite fiber is 0.55 or more, and is smaller than 1;
The sheath component of the first sheath-core composite fiber and the sheath component of the second sheath-core composite fiber include polyethylene,
The heat of fusion ΔH of the sheath component of the first core-sheath type composite fiber is 130 J / g or more;
The heat of fusion ΔH of the sheath component of the second core-sheath composite fiber is 130 J / g or more;
Nonwoven fabric for absorbent articles.
A nonwoven fabric comprising a first fiber layer and a second fiber layer located on one main surface of the first fiber layer,
The first fiber layer includes a first sheath-core composite fiber,
The second fiber layer includes a second sheath-core composite fiber and cotton,
The fineness of the first sheath-core composite fiber is smaller than the fineness of the second sheath-core composite fiber,
The ratio between the fineness of the first core-sheath type composite fiber and the fineness of the second core-sheath type composite fiber is 0.55 or more, and is smaller than 1;
The sheath component of the first sheath-core composite fiber and the sheath component of the second sheath-core composite fiber both include at least one selected from high-density polyethylene and medium-density polyethylene,
Nonwoven fabric for absorbent articles.
(5) The nonwoven fabric for an absorbent article according to any one of (1) to (4), wherein the fineness of the first core-sheath composite fiber is 1.0 dtex or more and 2.0 dtex or less.
(6) The nonwoven fabric for an absorbent article according to any one of (1) to (5), wherein the fineness of the second core-sheath type composite fiber is 1.7 dtex or more and 2.6 dtex or less.
The nonwoven fabric for an absorbent article according to any one of claims 1 to 6, wherein the melt flow rate of the sheath component of the first core-sheath composite fiber is 15 g / 10 minutes or more.
The nonwoven fabric for an absorbent article according to any one of claims 1 to 7, wherein the melt flow rate of the sheath component of the second core-sheath composite fiber is 10 g / 10 minutes or more.
The absorbent according to any one of claims 1 to 8, wherein the second fiber layer contains the cotton in a ratio of 1% by mass or more and 30% by mass or less based on the total mass of the second fiber layer. Non-woven fabric for goods.
不織布 The nonwoven fabric for an absorbent article according to any one of claims 1 to 9, wherein the softness of the nonwoven fabric is 16.0 cN or less.
The nonwoven fabric for an absorbent article according to any one of claims 1 to 10, wherein the basis weight of the first fiber layer is smaller than the basis weight of the second fiber layer.
A backsheet for an absorbent article, comprising the nonwoven fabric for an absorbent article according to any one of claims 1 to 11.
An absorbent article comprising the backsheet for an absorbent article according to claim 12, wherein the first fiber layer of the backsheet for an absorbent article according to claim 12 is arranged on a side near a user's clothes. .
Producing a first fibrous web comprising a first core-sheath composite fiber;
Producing a second fibrous web comprising a second core-sheath composite fiber and cotton;
Superimposing and integrating the first fiber web and the second fiber web,
A method for producing a nonwoven fabric for absorbent articles, comprising:
The fineness of the first sheath-core composite fiber is smaller than the fineness of the second sheath-core composite fiber,
The difference between the fineness of the first core-sheath composite fiber and the fineness of the second core-sheath composite fiber is 0.1 dtex or more and 1.5 dtex or less,
The sheath component of the first sheath-core composite fiber and the sheath component of the second sheath-core composite fiber include polyethylene,
The heat of fusion ΔH of the sheath component of the first core-sheath type composite fiber is 130 J / g or more;
The heat of fusion ΔH of the sheath component of the second core-sheath composite fiber is 130 J / g or more;
A method for producing a nonwoven fabric for an absorbent article.
Producing a first fibrous web comprising a first core-sheath composite fiber;
Producing a second fibrous web comprising a second core-sheath composite fiber and cotton;
Superimposing and integrating the first fiber web and the second fiber web,
A method for producing a nonwoven fabric for absorbent articles, comprising:
The fineness of the first sheath-core composite fiber is smaller than the fineness of the second sheath-core composite fiber,
The difference between the fineness of the first core-sheath composite fiber and the fineness of the second core-sheath composite fiber is 0.1 dtex or more and 1.5 dtex or less,
The sheath component of the first sheath-core composite fiber and the sheath component of the second sheath-core composite fiber both include at least one selected from high-density polyethylene and medium-density polyethylene,
A method for producing a nonwoven fabric for an absorbent article.
Producing a first fibrous web comprising a first core-sheath composite fiber;
Producing a second fibrous web comprising a second core-sheath composite fiber and cotton;
Superimposing and integrating the first fiber web and the second fiber web,
A method for producing a nonwoven fabric for absorbent articles, comprising:
The fineness of the first sheath-core composite fiber is smaller than the fineness of the second sheath-core composite fiber,
The ratio between the fineness of the first core-sheath type composite fiber and the fineness of the second core-sheath type composite fiber is 0.55 or more, and is smaller than 1;
The sheath component of the first sheath-core composite fiber and the sheath component of the second sheath-core composite fiber include polyethylene,
The heat of fusion ΔH of the sheath component of the first core-sheath type composite fiber is 130 J / g or more;
The heat of fusion ΔH of the sheath component of the second core-sheath composite fiber is 130 J / g or more;
A method for producing a nonwoven fabric for an absorbent article.
Producing a first fibrous web comprising a first core-sheath composite fiber;
Producing a second fibrous web comprising a second core-sheath composite fiber and cotton;
Superimposing and integrating the first fiber web and the second fiber web,
A method for producing a nonwoven fabric for absorbent articles, comprising:
The fineness of the first sheath-core composite fiber is smaller than the fineness of the second sheath-core composite fiber,
The ratio between the fineness of the first core-sheath type composite fiber and the fineness of the second core-sheath type composite fiber is 0.55 or more, and is smaller than 1;
The sheath component of the first sheath-core composite fiber and the sheath component of the second sheath-core composite fiber both include at least one selected from high-density polyethylene and medium-density polyethylene,
A method for producing a nonwoven fabric for an absorbent article.
18. The method for producing a nonwoven fabric for an absorbent article according to any one of claims 14 to 17, wherein the fineness of the first core-sheath composite fiber is 1.0 dtex or more and 2.0 dtex or less.
方法 The method for producing a nonwoven fabric for absorbent articles according to any one of claims 14 to 18, wherein the fineness of the second core-sheath type composite fiber is from 1.7 dtex to 2.6 dtex.
20. The method for producing a nonwoven fabric for absorbent articles according to any one of claims 14 to 19, wherein the melt flow rate of the sheath component of the first core-sheath type conjugate fiber is 15 g / 10 minutes or more.
The method for producing a nonwoven fabric for an absorbent article according to any one of claims 14 to 20, wherein the melt flow rate of the sheath component of the second core-sheath composite fiber is 10 g / 10 minutes or more.
The absorbent according to any one of claims 14 to 21, wherein the second fiber web contains the cotton at a ratio of 1% by mass or more and 30% by mass or less based on the total mass of the second fiber web. A method for producing a nonwoven fabric for articles.
The method for producing a nonwoven fabric for an absorbent article according to any one of claims 14 to 22, wherein the basis weight of the first fiber web is smaller than the basis weight of the second fiber web.