CN1331661C - Three-dimensional sheet materials - Google Patents

Abstract

The three-dimensional sheet material (10) of the present invention is the first fiber layer (1) containing three-dimensionally crimped fibers, and the second fiber layer (2) containing three-dimensionally crimped fibers of the same or different type as the fibers. layered. The two fiber layers (1, 2) are partially joined at many joints (3) and integrated in the thickness direction. The first fiber layer (1) protrudes between the joints (3, 3), forming many convex portions (4). Also, the three-dimensional sheet material (10) of the present invention is formed by laminating the aforementioned first fiber layer (1) and the aforementioned second fiber layer (2), and the three-dimensional crimp contained in the second fiber layer (2) The degree of curling of the fibers is higher than that of the three-dimensionally crimped fibers contained in the first fiber layer (1), and the apparent density of the second fiber layer (2) is higher than the apparent density of the first fiber layer (1) high.

Description

Three-dimensional sheet material

technical field

The present invention relates to a three-dimensional sheet material composed of a nonwoven fabric having a bulky structure having many protrusions on one surface.

In addition, the present invention also relates to a multilayer sheet material that has high liquid absorbency and can quickly absorb liquid. The sheet material of the present invention is particularly preferably used as a top sheet and an absorber of absorbent products such as sanitary napkins and disposable diapers, for example.

Background technique

The applicant has previously proposed the following three-dimensional sheet material: there is a first layer and a second layer adjacent to it, the first layer and the second layer are partially joined by a joint part of a prescribed pattern, and the first layer is between the joint parts. A three-dimensional shape is formed, and the second layer is composed of a material exhibiting elastic behavior, and the entire sheet material exhibits elastic behavior and has air permeability (see JP-A-2002-187228). The three-dimensional sheet material has high recovery properties when stretched in the planar direction and high recovery properties when compressed in the thickness direction, and can be suitably used as a constituent material of disposable absorbent products or a wiper for people and objects. However, the requirements for stretch recovery and compression recovery are increasing.

Known a kind of dustproof cover (dust cloth): constituted by the first layer and the second layer, these first layer and the second layer are laminated integrally with each other, and wherein, the first layer adopts the latent crimp fiber that exhibits crimp , and the unidirectional carding machine fiber web (card web) composed of thermal fusion bonded fibers between the fibers that bond the latent crimped fibers, the exposed surface is smooth; An intersecting card web made of fibers that do not substantially shrink under temperature has convex portions that are substantially parallel to each other formed on the exposed surface (see JP-A-2001-89961). In this boot, since the first layer and the second layer are joined over their entire surfaces, it is not easy to increase the protrusion. In addition, it is not easy to increase the degree of freedom of the pattern (design) produced by the convex part.

It is known that an upper layer of a continuous filament bundle is superimposed on a lower layer of a continuous filament bundle, and partially melt-bonded with a joining line, and a surface sheet of an absorbent product is sheeted (see JP-A-2002-65738 ). In this surface sheet, by making the lower layer more hydrophilic and dense than the upper layer, the liquid permeability is improved and liquid return is prevented. As a means of increasing the density, the number of crimps of the continuous filaments is differentiated. However, since the constituent fibers are continuous filaments, it is not easy to increase the bulkiness of the sheet, and the sheet lacks softness.

It is also known to manufacture a non-woven fabric wiper with many undulations at least on one side by a method consisting of at least one layer of hydrophilic fiber web and at least one layer of thermally crimped hydrophobic fibers. The process of the laminated body composed of nets; on the surface of the support with continuous planar parts, intermittent and independently distributed many protrusions and/or concaves, and many fine drainage holes, spray the aforementioned laminated body from the fine hole nozzle Spraying high-pressure water, while interlacing the fibers of the aforementioned two nets, rearranging them to obtain a non-woven fabric with uneven distribution density of fibers in the plane direction of the aforementioned laminate; dehydrating the aforementioned non-woven fabrics and/or After drying, heat treatment is performed to crimp the aforementioned synthetic fibers (see JP-A-8-60509). This type of wiper has the same disadvantages as those of the boot described in Patent Document 2, since the two fiber webs are bonded over their entire surfaces.

Contents of the invention

Therefore, an object of the present invention is to provide a bulky sheet material having high recovery properties when stretched in the planar direction and high recovery properties when compressed in the thickness direction.

Another object of the present invention is to provide a fluffy and soft sheet material that has high liquid absorbency and can quickly absorb liquid.

The present invention achieves the aforementioned object by providing a three-dimensional sheet material (hereinafter referred to as the first invention, referring to the invention), which is a first fiber layer containing three-dimensionally crimped fibers, and containing the The second fiber layer of the same or different three-dimensionally crimped fiber is laminated (laminated). The aforementioned two fiber layers are partially joined at many joints and integrated in the thickness direction. 1. The fiber layer protrudes to form many protrusions.

Also, the present invention achieves the aforementioned object by providing a sheet material (hereinafter referred to as the second invention, referring to this invention) comprising a first fiber layer containing three-dimensionally crimped fibers and a The second fiber layer of the same or different type of three-dimensionally crimped fiber is laminated, and the degree of crimp of the three-dimensionally crimped fiber contained in the second fiber layer is higher than that of the three-dimensionally crimped fiber contained in the first fiber layer The degree of crimp is high, and the apparent density of the second fiber layer is higher than that of the first fiber layer.

Also, the present invention provides an absorbent article comprising a liquid-permeable surface layer, a liquid-impermeable leak-proof layer, and a liquid-retentive absorbent layer interposed between the two layers, wherein the surface layer or the absorbent layer , using the following sheet material: the first fiber layer containing three-dimensionally crimped fibers and the second fiber layer containing three-dimensionally crimped fibers of the same or different type as the fibers are laminated, and the second fiber layer contains The degree of crimp of the three-dimensionally crimped fibers is higher than that of the three-dimensionally crimped fibers contained in the first fiber layer, and the apparent density of the second fiber layer is higher than that of the first fiber layer; the aforementioned sheet material The said 2nd fiber layer is arrange|positioned so that it may face the said leakproof layer side.

Description of drawings

Fig. 1 is a perspective view showing a preferred embodiment of the sheet material of the first invention and the second invention.

Fig. 2 is a sectional view taken along line II-II in Fig. 1 .

Detailed ways

Hereinafter, the present invention will be described based on preferred embodiments thereof with reference to the drawings. Fig. 1 shows a perspective view of one embodiment of the three-dimensional sheet material of the present invention. Fig. 2 is a sectional view taken along line II-II in Fig. 1 .

The sheet material 10 shown in FIG. 1 is composed of a nonwoven fabric having a multilayer structure including a first fiber layer 1 and a second fiber layer 2 adjacent thereto. The first fiber layer 1 is composed of an aggregate of fibers. On the other hand, the second fiber layer 2 is composed of an aggregate of fibers of different types and/or blends from those constituting the first fiber layer 1 . The first fiber layer 1 and the second fiber layer 2 are partially joined by many joining parts 3 . In other words, the first fiber layer 1 and the second fiber layer 2 are not bonded over their entire surfaces. However, even in areas where they are not joined, the two fiber layers are in contact. In the present embodiment, the joint parts 3 are formed discretely and discontinuously in small circles, forming a rhombus grid-like configuration pattern as a whole. The joining portion 3 is densified, and has a smaller thickness and higher density than other portions of the sheet material 10 .

The joining portion 3 is formed by thermal fusion bonding of the first fiber layer 1 and the second fiber layer 2 . Both fiber layers are integrated in the thickness direction by this junction part 3. The joint portion 3 in this embodiment is circular, but the shape of the joint portion 3 may also be oval, triangular, or rectangular, or a combination thereof. In addition, the joining portion may be formed in a continuous shape, for example, a linear shape such as a straight line or a curved line.

The area ratio of the junction part 3 to the area of the three-dimensional sheet material 10 (the area of the junction part 3 per unit area of the average three-dimensional sheet material 10) also depends on the specific use of the three-dimensional sheet material 10 and the like. From the viewpoint of sufficiently increasing the bond between the first fiber layer 1 and the second fiber layer 2 and sufficiently forming a convex three-dimensional shape to exhibit bulkiness, it is preferably 6-90%, particularly preferably 10-70%.

In the three-dimensional sheet material 10, the first fiber layer protrudes between the joining parts 3, forming many convex parts 4. In this embodiment, the three-dimensional sheet material 10 has many enclosed areas formed by being surrounded by joints 3 formed by diamond-shaped grid-like arrangements. In this enclosed area, the first fiber layer 1 is as shown in Figure 2. Protruding as shown, the convex portion 4 is formed. The convex part 4 in this embodiment is comprised in the shape of a dome. Its interior is filled with fibers constituting the first fiber layer 1 . The engaging portion 3 is a concave portion facing the convex portion 4 . On the other hand, in the second fiber layer 2, the joints 3 are generally flat or protruded a little (see FIG. 2). Viewed as a whole, the three-dimensional sheet material 10 has a structure as follows: the side of the second fiber layer 2 is flat or even slightly convex, and there are many concavo-convex parts on the side of the first fiber layer 1 .

The first fiber layer 1 contains three-dimensionally crimped fibers. As mentioned above, since the convex portion 4 is constituted by the first fiber layer 1, the first fiber layer 1 containing three-dimensionally crimped fibers means that the convex portion 4 contains three-dimensionally crimped fibers. When the convex part 4 contains the three-dimensionally crimped fiber, the recovery property at the time of compressing the convex part 4 becomes high. In addition, when the three-dimensional sheet material 10 is impregnated with a liquid, the overflow of the convex portion 4 is small. Therefore, the three-dimensional sheet material 10 can be suitably used as a constituent material of a disposable absorbent product or a wet wiper for people and objects. Furthermore, since the three-dimensionally crimped fibers can pinch and hold fibrous dust at the crimped portion, when the three-dimensional sheet material 10 is used as a wiper, the fibrous dust is highly collected. In addition, relatively large dust such as bread crumbs is easily retained in the recesses between the protrusions 4, so it is also preferable to use the three-dimensional sheet material 10 as a wiper from this point of view. In addition, the recovery property of the first fiber layer 1 when it is stretched in the planar direction becomes high.

Examples of the three-dimensionally crimped fibers include latently crimped fibers exhibiting crimps, especially chemical fiber staple fibers of latently crimped fibers exhibiting crimps, and mechanically crimped fibers, especially mechanically crimped fibers of chemical fiber staple. In particular, from the standpoint of high compression recovery of the convex portion 4 and high stretch recovery of the first fiber layer 1, the three-dimensionally crimped fibers are preferably formed from latent crimped fibers exhibiting crimps, especially latent crimps exhibiting crimps. It is composed of chemical fiber staple fibers of natural fibers. By using short chemical fibers, it is easier to increase the bulkiness of the sheet material 10 and to exhibit a soft feeling than when continuous filaments are used. From this point of view, the fiber length is preferably about 2-150 mm, especially about 5-100 mm. The latently crimped fiber exhibiting crimps is in a crimped state (coil-like). As latent crimped fibers, the fineness is preferably about 1 to 7 decitex (dtex). The latently crimped fiber is, for example, an eccentric core-sheath type composite fiber or a side by side type composite fiber composed of two types of thermoplastic polymer materials having different shrinkage rates. Examples thereof include fibers described in JP-A-9-296325 and JP-A-2759331. As an example of two types of thermoplastic polymer materials having different shrinkage ratios, for example, a combination of ethylene-propylene random copolymer (EP) and polypropylene (PP) is ideal from the viewpoint of the flexibility of the three-dimensional sheet material 10 .

The first fiber layer 1 may consist of 100% of three-dimensionally crimped fibers, or may contain other fibers. As another fiber, the fiber which does not heat-shrink substantially at the crimp start temperature of the said latent crimpable fiber is mentioned, for example. Specifically, there are heat-shrinkable fibers that do not substantially heat-shrink at the crimp initiation temperature of the aforementioned latently crimpable fibers, and fibers that do not substantially heat-shrinkable. In particular, it is preferable to contain heat-melt-adhesive fibers. Thereby, the surface strength of the convex part 4 improves, and fluff is effectively prevented. When fibers other than three-dimensionally crimped fibers are contained in the first fiber layer 1, the amount of three-dimensionally crimped fibers is preferably 30% by weight or more with respect to the weight of the first fiber layer 1, particularly preferably 50-90% by weight. .

Like the first fiber layer 1, the second fiber layer 2 also contains three-dimensionally crimped fibers. As the three-dimensionally crimped fibers contained in the second fiber layer 2, latent crimped fibers exhibiting crimps can be preferably used. The latently crimped fibers may be of the same or different type from the latently crimped fibers contained in the first fiber layer 1 . Regarding the details of the latently crimped fibers contained in the second fiber layer 2 , the description regarding the latently crimped fibers contained in the first fiber layer 1 can be appropriately applied. When the second fiber layer 2 contains fibers that are three-dimensionally crimped, the recovery property when the second fiber layer 2 is stretched in the planar direction becomes high.

The second fiber layer 2 may consist of 100% of three-dimensionally crimped fibers, or may contain other fibers. Examples of other fibers include the same fibers as other fibers contained in the first fiber layer 1 . When fibers other than three-dimensionally crimped fibers are contained in the second fiber layer 2, the amount of three-dimensionally crimped fibers is preferably 50% by weight or more with respect to the weight of the second fiber layer 2, particularly preferably 70-90% by weight. .

As described above, since both the first fiber layer 1 and the second fiber layer 2 contain three-dimensionally crimped fibers, both of these layers have high recovery properties when stretched in the planar direction. As a result, even as the three-dimensional sheet material 10 as a whole, the recovery property when stretched in the planar direction becomes high. Therefore, when the three-dimensional sheet material 10 is used, for example, as a wiper, the followability to the unevenness of the target surface is good. In addition, when the three-dimensional sheet material 10 is used, for example, as a constituent member of an absorbent product, the followability to the user's motion is improved, the suitability of the absorbent product is improved, and liquid leakage can be effectively prevented.

The three-dimensional sheet material 10 has a low-density structure, and its compression deformability is sufficiently large when compressed in the thickness direction. In more detail, it also depends on the specific use of the three-dimensional sheet material 10, but from the perspective of giving the three-dimensional sheet material 10 a bulky feeling, and improving the compression deformation and thus improving the softness, the three-dimensional sheet material 10 can be used at a pressure of 0.49cN/cm ² The apparent density is preferably 5-50 kg/m ³ , particularly preferably 10-30 kg/m ³ . Moreover, from the aspect of giving the three-dimensional sheet material 10 with sufficient strength and the shape retention of the convex three-dimensional shape, the apparent density of the three-dimensional sheet material 10 under the pressure of 49.0cN/ ^cm is preferably 20-130kg/ m ³ , particularly preferably 30-120 kg/m ³ . The pressure of 0.49 cN/cm ² is approximately equal to the pressure during wearing of the absorbent product, and the pressure of 49.0 cN/cm ² is approximately equal to the pressure when body pressure is applied while wearing the absorbent product.

The apparent density of the three-dimensional sheet material 10 under the pressure of 0.49cN/ ^cm2 and the pressure of 49.0cN/ ^cm2 is divided by the thicknesses under the pressure of 0.49cN/ ^cm2 and 49.0cN/ ^cm2 described later. Its unit weight is calculated.

The thickness of the three-dimensional sheet material 10 also depends on its specific use, but from the perspective of bulkiness and compression deformation, the thickness under the pressure of 0.49cN/ ^cm2 is preferably 1.5-10mm, especially preferably 2-6mm, 49.0cN The thickness under pressure per cm ² is preferably 0.5-5 mm, particularly preferably 1.0-2.5 mm.

The thickness under pressure was measured using a compression change rate measuring method (KES method). As a measuring device, a KES FB3-AUTO-A automatic compression tester manufactured by Riki-Tec Co., Ltd. was used. The initial thickness was measured by setting the pressure plate load to 0.49 cN/cm ² . The pressure is measured by changing from the initial thickness T1 (0.49cN/cm ² ) to the loaded thickness T2 (49cN/cm ² ) at a certain speed (1mm/sec). The detection of compressive load is performed by a high-sensitivity load cell. This load cell can detect 0.1 cN/cm ² .

The thickness under a pressure of 0.49 cN/cm ² can also be measured by the following method. First, a plate smaller in size than the measurement piece (circular plate with a diameter of 5.6 cm, 12.4 g) was placed on the measuring table, and the position of the upper surface of the plate in this state was used as a reference point A for measurement. Next, the plate was removed, a measurement piece (10 cm×10 cm) was placed on the measuring table, and the plate was further placed thereon. Let B be the upper surface position of the board in this state. The thickness of the three-dimensional sheet material 10 is obtained from the difference between A and B. A laser displacement meter [manufactured by Keyence Co., Ltd., CCD laser displacement sensor LK-080] was used as a measurement device, but a thickness gauge of a dial indicator type may also be used. However, when using a thickness gauge, adjust the measuring force of the measuring machine and the weight of the plate to a pressure of 0.49 cN/cm ² .

The three-dimensional sheet material 10, about the aforementioned thickness T1 under pressure of 0.49cN/ ^cm and the thickness T2 under pressure of 49.0cN/ ^cm From the viewpoint of high followability and high cleaning efficiency, the compression rate defined by the following formula (1) is preferably 30-85%, particularly preferably 40-70%. In addition, when the three-dimensional sheet material 10 is used as a constituent member of an absorbent product, it is preferable from the viewpoint of improving conformability to the user's body shape and movement, and improved feel.

Compression rate (%)=(T1-T2)/T1×100 (1)

From the viewpoint of making the three-dimensional sheet material 10 exhibit sufficient compression deformation and bulkiness, the unit weight of the three-dimensional sheet material 10 is preferably 20-200 g/m ² , particularly preferably 40-150 g/m ² . The unit weight is to cut the three-dimensional sheet material 10 into a size of 50mm×50mm or more to prepare a measurement piece, measure the weight of the measurement piece using an electronic balance with a minimum scale of 1 mg, and obtain it by converting it into a unit weight.

Next, a preferable manufacturing method of the three-dimensional sheet material 10 of this embodiment is demonstrated. The three-dimensional sheet material 10 is obtained by the following method: the first fiber assembly containing latent crimped fibers and the second fiber assembly containing latent crimped fibers of the same or different type as the latent crimped fibers are laminated, and the two fibers The aggregates are partially heat-fused and bonded to form a laminate, and then the laminate is heat-treated to crimp the aforementioned latently crimpable fibers contained in each fiber aggregate, and to thermally shrink each fiber aggregate in its in-plane direction. The first fiber aggregate and the second fiber aggregate are obtained by forming a first fiber layer and a second fiber layer, respectively. In addition, during thermal shrinkage, the area shrinkage ratio of the second fiber aggregate is greater than the area shrinkage ratio of the first fiber aggregate, so that the first fiber layer protrudes to form the convex portion 4 .

Each fiber aggregate is preferably composed of a fiber web produced using a carding machine. In order to locally heat-melt bond the two fiber assemblies to obtain a laminate, for example, ultrasonic embossing or heat embossing is used. The heat treatment temperature of the laminate is set to be equal to or higher than the crimp initiation temperature of the latent crimpable fibers contained in each fiber aggregate. For the heat treatment, for example, hot air blowing (wind-through processing), infrared irradiation, and the like are used. The areal shrinkage rate of each fiber aggregate is represented by the following formula (2), where the reference area before shrinkage is denoted as S ₀ , and the area after shrinkage of the reference area is denoted as S ₁ .

Area shrinkage (%)=(S ₀ -S ₁ )/S ₀ ×100(2)

In order to make the area shrinkage ratio of the second fiber aggregate larger than the area shrinkage ratio of the first fiber aggregate, for example, the following methods (1) to (4) are exemplified.

(1) The first fiber aggregate contains fibers that do not substantially shrink by heat at the heat treatment temperature of the above-mentioned laminate (hereinafter also referred to as non-heat-shrinkable fibers). On the other hand, non-heat-shrinkable fibers are not included in the second fiber aggregate, and the second fiber aggregate is constituted only of latently crimped fibers. When the non-heat-shrinkable fibers are contained in the first fiber aggregate, crimping of the latently crimpable fibers contained in the first fiber aggregate is prevented. Therefore, during the heat treatment of the laminate, the degree of crimp of the latently crimped fibers in the first fiber assembly is relatively lower than that of the latently crimped fibers in the second fiber assembly. As a result, the area shrinkage ratio of the second fiber aggregate is larger than the area shrinkage ratio of the first fiber aggregate.

(2) Each of the first fiber aggregate and the second fiber aggregate contains non-heat-shrinkable fibers, and the content ratio of the non-heat-shrinkable fibers in the first fiber aggregate is higher than that of the non-heat-shrinkable fibers in the second fiber aggregate. The content ratio of shrinkage fiber is high. In this case, crimping of potentially crimpable fibers contained in each fiber aggregate is prevented. The first fiber aggregate having a high content ratio of non-heat-shrinkable fibers is largely hindered. Therefore, when the laminate is heat-treated, the degree of crimping of the latently crimped fibers in the first fiber assembly is relatively lower than that of the second fiber assembly. As a result, the area shrinkage ratio of the second fiber aggregate is larger than the area shrinkage ratio of the first fiber aggregate.

(3) Before laminating the first fiber aggregate and the second fiber aggregate, heat embossing is preliminarily performed on only the first fiber aggregate. Accordingly, the movement of the latently crimped fibers contained in the first fiber aggregate is restricted by the fusion points formed by embossing. Therefore, when the laminate is heat-treated, the degree of crimping of the latently crimped fibers in the first fiber assembly is relatively lower than that of the second fiber assembly. As a result, the area shrinkage ratio of the second fiber aggregate is larger than the area shrinkage ratio of the first fiber aggregate.

(4) As the latently crimpable fibers contained in the first fiber assembly, fibers having a crimp initiation temperature higher than that of the latently crimpable fibers contained in the second fiber assembly are used. When a fiber with a higher crimp initiation temperature is heat-treated at the same temperature as compared to a fiber with a lower crimp initiation temperature, the fiber with a higher crimp initiation temperature is less likely to be crimped. Therefore, during the heat treatment of the laminate, the degree of crimp of the latently crimped fibers in the first fiber assembly is relatively lower than that of the latently crimped fibers in the second fiber assembly. As a result, the area shrinkage ratio of the second fiber aggregate is larger than the area shrinkage ratio of the first fiber aggregate.

Among the methods (1)-(4) above, method (1) may be combined with methods (3) and/or (4). In addition, it is also possible to combine method (2) with method (3) and/or (4).

When the thus-obtained three-dimensional sheet material is used as a wiper, since the convex portion 4 contains three-dimensionally crimped fibers, it is excellent in collecting fine fibrous dust. In addition, relatively large dust such as bread crumbs can also be collected by the recesses between the protrusions 4 . Furthermore, since the recovery property when stretched in the planar direction and the recovery property when compressed in the thickness direction are high, the followability to the surface to be cleaned is high, and the cleaning efficiency is improved. Furthermore, the mountability to the cleaning tool is also improved. In addition, since the fibers that are three-dimensionally crimped are also included in the second fiber layer 2, the second fiber layer 2 side can also be used for cleaning if necessary. That is, it can be used as a double-sided wiper.

In addition, since the three-dimensional sheet material contains three-dimensionally crimped fibers in the convex portion 4, its rigidity is high. As a result, even if it is impregnated with liquids such as water and detergent, the convex dome-shaped structure can be reliably maintained. , Even if it is formed as a wet wiper, the cleaning performance will not be reduced. Moreover, even in the case of being used as a constituent member (such as a surface sheet) of an absorbent product, the dome-shaped structure of the convex portion 4 can be maintained after the body fluid is infiltrated or absorbed, so it is possible to prevent skin discomfort and airtightness. , rash.

The first invention is not limited to the above-mentioned embodiments. For example, the interior of the convex portion 4 in the three-dimensional sheet material 10 of the above-mentioned embodiment is filled with fibers constituting the first fiber layer 1, but instead of this, the convex portion 4 may be configured in a hollow state.

Next, the second invention will be described. Regarding the second invention, the detailed description about the first invention described above can be suitably applied to the points that are not particularly described.

A preferred embodiment of the second invention is the same as the sheet material shown in Figs. 1 and 2 shown as a preferred embodiment of the first invention. Therefore, a preferred embodiment of the second invention will be described with reference to FIG. 1 and FIG. 2 . However, it should be noted that, in the second invention, the first fiber layer does not need to protrude to form many protrusions. Therefore, in the following description, the sheet material 10 shown in FIGS. 1 and 2 is simply referred to as the sheet material 10 .

In the sheet material 10 according to the second embodiment of the present invention, the degree of crimp of the three-dimensionally crimped fibers contained in the second fiber layer 2 is higher than that of the three-dimensionally crimped fibers contained in the first fiber layer. Accordingly, the apparent density of the second fiber layer 2 is higher than the apparent density of the first fiber layer 1 . As a result, a gradient occurs in the apparent density of the sheet in the thickness direction of the sheet 10 . Due to this gradient, a force of sucking liquid is generated from the first fiber layer 1 to the second fiber layer, and when the liquid is discharged into the first fiber layer, it is quickly absorbed. This makes it difficult for liquid to remain on the surface of the first fiber layer 1 . The force of absorbing the liquid becomes higher especially when force is applied to the sheet material, specifically, when force such as stretching and twisting is applied to the sheet material.

The apparent density p2 of the second fibrous layer 2 and the apparent density p1 of the first fibrous layer 1 are preferably p2/p1=1.1 or more, more preferably 1.1-5, from the viewpoint that the force of absorbing liquid can be fully realized, Particularly preferred is 1.3-5. Apparent density of each layer: in the first fiber layer 1, p1=4-40 kg/m ³ is preferred, and 8-25 kg/m ³ is particularly preferred. In the second fiber layer 2, p2 is preferably 20-200 kg/m ³ , particularly preferably 25-80 kg/m ³ . In addition, from the viewpoint of imparting a bulky feeling to the sheet material 10, improving compression deformability, and further improving softness and softness, the apparent density of the entire sheet material 10 is preferably 8-80 kg/m ³ , particularly preferably 10-50 kg. /m ³ .

Both the first fiber layer 1 and the second fiber layer 2 contain three-dimensionally crimped fibers as main constituent fibers. As the three-dimensionally crimped fiber, the same fiber as that used in the first invention can be used.

In the sheet material 10 of the present embodiment, since the first fiber layer 1 and the second fiber layer 2 all contain three-dimensionally crimped fibers as in the first invention, there is an advantage that these layers are stretched in the plane direction. The response time is high.

As other advantages that both the first fiber layer 1 and the second fiber layer 2 contain three-dimensionally crimped fibers, high recovery and cushioning feeling when the sheet material 10 is compressed are listed. In particular, since the convex portion 4 contains three-dimensionally crimped fibers, the recovery and cushioning feeling when the convex portion 4 is compressed become high. As a result, the recovery and cushioning feeling of the sheet material as a whole are also high. In addition, when the sheet material 10 is impregnated with a liquid, the overflow of the convex portion 4 is small.

In the present invention, the crimp degree of the three-dimensionally crimped fibers contained in the second fiber layer 2 is higher than that of the three-dimensionally crimped fibers contained in the first fiber layer, which means that the fibers contained in the second fiber layer 2 The number of crimps of the three-dimensionally crimped fibers is greater than the number of crimps of the three-dimensionally crimped fibers contained in the first fiber layer 1, and/or the volume diameter of the three-dimensionally crimped fibers contained in the second fiber layer 2 (curl generation coil-shaped diameter) is smaller than the coil diameter of the three-dimensionally crimped fibers contained in the first fiber layer 1 . The crimp number is measured according to JIS L1015. The roll diameter was determined from electron micrographs of the fibers.

In order to make the three-dimensionally crimped fibers contained in the second fiber layer 2 have a higher degree of crimp than the three-dimensionally crimped fibers contained in the first fiber layer, various methods can be used. For example, in the case of including latently crimped fibers exhibiting crimps as three-dimensionally crimped fibers, the following method can be used. In addition, in the following description, when simply referring to a latently crimped fiber, depending on the context, it refers to either a latently crimped fiber exhibiting crimp or a latently crimped fiber before exhibiting crimp.

(a) In the case of using different kinds of latent crimped fibers in the first fiber layer 1 and the second fiber layer 2, in the state before the latent crimped fibers contained in each layer are crimped, make the latent crimped fibers in the In the case of crimping under the same conditions, as the latent crimpable fibers contained in the second fibrous layer 2, fibers that are more likely to cause crimp than the latent crimpable fibers contained in the first fibrous layer 1 are used. Specifically, as the latently crimpable fibers contained in the second fiber layer 2 , fibers having a lower crimping temperature than the latently crimpable fibers contained in the first fiber layer 1 are used. Alternatively, the crimping temperature is the same, but the number of crimps is large and/or the crimp diameter is small, as the latent crimped fibers contained in the second fiber layer 2 . In order to increase the number of crimps and/or reduce the crimp diameter, for example, the degree of eccentricity of the eccentric core-sheath composite fiber may be increased, and the ratio of the core component and the sheath component may be adjusted.

(b) In the case of using the same kind of latent crimping fibers in the first fibrous layer 1 and the second fibrous layer 2, the first fibrous layer 1 contains a substance that prevents the crimping of the latent crimping fibers contained in the first fibrous layer 1. fiber. Specifically, (1) the first fiber layer 1 contains latent crimped fibers and ordinary fibers that do not crimp and shrink, and the second fiber layer 2 is composed of latent crimped fibers, and the latent crimps contained in the first fiber layer 1 The crimping of the fibers is more hindered than the crimping of the latent crimping fibers contained in the second fiber layer 2. In addition, (2) both the first fiber layer 1 and the second fiber layer 2 contain latent crimping fibers and ordinary fibers that do not crimp and shrink, and the blending ratio of the ordinary fibers in the second fiber layer 2 is the first The compounding ratio of the ordinary fiber in the fiber layer 1 is low. In this case, the crimping of the latently crimpable fibers contained in the first fiber layer 1 is more hindered than the crimping of the latently crimpable fibers contained in the second fiber layer 2 .

In the case where the first fiber layer 1 or the second fiber layer 2 contains ordinary fibers that hinder the crimping of the latent crimping fibers, as the ordinary fibers, for example, there are substantially no Heat-shrinkable fibers. Specifically, there are heat-shrinkable fibers that do not substantially heat-shrink at the crimp initiation temperature of latent crimpable fibers, and fibers that do not substantially heat-shrinkable. In particular, heat-melt-bonding fibers are preferably used. As a result, in addition to adjusting the degree of crimping of the potentially crimping fibers, the surface strength of the convex portion 4 is improved, effectively preventing fluffing. The compounding ratio of the ordinary fiber contained in the first fiber layer 1 is preferably 10-90% by weight, particularly preferably 30-70% by weight, from the viewpoint of improving the surface strength of the convex portion 4 . The proportion of ordinary fibers contained in the second fiber layer 2 is lower than that of the first fiber layer, preferably 0-50% by weight, particularly preferably 0-30% by weight.

In the sheet material 10 of this embodiment, the hydrophilicity of the second fiber layer 2 is higher than that of the first fiber layer 1 . Due to this situation and the previously described density gradient, the sheet material 10 of the present embodiment has a stronger force to absorb liquid from the first fiber layer 1 to the second fiber layer, and when the liquid is discharged into the first fiber layer 1, is absorbed more rapidly. The degree of hydrophilicity of the first fiber layer 1 and the second fiber layer 2 can be judged by, for example, the size of the surface liquid flow length measured by the following method. When the length of the surface liquid flow is small, the hydrophilicity is high, and when the length of the surface liquid flow is large, the hydrophilicity is small.

[Measuring method of surface liquid flow length]

The measurement was performed in a temperature and humidity environment of 20° C. and 65% RH. Sheet materials, sanitary napkins, etc. are allowed to stand still in this environment for 12 hours or more so that the above-mentioned temperature and humidity are sufficiently balanced.

(I) Preparation of measurement samples

Only the top sheet was removed from the sanitary napkin Lorie Sarosaroku Siyon Win Genashi (Pharmaceutical Sales Name: Lorie Nr) manufactured by Kao Corporation. In its place, the sheet material is coiled around the sanitary napkin, secured on the leak barrier side. In this case, when measuring the surface flow length of the first fiber layer, the first fiber layer is directed toward the surface. When measuring the surface flow length of the second fiber layer, the second fiber layer is directed toward the surface.

(II) Determination of surface liquid flow length

Set up the test bench for the inclined plane with an acrylic plate. The inclination angle of the acrylic board is set appropriately (for example, 45 degrees). The angle is measured with a goniometer so that the slope error is ±1 degree. Also, make the acrylic sheet horizontal in a direction perpendicular to the direction of inclination. Next, a measurement sample was placed on the acrylic plate. Measure the surface of the sample two or three times with light pressure such as a ruler to eliminate the floating of the sheet material. In this state, 1 g of simulated blood was dripped onto the sheet material over 10 seconds using a microtube pump. At this time, the tip of the dropping tube was 10 mm above the dropping position of the measurement sample. The dripping position of the measurement sample is a position close to the upper side by 150 mm from the lower end portion of the measurement sample, and is the center portion of the measurement sample in the width direction. As simulated blood, ion-exchanged water colored with 0.1 g/l of edible red No. 2 was used. The distance from the position where the sheet material is first wetted by the simulated blood to the position where the simulated blood is first absorbed by the sheet material is measured, and its value is taken as the surface flow length. The measurement was carried out 5 times, and the average value was obtained. When the simulated blood reached the lower end of the measurement sample without being absorbed even once in the five measurements, the surface flow length of the sheet material was also set at 150 mm. In addition, at the moment when 1 g of simulated blood is dropped, the simulated blood does not flow through the surface of the sheet material at all, but is completely absorbed, and when the surface flow length cannot be measured, measure the wetness of the sheet material at the moment when the simulated blood does not spread. The distance from the upper end to the lower end of the wetted part is taken as the surface flow length.

In order to make the hydrophilicity of the second fiber layer 2 higher than that of the first fiber layer 1, for example, the first fiber layer 1 is mainly composed of hydrophobic fibers, and on the other hand, the first fiber layer is mainly composed of hydrophilic fibers. 2 fiber layers 2 get final product. In the case where the 1st fiber layer 1 and the 2nd fiber layer 2 are all made of hydrophobic fibers, only the constituent fibers of the 2nd fiber layer 2 are given a hydrophilic oil agent, or the constituent fibers of the two fiber layers are all given a hydrophilic oil. The hydrating oil agent, in this case, as the hydrophilizing oil agent imparted to the constituent fibers of the second fiber layer 2, a hydrophilizing oil agent having a higher degree of hydrophilization than that imparted to the constituent fibers of the first fiber layer 1 is used. The oil can be. The hydrophilic oil agent can be coated on the fiber surface, or kneaded into the fiber. When the hydrophilizing oil agent is applied to the fiber surface, it may be applied to the raw fiber, or may be applied after forming a fiber assembly from the raw fiber.

The thickness of the sheet material 10 of the second invention also depends on its specific use, but is preferably 0.7-13 mm, particularly preferably 1.3-10 mm, from the viewpoint of bulkiness and compression deformability. Regarding the thickness of each layer, the thickness of the first fiber layer 1 is preferably 0.5-10 mm, particularly preferably 1-8 mm. The thickness of the second fiber layer 2 is preferably 0.2-3 mm, particularly preferably 0.3-2 mm. The thickness was measured under a pressure of 0.49 cN/cm ² in the same manner as described above regarding the method of measuring the apparent density.

From the viewpoint of allowing the sheet material 10 of the second invention to exhibit sufficient compression deformability and bulkiness, the sheet material 10 preferably has a unit weight (basis weight) of 15-200 g/m ² , particularly preferably 25-150 g/m ² . From the same viewpoint, the unit weight of the first fiber layer 1 is preferably 5-120 g/m ² , particularly preferably 10-100 g/m ² , and the unit weight of the second fiber layer 2 is preferably 10-150 g/m ² , Particularly preferred is 15-100 g/m ² . The unit weight is obtained by cutting the sheet material 10 into a size of 50 mm×50 mm or more to prepare a measurement piece, measuring the weight of the measurement piece using an electronic balance with a minimum scale of 1 mg, and converting it into a unit weight.

A preferable manufacturing method of the sheet material 10 of the second invention is the same as that of the first invention. In addition, the method of making the area shrinkage ratio of the second fiber aggregate larger than the area shrinkage ratio of the first fiber aggregate is also the same as that of the first invention. (methods (1)-(4) explained for the first invention). In addition, by adopting the method (1)-(4), the degree of crimp of the three-dimensionally crimped fibers contained in the second fiber layer 2 can be made higher than that of the three-dimensionally crimped fibers contained in the first fiber layer 1. .

The sheet material 10 thus obtained has a density gradient from the first fiber layer 1 to the second fiber layer 2 . Therefore, this sheet material 10 is used as a surface layer (surface sheet) of an absorbent article having a liquid-permeable surface layer, a liquid-impermeable leak-proof layer, and a liquid-retentive absorbent layer interposed therebetween, and When the surface on the side of the first fiber layer 1 is used as the surface facing the skin, and the second fiber layer 2 is arranged facing the leak-proof layer side, the liquid excreted into the first fiber layer 1 is quickly absorbed. In addition, it is difficult for liquid to remain on the surface of the first fiber layer 1 . When the protrusions 4 are provided on the first fiber layer 1, the contact area with the skin is small and cushioning properties are obtained, so an absorbent product with a good wearing feeling can be obtained. When it is used as an absorbent body of an absorbent product, and the second fiber layer 2 is arranged facing the leak-proof layer side, the first fiber layer 1 also quickly absorbs the liquid entering from the surface sheet and moves to the second fiber layer 2. , so it is possible to provide absorbent articles with high absorbency.

In addition, when the sheet material 10 is used as a wiper, the same effect as that of the first invention can be obtained. When the sheet material 10 is formed as a top sheet of an absorbent product or a wet wipe impregnated with an aqueous detergent, the same effect as that of the first invention can be obtained.

The second invention is not limited to the above-mentioned embodiments. For example, in the above-mentioned embodiment, all the three-dimensionally crimped fibers contained in the first fiber layer 1 are less crimped than the three-dimensionally crimped fibers contained in the second fiber layer 2, but instead of this, in In the limit that the apparent density of the second fiber layer is higher than the apparent density of the first fiber layer, the first fiber layer 1 may contain a small amount of three-dimensionally crimped fibers contained in the second fiber layer to have the same degree of crimp. Three-dimensionally crimped fibers at or above this level.

In addition, the sheet material of the above-mentioned embodiment is a three-dimensional sheet material having many protrusions, but instead of this, a flat sheet material having no protrusions may be used. Such a sheet material, for example, is prepared in advance by separately making a first fiber layer containing three-dimensionally crimped fibers and a second fiber layer containing three-dimensionally crimped fibers of the same or different type as the fibers, and using a hot-melt adhesive or the like. The adhesive is obtained by bonding two layers.

In addition, the constituent elements of the first invention and the second invention may be mutually substituted or combined as appropriate. For example, in the three-dimensional sheet material of the first invention, the constituent requirements of the second invention may also be combined, that is, the degree of crimp of the three-dimensionally crimped fibers contained in the second fiber layer is higher than that of the three-dimensional crimp contained in the first fiber layer. The degree of crimp of the obtained fibers is high, and the apparent density of the second fiber layer is higher than that of the first fiber layer.

The present invention will be described in more detail by way of examples below. However, the scope of the present invention is not limited to such embodiments.

[Example 1]

The latent crimp fiber CPP (trade name, 2.2dtex x 51mm, melting temperature (melting point) of the sheath component resin: 145°C) manufactured by Yamato Bosei Co. ^{, Ltd.} Fiber web. The fiber web was subjected to heat embossing (embossing) processing using a heat embossing roll (145±10° C.) to manufacture a first fiber aggregate. The embossed area ratio was 28%.

(2) Production of the second fiber aggregate

The latent crimp fiber CPP (trade name, 2.2dtex x 51mm, melting temperature (melting point) of the sheath component resin: 135°C) manufactured by Yamato Bosei Co. ^{, Ltd.} 2nd fiber assembly.

(3) Manufacture of three-dimensional sheet material

The first fiber aggregate and the second fiber aggregate were superimposed, and the two fiber aggregates were partially bonded by ultrasonic embossing to obtain a laminate (laminate). The shape of each junction part produced by embossing is circular, and its arrangement pattern is a rhombus grid as shown in FIG. 1 . In the hot air oven, blow hot air at 130±10°C for 5-10 seconds in the airflow mode. Accordingly, the latently crimpable fibers contained in each fiber aggregate are crimped, and each fiber aggregate is shrunk in the in-plane direction. At this time, the crimping of the latently crimped fibers contained in the first fiber aggregate is hindered by the previous heat embossing process, so the area shrinkage ratio of the second fiber aggregate is higher than the area shrinkage ratio of the first fiber aggregate. high. As a result, in the first fiber layer formed of the first fiber aggregate, many protrusions are formed between the joining points. The three-dimensional sheet material thus obtained had a unit weight of 96.0 g/m ² , and the area ratio of the junction point was 7% of the area of the three-dimensional sheet material.

[Example 2]

As the first fiber aggregate, the following fiber body was used: 50% by weight of latent crimped fiber CPP (trade name, 2.2 dtex × 51 mm, sheath component resin melting temperature (melting point) : 135°C), and contains 50% by weight of core-sheath type heat-melting adhesive fiber NBF (SH) (trade name, 2.2dtex×51mm) manufactured by Yamato Shozen Co., Ltd., and has a unit weight of 15g/m ² . This fiber assembly is not heat embossed. Other than that, it carried out similarly to Example 1, and obtained the three-dimensional sheet material. In the heat treatment of the laminate, the crimping of the latently crimped fibers contained in the first fiber aggregate is hindered by the presence of thermally fused bonding fibers, so the area shrinkage ratio of the second fiber aggregate is greater than that of the first fiber aggregate. High shrinkage. The three-dimensional sheet material thus obtained had a unit weight of 93.8 g/m ² , and the area ratio of the junction point was 7% of the area of the three-dimensional sheet material.

[Comparative example 1]

As the first fiber assembly, a hydrophilic spunbond nonwoven fabric manufactured by Toray Saehan Inc. (main component: polypropylene, unit weight 13 g/m ² ) was used, and a three-dimensional fiber was obtained in the same manner as in Example 1. sheet material. During the heat treatment of the laminate, the spunbonded nonwoven fabric as the first fiber assembly does not shrink. The three-dimensional sheet material thus obtained had a unit weight of 86.2 g/m ² , and the area ratio of the junction point was 7% of the area of the three-dimensional sheet material.

[Comparative example 2]

As the first fiber assembly, the hydrophobic spun-bonded nonwoven fabric JB20R (trade name, main component: polypropylene, unit weight 20 g/m ² ) manufactured by Toray Saehan Inc. was used, except that it was the same as in Example 1. To obtain three-dimensional sheet material. During the heat treatment of the laminate, the spunbonded nonwoven fabric as the first fiber assembly does not shrink. The three-dimensional sheet material thus obtained had a unit weight of 100.4 g/m ² , and the area ratio of the junction point was 7% of the area of the three-dimensional sheet material.

[Comparative example 3]

As the first fiber assembly, the core-sheath type thermal fusion bonded fiber NBF (SH) (trade name, 2.2dtex × 51mm) manufactured by Yamato Sangzaki Co., Ltd. was used with the air-through method (blowing hot air, air through). A three-dimensional sheet material was obtained in the same manner as in Example 1 except that the card fiber web as the raw material was heat-treated air-permeable nonwoven fabric (basis weight: 14 g/m ² ). The air-permeable nonwoven fabric as the first fiber assembly does not shrink during the heat treatment of the laminate. The three-dimensional sheet material obtained in this way had a unit weight of 91.3 g/m ² , and the area ratio of the joint point was 7% of the area of the three-dimensional sheet material.

[Performance evaluation]

Regarding the three-dimensional sheet materials obtained in Examples and Comparative Examples, the dust collection rate, liquid return (wet back), liquid spreading area, and thickness when wet were measured by the following methods. These results are shown in Table 1 below.

[Acquisition rate of dust]

Specific amounts of the following dusts A-C were individually scattered on a flow ring of 1 mm×1 mm. Each three-dimensional sheet material was attached to a Kuitsukuru wiper (trade name) manufactured by Kao Co., Ltd., and the wear ring was reciprocated and wiped 5 times. Thereafter, the weight of the dust attached to the three-dimensional sheet material (the number of dust B) was measured, and the collection rate (%) was calculated.

Dust A: bread flour (particle size 1-1.4mm), 0.2g

Dust B: hair (length 10cm, diameter about 100μm), 10 pieces x 5 times

Dust C: 7 kinds of dust for JIS test, 0.3g

[Return volume]

The absorber was taken out from a sanitary napkin Lorie (trade name) manufactured by Kao Co., Ltd., each three-dimensional sheet material was placed on it, and a perforated acrylic sheet (load: 4.9 cN/cm ² ) was placed thereon. 6 g of defibrated horse blood (manufactured by Nippon Biotest) was injected through the holes of the acrylic plate. After 1 minute had elapsed from the time when the blood was completely absorbed, the acrylic plate was removed. Next, overlap 20 pieces of filter paper on the three-dimensional sheet material, and add about 65 cN/cm ² load, so that the filter paper absorbs the returning blood. After 5 minutes, the load was removed, and the weight of 20 filter papers was measured. Calculate the difference from the weight of the filter paper before absorbing blood, and use this value as the liquid return amount.

[Liquid expansion area]

The absorber was taken out from a sanitary napkin Rolie (trade name) manufactured by Kao Co., Ltd., each three-dimensional sheet material was placed on it, and a perforated acrylic sheet (load 5 g/cm ² ) was placed thereon. 6 g of defibrated horse blood (manufactured by Nippon Biotest) was injected through the holes of the acrylic plate. After 1 minute had elapsed from the time when the blood was completely absorbed, the acrylic plate was removed. Next, add a load of about 65cN/cm ² on the three-dimensional sheet material. After 5 minutes, the load was removed, and an image analyzer was used to measure the expanded area of the blood on the surface of the three-dimensional sheet material.

[thickness when wet]

The three-dimensional sheet material was immersed in ion-exchanged water, taken out, and placed on filter paper overlapping five sheets. Add a load of 65.3cN/cm ² to the three-dimensional sheet material to make the filter paper absorb the remaining moisture. After 1 minute, the load was removed, and the thickness under a load of 0.49 cN/cm ² was measured by the aforementioned KES method. The thickness before immersion in ion-exchanged water was also measured under the same conditions.

Table 1

Example Comparative example 1 2 1 2 3 Dust capture rate (%) Dust A 67.5 70.3 28.5 29.3 56.0 Dust B 88.0 100.0 32.0 34.0 84.0 dust C. 42.3 61.4 44.3 41.7 51.7 Liquid return volume (mg) 2270 1826 2410 1831 2344 Liquid expansion area (cm ² ) 10.57 10.75 14.10 18.99 15.60 Initial thickness (mm) 3.30 2.42 3.52 3.33 3.27 Thickness when wet (mm) 3.08 2.33 3.09 3.10 2.72 Thickness reduction rate (%) 6.67 3.72 12.22 6.91 16.80

From the results shown in Table 1, it is clear that the three-dimensional sheet material (the product of the present invention) of each example, compared with the sheet material of the comparative example, has better collection of fibrous dust such as hair and relatively large dust such as bread flour. excellent. In addition, it was found that the three-dimensional sheet materials of each embodiment have less liquid return and a smaller liquid expansion area. It was also found that the three-dimensional sheet material of each example has a small thickness reduction rate when wet, and can maintain the shape of the convex portion well even when wet.

The three-dimensional sheet material of the present invention is excellent in recovery when stretched in the plane direction and recovery when compressed in the thickness direction. In addition, the rigidity of the convex portion is high, and the convex shape is well maintained even when it is wet. Fibrous dust is excellent in the convex portion, and relatively large dust such as bread crumbs is excellent in the inter-convex portion. Moreover, the three-dimensional sheet material of the present invention has a small amount of liquid return and a small area of liquid expansion, so when it is used as a top sheet of an absorbent product, it prevents the excreted liquid from returning to the user's skin, and also prevents the liquid from returning to the user's skin. To make the skin sticky.

In addition, the sheet material of the present invention is a fluffy and soft material that has high liquid absorbency and can quickly absorb liquid.

Claims (15)

1. three-dimensional sheet materials, its the 2nd fibrage lamination by the fiber that the 1st fibrage that contains the fiber that solid curled and the solid that contains or xenogenesis of the same race with this fiber have been curled forms, aforementioned two fibrages engage partly at many junction surfaces, integrated at thickness direction, the 1st fibrage protrudes between each junction surface, forms many protuberances.

2. the three-dimensional sheet materials of putting down in writing according to claim 1, the aforementioned fibers that the solid that contains in the 2nd fibrage has been curled constitutes by presenting curling potential crimping property fiber, and the aforementioned fibers that the solid that contains in the 1st fibrage has been curled is by presenting curling potential crimping property fiber or the manufactured fiber of machine crimp constitutes.

3. the three-dimensional sheet materials of putting down in writing according to claim 2, it is to make by following method: the 1st fiber assembly that will contain the potential crimping property fiber, the 2nd fiber assembly lamination with the latent crimp fiber that contains or xenogenesis of the same race with this latent crimp fiber, make the two fiber assemblies bonding laminated body that constitutes of heat fusing partly, follow this laminated body of heat treatment, make the aforementioned potential crimping property fiber crimp that is contained in each fiber assembly, make the direction thermal contraction in its face of each fiber assembly, form the 1st fibrage and the 2nd fibrage respectively by the 1st fiber assembly and the 2nd fiber assembly, and when the three-dimensional sheet materials thermal contraction, percentage reduction of area by making the 2nd fiber assembly is greater than the percentage reduction of area of the 1st fiber assembly, the 1st fibrage is protruded, form many aforementioned protuberances.

4. the three-dimensional sheet materials of putting down in writing according to claim 3 contains under aforementioned heat treated temperature the fiber of not thermal contraction in fact in the 1st fiber assembly, do not contain this fiber in the 2nd fiber assembly.

5. the three-dimensional sheet materials of putting down in writing according to claim 3, all containing under aforementioned heat treated temperature the fiber of not thermal contraction in fact among the 1st fiber assembly and the 2nd fiber assembly, in the 1st fiber assembly this fiber contain ratio in the 2nd fiber assembly this fiber contain proportional height.

6. the three-dimensional sheet materials of putting down in writing according to claim 3 before with the 1st fiber assembly and the 2nd fiber assembly lamination, is implemented the processing of hot pressing line in advance to the 1st fiber assembly.

7. the three-dimensional sheet materials of putting down in writing according to claim 3, the curling beginning temperature of the potential crimping property fiber that contains in the 1st fiber assembly is than the curling beginning temperature height of the potential crimping property fiber that contains in the 2nd fiber assembly.

8. the three-dimensional sheet materials of putting down in writing according to claim 1, the amount of crimp height of the fiber that the amount of crimp of the fiber that the solid that contains in the 2nd fibrage has been curled has been curled than the solid that contains in the 1st fibrage, the 2nd fibrolaminar apparent density is than the 1st fibrolaminar apparent density height.

9. the three-dimensional sheet materials of being put down in writing according to Claim 8 all contains the aforementioned fibers that the staple fiber that presents curling potential crimping property fiber has curled as solid among the 1st fibrage and the 2nd fibrage; Aforementioned potential crimping property fiber that contains in the 1st fibrage and the aforementioned potential crimping property fiber that contains in the 2nd fibrage are xenogenesis; Under the state before the aforementioned potential crimping property fiber crimp that each layer contained, make the occasion of this potential crimping property fiber crimp under the same conditions, the aforementioned potential crimping property fiber that the aforementioned potential crimping property fiber that the 2nd fibrage is contained is contained than the 1st fibrage takes place to curl easily.

10. the three-dimensional sheet materials of being put down in writing according to Claim 8 all contains the aforementioned fibers that the staple fiber that presents curling potential crimping property fiber has curled as solid among the 1st fibrage and the 2nd fibrage; Aforementioned potential crimping property fiber that contains in the 1st fibrage and the aforementioned potential crimping property fiber that contains in the 2nd fibrage are of the same race; The 1st fibrage contains aforementioned potential crimping property fiber and general fibre curling or that shrink does not take place, and the 2nd fibrage only is made of aforementioned potential crimping property fiber or contains aforementioned potential crimping property fiber and general fibre curling or that shrink does not take place; The 2nd fibrage contains the occasion of aforementioned potential crimping property fiber and aforementioned general fibre, and the cooperation ratio of the described general fibre of cooperation ratio in the 1st fibrage of the described general fibre in the 2nd fibrage is low.

11. the three-dimensional sheet materials of being put down in writing according to Claim 8, wherein the 2nd fibrolaminar water-wetness is than the 1st fibrolaminar water-wetness height.

12. the three-dimensional sheet materials of putting down in writing according to claim 11, wherein the 1st fibrage and the 2nd fibrage constitute by hydrophobic fibre, only the 2nd fibrolaminar formation fiber is given the hydrophiling finish or all given the hydrophiling finish to two fibrolaminar formation fibers, as the hydrophiling finish of giving to the 2nd fibrolaminar formation fiber, used than the high finish of giving to the 1st fibrolaminar formation fiber of hydrophiling finish hydrophiling degree.

13. sheet material, its the 2nd fibrage lamination by the fiber that the 1st fibrage that contains the fiber that solid curled and the solid that contains or xenogenesis of the same race with this fiber have been curled forms, the amount of crimp height of the fiber that the amount of crimp of the fiber that the solid that contains in the 2nd fibrage has been curled has been curled than the solid that contains in the 1st fibrage, the 2nd fibrolaminar apparent density is than the 1st fibrolaminar apparent density height.

14. according to the sheet material that claim 13 is put down in writing, wherein said two fibrages engage partly at many junction surfaces, and are integrated at thickness direction, the 1st fibrage protrudes between each junction surface, forms many protuberances.

15. absorbing products, it possesses the superficial layer of permeability for liquids, the absorbed layer of impermeable application of anti-leakage layers of liquid and the liquid retainability between this is two-layer, wherein, as aforementioned surfaces layer or absorbed layer, use following sheet material: by the 1st fibrage that contains the fiber that solid curled, the 2nd fibrage lamination of the fiber that has curled with the solid that contains or xenogenesis of the same race with this fiber forms, the amount of crimp height of the fiber that the amount of crimp of the fiber that the solid that contains in the 2nd fibrage has been curled has been curled than the solid that contains in the 1st fibrage, the 2nd fibrolaminar apparent density is than the 1st fibrolaminar apparent density height; Aforementioned sheet material is configured to, and aforementioned the 2nd fibrage is towards aforementioned application of anti-leakage layers side.