KR100220220B1 - The manufacture method of the modified polyamide-6 to fit high spinning - Google Patents

Abstract

The present invention relates to a method for preparing modified polyamide-6 by introducing organic diamine, organic dicarboxylic acid and phosphoric acid compound during polymerization of caprolactam in polymerizing caprolactam to produce polyamide-6. Polyamide-6 is prepared by high-speed spinning while maintaining the inherent properties and basic skeleton, and the yarn obtained by high-speed spinning is uniform and excellent physical properties.

Description

Method for preparing modified polyamide-6 suitable for high speed spinning

The present invention relates to a method for producing polyamide-6, and more particularly to a method for producing modified polyamide-6 having excellent stability against high-speed spinning.

Conventionally, one example for producing a polyamide that is stable to high-speed spinning is a method of adding an organic monoamine or an organic monocarboxylic acid as a viscosity stabilizer to a polyamide polycondensation step. However, this method has excellent viscosity stabilization effect in general spinning, but in high speed spinning, it does not reach a substantial equilibrium state as it is spun at high speed, which promotes decomposition of the polymer by reverse reaction, which causes the difference in physical properties, trimming, and smoke between radiators. There is an unsuitable problem in high-speed spinning, such as causing deterioration of nova.

Further, in the production of modified polyamides, Japanese Unexamined Patent Publications No. 38-11848, Nos. 44-25855, and Nos. 44-23342 disclose examples of methods using a phosphoric acid compound and a diamine salt as viscosity stabilizers. Although a method for producing a modified polymer made by addition to a polycondensation process is disclosed, Japanese Unexamined Patent Publication No. 48-23103 discloses a method for producing a modified polymer by adding the compound into a melt spinning machine, but the former method is a high-speed spinning In the process, there are many inadequate aspects such as pyrolysis and difference in physical properties between the spinner, trimming, etc., and the latter method has a disadvantage in that it is difficult to industrialize due to the unevenness of dispersion in the spinner.

Moreover, Japanese Unexamined Patent Application Publication No. 47-46601 discloses a method of using a copolymer composition of xylenediamine and adipic acid as an example of a method of using organic diamine and organic dicarboxylic acid as a viscosity stabilizer in the production of modified polyamide. US Pat. No. 59-21722 discloses a method for improving radioactivity by adding polyalkylene ester glycol to salts of polyhexamethylenediamine and adipic acid. US Pat. No. 4,022,756 discloses the use of hexamethylenediamine and dicarboxylic acid. Copolymerization, etc., but all of these methods relate to the modification of polyamide-6,6.

Therefore, an object of the present invention is to improve the polyamide-6 so as to be suitable for high-speed spinning while maintaining the intrinsic properties and basic skeleton of the polyamide-6.

Change of relative viscosity of polymer during spinning to obtain sufficient denaturing effect for high speed spinning Will require a polymer condition of less than about 0.1).

If a high viscosity polymer is used or the above conditions are not satisfied, the fiber does not substantially reach equilibrium during spinning residence time, resulting in radial trimming, deterioration in elongation, and salt spots between spinners. Difficult to do

Accordingly, the inventors of the present invention have investigated the addition of an appropriate amount of organic diamine and organic dicarboxylic acid to the polymerization process under a phosphoric acid catalyst in the polymerization process of polyamide-6. The value was easily suppressed to 0.04 or less and not only increased the reaction rate of the polymer, but also reached a substantial reaction equilibrium during the spinning process, and succeeded in obtaining uniform and good physical properties.

Therefore, according to the present invention, in the production of polyamide-6 by polymerizing caprolactam, organic diamine and organic dicarboxylic acid are used as the release stabilizer of the polymer, and the drop in polymerization viscosity due to the addition of the stabilizer is corrected by using a phosphate catalyst. And a method for producing a high-speed spinning modified polyamide-6, characterized in that it is retained.

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

In the present invention, the organic diamine and organic dicarboxylic acid used as the release stabilizer of the polymer are added at the time of polymerization of caprolactam together with the phosphoric acid compound.

Such modifiers are preferably added at the time of polymerization because they can achieve improved uniformity than other processes, for example during the drying of the polymer chip, or in the spinning machine.

At this time, the organic diamine and organic dicarboxylic acid is preferably to be polymerized under a phosphoric acid compound catalyst so that the total content is 0.5 to 10% by weight relative to the polyamide, more preferably 1 to 5% by weight, the organic diamine and organic dicarboxylic acid It is preferable to add silver in the same equivalence ratio.

The total content of organic diamine and organic dicarboxylic acid to be added is preferably less than 10% by weight compared to polyamide, but if it is added more than that, it is copolymerized and unsuitable for use in fibers, so it is improved while maintaining the basic properties of polyamide itself. In order to achieve this, it is preferable to use as little content as possible.

In the present invention, preferred examples of the organic diamine include trimethylenediamine, tetramethylenediamine, pentamethylenediamine, hexamethylenediamine, heptamethylenediamine, octamethylenediamine, nonamethylenediamine, tecamethylenediamine, xylenediamine, and the like. Preferred examples of dicarboxylic acid include adipic acid, glutaric acid, pipelinic acid, sebacic acid, terephthalic acid, isophthalic acid and the like. Moreover, said organic dicarboxylic acid and organic diamine can also be added in salt state. That is, it can also add in the diamine salt state of dicarboxylic acid. Preferred in this case are xylene diamine salts of adipic acid or terephthalic acid.

As a second additive, a phosphoric acid compound which is a catalyst is used, which is used for the purpose of improving the reactivity of organic diamine and organic dicarboxylic acid. Phosphoric acid compounds are added in catalytic amounts. Preferred examples of the phosphoric acid compound include phosphoric acid, hypophosphorous acid, sodium hypophosphite and the like.

According to the present invention, the modified polyamide-6 prepared by adding organic diamine and organic dicarboxylic acid together with a phosphate compound during caprolactam polymerization is used to change the viscosity of the polymer during spinning. It is possible to maintain a stable radial form satisfying ≤ 0.04, and the yarn obtained by spinning is uniform and excellent in physical properties.

Hereinafter, the present invention will be described in more detail by way of examples. However, the present invention is not limited to the following examples.

The amount of the above additive is preferably 1 to 5% by weight of the organic amine and the organic carboxylic acid compared to the polyamide. When the phosphoric acid compound is used as the second additive, It is possible to maintain a stable radiation state satisfying ≤ 0.04.

<Examples 1 to 9>

100 parts by weight of caprolactam, 2 parts by weight of water and organic diamine, organic dicarboxylic acid and phosphoric acid compound were added to the polymerization reactor in the kind and content as shown in Table 1 below and polymerized at 265 ° C. for 4 hours. After removing the internal pressure and reacted for 3 hours at a reduced pressure of 250torr to prepare a polyamide-6 chip. Each polyamide-6 prepared was to have the same relative viscosity of 2.64, the viscosity change between polymerization and spinning is shown in Table 1.

After extracting and drying the obtained polyamide-6 chip, it is spun under a condition of spinning temperature of 280 ° C. and discharge amount of 40 g / min through a spinneret made of SUS-316 material having 24 0.25 mmΦ holes in a 40mmΦ extruder. After cooling the air at 20 DEG C while blowing at an air velocity of 0.6 m / min to give an emulsion, it was wound at a speed of 4,600 m / min to obtain 70/34 (d / fil), which was cold drawn at a draw ratio of 1.55.

Physical properties of the obtained filaments are shown in Table 1. Among the properties shown in Table 1, the polymer warpage and breakout periods were spun using a nozzle sprayed with silicone oil, and the breakout times were measured and the average values are shown in Table 1, respectively.

<Comparative Examples 1 to 6>

100 parts of caprolactam, 2 parts of water and diamine and dicarboxylic acid were added to the polymerization reactor in the kind and content as shown in Table 1, respectively, and the polymerization was performed at 265 ° C. for 4 hours, after which the internal pressure was removed, and the pressure was reduced at 250torr for 3 hours. Reaction to give a polyamide with the same relative viscosity.

Thereafter, the same procedure as in Example 1 was repeated.

TABLE 1

In the present invention as described above, in the preparation of polyamide-6 by polymerizing caprolactam, the modified polyamide-6 prepared by adding organic diamine and organic dicarboxylic acid together with a phosphoric acid compound as a catalyst during polymerization of caprolactam is Viscosity change of polymer during spinning It is possible to maintain a stable radial form satisfying ≤ 0.04, to prevent decomposition and deformation of the polymer in the high-speed spinning process, to achieve a substantial reaction equilibrium during the spinning process to obtain a yarn with uniform and good physical properties.

Claims (5)

A method for producing modified polyamide-6 suitable for high-speed spinning, characterized in that polymerization of caprolactam to produce polyamide-6 is carried out by adding an organic diamine, an organic dicarboxylic acid and a phosphoric acid compound as a release polymer stabilizer. The modified polyamide according to claim 1, wherein the total of organic diamine and organic dicarboxylic acid is added in an amount of 0.5 to 10% by weight relative to polyamide-6, and the phosphoric acid compound is added at a ratio of catalytic titration to polymerize. 6 manufacturing method. The process for producing modified polyamide-6 suitable for high-speed spinning according to claim 1, wherein organic diamine, organic dicarboxylic acid and phosphoric acid compound are added to the caprolactam polymerization process. The method for producing modified polyamide-6 suitable for high-speed spinning according to claim 1, wherein the organic dicarboxylic acid and the organic diamine are added in a salt state or separately. 5. The process according to claim 4, wherein said salt is a xylenediamine or hexamethylenediamine salt of adipic acid or terephthalic acid.