Flexible sheath material for cable and preparation method thereof

Abstract

The invention relates to the technical field of cable materials, in particular to a flexible sheath material for a cable and a preparation method of the flexible sheath material. The flexible sheath material for the cable is prepared from the following components in parts by weight: 30 to 45 parts of SEBS (Styrene-Ethylene-Butylene-Styrene), 20 to 30 parts of POE (Polyolefin Elastomer), 15 to 25 parts of EVA (Ethylene-Vinyl Acetate), 15 to 25 parts of dioctyl sebacate, 5 to 8 parts of triphenyl phosphate, 1.5 to 2 parts of silane coupling agent KH-792, 1 to 1.5 parts of calcium stearate, 8 to 12 parts of functional additive, 1 to 1.5 parts of antioxidant, 0.6 to 1 part of light stabilizer and 8 to 12 parts of filler. The sheath material prepared by the invention not only has excellent mechanical properties and flexibility, but also has outstanding flame retardance and ultraviolet aging resistance, and the service life of the sheath material is prolonged to a certain extent while the quality of the sheath material is ensured.

Description

Technical Field

[0001] The present invention relates to the technical field of cable materials, in particular to a soft sheath material for cables and a preparation method thereof. Background Art

[0002] Cables are widely used in power transmission, communications and other fields. As an important component of cables, the performance of cable sheathing materials directly affects the service life and safety of cables. With the continuous expansion of cable application scenarios, the performance requirements for cable sheathing materials are also increasing. Not only do they need to have good flexibility to meet the needs of complex wiring environments, but they also need to have excellent flame retardant properties and anti-aging properties to ensure the safety and stability of cables during use. Traditional cable sheathing materials often have problems such as insufficient flame retardant properties, easy aging, and poor mechanical properties. The existing technology mostly uses a single flame retardant, such as aluminum hydroxide or ammonium polyphosphate. Although this can improve the flame retardancy of the sheathing material to a certain extent, the improvement rate is relatively limited. Furthermore, it also has defects such as high addition amount, poor dispersibility, and influence on mechanical properties. In addition, during long-term use, the cable sheathing material is easily affected by environmental factors such as ultraviolet rays and oxygen and ages, resulting in performance degradation and shortening the service life of the cable.

[0003] Therefore, the present invention provides a soft sheath material for cables and a preparation method thereof, aiming to solve the above-mentioned related technical problems. Summary of the Invention

[0004] The sheath material prepared by the present invention not only has excellent mechanical properties and softness, but also has outstanding flame retardancy and anti-ultraviolet aging properties, which ensures its quality while also extending its service life to a certain extent.

[0005] To achieve the above object, the present invention provides the following technical solutions: A soft sheath material for a cable, comprising the following components, by weight: 30-45 parts of SEBS, 20-30 parts of POE, 15-25 parts of EVA, 15-25 parts of dioctyl sebacate, 5-8 parts of triphenyl phosphate, 1.5-2 parts of a silane coupling agent KH-792, 1-1.5 parts of calcium stearate, 8-12 parts of a functional additive, 1-1.5 parts of an antioxidant, 0.6-1 parts of a light stabilizer, and 8-12 parts of a filler; POE: Chemical name is ethylene-α-olefin copolymer elastomer; SEBS: Chemical name is styrene-ethylene-butylene-styrene block copolymer; EVA: Chemical name is ethylene-vinyl acetate copolymer; DMF: chemical name is N,N-dimethylformamide; EDC: Chinese name is 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide hydrochloride; Antioxidant 1010: The specific ingredient is pentaerythritol tetrakis[β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate; Antioxidant 168: The specific ingredient is tris(2,4-di-tert-butylphenyl) phosphite; Antioxidant 1076: The specific ingredient is β-(3,5-di-tert-butyl-4-hydroxyphenyl) propionate; Light stabilizer UV-326: The specific ingredient is 2'-(2'-hydroxy-3'-tert-butyl-5'-methylphenyl)-5-chlorobenzotriazole; Light stabilizer UV-531: The specific ingredient is 2-hydroxy-4-n-octyloxybenzophenone.

[0006] Furthermore, the preparation method of the functional additive is: Step 1: To a 0.4-0.6 mol / L DMF solution of benzo α-pyrone-β-carboxylic acid, add 1.5-2 times the mass of EDC and 0.1-0.2 times the mass of 4-dimethylaminopyridine, respectively, and stir at room temperature for 2-3 hours under nitrogen protection; then add dropwise a 50 wt% cyclohexane hexol phosphate aqueous solution with a mass of 6-10 times the mass of 4-dimethylaminopyridine, and react at a temperature of 35-40° C. for 10-15 hours; after the reaction is completed, purify the reaction product to obtain a modifier; wherein, the pH of the cyclohexane hexol phosphate aqueous solution is adjusted to 5.5-6 with triethylamine before use; Step 2: Add the modifier into deionized water with a mass 15-20 times that of the modifier, adjust the pH to 7.5-8, and then add the resulting mixed component to an aqueous dispersion of the amino core-shell substrate with a volume 6-10 times that of the modifier and a concentration of 10-15wt%. After mixing, heat to 65-70°C and react under nitrogen protection for 8-10 hours. After the reaction is completed, cool the reaction product, centrifuge and wash it, and vacuum dry it to obtain a functional additive. The core-shell substrate is composed of ammonium polyphosphate in the core layer and an aluminum hydroxide shell layer coated on its surface.

[0007] Furthermore, the specific operation of the purification process in step 1 is as follows: the reaction product is poured into ice ether for precipitation, the precipitate is washed 3-4 times with 75-85% ethanol aqueous solution and then vacuum dried at 30-40°C for 24 hours.

[0008] Furthermore, the preparation method of the aminated core-shell substrate is: ultrasonically disperse the core-shell substrate in an ethanol aqueous solution with a volume concentration of 50-60% and a pH of 4.5-5.5, add 3-aminopropyltriethoxysilane with a mass of 0.3-0.4 times that of the core-shell substrate, mix well, and stir at a temperature of 55-65°C for 3-5 hours; after the reaction is completed, the reaction product is subjected to solid-liquid separation and vacuum drying.

[0009] Furthermore, the preparation method of the core-shell substrate is as follows: the dried ammonium polyphosphate is ultrasonically dispersed in a polyethylene glycol aqueous solution at a temperature of 65-80°C and a concentration of 0.3-0.5wt% at a dosage ratio of 50-100g / L, and a urea aqueous solution with a volume of 13-18wt% and a concentration of 20-30% and 15-25wt% of an aluminum sulfate aqueous solution are added dropwise to the resulting mixture while stirring, and the pH of the reaction system is maintained at 8.5-9.2; then, the reaction is stirred at 65-80°C for 2-4h, and then at 75-85°C for 3-5h; after the reaction is completed, the reaction product is cooled, washed with water, and vacuum dried.

[0010] Furthermore, the antioxidant is selected from any one of antioxidant 1010, antioxidant 168, and antioxidant 1076.

[0011] Furthermore, the light stabilizer is selected from any one of light stabilizer UV-326 and light stabilizer UV-531.

[0012] Furthermore, the filler is selected from any one of nano calcium carbonate and talc.

[0013] A method for preparing a soft sheath material for a cable comprises the following steps: The first step is to dry SEBS, POE and EVA at a temperature of 80-90°C until the moisture content is less than 0.1%. The dried SEBS, POE, EVA and the remaining raw materials except the functional additives and triphenyl phosphate are put into a high-speed mixer and mixed at a speed of 900-1000 r / min for 10-15 minutes. The obtained premix is ​​stored for future use. The second step is to move the premix into an internal mixer and mix it at a temperature of 120-140°C for 10-15 minutes, then add the remaining raw materials and continue mixing for 5-10 minutes; after the mixing is completed, the obtained mixture is melt-extruded through a twin-screw extruder; finally, it is water-cooled and pelletized to obtain a soft cable sheath material with a length of 3-4 mm.

[0014] Furthermore, during melt extrusion, the temperatures of each section of the twin-screw extruder are as follows: the temperature of zone 1 is 150-155°C, the temperature of zone 2 is 160-165°C, the temperature of zone 3 is 170-175°C, and the temperature of the die head is 175-180°C.

[0015] Compared with the prior art, the present invention has the following beneficial effects: 1. EDC reacts chemically with the carboxyl groups on the benzo-α-pyrone-β-carboxylic acid molecule to form a highly reactive intermediate containing an acyl group. The active hydroxyl groups in cyclohexanehexol phosphate then nucleophilically attack the highly reactive intermediate, ultimately forming a phosphate bond. During the reaction, 4-dimethylaminopyridine acts as an acyl transfer catalyst, accelerating the reaction and shortening the synthesis cycle of the modifier. The prepared modifier decomposes at high temperatures to release phosphoryl radicals, which capture hydrogen and hydroxyl radicals from the combustion chain reaction, extinguishing flames and suppressing smoke. Simultaneously, during combustion, it forms a phosphoric acid-polyphosphoric acid coating and releases gases such as ammonia and nitrogen, further enhancing its flame retardant properties. Furthermore, the modifier prepared by the present invention exhibits a certain degree of resistance to UV aging and can synergize with antioxidants and light stabilizers to effectively slow the UV aging rate of the flexible sheath material, thereby extending its service life to a certain extent. Furthermore, the grafting of organic molecules such as modifiers onto the core-shell substrate effectively improves its dispersion in SEBS, POE, and EVA, reducing agglomeration. This also allows the functional additives to be more evenly dispersed in the organic phase, effectively enhancing the flame retardancy, UV aging resistance, and related mechanical properties of the flexible cable sheathing material.

[0016] 2. The present invention prepares a core-shell flame retardant with ammonium polyphosphate as the "core" and aluminum hydroxide as the "shell" by coating the surface of ammonium polyphosphate with a relatively dense aluminum hydroxide shell layer. This core-shell substrate is then modified with 3-aminopropyltriethoxysilane to prepare an amino-containing core-shell substrate with active groups on the surface, laying a theoretical foundation for the subsequent preparation of functional additives. The amino-containing core-shell substrate is uniformly dispersed in a mixed component containing a modifier. Under the protection of nitrogen, the active groups on the surface of the amino-containing core-shell substrate react chemically with the modifier. Ultimately, the modifier is chemically bonded to the surface of the amino-containing core-shell substrate, thereby preparing a functional additive with ammonium polyphosphate as the core, the aluminum hydroxide coating layer as the secondary shell layer, and the modifier graft layer as the outer shell layer. With the synergistic cooperation between ammonium polyphosphate, aluminum hydroxide and modifier, the prepared functional additive not only has excellent flame retardant properties, but also has certain anti-ultraviolet aging properties. It is used as a raw material for preparing soft sheathing materials for cables, which can significantly improve the flame retardant properties of the sheathing material and further extend its service life. DETAILED DESCRIPTION

[0017] The following will be combined with the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the embodiments described are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making any creative efforts shall fall within the scope of protection of the present invention.

[0018] Example 1 To achieve the above object, the present invention provides the following technical solutions: A soft sheath material for a cable, comprising the following components, by weight: 30 parts of SEBS, 20 parts of POE, 15 parts of EVA, 15 parts of dioctyl sebacate, 5 parts of triphenyl phosphate, 1.5 parts of silane coupling agent KH-792, 1 part of calcium stearate, 8 parts of functional additives, 1 part of antioxidant 1010, 0.6 part of light stabilizer UV-326, and 8 parts of nano-calcium carbonate; Among them, SEBS uses Kraton G1657 (styrene content 28%, hydrogenation degree >98%); POE uses Dow ENGAGE 8842 (octene content 24%, density 0.873g / cm³); EVA uses Formosa Plastics UE638 (VA content 20%, melt index 18g / 10min).

[0019] The preparation method of the functional additive is as follows: Step 1: To a 0.4 mol / L DMF solution of benzo α-pyrone-β-carboxylic acid, 1.5 times the mass of EDC and 0.1 times the mass of benzo α-pyrone-β-carboxylic acid were added, respectively, and stirred at room temperature for 2 hours under nitrogen protection; then, a 50 wt% cyclohexane hexol phosphate aqueous solution with a mass of 6 times that of 4-dimethylaminopyridine was added dropwise, and the mixture was reacted at a temperature of 35° C. for 15 hours; after the reaction was completed, the reaction product was purified to obtain a modifier; wherein, the pH of the cyclohexane hexol phosphate aqueous solution was adjusted to 5.5 with triethylamine before use; Step 2: Add the modifier into deionized water with a mass 15 times that of the modifier, adjust the pH to 7.5, and then add the resulting mixed component to an aqueous dispersion of the amino core-shell substrate with a volume 6 times that of the modifier and a concentration of 15 wt%. After mixing, heat to 65 ° C. and keep warm under nitrogen protection for 10 hours. After the reaction is completed, the reaction product is cooled, centrifuged, washed, and vacuum-dried to obtain a functional additive. The core-shell substrate is composed of ammonium polyphosphate in the core layer and an aluminum hydroxide shell layer coated on its surface.

[0020] The specific operation of the purification process in step 1 is as follows: the reaction product is poured into ice ether for precipitation, the precipitate is washed three times with 75% ethanol aqueous solution and then vacuum-dried at 30°C for 24 hours.

[0021] The preparation method of the aminated core-shell substrate is as follows: ultrasonically disperse the core-shell substrate in an ethanol aqueous solution with a volume concentration of 50% and a pH of 4.5, add 3-aminopropyltriethoxysilane with a mass 0.3 times that of the core-shell substrate, mix well, and react at a temperature of 55°C with stirring for 5 hours; after the reaction is completed, the reaction product is subjected to solid-liquid separation and vacuum drying to obtain the obtained product.

[0022] The preparation method of the core-shell substrate is as follows: dried ammonium polyphosphate is ultrasonically dispersed in a polyethylene glycol aqueous solution at a dosage ratio of 50 g / L at 65° C. and a concentration of 0.3 wt%; a urea aqueous solution with a volume of 13 wt% and an aluminum sulfate aqueous solution with a concentration of 20% and 15 wt% are added dropwise to the resulting mixture while stirring, and the pH of the reaction system is maintained at 8.5; then, the mixture is stirred and reacted at 65° C. for 4 h, and then at 75° C. for 5 h; after the reaction is completed, the reaction product is cooled, washed with water, and vacuum dried.

[0023] A method for preparing a soft sheath material for a cable comprises the following steps: The first step is to dry SEBS, POE and EVA at a temperature of 80°C to a moisture content of 0.1%; the dried SEBS, POE, EVA and the remaining raw materials except the functional additives and triphenyl phosphate are put into a high-speed mixer and mixed at a speed of 900 r / min for 15 minutes. The obtained premix is ​​stored for future use; In the second step, the premix is ​​transferred to an internal mixer and internally mixed at 120°C for 15 minutes, and then the remaining raw materials are added and the internal mixing is continued for 5 minutes. After the internal mixing is completed, the obtained mixture is melt-extruded through a twin-screw extruder. Finally, it is water-cooled and pelletized to obtain a soft cable sheath material with a length of 3 mm.

[0024] During melt extrusion, the temperatures of each section of the twin-screw extruder are as follows: the temperature of zone 1 is 150°C, the temperature of zone 2 is 160-165°C, the temperature of zone 3 is 170°C, and the temperature of the die head is 180°C.

[0025] Example 2 The preparation method of a soft sheath material for a cable provided in this embodiment is basically the same as that in Example 1, except that the specific composition of the sheath material and the preparation method of the functional additive are not exactly the same. The specific composition of the sheath material and the preparation method of the functional additive in this embodiment are as follows: A soft sheath material for a cable comprises the following components, by weight: 40 parts of SEBS, 25 parts of POE, 20 parts of EVA, 20 parts of dioctyl sebacate, 6 parts of triphenyl phosphate, 2 parts of a silane coupling agent KH-792, 1.5 parts of calcium stearate, 10 parts of a functional additive, 1.2 parts of an antioxidant 168, 0.8 parts of a light stabilizer UV-531, and 10 parts of nano-calcium carbonate.

[0026] The preparation method of the functional additive is as follows: Step 1: To a 0.5 mol / L DMF solution of benzo α-pyrone-β-carboxylic acid, 1.5 times the mass of EDC and 0.15 times the mass of benzo α-pyrone-β-carboxylic acid were added, respectively, and stirred at room temperature for 3 hours under nitrogen protection; then, a 50 wt% cyclohexane hexol phosphate aqueous solution with a mass of 8 times that of 4-dimethylaminopyridine was added dropwise, and the mixture was reacted at a temperature of 40° C. for 12 hours; after the reaction was completed, the reaction product was purified to obtain a modifier; wherein, the pH of the cyclohexane hexol phosphate aqueous solution was adjusted to 5.8 with triethylamine before use; Step 2: Add the modifier into deionized water with a mass 20 times that of the modifier, adjust the pH to 7.8, and then add the resulting mixed component to an aqueous dispersion of the amino core-shell substrate with a volume 8 times that of the modifier and a concentration of 12 wt%. After mixing, heat to 70 ° C. and keep warm for 10 hours under nitrogen protection. After the reaction is completed, the reaction product is cooled, centrifuged, washed, and vacuum-dried to obtain a functional additive. The core-shell substrate is composed of ammonium polyphosphate in the core layer and an aluminum hydroxide shell layer coated on its surface.

[0027] The specific operation of the purification process in step 1 is as follows: the reaction product is poured into ice ether for precipitation, the precipitate is washed four times with 80% ethanol aqueous solution by volume, and then vacuum-dried at 35°C for 24 hours.

[0028] The preparation method of the aminated core-shell substrate is as follows: ultrasonically disperse the core-shell substrate in an ethanol aqueous solution with a volume concentration of 55% and a pH of 5, add 3-aminopropyltriethoxysilane with a mass 0.35 times that of the core-shell substrate, mix well, and react at a temperature of 60°C with stirring for 4 hours; after the reaction is completed, the reaction product is subjected to solid-liquid separation and vacuum drying to obtain the obtained product.

[0029] The preparation method of the core-shell substrate is as follows: dried ammonium polyphosphate is ultrasonically dispersed in a polyethylene glycol aqueous solution at a temperature of 70°C and a concentration of 0.4wt% at a dosage ratio of 80g / L, and a urea aqueous solution with a volume of 15wt% and a 25% aluminum sulfate aqueous solution with a concentration of 20wt% are added dropwise to the resulting mixture while stirring, and the pH of the reaction system is maintained at 9; then, the reaction is stirred at 70°C for 3h, and then at 80°C for 4h; after the reaction is completed, the reaction product is cooled, washed with water, and vacuum dried.

[0030] Example 3 The preparation method of a soft sheath material for a cable provided in this embodiment is basically the same as that in Example 1, except that the specific composition of the sheath material and the preparation method of the functional additive are not exactly the same. The specific composition of the sheath material and the preparation method of the functional additive in this embodiment are as follows: A soft sheath material for a cable comprises the following components, by weight: 45 parts of SEBS, 30 parts of POE, 25 parts of EVA, 25 parts of dioctyl sebacate, 8 parts of triphenyl phosphate, 2 parts of a silane coupling agent KH-792, 1.5 parts of calcium stearate, 12 parts of a functional additive, 1.5 parts of an antioxidant 1010, 1 part of a light stabilizer UV-531, and 12 parts of nano-calcium carbonate.

[0031] The preparation method of the functional additive is as follows: Step 1: To a 0.6 mol / L DMF solution of benzo α-pyrone-β-carboxylic acid, add EDC (2 times the mass of benzo α-pyrone-β-carboxylic acid) and 0.2 times the mass of 4-dimethylaminopyridine, respectively, and stir at room temperature for 3 hours under nitrogen protection; then, add dropwise a cyclohexane hexol phosphate aqueous solution (8 times the mass of 4-dimethylaminopyridine and a concentration of 50 wt%), and react at a temperature of 35° C. for 15 hours; after the reaction is completed, purify the reaction product to obtain a modifier; wherein, the cyclohexane hexol phosphate aqueous solution is adjusted to pH 6 with triethylamine before use; Step 2: Add the modifier into deionized water with a mass 20 times that of the modifier, adjust the pH to 8, and then add the resulting mixed component to an aqueous dispersion of the amino core-shell substrate with a volume 10 times that of the modifier and a concentration of 15 wt%. After mixing, heat to 70 ° C. and keep warm for 8 hours under nitrogen protection. After the reaction is completed, the reaction product is cooled, centrifuged, washed, and vacuum-dried to obtain a functional additive. The core-shell substrate is composed of ammonium polyphosphate in the core layer and an aluminum hydroxide shell layer coated on its surface.

[0032] The specific operation of the purification process in step 1 is as follows: the reaction product is poured into ice ether for precipitation, the precipitate is washed four times with 85% ethanol aqueous solution and then vacuum-dried at 40°C for 24 hours.

[0033] The preparation method of the aminated core-shell substrate is as follows: ultrasonically disperse the core-shell substrate in an ethanol aqueous solution with a volume concentration of 60% and a pH of 5.5, add 3-aminopropyltriethoxysilane with a mass 0.4 times that of the core-shell substrate, mix well, and react at a temperature of 65°C with stirring for 3 hours; after the reaction is completed, the reaction product is subjected to solid-liquid separation and vacuum drying to obtain the obtained product.

[0034] The preparation method of the core-shell substrate is as follows: dried ammonium polyphosphate is ultrasonically dispersed in a polyethylene glycol aqueous solution at 80°C and with a concentration of 0.5wt% at a dosage ratio of 100g / L, and 18wt% of a urea aqueous solution and 30% of an aluminum sulfate aqueous solution with a concentration of 25wt% are added dropwise to the resulting mixture while stirring, maintaining the pH of the reaction system at 9.2; then, the mixture is stirred and reacted at 70°C for 4h, and then at 85°C for 3h; after the reaction is completed, the reaction product is cooled, washed with water and vacuum dried.

[0035] Comparative Example 1: This comparative example differs from Example 1 in that: in this comparative example, the aluminum hydroxide prepared in Example 1 is used to replace an equal amount of the core-shell substrate, and then the aluminum hydroxide is aminated according to the preparation method of the amination core-shell substrate in Example 1. The obtained amination aluminum hydroxide is then used to prepare the corresponding functional additive according to the preparation method of the functional additive in Example 1; The specific preparation method of aluminum hydroxide is as follows: 13 wt% of a urea aqueous solution and 20% of a 15 wt% of an aluminum sulfate aqueous solution are added dropwise to a 0.3 wt% polyethylene glycol aqueous solution at 65° C. while stirring, and the pH of the reaction system is maintained at 8.5; then, the mixture is stirred and reacted at 65° C. for 4 hours, and then at 75° C. for 5 hours; after the reaction is completed, the reaction product is cooled, washed with water and vacuum dried.

[0036] Comparative Example 2: This comparative example differs from Example 1 in that a core-shell substrate is used in this comparative example to replace an equal amount of functional additives.

[0037] Comparative Example 3: The difference between this comparative example and the embodiment is that ammonium polyphosphate is used in this comparative example to replace an equal amount of functional additives.

[0038] Comparative Example 4: The difference between this comparative example and the embodiment is that in this comparative example, the aluminum hydroxide prepared in Example 1 is used to replace an equal amount of the functional auxiliary agent.

[0039] Performance testing: The soft sheath materials prepared in Examples 1-3 and Comparative Examples 1-4 were made into cable sheaths and their related properties were tested as follows: 1. Flame retardant performance: The vertical burning grade is tested according to UL-94 standard, and the limiting oxygen index (LOI) is measured according to GB / T 2406.

[0040] 2. Mechanical properties: Tensile strength and elongation at break are tested according to GB / T 1040.

[0041] 3. Anti-ultraviolet aging: Based on the QUV accelerated aging test (ASTM G154), using UVB-313 lamps, the test time is 500 hours; The specific test method is as follows: 1. The cable sheaths provided in Examples 1-3 and Comparative Examples 1-4 were made into standard Type I dumbbell specimens (thickness 2±0.1 mm); 2. Place each sample in a QUV aging chamber, set the irradiation intensity to 0.71 W / m² (340nm), the illumination temperature to 60°C, the condensation temperature to 50°C, and the illumination / condensation cycle to 4 hours of illumination + 4 hours of condensation; 3. After aging for 500 hours, remove the samples and condition them in a standard laboratory environment (23±2℃, 50±5%RH) for 24 hours. Then, test the tensile strength after aging according to GB / T 1040 and calculate the tensile strength retention rate. After the experiment, use a colorimeter (with an accuracy of ±0.01ΔEab) to measure the color difference ΔEab of each group of samples before and after aging.

[0042] 4. Smoke density: The maximum smoke density (Dmax) shall be measured according to GB / T 8323.

[0043]

[0044] Comparing and analyzing the relevant data in the table shows that the prepared sheath material not only has excellent mechanical properties and flexibility, but also has outstanding flame retardancy and UV aging resistance, ensuring its quality while also extending its service life to a certain extent. This shows that the flexible cable sheath material and preparation method provided by the present invention have broader market prospects and are more suitable for promotion.

[0045] Throughout this specification, references to terms such as "one embodiment," "example," or "specific example" indicate that the specific features, structures, materials, or characteristics described in conjunction with that embodiment or example are included in at least one embodiment or example of the present invention. In this specification, schematic representations of these terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples.

[0046] The preferred embodiments of the present invention disclosed above are intended only to help illustrate the present invention. These preferred embodiments do not exhaustively describe all details, nor do they limit the present invention to the specific embodiments described. Obviously, many modifications and variations are possible based on the content of this specification. These embodiments are selected and described in detail in this specification to better explain the principles and practical applications of the present invention, thereby enabling those skilled in the art to better understand and utilize the present invention. The present invention is limited only by the claims and their full scope and equivalents.

Claims

1. A soft sheath material for a cable, characterized in that: The following components are included in parts by weight: 30-45 parts of SEBS, 20-30 parts of POE, 15-25 parts of EVA, 15-25 parts of dioctyl sebacate, 5-8 parts of triphenyl phosphate, 1.5-2 parts of silane coupling agent KH-792, 1-1.5 parts of calcium stearate, 8-12 parts of functional additives, 1-1.5 parts of antioxidant, 0.6-1 part of light stabilizer and 8-12 parts of filler; The preparation method of the functional additive is as follows: Step 1: To a 0.4-0.6 mol / L DMF solution of benzo α-pyrone-β-carboxylic acid, add 1.5-2 times the mass of EDC and 0.1-0.2 times the mass of 4-dimethylaminopyridine, respectively, and stir at room temperature for 2-3 hours under nitrogen protection; then add dropwise a 50 wt% cyclohexane hexol phosphate aqueous solution with a mass of 6-10 times the mass of 4-dimethylaminopyridine, and react at a temperature of 35-40° C. for 10-15 hours; after the reaction is completed, purify the reaction product to obtain a modifier; wherein, the pH of the cyclohexane hexol phosphate aqueous solution is adjusted to 5.5-6 with triethylamine before use; Step 2: Add the modifier into deionized water with a mass 15-20 times that of the modifier, adjust the pH to 7.5-8, and then add the resulting mixed component to an aqueous dispersion of the amino core-shell substrate with a volume 6-10 times that of the modifier and a concentration of 10-15wt%. After mixing, heat to 65-70°C and react under nitrogen protection for 8-10 hours. After the reaction is completed, cool the reaction product, centrifuge and wash it, and vacuum dry it to obtain a functional additive. The core-shell substrate is composed of ammonium polyphosphate in the core layer and an aluminum hydroxide shell layer coated on its surface.

2. A soft sheath material for cable according to claim 1, characterized in that: The specific operation of the purification process in step 1 is as follows: the reaction product is poured into ice ether for precipitation, the precipitate is washed 3-4 times with 75-85% ethanol aqueous solution and then vacuum dried at 30-40°C for 24 hours.

3. The soft sheath material for cable according to claim 1, characterized in that: The preparation method of the aminated core-shell substrate is as follows: ultrasonically dispersing the core-shell substrate in an ethanol aqueous solution with a volume concentration of 50-60% and a pH of 4.5-5.5, adding 3-aminopropyltriethoxysilane in an amount 0.3-0.4 times the mass of the core-shell substrate, mixing well, and reacting at a temperature of 55-65°C with stirring for 3-5 hours; after the reaction is completed, the reaction product is subjected to solid-liquid separation and vacuum drying to obtain the product.

4. A soft sheath material for cable according to claim 3, characterized in that: The preparation method of the core-shell substrate comprises: ultrasonically dispersing dried ammonium polyphosphate in a polyethylene glycol aqueous solution at a temperature of 65-80° C. and a concentration of 0.3-0.5 wt% at a dosage ratio of 50-100 g / L; dripping 13-18 wt% of a urea aqueous solution and 20-30% of a 15-25 wt% of an aluminum sulfate aqueous solution into the resulting mixture while stirring, maintaining the pH of the reaction system at 8.5-9.2; then stirring and reacting at 65-80° C. for 2-4 hours, and then reacting at 75-85° C. for 3-5 hours; and after the reaction is completed, cooling, washing with water, and vacuum drying the reaction product to obtain the obtained product.

5. The soft sheath material for cable according to claim 1, characterized in that: The antioxidant is selected from any one of antioxidant 1010, antioxidant 168, and antioxidant 1076.

6. The soft sheath material for cable according to claim 1, characterized in that: The light stabilizer is selected from any one of light stabilizer UV-326 and light stabilizer UV-531.

7. The soft sheath material for cable according to claim 1, characterized in that: The filler is selected from any one of nano calcium carbonate and talcum powder.

8. A method for preparing a soft sheath material for a cable according to any one of claims 1 to 7, characterized in that: The following steps are involved: The first step is to dry SEBS, POE and EVA at a temperature of 80-90°C until the moisture content is less than 0.1%. The dried SEBS, POE, EVA and the remaining raw materials except the functional additives and triphenyl phosphate are put into a high-speed mixer and mixed at a speed of 900-1000 r / min for 10-15 minutes. The obtained premix is ​​stored for future use. The second step is to move the premix into an internal mixer and mix it at a temperature of 120-140°C for 10-15 minutes, then add the remaining raw materials and continue mixing for 5-10 minutes; after the mixing is completed, the obtained mixture is melt-extruded through a twin-screw extruder; finally, it is water-cooled and pelletized to obtain a soft cable sheath material with a length of 3-4 mm.

9. The method for preparing a soft sheath material for a cable according to claim 8, characterized in that: During melt extrusion, the temperatures of each section of the twin-screw extruder are as follows: the temperature of zone 1 is 150-155°C, the temperature of zone 2 is 160-165°C, the temperature of zone 3 is 170-175°C, and the temperature of the die head is 175-180°C.

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