High-thermal-conductivity and high-heat-resistance environment-friendly impregnating resin paint and preparation method thereof

Abstract

The invention belongs to the field of high polymer materials, and discloses high-thermal-conductivity and high-heat-resistance environment-friendly impregnating resin paint and a preparation method thereof. The high-thermal-conductivity and high-heat-resistance type environment-friendly impregnating resin paint is prepared from the following components in percentage by weight: 40 to 70 percent of silicon-based modified pulp, 0.3 percent of hydroquinone polymerization inhibitor, 0.5 to 3 percent of molecular weight regulator, 1.7 percent of wetting flatting agent, 1.8 percent of catalyst, 22.1 to 52.1 percent of allyl ester active agent and 1.6 percent of cross-linking agent, the silicon-based modified slurry is prepared from the following components: 20-50% of polyester imide resin, 14% of an acrylic ester active agent, 35-65% of a heat-conducting filler, 0.5% of a rheology modifier and 0.5% of a dispersing agent, and the silicon-based modified slurry is prepared by the following steps: sequentially putting all the raw materials into a stirrer, and stirring, homogenizing and dispersing to obtain the silicon-based modified slurry. The impregnating resin paint has the advantages of high heat conductivity, high heat resistance and the like.

Description

Technical Field

[0001] The present invention belongs to the field of polymer materials, and in particular relates to a high-thermal-conductivity and high-heat-resistance environmentally friendly impregnating resin paint and a preparation method thereof. Background Art

[0002] Insulating varnish is a functional coating made with polymer resin as the main film-forming substance by adding solvents, additives and functional fillers. Its core function is to provide insulation protection for electrical / electronic components to prevent current leakage, arc discharge or short circuit. At the same time, it has the characteristics of heat resistance, moisture resistance, corrosion resistance, etc. to ensure long-term and stable operation of equipment.

[0003] Existing insulating varnish products suffer from numerous issues, including weak adhesion to the substrate and low filling efficiency. This makes it difficult to completely fill the tiny pores within the material, creating "weak zones" within the insulation layer. This inefficient thermal conductivity of the insulation layer leads to heat accumulation, exacerbating abnormal temperature rises in equipment. This insufficient filling rate and accumulated temperature rise further limit the insulating varnish's heat resistance. When heat cannot be effectively dissipated, the material is susceptible to aging due to prolonged exposure to high temperatures, ultimately reducing its heat resistance and shortening the equipment's lifespan.

[0004] Most existing resin insulating varnishes have high viscosity and use organic solvents in the preparation process. They can only withstand heat of around 180°C or below. Some even use epoxy and anhydride as raw material components, which are unstable and have high viscosity coefficients. Summary of the Invention

[0005] The present invention aims to solve the above technical problems and provide an environmentally friendly insulating varnish with high thermal conductivity, high heat resistance and comprehensive performance.

[0006] In order to achieve the above-mentioned object of the invention, the present invention provides the following technical solutions: In the first aspect, the present invention provides a high thermal conductivity and high heat resistance environmentally friendly impregnating resin paint, which is composed of the following components by weight: 40-70% silicon-based modified slurry, 0.3% hydroquinone inhibitor, 0.5-3% molecular weight regulator, 1.7% wetting and leveling agent, 1.8% catalyst, 22.1-52.1% acrylate active agent, and 1.6% crosslinking agent.

[0007] The silicon-based modified slurry is composed of the following components by weight: 20-50% polyester imide resin, 14% propylene ester active agent, 35-65% thermal conductive filler, 0.5% rheology regulator, and 0.5% dispersant; The silicon-based modified slurry is prepared by the following steps: all raw materials are sequentially put into a stirrer, stirred and homogeneously dispersed, and the silicon-based modified slurry is obtained.

[0008] Preferably, during the preparation of the silicon-based modified slurry, the stirring speed is 600-1000 rpm and the stirring time is 60-120 minutes.

[0009] Preferably, the molecular weight regulator is α-methylstyrene dimer.

[0010] Preferably, the wetting and leveling agent is TEGO 4100.

[0011] Preferably, the catalyst is an isooctanoate. More preferably, the catalyst is one or more of manganese isooctanoate, copper isooctanoate, and iron isooctanoate.

[0012] Preferably, the crosslinking agent is a peroxide, more preferably one or more of 3,3-bis(tert-butylperoxy)-3,3,5-trimethylcyclohexane, dicumyl peroxide (DCP), tert-butylbenzene peroxide (TBPB), and benzoyl peroxide (PBO).

[0013] Preferably, the thermally conductive filler is one or more of nano- or micron-sized silicon dioxide, fumed silicon dioxide, aluminum oxide powder, boron nitride, and magnesium oxide.

[0014] Preferably, the rheology regulator is one or more of bentonite, silicate, anti-settling wax, and polyurea.

[0015] Preferably, the dispersant is a high molecular weight copolymer alkylammonium salt, more preferably one or more of BYK-9076, BYK-190, and BYK-26475.

[0016] Preferably, the acrylic ester active agent is one or more of 2-hydroxyethyl methacrylate, 1-ethylene glycol-2-methacrylate, 2-ethylene glycol-2-methacrylate, 3-ethylene glycol-2-methacrylate, hexanediol diacrylate (HDDA), and diallyl phthalate (DAP).

[0017] In a second aspect, the present invention provides a method for preparing the high thermal conductivity and high heat resistance environmentally friendly impregnating resin varnish of the present invention, comprising the following steps: S1. Add hydroquinone polymerization inhibitor, molecular weight regulator and wetting and leveling agent to the silicon-based modified slurry, disperse and shear the mixture, heat it up, cool it down to below 40°C, and then add catalyst and cross-linking agent and mix them evenly; S2. Add acrylic acid ester active agent, filter and discharge.

[0018] Preferably, in step S1, the dispersion speed is 600-1000 rpm, and the dispersion time is 30-60 minutes.

[0019] Preferably, in step S1, the temperature is raised to 70-80° C. and kept warm for 30 minutes to 1 hour.

[0020] Preferably, the silicon-based modified slurry is prepared by the following steps: all raw materials are mixed and then stirred to disperse uniformly.

[0021] Preferably, the stirring and dispersing speed is 600 to 1000 rpm, and the dispersing time is preferably 60 to 120 minutes.

[0022] The polyester resin is imidized to improve the heat resistance of the resin. The molecular weight regulator expands the branch chain, increases the molecular weight and film density and toughness, improves the corrosion resistance, and improves the bonding strength and insulation electrical strength. The wetting and leveling agent improves the surface tension, improves the permeability and thermal conductivity. The acrylate surfactant adjusts the viscosity and participates in the curing to reduce shrinkage. The cross-linking agent triggers ring opening below 120°C and gels at 100-110°C, greatly improving the amount of paint applied and the filling of the motor winding, further improving the thermal conductivity and reducing the temperature rise of the motor. The thermally conductive filler improves the thermal conductivity and the heat resistance level of the film, making it heat-resistant to more than 220°C. The dispersant improves the coating ability of the thermally conductive filler and the resin.

[0023] Compared with the existing technology, the present invention introduces a thermal conductive material, an acrylic ester active agent and an unsaturated polyesterimide resin to react to obtain an environmentally friendly, solvent-free, VOC-free, non-flammable and non-explosive high-solid, low-viscosity insulating impregnation resin. The components work synergistically to significantly improve thermal conductivity and heat resistance, while also taking into account good adhesion, toughness, bonding strength and electrical strength, and having excellent comprehensive performance. DETAILED DESCRIPTION

[0024] The technical solution of the present invention is further described below with reference to specific embodiments, but the present invention is not limited to the following embodiments.

[0025] Unless otherwise specified, the instruments and reagents used in the examples are conventional instruments and reagents in the art and are commercially available. Unless otherwise specified, the specific experimental procedures involved herein are understood or known to those of ordinary skill in the art based on their common knowledge or conventional techniques, and are not described in detail here.

[0026] The preparation method of polyesterimide resin is as follows: 50g of neopentyl glycol, 45g of propylene glycol, 35g of tris(2-hydroxyethyl)isocyanurate, 60g of terephthalic acid and 0.5g of butyl orthotitanate were added to the reaction flask, and the temperature was raised until the materials melted and stirring was started; the temperature was raised to 200°C and maintained at this temperature for reaction until the material system became clear and the acid value was less than 10mgKOH / g, and then the temperature was lowered; when the temperature dropped to 160°C, 100g of trimellitic anhydride and 100g of diaminodiphenylmethane were added. The mixture was heated to 200°C and maintained at this temperature for reaction until the acid value reached 60 mgKOH / g. The mixture was then vacuumed and the residual solvent was removed under reduced pressure, and the temperature was lowered. When the temperature dropped to 150°C, 140 g of ethylene glycol butyl ether was added. When the temperature dropped below 60°C, 33 g of a water-based amino resin methyl etherified melamine resin was added. The pH was adjusted to 7.0-9.0 with 25 g of dimethylethanolamine as a neutralizer to obtain a water-soluble polyesterimide resin. The water-soluble resin was a viscous, transparent liquid with a solid content of 70%.

[0027] α-Methylstyrene dimer is a commercially available product.

[0028] Dispersants BYK-9076, BYK-190, and BYK-26475 are commercially available products purchased from BYK, Germany.

[0029] The wetting and leveling agent TEGO 4100 is a commercially available product purchased from German company Digo.

[0030] Example 1 1. Preparation of silicon-based modified slurry (1) Prepare the following raw material components by weight percentage: Polyesterimide resin 50%; 3-Ethylene glycol-2-methacrylate 14%; Nano-silicon dioxide 35%; Bentonite 0.5%; Dispersant BYK-9076 0.5%.

[0031] (2) All the raw materials were put into the blender in turn, stirred and dispersed at a speed of 600 rpm for 120 minutes to obtain a silicon-based modified slurry.

[0032] 2. Preparation of environmentally friendly impregnating resin paint (1) Prepare the following raw material components by weight percentage: Silicon-based modified slurry 40%; Hydroquinone polymerization inhibitor 0.3%; α-Methylstyrene dimer 0.5%; Wetting and leveling agent TEGO 4100 1.7%; Manganese 2-ethylhexanoate 1.8%; 2-Hydroxyethyl methacrylate 52.1%; 3,3-Bis(tert-butylperoxy)-3,3,5-trimethylcyclohexane 1.6%.

[0033] (2) Add polymerization inhibitor, molecular weight regulator, and wetting and leveling agent to the silicon-based modified slurry, and disperse and shear the mixture at a speed of 600 rpm for 60 minutes. Heat to 70°C and hold for 1 hour. Cool to below 40°C and add catalyst and crosslinker to mix evenly. Add acrylate surfactant to adjust viscosity and participate in curing to reduce shrinkage. Filter and discharge. Testing shows that the solid content of the finished product is 99.1% and the viscosity is less than 30 mPa·s (23±0.5°C).

[0034] Example 2 1. Preparation of silicon-based modified slurry (1) Prepare the following raw materials: Polyesterimide resin 30%; 1-Ethylene glycol-2-methacrylate 14%; Boron nitride 55%; Polyurea 0.5%; Dispersant BYK-190 0.5%.

[0035] (2) All raw materials were put into a stirrer in sequence, stirred and homogenized at a speed of 800 rpm for 80 minutes to obtain a silicon-based modified slurry.

[0036] 2. Preparation of environmentally friendly impregnating resin paint (1) Prepare the following raw material components by weight percentage: Silicon-based modified slurry 50%; Hydroquinone polymerization inhibitor 0.3%; α-Methylstyrene dimer 2%; Wetting and leveling agent TEGO 4100 1.7%; Copper octanoate 1.8%; 2-Hydroxyethyl methacrylate 42.1%; Dicumyl peroxide 1.6%.

[0037] (2) Add polymerization inhibitor, molecular weight regulator, and wetting and leveling agent to the silicon-based modified slurry, and disperse and shear the mixture at a speed of 800 rpm for 50 minutes. Heat to 75°C and hold for 45 minutes. Cool to below 40°C and add catalyst and crosslinker to mix evenly. Add acrylate surfactant to adjust viscosity and participate in curing to reduce shrinkage. Filter and discharge. Testing shows that the solid content of the finished product is 99.3% and the viscosity is less than 30 mPa·s (23±0.5°C).

[0038] Example 3 1. Preparation of silicon-based modified slurry (1) Prepare the following raw materials: Polyesterimide resin 20%; 2-Ethylene glycol-2-methacrylate 14%; Alumina powder 65%; Silicate 0.5%; Dispersant BYK-26475 0.5%.

[0039] (2) All raw materials were put into a stirrer in sequence, stirred and homogenized at a speed of 1000 rpm for 60 minutes to obtain a silicon-based modified slurry.

[0040] 2. Preparation of environmentally friendly impregnating resin paint (1) Prepare the following raw material components by weight percentage: Silicon-based modified slurry 70%; Hydroquinone polymerization inhibitor 0.3%; α-Methylstyrene dimer 3%; Wetting and leveling agent TEGO 4100 1.7%; Iron 2-octanoate 1.8%; 2-Hydroxyethyl methacrylate 22.1%; Tert-butylbenzene peroxide 1.6%.

[0041] (2) Add a polymerization inhibitor, molecular weight regulator, and wetting and leveling agent to the silicon-based modified slurry, and disperse and shear the mixture at a speed of 1000 rpm for 30 minutes. Heat the mixture to 80°C and hold for 30 minutes. Cool the mixture to below 40°C and add a catalyst and crosslinking agent to mix evenly. Add an acrylic ester surfactant to adjust the viscosity and simultaneously participate in the curing to reduce shrinkage. Filter and discharge the mixture. Testing shows that the solid content of the finished product is 99.7% and the viscosity is less than 30 mPa·s (23±0.5°C).

[0042] Comparative Example 1. Prepare the following resin paint raw material component formula by weight percentage: Polyesterimide resin 55%; Hydroquinone polymerization inhibitor 0.3%; α-Methylstyrene dimer 2.5%; Wetting and leveling agent TEGO 4100 1.7%; Copper octanoate 1.8%; 2-Hydroxyethyl methacrylate 37.1%; Dicumyl peroxide 1.6%.

[0043] 2. The preparation steps are as follows: Add polymerization inhibitor, molecular weight regulator and wetting and leveling agent to polyesterimide resin, disperse and shear the mixture at a dispersion speed of 800 rpm for 50 minutes, heat to 70°C and keep warm for 1 hour, cool to below 40°C, add catalyst and cross-linking agent and mix evenly; add acrylate active agent to adjust viscosity, filter and discharge.

[0044] Product performance testing The impregnated resin varnishes prepared in the above Examples 1-3 and the comparative example were tested to examine their various properties.

[0045] 1. VOC detection Test method: GB / T 23985-2009 "Paints and varnishes - Determination of volatile organic compound (VOC) content - Difference method" Test results: After testing, the impregnating resin paints of Examples 1-3 had no VOC volatilization.

[0046] 2. Microwave temperature rise detection The microwave temperature rise test is used to detect the temperature rise of the winding impregnated with insulating varnish.

[0047] Test results: The temperature rise results of Examples 1-3 and the comparative example samples are shown in Table 1.

[0048] Table 1. Microwave temperature rise test results

[0049] As can be seen from Table 1, compared with the comparative example, the temperature rise results of the windings impregnated with the insulating varnish of Examples 1-3 are reduced, indicating that they have good heat dissipation performance, excellent thermal conductivity, less energy loss, and are more conducive to electrical stability.

[0050] 3. Heat resistance test Test method: GB / T 27761-2011 "Test method for weight loss and residual amount by thermogravimetric analyzer" Test results: Using the impregnating resin varnishes of Examples 1-3, the heat resistance of the motor winding system was increased from 180°C before modification (comparative example) to ≥220°C, and even as high as 260°C. The product did not soften, crack, or carbonize, and the TGA was ≥270°C. The results are shown in Table 2 below.

[0051] Table 2. Heat resistance results

[0052] 4. Testing of bonding strength and electrical properties Test method: GB / T 7354-2018 "High voltage test technology partial discharge measurement" GB / T 1981.2-2009 "Electrical insulating paints Part 2: Test methods" Test results: The test results of the impregnated resin paints of Examples 1-3 and the comparative example are shown in Table 3 below.

[0053] Table 3. Bond strength and electrical performance results

[0054] As shown in Table 3, the bonding strength of the resin paints of Examples 1-3 is higher than that of the comparative example. The electrical strength and PDIV partial discharge values show that the insulating paint of the present invention has a relatively high electrical strength. High electrical strength means that the insulating paint can withstand higher voltages without being broken down, has excellent insulation performance, effectively prevents current leakage and short circuits, and ensures the safe operation of the equipment. Compared with the comparative example, the voltage resistance of Examples 1-3 is stronger, which enables electronic equipment to operate in more severe voltage environments, thereby improving the reliability and service life of the equipment. In addition, compared with the comparative example, the PDIV partial discharge starting voltage of Examples 1-3 is also higher, which shows that it has excellent corona resistance. The above-mentioned electrical performance test results show that the insulating paint of the present invention has excellent performance in terms of insulation performance, voltage resistance, corona resistance, insulation stability and anti-interference ability, and can ensure the safe, stable and reliable operation of electronic equipment.

[0055] The above description is only a preferred embodiment of the present invention and does not limit the present invention in any form. Therefore, any simple modification, equivalent change and modification made to the above embodiment based on the technical essence of the present invention without departing from the content of the technical solution of the present invention shall still fall within the scope of the technical solution of the present invention.

Claims

1. A high thermal conductivity and high heat resistance environmentally friendly impregnating resin paint, characterized in that, The composition is as follows by weight: silicon-based modified slurry 40-70%, hydroquinone polymerization inhibitor 0.3%, molecular weight regulator 0.5-3%, wetting and leveling agent 1.7%, catalyst 1.8%, propylene ester active agent 22.1-52.1%, crosslinking agent 1.6%; The silicon-based modified slurry is composed of the following components by weight: 20-50% polyester imide resin, 14% propylene ester active agent, 35-65% thermal conductive filler, 0.5% rheology regulator, and 0.5% dispersant; The silicon-based modified slurry is prepared by the following steps: all raw materials are sequentially put into a stirrer, stirred and homogeneously dispersed, and the silicon-based modified slurry is obtained.

2. The high thermal conductivity and high heat resistance environmentally friendly impregnating resin paint according to claim 1, characterized in that: The acrylate active agent is one or more of 2-hydroxyethyl methacrylate, 1-ethylene glycol-2-methacrylate, 2-ethylene glycol-2-methacrylate, 3-ethylene glycol-2-methacrylate, hexanediol diacrylate, and diallyl phthalate.

3. The high thermal conductivity and high heat resistance environmentally friendly impregnating resin paint according to claim 1, characterized in that: The catalyst is isooctanoate.

4. The high thermal conductivity and high heat resistance environmentally friendly impregnating resin paint according to claim 1, characterized in that: The crosslinking agent is a peroxide.

5. The high thermal conductivity and high heat resistance environmentally friendly impregnating resin paint according to claim 1, characterized in that: The thermal conductive filler is one or more of nanometer or micrometer-sized silicon dioxide, fumed silicon dioxide, aluminum oxide powder, boron nitride, and magnesium oxide.

6. The high thermal conductivity and high heat resistance environmentally friendly impregnating resin paint according to claim 1, characterized in that: The rheology regulator is one or more of bentonite, silicate, anti-settling wax and polyurea.

7. The high thermal conductivity and high heat resistance environmentally friendly impregnating resin varnish according to claim 1, characterized in that: The dispersant is a high molecular weight copolymer alkyl ammonium salt.

8. A method for preparing the high thermal conductivity and high heat resistance environmentally friendly impregnating resin varnish according to any one of claims 1 to 7, characterized in that: The following steps are involved: S1. Add hydroquinone polymerization inhibitor, molecular weight regulator and wetting and leveling agent to the silicon-based modified slurry, disperse and shear the mixture, heat it up, cool it down to below 40°C, and then add catalyst and cross-linking agent and mix them evenly; S2. Add acrylic acid ester active agent, filter and discharge.

9. The method according to claim 8, characterized in that In the step S1, the dispersion speed is 600 to 1000 rpm, and the dispersion time is 30 to 60 minutes.

10. The method according to claim 8, characterized in that In the step S1, the temperature is raised to 70-80° C. and kept warm for 30 minutes to 1 hour.

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