KR20110009366A - Process for effective drawing polyketone fibers - Google Patents

Abstract

PURPOSE: A method for manufacturing a polyketone filament of high intensity is provided to produce tire cord, belt, hose and rope. CONSTITUTION: A method of manufacturing a polyketone filament comprises: a step of dissolving a polyketone in a resorcinol aqueous solution to obtain a polyketone solution; a step of removing bubbles from the polyketone solution; a step of extruding and spinning the polyketone solution through a spinning nozzle; a step of passing an air layer for coagulation to obtain a multi-filament; and a step of washing, drying and emulsion-treating the multi-filament. The content of the polyketone is 5-30 weight% based on resorcinol content.

Description

Process for effective drawing Polyketone Fibers

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

It is known that polyketones in which carbon monoxide and olefins are interchanged are obtained by polymerizing carbon monoxide with olefins such as ethylene and propylene using a transition metal complex such as palladium or nickel as a catalyst. The aliphatic polyketone is a polymer compound based on olefins such as ethylene and carbon monoxide. The aliphatic polyketone is not only suitable for general purpose high-performance plastics but also excellent at low temperature impact resistance and chemical resistance, and has the same strength as para-aramid fibers. In addition to having, it has the advantage of having good affinity with rubber. Due to the characteristics of these polyketones, it is expected that para-amide fibers may be used for tire cords or rubber materials currently used exclusively.

Melting high molecular weight polyketone causes thermal cross-linking reaction, which is not suitable for melt spinning. Generally, when spinning high molecular weight polyketone, wet spinning is preferred. In the case of wet spinning polyketone, conventional organic solvents such as hexafluoroisopropanol and m-cresol have problems in toxicity and flammability, and fibers obtained by wet spinning using the solvent are liable to be divided, It is disadvantageous in that fatigue resistance and processability are insufficient for use as an industrial yarn.

In addition, in the case of using a metal salt solution such as zinc chloride, zinc bromide, lithium bromide, lithium iodide, lithium thiocyanate as a solvent, the solvent has a low solubility and phase separation, which makes it difficult to prepare a uniform spinning solution. In addition, the fiber prepared using such a solvent can remove the solvent contained on the fiber using water, alcohol or acetone as a coagulation liquid in the coagulation step, but at this time, the difference in the coagulation speed between the fiber surface and the center is large. The core structure has a problem that it is difficult to produce a polyketone fiber having a uniform and dense structure.

The present invention provides a homogeneous polyketone solution by dissolving a polyketone containing at least 90 mol% of ketone units in a repeating unit in an aqueous solution containing resorcinol, and heating the uniform filament obtained from the polyketone solution by short heating. The present invention provides a method for producing polyketone fibers having excellent strength by stretching them economically and efficiently and providing the polyketone fibers produced by the above methods.

According to a preferred embodiment of the present invention to achieve the above object, (A) dissolving a polyketone containing at least 90 mol% ketone units in a repeating unit in a solution of lesosinol to prepare a polyketone solution; (B) uniformly dissolving the polyketone solution by extrusion spinning through a spinning nozzle, passing through an air layer to reach a coagulation bath, and solidifying it to obtain a multifilament; (C) washing, drying and tanning the multifilament; And (D) stretching the multifilament in three stages by a roller heating method, wherein the polyketone content is 5 to 30% by weight relative to the content of resorcinol, and the stretching is hot air in a roller heating method. It provides a method for producing a polyketone fiber, characterized in that the temperature 220 ~ 280 ℃, the temperature of the contact roller 180 ~ 240 ℃.

According to another preferred embodiment of the invention, the diameter of the spinning nozzle is 50 to 200 mm, and the number of orifices of the spinning nozzle is 100 to 2200.

According to another preferred embodiment of the invention, the stretching is characterized in that it comprises at least two heating step.

In addition, the polyketone fibers produced according to the present invention is characterized in that (1) the strength of 15 to 30 g / d, (2) the fineness of 500 to 3,000 denier, (3) the elongation of 3 to 10%.

Polyketone fibers prepared according to the present invention can significantly reduce the total length of the stretching machine compared to the conventional method, and can produce industrial fibers such as tire cords, belts, hoses, ropes and the like having excellent strength by only three-stage stretching.

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 being excluded from 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 passes through an air gap in a vertical direction (S1) and is solidified in a coagulation bath (S2). The air gap is formed such that spinning is performed in the 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 (S2) is passed through the washing tank (S3). The temperature of the coagulation bath and the washing tank I is controlled by using a mixed solvent of methanol and water to prevent a sudden desolvent. After passing through the water bath (S4) to remove the residual resorcinol after the step (S3), it is passed through the dryer (S5). In addition, the tanning agent undergoes a process (S6) of containing an emulsion and an additive.

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 a 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 0.5 to 2%.

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

The stretching process in the polyketone fibers of the present invention produced through the above manufacturing process 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 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. However, when the hot air heating type is used, the length of the heating field is very long, which causes a problem of increased investment cost. In order to solve this problem, a roller heating drawing machine in which hot air heating is mixed is used. At that time, the hot air temperature can be heated at 200 to 300 ° C. and the contact roller at 160 to 260 ° C., but preferably the hot air temperature is 220 to 280. The temperature of 180 degreeC and 240 degreeC of a contact roller is suitable. When the temperature of the contact roller is less than 180 ° C, the molecular chain is not sufficiently behaved, so high magnification thermal stretching is impossible.

Figure 2 shows a schematic process of a roller heating stretching machine mixed with a hot air heating formula for producing a polyketone filament according to the present invention.

Hereinafter, the polyketone constituting the polyketone fiber of the present invention manufactured through the manufacturing process as described above will be described. The polyketone comprises ketone units represented by -CH ₂ CH ₂ CO- as the main repeating unit of 90 mol% or more. In addition, according to the present invention, repeating units other than ethylene, for example, propylene, butylene, and 1-phenylethylene repeating units, may be contained in an amount of 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 fibers of the present invention have an intrinsic viscosity of 1 to 20 dl / g, preferably 2 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 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 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 content of the polyketone polymer 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 may be from 35 to 95% by weight, but preferably from 55 to 85% by weight. . It is inferior in solubility when the concentration of resorcinol is less than 55% by weight, and crystallization of resorcinol occurs when the concentration of resorcinol is 95% or more, which makes it difficult to prepare a uniform spinning solution and has a disadvantage of spinning at high temperature. This is because the polyketone lowers the physical properties. As a solvent for dissolving the resorcinol, water, methanol, ethanol, and the like may be used. Particularly, the use of methanol and water is used due to the effective washing of the water and the problem of fast drying.

Examples of preferred production methods that are not particularly limited with respect to the production method of the polyketone solution are described below.

After dissolving the aqueous solution of resorcinol maintained at 40 to 80 ° C. under a vacuum for 0.5 to 5 hours, the polyketone polymer was obtained after degassing by thin film evaporation under -700 mmHg to -450 mmHg. However, preferably, defoaming under -650 mmHg to -600 mmHg is more preferable for improving the strength. The thin film evaporation method flows the dissolved dope solution onto the high pressure film deposition apparatus, and the dope solution flows down the wall and forms a thin film on the surface of the device through the stirrer. Such a thin film effectively removes bubbles in a short time, thereby minimizing polyketone deterioration.

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 the 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. At this time, the air layer is preferably 5 cm or less, more preferably 2 cm or less. Solidification of the reached spinning stock solution in a coagulation bath yields a multifilament.

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, if the diameter of the nozzle orifice is less than 100 μm, a large number of trimmings occur during spinning, which adversely affects radioactivity. If 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 the appropriate air layer 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 increase the rate of micropores generated during rapid surface layer solidification and desolvation, which hinders the increase in elongation ratio, while too long air gap distances are associated with filament adhesion, atmospheric temperature, and humidity. It is difficult to maintain the stability of the process.

The process stability is maintained by controlling the distribution of polyketone according to the mixing ratio of the emulsion. The mixing ratio of the emulsion is 1: 9 to 9: 1, preferably 3: 7 to 8: 2.

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 order to obtain polyketone fibers having high strength as a key technical matter in the present invention and minimizing investment cost, roller heating stretching technology becomes an important factor. For example, when using only the hot air heating stretching method, it is necessary to perform four-stage stretching, and a heating field is required over 100 m. However, using the roller heating stretching method requires a heating field of 50m or less by only three-stage stretching, so that an economical and efficient stretching process can be performed. Therefore, in the present invention, using a roller heating stretching method to be 50m or less in the heating field. More preferably, it is drawn to less than 35m to minimize the equipment investment cost. It is possible to use a roller heating drawing machine in which the hot air heating type is mixed, and the hot air temperature can be heated at a temperature of 200 to 300 ° C. and a temperature of 160 to 260 ° C. of the contact roller. The temperature of 180-240 degreeC is suitable. When the temperature of the contact roller is less than 180 ° C, the molecular chain is not sufficiently behaved, so high magnification thermal stretching is impossible, and at 240 ° C or higher, polyketone is easily decomposed, which leads to deterioration of physical properties.

The stretching is carried out in one or two or more stages of multistage for stretching the polyketone fibers. 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 of specific temperature extension extending | stretching, for example, 1st stage is hot air temperature 220-240 degreeC, roller temperature 180-200 degreeC, 2nd stage hot air temperature 240-260 degreeC, roller temperature 200-220 degreeC, and 3rd stage hot air temperature It is 260-280 degreeC and roller temperature 220-240 degreeC. The draw ratio of the present invention has a total draw ratio of 5 to 40 times, preferably 10 to 30 times. In addition, the length of the stretched heating field is shorter and more efficient than in the past. At that time, the length of the first stage is 5 to 10 m, the length of the second stage is 10 to 15 m, and the length of the third stage is preferably 15 to 20 m.

The multifilaments produced by the process according to the invention are polyketone multifilaments with a total denier range of 500 to 3,500 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 5.0 to 30g / d, elongation is 3 to 10%, shrinkage of 0.5 to 3%, it can be advantageously used as a tire cord for a passenger car.

Hereinafter, the configuration and effects of the present invention will be described in detail with specific examples and comparative examples, but the above embodiments 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 an image analyzer. do. At this time, if one strand is stuck, it is determined as 'fail (F)', otherwise 'pass (P)'.

(c) Dry heat shrinkage (%, Shrinkage)

After leaving for 24 hours at 25 ° C. and 65% RH, the dry heat shrinkage ratio is shown using the ratio of the length (L 0) measured at 20 g of super load and the length (L 1) after treatment at 150 g for 20 minutes at a static load of 30 g.

S (%) = (L0-L1) / L0 × 100

(d) strong (kgf)

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 1

12.0 wt% of IV 5.5 dl / g polyketone polymer (POK) was added to an aqueous solution containing 75 wt% of resorcinol, mixed at 60 ° C. for 2.5 hours, and decompressed to -600 mmHg by thin film evaporation. Bubbles were removed for 30 minutes.

After the bubble in the aqueous solution was completely removed, the resultant was sealed under reduced pressure, and then heated to 80 ° C., thereby obtaining a transparent POK spinning solution through a nozzle. After passing the obtained POK spinning solution through a filter, it extruded at a speed | rate of 20 m / min at 80 degreeC as a trench type extruder through the nozzle (N / Z) of diameter 0.2mm, L / D2.0, and 200hole. After extrusion, the air gap having a length of 10 mm was passed through the air gap, so that solidification occurred in the coagulation bath. As the coagulation bath, a 8.5: 1 mixed solution of methanol and water was used. The ratio represents the weight ratio. After passing through the coagulation bath, the fiber was dried by passing through a hot air dryer at 200 ° C. After that, the polyketone to which an emulsion is given is wound up. In the first stage, the first fiber was heated at 230 ° C., the roller temperature was 190 ° C., the second step was heated at 250 ° C., the roller temperature was 210 ° C., and the third stage was heated at 270 ° C. and the roller temperature was 230 ° C. After stretching to 2 times, 2 times 2 times, and 3 times 1.5 times, the final filament fineness was adjusted to 1,000 denier.

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

[Examples 2 and 3]

As shown in Table 1 below, the defoaming method was carried out in the same manner as in Example 1 while varying the defoaming pressure to prepare a stretched yarn and a treatment cord. The physical properties of the drawn yarn thus obtained are evaluated and shown in Table 1 below.

[Comparative Examples 1 to 3]

A stretched yarn was prepared by performing experiments in a different manner from the above example using a polyketone polymer (POK) having an intrinsic viscosity of 5.5 dl / g. The physical properties of the drawn yarn thus obtained were evaluated and shown in Table 1 below.

* The ratio of methanol and water in Table 1 means the weight ratio.

According to the test results of Table 1, the polyketone fiber prepared at the stretching method and hot air temperature 230/250/270 ° C, roller temperature 190/210/230 ° C according to the present invention (Example 1) The strength of the stretched yarn was higher than that of the stretching method (Comparative Examples 1 and 2) using the hot air heating stretching machine and the stretching method (Examples 2 and 3) drawn at different temperatures.

The method for producing a polyketone fiber according to the present invention has been described in detail using the embodiment. It will be apparent to those skilled in the art that the presented embodiments are merely exemplary, and that modification inventions or modifications can be easily made from the presented embodiments. The scope of the present invention is not limited by the above modified or modified inventions, but only by the following claims.

According to the present invention, a polyketone solution is prepared by dissolving a polyketone containing 90 mol% or more of a ketone unit as a repeating unit in an aqueous solution containing resorcinol, to prepare a homogeneous polyketone solution, and using the roller heating stretching machine Economical and efficient polyketone fibers with good strength can be obtained. The polyketone fibers produced according to the present invention can be produced in industrial fibers, such as tire cords, belts, hoses, ropes and the like having excellent strength by reducing the occurrence of single yarns by stretching only in three stages of stretching in a short heating field.

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

Figure 2 shows a schematic process of a roller heating stretching machine mixed with a hot air heating formula for producing a polyketone filament according to the present invention.

Claims (4)

In the method for producing a polyketone fiber, (A) dissolving a polyketone containing at least 90 mol% ketone units in repeating units in an aqueous solution of resorcinol to prepare a polyketone solution; (B) defoaming the polyketone solution; (C) extruding the degassed polyketone solution through a spinning nozzle, passing through an air layer to reach a coagulation bath, and solidifying it to obtain a multifilament; And (D) washing and drying the emulsion and drying the multifilament in three steps; The content of the polyketone is 5 to 30% by weight relative to the content of the resorcinol, and the drawing process uses a roller heating stretching machine mixed with a hot air heating type, the hot air temperature is 220 ~ 280 ℃, the contact roller Method for producing a polyketone fiber, characterized in that the temperature is made at 180 ~ 240 ℃. The method of claim 1, wherein the diameter of the spinning nozzle is 50 to 200 mm, and the number of orifices of the spinning nozzle is 100 to 2200. The method of claim 1, wherein the stretching comprises at least two elevated temperature steps. A polyketone fiber prepared by the method of claim 1, wherein the polyketone fiber has a strength of 15 to 30 g / d, a fineness of 500 to 3,000 denier, and an elongation of 3 to 10%. .

Images