Flame-retardant fireproof cable and preparation method thereof

Abstract

The invention belongs to the technical field of cable manufacturing, and particularly relates to a flame-retardant fireproof cable and a preparation method thereof. According to the flame-retardant fireproof cable provided by the invention, the flame-retardant fireproof cable comprises a cable core material obtained by twisting copper wires and an outer sleeve layer wrapping the surface of the cable core material, and the flame-retardant fireproof cable is prepared by a preparation method. Comprising the following steps: uniformly mixing high-density polyethylene, linear low-density polyethylene, an ethylene-vinyl acetate copolymer, an antioxidant, a cerium phytate modified zirconium phosphate nanosheet, an amino acid-piperazine pyrophosphate compound flame retardant, polyethylene wax, a compatilizer and an initiator, and heating to 170-190 DEG C; and extruding through a twin-screw extruder and wrapping the surface of the cable core material with the extruded material to form an outer sleeve layer, thereby obtaining the flame-retardant fireproof cable. According to the invention, the flame-retardant material cerium phytate modified zirconium phosphate nanosheet and the amino acid-piperazine pyrophosphate compounded flame retardant are added in the preparation process of the jacket layer, so that the flame-retardant and fireproof performance of the cable can be improved at present.

Description

Technical Field

[0001] This invention belongs to the field of cable manufacturing technology. More specifically, it relates to a flame-retardant and fire-resistant cable and its preparation method. Background Technology

[0002] With the rapid development of modern power, communication, and construction industries, polyolefin-based cable materials have become key materials in cable manufacturing due to their excellent electrical insulation, chemical corrosion resistance, and processing performance. However, the inherent flammability of polyolefin resins limits their application in scenarios with stringent fire safety requirements. Therefore, developing polyolefin cable materials that combine high-efficiency flame retardancy, good mechanical properties, and low-smoke halogen-free characteristics has become a research hotspot in this field.

[0003] CN112961424A discloses a halogen-free flame-retardant fireproof cable and its preparation method. The halogen-free flame-retardant fireproof cable and its preparation method comprise the following components in parts by weight: 40-60 parts high-density polyethylene; 30-40 parts linear low-density polyethylene; 200-300 parts ethylene-vinyl acetate copolymer; 30-40 parts compatibilizer; 5-10 parts antioxidant; 5-10 parts lubricant; 10-20 parts plasticizer; 20-40 parts expandable graphite; 40-80 parts ammonium polyphosphate; and 10-20 parts modified nano-magnesium hydroxide. The preparation method involves mixing the raw materials, adding additives and stirring, extruding and granulating to obtain cable material, melting and extruding the cable material, coating it onto the surface of the wire, and cooling and solidifying. The halogen-free flame-retardant fireproof cable of this application possesses good halogen-free, flame-retardant, and heat-resistant properties without affecting the cable's strength and other mechanical properties.

[0004] CN116598054A discloses a high flame-retardant fireproof cable and its preparation method, comprising, from the inside out: a cable core, a shielding layer, and a flame-retardant fireproof outer jacket. The flame-retardant fireproof outer jacket comprises the following raw materials in parts by weight: 100 parts polystyrene, 30-40 parts low-density polyethylene, 20-25 parts methyl vinyl silicone rubber, 1-2 parts initiator, 8-12 parts borate-phytate flame retardant, and 15-20 parts octavinyl POSS-modified zirconium hydroxide. The use of the borate-phytate flame retardant effectively improves the flame-retardant and fire-resistant properties of the flame-retardant fireproof cable, and also enhances its mechanical properties, making it less prone to cracking.

[0005] CN120623620A discloses a flame-retardant fireproof cable material and its preparation method. The flame-retardant fireproof cable material provided by this invention uses low-density polyethylene resin as the matrix material, providing basic electrical insulation performance and flexibility while ensuring the material's processability. By adding nylon to the raw materials, the tensile strength of the material is improved. Furthermore, by performing multi-step processing on expandable graphite, the technical problems of poor dispersibility and easy migration failure of traditional inorganic fillers are improved. The flame-retardant fireproof cable material prepared by this invention has excellent mechanical properties, flame-retardant properties, and aging resistance, ensuring the structural stability and service life of the cable material in long-term harsh outdoor environments.

[0006] By adding flame-retardant materials during the cable manufacturing process, the flame-retardant and fire-resistant properties of the cable, as well as its mechanical properties, can be significantly improved. Based on the above, this invention provides a flame-retardant and fire-resistant cable with excellent flame-retardant and mechanical properties. Summary of the Invention

[0007] The technical problem to be solved by this invention is to overcome the defects and deficiencies of the existing technology and provide a flame-retardant and fire-resistant cable and its preparation method. The flame-retardant and fire-resistant cable provided by this invention includes a cable core material obtained by stranding copper wires and an outer jacket layer wrapped around the surface of the cable core material. The preparation method of the flame-retardant and fire-resistant cable includes the following steps: uniformly mixing high-density polyethylene, linear low-density polyethylene, ethylene-vinyl acetate copolymer, antioxidant, cerium phytate-modified zirconium phosphate nanosheets, amino acid-piperazine pyrophosphate compound flame retardant, polyethylene wax, compatibilizer, and initiator, heating to 170-190°C, and then extruding through a twin-screw extruder and wrapping it around the surface of the cable core material to form the outer jacket layer, thus obtaining the flame-retardant and fire-resistant cable. This invention improves the flame-retardant and fire-resistant performance of the cable by adding flame-retardant materials cerium phytate-modified zirconium phosphate nanosheets and amino acid-piperazine pyrophosphate compound flame retardant during the preparation of the outer jacket layer.

[0008] The purpose of this invention is to provide a method for preparing flame-retardant and fire-resistant cables.

[0009] Another objective of this invention is to provide a flame-retardant and fireproof cable.

[0010] The above-mentioned objective of this invention is achieved through the following technical solution:

[0011] A method for preparing a flame-retardant and fire-resistant cable, the flame-retardant and fire-resistant cable comprising a cable core material obtained by stranding copper wires, and an outer jacket layer wrapped around the surface of the cable core material, the method comprising the following steps:

[0012] High-density polyethylene, linear low-density polyethylene, ethylene-vinyl acetate copolymer, antioxidant, cerium phytate modified zirconium phosphate nanosheets, amino acid-piperazine pyrophosphate compound flame retardant, polyethylene wax, compatibilizer, and initiator are uniformly mixed and heated to 170-190℃. Then, the mixture is extruded through a twin-screw extruder and wrapped around the surface of the cable core material to form an outer jacket, thus obtaining the flame-retardant and fireproof cable.

[0013] Preferably, by weight: 60-80 parts of the high-density polyethylene, 35-45 parts of the linear low-density polyethylene; 15-25 parts of the ethylene-vinyl acetate copolymer; 1-2 parts of the antioxidant; 10-14 parts of the cerium phytate-modified zirconium phosphate nanosheets; 15-25 parts of the amino acid-piperazine pyrophosphate compound flame retardant; 6-8 parts of the polyethylene wax; 8-10 parts of the compatibilizer; and 1-3 parts of the initiator.

[0014] In this invention, a preferred technical solution is provided, wherein the method for preparing cerium phytate-modified zirconium phosphate nanosheets includes the following steps:

[0015] (1) Zirconium phosphate nanosheets and KH-550 were ultrasonically dispersed in deionized water, then stirred and reacted, cooled, filtered, washed and dried to obtain silanized zirconium phosphate nanosheets;

[0016] (2) The silanized zirconium phosphate nanosheets obtained in step (1) were ultrasonically dispersed in deionized water, and phytic acid and cerium salt were added in sequence. The mixture was stirred, filtered, washed, and dried to obtain phytic acid-modified zirconium phosphate nanosheets.

[0017] Preferably, in step (1), the mass ratio of zirconium phosphate nanosheets to KH-550 is 1:0.03~0.05; the stirring reaction is carried out at 40~60℃ for 2~4h; and the drying is carried out at 60-80℃ for 10-14h.

[0018] Preferably, in step (2), the mass ratio of the silanized zirconium phosphate nanosheets, phytic acid, and cerium salt is 1:1.5~4:0.4~0.8. The cerium salt is one of cerium nitrate, cerium chloride, and cerium acetate.

[0019] Preferably, in step (2), the stirring time is 40-60 min; the drying is performed at 60-80℃ for 10-14 h.

[0020] In a further preferred embodiment of the present invention, the preparation method of the amino acid-piperazine pyrophosphate compound flame retardant includes the following steps:

[0021] Amino acids and ammonium polyphosphate were added to ethanol-water mixture, and then stirred and reacted under a nitrogen atmosphere. The mixture was cooled to room temperature, filtered, washed, and vacuum dried to constant weight to obtain a lysine-piperazine pyrophosphate composite flame retardant.

[0022] Preferably, the amino acid is composed of lysine and arginine, and the mass ratio of lysine to arginine is 1:3~7; the mass ratio of the amino acid to ammonium polyphosphate is 1:1.5~2.5.

[0023] Preferably, the volume ratio of ethanol to water is 9:1; the stirring reaction conditions are stirring at 40~60℃ for 4~8h, and the vacuum drying temperature is 50~70℃.

[0024] A flame-retardant and fireproof cable is prepared based on the preparation method described above.

[0025] The present invention has the following beneficial effects:

[0026] This invention utilizes KH-550 modified zirconium phosphate nanosheets, then grafts cerium phytate onto the zirconium phosphate nanosheets to obtain a hybrid flame-retardant material. This material can be effectively dispersed in the outer jacket layer. Through the synergistic effect of N / P and Ce, the flame-retardant and fire-resistant performance of the outer jacket layer is improved. By compounding amino acids with piperazine pyrophosphate, a highly efficient synergistic flame retardancy of phosphorus, nitrogen, and carbon can be achieved, further improving the flame-retardant and fire-resistant performance of the outer jacket layer. Therefore, the flame-retardant and fire-resistant cable provided by this invention has excellent flame-retardant and fire-resistant performance. Detailed Implementation

[0027] The present invention will be further illustrated below with reference to specific embodiments, but the embodiments do not limit the present invention in any way. Unless otherwise specified, the reagents, methods, and equipment used in the present invention are conventional reagents, methods, and equipment in this technical field.

[0028] The antioxidant is dilaurate thiodipropionate; the compatibilizer is maleic acid-grafted ethylene-vinyl acetate copolymer; and the initiator is diisopropyl peroxide dicarbonate.

[0029] Unless otherwise specified, all reagents and materials used in the following examples are commercially available.

[0030] Example 1

[0031] A method for preparing a flame-retardant and fire-resistant cable, the flame-retardant and fire-resistant cable comprising a cable core material obtained by stranding copper wires, and an outer jacket layer wrapped around the surface of the cable core material, the method comprising the following steps:

[0032] High-density polyethylene, linear low-density polyethylene, ethylene-vinyl acetate copolymer, antioxidant, cerium phytate modified zirconium phosphate nanosheets, amino acid-piperazine pyrophosphate compound flame retardant, polyethylene wax, compatibilizer, and initiator are uniformly mixed and heated to 190°C. Then, the mixture is extruded through a twin-screw extruder and wrapped around the surface of the cable core material to form an outer jacket, thus obtaining the flame-retardant and fireproof cable.

[0033] By weight:

[0034] The high-density polyethylene is 80 parts, the linear low-density polyethylene is 35 parts, the ethylene-vinyl acetate copolymer is 25 parts, the antioxidant is 1 part, the phytate-modified zirconium phosphate nanosheets are 14 parts, the amino acid-piperazine pyrophosphate compound flame retardant is 15 parts, the polyethylene wax is 8 parts, the compatibilizer is 8 parts, and the initiator is 3 parts.

[0035] The preparation method of cerium phytate modified zirconium phosphate nanosheets includes the following steps:

[0036] (1) 10g of zirconium phosphate nanosheets and 0.5g of KH-550 were ultrasonically dispersed in 150mL of deionized water, and then stirred at 60℃ for 2h. After cooling, filtering, washing, and drying at 80℃ for 10h, silanized zirconium phosphate nanosheets were obtained.

[0037] (2) 1g of silanized zirconium phosphate nanosheets obtained in step (1) were ultrasonically dispersed into 100mL of deionized water, and 4g of phytic acid and 0.5g of cerium nitrate were added in sequence. The mixture was stirred for 60min, filtered, washed, and dried at 80℃ for 10h to obtain phytate-modified zirconium phosphate nanosheets.

[0038] A method for preparing an amino acid-piperazine pyrophosphate compound flame retardant, the method comprising the following steps:

[0039] 10g of amino acids and 25g of ammonium polyphosphate were added to 150mL of ethanol-water mixture (ethanol to water volume ratio of 9:1). The mixture was then stirred at 60℃ for 4h under a nitrogen atmosphere. After cooling to room temperature, the mixture was filtered, washed, and dried under vacuum at 70℃ to constant weight to obtain a lysine-piperazine pyrophosphate composite flame retardant. The amino acid mixture consisted of lysine and arginine, with a lysine to arginine mass ratio of 1:7.

[0040] Example 2

[0041] A method for preparing a flame-retardant and fire-resistant cable, the flame-retardant and fire-resistant cable comprising a cable core material obtained by stranding copper wires, and an outer jacket layer wrapped around the surface of the cable core material, the method comprising the following steps:

[0042] High-density polyethylene, linear low-density polyethylene, ethylene-vinyl acetate copolymer, antioxidant, cerium phytate-modified zirconium phosphate nanosheets, amino acid-piperazine pyrophosphate compound flame retardant, polyethylene wax, compatibilizer, and initiator are uniformly mixed and heated to 170°C. The mixture is then extruded through a twin-screw extruder and wrapped around the surface of the cable core material to form an outer jacket, thus obtaining the flame-retardant and fireproof cable.

[0043] By weight:

[0044] The high-density polyethylene is 60 parts, the linear low-density polyethylene is 45 parts, the ethylene-vinyl acetate copolymer is 15 parts, the antioxidant is 2 parts, the phytate-modified zirconium phosphate nanosheets are 10 parts, the amino acid-piperazine pyrophosphate compound flame retardant is 25 parts, the polyethylene wax is 6 parts, the compatibilizer is 10 parts, and the initiator is 1 part.

[0045] The preparation method of cerium phytate modified zirconium phosphate nanosheets includes the following steps:

[0046] (1) 10g of zirconium phosphate nanosheets and 0.3g of KH-550 were ultrasonically dispersed in 150mL of deionized water, and then stirred at 40℃ for 4h. After cooling, filtering, washing, and drying at 60℃ for 14h, silanized zirconium phosphate nanosheets were obtained.

[0047] (2) 1g of silanized zirconium phosphate nanosheets obtained in step (1) were ultrasonically dispersed into 100mL of deionized water, and 1.5g of phytic acid and 0.4g of cerium chloride were added in sequence. The mixture was stirred for 40min, filtered, washed, and dried at 60℃ for 14h to obtain phytate-modified zirconium phosphate nanosheets.

[0048] A method for preparing an amino acid-piperazine pyrophosphate compound flame retardant, the method comprising the following steps:

[0049] 10g of amino acids and 15g of ammonium polyphosphate were added to 150mL of ethanol-water (ethanol to water volume ratio of 9:1), and then stirred at 40℃ for 8h under nitrogen protection. After cooling to room temperature, the mixture was filtered, washed, and dried under vacuum at 50℃ to constant weight to obtain lysine-piperazine pyrophosphate compound flame retardant.

[0050] The amino acid is composed of lysine and arginine, and the mass ratio of lysine to arginine is 1:3.

[0051] Example 3

[0052] A method for preparing a flame-retardant and fire-resistant cable, the flame-retardant and fire-resistant cable comprising a cable core material obtained by stranding copper wires, and an outer jacket layer wrapped around the surface of the cable core material, the method comprising the following steps:

[0053] High-density polyethylene, linear low-density polyethylene, ethylene-vinyl acetate copolymer, antioxidant, cerium phytate modified zirconium phosphate nanosheets, amino acid-piperazine pyrophosphate compound flame retardant, polyethylene wax, compatibilizer, and initiator are uniformly mixed and heated to 180°C. Then, the mixture is extruded through a twin-screw extruder and wrapped around the surface of the cable core material to form an outer jacket, thus obtaining the flame-retardant and fireproof cable.

[0054] By weight:

[0055] The high-density polyethylene is 70 parts, the linear low-density polyethylene is 40 parts, the ethylene-vinyl acetate copolymer is 20 parts, the antioxidant is 1.5 parts, the phytate-modified zirconium phosphate nanosheets are 12 parts, the amino acid-piperazine pyrophosphate compound flame retardant is 20 parts, the polyethylene wax is 7 parts, the compatibilizer is 9 parts, and the initiator is 2 parts.

[0056] The preparation method of cerium phytate modified zirconium phosphate nanosheets includes the following steps:

[0057] (1) 10g of zirconium phosphate nanosheets and 0.4g of KH-550 were ultrasonically dispersed in 150mL of deionized water, and then stirred at 50℃ for 3h. After cooling, filtering, washing, and drying at 70℃ for 12h, silanized zirconium phosphate nanosheets were obtained.

[0058] (2) 1g of silanized zirconium phosphate nanosheets obtained in step (1) were ultrasonically dispersed into 100mL of deionized water, and 3g of phytic acid and 0.6g of cerium acetate were added in sequence. The mixture was stirred for 50min, filtered, washed, and dried at 70℃ for 12h to obtain phytate-modified zirconium phosphate nanosheets.

[0059] A method for preparing an amino acid-piperazine pyrophosphate compound flame retardant, the method comprising the following steps:

[0060] 10g of amino acids and 20g of ammonium polyphosphate were added to 150mL of ethanol-water (ethanol to water volume ratio of 9:1), and then stirred at 50℃ for 6h under nitrogen protection. After cooling to room temperature, the mixture was filtered, washed, and dried under vacuum at 60℃ to constant weight to obtain lysine-piperazine pyrophosphate composite flame retardant.

[0061] The amino acid is composed of lysine and arginine, and the mass ratio of lysine to arginine is 1:5.

[0062] Comparative Example 1

[0063] Except for the differences, Comparative Example 1 is exactly the same as Example 3, and the rest will not be repeated. The difference is that the preparation method of cerium phytate modified zirconium phosphate nanosheets includes the following steps:

[0064] 1 g of zirconium phosphate nanosheets were ultrasonically dispersed in 100 mL of deionized water, and 3 g of phytic acid and 0.6 g of cerium acetate were added sequentially. The mixture was stirred for 50 min, filtered, washed, and dried at 70 °C for 12 h to obtain phytate-modified zirconium phosphate nanosheets.

[0065] Comparative Example 2

[0066] Except for the differences, Comparative Example 2 is exactly the same as Example 3, and the rest will not be repeated. The differences are as follows:

[0067] A method for preparing an amino acid-piperazine pyrophosphate compound flame retardant, the method comprising the following steps:

[0068] 10g of amino acids and 20g of ammonium polyphosphate were added to 150mL of ethanol-water (ethanol to water volume ratio of 9:1), and then stirred at 50℃ for 6h under nitrogen protection. After cooling to room temperature, the mixture was filtered, washed, and dried under vacuum at 60℃ to constant weight to obtain a lysine-piperazine pyrophosphate compound flame retardant, wherein the amino acid was composed of arginine.

[0069] Comparative Example 3

[0070] Apart from the differences, Comparative Example 3 is exactly the same as Example 3, and the rest will not be repeated. The difference is that zirconium phosphate nanosheets of equal mass are used instead of cerium phytate to modify zirconium phosphate nanosheets.

[0071] Comparative Example 4

[0072] Apart from the differences, Comparative Example 4 is exactly the same as Example 3, and the rest will not be repeated. The difference is that cerium phytate modified zirconium phosphate nanosheets of equal mass are used to replace the amino acid-piperazine pyrophosphate compound flame retardant.

[0073] The performance of the flame-retardant and fire-resistant cables in Examples 1-3 and Comparative Examples 1-4 was tested. Specific test results are shown in Table 1. The specific test standards are as follows:

[0074] Limiting oxygen index (%): Tested according to GB / T 2406.2-2009;

[0075] Tensile strength (MPa): Tested according to GB / T 1040.3-2006.

[0076] Table 1

[0077]

[0078] As can be seen from the table above, the flame-retardant and fireproof cable prepared by this invention utilizes the interaction between flame retardants to give the cable excellent flame-retardant and fireproof properties, as well as good mechanical properties.

[0079] The above embodiments are preferred embodiments of the present invention, but the embodiments of the present invention are not limited to the above embodiments. Any changes, modifications, substitutions, combinations, or simplifications made without departing from the spirit and principle of the present invention shall be considered equivalent substitutions and shall be included within the protection scope of the present invention.

Claims

1. A method for preparing a flame-retardant and fire-resistant cable, characterized in that: The flame-retardant and fire-resistant cable includes a cable core material made of stranded copper wires and an outer jacket layer wrapped around the surface of the cable core material. The method for preparing the flame-retardant and fire-resistant cable includes the following steps: High-density polyethylene, linear low-density polyethylene, ethylene-vinyl acetate copolymer, antioxidant, cerium phytate modified zirconium phosphate nanosheets, amino acid-piperazine pyrophosphate compound flame retardant, polyethylene wax, compatibilizer, and initiator are uniformly mixed and heated to 170-190℃. Then, the mixture is extruded through a twin-screw extruder and wrapped around the surface of the cable core material to form an outer jacket, thus obtaining the flame-retardant and fireproof cable.

2. The preparation method according to claim 1, characterized in that: By weight: 60-80 parts of the high-density polyethylene, 35-45 parts of the linear low-density polyethylene; 15-25 parts of the ethylene-vinyl acetate copolymer; 1-2 parts of the antioxidant; 10-14 parts of the cerium phytate-modified zirconium phosphate nanosheets; 15-25 parts of the amino acid-piperazine pyrophosphate compound flame retardant; 6-8 parts of the polyethylene wax; 8-10 parts of the compatibilizer; and 1-3 parts of the initiator.

3. The preparation method according to claim 1 or 2, characterized in that: The preparation method of the cerium phytate modified zirconium phosphate nanosheets includes the following steps: (1) Zirconium phosphate nanosheets and KH-550 were ultrasonically dispersed in deionized water, then stirred and reacted, cooled, filtered, washed and dried to obtain silanized zirconium phosphate nanosheets; (2) The silanized zirconium phosphate nanosheets obtained in step (1) were ultrasonically dispersed in deionized water, and phytic acid and cerium salt were added in sequence. The mixture was stirred, filtered, washed, and dried to obtain phytic acid-modified zirconium phosphate nanosheets.

4. The preparation method according to claim 3, characterized in that: In step (1), the mass ratio of zirconium phosphate nanosheets to KH-550 is 1:0.03~0.05; the stirring reaction is carried out at 40~60℃ for 2~4h; and the drying is carried out at 60-80℃ for 10-14h.

5. The preparation method according to claim 3, characterized in that: In step (2), the mass ratio of the silanized zirconium phosphate nanosheets, phytic acid and cerium salt is 1:1.5~4:0.4~0.8; the cerium salt is one of cerium nitrate, cerium chloride and cerium acetate.

6. The preparation method according to claim 3, characterized in that: In step (2), the stirring time is 40-60 min; the drying is carried out at 60-80℃ for 10-14 h.

7. The preparation method according to claim 3, characterized in that: The preparation method of the amino acid-piperazine pyrophosphate compound flame retardant includes the following steps: Amino acids and ammonium polyphosphate were added to ethanol-water mixture, and then stirred and reacted under a nitrogen atmosphere. The mixture was cooled to room temperature, filtered, washed, and vacuum dried to constant weight to obtain a lysine-piperazine pyrophosphate composite flame retardant.

8. The preparation method according to claim 7, characterized in that: The amino acid is composed of lysine and arginine, and the mass ratio of lysine to arginine is 1:3~7; the mass ratio of the amino acid to ammonium polyphosphate is 1:1.5~2.

5.

9. The preparation method according to claim 7, characterized in that: The volume ratio of ethanol to water is 9:1; the stirring reaction conditions are 40~60℃ for 4~8h, and the vacuum drying temperature is 50~70℃.

10. A flame-retardant and fireproof cable prepared by the preparation method according to any one of claims 1-9.

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