JPH08229070A - Body field-absorbing article - Google Patents

Abstract

PURPOSE: To provide a body fluid-absorbing article having a paper-like thin absorbing sheet surely fixed with a high-absorption polymer by burying the high-absorption polymer in the space formed between the fibers constituting the absorbing sheet of the body fluid absorbing article in the wet state of the fibers. CONSTITUTION: A sanitary napkin 100 is provided with a body fluid absorbing surface layer 1, a body fluid-nonpermeable leakproof layer 3, and a body fluid holding absorbing layer 2 inserted between them. The absorbing layer 2 is an absorbing sheet containing at least hydrophilic fibers, heat-soluble adhesive fibers or a paper force reinforcing material, and a high-absorption polymer. The high-absorption polymer does not exist in the absorption surface where the absorbing sheet absorbs a body fluid, it is dispersedly arranged in the absorbing sheet, and it is stuck and fixed to the hydrophilic fibers constituting the absorbing sheet. The distributed weighing of the high-absorption polymer is set to 5-300 g/m<2> , and the thickness of the absorbing sheet is set to 0.3-1.5mm.

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 hygene pad, a disposable diaper, a medical pad, and a breast milk pad, and more specifically, a bodily fluid absorbent article including an absorbent sheet that does not drop out of the superabsorbent polymer and has high absorption performance. It is about.

[0002]

2. Description of the Related Art Conventionally, the problems to be solved by the invention
The absorbent body in a body fluid absorbent article such as a sanitary napkin or a paper diaper is mainly composed of fluff pulp, absorbent paper and a superabsorbent polymer. In particular, the super-absorbent polymer has a large absorption capacity and has the property of once absorbing body fluid to form a gel and not leaking out.
At present, it is used in most body fluid absorbent articles.

However, while the superabsorbent polymer has such characteristics, its shape is powder,
There is a technical problem that it easily falls off (the super absorbent polymer leaks from the body fluid absorbent article). In addition, there is a problem that it is desired to further enhance the inherent absorption capacity of the superabsorbent polymer. In particular, the dropout of the superabsorbent polymer is a fatal problem in product performance including the absorbability, so various techniques have been proposed for the purpose of preventing (fixing) the dropout.

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,
It is not possible to immobilize large amounts of superabsorbent polymer. Therefore, when such an absorbent sheet is used as, for example, an absorbent body of a body fluid absorbent article, the super absorbent 16 polymer is separated from the tissues 30, 31 due to the motion of the wearer, and the space between the tissues 30, 31 is increased. There is a case where a space is created and the liquid accumulates.

US Pat. No. 3,670,731 discloses a method in which a superabsorbent polymer is dispersed between two paper layers,
It is disclosed to be embossed or quilted to hold the superabsorbent polymer in place. However, this method also has the same drawbacks as the above-mentioned roller pressure bonding method.

Further, Japanese Patent Publication No. 59-26467, Japanese Patent Laid-Open No. 54-123293 and Japanese Patent Laid-Open No. 54-141.
No. 099 gazette discloses that by spraying steam or spraying water on a tissue to moisten the tissue and then spraying a superabsorbent polymer to give tackiness to the superabsorbent polymer. Immobilizing superabsorbent polymers is disclosed. Further, as shown in FIG. 7, in the sanitary napkin 100, after water is sprayed on the fluff pulp 2a, the super absorbent polymer 2e is placed on the fluff pulp 2a.
An absorbent body is also used in which the absorbent paper 2b is sprinkled, the absorbent paper 2b is superposed thereon, and the absorbent paper 2c is further covered with the absorbent paper 2c. According to these methods, the superabsorbent polymer can be fixed to some extent, but it cannot be completely prevented from falling off, and the fixing amount is still insufficient. Further, upon absorption of body fluid, the superabsorbent polymer swells in a layered form, and in some cases, absorption inhibition due to gel blocking or the like may occur.

Further, Japanese Patent Laid-Open No. 61-132697 discloses
In the papermaking process, is a highly absorbent polymer on the paper before drying.
After spraying the polymer, dry it
A method for producing absorbent paper containing mer is described.
It According to this method, a certain amount of superabsorbent polymer
Can be fixed in the paper, but the fixed amount is at most 10 g / m
²It is a degree, and it cannot be said that the amount is sufficient. Also, profit
In the absorptive absorbent sheet, even on the surface that absorbs liquid
Due to the presence of superabsorbent polymers, such high absorption
The absorbable polymer is produced by dynamic action such as friction.
It has the drawback that it can easily fall off.

Further, a method is 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 of the superabsorbent polymer and absorption of body fluid are inhibited.

As another method for fixing the superabsorbent polymer using the hot melt adhesive, there is a method of applying the hot melt adhesive in a spiral shape. According to this method, the above-mentioned swelling inhibition and absorption inhibition are small, and moreover, the superabsorbent polymer can be fixed efficiently. However, the spiral coating of the hot melt adhesive complicates the manufacturing process and equipment. Furthermore, since a large amount of superabsorbent polymer is fixed in a layered form, gel absorption of the superabsorbent polymer occurs when absorbing body fluid, and swelling inhibition of the liquid occurs.

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 highly-blended 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 drawback that when absorbing a liquid, the superabsorbent polymer swells, breaks the absorbent sheet and protrudes to the outside. Further, in order to increase the surface strength of the absorbent sheet, crepe paper may be laminated, but in this case, there is a problem that the cost becomes high.
Moreover, in any case, the fixation of the superabsorbent polymer to the wood pulp is insufficient, and the problem that the superabsorbent polymer is likely to fall off is not solved. Further, when the absorbent sheet is strongly compressed, there is a problem that the liquid absorption rate is unavoidably reduced.

In addition to the above-mentioned absorbent sheet, a method is also known in which a superabsorbent polymer is directly polymerized on a non-woven fabric as a base material and fixed on the non-woven fabric to obtain an absorbent sheet. However, when a non-woven fabric composed of hydrophilic fibers is used as the non-woven fabric, the superabsorbent polymer obtained as a result of the polymerization does not become particulate and is immobilized almost uniformly on the entire non-woven fabric, so the amount of liquid absorbed Has the disadvantage that it will decrease. On the other hand, when a non-woven fabric composed of hydrophobic fibers is used as the non-woven fabric, unlike the above-mentioned non-woven fabric composed of hydrophilic fibers, the superabsorbent polymer obtained as a result of the polymerization becomes particulate, but the whole absorbent sheet Since it is hydrophobic, it has a drawback that the absorption rate of liquid is slow. Moreover, in these methods, the unreacted monomer remains inevitable, so that the use of the absorbent sheet is limited from the viewpoint of safety of the monomer to the human body.

US Pat. Nos. 4,605,402 and 5,021,050 are manufactured by superposing a fiber layer on a fiber web sprinkled with a superabsorbent polymer. Also disclosed is an absorbent body in which a superabsorbent polymer is dispersed and adhered to fibers in the central portion in the thickness direction. Although these absorbers are compressed and thinned at the time of manufacturing, they are not formed into a sheet and are still thick for use in various applications. Also, since the density is low, the surface absorbency is weak. Furthermore, when absorbing and wetting a liquid, the elasticity of synthetic fibers is used to restore the original thickness in order to obtain an absorption space, which is insufficient for thinning a body fluid absorbent article.

Therefore, an object of the present invention is to use as an absorbent sheet used as an absorbent layer, a thin absorbent sheet in a paper-like form in which the superabsorbent polymer is securely fixed without impairing the original absorption characteristics of the superabsorbent polymer. The object of the present invention is to provide a bodily fluid-absorbent article including a permeable sheet.

Further, an object of the present invention is 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 the original absorption characteristics of the superabsorbent polymer can be exhibited. 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 sensation, and does not cause discomfort even after absorbing liquid.

[0016]

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

The present invention has been made on the basis of the above findings, and in a body fluid absorbent article comprising at least a body fluid retaining absorbent layer and a body fluid impermeable leakproof layer, the absorbent layer is at least hydrophilic. An absorbent sheet comprising fibers and hot-melt adhesive fibers or a paper strength agent and a superabsorbent polymer; the superabsorbent polymer not being present on the absorbent surface where the absorbent sheet absorbs body fluids, The absorbent sheet is dispersed and arranged inside, and is fixed by adhering to the hydrophilic fibers constituting the absorbent sheet; the basis weight of the superabsorbent polymer is 5 to 300 g / m ² . Yes; the above object is achieved by providing a body fluid absorbent article, characterized in that the absorbent sheet is composed of an absorbent sheet having a thickness of 0.3 to 1.5 mm.

The present invention also provides a body fluid-absorbing article comprising at least a body fluid-retaining absorbent layer and a body fluid-impermeable leak-proof layer, wherein the absorbent layer is a bulky hydrophilic fiber and a hot-melt adhesive. An absorbent sheet comprising a fibrous structure formed of fibers or a paper-strengthening agent and superabsorbent polymer particles, wherein the superabsorbent polymer particles are on the absorbent surface where the absorbent sheet absorbs body fluid. Is absent, is dispersed and fixed in the fibrous structure, the thickness of the absorbent sheet is 0.3 to 1.5 mm, and the spreading basis weight of the superabsorbent polymer is 20 to 70 g / m ^2. The present invention provides a body fluid absorbent article, which is characterized by having no discomfort due to absorption and swelling of body fluid during use.

In the present specification, the "fiber web" means
In the wet state before spraying the superabsorbent polymer, the constituent fibers are not restrained at all with each other, or are restrained only slightly due to mechanical entanglement and frictional force and have a very high degree of freedom. And, after the drying, the constituent fibers mean an aggregate of fibers in which the constituent fibers are strongly bound to each other to form a sheet, and the "fiber aggregate" is formed mainly of fibers and is in a sheet form. In addition to ordinary paper, non-woven fabric, woven fabric, and the like, it also includes the above fiber web, and the "fiber structure" means the above fiber web and the above fiber assembly. It means a sheet-like material of fibers integrally constituted mainly of.

[0020]

BEST MODE FOR CARRYING OUT THE INVENTION 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 will be taken as an example of a body fluid absorbent article, but the present invention is also applicable to other body fluid absorbent articles such as a hygiene pad, a disposable diaper, a medical pad and a breast milk pad. You can Also,
The constituent materials of the body fluid absorbent article, the manufacturing method, and the like can be freely modified within the range of the conventional technique as long as they do not depart from the requirements of the present invention.

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. 2 to 6 are schematic views (corresponding to FIG. 1) showing cross sections 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
It comprises a surface layer 1 capable of absorbing body fluid, a body fluid impermeable leak preventive layer 3, and a body fluid retaining absorbent layer 2 interposed between the surface layer and the leak preventive layer.

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

The absorbent layer 2 includes an absorbent sheet 10, a fluff pulp 2a, and the absorbent sheet 10 as described later.
And an absorbent paper 2b for covering the fluff pulp 2a. The leakproof layer 3 covers the side surface portion and the bottom surface portion of the absorbent layer 2. The surface layer 1 covers all the surfaces of the combination of the absorption layer 2 and the leakproof layer 3.

The surface layer 1 is not particularly limited as long as it allows body fluids to permeate into the absorbent layer 2, but one having a feeling close to that of underwear is particularly preferable.
Examples of such a surface layer include, for example, thermoplastic resin woven fabrics, nonwoven fabrics, and porous films. In particular, an apertured film made of 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 body fluids, but it is preferable that it has moisture permeability and a feel close to that of underwear. The body fluid impermeable leakproof layer having moisture permeability is, for example, one obtained by adding a filler of an inorganic compound or an organic compound to a thermoplastic resin,
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 of the sanitary napkin 100 that contacts the underwear, two adhesive parts 4, 4 are formed in a streak pattern in the longitudinal direction, and the adhesive parts 4, 4 are peeled off before use. Paper 5
Protected by. Further, in FIG. 1, reference numeral 6
Is a joint for joining the above members. In addition, the other points which are not described in detail are the same as those of the conventional sanitary napkin.

Next, the characteristic parts 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 hydrophilic fibers and hot-melt adhesive fibers or paper-strengthening agents and superabsorbent polymers;
The superabsorbent polymer does not exist on the absorbent surface where the absorbent sheet absorbs body fluids, is dispersed and arranged inside the absorbent sheet, and adheres to the hydrophilic fibers constituting the absorbent sheet. The fixed basis; the basis weight of the superabsorbent polymer 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 absorbent article in which the superabsorbent polymer does not fall off and gel is blocked. Moreover, since such an absorbent sheet has functions of absorbing / permeating and diffusing body fluid and retaining body fluid in its single structure, it has the above-mentioned functions like a conventional body fluid absorbent article. Since it is not necessary 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).
The thickness (0.2 to 1.0 mm) of the surface layer, the leak-proof layer, etc. is added to, and it is extremely thin. The details of the absorbent sheet will be described later.

First of the body fluid absorbent article of the present invention shown in FIG.
According to a preferred embodiment of the above, the body fluid is absorbed by the sanitary napkin 100 through the surface layer 1. After that, the fluff pulp 2a permeates and is absorbed and retained by the superabsorbent polymer dispersed in the absorbent sheet 10. In this case, it is preferable to arrange the absorbent sheet 10 such that the fiber assembly having the absorbent surface is located on the surface layer 1 side. The absorbent sheet 10
By arranging in this way, the fluff pulp 2a
Body fluid absorbed by the absorbent sheet 10 more smoothly
The desirable effect of leading to

As described later, the absorbent sheet 10 described above.
Is because the superabsorbent polymer is securely fixed without impairing the original absorption characteristics of the superabsorbent polymer,
Sanitary napkin 10 comprising the absorbent sheet 10
0 has a large retention capacity of body fluid. Moreover, since the sanitary napkin 100 shown in FIG. 1 also includes the fluff pulp 2a in addition to the absorbent sheet 10, the body fluid holding capacity is further increased. Therefore, the body fluid absorbent article of the present embodiment is suitable as a night-use sanitary napkin that is 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 embodiment, the same points as those in the first embodiment will not be described in detail, but the detailed description in the first embodiment will be applied as appropriate. 2 to 6, the same members as those in FIG. 1 are designated by the same reference numerals.

Second of the body fluid absorbent article of the present invention shown in FIG.
In the sanitary napkin 100 as a preferred embodiment of 1., the absorbent layer is composed only of the absorbent sheet 10, and the side surface portion and the bottom surface portion of the absorbent sheet 10 are covered with the leak-proof layer 3. . The surface layer 1 covers all the surfaces of the combination of the absorbent sheet 10 and the leakproof layer 3. In the present embodiment as well, similar to the first embodiment, the absorbent sheet 10 is preferably arranged such that the fiber assembly having the absorbent surface is located on the surface layer 1 side. .

Since the sanitary napkin 100 has a small number of members and the respective members are thin, the sanitary napkin 100 can be an extremely thin sanitary napkin.
Further, since the superabsorbent polymer is reliably fixed to the absorbent sheet 10 without impairing the original absorption characteristics of the superabsorbent polymer, it has a large body fluid holding capacity although it is thin. As a result, it is possible to obtain a sanitary napkin which has a comfortable fit and has a large body fluid holding capacity.

Third embodiment of the body fluid absorbent article of the present invention shown in FIG.
In the sanitary napkin 100 as the preferred embodiment of 1., the absorbent layer is composed only of the absorbent sheet 10, and the absorbent sheet 10 is bent in a C shape. The side surface and the bottom surface of the absorbent sheet 10 are covered with the leak preventive layer 3. Further, the surface layer 1 covers all the surfaces of the combination of the absorbent sheet 10 and the leakproof layer 3. In the present embodiment, it is preferable that the absorbent sheet 10 is bent and arranged so that the fiber assembly having the absorbent surface is located on the surface layer 1 side.

Although the sanitary napkin 100 is thicker than the sanitary napkin shown in FIG. 2 because the absorbent sheet 10 is bent in a C shape, it is still thick.
The absorbent layer 2 can be made thinner than the sanitary napkin shown in FIG. 1, which uses fluff pulp. Moreover, since the absorbent sheet 10 is bent into a C shape, the body fluid holding capacity is large. As a result, it is possible to obtain a sanitary napkin which has a comfortable fit and has a large body fluid holding capacity.

The fourth of the bodily fluid absorbent article of the present invention shown in FIG.
In the sanitary napkin 100 as a preferred embodiment of the above, the absorbent layer includes the absorbent sheets 10, 10, ...
Are stacked (three in FIG. 4).
Then, the absorbent sheets 10, 10, ...
The side surface portion and the bottom surface portion thereof are covered with the leak-proof layer 3. Further, the absorbent sheets 10, 10, ...
The surface layer 1 covers all the surfaces of the combination of the above and the leakproof layer 3. In the present embodiment as well, similar to the first embodiment, the absorbent sheet 10 is preferably arranged such that the fiber assembly having the absorbent surface is located on the surface layer 1 side. .

Although the sanitary napkin 100 is thicker than the sanitary napkin shown in FIG. 2 by the number of the absorbent sheets 10 stacked, the fluff pulp is still used in the absorbent layer 2. It can be thinner than the sanitary napkin shown in FIG. Moreover, since a plurality of the absorbent sheets 10 are stacked, the body fluid holding capacity is large. As a result, it is possible to obtain a sanitary napkin which has a comfortable fit and has a large body fluid holding capacity.

Fifth of the bodily fluid absorbent article of the present invention shown in FIG.
In the sanitary napkin 100 as a preferred embodiment of the above, the absorbent sheet 10 has the functions of 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 comprises an absorbent sheet 10 in which a surface layer capable of absorbing body fluid and a body fluid-retaining absorbent layer are integrated.
The side surface portion and the bottom surface portion are covered with the leakproof layer 3. In the present embodiment, it is particularly preferable to arrange the absorbent sheet 10 so that the fiber assembly having the absorbent surface is located on the side 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, it is possible to obtain a sanitary napkin which is comfortable to wear and can be manufactured by a simple process at low cost.

Sixth of the bodily fluid absorbent article of the present invention shown in FIG.
In the sanitary napkin 100 as a preferred embodiment of, the absorbent sheet is a surface layer capable of absorbing body fluid,
It has the three functions of an absorbent layer that retains body fluid and a leak-proof layer that is impermeable to body fluid. That is, the sanitary napkin 100 of the present embodiment is formed by integrating a body fluid-absorbable surface layer, a body fluid-retaining absorption layer, and a body fluid-impermeable leak-proof layer. More specifically, it comprises the absorbent sheet 10 and a body fluid impermeable sheet 3'joined and integrated with the surface of the absorbent sheet opposite to the body fluid absorbing surface. In addition, in the present embodiment, the absorbent sheet 10 is arranged so that the fiber assembly having the absorbing surface is located on the side that absorbs body fluid, and the body fluid impermeable to the surface opposite to the absorbing surface. It is particularly preferable to bond the permeable sheet 3 '.

In the sanitary napkin 100, the number of constituent members is reduced and the thickness can be further reduced. As a result, it is possible to obtain a sanitary napkin that has a more comfortable fit and can be manufactured by a simpler process at low cost. The bodily fluid-absorbent article of the present embodiment, in addition to the sanitary napkin as shown in FIG.
It is also suitable as a body fluid absorbent article such as a breast milk pad or a hygiene pad that absorbs a small amount of body 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 hydrophilic fibers and heat-meltable adhesive fibers or paper reinforcing agent, and a superabsorbent polymer 16.
In addition, the absorbent sheet 10 has an absorbent surface 12 that absorbs body fluid, and the superabsorbent polymer 16 does not exist on the absorbent surface 12, and the superabsorbent polymer 16 is included in the absorbent sheet 10 of the absorbent sheet 10. It is distributed inside. In addition, the superabsorbent polymer 16 is adhered to the hydrophilic fibers forming the absorbent sheet 10.

The absorbent sheet 10 preferably comprises a fiber assembly 15 and a fiber web 18 as shown in FIG. The fiber assembly 15 has an absorbent surface 12 and does not include the superabsorbent polymer 16 on the absorbent surface 12 side. On the other hand, the above fiber web 1
8 is composed of at least a hydrophilic fiber. Further, as shown in FIG. 9, the fiber assembly 15 and the fiber web 18 are integrated. Furthermore, the superabsorbent polymer 16 is mainly arranged inside the fibrous web 18.

As described above, the preferred embodiment of the absorbent sheet 10 has an integral structure including the fiber assembly 15 and the fiber web 18 and the superabsorbent polymer 16 contained therein. This is one of the features. More specifically, in the absorbent sheet 10, mechanical entanglement between the fibers forming the fiber assembly 15 and the fibers forming the fiber web 18, hydrogen bonding (and a paper reinforcing agent), and heat fusion. The fiber aggregate 15 and the fiber web 18 are integrated by wearing. By having such a structure, the superabsorbent polymer 16 can be reliably fixed inside the absorbent sheet, and can be prevented from falling off. Moreover, the permeability of the body fluid absorbed from the absorbent surface 12 is further improved, and reaches the superabsorbent polymer 16 smoothly. Further, gel blocking of the superabsorbent polymer 16 that has absorbed body fluid can also be suppressed. Therefore,
The absorbent sheet 10 is a conventional absorbent sheet in which a super absorbent polymer is sandwiched between two sheets of absorbent paper (see FIG. 1).
0) (that is, the conventional absorbent sheet has two plies, but the absorbent sheet 10
Is a sheet). Such integration is preferably achieved by superposing wet papermaking, as described below.

In the absorbent sheet 10 shown in FIG. 8, on the side opposite to the absorbent surface 12, sized absorbent paper or a water-repellent non-woven fabric such as polyethylene or polypropylene is used as a meltblown material. It is also preferable to bond. Such an absorbent sheet is particularly preferable when the sanitary napkin as in the sixth embodiment (FIG. 6) of the body fluid absorbent article of the present invention described above is manufactured.

The fibrous web 18 is in a wet state before the superabsorbent polymer 16 is sprinkled, and it is important that the fibers constituting the fibrous web 18 have an extremely high degree of freedom with respect to each other. . Fiber web 1 in this state
By dispersing the superabsorbent polymer 16 on the surface 8, the superabsorbent polymer 16 is three-dimensionally dispersed and fixed in the fibrous web 18, that is, from the surface to the inside. Further, the fibrous web 18 has such strength that the superabsorbent polymer 16 does not deposit on the surface of the absorbent sheet 10 after the fibrous web 18 and the fiber assembly 15 are integrated. That is also important. For this purpose, the fibrous 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 will be described later, a hot-melt adhesive fiber or a paper-strengthening agent is blended. It is also preferable to further 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 ~ It is 80 g / m ² . The basis weight is 1
If it is less than 0 g / m ² , the superabsorbent polymer 16 will be swelled when the superabsorbent polymer 16 is swollen.
May protrude and fall off. On the other hand, if the basis weight exceeds 200 g / m ² , the density of the fibrous web increases too much, the absorbent sheet 10 becomes too hard, and the superabsorbent polymer 16 cannot be fixed three-dimensionally, or body fluid Since the transparency may be deteriorated or the wearing feeling may be deteriorated, it is preferably within the above range.

The fibrous web contains at least hydrophilic fibers. As such a hydrophilic fiber, any fiber having a hydrophilic surface can be used without particular limitation as long as it can form a fiber web in which the fibers have extremely high degrees of freedom in the 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. Examples thereof include hydrophilic synthetic fibers such as, and synthetic fibers such as polyethylene fibers, polypropylene fibers, and polyester fibers that have been hydrophilized with a surfactant, but are not limited thereto. These hydrophilic fibers may be used alone or in combination of two or more.

The hydrophilic fiber is the same as the fiber web 100 described above.
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.

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

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

Examples of preferable 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 are accumulated in a bulky state, and a bulky network structure is easily formed in the fiber web. In addition, the movement resistance of body fluid is small and the passage speed of body fluid is high, which is preferable.

In the present invention, the "fiber roughness" means a fiber having a non-uniform thickness, such as wood pulp,
It is used as a scale showing the thickness of the fiber, and 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 a fiber roughness of 0.3 to 2 mg / m, and further more preferably a fiber. The roughness is 0.32 to 1 mg / m.

Examples of cellulose fibers having a fiber roughness of 0.3 mg / m 2 or more include softwood kraft pulp (Federal).
"ALBACEL" (trade name) made by Paper Board Co., and PT
Inti Indorayon Utama's "INDORAYON" (brand name) etc. are mentioned.

Another preferred example of the above-mentioned bulky cellulose fiber is a cellulose fiber having a roundness of the fiber cross section of 0.5 to 1, particularly preferably 0.55 to 1. Cellulose fibers having a circularity of the fiber cross section of 0.5 to 1 are preferable because the migration resistance of body fluid is low and the permeation rate of body fluid is high. The method for measuring the roundness of the fiber cross section will be described later.

As mentioned above, it is preferable to use wood pulp as the cellulose fiber, but generally the cross section of the wood pulp is flat due to the delignification treatment, and most of the roundness thereof 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.

Thus, as the bulky cellulose fiber, mercerized pulp having a circularity of 0.5 to 1 obtained by mercerizing wood pulp is also preferable.
An example of a commercially available mercerized pulp that can be used in the present invention is "FILTRAN I" manufactured by ITT Rayonier Inc.
"ER" (brand name) and "POROSANIER" (brand name) manufactured by the same company.

When the fiber roughness is 0.3 mg / m or more,
In addition, it is preferable to use a cellulose fiber having a roundness of the fiber cross section of 0.5 to 1 because a bulky network structure is more easily formed and a body fluid passage speed is further increased.

Another preferable example of the bulky cellulose fiber is a crosslinked cellulose fiber obtained by crosslinking the inside and / or the inside of the cellulose fiber. Such crosslinked cellulose fibers are preferable because they 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 cross-linking agents include N-methylol compounds such as dimethylol ethylene urea and dimethylol dihydroxy ethylene urea; polycarboxylic acids such as citric acid, tricarballylic acid and butane tetracarboxylic acid; polyols such as dimethyl hydroxyethylene urea. ;
Examples thereof include cross-linking agents for polyglycidyl ether compounds. In particular, a cross-linking agent of a polycarboxylic acid or a polyglycidyl ether-based compound that does not generate formalin or the like which is harmful to the human body during cross-linking is preferable.

The amount of the cross-linking agent used is preferably 0.2 to 20 parts by weight with respect to 100 parts by weight of the cellulose fibers. If the amount used is less than 0.2 parts by weight, the cross-linking density of the cellulose fibers is low, so the elastic modulus may decrease significantly when wet, and if the amount used exceeds 20 parts by weight, the cellulose fibers will be Since the cellulose fiber may become too rigid and become brittle when stressed, the above range is preferable.

In order to crosslink the above-mentioned cellulose fibers with the above-mentioned crosslinking agent, for example, an aqueous solution of the above-mentioned crosslinking agent is impregnated with the above-mentioned cellulose fibers by adding a catalyst to the aqueous solution of the above-mentioned crosslinking agent to design an aqueous solution of the crosslinking agent. The cellulose fibers are dehydrated so that the adhesion amount is obtained, and then heated to the crosslinking temperature, or
Alternatively, an aqueous solution of a cross-linking agent is sprayed onto the above-mentioned cellulose fibers by spraying or the like so as to have a designed adhesion amount, and then heated to a cross-linking temperature to cause a cross-linking reaction.

Commercially available cross-linked cellulose fibers include “High Bulk Additiv” manufactured by Weyerhaeuser Paper Co.
e ”and the like.

In addition to the above-mentioned bulky cellulose fibers, bulky cellulose obtained by crosslinking the cellulose fibers such as pulp having a fiber roughness of 0.3 mg / m 2 or more by intramolecular and / or intermolecular by the above-mentioned 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 crosslinking the mercerized pulp having a roundness of the fiber cross section of 0.5 to 1 in the molecule and / or between the molecules 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 the fiber cross section of 0.5 to 1 (particularly, an average fiber length of 2 to 5 mm) is also preferable.

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

Particularly preferred bulky cellulose fibers are those obtained by mercerizing pulp having a fiber roughness of 0.3 mg / m or more to a roundness of 0.5 to 1, and then crosslinking the pulp by the above-mentioned method. is there.

In order to keep the structure of the absorbent sheet stable even when it is wet, it is necessary to impart wet strength to the fibrous web. For this reason, the heat-fusible adhesive fiber or paper is used. Contains a strength enhancer.

Further, in order to strengthen the hydrogen bond between the fibers of the cellulose fiber and improve the strength of the absorbent sheet, the ordinary cellulose fiber, that is, wood pulp, is used in place of the heat-melting adhesive fiber or the paper-strengthening agent. It is also effective to add non-wood pulp or the like. However, in order to sufficiently obtain the strength of the absorbent sheet when it is wet, it is preferable to use it in combination with the hot-melt adhesive fiber or the paper-strengthening agent.

As the above-mentioned hot-melt 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,
In addition, polyvinyl alcohol-polyester composite fiber and the like can be mentioned. When the conjugate fiber is used, both the core-sheath type conjugate fiber and the side-by-side type conjugate fiber can be used. These heat-meltable adhesive fibers may be used alone or in combination of two or more. Examples of the heat-meltable adhesive fiber preferably used in the present invention include polyvinyl alcohol fiber soluble in hot water and core-sheath type polyester fiber.

In general, the above-mentioned heat-meltable adhesive fiber preferably has a fiber length of 2 to 60 mm and a fiber diameter of 0.
It is preferably 1 to 3 denier (particularly 0.5 to 3 denier).

As described above, the fiber web has
A polyamine / epichlorohydrin resin, a dialdehyde starch, sponge, carboxymethylcellulose, etc., as a paper strength agent are added. 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.

When the heat-melting adhesive fiber is used, the fiber web contains 30 to 99 parts by weight of the hydrophilic fiber and 1 to 50 parts by weight of the heat-melting adhesive fiber based on 100 parts by weight of the fiber web. It is preferable that 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 heat-meltable adhesive fiber are used.
It comprises 30 parts by weight.

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

As another example, the fibrous web preferably contains 1 to 30 parts by weight, more preferably 5 to 20 parts by weight, of the heat-meltable adhesive fiber having a core-sheath structure.
Specific examples of the heat-meltable adhesive fiber having a core-sheath structure include a 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, Moreover, a synthetic fiber having a core-sheath structure having a polypropylene resin or a polyester resin as a core can be mentioned.

On the other hand, when the above paper strength agent is used, 3 parts by weight of the hydrophilic fiber is used 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 fiber, and 0.01 of the paper-strengthening agent are used.
~ 20 parts by weight.

For example, the fibrous web contains 30 to 99 parts by weight of the bulky cellulose fibers, 1 to 70 parts by weight of the wood pulp or non-wood pulp, and the paper strength based on 100 parts by weight of the fibrous web. Reinforcing agent 0.01 to 30
It is preferable to comprise 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 non-wood pulp, and 0.0% of the paper strength reinforcing agent.
It comprises 1 to 20 parts by weight.

Next, the super absorbent polymer 16 contained in the absorbent sheet 10 will be described. FIG.
As shown in FIG. 3, the superabsorbent polymer 16 is contained inside the absorbent sheet 10, and the absorbent sheet 1
It is dispersed in the space formed between the fibers that make up 0. More specifically, as shown in FIG. 9, the superabsorbent polymer 16 is mainly provided inside the fibrous web 18,
That is, it is preferably contained from the interface between the fiber web 18 and the fiber assembly 15 to the inside of the fiber web 18 and dispersed in the space formed between the fibers forming the fiber web 18. . As a result, the superabsorbent polymer 16 is reliably fixed in the absorbent sheet and gel blocking is suppressed. Note that, here, “the superabsorbent polymer is contained inside the absorbent sheet” does not mean that the superabsorbent polymer does not exist on the surface of the absorbent sheet at all, and will be described later. In the preferred manufacturing method of the absorbent sheet, a trace amount of the superabsorbent polymer unavoidably present on the surface of the absorbent sheet is acceptable, and most of the superabsorbent polymer is inside the absorbent sheet. It exists.

The superabsorbent polymer 16 is adhered to the hydrophilic fibers forming the absorbent sheet 10, preferably the hydrophilic fibers forming the fibrous web 18. Therefore, the immobilization of the superabsorbent polymer 16 becomes stronger and the gel blocking thereof is further suppressed.
Here, the superabsorbent polymer 16 is mainly adhered to hydrophilic fibers, but other fibers constituting the absorbent sheet,
For example, there is no problem even if it is adhered to the hot-melt fiber. Also, not all of the particles need be adhered to the fiber. Based on the total amount of the superabsorbent polymer 16,
50% by weight or more is preferably adhered to the fiber,
In particular, 70% by weight or more is preferably adhered to the fiber. The method of adhering the superabsorbent polymer 16 to the fibers will be described later.

When a particle agglomerate type superabsorbent polymer in which spherical particles are made into primary particles and agglomerated into secondary particles is used as the above-mentioned superabsorbent polymer, all the primary particles are fibers. If the secondary particles partially adhere to the fiber, the superabsorbent polymer will be fixed to the fiber.

Preferably, the above superabsorbent polymer 16
Are not dispersed in the absorbent sheet 10 in layers, but are dispersed in three dimensions, as shown in FIG. Therefore, the superabsorbent polymer can be dispersed in a large amount. That is, the upper limit of the spray basis weight of the superabsorbent polymer in the conventional absorbent sheet in which the superabsorbent polymer 16 is dispersed in a layered form (that is, two-dimensional form) is generally about 50 to 50.
100 g / m ² while the above-mentioned absorbent sheet 1
At 0, the superabsorbent polymer 16 can be dispersed three-dimensionally.
The upper limit of the spray basis weight can be about 200 to 300 g / m ^2, and the spray basis weight of the superabsorbent polymer 16 can be increased to about 3 times that of the conventional absorbent sheet. Therefore, the absorbent sheet 10 dramatically increases the amount of body fluid absorbed as compared with 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 exhibited. That is, even when the same amount of superabsorbent polymer as that of the conventional absorbent sheet is used, the absorbent performance can be further improved and the absorbent sheet can be made extremely thin. In addition, since the spray basis weight can be increased, it can be suitably used as an absorbent layer for a paper diaper or the like which requires a large absorbent capacity.

The superb absorbent polymer has a spray basis weight of 5 to 300 g / m ² , and preferably 10 to 250 g / m ² . In addition, when it is used for applications that do not absorb a large amount of body fluid, in order to make the absorbent sheet extremely thin,
It is preferably ²⁰ to 70 g / m ² . If the spray basis weight is less than 5 g / m ² , the water absorption capacity is insufficient and sufficient function cannot be exhibited. On the other hand, when the spray basis weight is more than 300 g / m ² , the adhesive force between the fiber web and the fiber assembly is lowered, and the superabsorbent polymer is likely to fall off. Therefore, it is preferably within the above range.

The superabsorbent polymer 16 is preferably one that can absorb and retain 20 times or more body fluid of its own weight and can gel. The shape is not particularly limited, and it is spherical, lumpy, grape-like, powdery or fibrous, and preferably has a size of 1
It is in the form of particles of ˜1000 μm (more preferably 10 to 500 μm). Examples of such superabsorbent polymers include starch, cross-linked carboxymethyl cellulose, polymers or copolymers of acrylic acid or alkali metal salts of acrylic acid, polyacrylic acid and its salts, and polyacrylate graft weight. You can list coalescence.
As the polyacrylic acid salt, sodium salt can be preferably used. In addition, acrylic acid is added to maleic acid, itaconic acid, acrylamide, 2-acrylamide-2-
A copolymer obtained by copolymerizing a comonomer such as methyl propane sulfonic acid, 2- (meth) acryloylethane sulfonic acid, 2-hydroxyethyl (meth) acrylate or styrene sulfonic acid within a range not deteriorating the performance of the superabsorbent polymer is also available. It can be preferably used.

Next, the fiber assembly 15 having the absorbent surface 12 of the absorbent sheet 10 will be described. Here, the “absorption surface” refers to a surface that first absorbs body fluid when the absorbent sheet 10 absorbs body fluid. That is, in a preferred embodiment of the absorbent sheet 10, body fluid is mainly absorbed from the fiber assembly 15 side.

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

The above-mentioned fiber assembly is obtained by mechanical entanglement, physical entanglement, thermal bonding, etc. of fibers, and for example, paper or non-woven fabric can be used.
As the paper, it is possible to use paper obtained by wet papermaking, crepe-processed paper, or the like. On the other hand, as the non-woven fabric, various non-woven fabrics such as a card method non-woven fabric, a spunbonded non-woven fabric, and a spunlace non-woven fabric which are mainly composed of synthetic cellulose fibers such as rayon and cupra and natural cellulose fibers such as cotton can be used.

The fiber assembly preferably contains hydrophilic fibers. As such a hydrophilic fiber, the same as that used in the above-mentioned fiber web can be used. The hydrophilic fiber is contained in an amount of preferably 30 parts by weight or more, and more preferably 50 to 99 parts by weight, based on 100 parts by weight of the fiber assembly.

It is preferable that the fiber assembly is imparted with a wet strength like the fiber web. By imparting the wet strength, the form can be stably maintained even when the absorbent sheet is wet.
Regarding the wet strength of the fiber assembly, the wet strength measured according to JIS-P-8113 is preferably 50 g or more, and more preferably 100 g or more. In order to impart wet strength to the fiber assembly, as in the case of the fiber web, the heat-meltable adhesive fiber or the paper reinforcing agent is blended. It is also preferable to further 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, and more preferably 0.02 to 20 parts by weight, based on 100 parts by weight of the fiber aggregate.

The above-mentioned fiber assembly is particularly preferably formed by the same composition as the fibers and components forming the above-mentioned fiber web.

It is also preferable that the fiber assembly is made of a non-woven fabric, and 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 the body fluid permeable surface layer, it is possible to use a synthetic fiber nonwoven fabric as the fiber assembly. ,
It is possible to obtain a bodily fluid-absorbent article with a further improved feeling of salat.

The fiber aggregate has a basis weight of 10 to 20.
It is preferably 0 g / m ² , and 10 to 100 g / m
More preferably, it is ² . The basis weight is 10 g / m ²
If it does not satisfy the above condition, the superabsorbent polymer may project from the fiber assembly and fall off during swelling of the superabsorbent polymer. On the other hand, if the basis weight is more than 200 g / m ² , the density of the fiber assembly may be too high and the absorbent sheet may be too hard.

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

In the absorbent sheet, the fiber aggregate has a basis weight of 10 to 200 g / m ² , and the superabsorbent polymer has a spray basis weight of 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 21 to 500 g / m ² , and is 30
To 300 g / m ² , more preferably 50 to 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, and a fiber density of 0.1 g / cm ³ or more.
Is more preferably 0.4 g / cm ³ and 0.1
More preferably, it is about 0.2 g / cm ³ . By setting the fiber density in such a range, gel blocking of the superabsorbent polymer can be more effectively prevented. The 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 absorbent sheet is composed of a fibrous structure formed of bulky hydrophilic fibers and heat-meltable adhesive fibers or a paper-strengthening agent, and superabsorbent polymer particles, The superabsorbent polymer particles do not exist on the absorbent surface where the absorbent sheet absorbs body fluid, and are dispersed and fixed in the fibrous structure, and the thickness of the absorbent sheet is 0.3 to 1.5 mm. The absorbent base sheet has a spray basis weight of 20 to 70 g / m ² of the super absorbent polymer. Such an absorbent sheet is extremely thin. Moreover, if a large amount of body fluid is not absorbed, there is almost no increase in thickness even after absorption of body fluid. Therefore, when such an absorbent sheet is used, for example, as the absorbent layer of a sanitary napkin, a comfortable fit can be obtained even after absorbing menstrual blood.

When the absorbent sheet is used as the absorbent layer of a sanitary napkin, the basis weight of the superabsorbent polymer dispersed in the absorbent sheet is preferably 10 to 100 g /
m ² , more preferably 20 to 70 g / m ² , the basis weight of the fiber assembly is preferably 10 to 80 g / m ² , and more preferably 15 to 50 g / m ² , and the basis weight of the fiber web is preferably Is 10 to 80 g / m ² , more preferably 15
˜50 g / m ² , and the thickness of the absorbent sheet is preferably 0.3 to 1.5 mm. On the other hand, when the absorbent sheet is used as an absorbent layer for holding multiple liquids such as disposable diapers, the basis weight of the superabsorbent polymer dispersed 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 assembly 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
It is 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 absorption efficiency is good because the super-absorbent polymer is dispersed and adhered to the fibers. 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 , and a thickness of 0.5 to
It is preferably 1.2 mm. Thus, the absorbent sheet is extremely thin. Moreover, the increase in thickness is small even after absorbing body fluid. The reason for this is that when absorbing body fluids, the superabsorbent polymer becomes larger and the interfiber 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 the elasticity of the fiber and the thickness of the superabsorbent polymer do not increase due to the opening of the fiber as in No. 1,050.

The thickness of the absorbent sheet is the thickness after the fiber assembly 15 and the fiber web 18 are integrated, and this thickness is smaller than before the integration. This integration largely contributes to the hot-melt adhesive fiber or the paper-strengthening agent blended in the absorbent sheet. Further, in the absorbent sheet, as described above, the superabsorbent polymer is dispersed and adhered to the fibers, so that the absorbent sheet has good absorption efficiency, and thus it is possible to reduce the thickness. In particular, the use of bulky cellulose fibers is preferable because the dispersed state of the superabsorbent polymer is further improved. Since the super absorbent polymer is in close contact with the fibers and the fiber assembly 15 and the fiber web 18, the body fluid can be smoothly transferred to the super absorbent polymer. In addition, since the fiber assembly 15 and the fiber web 18 are bonded by the heat-melting adhesive fiber or the paper-strengthening agent, the structure is kept stable even when wet, and liquid transfer to the superabsorbent polymer is achieved. And excellent fixability of super absorbent polymer. Further, the thickness of the absorbent sheet is, as described above, US Pat. No. 4,605,402 and US Pat.
Unlike No. 021,050, etc., it does not easily increase after wetting.
In particular, when bulky cellulose fibers are used as hydrophilic fibers, the density becomes low and spaces are formed by the fibers, so that the superabsorbent polymer has excellent dispersibility and liquid transfer properties, and is particularly useful for absorbing body fluids with high viscosity. Excel. Further, since the space is secured by the fibers, the liquid absorbency after wetting is excellent without the thickness increasing significantly. As described above, in the absorbent sheet, the fixing property and the absorption efficiency of the superabsorbent polymer are improved, so that the absorbent sheet can be made thin. In addition, the integration of the fiber assembly 15 and the fiber web 18 into a sheet, and the use of a heat-melting adhesive fiber or a paper-strengthening agent that contributes to the stabilization of the structure when wet is one of the factors for reducing the thickness. Is one.

Next, a preferred method for producing the absorbent sheet will be described with reference to the drawings. Here, FIG. 11 is a schematic view showing an apparatus preferably used for manufacturing the absorbent sheet. This method is a method for producing an absorbent sheet containing at least a hydrophilic fiber and a heat-meltable adhesive fiber or a paper-strengthening agent, and a superabsorbent polymer, wherein A fiber assembly containing a hydrophilic fiber and a heat-melting adhesive fiber or a paper-strengthening agent, on which a superabsorbent polymer is sprinkled on a wet fibrous web formed by wet papermaking with an aqueous slurry containing an agent. Are stacked, and these are dried and integrated. According to this method, the superabsorbent polymer does not exist on the absorbent surface where the absorbent sheet absorbs body fluid,
Moreover, it is possible to easily disperse and arrange the absorbent sheet inside. Further, the super absorbent polymer can be easily adhered and fixed to the hydrophilic fibers constituting the absorbent sheet. Furthermore, it becomes easy to make the thickness of the absorbent sheet as thin as 0.3 to 1.5 mm.

The above method will be described in detail. First, the fiber web containing the hydrophilic fibers is formed. The method for forming the fibrous web is not particularly limited, and for example, a dry papermaking method can be used, but a wet papermaking method is preferably used. This is because, as will be described later, when the superabsorbent polymer is applied to the fiber web, the fiber web must be in a wet state and the degree of freedom of the fibers must be extremely high. This is because when the web is formed, it immediately realizes the wet state, and therefore it is possible to save the trouble of making the wet state in another step. Further, in the fiber web obtained by the wet papermaking method, the fibers are not sufficiently bonded to each other before being dried. It also has the advantage that it is easy to be three-dimensionally embedded in the space formed in, and a large amount of superabsorbent polymer can be dispersed.

When the above fibrous web is subjected to wet papermaking,
The fibers and components forming the fibrous web, preferably the hydrophilic fibers and the heat-melting adhesive fibers or the paper-strengthening agent, etc., are dispersed in water to a predetermined concentration to form a slurry. . The concentration of the hydrophilic fiber, the heat-meltable adhesive fiber, the paper-strengthening agent, and the like in the slurry may be the concentration in general wet papermaking. Further, the relative blending ratio between the hydrophilic fiber and the heat-melting adhesive fiber, the paper-strength reinforcing agent, or the like is such that the blending ratio thereof in the fiber web obtained by wet papermaking falls within the above-mentioned range. You can do this.

On the fibrous web thus obtained, the superabsorbent polymer is sprinkled in the wet state. The wet state of the fibrous web is preferably about 20 to 500 parts by weight of water based on 100 parts by weight of the dry fibrous web, and more preferably 50 to 300 parts by weight of water.
If the amount of water is less than 20 parts by weight, the superabsorbent polymer that has been sprayed absorbs water and wets it, making it impossible to obtain tackiness. If the amount exceeds 500 parts by weight, the superabsorbent polymer may have excessive water absorption, resulting in poor drying in the drying step described later.

The superabsorbent polymer is sprinkled on a wet fibrous web. As a result, the superabsorbent polymer absorbs water and becomes tacky, is embedded in the fibers constituting the fibrous web, and is adhered and fixed to the fibers by subsequent drying. Further, since the fibers forming the wet web have a degree of freedom because they are not yet bonded to each other, the superabsorbent polymer can be dispersed three-dimensionally. Therefore, as compared with the conventional absorbent sheet, a larger amount of superabsorbent polymer can be stably fixed. When the superabsorbent polymer is sprayed, the superabsorbent polymer may be evenly sprayed on the entire surface of the wet fibrous web, or if necessary, the wet fibrous web may be spaced in the longitudinal direction. It is also possible to disperse the fibers in a striped manner or intermittently disperse the wetted fibrous web in a shot form in the longitudinal direction.

Then, the fiber assembly is superposed on the surface of the fiber web on which the superabsorbent polymer is sprayed. At this point, the fibers in the fibrous web still have a degree of freedom, so that the superabsorbent polymer is further embedded in the fibrous web and the fibers in the fibrous web and the fibrous aggregate. Easily intertwined with the fibers inside.

Subsequently, by drying the superposed body of the fiber web and the fiber aggregate, the fibers are entangled with each other, and further, the action of hydrogen bonding or heat fusion is added, so that the fiber web and the fiber are combined. The super absorbent polymer which is integrated with the aggregate and adheres to the fibers is dried and adhered to obtain the absorbent sheet. The drying temperature depends on the type of fibers used, but is preferably in the range of 100 to 180 ° C., more preferably 105.
It is in the range of to 150 ° C. By drying and integrating, the fiber web and the fiber aggregate are integrated, and the fibers constituting the fiber web are bonded to 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 by an in-line single 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 (20 to 20 parts of water based on 100 parts by weight of the dried fibrous web). (Dehydrated to the extent of including 500 parts by weight), the superabsorbent polymer 16 is sprinkled on the fiber web 18 immediately before the press part 44, and the fiber assembly 15 is superposed on the superposed polymer 16, and then the conveyer 45 is applied to the dryer 46. Guide them and dry them with a dryer 46 to integrate them. By this method,
The absorbent sheet 10 can be manufactured easily at high speed.

As the wet paper machine, an ordinary paper machine can be used, and examples of such a paper machine include a fourdrinier paper machine and a round net paper machine. As for the steps other than those described above, the steps in the ordinary papermaking method can be appropriately used.

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

[0115] In the absorbent sheet, the superabsorbent polymer is less likely to fall off, and tearing of the sheet due to swelling of the superabsorbent polymer can be prevented. Therefore, the absorbent sheet can be used alone as a body fluid absorbent article. A deodorant, a bactericide, or the like may be added to the absorbent sheet at the time of manufacturing 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 Examples and Comparative Examples, but it goes without saying that the present invention is not limited to these Examples. In the following description, “part” means “part by weight” unless otherwise specified.

[Production Example 1] Production of absorbent sheet Fiber roughness 0.18 mg / m, fiber cross-section roundness 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 strength agent [polyamide epichlorohydrin resin, trade name; Kaimen WS-570, company name; Japan PMC Co., Ltd.] was dispersed and mixed in a part with water as a resin component.
^A fibrous web was formed to be ² . Then, the fiber web is dried with a suction box to obtain a dry fiber web 1
The fibrous web was dehydrated to a water content of 200 parts based on 00 parts. Then, immediately before the pressing part, the superabsorbent polymer [Kao Corporation
Polymer Q (trade name)] was sprayed substantially uniformly at a basis weight of 50 g / m ² .

Absorbent paper (paper basis weight of 40 g / m 2) having a composition similar to that of the above-mentioned fiber web as a fiber aggregate on the surface of the above-mentioned fiber web on which the above-mentioned superabsorbent polymer has been sprayed. ² ) are superposed, and the superposed body of the fiber web and the absorbent paper is introduced into a dryer, and 1
By drying and integrating at a temperature of 30 ° C., a single absorbent sheet having a superabsorbent 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.) Was used.
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 the water present in the chemical pulp.
Approximately 1 g of the above chemical pulp within ± 0.1 mg accuracy
Accurately measure. Next, in order not to damage the chemical pulp, the chemical pulp was completely disintegrated in 150 ml of water with a mixer attached to the fiber roughness meter, and this was 5,000 ml.
It was diluted with water until it became, and 50 ml was accurately measured from the obtained diluted solution, which was used as a fiber roughness measuring solution, and 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 above chemical pulp is sliced perpendicularly to the cross section so that the area does not change, and a cross section photograph is taken with an electron microscope. [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 formula shown below. The roundness was an average value obtained by measuring 100 points on the fiber cross section of the above chemical pulp.

[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 of [ITROS RAYONIER INC.'S "POROSA
NIER-J "(trade name)], and polyvinyl alcohol fiber having a thickness of 1 denier and a length of 3 mm (heat-melting adhesive fiber, Fibribond (trade name) manufactured by Sansho Co., Ltd., hereinafter" PVA fiber ") 5 parts were dispersed and mixed in water to a predetermined concentration, and then the dispersion / mixed liquid was formed into a fibrous web in a forming part of a wet paper machine so that the dry basis weight was 40 g / m ² . Then, the fiber web was dehydrated by a suction box until the water 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 fibrous web after dehydration substantially uniformly at a basis weight of 50 g / m ² .

Absorbent paper (basis weight: 40 g / m 2) having a composition similar to that of the above-mentioned fiber web as a fiber aggregate, on the surface of the above-mentioned fiber web on which the above-mentioned superabsorbent polymer has been sprayed. ² ) are superposed, and the superposed body of the fiber web and the absorbent paper is introduced into a dryer, and 1
By drying and integrating at a temperature of 30 ° C., a single absorbent sheet having a superabsorbent polymer fixed therein was obtained. This absorbent sheet is referred to as absorbent sheet B.

[Production Example 3]Absorbent sheet manufacturing Fiber roughness 0.32 mg / m, roundness of fiber cross section is 0.30
Cross-linked pulp of [High Bul made by Weyerhauser Paper
k Additive HBA-S "(trade name)] 70 parts and fiber
Conifer with a 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
Strengthening paper strength against 100 parts by dry weight of mixed pulp
Agent [polyamide epichlorohydrin resin, trade name; kai
Men WS-570, company name; Japan PMC Co., Ltd.]
After dispersing and mixing 1 part of the ingredients in water to a predetermined concentration,
Dry this dispersion mixture in the forming part of a wet paper machine.
Dry basis weight is 40g / m²Forming a fibrous web so that
Was. Then, the fiber web is placed in a suction box.
To 100 parts moisture content based on 100 parts dry fiber web
The fiber web was dewatered until Then press par
Immediately before drying, it has high absorbency on the wet fibrous web after dehydration
Disperse polymer [Polymer Q (trade name) of Kao Corporation]
Basis weight 50g / m ²It was sprayed almost evenly.

Absorbent paper (basis weight: 40 g / m 2) having a composition similar to that of the above-mentioned fiber web, as a fiber aggregate, on the surface of the above-mentioned fiber web on which the above-mentioned superabsorbent polymer has been sprayed. ² ) are superposed, and the superposed body of the fiber web and the absorbent paper is introduced into a dryer, and 1
By drying and integrating at a temperature of 30 ° C., a single absorbent sheet having a superabsorbent 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 cross section 0.30
Cross-linked pulp of [High Bul made by Weyerhauser Paper
k Additive HBA-S ”(trade name)] and 5 parts of the PVA fiber are dispersed and mixed in water to a predetermined concentration, and the dispersion mixture is dried in a forming part of a wet paper machine to give a dry basis weight of 40 g. A fibrous web was formed to have a thickness of / m ² . Then, the fiber web was dehydrated by 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 fibrous web after dehydration substantially uniformly at a basis weight of 50 g / m ² .

Absorbent paper (paper basis weight of 40 g / m 2) having a composition similar to that of the above-mentioned fiber web as a fiber aggregate on the surface of the above-mentioned fiber web on which the above-mentioned super absorbent polymer has been sprayed. ² ) are superposed, and the superposed body of the fiber web and the absorbent paper is introduced into a dryer, and 1
By drying and integrating at a temperature of 30 ° C., a single absorbent sheet having a superabsorbent polymer fixed therein was obtained. This absorbent sheet is referred to as absorbent sheet D.

[Production Example 5]Absorbent sheet manufacturing Fiber roughness 0.32 mg / m, roundness of fiber cross section is 0.30
Cross-linked pulp of [High Bul made by Weyerhauser Paper
k Additive HBA-S "(trade name)] 90 parts and thick
1.1 denier, 5 mm long low melting point polyester adhesive
10 fibers [TM-07N (trade name) manufactured by Teijin Ltd.]
Parts in water and mixed to a prescribed concentration, then
The mixed liquor has a dry basis weight of 4 in the forming part of a wet paper machine.
0 g / m ²Was formed into a fibrous web. Next
Then, dry the fiber web with a suction box.
Based on 100 parts of web, until the water content becomes 100 parts,
The fiber web was dewatered. Then, just before the press part,
Superabsorbent polymer on the wet fibrous web after dehydration
[Kao Corporation's polymer Q (trade name)] is applied and the basis weight is 50
g / m²It was sprayed almost evenly.

Of the above fiber web, the surface on which the super absorbent polymer has been sprinkled is subjected to a hydrophilization treatment to obtain a polyethylene / polypropylene composite fiber having a thickness of 2.2 denier and a length of 38 mm (manufactured by Chisso Corporation). ], A dry heat-bonded nonwoven fabric manufactured by a card machine (basis weight: 40 g / m ² )
And the superposed body of the fibrous web and the non-woven fabric is introduced into a dryer and dried at a temperature of 130 ° C.
By integrating, a single absorbent sheet having a superabsorbent 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 the fiber cross section of 0.32 [Skeena Cellulose Co.
SKEENA PRIME (trade name) manufactured by K.K. was used in advance to make an absorbent sheet using an absorbent paper having a basis weight of 40 g / m ² . That is, water is sprinkled on the absorbent paper until 100 parts of the absorbent paper (dry) reaches 200 parts. Then, a superabsorbent polymer [Polymer Q (trade name) of Kao Corporation] was sprayed on the wet absorbent paper almost uniformly at a spray basis weight of 50 g / m ² .

Of the absorbent paper, an absorbent paper having a basis weight of 40 g / m ² having the same composition as the absorbent paper was superposed on the surface of the absorbent paper on which the superabsorbent polymer was sprayed. The superposed bodies were pressure-bonded and integrated, and then 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 has been dispersed is not in the form of a wet fiber web, but the pulp fibers are strongly bound to each other, and the absorbent paper between the two absorbent papers is high. 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 On the same absorbent paper as in Comparative Production Example 1, the absorbent paper (dry) was used.
Spray 100 parts of water to 10 parts. Then, a superabsorbent polymer [Polymer Q (trade name) of Kao Corporation] is spread on the above-mentioned absorbent paper, and the basis weight is 50 g / m 2.
Sprayed almost evenly with ² .

Among the absorbent papers, an absorbent paper having a basis weight of 40 g / m ² having the same composition as the absorbent paper was superposed on the surface on which the superabsorbent polymer was sprayed, Emboss crimping the overlapped body through a lattice embossing roll that is divided into 5 mm sections in the vertical and horizontal directions.
After being integrated, it is dried with a dryer 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 has been dispersed is not in the form of a wet fiber web, but the pulp fibers are strongly bound to each other, and the absorbent paper between the two absorbent papers is high. The absorbent polymer is pressure-bonded by embossing. This absorbent sheet is referred to as an absorbent sheet G.

Comparative Production Example 3 Production of Absorbent Sheet On the same absorbent paper as in Comparative Production Example 1, an adhesive [Movinyl 710 (trade name) manufactured by Hoechst Synthetic Co., Ltd.] was prepared with a basis weight of 20.
g / m ² and then a super absorbent polymer [Polymer Q (trade name) of Kao Co., Ltd.] is sprinkled on it.
It was sprayed almost uniformly at g / m ² .

Of the absorbent paper, an absorbent paper having a basis weight of 40 g / m ² having the same composition as the absorbent paper was superposed on the surface of the absorbent paper on which the superabsorbent polymer was sprayed. The superposed bodies were pressure-bonded and integrated, and then 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 has been dispersed is not in the form of a wet fiber web, but the pulp fibers are strongly bound to each other, and the absorbent paper between the two absorbent papers is high. The absorbent polymer is fixed in layers by an adhesive. This absorbent sheet is referred to as an absorbent sheet H.

Comparative Production Example 4 Production of Absorbent Sheet A dry absorbent sheet containing synthetic pulp and a superabsorbent polymer was produced. That is, polyethylene synthetic pulp 25
Sheet and a pulp sheet consisting of 75 parts of chemical pulp [softwood pulp, manufactured by Hercules Co., Ltd.] are defibrated with a hammer mill to form a dry absorbent sheet having a basis weight of 80 g / m ^{2 and} a superabsorbent polymer. [AQUALIC CAW-4 (trade name) manufactured by Nippon Shokubai Co., Ltd.] was mixed in the raw material so as to be 50 g / m ² , and then polyethylene synthetic pulp was fused and integrated by hot air treatment. . The dry absorbent sheet has a super absorbent polymer 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 formed by the air laid method [softwood pulp, manufactured by Hapix Co., Ltd.] was used, and a highly absorbent polymer [Nippon Catalyst Co., Ltd.] was used. Aqualic CAW-4 (trade name) manufactured by K.K. Co., Ltd. was sprayed so that the basis weight was 50 g / m ² , and then an absorbent sheet was produced in which pulp was fixed with a chemical binder. 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 compounding compositions and production methods 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 into an appropriate size with a load area of 10 cm ² (disc having a radius of 17.8 mm), and the thickness was measured with a thickness meter. It was measured. The average value of 10 points in total was taken as the thickness.

<Detachment test of superabsorbent polymer> 70 × 2
After measuring the weight of the absorbent sheet cut out to 00 mm,
This is put in a plastic bag with a chuck having a length of 280 mm and a width of 200 mm, and in this state, shaking is performed by shaking 50 times by hand. After the test, the weight change of the absorbent sheet was measured, and the colored water dyed with Blue No. 1 (0.3
(100 g of water / 100 ml of water) is added to a plastic bag to swell the superabsorbent polymer, and the degree of dropout is visually determined. ○: Almost no dropout of the superabsorbent polymer was observed. Δ: Some dropout of the superabsorbent polymer is observed. X: The dropout of the superabsorbent polymer is considerably observed. The measurement was performed 10 times, and the average value was used as the amount of dropout.

<Sheet strength of absorbent sheet when wet> 2
Hold the absorbent sheet cut out to a size of 00 mm x 200 mm in your hand, and put on the desk colored water dyed with Blue No. 1 (0.3 g / water 1
(00 ml) was dripped, and the colored water was wiped off with an absorbent sheet held in the hand. A wiping test was repeated three times in total (a total of 30 g of the absorbent sheet was absorbed), and a tearing of the sheet on the surface of the absorbent sheet and a dropout test of the superabsorbent polymer were performed. ○: The surface of the absorbent sheet is not broken, and the superabsorbent polymer does not fall off. Δ: The surface of the absorbent sheet is slightly broken, but the superabsorbent polymer does not fall off. X: The surface of the absorbent sheet was torn and the superabsorbent polymer was dropped off.

<Saturated absorption amount> A 5 cm square absorbent sheet was placed in a bag made of non-woven fabric, and the entire bag was immersed in ion-exchanged water for 10 minutes. After removing the bag from the ion-exchanged water, it was hung in the air for 1 hour to remove the adhering water, and then the weight was measured, and the increase in the weight per 1 g of the absorbent sheet was measured as the saturated absorption amount (g / g). ).

<Absorption rate> As shown in FIG.
In the center of the corner absorbent sheet 10, a 10 cm square transparent acrylic plate 20 and a weight 22 with a hole of 1 cm diameter 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 absorption rate was measured twice, but the second injection (resorption rate) was performed 1 minute after the first measurement.

<Measurement of Liquid Return> After measuring the absorption rate, 10
As shown in FIG. 13, 1 minute is left on the absorbent sheet.
10 sheets of 5 cm square filter paper 24 (Toyo Filter Paper TYPE2) are stacked, and 15 cm square acrylic plate 26 and weight 22 are placed on top of it.
Apply a load of 0 g / cm ² for 1 minute, then filter paper 2
4 was taken out, and the weight of physiological saline absorbed by the filter paper 24 was used as the liquid return amount.

[0149]

[Table 3]

Example 1 A sanitary napkin having the constitution 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 was used, and a fluff pulp having a length of 175 mm and a width of 73 mm adjusted to have a thickness of 4.5 mm on a basis weight of 300 g / m ^2. 2a was laminated. The side surface and the upper surface of the combination of the absorbent sheet A and the fluff pulp have a basis weight of 18 g / m ² and a width of 130 m.
Wet absorbent paper 2b made of wood pulp with a length of m and a length of 175 mm
And the absorption layer 2 was produced.

Waterproof paper as the leakproof layer 3 (paper made by laminating polyethylene on wet absorbent paper, length 205 mm, width 95)
mm) was used to cover the side surface and the bottom surface of the obtained absorbent layer 2 with the waterproof paper. All the surfaces of the combination of the absorbent layer 2 and the poly-laminated paper are covered with a surface layer 1 (length 205 mm, width 172 mm) capable of absorbing body fluid described below and the hot melt adhesive used as the fixative 6 The member was fixed. Further, on the side opposite to the surface layer 1, the basis weight is 30 g / m ² , the width is 20 mm, and the length is 115 mm.
Two hot melt adhesives of No. 2 were applied as the adhesive portion 4.
In this way, a sanitary napkin (invention product 1) having the structure shown in FIG. 1 was obtained.

As the surface layer 1, a polyethylene perforated film was used. This surface layer 1 has a basis weight of 30 g.
/ M ² polyethylene film is perforated and one perforation diameter is 0.5 mm and the perforation area ratio is 20
% Perforated.

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 constitution shown in FIG. 3 was manufactured. That is, as the absorbent sheet 10, an absorbent sheet B having a length of 175 mm and a width of 145 mm was used, and was folded and compressed into a C shape so that both side edges thereof face each other substantially at the center of the absorbent body to have a width of 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] FIG. 3 is similar to Example 3 except that absorbent sheets C, D and E are used instead of the absorbent sheet B used in Example 3. Sanitary napkins having the constitutions (inventive products 4, 5, and 6 respectively) were obtained.

Comparative Example 1 A sanitary napkin having the constitution shown in FIG. 7 was manufactured. That is, the basis weight is 300 g / m ² and the thickness is 4.
After spraying a small amount of water on the fluff pulp 2a having a length of 175 mm and a width of 73 mm adjusted to 5 mm, the superabsorbent polymer 2e [AQUALIC CAW-manufactured by Nippon Shokubai Co., Ltd.
4 (brand name)] about 60 mm wide and 175 mm long, about 0.53 g is sprayed almost uniformly and the basis weight is 50 g.
/ M ² . On top of this, a basis weight of 18 g / m ² and a length of 17
Wet absorbent paper 2 made of wood pulp with a width of 5 mm and a width of 73 mm 2
b, and all sides of these combinations have a basis weight of 18 g
The absorbent layer 2 was formed by covering with a wet absorbent paper 2c made of wood pulp having a length of 175 mm / m ² and a width of 130 mm to form an integrated absorbent layer 2. Thereafter, in the same manner as in Example 1, a sanitary napkin 100 (Comparative Product 1) having the configuration shown in FIG. 7 was produced.

[Comparative Examples 2 to 4] FIG. 1 is shown in the same manner as in Example 1 except that absorbent sheets F, G and H are used instead of the absorbent sheet A used in Example 1. The sanitary napkins having the constitutions (comparative products 2, 3 and 4 respectively) were obtained.

[Comparative Examples 5 to 7] FIG. 3 shows the same procedure as in Example 3 except that absorbent sheets F, I and J were used instead of the absorbent sheet B used in Example 3. The sanitary napkins having the constitutions (comparative products 5, 6 and 7 respectively) were obtained.

In order to evaluate the polymer-immobilizing ability and the absorbing ability of 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, a polymer drop test was conducted by the following method. The product thickness, absorption time, dynamic liquid return amount, and leak test were performed. The respective results are shown in Table 4.

<Detachment Test of Super Absorbent Polymer> Example 1
~ 6 and the weight of the sanitary napkins of Comparative Examples 1 to 7 are put in a plastic bag with a chuck having a length of 280 mm and a width of 200 mm, and in this state, vibration is applied by shaking by hand 50 times. After the test, the weight change of the sanitary napkin was measured, and the colored water dyed with Blue No. 1 (0.3 g / 100 ml of water) was used so that the superabsorbent polymer that had fallen into the plastic bag could be observed with the naked eye. Into a plastic bag, swell the superabsorbent polymer, and visually determine the degree of shedding. ○: Almost no dropout of the superabsorbent polymer was observed. Δ: Some dropout of the superabsorbent polymer is observed. X: The dropout of the superabsorbent polymer is considerably observed. The measurement is performed 10 times, and the average value is used as the amount of dropout.

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

<Absorption time (5 g), re-absorption 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.
Instead of 0, the sanitary napkins obtained in Examples 1 to 6 and Comparative Examples 1 to 7 were placed horizontally, an acrylic plate 20 with an inlet having a diameter of 1 cm 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 defibrinated horse blood (manufactured by Japan Biotest Institute Co., Ltd.) is injected from the injection port, and the absorption time (second) until the defibrinated horse blood is completely absorbed is determined. After the defibrinated horse blood was completely absorbed, it was left as it was for 20 minutes, 5 g of defibrinated horse blood was injected again, the reabsorption time (10 g) was determined, and it was left for 20 minutes in the same manner. 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 were placed on the upper surface (skin contact surface side) of the sanitary napkin,
The shorts with the sanitary napkin 80 as shown in FIG. 16 were put on the movable female waist model 90 shown in FIG. 15, and then walked for 1 minute at a walking speed of 100 seconds / minute (50 m / minute). After walking, the sanitary napkin 80 and 10 sheets of absorbent paper were taken out, and the weight of defibrinated horse blood absorbed in the absorbent paper was determined as the liquid return amount (g). The measurement was carried out at 5 points respectively, 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)> Examples 1 to 1
6 and the sanitary napkin 80 obtained in Comparative Examples 1 to 7,
As shown in FIG. 16, after putting on the movable female waist model 90 and putting on the shorts, 100 steps / min (50 m /
The walking speed was 10 minutes. Then, while walking, 5 g of defibrinated horse blood was injected into the sanitary napkin 80 through the tube 91, and then walking at the same speed for 20 minutes (5 g absorption), and further defibrinated horse blood 5
After injecting g, walking at the same speed for 20 minutes (1
(0 g absorption), and the number of leaks was counted out of 10 samples at each time point.

[0164]

[Table 4]

As is clear from the results shown in Tables 3 and 4, the body fluid absorbent article of the present invention uses an absorbent sheet in which the fiber web and the fiber assembly are integrated and the superabsorbent polymer is contained therein. Compared with a body fluid absorbent article that has a conventional absorbent sheet (an absorbent sheet obtained by water spraying, embossing integration or integration with an adhesive), it has excellent immobilization properties for superabsorbent polymers and is extremely thin. It can be seen that even when an absorbent sheet of 2 to 3 mm is used, it has excellent absorption characteristics such as the absorption rate and the amount of liquid returned.

In the comparison between the bodily fluid absorbent articles using fluff pulp and having a thickness of about 6 mm (comparison between Examples 1-2 and Comparative Examples 1 and 2-4), since a large amount of fluff pulp was used, Although the degree of improvement in absorbency is small, Examples 1-2
In the bodily fluid absorbent article of, the dropout of the superabsorbent polymer does not occur,
It can be seen that the fixability of the superabsorbent polymer is very good. 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 preferred example of use of the body fluid absorbent article of the present invention, the body fluid absorbent body using the above-mentioned absorbent sheet has a thickness of about 2 to 3 mm, which is about half or less the thickness of the conventional body fluid absorbent article. Examples include sex articles. Regarding the fact that the thickness of the body fluid absorbent article of the present invention can be made extremely thin, Examples 3 to
It is clear from the comparison between No. 5 and Comparative Examples 5 to 7.

[0168]

EFFECTS OF THE INVENTION According to the present invention, it is possible to provide a body fluid absorbent article which is capable of immobilizing a large amount of superabsorbent polymer despite being extremely thin. In particular, using an absorbent sheet formed from bulky cellulose fibers,
When configuring the body fluid absorbent article of the present invention, not only the fixability of the superabsorbent polymer, the absorption rate of body fluid becomes high,
It is possible to provide a bodily fluid-absorbent article which has a small amount of returned liquid, has a small number of leaks, and is extremely thin and has high absorption performance. Further, since the absorbent sheet has a structure in which the fiber web and the fiber assembly are integrated and the superabsorbent polymer is held therein, the body fluid absorbent according to the present invention including the absorbent sheet is provided. Even when the absorbent article is worn and subjected to vigorous exercise, the superabsorbent polymer does not separate from the absorbent sheet and the absorbent performance does not deteriorate. Furthermore,
Since the above-mentioned absorbent sheet contains a super-absorbent polymer in advance, the facility for spraying the super-absorbent polymer in the final processing process for producing the body fluid-absorbent article of the present invention is not required, and the absorbent sheet is simple. We can provide processing equipment. Moreover, when the absorbent layer is composed of only the absorbent sheet, it is sufficient to cut only one absorbent sheet, which is a very simple and high-speed processing facility.

[Brief description of drawings]

FIG. 1 is a schematic view 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 view 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 view 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 diagram showing a preferred method for producing an absorbent sheet.

FIG. 12 is a schematic diagram showing measurement of absorption rate.

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

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

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

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

[Explanation of symbols]

 1 Surface layer capable of absorbing body fluid 2 Absorbing layer capable of retaining body fluid 3 Body fluid impermeable leak preventive layer 4 Adhesive part 5 Release paper 6 Joining part 10 Absorbent sheet 12 Absorbing surface 15 Fiber assembly 16 Super absorbent polymer 18 Fiber Web 30, 31 Tissue 40 Forming part 42 Suction dewatering process 44 Press part 46 Dryer 100 Sanitary napkin

Claims (8)

[Claims] 1. A body fluid absorbent article comprising at least a body fluid-retaining absorbent layer and a body fluid-impermeable leakproof layer, wherein the absorbent layer comprises at least a hydrophilic fiber and a heat-meltable adhesive fiber or a paper reinforcing agent. And an absorbent sheet containing a superabsorbent polymer; the superabsorbent polymer does not exist on the absorbent surface where the absorbent sheet absorbs body fluid, and is dispersed and arranged inside the absorbent sheet. And is adhered and fixed to the hydrophilic fibers constituting the absorbent sheet; the basis weight of the superabsorbent polymer is 5 to 300 g /
m ² ; the absorbent sheet has a thickness of 0.3 to 1.5
A body fluid absorbent article, characterized in that it is composed of an absorbent sheet of mm. 2. The absorbent sheet is composed of a fiber assembly and a fiber web, and the fiber assembly and the fiber web are integrated, and the fiber assembly has the absorbent surface. The absorbent surface side does not contain the superabsorbent polymer, the fiber web is formed of at least the hydrophilic fiber, and the superabsorbent polymer is mainly dispersed and arranged in the fiber web. The body fluid absorbent article according to claim 1. 3. The fiber assembly 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 2. 4. The body fluid absorbent article according to claim 1, wherein the hydrophilic fibers are bulky cellulose fibers. 5. The body fluid absorbent article according to claim 4, wherein the bulky cellulose fiber has a fiber roughness of 0.3 mg / m or more. 6. The body fluid absorbent article according to claim 4, wherein the bulky cellulose fiber has a roundness of its fiber cross section of 0.5 to 1. 7. The body fluid absorbent article according to claim 4, wherein the bulky cellulose fibers are crosslinked cellulose fibers. 8. A body fluid absorbent article comprising at least a body fluid retaining absorbent layer and a body fluid impermeable leakproof layer, wherein the absorbent layer comprises bulky hydrophilic fibers and heat-meltable adhesive fibers or paper strength. An absorbent sheet comprising a fibrous structure formed from a reinforcing agent and superabsorbent polymer particles, wherein the superabsorbent polymer particles are not present on the absorbent surface where the absorbent sheet absorbs body fluids. , Dispersed and fixed in the fibrous structure, and the thickness of the absorbent sheet is 0.3 to 1.5 mm,
The basis weight of the superabsorbent polymer is 20 to 70 g / m ²
The absorbent article according to claim 1, wherein the absorbent article has no discomfort due to absorption and swelling of body fluid during use.