JP2955222B2 - Body fluid absorbent articles - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

TECHNICAL FIELD The present invention relates to a sanitary napkin,
The present invention relates to a bodily fluid absorbent article such as a hygiene pad, a disposable diaper, a medical pad, and a breast milk pad, and more particularly, to a bodily fluid absorbent article comprising an absorbent sheet having no high-absorbent polymer falling off and having high absorption performance. It is about.

[0002]

2. Description of the Related Art
An absorbent in a body fluid absorbent article such as a sanitary napkin or a disposable diaper is mainly composed of fluff pulp, absorbent paper and superabsorbent polymer. In particular, the superabsorbent polymer has a large absorption capacity and has the property of solidifying the bodily fluid once absorbed into a gel so that it does not leak out.
At present, it is used in most body fluid absorbent articles.

[0003] However, while the superabsorbent polymer has such properties, since its shape is powdery,
There is a technical problem that it is easy to fall off (the superabsorbent polymer leaks from the body fluid absorbent article). In addition, there is a problem that it is desired to further increase the absorption capacity of the superabsorbent polymer. In particular, since falling off of the superabsorbent polymer is a fatal problem in product performance including absorption, various techniques for preventing the falling off (immobilization) have been proposed.

For example, US Pat. No. 3,070,095 discloses a superabsorbent polymer 16 as shown in FIG.
Is spread on a tissue 30, another tissue 31 is laminated thereon, and then the superabsorbent polymer is pressed into the tissue by pressing with a roller. However, in this method, the superabsorbent polymer is only fixed in layers between the tissue layers,
Large amounts of superabsorbent polymers cannot be fixed. Therefore, when such an absorbent sheet is used, for example, as an absorbent for a bodily fluid absorbent article, the highly absorbent 16 polymer is separated from the tissues 30 and 31 by the movement of the wearer or the like, and the tissue 30 and 31 are separated. In some cases, a space may be created in which the liquid may stay.

US Pat. No. 3,670,731 discloses that after spraying a superabsorbent polymer between two paper layers,
It discloses embossing or quilting to hold the superabsorbent polymer in place. However, this method also has the same drawbacks as the above-described roller compression method.

Further, Japanese Patent Publication No. 59-26767, Japanese Patent Application Laid-Open No. 54-123293 and Japanese Patent Application Laid-Open No. 54-141
No. 099 discloses that, after spraying steam or spraying water on a tissue to moisten the tissue, a high-absorbency polymer is sprayed, and the high-absorbency polymer is provided with tackiness, so that the tissue is interposed between the tissues. It is disclosed to fix superabsorbent polymers. Further, as shown in FIG. 7, in the sanitary napkin 100, after water is sprayed on the fluff pulp 2a, the superabsorbent polymer 2e is placed thereon.
Is also used, and an absorbent sheet 2b is superimposed thereon, and further, these are covered with an absorbent sheet 2c to integrate them. According to these methods, although the superabsorbent polymer can be fixed to some extent, dropping cannot be completely prevented, and the fixing amount is still insufficient. In addition, when a body fluid is absorbed, the superabsorbent polymer swells in a layer, and in some cases, absorption may be inhibited by gel blocking or the like.

[0007] Further, Japanese Patent Application Laid-Open No. 61-132697 discloses
In the papermaking process, a highly absorbent poly
After spraying the
A method for producing absorbent paper containing
You. According to this method, a certain amount of superabsorbent polymer
Can be fixed in paper, but the fixed amount is at most 10 g / m
^TwoDegree, and it is not enough. Also,
In the absorbent sheet that has been treated,
Because of the presence of superabsorbent polymer,
The absorptive polymer is driven by dynamic actions such as friction
It has the disadvantage of easily falling off.

Further, a method is also known in which a hot-melt adhesive is applied to the entire surface of a tissue or the like, and the superabsorbent polymer is fixed by the adhesive. According to this method, the superabsorbent polymer can be reliably fixed. However, since most of the surface of the superabsorbent polymer is covered with the hot melt adhesive, swelling inhibition of the superabsorbent polymer and absorption inhibition of the body fluid occur.

As another method of immobilizing a superabsorbent polymer using a hot melt adhesive, there is a method of applying a hot melt adhesive in a spiral shape. According to this method, the swelling inhibition and the absorption inhibition are small, and the highly absorbent polymer can be fixed efficiently. However, applying the hot melt adhesive spirally complicates the manufacturing process and equipment. Furthermore, since a large amount of superabsorbent polymer is immobilized in a layer, gel blocking of the superabsorbent polymer occurs when bodily fluid is absorbed, and swelling of the liquid is inhibited.

[0010] On the other hand, an absorbent sheet using wood pulp produced by a dry method is also known. In such an absorbent sheet, if an attempt is made to increase the sheet strength by using a chemical binder, a high content synthetic pulp, a low melting point synthetic fiber, or the like, the absorbent sheet becomes hydrophobic and the absorption rate is reduced. When the sheet strength is low, there is a disadvantage that when absorbing liquid, the superabsorbent polymer swells and breaks the absorbent sheet to protrude outward. In addition, crepe paper may be laminated in order to increase the surface strength of the absorbent sheet, but in this case, there is a problem that the cost is increased.
In addition, in each case, the superabsorbent polymer is insufficiently fixed to the wood pulp, and the problem that the superabsorbent polymer is likely to fall off is not improved. Further, there is a problem that when the absorbent sheet is strongly compressed, the liquid absorption rate is unavoidably reduced.

In addition to the above-mentioned absorbent sheet, there is also known a method in which a superabsorbent polymer is directly polymerized on a nonwoven fabric serving as a base material and fixed on the nonwoven fabric to obtain an absorbent sheet. However, when a nonwoven fabric composed of hydrophilic fibers is used as the nonwoven fabric, the superabsorbent polymer obtained as a result of the polymerization does not become particles but is fixed almost uniformly to the entire nonwoven fabric, so that the liquid absorption amount However, there is a drawback that is reduced. On the other hand, when a nonwoven fabric made of hydrophobic fibers is used as the nonwoven fabric, unlike the nonwoven fabric made of the above hydrophilic fibers, the superabsorbent polymer obtained as a result of polymerization becomes particulate, Has the disadvantage that the liquid absorption rate is low because of its hydrophobicity. Moreover, in these methods, the unreacted monomer remains unavoidable, so that the use of the absorbent sheet is limited from the viewpoint of safety of the monomer to the human body.

Further, US Pat. Nos. 4,605,402 and 5,021,050 and the like disclose a method in which a fibrous layer is superimposed on a fibrous web on which a superabsorbent polymer is sprayed. Further, there is disclosed an absorber in which a highly absorbent polymer is dispersed and adhered to a fiber in a central portion in a thickness direction. Although these absorbers are compressed and thinned at the time of manufacture, they are not sheeted and are still thick for use in various applications. In addition, since the density is low, the surface absorbability is weak. Furthermore, when a liquid is absorbed and wetted, the elasticity of the synthetic fiber is used to recover the original thickness in order to obtain an absorption space, which is insufficient for reducing the thickness of the body fluid absorbent article.

[0013] Accordingly, an object of the present invention is to provide an absorbent sheet to be used as an absorbent layer, which is a thin absorbent sheet in the form of paper in which the superabsorbent polymer is securely fixed without impairing the original absorption characteristics of the superabsorbent polymer. It is an object of the present invention to provide a bodily fluid absorbent article provided with an absorbent sheet.

It is another object of the present invention to provide a body fluid absorbent article in which the superabsorbent polymer does not cause gel blocking even when the body fluid is repeatedly absorbed, and can exhibit the original absorption characteristics of the superabsorbent polymer. It is in.

A further object of the present invention is to provide a body fluid-absorbing article which is extremely thin, has excellent wearing feeling, and does not cause discomfort even after absorbing the liquid.

[0016]

Means for Solving the Problems As a result of intensive studies, the present inventors have found that the fibers constituting the absorbent sheet in the body fluid absorbent article are wet in a space formed between the fibers. By burying the absorbent polymer, gel blocking of the super absorbent polymer can be effectively prevented,
It has also been found that a large amount of superabsorbent polymer can be immobilized.

The present invention has been made based on the above findings. In a body fluid absorbent article having at least a body fluid retaining absorbing layer and a body fluid impermeable leak-proof layer, the absorbent layer has at least a hydrophilic property. An absorbent sheet comprising fibers and a hot-melt adhesive fiber or paper strength agent and a superabsorbent polymer; said absorbent sheet comprising a fiber aggregate and a fiber web
And the fiber aggregate and the fiber web
And the fiber aggregate is the absorbent sheet
It has an absorbing surface that absorbs bodily fluids and on the absorbing surface side
Does not contain the superabsorbent polymer , the fiber web is
Is formed from at least the hydrophilic fibers, the superabsorbent polymer is not present in the absorption surface, mainly on
It is dispersed and arranged in the fiber web, and is adhered and fixed to the hydrophilic fibers constituting the absorbent sheet; the basis weight of the superabsorbent polymer to be sprayed is 5 to 300 g / m ^2.
The above object has been attained by providing a body fluid absorbent article characterized in that the absorbent sheet is constituted by an absorbent sheet having a thickness of 0.3 to 1.5 mm.

The present invention also relates to a body fluid absorbent article comprising at least a body fluid retaining absorbent layer and a body fluid impermeable leak-proof layer, wherein the absorbent layer comprises a bulky hydrophilic fiber and a hot-melt adhesive. Formed from fibers or paper strength agents , fibers
Integrally composed mainly of web and fiber aggregate
An absorbent sheet comprising a fibrous structure , which is a sheet-like material of fibers, and superabsorbent polymer particles, wherein the superabsorbent polymer particles are present on an absorbent surface where the absorbent sheet absorbs bodily fluids. Without being dispersed and fixed in the fiber structure, the thickness of the absorbent sheet is 0.3 to 1.5 m
m, and the spray basis weight of the superabsorbent polymer is 20 to 7
The absorbent article is constituted by an absorbent sheet having a weight of 0 g / m ² , and provides an absorbent article characterized in that the absorbent article does not have a sense of incongruity due to absorption and swelling of the body fluid during use.

In the present specification, “fiber web” means
In the wet state before spraying the superabsorbent polymer, the constituent fibers are not restrained at all or are very slightly restrained by mechanical entanglement and frictional force, and have a very high degree of freedom. And, after the drying, the constituent fibers are strongly constrained to each other and mean an aggregate of fibers in a sheet-like form, and the “fiber aggregate” is formed mainly of fibers, and is formed in a sheet-like form. In addition to ordinary paper, nonwoven fabric and woven fabric, the above-mentioned fiber web is also included, and the `` fibrous structure '' is the above-mentioned fiber web and the above-mentioned fiber assembly. Means a sheet-like material of fibers integrally configured with

[0020]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of the body fluid absorbent article of the present invention will be described below with reference to the drawings. In addition,
In the following description, a sanitary napkin is taken as an example of a body fluid absorbent article, but the present invention is similarly applicable to other body fluid absorbent articles such as a hygiene pad, a disposable diaper, a medical pad, and a breast milk pad. Can be. Also,
As long as it does not deviate from the requirements of the present invention, the constituent materials and the manufacturing method of the body fluid absorbent article can be freely modified within the scope of the prior art.

First, a preferred embodiment of the body fluid absorbent article of the present invention will be described with reference to FIGS.
Here, FIG. 1 is a schematic view showing a cross section in the width direction of a sanitary napkin as a first preferred embodiment of the body fluid absorbent article of the present invention. FIGS. 2 to 6 are schematic views (corresponding to FIG. 1) showing a cross section in the width direction of a sanitary napkin as another preferred embodiment of the body fluid absorbent article of the present invention.

The first of the body fluid absorbent articles of the present invention shown in FIG.
The sanitary napkin 100 as a preferred embodiment of the
It comprises a surface layer 1 capable of absorbing body fluid, a leak-proof layer 3 that is impermeable to body fluid, and an absorbent layer 2 that retains body fluid and is interposed between the surface layer and the leak-proof layer.

More specifically, the sanitary napkin 100
Is substantially vertically elongated, and when the sanitary napkin is worn, the surface layer 1 is located on the side in contact with the skin, and the leak-proof layer 3 is located on the side in contact with the underwear.

As described later, the absorbent layer 2 includes an absorbent sheet 10, fluff pulp 2a,
And an absorbent paper 2b covering the fluff pulp 2a. The leak-proof layer 3 covers the side surface and the bottom surface of the absorption layer 2. The surface layer 1 covers all surfaces of the combined body of the absorption layer 2 and the leakage prevention layer 3.

The surface layer 1 is not particularly limited as long as it can transmit a body fluid to the absorption layer 2, but is preferably a material having a feeling similar to underwear.
Examples of such a surface layer include, for example, a woven fabric, a nonwoven fabric, and a porous film of a thermoplastic resin. In particular, an apertured film made of a polyolefin such as low-density polyethylene can be preferably used.

The leak-proof layer 3 is not particularly limited as long as it is impermeable to bodily fluids, but preferably has moisture permeability and a feeling close to underwear. The body fluid impermeable leakproof layer having moisture permeability is, for example, a thermoplastic resin to which a filler of an inorganic compound or an organic compound is added,
It can be obtained by melt extruding from a T-die or a circular die to form a film, and then uniaxially or biaxially stretching the film.

On the side in contact with the undergarment of the sanitary napkin 100, two adhesive portions 4, 4 are formed in a streak shape in the longitudinal direction, and the adhesive portions 4, 4 are separated before use. Paper 5
Protected by Further, in FIG.
Is a joint for joining the above members. In addition, other points that are not described in detail are configured similarly to the conventional sanitary napkin.

Next, the characteristic portion of the body fluid absorbent article of the first embodiment will be described. The sanitary napkin 100 as the body fluid absorbent article according to the first embodiment includes the body fluid retaining absorbent layer 2. The absorbent layer 2 is an absorbent sheet containing at least a hydrophilic fiber and a hot-melt adhesive fiber or a paper-strengthening agent and a superabsorbent polymer; the absorbent sheet comprises a fiber aggregate and a fiber web.
And the fiber aggregate and the fiber web
And the fiber aggregate is the absorbent sheet
It has an absorbing surface that absorbs bodily fluids and on the absorbing surface side
Does not contain the superabsorbent polymer , the fiber web is
Is formed from at least the hydrophilic fibers, the superabsorbent polymer is not present in the absorption surface, mainly on
It is dispersed and arranged in the fiber web, and is adhered and fixed to the hydrophilic fibers constituting the absorbent sheet; the basis weight of the superabsorbent polymer to be sprayed is 5 to 300 g / m ^2.
The absorbent sheet is composed of an absorbent sheet having a thickness of 0.3 to 1.5 mm.

By using such an absorbent sheet, it is possible to obtain a body fluid-absorbing article free from dropout of superabsorbent polymer and gel blocking. Moreover, such an absorbent sheet has the functions of absorbing, transmitting and diffusing body fluids and retaining body fluids in its single structure, and thus has the above-mentioned functions as a conventional body fluid absorbent article. Since there is no need to combine members, an extremely thin body fluid absorbent article can be obtained. The thickness of the body fluid absorbent article is the thickness of the absorbent sheet (0.3 to 1.5 mm).
And a thickness (0.2 to 1.0 mm) of a surface layer, a leak-proof layer, and the like, and are extremely thin. The details of the absorbent sheet will be described later.

The first of the body fluid absorbing articles of the present invention shown in FIG.
According to a preferred embodiment of the present invention, the body fluid is absorbed into the sanitary napkin 100 through the surface layer 1. Thereafter, the light is transmitted through the fluff pulp 2a, and is absorbed and held by the superabsorbent polymer dispersed in the absorbent sheet 10. In this case, the absorbent sheet 10, the fiber aggregate having the absorbent surface arranged so as to be located on the side of the surface layer 1. By arranging the absorbent sheet 10 in this manner, a favorable effect that the body fluid absorbed by the fluff pulp 2a is more smoothly guided to the absorbent sheet 10 can be obtained.

As will be described later, the absorbent sheet 10
Since the superabsorbent polymer is securely fixed without impairing the original absorption characteristics of the superabsorbent polymer,
Sanitary napkin 10 including the absorbent sheet 10
A value of 0 indicates that the body fluid holding capacity is large. Moreover, since the sanitary napkin 100 shown in FIG. 1 includes the fluff pulp 2a in addition to the absorbent sheet 10, the body fluid holding capacity is further increased. Therefore, the bodily fluid absorbent article of the present embodiment is suitable as a nighttime sanitary napkin worn for a long time.

Next, FIGS. 2 to 6 show second to sixth preferred embodiments of the body fluid absorbent article of the present invention. The second
In the sixth to sixth embodiments, the same points as those in the first embodiment are not described in detail, but the description in the first embodiment is applied as appropriate. 2 to 6, the same members as those in FIG. 1 are denoted by the same reference numerals.

The second embodiment of the body fluid absorbent article of the present invention shown in FIG.
In the sanitary napkin 100 as a preferred embodiment of the present invention, the absorbent layer is composed only of the absorbent sheet 10, and the side surface and the bottom surface of the absorbent sheet 10 are covered with the leak-proof layer 3. . The surface layer 1 covers all surfaces of the combination of the absorbent sheet 10 and the leak-proof layer 3. Also in this embodiment, as in the first embodiment, the absorbent sheet 10, the fiber aggregate having the absorbent surface arranged so as to be located on the side of the surface layer 1.

The sanitary napkin 100 has a small number of members and each member is thin, so that an extremely thin sanitary napkin can be obtained.
Furthermore, since the superabsorbent polymer is securely fixed to the absorbent sheet 10 without impairing the original absorption characteristics of the superabsorbent polymer, the body fluid has a large holding capacity despite its thinness. As a result, a sanitary napkin having a comfortable wearing feeling and a large body fluid holding capacity can be obtained.

The third embodiment of the body fluid absorbent article of the present invention shown in FIG.
In the sanitary napkin 100 as a preferred embodiment of the present invention, the absorbent layer is composed of only the absorbent sheet 10, and the absorbent sheet 10 is bent in a C shape. The side and bottom surfaces of the absorbent sheet 10 are covered with the leak-proof layer 3. Furthermore, the surface layer 1 covers all surfaces of the combination of the absorbent sheet 10 and the leak-proof layer 3. In the present embodiment, the absorbent sheet 10, the fiber aggregate having the absorbent surface place bent so as to be positioned on the side of the surface layer 1.

The sanitary napkin 100 is thicker than the sanitary napkin shown in FIG. 2 by the amount that the absorbent sheet 10 is bent in a C-shape.
The absorbent layer 2 can be made thinner than the sanitary napkin shown in FIG. 1 using fluff pulp. Moreover, since the absorbent sheet 10 is bent in a C-shape, the holding capacity of the bodily fluid is large. As a result, a sanitary napkin having a comfortable wearing feeling and a large body fluid holding capacity can be obtained.

The fourth embodiment of the body fluid absorbent article of the present invention shown in FIG.
In the sanitary napkin 100 as a preferred embodiment of the present invention, the absorbent layer includes the absorbent sheets 10, 10,.
Are stacked (three in FIG. 4).
Then, the absorbent sheets 10, 10,...
The side surface and the bottom surface are covered with the leakage prevention layer 3. Further, the absorbent sheets 10, 10,.
The surface layer 1 covers all the surfaces of the combination of the above and the leak-proof layer 3. Also in this embodiment, as in the first embodiment, the absorbent sheet 10, the fiber aggregate having the absorbent surface arranged so as to be located on the side of the surface layer 1.

Although the sanitary napkin 100 is thicker than the sanitary napkin shown in FIG. 2 because of the plurality of the absorbent sheets 10 stacked on each other, it is still possible to use fluff pulp for the absorbent layer 2. 1 can be thinner than the sanitary napkin shown in FIG. In addition, since a plurality of the absorbent sheets 10 are stacked, the body fluid holding capacity is large. As a result, a sanitary napkin having a comfortable wearing feeling and a large body fluid holding capacity can be obtained.

The fifth embodiment of the body fluid absorbent article of the present invention shown in FIG.
In the sanitary napkin 100 as a preferred embodiment of the present invention, the absorbent sheet 10 functions as both a surface layer capable of absorbing body fluid and an absorbent layer capable of retaining body fluid. That is, the sanitary napkin 100 of the present embodiment is provided with the absorbent sheet 10 in which a surface layer capable of absorbing body fluid and an absorbent layer that retains body fluid are integrated.
Are covered with the leak-proof layer 3. In the present embodiment, the absorbent sheet 10, arranged to be positioned on the side fiber aggregate having the absorbent surface is in contact with the skin.

In the sanitary napkin 100, the number of constituent members is reduced, and the thickness can be further reduced. As a result, a sanitary napkin that has a comfortable wearing feeling and can be manufactured with a simple process and at low cost is obtained.

The sixth embodiment of the body fluid absorbent article of the present invention shown in FIG.
In the sanitary napkin 100 as a preferred embodiment of the present invention, the absorbent sheet has a surface layer capable of absorbing body fluid,
It also has the three functions of a body fluid retaining absorption layer and a body fluid impermeable leakproof layer. That is, the sanitary napkin 100 of the present embodiment is formed by integrating a surface layer capable of absorbing body fluid, an absorption layer capable of retaining body fluid, and a leakproof layer impermeable to body fluid. More specifically, it comprises the absorbent sheet 10 and a humor-impermeable sheet 3 'joined and integrated with the surface of the absorbent sheet opposite to the surface that absorbs humor. In the present embodiment, the absorbent sheet 10, Ru is arranged so as to be positioned on a side where the fiber aggregate having the absorbent surface to absorb body fluids. In addition, it is particularly preferable to bond the body fluid-impermeable sheet 3 'to the surface opposite to the absorbing surface.

In the sanitary napkin 100, the number of constituent members is reduced, and the thickness can be further reduced. As a result, a sanitary napkin that has a more comfortable wearing feeling and that can be manufactured with a simpler process at a low cost is obtained. In addition, the body fluid-absorbent article of the present embodiment has a sanitary napkin as shown in FIG.
It is also suitable as a bodily fluid absorbent article such as a breast milk pad or a hygiene pad that absorbs a small amount of bodily fluid.

Next, the absorbent sheet used in the body fluid absorbent article of the present invention will be described in detail with reference to the drawings. Here, FIG. 8 is a schematic diagram showing a cross section of the absorbent sheet, and FIG. 9 is a schematic diagram showing a cross section of a preferable absorbent sheet.

As shown in FIG. 8, the absorbent sheet 10 contains at least a hydrophilic fiber and a hot-melt adhesive fiber or a paper strength reinforcing agent, and a superabsorbent polymer 16.
Further, the absorbent sheet 10 has an absorbent surface 12 for absorbing body fluid, the absorbent surface 12 does not have the superabsorbent polymer 16, and the superabsorbent polymer 16 is Distributed inside. The superabsorbent polymer 16 is adhered to the hydrophilic fibers constituting the absorbent sheet 10.

The absorbent sheet 10 is described in detail
Is composed of a fiber aggregate 15 and a fiber web 18, as shown in FIG. The fiber assembly 15 has the absorbent surface 12 and does not include the superabsorbent polymer 16 on the absorbent surface 12 side. On the other hand, the fiber web 1
8 is made of at least a hydrophilic fiber. Further, as shown in FIG. 9, the fiber aggregate 15 and the fiber web 18 are integrated. Further, the superabsorbent polymer 16 is mainly disposed inside the fiber web 18.

[0046] Thus, the absorbent sheet 1 0, the fiber assembly 15 and the fiber web 18 superabsorbent polymer 16 and includes has a unitary structure contained therein is characterized by one One. More specifically, the absorbent sheet 10 has a mechanical entanglement between fibers constituting the fiber aggregate 15 and fibers constituting the fiber web 18, hydrogen bonding (and a paper strength reinforcing agent), and thermal fusion. The fiber aggregate 15 and the fiber web 18 are integrated by attachment or the like. By having such a structure, the superabsorbent polymer 16 is securely fixed inside the absorbent sheet, and can be prevented from falling off. Moreover, the permeability of the bodily fluid absorbed from the absorbing surface 12 is further improved, and the fluid reaches the superabsorbent polymer 16 smoothly.
In addition, gel blocking of the superabsorbent polymer 16 that has absorbed body fluid is also suppressed. Therefore, the absorbent sheet 10 has a structure completely different from that of the conventional absorbent sheet (FIG. 10) in which a superabsorbent polymer is sandwiched between two absorbent papers (that is, the conventional absorbent sheet). Although the sheet has two plies, the absorbent sheet 10 is a single sheet). Such integration is preferably achieved by lamination using wet papermaking, as described later.

In the absorbent sheet 10 shown in FIG. 8, on the side opposite to the absorbent surface 12, a sized treated absorbent paper or a water-repellent nonwoven fabric, for example, a melt blown material made of polyethylene, polypropylene or the like is used. Is also preferred. Such an absorbent sheet is particularly preferable when a sanitary napkin as in the sixth embodiment (FIG. 6) of the above-described body fluid absorbent article of the present invention is manufactured.

The fiber web 18 is in a wet state before the superabsorbent polymer 16 is sprayed, and it is important that the fibers constituting the fiber web 18 have a very high degree of freedom from each other. . Fiber web 1 in such a state
By spraying the superabsorbent polymer 16 on the upper surface 8, the superabsorbent polymer 16 is three-dimensionally dispersed and fixed in the fiber web 18, that is, from the surface to the inside. Further, the fiber web 18 has such a strength that the superabsorbent polymer 16 does not precipitate on the surface of the absorbent sheet 10 after the fiber web 18 and the fiber aggregate 15 are integrated. It is also important. For this purpose, the fiber web 18 is JIS-P-8
The wet strength measured by 113 is preferably 50 g or more, more preferably 100 g or more.
In order to impart wet strength to the fibrous web 18, as described later, a hot-melt adhesive fiber or a paper strength reinforcing agent is blended. It is also preferable to mix wood pulp or non-wood pulp that forms hydrogen bonds.

[0049] The fiber web 18, the basis weight is preferably from ^{10g / m 2 ~200g / m 2} , and more preferably a ^{10g / m 2 ~100g / m 2} , more preferably 20 g / m ² ~ 80 g / m ² . The grammage is 1
If it is less than 0 g / m ² , when the superabsorbent polymer 16 swells, the superabsorbent polymer 16 will
And may fall out. On the other hand, when the basis weight exceeds 200 g / m ² , the density of the fiber web becomes too high, the absorbent sheet 10 becomes too hard, and the superabsorbent polymer 16 cannot be fixed three-dimensionally, Since the permeability may be deteriorated or the wearing feeling may be further deteriorated, it is preferable to be within the above range.

The fiber web contains at least a hydrophilic fiber. Such hydrophilic fibers can be used without particular limitation as long as the fibers have a hydrophilic surface and can form a fiber web in which the fibers have a very high degree of freedom in a wet state. Examples of such hydrophilic fibers include wood pulp such as softwood kraft pulp and hardwood kraft pulp, natural cellulose fibers such as cotton pulp and straw pulp, regenerated cellulose fibers such as rayon and cupra, polyvinyl alcohol fibers and polyacrylonitrile fibers. And synthetic fibers such as polyethylene fibers, polypropylene fibers, and polyester fibers that have been subjected to a hydrophilic treatment with a surfactant, and the like, but are not limited thereto. One or two or more of these hydrophilic fibers can be used.

The above-mentioned hydrophilic fiber is used for the above-mentioned fiber web 100.
It is preferably contained in an amount of 30 parts by weight or more, more preferably 50 parts by weight or more based on parts by weight.

Among the above hydrophilic fibers, preferred are:
It is a cellulose fiber. Cellulose fibers are preferred because they have a stable hydrophilic surface and remain hydrophilic, especially after wetting. In particular, bulky cellulose fibers such as natural cellulose fibers and regenerated cellulose fibers are preferred. From the viewpoint of cost, it is preferable to use wood pulp, and particularly preferable is softwood kraft pulp. By using such bulky cellulose fibers, not only the dispersibility and the degree of immobilization of the superabsorbent polymer are further improved, but also the drainage of the fibrous web can be more easily controlled during wet papermaking. . Furthermore, since bulky cellulose fiber can form a fibrous web with high bulk and porosity,
The superabsorbent polymer can be easily embedded, dispersed and fixed three-dimensionally in the fiber web, and gel blocking of the superabsorbent polymer can be suppressed. The average fiber length of the bulky cellulose fiber is not particularly limited, but is preferably 1 to 20 mm as a general range. Further, fibers obtained by subjecting synthetic fibers such as PET, PE, and PP to hydrophilic treatment are also preferably used as bulky hydrophilic fibers in the present invention. In the present specification, the term “bulky fiber” means that the fiber shape has a three-dimensional structure such as a twisted structure, a crimp structure, a bent and / or branched structure, or the fiber cross section is extremely thick (for example, when the fiber roughness is 0.3m
g / m or more).

The bulky cellulose fiber is preferably contained in an amount of 30 parts by weight or more, more preferably 50 to 99 parts by weight, based on 100 parts by weight of the fiber web.

Preferred examples of the bulky cellulose fibers include cellulose fibers having a fiber roughness of 0.3 mg / m or more. Cellulose fibers having a fiber roughness of 0.3 mg / m or more are preferable because the cellulose fibers accumulate in a bulky state and a bulky network structure is easily formed in the fiber web. Further, it is preferable because the movement resistance of the body fluid is small and the passage speed of the body fluid increases.

In the present invention, the term “fiber roughness” refers to a fiber having a non-uniform fiber thickness, such as wood pulp.
It is used as a scale representing the thickness of the fiber. For example, a fiber roughness meter (FS-200, KAJANNI ELECTRONIC
S LTD.).

As described above, the bulky cellulose fiber preferably has a fiber roughness of 0.3 mg / m or more, more preferably has a fiber roughness of 0.3 to 2 mg / m, and still more preferably has a fiber roughness of 0.3 to 2 mg / m. The roughness is 0.32 to 1 mg / m.

Examples of cellulose fibers having a fiber roughness of 0.3 mg / m or more include softwood kraft pulp (Federal
"ALBACEL" (trade name) manufactured by Paper Board Co., and PT
"INDORAYON" (trade name) manufactured by Inti Indorayon Utama).

Another preferred example of the bulky cellulose fiber is a cellulose fiber having a fiber cross-section having a roundness of 0.5 to 1, particularly preferably 0.55 to 1. Cellulose fibers having a roundness of the fiber cross section of 0.5 to 1 are preferable because the resistance to movement of bodily fluids is small and the permeation speed of bodily fluids is increased. The method for measuring the roundness of the fiber cross section will be described later.

As described above, it is preferable to use wood pulp as the cellulose fiber. However, in general, the cross section of wood pulp is flat due to delignification treatment, and most of the roundness is less than 0.5. In order to make the roundness of such wood pulp 0.5 or more, for example, the wood pulp may be mercerized to swell the cross section of the wood pulp.

As described above, as the bulky cellulose fiber, mercerized pulp having a roundness of 0.5 to 1 obtained by mercerizing wood pulp is also preferable.
Examples of commercially available mercerized pulp that can be used in the present invention include "FILTRANI" manufactured by ITT Rayonier Inc.
"ER" (product name) and "POROSANIER" (product name) made by the company.

When the fiber roughness is 0.3 mg / m or more,
The use of cellulose fibers having a fiber cross-section having a roundness of 0.5 to 1 is preferable because a bulky network structure is more easily formed and the passage speed of bodily fluids is further increased.

Another preferred example of the bulky cellulose fiber is a crosslinked cellulose fiber obtained by crosslinking intracellular and / or intermolecular cellulose fibers. Such a crosslinked cellulose fiber is preferable because it can maintain a bulky structure even in a wet state.

The method for crosslinking the cellulose fibers is not particularly limited, and examples thereof include a crosslinking method using a crosslinking agent. Examples of such crosslinking agents include N-methylol compounds such as dimethylol ethylene urea and dimethylol dihydroxyethylene urea; polycarboxylic acids such as citric acid, tricarballylic acid and butanetetracarboxylic acid; polyols such as dimethyl hydroxyethylene urea ;
A cross-linking agent for a polyglycidyl ether compound may be used. In particular, a crosslinking agent of a polycarboxylic acid or a polyglycidyl ether compound which does not generate formalin or the like harmful to the human body at the time of crosslinking is preferable.

The amount of the crosslinking agent used is preferably 0.2 to 20 parts by weight based on 100 parts by weight of the cellulose fiber. If the amount used is less than 0.2 parts by weight, the crosslink density of the cellulose fibers is low, so that the elastic modulus may be significantly reduced when wet. The above range is preferable because the cellulose fibers become too rigid and may become brittle when stress is applied.

In order to cross-link the cellulose fibers using the cross-linking agent, for example, an aqueous solution of the cross-linking agent to which a catalyst is added as necessary is impregnated with the cellulose fibers, and the cross-linking agent aqueous solution is designed The cellulose fibers are dehydrated so as to have an adhesion amount, and then heated to a crosslinking temperature,
Alternatively, an aqueous solution of a crosslinking agent is sprayed on the cellulose fiber so as to have a designed adhesion amount by spraying or the like, and then heated to a crosslinking temperature to cause a crosslinking reaction.

[0066] Commercially available crosslinked cellulose fibers include "High Bulk Additiv" manufactured by Weyerhaeuser Paper Co.
e "and the like.

In addition to the bulky cellulose fibers described above, bulky cellulose obtained by crosslinking the inside and / or between the molecules of cellulose fibers such as pulp having a fiber roughness of 0.3 mg / m or more by the above-described method. Fibers are also preferred.

Further, bulky cellulose fibers obtained by cross-linking the inside and / or between the molecules of pulp having a roundness of the fiber cross section of 0.5 to 1 by the above-mentioned method are also preferable.

Further, bulky cellulose fibers obtained by cross-linking the inside and / or between the molecules of the mercerized pulp having a roundness of the fiber cross section of 0.5 to 1 by the above-mentioned method are also preferable.

Further, pulp having a fiber roughness of 0.3 mg / m or more and a roundness of a fiber cross section of 0.5 to 1 (particularly, an average fiber length of 2 to 5 mm) is also preferable.

A more preferable bulky cellulose fiber is obtained by crosslinking pulp having a fiber roughness of 0.3 mg / m or more and a roundness of a fiber cross section of 0.5 to 1 by the above-mentioned method. is there.

A particularly preferred bulky cellulose fiber is obtained by cross-linking pulp having a fiber roughness of 0.3 mg / m or more to a circularity of 0.5 to 1 by mercerization and then the above-mentioned method. is there.

In order to maintain the structure of the absorbent sheet even when it is wet, it is necessary to impart wet strength to the fibrous web. Incorporate a force enhancer.

In order to reinforce the hydrogen bond between the fibers of the cellulose fibers and to improve the strength of the absorbent sheet, instead of the hot-melt adhesive fibers or the paper-strengthening agent, ordinary cellulose fibers, ie, wood pulp are used. It is also effective to mix non-wood pulp and the like. However, in order to sufficiently obtain the strength of the absorbent sheet when wet, it is preferable to mix the absorbent sheet with the hot-melt adhesive fiber or the paper-strength reinforcing agent.

As the above-mentioned heat-meltable adhesive fibers, fibers which are melted by heating and adhere to each other can be used. Specifically, for example, polyolefin fibers such as polyethylene, polypropylene and polyvinyl alcohol, polyester fibers, Polyethylene-polypropylene conjugate fiber, polyethylene-polyester conjugate fiber, low melting point polyester-polyester conjugate fiber, polyvinyl alcohol-polypropylene conjugate fiber whose fiber surface is hydrophilic,
And polyvinyl alcohol-polyester conjugate fibers. When using a conjugate fiber, any of a core-sheath type conjugate fiber and a side-by-side type conjugate fiber can be used. These heat fusible adhesive fibers can be used alone or in combination of two or more. Examples of the heat-meltable adhesive fibers preferably used in the present invention include polyvinyl alcohol fibers soluble in hot water, and core-sheath type polyester fibers.

The heat-fusible adhesive fiber generally has a fiber length of preferably 2 to 60 mm and a fiber diameter of 0.1 to 60 mm.
It is preferably 1 to 3 denier (particularly 0.5 to 3 denier).

As described above, the above-mentioned fiber web has
A polyamine / epichlorohydrin resin, dialdehyde starch, sponge, carboxymethylcellulose, etc. are added as paper strength agents. These paper strength agents are
0.01 to 30 parts by weight, preferably 0.01 to 20 parts by weight, can be added based on 100 parts by weight of the fiber web.

In the case of using the hot-melt adhesive fiber, the fiber web contains 30 to 99 parts by weight of the hydrophilic fiber and 1 to 50 parts by weight of the hot-melt adhesive fiber based on 100 parts by weight of the fiber web. Preferably, More preferably, based on 100 parts by weight of the fiber web, 50 to 97 parts by weight of the hydrophilic fiber and 3 to 3 parts of the hot-melt adhesive fiber are used.
30 parts by weight.

The fiber web is preferably, for example,
It comprises 1 to 10 parts by weight, more preferably 2 to 5 parts by weight of vinylon fiber (polyvinyl alcohol fiber). As the above-mentioned vinylon fiber, it is preferable to use a vinylon fiber that is dissolved by moist heat.

As another example, the fiber web preferably contains 1 to 30 parts by weight, more preferably 5 to 20 parts by weight, of the hot-melt adhesive fiber having a core-sheath structure.
As a specific example of the heat-fusible adhesive fiber having a core-sheath structure, a melting point of polyethylene-vinyl acetate resin having a melting point of 70 ° C to 150 ° C, a polyethylene resin, or a modified polyester resin or a wet-heat-soluble polyvinyl alcohol as a sheath portion, And a synthetic fiber having a core-sheath structure having a polypropylene resin or polyester resin as a core.

On the other hand, when the above-mentioned paper strength reinforcing agent is used, the amount of the hydrophilic fiber is 3% based on 100 parts by weight of the fiber web.
It is preferable that 0 to 100 parts by weight, 0 to 50 parts by weight of other fibers, and 0.01 to 30 parts by weight of the paper strength agent are contained. More preferably, based on 100 parts by weight of the fiber web, 50 to 100 parts by weight of the hydrophilic fiber, 0 to 20 parts by weight of the other fibers, and 0.01 to 20 parts by weight of the paper reinforcing agent.
-20 parts by weight.

For example, based on 100 parts by weight of the fiber web, 30 to 99 parts by weight of the bulky cellulose fiber, 1 to 70 parts by weight of the wood pulp or non-wood pulp, and 0.01 to 30 reinforcing agents
Preferably, it comprises parts by weight. More preferably, based on 100 parts by weight of the fiber web, 50 to 95 parts by weight of the bulky cellulose fiber, 5 to 50 parts by weight of the wood pulp or the non-wood pulp, and 0.05 parts by weight of the paper reinforcing agent.
1 to 20 parts by weight.

Next, the superabsorbent polymer 16 contained in the absorbent sheet 10 will be described. FIG.
As shown in the figure, the superabsorbent polymer 16 is contained in the interior of the absorbent sheet 10 and the absorbent sheet 1
0 are distributed in the space formed between the fibers. More specifically, as shown in FIG. 9, the superabsorbent polymer 16 is mainly provided inside the fiber web 18.
In other words, it included to the inside of the fiber web 18 from the interface between the fiber web 18 and the fiber aggregate 15, that are dispersed in a space formed between the fibers constituting the fibrous web 18. As a result, the superabsorbent polymer 16
Is securely fixed in the absorbent sheet and the occurrence of gel blocking is suppressed. Here, "the superabsorbent polymer is contained inside the absorbent sheet" means,
It does not mean that the superabsorbent polymer does not exist on the surface of the absorbent sheet at all, but in a preferred method for producing the absorbent sheet described below, a trace amount of the superabsorbent sheet inevitably exists on the surface of the absorbent sheet. The superabsorbent polymer is acceptable and means that most of the superabsorbent polymer exists inside the absorbent sheet.

[0084] In addition, the superabsorbent polymer 16 is bonded to the hydrophilic fibers constituting the upper Symbol fiber web 18.
Therefore, the fixation of the superabsorbent polymer 16 is further strengthened, and the gel blocking is further suppressed. Here, the superabsorbent polymer 16 is mainly bonded to hydrophilic fibers, but there is no problem if it is bonded to other fibers constituting the absorbent sheet, for example, hot melt fibers. Also, not all of the particles need be adhered to the fiber. It is preferable that 50% by weight or more of the superabsorbent polymer 16 is adhered to the fiber based on the total amount thereof.
It is preferable that 0% by weight or more is bonded to the fiber. The method for bonding the superabsorbent polymer 16 to the fibers will be described later.

When a highly agglomerated polymer of the particle agglomerated type is used as the above-mentioned superabsorbent polymer, in which a spherical polymer is used as primary particles and agglomerated to form secondary particles, all of the primary particles are made of fiber. The superabsorbent polymer may be fixed to the fiber if a part of the secondary particles adhere to the fiber.

Preferably, the superabsorbent polymer 16
Are not dispersed in a layered manner in the absorbent sheet 10, but are dispersed three-dimensionally as shown in FIG. Therefore, the superabsorbent polymer can be dispersed in a large amount. That is, the upper limit of the spraying basis weight of the superabsorbent polymer in the conventional absorbent sheet in which the superabsorbent polymer 16 is dispersed in a layer form (that is, two-dimensional) is generally about 50 to 50.
100 g / m ² , whereas the absorbent sheet 1
0, the superabsorbent polymer 16 can be dispersed three-dimensionally.
The upper limit of the spread basis weight of about 200-30Og / m ² and it is possible to, scatter basis weight of the high absorbent polymer 16 can be increased to about 3 times the conventional absorbent sheet. Therefore, the absorbent sheet 10 dramatically increases the amount of body fluid absorbed as compared to the conventional absorbent sheet. Furthermore, since the superabsorbent polymer 16 is three-dimensionally dispersed,
The original absorption performance of the superabsorbent polymer 16 is more effectively expressed. That is, even when the same amount of the high-absorbent polymer as that of the conventional absorbent sheet is used, the absorption performance can be further improved and the absorbent sheet can be made extremely thin. In addition, since the basis weight of the spray can be increased, it can be suitably used as an absorption layer of a disposable diaper or the like requiring a large absorption capacity.

The superabsorbent polymer has a spray basis weight of 5 to 300 g / m ² , preferably 10 to 250 g / m ² . Also, when used in applications where the amount of body fluid absorption is not large, in order to make the absorbent sheet extremely thin,
It is preferably ²⁰ to 70 g / m ² . If the applied grammage is less than 5 g / m ² , the water absorption capacity is insufficient, and a sufficient function cannot be exhibited. On the other hand, if the spraying basis weight is more than 300 g / m ² , the adhesive strength between the fiber web and the fiber aggregate decreases, and the superabsorbent polymer easily falls off.

As the high-absorbency polymer 16, a polymer capable of absorbing and retaining a body fluid 20 times or more its own weight and capable of gelling is preferable. The shape is not particularly limited, and may be spherical, massive, grape-like, powdery, or fibrous, and preferably has a size of 1
It is in the form of particles of up to 1000 μm (more preferably 10 to 500 μm). Examples of such superabsorbent polymers include starch, crosslinked carboxymethylated cellulose, polymers or copolymers of acrylic acid or alkali metal acrylates, such as polyacrylic acid and its salts, and polyacrylate graft polymers. Coalescence can be mentioned.
As the polyacrylate, a sodium salt can be preferably used. Moreover, maleic acid, itaconic acid, acrylamide, 2-acrylamide-2-
Copolymers obtained by copolymerizing comonomers such as methylpropanesulfonic acid, 2- (meth) acryloylethanesulfonic acid, 2-hydroxyethyl (meth) acrylate or styrenesulfonic acid within a range that does not reduce the performance of the superabsorbent polymer are also provided. It can be used preferably.

Next, the fiber aggregate 15 having the absorbent surface 12 in the absorbent sheet 10 will be described. Here, the "absorbing surface" refers to a surface that first absorbs a bodily fluid when the absorbent sheet 10 absorbs a bodily fluid. That is, In its Contact <br/> above absorbent sheet 10, to absorb body fluid from the upper Symbol fiber assembly 15 side.

The fiber aggregate does not contain the superabsorbent polymer on the absorption surface side (the superabsorbent polymer does not exist). Here, "does not contain a superabsorbent polymer" does not mean that the fiber aggregate does not contain the superabsorbent polymer on its absorption surface side, and is preferable for the absorbent sheet described later. A trace amount of superabsorbent polymer which is inevitably mixed in the production method means that, although it is acceptable, the superabsorbent polymer is not substantially contained on the absorption surface side.

The fiber aggregate is obtained by mechanical entanglement or physical entanglement of fibers, thermal bonding, and the like. For example, paper and nonwoven fabric can be used.
As the paper, paper obtained by wet papermaking or creped paper can be used. On the other hand, as the nonwoven fabric, various nonwoven fabrics such as a carded nonwoven fabric, a spunbonded nonwoven fabric, and a spunlace nonwoven fabric mainly composed of synthetic cellulose fibers such as rayon and cupra and natural cellulose fibers such as cotton can be used.

[0092] The fiber assembly preferably contains hydrophilic fibers. As such hydrophilic fibers, those similar to those used in the above fiber web can be used. The hydrophilic fiber is preferably contained in an amount of 30 parts by weight or more, more preferably 50 to 99 parts by weight, based on 100 parts by weight of the fiber assembly.

It is preferable that the fiber aggregate has wet strength similarly to the fiber web. By providing wet strength, even when the absorbent sheet is wet, its form can be stably maintained.
The wet strength of the fiber aggregate is preferably 50 g or more, more preferably 100 g or more, as measured according to JIS-P-8113. In order to impart wet strength to the fiber aggregate, the above-described hot-melt adhesive fiber or paper strength agent is blended in the same manner as in the case of the fiber web. It is also preferable to mix wood pulp or non-wood pulp that forms hydrogen bonds. In this case, the heat-meltable adhesive fiber is preferably contained in an amount of 1 to 50 parts by weight, more preferably 3 to 30 parts by weight, based on 100 parts by weight of the fiber assembly. Further, the paper strength reinforcing agent is preferably contained in an amount of 0.01 to 30 parts by weight, more preferably 0.02 to 20 parts by weight, based on 100 parts by weight of the fiber aggregate.

The fiber aggregate is particularly preferably formed by the same composition as the fibers and components forming the fiber web.

The above-mentioned fiber aggregate is preferably made of a non-woven fabric, particularly preferably a dry-process non-woven fabric, for example, a card-process non-woven fabric. In particular, in the body fluid absorbent article of the embodiment shown in FIGS. 5 and 6, since the absorbent sheet also serves as a body fluid permeable surface layer, by using a nonwoven fabric of synthetic fibers as the fiber aggregate, ,
A bodily fluid-absorbing article with a further improved salat feeling can be obtained.

The fiber aggregate has a basis weight of 10 to 20.
0 g / m ² , preferably 10 to 100 g / m ²
More preferably, it is ² . The above grammage is 10 g / m ²
Otherwise, the superabsorbent polymer may protrude from the fiber aggregate and fall off when the superabsorbent polymer swells. On the other hand, when the grammage exceeds 200 g / m ² , the density of the fiber aggregate is too high, and the absorbent sheet may be too hard.

The fiber aggregate may be manufactured before manufacturing the fiber web, or may be manufactured simultaneously with the fiber web when manufacturing the absorbent sheet.

In the absorbent sheet, the basis weight of the fiber aggregate is 10 to 200 g / m ² , the basis weight of the high absorbent polymer is 5 to 300 g / m ² , and the fiber web is The basis weight is preferably 10 to 200 g / m ² , and the basis weight of the fiber assembly is 10 to 100 g / m ^2.
m ² and the spray basis weight of the superabsorbent polymer is 5 to 2
00 g / m ² and the basis weight of the fiber web is 10 to 1
More preferably, it is 00 g / m ² .

The total basis weight of the absorbent sheet is preferably from 21 to 500 g / m ² ,
And more preferably from 300 to 300 g / m ² , more preferably from 50 to ² g / m ^2.
More preferably, it is 00 g / m ² .

The absorbent sheet preferably has a fiber density of 0.1 g / cm ³ or more.
More preferably from ~0.4g / cm ^3, 0.1
More preferably, it is で 0.2 g / cm ³ . By setting the fiber density in such a range, gel blocking of the superabsorbent polymer is more effectively prevented. A fiber density in such a range can be easily realized by using bulky hydrophilic fibers (particularly bulky cellulose fibers).

A particularly preferred embodiment of the above-mentioned absorbent sheet is formed of a bulky hydrophilic fiber and a hot-melt adhesive fiber or a paper reinforcing agent, and comprises a fiber web and a fiber assembly.
It is a sheet-like material of fiber that is composed integrally with
It is composed of a certain fiber structure and superabsorbent polymer particles, and the superabsorbent polymer particles are not present on the absorbent surface where the absorbent sheet absorbs bodily fluids, but are dispersed and fixed in the fiber structure. The thickness of the absorbent sheet is 0.
An absorbent sheet having a thickness of 3 to 1.5 mm and a spray basis weight of the superabsorbent polymer of 20 to 70 g / m ² . Such an absorbent sheet has an extremely small thickness. In addition, as long as a large amount of body fluid is not absorbed, there is almost no increase in thickness after absorption of body fluid. Therefore, when such an absorbent sheet is used for an absorbent layer of a sanitary napkin, for example,
Even after the absorption of menstrual blood, a comfortable fit can be obtained.

When the absorbent sheet is used as an absorbent layer of a sanitary napkin, the basis weight of the highly absorbent polymer in the absorbent sheet is preferably 10 to 100 g / g.
m ² , more preferably 20 to 70 g / m ² , the basis weight of the fiber aggregate is preferably 10 to 80 g / m ² , more preferably 15 to 50 g / m ² , and the basis weight of the fiber web is preferred. Is 10 to 80 g / m ² , more preferably 15
５０50 g / m ² , and the thickness of the absorbent sheet is preferably 0.3-1.5 mm. On the other hand, when the absorbent sheet is used as an absorbent layer for holding a multi-liquid such as a disposable diaper, the spray basis weight of the superabsorbent polymer in the absorbent sheet is preferably 50 to 300 g / m ² , and more preferably. 100 to 250 g / m ² , the basis weight of the fiber aggregate is preferably 20 to 200 g / m ² , more preferably 20 to 100 g / m ² , and the basis weight of the fiber web is preferably 20 to 200 g / m 2. ² , more preferably 20 to 1
00 g / m ² , and the thickness of the absorbent sheet is preferably 0.5 to 1.5 mm.

The thickness of the above-mentioned absorbent sheet can be reduced because the high-absorbent polymer is dispersed and adhered to the fibers, so that the absorption efficiency is good. Especially when using bulky cellulose fibers,
It is preferable because the dispersion state of the superabsorbent polymer is further improved. That is, the absorbent sheet has a thickness of 0.3 to 1.5 mm under a load of 2.5 g / cm ² ,
It is preferably 1.2 mm. Thus, the absorbent sheet is extremely thin. Moreover, the increase in thickness is small even after absorption of body fluid. The reason for this is that when a body fluid is absorbed, the superabsorbent polymer becomes larger and the inter-fiber distance is expanded,
As a result, only the thickness of the absorbent sheet is increased, and US Pat. No. 4,605,402 and US Pat.
This is because there is no increase in the thickness due to the elasticity of the fibers and the release of the fibers of the superabsorbent polymer as in No. 1,050.

The thickness of the absorbent sheet is the thickness after the fiber aggregate 15 and the fiber web 18 are integrated, and this thickness is smaller than before the integration. Such integration is largely attributable to the hot-melt adhesive fiber or the paper strength reinforcing agent blended in the absorbent sheet. Further, in the above-mentioned absorbent sheet, as described above, since the superabsorbent polymer is dispersed and adhered to the fibers, the absorption efficiency is good, and thus the absorbent sheet can be made thin. In particular, it is preferable to use bulky cellulose fibers because the dispersion state of the superabsorbent polymer is further improved. Since the superabsorbent polymer is in intimate contact with the fibers and the fibrous aggregate 15 and the fibrous web 18, the transmission of the body fluid to the superabsorbent polymer becomes smooth. Further, since the fiber aggregate 15 and the fiber web 18 are joined by the heat-meltable adhesive fiber or the paper-strength reinforcing agent, the structure is kept stable even when wet, and the liquid is transferred to the highly absorbent polymer. Excellent in fixability and fixability of superabsorbent polymer. The thickness of the absorbent sheet is, as described above, U.S. Pat.
Unlike U.S. Pat.
In particular, when bulky cellulose fibers are used as hydrophilic fibers, the density becomes low and a space is formed by the fibers, so that the superabsorbent polymer is excellent in dispersibility and liquid transferability, and particularly suitable for absorbing high viscosity body fluids. Excellent. In addition, since the space by the fibers is ensured, the liquid absorbing property after wetting is excellent without greatly increasing the thickness. As described above, in the absorbent sheet, the fixability and the absorption efficiency of the superabsorbent polymer were improved, so that the absorbent sheet could be made thinner. In addition, the integration and sheeting of the fiber aggregate 15 and the fiber web 18 and the use of a heat-meltable adhesive fiber or a paper-strengthening agent that contributes to stabilization of the structure when wet are one of the factors for thinning. One.

Next, a preferred method for producing the above absorbent sheet will be described with reference to the drawings. Here, FIG. 11 is a schematic view showing an apparatus preferably used for producing the absorbent sheet. This method is a method for producing an absorbent sheet containing at least a hydrophilic fiber and a hot-melt adhesive fiber or a paper-strengthening agent, and a superabsorbent polymer. Aggregate containing a hydrophilic fiber and a hot-melt adhesive fiber or a paper-strengthening agent on which a superabsorbent polymer is sprayed on a wet fibrous web formed by wet papermaking of a water slurry containing an agent. And drying and integrating them. According to this method, the superabsorbent polymer does not exist on the absorbent surface where the absorbent sheet absorbs bodily fluids,
In addition, it can be easily dispersed and arranged inside the absorbent sheet. In addition, a highly absorbent polymer can be easily adhered and fixed to the hydrophilic fibers constituting the absorbent sheet. Further, it becomes easy to make the thickness of the absorbent sheet as extremely thin as 0.3 to 1.5 mm.

The above method will be described in detail. First, the fiber web containing the hydrophilic fiber is formed. The method for forming the fiber web is not particularly limited, and for example, a dry papermaking method or the like can be used, but preferably, a wet papermaking method is used. This is because, as described later, when the superabsorbent polymer is sprayed on the fiber web, the fiber web must be in a wet state and the degree of freedom of the fiber is extremely high. When the web is formed, the wet state is immediately realized, so that it is not necessary to perform the wet state in a separate step. Further, since the fibers of the fiber web obtained by the wet papermaking method are not sufficiently bonded to each other before drying, when the superabsorbent polymer is sprayed in this state, the superabsorbent polymer is interwoven between the fibers. There is also an advantage that it can be easily buried three-dimensionally in the space formed in the space, and a large amount of superabsorbent polymer can be sprayed.

When the fiber web is subjected to wet papermaking,
The fibers and components forming the fiber web, preferably, the hydrophilic fibers, and the hot-melt adhesive fibers or the paper-strengthening agent are dispersed in water to a predetermined concentration to form a slurry. . The concentration of the hydrophilic fiber, the hot-melt adhesive fiber or the paper strength agent in the slurry may be the concentration in general wet papermaking. Further, the relative blending ratio between the hydrophilic fiber, the hot-melt adhesive fiber or the paper strength reinforcing agent, etc., is such that the blending ratio in the fiber web obtained by wet papermaking is in the above-described range. What should I do?

In the wet state, the superabsorbent polymer is sprayed on the fiber web thus obtained. The wet state of the fiber web is preferably such that the fiber web contains 20 to 500 parts by weight of water based on 100 parts by weight of the dry fiber web, and more preferably contains 50 to 300 parts by weight of water.
If the amount of water is less than 20 parts by weight, the sprayed superabsorbent polymer absorbs water and becomes wet, so that the tackiness cannot be obtained. If the amount exceeds 500 parts by weight, the superabsorbent polymer will have excessive water absorption, which may result in poor drying in the drying step described below.

The superabsorbent polymer is sprayed on the wet fiber web. As a result, the superabsorbent polymer absorbs water, becomes tacky, is buried in the fibers constituting the fiber web, and is adhered and fixed to the fibers by subsequent drying. Further, the fiber web in a wet state has a degree of freedom since the fibers constituting the fiber web are not yet bonded to each other, so that the superabsorbent polymer can be three-dimensionally dispersed. Therefore, a larger amount of the highly absorbent polymer can be stably fixed as compared with the conventional absorbent sheet. When the superabsorbent polymer is sprayed, the superabsorbent polymer may be evenly spread over the entire surface of the wet fiber web, or may be spaced along the longitudinal direction of the wet fiber web as necessary. The fiber web may be partially dispersed in a streak shape or intermittently sprayed in a shot shape in the longitudinal direction of the wet fiber web.

Next, the fiber aggregate is superimposed on the surface of the fiber web on which the superabsorbent polymer has been sprayed. At this time, since the fibers in the fiber web still have a degree of freedom, the superabsorbent polymer is further buried in the fiber web, and the fibers in the fiber web and the fiber aggregate It easily entangles with the fibers inside.

Subsequently, by drying the superimposed body of the fiber web and the fiber assembly, the fibers are entangled with each other, and furthermore, the effect of hydrogen bonding and heat fusion is added. The high-absorbent polymer adhering to the fibers is dried and fixed together with the aggregate and the absorbent sheet is obtained. The drying temperature is preferably in the range of 100 to 180 ° C., although it depends on the type of fiber or the like to be used.
~ 150 ° C. By drying and unifying, the fiber web and the fiber aggregate are integrated, and the fibers constituting the fiber web are combined with each other to form a sheet. The drying means is not particularly limited, and for example, a Yankee dryer or an air-through dryer can be used.

Particularly preferably, the absorbent sheet is produced in a single in-line process using a wet paper machine. That is, as shown in FIG. 11, the fibrous web 18 is formed in the forming part 40 of the wet paper machine, and the fibrous web 18 is dewatered in the suction dewatering step 42. The superabsorbent polymer 16 is sprayed on the fiber web 18 immediately before the press part 44, and the fiber assembly 15 is superimposed thereon. Then, these are dried and integrated by a dryer 46. By such a method,
The absorbent sheet 10 can be manufactured at high speed and easily.

As the wet paper machine, an ordinary paper machine can be used. Examples of such a paper machine include a fourdrinier paper machine and a round net paper machine. In addition, about the process other than the above, the process in a normal papermaking method can be used suitably.

Although the method for producing the absorbent sheet has been described based on the preferred embodiment, it goes without saying that the method for producing the absorbent sheet is not limited to such a method.

In the absorbent sheet, the superabsorbent polymer is less likely to fall off, and the sheet can be prevented from being torn due to swelling of the superabsorbent polymer. Therefore, the above-mentioned absorbent sheet can be used alone as a bodily fluid absorbent article. The absorbent sheet may be mixed with a deodorant, a bactericide, or the like at the time of production to enhance other functions of the body fluid absorbent article of the present invention.

[0116]

EXAMPLES The present invention will be described in more detail with reference to the following Examples and Comparative Examples, but it goes without saying that the present invention is not limited to these Examples. In the following description, “parts” means “parts by weight” unless otherwise specified.

[Production Example 1] Production of absorbent sheet Fiber roughness 0.18 mg / m, roundness of fiber cross section 0.3
2 chemical pulp [softwood kraft pulp, Skeena Cellu
SKEENA PRIME (trade name, manufactured by lose Co.) is dispersed and mixed in water, and a paper reinforcing agent [polyamide epichlorohydrin resin, trade name; Caimen WS-570, company name; Nippon PMC Co., Ltd.] was dispersed and mixed with one part of a resin component in water.
^A fiber web was formed to be ² . Next, the fiber web is dried by a suction box into a dry fiber web 1.
The fiber web was dewatered until the water content became 200 parts based on 00 parts. Then, immediately before the press part, the superabsorbent polymer [Kao Corporation] was placed on the wet fiber web after dehydration.
Polymer Q (trade name)] was sprayed almost uniformly at a spray basis weight of 50 g / m ² .

On the surface of the fiber web on which the superabsorbent polymer was sprayed, as a fiber aggregate, a previously made absorbent paper (basis weight 40 g / m 2) having the same composition as the fiber web was prepared. ² ) is superimposed, and the superimposed body of the fiber web and the absorbent paper is introduced into a dryer, and
By drying and integrating at a temperature of 30 ° C., one absorbent sheet having a highly absorbent polymer fixed therein was obtained. This absorbent sheet is referred to as absorbent sheet A.

The fiber roughness and the roundness of the fiber cross section of the chemical pulp used in the fiber web and the absorbent paper were measured as follows.

<Measurement of Fiber Roughness> Fiber roughness meter FS-20
0 (manufactured by KAJAANI ELECTRONICS LTD.).
First, in order to determine the true weight of the chemical pulp, the chemical pulp is dried in a vacuum dryer at 100 ° C. for 1 hour to remove water present in the chemical pulp.
About 1g of the above chemical pulp quickly with ± 0.1mg accuracy
Measure accurately. Next, the chemical pulp was completely disintegrated in 150 ml of water using a mixer attached to the fiber roughness meter so as not to damage the chemical pulp, and this was 5,000 ml.
Was diluted with water until the solution reached, 50 ml was accurately weighed from the obtained diluent, and this was used as a fiber roughness measurement solution. The fiber roughness was determined according to the operation procedure of the fiber roughness meter.

<Measurement of Roundness of Fiber Cross Section> The cross section of the chemical pulp was sliced perpendicularly to the cross section direction so that the area did not change, a cross section photograph was taken with an electron microscope, and the cross section photograph was taken by an image diffraction apparatus. [Avio E manufactured by Nippon Avionics Co., Ltd.
XCEL ”(trade name)], and the roundness of the fiber cross section of the chemical pulp was determined using the following equation. The roundness was determined by measuring 100 points of the fiber cross section of the above-mentioned chemical pulp and taking the average value.

[0122]

(Equation 1)

[Production Example 2] Production of absorbent sheet Fiber roughness 0.36 mg / m, roundness of fiber cross section 0.80
Mercerized pulp [POROSA manufactured by ITT RAYONIER INC.
NIER-J ”(trade name)], 95 parts, polyvinyl alcohol fiber of 1 denier thickness and 3 mm length [Hot-melt adhesive fiber, Fibribond (trade name) manufactured by Sansho Co., Ltd .; 5] was dispersed and mixed in water to a predetermined concentration, and the dispersion mixture was formed into a fiber web in a forming part of a wet paper machine so that the dry basis weight was 40 g / m ² . Next, the fiber web was dehydrated with a suction box until the moisture content became 150 parts based on 100 parts of the dry fiber web. Then, immediately before the press part, a superabsorbent polymer [Polymer Q (trade name) of Kao Corporation] was sprayed on the wet fiber web after dehydration almost uniformly at a spraying basis weight of 50 g / m ² .

On the surface of the fiber web on which the superabsorbent polymer was sprayed, as a fiber aggregate, a previously made absorbent paper (basis weight 40 g / m 2) having the same composition as the fiber web was prepared. ² ) is superimposed, and the superimposed body of the fiber web and the absorbent paper is introduced into a dryer, and
By drying and integrating at a temperature of 30 ° C., one absorbent sheet having a highly absorbent polymer fixed therein was obtained. This absorbent sheet is referred to as absorbent sheet B.

[Production Example 3]Manufacture of absorbent sheets Fiber roughness 0.32mg / m, roundness of fiber cross section 0.30
Cross-linked pulp from Weyerhauser Paper “High Bul
k Additive HBA-S ”(trade name)] and 70 parts
Softwood with a fiber roughness of 0.18 and a roundness of fiber cross section of 0.32
Kraft pulp (“SKEENA P” manufactured by Skeena Cellulose Co.
RIME "(trade name)] 30 parts dispersed and mixed in water
Strengthened paper strength for 100 parts of dry weight of mixed pulp
Agent [polyamide epichlorohydrin resin, trade name;
Men WS-570, company name; Nippon PMC Co., Ltd.]
After dispersing and mixing 1 part of the components in water to obtain a predetermined concentration,
The dispersion mixture is dried in the forming part of a wet paper machine.
Dry basis weight is 40g / m^TwoTo form a fiber web
Was. Next, the fiber web is placed in a suction box.
To 100 parts moisture based on 100 parts dry fiber web
The fiber web was dewatered until it was. Then press
Immediately before, high absorbency on the wet fiber web after dehydration
Spray polymer [Polymer Q (trade name) of Kao Corporation]
Basis weight 50g / m ^TwoWas sprayed almost uniformly.

On the surface of the fiber web on which the superabsorbent polymer was sprayed, as a fiber aggregate, a previously made absorbent paper (basis weight 40 g / m 2) having the same composition as the fiber web was prepared. ² ) is superimposed, and the superimposed body of the fiber web and the absorbent paper is introduced into a dryer, and
By drying and integrating at a temperature of 30 ° C., one absorbent sheet having a highly absorbent polymer fixed therein was obtained. This absorbent sheet is referred to as absorbent sheet C.

[Production Example 4] Production of absorbent sheet Fiber roughness 0.32 mg / m, roundness of fiber section 0.30
Cross-linked pulp from Weyerhauser Paper “High Bul
k Additive HBA-S "(trade name)] and 95 parts of the above-mentioned PVA fiber were dispersed and mixed in water to a predetermined concentration, and then the dispersion mixture was dried in a forming part of a wet paper machine to have a dry basis weight of 40 g. / M ² to form a fiber web. Next, the fiber web was dehydrated with a suction box until the water content became 100 parts based on 100 parts of the dry fiber web. Then, immediately before the press part, a superabsorbent polymer [Polymer Q (trade name) of Kao Corporation] was sprayed on the wet fiber web after dehydration almost uniformly at a spraying basis weight of 50 g / m ² .

On the surface of the fiber web on which the superabsorbent polymer was sprayed, as a fiber aggregate, a previously made absorbent paper (basis weight 40 g / m 2) having the same composition as the fiber web was prepared. ² ) is superimposed, and the superimposed body of the fiber web and the absorbent paper is introduced into a dryer, and
By drying and integrating at a temperature of 30 ° C., one absorbent sheet having a highly absorbent polymer fixed therein was obtained. This absorbent sheet is referred to as absorbent sheet D.

[Production Example 5]Manufacture of absorbent sheets Fiber roughness 0.32mg / m, roundness of fiber cross section 0.30
Cross-linked pulp from Weyerhauser Paper “High Bul
k Additive HBA-S "(trade name)] 90 parts
1.1 denier, 5mm long low melting point polyester adhesive
Fiber [TM-07N (trade name) manufactured by Teijin Limited]
Part is dispersed and mixed in water to a predetermined concentration.
The dry liquid weight is 4 in the forming part of the wet paper machine.
0 g / m ^TwoThus, a fiber web was formed. Next
Then, the fiber web is dried with a suction box.
Until the water content becomes 100 parts based on 100 parts of the web,
The fiber web was dewatered. Then, just before the press part,
The superabsorbent polymer is placed on the wet fiber web after dehydration.
[Polymer Q (trade name) of Kao Corporation] is sprayed.
g / m^TwoWas sprayed almost uniformly.

Of the above-mentioned fiber web, a polyethylene / polypropylene composite fiber having a thickness of 2.2 denier and a length of 38 mm [manufactured by Chisso Co., Ltd.] obtained by applying a hydrophilic treatment to the surface on which the superabsorbent polymer was sprayed. ], Using a dry heat-bonded nonwoven fabric (basis weight 40 g / m ² ) manufactured by a card machine.
The fiber web and the non-woven fabric are introduced into a dryer, and dried at a temperature of 130 ° C.
By integrating, a single absorbent sheet having a highly absorbent polymer fixed therein was obtained. This absorbent sheet is referred to as absorbent sheet E.

Comparative Production Example 1 Production of Absorbent Sheet Chemical pulp used in Production Example 1 having a fiber roughness of 0.18 mg / m and a roundness of fiber cross section of 0.32 [Skeena Cellulose Co., Ltd.]
SKEENA PRIME (trade name) manufactured by Kabushiki Kaisha, Ltd.] was used to make an absorbent sheet using an absorbent paper made in advance at a basis weight of 40 g / m ² . That is, water is sprayed on the absorbent paper until 200 parts based on 100 parts of the absorbent paper (dry). Subsequently, a highly absorbent polymer [Polymer Q (trade name) of Kao Corporation] was sprayed on the wet absorbent paper at a spray basis weight of 50 g / m ² almost uniformly.

In the absorbent paper, an absorbent paper having the same composition as that of the absorbent paper and having a basis weight of 40 g / m ² was superimposed on the surface on which the superabsorbent polymer was sprayed. After the laminated body was pressure-bonded and integrated, it was dried with a dryer to obtain an absorbent sheet having a total basis weight of 130 g / m ² . In this absorbent sheet, the absorbent paper on which the superabsorbent polymer is sprayed is not a wet fiber web, but pulp fibers strongly bound to each other. The absorbent polymer is sandwiched in layers. This absorbent sheet is referred to as absorbent sheet F.

Comparative Production Example 2 Production of Absorbent Sheet Absorbent paper (dry) was placed on the same absorbent paper as Comparative Production Example 1.
Spray water until 10 parts based on 100 parts. Then, a superabsorbent polymer [Polymer Q (trade name) of Kao Corporation] was sprayed on the wet absorbent paper, and the basis weight was 50 g / m2.
Spread almost uniformly with ² .

In the absorbent paper, a 40 g / m ² basis weight absorbent paper having the same composition as that of the absorbent paper was superimposed on the surface on which the superabsorbent polymer was sprayed. The superimposed body is embossed and crimped through a grid embossing roll divided in 5 mm sections in the vertical and horizontal directions.
After being integrated, it is dried with a drier and the total basis weight is 13
An absorbent sheet of 0 g / m ² was obtained. In this absorbent sheet, the absorbent paper on which the superabsorbent polymer is sprayed is not a wet fiber web, but pulp fibers strongly bound to each other. The absorbent polymer is pressed by embossing. This absorbent sheet is referred to as absorbent sheet G.

Comparative Production Example 3 Production of Absorbent Sheet On an absorbent paper similar to Comparative Production Example 1, an adhesive [Movinyl 710 (trade name) of Hoechst Gosei Co., Ltd.] was applied with a basis weight of 20.
g / m ² , and then a superabsorbent polymer [Polymer Q (trade name) of Kao Corporation] is sprayed thereon.
g / m ² was sprayed almost uniformly.

In the absorbent paper, an absorbent paper having the same composition as the absorbent paper and having a basis weight of 40 g / m ² is superimposed on the surface on which the superabsorbent polymer has been sprayed. After the laminated body was pressure-bonded and integrated, it was dried with a dryer to obtain an absorbent sheet having a total basis weight of 150 g / m ² . In this absorbent sheet, the absorbent paper on which the superabsorbent polymer is sprayed is not a wet fiber web, but pulp fibers strongly bound to each other. The absorbent polymer is fixed in a layer by an adhesive. This absorbent sheet is referred to as absorbent sheet H.

Comparative Production Example 4 Production of Absorbent Sheet A dry absorbent sheet containing a synthetic pulp and a superabsorbent polymer was produced. That is, polyethylene synthetic pulp 25
Pulp sheet (softwood pulp, manufactured by Hercules Co., Ltd.) comprising 75 parts by weight and a chemical pulp is fibrillated with a hammer mill to form a highly absorbent polymer having a basis weight of 80 g / m ^2. [Aqualic CAW-4 (trade name) manufactured by Nippon Shokubai Co., Ltd.] was mixed into the raw materials so as to be 50 g / m ² , and then the polyethylene synthetic pulp was fused and integrated by hot air treatment. . This dry-type absorbent sheet has a superabsorbent polymer also on its surface. This absorbent sheet is referred to as absorbent sheet I.

[Comparative Production Example 5] Production of Absorbent Sheet A pulp sheet having a basis weight of 45 g / m ² (softwood pulp, manufactured by Hapix Corporation) formed by an air laid method was placed between a super absorbent polymer [Nippon Shokubai] AQUALIC CAW-4 (trade name) manufactured by Co., Ltd.] was sprayed so as to have a basis weight of 50 g / m ² , and then an absorbent sheet in which pulp was fixed with a chemical binder was produced. This absorbent sheet is referred to as absorbent sheet J.

Absorbent sheets A to E in Production Examples 1 to 5
Tables 1 and 2 show the composition and production method of the absorbent sheets F to J in Comparative Production Examples 1 to 5, respectively.

[0140]

[Table 1]

[0141]

[Table 2]

Various tests were performed on the absorbent sheets A to J by the methods described below. Table 3 shows the results.

<Thickness> A load of 2.5 g / cm ² was applied to the upper surface of the absorbent sheet cut to an appropriate size with a load area of 10 cm ² (a disc having a radius of 17.8 mm), and the thickness was measured with a thickness gauge. It was measured. The average value of a total of 10 points was taken as the thickness.

<Drop test of superabsorbent polymer> 70 × 2
After measuring the weight of the absorbent sheet cut to 00 mm,
This is put in a plastic bag with a length of 280 mm and a width of 200 mm with a chuck. In this state, vibration is applied while shaking 50 times by hand. After completion of the test, the change in weight of the absorbent sheet was measured, and the colored water stained with blue No. 1 (0.3%) was used so that the superabsorbent polymer dropped into the plastic bag could be easily observed with the naked eye.
g / 100 ml of water) in a plastic bag to swell the superabsorbent polymer and visually determine the degree of shedding. O: Almost no dropout of the superabsorbent polymer was observed. Δ: Some loss of the superabsorbent polymer was observed. ×: Dropping of the superabsorbent polymer is considerably observed. The measurement was performed ten times, and the average value was defined as the amount of dropout.

<Sheet Strength of Absorbent Sheet when Wet> 2
Hold the absorbent sheet cut to 00 mm x 200 mm in hand, and place on the desk the colored water (0.3 g / water
(00 ml) was dropped, and the colored water was wiped off with an absorbent sheet held in hand. A total of three wiping tests were carried out (to be absorbed by a total of 30 g of the absorbent sheet), and a tear test of the sheet on the surface of the absorbent sheet and a drop-off test of the superabsorbent polymer were performed.・ ・ ・: The surface of the absorbent sheet was not broken, and the superabsorbent polymer did not fall off. Δ: The surface of the absorbent sheet was slightly torn, but the superabsorbent polymer did not fall off. X: The surface of the absorbent sheet was torn and the high-absorbent polymer was also dropped.

<Saturated Absorption Amount> A 5-cm square absorbent sheet was placed in a bag made of nonwoven fabric, and the bag was immersed in ion-exchanged water for 10 minutes. After the bag is taken out of the ion-exchanged water, it is hung in the air for one hour, the attached water is dropped, the weight is measured, and the weight increase per gram of the absorbent sheet is determined as the saturated absorption amount (g / g). ).

<Absorption speed> As shown in FIG.
In the center of the corner absorbent sheet 10, a 10 cm square transparent acrylic plate 20 having a hole with a diameter of 1 cm and a weight 22 are placed,
With a load of 5 g / cm ² applied to the absorbent sheet 10,
20 ml of physiological saline was injected through the hole, and the time required for absorbing physiological saline was defined as the absorption rate. The measurement of the absorption rate was performed twice, but the second injection (reabsorption rate) was performed one minute after the first measurement.

<Measurement of liquid return> After measuring the absorption rate,
As shown in FIG. 13, 1
Ten pieces of 5 cm square filter paper 24 (Toyo filter paper TYPE 2) are stacked, and a 15 cm square acrylic plate 26 and weight 22 are further placed on top of it.
Apply for 1 minute to a load of 0 g / cm ² , then filter paper 2
4 was taken out, and the weight of the physiological saline absorbed by the filter paper 24 was taken as the liquid return amount.

[0149]

[Table 3]

Example 1 A sanitary napkin having the structure shown in FIG. 1 was manufactured. That is, as the absorbent sheet 10, an absorbent sheet A having a length of 175 mm and a width of 73 mm, and a fluff pulp having a length of 175 mm and a width of 73 mm adjusted to a thickness of 4.5 mm with a basis weight of 300 g / m ² on its absorbent surface. 2a was laminated. The side part and the top part of the combined body of the absorbent sheet A and the fluff pulp were adjusted to have a basis weight of 18 g / m ² and a width of 130 m.
m, 175mm long wet pulp made of wood pulp
To form an absorption layer 2.

Waterproof paper (paper obtained by laminating polyethylene on wet absorbent paper, length 205 mm, width 95)
mm), the side face and the bottom face of the obtained absorbent layer 2 were covered with such waterproof paper. All surfaces of the combined body of the absorbent layer 2 and the poly-laminate paper are covered with a surface layer 1 (length 205 mm, width 172 mm) capable of absorbing body fluid, which will be described later, and are coated with a hot melt adhesive used as a fixing agent 6. Was fixed. Further, on the opposite side of the surface layer 1, a basis weight of 30 g / m ² , a width of 20 mm, and a length of 115 mm
2 hot melt adhesives were applied as adhesive portions 4.
Thus, a sanitary napkin having the configuration shown in FIG. 1 (product 1 of the present invention) was obtained.

As the surface layer 1, a polyethylene apertured film was used. This surface layer 1 has a basis weight of 30 g.
/ M ^{2, in which} a polyethylene film is perforated and the diameter of one hole is 0.5 mm and the area ratio of the holes is 20 mm.
It is the one that has a hole.

Example 2 A sanitary napkin having the structure shown in FIG. 1 was prepared in the same manner as in Example 1 except that the absorbent sheet D was used instead of the absorbent sheet A used in Example 1. Invention product 2) was obtained.

Example 3 A sanitary napkin having the structure shown in FIG. 3 was manufactured. That is, the absorbent sheet B having a length of 175 mm and a width of 145 mm was used as the absorbent sheet 10, and was folded and compressed in a C-shape so that both side edges thereof were almost at the center of the absorbent body, and the width was 73 mm. This absorbent sheet B was used as an absorbent layer. Thereafter, in the same manner as in Example 1, a sanitary napkin (product 3 of the present invention) having the configuration shown in FIG. 3 was obtained.

[Examples 4 to 6] As shown in FIG. 3, in the same manner as in Example 3 except that the absorbent sheets C, D, and E were used instead of the absorbent sheet B used in Example 3, respectively. Sanitary napkins of the present invention (products 4, 5, and 6 of the present invention, respectively) were obtained.

Comparative Example 1 A sanitary napkin having the structure shown in FIG. 7 was manufactured. That is, the weight is 300 g / m ² and the thickness is 4.
After spraying a small amount of water on fluff pulp 2a having a length of 175 mm and a width of 73 mm adjusted to 5 mm, superabsorbent polymer 2e [Aqualic CAW- manufactured by Nippon Shokubai Co., Ltd.
4 (trade name)] to the area of 60 mm in width and 175 mm in length, approximately 0.53 g is sprayed almost uniformly, and the spray basis weight is 50 g.
/ M ² . On top of this, a basis weight of 18 g / m ² and a length of 17
5 mm, 73 mm width wet pulp made of wood pulp 2
b, and all the surfaces of these combinations were weighed 18 g.
The absorbent layer 2 was formed by coating with a wet-type absorbent paper 2c made of wood pulp having a length of 175 mm and a width of 130 mm / m ² . After that, a sanitary napkin 100 (comparative product 1) having the configuration shown in FIG. 7 was produced in the same manner as in Example 1.

[Comparative Examples 2 to 4] FIG. 1 is similar to Example 1 except that the absorbent sheets F, G and H were used instead of the absorbent sheet A used in Example 1. The sanitary napkins having the above configurations (Comparative products 2, 3, and 4, respectively) were obtained.

[Comparative Examples 5 to 7] As shown in FIG. 3, in the same manner as in Example 3, except that the absorbent sheets F, I and J were used instead of the absorbent sheet B used in Example 3. Sanitary napkins of the constitution (Comparative Products 5, 6 and 7, respectively) were obtained.

For the products 1 to 6 of the present invention in Examples 1 to 6 and the comparative products 1 to 7 in Comparative Examples 1 to 7, in order to evaluate the polymer fixing ability and absorption performance, a polymer dropping test was carried out by the following method. The product thickness, absorption time, dynamic liquid return amount, and leak test were performed. Table 4 shows the results.

<Detachment test of superabsorbent polymer> Example 1
After the weights of the sanitary napkins of Comparative Examples 1 to 6 and Comparative Examples 1 to 7 were measured, the sanitary napkins were placed in a plastic bag with a chuck having a length of 280 mm and a width of 200 mm. After completion of the test, the change in weight of the sanitary napkin was measured, and the colored water (0.3 g / water 100 ml) dyed with Blue No. 1 was used so that the superabsorbent polymer dropped into the plastic bag could be easily observed with the naked eye. In addition to swelling the superabsorbent polymer in the plastic bag, the degree of shedding is visually determined. O: Almost no dropout of the superabsorbent polymer was observed. Δ: Some loss of the superabsorbent polymer was observed. ×: Dropping of the superabsorbent polymer is considerably observed. The measurement is performed 10 times, and the average value is defined as the dropout amount.

<Measurement of Product Thickness> As shown in FIG.
Ten sanitary napkins were superimposed, an acrylic plate weighing 500 g was placed from above, and the thickness of the ten sanitary napkins was measured to determine the product thickness per sheet.

<Absorption time (5 g), reabsorption time (10
g), Measurement of Dynamic Liquid Return Amount> An absorption rate measuring device shown in FIG. 12 was used. That is, the absorbent sheet 1 shown in FIG.
In place of 0, the sanitary napkins obtained in Examples 1 to 6 and Comparative Examples 1 to 7 were placed horizontally, an acrylic plate 20 having a 1 cm diameter injection port was placed, and a weight 22 was placed thereon. A load of 5 g / cm ² was applied to the sanitary napkin.
Next, 5 g of defibrillated horse blood (manufactured by Nippon Biotest Laboratory Co., Ltd.) is injected through the inlet, and the absorption time (second) until the defibrillated horse blood is completely absorbed is determined. After the defibrillated horse blood was completely absorbed, it was left as it was for 20 minutes, 5 g of defibrillated horse blood was injected again, the reabsorption time (10 g) was determined, and the same was left for 20 minutes. Then, 10 sheets of absorbent paper made of softwood pulp having a basis weight of 30 g / m ² and a length of 195 mm and a width of 75 mm are placed on the upper surface (skin contact surface side) of the sanitary napkin,
As shown in FIG. 16, shorts equipped with a sanitary napkin 80 were put on the movable female lumbar model 90 shown in FIG. 15, and then walked at a walking speed of 100 seconds / minute (50 m / minute) for one minute. After walking, the sanitary napkin 80 and ten pieces of absorbent paper were taken out, and the weight of the defibrated horse blood absorbed by the absorbent paper was determined as a liquid return amount (g). The measurement was carried out for each of the five points, and the respective average values were obtained, which were taken as the absorption time, re-absorption time, and dynamic liquid return amount.

<Leak test (number of leak occurrences)>
6 and sanitary napkins 80 obtained in Comparative Examples 1 to 7,
As shown in FIG. 16, after attaching to the movable female waist model 90 and putting on shorts, 100 steps / minute (50 m /
Minutes) at a walking speed of 10 minutes. Then, while walking, 5 g of the defibrillated horse blood was injected into the sanitary napkin 80 by the tube 91, and then the gait was allowed to walk at the same speed for 20 minutes (5 g absorption), and thereafter the defibrillated horse blood 5
g was infused for 20 minutes at the same speed (1
At each time point, the number of leaked sheets out of the 10 samples was counted.

[0164]

[Table 4]

As is clear from the results shown in Tables 3 and 4, the body fluid absorbent article of the present invention using an absorbent sheet in which the fiber web and the fiber aggregate are integrated and the superabsorbent polymer is contained therein. Is superior in the fixability of the superabsorbent polymer and extremely thin compared to a body fluid absorbent article having a conventional absorbent sheet (absorbent sheet obtained by water spraying, embossing integration or integration with an adhesive). It can be seen that even when the absorbent sheet having a thickness of 2 to 3 mm is used, the absorption characteristics such as the absorption rate and the liquid return amount are excellent.

In comparison between body fluid absorbent articles having a thickness of about 6 mm using fluff pulp (comparison between Examples 1-2 and Comparative Examples 1 and 2-4), fluff pulp was used in a large amount. Although the degree of improvement in absorbency is small, Examples 1-2
Body fluid-absorbing articles do not cause the superabsorbent polymer to fall off,
It can be seen that the fixability of the superabsorbent polymer is very excellent. In addition, it should be noted that although the structure of the absorbent sheet is different between Example 1 and Comparative Examples 2 to 4, they are manufactured from the same pulp.

As a more preferable use example of the body fluid absorbing article of the present invention, a body fluid absorbing article having a thickness of about 3 mm or less, which is about half or less the thickness of a conventional body fluid absorbing article using the above absorbent sheet. Products. Regarding that the thickness of the body fluid-absorbent article of the present invention can be made extremely thin, Examples 3 to
This is clear from the comparison between Comparative Example 5 and Comparative Examples 5 to 7.

[0168]

According to the present invention, it is possible to provide a body fluid-absorbing article which can fix a large amount of a high-absorbency polymer despite being extremely thin. In particular, using an absorbent sheet formed from bulky cellulose fibers,
When the body fluid absorbent article of the present invention is configured, not only the fixability of the superabsorbent polymer, but also the absorption rate of the body fluid increases,
It is possible to provide a bodily fluid absorbent article that is extremely thin and has high absorption performance, in which the amount of liquid returned is small and the number of leaks is small. Further, since the absorbent sheet has a structure in which the fiber web and the fiber aggregate are integrated and the superabsorbent polymer is held inside the absorbent sheet, the body fluid absorbing of the present invention including the absorbent sheet is provided. Even when the absorbent article is worn and exercises violently, there is no possibility that the superabsorbent polymer separates from the absorbent sheet to lower the absorption performance. Furthermore,
Since the absorbent sheet contains the superabsorbent polymer in advance therein, equipment for spraying the superabsorbent polymer in the final processing process of manufacturing the bodily fluid absorbent article of the present invention is also unnecessary, and is simplified. Processing equipment can be provided. Moreover, when the absorbent layer is composed of only the above-mentioned absorbent sheet, only one absorbent sheet needs to be cut, and the processing equipment is extremely simple and capable of high-speed production.

[Brief description of the drawings]

FIG. 1 is a schematic diagram showing a cross section of a sanitary napkin as a first embodiment of a body fluid absorbent article of the present invention.

FIG. 2 is a schematic view showing a cross section of a sanitary napkin as a second embodiment of the body fluid absorbent article of the present invention.

FIG. 3 is a schematic diagram showing a cross section of a sanitary napkin as a third embodiment of the body fluid absorbent article of the present invention.

FIG. 4 is a schematic diagram showing a cross section of a sanitary napkin as a fourth embodiment of the body fluid absorbent article of the present invention.

FIG. 5 is a schematic view showing a cross section of a sanitary napkin as a fifth embodiment of the body fluid absorbent article of the present invention.

FIG. 6 is a schematic view showing a cross section of a sanitary napkin as a sixth embodiment of the body fluid absorbent article of the present invention.

FIG. 7 is a schematic view showing a cross section of a conventional sanitary napkin.

FIG. 8 is a schematic view showing a cross section of an absorbent sheet.

FIG. 9 is a schematic view showing a cross section of a preferred absorbent sheet.

FIG. 10 is a schematic view showing a cross section of a conventional absorbent sheet.

FIG. 11 is a schematic view illustrating a preferred method for producing an absorbent sheet.

FIG. 12 is a schematic diagram illustrating measurement of an absorption rate.

FIG. 13 is a schematic diagram illustrating measurement of a liquid return amount.

FIG. 14 is a schematic diagram illustrating measurement of the thickness of a sanitary napkin.

FIG. 15 is a diagram illustrating a movable female waist model.

FIG. 16 is a schematic diagram showing a state in which a sanitary napkin is attached to a crotch of a movable female waist model.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Surface layer which can absorb bodily fluid 2 Absorbent layer which retains bodily fluid 3 Leakproof layer which is impermeable to bodily fluid 4 Adhesive part 5 Release paper 6 Joint part 10 Absorbent sheet 12 Absorbing surface 15 Fiber aggregate 16 Highly absorbent polymer 18 Fiber Web 30, 31 Tissue 40 Forming part 42 Suction dewatering process 44 Press part 46 Dryer 100 Sanitary napkin

──────────────────────────────────────────────────続 き Continuation of front page (56) References JP-A-6-70953 (JP, A) (58) Fields investigated (Int. Cl. ⁶ , DB name) A61F 13/15 A61F 13/46

Claims (7)

(57) [Claims] 1. A bodily fluid absorbent article comprising at least a bodily fluid retaining absorbent layer and a bodily fluid impermeable leakproof layer, wherein the absorbent layer comprises at least a hydrophilic fiber and a heat-meltable adhesive fiber or a paper strength agent. And an absorbent sheet containing a superabsorbent polymer, the absorbent sheet comprising a fiber aggregate and a fiber web.
And the fiber aggregate and the fiber web
And the fiber aggregate, the absorbent sheet absorbs body fluid
It has an absorbing surface and the high absorbing property on the absorbing surface side
Contains no polymer, the fiber web is formed from at least the hydrophilic fiber
It is, the superabsorbent polymer is not present in the absorbent surface,
Mainly dispersed and arranged in the fiber web, and adhered and fixed to the hydrophilic fibers constituting the absorbent sheet; / M ²
The body fluid absorbent article, wherein the absorbent sheet is constituted by an absorbent sheet having a thickness of 0.3 to 1.5 mm. 2. The fiber aggregate has a basis weight of 10 to 200 g.
/ M ² , and the basis weight of the fiber web is 10 to 200 g / m ² ,
The body fluid absorbent article according to claim 1 . Wherein the hydrophilic fibers are bulky cellulose fibers, according to claim 1 or 2 Symbol mounting body fluid absorbent article. 4. The bodily fluid absorbent article according to claim 3 , wherein the bulky cellulose fiber has a fiber roughness of 0.3 mg / m or more. 5. The body fluid absorbent article according to claim 3 , wherein the bulky cellulose fiber has a roundness of a fiber cross section of 0.5 to 1. 6. The body fluid absorbent article according to claim 3 , wherein the bulky cellulose fiber is a crosslinked cellulose fiber. 7. A bodily fluid absorbent article comprising at least a bodily fluid retaining absorbent layer and a bodily fluid impermeable leakproof layer, wherein the absorbent layer is made of bulky hydrophilic fiber and hot-melt adhesive fiber or paper strength. Fiber webs and fiber collections formed from reinforcing agents
Fiber sheet composed integrally with the main body
An absorbent sheet comprising a fibrous structure and a superabsorbent polymer particle, wherein the superabsorbent polymer particle is not present on the absorbent surface where the absorbent sheet absorbs body fluid, The absorbent sheet is dispersed and fixed in the structure, the thickness of the absorbent sheet is 0.3 to 1.5 mm,
The spray basis weight of the superabsorbent polymer is 20 to 70 g / m ^2.
The absorbent article according to any one of claims 1 to 3, wherein the absorbent article does not have a sense of incongruity due to absorption and swelling of body fluid during use.