Gradient functional material layer for terminal ceramic silica gel interface and preparation method of gradient functional material layer

Abstract

The invention belongs to the technical field of electrical connection of an air conditioner compressor, and discloses a ceramic silica gel interface gradient function material layer for a terminal, and the material layer is arranged between a ceramic particle of a wiring terminal of the air conditioner compressor and a silica gel injection layer. The gradient functional material layer adopts a gradient composite system of inorganic filler and organic silicon resin, the composition and the structure are continuously and gradually changed in the thickness direction, stable transition of physical and chemical properties between ceramic particles and the silica gel injection layer is achieved, and the problems of interface stripping, stress concentration and the like caused by the difference of thermal expansion coefficients of the ceramic particles and the silica gel injection layer are solved. The interface bonding force and the durability are obviously enhanced; meanwhile, by means of specific raw material selection and a preparation process, the gradient functional material layer has the characteristics of high temperature resistance, high insulation and high strength of an inorganic material and the advantages of good flexibility and good sealing performance of an organic material, the gradient functional material layer, the ceramic particles and the injection glue form a synergistic effect, and the insulation performance, the sealing performance and the shock resistance of the air conditioner compressor wiring terminal are further improved.

Description

Technical Field

[0001] This invention belongs to the field of electrical connection technology for air conditioning compressors, specifically a gradient functional material layer for terminal ceramic silicone interface and its preparation method. Background Technology

[0002] In high-end air conditioning compressors, to improve product reliability, safety, and durability, terminal blocks often employ ceramic particle addition and encapsulation processes. Ceramic particles, as excellent inorganic insulating materials, possess advantages such as high temperature resistance, high insulation strength, non-flammability, and non-aging properties. They enhance electrical insulation and arc resistance, provide mechanical support for metal terminals, and cope with high voltage and high temperature challenges. Encapsulation provides sealing, moisture protection, oil and corrosion prevention, and shock absorption, while also aiding insulation. Working synergistically with ceramic particles, it protects the compressor's core components from external environmental damage.

[0003] However, due to the significant differences in materials, the ceramic and silicone interfaces have markedly different physical and chemical properties. Under the high-temperature and high-frequency vibration environment encountered during the operation of air conditioning compressors, problems such as interface delamination and stress concentration are prone to occur, which seriously affect the structural stability and performance reliability of the entire terminal area, and may reduce the service life and safety level of the air conditioning compressor. Therefore, it is necessary to provide a gradient functional material layer for the ceramic-silicone interface of the terminal and its preparation method. By setting a gradient functional material layer between the ceramic particles and the silicone injection layer, a smooth transition of the physical and chemical properties of the two can be achieved, enhancing the interfacial bonding force and durability, and ensuring the long-term stable operation of the air conditioning compressor. Summary of the Invention

[0004] To address the shortcomings of existing technologies, this invention provides a gradient functional material layer for a ceramic-silicone interface in terminals and a method for preparing the same, thereby solving the problems mentioned in the background section.

[0005] To achieve the above objectives, the present invention provides the following technical solution: a gradient functional material layer for a ceramic-silicone interface of a terminal, wherein the material layer is disposed between ceramic particles and a silicone injection layer in the wiring terminal of an air conditioner compressor, the material layer having a thickness of 50-500 μm, and is chemically bonded to both the ceramic particles and the silicone injection layer; the composition and structure of the material layer gradually change from the ceramic side to the silicone side along the thickness direction; the material layer is a gradient composite system of inorganic fillers and organosilicon resin, wherein the mass proportion of inorganic fillers gradually decreases from the ceramic side to the silicone side, and the mass proportion of organosilicon resin gradually increases.

[0006] Preferably, the inorganic filler includes one or more of alumina, zirconium oxide, and silicon nitride, and the organosilicon resin is one or more modified products of methyl silicone resin, phenyl silicone resin, and vinyl silicone resin.

[0007] Preferably, the mass percentage of inorganic filler from the ceramic side to the silicone side continuously decreases from 60%-80% to 10%-30%, while the mass percentage of organosilicon resin continuously increases from 20%-40% to 70%-90%.

[0008] A method for preparing a gradient functional material layer for a ceramic-silicone interface in terminals, comprising the following specific steps: Step 1: Raw material preparation, selecting inorganic filler, organosilicon resin, curing agent and diluent respectively. The inorganic filler includes one or more of alumina, zirconium oxide and silicon nitride. The organosilicon resin is one or more modified products of methyl silicone resin, phenyl silicone resin and vinyl silicone resin. The curing agent is organotin curing agent or amine curing agent. The diluent is anhydrous ethanol or ethyl acetate. Step 2: Gradient slurry preparation. According to the preset gradient ratio, prepare at least three sets of mixed slurries with different mass ratios of inorganic fillers and silicone resins. From the slurry corresponding to the ceramic side to the slurry corresponding to the silicone side, the mass ratio of inorganic fillers decreases sequentially, and the mass ratio of silicone resin increases sequentially. Add 1%-5% curing agent and 5%-15% diluent to each set of slurries by mass. After stirring evenly, ultrasonically disperse for 20-40 minutes to obtain a uniformly dispersed gradient slurry. Step 3: Surface pretreatment of ceramic particles. The ceramic particles of the air conditioner compressor terminal are degreased, washed with water, and dried in sequence. Then, the surface is activated by plasma treatment equipment for 5-15 minutes to improve the adhesion of the ceramic particle surface. Step 4: Gradient coating. Using a layer-by-layer coating method, the gradient slurry prepared in Step 2 is applied sequentially to the surface of the pretreated ceramic particles, from high inorganic filler content to low inorganic filler content. Each layer is 10-100μm thick. After coating, the material is pre-cured at 60-80℃ for 10-30 minutes until all gradient slurries are coated, forming a gradient functional material preform. Step 5: Final curing and assembly. Place the ceramic particles with the gradient functional material layer in a curing oven at 120-150℃ and cure for 2-4 hours to obtain ceramic particles with the gradient functional material layer. Then install them inside the plastic sheath of the air conditioner compressor terminal block, close to the metal terminal block. Finally, fill the connection between the terminal block and the compressor housing with glue to complete the assembly.

[0009] Preferably, the inorganic filler in step one has a particle size of 50-500 nm, and the silicone resin has a viscosity of 500-2000 mPa at 25°C. s.

[0010] Preferably, the gradient slurry in step two consists of 3-5 groups, and the mass ratio difference of inorganic fillers in two adjacent groups of slurry is 10%-20%.

[0011] Preferably, the degreasing treatment in step three involves soaking in acetone or ethanol for 10-20 minutes, and the drying treatment is performed at a temperature of 80-100°C for 30-60 minutes.

[0012] Preferably, the coating method in step four is one of spraying, brushing or dipping, and the ultrasonic dispersion power is 100-300W.

[0013] Preferably, the heating rate of the curing oven in step five is 5-10℃ / min, and nitrogen gas is introduced for protection during the curing process.

[0014] Preferably, the adhesive used in step five is a silicone or epoxy resin sealant, which adheres tightly to the gradient functional material layer to form a synergistic protective system.

[0015] Compared with the prior art, the beneficial effects of the present invention are as follows: The gradient functional material layer adopts a gradient composite system of inorganic fillers and organosilicon resin. The composition and structure change continuously and gradually along the thickness direction, realizing a smooth transition of physical and chemical properties between ceramic particles and silicone injection layer. This effectively alleviates problems such as interface delamination and stress concentration caused by the difference in thermal expansion coefficients between the two, and significantly enhances the interface bonding and durability. At the same time, with the help of specific raw material selection and preparation process, the gradient functional material layer combines the high temperature resistance, high insulation and high strength of inorganic materials with the advantages of good flexibility and good sealing of organic materials. It forms a synergistic effect with ceramic particles and silicone injection, further improving the insulation, sealing and shock resistance of the air conditioner compressor wiring terminals. Attached Figure Description

[0016] Figure 1 This is a flowchart of the preparation method of the material layer of the present invention. Detailed Implementation

[0017] Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0018] This invention provides a gradient functional material layer for a ceramic-silicone interface of a terminal. The material layer is disposed between the ceramic particles and the silicone injection layer of the air conditioner compressor terminal, with a thickness of 50-500 μm. It is chemically bonded to both the ceramic particles and the silicone injection layer. The composition and structure of the material layer gradually change from the ceramic side to the silicone side along the thickness direction. The material layer is a gradient composite system of inorganic fillers and organosilicon resin. From the ceramic side to the silicone side, the mass proportion of inorganic fillers gradually decreases, while the mass proportion of organosilicon resin gradually increases.

[0019] Achieving a stable connection with ceramic particles and silicone layers through chemical bonding avoids interfacial delamination; a thickness of 50-500μm adapts to terminal installation requirements, balancing protection and space compatibility; the reverse gradient ratio of inorganic filler and organosilicon resin not only continues the high temperature resistance and high insulation properties of the ceramic side, but also matches the flexibility and sealing properties of the silicone side, achieving a smooth performance transition, effectively alleviating stress concentration caused by differences in thermal expansion coefficients, significantly improving interfacial bonding and durability, and ensuring long-term reliable operation of the air conditioning compressor.

[0020] The inorganic filler includes one or more of alumina, zirconium oxide, and silicon nitride, and the organosilicon resin is one or more modified products of methyl silicone resin, phenyl silicone resin, and vinyl silicone resin.

[0021] The selected inorganic fillers, alumina, zirconium oxide, and silicon nitride, all possess excellent high-temperature resistance, high insulation strength, and mechanical strength, matching the performance of ceramic particles and ensuring the insulation and structural stability of the material layer at high temperatures. The modified organosilicon resin products combine good flexibility, sealing properties, and aging resistance, exhibiting excellent compatibility with injection molding. A variety of raw materials are available and can be mixed for use, allowing for flexible adjustment of the formula according to the actual operating conditions of the air conditioning compressor to meet the needs of different scenarios. At the same time, the two types of materials work together to form a gradient system, helping to achieve a smooth transition of performance between the ceramic and silicone sides, enhancing interface compatibility and overall protection.

[0022] Among them, the mass ratio of inorganic fillers from the ceramic side to the silicone side decreased continuously from 60%-80% to 10%-30%, while the mass ratio of organosilicon resin increased continuously from 20%-40% to 70%-90%.

[0023] The ceramic side has a high inorganic filler content of 60%-80%, which can precisely match the high temperature resistance and high insulation performance requirements of ceramic particles, and continue the advantages of mechanical support and arc prevention; the silicone side has a high organic silicone resin content of 70%-90%, which can form good compatibility with injection molding, ensuring sealing and shock absorption effects; through the continuous and gradual change of the proportion, the performance of the two types of materials can be smoothly transitioned, maximizing the mitigation of the difference in thermal expansion coefficients, avoiding interface stress concentration and delamination, and significantly improving the bonding stability between the material layer, ceramic particles, and injection molding.

[0024] A method for preparing a gradient functional material layer for a ceramic-silicone interface in terminals, comprising the following specific steps: Step 1: Raw material preparation. Select inorganic fillers, organosilicon resins, curing agents, and diluents respectively. Inorganic fillers include one or more of alumina, zirconium oxide, and silicon nitride. Organosilicon resins are one or more modified products of methyl silicone resin, phenyl silicone resin, and vinyl silicone resin. Curing agents are organotin curing agents or amine curing agents. Diluents are anhydrous ethanol or ethyl acetate. Step 2: Gradient slurry preparation. According to the preset gradient ratio, prepare at least three sets of mixed slurries with different mass ratios of inorganic fillers and silicone resins. From the slurry corresponding to the ceramic side to the slurry corresponding to the silicone side, the mass ratio of inorganic fillers decreases sequentially, and the mass ratio of silicone resin increases sequentially. Add 1%-5% curing agent and 5%-15% diluent to each set of slurries by mass. After stirring evenly, ultrasonically disperse for 20-40 minutes to obtain a uniformly dispersed gradient slurry. Step 3: Surface pretreatment of ceramic particles. The ceramic particles of the air conditioner compressor terminal are degreased, washed with water, and dried in sequence. Then, the surface is activated by plasma treatment equipment for 5-15 minutes to improve the adhesion of the ceramic particle surface. Step 4: Gradient coating. Using a layer-by-layer coating method, the gradient slurry prepared in Step 2 is applied sequentially to the surface of the pretreated ceramic particles, from high inorganic filler content to low inorganic filler content. Each layer is 10-100μm thick. After coating, the material is pre-cured at 60-80℃ for 10-30 minutes until all gradient slurries are coated, forming a gradient functional material preform. Step 5: Final curing and assembly. Place the ceramic particles with the gradient functional material layer in a curing oven at 120-150℃ and cure for 2-4 hours to obtain ceramic particles with the gradient functional material layer. Then install them inside the plastic sheath of the air conditioner compressor terminal block, close to the metal terminal block. Finally, fill the connection between the terminal block and the compressor housing with glue to complete the assembly.

[0025] The raw material selection is adapted to the requirements of the gradient system, and the combination of curing agent and diluent ensures the stability of the slurry and the subsequent molding effect. The gradient slurry is prepared by using multiple slurries with different proportions and ultrasonic dispersion to ensure uniform composition and meet the gradient requirements. The surface pretreatment of ceramic particles improves the bonding force with the material layer and avoids interface delamination. The layer-by-layer coating and segmented pre-curing process precisely controls the thickness of each layer and the molding quality to achieve a smooth performance transition. The final curing parameters are adapted to the material characteristics to ensure structural stability. The whole process is simple to operate, highly controllable, and easy to industrialize. It can efficiently prepare high-performance gradient functional material layers, greatly improve the reliability of the interface bonding of air conditioner compressor terminals and the overall protection effect, and meet the stringent use requirements of air conditioners.

[0026] In step one, the particle size of the inorganic filler is 50-500 nm, and the viscosity of the silicone resin at 25°C is 500-2000 mPa. s.

[0027] Inorganic filler particle size of 50-500nm ensures uniform dispersion in silicone resin, improving the density and mechanical properties of the material layer; 500-2000mPa at 25℃ The viscosity of the silicone resin is suitable for gradient slurry preparation and coating processes, which not only ensures the stability of the slurry, but also facilitates precise control of the coating thickness, helping to form a gradient material layer with uniform performance and smooth transition, and ensuring the interfacial bonding effect.

[0028] In step two, the gradient slurry consists of 3-5 groups, and the mass ratio of inorganic filler in two adjacent groups of slurry differs by 10%-20%.

[0029] Since the combined mass percentage of inorganic filler and silicone resin in each slurry group is 100%, and their proportions are inversely complementary, the absolute value of the mass percentage difference of silicone resin in two adjacent slurry groups is the same as the absolute value of the mass percentage difference of inorganic filler, which is 10%-20%. From the slurry corresponding to the ceramic side to the slurry corresponding to the silicone side, the mass percentage of silicone resin increases sequentially as the mass percentage of inorganic filler decreases. Through this complementary gradient design, the physical and chemical properties of the material layer are ensured to transition smoothly from the ceramic side to the silicone side, effectively alleviating the problem of interface stress concentration.

[0030] In step three, the degreasing process involves soaking in acetone or ethanol for 10-20 minutes, and the drying process is carried out at a temperature of 80-100℃ for 30-60 minutes.

[0031] Soaking in acetone or ethanol for 10-20 minutes can effectively remove oil stains from the surface of ceramic particles, clearing the way for subsequent activation treatment; drying parameters of 80-100℃ for 30-60 minutes can thoroughly remove surface moisture and residual solvents, avoiding affecting slurry adhesion; this pretreatment process is highly adaptable and can significantly improve the surface cleanliness and activity of ceramic particles.

[0032] In step four, the coating method is one of spraying, brushing, or dipping, and the ultrasonic dispersion power is 100-300W.

[0033] The three coating methods of spraying, brushing, and dipping can be flexibly adapted to different production scenarios and ceramic particle morphologies, improving process applicability; the ultrasonic dispersion power of 100-300W can efficiently break up the agglomeration of inorganic fillers and ensure uniform dispersion of slurry components; the combination of the two ensures precise control of coating thickness and stable molding quality, while also helping to smoothly transition gradient performance and strengthening the bonding reliability between the material layer and ceramic particles.

[0034] In step five, the heating rate of the curing oven is 5-10℃ / min, and nitrogen gas is introduced for protection during the curing process.

[0035] A gentle heating rate of 5-10℃ / min can prevent internal stress and cracks in the material layer due to sudden temperature changes, ensuring structural integrity; nitrogen protection can isolate oxygen and prevent oxidative degradation of the material layer during high-temperature curing, maintaining its original performance; the two work together to ensure that the gradient material layer is fully cured and its performance is stable, further enhancing the reliability of the interface bonding with ceramic particles and injection adhesive.

[0036] In step five, the adhesive used is silicone or epoxy resin sealant, which adheres tightly to the graded functional material layer to form a synergistic protection system.

[0037] Silicone or epoxy resin sealants possess excellent sealing, moisture-proof, and shock-absorbing properties. When tightly bonded with a gradient functional material layer, they form a synergistic protection system. The gradient layer alleviates interfacial stress and strengthens the bond, while the sealant builds a solid external protective barrier. The two complement each other and enhance each other's effectiveness, significantly improving the insulation, sealing, and durability of the air conditioning compressor terminals, ensuring long-term stable operation of the equipment.

[0038] It should be noted that, in this document, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such process, method, article, or apparatus.

[0039] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A gradient functional material layer for a ceramic-silicone interface in terminals, characterized in that: The material layer is disposed between the ceramic particles and the silicone injection layer of the air conditioner compressor terminal, with a thickness of 50-500μm, and is chemically bonded to both the ceramic particles and the silicone injection layer. The composition and structure of the material layer gradually change from the ceramic side to the silicone side along the thickness direction. The material layer is a gradient composite system of inorganic filler and organosilicon resin. From the ceramic side to the silicone side, the mass proportion of inorganic filler gradually decreases, and the mass proportion of organosilicon resin gradually increases.

2. The gradient functional material layer for a ceramic-silicone interface in a terminal according to claim 1, characterized in that: The inorganic filler includes one or more of alumina, zirconium oxide, and silicon nitride, and the organosilicon resin is one or more modified products of methyl silicone resin, phenyl silicone resin, and vinyl silicone resin.

3. The gradient functional material layer for a ceramic-silicone interface in a terminal according to claim 1, characterized in that: The mass percentage of inorganic fillers from the ceramic side to the silicone side continuously decreases from 60%-80% to 10%-30%, while the mass percentage of organosilicon resin continuously increases from 20%-40% to 70%-90%.

4. A method for preparing a gradient functional material layer for a ceramic-silicone interface in terminals, characterized in that, The specific steps are as follows: Step 1: Raw material preparation, selecting inorganic filler, organosilicon resin, curing agent and diluent respectively. The inorganic filler includes one or more of alumina, zirconium oxide and silicon nitride. The organosilicon resin is one or more modified products of methyl silicone resin, phenyl silicone resin and vinyl silicone resin. The curing agent is organotin curing agent or amine curing agent. The diluent is anhydrous ethanol or ethyl acetate. Step 2: Gradient slurry preparation. According to the preset gradient ratio, prepare at least three sets of mixed slurries with different mass ratios of inorganic fillers and silicone resins. From the slurry corresponding to the ceramic side to the slurry corresponding to the silicone side, the mass ratio of inorganic fillers decreases sequentially, and the mass ratio of silicone resin increases sequentially. Add 1%-5% curing agent and 5%-15% diluent to each set of slurries by mass. After stirring evenly, ultrasonically disperse for 20-40 minutes to obtain a uniformly dispersed gradient slurry. Step 3: Surface pretreatment of ceramic particles. The ceramic particles of the air conditioner compressor terminal are degreased, washed with water, and dried in sequence. Then, the surface is activated by plasma treatment equipment for 5-15 minutes to improve the adhesion of the ceramic particle surface. Step 4: Gradient coating. Using a layer-by-layer coating method, the gradient slurry prepared in Step 2 is applied sequentially to the surface of the pretreated ceramic particles, from high inorganic filler content to low inorganic filler content. Each layer is 10-100μm thick. After coating, the material is pre-cured at 60-80℃ for 10-30 minutes until all gradient slurries are coated, forming a gradient functional material preform. Step 5: Final curing and assembly. Place the ceramic particles with the gradient functional material layer in a curing oven at 120-150℃ and cure for 2-4 hours to obtain ceramic particles with the gradient functional material layer. Then install them inside the plastic sheath of the air conditioner compressor terminal block, close to the metal terminal block. Finally, fill the connection between the terminal block and the compressor housing with glue to complete the assembly.

5. The method for preparing a gradient functional material layer for a ceramic-silicone interface in a terminal according to claim 4, characterized in that: The inorganic filler in step one has a particle size of 50-500 nm, and the silicone resin has a viscosity of 500-2000 mPa at 25°C. s.

6. The method for preparing a gradient functional material layer for a ceramic-silicone interface in a terminal according to claim 4, characterized in that: The gradient slurry in step two consists of 3-5 groups, and the mass ratio difference of inorganic fillers in two adjacent groups of slurry is 10%-20%.

7. The method for preparing a gradient functional material layer for a ceramic-silicone interface in a terminal according to claim 4, characterized in that: The degreasing treatment in step three involves soaking in acetone or ethanol for 10-20 minutes, and the drying treatment is carried out at a temperature of 80-100℃ for 30-60 minutes.

8. The method for preparing a gradient functional material layer for a ceramic-silicone interface in a terminal according to claim 4, characterized in that: The coating method described in step four is one of spraying, brushing, or dipping, and the ultrasonic dispersion power is 100-300W.

9. A method for preparing a gradient functional material layer for a ceramic-silicone interface in a terminal according to claim 4, characterized in that: The heating rate of the curing oven in step five is 5-10℃ / min, and nitrogen gas is introduced for protection during the curing process.

10. The method for preparing a gradient functional material layer for a ceramic-silicone interface in a terminal according to claim 4, characterized in that: The adhesive used in step five is a silicone or epoxy resin sealant, which adheres tightly to the graded functional material layer to form a synergistic protective system.

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