JP2810312B2 - Sanitary napkin - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a sanitary napkin, and more particularly, to a napkin having improved blood absorption characteristics, in particular, a liquid return property and a leak prevention property from an absorber during high excretion. The present invention relates to a thin, comfortable and highly absorbent sanitary napkin.

[0002]

2. Description of the Related Art Many sanitary napkins with improved body fluid absorbency have been proposed and many improvements have been made. And
Most of these improvements have been in increasing the absorption rate, preventing liquid return from the absorber to the surface, preventing leakage and reducing stickiness to the body.

[0003] For example, as for the material of the absorber, the body fluid is replaced with a hydrophilic absorbent paper or pulp which absorbs and retains the liquid in a physical fine space, and the body fluid is subjected to a physicochemical action, that is, It has been proposed that a body fluid is absorbed and held by using a highly absorbent polymer utilizing an ionic osmotic pressure, thereby improving absorption capacity and preventing liquid return after absorption. According to this proposal, the absorbability has been improved, and at present, an absorbent using both pulp and a superabsorbent polymer is used for most sanitary napkins.

However, these sanitary napkins still do not sufficiently satisfy the requirements for leakage prevention, as is evident from the fact that leakage is the first cause of dissatisfaction with sanitary napkins.

That is, the liquid is absorbed by the ion osmotic pressure,
In the case of a superabsorbent polymer of the type to be retained, the absorption rate of body fluid is limited, and furthermore, the body fluid cannot be absorbed unless the superabsorbent polymer is wet with the body fluid. Although it was necessary to use fast pulp in combination, the pulp, when forming a flexible flap absorbing layer as an absorber, to absorb blood in a spot, to efficiently use the entire absorber There is a problem of poor diffusivity.

Further, pulp exhibits a certain degree of compression and bending recovery when dry, but has an extremely low strength when wet and exhibits little compression and bending recovery. Therefore, when stress is applied to wet pulp, pulp becomes However, there is a problem in that the body fluid undergoes compressive deformation (hereinafter referred to as “sore”), the absorption space thereof is significantly reduced, and the bodily fluid once absorbed easily returns to the body side with the twist and leads to stickiness and leakage. .

[0007] Further, the decrease in the pulp fiber space due to the twisting leads to an increase in the resistance of bodily fluids to the polymer,
Not only does the absorption efficiency of the polymer decrease, but also as a whole, the reabsorption rate of the absorbent after retorting significantly decreases.
It often leads to leaks.

Therefore, in order to improve the diffusivity of the pulp and the reduction of the absorption space due to the twist, a technique has been reported in which the pulp is compressed / densified to improve the diffusivity and liquid returnability. I have.

However, the above-mentioned technology does not solve the essential problem that the strength is extremely reduced when the pulp is wet, and conversely, the distance between the fibers of the pulp becomes too close, so that the polymer becomes poor. However, there is an inconvenience that the transfer resistance of blood to the blood becomes extremely large, and as a result, the absorption efficiency of the polymer used together deteriorates.

[0010] Also, Japanese Patent Application Laid-Open No. 4-89053 discloses that
An ultra-thin, highly comfortable, highly absorbent sanitary napkin is shown. The sanitary napkin improves the polymer absorption efficiency by combining a highly diffusible absorbent sheet and a specific polymer sheet, and achieves both ultrathinness and high absorbency.

Certainly, this technology has improved the absorption efficiency of the polymer, and has provided an extremely thin sanitary napkin with a high absorbency to some extent. However, expectations and demands for further consumer comfort and absorbability have been obtained. At present, there is a demand for the development of an ultra-thin napkin which is free of liquid return, stickiness and leakage even when worn for a long time with a high excretion amount and which has high absorption performance.

Conventionally, when the amount of the superabsorbent polymer used in the absorber is increased in order to improve the absorption performance, the absorption performance is improved along with the increase in the amount of the polymer up to a certain region. In addition, the voids between the polymer particles after absorbing blood are extremely reduced, and the absorption performance is deteriorated due to the deterioration of the reabsorption rate.

[0013] That is, conventionally, the amount of the polymer used is limited due to gel blocking of the polymer, and the absorption performance such as liquid return and leakage performance when worn for a long time or under the condition of extremely large excretion is completely reduced. At present, a sanitary napkin satisfying the above conditions has not been obtained.

[0014] Accordingly, the object of the present invention is to suppress the amount of liquid return and liquid leakage even when worn for a long time and under extremely large amounts of excretion, which cannot be achieved with conventional sanitary napkins. An object of the present invention is to provide an extremely thin sanitary napkin having high absorbency and high comfort.

Specifically, even when a large amount of the superabsorbent polymer is used, the performance of the superabsorbent polymer is maximized without causing absorption inhibition, and most of the excreted blood is completely made of the polymer. An object of the present invention is to provide a highly absorbable sanitary napkin that can be immobilized.

[0016]

Means for Solving the Problems As a result of intensive studies to solve the above problems, the present inventors have provided an absorber having a centrifugal holding capacity and a permeation speed of pseudo blood after specific equilibrium swelling. The present inventors have found that a sanitary napkin can achieve the above object, and have completed the present invention.

That is, the present invention relates to a sanitary napkin having a liquid-permeable surface material, a liquid-retentive absorber, and a liquid-impermeable leakproof material. The centrifugal retention capacity after absorption and swelling is 30 g or more. B) The absorber is a cylinder having a cross-sectional area of 10 cm ² (with a circular diameter of 35 cm ² ).
8 mmφ) with a thickness of 0.5 to 5 mm, equilibrium swelling with pseudo-blood, and then a permeation speed of 50 ml / min or more when permeating pseudo-blood. To provide.

Therefore, as described above, the sanitary napkin of the present invention has both a very high centrifugal retention capacity and a blood flow property after absorbing blood, which cannot be obtained with a conventional sanitary napkin absorber. Characterized by using an absorber satisfying the following.

[0019]

The sanitary napkin of the present invention is excreted because it has an absorber having both a very high blood holding capacity and a high permeation rate after absorption (high blood flow). Blood can be reliably fixed by the absorber. In addition, since the blood flow after absorption is high, the rate of reabsorption is high even when the blood is repeatedly excreted, and the blood can be reliably fixed even at the time of higher excretion.
As a result, the sanitary napkin of the present invention has a small amount of liquid returning to the surface, not only when the amount of bodily fluid discharged is small, but also during high absorption when worn for a long time during high excretion, causing stickiness and leakage. It is a less comfortable sanitary napkin.

[0020]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the present invention will be described in detail with reference to the drawings, and the present invention will be specifically described with reference to examples and comparative examples. However, the present invention is not limited to these.

First, the present invention will be described with reference to FIGS. Here, FIG. 1 is a cross-sectional view showing a cross section in the width direction of an example of the sanitary napkin of the present invention, and FIG. 2 and FIG.
It is FIG. 1 equivalent view which shows the other example of the sanitary napkin of this invention.

As shown in FIG. 1, a sanitary napkin 10 of the present invention comprises a liquid-permeable surface material 1 and a liquid-retentive absorber 2.
And a liquid-impermeable leakproof material 3, wherein the absorber 2 is
a) The centrifugal holding capacity after equilibrium absorption swelling of the simulated blood is
30 g or more, b) The absorber 2 is fixed to a cylinder (circle diameter 35.8 mmφ) having a cross-sectional area of 10 cm ² with a thickness of 0.5 to 5 mm, equilibrium swelled with simulated blood, and then permeated with simulated blood. The permeation speed at this time is 50 ml / min or more.

More specifically, the sanitary napkin 10
Is formed to be substantially vertically long, so that when the sanitary napkin 10 is worn, the surface material 1 is located on the front side in contact with the skin, and the leak-proof material 3 is located on the back side in contact with the underwear. The absorber 2 is interposed between the surface material 1 and the leak preventer 3.

As shown in FIG. 1, the absorber 2 has a back surface,
The entire side surface and the peripheral edge of the surface are covered with the leakproof material 3, and the entire surface is further covered with the surface material 1. The center of the surface of the absorber 2 is directly covered with the surface material 1, so that the body fluid is directly transmitted to the absorber 2.

On the back side of the surface material 1, three adhesive portions are formed in a streak shape in the longitudinal direction, and the adhesive portions are protected by a release paper 5. In FIG. 1, reference numeral 6 denotes a joint.

Next, the characteristic portion of the present invention will be described. The sanitary napkin 10 of the present invention comprises the above absorbent 2
However, a) the centrifugal holding capacity after equilibrium absorption and swelling of the simulated blood is 30 g or more, preferably 40 to 150 g;
b) The absorber 2 is a cylinder having a cross-sectional area of 10 cm ² (circle diameter: 35.8 m).
mφ) with a thickness of 0.5 to 5 mm, equilibrium swelling with pseudo-blood, and a permeation rate of 50 ml / min or more, preferably 60 to 300 ml / mi, when permeating pseudo-blood.
n. Here, the thickness when fixing the absorber to the cylinder is different depending on the thickness and the composition of the absorber to be measured, but is fixed so that pseudo blood does not leak from the side surface of the absorber. The clearance around the cylinder is gradually reduced until the pseudo blood does not exude from the side surface of the absorber, and the absorber is fixed at the above thickness, and then the transmission speed is measured.

When the centrifugal holding capacity is less than 30 g,
Liquid return and liquid leakage performance at high absorption is insufficient. On the other hand, if the permeation rate is less than 50 ml / min, the fluidity of the blood is deteriorated, and the reabsorption characteristics particularly when the blood is repeatedly excreted are extremely deteriorated.

The above-mentioned centrifugal holding capacity is obtained by impregnating the absorber with pseudo-blood and allowing it to absorb and swell sufficiently (leaved for 30 minutes), and then centrifuging to obtain the amount of absorption that completely fixes the blood. It can be determined by measuring the amount of blood held by the absorber when blood not fixed to the absorber (blood returning to the surface by pressurization or the like) is separated.

As described above, it is essential that the absorber 2 has both a higher centrifugal retention and a higher permeation rate after blood absorption, and only one of the two requires the present invention. Effect cannot be obtained.

In addition, even when worn for a long time and when the amount of absorbed blood is large, in order to securely fix blood and prevent leakage, it is necessary not only to absorb blood in a physical space such as pulp, but also to completely absorb blood. The point is whether or not to absorb and retain with a super absorbent polymer. Therefore, in the absorption capacity of the absorber for fixing blood, not the apparent absorption amount absorbed into the fiber space such as pulp or paper, but the essential absorption and retention amount of the highly absorbent polymer is an important parameter. Therefore, in the present invention, the absorption holding capacity of the absorber 2 is evaluated by the centrifugal holding capacity, which is the holding absorption capacity that can completely fix blood with the absorber.

To improve the centrifugal retention, it can be achieved by increasing the amount of the superabsorbent polymer. Conventionally, however, if the amount of the superabsorbent polymer is increased until the intended centrifugal retention is achieved, The gaps between the polymer particles become too dense, voids between the polymer particles are lost due to swelling due to blood absorption, and blood absorbability at the time of reabsorption is extremely reduced.

[0032] Even if the amount of the superabsorbent polymer is increased and the centrifugal holding capacity of the entire absorber is improved by reducing the reabsorbability (blood flowability) after the blood absorption, the absorption amount of the entire polymer is effective. Could not be expressed in
Conventionally, there has been a limit in improving the absorption performance at the time of high absorption.

That is, conventionally, both the centrifugal holding capacity and the permeation rate after blood absorption and swelling (blood flowability) cannot be improved, and the permeation rate after blood absorption and swelling even when the centrifugal holding capacity is 30 g or more. Was less than 50 ml / min, and the blood flow after blood absorption was insufficient, so that the reabsorption rate was poor and the polymer leaked before reabsorption.

In the present invention, as the absorber 2,
Since an absorber having both a higher centrifugal holding capacity and a permeation rate after blood absorption is used, an effect is obtained which has not been achieved conventionally and is hardly leaked even at a higher absorption amount.

As shown in FIG. 1, the absorber 2 is provided on the uppermost layer surface side 1 and has a highly absorbent absorbent sheet 2a and a lower layer of the absorbent sheet 2a.
A highly diffusive and highly absorbent absorbent sheet 2b enclosing the superabsorbent polymer 2c.

That is, as long as the absorber 2 has both the above-mentioned centrifugal retention capacity and the permeation rate after absorption and swelling, any structure is not particularly limited, but their physical properties can be more reliably ensured. It is preferable to have a superabsorbent polymer in order to express it. The superabsorbent polymer has a) a centrifugal retention capacity of 20 g / g or more after simulated blood equilibrium absorption and swelling, and b) a cylinder having a cross-sectional area of 0.785 cm ² of 0.05 g of the superabsorbent polymer. (Circle diameter: 10 mmφ), and is preferably swollen by pseudo-blood, and then the permeation speed when permeating the pseudo-blood is 1 ml / min or more.

The centrifugal retention capacity of the superabsorbent polymer is 2
If the amount is less than 0 g / g, the ability to absorb and retain the liquid is poor, which is not preferable. In the case of a highly absorbent polymer having a blood permeation rate of less than 1.0 ml / min, the liquid flowability of the polymer after liquid absorption is poor, Is not preferable because it cannot be expressed efficiently.

The method for measuring the blood permeation rate is shown in FIG.
As shown in FIG.
It can be obtained by putting the mixture in a 785 cm ² cylinder (inner diameter 10 mmφ), swelling the polymer with pseudo-blood, reaching the equilibrium swelling absorption amount, and measuring the permeation rate after the swollen polymer precipitates.

The composition and the production method of the superabsorbent polymer 2c are not particularly limited as long as they have the physical properties a) and b). A crosslinked product of a high molecular weight polyacrylate which does not leak even under pressure is preferable, and has a function of quickly absorbing liquid from a sheet having fine spaces, and its surface is kept dry after swelling, and the Those that do not hinder movement are preferred.

In addition, it is difficult to exhibit such an absorbing function when the superabsorbent polymer has a uniform crosslinked structure, and therefore, the superabsorbent polymer may have a crosslink density gradient. preferable. As a method for imparting a crosslinking density gradient to the superabsorbent polymer, for example, when polyacrylic acid is used as the superabsorbent polymer, the polyacrylic acid is further reacted with a crosslinking agent capable of reacting with the functional group of the polyacrylate. Examples of the method include a method of causing the surfaces to crosslink with each other by reacting with a salt. In particular, by adjusting the amount of the crosslinker used, the crosslink density gradient can be adjusted.

As the crosslinking agent, a water-soluble compound having two or more functional groups capable of reacting with a carboxyl group is preferable. For example, ethylene glycol diglycidyl ether, polyethylene glycol diglycidyl ether,
Polyglycidyl ethers such as glycerin triglycidyl ether, epichlorohydrin, haloepoxy compounds such as α-methylchlorohydrin, glutaraldehyde,
Examples thereof include polyaldehydes such as glyoxal, polyols such as glycerin, pentaerythritol, and ethylene glycol, and polyamines such as ethylene diamine. Crosslinking agents having three or more functional groups are particularly preferable.

It is preferable that the superabsorbent polymer has a non-spherical shape with an irregularity P of a particle form of 1.2 or more.

When the superabsorbent polymer has such a non-spherical shape, it is possible to prevent a decrease in voids due to rearrangement and adhesion of particles after swelling. When the irregularity P is 1.
If it is smaller than 2, the irregularity value of the surface irregularities of the swollen particles becomes insufficient, the space cannot be maintained between the swollen particles, and the liquid flow property between the particles deteriorates.

The irregularity P expresses the roughness of the superabsorbent polymer particles, and can be obtained by the following [Equation 1].

[0045]

(Equation 1)

The actual area S and the perimeter l of the projected particles when calculating the irregularity P are observed as the projected particles with the "IV Image Processor EXCEL", a trade name of Nippon Avionics Co., Ltd. It can be measured.

By controlling the cross-link density gradient by adjusting the amount of the cross-linking agent or the like, as described above, the preferable absorbent properties of the super-absorbent polymer can be obtained.
The above-mentioned absorption properties can be further improved not only by such chemical structure control but also by physical structure control such as the particle form of the superabsorbent polymer.

That is, after the superabsorbent polymer has absorbed the liquid and reached the swelling equilibrium, the physical form of the swollen polymer also has a great influence on the flowability of the liquid. When a large amount of is used, the polymer particles are likely to be closely packed with each other, and the voids between the particles are extremely reduced,
Since the fluidity of the liquid is deteriorated, it is preferable to design the form of the polymer particles having the above-mentioned irregularity P so that the polymer particles are swollen and aggregated with voids between the particles.

The superabsorbent polymer having the irregularity degree P can be obtained by pulverizing the superabsorbent polymer obtained by the bulk polymerization. Further, an amorphous polymer composed of agglomerates having polymer particles obtained by contact reaction as primary particles can be more preferably used.

The amount of the superabsorbent polymer used is as follows:
20 to 80% by weight, and more preferably 30 to 80% by weight based on the entire absorbent body
６０60% by weight and the spray basis weight is 100 to 500 g /
m ² , more preferably 100 to 300 g / m ² . That is, the amount of the superabsorbent polymer to be used is preferably 1 to 5 g, more preferably 1 to 3 g per normal product. If the amount of the superabsorbent polymer used is less than 1 g (20% by weight) or the basis weight of the applied material is less than 100 g / m ² , the amount used is too small and it is insufficient to completely immobilize the liquid when excreting a large amount. No, and when the amount used exceeds 5 g (80% by weight) or when the basis weight is 500
If it exceeds g / m ² , it is difficult to completely immobilize the superabsorbent polymer in the product, which is not preferable.

In order to form an absorbent body using the above-described high-absorbency polymer, a structure used in combination with flap pulp (see FIG. 3) and a structure sandwiching the polymer between absorbent papers (see FIG. 1) For example, in the case of a highly viscous liquid such as blood, the design of an absorption space made of paper, pulp fiber, or the like that temporarily stores the liquid is an important point. That is, in an absorber mainly composed of a flap pulp sheet made of ordinary softwood pulp, before the function of the absorbent polymer is maximized, the pulp twist /
Settling causes the absorption rate to deteriorate, leading to leakage.

Further, it is preferable that at least a part of the absorber 2 is composed of bulky cellulose fibers and a superabsorbent polymer, since a highly absorbent absorber can be obtained more reliably. The bulky cellulose fiber,
a) The fiber cross-sectional area is 3.0 × 10 ⁻⁶ cm ² or more and the circularity of the cross section is 0.5 or more; or b) The fiber cross-sectional area is 5.0 × 10 ⁻⁶ cm ² or more. Or c) the fiber shape has a three-dimensional shape. The method for measuring the roundness and the like will be described later. Examples of the three-dimensional shape include a twisted shape, a crimped shape, and a bent shape.

The bulky cellulose fiber may be directly mixed with a superabsorbent polymer to form an absorbent, but it is used as an absorbent sheet made of bulky cellulose fiber by papermaking in a wet process. The body may be composed.

As the bulky cellulose fiber,
More preferably, crosslinked cellulose having an improved elastic modulus at the time of wet wetting is preferably used by crosslinking the inside and between the cellulose molecules with a suitable crosslinking agent so as to maintain a bulky structure even in a wet state.

At this time, any cellulose fiber that can be used may be any of natural cellulose fibers such as pulp and cotton and regenerated cellulose such as rayon and cupra, as long as the above requirements a), b) and c) are satisfied. One type of these may be used, or a mixture of several types may be used. Among them, a regenerated cellulose fiber in which the fiber cross-sectional area and cross-sectional shape can be freely controlled, and a mercerization in which the fiber cross-section is swollen / increased. Pulp and cellulose fibers obtained by crosslinking them are most preferably used.

Examples of the crosslinking agent used for crosslinking cellulose as described above include N-methylol compounds such as dimethylol ethylene urea and dimethylol dihydroxyethylene urea, tricarballylic acid citrate, butanetetracarboxylic acid and the like. And a polyol such as dimethyldihydroxyethylene urea and a polyglycidyl ether-based crosslinking agent are preferably used.

Absorbent paper obtained by wet-making ordinary natural pulp containing no bulky cellulose fiber in the wet process occupies most of the conventional absorbent paper. However, absorbent paper made of natural pulp such as softwood pulp is used for papermaking. In the dehydration / wet pressure / drying process, when the water is dehydrated / dried, a very strong tightening force acts between the pulp fibers due to the interfacial tension of the water and hydrogen bonding. Since the pulp fibers are tightened by the tightening force, the conventional absorbent paper not only has a very slow absorption / permeation of the liquid, but also has a significantly reduced fiber space that substantially absorbs the liquid.

Therefore, as described above, by mixing bulky cellulose fibers, hydrogen bonding between the fibers is suppressed, the absorption space is increased, and the absorption / permeation / diffusion of the liquid is idealized. It is preferable to use a flexible sheet together with the superabsorbent polymer.

Next, the absorbent sheet 2a containing the superabsorbent polymer and the bulky cellulose fiber in the absorbent body 2
Will be described.

As described above, the absorber 2 shown in FIG.
The non-skin contact surface side of the liquid-permeable surface material 1, that is, the uppermost layer of the absorber, is provided with an absorbent sheet 2a having a high permeability to quickly absorb and transmit blood. And the absorption sheet 2a is
It is preferable to control the spreading characteristic (diffusion characteristic).

The absorbent sheet 2a used as the uppermost layer of the above-mentioned absorbent includes: a) the bulky cellulose fibers described above;
50 to 98 parts by weight, b) hot-melt adhesive fiber, 2 to 30
Parts by weight and an absorbent sheet obtained by mixing papermaking,
Krem absorption height after 1 minute against physiological saline is 20-8
0mm and Krem absorption height after 10 minutes is 30-100mm
The permeation time of 10 g of an 85% by weight aqueous glycerin solution is preferably 50 seconds or less. Here, the Krem absorption height and the transmission time will be described later.

As the above-mentioned hot-melt adhesive fibers, fibers which are melted by heating and adhere to each other are used. For example, polyethylene, polypropylene, polyester, and olefin fibers such as polyvinyl alcohol, polyethylene-polypropylene composite fiber, polyethylene-polyester composite fiber, low-melting polyester-polyester composite fiber and polyvinyl alcohol-polypropylene composite fiber whose fiber surface is hydrophilic, Polyvinyl alcohol-polyester composite fibers can be more preferably used.

The mixing ratio of the hot-melt adhesive fiber to the entire absorbent sheet 2a is preferably 2 to 30 parts by weight, more preferably 2 to 20 parts by weight. Mixing ratio is 3
If the amount exceeds 0 parts by weight, the permeability of the absorbent sheet may decrease, which is not preferable.

The absorber 2 has an absorbent sheet 2b, that is, an absorbent sheet 2b for holding an absorbent polymer, under the absorbent sheet 2a used as the uppermost layer. As the absorbent sheet 2b, the absorbent sheet 2a
A highly diffusive and highly permeable sheet is preferable so that blood permeated through the polymer can be quickly diffused throughout the polymer and then smoothly pass the liquid to the polymer. Specifically, a sheet having the following composition and the following physical properties Is preferred.

A) Bulk cellulose fibers, 20 to 80
Parts by weight, b) hydrophilic fine fibers, 80 to 20 parts by weight, and c) hot-melt adhesive fibers, 0 to 30 parts by weight. The Klemm absorption height after 50 minutes is 50 mm or more, the Krem absorption height after 10 minutes is 100 mm or more, and the permeation time of 10 g of 85% by weight glycerin aqueous solution is 100 seconds or less.

The bulky cellulose fiber used in this case has a fiber cross-sectional area of 3.0 × 10 ⁻⁶ cm.
^It is preferable that the mercerized pulp having a circularity of ² or more and a roundness of a cross section of 0.5 or more further be made of pulp further crosslinked with a crosslinking agent.

As the above-mentioned hydrophilic fine fibers, fibers having a hydrophilic fiber surface and a large surface area, preferably having a cross-sectional area of 2.0 × 10 ⁻⁶ cm ² or less and having a true cross-section, Preferred are hydrophilic fibers having a circularity of less than 0.5 or a fiber surface area of 1.0 m ² / g or more. Such fibers include, for example, pulp, cotton,
Examples thereof include cellulose fibers typified by rayon and the like and hydrophilic synthetic fibers such as acrylonitrile and polyvinyl alcohol. Among these, only one kind may be used, or a mixture of several kinds may be used.

Among them, pulp fibers can be preferably used because they are very inexpensive and the fiber surface area can be controlled by beating conditions. For example, "kraft pulp NBKP" (trade name; SKEENA PRIME Skeen
a Cellulose Co.) and “LBK”
P "(trade name; PRINCE ALBERT ASPEN HARDWOOD, Waferuser Paper Co., Ltd.) and straw pulp.

The method of combining the highly diffusive and highly permeable absorbent sheet 2b and the highly absorbent polymer 2c is not particularly limited, and as shown in FIG. 1, only one sheet 2b is used. The superabsorbent polymer 2c may be wrapped and integrated, or as shown in FIG. 2, the superabsorbent polymer 2b may be scattered in multiple layers and integrated. From the viewpoint of blood permeability, a structure in which the polymer particles are dispersed in multiple layers (that is, the structure shown in FIG. 2) is preferable in order to increase the interval between the polymer particles.

Instead of forming a polymer sheet with a highly diffusive and highly permeable absorbent sheet, as shown in FIG. 3, a highly absorbent polymer 2c and flap pulp 2d may be mixed and used. Here, the flap pulp 2d may be formed using a conventional softwood pulp. However, in order to stabilize the gap between the polymer particles when wet, that is, to improve blood permeability, Pulp fibers, in particular, pulp obtained by further cross-linking mercerized pulp having a fiber cross-sectional area of 3.0 × 10 ⁻⁶ cm ² or more and a roundness of cross-section of 0.5 or more and improving the elasticity of WET are the most preferable. It can be used preferably. FIG.
The points which are not described in detail in the example shown in FIG. 3 are the same as those in the example shown in FIG.

As described above, the sanitary napkin of the present embodiment combines a high-permeability, high-permeability absorbent polymer with a high-permeability absorbent sheet made of bulky cellulose fibers to achieve a conventional sanitary napkin. By obtaining an absorbent that has high blood retention and high blood permeability that could not be removed, it has very high comfort without liquid return, stickiness or leakage even when worn for a long time with high excretion. is there.

Next, the sanitary napkin of the present invention will be specifically described based on the following examples. First, the superabsorbent polymer and the absorbent sheet used in this example and comparative example were prepared in the following manner, and their functions were measured. In the description, “%” indicates “% by weight” unless otherwise specified.

(1) Preparation of superabsorbent polymer Superabsorbent polymer (A) 230 ml of cyclohexane and sorbitan were placed in a 500 ml four-necked round bottom flask equipped with a stirrer, a reflux condenser, a dropping funnel and a nitrogen gas inlet tube. Monostearate [Product name;
"Reodol SPS-12", manufactured by Kao Corporation] 1.4 g
And stirred to obtain a homogeneous solution. Separately, in an Erlenmeyer flask, 30 g of acrylic acid monomer and 39 g of water
The solution was neutralized with 13.4 g of caustic soda dissolved in water to obtain a monomer aqueous solution having a monomer concentration of 45% (water content 55%).
Subsequently, 0.1% potassium persulfate was added to the aqueous monomer solution.
g was added and dissolved. The obtained monomer aqueous solution was dropped into the above four-necked round bottom flask charged with cyclohexane and the like under a nitrogen atmosphere, and then heated to 70 to 75 ° C. to start polymerization.

Then, the amount of water in the polymer suspended in cyclohexane was controlled to 35% by azeotropic dehydration (cyclohexane was refluxed). Thereafter, 0.03 g of ethylene glycol diglycidyl ether was added to 1 ml of water.
Was added at 73 ° C., and kept at this temperature for 2 hours, after which cyclohexane was removed. The resulting polymer was dried at 80 to 100 ° C. under reduced pressure to obtain a polymer having a high absorption as shown in Table 1 below. The functional polymer (A) was obtained.

Superabsorbent polymer (B) 40 g of the above superabsorbent polymer (A) was again put into a 500 ml four-necked round bottom flask together with 230 ml of cyclohexane, and water was added to control the water content to 35%. Then, the temperature was raised to 75 ° C. After reaching a constant temperature, ethylene glycol diglycidyl ether (2,500 ppm based on the polymer) was added to each. Then, change this to 7
After maintaining at 5 ° C. for 3 hours, cyclohexane was removed, and the obtained polymer was dried under reduced pressure at 80 to 100 ° C. to obtain a superabsorbent polymer (B) shown in the following [Table 1].

Superabsorbent polymer (C) A commercially available superabsorbent polymer (trade name: “AQUALIC CA
-W4 "manufactured by Nippon Shokubai Co., Ltd.]
And

Superabsorbent polymer (D) The solution in a four-necked round-bottom flask charged with cyclohexane and the like was heated to 70 to 75 ° C., and an aqueous monomer solution was added dropwise thereto over 1.5 hours under a nitrogen atmosphere. After polymerization, 70-
Other than maintaining at 75 ° C. for 0.5 hour and terminating the polymerization,
Superabsorbent polymer (D) shown in the following [Table 1] was obtained in the same manner as in the production of superabsorbent polymer (A).

Superabsorbent polymer (E) Except that 1.94 g of ethyl cellulose (trade name; "N-200", manufactured by Hercules Far East Co., Ltd.) was used instead of "Reodol SPS-12" as a dispersion medium. In the same manner as in the above-mentioned superabsorbent polymer (D), superabsorbent polymer (E) shown in the following [Table 1] was obtained.

The highly absorbent polymers (A) to
The irregularity of (E), the amount of retained and absorbed blood after centrifugation with simulated blood, and the permeation rate were measured by the following methods. The results are shown in [Table 1].

[0080]

[Table 1]

<Measurement of centrifugal retention> Superabsorbent polymer 1
g was placed in a beaker containing 500 ml of simulated blood prepared as described below, and left as it was for 30 minutes. The superabsorbent polymer which has been sufficiently absorbed and swelled is made into a bag shape with paper and nonwoven fabric so that the polymer does not fall off, and is completely fixed to the polymer by a centrifugal separator (Domestic Centrifuge Co., Ltd.) Model H-130C. 2000 rpm / to determine the amount of simulated blood
After rotating at a rotation speed of min (centrifugal acceleration of 895 G) for 10 minutes, the weight was measured, and the retained absorption amount after centrifugation (centrifugal retained amount) was determined by the following equation (2).

[0082]

(Equation 2)

<Measurement of Liquid Permeation Rate of Superabsorbent Polymer> Apparatus 10 shown in FIG. 4 [inner diameter 14.6 mm, length about 250
A burette consisting of a glass cylindrical tube of mm (cylindrical part)]
Was filled with 0.05 g of superabsorbent polymer P, and the excess simulated blood was used to equilibrate and swell the polymer.
The cock was opened according to mm, and after confirming that the swollen polymer P had settled out sufficiently as shown in the figure, the cock was opened, and the pseudo blood passed between the two evaluation lines L and M shown in the figure (5 ml of liquid). And the passage speed of the liquid was determined by the formula shown in the following [Equation 3].

[0084]

(Equation 3)

<Preparation of Simulated Blood> 1500 g of ion-exchanged water was charged into a beaker, and 5.3 g of sodium carboxymethylcellulose was completely dissolved therein. Next, 556 g of ion-exchanged water was weighed separately, and 27.0 NaCl was added.
g and 12 g of NaHCO ₃ were dissolved. The above two solutions and 900 g of glycerin are mixed, and 15 ml of a 1 g / liter solution of a surfactant (trade name: "Emulgen 935", manufactured by Kao Corporation) is added.
Was added and mixed until completely dissolved, and the resulting solution was used as simulated blood.

(2) Preparation of Absorbent Sheet Absorbent Sheet (A) As a bulky cellulose fiber, the fiber cross-sectional area is 3.8 ×
Mercerized pulp with 10 ^-6 cm ² and a roundness of fiber cross section of 0.80 (trade name: POROSENIA J, ITT RAY ONIER IN
C.) 70 parts by weight and a fiber cross-sectional area of 5.9 × 10 ⁻⁶ cm ²
20 parts by weight of rayon (trade name: Corona SB rayon, Daiwa Bow Rayon Co., Ltd.) having a roundness of a fiber section of 0.68 and a length of 8 mm, polyvinyl alcohol (trade name: Fibribond) as a heat-fusible adhesive fiber 5 parts by weight, Kraft pulp NBKP (trade name; SKEENA PRIME, Skeena Cekkukose C)
O.) 10 parts by weight of each were dispersed and mixed in water, papermaking and drying were performed, and a sheet made to a basis weight of 40 g / m ² was designated as an absorbent sheet (A).

Here, in measuring the cross-sectional area of the fiber, the cross section of the fiber is sliced vertically so that the area does not change, and a cross-sectional photograph is taken with an electron microscope. The cross-sectional area of the cross-sectional photograph of the fiber was measured with an image analyzer (Avio EXCEL, manufactured by Nippon Avionics). An arbitrary fiber cross section was measured at 100 points, and the average value was defined as the fiber cross section area.

Next, the roundness of the fiber cross section was determined by similarly using a cross-sectional photograph and an image analyzer to calculate the roundness of the fiber cross section using the following equation (4). The roundness was determined by measuring an arbitrary fiber cross section at 100 points and calculating the average value.

[0089]

(Equation 4)

Absorbent sheet (B) Mercerized pulp (trade name; Porosenia J, ITT) which is a bulky cellulose fiber used for absorbent sheet (A)
RAYONIER INC.) As a crosslinking agent, dimethylol dihydroxyethylene urea (trade name: Sumitex Resin NS-19)
And Sumitomo Chemical Co., Ltd.) in an aqueous solution containing 5 wt% and a metal salt catalyst (trade name: Sumitex Accelerator X-110, manufactured by Sumitomo Chemical Co., Ltd.) in an amount of 3 wt%, and impregnated with a crosslinking agent. After that, the aqueous solution of the cross-linking agent is
Separated to 00 wt%, 135C in electric dryer
For 10 minutes to cause a cross-linking reaction of cellulose in the pulp to obtain a cross-linked pulp. 95 parts by weight of the obtained crosslinked pulp and 5 parts by weight of polyvinyl alcohol (trade name: Fibribond, Sansho Co., Ltd.) as hot-melt adhesive fibers were dispersed and mixed in water, papermaking and drying were performed. 40g
/ M ² was designated as an absorbent sheet (B).

Absorbent sheet (C) As bulky cellulose fiber, crosslinked pulp having a twisted structure [trade name: High Bulk Additive (hereinafter referred to as “HB
A "), manufactured by Wafer Weather Paper Co., Ltd.] 40 parts by weight, as hydrophilic fine fibers, having a fiber cross-sectional area of 1.9 ×
Kraft pulp NBKP (trade name; SKEENA PRIME, Skeena Cellu) having 10 ^-6 cm ² and a roundness of fiber cross section of 0.32
lose CO.) 50 parts by weight, as a hot-melt adhesive fiber, 10 parts by weight of polyethylene terephthalate (hereinafter referred to as PET) having a thickness of 1.1 denier and a length of 5 mm (trade name: TMOTNSB, Teijin Limited) Were dispersed and mixed in water, paper-made and dried to obtain a paper-absorbent sheet (C) having a basis weight of 40 g / m ² .

Absorbent Sheet (D) As a bulky cellulose fiber, 60 parts by weight of pulp obtained by crosslinking the mercerized pulp used in the absorbent sheet (B) is used. As hydrophilic fine fibers, the fiber cross-sectional area is 1.9. × 1
0 ^-6 cm ^2, kraft pulp NBKP (trade name is roundness 0.32 fiber cross-section; SKEENA PRIME, Skeena Cellulo
se CO.) was dispersed and mixed in water, paper-made and dried to obtain an absorbent sheet (D) having a basis weight of 40 g / m ² .

Absorbent sheet (E) Kraft pulp NBKP (trade name: SKEE) having a fiber cross-sectional area of 1.9 × 10 ^-6 cm ² and a roundness of fiber cross-section of 0.32
NA PRIME, Skeena Cellulose CO.) Was dispersed in water, and paper drying afforded an absorbent sheet having a basis weight of 40g / m ² (E). This absorbent sheet (E) is composed of only hydrophilic fine fibers (kraft pulp NBKP) and does not contain bulky hydrophilic fibers.

Absorbent sheet (F) A rayon stable (Daiwabo Rayon Co., Ltd.) having a thickness of 0.7 denier and a length of 38 mm was obtained by entanglement of fibers with a water jet. A spunbond nonwoven fabric having a basis weight of 40 g / m ² was used as the absorbent sheet (F). In this absorbent sheet (F), bulky hydrophilic fibers are not mixed.

Absorbent Sheet (G) A dry pulp sheet having a basis weight of 40 g / m ² (trade name: Kinocross, Honshu Paper Co., Ltd.) was used as the absorbent sheet G. In this absorbent sheet (G), the hydrophilic fine fibers and the bulky hydrophilic fibers are not mixed.

Next, in each of the absorbent sheets (A) to (G), the Klemm absorption height and the glycerin passing time of 85% by weight after 1 minute and 10 minutes with respect to physiological saline were determined, respectively. The results are shown in Table 2 below.

[0097]

[Table 2]

<Krem absorption height after 1 minute and 10 minutes>
First, an absorptive sheet was cut into a length of 250 mm and a width of 20 mm to prepare a measurement piece. Next, this measuring piece 30 is
As shown in (1), the support 31 was hung so that there was no slack, and both upper and lower ends were fixed. Also, 300 × 100 × 50mm
Physiological saline solution 33 is placed in a rectangular parallelepiped container 32 (length x width x depth)
To a height of 40 mm as a measuring solution, and this physiological saline 3
3 is immersed in the measuring piece 30. After the measurement piece 30 was immersed, the height of the regulated liquid absorbed by the measurement piece 30 from the liquid level one minute later and the height of the measurement liquid absorbed by the measurement piece 30 after 10 minutes were measured. The same measurement was performed for a total of 10 points, and the average value was taken, and the absorption height h after 1 minute was measured,
And it was absorbed a height h ₁₀ of the saline 33 after 10 minutes.

<Measurement of liquid passage time> The measurement of the liquid passage time was performed using a measuring apparatus shown in FIG. First, the absorptive sheet was cut into 50 mm in length and 50 mm in width,
Then, as shown in FIG.
The glass tubes 41, 41 having an inner diameter of 35 mm were clamped and fixed from both upper and lower sides. At this time, the liquid was fixed from both sides with clips via the silicone rubber 42 so that the liquid did not seep from the side during the measurement. 10 g of a glycerin 85% aqueous solution 43 prepared and mixed at the ratio shown below as a measurement liquid in a 10 ml beaker 44.
And injected gently. After injecting the glycerin 85% aqueous solution 43, the time required for the surface of the measurement piece to appear by 50% or more with respect to the open area of the glass tube 41 was determined and defined as the liquid passage time. Measurement solution (85% glycerin aqueous solution)
Was adjusted as follows. After mixing 15 g of ion-exchanged water with 85 g of glycerin (Wako Pure Chemical Industries, Ltd.), 0.01 g of Food Blue No. 1 (Tokyo Kasei Kogyo Co., Ltd.) was added, and the mixture was colored blue.

[Example 1] As shown in FIG.
As the absorbent sheet 2b having a width of 190 mm and a width of 190 mm, an absorbent sheet (C) was used, on which hot melt (trade name: Topco P-618B, Toyo Petrolite Co., Ltd.) was spirally shaped and weighed 10 g. After spraying at 1.5 g / m ² , 1.5 g of the superabsorbent polymer (A) was spread almost uniformly over a width of 75 mm as the superabsorbent polymer 2c (spread basis weight of about 114 g).
g / m ² ), wrapped and integrated to obtain a polymer sheet. Further, the absorbent sheet (A) was used as the absorbent sheet 2a, cut into a length of 175 mm and a width of 130 mm, and wrapped and integrated with the polymer sheet to constitute an absorbent body 2. The obtained absorbent body 2 is made of polylami waterproof paper (length 205
mm, width 95 mm) as the leak-proof material 3.

The surface material 1 was made of a polyethylene / polypropylene conjugate fiber (manufactured by Chisso Corporation) to which 0.34% by weight of a mixed surfactant of an alkyl phosphate and a sorbitan fatty acid ester was adhered.
The g / m ² of dry thermal bonding nonwoven fabric, as shown in FIG. 7, on the non-woven fabric 22, a low density polyethylene 21 (manufactured by Mitsui Petrochemical Industries, Ltd.) obtained by 25μ laminated, opening of the wall 23 24 A surface material having a size of 0.1 to ² mm ² and a hole density of 52 / cm ² was cut into a length of 205 mm and a width of 170 mm. Using the surface material, the above-mentioned polymer sheet wound up with a leak-proof material was wrapped, and a sanitary napkin (product 1 of the present invention) having the structure shown in FIG.

[Embodiment 2] As shown in FIG.
After the hot melt is sprayed at a rate of about 10 g / m ² in a spiral shape between a total of three absorbent sheets (D) using the absorbent sheet (D) as the absorbent sheet 2b having a width of 75 mm and a width of 75 mm, As the absorbent polymer 2c, the superabsorbent polymer (A) was almost uniformly wrapped and integrated with 1 g each for a total of 2 g (about 152 g / m ² as a total spray basis weight) and integrated. Further, the absorbent sheet (B) was used as the absorbent sheet 2a, cut into a length of 175 mm and a width of 130 mm, and wrapped and integrated with a polymer sheet to form an absorber shown in FIG. Except for this, a sanitary napkin (the present invention product 2) was prepared in the same manner as in Example 1.

Example 3 An absorbent was prepared in the same manner as in Example 2 except that the superabsorbent polymer (B) was used instead of the superabsorbent polymer (A) used in Example 2. A sanitary napkin (product 3 of the present invention) having the configuration shown in FIG. 2 was prepared.

Example 4 An absorber was prepared in the same manner as in Example 2 except that the superabsorbent polymer (C) was used instead of the superabsorbent polymer (A) used in Example 2. A sanitary napkin (product 4 of the present invention) having the configuration shown in FIG. 2 was prepared.

Example 5 As shown in FIG. 3, pulp 2d
2 g of pulp obtained by cross-linking the mercerized pulp used in the absorbent sheet (B) (basis weight: about 152 g / m ² ); and as the super absorbent polymer 2c, the super absorbent polymer (B) 2
g (about 152 g / m ² as basis weight) were mixed to form a sheet. Further, the absorbent sheet (B) was used as the absorbent sheet 2a, cut into a length of 175 mm and a width of 130 mm and integrated to form an absorbent body 2. Hereinafter, in the same manner as in Example 1, a sanitary napkin (product 1 of the present invention) having the configuration shown in FIG. 3 was prepared.

Comparative Example 1 The absorbent sheet (E) was used as the absorbent sheet 2b in place of the absorbent sheet (C) used in Example 1, and the absorbent sheet (A) was used as the absorbent sheet 2a. Instead, the absorbent sheet (E) is used, and as the superabsorbent polymer, instead of the superabsorbent polymer (A),
A sanitary napkin having the configuration shown in FIG. 1 (Comparative product 1) was prepared in the same manner as in Example 1 except that the superabsorbent polymer (D) was used.

Comparative Example 2 The absorbent sheet (G) used as the absorbent sheet 2b and the absorbent sheet (B) as the absorbent sheet 2a used in Example 2 were used instead of the absorbent sheet (D). Instead of using the absorbent sheet (G), and as the superabsorbent polymer, instead of the superabsorbent polymer (A),
A sanitary napkin (comparative product 1) was prepared in the same manner as in Example 2 except that 0.7 g of the superabsorbent polymer (E) was used.

Comparative Example 3 Pulp 2 used in Example 5
As d, softwood pulp (NB-420, Waferwather Paper Co., Ltd.) is used instead of the pulp obtained by cross-linking mercerized pulp, and as the absorbent sheet 2a, the absorbent sheet (F) is used instead of the absorbent sheet (B). And a sanitary napkin (comparative product) having the configuration shown in FIG. 3 in the same manner as in Example 5 except that the superabsorbent polymer (D) is used instead of the superabsorbent polymer (B) as the polymer 2c. 1) was created.

Comparative Example 4 Pulp 2 used in Example 5
As d, softwood pulp (NB-420, Waferwather Paper Co., Ltd.) was used instead of the pulp obtained by crosslinking mercerized pulp, and as the absorbent sheet 2a, the absorbent sheet (E) was used instead of the absorbent sheet (B). Example ² except that 2 g of the superabsorbent polymer (B) was used as the polymer 2c and 0.5 g (basis weight of about 38 g / m ² ) of the superabsorbent polymer (C) was used. In the same way as 5,
A sanitary napkin (comparative product 1) was prepared using the configuration shown in FIG.

Comparative Example 5 An absorbent of a commercial product (trade name: Free Day, manufactured by Kao Corporation) was taken out and used as an absorbent. Thereafter, a sanitary napkin (Comparative Product 1) was prepared in the same manner as in Example 1. It was created.

[Comparative Example 6] An absorbent of a commercially available ultra-thin napkin (trade name: Free Day Safety Slim Regular, manufactured by Kao Corporation) was taken out and used as an absorbent. Napkin (comparative product 1) was prepared.

Further, the centrifugal retention capacity of the absorber used in the present example and the comparative example after equilibrium absorption of the pseudo blood and the blood permeation rate of the absorber were measured as follows. [Table 3]
Shown in

[0113]

[Table 3]

<Measurement of the centrifugal retention capacity of the absorber> The absorber 2 used in the examples and comparative examples was formed into a bag of paper and nonwoven fabric so that the polymer did not fall off, and then placed in the bag. It was placed in a vat containing 1000 ml of blood and left as it was for 30 minutes. After that, in a bag-like state, a centrifugal separator (H-130C, manufactured by Domestic Centrifuge Co., Ltd.) was used.
The sample was rotated at a rotation number of min (centrifugal acceleration of 895 G) for 10 minutes, and then the weight was measured. The centrifugal retention capacity after centrifugation was determined by the equation shown in [Equation 5] below.

[0115]

(Equation 5)

<Measurement of Blood Permeation Rate of Absorber> Apparatus 51 shown in FIG. 8 [cross-sectional area: 10 cm ² , inner diameter: 35.8 mm, length: 5
An absorber sample 50 in which the central portion of the absorber was cut into a circle having a diameter of 60 mm was sandwiched between a glass cylinder of 00 mm (cylindrical portion) and a burette having a wire mesh of 80 mesh so that the absorber did not fall off. Absorbent is equilibrated and swelled using pseudo blood of (1). (Leave for about 30 minutes). Next, set the liquid level to 2
The cock was adjusted to 00 mm, the cock was opened again, and the time required for the pseudo blood to pass between the marked lines LM (liquid volume 100 ml) shown in the figure was obtained, and the permeation rate of the liquid was obtained by the following equation (Formula 6).

[0117]

(Equation 6)

Further, the sanitary napkins obtained in the examples and comparative examples were evaluated for performance with a focus on the absorption performance when a large amount of blood was absorbed, assuming that the sanitary napkin was worn for a long time during high excretion. That is, in order to observe the absorption performance at the time of high absorption of the products 1 to 5 of the present invention in Examples 1 to 5 and the comparative products 1 to 6 of Comparative Examples 1 to 6, the absorption time at the time of high absorption by the method shown below, A dynamic liquid return amount and a leak test were performed on each sanitary napkin, and the results are shown in Table 4 below.

[0119]

[Table 4]

(1) Absorption time (5 g), reabsorption time (1
0 g), re-reabsorption time (15 g), and measurement of dynamic liquid return amount As shown in FIG. 9, the sanitary napkins 80 obtained in Examples and Comparative Examples were placed horizontally and provided with an inlet 81 having a diameter of 10 mm. The acrylic plate 82 is placed. A weight 83 is further placed on the sanitary napkin 80 for testing so that a load of 5 g / cm ² is applied. 5 g of defibrillated horse blood (manufactured by Japan Biotest Laboratory Co., Ltd.) is injected through the inlet, and the absorption time (second) until the liquid is completely absorbed is determined. After the solution was completely absorbed, the solution was allowed to stand for 20 minutes, 5 g of defibrillated horse blood was injected again, the reabsorption time (10 g) was determined, and the solution was similarly allowed to stand for 20 minutes. Further, 5 g of defibrillated horse blood was injected, and the re-absorption time (15 g) was determined. Similarly, after the blood was completely absorbed, the blood was allowed to stand for 20 minutes.

Thereafter, an absorbent made of softwood pulp having a basis weight of 30 g / m ² cut to a width of 75 mm × 195 mm was used.
Sheets, upper surface of sanitary napkin 80 for test (skin contact surface side)
After wearing shorts with a sanitary napkin 80 attached to the movable female waist model 90 shown in FIG. 10 as shown in FIG. 11, the walking speed is 100 steps / min (50 m / min) for 1 minute. Walked.

After the walking, the sanitary napkin 80 and ten absorbers were taken out, and the weight of the defibrillated horse blood absorbed by the absorber was determined as a liquid return amount (g). The measurement was carried out for each of the five points, and the respective average values were determined, and the results were taken as the absorption time, re-absorption time, re-re-absorption time, and dynamic liquid return amount.

(2) Leak test (number of occurrences of leak) Sanitary napkin 8 for test obtained in Examples and Comparative Examples
11 is attached to the movable female waist model 90 as shown in FIG. 11 and shorts are applied.
(m / min) at a walking speed of 10 minutes. Thereafter, 5 g of the defibrillated horse blood was injected while walking through a tube, and then the same speed was allowed to walk for 20 minutes.
After injecting 5 g of defibrillated horse blood, it is allowed to walk for 20 minutes. Further, 5 g of defibrillated horse blood is injected, and the walking is repeated for 20 minutes.
At each time point, the number of leaked sheets out of the 10 samples was counted.

Considering the absorption time and the dynamic liquid return amount in the results shown in Table 4, the product of the present invention shows that the absorption time, the re-absorption time of repeated absorption and the re-re-absorption time are also 8 to 28 seconds. The liquid return amount is 0.1 to 0.3, and good results are obtained for both. On the other hand, comparative products have relatively good re-absorption times of 21 seconds and 28 seconds. Has a liquid return amount of 2.8 g and 3.0 g, which is inferior to that of the comparative product, indicating that both the absorption time and the liquid return amount cannot be satisfied.

Regarding the next number of leaks, particularly when the amount of absorption was 15 g assuming a long wearing time and a large amount of excretion,
The product of the present invention is excellent with a small number of leaks of 0 to 3 times, whereas the sample of the comparative product is 10 samples and is leaking, which is inferior. That is, the sanitary napkin of the present invention has a high blood retention capacity and, because it is composed of an absorber having both a high permeation rate, has an excellent reabsorption rate, and particularly, even during high excretion, It can be seen that this is a highly absorbent sanitary napkin with a small amount of liquid return and little leakage.

The present invention is not limited to the above-described embodiment, but can be variously modified without departing from the gist of the present invention.

[0127]

The sanitary napkin of the present invention suppresses the amount of liquid return and leakage even when worn for a long time and under extremely large amounts of excretion, which could not be achieved with conventional sanitary napkins. It is extremely absorbent and highly comfortable.

That is, since the sanitary napkin of the present invention has an absorber having both a high blood holding capacity and a high permeation rate, the sanitary napkin is excellent in the absorption rate and the reabsorption rate, and in particular, has a high excretion rate. Even at the time of the amount, the amount of the liquid returned is small and the leakage is small, so that the user can use it comfortably.

Further, since the sanitary napkin of the present invention has both a high blood permeation rate and a high blood holding capacity in the absorber, the polymer does not gel-block even during repeated excretion, and the blood is smoothened. To a polymer, and a large amount of blood can be completely solidified with the polymer.
Most blood can be fixed securely with polymer, and it has low leakage. More specifically, in the case where an absorbent is constituted by combining a specific high-absorbency polymer with high absorption and high permeability and a specific absorption sheet, the above-described present invention can be more reliably and effectively performed. A sanitary napkin that produces an effect can be made.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view showing a cross section in the width direction of an example of the sanitary napkin of the present invention.

FIG. 2 is a cross-sectional view (corresponding to FIG. 1) showing another example of the sanitary napkin of the present invention.

FIG. 3 is a sectional view (corresponding to FIG. 1) showing still another example of the sanitary napkin of the present invention.

FIG. 4 is a schematic diagram showing an apparatus for measuring the transmission speed of simulated blood.

FIG. 5 is a schematic diagram showing an apparatus for measuring the creme absorption height of an absorbent sheet.

FIG. 6 is a schematic diagram showing an apparatus for measuring a liquid permeation speed of an absorbent sheet.

FIG. 7 is a partially enlarged schematic view of a surface material used in Example 1.

FIG. 8 is a schematic view showing an apparatus for measuring the transmission speed of pseudo blood through an absorber.

FIG. 9 is a schematic sectional view showing an outline of measurement of absorption time.

FIG. 10 is a schematic diagram showing a movable female waist model.

FIG. 11 is a schematic diagram showing a state in which a sanitary napkin is attached to the crotch of the movable female waist model shown in FIG. 10;

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int.Cl. ⁶ , DB name) A61F 13/15

Claims (8)

(57) [Claims] 1. A sanitary napkin having a liquid-permeable surface material, a liquid-retentive absorbent, and a liquid-impermeable leakproof material, the absorbent comprising: a) the pseudo-blood after the equilibrium absorption and swelling of the simulated blood The centrifugal holding capacity is
30 g or more; b) The absorber is a cylinder having a cross-sectional area of 10 cm ²
A sanitary napkin, which is fixed to φ) with a thickness of 0.5 to 5 mm, equilibrated and swelled with pseudo-blood, and has a permeation speed of 50 ml / min or more when permeating pseudo-blood thereafter. 2. The absorbent has a superabsorbent polymer, and the superabsorbent polymer has the following properties: a) a centrifugal retention capacity after equilibrium absorption and swelling of simulated blood is 20;
g / g or more; b) 0.05 g of the above superabsorbent polymer has a cross-sectional area of 0.78
^2. A sanitary device according to claim 1, wherein the blood is introduced into a 5 cm ² cylinder (circle diameter: 10 mmφ), swelled by pseudo-blood, and then the permeation speed when permeating pseudo-blood is 1 ml / min or more. napkin. 3. The amorphous polymer according to claim 2, wherein the degree of irregularity P of the superabsorbent polymer is at least 1.2.
The sanitary napkin as described. 4. The method of claim amount of the superabsorbent polymer, and sprayed basis weight 20 to 80 weight percent of the total said absorber characterized in that it is a 100 to 500 g / m ² 2 The sanitary napkin as described. 5. The absorber according to claim 1, wherein at least a part thereof is:
The bulky cellulose fiber comprises a bulky cellulose fiber and a superabsorbent polymer. A) The fiber cross-sectional area is 3.0 × 10 ⁻⁶ cm ² or more and the roundness of the cross section is 0.5 or more. B) the cross-sectional area of the fiber is 5.0 × 10 ⁻⁶ cm ² or more; or c) the fiber has a three-dimensional shape. For napkins. 6. The absorbent body is provided with a highly permeable absorbent sheet on the uppermost layer thereof, the absorbent sheet comprising: a) bulky cellulose fiber, 50 to 98 parts by weight; An absorbent sheet obtained by mixing and making 2 to 30 parts by weight of a conductive adhesive fiber, and having a Klemm absorption height of 20 to 80 mm after 1 minute with respect to physiological saline, and
The Krem absorption height after 0 minute is 30 to 100 mm, and the permeation time of 10 g of 85% by weight glycerin aqueous solution is 50 minutes.
The sanitary napkin according to any one of claims 1 to 5, wherein the time is not more than seconds. 7. The absorber has a high-permeability absorbent sheet provided on the uppermost layer and a high-diffusion, high-permeability absorbent sheet and a high-absorbent polymer provided on the lower layer side thereof. The above-mentioned highly diffusive and highly permeable absorbent sheet comprises: a) bulky cellulose fibers, 20 to 80 parts by weight; b) hydrophilic fine fibers, 80 to 20 parts by weight; c) hot melting An absorbent sheet obtained by mixing papermaking with a non-adhesive fiber and 0 to 30 parts by weight.
7. The sanitary napkin according to claim 1, wherein the Klemm absorption height after one minute is 100 mm or more, and the permeation time of 10 g of an 85% by weight aqueous glycerin solution is 100 seconds or less. 8. The above bulky cellulose fiber is obtained by further crosslinking a mercerized pulp having a fiber cross-sectional area of 3.0 × 10 ⁻⁶ cm ² or more and a roundness of cross-section of 0.5 or more. The sanitary napkin according to claim 5, comprising pulp crosslinked with an agent.