JP4901433B2 - Absorber and production method thereof - Google Patents

Description

  The present invention relates to an absorbent body preferably used for absorbent articles such as disposable diapers, sanitary napkins, and incontinence pads, and a method for producing the same.

  Absorbents for absorbent articles using continuous filament spread tows are known. For example, an absorber comprising a tow layer of crimpable acetate fibers and a pulverized pulp layer laminated on one side of this layer, in which both layers are integrated by pressing in the thickness direction of the absorber, is known. (See Patent Document 1). According to this absorber, the diffusibility of body fluid is improved. However, since acetate fibers have a lower water absorption capacity than pulp, a large amount of pulverized pulp must be used to increase the absorption capacity of the absorber. As a result, the absorber becomes thick, the flexibility is lowered, and the wearing feeling of the absorbent article is lowered.

  By the way, as a technique for preventing side leakage in a disposable diaper, for example, it is known to form convex ridges that protrude toward the wearer's skin on both sides of the absorbent body. However, in order to form the ridge portion, the manufacturing process becomes complicated, or the manufacturing cost increases.

  Apart from these techniques, the applicant previously has an absorptive having an absorbent body formed from pulp fibers, a superabsorbent polymer, and a large number of small masses of hydrophilic fibers having a longer fiber length than the pulp fibers. An article is proposed (see Patent Document 2).

JP-A-57-160457 Japanese Patent Application Laid-Open No. 07-024003

  An object of the present invention is to provide an absorbent body that is flexible and excellent in absorption performance, can efficiently prevent liquid leakage by controlling the diffusion of liquid, and can be produced easily. It is providing the manufacturing method of an absorber.

  The present invention achieves the above object by providing an absorbent body including a fiber assembly including long fibers and short fibers which are synthetic or semi-synthetic fibers.

  The present invention is an absorbent body having a long fiber web and massive particles contained in the web, wherein the long fiber is cut in at least a part of a range in which the particles are distributed in a plane direction of the web. Thus, the object is achieved by providing an absorbent body in which a large number of short fibers are generated.

  The present invention relates to a method for producing an absorbent body having a long fiber web and agglomerated particles contained in the web, wherein the long fiber is cut into a part of the web to produce a number of short fibers. And after spraying a lump of particles of a hydrophilic long fiber web, pressurize at least a part of the range in which the particles are dispersed in the thickness direction, and push the long fibers in the part to the particles. The object is achieved by providing a method for producing an absorbent body that is cut by contact.

  This invention is an absorbent article which comprises the absorber in any one of Claims 1-12, Comprising: The absorptivity in which the said short fiber exists in the site | part arrange | positioned facing a wearer's excretion part at the time of wear Articles are provided.

The absorbent body of the present invention is flexible and excellent in absorption performance, can control liquid diffusion and efficiently prevent liquid leakage, and is easy to manufacture.
According to the manufacturing method of an absorber of the present invention, such an absorber can be manufactured efficiently.

Hereinafter, the present invention will be described in detail based on the embodiments.
As shown in FIGS. 1 and 2, the absorbent body 10 according to the first embodiment includes a hydrophilic long fiber web 12 and a lump absorbent polymer 13 (lump particles) contained in the web 12. It comprises an absorbent core 11 and a wrap sheet 14 that covers the absorbent core 11.
The absorbent body 10 has a rectangular shape in plan view, and in a state where the absorbent body 10 is incorporated in an absorbent article, the longitudinal direction of the absorbent body coincides with the wearer's front-rear direction when worn.

The long fiber web 12 was originally composed of long fibers as a whole, but in the state completed as the absorbent body 10, the long fibers in a part of the web 12 are cut into short fibers. Yes. In the present invention, a portion made of short fibers generated by cutting the same long fibers as the portion made of long fibers is also a part of the long fiber web.
In the absorbent body 10 of this embodiment, the long fiber web 12 including short fibers generated by cutting long fibers is a fiber assembly including long fibers and short fibers that are synthetic or semi-synthetic fibers.

  The absorbent polymer 13 in the absorbent body 10 is unevenly distributed in part of the planar direction of the absorbent body 10. Specifically, as shown in FIGS. 1 and 2, it is located in a region M (hereinafter also referred to as a center region M) having a predetermined width in the center in the width direction of the absorbent body 10 in the plane direction of the web 12 of long fibers. It is unevenly distributed. The absorbent polymer 13 is distributed substantially uniformly in the portion located in the central region M, while the absorbent polymer 13 is substantially distributed in the portions located in both outer side regions S, S of the central region M. Does not exist.

  In the plane direction of the web 12, the range in which the absorbent polymer 13 is distributed, that is, the portion located in the central region M, has the same length as the long fibers 121 constituting the portions located in the side regions S and S. There are a large number of short fibers 122 produced by cutting the fibers. On the other hand, the long fiber 121 which comprises the part located in the side area | region S, S in the web 12 is maintaining the form of the long fiber. The long fibers 121 located in the side regions S and S are oriented in the longitudinal direction of the web 12.

The long fiber web 12 preferably includes crimped long fibers as the long fibers. The crimp ratio (JIS L0208) of the long fibers is preferably 10 to 90%, more preferably 10 to 60%, and still more preferably 10 to 50%. When the long fibers are crimped, the absorbent body 10 is easily deformed flexibly as a whole, and fits to the wearer when incorporated in the absorbent article, and is deformed into a concave shape to prevent it. The deformability to the concave shape when improving the leakage can be enhanced.
The long fiber web 12 preferably includes crimped short fibers as short fibers 122 (hereinafter, also referred to as long fibers derived from the long fibers) generated by cutting the long fibers. It is preferable that the crimped short fiber has the same degree of crimp as the above-described crimped long fiber. When the short fibers are crimped, the absorbent polymer is more stably held in the web, and the absorbent polymer is prevented from moving through the web or falling off the web.

The crimps of long fibers and short fibers may be two-dimensional or three-dimensional. The crimp rate of the long fiber is defined as a percentage of the difference between the length A when the long fiber is stretched and the length B of the original long fiber with respect to the length A when stretched. Calculated from the formula.
Crimp rate = ((A−B) / A) × 100 (%)

  The length of the original long fiber means a length in which both ends of the long fiber are connected with a straight line when the long fiber is in a natural state. The natural state means a state in which one end of the long fiber is fixed to a horizontal plate and hung downward by its own weight. The length when the long fiber is stretched refers to the length at the minimum load when the long fiber is stretched until there is no crimp. The crimp rate of the long fibers is as described above, and the number of crimps is preferably 2 to 25, particularly 4 to 20, especially 10 to 20 per cm. The crimp rate of the short fiber is measured in the same manner. However, the crimp rate is measured with a fiber having a length of 10 mm or more.

Hydrophilic long fibers (same as short fibers derived from long fibers) are inherently hydrophilic fibers, and are not inherently hydrophilic, but are hydrophilic when subjected to a hydrophilic treatment. Both fibers imparted with properties are included. Preferred are fibers that are inherently hydrophilic, more preferred are fibers made of acetate and rayon, and particularly preferred is acetate because the bulkiness is maintained even when the web is wet. As the acetate, it is preferable to use cellulose triacetate and / or cellulose diacetate.
Nylon, acrylic fiber, or the like can also be used as the long fibers constituting the web (the same applies to the short fibers derived from long fibers).

Hydrophilic long fibers (same as short fibers derived from long fibers) have a moisture content of less than 10%, particularly 1 to 8%, from the viewpoint of ensuring liquid permeability, that is, plasticizing even when water is absorbed. It is preferable from the viewpoint of not being softened because it is not made, or not clogging because the fiber is not swollen. In addition, fibers having a high moisture content absorb moisture from the fibers, or the fibers themselves have strong hydrophilicity, so that they are thickened by hydrogen bonding between fibers and between different parts of the same fiber, particularly in the manufacturing process of absorbent articles. When compressing to control the product, or when the absorbent article is left in a compressed state for a long time in a pack, etc., the product becomes hard and causes physical troubles such as a decrease in wearing feeling and rubbing there is a possibility.
The moisture content is measured by the method described in paragraph [0025] of Patent Document 2.

In the present invention, the long fiber means a fiber having a fiber length of preferably 70 mm or more, more preferably 80 mm or more, and even more preferably 100 mm or more when the fiber length is measured by the average fiber length measurement method (Method C) of JIS L1015. Say. However, when the total length L of the web to be measured (see FIG. 1) is less than 100 mm, the fibers in the web are preferably 50% or more, more preferably 70% or more, and even more preferably 80% or more. When extending over the entire length of the web, the fibers of the web are assumed to be long fibers. The long fibers used in the present invention are generally called continuous filaments. A bundle of continuous filaments is generally called a tow. Therefore, the long fiber in the present invention is a concept including a continuous filament.
Moreover, in this invention, a short fiber means the fiber whose fiber length measured by the measuring method similar to a long fiber is less than 70 mm, More preferably, it is 5-70 mm, More preferably, it is 10-50 mm.
Also, the absorbent body of the present invention is very short fiber (less than 5 mm in length) or close to powder that seems to be difficult to measure by the measurement method of JIS L1015 or may contain a large error. May be included.

The long fibers in the present invention have a fiber strength from the viewpoint of pressing and compressing a part of the long fiber web in the presence of massive particles (such as massive absorbent polymer) during the production of the absorbent body. It is preferable that it is 3 g / d or less, and it is preferable that it is 0.5-2.5 g / d.
The fiber strength is measured as follows.
[Measurement method of fiber strength]
JIS L1015 chemical fiber staple test method It was performed in accordance with the section of tensile strength. That is, one fiber was attached to a copy sheet so that the length (space distance) of the unfixed portion of the fiber was 20 mm (10 mm when the fiber was short). Specifically, each end of the fiber is affixed with a width of 18 mm [Scotch tape (product name) from Nichiban Co., Ltd.] so that the distance between the affixed tapes is 20 mm (or 10 mm if the fibers are short). Was fixed on a copy paper.
This sample was attached to a chuck of a tensile tester, the paper was cut in the vicinity of the upper and lower adhesive tape portions, and subjected to a tensile test.
As the apparatus, an ORIENTEC RTC-1150A type Tensilon tensile tester was used. The measurement range was switched appropriately using a full-scale 5 kg load cell. The pulling speed was 300 mm / min. Measurement was performed at 10 points, and the average value was taken as the measured value. Measurements were added except for the measurement values that fluctuated 20% or more with respect to the average value.
In addition, it is preferable that the fineness of a long fiber is 1.0-10 dtex, especially 1.5-8 dtex.

  The long fibers in the present invention have a fiber strength from the viewpoint of pressing and compressing a part of the long fiber web in the presence of massive particles (such as massive absorbent polymer) during the production of the absorbent body. It is preferable that it is 3 g / d or less, and it is preferable that it is 0.5-2.5 g / d.

Short fibers obtained by cutting long fibers with massive particles usually have a different cross-sectional shape at the end of the fiber and a cross-sectional shape at the center of the fiber.
Whether or not the cross-sectional shape at the end and the cross-sectional shape at the center of the fiber are different can be determined as follows.
(Judgment method for differences in cross-sectional shape)
The cross-sectional shape of the fiber end portion and the fiber center portion is observed using an electron microscope.
A magnification is observed at 500 times or more, and it judges with the observation result of ten short fibers extracted at random. The cross-sectional shape of the fiber end is observed from the cross-sectional direction in the fiber major axis direction by attaching the fiber vertically to the sample stage. The cross-sectional shape adopts a contour within the depth of focus of the electron microscope, and is not a projection of the end cross-section. Then, the cross-sectional shape of either one of the both end portions is the cross-sectional shape of the end of the fiber. The center part of the fiber is cut with a razor so that the tailing of the apparent length of the fiber does not occur, and observed in the same manner. The apparent length of the fiber is the distance between the ends when the ends are fixed on a cardboard or the like with a minimum load so that the fibers do not stretch.

Then, the image of the end cross section and the image of the fiber center section are compared, and when both shapes are substantially the same and the area is also approximately the same, the cross-sectional shape of the fiber end and the fiber center section In other cases, it is determined that “the cross-sectional shape at the end of the fiber and the cross-sectional shape at the center of the fiber are not the same”.
Here, the cross-sectional areas are substantially the same, as shown in FIG. 21 (a), when the image of the end cross-section and the image of the cross-section of the fiber center are superimposed, one image and the other image are The total area S1 of the non-overlapping part a is 30% or less of the area S2 of the part b where both images overlap [(S1 / S2) is 0.3 or less].
In addition, when superimposing the image of the end cross section and the image of the fiber central section, either or both images are rotated around the center point, or the center point is moved, so that both images are as much as possible. The area S2 of the portion b where the overlaps is increased.
FIG. 21A shows a case where the end cross section and the fiber center cross section are “substantially the same” and the cross-sectional area is also “substantially the same”, and FIG. 21B is the end cross section. And the cross section of the fiber central portion do not correspond to the “substantially the same” shape, and the cross-sectional area does not correspond to the “substantially the same”.

  From the viewpoint of obtaining good spot absorptivity, the short fibers derived from long fibers are preferably located at random positions in the longitudinal direction of the individual short fibers (cut ends) in the longitudinal direction of the absorbent body. .

In the present invention, it is preferable to use massive particles. As the massive particles, massive absorbent polymers are preferred. Bulk absorbent polymer is a polymer-containing absorbent polymer hydrogel that has been polymerized by an aqueous solution polymerization method, cast into a plate and then pulverized after drying, or the type of surfactant and the stirring force are controlled by a reverse phase suspension polymerization method. This is because the irregularly shaped particles are aggregated. On the other hand, there are spherical and plural spherical aggregates, fibers and scales.
The average particle diameter of the massive absorbent polymer is preferably 150 to 600 μm, particularly preferably 200 to 500 μm.

As the material of the absorbent polymer, various known polymer materials conventionally used for absorbent bodies such as disposable diapers and sanitary napkins can be used. For example, polyacrylic acid soda and (acrylic acid-vinyl alcohol) Examples thereof include a polymer, a crosslinked polyacrylic acid soda, a (starch-acrylic acid) graft polymer, a (isobutylene-maleic anhydride) copolymer and a saponified product thereof, potassium polyacrylate, and cesium polyacrylate.
The absorbent polymer preferably has a performance capable of absorbing and retaining water or physiological saline 20 times or more of its own weight.

  In addition to the massive absorbent polymer, the massive particles include, for example, organic and inorganic particles (deodorant, Antibacterial agents) can be used. These can be used individually by 1 type or in combination of 2 or more types. As the inorganic particles, those partially substituted with metal sites can be used. These may be used as aggregates or may be used in combination with another carrier. Two or more kinds of these massive particles can be used in combination. The average particle diameter of the porous particles such as activated carbon and silica gel is preferably 20 to 300 μm, particularly 50 to 150 μm. The average diameter of the aggregate or the complex with the carrier is preferably 150 to 600 μm, particularly preferably 200 to 500 μm. The function of these components is to suppress the smell of excreta absorbed by the absorber and the smell derived from the material.

As the absorbent polymer, a bulk polymer and a non-bulk polymer can be used in combination. In addition, when cutting long fibers without using massive particles, it is possible to use only non-agglomerated polymers.
Non-bulk polymers include a method of spray-drying with a mixture of a monomer, a polymerization initiator, a crosslinking agent, etc., and a method of adjusting the type of solvent or surfactant by reverse phase suspension polymerization (generally, polymer By reducing the difference between the sp value of the solvent and the solvent, a spherical polymer free from surface irregularities can be obtained.

  In the absorbent body of the present invention, when the absorbent polymer is compressed by a roll or the like and a part of the long fiber is cut, there is a possibility that a part of the absorbent polymer is crushed and the particle diameter becomes fine. An absorbent polymer with a small particle size is more likely to be packed more closely than an absorbent polymer with a large particle size, which may cause gel blocking or a decrease in the rate of liquid uptake into the absorber. Further, when an absorbent polymer subjected to surface cross-linking is used, a portion having a weak internal cross-linking is exposed by pulverization, and similarly there is a risk of gel blocking. Gel blocking leads to liquid residue on the surface and liquid return. Therefore, in preparation for such a situation, the absorbent body of the present invention can contain various buffering agents so that a buffer system is established when excrement is absorbed by the absorbent body. That is, various organic and inorganic buffering agents, that is, acetic acid, phosphoric acid, citric acid, succinic acid, adipic acid, malic acid, lactic acid, or salts thereof can be used alone or in combination, or various amino acids can be used. In addition, various organic and inorganic buffering agents have the effect of neutralizing excrement, for example ammonia generated by decomposition of urine, to keep the diaper neutral to weakly acidic, thereby allowing excretion from the diaper to the skin. Even if there is a liquid return of an object, the influence on the skin can be reduced. Furthermore, since various organic and inorganic buffer agents have a function of neutralizing alkali such as ammonia, when a fiber having an ester bond in a molecular structure such as an acetate fiber is used as a long fiber constituting the web 12. Can also be expected to prevent the fiber from being damaged due to the decomposition of the ester bond by alkali.

  In addition, hydrophilic fine powder or short fibers can coexist in the web for the purpose of enhancing the spot absorbency, which is the effect of the present invention, and for the purpose of improving the liquid retention and absorption speed and improving the dryness. Examples of hydrophilic fine powders or short fibers include fibrillated or non-fibrillated cellulose powder, carboxymethyl cellulose and its metal salt, carboxyethyl cellulose and its metal salt, hydroxyethyl cellulose and its derivatives, silk powder, nylon powder, Examples include short fibers such as rayon, cotton, and wool. Among these, it is preferable to use cellulose powder because the above effects can be improved to the maximum. The hydrophilic fine powder or short fiber may be sprayed on the web before the absorbent polymer is sprayed, or may be mixed with the absorbent polymer and sprayed on the web at the same time.

  In addition, when the fiber length of the cut short fibers of the present invention is shortened, the web shape retention is improved, the web compression recovery is improved, the web is less likely to be twisted, and the web For the purpose of improving the transportability, it is preferable to join the long fibers constituting the web. For joining long fibers, for example, a water-soluble adhesive such as polyvinyl acetate or acrylic emulsion can be used.

  When long fibers are made of acetate, an agent capable of dissolving and plasticizing acetate, such as triacetin, can be sprayed on the web after the absorbent polymer has been sprayed to dissolve and plasticize the acetate, thereby joining the long fibers together. it can.

  Another method for joining long fibers includes a method in which synthetic pulp of thermoplastic resin is dispersed in a web and then heated to melt the synthetic pulp. Synthetic pulp can be spread on the web simultaneously with or before the absorbent polymer. When spraying, it is preferable to suck from the surface of the web opposite to the spray surface so that the synthetic pulp and the absorbent polymer are sufficiently distributed in the web. When the long fibers are made of a thermoplastic resin, it is preferable to use a synthetic pulp made of a thermoplastic resin having a melting point lower than that of the thermoplastic resin.

  When embossing is performed on the absorbent body, many portions where the web is consolidated by embossing are formed. As a result, there are high and low fiber density portions in the web. Therefore, there is a difference in capillary force between the high fiber density portion and the low fiber density portion, and the absorbent body 1 has higher liquid drawability.

  In order to further improve the spot absorbability of the liquid, and further to improve the web shape retention, on the side and / or under the web, or in addition to or instead of the web. One or a plurality of sheet materials such as paper and non-woven fabric are overlapped or covered, and the web and the sheet material are joined by an adhesive applied to the sheet, or heat-sealed. According to this method, a sheet-like absorbent body in which a web is sandwiched and fixed between a pair of sheet materials can be obtained. Such a sheet-like absorber has high rigidity due to the bonding with the sheet material and the rigidity of the sheet material itself, thereby improving the handling property, and can be easily transported by itself. . Moreover, since this sheet-like absorber can be easily cut or cut into a desired shape, an absorber according to the shape of the absorbent article can be easily produced.

In the case where the sheet material and the web are bonded with an adhesive to enhance the shape retention of the web, it is preferable to apply the adhesive so as not to impair the water permeability, softness, and air permeability of the web. For this purpose, it is advantageous to apply the adhesive in the finest possible fiber form and intermittently (for example, spiral, linear, continuous Ω shape). This is because the fibers can be joined at a large number of joining points without deteriorating the characteristics of the web. For example, this can be achieved by using a UFD fiber (trade name) which is a kind of hot melt coating apparatus. There is no restriction | limiting in particular in the kind of adhesive agent, Both a hydrophilic adhesive agent and a hydrophobic adhesive agent can be used. Particularly preferred is a hydrophilic adhesive. Examples of the hydrophilic adhesive include cycloflex (registered trademark of National Starch and Chemical Co., Delaware, USA) which is a hydrophilic hot melt pressure-sensitive adhesive.
Note that, although the sheet material and the web are mainly bonded to each other, a part of the adhesive is included in the web and includes a case where the fibers in the thickness direction of the web are bonded to each other.

It is also advantageous from the viewpoint of improving the absorption performance of the absorbent body that the above sheet material is stacked on and / or under the web. In order to improve the absorption performance of the absorbent body, it is preferable to use various fiber sheets and fiber webs as the sheet material. Examples thereof include air-through nonwoven fabric, airlaid nonwoven fabric, dry pulp nonwoven fabric, cross-linked pulp and paper containing cross-linked pulp, and composites thereof. One of these sheet materials may be used, or a plurality of sheets may be used in an overlapping manner. The fibers constituting these sheet materials preferably have a fiber diameter of 1.7 to 12 dtex, particularly 2.2 to 7.8 dtex, particularly 3.3 to 5.6 dtex. Basis weight 15~200g / m ^2, especially 20 to 150 g / m ^2, especially is preferably 25~120g / m ^2. In particular, when it is desired to improve the liquid uptake rate, to prevent liquid return, or to promote liquid diffusion in the sheet material, the basis weight is 15 to 100 g / m ² , particularly 20 to 80 g / m. ² and particularly preferably 25 to 50 g / m ² . On the other hand, if you want to improve the cushioning properties of the absorber, if you want to make it difficult for the absorber to twist, if you want to impart compression recovery to the absorber, or if you want to suppress the evaporation of water vapor from the absorber, the basis weight is 25~200g / m ^2, especially 30 to 150 g / m ^2, especially it is preferable to 40 to 120 g / m ^2.

According to the absorbent body 10 of the present embodiment, as shown in FIG. 3, a disposable diaper is used so that the central region M where short fibers are generated is located at a site P facing the liquid excretion part of the wearer. By using it by incorporating it into an absorbent article such as a sanitary napkin, the liquid excreted from the liquid excretion part (urine, menstrual blood, etc.) can be used from a narrow range of the absorbent body 10 due to excellent spot absorbability by short fibers. The absorbent body 10 is smoothly absorbed. Then, the liquid absorbed by the absorbent body 10 is absorbed by the absorbent polymer 13 that is unevenly distributed at the site, and is stably held in the absorbent body 10.
When a large amount of liquid is supplied onto the absorber 10 in a short time, or when a large amount of liquid is absorbed by the absorber 10 due to long-time use or the like, the liquid diffuses to the side regions S and S. Sometimes. However, since the long fibers exist in each of the side regions S and S while maintaining the form thereof and they are oriented in the longitudinal direction of the absorbent body, the liquid reaching the side regions S and S is absorbed. It diffuses favorably in the longitudinal direction of the body 10 (front and back direction of the wearer), and diffusion in the direction across the side regions S, S is suppressed. As a result, leakage of liquid from both side edges of the absorber 10 is effectively prevented, and a wide range of the absorber is effectively utilized.

The absorbent polymer 13 and the short fibers 122 derived from long fibers in the absorbent body 10 of the present embodiment are both present in the central region M of the absorbent body 10, and the range in which the absorbent polymer (particles) 13 is distributed. And the range in which the short fibers 122 are generated coincide with each other.
From the viewpoint of preventing side leakage when incorporated into an absorbent article and used, the width of the range in which the short fibers 13 are generated in the width direction of the absorbent body 10 (same as the width of the central region M) W1 ( 1) is preferably 20 to 95%, particularly 50 to 85%, of the total width W (see FIG. 1) of the absorbent body 10, and the width (side region S) in which short fibers are not substantially present. W2 (see FIG. 1) is preferably 5 to 80%, particularly preferably 15 to 50%, of the entire width W of the absorbent body 10.

  As the wrap sheet 14, a water-permeable sheet material such as a pulp sheet such as tissue paper or a water-permeable nonwoven fabric is preferably used. However, the portion of W2 that does not substantially contain the absorbent polymer 13 and the short fibers 122 may not be covered with the wrap sheet.

The absorbent polymer used in a preferred embodiment of the present invention has a physiological water absorption of 30 g / g or more, particularly 30 to 50 g / g by centrifugal dehydration. It is preferable from the point which prevents that the gel feeling after liquid absorption falls. The absorption amount of the absorbent polymer by centrifugal dehydration is measured as follows. That is, 1 g of absorbent polymer was swelled with 150 ml of physiological saline for 30 minutes, then placed in a 250 mesh nylon mesh bag, dehydrated with a centrifuge at 143 G (800 rpm) for 10 minutes, and the total weight after dehydration was measured. To do. Next, the amount of water absorption (g / g) by centrifugal dehydration is calculated according to the following formula.
Water absorption amount by centrifugal dehydration method = (total weight after dehydration−weight of nylon mesh bag−weight of absorbent polymer when dried−weight of remaining nylon mesh bag liquid) / weight of absorbent polymer when dried

Further, the absorbent polymer has a liquid passage time measured by the following method of 20 seconds or less, particularly 2 to 15 seconds, particularly 4 to 10 seconds, and it causes the occurrence of gel blocking and the resulting decrease in absorption performance. It is preferable from the viewpoint of preventing leakage due to liquid leakage due to prevention of absorption and inadequate absorption. The measurement of the liquid transit time is as follows. That is, 0.5 g of the absorbent polymer was added to physiological saline in a state where the cock was closed in a cylindrical tube having a cross-sectional area of 4.91 cm ² (inner diameter: 25 mmφ) and an openable / closable cock (inner diameter: 4 mmφ). And with the saline, the absorbent polymer is swollen until it reaches saturation. After the swollen absorbent polymer settles, the cock is opened and 50 ml of physiological saline is allowed to pass through. The time required for 50 ml of the physiological saline to pass through is measured, and this time is taken as the liquid passage time. The liquid passage time is one of the indexes reflecting the gel strength of the absorbent polymer. The shorter the liquid passage time, the stronger the gel strength.

  As the absorbent polymer, it is more preferable to use an absorbent polymer having high liquid permeability under load. From the viewpoint of effectively preventing gel blocking of the absorbent polymer, the absorbent polymer preferably has a flow rate value of 30 to 300 ml / min, more preferably 32 to 200 ml / min, still more preferably 35 to 100 ml. / Min. When the value of the liquid flow rate is less than 30 ml / min, the absorbent polymers saturated and swollen by the liquid absorption adhere to each other under a load, and the passage of the liquid is hindered to easily cause gel blocking. The larger the value of the flow rate, the better from the viewpoint of preventing the occurrence of gel blocking. However, if the value of the flow rate is as high as about 40 ml / min, the occurrence of gel blocking is almost certainly prevented. When the liquid flow rate exceeds 300 ml / min, the fluidity of the liquid in the absorber is too high, especially when a large amount of excreta is excreted at one time, and in older infants or adults. When the excretion rate is fast as described above, the liquid may not be sufficiently fixed when the absorber is further thinned, which may cause leakage. In general, increasing the liquid flow rate increases the degree of crosslinking of the absorbent polymer, lowers the absorption capacity per unit weight of the absorbent polymer, and a large amount of absorbent polymer must be used. From these viewpoints, the upper limit value of the flow rate is determined.

  Moreover, as an absorptive polymer which can be used in preferable embodiment of this invention, what satisfies each said characteristic is preferable, for example, polyacrylic acid soda, (acrylic acid-vinyl alcohol) copolymer, Examples include cross-linked poly (sodium acrylate), (starch-acrylic acid) graft polymer, (isobutylene-maleic anhydride) copolymer and saponified product thereof, potassium polyacrylate, and cesium polyacrylate. In order to satisfy the above characteristics, for example, a crosslink density gradient may be provided on the surface of the absorbent polymer particles. Alternatively, the absorbent polymer particles may be non-spherical amorphous particles. Specifically, the method described in JP-A-7-18495, column 7 line 28 to column 9 line 6 can be used.

  The absorbent body of the present invention having a long fiber web has a sparse structure with large gaps between fibers compared to a conventional absorbent body mainly composed of flap pulp, so that the absorbent body is permeable to liquid. It is also a good thing. Therefore, when the absorption rate of the absorbent polymer is low, the liquid may pass through the absorber before being absorbed by the absorbent polymer, and may not be sufficiently absorbed by the absorber. From this viewpoint, it is preferable that the absorbent polymer contained in the web has a sufficiently high absorption rate. Thereby, the liquid can be reliably held in the absorber. The absorption rate of the absorbent polymer is generally expressed in the technical field by the measured value of the DW method. The absorption rate (ml / 0.3 g · 30 sec) by the DW method is measured by using an apparatus (Demand Wetability Tester) generally known as an apparatus for performing the DW method. Specifically, a polymer spray table [70 mmφ, No. 2 Filter paper with glass filter no. On the stand placed on 1], 0.3 g of the absorbent polymer to be measured is sprayed. The amount of water absorption at the time when the absorbent polymer is sprayed is taken as 0, and the amount of water absorption after 30 seconds (this absorption amount is measured by a burette scale indicating the amount of decrease in the physiological saline water level) is measured. The value of the obtained absorption amount is taken as the water absorption rate. The absorption rate can be designed by the shape, particle size, bulk density, degree of crosslinking, etc. of the absorbent polymer.

  In an embodiment in which the absorber does not contain pulp or the pulp content in the absorber is 30% by weight or less, the absorption rate measured according to the DW method is 2 to 10 ml / 0.3 g · 30 sec, especially 4 Absorptive polymers of ˜8 ml / 0.3 g · 30 sec are preferably used. In addition, the absorbent polymer having such an absorption rate has been avoided in the conventional absorbent body mainly composed of fluff pulp because it causes gel blocking and consequently liquid leakage. . On the other hand, in the present embodiment, the web has a sparse structure, so the liquid is taken into the web and the speed of the taken-in liquid is high, so it has a high absorption speed. Even if an absorptive polymer is used, gel blocking hardly occurs, and conversely, liquid leakage is effectively prevented.

  As described above, an absorbent polymer having a short liquid passage time or an absorbent polymer having a high absorption rate may be used alone, but another absorbent polymer having a liquid passage time and an absorption speed within the above-described desirable ranges. May be mixed or coexisted. For example, the case where the absorbent polymer S1 having a relatively short liquid passage time and the absorbent polymer S2 having a relatively long liquid passage time are mixed and used may be mentioned. In this case, when the absorbent polymer S1 and the absorbent polymer S2 are compared, the absorbent polymer S2 has higher absorption capacity and absorption speed, but has low resistance to gel blocking. By making the absorbent polymer S1 and the absorbent polymer S2 coexist, the absorbent polymer S1 that is hard (that is, hard to cause gel blocking) enters between the absorbent polymer S2 having high absorption performance, so that the absorbent body is more efficient. Can be used. As another example, there is a method in which an absorbent polymer S3 having a relatively high absorption rate and an absorbent polymer S4 having a relatively low absorption rate coexist. In this case, the absorbent polymer S3 is arranged on the back sheet side, and the absorbent polymer S4 is arranged on the top sheet side, so that the liquid uptake speed of the absorber is further increased and the liquid fixing ability is also enhanced. Can do. As another example, the same effect can be obtained by arranging the absorbent polymer S1 having a short liquid passage time on the top sheet side and the absorbent polymer S3 having a high absorption rate on the back sheet side.

  By using the absorbent polymer having the specific absorption performance described above, the amount of liquid return is further reduced even though the absorbent body of the present invention is thin and soft. The amount of liquid return is preferably 1 g or less, more preferably 0.5 g or less, and even more preferably 0.25 g or less. The method for measuring the amount of liquid return is as follows. In the case of an infant paper diaper (M size), 160 g of colored physiological saline is injected into the central portion in the width direction at a position 150 mm from the abdominal edge of the diaper using a funnel. Red No. 1 is used for coloring, and the amount of pigment added is 50 ppm (0.5 g for 10 liters of physiological saline). Ten minutes after the completion of injection, filter paper No. Put 10 sheets of 4A on the diaper. A pressure of 3.43 kPa is applied from the top of the filter paper for 2 minutes to allow the filter paper to absorb the physiological saline. The weight of the filter paper is measured, and the increase in weight is taken as the liquid return amount. Three measurements are taken. If the size of the diaper is different, change the injection amount of physiological saline and the pressure condition of the filter paper as follows. In the case of baby diapers, pressurization of the filter paper is unified at 3.43 kPa, and the amount of physiological saline injected is changed according to the size of the diaper (new baby, S size is 120 g, other sizes are 160 g). On the other hand, in the case of absorbent articles for adults including sanitary products, the pressure on the filter paper is unified at 5.15 kPa. In the case of a sanitary product, the liquid to be injected is horse blood 10 g instead of physiological saline.

Next, the preferable manufacturing method of the absorber 10 (one embodiment of the manufacturing method of the absorber of the present invention) will be described with reference to FIG.
The absorbent body manufacturing apparatus shown in FIG. 4 includes a fiber opening mechanism 2 and a fiber opening mechanism 2 for obtaining a long fiber web 12 by continuously stretching and opening the tow 12a made of long fibers in the longitudinal direction. A tension relaxation mechanism 3 that transports the opened web 12 to a supply position of the polymer 13 in a state where tension is relaxed, a wrap sheet supply mechanism 4 that supplies a wrap sheet 14 to one side of the long fiber web 12, and a wrap sheet An absorbent polymer supply mechanism 6 for supplying the absorbent polymer 13 to the web 12 on the side opposite to the wrap sheet 14 side, and portions 14a of the wrap sheet 14 extending from both side edges of the web 12; 14a is folded, the folding mechanism 7 for covering both sides of the web 12 with the wrap sheet 14, and the thickness of the web 12 having both sides coated with the wrap sheet together with the wrap sheet. Pressurized compressed, which comprises a long fiber cutting mechanism 8 for cutting the long fibers in a portion of the web 12.

  The fiber opening mechanism 2 is configured to continuously pull out the belt-like tow 12a from the original fabric in a folded and compressed state, and sequentially open the tow 12a during conveyance. The opening mechanism 2 includes opening machines (banding jets) 21 to 23. Further, a guide 24 for lowering the tow 11 once sent upward is provided between the spreaders 21 and 22, and a pretensioning roll 25 and a blooming roll 26 are provided between the spreaders 22 and 23. It has. The spreaders 21 to 23 are devices that spread air by blowing air to open the tow being conveyed. The pretensioning roll 25 includes a pair of rolls 250 and 251 that nip the tow 12a opened by the spreader 21 and feed it at a predetermined speed. The blooming roll 26 includes a metal groove roll 260 having a large number of grooves and ridges extending in the circumferential direction, and an anvil roll 261 having a peripheral surface formed of rubber, and the pretensioning roll 25. The tow 12a is opened by providing a speed difference between the two and generating a portion where the protruding portion of the groove roll 260 presses and applies tension and a portion which is located in the groove portion of the groove roll 260 and does not apply tension. Let

  The tension relaxation mechanism 3 includes a feed roll 31 and a vacuum conveyor 32 that are arranged downstream of the spreader 23. The feed roll 31 includes a pair of rolls 310 and 311 that are rotationally driven at a peripheral speed lower than the peripheral speed V2 of the blooming roll 26. The feed roll 31 is a tow in a state in which a long fiber web 12 obtained by opening the tow 12a by the opening mechanism 2 is stretched between the pretensioning roll 25 and the blooming roll 26 to increase the tension. Or it is supplied on the lap sheet 14 supplied on the vacuum conveyor 32 in a state where the tension is relaxed rather than the web. The vacuum conveyor 32 includes a breathable endless belt 320 that is driven at a transport speed V4 that is slower than the feed speed V3 of the feed roll 31 (the peripheral speed of the pair of rolls 310 and 311), and a vacuum box 321. . The web 12 supplied onto the lap sheet 14 on the vacuum conveyor 32 is further transported by the endless belt 320 while being in a relaxed state, and is transported to the polymer supply position.

  The wrap sheet supply mechanism 4 supplies the wrap sheet 14 to one side of the long fiber web 12. The wrap sheet supply mechanism 4 includes unwinding means for the wrap sheet 14 and guide rolls (not shown) for guiding the unwrapped wrap sheet 14 to the vacuum conveyor 32. A wound roll 41 and a drive device (not shown) for driving the roll 41 are provided.

  The absorbent polymer supply mechanism 6 sprays the absorbent polymer 13 from a polymer supply port arranged on the upper surface side (the surface side opposite to the wrap sheet 14 side) of the long fiber web 12. A vacuum box 321 is located on the opposite side of the polymer supply port with the endless belt 320 in between, and the absorbent polymer can also be sprayed in a state of being sucked from the back side of the web 12 by the vacuum box 321. it can. The width of the polymer supply port in the direction orthogonal to the conveyance direction (longitudinal direction) of the web 12 is narrower than the width of the web, and the polymer 13 is dispersed only in a predetermined width region at the center in the width direction of the web 12. Has been made.

  The folding mechanism 7 includes folding guides 71 on both sides in the flow direction. The wrap sheet 14 is pulled by a pair of rolls 80 and 81 constituting the long fiber cutting mechanism 8 and is continuously conveyed, while the wrap sheet 14 extends outward from both side edges of the web 12. 14 a and 14 a are respectively folded back to the upper surface side of the web 12 by the guide 71. By this folding, the upper surface side of the web 12 is also covered with the wrap sheet 14, and as a result, the upper and lower surfaces of the web 12 are covered with the wrap sheet 14.

The long fiber cutting mechanism 8 has a continuous fiber web 12 coated on both sides with a wrap sheet (hereinafter, a composite comprising a long fiber web 12 on which a polymer is dispersed and a wrap sheet 14 covering the web). A pair of rolls 80 and 81 that pressurize and compress in the thickness direction across the body 100).
One roll 80 has an outer peripheral surface 80M of a predetermined width portion in the center in the axial direction made of an elastic material such as rubber and silicon, and an outer peripheral surface 80S located on both sides of the central region in the axial length direction. It consists of hard materials (inelastic materials) such as metals such as steel. The width in the direction perpendicular to the web 12 of the outer peripheral surface 80M made of an elastic material in the roll 80 is substantially the same as the width in the same direction of the polymer supply port.
An absorbent continuous body cutting mechanism 5 is provided downstream of the long fiber cutting mechanism 8. The absorbent continuous body cutting mechanism 5 includes a cutter roll 51 and an anvil roll 52 provided with a cutting blade 51a extending in the axial length direction, and the absorbent continuous body 100 of each absorbent body incorporated into an absorbent article. Cut to length.

  In order to manufacture the absorbent body 10 using the above-described manufacturing apparatus, as shown in FIG. 4, the strip-like tow 12 a is continuously drawn out from the original fabric by the fiber opening mechanism 2, and compressed by the fiber opening machines 21 to 23. The tow 12a is opened by widening the width of the tow 12a with air and stretching the tow 12a due to the difference in peripheral speed between the pretensioning roll 25 and the blooming roll 26, and the web 12 made of long fibers is obtained.

Then, the obtained web 12 is supplied onto the lap sheet 14 supplied on the vacuum conveyor 32 via the feed roll 31.
Then, while the web 12 is conveyed along with the wrap sheet 14 by the vacuum conveyor 32, the absorbent polymer 13 is sprayed on the web 12 by the absorbent polymer supply mechanism 6.

In the present embodiment, the absorbent polymer 13 is dispersed only in a region having a predetermined width at the center in the width direction of the web 12. Further, the absorbent polymer 13 is continuously sprayed in the longitudinal direction of the web 12. The dispersion amount of the absorbent polymer 13 is preferably equal to or more than the basis weight of the web 12 from the viewpoint of favorably cutting the long fibers in the long fiber cutting described below, more preferably twice. As mentioned above, More preferably, it is 3 times or more. For example, when the basis weight of the web 12 is 30 g / m ² , the spray amount of the absorbent polymer 13 is preferably 30 to 400 g / m ² , particularly preferably 60 to 300 g / m ² .

  In the present embodiment, the web 12 obtained by opening the tow 12a is laminated on the lap sheet 14 in a state where the web 12 is contracted from the maximum stretched state when the tow 12a is opened. More specifically, the circumferential speed V2 of the blooming roll 26 is made faster than the circumferential speed V1 of the pretensioning roll 25 to open the tow 12a, while the wrap sheet is made more than the circumferential speed V2 of the blooming roll 26. 14 is slowed down (same as the conveyance speed of the endless belt 320 of the vacuum conveyor 32), so that the tension of the web 12 on the vacuum conveyor 32 is relaxed to develop crimpability. Thereby, the preferable crimp rate of the long fiber and the short fiber mentioned above can be expressed efficiently. In the present embodiment, the maximum stretched state when the tow 12a is opened is the stretched state between the pretensioning roll 25 and the blooming roll 26.

  In the present embodiment, a wrap sheet 14 having a width sufficient to cover the upper and lower surfaces of the web 12 is used as the wrap sheet 14. As shown in FIG. 4, after the absorbent polymer 13 is supplied to the web 12, the wrap sheet 14 has portions 14 a and 14 a extending from both side edges of the web 12 by the folding mechanism 7. The upper side is also covered with a wrap sheet. As the wrap sheet 14, various materials conventionally used when enveloping the absorbent core can be used without particular limitation.

Next, pressure compression by the long fiber cutting mechanism 8 and cutting of the long fibers are performed on the absorbent continuous body 100. In this compression and long fiber cutting, the absorbent continuum 100 is inserted into a pair of rolls 80 and 81, and the entire region or a part of the web 12 where the absorbent polymer 13 is dispersed is disposed in the thickness direction. Under pressure.
The long fiber is cut in a range where the absorbent polymer 13 is dispersed, and between the outer peripheral surface 80M made of an elastic material of one roll 80 and the outer peripheral surface of a hard material of the other roll 81. Occurs in the sandwiched and pressurized area. As shown in FIG. 5, the long fibers are cut when the long fibers 121 are pressed against the massive absorbent polymer 13.
And the absorber continuous body 100 by which the long fiber in a part of web 12 was cut | disconnected by the cutting mechanism 5 of an absorber continuous body is made into the desired dimension according to the kind, dimension, etc. of the absorbent article in which it is integrated. The absorber 10 is cut.
According to the manufacturing method of this embodiment, the absorber 10 of the form mentioned above can be efficiently continuously produced in this way.

  Examples of the absorbent article into which the absorbent body according to the present invention is incorporated include disposable diapers, sanitary napkins, panty liners (orimono sheets), incontinence pads, and the like. The absorbent article generally includes a liquid-permeable top sheet, a liquid-impermeable or water-repellent back sheet, and an absorbent body interposed between these two sheets.

  According to the manufacturing method of the absorbent body 10 of the present embodiment, spot absorption is performed at a desired site by appropriately adjusting the range in which the massive absorbent polymer is dispersed and the range in which long fibers are cut by pressure compression. An absorber having a region with excellent properties can be produced efficiently.

  In the manufacturing method of the absorbent body described above, the long fiber web and the absorbent polymer are combined, and then the long fibers are cut by a compression roll. However, the same is true even if the absorbent polymer is sprayed on the cut fibers and combined. The effect is obtained. As the fiber cutting method, for example, a known method such as a method of cutting a plurality of rolls in which a large number of slits are engraved, a method using a cutter blade, a water flow or a laser can be used. Since long fibers have crimps, even if some of the fibers are cut, the fibers are entangled with each other and can be carried on a conveyor or the like.

  FIG. 6 is a diagram schematically showing an absorbent body according to another embodiment of the present invention. In FIG. 6, a region RA with a solid line with a downward slanting line is a region in which the absorbent polymer is dispersed (the same as the region in which the absorbent polymer is distributed), and a region RB with a slanted line with a left downward dotted line However, this is a range in which the web 12 is compressed and compressed to produce short fibers derived from long fibers.

The absorber shown in FIG. 6A includes a range RB in which short fibers are generated in a range RA in which the absorbent polymer is distributed. Specifically, in both the longitudinal direction and the width direction of the absorbent body, the range RB in which short fibers are generated is narrower than the range RA in which the absorbent polymer is distributed.
The absorbent body shown in FIG. 6A is the above-described roll manufacturing method in the above-described absorbent body manufacturing method. It is possible to manufacture by using a roll in which non-cut portions made of are alternately formed and the width of the cut portion in the direction perpendicular to the web 12 is narrower than the width in the same direction of the polymer supply port. In this case, the long fibers at a portion compressed and compressed between the cutting portion made of the elastic material of the roll 80 and the outer peripheral surface made of the hard material of the roll 81 are cut. Instead of the non-cutting portion made of metal, a concave portion may be formed between the cutting portions, and the concave portion may be a non-cutting portion that does not cut the long fiber.

The absorber shown in FIG. 6B also includes a range RB in which short fibers are generated in a range RA in which the absorbent polymer is distributed. Specifically, in the width direction of the absorbent body, the range RB in which short fibers are generated is narrower than the range RA in which the absorbent polymer is distributed, and in the longitudinal direction of the absorbent body, the range in which the absorbent polymer is distributed. The length of RA and the range RB where the short fibers are generated is the same.
The absorbent body shown in FIG. 6B is the above-described manufacturing method of the absorbent body. As the roll 80 described above, the width of the outer peripheral surface 80M made of an elastic material in the direction perpendicular to the web 12 is the same direction of the polymer supply port. It can manufacture by using a roll narrower than the width | variety.

  In the absorber shown in FIG. 6C, the range RA in which the absorbent polymer is distributed and the range RB in which the short fibers are generated coincide. The absorbent body shown in FIG. 6 (c), in the above-described manufacturing method of the absorbent body, disperses the absorbent polymer intermittently, and as the roll 80, a cut portion made of an elastic material in the circumferential direction of the outer circumferential surface. , Non-cutting portions made of a hard material (non-elastic material) or non-cutting portions which are concave portions are alternately formed, and the width in the direction perpendicular to the web 12 of the cut portion is the width in the same direction of the polymer supply port Can be manufactured by using the same roll.

Each absorber shown in FIG.6 (d) and FIG.6 (e) has narrow range RB in which the short fiber has produced rather than range RA in which an absorptive polymer distributes. The absorbent body shown in FIG. 6 (d), in the above-described manufacturing method of the absorbent body, disperses the absorbent polymer over the entire surface of the web, and as the roll 80, a cut portion made of an elastic material in the circumferential direction of the outer peripheral surface; Non-cutting portions made of a hard material (non-elastic material) or non-cutting portions which are concave portions are alternately formed, and the width in the direction perpendicular to the web 12 of the cutting portion is the same width as the polymer supply port. It can be manufactured by using the same roll. In the absorbent body manufacturing method described above, the absorbent body shown in FIG. 6 (e) has an absorbent polymer dispersed on the entire surface of the web, and the roll 80 has a cut portion made of an elastic material in the circumferential direction of the outer peripheral surface. It can be manufactured by using a roll that is continuously formed and has the same width in the direction perpendicular to the web 12 of the cut portion as the width in the same direction of the polymer supply port.
In FIG. 6 (d) and FIG. 6 (e), the long fibers exist in a region other than that indicated by the range RB.

The absorbent body of the present invention is composed of long fibers at the front and rear end portions in the longitudinal direction of the absorbent body, for example, as shown in FIGS. 6 (a), 6 (c) and 6 (d). While having a part, you may have a part in which many short fibers derived from a long fiber exist among them. In that case, like the absorbent body shown in FIGS. 6 (a), 6 (c) and 6 (d), the left and right sides of the absorbent body also have portions made of long fibers, and as a whole, long fibers It is preferable that the portion made of the material surrounds the range where the short fiber is generated, but the portion made of the long fiber may not be provided on the left and right side portions of the absorbent body.
Also in the absorbent body shown in FIGS. 6A to 6E, the range RB where the short fibers are generated shows excellent spot absorbability, and therefore the range RB is opposed to the wearer's liquid excretion part. The liquid (urine, menstrual blood, etc.) excreted from the liquid excretion part is used in a narrow range of the absorbent body 10 by being incorporated in an absorbent article such as a disposable diaper or a sanitary napkin so as to be located at the site. Is absorbed smoothly and is stably held by the absorbent polymer present in the portion. In addition, when a large amount of liquid is supplied or a large amount of liquid is absorbed by the absorber, when the liquid reaches both sides in the longitudinal direction of the absorber, the long fibers oriented in the longitudinal direction of the absorber The liquid diffuses well in the longitudinal direction of the absorbent body (the wearer's front-rear direction), and the wide range of the absorbent body is effectively utilized, while the diffusion of the absorbent body in the width direction is suppressed.

FIG. 7 is a view showing an absorbent body according to still another embodiment of the present invention.
In the absorbent body 10 </ b> A shown in FIG. 7, the massive absorbent polymer 13 is unevenly distributed on a part of the absorbent body in the thickness direction, that is, on one side of the upper and lower surfaces. And in the plane direction of the web 12, the long fiber is cut | disconnected in the substantially whole region of the range where the absorptive polymer 13 distributes, and many short fibers 122 arise.
Absorbent body 10A disperses absorbent polymer 13 in the central region in the width direction of the strip-shaped long fiber web having a width approximately twice the width of absorbent body 10A, and the central region is made of elastic material and metal. After pressing and compressing between them, the long fibers in the central region are cut into short fibers 122, and then the portions located on both outer sides of the central region are folded and laminated on the central region. Is obtained.
The absorbent body 10A is preferably incorporated into the absorbent article such that the surface side where the massive absorbent polymer 13 is unevenly distributed is located on the skin side of the wearer.

FIGS. 8-10 is a figure which shows the state which incorporated the absorber 104 which is further another embodiment of this invention in the underpants type disposable diaper 101. FIG. This disposable diaper 101 is an embodiment of the absorbent article of the present invention.
The disposable diaper 101 includes an absorbent main body 105 having a liquid-permeable top sheet 102, a liquid-impermeable or water-repellent back sheet 103, and a liquid-retaining absorbent 104 positioned between both sheets 102, 103; And an exterior body 110 that is positioned on the outer side (non-skin contact surface side) of the absorbent main body 105 and that bonds and fixes the absorbent main body 105. The exterior body 110 is a pant-type having a waist opening and a pair of leg openings, with both side edges of the part located on the ventral side A and both side edges of the part located on the back side B being joined. It has a form. FIG. 8 shows a state in which the joint portion is peeled, the diaper is developed in a planar shape, and the elastic member of each portion is extended.
The exterior body 110 includes two sheets 111 and 112, and elastic members of respective parts fixed between the two sheets. In the disposable diaper 101, as shown in FIG. 8, between the two sheets 111 and 112, a waist elastic member 171 forming a waist gather at the peripheral edge of the waist opening, a leg gather at the peripheral edge of the leg opening. The waist elastic gathers in a state of being divided into left and right are formed in the waist part D that is a region from the position spaced 20 mm downward from the peripheral edge of the waist opening to the upper end of the leg opening. The waistline elastic members 191 are fixed in an extended state. Each elastic member 71, 81, 91 is joined by joining means such as a hot-melt adhesive. The sheet 111 has extended portions extending from the front and rear end edges of the sheet 112 in the diaper front-rear direction, and the extended main body 105 is disposed on the sheet 112 of the exterior body 110, respectively. Thereafter, the absorbent body 105 is folded back and bonded so as to cover the front and rear ends of the absorbent body 105.

As shown in FIGS. 8 to 10, the absorbent body 104 of the present embodiment configures the first absorbent core 141 that constitutes the non-skin contact surface side of the absorbent body 104 and the skin contact surface side of the absorbent body 104. And a second absorbent core 142. The first absorbent core 141 is disposed on the non-skin contact surface side of the second absorbent core 142.
In the absorbent body 104 of the present embodiment, the second absorbent core 142 includes a long fiber web and massive particles contained in the web, and the particles are distributed in the planar direction of the web. In at least a part of the range, the long fibers are cut to form a large number of short fibers.
The second absorbent core 142 has a rectangular shape in plan view, and has a length over the substantially entire length in the longitudinal direction of the absorbent main body 105 including the absorbent body 104 and a width slightly narrower than the width of the absorbent main body 105. ing.

The first absorbent core 141 has a substantially rectangular shape when seen in a plan view, but facilitates deformation of the absorbent body 104 into a three-dimensional shape on the left and right of the portion disposed on the crotch part C of the diaper 101. The missing portions 144 and 144 are provided. For the deformation of the absorbent body 104 into a three-dimensional shape, the absorbent body 104 is deformed so as to form a concave shape in the cross section in the diaper width direction (for example, the cross section shown in FIG. 10). Typical examples include a longitudinal deformation that deforms so as to form a concave shape in a cross section, and a composite deformation in which the deformations in both directions are combined.
As shown in FIGS. 8 and 10, the missing portion 144 in the present embodiment extends along the longitudinal direction of the absorbent body 104 at a position spaced apart from the side edge 143 of the absorbent body 104 in the crotch part C. Is formed.
Regarding the formation site of the missing part 144 formed in the crotch part C, being separated from the side edge part 143 of the absorbent body 104 means being separated at least at the center position in the longitudinal direction of the diaper. The central position of the diaper in the longitudinal direction is a position that bisects the entire length of the diaper in the developed and extended state in the longitudinal direction, and is the position of line III-III in FIG.

  As shown in FIG. 8, both ends 144a and 144b in the longitudinal direction of the missing part 144 in the first absorbent core 141 are open to the side edge part 143 of the absorber 104. Therefore, the 1st absorption core 141 is divided | segmented into plurality. That is, the crotch part C is divided into a central piece 141M located at the center of the absorbent body 104 in the width direction, and the crotch part C is divided into left and right side pieces 141S and 141S located on both sides of the central piece 141M. . The missing part in the case where the absorbent core has a missing part includes gaps generated between a plurality of divided pieces, like the missing part 144 of the present embodiment.

  In the absorbent body 104 of the present embodiment, many short fibers 122 derived from long fibers are generated in the second absorbent core 142 in the central portion in the width direction of the crotch part C of the diaper 101, which is the excretory part facing part of the diaper 101. Yes. More specifically, short fibers derived from long fibers are generated in a portion overlapping with a portion (a portion made of the central piece 141M) located between the left and right missing portions 144, 144 in the first absorbent core 141. By improving the spot absorptivity of the excretory part opposing part, the leak preventing property of the diaper 101 can be improved and the stickiness of the diaper can be reduced. On the other hand, in the portion of the long fiber web that overlaps the side pieces 141S and 141S, the long fiber 121 constituting the web maintains the shape of the long fiber, and the diffusion of the liquid in the diaper width direction is suppressed. As a result, side leakage prevention is improved.

  Moreover, in another embodiment, it overlaps with the part (part which consists of center piece 141M) and the side piece 141S and 141S which are located between the missing parts 144 and 144 on either side in the 1st absorption core 141, and side piece 141S, 141S. The short fiber derived from the long fiber is generated in the part. On the other hand, in the portion overlapping the left and right missing portions 144 and 144, even when the long fiber 121 constituting the web is in the form of maintaining the form of the long fiber, the same effect as the diaper can be exhibited. .

  As shown in FIGS. 9 and 10, the first absorbent core 141 in the present embodiment is arranged so as to overlap the non-skin contact surface side of the second absorbent core 142, and the missing portion 144 of the first absorbent core 41. 144 are located below the second absorbent core 142. The skin contact surface side of the absorbent body is the surface side of the absorbent body that faces the wearer's skin when worn, and the non-skin contact surface side of the absorbent body refers to both surfaces of the absorbent body. Of these, it is the surface side that is directed to the opposite side of the wearer's skin when worn.

  In the absorbent body 104 according to the present embodiment, the deformability of the absorbent body into a three-dimensional shape is improved because the first absorbent core 141 has the missing portion 144. As shown in FIG. Both side portions, specifically, portions located on both sides of the central piece 141M of the first absorbent core 141 easily stand up toward the wearer's skin when wearing the diaper.

The side of the absorbent body 104 stands up well, the viewpoint of forming an ideal three-dimensional shape that envelops the urination part, and the action of the central piece 141M located at the center in the width direction of the absorbent body 104, the sway of the absorbent body in the crotch part. From the viewpoint of preventing, the distance W3 (see FIG. 8) between the side edge portion 143 of the absorber and the missing portion 144 (the position of the end portion near the center of the missing portion in the diaper width direction) in the diaper width direction is the absorber. It is preferable that it is 10 to 40% of the width W (refer FIG. 8) of 104, and it is preferable that it is 20 to 30%. The width W4 (see FIG. 8) between the left and right missing portions 144 is preferably 20 to 120 mm, particularly 40 to 100 mm.
The width of the missing portion 144 (dimension in the diaper width direction) is preferably 3 to 20 mm, particularly preferably 5 to 15 mm. Further, the length of the missing portion 144 in the longitudinal direction of the diaper (in this embodiment, the same as the length of the side portion 141S in the longitudinal direction of the diaper) is preferably 10 to 35 cm, particularly preferably 15 to 30 cm in the diaper for infants. In an adult diaper, 15 to 55 cm, particularly 20 to 50 cm is preferable.

The bending rigidity in the diaper width direction of the first absorbent core 141 and the second absorbent core 142 is smaller in the second absorbent core 142 than in the first absorbent core 41.
The second absorbent core 142 preferably has a bending rigidity in the diaper width direction that is 10 to 50 g, particularly 20 to 40 g smaller than that of the first absorbent core 141. The second absorbent core 142 preferably has a bending rigidity in the diaper width direction of 50 g or less, particularly 40 g or less, and the first absorption core (first absorption core) F41 has a bending rigidity in the diaper width direction of 30. It is preferable that it is -80g, especially 40-70g.
The bending rigidity of the first absorbent core and the second absorbent core in the diaper width direction can be measured as follows.

<Measurement method of bending stiffness in the diaper width direction>
The bending stiffness value can be measured with a handle-ometer. The measuring method using the handle-ometer is in accordance with Japanese Industrial Standard “JIS L-1096 (General Textile Testing Method)”. An absorbent body cut to 150 mm in the longitudinal direction and 100 mm in the width direction is arranged in a direction perpendicular to the groove on a support base having a groove with a width of 30 mm. The center of the absorber is pushed with a blade having a thickness of 2 mm, and the resistance value (g) when the absorber is pushed in by 8 mm is measured with a load cell. The apparatus used in the present invention is a hand tester (handle-and-meter method) HOM-2 manufactured by Daiei Scientific Instruments. The average value of the three points is taken as the measured value.

In addition, the absorber 104 in this embodiment has a vertically long rectangular plan view shape in the diaper front-rear direction as a whole. The absorbent body 104 is fixed between the top sheet 102 and the back sheet 103 in a state where the entire body is covered with a water-permeable wrap sheet (not shown) made of tissue paper or a water-permeable nonwoven fabric. Yes.
Moreover, as for the surface sheet 102 in the diaper 101 which concerns on this embodiment, the part extended rather than the both-sides edge part of the absorber 104 is wound down on the non-skin contact surface of the absorber 104, and the non-absorber of the absorber On the skin contact surface side, it is fixed to the back sheet 103 with an adhesive or the like (not shown).
Each of the first absorbent core 141 and the second absorbent core 142 may be covered with a wrap sheet. The first absorbent core 141 and the second absorbent core 142 may be partially bonded by an adhesive or the like, or may not be bonded.

Leak-proof cuffs 106 are provided on both sides in the longitudinal direction of the absorbent main body 105 in the disposable diaper 101 so as to extend in the longitudinal direction of the diaper.
As shown in FIGS. 9 and 10, the leak-proof cuff 106 is formed by a leak-proof cuff forming sheet 160 and an elastic member 161 fixed to the leak-proof cuff forming sheet 160 in an expanded state.

The leak-proof cuff forming sheet 160 is preferably arranged so as to cover both side edges 105 c of the absorbent main body 105. Here, to cover both side edges of the absorbent main body 105, a leakproof cuff having uprightness can be formed at the crotch, and the side edges of the absorbent main body are worn by the wearer due to the presence of the leakproof cuff. It means that it is difficult to directly touch the skin.
More specifically, the leak-proof cuff forming sheet 160 absorbs the diaper at the abdominal side A and the back side B (preferably further the crotch C) of the diaper 101 in the unfolded and extended state (see FIG. 8). It is preferable that the skin main body 105 is disposed so as to extend from the skin contact surface side 105a to the non-skin contact surface side 105b. Moreover, it is preferable that the leak-proof cuff forming sheet 160 is fixed to the skin contact surface side 105b of the absorbent main body 105 in each of the abdominal side A and the back side B. With such a configuration, the leak-proof cuff easily wraps both sides of the absorbent main body and the leak-proof property is improved. The skin contact surface side 105a is the surface side of the absorbent main body 105 that faces the wearer's skin when worn, and the non-skin contact surface side 105b of the absorbent main body 105 is absorbent. Of both surfaces of the main body 105, the surface is directed to the side opposite to the wearer's skin when worn.

  As shown in FIG. 10, the leak-proof cuff 106 can stand at least in the crotch part C. A plurality of elastic members 161 are fixed along the free end 162 near the free end 162 of the leak-proof cuff 106. The sheet 160 for forming a leak-proof cuff is a surface on the skin contact surface side of the absorbent main body 105 in a three-fold state by being bent at two bent portions 163 and 164 on the abdominal side A and the back side B, respectively. It is fixed on the top by known joining means (heat seal, adhesive, etc.).

  In the disposable diaper 101, a sheet-shaped water-repellent sheet having a predetermined width is folded in two along a fold line along its longitudinal direction as a leak-proof cuff forming sheet 160, and a hot melt adhesive between the opposing layers is folded. Or the sheet | seat of the 2 layer structure joined by the partial heat | fever or the ultrasonic seal | sticker etc. is used. The elastic member 161 is fixed in an expanded state between the layers of the two-layer structure sheet.

  As shown in FIG. 10, the absorbent main body 105 at the crotch C has a fixed end of the leak-proof cuff 106 at a position inside the diaper width direction with respect to both side edges 105 c in the width direction of the absorbent main body 105. A fixing portion 167 with the leakage-proof cuff forming sheet 160 to be formed is provided. The fixing portion 167 is formed by connecting a leak-proof cuff forming sheet 160 and the extended portion of the surface sheet 102 that has been wound down by known joining means such as heat sealing, high-frequency sealing, ultrasonic sealing, and hot-melt adhesive. It is formed by bonding.

Further, an elastic member 166 for raising the side part of the absorbent main body is disposed in a stretched state at a portion on the outer side in the diaper width direction from the fixed part 167 in the absorbent main body 105.
The elastic members 166 are arranged on both side edges of the absorbent main body 105 so as to extend along the side edges and between the ventral side A and the back side B. The elastic member 166 in the disposable diaper 101 according to the present embodiment is disposed on both side edges of the absorbent main body 105, but the arrangement site is not particularly limited as long as it is outside the fixing part 167, and the absorber It can also be arranged between the sheet 104 and the top sheet 102 located on the skin contact surface side, between the absorber 104 and the back sheet 103, inside the wrap sheet (not shown) of the absorber 104, and the like. It can also be placed in these two or more locations. However, it is preferable that the absorbent main body 105 is disposed on both side edges or in the vicinity thereof.
It is preferable that the fixing | fixed part 167 exists in the site | part which entered 5-50 mm from the both-sides edge part 105c of the absorptive main body 105, especially about 10-30 mm inside the diaper width direction.

As shown in FIG. 10, in the width direction of the crotch part C of the diaper 101, the position P1 of the fixed end of the leak-proof cuff 106 is the position of the missing part 144 (position of the missing part 144 near the center in the diaper width direction). It is preferable that it substantially coincides with P2. The fixed end of the leak-proof cuff 106 is a portion where the absorbent main body 105 and the leak-proof cuff forming sheet 160 are joined on the side opposite to the free end of the leak-proof cuff 106. Since the positions P1 and P2 substantially coincide with each other, the rising property of both sides of the absorbent main body 5 is further improved, and the absorbent main body can more easily form an ideal three-dimensional shape that wraps the urine drainage part. Leakage prevention performance is further improved.
In the expression that the positions P1 and P2 substantially match, in addition to the case where the position P1 and the position P2 completely match, the accuracy error at the time of manufacture is taken into consideration, and the distance between the positions P1 and P2 The case where L (see FIG. 10) is within 10 mm is also included.
The above-mentioned distance W4 between the side edge portion 141 and the missing portion 144 of the absorbent body 104, the width W of the absorbent body, the width W3 between the left and right missing portions 144, the width of the missing portion, the absorbent main body 105 of the fixing portion 167. A preferable range of numerical values such as the distance from both side edge portions 105c and the distance between the positions P1 and P2 is measured at the center position in the longitudinal direction of the diaper.

  According to the disposable diaper 101 according to the present embodiment, in addition to the both sides of the absorber 104 being easily bent and standing, the presence of the elastic member 166 and the absorbent main body 105 and the leak-proof cuff forming sheet 160 As shown in FIG. 10, due to the fixing portion being in a specific position, a pocket which is concave toward the skin contact surface side between the upright side portions of the absorbent body 104 or the upright side portions of the absorbent main body. A structure is formed. The pocket structure makes it difficult for excrement to leak out, and when a large amount of urine is excreted in a short period of time, or when watery stools or soft stools that are difficult to absorb are excreted, the concave structure The excrement is difficult to leak from the pocket structure. Moreover, even if it leaks from a concave pocket, since the leak-proof cuff 106 which covers the side edge part of the absorptive main body 105 exists, the leakage from a diaper is prevented. That is, even if the excrement exceeds the side edge of the absorbent main body standing upright at the crotch, this leak-proof cuff is positioned on the outer side to prevent further excrement leakage. Because it is possible, it has excellent leakage performance. In addition, the leak-proof cuff 106 makes it difficult for the side edge of the absorbent main body to come into direct contact with the wearer's skin when worn, so that an uncomfortable feeling during wearing can also be prevented.

Further, the crotch portion C is a portion that is particularly susceptible to pressure from the left and right due to the movement of the wearer and the like, so that the compression force applied from the left and right due to the movement of the wearer at that portion rises on both sides of the absorber 104. Therefore, the pad stability of the absorber 104 (such as a twist preventing effect) can be improved.
Furthermore, the missing portion 144 is opened by the movement of the wearer spreading the leg or twisting the upper body, and the central piece 141M located at the center in the width direction of the first absorbent body 141 is separated from the side edge of the absorbent body. In this case, the gap 44 formed between the central piece 141M of the first absorbent core 141 and the side edge portion is caused by the second portion 44 of the first absorbent core 141 overlapping the low-rigidity second absorbent core 142. The absorption core 142 covers and prevents the excrement from leaking through the gap.

In addition, according to the disposable diaper 101 according to the present embodiment, the side leakage prevention performance can be dramatically improved, so that the leakage prevention performance is improved or the decrease is suppressed, while the width and inseam of the absorbent main body are suppressed. It is possible to improve the fit by narrowing the width of the part. Such an effect is that the leak-proof cuff 106 in the crotch part C stands up toward the wearer's skin, can secure a sufficient height, and narrows the substantial liquid-absorbing surface even when crushed. Combined with things that are difficult to do, it is played more reliably.
In addition, since the fibers contained in the second absorbent core are continuous, there is no pulling between the fibers, so that both the absorber side regions can be easily raised, and spot absorptivity can be imparted to the center of the absorber. Further, the prevention of lateral leakage is further improved. Therefore, it is preferable that the short fibers contained in the second absorbent core and the massive particles dispersed to generate the short fibers are biased to the central portion in the width direction.

  As a disposable diaper which narrowed the width | variety of a crotch part, the disposable diaper which satisfy | fills the conditions shown below can be illustrated as a particularly preferable example, for example. The width of the absorbent body 104: the maximum width in each of the back side portion B and the ventral side portion A is 60 to 140 mm, particularly 80 to 120 mm, and the maximum width in the crotch portion C is 50 to 140 mm, particularly 70 to 120 mm. Reference numeral 109 in FIGS. 9 and 10 denotes an adhesive that joins the absorbent main body 105 and the exterior body 110.

The first absorption core 141 used in the present embodiment has a time until the liquid reaches the front end of the diaper that the liquid diffusion speed in the diaper width direction is faster than the liquid diffusion speed in the diaper longitudinal direction. This is preferable from the viewpoint of improving the pre-leakage prevention performance.
In order to increase the diffusion rate of the liquid in a specific direction, a directional groove or the like can be formed by embossing or the like, but it is preferable to use one in which the constituent fibers are oriented in the direction. Whether the liquid diffusion rate is higher in the diaper width direction or the diaper longitudinal direction can be determined by, for example, cutting out a test piece that is long in each direction, and measuring and comparing the respective water absorption heights of the clems.

  13-17 is a figure which shows the absorber which is further another embodiment of this invention. Each absorber 10B-10F shown in FIGS. 13-17 contains the short fiber in the part which attached the oblique line in each figure.

Absorbent body 10B shown in FIG. 13 is an absorption body composed of a fiber assembly having a two-layer structure in which an upper fiber layer 91 mainly composed of short fibers and a lower fiber layer 92 mainly composed of long fibers are laminated. And an wrap sheet (not shown) covering the absorbent core 9. Similar to the absorbent body 10 shown in FIGS. 1 and 2, the wrap sheet covers the upper and lower surfaces and both longitudinal sides of the absorbent core 9. “Absorptive body including a fiber assembly including a long fiber and a short fiber that is a synthetic or semi-synthetic fiber” is, for example, an absorbent core made of a fiber assembly such as the absorbent body 10B. It may be covered with a wrap sheet.
The short fibers in the absorbent body 10B are unevenly distributed in the upper fiber layer 91 disposed on the skin side of the wearer when incorporated into the absorbent article, and the long fibers are worn by the wearer when incorporated into the absorbent article. It is unevenly distributed in the lower fiber layer 92 disposed on the side opposite to the skin side. That is, the long fibers and the short fibers are unevenly distributed at different sites in the thickness direction of the absorber.
In the upper absorbent layer 91, the proportion of short fibers having a fiber length of less than 70 mm in the constituent fibers is preferably 50 to 100%, more preferably 60 to 100%, still more preferably 80 to 100% based on weight. It is.
In the lower absorbent layer 92, the proportion of long fibers having a fiber length of more than 70 mm in the constituent fibers is preferably 50 to 100%, more preferably 60 to 100%, still more preferably 80 to 100% based on weight. It is.

According to the absorbent body 10B shown in FIG. 13, the upper fiber layer 91 containing short fibers exhibits excellent spot absorbability, so that the upper fiber layer 91 is positioned at a portion facing the liquid excretion part of the wearer. Thus, by incorporating it into an absorbent article such as a disposable diaper or a sanitary napkin, the liquid (urine, menstrual blood, etc.) excreted from the liquid excretion part can be absorbed into the absorbent body smoothly from a narrow range. Further, when a large amount of liquid is supplied or a large amount of liquid is absorbed by the absorber, the liquid is disposed on both sides in the longitudinal direction of the absorber or on the non-skin contact surface side of the upper fiber layer 91. When reaching the part, the long fibers oriented in the longitudinal direction of the absorbent body allow the liquid to diffuse well in the longitudinal direction of the absorbent body (front and back direction of the wearer), so that a wide range of the absorbent body is effectively utilized. On the other hand, diffusion in the width direction of the absorber is suppressed, and excellent lateral leakage prevention performance is obtained.
In the absorbent body 10 </ b> B, the width of the upper fiber layer 91 is narrower than the width of the lower fiber layer 92, but the width of the upper fiber layer 91 may be substantially the same as the width of the lower fiber layer 92.

Each of the absorbent bodies 10C to 10F shown in FIGS. 14 to 17 includes an absorbent core 9 made of a single-layer fiber assembly 93 and a wrap sheet (not shown) that covers the absorbent core 9. The wrap sheet covers the upper and lower surfaces of the absorbent core 9. The wrap sheet preferably covers the upper and lower surfaces of the portion 9S in which at least the short fibers of the absorbent core 9 are unevenly distributed.
In each absorber 10C-10F shown in FIGS. 14-17, the short fiber is unevenly distributed in the hatched part in each figure, and the long fiber is unevenly distributed in the part not hatched. That is, the long fibers and the short fibers are unevenly distributed at different portions in the planar direction of each absorber.

  The absorbent body 10C shown in FIG. 14 has a portion 9S in which short fibers are unevenly distributed on one end side in the longitudinal direction of the absorbent core 9 made of the fiber assembly 93, and long fibers are unevenly distributed on the other end side in the longitudinal direction. It has a portion 9L. The portion 9S in which the short fibers are unevenly distributed is arranged from the crotch part of the disposable diaper to the abdominal side part, and the part 9L in which the long fibers are unevenly distributed is arranged on the back side part of the diaper. And the so-called pre-leak (leak from the ventral side) can be effectively prevented. On the other hand, if the front and rear sides of the absorber are reversed, so-called rear leakage can be effectively prevented.

  An absorbent body 10D shown in FIG. 15 has a horseshoe-shaped portion 9S in which short fibers are unevenly distributed on one end side in the longitudinal direction of the absorbent core 9 made of the fiber assembly 93, and a long end on the other end side in the longitudinal direction. It has the part 9L where the fiber is unevenly distributed. In this absorber 10D, the absorbent polymer is unevenly distributed on the side of the portion 9S in the longitudinal direction. This absorbent body 10D incorporates the portion 9L side in the longitudinal direction into the diaper toward the rear side (back side) of the wearer, so that urine is preferentially absorbed and held in the absorbent polymer on the ventral side. In addition, by increasing the thickness of the portion, it is possible to prevent the soft stool from flowing from the buttocks side over the crotch portion to the front side.

An absorbent body 10E shown in FIG. 16 has portions 9S in which short fibers are unevenly distributed at the center in the width direction of the absorbent core 9 made of the fiber assembly 93, and portions in which long fibers are unevenly distributed on both sides of the portion 9S. 9L.
The portion 9S in which the short fibers are unevenly distributed among the fiber aggregates 93 constituting the absorbent core 9 is such that the proportion of the short fibers having a fiber length of less than 70 mm in the constituent fibers is 50 to 100% on a weight basis. Preferably, it is 60 to 100%, more preferably 80 to 100%. In addition, the ratio (a more preferable ratio and a further preferable ratio are included) of this preferable short fiber is the part (center of the long fiber derived short fiber) in the long fiber web 12 of the absorbent body 10 shown in FIGS. The same applies to the portion located in the region M) and the absorbers 10C and 10D described above.
Further, in the fiber assembly 93, the long fiber is unevenly distributed, and the portion 9L that does not substantially contain the short fiber or contains only a small amount of the short fiber as compared with the portion 9S is the fiber length in the constituent fibers. The proportion of long fibers exceeding 70 mm is preferably 50 to 100% on a weight basis, more preferably 60 to 100%, still more preferably 80 to 100%.

  According to the absorber 10E shown in FIG. 16, the same effect as the absorber 10 shown in FIG.1 and FIG.2 mentioned above is show | played. Similarly to the absorbent body 104 described above, when it is incorporated in a diaper or the like with its longitudinal direction coinciding with the front-rear direction of the diaper, both sides thereof are raised toward the wearer's skin side by an elastic member. It is easy and a side leakage prevention wall can be formed easily. Elastic members for raising both side portions of the absorbent body 10E include the skin contact surface side, the non-skin contact surface side of the absorbent body 10E, the vicinity of the side edge of the absorbent body 10E, the inside of the absorbent body 10 and the like. Can be mentioned.

In the absorbent body 10F shown in FIG. 17, portions 9S in which short fibers are present are dispersed in the absorbent core 9 made of the fiber assembly 93. Due to the presence of a plurality of parts containing short fibers in a random or regular pattern, the parts containing short fibers absorb and swell quickly, and the swelling caused by the swelling causes a gap between the skin and the diaper after swelling. Good ventilation is maintained. As shown in FIG. 17 (b), a plurality of fibers can be used as shown in FIG. 17 (c) instead of scattering the portion 9S where the short fibers are present in the fiber assembly composed of a single layer. The absorbent core 9 can be constituted by the layers 91 and 92, and one layer 92 can be a layer mainly composed of long fibers, and the other layer 91 can be a layer mainly composed of short fibers composed of a large number of divided pieces. .
The portion 9S containing short fibers contains a large amount of absorbent polymer compared to the portion 9L containing only a small amount of short fibers. The absorptive polymer is present in a weight ratio of 9S / 9L = 10/1 to 1.5 / 1. Alternatively, it is preferable that the portion 9L containing only a small amount of short fibers does not substantially contain an absorbent polymer. “Substantially” refers to a state in which the amount of 9L of absorbent polymer is less than 1/10 compared to the amount of absorbent polymer contained in 9S, and the absorbency intended to be placed in the 9S portion during the manufacturing process. This includes the case where the polymer is unintentionally mixed in a small amount of the 9L portion.
By disposing the absorbent polymer in this way, the 9S portion is raised compared to the 9L portion, and air permeability can be ensured.

The short fibers in the absorbent bodies 10B to 10F are all synthetic or semi-synthetic fibers. Conventionally, pulp fibers have been widely used as the absorber, but by using short fibers that are not pulp fibers, there is no sag even when wet, and spot absorptivity can be ensured even for repeated absorption.
Synthetic fibers that can be used as short fibers include polyethylene, polypropylene, polyethylene terephthalate, polybutylene terephthalate, polytetramethylene terephthalate, nylon, acrylic fiber, vinylon, etc. alone or in combination (eccentric and concentric core-sheath type, side-by-side type) Examples of the semi-synthetic fiber that can be used as the short fiber include rayon, cellulose triacetate, and / or cellulose diacetate.
Synthetic and semi-synthetic fibers can be used individually or in combination of two or more of the above. The expression synthetic or semi-synthetic fiber includes the combined use of synthetic fiber and semi-synthetic fiber.

The absorbent bodies 10B to 10F are different from the absorbent body 10 of the first embodiment described above in that the short fibers contained therein are not produced by cutting the long fibers with massive particles.
The upper fiber layer 91 in the absorbent body 10B shown in FIG. 13 can be composed of a card web manufactured using a card machine, an airlaid web using air, a wet web using water, or the like. The fibers constituting the card web are already short fibers at the stage of raw cotton supplied to the card machine. On the other hand, the lower fiber layer 92 in the absorbent body 10B can be composed of a web obtained by opening a tow in the same manner as the above-described absorbent body manufacturing method. Moreover, it can also be comprised from the web obtained by tearing the web obtained by melt spinning, such as a spun bond, and the film which melt | dissolved and extruded and shape | molded (it extended | stretched as needed).

Fig.18 (a) is a figure which shows an example of the manufacturing method of the absorber 10B.
In the method shown in FIG. 18A, the short fibers 122A weighed by the hopper 94 are supplied to the card machine 95 to obtain a strip-shaped card web 91A, and the non-blocking absorbent polymer 13 is placed on the web 91A. After sprinkling on the portion, the long fiber web 12 obtained by opening the tow is stacked on the polymer spray surface of the web 91A, and then the laminate is inserted between a pair of rollers 96 and 96 to obtain a thickness. Pressurize in the direction. The pressurization by the pair of rollers 96 and 96 is performed under the condition that the thickness of the laminate is reduced and the shape retention is improved, but the long fibers are not substantially cut. After pressurization by a pair of rollers 96, 96, the lap sheet is supplied by a lap sheet supply mechanism (not shown) to cover the laminate, and then cut into a length corresponding to one absorber, thereby absorbing the above-described absorption. A large number of bodies 10B are obtained continuously.

  In the manufacturing method of this embodiment, the absorbent polymer 13 is supplied so as to be sandwiched between the card web 91A and the long fiber web 12. In the obtained absorbent body 10B, the thickness of the absorbent body is increased. In the direction, the absorbent polymer is unevenly distributed near the boundary between the upper absorbent layer 91 and the lower absorbent layer 92.

FIG.18 (b) is a figure which shows an example of the manufacturing method of absorber 10C-10F.
In the method shown in FIG. 18B, the web 12 of continuous fibers obtained by opening the tow is continuously conveyed, and the web 12 is overlaid on the stretchable sheet 14a. The non-blocking absorbent polymer 13 is spread on the top. Then, the web 12 on which the absorbent polymer 13 is dispersed is passed between a pair of rollers 97 and 97, and the absorbent polymer 13 is pushed into the web 12. Next, the web 12 in a state of being sandwiched between both the sheets 14a and 14b by stacking the extensible sheet 14b on the opposite side of the web 12 from the polymer spreading surface (the surface opposite to the sheet 14a side), The long fibers in the web 12 are partially cut through the long fiber cutting device 98.

The long fiber cutting device 98 is capable of cutting long fibers regardless of the presence or absence of massive particles. For example, the long fiber cutting device 98 includes a pressurizing unit having cutting protrusions on the peripheral surface or surface thereof. Can be used to cut the portion of the long fibers pressed by the cutting projections when pressed against the web 12 sandwiched between the sheets 14a and 14b. The long fiber cutting device 98 is preferably configured such that the elongated sheets 14a and 14b do not easily perforate the sheet even when pressed by the cutting protrusions.
FIG. 19 shows an example of the arrangement of the cutting projections of the cutting device 98 when the absorbent body 10E shown in FIG. 16 is manufactured, and is formed on the peripheral surface of the pressure roll (the surface of the pressure unit). The arrangement of the cutting projections is shown with the roll unfolded. As shown in FIG. 19, cutting projections are formed in a staggered arrangement at a portion 98M corresponding to the center portion in the width direction of the web 12. By pressing the web 12 with the portion 98M, the center of the web 12 is formed. A large number of short fibers can be produced in the region. On the other hand, the cutting projections are not formed on the portions 98S, 98S corresponding to both side portions of the web 12, and substantially no short fibers are generated in the left and right side regions of the web 12. The absorbers 10C, 10D, and 10F can be manufactured in the same manner except that the arrangement of the cutting protrusions formed on the surface of the pressure unit is changed.
Further, as still another embodiment of the absorbent body of the present invention, the scattering pattern of the massive particles in the production method shown in FIG. 4 is changed, and the range of the hatched portion in each figure of the absorbent body shown in FIGS. And an absorbent body in which short fibers derived from long fibers are produced.

FIG. 20 is a diagram showing a method for manufacturing an absorbent body according to still another embodiment of the present invention.
In the method shown in FIG. 20, the long fiber web 12 obtained by opening the tow is supplied to a long fiber cutting device 99, and the long fiber is partially cut by the cutting device 99. After partially producing short fibers derived from the fibers, the web composed of the short fibers and the uncut long fibers is pulled by the web according to the speed ratio between the pair of rolls 310, 311 and the cutting device 99. Stretch. At this time, incompletely cut fibers are cut to form short fibers. Next, the stretched state of the web is relaxed between the pair of rolls 310, 311 and the vacuum conveyor 32, and the absorbent polymer 13 is sucked onto the relaxed web from the opposite side by the vacuum conveyor 32. Supply. Then, a lap sheet is supplied by a wrap sheet supply mechanism (not shown) to cover the laminate, and then cut into a length corresponding to one absorbent body.
The cutting device 99 can be used without particular limitation as long as it can cut the fiber. For example, a rotary die cutter, a push cutting blade, or a laser can be used.

According to this production method, an absorbent body comprising a fiber assembly including long fibers and short fibers derived from long fibers, in which long fibers and short fibers are mixed, is obtained.
In the present invention, in the fiber assembly containing short fibers or the long fiber web, it is preferable that the constituent fibers are not bonded to each other because the swelling of the absorbent polymer is not inhibited. Here, “bond” refers to a state in which the fibers are fused and integrated, and the bonds cannot be removed even by swelling of the water-absorbing polymer, and the fibers are entangled and caught by each other or a water-soluble binder. The state in which the fibers are stuck and loosened or detached due to excretion, and the fibers can move due to swelling of the water-absorbing polymer is not included in the “bonding”.

As mentioned above, although preferable embodiment of this invention was described, this invention can be changed suitably.
For example, the long fiber web containing the short fiber derived from the long fiber and the absorbent polymer may be laminated with a piled product containing fluff pulp. For example, the absorbent body shown in FIGS. 1 and 2 and the long fiber web 12 in the absorbent body shown in FIG. 6 are laminated on a piled product containing fluff pulp, and the whole is covered with a wrap sheet to form an absorbent body. You can also. Such an absorbent body is preferably used by being incorporated into an absorbent article so that the long fiber web 12 is located on the skin side of the wearer. The 1st absorption core 141 in the absorber 104 mentioned above consists of a piled thing containing a fluff pulp.

  As the piled product containing fluff pulp, the piled product only of flap pulp, the mixed product of fluff pulp and absorbent polymer particles, fluff pulp and heat-fusible synthetic fiber were mixed and integrated by heat treatment Mixed fibres, fluff pulp, mixed fibres made by mixing heat-fusible synthetic fibers with absorbent polymer particles and heat treatment, and fluff pulp fibres embossed and embossed A mixed product of fluff pulp and absorbent polymer particles, a mixed product of fluff pulp subjected to water spraying treatment and absorbent polymer particles, and the like can be used. Content of the flap pulp in the fiber pile containing a fluff pulp can be 50-100 mass%, for example.

  Further, as in the absorbent body 10A shown in FIG. 7, instead of folding both sides of a wide web into a two-layered web, a long-fiber web cut into a short part by cutting a part thereof, It is also possible to form a two-layer absorbent body by laminating a web of long fibers not shortened.

The absorbent article of the present invention may include the above-described other absorbent body instead of the above-described absorbent body 104. Further, instead of the pants-type disposable diaper, an unfolded disposable diaper may be used. Further, the absorbent body of the present invention may be disposed between an absorbent body having a general configuration in a conventional disposable diaper or the like and a top sheet, and used as a so-called sublayer or second sheet.
The absorptive article of the present invention provided with the absorber of each above-mentioned embodiment may have two or more sets of a pair of solid gathers which counter mutually. For example, as shown in FIG. 11, the elastic strands 221 extending in the longitudinal direction of the absorbent article are arranged in the stretched state on the side edges of the leg fluffs 220 extending laterally from the side edges of the absorbent body 201. 222, and further, a first three-dimensional gather 223 and a second three-dimensional gather 224 having a base end portion are disposed between the leg gather 222 and the side edge of the absorbent body 201. The first three-dimensional gather 223 is arranged closer to the leg gather, and the second three-dimensional gather 224 is arranged closer to the absorber.

  These three gathers located on the leg flap 222 adjust the contraction force of each gather so that the contraction force of the outermost gather is larger than the contraction force of the gathers located inward. It is preferable. That is, when the contraction force of the leg gather 222 is L1, the contraction force of the first three-dimensional gather 223 is L2, and the contraction force of the second three-dimensional gather 224 is L3, it is preferable that L1> L2, L3. In particular, it is preferable that the gather contraction force gradually decreases from the outermost gather to the inside. That is, it is preferable that L1> L2> L3. The reason is as follows.

  The conventional design method for absorbent articles is to reduce the thickness of the absorbent article and make it difficult to leak liquids, thereby increasing the shrinkage force of gathers and leaving a gap between the wearer's body and the absorbent article. Based on the idea of not. However, if the contraction force of the gathers is too strong, the marks are likely to touch the skin. In addition, when the thin and flexible or absorbent body is used as in the present invention, the absorbent article contracts due to the contraction force of the gathers, making it difficult to wear. If the gather contraction force is too strong, a downward force due to the contraction force acts on the absorbent article during mounting of the absorbent article, and a shift tends to occur. On the other hand, by using two or more pairs of leg gathers and a pair of opposing three-dimensional gathers and having the contraction force as described above, the above-described inconveniences that occur in conventional absorbent articles can be avoided.

  The gather contraction force is measured by the following method. A gather is cut from the absorbent article and used as a measurement sample. A hysteresis curve of the measurement sample is drawn using Tensilon ORIENTEC RTC-1150A. The stress at the return of this hysteresis curve is defined as the contraction force. The speed of pulling and returning is 300 mm / min. The initial length of the sample is 100 mm, and the maximum elongation is 100 mm (twice the original length). The stress at the time of return of the hysteresis curve is a measured value when the sample is returned 50 mm from the maximum elongation. The measurement is an average of 5 points. In the case of a sample whose maximum elongation is less than 100 mm, the elongation is up to 50 mm, and the value at that time is the measured value.

  In order to adjust the contraction force of each gather, for example, methods such as changing the thickness of the elastic body, changing the elongation rate of the elastic body, changing the number of elastic bodies, etc. are used alone or in combination. Moreover, it is preferable that the stretchable region of the leg gathers 22 is only the crotch part of the absorbent article.

In the absorbent article shown in FIG. 11, two sets of leg gathers and a pair of opposing three-dimensional gathers are used. Instead of this, in the absorbent article of the present invention including the absorbent body of each embodiment, two or more pairs of opposing three-dimensional gathers may be used without using leg gathers. For example, in FIG. 12, two sets of three-dimensional gathers, a first three-dimensional gather 223 and a second three-dimensional gather 224, are used. Also in this case, it is preferable that the shrinkage force of the three-dimensional gather is gradually reduced from the outer side in the width direction toward the inner side for the same reason as described above.
The description omitted in one embodiment described above and the requirements of only one embodiment can be applied to other embodiments as appropriate, and the requirements in each embodiment can be appropriately changed between the embodiments. Can be substituted.

[Example 1]
First, a crimped acetate long fiber tow was prepared. The fiber diameter of this long fiber was 2.1 dtex. The total fiber content of tow was 25,000 dtex. This tow was conveyed under extension and opened using an air opening device to obtain an opening web. Next, the web was wound through a spread web between a roll in which a large number of disks were incorporated around the axis at predetermined intervals and a smooth receiving roll. Thereafter, the width was adjusted to 100 mm, and the transfer speed was reduced and transferred onto a vacuum conveyor. The tension of the web on the vacuum conveyor was relaxed to cause crimps. The crimp ratio of the fibers in the web was 30%, and the number of crimps per 1 cm was 15. This widened the space between the long fibers, made it easier for the absorbent polymer to enter, and increased the thickness of the web to improve the embedding supportability of the absorbent polymer. An absorbent polymer having a width of 80 mm was spread on the web, and the absorbent polymer was embedded and supported in the spread web. The basis weight of the web was 25 g / m ² and the basis weight of the absorbent polymer was 132 g / m ² .

Next, 100 parts by weight of the opened fluff pulp and 100 parts by weight of the absorbent polymer are uniformly mixed in an air stream and stacked on a T-shaped mold to obtain a total weight of 300 g / m ² . Got. The T-shaped mold had a leg width of 100 mm, a length of 100 mm, a horizontal frame width of 125 mm, and a length of 100 mm. The basis weights of the fluff pulp and the absorbent polymer in the piled body were 150 g / m ² , respectively. The web was layered on the piled fiber, and the whole was wrapped with a tissue paper having a basis weight of 16 g / m ² spray-coated with a hot melt adhesive. Thereafter, compression is performed between a metal roll and a rubber roll (the clearance between the two rolls is set to 0 mm), and the web and tissue paper are integrated, and the web is compressed, and the constituent fibers of the web are compressed by the absorbent polymer. The absorbent body was obtained by cutting.
This web (fiber aggregate or long fiber web) contained a massive absorbent polymer and short fibers, and they were distributed in the form shown in FIG. 6 (d).
The distribution of short fibers in the absorbent body was unevenly distributed in the widthwise central portion 80 mm (position where the absorbent polymer was dispersed). The existence ratio of short fibers in the central region in the web width direction was 86% (long fibers were 14%), and the existence ratio of short fibers at both ends in the web width direction was 18%.

(Measurement method of fiber part)
In the vicinity of the center in the longitudinal direction of the absorbent body, 100 fibers were randomly drawn from the skin contact surface, and the fiber length was measured according to the average fiber length measurement method (Method C) of JIS L1015. A histogram was created from the obtained measurement data, and the proportion of fibers having a fiber length of less than 70 m was calculated as the proportion of short fibers.

[Example 2]
The disperse position of the absorbent polymer on the web in Example 1 was intermittently sprinkled in the longitudinal direction (spread with a width of 80 mm in the center in the width direction from the position of 100 mm to the position of 350 mm from the front side in the longitudinal direction). That is, the absorbent polymer was embedded and supported in the spread web in the same manner as in Example 1 except that the spray area was 80 mm wide and 250 mm long. Next, the opened fluff pulp was stacked on a T-shaped mold to obtain a stacked body having a basis weight of 100 g / m ² . The T-shaped mold is the same as that in the first embodiment. A web was piled on the piled fiber, and the whole was hydrophilized and wrapped using a spunbond-meltblown-meltblown-spunbond nonwoven fabric (SMMS) having a basis weight of 16 g / m ² to obtain an absorbent body. The absorbent body is compressed between a metal roll and a rubber roll in the same manner as in Example 1, and the constituent fibers of the web are cut with an absorbent polymer as the web is compressed.
This web (fiber aggregate or long fiber web) contained a massive absorbent polymer and short fibers, which were distributed in the form shown in FIG. 6 (a).
The short fibers in the absorbent body were 78% (22% long fibers) at the position where the absorbent polymer was dispersed, and 12% in the non-polymer-spreading area.

Example 3
A web P1 in which the same absorbent polymer as that used in Example 1 was embedded and supported was prepared. Next, a composite fiber (3.3 dtex, 51 mm cut, the fiber surface is hydrophilicized on the fiber surface and treated with a surfactant to suppress the generation of static electricity) is formed of polypropylene having a core and polyethylene having a sheath. A web was formed (P2) so that the basis weight was 30 g / m ^{2 over the} card. The obtained synthetic fiber web P2 was overlaid on the web P1 in which the absorbent polymer was embedded and supported.

Next, a T-shaped mold was prepared by uniformly mixing 100 parts by weight of fluff pulp and 100 parts by weight of an absorbent polymer on a tissue paper having a basis weight of 16 g / m ² spray-coated with a hot melt adhesive. A stacked fiber body having the total basis weight of 300 g / m ² (same as that used in Example 1) obtained by stacking fibers was stacked.
Furthermore, the above-mentioned laminate of P1 and P2 was stacked, and a tissue paper having a basis weight of 16 g / m ² spray-coated with a hot melt pressure-sensitive adhesive was stacked on top to wrap the whole.
The distribution of short fibers in the absorbent body is 100% of the short fibers on the skin side in the thickness direction, and 4% of the short fibers on the back material side in the web thickness direction (those that were cut unintentionally in the processing step) It was thought).

[Comparative Example 1]
100 parts by weight of the opened fluff pulp and 100 parts by weight of the absorbent polymer were uniformly mixed in an air stream to obtain a piled product having a total basis weight of 520 g / m ² . The basis weights of the fluff pulp and the absorbent polymer were 260 g / m ² , respectively. The obtained fiber stack was wrapped with tissue paper having a basis weight of 16 g / m ² to obtain an absorbent body. A hot melt pressure-sensitive adhesive 5 g / m ² was spray-coated between the stacked fiber and the tissue paper, and both were adhered. Except these, it carried out similarly to Example 1, and obtained the absorber.

[Comparative Example 2]
In the same manner as in Comparative Example 1, 100 parts by weight of the opened fluff pulp and 100 parts by weight of the absorbent polymer were uniformly mixed in an air stream to obtain a piled body having a total basis weight of 300 g / m ² . The basis weights of the fluff pulp and the absorbent polymer were 150 g / m ² , respectively. Other than that was carried out similarly to the comparative example 1, and obtained the absorber. Except these, it carried out similarly to Example 1, and obtained the absorber.

[Comparative Example 3]
In Example 1, an absorbent body was prepared in the same manner as in Example 1 except that compression with a roll, that is, fiber cutting was not performed.

[Performance evaluation]
The absorption capacity of the absorbers obtained in Examples and Comparative Examples was measured by the following methods, and the structural stability and flexibility were evaluated. The results are shown in Table 1 below.

[Absorption capacity]
The obtained absorbent body is fixed to a 45 ° inclined plate, and a certain amount of physiological saline is repeatedly injected into the position 200 mm from the upper end of the absorbent body at regular intervals, and the lower end of the absorbent body The amount of injection until leakage from the part was compared. The relative value when the absorption capacity of Comparative Example 1 was 1.0 was calculated using the following formula.
Absorption capacity (relative value) = (absorption capacity of sample) / (absorption capacity of comparative example 1)

[Structural stability]
(1) At the time of drying The center part of the absorber produced to 100x200 mm was cut | disconnected, and the absorber of 100x100 mm was obtained. The amount of polymer dropped from the cut surface was measured when the vibration was applied 20 times at a speed of 1 cm / second with an amplitude of 5 cm with the cut surface directly below. The absorbability of the absorbent polymer was evaluated according to the following criteria.
Of the mixed absorbent polymers
(Circle): The ratio of the absorptive absorbent polymer is 10% or less.
(Triangle | delta): The quantity of the absorptive polymer which dropped out exceeds 10% and is 25% or less.
X: The amount of the absorbent polymer that has dropped off exceeds 25%.
(2) When wet The surface of the absorber cut to 100 × 200 mm was almost uniformly absorbed with 200 g of physiological saline, and then it was visually determined whether the absorber would not be destroyed when the absorber was gently lifted. Further, the weight of the dropped absorbent polymer is measured, and the weight at the time of drying of the dropped absorbent polymer is calculated by dividing by the centrifugal retention amount per unit weight of the dropped absorbent polymer measured separately. Furthermore, the ratio of the absorbent polymer that has dropped out is calculated from the relationship with the blending amount of the absorbent polymer. In addition, the amount of the absorbent polymer blended is such that the absorbent to be analyzed whose weight has been measured in advance is immersed in an aqueous solution of ascorbic acid and exposed to sunlight for a sufficient time to completely decompose the absorbent polymer. Washing with water and decomposition are repeated, the absorbent polymer is completely dissolved and then dried, and the amount of the absorbent polymer blended can be estimated from the difference in the weight of the absorbent before the decomposition.
A: The ratio of the absorbent polymer that has fallen off is 10% or less, and the absorber is not destroyed.
(Triangle | delta): The ratio of the absorptive absorbent polymer exceeds 10% and is 25% or less, and there is no destruction of an absorber.
X: The proportion of the absorbent polymer dropped off exceeds 25%, or the absorber is destroyed.

[Flexibility]
The flexibility of the absorber was evaluated using a handleometer. The measured value of the handleometer indicates that the smaller the value, the better the ease of wearing and the better the fit. The measurement method using the handle-o-meter is as follows. Measurement is performed according to JIS L1096 (flexibility measurement method). An absorbent body cut by 150 mm in the longitudinal direction and 50 mm in the width direction is arranged in a direction orthogonal to the groove on a support base in which a groove having a width of 60 mm is carved. The force required when the center of the absorber is pushed by a blade having a thickness of 2 mm is measured. The apparatus used in the present invention is a texture testing machine (handle-of-meter method), HOM-3 type, manufactured by Daiei Kagaku Seiki Seisakusho. The average value of the three points is taken as the measured value. Based on the measured values obtained, the flexibility was evaluated according to the following criteria.
○: The measured value of the handle-o-meter is 2N or less.
(Triangle | delta): The measured value of a handle ohm meter exceeds 2N and is 4N or less.
X: The measured value of the handle o meter exceeds 4N.

[Diffusion anisotropy]
In the plane of the absorber, the shape of diffusion when the liquid was injected from the central portion of the absorber was evaluated by the difference in distance between the major axis side and the minor axis side. The liquid was injected by injecting a predetermined amount (40 g / time, 5 g / sec), and measuring the length of the long axis side and the short axis side of the diffusion area 5 minutes after the completion of absorption.
Moreover, when the diffusivity was different between the skin contact surface and the inside of the absorber or between the absorber central portion and the absorber short portion, both values were measured.
Based on the measured values having the most different diffusivity among the obtained measured values, the determination was made based on the following criteria.
○: The ratio of the length of the diffusion area between the major axis side and the minor axis side is 1.5 or more on the major axis side / minor axis side. Δ: Ratio of the length of the diffusion area between the major axis side and the minor axis side. However, the ratio of the length between the major axis side and the minor axis side of the diffusion area is 1.0 or more on the major axis side / minor axis side. Less than 2

As mentioned above, it turns out that the absorber of an Example has a diffusion anisotropy, or is an absorber which has a part from which a diffusivity differs, respectively.

It is a perspective view showing an embodiment of an absorber of the present invention partially fractured. It is a schematic cross section which shows the II-II line cross section of the absorber of FIG. It is explanatory drawing (schematic top view) explaining the effect of the absorber of FIG. It is a perspective view which shows typically the process by one Embodiment of the manufacturing method of the absorber of this invention with an apparatus. It is a conceptual diagram which shows a mode that a long fiber is cut | disconnected with an absorptive polymer. It is a schematic plan view which shows other embodiment of the absorber of this invention. It is sectional drawing (FIG. 2 equivalent view) which shows other embodiment of the absorber of this invention. It is an expansion | deployment top view which shows the disposable diaper (one Embodiment of the absorbent article of this invention) using further another embodiment of the absorber of this invention. It is a schematic cross section which shows the II cross section of FIG. It is a schematic cross section which shows the III-III line cross section of FIG. 8 in use condition. It is a schematic diagram which shows the cross-sectional structure of the width direction in other embodiment of the absorbent article of this invention. It is a schematic diagram (corresponding to FIG. 11) showing a cross-sectional structure in the width direction in still another embodiment of the absorbent article of the present invention. It is a figure which shows other embodiment of the absorber of this invention, (a) is a top view, (b) is the IV-IV sectional view taken on the line of (a). It is a figure which shows other embodiment of the absorber of this invention, (a) is a top view, (b) is the VV sectional view taken on the line of (a). It is a figure which shows other embodiment of the absorber of this invention, (a) is a top view, (b) is the VI-VI sectional view taken on the line of (a). It is a figure which shows other embodiment of the absorber of this invention, (a) is a top view, (b) is the VII-VII sectional view taken on the line of (a). It is a figure which shows other embodiment of the absorber of this invention, (a) is a top view, (b) is a VIII-VIII sectional view taken on the line of (a). It is a figure which shows the further example of the manufacturing method of the absorber of this invention. It is an expansion | deployment top view of a pressure roll which shows the example of arrangement | positioning of the processus | protrusion for cutting used for the manufacturing method shown in FIG.18 (b). It is a figure which shows the manufacturing method of the absorber of other embodiment of this invention. It is explanatory drawing of the evaluation method of the shape of a fiber cross section.

Explanation of symbols

10, 10A to 10F, 104, 201 Absorber 11 Absorbent core 12 Long fiber web 121 Long fiber 122 Short fiber derived short fiber 13 Absorbent polymer 14 Wrap sheet 101 Disposable diaper (absorbent article)

Claims (15)

An absorbent body having a long fiber web obtained from tow and agglomerated particles contained in the web,
At least a portion of the range the particles in the planar direction of the web are distributed, the long fibers forming the web has occurred is disconnected, absorber numerous short fibers are synthetic or semi-synthetic fibers are present . The absorber according to claim 1, wherein the plurality of short fibers are mixed with the long fibers .   The absorbent body according to claim 1 or 2, wherein the long fibers and the short fibers are unevenly distributed in different portions in a planar direction or a thickness direction of the absorbent body. Containing absorbent polymer, the absorbent polymer, absorbent body according to any one of claims 1 to 3 is unevenly distributed to a particular site in the planar direction or thickness direction of the absorbent body. The absorbent body according to any one of claims 1 to 4, wherein the massive particles are unevenly distributed in a part of a planar direction or a thickness direction of the absorbent body. Particles of the bulk are localized in specific sites in the planar direction or thickness direction of the absorber,
The particles, absorbent body according to any one of claim 1 to 5 are present in the same site as the short fibers. The absorber according to any one of claims 1 to 6 , wherein the particle is an absorbent polymer. The absorbent according to any one of claims 1 to 7, wherein the short fibers have a fiber strength of 3 g / d or less. The absorbent body according to any one of claims 1 to 8, wherein the short fiber has a different cross-sectional shape at the end of the fiber and a cross-sectional shape at the center of the fiber. In the planar direction of the absorbent body, the range in which the particles are distributed and the range in which the short fibers are generated coincide with each other, or the range in which the short fibers are generated is included in the range in which the particles are distributed. The absorber according to any one of claims 1 to 9 . The web of the long fibers containing lumps like particles, absorbent body according to any one of claim 1 to 10 fiber aggregate constituting the fiber consists only of short fibers are further laminated.   The absorbent body according to claim 11, wherein the fiber assembly in which the constituent fibers are composed of only short fibers further contains an absorbent polymer. Mass shaped in the web in the long fibers containing particles, absorbent body according to any one of claim 1 to 12, constituting fibers is not bonded. It is a manufacturing method of an absorber given in any 1 paragraph of Claims 1-13 ,
After spraying the lump particles of the hydrophilic long fiber web, press at least a part of the range in which the particles are sprayed in the thickness direction, and press the long fibers in the part against the particles to cut them. It comprises a method of manufacturing an absorbent body. An absorbent article comprising an absorbent body according to any one of claims 1 to 1 3,
The absorbent article in which the said short fiber exists in the site | part arrange | positioned facing a wearer's excretion part at the time of wear.

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