Anti-aging organic silicon insulating waterproof coating as well as preparation method and application thereof

Abstract

The invention belongs to the technical field of organic silicon coatings, and discloses an anti-aging organic silicon insulating waterproof coating as well as a preparation method and application thereof. The preparation method comprises the following steps: carrying out mixed reaction on a hydrogen-containing ring body and a vinyl silane coupling agent under the condition of a hydrosilylation catalyst to obtain a cyclosiloxane cross-linking agent; and uniformly mixing the obtained cyclosiloxane cross-linking agent with alpha, omega-dihydroxy polysiloxane, polydimethylsiloxane, a dialkoxy epoxy silane coupling agent, fumed silica, an antistatic agent, fluorine-containing silicon resin, a catalyst and solvent oil in a protective atmosphere to obtain the anti-aging organic silicon insulating waterproof coating. Compared with the conventional alkoxy silane cross-linking agent and ketoxime silane cross-linking agent, the specific cyclosiloxane cross-linking agent adopted by the invention can obviously improve the mechanical properties, weather resistance and storage stability of the obtained organic silicon coating.

Description

Technical Field

[0001] The invention belongs to the technical field of organic silicon coatings, and in particular relates to an anti-aging organic silicon insulating waterproof coating and a preparation method and application thereof. Background Art

[0002] The use environment of the meter box is relatively harsh, and the meter box needs to have certain anti-corrosion and anti-rust properties. At present, some appropriate surface treatment methods are generally used, such as applying a layer of insulating coating on the surface for surface modification, but the existing insulating coating has poor aging and oxidation resistance, and the service life of the meter box after coating is limited. In order to reduce costs, increase the utilization rate of the meter box, and improve the safety factor, it is urgent to improve the surface treatment technology of the meter box.

[0003] Organic silicon coating has good application prospects in the surface treatment of electric meter boxes due to its good weather resistance, hydrophobicity and insulation. Patent CN 105176387 A discloses an enhanced solvent-free heat-resistant organic silicon insulating varnish, which is prepared from the following components in parts by weight: 40-50 parts of hydrogen-containing silicone oil, 44.996-49.994 parts of modified hydroxy silicone oil, 5-10 parts of modified nano-silicon dioxide, and 0.004-0.006 parts of chloroplatinum. The organic silicon insulating varnish adopts addition-type silicone rubber, and special modified hydroxy silicone oil needs to be prepared, which is costly. Patent CN 102559047 A discloses an organic silicon coating, which is composed of dihydroxy polydimethylsiloxane, MQ resin, white carbon black, vulcanization accelerator, methyl trisbutyl ketoxime silane, vinyl trisbutyl ketoxime silane, propylamino triethoxy silane, 3-glycidyl ether oxypropyl trimethoxy silane and solvent components. The use of deketoxime type cross-linking agent has high cost and is corrosive to the copper substrate, which has a certain impact on its application.

[0004] Dealcoholized silicone rubber is widely used in silicone coatings because it has good adhesion to the substrate after vulcanization, is non-corrosive, and has good physical and mechanical properties, electrical properties, and low cost. At present, the crosslinking agents used in dealcoholized silicone coatings are generally small molecular orthosilicates and trialkoxysilanes. However, the above crosslinking agents have a strong tendency to self-polymerize, causing them to gradually lose their crosslinking properties during storage. At the same time, excessive self-polymerization also reduces the crosslinking strength of the hydroxyl polysiloxane body, resulting in a significant decrease in the mechanical properties and weather resistance of the resulting coating. Summary of the invention

[0005] In view of the shortcomings and deficiencies of the above prior art, the primary purpose of the present invention is to provide a method for preparing an aging-resistant organic silicon insulating waterproof coating.

[0006] Another object of the present invention is to provide an aging-resistant organic silicon insulating waterproof coating prepared by the above method.

[0007] Another object of the present invention is to provide application of the above-mentioned aging-resistant organic silicon insulating waterproof coating in surface treatment of power equipment.

[0008] The purpose of the present invention is achieved through the following technical solutions:

[0009] A method for preparing an aging-resistant organic silicon insulating waterproof coating comprises the following preparation steps:

[0010] (1) mixing a hydrogen-containing ring body with a vinyl silane coupling agent under a hydrosilylation catalyst to obtain a cyclosiloxane crosslinking agent;

[0011] (2) The obtained cyclosiloxane crosslinking agent is mixed evenly with α,ω-dihydroxypolysiloxane, polydimethylsiloxane, dialkoxyepoxysilane coupling agent, fumed silica, antistatic agent, fluorine-containing silicone resin, catalyst and solvent oil under a protective atmosphere to obtain an aging-resistant organic silicone insulating waterproof coating.

[0012] Furthermore, the hydrogen-containing ring body in step (1) is preferably tetramethylhydrogencyclotetrasiloxane (D4H) or pentamethylhydrogencyclopentasiloxane (D5H).

[0013] Furthermore, the molar ratio of the hydrogen-containing ring body to the vinyl silane coupling agent in step (1) is preferably 1:2-5.

[0014] Furthermore, the vinyl silane coupling agent in step (1) is preferably vinyl trimethoxy silane or vinyl triethoxy silane.

[0015] Furthermore, the mixed reaction in step (1) is carried out under solvent-free conditions or anhydrous solvent conditions, and the anhydrous solvent is preferably one or a mixed solvent of two or more selected from ethanol, isopropanol, acetone, benzene, toluene, ethyl acetate, cyclohexane, dimethylformamide, and dimethyl sulfoxide.

[0016] Furthermore, the hydrosilylation catalyst in step (1) is an isopropanol solution of chloroplatinic acid (Speier catalyst) or a vinyl platinum complex (Karstedt's catalyst).

[0017] Furthermore, the temperature of the mixed reaction in step (1) is 70 to 90° C., and the time is 2 to 8 hours.

[0018] Furthermore, the viscosity of the α,ω-dihydroxypolysiloxane in step (2) is preferably 50 to 150 mPa.s (25° C.).

[0019] Furthermore, the viscosity of the polydimethylsiloxane in step (2) is preferably 1000 to 5000 mPa.s (25° C.).

[0020] Furthermore, the dialkoxy epoxy silane coupling agent in step (2) is at least one of γ-glycidyloxypropylmethyldimethoxysilane and γ-glycidyloxypropylmethyldiethoxysilane.

[0021] Furthermore, the antistatic agent in step (2) is preferably at least one of stearamidopropyl hydroxyethyl quaternary ammonium nitrate, alkyl dicarboxymethyl ammonium betaine, and dodecyl dimethyl quaternary betaine.

[0022] Furthermore, the fluorine-containing silicone resin in step (2) is preferably polymethyl nonafluorohexylsiloxane.

[0023] Furthermore, the catalyst in step (2) is preferably a compound of a titanate catalyst and an organic tin catalyst.

[0024] Furthermore, the solvent oil in step (2) is preferably 120# solvent oil.

[0025] Furthermore, the weight proportions of the materials in step (2) are as follows:

[0026] 50-150 parts of α,ω-dihydroxypolysiloxane, 2-10 parts of polydimethylsiloxane, 1-5 parts of dialkoxyepoxysilane coupling agent, 20-40 parts of fumed silica, 0.2-2 parts of antistatic agent, 20-50 parts of fluorine-containing silicone resin, 2-5 parts of cyclosiloxane crosslinking agent, 0.01-0.05 parts of catalyst, and 100-300 parts of solvent oil.

[0027] An aging-resistant organic silicon insulating waterproof coating is prepared by the method.

[0028] Application of the above-mentioned aging-resistant silicone insulating waterproof coating in surface treatment of power equipment.

[0029] Compared with the prior art, the present invention has the following beneficial effects:

[0030] The present invention adopts a specific cyclosiloxane crosslinking agent as the crosslinking agent of the hydroxy silicone oil, and its synthesis route and molecular structure are as follows Figure 1As shown (under the condition that the molar ratio of D4H to the vinyl silane coupling agent is 1:4). The crosslinking agent has a central structure of cyclosiloxane and an alkoxy dealcohol-type crosslinking structure distributed around it. The central structure of the cyclosiloxane can effectively enhance the reaction steric hindrance between the crosslinking agent molecules and enhance the compatibility with α,ω-dihydroxy polysiloxane; and the increase in the number of alkoxy groups distributed around it is conducive to improving the reaction activity with low steric hindrance linear α,ω-dihydroxy polysiloxane. Through the above comprehensive effect, the self-polymerization tendency of the crosslinking agent is significantly reduced and the crosslinking efficiency with the linear α,ω-dihydroxy polysiloxane is improved, thereby improving the storage stability of the obtained coating composition and improving the mechanical properties and weather resistance of the obtained coating film. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Figure 1 The synthetic route of the cyclosiloxane crosslinking agent of the present invention is shown in FIG. DETAILED DESCRIPTION

[0032] The present invention is further described in detail below in conjunction with examples, but the embodiments of the present invention are not limited thereto.

[0033] Example 1

[0034] A method for preparing an aging-resistant organic silicon insulating waterproof coating comprises the following preparation steps:

[0035] (1) D4H and vinyl trimethoxysilane were added to a reactor in a molar ratio of 1:4 and mixed evenly. After nitrogen substitution, the temperature was raised to 70-80° C., Speier catalyst was added dropwise and stirred for 4 hours. The vinyl content in the product was sampled and the addition reaction rate was calculated to be 98.6%. The temperature was raised to 100-110° C. and the residual solvent and unreacted raw materials were removed in vacuo to obtain a cyclosiloxane crosslinking agent.

[0036] (2) Weigh each component by weight, and mix 4 parts of cyclosiloxane crosslinker with 100 parts of α,ω-dihydroxypolysiloxane with a viscosity of 100 mPa.s, 6 parts of polydimethylsiloxane with a viscosity of 3000 mPa.s, 3 parts of γ-glycidyloxypropylmethyldiethoxysilane, 30 parts of fumed silica, 1 part of stearylamidopropyl hydroxyethyl quaternary ammonium nitrate, 30 parts of polymethyl nonafluorohexylsiloxane, 0.02 parts of dibutyltin dilaurate, 0.01 parts of tetraisopropyl titanate and 200 parts of 120# solvent oil under nitrogen protection to obtain an aging-resistant silicone insulating waterproof coating with a viscosity of 116 mPa.s.

[0037] Example 2

[0038] A method for preparing an aging-resistant organic silicon insulating waterproof coating comprises the following preparation steps:

[0039] (1) D4H and vinyl trimethoxysilane were added to a reactor in a molar ratio of 1:3 and mixed evenly. After nitrogen substitution, the temperature was raised to 75-85° C., Speier catalyst was added dropwise and stirred for reaction for 3 h. The vinyl content in the product was sampled and the addition reaction rate was calculated to be 99.1%. The temperature was raised to 100-110° C. and the residual solvent and unreacted raw materials were removed in vacuo to obtain a cyclosiloxane crosslinking agent.

[0040] (2) Weigh each component by weight, and mix 5 parts of cyclosiloxane crosslinker with 150 parts of α,ω-dihydroxypolysiloxane with a viscosity of 150 mPa.s, 2 parts of polydimethylsiloxane with a viscosity of 1000 mPa.s, 3 parts of γ-glycidyloxypropylmethyldiethoxysilane, 40 parts of fumed silica, 1 part of stearylamide propyl hydroxyethyl quaternary ammonium nitrate, 20 parts of polymethyl nonafluorohexylsiloxane, 0.02 parts of dibutyltin dilaurate, 0.01 parts of tetraisopropyl titanate and 300 parts of 120# solvent oil under nitrogen protection to obtain an aging-resistant silicone insulating waterproof coating with a viscosity of 125 mPa.s.

[0041] Example 3

[0042] A method for preparing an aging-resistant organic silicon insulating waterproof coating comprises the following preparation steps:

[0043] (1) D4H and vinyl triethoxysilane were added to a reactor in a molar ratio of 1:2 and mixed evenly. After nitrogen substitution, the temperature was raised to 80-90° C., Speier catalyst was added dropwise and stirred for 2 h. The vinyl content in the product was sampled and the addition reaction rate was calculated to be 99.4%. The temperature was raised to 110-120° C. and the residual solvent and unreacted raw materials were removed in vacuo to obtain a cyclosiloxane crosslinking agent.

[0044] (2) Weigh each component by weight, and mix 2 parts of cyclosiloxane crosslinker with 50 parts of α,ω-dihydroxypolysiloxane with a viscosity of 50 mPa.s, 10 parts of polydimethylsiloxane with a viscosity of 5000 mPa.s, 3 parts of γ-glycidyloxypropylmethyldiethoxysilane, 20 parts of fumed silica, 1 part of stearamidopropyl hydroxyethyl quaternary ammonium nitrate, 40 parts of polymethyl nonafluorohexylsiloxane, 0.02 parts of dibutyltin dilaurate, 0.01 parts of tetraisopropyl titanate and 100 parts of 120# solvent oil under nitrogen protection to obtain an aging-resistant silicone insulating waterproof coating with a viscosity of 132 mPa.s.

[0045] Example 4

[0046] A method for preparing an aging-resistant organic silicon insulating waterproof coating comprises the following preparation steps:

[0047] (1) D5H, vinyl trimethoxysilane and isopropanol solvent are added to a reactor and mixed evenly, wherein the molar ratio of D5H to vinyl trimethoxysilane is 1:5, and the volume ratio of the added amount of isopropanol solvent to D5H is 1:1. After nitrogen substitution, the temperature is raised to 75-80° C., Speier catalyst is added dropwise and stirred for reaction for 5 hours, and the vinyl content in the product is sampled and detected. The addition reaction rate is calculated to be 97.9%, and the temperature is raised to 100-110° C. and the solvent and unreacted raw materials are removed in vacuo to obtain a cyclosiloxane crosslinking agent.

[0048] (2) Weigh each component by weight, and mix 4 parts of cyclosiloxane crosslinker with 100 parts of α,ω-dihydroxypolysiloxane with a viscosity of 100 mPa.s, 6 parts of polydimethylsiloxane with a viscosity of 3000 mPa.s, 3 parts of γ-glycidyloxypropylmethyldiethoxysilane, 30 parts of fumed silica, 1 part of stearylamide propyl hydroxyethyl quaternary ammonium nitrate, 30 parts of polymethyl nonafluorohexylsiloxane, 0.02 parts of dibutyltin dilaurate, 0.01 parts of tetraisopropyl titanate and 200 parts of 120# solvent oil under nitrogen protection to obtain an aging-resistant silicone insulating waterproof coating with a viscosity of 115 mPa.s.

[0049] Comparative Example 1

[0050] A method for preparing an aging-resistant organic silicon insulating waterproof coating. Compared with Example 1, an equal amount of vinyl trimethoxy silane cross-linking agent is used to replace a cyclosiloxane cross-linking agent in the preparation of the coating.

[0051] Comparative Example 2

[0052] A method for preparing an aging-resistant organic silicon insulating waterproof coating. Compared with Example 1, an equal amount of vinyl trisbutyl ketone oxime silane crosslinking agent is used to replace a cyclosiloxane crosslinking agent in the preparation of the coating.

[0053] The mechanical properties (GB / T 528-2009), weather resistance (mechanical property retention rate was tested after 600 hours of artificial weather aging (exposure to fluorescent ultraviolet rays and water)) and storage stability (the coating sample was sealed and placed in an 80°C oven for accelerated aging for 48 hours, then taken out and placed under standard conditions (temperature 25°C, relative humidity 55%) for cooling for 24 hours and then the mechanical properties after curing were tested) of the organic silicone insulating waterproof coatings obtained in the above embodiments and comparative examples. The results are shown in Table 1 below.

[0054] Table 1

[0055]

[0056] It can be seen from the results in Table 1 that the specific cyclosiloxane crosslinking agent used in the present invention can significantly improve the mechanical properties, weather resistance and storage stability of the obtained silicone coating compared with conventional alkoxysilane crosslinking agents and ketoxime silane crosslinking agents.

[0057] The above embodiments are preferred implementation modes of the present invention, but the implementation modes of the present invention are not limited to the above embodiments. Any other changes, modifications, substitutions, combinations, and simplifications that do not deviate from the spirit and principles of the present invention should be equivalent replacement methods and are included in the protection scope of the present invention.

Claims

1. A method for preparing an aging-resistant organic silicon insulating waterproof coating, characterized in that: The method comprises the following preparation steps: (1) mixing a hydrogen-containing ring body with a vinyl silane coupling agent under a hydrosilylation catalyst to obtain a cyclosiloxane crosslinking agent; (2) The obtained cyclosiloxane crosslinking agent is mixed evenly with α,ω-dihydroxypolysiloxane, polydimethylsiloxane, dialkoxyepoxysilane coupling agent, fumed silica, antistatic agent, fluorine-containing silicone resin, catalyst and solvent oil under a protective atmosphere to obtain an aging-resistant organic silicone insulating waterproof coating.

2. The method for preparing an aging-resistant organic silicon insulating waterproof coating according to claim 1, characterized in that: The hydrogen-containing ring body in step (1) is tetramethylhydrogencyclotetrasiloxane or pentamethylhydrogencyclopentasiloxane; the molar ratio of the hydrogen-containing ring body to the vinyl silane coupling agent is 1:2-5.

3. The method for preparing an aging-resistant organic silicon insulating waterproof coating according to claim 1, characterized in that: The vinyl silane coupling agent in step (1) is vinyl trimethoxy silane or vinyl triethoxy silane.

4. The method for preparing an aging-resistant organic silicon insulating waterproof coating according to claim 1, characterized in that: The mixed reaction in step (1) is carried out under solvent-free conditions or anhydrous solvent conditions, and the anhydrous solvent is one or a mixed solvent of two or more selected from ethanol, isopropanol, acetone, benzene, toluene, ethyl acetate, cyclohexane, dimethylformamide, and dimethyl sulfoxide.

5. The method for preparing an aging-resistant organic silicon insulating waterproof coating according to claim 1, characterized in that: The hydrosilylation catalyst in step (1) is a Speier catalyst or a Karstedt's catalyst; the temperature of the mixed reaction is 70 to 90° C. and the time is 2 to 8 hours.

6. The method for preparing an aging-resistant organic silicon insulating waterproof coating according to claim 1, characterized in that: The viscosity of the α,ω-dihydroxy polysiloxane in step (2) is 50-150 mPa.s; the viscosity of the polydimethylsiloxane is 1000-5000 mPa.s.

7. The method for preparing an aging-resistant organic silicon insulating waterproof coating according to claim 1, characterized in that: The dialkoxy epoxy silane coupling agent in step (2) is at least one of γ-glycidyloxypropylmethyldimethoxysilane and γ-glycidyloxypropylmethyldiethoxysilane; the antistatic agent is at least one of stearamidopropyl hydroxyethyl quaternary ammonium nitrate, alkyl dicarboxymethyl ammonium ethyl lactone, and dodecyl dimethyl quaternary ethyl lactone; the fluorine-containing silicone resin is polymethyl nonafluorohexylsiloxane; the catalyst is a compound of a titanate catalyst and an organic tin catalyst; and the solvent oil is 120# solvent oil.

8. A method for preparing an aging-resistant organic silicon insulating waterproof coating according to any one of claims 1 to 7, characterized in that: The weight proportions of the materials in step (2) are as follows: 50-150 parts of α,ω-dihydroxypolysiloxane, 2-10 parts of polydimethylsiloxane, 1-5 parts of dialkoxyepoxysilane coupling agent, 20-40 parts of fumed silica, 0.2-2 parts of antistatic agent, 20-50 parts of fluorine-containing silicone resin, 2-5 parts of cyclosiloxane crosslinking agent, 0.01-0.05 parts of catalyst, and 100-300 parts of solvent oil.

9. An aging-resistant organic silicon insulating waterproof coating, characterized in that: It is prepared by the method according to any one of claims 1 to 8.

10. Use of the aging-resistant organic silicon insulating waterproof coating according to claim 9 in the surface treatment of power equipment.

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