KR101551418B1 - Process for preparing polyketon fiber - Google Patents

Abstract

The polyketone resin having a high intrinsic viscosity (IV) is not suitable for use because it is entangled (Me) between molecules even though the initial strength is good, and the strength is lowered through the stretching step. Therefore, the present invention is characterized by using a hot-air heating roller dryer and a hot air blower to produce a high-strength fiber through a resin having a high intrinsic viscosity (IV).

Polyketone, hot air heating roller, hot air stretching machine, high IV, stretching

Description

TECHNICAL FIELD [0001] The present invention relates to a process for preparing polyketone fibers,

The polyketone resin having a high intrinsic viscosity (IV) is not suitable for use because it is entangled (Me) between molecules even though the initial strength is good, and the strength is lowered through the stretching step. Accordingly, the present invention provides a method for producing a polyketone fiber characterized by using a hot-air heating roller dryer and a hot air blower to produce high-strength fibers through a resin having a high intrinsic viscosity (IV).

It is a known fact that olefins such as carbon monoxide and ethylene and propylene are polymerized using a transition metal complex such as palladium or nickel as a catalyst to obtain a polyketone in which carbon monoxide and olefin are interchanged. The aliphatic polyketone is a polymer compound containing olefin and carbon monoxide as raw materials such as ethylene and is suitable for general purpose high performance plastics and is excellent in impact resistance and chemical resistance at low temperature and has strength of the same level as para aramid fiber And has good affinity with rubber. Due to the characteristics of polyketone, it is expected that para-aramid fibers can be used exclusively for tire cords and rubber materials.

When a high molecular weight polyketone is melted, heat-crosslinking reaction occurs and melt spinning is inadequate. In general, wet spinning is preferable when polyketone having a high molecular weight is made into a fiber. In wet spinning of polyketones, conventional organic solvents such as hexafluoroisopropanol and m-cresol have problems in toxicity and flammability. Further, the fibers obtained by wet spinning using the above solvent tend to be split, It has disadvantages in that fatigue resistance and workability are insufficient for use.

In addition, when an aqueous solution of a metal salt such as zinc chloride, zinc bromide, lithium bromide, lithium iodide, lithium thiocyanate or the like is used as a solvent, the solubility is low and phase separation occurs, making it difficult to produce a uniform solution.

If the IV of the polymer used in the fiber manufacturing process is lower than about 5 to 7, the stretchability is good, but the stretch ratio (Me) point between molecules is small, so that the desired strength can not be obtained even if the stretch ratio is high. In addition, the higher the initial strength, the higher the initial strength, but the higher the probability of breaking the entangled points through the stretching step, the larger the amount of IV reduction per stretching step than the polyketone resin near IV 5, not.

Polyketone resins of low IV are difficult to achieve high strength properties due to low intermolecular entanglement of the resins themselves, but in case of high IV resins, high strength polyketone fibers can be produced by other suitable methods. Therefore, in order to produce high-strength fibers through the high IV resin, a different method than the conventional method is required. This method uses hot air, a heating roller dryer, and a hot air blower.

The present invention relates to a method for producing a polyketone fiber, comprising the steps of coagulating and washing the polyketone spinning solution extruded from a spinning nozzle, passing the spinning solution through a hot air heating roller dryer, And a manufacturing method thereof.

It is preferable that the magnification of the first stage is 10 or more and the temperature of the hot air dryer is 100 to 260 ° C.

It is preferable that the flow velocity of the washing liquid in the washing step is 3 to 25 m / min.

The polyketone resin of high IV was not suitable for room use because the strength was lowered through the stretching step due to intermolecular entanglement (Me) although the initial strength was good. Therefore, in order to produce a high-strength fiber through a high IV resin, a method other than the conventional method is required. This method uses a hot-air heating roller dryer and a hot air blower. The high IV polyketone requires a lower drying temperature than the low IV polyketone because it can over-densify under high drying conditions and cause property deterioration in the subsequent process, which can save energy cost desirable. In addition, there is an advantage that the stretching step can be reduced by increasing the maximum stretching ratio in the first stage by using the hot air heating roller dryer and the hot air stretching machine.

BRIEF DESCRIPTION OF THE DRAWINGS The invention will be described in detail with reference to the embodiments shown in the accompanying drawings, wherein like reference numerals refer to like elements throughout. However, these should not be construed as excluding the scope of the present invention.

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

1 shows a schematic process of a 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 passes through an air gap in the vertical direction and solidifies in the coagulation bath S2. The air gap is formed so as to obtain radiation within a range of about 1 to 300 mm in order to obtain dense and uniform fibers and to provide a smooth cooling effect.

The filament passing through the coagulation bath passes through the water bath S3. The temperature of the coagulation bath (S2) and the water bath (S3) is adjusted using methanol to prevent rapid desolvation. Also, in order to improve the water washing performance of the water tank, the flow of the washing liquid is made to flow in the opposite direction to the advancing direction of the fiber. The line flow rate of the wash solution was maintained at 3 ~ 25m / min. After the water washing step (S3), a water washing bath (S4) is once again passed through the dryer (S5) to remove residual resorcinol. Then, the emulsifier (S6) is subjected to a process of adding an emulsion and an additive.

Further, an interlace nozzle was passed to improve the flatness and improve the property of the housing. The air pressure for the interlace nozzle was 0.5 to 4.0 kg / cm ² , and the number of entanglement per filament was 2 to 40.

Thereafter, the filament yarn that has passed through the interlace nozzle is dried again using the drying device S7. The drying temperature and the drying method have a great influence on the post-treatment and physical properties of the filament. According to the present invention, the drying temperature is adjusted so that the process water content becomes about 7 to 13%. Finally, the filament passing through the drying device is finally wound up in the winder S8 via the secondary emulsion treatment device.

In the production process of the polyketone fiber of the present invention produced through the above-described production process, the stretching process is very important for improving the high strength and the hot water resistance. The heating method of the drawing process is a hot air heating type and a roller heating type. In the roller heating type, the filament comes into contact with the roller surface and the fiber surface may be damaged. In the hot air type heating method, energy cost is higher than roller heating type, do. Therefore, we tried to overcome the drawbacks by using two methods together. In order to remove moisture to the desired level through roller heating, it has to be raised above 200 ° C, so that it will contact the roller surface and damage the fiber surface. Therefore, the temperature of the roller was set to 100 to 200 ° C and the hot air temperature was set to 200 ° C or more to obtain a moisture content of a desired target value so that the surface of the fiber contacting the heating roller was not damaged

In the present invention, the dry-type smelter S5 is a hot-air heating roller dryer, and the temperature of the roller is 100 ° C or higher, preferably 150 ° C or higher and 200 ° C or lower, and the temperature of hot air is preferably 200 ° C to 260 ° C or lower. Below that, the desired moisture content can not be reached, and above that the physical properties are degraded.

Further, the stretching process in the polyketone fibers of the present invention is very important for improvement of high strength and water resistance. The heating method of the stretching process is a hot-air heating type, and in this case, heating is possible at a temperature of 100 to 260 ° C, preferably 160 to 240 ° C. If the heating temperature is less than 100 ° C, the molecular chain is not sufficiently behaved and high-temperature hot stretching is impossible. If the heating temperature is higher than 260 ° C, the polyketone tends to be decomposed.

For stretching the polyketone fibers, stretching is carried out in one or more stages. In the case of multi-stage stretching, it is preferable to perform the temperature-raising stretching in which the stretching temperature gradually increases with an increase in the stretching magnification. For example, the first stage is 180 to 200 ° C, the second stage is 200 to 230 ° C, and the third stage is 230 to 250 ° C. The draw ratio of the present invention is 5 to 40 times, preferably 10 to 30 times, the total draw ratio.

The multifilament produced by the method according to the present invention is a polyketone multifilament with a total denier range of 500 to 3,500 and a breaking load of 6.0 to 40.0 kg. The multifilament is composed of 100 to 2,200 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%, and dry heat shrinkage is 0.5 to 3%, which can be advantageously used as a tire cord for a passenger car.

Hereinafter, the constitution and effects of the present invention will be described in more detail with specific examples and comparative examples, but the examples are not intended to limit the scope of the present invention. Properties of the tire cord and the like in Examples and Comparative Examples were evaluated by the following methods.

(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 Uvěrod viscometer at a temperature of 25 ± 0.01 ° C and a concentration range of 0.1 to 0.6 g / dl . The intrinsic viscosity is obtained by extrapolating the non-viscosity according to the concentration.

(b) Strength (kgf)

After drying at 107 ° C for 2 hours, a twist of 80 Tpm (twist / m) was applied using a low speed tensile tester manufactured by INSTRONG Co., and the sample was stretched at a rate of 250 mm and a tensile speed of 300 m / min.

[Example 1]

7.0 wt% of IV 10.0 dl / g polyketone polymer (POK) was added to an aqueous solution containing 75 wt% of resorcinol, and the bubbles were removed by reducing pressure at 60 ° C to 100 torr for 30 minutes.

After the bubbles in the aqueous solution were completely removed, the mixture was sealed under reduced pressure, then heated to 80 ° C and stirred for 3 hours to obtain a transparent POK solution. The obtained POK spinning solution was passed through a filter and extruded through a nozzle (N / Z) having a diameter of 0.2 mm, L / D 2.0 and 200 holes at a rate of 20 m / min at 80 ° C as a tentering extruder . After the extrusion, air was passed through the air gap having a length of 10 mm to solidify in the coagulating bath. The fiber passed through the coagulation bath was rinsed with a water bath, and then dried by passing through a heating roller of 130 ° C and a hot air heating roller dryer of 200 ° C. The obtained fibers were subjected to a single-stage drawing at a temperature of 230 ° C in a hot-air blow type stretching machine, and the final filament fineness was adjusted to 1,000 denier.

The fabricated filament drawn yarn was evaluated for its physical properties using a low-speed elongation type tensile tester manufactured by INSTRONG.

[Examples 2 and 3]

An experiment was conducted in the same manner as in Example 1 while changing the temperature of the hot air heating roller as shown in Table 1 below to prepare an undrawn fiber and a drawn fiber.

[Comparative Examples 1 and 2]

The same procedure as in Example 1 was repeated to change the fiber length as shown in Table 1 to prepare a drawn fiber. The properties of the thus-prepared stretched yarn were evaluated and are shown in Table 1 below.

Example 1 Example 2 Example 3 Comparative Example 1 Comparative Example 2 Polyketone
Intrinsic viscosity
(Dl / g)
10
10
10
3.6
5.3 Drying temperature (캜) 130 150 160 220 220 Drying conditions Hot air heating roller Hot air heating roller Hot air heating roller Hot wind line Hot wind line Stretching condition Hot wind type Hot wind type Hot wind type Hot wind type Hot wind type 1st stage
Strength (g / d) 13 11 9 6 8 1st stage
Maximum stretching
ratio 13 12 10 7 7

In general, polyketone resins with high intrinsic viscosity (IV) show high drawability even at high intrinsic viscosity (IV) when using a hot-air heating roller dryer, despite the decrease in elongation due to increased entanglement between molecular chains Respectively. Table 1 shows that the maximum draw ratio is lower than when using a hot-air heating roller dryer, even though it has a lower intrinsic viscosity (IV) when it is dried by the hot air line method.

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

Claims (3)

A method for producing a polyketone fiber, Wherein the polyketone spinning liquid extruded from the spinning nozzle is solidified and washed with water, passed through a hot air heating roller dryer, and then drawn in a hot air drier. The method according to claim 1, Wherein the stretching in the hot air dryer has a draw ratio of 10 or more and the temperature of the hot air dryer is 100 to 260 ° C. The method according to claim 1, Wherein the flow velocity of the washing liquid in the washing step is 3 to 25 m / min.

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