KR101310139B1 - Method of manufacturing aramid multi-filament - Google Patents

Abstract

The present invention relates to a method for producing an aramid multifilament, wherein the uneven layer is formed on the surface of the dried multifilament when the aramid multifilament is produced by spinning, passing through the non-coagulated layer, coagulation, washing, drying and winding Wind up the embossed branch.

The winding paper tube of the aramid multifilament produced by the present invention has the effect that the winding stability is maintained as it is even after the residual moisture contained in the winding paper pipe evaporated into the atmosphere during post-processing.

Aramid, Multifilament, Embossing Branch, Winding, Winding Stability, Moisture Content

Description

Method of manufacturing aramid multifilament {Method of manufacturing aramid multi-filament}

The present invention relates to a method for producing aramid multifilament.

The present invention relates to a method for producing aramid multifilament that can improve the winding stability of the tire take-up tube.

Aramid multifilament is disclosed in U.S. Patent Nos. 3,869,429 and 3,869,430, and the like to polymerize an aramid polymer by polymerizing aromatic diamine and aromatic dieside chloride in a polymerization solvent containing N-methyl-2-pyrrolidone. And a process for producing a spinning stock solution by dissolving the polymer in a concentrated sulfuric acid solvent, and spinning the spinning stock solution from a spinneret to pass the spun spinning material through a non-coagulant fluid layer into a coagulating bath to form a filament. And a process of washing the filament with water and drying the same, and winding the dried multifilament into a common branch pipe having no irregularities on its surface.

The aramid multifilament manufactured by the conventional manufacturing method as described above is useful as a yarn for tire cords with high strength and modulus, but the moisture remaining in the winding bobbin is in the process of conveying or weaving yarns for manufacturing tire cords. As the evaporation during the post-process, the winding stability is greatly reduced, there is a problem that the dead layer collapses.

On the other hand, the tire cord serves to reinforce the tire rubber as one of the components of the tire, and forms a basic skeleton structure in the tire.

The performance required for the cord as a tire reinforcement is fatigue resistance, shear strength, durability, resilience and adhesion to rubber. Therefore, the appropriate code is used according to the performance required for the tire.

Currently commonly used cord materials include rayon, nylon, polyester, steel and aramid.

To manufacture tire cord, give twist (Z-lead) twist to yarn (multifilament) for tire cord manufacture, and then ply it while twisting while giving twist (S-lead) twist to two strands of twisted yarn to manufacture raw cord. Then, it is subjected to a process of immersing, drying and heat-treating the adhesive solution for manufacturing a tire cord.

The raw cord manufacturing process is called a "ply twisted yarn process".

As described above, when the aramid multifilament manufactured by the conventional method is wound on a common winding tube having no irregularities on its surface, the winding stability of the winding tube is insufficient, resulting in a problem of collapse of the four layers during the twisted yarn weaving process. .

According to the present invention, the dried aramid multifilament is wound on a paper pipe (hereinafter referred to as an "embossing paper pipe") having irregularities formed on its surface, so that the winding stability is excellent even when the remaining level in the winding pipe evaporates, such as during transportation or combined weaving process. It provides a method for producing aramid multifilament to effectively prevent the phenomenon that the four layers collapse in the same post-process.

Hereinafter, the present invention will be described in detail.

In the method for producing aramid multifilament according to the present invention, when the aramid multifilament is prepared by spinning, passing through a non-coagulated layer, solidifying, washing, drying and winding the aramid spinning stock solution as shown in FIG. It is wound up in the embossed branch pipe in which the irregularities are formed.

1 is a process schematic diagram of preparing aramid multifilament according to the present invention.

Hereinafter, the present invention will be described in detail.

In general, when the aramid multifilament is wound in the winding tube, the aramid multifilament wound the moisture content remaining in the winding tube to prevent the generation of static electricity due to friction between the aramid multifilament and the guide during the post-process, such as the twisted yarn weaving process More than 10% by weight has been managed.

However, when the dried aramid multifilament as in the conventional method is wound on a conventional paper tube having no unevenness on the surface, there is a problem that the winding stability worsens due to excessive evaporation of moisture remaining in the winding paper tube and the sand layer collapses. .

In the present invention, in order to solve the above conventional problems, by winding the dried aramid multifilament in the embossed paper tube, it is possible to maintain a good winding stability even if the moisture remaining in the wound tube evaporates, thereby transporting or after It is possible to effectively prevent the collapse of the four layers of the winding tube during the process.

The filament bundle produced by spinning is referred to as 'multifilament', and the raw cord manufactured by the upper and lower edges (or lower and upper edges) of the multifilament is referred to as a 'ply-twisted yarn' and a tire cord to the ply-twisted yarn. Deep cords in the finished state treated with a solvent adhesive are called "tire cords" or "codes".

Specifically, in the present invention, a poly (para-phenylene terephthalamide) polymer is prepared by polymerizing an aromatic diamine and an aromatic dieside chloride in a polymerization solvent containing N-methyl-2-pyrrolidone, as shown in FIG. Dissolving the polymer in a concentrated sulfuric acid solvent to form a spinning stock solution, spinning the stock solution from a spinneret, and passing the spun spinning material through a non-coagulating fluid layer into a coagulant bath to form a multifilament, wherein the multifilament Was washed with water and dried, and the dried multifilament was wound on an embossed branch pipe to produce aramid multifilament.

In this case, the aromatic diamine is P-phenylenediamine and the like, and the aromatic dieside chloride is terephthaloyl chloride and the like.

The polymerization solvent is N-methyl-2-pyrrolidone or the like in which calcium chloride is dissolved.

The intrinsic viscosity of the aramid (fully aromatic polyamide) polymer is 5.0 or more is good for improving the strength and elastic modulus of the filament.

The aramid polymer may be prepared using known polymerization conditions disclosed in US Pat. No. 3,869,429, etc., but the present invention does not specifically limit the polymerization conditions of the aramid polymer.

One example of preparing the polymer is a solution of 1 mole of para-phenylenediamine dissolved in N-methyl-2-pyrrolidone containing about 1 mole of calcium chloride and 1 mole of terephthaloyl chloride in a polymerization reactor. After the addition, it is stirred to prepare a gel polymer, which is ground, washed with water and dried to prepare a fine powder aramid polymer. At this time, the terephthaloyl chloride may be added to the reactor for polymerization divided into two stages.

The concentration of concentrated sulfuric acid used in the production of the spinning stock solution is preferably 97% to 100%, and chlorosulfuric acid, fluorosulfuric acid, and the like may also be used.

At this time, when the concentration of sulfuric acid is less than 97%, the solubility of the polymer is reduced and the liquid crystalline expression of the anisotropic solution becomes difficult. Therefore, it is difficult to manufacture a spinning solution having a constant viscosity, which makes it difficult to control the process during spinning and to provide mechanical properties of the final fiber. Can be degraded.

On the other hand, if the concentration of the concentrated sulfuric acid exceeds 100%, gwari (過離) because in oleum containing SO _3, as well as undesirable phase handled becomes an SO ₃ over takes place is partly dissolved in the polymer spinning solution to the inadequate and In addition, even if the fiber is obtained by spinning, there may be a problem that the internal structure of the fiber is not dense, the appearance is not gloss, and the speed of sulfuric acid diffused into the coagulation solution is lowered, thereby lowering the mechanical properties of the fiber.

On the other hand, the concentration of the polymer in the spinning stock solution is preferably 10 to 25% by weight for the fiber properties.

However, the present invention does not specifically limit the concentration of concentrated sulfuric acid and the concentration of the polymer in the spinning stock solution.

The non-coagulating fluid layer may mainly be an air layer or an inert gas layer.

The length of the non-coagulating fluid layer, that is, the distance between the bottom surface of the spinneret 40 and the surface of the coagulating liquid contained in the coagulating liquid bath 50 is preferably 0.1 to 15 cm to improve the properties of the radioactive or filament.

The coagulant in the coagulant bath 50 may overflow. As the coagulating solution, water, brine or an aqueous sulfuric acid solution having a concentration of 70% or less is used.

At this time, the spinning winding speed is set to 300 to 1500 m / min.

The strength of the aramid multifilament according to the present invention is 10 ~ 25g / d, when less than 10 g / d, the strength is low, it is difficult to support the vehicle load when applied as a tire cord, the problem of the performance of the tire is impossible, 25 If it exceeds g / d, problems may arise that are not efficient enough to develop tire performance.

In addition, the cut elongation of the aramid multifilament is 2 ~ 6%, if less than 2% due to the low cutting elongation occurs a problem that the fatigue characteristics are insufficient to be applied to the tire cord, when the stability exceeds 6% form stability This scarce problem can occur.

In addition, as the modulus of the aramid multifilament 400 ~ 750 g / d, less than 400 g / d, due to the low modulus, the problem of lack of expression of support capacity for high-speed driving during tire production occurs, exceeding 750 g / d In the case of a high modulus may cause a difficult tire molding.

It is preferable that the total fineness of the aramid tire cord is 800 to 10,000 denier, and the aramid multifilament preferably has a total fineness of 400 to 5,000 denier and is composed of 500 to 1,200 aramid monofilaments. Moreover, it is preferable that the single yarn fineness of the said aramid monofilament is 1-2 denier.

Various physical properties of the aramid multifilament is measured by the following method.

Strength (g / d) and Elongation (%)

According to ASTM D-885 test method, the strength (g) at the time of fracture of the sample yarn was measured using a sample yarn having a length of 25 cm in an Instron Engineering Corp. (Canton, Mass), and then the sample yarn was denier. The strength was calculated by dividing. Elongation at break was calculated as the ratio of the length of the sample yarn to the length of the sample yarn until the sample yarn was broken. The strength and the elongation at break were taken as the average value after five tests. At this time, the tensile speed was 300 mm / min, and the initial load was 1/130 g of fineness.

· Modulus (g / d)

The stress-strain curve of the sample yarn is obtained under the above-described strength measurement conditions, and then calculated from the slope on the stress-strain curve.

Looking at an example of a method for producing an aramid tire cord with aramid multifilament according to the present invention, the aramid multifilament having the following physical properties by using an Alma twister for a tire cord as shown in Figure 2 counterclockwise After giving a twisting edge (Z edge) twist, the twisted two strands are twisted while giving the twist direction Syeon twist (S edge) twisted clockwise as shown in Figure 3 to produce a twisted yarn.

2 to 3 are diagrams showing the definition of the upper edge (Z edge) and the lower edge (S edge), respectively.

At this time, the twist number of each of the upper (Z) and the lower (S) is preferably 20 to 60 times / 10 cm.

When the number of twists is less than 20 times / 10cm, the strength is low because the number of twists is high, but the cutting elongation is very low, so that the fatigue characteristics of the cord are bad and the adhesion may be poor as the surface area is lowered.

If the number of twist exceeds 60 times / 10 cm may cause a problem that the strength of the tire cord is reduced due to excessive twist.

Next, the aramid-ply-twisted yarn spliced as described above is immersed in a conventional resorcinol-formaldehyde-latex (RFL) solution so that the pickup ratio is 3 to 12% by weight based on the aramid-ply-twisted yarn. Bath dipping can be used.

Examples of RFL adhesive solution used in the present invention include 2.0% by weight of resorcinol, 3.2% by weight of formalin (37%), 1.1% by weight of sodium hydroxide (10%), styrene / butadiene / vinylpyridine (15/70/15) An RFL adhesive solution comprising 43.9% by weight of rubber (41%), and water is used.

In the present invention, as an example of the adhesive liquid for the adhesive strength of the aramid cord and the rubber can be prepared and used as described above, the above examples are only intended to more clearly understand the present invention, it is intended to limit the scope of the present invention no.

When the pickup rate is less than 3% by weight, the adhesive strength with rubber is lowered. When the pickup rate is more than 12% by weight, the penetration rate of the RFL solution (immersion liquid) in the cord is too high, the strength is low, and the fatigue property is lowered. Various properties of the can be lowered.

Next, the yarn in which the RFL solution is immersed is dried at 105 to 200 ° C. for 10 seconds to 400 seconds, and then heat-treated at 105 to 300 ° C. for 10 seconds to 400 seconds to prepare an aramid tire cord.

When the drying time and the heat treatment time are each lower than the above range, or when the drying temperature and the heat treatment temperature are each below the above range, a low adhesive force may occur.

When the drying time and the heat treatment time each exceed the above ranges, or when the drying temperature and the heat treatment temperature respectively exceed the above ranges, the adhesive force is reduced due to excessive thermal history. The problem of low physical properties may occur.

In the drying process, the moisture present in the aramid multifilament is dried, and in the heat treatment process, the impregnation solution is reacted to impart adhesion to the tire cord.

The wound paper tube of the aramid multifilament produced by the present invention can prevent the phenomenon that the four layers of the wound paper pipe collapses during the post-processing, such as conveying or twisted yarn yarn process.

Therefore, the aramid multifilament according to the present invention is useful for producing aramid tire cord and the like.

Hereinafter, preferred embodiments of the present invention will be described. However, the following examples are only preferred embodiments of the present invention, and the present invention is not limited to the following examples.

Example  One

An aromatic diamine solution was prepared by maintaining 1,000 kg of N-methyl-2-pyrrolidone at 80 ° C. and dissolving 80 kg of calcium chloride and 48.67 kg of para-phenylenediamine.

The aromatic diamine solution was introduced into the polymerization reactor 20, and at the same time, a molten terephthaloyl chloride of an equimolar amount of para-phenylenediamine was simultaneously introduced into the polymerization reactor 20, followed by stirring them to have an intrinsic viscosity of 6.8. Poly (para-phenyleneterephthalamide) polymer (aramid polymer) was prepared.

Next, the prepared aramid polymer was dissolved in 99% concentrated sulfuric acid to prepare an optically anisotropic radiation stock solution having a polymer content of 18% by weight.

Next, after spinning the spinning stock solution prepared as described above at a spinning winding speed of 1,000 m / min through the spinneret 40 as shown in Figure 1, the radiated spinning material is air layer of 7 mm (non-coagulation) Fluid layer), and then passed through a coagulation bath 50 containing a sulfuric acid aqueous solution (coagulant) having a sulfuric acid concentration of 13% to prepare aramid multifilament.

Next, the multifilament formed as described above was washed with water and dried, and then wound into an embossed branch pipe to prepare aramid multifilament.

Table 1 shows the results of evaluating the various physical properties of the aramid multifilament prepared by the above method and the winding stability of the aramid multifilament wound up.

Comparative Example  One

Aramid multifilament was prepared in the same manner as in Example 1 except that the dried multifilament was wound on a conventional paper tube having no irregularities on its surface instead of the embossed paper tube.

Table 1 shows the results of evaluating the various physical properties of the aramid multifilament prepared by the above method and the winding stability of the aramid multifilament wound up.

Results of physical property evaluation division Example 1 Comparative Example 1 Aramid
Multifilament Properties Monofilament
(Pcs / m) 1,000 1,000 Average fineness
(Denier) 1.5 1.5 Strength (g / d) 22.3 22.3 Modulus (g / d) 7.4 7.4 Cutting Elongation (%) 3.2 3.2 Winding stability
Good
Bad

Winding stability of Table 1 was evaluated by the following method.

· Winding stability

When the aramid multifilament wound winding tube was pressed vertically by applying a force of 5kgf / cm 2, it was evaluated as good if the slipped (collapse) phenomenon of the wound four layers did not occur, and poor when the slip (collapse) phenomenon occurred.

1 is a process schematic diagram of producing aramid multifilament according to the present invention.

2 to 3 show the definition of the upper and lower edges.

Claims (5)

In preparing the aramid multifilament by spinning, passing through the non-coagulated layer, coagulating, washing, drying, and winding the aramid spinning solution, 500 to 1,200 aramid monofilaments are formed of irregular aramid multifilament on the surface thereof. A method for producing an aramid multifilament, characterized by winding on an embossed branch pipe. The method for producing aramid multifilament according to claim 1, wherein the aramid multifilament has a strength of 10 to 25 g / d, an elongation at break of 2 to 6%, and a modulus of 400 to 750 g / d. The method for producing aramid multifilament according to claim 1, wherein the total fineness of the aramid multifilament is 400 to 5,000 denier. delete The method for producing aramid multifilament according to claim 1, wherein the single yarn fineness of the aramid monofilament is 1 to 2 denier.

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