JP3445539B2 - Spunbond nonwoven - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a spunbonded non-woven fabric which is useful in the fields where the surface smoothness of the non-woven fabric and the thin and strong tensile strength are required, for example, in the field of electric wire pressing tape, printing substrate and the like. .

[0002]

2. Description of the Related Art In general, performances particularly required for electric wire pressing and winding tapes are tensile strength, surface fineness and surface smoothness that facilitate peeling from a polyethylene sheath material, and the economy of increasing winding amount. For the above reasons, it is thin and strong. The surface smoothness of the non-woven fabric is an important performance from the viewpoints of sharpness of printing, uniform adhesion of ink and economical efficiency.

Conventionally, as a method for obtaining a polyethylene terephthalate spunbonded nonwoven fabric suitable for an electric wire holding and winding tape, JP-A-55-32342 and 57-57.
-56564 discloses that in addition to the use of flat cross section yarns,
A method using a combination of adhesives, so-called resin processing, is disclosed. As described above, conventionally, in a polyethylene terephthalate spunbonded nonwoven fabric, in order to obtain a thin and strong nonwoven fabric having a smooth surface, it is necessary to use resin processing together because the strength and smoothness are insufficient only by joining by thermocompression bonding. It was That is, a non-binder type non-binder type which does not use resin processing together and has a smooth surface and is thin and strong has not been known. As a result, the cost has been increased by processing the resin. In addition, the resin-processed non-woven fabric is limited in recycling to the raw material resin.

[0004]

As described above, in the conventional technique, resin processing is required to obtain a thin and strong non-woven fabric having a smooth surface, and as a result, the manufacturing cost is pressed. An object of the present invention is to economically provide a thin and strong non-woven fabric having a smooth surface only by thermocompression bonding without resin processing.

[0005]

Means for Solving the Problems The present inventors have completed the present invention as a result of earnest research on a non-binder type that does not undergo resin processing, in other words, a thin and strong non-woven fabric only by thermocompression bonding. That is, the present invention, the no-binder type junction fiber維間is performed only by heat and pressure
Polyethylene terephthalate fiber spunbonded nonwoven fabric
There is polyethylene terephthalate that constitutes the nonwoven fabric.
The reduced viscosity of the bets textiles (.eta.sp / c) is 0.67 or more, fineness of 3.3 dtex or less, the flatness of the cross section of the fiber is not less than 1.5, and the thickness of the nonwoven fabric (1) The tensile strength of the nonwoven fabric satisfies the formula (1)
It is 1,274 N / (3 cm width) or more per mm), and is a spun bond nonwoven fabric characterized by the above-mentioned.

[0006]

[Equation 2]

[0007] In the nonwoven fabric of the present invention, it is preferable flatness of the cross section of polyethylene te <br/> Refutare preparative textiles are on 2.0 or more. Hereinafter, the present invention will be described in more detail.
Spunbonded nonwoven fabric of the present invention, the reduced viscosity of the polyethylene terephthalate textiles constituting the heated crimping nonwoven (ηsp / c) is 0.67 or more nonwoven. When the reduced viscosity of the fibers constituting the non-woven fabric after thermocompression bonding is 0.67 or more, coupled with the requirement that the fineness of the fibers is 3.3 decitex or less, high tensile strength and tearing can be achieved only by thermocompression bonding without using a binder. A non-woven fabric satisfying the strength at the same time can be obtained. Since polyethylene terephthalate is thermally deteriorated in the melt spinning process and thermocompression bonding process to reduce the reduced viscosity of the fiber, in order to reduce the reduced viscosity of the fiber constituting the non-woven fabric after thermocompression bonding to 0.67 or more, the reduction of the raw material chips It is necessary to properly select one with high viscosity.

If the reduced viscosity of the fibers constituting the nonwoven fabric after thermocompression bonding is less than 0.67, a nonwoven fabric having high tenacity cannot be obtained. Therefore, it is necessary to jointly bond the fibers by resin processing. Non-woven fabric of the present invention, the fineness of the polyethylene terephthalate textiles constituting the nonwoven fabric is 3.3 dtex or less. When the fineness is more than 3.3 decitex, thermocompression bonding becomes difficult, and it becomes difficult to obtain a high-strength nonwoven fabric only by thermocompression bonding. Therefore, it is necessary to jointly bond the fibers by resin processing.

[0009] The nonwoven fabric of the present invention, the flatness of the cross section of polyethylene terephthalate <br/> rate textiles is 1.5 or more. Flatness is representative of the degree flat cross section of a polyethylene terephthalate textiles of the present invention, a flat yarn the greater the flatness. The flat shape means, for example, JP-A-55-
As described in No. 32342, the ratio of the major axis to the minor axis in the cross section is 1.5 or more, and the ratio of the major axis to the minor axis (major axis / minor axis) is defined as the flatness. .

[0010] Spunbond nonwoven fabric of the present invention, the flatness of the cross section of polyethylene terephthalate textiles constituting the nonwoven fabric is 1.5 or more of the flat, in order to obtain a thinner nonwoven fabric flatness 2.0 The above is preferable. When the flatness is less than 1.5, it is difficult for the nonwoven fabric to become thin even when heated and compressed, and sufficient surface smoothness is achieved to improve the peelability from the polyethylene sheath material required for wire holding tape. However, the strength per unit thickness is also reduced.

In the spunbonded nonwoven fabric of the present invention, the thickness of the nonwoven fabric is a value represented by the formula (1).

[0012]

[Equation 3]

The thickness of the non-woven fabric affects the denseness of the non-woven fabric and the smoothness of the surface, and particularly the surface smoothness is related to the releasability from the polyethylene sheath material, for example, in the wire pressing tape application. If the peelability from the polyethylene sheath material is good, it becomes easy to collect the coated electric wire and recycle the polyethylene sheath material, polyethylene terephthalate and the electric wire. In the spunbonded nonwoven fabric of the present invention, when the thickness of the nonwoven fabric satisfies the expression (1), the peelability from the polyethylene sheath material also becomes good.
When the thickness of the non-woven fabric exceeds the value represented by the formula (1), the peelability from the polyethylene sheath material becomes insufficient.

In the wire holding tape application, when the thickness of the non-woven fabric is thin, the amount of polyethylene sheath material used can be reduced, and the amount of tape can be increased even with the same tape winding diameter. There is an effect from.
Spunbonded nonwoven fabric of the present invention, it flatness in cross section of a polyethylene terephthalate <br/> rate textiles it is 1.5 or more, and reduced viscosity of the fiber is 0.67 or more, fineness of the fibers Is 3.3 dtex or less and the thickness of the nonwoven fabric satisfies the formula (1), which is unprecedented.
A non-binder type non-woven fabric that is thin and strong and has excellent peelability from a polyethylene sheath material is achieved.

[0015]

[Equation 4]

That is, as shown in the examples, in the range satisfying the above conditions, exfoliation from a polyethylene sheath material is excellent without resin processing, and tensile strength (N / 3 cm) per thickness of nonwoven fabric (1 mm). Is a high-strength nonwoven fabric of 1,274 or more. For example, the flatness of 1.5 or more, even more reduced viscosity 0.67 Pollet Chi terephthalamide Talay preparative textiles nonwoven,
When the fineness of the fiber exceeds 3.3 decitex, it becomes impossible to secure the tensile strength and the releasability from the polyethylene sheath material only by thermocompression bonding.

[0017] The nonwoven fabric of the present invention, a polyethylene terephthalate <br/> rate Textile partially thermocompression bonding, a nonwoven fabric obtained by further heating compression. Usually, the fiber web is passed between a pair of heated and pressurized embossing rolls and a flat roll to bond the fibers. It is no exaggeration to say that the final physical properties of the non-woven fabric are determined by this partial heating and pressure bonding. The area of each crimping point forming the embossed pattern and the arrangement / arrangement of crimping points can be arbitrarily selected, but the embossing rate (crimping area rate) is preferably 6% or more and 40% or less. The strength of the nonwoven fabric decreases as the embossing rate decreases, and if it exceeds 40%, the nonwoven fabric tends to become paper-like and the tear strength tends to decrease.

After the partial heating and pressure bonding, the nonwoven fabric is usually passed between a pair of heated and pressurized flat rolls in order to impart surface smoothness and the like. In order to reduce the thickness and ensure surface smoothness without impairing the basic physical properties such as tensile strength, reduced viscosity and tear strength, it is generally necessary to heat and compress at a temperature lower than the temperature for partial heating and compression bonding. Although preferable, the conditions for heat compression can be arbitrarily selected depending on the required properties of the finally obtained nonwoven fabric.

In producing the nonwoven fabric of the present invention, polyethylene terephthalate is copolymerized with various modifiers such as flame retardants and antistatic agents, and various additives,
For example, pigments, weathering agents, antioxidants, etc. may be added. In the production of a nonwoven fabric, various additives may be added to the polyethylene terephthalate chips in the form of a masterbatch and mixed in a usual melt spinning stage. Spinneret used for spinning polyethylene <br/> Terefutare DOO textiles can be selected from those employed in conventional melt-spinning method.
Similarly, spunbond manufacturing method, for example, spun form a rectangular integrated spinneret scheme or individual spinneret system, traction form roll traction system and high-speed air stream traction system, distributed system is triboelectrification scheme or corona charging scheme, The webbing mode is a net collecting method or a drum collecting method, and can be arbitrarily selected from manufacturing methods such as a single-layer web and a plurality of multi-layer laminated webs.

[0020]

EXAMPLES The present invention will be specifically described below with reference to Examples and Comparative Examples, but the present invention is not limited thereto. The evaluation methods for the nonwoven fabrics used in the examples and comparative examples of the present invention are as follows. (1) sampling the nonwoven fabric piece from any site of the reduced viscosity (.eta.sp / c) nonwoven, condition :( concentration) 1 g / 100 ml (temperature at tetrachloroethane / phenol weight mixed solvent) 35 ° C. in a reducing viscosity
The degree (ηsp / c) is measured.

(2) Fineness Set so that the cut surface of the test piece sampled from an arbitrary position of the non-woven fabric can be observed, and set in an optical microscope equipped with a digital micrometering eyepiece device, and it is almost transverse to the fiber axis. The lengths of the major axis and the minor axis of the fiber cross section are measured for 20 arbitrary fibers cut at right angles, the cross-sectional areas of the respective fibers are determined, and the values are averaged to calculate the cross-sectional area of the fibers.
The fiber density is 1.38 g / cm ³ , and the length is 1,000.
Calculate the weight in m.

The digital type microscopic eyepiece device used for the measurement is a model OSM-D2 manufactured by Olympus Optical Co., Ltd.
The minimum reading unit is 0.01 μm (objective lens: 100
X). Dtex = fiber cross section (cm ²⁾ × 100,000
(Cm) × 1.38 (g / cm ³ ) × 10 (3) Flatness It is calculated using the values of the lengths of the major axis and the minor axis obtained in the measurement of the fineness in (2) above. Flatness = major axis length / minor axis length

(4) Thickness A constant load of 9,800 N / m ^{2 is} applied every 5 cm in the width direction of the sample.
The average value of the thickness measured in the state of applying. The measurement was performed with a peacock thick type (R1-B type). (5) From the tensile strength nonwoven fabric, a sample having a width of 3 cm and a length of 20 cm and a sample having the same size in the orthogonal direction at the midpoint of the longitudinal direction of the sample are sampled at a rate of 1 point per 20 cm of the width of the nonwoven fabric. Grasping this sample in a constant-speed extension type tensile tester 10 cm long
Then, a load is applied at a pulling speed of 30 cm / min until the test piece is cut. The tensile strength (N / 3 cm width) is obtained by obtaining the average value of the strengths of the test pieces under maximum load.

(6) Tensile strength per 1 mm of thickness Calculated by proportional calculation from the thickness calculated by the method (4) and the tensile strength measured by the method (5). Tensile strength per 1 mm of thickness = Tensile strength x (1000 /
Thickness (μm)) (7) A sample having a width of 6.5 cm and a length of 10 cm from the tear strong nonwoven fabric and a sample having the same dimension in the direction orthogonal to the sample at the midpoint in the longitudinal direction of the sample, one point per 20 cm width of the nonwoven fabric. To be collected. Using this sample, the JIS general fabric test method (L1096) 6.15.5D method (pendulum method) is used for measurement. The average value of those values is defined as the tear strength (N).

(8) Sheath releasability (a) Three non-woven fabric sample pieces (60 mm × 60 mm) are prepared. (B) A 1 mm-thick polyethylene sheet (60 mm × 60 mm thick) obtained by press-molding the above-mentioned nonwoven fabric, superposed with a metal plate and applied with a load of 2 kg. (C) Preheated at an atmospheric temperature of 200 ° C. for 1 hour or more. Set the test body adjusted in (b) in a constant temperature bath and leave it for 10 minutes (d) Remove the load of 2 kg, remove from the constant temperature bath, and leave it at room temperature (e) Nonwoven fabric sample piece and polyethylene sheet (F) The degree of adhesion of the fibers of the non-woven fabric on the polyethylene sheet is observed, and the grade is evaluated by comparing with the grade sample.
(A grade of 3.5 or higher is considered as good sheath releasability) Grade 5: Complete peeling grade 4: Some sticking grade 3.5: Dozens sticking grade 3 (limit): Dozens sticking below limit: (9) Surface roughness (center line average roughness: Ra) A sample with a size of about 10 cm x 10 cm was sampled from an arbitrary position on the nonwoven fabric, and a surface roughness profile measuring device: Surfcom 1
It measures with 10A (made by Tokyo Seimitsu Co., Ltd.). The measurement is performed on the front surface and the back surface of the non-woven fabric, and the maximum value among them is taken as the surface roughness.

[0026]

Examples 1 to 7, 9, 10 and Comparative Examples 1 to 8 1.2 m wide rectangular spinneret with a nozzle cross section having a width of 1.0 mm and a thickness of 0.1 mm and a total of 2,214 nozzles in a rectangular cross section. Was used. In each of the examples and comparative examples, raw material chips of polyethylene terephthalate having different reduced viscosities were used , and melt extrusion was performed while changing the discharge amount per spinning nozzle. 0.7 extruded long fiber groups respectively dtex, 1.2 dtex, 2.2 dtex, traction at a high speed air stream such that 3.9 decitex as 3.3 dtex and Comparative Examples, capturing the wire mesh net Collected to form a web.

The web was partially thermocompressed between a pair of textured pattern embossing (compression area ratio: 22.0%) rolls and a flat roll to produce a nonwoven fabric having a basis weight of 45 g / m ² .
Table 1 shows the results of measuring various physical properties of the obtained nonwoven fabric. Regarding the non-woven fabric having a fineness of 3.9 decitex as a comparative example, the temperature and the pressure of the partial thermocompression bonding were changed within the range of the reduced viscosity of 0.66 to 0.72, but the fiber bonding was insufficient only by the partial thermocompression bonding. The fluffing did not stop and the tensile strength was not improved.

[0028]

EXAMPLES 11 to 19 and Comparative Examples 9 to 12] Examples and
In the comparative example, raw material chips of polyethylene terephthalate having different reduced viscosities were used and the shape of the spinneret nozzle was 1.0.
mm, 0.1 mm thick rectangular cross-section, total of 2,21 nozzles
Melt extruded from a 1.2 m wide rectangular spinneret having 4 pieces, and pulled by a high-speed air stream at a spinning speed of 4,500 m / min to obtain 2.0.
A decitex continuous filament web was formed on a wire mesh net. This fibrous web is partially thermocompressed at a linear pressure of 294 N / cm between a pair of texture pattern embossing (compression area ratio: 22.0%) rolls and a flat roll, and a fabric weight 35, 40,
Non-woven fabrics of 45, 60 and 70 g / m ² were produced, and then passed through a pair of flat rolls heated to 215 ° C. and pressed with a linear pressure of 245 N / cm to produce a non-woven fabric. Table 2 shows the results of measuring various physical properties of the obtained nonwoven fabric.

As Comparative Examples, Comparative Examples 9 and 10 were the same as Examples 11 to 19 except that the raw material chips had different viscosities and the spinneret nozzle shape was 0.25 mmφ. It was manufactured and evaluated. The results are shown in Table 2. In Comparative Example 11 and Comparative Example 12, a non-woven fabric having a basis weight of 41 g / m ² and only partial thermocompression bonding was manufactured under the conditions of Comparative Example 9 and Comparative Example 10.
M-11: manufactured by Nippon Gohsei Kagaku Kogyo Co., Ltd.), and a resin-treated nonwoven fabric of 45 g / m ² was produced and evaluated.
The results are shown in Table 2.

[0030]

Examples 20 to 22 and Comparative Examples 13 to 14 Nonwoven fabrics having a fineness of 2.0 decitex and a basis weight of 45 g / m ² were produced in the same manner as in Example 11 by changing the spinneret shape and adjusting the flatness. Various physical properties were measured. The results are shown in Table 3. The reduced viscosity of the manufactured nonwoven fabric was 0.74 to 0.75. As is clear from Table 1, Table 2 and Table 3, the non-woven fabric of the present invention is superior in tensile strength and surface smoothness as compared with the comparative examples in comparison with the same basis weight, and the conventional non-woven fabric without resin processing. It is possible to achieve tensile strength and surface smoothness equivalent to or better than those of resin-processed nonwoven fabrics. Especially compared to each comparative example,
It is strong, thin, and has excellent peeling properties from the polyethylene sheath material, making it suitable for wire holding tape applications.

[0031]

[Table 1]

[0032]

[Table 2]

[0033]

[Table 3]

[0034]

Since the spunbonded nonwoven fabric of the present invention is excellent in surface smoothness and thin and strong, it is suitable for use in, for example, electric wire pressing winding tapes and printing substrates, and can be formed into a long length. It can be economically used due to its features such as goodness and no binder.

─────────────────────────────────────────────────── ─── Continuation of the front page (58) Fields surveyed (Int.Cl. ⁷ , DB name) D04H 1/00-18/00

Claims (2)

(57) [Claims] 1. A bonding fiber維間is performed only by heat and pressure
A no-binder type polyethylene terephthalate fiber scan <br/> Panbondo nonwoven, reduced viscosity of the polyethylene terephthalate textiles constituting the nonwoven fabric (ηsp / c) is 0.67 or more, fineness of 3.3 dtex or less , and the flatness of the cross section of the fiber is 1.5 or more, and the thickness of the nonwoven fabric satisfies the equation (1), the tensile further of the nonwoven fabric strength
Is 1,274 N / (3c per non-woven fabric thickness (1 mm)
A spunbonded non-woven fabric having a width of at least m . [Equation 1] Thickness (μ) ≦ 1.8 × Basis weight (g / m ² ) -5
(1) 2. A spunbonded nonwoven fabric according to claim 1 flatness of the cross section of polyethylene terephthalate textiles is 2.0 or more.