WO2022138521A1

WO2022138521A1 - Absorbent article

Info

Publication number: WO2022138521A1
Application number: PCT/JP2021/046899
Authority: WO
Inventors: 裕美立川; 奈美江糸井; 将也金子
Original assignee: 花王株式会社
Priority date: 2020-12-23
Filing date: 2021-12-20
Publication date: 2022-06-30
Also published as: CN116600760A; TW202233148A; JP2022099580A

Abstract

An absorbent article (1) according to the present invention has side flap parts (SF) on both sides of an absorbent main body (5), each of said side flap parts being formed of a sheet that extends outwardly beyond a side edge of an absorber (4) along the longitudinal direction (X). Each of the side flap parts (SF) is configured so as to comprise a stretchable sheet; and the elongation recovery ratio of the side flap parts (SF) is 50% or more at 30% elongation. The absorber (4) contains water absorbent fibers, a water absorbent polymer, and a plurality of fiber masses containing synthetic fibers; and the plurality of fiber masses are interlaced with each other, or alternatively, the fiber masses and the water absorbent fibers are interlaced with each other.

Description

Absorbent article

The present invention relates to an absorbent article.

Absorbent articles such as menstrual napkins are generally arranged on the absorbent body, which is the main liquid absorbing site, and the longitudinal side edge of the absorbent body, and extend laterally outward from the absorbent body. It has a side flap portion formed by a sheet. As an absorbent article having the side flap portion, the present applicant has previously proposed an absorbent article containing a sheet in which the side flap portion exhibits extensibility in a predetermined direction (Patent Document 1 and). 2).

Further, in Patent Document 3, the torsional torque value of the rear side region located on the rear side of the wearer when worn is higher than the torsional torque value of the excretion opening corresponding region corresponding to the wearer's excretion port when worn. Described are absorbent articles that are also smaller and less than 8 mN, the posterior region comprising an elongated region and the cloaca corresponding region comprising a low elongated region.

By the way, the applicant has previously examined the composition of the absorber, and from the viewpoint of cushioning property, resistance to wobbling, and liquid drawability, the present applicant has previously considered an absorber composed of a fiber mass containing synthetic fibers. It proposes an absorbent article to be provided (Patent Document 4). In such an absorber, the content mass ratio of the fiber mass to the water-absorbent fiber is smaller on the skin-facing surface side than on the non-skin facing surface side of the absorber.

Japanese Unexamined Patent Publication No. 2008-055109 Japanese Unexamined Patent Publication No. 2009-153736 Japanese Unexamined Patent Publication No. 2017-119049 U.S. Patent Application Publication No. 2020/289343

The present invention has a vertical direction corresponding to the front-back direction of the wearer and a horizontal direction orthogonal to the vertical direction, and is a liquid-permeable front sheet, a liquid-impervious back sheet, and absorption arranged between these two sheets. Absorbent article with body The subject is an absorbent article with a body.
The absorbent article preferably has side flaps on both sides of the absorbent body, which are made of sheets extending outward from the longitudinally side edges of the absorber.
The side flap portion is configured to include an elastic sheet, and it is preferable that the elastic sheet has an elongation recovery rate of 50% or more when it is extended by 30%.
The absorber contains a plurality of fiber lumps including a water-absorbent fiber, a water-absorbent polymer, and a synthetic fiber, and the plurality of fiber lumps or the fiber lumps and the water-absorbent fibers are entangled with each other. preferable.

FIG. 1 is a plan view schematically showing a skin-facing surface side (surface sheet side) of a sanitary napkin according to an embodiment of the absorbent article of the present invention. FIG. 2 is a sectional view taken along line II-II of FIG. 3A and 3B are perspective views showing an embodiment of the fiber mass according to the present invention, respectively. FIG. 4 is an explanatory diagram of a method for producing a fiber mass shown in FIG. 3 (a). 5 (a) to 5 (c) are schematic views for explaining the method of measuring the torsional torque value in the embodiment.

Detailed description of the invention

From the viewpoint of making the body easier to move in the wearing state, it is desirable that the absorbent article has excellent followability to the movement of the wearer's body. However, if only such followability is enhanced, the absorbent article is easily deformed and twisted, or the absorbent article is easily moved and a gap is formed between the absorbent article and the body. .. As a result, there is a risk of liquid leakage, and the wearing feeling and fit are impaired, which may cause anxiety about leakage to the wearer. The absorbent articles described in Patent Documents 1 to 4 have room for improvement in that they improve the followability to the movement of the wearer's body while maintaining the fit.

Therefore, the present invention relates to an absorbent article that is excellent in following the movement of the wearer's body while maintaining the fit.

Hereinafter, the absorbent article of the present invention will be described based on the preferred embodiment thereof with reference to the drawings. 1 and 2 show a menstrual napkin 1 (hereinafter, also simply referred to as “napkin 1”), which is an embodiment of the absorbent article of the present invention. The napkin 1 has an absorber 4 that absorbs and retains body fluid, a surface sheet 2 that is arranged on the skin-facing surface side of the absorber 4 and can come into contact with the wearer's skin, and a non-skin-facing surface of the absorber 4. It is provided with a back surface sheet 3 arranged on the front surface side.
As shown in FIG. 1, the napkin 1 has a vertical direction X extending from the ventral side of the wearer to the dorsal side via the crotch portion and a lateral direction Y orthogonal to the vertical direction X corresponding to the front-back direction of the wearer. is doing. In the vertical direction X, the napkin 1 has a central region B including an excretory portion facing portion (excretion point) arranged to face the excretory portion such as the vulva of the wearer when worn, and a vertical X front side of the central region B. It has an anterior region A arranged on (ventral side of the wearer) and a posterior region C arranged on the posterior side (dorsal side of the wearer) in the vertical direction X from the central region B. It is classified.

In the present specification, the "skin facing surface" is a surface of the absorbent article or its constituent members (for example, the absorbent body 4) that is directed toward the wearer's skin side when the absorbent article is worn, and is a "non-skin facing surface". Is a surface of the absorbent article or its constituent members that is directed to the side opposite to the skin side when the absorbent article is worn. That is, the skin-facing surface is the surface relatively close to the wearer's skin, and the non-skin-facing surface is the surface relatively far from the wearer's skin. "When worn" and "wearing state" mean a normal proper wearing position, that is, a state in which the proper wearing position of the absorbent article is maintained and worn.

The napkin 1 of the present embodiment has an absorbent body 5 having a shape long in the vertical direction X. The absorbent main body 5 is a portion that forms the main body of the napkin 1, and includes the front surface sheet 2, the back surface sheet 3, and the absorbent body 4.
The front surface sheet 2 covers the entire area of the skin-facing surface of the absorber 4, and the back surface sheet 3 covers the entire non-skin-facing surface of the absorber 4.

As the surface sheet 2, various types conventionally used for absorbent articles such as menstrual napkins can be used without particular limitation. For example, a non-woven fabric having a single-layer or multi-layer structure or a liquid-permeable sheet such as a perforated film can be used. As the back surface sheet 3, a stretchable sheet described later, which is a liquid-impermeable sheet such as a moisture-permeable resin film, can be used.

The napkin 1 has side flap portions SF composed of sheets extending outward from the side edges along the vertical direction X of the absorber 4 on both side portions of the absorbent body 5. The side flap portion SF is a portion made of a sheet member extending outward in the horizontal direction Y from both side edges of the absorber 4 along the vertical direction X. The seat member constituting the side flap portion SF extends from the front region A to the rear region C via the central region B, and extends laterally Y outward from each of both side edges of the absorber 4. The parts are joined to each other by known joining means such as an adhesive, a heat seal, and an ultrasonic seal. The side flap portion SF of the present embodiment includes a back surface sheet 3 and a side sheet 6 extending outward in the lateral direction Y from both side edges of the absorber 4.

The side flap portion SF may have a pair of wing portions extending outward in the lateral direction Y from the peripheral portion on both the left and right sides of the absorbent main body 5 along the vertical direction X. Examples of the form of the pair of wing portions include those in which the napkin 1 is divided into two in the horizontal direction Y and formed symmetrically with respect to the vertical center line extending in the vertical direction X. In this case, the base of the front side (front region A side) of one wing portion and that of the other wing portion are at the same position in the vertical direction X.
The wing portion generally has an adhesive portion (not shown) for fixing the wing portion to clothing such as shorts on the non-skin facing surface. Further, the wing portion is used by being folded back to the non-skin facing surface (outer surface) side of the crotch portion of clothing such as shorts. Therefore, the non-skin facing surface of the wing portion, which is the forming surface of the adhesive portion, is directed to the skin side of the wearer at the time of use and becomes the skin facing surface. Before its use, the adhesive portion is covered with a release sheet (not shown) made of a film, a non-woven fabric, paper or the like.

When the side flap portion SF has a wing portion, the central region B is a region having a wing portion in the vertical direction X. Specifically, a virtual straight line extending in the horizontal direction Y through the front base of the vertical direction X in each of the pair of wing portions, and a virtual straight line extending in the horizontal direction Y through the rear base of each of the pair of wing portions. The region sandwiched between the straight lines is the central region B.

The side flap portion SF of this embodiment does not have a wing portion. In the case of having no wing portion (for example, a disposable diaper), the central region B may be a region facing the excretory portion, and typically when the absorbent article is divided into three equal parts in the vertical direction X. It is an area located in the center of.

In the napkin 1 of the present embodiment, the pair of

side sheets

6 and 6 overlap the skin-facing surface of the absorbent body 5, that is, both sides of the surface sheet 2 along the vertical direction X in the skin-facing surface of the absorbent body 5. It is arranged over substantially the entire length of the vertical direction X. The side sheet 6 extends outward from both side edges along the vertical direction X of the absorber 4 in the lateral direction Y to form a skin-facing surface of the side flap portion SF. The pair of

side sheets

6 and 6 are joined to the surface sheet 2 and other members by a known joining means such as an adhesive or heat embossing. The form in which the surface sheet 2 and the

side sheets

6 and 6 overlap each other includes a form in which both

sheets

2 and 6 are in contact with each other and a form in which the

side sheets

6 and 6 are not in contact with each other.

The side flap portion SF is configured to include an elastic sheet. As for the side flap portion SF, all the sheets constituting the side flap portion SF may be elastic sheets, or some of the sheets constituting the side flap portion SF may be elastic sheets. In the present embodiment, either or both of the side sheet 6 and the back surface sheet 3 of the side flap portion SF are elastic sheets.
The stretchable sheet is a sheet that exhibits elasticity in at least one direction. The stretchable sheet is a sheet having an elongation recovery rate (%) of 50% or more at the time of 30% elongation measured by the [measurement method of elongation recovery rate] described later. From the viewpoint of further improving the followability of the wearer to the body, which will be described later, the elongation recovery rate (%) of the elastic sheet at 30% elongation is preferably 55% or more, more preferably 60% or more. The upper limit of the elongation recovery rate (%) at the time of such 30% elongation is not particularly limited, but is practically 80% or less.

The length of the elastic sheet at the time of "30% extension" is the elastic sheet in the side flap portion SF located in the inseam (central region B) with the movement when the wearer exercises such as walking. However, it corresponds to the length that can be deformed in the expansion / contraction direction (extension length). According to the present inventor, if the "elongation recovery rate (%) at the time of 30% elongation" of the elastic sheet in the side flap portion SF is 50% or more, the side flap portion SF even when the wearer is exercising. It was found that the distortion of the is small and it is easy to return to the original length.
When the side flap portion SF includes two or more elastic sheets, the one having the larger tensile load (N) at the time of 30% elongation measured in [Measuring method of elongation recovery rate] described later. In the stretchable sheet of No. 1, the elongation recovery rate at the time of 30% elongation may be 50% or more. Further, when the side flap portion SF is configured to include the stretchable sheet and the non-stretchable sheet, the non-stretchable sheet can be stretched following the stretchable sheet at the time of 30% stretching. All you need is. The above-mentioned "extensible" means that (a) the constituent fibers of the sheet themselves are elongated, and (b) even if the constituent fibers themselves are not elongated, the fibers bonded at the intersections are separated from each other by machining or the like. This includes the case where the three-dimensional structure formed by a plurality of fibers is structurally changed due to the bonding between the fibers, or the constituent fibers are torn off, and the sheet as a whole is stretched. As such an stretchable non-stretchable sheet, for example, a sheet capable of plastic deformation (plastic fracture) can be used. The "non-stretchable sheet" is a sheet having a stretch recovery rate (%) of less than 50% when stretched by 30%.
From the viewpoint of further improving the followability of the wearer's body movement, which will be described later, it is more preferable that the elongation recovery rate of the side flap portion SF at 30% extension is 50% or more.

[Measurement method of elongation recovery rate]
Take out the sheet to be measured from the side flap portion SF. At this time, the sheet to be measured is peeled off using a dryer, cold spray, or the like and taken out. When the side flap portion SF is composed of two or more sheets, each sheet is made independent by using a dryer, cold spray, or the like. Next, a size of 120 mm in length and 30 mm in width is cut out from the sheet to be measured, and this is used as a sample piece. The sample piece is cut so that its longitudinal direction coincides with the expansion / contraction direction. Next, a tensile tester (Small tabletop tester "EZTest" EZ-L manufactured by Shimadzu Corporation) is used to fix the sample pieces between the chucks. At this time, the sample piece is fixed between the chucks so that the expansion / contraction direction of the sample piece coincides with the tension direction (extension direction) by the tensile tester. The distance between the chucks is 100 mm (K0).
The elongation recovery rate (%) at the time of 30% elongation of the sheet to be measured is obtained by the following method. The sample piece is stretched at a speed of 200 mm / min to the length K30 at the time of 30% stretching, and then contracted at the same speed until the stress becomes zero. This expansion and contraction is repeated 3 times. The "length K30 at the time of 30% extension" is the length when the sample piece between the chucks is extended until the length becomes 1.3 times the distance K0 (100 mm) between the chucks (the length at the time of extension K30). K30 = K0 × 1.3). Then, the elongation recovery rate at the time of 30% elongation is calculated from the following equation. In the following equation, W1 is the tensile work amount at the time of the first extension, and W3 is the tensile work amount at the time of the third extension. Each tensile work amount is obtained by multiplying the tensile load (N) by the elongation amount (K30-K0) at the time of 30% elongation, and is calculated using the data processing software "TRAPEZIUMX" (Shimadzu Corporation).
Elongation recovery rate (%) at the time of 30% elongation = W3 / W1 × 100

When measuring the elongation recovery rate of the side flap portion SF, a size of 120 mm in length and 30 mm in width is cut out from the side flap portion SF so as to include the entire thickness direction, and this is used as a sample piece and elongated by the method described above. Measure the recovery rate. Such a sample piece is also cut out so that its longitudinal direction coincides with the expansion / contraction direction.

As shown in FIG. 1, the absorber 4 extends substantially the entire length of the napkin 1 (absorbent body 5) in the vertical direction X. In other words, the absorber 4 extends from the anterior region A to the posterior region C via the central region B.
The absorber 4 in the present embodiment includes a liquid-absorbing absorbent core 40 and a liquid-permeable core wrap sheet 41 that covers the outer surface of the absorbent core 40. The absorbent core 40 is the main body of the absorber 4, and has a long shape in the vertical direction X in a plan view as shown in FIG. The absorbent core 40 is arranged on the napkin 1 so that its longitudinal direction coincides with the vertical direction X of the napkin 1. The absorbent core 40 and the core wrap sheet 41 may be bonded by an adhesive such as a hot melt adhesive.

In the present embodiment, the core wrap sheet 41 is one continuous sheet. As shown in FIG. 2, the core wrap sheet 41 covers the entire surface of the absorbent core 40 facing the skin, and is lateral to the side edges of the absorbent core 40 along the vertical direction X in the core wrap sheet 41. The extending portion extending outward in the direction Y is wound below the absorbent core 40 to cover the entire non-skin facing surface of the absorbent core 40. Instead, the core wrap sheet 41 covers the entire non-skin facing surface of the absorbent core 40, and in the core wrap sheet 41, from both side edges along the vertical direction X of the absorbent core 40 to the lateral direction Y. The outwardly extending portion may be rolled up above the absorbent core 40 to cover the entire skin-facing surface of the absorbent core 40. Further, the core wrap sheet 41 does not have to be one continuous sheet, for example, one skin side core wrap sheet covering the skin facing surface of the absorbent core 40 and a separate sheet thereof. It may be composed of two sheets, one non-skin side core wrap sheet covering the non-skin facing surface of the absorbent core 40.

The absorbent core 40 contains a water-absorbent material. The water-absorbent material includes the water-absorbent fiber 12F and the water-absorbent polymer 13. The absorbent core 40 of the present embodiment contains a water-absorbent fiber 12F and a water-absorbent polymer 13 as a water-absorbent material.
As the water-absorbent fiber 12F, a water-absorbent fiber conventionally used as a material for forming an absorber in this type of absorbent article can be used. Examples of the water-absorbent fiber include wood pulp such as coniferous tree pulp and broadleaf tree pulp, natural fiber such as non-wood pulp such as cotton pulp and hemp pulp; modified pulp such as cationized pulp and marcelled pulp; cupra, rayon and the like. Examples thereof include recycled fibers, and one of these can be used alone or in combination of two or more. Considering that the main role of the water-absorbent fiber 12F is to improve the liquid absorbency of the absorber 4, the water-absorbent fiber 12F is preferably a natural fiber or a regenerated fiber (cellulose fiber).

In the absorbent core 40 of the present embodiment, the water-absorbent fibers 12F are entangled with each other, but are not integrated like the constituent fibers 11F of the fiber mass 11, and are preferably present independently. The water-absorbent fiber 12F mainly contributes to the improvement of the liquid absorbency of the absorbent core 40, and also contributes to the improvement of the shape retention of the absorbent core 40.

A plurality of water-absorbent polymers 13 are present in the absorbent core 40 as small pieces of the water-absorbent polymer, and mainly contribute to the improvement of liquid absorbability in the absorbent core 40. The shape of the small piece of the water-absorbent polymer 13 is not particularly limited, and may be, for example, spherical, lumpy, bale-shaped, fibrous, or indefinite. The average particle size of the water-absorbent polymer 13 is preferably 10 μm or more, more preferably 100 μm or more, and preferably 1000 μm or less, more preferably 800 μm or less. As the water-absorbent polymer 13, a polymer or copolymer of acrylic acid or an alkali metal salt of acrylic acid can generally be used. Examples thereof include polyacrylic acid and salts thereof, and polymethacrylic acid and salts thereof. Specific examples thereof include acrylic acid polymers such as Aquaric CA and Aqualic CAW (both manufactured by Nippon Shokubai Co., Ltd.). Examples include partial sodium salts.

The absorbent core 40 contains a plurality of fiber lumps 11 together with a water-absorbent material. The constituent fibers 11F of the fiber mass 11 contain synthetic fibers such as thermoplastic fibers. As used herein, the term "fiber mass" is a fiber aggregate in which a plurality of fibers are grouped together and integrated. The method for producing the fiber mass is not particularly limited, and a fixed fiber aggregate such as a sheet piece obtained by cutting a synthetic fiber sheet (thermoplastic fiber sheet) having a certain size with a cutter or the like may be used. Alternatively, it was manufactured by crushing, peeling or tearing off a non-woven fabric mainly composed of thermoplastic fibers (synthetic fibers) into small pieces, such as the non-woven fabric pieces described in JP-A-2002-301105. It may be an amorphous fiber aggregate.

The absorber (absorbable core) may be in the form of i) containing only a fixed fiber aggregate as a fiber mass, or ii) a form containing only an amorphous fiber aggregate as a fiber mass. Alternatively, iii) the fiber mass may be in the form of a mixture of a fixed-shaped fiber aggregate and an atypical fiber aggregate. When the fiber mass 11 is a fixed fiber aggregate, the orientation of the constituent fibers is constant, so that the surface tends to be smooth. Since such fiber aggregates are less likely to be entangled with each other, they have a high degree of freedom of movement and can contribute to the flexibility of the absorber 4. From such a viewpoint, the fiber mass is preferably in the form of i). In the present embodiment, the fiber mass 11 is a fixed fiber aggregate.

The fiber lump 11 is a fiber aggregate in which a plurality of fibers 11F are integrated and integrated in a lump shape, and a plurality of fibers 11F are present in the absorbent core 40 while maintaining its morphology. The fiber mass 11 contributes to, for example, improvement of the flexibility, cushioning property, compression recovery property, and shape retention property of the absorbent core 40 due to the morphology of the fiber aggregate.

In the absorbent core 40 of the present embodiment, as shown in FIG. 2, a layer made of a water-absorbent fiber 12, a layer made of a water-absorbent polymer 13, and a layer made of a fiber mass 11 are formed in this order from the skin facing surface side. It is laminated. In such an absorber 4, a plurality of adjacent fiber masses 11 are entangled with each other.
Instead of the form shown in FIG. 2, in the absorbent core 40, the water-absorbent polymer 13 may be present in either one or both of the layer made of the water-absorbent fiber 12 and the layer made of the fiber mass 11. .. That is, the absorbent core 40 may have a layer in which the water-absorbent fiber 12 and the water-absorbent polymer 13 are mixed, or a layer in which the fiber mass 11 and the water-absorbent polymer 13 are mixed.
Further, instead of the form shown in FIG. 2, in the absorbent core 40, the fiber mass 11 may be uniformly distributed over the entire absorbent core 40 in the thickness direction Z of the absorber 4. In such a form, the water-absorbent material (water-absorbent fiber 12F and water-absorbent polymer 13) is uniformly distributed in the thickness direction Z together with the fiber mass 11. In this case, the adjacent fiber mass 11 and the water-absorbent fiber 12F are entangled with each other.
Further, in the absorbent core 40, the plurality of fiber lumps 11 may be entangled with the constituent fibers (

fibers

11F and 12F) in the absorbent core 40 to form one fiber lump continuum. As described above, at least a part of the plurality of fiber lumps 11 is entangled with other fiber lumps 11 or the water-absorbent fiber 12F.

Since the fiber mass 11 is an aggregate of fibers, the absorber 4 containing the fiber mass 11 has high absorption performance and abundant restoring force against compression. Further, since the side flap portion SF includes an elastic sheet having an elongation recovery rate of 50% or more when expanded by 30%, it can be easily expanded and contracted according to the movement of the wearer, and the distortion due to the expansion and contraction is small. .. The napkin 1 of the present embodiment provided with such an absorber 4 and a side flap portion SF is excellent in body fluid absorption performance, and the absorber 4 fits the wearer's skin well in a wearing state. The side flap portion SF expands and contracts so as to follow the wearer's body. In particular, since the side flap portion SF easily expands and contracts according to the movement of the body, the stress applied to the napkin 1 by the movement of the body is relaxed. Due to the above effects, the absorbent body 5 can be twisted while suppressing distortion even during exercise, and even if the absorber 4 is compressed due to the exercise, the absorbent body 4 is restored well, so that the napkin 1 fits. While maintaining sex, it has excellent followability to the wearer's physical movements. In such a napkin 1, a gap is unlikely to occur between the napkin 1 and the body, so that a stable wearing feeling can be obtained and the wearer is less likely to have anxiety about leakage. In addition, the napkin 1 is resistant to the shape loss caused by the movement of the body.

In the side flap portion SF, a sheet having a portion overlapping both side portions along the vertical direction of the surface sheet 2 and forming a skin facing surface of the side flap portion SF is referred to as a “skin surface sheet S1”. In the present embodiment, the skin surface sheet S1 is a side sheet 6.
Further, in the side flap portion SF, the sheet located on the non-skin facing surface side of the skin surface sheet S1 and forming the skin facing surface of the side flap portion SF is referred to as "non-skin surface sheet S2". In the present embodiment, the non-skin surface sheet S2 is the back surface sheet 3.

In the side flap portion SF, either one of the skin surface sheet S1 and the non-skin surface sheet S2 may be an elastic sheet. From the viewpoint of ensuring followability more reliably, it is preferable that one of the skin surface sheet S1 and the non-skin surface sheet S2 is an elastic sheet and the other is an stretchable sheet, and the skin surface sheet S1 and the non-skin surface sheet S1 and the non-skin surface sheet S2 are non-stretchable sheets. It is more preferable that the skin surface sheet S2 is an elastic sheet. When the side flap portion SF is composed of the stretchable sheet and the non-stretchable sheet, when the stretchable sheet is stretched by 30%, the non-stretchable sheet accompanies the stretching of the stretchable sheet. Is preferably expandable due to plastic deformation or the like.
From the viewpoint of further improving the followability during exercise such as walking, it is preferable that the side flap portion SF has elasticity in the vertical direction X, and both the skin surface sheet S1 and the non-skin surface sheet S2 are in the vertical direction X. It is more preferable that the elastic sheet has elasticity.
Further, the stretchable sheet used for either one or both of the skin surface sheet S1 and the non-skin surface sheet S2 may be a liquid impervious sheet or a liquid permeable sheet. Liquid impermeability is a concept that also includes liquid impermeable. From the viewpoint of further suppressing leakage, the stretchable sheet is preferably liquid impermeable. Liquid impermeability means the property that the sheet does not allow liquid to pass through at all, and liquid impermeability means the property that it is difficult for liquid to pass through, although it is not liquid impermeable.

In the present embodiment, the skin surface sheet S1 and the non-skin surface sheet S2 are bonded with an adhesive. From the viewpoint of ensuring the elasticity of the side flap portion SF more reliably, the adhesive for joining the skin surface sheet S1 and the non-skin surface sheet S2 is coated with a pattern having a non-coated portion (intermittent portion). It is preferable to have. Examples of such a pattern include a spiral shape, an omega shape, a striped shape, and the like.
From the same viewpoint as above, the coating area of the adhesive (the coating area of the adhesive / the area of the side flap portion SF) is preferably 10% or more, more preferably 20% or more with respect to the area of the side flap portion SF. It is preferably 80% or less, more preferably 60% or less, preferably 10% or more and 80% or less, and more preferably 20% or more and 60% or less. The adhesive is preferably a hot melt adhesive.

From the viewpoint of further improving the followability to the body, when both the skin surface sheet S1 and the non-skin surface sheet S2 are elastic sheets, each of the skin surface sheet S1 and the non-skin surface sheet S2 has the following physical properties. Is preferable.
Each of the skin surface sheet S1 and the non-skin surface sheet S2 has a tensile load of preferably 0.1 N or more, more preferably 1 N or more, and preferably 20 N or less, more preferably 15 N or less at the time of 30% elongation. Further, it is preferably 0.1 N or more and 20 N or less, and more preferably 1 N or more and 15 N or less.
The skin surface sheet S1 and the non-skin surface sheet S2 preferably have a smaller difference in tensile load during 30% elongation, preferably 5 N or less, and more preferably 4.8 N or less. The lower limit value is preferably closer to 0N, but is practically 0.01N or more. That is, the difference in tensile load between the skin surface sheet S1 and the non-skin surface sheet S2 at the time of 30% elongation is preferably 0N or more and 5N or less, and more preferably 0.01N or more and 4.8N or less.
As long as the stretch recovery rate of the stretchable sheet at 30% stretch is 50% or more, the value of the tensile load at 30% stretch of the stretchable sheet is not particularly limited, and it depends on the specific use of the napkin. Can be set as appropriate. For example, when the wearer sits with the napkin 1 fixed to the shorts, the pressure (tensile load) applied to the side flap portion SF is approximately 0.1 to 0.3 N, whereas the wearer wears it. The pressure applied to the side flap portion SF during the exercise is estimated to be about ten to several tens of times that when the person is seated. As described above, the pressure (tensile load) applied to the side flap portion SF differs depending on the exercise and other uses. More specifically, it is considered that the pressure (tensile load) applied to the side flap portion SF differs depending on the daytime or nighttime activity state (movement such as walking or standing, sitting, sleeping state) and the type of sports competition. Be done. Based on this, from the viewpoint of following the body and making it easier to obtain a good wearing feeling that is less likely to cause anxiety about leakage, the expansion and contraction load when the elastic sheet is extended by 30% is applied according to each application such as sports applications. It is preferable to set it. For example, when the absorbent article is a napkin for sports use, it is preferable that the tensile load of the stretchable sheet included in the side flap portion SF when stretched by 30% is 3N or more and 20N or less. Further, when both the skin surface sheet S1 and the non-skin surface sheet S2 are elastic sheets in a napkin for sports use, the tensile load of both sheets having a larger tensile load at 30% elongation is 3N or more and 20N or less. Is preferable.
The "tensile load at the time of 30% elongation" is the tensile load at the time of the first extension in the above-mentioned [method for measuring the elongation recovery rate], and is the tensile load applied to the sample piece at the "time of 30% elongation". The tensile load can be measured by the tensile tester. The measurement of such a tensile load is performed on three sample pieces taken from the sheet to be measured, and the average value of the tensile load is defined as "the tensile load at the time of 30% elongation".

From the same viewpoint as above, the stretchable sheet in the side flap portion SF has a 90 ° torsional torque value of preferably 0.01 Ncm or more, more preferably 0.1 N cm or more, and preferably 1.0 N cm or less, more preferably. Is 0.7 Ncm or less, preferably 0.01 N cm or more and 1.0 N cm or less, and more preferably 0.1 N cm or more and 0.7 N cm or less.
By providing the elastic sheet with the above physical characteristics, it is possible to make the napkin 1 easier to twist while further suppressing distortion. As a result, the wearer can be made easier to move and the wearing feeling can be further improved.

[Measurement of 90 ° torsion torque value]
The elastic sheet is taken out from the side flap portion SF, and a sample piece is further cut out from the elastic sheet. The sample piece is cut so as to have a length of 110 mm in the expansion / contraction direction and a width of 30 mm in the direction orthogonal to the expansion / contraction direction. Next, both ends of the sample piece in the longitudinal direction are sandwiched between upper and lower clamps provided by a tension control type torque tester (manufactured by Imada Co., Ltd.) to fix the sample piece, and the longitudinal direction of the sample piece is used as a rotation axis in the positive direction ( The upper clamp is reciprocated by 90 ° in the forward rotation) and the opposite direction (reverse rotation), and the torsional moment value (torque torque value) applied to the sample piece is measured. Such measurement is performed on five sample pieces, and the average of the maximum values in the forward and reverse directions of the torsional torque value is taken as the measured value. The tension applied to the sample piece during rotation is measured in the range of 3 to 6N. At the time of measurement, the length between the clamps is 70 mm under no tension. Further, the torque tester conforms to that shown in FIG. 2 of JIS K 7244-2.

From the viewpoint of not restricting the movement of the wearer and obtaining a better wearing feeling, the surface sheet 2 is preferably stretchable, and stretches in the same direction as the stretchable sheet of the side flap portion SF. It is more preferable to have sex. For example, when the elastic sheet in the side flap portion SF has elasticity in the vertical direction X, the surface sheet 2 preferably has elasticity in the vertical direction X, which is the same as the elastic sheet in the side flap portion SF. Is more preferable. In this case, the same sheet as the elastic sheet in the side flap portion SF can be used as the surface sheet 2.

The absorber 4 of the present embodiment does not have a configuration such as inserting a slit so that the absorber 4 has extensibility or elasticity. Further, the back surface sheet 3 in the present embodiment covers the entire non-skin facing surface of the absorber 4 and extends outward from each of the both side edges of the absorber 4 in the vertical direction X in the lateral direction. The extended portion constitutes the non-skin surface sheet S2 in the side flap portion SF. That is, the non-skin surface sheet S2 is continuous inward in the horizontal direction Y with respect to the side edge of the absorber 4 along the vertical direction X. When such a non-skin surface sheet S2 is an elastic sheet, the absorbent body 4 does not have elasticity, so that the non-skin surface sheet S2 does not exhibit elasticity at a portion overlapping with the absorbent body 4. As described above, when the non-skin surface sheet S2 is an elastic sheet, the portion of the non-skin surface sheet S2 located on the non-skin facing surface side of the absorber 4 is designed so as not to exhibit elasticity. Is preferable. Such a configuration is preferable in that the wearing feeling is further improved and the wearer is less likely to have anxiety about leakage.

From the viewpoint of further improving the followability, the length W1 of the side flap portion SF in the lateral direction Y (see FIG. 1) is preferably 10 with respect to the length W of the absorber 4 in the lateral direction Y (see FIG. 1). % Or more, more preferably 20% or more, preferably 100% or less, more preferably 80% or less, and preferably 10% or more and 100% or less, more preferably 20% or more and 80% or less.
From the same viewpoint as above, the length W1 (see FIG. 1) of the side flap portion SF in the lateral direction Y is preferably 10 mm or more, more preferably 20 mm or more, and preferably 70 mm or less, more preferably 50 mm or less. It is preferably 10 mm or more and 70 mm or less, and more preferably 20 mm or more and 50 mm or less.

From the viewpoint of further improving the fit, the thickness of the absorber 4 is preferably 1 mm or more, more preferably 2 mm or more, preferably 10 mm or less, more preferably 8 mm or less, and preferably 1 mm or more and 10 mm or less. , More preferably 2 mm or more and 8 mm or less.
The thickness of the absorber 4 is measured by the following method.

<Thickness measurement method>
The absorber is placed on a horizontal surface so as not to be wrinkled or bent, and the thickness of any part of the absorber is measured under a load of 5 cN / cm ² . For such thickness measurement, for example, a thickness meter PEACOCK DIAL UPRIGHT GAUGES R5-C (manufactured by OZAKI MFG.CO.LTD.) Is used. At this time, a plan-viewing circular or square plate (acrylic with a thickness of about 5 mm) whose size is adjusted so that the load is 5 cN / cm ² between the tip of the thickness gauge and the measurement sample (absorber). Place the plate) and measure the thickness. In the thickness measurement, any 10 points in the measurement sample are measured, and the average value of the thicknesses of those 10 points is calculated and used as the thickness of the measurement sample.

In the absorber 4 (absorbable core 40), the content mass ratio of the fiber mass 11 and the water-absorbent fiber 12F is not particularly limited, and the types of the constituent fibers (synthetic fiber) 11F and the water-absorbent fiber 12F of the fiber mass 11 and the like are not particularly limited. It may be adjusted appropriately according to the above. From the viewpoint of more reliably achieving the above-mentioned one or more effects, the content mass ratio of the fiber mass 11 and the water-absorbent fiber 12F in the absorbent core 40 is the former (fiber mass 11) / the latter (water-absorbent fiber 12F). ), It is preferably 20/80 to 80/20, and more preferably 40/60 to 60/40.

The content of the fiber mass 11 in the absorbent core 40 is preferably 20% by mass or more, more preferably 40% by mass or more, and preferably 80% by mass or less, based on the total mass of the absorbent core 40 in the dry state. , More preferably 60% by mass or less.
The content of the water-absorbent fiber 12F in the absorbent core 40 is preferably 20% by mass or more, more preferably 40% by mass or more, and preferably 80% by mass with respect to the total mass of the absorbent core 40 in a dry state. Below, it is more preferably 60% by mass or less.
The content of the water-absorbent polymer 13 in the absorbent core 40 is preferably 1% by mass or more, more preferably 5% by mass or more, and preferably 80% by mass with respect to the total mass of the absorbent core 40 in a dry state. Below, it is more preferably 50% by mass or less.
The term "dry absorbent core" as used herein means an absorbent core before absorbing body fluids.

In the absorber 4 of the present embodiment, the fiber lumps 11 are not uniformly distributed over the entire absorbent core 40 in the thickness direction Z, and more in the region on the non-skin facing surface side than in the region on the skin facing surface side. Exists (see Figure 2). That is, the region on the skin-facing surface side of the absorber 4 is the content mass ratio of the fiber lump 11 to the total mass of the water-absorbent fiber 12F and the fiber lump 11 (hereinafter, “fiber lump”) than the region on the non-skin facing surface side. (Also called "content ratio") is low. With such a configuration, the absorption amount of the absorber 4 can be further improved and leakage can be suppressed more effectively.
From the viewpoint of further improving the above effect, the fiber mass content ratio (%) in the region on the non-skin facing surface side of the absorber 4 and the fiber mass content mass ratio (%) in the region on the skin facing surface side of the absorber 4. ) Is preferably 20% or more, more preferably 40% or more, and preferably 100% or less.
It is preferable that the region of the absorber 4 on the skin-facing surface side does not contain fiber lumps. In this case, the fiber mass content mass ratio in the region facing the skin is 0%. On the other hand, when the water-absorbent fiber 12F is not contained in the region on the non-skin facing surface side, the fiber mass content mass ratio in the region on the non-skin facing surface side is 100%. Therefore, when the fiber mass content ratio is 0% in the region facing the skin and 100% in the region facing the non-skin, the difference between these regions is 100%. In such a form, the absorbent body 4 exhibits liquid absorption in the region on the skin-facing surface side and a good wearing feeling in the non-skin-facing surface side region, so that each function can be effectively exhibited. Is particularly preferable. However, when a large amount of excretory fluid flows into the absorber 4 in a short time, the excretory fluid cannot be completely absorbed in a short time in the region facing the skin, and a part of the excretory fluid is non-skin facing. It may flow into the area on the surface side. In that case, from the viewpoint of ensuring the absorption performance of the absorber 4 more reliably, the inclusion of some water-absorbing fibers in the region on the non-skin facing surface side may temporarily stock the excrement liquid in the region on the non-skin facing surface side. It is preferable in terms of points. From such a viewpoint, it is preferable that the water-absorbent fiber is contained in the region on the non-skin facing surface side so that the fiber mass content ratio is 80% or less. Therefore, the difference in the fiber mass content ratio described above is preferably 20% or more and 100% or less, and more preferably 40% or more and 100% or less.

The mass ratio of each fiber mass in the region on the skin facing surface side and the region on the non-skin facing surface side in the absorber 4 is measured by the following method. First, the absorber 4 is bisected in the thickness direction Z and divided into a region on the skin facing surface side and a region on the non-skin facing surface side. Next, the content mass of the water-absorbent fiber 12F and the content mass of the fiber mass 11 are measured for each of the region on the skin facing surface side and the region on the non-skin facing surface side. Ratio of the content mass of the fiber mass 11 to the total content mass of the water-absorbent fiber 12F and the fiber mass 11 for each of the region on the skin-facing surface side and the region on the non-skin-facing surface side [fiber mass 11 / (water-absorbent fiber 12F + fiber mass) 11)] is obtained, and this is used as the fiber mass content ratio.

The distribution of the water-absorbent polymer 13 in the absorbent core 40 is not particularly limited, and may be unevenly distributed in a part of the absorbent core 40 as in the present embodiment, and is uniformly distributed throughout the absorbent core 40. You may.

Next, the method for producing the absorbent article according to the present invention will be described by exemplifying the embodiments shown in FIGS. 1 and 2 described above.
The absorbent core 40 included in the napkin 1 can be manufactured according to a conventional method using a known fiber stacking device equipped with a rotating drum. The fiber stacking device typically conveys a rotary drum having an accumulation recess formed on the outer peripheral surface, and a core forming material (fiber mass 11, water-absorbent fiber 12F, water-absorbent polymer 13) in the accumulation recess. It is provided with a duct having a flow path inside, and while rotating the rotating drum around a rotation axis along the circumferential direction of the drum, it rides on an air flow generated in the flow path by suction from the inside of the rotating drum. The core-forming material conveyed in the above-mentioned structure is made to be stacked in the accumulation recess. The fiber stack formed in the accumulation recess by the fiber stacking process is the absorbent core 40. The specific arrangement of the core forming material in the absorbent core 40 described above can be realized by appropriately adjusting the fiber stacking order of each core forming material on the rotating drum in the manufacturing method using the fiber stacking device. .. The basis weight of the absorbent core 40 is preferably 100 g / m ² or more, more preferably 200 g / m ² or more, and preferably 800 g / m ² or less, more preferably 600 g / m ² or less.

The absorber 4 can be produced by the following two methods using a known fiber stacking device.
1) A method of stacking and integrating a fiber stack manufactured by one fiber stacking device and a fiber stacking body manufactured by the other fiber stacking device using two fiber stacking devices (hereinafter, "first". Also called "manufacturing method").
2) A method of using one fiber stacking device to make the timing of supplying the fiber mass to the recess for accumulation different from that of the water-absorbent polymer and the water-absorbent fiber (hereinafter, also referred to as "second manufacturing method"). ..

In the first manufacturing method, first, a water-absorbent fiber and a water-absorbent polymer are used as a core forming material, and these water-absorbent materials are accumulated in a recess for accumulation of the first fiber stacking device to accumulate the water-absorbent material. Manufacture the body. Separately from this, the fiber mass is accumulated in the accumulation recess of the second fiber stacking device to manufacture the fiber mass stacking fiber. Next, the fiber mass-stacked fiber is superposed on the surface side of the water-absorbent material stack on which the water-absorbent polymer is arranged, and the fiber mass stack is pressed in the thickness direction to obtain the water-absorbent material stack and the fiber mass stack. To obtain a laminated body. Alternatively, using a suction means such as a known vacuum conveyor, the water-absorbent material stacking fiber is placed on the suction surface of the suction means, and the suction force of the suction surface is acting on the water-absorbent material stacking fiber. The fiber mass stacking fiber body may be laminated and integrated on the surface on which the water-absorbent polymer is arranged in the body to obtain a laminated body.

In the second manufacturing method, one fiber stacking device is used. In the present manufacturing method, the fiber stacking device is operated, the rotating drum is rotated in the circumferential direction to convey the accumulation recess in one direction, and the accumulation is performed from the outside of the rotating drum by suction from the inside of the rotating drum. An air flow toward the concave portion is generated, and the core forming material is supplied to the concave portion for accumulation by the air flow and accumulated (accumulation step). In the accumulation step, first, the fiber mass 11 is supplied to the accumulation recess and accumulated. As a result, a fiber mass stacking fiber body is formed. Next, after or during the accumulation of such fiber lumps, the water-absorbent polymer 13 is supplied and accumulated, and then the water-absorbent fiber 12F is supplied to the accumulation recess and accumulated. Since the fiber mass 11 has air permeability, even when the fiber mass is accumulated in the accumulation recess, the suction force capable of sucking the water-absorbent polymer and the water-absorbent fiber on the accumulated fiber mass 11 is possible. Is acting, and the water-absorbent polymer 13 and the water-absorbent fiber 12F can be stacked and accumulated on the fiber mass 11 accumulated in the accumulation recess. In this way, the fiber mass stacking fiber, the water-absorbing polymer fiber stacking body, and the water-absorbing fiber stacking fiber laminate are formed in the accumulation recesses. In this way, the absorbent core 40 is obtained.

Hereinafter, the fiber mass 11 will be further described. FIG. 3 shows two typical outer shapes of the fiber mass 11. The fiber mass 11A shown in FIG. 3A has a quadrangular prism shape, more specifically a rectangular parallelepiped shape. The fiber mass 11B shown in FIG. 3B has a disk shape. The fiber lumps 11A and 11B are common in that they have two base planes 111 facing each other and a skeleton plane 112 connecting the two base planes 111. Both the basic surface 111 and the skeleton surface 112 are at a level applied when evaluating the degree of surface unevenness in an article mainly composed of this type of fiber, and are portions where it is recognized that there is substantially no unevenness.

The rectangular parallelepiped-shaped fiber mass 11A in FIG. 3A has six flat surfaces, of which two facing surfaces having the maximum area are the basic surfaces 111, and the rest. Each of the four surfaces is a skeletal surface 112. The basic surface 111 and the skeleton surface 112 intersect each other, and more specifically, are orthogonal to each other.
The disk-shaped fiber mass 11B of FIG. 3B has two flat surfaces facing each other in a circular shape in a plan view and a curved peripheral surface connecting the two flat surfaces, where the two flat surfaces are formed. Each surface is a basic surface 111, and the peripheral surface is a skeleton surface 112.
The fiber lumps 11A and 11B are also common in that the skeleton surface 112 has a quadrangular shape, more specifically, a rectangular shape in a plan view.

The plurality of fiber lumps 11 contained in the absorbent core 40 each have two opposing basic surfaces 111 and a skeleton surface 112 connecting both basic surfaces 111, such as the fiber lumps 11A and 11B shown in FIG. It differs from the above-mentioned amorphous fiber aggregate in that it is a provided "standard fiber aggregate". In other words, when any one fiber mass 11 in the absorbent core 40 is seen through (for example, when observed with an electron microscope), the fluoroscopic shape of the fiber mass 11 depends on the observation angle, and one fiber. Where there are a large number of perspective shapes per mass 11, each of the plurality of fiber masses 11 in the absorbent core 40 connects two opposing basic surfaces 111 and both basic surfaces 111 as one of the many perspective shapes. It has a specific perspective shape with a skeletal surface 112. The amorphous fiber aggregate does not substantially have a "plane" such as a basic surface 111 or a skeleton surface 112, that is, a widened portion, and is not a "standard" because the outer shapes are different from each other.

As described above, if the plurality of fiber lumps 11 contained in the absorbent core 40 are "standard fiber aggregates" defined by the basic surface 111 and the skeleton surface 112, the irregular fiber aggregates are considered. Since the uniform dispersibility of the fiber mass 11 in the absorbent core 40 is improved as compared with the case of the above, the expected effect (absorbent body) by blending the fiber aggregate such as the fiber mass 11 in the absorbent core 40. (Improvement effects such as flexibility, cushioning property, compression recovery property, etc.) will be exhibited more stably. Further, in particular, in the case of the rectangular parallelepiped fiber mass 11 as shown in FIG. 3A, since the outer surface thereof is composed of six surfaces of two basic surfaces 111 and four skeleton surfaces 112, the other fiber mass 11 or water absorption. It is possible to have a relatively large number of contact opportunities with the sex fiber 12F, the entanglement is enhanced, and the shape retention and the like can be improved.

In the fiber mass 11, the total area of the two basic surfaces 111 is preferably larger than the total area of the skeleton surface 112. That is, in the rectangular parallelepiped fiber mass 11A of FIG. 3 (a), the total area of each of the two basic surfaces 111 is larger than the total area of each of the four skeleton surfaces 112, and FIG. 3 (b). In the disk-shaped fiber mass 11B, the total area of each of the two basic surfaces 111 is larger than the area of the skeleton surface 112 forming the peripheral surface of the disk-shaped fiber mass 11B. In any of the fiber lumps 11A and 11B, the basic surface 111 is the surface having the largest area among the plurality of surfaces of the fiber lumps 11A and 11B.

As shown in FIG. 4, a method for manufacturing a fiber mass 11 which is a “standard fiber aggregate” defined by two basic surfaces 111 and a skeleton surface 112 intersecting both basic surfaces 111 is as shown in FIG. It has a step of cutting a raw material fiber sheet 10bs as a raw material into a fixed form by using a cutting means such as a cutter. The raw material fiber sheet 10bs is a sheet having the same composition as the fiber lump 11 and having a larger size than the fiber lump 11, and is preferably a non-woven fabric. The plurality of fiber lumps 11 produced through such steps have a more fixed shape and dimensions as compared with the amorphous fiber aggregate. FIG. 4 is a diagram illustrating a method for manufacturing the rectangular parallelepiped-shaped fiber mass 11A shown in FIG. 3A, and the dotted line in FIG. 4 indicates a cutting line. The absorbent core 40 contains a plurality of fiber lumps 11 having uniform shapes and dimensions obtained by cutting the fiber sheet into a fixed shape.

In the rectangular body-shaped fiber mass 11A of FIG. 3A, as shown in FIG. 4, the raw material fiber sheet 10bs is crossed (more specifically, orthogonally) with the first direction D1 and the first direction D1 in the second direction. Manufactured by cutting into D2 to a predetermined length. Both directions D1 and D2 are each a predetermined direction in the plane direction of the sheet 10bs, and the sheet 10bs is cut along the thickness direction Z orthogonal to the plane direction. As described above, in the plurality of rectangular parallelepiped fiber lumps 11A obtained by cutting the raw material fiber sheet 10bs into a so-called sword pattern, the cut surface, that is, the surface that comes into contact with a cutting means such as a cutter when the sheet 10bs is cut is usually formed. The skeleton surface 112, that is, the non-cut surface, that is, the surface that does not come into contact with the cutting means, is the basic surface 111. The basic surface 111 is a front and back surface (a surface orthogonal to the thickness direction Z) of the sheet 10bs, and as described above, is the surface having the largest area among the plurality of surfaces of the fiber mass 11A.

The above description of the fiber mass 11A basically applies to the disk-shaped fiber mass 11B of FIG. 3 (b). The only substantial difference from the fiber mass 11A is the cutting pattern of the raw material fiber sheet 10bs, and when the sheet 10bs is cut into a fixed shape to obtain the fiber mass 11B, the shape of the fiber mass 11B is matched to the plan view shape. The sheet 10bs may be cut into a circular shape.

Further, the outer shape of the fiber mass 11 is not limited to that shown in FIG. 3, and the basic surface 111 and the skeleton surface 112 are both flat surfaces that are not curved as in the

surfaces

111 and 112 of FIG. 3A. Alternatively, it may be a curved surface such as the skeleton surface 112 (peripheral surface of the disk-shaped fiber mass 11B) in FIG. 3 (b). Further, the basic surface 111 and the skeleton surface 112 may have the same shape and dimensions, and specifically, for example, the outer shape of the fiber mass 11A may be a cubic shape.

The size of the fiber mass 11 is not particularly limited, and can be appropriately set in consideration of the cushioning property, the liquid permeability, and the like of the absorbent core 40. The area of the basic surface 111, which has the largest area among the plurality of surfaces of the fiber mass 11, can be an index of the size of the fiber mass 11. The area of the basic surface 111 of the fiber mass 11 is preferably 1 mm ² or more, more preferably 5 mm ² or more, and preferably 100 mm ² or less, more preferably 50 mm ² or less.

As the preferable fiber mass 11, the aspect ratio of the basic surface 111 is 0.5 or more and 1.5 or less, and particularly preferably the aspect ratio is 1 or close to 1 (specifically, 1 ± 0.1). Examples of the aspect ratio having an aspect ratio of 1 or a value close to 1 include a square shape of the basic surface 111 in a plan view or a shape similar thereto. When such a fiber mass 11 is used for the absorbent core 40, the absorbent core 40 tends to be bulky, and the cushioning property and the like can be improved.

The aspect ratio of the basic surface 111 is obtained as the ratio of the lengths of the two sides orthogonal to each other defining the basic surface 111 of the quadrangle when the plan view shape of the basic surface 111 is a quadrangle. If the lengths of the two sides are the same, the aspect ratio of the basic surface 111 of the rectangular shape in plan view is 1, and if the lengths of the two sides are different from each other, that is, the shape in plan view of the basic surface 111 is shown in FIG. 3 (a). ), It is obtained as the ratio (L12 / L11) of the length L12 of the long side 111b to the length L11 of the short side 111a. Further, when the plan view shape of the basic surface 111 is not a quadrangle as in the fiber mass 11B shown in FIG. 3 (b), the lengths of the two axes orthogonal to each other through the center (center of gravity) of the basic surface 111. It is calculated as the ratio of. If the lengths of the two axes are the same, the aspect ratio of the basic surface 111 of the non-square shape in plan view is 1, and if the lengths of the two axes are different from each other, that is, the lengths are relatively short. When there is a short axis and a long axis having a relatively long length, the ratio of the length of the long axis (the length indicated by the reference numeral L12 in FIG. 3B) to the length of the short axis (the latter / the former). ).

The dimensions and the like of each part of the fiber mass 11 (11A, 11B) can be set as follows, for example. The dimensions of each part of the fiber mass 11 can be measured based on an electron micrograph of the fiber mass 11 or the like.
When the basic surface 111 has a rectangular shape in a plan view as shown in FIG. 3A, the length L11 of the short side 111a is preferably 0.1 mm or more, more preferably 0.3 mm or more, still more preferably 0.5 mm. The above, preferably 10 mm or less, more preferably 6 mm or less, still more preferably 5 mm or less.
The length L12 of the long side 111b of the basic surface 111 having a rectangular shape in a plan view is preferably 0.3 mm or more, more preferably 1 mm or more, still more preferably 2 mm or more, and preferably 30 mm or less, more preferably 15 mm or less. More preferably, it is 10 mm or less.
As shown in FIG. 3, when the basic surface 111 is the surface having the maximum area among the plurality of surfaces of the fiber mass 11, the length L12 of the long side 111b is the maximum transfer length of the fiber mass 11. It corresponds to (the length of the long axis), and the maximum transfer length corresponds to the diameter of the basic surface 111 having a circular shape in a plan view in the disk-shaped fiber mass 11B.
The thickness T of the fiber mass 11, that is, the length T between the two opposing basic surfaces 111 is preferably 0.1 mm or more, more preferably 0.3 mm or more, and preferably 10 mm or less, more preferably 6 mm or less. be.

As described above, the two types of surfaces (basic surface 111 and skeleton surface 112) of the fiber mass 11 (11A, 11B) are used to cut the raw material fiber sheet 10bs by a cutting means such as a cutter when manufacturing the fiber mass 11. It is classified into a cut surface (skeleton surface 112) formed by the sheet 10bs and a non-cut surface (basic surface 111) that is inherently possessed by the sheet 10bs and does not come into contact with the cutting means. Due to the difference in whether or not the cut surface is used, the cut surface, the skeleton surface 112, is characterized in that the number of fiber ends per unit area is larger than that of the non-cut surface, the basic surface 111. Has. The term "fiber end" as used herein means the end in the length direction of the constituent fibers 11F of the fiber mass 11. Normally, the fiber end is also present on the basic surface 111, which is a non-cut surface, but the skeleton surface 112 is formed by cutting because it is a cut surface formed by cutting the raw material fiber sheet 10bs. A large number of fiber ends consisting of cut ends of the constituent fibers 11F are present in the entire skeleton surface 112, that is, the number of fiber ends per unit area is larger than that of the basic surface 111. ..

At the fiber ends existing on each surface (basic surface 111, skeleton surface 112) of the fiber mass 11, the fiber mass 11 is between the other fiber mass 11 included in the absorbent core 40 and the water-absorbent fiber 12F. Useful for forming confounding. Further, in general, the larger the number of fiber ends per unit area, the better the entanglement, which may lead to the improvement of various characteristics such as the shape retention of the absorbent core 40. As described above, the number of fiber ends per unit area on each surface of the fiber mass 11 is not uniform, and the number of such fiber ends per unit area is "skeleton surface 112> basic surface 111". Since the magnitude relationship is established, the entanglement with other fibers (other fiber mass 11, water-absorbent fiber 12F) via the fiber mass 11 differs depending on the surface of the fiber mass 11, and the skeleton surface 112 is the basic surface 111. Highly entangled compared to. That is, the bond by entanglement with other fibers via the skeleton surface 112 has a stronger bonding force than that through the basic surface 111, and in one fiber mass 11, the basic surface 111 and the skeleton surface There may be a difference in the bonding force with other fibers from 112. In general, the stronger the bonding force, the more the degree of freedom of movement of the bonded fibers is limited, and the strength (shape retention) of the absorbent core 40 as a whole is improved, but the softness tends to be decreased. ..

As described above, in the absorbent core 40, each of the plurality of fiber lumps 11 contained therein has two types of binding forces with respect to other fibers (other fiber lumps 11, water-absorbent fiber 12F) around the absorbent core 40. The absorbent core 40 has an appropriate softness and strength (shape retention). When the absorbent core 40 having such excellent properties is used as an absorber of the absorbent article according to a conventional method, it is possible to provide a comfortable wearing feeling to the wearer of the absorbent article. At the same time, the inconvenience that the absorbent core 40 is destroyed by an external force such as the wearer's body pressure at the time of wearing is effectively prevented.

In particular, in the fiber mass 11 (11A, 11B) shown in FIG. 3, the total area of the two basic surfaces 111 is larger than the total area of the skeleton surface 112, as described above. Therefore, the basic surface 111, which has a relatively small number of fiber ends per unit area and therefore has a relatively low entanglement with other fibers, has a skeleton surface 112 having the opposite property. It means that the total area is larger than that. Therefore, the fiber lumps 11 (11A, 11B) shown in FIG. 3 have other fibers (other fiber lumps 11, water-absorbent fibers 12F) in the vicinity as compared with the fiber lumps having fiber ends uniformly present on the entire surface. ) Is easily suppressed, and even if it is entangled with other fibers in the vicinity, it is easy to be entangled with a relatively weak binding force. Can impart sex.

The constituent fibers 11F of the fiber mass 11 include synthetic fibers such as thermoplastic fibers. It is preferable to use a thermoplastic fiber as the fiber 11F. Such thermoplastic fibers preferably have lower water absorption (weak water absorption) than the water-absorbent fibers 12F, and particularly preferably non-water-absorbent thermoplastic fibers. The constituent fiber 11F of the fiber mass 11 may contain a fiber component other than the thermoplastic fiber (for example, a natural fiber), but the constituent fiber 11F of the fiber mass 11 contains a weakly hydrophilic fiber, preferably a non-water-absorbing fiber. Not only when the absorbent core 40 is in a dry state, but also when it is in a wet state by absorbing water (body fluid such as urine and menstrual blood), the action and effect (shape retention, shape retention, due to the presence of the fiber mass 11) (Improvement effects such as flexibility, cushioning, compression recovery, and resistance to twisting) will be stably achieved.
The content of the synthetic fiber as the constituent fiber 11F in the fiber mass 11 is preferably 90% by mass or more with respect to the total mass of the fiber mass 11, and 100% by mass, that is, the fiber mass 11 is formed only from the synthetic fiber. Most preferably. In particular, when the constituent fiber 11F contains a thermoplastic fiber, the action and effect caused by the presence of the fiber mass 11 described above are more stably exhibited.

When a thermoplastic fiber is used as the fiber 11F, the thermoplastic fiber preferably has a low water absorption.
As used herein, the term "water-absorbent" is readily understood by those of skill in the art, for example, pulp is water-absorbent. Similarly, it can be easily understood that thermoplastic fibers are weakly absorbent (particularly non-absorbent). On the other hand, the degree of water absorption of the fiber can be compared with the relative difference in water absorption by the value of the water content measured by the following method, and a more preferable range can be defined. The larger the value of the water content, the stronger the water absorption of the fiber. The water-absorbent fiber 12F preferably has such a water content of 6% or more, more preferably 10% or more. On the other hand, the thermoplastic fiber preferably has such a moisture content of less than 6%, more preferably less than 4%. When the water content is less than 6%, the fiber can be determined to be a non-water-absorbent fiber.

<Measurement method of moisture content>
The water content was calculated by applying the water content test method of JIS P8203 mutatis mutandis. That is, after the fiber sample was allowed to stand in a test room having a temperature of 40 ° C. and a relative humidity of 80% RH for 24 hours, the weight W (g) of the fiber sample before the absolute drying treatment was measured in the room. Then, it was allowed to stand in an electric dryer having a temperature of 105 ± 2 ° C. (for example, manufactured by Isuzu Seisakusho Co., Ltd.) for 1 hour to perform an absolute drying treatment of the fiber sample. After the absolute drying treatment, Si silica gel (for example, Si silica gel (for example,)) is used in a standard laboratory with a temperature of 20 ± 2 ° C. and a relative temperature of 65 ± 2%, and the fiber sample is covered with Saran Wrap (registered trademark) manufactured by Asahi Kasei Corporation. Toyoda Kako Co., Ltd. is placed in a glass desigator (for example, manufactured by Tech Jam Co., Ltd.) and allowed to stand until the temperature of the fiber sample reaches 20 ± 2 ° C. Then, the constant amount W'(g) of the fiber sample is weighed, and the water content of the fiber sample is obtained by the following formula. Moisture content (%) = (W-W'/ W') x 100

Similarly, from the viewpoint of enabling the absorbent core 40 to exhibit excellent effects in shape retention, flexibility, cushioning property, compression recovery property, resistance to twisting, etc. in both dry and wet states. , The fiber mass 11 preferably has a three-dimensional structure in which a plurality of thermoplastic fibers are heat-fused together.

In order to obtain a fiber mass 11 in which a plurality of heat-sealed portions are three-dimensionally dispersed, the raw material fiber sheets 10bs (see FIG. 4) may be similarly configured, and such a plurality of heats may be obtained. As described above, the raw material fiber sheet 10bs in which the fused portions are three-dimensionally dispersed can be manufactured by subjecting a web or a non-woven fabric mainly composed of thermoplastic fibers to a heat treatment such as hot air treatment.

The resin constituting the synthetic fiber is preferably a thermoplastic resin. Examples of the thermoplastic resin include polyolefins such as polyethylene and polypropylene; polyesters such as polyethylene terephthalate; polyamides such as nylon 6 and nylon 66; polyacrylic acid, polymethacrylic acid alkyl esters, polyvinyl chloride, polyvinylidene chloride and the like. One of these can be used alone or in combination of two or more. The fiber 11F may be a single fiber made of one kind of synthetic resin or a blended polymer in which two or more kinds of synthetic resins are mixed, or may be a composite fiber. The composite fiber referred to here is a synthetic fiber obtained by combining two or more kinds of synthetic resins having different components with a spinneret and spinning them at the same time, and has a structure in which a plurality of components are continuous in the length direction of the fiber. It means those that are mutually bonded in the fiber. The form of the composite fiber includes a core sheath type, a side-by-side type, and the like, and is not particularly limited.

Further, it is preferable that the contact angle of the fiber mass 11 with water is less than 90 degrees, particularly 70 degrees or less, from the viewpoint of further improving the drawability of body fluid in the initial excretion. Such fibers can be obtained by treating the above-mentioned non-water-absorbent thermoplastic fibers with a hydrophilic agent according to a conventional method. As the hydrophilizing agent, an ordinary surfactant can be used.

<Measurement method of contact angle>
The fiber is taken out from the measurement target (absorbent core), and the contact angle of water with respect to the fiber is measured. As a measuring device, an automatic contact angle meter MCA-J manufactured by Kyowa Interface Science Co., Ltd. is used. Deionized water is used to measure the contact angle. The amount of liquid discharged from the inkjet water droplet discharge unit (Pulse injector CTC-25 manufactured by Cluster Technology Co., Ltd., having a discharge unit hole diameter of 25 μm) is set to 20 picolitres, and the water droplet is dropped directly above the fiber. The state of dripping is recorded on a high-speed recording device connected to a horizontally installed camera. From the viewpoint of image analysis later, the recording device is preferably a personal computer incorporating a high-speed capture device. In this measurement, an image is recorded every 17 msec. In the recorded video, the first image of water droplets on the fibers is the attached software FAMAS (software version is 2.6.2, analysis method is droplet method, analysis method is θ / 2, image processing algorithm. Is non-reflective, the image processing image mode is frame, the threshold level is 200, and the curvature is not corrected.) Make a corner. The fiber taken out from the object to be measured is cut into a fiber length of 1 mm, and the fiber is placed on a sample table of a contact angle meter and maintained horizontally. Measure the contact angles at two different points for each fiber. N = 5 contact angles are measured up to one digit after the decimal point, and the average value of the measured values at 10 points in total (rounded to the second digit after the decimal point) is defined as the contact angle of the fiber with water. The measurement environment is room temperature 22 ± 2 ° C. and humidity 65 ± 2% RH.

Regarding the absorber (absorbent core) to be measured, when the absorber is taken out from the absorbent article, if the absorber is fixed to another component by an adhesive, fusion, etc., The fixed portion is taken out after removing the adhesive force by a method such as blowing cold air of a cold spray within a range that does not affect the contact angle of the fiber. This procedure is common to all measurements herein.

Next, the material for forming the elastic sheet according to the present invention will be described in detail. Examples of the elastic sheet include a sheet made of a film, a sheet provided with a non-woven fabric, and the like.
As the sheet made of a film, a film made of the same elastic resin as the elastic fiber described later can be used.

The sheet provided with the non-woven fabric includes, for example, (1) a stretchable non-woven fabric in which an expandable fiber layer is integrated on both sides or one side of an elastic fiber layer, and (2) a net-shaped elastic sheet that can be stretched on both sides or one side. Elastic non-woven fabric with integrated fiber layers, (3) Elastic non-woven fabric with elastic fibers integrated on both sides or one side of an elastic sheet made of elastic film, (4) without crossing each other A stretchable nonwoven fabric or the like in which a large number of elastic filaments arranged so as to extend in one direction are integrated with an stretchable fiber layer can be preferably used.
The "extensible fiber layer" referred to here is defined as a fiber layer that can be stretched before being integrated with an elastic material, and can be stretched by machining or the like after being integrated with an elastic material. Includes a fibrous layer.
As a method of integrating the elastic fiber layer and the stretchable fiber layer, for example, a method of laminating them and entwining the fibers by water flow entanglement or air through, a method of joining by heat embossing, an adhesive, ultrasonic waves or the like. Can be mentioned. As the elastic fiber, a fiber made of an elastic resin such as a styrene elastomer, a polyolefin elastomer, a thermoplastic elastomer such as a polyester elastomer or a polyurethane elastomer, or a rubber can be used. Further, as the inelastic fiber, a fiber made of a thermoplastic resin as a raw material can be used.

Examples of the stretchable non-woven fabric of (4) include those having a structure in which thread-like elastic filaments are sandwiched between stretchable fiber layers mainly composed of non-elastic fibers and integrated. Such a stretchable nonwoven fabric is configured to include two fiber sheets as a fiber layer and elastic filaments interposed between the two sheets. This stretchable nonwoven fabric can be produced, for example, according to the method described in JP-A-2009-61743.

In the stretchable nonwoven fabric of (4) above, both of the two fiber sheets are stretchable. The two fiber sheets can be extended in the same direction as the elastic filament extends. The extensible form includes the above-mentioned morphology (a) and morphology (b). Examples of the machining in (b) include heat treatment, inter-roll stretching, biting stretching with tooth grooves and gears, and tensile stretching with a tenter.

In the stretchable nonwoven fabric of (4) above, the elastic filament can be formed by being stretched in a state where the elastic resin is melted or softened. Each of the plurality of elastic filaments is continuously arranged in one direction and is arranged so as to extend in the one direction without intersecting with each other. The elastic filament is joined to the two fiber sheets in a substantially non-stretched state. This bonding is performed by fusing the constituent fibers (non-elastic fibers) of the two fiber sheets to the elastic filament in a state of being embedded in the elastic filament, and an adhesive such as a hot melt adhesive is used. It was not made using. Therefore, there is no adhesive between the two fiber sheets (extensible fiber layers mainly composed of inelastic fibers) and the elastic filaments bonded thereto.

The two fiber sheets constituting the stretchable non-woven fabric of (4) can be various non-woven fabrics such as air-through non-woven fabric, heat roll non-woven fabric, spunlace non-woven fabric, spunbond non-woven fabric, and melt blown non-woven fabric, respectively. The two fiber sheets may be of the same type or different from each other. The term "same type of sheet" as used herein means sheets having the same sheet manufacturing process, type of sheet constituent fibers, fiber diameter and length of constituent fibers, sheet thickness, basis weight, etc. .. If at least one of these is different, it is a "heterogeneous sheet". Further, the elastic filament is made of, for example, a thermoplastic elastomer, rubber, or the like as a raw material. In particular, when a thermoplastic elastomer is used as a raw material, melt spinning using an extruder is possible as in the case of a normal thermoplastic resin, and the elastic filament thus obtained is easily heat-sealed and therefore stretchable. Suitable for non-woven fabrics.

Although the present invention has been described above based on the embodiment, the present invention can be appropriately modified without being limited to the embodiment.
The absorbent article of the present invention broadly includes articles used for absorbing body fluids (urine, loose stool, menstrual blood, sweat, etc.) discharged from the human body, and in addition to the above-mentioned menstrual napkins, sanitary shorts and fastenings. So-called deployable disposable diapers with tape, pants-type disposable diapers, incontinence pads and the like are included.

Further, the following absorbent articles are disclosed with respect to the above-described embodiment of the present invention.
<1>
It has a vertical direction corresponding to the front-back direction of the wearer and a horizontal direction orthogonal to the vertical direction, and is provided with a liquid-permeable front sheet, a liquid-impermeable back sheet, and an absorber arranged between these two sheets. An absorbent article with an absorbent body,
On both sides of the absorbent body, side flaps made of a sheet extending outward from the side edges of the absorber along the vertical direction are provided.
The side flap portion is configured to include a stretchable sheet, and the stretch recovery rate of the stretchable sheet when stretched by 30% is 50% or more.
The absorber contains a plurality of fiber lumps including a water-absorbent fiber, a water-absorbent polymer and a synthetic fiber, and the plurality of fiber lumps or the fiber lump and the water-absorbent fiber are entangled with each other. Goods.

<2>
The side flap portion has a skin surface sheet having portions overlapping with both side portions along the vertical direction of the surface sheet, and a non-skin surface sheet forming a non-skin facing surface of the side flap portion, and the skin. The face sheet and the non-skin face sheet are bonded with an adhesive, and the surface sheet is bonded with an adhesive.
Both the skin surface sheet and the non-skin surface sheet are the stretchable sheets having elasticity in the vertical direction, the tensile load at the time of 30% elongation is 20 N or less, and the tensile load at the time of 30% elongation. The absorbent article according to <1>, wherein the difference between the two is 5 N or less.
<3>
The absorbent article according to <2>, wherein each of the skin surface sheet and the non-skin surface sheet has a tensile load of 0.1 N or more and 20 N or less when stretched by 30%.
<4>
The absorbent article according to <2>, wherein the skin surface sheet and the non-skin surface sheet each have a tensile load of 1 N or more and 15 N or less when stretched by 30%.
<5>
The absorbent article is a napkin for sports use,
The absorbent article according to <2>, wherein the skin surface sheet and the non-skin surface sheet, whichever has a larger tensile load at the time of 30% elongation, has a tensile load of 3 N or more and 20 N or less.
<6>
The absorbency according to any one of <2> to <5>, wherein the skin surface sheet and the non-skin surface sheet have a difference in tensile load of 0.01 N or more and 4.8 N or less when stretched by 30%. Goods.
<7>
The non-skin surface sheet has a portion located on the non-skin facing surface side of the absorber, and any of the above <2> to <6> is made so as not to exhibit elasticity in the portion. The absorbent article according to 1.
<8>
The absorbent article according to any one of <1> to <7>, wherein the surface sheet also has elasticity.
<9>
The side flap portion includes a stretchable sheet and a non-stretchable sheet, and the non-stretchable sheet can be stretched as the stretchable sheet is stretched at 30% stretch. > The absorbent article.
<10>
The side flap portion has a skin surface sheet having portions overlapping with both side portions along the vertical direction of the surface sheet, and a non-skin surface sheet forming a non-skin facing surface of the side flap portion.
The above-mentioned <1> to <9>, wherein the skin surface sheet and the non-skin surface sheet are joined by a hot melt adhesive coated with a pattern having a non-coated portion. Absorbent article.

<11>
The coating area of the hot melt adhesive (the coating area of the hot melt adhesive / the area of the side flap portion) with respect to the area of the side flap portion is 10% or more and 80% or less, according to the above <10>. Absorbent article.
<12>
The absorbent article according to any one of <1> to <11>, wherein the elastic sheet in the side flap portion has a 90 ° torsional torque value of 0.01 N cm or more and 1.0 N cm or less.
<13>
The region on the skin-facing surface side of the absorber has a fiber mass-containing mass ratio, which is the content-mass ratio of the fiber mass to the total mass of the water-absorbent fiber and the fiber mass, as compared with the region on the non-skin-facing surface side. The low absorbent article according to any one of <1> to <12>.
<14>
In the absorber, the difference (%) between the fiber mass content mass ratio (%) in the region on the non-skin facing surface side and the fiber mass content mass ratio (%) in the skin facing surface side region is 20% or more and 100% or less. The absorbent article according to <13> above.
<15>
The absorbent article according to <13>, wherein the region of the skin-facing surface of the absorber does not include the fiber mass.
<16>
The absorber according to any one of <1> to <15>, wherein the absorber includes a liquid-absorbing absorbent core and a liquid-permeable core wrap sheet that covers the outer surface of the absorbent core. Absorbent article.
<17>
The fiber mass is a fixed fiber aggregate defined by two opposing basic surfaces and a skeleton surface intersecting both basic surfaces, and the aspect ratio of the basic surfaces is 1 ± 0.1. The absorbent article according to any one of <1> to <16>.
<18>
The absorbent article according to any one of <1> to <17>, which is a menstrual napkin.

Hereinafter, the present invention will be described in more detail by way of examples. However, the scope of the invention is not limited to such examples.

[Example 1]
A napkin having the same basic configuration as that of the napkin 1 shown in FIGS. 1 and 2 was manufactured. The napkin had the same components as the sanitary napkin manufactured by Kao Corporation (trade name "Lorier Slim Guard, especially for daytime 25 cm") except for the absorber 4 and the side flap portion SF (back sheet 3).
The absorbent body 4 is a known fiber stacking device having an absorbent core 40 having a laminated structure in which a layer made of a water-absorbent fiber 12F, a layer made of a water-absorbent polymer 13, and a layer made of a fiber mass 11 are laminated in order from the skin facing surface. The absorbent core 40 was coated with a core wrap sheet 41. The basis weight of the water-absorbent fiber 12F in the absorber was 230 g / m ² , the basis weight of the water-absorbent polymer 13 was 50 g / m ² , and the basis weight of the fiber mass 11 was 140 g / m ² . The fiber mass 11 is formed by forming a raw material fiber sheet (raw material resin: core-sheath type composite fiber core part: polyethylene terephthalate / sheath part: polyethylene, fineness 2.4 dtex, basis weight 25 g / m ² , air-through non-woven fabric) in the shape of a sword (basic surface:). It was manufactured by cutting into 5 mm × 5 mm, thickness: 1.5 mm). In the obtained absorber 4, a plurality of adjacent fiber masses 11 were entangled with each other.
As the side flap portion SF, the skin surface sheet S1 was the following elastic sheet A, and the non-skin surface sheet S2 was the following elastic sheet B. These elastic sheets A and B show elasticity in the vertical direction X. Such a non-skin surface sheet S2 was composed of a back surface sheet 3 extending laterally outward from both side edges of the absorber 4 in the vertical direction X.
The stretchable sheet A is the stretchable non-woven fabric of the above (4), and is a spunbond made of an elastic filament (raw material resin styrene elastomer, basis weight 9 g / m ² ) and two fiber sheets whose raw material resin is polypropylene. It was a composite sheet (basis weight 45 g / m ² ) formed of a non-woven fabric (basis weight 18 g / m ² ). At the time of manufacturing the stretchable nonwoven fabric, these two fiber sheets were joined to an elastic filament and then bitten by a tooth groove roll so as to be stretchable.
The elastic sheet B was a sheet made of a film (raw material resin polyurethane, 30 g / m ² ).
The skin surface sheet S1 and the non-skin surface sheet S2 were joined by a hot melt adhesive coated in a spiral shape to form a side flap portion SF.

[Example 2]
A napkin was manufactured by the same method as in Example 1 except that the stretchable sheet A was used for the non-skin surface sheet S2 in the side flap portion SF.

[Comparative Example 1]
As the side flap portion SF, the skin surface sheet S1 was the following non-stretchable sheet C, and the non-skin surface sheet S2 was the following non-stretchable sheet D. Except for these points, napkins were produced by the same method as in Example 1. These non-stretchable sheets C and D did not show elasticity in a predetermined direction (the elongation recovery rate at the time of 30% elongation was less than 50%).
The non-stretchable sheet C was a spunbonded non-woven fabric (basis weight 20 g / m ² ) in which the raw material resin was polypropylene.
The non-stretchable sheet D was a film (basis weight 37 g / m ² ) in which the raw material resin was polyethylene.

[Comparative Example 2]
As the absorber 4, a fiber mass 11 was not contained, and the water-absorbent fiber 12F and the water-absorbent polymer 13 were uniformly distributed in the thickness direction of the absorber. The basis weight of the water-absorbent fiber 12F in the absorber was 400 g / m ² , and the basis weight of the water-absorbent polymer 13 was 50 g / m ² . Except for these points, a napkin was produced by the same method as in Comparative Example 1.

For each of the skin surface sheet S1 and the non-skin surface sheet S2 in each Example and each comparative example, the elongation recovery rate at 30% elongation, the tensile load at 30% elongation, and the 90 ° torsion torque value are measured by the above-mentioned methods. did. The measurement results are shown in Table 1 below.
In addition, the following dynamic maximum absorption amount, 60 ° torsional torque value, and mounting pressure amplitude were measured for the napkins in each example and each comparative example. The measurement results are shown in Table 1 below.

[Dynamic maximum absorption amount]
The napkin to be measured was fixed to sanitary shorts and attached to a dynamic model of the human body. As a dynamic model of the human body, a movable female lumbar model capable of walking and moving both legs was used. The walking motion of the dynamic model was started, and 1 g of pseudo blood was injected from the liquid excretion point 1 minute after the start of the walking motion (first time). Further, 10 minutes after the completion of the first liquid injection, 1 g of pseudo blood was injected. In this way, the operation of further injecting 1 g of pseudo blood is repeated 10 minutes after the injection of the pseudo blood, and the liquid injection operation is completed when the pseudo blood exudes from the side flap portion SF of the sanitary napkin. The total weight of the pseudo-blood injected up to that point was taken as the dynamic maximum absorption amount (g).
Pseudoblood has a viscosity of 8 mPa · s measured using a B-type viscometer (model number TVB-10M manufactured by Toki Sangyo Co., Ltd., measurement conditions: rotor No. 19, 30 rpm, 25 ° C, 60 seconds). , The blood cell / plasma ratio of defibered horse blood (manufactured by Japan Biotest Research Institute Co., Ltd.) was prepared and used. The larger the value of the dynamic maximum absorption amount, the less likely it is to leak when walking, and the higher the evaluation.

[60 ° torsion torque value]
The 60 ° torsional torque value of the napkin was measured using the torque tester in the above-mentioned [Measurement of 90 ° torsional torque value]. Specifically, both ends of the napkin in the longitudinal direction were sandwiched between the upper and lower clamps 20a and 20b, and the napkin was fixed between the upper and

lower clamps

20a and 20c [see FIG. 5A]. Next, the upper clamp is reciprocated by 60 ° in the forward and opposite directions (forward rotation and reverse rotation) with the vertical direction X of the napkin as the rotation axis [see FIGS. 5 (b) and 5 (c)], and the napkin is applied. The torsional moment value (torsional torque value) was measured. Such a measurement was performed on five sample pieces, and the average of the maximum values in the forward direction and the opposite direction in the measurement was taken as the 60 ° torsion torque value. The smaller the 60 ° torsion torque value, the higher the followability to the wearer's movement, and the higher the evaluation. The tension applied to the sample piece during rotation was measured in the range of 3 to 6N. The length between the clamps at the time of measurement was 175 mm under no tension.

[Amplitude of mounting pressure]
The napkin to be measured was fixed to the sanitary shorts and attached to the dynamic model of the human body used in the above [dynamic maximum absorption amount]. At this time, a small 3-axis force sensor (manufactured by Tech Gihan Co., Ltd., model number USL06-H5) is placed between the part facing the excretion part in the dynamic model and the napkin to measure the wearing pressure during walking. did. Since the wearing pressure changes periodically due to walking of the dynamic model, a graph of a periodic wave shape synchronized with the walking motion can be obtained. In this measurement, the wearing pressure was continuously measured from the start of the walking motion to 1 minute. The walking speed of the dynamic model was measured at 50 steps / minute. Then, based on the obtained wave shape graph of the mounting pressure, the average fluctuation difference of the mounting pressure due to the walking motion (also referred to as the amplitude of the mounting pressure) is obtained from the fluctuation difference obtained from the maximum mounting pressure and the minimum mounting pressure for each cycle. Asked. The smaller the amplitude of the wearing pressure, the higher the fit of the napkin to the body, and the higher the evaluation.

As shown in Table 1, the napkins of each example had lower 60 ° torsional torque values and mounting pressure amplitudes than the napkins of each comparative example. From this, it was shown that the napkins of each example were superior to the napkins of each comparative example in the ability to follow the movement of the wearer and the fit of the napkin to the body.
Further, from the comparison of the dynamic maximum absorption amount of Comparative Example 1 and Comparative Example 2, it was shown that the inclusion of the fiber mass in the absorber is effective in suppressing leakage during walking. It was shown that such a leak suppressing effect was also exhibited in Examples 1 and 2 containing fiber lumps.

According to the absorbent article of the present invention, it is excellent in followability to the movement of the wearer's body while maintaining the fit.

Claims

It has a vertical direction corresponding to the front-back direction of the wearer and a horizontal direction orthogonal to the vertical direction, and is provided with a liquid-permeable front sheet, a liquid-impermeable back sheet, and an absorber arranged between these two sheets. An absorbent article with an absorbent body,
On both sides of the absorbent body, side flaps made of a sheet extending outward from the side edges of the absorber along the vertical direction are provided.
The side flap portion is configured to include a stretchable sheet, and the stretch recovery rate of the stretchable sheet when stretched by 30% is 50% or more.
The absorber contains a plurality of fiber lumps including a water-absorbent fiber, a water-absorbent polymer, and a synthetic fiber, and the plurality of fiber lumps or the fiber lump and the water-absorbent fiber are entangled with each other. Sex goods.
The side flap portion has a skin surface sheet having portions overlapping with both side portions along the vertical direction of the surface sheet, and a non-skin surface sheet forming a non-skin facing surface of the side flap portion, and the skin. The face sheet and the non-skin face sheet are bonded with an adhesive, and the surface sheet is bonded with an adhesive.
Both the skin surface sheet and the non-skin surface sheet are the stretchable sheets having elasticity in the vertical direction, the tensile load at the time of 30% elongation is 20 N or less, and the tensile load at the time of 30% elongation. The absorbent article according to claim 1, wherein the difference between the two is 5 N or less.
The absorbent article according to claim 2, wherein each of the skin surface sheet and the non-skin surface sheet has a tensile load of 0.1 N or more and 20 N or less when stretched by 30%.
The absorbent article according to claim 2, wherein each of the skin surface sheet and the non-skin surface sheet has a tensile load of 1 N or more and 15 N or less when stretched by 30%.
The absorbent article is a napkin for sports use,
The absorbent article according to claim 2, wherein the skin surface sheet and the non-skin surface sheet, whichever has a larger tensile load at the time of 30% elongation, has a tensile load of 3 N or more and 20 N or less.
The absorbent article according to any one of claims 2 to 5, wherein the skin surface sheet and the non-skin surface sheet have a difference in tensile load of 0.01 N or more and 4.8 N or less at the time of 30% elongation.
The non-skin surface sheet has a portion located on the non-skin facing surface side of the absorber, and any one of claims 2 to 6 is made so as not to exhibit elasticity in the portion. Absorbent article described in.
The absorbent article according to any one of claims 1 to 7, wherein the surface sheet also has elasticity.
1. The side flap portion is configured to include an elastic sheet and a non-stretchable sheet, and the non-stretchable sheet can be stretched along with the elongation of the elastic sheet at the time of 30% elongation, claim 1. Absorbent article described in.
The side flap portion has a skin surface sheet having portions overlapping with both side portions along the vertical direction of the surface sheet, and a non-skin surface sheet forming a non-skin facing surface of the side flap portion.
The absorbency according to any one of claims 1 to 9, wherein the skin surface sheet and the non-skin surface sheet are joined by a hot melt adhesive coated with a pattern having a non-coated portion. Goods.
The absorbent article according to claim 10, wherein the coating area of the hot melt adhesive with respect to the area of the side flap portion is 10% or more and 80% or less.
The absorbent article according to any one of claims 1 to 11, wherein the elastic sheet in the side flap portion has a 90 ° torsional torque value of 0.01 N cm or more and 1.0 N cm or less.
The region on the skin-facing surface side of the absorber has a fiber mass-containing mass ratio, which is the content-mass ratio of the fiber mass to the total mass of the water-absorbent fiber and the fiber mass, as compared with the region on the non-skin-facing surface side. The low, absorbent article according to any one of claims 1-12.
The thirteenth aspect of the present invention, wherein the difference between the fiber mass-containing mass ratio in the region facing the skin and the fiber mass-containing mass ratio in the region facing the skin in the absorber is 20% or more and 100% or less. Absorbent article.
The absorbent article according to claim 13, wherein the region of the skin-facing surface of the absorber does not include the fiber mass.
The absorption according to any one of claims 1 to 15, wherein the absorber includes a liquid-absorbable absorbent core and a liquid-permeable core wrap sheet that covers the outer surface of the absorbent core. Sex goods.
The fiber mass is a fixed fiber aggregate defined by two opposing basic surfaces and a skeleton surface intersecting both basic surfaces, and the aspect ratio of the basic surfaces is 1 ± 0.1. The absorbent article according to any one of claims 1 to 16.
The absorbent article according to any one of claims 1 to 17, which is a menstrual napkin.