Coating classification: insulating coating

Core tip: brief introduction of insulating coating Insulating coating, in our daily life, has made a great contribution to the safety of human life, is a very important coating Insulating coating refers to the coating with excellent electrical insulation and good electrical, thermal, mechanical and chemical properties General insulating coatings are mostly varnish, of course, colored paint, but not much Insulating coating is generally used for internal parts of electronic products to play the role of insulation For example, it is often used for rotor core coating as slot, micro motor stator insulation, etc., and it is especially suitable for automobiles and motorcycles Paint agent, top 10 Chinese wall paint brands Recommended introduction: interior wall paint and exterior wall paint can achieve beautiful, clean and pleasant effects, but the effects in different environments are different, so the color of the paint will be different There are ten brands of Chinese paint, ten brands of global paint, ten brands of Chinese wall paint, and ten brands of Chinese paint, Famous trademark of Chinese paint and coating In private rooms, most of us choose according to our own personality, personal hobbies and living habits The younger generation will choose the interior wall paint with rich colors and bright colors, while the older ones will have some working experience Coating home news: insulation coating brief introduction insulation coating, in our daily life, has made a great contribution to the safety of human life, is a very important coating Insulating coating refers to the coating with excellent electrical insulation and good electrical, thermal, mechanical and chemical properties General insulating coatings are mostly varnish, of course, colored paint, but not much Insulating coating is generally used for internal parts of electronic products to play the role of insulation For example, it is often used for rotor core coating as slot, micromotor stator insulation, etc., and is especially suitable for automobile, motorcycle and hair dryer motor rotor coating as slot insulation Insulating coating is characterized by insulation, high temperature resistance, high hardness, excellent oxidation resistance, thermal shock resistance, medium coefficient of thermal expansion and other excellent functions, so it has been widely used in recent years, some even widely used in aircraft parts It has the following characteristics: 1 High dielectric strength (breakdown strength), more than 10kV / m 2 High volume resistivity, more than 10 Ω m at room temperature 3 No flash point or flash point, high hardness, hardness greater than 7h 4 Good chemical stability, aging resistance, corrosion resistance and oxidation resistance 5 The coating shall be free of any volatilization, and no odor shall be generated under normal temperature and high temperature 6 Heat resistant 1700 ℃, Zhisheng Weihua high temperature resistant solution shall be used, and the insulating coating can work under 1700 ℃ for a long time Insulation coating classification I: according to its application, it can be divided into: (1) impregnated insulation paint (for impregnated insulation treatment of winding) Solventless impregnated insulating paint, namely solventless impregnated resin, is composed of synthetic resin, curing agent and active dilution It is characterized by fast curing, fast viscosity change with temperature, good fluidity and permeability, good insulation integrity, and less volatiles during curing Therefore, the application of solventless impregnated paint can improve the thermal conductivity and moisture resistance of insulation structure, reduce material consumption, and improve Labor conditions, shorten the production cycle Solventless insulating paint has many kinds and properties, such as: epoxy insulating paint, polyester insulating paint, quick drying insulating paint, which is also widely used (2) enameled wire paint (used as insulating layer of conductor) enameled wire paint is a kind of paint that can produce good insulating layer between conductor in winding It is mainly used for the outer layer of bare copper wire, alloy wire and glass wire with various wire diameters to improve and stabilize the performance of enameled wire It is mainly used for the outer layer of bare copper wire, alloy wire and glass wire with various wire diameters to improve and stabilize the performance of enameled wire (3) silicon steel sheet paint (used as insulating layer of silicon steel sheet) core silicon steel sheet insulation can effectively reduce core eddy current loss, reduce temperature rise, improve motor efficiency, and enhance the corrosion resistance, oil resistance and rust resistance of motor The surface insulation treatment of stator core silicon steel sheet requires that the insulating layer shall have good dielectric property, oil resistance, moisture resistance, strong adhesion and sufficient mechanical strength and hardness (4) covering insulating paint (used as the protective layer of the winding which has been impregnated with insulating treatment to prevent mechanical damage or convenient assembly) covering paint can be divided into varnish and enamel Varnish is composed of paint base, desiccant and solvent Enamel is mainly used to coat insulating parts, motor and electrical appliance surfaces with filler and covering paint on the basis of varnish Silicon steel sheet paint is mainly used for coating insulation on the surface of silicon steel sheet (5) adhesive insulating paint (used for bonding mica, laminate and other insulating materials) paint that binds insulating materials with insulating materials and insulating materials with other materials Its main function is adhesion The paint used for manufacturing mica products, composite products and laminated products is adhesive paint (6) special insulating paint is used for the insulating layer of resistance, capacitor and potentiometer 2： According to the classification of drying methods (1) drying paint: the paint that can be dried to a higher temperature is drying paint Most of the insulating paints are drying paints, such as oil modified polyglycerol phthalic anhydride resin paint, oil modified phenolic resin paint, poly and polyester enameled wire paint, etc (2) Air dry paint: the paint that can be dried to form paint film at room temperature is air dry paint 3： According to the main chemical composition of paint base: (1) resin varnish: paint base is composed of synthetic resin, natural resin, etc., without vegetable oil Polyester enameled wire paint, phenolic varnish, silicone paint are resin paint (2) Enamel: the paint containing pigment in film-forming substance is enamel In addition to giving paint color, pigment can also improve the hardness, heat resistance and thermal conductivity of paint film (3) oily paint: the paint base is composed of vegetable oil, synthetic resin and natural resin Often contains desiccant Modified alkyd resin belongs to this category 4： According to the basic composition of paint: (1) solvent paint: it is a kind of solution, dispersion or turbid liquid of polymer or polymer mixture in volatile inactive solvent (2) solventless paint: it is a paint without volatile essential solvent It has the characteristics of reducing pollution, improving quality and work efficiency 5： Insulation coating can be divided into seven grades of 90, 105, 120, 130, 155, 180 and above according to the heat resistance index The common functional parameters of insulating coating: 1 Current: it is composed of three parts The charging current in a flash (the displacement polarization of how many capacitors of the medium occurs, and gradually attenuates with the increase of time, which is indicated by IC), the drawing current (the volume charge generated by slow polarization and conductive ions, etc.) also gradually attenuates with the increase of time, which is indicated by IA ）, revealing the current (revealing that the size of the current is closely related to the ion content of the insulating coating itself, which is indicated by IB) 2 Insulation resistance: the value obtained by dividing the DC voltage between the two electrodes fighting with the insulator or sample by the total current passing through the two electrodes 3 Volume resistance: the quotient of the DC voltage applied between the two electrodes arranged on the relative two profiles of the sample divided by the steady-state current formed between the two electrodes, that is, the resistance between the insulating coating and the two profiles 4 Volume resistivity: the quotient of the DC electric field strength in the sample divided by the steady-state current density can be seen as the volume resistance in the cubic volume of a unit The volume resistivity of insulating coating is generally 109-1021w.cm 5 Profile resistance: the quotient of the DC voltage between two electrodes added on the same profile of insulator or sample divided by the current between the two electrodes after a certain electrification time 6 General resistivity: the value obtained by dividing the DC electric field strength in the general situation of insulating coating by the current line density 7 Factors affecting resistivity: temperature, humidity, impurities and electric field strength (1) Temperature: with the decrease of temperature, the resistivity decreases exponentially This is because when the temperature decreases, the molecular thermal activity increases, the uniform kinetic energy of the molecular increases, the probability of the molecular kinetic energy reaching the activation energy increases, and the ions are easy to migrate (2) humidity: the insulation resistance decreases with the increase of humidity The effect on porous coating (such as paper) is particularly obvious, and the resistance of dielectric profile has a slow effect on its profile water content Electrical equipment, especially outdoor equipment, can check the change of insulation resistance of equipment on schedule, so as to prevent the occurrence of disorder (3) impurities: impurities increase and resistivity decreases Generally, impurities purified by impurities and adsorbed by water directly increase the conductive ion impurities outside the dielectric, which are easy to mix with the polarity to be guessed After mixing with people, it can promote the dissociation of polar molecules The insulating coating produced by Zhisheng Weihua can prevent impurities from mixing In order to effectively improve the functions of ceramic coating related to it and improve the preparation quality of ceramic coating with complex sample profile 8 Dielectric: all materials that can create polarization under the influence of electric field Insulating coating is one of the dielectrics 8 In the external electric field, the electric charge (beam localized charge) occurs in the dielectric profile, which is called the polarization of the dielectric 9 The basic situation of polarization: displacement polarization, corruption polarization, turning polarization, space charge polarization, conscious polarization 10 Dielectric constant: ε - dielectric constant, indicating the polarization function of dielectric ε 0 - dielectric constant in vacuum, also known as absolute dielectric constant The value is 8.854187817 × 10-12 method / m ε r-relative permittivity, infinite class, generally referred to as permittivity The dielectric constant of gas is slightly greater than 1, that of liquid is generally 1.8-2.8, that of non-polar solid is generally 2.0-2.5, and that of polar solid is generally > 3 11 Dielectric consumption: the energy consumption caused by the dielectric unit time, that is, the energy that causes the generating medium to have a fever, is called the dielectric consumption 12 Aging of insulating coating: in the operation process of insulating coating in electrical equipment, a series of irreversible changes will occur due to the lasting influence of all kinds of agents, resulting in the deterioration of its physical, chemical, electrical and machine functions Such irreversible changes are generally called aging The important performance of polymer aging: (1) apparent change: paint discoloration, viscosity change, deformation, cracking, embrittlement; (2) physical and chemical function change: relative molecular weight, relative molecular quality dispersion, melting point, ablation degree, heat resistance, cold resistance, permeability, light transmittance, etc.; (3) machine function: elasticity, hardness, strength, elongation, adhesion, wear resistance, etc; (4) Motor energy: insulation resistance, dielectric constant, dielectric consumption tangent, breakdown strength, etc Chi Sheng Wei Hua ZS-1091 insulation coating is made of pure organic nano material, and its anti-aging function is excellent Internal causes of insulation aging: chemical layout: composition and layout of chain links, sorting methods of chain links in macromolecules, properties of end groups, length and number of branch chains Relating to the process and premise of decomposition reaction; physical arrangement: aggregation states of high molecules, such as amorphous, crystalline, oriented and