KR0138171B1 - A process of preparing polyamide fiber - Google Patents

Abstract

The present invention is to provide a method for producing a polyamide fiber, characterized in that the addition of a magnesium compound and an amine compound as a release polymer stabilizer in the polymerization step in the production of polyamide fiber by the polymerization of ε-caprolactam. The polyamide fibers produced by the present invention have the advantage of excellent spinning and dyeing properties.

Description

Method for producing polyamide fiber

The present invention relates to a method for producing polyamide fibers, and more particularly, to preparing polyamide fibers by polymerization of ε-caprolactam, in which a magnesium compound and an amine compound are added together as a release polymer stabilizer in a polymerization step. The present invention relates to a method for producing a polyamide fiber having improved spinning and dyeing properties.

When the polyamide is melt-spun for a long time, volatile substances such as monomers and oligomers adhere to the spinning nozzle surface, and they are oxidized in hot air and accumulate as carbides. Carbide accumulated on the spinneret surface not only causes bending (bending) of the molten polyamide, which causes the polymer flow to bend during spinning, but also causes severe fracture of the molten polyamide by attaching it to the spinneret when the banding becomes more severe. . For this reason, if the radiation is stopped at a certain time and the spinning nozzle surface is not cleaned, it will greatly affect productivity. Therefore, in the case of melt spinning polyamide fibers, it is necessary to stabilize the state of the polymer discharged from the gear pump to the nozzle, and stabilization of the released state is absolute in order to mass-produce high quality polyamide, in particular.

In order to stabilize the release state, a release agent is generally applied to the discharge side of the spinneret. When the release agent is melt-initiated, the release state of the nozzle is applied to the discharge surface of the nozzle using a sprayer or the like, and the contamination around the nozzle discharge hole, the warpage of the released polymer, and the bending of the melted polymer are observed. After the spinning is suspended, the spinning machine is stopped, the release agent is applied (the above operation is called nozzle wiping, and the period from the start of the spinning to the nozzle modification is called the nozzle wiping cycle). do.

However, even when a release agent is used, the synthetic polymers are melt-spun, and contaminants are accumulated due to thermal decomposition of the synthetic polymers and gelation of the applied release agent, resulting in accumulation of contaminants and bending of the release polymers. Accumulation ultimately results in fine island abnormalities and single trimming.

In melt spinning of polyamide-based synthetic fibers, such as nylon 6, the nozzle wiping cycle is usually set to 1-3 days in consideration of the deterioration of the spinning state, and it is obvious that productivity is improved by extending the nozzle wiping cycle. One is true.

That is, by extending the nozzle wiping period, it is possible to prevent the occurrence of waste due to the deterioration and restart of the polymer staying in the spinning machine due to the interruption of the spinning (stop of the gear pump) and to greatly reduce the labor cost required for wiping. .

Various methods for extending the nozzle wiping period have been proposed. For example, Japanese Patent Application Nos. 45-6285 and 47-2056 disclose a method of extending the nozzle wiping period by adding a magnesium compound and a tin compound during spinning. However, when such a compound is added at the time of spinning, the residence time in the spinning machine is short, so that it is non-uniform and does not exert sufficient effects, and if the residence time is increased, the result is that the decomposition of synthetic polymers is promoted. In addition, when the organotin compound is used, not only the sand quality deteriorates but also a problem of coloring the polymer by thermally decomposing the polyamide during melting.

Therefore, the modification of the polymerization step is required rather than the addition of the magnesium compound at the time of spinning. However, in Japanese Patent Application No. 48-29492, the magnesium compound was added in the polymerization step, but in this case, the viscosity of the polymer was significantly lowered. . In addition, when the compounds are added in the polymerization step, it is possible to obtain the effect of extending the nozzle wiping cycle, but the effect is insignificant, resulting in a problem that the dyeing property of the polyamide fiber is reduced.

Accordingly, it is an object of the present invention to overcome the above-mentioned problems in the prior art, and to provide a method for producing a polyamide fiber, in which the nozzle wiping period is significantly extended and the spinning and dyeing properties are greatly improved without lowering the polymerization viscosity.

That is, according to the present invention, in producing a polyamide fiber by polymerization of ε-caprolactam, a polyimide with improved radioactive dyeing resistance, characterized by adding a magnesium compound and an amine compound together as a release polymer stabilizer in the polymerization step. It is to provide a method for producing an amide fiber.

In the present invention, when the magnesium compound is added alone, the effect of extending the nozzle wiping period is obtained, but the polymerization viscosity decreases and the dyeing property becomes poor, so that a monoamine or diamine-based compound is added together to prevent this. It is essential.

In the present invention, the addition amount of the magnesium compound should be 10 to 50 ppm relative to the polyamide. In the present invention, when the amount of the magnesium compound added is less than 10 ppm, the effect of extending the nozzle wiping period is insufficient, and when the amount of the added amount exceeds 50 ppm, the effect of extending the nozzle wiping period becomes good, but it is not preferable because it causes a decrease in yarn properties.

The magnesium compound that can be used in the present invention is preferably one selected from the group consisting of magnesium acetate, magnesium chloride, and magnesium oxide.

In the present invention, the amine compound is preferably added in an amount of 0.1 to 1.0% by weight, preferably 0.2 to 0.4% by weight based on the polyamide. If the addition amount of the amine compound is less than 0.1% by weight, the phenomenon of lowering the polymerization viscosity is not improved. If the addition amount is more than 1.0% by weight, the effect of extending the nozzle wiping period is reduced. Therefore, in the present invention, it is essential that the addition amount of the magnesium compound and the amine compound is kept within the above range.

The amine compound usable in the present invention is preferably one selected from hexamethylenediamine, benzylamine, butylamine and isopropyl diamine.

The method of the present invention improves the overall productivity by extending the nozzle wiping cycle by adding magnesium compound and preventing single cutting, and improving the yarn quality by preventing polymerization viscosity decrease and improving dyeing by adding amine compound. Has the advantage.

Hereinafter, the present invention will be described in detail with reference to Examples, but the present invention is not limited by the following Examples.

Examples 1-6

100 parts of caprolactam, 2 parts of water, and the addition amount of magnesium compound and amine compound shown in Table 1 were added to the polymerization reactor and polymerized at 265 ° C. for 4 hours, and then the internal pressure was removed and reacted for 3 hours under reduced pressure of 250 torr. Polyamides having relative viscosities were prepared, and the relative viscosities are shown in Table 1 below. The obtained polyamide chip was extracted, dried and spun through a spinning nozzle using a 40 mm φ extruder at a spinning temperature of 280 ° C. and a discharge amount of 40 g / min. Spinning was carried out using a cage of SUS 316. Next, the cooling air at 20 ° C. was cooled and solidified while blowing at a wind speed of 0.6 m / min, and an emulsion was added thereto. Subsequently, it was wound up at a speed of 900 m / min to obtain 70 ^d / 34 ^f of undrawn yarn, which was then cold drawn at a draw ratio of 1.55 to prepare a polyamide filament.

The physical properties of the obtained polyamide filament was evaluated and shown in Table 1 below. Determination of the warpage and short cut incidence period of the released polymer was spun using a nozzle sprayed with silicon oil, and the warpage and short break initiation time of the first polymer were measured and averaged, respectively.

Comparative Example 1

A polyamide filament was prepared in the same manner as in Example 1 except that the magnesium compound and the amine compound were not added in the polymerization step, and the results thereof were evaluated and shown in Table 1 below.

Comparative Examples 2 to 3

The polyamide filament was prepared in the same manner as in Example 1 except that the addition amount of the magnesium compound and the amine compound in the polymerization step was changed outside the scope of the present invention as shown in Table 1 below, and the results thereof were evaluated. Together.

Comparative Examples 4-6

Only 100 parts of caprolactam, 2 parts of water, and magnesium compound were placed in a polymerization reactor, and the mixture was polymerized at 265 ° C. for 4 hours to remove internal pressure and reacted for 3 hours under reduced pressure of 250 torr to prepare a polyamide having a constant relative viscosity. At this time, the relative viscosity is shown in Table 2 below. Thereafter, spinning and stretching were conducted in the same manner as in Example 1, and the bending, breakage occurrence time, and physical properties of the obtained filaments were evaluated. The results are shown together in Table 2 below.

Comparative Examples 7-9

Only 100 parts of caprolactam, 2 parts of water, and an amine compound were placed in a polymerization reactor, and polymerized at 265 ° C. for 4 hours to remove internal pressure and reacted for 3 hours under reduced pressure of 250 torr to prepare a polyamide having a constant relative viscosity. At this time, the relative viscosity of each is shown in Table 2 below. Thereafter, spinning and stretching were conducted in the same manner as in Example 1, and the bending, breakage occurrence time, and physical properties of the obtained filaments were evaluated. The results are shown together in Table 2 below.

Mg ^a) Added amount (ppm) HMDA ^b) Added amount (% by weight) Polymerization Viscosity (RV) Breaking time (hrs) Yarn Strength (g / d) Yarn Elongation (%) Dyeing Comparative Example 1 - - 2.65 27 7.26 52.4 standard Example 1 10 0.1 2.65 56 7.28 52.2 Great Example 2 25 0.2 2.65 61 7.30 51.9 Great Example 3 50 0.3 2.64 58 7.28 55.6 Great Example 4 25 0.1 2.60 52 7.31 56.2 Great Example 5 25 0.3 2.48 48 7.25 52.6 Great Example 6 50 0.5 2.39 55 6.27 52.9 Great Comparative Example 2 5 0.05 2.68 30 7.25 52.6 usually Comparative Example 3 75 1.0 2.66 65 7.12 53.1 usually

a) magnesium acetate b) hexamethylenediamine

Mg ^a) Added amount (ppm) HMDA ^b) Added amount (% by weight) Polymerization Viscosity (RV) Breaking time (hrs) Yarn Strength (g / d) Yarn Elongation (%) Dyeing Comparative Example 4 10 - 2.64 52 7.26 52.4 usually Comparative Example 5 25 - 2.60 62 7.31 56.2 usually Comparative Example 6 50 - 2.56 61 7.25 52.6 Bad Comparative Example 7 - 0.1 2.39 48 6.27 50.9 Great Comparative Example 8 - 0.2 2.68 40 6.05 48.6 Great Comparative Example 9 - 0.5 2.66 29 5.58 45.1 Great

Claims (4)

A method for producing a polyamide fiber, comprising producing a polyamide fiber by polymerization of? -caprolactam, adding a magnesium compound and an amine compound together as a release polymer stabilizer in a polymerization step. The method of claim 1, The magnesium compound is added in an amount of 10 to 50 ppm relative to the epsilon caprolactam, and the amount of the amine compound added is 0.1 to 1.0 wt% based on the epsilon caprolactam. The method of claim 1, And said magnesium compound is one kind selected from the group consisting of magnesium acetate, magnesium chloride and magnesium oxide. The method of claim 1, The method of producing a polyamide fiber, characterized in that the amine compound is one selected from hexamethylenediamine, benzylamine, butylamine, isopropyl diamine.