KR20220066073A - Laminated stretch nonwoven fabric, sanitary material, and manufacturing method of laminated stretch nonwoven fabric - Google Patents

Abstract

The present invention relates to a laminated stretchable nonwoven fabric in which a spunbonded nonwoven fabric layer and an elastomer layer are laminated at least one layer at a time, wherein the spunbonded nonwoven fabric layer includes crimped fibers having a number of crimps of 50 or more per 25 mm.

Description

Laminated stretch nonwoven fabric, sanitary material, and manufacturing method of laminated stretch nonwoven fabric

The present invention relates to a laminated stretchable nonwoven fabric having excellent tactile feel and particularly suitable for use as a sanitary material, and a method for producing the same.

In sanitary materials such as paper diapers and sanitary napkins, elastic members that require elastic adhesion to skin, such as waists and thighs, are required to have good elasticity (properties that stretch and shrink easily) and have excellent tactile feel.

Conventionally, a member to which an elastic yarn and a relaxed non-stretch nonwoven fabric are adhered to the elastic member has been widely used. Although the relaxed non-stretch nonwoven fabric covers the elastic yarn with a sticky feel (hereinafter also referred to as rubber touch), the tightening force of the elastic yarn is uneven due to wrinkles (hereinafter referred to as gather) caused by the relaxation of the non-stretch nonwoven fabric. , making it difficult to obtain a comfortable feel.

With respect to this subject, in patent document 1, the melt blown nonwoven fabric containing a thermoplastic polyurethane is proposed. Moreover, in Patent Document 2, a laminated stretchable nonwoven fabric in which stretching is performed after laminating a non-stretched nonwoven fabric on a spunbonded nonwoven fabric containing a thermoplastic elastomer is proposed. Moreover, in patent document 3, the non-stretch nonwoven fabric which has crimped|stretched non-woven fabric and the elastomer film are laminated|stacked, and then the laminated stretched nonwoven fabric which performed the extending|stretching process is proposed.

Japanese Patent Laid-Open No. 3-19952 Japanese Patent Laid-Open No. 2007-321293 Japanese Patent Laid-Open No. 2000-158593

However, in the technique of patent document 1, since polyurethane itself is excellent in elasticity, although favorable elasticity is obtained also as a nonwoven fabric, the surface of a nonwoven fabric becomes a rubber touch, and it is difficult to obtain a favorable touch.

On the other hand, in the technique of Patent Document 2, the non-stretched non-woven fabric obtained by laminating the spunbonded non-woven fabric layer containing the thermoplastic elastomer and the other non-woven fabric layer and then stretching is performed to avoid rubber touch. can However, when stretched, the non-stretched nonwoven fabric cannot withstand elongation, and there is a problem in that plastic deformation or fracture, and further delamination between layers occurs, and it is difficult to obtain sufficient elongation.

In the technique of Patent Document 3, since the composite fiber with crimping in the spinning step forms a spring-like structure, the plastic deformation of the fiber is easily suppressed by the expansion and contraction of the spring structure. However, also in this technique, since the expansion and contraction in the spring structure is insufficient, it was also difficult to obtain a sufficient elongation. In addition, when a film is used for the stretchable layer, sweating or skin disease may occur depending on the configuration.

Then, the objective of this invention was made in view of the said circumstances, and it is providing the laminated stretchable nonwoven fabric which can make compatible the elongation rate sufficient for use as a nonwoven fabric for hygiene materials, and excellent touch.

As a result of repeated intensive studies to achieve the above object, the present inventors have found that, in the laminated stretchable nonwoven fabric, by using a specific spunbond nonwoven fabric layer, a stretch ratio sufficient for use as a nonwoven fabric for sanitary materials and an expansion and contraction that can achieve both excellent tactile feel The knowledge that a nonwoven fabric was obtained was acquired.

The present invention has been completed based on these findings, and according to the present invention, the following inventions are provided.

The laminated stretchable nonwoven fabric of the present invention is a laminated stretchable nonwoven fabric formed by laminating at least one spunbonded nonwoven fabric layer and at least one elastomer layer, wherein the spunbonded nonwoven fabric layer contains crimped fibers having a number of crimps of 50 or more per 25 mm.

According to a preferred aspect of the laminated stretchable nonwoven fabric of the present invention, the above-described elastomer layer is a melt blown nonwoven fabric layer.

According to a preferred aspect of the laminated stretchable nonwoven fabric of the present invention, the laminated stretchable nonwoven fabric has a regular pattern of fusion-bonded portions.

According to a preferred aspect of the laminated stretchable nonwoven fabric of the present invention, the spacing between adjacent fusion-bonded portions is 50 µm or more and 20 mm or less.

The sanitary material of the present invention is at least partially constituted by the above-described laminated stretchable nonwoven fabric.

In the method for producing a laminated stretchable nonwoven fabric of the present invention, when the melting point of the thermoplastic resin having the lowest melting temperature in the thermoplastic resin constituting the crimped fiber for the spunbond fiber including the crimped fiber is Tm, Tm-100° C. or higher After heat treatment at a temperature to form a spunbond nonwoven fabric layer, at least one elastomer layer is laminated on the spunbonded nonwoven fabric layer.

According to a preferred aspect of the method for producing a laminated stretchable nonwoven fabric of the present invention, the above-described elastomer layer is formed by a melt blow method.

According to a preferred aspect of the manufacturing method of the laminated stretchable nonwoven fabric of the present invention, the spunbond nonwoven fabric layer and the elastomer layer are laminated and then integrated so as to have a fusion portion having a regular pattern.

According to a preferred aspect of the method for manufacturing a laminated stretchable nonwoven fabric of the present invention, the spacing between the adjacent fusion-bonded portions of the crimped fibers constituting the spunbonded nonwoven fabric layer is 50 µm or more and 20 mm or less.

According to the present invention, it is possible to obtain a laminated stretchable nonwoven fabric capable of achieving both an elongation sufficient for use as a nonwoven fabric for sanitary materials and an excellent tactile feel.

1 is a conceptual diagram illustrating a part of a projection portion (convex portion) disposed on the surface of an embossing roll used in Example 3. FIG.

The laminated stretchable nonwoven fabric of the present invention is a laminated stretchable nonwoven fabric formed by laminating at least one spunbonded nonwoven fabric layer and at least one elastomer layer, wherein the spunbonded nonwoven fabric layer contains crimped fibers having a number of crimps of 50 or more per 25 mm. Hereinafter, although the component is demonstrated in detail, this invention is not limited at all to the range demonstrated below unless the summary is exceeded.

[Spunbond nonwoven fabric layer]

The spunbonded nonwoven fabric layer according to the laminated stretchable nonwoven fabric of the present invention is a layer composed of a spunbonded nonwoven fabric. In addition, the spunbond nonwoven layer contains crimped fibers having a number of crimps of 50 or more per 25 mm. The number of crimps per 25 mm of the crimped fibers is 50 or more, preferably 75 or more, and more preferably 100 or more. By carrying out in this way, while a large elongation rate is obtained, it can be set as the laminated stretchable nonwoven fabric which has a soft touch. Moreover, since it differs with the fineness of the crimped fiber, although an upper limit is not specifically limited with respect to the number of crimps per 25 mm, For example, 1000 or less are preferable and 750 or less are more preferable.

The number of crimps per 25 mm of crimped fibers can be measured, for example, by the following method.

(1) The crimped fiber is observed and photographed with a microscope.

(2) From the photographed fiber image, the apparent length of the crimped fiber in the measurement range is measured.

(3) Count all the mountains and valleys of the crimp fiber in its apparent length.

(4) Divide the total number of the mountains and valleys by 2.

(5) Convert the total number to the number per 25mm.

The spunbonded nonwoven fabric layer according to the laminated stretchable nonwoven fabric of the present invention preferably contains a thermoplastic resin from the viewpoint of productivity. The number of such a thermoplastic resin may be one, and the thing containing a some thermoplastic resin may be sufficient as it. Examples of the thermoplastic resin include aromatic polyester polymers and copolymers thereof such as "polyethylene terephthalate, polytrimethylene terephthalate, polybutylene terephthalate, and polyhexamethylene terephthalate", and "polylactic acid, polyethylene succinate, polybutyl Aliphatic polyester polymers such as lensuccinate, polybutylene succinate adipate, polyhydroxybutyrate-polyhydroxyvalylate copolymer, and polycaprolactone, and copolymers thereof, “polyamide 6, polyamide” 66, polyamide 610, polyamide 10, polyamide 12, polyamide 6-12, etc. aliphatic polyamide-based polymers and copolymers thereof, and polyolefin-based polymers such as “polypropylene, polyethylene, polybutene, polymethylpentene” and copolymers thereof, water-insoluble ethylene-vinyl alcohol copolymer-based polymers containing 25 to 70 mol% of ethylene units, polystyrene-based, polydiene-based, chlorine-based, polyolefin-based, polyester-based, polyurethane-based, and polyamide-based polymers , fluorine-based elastomer-based polymers, and the like, and can be used by selecting them from among them. In particular, the last exemplified thermoplastic resin of the group other than the elastomeric polymer, i.e., the aforementioned aromatic polyester polymer and copolymer, aliphatic polyester polymer and copolymer, aliphatic polyamide polymer and copolymer thereof, polyolefin Polymers, copolymers thereof, and ethylene-vinyl alcohol copolymer polymers are preferable because the feel of the laminated stretchable nonwoven fabric is easily deformed like rubber, and it is difficult to achieve recovery (rubber touch).

In addition, the "elastomeric polymer" in the spunbonded nonwoven fabric layer of this invention means the thermoplastic resin which has rubber elasticity at normal temperature.

In the spunbond nonwoven fabric layer of the present invention, it is preferable that the crimped fibers as constituent fibers contain the above-described thermoplastic resin. Among them, it is preferable that the crimped fibers have two types of thermoplastic resins each having a region within the crimped fiber, and each region having an interface therebetween. These crimped fibers are side-by-side fibers, eccentric core-sheath-like types of composite fibers. By taking the form of these conjugated fibers, in the spunbond nonwoven fabric layer, fibers having a desired crimped state can be easily formed.

[Elastomer layer]

The elastomer layer of the laminated stretchable nonwoven fabric of the present invention is an elastomer that takes the form of a film, a fabric such as “fabric, knitted fabric, or nonwoven”, a composite material in which the fabric is impregnated with an elastomer resin, and a sheet of these laminates. layer that contains Especially, it is preferable that it is a layer containing a nonwoven fabric, and it is especially preferable that it is a melt blown nonwoven fabric layer containing a melt blown nonwoven fabric. It is because it is easy to obtain air permeability and flexible bending property higher than a film by a melt blown nonwoven fabric.

In addition, the "elastomer" of the elastomer layer of this invention means the substance which has rubber elasticity at room temperature. In particular, from the viewpoint of productivity, it is preferable that the elastomer layer contains a thermoplastic resin. When the elastomer layer contains the thermoplastic resin, the fiber cross section and the shape of the surface can be easily controlled. The thermoplastic resin constituting the elastomer layer refers to a polymer that exhibits thermoplastic properties when heated to a melting point or higher, while exhibiting rubber elasticity properties at room temperature.

The number of such a thermoplastic resin may be one, and the thing containing a some thermoplastic resin may be sufficient as it. Examples of the thermoplastic resin include polyurethane-based elastomers, polypropylene-based elastomers, polyethylene-based elastomers, polyester-based elastomers, polystyrene-based elastomers, polybutadiene-based elastomers, and the like, and are generally polymer compounds having a soft segment and a hard segment. The thermoplastic elastomer of the present invention can be appropriately selected from among these, from the viewpoint of stretching performance and adhesiveness with the spunbond nonwoven fabric layer and its constituent fibers.

[Lamination stretch nonwoven fabric]

The laminated stretchable nonwoven fabric of the present invention is formed by laminating at least one spunbond nonwoven fabric layer and at least one elastomer layer as described above. That is, as the laminated structure, when the spunbond nonwoven fabric layer is represented as (S) and the elastomer layer is represented as (E), for example, if it is two layers, it is (S)/(E), if it is three layers, it is (S)/(E) /(S) etc., if it is 4 layers, (S)/(E)/(E)/(S) etc., and (S)/(E)/(S)/(E)/(S) etc. Among them, a form in which a spunbond nonwoven fabric layer is laminated on the front and back surfaces of the elastomer layer, that is, (S)/(E)/(S) or (S)/(E)/(S)/(E)/(S) ) is more preferable. This lamination structure is selected according to the purpose of use and the like.

In the laminated stretchable nonwoven fabric of the present invention, it is preferable that the spunbond nonwoven fabric layer and the elastomer layer are integrated. Integration as used herein means that these layers are joined by entanglement of fibers, fixation with components such as an adhesive, and fusion of thermoplastic resins constituting the respective layers.

Among the embodiments in which the laminated stretchable nonwoven fabric of the present invention is integrated with the spunbond nonwoven fabric layer and the elastomer layer, it is preferable to have a fusion portion having a regular pattern. By doing so, not only the appearance of the laminated stretchable nonwoven fabric is uniformly uniform, but also the laminated stretchable nonwoven fabric excellent in mechanical properties such as bending and tensile strength can be obtained.

Here, the "fusion part" in the laminated stretchable nonwoven fabric of the present invention means that the spunbond nonwoven fabric layer and the elastomer layer are fused by an emboss roll, flat roll, other known fusion means, or a combination thereof. points to a part This fusion portion is, for example, pressed by the projections of the heated emboss roll with respect to the lamination of the spunbond nonwoven fabric layer and the elastomer layer, so that the constituent fibers of the spunbond nonwoven fabric layer and the elastomer layer in contact with the projections are formed. It is formed by melting locally, and then cooling the part to solidify.

In addition, in the laminated stretchable nonwoven fabric of the present invention, "having a regular pattern of fusion-bonded parts" means that fusion-bonded parts of a similar shape or a group thereof are periodically and repeatedly arranged on the laminated stretchable nonwoven fabric. Specifically, for example, an aspect in which fusion portions are arranged in stripes or checkered patterns, "equilateral triangles, isosceles triangles, squares, rectangles, trapezoids, parallelograms, rhombuses, regular hexagons", etc. The aspect etc. in which an addition is arrange|positioned are mentioned. In addition, the shape of the "point" of the point-like fusion part includes a circle shape, an oval shape, a capsule shape, a substantially triangular shape, a substantially rectangular shape, and the like. Here, the term "approximately triangular" or "approximately quadrangle" includes those in which the vertices of a triangle or a quadrangle are rounded.

Among these aspects, each fusion portion preferably has an area of 50 mm ² or less. When the area of each fused portion is 50 mm ² or less, more preferably 20 mm ² or less, and still more preferably 5 mm ² or less, the laminated stretchable nonwoven fabric having excellent elasticity can be obtained without excessively fusion of the laminated stretchable nonwoven fabric.

Moreover, in the laminated stretchable nonwoven fabric of the present invention, it is preferable that the intervals between adjacent fusion-bonded portions are 50 µm or more and 20 mm or less. When the spacing between the fused portions is 50 μm or more, more preferably 100 μm or more, or 200 μm or more, a plurality of crimped portions of the crimped fibers can be present between the fused portions, and a laminated stretchable nonwoven fabric having a high elastic ratio can be obtained. . On the other hand, when the distance between the fused portions is 20 mm or less, more preferably 10 mm or less, and still more preferably 5 mm or less, a laminated stretchable nonwoven fabric having high tensile strength and fluff resistance can be obtained. Moreover, in the aspect in which the point-like fusion|fusion part is arrange|positioned at the vertex of a polygonal grid|lattice, let the grid spacing of the polygonal grid|lattice be the space|interval between the fusion|fusion parts.

By adopting such an aspect of the fusion zone, in the laminated stretchable nonwoven fabric of the present invention, the number of crimps of the crimped fibers constituting the spunbonded nonwoven fabric layer between the fusion zones is 2 or more. 5 or more are more preferable, and, as for the number of crimps of a crimped fiber, 8 or more are still more preferable. Although an upper limit is not specifically limited, For example, it is set as 50 or less.

The number of crimps between the fusion parts of the present invention (hereinafter, also referred to as the number of crimps per distance between fusion points) is, for example, observing the inside of a square with a side of 1 cm, counting all the fusion points, and the reciprocal of the square root of the number. Let be the distance (cm) between the fusion points. In addition, the number of crimps per 25 mm may be divided by 2.5 to obtain the number of crimps per 1 cm, and this may be divided by the distance between fusion points to calculate the number of crimps per distance between fusion points. In addition, in the case where five or more fusion points are not included in a square having a side of 1 cm, the same calculation can be performed by appropriately expanding the field of view.

It is preferable that thickness of the laminated stretchable nonwoven fabric of this invention is 0.01 mm or more and 1.50 mm or less. When the thickness is 0.05 mm or more, more preferably 0.07 mm or more, and still more preferably 0.09 mm or more, the spunbond nonwoven fabric has moderate cushioning properties. On the other hand, by 1.50 mm or less, more preferably 1.40 mm or less, and still more preferably 1.30 mm or less, the spunbond nonwoven fabric is excellent in bending flexibility.

Although the thickness of the laminated stretchable nonwoven fabric in this invention is not specifically limited, For example, it means the thickness in no load measured with a shape measuring machine (for example, "VR3050" manufactured by Keyence Corporation).

The laminated stretchable nonwoven fabric of the present invention preferably has a weight per unit area of 10 g/m ² or more and 150 g/m ² or less.

When the weight per unit area is 10 g/m ² or more, it is easy to make the laminated stretchable nonwoven fabric a thickness suitable for a sanitary material use, and a laminated stretchable nonwoven fabric having a mechanical strength that can be applied to practical use can be obtained. On the other hand, by being 150 g/m ² or less, more preferably 120 g/m ² or less, and still more preferably 100 g/m ² or less, a laminated stretchable nonwoven fabric having excellent air permeability and flexibility can be obtained.

In addition, the weight per unit area (g / m ² ) of the laminated stretchable nonwoven fabric in the present invention is based on "6.2 mass per unit area" of JIS L1913:2010 "General nonwoven fabric test method", a test piece of 20 cm × 25 cm, It shall be taken as 3 sheets per 1m of width of a sample, and each mass (g) in a standard state is measured, and it shall point out the mass per 1m< ² > computed from the average value.

The laminated stretchable nonwoven fabric of the present invention preferably has an apparent density of 0.050 g/cm ³ or less. When the apparent density of the laminated stretchable nonwoven fabric is 0.050 g/cm ³ or less, more preferably 0.045 g/cm ³ or less, and still more preferably 0.040 g/cm ³ or less, it is easy to obtain a laminated stretch nonwoven fabric excellent in breathability and flexibility, It becomes easier to feel the high volume. Although a minimum is not specifically limited, For example, when it is 0.01 g/cm< ³ > or more, it is easy to obtain the shape stability which can provide practically.

In addition, the apparent density of the laminated stretchable nonwoven fabric used in the present invention is a value obtained by dividing the above-described weight per unit area by the above-described thickness.

[sanitary material]

The sanitary material of the present invention is at least partially composed of the above-described laminated stretchable nonwoven fabric, and has excellent tactile feel and excellent elasticity. In addition, the sanitary material of the present invention is mainly disposable articles used for health-related purposes such as medical care and nursing care, and includes paper diapers, sanitary napkins, gauze, bandages, masks, gloves, and bandages, and the like. Structural members, for example, a top sheet of a paper diaper, a back sheet, a side gather, etc. are also included.

[Method for producing laminated stretchable nonwoven fabric]

In the method for producing a laminated stretchable nonwoven fabric of the present invention, after heat treatment of spunbond fibers containing crimped fibers to form a spunbonded nonwoven fabric layer, at least one elastomer layer is laminated on the spunbonded nonwoven fabric layer.

(1) Formation of spunbond nonwoven fabric layer

In the manufacturing method of the laminated stretchable nonwoven fabric of the present invention, the spunbond fiber including the crimped fiber is drawn by an ejector and drawn to the yarn obtained by melting the above-described thermoplastic resin, spinning it from a spinneret, and then cooling and solidifying it. obtained by doing During this spinning, even a composite fiber using a polymer having different properties or a single polymer can form regions with different molecular orientations on the fiber cross section depending on the degree of cooling, resulting in crimping at the time of spinning, and thereafter It is possible to control the appearance of crimping in the heat treatment.

As the shape of the spinneret or ejector used in the production of the spunbond nonwoven fabric layer of the present invention, various shapes such as a spherical shape and a rectangular shape can be adopted. Especially, it is a preferable aspect to use the combination of a rectangular nozzle and a rectangular ejector from a viewpoint that the usage-amount of compressed air is comparatively small, and fusion|fusion or abrasion of the threads does not occur easily.

In addition, after spinning and drawing by an ejector, stretching, collecting on a moving net to form a nonwoven fiber web, and then thermal bonding to form a spunbond nonwoven layer. In this process, the spunbond fiber containing the above-described crimped fiber is heat-treated. It carries out by spraying hot air before collecting on a net|net specifically, or in the state collected on a net|net. By doing so, the expression of crimps is accelerated, and in particular, the interaction between fibers is small and a high number of crimps can be obtained, which is preferable. In addition, from the viewpoint of increasing the number of crimps, the heat treatment is preferably performed at Tm-100° C. or higher, when the melting point of the thermoplastic resin having the lowest melting temperature in all the thermoplastic resins used for the crimped fiber is Tm, Tm- 80 degreeC or more is more preferable, and Tm-50 degreeC or more is especially preferable. In addition, from the viewpoint of suppressing the fusion between fibers, it is preferable to perform the heat treatment at a temperature of Tm or less.

The melting point of the thermoplastic resin having the lowest melting temperature as used herein refers to the temperature of the lowest among the melting peaks measured by differential scanning calorimetry (DSC) for all the thermoplastic resins used for the crimped fibers.

(2) Formation of the elastomer layer

In the elastomer layer of the laminated stretchable nonwoven fabric of the present invention, the above-described elastomer layer is formed by a known method. In particular, when the elastomer layer is a melt blown nonwoven fabric layer, it is preferable to manufacture by a melt blow method. This is because the sheet can be formed stably as compared with the spunbonding method. In addition, there is an advantage that the fiber diameter can be made smaller than that of the spunbonding method.

(3) Formation of laminated stretchable nonwoven fabric

In the laminated stretchable nonwoven fabric of the present invention, at least one layer of the above-described spunbond nonwoven fabric layer and the elastomer layer are laminated. And, Preferably, these are integrated. Among them, it is more preferable to integrate the laminated spunbond nonwoven fabric layer and the elastomer layer so as to have a fusion portion having a regular pattern.

Specifically, it is preferable to heat an emboss roll and a flat roll having a regular pattern, respectively, and to integrate the spunbond nonwoven fabric layer and the elastomer layer by sandwiching them and pressurizing them together.

Here, the embossing roll having a regular pattern is an embossing roll to which a shape corresponding to a desired "regular pattern fusion part" in the laminated stretchable nonwoven fabric is imparted, for example, a protruding portion ( A convex portion) is formed, or a concave shape is formed in a portion that does not correspond to the fusion portion.

In the method for producing a laminated stretchable nonwoven fabric of the present invention, it is preferable to provide such that the spacing between adjacent fused portions of the crimped fibers constituting the spunbond nonwoven fabric layer is 50 µm or more and 20 mm or less with respect to this fused portion. As described above, by setting the spacing between the fused portions to be 50 μm or more, a plurality of crimped portions of the crimped fibers can be present between the fused portions, and a laminated stretchable nonwoven fabric having a high elastic ratio can be manufactured. On the other hand, when the distance between the fusion-bonded portions is 20 mm or less, it is possible to manufacture a laminated stretchable nonwoven fabric having high tensile strength and fluff resistance.

Example

Next, the present invention will be specifically described based on Examples. However, the present invention is not limited only to these examples. In addition, in the measurement of each physical property, the thing which does not have a special description means that the measurement was performed based on the above-mentioned method.

(1) Number of crimps per 25mm of crimped fiber

The surface of the laminated stretchable nonwoven fabric was imaged with a scanning electron microscope (SEM) at a magnification capable of observing 10 to 50 crimp peaks of the constituting crimped fibers. However, when less than 10 crimp peaks could be confirmed within a visual field of 10 mm x 10 mm, the number of crimps of the fiber was set to 0. The number of peaks and valleys of the fiber per 25 mm were all counted, and the total divided by 2 was measured for 50 fibers, and the average value was taken as the number of crimps per 25 mm.

(2) Interval between fusion parts

The laminated stretchable nonwoven fabric was placed on black paper, the field of view of a square with a side of 1 cm was observed with a microscope, and the distance of the nearest fusion point was measured for all fusion points, and the average value was taken as the distance between the fusion parts. .

(3) extensibility

Using a tensile tester ("TENSILON" UCT-100 manufactured by Orientec), the laminated stretchable nonwoven fabric was stretched to an elongation of 100% in the MD direction and immediately contracted at the same rate to prepare a sample. In addition, the fixing interval at this time was 20 cm, the width was 5 cm, and the tensile rate was 20 cm/min.

The sample treated in this way was touched by 10 healthy general adults (15 male and female, 30 in total), and the texture of the surface was evaluated in the following three steps. For each nonwoven fabric, the average point of the evaluation results was calculated, and it was set as the feel of the nonwoven fabric.

5: There is no fluff or looseness on the surface, and it has a smooth texture

3: There is a small amount of fluff on the surface, there is mild looseness, and there is a feeling of a little unevenness.

1: There is clear fluff on the surface, there is looseness, and coarse irregularities are felt.

(4) Tactile

The laminated elastic nonwoven fabric was touched by healthy general adults (15 males and 30 females in total), and the texture of the surface was evaluated in the following three steps. For each nonwoven fabric, the average point of the evaluation results was calculated, and it was set as the feel of the nonwoven fabric.

5: Soft and smooth

3: Soft but not smooth, not soft but smooth

1: Neither soft nor smooth (hard, rubber touch).

[Example 1]

(Spunbond non-woven fabric layer)

Polypropylene (PP) and ethylene copolymerized polypropylene (coPP) are each melted in an extruder, the spinning temperature is 235° C., and as a side-by-side type composite fiber (mass ratio is 1:1), the hole diameter φ is 0.30 mm. From the rectangular nozzle, a single hole discharge rate was 0.6 g/min (for spunbond fibers, denoted as PP-coPP in Table 1). After the discharged yarn was cooled and solidified, it was pulled and stretched by compressed air at a pressure in the ejector of 0.10 MPa in a rectangular ejector, and collected on a moving net to obtain a nonwoven fibrous web. A spunbond nonwoven fabric layer in which crimping was strengthened was obtained by blowing hot air at 100° C. from an air nozzle to this nonwoven fibrous web (with respect to heat treatment, it is denoted as before Emb in Table 1). As for the characteristics of the crimped fibers constituting the obtained spunbond nonwoven fabric layer, the average single fiber diameter was 15.5 µm.

(elastomer layer)

Then, the polypropylene-based elastomer is melted in an extruder, the spinning temperature is 255° C., the hole diameter φ is 0.25 mm, and the single hole discharge rate is 0.12 g/min. After that, the air temperature is 275° C. and the air pressure is 0.18 By spraying under the conditions of MPa, a melt blown nonwoven fabric layer having a weight per unit area of 5 g/m ² was obtained. As for the characteristic of the obtained melt blown fiber, the average single fiber diameter was 2.0 micrometers.

(Lamination stretch nonwoven fabric)

By collecting the melt blown nonwoven fabric layer on the spunbond nonwoven fabric layer obtained above, and collecting the same spunbonded nonwoven fabric layer as the spunbond nonwoven fabric layer thereon, the spunbonded nonwoven fabric layer - the melt blown nonwoven fabric layer - the spunbonded nonwoven fabric layer A laminated fiber web of a three-layer structure (referred to as S/M/S in Table 1 for the laminated structure) was obtained.

The laminated fiber web thus obtained was placed on an upper roll with circular convex portions having an area of 1.44 mm ² having an area ratio of the web to an area of 16% at the same pitch in both directions of MD and CD (disposition of fusion points). regular) using a metal emboss roll, and an emboss roll having a pair of upper and lower heating mechanisms composed of a metal flat roll as the lower roll, the linear pressure is 300 N/cm, and the temperature at which the thermal bonding temperature is 125 ° C. was thermally bonded to obtain a laminated stretchable nonwoven fabric having a weight per unit area of 35 g/m ² . About the obtained laminated stretched nonwoven fabric, the number of crimps per 25 mm, the space|interval between fusion|fusion parts, extensibility, and feel were evaluated. A result is shown in Table 1.

[Example 2]

As the elastomer layer, a laminated stretchable nonwoven fabric was obtained in the same manner as in Example 1 except that a polypropylene-based elastomer film having a weight per unit area of 5 g/m ² was used. ). About the obtained laminated stretched nonwoven fabric, the number of crimps per 25 mm, the space|interval between fusion|fusion parts, extensibility, and feel were evaluated. A result is shown in Table 1.

[Example 3]

A laminated stretchable nonwoven fabric was obtained in the same manner as in Example 1, except that an embossing roll in which the convex portions were randomly arranged as in Fig. 1 (the arrangement of the fusion points was irregular) was used. About the obtained laminated stretchable nonwoven fabric, the number of crimps per 25 mm, the space|interval between fusion|fusion parts, extensibility, and feel were evaluated. A result is shown in Table 1.

[Example 4]

Laminated and stretched in the same manner as in Example 1, except that the area of the convex portion (circular shape) of the emboss roll is 400 times the size, and the pitch is 20 times the distance in either the line direction or the direction orthogonal to the line. A nonwoven fabric was obtained. About the obtained laminated stretchable nonwoven fabric, the number of crimps per 25 mm, the space|interval between fusion|fusion parts, extensibility, and feel were evaluated. A result is shown in Table 1.

[Example 5]

In the step of forming the spunbond nonwoven fabric layer, a laminated stretchable nonwoven fabric was obtained in the same manner as in Example 1 except that the temperature of the hot air sprayed after collecting the crimped fibers on the net was set to 80°C. About the obtained laminated stretchable nonwoven fabric, the number of crimps per 25 mm, the space|interval between fusion|fusion parts, extensibility, and feel were evaluated. A result is shown in Table 1.

[Comparative Example 1]

As the spunbond nonwoven fabric layer, only polypropylene (PP) is melted and spun in an extruder (for spunbond fibers, denoted as PP in Table 1), and in the forming process of the spunbonded nonwoven fabric layer, crimped fibers are A spunbond nonwoven fabric was obtained in the same manner as in Example 1, except that hot air was not blown before and after collecting in the spunbond nonwoven fabric to obtain a laminated stretchable nonwoven fabric (with respect to heat treatment, it is described as "no" in Table 1). About the obtained laminated stretchable nonwoven fabric, the number of crimps per 25 mm, the space|interval between fusion|fusion parts, extensibility, and feel were evaluated. A result is shown in Table 1.

[Comparative Example 2]

In the step of forming the spunbond nonwoven fabric layer, a laminated stretchable nonwoven fabric was obtained in the same manner as in Example 1 except that hot air was not blown before and after collecting the crimped fibers on the net. marked "). About the obtained laminated stretchable nonwoven fabric, the number of crimps per 25 mm, the space|interval between fusion|fusion parts, extensibility, and feel were evaluated. A result is shown in Table 1.

[Comparative Example 3]

Except having carried out after lamination and integration of hot air was carried out with an embossing roll, it carried out similarly to Example 1, and obtained the lamination|stacking elastic nonwoven fabric (with respect to heat treatment, in Table 1, it denotes after Emb). About the obtained laminated stretched nonwoven fabric, the number of crimps per 25 mm, the space|interval between fusion|fusion parts, extensibility, and feel were evaluated. A result is shown in Table 1.

[Comparative Example 4]

A stretchable nonwoven fabric was obtained in the same manner as in Example 1 except that the spunbond nonwoven fabric layer was not laminated, only the elastomer layer (melt blown nonwoven fabric layer), and that processing by an embossing roll was not performed (for the laminated structure, Table 1) denoted as M). About the obtained stretchable nonwoven fabric, extensibility and feel were evaluated. A result is shown in Table 1.

As shown in Table 1, it turns out that the nonwoven fabric of Examples 1-5 is excellent in extensibility and a feel. In particular, with respect to Example 1 and Example 2, it was to make extensibility and tactile feel compatible at a high level. On the other hand, for the nonwoven fabrics of Comparative Examples 1-3, the result was low extensibility. Moreover, about the nonwoven fabric of the comparative example 4, the result was low.

Although this invention was demonstrated with reference to specific embodiment, detailing, it is clear for those skilled in the art that various changes and correction can be added without deviating from the mind and range of this invention. This application is based on the Japanese patent application (Japanese Patent Application No. 2019-178658) of an application on September 30, 2019, The content is taken in here as a reference.

1: Projection part of emboss roll (convex part)
2: A dotted line indicating any part of a 10mm square on the surface of the embossing roll

Claims (9)

A laminated stretchable nonwoven fabric comprising a spunbonded nonwoven fabric layer and at least one elastomer layer laminated one by one, wherein the spunbonded nonwoven fabric layer comprises crimped fibers having a number of crimps of 50 or more per 25 mm. The laminated stretchable nonwoven fabric according to claim 1, wherein the elastomer layer is a melt blown nonwoven fabric layer. The laminated stretchable nonwoven fabric according to claim 1 or 2, wherein the laminated stretchable nonwoven fabric has a fusion portion of a regular pattern. The laminated stretchable nonwoven fabric according to claim 3, wherein an interval between adjacent fused portions is 50 µm or more and 20 mm or less. A sanitary material at least partly composed of the laminated stretchable nonwoven fabric according to any one of claims 1 to 4. When the melting point of the thermoplastic resin having the lowest melting temperature in the thermoplastic resin constituting the crimped fiber for the spunbond fiber including the crimped fiber is Tm, heat treatment is performed at a temperature of Tm-100°C or higher to form a spunbond nonwoven layer After the spunbond nonwoven fabric layer, at least one elastomer layer is laminated on the spunbonded nonwoven fabric layer, the manufacturing method of the laminated stretchable nonwoven fabric. The method for producing a laminated stretchable nonwoven fabric according to claim 6, wherein the elastomer layer is formed by a melt blow method. The method for producing a laminated stretchable nonwoven fabric according to claim 6 or 7, wherein the spunbond nonwoven fabric layer and the elastomer layer are laminated and then integrated so as to have a fusion portion having a regular pattern. The method for producing a laminated stretchable nonwoven fabric according to claim 8, wherein an interval between adjacent fusion-bonded portions of the crimped fibers constituting the spunbonded nonwoven fabric layer is set to 50 µm or more and 20 mm or less.

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