JP4865635B2 - Stretchable laminated sheet and manufacturing method thereof - Google Patents

Description

  The present invention relates to a stretchable laminated sheet obtained by bonding a moisture permeable film to a stretchable nonwoven fabric and a method for producing the same.

Conventionally, a laminated sheet in which a nonwoven fabric and a moisture permeable film are laminated is known (for example, see Patent Documents 1 and 2 below). According to such a laminated sheet, since the surface of the nonwoven fabric has a good touch and the surface of the moisture permeable film has a moisture permeable and leak proof property, a moisture permeable and leak proof sheet having a good touch can be realized.
However, in the laminated sheets described in Patent Documents 1 and 2, since a non-elastic nonwoven fabric and a moisture permeable film are laminated, a certain degree of extensibility is exhibited, but no contractility is exhibited. Therefore, if the sheet shape is deformed by extension, the deformation is maintained as it is. For example, when the laminated sheet is used for an object that involves shape deformation, the followability to the shape deformation is poor, and the feeling of adhesion, fit, and the like are reduced. Specifically, when used for a product worn on a person or the like, the followability to posture deformation is poor.
It is also conceivable to form a “stretchable laminated sheet” that exhibits stretchability as the whole laminated sheet by using a stretchable nonwoven fabric as the nonwoven fabric in the laminated sheet.

JP 2002-316359 A JP 2002-307627 A

However, in the stretchable laminated sheet formed without special measures, there is a problem that the moisture permeable film is torn.
For example, in a stretchable laminated sheet in which a bowl-shaped moisture-permeable film is partially bonded to a stretchable nonwoven fabric, the moisture-permeable film is not easily broken at the time of manufacture. Stress concentration occurs at the joint between the film and the non-woven fabric, and the film is easily broken.
Further, when a flat laminated sheet formed by joining an elastic nonwoven fabric and a moisture permeable film is formed into a wave shape by gear stretching, and the stretch property of the entire laminated sheet is to be expressed, the moisture permeable film is produced at the time of gear stretching. Is excessively stretched locally, and the moisture-permeable film is easily broken.

  Accordingly, an object of the present invention is to provide a stretchable laminated sheet in which a moisture permeable film is bonded to a stretchable nonwoven fabric. An object of the present invention is to provide a method for producing a stretchable laminated sheet, which can easily produce the stretchable laminated sheet while preventing tearing.

  In the present invention, a substantially non-elastic first non-elastic fiber layer and a second non-elastic fiber layer are respectively disposed on both surfaces of an elastic fiber assembly, and the adjacent elastic fiber assembly and the non-elastic fiber layer are adjacent to each other. Is a stretch laminate sheet in which a moisture permeable film is entirely joined to the first non-elastic fiber layer in the stretch nonwoven fabric joined by thermal fusion, wherein the moisture permeable film, the first The non-elastic fiber layer, the elastic fiber assembly, and the second non-elastic fiber layer integrally have a wavy shape, and the moisture permeable film side and the second non-elastic layer in the stretchable laminated sheet. On the elastic fiber layer side, a plurality of first concave stripes and second concave stripes formed in parallel with each other are formed, and the first concave stripes are such that the outer surface of the moisture permeable film is bent with respect to the base surface. It is formed in a recess, and the second recess is the second inelastic fiber Is obtained by achieving the above object by providing a stretchable laminated sheet having the outer surface of is formed recessed smoothly relative to the base surface.

  Further, according to the present invention, a substantially inelastic first inelastic fiber layer is disposed on at least one surface of the elastic fiber assembly, and the elastic fiber assembly and the first inelastic fiber layer are heat-sealed. A moisture-permeable film is entirely bonded to the first non-elastic fiber layer in the stretchable nonwoven fabric bonded by the step, and the moisture-permeable film, the first non-elastic fiber layer, and the elastic fiber aggregate are It is a method for producing a stretchable laminated sheet that has an integrally wavy shape and is formed with a plurality of first and second recesses arranged in parallel on the moisture permeable film side and the opposite side, respectively. After the step of forming the flat laminated sheet by joining the first inelastic fiber layer and the moisture permeable film in the stretchable nonwoven fabric, or simultaneously with the step, the large diameter portion and the small diameter portion are alternately arranged. Using a stretching device provided with a pair of concavo-convex rolls formed The performed stretched into flat laminated sheet, forming said first concave and the second concave stripes is obtained by achieving the above object by providing a method of manufacturing the stretchable laminated sheet.

According to the stretchable laminated sheet of the present invention, in the stretchable laminated sheet in which the moisture permeable film is bonded to the stretchable nonwoven fabric, the moisture permeable film is hardly broken even if the stretch is repeated.
Moreover, according to the manufacturing method of the elastic laminated sheet of this invention, the said elastic laminated sheet can be manufactured easily, preventing the tearing of a moisture-permeable film.

Hereinafter, the stretchable laminated sheet of the present invention will be described based on preferred embodiments with reference to the drawings. The schematic diagram which shows the cross-section of 1st Embodiment of the stretchable laminated sheet of this invention is shown by FIG.
The stretchable laminated sheet 1 according to the first embodiment is a stretchable laminated sheet in which the moisture permeable film 3 is entirely bonded to the stretchable nonwoven fabric 2. More specifically, the stretchable laminate sheet 1 is substantially formed on both surfaces of the elastic fiber assembly 21. Are provided with an inelastic first inelastic fiber layer 22 and a second inelastic fiber layer 23, respectively, and the adjacent elastic fiber aggregate 21 and the inelastic fiber layers 21 and 23 are joined by thermal fusion. This is a stretchable laminated sheet in which the moisture permeable film 3 is entirely bonded to the first inelastic fiber layer 22 in the stretchable nonwoven fabric 2.
The elastic fiber aggregate 21 in the first embodiment is an elastic fiber layer formed in a layer shape.

The moisture permeable film 3, the first inelastic fiber layer 22, the elastic fiber assembly 21, and the second inelastic fiber layer 23 have an integrally wavy shape.
On the moisture permeable film 3 side and the second inelastic fiber layer 23 side in the stretchable laminated sheet 1, a plurality of first concave stripes 41 and second concave stripes 42 arranged in parallel are formed.

  First, the stretchable nonwoven fabric 2 will be described. In the stretchable nonwoven fabric 2 in the first embodiment, the elastic fiber layer 21, the first inelastic fiber layer 22, and the second inelastic fiber layer 23 have the fiber form of the constituent fibers of the elastic fiber layer 21. In this state, the entire surface is joined by heat fusion at the fiber intersection. That is, at the interface between the elastic fiber layer 21 and the non-elastic fiber layers 22 and 23 and in the vicinity thereof, the intersection of the constituent fiber of the elastic fiber layer 21 and the constituent fiber of the non-elastic fiber layers 22 and 23 is thermally fused. , Substantially uniformly bonded over the entire surface. When the elastic fiber layer 21 and the non-elastic fiber layers 22 and 23 are bonded to each other, the floating between the elastic fiber layer 21 and the non-elastic fiber layers 22 and 23 occurs. It is prevented that a space is formed apart. When floating occurs between the two layers, there is no sense of unity between the elastic fiber layer 21 and the non-elastic fiber layers 22 and 23, and the texture tends to decrease. The stretchable nonwoven fabric 2 in this embodiment is a stretchable nonwoven fabric having a multi-layered structure with a sense of unity, such as a single layer of nonwoven fabric.

“The state in which the constituent fibers of the elastic fiber layer 21 maintain the fiber form” means that even if heat, pressure, or the like is applied, most of the constituent fibers of the elastic fiber layer 21 are in a film form or a film-fiber structure. The state which is not deformed. Sufficient breathability is provided to the stretchable nonwoven fabric 2 because the constituent fibers of the elastic fiber layer 21 are in a state of maintaining the fiber form.
In the elastic fiber layer 21, the intersections of the constituent fibers are thermally fused in the layer. Similarly, in the non-elastic fiber layers 22 and 23, the intersections of the constituent fibers are thermally fused in the layers.

  In at least one of the two non-elastic fiber layers 22 and 23, a part of the constituent fibers enter the elastic fiber layer 21, and / or a part of the constituent fibers of the elastic fiber layer 21 is at least one. The inelastic fiber layers 22 and 23 are in a state of entering. By being in such a state, integration of the elastic fiber layer 21 and the non-elastic fiber layers 22 and 23 is promoted, and it is more effectively prevented that floating occurs between both layers. As a result, both layers are combined in a form following the surface of each layer. Part of the constituent fibers of one inelastic fiber layer enters the elastic fiber layer 21 and remains there, or penetrates through the elastic fiber layer 21 and reaches the other inelastic fiber layer. For example, in the non-elastic fiber layers 22 and 23, when a surface connecting the surface fibers on the side facing the elastic fiber layer 21 of the two surfaces is assumed macroscopically, a fiber space formed inside the layer from this surface In addition, some of the constituent fibers of the elastic fiber layer 21 have entered. Further, on the two surfaces of the elastic fiber layer, when the surfaces connecting the surface fibers are assumed macroscopically, the constituent fibers of the non-elastic fiber layers 22 and 23 are formed in fiber spaces formed inside these layers from these surfaces. A part of has entered. In particular, when the constituent fibers of the non-elastic fiber layers 22 and 23 enter the elastic fiber layer 21 and remain there, it is preferable that the constituent fibers are further entangled with the constituent fibers of the elastic fiber layer 21. Similarly, when the constituent fiber of one inelastic fiber layer penetrates through the elastic fiber layer 21 and reaches the other inelastic fiber layer, the constituent fiber of one inelastic fiber layer is It is preferably entangled with the constituent fibers of the inelastic fiber layer. This is confirmed by the fact that a space is not substantially formed between the layers when the cross section in the thickness direction of the stretchable nonwoven fabric is observed with an SEM, a microscope or the like. The term “entanglement” here means a state where fibers are sufficiently intertwined, and a state where the fiber layers are simply overlapped is not included in the confounding.

  Whether or not they are entangled can be determined, for example, by the following method. From the state in which the fiber layers are simply overlapped, the force required to peel the fiber layers is measured. Separately, after the fiber layers are overlapped and an air-through method without heat fusion is applied thereto, the force for peeling the fiber layers is measured. If two forces are compared and a substantial difference is recognized between the two, it can be determined that they are entangled.

  In order to allow the constituent fibers of the non-elastic fiber layer to enter the elastic fiber layer and / or to allow the constituent fibers of the elastic fiber layer to enter the non-elastic fiber layer, the constituent fibers of the non-elastic fiber layer and the constituent fibers of the elastic fiber layer It is preferable that at least one of the non-elastic fiber and the elastic fiber is in a web state (a state where heat fusion is not performed). From the viewpoint of allowing the constituent fibers to enter other layers, the fiber layer in the web state is preferable because the short fibers have a higher degree of freedom than the long fibers.

  In order to allow the constituent fibers of the non-elastic fiber layer to enter the elastic fiber layer and / or to allow the constituent fibers of the elastic fiber layer to enter the non-elastic fiber layer, it is preferable to use the air-through method. By using the air-through method, the constituent fibers can be made to enter the opposing fiber layer, and the constituent fibers can be easily made to enter from the opposing fiber layer. Further, by using the air-through method, it becomes easy to allow the constituent fibers of the inelastic fiber layer to enter the elastic fiber layer while maintaining the bulkiness of the inelastic fiber layer. In the case where the constituent fibers of one inelastic fiber layer are allowed to penetrate the elastic fiber layer and reach the other inelastic fiber layer, it is preferable to use the air-through method in the same manner. In particular, it is preferable to laminate an inelastic fiber layer in a web state with the elastic fiber layer and use the air-through method. In this case, in the elastic fiber layer, the constituent fibers may be heat-sealed or may not be heat-sealed.

Furthermore, as will be described later in the manufacturing method, by performing the air-through method under specific conditions, and for improving the flow of hot air, the breathability of the stretchable nonwoven fabric, particularly the breathability of the elastic fiber layer is high. By doing, a fiber can be made to penetrate more uniformly. A method other than the air-through method, for example, a method of spraying steam can also be used. It is also possible to use a spunlace method, a needle punch method, etc., but in this case, the bulkiness of the inelastic fiber layer is impaired, or the constituent fibers of the elastic fiber layer appear on the surface of the stretchable nonwoven fabric 2. And the texture tends to decrease.
In particular, when the constituent fibers of the inelastic fiber layer are entangled with the constituent fibers of the elastic fiber layer, it is preferable that they are entangled only by the air-through method.

  In order to entangle the fibers by the air-through method, the gas spraying pressure, the spraying speed, the basis weight and thickness of the fiber layer, the transport speed of the fiber layer, and the like may be appropriately adjusted. By simply adopting the conditions for producing a normal air-through nonwoven fabric, the constituent fibers of the inelastic fiber layer and the constituent fibers of the elastic fiber layer cannot be entangled. As will be described later in the production method, the desired stretchable nonwoven fabric in the stretchable laminated sheet of the present invention is obtained by performing the air-through method under specific conditions.

  In the air-through method, generally, a gas heated to a predetermined temperature is penetrated in the thickness direction of the fiber layer. In that case, fiber entanglement and fiber intersection fusion occur simultaneously. However, in the stretchable nonwoven fabric 2 in the present invention, it is not essential to fuse the fiber intersections between the constituent fibers in each layer by the air-through method. In other words, in the air-through method, the constituent fiber of the non-elastic fiber layer is allowed to enter the elastic fiber layer, or the constituent fiber of the non-elastic fiber layer is entangled with the constituent fiber of the elastic fiber layer, and the non-elastic fiber This operation is necessary for heat-sealing the constituent fibers of the layer and the constituent fibers of the elastic fiber layer. The direction in which the fibers enter varies depending on the passing direction of the heated gas and the positional relationship between the inelastic fiber layer and the elastic fiber layer. The inelastic fiber layer is preferably an air-through nonwoven fabric in which constituent fibers are fused at fiber intersections by an air-through method.

  As is apparent from the above description, in the preferred form of the stretchable nonwoven fabric 2 in the first embodiment, the elastic fibers in a state in which the constituent fibers maintain the fiber form inside the substantially inelastic air-through nonwoven fabric in the thickness direction. A layer is included, and a part of the constituent fibers of the air-through nonwoven fabric enters the elastic fiber layer and / or a part of the constituent fibers of the elastic fiber layer enters the non-elastic fiber layer. Yes.

  In a more preferred embodiment, some of the constituent fibers of the air-through nonwoven fabric are entangled only with the constituent fibers of the elastic fiber layer by the air-through method. Since the elastic fiber layer is included in the air-through nonwoven fabric, the constituent fibers of the elastic fiber layer are substantially not present on the surface of the stretchable nonwoven fabric. This is preferable from the point that the stickiness peculiar to an elastic fiber does not arise.

  The elastic fiber layer 21 has a property that it can be stretched and contracts when released from the stretched force. The elastic fiber layer 21 preferably has a residual strain of 20% or less, particularly 10% or less when contracted after 100% elongation in at least one direction parallel to the surface. This value is preferably satisfied in at least one of the MD direction and the CD direction, and more preferably satisfied in both directions.

  The elastic fiber layer 21 is an aggregate in which elastic fibers are gathered in layers. However, as long as the elastic elasticity of the elastic fiber layer 21 is not impaired, a small amount of inelastic fibers may be included. The fiber having elasticity may be a continuous fiber or a short fiber. Examples of a method for forming an elastic fiber include a melt blown method in which a molten resin is extruded from a nozzle hole, and the extruded molten resin is elongated with hot air to thin the fiber, or a semi-molten resin is cooled with cold air. There is also a spunbond method in which stretching is performed by a mechanical draw ratio. There is also a spinning blow method which is a kind of melt spinning method.

  The elastic fiber layer 21 may be in the form of a web or a nonwoven fabric made of elastic fibers. For example, it may be a web or a non-woven fabric formed by a spinning blow method, a spun bond method, a melt blow method, or the like. A particularly preferable elastic fiber layer 21 is a web obtained by a spinning blow method.

  A spinning die is used in the spinning blow method. The spinning die has a pair of hot air discharge portions opposed to each other in the vicinity of the tip of the molten polymer discharge nozzle with the discharge nozzle as a center, and a pair of cold air discharge portions opposed to each other downstream thereof. The spinning blown method has an advantage that the stretchable fiber can be easily formed because the melted fiber is continuously stretched by hot air and cold stretched by cold air. Further, since the fibers do not become too dense and elastic fibers having a thickness similar to short fibers can be formed, there is an advantage that a nonwoven fabric with high air permeability can be obtained. Further, according to the spinning blow method, a continuous filament web can be obtained. Continuous filament webs are less susceptible to breakage at high elongation than short fiber webs, and tend to exhibit elasticity.

  Examples of spinning dies used in the spinning blow method include those described in FIG. 1 of JP-B 43-30017, those shown in FIG. 2 of JP-A 62-90361, and JP-A 3-3. The one described in FIG. 2 of JP-A-1717408 can be used. Furthermore, what is shown by FIG. 2 of Unexamined-Japanese-Patent No. 3-174008, and what is shown by FIG. 1 thru | or FIG. 3 of patent 3335949 can be used. The fibers spun from the spinning die are deposited on a collection net conveyor.

  As a constituent fiber of the elastic fiber layer 21, for example, a fiber made of a thermoplastic elastomer, rubber or the like can be used. In particular, fibers made from thermoplastic elastomers can be melt-spun using an extruder in the same way as ordinary thermoplastic resins, and the fibers thus obtained are easy to heat-seal. It is suitable for the stretchable nonwoven fabric 2 in the first embodiment having a nonwoven fabric as a basic configuration.

  Examples of the thermoplastic elastomer include styrene elastomers such as SBS, SIS, SEBS, and SEPS, olefin elastomers, polyester elastomers, and polyurethane elastomers. These can be used individually by 1 type or in combination of 2 or more types. Core-sheath type or side-by-side type composite fibers made of these resins can also be used. In particular, it is preferable to use a styrene-based elastomer, an olefin-based elastomer, or a combination thereof in terms of moldability, elastic properties, and cost of the elastic fiber.

  The inelastic fiber layers 22 and 23 have extensibility, but are substantially inelastic. The extensibility here refers to the case where the constituent fibers themselves are stretched, and even if the constituent fibers themselves are not stretched, the two fibers that have been heat-sealed at the intersection of the fibers are separated from each other, or the fibers are thermally fused. In some cases, the three-dimensional structure formed by a plurality of fibers is structurally changed due to wearing or the constituent fibers are broken, and the entire fiber layer is elongated.

  Examples of the fibers constituting the inelastic fiber layers 22 and 23 include fibers made of polyethylene (PE), polypropylene (PP), polyester (PET or PBT), polyamide, and the like. The fibers constituting the inelastic fiber layers 22 and 23 may be short fibers or long fibers, and may be hydrophilic or water repellent. Further, core-sheath type or side-by-side composite fibers, split fibers, irregularly shaped cross-section fibers, crimped fibers, heat-shrinkable fibers, and the like can also be used. These fibers can be used singly or in combination of two or more.

  The inelastic fiber layers 22 and 23 may be continuous filaments, short fiber webs or non-woven fabrics. In particular, a short fiber web is preferable because thick and bulky inelastic fiber layers 22 and 23 can be formed. The two inelastic fiber layers 22 and 23 may be the same or different with respect to the material, basis weight, thickness, and the like of the constituent fibers. In the case of the core-sheath type composite fiber, it is preferable that the core is PET or PP and the sheath is low melting point PET, PP or PE. In particular, these composite fibers are preferable in that heat fusion with the constituent fibers of the elastic fiber layer preferably including styrene-based elastomer, olefin-based elastomer and the like becomes strong and layer peeling hardly occurs.

  At least one of the two non-elastic fiber layers 22 and 23 is preferably 1.2 to 20 times, particularly 1.5 to 5 times as thick as the elastic fiber layer 21. On the other hand, the basis weight of the elastic fiber layer 21 is preferably higher than the basis weight of at least one of the two inelastic fiber layers 22 and 23. In other words, the non-elastic fiber layers 22 and 23 are preferably thicker than the elastic fiber layer 21 and have a smaller basis weight. When the thickness and the basis weight are in such a relationship, the non-elastic fiber layers 22 and 23 become thicker and bulkier than the elastic fiber layer 21. As a result, the stretchable nonwoven fabric 2 is soft and has a good texture.

  The inelastic fiber layers 22 and 23 preferably have a thickness of 0.05 to 5 mm, particularly 0.1 to 1 mm. On the other hand, the thickness of the elastic fiber layer 21 is preferably smaller than the thickness of the non-elastic fiber layers 22 and 23, specifically 0.01 to 2 mm, particularly preferably 0.1 to 0.5 mm. The thickness can be obtained as an average value of the thicknesses of the three visual fields by observing the cross section of the stretchable nonwoven fabric with a microscope at a magnification of 50 to 200 times, obtaining an average thickness in each visual field.

The basis weight of the non-elastic fiber layers 22 and 23 is preferably ¹ to 60 g / m ² , particularly 5 to 15 g / m ² , from the viewpoint of uniformly covering the surface of the elastic fiber layer 21 and the viewpoint of residual strain. . On the other hand, the basis weight of the elastic fiber layer 21 is preferably larger than the basis weight of the non-elastic fiber layers 22 and 23 from the viewpoints of stretchability and residual strain. It is preferred particularly 5 to 80 g / m ^2, in particular 20 to 40 g / m ^2.

  The fiber diameter of the constituent fibers of the elastic fiber layer 21 is preferably 1.2 to 5 times, particularly 1.2 to 2.5 times the fiber diameter of the constituent fibers of at least one of the inelastic fiber layers 22 and 23. . In addition to this, the fiber diameter of the constituent fibers of the elastic fiber layer 21 is preferably 5 μm or more, particularly 10 μm or more, and preferably 100 μm or less, particularly 40 μm or less, from the viewpoint of air permeability and stretchability.

  On the other hand, the fiber diameters of the constituent fibers of the inelastic fiber layers 22 and 23 are preferably 1 to 30 μm, particularly 10 to 20 μm. That is, as the constituent fibers of the non-elastic fiber layers 22 and 23, it is preferable to use those that are thinner than the constituent fibers of the elastic fiber layer 21. Thereby, the fusion point of the constituent fibers of the non-elastic fiber layers 22 and 23 located on the surface layer of the stretchable nonwoven fabric 2 is increased. The increase in the fusion point is effective in preventing the occurrence of fuzz in the stretchable nonwoven fabric 2. Furthermore, the stretchable nonwoven fabric 2 having a good touch can be obtained by using thin fibers.

  The elastic nonwoven fabric 2 in the first embodiment may be embossed. Embossing is performed for the purpose of further increasing the bonding strength between the elastic fiber layer 21 and the non-elastic fiber layers 22 and 23. Therefore, if the elastic fiber layer 21 and the non-elastic fiber layers 22 and 23 can be sufficiently bonded by the air-through method, there is no need to perform embossing. In the embossing process, the constituent fibers are joined to each other, but unlike the air-through method, the constituent fibers are not entangled.

  The stretchable nonwoven fabric 2 in the first embodiment has stretchability in at least one direction in the in-plane direction. It may have elasticity in all directions in the plane. In that case, the degree of stretchability may differ depending on the direction. The degree of stretchability in the most stretchable direction is preferably such that the load at 100% elongation is 20 to 500 cN / 25 mm, particularly 40 to 150 cN / 25 mm. Further, the residual strain when contracted from the 100% stretched state is preferably 15% or less, particularly preferably 10% or less.

The basis weight and thickness of the stretchable nonwoven fabric can be appropriately adjusted according to the specific application. For example, when used as a constituent material of an absorbent article, it is desirable that the basis weight is about ²⁰ to 160 g / m ² and the thickness is about 0.1 to 5 mm. The stretchable nonwoven fabric according to the present invention is flexible and has high air permeability due to the fact that the constituent fibers of the elastic fiber layer maintain the fiber form. Regarding the bending rigidity, which is a measure of flexibility, the bending rigidity value of the stretchable nonwoven fabric is preferably as low as 10 g / 30 mm or less. The air permeability is preferably 16 m / (kPa · s) or more. The elongation is preferably 100% or more.

  The bending stiffness is measured in accordance with JIS L-1096, and is obtained as an average value when bent in the flow direction and in a direction perpendicular to the flow direction, respectively, under the condition that the pushing amount by the handle ohmmeter is 8 mm and the slit width is 10 mm. It is done. The air permeability is determined by measuring the airflow resistance by AUTOMATIC AIR-PERMEABILITY TESTER KES-F8-AP1 manufactured by Kato Tech Co., Ltd. and obtaining the reciprocal thereof.

Next, the moisture permeable film 3 will be described. As the moisture permeable film, for example, a film obtained by melting and kneading a thermoplastic resin and a resin composition containing an inorganic filler that is not compatible with the thermoplastic resin is stretched to a predetermined magnification to form a porous hole having fine holes. A functional film. In order to impart sufficient moisture permeability to the moisture permeable film, the balance between the basis weight of the film and the blending amount of the inorganic filler may be set appropriately.
In order to achieve both high moisture permeability and resistance to tearing, the basis weight of the film is preferably 5 to 100 g / m ² , more preferably 10 to 50 g / m ² . Moreover, the compounding amount of the inorganic filler is preferably 20 to 80% by weight, more preferably 40 to 70% by weight as the weight% of the filler with respect to the weight of the entire film.

  As the inorganic filler contained in the moisture permeable film, for example, calcium carbonate, barium sulfate, zinc oxide, talc, zeolite, carbon, silica, silicate mineral and the like are used. On the other hand, as the thermoplastic resin constituting the moisture permeable film, for example, a polyolefin resin such as polyethylene or polypropylene is used.

  The moisture permeable film 3 is entirely bonded to the first inelastic fiber layer 22 in the stretchable nonwoven fabric 2. For this joining, for example, a hot-melt adhesive is used. If the moisture-permeable film 3 and the first inelastic fiber layer 22 are substantially bonded to each other so that there is no unbonded portion when viewed macroscopically, it is assumed that they are fully bonded.

In the stretchable laminated sheet 1 of the first embodiment, the first recess 41 is formed such that the outer surface of the moisture permeable film 3 is bent and recessed with respect to the base surface 11, and the second recess 42 is The outer surface of the second inelastic fiber layer 23 is formed so as to be smoothly recessed with respect to the base surface 12.
Regarding the first recess 41, “the outer surface of the moisture permeable film 3 is bent and recessed with respect to the base surface 11” means that when the moisture permeable film 3 is bent, due to its physical properties, the bent It means that the outer surface of the moisture permeable film 3 is bent and recessed with respect to the base surface 11 of the stretchable laminated sheet 1 based on the fact that the line appears relatively clearly.
In addition, regarding the second concave strip 42, “the outer surface of the second inelastic fiber layer 23 is smoothly recessed with respect to the base surface 12” means that even if the second inelastic fiber layer 23 is bent, It means that the outer surface of the second inelastic fiber layer 23 is smoothly recessed with respect to the base surface 12 of the stretchable laminated sheet 1 based on the fact that the bending line does not appear clearly due to its physical properties. To do.

  According to the stretchable laminated sheet 1 of the first embodiment, the moisture-permeable film 3 is not easily broken even if the stretch is repeated. The mechanism is not clear, but is considered as follows. Since the moisture permeable film 3 is bonded to the first inelastic fiber layer 22 entirely and is not left over, stress concentration is unlikely to occur and tearing is unlikely to occur. In addition, since the moisture permeable film 3 and the elastic fiber layer 21 are integrally formed with the first non-elastic fiber layer 22 interposed, the first non-elastic fiber layer 22 functions as a cushioning material. The load applied to the moisture permeable film 3 is buffered.

The uneven shape of the stretchable laminated sheet 1 is obtained by bending the moisture permeable film 3, so that the resistance of the moisture permeable film 3 is small at the time of contraction, and the stretchable nonwoven sheet and the moisture permeable film are simply laminated. Stretch responsiveness is better than stretchable laminated sheets.
Further, at the time of stretching, since the bending can be easily deformed so that the concavo-convex shape of the stretchable laminated sheet 1 becomes flat, there is little stretch resistance feeling as can be seen with a simply laminated stretchable laminate sheet.

Since the stretchable laminated sheet 1 tries to restore a shape having irregularities by shrinkage after stretching, the same effect can be continued even in repeated stretching.
Moreover, since the 2nd inelastic fiber layer 23 has smooth uneven | corrugated shape, a soft and favorable touch is obtained. In particular, at the time of contraction, since there is also a cushioning property due to unevenness, a more flexible stretchable laminated sheet that exhibits a synergistic effect due to a softer cushion feeling can be obtained.

The stretchable laminated sheet of the present invention can be used by, for example, partially joining a portion requiring moisture permeability and stretchability in a disposable diaper. Moreover, intensity | strength can be partially improved about a disposable diaper. In these cases, some of the stretchable laminated sheets can be overlapped and joined to the disposable diaper.
In addition, the stretchable laminated sheet of the present invention can be used in the same manner in sanitary napkins, urinary incontinence pads, etc., and in that case, it improves the fit and softness when worn and presents a high-class feeling. Can do.
In addition, it can be used for a sheet such as a warmer or a steam thermal sheet that is directly attached to the human body, and in that case, the stretchability and moisture permeability can be provided once, so that the feeling of stuffiness can be improved, Since it can follow according to a motion of a body, a feeling of fit and a feeling of adhesion can be improved.

Next, the manufacturing method of the stretchable laminated sheet of the present invention will be described based on the preferred embodiments with reference to the drawings. The method for producing the stretchable laminated sheet of the first embodiment is a method for producing the stretchable laminated sheet 1 of the first embodiment described above.
Hereinafter, the manufacturing method of the stretchable laminated sheet of the first embodiment will be described in detail.
As shown in FIG. 2, a non-elastic short fiber is used as a raw material, and a first non-elastic fiber web 22 ′ is manufactured by a card machine 51 and continuously conveyed in one direction.

Further, the fibers spun by the spinning blown spinning die 52 using an elastic resin as a raw material are deposited on a collection net conveyor to produce an elastic fiber web 21 ′ containing continuous filaments of elastic fibers. This is peeled off from the conveyor and laminated on the inelastic fiber web 22 'which is continuously conveyed in one direction.
Further, a second non-elastic fiber web 23 ′ manufactured by the card machine 53 is laminated on the elastic fiber web 21 ′.

Here, after the non-elastic fiber web 22 'is temporarily fused by heat treatment or after temporary entanglement, it is preferable to directly deposit elastic fibers spun directly thereon. By doing in this way, the freedom degree of an elastic fiber becomes high and it becomes easy to make a mutual fiber enter by wind etc. further.
Examples of temporary fusing by heat treatment include a heat roll method, a pressure calender roll method, a steam method, and an air-through method, and examples of temporary confounding include a needle punch method and a water jet method. In particular, use of a heat roll and an air-through method is preferable in that the texture of the nonwoven fabric is not impaired and the facility space can be reduced.

  The non-elastic fiber web 22 'is preferably not directly wound after the temporary fusion or temporary entanglement, and the elastic fibers are directly deposited thereon in-line. Once wound, the inelastic fiber web 22 'may be crushed by the winding pressure. The purpose of temporary fusing or entanglement is to prevent the non-elastic fiber web 22 'from being blown away by wind or the like when the elastic fibers are directly melt-spun and deposited on the non-elastic fiber web 22'.

  The laminate of the three webs 23 ′, 21 ′ and 22 ′ is sent to an air-through dryer 54 where hot air treatment is performed. By the hot air treatment, a part of the constituent fibers of the non-elastic fiber web 23 ′ located mainly on the hot air blowing surface side enters the elastic fiber web 21 ′. Depending on the conditions of the hot air treatment, some of the constituent fibers of the non-elastic fiber web 23 ′ enter the elastic fiber web 21 ′, and further entangle with the constituent fibers of the elastic fiber web 21 ′. Alternatively, some of the constituent fibers of the non-elastic fiber web 23 ′ penetrate the elastic fiber web 21 ′, reach the non-elastic fiber web 22 ′, and are entangled with the constituent fibers of the non-elastic fiber web 23 ′.

  Preferably, part of the constituent fibers of the non-elastic fiber web 23 'is allowed to enter the elastic fiber web 21' and / or part of the constituent fibers of the elastic fiber web 21 'are allowed to enter the non-elastic fiber web 23'. The conditions are: hot air flow rate: 0.4-3 m / second, temperature: 80-160 ° C., conveyance speed: 5-200 m / minute, hot air treatment time: 0.5-10 seconds. In particular, the hot air flow rate is preferably higher than the hot air flow rate that is generally performed as an air-through method, and is particularly preferably 1 to 2 m / sec.

  If a high air permeability net is used for the hot-air treatment of the air-through method, the fibers are more likely to enter depending on the passage of air. Similarly, when the elastic fiber web 21 ′ is directly spun on the non-elastic fiber web 22 ′, the constituent fibers of the elastic fiber web 21 ′ can easily enter the non-elastic fiber web 22 ′ by the wind during spinning.

The air permeability of the net used for the hot air treatment and the net used for the direct spinning of the elastic fiber is preferably 250 to 800 cm ³ / (cm ² · s), particularly 400 to 750 cm ³ / (cm ² · s). The above conditions are also preferable in terms of softening the fibers and allowing them to penetrate uniformly and fusing the fibers. Furthermore, the entanglement of the fibers can be achieved by setting the hot air flow rate to 3 to 5 m / sec and the spraying pressure to 0.1 to 0.3 kPa.
It is preferable that the air permeability of the elastic fiber web 21 ′ is 8 m / (kPa · s) or more, particularly 24 m / (kPa · s) or more, because the hot air can flow better and the fibers can enter more uniformly. . Further, the fiber fusion is good and the maximum strength is high. In addition, fuzz is prevented.

  In the hot air treatment, a part of the constituent fibers of the non-elastic fiber web 23 ′ enters the elastic fiber web 21 ′ and at the same time, the constituent fibers of the non-elastic fiber web 23 ′ and / or the configuration of the non-elastic fiber web 22 ′. The fibers and the constituent fibers of the elastic fiber web 21 'are heat-sealed at their intersections. In this case, care should be taken so that the constituent fibers of the elastic fiber web 21 'do not become a film or film-fiber structure by the hot air treatment. In the hot air treatment, the constituent fibers of the inelastic fiber web 23 'are heat-sealed at the intersection, and similarly, the constituent fibers of the elastic fiber web 21' and the constituent fibers of the inelastic fiber web 22 'are intersected. Heat fusion.

  An unembossed fiber sheet 2 ″ in which the three webs 23 ′, 21 ′ and 22 ′ are integrated is obtained by the hot air treatment of the air-through method. The unembossed fiber sheet 2 ″ has regular embossed convex portions on the peripheral surface. Is sent to an embossing device 55 having an embossing roll 56 and a receiving roll 57 arranged opposite to each other, where hot embossing is performed. By hot embossing, an embossed fiber sheet 2 'in which joints (not shown) are formed in a regular pattern is obtained. The joint is preferably formed discontinuously in both the flow direction (MD) of the embossed fiber sheet 2 ′ and its orthogonal direction (CD).

Next, an adhesive is applied to the entire outer surface of the first inelastic fiber web 22 ′ in the embossed fiber sheet 2 ′ by the coating device 71. For example, a hot-melt adhesive is used as the adhesive. The adhesive is continuous as viewed macroscopically and may be applied substantially entirely so that there is no uncoated portion.
Examples of the coating apparatus that can apply the adhesive on the entire surface include a contact method such as a roll coater method and a screen printing method, and a non-contact method such as a spray method. By applying the adhesive continuously with these coating apparatuses, a substantially entire adhesion region can be obtained. The coating amount of the adhesive is preferably 0.5 to 20 g / m ² , more preferably 1 to 10 g / m ² .

  And as shown in FIG.2 and FIG.3, continuous body 3 'of the moisture-permeable film 3 is formed in the outer surface of 1st inelastic fiber web 22' to which the adhesive agent was coated in the to-be-embossed fiber sheet 2 '. Merge. The joined embossed fiber sheet 2 ′ and moisture permeable film continuous body 3 ′ are sandwiched between a pair of nip rolls 72, 72, and are joined together by the adhesive force of the adhesive to form a flat laminated sheet 1 ′. Form.

Here, the moisture permeable film 3 is configured to join the opposite side of the embossing roll 56 (that is, the receiving roll 57 side). The first non-elastic fiber web located on the opposite side of the embossing roll 56 is used. 22 'is because the influence of the unevenness due to the embossing is relatively small, it is easy to apply the adhesive without unevenness, and it is easy to integrally bond with the moisture permeable film 3.
The flat laminated sheet 1 ′ is laminated in four layers in the order of a moisture permeable film continuous body 3 ′, a first inelastic fiber web 22 ′, an elastic fiber web 21 ′, and a second inelastic fiber web 23 ′. Yes. This flat laminated sheet 1 ′ does not have a wavy shape, and therefore the first concave 41 and the second concave 42 are not formed.

  Next, the flat laminated sheet 1 ′ having a four-layer structure is stretched. Specifically, as shown in FIGS. 2 and 4, a large-diameter portion 61, 62 and a small-diameter portion (not shown) are provided with a pair of concavo-convex rolls 63, 64 formed alternately in the axial direction. Using the stretching device 6, the flat laminated sheet 1 ′ is stretched in a direction (CD) orthogonal to the flow direction (MD).

  The stretching device 6 has a known lifting mechanism (not shown) that vertically displaces the pivotal support portion of one or both of the concave and convex rolls 63 and 64, and the interval between the concave and convex rolls 63 and 64 can be adjusted. . In this manufacturing method, as shown in FIGS. 4 and 5, each of the uneven rolls 63 and 64 is allowed to play between the large diameter portion 61 of one uneven roll 63 and the large diameter portion 62 of the other uneven roll 64. It is inserted and combined so that the large diameter part 62 of the other uneven | corrugated roll 64 is loosely inserted between the large diameter parts 61 of one uneven | corrugated roll 63, Between the uneven | corrugated rolls 63 and 64 of the state, the flat laminated sheet 1 'Is inserted and the flat laminated sheet 1' is stretched.

  According to this manufacturing method, when flat laminated sheet 1 'passes between the uneven | corrugated rolls 63 and 64, the area | region between large diameter parts which do not overlap with the large diameter parts 61 and 62 is positively extended. . By this stretching, the non-elastic fiber layers 22 and 23 and the moisture permeable film 3 are changed so as not to recover even when the flat laminated sheet 1 ′ contracts. Due to the change, the degree to which the non-elastic fiber layers 22 and 23 and the moisture permeable film 3 hinder free expansion and contraction of the elastic fiber layer 21 is greatly reduced.

By the stretching process, the thickness of the flat laminated sheet 1 ′ is preferably increased 1.1 times to 4 times, particularly 1.3 times to 3 times before and after the stretching process. As a result, the fibers of the inelastic fiber layers 22 and 23 are plastically deformed to be elongated and thinned. At the same time, the non-elastic fiber layers 22 and 23 become more bulky and have a good texture and good cushioning properties.
If the thickness of the flat laminated sheet 1 ′ before being stretched is thin, there is an advantage that the space for transporting and storing the roll of the flat laminated sheet 1 ′ can be reduced.

  Furthermore, it is preferable that the bending rigidity of the flat laminated sheet 1 ′ is changed to 30 to 80%, particularly 40 to 70% as compared with that before the drawing process by the drawing process. Thereby, the stretchable laminated sheet 1 having good drape and softness can be obtained. Further, it is preferable that the flat laminated sheet 1 ′ before being stretched has a high bending rigidity, so that it is difficult for wrinkles to enter the flat laminated sheet 1 ′ in the transport line. In addition, the flat laminated sheet 1 ′ is not wrinkled even during the drawing process, which is preferable because it can be easily processed.

  The thickness and bending rigidity of the flat laminated sheet 1 ′ before and after the stretching process are the thickness and physical properties of the moisture permeable film 3, the elongation of the fibers used for the inelastic fiber layers 22 and 23, the pitch of the concave and convex rolls 63 and 64, It can be controlled by the thickness of the tip and the amount of meshing.

  The peripheral surfaces of the large-diameter portions 61 and 62 of the uneven rolls 63 and 64 are preferably not sharp so as not to damage the flat laminated sheet 1 ′, particularly the moisture permeable film continuous body 3 ′. For example, as shown in FIG. 5, a flat surface having a predetermined width is preferable. The width W (see FIG. 5, the width in the extending direction of the flat laminated sheet 1 ′) of the distal end portions of the large diameter portions 61 and 62 is preferably 0.3 to 1 mm.

  Further, in a state where the one uneven roll 63 and the other uneven roll 64 are engaged with each other, the pitch P between the large diameter portion 61 of the one uneven roll 63 and the large diameter portion 62 of the other uneven roll 64 (see FIG. 5). Is preferably 0.7 to 2.5 mm. As a result, the exposed second non-elastic fiber layer 23 has a cloth-like appearance, and the touch is improved.

The flat laminated sheet 1 ′ sent out from the stretching device 6 is released from the stretched state in the width direction. That is, the elongation is eased. As a result, elasticity is developed in the flat laminated sheet 1 ′, and the flat laminated sheet 1 ′ contracts in the width direction. Thereby, the intended stretchable laminated sheet 1 is obtained.
When the stretched state is released, the stretched state may be completely released, or the stretched state may be released in a state where the stretched state is maintained to some extent as long as stretchability is exhibited.

  As shown in FIG. 2, the stretchable laminated sheet 1 obtained by the production method of the first embodiment can be wound up into a roll shape once, or is directly put into a production line (not shown) such as a diaper. You can also

The mechanism by which the cross-sectional shape of the stretchable laminated sheet 1 of the first embodiment is formed by the manufacturing method of the first embodiment is considered as follows.
In the flat laminated sheet 1 ′, unstretched portions pressed by the large diameter portions 61 and 62 and stretched portions stretched without being pressed by the large diameter portions 61 and 62 are alternately arranged.
The width (length) of each of the stretched part and the unstretched part can be controlled in various states by changing the pitch of the large diameter part of the uneven roll.
Moreover, when the pitch of the large diameter part of an uneven | corrugated roll and the space | interval of the embossing pattern used when forming the stretchable laminated sheet 1 correspond periodically, it is an alternate arrangement of stretched parts and unstretched parts. The embossed part of the embossed pattern is synchronized with the base point. Therefore, also in appearance, the alternating arrangement of stretched parts and unstretched parts becomes clearer and can be processed into a sheet having a clean appearance.

According to the manufacturing method of the first embodiment, the stretchable laminated sheet 1 of the first embodiment can be easily manufactured while preventing the moisture permeable film 3 from being torn. Moreover, since the moisture permeable film 3 can be extended partially, the moisture permeability of the entire moisture permeable film 3 can be improved.
In addition, it is preferable to set beforehand the allowable range of the absolute value of the length of the moisture-permeable film 3 extended | stretched by extending | stretching, and an elongation rate.

Next, a second embodiment of the method for producing a stretchable laminated sheet of the present invention will be described with reference to FIGS. In the description of the second embodiment, the description of the first embodiment described above is appropriately applied to points that are not particularly described.
In the second embodiment, as compared with the first embodiment described above, the steps until the embossed fiber sheet 2 ′ corresponding to the stretchable nonwoven fabric 2 is formed and the subsequent steps are performed in different production lines. The point is mainly different.
Specifically, the manufacturing method of the second embodiment is the same as the manufacturing method of the first embodiment until the embossed fiber sheet 2 ′ is formed using the embossing device 55. Thus, in the manufacturing method of the second embodiment, the formed embossed fiber sheet 2 ′ is once formed into a roll.

Next, as shown in FIG. 7, in another production line, an adhesive is entirely applied to the first inelastic fiber web 22 ′ side (upper side in FIG. 7) by the coating device 71 in the fiber sheet 2 ′ to be embossed. Apply to. Then, the moisture permeable film continuous body 3 ′ is joined to the outer surface of the first inelastic fiber web 22 ′ to which the adhesive is applied in the embossed fiber sheet 2 ′. The joined embossed fiber sheet 2 ′ and moisture permeable film continuous body 3 ′ are sandwiched between a pair of nip rolls 72, 72, and are joined together by the adhesive force of the adhesive to form a flat laminated sheet 1 ′. Form.
Similar to the first embodiment, the flat laminated sheet 1 ′ is stretched by the stretching device 6 to obtain the stretchable laminated sheet 1.

Next, a third embodiment of the stretchable laminated sheet of the present invention will be described with reference to FIGS. In the description of the third embodiment, the description of the first embodiment and the second embodiment described above is appropriately applied to points that are not particularly described.
Compared with the manufacturing method of the first embodiment described above, the manufacturing method of the third embodiment includes a process until a flat laminated sheet 1 ′, which is a previous stage of the stretchable laminated sheet 1, and a flat laminated layer. The main difference is that the step of stretching the sheet 1 ′ to form the stretchable laminated sheet 1 is performed on a different production line.

Specifically, the manufacturing method of the third embodiment is the same as the manufacturing method of the first embodiment until the flat laminated sheet 1 ′ is formed using the pair of nip rolls 72, 72. Thus, in the manufacturing method of the third embodiment, the formed flat laminated sheet 1 ′ is once rolled.
Next, as shown in FIG. 9, in another production line such as a diaper, the flat laminated sheet 1 ′ is stretched by the stretching device 6 in the same manner as in the manufacturing method of the first embodiment, and stretched. The conductive laminated sheet 1 is obtained.

  In the manufacturing method of the first to third embodiments described above, the flat laminated sheet 1 ′ is stretched in the CD direction. In the manufacturing method of the stretchable laminated sheet of the present invention, As shown in FIGS. 10 and 11, there is no limitation, and stretching is provided with a pair of concave and convex rolls 63 and 64 in which large-diameter portions 61 ′ and 62 ′ and small-diameter portions (not shown) are alternately formed in the circumferential direction. Using the apparatus 6, the flat laminated sheet 1 'can be stretched in the flow direction (MD).

  Moreover, in the manufacturing method of the above-mentioned 1st-3rd embodiment, the to-be-embossed fiber sheet 2 'equivalent to the elastic nonwoven fabric 2 and moisture-permeable film continuous body 3' are joined, and flat laminated sheet 1 'is obtained. After the step of forming, the flat laminated sheet 1 ′ is stretched using the stretching apparatus 6. In the method for producing the stretchable laminated sheet of the present invention, the embossed fiber sheet 2 ′ and the moisture permeable film are used. The continuous body 3 ′ can be joined immediately before the stretching apparatus 6 to perform the stretching process of the flat laminated sheet 1 ′ simultaneously with the formation of the flat laminated sheet 1 ′ (not shown).

  Next, another embodiment of the stretchable laminated sheet of the present invention will be described. In the other embodiments, differences from the first embodiment described above will be mainly described, and the same points are denoted by the same reference numerals and description thereof will be omitted. For the points that are not particularly described, the description of the first embodiment is applied as appropriate. In other embodiments, the same effects as those of the first embodiment can be obtained.

  The stretchable laminated sheet of the second embodiment is arranged so that the elastic fiber aggregates 21 in the stretchable nonwoven fabric 2 extend in one direction without crossing each other as compared with the stretchable laminated sheet of the first embodiment. The main difference is that it is composed of a large number of elastic filaments 24 ". About 2nd Embodiment, the process of joining the structure of moisture-permeable film 3 itself, elastic nonwoven fabric 2 (embossed fiber sheet 2 '), and moisture-permeable film 3 (moisture-permeable film continuous body 3'), flat lamination Since the process of stretching the sheet 1 ′ and the like are the same as those in the first embodiment, the configuration of the stretchable nonwoven fabric 2 itself and the manufacturing method thereof will be mainly described below.

  The perspective view which fractured | ruptured one part about the elastic nonwoven fabric 2 in the elastic laminated sheet of 2nd Embodiment is shown by FIG. The stretchable nonwoven fabric 2 in the second embodiment includes a first inelastic fiber layer 22 and a second inelastic fiber layer 23, and a large number of elastic filaments 24 sandwiched between the inelastic fiber layers 22 and 23. It is configured. Each elastic filament 24 is joined to the first inelastic fiber layer 22 and the second inelastic fiber layer 23. The first inelastic fiber layer 22 and the second inelastic fiber layer 23 may be the same or different. The term “same type” as used herein means that the inelastic fiber layer manufacturing process, the types of constituent fibers of the inelastic fiber layer, the fiber diameter and length of the constituent fibers, the thickness and basis weight of the inelastic fiber layer, etc. are all the same. It means that there is. If at least one of these is different, it is said to be “different”.

  Each inelastic fiber layer 22, 23 has extensibility in the same direction as the direction in which the elastic filament 24 extends. “Having extensibility” means that (a) the constituent fibers of the inelastic fiber layers 22 and 23 are stretched, and (b) the constituent fibers themselves are not stretched but bonded at the intersection. The three-dimensional structure formed by a plurality of fibers may be structurally changed due to separation of the fibers, the fibers may be broken, etc., and the non-elastic fiber layer may be stretched as a whole. is there.

  Each of the non-elastic fiber layers 22 and 23 may be already stretchable in the state of the original fabric before being joined to the elastic filament 24. Alternatively, it may not be stretchable in the original fabric state before being joined to the elastic filament 24, but may be made stretchable by being processed so as to be stretchable after being joined to the elastic filament 24. Specific methods for enabling the non-elastic fiber layers 22 and 23 to be stretched include heat treatment, inter-roll stretching, biting stretching using tooth spaces and gears, and tensile stretching using a tenter. The non-elastic fiber layers 22 and 23 are stretched in the state of the original fabric because the transportability of the non-elastic fiber layers 22 and 23 when the elastic filament 24 is fused to the non-elastic fiber layers 22 and 23 is improved. Preferably it is not possible.

  Each inelastic fiber layer 22, 23 is extensible and substantially inelastic. Elasticity is a property that can be stretched and contracts when released from the stretched force, and each of the inelastic fiber layers 22 and 23 does not have such a property. If each of the non-elastic fiber layers 22 and 23 has elasticity, a fiber containing an elastic resin is required as its constituent fiber, and the fiber containing the elastic resin is a cause of reducing the texture of the non-elastic fiber layers 22 and 23. It tends to exhibit a sticky feeling. Accordingly, the inelastic fiber layers 22 and 23 are made substantially inelastic to prevent the texture from being lowered.

  Each elastic filament 24 is substantially continuous over the entire length of the stretchable nonwoven fabric 2. The elastic filament 24 contains an elastic resin. The elastic filaments 24 are arranged so as to extend in one direction without crossing each other. However, the elastic filaments 24 are allowed to cross unintentionally due to inevitable fluctuations in the production conditions of the stretchable nonwoven fabric 2. Each elastic filament 24 may extend linearly as long as it does not cross each other, or may extend while meandering. The direction in which the elastic filament 24 extends may coincide with the flow direction when the non-elastic fiber layers 22 and 23 are manufactured, or may be orthogonal to the flow direction when the non-elastic fiber layers 22 and 23 are manufactured. . When the stretchable nonwoven fabric 2 is manufactured according to a suitable manufacturing method described later, the extending direction of the elastic filament 24 coincides with the flow direction at the time of manufacturing the first inelastic fiber layer 22 and the second inelastic fiber layer 23.

  The elastic filament 24 is bonded to the non-elastic fiber layers 22 and 23 in a substantially non-stretched state. Since the elastic filaments 24 are not elongated, relaxation (creep) does not occur due to elongation, and after the elastic filament 24 is bonded to the non-elastic fiber layers 22 and 23, the raw fabric is stored or after processing such as stretching. There is an advantage that there is no decrease in stretchability. Further, there is no deformation due to the tightness of the wound-up raw material. Furthermore, for example, when the elastic filament 24 is stretched twice and bonded to the non-elastic fiber layers 22 and 23, if it returns to 1.3 times the initial value, it is only 1.7 times from this state. Although it cannot be stretched, when pasted together in a non-stretched state, the initial origin when the stretchable nonwoven fabric is stretched is different, so the stretchable length of the non-elastic fiber layers 22 and 23 or elastic filament There is an advantage that it is possible to extend to a maximum elongation of 24.

  The elastic filament 24 can be a thread-like synthetic rubber thread or natural rubber. Alternatively, it may be obtained by dry spinning (melt spinning) or wet spinning. Among these, in view of a preferable manufacturing method to be described later, the elastic filament 24 is preferably obtained by direct melt spinning without winding it once.

  The elastic filament 24 is preferably obtained by drawing an undrawn yarn. By stretching, the polymer constituting the elastic filament 24 is molecularly oriented in the length direction of the elastic filament 24, so that the going / returning ratio at the time of 50% elongation, which will be described later, is increased and the hysteresis loss is reduced. Moreover, the thin elastic filament 24 is obtained by extending | stretching. From this point of view, the elastic filament 24 is preferably stretched 1.1 to 400 times, particularly 4 to 100 times.

In particular, the elastic filament 24 is preferably formed by being stretched in a state where the elastic resin is melted or softened. By stretching the elastic resin in a melted or softened state, the elastic filament 24 can be bonded to the non-elastic fiber layers 22 and 23 in a non-stretched state.
As specific operations for drawing, (a) a resin as a raw material for the elastic filament 24 is melt-spun to obtain an undrawn yarn once, and the elastic filament 24 of the undrawn yarn is heated again to a softening temperature (hard Examples include an operation of stretching in a state of the glass transition temperature Tg) of the segment or more, and (b) an operation of directly stretching a molten fiber obtained by melt spinning a resin that is a raw material of the elastic filament 24. When the stretchable nonwoven fabric 2 is manufactured according to a suitable manufacturing method described later, the elastic filament 24 is obtained by directly stretching a melted fiber obtained by melt spinning.

  The elastic filament 24 obtained by stretching preferably has a diameter of 10 to 200 μm, particularly 20 to 130 μm. This range is determined in consideration of the texture of the stretchable nonwoven fabric 2 and the productivity of the elastic filament 24. Specifically, if the diameter of the elastic filament 24 is too large, a step due to the elastic filament 24 is easily perceived when the elastic nonwoven fabric 2 is touched. This step acts negatively on the texture of the stretchable nonwoven fabric 2. From this viewpoint, the smaller the diameter of the elastic filament 24, the better because only the texture of each of the non-elastic fiber layers 22 and 23 is easily perceived. Further, the elastic filament 24 is preferably thin in order to conceal the stretchable nonwoven fabric 2.

  Further, in the stretching by the dentition roll, the diameter of the elastic filament 24 is equal to or less than the clearance between the teeth between the dentition rolls (preferred clearance is to increase the endurance of the teeth and increase the draw ratio by the amount of biting In view of this, the elastic filament is less likely to be damaged (cracked or cut) at the time of stretching. The ratio between the diameter of the elastic filament and the clearance is preferably 0.2 to 1, particularly 0.2 to 0.5. However, the smaller the diameter of the elastic filament 24, the easier it is to manufacture. Considering these, the diameter of the elastic filament 24 is preferably within the above-mentioned range.

  From the viewpoint of preventing the above step from being generated, the ratio of the diameter of the elastic filament 24 (in the thickness direction of the stretchable nonwoven fabric) to the thickness of the stretchable nonwoven fabric 2 is 1 to 30%, particularly 5 to 12%. Is preferred.

  The elastic filament 24 may have a circular cross section, but in some cases may have an elliptical cross section. For example, when the stretchable nonwoven fabric 2 is manufactured according to the manufacturing method described later, the cross section of the elastic filament 24 tends to be elliptical. In this case, in the elastic nonwoven fabric 2, the elastic filament 24 has an elliptical long axis in the same direction as the plane direction of the elastic nonwoven fabric 2 and a short axis in the same direction as the thickness direction of the elastic nonwoven fabric 2. It is preferable to arrange so as to be.

  When the cross section of the elastic filament 24 is elliptical, the ratio of the major axis / minor axis (average flatness) is the stretch property, the bonding strength between the elastic filament 24 and the non-elastic fiber layers 22 and 23, and the stretch. From the point which the concealability of the non-woven fabric 2 increases, it is preferably 1.0 to 7.0, particularly 1.1 to 3.0. The elastic filaments 24 having an elliptical cross section are arranged so that the major axis direction thereof substantially coincides with the planar direction of the stretchable nonwoven fabric 2. In addition, when the cross section of the elastic filament 24 is elliptical, the diameter of the elastic filament 24 means what averaged the major axis diameter and the minor axis diameter.

  The elastic filament 24 is also preferably colored in a color different from the color of the second inelastic fiber layer 23. Thereby, the elastic filament 24 can be seen through the second inelastic fiber layer 23, and the design effect that the stretchable nonwoven fabric 2 comes to exhibit a striped pattern is exhibited. Such an effect becomes more remarkable particularly when the thickness and basis weight of the non-elastic fiber layer 23 are within the ranges described below.

  From the viewpoint of the stretchable nonwoven fabric 2 exhibiting sufficient stretchability, the viewpoint of expressing a good cloth-like texture, and the viewpoint of expressing the above-described design effect as necessary, the pitch of the adjacent elastic filaments 24 is: On the condition that the diameter of the elastic filament 24 is in the above-mentioned range, it is preferably 0.1 to 5 mm, particularly preferably 0.4 to 1 mm.

  The elastic filament 24 is joined to each inelastic fiber layer 22 and 23 over its entire length. Here, “bonded over the entire length” means that all the fibers in contact with the elastic filament 24 (component fibers of the non-elastic fiber layers 22 and 23) are bonded to the elastic filament 24. The elastic filament 24 and the constituent fibers of the non-elastic fiber layers 22 and 23 are bonded to each other in such a manner that the intentionally formed non-bonded portion does not exist in the elastic filament 24. Say. Since the elastic filament 24 is bonded to the inelastic fiber layers 22 and 23 over the entire length, the bonding force between the elastic filament 24 and the inelastic fiber layers 22 and 23 can be sufficiently increased. As a result, even if the stretchable nonwoven fabric 2 is stretched, the elastic filament 24 is difficult to peel off from the inelastic fiber layers 22 and 23. When the elastic filament 24 is peeled off from each of the non-elastic fiber layers 22 and 23, floating occurs between the elastic filament 24 and each of the non-elastic fiber layers 22 and 23 in a natural state (relaxed state), and the elasticity is increased. Wrinkles are likely to occur in the nonwoven fabric 2, and the stretchable nonwoven fabric 2 as a whole lacks a sense of unity.

  Examples of the manner of joining the elastic filament 24 and the non-elastic fiber layers 22 and 23 include fusion and adhesion with an adhesive. When the stretchable nonwoven fabric 2 is manufactured according to a suitable manufacturing method to be described later, the elastic filaments 24 are bonded to the inelastic fiber layers 22 and 23 by fusion. According to this method, heat is not applied to the inelastic fiber layers 22 and 23, and the elastic filaments 24 are fused to the inelastic fiber layers 22 and 23 before the elastic filaments 24 obtained by melt spinning are solidified. . Accordingly, only the fibers existing around the elastic filament 24 are bonded to the elastic filament 24, and the fibers located further away from the elastic filament 24 maintain the texture of the non-elastic fiber layers 22 and 23. Therefore, there exists an advantage that the texture of the elastic nonwoven fabric 2 is maintained favorable. In this case, before the non-elastic fiber layers 22 and 23 and the elastic filaments 24 are bonded, an adhesive can be applied as an auxiliary bonding means. Alternatively, after joining the inelastic fiber layers 22 and 23 and the elastic filament 24, heat treatment (steam jet, heat embossing), mechanical entanglement (needle punch, spunlace), or the like is performed as an auxiliary joining means. You can also However, these auxiliary joining means may damage the texture of the resulting stretchable nonwoven fabric 2 or damage the elastic filament 24. Therefore, it is preferable to fuse the elastic filament 24 to the non-elastic fiber layers 22 and 23 with the heat of fusion. However, when a heat treatment comprising hot air blowing by an air-through method is used as an auxiliary joining means, the texture of the resulting stretchable nonwoven fabric 2 is not impaired, and the non-elastic fiber layers 22 and 23 have high joining strength. Is preferable in that it is obtained.

  The stretchable nonwoven fabric 2 can be stretched in the same direction as the direction in which the elastic filament 24 extends. The stretchability of the stretchable nonwoven fabric 2 is manifested due to the elasticity of the elastic filament 24. When the stretchable nonwoven fabric 2 is stretched in the same direction as the direction in which the elastic filament 24 extends, the elastic filament 24, the first inelastic fiber layer 22, and the second inelastic fiber layer 23 extend. When the stretch of the stretchable nonwoven fabric 2 is released, the elastic filament 24 contracts, and the first non-elastic fiber layer 22 and the second non-elastic fiber layer 23 return to the state before stretching as the contraction occurs.

  In the stretchable nonwoven fabric 2 in the second embodiment, there are no other elastic filaments bonded in a state orthogonal to the elastic filaments 24. Therefore, when the stretchable nonwoven fabric 2 is stretched in the same direction as the direction in which the elastic filament 24 extends, the stretchable nonwoven fabric 2 expands with little width shrinkage. That is, the stretchable nonwoven fabric 2 has a substantially uniform width along its longitudinal direction in the stretched state. As a result, the stretchability nonwoven fabric 2 is conveyed in the stretched state, and handling properties when processing this are improved. In addition, when the stretchable nonwoven fabric 2 is used as an outer packaging material of a pant-type diaper, for example, it is effectively prevented that a slippage occurs or wrinkles occur during wearing of the diaper. From this point of view, the stretchable nonwoven fabric 2 preferably has a width shrinkage ratio of 90% to 99%, particularly 95% to 99% of the width before stretching when stretched 1.5 times. The width reduction can be obtained as a value obtained by dividing the width after expansion by the width before expansion. The measurement of the width is performed by cutting a sample having a length of 1 m and a width of 300 mm, and stretching the sample by 1.5 times while keeping the distance between both ends to be stretched at a width of 300 mm. The measurement position of the width after extension is the center.

Next, constituent materials of the first non-elastic fiber layer 22, the second non-elastic fiber layer 23, and the elastic filament 24 that constitute the stretchable nonwoven fabric 2 in the second embodiment will be described.
Examples of the fibers constituting the inelastic fiber layers 22 and 23 include fibers made of polyethylene (PE), polypropylene (PP), polyester (PET or PBT), polyamide, and the like. The fibers constituting each of the inelastic fiber layers 22 and 23 may be short fibers or long fibers, and may be hydrophilic or water repellent. Further, core-sheath type or side-by-side composite fibers, split fibers, irregularly shaped cross-section fibers, crimped fibers, heat-shrinkable fibers, and the like can also be used. These fibers can be used singly or in combination of two or more. Each inelastic fiber layer 22, 23 may be a continuous filament or a short fiber nonwoven fabric. In particular, from the viewpoint of making the stretchable nonwoven fabric 2 thick and bulky, the inelastic fiber layers 22 and 23 are preferably short fiber nonwoven fabrics. When the stretchable nonwoven fabric 2 is used as a member that comes into contact with the skin, a short fiber nonwoven fabric with a good texture may be used on the skin contact side, and a high-strength continuous filament nonwoven fabric may be used on the opposite surface.

  Each inelastic fiber layer 22, 23 is preferably composed of two or more components of the low melting point component and the high melting point component. In that case, the constituent fibers are bonded to each other at the fiber intersection by heat fusion of at least the low melting point component. As the core-sheath type composite fiber composed of two or more components of a low melting point component and a high melting point component, those having a core of high melting point PET, PP and a sheath of low melting point PET, PP, PE are preferable. In particular, the use of these composite fibers is preferable because fusion with the elastic filament 24 becomes strong and peeling between the two hardly occurs.

  The constituent fibers of each of the inelastic fiber layers 22 and 23 are preferably of high elongation (for example, the maximum elongation of the fiber is 150 to 400%) in that a stretchable nonwoven fabric 2 having a high maximum strength can be obtained. . The elongation of the fiber is measured in accordance with JIS L-1015 under the conditions of measuring environment temperature and humidity: 20 ± 2 ° C., 65 ± 5% RH, tensile tester grip interval: 20 mm, tensile speed: 20 mm / min. . In addition, when the fibers are collected from the already produced inelastic fiber layers 22 and 23 and the elongation is measured, the gripping interval cannot be reduced to 20 mm, that is, the length of the measured fiber is less than 20 mm. In this case, the gripping interval is set to 10 mm or 5 mm and measured.

The thickness of each inelastic fiber layer 22, 23 is preferably 0.05 to 5 mm, more preferably 0.1 to 1.0 mm, and still more preferably 0.15 to 0.5 mm. Thickness is measured by sandwiching between flat plates with a load of 0.5 cN / cm ² , observing a cross section of the stretchable nonwoven fabric with a microscope at a magnification of 50 to 200 times, and obtaining an average thickness in each field of view. It can obtain | require as an average value of thickness. The thickness of the entire stretchable nonwoven fabric can be obtained by measuring the distance between the flat plates. The basis weight of each of the inelastic fiber layers 22 and 23 is preferably ³ to 100 g / m ² , particularly 10 to 30 g / m ² , from the viewpoints of texture, thickness, design properties, and the like.

  The elastic filament 24 is made of, for example, a thermoplastic elastomer or rubber. In particular, when a thermoplastic elastomer is used as a raw material, melt spinning using an extruder is possible in the same manner as a normal thermoplastic resin, and the filaments thus obtained are easily heat-sealed. It is suitable for the stretchable nonwoven fabric 2 in the second embodiment. Examples of the thermoplastic elastomer include styrene elastomers such as SBS (styrene-butadiene-styrene), SIS (styrene-isoprene-styrene), SEBS (styrene-ethylene-butadiene-styrene), SEPS (styrene-ethylene-propylene-styrene). And olefin-based elastomers (ethylene-based α-olefin elastomers, propylene-based elastomers copolymerized with ethylene / butene / octene), polyester-based elastomers, and polyurethane-based elastomers. These can be used individually by 1 type or in combination of 2 or more types. A core-sheath type or side-by-side type composite fiber made of these resins can also be used. In particular, it is preferable to use a styrene-based elastomer, an olefin-based elastomer, or a combination thereof in terms of moldability, elastic properties, and cost of the elastic filament 24.

  A suitable combination of the elastic filament 24 and the fibers constituting the inelastic fiber layers 22 and 23 uses SEBS resin or SEPS resin for the elastic filament 24, and PP / PE core sheath for the constituent fibers of the inelastic fiber layers 22 and 23. Type composite fiber or PET / PE core-sheath type composite fiber. By adopting this combination, fusion can be performed firmly. In addition, since the melting point of the core is high, the fiber is not completely melted at the time of fusion (the core remains), and the stretchable nonwoven fabric 2 having high maximum strength is obtained.

Moreover, although based also on a specific use, it is preferable that the whole basic weight of the elastic nonwoven fabric 2 in 2nd Embodiment is 10-150 g / m < ² >, especially 25-50 g / m < ² >. The thickness of the stretchable nonwoven fabric 2 is preferably 0.05 to 5 mm, particularly preferably 0.5 to 2 mm. The thickness of the stretchable nonwoven fabric 2 is measured by the same method as the measurement of the thickness of each of the inelastic fiber layers 22 and 23 described above.

As described above, the stretchable laminated sheet 1 of the second embodiment is composed of “a large number of elastic filaments 24 arranged so as to extend in one direction without crossing each other” in the stretchable nonwoven fabric 2. It is comprised similarly to the elastic laminated sheet 1 of 1st Embodiment except the point currently performed.
Therefore, according to the stretchable laminated sheet 1 of the second embodiment, the same effects as those of the first embodiment are exhibited. In addition, since the elastic fiber aggregate 21 is composed of a large number of elastic filaments 24 and the elastic fiber aggregate 21 is not continuous in the surface direction of the stretchable laminated sheet 1, the elastic fiber aggregate 21 is not easily distorted. In addition, since there is a region where the first non-elastic fiber layer 22 and the second non-elastic fiber layer 23 are directly joined (that is, between the elastic filaments 24 and 24), the entire stretchable laminated sheet 1 is stretched and contracted. Excellent responsiveness.

  In the stretchable laminated sheet 1 of the second embodiment, since the elastic filaments 24 have the same diameter and are arranged at an equal pitch, the elongation stress is the same regardless of which part of the stretchable nonwoven fabric 2 is taken. It was. However, instead of this, the stretchable nonwoven fabric 2 may be configured to be composed of two or more regions having different extension stresses in the extension direction of the elastic filament 24. Two or more of the regions are arranged substantially in parallel with the extending direction. In this case, the pitches of the adjacent elastic filaments 24 are different and / or the diameters of the elastic filaments 24 are different between the regions having different elongation stresses. Thereby, the elongation stress can be made different between the regions. When the elastic nonwoven fabric 2 is manufactured, two or more different resins can be introduced into an arbitrary spinning nozzle and spun to perform different elongation stresses between the regions.

  The stretchable nonwoven fabric 2 can be partially embossed, the elastic filament 24 can be partially cut, or it can be partially heat sealed. These operations are performed for the purpose of forming a non-stretchable portion in the stretchable nonwoven fabric 2 or partially increasing the strength. Alternatively, it is performed for the purpose of bonding with other members or providing design.

Next, one manufacturing method of stretchable nonwoven fabric 2 in the second embodiment (hereinafter also referred to as “manufacturing method of the fourth embodiment”) will be described with reference to FIG.
In the manufacturing method of the fourth embodiment, non-elastic fiber layers 22 and 23 in the form of nonwoven fabric are used. As shown in FIG. 13, a large number of molten elastic filaments 24 spun from the spinning nozzle 73 are drawn and stretched at a predetermined speed, and before the elastic filaments 24 are solidified, the elastic filaments 24 cross each other. The elastic filaments 24 are fused to the non-elastic fiber layers 22 and 23 so that they are arranged in one direction, and then the non-elastic fiber layers 22 and 23 to which the elastic filaments 24 are fused are arranged in the direction in which the elastic filaments 24 extend. And stretchability is imparted to the inelastic fiber layers 22 and 23.

  The spinning nozzle 73 is provided in the spinning head 74. The spinning head 74 is connected to the extruder. The resin can be supplied to the spinning head 74 via a gear pump. The elastic resin melt-kneaded by the extruder is supplied to the spinning head 74. In the spinning head 74, a large number of spinning nozzles 73 are arranged in a straight line. The spinning nozzle 73 is disposed along the width direction of the first inelastic fiber layer 22 and the second inelastic fiber layer 23. The interval between the adjacent spinning nozzles 73 corresponds to the interval between the elastic filaments 24 in the target stretchable nonwoven fabric 2.

  The spinning nozzle 73 is generally circular, and its diameter affects the diameter of the elastic filament 24 and the draw ratio. From this viewpoint, the diameter of the spinning nozzle 73 is preferably 0.1 to 2 mm, particularly preferably 0.2 to 0.6 mm. For the purpose of increasing the bonding strength with the non-elastic fiber layers 22, 23, the purpose of increasing the spinnability of the elastic filament 24, and the purpose of improving the stretch properties of the stretchable nonwoven fabric 2, the elastic filament 24 is in a composite form (side-by-side, core Sheath, sea-island structure). Specifically, it is preferable to combine a PP elastomer resin and a styrene elastomer resin.

  The spun elastic filaments 24 spun together with the first non-elastic fiber layer 22 and the second non-elastic fiber layer 23, which are unwound from the raw fabric, at the same speed, and both inelastic. It is sandwiched between the fiber layers 22 and 23 and taken up at a predetermined speed. The take-up speed of the elastic filament 24 coincides with the feeding speed of both inelastic fiber layers 22 and 23. The take-up speed of the elastic filament 24 affects the diameter of the elastic filament 24 and the draw ratio. The tension generated in the elastic filament 24 by stretching prevents the elastic filament 24 from being disturbed due to wind or static electricity when the elastic filament 24 is bonded to the non-elastic fiber layers 22 and 23. Thereby, the elastic filaments can be arranged in one direction without crossing each other. From these viewpoints, the drawing speed of the elastic filament 24 is 1.1 to 400 times, particularly 4 to 100 times, and more preferably 10 to 80 times the resin discharge speed in the hole of the spinning nozzle 73. It is preferable to adjust so.

  The elastic filament 24 merges with the first inelastic fiber layer 22 and the second inelastic fiber layer 23 before being solidified, that is, in a state capable of being fused. As a result, the elastic filament 24 is fused to the inelastic fiber layers 22 and 23 while being sandwiched between the first inelastic fiber layer 22 and the second inelastic fiber layer 23. That is, the elastic filament 24 is pulled and stretched by fusing the elastic filament 24 before solidification to the conveyed non-elastic fiber layers 22 and 23. When the elastic filament 24 is fused, heat is not applied to the first inelastic fiber layer 22 and the second inelastic fiber layer 23 from the outside. That is, the elastic filament 24 and both inelastic fiber layers 22 and 23 are fused only by the heat of fusion caused by the elastic filament 24 that can be fused. As a result, among the constituent fibers of both the non-elastic fiber layers 22 and 23, only the fibers existing around the elastic filament 24 are fused to the elastic filament, and the fibers existing further away from the elastic filament 24 are not fused. . As a result, since the heat applied to both inelastic fiber layers 22 and 23 is kept to a minimum, the good texture inherent to the inelastic fiber layers 22 and 23 themselves is maintained. Thereby, the texture of the stretchable nonwoven fabric 2 obtained becomes favorable.

  Until the spun elastic filament 24 merges with the first inelastic fiber layer 22 and the second inelastic fiber layer 23, the elastic filament 24 is stretched and molecules are oriented in the stretching direction. Also, the diameter is reduced. Due to the molecular orientation, an elastic filament 24 with a small 50% elongation strength / return ratio (hysteresis) is obtained. From the viewpoint of sufficiently stretching the elastic filament 24 and spinning the yarn breakage of the elastic filament 24, wind of a predetermined temperature (hot air or cold air) is blown onto the spun elastic filament 24, and the temperature of the elastic filament 24 is adjusted. You may adjust.

  The stretching of the elastic filaments 24 may be not only stretching in the molten state of the elastic resin (melt stretching) but also stretching in the softened state (softening stretching) in the cooling process. The molten state is a state in which the resin flows when an external force is applied. The melting temperature of the resin is measured as a peak temperature of Tan δ by viscoelasticity measurement (for example, measured by adding vibration strain in the rotational direction to a resin sandwiched between circular parallel plates). In order to prevent thread breakage during stretching of the elastic resin, it is preferable to secure a long stretching section. From this viewpoint, the melting temperature of the elastic resin is preferably 130 to 300 ° C. Further, from the viewpoint of heat resistance (molding temperature) of the elastic resin, the melting temperature is preferably 130 to 220 ° C. The softening temperature is measured as the Tg temperature in the viscoelastic property of the measurement sample of the elastic resin in sheet form. The range from the softening temperature to the melting temperature is called a softened state. The softening temperature is preferably 60 ° C. or higher, and more preferably 80 ° C. to 180 ° C., from the viewpoint of the growth of elastic resin crystals during storage of the elastic nonwoven fabric 2 and the decrease in the elastic properties of the elastic nonwoven fabric 2 due to body temperature.

  The temperature of the elastic filament 24 when the elastic filament 24 and the non-elastic fiber layers 22 and 23 are bonded is preferably 100 ° C. or higher in order to ensure fiber fusion. Moreover, from the viewpoint of obtaining the elastic nonwoven fabric 2 having good elastic properties while maintaining the shape of the elastic filament 24, the temperature of the elastic filament is preferably 180 ° C or lower, more preferably in the range of 120 to 160 ° C. is there. The bonding temperature is observed using a film made of modified polyethylene or modified polypropylene having a melting point different from the melting point of the elastic resin constituting the elastic filament as a laminate base material to be bonded to the elastic filament 24. Can be measured. At this time, if the elastic filament and the laminate base material are fused, the joining temperature is equal to or higher than the melting point of the laminate base material.

  At the time of joining the elastic filament 24 and the non-elastic fiber layers 22 and 23, the elastic filament 24 is substantially in an unstretched state (a state in which the elastic filament 24 does not shrink when an external force is removed). In the bonded state of the two, at least a part of the fibers constituting the non-elastic fiber layers 22 and 23 are fused to the elastic filament, or further, the fibers constituting the elastic filament 24 and the non-elastic fiber layers 22 and 23 are It is more preferable that both at least a part are fused. This is because sufficient bonding strength can be obtained. The stretch characteristics of the resulting stretchable nonwoven fabric 2 are affected by the density of the joint points between the elastic filament 24 and the non-elastic fiber layers 22 and 23. In addition, the expansion / contraction characteristics can be adjusted by the joining temperature, the joining pressure, and the detachment of the joining point due to the stretching of the inelastic fiber layers 22 and 23 described later. By fusing the constituent fibers of the non-elastic fiber layers 22 and 23 to the elastic filament 24, the bonding strength of each bonding point increases. It is preferable to reduce the density of the bonding points because the stretch inhibition by the non-elastic fiber layers 22 and 23 is reduced and the stretchable nonwoven fabric 2 having a sufficient bond strength can be obtained.

  When the elastic filaments 24 are joined with the first inelastic fiber layer 22 and the second inelastic fiber layer 23, the elastic filaments 24 are arranged in one direction without crossing each other. Then, the elastic filament 24 is joined with the first inelastic fiber layer 22 and the second inelastic fiber layer 23 so that the elastic filament 24 is sandwiched between the inelastic fiber layers 22 and 23. A person is clamped by a pair of nip rolls 75, 75. The condition of the clamping pressure affects the texture of the stretchable nonwoven fabric 2 to be obtained. If the sandwiching pressure is too large, the elastic filaments 24 are likely to bite into the two inelastic fiber layers 22 and 23, and the texture of the stretchable nonwoven fabric 2 obtained thereby tends to be lowered. From this point of view, the clamping force by the nip rolls 75 and 75 only needs to be such that the elastic filament 24 contacts both the inelastic fiber layers 22 and 23, and an excessively high clamping pressure is not required.

  Another condition for the clamping pressure by the nip roll 75 is the temperature of the nip roll 75. The stretchable nonwoven fabric 2 having a good texture can be obtained by not performing heating (that is, depending on the outcome) or by performing clamping while cooling, rather than performing clamping while the nip roll 75 is heated. When cooling the nip roll 75, it is preferable to use a coolant such as cooling water and adjust the temperature so that the surface setting temperature of the nip roll 75 is 10 to 50 ° C.

In this way, an unembossed fiber sheet 2 ″ in which the elastic filament 24 is sandwiched between the two non-woven non-elastic fiber layers 22 and 23 is obtained.
When the non-elastic fiber layers 22 and 23 are inherently stretchable, the unembossed fiber sheet 2 ″ becomes the stretchable nonwoven fabric 2 itself. Using this, the first to third embodiments are used. By the process similar to the aspect, the moisture permeable film 3 can be bonded to the entire stretchable nonwoven fabric 2 to form the stretchable laminated sheet 1 of the second embodiment.

  On the other hand, when the non-elastic fiber layers 22 and 23 that are not inherently stretchable are used, the first to third embodiments are applied to the unembossed fiber sheet 2 ″ including the non-elastic fiber layers 22 and 23. The moisture permeable film 3 is entirely bonded by the same process as described above to obtain a flat laminated sheet 1 ′, and the flat laminated sheet 1 ′ is stretched along the direction in which the elastic filament 24 extends, The stretchable laminated sheet 1 of the second embodiment can be formed by performing an operation to impart extensibility to the inelastic fiber layers 22 and 23.

  In the manufacturing method of the fourth embodiment, in the drawing process performed after the elastic filament 24 is bonded to the non-elastic fiber layers 22 and 23, the drawing direction is preferably only the flow direction of the non-elastic fiber layers 22 and 23. However, it may be diagonal. Furthermore, it is possible to combine two or more stretching methods, increase the stretching ratio stepwise, or perform partial stretching. The stretching direction may be not only one direction but also two orthogonal directions. A non-woven fabric that expands and contracts in one direction and a non-woven fabric that expands and contracts in a direction perpendicular to the non-woven fabric can be joined to give stretchability in all directions of the stretchable sheet.

  Moreover, in the manufacturing method of the fourth embodiment, as another method of joining the elastic filament 24 and the non-elastic fiber layers 22 and 23, without melting and stretching the elastic filament 24 on one of the non-elastic fiber layers. Direct extrusion is also possible. In this case, the draw ratio is 1 time. Further, before joining the elastic filament 24 and the non-elastic fiber layers 22 and 23, an adhesive is applied to the non-elastic fiber layers 22 and 23 or the elastic filament 24, and then the elastic filament 24 is attached to the non-elastic fiber layers 22 and 23. 23 can be bonded together in a substantially unstretched state. Further, after the elastic filament 24 and the non-elastic fiber layers 22 and 23 are stacked without applying an adhesive, heat treatment (hot air blowing by air-through method, steam jet, heat embossing), mechanical entanglement (needle punch, Span lace) can also be performed. At this time, the fiber web-shaped non-elastic fiber layers 22 and 23 can be used in place of the non-woven non-elastic fiber layers 22 and 23.

The stretchable laminated sheet of the present invention is not limited to the above-described embodiments, and can be appropriately changed.
The elastic fiber assembly is the elastic fiber layer 21 formed in a layer shape in the first embodiment, and in the second embodiment, “a large number of elastic filaments arranged so as to extend in one direction without intersecting each other”. 24 ”, but is not limited thereto. For example, the elastic fiber assembly is mainly composed of short fibers and / or filaments, but may not have a complete layer structure (partially omitted in the thickness direction). May be formed by crossing.

  The manufacturing method of the stretchable laminated sheet of the present invention is not limited to the above-described embodiments, and can be appropriately changed. For example, in each of the above-described embodiments, the moisture permeable film 3, the first inelastic fiber layer 22, the elastic fiber assembly 21, and the second inelastic fiber layer 23 have an integrally wavy shape. However, the method for producing the stretchable laminated sheet of the present invention is not limited to this, and the moisture permeable film 3, the first non-elastic fiber layer 22 and the elastic fiber aggregate are not limited thereto. The present invention can be applied to the production of a stretchable laminated sheet 1 (not shown) in which the three layers 21 have a wavy shape integrally.

  Moreover, in the manufacturing method of each above-mentioned embodiment, although moisture-permeable film continuous body 3 'is used, in the manufacturing method of the stretchable laminated sheet of this invention, moisture-permeable film continuous body 3' is not used. The moisture permeable film 3 that has been cut into a predetermined shape is intermittently supplied to the embossed fiber sheet 2 ′ to form a flat laminated sheet 1 ′ in which the moisture permeable film 3 is intermittently bonded. (Not shown). In that case, it is preferable to apply an adhesive partially only to the area | region where the moisture-permeable film 3 in the to-be-embossed fiber sheet 2 'is joined. Further, the adhesive may be applied to the moisture permeable film 3 in order to facilitate the synchronization of the phase of the adhesive and the moisture permeable film 3.

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

[Example 1-1]
Example 1-1 is an example corresponding to the first embodiment.
The stretchable nonwoven fabric 2 was formed as follows. Short fiber (core: PET, sheath: PE) having a diameter of 18 μm, a fiber length of 44 mm, and a maximum elongation of 160% is supplied to the card machine, and a basis weight of the card web: 10 g / m ² inelastic fiber layer 22 was formed. The elastic fiber layer 21 was formed by directly laminating a fiber having a fiber diameter of 21 μm and a basis weight of 15 g / m ² on the non-elastic fiber layer 22 by a spinning blow method using a styrene elastomer resin as a constituent fiber. . Furthermore, a non-elastic fiber layer 23 having a basis weight of 10 g / m ² made of short fibers similar to the non-elastic fiber layer 22 described above was laminated on the elastic fiber layer 21.

These three-layer web laminates were introduced into a hot air treatment machine (dryer 54), and hot air was blown by an air-through method to perform hot air treatment (fiber fusion). The hot air treatment conditions were: net temperature: 137 ° C., hot air flow rate: 2 m / second, spray pressure: 0.1 kg / cm ² , spray time: 15 seconds. By this hot air treatment, an unembossed fiber sheet 2 ″ in which three layers of webs were integrated was obtained.
Subsequently, the unembossed fiber sheet 2 ″ was subjected to hot embossing. The hot embossing was performed using an embossing device 55 including an embossing roll 56 and a receiving roll 57 that is a metal flat roll. A dot-shaped convex roll having a large number of convex portions with a pitch of 2.0 mm in both the CD direction and the MD direction was used as 56. The temperature of each roll was set to 120 ° C. By this hot embossing, the joint portion was The elastic nonwoven fabric 2 formed in a regular pattern was obtained.

Further, as the moisture permeable film 3, 100 parts by weight of low-density polyethylene (Ultzex 2520F, manufactured by Mitsui Petrochemical Co., Ltd.), 150 parts by weight of calcium carbonate (Escalon # 2000, manufactured by Mitsui Seiko Co., Ltd.), stearic acid A resin composition consisting of 2 parts by weight (Lunac S-40, manufactured by Kao Corporation) and 11 parts by weight of polyester (TM20AS, manufactured by Kao Corporation) was pre-kneaded and granulated, and then using a single screw extruder. A porous sheet obtained by performing inflation molding and further uniaxially stretching 2.1 times in the molding direction using a roll stretching machine was used. The moisture permeability is 1.6 g / 100 cm ² · hr, and the basis weight is 20 g / m ² . The “moisture permeability” here is measured by the following [Method of measuring moisture permeability].
[Measurement method of moisture permeability]
The moisture permeability is measured in accordance with JIS Z0208 (changing the test piece area and test time). That is, the moisture permeation amount (g / 100 cm ² · hr) per hour from 100 cm ² of the test piece is measured under an environment of 30 ° C. and 90% RH.

The stretchable nonwoven fabric 2 and the moisture permeable film 3 are joined together by a hot spray adhesive applied to a basis weight of 4 g / m ² by a slot spray method to obtain a flat laminated sheet 1 ′. Got.
The flat laminated sheet 1 ′ was stretched so that the flat laminated sheet 1 ′ can be expanded and contracted in the CD direction, as shown in FIG. In the stretching process, the pitch P between the concavo-convex roll 63 and the concavo-convex roll 64 was 1.0 mm, and the stretching ratio was set to 3.0 times by adjusting the pressing amount of the upper and lower concavo-convex rolls 63 and 64. Thus, the stretchable laminated sheet 1 of Example 1-1 was obtained.

[Example 1-2]
Compared with Example 1-1, the stretching process of the flat laminated sheet 1 ′ was performed so that the flat laminated sheet 1 ′ can expand and contract in the MD direction as shown in FIG. Other than that is the same as that of Example 1-1.

[Comparative Example 1-1]
The comparative example 1-1 is not performing the extending | stretching process of flat laminated sheet 1 'compared with Example 1-1. Other than that is the same as that of Example 1-1. That is, Comparative Example 1-1 is the flat laminated sheet 1 ′ itself in Example 1-1.

[Comparative Example 1-2]
Comparative Example 1-2 does not include the moisture permeable film 3 as compared with Comparative Example 1-1. Other than that is the same as that of Comparative Example 1-1. That is, Comparative Example 1-2 is the stretchable nonwoven fabric 2 itself in Comparative Example 1-1.

[Comparative Example 1-3]
Comparative Example 1-3 does not include the stretchable nonwoven fabric 2 as compared with Comparative Example 1-1. Other than that is the same as that of Comparative Example 1-1. That is, Comparative Example 1-3 is the moisture-permeable film 3 itself in Comparative Example 1-1.

[Example 2-1]
Example 2-1 is an example corresponding to the second embodiment.
As each inelastic fiber layer 22 and 23, the air through nonwoven fabric of basic weight: 20g / m < ² > was used. The constituent fiber of this nonwoven fabric was a core-sheath type composite fiber (core: PET, sheath: PE) having a diameter: 19 μm, maximum elongation: 180%, and fiber length: 44 mm.
As the raw resin for the elastic filament 24, an elastomer made of SEPS resin [weight average molecular weight: 50,000, MFR: 60 g / min (230 ° C., 2.16 kg)] was used. The spinning conditions were: spinning head temperature: 310 ° C., spinning nozzle diameter: 400 μm, spinning nozzle pitch: 1 mm, and draw ratio: 11 times. The diameter of the elastic filament was 120 μm, and the basis weight of the elastic filament was 8 g / m ² . Under such manufacturing conditions, the stretchable nonwoven fabric 2 of Example 2-1 was obtained.

[Comparative Example 2-1]
In Comparative Example 2-1, the flat laminated sheet 1 ′ is not stretched as compared with Example 2-1. Other than that is the same as that of Example 2-1. That is, Comparative Example 2-1 is the flat laminated sheet 1 ′ itself in Example 2-1.

[Comparative Example 2-2]
The comparative example 2-2 does not include the moisture permeable film 3 as compared with the comparative example 2-1. Other than that is the same as that of Comparative Example 2-1. That is, Comparative Example 2-2 is the stretchable nonwoven fabric 2 itself in Comparative Example 2-1.

[Comparative Example 2-3]
Comparative Example 2-3 does not include the stretchable nonwoven fabric 2 as compared with Comparative Example 2-1. Other than that is the same as that of Comparative Example 2-1. That is, Comparative Example 2-3 is the moisture permeable film 3 itself in Comparative Example 2-1.

〔Evaluation methods〕
For each of the examples and comparative examples, the moisture permeability is measured by the above [Method of measuring moisture permeability] to evaluate the level of moisture permeability. The moisture permeability measured for each example and comparative example is shown in the following [Table 1] or [Table 2].

From the measurement results shown in Table 1, for example, the following can be understood.
In the flat laminated sheet 1 ′ (ie, Comparative Example 1-1) in which the moisture permeable film 3 is bonded to the stretchable nonwoven fabric 2, the stretchable nonwoven fabric 2 alone (ie, Comparative Example 1-2) and the moisture permeable film 3 alone (ie, the comparison). The moisture permeability is lower than in Example 1-3). This is because the materials are laminated and bonded with an adhesive.
On the other hand, by stretching the flat laminated sheet 1 ′ of Comparative Example 1-1, the stretchable laminated sheet 1 having good touch and stretchability while preventing and reducing the moisture permeability and maintaining and improving the moisture permeability ( That is, Examples 1-1 and 1-2) could be obtained.
The same effect was obtained even if it extended | stretched in any of the CD direction (Example 1-1) and MD direction (Example 1-2). In particular, even when the moisture permeable film was stretched in the MD direction, it was confirmed that the stretching could be performed without damaging the material if it was stretched to the extent of these conditions. Therefore, the present invention is a stretchable laminated sheet that achieves both stretchability and improved moisture permeability in both the MD direction and the CD direction.

From the measurement results shown in [Table 2], for example, the following can be understood.
Also in the second embodiment, the stretchable laminated sheet 1 (i.e., the touch and stretchability is good while preventing the decrease in the moisture permeability and maintaining and improving the moisture permeability by performing the stretching process as in the first embodiment. Example 2-1) could be obtained.
In the second embodiment, after stretching in the MD direction, the stretchable nonwoven fabric 2 can be stretched with a small amount of strain. Therefore, the stretchable laminated sheet 1 is also less strained when stretched, has excellent stretchability, and has a good appearance. Also, uneven ridges are formed well. Therefore, a stretchable laminated sheet having a good texture and appearance and having both improved stretchability and moisture permeability was obtained.

FIG. 1 is a schematic diagram showing a cross-sectional structure of the first embodiment of the stretchable laminated sheet of the present invention. Drawing 2 is a mimetic diagram showing the manufacture device which enforces the 1st embodiment of the manufacturing method of the elastic lamination sheet of the present invention used for manufacture of the elastic lamination sheet of a 1st embodiment. Fig.3 (a) is sectional drawing which shows the state before an elastic nonwoven fabric and a moisture-permeable film contact | abut, FIG.3 (b) shows the state to which the elastic nonwoven fabric and the moisture-permeable film were joined. It is sectional drawing. FIG. 4 is a cross-sectional view illustrating a state in which a flat laminated sheet is stretched in the CD direction between a pair of concave and convex rolls. FIG. 5 is an enlarged cross-sectional view showing a state in which a flat laminated sheet is stretched in the CD direction between a pair of concave and convex rolls. FIG. 6 is a schematic view showing a production apparatus for carrying out the first stage of the second embodiment of the production method of the stretchable laminated sheet of the present invention. FIG. 7 is a schematic view showing a production apparatus for carrying out the latter stage of the second embodiment of the method for producing a stretchable laminated sheet of the present invention. FIG. 8 is a schematic view showing a production apparatus for carrying out the first stage of the third embodiment of the method for producing a stretchable laminated sheet of the present invention. FIG. 9 is a schematic view showing a production apparatus for carrying out the latter stage of the third embodiment of the method for producing a stretchable laminated sheet of the present invention. FIG. 10 is a perspective view showing a state in which a flat laminated sheet is stretched in the MD direction between a pair of concave and convex rolls. FIG. 11 is a cross-sectional view showing a state in which a flat laminated sheet is stretched in the MD direction between a pair of concave and convex rolls. FIG. 12: is a perspective view which fractures | ruptures and shows a part about the elastic nonwoven fabric in the elastic laminated sheet of 2nd Embodiment. FIG. 13: is a schematic diagram which shows the manufacturing apparatus which implements the 4th embodiment of the manufacturing method of the elastic laminated sheet of this invention used for manufacture of the elastic nonwoven fabric in the elastic laminated sheet of 2nd Embodiment.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Elastic laminate sheet 11,12 Base surface 2 Elastic nonwoven fabric 21 Elastic fiber layer (elastic fiber aggregate)
22 1st inelastic fiber layer 23 2nd inelastic fiber layer 24 Elastic filament 3 Moisture permeable film 41 1st groove 42 2nd groove

Claims (5)

A substantially inelastic first inelastic fiber layer and a second inelastic fiber layer are disposed on both surfaces of the elastic fiber assembly, respectively, and the adjacent elastic fiber assembly and the inelastic fiber layer are heat-sealed. A stretch laminated sheet in which a moisture permeable film is entirely joined to the first inelastic fiber layer in the stretch nonwoven fabric joined by
The moisture permeable film, the first inelastic fiber layer, the elastic fiber assembly, and the second inelastic fiber layer integrally have a wavy shape,
On the moisture permeable film side and the second inelastic fiber layer side in the stretchable laminated sheet, a plurality of parallel first and second ridges are formed, respectively.
The first groove is formed by bending an outer surface of the moisture permeable film with respect to a base surface, and the second groove has an outer surface of the second inelastic fiber layer on the base surface. An elastic laminate sheet that is smoothly recessed.   The stretchable laminated sheet according to claim 1, wherein the first inelastic fiber layer has extensibility. Expansion / contraction in which a substantially inelastic first inelastic fiber layer is disposed on at least one surface of the elastic fiber assembly, and the elastic fiber assembly and the first inelastic fiber layer are joined by thermal fusion A moisture permeable film is entirely bonded to the first non-elastic fiber layer in the porous nonwoven fabric, and the moisture permeable film, the first non-elastic fiber layer, and the elastic fiber aggregate integrally have a wavy shape. A method for producing a stretchable laminated sheet in which a plurality of first and second ridges arranged in parallel on the moisture permeable film side and the opposite side thereof are formed,
After or simultaneously with the step of joining the first inelastic fiber layer and the moisture permeable film in the stretchable nonwoven fabric to form a flat laminated sheet, large diameter portions and small diameter portions are alternately formed. A method of producing a stretchable laminated sheet by stretching the flat laminated sheet using a stretching apparatus provided with a pair of concave and convex rolls to form the first concave line and the second concave line.   The method for producing a stretchable laminated sheet according to claim 3, wherein the stretchable laminated sheet is further provided with a substantially nonelastic second nonelastic fiber layer on the other surface of the elastic fiber assembly.   The method for producing a stretchable laminated sheet according to claim 3 or 4, wherein the first inelastic fiber layer has extensibility.

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