阅读说明：本技术 纺粘无纺布 (Spun-bonded non-woven fabric ) 是由 梶原健太郎 胜田大士 西口结香 船津义嗣 于 2019-09-11 设计创作，主要内容包括：本发明涉及弯曲恢复性为0.2cm～(-1)以上且1.0cm～(-1)以下并且拉伸弹性模量为5MPa以上且100MPa以下的纺粘无纺布。(The present invention relates to a bend recovery of 0.2cm ‑1 Above and 1.0cm ‑1 And a tensile elastic modulus of 5MPa or more and 100MPa or less.)

1. A spunbonded nonwoven fabric comprising fibers comprising a thermoplastic resin, the spunbonded nonwoven fabric having a bending recovery of 0.2cm^-1Above and 1.0cm^-1The spun-bonded nonwoven fabric has a tensile elastic modulus of 5MPa or more and 100MPa or less.

2. The spunbonded nonwoven fabric according to claim 1, wherein the spunbonded nonwoven fabric has a flexural rigidity of 10 μ N-cm²300 μ N/cm or more²Less than/cm.

3. The spunbonded nonwoven according to claim 1 or 2, wherein the spunbonded nonwoven has an apparent density of 0.01g/cm³Above and 0.30g/cm³The following.

Technical Field

The present invention relates to a spunbonded nonwoven fabric which is excellent in touch and is particularly suitable for use in sanitary materials.

Background

In general, nonwoven fabrics used for sanitary materials such as disposable diapers and sanitary napkins are discarded after a small number of uses, and therefore, they are required to be inexpensive for wide use, and high productivity is strongly demanded. Therefore, a spunbond nonwoven fabric produced by combining a spunbond method, which is a method of forming a web with excellent productivity, and an embossing method, which is a method of bonding fibers with excellent productivity, is widely used.

On the other hand, since sanitary materials are often in direct contact with the delicate skin of infants and the like, excellent touch is strongly demanded, and for example, a touch like underwear using a general woven knitted fabric is demanded, but a spunbond nonwoven fabric having such a touch has not been realized yet, and various studies have been made to improve the touch.

For example, patent document 1 proposes a spunbonded nonwoven fabric comprising polyolefin fibers to which a fatty acid amide compound is added.

Documents of the prior art

Patent document

Patent document 1: japanese patent laid-open publication No. 2018-119247.

Disclosure of Invention

Problems to be solved by the invention

According to the technique disclosed in patent document 1, the fatty acid amide compound serves as a lubricant to soften the base polymer, and therefore the stiffness (softening) of the spunbonded nonwoven fabric can be reduced. However, as a result of the test piece test (panel test) by the inventors of the present application, it is found that the ideal touch is not simply low in stiffness but good in touch, particularly comfortable in feeling. The present invention has been made in view of the above circumstances, and an object thereof is to provide a spunbonded nonwoven fabric having a good texture (hereinafter referred to as an excellent soft texture).

Means for solving the problems

The inventors of the present invention have made extensive studies to achieve the above object, and as a result, have found that a particularly comfortable touch feeling can be obtained when the rubber composition has a specific bending recovery property and a specific tensile elastic modulus, and that an excellent soft feeling with a good touch feeling can be obtained by controlling the values of these physical properties.

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

The spun-bonded nonwoven fabric according to the embodiment of the present invention is composed of fibers containing a thermoplastic resin, and the spun-bonded nonwoven fabric has a bending recovery of 0.2cm^-1Above and 1.0cm^-1The spun-bonded nonwoven fabric has a tensile elastic modulus of 5MPa or more and 100MPa or less.

According to a preferred embodiment of the spunbonded nonwoven fabric of the invention, the spunbonded nonwoven fabric has a flexural rigidity of 10 μ N · cm²300 μ N/cm or more²Less than/cm.

According to a preferred embodiment of the spunbonded nonwoven fabric of the invention, the spunbonded nonwoven fabric has an apparent density of 0.01g/cm³Above and 0.30g/cm³The following.

ADVANTAGEOUS EFFECTS OF INVENTION

According to the present invention, a spun-bonded nonwoven fabric having excellent soft feeling can be obtained. In particular, the spunbonded nonwoven fabric of the present invention has excellent soft feeling characteristics with good hand feeling, and therefore can be suitably used for sanitary materials such as disposable diapers and sanitary napkins which are strongly required to have both high productivity and touch feeling.

Detailed Description

The spunbonded nonwoven fabric of the invention is composed of fibers containing thermoplastic resin and has a bending recovery of 0.2cm^-1Above, 1.0cm^-1The tensile modulus is 5MPa or more and 100MPa or less. This will be described in detail below.

[ thermoplastic resin ]

The thermoplastic resin used for the spunbonded nonwoven fabric of the present invention is not particularly limited, and examples thereof include aromatic polyester polymers such as polyethylene terephthalate, polypropylene terephthalate, polybutylene terephthalate, and polyhexamethylene terephthalate, and copolymers thereof, aliphatic polyester polymers such as polylactic acid, polyethylene succinate, polybutylene succinate adipate, polyhydroxybutyrate-polyhydroxyvalerate copolymer, and polycaprolactone, and copolymers thereof, aliphatic polyamide polymers such as polyamide 6, polyamide 66, polyamide 610, polyamide 10, polyamide 12, and polyamide 6-12, and copolymers thereof, polyolefin polymers such as polypropylene, polyethylene, polybutylene, and polymethylpentene, and copolymers thereof, water-insoluble ethylene-vinyl alcohol copolymer polymers containing 25 to 70 mol% of ethylene units, and copolymers thereof, At least one selected from polystyrene, polydiene, chlorine, polyolefin, polyester, polyurethane, polyamide, and fluorine-based elastic polymers.

Here, a polymer in which a lubricant is added to a polyolefin resin is a preferred embodiment in view of easily obtaining both low flexural rigidity and low flexural recovery property, and a suitable tensile elastic modulus. Examples of such polymers include polypropylene to which a fatty acid amide compound is 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. Specific examples thereof include 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' -methylene-bis-myristic acid amide, N '-methylene-bis-palmitic acid amide, N' -methylene-bis-behenic acid amide, N '-methylene-bis-oleic acid amide, N' -methylene-bis-erucic acid amide, N '-ethylene-bis-oleic acid amide, N' -ethylene-bis-erucic acid amide, and the like, and a plurality of these fatty acid amide compounds are used in combination, which is also a preferred embodiment.

In addition, from the viewpoint of easy compatibility between low bending rigidity and low bending recovery, a polymer obtained by softening a polyester polymer by copolymerization or blending with another polymer is preferable. As examples of such polymers, copolymerization of polyethylene glycol in a polyester resin or formation of a polymer mixture is a particularly preferred embodiment from the following points of view: the low flexural rigidity, the low flexural recovery and the appropriate tensile modulus can be easily obtained at the same time by the molecular weight and the copolymerization ratio of the polyethylene glycol.

To these thermoplastic resins, additives such as antioxidants, weather stabilizers, light stabilizers, antistatic agents, antifogging agents, antiblocking agents, nucleating agents, and pigments, or other polymers may be added as necessary within a range not to impair the effects of the present invention.

[ fibers ]

The fibers constituting the spunbonded nonwoven fabric of the invention preferably have a filament diameter of 5 to 30 μm. This is because: high uniformity and flexibility can be obtained by making the diameter of the single fiber less than 30 μm; when the thickness is 5 μm or more, a sufficient touch feeling can be obtained. The diameter of the single fiber is more preferably 25 μm or less, and still more preferably 20 μm or less. Further, it is more preferably 7 μm or more, and still more preferably 9 μm or more.

The single fiber diameter in the present invention is a value obtained by taking a surface photograph of 500 to 1000 times with a microscope, measuring the widths of 100 fibers in total selected at random, and calculating the single fiber diameter (μm) from the arithmetic average.

[ spunbonded nonwoven Fabric ]

The spunbonded nonwoven fabric of the invention has a bending recovery of 0.2cm^-1Above, 1.0cm^-1The following. This is because: by making the bending recovery property 1.0cm^-1As follows, a comfortable feeling can be obtained when the bending is restored; the passage is 0.2cm^-1As described above, a proper recovery difficulty can be obtained, and a natural texture can be obtained. The bending recovery is preferably 0.8cm^-1Hereinafter, more preferably 0.6cm^-1The following. Further, it is preferably 0.3cm^-1Above, more preferably 0.4cm^-1The above.

The bending recovery property can be controlled by the thermoplastic resin, additives, fiber diameter, and/or spinning speed, basis weight, apparent density, and bonding method described later.

The bending recovery of the spunbonded nonwoven fabric of the present invention is a value obtained by measuring the bending rigidity (B) and the bending retardation (2HB) in 2 directions perpendicular to each other by a bending tester (for example, "KES-FB 2", manufactured by KATOTECH) and by the following equation.

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

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

Bending recovery ═ bending hysteresis/bending stiffness

The spunbonded nonwoven fabric of the invention preferably has a flexural rigidity of 10. mu.N cm²More than cm, 300 mu N cm²Less than/cm. This is because: by making the flexural rigidity 300. mu.N.cm²A soft touch feeling which is easily bendable can be obtained at a value of/cm or less; passing through 10 μ N cm²A moderate bending response can be obtained at a value of/cm or more. The flexural rigidity is more preferably 250. mu.N.cm²Is less than or equal to cm, and more preferably 200. mu.N cm²Less than/cm. Further, it is more preferably 20. mu.N cm²Is more than or equal to cm, and is more preferably 30 μ N cm²More than/cm. The flexural rigidity can be controlled by the thermoplastic resin, additives, fiber diameter, and/or spinning speed, basis weight, apparent density, and bonding method, which will be described later.

The bending rigidity of the spunbonded nonwoven fabric of the present invention is a value obtained by measuring the bending rigidity (B) in 2 directions perpendicular to each other by a bending tester (for example, "KES-FB 2", manufactured by KATOTECH).

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

The spun-bonded nonwoven fabric of the present invention has a tensile elastic modulus of 5MPa or more and 100MPa or less. This is because: when the tensile elastic modulus is 100MPa or less, the touch feeling following the hand can be obtained because the touch panel is easily deformed; when the pressure is 5MPa or more, a moderate resistance feeling can be obtained. The tensile modulus of elasticity is preferably 80MPa or less, more preferably 60MPa or less, and still more preferably 40MPa or less. The tensile elastic modulus is preferably 7MPa or more, more preferably 9MPa or more, and still more preferably 11MPa or more. The tensile modulus can be controlled by the thermoplastic resin, additives, fiber diameter, spinning speed, basis weight, apparent density, and bonding method, which will be described later.

The tensile modulus of the spunbonded nonwoven fabric of the invention is determined by the following method in accordance with JIS L1913: 2010 "general nonwoven Fabric test method" when the tensile Strength and elongation (ISO method) "of 6.3.1 Standard" is satisfiedAn arithmetic mean of tensile elastic moduli in 2 directions orthogonal to each other, obtained by a tensile test applied with a jig interval of at least 5 cm. The tensile modulus is a value obtained by obtaining a curve (stress-strain curve) obtained by the load and the elongation, and dividing the slope of the maximum (the increase in load with respect to the elongation) in a region where the elongation is 20% or less by the cross-sectional area. The cross-sectional area of the present invention is a sample width and 0.5g/cm measured by a compression tester (for example, "KES-FB 3", manufactured by KATOTECH)²Thickness under load (T)₀) The product of the two.

The spunbonded nonwoven fabric of the invention preferably has a tensile strength per unit area weight of 0.3(N/5 cm)/(g/m)²) 10(N/5 cm)/(g/m) above²) The following. This is because: by making the tensile strength per unit area weight 0.3(N/5 cm)/(g/m)²) As described above, the spunbonded nonwoven fabric can be used as a product that can withstand the process passability in the production of a paper diaper or the like; by a value of 10(N/5 cm)/(g/m)²) The flexibility can be achieved at the same time as follows.

The tensile strength per unit area weight is more preferably 8(N/5 cm)/(g/m)²) Hereinafter, more preferably 6(N/5 cm)/(g/m)²) The following. Further, more preferably 0.4(N/5 cm)/(g/m)²) The above ratio is more preferably 0.5(N/5 cm)/(g/m)²) The above. The tensile strength per unit area weight can be controlled by the thermoplastic resin, additives, fiber diameter, and/or spinning speed, unit area weight, apparent density, and bonding method described below.

The tensile strength of the spunbonded nonwoven fabric of the invention is determined by blending the components according to JIS L1913: 2010 "general nonwoven fabric test method" in "6.3 tensile strength and elongation (ISO method)" standard of "6.3.1", and an average of tensile strengths (strengths at break of the sample) in 2 directions orthogonal to each other, which are obtained by a tensile test with a jig interval of at least 5cm, is divided by a unit area weight.

The spunbonded nonwoven fabric of the present invention preferably has a surface roughness SMD of 1.0 μm to 2.8 μm by a KES method (Kawabata Evaluation System) on at least one surface. This is because: by setting the surface roughness SMD to 1.0 μm or more, it is possible to prevent the spunbonded nonwoven fabric from being excessively densified to deteriorate the texture or deteriorate the flexibility; when the particle diameter is 2.8 μm or less, the surface is smooth and less rough, and the feeling of touch to the skin is excellent. The SMD is more preferably 1.3 μm or more, and still more preferably 1.6 μm or more. Further, it is more preferably 2.6 μm or less, and still more preferably 2.4 μm or less. The surface roughness SMD can be controlled by the fiber diameter and/or the apparent density and the bonding method described later.

The surface roughness SMD in the present invention is a value obtained by measuring surface roughness SMDs in 2 directions perpendicular to each other by a surface tester (for example, KES-FB4, KATOTECH corporation) and calculating the SMD according to the following equation.

Surface roughness SMD ═ (surface roughness SMD in direction 1 + surface roughness SMD in direction 2)/2

It is important that the Δ MR of the spunbonded nonwoven fabric of the present invention is 0.5% or more and 15% or less. As a result of intensive studies, the inventors of the present application found that Δ MR, which is a parameter conventionally used as an index of moisture absorption and release properties of fibers, is highly correlated with the touch of a spunbond nonwoven fabric. When Δ MR is 0.5% or more, more preferably 2% or more, the surface of the spunbond nonwoven fabric becomes a state of moderate moisture absorption, and a good touch feeling with a moist feeling is obtained when the surface is in contact with the surface. On the other hand, when Δ MR is 15% or less, more preferably 10% or less, and still more preferably 7% or less, a non-sticky feeling is obtained. When Δ MR is in the above range, the spunbonded nonwoven fabric can have smoothness and flexibility suitable for high-speed production of the spunbonded nonwoven fabric, and can have excellent high-order processability.

The Δ MR can be adjusted by the kind of the polyester component, the number average molecular weight of the polyethylene glycol contained therein, and the copolymerization amount. The Δ MR in the present invention is a value measured and calculated by the following method.

The Δ MR (%) of the spunbonded nonwoven fabric in the present invention is a value measured and calculated by the following method.

(1) A3 g sample was freeze-ground and vacuum-dried at a drying temperature of 110 ℃ for 24 hours to measure the absolute dry mass (W)_d)。

(2) The sample was placed in a constant temperature and humidity machine conditioned at 20 ℃ C.. times.65% R.H. for 24 hours, and the mass (W) of the sample in an equilibrium state was measured₂₀)。

(3) Next, the settings of the thermostat and humidistat were changed to 30℃ × 90% r.h., and the mass (W) after leaving for 24 hours was further measured₃₀) And calculated based on the following formula.

·ΔMR＝(W₃₀-W₂₀)/W_d(％)。

The spunbonded nonwoven fabric of the invention preferably has a thickness of 0.05mm to 1.50 mm. This is because: by making the thickness 0.05mm or more, appropriate cushioning properties can be obtained; when the thickness is 1.50mm or less, the flexibility in bending can be obtained. The thickness is more preferably 0.14mm or less, and still more preferably 0.13mm or less. Further, it is more preferably 0.07mm or more, and still more preferably 0.09mm or more.

The thickness of the spunbonded nonwoven fabric in the present invention means 0.5g/cm measured by a compression tester (KES-FB3, KATOTECH Co., Ltd.)²Thickness under load (T)₀)。

The spunbonded nonwoven according to the invention preferably has a weight per unit area of 10g/m²Above, 100g/m²The following. This is because: by setting the weight per unit area to 10g/m²Thus, the thickness suitable for the use of sanitary materials and the mechanical strength suitable for practical use can be easily obtained; the passing rate is 100g/m²Hereinafter, air permeability and flexibility are easily obtained. The weight per unit area is more preferably 80g/m²Hereinafter, more preferably 60g/m²The following.

The spun-bonded nonwoven fabric of the present invention has a weight per unit area (g/m)²) Means according to JIS L1913: 2010 "Mass per unit area" of 6.2, 3 test pieces of 20cm × 25cm were collected for 1m of the width of the sample, the respective masses (g) in the standard state were weighed, and the average value thereof was calculated for 1m²The quality of (c).

The spunbonded nonwoven according to the invention preferably has an apparent density of 0.01g/cm³Above, 0.30g/cm³The following. This is due toComprises the following steps: the passing rate was 0.01g/cm³As described above, practical form stability is easily obtained, and the bend recovery rate is easily reduced; the passing rate was 0.30g/cm³Hereinafter, air permeability and flexibility are easily obtained. The apparent density is more preferably 0.25g/cm³Hereinafter, more preferably 0.20g/cm³The following. Further, it is more preferably 0.03g/cm³Above, more preferably 0.05g/cm³The above.

The apparent density of the spunbonded nonwoven fabric of the invention is a value obtained by dividing the weight per unit area by the thickness.

[ method for producing spunbonded nonwoven Fabric ]

Preferred embodiments for producing the spunbonded nonwoven fabric of the present invention will be described in detail below.

The spunbond method for producing a spunbond nonwoven fabric is a method for producing a nonwoven fabric requiring the following steps: the resin is melted, spun through a spinneret, cooled and solidified, and the obtained yarn is drawn and stretched by a jet, collected on a moving web, formed into a nonwoven fiber web, and thermally bonded.

The spinneret and the ejector used may have various shapes such as a circle and a rectangle. Among these, the combination of the rectangular spinneret and the rectangular ejector is a preferred embodiment from the viewpoint that the amount of compressed air used is small and welding and friction between the yarns are not easily caused.

In the present invention, the raw material polymer is vacuum-dried as necessary, and then melt-spun. The spinning temperature is preferably 200 ℃ to 270 ℃ in the case of polyolefin, and preferably 240 ℃ to 320 ℃ in the case of polyester. When the spinning temperature is within the above range, a stable molten state can be formed, and excellent spinning stability can be obtained.

A thermoplastic resin as a raw material is melted and metered in an extruder, and is supplied to a spinneret to be spun as a long fiber. In this case, it is also a preferred embodiment to select a base polymer having 2 or more components, blend the polymer into chips (chip blend) or supply the polymer from a different extruder, and form a conjugate fiber during spinning.

The spun long fiber yarn is then cooled, and examples of a method for cooling the spun yarn include a method of forcibly blowing a cold air to the yarn, a method of natural cooling by the temperature of the atmosphere surrounding the yarn, and a method of adjusting the distance between the spinneret and the ejector, or a combination of these methods. The cooling conditions may be appropriately adjusted in consideration of the discharge amount per one hole of the spinneret, the spinning temperature, the atmospheric temperature, and the like.

Subsequently, the cooled and solidified sliver is drawn and stretched by the compressed air injected from the injector.

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 is achieved, and the oriented crystallization of the fiber is promoted, whereby a long fiber having high strength can be obtained. The spinning speed in the present invention is a value calculated from a single fiber fineness obtained by calculating a mass per 10000m in length as the single fiber fineness from the single fiber diameter and the solid density of the base polymer and rounding off the second decimal place, and a discharge amount of the resin discharged from a spinneret set under each condition (hereinafter referred to as a discharge amount per one hole), and by using the following formula.

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

Subsequently, the long fibers obtained were collected on a moving web to form a nonwoven web. In the present invention, since the drawing is performed at a high spinning speed, the fibers discharged from the ejector are collected on the web in a state of being controlled by a high-speed air flow, and a nonwoven fabric having high uniformity with less entanglement of the fibers can be obtained. Such a nonwoven fabric may be formed of only 1 web, but a web in which a plurality of spinning devices are arranged side by side in the process direction and a plurality of webs are stacked is also a preferred embodiment from the viewpoint of productivity improvement. In this case, the raw material and process conditions may be changed for each web. Further, it is also one of preferred embodiments to laminate meltblown nonwoven fabrics. In the present invention, these laminates are also collectively referred to as nonwoven fabric webs.

Next, the obtained nonwoven web is integrated by thermal bonding, whereby a desired spunbond nonwoven fabric can be obtained.

Examples of a method for integrating the nonwoven web by thermal bonding include a method of thermal bonding using the following various rollers: hot embossing rollers in which engraving (uneven portions) is performed on the surfaces of the upper and lower pairs of rollers; a hot embossing roll in which a roll having a flat (smooth) roll surface and a roll having an engraved (uneven) roll surface are combined; and a hot calendering roll composed of a pair of upper and lower flat (smooth) rolls; and the like.

The embossed bonding area ratio at the time of thermal bonding is preferably 5% or more and 30% or less. By setting the bonding area to 5% or more, more preferably 10% or more, it is possible to obtain strength that can be practically used as a spunbond nonwoven fabric. 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 the spunbonded nonwoven fabric is used as a sanitary material.

The bonding area here means a ratio of a portion of the nonwoven fabric in which the convex portion of the upper roll and the convex portion of the lower roll overlap each other and contact the nonwoven web, in the entire nonwoven fabric, when the nonwoven fabric is thermally bonded by a pair of rolls having concave and convex portions. In the case of thermal bonding between a roll having irregularities and a flat roll, the ratio of the portion of the irregularities of the roll in contact with the nonwoven web is the ratio of the entire nonwoven fabric.

As the shape of the engraving performed on the heat embossing roll, a circle, an ellipse, a square, a rectangle, a parallelogram, a rhombus, a regular hexagon, a regular octagon, or the like can be used.

The linear pressure of the heat-embossing roll at the time of thermal bonding is preferably 5N/cm or more and 70N/cm or less. By setting the linear pressure of the roll to 5N/cm or more, more preferably 10N/cm or more, and further preferably 20N/cm or more, it is possible to sufficiently thermally bond the rolls, and to obtain a strength which can be practically used as a nonwoven fabric. On the other hand, by setting the linear pressure of the roller to preferably 70N/cm or less, more preferably 60N/cm or less, and further preferably 50N/cm or less, sufficient flexibility can be obtained particularly when used as a nonwoven fabric for sanitary materials.

Examples

The present invention will be specifically described below based on examples. However, the present invention is not limited to these examples. In the measurement of the physical properties, the measurement is performed by the above-described method, for the part which is not particularly described. However, the present invention is not limited to the description of the embodiments.

(1) Single fiber diameter (μm):

for the measurement, S-5500 manufactured by Hitachi high tech Co., Ltd.

(2) Weight per unit area

Based on JIS L1913: 2010 "Mass per unit area" of 6.2, 3 test pieces of 20cm × 25cm were collected for 1m of the width of the sample, the respective masses (g) in the standard state were measured, and the average value thereof was calculated for each 1m²Mass of (2) as weight per unit area (g/m)²)。

(3) Thickness T₀(mm)

The compression tester was used as "KES-FB 3" manufactured by KATOTECH.

(4) Apparent density

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

(5) Flexural rigidity (μ N · cm)²,/cm), bending recovery (cm)^-1)

For the measurement, "KES-FB 2" manufactured by KATOTECH was used as a bending tester.

(6) Modulus of elasticity in tension (MPa)

For the measurement, "AGS 1 KNX" manufactured by shimadzu corporation was used as a tensile tester. Note that the thickness T of the sample₀The same apparatus as in (3) above was used for the measurement of (mm).

(7) Soft feeling (grade)

Any selected 10 persons touched the spunbonded nonwoven fabric with their hands, and the spunbonded nonwoven fabrics were evaluated according to the following criteria. The average of the evaluation results of the nonwoven fabrics was defined as the soft feeling of the nonwoven fabric.

5: very comfortable and very pleasant soft feeling

4: more comfortable and more favorable soft feeling

3: without unpleasant, but not pleasant, soft feel

2: unpleasant and unpleasant soft feeling

1: very unpleasant, very unpleasant soft feel

(example 1)

As the thermoplastic resin, copolymerized polyethylene terephthalate containing polyethylene glycol having a number average molecular weight of 5500 and a copolymerization amount of 8 wt% (hereinafter, described as "PET-PEG" in table 1 shown below) was used. First, the thermoplastic resin was melted in an extruder and spun from a rectangular spinneret having a spinning temperature of 290 ℃ and an aperture diameter of 0.30mm at a single-hole discharge rate of 0.4 g/min. After the spun sliver was cooled and solidified, the spun sliver was drawn and stretched by compressed air with a jet pressure of 0.10MPa in a rectangular jet, and collected on a moving web to obtain a nonwoven web containing long copolyester fibers. Next, the obtained nonwoven web was thermally bonded by a pair of upper and lower hot embossing rollers consisting of an upper roller and a lower roller. At this time, as the upper roll, an engraved embossing roll made of metal and formed with a water bead pattern of 0.5mm depth and having a bonding area ratio of 16% was used. The lower roll is a pair of upper and lower hot embossing rolls formed of flat metal rolls. The embossing roll was set to a line pressure of 50N/cm and a thermal bonding temperature of 230 ℃. The evaluation results of the obtained spunbonded nonwoven fabric are shown in table 1.

(example 2)

In addition to increasing the web travel speed, the spunbond nonwoven was weighed from 27g/m²Reduced to 15g/m²Except for this, a spunbond nonwoven fabric was obtained in the same manner as in example 1. Evaluation results of the obtained spunbonded nonwoven FabricShown in table 1.

(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 0.5mm to 0.2 mm. The evaluation results of the obtained spunbonded nonwoven fabric are shown in table 1.

(example 4)

A spunbond nonwoven fabric was obtained in the same manner as in example 1, except that the engraving of the upper roll of the heat embossing roll was changed from a water-drop pattern, an engraving depth of 0.5mm, and a bonding area ratio of 16% to a diagonal lattice pattern of 10mm square (10 mm square on each side), a depth of 1mm, and a bonding area ratio of 10%. The evaluation results of the obtained spunbonded nonwoven fabric are shown in table 1.

(example 5)

As the thermoplastic resin, polypropylene (hereinafter, referred to as "PP-EBA" in table 1) to which 0.5 mass% of ethylene bis stearamide having 38 carbon atoms as a lubricant was added was used. First, the thermoplastic resin was melted in an extruder and spun from a rectangular spinneret having a spinning temperature of 230 ℃ and an aperture diameter of 0.30mm, with a single-hole discharge rate of 0.4 g/min. After the spun sliver was cooled and solidified, the spun sliver was drawn and stretched by compressed air with a jet pressure of 0.10MPa in a rectangular jet, and collected on a moving web to obtain a nonwoven web containing long copolyester fibers. Next, the obtained nonwoven web was thermally bonded by a pair of upper and lower thermal embossing rollers consisting of upper and lower rollers. At this time, as the upper roll, an engraved embossing roll made of metal and formed with a water bead pattern of 0.5mm depth and having a bonding area ratio of 16% was used. The lower roll is a pair of upper and lower hot embossing rolls formed of flat metal rolls. The line pressure of the heat embossing roll was set to 50N/cm, and the thermal bonding temperature was set to 130 ℃. The evaluation results of the obtained spunbonded nonwoven fabric are shown in table 1.

(example 6)

A spunbonded nonwoven fabric was obtained in the same manner as in example 1, except that polyethylene terephthalate (hereinafter, referred to as "PET" in table 1) without copolymerized polyethylene glycol was used as the thermoplastic resin. The evaluation results of the obtained spunbonded nonwoven fabric are shown in table 1.

Comparative example 1

A spunbonded nonwoven fabric was obtained in the same manner as in example 5, except that polypropylene (hereinafter, referred to as "PP") to which ethylene bis stearamide was not added was changed as the thermoplastic resin. The evaluation results of the obtained spunbonded nonwoven fabric are shown in table 1.

Comparative example 2

A spunbonded nonwoven fabric was obtained in the same manner as in example 1, except that the cell discharge amount was changed from 0.4 g/min to 0.2 g/min, and the pressure of the compressed air in the ejector was changed from 0.10MPa to 0.05 MPa. The evaluation results of the obtained spunbonded nonwoven fabric are shown in table 1.

[ Table 1]

TABLE 1

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

On the other hand, as shown in comparative examples 1 and 2, the spunbond nonwoven fabric had too high a bending recovery property and too low a tensile elastic modulus, and was poor in soft feeling as a result of sensory evaluation of 3 or less.

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

The present application is based on japanese patent application (japanese patent application 2018-183754) filed on 28/9/2018, and the contents thereof are incorporated herein by reference.

Industrial applicability

The present invention provides a spunbonded nonwoven fabric having a good touch (excellent soft touch).