Aluminum alloy core fireproof cable and preparation process thereof

Abstract

The application relates to the technical field of fireproof cables, and discloses an aluminum alloy core fireproof cable and a preparation process thereof. The aluminum alloy core fireproof cable comprises, from inside to outside, a conductor, an insulation layer, a filling layer, a bundling heat insulation layer, an isolation layer, a fireproof layer and a sheath layer. The sheath layer comprises the following components by weight: 100 parts of polyvinyl chloride, 10 to 15 parts of a plasticizer, 10 to 15 parts of ethylene-vinyl acetate copolymer, 25 to 30 parts of a flame retardant, 0.5 to 1.5 parts of an antioxidant, 10 to 20 parts of a filler, and 0.5 to 1 part of a lubricant. The preparation method of the flame retardant comprises the following steps: mixing calcium oxide, magnesium oxide and zinc oxide, and obtaining a solid solution after solid solution annealing; mixing the solid solution with aluminum hydroxide, ammonium polyphosphate and a metal acetylacetone complex to obtain the flame retardant. Through the technical scheme, the problem of insufficient fire resistance of the fireproof cable in the related art is solved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of fireproof cable, in particular to an aluminum alloy core fireproof cable and a preparation process thereof. BACKGROUND

[0002] As a key component to ensure power transmission under extreme conditions such as fire, fireproof cable is widely used. Although there are various types of fireproof cables on the market, many problems still exist in practical applications. In terms of flame retardant performance, some fireproof cables cannot meet the increasingly stringent safety standards.

[0003] Polyvinyl chloride is widely used in the sheath layer of fireproof cable due to its inherent flame retardant properties. However, polyvinyl chloride has poor stability at high temperatures. When the temperature is too high, polyvinyl chloride will rapidly decompose, releasing a large amount of smoke and diene hydrocarbons containing double bonds. Diene hydrocarbons containing double bonds are highly flammable substances that can significantly increase the speed of flame spread, severely affecting the flame retardant performance of fireproof cable. Moreover, the generated smoke can also have a strong irritation to the respiratory system of the human body, affecting personnel evacuation and rescue work.

[0004] Therefore, it is necessary to develop an aluminum alloy core fireproof cable with better flame retardant performance. SUMMARY

[0005] The present application provides an aluminum alloy core fireproof cable and a preparation process thereof, which solves the problem of insufficient flame retardant performance of fireproof cable in related technologies.

[0006] The technical scheme of the present application is as follows: The present application provides an aluminum alloy core fireproof cable, which comprises a conductor, an insulation layer, a filling layer, a bundling heat insulation layer, an isolation layer, a fireproof layer, and a sheath layer arranged in order from the inside to the outside. The sheath layer comprises the following components by weight: polyvinyl chloride 100 parts, plasticizer 10-15 parts, ethylene-vinyl acetate copolymer 10-15 parts, flame retardant 25-30 parts, antioxidant 0.5-1.5 parts, filler 10-20 parts, and lubricant 0.5-1 part. The preparation method of the flame retardant comprises the following steps: mixing calcium oxide, magnesium oxide, and zinc oxide, and obtaining a solid solution after solid solution annealing; mixing the solid solution with aluminum hydroxide, ammonium polyphosphate, and metal acetylacetone complex to obtain a flame retardant.

[0007] As a further technical scheme, the solid solution annealing temperature is 500-550℃, for example, it can be 500℃, 510℃, 520℃, 530℃, 540℃, or 550℃, preferably 500℃, and the time is 8-9h, for example, it can be 8h, 8.1h, 8.2h, 8.3h, 8.4h, 8.5h, 8.6h, 8.7h, 8.8h, 8.9h, or 9h, preferably 8h.

[0008] As a further technical solution, the material of the conductor is aluminum alloy.

[0009] The conductor material of the aluminum alloy core fireproof cable is aluminum alloy, which has good heat conduction performance. When the cable encounters a fire, it can quickly disperse and transfer heat, avoiding excessive local temperature to accelerate the burning and decomposition of the insulation layer and the sheath layer, which helps to delay the destruction of the cable core structure by the fire. At the same time, aluminum alloy has high mechanical strength and excellent corrosion resistance. Its structural stability is better than that of traditional pure aluminum conductor in high-temperature fire environment, and it is not easy to break or deform due to heat, which can maintain the conductor's conductive path for a certain period of time, providing protection for emergency power supply or signal transmission in a fire. Combined with the excellent flame retardant performance of the sheath layer, the reliability and safety of the entire fireproof cable in a fire scene are further improved.

[0010] As a further technical solution, the material of the insulation layer is mica tape and silica gel tape.

[0011] As a further technical solution, the wrapping sequence of the insulation layer is to wrap 2-3 layers of mica tape first, and then wrap 2-3 layers of silica gel tape.

[0012] As a further technical solution, the material of the filling layer is rock wool rope.

[0013] As a further technical solution, the material of the heat insulation layer is fiberglass tape.

[0014] As a further technical solution, the material of the isolation layer is corrugated aluminum.

[0015] As a further technical solution, the fireproof layer is a mineral fireproof layer, and the material of the mineral fireproof layer is fireproof mud, which includes magnesium hydroxide and sodium silicate.

[0016] As a further technical solution, the metal acetylacetone complex includes one or both of copper acetylacetate and nickel acetylacetate.

[0017] In the sheath layer of the aluminum alloy core fireproof cable, the metal acetylacetone complex has excellent catalytic activity, which can efficiently promote the cross-linking and carbonization reaction of the polyvinyl chloride base material at high temperatures, promote the formation of a more dense and stable carbon layer, effectively block heat transfer and oxygen contact, reduce the release of flammable gas, and enhance the flame retardant performance of the sheath layer.

[0018] As a further technical solution, the mass ratio of the calcium oxide, the magnesium oxide and the zinc oxide is 1-2:1:1, and the mass ratio of the solid solution, the aluminum hydroxide, the ammonium polyphosphate and the metal acetylacetone complex is 2:5:4:0.5-1.

[0019] The mass ratio of the solid solution, the aluminum hydroxide, the ammonium polyphosphate and the metal acetylacetone complex in the sheath layer of the aluminum alloy core fireproof cable is 2:5:4:0.5-1, the proportion of the four is moderate, the functional conflict or efficiency loss caused by excessive single component is avoided, and the flame retardant performance of the sheath layer of the aluminum alloy core fireproof cable is finally significantly improved.

[0020] As a further technical solution, the ammonium polyphosphate is a composite ammonium polyphosphate, and a preparation method of the composite ammonium polyphosphate comprises the following steps: dispersing hydroxydichlorodiphenyl ether in a solvent, adding ammonium polyphosphate, and drying after mixing to obtain the composite ammonium polyphosphate.

[0021] In the sheath layer of the aluminum alloy core fireproof cable, the ammonium polyphosphate is a composite ammonium polyphosphate, and after the ammonium polyphosphate is compounded with hydroxydichlorodiphenyl ether, the benzene ring structure which is resistant to temperature and hydrophobic can be introduced on the surface of the ammonium polyphosphate, the decomposition rate of the ammonium polyphosphate at high temperature is delayed, the ammonium polyphosphate can play a more persistent role of expanding into carbon in a fire, and the dispersion and compatibility of the ammonium polyphosphate in a polyvinyl chloride matrix are enhanced by introducing the chlorine atom which has high polarity, the problem of uneven flame retardant effect caused by agglomeration of the ammonium polyphosphate is avoided, and the flame retardant performance of the fireproof cable is further improved.

[0022] As a further technical solution, in the composite ammonium polyphosphate, the mass ratio of the ammonium polyphosphate to the hydroxydichlorodiphenyl ether is 20:2-2.5.

[0023] As a further technical solution, the solvent is dichloromethane, and the mass ratio of the solvent to the ammonium polyphosphate is 3-5:1, for example, can be 3:1, 3.2:1, 3.5:1, 3.8:1, 4:1, 4.2:1, 4.5:1, 5:1, and preferably 4:1.

[0024] As a further technical solution, the mixing time is 3-4h, for example, can be 3.1h, 3.2h, 3.3h, 3.4h, 3.5h, 3.6h, 3.7h, 3.8h, 3.9h, 4h, and preferably 3.5h.

[0025] As a further technical solution, the plasticizer includes one or more of dioctyl phthalate, dibutyl phthalate and diisooctyl phthalate, and preferably dioctyl phthalate.

[0026] In the sheath layer of the aluminum alloy core fireproof cable, the plasticizer is added, the plasticizer can be inserted between the polyvinyl chloride molecular chains, the intermolecular force is weakened, the melt viscosity is reduced, the sheath layer material is more easily flowed in the extrusion and molding process, the processing energy consumption is reduced, the continuous and stable production of the cable sheath is ensured, and the molding defects caused by the material being too hard are avoided.

[0027] As a further technical solution, the antioxidant comprises one or more of antioxidant 1010, antioxidant 168, antioxidant 264, and preferably antioxidant 1010.

[0028] The antioxidant is added to the sheath layer of the aluminum alloy core fireproof cable, and the polyvinyl chloride is prone to oxidation reaction during high-temperature processing or long-term use, which leads to molecular chain rupture and mechanical property reduction.

[0029] As a further technical solution, the filler comprises one or both of calcium carbonate and talcum powder, and preferably talcum powder.

[0030] The filler is added to the sheath layer of the aluminum alloy core fireproof cable, and the filler can improve the rigidity of the material through particle reinforcement, adjust the melt flowability of the material, and reduce melt rupture, mold sticking and other problems during processing.

[0031] As a further technical solution, the lubricant comprises one or both of calcium stearate and zinc stearate, and preferably zinc stearate.

[0032] The lubricant is added to the sheath layer of the aluminum alloy core fireproof cable, and during material melting and processing, the lubricant can reduce the internal friction between resin molecules and the external friction between the melt and the surface of the processing equipment, reduce the melt viscosity, make the material flow and fill the mold more easily, avoid increased processing energy consumption or equipment wear caused by excessive friction, and reduce surface defects during material forming, making the product surface smoother and more uniform, improving the surface finish and consistency, and reducing the risk of stress concentration during later use.

[0033] The present application also provides a preparation method of an aluminum alloy core fireproof cable.

[0034] S1, the insulating layer material is wrapped around the conductor to form an insulating layer, and a filler layer, a bundled thermal insulation layer, an isolation layer and a fireproof layer are sequentially arranged outside the insulating layer to obtain a semi-finished product;

[0035] S2, the sheath layer raw material is mixed uniformly and extruded on the semi-finished product to obtain an aluminum alloy core fireproof cable.

[0036] The working principle and beneficial effects of the present application are as follows:

[0037] The sheath layer of the aluminum alloy core fireproof cable is prepared by mixing a solid solution of calcium oxide, magnesium oxide and zinc oxide and aluminum hydroxide, ammonium polyphosphate and metal acetylacetone complex. The smoke released by the combustion of polyvinyl chloride is effectively inhibited, and the fire resistance of the fireproof cable is improved. In the prior art, when polyvinyl chloride is used as the main raw material of the cable sheath layer, a large amount of smoke and flammable substances will be released during the combustion of polyvinyl chloride, which seriously affects the fire resistance of the fireproof cable. In the sheath layer of the aluminum alloy core fireproof cable, a solid solution is first prepared from calcium oxide, magnesium oxide and zinc oxide. The solid solution can reduce the amount of organic smoke generated by the decomposition of polyvinyl chloride. Aluminum hydroxide can absorb heat and release water vapor at high temperature, thereby achieving cooling and oxygen dilution. Ammonium polyphosphate promotes the formation of an expanded carbon layer, thereby strengthening the barrier to heat and oxygen. Metal acetylacetone complex catalyzes and promotes carbonization, thereby improving the compactness of the carbon layer. The various fire-retardant substances cooperate with each other to comprehensively inhibit the combustion reaction, effectively inhibit the spread of flames, and improve the fire resistance of the fireproof cable. DETAILED DESCRIPTION

[0038] The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to 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 a person of ordinary skill in the art without creative labor are within the scope of protection of the present application.

[0039] In the following examples and comparative examples:

[0040] Polyvinyl chloride: SG-5 type;

[0041] Calcium oxide: average particle size 325 mesh;

[0042] Magnesium oxide: average particle size 1 μm;

[0043] Zinc oxide: average particle size 100 mesh;

[0044] Talc: average particle size 325 mesh;

[0045] Ammonium polyphosphate: average particle size 325 mesh;

[0046] Aluminum hydroxide: average particle size 8000 mesh.

[0047] Example 1

[0048] A preparation method of an aluminum alloy core fireproof cable, comprising the following steps:

[0049] S1, first wrapping mica tape 2 layers outside the aluminum alloy conductor, then wrapping silicone tape 2 layers to form an insulation layer, and then sequentially arranging a rock wool rope filling layer, a glass fiber tape bundling heat insulation layer, a corrugated aluminum isolation layer and a fire clay fireproof layer outside the insulation layer to obtain a semi-finished product;

[0050] S2, uniformly mixing 100 parts of polyvinyl chloride, 10 parts of dioctyl phthalate, 10 parts of ethylene-vinyl acetate copolymer, 25 parts of flame retardant, 0.5 parts of antioxidant 1010, 10 parts of talc and 0.5 parts of zinc stearate, and extruding and packaging the mixture outside the semi-finished product to obtain the aluminum alloy core fireproof cable;

[0051] The preparation method of the flame retardant comprises the following steps: mixing calcium oxide, magnesium oxide and zinc oxide (mass ratio 1:1:1), annealing at 500 DEG C for 8h to obtain a solid solution, and mixing the solid solution with aluminum hydroxide, ammonium polyphosphate and copper acetylacetonate (mass ratio 2:5:4:0.5) to obtain the flame retardant.

[0052] Example 2

[0053] A preparation method of an aluminum alloy core fireproof cable comprises the following steps:

[0054] S1, first wrapping mica tape 2 layers outside the aluminum alloy conductor, then wrapping silicone tape 2 layers to form an insulation layer, and then sequentially arranging a rock wool rope filling layer, a glass fiber tape bundling heat insulation layer, a corrugated aluminum isolation layer and a fire clay fireproof layer outside the insulation layer to obtain a semi-finished product;

[0055] S2, uniformly mixing 100 parts of polyvinyl chloride, 10 parts of dioctyl phthalate, 10 parts of ethylene-vinyl acetate copolymer, 25 parts of flame retardant, 0.5 parts of antioxidant 1010, 10 parts of talc and 0.5 parts of zinc stearate, and extruding and packaging the mixture outside the semi-finished product to obtain the aluminum alloy core fireproof cable;

[0056] The preparation method of the flame retardant comprises the following steps: mixing calcium oxide, magnesium oxide and zinc oxide (mass ratio 1:1:1), annealing at 500 DEG C for 8h to obtain a solid solution, and mixing the solid solution with aluminum hydroxide, ammonium polyphosphate and copper acetylacetonate (mass ratio 2:5:4:0.5) to obtain the flame retardant.

[0057] Example 3

[0058] A preparation method of an aluminum alloy core fireproof cable comprises the following steps:

[0059] S1, first wrapping mica tape 2 layers outside the aluminum alloy conductor, then wrapping silicone tape 2 layers to form an insulation layer, and then sequentially arranging a rock wool rope filling layer, a glass fiber tape bundling heat insulation layer, a corrugated aluminum isolation layer and a fire clay fireproof layer outside the insulation layer to obtain a semi-finished product;

[0060] S2, polyvinyl chloride 100 parts, dioctyl phthalate 15 parts, ethylene-vinyl acetate copolymer 15 parts, flame retardant 30 parts, antioxidant 1010 1.5 parts, talc 20 parts, zinc stearate 1 part are mixed uniformly, and are extruded and wrapped on the semi-finished product to obtain an aluminum alloy core fireproof cable;

[0061] The preparation method of the flame retardant comprises the following steps: mixing calcium oxide, magnesium oxide and zinc oxide (mass ratio 1:1:1), annealing at 500 DEG C for 8h to obtain a solid solution, mixing the solid solution with aluminum hydroxide, ammonium polyphosphate and copper acetylacetonate (mass ratio 2:5:4:0.5) to obtain the flame retardant.

[0062] Example 4

[0063] Compared with example 2, the difference of example 4 is that the mass ratio of calcium oxide, magnesium oxide and zinc oxide is 2:1:1.

[0064] Example 5

[0065] Compared with example 4, the difference of example 5 is that the mass ratio of the solid solution, aluminum hydroxide, ammonium polyphosphate and copper acetylacetonate is 2:5:4:1.

[0066] Example 6

[0067] Compared with example 5, the difference of example 6 is that the copper acetylacetonate is replaced by an equal amount of nickel acetylacetonate.

[0068] Example 7

[0069] Compared with example 5, the difference of example 7 is that the ammonium polyphosphate is replaced by an equal amount of composite ammonium polyphosphate prepared by the following preparation method:

[0070] The preparation method of the composite ammonium polyphosphate comprises the following steps: dispersing hydroxydichlorodiphenyl ether in dichloromethane, adding ammonium polyphosphate, the mass ratio of hydroxydichlorodiphenyl ether and ammonium polyphosphate is 2:20, the mass ratio of dichloromethane and ammonium polyphosphate is 4:1, mixing for 3.5h and then drying to obtain the composite ammonium polyphosphate.

[0071] Example 8

[0072] Compared with example 7, the difference of example 8 is that the mass ratio of hydroxydichlorodiphenyl ether and ammonium polyphosphate is 2.5:20.

[0073] Comparative example 1

[0074] Compared with example 2, the difference of comparative example 1 is that the solid solution prepared by mixing calcium oxide, magnesium oxide and zinc oxide is not added, and the flame retardant is composed of aluminum hydroxide, ammonium polyphosphate and copper acetylacetonate with a mass ratio of 5:4:0.5.

[0075] Comparative Example 2

[0076] Comparative Example 2 is different from Example 2 in that no copper acetylacetonate is added, and the flame retardant is composed of solid solution, aluminum hydroxide and ammonium polyphosphate in a mass ratio of 2:5:4.

[0077] Comparative Example 3

[0078] Comparative Example 3 is different from Example 2 in that the solid solution is composed of calcium oxide and zinc oxide in a mass ratio of 1:1.

[0079] Comparative Example 4

[0080] Comparative Example 4 is different from Example 2 in that copper acetylacetonate is replaced by an equal amount of copper stearate.

[0081] Experimental Example 1

[0082] The sheath layer of the aluminum alloy core fire-resistant cable prepared in Examples 1-8 and Comparative Examples 1-4 is subjected to oxygen index test according to the test method specified in GB / T 2406.2-2009 “Determination of the flammability of plastics-Part 2: burning behaviour of small plies of materials-Method B”. The sample shape is type IV sample, the sample size is 100mm x 6mm x 3mm, and the ignition method is method A.

[0083] The test results are shown in Table 1.

[0084] Table 1: Performance test results of the aluminum alloy core fire-resistant cable prepared in Examples 1-8 and Comparative Examples 1-4

[0085]

[0086] As can be seen from Table 1, when the flame retardant is composed of solid solution, aluminum hydroxide, ammonium polyphosphate and metal acetylacetonate complex, and the solid solution is composed of calcium oxide, magnesium oxide and zinc oxide, the flame retardant performance of the aluminum alloy core fire-resistant cable can be improved.

[0087] When the composite ammonium polyphosphate prepared by compounding hydroxyl dichlorodiphenyl ether is added, the flame retardant performance of the aluminum alloy core fire-resistant cable can be further improved.

[0088] The above is only a preferred embodiment of the present application, and is not intended to limit the present application. Any modification, equivalent replacement, improvement, etc. made within the spirit and principles of the present application shall be included in the protection scope of the present application.

Claims

1. An aluminium alloy core fire resistant cable characterised in that, The cable comprises a conductor, an insulation layer, a filling layer, a bundling heat insulation layer, an isolation layer, a fireproof layer and a sheath layer arranged from inside to outside, the sheath layer comprises the following components by weight: 100 parts of polyvinyl chloride, 10-15 parts of plasticizer, 10-15 parts of ethylene-vinyl acetate copolymer, 25-30 parts of flame retardant, 0.5-1.5 parts of antioxidant, 10-20 parts of filler, and 0.5-1 part of lubricant, the preparation method of the flame retardant comprises the following steps: mixing calcium oxide, magnesium oxide and zinc oxide, and obtaining a solid solution after solid solution annealing, mixing the solid solution with aluminum hydroxide, ammonium polyphosphate and metal acetylacetone complex to obtain a flame retardant; The mass ratio of the calcium oxide, the magnesium oxide and the zinc oxide is 1-2:1:1, and the mass ratio of the solid solution, the aluminum hydroxide, the ammonium polyphosphate and the metal acetylacetone complex is 2:5:4:0.5-1; The ammonium polyphosphate is a composite ammonium polyphosphate, and the preparation method of the composite ammonium polyphosphate comprises the following steps: dispersing hydroxydichlorodiphenyl ether in a solvent, adding ammonium polyphosphate, and drying after mixing to obtain the composite ammonium polyphosphate.

2. An aluminium alloy core fire resistant cable as claimed in claim 1, wherein, The material of the conductor is aluminum alloy.

3. An aluminium alloy core fire resistant cable as claimed in claim 1, wherein, The material of the insulation layer is mica tape and silica gel tape.

4. An aluminum alloy core fire resistant cable according to claim 1, wherein, The metal acetylacetone complex comprises one or both of copper acetylacetone and nickel acetylacetone.

5. An aluminum alloy core fire resistant cable according to claim 1, wherein, In the composite ammonium polyphosphate, the mass ratio of the ammonium polyphosphate to the hydroxydichlorodiphenyl ether is 20:2-2.

5.

6. An aluminum alloy core fire resistant cable according to claim 1, wherein, The plasticizer comprises one or more of dioctyl phthalate, dibutyl phthalate and diisooctyl phthalate.

7. An aluminum alloy core fire resistant cable according to claim 1, wherein, The antioxidant comprises one or more of antioxidant 1010, antioxidant 168 and antioxidant 264. The filler comprises one or both of calcium carbonate and talcum powder. The lubricant comprises one or both of calcium stearate and zinc stearate.

8. A process for preparing an aluminum alloy core fire resistant cable, for preparing an aluminum alloy core fire resistant cable according to any one of claims 1 to 7, characterized in that, The method comprises the following steps: S1, wrapping the insulation layer material around the conductor to form an insulation layer, and obtaining a semi-finished product after sequentially arranging a filling layer, a bundling heat insulation layer, an isolation layer and a fireproof layer outside the insulation layer; S2, uniformly mixing the sheath layer raw material, and extruding the semi-finished product to obtain an aluminum alloy core fireproof cable.

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