CN114206283A

CN114206283A - Functional sheet, absorbent article provided with same, and method for producing same

Info

Publication number: CN114206283A
Application number: CN202080056230.3A
Authority: CN
Inventors: 冈田友记; 古川勉
Original assignee: Daio Paper Corp
Current assignee: Daio Paper Corp
Priority date: 2019-09-26
Filing date: 2020-09-08
Publication date: 2022-03-18
Anticipated expiration: 2040-09-08
Also published as: TW202112329A; WO2021059957A1; JP2021052820A; CN114206283B; JP7159141B2

Abstract

The invention provides a functional sheet having improved flexibility without impairing the characteristics such as hygroscopicity of microfibrous cellulose as much as possible, an absorbent article provided with the functional sheet, and methods for producing the functional sheet and the absorbent article. The functional sheet of the present invention is characterized in that an aggregate of at least one of microfibrous cellulose containing a humectant and aggregated particles thereof is adhered to the sheet. Further, an absorbent article according to the present invention is characterized by comprising: a liquid-permeable top sheet (30) that covers the inner surface of the absorber (56); a liquid impermeable resin film (11) having moisture permeability and covering the outer surface of the absorber (56); and an outer-covering nonwoven fabric (12) having moisture permeability and covering the outer surface of the liquid-impermeable resin film, wherein at least one of the liquid-permeable top sheet (30), the liquid-impermeable resin film (11), and the outer-covering nonwoven fabric (12) is the functional sheet.

Description

Functional sheet, absorbent article provided with same, and method for producing same

Technical Field

The present invention relates to a disposable diaper such as a functional sheet, a pants-type diaper, a tape-type diaper, and an absorbent article such as a sanitary napkin, and a method for producing the same.

Background

In absorbent articles such as disposable diapers and sanitary napkins (patent documents 2 and 3), it has been proposed to apply an aqueous dispersion of microfibrous cellulose to a desired site and dry the applied aqueous dispersion in order to impart a function such as moisture absorption (see, for example, patent document 1).

However, when aggregated microfibrous cellulose particles obtained by drying an aqueous dispersion of microfibrous cellulose are hard and adhere to a sheet (such a sheet is often used in absorbent articles) that is flexible to some extent, such as a nonwoven fabric or a resin film, the adhered portion becomes hard, which is a problem.

Documents of the prior art

Patent document

Patent document 1: japanese patent No. 6442098

Patent document 2: japanese Kohyo publication No. 2005-504591

Patent document 3: japanese patent No. 6445732

Disclosure of Invention

Problems to be solved by the invention

Therefore, a main object of the present invention is to improve flexibility without impairing the characteristics such as hygroscopicity of the microfibrous cellulose as much as possible.

Means for solving the problems

The functional sheet and the absorbent article provided with the functional sheet, which solve the above problems, and the manufacturing methods thereof are as follows.

< embodiment 1 >

A functional sheet characterized by having an aggregate of at least one of microfibrous cellulose containing a humectant and aggregated particles thereof adhered to the sheet.

(Effect)

The functional sheet is characterized in that at least one of microfibrous cellulose and aggregated particles thereof is attached to the sheet as an aggregate that is not completely dried and solidified, using a humectant as a binder. The aggregate is in a wet state and is not easily dried, and thus is soft. In addition, since the microfibrous cellulose adheres to the sheet as an aggregate containing a humectant, the properties such as moisture absorption are not easily impaired.

< embodiment 2 >

The functional sheet according to claim 1, wherein the aggregate contains the microfibrous cellulose and the microfibrous cellulose aggregated particles in a total amount of 0.25 to 1.0 part by mass based on 1 part by mass of the humectant.

(Effect)

In the functional sheet, the ratio of the amount of the plasticizer to the amount of the microfibrous cellulose is appropriate in order to ensure the flexibility of the functional sheet. Moreover, a functional sheet comprising the aggregate in the above ratio is not substantially sticky.

< embodiment 3 >

An absorbent article, characterized by comprising:

a liquid-permeable top sheet covering the inner surface of the absorbent body;

a liquid impermeable resin film having moisture permeability covering the outer surface of the absorbent body; and

an outer-covering nonwoven fabric covering the outer surface of the liquid-impermeable resin film and having moisture permeability,

at least one of the liquid-permeable top sheet, the liquid-impermeable resin film, and the outer-cover nonwoven fabric is the functional sheet according to claim 1 or 2.

(Effect)

If the microfibrous cellulose is provided on a sheet having liquid permeability or moisture permeability, moisture emitted from an absorbent or the like that absorbs excretory fluid or the like is absorbed by the microfibrous cellulose. This promotes drying of the functional sheet constituting the absorbent article, and as a result, stuffiness is suppressed. Further, since the aggregate contains the humectant, the functional sheet (in this case, the functional sheet may be any of a top sheet, a liquid-impermeable resin film, and an outer-coated nonwoven fabric) has flexibility without becoming hard even if it has microfibrous cellulose.

< embodiment 4 >

The absorbent article according to claim 3, wherein,

the exterior nonwoven fabric is the functional sheet according to claim 1 or 2,

13.0g/m is provided on one surface of the functional sheet²The following aggregate of the above-mentioned substances,

the one surface is an outer surface of the exterior nonwoven fabric.

(Effect)

The coating amount of the aggregate was 13.0g/m²Hereinafter, even if the skin touches the outer cover of the product, no stickiness and no hardness are felt. The exterior nonwoven fabric has flexibility, and wrinkles (wrinkles described later) formed by providing conventional microfibrous cellulose are inconspicuous, and thus the exterior nonwoven fabric becomes an absorbent article having a natural texture.

In addition, in the conventional absorbent article, in order to prevent stuffiness, the high moisture permeability of the liquid impermeable resin film has been a serious problem, and moisture emitted from the excretory fluid absorbed in the absorbent body holds moisture on the outer surface of the product or underwear, and when touched with a hand, the product may be mistaken for being wet. This can be solved by reducing the moisture permeability of the liquid-impermeable resin film, but this cannot avoid a reduction in the stuffy heat resistance.

In this embodiment, the microfibrous cellulose is provided on the outer surface of the outer nonwoven fabric covering the outer package of the product. Moisture permeating the liquid-impermeable resin film is absorbed by the microfibrous cellulose. Therefore, the outer nonwoven fabric itself does not become wet, and the outer side of the product is hard to feel wet.

< embodiment 5 >

The absorbent article according to claim 3, wherein,

the exterior nonwoven fabric is the functional sheet according to claim 1 or 2,

the aggregate is provided on one surface of the functional sheet,

the one surface is an inner surface of the exterior nonwoven fabric.

(Effect)

When the coating amount of the aggregate is more than 13g/m²The outer nonwoven fabric may be sticky, but the wearer does not feel sticky because the inner surface of the outer nonwoven fabric is a portion that does not contact the skin. Further, if the aggregate is applied as much as possible, the amount of the microfibrous cellulose contained in the aggregate is large, and therefore, more moisture is absorbed.

< embodiment 6 >

The absorbent article according to any one of claims 3 to 5, wherein,

the liquid-permeable top sheet according to claim 1 or 2,

13.6g/m is provided on one surface of the functional sheet²The following aggregate of the above-mentioned substances,

the one surface is an inner surface of the liquid-permeable top sheet.

(Effect)

The inner surface of the topsheet is the portion that directly contacts between the thighs of the wearer, and preferably the wearer's skin is not irritated by stuffiness. As described above, the top sheet preferably has moisture absorption properties, but the top sheet disclosed in patent document 1 having cellulose fibers has hardness and poor texture.

In this embodiment, even when the microfibrous cellulose and aggregated particles thereof adhere to the top sheet, the top sheet has excellent flexibility because of the inclusion of the humectant. Furthermore, the microfibrillar cellulose absorbs moisture due to its hygroscopicity, and thus, it has an effect of suppressing stuffiness and making the skin portion in contact with the top sheet less likely to be inflamed.

< 7 th mode >

An absorbent article according to claim 6, wherein the aggregate provided on the inner surface of the moisture-permeable top sheet has linear portions continuous in the front-back direction and arranged in stripes at intervals in the width direction.

(Effect)

In a typical absorbent article, the excreta liquid passes through the top sheet in the direction of the absorbent body and is absorbed. However, when the wearer excretes in an oblique posture or the like, the excreted liquid may flow in the width direction of the top sheet, and leakage may occur. In this embodiment, the aggregates are arranged in a stripe shape in the front-rear direction at intervals in the width direction, and the moisture adsorption effect of the microfibrous cellulose makes it easy for the excretion liquid to diffuse in the front-rear direction in which the aggregates are arranged, and as a result, there is an effect that the flow of the excretion liquid in the width direction is suppressed.

< embodiment 8 >

A method for manufacturing an absorbent article, comprising the steps of:

a step of mixing the microfibrous cellulose dispersion with a humectant to obtain an aggregate;

coating the aggregate on a sheet to obtain a functional sheet; and

and a step of forming the functional sheet into at least one of a liquid-permeable top sheet, a liquid-impermeable resin film, and an outer-covering nonwoven fabric in an absorbent article having the liquid-permeable top sheet covering the inner surface of an absorbent body, the liquid-impermeable resin film covering the outer surface of the absorbent body and having moisture permeability, and the outer-covering nonwoven fabric covering the outer surface of the liquid-impermeable resin film and having moisture permeability.

(Effect)

The present invention has the operational effects of any one of the 3 rd to 7 th aspects.

Effects of the invention

According to the present invention, there are provided a functional sheet having improved flexibility without impairing the characteristics such as moisture absorption of microfibrous cellulose as much as possible, an absorbent article provided with the functional sheet, and methods for producing the functional sheet and the absorbent article.

Drawings

Fig. 1 is a plan view showing the inner surface of a tape-type disposable diaper in a state where the diaper is unfolded.

Fig. 2 is a plan view showing the outer surface of the tape-type disposable diaper in a state where the diaper is unfolded.

Fig. 3 is a cross-sectional view taken along line 6-6 of fig. 1.

Fig. 4 is a cross-sectional view taken along line 7-7 of fig. 1.

Fig. 5 is a cross-sectional view taken along line 8-8 of fig. 1.

Fig. 6 is a cross-sectional view taken along line 9-9 of fig. 1.

Fig. 7 is a cross-sectional view taken along line 5-5 of fig. 1.

Fig. 8 is an explanatory diagram showing the arrangement of the aggregated microfibrous cellulose particles.

Fig. 9 is an explanatory view showing another example of the application of the microfibrous cellulose.

Fig. 10 is an explanatory view showing another coating method of the microfibrous cellulose.

Fig. 11 is an explanatory view showing another coating method of the microfibrous cellulose.

Fig. 12 is a view of a nonwoven fabric coated with only microfibrous cellulose.

FIG. 13 is a view of a nonwoven fabric coated with an aggregate.

Fig. 14 is an explanatory view showing one embodiment of the coating pattern of the aggregate and the adhesive.

FIG. 15 is a schematic representation of a coacervate.

Fig. 16 is an explanatory view showing another mode of the coating pattern of the aggregate and the adhesive.

Detailed Description

Hereinafter, a tape-type disposable diaper will be described as an example of a specific embodiment. Fig. 1 to 7 show an example of a tape-type disposable diaper, in which the reference numeral X denotes the entire width of the diaper except for the connecting tape, the reference numeral L denotes the entire length of the diaper, and the respective constituent members in the sectional views are joined by an adhesive as joining means for joining. The adhesive is formed by full-surface application of a hot-melt adhesive, droplet (ビード) application, curtain application, critical portion (サミット) application or spiral application, pattern application (transfer of a hot-melt adhesive by a relief method), or the like, or the fixed portion of the elastic member is formed by applying the outer peripheral surface of the elastic member with an application gun, size application, or the like instead of or together with the adhesive. Examples of the hot melt adhesive include adhesives of EVA type, adhesive rubber type (elastic type), olefin type, polyester/polyamide type, and the like, and can be used without particular limitation. As a joining means for joining the respective components, a means based on fusion of raw materials such as heat sealing and ultrasonic sealing may be employed. The basis weight of the hot melt adhesive can be set to 1-40 g/m². By setting the range, the facing surfaces of the two adjacent components are strongly bonded to each other at the coating portion of the adhesive.

A tape-type disposable diaper comprises: an absorber 56; a liquid-permeable top sheet 30 covering the front side of the absorber 56; a liquid-impermeable resin film 11 that covers the outside of the absorbent body 56; and an outer-covering nonwoven fabric 12 which covers the outside of the liquid-impermeable resin film and constitutes the outer surface of the product. Reference numeral F denotes a ventral portion located more anteriorly than the anteroposterior direction center, and reference numeral B denotes a dorsal portion located more posteriorly than the anteroposterior direction center.

The materials and characteristics of each part will be described in turn below.

(absorber)

The absorber 56 is a part that absorbs and holds body fluid such as excretory fluid and blood, and may be formed of aggregated particles of fibers. The fiber aggregate particles are obtained by stacking short fibers such as cotton pulp and synthetic fibersIn addition to the fiber aggregate particles of (1), filament aggregate particles obtained by opening a tow (fiber bundle) of synthetic fibers such as cellulose acetate may be used as needed. The basis weight of the fibers may be, for example, 100 to 300g/m in the case of stacking cotton pulp or short fibers²The degree of (2) may be, for example, 30 to 120g/m in the case of filament aggregated particles²To the extent of (c). The fineness of the synthetic fiber is, for example, 1 to 16dtex, preferably 1 to 10 dtex. In the case of aggregated particles of filaments, the filaments may also be non-crimped fibers, but preferably crimped fibers. The crimp amount of the crimped fiber may be, for example, about 5 to 75, preferably about 10 to 50, and more preferably about 15 to 50 per 2.54 cm. In addition, uniformly crimped fibers may be used.

(superabsorbent polymer particles)

The absorbent body 56 may contain superabsorbent polymer particles in a part or all thereof. The super absorbent polymer particles include "powder" in addition to "particles". As the super absorbent polymer particles, super absorbent polymer particles used in such absorbent articles can be directly used. The particle size of the super absorbent polymer particles is not particularly limited, and for example, the following particle sizes are preferable: when the particles falling to the undersize by the sieving were sieved (5 minutes shaking) using a 500 μm standard sieve (JIS Z8801-1:2006), and the particles were sieved (5 minutes shaking) using a 180 μm standard sieve (JIS Z8801-1:2006), the proportion of the particles remaining on the 500 μm standard sieve was 30 wt% or less, and the proportion of the particles remaining on the 180 μm standard sieve was 60 wt% or more.

The material of the super absorbent polymer particles is not particularly limited, but is preferably a material having a water absorption capacity of 30g/g or more. As the super absorbent polymer particles, there are starch-based, cellulose-based, synthetic polymer-based and the like, and starch-acrylic acid (salt) graft copolymer, saponified product of starch-acrylonitrile copolymer, crosslinked product of sodium carboxymethylcellulose, acrylic acid (salt) polymer and the like can be used. The shape of the super absorbent polymer particles is preferably a normally used powder-like super absorbent polymer particle, but super absorbent polymer particles of other shapes may be used.

As the super absorbent polymer particles, super absorbent polymer particles having a water absorption rate of 70 seconds or less are preferably used. When the water absorption rate is too low, so-called back flow, in which the liquid supplied into the absorbent body 56 is returned to the outside of the absorbent body 56, is likely to occur.

In addition, as the super absorbent polymer particles, it is preferable to use super absorbent polymer particles having a gel strength of 1,000Pa or more. This can effectively suppress the sticky feeling after liquid absorption even when the absorbent body 56 is formed to be bulky.

The basis weight of the super absorbent polymer particles may be determined as appropriate depending on the absorption amount required for the use of the absorbent body 56. Therefore, it can be 50 to 350g/m². When the basis weight of the polymer is less than this range, it is difficult to secure the absorption amount. When the amount exceeds this range, the effect is saturated, and the super absorbent polymer particles are excessively contained, so that the particles give a feeling of discomfort.

(packaging sheet)

The absorbent body 56 may be incorporated as an absorbent unit 50 wrapped with a wrapping sheet 58 in order to prevent the superabsorbent polymer particles from coming off or to improve the shape retention of the absorbent body 56. As the packaging sheet 58, a thin paper, particularly a crepe paper, a nonwoven fabric, a polyethylene laminated nonwoven fabric, a sheet with small holes, or the like can be used. Among them, a sheet in which the super absorbent polymer particles are not separated is preferable. When a nonwoven fabric is used instead of crepe paper, a hydrophilic SMMS (spunbond/meltblown/spunbond) nonwoven fabric is particularly preferable, and polypropylene, polyethylene/polypropylene, or the like can be used as the material. The basis weight of the fiber is preferably 5 to 40g/m²Particularly preferably 10 to 30g/m²。

The packaging sheet 58 may be configured such that the entire absorbent body 56 is wrapped with one sheet as shown in fig. 3, or the entire absorbent body 56 may be wrapped with a plurality of sheets such as upper and lower 2 sheets. The wrapping sheet 58 may be omitted.

(Top sheet)

The top sheet 30 has liquid permeability, and for example, a nonwoven fabric or a porous plastic sheet having holes or holes may be used. The type of the raw material fibers of the nonwoven fabric is not particularly limited. Examples thereof include synthetic fibers such as olefin-based, polyester-based, and polyamide-based fibers, e.g., polyethylene and polypropylene; regenerated fibers such as rayon and cuprammonium fibers; natural fibers such as cotton, and mixed fibers and composite fibers using two or more of these fibers. The nonwoven fabric may be produced by any process. Examples of the processing method include known methods such as a spunlace method, a spunbond method, a thermal bond method, a melt blowing method, a needle punching method, a hot air method, and a point bonding method. For example, if flexibility and drapability are required, the spunlace method is a preferred processing method, and if bulkiness and flexibility are required, the thermal bonding method is a preferred processing method.

The top sheet 30 extends from the front end to the rear end of the product in the front-rear direction and extends to a position more lateral than the absorbent body 56 in the width direction WD, but in the case where the starting points of the standing gathers 60 described later are located more toward the widthwise center side than the side edges of the absorbent body 56, for example, appropriate deformation such as making the width of the top sheet 30 shorter than the full width of the absorbent body 56 can be performed as necessary.

(intermediate sheet)

In order to rapidly transfer the liquid having passed through the top sheet 30 to the absorbent member, an intermediate sheet (also referred to as "second sheet") 40 having a liquid passing speed higher than that of the top sheet 30 may be provided. The intermediate sheet 40 is used to transfer liquid quickly into the absorbent body, to improve the absorption performance by the absorbent body, and to prevent the phenomenon of "back flow" of the absorbed liquid from the absorbent body. The intermediate sheet 40 may also be omitted.

The intermediate sheet 40 may be made of the same material as the top sheet 30, or a spun lace nonwoven fabric, a spun bond nonwoven fabric, an SMS nonwoven fabric, a wood pulp nonwoven fabric, a mixed sheet of pulp and rayon, a point-bonded nonwoven fabric, or crepe paper. In particular, a through-air nonwoven fabric is preferable because it is bulky. In the case where the composite fiber having a core-sheath structure is preferably used for the air-through nonwoven fabric, the resin used for the core may be polypropylene (PP), but Polyester (PET) having high rigidity is preferable. Basis weightPreferably 17 to 80g/m². The thickness of the raw material fiber of the nonwoven fabric is preferably 2.0 to 10 dtex. In order to make the nonwoven fabric bulky, it is also preferable to use a fiber having a core that is not centered, a hollow fiber, or a fiber having a core that is both eccentric and hollow as a mixed fiber of all or a part of the raw material fibers.

The intermediate sheet 40 in the illustrated example is shorter than the width of the absorber 56 and is disposed at the center, but the intermediate sheet 40 may be provided over the entire width. The intermediate sheet 40 may be provided over the entire length of the diaper, but may be provided only in the intermediate portion including the excretion portion as shown in the illustrated example.

(liquid-impermeable resin film)

The liquid-impermeable resin film 11 is not particularly limited as long as it has moisture permeability, and for example, a microporous sheet obtained by kneading an inorganic filler with an olefin resin such as polyethylene or polypropylene, molding the resultant sheet, and then stretching the sheet in a uniaxial or biaxial direction can be suitably used. In particular, a liquid-impermeable resin film having moisture permeability in the thickness direction can be used as the liquid-impermeable resin film 11, and needless to say, the liquid-impermeable resin film 11 does not include a material in which water repellency is improved by using a nonwoven fabric as a base material.

The liquid-impermeable resin film 11 made of a moisture-permeable resin film may be subjected to continuous decorative printing consisting of a plurality of structural units such as characters (size, brand name, manufacturer name, pattern name, etc.) and patterns regularly repeated in the front-back direction LD and the width direction WD, or intermittent decorative printing arranged only on either or both sides of the front and back of a product such as product logo, character figure, photograph, etc., and when such decorative printing is performed, it is preferable that the elongation of the liquid-impermeable resin film 11 is small.

The liquid-impermeable resin film 11 preferably extends in the same or a wider range as the absorbent body 56 in the front-back direction LD and the width direction WD, and may be set in a form not covering the end of the absorbent body 56 in the front-back direction LD and the width direction WD as necessary when other water blocking means are present.

(nonwoven fabric for exterior application)

The outer nonwoven fabric 12 covers the entire back of the liquid-impermeable resin film 11And the outer surface of the product is made into a cloth-like appearance. The outer-covering nonwoven fabric 12 is not particularly limited as long as it has moisture permeability, and examples of the raw material fibers include olefin-based fibers such as polyethylene and polypropylene, synthetic fibers such as polyester and polyamide, regenerated fibers such as rayon and cuprammonium, and natural fibers such as cotton, and the processing method may include spunlace, spunbond, thermal bond, hot air, needle punch, and the like. Among them, long fiber nonwoven fabrics such as spun bond nonwoven fabrics, SMS nonwoven fabrics, SMMS nonwoven fabrics and the like are preferable from the viewpoint of satisfying both the touch feeling and the strength. Instead of using one nonwoven fabric, a plurality of nonwoven fabrics may be used in a stacked state. In the latter case, the nonwoven fabrics are preferably bonded to each other with a hot melt adhesive or the like. When a nonwoven fabric is used, the basis weight of the fibers is preferably 15 to 25g/m²Particularly preferably 18 to 20g/m²。

(vertical pleats)

In order to prevent the excrement moving in the transverse direction along the top sheet 30 and to prevent so-called side leakage, it is preferable that standing gathers 60 standing up toward the skin of the wearer are provided on both sides in the width direction WD of the surface. Of course, the standing gather 60 may be omitted.

When the standing gather 60 is used, the structure thereof is not particularly limited, and any known structure can be used. The raised gathers 60 illustrated in the drawing are composed of a gather sheet 62 substantially continuous in the width direction WD, and an elongated gather elastic member 63 fixed to the gather sheet 62 in an extended state along the front-rear direction LD. As the gather sheet 62, a water repellent nonwoven fabric can be used, and as the gather elastic member 63, a rubber thread or the like can be used. Instead of providing a plurality of elastic members as shown in fig. 1 and 2, 1 elastic member may be provided.

The inner surface of the gather sheet 62 has a joining start end in the width direction WD on the side portion of the top sheet 30, and a portion on the outer side in the width direction from the joining start end is joined to the inner surface of each side flap portion SF, that is, the side portion of the liquid impermeable resin film 11 and the side portion of the outer-covering nonwoven fabric 12 on the outer side in the width direction in the illustrated example, by a hot melt adhesive or the like.

In the leg hole, the portion further inward in the width direction than the joining start end of the standing gather 60 is fixed to the top sheet 30 at both ends in the front-rear direction of the product, but the portion therebetween is an unfixed free portion which stands up by the contraction force of the elastic member 63 and comes into close contact with the body surface.

(wing part, flank part)

The tape-type disposable diaper illustrated in the drawings has a pair of end flaps EF extending to the front side and the rear side of the absorbent body 56, respectively, and not having the absorbent body 56, and a pair of side flaps SF extending laterally from both side edges of the absorbent body 56, respectively, and not having the absorbent body 56.

(plane pleat)

A leg-surrounding elastic member 64 made of an elongated elastic member such as a rubber thread is fixed to each flap portion SF in an extended state along the front-rear direction LD, and thus the leg-surrounding portion of each flap portion SF is configured as a planar gather. The leg elastic members 64 may be provided between the gather sheet 62 and the liquid-impermeable resin film 11 on the outer side in the width direction in the vicinity of the joining start end of the gather sheet 62 in the joined portion as shown in the drawing, or between the liquid-impermeable resin film 11 and the outer-covering nonwoven fabric 12 in the flap portion SF. In addition to the plurality of leg hole elastic members 64 provided on each side as in the illustrated example, only 1 leg hole elastic member may be provided on each side.

(connecting belt)

The side wing portions SF in the back portion B are provided with connecting bands 13, respectively, and the connecting bands 13 are detachably connected to the outer surface of the stomach portion F. When the diaper is worn, the connecting belt 13 is wound around the outer surface of the abdominal portion F from both sides of the waist, and the connecting portion 13A of the connecting belt 13 is connected to an appropriate position on the outer surface of the abdominal portion F.

The structure of the connecting belt 13 is not particularly limited, and in the illustrated example, the connecting belt includes: a sheet base material having a tape mounting portion 13C fixed to the wing portion SF and a tape main body portion 13B protruding from the tape mounting portion 13C; and a connecting portion 13A provided at a widthwise intermediate portion of the belt main body portion 13B in the sheet base material and connected to the abdomen side, and a portion on the distal end side of the connecting portion 13A serves as a grip portion.

The coupling portion 13A may be provided with an adhesive layer in addition to hook members (convex members) of mechanical fasteners (surface fasteners). The hook member has a plurality of engaging projections on its coupling surface, and the engaging projections may have any shape, such as (a) レ shape, (B) J shape, (C) mushroom shape, (D) T shape, (E) double J shape (shape in which the J-shaped engaging projections are coupled back to back).

The sheet base material from the belt mounting portion 13C to the belt body portion 13B may be a nonwoven fabric, a plastic film, a polyethylene laminated nonwoven fabric, paper, or a composite material thereof, and preferably has a fineness of 1.0 to 3.5dtex and a basis weight of 60 to 100g/m²And a spun-bonded nonwoven fabric, a hot-air nonwoven fabric, or a spun-laced nonwoven fabric having a thickness of 1.0mm or less.

(target sheet)

The target sheet 20 having a target for facilitating the joining is preferably provided at the joining portion of the joining band 13 in the abdominal portion F. As the target sheet 20, in the case where the coupling portion 13A is a hook member, a target sheet in which a large number of loop yarns around which the engaging protrusions of the hook member are to be wound are provided on the surface of a sheet base material made of a plastic film or a nonwoven fabric may be used, and in the case of an adhesive layer, a target sheet in which a peeling treatment is applied to the surface of a sheet base material made of a plastic film having a smooth surface and high adhesiveness may be used. In the case where the connecting portion of the connecting band 13 in the stomach-side portion F is formed of a nonwoven fabric, for example, in the case where the exterior nonwoven fabric 12 is provided as in the illustrated example, the target sheet 20 may be omitted and the hook member may be wound around the fiber of the exterior nonwoven fabric 12 to connect the two. In this case, the target sheet 20 may be provided as a mark between the outer nonwoven fabric 12 and the liquid-impermeable resin film 11.

(microfibrous cellulose)

The microfibrous cellulose is a fine cellulose fiber obtained by opening pulp fibers, and is usually a cellulose fiber containing cellulose microfine fibers having an average fiber width of a nanometer size (1nm to 1000 nm), preferably a cellulose having an average fiber width (median diameter) of 100nm or less (usually referred to as Cellulose Nanofibrils (CNF)), and particularly preferably a cellulose having an average fiber width of 10 to 60 nm. Cellulose fibers are numerous substances in which β -glucose is mainly bonded in a chain form by β -1,4 glycosidic bonds. Beta-glucose has an-H group, -OH group, etc.

The microfibrous cellulose has effects of adsorbing moisture (water molecules, etc.), absorbing moisture, and reducing odor. The reason why the microfibrous cellulose has hygroscopicity and odor-reducing properties is not yet established. However, it is considered that one of the reasons may be that moisture components and odor components are physically adsorbed and held on the surface of the microfibrous cellulose, thereby being deprived of the degree of freedom. In addition, the microfibrous cellulose is a molecular structure having a large number of — OH groups, and therefore the microfibrous cellulose has a high affinity for moisture (water molecules and the like).

The dispersion of the microfibrous cellulose is obtained by dispersing the microfibrous cellulose in a solvent. The concentration (mass/volume) of the dispersion of the microfibrous cellulose is preferably 0.1 to 10%, more preferably 1.0 to 5.0%, and particularly preferably 1.5 to 3.0%. Dispersions of more than 10% are difficult or costly to manufacture. Dispersions below 0.1% are not useful because the concentration of microfibrous cellulose is too low. The solvent for dispersing the microfibrous cellulose is not particularly limited, and a volatile organic solvent such as acetone may be used in addition to water and a lower alcohol such as ethanol.

The B-type viscosity (60rpm, 20 ℃) of the dispersion of the microfibrous cellulose is, for example, 700cps or less, preferably 200cps or less, and more preferably 50cps or less. By suppressing the B-type viscosity of the microfibrous cellulose dispersion liquid to such a low level, the aggregates 15 are uniformly applied to the sheet surface, and the sheet surface properties are uniformly improved.

A method for measuring the average fiber width of microfibrous cellulose will be described.

First, 100ml of an aqueous dispersion of microfibrous cellulose having a solid content concentration of 0.01 to 0.1% was filtered through a teflon (registered trademark) membrane filter, and 1-time solvent substitution was performed with 100ml of ethanol and 3-time solvent substitution was performed with 20ml of t-butanol.

Subsequently, freeze-drying was performed, and osmium was applied to the sample. The sample was observed at any of 5000 times, 10000 times, or 30000 times (in the present example, 30000 times) according to the width of the fiber to be formed, based on the SEM image of the electron microscope. Specifically, two diagonal lines are drawn in the observation image, and three straight lines passing through the intersections of the diagonal lines are arbitrarily drawn. Further, a total of 100 fiber rods crossing the three straight lines were visually measured. And, the median diameter (mean diameter) of the measured values was taken as the average fiber width. The average fiber diameter is not limited to the median diameter of the measured values, and may be, for example, a number average diameter or a mode diameter (maximum probability diameter).

Examples of pulp fibers that can be used for the production of microfibrous cellulose include chemical pulp such as hardwood pulp (LBKP) and softwood pulp (NBKP); mechanical pulp such as bleached thermomechanical pulp (BTMP), groundwood pulp (SGP), pressure groundwood Pulp (PGW), Refined Groundwood Pulp (RGP), Chemical Groundwood Pulp (CGP), high Temperature Groundwood Pulp (TGP), Groundwood Pulp (GP), thermomechanical pulp (TMP), chemical thermomechanical pulp (CTMP), disc-milled mechanical pulp (RMP), etc.; waste paper pulp produced from tea waste paper, kraft envelope waste paper, magazine waste paper, newspaper waste paper, leaflet waste paper, office waste paper, corrugated paper waste paper, high-white waste paper, kent waste paper, imitation waste paper, securities waste paper, grass paper waste paper, etc.; deinked pulp (DIP) obtained by deinking waste paper pulp, and the like. These pulps may be used alone or in combination of two or more kinds as long as the effects of the present invention are not impaired. Further, a material obtained by subjecting the pulp fiber to chemical treatment such as carboxymethylation may be used.

Examples of the method for producing the microfibrous cellulose include mechanical methods such as a high-pressure homogenizer method, a microfluidizer method, a mill grinding method, a bead mill freeze-pulverization method, and an ultrasonic defibration method, but are not limited to these methods. In addition, microfibrillation is promoted by oxidation treatment with TEMPO, phosphorylation treatment, acid treatment, and the like in combination.

(aggregate)

The aggregate of the present embodiment includes a humectant and at least one of microfibrous cellulose and aggregated particles thereof (hereinafter, also referred to as "microfibrous cellulose and the like" in the present specification).

For example, the aggregate preferably contains a humectant and at least one of microfibrous cellulose and aggregated particles thereof in a total amount of 4 to 100 parts by mass, preferably 6 to 24 parts by mass, and more preferably 9 to 13 parts by mass, per 100 parts by mass of the aggregate.

The aggregate may contain 0.25 parts by mass, more preferably 0.4 parts by mass, and still more preferably 1.0 part by mass of the total of the microfibrous cellulose and the microfibrous cellulose aggregated particles, relative to 1 part by mass of the humectant. When the amount exceeds 1.0 part by mass, the aggregates become hard due to the hardness property of the microfibrous cellulose.

The humectant may comprise a polyol. The humectant may be constituted of the polyol in the entire amount thereof, or may be constituted of the polyol in a part thereof. The polyol may be a water-soluble material. In order to separate the polyol from the solution in which water and the polyol are mixed, the separation can be performed by a known chemical separation method. In one example, the polyol and water may be separated by a fractional distillation method and a freezing method by cooling because they have different boiling points and freezing points. In the case of extracting the humectant from the aggregate, the extraction may be performed by a known extraction method using an organic solvent. By separating and concentrating the extracted substance by a known method, various components contained in the humectant can be qualitatively and quantitatively measured.

Examples of the substance that may be contained in the moisture-retaining agent other than the polyhydric alcohol include ethanol. The ethanol has a certain volatility, and can inhibit the humectant from excessively adhering. In addition, a humectant containing ethanol is preferable because it has moderate quick-drying property and high moisturizing ability.

The volume ratio of ethanol to polyol when the humectant contains ethanol may be, for example, 1: 1.5-1: 4.

as the polyol, a known polyol can be suitably used. Examples thereof include glycerin, diglycerin, ethylene glycol, polyethylene glycol, propylene glycol, 1, 3-butylene glycol, hexylene glycol, mannitol, propylene glycol, dipropylene glycol, tripropylene glycol, 1, 2-pentanediol, 1, 3-propanediol, sorbitol, and polyethylene glycol. In particular, diglycerin, polyethylene glycol, dipropylene glycol, and 1, 3-butanediol are preferable because they have high moisturizing ability and transparency. In addition, when aggregates having high transparency and containing diglycerin, polyethylene glycol, dipropylene glycol, and 1, 3-butanediol as main components are used, it is difficult to distinguish between a portion coated with the aggregates and a portion not coated with the aggregates. Therefore, for example, even if the aggregate is provided on the liquid-impermeable resin film subjected to design or the like, there is an advantage that the clarity (famous) of the design or the like is not impaired. These polyols may be used in 1 kind or in combination of 2 or more kinds. However, the polyhydric alcohol is not limited to the above-exemplified ones.

In addition, a nonionic surfactant can be exemplified as a substance that can be contained in the aggregate in addition to the microfibrous cellulose and the like and the humectant. The nonionic surfactants described below are preferred because they have transparency and also have the effect of dispersing microfibrillar cellulose and the like and suppressing adhesion. Examples of the nonionic surfactant include polyoxyethylene hydrogenated castor oils typified by PEG-40 to PEG-60 hydrogenated castor oils, and PEG-20 sorbitan cocoate, sorbitan fatty acid esters, glycerin fatty acid esters, polyglycerin fatty acid esters, propylene glycol fatty acid esters, polyoxyethylene sorbitan fatty acid esters, polyoxyethylene sorbitol fatty acid esters, polyoxyethylene glycol fatty acid esters, polyoxyethylene glycerin fatty acid esters, polyoxyethylene alkyl ethers, polyoxyethylene phytosterols, polyoxyethylene castor oils, polyoxyethylene alkylamines, polyoxyethylene fatty acid amides, and alkyl glucosides. These nonionic surfactants may be used in combination of 1 or more than 2.

When the nonionic surfactant is contained in an amount of 0.01 to 4% by mass based on 100% by mass of the aggregate, the aggregate is preferably transparent and the adhesion is suppressed. In particular, hydrogenated castor oils of PEG-40 to PEG-60 are in the form of paste, and thus can be suitably contained in the aggregate. In this case, any one of hydrogenated castor oils of PEG-40 to PEG-60 and other nonionic surfactants was added in a mass ratio of 1: 1-1: the blending may be carried out in the manner of 5.

In addition, the following substances may also be contained in the humectant. Specifically, there may be mentioned 1 kind of vaseline, spindle oil, castor oil, olive oil, refined mineral oil, liquid paraffin, polybutene, α -olefin, oligomer or co-oligomer of α -olefin, dimethyl silicone oil, methylphenyl silicone oil, amino-modified silicone oil, polyether-modified silicone oil, fatty acid-modified silicone oil, and the like (hereinafter, sometimes referred to as "substances such as vaseline"), or 2 or more kinds thereof may be used in combination.

The humectant may be thickened to an appropriate viscosity by the addition of a thickener. Examples of the thickener include silica having a surface subjected to hydrophobic treatment, microsilica having a surface subjected to methylation treatment, aluminum silicate, swellable mica, a clay-based thickener such as bentonite or montmorillonite subjected to hydrophobic treatment, a fatty acid metal soap such as magnesium stearate, calcium stearate, aluminum stearate, or zinc stearate, a dextrin-based compound such as tribenzylsorbitol, a fatty acid amide, an amide-modified polyethylene wax, hydrogenated castor oil, or a fatty acid dextrin, and a cellulose-based compound.

The humectant may contain moisture. The humectant may be in the form of a gel, colloid, paste, slurry, cake, cream, or emulsion, which is hardly volatile, but is not limited thereto. The moisturizer may or may not be tacky. The humectant may be deformable by application of an external force, or may be deformable without application of an external force, and is preferably resistant to deformation without application of an external force. An absorbent article provided with a functional sheet to which aggregates of microfibrous cellulose or the like containing the humectant that is less likely to deform are attached is particularly preferred because the aggregates stay at the position where they are attached even when the absorbent article is placed for a long period of time in the vertical direction, the horizontal direction, or the like. Of course, even when the humectant is not difficult to deform, the microfibrous cellulose or the like has an effect of anchoring the humectant and the sheet (anchoring effect), and therefore an absorbent article provided with a functional sheet to which the humectant is not difficult to deform is a preferable embodiment in which the aggregating agent stays at the same position regardless of the placement.

As an example, a mixing manner of the microfibrous cellulose 101 and the microfibrous cellulose aggregated particles 102 in the aggregate with other components (for example, the humectant 103) can be described below. However, the present invention is not limited to the following.

Referring to fig. 15, a combination method is described, which may be exemplified by a method in which the 1 st microfibrous cellulose 101 or aggregated particles 102 thereof and the 2 nd microfibrous cellulose 101 or aggregated particles 102 thereof are linked by other components (e.g., a humectant 103). Other ingredients (e.g., humectant 103) may be attached to a portion of the microfibrous cellulose 101 or its aggregated particles 102, or may be attached to the entirety. Alternatively, another component (for example, the humectant 103) may be attached to the entire surface of the microfibrous cellulose 101 or the entire surface of the aggregated particles 102 thereof. The microfibrous cellulose 101 shown by the broken line in fig. 15(b) shows that another component (for example, a humectant 103) adheres to the entire surface of the microfibrous cellulose 101.

(functional sheet)

The functional sheet can be used for sheets constituting various portions of the absorbent article. For example, the functional sheet may be used for at least one of the liquid-permeable top sheet 30, the intermediate sheet 40, the liquid-impermeable resin film 11, and the outer-cover nonwoven fabric 12.

The amount of the cellulose-containing aggregate to be applied to the nonwoven fabric may be different depending on the use of the nonwoven fabric, or may be the same regardless of the use of the nonwoven fabric. For example, when a nonwoven fabric is used as the outer surface of the top sheet 30 or the outer nonwoven fabric 12, the amount of adhesion is set to 13g/m²Below, preferably 10g/m²The following is preferable. In addition, the amount of adhesion can be set to 2g/m²The above. If the amount of adhesion is 13g/m²Hereinafter, the attached portion does not give a sticky impression and has a good touch. As long as the aggregate is adhered to the nonwoven fabric, there is no need to set the lower limit of the amount of adhesion, for example, 2g/m²As described above, the microfibrous cellulose has a particularly good moisture absorption effect.

When the aggregate is applied to the inner surface of the nonwoven fabric 12, the amount of application may be (a)Attached amount) of more than 13g/m². The inner surface of the outer nonwoven fabric 12 is positioned inside the product, and the skin does not contact the inner surface of the outer nonwoven fabric 12, so that the stickiness is not felt easily.

In addition, the condensation product may be applied to the inner or outer surface of the topsheet 30. In particular, in the case of a product in which the aggregate is applied (adhered) to the inner surface of the top sheet 30, the application surface of the aggregate, that is, the inner surface of the top sheet 30, comes into contact with the skin. Even in this case, the amount of the aggregate applied (amount of the aggregate deposited) is 13g/m²Hereinafter, the coated portion is also less likely to feel sticky. Even if the product is coated with the aggregate on the outer surface, the coating amount of the aggregate can be 13g/m²The following. It is preferable that the excretory fluid excreted to the topsheet 30 quickly penetrate and be absorbed by the absorbent body 56. If the outer surface of the top sheet is coated with more than 13g/m²The amount of the aggregate may inhibit rapid permeation of the excretion liquid.

In particular, in the case of a product in which the aggregate is applied to the inner surface of the top sheet 30, the application surface of the aggregate, that is, the inner surface of the top sheet 30, comes into contact with the skin. Even in this case, the amount of the aggregate applied (amount of the aggregate deposited) is 13g/m²Hereinafter, the coated portion is also less likely to feel sticky. Even if the aggregate is coated on the outer surface, the amount of the aggregate to be coated (amount of the aggregate to be adhered) may be 13g/m²The following. It is preferable that the excretory fluid excreted to the topsheet 30 quickly penetrate and be absorbed by the absorbent body 56. If it exceeds 13g/m²When the aggregate of (2) is applied to the outer surface of the top sheet, the aggregate may prevent rapid permeation of the discharged liquid.

In addition, the condensate may be applied to the inner or outer surface of the intermediate sheet 40. The intermediate sheet 40 is used to improve the absorption performance of the absorbent body by allowing the liquid that has passed through the top sheet 30 to rapidly migrate toward the absorbent body. Glycerin is easily soluble in water, and when the aggregate is applied to the intermediate sheet 40, the liquid dissolves into the aggregate due to the solubility of glycerin, and diffusion of the liquid in the front-back direction and/or the width direction of the intermediate sheet 40 is promoted. As a result, the migration of the liquid to the absorbent body is more smoothly performed, and the phenomenon of the backflow of the liquid is suppressedAnd (5) preparing. The amount of the aggregate coated on the inner surface or the outer surface of the intermediate sheet 40 may be, for example, 13g/m²The following. If it exceeds 13g/m²The adhesive strength with other functional sheets may be weakened.

(joining)

The components shown in the sectional views of fig. 3 to 7 are joined together by an adhesive as a joining means for joining. For example, the respective surfaces of the liquid-permeable top sheet 30 facing the center sheet 40, the respective surfaces of the liquid-permeable top sheet 30 or the center sheet 40 facing the absorbent body 56, the respective surfaces of the absorbent body 56 facing the liquid-impermeable resin film 11, and the respective surfaces of the liquid-impermeable resin film 11 facing the outer-cover nonwoven fabric 12 are joined. However, the joint portion is not limited to these listed respective faces.

When the components are joined to each other, if the aggregate is applied to one of the facing surfaces, the joining by the adhesive may be weakened at the portion where the aggregate is applied. In this case, the bonding can be performed by reducing the amount of the aggregate applied. However, even if the coating amount of the adhesive is increased without decreasing the coating amount of the aggregate, the constituent members can be bonded to each other. The aggregate may be applied to both the front and back surfaces of the sheet, or may be applied only to the front or back surface.

As illustrated in fig. 14, the following method can be used for the coating pattern of the aggregate: the aggregate 15 is disposed on both surfaces or one surface of the sheet 111, and linear portions continuous in the front-rear direction are formed into stripe-shaped portions arranged at intervals in the width direction, and the adhesive 81 is disposed at these intervals in the front-rear direction, that is, such that the adhesive 81 forms stripe-shaped portions. One face of the sheet 111 may then be covered with another sheet, and the sheets joined to one another. In this way, since the aggregates 15 are not interposed between the sheets at the joint portions, the sheets can be firmly bonded by the adhesive 81, and the bonding strength between the constituent members is not weakened.

As another coating pattern, as shown in fig. 16, an example in which the aggregates 15 are arranged in a lattice shape on the sheet 111 can be given. The adhesive 81 is disposed so as to form stripe-shaped portions in which linear portions continuous in the front-rear direction are arranged at intervals in the width direction. The adhesive 81 may be disposed so as to pass through a portion where no aggregate is disposed, that is, through the lattice holes, but is not limited thereto. Further, although not shown, the adhesive 81 may be disposed only in the lattice holes.

In the above bonding example, the aggregate 15 is disposed in a linear shape continuous in the front-rear direction on one surface of the sheet 111, but the present invention is not limited to this, and the aggregate 15 may be disposed so as to form a stripe-shaped portion in which linear portions continuous in the width direction are arranged at intervals in the front-rear direction. The direction in which the aggregate 15 travels may be arranged to be continuous in an oblique direction on the paper surface.

As shown in fig. 8, a plurality of aggregates 15 may be arranged on one surface of the sheet 111 at intervals of a dot shape. Although not particularly limited, in one example, the size of each dot is preferably 1.0 to 4.0mm, and the interval between dots is preferably 5 to 30 mm. The arrangement of the dots of the aggregate 15 is not particularly limited, and may be, for example, an arrangement in which an orthorhombic lattice is formed (fig. (a), (b), (e)), or an arrangement in which a lattice is formed (fig. (c), (d)). In this case, the adhesive 81 can be appropriately provided in a portion where no spot is disposed.

When the aggregate is applied to a sheet, the aggregate may be applied to only one surface of the sheet, or may be applied to both surfaces of the sheet. The aggregate may be uniformly coated on the entire surface of the sheet, or may be partially coated on the surface of the sheet. For example, the aggregate may be applied to at least the portion of the sheet surface overlapping the absorber 56. The absorber 56 is a part that absorbs excretory fluid, and is considered to have high moisture after excretion. If the microfibrous cellulose or the like is provided in the portion of the sheet surface that overlaps the absorber 56, moisture emitted from the absorber 56 is effectively absorbed by the microfibrous cellulose or the like, and the dryness of the sheet can be maintained.

(Pleated)

Conventionally, when a coating portion having a microfibrous cellulose dispersion applied to a sheet surface is dried, uneven wrinkles are formed in the sheet along the coating portion (see fig. 12). Fig. 12 is coated with a microfibrous cellulose dispersion without humectant in area 80. In the region 80, the relatively white portion 31 is formed with wrinkles projecting forward in the depth direction in a plan view. In addition, the relatively black portion 32 is formed with wrinkles that are convex (concave forward) to the depth direction depth in a plan view, and the entire region 80 is formed with uneven wrinkles. The sheet feels sticky, dry, hard, so to speak, a hard snap feeling.

On the other hand, the coated portion on the surface of the sheet coated with the aggregate was wet even after several weeks, and the uneven wrinkles shown in fig. 12 were not formed (see fig. 13). Fig. 13 is a graph of 3% coating in region 90 with microfibrous cellulose to humectant: 10 of a coagulated product. There are substantially no asperities in the region 90. With regard to the hand of the sheet, there is substantially no sticky feeling, and a smooth impression is felt.

(production)

The functional sheet and the absorbent article can be produced by the following steps, for example, without any particular limitation.

(1) And mixing the microfibrous cellulose dispersion with a humectant to obtain an aggregate.

(2) And a step of coating the aggregate on a sheet to obtain a functional sheet.

(3) And a step of forming the functional sheet into at least one of a liquid-permeable top sheet, a liquid-impermeable resin film, and an outer-covering nonwoven fabric in an absorbent article having the liquid-permeable top sheet covering the inner surface of an absorbent body, the liquid-impermeable resin film covering the outer surface of the absorbent body and having moisture permeability, and the outer-covering nonwoven fabric covering the outer surface of the liquid-impermeable resin film and having moisture permeability.

Through the above steps, an absorbent article can be manufactured.

Specifically, the functional sheet is produced by first mixing a microfibrous cellulose dispersion with another component (e.g., a humectant) to prepare a mixed solution. The mixing ratio may be as described above. The microfibrous cellulose dispersion may contain microfibrous cellulose in a concentration of, for example, 2 to 3%. Preferably, the mixture is stirred by a magnetic stirrer or a stirring device such as a glass rod to achieve a uniform concentration. The mixed solution may be appropriately mixed with a nonionic surfactant, a substance such as vaseline, and a thickener. The aggregate obtained by stirring is applied to one or both surfaces of the target sheet. Then, the sheet was dried for 3 hours to evaporate water in the aggregate, thereby obtaining a functional sheet. The drying method may be a method of air drying or a method of blowing hot air using a dryer or the like.

(use of functional sheet in absorbent article)

An absorbent article is produced by a known method using at least one of a liquid-permeable top sheet, a liquid-impermeable resin film, and an outer-covering nonwoven fabric as a functional sheet. For example, when a functional sheet having a single-sided aggregate coated thereon is used as the outer-covering nonwoven fabric, when the coated surface is the outer side of the absorbent article, it is preferable to join a surface of the outer-covering nonwoven fabric which is not the coated surface to a member (for example, a liquid-impermeable resin film) provided on the inner side of the outer-covering nonwoven fabric of the absorbent article. Thus, the coated surface of the exterior nonwoven fabric serves as the outer surface of the product.

(examples)

(preparation of sample)

(1) The coating weight after air drying was 4g/m²In the mode (1), the aggregate was uniformly applied to the surface of the nonwoven fabric in a 10cm square. Here, air drying means drying in a laboratory at 23 ℃. + -. 1 ℃ under normal pressure for 3 hours. The raw material of the non-woven fabric is polypropylene fiber (PP) which is spun-bonded, and the basis weight is 15g/m². As shown in table 1, the blend ratio of the amount (g) of the microfibrillar Cellulose (CNF) in an absolutely dry state and the amount (g) of glycerin was varied in various ways to prepare aggregates (examples 1 to 5 shown in table 1). As a comparative example, an aggregate composed only of glycerin was used as comparative example 1, and an aggregate composed only of microfibrous cellulose was used as comparative example 2. The absolute dry state is a state in which the film is dried at 105 ℃ for 1 hour and cooled to room temperature by a dryer.

(2) The coated nonwoven fabric was air-dried at 23 ℃. + -. 1 ℃ under normal pressure for 3 hours to prepare a sample (test example). The inventors found that the mass of the coated nonwoven fabric was not reduced any more and was substantially fixed when the nonwoven fabric was air-dried at 23 ℃. + -. 1 ℃ under normal pressure for 3 hours or more or when the nonwoven fabric was dried by a dryer for 3 hours or more.

(3) The obtained sample was measured for flexibility, tackiness, transfer ratio, and moisture absorption amount.

(softness)

The both ends of the sample were pinched with both hands, and the sample was bent or twisted several times to evaluate flexibility. The evaluation method is as follows.

"verygood": no stiffness was felt and a soft impression was felt.

Good for: substantially no stiffness was felt and a slightly softer impression was felt.

". DELTA": the coating was hard and no cracks or fractures were generated in a part of the coating portion.

"×": the coating layer was strongly hard, and cracks or fractures were generated in a part of the coating layer.

(with or without tackiness)

The coated part was contacted with the skin, and the coated part was evaluated for the presence or absence of adhesion.

"verygood": no stickiness was observed at all in the coated portion, and no sticky impression was observed at all.

Good for: the coating portion was not substantially sticky, and the impression of stickiness was not substantially felt.

". DELTA": the coating portion was slightly sticky and slightly sticky.

"×": the coating portion was strongly sticky and had a sticky impression.

(transfer amount)

The whole coating part was covered with a filter paper having a known mass, and a 1kg weight was placed on the filter paper and allowed to stand for 1 minute. After that, the weight and the flat plate were removed, and the mass of the filter paper (mass after transfer) was measured. Then, the transfer amount is determined by the following equation.

Transfer amount (g) ═ mass of filter paper (mass after transfer (g)) -mass of filter paper (mass before transfer (g))

(amount of moisture absorption)

The sample coated with the aggregate was placed in a constant temperature and humidity bath adjusted to 40 ℃ and 90% humidity, and after standing for 1 hour, the mass of the sample was measured. Then, the moisture absorption amount is obtained by the following equation.

Moisture absorption amount (g) — the mass of the sample after being left in the constant temperature and humidity chamber for 1 hour (mass after moisture absorption (g)) — the mass of the sample before being left in the constant temperature and humidity chamber (mass before moisture absorption (g))

[ TABLE 1 ]

The invention made by the inventors is explained as one embodiment. However, the present invention should not be limited by the description and drawings showing the present embodiment. Other examples and the like that a person skilled in the art can make based on the present embodiment are included in the present invention.

< description of terms in the specification >

Unless otherwise specified, the following terms used in the specification have the following meanings.

"longitudinal direction" refers to a direction connecting a ventral side (front side) and a dorsal side (back side), and "width direction" refers to a direction (left-right direction) perpendicular to the longitudinal direction.

"medial" refers to the side closer to the wearer's skin and "lateral" refers to the side farther from the wearer's skin. The "inner surface" refers to the face of the component that is closer to the wearer's skin, and the "outer surface" refers to the face that is further from the wearer's skin.

"LD direction" and "WD direction" refer to a flow direction (LD direction) in a manufacturing apparatus and a lateral direction (WD direction) orthogonal to the flow direction, and one of them is a front-back direction of a product and the other is a width direction of the product. The LD direction of the nonwoven fabric is the direction in which the fibers of the nonwoven fabric are oriented. The fiber orientation is a direction in which fibers of the nonwoven fabric are oriented, and can be determined by, for example, a measurement method according to a fiber orientation test method of zero-distance tensile strength by TAPPI standard method T481, or a simple measurement method of determining the fiber orientation direction from the tensile strength ratio between the front-back direction and the width direction.

"expanded state" refers to a state of flat expansion without contraction or relaxation.

"gel strength" was determined as follows. 49.0g of a super absorbent polymer was added to 49.0g of artificial urine (prepared by mixing 2 wt% of urea, 0.8 wt% of sodium chloride, 0.03 wt% of calcium chloride dihydrate, 0.08 wt% of magnesium sulfate heptahydrate, and 97.09 wt% of ion-exchanged water), and the mixture was stirred with a stirrer. The resultant gel was allowed to stand in a constant temperature and humidity bath at 40 ℃ X60% RH for 3 hours, and then returned to normal temperature, and the gel strength was measured by a curdometer-MAX ME-500 (manufactured by I.techno Engineering Co.).

"basis weight" is determined as follows. After the sample or test piece was preliminarily dried, it was placed in a laboratory or apparatus in a standard state (temperature at the test site was 23. + -. 1 ℃ and relative humidity was 50. + -. 2%) so as to be in a state of constant volume. Pre-drying refers to bringing the sample or test strip to a constant level in an environment at a temperature of 100 ℃. The fibers having a official moisture regain of 0.0% may not be subjected to preliminary drying. A100 mm X100 mm-sized sample was cut out from a test piece in a constant state using a template (100mm X100 mm) for sample collection. The weight of the sample was measured and multiplied by 100 to calculate the weight per 1 square meter as the basis weight.

"thickness" using an automatic thickness tester (KES-G5 portable compression tester), under load: 0.098N/cm²And a pressing area: 2cm²Under the conditions of (1) automatically.

"Water absorption" was measured by JIS K7223-1996 "method for testing Water absorption of super absorbent resin".

"Water absorption Rate" the "time to end point" in the "Water absorption Rate test method for highly Water-absorbent resin" of JIS K7224-1996 was carried out using 2g of a highly Water-absorbent Polymer and 50g of physiological saline.

Coating weight g/m of aggregate²Is the value after air drying.

The test or measurement is carried out in a laboratory or apparatus in a standard state (the temperature at the test site is 23 ± 1 ℃, and the relative humidity is 50 ± 2%) without description of the environmental conditions in the test or measurement.

Unless otherwise specified, the dimensions of each part are dimensions in the expanded state, not in the natural length state.

Industrial applicability

The present invention can be applied to all types of disposable diapers such as pants-type disposable diapers and pad-type disposable diapers, as well as to other absorbent articles such as sanitary napkins, as well as to tape-type disposable diapers as in the above examples.

Description of the reference symbols

11 … liquid-impermeable resin film, 12 … outer non-woven fabric, 13 … joining tape, 13a … joining part, 13B … tape main body part, 13C … tape mounting part, 15 … aggregate, 20 … target sheet, 30 … top sheet, 40 … intermediate sheet, 50 … absorbent unit, 56 … absorber, 56W … absorber width, 58 … packaging sheet, 60 … standing gather, 62 … gather sheet, 81 … hot melt adhesive, 101 … microfibrous cellulose, 102 … microfibrous cellulose aggregate particles, 103 … humectant, B … back side part, F … belly side part, WD … width direction, LD … front-back direction.

Claims

1. A functional sheet characterized by having an aggregate of at least one of microfibrous cellulose containing a humectant and aggregated particles thereof adhered to the sheet.

2. The functional sheet according to claim 1, wherein the aggregate comprises 0.25 to 1.0 part by mass in total of the microfibrous cellulose and the aggregated particles thereof per 1 part by mass of the humectant.

3. An absorbent article, characterized by comprising:

a liquid-permeable top sheet covering the inner surface of the absorbent body;

a liquid-impermeable resin film having moisture permeability covering an outer surface of the absorbent body; and

at least one of the liquid-permeable top sheet, the liquid-impermeable resin film, and the outer-cover nonwoven fabric is the functional sheet according to claim 1 or claim 2.

4. The absorbent article of claim 3,

the exterior nonwoven fabric is the functional sheet according to claim 1 or claim 2,

13.0g/m is provided on one surface of the functional sheet²The aggregate described below was obtained by mixing a water-soluble polymer,

the one surface is an outer surface of the exterior nonwoven fabric.

5. The absorbent article of claim 3,

the aggregate is provided on one surface of the functional sheet,

the one surface is an inner surface of the exterior nonwoven fabric.

6. The absorbent article according to any one of claims 3 to 5,

the liquid-permeable top sheet is the functional sheet according to claim 1 or claim 2,

13.6g/m is provided on one side of the functional sheet²The aggregate described below was obtained by mixing a water-soluble polymer,

the one surface is an inner surface of the liquid-permeable top sheet.

7. The absorbent article according to claim 6, wherein the aggregate provided on the inner surface of the moisture-permeable top sheet has striped portions arranged at intervals in the width direction with linear portions continuous in the front-back direction.

8. A method for manufacturing an absorbent article, comprising the steps of:

coating the aggregate on a sheet to obtain a functional sheet; and

and a step of forming the functional sheet into at least one of a liquid-permeable top sheet, a liquid-impermeable resin film, and an outer-covering nonwoven fabric in an absorbent article, wherein the absorbent article comprises the liquid-permeable top sheet covering the inner surface of an absorbent body, the liquid-impermeable resin film covering the outer surface of the absorbent body and having moisture permeability, and the outer-covering nonwoven fabric covering the outer surface of the liquid-impermeable resin film and having moisture permeability.