High-toughness flame-retardant PVC cable material and preparation method thereof

Abstract

The invention belongs to the technical field of cable materials, and provides a high-toughness flame-retardant PVC cable material and a preparation method thereof. The PVC cable material comprises the following raw materials in parts by weight: 90-120 parts of PVC resin, 7-12 parts of a novel flame retardant, 8-15 parts of an environment-friendly plasticizer, 2.5-8.5 parts of modified cellulose fibers, 1-2 parts of a silane coupling agent, 1.5-3.5 parts of an antioxidant, 2-4 parts of a compound stabilizer and 1.5-3 parts of a lubricant. The novel flame retardant is modified epoxy resin synthesized by using benzylamine, paraformaldehyde and 9, 10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide as raw materials, the environment-friendly plasticizer is poly (1, 2-propylene glycol adipate), the modified cellulose fiber is eutectic solvent modified lignocellulose, and the flame retardant is a flame retardant. And then loading an ammonium polyphosphate-aluminum hydroxide double-effect flame retardant.

Description

Technical Field

[0001] The invention relates to the technical field of PVC cable materials, and more specifically, to a high-toughness flame-retardant PVC cable material and a preparation method thereof. Background Art

[0002] Polyvinyl chloride (PVC) is relatively cheap. Because it has a high content of chlorine, which can be as high as 56%, it has high heat resistance and oxygen index, is not easy to burn, and has good comprehensive performance. Therefore, it is widely used in the field of wires and cables. However, when PVC burns, it will produce HCl gas, which is very toxic and corrosive, and produces a lot of smoke; and the existing flame-retardant PVC wire and cable materials do not meet the requirements of green economic development because the antimony trioxide flame retardant added is carcinogenic. Therefore, the development of green and environmentally friendly flame-retardant PVC wire and cable materials is the future development direction of PVC wire and cable.

[0003] In the prior art, the shortcomings of PVC cable materials are as follows: (1) Long-term exposure to ultraviolet rays or high temperature environment will cause PVC to decompose and discolor, and the tensile strength and elongation at break will decrease significantly. For example, PVC sheaths are prone to brittle cracking after exposure to sunlight; (2) Plasticizers (such as DOP) can improve flexibility but reduce flame retardancy. Although flame retardants (such as chlorinated paraffin) increase the OI value, excessive addition will cause processing temperature sensitivity and easy precipitation failure. Summary of the invention

[0004] The present invention provides a high-toughness flame-retardant PVC cable material and a preparation method thereof. By adding modified epoxy resin and poly(1,2-propylene adipate), not only the plasticity and toughness of the PVC substrate are increased, but also the high temperature resistance of the PVC cable material is improved, solving the problem that the toughness of the existing PVC cable is easily deteriorated after use. A high-toughness flame-retardant PVC cable material with excellent flame retardant performance and good toughness can be prepared, which is suitable for various application scenarios of wires and cables.

[0005] In a first aspect, the present invention provides a high-toughness flame-retardant PVC cable material, comprising the following raw materials in parts by weight: 90-120 parts of PVC resin, 7-12 parts of a new flame retardant, 8-15 parts of an environmentally friendly plasticizer, 2.5-8.5 parts of modified cellulose fiber, 1-2 parts of a silane coupling agent, 1.5-3.5 parts of an antioxidant, 2-4 parts of a composite stabilizer, and 1.5-3 parts of a lubricant.

[0006] Preferably, the raw materials include the following parts by weight: 100-120 parts of PVC resin, 9-12 parts of new flame retardant, 10-15 parts of environmentally friendly plasticizer, 4.5-8.5 parts of modified cellulose fiber, 1-2 parts of silane coupling agent, 1.5-3.5 parts of antioxidant, 2-4 parts of composite stabilizer, and 1.5-3 parts of lubricant.

[0007] Preferably, the raw materials include the following parts by weight: 120 parts of PVC resin, 9 parts of new flame retardant, 15 parts of environmentally friendly plasticizer, 8.5 parts of modified cellulose fiber, 2 parts of silane coupling agent, 1.5 parts of antioxidant, 2 parts of composite stabilizer, and 2 parts of lubricant.

[0008] Preferably, the novel flame retardant is a modified epoxy resin synthesized from benzylamine, paraformaldehyde and 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide as raw materials.

[0009] Preferably, the preparation method of the novel flame retardant comprises the following steps: A1: Benzylamine and paraformaldehyde were placed in dioxane, heated to 60°C and stirred until completely dissolved, then 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide was added, and then the temperature was raised to 90°C and stirred overnight. The dioxane was removed by distillation under reduced pressure, and the yellow liquid was concentrated and freeze-dried to obtain DOPO-BZA; A2: After preheating the epoxy resin at 80°C, the flame retardant DOPO-BZA was added and stirred to obtain a DOPO-BZA / EP blend; A3: The DOPO-BZA / EP blend was fully stirred and placed in a vacuum oven to eliminate bubbles to obtain a new flame retardant.

[0010] Preferably, the environmentally friendly plasticizer is poly(1,2-propylene adipate).

[0011] Preferably, the modified cellulose fiber is prepared by modifying wood cellulose with a low eutectic solvent and loading an ammonium polyphosphate-aluminum hydroxide dual-effect flame retardant.

[0012] Preferably, the method for preparing the modified cellulose fiber comprises the following steps: B1: Choline chloride / cardanol system: Add choline chloride and cardanol into an oil bath at 100-150℃ to react and generate a transparent liquid; B2: Add oxalic acid to the transparent liquid generated in step B1 at 50-80°C, raise the temperature to obtain a transparent clear liquid again, add lignocellulose to react, and finally add ammonium polyphosphate and aluminum hydroxide, heat and stir, filter and dry to obtain modified lignocellulose.

[0013] Preferably, the antioxidant is one or more of β-(3,5-di-tert-butyl-4-hydroxyphenyl) propionate, tris[2,4-di-tert-butylphenyl]phosphite, dilauryl thiodipropionate, and 2,8-di-tert-butyl-4-methylphenol.

[0014] In a second aspect, the present invention provides a method for preparing a high-toughness flame-retardant PVC cable material, comprising the following steps: (1) Mix and stir the PVC resin and the environmentally friendly plasticizer to obtain a mixed slurry, the stirring temperature is 75-85°C, the stirring speed is 800-1000 r / min, and the stirring time is 5-10 min; (2) adding a novel flame retardant, modified cellulose fiber, an antioxidant, a silane coupling agent and a composite stabilizer to the mixed slurry obtained in step (1), mixing and stirring to obtain a mixed material; (3) placing the mixture obtained in step (2) into a twin-screw extruder for melt kneading and extrusion at an extrusion temperature of 175-185° C. to obtain a high-toughness flame-retardant PVC cable material.

[0015] Preferably, in step (2), the stirring temperature is 100-115°C, the stirring speed is 1500-2000 r / min, and the stirring time is 20-40 min; and then the temperature is lowered to 50-70°C.

[0016] Preferably, in step (3), the extrusion conditions are: the screw speed is 600-800 r / min.

[0017] In summary, the present invention has the following beneficial effects: The novel flame retardant of the present invention utilizes the highly active amine group on benzylamine and ingeniously dehydrates and condenses with the intermediate product 10-hydroxymethyl-9-oxa-10-phosphaphenanthrene-10 oxide (ODOPM), thereby introducing the N element and preparing a flame retardant of DOPO derivative: DOPO-BZA. The EP composite material has better flame retardancy and smoke suppression by a simple synthesis method and low addition rate of DOPO-BZA.

[0018] The low eutectic solvent in the modified lignocellulose prepared in the present invention is a "green" solvent, a binary and ternary eutectic system composed of a hydrogen bond donor (polyol, urea and carboxylic acid) and a hydrogen bond acceptor (quaternary ammonium salt, such as choline chloride). Due to its advantages of simple and rapid preparation, low cost, low toxicity, biodegradability, easy recycling and reuse, it has a good separation effect on lignocellulose, which is due to its ability to break the strong interaction between lignin, cellulose and hemicellulose. The biodegradability of the low eutectic solvent allows the use of a more environmentally friendly process to remove lignin and hemicellulose.

[0019] The present invention is based on polyvinyl chloride resin (PVC) and is made of cable insulation and sheath materials by adding a variety of additives and fillers. Its main features include excellent electrical properties, high temperature resistance, low temperature resistance, oil resistance, chemical resistance and good flame retardancy. PVC material has good chemical corrosion resistance and can resist corrosion from a variety of chemical substances, including acids, alkalis and other chemicals. This makes PVC cables have high stability in various chemical environments and are not easily corroded or rusted. In addition, PVC material also has good corrosion resistance to oxidants, reducing agents and strong acids, but is not suitable for strong oxidizing acid environments such as concentrated sulfuric acid and concentrated nitric acid.

[0020] The present invention not only increases the plasticity and toughness of the PVC substrate, but also improves the high temperature resistance of the PVC cable material by adding a composite stabilizer and poly(1,2-propylene adipate), thereby solving the problem that the toughness of the existing PVC cable is easily deteriorated after use. A high-toughness flame-retardant PVC cable material with excellent flame retardant properties and good toughness can be prepared, which is suitable for various application scenarios of wires and cables.

[0021] This application adds a new flame retardant, an environmentally friendly plasticizer, modified cellulose fiber and a composite stabilizer. The new flame retardant and the modified cellulose fiber work synergistically, thereby making the high-toughness flame-retardant PVC cable material significantly improved in flame retardancy, the oxygen index can reach more than 30, and the thermal stability time is improved.

[0022] It should be understood that the foregoing general description and the following detailed description are exemplary and explanatory only and are not intended to limit the scope of protection of the present invention. DETAILED DESCRIPTION

[0023] The present invention is further described in detail below in conjunction with the examples. It is particularly noted that if no specific conditions are specified in the following examples, the reactions are carried out according to conventional conditions or conditions recommended by the manufacturer. Unless otherwise specified, the raw materials used in the following examples can be obtained from common commercial sources.

[0024] Preparation Example 1 The preparation method of the novel flame retardant comprises the following steps: A1: 12g benzylamine and 23g paraformaldehyde were placed in dioxane, heated to 60°C and stirred until completely dissolved, then 15g 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide was added, and then the temperature was raised to 90°C and stirred overnight. The dioxane was removed by distillation under reduced pressure, and the yellow liquid was concentrated and freeze-dried to obtain DOPO-BZA; A2: After preheating 180 g of epoxy resin at 80° C., flame retardant DOPO-BZA was added and stirred to obtain a DOPO-BZA / EP blend; A3: 5 g of curing agent was melted at 100°C and added to the DOPO-BZA / EP blend. The mixture was fully stirred and placed in a vacuum oven to eliminate bubbles. The resulting mixture was thermally cured at 100°C for 1 h, at 150°C for 1 h, and then at 180°C for 1 h to obtain a new flame retardant.

[0025] Preparation Example 2 The preparation method of the novel flame retardant comprises the following steps: A1: 15 g of benzylamine and 28 g of paraformaldehyde were placed in dioxane, heated to 60°C and stirred until completely dissolved, then 10 g of 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide was added, and then the temperature was raised to 90°C and stirred overnight. The dioxane was removed by distillation under reduced pressure, and the yellow liquid was concentrated and freeze-dried to obtain DOPO-BZA; A2: After preheating 12 g of epoxy resin at 80°C, the flame retardant DOPO-BZA was added and stirred to obtain a DOPO-BZA / EP blend; A3: 5 g of curing agent was melted at 100°C and added to the DOPO-BZA / EP blend. The mixture was fully stirred and placed in a vacuum oven to eliminate bubbles. The resulting mixture was thermally cured at 100°C for 1 h, at 150°C for 2 h, and then at 180°C for 2 h to obtain a new flame retardant.

[0026] Preparation Example 3 The preparation method of the novel flame retardant comprises the following steps: A1: 22g benzylamine and 15g paraformaldehyde were placed in dioxane, heated to 60°C and stirred until completely dissolved, then 25g 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide was added, and then the temperature was raised to 90°C and stirred overnight. The dioxane was removed by distillation under reduced pressure, and the yellow liquid was concentrated and freeze-dried to obtain DOPO-BZA; A2: After preheating 12 g of epoxy resin at 80°C, the flame retardant DOPO-BZA was added and stirred to obtain a DOPO-BZA / EP blend; A3: 5 g of curing agent was melted at 100°C and added to the DOPO-BZA / EP blend. The mixture was fully stirred and placed in a vacuum oven to eliminate bubbles. The resulting mixture was thermally cured at 100°C for 1 h, at 150°C for 1 h, and then at 180°C for 1 h to obtain a new flame retardant.

[0027] Preparation Example 4 The method for preparing modified cellulose fiber comprises the following steps: B1: Choline chloride / cardanol system: Choline chloride is used as a hydrogen bond acceptor, and cardanol is used as a hydrogen bond acceptor. 69.5 g of choline chloride and 451.4 g of cardanol are added to a three-necked flask in an oil bath at 100°C and reacted for about 1 hour to generate a transparent liquid. Then 85 g of lignocellulose is added and reacted for 24 hours. After that, ammonium polyphosphate and aluminum hydroxide are added in a mass ratio of 1:1. The mass ratio of APP-ATH to lignocellulose is set to 8% to obtain a composite. B2: 46.8 g of oxalic acid was added to the composite at 50°C to obtain a transparent and clear liquid, and the temperature was raised to 80°C. After 20 minutes, a transparent and clear liquid was obtained again. Subsequently, 65 g of lignocellulose was added and reacted under this condition for 24 hours to obtain modified lignocellulose.

[0028] Preparation Example 5 The method for preparing modified cellulose fiber comprises the following steps: B1: Choline chloride / cardanol system: Choline chloride is used as a hydrogen bond acceptor, and cardanol is used as a hydrogen bond acceptor. 72.5 g of choline chloride and 485.6 g of cardanol are added to a three-necked flask in an oil bath at 100°C and reacted for about 1 hour to generate a transparent liquid. Then 92 g of lignocellulose is added and reacted for 24 hours. After that, ammonium polyphosphate and aluminum hydroxide are added in a mass ratio of 1:2. The mass ratio of APP-ATH to lignocellulose is set to 9% to obtain a composite. B2: 50 g of oxalic acid was added to the composite at 50°C to obtain a transparent and clear liquid, and the temperature was raised to 80°C. After 20 minutes, a transparent and clear liquid was obtained again. Subsequently, 75 g of cellulose was added and reacted under this condition for 24 hours to obtain modified cellulose.

[0029] Preparation Example 6 The method for preparing modified cellulose fiber comprises the following steps: B1: Choline chloride / cardanol system: Choline chloride is used as a hydrogen bond acceptor, and cardanol is used as a hydrogen bond acceptor. 75.2 g of choline chloride and 445.6 g of cardanol are added to a three-necked flask in an oil bath at 100°C and reacted for about 1 hour to generate a transparent liquid. Then 92 g of lignocellulose is added and reacted for 24 hours. After that, ammonium polyphosphate and aluminum hydroxide are added in a mass ratio of 1:3. The mass ratio of APP-ATH to lignocellulose is set to 12% to obtain a composite. B2: 52.8 g of oxalic acid was added to the composite at 50°C to obtain a transparent and clear liquid, and the temperature was raised to 80°C. After 20 minutes, a transparent and clear liquid was obtained again. Subsequently, 75 g of cellulose was added and reacted under this condition for 24 hours to obtain modified cellulose. Example Example

[0030] A high-toughness flame-retardant PVC cable material comprises the following raw materials in parts by weight: 90 parts of PVC resin, 7 parts of a new flame retardant, 8 parts of an environmentally friendly plasticizer, 2.8 parts of modified cellulose fibers, 1 part of a silane coupling agent, 1.5 parts of an antioxidant, 2 parts of a composite stabilizer, and 1.5 parts of a lubricant.

[0031] The environmentally friendly plasticizer is poly(1,2-propylene glycol adipate); the new flame retardant is prepared in Preparation Example 1; the modified cellulose fiber is prepared in Preparation Example 4; the antioxidant is β-(3,5-di-tert-butyl-4-hydroxyphenyl) propionate; A method for preparing a high-toughness flame-retardant PVC cable material comprises the following steps: (1) PVC resin and environmentally friendly plasticizer are mixed and stirred to obtain a mixed slurry at a stirring temperature of 75°C, a stirring speed of 800 r / min, and a stirring time of 5 min; (2) Adding a novel flame retardant, modified cellulose fiber, an antioxidant, a silane coupling agent and a composite stabilizer to the mixed slurry obtained in step (1), mixing and stirring to obtain a mixed material; the stirring temperature is 100° C., the stirring speed is 1500 r / min, and the stirring time is 20 min; then cooling to 50° C.

[0032] (3) The mixture obtained in step (2) is placed in a twin-screw extruder for melt kneading and extrusion at an extrusion temperature of 175° C. and an extrusion condition of a screw speed of 600 r / min, thereby obtaining a high-toughness flame-retardant PVC cable material. Example

[0033] A high-toughness flame-retardant PVC cable material comprises the following raw materials in parts by weight: 98 parts of PVC resin, 8 parts of a new flame retardant, 9 parts of an environmentally friendly plasticizer, 3.2 parts of modified cellulose fibers, 2 parts of a silane coupling agent, 1.8 parts of an antioxidant, 2 parts of a composite stabilizer, and 1.5 parts of a lubricant.

[0034] The environmentally friendly plasticizer is poly(1,2-propylene glycol adipate); the new flame retardant is prepared in Preparation Example 2; the modified cellulose fiber is prepared in Preparation Example 5; the antioxidant is β-(3,5-di-tert-butyl-4-hydroxyphenyl) propionate; A method for preparing a high-toughness flame-retardant PVC cable material comprises the following steps: (1) PVC resin and environmentally friendly plasticizer are mixed and stirred to obtain a mixed slurry at a stirring temperature of 75°C, a stirring speed of 1000 r / min, and a stirring time of 10 min; (2) Adding a novel flame retardant, modified cellulose fiber, an antioxidant, a silane coupling agent and a composite stabilizer to the mixed slurry obtained in step (1), mixing and stirring to obtain a mixed material; the stirring temperature is 100° C., the stirring speed is 2000 r / min, and the stirring time is 40 min; then cooling to 70° C.

[0035] (3) The mixture obtained in step (2) is placed in a twin-screw extruder for melt kneading and extrusion at an extrusion temperature of 185° C. and an extrusion condition of a screw speed of 800 r / min, thereby obtaining a high-toughness flame-retardant PVC cable material. Example

[0036] A high-toughness flame-retardant PVC cable material comprises the following raw materials in parts by weight: 100 parts of PVC resin, 8 parts of a new flame retardant, 9 parts of an environmentally friendly plasticizer, 3.5 parts of modified cellulose fibers, 1 part of a silane coupling agent, 3.2 parts of an antioxidant, 3 parts of a composite stabilizer, and 2.5 parts of a lubricant.

[0037] The environmentally friendly plasticizer is poly(1,2-propylene glycol adipate); the new flame retardant is prepared in Preparation Example 3; the modified cellulose fiber is prepared in Preparation Example 6; the antioxidant is β-(3,5-di-tert-butyl-4-hydroxyphenyl) propionate; A method for preparing a high-toughness flame-retardant PVC cable material comprises the following steps: (1) PVC resin and environmentally friendly plasticizer are mixed and stirred to obtain a mixed slurry at a stirring temperature of 85°C, a stirring speed of 1000 r / min, and a stirring time of 10 min; (2) Adding a novel flame retardant, modified cellulose fiber, an antioxidant, a silane coupling agent and a composite stabilizer to the mixed slurry obtained in step (1), mixing and stirring to obtain a mixed material; the stirring temperature is 115° C., the stirring speed is 2000 r / min, and the stirring time is 40 min; then cooling to 70° C.

[0038] (3) The mixture obtained in step (2) is placed in a twin-screw extruder for melt kneading and extrusion at an extrusion temperature of 185° C. and an extrusion condition of a screw speed of 800 r / min, thereby obtaining a high-toughness flame-retardant PVC cable material. Example

[0039] A high-toughness flame-retardant PVC cable material comprises the following raw materials in parts by weight: 120 parts of PVC resin, 12 parts of a new flame retardant, 15 parts of an environmentally friendly plasticizer, 8.5 parts of modified cellulose fibers, 2 parts of a silane coupling agent, 3.5 parts of an antioxidant, 4 parts of a composite stabilizer, and 3 parts of a lubricant.

[0040] The environmentally friendly plasticizer is poly(1,2-propylene glycol adipate); the new flame retardant is prepared in Preparation Example 1; the modified cellulose fiber is prepared in Preparation Example 4; the antioxidant is β-(3,5-di-tert-butyl-4-hydroxyphenyl) propionate; A method for preparing a high-toughness flame-retardant PVC cable material comprises the following steps: (1) PVC resin and environmentally friendly plasticizer are mixed and stirred to obtain a mixed slurry at a stirring temperature of 85°C, a stirring speed of 1000 r / min, and a stirring time of 10 min; (2) Adding a novel flame retardant, modified cellulose fiber, an antioxidant, a silane coupling agent and a composite stabilizer to the mixed slurry obtained in step (1), mixing and stirring to obtain a mixed material; the stirring temperature is 115° C., the stirring speed is 2000 r / min, and the stirring time is 20 min; then cooling to 70° C.

[0041] (3) The mixture obtained in step (2) is placed in a twin-screw extruder for melt kneading and extrusion at an extrusion temperature of 185° C. and an extrusion condition of a screw speed of 800 r / min, thereby obtaining a high-toughness flame-retardant PVC cable material.

[0042] Comparative Example 1 The preparation was carried out in the same manner as in Example 1, except that no new flame retardant was added.

[0043] Comparative Example 2 The preparation was carried out in the same manner as in Example 1, except that no modified cellulose fiber was added.

[0044] Comparative Example 3 The preparation was carried out in the same manner as in Example 1, except that no composite stabilizer was added.

[0045] Performance Test: The high-toughness flame-retardant PVC cable materials prepared in Examples 1-4 and Comparative Examples 1-4 were subjected to tensile testing (GB / T 1040-2006 standard), oxygen index testing (GB / T2406-93 standard) and ultraviolet aging testing (GB / T 16422.3-2014 standard). The results are shown in Table 1.

[0046] Table 1 Performance test results

[0047] As can be seen from Table 1, compared with the comparative example, the embodiment has higher tensile strength, elongation at break, oxygen index, and lower strength decrease rate after ultraviolet radiation. By adding a new flame retardant, an environmentally friendly plasticizer, modified cellulose fiber and a composite stabilizer, the new flame retardant and the modified cellulose fiber work synergistically, thereby making the prepared high-toughness flame-retardant PVC cable material significantly improve the flame retardant performance, the oxygen index can reach more than 30, and the thermal stability time is improved.

[0048] The above is only an exemplary embodiment of the present invention, but the protection scope of the present invention is not limited thereto. Any changes or substitutions that can be easily thought of by a person skilled in the art within the technical scope disclosed by the present invention should be included in the protection scope of the present invention. Therefore, the protection scope of the present invention should be based on the protection scope of the claims.

Claims

1. A high-toughness flame-retardant PVC cable material, characterized in that: The invention comprises the following raw materials in parts by weight: 90-120 parts of PVC resin, 7-12 parts of new flame retardant, 8-15 parts of environmentally friendly plasticizer, 2.5-8.5 parts of modified cellulose fiber, 1-2 parts of silane coupling agent, 1.5-3.5 parts of antioxidant, 2-4 parts of composite stabilizer and 1.5-3 parts of lubricant.

2. The high-toughness flame-retardant PVC cable material according to claim 1, characterized in that: The invention comprises the following raw materials in parts by weight: 100-120 parts of PVC resin, 9-12 parts of new flame retardant, 10-15 parts of environmentally friendly plasticizer, 4.5-8.5 parts of modified cellulose fiber, 1-2 parts of silane coupling agent, 1.5-3.5 parts of antioxidant, 2-4 parts of composite stabilizer and 1.5-3 parts of lubricant.

3. The high-toughness flame-retardant PVC cable material according to claim 1, characterized in that: The novel flame retardant is a modified epoxy resin synthesized from benzylamine, polyformaldehyde and 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide as raw materials.

4. The high-toughness flame-retardant PVC cable material according to claim 3, characterized in that: The preparation method of the novel flame retardant comprises the following steps: A1: Benzylamine and paraformaldehyde were placed in dioxane, heated to 60°C and stirred until completely dissolved, then 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide was added, and then the temperature was raised to 90°C and stirred overnight. The dioxane was removed by distillation under reduced pressure, and the yellow liquid was concentrated and freeze-dried to obtain DOPO-BZA; A2: After preheating the epoxy resin at 80°C, the flame retardant DOPO-BZA was added and stirred to obtain a DOPO-BZA / EP blend; A3: The DOPO-BZA / EP blend was fully stirred and placed in a vacuum oven to eliminate bubbles to obtain a new flame retardant.

5. The high-toughness flame-retardant PVC cable material according to claim 1, characterized in that: The environmentally friendly plasticizer is poly(1,2-propylene adipate); The modified cellulose fiber is prepared by modifying wood cellulose with a low eutectic solvent and loading an ammonium polyphosphate-aluminum hydroxide dual-effect flame retardant.

6. The high-toughness flame-retardant PVC cable material according to claim 5, characterized in that: The method for preparing the modified cellulose fiber comprises the following steps: B1: Choline chloride / cardanol system: Add choline chloride and cardanol into an oil bath at 100-150℃ to react and generate a transparent liquid; B2: Add oxalic acid to the transparent liquid generated in step B1 at 50-80°C, raise the temperature to obtain a transparent clear liquid again, add lignocellulose to react, and finally add ammonium polyphosphate and aluminum hydroxide, heat and stir, filter and dry to obtain modified lignocellulose.

7. The high-toughness flame-retardant PVC cable material according to claim 1, characterized in that: The antioxidant is one or more of β-(3,5-di-tert-butyl-4-hydroxyphenyl) propionate, tris[2,4-di-tert-butylphenyl]phosphite, dilauryl thiodipropionate, and 2,8-di-tert-butyl-4-methylphenol.

8. The method for preparing the high-toughness flame-retardant PVC cable material according to any one of claims 1 to 7, characterized in that: The following steps are involved: (1) Mix and stir the PVC resin and the environmentally friendly plasticizer to obtain a mixed slurry, the stirring temperature is 75-85°C, the stirring speed is 800-1000 r / min, and the stirring time is 5-10 min; (2) adding a novel flame retardant, modified cellulose fiber, an antioxidant, a silane coupling agent and a composite stabilizer to the mixed slurry obtained in step (1), mixing and stirring to obtain a mixed material; (3) placing the mixture obtained in step (2) into a twin-screw extruder for melt kneading and extrusion at an extrusion temperature of 175-185° C. to obtain a high-toughness flame-retardant PVC cable material.

9. The method for preparing the high-toughness flame-retardant PVC cable material according to claim 8, characterized in that: In step (2), the stirring temperature is 100-115°C, the stirring speed is 1500-2000 r / min, and the stirring time is 20-40 min; then the temperature is lowered to 50-70°C.

10. The method for preparing the high-toughness flame-retardant PVC cable material according to claim 8, characterized in that: In step (3), the extrusion conditions are: the screw speed is 600-800r / min.

Images