A waterproof coating for consumer electronic mainboard and preparation method thereof

Abstract

The present invention proposes a waterproof coating for a consumer electronic motherboard and a preparation method thereof, and belongs to the technical field of coatings. MeHSiCl2, Me3SiCl, MeViSiCl2, and MeSiCl3 are mixed and reacted with ammonia, and then the surface is modified by a silane coupling agent, hydrolyzed, solidified and sintered, the surface is modified by a silane coupling agent, stirred and reacted with polyether diol, chlorinated paraffin and isocyanate, a drying agent and tetramethylbenzene are added, stirred, and discharged to obtain a pre-hybridized resin, and the pre-hybridized resin is mixed with polyether diol, paraffin, dibutyl phthalate, aromatic oil, dispersant, defoamer, calcium stearate, montmorillonite powder, 3,3'-dichloro-4,4'-diaminodiphenylmethane, and tetramethylbenzene, stirred and mixed, evenly applied, ventilated and maintained, and the waterproof coating for the consumer electronic motherboard is obtained, which has excellent insulation, moisture-proof, waterproof, leakage-proof, shock-proof, dust-proof, corrosion-resistant, anti-aging, corona-resistant and other properties.

Description

Technical Field

[0001] The present invention relates to the technical field of coatings, and in particular to a waterproof coating for a consumer electronic mainboard and a preparation method thereof. Background Art

[0002] During the use and storage of electronic products, they are usually subjected to chemical, vibration, high dust, salt spray, humidity and high temperature environments. Circuit boards and their electronic components may suffer from corrosion, softening, deformation and mildew, which may lead to circuit board failure. In order to make the printed circuit boards of electronic products have good three-proof protection capabilities, three-proof protective coatings are usually sprayed after the printed circuit boards are debugged. At present, the waterproof and moisture-proof treatment of electronic products and equipment is mostly achieved through structural design, and rubber gaskets are used at the seams of the shell for seam protection to achieve a certain waterproof level. This treatment method cannot fundamentally solve the problem.

[0003] US Patent US20150146396 describes an electronic device with an internal waterproof coating. The waterproof electronic device includes at least one electronic component at least partially covered by the waterproof coating. The waterproof coating may be located inside the electronic device. The waterproof coating may only cover part of the boundary of the internal space within the electronic device. The waterproof coating may include one or more discernible boundaries or seams, which may be located at or adjacent to the position where two or more components of the electronic device are joined to each other. It is not specified what kind of waterproof coating is used, whether it is cured at room temperature, and it is impossible to judge its effectiveness in large-scale industrial applications.

[0004] Chinese patent CN203407069U describes that the utility model discloses a circuit board with a hydrophobic waterproof and moisture-proof coating, including: a substrate, a circuit or electronic component is arranged on the surface; and a hydrophobic coating is laid on the surface of the substrate, the hydrophobic coating surface has a microstructure with a plurality of fine protrusions, and the surface of the microstructure is covered with a non-hydrophilic substrate; the size of the microstructure is 5 to 15 microns. The utility model can not only effectively waterproof, but also use its waterproof and moisture-proof properties to shrink the water on the surface into beads, so as to facilitate the dryness and cleanliness of the surface. And due to the characteristics of the material, it will not conduct electricity by itself after coating, but each metal contact will not cause poor contact or disconnection due to the thickness of the coating film. The hydrophobic angle in the coating is between 110-120°C, and the water droplets cannot slide freely. Although the waterproof performance is enhanced, no water resistance immersion test is carried out, and it is impossible to judge whether it still has reliable waterproof performance after long-term use. Summary of the invention

[0005] The purpose of the present invention is to provide a waterproof coating for consumer electronic motherboards and a preparation method thereof, which is suitable for environments with temperatures ranging from -60 to 200°C and has excellent insulation, moisture-proof, waterproof, anti-leakage, shock-proof, dust-proof, anti-corrosion, anti-aging, and corona-resistant properties. In addition, the coating protective film is also beneficial to the high mechanical strength of circuits and components, abrasion resistance, and solvent resistance, and can release the pressure caused by periodic temperature changes. It can fully protect the circuit board from being used in harsh environments such as various chemical corrosion, salt spray, humidity, high pollution and dust, vibration, high and low temperature, etc. without affecting its work and signals.

[0006] The technical solution of the present invention is achieved in this way:

[0007] The present invention provides a method for preparing a waterproof coating of a consumer electronic mainboard, wherein MeHSiCl 2 、Me 3 SiCl、MeViSiCl 2 、MeSiCl 3 The mixture is reacted with ammonia, and then the surface is modified by a silane coupling agent, hydrolyzed, cured and sintered. The surface is further modified by a silane coupling agent, stirred and reacted with polyether diol, chlorinated paraffin and isocyanate, a drying agent and tetramethylbenzene are added, stirred, and discharged to obtain a pre-hybridized resin, which is mixed with polyether diol, paraffin, dibutyl phthalate, aromatic oil, dispersant, defoamer, calcium stearate, montmorillonite powder, 3,3'-dichloro-4,4'-diaminodiphenylmethane and tetramethylbenzene, stirred and mixed evenly, and evenly applied to the surface of a consumer electronic motherboard, ventilated and maintained to obtain a waterproof coating for the consumer electronic motherboard.

[0008] As a further improvement of the present invention, the following steps are included:

[0009] S1. Preparation of vinyl oligosilazane: Under inert gas protection, MeHSiCl 2 、Me 3 SiCl、MeViSiCl 2 、MeSiCl 3 Mix evenly, introduce ammonia, heat and stir to react, filter, wash, and dry the filtrate to obtain vinyl oligosilazane;

[0010] S2. Preparation of modified vinyl oligosilazane: adding vinyl oligosilazane to ethanol, adding a silane coupling agent and an initiator, heating and stirring the reaction, filtering, washing, and drying to obtain modified vinyl oligosilazane;

[0011] S3. Hydrolysis: adding the modified vinyl oligosilazane to water, heating for hydrolysis, stirring for reaction, filtering, washing, ball milling, and drying to obtain silicon oxide-coated silazane;

[0012] S4. Curing and sintering: calcining the silicon oxide-coated silazane under inert gas protection to obtain a hard ceramic material;

[0013] S5. Preparation of modified particles: adding a hard ceramic material to ethanol, adding a silane coupling agent having an amino group, heating and stirring to react, centrifuging, washing, and drying to obtain a modified hard ceramic material;

[0014] S6. Preparation of pre-hybridized resin: The modified hard ceramic material, polyether diol, and chlorinated paraffin are heated and stirred under inert gas protection, isocyanate is added, the reaction is stirred, a drying agent and tetramethylbenzene are added, stirred, and the material is discharged to obtain a pre-hybridized resin;

[0015] S7. Preparation of waterproof coating for consumer electronic motherboard: heat and stir polyether diol, paraffin, dibutyl phthalate, aromatic oil, dispersant and defoaming agent, add calcium stearate, montmorillonite powder and 3,3'-dichloro-4,4'-diaminodiphenylmethane, heat and stir, add tetramethylbenzene, stir and mix evenly, add pre-hybridized resin, stir and mix evenly, apply evenly to the surface of consumer electronic motherboard, ventilate and maintain, to obtain waterproof coating for consumer electronic motherboard.

[0016] As a further improvement of the present invention, the MeHSiCl in step S1 2 、Me 3 SiCl、MeViSiCl 2 、MeSiCl 3 The molar ratio is 5-7:2-4:1-3:1, the ventilation rate of ammonia is 30-50 mL / min, the temperature of the heating and stirring reaction is 30-40°C, and the time is 3-5 h.

[0017] As a further improvement of the present invention, the mass ratio of the vinyl oligosilazane, the silane coupling agent and the initiator in step S2 is 10:2-3:0.1-0.2, the temperature of the heating and stirring reaction is 40-50°C, the time is 1-2h, the silane coupling agent is selected from at least one of KH570, A151, and A171, and the initiator is selected from at least one of ammonium persulfate, potassium persulfate, and sodium persulfate.

[0018] As a further improvement of the present invention, the temperature of the heating hydrolysis in step S3 is 80-90° C. and the time is 1-2 h.

[0019] As a further improvement of the present invention, the calcination temperature in step S4 is 800-1200° C. and the calcination time is 1-2 h.

[0020] As a further improvement of the present invention, the mass ratio of the hard ceramic material and the silane coupling agent with amino group in step S5 is 10:1-2, the temperature of the heating and stirring reaction is 40-50°C, the time is 1-2h, and the silane coupling agent with amino group is selected from at least one of KH550, KH602, and KH792.

[0021] As a further improvement of the present invention, the mass ratio of the modified hard ceramic material, polyether diol, chlorinated paraffin, isocyanate, drying agent and tetramethylbenzene in step S6 is 10:4-7:15-20:25-30:0.1-0.2:3-5, the polyether diol is polyether diol 2020 or polyether diol 3135, the drying agent is drying agent T12 or drying agent T22, and the isocyanate is at least one of toluene diisocyanate, isophorone diisocyanate, diphenylmethane diisocyanate, dicyclohexylmethane diisocyanate and hexamethylene diisocyanate.

[0022] As a further improvement of the present invention, the polyether diol in step S7 is polyether diol 2020 or polyether diol 3135, and the mass ratio of the polyether diol, paraffin, dibutyl phthalate, aromatic oil, dispersant, defoamer, calcium stearate, montmorillonite powder, 3,3'-dichloro-4,4'-diaminodiphenylmethane, tetramethylbenzene, and pre-hybridized resin is 5-7:10-15:1-2:25-30:0.5-1:0.2-0.3:0.1-0.2:1-2:0.05-0.1:2-3:10, and the ventilation curing time is 48-96h.

[0023] The present invention further protects a waterproof coating of a consumer electronic mainboard prepared by the above preparation method.

[0024] The present invention has the following beneficial effects:

[0025] The present invention adopts chlorosilane ammonolysis / amine solution synthesis method to prepare low-polysilazane with vinyl, on the one hand, improves ceramic yield, on the one hand, is convenient for subsequent modification, has excellent weather resistance, ultraviolet light resistance, corrosion resistance, stain resistance, anti-graffiti, scratch resistance and heat resistance, but directly added to the coating has a certain negative impact on the mechanical properties of the coating, and has certain water resistance, but water resistance can not meet the needs of electronic products. The present invention uses the obtained low-polysilazane of vinyl as a precursor material, and the surface is subjected to the double bond of vinyl low-polysilazane and the double bond of the silane coupling agent with double bond copolymerization reaction under the action of an initiator, so that the silane coupling agent is uniformly coated on the surface of vinyl low-polysilazane for modification, and in the process of heating and hydrolysis, the siloxane part is decomposed into silicon oxide, which is coated on the surface of vinyl low-polysilazane, further improving the water resistance and fire resistance of the material, and also contributing to improving the mechanical properties of the coating.

[0026] The method comprises the following steps: calcining the prepared silicon oxide-coated silazane to obtain a hard ceramic material; after the surface is modified by a silane coupling agent containing amino groups, the surface has amino groups and can react with isocyanate to form a prepolymer, thereby obtaining a pre-hybridized resin, which greatly improves the dispersibility of the hard ceramic material in the coating, improves the mechanical properties and waterproof, fireproof and weather-resistant properties of the coating, and further prepares a coating with polyurethane as the matrix, which has an excellent waterproof effect, certain flame retardancy and good comprehensive performance.

[0027] The waterproof coating of the consumer electronic mainboard prepared by the present invention is a polymer waterproof coating for coating the surface of electronic components, which is suitable for environments with a temperature of -60 to 200°C and has excellent insulation, moisture-proof, waterproof, leakage-proof, shock-proof, dust-proof, corrosion-proof, anti-aging, and corona-resistant properties. In addition, the coating protective film is also beneficial to the high mechanical strength of the circuit and components, abrasion resistance, and solvent resistance, and can release the pressure caused by periodic temperature changes. It can fully protect the circuit board from being used in harsh environments such as various chemical corrosion, salt spray, humidity, high pollution and dust, vibration, high and low temperature, etc. without affecting its work and signal. DETAILED DESCRIPTION

[0028] The technical solutions in the embodiments of the present invention are described clearly and completely below. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0029] Example 1

[0030] This embodiment provides a method for preparing a waterproof coating of a consumer electronic motherboard, comprising the following steps:

[0031] S1. Preparation of vinyl oligosilazane: Under nitrogen protection, 0.5 mol MeHSiCl 2 、0.2molMe 3 SiCl, 0.1 mol MeViSiCl 2 、0.1mol MeSiCl 3 Mix well, introduce ammonia at a flow rate of 30 mL / min, heat to 30°C, stir to react for 3 h, filter, wash, and dry the filtrate to obtain vinyl oligosilazane;

[0032] S2. Preparation of modified vinyl oligosilazane: 10 g of vinyl oligosilazane was added to 300 mL of ethanol, 2 g of silane coupling agent KH570 and 0.1 g of ammonium persulfate were added, heated to 40 ° C, stirred for 1 h, filtered, washed, and dried to obtain modified vinyl oligosilazane;

[0033] S3. Hydrolysis: 10 g of modified vinyl oligosilazane was added to 200 mL of water, heated to 80 ° C, stirred for hydrolysis reaction for 1 h, filtered, washed, ball milled for 1 h, and dried to obtain silicon oxide-coated silazane;

[0034] S4. Curing and sintering: 10 g of silicon oxide-coated silazane was added to 800 ° C under nitrogen protection and calcined for 1 h to obtain a hard ceramic material;

[0035] S5. Preparation of modified particles: 10 g of hard ceramic material was added to 200 mL of ethanol, 1 g of silane coupling agent KH550 was added, heated to 40 ° C, stirred for 1 h, centrifuged, washed, and dried to obtain a modified hard ceramic material;

[0036] S6. Preparation of pre-hybridized resin: 10 g of modified hard ceramic material, 4 g of polyether diol 3135, and 15 g of 52# chlorinated paraffin were heated to 110 ° C under nitrogen protection, stirred and mixed for 1 h, 25 g of isocyanate HDI was added, stirred and reacted for 2 h, 0.1 g of drying agent T12, 4 g of tetramethylbenzene were added, stirred for 30 min, and the material was discharged to obtain a pre-hybridized resin;

[0037] S7. Preparation of waterproof coating for consumer electronic motherboard: Heat 5g polyether diol 3135, 10g 52# paraffin, 1g dibutyl phthalate, 25g 13# aromatic oil, 0.5g dispersant F127, and 0.2g defoamer DF530 to 95°C, stir and mix for 30 minutes, add 0.1g calcium stearate, 1g montmorillonite powder, and 0.05g 3,3'-dichloro-4,4'-diaminodiphenylmethane and heat to 110°C, stir and mix for 4 hours, add 2g tetramethylbenzene, stir and mix for 30 minutes, add 10g pre-hybridized resin, stir and mix for 1 hour, evenly apply to the surface of consumer electronic motherboard, ventilate and maintain for 96 hours to obtain the waterproof coating for consumer electronic motherboard.

[0038] Example 2

[0039] This embodiment provides a method for preparing a waterproof coating of a consumer electronic motherboard, comprising the following steps:

[0040] S1. Preparation of vinyl oligosilazane: Under nitrogen protection, 0.7 mol MeHSiCl 2 、0.4molMe 3SiCl, 0.3 mol MeViSiCl 2 、0.1mol MeSiCl 3 Mix well, introduce ammonia at a flow rate of 50 mL / min, heat to 40°C, stir and react for 5 h, filter, wash, and dry the filtrate to obtain vinyl oligosilazane;

[0041] S2. Preparation of modified vinyl oligosilazane: 10 g of vinyl oligosilazane was added to 300 mL of ethanol, 3 g of silane coupling agent A151 and 0.2 g of potassium persulfate were added, heated to 50 ° C, stirred for 2 h, filtered, washed, and dried to obtain modified vinyl oligosilazane;

[0042] S3. Hydrolysis: 10 g of modified vinyl oligosilazane was added to 200 mL of water, heated to 90 ° C, stirred for hydrolysis reaction for 2 h, filtered, washed, ball milled for 1 h, and dried to obtain silicon oxide-coated silazane;

[0043] S4. Curing and sintering: 10 g of silicon oxide-coated silazane was added to 1200 ° C under nitrogen protection and calcined for 2 h to obtain a hard ceramic material;

[0044] S5. Preparation of modified particles: 10 g of hard ceramic material was added to 200 mL of ethanol, 2 g of silane coupling agent KH602 was added, heated to 50 ° C, stirred for 2 h, centrifuged, washed, and dried to obtain a modified hard ceramic material;

[0045] S6. Preparation of pre-hybridized resin: 10 g of modified hard ceramic material, 7 g of polyether diol 3135, and 20 g of 52# chlorinated paraffin were heated to 110 ° C under nitrogen protection, stirred and mixed for 1 h, 30 g of isocyanate HDI was added, stirred and reacted for 4 h, 0.2 g of drying agent T22, 5 g of tetramethylbenzene was added, stirred for 30 min, and the material was discharged to obtain a pre-hybridized resin;

[0046] S7. Preparation of waterproof coating for consumer electronic motherboard: Heat 7g polyether diol 3135, 15g 52# paraffin, 2g dibutyl phthalate, 30g 13# aromatic oil, 1g dispersant F127, and 0.3g defoamer DF530 to 95°C, stir and mix for 30 minutes, add 0.2g calcium stearate, 2g montmorillonite powder, and 0.1g 3,3'-dichloro-4,4'-diaminodiphenylmethane, heat to 110°C, stir and mix for 4 hours, add 3g tetramethylbenzene, stir and mix for 30 minutes, add 10g pre-hybridized resin, stir and mix for 1 hour, evenly apply to the surface of consumer electronic motherboard, ventilate and maintain for 96 hours to obtain the waterproof coating for consumer electronic motherboard.

[0047] Example 3

[0048] This embodiment provides a method for preparing a waterproof coating of a consumer electronic motherboard, comprising the following steps:

[0049] S1. Preparation of vinyl oligosilazane: Under nitrogen protection, 0.6 mol MeHSiCl 2 、0.3molMe 3 SiCl, 0.2 mol MeViSiCl 2 、0.1mol MeSiCl 3 Mix well, introduce ammonia at a flow rate of 40 mL / min, heat to 35°C, stir to react for 4 h, filter, wash, and dry the filtrate to obtain vinyl oligosilazane;

[0050] S2. Preparation of modified vinyl oligosilazane: 10 g of vinyl oligosilazane was added to 300 mL of ethanol, 2.5 g of silane coupling agent KH570 and 0.15 g of sodium persulfate were added, heated to 45 ° C, stirred for 1.5 h, filtered, washed, and dried to obtain modified vinyl oligosilazane;

[0051] S3. Hydrolysis: 10 g of modified vinyl oligosilazane was added to 200 mL of water, heated to 85 ° C, stirred for hydrolysis reaction for 1.5 h, filtered, washed, ball milled for 1 h, and dried to obtain silicon oxide-coated silazane;

[0052] S4. Curing and sintering: 10 g of silicon oxide-coated silazane was added to 1000 ° C under nitrogen protection and calcined for 1.5 h to obtain a hard ceramic material;

[0053] S5. Preparation of modified particles: 10 g of hard ceramic material was added to 200 mL of ethanol, 1.5 g of silane coupling agent KH792 was added, heated to 45 ° C, stirred for 1.5 h, centrifuged, washed, and dried to obtain a modified hard ceramic material;

[0054] S6. Preparation of pre-hybridized resin: 10g of modified hard ceramic material, 5.5g of polyether diol 2020, 17g of 52# chlorinated paraffin were heated to 110 ° C under nitrogen protection, stirred and mixed for 1h, 27g of isocyanate HDI was added, stirred for 3h, 0.15g of drier T22, 4.5g of tetramethylbenzene was added, stirred for 30min, and the material was discharged to obtain a pre-hybridized resin;

[0055] S7. Preparation of waterproof coating for consumer electronic motherboard: Heat 6g polyether diol 2020, 12g 52# paraffin, 1.5g dibutyl phthalate, 27g 13# aromatic oil, 0.7g dispersant F127, and 0.25g defoamer DF530 to 95°C, stir and mix for 30 minutes, add 0.15g calcium stearate, 1.5g montmorillonite powder, and 0.07g 3,3'-dichloro-4,4'-diaminodiphenylmethane, heat to 110°C, stir and mix for 4 hours, add 2.5g tetramethylbenzene, stir and mix for 30 minutes, add 10g pre-hybridized resin, stir and mix for 1 hour, evenly apply to the surface of the consumer electronic motherboard, ventilate and maintain for 96 hours to obtain the waterproof coating for the consumer electronic motherboard.

[0056] Comparative Example 1

[0057] Compared with Example 3, the difference is that steps S2 and S3 are not performed.

[0058] Comparative Example 2

[0059] Compared with Embodiment 3, the difference is that step S5 is not performed.

[0060] Comparative Example 3

[0061] Compared with Example 3, the difference is that no modified hard ceramic material is added in step S6.

[0062] Comparative Example 4

[0063] Compared with Example 3, the difference is that in step S6, the modified hard ceramic material is replaced by an equal amount of modified silicon dioxide.

[0064] The preparation method of the modified silica is as follows: 10 g of nano-silica microspheres with an average particle size of 500 nm are added to 200 mL of ethanol, 2 g of KH550 is added, the mixture is heated to 40° C., stirred for reaction for 2 h, centrifuged, washed, and dried to obtain the modified silica.

[0065] Test Example 1

[0066] The waterproof coatings of the consumer electronic mainboards prepared in Examples 1-3 and Comparative Examples 1-4 were subjected to the following performance tests, and the results are shown in Table 1.

[0067] Wear resistance test: The coating wear resistance test is carried out according to GB / T1768-2006.

[0068] Pencil hardness: According to the method of GB / T6739-2006, use pencils with gradually increasing hardness to draw across the coating surface at a 45° angle, and then observe the integrity of the coating surface until the coating surface is indented, scratched, or scratched. The hardness of the previous pencil is the hardness of the tested coating.

[0069] Adhesion test: According to the GB1720-2020 method, the coating integrity within the range of the circular roller line scratch is rated.

[0070] Contact angle test: The contact angle test was performed using an OCA40 contact angle meter from DataPhysics Instruments of Germany.

[0071] Table 1

[0072] Group Pencil hardness (H) Adhesion(grade) Wear resistance (g) Water contact angle (°) Example 1 6 1 0.013 112 Example 2 6 1 0.012 109 Example 3 6 1 0.010 115 Comparative Example 1 4 2 0.088 104 Comparative Example 2 4 2 0.094 105 Comparative Example 3 2 3 0.244 95 Comparative Example 4 5 1 0.032 98

[0073] It can be seen from the above table that the waterproof coatings of the consumer electronic mainboards prepared in Examples 1-3 of the present invention have good comprehensive performance.

[0074] Test Example 2

[0075] The waterproof coatings of the consumer electronic mainboards prepared in Examples 1-3 and Comparative Examples 1-4 were subjected to mechanical property tests at a tensile speed of 500 mm / min and a test temperature of 25° C. The results are shown in Table 2.

[0076] Table 2

[0077] Group Tensile strength(MPa) Elongation at break (%) Example 1 6.05 752 Example 2 6.03 749 Example 3 6.09 755 Comparative Example 1 5.78 705 Comparative Example 2 5.69 687 Comparative Example 3 4.10 479 Comparative Example 4 5.45 662

[0078] It can be seen from the above table that the waterproof coatings of the consumer electronic mainboards prepared in Examples 1-3 of the present invention have good mechanical properties.

[0079] Test Example 3

[0080] The waterproof coatings of the consumer electronic mainboards prepared in Examples 1-3 and Comparative Examples 1-4 were subjected to the following performance tests, and the results are shown in Table 3.

[0081] The neutral salt spray resistance test is carried out in accordance with the provisions of GB / T1771-2007 "Determination of neutral salt spray resistance of paints and varnishes". The mass concentration of the sodium chloride solution is (50±5) g / L and the pH is 6.7±2.

[0082] The acid resistance is tested according to the immersion method specified in GB / T9274-1988 "Determination of resistance of paints and varnishes to liquid media", with a sulfuric acid mass fraction of 5%. Defects are observed after immersion for 24 hours.

[0083] The organic solvent resistance test is carried out according to the manual wiping method specified in GB / T23989-2009 "Determination of Solvent Resistance of Coatings by Wiping". Wipe back and forth 25 times with a finger wrapped in absorbent cotton to observe whether it is damaged and the base material is exposed.

[0084] The water resistance test refers to GB / T1733-1993 "Determination of water resistance of paint film", the test temperature is 40℃, and the test time is 24h.

[0085] Table 3

[0086]

[0087] It can be seen from the above table that the waterproof coatings of the consumer electronic mainboards prepared in Examples 1-3 of the present invention have good acid resistance, water resistance, salt spray resistance, and organic solvent resistance.

[0088] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A method for preparing a waterproof coating for a consumer electronic motherboard, characterized in that: The following steps are involved: S1. Preparation of vinyl oligosilazane: Under inert gas protection, MeHSiCl2, Me3SiCl, MeViSiCl2, MeSiCl3 were mixed uniformly, ammonia was introduced, the reaction was heated with stirring, filtered, washed, and the filtrate was dried to obtain vinyl oligosilazane; S2. Preparation of modified vinyl oligosilazane: adding vinyl oligosilazane to ethanol, adding a silane coupling agent and an initiator, heating and stirring the reaction, filtering, washing, and drying to obtain modified vinyl oligosilazane; S3. Hydrolysis: adding the modified vinyl oligosilazane to water, heating for hydrolysis, stirring for reaction, filtering, washing, ball milling, and drying to obtain silicon oxide-coated silazane; S4. Curing and sintering: calcining the silicon oxide-coated silazane under inert gas protection to obtain a hard ceramic material; S5. Preparation of modified particles: adding a hard ceramic material to ethanol, adding a silane coupling agent having an amino group, heating and stirring to react, centrifuging, washing, and drying to obtain a modified hard ceramic material; S6. Preparation of pre-hybridized resin: The modified hard ceramic material, polyether diol, and chlorinated paraffin are heated and stirred under inert gas protection, isocyanate is added, the reaction is stirred, a drying agent and tetramethylbenzene are added, stirred, and the material is discharged to obtain a pre-hybridized resin; S7. Preparation of waterproof coating for consumer electronic motherboard: heat and stir polyether diol, paraffin, dibutyl phthalate, aromatic oil, dispersant and defoaming agent, add calcium stearate, montmorillonite powder and 3,3'-dichloro-4,4'-diaminodiphenylmethane, heat and stir, add tetramethylbenzene, stir and mix evenly, add pre-hybridized resin, stir and mix evenly, apply evenly to the surface of consumer electronic motherboard, ventilate and maintain, to obtain waterproof coating for consumer electronic motherboard.

2. The preparation method according to claim 1, characterized in that: The molar ratio of MeHSiCl2, Me3SiCl, MeViSiCl2 and MeSiCl3 in step S1 is 5-7:2-4:1-3:1, the ventilation rate of ammonia is 30-50 mL / min, the temperature of the heating and stirring reaction is 30-40°C, and the time is 3-5 h.

3. The preparation method according to claim 1, characterized in that: The mass ratio of the vinyl oligosilazane, the silane coupling agent and the initiator in step S2 is 10:2-3:0.1-0.2, the temperature of the heating and stirring reaction is 40-50°C, the time is 1-2h, the silane coupling agent is selected from at least one of KH570, A151, and A171, and the initiator is selected from at least one of ammonium persulfate, potassium persulfate, and sodium persulfate.

4. The preparation method according to claim 1, characterized in that: The temperature of the heating hydrolysis in step S3 is 80-90° C. and the time is 1-2 h.

5. The preparation method according to claim 1, characterized in that: The calcination temperature in step S4 is 800-1200° C. and the calcination time is 1-2 h.

6. The preparation method according to claim 1, characterized in that: In step S5, the mass ratio of the hard ceramic material to the silane coupling agent with amino group is 10:1-2, the temperature of the heating and stirring reaction is 40-50° C., the time is 1-2h, and the silane coupling agent with amino group is selected from at least one of KH550, KH602, and KH792.

7. The preparation method according to claim 1, characterized in that: The mass ratio of the modified hard ceramic material, polyether diol, chlorinated paraffin, isocyanate, drying agent and tetramethylbenzene in step S6 is 10:4-7:15-20:25-30:0.1-0.2:3-5, the polyether diol is polyether diol 2020 or polyether diol 3135, the drying agent is drying agent T12 or drying agent T22, and the isocyanate is at least one of toluene diisocyanate, isophorone diisocyanate, diphenylmethane diisocyanate, dicyclohexylmethane diisocyanate and hexamethylene diisocyanate.

8. The preparation method according to claim 1, characterized in that: The polyether diol in step S7 is polyether diol 2020 or polyether diol 3135, and the mass ratio of the polyether diol, paraffin, dibutyl phthalate, aromatic oil, dispersant, defoamer, calcium stearate, montmorillonite powder, 3,3'-dichloro-4,4'-diaminodiphenylmethane, tetramethylbenzene, and pre-hybridized resin is 5-7:10-15:1-2:25-30:0.5-1:0.2-0.3:0.1-0.2:1-2:0.05-0.1:2-3:10, and the ventilation curing time is 48-96h.

9. A waterproof coating for a consumer electronic mainboard prepared by the preparation method according to any one of claims 1 to 8.

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