PVC (polyvinyl chloride) flame-retardant insulating material as well as preparation method and application thereof

Abstract

The invention relates to the technical field of PVC flame-retardant insulating materials, in particular to a PVC flame-retardant insulating material and a preparation method and application thereof. The PVC flame-retardant insulating material comprises the following raw materials in parts by weight: 100 parts of PVC resin, 45-55 parts of a plasticizer, 5-6 parts of a heat stabilizer, 6-15 parts of a composite flame-retardant insulating agent, 0.5-1 part of a lubricant, 0-15 parts of a modified filler and 0.3-1.3 parts of a composite antioxidant, the composite flame-retardant insulating agent is prepared from the following raw materials: phosphonitrilic chloride trimer, sodium lignin sulfonate and an aluminosilicate material. In the PVC flame-retardant insulating material provided by the invention, the composite flame-retardant insulating agent taking phosphonitrilic chloride trimer, sodium lignin sulfonate and aluminosilicate materials as raw materials is adopted, so that the use of expensive traditional flame retardants such as antimony trioxide and zinc borate is avoided.

Description

Technical Field

[0001] The present invention relates to the technical field of PVC flame - retardant insulating materials, and specifically relates to a PVC flame - retardant insulating material, a preparation method thereof, and an application thereof. Background Art

[0002] PVC flame - retardant insulating material is a kind of wire and cable insulating material processed from polyvinyl chloride (PVC) resin as the main raw material by adding auxiliaries such as plasticizers, stabilizers, flame retardants, fillers, etc. With the country's increasingly strict management of the flame - retardant characteristics of wire and cables, cable factories have higher and higher requirements for flame - retardant insulating materials. Currently, common flame - retardant insulating materials are manufactured using flame retardants such as antimony trioxide, zinc borate, aluminum hydroxide, magnesium hydroxide, phosphate esters, etc. However, antimony trioxide is expensive, has limited resources, and causes too much cost increase; zinc borate is generally used as a flame - retardant synergist, has low flame - retardant efficiency, and can only achieve an ideal flame - retardant effect in the presence of antimony trioxide, and its price is relatively high; aluminum hydroxide, magnesium hydroxide, and phosphate esters are inexpensive, but they also have the disadvantages of low flame - retardant efficiency and the need for a high addition amount. Moreover, when a large amount of flame retardant is added, there is a risk of a significant decrease in the insulating performance of the insulating material. Summary of the Invention

[0003] To solve the above problems, the present invention provides a PVC flame - retardant insulating material, a preparation method thereof, and an application thereof to solve at least one aspect of the above - mentioned technical problems.

[0004] The present invention is achieved through the following technical solutions: In a first aspect, the present invention provides a PVC flame - retardant insulating material, comprising the following raw materials in parts by weight: 100 parts of PVC resin, 45 - 55 parts of plasticizer, 5 - 6 parts of heat stabilizer, 6 - 15 parts of composite flame - retardant insulating agent, 0.5 - 1 part of lubricant, 0 - 15 parts of modified filler, 0.3 - 1.3 parts of composite antioxidant; The raw materials of the composite flame - retardant insulating agent include hexachlorocyclotriphosphazene, sodium lignosulfonate, and aluminosilicate material.

[0005] In some possible implementation manners, the mass ratio of the total mass of the hexachlorocyclotriphosphazene and the sodium lignosulfonate to the mass of the aluminosilicate material is 1:(1 - 2.5).

[0006] In some possible implementation manners, the aluminosilicate material includes at least one of kaolin, montmorillonite, and attapulgite.

[0007] In a second aspect, the present invention provides a preparation method of the above - mentioned PVC flame - retardant insulating material, comprising the following steps: Mix and melt - extrude the raw materials of the PVC flame - retardant insulating material to obtain the PVC flame - retardant insulating material; The raw materials include PVC resin, plasticizer, heat stabilizer, composite flame retardant and insulating agent, lubricant, modified filler and composite antioxidant.

[0008] In some possible implementation manners, the preparation of the composite flame retardant and insulating agent includes the following steps: A first product obtained by performing a first mixing treatment on hexachlorocyclotriphosphazene and sodium lignosulfonate;

[0009] The first product is subjected to a second mixing treatment with a silicate material to obtain the composite flame retardant and insulating agent.

[0010] In some possible implementation manners, the first mixing treatment includes the following steps: React the first mixing reaction system at a temperature of 60°C to 80°C while maintaining the pH value at 8 to 10; The first mixing reaction system contains hexachlorocyclotriphosphazene, sodium lignosulfonate, a catalyst and an aprotic organic solvent.

[0011] In some possible implementation manners, the catalyst is triethylamine.

[0012] In some possible implementation manners, the dosage of the catalyst is 0.5% to 1.5% of the total mass of the hexachlorocyclotriphosphazene and the sodium lignosulfonate.

[0013] In some possible implementation manners, the polarity of the aprotic organic solvent is 40 kcal / mol to 46 kcal / mol.

[0014] In some possible implementation manners, the aprotic organic solvent is at least one of N,N-dimethylformamide, dimethyl sulfoxide, and N-methylpyrrolidone.

[0015] In some possible implementation manners, the second mixing treatment includes the following steps: React the second mixing reaction system at a temperature of 70°C to 80°C while maintaining the pH value at 4 to 5; The second mixing reaction system contains the first product and the silicate material.

[0016] In a third aspect, the present invention provides an application of the above PVC flame retardant and insulating material in the field of cables.

[0017] The PVC flame retardant and insulating material provided by the present invention and its preparation method, compared with the prior art, have at least the following beneficial technical effects: (1)In the PVC flame-retardant insulating material provided by the present invention, a composite flame-retardant insulating agent made from hexachlorocyclotriphosphazene, sodium lignosulfonate, and aluminosilicate material is used, avoiding the use of expensive traditional flame retardants such as antimony trioxide and zinc borate.

[0018] (2)In the PVC flame-retardant insulating material provided by the present invention, the composite flame-retardant insulating agent has excellent flame-retardant and insulating properties.

[0019] (3)In the preparation method of the PVC flame-retardant insulating material provided by the present invention, in the preparation of the composite flame-retardant insulating agent, first, hexachlorocyclotriphosphazene and sodium lignosulfonate are reacted to obtain a bio-based intumescent phosphorus-nitrogen flame retardant, and then the phosphorus-nitrogen flame retardant is used to modify the aluminosilicate material. The prepared composite flame-retardant insulating agent has both flame-retardant and electrical insulating properties, and thus the PVC flame-retardant insulating material also has excellent flame-retardant and electrical insulating properties. Specific Embodiments

[0020] In order to make the objectives, technical solutions, and advantages of the present invention clearer, the present invention will be described and explained below in conjunction with embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0021] Based on the embodiments provided by the present invention, all other embodiments obtained by those of ordinary skill in the art without making creative efforts fall within the scope of protection of the present invention. And for those of ordinary skill in the art related to the content disclosed by the present invention, some design, manufacturing, or production changes based on the technical content disclosed by the present invention are only conventional technical means and should not be understood as insufficient disclosure of the content of the present invention.

[0022] If there is no special instruction, all embodiments and optional embodiments of the present invention can be combined with each other to form new technical solutions, and all technical features and optional technical features of the present invention can be combined with each other to form new technical solutions.

[0023] The first aspect of the embodiment of the present invention provides a PVC flame-retardant insulating material, which includes the following raw materials in parts by weight: 100 parts of PVC resin, 45 to 55 parts of plasticizer, 5 to 6 parts of heat stabilizer, 6 to 15 parts of composite flame-retardant insulating agent, 0.5 to 1 part of lubricant, 0 to 15 parts of modified filler, and 0.3 to 1.3 parts of composite antioxidant; The raw materials of the composite flame-retardant insulating agent include hexachlorocyclotriphosphazene, sodium lignosulfonate, and aluminosilicate material.

[0024] The PVC flame-retardant insulating material provided by the embodiment of the present invention has both excellent flame-retardant and electrical insulating properties.

[0025] In some embodiments, the PVC resin is at least one of SG-5 and SG-3.

[0026] In some embodiments, the plasticizer is at least one of dioctyl terephthalate (DOTP), triphenyl phosphate (TPP), trioctyl trimellitate (TOTM), and adipic acid-sebacic acid polyester.

[0027] In some embodiments, the heat stabilizer is at least one of calcium-zinc stearate complex and hydrotalcite.

[0028] In some embodiments, the mass ratio of the total mass of hexachlorocyclotriphosphazene and sodium lignosulfonate to the mass of the aluminosilicate material is 1:(1 - 2.5). In this case, it is ensured that the reaction product of hexachlorocyclotriphosphazene and sodium lignosulfonate completely or almost completely intercalates and modifies the aluminosilicate material.

[0029] In some embodiments, the mass ratio of hexachlorocyclotriphosphazene to sodium lignosulfonate is 1:(2 - 5). In this case, sodium lignosulfonate is in excess, ensuring that the chlorine element in hexachlorocyclotriphosphazene is fully nucleophilically substituted.

[0030] In some embodiments, the relative molecular weight of sodium lignosulfonate is 20000 - 40000.

[0031] In some embodiments, the aluminosilicate material includes at least one of kaolin, montmorillonite, and attapulgite. In this case, kaolin, montmorillonite, and attapulgite all belong to the layered silicate structure, and the layers are bonded by van der Waals bonds, with weak intermolecular forces, which is conducive to intercalation modification thereof.

[0032] In some embodiments, the lubricant is at least one of monoglyceryl stearate, oxidized polyethylene wax, calcium stearate, and zinc stearate.

[0033] In some embodiments, the modified filler is obtained by modifying the filler with a silane coupling agent. In this case, the modified filler can be well mixed with other components (such as PVC resin) in the raw material, reducing the occurrence of agglomeration and precipitation phenomena.

[0034] In some embodiments, the filler is at least one of calcium carbonate, talc powder, and silica.

[0035] In some embodiments, the compound antioxidant is a compound mixture of Irganox 1010 (hindered phenol type) and phosphite.

[0036] In some embodiments, the weight parts of Irganox 1010 (hindered phenol type) in the PVC flame-retardant insulating material are 0.1 part - 0.5 part.

[0037] In some embodiments, the weight parts of the phosphite in the PVC flame-retardant insulating material are 0.2 parts to 0.8 parts.

[0038] The second aspect of the embodiments of the present invention provides a preparation method of the above-mentioned PVC flame-retardant insulating material, including the following steps: S10. Mix and melt-extrude the raw materials of the PVC flame-retardant insulating material to obtain the PVC flame-retardant insulating material; The raw materials of the PVC flame-retardant insulating material include PVC resin, plasticizer, heat stabilizer, composite flame-retardant insulating agent, lubricant, modified filler, and composite antioxidant.

[0039] The preparation method of the PVC flame-retardant insulating material provided by the embodiments of the present invention uses a composite flame-retardant insulating agent with excellent flame-retardant and insulating properties, and the obtained PVC flame-retardant insulating material has excellent flame-retardant and electrical insulating properties.

[0040] In some embodiments, in the above step S10, the preparation of the composite flame-retardant insulating agent includes the following steps: S101. Obtain a first product by performing a first mixing treatment on hexachlorocyclotriphosphazene and sodium lignosulfonate; S102. Perform a second mixing treatment on the first product and the aluminosilicate material to obtain the composite flame-retardant insulating agent.

[0041] In the preparation of the above composite flame-retardant insulating agent, first react hexachlorocyclotriphosphazene and sodium lignosulfonate to obtain a first product, and then use the first product to intercalate and modify the aluminosilicate material. The obtained composite flame-retardant insulating agent has excellent flame-retardant and insulating properties. The composite flame-retardant insulating agent made of hexachlorocyclotriphosphazene, sodium lignosulfonate, and aluminosilicate material synergistically enhances the insulating properties of the aluminosilicate material and the product of the reaction between hexachlorocyclotriphosphazene and sodium lignosulfonate, enabling the composite flame-retardant insulating agent to have both flame-retardant and insulating properties, and improving the dispersion performance of the aluminosilicate material in the preparation of PVC resin.

[0042] In some embodiments, in the above step S101, the first mixing treatment includes the following steps: S1011. React the first mixing reaction system under the conditions of a temperature of 60°C to 80°C and a maintained pH value of 8 to 10; The first mixing reaction system contains hexachlorocyclotriphosphazene, sodium lignosulfonate, a catalyst, and an aprotic organic solvent.

[0043] In some embodiments, in the above step S1011, the reaction between hexachlorocyclotriphosphazene and sodium lignosulfonate includes the following chemical reaction equation: 。

[0044] In the above chemical reaction, as the reaction proceeds, the chlorine element in hexachlorocyclotriphosphazene can be gradually subjected to nucleophilic substitution by sodium lignosulfonate.

[0045] In some embodiments, in the above step S1011, the volume ratio of sodium lignosulfonate to aprotic organic solvent is 1:(4 - 6).

[0046] In some embodiments, in the above step S1011, the catalyst is triethylamine. In this case, triethylamine acts both as a catalyst and to a certain extent adjusts the pH value of the reaction system.

[0047] In some embodiments, in the above step S1011, the dosage of the catalyst is 0.5% - 1.5% of the total mass of hexachlorocyclotriphosphazene and sodium lignosulfonate. In this case, triethylamine can catalyze the removal of chlorine in hexachlorocyclotriphosphazene and promote the nucleophilic substitution reaction between hexachlorocyclotriphosphazene and sodium lignosulfonate.

[0048] In some embodiments, in the above step S1011, the aprotic organic solvent is at least one of N,N - dimethylformamide (DMF), dimethyl sulfoxide (DMSO), and N - methylpyrrolidone (NMP).

[0049] In some embodiments, in the above step S1011, the preparation of the first mixed reaction system includes the following steps: ① Dissolve sodium lignosulfonate in water at a temperature of 50°C - 70°C, and the amount of water is 5% - 10% of sodium lignosulfonate to obtain an aqueous solution of sodium lignosulfonate.

[0050] ② Under the stirring condition of 100 rpm - 200 rpm, add the aqueous solution of sodium lignosulfonate to the aprotic organic solvent at a rate of 60 d / min - 80 d / min to obtain a sodium lignosulfonate solution.

[0051] ③ Under the stirring condition of 100 rpm - 200 rpm, add hexachlorocyclotriphosphazene to the sodium lignosulfonate solution at a rate of 60 d / min - 80 d / min to obtain the first mixed reaction system.

[0052] In some embodiments, in the above step S1011, use Na 2 CO 3 solution to adjust the pH value of the reaction to 8 - 10.

[0053] In some embodiments, in the above step S1011, the reaction time is 5 h - 8 h.

[0054] In other embodiments, in the above step S101, the first mixed treatment includes the following steps: S1012. React the first mixed reaction system at a temperature of 60°C to 80°C while maintaining the pH value at 8 to 10, and perform the first impurity removal after the reaction.

[0055] In some embodiments, in the above step S1012, the first impurity removal step includes: Adjust the pH value of the first mixed reaction system to 5 to 6; After mixing with a precipitant, obtain a precipitate and dry it.

[0056] In the above first impurity removal step, adjusting the pH value of the first mixed reaction system to 5 to 6 can neutralize the alkali in the reaction system and stabilize the structure of the reaction product (i.e., the first product) in the first mixed reaction system; the precipitant promotes the precipitation of the reaction product.

[0057] In some embodiments, the precipitant is a mixture of methanol and ice, and the temperature of the precipitant is -20°C to -10°C. In this case, the amounts of methanol and ice are adjusted according to the required temperature of the precipitant, as long as it is within the range of -20°C to -10°C.

[0058] In some embodiments, the amount of the precipitant is 2 to 3 times the total volume of the first mixed reaction system.

[0059] In some embodiments, in the first impurity removal step, dilute hydrochloric acid is used to adjust the pH value of the reaction system to 5 to 6.

[0060] In some embodiments, in the first impurity removal step, the temperature of the first mixed reaction system is 20°C to 25°C (room temperature).

[0061] In some embodiments, in the first impurity removal step, the drying temperature is 60°C to 80°C. It should be noted that the drying time is adjusted according to the actual quality of the product and is not particularly limited in the embodiments of the present invention.

[0062] In some embodiments, in the above step S102, the second mixing treatment includes the following steps: S1021. React the second mixed reaction system at a temperature of 70°C to 80°C while maintaining the pH value at 4 to 5; The second mixed reaction system contains the first product and the aluminosilicate material.

[0063] In some embodiments, in the above step S1021, the second mixed reaction system further contains an ethanol aqueous solution, and the volume ratio of ethanol to water is (9 to 10):1.

[0064] In some embodiments, the mass-volume ratio of the aluminosilicate material to the ethanol aqueous solution is 1 g:(4 ml to 6 ml).

[0065] In some embodiments, the preparation of the second mixed reaction system includes the following steps: Under the stirring condition of 100 rpm to 200 rpm, a flame retardant material, a silicate material, and an ethanol aqueous solution are mixed to obtain a second mixed reaction system.

[0066] In some embodiments, in the above step S1021, acetic acid is used to maintain the pH value of the reaction at 4 to 5.

[0067] In some embodiments, in the above step S1021, the reaction time is 5 h to 6 h.

[0068] In other embodiments, in the above step S102, the second mixing treatment includes the following steps: S1022. The second mixed reaction system reacts under the conditions of a temperature of 70°C to 80°C and a maintained pH value of 4 to 5, and second impurity removal is performed after the reaction.

[0069] In some embodiments, in the above step S1022, the second impurity removal step includes: The second mixed reaction system is filtered to obtain a filter residue, the filter residue is washed with ethanol, and then vacuum dried at 70°C to 80°C.

[0070] In some embodiments, in the second impurity removal step, the number of ethanol washes is 2 to 4 times.

[0071] It should be noted that the vacuum drying time is adjusted according to the quality of the actual product and is not particularly limited in the embodiments of the present invention.

[0072] In some embodiments, in the above step S10, the preparation of the modified filler includes the following steps: S103. Stir and react the mixed suspension at 60°C to 80°C; The mixed suspension contains a nano filler and a silane coupling agent.

[0073] In some embodiments, in the above step S103, the preparation of the mixed suspension includes the following steps: S1031. Disperse the nano filler in the silane coupling agent solution; The silane coupling agent solution contains a silane coupling agent and an ethanol aqueous solution.

[0074] In some embodiments, in the above step S1031, the silane coupling agent is KH-560.

[0075] In some embodiments, in the above step S1031, the volume ratio of ethanol to water in the ethanol aqueous solution is (9 to 10):1.

[0076] In some embodiments, in the above step S1031, the mass ratio of the silane coupling agent to the aqueous ethanol solution is 1:(19 - 30).

[0077] In some embodiments, in the above step S1031, the mass ratio of the nano - filler to the silane coupling agent is 100:(1 - 3).

[0078] In some embodiments, in the above step S103, the stirring reaction includes the following steps: S1032. Under stirring conditions, acetic acid is dropped into the mixed suspension until the pH is 4 - 5.

[0079] In this case, after the silane coupling agent is hydrolyzed into silanol in the acidic solution, it undergoes dehydration condensation with Si - OH / Al - OH on the surface of the nano - filler to form Si - O - Si or Si - O - Al covalent bonds, thereby modifying the surface of the nano - filler.

[0080] In some embodiments, in the above step S1032, the stirring speed is 300 rpm - 500 rpm.

[0081] In some embodiments, in the above step S103, the stirring reaction time is 2 h - 4 h.

[0082] In some embodiments, in the above step S10, the preparation of the modified filler further includes the following steps: S104. The product obtained from the stirring reaction is taken, washed with ethanol, and then vacuum - dried at 60°C - 80°C.

[0083] In the above steps, washing with ethanol is used to remove the unreacted silane coupling agent.

[0084] In some embodiments, in the above step S10, the raw materials of the PVC flame - retardant insulating material are mixed and melt - extruded using a twin - screw extruder.

[0085] In some embodiments, the operating conditions of the twin - screw extruder include: Temperature: the feeding section is 130°C - 140°C, the compression section is 150°C - 160°C, the melting section is 165°C - 170°C, and the homogenizing section is 175°C - 180°C; Rotation speed: 150 rpm - 200 rpm; Extrusion pressure: 20 MPa - 35 MPa.

[0086] The following is further illustrated with specific embodiments. For the convenience of description, the modified fillers in the following embodiments are all prepared by the following steps: (1) Calcium carbonate is calcined at 110°C for 2 h and then ground to obtain nano - calcium carbonate (nano - filler).

[0087] (2) KH-560 was mixed with an ethanol aqueous solution (the volume ratio of ethanol to water was 9:1) to obtain a silane coupling agent solution.

[0088] (3) It was dispersed in the silane coupling agent solution according to the mass ratio of nano calcium carbonate to silane coupling agent of 100:1 to obtain a mixed suspension.

[0089] (3) Under the stirring condition of 400 rpm and at 80 °C, acetic acid was dropped into the mixed suspension until the pH was 4 - 5, and the reaction was carried out for 2 h.

[0090] (4) After washing twice with ethanol, it was vacuum dried at 70 °C and then ground to obtain modified calcium carbonate; the amount of ethanol used for each washing was 0.5 times the total mass of the product.

[0091] Example 1 Example 1 provides a PVC flame-retardant insulating material, which is composed of the following raw materials in parts by weight: 100 parts of PVC resin SG-5, 42 parts of dioctyl terephthalate (DOTP), 5 parts of calcium-zinc stearate complex, 6 parts of composite flame-retardant insulating agent, 0.8 part of monoglyceride stearate, 12 parts of modified calcium carbonate, 0.1 part of Irganox 1010, and 0.8 part of phosphite; Among them, the raw materials of the composite flame-retardant insulating agent are hexachlorocyclotriphosphazene, sodium lignosulfonate, and kaolin. The total mass ratio of hexachlorocyclotriphosphazene and sodium lignosulfonate to the mass of kaolin is 1:1, and the mass ratio of hexachlorocyclotriphosphazene to sodium lignosulfonate is 1:1; the relative molecular weight of sodium lignosulfonate is 30000.

[0092] This example also provides a preparation method of the PVC flame-retardant insulating material, and the steps are as follows: E1. Preparation of the composite flame-retardant insulating agent E1-1. Sodium lignosulfonate was dissolved in water at a temperature of 60 °C, and the amount of water was 5% of the mass of sodium lignosulfonate to obtain a sodium lignosulfonate aqueous solution.

[0093] E1-2. Under the stirring condition of 100 rpm, the sodium lignosulfonate aqueous solution was added to DMF at a speed of 60 d / min to obtain a sodium lignosulfonate solution, and the volume ratio of sodium lignosulfonate to DMF was 1:4.

[0094] E1-3. Under the stirring condition of 100 rpm, hexachlorocyclotriphosphazene was added to the sodium lignosulfonate solution at a speed of 70 d / min to obtain a first mixed reaction system.

[0095] E1-4. Triethylamine was used to adjust the pH value of the first mixed reaction system to 9.

[0096] E1-5. Under the conditions of a temperature of 60 °C and maintaining a pH value of 9, let the first mixed reaction system react for 8 h.

[0097] E1-6. Lower the temperature of the first mixed reaction system to room temperature, adjust the pH value of the first mixed reaction system to 5, mix it with a precipitant (a mixture of methanol and crushed ice) at a temperature of -10 °C, then filter and dry the obtained filter residue at 70 °C to obtain a flame retardant material; wherein, the amount of ice methanol used is 2 times the total volume of the first mixed reaction system.

[0098] E1-7. Under the stirring condition of 100 rpm, mix the flame retardant material, kaolin, and an ethanol aqueous solution to obtain a second mixed reaction system; wherein, in the ethanol aqueous solution, the volume ratio of ethanol to water is 9:1; the mass-volume ratio of kaolin to the ethanol aqueous solution is 1 g:5 ml.

[0099] E1-8. Adjust the pH value of the second mixed reaction system to 4 with acetic acid.

[0100] E1-9. Under the conditions of a temperature of 70 °C and maintaining a pH value of 4, let the second mixed reaction system react for 6 h.

[0101] E1-10. Filter the reacted second mixed reaction system to obtain the filter residue, wash the filter residue 3 times with ethanol, and then vacuum dry it at 70 °C to obtain a composite flame retardant and insulating agent.

[0102] E2. Using a twin-screw extruder, melt-extrude PVC resin SG-5, dioctyl terephthalate (DOTP), calcium-zinc stearate complex, composite flame retardant and insulating agent, monoglyceride stearate, modified calcium carbonate, Irganox 1010, and phosphite to obtain a PVC flame retardant and insulating material; Among them, the working conditions of the twin-screw extruder are: Temperature: the feeding section is 135 °C, the compression section is 155 °C, the melting section is 165 °C, and the homogenization section is 175 °C; Rotation speed: 180 rpm; Extrusion pressure: 30 MPa.

[0103] Example 2 Example 2 provides a PVC flame retardant and insulating material, which is composed of the following raw materials in parts by weight: 100 parts of PVC resin SG-5, 45 parts of dioctyl terephthalate (DOTP), 6 parts of calcium-zinc stearate complex, 8 parts of composite flame retardant and insulating agent, 0.5 part of monoglyceride stearate, 15 parts of modified calcium carbonate, 0.2 part of Irganox 1010, and 0.3 part of phosphite; Among them, the raw materials of the composite flame retardant insulator are hexachlorocyclotriphosphazene, sodium lignosulfonate and kaolin. The mass ratio of the total mass of hexachlorocyclotriphosphazene and sodium lignosulfonate to the mass of kaolin is 1:1, and the mass ratio of hexachlorocyclotriphosphazene to sodium lignosulfonate is 1:1.

[0104] This embodiment also provides a preparation method of the PVC flame retardant insulating material, and the steps are the same as those in Embodiment 1.

[0105] Embodiment 3 Embodiment 3 provides a PVC flame retardant insulating material, which is composed of the following raw materials in parts by weight: 100 parts of PVC resin SG-5, 50 parts of dioctyl terephthalate (DOTP), 5 parts of calcium-zinc stearate complex, 10 parts of composite flame retardant insulator, 1 part of monoglyceride stearate, 18 parts of modified calcium carbonate, 0.4 part of Irganox 1010 and 0.5 part of phosphite; Among them, the raw materials of the composite flame retardant insulator are hexachlorocyclotriphosphazene, sodium lignosulfonate and kaolin. The mass ratio of the total mass of hexachlorocyclotriphosphazene and sodium lignosulfonate to the mass of kaolin is 1:1.5, and the mass ratio of hexachlorocyclotriphosphazene to sodium lignosulfonate is 1:1.

[0106] This embodiment also provides a preparation method of the PVC flame retardant insulating material, and the steps are the same as those in Embodiment 1.

[0107] Embodiment 4 Embodiment 4 provides a PVC flame retardant insulating material, which is composed of the following raw materials in parts by weight: 100 parts of PVC resin SG-5, 55 parts of dioctyl terephthalate (DOTP), 6 parts of calcium-zinc stearate complex, 15 parts of composite flame retardant insulator, 1 part of monoglyceride stearate, 20 parts of modified calcium carbonate, 0.5 part of Irganox 1010 and 0.6 part of phosphite; Among them, the raw materials of the composite flame retardant insulator are hexachlorocyclotriphosphazene, sodium lignosulfonate and kaolin. The mass ratio of the total mass of hexachlorocyclotriphosphazene and sodium lignosulfonate to the mass of kaolin is 1:1.5, and the mass ratio of hexachlorocyclotriphosphazene to sodium lignosulfonate is 1:1.

[0108] This embodiment also provides a preparation method of the PVC flame retardant insulating material, and the steps are the same as those in Embodiment 1.

[0109] Embodiment 5 Embodiment 5 provides a preparation method of the PVC flame retardant insulating material provided in Embodiment 1. The steps are basically the same as those in Embodiment 1, except that: The reaction temperature in Step E1-5 is 70 °C and the reaction time is 7 h.

[0110] The reaction temperature in step E1-9 is 80 °C and the reaction time is 5 h.

[0111] Example 6 Example 6 provides a preparation method of the PVC flame-retardant insulating material provided in Example 1. The steps are basically the same as those in Example 1, except that: The reaction temperature in step E1-5 is 80 °C and the reaction time is 5 h.

[0112] The reaction temperature in step E1-9 is 75 °C and the reaction time is 6 h.

[0113] Comparative Example 1 Comparative Example 1 provides a PVC flame-retardant insulating material, which is composed of the following raw materials in parts by weight: 100 parts of PVC resin SG-5, 50 parts of dioctyl terephthalate (DOTP), 5 parts of calcium-zinc stearate complex, 10 parts of hexachlorocyclotriphosphazene, 1 part of monoglyceryl stearate, 18 parts of modified calcium carbonate, 0.4 part of Irganox 1010 and 0.5 part of phosphite.

[0114] Comparative Example 1 also provides a preparation method of the PVC flame-retardant insulating material provided in this comparative example. The steps are as follows: D1. Using a twin-screw extruder, melt-extrude PVC resin SG-5, dioctyl terephthalate (DOTP), calcium-zinc stearate complex, hexachlorocyclotriphosphazene, monoglyceryl stearate, modified calcium carbonate, Irganox 1010 and phosphite to obtain a PVC flame-retardant insulating material; Among them, the working conditions of the twin-screw extruder are: Temperature: feeding section 130 °C, compression section 150 °C, melting section 165 °C, homogenizing section 175 °C; Rotation speed: 150 rpm; Extrusion pressure: 20 MPa.

[0115] Comparative Example 2 Comparative Example 2 provides a PVC flame-retardant insulating material, which is composed of the following raw materials in parts by weight: 100 parts of PVC resin SG-5, 50 parts of dioctyl terephthalate (DOTP), 5 parts of calcium-zinc stearate complex, 10 parts of kaolin, 1 part of monoglyceryl stearate, 18 parts of modified calcium carbonate, 0.4 part of Irganox 1010 and 0.5 part of phosphite.

[0116] Comparative Example 2 also provides a preparation method of the PVC flame-retardant insulating material provided in this comparative example. The steps are as follows: Using a twin-screw extruder, PVC resin SG-5, dioctyl terephthalate (DOTP), calcium-zinc stearate complex, kaolin, monoglyceride stearate, modified calcium carbonate, Irganox 1010 and phosphite are melt-extruded to obtain a PVC flame-retardant insulating material; Among them, the working conditions of the twin-screw extruder are as follows: Temperature: feeding section 145 °C, compression section 165 °C, melting section 175 °C, homogenizing section 185 °C; Rotational speed: 200 rpm; Extrusion pressure: 40 MPa.

[0117] Comparative Example 3 Comparative Example 3 provides a PVC flame-retardant insulating material, which is composed of the following raw materials in parts by weight: 100 parts of PVC resin SG-5, 50 parts of dioctyl terephthalate (DOTP), 5 parts of calcium-zinc stearate complex, 2 parts of hexachlorocyclotriphosphazene, 3 parts of sodium lignosulfonate, 6 parts of kaolin, 1 part of monoglyceride stearate, 18 parts of modified calcium carbonate, 0.4 part of Irganox 1010 and 0.5 part of phosphorous acid.

[0118] This comparative example also provides a preparation method of the PVC flame-retardant insulating material provided in this comparative example, and the steps are as follows: D1. Using a twin-screw extruder, PVC resin SG-5, dioctyl terephthalate (DOTP), calcium-zinc stearate complex, hexachlorocyclotriphosphazene, sodium lignosulfonate, kaolin, monoglyceride stearate, modified calcium carbonate, Irganox1010 and phosphite are melt-extruded to obtain a PVC flame-retardant insulating material; Among them, the working conditions of the twin-screw extruder are as follows: Temperature: feeding section 130 °C, compression section 145 °C, melting section 155 °C, homogenizing section 165 °C; Rotational speed: 100 rpm; Extrusion pressure: 20 MPa.

[0119] In order to verify the progressiveness of a PVC flame-retardant insulating material and its preparation method provided in the embodiments of the present invention, the combustion performance (GB / T 2406.2), insulation performance (GB / T 1410), tensile strength and elongation at break of the PVC flame-retardant insulating materials provided in the examples and comparative examples are tested, and the test results are shown in Table 1 below.

[0120] 。

[0121] At least the following conclusions can be obtained from Table 1 above: (1) Examples 1 to 6 have very high flame retardancy levels and volume resistivities, indicating that the PVC flame retardant insulating material provided by the present invention has excellent flame retardancy and insulating properties.

[0122] (2) By comparing Examples 1 to 6 with Comparative Example 3, it can be seen that the flame retardant and insulating properties of the PVC flame retardant insulating material prepared by first preparing a composite flame retardant insulating agent made of hexachlorocyclotriphosphazene, sodium lignin sulfonate and kaolin and then mixing them with other components are significantly better than those of the PVC flame retardant insulating material prepared by directly mixing in Comparative Example 3. It can be seen that the composite flame retardant insulating agent provided by the embodiments of the present invention, the product of the reaction of kaolin with hexachlorocyclotriphosphazene and sodium lignin sulfonate have synergistic effects, and the flame retardant and insulating properties are significantly improved compared with when used alone.

[0123] It should be noted that the present invention is not limited to the above-mentioned embodiments. The above-mentioned embodiments are only examples, and the embodiments having the same structure as the technical idea and exerting the same effect within the technical solution of the present invention are all included in the technical scope of the present invention. In addition, without departing from the scope of the main purpose of the present invention, various modifications that can be thought of by those skilled in the art to the embodiments and other methods constructed by combining some of the constituent elements in the embodiments are also included in the scope of the present invention.

Claims

1. A PVC flame retardant insulating material, characterized in that: The invention comprises the following raw materials in parts by weight: 100 parts of PVC resin, 45 to 55 parts of plasticizer, 5 to 6 parts of heat stabilizer, 6 to 15 parts of composite flame retardant insulating agent, 0.5 to 1 part of lubricant, 0 to 15 parts of modified filler, 0.3 to 1.3 parts of composite antioxidant; The raw materials of the composite flame retardant insulating agent include hexachlorocyclotriphosphazene, sodium lignin sulfonate and aluminosilicate material.

2. The PVC flame retardant insulating material according to claim 1, characterized in that: The mass ratio of the total mass of the hexachlorocyclotriphosphazene and the sodium lignin sulfonate to the mass ratio of the aluminosilicate material is 1:1 to 2.

5.

3. The PVC flame retardant insulating material according to claim 1, characterized in that: The aluminosilicate material includes at least one of kaolin, montmorillonite and attapulgite.

4. A method for preparing a PVC flame retardant insulating material according to any one of claims 1 to 3, characterized in that: The steps include: Mixing and melting raw materials of PVC flame retardant insulating material and extruding them to obtain PVC flame retardant insulating material; The raw materials include PVC resin, plasticizer, heat stabilizer, composite flame retardant insulating agent, lubricant, modified filler and composite antioxidant.

5. The method for preparing a PVC flame retardant insulating material according to claim 4, characterized in that: The preparation of the composite flame retardant insulating agent comprises the following steps: A first product is obtained by subjecting hexachlorocyclotriphosphazene and sodium lignin sulfonate to a first mixing treatment; The first product is subjected to a second mixing process with an aluminosilicate material to obtain the composite flame retardant insulating agent.

6. The method for preparing a PVC flame retardant insulating material according to claim 5, characterized in that: The first mixing process comprises the following steps: The first mixed reaction system is reacted at a temperature of 60°C to 80°C and a pH value of 8 to 10; The first mixed reaction system comprises hexachlorocyclotriphosphazene, sodium lignin sulfonate, a catalyst and an aprotic organic solvent.

7. The method for preparing a PVC flame retardant insulating material according to claim 6, characterized in that: The catalyst satisfies at least one of the following (1) to (2): (1) The catalyst is triethylamine; (2) The amount of the catalyst used is 0.5% to 1.5% of the total mass of the hexachlorocyclotriphosphazene and the sodium lignin sulfonate.

8. The method for preparing a PVC flame retardant insulating material according to claim 6 or 7, characterized in that: The aprotic organic solvent satisfies at least one of the following (1) to (2): (1) The polarity of the aprotic organic solvent is 40 kcal / mol to 46 kcal / mol; (2) The aprotic organic solvent is at least one of N,N-dimethylformamide, dimethyl sulfoxide, and N-methylpyrrolidone.

9. The method for preparing a PVC flame retardant insulating material according to claim 8, characterized in that: The second mixing process comprises the following steps: The second mixed reaction system reacts at a temperature of 70°C to 80°C and maintains a pH value of 4 to 5; The second mixed reaction system comprises the first product and the aluminosilicate material.

10. Use of the PVC flame retardant insulating material according to any one of claims 1 to 3 in the field of cables.