Anti-cracking flame-retardant sheath material, preparation method thereof, and electric wire

Abstract

The present invention relates to the technical field of wires and cables, specifically disclosing a crack-resistant flame-retardant sheathing material, a preparation method thereof, and an electric wire. The crack-resistant flame-retardant sheathing material comprises 90-120 parts of PVC resin, 20-25 parts of filler, 18-24 parts of plasticizer, 9-12 parts of a ternary flame retardant, 10-15 parts of an antioxidant, and 5-8 parts of a thermal stabilizer. The ternary flame retardant is a compound of aluminum hydroxide, potassium hexahydroxyantimonate, and ammonium bicarbonate in a mass ratio of (5-6):(1-2):(3-4). The preparation method of the crack-resistant flame-retardant sheathing material comprises mixing the components, performing banburying, and extruding granulation. An electric wire employs the crack-resistant flame-retardant sheathing material of the present application as the sheathing material. The present application ensures that the crack-resistant flame-retardant sheathing material has good mechanical properties while achieving excellent flame retardancy and smoke suppression.

Description

Technical Field

[0001] The present invention relates to the technical field of electric wires and cables, and in particular to an anti-cracking flame-retardant sheath material, a preparation method thereof, and an electric wire. Background Art

[0002] At present, with the gradual strengthening of informatization construction, the market demand for flame-retardant cables is increasing. The flame retardancy of cables mainly involves the examination of the toxicity of smoke generated by the combustion of cables and the self-extinguishing performance of cables after ignition. Among them, the flame retardancy of the sheath material is crucial to the flame retardancy of the cables.

[0003] PVC, the most widely used sheathing material, offers excellent properties such as low cost, lightweight, and oil and fire resistance. However, PVC also contains a large amount of chlorine, which produces large amounts of toxic black smoke during combustion and pyrolysis. In a fire scene, this toxic black smoke is highly likely to endanger people's safety and cause serious harm to the human body.

[0004] Prior art generally suppresses the black smoke produced by PVC resin during combustion by adding an appropriate amount of inorganic flame retardants to the PVC material. Inorganic flame retardants not only accelerate the formation of a char layer in the sheathing material, physically isolating it to achieve a flame retardant effect, but also effectively reduce the amount of black smoke and soot produced, minimizing the harm of toxic black smoke to the human body. While adding an appropriate amount of inorganic flame retardants to PVC materials can achieve both non-toxic smoke suppression and flame retardancy, the flame retardant effect achieved by this method is closely related to the amount of inorganic flame retardant added. Only when a certain amount of inorganic flame retardant is added can a good flame retardant effect be achieved.

[0005] As the filling amount of inorganic flame retardants increases, the impact on the apparent properties and microstructure of PVC materials will become increasingly greater. The more polymer molecular chains in the PVC material are physically separated by the inorganic flame retardants, the less entanglement there is between the polymer molecular chains in the PVC material, which directly leads to a significant reduction in the mechanical properties of the PVC material and a significant reduction in the crack resistance of the PVC material. In order to ensure certain mechanical properties of the PVC material, the amount of inorganic flame retardants added will be strictly controlled, but this may result in an insufficient amount of inorganic flame retardants added, resulting in an insignificant improvement in the flame retardant effect of the PVC material. In view of the above-mentioned related technologies, the inventors believe that it is necessary to further improve the inorganic flame retardants to ensure that a sheath material with a good flame retardant effect can be obtained even with a smaller amount of inorganic flame retardants added. Summary of the Invention

[0006] To enhance the crack resistance of sheath materials, the present application provides a crack-resistant flame-retardant sheath material, a preparation method thereof, and an electric wire. This application adds a ternary flame retardant compounded from aluminum hydroxide, ammonium bicarbonate, and potassium hexahydroxyantimonate to the crack-resistant flame-retardant sheath material. Through the synergistic effect of aluminum hydroxide, ammonium bicarbonate, and potassium hexahydroxyantimonate, the crack-resistant flame-retardant sheath material maintains a good flame retardant effect while maintaining good crack resistance.

[0007] In the first aspect, the present application provides a crack-resistant flame-retardant sheath material using the following technical solution:

[0008] A crack-resistant flame-retardant sheath material, comprising the following components in parts by mass:

[0009]

[0010] The ternary flame retardant is a compound of aluminum hydroxide, ammonium bicarbonate and potassium hexahydroxyantimonate.

[0011] The mass ratio of the aluminum hydroxide, ammonium bicarbonate and potassium hexahydroxyantimonate is (5-6): (1-2): (3-4).

[0012] In the above technical solution, aluminum hydroxide has a certain effect of improving the oxygen index of the anti-cracking flame retardant sheath material and suppressing smoke. At the same time, the compatibility of aluminum hydroxide and PVC resin is poor. Therefore, the amount of aluminum hydroxide added needs to be strictly controlled to reduce the negative impact of aluminum hydroxide on the mechanical properties of PVC resin; ammonium bicarbonate undergoes an endothermic reaction during the combustion and pyrolysis process to produce ammonia and carbon dioxide to dilute the oxygen concentration of the air, thereby effectively slowing down the combustion speed; potassium hexahydroxyantimonate can reduce the combustion temperature during the combustion and pyrolysis process of the anti-cracking flame retardant sheath material, promote the generation of carbon to physically isolate the combustion, and avoid further combustion of the anti-cracking flame retardant sheath material. The present application found in the study that when aluminum hydroxide, ammonium bicarbonate and potassium hexahydroxyantimonate are compounded in a mass ratio of (5-6): (1-2): (3-4), aluminum hydroxide, ammonium bicarbonate and potassium hexahydroxyantimonate can play a significant synergistic role, ensuring good mechanical properties of the anti-cracking flame retardant sheath material while achieving good flame retardant and smoke suppression effects.

[0013] Preferably, the plasticizer is a compound of polypropylene adipate and tricresyl phosphate, wherein the polypropylene adipate accounts for 15 to 18 parts by mass of the anti-cracking flame retardant sheath material; the tricresyl phosphate accounts for 3 to 6 parts by mass of the anti-cracking flame retardant sheath material.

[0014] In the above technical scheme, by adding a plasticizer prepared by polypropylene adipate and tricresyl phosphate to the anti-cracking flame retardant sheath material, not only the interfacial bonding strength between the components in the anti-cracking flame retardant sheath material can be improved, but also the negative impact of the addition of the plasticizer on the oxygen index of the anti-cracking flame retardant sheath material can be significantly reduced. The anti-cracking flame retardant sheath material has a higher oxygen index while maintaining good anti-cracking performance. When it is combined with aluminum hydroxide, ammonium bicarbonate and potassium hexahydroxyantimonate in a mass ratio of (5-6): (1-2): (3-4), the negative impact of aluminum hydroxide on the mechanical properties of the anti-cracking flame retardant sheath material is significantly improved, and the smoke suppression effect of aluminum hydroxide, ammonium bicarbonate and potassium hexahydroxyantimonate is enhanced.

[0015] Preferably, the filler is calcium carbonate.

[0016] In the above technical solution, by selecting calcium carbonate as the filler of the anti-cracking flame-retardant sheath material, the mechanical properties of the anti-cracking flame-retardant sheath material can be further improved. Calcium carbonate is compounded with aluminum hydroxide, ammonium bicarbonate, and potassium hexahydroxyantimonate in a mass ratio of (5-6): (1-2): (3-4), which further improves the flame retardancy of the anti-cracking flame-retardant sheath material, promotes the generation of a carbon layer and carbon dioxide when the anti-cracking flame-retardant sheath material burns, and inhibits further combustion of the anti-cracking flame-retardant sheath material.

[0017] Preferably, the antioxidant is phosphite.

[0018] In the above technical solution, by selecting phosphite as the antioxidant of the anti-cracking flame retardant sheath material, the aging resistance of the anti-cracking flame retardant sheath material is further improved, and the service life of the anti-cracking flame retardant sheath material is extended.

[0019] Preferably, the heat stabilizer is a calcium zinc PVC heat stabilizer.

[0020] In the above technical solution, by selecting calcium zinc PVC heat stabilizer as the heat stabilizer of the anti-cracking flame retardant sheath material, the processing stability of the anti-cracking flame retardant sheath material is further improved, the high temperature resistance of the anti-cracking flame retardant sheath material is improved, and the service life of the anti-cracking flame retardant sheath material is further extended.

[0021] In a second aspect, the present application provides a method for preparing a crack-resistant flame-retardant sheath material using the following technical solution:

[0022] A method for preparing a crack-resistant flame-retardant sheath material comprises the following steps:

[0023] Step 1: Mix PVC resin, filler, plasticizer, ternary flame retardant, antioxidant and heat stabilizer under high-speed stirring to obtain a mixture;

[0024] Step 2: After the mixture is kneaded at 130-140° C. for 20-30 minutes, it is extruded and granulated to obtain a crack-resistant flame-retardant sheath material.

[0025] In the above technical solution, the anti-cracking flame-retardant sheath material can be obtained by first mixing the components of the anti-cracking flame-retardant sheath material and then mixing and granulating. The preparation method is simple, efficient and easy to industrialize.

[0026] In a third aspect, the present application provides a wire adopting the following technical solution:

[0027] An electric wire comprises the anti-cracking flame-retardant sheath material of the present application.

[0028] In the above technical solution, by using the anti-cracking and flame-retardant sheath material of the present application on the electric wire, the anti-cracking effect and flame-retardant effect of the electric wire are further improved.

[0029] Preferably, the electric wire comprises a cable core, an inner cladding, a heat-insulating filler and an outer sheath from the inside to the outside. The cable core comprises a conductor and an inner cladding. The inner cladding is formed by wrapping a layer of soft ceramic tape around the outer surface of the conductor.

[0030] In the above technical solution, the electric wire includes a cable core, an inner sheath, a thermal insulation filler, and an outer sheath from the inside to the outside. The inner sheath is formed by wrapping a layer of soft ceramic fiber tape on the outer surface of the conductor, which further enhances the overall flame retardant effect of the electric wire.

[0031] In summary, this application includes at least one of the following beneficial technical effects:

[0032] 1. When aluminum hydroxide, ammonium bicarbonate and potassium hexahydroxyantimonate are compounded in a mass ratio of (5-6): (1-2): (3-4) in this application, aluminum hydroxide, ammonium bicarbonate and potassium hexahydroxyantimonate can exert a significant synergistic effect, while ensuring good mechanical properties of the anti-cracking flame-retardant sheath material, achieving good flame retardant and smoke suppression effects.

[0033] 2. The present application adds a plasticizer formed by polypropylene adipate and tricresyl phosphate to the anti-cracking flame retardant sheath material, which not only improves the interfacial bonding strength between the components in the anti-cracking flame retardant sheath material, but also significantly reduces the negative impact of the addition of the plasticizer on the oxygen index of the anti-cracking flame retardant sheath material. The anti-cracking flame retardant sheath material has a higher oxygen index while maintaining good anti-cracking performance. When aluminum hydroxide, ammonium bicarbonate and potassium hexahydroxyantimonate are compounded in a mass ratio of (5-6): (1-2): (3-4), the negative impact of aluminum hydroxide on the mechanical properties of the anti-cracking flame retardant sheath material is significantly improved, and the smoke suppression effect of aluminum hydroxide, ammonium bicarbonate and potassium hexahydroxyantimonate is enhanced.

[0034] 3. This application selects calcium carbonate as a filler for the anti-cracking flame-retardant sheath material, which can further improve the mechanical properties of the anti-cracking flame-retardant sheath material. Calcium carbonate is compounded with aluminum hydroxide, ammonium bicarbonate, and potassium hexahydroxyantimonate in a mass ratio of (5-6): (1-2): (3-4), which further improves the flame retardancy of the anti-cracking flame-retardant sheath material, promotes the generation of carbon layer and carbon dioxide when the anti-cracking flame-retardant sheath material burns, and inhibits further combustion of the anti-cracking flame-retardant sheath material. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] Figure 1 This is a schematic diagram of the structure of an electric wire.

[0036] Description of reference numerals:

[0037] 1. Cable core; 2. Inner cladding; 3. Thermal insulation filler; 4. Outer sheath. DETAILED DESCRIPTION

[0038] In order to better illustrate the purpose, technical solutions and advantages of the present invention, the present invention will be further described below in conjunction with specific embodiments.

[0039] Examples 1-5

[0040] The invention discloses a crack-resistant flame-retardant sheath material, comprising PVC resin, a filler, a plasticizer, a ternary flame retardant, an antioxidant, and a heat stabilizer.

[0041] The specific amount of each component is shown in Table 1.

[0042] Table 1:

[0043]

[0044]

[0045] Among them, calcium carbonate was purchased from Guangzhou Yongzheng Chemical Co., Ltd., light calcium carbonate.

[0046] Among them, the CAS number of polypropylene adipate is 25101-03-5.

[0047] Among them, the CAS number of tricresyl phosphate is 25155-23-1.

[0048] Among them, aluminum hydroxide was purchased from Guangzhou Yifeng Chemical Technology Co., Ltd., model TY-420.

[0049] Among them, the CAS number of ammonium bicarbonate is 1066-33-7.

[0050] Among them, the CAS number of potassium hexahydroxyantimonate is 12208-13-8.

[0051] Among them, phosphite was purchased from Shandong Xinwei Chemical Technology Co., Ltd. with a CAS number of 31570-04-4.

[0052] Among them, calcium zinc PVC heat stabilizer was purchased from Guangzhou Xingsheng Trading Co., Ltd. with CAS number 4164-46.

[0053] The preparation method of the anti-cracking flame-retardant sheath material comprises the following steps:

[0054] Step 1: Stir PVC resin, filler, plasticizer, ternary flame retardant, antioxidant, and heat stabilizer at a high-speed stirring speed of 1000 r / min for 5 minutes to obtain a mixture.

[0055] Step 2: Add the mixture into an internal mixer, mix it at 130° C. for 20 minutes, and then put it into an extrusion equipment for extrusion and granulation to obtain a crack-resistant flame-retardant sheath material.

[0056] Example 6

[0057] A crack-resistant flame-retardant sheath material, which is different from Example 5 in that the added amount of polypropylene adipate is adjusted to 15 kg.

[0058] Example 7

[0059] A crack-resistant flame-retardant sheath material, which is different from Example 5 in that the added amount of tricresyl phosphate is adjusted to 15 kg.

[0060] Comparative Example 1

[0061] A sheath material, which is different from Example 3 in that it does not contain aluminum hydroxide.

[0062] Comparative Example 2

[0063] A sheath material, which is different from Example 3 in that it does not contain potassium hexahydroxyantimonate.

[0064] Comparative Example 3

[0065] A sheath material, which is different from Example 3 in that it does not contain ammonium bicarbonate.

[0066] Comparative Example 4

[0067] A sheath material, which is different from Example 3 in that the added amount of aluminum hydroxide is adjusted to 4 kg.

[0068] Comparative Example 5

[0069] A sheath material, which is different from Example 3 in that the added amount of aluminum hydroxide is adjusted to 8 kg.

[0070] Comparative Example 6

[0071] A sheath material, which is different from Example 3 in that the amount of ammonium bicarbonate added is adjusted to 0.5 kg.

[0072] Comparative Example 7

[0073] A sheath material, which is different from Example 3 in that the amount of ammonium bicarbonate added is adjusted to 3 kg.

[0074] Comparative Example 8

[0075] A sheath material, which is different from Example 3 in that the added amount of potassium hexahydroxyantimonate is adjusted to 2 kg.

[0076] Comparative Example 9

[0077] A sheath material, which is different from Example 3 in that the added amount of potassium hexahydroxyantimonate is adjusted to 5 kg.

[0078] Application Example 1

[0079] A wire, such as Figure 1 As shown, the electric wire includes a cable core 1, an inner cladding 2, a heat-insulating filler 3, and an outer sheath 4 from the inside to the outside.

[0080] The cable core 1 includes a conductor and an inner wrapping layer, and the inner wrapping layer is formed by wrapping a layer of soft ceramic fiber tape on the outer surface of the conductor.

[0081] The outer sheath may be the anti-cracking flame-retardant sheath material prepared from any one of Examples 1-7.

[0082] Performance test of sheath material:

[0083] Sample: the sheath materials of Examples 1-7 and Comparative Examples 1-9.

[0084] Test 1: Tensile properties test

[0085] Tests were conducted according to GB / T 1040.1-2018 using a universal electronic tensile testing machine. Samples were placed horizontally at 25°C ± 0.5°C for 24 hours before stretching. Tensile tests were performed at 25°C ± 0.5°C. The tensile rate was 200 mm / min, and the sample thickness was 1 mm. The tensile strength and elongation at break were recorded.

[0086] The tensile strength refers to the maximum tensile stress (MPa) to which the sample is subjected until it breaks, and the elongation at break refers to the ratio of the displacement value of the sample at break to the original length, expressed as a percentage (%).

[0087] Test 2: Oxygen Index

[0088] Test according to GB / T2406-1993. Sample size is 100mm*6.5mm*3mm.

[0089] Test 3: Smoke Density

[0090] Tested in accordance with GB / T8323.2-2008. Sample size: 75mm*75mm*25mm, 25kW / m 2 The smoke density is tested under certain conditions.

[0091] The test results are shown in Table 2.

[0092] Table 2:

[0093]

[0094]

[0095]

[0096] In combination with Examples 1-7, Comparative Examples 1-9 and Table 2, it can be seen that Examples 1-7 have good tensile strength, elongation at break, oxygen index and smoke density. Furthermore, the anti-cracking flame-retardant sheath materials of Examples 1-7 have good flame retardant and smoke suppression effects while having good mechanical properties.

[0097] Combining Example 3 and Comparative Examples 1-3 and Table 2, it can be seen that the comprehensive performance of the sheath material of Example 3 is good. The sheath material of Example 3 has good mechanical properties and good flame retardant and smoke suppression effects. Comparative Example 1 does not add aluminum hydroxide, and the mechanical properties of Comparative Example 1 are better than those of Example 3 to a certain extent, while the flame retardant and smoke suppression effects are not as good as those of Example 3 to a certain extent; Comparative Example 2 does not add ammonium bicarbonate, and the mechanical properties and flame retardant and smoke suppression effects of Comparative Example 2 are not as good as those of Example 3 to a certain extent; Comparative Example 3 does not add potassium hexahydroxyantimonate, and the mechanical properties and flame retardant and smoke suppression effects of Comparative Example 3 are not as good as those of Example 3 to a certain extent; From this analysis, it can be concluded that the ternary flame retardant composed of aluminum hydroxide, ammonium bicarbonate and potassium hexahydroxyantimonate can exert a significant synergistic effect, ensuring good mechanical properties of the anti-cracking flame retardant sheath material while achieving good flame retardant and smoke suppression effects.

[0098] Combining Example 3 and Comparative Examples 4-9 and Table 2, it can be seen that the sheath material of Example 3 has good mechanical properties and good flame retardant and smoke suppression effects. Specifically, the difference between Comparative Example 4-5 and Example 3 is that the amount of aluminum hydroxide added in Comparative Example 4-5 is not within the range of 5 to 6 parts, and the sheath material of Comparative Example 4-5 cannot achieve good flame retardant and smoke suppression effects while ensuring good mechanical properties of the anti-cracking flame retardant sheath material; the difference between Comparative Example 6-7 and Example 3 is that the amount of ammonium bicarbonate added in Comparative Example 6-7 is not within the range of 1 to 2 parts, and Comparative Example 6 has good smoke suppression compared to Example 3 but does not have good flame retardant effects, and Comparative Example 7 has good flame retardant effects compared to Example 3 but does not It has good smoke suppression properties; the difference between Comparative Examples 8-9 and Example 3 is that the addition amount of potassium hexahydroxyantimonate in Comparative Examples 8-9 is not within the range of 3 to 4 parts, the flame retardant effect of Comparative Example 8 is improved to a certain extent compared with Example 3, but the smoke suppression is reduced to a certain extent, and the flame retardant effect of Comparative Example 9 is reduced to a certain extent compared with Example 3, and the smoke suppression is reduced to a certain extent; from this analysis, it can be concluded that only when aluminum hydroxide, ammonium bicarbonate and potassium hexahydroxyantimonate are compounded in a mass ratio of (5 to 6): (1 to 2): (3 to 4), aluminum hydroxide, ammonium bicarbonate and potassium hexahydroxyantimonate can exert a significant synergistic effect, ensuring good mechanical properties of the anti-cracking flame retardant sheath material while achieving good flame retardant and smoke suppression effects.

[0099] Combining Example 5 with Examples 3-4 and Table 2, it can be seen that Example 5 has better flame retardant and smoke suppression effects, and Example 5 further balances the mechanical properties and flame retardant and smoke suppression effects of the anti-cracking flame retardant sheath material; specific analysis shows that adding a plasticizer composed of polypropylene adipate and tricresyl phosphate to the anti-cracking flame retardant sheath material can not only improve the interfacial bonding force between the components in the anti-cracking flame retardant sheath material, but also significantly reduce the negative impact of the addition of the plasticizer on the oxygen index of the anti-cracking flame retardant sheath material. When aluminum hydroxide, ammonium bicarbonate and potassium hexahydroxyantimonate are compounded in a mass ratio of (5-6): (1-2): (3-4), the negative impact of aluminum hydroxide on the mechanical properties of the anti-cracking flame retardant sheath material can be further improved, and the smoke suppression effect of aluminum hydroxide, ammonium bicarbonate and potassium hexahydroxyantimonate can be enhanced.

[0100] This specific embodiment is merely an explanation of the present application and is not a limitation of the present application. After reading this specification, those skilled in the art may make non-creative modifications to the present embodiment as needed, but as long as they are within the scope of the claims of the present application, they are protected by the patent law.

Claims

1. A crack-resistant flame-retardant sheath material, characterized in that: Calculated by mass percentage of the anti-cracking flame retardant sheath material, it includes the following components: PVC resin: 90~120 parts; Filler: 20~25 parts; Plasticizer: 18-24 parts; Ternary flame retardant: 9~12 parts; Antioxidant: 10-15 parts; Heat stabilizer: 5~8 parts; The ternary flame retardant is a compound of aluminum hydroxide, potassium hexahydroxyantimonate and ammonium bicarbonate. The mass ratio of the aluminum hydroxide, ammonium bicarbonate and potassium hexahydroxyantimonate is (5-6): (1-2): (3-4); The plasticizer is a compound of polypropylene adipate and tricresyl phosphate, wherein the mass fraction of the polypropylene adipate is 15 to 18 parts; the mass fraction of the tricresyl phosphate is 3 to 6 parts; The filler is calcium carbonate.

2. The anti-cracking flame-retardant sheath material according to claim 1, characterized in that: The antioxidant is phosphite.

3. The anti-cracking flame-retardant sheath material according to claim 1, characterized in that: The heat stabilizer is a calcium zinc PVC heat stabilizer.

4. A method for preparing the anti-cracking flame-retardant sheath material according to any one of claims 1 to 3, characterized in that: The following steps are involved: Step 1: Mix PVC resin, filler, plasticizer, ternary flame retardant, antioxidant and heat stabilizer under high-speed stirring to obtain a mixture; Step 2: After the mixture is kneaded at 130-140°C for 20-30 minutes, it is extruded and granulated to obtain a crack-resistant flame-retardant sheath material.

5. An electric wire, characterized in that: The electric wire comprises the anti-cracking flame-retardant sheath material according to any one of claims 1 to 3.

6. The electric wire according to claim 5, characterized in that: The electric wire comprises a cable core, an inner sheath, a heat insulating filler and an outer sheath from the inside to the outside. The cable core comprises a conductor and an inner sheath. The inner sheath is formed by wrapping a layer of soft ceramic fiber tape around the outer surface of the conductor.

Images