Modified chlorinated polyethylene fiber, radome material containing the same, and preparation method thereof

Abstract

The present invention discloses a modified chlorinated polyethylene fiber, a radome material containing the same, and a preparation method thereof. The modified chlorinated polyethylene fiber comprises a chlorinated polyethylene fiber and a liquid crystal polymer crosslinked on the surface of the chlorinated polyethylene fiber. The radome material comprises polypropylene as a basic component, and a toughening agent, a compatibilizer, an antioxidant, a light stabilizer and other additives as additional components, and also comprises the modified chlorinated polyethylene fiber. The present invention irradiates and modifies the surface of the chlorinated polyethylene fiber to avoid fiber deformation and decomposition during the processing and molding process, and retains excellent reinforcing and toughening effects; the radome material modified by using the modified chlorinated polyethylene fiber, quartz glass fiber and coke has the characteristics of high low-temperature impact performance, V1-level flame retardancy, and a minimum dielectric constant of 2.2, meets the use requirements of 5G radomes, and is applicable to various molding methods such as injection molding, compression molding, winding, and weaving, with high molding efficiency.

Description

Technical Field

[0001] The present invention relates to the technical field of functional materials, and more specifically, to a modified chlorinated polyethylene fiber, a radome material containing the modified chlorinated polyethylene fiber, and a preparation method thereof. Background Art

[0002] With the continuous maturity of 5G technology, base station deployment has been fully launched across the country and even the world. As the protective shell of the 5G base station antenna, the radome usually needs to be installed on a higher signal transmission tower. Under such working conditions, on the one hand, the material needs to be able to withstand extreme climates, such as high temperature, high humidity, strong radiation, and the impact of hail, rain and snow; on the other hand, in order to improve the efficiency of signal transmission, the material also needs to have low dielectric loss. Polypropylene has low density, excellent mechanical properties, low dielectric loss, and low overall cost, making it very suitable as a base material for the production of this type of product. In order to cope with extreme working conditions and further improve the signal transmission efficiency, it is generally necessary to add toughening agents, compatibilizers, light stabilizers, antioxidants, etc. to polypropylene to modify it. However, traditional polypropylene-based radome materials still face challenges in terms of low temperature impact resistance, high dielectric constant, and flame retardancy.

[0003] Invention patent CN111073147A discloses a composite material for 5G antenna cover with long glass fiber reinforced polypropylene and its preparation method. The method adopts the technical solution of glass fiber reinforced polypropylene to obtain higher low-temperature impact performance, but the dielectric constant, flame retardant grade and other performance parameters of the material are not disclosed, making it difficult to evaluate whether its comprehensive performance meets the use requirements of 5G antenna cover. Invention patent CN111421937A discloses a composite material for 5G millimeter wave antenna cover and its preparation method. The method adopts the technical solution of thermoplastic resin skin and thermoplastic foam composite to prepare lightweight, weather-resistant and flame-retardant antenna cover material, but the technical solution uses expensive foamed PC and PPS, and the composite process is complicated. It is difficult to meet the requirements of continuous industrial production in terms of material cost and molding efficiency.

[0004] Chlorinated polyethylene fiber is a common fishing net fiber with low density, high strength, impact resistance, chemical corrosion resistance, flame retardancy, and low dielectric constant. It has certain application potential in the field of modified plastics. However, chlorinated polyethylene fiber has low softening point and decomposition temperature. When blended with other polymer high-temperature melts, it will destroy its fiber morphology and release hydrogen chloride gas. It will not only fail to achieve the purpose of reinforcement and toughening, but also pollute the production and processing site environment. In addition, the modulus of chlorinated polyethylene is relatively low, and compared with traditional reinforcing fillers such as glass fiber and mineral powder, the modulus improvement of the modified material is very limited. At present, there is no existing technology for applying chlorinated polyethylene fiber to reinforce polypropylene plastics. Therefore, developing a modified chlorinated polyethylene fiber and applying it to antenna cover materials is a technical problem that needs to be solved urgently. Summary of the Invention

[0005] Due to the above-mentioned defects in the prior art, the present invention provides a modified chlorinated polyethylene fiber, a radome material containing the same, and a preparation method thereof. The surface of the chlorinated polyethylene fiber is modified by a liquid crystal polymer (LCP), so that the radome material containing the modified chlorinated polyethylene fiber has the characteristics of low density, resistance to low-temperature impact, flame retardancy, and low dielectric constant, and is completely suitable for the production of radomes including 5G radomes.

[0006] To achieve the above object, in the first aspect, the present invention provides a modified chlorinated polyethylene fiber, which includes a chlorinated polyethylene fiber matrix, and is characterized in that: it further includes a liquid crystal polymer crosslinked with the surface of the chlorinated polyethylene fiber matrix; a graft is formed between the ester groups on the molecular chain of the liquid crystal polymer and the chlorine groups on the surface of the chlorinated polyethylene fiber.

[0007] Furthermore, the Vicat softening point of the modified chlorinated polyethylene fiber can reach up to 185°C at most, the thermal decomposition temperature can reach up to 280°C at most, the strength of the fiber monofilament can reach up to 2.4 cN / dtex at most, and the dielectric constant can reach as low as 3.6 at least.

[0008] In the second aspect, the present invention provides a preparation method of a modified chlorinated polyethylene fiber, which is characterized in that surface irradiation crosslinking treatment is carried out on continuous chlorinated polyethylene fibers; the method includes the following steps: first, place the continuous chlorinated polyethylene fibers into a crosslinking treatment reactor, then use an inert gas to introduce the liquid crystal polymer powder into the crosslinking treatment reactor to form a liquid crystal polymer atmosphere, and then turn on the irradiation source for irradiation to obtain the modified chlorinated polyethylene fiber.

[0009] Preferably, the crosslinking treatment method can adopt any one or a combination of at least two of ultraviolet irradiation, γ-ray irradiation, and peroxide induction; preferably, the crosslinking treatment method adopts γ-ray irradiation crosslinking, and the crosslinking degree can be controlled by the irradiation dose; the γ-ray irradiation intensity is 100-500 kGy, preferably 200-400 kGy.

[0010] In the third aspect, the present invention provides a radome material, which includes polypropylene as a basic component and toughening agents, compatibilizers, antioxidants, light stabilizers, and other additives as additional components, and is characterized in that it further includes the above-mentioned modified chlorinated polyethylene fibers.

[0011] The present invention organically combines the advantages and disadvantages of chlorinated polyethylene fiber and LCP, and successfully prepares a radome material with low temperature impact resistance, flame retardancy and low dielectric constant by means of plastic modification. This material has low density, excellent mechanical properties, outstanding low temperature impact performance, low dielectric loss, and has a certain flame retardant effect, and is completely suitable for the production of radomes, especially 5G radomes.

[0012] Furthermore, the radome material further includes quartz glass fiber and coke powder.

[0013] Preferably, based on the sum of the weight percentages of the components of the radome material being 100%, the components include:

[0014]

[0015]

[0016] Among them, other additives include one or more of color powder, color masterbatch or lubricant.

[0017] Furthermore, based on the sum of the weight percentages of the components of the radome material being 100%, the components include:

[0018]

[0019] Preferably, the polypropylene is a composition of one or more of homopolymerization or copolymerization, with a melting temperature of 130-180°C and a melt flow rate of 30-150 g / 10 min, preferably 50-130 g / 10 min, more preferably 60-120 g / 10 min; and / or, the toughening agent is a composition of one or more of ethylene-propylene-diene monomer (EPDM), polyolefin elastomer (POE), hydrogenated styrene-butadiene block copolymer (SEBS), styrene-butadiene-styrene block copolymer (SBS); and / or, the modified chlorinated polyethylene fiber has a molecular weight of 100,000-1,000,000, preferably 200,000-800,000, more preferably 300,000-700,000; and / or, the fiber diameter of the quartz glass fiber is 5-30 microns, preferably 7-27 microns, more preferably 10-18 microns; and / or, the powder diameter of the coke powder is 500-3000 mesh, preferably 800-2500 mesh, more preferably 1000-2000 mesh; and / or, the compatibilizer is selected from one or more of maleic anhydride grafted polypropylene, maleic anhydride grafted polyethylene or maleic anhydride grafted thermoplastic polyolefin elastomer; and / or, the antioxidant includes a main antioxidant and a co-antioxidant, the main antioxidant is selected from one or more of hindered phenol antioxidants, thioesters, and the co-antioxidant is selected from phosphite antioxidants; and / or, the light stabilizer is selected from one or more of hindered amine light stabilizers, benzophenone light stabilizers or benzotriazole light stabilizers.

[0020] In a fourth aspect, the present invention provides a method for preparing the above-mentioned radome material, which is characterized by comprising the following steps:

[0021] Step S1: Mix polypropylene, toughening agent, coke powder, compatibilizer, light stabilizer, antioxidant and other additives according to the proportioning amount, and then add them to a twin-screw extruder for melting and plasticizing;

[0022] Step S2: Immerse, cool, dry, pelletize or wind up the modified chlorinated polyethylene fiber and quartz glass fiber according to the proportioning amount in the mixture obtained by melting and plasticizing in Step S1 to obtain the radome material.

[0023] Preferably, the temperature of the melting and plasticizing is 180-270°C, preferably 190-250°C, more preferably 200-230°C; the length-diameter ratio of the screw of the twin-screw extruder is 20-55, preferably 25-50, more preferably 30-48.

[0024] In a last aspect, the present invention provides a radome, which is characterized by being made of the above-mentioned radome material or the radome material prepared by using the above-mentioned method for preparing the radome material.

[0025] Compared with the prior art, the above-mentioned invention has the following advantages or beneficial effects:

[0026] (1) The chlorinated polyethylene fiber is irradiated and crosslinked in the atmosphere of LCP powder. The ester groups on the LCP molecular chain will undergo a substitution reaction with the chlorine groups on the fiber surface to form a graft, effectively improving the Vicat softening point, thermal decomposition temperature and fiber monofilament strength of the fiber, while the dielectric constant is reduced. Therefore, while maintaining the characteristics of low density, high strength, impact resistance, flame retardancy and low dielectric constant of the chlorinated polyethylene matrix fiber, the modified chlorinated polyethylene fiber further improves the heat resistance and low dielectric characteristics of the fiber, avoiding fiber deformation and decomposition during subsequent processing and forming.

[0027] (2) Modify polypropylene by using a compounding method of modified chlorinated polyethylene fiber and quartz glass fiber, improving the toughness and rigidity of the material while endowing the material with a lower density; modifying polypropylene with chlorinated polyethylene and quartz glass fiber endows the material with extremely low dielectric loss; there are a large number of micropores inside the coke powder, and its dielectric constant is much lower than that of other filling materials. Adding it to the plastic can effectively improve its dielectric performance, and at the same time has a certain effect of enhancing and stabilizing the size;

[0028] (3) The radome material of the formula of the present invention has excellent characteristics of high low-temperature impact performance, V1-level flame retardancy and a minimum dielectric constant of 2.2, meeting the use requirements of 5G radomes;

[0029] (4) The radome material is prepared by a long fiber infiltration process, and its pellet length can be selected according to the actual situation, maximizing the retention length of the fibers and endowing the material with optimal mechanical properties;

[0030] (5) The radome material of the present invention is applicable to various molding methods such as injection molding, compression molding, winding, and weaving, with high molding efficiency and suitable for industrial production. Description of the Drawings

[0031] By reading the detailed description of the non-limiting embodiments with reference to the following drawings, the present invention and its features and advantages will become more obvious.

[0032] Figure 1 It is an electron microscope photograph of chlorinated polyethylene fiber before and after being modified by LCP in an embodiment of the present invention. Detailed Embodiments

[0033] The technical solutions in the embodiments will be clearly and completely described below. Obviously, the embodiments described below are only a part of the embodiments of the present invention, rather than all of the embodiments.

[0034] In the following embodiments and comparative examples, the terms "comprising", "including" and any variations thereof are intended to cover non-exclusive inclusion. For example, a process, method, product that includes a series of steps or units is not limited to the listed steps or units, but optionally further includes steps or units not listed, or optionally further includes other steps or units inherent to these processes, methods, products.

[0035] In addition, the reaction devices, polypropylene, chlorinated polyethylene fiber, LCP, toughening agent, coke powder, compatibilizer, light stabilizer, antioxidant and other additives involved in the following embodiments and comparative examples are all commercially available, and the detection instruments and detection reagents involved are all commercially available.

[0036] In the following embodiments and comparative examples, the dosage of each raw material component is expressed as a percentage of the total mass of the raw materials.

[0037] In the following examples and comparative examples, the raw material information used is as follows:

[0038] Polypropylene: grade EP540V, melt flow rate of 100 g / 10 min;

[0039] Polyolefin elastomer: grade 8150, melt flow rate of 1.5 g / 10 min;

[0040] LCP powder: particle size of 3000 mesh, purchased from Suzhou Hanjin New Materials Co., Ltd.;

[0041] Chlorinated polyethylene fiber: CPE fiber, purchased from Fushun Huarui;

[0042] Quartz glass fiber: fiber diameter 10μm;

[0043] Coke powder: particle size 1500 mesh;

[0044] Ordinary glass fiber: grade T980, fiber diameter 14μm;

[0045] Compatibilizer: model CMG5701, purchased from Jiayi Rong;

[0046] Primary antioxidant: model 1010, purchased from BASF Chemical;

[0047] Secondary antioxidant: model 168, purchased from BASF Chemical;

[0048] Light stabilizer: model 5585, purchased from Xinxiu Chemical;

[0049] Lubricant: zinc stearate (ZnSt).

[0050] The following examples and comparative examples are tested by the following methods, equipment or standards:

[0051] (1) Low-temperature falling ball impact: The specimen size is a 200mm * 150mm * 3mm injection molded plate, the test temperature is -40°C, the ball weight is 500g, and the test height is 1.3m;

[0052] (2) Dielectric constant: 2.5GHz network vector analyzer (Keysight);

[0053] (3) Tensile strength: ISO527;

[0054] (4) Flexural modulus: ISO178;

[0055] (5) Flame retardant performance: UL94, vertical burning.

[0056] Example 1

[0057] This example provides a modified chlorinated polyethylene fiber, including a chlorinated polyethylene fiber matrix and LCP crosslinked on the surface of the chlorinated polyethylene fiber matrix; a graft is formed between the ester groups on the LCP molecular chain and the chlorine groups on the surface of the chlorinated polyethylene fiber. As a preferred technical solution, further: the Vicat softening point of the modified chlorinated polyethylene fiber reaches a maximum of 185°C, the thermal decomposition temperature reaches a maximum of 280°C, the fiber monofilament strength reaches a maximum of 2.4 cN / dtex, and the dielectric constant reaches a minimum of 3.6.

[0058] LCP is a polymer material containing aromatic polyester groups and generally exhibits liquid crystallinity in the molten state. Such materials have the characteristics of high strength, low dielectric constant, and self-flame retardancy, and are currently considered to be relatively ideal 5G low-dielectric materials. However, the impact performance of LCP is usually low and the price is high, so it is rarely used in materials such as protective covers. The modified chlorinated polyethylene fiber uses LCP to perform surface modification on the chlorinated polyethylene fiber matrix, effectively improving the Vicat softening point, thermal decomposition temperature, and single-filament strength of the fiber, while reducing the dielectric constant; while maintaining the characteristics of low density, high strength, impact resistance, flame retardancy, and low dielectric constant of the chlorinated polyethylene matrix fiber, the physical and chemical stability of the matrix fiber is greatly improved, avoiding fiber deformation and decomposition during subsequent processing and forming.

[0059] In this embodiment, the preparation method of the modified chlorinated polyethylene fiber is to perform surface irradiation cross-linking treatment on continuous chlorinated polyethylene fibers, specifically including the following steps: first, place the continuous chlorinated polyethylene fibers into a cross-linking treatment reactor, and then use an inert gas to introduce the liquid crystal polymer powder into the cross-linking treatment reactor to form a liquid crystal polymer atmosphere, and then turn on the irradiation source for irradiation to obtain the modified chlorinated polyethylene fiber.

[0060] The irradiation cross-linking treatment of the chlorinated polyethylene fiber is carried out in an LCP powder atmosphere. The ester groups on the LCP molecular chain will undergo a substitution reaction with the chlorine groups on the fiber surface to form a graft, further improving the heat resistance and low-dielectric characteristics of the fiber.

[0061] As a preferred technical solution, further:

[0062] The cross-linking treatment method can adopt any one or a combination of at least two of ultraviolet irradiation, γ-ray irradiation, and peroxide induction; preferably, the cross-linking treatment method adopts γ-ray irradiation cross-linking, and the cross-linking degree can be controlled by the irradiation dose; the γ-ray irradiation intensity is 100-500 kGy, preferably 200-400 kGy.

[0063] To further help understand the technical solution of this embodiment, below, through several specific examples, the technical solution of this embodiment will be described more specifically.

[0064] Example 1,

[0065] Perform surface irradiation micro-cross-linking treatment on continuous CPE fibers. The cross-linking method adopts γ-ray irradiation, and the irradiation dose is 200 kGy. Before the cross-linking irradiation treatment, use argon to introduce ultrafine LCP powder into the cross-linking treatment reaction chamber to form an LCP atmosphere, and the powder concentration is 1000 mg / L, and then turn on the γ-ray irradiation source for irradiation.

[0066] See Figure 1, the surface of the CPE fiber before and after crosslinking modification changes from smooth to rough, with granular grafts enriched. The Vicat softening point increases from 120 °C to 175 °C, the thermal decomposition temperature increases from 165 °C to 277 °C, the single-filament strength of the fiber increases from 1.2 cN / dtex to 2.3 cN / dtex, and the dielectric constant decreases from 4.2 to 3.7.

[0067] Example 2

[0068] The steps for surface irradiation micro-crosslinking treatment of continuous CPE fibers are similar to those in Example 1, except that the irradiation dose used is different, and the irradiation dose is 300 kGy. The Vicat softening point of the CPE fiber before and after crosslinking modification increases from 120 °C to 183 °C, the thermal decomposition temperature increases from 165 °C to 279 °C, the single-filament strength of the fiber increases from 1.2 cN / dtex to 2.4 cN / dtex, and the dielectric constant decreases from 4.2 to 3.6.

[0069] Example 2

[0070] This example provides a radome material, which includes polypropylene as the base component, and a toughening agent, a compatibilizer, an antioxidant, a light stabilizer, and other additives as additional components, and also includes the modified chlorinated polyethylene fiber in Example 1.

[0071] Coke powder is a common raw material in iron and steel smelting. Because it has undergone coking treatment, there are a large number of micropores inside, its dielectric constant is only 1.1 - 1.2, which is much lower than that of other filling materials, and it has a certain strength. Adding coke powder to polypropylene plastic can effectively improve its dielectric properties, and at the same time has a certain effect of enhancing and stabilizing the size. As a preferred technical solution, further: the radome material further includes quartz glass fiber and coke powder.

[0072] As a preferred technical solution, further: taking the sum of the weight percentage contents of each component of the radome material as 100%, the components include:

[0073]

[0074] Among them, the other additives include one or more of color powder, color masterbatch or lubricant.

[0075] Even further: taking the sum of the weight percentage contents of each component of the radome material as 100%, the components include:

[0076]

[0077] As a preferred technical solution, the polypropylene is a composition of one or more of homopolymer or copolymer, with a melting temperature of 130 - 180 °C, a melt flow rate of 30 - 150 g / 10 min, preferably 50 - 130 g / 10 min, and more preferably 60 - 120 g / 10 min; and / or, the toughening agent is a composition of one or more of ethylene-propylene-diene monomer (EPDM), polyolefin elastomer (POE), hydrogenated styrene-butadiene block copolymer (SEBS), and styrene-butadiene-styrene block copolymer (SBS); and / or, the modified chlorinated polyethylene fiber has a molecular weight of 100,000 - 1,000,000, preferably 200,000 - 800,000, and more preferably 300,000 - 700,000; and / or, the fiber diameter of the quartz glass fiber is 5 - 30 μm, preferably 7 - 27 μm, and more preferably 10 - 18 μm; and / or, the powder diameter of the coke powder is 500 - 3000 mesh, preferably 800 - 2500 mesh, and more preferably 1000 - 2000 mesh; and / or, the compatibilizer is selected from one or more of maleic anhydride grafted polypropylene, maleic anhydride grafted polyethylene, or maleic anhydride grafted thermoplastic polyolefin elastomer; and / or, the antioxidant includes a primary antioxidant and a secondary antioxidant. The primary antioxidant is selected from one or more of hindered phenol antioxidants and thioesters, and the secondary antioxidant is selected from phosphite antioxidants; and / or, the light stabilizer is selected from one or more of hindered amine light stabilizers, benzophenone light stabilizers, or benzotriazole light stabilizers.

[0078] The preparation method of the above radome material includes the following steps:

[0079] Step S1: Mix polypropylene, toughening agent, coke powder (if any), compatibilizer, light stabilizer, antioxidant, and other additives according to the proportioning amount, and then add them to a twin-screw extruder for melt plasticization;

[0080] Step S2: Immerse, cool, dry, pelletize or wind the modified chlorinated polyethylene fiber and quartz glass fiber (if any) in the mixture obtained by melt plasticizing in Step S1 to obtain the radome material.

[0081] As a preferred technical solution, the temperature of the melt plasticization is 180 - 270 °C, preferably 190 - 250 °C, and more preferably 200 - 230 °C; the length-diameter ratio of the screw of the twin-screw extruder is 20 - 55, preferably 25 - 50, and more preferably 30 - 48.

[0082] To further help understand the technical solution of this embodiment, below, through several specific examples and comparative examples, the technical solution of this embodiment will be described more specifically.

[0083] Example 3

[0084] First, weigh 59 wt.% of polypropylene, 10 wt.% of polyolefin elastomer, 3 wt.% of coke powder, 2 wt.% of compatibilizer, 0.4 wt.% of primary antioxidant, 0.1 wt.% of secondary antioxidant, 0.3 wt.% of light stabilizer, and 0.2 wt.% of lubricant and put them into a high-speed mixer for mixing for 5 min. Then add the mixture to a twin-screw extruder with a length-diameter ratio of 40 for plasticization, and the plasticization temperature is 210 °C.

[0085] Secondly, infiltrate 10 wt.% of the irradiated cross-linked chlorinated polyethylene fiber and 5 wt.% of quartz glass fiber in Example 1 into the mixture after the above-mentioned melt plasticization, cool, dry, and pelletize to obtain the radome material. The pellet length is controlled at 11 mm.

[0086] Refer to Table 1. Example 4 and Example 5 prepare the radome material according to a similar preparation method in Example 3, the difference being that the proportions of each raw material component are different, and the proportions are listed in Table 1.

[0087] Example 6 prepares the radome material according to a similar preparation method in Example 5, the difference being that the irradiated cross-linked chlorinated polyethylene fiber in Example 2 is used instead of the irradiated cross-linked chlorinated polyethylene fiber in Example 1 as the raw material.

[0088] Example 7 prepares the radome material according to a similar preparation method in Example 5, the difference being that the amount of coke powder is different compared with Example 5.

[0089] Example 8 prepares the radome material according to a similar preparation method in Example 5, the difference being that compared with Example 5, quartz glass fiber and coke powder are not used, and only the modified chlorinated polyethylene fiber reinforcing material is used.

[0090] Comparative Example 1 prepares the radome material according to a similar preparation method in Example 3, the difference being that compared with Examples 3 to 6, modified chlorinated polyethylene fiber, quartz glass fiber, and coke powder are not used, but 20 wt.% of ordinary glass fiber is used.

[0091] Comparative Example 2 prepares the radome material according to a similar preparation method in Example 5, the difference being that compared with Example 5, modified chlorinated polyethylene fiber and coke powder are not used.

[0092] Comparative Example 3 prepares the radome material according to a similar preparation method in Example 5, the difference being that compared with Examples 3 to 6, modified chlorinated polyethylene fiber and quartz fiber are not used.

[0093] Comparative Example 4 prepares the radome material according to a similar preparation method in Example 5, the difference being that compared with Example 5, unirradiated cross-linked chlorinated polyethylene fiber is used instead of modified chlorinated polyethylene fiber.

[0094] Table 1 Raw material components used in each example and comparative example

[0095]

[0096]

[0097] The modified polypropylene compositions obtained in the above examples and comparative examples were subjected to the following performance tests, and the test results are shown in Table 2.

[0098] Table 2 Test performance parameters of each example and comparative example

[0099]

[0100]

[0101] It can be analyzed from Table 2 that in Examples 3 to 5, the addition amount of fibers was gradually increased, the mechanical strength of the radome material was gradually improved, and the low-temperature impact performance was also improved synchronously. However, when the fiber addition amount increased to 50% and above, the dielectric constant of the material increased significantly; in Example 6, the modified chlorinated polyethylene fiber obtained in Example 2 was used, which reduced the tensile strength of the material and increased the flexural modulus, and had little effect on the application characteristics of the material; in Example 7, on the basis of Example 5, appropriately increasing the coke powder content could significantly reduce the dielectric constant of the material; from Example 8 with only modified chlorinated polyethylene fibers added, the radome material reinforced only with modified chlorinated polyethylene fibers had good low-temperature impact resistance and dielectric properties. In addition, the mechanical properties of Comparative Example 4 using unmodified chlorinated polyethylene fibers instead of modified chlorinated polyethylene fibers decreased. Comparative Example 1 toughened with ordinary glass fibers, Comparative Example 2 without using modified chlorinated polyethylene fibers and coke powder, and Comparative Example 3 without using modified chlorinated polyethylene fibers and quartz fibers all had obvious deficiencies in one or more aspects of mechanical strength, low-temperature impact resistance, dielectric constant, and flame retardancy, and did not meet the application requirements of 5G radome materials.

[0102] Example 3

[0103] This example provides a radome made of the radome material in Example 2.

[0104] In summary, the present invention discloses a modified chlorinated polyethylene fiber, a radome material containing the same, and a preparation method thereof. The modified chlorinated polyethylene fiber includes a chlorinated polyethylene fiber matrix and a liquid crystal polymer crosslinked on the surface of the chlorinated polyethylene fiber matrix. The radome material includes polypropylene as a basic component and a toughening agent, a compatibilizer, an antioxidant, a light stabilizer, and other additives as additional components, and also includes the modified chlorinated polyethylene fiber. The present invention irradiates and modifies the surface of the chlorinated polyethylene fiber to avoid fiber deformation and decomposition during the processing and molding process, and retains excellent strengthening and toughening effects; the radome material modified by using the modified chlorinated polyethylene fiber, quartz glass fiber, and coke has the characteristics of high low-temperature impact performance, V1-level flame retardancy, and a minimum dielectric constant of 2.2, meets the use requirements of 5G radomes, and is applicable to various molding methods such as injection molding, compression molding, winding, and weaving, with high molding efficiency and suitable for industrial production.

[0105] Those skilled in the art should understand that those skilled in the art can implement variation examples in combination with the prior art and the above embodiments, which will not be elaborated here. Such variation examples do not affect the essence of the present invention and will not be elaborated here.

[0106] The preferred embodiments of the present invention have been described above. It should be understood that the present invention is not limited to the above specific embodiments, and the equipment and structures not described in detail should be understood to be implemented in a common manner in the art; any person skilled in the art, without departing from the scope of the technical solution of the present invention, can make many possible changes and modifications to the technical solution of the present invention by using the methods and technical contents disclosed above, or modify it into an equivalent embodiment with equivalent changes, which does not affect the essence of the present invention. Therefore, any simple modification, equivalent change, and modification 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 still fall within the scope of the protection of the technical solution of the present invention.

Claims

1. A modified chlorinated polyethylene fiber, comprising a chlorinated polyethylene fiber matrix, characterized in that: it further comprises a liquid crystal polymer crosslinked to the surface of the chlorinated polyethylene fiber matrix; a graft is formed between the ester groups on the molecular chain of the liquid crystal polymer and the chlorine groups on the surface of the chlorinated polyethylene fiber; the surface of the chlorinated polyethylene fiber matrix is crosslinked with the liquid crystal polymer by subjecting the continuous chlorinated polyethylene fiber to surface irradiation micro-crosslinking treatment; the crosslinking treatment is carried out by any one or a combination of at least two of ultraviolet irradiation, γ-ray irradiation, and peroxide induction.

2. A modified chlorinated polyethylene fiber according to claim 1, characterized in that, the Vicat softening point of the modified chlorinated polyethylene fiber reaches up to 185 °C, the thermal decomposition temperature reaches up to 280 °C, the strength of the fiber monofilament reaches up to 2.4 cN / dtex, and the dielectric constant reaches as low as 3.

6.

3. A preparation method of a modified chlorinated polyethylene fiber, characterized in that, it is used to prepare the modified chlorinated polyethylene fiber as described in claim 1; the continuous chlorinated polyethylene fiber is subjected to surface irradiation micro-crosslinking treatment; it includes the following steps: first, the continuous chlorinated polyethylene fiber is placed into a crosslinking treatment reactor, and then the liquid crystal polymer powder is introduced into the crosslinking treatment reactor by using an inert gas to form a liquid crystal polymer atmosphere, and then the irradiation source is turned on for irradiation to obtain the modified chlorinated polyethylene fiber; wherein: the crosslinking treatment is carried out by any one or a combination of at least two of ultraviolet irradiation, γ-ray irradiation, and peroxide induction.

4. An antenna radome material, comprising polypropylene as a basic component and a toughening agent, a compatibilizer, an antioxidant, a light stabilizer, and other additives as additional components, characterized in that, it further comprises the modified chlorinated polyethylene fiber described in claim 1; calculated based on the sum of the weight percentage contents of each component of the antenna radome material being 100%, the components include: polypropylene 5-90%, toughening agent 1-30%, modified chlorinated polyethylene fiber 1-50%, quartz glass fiber 1-30%, coke powder 1-10%, compatibilizer 1-10%, antioxidant 0.1-2%, light stabilizer 0.1-2%, other additives 0.1-5%; wherein, the other additives include one or more of color powder or lubricant.

5. An antenna radome material according to claim 4, characterized in that, calculated based on the sum of the weight percentage contents of each component of the antenna radome material being 100%, the components include: polypropylene 20-70%, toughening agent 3-25%, modified chlorinated polyethylene fiber 2-45%, quartz glass fiber 2-25%, coke powder 2-8%, compatibilizer 2-8%, antioxidant 0.1-1.8%, light stabilizer 0.2-1.8%, other additives 0.1-4.5%.

6. An antenna radome material according to claim 4 or 5, characterized in that, The polypropylene is a composition of one or more of homopolymer or copolymer, with a melting temperature of 130 - 180 °C and a melt flow rate of 30 - 150 g / 10 min; and / or, the toughening agent is a composition of one or more of ethylene-propylene-diene monomer (EPDM), polyolefin elastomer (POE), hydrogenated styrene-butadiene block copolymer (SEBS), styrene-butadiene-styrene block copolymer (SBS); and / or, the modified chlorinated polyethylene fiber has a molecular weight of 1 million - 10 million; and / or, the fiber diameter of the quartz glass fiber is 5 - 30 microns; and / or, the powder diameter of the coke powder is 500 - 3000 mesh; and / or, the compatibilizer is one or more of maleic anhydride grafted polypropylene, maleic anhydride grafted polyethylene, or maleic anhydride grafted thermoplastic polyolefin elastomer; and / or, the antioxidant includes a primary antioxidant and a secondary antioxidant. The primary antioxidant is one or more of hindered phenol antioxidants, thioesters, and the secondary antioxidant is a phosphite antioxidant; and / or, the light stabilizer is one or more of hindered amine light stabilizers, benzophenone light stabilizers, or benzotriazole light stabilizers.

7. A method for preparing the radome material according to any one of claims 4 to 6, characterized in that, it comprises the following steps: Step S1: Mix the polypropylene, toughening agent, coke powder, compatibilizer, light stabilizer, antioxidant, and other additives according to the proportioning amount, and then add them to a twin-screw extruder for melting and plasticizing; Step S2: Immerse, cool, dry, pelletize or wind up the modified chlorinated polyethylene fiber and quartz glass fiber according to the proportioning amount in the mixture obtained by melting and plasticizing in Step S1 to obtain the radome material; wherein, the temperature of the melting and plasticizing is 180 - 270 °C; the length-diameter ratio of the screw of the twin-screw extruder is 20 - 55.

8. A radome, characterized in that, it is made of the radome material according to any one of claims 4 to 6 or the radome material prepared by the preparation method according to claim 7.

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