Ultra-corrosion-resistant ultraviolet light-moisture curing conformal coating as well as preparation method and application thereof

Abstract

The invention discloses ultra-corrosion-resistant ultraviolet light-moisture curing conformal coating, which is prepared from the following raw materials in parts by weight: 30 to 60 parts of light-cured resin; 1-3 parts of a reactive leveling agent; 30 to 60 parts of an acrylate active monomer; 0.5 to 3 parts of a defoaming agent; 1-5 parts of a coupling agent; 0.3-2 parts of a dehydrating agent; 2-8 parts of a photoinitiator; the light-cured resin is prepared according to the following steps: (a) polycarbonate diol, hexamethylene diisocyanate and dibutyltin dilaurate are subjected to a reaction at 70-90 DEG C, and a polymerization mixture is obtained; and (b) sequentially adding a hydroxyethyl acrylate mixed solution and p-toluenesulfonyl isocyanate into the polymerization mixture to enable the molar ratio of the isocyanate group to the hydroxyl group to be 1: (0.3-0.7), and reacting at 50-70 DEG C, thereby obtaining the polyurethane adhesive. Light / moisture dual curing can be achieved, and the advantages of being good in yellowing resistance, high and low temperature resistance, salt fog resistance and the like are achieved.

Description

Technical Field

[0001] The invention belongs to the technical field of coatings, and relates to an ultraviolet light-moisture dual-curing conformal coating, and specifically relates to an ultra-corrosion-resistant ultraviolet light-moisture dual-curing conformal coating, and a preparation method and application thereof. Background Art

[0002] Conformal coating is a protective coating applied to printed circuit boards with soldered plug-in components. It can protect electronic products from harmful external environments (such as dust, moisture, chemicals, mildew corrosion, foreign object scratches, short circuits and other human operating errors), and can also extend the life of electronic devices and improve the stability of use, thereby improving the performance of electronic products. In addition to being used in the electronics industry, conformal coatings are also widely used in the automotive industry, aerospace industry, defense industry and bioengineering.

[0003] The use of light-curing conformal coatings can greatly improve the coating production efficiency of circuit boards, and it is also convenient for repairing circuit boards and local rapid coating protection. However, the curing of small area shadows has become a key issue that restricts the promotion and application of this technology to various types of complex circuit boards. Therefore, the conformal coatings currently developed all adopt a dual curing mechanism that can be cured under light and dark conditions. It can not only ensure that most areas of the circuit board are cured quickly, which is convenient for the implementation of subsequent processes, but also ensure that a small amount of shadow areas are completely cured in a short period of time. It not only improves the production efficiency of circuit board coating, but also ensures the comprehensive curing of conformal coatings. It can be applied to the coating protection of various complex types of circuit boards. Common dual curing methods include light-heat curing, light-moisture, light-chemical, and light-chemical-air curing.

[0004] The Chinese invention patent with application number 202010571967.0 discloses a UV-moisture dual-curing conformal coating, its preparation method and application. The conformal coating comprises a modified polyurethane resin, wherein the molar mass ratio of carbon-carbon double bonds, isocyanate groups and silicon-oxygen bonds in the modified polyurethane resin is (5-7): (10-13): 1. The conformal coating has the characteristics of environmental protection and safety, fast curing speed, good high temperature resistance and water and solvent resistance, which helps to improve the reliability and service life of circuit board products.

[0005] The Chinese invention patent with application number 202211272151.3 discloses a light-moisture dual-curing liquid thermal conductive tape and its preparation method and application. The raw material composition of the light-moisture dual-curing liquid thermal conductive tape includes the following components in parts by weight: 5-25 parts of curing resin, 5-10 parts of tackifying resin, 55-80 parts of filler, 5-10 parts of acrylate active monomer, 0.5-3 parts of dehydrating agent, 0.5-3 parts of defoaming agent, 0.3-1 part of leveling agent, and 3-8 parts of photoinitiator. The thermal conductive tape of this application can be used for potting of various electronic devices, overcoming the problems of small curing thickness caused by excessive fillers in the prior art and the problem that the light-moisture curing system in the current market will produce bubbles when the curing thickness is too thick, resulting in a decrease in thermal conductivity.

[0006] Although the existing UV-moisture dual-curing conformal coatings can generally meet the application requirements in the field of electronic components, the current automotive application market has put forward higher requirements: in the application environment of high salt spray resistance and high chemical resistance, the conformal coating needs to have a longer conformal effect and a thinner spray thickness, and the existing products cannot meet the requirements. Summary of the invention

[0007] In order to solve the above technical problems, the object of the present invention is to provide a super corrosion-resistant UV-moisture dual-curing conformal coating.

[0008] In order to achieve the above object, the present invention provides a super corrosion-resistant UV-moisture curing conformal coating, the raw materials of which include the following components in parts by weight:

[0009] 30-60 parts of light-curing resin;

[0010] 1 to 3 parts of reactive leveling agent;

[0011] 30-60 parts of acrylate reactive monomer;

[0012] Defoaming agent 0.5-3 parts;

[0013] 1 to 5 parts of coupling agent;

[0014] 0.3-2 parts of dehydrating agent;

[0015] 2 to 8 parts of photoinitiator;

[0016] The photocurable resin is prepared according to the following steps:

[0017] (a) reacting polycarbonate diol, hexamethylene diisocyanate and dibutyltin dilaurate at 70 to 90° C. to obtain a polymerization mixture; the molar ratio of the isocyanate group in the hexamethylene diisocyanate to the hydroxyl group in the polycarbonate diol is 1.5 to 4.5:1;

[0018] (b) adding a hydroxyethyl acrylate mixed solution and p-toluenesulfonyl isocyanate to the polymerization mixture in sequence so that the molar ratio of the isocyanate group to the hydroxyl group is 1:0.3-0.7, and reacting at 50-70°C; the hydroxyethyl acrylate mixed solution has dibutyltin dilaurate and hydroquinone as solutes and hydroxyethyl acrylate as solvent.

[0019] Optimally, in step (a), the amount of dibutyltin dilaurate used is 0.02-0.03% of the mass of the polycarbonate diol.

[0020] Furthermore, in step (a), the polycarbonate diol is vacuum dehydrated at 100-120° C. for 2-4 hours before use.

[0021] Optimally, in step (b), the amount of dibutyltin dilaurate is 0.03-0.05% of the mass of the polycarbonate diol, the amount of hydroquinone is 0.2-0.5% of the sum of the mass of the polycarbonate diol and the hexamethylene diisocyanate, and the amount of p-toluenesulfonyl isocyanate is 0.3-0.8% of the sum of the mass of the polycarbonate diol and the hexamethylene diisocyanate.

[0022] Optimally, the reactive leveling agent is prepared according to the following steps: adding terminal hydroxyl silicone oil, trimethylolpropane triacrylate and solvent into a reaction container, passing nitrogen for protection under stirring conditions, adding 10-30ppm isopropanol solution of chloroplatinic acid and hydroquinone, heating to 80-100°C for reaction, and removing the solvent by reduced pressure distillation; the amount of hydroquinone added is 0.2-0.5% of the sum of the mass of the terminal hydroxyl silicone oil and trimethylolpropane triacrylate.

[0023] Optimally, the acrylate reactive monomer is a mixture of one or more selected from isooctyl acrylate, isobornyl methacrylate, isobornyl acrylate, hydroxyethyl acrylate, 4-hydroxybutyl acrylate, N,N-dimethylacrylamide, 2-phenoxyethyl acrylate, cyclotrimethylolpropane formal acrylate, 1,6-hexanediol diacrylate and tetrahydrofuran acrylate.

[0024] Optimally, the defoaming agent is at least one selected from polyether, polyacrylate, polydimethylsilicone and polysiloxane; the coupling agent is a mixture of one or more selected from silane coupling agent, titanate coupling agent, aluminate coupling agent, metal composite coupling agent and phosphate coupling borate coupling agent; the dehydrating agent is a mixture of one or more selected from toluenesulfonyl isocyanate, 3-butyl-2-(1-ethylpentyl) oxazolidine, and triethyl orthoformate; the photoinitiator is a mixture of one or more selected from 2,4,6-trimethylbenzoyl-diphenylphosphine oxide, 2-hydroxy-2-methyl-1-phenyl-1-propanone, 1-hydroxy-cyclohexyl-phenyl ketone, 2,4,6-trimethylbenzoylphenylphosphonic acid ethyl ester and methyl benzoylformate.

[0025] Another object of the present invention is to provide a method for preparing the above-mentioned ultra-corrosion-resistant UV-moisture-curing conformal coating, comprising the following steps:

[0026] The light-curable resin and the acrylic acid ester active monomer are mixed and stirred for 1 hour to 3 hours; then the defoamer, reactive leveling agent and coupling agent are added and stirred for 0.5 hours to 1 hour;

[0027] Then add the formulated amount of photoinitiator and dehydrating agent, evacuate the chamber, maintain the pressure and stir for 1h-3h; vacuum defoam and discharge the material.

[0028] Another object of the present invention is to provide an application of the above-mentioned ultra-corrosion-resistant UV-moisture-curing conformal paint for spraying on the surface of a PCB electronic circuit board for conformal protection.

[0029] Optimally, the ultra-corrosion-resistant UV-moisture-curing conformal coating is coated on the PCB circuit board, and the light reaction is completed for 5 seconds to 120 seconds to complete the curing so as to cover and protect the circuit board.

[0030] The ultra-corrosion-resistant UV-moisture-curing conformal paint of the present invention can realize light / moisture dual curing by adopting a homemade light-curing resin in combination with components such as an acrylate active monomer, a photoinitiator, a defoamer, a reactive leveling agent, and a coupling agent, and has the advantages of good yellowing resistance, high and low temperature resistance, salt spray resistance, and the like, and effectively improves the adhesion; combined with the homemade reactive leveling agent, it has the low surface energy of silicone and the rapid curing of the acrylate trifunctional monomer, and can further promote the colloid surface to be more resistant to stains and acid and alkali erosion. DETAILED DESCRIPTION

[0031] The ultra-corrosion-resistant UV-moisture-curing conformal paint of the present invention is characterized in that its raw materials include the following components in parts by weight: 30 to 60 parts of a photocurable resin; 1 to 3 parts of a reactive leveling agent; 30 to 60 parts of an acrylate active monomer; 0.5 to 3 parts of a defoaming agent; 1 to 5 parts of a coupling agent; 0.3 to 2 parts of a dehydrating agent; and 2 to 8 parts of a photoinitiator; the photocurable resin is prepared according to the following steps: (a) reacting polycarbonate diol, hexamethylene diisocyanate and dibutyltin dilaurate at 70 to 90° C. to obtain a polymerization mixture (the reaction vessel is a four-mouth reflux reactor equipped with a stirrer, a thermometer, a condensation reflux device and a high-purity nitrogen reflux device) Flask, heating method is oil bath; the reaction is an exothermic reaction, the heat source height needs to be adjusted according to the thermometer reading in the early stage, preferably the temperature is stabilized at 80℃ for 4h); the molar ratio of the isocyanate group in the hexamethylene diisocyanate to the hydroxyl group in the polycarbonate diol is 1.5-4.5:1; (b) hydroxyethyl acrylate mixed solution and p-toluenesulfonyl isocyanate are added to the polymerization mixture in sequence to make the molar ratio of the isocyanate group to the hydroxyl group be 1:0.3-0.7, and the reaction is carried out at 50-70℃; the hydroxyethyl acrylate mixed solution uses dibutyltin dilaurate and hydroquinone as solutes and hydroxyethyl acrylate as solvent. By using a self-made light-curing resin and acrylic acid ester active monomers, photoinitiators, defoamers, reactive leveling agents, coupling agents and other components, light / moisture dual curing can be achieved, which has good yellowing resistance, high and low temperature resistance, salt spray resistance and other advantages, and effectively improves the adhesion.

[0032] In step (a), the amount of dibutyltin dilaurate is preferably 0.02-0.03% of the mass of the polycarbonate diol. The polycarbonate diol is preferably dehydrated under vacuum at 100-120°C for 2-4 hours before use. In step (b), the amount of dibutyltin dilaurate is preferably 0.03-0.05% of the mass of the polycarbonate diol, the amount of hydroquinone is preferably 0.2-0.5% of the sum of the mass of the polycarbonate diol and the hexamethylene diisocyanate, and the amount of p-toluenesulfonyl isocyanate is preferably 0.3-0.8% of the sum of the mass of the polycarbonate diol and the hexamethylene diisocyanate.

[0033] The reactive leveling agent is prepared according to the following steps: adding terminal hydroxyl silicone oil, trimethylolpropane triacrylate and solvent (such as xylene) into a reaction container, passing nitrogen gas for protection under stirring conditions, adding 10-30ppm isopropanol solution of chloroplatinic acid and hydroquinone, heating to 80-100°C for reaction, and removing the solvent by reduced pressure distillation; the amount of hydroquinone added is 0.2-0.5% of the sum of the mass of the terminal hydroxyl silicone oil and trimethylolpropane triacrylate. In this way, the self-made reactive leveling agent has the low surface energy of silicone and the rapid curing of acrylate trifunctional monomers, which can further promote the colloid surface to be more resistant to pollution and acid and alkali erosion.

[0034] The acrylic acid ester reactive monomer is a mixture of one or more selected from the group consisting of isooctyl acrylate, isobornyl methacrylate, isobornyl acrylate, hydroxyethyl acrylate, 4-hydroxybutyl acrylate, N,N-dimethylacrylamide, 2-phenoxyethyl acrylate, cyclotrimethylolpropane formal acrylate, 1,6-hexanediol diacrylate and tetrahydrofuran acrylate. The defoaming agent is at least one selected from polyether, polyacrylate, polydimethyl silicone oil and polysiloxane; the coupling agent is a mixture of one or more selected from silane coupling agent, titanate coupling agent, aluminate coupling agent, metal composite coupling agent and phosphate coupling borate coupling agent; the dehydrating agent is a mixture of one or more selected from p-toluenesulfonyl isocyanate, 3-butyl-2-(1-ethylpentyl) oxazolidine and triethyl orthoformate; the photoinitiator is a mixture of one or more selected from 2,4,6-trimethylbenzoyl-diphenylphosphine oxide, 2-hydroxy-2-methyl-1-phenyl-1-propanone, 1-hydroxy-cyclohexyl-phenyl ketone, ethyl 2,4,6-trimethylbenzoylphenylphosphonate and methyl benzoylformate.

[0035] The preparation method of the above-mentioned ultra-corrosion-resistant UV-moisture-curing conformal paint comprises the following steps: mixing and stirring the formulated amount of the photocurable resin and the acrylate active monomer for 1h-3h; then adding the formulated amount of the defoamer, reactive leveling agent, and coupling agent, and stirring for 0.5h-1h; then adding the formulated amount of the photoinitiator and dehydrating agent, evacuating, and stirring at pressure for 1h-3h; vacuum defoaming and discharging.

[0036] The application of the ultra-corrosion-resistant UV-moisture-curing three-proof paint is used for spraying on the surface of PCB electronic circuit boards for conformal protection. Specifically, the ultra-corrosion-resistant UV-moisture-curing three-proof paint is applied on the PCB circuit board, and the light reaction is completed for 5 seconds to 120 seconds to complete the curing to cover and protect the circuit board; wherein, the light band is a mixture of one or several of the bands of 200nm to 760nm of mercury lamp or UV LED lamp; preferably, the light band is a mixture of one or several of the bands of 250nm to 500nm of mercury lamp or UV LED lamp; more preferably, the light band is a mixture of one or several of the bands of 300nm to 405nm of mercury lamp or UV LED lamp.

[0037] In order to enable those skilled in the art to better understand the present invention, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the embodiments. Obviously, the described embodiments are only embodiments of a part of the present invention, rather than all embodiments. Based on the embodiments of the present invention, all other embodiments obtained under the premise of equivalent changes and modifications made by ordinary technicians in the field should belong to the scope of protection of the present invention.

[0038] Example 1

[0039] This embodiment provides a super corrosion-resistant UV-moisture curing conformal coating, which is as follows:

[0040] 45g of photocurable resin, 3g of coupling agent, 40g of acrylate reactive monomer, 3g of defoaming agent, 1g of reactive leveling agent, 2g of dehydrating agent and 6g of photoinitiator;

[0041] The preparation of the above-mentioned photocurable resin comprises the following steps:

[0042] (a) A four-necked flask equipped with a stirrer, a thermometer, a condensation reflux device and a high-purity nitrogen reflux device is used, and the heating method is an oil bath; first, polycarbonate diol 1000 (100 g) is added to the flask, and vacuum dehydrated at 110°C for 2 hours, and then the temperature is reduced to 75°C; then a mixed solution of hexamethylene diisocyanate (200 g) and dibutyltin dilaurate (0.025 g, 0.025 wt% of polycarbonate diol 1000) is added to the flask, and the temperature is stabilized at 80°C for 4 hours (the reaction is an exothermic reaction, and the heat source height needs to be adjusted according to the thermometer reading in the early stage).

[0043] (b) dissolving 0.03 wt % (based on the mass of the aforementioned polycarbonate diol) of dibutyltin dilaurate and 0.03 w % (based on the sum of the masses of the polycarbonate diol and hexamethylene diisocyanate) of hydroquinone in hydroxyethyl acrylate (360 ml) to obtain a hydroxyethyl acrylate mixed solution;

[0044] Add the hydroxyethyl acrylate mixed liquid and 0.5wt% (based on the sum of the masses of polycarbonate diol and hexamethylene diisocyanate) of p-toluenesulfonyl isocyanate into the flask successively (make sure the system is well sealed and keep the molar ratio of isocyanate group to hydroxyl group at 1:0.5). Pay attention to controlling the temperature so that the reaction continues at 50°C for 3 hours, then discharge and cool (that is, the product is isocyanate-modified polyurethane acrylate).

[0045] The preparation of the reactive leveling agent comprises the following steps: adding a calculated amount of hydrogenated silicone oil (hydroxy-terminated silicone oil, 50 g), trimethylolpropane triacrylate (100 g) and xylene solvent (350 g) into a four-necked flask, stirring and passing nitrogen for protection; adding a 10 ppm isopropanol solution of chloroplatinic acid (4 g) and 0.3% (mass fraction) of hydroquinone (1.5 g), heating to 80° C., reacting for 6 h, stopping the reaction, and removing the solvent by reduced pressure distillation to obtain a reactive leveling agent.

[0046] The acrylate active monomer is composed of the following components by weight: 30g of isobornyl acrylate, 5g of N,N-dimethylacrylamide and 5g of 2-phenoxyethyl acrylate; the defoamer is a polyether defoamer (SN5710 of Shenzhu Chemical Industry); the dehydrating agent is p-toluenesulfonyl isocyanate; the coupling agent is a silane coupling agent KH570; the photoinitiator is composed of the following components by weight: 5g of 2,4,6-trimethylbenzoyl-diphenylphosphine oxide and 1g of 1-hydroxy-cyclohexyl-phenyl ketone.

[0047] The preparation method and application of ultra-corrosion-resistant UV-moisture-curing conformal coatings are as follows, at normal temperature and pressure, in a yellow light room or in a light-shielding environment:

[0048] S1. Mix the formulated amount of photocurable resin and acrylate active monomer and stir for 2 hours; then add the formulated amount of defoamer, reactive leveling agent and coupling agent and stir for 1 hour;

[0049] S2, add the formulated amount of photoinitiator and dehydrating agent, evacuate, stir under pressure for 3 hours, evacuate to -0.1MPa (measured by the instrument produced by China Leierda Instrument Co., Ltd., No. YL10207224), stir under pressure for 2 hours; then defoam and discharge by vacuum;

[0050] S3, then the ultra-corrosion-resistant UV moisture-curing conformal paint is coated on the PCB circuit board, and then placed in a light-curing device for light reaction for 60 seconds to initiate the curing of the glue to obtain a UV moisture-curing conformal paint (the UV curing light source can be a 1000W medium-pressure mercury lamp with a light intensity of 80mw / cm 2 , the center wavelength of effective light radiation is 365nm).

[0051] Example 2

[0052] This embodiment provides a method for preparing a super corrosion-resistant UV moisture-curing conformal coating and its application, which is basically the same as that in Example 1, except that: 60 g of photocurable resin, 3 g of coupling agent, 30 g of acrylate reactive monomer (including 20 g of isobornyl acrylate, 5 g of N,N-dimethylacrylamide and 5 g of 2-phenoxyethyl acrylate), 0.5 g of defoamer, 1.5 g of reactive leveling agent, 1 g of dehydrating agent, 4 g of photoinitiator (including 3 g of 2,4,6-trimethylbenzoyl-diphenylphosphine oxide and 1 g of 1-hydroxy-cyclohexyl-phenyl ketone).

[0053] Example 3

[0054] This embodiment provides a method for preparing a super corrosion-resistant UV moisture-curing conformal coating and its application, which is basically the same as that in Example 1, except that: 30 g of photocurable resin, 2 g of coupling agent, 60 g of acrylate reactive monomer (including 40 g of isobornyl acrylate, 10 g of N,N-dimethylacrylamide and 10 g of 2-phenoxyethyl acrylate), 1 g of defoamer, 2 g of reactive leveling agent, 1 g of dehydrating agent, 4 g of photoinitiator (including 3 g of 2,4,6-trimethylbenzoyl-diphenylphosphine oxide and 1 g of 1-hydroxy-cyclohexyl-phenyl ketone).

[0055] Example 4

[0056] This embodiment provides a method for preparing a super corrosion-resistant UV moisture-curing conformal coating and its application, which is basically the same as that in Example 1, except that the photoinitiator is 8 g of 2,4,6-trimethylbenzoyl-diphenylphosphine oxide.

[0057] Example 5

[0058] This embodiment provides a method for preparing a super corrosion-resistant UV moisture-curing conformal coating and its application, which is basically the same as that in Example 1, except that the dehydrating agent is 2 g of p-toluenesulfonyl isocyanate.

[0059] Comparative Example 1

[0060] This example provides a method for preparing a UV moisture-curing conformal coating and its application, which is basically the same as that in Example 1, except that the light-curing resin is commercially available Sartomer CN1073NS.

[0061] Comparative Example 2

[0062] This example provides a method for preparing a UV moisture-curing conformal coating and its application, which is basically the same as that in Example 1, except that no reactive leveling agent is added.

[0063] Comparative Example 3

[0064] This example provides a method for preparing a UV moisture-curing conformal coating and its application, which is basically the same as that in Example 1, except that the amount of photocurable resin is in excess of 80 g.

[0065] Comparative Example 4

[0066] This example provides a method for preparing a UV moisture-curing conformal coating and its application, which is basically the same as that in Example 1, except that the reactive leveling agent is used in excess of 10 g.

[0067] The UV / curable conformal coatings of Examples 1 to 5, Comparative Examples 1 to 4, and existing Elygo UVCL series products were subjected to performance tests such as hardness, contact angle, hundred-grid knife, high temperature and high humidity double 85 aging test, hot and cold shock aging test, salt spray resistance test, acid and alkali resistance test, and the test results are shown in Table 1.

[0068] The specific test method is as follows:

[0069] Appearance: Visually inspect the colloid color after curing;

[0070] Hardness: Tested according to Shaw HD standard;

[0071] Contact angle: tested according to GB / T 30693-2014 standard;

[0072] 100-grid test: in accordance with GB / T9286-2021 "Scratching test for paint and varnish";

[0073] High temperature and high humidity double 85 aging test: IPC-TM-650 2.6.3 standard;

[0074] Thermal shock aging test: IPC-TM-650 2.6.7.1 standard "Thermal shock resistance of conformal coating";

[0075] Salt spray resistance test: GB / T6461-1979 "Rating of samples and specimens of metal and other inorganic coatings on metal substrates after corrosion tests";

[0076] Acid and alkali resistance test: GB / T1981.2-2009 "Electrical insulation paint Part 2: Test method".

[0077] Table 1 Performance of three anti-corrosion paint in Examples 1-5 and Comparative Examples 1-4

[0078]

[0079] As can be seen from Table 1, the ultra-corrosion-resistant UV moisture-curing conformal coatings prepared in Examples 1-5 of the present invention have a light yellow transparent appearance, good adhesion, large contact angle, and good aging resistance at a wavelength of 270-800nm; compared with existing products, they have good application prospects. Among them, Comparative Example 1 is a purchased isocyanate-modified polyurethane acrylate replaced by a self-synthesized isocyanate-modified polyurethane acrylate, which has high hardness, low contact angle, and poor aging resistance in particular; the test results of Comparative Example 2 show that if no leveling agent is added, the contact angle will decrease and the aging resistance is poor; Comparative Example 3 shows that increasing the resin ratio will reduce the hardness and high temperature and high humidity; the test results of Comparative Example 4 show that increasing the leveling agent ratio has an effect on the hardness, contact angle, and cold and hot shock.

[0080] The above description is only a preferred embodiment of the present invention and is not intended to limit the scope of protection of the present invention. At the same time, the above description should be understandable and implementable for those with ordinary knowledge in the relevant technical field. Therefore, other equivalent changes or modifications that do not deviate from the concepts disclosed in the present invention should be included in the scope of protection of the present invention.

Claims

1. A super corrosion resistant UV-moisture curing conformal coating, characterized in that: Its raw materials include the following components in parts by weight: 30~60 parts of light-curing resin; 1~3 parts of reactive leveling agent; 30-60 parts of acrylate reactive monomer; Defoaming agent 0.5~3 parts; 1~5 parts of coupling agent; Dehydrating agent 0.3~2 parts; 2~8 parts of photoinitiator; The photocurable resin is prepared according to the following steps: (a) reacting polycarbonate diol, hexamethylene diisocyanate and dibutyltin dilaurate at 70-90° C. to obtain a polymerization mixture; the molar ratio of the isocyanate group in the hexamethylene diisocyanate to the hydroxyl group in the polycarbonate diol is 1.5-4.5:1; (b) adding a hydroxyethyl acrylate mixed solution and p-toluenesulfonyl isocyanate to the polymerization mixture in sequence so that the molar ratio of the isocyanate group to the hydroxyl group is 1:0.3-0.7, and reacting at 50-70°C; the hydroxyethyl acrylate mixed solution has dibutyltin dilaurate and hydroquinone as solutes and hydroxyethyl acrylate as solvent.

2. The ultra-corrosion resistant UV-moisture curing conformal coating according to claim 1, characterized in that: In step (a), the amount of dibutyltin dilaurate used is 0.02-0.03% of the mass of the polycarbonate diol.

3. The ultra-corrosion resistant UV-moisture curing conformal coating according to claim 1 or 2, characterized in that: In step (a), the polycarbonate diol is vacuum dehydrated at 100-120° C. for 2-4 hours before use.

4. The ultra-corrosion resistant UV-moisture curing conformal coating according to claim 1, characterized in that: In step (b), the amount of dibutyltin dilaurate is 0.03-0.05% of the mass of the polycarbonate diol, the amount of hydroquinone is 0.2-0.5% of the sum of the mass of the polycarbonate diol and the hexamethylene diisocyanate, and the amount of p-toluenesulfonyl isocyanate is 0.3-0.8% of the sum of the mass of the polycarbonate diol and the hexamethylene diisocyanate.

5. The ultra-corrosion resistant UV-moisture curing conformal coating according to claim 1, characterized in that: The reactive leveling agent is prepared according to the following steps: adding terminal hydroxyl silicone oil, trimethylolpropane triacrylate and a solvent into a reaction container, passing nitrogen gas for protection under stirring conditions, adding 10-30 ppm isopropanol solution of chloroplatinic acid and hydroquinone, heating to 80-100° C. for reaction, and removing the solvent by reduced pressure distillation; the amount of the hydroquinone added is 0.2-0.5% of the sum of the mass of the terminal hydroxyl silicone oil and the trimethylolpropane triacrylate.

6. The ultra-corrosion resistant UV-moisture curing conformal coating according to claim 1, characterized in that: The acrylic acid ester reactive monomer is a mixture of one or more selected from the group consisting of isooctyl acrylate, isobornyl methacrylate, isobornyl acrylate, hydroxyethyl acrylate, 4-hydroxybutyl acrylate, N,N-dimethylacrylamide, 2-phenoxyethyl acrylate, cyclotrimethylolpropane formal acrylate, 1,6-hexanediol diacrylate and tetrahydrofuran acrylate.

7. The ultra-corrosion resistant UV-moisture curing conformal coating according to claim 1, characterized in that: The defoaming agent is at least one selected from polyether, polyacrylate, polydimethyl silicone oil and polysiloxane; the coupling agent is a mixture of one or more selected from silane coupling agent, titanate coupling agent, aluminate coupling agent, metal composite coupling agent and phosphate coupling borate coupling agent; the dehydrating agent is a mixture of one or more selected from p-toluenesulfonyl isocyanate, 3-butyl-2-(1-ethylpentyl) oxazolidine and triethyl orthoformate; the photoinitiator is a mixture of one or more selected from 2,4,6-trimethylbenzoyl-diphenylphosphine oxide, 2-hydroxy-2-methyl-1-phenyl-1-propanone, 1-hydroxy-cyclohexyl-phenyl ketone, ethyl 2,4,6-trimethylbenzoylphenylphosphonate and methyl benzoylformate.

8. The method for preparing the ultra-corrosion resistant UV-moisture curing conformal coating according to any one of claims 1 to 7, characterized in that: The following steps are involved: The light-curable resin and the acrylic acid ester active monomer are mixed and stirred for 1 h to 3 h; then the defoamer, reactive leveling agent and coupling agent are added and stirred for 0.5 h to 1 h; Then add the formulated amount of photoinitiator and dehydrating agent, evacuate the chamber, maintain the pressure and stir for 1h-3h; vacuum defoam and discharge the material.

9. The use of the ultra-corrosion resistant UV-moisture curing conformal coating according to any one of claims 1 to 7, characterized in that: Used for spraying on the surface of PCB electronic circuit boards to maintain conformity.

10. The use of the ultra-corrosion resistant UV-moisture curing conformal coating according to claim 9, characterized in that: The ultra-corrosion-resistant UV-moisture-curing conformal coating is coated on the PCB circuit board, and the light reaction is completed within 5 seconds to 120 seconds to complete the curing so as to cover and protect the circuit board.

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