KR950000727B1 - Nylon-6 fiber and manufacturing method thereof - Google Patents

Abstract

The high strength polycaproamide fiber having at least 8.0 g/d tenacity, 15-30 % elongation, at least 25 g/d initial modulus, 1-4 % (150 deg.C × 30 min) dry shrinkage ratio, at least 0.91 crystalline orientation degree and at most 0.70 amorphous orientation degree is produced by (a) adding a 2-mercapto-4,5,6,7- tetrahydor-benziimidazole (HMBI), a complex salt of the HMBI and a copper iodide (CuI) or a complex salt of a 2-mercaptobanziimidazole and the CuI to a high polymerization degree polyamide comprising at least 95 mol% ε-caproamide unit, (b) spinning the mixture at least 1500 m/min, (c) passing a filament through a heating zone and a cooling zone, (d) heating it with 400-1000 deg.C steam, and (e) taking it up on the take-up roller. The nylon-6 fiber has a good dimensional stability and fatigue resistance.

Description

Nylon 6-based fiber and its manufacturing method

1 is a manufacturing process schematic diagram of the present invention.

2 is a perspective view of a heating apparatus used in the present invention.

The present invention relates to a nylon 6-based fiber and a method for producing the same, and more particularly, to a polycaproamide-based fiber having excellent durability and fatigue resistance to light, heat and oxygen, and a low shrinkage rate, and a method for manufacturing the same.

Conventional high strength yarns have a high shrinkage ratio of yarns, so when used as rubber reinforcement materials such as tires and belts, there are disadvantages in dimensional stability and fatigue resistance, and when used as industrial materials such as fishing nets, the durability is not good. Therefore, in the manufacture of high strength yarns, it is a big problem to lower the shrinkage of yarns. As a method of lowering the shrinkage of the yarn, a method of stretching by increasing the orientation of the undrawn yarn by high-speed spinning is known, but since the draw ratio decreases as the orientation of the undrawn yarn increases, the shrinkage ratio is lowered, but the strength is lowered. There are other ways to decrease the shrinkage rate by increasing the relaxation rate, but when relaxing the stretched yarn, increasing the relaxation rate by more than about causes problems in four-way running, or trimming, which greatly reduces workability.

On the other hand, durability is also important for industrial use, but conventionally, copper (Cu) and complex salts of copper salts and various organic compounds have been used, but a satisfactory effect could not be obtained. Copper salts react with the amide groups of the polyamide fiber to form a bond between the polyamide polymer chains, thereby increasing the binding force of the polymer chain, thereby providing more resistance to the decomposition of radicals caused by light or heat. However, since this method only inhibits decomposition, a method of using a mercapto compound as a method of decomposing radicals causing decomposition by a chain reaction has been proposed. In recent years, various attempts have been made to achieve synergistic effects with mercapto compounds, but even with these efforts, the best conditions for maximizing durability against light, heat and oxygen have not been suggested.

The present inventors have tried to solve the problems of the prior art as described above and to provide a high strength polycaproamide fiber with excellent fatigue resistance by lowering the shrinkage rate even better, after inserting the selected stabilizer in the polymer of high polymerization degree and spinning the nozzle It was possible to achieve the polycaproamide-based fiber of the present invention and a method for producing the same, which are prepared by heating directly below, followed by quenching, heating with steam directly under the exhaust port, and hot stretching it.

The present invention is described in more detail as follows.

The present invention is a nylon 6-based polymer, 95 mol% or more of the molecular chain structural unit is epsilon-caproamide (ε-Caproamide), the copolymerization component contains less than 5 mol%, using an Ostwald viscometer, 25 ℃, polymer concentration 1 It is characterized by using a polymer of high polymerization having a relative sulfuric acid viscosity of 3.0 or more, preferably 3.2 or more, measured under the conditions of% by weight. Next, 2-mercapto-4,5,6,7-tetrahydro-benzimidazole (HMBI) 0.01-1 for the purpose of giving durability to heat, light and oxygen required for tire cord and industrial use Complexation of 2-mercapto-4,5,6,7-tetrahydro-benzimidazole with iodine copper (CuI) (HMBI / CuI complex salt) or complexation of 2-mercaptobenzimidazole with copper iodide ( MB / CuI complex salt) is added so that the weight percentage of copper (Cu) is 10-300ppm. By using the above additives, it was possible to produce high strength yarns having excellent dimensional stability and shrinkage rate while improving durability compared with conventional copper salts and complex salts of copper salts with organic compounds. In the spinning method of the present invention, a section (heating zone of FIG. 1) of 10-100 cm immediately below the spinning nozzle is maintained at the melting temperature. That is, the atmosphere temperature of the section to maintain 250-300 ℃. After cooling the yarn passed through the above section with air and blowing steam at 40-100 ℃ just below the hole for exhausting the air in the spinning tube, the birefringence of the yarn when passing through the winding roller should be 0.025 or more. Wind up at a winding speed of 2000-3500m / min. When the nylon 6 fiber has a spinning speed of less than 1500 m / min, 2000-3500 m / min is a suitable spinning speed because the intermediate orientation region of the molecular chain develops and absorbs and swells during winding. Conventionally, since heat is applied in the stretching roller, sufficient heat cannot be given to lower the shrinkage rate. However, the present invention can significantly reduce the shrinkage rate because the temperature condition is controlled at the temperature condition in the winding step before the stretching process.

By stretching the yarn past the winding roller with an elongation ratio of 4.0 or less, high strength yarn with excellent dimensional stability and fatigue resistance is completed. The physical properties of the polycaproamide fiber obtained by the above method are as follows.

1) Strength: 8.0g / d or more

2) Elongation: 15-30%

3) Initial Modulus: 25g / d or more

4) Dry heat shrinkage: 1-4% (150 ℃, 30 minutes treatment)

5) Crystal orientation: 0.91 or more

6) Non-orientation: 0.70 or less

Polycaproamide yarn of the present invention prepared in this way is low shrinkage, excellent fatigue resistance and high strength, so high strength cords such as tire cords, power transmission belts, transport belts and sheet bells, sewing thread, fishing nets, various reinforced composite materials It can be used widely.

[Examples 1,2 and Comparative Examples 1-3]

When comparing the method of this invention with the manufacturing method of the usual polyamide fiber, it is as follows.

[Table 1] Radiation and New Year Conditions

Physical properties of the examples and comparative examples obtained by the method of Table 1.

[Table 2] Physical Properties

(1) 1. Shrinkage is measured after treatment at 150 ℃ for 30 minutes in dry oven without load.

2. Strength and elongation were measured with a tensile tester under conditions of 25cm, TPM 80, and 30m / min of tensile velocity.

[Table 3] Heat Resistance Comparison

1.MB: 2-mercaptobenzimidazole

HMBI: 2-mercapto-4,5,6,7-tetrahydro-benzimidazole

2. The strong residual rate is calculated by the following formula after stretching the drawn yarn at 180 ℃ for 4 hours or 40 hours.

Claims (3)

2-mercapto-4,5,6,7-tetrahydro-benzimidazole, 2-mercapto-4,5,6, to a high degree of polymerization polyamide having a structural unit of epsilon-caproamide of not less than 95 mol% The complexing salt of 7-tetrahydro-benzimidazole and copper iodide, or the complex salt of 2-mercaptobenzimidazole and copper iodide was added to spin at a spinning speed of 1500 m / min or more, and maintained at the melting temperature. After passing through the 10-100cm section and cooled, the method for producing a nylon 6-based fiber, characterized in that it is heated again by steam directly under the exhaust port in the spinning tube. 2. The method according to claim 1, which is contained in the addition of the 2-mercupato-4,5,6,7-tetrahydro-benzimidazole and copper iodide complex, or the complex salt of 2-mercaptobenzimidazole and copper iodide. A method for producing a nylon 6-based fiber, characterized in that the weight percent of copper (Cu) is added to 10-30ppm. Nylon 6-based fiber with the following properties. next ⑴ Strength: 8.0g / d or more ⑵ elongation: 15-30% ⑶ Initial modulus: 25g / d or more ⑷ 1-4% of dry heat shrinkage (at 150 ℃ for 30 minutes) ⑸ Crystal orientation: 0.91 or more 정 non-orientation: 0.70 or more

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