JP2005187979A - Spunbond nonwoven fabric - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a spunbond nonwoven fabric having both excellent bulkiness and strength. <P>SOLUTION: The spunbond nonwoven fabric is obtained by subjecting a nonwoven fabric obtained by opening and entangling continuous filaments consisting essentially of a polyethylene terephthalate having ≥0.63 intrinsic viscosity, and having 50-300 kg/m<SP>3</SP>bulk density to embossing. The single filament constituting the continuous filaments has 0.5-4 dtex size, ≥4 cN/dtex tensile strength, 40-150% elongation, ≤5% shrinkage in dry air at 180°C, and ≥40Å apparent crystal size ACS(010) in the 010 face. The spunbond nonwoven fabric having ≥2.50 N/5 cm strength per g/m<SP>2</SP>weight in the machine direction, and ≥1.50 N/5 cm strength in the cross direction, or the nonwoven fabric having ≥2,000 g/m<SP>2</SP>×24 hr moisture permeability and ≥10 kPa water resistance (water-resisting pressure) can also be obtained. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a spunbonded nonwoven fabric that retains bulkiness and has improved nonwoven fabric strength.

As a general-purpose product of long-fiber nonwoven fabric having excellent strength, a spunbond nonwoven fabric is known. For example, a method of direct spinning and pulling and entanglement lamination to form a random structure has been proposed (for example, Patent Document 1). This method has good production efficiency, but has a problem of poor mechanical properties.
In order to increase the tensile strength, a method of increasing the density by utilizing the rigidity and heat resistance of liquid crystal polyester has been proposed (for example, Patent Document 2). However, this proposal still has a problem that the bulkiness is inferior. In addition, a spunbonded nonwoven fabric has been proposed in which polyester having a higher intrinsic viscosity is used and the cross section of the fiber is flattened and densified (for example, Patent Document 3). However, even in this proposal, the strength in the vertical direction is improved, but the strength in the horizontal direction is weak and the bulkiness is inferior.
Japanese Patent Publication No. 48-38025 Japanese Patent Laid-Open No. 06-128857 Japanese Patent Laid-Open No. 2001-89963

On the other hand, as a method for imparting bulkiness, a spunbonded nonwoven fabric using a three-dimensional crimp of a composite fiber has been proposed (for example, Patent Document 4). However, although this proposal is bulky, there is a problem that the strength is very inferior. There is a proposal using an olefin-based composite fiber that is a low-density material (for example, Patent Document 5 and Patent Document 6), but the problem of low strength cannot be solved. As another method for imparting bulkiness, there is a proposal of imparting bulkiness by buckling the composite fiber and nonwoven fabric (Patent Document 7). Even with this proposal, the problem of insufficient strength remains even if the bulkiness is satisfactory.
In addition, there is a proposal that balances bulkiness and strength using a hollow cross-section composite fiber (Patent Document 8). Even in this proposal, there is a problem that the strength is not sufficient even though the bulk density is set relatively high.
JP 05-209354 A Japanese Patent Laid-Open No. 10-88460 JP 2001-40531 A JP 2002-69822 A JP 09-13261 A

  In the above-described method, a spunbonded nonwoven fabric excellent in both bulkiness and strength has not been obtained.

  The present invention has been made against the background of the problems of the prior art, and proposes a spunbonded nonwoven fabric excellent in both bulkiness and strength.

As a result of intensive studies to solve the above problems, the present inventors have finally completed the present invention. That is, the present invention has the following configuration.
(A) in intrinsic viscosity continuous fibers mainly composed of polyethylene terephthalate bulk density obtained by open繊交fault of 50kg / m ³ ~300kg / m ³ of 0.63 or more nonwoven single fibers constituting the continuous fibers Has a fineness of 0.5 to 4 dtex, a tensile strength of 4 cN / dtex or more, an elongation of 40% to 150%, a dry heat shrinkage at 180 ° C. of 5% or less, and an apparent crystal size ACS of 010 plane (010) A spunbonded nonwoven fabric characterized by embossing a nonwoven fabric of ≧ 40%.
(B) The spunbonded nonwoven fabric according to (A), wherein the longitudinal strength per unit weight of 1 g / m ² is 2.50 N / 5 cm or more and the lateral strength is 1.50 N / 5 cm or more.
(C) The spunbonded nonwoven fabric is either (A) or (B) having a moisture permeability (moisture permeability) of 2000 g / m ² · 24 hours or more and a waterproof property (water pressure resistance) of 10 kPa or more.

  The spunbonded nonwoven fabric of the present invention increases the molecular weight of polyethylene terephthalate and pulls it at a high speed, thereby promoting orientational crystallization of the fiber and substantially forming a seascore structure while being a single component. By forming a spunbonded nonwoven fabric that improves the rigidity of the components and is bulky and can maintain high strength, it can be inexpensively provided as a nonwoven fabric that is optimal for various applications that require bulkiness and strength. Furthermore, it can also be set as the nonwoven fabric which can be provided to the winding tape for electric wires, a printing base material, a house wrap etc. which require higher strengthening as needed.

Hereinafter, the present invention will be described in detail.
In the present invention, the crystal size of the sheath part crystallized by orientation crystallization is enlarged and the amorphous part of the core part is constrained by the sheath part crystal. It is a spunbonded nonwoven fabric that is capable of being squeezed, bulky and strong.

Macro structural preferred features of the nonwoven fabric of the present invention is a nonwoven fabric having a bulk density of continuous fibers formed by open繊交fault is ^{50kg / m 3 ~300kg / m 3} .
If it is 50 kg / m ³ or less, the strength of the nonwoven fabric becomes insufficient, such being undesirable. If it is 300 kg / m ³ or more, the bulkiness is poor, which is not preferable. Preferred bulk density of the present invention is that the bulkiness request is large is ^{60kg / m 3 ~150kg / m 3} , more preferably ^{80kg / m 3 ~120kg / m 3} . That strong demand is large is 150kg / m ³ ~210kg / m ³ and more preferably from ^{170kg / m 3 ~200kg / m 3} .

  In the nonwoven fabric of the present invention, it is preferable that the constituent long fibers satisfy the following requirements together with the macro structure. That is, the tensile strength of a single fiber composed of polyethylene terephthalate as a main component is 4 cN / dtex or more, the elongation is 40% or more and 150% or less, the dry heat shrinkage at 180 ° C. is 5% or less, and the apparent surface of 010 The crystal size ACS (010) ≧ 40%.

The main component of polyethylene terephthalate in the present invention is a composition containing 90 mol% or more of ethylene terephthalate units, preferably 98% or more, more preferably 99% or more.
The polyethylene terephthalate long fiber constituting the nonwoven fabric of the present invention preferably has an intrinsic viscosity of 0.63 or more in order to maintain mechanical properties. When the intrinsic viscosity is 0.63 or less, the take-up speed that causes orientational crystallization at the time of spinning is high, so that the shrinkage and bulk increase due to the addition of mechanical properties are insufficient in the take-up speed range of 4000 m / min to 5500 m / min. Therefore, it is not preferable. The reason is not clear, but it is presumed that the orientation crystallization becomes insufficient and the binding force of the core portion due to the crystallization of the sheath portion due to the seascore structure is inferior. On the other hand, when the intrinsic viscosity exceeds 1.6, oriented crystallization proceeds excessively at 4000 m / min to 5500 m / min, voids are generated, and the specific gravity is lowered. The preferable intrinsic viscosity of the present invention is 0.68 to 1.4, more preferably 0.70 to 1.2.

The tensile strength in the single fiber of the fiber which comprises the nonwoven fabric of this invention is 4 cN / dtex or more. If it is 4 cN / dtex or less, the strength of the nonwoven fabric is inferior. A preferable tensile strength is 4.5 cN / dtex or more, more preferably 5 cN / dtex or more. Although an upper limit is not specifically limited, 8-9 cN / dtex becomes an upper limit substantially from the required elongation in this invention.
The elongation of the fibers constituting the nonwoven fabric of the present invention is 40% or more and 150% or less. If it is 40% or less, the nonwoven fabric is inferior in flexibility, which is not preferable. An elongation of 150% or more is not preferable because the dimensional stability of the nonwoven fabric is poor. The preferable elongation of the present invention is 50% to 120%, and the more preferable elongation is 60 to 100%.
The shrinkage rate at 180 ° C. dry heat in the single fibers of the fibers constituting the nonwoven fabric of the present invention is 5% or less. Those that have reached 5% or less have heat resistance and good mechanical property retention even when subjected to thermal history. The reason for this is not clear, but at the stage where orientation crystallization occurs, oriented crystallization on the fiber surface, where the extensional viscosity becomes high, proceeds from the inner layer, so a seascore structure is formed, and crystallization of the sheath portion proceeds further, causing the core portion to crystallize. It can be inferred that this is because the movement of the amorphous material is restrained. If the shrinkage rate at a dry heat of 180 ° C. is 5% or more, if a thermal history is received during the production process, the mechanical properties are deteriorated due to the shrinkage and the nonwoven fabric is greatly deformed, resulting in poor product finish. In the present invention, the preferred shrinkage at 180 ° C. dry heat is 5% or less, more preferably 3% or less.

The apparent crystal size (hereinafter abbreviated as ACS (010)) of the 010 plane of the fibers constituting the nonwoven fabric of the present invention is preferably 40 mm or more. If it is less than 40%, it is not preferable to receive a thermal history such as hot embossing because the bulk is reduced or the mechanical properties are lowered even if the mechanical properties are satisfied, and the bulkiness and nonwoven fabric strength of the final product are lowered. The reason for this is not clear, but the larger the crystal, the higher the compressibility due to the rigidity of the fiber and the better the bulk retention, and the sheath crystal restrains the movement of the core amorphous and the mechanical properties decrease due to shrinkage. It is analogized that it suppresses. The preferable ACS (010) of the present invention is 43 mm or more, more preferably 46 mm or more.
The specific gravity of the fibers constituting the nonwoven fabric of the present invention is not particularly limited, but is preferably 1.36 or more. In the case of 1.36 or less, even if a huge crystal is formed, if the thermal history is received, the deterioration of the mechanical properties may be increased, which is not preferable. The reason for this is not clear, but since the degree of crystallinity is low, it is presumed that the amorphous restraint due to crystals becomes insufficient and the mechanical properties deteriorate. The more preferable specific gravity of the present invention is 1.38 or more.

If the non-woven fabric of the present invention satisfies the above-mentioned requirements, if the basis weight is 20 g / m ² or more, the longitudinal strength per 1 g / m ² basis weight is 2.50 N / 5 cm or more, and the lateral strength is 1.50 N / 5 cm. That's it. Thus, the basis weight is less than 20 g / m ^2, depending on post-processing conditions, strong longitudinal per basis weight 1 g / m ² is 2.50N / 5cm or more, transverse strength is reaches more than 1.50N / 5cm In some cases, the post-processing conditions are adjusted, and the longitudinal strength per unit weight of 1 g / m ² is preferably 2.50 N / 5 cm or more and the lateral strength is 1.50 N / 5 cm or more.

Although the fineness of the single fiber which comprises this invention nonwoven fabric is not specifically limited, In order to satisfy lightweight and bulkiness and strong maintenance simultaneously, it is preferable that the fineness of a single fiber shall be 0.5 dtex-4 dtex. If the single fiber fineness is less than 0.5 dtex, the bulkiness is inferior and may not be preferable. If it exceeds 4 dtex, high strength may not be maintained due to a decrease in the number of fibers in the nonwoven fabric. The more preferable single fiber fineness of the present invention is 1 dtex to 3 dtex.
The thickness of the nonwoven fabric of the present invention is not particularly limited, but it is preferably 0.05 mm or more when used as a printing substrate or house wrap that is lightweight and requires strength and tension retention. When the bulk density is 100 kg / m ³ or less, the tension is insufficient when the thickness is 0.05 mm or less. A more preferable thickness in the present invention is 0.07 mm or more. Since the upper limit is determined by the application, it is desirable that the upper limit is laminated to a desired thickness and a predetermined thickness is obtained by the entanglement process.
The entangled form of the nonwoven fabric of the present invention is not particularly limited, but as the entanglement means, embossing that is lightweight and can easily impart bulkiness and strength retention is preferable. The embossing is preferably plain processing for a filter that requires bulkiness, ventilation and water permeability, and for a printing substrate that requires surface smoothing. Examples of the processing method capable of maintaining the entangled form maintaining the bulkiness include laminating, needle punching, and resin processing.
When the nonwoven fabric of the present invention is used for house wrap applications, the moisture permeability (moisture permeability) should be 2000 g / m ² · 24 hours or more and the waterproofness (water pressure resistance) should be 10 kPa or more by laminating or the like, if desired. preferable. Even in the case of embossing alone, preferable moisture permeability and waterproofness can be imparted by setting the bulk density to, for example, 180 kg / m ³ or more.
The moisture permeability is more preferably 2600 / m ² · 24 hours or more, and further preferably 31002600 / m ² · 24 hours or more.

Below, an example of the manufacturing method of this invention nonwoven fabric is shown.
It is recommended that polyethylene terephthalate having an intrinsic viscosity of 0.65 or more and 1.80 or less is vacuum-dried and subjected to spinning at a moisture content of 0.003% by weight or less. When the moisture content is 0.03 or more, hydrolysis due to moisture occurs, and a fiber having an intrinsic viscosity of 0.63 or more necessary for the present invention may not be obtained. A preferable moisture content in the present invention is 0.002% by weight or less. When the drying process is omitted and moisture is removed from the vent at the spinning stage, a method of removing moisture at a high vacuum immediately before and after being melted by an extruder is recommended. In addition, when flame retardancy, light resistance, colorability, etc. are desired as functions necessary for the nonwoven fabric of the present invention, PET modified by addition of a modifier or the like by post-kneading is used. be able to.

  Next, melt spinning is performed by a conventional method. The spinning temperature is recommended to be 15 ° C to 40 ° C higher than the melting point of polyethylene terephthalate. A temperature higher by 25 ° C. to 35 ° C. is recommended. If the intrinsic viscosity is low, it is recommended to set a low spinning temperature, and if the intrinsic viscosity is high, it is recommended to set a high spinning temperature. The molten polymer is discharged from the orifice. The discharge amount is preferably an optimum amount that achieves a desired fineness according to the take-up speed. In the present invention, since the preferred fineness is 1 dtex to 4 dtex, when the take-up speed is 5000 m / min, the discharge rate per single hole is preferably 0.5 g / min to 2.0 g / min. As the nozzles to be ejected, a necessary number of small nozzles in multiple rows may be installed, or a single nozzle having multiple rows of holes may be used. The discharged melted filament is thinned while being cooled and taken out. In the present invention, the orientation crystallization start rate is lowered, the orientation crystallization is further advanced and the take-up is performed, so that the crystal size is grown to a low size, and the necessary mechanical properties are imparted to the filaments with low shrinkage. There is a need. In order to provide the preferable structure formation of the present invention, it is preferable to cool the filament at a temperature of 40 ° C. or lower. When the temperature is 80 ° C. or higher, the melted filaments are hardly cooled, and the orientation crystallization rate is increased, which may not be preferable.

In the spunbonding method, a web is formed by picking up with an ejector having an aspirator function, and shaking on a transport net to open and laminate the fiber arrangement in a random state. At this time, the fiber may be delayed and recovered within the elastic recovery limit, resulting in deterioration of mechanical properties. For this reason, in the present invention, a method of fixing the web form by immediately suppressing delayed recovery of the spread-laminated web is strongly recommended. Specifically, a method of pinching and fixing with a take-off net and a method of fixing with a pressing roller can be exemplified. The amount of fibers to be shaken off is adjusted according to the take-up net speed so as to obtain a desired basis weight. In the case where the number of spun fibers is constant, when the take-up net speed is increased, the opened fibers tend to be more likely to be arranged in the net traveling direction (hereinafter abbreviated as MD). In such a case, it is possible to adjust the random state by increasing the number of fibers to be shaken off, and the productivity is further improved. On the contrary, it is preferable to increase the net speed in the wire wound tape that requires particularly strong strength in the MD direction. In the process of forming the take-up web, it is necessary to consider necessary thickness adjustment. When improving the handleability of the web by pre-embossing or the like, it is important not to heat and set more than the required bulk density.
The laminated web is then embossed continuously or discontinuously. The embossed shape is processed by selecting an optimum dot shape, density, or plain shape according to the desired function of the desired nonwoven fabric surface. In general, the embossing temperature is suitably 220 ° C. to 250 ° C. for PET and the linear pressure is suitably 100 Nf to 300 Nf.
The obtained embossed nonwoven fabric of the present invention can be provided as various base fabrics as they are. If necessary, it is then applied to a printing substrate or house wrap using the nonwoven fabric of the present invention as a base fabric by resin coating or laminating.
The spunbonded nonwoven fabric of the present invention thus obtained can be provided at a low cost as a nonwoven fabric that is optimal for base fabrics for various uses that require mechanical properties and bulkiness.
In addition, the illustration in this invention is not limited to these.

  Examples of the present invention are shown below. The present invention is not limited to the examples.

  Next, the present invention will be specifically described with reference to examples and comparative examples. The characteristic values in the examples and comparative examples were measured by the following methods.

<Apparent crystal size of 010 plane: ACS (010)>
The apparent crystal size of the 010 plane of the fiber was calculated from the half-value width of the diffraction intensity of the equatorial diffraction curve in the wide-angle X-ray diffraction diagram using the Serrer equation [For details, see “X-ray crystallography” published by Maruzen Co., Ltd. (See Supervision))]. The Scherrer equation is expressed by the following equation.

<Fineness of single fiber>
Measured according to JIS-L1015 (1999).

<Tensile strength (tensile strength) and elongation (elongation) of single fiber>
Measured according to JIS-L1015 (1999).

<Specific gravity>
A density gradient tube made of n-heptane and carbon tetrachloride is prepared, and a sufficiently degassed sample is placed in a density gradient tube adjusted to 30 ° C. ± 0.1 ° C. After leaving for 5 hours, the density gradient tube The value obtained by reading the position of the sample on the scale of the density gradient tube is converted into a specific gravity value from the density gradient tube scale by the standard glass float to the specific gravity calibration graph, and measured at n = 4. In principle, the specific gravity value is read to 4 digits after the decimal point.

<180 ° C dry heat shrinkage of single fiber>
It measures by processing at 180 degreeC of dry heat based on JIS-L1015 (1999).

<Thickness>
Measured according to JIS-L1906 (2000).

<Weight per unit (mass per unit area)>
Measured according to JIS-L1906 (2000).

<Bulk density>
From the thickness (t: m) measured according to JIS-L1906 (2000) and the mass per unit area (m2), the apparent density (ρ) is determined by the following formula in units of kg / m ³ .
ρ = m2 / t

<Tensile strength and elongation of nonwoven fabric>
Measured according to JIS-L1906 (2000).

<Strength per 1 g / m ² basis weight of nonwoven fabric>
A value obtained by dividing the tensile strength (W) measured according to JIS-L1906 by the basis weight measured according to JIS-L1906.

<Moisture permeability (moisture permeability)>
Measured in accordance with JIS-JIS-L1099 [4.1.1 (Method A-1) using calcium chloride, φ70 mm].

<Waterproof (water pressure resistant)>
Measured according to [5.1 B method (high water pressure method)] of JIS-L1902.

(Example 1)
Polyethylene terephthalate (hereinafter abbreviated as PET) dried to a moisture content of 0.002% by weight and having an intrinsic viscosity of 0.75 is spun at a spinning temperature of 285 ° C. from a nozzle with an orifice diameter of 0.2 mm at a single hole discharge rate of 1 g / min. Then, while cooling the air at 25 ° C. from 50 mm below the nozzle at a wind speed of 0.5 m / sec, the air is sucked by the ejector installed at a point 1.2 m below the nozzle and sucked at a speed of 5000 m / min. The fiber bundle was spun off and laminated on the surface of the take-up net moving at a speed of 30 m / min, 1.5 m. The web laminated on the net surface was continuously pre-compressed with a temporary pressing roller and wound around a take-up roller in order to suppress the elastic recovery of the fiber continuously.
The obtained temporary pressed spunbonded nonwoven fabric has a thickness of 0.45 mm, an apparent bulk density of 100 kg / m ³ , a fiber arrangement is in a random form, and the single fiber characteristics of the long fibers that are formed are a fineness of 2 dtex, a tensile strength It was 5.0 cN / dtex, an elongation rate of 85%, a dry heat shrinkage rate of 180 ° C. of 3.4%, an ACS (010) 47%, a specific gravity of 1.38, and an intrinsic viscosity of 0.69.
Next, a spunbonded nonwoven fabric obtained by embossing the wound nonwoven fabric with a 4 mm pitch dot embossing roller at 240 ° C. with a linear pressure of 2 Nf was obtained.
The thickness of the obtained embossed spunbonded nonwoven fabric is 0.30 mm, basis weight 45 g / m ² , apparent bulk density 150 kg / m ³ , longitudinal direction (MD) tensile strength 230 N / 5 cm (5.1 N / 5 cm per basis weight) ), The elongation was 30%, the tensile strength in the transverse direction (CD) was 130 N / 5 cm (2.9 N / 5 cm per unit weight), and the elongation was 28%.
Next, the embossed spunbonded nonwoven fabric was obtained by extruding molten polyethylene added with inorganic fine particles into a film shape from a T-die onto the nonwoven fabric and solidifying it by pressing with a compression roller to obtain a wrap material laminated to the nonwoven fabric. There was no problem in the processing process.
The obtained wrapping material had a thickness of 0.41 mm, moisture permeability (moisture permeability) of 3500 g / m ² · 24 hours, water resistance (water pressure resistance) of 16 kPa and excellent moisture permeability and waterproof performance. Furthermore, the tension of the important sheet at the time of construction of the lapping material was also good.

(Example 2)
Using a PET with an intrinsic viscosity of 0.85, except that the spinning temperature was 290 ° C. and the single-hole discharge rate was 0.5 g / min, the thickness of the temporary pressed spunbonded nonwoven fabric obtained in the same manner as in Example 1 was 0.3 mm, The apparent bulk density is 90 kg / m ³ , the fiber arrangement is in a random form, and the single fiber characteristics of the long fibers to be formed are a fineness of 1 dtex, a tensile strength of 4.8 cN / dtex, an elongation of 62%, and 180 ° C. The dry heat shrinkage ratio was 2.4%, ACS (010) 51 kg, specific gravity 1.39, and intrinsic viscosity 0.75.
Next, an embossed spunbonded nonwoven fabric was obtained in the same manner as in Example 1 except that a plain embossed roller was used for the wound nonwoven fabric.
The thickness of the resulting embossed spunbonded nonwoven fabric is 0.15 mm, the basis weight is 30 g / m ² , the apparent bulk density is 200 kg / m ³ , and the tensile strength in the machine direction (MD) is 106 N / 5 cm (3.5 N / 5 cm per unit weight). ), Elongation 21%, transverse direction (CD) tensile strength 61 N / 5 cm (2.0 N / 5 cm per unit weight), elongation 25%.
As a result of evaluating the moisture permeability and waterproofness of the obtained embossed spunbond nonwoven fabric, it has excellent moisture permeability and waterproof performance such as moisture permeability (moisture permeability) of 10900 g / m ² · 24 hours and water resistance (water pressure resistance) of 11 kPa. It was. Furthermore, the tension of the important sheet at the time of construction of the lapping material was also good. Further, as a result of evaluating the printability, the ink ride was good and there was no bleeding.

(Comparative Example 1)
A temporary sample obtained in the same manner as in Example 1 except that PET with an intrinsic viscosity of 0.63 was used, the single-hole discharge rate was 0.9 g / min, the take-up speed was 4500 m / min, and the take-up net speed was changed for weighting. The thickness of the pressed spunbonded nonwoven fabric is 0.34 mm, the apparent bulk density is 130 kg / m ³ , the fiber arrangement is a random form, and the single fiber characteristics of the long fibers that are formed are fineness 2 dtex, tensile strength 2.8 cN / It was dtex, elongation rate of 192%, dry heat shrinkage of 19.6% at 180 ° C., ACS (010) 19%, specific gravity of 1.35, and intrinsic viscosity of 0.57.
Next, the wound nonwoven fabric was treated in the same manner as in Example 1 to obtain an embossed spunbond nonwoven fabric.
The thickness of the obtained embossed spunbonded nonwoven fabric is 0.16 mm, the basis weight is 45 g / m ² , the apparent bulk density is 280 kg / m ³ , and the tensile strength in the machine direction (MD) is 120 N / 5 cm (2.6 N / 5 cm per unit weight). ), The elongation was 28%, the tensile strength in the transverse direction (CD) was 75 N / 5 cm (1.6 N / 5 cm per unit weight), and the elongation was 25%.
Next, a wrap material was obtained in the same manner as in Example 1. Shrinkage deformation occurred in the processing process, and the finish was somewhat poor. The obtained wrap material has a thickness of 0.24 mm, moisture permeability (moisture permeability) of 2500 g / m ² · 24 hours, water resistance (water pressure resistance) of 14 kPa and moisture permeability waterproof performance, At times, important sheet tension is poor, which is undesirable as a wrapping material.

(Comparative Example 2)
The thickness of the temporary press spunbond nonwoven fabric obtained in the same manner as in Comparative Example 1 is 0.41 mm except that the single hole discharge rate is 1.2 g / min, the take-up speed is 6000 m / min, and the take-up net speed is changed for weighting. The apparent bulk density is 110 kg / m ³ , the fiber arrangement is in a random form, and the single fiber characteristics of the long fibers to be formed are a fineness of 2 dtex, a tensile strength of 3.9 cN / dtex, an elongation of 116%, and 180 ° C. The dry heat shrinkage rate was 5.0%, ACS (010) 39%, specific gravity 1.36, and intrinsic viscosity 0.58.
Next, the wound nonwoven fabric was treated in the same manner as in Example 1 to obtain an embossed spunbond nonwoven fabric.
The thickness of the resulting embossed spunbonded nonwoven fabric is 0.21 mm, basis weight 45 g / m ² , apparent bulk density 215 kg / m ³ , longitudinal direction (MD) tensile strength 128 N / 5 cm (2.8 N / 5 cm per unit weight) ), The elongation was 26%, the tensile strength in the transverse direction (CD) was 79 N / 5 cm (1.7 N / 5 cm per unit weight), and the elongation was 25%.
Next, a wrap material was obtained in the same manner as in Comparative Example 1. Some shrinkage deformation occurred in the processing process. The obtained wrapping material has a thickness of 0.29 mm, moisture permeability (moisture permeability) of 3000 g / m ² · 24 hours, water resistance (water pressure resistance) of 15 kPa and moisture permeability and waterproof performance. At times, the tension of the important sheet is slightly poor, and it is not optimal as a wrapping material.

  As is clear from Examples 1-2 and Comparative Examples 1-2, the spunbonded nonwoven fabric of the present invention increases the molecular weight of polyethylene terephthalate and promotes oriented crystallization of fibers by pulling at high speed. A spunbonded nonwoven fabric that is substantially single-component, yet has a seascore structure, improves the rigidity of the sheath component, is bulky, and can maintain high strength. It can be provided at a low cost as a non-woven fabric optimal for the application. Furthermore, it can also be set as the nonwoven fabric which can be provided to the winding tape for electric wires, a printing base material, a house wrap etc. which require higher strengthening as needed.

  The spunbonded nonwoven fabric of the present invention increases the molecular weight of polyethylene terephthalate and pulls it at a high speed, thereby promoting orientational crystallization of the fiber and substantially forming a seascore structure while being a single component. By forming a spunbonded nonwoven fabric that improves the rigidity of the components and is bulky and can maintain high strength, it can be inexpensively provided as a nonwoven fabric that is optimal for various applications that require bulkiness and strength. Furthermore, it can also be set as the nonwoven fabric which can be provided to the winding tape for electric wires, a printing base material, a house wrap etc. which require higher strengthening as needed.

Claims (3)

In intrinsic viscosity continuous fibers mainly composed of polyethylene terephthalate bulk density obtained by open繊交fault of 50kg / m ³ ~300kg / m ³ of 0.63 or more nonwoven single fibers constituting the continuous fibers fineness 0 .5 dtex to 4 dtex, tensile strength of 4 cN / dtex or more, elongation of 40% or more and 150% or less, dry heat shrinkage at 180 ° C. of 5% or less, apparent crystal size ACS (010) ≧ 40 mm at 010 plane A spunbond nonwoven fabric characterized by embossing a nonwoven fabric. The spunbond according to claim 1, wherein embossing is applied to a nonwoven fabric having a longitudinal strength per unit weight of 1 g / m ² of 2.50 N / 5 cm or more and a transverse strength of 1.50 N / 5 cm or more. Non-woven fabric. 3. The spunbonded nonwoven fabric according to claim 1, wherein the moisture permeability (moisture permeability) is 2000 g / m ² · 24 hours or more, and the waterproofness (water pressure resistance) is 10 kPa or more.