JP2006198396A - Elastic absorber - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an absorber of a highly elastic absorbent article. <P>SOLUTION: The absorber 1 comprises a hydrophilic web 2 with long fiber, in which highly absorbent polymers 3 are buried and supported, covered with a liquid-permeable sheet 4. The hydrophilic long fiber has a crimp percentage of 10-60%, and the web 2 of the long fiber is highly oriented in the planar direction of the absorber 1. The liquid-permeable sheet 4 is processed so that the sheet 4 can be extended, and the whole absorber can be extended/contacted in the direction of orientation of the web 2. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a stretchable absorbent body used for various absorbent articles such as disposable diapers and sanitary napkins.

  Absorbent bodies for absorbent articles using long fiber spread tows are known. For example, an absorbent body comprising a crimped acetate fiber web 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 absorbent body, is known. (See Patent Document 1).

  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.

  As an absorption layer having long fiber tows, one in which the tows extend 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.

  However, since none of the above-mentioned absorbers have elasticity, when an absorbent article such as a disposable diaper incorporating the absorber is worn, the absorber sufficiently follows the movement of the wearer's body. It cannot be done, and the absorbent body is kinked and the fit is liable to deteriorate.

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

  Accordingly, an object of the present invention is to provide an absorbent body for absorbent articles that can eliminate the various disadvantages of the prior art described above.

The present invention is an absorber formed by wrapping a hydrophilic web having a long fiber embedded with a superabsorbent polymer with a liquid-permeable sheet,
The hydrophilic long fibers have a crimp rate of 10 to 60%, and the web of the long fibers is highly oriented in the plane direction of the absorber,
The above object is achieved by providing a stretchable absorbent body in which the liquid-permeable sheet can be stretched and the absorbent body can stretch and contract in the web orientation direction as a whole.

  Moreover, this invention provides the absorbent article provided with the said absorber.

  Since the absorbent body of the present invention has stretchability, the absorbent article provided with the absorbent body has high fit with the wearer's body. Therefore, when the absorbent article provided with the absorbent body of the present invention is worn, the absorbent article sufficiently follows the movement of the wearer's body. Furthermore, since the absorber can be deformed even if it receives the movement of the wearer, the absorber is less likely to be swayed. As a result, it becomes difficult to generate a gap between the absorbent article and the wearer's body, and leakage is effectively prevented. In addition, since the absorbent body of the present invention has a web, it is softer and thinner than an absorbent body mainly composed of fluff pulp having a comparable absorption capacity. Therefore, the absorbent article provided with the absorbent body is easy to wear, and it is difficult for a feeling of strangeness to occur during wearing.

  The present invention will be described below based on preferred embodiments with reference to the drawings. FIG. 1 is a perspective view of an embodiment of the absorbent body of the present invention. The absorbent body 1 of the embodiment shown in FIG. 1 is suitably used as an absorbent body for various absorbent articles such as disposable diapers and sanitary napkins, and has a substantially vertically long flat shape. . The absorbent body 1 is configured by a hydrophilic web 2 having long fibers wrapped with a liquid-permeable sheet 4. A superabsorbent polymer 3 is embedded and supported on the web 2. The hydrophilic web 2 having long fibers is highly oriented in the longitudinal direction of the absorbent body. The absorber 1 has elasticity in the orientation direction of the hydrophilic web 2 having long fibers.

  Long fibers are 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. Moreover, although the long fiber itself does not have hydrophilicity, what has hydrophilicity as the whole web is also included. The long fiber itself does not have hydrophilicity. However, the hydrophilic property of the entire web is, for example, a web made of hydrophilic material integrated with a web made of non-hydrophilic long fibers. Is mentioned. Preferred long fibers are inherently hydrophilic long fibers, and long fibers such as nylon, acrylic, acetate and rayon are particularly preferred. In particular, acetate, which is a fiber having a moisture content of less than 10%, is particularly preferable because it retains its bulkiness even when wet. Here, the moisture content is a value measured in an environment of 25 ° C. and a relative humidity of 65%.

  In the present specification, the hydrophilic web refers to a web having a water absorption height measured in the orientation direction of preferably 20 mm or more, more preferably 30 mm or more. The Klem water absorption height is measured according to JIS P8141. The value 30 seconds after the start of water absorption is read, and the average value of 3 samples is taken as the measured value. Depending on the sample, the water absorption height varies in the width direction. In that case, the value obtained by averaging (visually) the width direction is taken as the measurement value.

  There is no restriction | limiting in particular in the fiber diameter of a long fiber. In general, satisfactory results are obtained by using long fibers of 1.0 to 7.8 dtex, in particular 1.3 to 7.0 dtex, and further 1.7 to 5.6 dtex. In the present specification, 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 density of the web 2 is 0.005 to 0.20 g / cm ³ , particularly 0.01 to 0.10 g / cm ³ , and the absorbent 1 is kept flexible in that the liquid permeability is good. This is preferable from the point of quickly absorbing the liquid.

As the long fiber, a crimped one is used. Crimping refers to “crimping of fibers” in JIS L0208. The long fiber has a crimp rate (JIS L 0208) of 10 to 60%, preferably 20 to 60%, and more preferably 20 to 50%. By forming the web 2 from the crimped long fibers, sufficient stretchability can be imparted to the absorbent body 1. 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 the length (A) when the long fiber is stretched straight and without stretching the fiber itself, and the length of the straight line (B) between the start point and end point of the fiber in the natural state. ) Is defined as a percentage of the length when stretched, and is calculated from the following equation.
Crimp rate = (A−B) / A × 100 (%)
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.

  As described above, in the present embodiment, stretchability is imparted to the absorbent body 1 by utilizing the stretchability of the crimped long fiber web. Furthermore, there is also an advantage that the absorbent body 1 can be made flexible by using a long-fiber web as a constituent material of the absorbent body 1. Details are as follows. As a liquid-absorbing material for absorbent articles, pulverized pulp is generally used. Since pulverized pulp is a stiff material, diapers using pulverized pulp tend to have poor stretch response. In addition, it tends to be difficult to fit the wearer's body. On the other hand, since the long fiber web is a flexible material, the absorbent body 1 can be made flexible by using it as the absorbent body 1 of the absorbent article. Can be good. Moreover, it becomes easy to fit the absorber 1 to a wearer's body.

  In the pulverized pulp generally used as the liquid absorbing material of the absorbent article, the integral structure as the absorbent body is easily broken by the liquid absorption. On the other hand, even if a long fiber web absorbs liquid, the integral structure as an absorber is not easily broken. Also from this point of view, it is advantageous to use a long fiber web as the absorbent body 1.

  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, particularly 8 to 18 per cm.

  In the absorbent body 1, the hydrophilic web 2 having long fibers is highly oriented in one direction. Therefore, the liquid absorbed by the absorber 1 is likely to diffuse in the orientation direction of the web 2. Utilizing this fact, for example, if the absorbent body 1 is arranged on the absorbent article so that the orientation direction of the hydrophilic web 2 having long fibers coincides with the longitudinal direction of the absorbent article, the width direction of the absorbent article It is possible to effectively prevent liquid leakage from the liquid (so-called side leakage).

  The orientation of the long fiber is not limited as long as the vector connecting the start point and end point of the long fiber is oriented in the plane direction, and part of the long fiber is caused by twisting or entanglement between the start point and the end point. Includes the ones in which the long fibers are oriented in the plane direction as a whole, even if is oriented in the vertical direction (the thickness direction of the absorber). In the present specification, highly oriented means that the degree of orientation is preferably 1.2 or more, more preferably 1.4 or more, with respect to the orientation of the fiber. The degree of orientation is measured using a Microwave molecular orientation analyzer MOA-2001A manufactured by KANZAKI. The sample size is 100 mm in the longitudinal direction and the width is 50 mm, and the average value of three points is the degree of orientation (if the sample size is less than this size, a plurality of samples are arranged so as not to overlap each other). .

  As the superabsorbent polymer 3 embedded and supported on the hydrophilic web 2 having long fibers, a particulate material is generally used. However, it may be fibrous. When using a particulate superabsorbent polymer, if the shape is an indeterminate type, a block type, or a bowl type, it should be embedded and supported by the basis weight of the same amount to 20 times the web 2. Can do. Further, in the case of a spherical particle aggregation type or a spherical type, it can be embedded and supported with a basis weight of the same amount or more and five times or less with respect to the web 2. For these particle shapes, it is desirable to select the former when it is particularly desired to achieve both high absorption and thinning, and the latter when importance is placed on the texture (reduction of the feeling of shaving of the superabsorbent polymer). The buried support refers to a state in which the superabsorbent polymer enters the space formed by the long fibers forming the web, and the polymer is not easily moved or dropped even by the violent movement of the wearer. . In the state of being buried and supported, the superabsorbent polymer is attached to the long fibers by being entangled or caught. Or it adheres to the long fiber by the adhesiveness of the superabsorbent polymer itself. The space formed by the long fibers is easily deformed when subjected to stress from the outside. However, since the stress can be absorbed by the entire long fiber, the space is prevented from being destroyed. A part of the superabsorbent polymer is embedded and supported in the web, or almost all of the superabsorbent polymer is uniformly embedded and supported in the web depending on the manufacturing conditions of the absorber.

  “Uniform” means the variation in the amount of the superabsorbent polymer in the thickness direction or width direction of the web when the superabsorbent polymer is completely uniformly arranged and when a part of the web is taken out. Means a case where the basis weight has a distribution within 2 times. Such variation is caused by the fact that, in the production of the absorbent body, a superabsorbent polymer is rarely supplied excessively, and a part with an extremely high application amount is partially generated. In other words, the above “uniform” includes cases where inevitably variations occur, and does not include cases where the superabsorbent polymer is distributed so as to intentionally vary.

  As described above, since the long fiber has crimps, it has a large number of spaces capable of holding particles. The superabsorbent polymer 3 is held in the space. As a result, even if a large amount of the superabsorbent polymer 3 is sprayed, the extreme movement and dropout are less likely to occur. Moreover, even if a wearer performs intense operation | movement, the structure of the absorber 1 becomes difficult to be destroyed. Depending on the superabsorbent polymer used, the crimp rate and the amount of long fibers used are adjusted as appropriate. If the web is composed only of long fibers that do not have crimps or have a small degree of crimp, and this is used as an absorbent body, when a large amount of superabsorbent polymer is used, its extreme movement and dropout may occur. It is easy to happen. On the other hand, if long fibers with a too high crimp rate are used, it is not easy to allow the superabsorbent polymer to enter between the long fibers. It is easy to happen.

  Since the superabsorbent polymer is stably held in the space formed by the crimped long fibers, the absorbent body 1 according to this embodiment can hold a large amount of the superabsorbent polymer. Even in the conventional absorbent body, if the amount of the fiber material is increased, a large amount of the superabsorbent polymer can be retained, but in this case, the basis weight and thickness of the absorbent body are increased. On the other hand, in the present invention, the amount of the superabsorbent polymer is relatively large with respect to the amount of the fiber material. Specifically, the basis weight of the superabsorbent polymer is preferably not less than the basis weight of the web, more preferably not less than 2 times, more preferably not less than 3 times when viewed from the whole absorbent body. As a result, the absorber 1 is made thinner and has a lower basis weight. As a result, the stretch response of the absorbent body 1 is good. The upper limit of the ratio of the basis weight of the superabsorbent polymer to the basis weight of the web is determined from the viewpoint of extreme movement of the superabsorbent polymer and prevention of falling off. Depending on the degree of crimp of the long fibers, the upper limit is 20 times or less, preferably 15 times or less, and more preferably 10 times or less. Extreme movement and dropout are unlikely to occur.

  The supportability of the superabsorbent polymer on the long fiber web is related to the network structure formed by the web and the physical properties of the superabsorbent polymer. From the viewpoint of the network structure, in the present invention, the network is controlled by controlling the stereoregularity of the web, that is, the crimp ratio, fineness, density, etc. of the web, so that the supportability of the polymer is expressed. . In the present invention, since the constituent fibers of the web are not bonded to each other, the size of the mesh formed on the web can be changed to such an extent that the superabsorbent polymer can be retained. Since the size of the mesh in the web can be changed, the supportability of the polymer becomes higher than in the case where the superabsorbent polymer is supported on a fiber assembly having a bonding point such as a nonwoven fabric. The size of the mesh can be determined by, for example, (a) applying a superabsorbent polymer in a state where a fiber is tensioned and then releasing the tension, or (b) controlling the web tension in advance. It can be controlled by spraying a superabsorbent polymer under a state in which a shrinkage ratio is expressed and further applying tension or pressure to the web.

  On the other hand, the physical properties of the polymer related to the polymer supportability include shape, particle size distribution, particle size, bulk density, surface properties, internal friction coefficient, fluidity, dispersibility, moisture content, chargeability, adhesion, and aggregation. There is sex. Among these, the particle size distribution and particle size of the polymer are closely related to the above-described web network structure. The carrying ability of the superabsorbent polymer is also affected by the number of collisions between the polymer and the long fibers inside the absorbent body when an external force or vibration is transmitted to the absorbent body due to the movement of the wearer. The higher the number of collisions, the more the high-absorbent polymer is screened by the mesh created by the long fibers, resulting in lower supportability. The number of collisions is affected by the fluidity of the polymer. The number of collisions increases with higher fluidity polymers. In addition, the polymer having high fluidity and once escaped from the restraint of the web easily moves and becomes difficult to be supported on the web.

  As for the fluidity of the polymer, when comparing the bulk type polymer and the spherical particle aggregation type polymer, the spherical particle aggregation type polymer has higher fluidity than the bulk type polymer. As a result, the bulk type polymer has higher supportability than the spherical particle aggregation type polymer. Further, since the spherical particle aggregation type polymer has a smooth surface, the degree of friction with the fiber and the catching on the fiber is lower than that of the bulk type polymer. Also from this viewpoint, the bulk type polymer has higher supportability than the spherical particle aggregation type polymer.

  The superabsorbent polymer can be supported in the web more efficiently by carrying out various post-processing after the superabsorbent polymer is supported on the crimped long fiber web. Examples of the means include (1) wrapping the entire web with a sheet material such as paper or nonwoven fabric, or overlapping the sheet material, and (2) fluff pulp containing or not containing a superabsorbent polymer. And (3) constraining the web structure with bonding means using hot melt adhesive, heat, and ultrasonic waves.

As an evaluation of the extent to which the superabsorbent polymer is buried and supported, a loading rate measured by the following method can be employed. First, using a long fiber, a web having a uniform thickness of 200 mm in the longitudinal direction and 100 mm in the width direction is produced. At this time, the amount of long fibers is adjusted so that the basis weight of the web is 26 g / m ² . Thereafter, the web is stretched in the fiber orientation direction to adjust the crimp rate. By this operation, the basis weight of the web changes from the initial basis weight of 26 g / m ^2, so the weight of the web is measured and the exact basis weight is calculated. The polymer is sprayed with the crimp ratio adjusted, and 100 × 200 mm is cut off. The polymer is dispersed by hand in a state where the web is laid sideways, and the superabsorbent polymer is uniformly dispersed by hand so that the basis weight of the polymer becomes 10 times the basis weight of the web. When the dispersion of the polymer is completed, the entire web is wrapped with a tissue having a basis weight of 16 g / m ² , compressed with a rubber roll, and then the elongation of the long fibers is released. The tissue and the web are bonded with an adhesive.
Next, a 100 mm × 100 mm measurement sample is cut out from the center of the web. When the tissue on the cut surface is pressure-bonded by cutting and the cut surface is blocked, the pressure-bonded state of the tissue on the cut surface is released. The cut measurement sample is suspended so that the long fibers are oriented in the vertical direction. Under this condition, the measurement sample is reciprocally oscillated in the horizontal direction at an amplitude of 5 cm and a speed of once per second. The weight of the polymer dropped by this reciprocating vibration is measured, and the value is defined as S1.
Then, using the value of S1 and the value of the superabsorbent polymer weight S0 (that is, 10 times the web weight) contained in the measurement sample before reciprocating vibration, the loading rate is calculated from the following equation.
Loading rate (%) = {1- (S1 / S0)} × 100
When the value of the loading rate measured in this way is 60% or more, particularly 70% or more, and particularly 80% or more, it can be said that the superabsorbent polymer is hardly detached.

As an evaluation of the degree to which the superabsorbent polymer is buried and supported, a migration rate measured by the following method can be employed in addition to the above-described loading rate. First, an initial weight W0 of a measurement sample of 100 mm × 100 mm used for the measurement of the carrying rate is measured in advance. The measurement sample after the measurement of the loading rate is cut in a direction perpendicular to the direction in which the long fibers extend, and is divided into two equal parts. The weight of each of the two halves divided into two is measured, and the weight of the halved fragment having the larger variation from 1/2 of the initial weight W0 of the measurement sample is adopted as the weight W1 for calculating the transfer rate. To do. For example, assuming that the weights of two fractional pieces are W1 ′ and W1 ″, if these W1 ′ and W1 ″ satisfy the following expression, W1 = W1 ′.
| W1'-W0 / 2 |> | W1 "-W0 / 2 |
Using the value of W1 determined in this way and the value of the initial weight W0 of the measurement sample, the movement rate is calculated from the following equation.
Movement rate (%) = {1-W1 / (W0 / 2)} × 100
When the value of the migration rate thus measured is 40% or less, particularly 30% or less, particularly 20% or less, it can be said that the migration of the superabsorbent polymer is difficult to occur.

  The following evaluation method can also be performed on the measurement sample in which the loading rate is measured. 50 g of physiological saline (0.9% by weight NaCl) is evenly sprayed on the measurement sample for which the loading rate was measured, and the way the measurement sample swells is visually observed. When the variation in the thickness of the measurement sample is within 2 times, it can be said that the superabsorbent polymer is hardly moved or dropped off.

  When the superabsorbent polymer is not sufficiently embedded in the web, hot-melt adhesives, various binders (such as acrylic emulsion adhesives), sugar derivatives such as carboxymethylcellulose and ethylcellulose, thermoplastic resins such as polyethylene, etc. Can be appropriately added to the web. Furthermore, you may use together the sheet | seat etc. which gave uneven | corrugated processing or flocking.

  In order to embed and carry a superabsorbent polymer on a web made of crimped long fibers, for example, the following method can be used. First, a long fiber web having the above-described crimp rate is prepared. The web is opened by a predetermined means. For the opening, for example, an air opening device using compressed air can be used. Next, the opened web is stretched to a predetermined length. In this case, it is not necessary to stretch the long fiber completely, and it is sufficient to stretch the superabsorbent polymer so as to be stably embedded and held in the web.

Various adhesives such as hot melt pressure-sensitive adhesive are applied to the web with the long fibers stretched. The coating pattern should just be a method which does not inhibit the expansion-contraction of the absorber 1. FIG. For example, it is preferable to adhere in a linear or dot pattern. Specifically, coating such as spiral spray method, slot spray method, control shim method (hot melt draws Ω-shaped curve), bead method and the like can be mentioned. In addition, if a coater method is used, striped coating and the like can be mentioned. In particular, it is preferable to use a spray coating capable of successfully performing dotted adhesion. The adhesive is preferably applied in such a low amount that the liquid does not pass through the web. Specifically preferred are coating weight from 1 to 20 g / m ^2, more preferably 2 to 10 g / m ^2, and more preferably from 3 to 7 g / m ^2.

  Further, the entire web may be applied uniformly, or a non-adhesive region may be partially provided. A non-adhesion area | region will have high elasticity with respect to an adhesion | attachment area | region, and the area | region from which an elasticity differs in an absorber can be formed.

  Furthermore, in the case of constituting an absorbent article using the absorbent body of the present invention, the absorbent body and other members (for example, a surface sheet, a leak-proof sheet, a sheet combined with an elastic body, a stretchable sheet, etc.) Need to be compounded. Since other members do not necessarily exhibit the same stretchability as the absorbent body, it is preferable to partially bond the entire absorbent body rather than the entire absorbent body when combined with other members. Examples of the method of compounding with other members include adhesion using heat and ultrasonic waves in addition to adhesion using hot melt.

  After the application of the adhesive is completed, the superabsorbent polymer is spread in layers on the web. Release the stretched state of the long fiber after spraying is completed. As a result, the stretched long fibers contract. As a result, the superabsorbent polymer is retained in the space formed by the shrinkage of the long fibers. In this way, the superabsorbent polymer is buried and supported in the web. If necessary, a web prepared separately may be overlaid thereon. As a result, the two webs are bonded in the form of dots.

  The web 2 in which the superabsorbent polymer 3 is embedded and supported is wrapped with a liquid-permeable sheet 4. As the liquid permeable sheet 4, for example, a fiber material sheet, a perforated film, or the like can be used. From the viewpoint of good liquid permeation, the liquid permeable sheet 4 is preferably made of a hydrophilic fiber sheet. As the hydrophilic fiber sheet, paper such as tissue paper and various non-woven fabrics can be used. Examples of the non-woven fabric include non-woven fabrics made of hydrophilic fibers such as cotton and rayon, and non-woven fabrics made by subjecting synthetic resin fibers to a hydrophilic treatment. Specific examples include a spunbond nonwoven fabric, a spunlace nonwoven fabric, an airlaid nonwoven fabric, and an air-through nonwoven fabric. Moreover, the nonwoven fabric which consists of various elastomer resins, such as polyolefin resin, polyester resin, and polyurethane resin, may be sufficient.

The basis weight of the liquid permeable sheet 4 is one of the factors that affect the liquid permeability of the sheet 4 and the flexibility and fit of the absorbent body 1. From this viewpoint, the basis weight of the liquid permeable sheet 4 is preferably 5 to 250 g / m ² , particularly preferably 10 to 40 g / m ² .

  The web 2 in which the superabsorbent polymer 3 is embedded and supported and the liquid permeable sheet 4 are, for example, the web 2 in which the stretched state of the long fibers is released after the superabsorbent polymer spraying is completed, with a hot melt adhesive or the like. The coated liquid-permeable sheet 4 can be joined and combined. Further, the web 2 can be combined by being joined to the liquid-permeable sheet 4 with a hot-melt adhesive or the like in the stretched state. In the absorbent body 1 thus obtained, the web 2 contracts in the orientation direction due to the contraction force of the crimped hydrophilic long fibers. As the shrinkage occurs, the liquid-permeable sheet also shrinks. Therefore, the absorbent body 1 having such a configuration can be extended in the orientation direction of the web 2 without subjecting the liquid-permeable sheet itself to stretching. The absorbent body 1 having such a configuration can be expanded and contracted in the range of expansion and contraction of the web 2, and the surface of the absorbent body 1 becomes uneven as the web contracts. As a result, since the surface area of the absorber 1 can be improved, there is an advantage that the liquid absorption rate can be improved and the diffusion in the vertical direction can be suppressed. Further, since the liquid permeable sheet 4 is not perforated, there is an advantage that the possibility that the superabsorbent polymer is exposed from the absorber 1 is small.

  Further, as shown in FIG. 1, the liquid permeable sheet 4 may be processed so that the sheet 4 can be extended. As a result, the absorbent body 1 as a whole is configured such that the stretchable range in the orientation direction of the web 2 is expanded. Specifically, since the web 2 in the absorbent body 1 has crimped hydrophilic long fibers, it inherently has stretchability regardless of its orientation direction. In addition to this, if the liquid-permeable sheet 4 can be extended, the absorbent body 1 can be extended as a whole. On the other hand, when the stretched state of the absorbent body 1 in the stretched state is released, the web 2 contracts in the orientation direction due to the shrinkage force caused by the crimped hydrophilic long fibers. With this contraction, the liquid permeable sheet 4 also contracts. By such a mechanism, the absorber 1 as a whole can be expanded and contracted in the orientation direction of the web 2. The absorbent body 1 having such a configuration is thinner and has elasticity, and since the surface of the absorbent body 1 is flat, there is an advantage that the liquid can be diffused smoothly. In addition, since the liquid permeable sheet 4 is not perforated, there is an advantage that it absorbs highly viscous liquid under elongation, and the occlusion of the absorbed liquid increases after contraction. The processing method for obtaining the absorbent body 1 having the configuration shown in FIG. 1 may be determined by a specific design policy of the absorbent article.

  The direction of expansion and contraction of the absorbent body 1 does not depend on the orientation direction of the hydrophilic web 2 having long fibers. This is because the long fibers have crimps, and the web 2 can be stretched in the orientation direction, the direction orthogonal to the orientation direction, and any other direction. This is the same whether the long fibers are bonded or not. The direction of expansion and contraction of the absorbent body 1 depends on the direction in which the liquid-permeable sheet 4 that wraps the web 2 can be extended. That is, if the liquid-permeable sheet 4 can be extended only in a certain direction, the absorber 1 can be expanded and contracted only in that direction. When a nonwoven fabric or a woven fabric is used as the liquid permeable sheet 4, the nonwoven fabric or the woven fabric has extensibility in the direction orthogonal to the fiber orientation direction. It is not limited to the orientation direction. However, the maximum elongation (easiness of elongation) of the absorbent body 1 can have anisotropy. That is, when the liquid permeable sheet 4 is not processed to be stretchable, the nonwoven fabric, the woven fabric, and the like have a large maximum point elongation in the fiber orientation direction, and in a direction orthogonal to the fiber orientation, compared to the fiber orientation direction. The maximum point elongation is small.

  The direction of easiness of elongation of the absorbent body 1 can be controlled by a processing method that allows the liquid permeable sheet 4 to be stretched. For example, when slit processing is performed so as to be orthogonal to the longitudinal direction of the liquid permeable sheet 4, the liquid permeable sheet 4 is easily stretched in the longitudinal direction, and the absorbent body 1 is also easily stretched in the longitudinal direction. In addition, when slit processing is performed according to the longitudinal direction of the liquid permeable sheet 4, the liquid permeable sheet 4 is easily stretched in a direction (lateral direction) perpendicular to the longitudinal direction. It becomes easy to grow.

  Since the absorbent body 1 can be expanded and contracted, the absorbent article including the absorbent body 1 has good fit to the wearer's body. The improvement of the fit property becomes even more remarkable by arranging the absorbent body 1 in a portion having elasticity in the absorbent article, for example, a portion where an elastic member is disposed. In this case, the absorbent body 1 is incorporated into the absorbent article so that the direction having the maximum point elongation of the absorbent body 1 and the direction having the maximum point elongation of the elastic member disposed on the absorbent article coincide with each other. .

  In the absorbent body 1 of the present embodiment, the liquid permeable sheet 4 is slit so that a large number of slits 5 extending in the direction intersecting the orientation direction of the web 2 are formed. In the present embodiment, the slit 5 extends in a direction orthogonal to the orientation direction of the web 2. However, the direction in which the slit 5 extends is not limited to this, and the direction in which the slit 5 extends intersects with the orientation direction of the web 2 as long as the liquid-permeable sheet 4 can substantially extend in the orientation direction of the web 2. It may be a direction.

  Since a large number of slits 5 extending in the direction perpendicular to the orientation direction of the web 2 are formed in the liquid-permeable sheet 4, when the absorbent body 1 is stretched in the orientation direction of the web 2, the slits 5 are formed as shown in FIG. The liquid permeable sheet 4 is elongated by opening. As a result, the entire absorbent body 1 extends.

In order to improve the stretch response of the absorbent body 1, it is preferable that the absorbent body 1 is thin and has a low basis weight. Appropriate values are selected for the thickness and basis weight of the absorbent body 1 according to the specific application of the absorbent article. For example, when using as an absorbent body of a disposable diaper, it is preferable that the web 2 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 is preferably ²⁰ to 500 g / m ² , particularly preferably 50 to 300 g / m ² .

When used as an absorbent body of a sanitary napkin, the web 2 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 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, each web 2 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 is preferably 10 to 500 g / m ² , particularly preferably 15 to 350 g / m ² .

The total basis weight of the web 2 and the superabsorbent polymer 3 in the absorbent body 1 according to the present embodiment is 120 to 400 g / m ² , particularly 150 to 300 g / m when the absorbent body 1 is used for a disposable diaper, for example. m ² is preferable. 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 .

  When the absorber 1 is used for a disposable diaper, the thickness is preferably 1 to 4 mm, particularly 1.5 to 3 mm. When used for a sanitary napkin, it is preferably 0.5 to 3 mm and 1 to 2 mm. When used as an incontinence pad, it is preferably 0.5 to 4 mm, particularly 1 to 3 mm.

  In addition to the superabsorbent polymer, the absorber 1 is made of other particles such as activated carbon, silica, alumina, titanium oxide, and various viscosity minerals (zeolite, sepiolite, bentonite, cancrinite, etc.), inorganic and inorganic particles (deodorant). Agent or antibacterial agent). As the inorganic particles, those partially substituted with metal sites can be used. Alternatively, various organic and inorganic buffering agents, that is, acetic acid, phosphoric acid, citric acid, succinic acid, adipic acid, malic acid, lactic acid and salts thereof may be used alone or in combination, and various amino acids may be included. . The function of these components is to suppress the odor of the liquid absorbed by the absorber 1 and the odor derived from the material. In addition, various organic and inorganic buffer agents have the effect of neutralizing excrement, for example, ammonia generated by decomposition of urine, and keeping the diaper neutral to weakly acidic. Even if there is liquid return of excrement to the skin, the effect on the skin is reduced. Alternatively, the use of a fiber having an ester in its molecular structure such as an acetate fiber as the long fiber web can be expected to prevent alkali damage.

  In addition, hydrophilic fine powder or short fibers can coexist in the web 2 for the purpose of improving the liquid retention and absorption rate 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 spraying the superabsorbent polymer, or may be mixed with the superabsorbent polymer and sprayed on the web at the same time.

  The absorber 1 is desirably flexible. As an evaluation of flexibility, a measured value by a handle-ometer can be used. The measured value is preferably 4N or less, particularly 2N or less. The measuring method using the handle-o-meter conforms to JIS L1096 (flexibility measurement method). An absorbent body cut by 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 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 Scientific Instruments. The average value of the three points is taken as the measured value. When using an absorber as a side part absorber of the diaper shown in FIG. 5 mentioned later, it samples to the magnitude | size of 150 mm in a longitudinal direction, and 50 mm in the width direction. Since the elastic member is usually arranged near the side absorber of the leg flap part, sampling is performed with the leg flap part extended to the maximum, and measurement is performed in a state where the leg flap part is naturally contracted (tension is applied). (Open state).

  Next, 2nd and 3rd embodiment of the absorber of this invention is described, referring FIG.3 and FIG.4. For the points that are not particularly described with respect to these embodiments, the description in detail regarding the first embodiment is applied as appropriate. 3 and 4, the same members as those in FIGS. 1 and 2 are denoted by the same reference numerals.

In the absorbent body 1 of the second embodiment shown in FIG. 3, the liquid permeable sheet 4 is subjected to creping or pleating. These processes are performed so that a large number of ridges or pleats extending in a direction orthogonal to the orientation direction of the web 2 are formed. The creping process is a process performed mainly when the liquid-permeable sheet 4 is made of paper, and is generally performed using a doctor blade. A preferred crepe rate is at least 10%, more preferably 20%. The crepe rate is calculated by the following formula from the amount of change in dimensions after a sample cut to 100 mm × 100 mm in a standard state is dipped in water and then pulled up.
Crepe rate (%) = ((dimension after being immersed in water) / (dimension before being immersed in water) -1) × 100
On the other hand, the pleating process is a process performed mainly when the liquid-permeable sheet 4 is made of a nonwoven fabric. The liquid permeable sheet that has been subjected to creping or pleating has a slack due to the formation of wrinkles or pleats. Therefore, the liquid permeable sheet has extensibility to the extent that the slack is stretched.

  In the absorbent body 1 of the third embodiment shown in FIG. 4, the entire absorbent body 1 is shaped into a waveform. That is, the web 2 and the liquid permeable sheet 4 constituting the absorber 1 are shaped into a waveform. The waveform shaping extends in the orientation direction of the web 2. In order to manufacture the absorbent body 1 having such a shape, an operation of passing the absorbent body made of the web 2 wrapped with the liquid-permeable sheet 4 between a pair of rolls made of gears meshing with each other is performed. As a result, the waveform shaping process is simultaneously applied to the web 2 and the liquid-permeable sheet 4. The liquid permeable sheet 4 that has been subjected to the waveform shaping process has extensibility due to the waveform shape.

  Next, the absorbent article provided with the absorber of the present invention will be described. FIG. 5 shows a perspective view of a disposable diaper as an example of an absorbent article. 6 is a cross-sectional view taken along line VI-VI in FIG. The VI-VI line in FIG. 5 is a part which hits the crotch part in the diaper 10. The diaper 10 shown in FIGS. 5 and 6 includes a liquid-permeable top sheet 11, a liquid-impermeable or water-repellent back sheet 12, and a central absorbent body 13 interposed between both the sheets 11, 12. It is formed substantially vertically long. The liquid-permeable top sheet 11 is formed with a narrower width than the back sheet 12. A water repellent nonwoven fabric 14 is interposed between the central absorbent 13 and the back sheet 12. As these various members constituting the diaper 10, materials known in the technical field can be used.

  The diaper 10 includes waist flaps 17 and 17 extending from the front and rear end edges of the central absorbent body 13 in the front-rear direction. A pair of fastening tapes 18, 18 are attached to the left and right sides of one waist flap 17. A fastening means 18 a for fastening the fastening tape 18 to the back sheet 12 is provided on the surface of the fastening tape 18, that is, the surface of the diaper 10 on the same side as the top sheet 11. Examples of the fastening means 18a include a hook member or a loop member of a mechanical fastener, an adhesive, and the like. Waist elastic strands 17 a and 17 a extending in the width direction of the diaper 10 are arranged in an extended state at the end of the waist flap 17.

  The diaper 10 includes leg flaps 15 and 15 extending laterally from the left and right side edges of the central absorbent body 13. The leg flaps 15 and 15 are provided with leg elastic strands 15a for fitting the diaper 10 to a diaper wearer, respectively. The leg elastic strands 15a are disposed on the left and right sides of the diaper 10 and extend in the longitudinal direction of the diaper 10. The leg elastic strands 15 a are sandwiched and fixed by the back sheet 12 and the water repellent nonwoven fabric 14.

  A pair of three-dimensional guards 16 and 16 are formed on both the left and right sides of the diaper 10 on the surface sheet side. A three-dimensional guard elastic member 16a is arranged at the free ends of the three-dimensional guards 16 and 16 to form a gather.

  As shown in FIG. 6, in the leg flap 15, the absorbent body (hereinafter referred to as a side absorbent body) 1 of the present invention is disposed between the water repellent nonwoven fabric 14 and the sheet constituting the three-dimensional guard 16. Yes. The side absorbent body 1 is arranged so that the orientation direction of the web (the direction orthogonal to the paper surface in FIG. 6) coincides with the extending direction of the leg elastic strands 15a.

  According to the diaper 10 shown in FIGS. 5 and 6, since the liquid that has flowed in the lateral direction of the diaper over the three-dimensional guard 16 is absorbed by the side absorbent body 1 disposed on the leg flap 15, Leakage from the liquid is effectively prevented. Moreover, since the orientation direction of the web in the side part absorbent body 1 corresponds to the longitudinal direction of the diaper 10, the liquid absorbed by the side part absorbent body 1 preferentially diffuses in the longitudinal direction of the diaper 10. This also effectively prevents liquid leakage from around the legs. In particular, since the side absorbent body 1 expands and contracts in the same direction as the leg elastic strands 15a arranged on the leg flap 15, the leg flap 15 fits snugly around the wearer's leg when the diaper 10 is worn. It is difficult for a gap to be formed between the leg flap 15 and the wearer's body. As a result, liquid leakage from around the legs is more effectively prevented. In the case of using a conventional absorbent body mainly composed of pulp, when trying to give stretchability to the absorbent body, it is necessary to use a thicker and more leg elastic strand, thereby producing a large amount of adhesive. An agent was required, causing inconveniences such as stickiness and reduced flexibility. Furthermore, in order to ensure a high absorption capacity, the absorber becomes thick, thereby causing the disadvantage of a decrease in fit. On the other hand, if the stretchable absorbent body of the present invention having a web is used, such inconveniences of conventional absorbent bodies can be solved.

  As a modification of the diaper shown in FIGS. 5 and 6, the diaper shown in FIG. 7 can be exemplified. 7 is a cross-sectional view taken along line VII-VII in FIG. A line VII-VII in FIG. 5 is a portion corresponding to the ventral part of the diaper 10. This portion is a portion where so-called pre-leakage is likely to occur and a high absorption capacity is required for the absorber. In this portion, a hydrophilic web 19 having long fibers is disposed between the central absorbent 13 and the water repellent nonwoven fabric 14. The web 19 connects the left and right side absorbers 1 and 1 with respect to the movement of the liquid. The web 19 is highly oriented in a direction that coincides with the width direction of the diaper 10.

  As the web 19, the same thing as the web 2 which comprises the side part absorber 1 can be used. However, in some cases, the web 19 may not have the superabsorbent polymer embedded and supported, and the long fibers constituting the web 19 may not be crimped.

  According to the diaper 10 shown in FIG. 7, the liquid that has passed over the three-dimensional guard 16 and started to flow in the lateral direction is absorbed by the side absorbent body 1 disposed on the one leg flap 15. The liquid absorbed in one side absorber 1 is quickly diffused toward the central region in the width direction of the diaper 10 by the web 19 connecting the left and right side absorbers 1, 1, and has a high absorption capacity. Guided to the body 13. And it is absorbed by the central absorber 13. In other words, liquid feedback from the side absorber 1 to the central absorber 13 occurs. Furthermore, the liquid passes over the central absorber 13 and reaches the other side absorber 1 where it is absorbed. By such an absorption mechanism of the liquid, the absorption performance of the absorber can be effectively utilized as a whole, and the liquid leakage can be further effectively prevented.

  As mentioned above, although this invention was demonstrated based on the preferable embodiment, this invention is not restrict | limited to the said embodiment, A various change is possible. For example, in FIG.5 and FIG.6, although the side part absorber of the leg flap of the disposable diaper was illustrated as an example of the application to the absorbent article of the absorber of this invention, the application site | part of the absorber of this invention is this. Not limited to. For example, in the diaper shown in FIGS. 5 to 7, the absorbent body of the present invention can be used as a central absorbent body together with the side absorbent body or in place of the side absorbent body. In the diaper shown in FIGS. 5 to 7, the waist flap 17 can be provided with the absorbent body of the present invention. In that case, the absorber is arranged so that the orientation direction of the web in the absorber coincides with the width direction of the diaper. By doing so, the absorbed liquid can be diffused in the width direction of the diaper, and liquid leakage from the waist opening can be effectively prevented. Furthermore, you may apply the absorber of this invention to absorbent articles other than a disposable diaper, for example, absorbers, such as a sanitary napkin and an incontinence pad.

  Moreover, in the absorbent article using the absorbent body according to the present invention, as a method of forming an elastic region in the leg part or the waist part, an elastic member such as a thread rubber is fixed under extension as in the prior art to release the tension. In addition to the method of doing, there is a method of using a stretchable material that can be extended from a natural state. Examples of the stretchable material include a stretchable sheet obtained by combining a stretchable nonwoven fabric with a nonstretchable nonwoven fabric and then cutting the nonstretchable nonwoven fabric. In particular, when the latter elastic material is used, there is an advantage that a mark due to tightening is difficult to touch the skin. When the latter stretchable material is used in combination with a conventional non-stretchable absorber, the stretchable physical properties of the stretchable material are impaired, but the stretchable material is used in combination with the stretchable absorber according to the present invention. As a result, it has become possible to achieve both the prevention of traces and the expansion / contraction characteristics.

  In each of the above embodiments, the fiber material contained in the absorbent body is composed of a hydrophilic long fiber web, but in addition to the long fibers, the stretchability of the absorbent body is not inhibited. Ordinarily used liquid-absorbing fibers such as flap pulp or synthetic resin short fibers may be blended in the absorber.

  Moreover, in the absorbent article which has the absorber which concerns on this invention, you may give the process which can be extended | stretched not only to the liquid-permeable sheet 4 which wraps the web 2, but to a surface sheet. The processing applied to the liquid-permeable sheet and the surface sheet may be the same or different. For example, after the surface sheet and the absorber are combined, the surface sheet may be processed to be stretchable. Alternatively, the liquid-permeable sheet may be subjected to a stretchable process (for example, slit process), and then a top sheet subjected to another stretch process (for example, a pleat process) may be combined. Furthermore, after a stretchable process (for example, slit process) is performed on the liquid-permeable sheet, a stretchable surface sheet, for example, an apertured film or an apertured nonwoven fabric, may be laminated.

[Example 1]
First, a crimped acetate fiber web was prepared. The fiber diameter of this fiber was 2.1 dtex, and the total fiber amount of the web was 25,000 dtex. The web was opened to a width of 100 mm using an air opening device to obtain a spread web. The spread web was stretched to the maximum extension length. Under this condition, a hot melt adhesive was spray coated on the upper surface of the spread web. The coating amount was 5 g / m ² . Subsequently, the superabsorbent polymer particles were uniformly sprayed in a layered manner with a spraying basis weight of 130 g / m ² on the coated surface of the hot melt adhesive. After spreading, the spread state of the spread web was released. As a result, the spread web contracted to obtain a first laminate in which particles of the superabsorbent polymer were embedded and supported in the spread web. Thereafter, the same operation as this operation was repeated once more to obtain a second laminate composed of a web in which superabsorbent polymer particles were embedded and supported. A fluff pulp layer having a basis weight of 50 g / m ² was sandwiched between the first laminate and the second laminate thus obtained.

Furthermore, a fluff pulp layer having a basis weight of 100 g / m ² was disposed under the second laminate. 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 to obtain a central absorbent body. At this time, the crimp rate of the web was 30%, the number of crimps per 1 cm of the fiber was 15, the loading rate of the central absorbent including this web was 30%, and the transfer rate was 11%. The entire central absorbent body is slit in a direction perpendicular to the web orientation direction. The slit processing was performed so as to penetrate through the absorbent body in the thickness direction of the central absorbent body. As shown in FIG. 8, the slits are formed so that one slit has a width of 2 mm, an interval between adjacent slits in the width direction is 2 mm, a slit interval in the longitudinal direction is 2 mm, and the slits are alternately present. did. The slit was formed so that its longitudinal direction was perpendicular to the orientation direction of the web. As a result, the central absorbent body was able to expand and contract in the web orientation direction. In the central absorbent body, a fluff pulp layer having a basis weight of 100 g / m ² is located on the side farthest from the skin. The basis weight of the entire central absorber was 488 g / m ² and the thickness was 2.2 mm. The basis weight of each web was 13 g / m ² .

An air-through nonwoven fabric having a basis weight of 25 g / m ² was used as the surface sheet. The surface sheet was subjected to a hole opening treatment with a metal pin having a diameter of 5 mm. The air-through nonwoven fabric was composed of a core-sheath type composite fiber (thickness: 2.1 dtex, surface treatment with a surfactant and liquid permeability) having a core 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 a blown film in which 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 are uniformly mixed. Then, 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 was obtained. The central absorbent body was arranged so that the orientation direction of the web coincided with the longitudinal direction of the diaper.

[Example 2]
In Example 1, fluff pulp layers were not arranged on the top and bottom of the laminate, the basis weight of each web was set to 60 g / m ^2, and the basis weight 16 g / m ² subjected to hydrophilic treatment instead of the tissue paper that wrapped the laminate. Spunbond-meltblown-spunbond nonwoven (SMS) was used. The slit processing similar to Example 1 was given to this nonwoven fabric. Except these, it carried out similarly to Example 1, and obtained the disposable diaper.

Example 3
In Example 1, a fluff pulp layer is not disposed on the top and bottom of the laminate, the basis weight of each web is 60 g / m ^2, and the weight of the basis weight is 16 g / m ² hydrophilized in a state where the web is under extension. Wrapped with spunbond-meltblown-spunbond nonwoven (SMS). Except these, it carried out similarly to Example 1, and obtained the absorber. The disposable diaper was obtained like Example 2 using the obtained absorber.

Example 4
The side absorber was manufactured as follows. First, a crimped acetate fiber web was prepared. The fiber diameter of this fiber was 2.1 dtex, and the total fiber amount of the web was 25,000 dtex. This web was opened to a width of 50 mm using an air opening device to obtain a spread web. The spread web was stretched to the maximum extension length. Under this condition, a hot melt adhesive was spray coated on the upper surface of the spread web. The coating amount was 5 g / m ² . Subsequently, the superabsorbent polymer particles were uniformly sprayed in a layered manner at a spraying basis weight of 150 g / m ² on the coated surface of the hot melt adhesive. After the completion of spraying, another spread web was layered to release the stretched state. As a result, the spread web contracted and the superabsorbent polymer particles were embedded and held in the spread web. Subsequently, the whole was wrapped with a hydrophilic hydrophilized spunbond-meltblown-spunbond nonwoven fabric (SMS, subjected to slit processing similar to that of Example 3) having a basis weight of 16 g / m ² to obtain a side absorbent body. At this time, the crimp rate of the web was 30%, and the number of crimps per 1 cm was 15. The supporting rate of the side absorber including the web was 95%, the mobility was 11%, the basis weight of the entire side absorber was 173 g / m ² , and the thickness was 1.0 mm. The basis weight of each web was 13 g / m ² . This side part absorber was integrated in the disposable diaper obtained in Example 1, and the disposable diaper shown in FIG. 5 was obtained. The side absorber was arranged so that the orientation direction of the web coincided with the longitudinal direction of the diaper.

[Comparative Example 1]
100 parts by weight of the opened fluff pulp and 100 parts by weight of the superabsorbent polymer were uniformly mixed in an air stream to obtain a mixture having a total basis weight of 520 g / m ² . The basis weight of the fluff pulp and superabsorbent polymer were respectively 260 g / m ^2. The obtained mixture was wrapped with a tissue paper having a basis weight of 16 g / m ² to obtain a central absorbent body. Between the mixture and tissue paper, 5 g / m ² of hot melt pressure-sensitive adhesive was spray-coated and adhered. The basis weight of the entire absorbent body was 562 g / m ² and the thickness was 4.3 mm. Except these, it carried out similarly to Example 1, and obtained the disposable diaper.

[Comparative Example 2]
The side absorber was manufactured as follows. 100 parts by weight of the opened fluff pulp and 100 parts by weight of the superabsorbent polymer were uniformly mixed in an air stream to obtain a mixture having a total basis weight of 300 g / m ² . The basis weights of the fluff pulp and the superabsorbent polymer were 150 g / m ² , respectively. The obtained mixture was wrapped with a tissue paper having a basis weight of 16 g / m ² to obtain an absorbent. Between the mixture and tissue paper, 5 g / m ² of hot melt pressure-sensitive adhesive was spray-coated and adhered. The basis weight of the entire absorbent body was 342 g / m ² and the thickness was 2.6 mm. This side part absorber was integrated in the disposable diaper obtained by the comparative example 1, and the disposable diaper was obtained.

[Performance evaluation]
About the absorber in the diaper obtained by the Example and the comparative example, the absorption capacity, the softness | flexibility, and structural stability were evaluated with the following method. Moreover, fit property was evaluated about the diaper. The results are shown in Table 1 below.

[Absorption capacity]
The obtained absorbent body was fixed to a 45 ° inclined plate, and a certain amount of physiological saline was repeatedly injected at regular intervals at a position 200 mm from the upper end of the absorbent body. The injection amount from the end on the lower side of the absorber to the leakage 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)

[Flexibility]
The absorber was subjected to a handle-ometer test, and the flexibility was evaluated according to the following criteria. The smaller the value, the better the contactability and fit.
○: 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.

[Structural stability]
(1) At the time of dry The center part of the absorber produced to 50 mm x 200 mm was cut | disconnected, and the absorber of 50x100 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 embedding supportability of the superabsorbent polymer was evaluated according to the following criteria.
Of the mixed superabsorbent polymers,
◯: The ratio of the superabsorbent polymer that has fallen out exceeds 0% and is 10% or less.
(Triangle | delta): The quantity of the superabsorbent polymer which dropped out exceeds 10% and is 25% or less.
X: The amount of the superabsorbent polymer dropped off exceeds 25%. (2) When wet The absorbent body was almost uniformly absorbed on the entire surface of the absorbent body cut to 50 × 200 mm, and then the absorbent body was gently lifted. At that time, it was visually determined whether or not the absorber was destroyed.
○: The ratio of the superabsorbent polymer dropped off is 10% or less, and the absorber is not destroyed.
(Triangle | delta): The ratio of the superabsorbent polymer which dropped out exceeds 10% and is 25% or less, and there is no destruction of an absorber.
X: The ratio of the superabsorbent polymer dropped off exceeds 25%, or the absorber is destroyed.

[Fitness]
The obtained diapers were attached to 5 infants (7 to 14 months) using M size diapers, and their mother's impression was heard.
○: It fits neatly and the crotch is not stiff.
Δ: A little clear.
X: There is a feeling of muffledness, it is not refreshing, and it does not fit.

It is a perspective view which shows one Embodiment of the stretchable absorber of this invention. It is a perspective view which shows the state which extended the absorber shown in FIG. It is sectional drawing which shows another embodiment of the stretchable absorber of this invention. It is sectional drawing which shows another embodiment of the stretchable absorber of this invention. It is a perspective view which shows the disposable diaper provided with the stretchable absorber of this invention. It is the VI-VI sectional view taken on the line in FIG. It is the VII-VII sectional view taken on the line in FIG. FIG. 6 is a schematic diagram showing a slit formation state in Example 2.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Absorber 2 Hydrophilic web having long fibers 3 Polymer layer 4 Liquid permeable sheet 5 Slit

Claims (6)

An absorbent body in which a web of hydrophilic long fibers embedded and supported with a superabsorbent polymer is wrapped with a liquid-permeable sheet,
The hydrophilic long fibers have a crimp rate of 10 to 60%, and the web of the long fibers is highly oriented in the plane direction of the absorber,
A stretchable absorbent body in which the liquid-permeable sheet is stretchable and the absorbent body is stretchable as a whole.   The stretchable absorbent body according to claim 1, wherein the liquid permeable sheet is processed so that the sheet can be stretched, and the absorbent body as a whole is stretchable in the orientation direction of the web.   The stretchable absorbent body according to claim 2, wherein the liquid permeable sheet is slit so that a large number of slits extending in a direction intersecting with the orientation direction of the web are formed.   The stretchable absorbent body according to claim 2, wherein the liquid-permeable sheet is subjected to creping or pleating so that a large number of ridges or pleats extending in a direction intersecting with the orientation direction of the web are formed.   The stretchable absorbent body according to claim 2, wherein the liquid permeable sheet is subjected to a waveform shaping process extending in the orientation direction of the web. An absorbent article comprising the absorber according to any one of claims 1 to 5.

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