JPH07278951A - Nylon 66 material for spinning and production of nylon 66 yarn - Google Patents

Abstract

PURPOSE:To obtain a nylon 66 material capable of suppressing end breakage of spinning to a low even in high-speed spinning and providing yarn having high strength and high elongation. CONSTITUTION:This nylon 66 material is a mixture of pellets of a polymer substantially composed of nylon 66 and polymer powder of nylon 66 in which the crystallization temperature in temperature drop of the polymer powder is 10-25 deg.C higher than the crystallization temperature in temperature drop in temperature drop of the pellets and correlation of the formula B<=-10A+600 is shown when the difference between the crystallization temperature in temperature drop of the polymer powder and the crystallization temperature in temperature drop of the pellets is A deg.C and the content of the polymer powder is Bppm. The nylon 66 material is effective for suppressing formation of spherulite in yarn.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a nylon 66 material for high-speed yarn production, which is excellent in yarn quality and yarn operability by suppressing yarn crystallization and spherulite formation during high-speed yarn production.

[0002]

2. Description of the Related Art Nylon 66 fiber is excellent in strength, durability, heat resistance, stretchability and dyeing fastness, so it is used for clothing such as stockings and sportswear, and for industrial applications such as tire cords and carpets. It is used for purposes. In order to improve the industrial productivity of this nylon 66 fiber and improve the level dyeing property, it has been practiced to spin the yarn at a high speed of 3000 m / min or more.

[0003]

However, as described above, when the spinning speed is increased, the number of yarn breakages that occur during spinning rapidly increases, and the yarn operability is greatly reduced, and the yarn strength and elongation are increased. Will decrease, and problems such as the inability to obtain good quality yarn will occur. Therefore, there has been a strong demand for a nylon 66 yarn-making material which causes less breakage of spun yarn even at high-speed yarn production and does not reduce the strength or elongation of the yarn. As a solution to this,
JP-A-53-43745 proposes a method for reducing the amount of powder in a polyamide material. However, this method cannot completely prevent spun yarn breakage.

The main object of the present invention is to produce a yarn at a speed of 3000 m.
An object of the present invention is to provide a nylon 66 material for high-speed yarn spinning, which can suppress spun yarn breakage even when spinning at a high speed of not less than 1 minute / minute, has excellent yarn operability, and does not reduce the strength or elongation of the yarn. In particular, the present invention is to provide a nylon 66 material for high speed spinning which is effective in suppressing spherulitic crystal formation during spinning and suppressing thermal denaturation.

[0005]

That is, the present invention provides a "mixture of polymer pellets consisting essentially of nylon 66 and polymer powder, wherein the temperature of falling crystallization of the polymer powder is lower than the temperature of falling crystallization of the pellet. 10 to 25 ° C. higher, where the difference between the cooling crystallization temperature of the polymer powder and the cooling crystallization temperature of the pellets is A ° C., and the content of the polymer powder is Bppm, the relationship of formula (I) A nylon 66 material for yarn making, characterized by having.

B ≦ −10 A + 600 (I) ”.

The details of the present invention will be described below.

Nylon 66 as used herein is a polycondensate of adipic acid and hexamethylenediamine. Of course, additives that are usually added to nylon 66, such as viscosity stabilizers such as acetic acid, matting agents such as titanium oxide, light stabilizers such as manganese compounds, heat-resistant agents such as copper compounds, other antistatic agents, dispersants, terminal groups. A quantity adjusting agent or the like may be added. The polymerization method of nylon 66 may be a continuous type or a batch type. For nylon 66 having a high degree of polymerization such as for tire cords, the degree of polymerization may be increased by reducing the pressure in the liquid phase.
Further, the liquid-phase polymerized nylon 66 pellets may be solid-phase polymerized at a temperature below the melting point under vacuum or under a nitrogen stream. Nylon 66 in a molten state after completion of the liquid phase polymerization is extruded from the lower part of the polymerization reaction tank in a strand shape or a sheet shape, cooled with a refrigerant such as water, and then cut with a pelletizer,
Pellet.

Thereafter, if necessary, the pellets are dried or solid-phase polymerized, and then subjected to spinning. The pellet in the present invention is a granular nylon 66 that is cut by a pelletizer and supplied to a spinning machine in this way, and its shape is a circle when extruded from a polymerization can or a cutting method of a pelletizer. The shape is columnar, cubic, rectangular parallelepiped, or amorphous, but is not particularly limited.

Nylon 66 material contains substantially powder. The cause of the generation is, for example, the cutting by the pelletizer described above and the chip surface scraped when the pellet is blown by friction with the pipe or the like.

Generally, a difference occurs between the crystallization temperature of the pellet and the powder. It is thought that this is because the powder is more likely to crystallize due to shearing due to cutting, and the surface is deteriorated by a slight amount of oxygen during the process of receiving heat such as drying under nitrogen stream or under reduced pressure and solid phase polymerization. .

In order to prevent spinning breakage, which is an object of the present invention, the crystallization temperature of the powder is 10 times higher than that of the pellet.
It is necessary to be higher by 25 ° C to 25 ° C. When the temperature is lower than 10 ° C, it is necessary to reduce the shearing rate of the blade into the polymer during cutting in order to reduce the crystallization temperature, and it becomes difficult to secure a desired amount of chips and a desired size of chips. Because it will be. If the temperature exceeds 25 ° C, yarn breakage during spinning tends to occur. Further, when the content of the powder is large, yarn breakage during spinning is likely to occur, which is not preferable. Therefore, the difference between the temperature falling crystallization temperature of the polymer powder and the temperature falling crystallization temperature of the pellets is set to A ° C., When the content of the polymer powder is Bppm, it is necessary that the nylon 66 material for yarn making is characterized by having the relationship of the formula (I).

B ≦ −10 A + 600 (I) More preferably, the amount of powder in the nylon 66 material is 30.
It is preferably 0 ppm or less.

As a concrete method for controlling the powder content, it is necessary to maintain the pelletizer (polishing the blade and shortening the clearance between the fixed blade and the rotary blade), but the temperature is as high as possible. Cutting in the state is preferable. In order to reduce the amount of powder produced during air blowing, it is preferable to reduce the air blowing speed, and high-concentration transportation (high concentration, low-speed transportation) is preferable.

It is also useful to separate the resulting powder from nylon 66 pellets. For example, a method of separating with a vibrating screen or wind, washing with water, etc. are exemplified. This powder separator may be installed between the above-mentioned cutting process and the spinning machine. The number of separators may be one or a combination of a plurality of separators, but it is effective to install them in a process as close as possible to the spinning machine.

The nylon 66 material for yarn making of the present invention is
Nylon 6 producing caprolactam and / or ε-aminocaproic acid to suppress yarn orientation in high speed spinning
It is particularly effective for nylon 66 obtained by adding 0.1 to 5% by weight to 6 and polymerizing.

The nylon 66 material for yarn making described above is
Nylon 66 fibers are produced by spinning.
Particularly, for the purpose of the present invention, the spinning speed is 3000 m.
It is preferable that the speed is not less than / minute.

[0018]

EXAMPLES The present invention will now be described in more detail with reference to examples.

The cooling crystallization temperature (hereinafter abbreviated as Tc) and the mixed powder amount are measured by the following method.

Temperature falling crystallization temperature (Tc) Using a differential scanning calorimeter, 3 mg of a sample was taken and heated at 80 ° C./min.
After keeping the molten state at 285 ° C. for 6 minutes, the temperature is lowered at 80 ° C./min. The peak temperature of heat generated by crystallization is defined as Tc (average value of three measurements).

Amount of mixed powder: A 5L stainless beaker was charged with a basket made of a cylindrical metal mesh with a bottom and an opening of 1 mm. About 500g of sample and about 3L of water
Put in a basket and stir for about 10 minutes. After that, the basket containing the chips is pulled up from the beaker. The water in the beaker is filtered with a filter having an opening of 10 μm, and the ratio of the amount of powder on the filter to the sample weight is obtained (average value of three measurements).

Examples 1 to 5 and Comparative Examples 1 to 4 Hexamethylene diammonium adipate salt was added by a conventional method after adding 0.30% by weight of titanium oxide and 1% by weight of caprolactam to the polymer. The molten nylon 66 is extruded in a strand form from the polymerization can, cooled,
Cutting was performed to obtain pellets having a diameter of 3 mm and a length of 3 mm. The Tc of the obtained pellets was 189 ° C.

The pellets thus obtained were dried at 120 ° C. for 15 hours at 120 ° C. under a reduced pressure of 5 mmHg or less at a rotation speed of 8 rpm, and then polymer powder was obtained using a powder separator shown in FIG. After separating the
70 denier 24 filament nylon 6 at speed of minute
Six yarns were produced. Table 1 shows the results of yarn production with different powder separation degrees.

The powder having a high Tc has a low ηr (measured at a 98% sulfuric acid concentration of 1%) and is thermally denatured. In addition, the formula (I)
In Examples 1 to 5 in which the amount of powder satisfying the above relationship, the number of yarn breakages during spinning was small. Further, in Comparative Examples 1 to 4 in which the amount of powder does not satisfy the relationship of the formula (I) and Comparative Example 4 in which the temperature of falling crystallization of the powder is high, the number of spherulites in the yarn is large, and thus the yarn breaks at the time of spinning, The strength was also low.

[0025]

[Table 1]

Examples 6 to 8, Comparative Examples 5 to 6 Hexamethylene diammonium adipate salt with copper iodide as copper of 70 ppm and potassium iodide as potassium 3
After adding 00 ppm and polymerizing by a conventional method, melted nylon 66 is extruded in a strand form from a polymerization can, cooled,
Cutting was performed to obtain pellets having a diameter of 3 mm and a length of 3 mm. The obtained nylon 66 material was subjected to solid phase polymerization at 160 ° C. for 12 hours by a tower dryer or a double-cone type rotary dryer to obtain pellets having ηr of 3.6. After separating the polymer powder with a powder separator in the same manner as in Example 1 for each of them, 190 with a spinning machine at a speed of 3000 m / min.
A thread for tire cord having 0 denier 300 filament was produced. The spinning results are shown in Table 2. From Examples 6 to 8 and Comparative Examples 5 to 6, it can be seen that when a nylon 66 material containing a large amount of powder is spun, the strength and the elongation are lowered, and the full pipe ratio (meaning the yield) is also lowered.

[0027]

[Table 2]

[0028]

EFFECTS OF THE INVENTION When the nylon 66 material of the present invention is used, even if the yarn is spun at a high speed of 3000 m / min or more, the spun yarn breakage can be suppressed to a low level, the spinning processability is improved, and high strength and high elongation are achieved. You can get a thread of degree. The method of the present invention is effective for suppressing the formation of spherulites in yarn.

[Brief description of drawings]

FIG. 1 shows an outline of a powder separator used in Examples.

[Explanation of symbols]

 1: Double cone type rotary dryer 2: Pellet blower equipment 3: Pellet powder separator 4: Pellet receiving container 5: Powder collector

Claims (4)

[Claims] 1. A mixture of polymer pellets consisting essentially of nylon 66 and polymer powder, wherein the falling crystallization temperature of the polymer powder is 10 times lower than the falling crystallization temperature of the pellets.
-25 ° C. higher, the difference between the cooling crystallization temperature of the polymer powder and the cooling crystallization temperature of the pellets is A ° C., and the content of the polymer powder is Bppm, the formula (I)
A nylon 66 material for yarn making, which has the following relationship. B ≦ −10A + 600 (I) 2. Nylon 66 contains ε-caprolactam and / or ε-aminocaproic acid in an amount of 0.1 relative to the produced nylon 66 polymer during the polymerization of nylon 66.
The nylon 66 material for yarn making according to claim 1, wherein the nylon 66 material is added in an amount of -5% by weight. 3. Nylon 6 for yarn making according to claim 1 or 2.
A method for producing nylon 66 fiber, characterized in that 6 materials are spun into yarn. 4. The method for producing nylon 66 fiber according to claim 3, wherein the spinning speed is 3000 m / min or more.