KR920006377B1 - Manufacturing process of nylon-46 fiber - Google Patents

Abstract

A nylon-46 fiber is produced by melt spinning the mixture consisting of polytetramethylene adipamide resin (linear soluble nylon-46), bisoxazoline compound of formula (I) and bisoxazione compound of formula (II) [where X is a compound containing bivalent organic group in the presence of manganese phosphate or alkali metal halogen compound. The bisoxazoline compound is pref. 1,3-phenylene-bis-2-oxazoline or 1,4-phenylene-bis-2-oxazoline and bisoxazione compound is 2,2-bis(4H-3,1-benzoxazine-4-one). The nylon-46 fiber has a thermal stability and high strength.

Description

Method of Making Nylon-46 Fiber

The present invention reacts with a bisoxazolin-based compound that reacts with a carboxyl group, which is a terminal group of nylon-46, to a nylon-46 resin to give thermostability to polytetramethyleneadipamide (hereinafter referred to as nylon-46), and a terminal amino group. The present invention relates to a method for producing a nylon-46 fiber, which is characterized by melt spinning in the presence of a manganese phosphate and an alkali metal halide after the addition of a bisoxazione-based compound.

Methods for preparing nylon-46 resins are described in detail in US Pat. Nos. 4,408,036 and 4,446,304, Japanese Patent Laid-Open No. 58-83029,56-149431, and the like.

Nylon-46 has high melting point and high glass transition temperature, so it has better heat resistance, especially dimensional stability at high temperature than nylon 6 or 66, and it is easier to pack molecular chains than nylon 6 or 66 and per unit carbon number. Since there are many hydrogen bonds, the crystallization rate is fast and the crystallinity is very high.

Nylon-46 also has excellent chemical resistance and other mechanical properties.

On the other hand, nylon-46 has high heat deflection temperature and melting point, but similar melting point and pyrolysis temperature, so that pyrolysis occurs severely when manufacturing industrial materials such as tire cords. It was difficult to produce fibers having physical properties suitable for tire cords.

In addition, nylon-46 has not yet been industrialized due to its poor melt processability despite its excellent thermal and mechanical properties.

Therefore, improving thermal stability in the molten state is a challenge for nylon-46, but no specific method has yet been proposed. However, according to Japanese Patent Laid-Open No. 62-185745, a method of using a hindered phenol type as an antioxidant is known. However, antioxidants alone do not sufficiently prevent the reduction of relative viscosity or other deterioration of physical properties during melt processing.

In particular, it is more difficult to prevent pyrolysis in the case of long spinning than in the case of injection molding. In general, it is known to add various thermal stabilizers such as phenolic compounds, phosphorus compounds, aromatic amines, and copper halides in order to prevent physical degradation and discoloration due to thermal decomposition of polyamides.

However, since nylon-46 has a much higher thermal decomposition rate than nylon 6 or 66, these thermal stabilizers alone cannot prevent thermal decomposition.

According to Japanese Patent Application Laid-Open No. 50-59525,56-91009, a method of using a chain extender as a method of obtaining a high molecular weight polymer in a short time has been introduced. In particular, a terminal carboxyl group is added by adding a bisoxazoline compound as a chain extender of polyester. It is reported that a high molecular weight polyester having excellent heat resistance is obtained when reacted with. The present inventors completed the present invention as a result of research experiments focusing on the effect of the chain extender.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT OF THE INVENTION The present invention is thermally stable, characterized in that the mixture of linear fusible nylon-46, bisoxazoline, and bisoxazione-based compounds are spun in a molten state in the presence of manganese phosphate and an alkali metal halide compound. A method for producing this excellent nylon-46 fiber.

The bisoxazoline compound used in the present invention has a structural formula such as the following formula (I), and specific examples thereof include 1, 3-phenylene-bis-2-oxazoline, 1, 4-phenylene-bis-2 -Oxazoline.

And the bisoxazionate mixture has a structural formula as shown in the following formula (II).

However, X is a divalent organic group, for example, a xylene group, a substituted methylene group, an ethylene group, an orthophenylene group, an ortphenylene group which has a substituent, etc. are mentioned.

In particular, in the present invention, it is more preferable to use 2,2'-bis (4H-3,1-benzoxazin-4-one) in which X is substituted with an ortphenylene group as the compound of formula (II).

In the present invention, the amount of bisoxazolin used (A) and the amount of bisoxazionone used (B) are preferably used to satisfy the following formulas (III) and (IV).

Below

However, the molecular weight of bisoxazolin using M ₁

CV ₁ : carboxyl terminal content of nylon-46 (eq / 10 ⁶ g)

M ₂ : Molecular weight of bisoxazionone

CV ₂ : amino-terminal content of nylon-46 (eq / 10 ⁶ g)

In fact, the molecular weight of the nylon resin -46 been used in the present invention is the relative viscosity of 3.63, an amino end group is 35eq / 10 ⁶ g, a carboxyl group was 19eq / 10 ⁶ g.

In addition, the bisoxazolin compound used in the present invention is 1,3-phenylene-bis-2-oxazoline, and the bisoxazionone compound is 2,2'-bis (4H-3,1-benzonazine-4- On), and its molecular weight is 216 g / mol and 292 g / mol, respectively.

Therefore, the actual usage ranges from 0.15 to 1.03% by weight for bisoxazoline and 0.38 to 2.55% by weight for bisoxazionone.

If bisoxazoline and bisoxazone are used less than the minimum dose, the degradation of properties due to pyrolysis cannot be prevented sufficiently. If the maximum dose is exceeded, the effect does not increase even if it is used more. It is not good because it decreases and operability worsens.

In the present invention, manganese phosphate and alkali metal halides (KI, KBr, etc.) are used for the purpose of preventing discoloration such as pyrolysis or yellowing by oxygen generated during melt processing, the amount of manganese phosphate is used as manganese ion (Mn ⁺⁺ ) is 100 to 1000ppm, more preferably 250 to 700ppm, and the amount of the halogen compound is preferably used 1 to 3 times the content of manganese ions (Mn ⁺⁺ ).

When the content of manganese ions in the manganese phosphate compound is less than 100 ppm and the content of the halogen compound is less than one time of the content of manganese ions, yellowing due to thermal decomposition cannot be prevented, and the content is more than 1000 ppm or more than three times. It is not good to expect any further thermal decomposition prevention effect, but rather, the mechanical properties of the nylon-46 fiber is degraded and the radioactivity is deteriorated.

In the present invention, when only manganese or a halogen compound is added to each other, the physical properties are less than that of adding nothing, but the effect is so insignificant that the object of the present invention cannot be achieved, and only the bisoxazoline or bisoxazionone compound is used. In each case, yellowing of undrawn yarn cannot be prevented after spinning. Therefore, only when the compound is used at the same time to prevent the yellowing phenomenon due to thermal decomposition, deterioration of the characteristics of the forma and can be produced nylon-46 excellent in thermal and mechanical properties even at high temperatures.

The following describes the present invention in more detail by examples.

Physical properties of the non-drawn yarn prepared according to Examples and Comparative Examples were measured by the following experimental method.

1. Relative viscosity

The sample was dissolved in 96% sulfuric acid to prepare a sulfuric acid solution having a concentration of 1%, and then measured at 25 ° C. using a Ubelrod viscometer.

2.-COOH terminal content

The sample was dissolved in ortho cresol at about 40 ° C. and then slowly raised to 150 ° C., then benzyl alcohol was added to the solution and immediately titrated with tetrabutyl ammonium hydroxide solution.

3.-NH ₂ terminal content

The sample was dissolved in phenol and titrated with hydrochloric acid.

4.melt viscosity

It measured at 20 mm / min at 305 degreeC using the capillary rheometer.

[Examples 1-3]

Nylon 46, which has a relative viscosity of 3.63, a carboxyl terminal content of 19eq / 10 ⁶ g, and an amino terminal content of 35eq / 10 ⁶ g, was added with the amount of manganese and KI as indicated in Table 1, and dried at 105 ° C. for 9 hours. The bisoxazoline and bisoxazionone compound were blended and spun at a spinning temperature of 305 占 폚 and a discharge amount of 120 g / min to obtain a nylon 46 unstretched yarn.

Relative viscosity, carboxyl end content, and melt viscosity were compared for this undrawn yarn.

TABLE 1

MBO in Table 1: m-phenylene-bis-2-oxazoline

BZO: 2, 2'-bis (4H-3,1-benzoxazin-4-one)

EXAMPLES 4-7

MBO and BZO were used in the same manner as in Example 1, except that 0.75% by weight and 2.50% by weight, respectively, were used in the amounts shown in Table 2.

TABLE 2

[Comparative Examples 1-7]

The same compound as in Example was used, and the addition amount thereof was performed in the same manner as in Example, except that Table 3 was added.

TABLE 3

Examples 1 to 7 have a melt viscosity of 1300 to 1600 poise followed by good radioactivity, but Comparative Examples 1 to 7 show a very poor radioactivity because the melt viscosity is 1300 or less.

In Comparative Examples 1 to 7, the heat resistance was poor because the amounts of the terminal -COOH and -NH ₂ were increased, but Examples 1 to 7 were excellent in the heat resistance because the amount was small.

In Comparative Examples 1 to 7, the color changed, but in Examples 1 to 7, the white color remained as it is.

Claims (5)

In preparing the nylon-46 fiber, a manganese phosphate or an alkali metal halide compound is added to a polytetramethylene adipamide resin, dried, and the bisoxazoline compound (I) and the bisoxazionone compound (II) A method of producing a nylon-46 fiber, characterized in that the melt-spinning by addition. Below

(X: divalent compound having an organic group) The method of producing a nylon-46 fiber according to claim 1, wherein the amount of the bisoxazolin compound (A) and the amount of the bisoxazionone compound (B) satisfy the following formulas (III) and (IV). Below

Provided that M ₁ : the molecular weight of bisoxazolin CV ₁ : Content of carboxyl terminal of nylon-46 (eq / 10 ⁶ g)

M ₂ : Molecular weight of bisoxazionone CV ₂ : amino-terminal content of nylon-46 (eq / 10 ⁶ g) The method of claim 1, wherein the amount of manganese phosphate added is 100 to 1000 ppm with respect to manganese ions (Mn ⁺⁺ ). The method of claim 1, wherein the alkali metal halide is KI, or KBr. The method for producing nylon-46 fibers according to claim 1 or 4, wherein the addition amount of the alkali metal halide is 1 to 3 times the manganese ion content in the manganese phosphate.