A method for producing a continuous polyarylate nascent filament by polymerization spinning and a polyarylate nascent filament

Abstract

The application provides a preparation method of continuous polymerization spinning polyarylate primary filaments and polyarylate primary filaments, and belongs to the field of high-performance fibers. In the preparation method, atomization pre-polymerization and arc plate reinforced devolatilization are adopted, so that the pre-polymerization speed is accelerated, the molecular weight of the polyarylate prepolymer is increased, and the uniformity of the polyarylate prepolymer is improved. Then, the polyarylate primary filaments are obtained through double-screw extrusion tackification and melt direct spinning. The whole process is sealed from oxygen, and the side reactions such as oxidation, branching and crosslinking are maximally inhibited, so that the stabilization of the polyarylate primary filaments is realized, the polyarylate primary filaments with high uniformity and low color are obtained, and a solid foundation is provided for the preparation of high-performance and high-quality polyarylate fibers.

Description

Technical Field

[0001] This invention relates to the field of high-performance polymer preparation technology, and in particular to a method for preparing polyarylate nascent filaments by continuous polymerization spinning and the polyarylate nascent filaments themselves. Background Technology

[0002] Polyarylates are a class of thermotropic liquid crystal polymers that emerged in the mid-1970s following lyotropic liquid crystal polyamides (poly(p-phenylene terephthalamide), a polymer of aramid 1414). When polyarylate chips are dried and then melted, the melt exhibits an anisotropic liquid crystal state. Therefore, as the polyarylate melt flows through the spinneret, the main chain undergoes a high degree of uniaxial orientation due to shear force. Because of the high rigidity of the polyarylate structure, this high degree of uniaxial orientation is not relaxed after leaving the spinneret and is thus well maintained. Under the stretching action of the spinneret, the orientation further develops, and the resulting polyarylate nascent filaments do not require post-stretching to improve their orientation. After heat treatment, the macromolecular ends in the polyarylate fiber further condense, and the crystallinity is further improved, greatly increasing the tensile strength of the polyarylate fiber, thus producing high-strength, high-modulus polyarylate fibers. This high-strength, high-modulus polyarylester fiber can be used in aerospace fields such as satellites, aircraft, and airships. It can also be used for reinforcement in optical fibers, communication cables, and sporting goods. Furthermore, it can be used as bulletproof materials, protective composite panels, safety helmets, and high-temperature resistant, high-strength protective gloves. In addition, it can be used as a high-temperature resistant, acid- and alkali-resistant filter material. In recent years, due to its low dielectric constant and dielectric loss, polyarylester fiber has also been widely used in 5G materials.

[0003] However, existing technologies for preparing polyarylate raw materials all employ intermittent polymerization. The polymerized melt is cooled, granulated, and then dried, melted, and spun. For example, Chinese patent application number 201910803586.8 discloses that the liquid crystal fiber protected by claim 9 is obtained by pre-curing the liquid crystal oligomer, followed by melt spinning. In short, existing technologies require granulation and drying of the polyarylate melt before spinning to obtain nascent polyarylate filaments or fibers. This approach has the following unavoidable drawbacks: 1. Intermittent polymerization leads to unstable polyarylate quality; 2. The segmented conversion process is lengthy, with prolonged polymerization time, and the high-temperature polymerization process easily generates side reactions, resulting in a high b-value in the product; 3. During the process of cooling, granulating, drying, and remelting the melt, polymer degradation is likely to occur, reducing fiber quality and increasing energy consumption. Summary of the Invention

[0004] To address the aforementioned problems, this invention provides a method for preparing polyaryl virgin filaments by continuous polymerization spinning, as well as the polyaryl virgin filaments themselves. This method overcomes the issues of unstable polyaryl filament quality, lengthy and time-consuming polymerization routes, and high energy consumption caused by the existing technical routes. As a result, polyaryl virgin filaments with high stability and good uniformity are obtained, providing a solid foundation for the quality stability of polyaryl fibers obtained by heat treatment of the virgin filaments.

[0005] To achieve the above objectives, the technical solution adopted by the present invention is as follows:

[0006] A method for preparing continuously polymerized and spun polyarylate nascent filaments, comprising the following steps:

[0007] (1) Acetylation:

[0008] A phenolic hydroxyl monomer, acetic anhydride, and catalyst are continuously added to a reactor, and an acetylation reaction is carried out under inert gas protection at 120–185 °C for 30–240 min. After the acetylation reaction, an acetylated monomer is obtained.

[0009] The molar ratio of the phenolic hydroxyl monomer to acetic anhydride is 3:1 to 1:1.

[0010] (2) Atomized prepolymerization:

[0011] With or without adding aromatic dicarboxylic acid monomers, the acetylated monomers obtained in step (1) are continuously fed into a horizontal atomizing reactor. Under inert gas protection and pressure of 0.12–0.36 MPa, the mixture is sprayed and atomized to remove acetic acid, thus obtaining a polyarylate prepolymer. The temperature inside the horizontal atomizing reactor is controlled at 170°C–320°C, and the residence time is controlled at 30–300 min.

[0012] The horizontal atomizing reactor has a spray atomization function and includes an arc-shaped plate;

[0013] (3) Twin-screw final polymerization extrusion:

[0014] The polyaryl ester prepolymer obtained in step (2) is continuously fed into a twin-screw extruder with an aspect ratio of 30:1 to 75:1 for thickening to obtain a high-viscosity polyaryl ester melt; the reaction temperature in the twin-screw extruder is 255 to 355°C, the residence time of the polyaryl ester melt in the twin screw is 25 to 45 minutes, and the die pressure of the twin-screw extruder is 6 to 10 MPa;

[0015] (4) Melt spinning:

[0016] The polyaryl ester melt obtained in step (3) is melt-spun through a spinning box, a metering pump and a spinneret, and then wound to obtain polyaryl ester filaments; wherein the polyaryl ester is extruded through the spinneret holes and then subjected to ring cooling and solidification, with a ring cooling height of 100-380 mm and a cooling temperature of 120-315 °C.

[0017] The above-mentioned method for preparing polyarylate nascent filaments by continuous polymerization spinning, wherein the catalyst in step (1) is one or more of the carboxylates or complexes of sodium, potassium, zinc, calcium, magnesium, titanium, tin and antimony.

[0018] The above-mentioned method for preparing polyarylate nascent filaments by continuous polymerization spinning, wherein the horizontal atomizing reactor in step (2) is divided into 4 to 6 temperature-controlled sections.

[0019] The above-mentioned method for preparing polyarylate nascent filaments by continuous polymerization spinning includes a distillation device at the middle and rear ends of the horizontal atomizing reactor described in step (2) to remove a large amount of acetic acid generated in the reaction.

[0020] The above-mentioned method for preparing polyarylate nascent filaments by continuous polymerization spinning, wherein in step (2), the angle of advancement of the arc plate along the axial center is 35-85°, the spacing of the arc plates is 35-120mm, the axial advancement speed of the arc plate is 5-25r / min, and the melt thickness on the arc plate is 0.8-4.2mm;

[0021] In the above-mentioned method for preparing polyarylate nascent filaments by continuous polymerization spinning, in step (3), the twin-screw extruder is provided with 8 to 12 temperature control zones, and the middle and rear part of the twin-screw extruder is also provided with at least 2 devouring ports.

[0022] In the above-mentioned method for preparing polyarylate nascent filaments by continuous polymerization spinning, the winding speed in step (4) is 500-1500 m / min.

[0023] A method for preparing polyarylate nascent filaments using the method described above, wherein the total fineness of the polyarylate nascent filaments is 10 to 3600 dtex and the CV value is not greater than 10%.

[0024] The aforementioned polyaryl virgin filaments, wherein the b-value of the polyaryl virgin filaments is not greater than 8.

[0025] The aforementioned polyaryl virgin filament has a breaking strength of 3–11 cN / dtex.

[0026] The above technical solution has the following advantages or beneficial effects:

[0027] The present invention provides a method for preparing polyarylate nascent filaments through continuous polymerization and spinning. This method utilizes an in-steam acetylation reaction in a monomer reactor, atomization spraying in a horizontal atomizing reactor, and the use of an arc-shaped plate for homogenization prepolymerization. This increases the specific surface area of ​​the polymer, accelerates devolatilization, improves the polymerization rate, and shortens the reaction time, resulting in a highly uniform polyarylate prepolymer. Subsequently, a twin-screw final polymerization process is employed, rapidly increasing viscosity and stabilizing the pressure before directly spinning the polyarylate nascent filaments. The entire process is a closed, non-oxidizing, continuous production, avoiding oxidation during intermittent polymerization. The use of a horizontal atomizing reactor for prepolymerization and a twin-screw reactor for final polymerization not only improves the reaction rate and lowers the reaction temperature but also avoids the rod-climbing effect caused by vertical reactors, reducing side reactions. This, in turn, facilitates the stable and uniform spinning of the nascent filaments, enabling the production of highly stable and uniform polyarylate nascent filaments, providing a solid foundation for the stable quality of polyarylate fibers obtained after heat treatment of the nascent filaments.

[0028] Compared with existing segmented polymer preparation and spun nascent filament technologies, this invention features continuous production, compact equipment, small footprint, and significantly reduced input and operating costs. Attached Figure Description

[0029] The invention, its features, shape, and advantages will become more apparent from the following detailed description of non-limiting embodiments with reference to the accompanying drawings. Like reference numerals denote like parts throughout the drawings. The drawings are not intentionally drawn to scale; the focus is on illustrating the spirit of the invention.

[0030] Figure 1 This is a cross-sectional view of the overall structure of the horizontal atomizing reactor provided in Embodiment 5 of the present invention. Detailed Implementation

[0031] The present invention will be further described below with reference to specific embodiments, but these are not intended to limit the invention.

[0032] Example 1: This invention provides a method for preparing continuously polymerized and spun polyarylate nascent filaments, comprising the following steps:

[0033] (1) Acetylation:

[0034] 75 wt% p-hydroxybenzoic acid (HBA), 25 wt% 2-hydroxy-6-naphthoic acid (HNA), 76% acetic anhydride (Ac2O) of the total monomers, and 0.5% zinc acetate catalyst of the total monomers were continuously added to a bottom-in, top-out reactor at a certain flow rate. The acetylation reaction was carried out in an inert gas stream at a reaction temperature of 155 °C and a residence time of 100 min.

[0035] (2) Atomized prepolymerization:

[0036] The acetylated monomer obtained in step (1) was fed into a horizontal atomizing reactor at a certain flow rate. After atomization and deacetic acid removal under a pressure of 0.24 MPa, a polyarylate prepolymer was obtained. The arc-shaped plates advanced at a 60° axial angle, with a spacing of 75 mm, an axial rotation speed of 15 r / min, and a melt thickness of 2.6 mm on the arc-shaped plates. The entire atomizing reactor was divided into five temperature-controlled sections, with temperatures set at 180, 220, 250, 270, and 280 °C, and a residence time of 120 min. The horizontal atomizing reactor was protected under an inert gas atmosphere.

[0037] (3) Reactive twin-screw final polymerization and pressure-stabilized conveying:

[0038] The polyaryl ester prepolymer was continuously fed into a twin-screw extruder with a length-to-diameter ratio of 65:1 for viscosity enhancement to obtain polyaryl ester melt. The twin-screw extruder was equipped with 10 temperature control zones, with temperatures set at 275, 280, 285, 290, 295, 300, 305, 310, 315, and 310°C, respectively. Two devolatilization ports were located at the rear of the twin-screw extruder, and a vacuum was applied with a controlled pressure of 3 kPa. The residence time of the polyaryl ester melt in the twin-screw extruder was approximately 32 minutes, and the die head pressure was 8.5 MPa.

[0039] (4) Metering of spinning box and slow cooling and forming of filaments under spinneret

[0040] The polyarylate melt is metered by a metering pump inside the spinning box, and after being distributed and filtered, it is spun and slowly cooled and solidified under the spinneret; the ring cooling height is 250mm, and the atmosphere temperature in the cooling zone is 260℃.

[0041] (5) New silk curls

[0042] The cured polyaryl virgin filaments were oiled and wound to obtain polyaryl virgin filaments at a winding speed of 1500 m / min.

[0043] Example 2:

[0044] Embodiment 2 of the present invention provides a method for preparing continuous polymer-spun polyarylate nascent filaments, comprising the following steps:

[0045] (1) Acetylation:

[0046] 54 wt% p-hydroxybenzoic acid (HBA), 24 wt% 4,4'-dihydroxybiphenyl (BP), 151% acetic anhydride (Ac2O) of total monomers, and 0.8% sodium acetate catalyst of total monomers were continuously added to a bottom-in, top-out reactor at a certain flow rate. The acylation reaction was carried out under an inert gas flow at a reaction temperature of 185°C and a residence time of 240 min.

[0047] (2) Atomized prepolymerization:

[0048] The acetylated monomer obtained in step (1) was mixed with 16 wt% terephthalic acid (TPA) and 6 wt% isophthalic acid (IPA) and fed into a horizontal atomizing reactor at a certain flow rate. After atomization and deacetic acid removal under a pressure of 0.36 MPa, a polyarylate prepolymer was obtained. The arc-shaped plates advanced at an axial center angle of 85°, with a spacing of 80 mm, an axial advancement speed of 23 r / min, and a melt thickness of 1.2 mm on the arc-shaped plates. The entire atomizing reactor was divided into six temperature-controlled sections, with temperatures set at 190, 240, 260, 280, 300, and 310 °C, and a residence time of 270 min. The horizontal atomizing reactor was protected under an inert gas atmosphere.

[0049] (3) Reactive twin-screw final polymerization and pressure-stabilized conveying:

[0050] The polyarylate prepolymer is continuously fed into a twin-screw extruder with a length-to-diameter ratio of 75:1 at a controlled flow rate. The twin-screw extruder is equipped with 12 temperature control zones, with set temperatures of 305, 315, 320, 325, 335, 340, 345, 345, 350, 350, 355, and 350°C, respectively. Three devolatilization ports are located in the middle and rear of the twin-screw extruder, and a vacuum is evacuated with a controlled pressure of 8 kPa. The residence time of the melt in the twin-screw extruder is approximately 43 minutes, and the die head pressure is 9.8 MPa.

[0051] (4) Metering of spinning box and slow cooling and forming of filaments under spinneret

[0052] The polyarylate melt is metered by a metering pump inside the spinning box. After melt distribution and filtration, it undergoes slow cooling and solidification under the spinneret. The slow cooling ring height is 350 mm, and the atmosphere temperature in the slow cooling zone is 315℃.

[0053] (5) New silk curls

[0054] The cured polyarylate nascent filaments were oiled and wound at a speed of 950 m / min.

[0055] Example 3:

[0056] Embodiment 3 of the present invention provides a method for preparing continuous polymer spinning of polyarylate nascent filaments, comprising the following steps:

[0057] (1) Acetylation:

[0058] 62 wt% p-hydroxybenzoic acid (HBA), 22 wt% bisphenol A (AP), 181% acetic anhydride (Ac2O) of total monomers, and 0.1% sodium benzoate / zinc acetate catalyst of total monomers were continuously added to a bottom-in, top-out reactor at a certain flow rate. The acylation reaction was carried out in an inert gas stream at a reaction temperature of 130°C and a residence time of 30 min.

[0059] (2) Atomized prepolymerization:

[0060] The acetylated monomer obtained in step (1) was mixed with 16 wt% terephthalic acid (TPA) and fed into a horizontal atomizing reactor at a certain flow rate. After atomization and deacetic acid removal under a pressure of 0.12 MPa, a polyarylate prepolymer was obtained. The arc-shaped plates advanced at a 35° axial angle, with a spacing of 120 mm, an axial rotation speed of 25 r / min, and a melt thickness of 4.0 mm on the arc-shaped plates. The entire atomizing reactor was divided into four temperature-controlled sections, with temperatures set at 170, 210, 250, and 290 °C, and a residence time of 40 min. The horizontal atomizing reactor was protected under an inert gas atmosphere.

[0061] (3) Reactive twin-screw final polymerization and pressure-stabilized conveying:

[0062] The polyarylate prepolymer is continuously fed into a twin-screw extruder with a length-to-diameter ratio of 50:1 at a controlled flow rate. The twin-screw extruder is equipped with eight temperature control zones, with temperatures set at 285, 290, 295, 300, 305, 310, 315, and 310°C, respectively. Two devolatilization ports are located at the rear of the twin-screw extruder, and a vacuum is applied with a controlled pressure of 6 kPa. The residence time of the melt in the twin-screw extruder is approximately 35 minutes, and the die head pressure is 6 MPa.

[0063] (4) Metering of spinning box and slow cooling and forming of filaments under spinneret

[0064] The polyarylate melt is metered by a metering pump inside the spinning box. After melt distribution and filtration, it undergoes slow cooling and solidification under the spinneret. The slow cooling ring height is 100 mm, and the atmosphere temperature in the slow cooling zone is 200℃.

[0065] (5) New silk curls

[0066] The cured polyarylate nascent filaments were oiled and wound at a speed of 600 m / min.

[0067] Example 4:

[0068] Embodiment 4 of the present invention provides a method for preparing continuous polymer-spun polyarylate nascent filaments, comprising the following steps:

[0069] (1) Acetylation:

[0070] 69 wt% p-hydroxybenzoic acid (HBA), 20 wt% hexafluorobisphenol A (AF), 88% of the total monomers of acetic anhydride (Ac2O), and 0.9% of the total monomers of catalyst sodium benzoate / magnesium acetate were continuously added to a bottom-in, top-out reactor at a certain flow rate. The acylation reaction was carried out in an inert gas stream at a reaction temperature of 120 °C and a residence time of 220 min.

[0071] (2) Atomized prepolymerization:

[0072] The acetylated monomer obtained in step (1) was mixed with 10 wt% terephthalic acid (TPA) and fed into a horizontal atomizing reactor at a certain flow rate. After atomization and deacetic acid removal under a pressure of 0.16 MPa, a polyarylate prepolymer was obtained. The arc-shaped plates advanced at a 45° axial angle, with a spacing of 50 mm, an axial rotation speed of 8 r / min, and a melt thickness of 3.6 mm on the arc-shaped plates. The entire atomizing reactor was divided into five temperature-controlled sections, with temperatures set at 170, 200, 235, 275, and 290 °C, and a residence time of 180 min. The horizontal atomizing reactor was protected under an inert gas atmosphere.

[0073] (3) Reactive twin-screw final polymerization and pressure-stabilized conveying:

[0074] The polyarylate prepolymer is continuously fed into a twin-screw extruder with a length-to-diameter ratio of 55:1 at a controlled flow rate. The twin-screw extruder is equipped with 10 temperature control zones, with temperatures set at 255, 275, 290, 295, 295, 300, 305, and 305°C, respectively. Two devolatilization ports are located at the rear of the twin-screw extruder, and a vacuum is applied with a controlled pressure of 16 kPa. The residence time of the melt in the twin-screw extruder is approximately 45 minutes, and the die head pressure is 7.5 MPa.

[0075] (4) Metering of spinning box and slow cooling and forming of filaments under spinneret

[0076] The polyarylate melt is metered by a metering pump inside the spinning box. After melt distribution and filtration, it undergoes slow cooling and solidification under the spinneret. The slow cooling ring height is 150 mm, and the atmosphere temperature in the slow cooling zone is 220℃.

[0077] (5) New silk curls

[0078] The cured polyaryl nascent filaments were oiled and wound at a speed of 500 m / min.

[0079] Example 5:

[0080] Embodiment 5 of the present invention provides a method for preparing continuously polymerized and spun polyarylate nascent filaments, comprising the following steps:

[0081] (1) Acetylation:

[0082] 60 wt% p-hydroxybenzoic acid (HBA), 16 wt% hydroquinone (HQ), 122% acetic anhydride (Ac2O) of the total monomers, and 0.3% tin acetate catalyst of the total monomers were continuously added to a bottom-in, top-out reactor at a certain flow rate. The acylation reaction was carried out under an inert gas flow at a reaction temperature of 180 °C and a residence time of 160 min.

[0083] (2) Atomized prepolymerization:

[0084] The acetylated monomer obtained in step (1) was mixed with 12 wt% terephthalic acid (TPA) and 12 wt% isophthalic acid (IPA) and fed into a horizontal atomizing reactor at a certain flow rate. After atomization and deacetic acid removal under a pressure of 0.30 MPa, a polyarylate prepolymer was obtained. The arc-shaped plates advanced at a 55° axial center angle, with a spacing of 35 mm, an axial advancement speed of 5 r / min, and a melt thickness of 0.8 mm on the arc-shaped plates. The entire atomizing reactor was divided into six temperature-controlled sections, with temperatures set at 185, 235, 255, 285, 310, and 320 °C, and a residence time of 300 min. The horizontal atomizing reactor was protected under an inert gas atmosphere.

[0085] (3) Reactive twin-screw final polymerization and pressure-stabilized conveying:

[0086] The polyarylate prepolymer is continuously fed into a twin-screw extruder with a length-to-diameter ratio of 35:1 at a controlled flow rate. The twin-screw extruder is equipped with eight temperature control zones, with temperatures set at 300, 310, 320, 330, 330, 340, 350, and 355°C, respectively. Two devolatilization ports are located at the rear of the twin-screw extruder, and a vacuum is applied with a controlled pressure of 1 kPa. The residence time of the melt in the twin-screw extruder is approximately 25 minutes, and the die head pressure is 6.0 MPa.

[0087] (4) Metering of spinning box and slow cooling and forming of filaments under spinneret

[0088] The polyarylate melt is metered by a metering pump inside the spinning box. After melt distribution and filtration, it undergoes slow cooling and solidification under the spinneret. The slow cooling ring height is 380 mm, and the atmosphere temperature in the slow cooling zone is 305 °C.

[0089] (5) New silk curls

[0090] The cured polyarylate nascent filaments were oiled and wound at a speed of 750 m / min.

[0091] Example 6:

[0092] Embodiment 6 of the present invention provides a method for preparing continuously polymerized and spun polyarylate nascent filaments, comprising the following steps:

[0093] (1) Acetylation:

[0094] 55.6 wt% p-hydroxybenzoic acid (HBA), 29.3 wt% 2-hydroxy-6-naphthoic acid (HNA), 10.0 wt% 10-(2,5-dihydroxyphenyl)-10-hydro-9-oxa-10-phosphaphenanthrene-10-oxide (DOPOHQ), 116% acetic anhydride (Ac2O) and 0.4% sodium benzoate / calcium acetate catalyst were continuously added to a bottom-in, top-out reactor at a certain flow rate. The acylation reaction was carried out in an inert gas stream at a reaction temperature of 160 °C and a residence time of 60 min.

[0095] (2) Atomized prepolymerization:

[0096] The acetylated monomer obtained in step (1) was mixed with 5.1 wt% terephthalic acid (TPA) and fed into a horizontal atomizing reactor at a certain flow rate. After atomization and deacetic acid removal under a pressure of 0.28 MPa, a polyarylate prepolymer was obtained. The arc-shaped plates advanced at a 50° axial angle, with a spacing of 60 mm, an axial rotation speed of 18 r / min, and a melt thickness of 3.2 mm on the arc-shaped plates. The entire atomizing reactor was divided into five temperature-controlled sections, with temperatures set at 175, 225, 250, 270, and 285 °C, and a residence time of 210 min. The horizontal atomizing reactor was protected under an inert gas atmosphere.

[0097] (3) Reactive twin-screw final polymerization and pressure-stabilized conveying:

[0098] The polyarylate prepolymer is continuously fed into a twin-screw extruder with a length-to-diameter ratio of 45:1 at a controlled flow rate. The twin-screw extruder is equipped with eight temperature control zones, with set temperatures of 280, 290, 295, 295, 300, 305, 310, and 310°C, respectively. Two devolatilization ports are located at the rear of the twin-screw extruder, and a vacuum is applied with a controlled pressure of 4 kPa. The residence time of the melt in the twin-screw extruder is approximately 30 minutes, and the die head pressure is 7.9 MPa.

[0099] (4) Metering of spinning box and slow cooling and forming of filaments under spinneret

[0100] The polyarylate melt is metered by a metering pump inside the spinning box. After melt distribution and filtration, it undergoes slow cooling and solidification under the spinneret. The slow cooling ring height is 350 mm, and the atmosphere temperature in the slow cooling zone is 120 °C.

[0101] (5) New silk curls

[0102] The cured polyarylate nascent filaments were oiled and wound at a speed of 1150 m / min.

[0103] Example 7:

[0104] A type of polyaryl virgin filament, prepared by the preparation method of Example 1 above, has a fineness of 1680 dtex, a number of fibers of 480f (1680 dtex / 480f), a fineness CV value of 3.6%, a strength of 10.9 cN / dtex, and a b value of 5.

[0105] The polyarylate nascent filament of Example 1, after heat treatment, has applications including high-strength ropes.

[0106] Example 8:

[0107] A type of polyaryl virgin filament was prepared using the preparation method described in Example 2 above. The polyaryl virgin filament has a fineness of 1100 dtex, a number of strands of 360f (1100 dtex / 360f), a fineness CV value of 5.8%, a strength of 4.2 cN / dtex, and a b value of 7.

[0108] The polyaryl virgin filament of Example 2, after heat treatment, is mainly used in special tire cords, etc.

[0109] Example 9:

[0110] A type of polyaryl virgin filament was prepared using the preparation method described in Example 3 above. The polyaryl virgin filament has a fineness of 360 dtex, a number of ends of 210f (360 dtex / 210f), a fineness CV value of 8.3%, a strength of 3.2 cN / dtex, and a b value of 6.

[0111] The polyarylate nascent filament of Example 3, after heat treatment, is mainly used in safety protection materials and airship skins.

[0112] Example 10:

[0113] A type of polyaryl virgin filament was prepared using the preparation method described in Example 4 above. The polyaryl virgin filament has a fineness of 22 dtex, a number of ends of 5f (22 dtex / 5f), a fineness CV value of 4.1%, a strength of 4.8 cN / dtex, and a b value of 5.

[0114] The polyaryl virgin filament of Example 4, after heat treatment, is mainly used in 5G copper clad laminates, reinforcing materials for wires and cables, etc.

[0115] Example 11:

[0116] A type of polyaryl virgin filament was prepared using the preparation method described in Example 5 above. The polyaryl virgin filament has a fineness of 480 dtex, a number of strands of 240f (480 dtex / 240f), a fineness CV value of 4.8%, a strength of 3.7 cN / dtex, and a b value of 7.

[0117] The polyaryl nascent filament of Example 5, after heat treatment, is mainly used as a reinforcing material for optical cables.

[0118] Example 12:

[0119] A type of polyaryl virgin filament was prepared using the preparation method described in Example 6 above. The polyaryl virgin filament has a fineness of 3600 dtex, a number of strands of 800 f (3600 dtex / 800 f), a fineness CV value of 6.2%, a strength of 8.9 cN / dtex, and a b value of 6.

[0120] A polyarylate nascent filament of embodiment 6 is heat-treated and cut into short fibers with a cutting length of 38-102 mm, which is mainly used in high-temperature felt materials.

[0121] Example 13:

[0122] The horizontal atomizing reactors in Examples 1 to 6 above have the following specific structures:

[0123] like Figure 1 As shown, the horizontal atomizing reactor includes a stirring cage 1 and a spraying device 2; the spraying device 2 is fixedly mounted on the stirring cage 1; the stirring cage 1 includes a conveying pipe 11 with a sealed cavity; the two ends of the conveying pipe 11 are respectively provided with an inlet 111 and an outlet 112; the inlet 111 and the outlet 112 are both connected to the inner and outer spaces of the conveying pipe 11; the spraying device 2 is sealed and fixed at the inlet 111; the spraying device 2 includes a plurality of spray pipes 21; the spray pipes 21 extend into the conveying pipe through the inlet 111.

[0124] When the horizontal atomizing reactor provided in Embodiment 5 of the present invention is working, the polyarylate acetylated monomer is placed in the spray device 2. The operation of the spray device 2 causes the polyarylate acetylated monomer to enter the conveying pipe 11 in the form of atomized gas from the feed port 111 of the stirring cage 1. When the stirring cage 1 is working, the polyarylate acetylated monomer atomized gas in the conveying pipe 11 is fully stirred and finally flows out from the discharge port 112 after stirring. Since the conveying pipe that provides the stirring site for the polyarylate acetylated monomer has a closed cavity, the closed cavity can control and create a vacuum and nitrogen pressure environment, so that the polyarylate acetylated monomer can be fully stirred and mixed, better complete the transesterification, and obtain the polyarylate prepolymer.

[0125] To achieve complete mixing of polyarylate acetylated monomers within the conveying pipe 11, in this embodiment, the stirring cage 1 further includes a rotating shaft 12 and an arc-shaped plate 13. The rotating shaft 12 is coaxially arranged with the conveying pipe 11 and is rotatably disposed within the conveying pipe 11. The arc-shaped plate 13 is disposed within the conveying pipe 11 and is spirally fixed to the rotating shaft 12. All blades of the stirring cage 13 are arranged along the axial direction of the rotating shaft 12. When stirring the polyarylate acetylated monomers, the rotating shaft 12 is rotated, thereby driving the arc-shaped plate 13 to rotate. The polyarylate acetylated monomers enter the conveying pipe 11 in the form of mist from the inlet 111 and suspend inside the conveying pipe 11. The continuously rotating arc-shaped plate 13 agitates the airflow inside the conveying pipe 11, causing the suspended mist-like polyarylate acetylated monomers to move violently and collide, thus achieving full contact and completing ester exchange. The arc-shaped plate 13 is spirally fixed to the rotating shaft 12. When the rotating shaft 12 rotates, the airflow inside the conveying pipe 11... The airflow is blown in one direction by the arc plate 13, and the direction is the same as the direction in which the outlet 112 on the conveying pipe 11 is located. The opening of the outlet 112 is vertically downward to facilitate the outflow of fluid (the pressure inside the conveying pipe 11 can be maintained by setting a one-way valve at the outlet 112, and the equipment can produce some polyarylene purified monomer droplets while compressing the polyarylene acetylated monomer gas; or the outlet 112 can be closed during the production process, and then opened after the liquid compression is completed to remove it all at once).

[0126] The polyaryl acetylated monomer is fed into the conveying pipe 11 in the form of mist by the spraying device 2. Since the polyaryl acetylated monomer mist will sink under the action of gravity, in order to ensure that the polyaryl acetylated monomer can fully contact the arc plate 13, in this embodiment, the axis of the rotating shaft 12 is set horizontally; the outlet of the spray pipe 21 is set directly opposite the rotating shaft 12; the spray pipe 21 is set vertically above the rotating shaft 12; the outlets of all spray pipes 21 are arranged along the axial direction of the rotating shaft 12; and the discharge port 112 is set vertically below the rotating shaft 12. The polyaryl acetylated monomer mist is dropped vertically above the rotating shaft 12. The polyaryl acetylated monomer mist will sink under the action of gravity. When the arc plate 13 rotates around the rotating shaft 12, it will come into contact with these sinking polyaryl acetylated monomer mists, thereby better mixing the polyaryl acetylated monomer mists and facilitating the transesterification process. After the operation is completed, the rotating shaft 12 is stopped, and the polyaryl acetylated monomer mist will fall due to gravity and flow out from the discharge port 112 located vertically below the rotating shaft.

[0127] In order to allow the polyarylate acetylated monomer mist to condense into liquid and flow out from the outlet 112 more effectively, in this embodiment, the spacing between the arc plates 13 is different; the spacing between the arc plates 13 is largest near the end of the spray pipe 21 with the inlet 111; the spacing between the arc plates 13 is smallest near the end of the spray pipe 21 with the outlet 112; and the spacing between adjacent arc plates 13 decreases sequentially from the inlet 111 to the outlet 112. As the shaft 12 rotates, the polyarylate acetylated monomer mist is continuously pushed towards the outlet 112, and the space between the two arc-shaped plates 13 continuously shrinks. When the polyarylate acetylated monomer mist moves towards the outlet 112, the amount of polyarylate acetylated monomer mist per unit space increases, making it easier for the polyarylate acetylated monomer mist to condense and form larger droplets. The droplets, subjected to greater gravity, fall more easily and eventually move towards the outlet 112 until they flow out. The continuously shrinking arc-shaped plates 13 allow the polyarylate acetylated monomer mist to be squeezed into larger droplets during the rotation of the shaft 12, ultimately flowing out from the outlet 112 without stopping the rotation of the shaft 12 to allow the mist to settle and drip completely, thus improving the working efficiency of the equipment.

[0128] In order to drive the rotating shaft 12 to rotate, as a preferred embodiment, a motor 3 for driving the rotating shaft is also included; the drive shaft of the motor 3 is coaxially arranged with the rotating shaft 12; the drive shaft of the motor 3 is fixedly connected to the rotating shaft 12. The method of directly driving the rotating shaft 12 to rotate by rotating the drive shaft of the motor 3 has a simple structure, is easy to install and maintain, and the rotation speed of the rotating shaft 12 can be directly controlled by controlling the rotation speed of the motor 3.

[0129] When the rotating shaft 12 inside the conveying pipe 11 operates, it also agitates the internal air. If this air flows out of the outlet 112 along with the final polyarylate acetylated monomer solution, it will cause the solution to spray out of the outlet 112, which is not conducive to collection. To solve this problem, in this embodiment, the conveying pipe 11 is also provided with several vent holes 113 for venting. The vent holes 113 are located vertically above the rotating shaft 12. A one-way valve is provided on the vent holes 113. The gas at the vent holes 113 can only flow from inside the conveying pipe 11 to the outside of the conveying pipe 11. The vent holes 113 can, on the one hand, allow the air inside the conveying pipe 11 to be discharged, and on the other hand, can also draw in the air inside the conveying pipe 11 beforehand through the vent holes 113, changing the vacuum degree inside the conveying pipe 11, so that the reaction can proceed better.

[0130] In summary, the method for preparing polyarylate nascent filaments by continuous polymerization and spinning provided by this invention utilizes a monomer in-reactor acetylation reaction, atomization spraying in a horizontal atomizing reactor, and the use of an arc-shaped plate for homogenization prepolymerization. This increases the specific surface area of ​​the polymer, accelerates devolatilization, improves the polymerization rate, and shortens the reaction time, resulting in a highly uniform polyarylate prepolymer. Subsequently, a twin-screw final polymerization process is employed, rapidly increasing viscosity and stabilizing the pressure before direct spinning of polyarylate nascent filaments. The entire process is a closed, non-oxidizing, continuous production, thus avoiding oxidation during intermittent polymerization. The use of a horizontal atomizing reactor for prepolymerization and a twin-screw reactor for final polymerization not only improves the reaction rate and lowers the reaction temperature but also avoids the rod-climbing effect caused by vertical reactors, reducing side reactions. This, in turn, facilitates the stable and uniform spinning of nascent filaments from the polymer, enabling the acquisition of highly stable and uniform polyarylate nascent filaments, providing a solid foundation for the quality stability of polyarylate fibers obtained after heat treatment of the nascent filaments.

[0131] Compared with existing segmented polymer preparation and spun nascent filament technologies, this invention features continuous production, compact equipment, small footprint, and significantly reduced input and operating costs.

[0132] The preferred embodiments of the present invention have been described above. It should be understood that the present invention is not limited to the specific embodiments described above, and the devices and structures not described in detail should be understood as being implemented in a manner common to the art. Any possible variations and modifications made by those skilled in the art without departing from the technical solution of the present invention, or equivalent embodiments with equivalent changes, do not affect the essential content of the present invention. Therefore, any simple modifications, equivalent changes, and modifications made to the above embodiments based on the technical essence of the present invention without departing from the content of the technical solution of the present invention shall still fall within the scope of protection of the technical solution of the present invention.

Claims

1. A process for the production of continuous polyarylate as-spun filaments by polymerization spinning, characterized in that The method comprises the following steps: (1) acetylation: phenolic hydroxyl-containing monomers, acetic anhydride and a catalyst are continuously added to a reactor, and acetylation is carried out under the protection of inert gas and at 120-185°C for 30-240 min, to obtain acetylated monomers after acetylation; wherein the molar ratio of the phenolic hydroxyl-containing monomers to the acetic anhydride is 3:1-1:1; (2) atomization pre-polymerization: the acetylated monomers obtained in step (1) are added with or without aromatic dicarboxylic acid monomers and continuously fed into a horizontal atomization reactor, atomization and de-acetic acid are carried out under the protection of inert gas and at a pressure of 0.12-0.36 MPa, to obtain polyarylate pre-polymers; the temperature inside the horizontal atomization reactor is controlled at 170-320°C, and the residence time is controlled at 30-300 min; wherein the horizontal atomization reactor has a spray atomization function and comprises an arc plate; (3) double-screw final polymerization extrusion: the polyarylate pre-polymers obtained in step (2) are continuously input into a double-screw extruder with a length-diameter ratio of 30:1-75:1 for tackification, to obtain high-viscosity polyarylate melt; the reaction temperature inside the double-screw extruder is 255-355°C, the residence time of the polyarylate melt in the double-screw is 25-45 min, and the head pressure of the double-screw extruder is 6-10 MPa; (4) melt spinning: the polyarylate melt obtained in step (3) is subjected to melt spinning through a spinning box, a metering pump and a spinneret, to obtain polyarylate nascent yarn; wherein the polyarylate is subjected to ring slow cooling solidification after extrusion through the spinneret, the ring slow cooling height is 100-380 mm, and the slow cooling temperature is 120-315°C; wherein the arc plate in step (2) has an axial center advancing angle of 35-85°, the spacing of the arc plate is 35-120 mm, the axial advancing speed of the arc plate is 5-25 r / min, and the thickness of the melt on the arc plate is 0.8-4.2 mm.

2. The process for producing a continuous polymeric spun polyarylate as-spun filament according to claim 1, wherein The catalyst in step (1) is one or more of carboxylate salts, complexes of sodium, potassium, zinc, calcium, magnesium, titanium, tin and antimony.

3. The method for preparing polyarylate nascent filament by continuous polymerization spinning as described in claim 1, characterized in that, The horizontal atomization reactor in step (2) is divided into 4-6 temperature control sections.

4. The method for preparing polyarylate nascent filament by continuous polymerization spinning as described in claim 1, characterized in that, The horizontal atomization reactor in step (2) is provided with rectification devices at the middle end and the rear end for removing a large amount of acetic acid generated in the reaction.

5. The method for preparing polyarylate nascent filament by continuous polymerization spinning as described in claim 1, characterized in that, In step (3), the double-screw extruder is provided with 8-12 temperature control sections, and at least two devolatilization ports are further arranged at the middle and rear parts of the double-screw extruder.

6. The method for preparing polyarylate nascent filament by continuous polymerization spinning as described in claim 1, characterized in that, The winding speed in step (4) is 500-1500 m / min.

7. A polyarylate as-spun filament produced by the process of any one of claims 1 to 6, characterized by The total fineness of the polyarylate nascent yarn is 10-3600 dtex, and the CV value is not greater than 10%.

8. The polyarylate aspun silk according to claim 7, wherein The b value of the polyarylate nascent yarn is not greater than 8.

9. The polyarylate aspun silk according to claim 7, wherein The breaking strength of the polyarylate nascent yarn is 3-11 cN / dtex.

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