KR20210058853A - Spunbond nonwoven - Google Patents

Abstract

The invention, and the bending property is returned 0.2㎝ than ^-1 1.0㎝ ^-1 or less, also relates to a spun-bonded nonwoven fabric or less 100㎫ tensile elastic modulus is more than 5㎫.

Description

Spunbond nonwoven

The present invention relates to a spunbond nonwoven fabric having excellent tactile feel and particularly suitable for use as a hygiene material.

In general, since nonwoven fabrics used for hygiene materials such as paper diapers and sanitary napkins are discarded with a small number of uses, in order to be widely used, they need to be inexpensive, and high productivity has been strongly demanded. Therefore, a spunbond nonwoven fabric manufactured by combining a spunbond method, which is a method of forming a web having excellent productivity, and an emboss method, which is a method of bonding fibers having excellent productivity, is widely used.

On the other hand, since hygiene materials are often in direct contact with delicate skin such as infants, excellent tactile feel is strongly required, and for example, a tactile feel similar to that of underwear using a general woven fabric is required, but such tactile spunbond nonwoven fabric Cannot be realized, and various reviews are being conducted to improve the tactile feel.

For example, Patent Document 1 proposes a spunbond nonwoven fabric comprising a polyolefin fiber to which a fatty acid amide compound has been added.

Japanese Patent Publication No. 2018-119247

According to the technique disclosed in Patent Document 1, since the fatty acid amide compound softens the raw material polymer as a lubricant, the stiffness of the spunbond nonwoven fabric can be reduced (flexibly). However, as a result of the panel test by the present inventors, it was found that the preferred tactile feel does not simply indicate that the stiffness is low, and the tactile feel that is very familiar to the hand is also particularly pleasing. Accordingly, an object of the present invention has been made in view of the above circumstances, and is to provide a spunbond nonwoven fabric having a very familiar hand feel (hereinafter referred to as an excellent soft feeling).

The inventors of the present invention have repeatedly studied intensively in order to achieve the above object, and as a result, have found that when having a specific bending recovery property and a specific tensile modulus, a feeling that feels particularly pleasing is obtained, and by controlling their physical property values, the hand The knowledge that an excellent soft feeling can be obtained that is very familiar with is obtained.

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

Spun-bonded nonwoven fabric according to an embodiment of the present invention is a spun-bonded nonwoven fabric composed of fibers containing a thermoplastic resin, the flexural return of the said spun bond nonwoven fabric and more than 0.2㎝ ^-1 1.0㎝ ^-1 or less, and the spun-bonded non-woven fabric The tensile modulus of is 5 MPa or more and 100 MPa or less.

According to a preferred embodiment of the spunbond nonwoven fabric of the present invention, the bending stiffness of the spunbond nonwoven fabric is 10 μN·cm 2 /cm or more and 300 μN·cm 2 /cm or less.

According to a preferred embodiment of the spunbond nonwoven fabric of the present invention, the apparent density of the spunbond nonwoven fabric described above is 0.01 g/cm 3 or more and 0.30 g/cm 3 or less.

According to the present invention, a spunbond nonwoven fabric having an excellent soft feeling can be obtained. Particularly, the spunbond nonwoven fabric of the present invention can be suitably used for hygiene materials such as paper diapers and sanitary napkins, which strongly require high productivity and compatibility of the touch from the characteristics of being very familiar to the hand and having an excellent soft feeling.

Spun-bonded nonwoven fabric of the present invention is a spun-bonded nonwoven fabric composed of fibers containing a thermoplastic resin, and the bending property is returned 0.2㎝ than ^-1 1.0㎝ ^-1 or less, and is less than the tensile elastic modulus is more than 5㎫ 100㎫. Below, this detail is demonstrated.

[Thermoplastic resin]

The thermoplastic resin used in the spunbond nonwoven fabric of the present invention is not particularly limited, but for example, aromatic polyester polymers such as polyethylene terephthalate, polytrimethylene terephthalate, polybutylene terephthalate, and polyhexamethylene terephthalate, and Aliphatic polyester-based polymers such as copolymers thereof, polylactic acid, polyethylene succinate, polybutylene succinate, polybutylene succinate adipate, polyhydroxybutyrate-polyhydroxyvalerate copolymer, and polycaprolactone, and the like Aliphatic polyamide-based polymers such as copolymer, polyamide 6, polyamide 66, polyamide 610, polyamide 10, polyamide 12, and polyamide 6-12, and copolymers thereof, polypropylene, polyethylene, polybutene, polymethyl Polyolefin-based polymers such as pentene and their copolymers, 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, poly At least one type of urethane-based, polyamide-based, and fluorine-based elastomer-based polymer can be selected and used.

Here, the polymer in which a lubricant is added to the polyolefin resin is a preferred embodiment in that it is easy to obtain low bending stiffness, low bending recovery, and an appropriate tensile modulus at the same time. Examples of such a polymer include polypropylene to which a fatty acid amide compound has been added.

Examples of the fatty acid amide compound include a fatty acid monoamide compound, a fatty acid diamide compound, a saturated fatty acid monoamide compound, and an unsaturated fatty acid diamide compound. Specifically, lauric acid amide, myristic acid amide, palmitic acid amide, stearic acid amide, ethylene bis stearic acid amide, behenic acid amide, oleic acid amide, erucic acid amide, montanic acid amide, N,N'- Methylene-bis-lauric acid amide, N,N'-methylene-bis-myristic acid amide, N,N'-methylene-bis-palmitic acid amide, N,N'-methylene-bis-behenic acid amide, N,N'-methylene-bis-oleic acid amide, N,N'-methylene-bis-erucic acid amide, N,N'-ethylene-bis-oleic acid amide, N,N'-ethylene-bis-erucic acid Amides, etc. are mentioned, and it is also a preferable aspect to use these in combination of multiple types.

Further, a polymer obtained by softening a polyester-based polymer by copolymerization or blending with another polymer is preferable because it is easy to achieve both low bending stiffness and low bending recovery. As an example of such a polymer, in particular, copolymerization or polymer blending of polyethylene glycol with a polyester resin is easy to obtain at the same time low bending stiffness, low bending recovery, and adequate tensile modulus depending on the molecular weight or copolymerization ratio of polyethylene glycol. It is a particularly preferred aspect.

In addition, additives such as antioxidants, weather stabilizers, light stabilizers, antistatic agents, antifogging agents, antiblocking agents, nucleating agents and pigments, or other polymers, as required, to these thermoplastic resins, as long as the effects of the present invention are not impaired. Can be added.

[fiber]

The fibers constituting the spunbond nonwoven fabric of the present invention preferably have a single fiber diameter of 5 µm or more and 30 µm or less. This is because high uniformity and flexibility are obtained when the single fiber fiber diameter is 30 µm or less, and a reliable touch is obtained when it is 5 µm or more. The single fiber fiber diameter is more preferably 25 µm or less, and even more preferably 20 µm or less. Moreover, 7 micrometers or more are more preferable, and 9 micrometers or more are still more preferable.

In addition, the single fiber fiber diameter referred to in the present invention refers to a surface photograph of 500 to 1000 times with a microscope, measuring the width of a total of 100 randomly selected fibers, and calculating the single fiber diameter (µm) from the arithmetic average value. This is the calculated value.

[Spunbond nonwoven fabric]

Spun-bonded nonwoven fabric of the present invention is the flexural return St. 0.2㎝ ^-1 or more 1.0㎝ ^-1 or less. By bending back St. 1.0㎝ ^-1 or less, or more by the complex attached to the hand feeling at the time of bending back is obtained, 0.2㎝ ^-1, is obtained a suitable return difficulty is because the natural texture. Bending back a castle 0.8㎝ ^-1 or less are preferable and more preferably 0.6㎝ ^-1 or less, and. In addition, the 0.3㎝ ^-1 or more is preferable, and 0.4㎝ ^-1 or more is more preferable.

The bending return property can be controlled by the above-described thermoplastic resin, additives, fiber diameter, and/or spinning speed described later, weight per unit area, apparent density, bonding method, and the like.

The bending resilience of the spunbond nonwoven fabric in the present invention refers to bending stiffness (B) and bending hysteresis (2HB) in two orthogonal directions by a bending tester (for example, ``KES-FB2'', manufactured by Katotech). It is a value measured and calculated|required by the following formula.

Bending stiffness = (B in direction 1 + B in direction 2)/2

Bending hysteresis = (2HB in direction 1 + 2HB in direction 2)/2

·Bending return property = bending hysteresis/bending stiffness

It is preferable that the spunbond nonwoven fabric of the present invention has a bending stiffness of 10 μN·cm 2 /cm or more and 300 μN·cm 2 /cm or less. This is because when the bending stiffness is 300 µN·cm 2 /cm or less, it is easy to bend and a flexible touch is obtained, and when it is 10 µN·cm 2 /cm or more, an appropriate bending reaction is obtained. This bending stiffness is more preferably 250 µN·cm 2 /cm or less, and even more preferably 200 µN·cm 2 /cm or less. Moreover, 20 µN·cm 2 /cm or more is more preferable, and 30 µN·cm 2 /cm or more is still more preferable. The bending stiffness can be controlled by the above-described thermoplastic resin, additives, fiber diameter, and/or spinning speed described later, weight per unit area, apparent density, bonding method, and the like.

The bending stiffness of the spunbonded nonwoven fabric in the present invention is measured by a bending tester (for example, ``KES-FB2'', manufactured by Katotech Co., Ltd.) in two orthogonal directions, and the following equation is used. It is the value obtained by

Bending stiffness = (B in direction 1 + B in direction 2)/2

The spunbond nonwoven fabric of the present invention has a tensile modulus of 5 MPa or more and 100 MPa or less. This is because, when the tensile modulus is 100 MPa or less, deformation becomes easy, so that a hand-following touch is obtained, and when it is 5 MPa or more, an appropriate sense of resistance is obtained. 80 MPa or less is preferable, as for this tensile modulus, 60 MPa or less is more preferable, and 40 MPa or less is still more preferable. Moreover, 7 MPa or more is preferable, 9 MPa or more is more preferable, and 11 MPa or more is still more preferable. The tensile modulus of elasticity can be controlled by the above-described thermoplastic resin, additives, fiber diameter, and/or spinning speed described later, weight per unit area, apparent density, bonding method, and the like.

The tensile modulus of the spunbond nonwoven fabric referred to in the present invention refers to the ``6.3.1 Standard Time'' of ``6.3 Tensile Strength and Elongation (ISO Method)'' of JIS L1913:2010 ``General Nonwoven Test Method''. It is the arithmetic average of the tensile modulus of two orthogonal directions by a tensile test of at least 5 cm. This tensile modulus is the value obtained by obtaining the curve (stress-strain curve) obtained by the load and elongation, obtaining the largest (the increase in the load relative to the elongation) slope in the region of 20% or less of elongation, and dividing the cross-sectional area. _{In addition, the cross-sectional area of the present invention is the product of the sample width and the thickness (T 0} ) under a load of 0.5 g/cm 2 measured by a compression tester (for example, "KES-FB3", manufactured by Katotech).

The spunbond nonwoven fabric of the present invention preferably has a tensile strength of 0.3 (N/5 cm)/(g/m 2) or more and 10 (N/5 cm)/(g/m 2) or less per unit area. When the tensile strength per weight per unit area is 0.3 (N/5 cm)/(g/m 2) or more, it is possible to withstand process passability and use as a product when manufacturing paper diapers, etc., and 10 (N/N/ It is because it can have both flexibility by being 5 cm)/(g/m 2) or less.

The tensile strength per weight per unit area is more preferably 8 (N/5 cm)/(g/m 2) or less, and still more preferably 6 (N/5 cm)/(g/m 2) or less. Moreover, 0.4 (N/5 cm)/(g/m 2) or more is more preferable, and 0.5 (N/5 cm)/(g/m 2) or more is still more preferable. The tensile strength per weight per unit area can be controlled by the above-described thermoplastic resin, additives, fiber diameter, and/or the spinning speed, weight per unit area, apparent density, and bonding described later.

The tensile strength of the spunbond nonwoven fabric referred to in the present invention is performed according to ``6.3.1 Standard Time'' of ``6.3 Tensile Strength and Elongation (ISO Method)'' of JIS L1913:2010 ``General Nonwoven Test Method'', and the holding interval is at least. It is a value obtained by dividing the average of the tensile strengths (strength when the sample is broken) in two orthogonal directions by a 5 cm tensile test by the weight per unit area.

It is preferable that the spunbond nonwoven fabric of the present invention has a surface roughness SMD of 1.0 µm or more and 2.8 µm or less by the KES method (Kawabata Evaluation System) on at least one side. When the surface roughness SMD is 1.0 μm or more, it is possible to prevent the spunbond nonwoven fabric from becoming excessively densified, resulting in deterioration of texture or impairment of flexibility, and when it is 2.8 μm or less, the surface is smooth and the texture is small, This is because it has an excellent touch. As for this SMD, 1.3 micrometers or more are more preferable, and 1.6 micrometers or more are still more preferable. Moreover, 2.6 micrometers or less are more preferable, and 2.4 micrometers or less are still more preferable. The surface roughness SMD can be controlled by the above-described fiber diameter and/or the apparent density and bonding method described later.

The surface roughness SMD referred to in the present invention is a value obtained by measuring the surface roughness SMD in two orthogonal directions with a surface tester (for example, KES-FB4, manufactured by Katotech), and obtained by the following equation.

Surface roughness SMD = (Surface roughness SMD in direction 1 + Surface roughness SMD in direction 2)/2

It is important that the ΔMR of the spunbond nonwoven fabric of the present invention is 0.5% or more and 15% or less. As a result of intensive investigation, the present inventors have found that there is a high correlation between ΔMR, which is a parameter conventionally used as an index of moisture absorption and desorption of fibers, and the feel of the spunbond nonwoven fabric. By setting the ΔMR to 0.5% or more, more preferably 2% or more, the surface of the spunbond nonwoven fabric is in a state in which moisture is adequately absorbed, resulting in a good tactile feel with a moist feeling upon contact with the surface. On the other hand, by setting the ΔMR to 15% or less, more preferably 10% or less, and still more preferably 7% or less, a tactile feel without stickiness is obtained. In addition, when ΔMR is in the above range, it is possible to have slipperiness and flexibility suitable for high-speed production of spunbond nonwoven fabrics, and a spunbond nonwoven fabric having excellent high-order workability.

ΔMR can be adjusted by the type of the polyester component, the number average molecular weight of the polyethylene glycol contained, and the amount of copolymerization. In the present invention, ΔMR refers to a value measured and calculated by the following method.

The ΔMR (%) of the spunbond nonwoven fabric in the present invention refers to a value measured and calculated by the following method.

(1) 3 g of a measurement sample is freeze-crushed, dried under vacuum at a drying temperature of 110°C for 24 hours, and the absolute dry mass (W _d ) thereof is measured.

(2) The sample is left in a humidified thermo-hygrostat at 20°C×65%RH for 24 hours, and the mass (W ₂₀ ) of the sample in equilibrium is measured.

(3) Next, the setting of the thermo-hygrostat is changed to 30° C.×90% RH, and the mass (W ₃₀ ) after leaving for an additional 24 hours is measured, and it is calculated based on the following equation.

ΔMR=(W ₃₀ -W ₂₀ )/W _d (%).

It is preferable that the spunbond nonwoven fabric of the present invention has a thickness of 0.05 mm or more and 1.50 mm or less. This is because moderate cushioning properties are obtained when the thickness is 0.05 mm or more, and bending flexibility is obtained when the thickness is 1.50 mm or less. This thickness is more preferably 0.14 mm or less, and even more preferably 0.13 mm or less. Moreover, 0.07 mm or more is more preferable, and 0.09 mm or more is still more preferable.

_{The thickness of the spunbond nonwoven fabric in the present invention refers to the thickness (T 0} ) under a load of 0.5 g/cm 2 measured by a compression tester (KES-FB3, manufactured by Katotech).

The spunbond nonwoven fabric of the present invention preferably has a weight per unit area of 10 g/m 2 or more and 100 g/m 2 or less. This is because when the weight per unit area is 10 g/m 2 or more, it is easy to obtain a thickness suitable for use as a sanitary material and mechanical strength that can be provided for practical use, and when it is 100 g/m 2 or less, it is easy to obtain air permeability and flexibility. The weight per unit area is more preferably 80 g/m 2 or less, and still more preferably 60 g/m 2 or less.

The weight per unit area (g/m2) of the spunbond nonwoven fabric in the present invention is based on 6.2 "Mass per unit area" of JIS L1913:2010, and 3 specimens of 20cm x 25cm are collected per 1m of the width of the sample. The mass (g) in the standard state is measured, and the mass per 1 m 2 calculated from the average value is indicated.

It is preferable that the spunbond nonwoven fabric of the present invention has an apparent density of 0.01 g/cm 3 or more and 0.30 g/cm 3 or less. This is because, when it is 0.01 g/cm 3 or more, it is easy to obtain dimensional stability that can be provided for practical use, and when it is 0.30 g/cm 3 or less, it is easy to obtain air permeability and flexibility. This apparent density is more preferably 0.25 g/cm 3 or less, and even more preferably 0.20 g/cm 3 or less. Moreover, 0.03 g/cm 3 or more is more preferable, and 0.05 g/cm 3 or more is still more preferable.

The apparent density of the spunbond nonwoven fabric referred to in the present invention is a value obtained by dividing the weight per unit area by the thickness.

[Method of manufacturing spunbond nonwoven fabric]

Next, a preferred embodiment of manufacturing the spunbond nonwoven fabric of the present invention will be described in detail.

The spunbond method for manufacturing a spunbond nonwoven fabric involves melting a resin, spinning it from a spinneret, cooling and solidifying the resulting yarn, drawing it with an ejector, drawing it, and collecting it on a moving net to form a nonwoven fiber web. After that, it is a method of manufacturing a nonwoven fabric that requires a step of heat bonding.

As the shape of the spinneret or ejector to be used, various things, such as a circle or a rectangle, can be adopted. Among them, it is a preferred embodiment to use a combination of a rectangular cage and a rectangular ejector from the viewpoint that the amount of compressed air is relatively small, and fusion or abrasion between the threads is difficult to occur.

In the present invention, the raw material polymer is vacuum-dried as necessary, then melted and spun. The spinning temperature is preferably 200°C or more and 270°C or less for polyolefin systems, and 240°C or more and 320°C or less for polyester systems. This is because by setting the spinning temperature within the above range, it is possible to obtain a stable molten state and excellent spinning stability.

The thermoplastic resin as a raw material is melted in an extruder, weighed, fed to a spinneret, and discharged as long fibers. At this time, it is also a preferable embodiment to select two or more raw material polymers and supply them from a chip blend or another extruder to obtain a composite fiber during spinning.

The yarn of the discharged long fibers is subsequently cooled. As a method of cooling the discharged yarn, for example, a method of forcibly spraying cold air onto the yarn, a method of naturally cooling at the ambient temperature around the yarn, and between the spinneret and the ejector. A method of adjusting the distance, etc. may be mentioned, or a method of combining these methods may be employed. Further, the cooling conditions can be appropriately adjusted and adopted in consideration of the discharge amount per single hole of the spinneret, the spinning temperature, and the ambient temperature.

Subsequently, the cooled and solidified thread is pulled and stretched by compressed air injected from the ejector.

The spinning speed is preferably 2000 m/min or more, more preferably 3000 m/min or more, and still more preferably 4000 m/min or more. By setting the spinning speed to 2000 m/min or more, high productivity is obtained, and orientation crystallization of the fibers proceeds to obtain long fibers of high strength. The spinning speed in the present invention is the single fiber fineness, which is a value calculated by rounding off the second decimal place with the mass per 10,000 m in length from the solid density of the raw material polymer as the single fiber fineness, and each condition It is a value calculated by the following equation from the discharge amount of the resin discharged from the spinneret single hole set in (hereinafter, referred to as the single hole discharge amount).

Spinning speed = (10000×single hole discharge amount)/single fiber fineness

Subsequently, the obtained long fibers are collected on a moving net to form a nonwoven fiber web. In the present invention, since the fibers are drawn at a high spinning speed, the fibers emitted from the ejector are trapped in the net while being controlled by a high-speed airflow, so that a nonwoven fabric with less entanglement of fibers and high uniformity can be obtained. Such a nonwoven fabric can also be made into a spunbond nonwoven fabric with only one web, but it is also a preferable aspect from the viewpoint that productivity can be improved by arranging a plurality of spinning facilities in the process direction and overlapping a plurality of webs. In addition, the raw material or process conditions can be changed for each web at this time. In addition, it is one of the preferred embodiments to laminate the melt blown nonwoven fabric. In the present invention, these laminates are also collectively referred to as a nonwoven fiber web.

Subsequently, by integrating the obtained nonwoven fibrous web by heat bonding, the intended spunbond nonwoven fabric can be obtained.

As a method of integrating the nonwoven fibrous web by thermal bonding, a thermal emboss roll in which pieces (corrugations) are applied to the upper and lower pair of roll surfaces, respectively, a roll with a flat (smooth) surface on one roll, and a roll on the other. A method of thermal bonding with various rolls, such as a thermal emboss roll formed of a combination of rolls with sculpted (corrugated portions) on the surface, and a thermal calender roll formed of a combination of a pair of top and bottom flat (smooth) rolls, may be mentioned .

It is preferable that the embossed bonding area ratio at the time of thermal bonding is 5% or more and 30% or less. By setting the bonding area to preferably 5% or more, more preferably 10% or more, the strength that can be provided for practical use as a spunbond nonwoven fabric can be obtained. On the other hand, when the bonding area is preferably 30% or less, more preferably 20% or less, sufficient flexibility can be obtained, particularly when used as a spunbond nonwoven fabric for hygiene materials.

The bonding area referred to herein means a ratio occupied by the entire nonwoven fabric at a portion where the convex portion of the upper roll and the convex portion of the lower roll overlap and contact the nonwoven fibrous web in the case of thermal bonding with a pair of uneven rolls. In addition, in the case of thermal bonding by a roll having irregularities and a flat roll, it means the proportion of the convex portions of the roll having irregularities occupied in the entire nonwoven fabric at a portion abutting the nonwoven fibrous web.

As the shape of the sculpture applied to the heat embossing roll, a circle, an oval, a square, a rectangle, a parallelogram, a rhombus, a regular hexagon, and a regular octagon can be used.

It is preferable that the line pressure of the thermal emboss roll at the time of thermal bonding is 5 N/cm or more and 70 N/cm or less. When the linear pressure of the roll is preferably 5 N/cm or more, more preferably 10 N/cm or more, and still more preferably 20 N/cm or more, it is possible to sufficiently heat-bond and obtain strength that can be provided in practical use as a nonwoven fabric. On the other hand, when the linear pressure of the roll is preferably 70 N/cm or less, more preferably 60 N/cm or less, and even more preferably 50 N/cm or less, sufficient flexibility can be obtained, especially when used as a nonwoven fabric for hygiene materials. have.

Example

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

(1) Single fiber fiber diameter (㎛):

"S-5500" manufactured by Hitachi High Technologies was used for the measurement.

(2) Weight per unit area

Based on 6.2 "mass per unit area" of JIS L1913:2010, 3 specimens of 20 cm x 25 cm were taken per 1 m of the width of the sample, and each mass (g) in the standard state was measured, and the average value thereof The mass per 1 m 2 calculated from was taken as the weight per unit area (g/m 2 ).

(3) Thickness T ₀ (㎜)

As a compression tester, "KES-FB3" manufactured by Katotech was used for the measurement.

(4) apparent density

The value obtained by dividing the weight per unit area by the thickness measured above was taken as the apparent density (g/m ³ ).

(5) Bending stiffness (μN·㎠/cm), bending return property (cm ^-1 )

As a bending tester, "KES-FB2" manufactured by Katotech was used for the measurement.

(6) Tensile modulus (MPa)

As a tensile tester, "AGS1KNX" manufactured by Shimadzu Corporation was used for the measurement. In addition, _{the measurement of the thickness T 0} (mm) of the sample was performed using the same apparatus as in (3).

(7) Soft feeling (grade)

Ten randomly selected spunbond nonwoven fabrics were touched by hand, and each spunbonded nonwoven fabric was evaluated according to the following criteria. For each nonwoven fabric, the average score of the evaluation result was taken as the soft feeling of the nonwoven fabric.

・5: It is very comfortable and is a soft feeling that I like very much.

・4: It is a little comfortable, and it is a soft feeling that I like a little

・3: Not unpleasant but not pleasant, not disliked but not good soft feeling

・2: Slightly unpleasant, slightly disliked soft feeling

・1: Very unpleasant, very disliked soft feeling

(Example 1)

As the thermoplastic resin, a copolymerized polyethylene terephthalate having a number average molecular weight of 5500 and a copolymerization amount of 8% by weight of the polyethylene glycol contained was used (in Table 1 shown below, it is expressed as "PET-PEG"). First, this thermoplastic resin was melted in an extruder, and discharged at a single hole discharge amount of 0.4 g/min from a rectangular orifice having a spinning temperature of 290°C and a hole diameter of 0.30 mm. After cooling and solidifying the discharged yarn, it is pulled and stretched by compressed air having a pressure at the ejector of 0.10 MPa in a rectangular ejector, and is collected on a moving net to form a nonwoven fiber web containing copolyester filaments. Got it. Subsequently, the obtained nonwoven fibrous web was thermally bonded with a pair of upper and lower heat embossing rolls composed of an upper roll and a lower roll. At this time, as the upper roll, an embossed roll made of metal and having a polka-dot pattern having a depth of 0.5 mm and having an adhesion area ratio of 16% was used. In addition, for the lower roll, a pair of upper and lower heat emboss rolls composed of a metal flat roll was used. In addition, the line pressure of the heat embossing roll was set to 50 N/cm, and the heat bonding temperature was set to 230°C. Table 1 shows the evaluation results of the obtained spunbond nonwoven fabric.

(Example 2)

A spunbond nonwoven fabric was obtained in the same manner as in Example 1, except that the moving speed of the net was increased and the weight per unit area of the spunbond nonwoven fabric was reduced from 27 g/m 2 to 15 g/m 2. Table 1 shows the evaluation results of the obtained spunbond nonwoven fabric.

(Example 3)

A spunbond nonwoven fabric was obtained in the same manner as in Example 1 except that the engraving depth of the upper roll of the heat embossing roll was changed from 0.5 mm to 0.2 mm. Table 1 shows the evaluation results of the obtained spunbond nonwoven fabric.

(Example 4)

Since the pieces of the upper roll of the thermal emboss roll have a polka dot pattern, engraving depth of 0.5 mm, and an adhesion area rate of 16%, a square with a side of 10 mm (a square with a side of 10 mm) and a depth of 1 mm. And a spunbond nonwoven fabric was obtained in the same manner as in Example 1, except that the adhesive area ratio was 10%. Table 1 shows the evaluation results of the obtained spunbond nonwoven fabric.

(Example 5)

As the thermoplastic resin, polypropylene to which 0.5% by mass of ethylenebisstearic acid amide having 38 carbon atoms was added as a lubricant was used (in Table 1 shown below, it is expressed as "PP-EBA"). First, this thermoplastic resin was melted with an extruder, and discharged at a spinning temperature of 230°C from a rectangular orifice having a pore diameter φ of 0.30 mm at a single hole discharge amount of 0.4 g/min. After cooling and solidifying the discharged yarn, it is pulled and stretched by compressed air having a pressure at the ejector of 0.10 MPa in a rectangular ejector, and is collected on a moving net to form a nonwoven fibrous web containing copolyester filaments. Got it. Subsequently, the obtained nonwoven fibrous web was thermally bonded with a pair of upper and lower heat embossing rolls composed of an upper roll and a lower roll. At this time, as the upper roll, an embossed roll made of metal and having a polka-dot pattern having a depth of 0.5 mm and having an adhesion area ratio of 16% was used. In addition, for the lower roll, a pair of upper and lower heat emboss rolls composed of a metal flat roll was used. In addition, the line pressure of the thermal emboss roll was 50 N/cm, and the thermal bonding temperature was 130°C. Table 1 shows the evaluation results of the obtained spunbond nonwoven fabric.

(Example 6)

As a thermoplastic resin, a spunbond nonwoven fabric was obtained in the same manner as in Example 1, except that polyethylene glycol was not copolymerized with polyethylene terephthalate (indicated as "PET" in Table 1 shown below). Table 1 shows the evaluation results of the obtained spunbond nonwoven fabric.

(Comparative Example 1)

As a thermoplastic resin, a spunbond nonwoven fabric was obtained in the same manner as in Example 5 except that it was changed to polypropylene to which ethylenebisstearic acid amide was not added (indicated as "PP" in Table 1 shown below). Table 1 shows the evaluation results of the obtained spunbond nonwoven fabric.

(Comparative Example 2)

A spunbond nonwoven fabric was obtained in the same manner as in Example 1 except that the single hole discharge amount was changed from 0.4 g/min to 0.2 g/min, and the pressure in the ejector of compressed air was changed from 0.10 MPa to 0.05 MPa. Table 1 shows the evaluation results of the obtained spunbond nonwoven fabric.

As shown in Table 1, in Examples 1 to 6, the sensory evaluation results were 3.5 to 4.5, and the soft feeling was excellent.

On the other hand, as shown in Comparative Examples 1 and 2, that the spunbond nonwoven fabric had too large a bending return property or too low a tensile modulus was a result of a sensory evaluation of 3 or less, indicating that the soft feeling was inferior.

As described above, preferred embodiments of the present invention have been described, but the present invention is not limited to the above-described embodiments, and various modifications and substitutions can be added to the above-described embodiments without departing from the scope of the present invention. .

In addition, this application is based on the Japanese patent application (Japanese Patent Application No. 2018-183754) filed on September 28, 2018, the content of which is incorporated by reference during this application.

According to the present invention, there is provided a spunbond nonwoven fabric having a very familiar touch to the hand (excellent soft feeling).

Claims (3)

A spun-bonded nonwoven fabric composed of fibers containing a thermoplastic resin, wherein the spun-bonded non-woven fabric and the flexural return of the 0.2㎝ than ^-1 1.0㎝ ^-1 or less, or less also 100㎫ than the tensile modulus of the spun-bonded nonwoven fabric 5㎫, Spunbond nonwoven fabric. The spunbond nonwoven fabric according to claim 1, wherein the spunbond nonwoven fabric has a bending stiffness of 10 μN·cm 2 /cm or more and 300 μN·cm 2 /cm or less. The spunbond nonwoven fabric according to claim 1 or 2, wherein the spunbond nonwoven fabric has an apparent density of 0.01 g/cm 3 or more and 0.30 g/cm 3 or less.