JP2020151352A - Moisture-absorbing sheet, disposable wearing article and manufacturing method of the same - Google Patents

Abstract

To provide a moisture-absorbing sheet excellent in air permeability for releasing moisture, and excellent in air permeability for efficiently supplying moisture to a moisture-absorbing material, and to provide a disposable wearing article and a manufacturing method of the same.SOLUTION: A moisture-absorbing sheet 15 comprises: a nonwoven fabric 16 in which thin wall parts 16t constricted in a thickness direction are repeatedly formed at intervals; and minute fibrous cellulose aggregates 17 adhering into the thin wall parts 16t.SELECTED DRAWING: Figure 11

Description

The present invention relates to a hygroscopic sheet, a disposable worn article, and a method for producing the same.

It has been proposed that disposable wear items such as disposable diapers and sanitary napkins have hygroscopicity for various reasons.

For example, disposable wear items such as disposable diapers and sanitary napkins have an absorber that absorbs excrement such as urine and a liquid-impermeable resin film that covers the back side of the absorber, and is stuffy when worn. In order to prevent this, a liquid-impermeable resin film having moisture permeability in the thickness direction has been used (see, for example, Patent Documents 1 and 2). Further, in many absorbent articles, the back side of the liquid-impermeable resin film has been covered with an exterior non-woven fabric in order to give the outer surface of the product a cloth-like feel and appearance (see, for example, Patent Document 2). ).

However, in the conventional absorbent article, the high moisture permeability of the liquid-impermeable resin film is a disaster to prevent stuffiness, and the outer surface of the product and the underwear retain the moisture after the absorber absorbs the excrement liquid. However, when I touched it with my hands, I sometimes misunderstood it as if it had leaked.

This problem can be solved by reducing the moisture permeability of the liquid-impermeable resin film, but in that case, the decrease in stuffiness prevention property cannot be avoided. Therefore, for example, it has been proposed to provide a moisture absorbing layer on a liquid-impermeable resin film or an exterior non-woven fabric (see, for example, Patent Document 1).

In addition, since disposable wear articles generally have poor breathability, it is known that the inside of disposable wear articles tends to get stuffy when worn, and it has been proposed to attach a moisture absorbing sheet to prevent this (for example, patent documents). See 3).

Further, a moisture absorbing sheet may be used as a product packaging material or in the product packaging (see, for example, Patent Document 4).

However, in the hygroscopic sheet, not only the performance of the hygroscopic material, but also the breathability to release the moisture and the breathability to supply the moisture to the hygroscopic material are important, and the conventional one is improved in this respect. There was room.

Japanese Patent No. 6442098 JP-A-2017-144174 JP-A-2010-279621 JP-A-2010-279606

Therefore, a main object of the present invention is to provide a hygroscopic sheet having excellent breathability for allowing moisture to escape and for efficiently supplying moisture to a hygroscopic material, a disposable worn article, and a method for producing the same.

The moisture absorbing sheets and the like that solve the above problems are as follows.
<First aspect>
A non-woven fabric in which thin-walled parts contracted in the thickness direction are repeatedly formed at intervals,
It has a fine fibrous cellulose aggregate adhering to the thin wall portion.
A moisture-absorbing sheet that is characterized by this.

(Action effect)
This hygroscopic sheet is based on a non-woven fabric in which thin-walled portions are repeatedly formed at intervals, and is characterized in that fine fibrous cellulose aggregates having high hygroscopicity are adhered to the thin-walled portions. Therefore, even if the moisture absorbing sheet is used by being sandwiched between objects or members, a ventilation gap is formed between the object or member and the thin portion of the moisture absorbing sheet. Therefore, in this moisture absorbing sheet, moisture can be released along the surface of the moisture absorbing sheet through the ventilation gap. Further, in the process, moisture can be efficiently supplied to the fine fibrous cellulose aggregate which is a hygroscopic material to absorb moisture. Such a moisture absorbing sheet can be used alone or can be used as a member of a disposable wear article as described later.

<Second aspect>
It does not have the fine fibrous cellulose aggregate other than the thin-walled portion.
The moisture absorbing sheet of the first aspect.

(Action effect)
The microfibrous cellulose aggregate is hard. Therefore, it is preferable that the moisture-absorbing sheet has the fine fibrous cellulose aggregate attached only to the thin-walled portion. As a result, the moisture-absorbing sheet can be flexibly deformed except for the thin-walled portion, and the user or the wearer is less likely to touch the hard thin-walled portion, or the hardness is less likely to be transmitted to the skin.

<Third aspect>
The thin-walled portions are provided in a striped or lattice pattern.
The moisture absorbing sheet of the first or second aspect.

(Action effect)
When the thin-walled portions are provided in a striped or lattice pattern, the continuity of the ventilation gap is increased. Therefore, the air permeability for allowing moisture to escape and the air permeability for efficiently supplying moisture to the hygroscopic material become even more excellent.

<Fourth aspect>
The non-woven fabric constituting the moisture absorbing sheet is a short-fiber non-woven fabric having a fineness of ² to 10 dtex and a grain size of 20 to 40 g / m ² .
The amount of the fine fibrous cellulose aggregate adhered to the thin-walled portion is made of fine fibrous cellulose of 0.1 to 5.0 g / m ² .
The moisture absorbing sheet of the first or second aspect.

(Action effect)
The non-woven fabric constituting the moisture-absorbing sheet is not particularly limited, but is preferably a non-woven fabric within the above range because it is bulky and has excellent shapeability. Further, in order to improve the hygroscopicity, it is best to have a large amount of the fine fibrous cellulose aggregate attached, but if it is too large, the product becomes unnecessarily hard. Therefore, the content of the fine fibrous cellulose aggregate in the thin-walled portion is preferably within the above range.

<Fifth aspect>
Absorbent and
A breathable liquid-impermeable resin film provided on the back side of the absorber, and
An exterior non-woven fabric that covers the back surface of the liquid-impermeable resin film,
In disposable wear items with
It has a moisture-absorbing sheet provided between the liquid-impermeable resin film and the exterior non-woven fabric.
The moisture absorbing sheet has a non-woven fabric in which thin-walled portions contracted in the thickness direction are repeatedly formed at intervals, and a fine fibrous cellulose aggregate adhering to the thin-walled portions.
A ventilation gap is provided between the exterior non-woven fabric and the thin-walled portion and between the liquid-impermeable resin film.
Disposable wear goods characterized by that.

(Action effect)
In this disposable wearable article, a moisture absorbing sheet of the first aspect is interposed between a liquid-impermeable resin film and an exterior non-woven fabric to form a ventilation gap. Therefore, according to this disposable wearable article, the moisture discharged from the liquid-impermeable resin film, which increases after absorption of the excrement liquid, can be effectively absorbed by the moisture absorbing sheet, and the outer surface of the product and the underwear feel moist. It becomes difficult to become.

<Sixth aspect>
A breathable skin contact layer that touches the wearer's skin,
It has a moisture absorbing sheet provided so as to have a portion adjacent to the back side of the skin contact layer.
The moisture absorbing sheet has a non-woven fabric in which thin-walled portions contracted in the thickness direction are repeatedly formed at intervals, and a fine fibrous cellulose aggregate adhering to the thin-walled portions.
Each has a ventilation gap between the skin contact layer and the thin-walled portion.
Disposable wear goods characterized by that.

(Action effect)
This disposable wearable article is provided with a moisture absorbing sheet so as to have a portion adjacent to the back side of the skin contact layer in order to prevent stuffiness during wearing. As a result, stuffiness can be prevented by efficiently absorbing the moisture inside the disposable worn article at the time of wearing or letting it escape to the outside.

<7th aspect>
The dispersion liquid of fine fibrous cellulose is applied to the non-woven fabric in a pattern that repeats at intervals, and the dispersion liquid is dried to form the thin-walled portion in the coated portion of the dispersion liquid and to the thin-walled portion. A step of manufacturing a moisture-absorbing sheet on which the fine fibrous cellulose aggregate is formed, and
The step of attaching the moisture absorbing sheet between members overlapping in the thickness direction of the disposable wear article, and manufacturing a disposable wear article having a ventilation gap between the member and the thin-walled portion.
A method of manufacturing a disposable wearable article, characterized in that.

(Action effect)
When the dispersion liquid of the fine fibrous cellulose is applied to the non-woven fabric and then the dispersion liquid of the coated portion is dried, the volume of the fine fibrous cellulose aggregate gradually decreases as the fine fibrous cellulose aggregate is formed. .. Along with this, the volume of the coated portion of the dispersion liquid of the non-woven fabric is also reduced, and a thin-walled portion is automatically formed. This manufacturing method utilizes this.
For example, a thin-walled portion may be formed on the non-woven fabric to be the moisture-absorbing sheet by embossing, or a fine fibrous cellulose aggregate may be attached to the thin-walled portion thereafter. However, according to this production method, the non-woven fabric to be the moisture-absorbing sheet. A moisture-absorbing sheet can be formed simply by applying a dispersion of fine fibrous cellulose in a desired pattern and drying it.
Further, if the non-woven fabric is coated with the dispersion liquid of fine fibrous cellulose and then attached to other members of the disposable wear article before drying (that is, before the thin-walled portion is formed), the formation of the ventilation gap is not possible. May be sufficient. On the other hand, in this manufacturing method, since the disposable worn article is manufactured using the moisture-absorbing sheet after drying, a good ventilation gap can be formed. Therefore, in this manufacturing method, the cover layer is attached after the thin-walled portion is formed.

According to the present invention, there are advantages such as excellent breathability for allowing moisture to escape and breathability for efficiently supplying moisture to the hygroscopic material.

It is a top view in the unfolded state which shows the inner surface of a tape type disposable diaper. It is a top view in the unfolded state which shows the outer surface of a tape type disposable diaper. FIG. 6 is a sectional view taken along line 6-6 of FIG. It is a cross-sectional view of line 7-7 of FIG. 8-8 is a cross-sectional view taken along the line 8-8 of FIG. 9-9 is a cross-sectional view taken along the line 9-9 of FIG. FIG. 5 is a sectional view taken along line 5-5 of FIG. It is a top view in the unfolded state of a diaper showing a main part. It is a top view in the unfolded state of a diaper showing a main part. It is a top view in the unfolded state of a diaper showing a main part. It is sectional drawing which shows the moisture absorption sheet enlarged. It is a top view which shows various patterns of the thin-walled part (the part where fine fibrous cellulose is attached).

1 to 7 show an example of a tape-type disposable diaper, in which reference numeral W indicates the entire width of the diaper excluding the connecting tape, and reference numeral L indicates the total length of the diaper. The dotted pattern portion shows an adhesive as a joining means for joining each component located on the front side and the back side thereof, and is a solid, bead, curtain, summit or spiral coating of hot melt adhesive, or a pattern coat (relief plate method). The fixed portion of the elastic member is formed by (transferring of the hot melt adhesive) or the like, or by coating the elastic member on the outer peripheral surface of the elastic member such as a comb gun or a sure wrap coating in place of or together with the fixed portion. Examples of the hot melt adhesive include EVA type, adhesive rubber type (elastomer type), olefin type, polyester / polyamide type and the like, but they can be used without particular limitation. As the joining means for joining the constituent members, a means by welding materials such as a heat seal and an ultrasonic seal can also be used.

This tape-type disposable diaper includes an absorber 56, a liquid-permeable top sheet 30 that covers the front side of the absorber 56, a liquid-impermeable resin film 11 that covers the back side of the absorber 56, and a liquid-impermeable resin film. It has an exterior non-woven fabric 12 that covers the back side of the product and constitutes the outer surface of the product. Reference numeral F indicates a ventral portion located on the front side of the center in the front-rear direction, and reference numeral B indicates a dorsal portion located on the rear side of the center in the front-rear direction.

Hereinafter, the materials and characteristic parts of each part will be described in order.
(Absorber)
The absorber 56 is a portion that absorbs and retains the excrement liquid, and can be formed by an aggregate of fibers. The fiber aggregate is a filament aggregate obtained by stacking short fibers such as cotton-like pulp and synthetic fibers, and opening tow (fiber bundle) of synthetic fibers such as cellulose acetate as necessary. Can also be used. The basis weight of fibers, when fiber stacking flocculent pulp or short fibers, for example, be a 100 to 300 g / m ² approximately, in the case of a filament aggregate, for example, be 30 to 120 g / m ² approximately Can be done. In the case of synthetic fibers, the fineness is, for example, 1 to 16 dtex, preferably 1 to 10 dtex, and more preferably 1 to 5 dtex. In the case of a filament aggregate, the filament may be a non-crimped fiber, but is preferably a crimped fiber. The degree of crimping of the crimped fibers can be, for example, 5 to 75 fibers per 2.54 cm, preferably 10 to 50 fibers, and more preferably about 15 to 50 fibers. In addition, uniformly crimped crimped fibers can be used.

(Highly absorbent polymer particles)
The absorber 56 may contain high-absorbent polymer particles in part or all of the absorber 56. The highly absorbent polymer particles include "powder" in addition to "particles". As the highly absorbent polymer particles 54, those used for this kind of absorbent article can be used as they are. The particle size of the highly absorbent polymer particles is not particularly limited, but for example, sieving (shaking for 5 minutes) using a standard sieve (JIS Z8801-1: 2006) of 500 μm, and particles falling under the sieve by this sieving. When sieving (shaking for 5 minutes) using a 180 μm standard sieve (JIS Z8801-1: 2006), the proportion of particles remaining on the 500 μm standard sieve is 30% by weight or less, and the 180 μm standard sieve. It is desirable that the proportion of particles remaining on the top is 60% by weight or more.

The material of the highly absorbent polymer particles can be used without particular limitation, but those having a water absorption of 30 g / g or more are preferable. Highly absorbable polymer particles include starch-based, cellulosic-based and synthetic polymer-based ones, which are starch-acrylic acid (salt) graft copolymers, saponified starch-acrylonitrile copolymers, and crosslinked sodium carboxymethyl celluloses. A substance or an acrylic acid (salt) polymer or the like can be used. As the shape of the highly absorbent polymer particles, a powder or granular material that is usually used is preferable, but other shapes can also be used.

As the highly absorbent polymer particles, those having a water absorption rate of 70 seconds or less, particularly 40 seconds or less are preferably used. If the water absorption rate is too slow, the liquid supplied into the absorber 56 tends to return to the outside of the absorber 56, so-called reversion.

Further, as the highly absorbent polymer particles, those having a gel strength of 1000 Pa or more are preferably used. As a result, even when the bulky absorber 56 is used, the sticky feeling after liquid absorption can be effectively suppressed.

The amount of the highly absorbent polymer particles to be coated can be appropriately determined according to the amount of absorption required for the application of the absorber 56. Therefore, although it cannot be said unconditionally, it can be set to 50 to 350 g / m ² . If the polymer coating amount is less than 50 g / m ² , it becomes difficult to secure the absorption amount. If it exceeds 350 g / m ² , not only the effect is saturated, but also an excess of highly absorbent polymer particles gives a jerky discomfort.

(Packaging sheet)
In order to prevent the highly absorbent polymer particles from coming off or to improve the shape retention of the absorber 56, the absorber 56 can be incorporated as an absorbing element 50 wrapped in the packaging sheet 58. As the packaging sheet 58, tissue paper, particularly crepe paper, non-woven fabric, non-woven fabric of polylami, a sheet having small holes, or the like can be used. However, it is desirable that the sheet does not allow the highly absorbent polymer particles to escape. When a non-woven fabric is used instead of the crepe paper, a hydrophilic SMMS (spunbond / meltblown / meltblown / spunbond) non-woven fabric is particularly preferable, and polypropylene, polyethylene / polypropylene or the like can be used as the material. The fiber texture is preferably 5 to 40 g / m ² , especially 10 to 30 g / m ² .

As shown in FIG. 3, the packaging sheet 58 has a form in which the entire absorber 56 is wrapped by one sheet, or may be formed by wrapping the entire absorber 56 by a plurality of sheets such as two upper and lower sheets. 58 may be omitted.

(Top sheet)
The top sheet 30 has liquid permeability, and for example, a perforated or non-perforated non-woven fabric, a porous plastic sheet, or the like can be used. In addition, the non-woven fabric is not particularly limited as to what the raw material fiber is. For example, olefin-based fibers such as polyethylene and polypropylene, synthetic fibers such as polyester-based and polyamide-based fibers, recycled fibers such as rayon and cupra, natural fibers such as cotton, and mixed fibers and composite fibers in which two or more of these are used. Etc. can be exemplified. Further, the non-woven fabric may be produced by any processing. Examples of the processing method include known methods such as a spunlace method, a spunbond method, a thermal bond method, a melt blown method, a needle punch method, an air through method, and a point bond method. For example, the spunlace method is preferable when flexibility and drapeability are required, and the thermal bond method is preferable when bulkiness and softness are required.

The top sheet 30 extends from the front end to the rear end of the product in the front-rear direction and extends laterally from the absorber 56 in the width direction WD. For example, the starting point of the rising gather 60 described later is more than the side edge of the absorber 56. If it is located on the center side in the width direction, the width of the top sheet 30 can be made shorter than the total width of the absorber 56 as necessary.

(Intermediate sheet)
In order to quickly transfer the liquid that has permeated the top sheet 30 to the absorber, an intermediate sheet (also referred to as a "second sheet") 40 having a faster liquid permeation speed than the top sheet 30 can be provided. The intermediate sheet 40 is for quickly transferring the liquid to the absorber to enhance the absorption performance by the absorber and prevent the phenomenon of "reversion" of the absorbed liquid from the absorber. The intermediate sheet 40 may be omitted.

Examples of the intermediate sheet 40 include the same material as the top sheet 30, spunlace non-woven fabric, spunbonded non-woven fabric, SMS non-woven fabric, pulp non-woven fabric, mixed sheet of pulp and rayon, point-bonded non-woven fabric or crepe paper. In particular, the air-through non-woven fabric is preferable because it is bulky. It is preferable to use a composite fiber having a core-sheath structure for the air-through non-woven fabric. In this case, the resin used for the core may be polypropylene (PP), but polyester (PET) having high rigidity is preferable. Basis weight is preferably ^{17~80g / m 2, 25~60g / m} 2 is more preferable. The thickness of the raw material fiber of the non-woven fabric is preferably 2.0 to 10 dtex. In order to make the non-woven fabric bulky, it is also preferable to use eccentric fibers having no core in the center, hollow fibers, and eccentric and hollow fibers as mixed fibers of all or a part of the raw material fibers.

Although the intermediate sheet 40 of the illustrated example is arranged in the center shorter than the width of the absorber 56, it may be provided over the entire width. Further, 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 position 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, but for example, after kneading an inorganic filler in an olefin-based resin such as polyethylene or polypropylene to form a sheet, the film is uniaxial. Alternatively, a microporous sheet obtained by stretching in the biaxial direction can be preferably used. Needless to say, the liquid-impermeable resin film 11 does not include a non-woven fabric as a base material with improved waterproofness.

It is desirable that the liquid-impermeable resin film 11 extends in the same or wider range as the absorber 56 in the front-rear direction LD and the width direction WD, but if necessary, such as when other impermeable means is present. It is also possible to form a form that does not cover the end portion of the absorber 56 in the front-rear direction LD and the width direction WD.

(Exterior non-woven fabric)
The exterior non-woven fabric 12 covers the entire back side of the liquid-impermeable resin film 11 and gives the outer surface of the product a cloth-like appearance. The exterior non-woven fabric 12 is not particularly limited, and the material fibers include, for example, olefin-based fibers such as polyethylene and polypropylene, synthetic fibers such as polyester-based and polyamide-based, recycled fibers such as rayon and cupra, and natural fibers such as cotton. It can be used, and as a processing method, a spunlace method, a spunbond method, a thermal bond method, an air-through method, a needle punch method, or the like can be used. However, long-fiber non-woven fabrics such as spunbonded non-woven fabrics, SMS non-woven fabrics, and SMMS non-woven fabrics are suitable in terms of both feel and strength. The non-woven fabric can be used alone or in layers. In the latter case, it is preferable to bond the non-woven fabrics to each other with a hot melt adhesive or the like. When a non-woven fabric is used, the fiber texture is preferably 10 to 50 g / m ² , especially 15 to 30 g / m ² .

The exterior non-woven fabric 12 is a member adjacent to the front side by an adhesive such as a hot melt adhesive applied in an appropriate pattern or by welding the material, that is, in the case of the illustrated example, the liquid-impermeable resin film 11 described later or the like. It can be attached to the moisture absorbing sheet 15.

(Get up gather)
In order to prevent excrement that travels laterally along the top sheet 30 and prevent so-called lateral leakage, rising gathers 60 that stand up on the skin side of the wearer are provided on both sides of the surface widthwise WD. Is preferable. Of course, the rising gather 60 can be omitted.

When the rising gather 60 is adopted, its structure is not particularly limited, and any known structure can be adopted. The rising gather 60 of the illustrated example is 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. ing. A water-repellent non-woven fabric can be used as the gather sheet 62, and a rubber thread or the like can be used as the gather elastic member 63. As shown in FIGS. 1 and 2, a plurality of elastic members may be provided, and one elastic member may be provided.

The inner surface of the gather sheet 62 has a joint start end in the width direction on the side portion of the top sheet 30, and the portion outside the width direction from the joint start end is the inner surface of each side flap portion SF, that is, liquid opaque in the illustrated example. It is bonded to the side portion of the sex resin film 11 and the side portion of the exterior nonwoven fabric 12 located outside in the width direction by a hot melt adhesive or the like.

Around the legs, the inside of the rising gather 60 in the width direction from the joint start end is fixed on the top sheet 30 at both ends in the front-rear direction of the product, but the part between them is a non-fixed free part, and this free part is It rises due to the contraction force of the elastic member 63 and comes into close contact with the body surface.

(End flap part, side flap part)
The tape-type disposable diaper of the illustrated example has a pair of end flap portions EF having no absorber 56 extending to the front side and the rear side of the absorber 56, respectively, and extending laterally from both side edges of the absorber 56. It has a pair of side flap portions SF that do not have an absorber 56.

(Plane gather)
A side elastic member 64 made of an elongated elastic member such as rubber thread is fixed to each side flap portion SF in a state of being extended along the front-rear direction LD, whereby the leg circumference portion of each side flap portion SF is fixed. Is configured as a plane gather. As shown in the illustrated example, the leg circumference elastic member 64 is provided between the gather sheet 62 and the liquid-impermeable resin film 11 on the outer side of the joint portion of the gather sheet 62 in the width direction near the joint start end, and also has a side flap. It can also be provided between the liquid-impermeable resin film 11 and the exterior non-woven fabric 12 in the part SF. A plurality of elastic members 64 around the legs may be provided on each side as shown in the illustrated example, or only one elastic member 64 may be provided on each side.

(Connecting tape)
The side flap portion SF in the dorsal side portion B is provided with a connecting tape 13 that is detachably connected to the outer surface of the ventral side portion F. When wearing the diaper 10, the connecting tape 13 is turned from both sides of the waist to the outer surface of the ventral portion F to connect the connecting portion 13A of the connecting tape 13 to an appropriate position on the outer surface of the ventral portion F.

The structure of the connecting tape 13 is not particularly limited, but in the illustrated example, the tape mounting portion 13C fixed to the side flap portion SF, the sheet base material forming the tape main body portion 13B protruding from the tape mounting portion 13C, and this sheet. The base material has a connecting portion 13A with respect to the ventral side provided in the middle portion in the width direction of the tape main body portion 13B, and the tip side from the connecting portion 13A is a knob portion.

As the connecting portion 13A, a hook material (male material) of a mechanical fastener (surface fastener) may be provided, or an adhesive layer may be provided. The hook material has a large number of engaging protrusions on its connecting surface, and the shapes of the engaging protrusions are (A) -shaped, (B) J-shaped, (C) mushroom-shaped, and (D). There are T-shapes, (E) double J-shapes (shapes in which J-shapes are joined back to back), etc., but any shape may be used.

Further, as the sheet base material forming the tape mounting portion 13C to the tape main body portion 13B, a non-woven fabric, a plastic film, a polylami non-woven fabric, paper or a composite material thereof can be used, but the fineness is 1.0 to 3.5 dtex. , A spunbonded non-woven fabric having a texture of 20 to 100 g / m ² and a thickness of 1 mm or less, an air-through non-woven fabric, or a spunlaced non-woven fabric is preferable.

(Target sheet)
It is preferable to provide a target sheet 20 having a target for facilitating the connection at the connection portion of the connection tape 13 in the ventral portion F. When the connecting portion 13A is a hook material, the target sheet 20 can be a target sheet 20 in which a large number of loop threads are provided on the surface of a sheet base material made of a plastic film or a non-woven fabric so that the engaging protrusions of the hook material are entangled. Further, in the case of the pressure-sensitive adhesive layer, one in which the surface of a sheet base material made of a plastic film having a smooth surface, which is highly adhesive, is peeled off can be used. Further, when the connecting portion of the connecting tape 13 on the ventral side portion F is made of a non-woven fabric, for example, when the exterior non-woven fabric 12 is provided as shown in the figure, the target sheet 20 is omitted and the hook material is used as the fiber of the exterior non-woven fabric 12. It can also be entwined and connected. In this case, the target sheet 20 as a mark may be provided between the exterior nonwoven fabric 12 and the liquid-impermeable resin film 11.

(Hygroscopic sheet)
Characteristically, as shown in FIGS. 8 to 10, a moisture absorbing sheet 15 is provided between the liquid-impermeable resin film 11 and the exterior nonwoven fabric 12. If such a moisture-absorbing sheet 15 is provided between the liquid-impermeable resin film 11 and the exterior non-woven fabric 12, the moisture that has permeated the liquid-impermeable resin film 11 is not blocked by the moisture-absorbing sheet 15, so that the moisture-absorbing sheet 15 is attached. The stuffiness prevention property at the time is hard to decrease. Nevertheless, due to the high hygroscopicity of the fine fibrous cellulose aggregate, moisture is retained in the moisture absorbing sheet 15 rather than the exterior non-woven fabric 12 and underwear constituting the outer surface of the product, so that the outer surface of the product and the underwear are less likely to feel damp. ..

In particular, as shown in FIG. 11, the moisture absorbing sheet 15 is a non-woven fabric 16 in which thin-walled portions 16t contracted in the thickness direction are repeatedly formed at intervals, and a fine fibrous cellulose aggregate 17 adhering to the thin-walled portions 16t. It is preferable that the material has. The thin portion 16t may have dents on both the front and back sides of the moisture absorbing sheet 15 as shown in the illustrated example, or may have dents on only one of the front and back sides of the moisture absorbing sheet 15. As a result, although the moisture absorbing sheet 15 is sandwiched between the liquid-impermeable resin film 11 and the exterior nonwoven fabric 12, a ventilation gap 18 is formed between them and the thin portion 16t of the moisture absorbing sheet 15. Will be done. Therefore, in the present moisture absorbing sheet 15, moisture can be released along the surface of the moisture absorbing sheet 15 through the ventilation gap 18. Further, in the process, moisture can be efficiently supplied to the fine fibrous cellulose aggregate 17 which is a hygroscopic material to absorb moisture.

The moisture absorbing sheet 15 may have the fine fibrous cellulose aggregate 17 in addition to the thin portion 16t, but the fine fibrous cellulose aggregate 17 is hard. Therefore, in the moisture absorbing sheet 15, it is preferable that the fine fibrous cellulose aggregate 17 is attached only to the thin portion 16t. As a result, the moisture absorbing sheet 15 can be flexibly deformed except for the thin portion 16t, and the user or the wearer is less likely to touch the hard thin portion 16t, or the hardness is less likely to be transmitted to the skin.

The pattern of the thin portion 16t is not particularly limited as long as it is formed by a pattern that repeats at intervals. For example, the thin-walled portion 16t has a vertical stripe shape in which a plurality of linear thin-walled portions 16t along the front-rear direction LD are arranged at intervals in the width direction WD as shown in FIG. A plurality of linear thin-walled portions 16t along the WD may be arranged in a horizontal stripe shape at intervals in the front-rear direction LD. Further, the thin portion 16t may have a dot shape as shown in FIGS. 12A to 12E, or may have a diagonal grid shape as shown in FIG. 12F. In particular, when the thin portion 16t is provided in a striped or lattice pattern, the continuity of the ventilation gap 18 is increased. Therefore, it is preferable because the breathability for releasing moisture and the breathability for efficiently supplying moisture to the hygroscopic material become further excellent. As described above, when the thin-walled portion 16t is continuously connected in a linear shape, it can be continuous in a straight line or in a curved or wavy line.

The dimensions of the thin portion 16t can be appropriately determined. When the thin-walled portion 16t is arranged in a striped pattern, the line width x1 of the thin-walled portion 16t is preferably 1.0 to 4.0 mm, particularly 2.0 to 3.0 mm, and the distance s1 between adjacent attachment parts is 1. Is preferably 5 to 30 mm, particularly preferably 10 to 20 mm. When the thin-walled portion 16t has a dot-like pattern, the diameter d (the length of the longest portion) of the thin-walled portion 16t is preferably 1.0 to 4.0 mm, particularly preferably 2.0 to 3.0 mm, and has a width. The center (or center of gravity) spacing s2 and s3 of the rows adjacent to the direction WD and the front-rear direction LD are preferably 5 to 25 mm, particularly preferably 15 to 10 mm. When the thin-walled portion 16t is arranged in a grid pattern, the line width x2 of the thin-walled portion 16t is preferably 1.0 to 4.0 mm, particularly 2.0 to 3.0 mm, and the grid spacing s4 (parallel). The distance between the thin portions 16t) is preferably 5 to 30 mm, particularly preferably 10 to 20 mm. The size of the attachment portion of the fine fibrous cellulose aggregate can be the same as the size of the thin portion 16t, or less or more.

The non-woven fabric 16 constituting the moisture absorbing sheet 15 is not particularly limited, but is preferably a short-fiber non-woven fabric having a fineness of ² to 10 dtex and a grain size of 20 to 40 g / m ² because it is bulky and preferably has excellent shapeability. preferable.

In order to improve hygroscopicity, it is best to have a large amount of fine fibrous cellulose, but if it is too large, the product becomes unnecessarily hard. Thus, the content of microfibrillated cellulose in the thin portion 16t is, 0.1 to 5.0 g / m ² approximately, and particularly preferably 0.5 to 3.0 g / m ² approximately.

<Manufacturing method>
For example, the moisture absorbing sheet 15 can be produced by forming a thin-walled portion 16t on the non-woven fabric 16 to be the moisture absorbing sheet 15 by embossing, or by adhering the fine fibrous cellulose aggregate 17 to the thin-walled portion 16t thereafter. ..

Further, the moisture absorbing sheet 15 can be manufactured by the following method. That is, when the dispersion liquid of the fine fibrous cellulose is applied to the non-woven fabric 16 to be the moisture absorbing sheet 15 in a pattern repeated at intervals, the dispersion liquid permeates between the fibers of the non-woven fabric 16. Then, when this is dried, a thin-walled portion 16t is formed in the coated portion of the dispersion liquid, and a fine fibrous cellulose aggregate 17 is formed in the thin-walled portion 16t. That is, when the dispersion liquid of the fine fibrous cellulose is applied to the non-woven fabric 16 and then the dispersion liquid of the coated portion is dried, when the fine fibrous cellulose aggregate 17 is formed, the volume of the fine fibrous cellulose aggregate 17 is formed. Gradually decreases. Along with this, the volume of the coated portion of the dispersion liquid of the nonwoven fabric 16 is also reduced, and the thin-walled portion 16t is automatically formed. This manufacturing method utilizes this. According to this method, the moisture absorbing sheet 15 can be formed only by applying the dispersion liquid of the fine fibrous cellulose to the nonwoven fabric 16 to be the moisture absorbing sheet 15 in a desired pattern and drying it.

However, according to this manufacturing method, if another sheet is attached after the dispersion liquid of the fine fibrous cellulose is applied to the non-woven fabric 16 and before drying (that is, before the thin-walled portion 16t is formed), the ventilation gap 18 may not be formed. Therefore, when the main moisture absorbing sheet 15 and another member are attached, it is desirable to attach the other member after forming the thin portion 16t. For example, the thin portion 16t can be formed in principle by applying a dispersion liquid of fine fibrous cellulose to an existing non-woven fabric 16 member such as the intermediate sheet 40 or the exterior non-woven fabric 12. However, it is not suitable for production on a high-speed production line because it is necessary to attach other members after the dispersion liquid of fine fibrous cellulose is dried. Therefore, as shown in the illustrated example, it is preferable to separately manufacture a dedicated moisture absorbing sheet 15 and attach it between appropriate members to manufacture a disposable wearable article. On the other hand, when the thin portion 16t is formed by embossing, another member can be attached to the non-woven fabric 16 to be the moisture absorbing sheet 15 before the dispersion liquid of the fine fibrous cellulose is applied.

When the attachment portion of the fine fibrous cellulose aggregate 17 is formed by applying the fine fibrous cellulose dispersion, the concentration (mass / volume) of the fine fibrous cellulose dispersion is preferably 0.1 to 10%. , 1.0 to 5.0% is more preferable, and 1.5 to 3.0% is particularly preferable.

The B-type viscosity (60 rpm, 20 ° C.) of the fine fibrous cellulose dispersion is, for example, 700 cps or less, preferably 200 cps or less, and more preferably 50 cps or less. By keeping the B-type viscosity of the fine fibrous cellulose dispersion low in this way, the fine fibrous cellulose can be uniformly applied to the non-woven fabric.

In addition to spraying on the target surface, a transfer method such as a letterpress method can be used to apply the fine fibrous cellulose dispersion.

Pulp fibers that can be used for producing fine fibrous cellulose include chemical pulps such as broadleaf pulp (LBKP) and coniferous pulp (NBKP), bleached thermomechanical pulp (BTMP), stone ground pulp (SGP), and pressurized stone ground. Pulp (PGW), Refiner Gland Pulp (RGP), ChemiGrand Pulp (CGP), Thermogrand Pulp (TGP), Gland Pulp (GP), Thermomechanical Pulp (TMP), Chemithermo Mechanical Pulp (CTMP), Refiner Mechanical Pulp From machine pulp such as (RMP), brown waste paper, kraft envelope blind paper, magazine waste paper, newspaper waste paper, leaflet waste paper, office waste paper, cardboard waste paper, top white waste paper, Kent waste paper, imitation waste paper, ground ticket waste paper, sashimi waste paper, etc. Examples thereof include used paper pulp produced and deinked pulp (DIP) obtained by deinking waste paper pulp. These may be used alone or in combination of a plurality of types as long as the desired effect is not impaired. Further, the pulp fiber obtained by subjecting the pulp fiber to a chemical treatment such as carboxymethylation may be used.

Examples of the method for producing fine fibrous cellulose include mechanical methods such as a high-pressure homogenizer method, a microfluidizer method, a grinder grinding method, a bead mill freeze pulverization method, and an ultrasonic defibration method, but the method is limited to these methods. It's not a thing. Further, microfibration is promoted by a combination of TEMPO oxidation treatment, phosphoric acid esterification treatment, acid treatment and the like.

<Others>
The moisture absorbing sheet 15 can be used alone or can be attached to other parts of the disposable wear article. At the time of use, a non-breathable member or a poorly breathable member may be adjacent to either one or both of the front and back sides of the moisture absorbing sheet 15, a breathable material may be adjacent to both the front and back sides, or one of the front and back sides. There may be no member adjacent to.

For example, as shown in FIG. 9, a moisture absorbing sheet 15 may be provided between the members in the waist portion or the like, or as shown in FIG. 10, the back side of the target sheet 20 (for example, between the target sheet 20 and the exterior non-woven fabric 12). , The moisture absorbing sheet 15 can be provided between the exterior non-woven fabric 12 and the liquid-impermeable resin film 11).

In particular, in order to prevent stuffiness during wearing, the portion adjacent to the back side of the breathable skin contact layer in contact with the wearer's skin may be provided (the whole may be adjacent to the back side of the skin contact layer). When the moisture absorbing sheet 15 is provided, stuffiness can be prevented by efficiently absorbing the moisture inside the disposable worn article at the time of wearing or letting it escape to the outside. For example, in the example shown in FIG. 9, when the moisture absorbing sheet 15 is provided on the waist portion, the area between the absorber 56 and the liquid impermeable resin film 11 is extended between the top sheet 30 and the liquid impermeable resin film 11. A moisture absorbing sheet 15 can be provided.

<Explanation of terms in the specification>
The following terms in the specification have the following meanings unless otherwise specified in the specification.

-The "front-back direction" means the direction indicated by the symbol LD in the figure (vertical direction), and the "width direction" means the direction indicated by WD (horizontal direction) in the figure, and the front-back direction and the width direction. Are orthogonal.

-The "MD direction" and "CD direction" mean the flow direction (MD direction) in the manufacturing equipment and the lateral direction (CD direction) orthogonal to this, and one of them is the front-rear direction depending on the part of the product. And the other is in the width direction. The MD direction of the non-woven fabric is the direction of fiber orientation of the non-woven fabric. The fiber orientation is the direction along which the fibers of the non-woven fabric follow. For example, the measurement method according to the fiber orientation test method based on the zero-distance tensile strength of the TAPPI standard method T481 or the fibers based on the tensile strength ratio in the front-rear direction and the width direction. It can be discriminated by a simple measuring method for determining the orientation direction.

-The "front side" means the one closer to the wearer's skin when worn, and the "back side" means the one farther from the wearer's skin when worn.

-The "front surface" means the surface of the member that is closer to the wearer's skin when worn, and the "back surface" means the surface of the member that is farther from the wearer's skin when worn. ..

-"Elongation rate" means a value when the natural length is 100%. For example, an elongation rate of 200% is synonymous with an elongation ratio of 2 times.

-"Gel strength" is measured as follows. Artificial urine (urea: 2 wt%, sodium chloride: 0.8 wt%, calcium chloride dihydrate: 0.03 wt%, magnesium sulfate heptahydrate: 0.08 wt%, and ion-exchanged water: 97.09 wt% Add 1.0 g of highly absorbent polymer to 49.0 g (mixed product) and stir with a stirrer. The produced gel is left in a constant temperature and humidity chamber at 40 ° C. × 60% RH for 3 hours, then returned to room temperature, and the gel strength is measured with a card meter (Curdmeter-MAX ME-500 manufactured by I. techno Engineering).

-"Grandming" is measured as follows. After pre-drying the sample or test piece, leave it in a test room or device under standard conditions (test location: temperature 23 ± 1 ° C., relative humidity 50 ± 2%) to bring it to a constant weight. Pre-drying refers to constant weight of a sample or test piece in an environment at a temperature of 100 ° C. It is not necessary to pre-dry the fibers having an official moisture content of 0.0%. A sample having a size of 100 mm × 100 mm is cut out from the test piece in a constant weight state using a sampling template (100 mm × 100 mm). The weight of the sample is measured and multiplied by 100 to calculate the weight per square meter, which is used as the index.

-The "thickness" is automatically measured using an automatic thickness measuring device (KES-G5 handy compression measurement program) under the conditions of a load of 0.098 N / cm ² and a pressurized area of 2 cm ² . The thickness of the perforated non-woven fabric is measured at a portion other than the holes and the protrusions around them.

-The water absorption amount is measured by JIS K7223-1996 "Water absorption amount test method for highly water-absorbent resin".

-The water absorption rate shall be the "time to the end point" when JIS K7224-1996 "Water absorption rate test method for superabsorbent polymer" was performed using 2 g of superabsorbent polymer and 50 g of physiological saline. ..

"Microfibrous cellulose" refers to fine cellulose fibers or bundles thereof taken out from plants such as pulp, and generally refers to fibrous cellulose having an average fiber width of nano size (1 to 1000 nm or less), and is an average fiber. Those having a width (median diameter) of 100 nm or less (generally called cellulose nanofibrils (CNF)) are preferable, and those having a width (median diameter) of 10 to 60 nm are particularly preferable.

The "average fiber width" of the fine fibrous cellulose can be measured by the following method. That is, first, 100 ml of an aqueous dispersion of fine fibrous cellulose having a solid content concentration of 0.01 to 0.1% by mass is filtered through a membrane filter made of Teflon (registered trademark), once with 100 ml of ethanol, and with 20 ml of t-butanol. Replace with solvent 3 times. Next, it is freeze-dried and coated with osmium to prepare a sample. This sample is observed by an electron microscope SEM image at a magnification of 5000 times, 10000 times, or 30000 times (in this example, a magnification of 30000 times) depending on the width of the constituent fibers. Specifically, two diagonal lines are drawn on 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 intersecting with these three straight lines are visually measured. Then, the median diameter (median diameter) of the measured value is taken as the average fiber width.

-"Unfolded state" means a state in which the unfolded state is flat without shrinkage or slack.

-Unless otherwise specified, the dimensions of each part mean the dimensions in the unfolded state, not in the natural length state.

-If there is no description about the environmental conditions in the test or measurement, the test or measurement shall be performed in a test room or equipment under standard conditions (test location: temperature 23 ± 1 ° C, relative humidity 50 ± 2%). To do.

The present invention can be applied to all disposable diapers such as pants-type disposable diapers and pad-type disposable diapers, in addition to tape-type disposable diapers as in the above example, and can be applied to other absorbent articles such as sanitary napkins. Needless to say, it can also be applied.

11 ... Liquid impermeable resin film, 12 ... Exterior non-woven fabric, 13 ... Connecting tape, 13A ... Connecting part, 13B ... Tape body part, 13C ... Tape mounting part, 15 ... Moisture absorbing sheet, 16 ... Non-woven fabric, 16t ... Thin-walled part, 17 ... microfibrous cellulose aggregate, 18 ... gap, 20 ... target sheet, 30 ... top sheet, 40 ... intermediate sheet, 50 ... absorbent element, 56 ... absorber, 58 ... packaging sheet, 60 ... rising gather, 62 ... Gathered sheet, B ... dorsal part, F ... ventral part, WD ... width direction, LD ... front-back direction.

Claims (7)

A non-woven fabric in which thin-walled parts contracted in the thickness direction are repeatedly formed at intervals,
It has a fine fibrous cellulose aggregate adhering to the thin wall portion.
A moisture-absorbing sheet that is characterized by this. It does not have the fine fibrous cellulose aggregate other than the thin-walled portion.
The moisture absorbing sheet according to claim 1. The thin-walled portions are provided in a striped or lattice pattern.
The moisture absorbing sheet according to claim 1 or 2. The non-woven fabric constituting the moisture absorbing sheet is a short-fiber non-woven fabric having a fineness of ² to 10 dtex and a grain size of 20 to 40 g / m ² .
The amount of the fine fibrous cellulose aggregate adhered to the thin-walled portion is made of fine fibrous cellulose of 0.1 to 5.0 g / m ² .
The moisture absorbing sheet according to claim 1 or 2. Absorbent and
A breathable liquid-impermeable resin film provided on the back side of the absorber, and
An exterior non-woven fabric that covers the back surface of the liquid-impermeable resin film,
In disposable wear items with
It has a moisture-absorbing sheet provided between the liquid-impermeable resin film and the exterior non-woven fabric.
The moisture absorbing sheet has a non-woven fabric in which thin-walled portions contracted in the thickness direction are repeatedly formed at intervals, and a fine fibrous cellulose aggregate adhering to the thin-walled portions.
A ventilation gap is provided between the exterior non-woven fabric and the thin-walled portion and between the liquid-impermeable resin film.
Disposable wear goods characterized by that. A breathable skin contact layer that touches the wearer's skin,
It has a moisture absorbing sheet provided so as to have a portion adjacent to the back side of the skin contact layer.
The moisture absorbing sheet has a non-woven fabric in which thin-walled portions contracted in the thickness direction are repeatedly formed at intervals, and a fine fibrous cellulose aggregate adhering to the thin-walled portions.
Each has a ventilation gap between the skin contact layer and the thin-walled portion.
Disposable wear goods characterized by that. The dispersion liquid of fine fibrous cellulose is applied to the non-woven fabric in a pattern that repeats at intervals, and the dispersion liquid is dried to form the thin-walled portion in the coated portion of the dispersion liquid and to the thin-walled portion. A step of manufacturing a moisture-absorbing sheet on which the fine fibrous cellulose aggregate is formed, and
The step of attaching the moisture absorbing sheet between members overlapping in the thickness direction of the disposable wear article, and manufacturing a disposable wear article having a ventilation gap between the member and the thin-walled portion.
A method of manufacturing a disposable wearable article, characterized in that.

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