KR20100010130A - A process of producing polyketone fiber and a polyketone fiber produced by the process - Google Patents

Abstract

PURPOSE: A method for manufacturing polyketone fiber and the polyketone fiber produced thereby are provided to offer good intensity by preventing adhesion of single filaments, and to improve usability of the fiber in an industrial fields such as tire cord, a belt, and a hose etc. CONSTITUTION: A manufacturing method of polyketone fiber includes the following steps: manufacturing polyketone liquid by dissolving polyketone containing ketone 90 mole% or more; gaining multifilament by coagulating the polyketone liquid on a coagulation bath(S2); and drawing the multifilament with a washing, a drying and processing steps. The content of the polyketone liquid is 5 ~ 30 weight%.

Description

A process of producing polyketone fiber and a polyketone fiber produced by the process}

The present invention relates to a process for producing high strength polyketone fibers and to polyketone fibers produced by the method.

It is known that carbon monoxide and olefins such as ethylene and propylene are polymerized using transition metal complexes such as palladium or nickel as catalysts to obtain polyketones in which carbon monoxide and olefins alternate. The aliphatic polyketone is a polymer compound made from olefins such as ethylene and carbon monoxide as raw materials. The aliphatic polyketone is suitable for general purpose high performance plastics, has excellent impact resistance and chemical resistance at low temperatures, and has the same strength as para-aramid fibers. It has the advantage of having a good affinity with rubber. Due to the characteristics of these polyketones, it is expected that para-aramid fibers may be used for tire cords or rubber materials currently used exclusively.

Melting of high molecular weight polyketone causes thermal cross-linking reaction, which is not suitable for melt spinning. In general, wet spinning is preferable when fiberizing high molecular weight polyketone. When wet spinning polyketone, conventional organic solvents such as hexafluoroisopropanol and m-cresol have problems of toxicity and flammability, and fibers obtained by wet spinning using the solvent are likely to be divided, It has the disadvantage of insufficient fatigue resistance and processability for use.

In addition, in the case of using a metal salt aqueous solution such as zinc chloride, zinc bromide, lithium bromide, lithium iodide, lithium thiocyanate as a solvent, the solvent has a low dissolving power and it is difficult to produce a uniform spinning solution due to phase separation.

In addition, the washing tanks currently used in the fiber manufacturing process have not been studied in depth and do not effectively remove residual solvents. If you do not control the optimized form and flow rate of the washing liquid in the washing tank, the concentration of the extraction solvent in the washing liquid increases as the last stage of washing and as time passes, so the perfect washing effect of the remaining solvent is expected. In some cases, the flow of the washing liquid may cause damage to the yarn, resulting in a decrease in the physical properties. Insufficient solvent removal may result in high fusing of filaments, resulting in poor elongation and poor physical properties. As a range of the residual solvent which does not affect a physical property fall, it is 300 ppm or less, More preferably, it is 100 ppm or less.

In order to solve the above disadvantages, the content of polyketone is 5 to 30% by weight relative to the content of resorcinol, and the coagulation solution uses methanol, in particular, by controlling the conditions and speed of the coagulation stretching machine appropriately. The present invention provides a method for producing a polyketone fiber and a polyketone fiber produced therefrom, which makes the molecular structure dense while sufficiently removing the solvent and does not damage the yarn.

Method for producing a polyketone fiber according to the present invention comprises the steps of (A) dissolving in a polyketone containing at least 90 mol% of ketones in a repeating unit in an aqueous solution containing resorcinol to prepare a polyketone solution; (B) extruding the polyketone solution through a spinning nozzle, and then passing the air layer to reach a coagulation bath to solidify it to obtain a multifilament; And (C) washing and drying the multifilament, drying and emulsifying the secondary drawing, wherein the content of the polyketone in the step (A) is 5 to 30% by weight relative to the resorcinol content, Between the steps (B) and (C) is characterized in that it further comprises the step of first stretching the multifilament solidified in the step (B) using a coagulation stretching machine 2 to 7 times the draw ratio.

According to another preferred feature of the invention, the secondary stretching in step (C) comprises at least two stages of temperature increase step.

The polyketone fiber according to the present invention has a total denier of 500 to 3,000 denier, cutting load of 6.0 to 40.0 kg, strength of 15.0 to 30 g / d, elongation of 3 to 10%, and dry heat shrinkage of 0.5 to 3.0%.

The polyketone fibers prepared according to the present invention are suitable for use in industrial fiber fields such as tire cords, belts, hoses, ropes, etc. because the polyketone fibers prevent adhesion between single filaments and have a high molecular structure.

Hereinafter, the present invention will be described in detail by using the presented embodiments, and well-known or obvious items in the description of the embodiments are omitted or briefly described. However, such things should not be understood as limiting the scope of the present invention.

Hereinafter, with reference to the accompanying drawings will be described in detail the present invention.

Figure 1 shows a schematic process of the spinning process for producing a polyketone filament according to the present invention.

As shown in FIG. 1, the solution extruded from the spinning nozzle S1 is solidified in the coagulation bath S2 through an air gap in the vertical direction. The air gap is formed such that spinning is performed within a range of about 1 to 300 mm in order to obtain a dense and uniform fiber and to impart a smooth cooling effect.

The filament passed through the coagulation bath enters the coagulation stretching machine S100. Coagulation and stretching machine is located in the middle of the coagulation tank and flushing tank and refers to a device that stretches while solidifying by varying the speed of the two rollers. The introduction of this device increases the ability to clean in the early stages of the radiation yarn and makes the molecular structure dense, resulting in greater final strength. In the present invention, the stretching in the coagulation stretching machine is called primary stretching.

The filament passed through the solidification drawing machine passes through the washing tank (S3). The temperature of the coagulation bath (S2) and the water washing tank (S3) is adjusted using methanol to prevent a sudden desolvent. In addition, in order to improve the flushing performance of the washing tank, the flow of the washing liquid is made to flow in a direction opposite to the direction of the fiber flow. And the line flow rate of the wash liquid was maintained at 3 ~ 25m / min. After passing through the washing bath (S4) once more to remove the residual resorcinol after the washing step in the washing tank (S3), it passes through the dryer (S5). And the tanning process (S6) is subjected to a process containing the emulsion and additives.

In addition, the interlace nozzle was passed in order to improve flatness and improve focusability. The air pressure for the interlace nozzle was supplied to be 0.5-4.0 kg / cm ² and the number of entanglements per meter of filament was 2-40 times.

Thereafter, the filament yarn passing through the interlace nozzle is dried again using the drying apparatus S7. The drying temperature and drying method have a great influence on the post-processing and physical properties of the filament. According to the present invention, the drying temperature was adjusted so that the process water content could be about 7 to 13%.

Finally, the filament passed through the drying apparatus is finally wound up in the winder S8 via the secondary emulsion treatment apparatus.

In the manufacturing process of the polyketone fiber of the present invention manufactured through the above manufacturing process, the secondary stretching process after washing with water is very important for improving the high strength and hot water resistance. The heating method of the stretching process is hot air heating and roller heating, but hot air heating is more preferable for the production of high strength polyketone fibers because the filament is in contact with the roller surface and the fiber surface is easily damaged. When the hot air heating type is used, heating is possible at a temperature of 140 to 270 ° C, but preferably 160 to 260 ° C. If the heating temperature is less than 140 ℃, the molecular chain does not behave sufficiently, high magnification thermal stretching is impossible, and if it exceeds 270 ℃ polyketone is easy to decompose physical properties deteriorate.

Hereinafter, the polyketone constituting the polyketone fiber of the present invention manufactured through the manufacturing process as described above will be described. The polyketone is a major repeating unit of 90 mol% or more and includes a ketone unit represented by -CH ₂ CH ₂ -CO-. In addition, according to the present invention, repeating units other than the ethylene, for example, propylene, butylene, 1-phenylethylene repeating unit may be contained in less than 10 mol% based on the total repeating units.

However, since the strength, elastic modulus, dimensional stability, and heat resistance of polyketone fibers decrease when the amount of repeating units such as propylene other than the repeating unit of ethylene increases, the amount of the ketone units is preferably 95 mol based on the total repeating units. % Or more, More preferably, it is 98 mol% or more.

According to the invention it is most preferred that the polyketone fibers comprise only ketone units represented by -CH ₂ CH ₂ -CO-. In addition, the polyketone may optionally further include additives such as antioxidants, radical inhibitors, ultraviolet absorbers, flame retardants.

The polyketone polymer of the present invention has an intrinsic viscosity of 1 to 20 dl / g, preferably 3 to 10 dl / g. If the intrinsic viscosity is less than 1 dl / g, the strength or fatigue resistance of the polyketone fiber is not sufficient, and if the intrinsic viscosity is more than 20 dl / g, it is economically time-consuming and expensive, and uniformly dissolving It is difficult.

The polyketone polymer according to the present invention is prepared by the specific polymerization method described below. However, the following manufacturing method is intended to more clearly understand the present invention and is not intended to limit the scope of the present invention.

The autoclave was filled with methanol, and a catalyst solution prepared by stirring palladium acetate, 1,3-bis (di (2-methoxyphenyl) phosphino) propane and trifluoroacetic acid was added thereto. After the above process, the autoclave was charged with a mixed gas containing carbon monoxide and ethylene in a molar ratio of 1: 1, and the mixed gas was continuously added to maintain a pressure of 1 to 10 MPa while reacting at 50 to 100 ° C. for several hours. I was. After the completion of the reaction, the white polymer obtained by releasing the pressure was repeatedly washed with heated methanol and 1,3-pentanedione. The polyketone obtained through the above process was found to be poly (1-oxotrimethylene) by analysis of nuclear magnetic resonance spectra. In addition, it was found that the molecular weight distribution of the polyketone was 2.8, and the intrinsic viscosity was 5.0 dl / g.

The content of the polyketone in the polyketone solution of the present invention is such that the concentration is 5 to 30% by weight, more preferably 7 to 20% by weight, based on the degree of polymerization of the polyketone polymer. This is because when the polyketone polymer content is less than 5% by weight, it does not have physical properties as a fiber. On the other hand, when the content of the polyketone polymer is more than 30% by weight, it is difficult to dissolve it in an aqueous solution such as resorcinol and thus a homogeneous solution cannot be obtained.

In addition, an aqueous solution of resorcinol is used as a solvent for dissolving the polyketone, and the concentration of resorcinol in the aqueous solution of resorcinol is preferably 35 to 95% by weight. This is because when the concentration of resorcinol is less than 35% by weight, the solubility is inferior, and when the concentration of the resorcinol is greater than 95%, resorcinol is crystallized and it is difficult to prepare a uniform spinning solution. As a solvent for dissolving the resorcinol, water, methanol, ethanol, and the like may be used. In particular, water is used in the present invention because it is advantageous in terms of economics and solvent recovery.

Examples of preferred production methods that are not particularly limited with respect to the production method of the polyketone solution are described below, but the present invention is not limited to the above methods only.

The aqueous solution of resorcinol maintained at 40 to 80 ° C. is degassed at 200 torr or less, and then the polyketone polymer is dissolved by stirring for 0.5 to 5 hours in a vacuum at 200 torr or less.

In addition, in the present invention, the polyketone polymer may be used by mixing other polymer materials or additives. The polymer material may include polyvinyl alcohol, carboxymethyl polyketone, polyethylene glycol, and the like, and as an additive, a viscosity enhancing agent, titanium dioxide, silica dioxide, carbon, and ammonium chloride may be used.

The following describes in more detail a method for producing a polyketone fiber according to the present invention comprising the step of spinning, washing, drying and stretching with a homogeneous polyketone solution prepared using the above process. However, the following manufacturing method is illustrative.

Spinning process of the method according to the invention is carried out through the following process.

The spinning nozzle is provided with a plurality of orifices having a diameter of 100 to 500 µm and a length of 100 to 1500 µm, the ratio (L / D) of the diameter and length of the orifice is 1 to 3 to 8, and the interval between the orifices is 1.0 To 5.0 mm. Spinning stock solution is extrusion spinning through the spinning nozzle, the spinning fibrous spinning stock solution reaches the spinning bath through the air layer. Multifilament is obtained by solidifying the reached spinning stock solution in a coagulation bath.

The shape of the spinning nozzle used can generally be circular, and the nozzle diameter is 50 to 200 mm, preferably 80 to 130 mm. This is because when the nozzle diameter is less than 50 mm, adhesion may occur before the discharged solution solidifies because the distance between the orifices is too short. On the other hand, when the nozzle diameter is too large, peripheral devices such as a spinning pack and a nozzle are enlarged, which is disadvantageous to the equipment surface. to be. In addition, when the diameter of the nozzle orifice is less than 100 μm, a large number of trimmings occur during spinning, which adversely affects radioactivity. When the nozzle orifice exceeds 500 μm, the solidification rate of the solution in the coagulation bath after spinning is slow and resorcinol Desolvent and water washing of the aqueous solution becomes difficult.

In view of the application, especially for tire cords, and considering the orifice spacing for uniform cooling of the solution, the number of orifices is 100 to 2,200, more preferably 300 to 1,400.

If the number of orifices is less than 100, sufficient strength is not secured as an industrial company, and the fineness of each filament is thickened, so that the solvent cannot be sufficiently released within a short time, so that solidification and washing are not completed. If the number of orifices is more than 2,200, the filaments and affixes close to the filament are likely to occur in the air layer section, and the stability of each filament decreases after spinning, rather than the deterioration of physical properties. Can cause.

When the fibrous spinning stock solution passed through the spinning nozzle is solidified in the upper coagulating solution, the larger the diameter of the fluid, the greater the difference in the coagulation rate between the surface and the inside, thus making it difficult to obtain a dense and uniform fiber. Therefore, when spinning the polyketone solution, it is advantageous to allow the spun fibers to be obtained into the coagulating liquid with a smaller diameter while maintaining an appropriate air layer (air gap) even with the same discharge amount. The air layer is preferably 5 to 50 mm, more preferably 10 to 20 mm. Too short air gap distances (less than 10 mm) increase the fraction of microvoids during rapid surface layer solidification and desolvation, which hinders the increase in elongation ratio, while too long air gap distances (greater than 20 mm) are associated with filaments. It is difficult to maintain process stability due to relatively high influence of adhesion, atmosphere temperature and humidity.

In order to obtain a polyketone fiber having a high strength and excellent fatigue resistance and dimensional stability as a core technical matter in the present invention, yarns passing through a coagulation tank by a coagulation bath are first drawn while passing through rollers at different speeds. The introduction of this process enhances the cleaning effect, reducing the residual amount of resorcinol, densifying molecules, and ultimately increasing yarn strength. At this time, the draw ratio of the coagulation stretching machine is 1.5 to 15 times and more preferably 2 to 7 times. If the draw ratio is less than 2 times, the coagulation and stretching performance is insufficient, and the resorcinol's cleaning effect is reduced, which may cause fusing between the filaments. This is because the single yarn filament is broken, which may adversely affect the physical properties. At this time, the solidification stretching machine temperature is 20 ~ 80 ℃ and more preferably maintained at 40 ~ 60 ℃.

In the present invention, the dryer temperature is 100 ℃ or more, preferably 150 ℃ or more and impart an emulsion, heat-resistant agent, antioxidant or stabilizer to the fiber passed through the dryer.

In addition, the secondary stretching step after washing with water in the polyketone fibers of the present invention is very important for high strength and hot water resistance improvement. The heating method of the stretching process is hot air heating and roller heating, but in the case of the roller heating, the hot air heating is suitable for the production of high-strength polyketone fibers because the filament is easily in contact with the roller surface. In the case of the hot air heating type, heating is possible at a temperature of 140 to 260 ° C, but preferably 160 to 240 ° C. If the heating temperature is lower than 140 ℃, the molecular chain does not behave sufficiently, high magnification thermal stretching is impossible, and if it exceeds 260 ℃ polyketone is easy to decompose physical properties degradation.

The secondary stretching step after washing with water for stretching the polyketone fibers is performed in at least two stages. In addition, when performing multistage stretching, it is preferable that the temperature-stretching at which the stretching temperature gradually increases as the draw ratio is increased. As conditions for specific temperature extension, for example, the first stage is 180 to 200 캜, the second stage is 200 to 220 캜, and the third stage is 220 to 240 캜. The draw ratio of the present invention has a total draw ratio of 5 to 40 times, preferably 10 to 30 times.

The multifilaments produced by the process according to the invention are polyketone multifilaments with a total denier range of 500 to 3,000 and a cutting load of 6.0 to 40.0 kg. The multifilament is composed of 100 to 2200 individual filaments having a fineness of 0.5 to 8.0 denier. The strength of the multifilament is 15.0 to 30 g / d, elongation is 3 to 10%, dry heat shrinkage is 0.5 to 3%, it can be advantageously used as a tire cord for passenger cars.

Hereinafter, the configuration and effects of the present invention will be described in detail with specific examples and comparative examples, but the above examples are not intended to limit the scope of the present invention. In Examples and Comparative Examples, properties of the tire cord and the like were evaluated in the following manner.

(a) intrinsic viscosity

The intrinsic viscosity [IV] of the dissolved polyketone was measured using a Uberod viscometer in 0.5M hexafluoroisopropanol solution according to ASTM D539-51T at a temperature of 25 ± 0.01 ° C and a concentration range of 0.1 to 0.6 g / dl. . Intrinsic viscosity is obtained by extrapolating specific viscosity according to concentration.

(b) filament adhesion

Cut five pieces of filament yarn into 1m units and cut only 0.1m of them to make five samples, dry them at about 107 ℃ for 2 hours under no load, and then visually check the filament for adhesion through the image analyzer.

(c) Dry heat shrinkage (%, Shrinkage)

Dry heat shrinkage rate by using ratio of length (L ₀ ) measured at 20g super load and length (L ₁ ) after treatment at 20g static load for 30 minutes at 150 ℃ after leaving at 25 ℃, 65% RH for 24 hours. Indicates.

S (%) = (L ₀ -L ₁ ) / L ₀ × 100

(d) strength (g / d)

After drying at 107 ° C. for 2 hours, a twist of 80Tpm (80 twists / m) was added using a low-strength tensile tester of Instron, and then measured at a sample length of 250 mm and a tensile speed of 300 m / min.

<Example>

Example 1

12.0 wt% of a polyketone polymer (POK) having an intrinsic viscosity of 5.0 dl / g was added to an aqueous solution containing 75 wt% of resorcinol, and the mixture was reduced under reduced pressure at 60 ° C. to 100 torr for 30 minutes to remove bubbles.

After the air bubbles in the aqueous solution were completely removed, the resultant was sealed under reduced pressure, and then heated to 80 ° C. and stirred for 3 hours to obtain a transparent polyketone polymer spinning solution. After passing the obtained polyketone polymer spinning solution through a filter, a speed of 20 m / min at 80 ° C. as a trench type extruder through a nozzle (N / Z) having a diameter of 0.2 mm, L / D 2.0, and 200 holes. Extruded. After the extrusion was passed through an air layer (Air Gap) having a length of 10mm to cause a solidification in the coagulation bath.

The fiber passed through the coagulation bath was stretched 2 to 7 times through the coagulation stretching machine to have a more compact structure and higher strength. After passing through the coagulation stretching machine, the fibers were dried by passing through a hot air dryer at 200 ° C. after washing with a water bath. In the washing bath, methanol was washed in a counter current flow to increase the washing effect. At this time, the flow linear velocity of methanol was maintained at 10 m / min. Thereafter, the fiber obtained by applying an oil agent, an antioxidant, and the like to the wound was subjected to three-stage stretching while gradually raising the temperature at 180 ° C, 210 ° C, and 225 ° C, and the final filament fineness was adjusted to 1,000 denier.

The filament drawn yarn was evaluated for physical properties using an Instron company's low-speed stretch type tester.

Example 2

Undrawn and drawn yarns were prepared by performing experiments in the same manner as in Example 1 while changing the line flow rate of methanol in the water bath as shown in Table 1 below. The residual amount of resorcinol as a solvent of the unstretched yarn thus prepared was analyzed using HPLC, and the physical properties of the stretched yarn were evaluated and shown in Table 1 below.

   < Comparative example  >

[Comparative Examples 1, 2, 3]

A stretched yarn was prepared by performing an experiment in the same manner as in Example 1 while changing the draw ratio of the coagulation and stretching machine as shown in Table 1. The resorcinol content was analyzed as a solvent of the non-drawn yarn prepared as described above, and the physical properties of the drawn yarn were evaluated and shown in Table 1 below.

TABLE 1

Example 1 Example 2 Comparative Example 1 Comparative Example 2 Comparative Example 3 Polyketone Intrinsic Viscosity (/ g) 3.1 3.1 3.1 3.1 3.1 Extrusion Temperature (℃) 80 80 80 80 80 Primary draw ratio of solidification drawing machine 2 5 One 10 15 Resorcinol Residues in Unstretched Yarn (ppm) 100 70 500 30 10 State between filaments Good Good Welding envoy Partial envoy Yarn fineness (denier) 1000 1800 2000 800 1800 2nd draw ratio 15 15 8 7 5 Strength (g / d) 19 20 10 9 7 Elongation (%) 3.7 4.0 4.4 3.8 4.1 Dry Heat Shrinkage (%) 1.3 1.5 1.3 1.0 2.0

Based on the test results of Table 1, the polyketone fibers (Examples 1 and 2) prepared when the coagulation and stretching machine were applied according to the present invention and the draw ratio was in the range of 2 to 7 times were not used. Compared to Comparative Examples 1 to 3 in which the draw ratio is other than 2 to 7 times, the residual amount of resorcinol in the undrawn yarn or the yarn is good, the draw ratio is high, and the strength is high, and the single filament Sticking of the liver can be prevented.

1 is a schematic diagram of a spinning process for producing polyketone filaments of the present invention.

Claims (3)

(A) preparing a polyketone solution by dissolving the ketone in a polyketone containing at least 90 mol% of ketones in an aqueous solution containing resorcinol; (B) extruding the polyketone solution through a spinning nozzle, and then passing the air layer to reach a coagulation bath to solidify it to obtain a multifilament; And (C) a method for producing a polyketone fiber comprising the step of stretching by washing, drying and emulsion treatment of the multifilament, The content of polyketone in the step (A) is 5 to 30% by weight relative to the resorcinol content, and the multifilament solidified in the step (B) between the step (B) and (C) Method for producing a polyketone fiber characterized in that it further comprises the step of stretching at a draw ratio of 2 to 7 times using a coagulation stretching machine. The method according to claim 1, wherein the stretching in step (c) comprises a step of raising at least two stages. According to the method according to claim 1, the total denier is 500 to 3,000 denier, the cutting load is 6.0 to 40.0 kg, the strength is 15.0 to 30 g / d, the elongation is 3 to 10%, and the dry heat shrinkage is 0.5 to 3.0%. Polyketone fibers produced.

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