KR100949602B1 - Process for producing Polyketone Fibers - Google Patents

Abstract

The present invention relates to a process for producing high strength polyketone fibers and to polyketone fibers produced by the method. The preparation method according to the present invention comprises the steps of (A) preparing a polyketone solution by containing at least 90 mol% of ketone units in repeating units in an aqueous solution of resorcinol and dissolving high IV polyketone; And (B) allowing the polyketone solution to reach a coagulation bath through thin film evaporation degassing and solidifying the polyketone solution to obtain the most effective physical properties of the multifilament; And (C) washing and drying the multifilament by washing, drying, and emulsion treatment, wherein the defoaming time is greatly reduced through the thin film degassing apparatus in the defoaming step, thereby preventing deterioration of the polyketone solution. . The present invention is suitable for use in industrial fiber fields such as tire cords, belts, hoses, ropes and the like having excellent strength by preventing the breakage of a single filament by preventing deterioration of polyketone fibers through a short time defoaming method.

Polyketone Fiber, Resorcinol, Thin Film Evaporation, Thin Film Evaporation, Water, Methanol, Wet Spinning, Coagulation Bath, Emulsion

Description

Process for producing 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.

When the high molecular weight polyketone is melted, thermal crosslinking reactions occur, so that melt spinning is inadequate. In general, wet spinning is preferable when the high molecular weight polyketone is fibrous. 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 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 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 90 mol% or more of ketone units in a repeating unit in an aqueous solution containing resorcinol, and from the polyketone solution, adhesion between single filaments is prevented. It is to provide a polyketone fiber excellent in strength and a polyketone fiber produced by the method.

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) defoaming the polyketone solution by thin film deposition degassing; (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 multifilament by washing, drying and emulsion treatment, wherein the content of polyketone is 5 to 30% by weight relative to the content of resorcinol, and the defoaming is a thin film deposition defoaming method. To provide a method for producing a polyketone fiber, characterized in that made under -650mmHg to -600mmHg pressure.

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%.

The polyketone fibers prepared according to the present invention can produce industrial fibers such as tire cords, belts, hoses, ropes, and the like having excellent strength by reducing deterioration by degassing at high temperatures for a short time.

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 7 to 13%.

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. In the case of using the hot air heating type, heating is possible at a temperature of 140 to 270 ° C, but preferably 160 to 260 ° C. If the heating temperature is below 140 ° C, the molecular chain is not sufficiently behaved, so high magnification thermal stretching is impossible, and above 270 ° C, polyketone is easily decomposed, resulting in deterioration of physical properties.

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 and fatigue resistance of the polyketone fiber is not sufficient, and if the intrinsic viscosity is more than 20 dl / g, it will not only be economically time-consuming and expensive, but also uniformly dissolved. 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 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 35 to 95% by weight, but preferably 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 thin film deposition apparatus maintained at high pressure, and the dope solution flows down the stirrer in close contact with the wall to form a thin film on the surface of the apparatus. 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. 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 proper 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.

In order to obtain polyketone fibers having high strength and excellent fatigue resistance and dimensional stability as key technical matters in the present invention, a short time defoaming technique is an important factor. For example, it is difficult to obtain high-strength industrial fibers due to the occurrence of tearing or trimming due to the generation of deterioration products such as aldol and furan in the rope solution during long-term defoaming. Therefore, in the present invention, using a thin film evaporation method, the defoaming time is to be within 1 to 2 hours. More preferably, defoaming is facilitated within 20 to 50 minutes to minimize denaturation of the Dope solution.

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 addition, the stretching process 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 less than 140 ℃ high molecular stretching is not possible because the molecular chain does not behave sufficiently, and above 260 ℃ polyketone is easy to decompose physical properties are degraded.

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 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 3,500 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 30 g / d, elongation is 3 to 10%, shrinkage of 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 in a 0.5M hexafluoroisopropanol solution made according to ASTM D539-51T using a Uberod viscometer at a temperature of 25 W 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 the filament yarn into 1m units and cut only 0.1m of them to make five samples, and then dry them at about 107 ℃ for 2 hours under no load, and then check the filament with naked eyes 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 drying for 24 hours at 25 ° C. and 65% RH, dry heat shrinkage was determined using the ratio of the length (L ₀ ) measured at 20 g of the initial load and the length (L ₁ ) after treatment at the static load of 20 g at 30 ° C. for 30 minutes. Indicates.

S (%) = (L ₀ -L ₁ ) / L ₀ × 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

13.0 wt% of IV 5.0 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. After the obtained fiber was subjected to three-stage stretching while gradually raising the temperature at 220 ° C, 230 ° C, and 240 ° C, 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 using a polyketone polymer (POK) having an intrinsic viscosity of 5.0 dl / g in a different manner from the above examples. The physical properties of the drawn yarn thus obtained were evaluated and shown in Table 1 below.

TABLE 1

Example 1 Example 2 Example 3 Comparative Example 1 Comparative Example 2 Comparative Example 3 Resorcinol / H ₂ O = 3: 1 Resorcinol / H ₂ O = 3: 1 Resorcinol / H ₂ O = 3: 1 Resorcinol / H ₂ O = 3: 1 Resorcinol / H ₂ O = 3: 1 Resorcinol / H ₂ O = 3: 1 The furtherance costs of coagulation bath Methanol: Water 8.5: 1.5 Methanol: Water 8.5: 1.5 Methanol: Water 8.5: 1.5 Methanol: Water 8.5: 1.5 Methanol: Water 8.5: 1.5 Methanol: Water 8.5: 1.5 Polyketone Intrinsic Viscosity (㎗ / g) 5.0 5.0 5.0 5.0 5.0 5.0 Content ratio (wt%) 13 13 13 13 13 13 Melting Process Tank 60 ^o C / 2.5 hours 60 ^o C / 2.5 hours 60 ^o C / 2.5 hours 60 ^o C / 2.5 hours 60 ^o C / 2.5 hours 60 ^o C / 2.5 hours Discharge Process Tank 80 ^o C / 15 minutes 80 ^o C / 15 minutes 80 ^o C / 15 minutes 80 ^o C / 15 minutes 80 ^o C / 15 minutes 80 ^o C / 15 minutes Defoaming method T.F.E T.F.E T.F.E Normal vacuum defoaming T.F.E T.F.E Defoaming pressure -600mmHg -580mmHg -650mmHg -600mmHg -400mmHg -750mmHg Defoaming time 30 minutes 30 minutes 30 minutes 3 hours 30 minutes 30 minutes Extrusion Temperature (℃) 80 80 80 80 80 80 Emulsion Mixing Ratio 3: 7 3: 7 3: 7 3: 7 3: 7 3: 7 Fineness (denier) 1000 1000 1000 1000 1000 1000 Strength (g / d) 18 17.6 17.4 15.3 16.5 16.1 Elongation (%) 3.9 4.1 4.5 4.3 4.2 4.2 Dry Heat Shrinkage (%) 1.3 1.5 1.2 1.3 1.1 1.1

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

According to the test results of Table 1, the defoaming method using a thin film evaporation according to the present invention and the polyketone fibers (Example 1) prepared under -600mmHg reduced pressure is a general vacuum degassing method (Comparative Example 1) Compared with other defoaming pressures (Comparative Examples 2 and 3), the strength of the drawn yarn was excellent.

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 modification or modification invention, but only by the following claims.

According to the present invention, a homogeneous polyketone solution is prepared by dissolving a polyketone containing 90 mol% or more of a ketone unit in a repeating unit in an aqueous solution containing resorcinol, and depositing the polyketone solution on a thin film (Thin Film Evaporation). After defoaming for a short time using), the dope solution can be passed through a coagulation bath to obtain a polyketone fiber having excellent strength. The polyketone fibers prepared according to the present invention can produce industrial fibers such as tire cords, belts, hoses, ropes, and the like having excellent strength by reducing deterioration by degassing at high temperatures for a short time.

1 is a schematic diagram of a spinning process for producing polyketone filaments 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 stretching the multifilament by washing, drying and emulsion treatment, Wherein the content of the polyketone is 5 to 30% by weight relative to the content of the resorcinol, and the defoaming method of producing a polyketone fiber, characterized in that made in a thin film deposition degassing method under -650mmHg to -600mmHg pressure. 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. delete

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