JP2702852B2 - Absorbent articles - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an absorbent article represented by a sanitary napkin, a disposable diaper and a pad for incontinent persons.
By using a specific absorbent sheet and a high-absorbent polymer, it relates to a highly absorbent absorbent article with improved body fluid absorption properties, especially diffusion, liquid return from the absorber and leakage prevention. is there.

[0002]

2. Description of the Related Art Conventionally, many proposals have been made for absorbent articles aimed at improving the absorbability of bodily fluids, and many improvements have been made. Most of these improvements were to improve the absorption rate, prevent the liquid from returning from the absorber to the surface, prevent leakage, and reduce stickiness to the body.

[0003] For example, regarding the material of the absorber, the liquid is replaced with a hydrophilic absorbent paper or pulp that absorbs and retains the liquid in a physical fine space, and the liquid is subjected to a physicochemical action, that is, It has been proposed to improve absorption capacity and prevent liquid return after regulation by absorbing and retaining a liquid in a highly absorbent polymer using ion osmotic pressure. According to this proposal, the absorbency has been improved, and at present, an absorbent using both pulp and a superabsorbent polymer is used for most absorbent articles.

However, even with these absorbent articles,
It is still not enough to prevent leakage. And this fact is suggested by the fact that the first complaint about the absorbent article is leakage. In other words, a superabsorbent polymer of the type that absorbs and retains liquid by ionic osmotic pressure has a limit on the absorption rate of bodily fluids, and furthermore, cannot absorb bodily fluids unless the superabsorbent polymer is wetted by bodily fluids. And pulp having a high water absorption rate.

However, pulp is poor in diffusivity for efficiently using the entire absorber because the pulp absorbs blood in a spot form when a flexible fluff absorption layer is formed as the absorber. In addition, pulp exhibits a certain degree of compressive and bending recovery when dry, but exhibits extremely low strength when wet, and hardly exhibits such recovery, so that when stress is applied to wet pulp, pulp undergoes compressive deformation. (Hereinafter, referred to as “sleaking”), the absorption space is significantly reduced, and the bodily fluid once absorbed easily returns with the slant. Because the decrease in pulp fiber space due to this twist leads to an increase in the movement resistance of bodily fluids to the polymer, not only decreases the absorption efficiency of the polymer, but also the resorbing speed of the absorber as a whole after the twist is significantly reduced. , Which often leads to leaks.

[0006] In order to improve the diffusibility of these fluff pulp, the technology of improving the diffusivity by compressing / densifying the pulp has been reported so far. In addition, the distance between the fibers of the pulp becomes too close, and the resistance of the bodily fluid to the polymer becomes extremely large, which results in a decrease in the absorption efficiency of the polymer. There is an inconvenience. Also, in order to prevent twisting, wet paper made of natural pulp or the like in a wet process, wrapping the pulp and the absorbent body made of a highly absorbent polymer and integrating them, fixing them with waterproof paper, etc. to prevent twisting Attempts have been made. By this attempt, the twist can be slightly prevented, but not only the pulp twist cannot be prevented, but also wet paper made of ordinary natural pulp can be used in the dehydration / wet pressure / drying process during paper making. When the water is dewatered / dried, a very strong clamping pressure acts between the pulp fibers due to hydrogen bonding. Due to the tightening pressure due to the hydrogen bond, the pulp fibers are very tightly tightened, and the wet paper made from the pulp fibers is very slow in liquid absorption / permeation. In other words, even if the absorbent is wrapped and integrated with wet paper made of pulp and twisting is prevented, the absorption rate of the absorbent is adversely deteriorated, and as a result, the absorbent polymer leaks before absorbing the liquid. It has the disadvantage that

As disclosed in JP-A-56-60555 and JP-A-56-6096, the diffusivity of rayon spunbond or the like is formed on the upper surface or both surfaces of an absorbent sheet made of fluff pulp and a water-absorbing polymer. A technique for improving the diffusivity by laminating the above sheets is disclosed. Even in this absorber, basically, the fluff pulp and the water-absorbing polymer are combined in combination.
The pulp twist and the decrease in the distance between the pulp fibers due to the twist are not improved.

Japanese Patent Application Laid-Open No. 54-158096 discloses a technique of sandwiching an absorbent polymer between cellulosic nonwoven fabrics such as rayon spunbond. In this technique, since fluff pulp is not used, the diffusibility and the absorption efficiency of the polymer tend to be improved to some extent but are not at a satisfactory level. Why
Et permeability showing the liquid transfer resistance diffusivity and polymers of blood nonwoven absorbent sheet composed of a single fiber, since it is in inverse relationship. The liquid diffusivity tends to improve when the fiber diameter is reduced, but conversely, the liquid permeability deteriorates because the inter-fiber distance decreases. Conversely, when the fiber diameter is increased, the permeability is improved, but the diffusivity is inferior.

In other words, achieving both diffusibility and permeability is a contradictory phenomenon, and it is necessary to satisfy both of them, to obtain an absorbent article having high diffusivity and high permeability, and having extremely high absorption efficiency of the absorbent polymer. It was strongly desired.

[0010] Accordingly, an object of the present invention is to use a highly diffusive and highly permeable absorbent sheet as a part of the absorbent to maximize the effect of the superabsorbent polymer, to return the liquid from the absorbent, An object of the present invention is to provide an absorbent article which can reduce stickiness and leakage extremely and can be used comfortably by a user.

[0011]

SUMMARY OF THE INVENTION The present invention relates to a substantially vertically absorbent article having a liquid-permeable surface material, a liquid-retentive absorber, and a liquid-impermeable leakproof material. The body comprises, at least in part, a highly diffusing, highly permeable absorbing sheet and a highly absorbing polymer, wherein the highly diffusing, highly permeable absorbing sheet comprises: (a) bulky hydrophilic fibers; Part (b) hydrophilic fine fiber; 80 to 20 parts by weight (c) hot-melt adhesive fiber;
The object has been attained by providing the absorbent article according to claim 1, wherein the absorbent article has a thickness of 0.3 to 2.0 mm under ^two loads.

The absorbent of the absorbent article of the present invention uses the above-mentioned highly diffusive and highly permeable absorbent sheet (hereinafter sometimes simply referred to as “absorbent sheet”) as at least a part thereof. In order to obtain such an absorbent sheet, it is very important to control the spatial structure of the absorbent sheet. This is because, in the conventional absorbent paper mainly containing pulp fibers, as described above, strong hydrogen bonding acts between pulp fibers during wet papermaking, the pulp fibers become too dense, the bulkiness is very poor, and liquid Is also very poor. Further, as a method for producing a bulky absorbent sheet, it is conceivable that pulp or the like is bulky laminated by a dry method such as an air lay method and bonded to the pulp using an appropriate binder. Certainly, according to this method, it is possible to obtain an absorbent sheet having a very low density, a bulkiness, and a high degree of permeability, but poor diffusibility due to a large distance between pulp fibers. In other words, in order to obtain the absorbent sheet, it is necessary to control the tightening force due to hydrogen bonding during wet papermaking, and to create a bulky absorbent sheet while absorbing the seemingly contradictory properties of diffusivity and liquid permeability. How to control the spatial structure of the flexible sheet is a very important technology.

Next, the bulky hydrophilic fibers constituting the absorbent sheet of the absorbent will be described. As the bulky hydrophilic fiber, the three-dimensional structure of the fiber is bulky, that is, has a crimped structure, is bent, is branched, or has a cross-sectional area of 3.0.
× 10 ⁻⁶ cm ² or more and the cross-section circularity is 0.5 or more, or the fiber cross-sectional area is 5.0 × 1 regardless of the cross-section circularity
If 0 ^-6 cm ³ or more, can be used in any of the hydrophilic fibers. For example, pulp, cotton, cellulose fibers typified by rayon, etc., acrylonitrile, hydrophilic synthetic fibers such as polyvinyl alcohol, and the like, among these, one type may be used alone, or a mixture of several types may be used. May be. Above all, mercerized pulp obtained by mercerizing pulp fibers having a crimp structure and regenerated cellulose fibers or pulp fibers capable of freely controlling the fiber cross-sectional area and cross-sectional shape and swelling / enlarging the fiber cross-section is relatively inexpensive and easy. And can be preferably used.

[0014] Here, the control of the tightening force due to hydrogen bonding between the fibers during wet papermaking can be achieved by controlling whether the fiber structure has a three-dimensional structure or by controlling the cross-sectional area and cross-sectional shape of the fiber. It turned out to be. The mixing ratio of the bulky hydrophilic fiber to the whole wet nonwoven fabric is 20
The amount is preferably from 80 to 80 parts by weight, more preferably from 30 to 70 parts by weight. If the bulky hydrophilicity is less than 20 parts by weight, the intended bulky absorbent sheet cannot be obtained, and if it exceeds 80 parts by weight, the diffusibility becomes poor.

Next, the hydrophilic fine fibers constituting the absorbent sheet of the absorbent will be described. As the hydrophilic fine fiber, a fiber having a hydrophilic fiber surface and a large surface area, preferably having a cross-sectional area of 2.0 × 10 ⁻⁶ cm ²
Is less than or equal to and the roundness of the cross section is less than 0.5,
Alternatively, a hydrophilic fiber having a fiber surface area of 1.0 m ² / g or more is used. Such fibers include, for example, cellulose fibers typified by pulp, cotton, rayon and the like, and acrylonitrile, hydrophilic synthetic fibers such as polyvinyl alcohol and the like, and among these, only one type may be used, or several types may be used. You may mix and use. Above all, pulp fibers can be preferably used because they are very inexpensive and the fiber surface area can be controlled by beating conditions. For example, finely beaten kraft pulp NBKP (trade name; SKEENA PRIME, Skeena Cellulose Co.) and LBKP (trade name; PRINCE AL)
BERT ASPEN HARDWOOD, Wafer Weather Paper Co., Ltd.) and straw pulp.

The mixing ratio of the hydrophilic fine fibers to the whole wet nonwoven fabric is 20 to 80 parts by weight, but 30 to 70 parts by weight.
Parts by weight are preferred. If the mixing ratio is less than 20 parts by weight, the desired diffusivity cannot be obtained. Conversely, if it exceeds 80 parts by weight, the inter-fiber distance becomes too dense and the permeability deteriorates. In addition, for the purpose of stabilizing the spatial structure of the absorbent sheet, the hot melt adhesive fibers are mixed during wet papermaking, so that the spatial structure can be stably maintained even when wet, so that it can be preferably used.

Next, the heat-fusible adhesive fiber constituting the absorbent sheet of the absorbent body will be described. As the above-mentioned heat-fusible adhesive fibers, fibers that are melted by heating and bonded 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 wet nonwoven fabric is 0%.
30 parts by weight, preferably 0 to 20 wt parts der
And more preferably 2 to 20 parts by weight . Mixing ratio is 30
If the amount exceeds the weight part, the absorbency and the diffusivity of the absorbent sheet decrease, which is not preferable.

Next, the bulkiness of the absorbent sheet of the absorber will be described. The absorbent sheet obtained by mixing and mixing the fibers having the above composition has a load of 2.5 g / cm ² under a load of 2.5 g / cm ² .
It is 0.3 to 2.0 mm, preferably 0.3 to 1.0 mm. When the thickness of the absorbent sheet under a load of 2.5 g / m ² is less than 0.3 mm, the space for temporarily holding the liquid and the amount of liquid to be diffused are small, and the absorption efficiency of the absorbent sheet, especially the superabsorbent polymer, is reduced. Cannot be sufficiently exhibited, and conversely, the thickness is 2.
If it exceeds 0 mm, the space for holding the liquid becomes too large,
This is because it is difficult to smoothly transfer the liquid to the lower layer, particularly to the superabsorbent polymer. An absorbent sheet having a Klemm absorption height of 1 mm or more with respect to a physiological saline solution of 50 mm or more and a Klemm absorption height of 10 mm or more after 10 minutes is preferable, and more preferably a Klem absorption height of 1 minute or more with respect to a physiological saline solution. The height is 60 mm and the creme absorption height after 10 minutes is 120 mm or more. Also, regarding the absorption and diffusion properties,
If the Klemm absorption height after 1 minute with respect to physiological saline is less than 50 mm, or the Krem absorption height after 10 minutes is less than 10 mm, the absorption and diffusion capacity of the absorbent sheet is insufficient, and the absorption of the highly absorbent polymer This is because the efficiency becomes poor.

Hereinafter, another configuration of the absorber of the present invention will be described. The absorbent sheet constituting the absorbent article of the present invention is required to be used together with a superabsorbent polymer. However, in order to make it work more effectively, the absorbent sheet is used so as to be in contact with the superabsorbent polymer. In particular, by sandwiching a superabsorbent polymer between the absorbent sheets, it is possible to obtain an absorbent polymer sheet having extremely high absorption and high retention, so that it can be more preferably used. In order to achieve smoother liquid transfer to the superabsorbent polymer, it is preferable that the absorbent sheet has higher permeability to the lower layer. Specifically, a 10% aqueous solution of 85% glycerin is used.
g (measurement method described later in Examples) is 1
It is preferably not more than 00 seconds. If the passage time is longer than 100 seconds, it is difficult to transfer the liquid to the superabsorbent polymer, which is not preferable.

The absorbent sheet used in the present invention is prepared by mixing the above-mentioned bulky hydrophilic fibers and hydrophilic fine fibers at a specific mixing ratio so that the area having a large space diameter related to permeability can be obtained. The space diameter structure / distribution in one absorbent sheet can be controlled up to the area with a small space diameter in order to increase the surface area related to the diffusivity, and absorption that has both seemingly contradictory characteristics of liquid permeability and liquid diffusivity It was possible to obtain a functional sheet.

The spatial diameter distribution of the absorbent sheet can be measured by a mercury porosimeter. As a preferable space diameter distribution, a total pore surface area is 1.0 cm ² in a space diameter distribution measurement of a space diameter of 0.003 to 200 μm.
/ G or more, and a space diameter of 10 to 2 which is greatly related to permeability.
The pore surface area in the area of 00 μm is 18 to 3 of the total pore surface area.
5% is preferable, and the space diameter which is greatly related to the diffusivity is 0.1%.
The pore surface area in the 003 to 1 μm region is 50% of the total pore surface area.
It is preferably about 80%. More preferably, the total pore surface area is at least 1.3 m ² / g and the space diameter is 10 to 2
The pore surface area in the 00 μm region is 20 to 30 of the total pore surface area.
% Is more preferable, and the surface area of the region having a space diameter of 0.003 to 1 μm is more preferably 50 to 70%.

The total pore surface area of the absorbent sheet is 1.0 m ²
If the ratio is less than 50% / g, or if the ratio of the pore surface area having a space diameter of 0.003 to 1 μm is less than 50%, the desired diffusibility cannot be obtained sufficiently, which is not preferable. Too much, resulting in insufficient permeability.
If the ratio of the pore surface area in the space diameter of 10 to 200 μm is less than 18 %, the desired permeability cannot be obtained sufficiently, and if it exceeds 35%, the diffusivity becomes insufficient.

The preferred basis weight of the absorbent sheet is 10 to 200 g / m ² , more preferably 20 g / m ^2.
１００100 g / m ² . Further, the absorbent sheet,
Only one sheet may be used, or several sheets may be stacked. When the superabsorbent polymer is sandwiched between the above absorbent sheets, the amount of the superabsorbent polymer is determined by the total absorbent polymer sheet weight (weight of the absorbent sheet + weight of the superabsorbent polymer, such as hot melt or binder). If the superabsorbent polymer is immobilized by the method, the weight is included).
The amount is preferably 0 to 80 parts by weight, more preferably 20 to 70 parts by weight. If the amount of the superabsorbent polymer is less than 10 parts by weight, the absolute amount for fixing the liquid is reduced, which is not preferable. Conversely, if it exceeds 80 parts by weight, the superabsorbent polymer causes gel blocking in the polymer layer when absorbing the liquid. This is because it is undesired.

In order to make the absorbent sheet and the superabsorbent polymer constituting the absorbent article of the present invention more effectively act, the uppermost layer of the absorbent (the non-skin contact surface side of the liquid-permeable surface material) Layer), an extremely permeable bulky sheet is used for the layer, and the absorbent sheet or the superabsorbent polymer sheet sandwiching the superabsorbent polymer is laminated on the lower layer to constitute a bodily fluid that has passed through the surface material. Is absorbed very quickly by the absorber and then spread over the superabsorbent polymer by the diffusible absorbent sheet, so that the bodily fluid can be transferred to the superabsorbent polymer more smoothly. An absorptive article which has high absorption, does not leak, and can be used comfortably by the user is obtained, and can be more preferably used.

As the bulky sheet having extremely high permeability, the following sheet is preferably used. a) bulky hydrophilic fiber; 30 to 98 parts by weight b) hot-melt adhesive fiber; 2 to 30 parts by weight
/ Cm ² under load, having a thickness of 0.3 to 2.0 mm, and having a Klemm absorption height of 20 minutes after 1 minute in physiological saline.
~ 80mm, and Krem absorption height after 10 minutes is 30 ~ 10
The sheet is characterized in that it has a thickness of 0 mm and a passage time of 10 g of an 85% by weight aqueous solution of glycerin of 10 g to 10 seconds. As described above, a bulky hydrophilic fiber and a hydrophilic fine fiber are mixed at a specific mixing ratio, and the spatial structure of one bulky sheet is controlled, whereby a very high diffusion and high permeability bulky sheet is obtained. Could be obtained. Also, the present invention
The above-mentioned absorbent sheet may be used as at least a part of the absorbent article, and another sheet or a constituent member may be arranged above and below the absorbent sheet. Furthermore,
The absorbent sheet may be formed by mixing at least the bulky hydrophilic fiber, hydrophilic fine fiber and hot-melt adhesive fiber at the above-mentioned specific ratio, and other component fibers may be mixed. It may be.

[0026]

According to the absorbent article of the present invention, the bodily fluid on the side of the surface material penetrates the surface material and is absorbed by the absorber. The body fluid is spread over the entire superabsorbent polymer, and the fluid is smoothly transferred to the superabsorbent polymer, so that the bodily fluid is contained very effectively in the absorber. The absorbent article of the present invention, by using this absorbent sheet together with a super absorbent polymer, maximizes the absorption efficiency of the super absorbent polymer,
Since the liquid retaining property is extremely high, there is no liquid return to the surface, and it is possible to provide an absorbent article with extremely high absorption and no leakage. Furthermore, by forming an absorbent body in combination with a specific extremely permeable and bulky absorbent sheet, compared to conventional absorbent articles, it is extremely thin, has less leakage and has improved fit to the body. Therefore, a more comfortable use feeling is given to the user.

[0027]

EXAMPLES Next, the absorbent part of the present invention will be specifically described based on the following examples. In the following examples, sanitary napkins will be described as an example, but the present invention can be similarly applied to paper diapers and the like. As shown in FIG. 3, the embodiment of the present invention basically includes a liquid-permeable surface material 1, a liquid-retentive absorber 2, and a liquid-impermeable leakproof material 3.
In the absorbent article having
Has a high diffusion high permeability absorbent sheet (absorbent sheet) 2A
And superabsorbent polymer 2B.

First, the absorptive sheet, the absorptive holding sheet and the topsheet used in the present example and comparative example were manufactured in the following manner, and their functions were measured. Absorbent sheet 2
As A, the following absorbent sheets (A) to (G) were prepared. [Absorptive sheet (A)] Pulp having a crimp structure as a bulky hydrophilic fiber (trade name: High Bulk Additi)
ve (hereinafter referred to as HBA), 40 parts by weight of Wafer Paper Co., Ltd., as hydrophilic fine fibers, a fiber cross-sectional area of 1.9 × 10 ⁻⁶ cm ² , and a roundness of fiber cross-section of 0.32
Kraft pulp NBKP (trade name; SKEENA PRIM
E, Skeena Cellulose Co.) Polyethylene terephthalate (hereinafter referred to as PET) having a thickness of 1.1 denier and a length of 5 mm as a hot-melt adhesive fiber (trade name;
10 parts by weight of TMOTNSB (Teijin Co., Ltd.) were dispersed in water, and these were paper-formed and dried to obtain an absorbent sheet (A) having a basis weight of 40 g / m ² . At the time of papermaking, crepe was set to 10% in the absorbent sheet.

[Absorbent sheet (B)] Bulk hydrophilic fiber
As fiber, fiber cross-sectional area is 3.8 × 10^-6cm^TwoAnd fiber
Mercerized pulp whose cross-section circularity is 0.80 (trade name;
Porosenia-J, ITT RAYONIER INC.) 60 parts by weight, hydrophilic
Fiber cross-sectional area is 1.9 × 10^-6c
m ^TwoKraft pal with a roundness of 0.32
NBKP (trade name; SKEENA PRIME, Skeena Cellulose)
 Co.) 40 parts by weight were dispersed in water.
After drying on paper, basis weight 40 g / m^TwoAbsorbent sheet B
Obtained. At the time of papermaking, crepe was added to the absorbent sheet at 10%.
Set.

[Absorbent sheet (C)] As bulky hydrophilic fibers, the fiber cross-sectional area is 5.9 × 10 ⁻⁶ cm ² , the roundness of the fiber cross section is 0.68, and the length is 7 mm. Rayon (trade name: Corona SB Rayon, Daiwa Bow Rayon Co., Ltd.)
10 parts by weight and a fiber cross-sectional area of 3.8 × 10 ⁻⁶ cm ² ,
40 parts by weight of mercerized pulp having a roundness of 0.80 (trade name: POROSENIA-J, ITT RAYONIER INC.), As hydrophilic fine fibers, fiber cross-sectional area of 1.9 × 10 ⁻⁶ cm ² , fiber Kraft pulp NBK whose cross-section circularity is 0.32
P (trade name; SKEENA PRIME, Skeena Cellulose Co.) 4
5 parts by weight, 5 parts by weight of polyvinyl alcohol (trade name: Fibribond, Sansho Co., Ltd.) as hot-melt adhesive fibers were dispersed in water, and these were made and dried.
An absorbent sheet (C) having a basis weight of 40 g / m ² was obtained. At the time of papermaking, crepe was set to 10% in the absorbent sheet.

[Absorbent sheet (D)] As a bulky hydrophilic fiber, the fiber cross-sectional area is 5.9 × 10 ^-6 cm ² , the roundness of the fiber cross-section is 0.68, and the length is 7 mm. Rayon (trade name: Corona SB Rayon, Daiwa Bow Rayon Co., Ltd.)
Kraft pulp NBKP (trade name: SKEENA PRIME, Sk) having a fiber cross-sectional area of 1.9 × 10 ⁻⁶ cm ² and a roundness of the fiber cross-section of 0.32 as a hydrophilic fine fiber as 80 parts by weight.
eena Cellulose Co.), 10 parts by weight of polyvinyl alcohol (trade name: Fibribond, Sansho Co., Ltd.) as hot-melt adhesive fiber, dispersed in water, paper-making and drying, and basis weight An absorbent sheet D of 40 g / m ² was obtained. At the time of papermaking, crepe was set to 10% in the absorbent sheet. In this absorbent sheet (D), the mixing ratio of the hydrophilic fine fibers was 10 parts by weight,
It deviates from the range of ２０20 parts by weight.

[Absorptive sheet (E)] Kraft pulp NBKP (trade name; SKEENA PRIME, trade name) having a fiber cross-sectional area of 1.9 × 10 ^-6 cm ² and a roundness of the fiber cross-section of 0.32
After dispersing Skeena Cellulose Co.) in water, papermaking and drying, an absorbent sheet E having a basis weight of 40 g / m ² was obtained.
At the time of papermaking, crepe was set to 10% in the absorbent sheet. This absorbent sheet (E) is composed of only hydrophilic fine fibers (kraft pulp NBKP) and does not contain bulky hydrophilic fibers.

[Absorptive sheet (F)] A rayon staple (Diwabo 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. The spunbonded nonwoven fabric having a basis weight of 40 g / m ² was used as the absorbent sheet F. In the absorbent sheet (F), bulkiness of the hydrophilic fibers is not mixed.

[Absorptive sheet (G)] Basis weight 40 g / m ²
Dry Pulp Sheet (trade name; Kinocross, Honshu Paper Co., Ltd.) was used as the absorbent sheet G. In the absorbent sheet (G), the hydrophilic fine fibers and the bulky hydrophilic fibers were not mixed, and were not a wet nonwoven fabric.

Here, the cross-sectional area of the fiber is measured by vertically slicing the cross-section of the fiber so that the area does not change, and taking a cross-sectional photograph with an electron microscope. The cross-sectional area of the fiber cross section is measured by 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 using the following equation (1) using a cross-sectional photograph and an image analyzer in the same manner. An arbitrary fiber cross section was measured at 100 points, and the average value was defined as the roundness of the fiber cross section.

[0036]

(Equation 1)

Next, various absorption-retaining polymer sheets 2E shown in FIG. 4 were prepared. Hereinafter, the absorption-retaining polymer sheets (A) to (G) will be described. [Absorptive polymer sheet (A)] Absorbent sheet (A)
Hot melt topco P-618B (manufactured by Toyo Petrolite Co., Ltd.) in a spiral shape with a basis weight of 10 g / m ^2.
, And a polyacrylate superabsorbent polymer was further sprayed at a basis weight of 50 g / m ² . Further, the absorbent sheet A was overlaid to obtain an absorbent polymer sheet (A) in which the superabsorbent polymer 2B was sandwiched between the absorbent sheets 2A as shown in FIG.

[Absorption-Retaining Polymer Sheet (B) ~]
(G)] Using the absorbent sheets (B) to (G) in the same manner as the production of the absorbent and retaining polymer sheet (A) from the absorbent sheet (A), use the absorbent and retaining polymer sheets (B) to (G), respectively. (G) was obtained.

Next, the production of the topsheet 1 will be described. A topsheet (A) and a topsheet (B) were prepared as follows. [Surface sheet (A)] Dry heat of 25 g / m ² basis weight using polyethylene / polypropylene conjugate fiber (manufactured by Chisso Corporation) to which 0.34% by weight of a mixed surfactant of alkyl phosphate and sorbitan fatty acid ester has adhered. As shown in FIG. 5, a low-density polyethylene 21 (manufactured by Mitsui Petrochemical Co., Ltd.) was laminated on the non-woven fabric 22 by 25 μm as shown in FIG.
A surface sheet having a density of で² mm ² and a hole density of 52 / cm ² was obtained. This was designated as a topsheet (A).

[Surface Sheet (B)] A surface sheet (nonwoven fabric) of a commercially available sanitary napkin (trade name: Laurier, Kao Corporation) was used as a surface sheet (B). Next, in the absorbent sheets (A) to (G), the thickness under a load of 2.5 g / m ² , the Klemm absorption height after 1 minute and 10 minutes with respect to physiological saline, the passage time of glycerin 85 wt%, The pore surface area and the ratio of the pore surface area in the space diameter of 0.01 to 1 μm and the ratio of the pore surface area in the pore diameter of 10 to 20 μm are determined,
The results are shown in Table 1 below.

[0041]

[Table 1]

Here, each measurement item in Table 1 will be described. Thickness under a load of 2.5 g / cm ^{2 The} absorbent sheet was cut into a size of 50 × 50 cm to prepare a measurement piece, and a load area of 10 cm ² (radius 1
A load of 2.5 g / cm ² was applied with a 7.8 mm disk), and the thickness of the absorbent sheet was determined with a thickness gauge. An average of 10 times was obtained in total, and the value was defined as the thickness under a load of 2.5 g / cm ² .

Krem Absorbing 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 is hung so that there is no slack, and the upper and lower ends are 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 liquid passage time was measured using a measuring device shown in FIG. First, an absorptive sheet was cut into 50 mm in length and 50 mm in width to prepare a measurement piece 40. Then, as shown in FIG. 7, the measurement piece 40 was sandwiched and fixed from both upper and lower sides by glass tubes 41, 41 having an inner diameter of 35 mm. . At this time, the liquid is fixed from both sides with clips via the silicone rubber 42 so that the liquid does not seep out from the side during the measurement. 10 g of a 85% aqueous glycerin solution 43 prepared and mixed at the following ratio is taken as a measuring solution in a 10 ml beaker 44 and gently injected. Glycerin 85
After injecting the% 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 this was defined as the liquid passage time. The measurement solution (85% glycerin aqueous solution) was prepared as follows. After mixing 15 g of ion-exchanged water with 85 g of glycerin (Wako Pure Chemical Industries, Ltd.), Food Blue No. 1 (Tokyo Chemical Industry Co., Ltd.)
01 g was added, and the mixture was colored blue.

Total pore surface area, space diameter 0.01-1 μm
Of the pore surface area ratio and the pore surface area ratio at a space diameter of 10 to 200 μm The absorbent sheet is cut into a length of 10 mm and a width of 20 mm. 3 in total
Cut, mercury porosimeter (Shimadzu Corporation)
Set the sample cells so that they do not overlap each other,
The pore distribution in a space diameter of 0.003 μm to 200 μm was measured. The pore distribution curves (differential and integral curves) of the absorbent sheets (A) to (G) are shown in FIGS. Each figure 11
17 to 17, the total pore surface area over a space diameter of 0.003 to 200 μm is defined as the total pore surface area, and the space diameter is 0.003 to 1 μm and the space diameter is 10 to 200 μm, respectively.
The ratio of the total pore surface area to the total pore surface area at m was determined.

Example 1 As shown in FIG. 1, an absorption-retaining polymer sheet (A) was used as an absorption-retaining polymer sheet 2E having a length of 195 mm and a width of 75 mm.
Further, as a bulky hydrophilic fiber, the fiber cross section is 3.8 × 10 ⁻⁶ cm ² and the roundness of the fiber cross section is 0.80.
Mercerized pulp (trade name: Porose two Ah J, ITT RA
Y ONIER INC.) 70 parts by weight and fiber cross-sectional area is 5.9 ×
10 ^-6 cm ² roundness of the fiber cross section length 0.68 of 8mm rayon (trade name: Corona SB Rayon, Daiwabo Rayon Co.) 20 parts by weight, as the heat fusible bonding fibers,
5 parts by weight of polyvinyl alcohol (trade name: Fibribond, Sansho Co., Ltd.), and kraft pulp NBKP (trade name: SKEENAPRIME, Skeena Cekkukose C) as other components
O.) 10 parts by weight of each were dispersed in water, these were paper-formed, dried, and then cut into a bulky and highly permeable absorbent sheet (2C) made to a basis weight of 30 g / m ² to a length of 195 mm and a width of 170 mm. And an absorber. The bulky and highly permeable absorbent sheet had a thickness of 0.39 mm under a load of 2.5 g / cm ² and an absorption height of 35 mm after 1 minute with respect to physiological saline.
The absorbent sheet had an absorption height of 50 mm after 0 minute and a passage time of 10 g of an 85% aqueous glycerin solution of 25 seconds.
The resulting absorbent body 2 is made of polylaminate waterproof paper 3 (225 mm long,
Roll up at 95mm width), length 225mm, width 172mm
A sanitary napkin was prepared using the topsheet (A) as the topsheet 1 and the configuration shown in FIG. In FIG. 1, reference numeral 6 denotes a fixing adhesive, and reference numeral 5 denotes a release paper.

Example 2 The procedure of Example 1 was repeated, except that the absorption-retaining polymer sheet (B) was used instead of the absorption-retaining polymer sheet (A).
An absorbent was made in the same manner as in Example 1, and a sanitary napkin was made with the configuration shown in FIG.

Example 3 The procedure of Example 1 was repeated except that the absorption-retaining polymer sheet (C) was used instead of the absorption-retaining polymer sheet (A).
An absorbent was made in the same manner as in Example 1, and a sanitary napkin was made with the configuration shown in FIG.

Example 4 An absorbent was prepared in the same manner as in Example 1 except that the surface sheet (B) was used in place of the surface sheet (A) used in Example 1, and a physiological solution was constructed using the structure shown in FIG. Napkin was made.

Example 5 As shown in FIG. 2, an absorption / holding polymer sheet (A) was used as an absorption / holding polymer sheet 2E having a length of 195 mm and a width of 70 mm. 7-denier, 5 mm long SA rayon (Daiwabo Rayon Co., Ltd.) 75 parts, pulp 25 parts PVA
(Gothenol P-250) Absorbent sheet 2D having a basis weight of 25 g / m ² , obtained by blending / making 10 parts of paper, is cut into a length of 195 mm and a width of 75 mm. the absorbent paper of m ² (length 195 mm, width 170m
m), and integrated to obtain absorber 2. This absorber 2
A sanitary napkin was prepared by using a laminated paper 3 laminated with polyethylene, a surface material 1 using a topsheet A, and a slip-preventing tape 4 according to the configuration shown in FIG. In FIG. 2, reference numeral 6 denotes a fixing adhesive, and reference numeral 5 denotes a release paper.

Example 6 Except that the absorption-retaining polymer sheet (B) was used instead of the absorption-retaining polymer sheet (A) used in Example 5,
A sanitary napkin was prepared in the same manner as in Example 5 with the configuration shown in FIG.

COMPARATIVE EXAMPLE 1 The same procedure as in Example 1 was carried out except that the absorbent / retained polymer sheet (D) was used instead of the absorbent / retained polymer sheet (A) used in Example 1, and the sanitary sanitary structure was constructed as shown in FIG. Created a napkin.

COMPARATIVE EXAMPLE 2 The same procedure as in Example 1 was carried out except that the absorbent / retained polymer sheet (E) was used instead of the absorbent / retained polymer sheet (A) used in Example 1, and the sanitary sanitary tract was constructed using the structure shown in FIG. Created a napkin.

COMPARATIVE EXAMPLE 3 The same procedure as in Example 1 was carried out except that the absorbent / retained polymer sheet (F) was used instead of the absorbent / retained polymer sheet (A) used in Example 1, and the sanitary sanitary lining was constructed as shown in FIG. Created a napkin.

COMPARATIVE EXAMPLE 4 The same procedure as in Example 1 was repeated except that the absorbent and retaining polymer sheet (G) was used in place of the absorbent and retaining polymer sheet (A) used in Example 1, and the sanitary structure was used as shown in FIG. Created a napkin.

COMPARATIVE EXAMPLE 5 The same procedure as in Example 4 was carried out except that the absorption-retaining polymer sheet (E) was used instead of the absorption-retaining polymer sheet (A) used in Example 1, and the sanitary sanitary structure was constructed as shown in FIG. Created a napkin.

COMPARATIVE EXAMPLE 6 The same procedure as in Example 5 was carried out except that the absorbent / retained polymer sheet (F) was used instead of the absorbent / retained polymer sheet (A) used in Example 5, and the sanitary sanitary tract was constructed using the structure shown in FIG. Created a napkin.

COMPARATIVE EXAMPLE 7 The same procedure as in Example 5 was carried out except that the absorbent and retaining polymer sheet (G) was used in place of the absorbent and retaining polymer sheet (A) used in Example 5, and the sanitary sanitary structure was constructed as shown in FIG. Created a napkin. Next, in order to observe the absorption performance of the inventive products 1 to 6 in Examples 1 to 6 and the comparative products 1 to 7 in Comparative Examples 1 to 7, the absorption time was determined by the method described below.
A liquid spreading area, a dynamic liquid return amount, and a leak test were performed on each sanitary napkin, and the results are shown in Table 2 below.

[0059]

[Table 2]

(1) Absorption time and liquid spreading area (cm ² ) As shown in FIG. 8, the sanitary napkins 80 obtained in the examples and comparative examples were placed horizontally, and an acrylic having an inlet 81 having a diameter of 10 mm was provided. The plate 82 is placed. A further weight 83 is applied so that a load of 5 g / cm ² is applied to the sanitary napkin 80 for testing.
Put. 6 g of defibrillated horse blood (manufactured by Japan Biotest Laboratory Co., Ltd.) is injected from the inlet, and the absorption time (second) until the liquid is completely absorbed is determined. A total of 10 samples were measured, and the average blood was taken as the absorption time (second). Further, after the liquid was completely absorbed, the solution was left as it was for 20 minutes, and then the sanitary napkin was decomposed, and the blood spreading area (cm ² ) of the absorption-retaining polymer sheet was determined. A total of 10 samples were measured, and the average blood was used as the liquid spreading area.

(2) Dynamic liquid return amount As shown in FIG. 8, the test sanitary napkins 80 obtained in Examples and Comparative Examples were placed horizontally, and an acrylic plate provided with a 10 mm diameter injection port 81. Place 82. A weight 83 is further placed on the sanitary napkin 80 for testing so that a load of 5 g / cm ² is applied. 10 g of defibrillated horse blood (manufactured by Nippon Biotest Laboratory Co., Ltd.) is injected from the inlet 81, and is left for 20 minutes after the liquid is completely injected. Then 75
Ten pieces of absorbent paper having a basis weight of 30 g / m ² cut to a width of 195 mm and having a basis weight of 30 g / m ² were stacked on the upper surface (skin contact side) of the sanitary napkin 80 for testing, and a movable female waist model 90 shown in FIG.
Then, a sanitary napkin 80 on which absorbent paper was superimposed as shown in FIG. 10 was attached, shorts were spread, and then the subject was walked at a walking speed of 10 steps / min (50 m / min) for 1 minute. After walking, the sanitary napkin 80 and ten pieces of absorbent paper were taken out, and the weight of the defibrated horse blood absorbed by the absorbent paper was determined as a liquid return amount (g). The sanitary napkin 80 was measured at 10 points, and the average blood was used as the dynamic fluid return amount.

(3) Leak test Sanitary napkin 8 for test obtained in Examples and Comparative Examples
10 was attached to the movable female waist model 90 as shown in FIG. 10 and shorts were applied.
(m / min) at a walking speed of 10 minutes. Thereafter, 3 g of the defibrillated horse blood is passed through the tube 91 while walking.
Inject and then walk for 10 minutes at the same speed,
Then, after injecting 3 g of defibrillated horse blood, it was allowed to walk for 10 minutes, and then, injecting 3 g of defibrillated horse blood, and repeated walking for 10 minutes. At each time point, the number of leaked samples out of several tens of samples was counted. I counted.

Considering the absorption time and the liquid spreading area with respect to the results shown in Table 2, according to the product of the present invention, the absorption time is 13 to 22 seconds and the liquid spreading area is 73 to 85 cm ^2. In contrast to the results obtained, some comparative products have relatively good absorption times of 15, 17, and 18 seconds, but these have liquid spreading areas of 28,
It is inferior to 27 and 35 cm ² , and the comparative product cannot satisfy both the absorption time and the liquid spreading area. Next, the dynamic liquid return amount was 0.1% for the product of the present invention.
The comparative product is 0.7-
Obviously, it is inferior at 1.2 g. Also, regarding the number of leaks, when the liquid amount is 6 g or 9 g, the number of leaks is 0 to 3 times in the product of the present invention, which is small, and excellent, whereas the number of leaks is 4 to 10 times in the comparative product. Is inferior.

That is, since the absorbent article of the present invention has a composite of a highly absorbent polymer and a highly diffusive and highly permeable absorbent sheet, the absorption rate, the diffusivity, and the amount of blood returned (blood (Retainability), it is clear that the number of occurrences of leakage is very small and high absorbent performance is obtained. Furthermore, by constituting an absorbent body in combination with a specific extremely permeable and bulky absorbent sheet, the absorption that can provide a more comfortable feeling of use to the user is extremely thin, extremely absorbent and less leaky. It can be seen that the conductive article can be provided.

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. For example, as shown in FIG. 3, a member having another member 2F in addition to the highly diffusive and highly permeable absorbent sheet and the highly absorbent polymer may be used. In addition, the superabsorbent polymer is not limited to being sandwiched between two high diffusion high permeability absorbent sheets,
The sheet may be sandwiched by being wrapped by one sheet of high diffusion and high permeability absorption sheet.

[0066]

According to the absorbent article of the present invention, by using a highly diffusive and highly permeable absorbent sheet, the effect of the highly absorbent polymer is exerted to the maximum and liquid return from the absorbent, stickiness, and leakage are achieved. And an absorbent article that can be used comfortably by the user.

That is, the present invention uses a highly diffusive, highly permeable absorbent sheet and a highly absorbent polymer in which the spatial structure of a sheet having a specific composition is controlled for the absorber, so that the absorbent can be absorbed very effectively and quickly. In order to spread the body fluid throughout the body, smoothly transfer the body fluid to the superabsorbent polymer, and solidify the body fluid with the superabsorbent polymer, it is possible to provide an unprecedented highly absorbent and highly absorbent absorbent article. .

Further, by constituting an absorbent body in combination with a specific extremely permeable bulky absorbent sheet,
The bodily fluid that has passed through the topsheet is quickly absorbed by the bulky absorbent sheet, and the bodily fluid is more smoothly transmitted to the underlying high-diffusion and high-permeability absorbent sheet. After that, the blood is quickly spread over the entire absorbent body with a high-diffusion and high-permeability absorbent sheet, and the body fluid is passed by the high-absorbency polymer. It is possible to provide an extremely thin and compact absorbent article that can be idealized.

[Brief description of the drawings]

FIG. 1 is a lateral cross-sectional view of a sanitary napkin which is an embodiment of the absorbent article of the present invention and a comparative article.

FIG. 2 is a lateral sectional view of a sanitary napkin showing another embodiment and a comparative example of the present invention.

FIG. 3 is a lateral sectional view of a sanitary napkin showing still another example and a comparative example of the present invention.

FIG. 4 is a cross-sectional view of an absorbent polymer sheet.

FIG. 5 is an enlarged perspective view showing a topsheet of the sanitary napkin.

FIG. 6 is a perspective view showing an apparatus for measuring a creme absorption height.

FIG. 7 is a perspective view of an apparatus used for measuring a liquid passage time.

FIG. 8 is a cross-sectional view showing a measuring device used for measuring absorption time and dynamic liquid return.

FIG. 9 is a perspective view showing a movable female waist model used for measurement of a dynamic return amount and a leak test.

FIG. 10 is a perspective view showing a state in which a sanitary napkin for testing is attached to a movable female waist model.

FIG. 11 is a graph showing the pore size distribution of the absorbent sheet (A).

FIG. 12 is a graph showing the pore size distribution of the absorbent sheet (B).

FIG. 13 is a graph showing the pore size distribution of the absorbent sheet (C).

FIG. 14 is a graph showing the pore size distribution of the absorbent sheet (D).

FIG. 15 is a graph showing the pore size distribution of the absorbent sheet (E).

FIG. 16 is a graph showing the pore size distribution of the absorbent sheet (F).

FIG. 17 is a graph showing the pore size distribution of the absorbent sheet (G).

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Surface material 2 Absorber 2A High diffusion high permeability absorption sheet 2B High absorption polymer 2C High permeability bulky sheet 3 Leakproof material

Continuation of front page (56) References JP-A-1-153157 (JP, A) JP-A-4-272261 (JP, A) JP-A-5-68693 (JP, A) JP-A-1-132900 (JP) , A) Jiko 56-6096 (JP, Y1) US Patent 4,100,324 (US, A)

Claims (9)

(57) [Claims] 1. A substantially vertically absorbent article having a liquid-permeable surface material, a liquid-retentive absorber, and a liquid-impermeable leakproof material, wherein the absorber has at least a part thereof: It comprises a high-diffusion and high-permeability absorbent sheet and a high-absorbent polymer, and the high-diffusion and high-permeability absorbent sheet comprises at least (a) a bulky hydrophilic fiber; 20 to 80 parts by weight (b) a hydrophilic fine fiber 80 to 20 parts by weight; (c) hot-melt adhesive fiber;
^2. The absorbent article according to claim 1, wherein the article has a thickness of 0.3 to 2.0 mm under ^two loads. 2. The absorbent article according to claim 1, wherein the superabsorbent polymer is sandwiched between the highly diffusive and highly permeable absorbent sheets. 3. A high-diffusion, high-permeability absorbing sheet having a total pore surface area of 1.0 m in a space diameter distribution measurement with a mercury porosimeter of 0.003 to 200 μm.
² / g or more, the pore surface area in the space diameter of 0.003 to 1 μm is 50 to 80% of the total pore surface area, and the pore surface area in the space diameter of 10 to 200 μm is
The absorbent article according to claim 1 or 2, wherein the content is 18 to 35%. 4. The highly diffusive and highly permeable absorbent sheet according to claim 1, wherein a Klemm absorption height after 1 minute with respect to physiological saline is 50 mm or more and a Krem absorption height after 10 minutes is 100 mm or more. Item 5. The absorbent article according to any one of Items 1 to 3. 5. The high-diffusion, high-permeability absorbent sheet according to claim 1, wherein a passage time of 10 g of an 85% by weight aqueous glycerin solution (by a predetermined measuring method) is 100 seconds or less. Absorbent articles. 6. The fiber according to claim 1, wherein the bulky hydrophilic fiber has a fiber cross-sectional area of 3.0 × 10 ⁻⁶ cm ² or more and a roundness of the cross section of 0.5 or more. The absorbent article according to the above. 7. The absorbent article according to claim 1, wherein the bulky hydrophilic fiber has a fiber cross-sectional area of 5.0 × 10 ⁻⁶ cm ² or more. 8. The hydrophilic fine fibers have a fiber cross-sectional area of 2.0 × 10 ⁻⁶ cm ² or less and a circularity of the cross-section of ^0.1 × 10 ⁻⁶ cm ² or less.
The absorbent article according to claim 1, wherein the number is less than 5. 9. An absorber comprising a high-permeability bulky sheet provided on the uppermost layer of the absorber, and further comprising the high-diffusivity / high-permeability absorber sheet and the high-absorbency polymer provided on the lower layer side. Wherein the highly permeable bulky sheet is made by mixing at least (a) bulky hydrophilic fibers; 30 to 98 parts by weight; (b) hot-melt adhesive fibers; 2 to 30 parts by weight. It has a thickness of 0.3 to 2.0 mm under a load of 2.5 g / cm ² , and has a Klemm absorption height of 20 to 80 mm and 1 after 1 minute with respect to physiological saline.
The Krem absorption height after 0 minute is 30 to 100 mm, and the passage time of 10 g of an 85% by weight aqueous glycerin solution is 10 to 5 mm.
9. The absorbent article according to claim 1, wherein the time is 0 second.