KR20010086572A - Preparation of high strength polyester multifilament yarn having good dimensional stability and dyeability - Google Patents

Abstract

PURPOSE: A process for preparing high strength polyester yarn exhibiting high strength and low shrinkage characteristics and having excellent heat resistance and dyeability is provided. Whereby, the polyester yarn is useful as industrial fabrics containing heat-treating processes, if necessary a dyeing process in post processes. CONSTITUTION: In a multifilament yarn manufactured by melt spinning a polyester polymer containing polyethylene terephthalate as a main repeating unit and having an intrinsic viscosity of 0.7 or more, the multifilament yarn has a crystal structure of a birefringence rate of 0.02 or more, crystallization degree of 45 or more, crystal size in the parallel direction of a fiber shaft of 0.77 angstrom or less, crystal size in the right-angle direction of a fiber shaft of 45 angstrom or more, volume fraction in the amorphous area of 0.54 or less, crystal orientation of 0.93 or more and amorphous orientation of 0.70 or more.

Description

Preparation of high strength polyester multifilament yarn having good dimensional stability and dyeability

The present invention relates to a method for producing a high strength polyester yarn having excellent shape stability and, in particular, excellent dyeing property. More particularly, the present invention relates to excessive heat in processing processes including seat belts, webbing materials, and the like. The present invention relates to a method for producing a high strength polyester yarn having excellent morphological stability and excellent dyeing property, which can solve the tendency of lightening due to deepening and deepening and a high orientation.

Conventionally, yarns used for seat belts, web ice products, etc. are mainly manufactured by a direct spinning drawing method, and yarns that express high-strength characteristics by drawing low-stretched undrawn yarns at high magnification have been used.

However, these yarns have a high draw ratio (D / R) and a low draw ratio (R / R), making it difficult to express low shrinkage characteristics, which causes a strong thermal degradation. In addition, since the crystal orientation and non-orientation are large, the size of the molecular crystal is small, and there are many tie chains, it is difficult to adsorb dye molecules during dyeing, so that the color of the dye is pale, and the dyeing color becomes thin. There is a drawback that the frictional fastness is very low.

In addition, when weaving seat belts and webbings by applying yarns manufactured using such a conventional manufacturing method, manufacturing costs are high because a lot of inclined water enters in consideration of the strong deterioration. Because of the poor dyeability, the amount of dye used, the dyeing treatment temperature and the treatment time should be increased, there is a problem that the manufacturing cost in the post-processing is high.

Accordingly, an object of the present invention is to provide a high-strength polyester yarn which minimizes the strong drop due to heat and is excellent in dyeing in view of the above-mentioned problems of the prior art.

According to the present invention achieving the above object, in a multifilament yarn produced by melt spinning a polyester polymer having polyethylene terephthalate as a main repeating unit and having an intrinsic viscosity of 0.7 or more, the birefringence of 0.20 or more and the crystallinity of 45 or more , Crystal size in the parallel direction of the fiber axis (A ₁₀₅ ) 0.77Å or less, crystal size in the direction perpendicular to the fiber axis (A ₀₁₀ ) 45Å or more, volume fraction (Va) of the amorphous region 0.55 or less, crystal orientation (fc) Provided is a polyester multifilament yarn for industrial fabric having excellent dyeability, having an internal structure of at least 0.93 and at least 0.70 in non-orientation.

In addition, according to the present invention, as one of the preferred methods for producing the polyester multifilament yarn having the above characteristics, a polyethylene polymer having a polyethylene terephthalate as the main repeating unit and an intrinsic viscosity of 0.7 or more, elongation rate of 500-800m / mim, elongation Provided is a method for producing polyester multifilament yarn for industrial fabrics having excellent dyeability, including direct spinning and stretching under process conditions of 5.5 to 6.0 times magnification, relaxation rate of 4 or less, and relaxation and heat treatment temperatures of 220 to 250 ° C.

Hereinafter, the present invention will be described in more detail.

The polyester multifilament yarn according to the present invention has a birefringence (Δn) of 0.20, preferably 0.2050 or more, crystallinity (Xc) of 45 or more, crystal size in the fiber axis parallel direction (A ₁₀₅ ) 77 mm or less, crystal size in the fiber axis perpendicular direction ( A ₀₁₀ ) has an internal structure satisfying 45 Å or more, crystal orientation (fc) 0.93 or more, amorphous region orientation (non-orientation) 0.70 or more, amorphous region volume fraction 0.54 or less, preferably 0.54080 or less. Polyester multifilament yarns have high strength and low shrinkage characteristics, and have excellent heat-resistant strength and dyeing properties, so that the heat treatment process is included in the post process such as seat belts and web ice materials, and the dyeing process is included as necessary. Particularly suitable for

In addition, the polyester multifilament yarn of the present invention is characterized by having a characteristic of the maximum shrinkage stress 0.40 cN / dtex or less at 220 ℃.

Hereinafter, an example of a preferred method for producing a polyester multifilament yarn according to the present invention will be described. Of course, it should be understood that the method for producing the polyester multifilament yarn of the present invention is not limited to the method described below.

In the present manufacturing method, the crystal size and crystallinity are adjusted by adjusting the heat set temperature in the process to change the crystal structure inside the molecule in order to have excellent dyeability compared to the conventional high strength yarn. At the same time, the relaxation process is adjusted to express the characteristics of low shrinkage so that the characteristics of low shrinkage and excellent dyeability are expressed. In addition, by expressing the characteristics of low shrinkage, it is possible to minimize the change of the internal structure of the molecule due to heat, thereby improving the heat resistance strength.

According to this method, a melt polymer obtained by melting and discharging a polyester solid-state polymer chip having an intrinsic viscosity of 0.7 or more with polyethylene terephthalate as the main repeating unit is set at a spinning speed of 500 to 800 m / min, a draw ratio of 5.5 to 6.0 times, and a relaxation rate. Is 4 or less, and a yarn having a monofilament fineness of 12.5 denier or less is produced with a heat treatment and relaxation temperature of 220 to 250 ° C. At this time, 285-295 degreeC of spinning temperature is preferable, and 500-2,000 denier of total fineness is preferable.

When the spinning speed is low, it is difficult to wind due to low radiation tension, and it is difficult to apply productivity due to low productivity. If the spinning speed is high, the operability due to the occurrence of heavy rain is greatly reduced, and the quality of the yarn is dropped, making it difficult to apply.

In addition, when the draw ratio is less than 5.5 times, it is difficult to express the required high-strength characteristics, and when it exceeds 6 times, the quality of the yarn is lowered due to the occurrence of the moor. When the relaxation rate is less than 4, the shrinkage stress is lowered, but it is difficult to express the characteristics of high strength, and the heat resistance strength is somewhat lowered.

The temperature at the time of relaxation and heat treatment is also important. If this temperature is less than 220 ℃, it is difficult to express the characteristics of low shrinkage, and the damage of heat-resistance strength is severe, and if it is above 250 ℃, tar is generated on the cutting and hardening roller. This frequent operation is inferior.

In the case of the yarn manufactured within the above condition range, the yarn has the internal structure as described above, expresses the characteristics of high strength and low shrinkage, has a strong drop by heat and is excellent in heat resistance and excellent in dyeing.

Here, the heat resistant strength indicates the strength ratio after the heat treatment step during the post-process to the strength in the yarn state, and when the heat resistant strength is 100, there is no strong damage due to heat.

In order to improve such heat resistance, low shrinkage is required to minimize the molecular structure change with respect to heat. In general, in the case of a high strength polyester yarn, it goes through a post-process, a strong deterioration occurs particularly in the case of going through a process such as dyeing. In addition, in the internal structure of the molecule, the crystal size is small, the number of tie chains is high, and the orientation of the crystal and the amorphous region is high, so that the dye is not easily adsorbed, so that the dyeability is poor, and the color tends to be pale.

In the present invention, in order to improve the heat resistance reduction and lightening tendency of the conventional high-strength polyester yarns by adjusting the crystal size and orientation in the molecule to an appropriate level to give a high-strength polyester yarn excellent in heat resistance and dyeing resistance It can be manufactured.

Features and other advantages of the present invention as described above will become more apparent from the following examples. However, it should be understood that the present invention is not limited to the following examples.

The physical properties and dyeing properties of the yarns presented in the above description of the present invention and the following examples are measured by the following method.

※ Properties of Yarn

* Strong, cutting elongation (cutting): measured by a universal measuring instrument (Instron).

* Dry heat shrinkage (number): Shows the rate of change in length before and after shrinking of the yarn heat-shrunk under the condition of 150 ℃ × 30 minutes under no tension.

Shrinkage () = (L ₀ -L ₁ ) / L ₀ × 100

(L ₀ : length before heat shrink, L ₁ : length after heat shrink)

* Heat resistance strength measurement: It shows the rate of change before and after heat treatment of yarn heat treated at 220 ℃ × 10 minutes under no tension.

Heat Resistance Strength () = (S ₀ -S ₁ ) / S ₀ × 100

(S ₀ : yarn strength before heat shrink, S ₁ : yarn strength after heat shrink)

* Shrinkage stress (unit: cN / dtex): Measures the maximum shrinkage stress at 220 ℃ using a test light (TESTRITE).

※ Dyeability measurement

-Dyeing: Using Mathis mangle [Dye: Microsolorange GR 0.3wt solution (Ciba-Geigy)],

Thermoset: using a Mathis steamer,

Color measurement: CCM (Computer Color Matching)

-Dyeability Evaluation: Comparison of K / S values of dyeing materials.

<Examples 1 to 6 and Comparative Example 1>

The yarn was manufactured under the conditions of Table 1 by spinning a polyester having an intrinsic viscosity of 0.7 or more at a temperature of 290 ° C. using a direct spinning drawing method. The internal structure of the manufactured yarn was measured according to the conventional method, and the physical properties thereof were measured by the above-described method. The measurement results are shown in Tables 2 and 3 below.

The yarn was woven into a fabric having a weft density of 26 yarns / inch × 26 yarns / inch, thermoset at 220 ° C. for 5 minutes, and thermosol dyeing with a mangle pressure of 2 kg / cm 2. (Thermosol dyeing) was performed to compare the dyeability. The staining results are shown in Table 3 below.

division Spinning speed (m / min) Stretch ratio (times) Relaxation rate () Heat treatment / relaxation temperature (℃) Example 1 500 5.9 1.5 235/230 Example 2 750 5.6 2.0 245/240 Example 3 600 5.75 2.2 240/235 Example 4 800 5.5 3.5 230/220 Example 5 580 5.8 1.0 235/230 Example 6 630 5.7 1.5 240/230 Comparative Example 1 550 5.75 1.8 200/160

division Internal structure of yarn Molecular orientation Crystallinity Crystal structure Birefringence Crystal orientation (fc) Non-orientation (fa) A ₁₀₅ A ₀₁₀ Va Example 1 0.2125 0.9565 0.7817 47.23 76 47 0.5437 Example 2 0.2092 0.9456 0.7517 49.05 75 60 0.5191 Example 3 0.2107 0.9486 0.8017 48.09 76 53 0.5271 Example 4 0.2050 0.9327 0.7263 45.32 75 56 0.5235 Example 5 0.2110 0.9461 0.8387 47.15 72 43 0.5480 Example 6 0.2105 0.9517 0.7965 47.85 74 49 0.5307 Comparative Example 1 0.2097 0.9532 0.8480 44.62 76 42 0.5686

division Yarn Properties and Dyeing Properties Denier Strength (g / d) Body () Number of cases () Heat resistant strength Maximum Shrinkage Stress (cN / dtex) K / S value (at 620 nm) Example 1 2,000 9.42 12.8 8.8 85.6 0.38 9.72 Example 2 1,000 9.26 14.9 6.7 89.2 0.28 10.01 Example 3 1,500 9.21 15.2 7.4 88.3 0.35 10.14 Example 4 1,500 9.14 16.7 7.2 83.0 0.24 8.09 Example 5 1,500 9.34 13.7 9.5 87.5 0.37 9.45 Example 6 500 9.25 15.0 8.4 88.7 0.31 9.1 Comparative Example 1 1,500 9.12 14.5 10.4 82.5 0.45 7.23

As can be seen from the experimental results of the above-described examples and comparative examples, polyester multifilament yarn having an internal structure according to the present invention exhibits high strength, low shrinkage characteristics, and has a strong heat resistance and is excellent in heat resistance. Excellent dyeing property, heat treatment process in post process such as seat belt, web ice, etc., and it is very useful for industrial fabric including dyeing process if necessary.

Claims (3)

In multifilament yarns produced by melt spinning a polyester polymer having polyethylene terephthalate as the main repeating unit and having an intrinsic viscosity of 0.7 or more, the birefringence of 0.20 or more, the crystallinity of 45 or more, and the crystal size in the fiber axis parallel direction (A ₁₀₅ ) It has an internal crystal structure of 0.77Å or less, crystal size in the perpendicular direction of the fiber axis (A ₀₁₀ ) 45Å or more, volume fraction of amorphous region 0.55 or less, crystal orientation (fc) 0.93 or more, non-orientation 0.70 or more Polyester multifilament yarn for industrial fabrics with excellent dyeability. The dyeing property according to claim 1, wherein strength of 9.0 g / d or more, elongation at break of 12 to 17, dry heat shrinkage of 6 to 9, heat resistance of at least 85, and maximum shrinkage stress of 0.4 cN / dtex are simultaneously satisfied at 220 ° C. Excellent polyester multifilament yarn for industrial fabrics. In producing polyester multifilament yarn by direct spinning, the polyester polymer with polyethylene terephthalate as the main repeating unit and the intrinsic viscosity of 0.7 or more has a spinning speed of 500 to 800 m / mim, stretching ratio of 5.5 to 6.0 times, and relaxation rate. 4 or less, a method for producing polyester multifilament yarn for industrial fabrics having excellent dyeability, including direct spinning and stretching under process conditions of relaxation and heat treatment temperatures of 220 to 250 ° C.