Modified epoxy organosilicon high-thermal-conduction insulating impregnating paint and preparation method thereof

Abstract

The invention discloses an insulating impregnating paint and a preparation method thereof. The insulating impregnating paint comprises a matrix resin, a diluent and a curing agent, wherein the matrixresin is prepared by carrying out a condensation reaction on a modified epoxy resin and organic silanol having silanol, the raw materials of the modified epoxy resin comprise an epoxy resin, a vinyl monomer containing an ester group and a hydrophobic hexagonal boron nitride nano-sheet containing vinyl, the modified epoxy resin is produced by polymerizing the epoxy resin and the remaining raw materials, and the boron nitride nano-sheet is prepared by using the following specific method: carrying out surface hydroxyl modification, carrying out freeze-thaw expansion treatment, and catalyzing boron nitride stripping and esterification modification by combining with a specific compound one-pot method. The preparation method of the insulating impregnating paint comprises: mixing and stirring thematrix resin, the diluent and the curing agent to obtain the product. According to the present invention, the insulating impregnating paint has advantages of stable inter-batch product quality and the like on the basis of high thermal conductivity coefficient, low dielectric loss, high-low temperature impact resistance, good bonding strength, good permeability, high electric field strength and high mechanical strength.

Description

technical field [0001] The invention belongs to the technical fields of polymer composite materials and electrical engineering, and in particular relates to a modified epoxy organosilicon high thermal conductivity insulating impregnating varnish and a preparation method thereof. Background technique [0002] Insulation impregnating varnish is mainly used in the insulation impregnation treatment of motors, transformers and loose reactance winding coils to fill the gaps between the coils and the gaps between the coils and surrounding objects (such as iron cores, interlayer insulation pads, heat shrinkable sleeves, etc.), Bonding coil wires and wires, wires and other objects, mainly plays the role of electrical insulation and bonding molding, improves the mechanical properties, electrical strength and protection performance of the coil, etc. The insulating impregnating varnish can also be used for impregnation, Coating or encapsulation materials. [0003] With the development ...

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Problems solved by technology

[0004] For example, the Chinese invention patent CN101381583 B discloses a high thermal conductivity organosilicon dipping varnish, which is made of mixed aluminum nitride powder by mixing three kinds of aluminum nitride powders with different average particle sizes and high thermal conductivity and high insulation properties. Body filler, and the mixed mixed aluminum nitride powder filler is added to the silicone prepolymer, then catalyst and curing agent are added, and it is uniformly prepared by conventional ball milling. The particle size of the thermal conductive filler is 5-20 μm, and the dosage More than 20%; Another example is that the Chinese invention patent CN101864145 A discloses a high thermal conductivity insulating impregnated resin for air-core reactors and its preparation method. The impregnated resin is composed of epoxy resin, toughening agent, curing agent, curing accelerator, silicon micropowder, Inorganic powders such as aluminum oxide powder and sericite powder are stirred and heated to 60-75°C under reduced pressure and defoaming. Up to 0.386~0.502W / (m·k), 0.35~0.90W / (m·K), but both affect the mechanical properties, and at the same time have a greater impact on the viscosity, reducing the permeability of the dipping paint, poor fluidity, no It is conducive to the formation of an overall insulation structure without air gaps and is not conducive to impregnation treatment; another example is the Chinese invention patent CN102295878A which discloses a filling type thermally conductive and insulating impregnated varnish, which is based on surface functionalized inorganic powder with high thermal conductivity and high insulation performance. Filler (specifically silane modification) is obtained by adding it to the modified epoxy resin, and then adding a dispersant, a peroxide initiator and a reactive diluent, and mixing it. Although the thermal conductivity of the thermally conductive dipping paint is greatly improved, it can be Up to 0.31-0.5W / (m K), but in actual application, there is a high probability of uneven dispersion, and sedimentation, nanoparticle agglomeration, and unstable product quality between batches affect the thermal conductivity and electromechanical efficiency of the product. performance

[0005] At the same time, high thermal conductivity insulating impregnation varnish or resin needs to be applied to the insulation system of large and medium-sized high-voltage generators or electronic components, so it is not only necessary to improve the thermal conductivity, but also requires low dielectric loss, high electric field strength, excellent toughness, high and low temperature impact resistance, Good bonding strength, etc. In addition, good permeability is required. It is difficult for the current impregnating paint to meet the above requirements at the same time

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