A weather-resistant flexible fireproof cable and its preparation method

Abstract

The present invention discloses a weather-resistant flexible fireproof cable and a preparation method thereof, relating to the technical field of cables. First, titanium is plated on the surface of alumina fibers. Alumina fibers have excellent fireproof performance, while titanium easily forms titanium oxides at high temperatures. These oxides have good stability and fireproof performance, thereby further enhancing the fire resistance of the titanium-plated alumina fibers, preventing the alumina fibers from being eroded, and thus enhancing their weather resistance. Nickel silicate has a layered structure, and this layered structure can act as a protective barrier in flame retardant applications, thereby effectively delaying the thermal decomposition process of materials. Nickel, as a high-temperature resistant material, has the ability to catalyze carbon formation and has good fire resistance. Coating nickel silicate on the surface of the titanium-plated alumina fibers can further improve the fireproof performance of the titanium-plated alumina fibers.

Description

Technical Field

[0001] The present invention relates to the technical field of cables, and specifically to a weather-resistant flexible fireproof cable and a preparation method thereof. Background Art

[0002] With the increasing demand for infrastructure such as power and communication, the application of various cables is becoming increasingly widespread. However, during the use of cables, they are challenged by the external environment in multiple ways. Especially under harsh conditions such as high temperature and humidity, the performance and service life of cables are often severely affected. Traditional cables often have disadvantages such as poor fireproof ability and insufficient weather resistance when facing extreme weather or fires. In the case of high temperature or fire, the structure of ordinary cables is unstable, prone to combustion or melting, and power or communication signals cannot be effectively transmitted during crises such as fires. These problems not only affect the normal use of cables but may also lead to failures in the power system during emergencies such as fires, and even pose serious safety hazards.

[0003] To solve the above problems and improve the weather resistance and fireproof performance of cables, the present invention provides a weather-resistant flexible fireproof cable and a preparation method thereof. Summary of the Invention

[0004] The purpose of the present invention is to provide a weather-resistant flexible fireproof cable and a preparation method thereof to solve the problems raised in the prior art.

[0005] To achieve the above purpose, the present invention provides the following technical solutions:

[0006] A preparation method of a weather-resistant flexible fireproof cable, comprising the following steps:

[0007] Step 1: Take alumina fibers coated with nickel silicate, polypropylene grafted maleic anhydride, and polypropylene, stir evenly, melt and extrude, and injection mold to form a fireproof layer;

[0008] Step 2: Take alumina fibers coated with nickel silicate, weather-resistant polyurethane-modified acrylic emulsion, and a curing agent, stir evenly to obtain a protective coating;

[0009] Step 3: Coat the protective coating on the surface of the fireproof layer, irradiate with an ultraviolet lamp with a main wavelength of 365 nm, and cure to obtain a protective layer sleeve;

[0010] Step 4: Wrap an insulating layer, a metal layer, and an anti-puncture layer on the outer surface of the wire core in sequence, and then sleevethe protective layer sleeve to obtain a weather-resistant flexible fireproof cable;

[0011] The preparation method of the alumina fibers coated with nickel silicate is as follows:

[0012] Take titanium-plated alumina fibers and n-butyllithium, react at 85-90 °C for 4-5 h, cool to 25-30 °C, filter, wash, and dry to obtain compound A; take vinyltrimethoxysilane and ethanol, stir evenly to obtain a vinyltrimethoxysilane solution; take nickel chloride hexahydrate and ethanol, stir evenly to obtain a nickel chloride hexahydrate solution; take compound A and deionized water, ultrasonicate for 3-5 h, add the vinyltrimethoxysilane solution, stir for 4-5 h, add the nickel chloride hexahydrate solution, then dropwise add sodium hydroxide solution, stir for 30-40 min, stand for aging, centrifuge, dry, and grind to obtain alumina fibers coated with nickel silicate.

[0013] More preferably, the preparation method of the titanium-plated alumina fibers is as follows: It includes the following steps:

[0014] Step 1: Take alumina fibers, soak them in acetone for 50-70 min, take them out, wash, filter, oxidize them in an air atmosphere at 400 °C for 50-70 min, then react them in concentrated nitric acid for 1-2 h, take them out, wash, filter, and dry to obtain pretreated alumina fibers;

[0015] Step 2: Take acetone and hydrochloric acid, stir evenly to obtain a mixed solution; take alumina fibers and titanium powder, add ethanol, and wet grind to obtain mixture A; then add mixture A to the mixed solution, stir for 10-15 min, filter and dry to obtain mixture B, heat mixture B to 800-805 °C under argon protection, keep it warm for 30-40 min, then cool it to 25-30 °C, and sieve to obtain titanium-plated alumina fibers.

[0016] More preferably, the preparation method of the weather-resistant polyurethane-modified acrylic emulsion is as follows: Take hexamethylene diisocyanate, 2-hydroxyethyl methacrylate, polycarbonate polyol, and xylene, mix them evenly, and react at 80-85 °C for 4-5 h to obtain a polyurethane prepolymer; take methyl methacrylate, butyl acrylate, glycidyl methacrylate, styrene, isobornyl methacrylate, and dodecyl mercaptan, mix them evenly to obtain a mixed solution; add the mixed solution to xylene at 100 °C, add benzoyl peroxide, react for 5-6 h, add the polyurethane prepolymer and bis(2-ethylhexyl)tin mercaptoacetate, heat up to 100 °C and react for 1-2 h, add benzoyl peroxide, react for 1-2 h, and evacuate to obtain a weather-resistant polyurethane-modified acrylic emulsion.

[0017] More preferably, the fireproof layer is composed of the following substances: By mass, 8-10 parts of alumina fibers coated with nickel silicate, 1-3 parts of polypropylene grafted maleic anhydride, and 60-70 parts of polypropylene.

[0018] Preferably, the protective coating consists of the following substances: by mass, 2-3 parts of alumina fibers coated with nickel silicate, 20-25 parts of weather-resistant polyurethane-modified acrylic emulsion, and 2-4 parts of curing agent.

[0019] Preferably, the insulating layer is any one of polypropylene and polyethylene.

[0020] Preferably, the puncture-resistant layer is polyimide cloth.

[0021] Preferably, the particle size of the titanium-plated alumina fibers is 200-250 mesh.

[0022] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0023] 1. First, titanium is plated on the surface of alumina fibers in the present invention. Alumina fibers have excellent fireproof performance, and titanium easily forms titanium oxides at high temperatures. These oxides have good stability and fireproof performance, thus further enhancing the fire resistance of the titanium-plated alumina fibers, preventing the alumina fibers from being eroded, and enhancing their weather resistance.

[0024] 2. Nickel silicate has a layered structure, which can act as a protective barrier in flame retardant applications, thus effectively delaying the thermal decomposition process of materials. Nickel, as a high-temperature resistant material, has the ability to catalyze carbon formation and has good fire resistance. Coating nickel silicate on the surface of titanium-plated alumina fibers can further enhance the fireproof performance of the titanium-plated alumina fibers.

[0025] 3. The present invention also prepares a weather-resistant polyurethane-modified acrylic emulsion and uses it as a protective coating to improve the weather resistance of the cable. Vinyltrimethoxysilane is added during the preparation of the alumina fibers coated with nickel silicate in the present invention. Vinyltrimethoxysilane can react with the mercapto groups in the weather-resistant polyurethane-modified acrylic emulsion, thereby enhancing the crosslinking between the alumina fibers coated with nickel silicate and the weather-resistant polyurethane-modified acrylic emulsion, and enhancing the weather resistance and flame retardancy of the cable. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 It is a schematic structural diagram of a weather-resistant flexible fireproof cable of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0027] The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all of the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

[0028] There are no special restrictions on the sources and models of the substances involved in the present invention. Exemplarily, they include: polypropylene 5E89: Dongguan NabaiChuan Plastic Co., Ltd.; polyimide cloth (400 g / m2): Guangdong Jingao Special Rope & Belt Co., Ltd.; polypropylene grafted maleic anhydride: (grafting rate 1.2%) PO1015: ExxonMobil, USA; curing agent: amine curing agent P304226; polycarbonate polyol: model T5651, which can be purchased from Jining Fangyu Chemical Co., Ltd.; alumina fiber: 20 μm.

[0029] Example 1: A preparation method of a weather-resistant flexible fireproof cable, comprising the following steps:

[0030] Step 1: Preparation of titanium-plated alumina fiber:

[0031] Take alumina fiber, soak it in acetone for 60 min, take it out, wash, filter, oxidize it in an air atmosphere at 400 °C for 60 min, then react it in concentrated nitric acid with a concentration of 97 wt% at 80 °C for 1.5 h, take it out, wash, filter, and dry to obtain pretreated alumina fiber;

[0032] Take 400 mL of acetone and 60 mL of hydrochloric acid, stir evenly to obtain a mixed solution; take 10 g of alumina fiber and 55 g of 400-mesh titanium powder, add 300 mL of ethanol, and wet grind to obtain mixture A; then add mixture A to the mixed solution, stir for 12 min, filter and dry to obtain mixture B. Heat mixture B to 802 °C under argon protection, keep it warm for 35 min, then cool it to 28 °C, and pass it through a 200-mesh sieve to obtain titanium-plated alumina fiber;

[0033] Step 2: Preparation of alumina fiber coated with nickel silicate:

[0034] Take 2 g of titanium-plated alumina fiber and 70 mL of 0.5 M n-butyllithium, react at 88 °C for 4.5 h, cool to 28 °C, filter, wash, and dry to obtain compound A; take 0.55 g of vinyltrimethoxysilane and 150 mL of ethanol, stir evenly to obtain a vinyltrimethoxysilane solution; take 1.5 g of nickel chloride hexahydrate and 100 mL of ethanol, stir evenly to obtain a nickel chloride hexahydrate solution; take 0.3 g of compound A and 500 mL of deionized water, ultrasonicate for 4 h, add the vinyltrimethoxysilane solution, stir for 4.5 h, add the nickel chloride hexahydrate solution, then dropwise add 35 mL of 1 M sodium hydroxide solution, stir for 35 min, let it stand for aging, centrifuge, dry, and grind to obtain alumina fiber coated with nickel silicate;

[0035] Step 3: Preparation of weather-resistant polyurethane-modified acrylic emulsion:

[0036] Take 85 g of hexamethylene diisocyanate, 65 g of hydroxyethyl methacrylate, 50 g of polycarbonate polyol, and 300 mL of xylene, mix them evenly, and react at 82 °C for 4.5 h to obtain a polyurethane prepolymer;

[0037] Take 25 g of methyl methacrylate, 15 g of butyl acrylate, 23 g of glycidyl methacrylate, 10 g of styrene, 13 g of isobornyl methacrylate, and 2 g of dodecyl mercaptan, mix them evenly to obtain a mixed solution; add the mixed solution to 300 mL of xylene at 100 °C, add 7.2 g of benzoyl peroxide, react for 5.5 h, add 54 g of the polyurethane prepolymer and 5 g of bis(2-ethylhexyl)tin mercaptoacetate, raise the temperature to 100 °C and react for 1.5 h, add 0.7 g of benzoyl peroxide, react for 1.5 h, and evacuate to obtain a weather-resistant polyurethane-modified acrylic emulsion;

[0038] Step Four: Preparation of the weather-resistant flexible fireproof cable:

[0039] S1: Take alumina fiber coated with nickel silicate, polypropylene grafted maleic anhydride, and polypropylene, mix them evenly, melt and extrude, and injection mold to form a fireproof layer;

[0040] S2: Take alumina fiber coated with nickel silicate, weather-resistant polyurethane-modified acrylic emulsion, and a curing agent, mix them evenly to obtain a protective coating;

[0041] S3: Coat the protective coating on the surface of the fireproof layer, and irradiate it with an ultraviolet lamp with a main wavelength of 365 nm to cure and obtain a protective layer sleeve;

[0042] S4: Wrap an insulating layer, a metal layer, and a puncture-resistant layer on the outer surface of the wire core in sequence, and then sleeved with the protective layer sleeve to obtain a weather-resistant flexible fireproof cable;

[0043] The wire core is a copper core; the insulating layer is a polypropylene layer; the metal layer is woven from 0.1 mm galvanized copper wire; the puncture-resistant layer is a polyimide cloth; the thicknesses of the insulating layer, the metal layer, and the fireproof layer are 3 mm, and the thickness of the coating formed by the protective coating is 200 μm;

[0044] By mass, the fireproof layer is composed of the following substances: 9 parts of alumina fiber coated with nickel silicate, 2 parts of polypropylene grafted maleic anhydride, and 65 parts of polypropylene;

[0045] By mass, the protective coating is composed of the following substances: 2.5 parts of alumina fiber coated with nickel silicate, 22 parts of weather-resistant polyurethane-modified acrylic emulsion, and 3 parts of curing agent.

[0046] Example 2: A preparation method of a weather-resistant flexible fireproof cable, including the following steps:

[0047] Step One: Preparation of titanium-plated alumina fiber:

[0048] Take alumina fibers, soak them in acetone for 50 min, take them out, wash, filter, oxidize them in an air atmosphere at 400 °C for 50 min, then react them in concentrated nitric acid with a concentration of 97 wt% at 80 °C for 1 h, take them out, wash, filter, and dry to obtain pretreated alumina fibers;

[0049] Take 400 mL of acetone and 60 mL of hydrochloric acid, stir evenly to obtain a mixed solution; take 10 g of alumina fibers and 55 g of 400-mesh titanium metal powder, add 300 mL of ethanol, and wet grind to obtain mixture A; then add mixture A to the mixed solution, stir for 10 min, filter and dry to obtain mixture B, heat mixture B to 800 °C under argon protection, keep it warm for 30 min, then cool it to 25 °C, and pass it through a 200-mesh sieve to obtain titanium-plated alumina fibers;

[0050] Step 2: Preparation of nickel silicate-coated alumina fibers:

[0051] Take 2 g of titanium-plated alumina fibers and 70 mL of 0.5 M n-butyllithium, react at 85 °C for 4 h, cool to 25 °C, filter, wash, and dry to obtain compound A; take 0.55 g of vinyltrimethoxysilane and 150 mL of ethanol, stir evenly to obtain a vinyltrimethoxysilane solution; take 1.5 g of nickel chloride hexahydrate and 100 mL of ethanol, stir evenly to obtain a nickel chloride hexahydrate solution; take 0.3 g of compound A and 500 mL of deionized water, ultrasonicate for 3 h, add the vinyltrimethoxysilane solution, stir for 4 h, add the nickel chloride hexahydrate solution, then dropwise add 35 mL of 1 M sodium hydroxide solution, stir for 30 min, let it stand and age, centrifuge, dry, and grind to obtain nickel silicate-coated alumina fibers;

[0052] Step 3: Preparation of weather-resistant polyurethane-modified acrylic emulsion:

[0053] Take 85 g of hexamethylene diisocyanate, 65 g of 2-hydroxyethyl methacrylate, 50 g of polycarbonate polyol, and 300 mL of xylene, mix evenly, and react at 80 °C for 4 h to obtain a polyurethane prepolymer;

[0054] Take 25 g of methyl methacrylate, 15 g of butyl acrylate, 23 g of glycidyl methacrylate, 10 g of styrene, 13 g of isobornyl methacrylate, and 2 g of dodecyl mercaptan, mix evenly to obtain a mixed solution; add the mixed solution to 300 mL of xylene at 100 °C, add 7.2 g of benzoyl peroxide, react for 5 h, add 54 g of the polyurethane prepolymer and 5 g of bis(2-ethylhexyl)tin mercaptoacetate, heat to 100 °C and react for 1 h, add 0.7 g of benzoyl peroxide, react for 1 h, and evacuate to obtain a weather-resistant polyurethane-modified acrylic emulsion;

[0055] Step 4: Preparation of weather-resistant flexible fireproof cable:

[0056] S1: Take alumina fiber coated with nickel silicate, polypropylene grafted maleic anhydride, and polypropylene, stir evenly, melt and extrude, and injection mold to form a fireproof layer;

[0057] S2: Take alumina fiber coated with nickel silicate, weather-resistant polyurethane modified acrylic emulsion, and curing agent, stir evenly to obtain a protective coating;

[0058] S3: Coat the protective coating on the surface of the fireproof layer, irradiate with an ultraviolet lamp with a main wavelength of 365 nm, and cure to obtain a protective layer sleeve;

[0059] S4: Wrap an insulating layer, a metal layer, and a puncture-resistant layer on the outer surface of the wire core in sequence, and then set the protective layer sleeve to obtain a weather-resistant flexible fireproof cable;

[0060] The wire core is a copper core; the insulating layer is a polypropylene layer; the metal layer is woven from 0.1 mm galvanized copper wire; the puncture-resistant layer is a polyimide cloth; the thicknesses of the insulating layer, the metal layer, and the fireproof layer are 3 mm, and the thickness of the coating formed by the protective coating is 200 μm;

[0061] By mass, the fireproof layer is composed of the following substances: 8 parts of alumina fiber coated with nickel silicate, 1 part of polypropylene grafted maleic anhydride, and 60 parts of polypropylene;

[0062] By mass, the protective coating is composed of the following substances: 2 parts of alumina fiber coated with nickel silicate, 20 parts of weather-resistant polyurethane modified acrylic emulsion, and 2 parts of curing agent.

[0063] Example 3: A preparation method of a weather-resistant flexible fireproof cable, comprising the following steps:

[0064] Step 1: Preparation of titanium-plated alumina fiber:

[0065] Take alumina fiber, soak it in acetone for 70 min, take it out, wash, filter, oxidize it in an air atmosphere at 400 °C for 70 min, then react it in concentrated nitric acid with a concentration of 97 wt% at 80 °C for 2 h, take it out, wash, filter, and dry to obtain pretreated alumina fiber;

[0066] Take 400 mL of acetone and 60 mL of hydrochloric acid, stir evenly to obtain a mixed solution; take 10 g of alumina fiber and 55 g of 400-mesh titanium metal powder, add 300 mL of ethanol, and wet grind to obtain mixture A; then add mixture A to the mixed solution, stir for 15 min, filter and dry to obtain mixture B. Heat mixture B to 805 °C under argon protection, keep it warm for 40 min, then cool it to 30 °C, and pass it through a 200-mesh sieve to obtain titanium-plated alumina fiber;

[0067] Step 2: Preparation of alumina fiber coated with nickel silicate:

[0068] Take 2 g of titanium-plated alumina fiber and 70 mL of 0.5 M n-butyllithium, react at 90 °C for 5 h, cool to 30 °C, filter, wash and dry to obtain compound A; take 0.55 g of vinyltrimethoxysilane and 150 mL of ethanol, stir evenly to obtain a vinyltrimethoxysilane solution; take 1.5 g of nickel chloride hexahydrate and 100 mL of ethanol, stir evenly to obtain a nickel chloride hexahydrate solution; take 0.3 g of compound A and 500 mL of deionized water, ultrasonicate for 5 h, add the vinyltrimethoxysilane solution, stir for 5 h, add the nickel chloride hexahydrate solution, then dropwise add 35 mL of 1 M sodium hydroxide solution, stir for 40 min, stand for aging, centrifuge, dry and grind to obtain alumina fiber coated with nickel silicate;

[0069] Step 3: Preparation of weather-resistant polyurethane-modified acrylic emulsion:

[0070] Take 85 g of hexamethylene diisocyanate, 65 g of 2-hydroxyethyl methacrylate, 50 g of polycarbonate polyol, and 300 mL of xylene, mix evenly, and react at 85 °C for 5 h to obtain a polyurethane prepolymer;

[0071] Take 25 g of methyl methacrylate, 15 g of butyl acrylate, 23 g of glycidyl methacrylate, 10 g of styrene, 13 g of isobornyl methacrylate, and 2 g of dodecyl mercaptan, mix evenly to obtain a mixed solution; add the mixed solution to 300 mL of xylene at 100 °C, add 7.2 g of benzoyl peroxide, react for 6 h, add 54 g of the polyurethane prepolymer and 5 g of bis(2-ethylhexyl)tin mercaptoacetate, heat to 100 °C and react for 2 h, add 0.7 g of benzoyl peroxide, react for 2 h, and evacuate to obtain a weather-resistant polyurethane-modified acrylic emulsion;

[0072] Step 4: Preparation of weather-resistant flexible fireproof cable:

[0073] S1: Take alumina fiber coated with nickel silicate, polypropylene grafted maleic anhydride, and polypropylene, stir evenly, melt extrude and injection mold to form a fireproof layer;

[0074] S2: Take the alumina fiber coated with nickel silicate, weather-resistant polyurethane-modified acrylic emulsion, and curing agent, stir evenly to obtain a protective coating;

[0075] S3: Coat the protective coating on the surface of the fireproof layer, irradiate with an ultraviolet lamp with a main wavelength of 365 nm, and cure to obtain a protective layer sleeve;

[0076] S4: Wrap an insulating layer, a metal layer, and a puncture-resistant layer on the outer surface of the wire core in sequence, and then sleeved with the protective layer sleeve to obtain a weather-resistant flexible fireproof cable;

[0077] The wire core is a copper core; the insulating layer is a polypropylene layer; the metal layer is woven from 0.1 mm galvanized copper wire; the puncture-resistant layer is a polyimide cloth; the thicknesses of the insulating layer, the metal layer, and the fireproof layer are 3 mm, and the thickness of the coating formed by the protective coating is 200 μm.

[0078] By mass, the fireproof layer is composed of the following substances: 10 parts of alumina fiber coated with nickel silicate, 3 parts of polypropylene grafted maleic anhydride, and 70 parts of polypropylene.

[0079] By mass, the protective coating is composed of the following substances: 3 parts of alumina fiber coated with nickel silicate, 25 parts of weather-resistant polyurethane-modified acrylic emulsion, and 4 parts of curing agent.

[0080] Comparative Example 1: Do not coat titanium on the surface of the alumina fiber, and the rest is the same as in Example 1:

[0081] Step 1: Preparation of alumina fiber coated with nickel silicate:

[0082] Take 2 g of alumina fiber and 70 mL of 0.5 M n-butyllithium, react at 88 °C for 4.5 h, cool to 28 °C, filter, wash, and dry to obtain Compound A; take 0.55 g of vinyltrimethoxysilane and 150 mL of ethanol, stir evenly to obtain a vinyltrimethoxysilane solution; take 1.5 g of nickel chloride hexahydrate and 100 mL of ethanol, stir evenly to obtain a nickel chloride hexahydrate solution; take 0.3 g of Compound A, 500 mL of deionized water, sonicate for 4 h, add the vinyltrimethoxysilane solution, stir for 4.5 h, add the nickel chloride hexahydrate solution, then dropwise add 35 mL of 1 M sodium hydroxide solution, stir for 35 min, stand for aging, centrifuge, dry, and grind to obtain alumina fiber coated with nickel silicate;

[0083] Step 2: Preparation of weather-resistant polyurethane-modified acrylic emulsion:

[0084] Take 85 g of hexamethylene diisocyanate, 65 g of 2-hydroxyethyl methacrylate, 50 g of polycarbonate polyol, and 300 mL of xylene, mix evenly, and react at 82 °C for 4.5 h to obtain a polyurethane prepolymer;

[0085] Take 25 g of methyl methacrylate, 15 g of butyl acrylate, 23 g of glycidyl methacrylate, 10 g of styrene, 13 g of isobornyl methacrylate, and 2 g of dodecyl mercaptan, mix them evenly to obtain a mixed solution; add the mixed solution to 300 mL of xylene at 100 °C, add 7.2 g of benzoyl peroxide, react for 5.5 h, add 54 g of polyurethane prepolymer and 5 g of di-n-octyltin bis(mercaptoacetate), heat up to 100 °C and react for 1.5 h, add 0.7 g of benzoyl peroxide, react for 1.5 h, and evacuate to obtain a weather-resistant polyurethane-modified acrylic emulsion;

[0086] Step 3: Preparation of the weather-resistant flexible fireproof cable:

[0087] S1: Take alumina fibers coated with nickel silicate, polypropylene grafted maleic anhydride, and polypropylene, stir them evenly, melt and extrude, and injection mold to form a fireproof layer;

[0088] S2: Take alumina fibers coated with nickel silicate, weather-resistant polyurethane-modified acrylic emulsion, and a curing agent, stir them evenly to obtain a protective coating;

[0089] S3: Coat the protective coating on the surface of the fireproof layer, and irradiate it with an ultraviolet lamp with a main wavelength of 365 nm to cure and obtain a protective layer sleeve;

[0090] S4: Wrap an insulating layer, a metal layer, and a puncture-resistant layer on the outer surface of the wire core in sequence, and then set the protective layer sleeve to obtain a weather-resistant flexible fireproof cable;

[0091] The wire core is a copper core; the insulating layer is a polypropylene layer; the metal layer is woven from 0.1 mm galvanized copper wire; the puncture-resistant layer is a polyimide cloth; the thicknesses of the insulating layer, the metal layer, and the fireproof layer are 3 mm, and the thickness of the coating formed by the protective coating is 200 μm;

[0092] By mass, the fireproof layer is composed of the following substances: 9 parts of alumina fibers coated with nickel silicate, 2 parts of polypropylene grafted maleic anhydride, and 65 parts of polypropylene;

[0093] By mass, the protective coating is composed of the following substances: 2.5 parts of alumina fibers coated with nickel silicate, 22 parts of weather-resistant polyurethane-modified acrylic emulsion, and 3 parts of curing agent.

[0094] Comparative Example 2: Do not coat nickel silicate on the surface of the titanium-plated alumina fibers, and the rest is the same as in Example 1:

[0095] Step 1: Preparation of titanium-plated alumina fibers:

[0096] Take alumina fibers, soak them in acetone for 60 min, take them out, wash, filter, oxidize them in an air atmosphere at 400 °C for 60 min, then react them in concentrated nitric acid with a concentration of 97 wt% at 80 °C for 1.5 h, take them out, wash, filter, and dry to obtain pretreated alumina fibers;

[0097] Take 400 mL of acetone and 60 mL of hydrochloric acid, stir evenly to obtain a mixed solution; take 10 g of alumina fibers and 55 g of 400-mesh titanium metal powder, add 300 mL of ethanol, and wet grind to obtain mixture A; then add mixture A to the mixed solution, stir for 12 min, filter and dry to obtain mixture B, heat mixture B to 802 °C under argon protection, keep it warm for 35 min, then cool it to 28 °C, and screen it through a 200-mesh sieve to obtain titanium-plated alumina fibers;

[0098] Step 2: Preparation of weather-resistant polyurethane-modified acrylic emulsion:

[0099] Take 85 g of hexamethylene diisocyanate, 65 g of 2-hydroxyethyl methacrylate, 50 g of polycarbonate polyol, and 300 mL of xylene, mix evenly, and react at 82 °C for 4.5 h to obtain a polyurethane prepolymer;

[0100] Take 25 g of methyl methacrylate, 15 g of butyl acrylate, 23 g of glycidyl methacrylate, 10 g of styrene, 13 g of isobornyl methacrylate, and 2 g of dodecyl mercaptan, mix evenly to obtain a mixed solution; add the mixed solution to 300 mL of xylene at 100 °C, add 7.2 g of benzoyl peroxide, react for 5.5 h, add 54 g of polyurethane prepolymer and 5 g of bis(2-ethylhexyl)tin mercaptoacetate, heat to 100 °C and react for 1.5 h, add 0.7 g of benzoyl peroxide, react for 1.5 h, and evacuate to obtain a weather-resistant polyurethane-modified acrylic emulsion;

[0101] Step 4: Preparation of weather-resistant flexible fireproof cable:

[0102] S1: Take titanium-plated alumina fibers, polypropylene grafted maleic anhydride, and polypropylene, stir evenly, melt and extrude, and injection mold to form a fireproof layer;

[0103] S2: Take titanium-plated alumina fibers, weather-resistant polyurethane-modified acrylic emulsion, and curing agent, stir evenly to obtain a protective coating;

[0104] S3: Coat the protective coating on the surface of the fireproof layer, irradiate it with an ultraviolet lamp with a main wavelength of 365 nm, and cure to obtain a protective layer sleeve;

[0105] S4: Wrap an insulating layer, a metal layer, and an anti-puncture layer on the outer surface of the wire core in sequence, and then sleeved with the protective layer sleeve to obtain a weather-resistant flexible fireproof cable;

[0106] The wire core is a copper core; the insulating layer is a polypropylene layer; the metal layer is woven from 0.1 mm galvanized copper wire; the anti-puncture layer is a polyimide cloth; the thicknesses of the insulating layer, the metal layer, and the fireproof layer are 3 mm, and the thickness of the coating formed by the protective coating is 200 μm;

[0107] By mass fraction, the fireproof layer is composed of the following substances: 9 parts of titanium-plated alumina fiber, 2 parts of polypropylene grafted maleic anhydride, and 65 parts of polypropylene;

[0108] By mass fraction, the protective coating is composed of the following substances: 2.5 parts of titanium-plated alumina fiber, 22 parts of weather-resistant polyurethane-modified acrylic emulsion, and 3 parts of curing agent.

[0109] Comparative Example 3: Vinyltrimethoxysilane is not added, and the rest is the same as in Example 1:

[0110] Step 1: Preparation of titanium-plated alumina fiber:

[0111] Take alumina fiber, soak it in acetone for 60 min, take it out, wash it, filter it, oxidize it in an air atmosphere at 400 °C for 60 min, then react it in concentrated nitric acid with a concentration of 97 wt% at 80 °C for 1.5 h, take it out, wash it, filter it, and dry it to obtain pretreated alumina fiber;

[0112] Take 400 mL of acetone and 60 mL of hydrochloric acid, stir evenly to obtain a mixed solution; take 10 g of alumina fiber and 55 g of 400-mesh metal titanium powder, add 300 mL of ethanol, and wet grind to obtain mixture A; then add mixture A to the mixed solution, stir for 12 min, filter and dry to obtain mixture B, heat mixture B to 802 °C under argon protection, keep it warm for 35 min, then cool it to 28 °C, and pass it through a 200-mesh sieve to obtain titanium-plated alumina fiber;

[0113] Step 2: Preparation of alumina fiber coated with nickel silicate:

[0114] Take 2 g of titanium-plated alumina fiber and 70 mL of 0.5 M n-butyllithium, react at 88 °C for 4.5 h, cool to 28 °C, filter, wash, and dry to obtain compound A; take 1.5 g of nickel chloride hexahydrate and 100 mL of ethanol, stir evenly to obtain a nickel chloride hexahydrate solution; take 0.3 g of compound A and 500 mL of deionized water, sonicate for 4 h, add the nickel chloride hexahydrate solution, then dropwise add 35 mL of 1 M sodium hydroxide solution, stir for 35 min, stand for aging, centrifuge, dry, and grind to obtain alumina fiber coated with nickel silicate;

[0115] Step 3: Preparation of weather-resistant polyurethane-modified acrylic emulsion:

[0116] Take 85 g of hexamethylene diisocyanate, 65 g of hydroxyethyl methacrylate, 50 g of polycarbonate polyol, and 300 mL of xylene. Mix them evenly and react at 82 °C for 4.5 h to obtain a polyurethane prepolymer;

[0117] Take 25 g of methyl methacrylate, 15 g of butyl acrylate, 23 g of glycidyl methacrylate, 10 g of styrene, 13 g of isobornyl methacrylate, and 2 g of dodecyl mercaptan. Mix them evenly to obtain a mixed solution. Add the mixed solution to 300 mL of xylene at 100 °C, add 7.2 g of benzoyl peroxide, react for 5.5 h, add 54 g of the polyurethane prepolymer and 5 g of bis(2-ethylhexyl)tin mercaptoacetate, raise the temperature to 100 °C and react for 1.5 h, add 0.7 g of benzoyl peroxide, react for 1.5 h, and evacuate to obtain a weather-resistant polyurethane-modified acrylic emulsion;

[0118] Step 4: Preparation of the weather-resistant flexible fireproof cable:

[0119] S1: Take alumina fibers coated with nickel silicate, polypropylene grafted maleic anhydride, and polypropylene. Mix them evenly, melt and extrude, and injection mold to form a fireproof layer;

[0120] S2: Take alumina fibers coated with nickel silicate, the weather-resistant polyurethane-modified acrylic emulsion, and a curing agent. Mix them evenly to obtain a protective coating;

[0121] S3: Coat the protective coating on the surface of the fireproof layer and irradiate it with an ultraviolet lamp with a main wavelength of 365 nm for curing to obtain a protective layer sleeve;

[0122] S4: Wrap an insulating layer, a metal layer, and an anti-puncture layer on the outer surface of the wire core in sequence, and then sleevethe protective layer sleeve to obtain a weather-resistant flexible fireproof cable;

[0123] The wire core is a copper core; the insulating layer is a polypropylene layer; the metal layer is woven from 0.1 mm galvanized copper wire; the anti-puncture layer is a polyimide cloth; the thicknesses of the insulating layer, the metal layer, and the fireproof layer are 3 mm, and the thickness of the coating formed by the protective coating is 200 μm;

[0124] By mass, the fireproof layer is composed of the following substances: 9 parts of alumina fibers coated with nickel silicate, 2 parts of polypropylene grafted maleic anhydride, and 65 parts of polypropylene;

[0125] By mass, the protective coating is composed of the following substances: 2.5 parts of alumina fibers coated with nickel silicate, 22 parts of the weather-resistant polyurethane-modified acrylic emulsion, and 3 parts of the curing agent.

[0126] Experiment:

[0127] The protective layer sleeves prepared in Examples 1 to 3 and Comparative Examples 1 to 3 were cut into specimens of 5 cm × 1 cm × 0.5 cm, and then performance tests were carried out; the limiting oxygen index was used for the flame retardancy performance test; the tensile strength of the test samples was tested with reference to Part 11 of GB / T 2951.11-2008; the samples were placed in an oven at 100 °C for 7 days, and the tensile strength retention rate of each specimen after aging was calculated. The obtained data are shown in the following table:

[0128]

[0129] Conclusion: It can be seen from the comparison of the data in the table that in Comparative Example 1, titanium is not plated on the surface of alumina fibers, and the weather resistance and flame retardancy of the cable decrease. In Comparative Example 2, nickel silicate is not coated on the surface of the titanium-plated alumina fibers, and the flame retardancy of the cable decreases. In Comparative Example 3, vinyltrimethoxysilane is not added, and the weather resistance and flame retardancy of the cable decrease. In Examples 1 to 3, titanium is plated on the surface of alumina fibers. Alumina fibers have excellent fireproof performance, while titanium easily forms titanium oxides at high temperatures. These oxides have good stability and fire resistance, thus further improving the fire resistance of the titanium-plated alumina fibers, preventing the alumina fibers from being eroded, and thus enhancing their weather resistance. Coating nickel silicate on the surface of the titanium-plated alumina fibers can further improve the fireproof performance of the titanium-plated alumina fibers. Vinyltrimethoxysilane can react with the mercapto groups in the weather-resistant polyurethane-modified acrylic emulsion, thereby enhancing the crosslinking between the nickel silicate-coated alumina fibers and the weather-resistant polyurethane-modified acrylic emulsion, and thus enhancing the weather resistance and flame retardancy of the cable.

[0130] For those skilled in the art, it is obvious that the present invention is not limited to the details of the above exemplary embodiments, and can be implemented in other specific forms without departing from the spirit or basic characteristics of the present invention. Therefore, from any point of view, the embodiments should be regarded as exemplary and non-limiting. The scope of the present invention is defined by the appended claims rather than the above description. Therefore, all changes falling within the meaning and scope of the equivalent elements of the claims are intended to be included in the present invention. Any reference signs in the claims should not be regarded as limiting the claimed rights.

Claims

1. A method for preparing a weather-resistant flexible fire-resistant cable, characterized in that: The following steps are involved: Step 1: Take the alumina fiber coated with nickel silicate, polypropylene grafted with maleic anhydride, and polypropylene, mix them evenly, melt extrude them, and injection mold them to form a fireproof layer; Step 2: Take the alumina fiber coated with nickel silicate, the weather-resistant polyurethane modified acrylic emulsion, and the curing agent, stir them evenly to obtain a protective coating; Step 3: Apply the protective coating on the surface of the fireproof layer, irradiate with an ultraviolet lamp with a main wavelength of 365nm, and solidify to obtain a protective layer cover; Step 4: Wrap the outer surface of the wire core with an insulating layer, a metal layer, and an anti-puncture layer in sequence, and then cover it with a protective layer to obtain a weather-resistant flexible fire-proof cable; The preparation method of the alumina fiber coated with nickel silicate is: Take titanium-coated alumina fiber and n-butyl lithium, react at 85-90°C for 4-5h, cool to 25-30°C, filter, wash and dry to obtain compound A; take vinyltrimethoxysilane and ethanol, stir evenly to obtain vinyltrimethoxysilane solution; take nickel chloride hexahydrate and ethanol, stir evenly to obtain nickel chloride hexahydrate solution; take compound A and deionized water, ultrasonicate for 3-5h, add vinyltrimethoxysilane solution, stir for 4-5h, add nickel chloride hexahydrate solution, then add sodium hydroxide solution dropwise, stir for 30-40min, stand for aging, centrifuge, dry and grind to obtain alumina fiber coated with nickel silicate.

2. The method for preparing a weather-resistant flexible fire-resistant cable according to claim 1, characterized in that: The preparation method of the titanium-coated alumina fiber comprises the following steps: Step 1: Take alumina fiber, soak it in acetone for 50-70 minutes, take it out, wash it, filter it, oxidize it in an air atmosphere at 400°C for 50-70 minutes, then react it in concentrated nitric acid for 1-2 hours, take it out, wash it, filter it, and dry it to obtain pretreated alumina fiber; Step 2: Take acetone and hydrochloric acid, stir evenly to obtain a mixed solution; take alumina fiber and titanium powder, add ethanol, and wet grind to obtain mixture A; then add mixture A to the mixed solution, stir for 10-15 minutes, filter and dry to obtain mixture B, heat mixture B to 800-805°C under argon protection, keep warm for 30-40 minutes, then cool to 25-30°C, sieve to obtain titanium-coated alumina fiber.

3. The method for preparing a weather-resistant flexible fire-resistant cable according to claim 1, characterized in that: The preparation method of the weather-resistant polyurethane modified acrylic emulsion comprises the following steps: taking hexamethylene diisocyanate, hydroxyethyl methacrylate, polycarbonate polyol and xylene, mixing them evenly, and reacting them at 80-85°C for 4-5h to obtain a polyurethane prepolymer; taking methyl methacrylate, butyl acrylate, glycidyl methacrylate, styrene, isobornyl methacrylate and dodecyl mercaptan, mixing them evenly to obtain a mixed solution; adding the mixed solution to xylene at 100°C, adding dibenzoyl peroxide, reacting for 5-6h, adding the polyurethane prepolymer and di-n-octyltin bis(thioglycolate), heating to 100°C for reaction for 1-2h, adding dibenzoyl peroxide, reacting for 1-2h, and evacuating to obtain the weather-resistant polyurethane modified acrylic emulsion.

4. The method for preparing a weather-resistant flexible fire-resistant cable according to claim 1, characterized in that: The fireproof layer is composed of the following substances: 8-10 parts of alumina fibers coated with nickel silicate, 1-3 parts of polypropylene grafted with maleic anhydride, and 60-70 parts of polypropylene, calculated by weight.

5. The method for preparing a weather-resistant flexible fire-resistant cable according to claim 1, characterized in that: The protective coating is composed of the following substances: 2-3 parts of alumina fibers coated with nickel silicate, 20-25 parts of weather-resistant polyurethane modified acrylic emulsion, and 2-4 parts of curing agent, calculated by weight.

6. The method for preparing a weather-resistant flexible fire-resistant cable according to claim 1, characterized in that: The insulating layer is any one of polypropylene and polyethylene.

7. The method for preparing a weather-resistant flexible fire-resistant cable according to claim 1, characterized in that: The anti-puncture layer is polyimide cloth.

8. The method for preparing a weather-resistant flexible fire-resistant cable according to claim 2, characterized in that: The particle size of the titanium-coated alumina fiber is 200-250 meshes.

9. A weather-resistant flexible fire-resistant cable prepared according to the method for preparing a weather-resistant flexible fire-resistant cable according to any one of claims 1 to 8.

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