Environment-friendly flame-retardant cable material and preparation method thereof

Abstract

The invention discloses an environment-friendly flame-retardant cable material and a preparation method thereof, and belongs to the field of cable material preparation. The cable material comprises the following components in parts by weight: 60-80 parts of matrix resin, 30-40 parts of a composite flame retardant, 4-8 parts of a processing aid, 1-3 parts of a coupling agent and 3-5 parts of a compatilizer, the matrix resin is formed by compounding a polyurethane elastomer and polyborosilazane according to a ratio of (5-8): 1, and the composite flame retardant is a compound system of nano montmorillonite, zinc borate, superfine aluminum hydroxide, magnesium hydroxide and melamine. During preparation, the raw materials are mixed and then are subjected to melt extrusion granulation through a double-screw extruder, the extrusion temperature is 170-180 DEG C, and the screw rotating speed is 350-450r / min. The problems that flame retardance and mechanical performance of a traditional cable material are difficult to consider, and aging resistance is poor are solved, the oxygen index of the product is larger than or equal to 38%, the tensile strength is larger than or equal to 32 MPa, the aging-resistant tensile strength retention rate is larger than or equal to 90.2%, and the cable material has excellent comprehensive performance.

Description

Technical Field

[0001] This invention relates to the field of wire and cable technology, and in particular to an environmentally friendly flame-retardant cable material and its preparation method. Background Technology

[0002] With the rapid development of industries such as power and communications, cables, as the core carriers of energy transmission and signal transmission, are being used in increasingly wider applications, and the performance requirements for cable materials are constantly improving. Among these, flame retardancy and environmental friendliness are key performance indicators for cable materials. Especially in densely populated or enclosed spaces such as buildings, rail transit, and ships, flame-retardant cable materials can effectively delay the spread of fire and reduce casualties and property losses caused by fires.

[0003] Traditional cable materials often employ halogen-containing flame-retardant systems, which are highly efficient and cost-effective, and were once widely used in the cable industry. However, halogen-containing cable materials release toxic and harmful gases such as hydrogen chloride and hydrogen bromide during combustion, while also producing large amounts of dense smoke. This not only corrodes equipment but also hinders personnel evacuation and fire rescue operations, posing serious threats to the environment and human health. With increasingly stringent global environmental regulations, halogen-free, environmentally friendly flame-retardant cable materials have become the mainstream trend in the industry.

[0004] Currently, most mainstream halogen-free flame-retardant cable materials use inorganic hydroxides such as aluminum hydroxide (ATH) and magnesium hydroxide (MH) as flame retardants. However, these materials require an addition of more than 60% to achieve the UL94 V-0 flame-retardant rating, resulting in a significant deterioration in the mechanical properties and processing fluidity of the cable material. Besides inorganic halogen-free flame-retardant systems, existing technologies have also attempted to use organic halogen-free flame retardants (such as phosphorus-based and nitrogen-based flame retardants) to prepare cable materials. However, these flame retardants also have many insurmountable drawbacks: firstly, their flame-retardant efficiency is limited; a single organic halogen-free flame retardant requires a high filling amount to achieve the desired flame-retardant effect, which also damages the material's mechanical properties; secondly, they have poor thermal stability and are prone to decomposition during processing; and thirdly, compatibility and migration issues lead to a decline in the flame-retardant performance of the cable material after long-term use, and may also affect the surface finish and aging resistance of the material.

[0005] For example, the invention patent with authorization announcement number CN102485792B discloses an environmentally friendly flame-retardant cable material, comprising the following components and weight parts: 40-70 parts thermoplastic elastomer, 10-30 parts PVC resin, 10-14 parts nitrogen / phosphorus composite flame retardant, 0.5-2 parts antioxidant, 2-15 parts plasticizer, 0.2-0.6 parts heat stabilizer, and 2-3 parts reinforcing agent. This invention utilizes a mixture of TPEE and PVC to prepare the cable material. On the one hand, it improves the low-temperature flexibility of PVC, increasing tensile strength, elongation, hardness, and tear strength; on the other hand, PVC can improve the flame-retardant properties of the composite material, achieving the desired flame-retardant effect without adding too much flame retardant; moreover, PVC is much cheaper than TPEE, reducing costs. The flame retardant uses a blend of nitrogen and phosphorus-based flame retardants, with the addition of reinforcing agents to improve the mechanical properties of the composite material, making it applicable to mid-to-high-end wire and cable sheaths and optical fiber sheaths. However, the invention still uses PVC resin as a component, which is essentially a halogen-containing system. During combustion, it will still release trace amounts of harmful gases such as hydrogen chloride, making it difficult to fully meet the stringent requirements for halogen-free environmental protection in high-end fields such as rail transit and ships. Summary of the Invention

[0006] To address the shortcomings of existing technologies, the present invention aims to provide an environmentally friendly flame-retardant cable material and its preparation method. By optimizing the flame-retardant system compounding and preparation process, the flame-retardant performance and mechanical properties of the cable material are significantly improved while reducing the amount of flame retardant filling agent. It also boasts excellent environmental performance and low processing cost, meeting the needs of high-end application scenarios.

[0007] To achieve the above objectives, the present invention provides an environmentally friendly flame-retardant cable material, which, by weight, comprises the following raw materials: 60-80 parts of matrix resin, 30-40 parts of composite flame retardant, 4-8 parts of processing aid, 1-3 parts of coupling agent, and 3-5 parts of compatibilizer; wherein the matrix resin is a polyurethane elastomer and polyborosilicate compounded in a mass ratio of (5-8):1.

[0008] Preferably, the polyurethane elastomer is of the following grade: WHT-1180.

[0009] Preferably, the polyborosilazane is prepared according to the method of Example 1 in Chinese Patent Document CN105694049A.

[0010] Preferably, the composite flame retardant is a mixture of nano-montmorillonite, zinc borate, ultrafine aluminum hydroxide, magnesium hydroxide, and melamine in a mass ratio of (2-4):1:(3-5):3:0.5.

[0011] Preferably, the average particle size of the nano-montmorillonite is 20-60 nm; the average particle size of the ultrafine aluminum hydroxide is 0.5-1 μm; and the average particle size of the ultrafine magnesium hydroxide is 1-2 μm.

[0012] Preferably, the processing aid is a compound of plasticizer, antioxidant and lubricant in a mass ratio of (2-3):(0.5-1):(1.5-4).

[0013] Preferably, the plasticizer is epoxidized soybean oil, the antioxidant is antioxidant 1010, and the lubricant is zinc stearate.

[0014] Preferably, the coupling agent is at least one of silane coupling agent KH550, silane coupling agent KH560, and silane coupling agent KH570.

[0015] Preferably, the compatibilizer is maleic anhydride-grafted polyethylene 900E.

[0016] Another objective of this invention is to provide a method for preparing the environmentally friendly flame-retardant cable material, comprising the following steps: mixing the raw materials evenly according to their weight proportions to obtain a mixture, adding it to a twin-screw extruder for melting, extrusion, and granulation to obtain the environmentally friendly flame-retardant cable material.

[0017] Preferably, the extrusion temperature of the twin-screw extruder is 170-180℃, and the screw speed is 350-450 r / min. Detailed Implementation

[0018] This invention provides an environmentally friendly flame-retardant cable material, which, by weight, comprises the following raw materials: 60-80 parts of matrix resin, 30-40 parts of composite flame retardant, 4-8 parts of processing aid, 1-3 parts of coupling agent, and 3-5 parts of compatibilizer; wherein the matrix resin is a polyurethane elastomer and polyborosilicate compounded in a mass ratio of (5-8):1.

[0019] Preferably, the polyurethane elastomer is of the following grade: WHT-1180.

[0020] Preferably, the polyborosilazane is prepared according to the method of Example 1 in Chinese Patent Document CN105694049A.

[0021] Preferably, the composite flame retardant is a mixture of nano-montmorillonite, zinc borate, ultrafine aluminum hydroxide, magnesium hydroxide, and melamine in a mass ratio of (2-4):1:(3-5):3:0.5.

[0022] Preferably, the average particle size of the nano-montmorillonite is 20-60 nm; the average particle size of the ultrafine aluminum hydroxide is 0.5-1 μm; and the average particle size of the ultrafine magnesium hydroxide is 1-2 μm.

[0023] Preferably, the processing aid is a compound of plasticizer, antioxidant and lubricant in a mass ratio of (2-3):(0.5-1):(1.5-4).

[0024] Preferably, the plasticizer is epoxidized soybean oil, the antioxidant is antioxidant 1010, and the lubricant is zinc stearate.

[0025] Preferably, the coupling agent is at least one of silane coupling agent KH550, silane coupling agent KH560, and silane coupling agent KH570.

[0026] Preferably, the compatibilizer is maleic anhydride-grafted polyethylene 900E.

[0027] Another objective of this invention is to provide a method for preparing the environmentally friendly flame-retardant cable material, comprising the following steps: mixing the raw materials evenly according to their weight proportions to obtain a mixture, adding it to a twin-screw extruder for melting, extrusion, and granulation to obtain the environmentally friendly flame-retardant cable material.

[0028] Preferably, the extrusion temperature of the twin-screw extruder is 170-180℃, and the screw speed is 350-450 r / min.

[0029] Due to the application of the above technical solutions, this invention patent has the following advantages compared with the prior art: This technical solution achieves positive effects far exceeding conventional technologies by combining a matrix resin system of polyurethane elastomer and polyborosilicate, a composite flame retardant system of nano-montmorillonite-zinc borate-hydroxide-melamine, and an optimized extrusion process: not only does the cable material have excellent flame retardant performance and good environmental performance, breaking through the performance limits of traditional flame retardant systems, but it also breaks the industry consensus that "high addition of flame retardants leads to a decline in mechanical properties". Its core originates from the synergistic effect of the polyborosilicate ceramic layer, the montmorillonite-zinc borate catalytic carbon layer, and the hydroxide-melamine solid-gas phase dual flame retardant, while taking into account processing stability and environmental protection.

[0030] To enable those skilled in the art to better understand the present invention, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the embodiments. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art under the premise of equivalent changes and modifications should fall within the protection scope of the present invention.

[0031] Example 1

[0032] An environmentally friendly flame-retardant cable material, by weight, comprises the following raw materials: 60 parts matrix resin, 30 parts composite flame retardant, 4 parts processing aid, 1 part coupling agent, and 3 parts compatibilizer; the matrix resin is a polyurethane elastomer and polyborosilazane compounded in a mass ratio of 5:1; the polyurethane elastomer is of the following grade: WHT-1180; the polyborosilicate is prepared according to the method of Example 1 in invention patent document CN105694049A; the composite flame retardant is composed of nano-montmorillonite, zinc borate, ultrafine aluminum hydroxide, magnesium hydroxide, and melamine in a mass ratio of 2:1:3:3:0.5; the average particle size of the nano-montmorillonite is 20nm; the average particle size of the ultrafine aluminum hydroxide is 0.5μm; the average particle size of the ultrafine magnesium hydroxide is 1μm; the processing aid is composed of plasticizer, antioxidant, and lubricant in a mass ratio of 2:0.5:1.5; the plasticizer is epoxidized soybean oil, the antioxidant is antioxidant 1010, and the lubricant is zinc stearate; the coupling agent is silane coupling agent KH550; the compatibilizer is maleic anhydride grafted polyethylene 900E.

[0033] A method for preparing the environmentally friendly flame-retardant cable material includes the following steps: mixing the raw materials evenly according to their weight proportions to obtain a mixture, adding it to a twin-screw extruder for melting, extrusion, and granulation to obtain the environmentally friendly flame-retardant cable material; the extrusion temperature of the twin-screw extruder is 170℃, and the screw speed is 350r / min.

[0034] Example 2

[0035] An environmentally friendly flame-retardant cable material, by weight, comprises the following raw materials: 65 parts matrix resin, 33 parts composite flame retardant, 5 parts processing aid, 1.5 parts coupling agent, and 3.5 parts compatibilizer; the matrix resin is a polyurethane elastomer and polyborosilazane compounded in a mass ratio of 6:1; the polyurethane elastomer is of the following grade: WHT-1180; the polyborosilicate is prepared according to the method of Example 1 in invention patent document CN105694049A; the composite flame retardant is a mixture of nano-montmorillonite, zinc borate, ultrafine aluminum hydroxide, magnesium hydroxide, and melamine in a mass ratio of 2.5:1:3.5:3:0.5; the average particle size of the nano-montmorillonite is 30 nm; the average particle size of the ultrafine aluminum hydroxide is 0.7 μm; the average particle size of the ultrafine magnesium hydroxide is 1.2 μm; the processing aid is a mixture of plasticizer, antioxidant, and lubricant in a mass ratio of 2.3:0.7:2; the plasticizer is epoxidized soybean oil, the antioxidant is antioxidant 1010, and the lubricant is zinc stearate; the coupling agent is silane coupling agent KH560; the compatibilizer is maleic anhydride-grafted polyethylene 900E.

[0036] A method for preparing the environmentally friendly flame-retardant cable material includes the following steps: mixing the raw materials evenly according to their weight proportions to obtain a mixture, adding it to a twin-screw extruder for melting, extrusion, and granulation to obtain the environmentally friendly flame-retardant cable material; the extrusion temperature of the twin-screw extruder is 173℃, and the screw speed is 380r / min.

[0037] Example 3

[0038] An environmentally friendly flame-retardant cable material, by weight, comprises the following raw materials: 70 parts matrix resin, 35 parts composite flame retardant, 6 parts processing aid, 2 parts coupling agent, and 4 parts compatibilizer; the matrix resin is a polyurethane elastomer and polyborosilazane compounded in a mass ratio of 6.5:1; the polyurethane elastomer is of the following grade: WHT-1180; the polyborosilicate is prepared according to the method of Example 1 in invention patent document CN105694049A; the composite flame retardant is composed of nano-montmorillonite, zinc borate, ultrafine aluminum hydroxide, magnesium hydroxide, and melamine in a mass ratio of 3:1:4:3:0.5; the average particle size of the nano-montmorillonite is 40nm; the average particle size of the ultrafine aluminum hydroxide is 0.8μm; the average particle size of the ultrafine magnesium hydroxide is 1.5μm; the processing aid is composed of plasticizer, antioxidant, and lubricant in a mass ratio of 2.5:0.8:2.5; the plasticizer is epoxidized soybean oil, the antioxidant is antioxidant 1010, and the lubricant is zinc stearate; the coupling agent is silane coupling agent KH570; the compatibilizer is maleic anhydride-grafted polyethylene 900E.

[0039] A method for preparing the environmentally friendly flame-retardant cable material includes the following steps: mixing the raw materials evenly according to their weight proportions to obtain a mixture, adding it to a twin-screw extruder for melting, extrusion, and granulation to obtain the environmentally friendly flame-retardant cable material; the extrusion temperature of the twin-screw extruder is 175℃, and the screw speed is 400r / min.

[0040] Example 4

[0041] An environmentally friendly flame-retardant cable material, by weight, comprises the following raw materials: 60-80 parts of matrix resin, 38 parts of composite flame retardant, 7.5 parts of processing aid, 2.5 parts of coupling agent, and 4.5 parts of compatibilizer; the matrix resin is a polyurethane elastomer and polyborosilazane compounded in a mass ratio of 7.5:1; the polyurethane elastomer is of the following grade: WHT-1180; the polyborosilicate is prepared according to the method of Example 1 in invention patent document CN105694049A; the composite flame retardant is a mixture of nano-montmorillonite, zinc borate, ultrafine aluminum hydroxide, magnesium hydroxide, and melamine in a mass ratio of 3.5:1:4.5:3:0.5; the average particle size of the nano-montmorillonite is 50 nm; the average particle size of the ultrafine aluminum hydroxide is 0.9 μm; the average particle size of the ultrafine magnesium hydroxide is... The diameter is 1.8 μm; the processing aid is a compound of plasticizer, antioxidant, and lubricant in a mass ratio of 2.8:0.9:3.5; the plasticizer is epoxidized soybean oil, the antioxidant is antioxidant 1010, and the lubricant is zinc stearate; the coupling agent is a compound of silane coupling agent KH550, silane coupling agent KH560, and silane coupling agent KH570 in a mass ratio of 1:2:3; the compatibilizer is maleic anhydride-grafted polyethylene 900E.

[0042] A method for preparing the environmentally friendly flame-retardant cable material includes the following steps: mixing the raw materials evenly according to their weight proportions to obtain a mixture, adding it to a twin-screw extruder for melting, extrusion, and granulation to obtain the environmentally friendly flame-retardant cable material; the extrusion temperature of the twin-screw extruder is 178℃, and the screw speed is 440r / min.

[0043] Example 5

[0044] An environmentally friendly flame-retardant cable material, by weight, comprises the following raw materials: 80 parts matrix resin, 40 parts composite flame retardant, 8 parts processing aid, 3 parts coupling agent, and 5 parts compatibilizer; the matrix resin is a polyurethane elastomer and polyborosilazane compounded in a mass ratio of 8:1; the polyurethane elastomer is of the following grade: WHT-1180; the polyborosilicate is prepared according to the method of Example 1 in invention patent document CN105694049A; the composite flame retardant is a mixture of nano-montmorillonite, zinc borate, ultrafine aluminum hydroxide, magnesium hydroxide, and melamine in a mass ratio of 4:1:5:3:0.5; the average particle size of the nano-montmorillonite is 60nm; the average particle size of the ultrafine aluminum hydroxide is 1μm; the average particle size of the ultrafine magnesium hydroxide is 2μm; the processing aid is a mixture of plasticizer, antioxidant, and lubricant in a mass ratio of 3:1:4; the plasticizer is epoxidized soybean oil, the antioxidant is antioxidant 1010, and the lubricant is zinc stearate; the coupling agent is silane coupling agent KH550; the compatibilizer is maleic anhydride grafted polyethylene 900E.

[0045] A method for preparing the environmentally friendly flame-retardant cable material includes the following steps: mixing the raw materials evenly according to their weight proportions to obtain a mixture, adding it to a twin-screw extruder for melting, extrusion, and granulation to obtain the environmentally friendly flame-retardant cable material; the extrusion temperature of the twin-screw extruder is 180℃, and the screw speed is 450r / min.

[0046] Comparative Example 1

[0047] An environmentally friendly flame-retardant cable material and its preparation method are basically the same as those in Example 1, except that an equal amount of polyurethane elastomer is used instead of polyborosilazane.

[0048] Comparative Example 2

[0049] An environmentally friendly flame-retardant cable material and its preparation method are basically the same as in Example 1, except that an equal amount of nano-montmorillonite is used instead of zinc borate.

[0050] Comparative Example 3

[0051] An environmentally friendly flame-retardant cable material and its preparation method are basically the same as in Example 1, except that an equal amount of zinc borate is used instead of nano-montmorillonite.

[0052] The relevant performance tests were conducted using the following methods, and the test results are shown in Table 1:

[0053] (1) Tensile strength: The tensile strength was tested according to the method of ASTM D412.

[0054] (2) Aging resistance: The test was conducted in accordance with GB / T16422.2-2014 "Laboratory Light Source Exposure Test Method for Plastics - Part 2: Xenon Arc Lamp". The cable material sample was placed in a xenon arc lamp aging test chamber to simulate the light, temperature, humidity and other conditions in the natural environment. After aging for 1500 hours, it was cooled to room temperature and the tensile strength was measured again according to the method in (1). The tensile strength retention rate was statistically analyzed and calculated. The higher the value, the better the aging resistance.

[0055] (3) Oxygen index test: The test shall be conducted in accordance with GB / T 2406.2-2009.

[0056] Table 1

[0057] project Tensile strength Limiting oxygen index Aging resistance unit MPa ％ ％ Example 1 32.0 38.0 90.2 Example 2 32.8 39.5 92.5 Example 3 33.5 40.8 94.3 Example 4 34.0 41.5 95.8 Example 5 35.2 42.0 97.1 Comparative Example 1 25.5 30.2 70.0 Comparative Example 2 26.0 32.5 75.6 Comparative Example 3 27.1 33.8 77.3

[0058] The test results show that the environmentally friendly flame-retardant cable materials of Examples 1-5 exhibit a gradual increase in tensile strength (32.0-35.2 MPa), limiting oxygen index (38.0-42.0%), and aging resistance (90.2-97.1%) as the ratio of polyurethane elastomer to polyborosilicate in the matrix resin, the proportion of nano-montmorillonite in the composite flame retardant, and the extrusion process parameters are optimized. In contrast, Comparative Example 1, lacking polyborosilicate, Comparative Example 2, lacking zinc borate, and Comparative Example 3, lacking nano-montmorillonite, all show significantly inferior performance compared to the examples. This fully verifies the key role of the matrix resin compounding system and the synergistic system of the composite flame retardant in this technical solution, as well as the positive impact of process parameter optimization on performance, highlighting the excellent flame-retardant, mechanical, and aging resistance properties brought about by the synergy of multiple components.

[0059] The above description is merely a preferred embodiment of the present invention and is not intended to limit the scope of protection of the present invention. At the same time, those skilled in the art should understand and implement the above description. Therefore, any equivalent changes or modifications made without departing from the concept disclosed in the present invention should be covered within the scope of protection of the present invention.

Claims

1. An environmentally friendly flame-retardant cable material, characterized in that, The product is made from the following raw materials in parts by weight: 60-80 parts of matrix resin, 30-40 parts of composite flame retardant, 4-8 parts of processing aid, 1-3 parts of coupling agent, and 3-5 parts of compatibilizer; wherein the matrix resin is a polyurethane elastomer and polyborosilazane compounded in a mass ratio of (5-8):

1.

2. The environmentally friendly flame-retardant cable material according to claim 1, characterized in that, The polyurethane elastomer is designated as Wanthane® WHT-1180.

3. The environmentally friendly flame-retardant cable material according to claim 1, characterized in that, The composite flame retardant is a mixture of nano-montmorillonite, zinc borate, ultrafine aluminum hydroxide, magnesium hydroxide, and melamine in a mass ratio of (2-4):1:(3-5):3:0.

5.

4. The environmentally friendly flame-retardant cable material according to claim 3, characterized in that, The average particle size of the nano-montmorillonite is 20-60 nm; the average particle size of the ultrafine aluminum hydroxide is 0.5-1 μm; and the average particle size of the ultrafine magnesium hydroxide is 1-2 μm.

5. The environmentally friendly flame-retardant cable material according to claim 1, characterized in that, The processing aid is a compound of plasticizer, antioxidant and lubricant in a mass ratio of (2-3):(0.5-1):(1.5-4).

6. The environmentally friendly flame-retardant cable material according to claim 5, characterized in that, The plasticizer is epoxidized soybean oil, the antioxidant is antioxidant 1010, and the lubricant is zinc stearate.

7. The environmentally friendly flame-retardant cable material according to claim 1, characterized in that, The coupling agent is at least one of silane coupling agent KH550, silane coupling agent KH560, and silane coupling agent KH570.

8. The environmentally friendly flame-retardant cable material according to claim 1, characterized in that, The compatibilizer is maleic anhydride-grafted polyethylene 900E.

9. A method for preparing environmentally friendly flame-retardant cable material according to any one of claims 1-8, characterized in that, The process includes the following steps: mixing the raw materials evenly according to their weight proportions to obtain a mixture, adding it to a twin-screw extruder for melting, extrusion, and granulation to obtain environmentally friendly flame-retardant cable material.

10. The method for preparing the environmentally friendly flame-retardant cable material according to claim 9, characterized in that, The extrusion temperature of the twin-screw extruder is 170-180℃, and the screw speed is 350-450 r / min.