Solvent-free dealcoholization type anti-pollution flashover coating containing hyperbranched cross-linking agent and preparation method thereof

Abstract

The invention discloses a solvent-free dealcoholization type anti-pollution flashover coating containing a hyperbranched cross-linking agent and a preparation method of the solvent-free dealcoholization type anti-pollution flashover coating, and belongs to the technical field of coatings. The solvent-free dealcoholization type anti-pollution flashover coating is prepared from the following components in parts by mass: 80 to 100 parts of alkoxy silicone oil, 40 to 75 parts of filler, 3 to 7 parts of hyperbranched cross-linking agent, 0.2 to 0.5 part of catalyst, 1 to 3 parts of curing accelerator, 0.5 to 3 parts of coupling agent and 60 to 100 parts of structure control agent, wherein the hyperbranched cross-linking agent is prepared from vinyl trimethoxy silane and trimethoxy hydrogen silane through a cross-linking reaction under the action of an oxidizing agent and a platinum catalyst. The self-made hyperbranched cross-linking agent is added into the solvent-free dealcoholization type anti-pollution flashover coating, so that the mechanical property of the coating can be effectively improved, and the coating has excellent electrical property, meets the requirements of spraying construction and meets the comprehensive performance requirements of the anti-pollution flashover coating.

Description

Technical Field

[0001] The invention relates to the field of coatings, and in particular to an anti-fouling flashover coating containing a hyperbranched crosslinking agent and a preparation method thereof. Background Art

[0002] Anti-pollution flashover coating is a deketoxime type anti-pollution flashover coating prepared based on the film-forming principle of deketoxime small molecules. The removed butanone oxime small molecules are reproductively toxic. Traditional anti-pollution flashover coatings use a large amount of organic solvents with a solid content of less than 50%. At present, volatile organic compounds (VOCs) are important raw materials for anti-pollution flashover coatings in the power industry. Room temperature curing anti-pollution flashover coatings are one of the most widely used power protection materials. The organic solvents used are mixtures of alkanes, halogenated hydrocarbons, olefins, aromatic hydrocarbons, etc., accounting for about 30%-70% of the total weight of the coating. They do not participate in the film formation of the coating and are completely volatilized into the atmosphere, causing a greater negative impact on the environment.

[0003] The existing solvent-free dealcoholization RTV can be cured into elastic silicone rubber at room temperature without heating, light or other special conditions, which is very convenient. In addition, the products on the market have maintained the main components of the original RTV coating and good adhesion, hydrophobicity and hydrophobic migration characteristics and weather resistance by adjusting the molecular structure and combination of polydimethylsiloxane; but they have some weaknesses such as slightly weaker mechanical properties or poor fluidity.

[0004] However, the solvent-free dealcoholized RTV currently on the market has certain defects, such as excessive viscosity, low mechanical properties, or short storage time. It cannot achieve both performance and does not meet the requirements of spraying operations. Summary of the invention

[0005] Purpose of the invention: The first purpose of the present invention is to provide a solvent-free dealcoholization anti-fouling flashover coating containing a hyperbranched cross-linking agent which has low viscosity and excellent mechanical and electrical properties. The second purpose of the present invention is to provide a method for preparing the above-mentioned solvent-free dealcoholization anti-fouling flashover coating containing a hyperbranched cross-linking agent.

[0006] Technical solution: The solvent-free dealcoholization anti-fouling flashover coating containing a hyperbranched crosslinker described in the present invention comprises the following components, measured by mass: 80-100 parts of alkoxy silicone oil, 40-75 parts of filler, 3-7 parts of hyperbranched crosslinker, 0.2-0.5 parts of catalyst, 1-3 parts of curing accelerator, 0.5-3 parts of coupling agent and 60-100 parts of structure control agent, wherein the hyperbranched crosslinker is prepared by crosslinking reaction of vinyltrimethoxysilane and trimethoxyhydrogensilane under the action of an oxidant and a platinum catalyst.

[0007] Preferably, the solvent-free dealcoholization anti-fouling flashover coating containing a hyperbranched crosslinker comprises the following components in parts by mass: 80-100 parts of alkoxy silicone oil, 55-65 parts of filler, 3-7 parts of hyperbranched crosslinker, 0.2-0.5 parts of catalyst, 2.5-3 parts of curing accelerator, 2.75-3 parts of coupling agent and 75-100 parts of structure control agent.

[0008] Furthermore, the volume ratio of the vinyltrimethoxysilane and trimethoxyhydrogensilane is 5-7:1-2, preferably 5:1, the oxidant is perbenzoic acid, and the platinum catalyst is platinum water; the amount of the oxidant accounts for 6-12% of the total volume of vinyltrimethoxysilane and trimethoxysilane, preferably 8.2-8.4%; further, the amount of the catalyst accounts for 0.5-1.5% of the total volume of vinyltrimethoxysilane and trimethoxysilane, preferably 1%.

[0009] Furthermore, the conditions of the cross-linking reaction are: stirring at 70-80°C for 5-6 hours, and then distilling at 100°C for 2-4 hours.

[0010] Furthermore, the alkoxy silicone oil is one or more of terminal hydrogen-containing polysiloxane, terminal methoxyvinyl polysiloxane, terminal methoxy fluorine-containing polysiloxane, and terminal methoxy polydimethylsiloxane, preferably terminal methoxyvinyl polysiloxane.

[0011] Furthermore, the filler is one or more of nano titanium dioxide, aluminum hydroxide, iron hydroxide, white carbon black, silicon carbide, aluminum oxide, aluminum nitride, plaster of Paris, boron nitride, silicon carbide, clay, silicon powder, asbestos wool or calcium carbonate, preferably a combination of white carbon black and aluminum hydroxide, with a mass ratio of 25-35:30.

[0012] Furthermore, the structure control agent is one or more of hydroxy silicone oil, diphenylsilanediol, hexamethyldisilazane, cyclic trisilazane, and vinyl silicone oil, preferably a combination of hexamethyldisilazane and vinyl silicone oil, with a mass ratio of 5-10:70-90; the curing accelerator is di-n-hexylamine, N-methylimidazole or dimethyl sulfoxide, preferably di-n-hexylamine.

[0013] Furthermore, the coupling agent is one or more of γ-aminopropyltriethoxysilane, γ-glycidyloxypropyltrimethoxysilane, γ-methacryloxypropyltrimethoxysilane, and N-(β-aminoethyl)-γ-aminopropyltrimethoxysilane, preferably a combination of γ-glycidyloxypropyltrimethoxysilane and γ-aminopropyltriethoxysilane, with a mass ratio of 1.5:1.25-1.5.

[0014] Furthermore, the catalyst is one or more of a platinum catalyst, a titanate, ethyl acetoacetate or tetramethylammonium hydroxide, preferably tetrabutyl titanate.

[0015] The preparation method of the above-mentioned solvent-free dealcoholization anti-fouling flashover coating containing a hyperbranched crosslinker comprises the following steps: adding filler to alkoxy silicone oil and stirring thoroughly, then adding a structure control agent to prevent structuring, continuing to add a coupling agent, a hyperbranched crosslinker, a curing accelerator, and a catalyst and stirring thoroughly, and finally filtering to obtain a solvent-free dealcoholization anti-fouling flashover coating containing a hyperbranched crosslinker.

[0016] Principle of the invention: Currently, most of the existing solvent-free dealcoholization coatings are high-viscosity fluids. In order to meet the requirements of solvent-free, low viscosity and high performance at the same time, the invention makes a self-made hyperbranched crosslinking agent with a multi-dimensional spatial network structure, which can effectively enhance the strength of the low-viscosity solvent-free dealcoholization coating after curing, and meet the fast and convenient process use on site and the performance requirements of power materials. The coating of the present invention uses alkoxy silicone oil as a matrix, adds catalysts, fillers, structure control agents, curing accelerators, coupling agents as auxiliary agents, and adds hyperbranched crosslinking agents to improve the degree of crosslinking, so that the mechanical properties are greatly improved, and a solvent-free dealcoholization anti-pollution flashover coating is prepared, so that the dealcoholization anti-pollution flashover coating can still meet the construction conditions required for use under solvent-free conditions, while maintaining good mechanical properties, and can meet other properties of the anti-pollution flashover coating. Compared with traditional deketoxime anti-pollution flashover coatings, it can reduce the volatilization of organic solvents and the generation of ketoxime small molecules with reproductive toxicity, and has important environmental protection significance. In addition, the present invention controls the mass ratio of fillers and hyperbranched crosslinking agents, and improves the mechanical properties of the coating through the synergistic effect of the two.

[0017] Hyperbranching is achieved by adjusting the hyperbranched topological structure and has abundant terminal functional groups, which are easy to modify. A moderate degree of branching and end group modification can impart a covalent / non-covalent crosslinking balance, thereby obtaining optimal tensile strength and toughness. The hyperbranched crosslinking agent in the present invention is a suitable hyperbranched synthetic product given for the current formula. The current mass ratio can achieve optimal mechanical properties and toughness with a relatively small amount, after matching the reinforcing filler, while having high fluidity.

[0018] Beneficial effects: Compared with the prior art, the present invention has the following significant advantages: (1) Compared with the existing solvent-free dealcoholization RTV, the coating of the present invention takes into account both mechanical properties and fluidity, and meets the requirements of high performance, fluidity, and solvent-free at the same time. No organic solvent is added during the preparation process, which can reduce pollution to the environment and reduce corrosion to metal and other substrates, which can meet the needs of environmental protection policies and practical application requirements; (2) The manufacturing cost is low and the construction is easy; (3) Experimental results show that the solvent-free environmentally friendly dealcoholization anti-pollution flashover coating containing a hyperbranched crosslinking agent of the present invention has high mechanical properties, which can reach more than 3MPa, and has more excellent electrical properties, with a dielectric strength of more than 18KV / mm. At the same time, it can meet the requirements of spraying construction and meet the comprehensive performance requirements of anti-pollution flashover coatings. DETAILED DESCRIPTION

[0019] The present invention is further described below in conjunction with specific embodiments.

[0020] Example 1: The composition and mass of the solvent-free dealcoholization anti-fouling flashover coating containing a hyperbranched crosslinking agent provided in this example are shown in Table 1.

[0021] Table 1 Component mass table of solvent-free dealcoholization anti-pollution flashover coating in Example 1

[0022]

[0023] Among them, the preparation method of the hyperbranched crosslinker is: add 50 ml of vinyl trimethoxysilane into a 250 ml three-necked flask, place it in an aqueous solution at 70°C, slowly drip 10 ml of trimethoxy hydrogen silane, then slowly drip 5 ml of perbenzoic acid and 0.6 ml of platinum water, stir for 5 hours, and then distill at 100°C for 2 hours to obtain a hyperbranched crosslinker.

[0024] The preparation method of the above-mentioned solvent-free dealcoholization anti-fouling flashover coating is as follows: filler is added to alkoxy silicone oil and stirred fully, then a structure control agent is added to prevent structuring, coupling agent, hyperbranched cross-linking agent, curing accelerator and catalyst are continuously added and stirred fully, and finally filtered to obtain a solvent-free dealcoholization anti-fouling flashover coating containing a hyperbranched cross-linking agent.

[0025] Example 2: The difference from Example 1 is that the mass fraction of the hyperbranched crosslinking agent is 4 parts.

[0026] Example 3: The difference from Example 1 is that the mass parts of the hyperbranched crosslinking agent are 4.5 parts, and the mass parts of the filler are 60 parts (30 parts of white carbon black and 30 parts of aluminum hydroxide).

[0027] Example 4: The difference from Example 1 is that the mass part of the hyperbranched crosslinking agent is 5 parts, and the mass part of the filler is 65 parts (35 parts of white carbon black, 30 parts of aluminum hydroxide).

[0028] Example 5: The difference from Example 1 is that the mass part of the hyperbranched crosslinking agent is 7 parts, and the mass part of the filler is 65 parts (35 parts of white carbon black, 30 parts of aluminum hydroxide).

[0029] Comparative Example 1: The difference from Example 1 is that the crosslinking agent is vinyltrimethoxysilane, and the mass fraction is the same as that of Example 1.

[0030] Comparative Example 2: The difference from Example 1 is that the mass fraction of the hyperbranched crosslinking agent is 10 parts.

[0031] Comparative Example 3: The difference from Example 1 is that the mass parts of the filler are 45 parts (15 parts of white carbon black, 30 parts of aluminum hydroxide).

[0032] The coatings prepared in Examples 1 to 5 and Comparative Examples 1 to 3 were subjected to performance tests, and the results are shown in Table 2 below.

[0033] Table 2 Experimental data table of Example 1-Example 5 and Comparative Example 1-Comparative Example 3

[0034]

[0035] It can be seen from Table 2 that compared with Examples 1 to 5, Comparative Example 1 uses a conventional cross-linking agent, whose Si-O-Si bond is relatively long and has a large bond angle, so it is not very stable and is easy to rotate, resulting in a small intermolecular force. The molecules often show a highly flexible state, and their mechanical properties are often weak, which cannot meet the requirements of power materials.

[0036] Between Examples 1 and 5, there is a certain amount of variation in the combination of the filler white carbon black used for reinforcement and the hyperbranched crosslinking agent for improving mechanical properties. When the filler is 55-65 parts, the white carbon black is 25-35 parts, and the hyperbranched crosslinking agent is 3-7 parts, the performance is relatively high. Among them, when the filler is 65 parts, the white carbon black is 35 parts, and the hyperbranched crosslinking agent is 5 parts, the comprehensive performance of the coating is optimal. In Comparative Examples 2 and 3, increasing the mass of the hyperbranched crosslinking agent or reducing the mass of the filler will lead to a significant decrease in the mechanical properties of the coating.

Claims

1. A solvent-free dealcoholization anti-fouling flashover coating containing a hyperbranched crosslinking agent, characterized in that: The invention comprises the following components by weight: 80-100 parts of alkoxy silicone oil, 40-75 parts of filler, 3-7 parts of hyperbranched crosslinking agent, 0.2-0.5 parts of catalyst, 1-3 parts of curing accelerator, 0.5-3 parts of coupling agent and 60-100 parts of structure control agent, wherein the hyperbranched crosslinking agent is prepared by crosslinking reaction of vinyltrimethoxysilane and trimethoxyhydrogensilane under the action of oxidant and platinum catalyst.

2. The solvent-free dealcoholization anti-fouling flashover coating according to claim 1, characterized in that: The volume ratio of the vinyltrimethoxysilane to trimethoxyhydrogensilane is 5-7:1-2.

3. The solvent-free dealcoholization anti-fouling flashover coating according to claim 1, characterized in that: The oxidizing agent is perbenzoic acid.

4. The solvent-free dealcoholization anti-fouling flashover coating according to claim 1, characterized in that: The platinum catalyst is platinum water.

5. The solvent-free dealcoholization anti-fouling flashover coating according to claim 1, characterized in that: The amount of the oxidant used accounts for 6-12% of the total volume of vinyltrimethoxysilane and trimethoxyhydrogensilane.

6. The solvent-free dealcoholization anti-fouling flashover coating according to claim 1, characterized in that: The amount of the catalyst used accounts for 0.5-1.5% of the total volume of vinyltrimethoxysilane and trimethoxysilane.

7. The solvent-free dealcoholization anti-fouling flashover coating according to claim 1, characterized in that: The conditions of the cross-linking reaction are: stirring at 70-80° C. for 5-6 hours, and then distilling at 100° C. for 2-4 hours.

8. The solvent-free dealcoholization anti-fouling flashover coating according to claim 1, characterized in that: The alkoxy silicone oil is one or more of terminal hydrogen-containing polysiloxane, terminal methoxyvinyl polysiloxane, terminal methoxy fluorine-containing polysiloxane, and terminal methoxy polydimethylsiloxane.

9. The solvent-free dealcoholization anti-fouling flashover coating according to claim 1, characterized in that: The filler is one or more of nano titanium dioxide, aluminum hydroxide, iron hydroxide, white carbon black, silicon carbide, aluminum oxide, aluminum nitride, plaster of Paris, boron nitride, silicon carbide, clay, silicon micropowder, asbestos wool or calcium carbonate.

10. A method for preparing a solvent-free dealcoholization anti-fouling flashover coating containing a hyperbranched crosslinking agent according to any one of claims 1 to 9, characterized in that: The method comprises the following steps: adding filler into alkoxy silicone oil and stirring fully, then adding structure control agent to prevent structuring, continuously adding coupling agent, hyperbranched crosslinking agent, curing accelerator and catalyst and stirring fully, and finally filtering to obtain solvent-free dealcoholization anti-fouling flashover coating containing hyperbranched crosslinking agent.

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