Anti-aging flame-retardant power cable

Abstract

The invention relates to the technical field of power cables, and provides an anti-aging flame-retardant power cable which sequentially comprises a conductor, an insulating layer, an armor layer and a sheath layer from inside to outside, and the sheath layer is prepared from, by weight, 100 parts of linear low-density polyethylene, 2-3 parts of a photoinitiator, 0.2-0.5 part of an antioxidant, 0.03-0.08 part of a light stabilizer, 13-15 parts of a flame retardant and 5-6 parts of filler. The flame retardant comprises the following components in parts by weight: 100 parts of talcum powder loaded zinc stannate and 30-40 parts of magnesium hydroxide. According to the technical scheme, the problems of insufficient flame retardance and aging resistance of the sheath layer in the prior art are solved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of power cable, in particular, it relates to a kind of ageing-resistant flame-retardant power cable. BACKGROUND

[0002] As the core carrier of power transmission and distribution, the safety performance of power cable is directly related to the stable operation of the entire power network and public safety. With the accelerated urbanization process and the continuous growth of power load density in China, the laying environment of power cable is becoming increasingly complex, especially in high-rise buildings, underground space, rail transit and other special application scenarios, so the ageing resistance and flame retardance of power cable have become important technical indicators to ensure personnel safety evacuation and continuous power supply of key facilities. Under this background, the market provides double high requirements for the ageing resistance and flame retardance of power cable.

[0003] At present, most of the cables on the market have certain flame retardance and ageing resistance, but when facing the fire risk of high temperature, flame spread acceleration and other special scenarios such as high load, dense laying and high-rise buildings, underground space, rail transit, the flame retardance and ageing resistance of the cable (the ageing resistance of the sheath layer of power cable can avoid failure caused by sheath failure) will expose obvious short board, which is difficult to meet the core demand of safe operation. Therefore, the development of high ageing-resistant and high flame-retardant power cable has become an urgent need to solve the fire hazard of traditional products and ensure the stable operation of power system, and is also one of the important directions of cable industry technology development. SUMMARY

[0004] The present application provides an ageing-resistant and flame-retardant power cable, which solves the problem of insufficient flame retardance and ageing resistance of the sheath layer in the related art.

[0005] The technical scheme of the present application is as follows: The present application provides an ageing-resistant and flame-retardant power cable, which includes a conductor, an insulation layer, an armour layer and a sheath layer from inside to outside, and the raw material of the sheath layer includes the following components by weight: linear low density polyethylene 100 parts, photoinitiator 2-3 parts, antioxidant 0.2-0.5 parts, light stabilizer 0.03-0.08 parts, flame retardant 13-15 parts, and filler 5-6 parts. The flame retardant includes the following components by weight: talcum powder loaded with zinc stannate 100 parts, magnesium hydroxide 30-40 parts.

[0006] As a further technical scheme, the raw material of the talcum powder loaded with zinc stannate includes talcum powder, sodium stannate, zinc oxide, potassium hydroxide, urea and sodium polyacrylate.

[0007] As a further technical solution, the mass ratio of the talc powder, sodium hydroxystannate, zinc oxide, potassium hydroxide, urea and sodium polyacrylate is 10:1:1:7:10:0.1~0.3, preferably 10:1:1:7:10:0.2.

[0008] In the present application, the mass ratio of the talc powder, sodium hydroxystannate, zinc oxide, potassium hydroxide, urea and sodium polyacrylate is limited to 10:1:1:7:10:0.1~0.3. This specific ratio can ensure that zinc stannate is uniformly loaded on the surface of the talc powder, thereby forming a stable coating structure and improving the flame retardancy of the talc powder loaded with zinc stannate, and further improving the flame retardancy of the sheath layer.

[0009] As a further technical solution, the weight average molecular weight of the sodium polyacrylate is 2400~4300, for example, it can be 2400, 3800 or 4300.

[0010] In the present application, by limiting the molecular weight of the sodium polyacrylate to 2400~4300, a dispersion effect can be achieved during the preparation of the talc powder loaded with zinc stannate, further improving the flame retardancy of the talc powder loaded with zinc stannate. If the molecular weight of the sodium polyacrylate is less than 2400 or greater than 4300, the molecular chain is too short, which can result in insufficient adsorption capacity, and the long molecular chain segments can intertwine, which can reduce the dispersion effect, thereby the phenomenon of talc powder aggregation cannot be fully solved, the precursors of zinc stannate (sodium hydroxystannate, zinc oxide, etc.) cannot fully contact with the talc powder, and the zinc stannate cannot be fully loaded on the talc powder or excessive coating occurs in some areas. When the molecular weight of the sodium polyacrylate is 2400~4300, the zinc stannate can uniformly coat the talc powder, and the flame retardant effect of the zinc stannate can be further improved, thereby further improving the flame retardancy of the sheath layer of the power cable.

[0011] As a further technical solution, the preparation method of the talc powder loaded with zinc stannate comprises the following steps: A1, the talc powder, urea and sodium polyacrylate are added to solvent I and mixed to obtain a mixed solution I; A2, the sodium hydroxystannate, zinc oxide and potassium hydroxide are added to solvent II and mixed, then added to the mixed solution I and mixed, and then filtered, washed, dried and calcined to obtain the talc powder loaded with zinc stannate.

[0012] As a further technical solution, the solvent I and the solvent II are both water.

[0013] As a further technical solution, in step A2, the temperature for mixing with the mixed solution I is 80~90℃, and the mixing time with the mixed solution I is 7~9h.

[0014] As a further technical solution, the photoinitiator includes benzophenone and photoinitiator 1000.

[0015] As a further technical solution, the antioxidant includes one or more of antioxidant 1010, antioxidant 168, antioxidant 1076.

[0016] As a further technical solution, the light stabilizer is a hindered amine light stabilizer, and the hindered amine light stabilizer includes one or both of light stabilizer 770 and light stabilizer 944.

[0017] In the present application, the addition of the hindered amine light stabilizer can effectively improve the light aging resistance of the sheath layer. The hindered amine light stabilizer can capture free radicals generated under ultraviolet irradiation, decompose hydroperoxide, inhibit the photo-oxidative scission of the linear low-density polyethylene molecular chain, reduce the aging phenomena such as cracking, embrittlement, and color change of the sheath layer due to long-term exposure to light, prolong the service life of the cable sheath layer, and ensure the stable operation of the power cable.

[0018] As a further technical solution, the filler includes one or more of carbon black, calcium carbonate, and kaolin.

[0019] The working principle and beneficial effects of the present application are as follows: In the present application, a flame-retardant power cable with aging resistance is provided. The sheath layer of the cable uses talc powder loaded with zinc stannate and magnesium hydroxide as a flame retardant, thereby improving the aging resistance and flame retardance of the cable sheath layer. Zinc stannate is difficult to disperse uniformly in the base material of the sheath layer. The talc powder loaded with zinc stannate uniformly loads zinc stannate on the lamellar structure of the talc powder, which not only solves the problem of zinc stannate agglomeration and poor dispersibility, fully utilizes the flame-retardant effect of zinc stannate, and reduces the application cost of zinc stannate, but also improves the aging resistance of talc powder, thereby achieving simultaneous improvement of flame retardance and aging resistance. In addition, zinc stannate can synergistically promote the formation of coke with magnesium hydroxide. Magnesium oxide produced by the decomposition of magnesium hydroxide at high temperatures can also form an inorganic covering layer, which forms a double barrier with the lamellar structure of talc powder, further blocks the heat transfer and oxygen contact, and improves the flame retardance of the sheath layer. Thus, the safety and service life of the cable in complex environments are comprehensively ensured. DETAILED DESCRIPTION

[0020] The technical solutions in the embodiments of the present application will be clearly and completely described below in combination with the embodiments of the present application. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative labor also fall within the scope of protection of the present application.

[0021] In the following examples and comparative examples: Linear low-density polyethylene, model: FM5220, manufacturer: Borealis Corporation; Carbon black: average particle size 2000 mesh; Talc: average particle size 500 nm; Magnesium hydroxide: average particle size 500 nm; Sodium polyacrylate with a weight average molecular weight of 1400, model: PAA1KBR; manufacturer: Shanghai Zhenzhun Biological Technology Co., Ltd.; Sodium polyacrylate with a weight average molecular weight of 2400, model: PAA3K; manufacturer: Shanghai Zhenzhun Biological Technology Co., Ltd.; Sodium polyacrylate with a weight average molecular weight of 4300, model: PAA4KBR; manufacturer: Shanghai Zhenzhun Biological Technology Co., Ltd.; Sodium polyacrylate with a weight average molecular weight of 5660, model: PAA5K; manufacturer: Shanghai Zhenzhun Biological Technology Co., Ltd.

[0022] Example 1 An aging-resistant flame-retardant power cable comprises a conductor, an insulation layer, an armor layer, and a sheath layer from inside to outside; The raw materials of the sheath layer comprise the following components by weight: 100 parts of linear low-density polyethylene, 0.8 parts of benzophenone, 1.2 parts of photoinitiator 1000, 0.2 parts of antioxidant 1010, 0.03 parts of light stabilizer 770, 13 parts of flame retardant, and 5 parts of carbon black. The flame retardant comprises the following components by weight: 100 parts of talc-loaded zinc stannate and 30 parts of magnesium hydroxide. The preparation method of the talc-loaded zinc stannate comprises the following steps: A1, talc, urea, and sodium polyacrylate with a weight average molecular weight of 5660 are added to water (the mass-volume ratio of talc to water is 1 g:7 mL) and mixed at 50°C for 1 h to obtain a mixed solution I; A2, sodium hydroxystannate, zinc oxide, and potassium hydroxide are added to water (the mass-volume ratio of potassium hydroxide to water is 1 g:6 mL) and mixed, and then the mixed solution I is added and mixed at 85°C for 8 h. After filtration, water washing, and drying, the talc-loaded zinc stannate is obtained by calcining at 600°C for 2 h. The mass ratio of talc, sodium hydroxystannate, zinc oxide, potassium hydroxide, urea, and sodium polyacrylate is 10:1:1:7:10:0.1; A preparation method of an aging-resistant flame-retardant power cable comprises the following steps: S1, the insulation layer material is extruded and wrapped around the conductor to form an insulation layer; S2, the armor layer material is wrapped around the insulation layer to form an armor layer; S3, the raw materials of the sheath layer are uniformly mixed, and then melt-extruded and wrapped around the outside of the armor layer. The sheath layer is formed by ultraviolet light irradiation crosslinking in an ultraviolet light irradiation crosslinking device, and an aging-resistant flame-retardant power cable is obtained. The process parameters of the ultraviolet light irradiation crosslinking are as follows: the ultraviolet light wavelength is 380 nm, and the ultraviolet light intensity is 9.5 W / cm 2 .

[0023] Embodiment 2 An aging-resistant and flame-retardant power cable comprises, from inside to outside, a conductor, an insulation layer, an armored layer, and a sheath layer; The raw materials of the sheath layer comprise the following components in parts by weight: 100 parts of linear low-density polyethylene, 1.2 parts of benzophenone, 1.3 parts of photoinitiator 1000, 0.3 parts of antioxidant 1010, 0.05 parts of light stabilizer 770, 14 parts of a flame retardant, and 5.5 parts of carbon black; the flame retardant comprises the following components in parts by weight: 100 parts of talcum powder loaded zinc stannate, and 35 parts of magnesium hydroxide. The preparation method of the talcum powder loaded zinc stannate comprises the following steps: A1, talcum powder, urea, and sodium polyacrylate with a weight average molecular weight of 5660 are added to water (the mass-volume ratio of the talcum powder to water is 1 g:7 mL) and mixed at 50℃ for 1h to obtain a mixed solution I; A2, sodium stannate, zinc oxide, and potassium hydroxide are added to water (the mass-volume ratio of the potassium hydroxide to water is 1 g:6 mL) and mixed, and then the mixed solution I is added and mixed at 85℃ for 8h, followed by filtration, water washing, drying, and calcination at 600℃ for 2h to obtain the talcum powder loaded zinc stannate, wherein the mass ratio of the talcum powder, sodium hydroxystannate, zinc oxide, potassium hydroxide, urea, and sodium polyacrylate is 10:1:1:7:10:0.2; A preparation method of an aging-resistant and flame-retardant power cable comprises the following steps: S1, the insulation layer material is extruded on the outside of the conductor to form the insulation layer; S2, the armored layer material is wrapped on the outside of the insulation layer to form the armored layer; S3, the raw materials of the sheath layer are uniformly mixed, and then melt-extruded to coat the outside of the armored layer, and then placed in an ultraviolet light irradiation crosslinking device to perform ultraviolet light irradiation crosslinking to form the sheath layer, thereby obtaining the aging-resistant and flame-retardant power cable; The process parameters of the ultraviolet light irradiation crosslinking are as follows: the ultraviolet light wavelength is 380 nm, and the ultraviolet light intensity is 9.5 W / cm 2 .

[0024] Embodiment 3 An anti-aging flame-retardant power cable comprises a conductor, an insulation layer, an armor layer and a sheath layer from inside to outside, and the raw material of the sheath layer comprises the following components in parts by weight: 100 parts of linear low-density polyethylene, 1.3 parts of benzophenone, 1.7 parts of photoinitiator 1000, 0.5 parts of antioxidant 1010, 0.08 parts of light stabilizer 770, 15 parts of flame retardant, and 6 parts of carbon black; the flame retardant comprises the following components in parts by weight: 100 parts of talcum powder loaded zinc stannate and 40 parts of magnesium hydroxide. The preparation method of the talcum powder loaded zinc stannate comprises the following steps: A1, talcum powder, urea and sodium polyacrylate with a weight average molecular weight of 5660 are added into water (the mass-volume ratio of talcum powder to water is 1g:7mL) and mixed at 50℃ for 1h to obtain a mixed solution I; A2, sodium hydroxystannate, zinc oxide and potassium hydroxide are added into water (the mass-volume ratio of potassium hydroxide to water is 1g:6mL) and mixed, and then the mixed solution I is added and mixed at 85℃ for 8h, and then talcum powder loaded zinc stannate is obtained by filtration, water washing, drying and calcination at 600℃ for 2h, wherein the mass ratio of talcum powder, sodium hydroxystannate, zinc oxide, potassium hydroxide, urea and sodium polyacrylate is 10:1:1:7:10:0.3; A preparation method of an anti-aging flame-retardant power cable comprises the following steps: S1, an insulation layer material is extruded on the outside of the insulation layer to form the insulation layer; S2, an armor layer material is wrapped on the outside of the insulation layer to form the armor layer; S3, the raw material of the sheath layer is uniformly mixed and then melt-extruded to coat the outside of the armor layer, and then the sheath layer is formed by ultraviolet light irradiation crosslinking in an ultraviolet light irradiation crosslinking device to obtain the anti-aging flame-retardant power cable; The process parameters of the ultraviolet light irradiation crosslinking are as follows: the wavelength of the ultraviolet light is 380nm, and the intensity of the ultraviolet light is 9.5W / cm 2 .

[0025] Example 4 The difference between this example and Example 2 is that the amount of magnesium hydroxide added in this example is 35 parts.

[0026] Example 5 The difference between this example and Example 2 is that the amount of magnesium hydroxide added in this example is 40 parts.

[0027] Example 6 The difference between this example and Example 2 is that no sodium polyacrylate is added in this example.

[0028] Example 7 The difference between this example and example 2 is only that the sodium polyacrylate in this example has a weight average molecular weight of 1400.

[0029] Example 8 The difference between this example and example 7 is only that the sodium polyacrylate in this example has a weight average molecular weight of 4300.

[0030] Example 9 The difference between this example and example 7 is only that the sodium polyacrylate in this example has a weight average molecular weight of 2400.

[0031] Comparative Example 1 The difference between this comparative example and example 2 is only that the talcum powder loaded zinc stannate in this comparative example is replaced by an equal amount of magnesium hydroxide.

[0032] Comparative Example 2 The difference between this comparative example and example 2 is only that the magnesium hydroxide in this comparative example is replaced by an equal amount of talcum powder loaded zinc stannate.

[0033] Comparative Example 3 The difference between this comparative example and example 6 is only that the talcum powder loaded zinc stannate in this comparative example is replaced by an equal amount of zinc stannate composite talcum powder, and the preparation method of the zinc stannate composite talcum powder comprises the following steps: A1, urea, sodium stannate, zinc oxide and potassium hydroxide are added to water and mixed at 85℃ for 8h, then filtered, dried, and calcined at 600℃ for 2h to obtain zinc stannate; A2, the zinc stannate and talcum powder are mixed to obtain zinc stannate composite talcum powder; The mass ratio of talcum powder, sodium stannate, zinc oxide, potassium hydroxide and urea is 10:1:1:7:10.

[0034] Test Example 1 The sheath layer of the aging-resistant flame-retardant power cable prepared in examples 1-9 and comparative examples 1-3 is tested according to the following method: Flame-retardant performance: test the oxygen index according to method A of GB / T 2406.2-2009 "Plastics-Determination of the burning behavior in terms of flame spread-Part 2: 50mm test with 10mm sample thickness", and the sample shape is IV, and the test results are shown in Table 1 and Table 2.

[0035] Table 1 Performance test results of examples 1-6 and comparative examples 1-3

[0036] The oxygen index of examples 1-6 is higher than that of comparative examples 1-3, which indicates that the addition of talcum powder loaded zinc stannate and magnesium hydroxide composite as a flame retardant in the sheath layer improves the flame retardance of the sheath layer.

[0037] Table 2 Performance test results of example 2 and examples 7-9

[0038] The oxygen index of examples 8-9 is higher than that of example 2 and example 7, which indicates that the present application further improves the flame retardance of the sheath layer by limiting the molecular weight of sodium polyacrylate to 2400-4300.

[0039] Test example 2 The sheath layer of the aging-resistant flame-retardant power cable prepared in examples 1-3 is tested according to the following method: Mechanical property: the tensile strength test is performed according to the method of GB / T 2951.11-2008 "Cables and optical cables - General test methods - Part 11: General test methods - Measurement of thickness and outer dimensions - Mechanical property tests", the test sample is a dumbbell sample, the thickness is 1.5 mm, and the moving speed is 25 mm / min; the heat aging test is performed according to GB / T 7141 2008 "Plastics - Determination of the effect of heat on the mechanical properties of thermoplastics - Part 1: General test method", and then the tensile strength test after heat aging test is performed according to the above tensile strength test method; wherein the heat aging test is performed by method B, the temperature is 90℃, and the time is 128h, and the test results are shown in Table 3.

[0040] Table 3 Performance test results of examples 1-3

[0041] It can be seen from examples 1-3 in Table 3 that the sheath layer in the present application has good heat aging resistance.

[0042] The above is only a preferred embodiment of the present application, and is not used to limit the present application, any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. An aging-resistant and flame-retardant power cable, characterized in that, From the inside out, it includes a conductor, an insulating layer, an armor layer, and a sheath layer. The raw materials of the sheath layer include the following components by weight: 100 parts linear low-density polyethylene, 2-3 parts photoinitiator, 0.2-0.5 parts antioxidant, 0.03-0.08 parts light stabilizer, 13-15 parts flame retardant, and 5-6 parts filler. The flame retardant includes the following components by weight: 100 parts talc-supported zinc stannate and 30-40 parts magnesium hydroxide.

2. The aging-resistant and flame-retardant power cable according to claim 1, characterized in that, The raw materials for the talc-loaded zinc stannate include talc, sodium hydroxystannate, zinc oxide, potassium hydroxide, urea, and sodium polyacrylate.

3. The aging-resistant and flame-retardant power cable according to claim 2, characterized in that, The mass ratio of talc, sodium hydroxystannate, zinc oxide, potassium hydroxide, urea, and sodium polyacrylate is 10:1:1:7:10:0.1~0.

3.

4. The aging-resistant and flame-retardant power cable according to claim 3, characterized in that, The sodium polyacrylate has a weight-average molecular weight of 2400-4300.

5. The aging-resistant and flame-retardant power cable according to claim 2, characterized in that, The preparation method of the talc-supported zinc stannate includes the following steps: A1. The talc powder, urea and sodium polyacrylate are added to solvent I and mixed to obtain mixture I; A2. The sodium stannate, zinc oxide and potassium hydroxide are added to solvent II and mixed. Then, mixture I is added and mixed. After filtration, washing, drying and calcination, talc-supported zinc stannate is obtained.

6. The aging-resistant and flame-retardant power cable according to claim 5, characterized in that, In step A2, the temperature at which the added mixture I is mixed is 80~90℃, and the mixing time of the added mixture I is 7~9h.

7. The aging-resistant and flame-retardant power cable according to claim 1, characterized in that, The photoinitiator includes benzophenone and photoinitiator 1000.

8. The aging-resistant and flame-retardant power cable according to claim 1, characterized in that, The antioxidant includes one or more of antioxidant 1010, antioxidant 168, and antioxidant 1076.

9. The aging-resistant and flame-retardant power cable according to claim 1, characterized in that, The light stabilizer is a hindered amine light stabilizer, which includes one or two of light stabilizer 770 and light stabilizer 944.

10. The aging-resistant and flame-retardant power cable according to claim 1, characterized in that, The filler includes one or more of carbon black, calcium carbonate, and kaolin.

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