Fire-resistant flame-retardant coating, cable wrapping tape and preparation method of cable wrapping tape

Abstract

The invention discloses a fire-resistant flame-retardant coating, a cable wrapping tape and a preparation method thereof, and the preparation method comprises the following steps: carrying out oxygen plasma bombardment treatment on fire-resistant particles to obtain surface hydroxylated fire-resistant particles; dispersing the surface hydroxylated fire-resistant particles and carboxylated nanocellulose in a dispersion liquid according to a mass ratio of (5-15): 1 to obtain a cellulose-coated fire-resistant particle buffer solution; 26-38 parts of a buffer solution, 40-50 parts of water, 18-25 parts of ammonium polyphosphate, 12-18 parts of a charring agent, 5-8 parts of a nitrogen flame retardant, 18-25 parts of an AVE emulsion and 0.4-0.8 part of a defoaming agent are fully and uniformly mixed, and the water-soluble fireproof flame-retardant coating is obtained. A phosphorus-nitrogen flame retardant is compounded with a carbon forming agent to form a carbon shell after combustion, optimized and dispersed fire-resistant particles are uniformly inserted into the carbon shell by virtue of the expansion effect of the carbon forming agent to form fire-resistant particle aerogel, a cross-interpenetrating network structure of the fire-resistant particle aerogel and the carbon shell is formed, and a cross-interpenetrating flame-retardant layer which is flame-retardant, heat-insulating and fire-resistant is formed after a surface coating is combusted; and a stable environment is provided for normal operation of the cable.

Description

Technical Field

[0001] The invention relates to a fire-resistant flame-retardant material, and in particular to a fire-resistant flame-retardant coating, a cable tape and a preparation method thereof. Background Art

[0002] With the rapid development of my country's national economy, my country's power industry is also changing with each passing day, especially the output and quality of cables used for power transmission are also increasing exponentially. However, due to the imperfect structure of cables, many fires have been caused, which has also attracted widespread attention. The flame retardant and fire-resistant cables are being continuously improved and perfected.

[0003] The structural design of existing flame-retardant cables mostly improves the fire resistance of the cable by adding flame-retardant fillers in the sheath. As the amount of flame retardant fillers increases, while improving the fire resistance of the sheath, it will affect the uniformity of the sheath material, thereby affecting the mechanical stability of the sheath layer, causing the cable to crack during use due to the decrease in the mechanical properties of the sheath, affecting the stability of power transmission.

[0004] In addition, people have learned from the tragic lessons of electrical fire accidents that it is very important to maintain a stable operating state for a certain period of time in the event of a fire. In recent years, fire-resistant cables have received great attention, and more and more fire-resistant cable products have been introduced. In order to maintain long-term operation in emergency situations, materials with higher fire resistance points are currently used. Traditional fire-resistant technology usually reduces the flammability of materials by introducing fire-resistant additives into the material, through chemical reactions or physical effects. However, the addition of these agents will have an adverse effect on the mechanical properties and processing of the material, and will increase the cost of the material. Summary of the invention

[0005] In view of the problem that the above-mentioned flame retardant and fire-resistant materials will reduce the mechanical properties of cable tape, the present invention provides a fire-retardant flame retardant coating, cable tape and a preparation method thereof, which improves the fire resistance of the cable by improving the flame retardant and fire resistance of the cable tape material. This can reduce the amount of flame retardant added in the sheath, which can not only ensure the mechanical stability of the cable, but also ensure that the cable can still work stably for a period of time under instantaneous combustion conditions, thereby providing protection for actual production and life.

[0006] In order to achieve the above object, the present invention provides a method for preparing a fire-resistant flame-retardant coating, which comprises the following steps: S1, subjecting the refractory particles to oxygen plasma bombardment treatment to obtain surface hydroxylated refractory particles; S2, dispersing the surface hydroxylated refractory particles and carboxylated nanocellulose in a dispersion liquid at a mass ratio of (5-15):1 to obtain a cellulose-coated refractory particle buffer; S3. By mass, mix 26-38 parts of buffer solution, 40-50 parts of water, 18-25 parts of ammonium polyphosphate, 12-18 parts of carbonizing agent, 5-8 parts of nitrogen flame retardant, 18-25 parts of AVE emulsion and 0.4-0.8 parts of defoaming agent thoroughly to obtain a water-soluble fire-resistant flame-retardant coating.

[0007] In the above technical solution, the surface of nanocellulose itself has many hydroxyl groups and is hydrophilic. The carboxyl groups on the carboxylated nanocellulose and the hydroxyl groups on the surface of the hydroxylated refractory particles interact to form ester groups, and the cellulose will wrap the powder, and the hydrophilicity of the hydroxyl groups on the surface of the cellulose is used to improve the dispersibility of the refractory particles in the system.

[0008] The phosphorus-nitrogen flame retardant is compounded with a carbonizing agent to form a carbon shell after combustion. The optimized and dispersed refractory particles are evenly interspersed in the carbon shell with the help of the expansion effect of the carbonizing agent, forming a cross-interpenetrating network structure of refractory particle aerogel (cellulose is a long molecular chain, which plays a bonding role in the formation of aerogel) and the carbon shell. After the surface coating burns, a cross-interpenetrating flame retardant layer that is both flame retardant and heat insulating is formed, providing a stable environment for the normal operation of the cable.

[0009] As an environmentally friendly and easy-to-handle coating, water-based paint is more environmentally friendly than traditional organic coatings, with lower VOC emission levels. Secondly, the solvent is water, and a lower drying temperature can be used in the coating post-treatment process, which can further save energy. Finally, based on actual production, water-based paint is more friendly to construction workers, and no irritating and toxic gas volatilization causes harm to the human body. Therefore, the present invention uses water-based paint as the base material of the paint and selects different fillers to achieve flame retardant and fireproof effects through the synergistic effect between the fillers.

[0010] The highly flame-retardant fire-resistant flame-retardant coating prepared by the present invention has high flame retardancy, a vertical combustion grade of V-0, a fire resistance limit of more than 3 hours, and at the same time, the surface crust after combustion can meet the actual requirements of fire resistance and flame retardancy of flame-retardant cables.

[0011] Preferably, in step S1, the refractory particles are one or both of silicon dioxide and mica. The particle size of mica is 5-15 μm, and the particle size of silicon dioxide is 100-150 nm.

[0012] Among them, silica nanoparticles can be prepared by the following method: add ethyl orthosilicate, ammonia water and 75% alcohol in a three-necked flask at a mass ratio of 1:1:8, condense and reflux at 40°C and stir for 2 hours, then wash repeatedly with deionized water, and prepare silica nanoparticles after freeze-drying.

[0013] Preferably, in step S1, the oxygen plasma bombardment treatment is: power 400-600 W, 2-5 min.

[0014] The principle of oxygen plasma bombardment treatment is: plasma discharge generates high-energy electrons, which bombard gas molecules under the action of the electric field, freeing the outer surface electrons of the gas molecules from their binding and forming oxygen plasma. Oxygen plasma contains various types of particles, such as positive ions, negative ions, etc. When performing surface treatment on powders, the high-energy particles in the oxygen plasma bombard the surface of the powders, and while slightly etching the surface, a large number of free radicals and hydroxyl functional groups are introduced on the surface of the material.

[0015] Preferably, in step S2, the dispersing is: dispersing at 1800-2500 rpm for 2-3 h.

[0016] Specifically, in step S3, the carbon-forming agent is a triazine carbon-forming agent (CFA), and the nitrogen-based flame retardant is melamine cyanurate (MCA), melamine, or dicyandiamide.

[0017] Preferably, in step S3, the mixing is: dispersing at 1800-2500 rpm for 1-2 h.

[0018] The second aspect of the present invention provides a fire-resistant flame-retardant coating obtained by the above-mentioned preparation method.

[0019] The third aspect of the present invention provides a method for preparing a fire-resistant and flame-retardant cable tape, which comprises: soaking the glass fiber cloth or semi-glass fiber cloth in the above-mentioned fire-resistant and flame-retardant coating for 2 to 3 minutes, then taking it out, evenly scraping the paint liquid on both sides with a scraper, and finally heating it to form.

[0020] By preparing a water-based paint with flame retardant and fire resistant capabilities to impregnate the cable tape, the cable tape is given flame retardant and fire resistant properties. The flame retardant and fire resistant cable tape can ensure that the cable can be used for a certain period of time under fire conditions, thereby ensuring the stability of the power system.

[0021] The cable tape prepared by this method has flame retardancy and fire resistance. At the same time, the use of water-soluble resin as a coating provides strong support for energy conservation and environmental protection in a dual-carbon environment.

[0022] Preferably, the paint liquid has a thickness of 40-60 μm.

[0023] A third aspect of the present invention provides a fire-resistant and flame-retardant cable tape produced by the above-mentioned preparation method.

[0024] Through the above technical solution, the present invention achieves the following beneficial effects: In the present invention, the phosphorus-nitrogen flame retardant is compounded into a carbonizing agent to form a carbon shell after combustion, and the optimized and dispersed refractory particles are uniformly interspersed in the carbon shell by means of the expansion effect of the carbonizing agent, forming a cross-interpenetrating network structure of refractory particle aerogel and carbon shell, and after the surface coating is burned, a cross-interpenetrating flame retardant layer that is both flame retardant and heat-insulating and fire-resistant is formed, providing a stable environment for the normal operation of the cable. The cable wrapping tape made of the coating provides a guarantee for the flame retardant and fire-resistant ability of the cable while maintaining the stability of the internal structure of the cable. In this way, the function of the outer sheath can be restored, the addition of flame retardants in the sheath material can be reduced, the initial functionality of the material can be restored, and the functional loss of the outer sheath (cracking, insufficient toughness, etc.) can be prevented from causing damage to the cable. DETAILED DESCRIPTION

[0025] The specific embodiments of the present invention are described in detail below. It should be understood that the specific embodiments described herein are only used to illustrate and explain the present invention, and are not used to limit the present invention.

[0026] In the following examples, silica nanoparticles were prepared by the following method: 25 g of tetraethyl orthosilicate, 25 g of ammonia water and 200 g of 75% alcohol were added to a three-necked flask, condensed and refluxed at 40° C. with stirring for 2 h, then repeatedly washed with deionized water, and freeze-dried to prepare silica nanoparticles.

[0027] The model of oxygen plasma treatment equipment is Shanzhun Technology VP-TS7; Carboxylated nanocellulose was purchased from Guilin Qihong Technology, specification CNF-C; AVE emulsion was purchased from Dow, Brilliant RN-1000V; Ammonium polyphosphate was purchased from Guangzhou Yinyuan New Materials Co., Ltd., FR-AP1001; Carbon forming agent was purchased from Guangzhou Yinyuan New Materials Co., Ltd., FR-CFA; MCA was purchased from Guangzhou Yinyuan New Materials Co., Ltd., FR-MCA; Melamine was purchased from Suzhou Oumao Chemical Co., Ltd.; Dicyandiamide was purchased from Henan Xingding Chemical Products Co., Ltd.; Defoaming agent was purchased from Guangzhou Hongtai New Materials Co., Ltd.; Fiberglass cloth and semi-fiberglass cloth were purchased from Jiangsu Xinchenya New Materials Co., Ltd.

[0028] Embodiment 1: The preparation method of the flame retardant and fire resistant cable wrapping tape is as follows: (1) Placing silica nanoparticles into an oxygen plasma treatment apparatus and bombarding them at 500 W for 3 min to obtain surface hydroxylated silica nanoparticles; (2) 5 g of surface hydroxylated silica nanoparticles and 1 g of carboxylated nanocellulose were added to 20 g of water and stirred at 2000 rpm for 2 h to obtain a cellulose-coated silica nanoparticle buffer solution that can be evenly dispersed; (3) Add 40 g of water, 20 g of ammonium polyphosphate, 15 g of CFA carbon former, 5 g of nitrogen flame retardant MCA, 20 g of AVE emulsion, and 0.5 g of defoamer to the nanoparticle buffer, stir at 2000 rpm for 1 h, and mix thoroughly to obtain a water-soluble fire-resistant flame-retardant coating; (4) Soak the glass fiber cloth in the water-based fire-resistant coating for 2 minutes, then take it out and use a scraper to evenly apply 50 microns of paint liquid on both sides. Finally, heat the glass fiber cloth to form it to obtain a flame-retardant and fire-resistant composite cable tape.

[0029] Embodiment 2: (1) Place 1000-mesh mica powder into an oxygen plasma treatment apparatus and bombard it at 600W for 2 minutes to obtain surface hydroxylated mica particles; (2) adding 15 g of surface hydroxylated mica particles and 3 g of carboxylated nanocellulose to 20 g of water and stirring at 1800 rpm for 3 h to obtain a uniformly dispersed cellulose-coated mica particle buffer; (3) Add 50 g of water, 25 g of ammonium polyphosphate, 18 g of CFA carbon former, 8 g of nitrogen flame retardant melamine, 25 g of AVE emulsion, and 0.8 g of defoamer to the particle buffer, stir at 1800 rpm for 2 h, and mix thoroughly to obtain a water-soluble fire-resistant flame-retardant coating; (4) Soak the glass fiber cloth in the water-based fire-resistant coating for 2 minutes, then take it out and use a scraper to evenly apply 50 microns of paint liquid on both sides. Finally, heat the glass fiber cloth to form it to obtain a flame-retardant and fire-resistant composite cable tape.

[0030] Embodiment 3: (1) Placing silica nanoparticles into an oxygen plasma treatment apparatus and bombarding them at 400 W for 5 min to obtain surface hydroxylated silica nanoparticles; (2) Place 1000-mesh mica powder into an oxygen plasma treatment apparatus and bombard it at 400W for 5 minutes to obtain surface hydroxylated mica particles; (3) Add 5 g of surface hydroxylated mica particles and 1 g of carboxylated nanocellulose to 20 g of water and stir at 2500 rpm for 30 min. Add 10 g of surface hydroxylated silica nanoparticles and 0.4 g of defoamer and continue stirring at 2500 rpm for 30 min to obtain a composite uniform refractory particle buffer solution of silica-coated mica; (4) Add 40 g of water, 18 g of ammonium polyphosphate, 12 g of CFA carbon former, 5 g of nitrogen flame retardant dicyandiamide, and 18 g of AVE emulsion to the particle buffer, stir at 2500 rpm for 1 h, and mix thoroughly to obtain a water-soluble fire-resistant flame-retardant coating; (5) Soak the semi-glass fiber cloth in the water-based fire-resistant coating for 2 minutes, then take it out and use a scraper to evenly apply 50 microns of paint liquid on both sides. Finally, heat the glass fiber cloth to form it to obtain a flame-retardant and fire-resistant composite cable tape.

[0031] Comparative Example 1 Other conditions were the same as those in Example 1, except that the silicon dioxide nanoparticles were not subjected to hydroxylation treatment.

[0032] Comparative Example 2 Other conditions were the same as in Example 1, except that the silicon dioxide nanoparticles were not hydroxylated, and the carboxylated nanocellulose was replaced by ordinary nanocellulose.

[0033] Comparative Example 3 Other conditions were the same as in Example 1, except that the carboxylated nanocellulose was replaced by ordinary nanocellulose.

[0034] Comparative Example 4: Other conditions are the same as those in Example 2, except that the 1000-mesh mica powder in step (1) is replaced with 3000-mesh mica powder.

[0035] Comparative Example 5: The other conditions were the same as those in Example 3, except that step (3) was replaced by 10 g of surface hydroxylated silica particles, 1 g of carboxylated nanocellulose was added to 20 g of water, and stirred at 2000 rpm for 30 min. 5 g of surface hydroxylated mica particles and 0.4 g of defoamer were added, and stirring was continued at 2000 rpm for 30 min to obtain a refractory particle buffer.

[0036] Performance Testing The following performance tests were performed on the cable tapes prepared in Examples 1 to 3 and Comparative Examples 1 to 5: (1) Flame retardant performance test: Use UL-94 horizontal and vertical combustion test machine to test according to UL-94 test standard; (2) Tensile strength: tested using a universal tensile strength testing machine; (3) Fire resistance performance test: Fire resistance test is carried out according to GB / T 9978.1-2008 standard, the sample size is 500mm×500mm×3mm; (4) Limiting oxygen index test: The limiting oxygen index test is carried out according to GB / T 2406.2-2009 standard.

[0037] The test results are shown in Table 1.

[0038] Table 1 Performance test results

[0039] From the above results we can see that: (1) The flame retardant coating formula with a cross-interpenetrating network structure of the present invention has better fire resistance, flame retardant properties and mechanical properties, and its fire resistance time can exceed 3 hours. The fire resistance limit of the coating using carboxylated nanocellulose alone (Comparative Example 1), surface hydroxylated silica (Comparative Example 3), and both ordinary nanocellulose and silica (Comparative Example 2) cannot reach more than 3 hours. This is because the refractory particles cannot be evenly dispersed in the system, resulting in the inability to form a cross-interpenetrating network structure. (2) The mechanical properties and fire resistance of the coating prepared using 3000 mesh mica powder (Comparative Example 4) are poor. This is because the overly fine mica powder cannot be well dispersed in the system, thereby affecting the mechanical properties and fire resistance.

[0040] (3) The fire resistance of the coating prepared by using mica to wrap silica particles (Comparative Example 5) is poor. This is because during the combustion process, the mica prevents the carbon shell and the silica aerogel from forming a uniform interpenetrating network structure, which affects the fire resistance of the paint.

[0041] The preferred embodiments of the present invention are described in detail above. However, the present invention is not limited to the specific details in the above embodiments. Within the technical concept of the present invention, a variety of simple modifications can be made to the technical solution of the present invention, and these simple modifications all belong to the protection scope of the present invention.

[0042] It should also be noted that the various specific technical features described in the above specific embodiments can be combined in any suitable manner without contradiction. In order to avoid unnecessary repetition, the present invention will not further describe various possible combinations.

[0043] In addition, various embodiments of the present invention may be arbitrarily combined, and as long as they do not violate the concept of the present invention, they should also be regarded as the contents disclosed by the present invention.

Claims

1. A method for preparing a fire-resistant flame-retardant coating, characterized in that: The steps include: S1, subjecting the refractory particles to oxygen plasma bombardment treatment to obtain surface hydroxylated refractory particles; S2, dispersing the surface hydroxylated refractory particles and carboxylated nanocellulose in a dispersion liquid at a mass ratio of (5-15):1 to obtain a cellulose-coated refractory particle buffer; S3. By mass, mix 26-38 parts of buffer solution, 40-50 parts of water, 18-25 parts of ammonium polyphosphate, 12-18 parts of carbonizing agent, 5-8 parts of nitrogen flame retardant, 18-25 parts of AVE emulsion and 0.4-0.8 parts of defoaming agent thoroughly to obtain a water-soluble fire-resistant flame-retardant coating.

2. The preparation method according to claim 1, characterized in that: In step S1, the refractory particles are one or both of silica and mica.

3. The preparation method according to claim 1, characterized in that: In step S1, the oxygen plasma bombardment treatment is: power 400-600W, 2-5min.

4. The preparation method according to claim 1, characterized in that: In step S2, the dispersion is carried out at 1800-2500 rpm for 2-3 h.

5. The preparation method according to claim 1, characterized in that: In step S3, the carbon-forming agent is a triazine carbon-forming agent, and the nitrogen-based flame retardant is melamine cyanurate, melamine, or dicyandiamide.

6. The preparation method according to claim 1, characterized in that: In step S3, the mixing is: dispersing at 1800-2500 rpm for 1-2 h.

7. The fire-resistant flame-retardant coating prepared by the preparation method according to any one of claims 1 to 6.

8. A method for preparing a fire-resistant and flame-retardant cable tape, characterized in that: include: The glass fiber cloth or semi-glass fiber cloth is soaked in the fire-resistant flame-retardant coating of claim 7 for 2-3 minutes, then taken out, and the paint liquid is evenly scraped on both sides with a scraper, and finally heated to form.

9. The preparation method according to claim 8, characterized in that: The thickness of the paint liquid is 40-60 μm.

10. The fire-resistant and flame-retardant cable tape prepared by the preparation method according to claim 8 or 9.

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