KR20170085877A - High-strength Nylon 66 filament having excellent strength ratio - Google Patents

Abstract

The present invention relates to a nylon 66 high-strength fiber, which is related to the properties of super-high tenacity (SHT) fibers of nylon 66 and which can exhibit a high tensile strength by producing a tensile elastic modulus of 40 d / g or less. The nylon 66 high strength fiber having high strength utilization produced by the present invention can produce fibers having low elastic modulus at the fracture site, high yarn strength and high cutting elongation by controlling yarn manufacturing process conditions, Sewing thread, rope, hose reinforcement, and the like.

Description

High-strength nylon 66 filament having excellent strength ratio [

The present invention relates to a nylon 66 high-strength fiber, which is related to the properties of super-high tenacity (SHT) fibers of nylon 66 and which can exhibit a high tensile strength by producing a tensile elastic modulus of 40 d / g or less.

Nylon 66 is a polyamide produced by polycondensation of hexamethylenediamine and adipic acid. It is widely used in medical and industrial textile, plastic molding, etc., and has excellent properties such as automobile airbag fabric, sewing thread, It is a material for which demand is widely demanded. In the case of producing a yarn using pure nylon 66 chips, a gel-like material is generated inside the prepolymer due to the reaction between hexamethylenediamine and adipic acid and various side reactions, and various subsequent processes Causing problems. In this way, the gel present in the polymerized phase continues to grow in a cyclic or three-dimensional manner in the solid-phase polymerization step, and further grows and develops in the melting and spinning stages, and at the same time, a new gel is formed and spherulite is generated in the melt- It is. If such a gel is generated, it is caught in a spinning pack and a nozzle filter, and the spinning workability such as shortening of the filter replacement cycle is lowered. A gel having a small size is included in the undrawn yarn to reduce the drawability in the drawing process, There is a problem that it acts as a factor to lower the workability in the weaving process of the automobile airbag fabric and the like.

Korea Patent Publication No. 2010-0021790

An object of the present invention is to develop a yarn in which the slope of the fracture site, that is, the modulus of elasticity of the fracture site is limited to 40 g / d or less in the production of nylon 66 high strength fiber having high strength utilization.

According to a preferred embodiment of the present invention, in the high-strength industrial nylon 66 fiber for industrial use, the elastic modulus at the fracture site is 40 g / d or less, the relaxation rate is 4 to 5%, and the relaxation zone temperature is 240 to 280 ° C Provides high strength nylon 66 high strength fibers. At this time, the yarn strength is 11 g / d or more, the cut elongation is 15 to 28%, and the strength utilization ratio of D / C is 85% or more.

The nylon 66 high strength fiber having high strength utilization produced by the present invention can produce fibers having low elastic modulus at the fracture site, high yarn strength and high cutting elongation by controlling yarn manufacturing process conditions, Sewing thread, rope, hose reinforcement, and the like.

The nylon 66 yarn produced by the present invention has the characteristics that the strength of the final yarn is 11 g / d or more, the elongation at break is 15% or more and the strength utilization ratio of D / C is 85% or more. 40 g / d or less.

The nylon 66 used in the present invention has a level of 2.8 to 3.6, and as the relative viscosity of the polymer is higher, it is advantageous in high-intensity expression.

A method for producing nylon 66 high strength fiber according to the present invention will be described below.

The nylon 66 high-strength fiber of the present invention can be manufactured by a spin-draw process in which a melt melted in an extruder is radiated through a spinneret and is then passed through a multi-stage roller while simultaneously performing stretching-heat fixing-relaxation.

Specifically, the present invention relates to a process for producing a poly (hexamethylene adipamide) comprising (A) melt extruding polyhexamethylene adipamide containing 85 mol% or more of hexamethylene adipamide repeating unit through spinneret, (B) (C) winding the softening yarn through the multi-stage stretching, heat treatment and relaxation of the non-twisted yarn to obtain a nylon 66 high-strength fiber.

The polyhexamethylene adipamide polymer used in the present invention contains at least 85 mol% of repeating units of hexamethylene adipamide and preferably consists only of hexamethylene adipamide units.

Alternatively, any polyamide homopolymer and copolymer may be used in place of the polyhexamethylene adipamide. Such polyamides are predominantly aliphatic. Poly (hexamethylene adipamide) (nylon 66); Poly (e-caproamide) (nylon 6); And widely used nylon polymers such as copolymers thereof can be used. Nylon 66 is the most preferred. Other nylon polymers that may be advantageously used are nylon 12, nylon 46, nylon 6. 10, and nylon 6. 12.

The polyhexamethylene adipamide chip may be added in an amount such that the residual amount of the copper metal in the final polymer is 50 to 80 ppm in order to improve the thermal stability. If the amount is less than 50 ppm, the thermal stability upon spinning falls If it exceeds 80 ppm, more copper than necessary will act as a foreign substance, which is a problem in spinning.

The polyhexamethylene adipamide chips are fiberized according to the method of the present invention.

In step (A), the polyhexamethylene adipamide chips are passed through the pack and nozzle, preferably at a spinning temperature of from 270 to 310 DEG C, preferably from 20 to 200, of a radiation draft ratio (linear velocity / The linear velocity at the nozzle), it is possible to prevent the viscosity of the polymer from lowering due to thermal decomposition. If the radiation draft ratio is less than 20, the uniformity of the filament cross section is deteriorated to deteriorate the drawing workability remarkably. If it exceeds 200, filament breakage occurs during spinning, and normal yarn production becomes difficult.

Further, in the present invention, adjusting the filtration retention time in the pack to 3 to 30 seconds is an important factor. If the filtration retention time in the pack is less than 3 seconds, the filtering effect of the foreign substance is insufficient, and if it is more than 30 seconds, the pyrolysis is severe due to excessive packing pressure increase.

Further, in the present invention, it is preferable to set the L / D (length / diameter) of the extruder screw to 10 to 40. If the L / D of the screw is less than 10, uniform melting is difficult. If it exceeds 40, The lowering of the molecular weight is severe and the physical properties are deteriorated.

In step (B), the molten discharge of step (A) is quenched and solidified by passing through a cooling zone.

In the cooling zone, an open quenching method, a circular closed quenching method, and a radial outflow quenching method can be applied according to a method of blowing cooling air, quenching method is preferable. The solidified discharged yarn 4 can then be oiled to 0.5 to 1.0% by the emulsion applying device 5 while passing through the cooling zone 3.

In step (C), the preferred spinning speed of the unstretched yarn is 200 to 1,000 m / min.

In the step (D), the yarn passed through the first stretching roller 6 is passed through a series of stretching rollers 7, 8, 9 and 10 by a spin draw method, Is drawn to 4.5 to 6.5 to obtain a final drawn yarn.

On the other hand, in the case of producing nylon 66 high-strength yarn by the spin-draw method, nylon 66 copolymer chips having a relative sulfuric acid viscosity of 2.7 to 3.4 are melted in an extruder and transferred to a spinneret through a gear pump, Then, an emulsion is applied by using an emulsion applying device, and the emulsion is radiated at a spinning speed of 400 to 1,000 m / min, and then stretched, heat fixed and relaxed while passing through a plurality of pairs of high-defect rollers. At this time, the free draw ratio between the first and second high-deflection rollers and the second high-deflection roller is 1.01 to 1.08, the first-stage stretching ratio between the second and third high-deflection rollers is 2.5 to 3.5, The stretching ratio between the rollers and the fourth felt rollers is 1.5 to 2.5, the total stretching ratio is adjusted to a level of 4.0 to 6.0, and a stretching speed of 2,100 to 4,000 m / min . The temperature of the first high detent roller is at room temperature, the temperature of the second high detent roller is in a range of from room temperature to 90 DEG C, the temperature of the third high detent roller is in a range of 120 to 200 DEG C, the temperature of the fourth high detent roller is in a range of 180 to 230 DEG C, It is preferable that the temperature of the fifth high deterioration roller is from room temperature to 150 deg.

Here, the relaxation rate is set to 4 to 12% in the yarn manufacturing process, the relaxation temperature is set to 150 to 280 ° C, and the elasticity of the broken portion is made to be 40 g / d or less according to the spin draft and the stretching ratio . Since the tenacity of the yarn is closely related to the slope of the yarn breakage region, it is preferable to fabricate the nylon 66 high strength fiber so that the modulus of elasticity at the breaking site is 40 d / g or less.

The nylon 66 high strength yarn manufactured by the method of the present invention can be used as an aircraft tire or a special industrial material.

The present invention will be described in more detail with reference to the following examples and comparative examples. EXAMPLES The following examples and comparative examples are for illustrative purposes only and are not to be construed as limiting the scope of the present invention.

The measurement conditions for the analysis items in the results of the following Examples and Comparative Examples are as follows.

(1) Relative viscosity (I.V.)

0.1 g of the sample was dissolved in sulfuric acid (90%) for 90 minutes so as to have a concentration of 0.4 g / 100 ml, transferred to a Ubbelohde viscometer, maintained in a thermostatic chamber at 30 ° C for 10 minutes, and the resultant was subjected to a viscometer and an aspirator To obtain the falling seconds of the solution. The number of drops of the solvent was also determined by the same method, and then the RV value was calculated by the following equation.

R.V. = Samples falling in water / solvent drops in seconds

(2) The power of God

After standing for 24 hours or more in a standard state (20 ° C, 65% relative humidity) according to ASTM D 885 using an Instron 5565 (Instron, USA), a sample length of 250 mm, a length of 300 mm / And a tensile strength of 80 turns / m.

(3) Elasticity at break

The elastic modulus at the fracture site was measured by the slope of the segment at the (cutting-2) to the cutting segment.

(4) D / C Strong Utilization Rate

D / C Strength Utilization (%) = D / C Strength / (Yarn Strength x Ply Number) x 100

Example 1

A polyhexamethylene adipamide chip having a relative viscosity (RV) of 3.4, each containing 80 ppm of copper metal, was melt-spun using an extruder at a temperature of 296 占 폚 at a radiation draft ratio of 20. At this time, the retention time of the filtration in the pack was 17 seconds. In the used extruder, the screw was adjusted to L / D of 35 and a static mixer having two units was installed in the polymer conduit of the pack to mix the melt-spun polymer uniformly. Then, the discharged yarn was solidified by passing through a cooling zone having a length of 600 mm, followed by oiling with a spinning oil. This unstretched yarn was wound at a spinning speed of 470 m / min and stretched in two stages. The final stretching ratio of 1890d denier was prepared by heat setting (relaxation temperature) at a total stretching ratio of 6.0 and relaxation of 8% followed by winding.

Comparative Example 1

A spinning lug was produced in the same manner as in Example 1, except that Spin Draft was changed.

Comparative Example 1 Example 1 Relative viscosity (R.V.) 3.0 3.0 Denier 1890 1890 Spin Draft 30 20 Stretching cost 6.15 6.0 Strength (d / g) 9.6 11 Cutting Elongation (%) 13.5 18.2 D / C Strong Utilization Rate (%) 80 89 Elastic modulus at break (g / d) 41 35

In Example 1, nylon 66 high strength fiber having a strength of 11 g / d was obtained as compared with Comparative Example 1, and the breaking elongation and the strength utilization ratio were also superior to those of Comparative Example 1. Also, in the case of the elastic modulus at the fracture site, Example 1 was lower than Comparative Example 1, and overall Example 1 exhibited a higher strength utilization ratio than Comparative Example 1.

Unless specifically defined otherwise herein, all terms used herein, including technical or scientific terms, have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. Terms such as those defined in commonly used dictionaries are to be interpreted as having a meaning consistent with the contextual meaning of the related art and are to be interpreted as either ideal or overly formal in the sense of the present application Do not.

Claims (2)

For industrial high strength nylon 66 fibers,
And a modulus of elasticity at the fracture site is 40 g / d or less.
The method according to claim 1,
Wherein the nylon 66 high strength fiber has a yarn strength of 11 g / d or more, a cutting elongation of 15 to 28%, and a dope cord (D / C) of 85% or more.