JP4646830B2 - Absorbent articles - Google Patents

Description

  The present invention relates to absorbent articles such as disposable diapers, sanitary napkins, and incontinence pads.

  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, and the wearing feeling of the absorbent article is lowered.

  Also, it is known that the water-absorbing core is composed of an upper layer, a lower layer and an absorbent layer located between both layers, and a fiber layer made of acetate fiber tow is disposed on the spray layer of the superabsorbent polymer as the absorbent layer. (See Patent Document 2). A part of the superabsorbent polymer is bonded to the lower layer by an adhesive, and another part is housed in the fiber layer of the tow. In this water-absorbent core, although a part of the superabsorbent polymer is accommodated in the fiber layer of the tow, most of the superabsorbent polymer is bonded to the lower layer. That is, a fiber layer of tow and a spray layer of superabsorbent polymer exist separately. As a result, when the water absorbing core is deformed during wearing of the absorbent article due to the wearer's movement, the structure is easily broken.

  As an absorption layer having a continuous filament tow, one in which the tow extends in the thickness direction of the absorption layer is also known (see Patent Document 3). According to Patent Document 3, the excrement moves from the top to the bottom through the gap between the fibers of the tow and can be separated from the wearer's skin, so that it does not cause stuffiness or rash. Has been. In order for this absorption layer to have such a structure, the length of the tow needs to be long to some extent. Therefore, the absorption layer becomes thick.

JP-A-57-160457 Special table 2004-500165 gazette JP 2001-276125 A

  Therefore, the objective of this invention is providing the absorbent article which can eliminate the fault which the prior art mentioned above has.

  The present invention includes an absorbent body having a hydrophilic long-fiber web, and a superabsorbent polymer having a liquid flow rate of 30 to 300 ml / min under a load of 2.0 kPa is contained in the web. The object is achieved by providing an absorbent article in which the weight ratio of the superabsorbent polymer to the long fibers (superabsorbent polymer / long fibers) in the absorbent body is 2 or more. .

Further, the present invention has an absorbent body having a hydrophilic long fiber web, and the web contains a superabsorbent polymer, and the superabsorbent polymer was measured by the following method. The object is achieved by providing an absorbent article having a measure of affinity with pulp of 0.3 to 0.9.
[Measure of affinity with pulp]
1.0 g of the superabsorbent polymer is uniformly dispersed in a circle having a radius of 5 cm from the center on the filter paper (Advantech Toyo 4A 185 mm). Thereafter, in order to swell the superabsorbent polymer, 50 g of 0.9 wt% NaCl aqueous solution is uniformly applied in the circle, and after 1 minute from the completion, the polymer spray surface of the filter paper is directed downward. The affinity with the pulp is obtained by the following equation by measuring the amount A of the dropped polymer and the amount B of the polymer adhering to the filter paper without falling off.
Affinity with pulp = B / (A + B)

  According to the absorbent article of the present invention, gel blocking of the superabsorbent polymer due to absorption of body fluid is prevented, and the speed of absorbing liquid from the topsheet is improved. Further, the liquid once absorbed by the absorber does not easily return, that is, wetback occurs. Furthermore, the gel feeling that is likely to occur due to the absorbed superabsorbent polymer is suppressed, and the feel is improved.

  Hereinafter, the present invention will be described based on preferred embodiments thereof. The absorbent article of the present invention is mainly used for absorbing and holding excretory body fluids such as urine and menstrual blood. The absorbent article of the present invention includes, for example, disposable diapers, sanitary napkins, incontinence pads, etc., but is not limited thereto, and widely includes articles used for absorbing liquid discharged from the human body. .

  The absorbent article of the present invention typically includes a top sheet, a back sheet, and a liquid-retaining absorbent disposed between both sheets. As the top sheet and the back sheet, materials usually used in the technical field can be used without particular limitation. For example, as the surface sheet, liquid permeable sheets such as various nonwoven fabrics and perforated films subjected to a hydrophilic treatment can be used. As the back sheet, a liquid-impermeable or water-repellent sheet such as a thermoplastic resin film or a laminate of the film and a nonwoven fabric can be used. The back sheet may have water vapor permeability. The absorbent article may further include various members depending on the specific application of the absorbent article. Such members are known to those skilled in the art. For example, when applying an absorbent article to a disposable diaper or a sanitary napkin, a pair or two or more pairs of three-dimensional guards can be disposed on the left and right sides of the topsheet.

  FIG. 1 schematically shows the cross-sectional structure of the absorbent body in the absorbent article of the present embodiment. The absorbent body 10 shown in the figure has a single-layer structure of a long fiber web (hereinafter referred to as a web) 20. The web 20 contains a superabsorbent polymer 21. The superabsorbent polymer 21 is uniformly embedded and supported in the web 20.

  The long fiber is preferably hydrophilic. What is used in the present invention as a long fiber having hydrophilicity is a long fiber that is inherently hydrophilic, and inherently has no hydrophilicity, but is hydrophilic by being subjected to a hydrophilic treatment. Both of the long fibers to which is given are included. Preferred long fibers are inherently hydrophilic long fibers, and particularly preferred are acetate and rayon long fibers. In particular, acetate is particularly preferable because it retains bulkiness even when wet. As the acetate, cellulose triacetate and cellulose diacetate are preferable.

  The absorbent body 10 shown in FIG. 1 is characterized by a superabsorbent polymer 21 contained therein. The superabsorbent polymer 21 is characterized by a high liquid passing rate under load. The liquid flow rate is measured by applying a load under a state where the superabsorbent polymer is sufficiently absorbed and saturated. Accordingly, the high liquid passing speed means that the passage of the liquid is hardly hindered even when pressure is applied in a state where the superabsorbent polymer absorbs liquid and is saturated. Therefore, using a superabsorbent polymer with a high liquid flow rate means that even if the absorbent body of the absorbent article that has repeatedly absorbed the liquid is subjected to the body pressure of the wearer, gel blocking of the superabsorbent polymer will not occur. Hard to happen. Gel blocking of the superabsorbent polymer reduces the rate at which bodily fluids are absorbed from the topsheet. That is, gel blocking of the superabsorbent polymer means that a body fluid exists between the skin and the surface sheet for a long time. That is, it causes skin irritation, urine leakage, a decrease in the liquid absorption capacity of the absorber, and wetback.

  From the viewpoint of effectively preventing gel blocking of the superabsorbent polymer, in the present embodiment, the superabsorbent polymer has a liquid flow rate value of 30 to 300 ml / min, preferably 32 to 200 ml / min, more preferably. The thing of 35-100 ml / min is used. When the value of the liquid flow rate is less than 30 ml / min, the superabsorbent polymers saturated and swollen by the liquid absorption adhere to each other under load, and the passage of the liquid is hindered, so that gel blocking easily occurs. The larger the value of the flow rate, the better from the viewpoint of preventing the occurrence of gel blocking. 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 once, or in the case of older infants or adults. When the excretion rate is high as described above, the liquid may not be sufficiently fixed and leakage may occur when the absorber is further thinned. In general, increasing the liquid flow rate increases the degree of crosslinking of the superabsorbent polymer, lowering the absorption capacity per unit weight of the superabsorbent polymer, and a large amount of superabsorbent polymer must be used. I must. From these viewpoints, the upper limit value of the flow rate is determined.

  A superabsorbent polymer 21 having a high flow rate in the above-mentioned range has been conventionally known. However, in a conventional absorbent article having an absorbent body mainly composed of pulp, since the pulp is interposed between the superabsorbent polymers, even if the superabsorbent polymer 21 swells sufficiently due to the absorption of the body fluid. The pulp prevents gel blocking and acts as a body fluid passage. In addition, if the pulp forms the skeleton of the absorbent core, it will not be crushed even if body pressure is applied, so that the pressure as high as body pressure is not applied to the superabsorbent polymer present in the absorbent core. Therefore, in the conventional absorbent article provided with the absorber mainly composed of pulp, it has not been considered necessary to have physical properties as high as the superabsorbent polymer 21 having a high liquid passing rate in the above range. That is, the superabsorbent polymer 21 having a high liquid passing speed in the above range exhibits its effect in the absorbent body 10 combined with the long fiber web 20.

  In order to obtain the superabsorbent polymer 21 having a liquid passing speed in the above-mentioned range, for example, the crosslink density inside and on the surface of the superabsorbent polymer is adjusted, the crosslink density is provided with a gradient, or the particle surface is inorganic. Various methods are known such as adding a substance and adjusting the particle shape of the superabsorbent polymer. In order to obtain the superabsorbent polymer 21 having a desired liquid flow rate, a reversed-phase suspension weight using an anionic surfactant described in Japanese Patent No. 2721658, which is a previous application of the present applicant, as a dispersant. A combination method may be used, or another method such as an aqueous solution polymerization method may be used.

  The measurement of the flow rate of the superabsorbent polymer 21 is performed under a 2.0 kPa load. This load substantially corresponds to the body pressure applied to the absorbent body while wearing the absorbent article. A specific method for measuring the flow rate is described in paragraph 0005 of Japanese Patent Laid-Open No. 2003-235889, for example. In the present invention, measurement is performed by changing 0.200 g, which is the weight of the sample used in the measurement method described in this publication, to 0.32 g. Specifically, the flow rate is measured by the following procedure.

[Measurement method of flow rate]
The gel flow rate is a filtration cylinder having a vertically arranged cylinder (inner diameter: 25.4 mm) and a narrow tube (inner diameter: 4 mm, length: 8 cm) with a wire mesh (aperture: 150 μm) and a cock (inner diameter: 2 mm) at the lower end of the opening. In the tube, with the cock closed, 0.32 g of a measurement sample adjusted to a particle size of 850 to 150 μm was poured, 50 ml of physiological saline was poured, and after standing for 30 minutes, a wire mesh (mesh opening 150 μm , 25 mm diameter) load (21.2 g) was inserted into the filtration cylinder so that the wire mesh and measurement sample were in contact, and after 1 minute, the weight (77.0 g) was placed on the wire mesh load and allowed to stand for 1 minute. Then, the cock is opened, and the time (T1) (seconds) until the liquid level of 0.9 wt% physiological saline reaches the 20 ml scale line from the 40 ml scale line is obtained from the following formula { (T0) It is the time when there is no constant sample}.
Flow rate (ml / min) = 20 × 60 / (T1-T0)

  A more detailed method for measuring the flow rate is described in paragraphs 0008 and 0009 of the above publication. The measuring apparatus is described in FIGS. 1 and 3 of the publication.

  Since the superabsorbent polymer 21 has a liquid passing speed in the above range, gel blocking is unlikely to occur even when a large amount thereof is blended in the web 20. Being able to mix the superabsorbent polymer 21 in the web 20 in a large amount is advantageous in that the liquid absorption capacity of the absorbent body 10 can be improved. From this viewpoint, in the absorbent body 10, the weight ratio of the superabsorbent polymer to the long fibers (superabsorbent polymer / long fibers) is set to 2 or more, preferably 3 or more. The weight ratio is not particularly limited, but if it is 5 or more, particularly about 10, the liquid absorption capacity of the absorbent body 10 can be sufficiently increased.

  Even in an absorbent body of a conventional absorbent article, it was possible to retain a large amount of superabsorbent polymer by increasing the amount of fiber material. However, in this case, the basis weight and thickness of the absorber are increased. On the other hand, in the present invention, it is easy to relatively increase the amount of the superabsorbent polymer 21 with respect to the amount of the web 20 that is a fiber material. This is very advantageous in that the liquid absorption capacity can be improved without increasing the thickness of the absorber 10. The upper limit of the weight ratio of the superabsorbent polymer 21 to the long fibers is determined from the viewpoint of extreme movement of the superabsorbent polymer 21 and prevention of falling off. Although depending on the presence / absence of crimping of the long fibers and the degree of crimping, if the upper limit is about 10, even if the wearer performs a violent operation, the superabsorbent polymer is unlikely to move or fall off.

  The superabsorbent polymer 21 having a liquid passing speed in the above range preferably has a high initial absorption speed measured according to JIS K7224 (VORTEX method). The liquid flow rate is measured under a state where the superabsorbent polymer is sufficiently absorbed and saturated, and a superabsorbent polymer having a high absorption rate is used even in the initial state where the liquid is not absorbed. As a result of the study by the present inventors, it has been found that the absorption rate of the absorbent body having a long fiber web is further increased. At the same time, it has been found that gel blocking of the superabsorbent polymer is less likely to occur, and that the feel of the absorbent body after liquid absorption is improved.

  The initial absorption rate measured according to the above method means that the smaller the value, the higher the liquid absorption rate. When the initial absorption rate of the superabsorbent polymer 21 is preferably 45 seconds or less, more preferably 35 seconds or less, the absorbent article has a sufficiently satisfactory performance, specifically, the liquid absorption rate is high and the gel blocking is high. An absorbent article having an absorbent body that hardly occurs is obtained.

  In order to prepare the superabsorbent polymer having the initial absorption rate, for example, an anionic surfactant described in Japanese Patent No. 2721658 according to the earlier application of the applicant described above was used as a dispersant. A reverse phase suspension polymerization method may be used, or synthesis may be performed using an aqueous solution polymerization method.

  In addition, as a method for evaluating the initial absorption rate of the superabsorbent polymer, the DW method is known in addition to the above-mentioned VORTEX method. Among these, considering that the absorbent body in the absorbent article of the present invention includes a superabsorbent polymer and a long fiber web, the initial absorption of the superabsorbent polymer is more in accordance with the VORTEX method than in the DW method. It is appropriate to evaluate the speed.

  Apart from the superabsorbent polymer 21 described above, in the present invention, the superabsorbent polymer 21 has an affinity scale of 0.3 to 0.9, preferably 0, as measured by the following method. .4 to 0.8, more preferably 0.5 to 0.7 can be used. This numerical value takes a value from 0 to 1, and the larger the value, the lower the affinity with the pulp. As is clear from the following measurement method, the low affinity with the pulp means that the superabsorbent polymer 21 is difficult to adhere to the pulp. That the scale of affinity with pulp is in the above range means that in the present invention, it is advantageous to use the superabsorbent polymer 21 having low affinity with pulp. Since such a superabsorbent polymer 21 is difficult to adhere to each other even if the liquid is absorbed, in the absorbent body 10 in the liquid-absorbed state, there is little free water (pore water) between the polymers. ing. Therefore, even if the wearer's body pressure is applied to the absorbent body 10, a space where the free water (gap water) can be released in the lateral direction (plane direction) of the absorbent body 10 is maintained between the polymers. As a result, the liquid from the absorbent body 10 does not easily reverse, that is, wetback occurs, and the skin contact surface of the absorbent article has a dry feeling. In order to obtain the superabsorbent polymer 21 having the above-mentioned range of affinity with pulp, for example, an anionic surfactant described in Japanese Patent No. 2721658 according to the previous application of the present applicant is used as a dispersant. The reverse phase suspension polymerization method used may be employed, or it may be synthesized using an aqueous solution polymerization method.

  In a conventional absorbent body mainly composed of pulp, when a superabsorbent polymer having low affinity with pulp is used in combination, the polymer is difficult to adhere to the pulp. Furthermore, since the shape stability of the absorbent body is inferior, the absorbent body is swayed during the wearer's activity, whereby the polymer tends to be unevenly distributed in the absorbent body. In order to prevent this phenomenon, the mixing ratio of the pulp must be increased with respect to the superabsorbent polymer. As a result, the amount of pulp used cannot be reduced, and the characteristics of the superabsorbent polymer can be fully utilized. There wasn't. In contrast, the present inventors surprisingly use an absorbent body mainly composed of a long-fiber web 20, so that even a highly absorbent polymer having a low affinity with pulp can be incorporated into the web. It was found that it can be uniformly supported. Of course, the absorbent body mainly composed of the long fiber web 20 can uniformly carry a polymer having high affinity with pulp.

The measure of affinity with pulp is measured by the following method. 1.0 g of the superabsorbent polymer is uniformly dispersed in a circle having a radius of 5 cm from the center on the filter paper (Advantech Toyo 4A 185 mm). Thereafter, in order to swell the superabsorbent polymer, 50 g of 0.9 wt% NaCl aqueous solution is uniformly applied in the circle, and after 1 minute from the completion, the polymer spray surface of the filter paper is directed downward. The affinity with the pulp is obtained by the following equation by measuring the amount A of the dropped polymer and the amount B of the polymer adhering to the filter paper without falling off.
Affinity with pulp = B / (A + B)

  Even when any of the above-described superabsorbent polymers is used, the superabsorbent polymer has a retention amount of 28 g / g or more, particularly 33 g / g or more, particularly 35 g / g or more under no load measured according to JIS K7223. It is preferable that it is more than g. Further, according to the same method, the holding amount under a load of 2 kPa is preferably 13 g / g or more, particularly preferably 15 g / g or more. The amount of retention is a measure of how much liquid the superabsorbent polymer can absorb and hold, and the higher this value, the more liquid can be absorbed and retained without re-releasing it. can do. When the amount of the superabsorbent polymer liquid used in the present invention is not less than the above value, the amount of liquid that can be absorbed before leakage occurs can be increased, and the amount of wetback can be reduced. There is an advantage that you can. Furthermore, the feel of the absorber after liquid absorption is improved. The reason why the two conditions of no load and 2 kPa load are set as the measurement conditions for the amount of liquid retained is when the body pressure is not applied to the absorbent article during urination (for example, when the wearer is standing) Or when the body pressure is applied (for example, when the wearer is sitting or lying on the floor). As described above, the load of 2 kPa substantially corresponds to the body pressure applied to the absorbent body while wearing the absorbent article.

  The method for measuring the amount of superabsorbent polymer retained is as shown in FIG. First, as shown in FIG. 2A, a cylinder 100 having a diameter of 60 mm is prepared. The cylinder 100 is separable into an upper part 100a and a lower part 100b. The upper part 100a and the lower part 100b can be integrated by screwing. A 400 mesh (mesh size 38 μm) wire mesh 101 is disposed between the upper portion 100a and the lower portion 100b, and the wire mesh 101 is fixed to the cylinder 100 by screwing the upper portion 100a and the lower portion 100b.

  Next, as shown in FIG. 2 (b), 1 g of the superabsorbent polymer P in a dry state before water absorption is spread on the wire net 101. A glass filter 102 is placed thereon, and a weight 103 is further placed thereon, so that a load of 2 kPa is applied to the superabsorbent polymer P. The total weight at this time is A (g).

  Next, as shown in FIG. 2 (c), the cylinder 100 is submerged in a container 104 containing physiological saline so that the superabsorbent polymer P absorbs the physiological saline. After leaving still for 30 minutes to sufficiently swell the superabsorbent polymer P, the cylinder 100 is pulled up from the container 104 as shown in FIG. Cut it. The total weight after draining is measured, and the value is defined as B (g).

  Separately from the above operation, the same operation as in FIGS. 2A to 2D was performed without spraying the superabsorbent polymer P, and the total weight was measured as shown in FIG. Is C (g).

  The retention amount (g / g) of the superabsorbent polymer P under a load of 2 kPa is calculated by (B-A-C) using the values of A, B, and C described above.

  On the other hand, the retention amount (g / g) of the superabsorbent polymer P under no load is the superabsorbent polymer under the load of 2 kPa except that the weight 103 is not used in the operations of FIGS. 2 (a) to (e). It is measured in the same manner as the measurement of the amount of P retained.

  In order to prepare the superabsorbent polymer having the above-mentioned retention amount, for example, a reversed phase using an anionic surfactant described in Japanese Patent No. 2721658 according to the above-mentioned previous application of the present applicant as a dispersant. A suspension polymerization method may be used.

  FIG. 1 shows a state in which the superabsorbent polymer 21 is embedded and supported almost uniformly in the web 20. However, the dispersion state of the superabsorbent polymer 21 is not limited to this. For example, the superabsorbent polymer 21 may be biased and carried on the skin 20 facing surface side of the web 20. Alternatively, the superabsorbent polymer 21 may be embedded and supported in the web 20 while being biased toward the non-facing surface side of the web 20. When the superabsorbent polymer 21 is biased toward the skin facing surface side or the skin non-facing surface side of the web 20, the abundance of the superabsorbent polymer 21 continuously changes in the thickness direction of the web 20. Or may be changed step by step. If the superabsorbent polymer 21 is biased toward the skin facing surface side of the web 20, the spot absorbability of the liquid is increased. The absorbent article provided with such an absorbent body 10 is suitable as an incontinence pad for light incontinence or a sanitary napkin. On the other hand, if the superabsorbent polymer 21 is biased toward the skin non-facing surface side of the web 20, the liquid diffusibility increases and the liquid absorbability of the entire absorbent body increases. The absorbent article provided with such an absorbent body 10 is suitable as a disposable diaper.

  FIG. 3 shows another example of the absorbent body 10 according to the absorbent article of the present invention. The absorbent body 10 of the present embodiment includes the same or different webs 20 and 20 and a spray layer of the superabsorbent polymer 21. The absorbent body 10 includes a plurality of webs 20, and a dispersed layer of the polymer 21 is located between the webs 20 and 20. There is no restriction | limiting in particular in the upper limit of the number of layers of a web, A suitable number of webs are used according to the specific use of an absorbent article. A part of the superabsorbent polymer 21 is supported in the web 20. The absorbent body 10 according to the present embodiment can be regarded as a superabsorbent polymer being biased at the center of the web 20 in the thickness direction.

  The dispersion state in the thickness direction of the superabsorbent polymer 21 in the absorbent body 10 is as described above, and examples of the dispersion state in the planar direction include the following. First, a typical sprayed state includes a state in which the superabsorbent polymer 21 is sprayed uniformly in the plane direction. As another spraying state, a state in which the superabsorbent polymer 21 is sprayed so as to be biased toward the front side of the absorbent body 10 is exemplified. In this case, the spreading basis weight in the width direction of the absorber 10 can be made the same, and the spreading basis weight can be increased toward the front side of the absorber 10. Alternatively, the superabsorbent polymer 21 can be sprayed so as to have a U-shape opened toward the rear side of the absorbent body 10. When the superabsorbent polymer 12 is dispersed so as to be biased toward the front side of the absorbent body 10, an absorbent article having a high effect of preventing liquid leakage from the front side of the body can be obtained. Such an absorbent article is particularly useful as a pants-type disposable diaper.

  Another spraying state of the superabsorbent polymer 21 in the planar direction of the absorbent body 10 includes a state in which the superabsorbent polymer 21 is sprinkled so as to be biased toward the rear side of the absorbent body 10. For example, the superabsorbent polymer 21 can be sprayed so as to have a U-shape opening toward the front side of the absorbent body 10. When the superabsorbent polymer 21 is dispersed so as to be biased to the rear side of the absorbent body 10, an absorbent article having a high effect of preventing liquid leakage from the rear side of the body can be obtained. Such an absorbent article is particularly useful as a disposable diaper for low-age infants and bedridden people.

  As another dispersion state of the superabsorbent polymer 21 in the planar direction of the absorbent body 10, the superabsorbent polymer 21 is not dispersed in the peripheral area of the absorbent body 10, and the superabsorbent polymer is surrounded in the central area surrounded by the peripheral area. The state which sprays is mentioned. Since the superabsorbent polymer 21 is not dispersed in the peripheral region of the absorbent body 10, it is possible to effectively prevent the superabsorbent polymer 21 from falling off the absorbent body 10.

  In the absorbent body 10, the long fibers constituting the web 20 are preferably oriented in one direction in the plane direction of the absorbent body 10. When the liquid is absorbed by the absorbent body 10 due to the orientation of the long fibers in one direction, the liquid diffuses preferentially in the orientation direction of the long fibers. That is, it diffuses preferentially in the planar direction of the absorber 10. Conversely, diffusion in the direction perpendicular to the orientation direction of the long fibers is suppressed. When long fibers are oriented in the longitudinal direction of the absorbent article, liquid leakage (lateral leakage) from the side of the absorbent article is effectively prevented. On the other hand, when the long fibers are oriented in the width direction of the absorbent article, diffusion in the longitudinal direction of the absorbent article is suppressed, and spot absorptivity is obtained.

As the long fibers constituting the web 20, it is preferable to use crimped ones. The long fiber preferably has a crimp ratio (JIS L0208) of 10 to 90%, particularly 10 to 60%, particularly 20 to 50%. By forming the web 20 from the crimped long fibers, it becomes easy to embed and carry the superabsorbent polymer 21 stably and in a large amount in the web 20. There is no particular limitation on the means for crimping the long fibers. Further, the crimp may be two-dimensional or three-dimensional. The crimp rate 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, and is calculated from the following equation: .
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 fiber diameter of the long fiber is related to the supportability of the superabsorbent polymer. On the condition that the basis weight of the web 20 is the same, satisfactory supportability can be obtained by using long fibers of 1.0 to 10 dtex, particularly 1.7 to 7.8 dtex. 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 of the web to be measured is less than 100 mm, preferably 50% or more, more preferably 70% or more, more preferably 80% or more of the fibers in the web extend over the entire length of the web. In this case, it is assumed that the fibers of the web are 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. The web in which the long fibers are oriented is a concept including a bundle of long fibers (so-called tow) as a raw material for forming the web and a tow layer of continuous filaments. In addition, fibers (cut fibers) in which part of the long fibers are cut and the fiber length is less than the above value may be mixed in the absorbent body. In many cases, the cut fibers are produced during the manufacturing process.

The absorbent body 10 of the present embodiment having the above structure is thin and has a low basis weight. Appropriate values are selected for the thickness and basis weight of the absorbent body 10 according to the specific application of the absorbent article. For example, when used as an absorbent body for disposable diapers for infants, the web 20 preferably has a basis weight of 5 to 200 g / m ² , particularly 10 to 100 g / m ² . In this case, on the other hand, the spreading basis weight of the superabsorbent polymer 21 is preferably 50 to 500 g / m ² , particularly preferably 100 to 300 g / m ² .

When used as an absorbent body of a sanitary napkin, the web 20 preferably has a basis weight of 5 to 100 g / m ² , particularly 10 to 50 g / m ² . On the other hand, the spreading basis weight of the superabsorbent polymer 21 is preferably 10 to ²⁰⁰ g / m ² , particularly preferably 15 to 100 g / m ² . When used as an absorbent body for an incontinence pad, the web 20 preferably has a basis weight of 5 to 200 g / m ² , particularly 10 to 100 g / m ² . On the other hand, the spreading basis weight of the superabsorbent polymer 21 is preferably 10 to 500 g / m ² , particularly preferably 15 to 350 g / m ² .

The total basis weight of the web 20 and the superabsorbent polymer 21 in the absorbent body 10 is preferably 120 to 400 g / m ² , particularly 150 to 300 g / m ² when the absorbent body 10 is used, for example, in a disposable diaper. . When used for a sanitary napkin, it is preferably 35 to 200 g / m ² , particularly 50 to 150 g / m ² . When used for an incontinence pad, it is preferably 35 to 500 g / m ² , particularly 50 to 400 g / m ² .

  The absorbent body 10 may be composed only of the web 20 containing the superabsorbent polymer 21, or the web 20 may be wrapped with, for example, various sheet materials. Moreover, various sheet materials may be arranged on the upper surface and / or the lower surface of the web 20, and the whole may be wrapped with another sheet material. Examples of the sheet material include paper such as fluff pulp and tissue paper, dry pulp sheets, and nonwoven fabrics (for example, air-through nonwoven fabric and airlaid nonwoven fabric). When the absorbent body 10 is used in a disposable diaper, the thickness of the absorbent body 10 is preferably as thin as 1 to 4 mm, more preferably 1.5 to 3 mm, regardless of the form of the absorbent body 10 described above. is there. When used for a sanitary napkin, the thickness is preferably 0.5 to 3 mm, more preferably 1 to 2 mm. When used as an incontinence pad, it is preferably 0.5 to 4 mm, more preferably 1 to 3 mm.

The thickness of the absorbent body 10 is measured under a state where an acrylic plate having a size of 5 cm × 5 cm is placed on the absorbent body 10 and a weight is further placed thereon, and a load of 2.5 g / cm ² is applied. In this embodiment, the thickness was measured using an LK080 class 2 laser displacement meter manufactured by Keyence Corporation. The number of measurement points was an average of 5 points, and when the measurement value fluctuated 20% or more, the data was deleted and another measurement value was added. A 250 g / cm ² load was previously applied to the sample for 12 hours to keep the wrinkles extended.

  FIG. 4 shows still another example of the absorbent body 10 according to the absorbent article of the present invention. The absorbent body 10 of the present embodiment has a structure in which a long fiber web 20 including a superabsorbent polymer 21 is stacked on a fluff pulp stacking fiber layer 22. In the fiber stack layer 22, a superabsorbent polymer 23 that is the same or different from the superabsorbent polymer 21 contained in the web 20 is contained. In FIG. 4, a state in which the polymer is included in the stacked fiber layer 22 is shown, but instead of this, the polymer may not be included in the stacked fiber layer 22. In the absorbent body 10, the fluff pulp stacking layer 22 acts as a primary stock layer of the excreted liquid, so even if the liquid excretion rate is high (for example, when urine is excreted), the liquid Leakage can be effectively prevented. From this viewpoint, it is preferable that the superabsorbent polymer 21 embedded and supported in the web 20 is biased and embedded on the skin 20 non-facing surface side of the web 20. Note that the superabsorbent polymer 23 may not be contained in the fluff pulp stacking layer 22. However, it is preferable to contain the superabsorbent polymer 23 because the effect of the stacked fiber layer 22 as the primary stock layer of the liquid is further enhanced. The absorbent article provided with the absorbent body 10 is suitable as a disposable diaper.

  As other examples of the absorbent body 10 according to the absorbent article of the present invention, those shown in FIGS. 5 to 7 can also be used. 5 (a) to 5 (c) shows an absorbent body 10 in a form in which one liquid-permeable sheet 30 and one or two layers of a long fiber web 20 containing a superabsorbent polymer 21 are combined. It is shown. Examples of the liquid permeable sheet 30 include a dry pulp sheet, a cotton sheet, a nonwoven fabric, a mixed sheet of fluff pulp and a superabsorbent polymer, and the like. In FIG. 5A, a liquid permeable sheet 30 is disposed below the web 20. In FIG. 5B, the liquid permeable sheet 30 is disposed on the upper side of the web 20. In FIG. 5B, the liquid permeable sheet 30 is disposed between the two layers of webs 20.

  6 (a) to 6 (c) show an absorbent body 10 in the form of a combination of two liquid-permeable sheets 30 and one or two layers of a long fiber web 20 containing a superabsorbent polymer 21. It is shown. The two liquid-permeable sheets 30 may be the same or different. In FIG. 6A, two sets of a combination of the liquid-permeable sheet 30 and the web 20 disposed thereon are stacked. In FIG. 6B, two sets of a combination of the web 20 and the liquid permeable sheet 30 disposed thereon are stacked. In FIG. 6C, the liquid permeable sheets 30 are respectively disposed above and below the web 20.

  FIG. 7 shows the absorbent body 10 in the form of a combination of three liquid-permeable sheets 30 and two layers of a long-fiber web 20 containing a superabsorbent polymer 21. The three liquid permeable sheets 30 may be the same type or different types. Similarly, the two layers of web 20 may be the same or different. The absorbent body 10 shown in FIG. 7 is configured by arranging a web 20 between liquid permeable sheets 30 adjacent to each other in the vertical direction.

  The preferable manufacturing method of the absorber which concerns on the absorbent article of this invention is as follows. For example, when manufacturing the absorbent body 10 having the form shown in FIG. 1, first, a long fiber tow having the above-described crimp rate is prepared. A web is obtained by opening the tow with a predetermined means while transporting the tow in a stretched state in the longitudinal direction. For the opening, for example, an air opening device using compressed air can be used. Since the long fibers have crimps, when the tension is applied, the long fibers are easily stretched in the longitudinal direction. A superabsorbent polymer is spread on the opened web. At the time of spreading, the web is transferred onto a vacuum conveyor while the transport speed of the opened web is reduced. The web is untensioned on the vacuum conveyor. Thereby, the stretched state of the web is released, and the long fibers return to the crimped state. Moreover, the thickness of the web becomes larger than that in the stretched state, and the embedded supportability of the superabsorbent polymer is improved. Under this condition, the superabsorbent polymer is sprayed. The long fibers in the crimped state have voids that can accommodate the superabsorbent polymer between the fibers. The superabsorbent polymer is buried and supported in the voids. Thereby, the superabsorbent polymer having a desired basis weight can be buried and supported. At the same time as the dispersion of the superabsorbent polymer, it is effective to promote suction of the polymer by carrying out suction from the surface of the web opposite to the surface where the polymer is dispersed. By appropriately adjusting the degree of suction, the polymer distribution in the thickness direction of the web can be changed.

  In the above-described embodiment, the web 20 contains only the superabsorbent polymer 21 having the above-described liquid flow rate or the superabsorbent polymer 21 having a scale of affinity with the pulp within the above range. However, instead of this, a superabsorbent polymer other than the superabsorbent polymer 21 may be blended for the purpose of imparting other functions to the absorbent article. However, if the superabsorbent polymer other than the superabsorbent polymer 21 is blended too much, the advantage of blending the superabsorbent polymer 21 having the above-described liquid passing speed is diminished. The blending amount of the superabsorbent polymer is preferably 60% by weight or less, particularly preferably 20% by weight or less, based on the total blending amount of the superabsorbent polymer.

  In another embodiment, the superabsorbent polymer mixed in the fluff pulp to be laminated with the superabsorbent polymer in the web may be the same as the superabsorbent polymer in the web, or different ones. It may be used. In the case of using different superabsorbent polymers, it is preferable to use superabsorbent polymers that ensure the performance of a liquid passing speed of 30 to 300 ml / min under a load of 2.0 kPa. When the level of liquid permeability differs between the superabsorbent polymers, the liquid permeability of the superabsorbent polymer in the layer located on the side close to the skin is located on the side far from the skin. Higher liquid permeability of the superabsorbent polymer in the layer is preferable in that the excrement can be absorbed quickly and the excrement can be fixed in the layer located on the side far from the skin. Further, it is preferable that the absorption capacity of the superabsorbent polymer in the layer located on the side far from the skin is higher. Preferably, the layer located on the side close to the skin is a web layer, and the layer located on the side far from the skin is a fluff pulp layer containing a superabsorbent polymer.

  The pants-type disposable diaper 1 as one embodiment of the absorbent article of the present invention is shown in FIGS. The diaper 1 includes an absorbent main body 5 having a liquid-permeable top sheet 2, a liquid-impermeable or water-repellent back sheet 3, and a liquid-retaining absorbent 10 positioned between both sheets 2 and 3, and the absorption And the exterior body 100 which is located on the outer side (non-skin contact surface side) of the adhesive main body 5 and is bonded and fixed to the absorbent main body 5. The diaper 1 has a crotch part C disposed in the crotch part of the wearer, and a ventral side part A and a back side part B extending in the front and rear thereof. The abdomen A is disposed on the wearer's abdomen when worn, and the back B is disposed on the wearer's dorsal side when worn.

  As shown in FIG. 10, the exterior body 100 includes two sheets 111 and 112 and elastic members of respective parts fixed between the two sheets. In the diaper 1, as shown in FIG. 9, a waist elastic member 71 that forms a waist gather at the periphery of the waist opening 7 between the two sheets 111 and 112, and a leg at the periphery of the leg opening 8. Leg elastic member 81 forming a gather, and waist gathers in a state of being divided into left and right waist parts D, which is a region from a position spaced 20 mm downward from the peripheral edge of the waist opening 7 to the upper end of the leg opening 8 Each of the waistline elastic members 91 is fixed in an extended state. Each elastic member 71, 81, 91 is joined by joining means such as a hot-melt adhesive.

  As shown in FIGS. 9 to 11, the absorbent body 10 in the diaper 1 of the present embodiment includes a first absorbent body 41 on the skin contact surface side of the absorbent body 10 and a first non-skin contact surface side of the absorbent body 10. 2 absorbers 42. The first absorbent body 41 is disposed on the skin contact surface side of the second absorbent body 42. The first absorbent body 41 in the present embodiment 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 5 and a width slightly narrower than the width of the absorbent main body 5. And as the 1st absorber 41, the web of the long fiber which has the hydrophilic property in which the superabsorbent polymer was contained is used, and the mixed fiber body of a pulp and a superabsorbent polymer is used as the 2nd absorber 42. It is used. The liquid passing speed under the 2.0 kPa load of the entire absorbent body 10 including the first absorbent body 41 and the second absorbent body 42 is 30 to 300 ml / min. Moreover, the weight ratio (superabsorbent polymer / long fiber) of the superabsorbent polymer and the long fiber in the first absorbent body 41 is 2 or more.

  The second absorbent body 42 has a substantially rectangular shape when viewed in plan, but has left and right portions of the crotch part C having missing portions 44 and 44 that facilitate the deformation of the absorbent body 10 into a three-dimensional shape. ing. The deformation of the absorbent body 10 into a three-dimensional shape includes (a) a deformation in the width direction in which the absorbent body 10 is deformed to form a concave shape in a cross section in the diaper width direction (for example, the cross section shown in FIG. 11) Typical examples are a longitudinal deformation in which 10 is deformed so as to form a concave shape in the longitudinal section of the diaper, and (c) a composite deformation in which these deformations in both directions are combined. As shown in FIGS. 9 and 11, the missing portion 44 in the present embodiment extends along the longitudinal direction of the absorbent body 10 at a portion of the crotch part C that is separated from the side edge 43 of the absorbent body 10. Is formed. Regarding the formation part of the missing part 44 formed in the crotch part C, being separated from the side edge part 43 of the absorbent body 10 is only required to be separated at least at the central position in the diaper longitudinal direction. The central position in the longitudinal direction of the diaper 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 II-II in FIG.

  The missing part 44 has a substantially arcuate and elongated shape defined by a straight part 45 and a circular arc part 46 connected to each end of the straight part 45. In each missing portion 44, the straight portion 45 is located closer to the side edge portion 43 of the absorber 10, and the arc portion 46 is located closer to the inner side in the width direction of the absorber 10. The missing part 44 does not extend to each end edge in the longitudinal direction of the second absorbent body 42, and is formed only at a substantially central part in the longitudinal direction of the second absorbent body 42. Therefore, a fiber stacking portion in which no missing portion exists is formed between each end portion of the missing portion 44 and the longitudinal front and rear edges of the second absorbent body 42.

  As shown in FIGS. 10 and 11, the first absorbent body 41 in the present embodiment is arranged so as to overlap the skin contact surface side of the second absorbent body 42, and the missing portion 44 of the second absorbent body 42, 44 is located below the first absorber 41. 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 10 in the present embodiment, the deformability of the absorbent body into a three-dimensional shape is improved because the second absorbent body 42 has the missing part 44. As shown in FIG. Both side portions, specifically, the side portion regions located on both sides of the central region in the width direction of the second absorbent body 42 easily stand up toward the wearer's skin when wearing the diaper.

  From the viewpoint of satisfactorily standing on both sides of the absorbent body 10 and forming an ideal three-dimensional shape that envelops the urine drainage section and from the viewpoint of preventing the absorbent body in the crotch section from acting in the widthwise central region of the absorbent body 10 In the diaper width direction, the distance W1 (see FIG. 9) between the side edge 43 of the absorbent body and the missing part 44 (the position of the missing part near the center of the diaper width direction) is the width W ( It is preferable that it is 10 to 40% of FIG. 9), and it is more preferable that it is 20 to 30%. The width W2 (see FIG. 9) between the left and right missing portions 44 is preferably 20 to 120 mm, particularly 40 to 100 mm. The width of the missing part 44 (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 44 in the longitudinal direction of the diaper is preferably 10 to 35 cm, particularly preferably 15 to 30 cm for an infant diaper, and 15 to 55 cm, particularly preferably 20 to 50 cm for an adult diaper.

  In addition, the absorber 10 in this embodiment has a vertically long rectangular plan view shape in the diaper front-rear direction as a whole. Further, the absorbent body 10 is fixed between the top sheet 2 and the back sheet 3 in a state where the absorbent body 10 is entirely covered with a water-permeable covering sheet (not shown) made of tissue paper or a water-permeable nonwoven fabric. Yes. Moreover, as for the surface sheet 2 in this embodiment, the part extended rather than the both-sides edge part of the absorber 10 is wound down by the non-skin contact surface of the absorber 10, and the non-skin contact surface of an absorber On the side, it is fixed to the back sheet 3 with an adhesive or the like (not shown). Each of the first absorbent body 41 and the second absorbent body 42 may be covered with a cover sheet. The first absorbent body 41 and the second absorbent body 42 may be partially bonded with an adhesive or the like, or may not be bonded.

  Leak-proof cuffs 6 are provided on both sides of the absorbent main body 5 in the longitudinal direction so as to extend in the diaper longitudinal direction. As shown in FIGS. 10 and 11, the leak-proof cuff 6 is formed by a leak-proof cuff forming sheet 60 and an elastic member 61 fixed to the leak-proof cuff forming sheet 60 in an expanded state.

  The leak-proof cuff forming sheet 60 is preferably arranged so as to cover both side edges 5c of the absorbent main body 5. Here, to cover both side edges of the absorbent main body 5, a leak-proof cuff having uprightness can be formed in the crotch, and the side edges of the absorbent main body are worn by the wearer due to the presence of the leak-proof cuff. It means that it is difficult to directly touch the skin. More specifically, the leak-proof cuff forming sheet 60 absorbs the diaper at the abdominal side A and the back side B (preferably further the crotch C) of the diaper 1 in the unfolded and extended state (see FIG. 9). It is preferable that the main body 5 is disposed so as to extend from the skin contact surface side 5a to the non-skin contact surface side 5b. Moreover, it is preferable that the leak-proof cuff forming sheet 60 is fixed to the skin contact surface side 5a of the absorbent main body 5 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 5 and the leak-proof property is improved. The skin contact surface side 5a is the surface side of the absorbent main body 5 that faces the wearer's skin when worn, and the non-skin contact surface side 5b of the absorbent main body 5 is absorbent. Of the both surfaces of the main body 5, the surface side is directed to the opposite side of the skin side of the wearer when worn.

  The leak-proof cuff 6 can stand at least at the crotch part C as shown in FIG. A plurality of elastic members 61 are fixed along the free end 62 in the vicinity of the free end 62 of the leak-proof cuff 6. The sheet 60 for leak-proof cuff formation is a surface on the skin contact surface side of the absorbent main body 5 in a folded state by being folded at two bent portions 64 and 65 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.) 63.

  In the present embodiment, a sheet-shaped water-repellent sheet having a predetermined width is folded as a leak-proof cuff forming sheet 60 in two along a fold line along the longitudinal direction, and a hot-melt adhesive is provided between opposing layers. Or the sheet | seat of the 2 layer structure joined by the partial heat | fever or an ultrasonic seal | sticker is used. The elastic member 61 is fixed in an expanded state between the layers of the two-layer structure sheet.

  As shown in FIG. 11, the absorbent main body 5 in the crotch C has a fixed end of the leak-proof cuff 6 at a position inside the diaper width direction with respect to both side edges 5 c in the longitudinal direction of the absorbent main body 5. And a fixing portion 67 to the leakproof cuff forming sheet 60. The fixing portion 67 is formed by connecting a leak-proof cuff forming sheet 60 and an extended portion of the surface sheet 2 that is wound down by known joining means such as heat sealing, high-frequency sealing, ultrasonic sealing, and hot-melt adhesive. It is formed by bonding.

  An elastic member 66 for raising the side of the absorbent main body is disposed in a stretched state on the outer side of the absorbent main body 5 in the diaper width direction from the fixed portion 67. The elastic members 66 are arranged on both side edges of the absorbent main body 5 so as to extend along the side edges and between the ventral side A and the back side B. The elastic member 66 in the present embodiment is disposed on both side edge portions of the absorbent main body 5, but the arrangement site is not particularly limited as long as it is outside the fixing portion 67, and the absorbent body 10 and the skin contact thereof. It can also distribute | arrange between the surface sheet 2 located in a contact surface side, between the absorber 10 and the back surface sheet 3, the inside of the coating sheet (not shown) of the absorber 10. It can also be placed in these two or more locations. However, it is preferable to arrange it at both side edges of the absorbent main body 5 or in the vicinity thereof. It is preferable that the fixing | fixed part 67 exists in the site | part which entered 5-50 mm from the both-sides edge part 5c of the absorptive main body 5, especially about 10-30 mm in the diaper width direction inner side.

  As shown in FIG. 11, in the width direction of the crotch part C, the position P1 of the fixed end of the leak-proof cuff 6 is substantially the same as the position of the missing part 44 (the position of the end part near the center of the diaper width direction of the missing part 44) P2. It is preferable that they match. The fixed end of the leak-proof cuff 6 is a place where the absorbent main body 5 and the leak-proof cuff forming sheet 60 are joined, which exists on the opposite side of the free end of the leak-proof cuff 6. When the positions P1 and P2 substantially coincide with each other, the rising properties of both sides of the absorbent main body 5 are further improved, and the absorbent main body 5 can more easily form an ideal three-dimensional shape that wraps around the urine drainage section. The 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. 11) is within 10 mm is also included. The distance W1 between the side edge portion 41 and the missing portion 44 of the absorbent body, the width W of the absorbent body, the width W2 between the left and right missing portions 44, the width of the missing portion, the width of the absorbent body 5 of the fixing portion 67. A preferable range of numerical values such as the distance from the side edges 5c and the distance between the positions P1 and P2 is measured at the center position in the diaper longitudinal direction.

  According to the diaper 1 of the present embodiment, in addition to the side portions of the absorbent body 10 being easily bent and standing, the presence of the elastic member 66 and the fixing portion between the absorbent main body 5 and the leak-proof cuff forming sheet 60 are provided. 11 is in a specific position or the like, as shown in FIG. 11, a concave pocket structure is formed between the both sides of the absorbent body 10 or between the both sides of the standing absorbent main body 5 toward the skin contact surface side. 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 6 which covers the side edge part of the absorptive main body 5 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. Further, the leak-proof cuff 6 makes it difficult for the side edge of the absorbent main body to directly contact the wearer's skin when worn, so that a sense of discomfort during wearing can be prevented.

  Further, the crotch part C is a part that is particularly susceptible to pressure from the left and right due to the movement of the wearer and the like, and therefore, the compression force applied from the left and right by the movement of the wearer in that part rises on both sides of the absorbent body 10. Therefore, the pad stability of the absorbent body 10 (such as a twist preventing effect) can be improved. Further, when the wearer opens the leg or twists the upper body, the missing part 44 opens, and the second absorbent body 42 is separated from the central area in the width direction and the side area. Since the missing portion 44 of the first absorbent body 41 overlaps with the first absorbent body 41, the first absorbent body 41 covers the gap formed between the central area and the side area of the second absorbent body 42, and excrement is caused from this gap. To prevent leakage.

  Further, according to the diaper 1 of the present embodiment, the side leakage prevention performance can be dramatically improved, so that the leakage prevention performance is improved or the decrease in the width of the absorbent main body and the crotch portion is suppressed. The width can be narrowed to improve fit. Such an effect is that the leak-proof cuff 6 in the crotch part C stands up greatly 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.

  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 10; 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 9 in FIGS. 10 and 11 denotes an adhesive that joins the absorbent main body 5 and the exterior body 10.

  Hereinafter, the present invention will be described in more detail with reference to examples. However, the scope of the present invention is not limited to such examples.

[Examples 1-4 and Comparative Examples 1-2]
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. At this time, the crimp rate of the web was 30%, and the number of crimps per cm of fiber was 15. As a result, the space between the long fibers was widened to facilitate the entry of the superabsorbent polymer, and the web was thickened to improve the embedding supportability of the superabsorbent polymer. A superabsorbent polymer was sprayed on the web, and the superabsorbent polymer was embedded and supported in the spread web to obtain a web containing the superabsorbent polymer. Under the web, a uniform mixed sheet of pulp and superabsorbent polymer was placed and combined. The superabsorbent polymer contained in the web is an acrylic acid polymer, and the physical properties and polymerization method are as shown in Table 1. Polymers A and F in Table 1 are commercially available products, and polymer BE was synthesized according to the reverse phase suspension polymerization method described in Japanese Patent No. 2721658. The basis weight of the web was 25 g / m ² , and the basis weight of the superabsorbent polymer in the web was 147 g / m ² . The uniformly mixed sheet of pulp and polymer was mixed and piled at an equal weight, and the basis weight was 300 g / m ² . The whole was wrapped with a tissue paper having a basis weight of 16 g / m ² and spray-coated with a hot melt adhesive, and pressed to obtain an absorbent. The basis weight of the entire absorbent body was 488 g / m ² and the thickness was 1.8 mm.

An air-through nonwoven fabric having a basis weight of 25 g / m ² was used as the surface sheet. It was composed of an air-through non-woven fabric, a core-sheath type composite fiber (having a thickness of 2.1 dtex, having a surface treated with a surfactant and having liquid permeability) made of polypropylene and a sheath made of linear low density polyethylene. A porous film having a basis weight of 20 g / m ² as a backsheet, used was composite by bonding a polypropylene spunbond nonwoven fabric having a basis weight of 20 g / m ² hot melt 1.5 g / m ^2. The porous film is obtained by uniformly forming 100 parts by weight of a linear low density polyethylene resin having a density of 0.925 g / cm ² and 150 parts by weight of calcium carbonate and 4 parts by weight of an ester compound as a third component. The film was uniaxially stretched twice in the longitudinal direction. Other than that, according to the manufacturing method of a normal disposable diaper, the disposable diaper shown in FIGS. 8-11 was obtained. The absorber was arranged so that the orientation direction of the web coincided with the longitudinal direction of the diaper. Table 2 shows the physical properties of the absorbers obtained in the examples and comparative examples.

  About the disposable diaper obtained by the Example and the comparative example, the liquid absorption time when a liquid was repeatedly absorbed under load was measured with the following method. The results are shown in Table 3.

(Measurement of liquid absorption time)
The diaper was placed on a model that can repeatedly urinate pseudo urine at a predetermined speed and amount, and imitates the baby's body shape and weight, so that the body is lying on its back. In this posture, the body pressure applied to the absorber near the stomach becomes approximately 2.0 kPa. The urination was performed in this state, and the time until the pseudo urine disappeared from the top sheet was measured as the liquid absorption time. It means that the longer the liquid absorption time, the longer the simulated urine remains between the model and the surface sheet. The model can adjust the baby's body shape, weight, posture, simulated urine speed, volume, and urination interval arbitrarily.

  As is apparent from the results shown in Table 3, the diaper of the example has a longer liquid absorption time when the liquid is repeatedly absorbed under load, even if the number of times of liquid absorption is increased, as compared to the diaper of the comparative example. I find it difficult.

It is a mimetic diagram showing the section structure of an example of the absorber concerning the absorptive article of the present invention. It is a figure which shows the measuring method of the retention amount of the liquid of a superabsorbent polymer. It is a schematic diagram which shows the cross-section of the other example of the absorber which concerns on the absorbent article of this invention. It is a schematic diagram which shows the cross-section of the further another example of the absorber which concerns on the absorbent article of this invention. It is a schematic diagram which shows the cross-section of the further another example of the absorber which concerns on the absorbent article of this invention. It is a schematic diagram which shows the cross-section of the further another example of the absorber which concerns on the absorbent article of this invention. It is a schematic diagram which shows the cross-section of the further another example of the absorber which concerns on the absorbent article of this invention. It is a perspective view which shows the underpants type diaper as one Embodiment of the absorbent article of this invention. FIG. 9 is a plan view showing a state in which the diaper shown in FIG. 8 is separated and developed by a side seal portion and the elastic member of each portion is expanded and expanded in a flat shape (expanded and extended state), partially broken. It is sectional drawing which shows typically the II cross section of FIG. It is sectional drawing which shows typically the II-II line cross section of FIG. 9 in a diaper use state.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Absorber 20 Long fiber web 21 Superabsorbent polymer 22 Pulp fiber layer 23 Superabsorbent polymer 30 Liquid permeable sheet

Claims (6)

An absorbent body having a first absorbent body on the skin contact surface side and a second absorbent body on the non-skin contact surface side;
A hydrophilic long fiber web containing a superabsorbent polymer is used as the first absorbent, and a mixed product of pulp and superabsorbent polymer is used as the second absorbent,
The second absorbent body has left and right crotch parts with missing portions that facilitate deformation of the absorbent body into a three-dimensional shape,
The missing part is formed at a portion spaced from the side edge of the absorber in the crotch portion so as to extend along the longitudinal direction of the absorber,
Superabsorbent polymer contained in the first absorbent body, following affinity measure of the measured pulp way 0.3-0.9 der is, and was measured by the following method 2.0kPa The liquid flow rate under load is 30 to 300 ml / min,
An absorbent article, wherein the hydrophilic long fiber web comprises acetate long fiber tows .
[Measure of affinity with pulp]
1.0 g of the superabsorbent polymer is uniformly dispersed in a circle having a radius of 5 cm from the center on the filter paper (Advantech Toyo 4A 185 mm). Thereafter, in order to swell the superabsorbent polymer, 50 g of 0.9 wt% NaCl aqueous solution is uniformly applied in the circle, and after 1 minute from the completion, the polymer spray surface of the filter paper is directed downward. The affinity with the pulp is obtained by the following equation by measuring the amount A of the dropped polymer and the amount B of the polymer adhering to the filter paper without falling off.
Affinity with pulp = B / (A + B)
[Liquid flow rate under 2.0 kPa load]
The cock is placed in a filtering cylindrical tube having a metal mesh (mesh size: 150 μm) and a narrow tube (inner diameter: 4 mm, length: 8 cm) at the lower end of a vertically standing cylinder (inner diameter: 25.4 mm). In a closed state, 0.32 g of a measurement sample adjusted to a particle size of 850 to 150 μm is added, 50 ml of physiological saline is poured, and after standing for 30 minutes, a load with a wire mesh (aperture 150 μm, diameter 25 mm) is applied. (21.2 g) was inserted into the filter cylinder so that the wire mesh and the measurement sample were in contact, and after 1 minute, the weight (77.0 g) was placed on the load with the wire mesh, and left still for 1 minute. Open and measure the time (T1) (seconds) until the liquid surface of 0.9% by weight physiological saline reaches the 20 ml scale line from the 40 ml scale line. Without Which is the time}.
Flow rate (ml / min) = 20 × 60 / (T1-T0)   The absorbent article according to claim 1, wherein the long fibers have crimps and are oriented in a planar direction of the absorbent body.   The superabsorbent polymer is uniformly embedded and supported in the web, or is embedded and supported in a biased manner on the skin facing surface side or the skin non-facing surface side of the web in the web. Or the absorbent article of 2. The absorbent article according to any one of claims 1 to 3 , wherein a retention amount of the superabsorbent polymer measured in accordance with JIS K7223 is 28 g / g or more, and a retention amount under a load of 2 kPa is 13 g / g or more. A liquid-permeable top sheet, a liquid-impermeable or water-repellent back sheet, and an absorbent main body having the absorbent body positioned between both sheets, and the non-skin contact surface side of the absorbent main body Comprising an outer body that is bonded and fixed to the absorbent main body,
Leak-proof cuffs are provided on both sides in the longitudinal direction of the absorbent main body so as to extend in the longitudinal direction of the absorbent article,
The leak-proof cuff has a free end and a fixed end existing on the opposite side, and the leak-proof cuff is joined to the non-skin contact surface of the absorbent main body at the position of the fixed end,
The absorbent article according to claim 1, wherein the position of the fixed end of the leak-proof cuff substantially coincides with the position of the missing portion.   The absorbent article according to claim 1, wherein the superabsorbent polymer is obtained by a reverse phase suspension polymerization method using an anionic surfactant as a dispersant.

Images