WO2021010357A1

WO2021010357A1 - Spun-bonded nonwoven fabric and laminated nonwoven fabric

Info

Publication number: WO2021010357A1
Application number: PCT/JP2020/027160
Authority: WO
Inventors: 健太郎梶原; 大士勝田; 結香西口; 義嗣船津
Original assignee: 東レ株式会社
Priority date: 2019-07-16
Filing date: 2020-07-10
Publication date: 2021-01-21
Also published as: KR20220034111A; JP7567478B2; TW202104707A; JPWO2021010357A1; TWI843872B

Abstract

The present invention relates to a spun-bonded nonwoven fabric that contains a long fiber. The long fiber contains a polymer A and a polymer B. The melting temperature of polymer B is higher than the melting temperature of polymer A by at least 30°C. The apparent density of the span-bonded nonwoven fabric is 0.050 g/cm³ or less.

Description

Spun-bonded non-woven fabric and laminated non-woven fabric

The present invention relates to a spunbonded non-woven fabric which is excellent in touch and is particularly suitable for use as a sanitary material.

In general, non-woven fabrics for sanitary materials such as disposable diapers and sanitary napkins are required to have excellent bulkiness and flexibility due to the texture when worn. In particular, a surface member that comes into direct contact with the skin is required to be bulky.

Conventionally, as a surface member of a sanitary material, a so-called air-through non-woven fabric, which is obtained by forming a sheet of short fibers by carding and then self-bonding by hot air treatment, is preferably used. The air-through non-woven fabric has a feature of being excellent in softness because it is excellent in bulkiness and flexibility, and is widely used, but it has a drawback that the manufacturing process is complicated and the production speed is slow.

On the other hand, spunbonded non-woven fabric is characterized by high productivity and low cost due to its manufacturing process. However, since the manufacturing process of the spunbonded nonwoven fabric is a manufacturing process in which the constituent long fibers tend to have a structure in which the constituent long fibers are oriented in the plane direction, it is difficult to obtain a spunbonded nonwoven fabric having excellent bulkiness and flexibility.

Therefore, studies are being conducted to improve the softness by imparting crimp to the long fibers to obtain high bulkiness.

For example, Patent Document 1 proposes a crimped composite fiber composed of two-component polymers having different melting temperatures of 10 ° C. or more.

Further, Patent Document 2 proposes a technique in which a web composed of a two-component polymer is heated, crimped, cooled, and then fused by hot air treatment.

Further, Patent Document 3 proposes a technique in which a web composed of a two-component polymer is first compacted and embossed, and then fused by hot air treatment.

Japanese Patent No. 5484564 Japan Special Table 2005-514528 Japanese Patent Application Laid-Open No. 2018-024965

According to the technique disclosed in Patent Document 1, the effect of improving the bulkiness can be obtained by crimping during spinning. However, sufficient bulk could not be obtained in order to fix the shape by embossing by heat fusion while compressing.

According to the technique disclosed in Patent Document 2, the bulkiness is improved by adopting the occurrence of crimping by heat treatment after spinning and the subsequent fusion with hot air. However, since it is necessary to perform the heat treatment twice, there is a problem that the productivity is inferior and the bulkiness is not sufficient.

According to the technique disclosed in Patent Document 3, the bulkiness is improved by crimping during spinning. However, after that, it is a complicated process in which consolidation treatment is performed and then fusion is performed by embossing or hot air treatment, and the bulkiness is reduced by the consolidation treatment, and there is also a problem in productivity.

As described above, conventionally, a spunbonded non-woven fabric having excellent productivity and stability and having a high bulkiness that is satisfactory for use as a sanitary material has not been obtained.

Therefore, an object of the present invention has been made in view of the above circumstances, and is a spunbond having excellent productivity and stability, and having a high level of bulkiness that is satisfactory for use as a sanitary material. It is to provide a non-woven fabric.

As a result of diligent studies to achieve the above object, the present inventors have sufficient long fibers in the step of developing crimps and fusing long fibers with each other by adopting a specific polymer combination. Since the rigidity can be maintained, it has been found that a spunbonded non-woven fabric having high bulkiness can be obtained by a simple process as compared with the conventional manufacturing method.

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

<1> A spunbonded non-woven fabric containing long fibers.
The long fibers contain polymer A and polymer B and contain
The melting temperature of the polymer B is 30 ° C. or higher higher than the melting temperature of the polymer A.
A spunbonded non-woven fabric having an apparent density of 0.050 g / cm ³ or less.
<2> The spunbonded nonwoven fabric according to <1>, wherein the polymer A is a polyolefin-based polymer and the polymer B is a polyester-based polymer.
<3> The spunbonded nonwoven fabric according to <1> or <2>, wherein the long fibers are side-by-side fibers.
<4> A plurality of connecting portions for connecting any two long fibers of the long fibers are provided.
The spunbonded nonwoven fabric according to any one of <1> to <3>, wherein at least one of the connecting portions contains the polymer A.
<5> The spunbonded nonwoven fabric according to any one of <1> to <4>, wherein the long fibers have a dumbbell-shaped cross section.
<6> A laminated non-woven fabric in which at least the surface layer is the spunbonded non-woven fabric according to any one of <1> to <5>.

According to the present invention, it is possible to obtain a spunbonded nonwoven fabric having excellent productivity and stability and high bulkiness. In particular, the spunbonded non-woven fabric of the present invention is characterized by having excellent productivity and an excellent soft feeling obtained from high bulkiness, and therefore, paper diapers, sanitary napkins, etc., which are strongly required to have both high productivity and feel. It can be suitably used for sanitary materials of.

FIG. 1 is a cross-sectional view of an embodiment of a long fiber used in the spunbonded nonwoven fabric of the present invention. The long fibers of FIG. 1 are side-by-side fibers having a dumbbell-shaped cross section.

The spunbonded nonwoven fabric of the present invention contains long fibers containing polymer A and polymer B, the melting temperature of polymer B is 30 ° C. or higher higher than the melting temperature of polymer A, and the apparent density of the spunbonded nonwoven fabric is 0. It is 05 g / cm ³ or less.
The details will be described below.

[Polymer A and Polymer B]
As the polymer A and the polymer B, for example, a thermoplastic resin can be used.
Examples of thermoplastic resins include aromatic polyester-based polymers such as "polyethylene terephthalate, polytrimethylene terephthalate, polybutylene terephthalate, polyhexamethylene terephthalate" and their copolymers, "polylactic acid, polyethylene succinate, polybutylene succinate". Aliper polyester polymers such as "Nate, polybutylene succinate adipate, polyhydroxybutyrate-polyhydroxyvariate copolymer, polycaprolactone" and their copolymers, "Polymer 6, Polyamide 66, Polyamide 610, Polyamide 10, Aliper polyamide polymers such as polyamide 12, polyamide 6-12 and their copolymers, polyolefin polymers such as "polypropylene, polyethylene, polybutene, polymethylpentene" and their copolymers, ethylene units from 25 mol% Examples thereof include water-insoluble ethylene-vinyl alcohol copolymer-based polymers containing 70 mol%, polystyrene-based, polydiene-based, chlorine-based, polyolefin-based, polyester-based, polyurethane-based, polyamide-based, and fluorine-based elastomer-based polymers. At least two types can be selected from these and used as the polymer A and the polymer B.

Here, as the polymer A to be a low melting temperature component, it is preferable to select a polymer having a relatively low melting temperature among the above-mentioned thermoplastic resins, and a polyolefin-based polymer such as "polypropylene, polyethylene, polybutene, polymethylpentene" is used. It is preferable to use a polymer and a copolymer thereof.

On the other hand, as the polymer B having a high melting temperature component, aromatic polyester-based polymers such as "polyethylene terephthalate, polytrimethylene terephthalate, polybutylene terephthalate, polyhexamethylene terephthalate" and their copolymers, "polylactic acid, polyethylene succi" It is preferable to use an aliphatic polyester polymer such as "Nate, polybutylene succinate, polybutylene succinate adipate, polyhydroxybutyrate-polyhydroxyvariate copolymer, polycaprolactone" and its copolymer.

In particular, since it is easy to obtain a spunbonded non-woven fabric having excellent strength and excellent fluff resistance, the polymer B is an aromatic polyester such as "polyethylene terephthalate, polytrimethylene terephthalate, polybutylene terephthalate, polyhexamethylene terephthalate". It is more preferable to use a system.

Here, as described above, the melting temperature of the polymer B is 30 ° C. or more higher than the melting temperature of the polymer A. The difference between the melting temperature of the polymer B and the melting temperature of the polymer A is preferably 60 ° C. or higher, more preferably 80 ° C. or higher. By doing so, it is possible to obtain a spunbonded nonwoven fabric having bulkiness suitable for use as a sanitary material.

The melting temperature of the polymer A and the melting temperature of the polymer B used in the present invention are preferably 100 ° C. or higher and 300 ° C. or lower, more preferably 120 ° C. or higher and 280 ° C. or lower. By setting the melting temperature to 100 ° C. or higher, it becomes easy to obtain heat resistance that can withstand practical use.

Further, the melting temperature of the polymer A and the melting temperature of the polymer B are preferably 300 ° C. or lower, more preferably 280 ° C. or lower. By setting the melting temperature to 300 ° C. or lower, it becomes easier to cool the threads discharged from the mouthpiece, fusion of fibers is suppressed, and the obtained spunbonded non-woven fabric has few defects.

The melting temperature in the present invention is the peak top of the endothermic peak measured at a heating rate of 16 ° C./min under a nitrogen atmosphere using a differential scanning calorimeter (for example, "DSCQ2000" manufactured by TA Instruments). Refers to temperature.

Further, the polymers A and B include antioxidants, weather stabilizers, light stabilizers, antistatic agents, antifoaming agents, antiblocking agents, nucleating agents, pigments and the like, as long as the effects of the present invention are not impaired. Additives or other polymers can be added as needed.

[Long fiber]
The long fibers contained in the spunbonded nonwoven fabric of the present invention preferably contain the above-mentioned polymer A and polymer B, and are long fibers composed of the polymer A and the polymer B. In this long fiber, the polymer A and the polymer B form a region respectively, and the polymer A and the polymer B are adhered with an interface. The long fibers can be selected from composite fibers in the form of side-by-side fibers, eccentric core sheath fibers and the like.

Above all, from the viewpoint of obtaining a high degree of crimping, it is preferable to use side-by-side fibers as the long fibers because it is easy to control the positions and amounts of both polymers. In particular, it is more preferable to use dumbbell-shaped side-by-side fibers as shown in FIG. 1 because it is easy to impart fine crimps.

On the other hand, when there is a difference between the melt viscosity of the polymer A and the melt viscosity of the polymer B, it is also a preferable embodiment to use the eccentric core sheath fiber as the long fiber from the viewpoint of spinnability. The difference in melt viscosity referred to in the present invention means that the shear rate is zero from the viscosity curve measured at the spinning temperature using a dynamic viscoelasticity evaluation device (for example, "Rheosol-G3000" manufactured by UBM). It means that one is 10% or more larger than the other in the viscosity extrapolated to.

[Spanbond non-woven fabric]
The spunbonded non-woven fabric of the present invention has a tensile strength per unit basis weight of 0.3 (N / 5 cm) / (g / m ² ) or more and 10.0 (N / 5 cm) / (g / m ² ) or less. Is preferable.

When the tensile strength per unit basis weight is 0.3 (N / 5 cm) / (g / m ² ) or more, it can withstand the process passability when manufacturing disposable diapers and the use as a product. .. The tensile strength per unit basis weight is more preferably 0.4 (N / 5 cm) / (g / m ² ) or more, and further preferably 0.5 (N / 5 cm) / (g / m ² ) or more.

On the other hand, when the tensile strength per unit basis weight is 10.0 (N / 5 cm) / (g / m ² ) or less, the flexibility of the spunbonded non-woven fabric can be further combined. The tensile strength per unit basis weight is more preferably 8.0 (N / 5 cm) / (g / m ² ) or less, and further preferably 6.0 (N / 5 cm) / (g / m ² ) or less.

The tensile strength per unit basis weight can be controlled by the above-mentioned thermoplastic resin, additives, fiber diameter, and / or the spinning speed, basis weight, apparent density, and bonding method described later.

The tensile strength per unit of the spunbonded non-woven fabric in the present invention is "6.3. Tensile strength and elongation (ISO method)" of JIS L1913: 2010 "General non-woven fabric test method", "6.3.1 Standard time". In a tensile test with a gripping interval of at least 5 cm, the average tensile strength (strength when the sample broke) in two orthogonal directions was divided by the scale measured by the method described later. The value.

The spunbonded nonwoven fabric of the present invention preferably has a thickness of 0.05 mm or more and 1.50 mm or less.

When the thickness is 0.05 mm or more, the spunbonded non-woven fabric has an appropriate cushioning property. The thickness is more preferably 0.07 mm or more, still more preferably 0.09 mm or more.

On the other hand, when the thickness is 1.50 mm or less, the spunbonded non-woven fabric has excellent bending flexibility. The thickness is more preferably 0.14 mm or less, still more preferably 0.13 mm or less.

The thickness of the spunbonded nonwoven fabric in the present invention is not particularly limited, but refers to, for example, the thickness under no load measured by a shape measuring machine (for example, "VR3050" manufactured by KEYENCE CORPORATION).

The spunbonded nonwoven fabric of the present invention preferably has a basis weight of 10 g / m ² or more and 100 g / m ² or less.

When the basis weight of the spunbonded nonwoven fabric is 10 g / m ² or more, the spunbonded nonwoven fabric can be easily made into a thickness suitable for sanitary material use, and can be a spunbonded nonwoven fabric having mechanical strength that can be put into practical use.

On the other hand, when the basis weight of the spunbonded non-woven fabric is 100 g / m ² or less, the spunbonded non-woven fabric having excellent breathability and flexibility can be obtained. The basis weight of the spunbonded non-woven fabric is more preferably 80 g / m ² or less, still more preferably 60 g / m ² or less.

The texture (g / m ² ) of the spunbonded non-woven fabric in the present invention is based on "6.2 Mass per unit area" of JIS L1913: 2010, and a 20 cm × 25 cm test piece is used per 1 m of sample width. Three sheets are collected, each mass (g) in the standard state is weighed, and the mass per 1 m ² calculated from the average value is used.

The spunbonded nonwoven fabric of the present invention has an apparent density of 0.050 g / cm ³ or less.

When the apparent density of the spunbonded non-woven fabric is 0.050 g / cm ³ or less, it is easy to obtain the spunbonded non-woven fabric having excellent breathability and flexibility, and it is easy to feel the high bulkiness. The apparent density of the spunbonded non-woven fabric is preferably 0.045 g / cm ³ or less, more preferably 0.040 g / cm ³ or less.

The lower limit of the apparent density of the spunbonded non-woven fabric is not particularly limited, but for example, when it is 0.01 g / cm ³ or more, it is easy to obtain morphological stability that can be put into practical use.

The apparent density of the spunbonded nonwoven fabric in the present invention is a value obtained by dividing the basis weight by the thickness.

The spunbonded nonwoven fabric of the present invention has a plurality of connecting portions for connecting any two long fibers of the long fibers, and at least one of the connecting portions contains the polymer A, resulting in high morphological stability. It is preferable because it can be obtained.

The state in which the connecting portion contains the polymer A means a state in which a certain long fiber and a long fiber adjacent thereto are partially fused by the polymer A, and the long fibers are continuously fused to each other. It refers to a state in which there is substantially no portion that is fused to form a film having a certain width.

[Manufacturing method of spunbonded non-woven fabric]
Next, a preferred embodiment of the method for producing a spunbonded nonwoven fabric of the present invention will be specifically described.
In the spunbond method for producing a spunbonded non-woven fabric, a thermoplastic resin (polymer A, polymer B) as a raw material is melted, spun from a spinneret, and cooled and solidified to obtain a yarn. Then, the obtained yarn is towed and stretched by an ejector to obtain long fibers. Then, the obtained long fibers are collected on a moving net to form a non-woven fiber web, and then a spunbonded non-woven fabric is obtained through a step of heat-bonding the non-woven fiber web.

As the shape of the spinneret and ejector used, various shapes such as a round shape and a rectangular shape can be adopted. Among them, it is preferable to use a combination of a rectangular base and a rectangular ejector from the viewpoint that the amount of compressed air used is relatively small and the yarns are less likely to be fused or scratched.

To exemplify a preferable method for producing long fibers used in the present invention, polymer A and polymer B are melted and weighed in different extruders and supplied to a side-by-side or eccentric core-sheath type composite spinneret to supply long fibers. Spin as. At this time, if the polymer A, which is a low melting temperature component, is exposed on the surface, it is preferable because the long fibers are easily bonded to each other in the heat bonding step described later.

In the present invention, the spinning temperature is preferably (melting temperature of the raw material thermoplastic resin + 10 ° C.) or more (melting temperature of the raw material thermoplastic resin + 100 ° C.) or less. This is because by setting the spinning temperature within the above range, a stable molten state can be obtained and excellent spinning stability can be obtained.

The spun long fiber yarn is cooled next, and as a method of cooling the spun yarn, for example, a method of forcibly blowing cold air onto the yarn, an atmospheric temperature around the yarn, etc. A method of naturally cooling the yarn, a method of adjusting the distance between the spinneret and the ejector, and the like, or a method in which these methods are combined can be adopted. Further, the cooling conditions can be appropriately adjusted in consideration of the discharge amount per single hole of the spinneret, the spinning temperature, the atmospheric temperature and the like.

Next, the cooled and solidified yarn is towed and stretched by the compressed air injected from the ejector.

The spinning speed is preferably 2000 m / min or more, more preferably 3000 m / min or more, and further preferably 4000 m / min or more. By setting the spinning speed to 2000 m / min or more, high productivity can be obtained, orientation and crystallization of fibers can be advanced, and high-strength long fibers can be obtained.

Subsequently, the obtained long fibers are collected on a moving net and made into a non-woven fiber web. In the present invention, since the fibers are drawn at a high spinning speed, the fibers emitted from the ejector are collected in the net in a state controlled by a high-speed air flow, and the fibers are less entangled and highly uniform non-woven fibers. You can get the web.

Such a non-woven fiber web can be made into a spunbonded non-woven fabric by using only one non-woven fiber web, but a plurality of spinning facilities are arranged in the process direction and a plurality of webs are stacked to obtain a spunbonded non-woven fabric. This is also a preferable embodiment in that the productivity can be increased.

At this time, the raw materials and process conditions can be changed for each non-woven fiber web. Further, in order to obtain a laminated nonwoven fabric, it is also one of the preferable embodiments to laminate layers of the melt blow nonwoven fabric. In the present invention, these laminates are also collectively referred to as "non-woven fiber web".

Subsequently, the intended non-woven fabric or laminated non-woven fabric can be obtained by integrating the obtained non-woven fiber webs by heat bonding.

Examples of the method of integrating the non-woven fiber webs by heat bonding include a method of heat bonding with heated air, a method of heat bonding with a roll, and the like.

The rolls used for heat bonding include a heat embossed roll with engraving (unevenness) on the upper and lower roll surfaces, one roll with a flat (smooth) roll surface, and engraving (unevenness) on the roll surface. Examples thereof include a thermal embossing roll composed of a combination with the other roll, and a thermal calendar roll composed of a combination of a pair of upper and lower flat (smooth) rolls.

In the present invention, in order to obtain a high bulkiness, a method of heat-bonding with heated air without pressurization by the roll is preferable. In the method of heat-bonding with heated air, it is preferable to heat the air to a temperature between the melting temperature of the polymer A and the melting temperature of the polymer B because the shape can be fixed while maintaining the thickness.

[Laminated non-woven fabric]
The laminated nonwoven fabric of the present invention has at least a surface layer of the spunbonded nonwoven fabric of the present invention.

The laminated non-woven fabric of the present invention is preferably a laminated non-woven fabric in which the spunbonded non-woven fabric of the present invention is used as a surface layer and melt-blown non-woven fabric is laminated as an inner layer. With such a configuration, as a laminated non-woven fabric for sanitary materials, it is possible to impart a level of water resistance particularly required for waist gather applications.

In a preferred form of the laminated non-woven fabric of the present invention, it is sufficient that the spunbonded non-woven fabric layer (S) is arranged on the surface layer and the melt-blown non-woven fabric layer (M) is arranged on the inner layer. As for the number and combination, any configuration can be adopted depending on the purpose, such as SMS, SMMS, SMSMS, and SMSMS.

The basis weight of the laminated non-woven fabric of the present invention is preferably 10 g / m ² or more and 100 g / m ² or less.

By setting the basis weight of the laminated nonwoven fabric to 10 g / m ² or more, it is possible to obtain a laminated nonwoven fabric having mechanical strength that can be put into practical use. The basis weight of the laminated non-woven fabric is more preferably 13 g / m ² or more, still more preferably 15 g / m ² or more.

On the other hand, by setting the basis weight of the laminated non-woven fabric to 100 g / m ² or less, it is possible to obtain a laminated non-woven fabric having appropriate flexibility suitable for use as a non-woven fabric for sanitary materials. The basis weight of the laminated non-woven fabric is more preferably 50 g / m ² or less, still more preferably 35 g / m ² or less.

The texture (g / m ² ) of the laminated non-woven fabric in the present invention is based on "6.2 Mass per unit area" of JIS L1913: 2010, and a test piece of 20 cm x 25 cm is used as a sample width of 3 per 1 m. Sheets are taken, each mass (g) in the standard state is weighed, and the mass per 1 m ² calculated from the average value is used.

As described above, the spunbonded non-woven fabric and the laminated non-woven fabric of the present invention are characterized by having excellent productivity and an excellent soft feeling obtained from high bulkiness, and therefore, paper diapers that are strongly required to have both high productivity and touch comfort. It can be suitably used for sanitary materials such as sanitary napkins and sanitary napkins. The soft feeling referred to in the present invention is a feeling of touch that is smooth when the surface is patted and that an appropriate elasticity is felt in the thickness direction.

Next, the present invention will be specifically described based on Examples. However, the present invention is not limited to these examples. In addition, in the measurement of each physical property, if there is no particular description, the measurement is performed based on the above method. However, the present invention is not limited to the description of these examples.

(Observation, measurement)
The following observations or measurements were made on long fibers, polymers or spunbonded non-woven fabrics. The results are shown in Table 1.

(1) Long fiber cross section Ten small piece samples were randomly collected from the obtained long fibers, and the cross section was observed with a microscope to confirm the shape.

(2) Melting temperature The melting temperature of polymer A and the melting temperature of polymer B were measured using a differential scanning calorimeter [“DSCQ2000” manufactured by TA Instruments]. Then, the melting temperature difference (° C.) was calculated by the following formula.
Melting temperature difference (° C) = melting temperature of polymer B-melting temperature of polymer A

(3) Metsuke Based on "6.2 Mass per unit area" of JIS L1913: 2010, 3 test pieces of 20 cm x 25 cm were collected per 1 m of width of the obtained spunbonded non-woven fabric, and each of them in the standard state. The mass (g) was weighed, and the mass per 1 m ² calculated from the average value was used as the basis weight.

(4) Thickness The thickness of the obtained spunbonded non-woven fabric under no load was measured with a shape measuring machine (“VR3050” manufactured by KEYENCE CORPORATION).

(5) Apparent density Based on "6.2 Mass per unit area" of JIS L1913: 2010, 3 test pieces of 20 cm x 25 cm were collected per 1 m of width of the obtained spunbonded non-woven fabric, and each in the standard state. The mass (g) was measured, and the mass per 1 m ² calculated from the average value was measured with a shape measuring machine (“VR3050” manufactured by Keyence Co., Ltd.). The value obtained by dividing the obtained value by the thickness of the spunbonded non-woven fabric under no load was taken as the apparent density.

(6) Tensile strength per unit scale JIS L1913: 2010 "6.3 Tensile strength and elongation (ISO method)" of "General non-woven fabric test method""6.3.1 Standard time" was carried out. By a tensile test with a gripping interval of at least 5 cm, the value obtained by dividing the average of the tensile strengths (strength when the spunbonded non-woven fabric was broken) in two orthogonal directions by the grain was taken as the tensile strength per unit grain.

(7) Soft feeling (class)
Ten arbitrarily selected spunbonded non-woven fabrics were touched by hand, and each spunbonded non-woven fabric was evaluated according to the following criteria. The average score of the evaluation results for each spunbonded non-woven fabric was taken as the soft feeling of the spunbonded non-woven fabric.

5: It was very comfortable and I liked it very softly (it was smooth to the touch when stroking the surface, and I felt moderate elasticity in the thickness direction).
4: It was a little comfortable and I liked the soft feeling.
3: It was not unpleasant but not comfortable, and it was a soft feeling that I did not dislike but did not like.
2: It was a little unpleasant and a little disliked soft feeling.
1: It was very unpleasant and I hated it very softly (I felt a catch when stroking the surface, and a strong repulsion when I pressed it, or it was worn out).

(Example 1)
Polyethylene (PE) as polymer A and polyethylene terephthalate (PET) as polymer B were melted by an extruder and molded into side-by-side composite fibers (mass ratio 1: 1) at a spinning temperature of 290 ° C. A single-hole discharge rate of 0.6 g / min was spun from a rectangular base having a hole having a hole diameter of 0.30 mm.

The spun yarn was cooled and solidified, and then towed and stretched by compressed air having a pressure at the ejector of 0.10 MPa in a rectangular ejector, and collected on a moving net to obtain long fibers. Subsequently, the obtained long fibers were heated with hot air at 150 ° C. and heat-bonded to obtain a spunbonded nonwoven fabric having a basis weight of 20 g / m ² .

(Example 2)
A spunbonded nonwoven fabric was obtained in the same manner as in Example 1 except that the eccentric core sheath type composite fiber was molded instead of molding the side-by-side type composite fiber.

(Example 3)
A spunbonded non-woven fabric was obtained in the same manner as in Example 1 except that the spinning was carried out under the following conditions.
Hole shape in the rectangular base: Circles arranged on both sides of the rectangle Diameter of circles arranged on both sides of the rectangle φ: 0.30 mm
Center distance between two circles placed on both sides of the rectangle: 0.8 mm
Single hole discharge rate: 0.6 g / min

(Comparative Example 1)
Polypropylene (PP) is melted by an extruder, molded into a single component fiber at a spinning temperature of 230 ° C., and a single hole discharge rate of 0.6 g / g from a rectangular mouthpiece having a hole with a hole diameter of 0.30 mm. Spinned in minutes.

The spun yarn was cooled and solidified, and then towed and stretched by compressed air having a pressure at the ejector of 0.10 MPa in a rectangular ejector, and collected on a moving net to obtain long fibers. Subsequently, the obtained long fibers are heat-bonded (linear pressure: 50 N / cm, heat-bonding temperature: 130 ° C.) with a pair of upper and lower thermal embossing rolls composed of an upper roll and a lower roll, and have a basis weight of 20 g / m ² . A spunbonded non-woven fabric was obtained.

At this time, for the upper roll, an embossed roll made of metal and having a polka dot pattern engraved at a depth of 0.5 mm was used with an adhesive area ratio of 16%. A metal flat roll was used as the lower roll.

(Comparative Example 2)
Copolymerized PP as polymer A and PP as polymer B are melted by an extruder and formed into side-by-side composite fibers (mass ratio 1: 1) at a spinning temperature of 230 ° C., and the pore diameter φ is 0. A spunbonded non-woven fabric was obtained in the same manner as in Comparative Example 1 except that a single-hole discharge rate of 0.6 g / min was spun from a rectangular base having a hole of .30 mm.

(Comparative Example 3)
A spunbonded nonwoven fabric was obtained in the same manner as in Comparative Example 2 except that PE was used as the polymer A.

(Comparative Example 4)
A spunbonded nonwoven fabric was obtained in the same manner as in Comparative Example 1 except that the obtained long fibers were heated with hot air at 150 ° C. and heat-bonded.

As shown in Table 1, the spunbonded non-woven fabrics of Examples 1 to 3 had a sensory evaluation result of 4.0 to 5.0, which was an excellent result of a soft feeling. Therefore, it was found that the spunbonded nonwoven fabrics of Examples 1 to 3 have a high level of bulkiness that is satisfactory for use as a sanitary material.

Further, the spunbonded non-woven fabrics of Examples 1 to 3 are superior in productivity as compared with the air-through non-woven fabric. Further, the spunbonded nonwoven fabrics of Examples 1 to 3 are fused and have a high level of bulkiness, and thus are excellent in morphological stability.

On the other hand, Comparative Examples 1 to 4 showed that the sensory evaluation result was 2.0 or less, which was inferior to the soft feeling.

Although the present invention has been described in detail and with reference to specific embodiments, it will be apparent to those skilled in the art that various changes and modifications can be made without departing from the spirit and scope of the invention. This application is based on a Japanese patent application filed on July 16, 2019 (Japanese Patent Application No. 2019-130840), the contents of which are incorporated herein by reference.

A polymer B polymer

Claims

A spunbonded non-woven fabric containing long fibers.
The long fibers contain polymer A and polymer B and contain
The melting temperature of the polymer B is 30 ° C. or higher higher than the melting temperature of the polymer A.
A spunbonded non-woven fabric having an apparent density of 0.050 g / cm 3 or less.
The spunbonded nonwoven fabric according to claim 1, wherein the polymer A is a polyolefin-based polymer and the polymer B is a polyester-based polymer.
The spunbonded nonwoven fabric according to claim 1 or 2, wherein the long fibers are side-by-side fibers.
It has a plurality of connecting portions for connecting any two long fibers of the long fibers.
The spunbonded nonwoven fabric according to any one of claims 1 to 3, wherein at least one of the connecting portions contains the polymer A.
The spunbonded nonwoven fabric according to any one of claims 1 to 4, wherein the long fibers have a dumbbell-shaped cross section.
A laminated non-woven fabric in which at least the surface layer is the spunbonded non-woven fabric according to any one of claims 1 to 5.