JPH06184302A - Production of nylon 66 as industrial fiber - Google Patents

Abstract

(57) [Summary] [Structure] A liquid phase polymerization of hexamethylene diammonium adipate is carried out by adding phenylphosphonic acid and / or its metal salt. After that, a copper compound is added and solid-phase polymerization is carried out to obtain an acidic component amount (A millimol / kg) and a basic component amount (B
Millimol / kg) produces nylon 66 polymer for industrial materials fibers with AB = 5-25. [Effect] By spinning, fatigue resistance, strength,
Nylon 6 for industrial materials with excellent elongation, weather resistance, heat resistance, etc.
6 fibers are obtained. Moreover, it is possible to suppress yarn breakage during spinning and increase in filtration pressure of the spinning machine, and to suppress troubles during spinning.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing nylon 66 for industrial material fibers, which is effective for producing industrial material fibers having excellent fatigue resistance and strength / elongation property.

[0002]

BACKGROUND OF THE INVENTION Nylon 66 is a polyamide which is widely used for applications such as fibers and plastics together with nylon 6. Textile applications are broadly divided into clothing applications such as innerwear and industrial applications such as tires, hoses, belts and airbags. Among them, the fibers used for industrial purposes include strength, elongation, fatigue resistance, heat resistance,
It is required to have excellent properties such as weather resistance and abrasion resistance.

Generally, the mechanical properties such as the strength of the fiber are improved as the degree of polymerization of nylon 66 constituting the fiber is increased,
Further, properties such as heat resistance and weather resistance of the fiber are significantly improved by adding a stabilizer such as a copper compound. Therefore, these stabilizers are added to nylon 66 for manufacturing industrial material fibers, and are generally added before or during liquid phase polymerization.

Further, as a polymerization catalyst for the liquid phase polymerization,
Various phosphorus compounds have been used. For example, a hypophosphorous acid derivative such as phenylphosphinic acid and sodium phenylphosphinate having an antioxidant effect has been proposed (US Pat. No. 3,929,725).

[0005]

However, nylon 66 obtained by such a conventional polymerization method does not have sufficient fatigue resistance and strength / elongation characteristics when it is used to produce fibers for industrial materials. Problem that you can not get it,
There has been a problem that the heat resistance of the polymer itself is insufficient and gelation is likely to occur during melt spinning.

Therefore, the present invention solves the above-mentioned problems of the prior art and makes it an industrial material fiber excellent in fatigue resistance and strength / elongation property, and is useful for industrial material fiber nylon 6
The main purpose is to provide a method for producing 6-polymers.

A further object of the present invention is to produce a nylon 66 polymer for industrial material fibers which has excellent heat resistance and can prevent spinning problems such as gelation during melt spinning.

[0008]

To achieve this object, the present invention provides a liquid phase polymerization of hexamethylene diammonium adipate to form nylon 66 using phenylphosphonic acid and / or its metal salt as a catalyst. A method for producing nylon 66 for fibers of industrial materials by adding a copper compound and solid-phase polymerizing, wherein the amount of acidic component (A millimol / kg) and basic component of nylon 66 after the solid-state polymerization is (B millimol / kg) is adjusted to an amount satisfying the following formula.

5 ≦ A−B ≦ 25 Here, the amount of acidic component (A millimol / kg) and the amount of basic component (B millimol / kg) of nylon 66 are measured by the following method.

Amount of basic component (B millimol / kg): Nylon 66 polymer was pulverized, and 1 g of the polymer was shaken at room temperature in 40 to 50 ml of phenol / ethanol mixed solvent (ethanol 20 ml / phenol 80 g mixture ratio). The solution is dissolved to form a solution, and this solution is neutralized and titrated with 0.02N hydrochloric acid to obtain the required amount of 0.02N hydrochloric acid. Further, only the above phenol / ethanol mixed solvent (the same amount as above) was neutralized and titrated with 0.02N hydrochloric acid to determine the required amount of 0.02N hydrochloric acid. Then, from the difference, the basic component amount (B millimol / kg) per kg of the polymer is obtained.

Amount of acidic component (A millimol / kg): Nylon 66 polymer was pulverized and then 0.5 g of the polymer was added to 196
A solution is prepared by dissolving it in 20 ml of benzyl alcohol at ± 1 ° C, and this solution is neutralized and titrated with a 0.02N potassium hydroxide ethanol solution to obtain the required amount of the 0.02N potassium hydroxide ethanol solution. Further, only 20 ml of the above benzyl alcohol was neutralized and titrated with a 0.02N potassium hydroxide ethanol solution to obtain the amount of the required 0.02N potassium hydroxide ethanol solution. And from the difference, polymer 1
Determine the amount of acidic component per kg (A millimol / kg).

In the present invention, nylon 66 for industrial material fibers is used.
It is important to control the liquid phase polymerization conditions so that the difference between the amount of acidic component (A) and the amount of basic component (B) in the polymer falls within the above-mentioned specific range. Further, the polymerization catalyst used for the liquid phase polymerization is phenylphosphonic acid and / or
Alternatively, it is necessary to use phenylphosphonic acid metal salt.

When the difference (A-B) between the amount of acidic component (A) and the amount of basic component (B) in the polymer exceeds 25 millimol / kg, even if the degree of polymerization is within the proper range, the fiber Fatigue resistance is poor and a sufficient GY life cannot be obtained.

On the contrary, when the basic component amount (B) is larger than the acidic component amount (A) (B> A) or the difference (A-).
If B) is less than 5 millimol / kg, the crosslinking reaction of the polymer is likely to occur, and foreign matter having an extremely high degree of polymerization is generated in the spinning machine during melt spinning, which shortens the life of the spinning filter and increases the frequency of thread breakage. This causes operational troubles such as stable spinning.

Since the liquid phase polymerization of the AH salt is usually carried out in an aqueous solution system, hexamethylenediamine is distilled out along with the distillation of water and condensed water in the raw material AH salt. In addition, an acidic component and a basic component are generated during the polymerization due to the side reaction of the polymerization. Therefore, the ratio of adipic acid units and hexamethylenediamine units constituting the nylon 66 polymer obtained at the end of the liquid phase polymerization is not the same as that in the raw material AH salt, and the aqueous solution concentration of the raw material AH salt and the polymerization conditions It depends on the situation.

Therefore, the amount of the acidic component and the amount of the basic component in the nylon 66 polymer can be adjusted by changing the conditions, but hexamethylenediamine or adipic acid can be used before or during the liquid phase polymerization. Is easily added, and the amount of addition can be adjusted easily.

Amount of hexamethylenediamine and / or adipic acid added for the purpose of adjustment (vs. raw material AH salt)
Can be determined in consideration of other polymerization conditions such as the ratio of hexamethylenediamine and adipic acid forming the raw material AH salt, the aqueous solution concentration of the raw material AH salt, and the polymerization conditions. Generally, hexamethylenediamine may be added when the amount of acidic component of the polymer is too large, and conversely, adipic acid may be added when the amount of basic component is too large.

Further, the phosphorus compound added to the liquid phase polymerization system as a polymerization catalyst is phenylphosphonic acid and / or its metal salt in order to obtain a filament yarn excellent in strength and elongation. The metal salt is preferably soda salt or potassium salt.

A part of the phosphorus compound added during the liquid phase polymerization is decomposed and remains as phosphoric acid in the obtained nylon 66 polymer and further in the fiber obtained therefrom. Since the phosphoric acid contained in the fiber adversely affects its strength, in the case of industrial material fiber, it is preferable to keep the amount of phosphoric acid low, for example, a level of 3 ppm or less is preferable.

On the other hand, in order to exert the function as a polymerization catalyst in liquid phase polymerization, it is necessary to add a certain amount or more of a phosphorus compound, and in the case of phenylphosphonic acid and / or its metal salt, other phosphorus compounds are added. As in the case, it is necessary to add at least about 50 ppm as phosphorus to the polymer.

However, in the case of phenylphosphonic acid and / or its metal salt, the amount of phosphoric acid contained in the fiber should be kept small compared to the case of using other phosphorus compounds such as phenylphosphinic acid. And as a result,
The strength of the fiber can be improved.

However, even if phenylphosphonic acid and / or its metal salt is used, it is difficult to suppress the amount of phosphoric acid in the fiber if the amount added is too large. It is preferable to suppress it to about 150 ppm.

Nylon 66 obtained by solid phase polymerization
The degree of polymerization is preferably 2.8 to 4.5 in terms of sulfuric acid relative viscosity ηr in order to obtain fibers for industrial materials. When ηr is less than 2.8, the properties such as strength of the industrial material fiber obtained by spinning are not sufficient, and conversely, when ηr exceeds 4.5, the elongation of the obtained fiber is drastically decreased and the fiber becomes industrial material. Would be inappropriate.

In order to obtain a nylon 66 polymer having ηr in the above range, 1 to 5 Torr · abs is obtained after liquid phase polymerization.
Nylon 6 under high pressure or under an inert gas such as nitrogen
Solid phase polymerization may be performed at a temperature of 6 melting points or less.

Here, the sulfuric acid relative viscosity ηr is the viscosity of a solution prepared by dissolving 1 g of polymer in 100 cc of 98 wt% sulfuric acid,
Ratio to 98% sulfuric acid viscosity.

The heat-resistant copper compound must be added after the liquid phase polymerization and before the solid phase polymerization, and is preferably added to the pellets after the liquid phase polymerization.

On the other hand, when a copper compound is added during the liquid phase polymerization, metallic copper or the like is likely to precipitate during the polymerization due to the reducing action of nylon, and is insoluble in the polymer due to the polymer gelation promoting effect of the copper compound. Gelation of the polymer is likely to occur, causing troubles such as an increase in stains in the polymerization vessel, an increase in filter filtration pressure in the spinning machine, and an increase in yarn breakage in the spinning process. Appropriate.

Examples of the copper compound include copper acetate,
Copper iodide, copper bromide, or the like can be used, and the addition amount thereof may be about 50 to 100 ppm with respect to the polymer as copper.

[0029]

When a nylon 66 polymer for industrial material fibers is produced by performing liquid phase polymerization and solid phase polymerization under the conditions specified in the present invention, it is possible to improve fatigue resistance and elongation, which are important for industrial material fibers. In addition, heat resistance is good, gelation during melt spinning is suppressed, and yarn breakage during spinning and increase in spinning machine filtration pressure can be suppressed.

On the other hand, adjustment of the amount of the acidic component and the amount of the basic component of the nylon 66 polymer for fibers is carried out for various purposes, but these amounts affect the fatigue resistance of the industrial material fiber. That wasn't known.

Therefore, in the present invention, the difference (AB) between the amount of the acidic component and the amount of the basic component is 5 to 25 mmol /, from the viewpoint of improving the fatigue resistance of the industrial material fiber, especially the GY life.
It is a specific level of less than kg.

Furthermore, studies were conducted from the viewpoint of producing nylon 66 polymer suitable for fibers for industrial materials. Phenylphosphonic acid and / or its metal salt is preferable as the phosphorus compound of the polymerization catalyst during liquid phase polymerization. It has been found that the copper compound is preferably added after liquid phase polymerization and before solid phase polymerization. By satisfying these conditions, a nylon 66 polymer for industrial materials, which can obtain nylon 66 fibers having excellent physical properties for industrial materials with good spinnability, was obtained.

[0033]

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

The physical properties in the following examples are measured as follows.

Amount of basic component of nylon 66 polymer (mm
mol / kg); Nylon 66 polymer was crushed, passed through a JIS mesh sieve for 850 μm, and sieved under the condition of 150 μm residue to obtain nylon 66 powder, which was dried for 30 minutes by a hot air dryer at 105 ± 3 ° C. After that, it was used as a measurement sample and determined by the method described above.

Amount of acidic component of nylon 66 polymer (millimo
l / kg); Nylon 66 powder which was crushed, sieved and dried in the same manner as above was used as a measurement sample and determined by the method described above.

Degree of gelation of polymer (wt%); Nylon 6
The 6 polymers were heated at 290 ° C. under N ₂ gas flow for 6 hours and then dissolved in 98% sulfuric acid, and the ratio of the amount of insoluble polymer was taken as the gelation degree of the polymer.

Amount of phosphoric acid in the fiber (ppm): The filament was dissolved in 90% formic acid and measured by phosphorous molybdate blue method.

GY life of fiber (min); JIS-L-
It was measured according to the method of 1017.

Yarn breakage during spinning (times / ton): The number of yarn breakage during spinning is shown in terms of per ton of spinning polymer.

[Examples 1, 2, 3 and Comparative Examples 1, 2] 80
% AH salt aqueous solution was subjected to liquid phase polymerization by a usual method under the condition of heating at 300 ° C. for 2 hours. At that time, the AH salt was charged into a polymerization vessel, and immediately after that, phenylphosphonic acid (10% in terms of phosphorus) was charged.
0 ppm, relative to polymer) and hexamethylenediamine or adipic acid in the amounts shown in Table 1 were added to the polymerization vessel.
The obtained nylon 66 polymer was pelletized, 80 ppm of copper acetate was added to the polymer in terms of copper, and 5 Torr.
Nylon 66 polymer was obtained by carrying out solid-state polymerization in the usual way under the pressure of abs at 160 ° C.

The obtained nylon 66 polymer was melt-spun and stretched by a usual method to obtain a filament yarn having a denier of 1890 (the number of filaments was 306).

Characteristic values of the obtained nylon 66 polymer and filament yarn are shown in Table 1.

As is clear from the results of Table 1, in the case of Examples 1, 2 and 3 in which the relationship between the amount of basic component and the amount of acidic component of nylon 66 polymer is within the range specified in the present invention,
The heat resistance of the polymer was good, the degree of gelation was small, and the GY life of the yarn was good.

On the other hand, in the case of Comparative Example 1 in which the amount of the basic component of the polymer was too large as compared with the amount of the acidic component, the gelation degree of the polymer was high and the heat resistance was poor. On the contrary, in Comparative Example 2 in which the basic component amount of the polymer was too small compared to the acidic component amount, the heat resistance of the polymer was good, but the GY life of the obtained fiber was inferior.

[0046]

[Table 1] [Examples 4, 5 and Comparative Example 3] Nylon 66 polymer was obtained by liquid-phase polymerization and solid-phase polymerization in the same manner as in Example 1 except that the type and addition amount of the phosphorus compound were changed as shown in Table 2. Melt spinning and drawing were performed. Then, the obtained nylon 66 polymer and filament yarn were evaluated, and the results are shown in Table 2. The amount of acidic components and the amount of basic components of the polymer were the same as in Example 1.

As is clear from the results in Table 2, the strength of the obtained filament yarn was good in Examples 4 and 5 using phenylphosphonic acid.

On the other hand, in Comparative Example 3 using phenylphosphinic acid, the strength of the filament yarn obtained was inferior to Examples 4 and 5 using phenylphosphonic acid.

[0049]

[Table 2]

[0050]

INDUSTRIAL APPLICABILITY The nylon 66 polymer obtained by the method of the present invention is a nylon 66 for industrial materials which is excellent in fatigue resistance, strength, elongation, weather resistance, heat resistance and the like by spinning.
It can be a fiber. Further, it is possible to suppress yarn breakage during spinning and increase in filtration pressure of the spinning machine, and reduce troubles during spinning.

Therefore, the method of the present invention is useful for producing nylon 66 polymer which is a raw material for industrial fibers.

Claims (1)

[Claims] 1. Industrial material fibers prepared by liquid-phase polymerizing hexamethylene diammonium adipate into nylon 66 using phenylphosphonic acid and / or its metal salt as a catalyst, then adding a copper compound and solid-phase polymerizing. A method for producing nylon 66 for use in which the amount of acidic component (A millimol / kg) and the amount of basic component (B millimol / kg) of nylon 66 after the solid-state polymerization are adjusted to satisfy the following formulas: A method for producing nylon 66 for industrial materials, which comprises adjusting. 5 ≦ A−B ≦ 25