Long-acting fluorescent organosilicon conformal coating and preparation method thereof

Abstract

The invention relates to a long-acting fluorescent organosilicone conformal coating and a preparation method thereof, the long-acting fluorescent organosilicone conformal coating is prepared from 107 glue, 201 silicone oil, a filler, a cross-linking agent, a coupling agent, a compound and a catalyst, and the compound is prepared from 5, 7-dihydroxy-4-methylcoumarin and isocyanate silane through a reaction. The compound is prepared by reacting 5, 7-dihydroxy-4-methylcoumarin with isocyanate silane, and when the compound is used for preparing the three-proofing lacquer, an organic silicon three-proofing lacquer coating has the characteristic of long-lasting fluorescent effect.

Description

Technical Field

[0001] The invention belongs to the technical field of conformal coatings and relates to silicone conformal coatings, and specifically to a long-lasting fluorescent silicone conformal coating and a preparation method thereof. Background Art

[0002] Today's society is in the information revolution represented by electronic information technology, which promotes the development of productivity in an unprecedented way. The development and widespread application of microelectronics technology is a sign of the information revolution. In recent years, printed circuit boards (PCBs), an important carrier material of microelectronics technology, have been developing rapidly. From small chips to large integrated circuits, PCBs play a core role, which inevitably requires higher reliability for PCBs. Since PCBs are always facing a complex working environment, it is very necessary to properly protect their surfaces. Conformal coating (glue) is currently the most common material for protecting PCBs. It uses its self-filming properties to form a coating of tens of microns on the outer layer of the PCB to avoid possible corrosion, softening, deformation, mildew, and other problems on the circuit board, greatly reducing the failure rate of the circuit board circuit.

[0003] From the perspective of chemical composition, conformal coatings can be divided into polyacrylate type, polyurethane type, silicone type, etc. Among them, silicone conformal coatings are soft elastic materials with good temperature resistance and easy repair characteristics, and are high-end conformal coatings for PCB boards. Most of the conformal coatings on the market are colorless and transparent, but they are convenient for coating quality evaluation. Conformal coatings are usually physically compounded with trace amounts of fluorescent powder, and fluorescence occurs on the coating surface under the excitation of ultraviolet light.

[0004] The fluorescence effect of the conformal coating on the PCB will weaken after a period of use. This may be because the heating environment of the PCB causes the phosphor on the surface of the conformal coating to separate from the surface of the system. Therefore, it is necessary to improve the durability of the fluorescence effect of the conformal coating. Summary of the invention

[0005] Based on this, the object of the present invention is to provide a long-lasting fluorescent organosilicon conformal paint which can still effectively detect fluorescence after long-term heat resistance.

[0006] The first aspect of the present invention is to provide a compound, which is prepared by reacting 5,7-dihydroxy-4-methylcoumarin and isocyanate silane; the structural formula of the isocyanate silane is shown in the following formula (I):

[0007]

[0008] Wherein, R is selected from methyl or ethyl.

[0009] In some of the embodiments, the mass ratio of the 5,7-dihydroxy-4-methylcoumarin to the isocyanate silane is (10-20): (10-15).

[0010] In some embodiments, the reaction temperature is 80°C to 90°C.

[0011] In some embodiments, the reaction time is 40 min to 60 min.

[0012] The second aspect of the present invention is to provide a method for preparing the compound as described above, comprising the following steps: reacting 5,7-dihydroxy-4-methylcoumarin and isocyanate silane.

[0013] In some of the embodiments, the mass ratio of the 5,7-dihydroxy-4-methylcoumarin to the isocyanate silane is (10-20): (10N15).

[0014] In some embodiments, the reaction temperature is 80°C to 90°C.

[0015] In some embodiments, the reaction time is 40 min to 60 min.

[0016] In some embodiments, the solvent of the reaction is at least one of toluene, xylene, dimethylformamide, and dimethylacetamide.

[0017] The third aspect of the present invention is to provide the use of the above-mentioned compound as a fluorescent agent in the preparation of conformal coating.

[0018] In some embodiments, the conformal coating is a silicone conformal coating.

[0019] The fourth aspect of the present invention is to provide a silicone conformal coating, which is prepared from the following raw materials in parts by weight:

[0020]

[0021] In some embodiments, the silicone conformal coating is prepared from the following raw materials in parts by weight:

[0022]

[0023] In some embodiments, the 107 glue is α, ω-dihydroxy polydimethylsiloxane with a viscosity of 100 to 10000 mPa·s at 25±0.5°C.

[0024] In some embodiments, the 201 silicone oil is polydimethylsiloxane with a viscosity of 100 to 1000 mPa·s at 25±0.5°C.

[0025] In some embodiments, the filler is at least one of fumed silica and silicone resin. Preferably, the silicone resin is methyl MQ resin.

[0026] In some embodiments, the crosslinking agent is at least one of methyltrimethoxysilane, methyltriethoxysilane, vinyltrimethoxysilane, and vinyltriethoxysilane.

[0027] In some of the embodiments, the coupling agent is at least one of aminopropyltrimethoxysilane, aminopropyltriethoxysilane, glycidoxypropyltrimethoxysilane and glycidoxypropyltriethoxysilane.

[0028] In some of the embodiments, the catalyst is at least one of dibutyltin diacetate and dibutyltin dilaurate.

[0029] A fifth aspect of the present invention is to provide a method for preparing the above-mentioned silicone conformal coating, comprising the following steps:

[0030] (1) Add the 107 glue, 201 silicone oil and filler into a planetary disperser, reduce the vacuum degree to below -0.90 MPa, and stir;

[0031] (2) returning to normal pressure, adding the crosslinking agent, dispersing, reducing the vacuum degree to below -0.90 MPa, and continuing to disperse at the original speed;

[0032] (3) returning to normal pressure, adding the coupling agent and the compound, reducing the vacuum to below -0.95 MPa, and dispersing;

[0033] (4) returning to normal pressure, adding the catalyst, reducing the vacuum to below -0.95 MPa, stirring, and obtaining the product.

[0034] In some embodiments, in step (1), stirring is performed at a speed of 20 r / min-30 r / min for 20 min-30 min; preferably, stirring is performed at a speed of 25 r / min-30 r / min for 25 min-30 min.

[0035] In some embodiments, in step (2), the dispersion is performed at 20 r / min-30 r / min for 20 min-30 min; preferably, the dispersion is performed at 25 r / min-30 r / min for 25 min-30 min.

[0036] In some embodiments, the dispersion is carried out at the original speed for 10 min to 20 min in step (2).

[0037] In some of the embodiments, in step (3), the dispersion is carried out at 20 r / min-40 r / min for 20 min-30 min; preferably, the dispersion is carried out at 25 r / min-35 r / min for 25 min-30 min.

[0038] In some embodiments, in step (4), stirring is performed at 20 r / min-30 r / min for 30 min-40 min; preferably, stirring is performed at 25 r / min-30 r / min for 35 min-40 min.

[0039] 1. In the present invention, 5,7-dihydroxy-4-methylcoumarin and isocyanate silane are reacted to obtain a compound, which can make the silicone conformal coating have a long-lasting fluorescence effect when used to prepare a conformal coating, and the fluorescence can still be effectively detected after heating at 100° C. for 1000 hours. The silicone conformal coating of the present invention has high application value and can be widely used in PCB protection.

[0040] 2. The preparation method of the organosilicon conformal coating of the present invention has good repeatability. DETAILED DESCRIPTION

[0041] In order to facilitate the understanding of the present invention, the present invention will be described more fully below. The present invention can be implemented in many different forms and is not limited to the embodiments described herein. On the contrary, the purpose of providing these embodiments is to make the understanding of the disclosure of the present invention more thorough and comprehensive.

[0042] The experimental methods in the following examples without specifying specific conditions are usually carried out under conventional conditions or conditions recommended by the manufacturers. The various commonly used chemical reagents used in the examples are all commercially available products.

[0043] Unless otherwise defined, all technical and scientific terms used in the present invention have the same meaning as those commonly understood by those skilled in the art to which the present invention belongs. The terms used in the specification of the present invention are only for the purpose of describing specific embodiments and are not intended to limit the present invention. The term "and / or" used in the present invention includes any and all combinations of one or more of the related listed items.

[0044] In addition, as used in the present invention, the term "or" is an inclusive "or" symbol and is equivalent to the term "and / or", unless the context clearly dictates otherwise. The term "based on" is not exclusive and allows for being based on other factors not described, unless the context clearly dictates otherwise. In addition, throughout the specification, the meanings of "a", "an", and "the" include plural referents. The meaning of "in..." includes "in..." and "on...".

[0045] Some embodiments of the present invention relate to a compound obtained by reacting 5,7-dihydroxy-4-methylcoumarin and isocyanate silane; the structural formula of the isocyanate silane is shown in the following formula (I):

[0046]

[0047] Wherein, R is selected from methyl or ethyl.

[0048] The present invention finds that 5,7-dihydroxy-4-methylcoumarin can react with isocyanate silane, and the compound obtained by the reaction can also retain the fluorescence property. When the compound is used to prepare a conformal coating, the silicone conformal coating can have a long-lasting fluorescence effect, and the fluorescence can still be effectively detected after heating at 100°C for 1000 hours.

[0049] Some embodiments of the present invention relate to a method for preparing the above-mentioned compound, comprising the following steps: reacting 5,7-dihydroxy-4-methylcoumarin and isocyanate silane.

[0050] The reaction principle is as follows:

[0051]

[0052] In some of the embodiments, the mass ratio of the 5,7-dihydroxy-4-methylcoumarin to the isocyanate silane is (10-20): (10-15).

[0053] In some preferred embodiments, the mass ratio of the 5,7-dihydroxy-4-methylcoumarin to the isocyanate silane is (13-18): (11-14).

[0054] In some embodiments, the reaction temperature is 80°C to 90°C.

[0055] In some embodiments, the reaction time is 40 min to 60 min.

[0056] In some embodiments, the solvent is at least one of toluene, xylene, dimethylformamide, and dimethylacetamide.

[0057] In some embodiments, the preparation method of the compound comprises the following steps: (1) adding a solvent and 5,7-dihydroxy-4-methylcoumarin to a reaction kettle in sequence, and controlling the reaction temperature to be 80°C-90°C; (2) adding isocyanate silane dropwise to the reaction kettle for reaction; and (3) removing the solvent to obtain the compound.

[0058] In some preferred embodiments, the preparation method of the compound comprises the following steps: (1) adding a solvent and 5,7-dihydroxy-4-methylcoumarin to a reaction kettle in sequence, and controlling the reaction temperature to be 80°C-90°C; (2) controlling the isocyanate silane to be added dropwise within 10min-20min, and continuing the reaction for 40min-60min; (3) removing the solvent to obtain the compound.

[0059] In some of the embodiments, the method for removing the solvent is: raising the temperature in the reactor to 60°C-100°C and reducing the vacuum to below -0.9 MPa, and removing the solvent for 100 min-150 min.

[0060] Some embodiments of the present invention relate to an organic silicone conformal coating, which is prepared from the following raw materials in parts by weight:

[0061]

[0062]

[0063] In some preferred embodiments, the 107 glue is α, ω-dihydroxy polydimethylsiloxane with a viscosity of 100 to 10000 mPa·s at 25±0.5°C; the 201 silicone oil is polydimethylsiloxane with a viscosity of 100 to 1000 mPa·s at 25±0.5°C; the filler is at least one of fumed silica and silicone resin; the cross-linking agent is at least one of methyltrimethoxysilane, methyltriethoxysilane, vinyltrimethoxysilane, and vinyltriethoxysilane; the coupling agent is at least one of aminopropyltrimethoxysilane, aminopropyltriethoxysilane, glycidoxypropyltrimethoxysilane, and glycidoxypropyltriethoxysilane; the catalyst is at least one of dibutyltin diacetate and dibutyltin dilaurate.

[0064] Some embodiments of the present invention relate to a method for preparing the silicone conformal coating as described above, comprising the following steps:

[0065] (1) Add the 107 glue, 201 silicone oil and filler into a planetary disperser, reduce the vacuum degree to below -0.90 MPa, and stir;

[0066] (2) returning to normal pressure, adding the crosslinking agent, dispersing, reducing the vacuum degree to below -0.90 MPa, and continuing to disperse at the original speed;

[0067] (3) returning to normal pressure, adding the coupling agent and the compound, reducing the vacuum to below -0.95 MPa, and dispersing;

[0068] (4) returning to normal pressure, adding the catalyst, reducing the vacuum to below -0.95 MPa, stirring, and obtaining. In some preferred embodiments, the method for preparing the silicone conformal coating comprises the following steps:

[0069] (1) Add the 107 glue, 201 silicone oil and filler into a planetary disperser, reduce the vacuum degree to below -0.90 MPa, and stir at a speed of 20 r / min-30 r / min for 20 min-30 min;

[0070] (2) returning to normal pressure, adding the crosslinking agent, dispersing at 20 r / min-30 r / min for 20 min-30 min, reducing the vacuum degree to below -0.90 MPa, and dispersing at the original speed for 10 min-20 min;

[0071] (3) returning to normal pressure, adding the coupling agent and the compound, reducing the vacuum to below -0.95 MPa, and dispersing at 20 r / min-40 r / min for 20 min-30 min;

[0072] (4) returning to normal pressure, adding the catalyst, reducing the vacuum to below -0.95 MPa, and stirring at 20 r / min-30 r / min for 30 min-40 min to obtain the product.

[0073] The present invention is further described in detail below with reference to specific embodiments.

[0074] In the following examples, the compounds of the present invention are named as self-made fluorescent agents.

[0075] Example 1

[0076] A new type of long-lasting fluorescent silicone conformal paint is prepared by the following method:

[0077] 100 parts by weight of toluene and 13 parts by weight of 5,7-dihydroxy-4-methylcoumarin were added to the reaction kettle in sequence, the reaction temperature was controlled to 80°C, 15 parts by weight of isocyanate propyl trimethoxysilane was added dropwise within 17 minutes, and the reaction was continued for 40 minutes. Finally, the temperature in the kettle was raised to 80°C and the vacuum was reduced to below -0.9 MPa to remove the solvent for 100 minutes to obtain a homemade fluorescent agent.

[0078] Add 75 parts by weight of 107 glue with a viscosity of 100 mPa·s at 25±0.5℃, 50 parts by weight of 201 silicone oil with a viscosity of 350 mPa·s at 25±0.5℃ and 5 parts by weight of silicone resin (methyl MQ resin) to a planetary disperser, reduce the vacuum to below -0.90 MPa, stir at 20 r / min for 30 min to remove bubbles. Restore normal pressure, add 3 parts by weight of methyltrimethoxysilane, adjust the stirring rate to 20 r / min and disperse for 20 min, then reduce the vacuum to below -0.90 MPa, maintain the original stirring rate and disperse for 20 min. After restoring normal pressure, add 1.5 parts by weight of aminopropyltrimethoxysilane and 0.8 parts by weight of homemade fluorescent agent, reduce the vacuum to below -0.95 MPa, adjust the stirring rate to 20 r / min and disperse for 30 min. The pressure was restored to normal and 1 part by weight of dibutyltin diacetate was added, the vacuum was reduced to below -0.95 MPa, the stirring rate was adjusted to 30 r / min and the mixture was stirred for 35 min to obtain a finished conformal coating.

[0079] Example 2

[0080] A new type of long-lasting fluorescent silicone conformal paint is prepared by the following method:

[0081] 100 parts by weight of xylene and 15 parts by weight of 5,7-di-hydroxy-4-methylcoumarin were added to the reaction kettle in sequence, the reaction temperature was controlled at 90°C, 13 parts by weight of isocyanate propyl triethoxysilane was added dropwise within 15 minutes, and the reaction was continued for 60 minutes. Finally, the temperature in the kettle was raised to 70°C and the vacuum was reduced to below -0.9 MPa for 150 minutes to remove the solvent, and the homemade fluorescent agent was obtained.

[0082] Add 70 parts by weight of 107 glue with a viscosity of 10000 mPa·s at 25±0.5℃, 50 parts by weight of 201 silicone oil with a viscosity of 100 mPa·s at 25±0.5℃ and 10 parts by weight of white carbon black fat to a planetary disperser, reduce the vacuum to below -0.90 MPa, stir at 30 r / min for 20 minutes to remove bubbles. Restore normal pressure, add 4 parts by weight of methyltriethoxysilane, adjust the stirring rate to 25 r / min and disperse for 25 minutes, then reduce the vacuum to below -0.90 MPa, maintain the original stirring rate and disperse for 10 minutes. After restoring normal pressure, add 1 part by weight of aminopropyltriethoxysilane and 0.7 parts by weight of homemade fluorescent agent, reduce the vacuum to below -0.95 MPa, adjust the stirring rate to 40 r / min and disperse for 20 minutes. The pressure was restored to normal and 0.6 parts by weight of dibutyltin dilaurate was added. The vacuum was reduced to below -0.95 MPa. The stirring rate was adjusted to 25 r / min and the mixture was stirred for 35 min to obtain a finished conformal coating.

[0083] Example 3

[0084] A new type of long-lasting fluorescent silicone conformal paint is prepared by the following method:

[0085] 100 parts by weight of dimethylformamide and 20 parts by weight of 5,7-dihydroxy-4-methylcoumarin were added to the reaction kettle in sequence, the reaction temperature was controlled at 85°C, 12 parts by weight of isocyanate propyl triethoxysilane was added dropwise within 20 minutes, and the reaction was continued for 50 minutes. Finally, the temperature in the kettle was raised to 100°C and the vacuum was reduced to below -0.9 MPa to remove the solvent for 125 minutes to obtain a self-made fluorescent agent.

[0086] Add 80 parts by weight of 107 glue with a viscosity of 1500 mPa·s at 25±0.5℃ to a planetary disperser; add 7 parts by weight of silicone resin (methyl MQ resin) and reduce the vacuum to below -0.90MPa and stir at 25r / min for 25min to remove bubbles. After returning to normal pressure, add 5 parts by weight of vinyltrimethoxysilane, adjust the stirring rate to 30r / min and disperse for 20min, then reduce the vacuum to below -0.90MPa and maintain the original stirring rate to disperse for 15min. After returning to normal pressure, add 2 parts by weight of glycidoxypropyltrimethoxysilane and 0.5 parts by weight of homemade fluorescent agent, reduce the vacuum to below -0.95MPa, adjust the stirring rate to 30r / min and disperse for 25min. The pressure was restored to normal, and 0.75 parts by weight of dibutyltin diacetate and 0.1 parts by weight of dibutyltin dilaurate were added. The vacuum was reduced to below -0.95 MPa, and the stirring rate was adjusted to 20 r / min and stirred for 40 minutes to obtain a finished conformal coating.

[0087] Example 4

[0088] A new type of long-lasting fluorescent silicone conformal paint is prepared by the following method:

[0089] 100 parts by weight of dimethylacetamide and 10 parts by weight of 5,7-dihydroxy-4-methylcoumarin were added to the reaction kettle in sequence, the reaction temperature was controlled to 88°C, 10 parts by weight of isocyanate propyltrimethoxysilane was added dropwise within 10 minutes, and the reaction was continued for 45 minutes. Finally, the temperature in the kettle was raised to 60°C and the vacuum was reduced to below -0.9 MPa to remove the solvent for 130 minutes to obtain the homemade fluorescent agent.

[0090] Add 60 parts by weight of 107 glue with a viscosity of 5000 mPa·s at 25±0.5℃, 25 parts by weight of 201 silicone oil with a viscosity of 1000 mPa·s at 25±0.5℃ and 6 parts by weight of white carbon black to a planetary disperser, reduce the vacuum to below -0.90 MPa, stir at 30 r / min for 30 min to remove bubbles. Restore normal pressure, add 3 parts by weight of vinyl triethoxysilane, adjust the stirring rate to 20 r / min and disperse for 30 min, then reduce the vacuum to below -0.90 MPa, maintain the original stirring rate and disperse for 17 min. After restoring normal pressure, add 0.5 parts by weight of glycidoxypropyl triethoxysilane and 1.0 parts by weight of homemade fluorescent agent, reduce the vacuum to below -0.95 MPa, adjust the stirring rate to 40 r / min and disperse for 30 min. The pressure was restored to normal and 0.5 parts by weight of dibutyltin dilaurate was added. The vacuum was reduced to below -0.95 MPa. The stirring rate was adjusted to 30 r / min and the mixture was stirred for 30 min to obtain a finished conformal coating.

[0091] Example 5

[0092] A new type of long-lasting fluorescent silicone conformal paint is prepared by the following method:

[0093] 100 parts by weight of toluene and 18 parts by weight of 5,7-dihydroxy-4-methylcoumarin were added to the reaction kettle in sequence, the reaction temperature was controlled to 80°C, and 11 parts by weight of isocyanate propyl trimethoxysilane were added dropwise within 17 minutes, and the reaction was continued for 40 minutes. Finally, the temperature in the kettle was raised to 80°C and the vacuum was reduced to below -0.9 MPa to remove the solvent for 100 minutes to obtain a homemade fluorescent agent.

[0094] Add 65 parts by weight of 107 glue with a viscosity of 100 mPa·s at 25±0.5℃, 5 parts by weight of 201 silicone oil with a viscosity of 350 mPa·s at 25±0.5℃ and 8 parts by weight of silicone resin (methyl MQ resin) to a planetary disperser, reduce the vacuum to below -0.90 MPa, stir at 20 r / min for 30 min to remove bubbles. Restore normal pressure, add 4.5 parts by weight of methyltrimethoxysilane, adjust the stirring rate to 20 r / min and disperse for 20 min, then reduce the vacuum to below -0.90 MPa, maintain the original stirring rate and disperse for 20 min. After restoring normal pressure, add 1.5 parts by weight of aminopropyltrimethoxysilane and 0.9 parts by weight of homemade fluorescent agent, reduce the vacuum to below -0.95 MPa, adjust the stirring rate to 20 r / min and disperse for 30 min. The pressure was restored to normal and 1 part by weight of dibutyltin diacetate was added, the vacuum was reduced to below -0.95 MPa, the stirring rate was adjusted to 30 r / min and the mixture was stirred for 35 min to obtain a finished conformal coating.

[0095] Comparative Example 1

[0096] The organic silicon conformal coating of this comparative example comprises the following steps (based on Example 1, 5,7-dihydroxy-4-methylcoumarin and isocyanatepropyltrimethoxysilane are directly mixed as a fluorescent agent, and the two are not reacted in the reactor first):

[0097] 13 parts by weight of 5,7-dihydroxy-4-methylcoumarin and 15 parts by weight of isocyanatepropyltrimethoxysilane were uniformly mixed to obtain a self-made fluorescent agent.

[0098] Add 75 parts by weight of 107 glue with a viscosity of 100 mPa·s at 25±0.5℃, 50 parts by weight of 201 silicone oil with a viscosity of 350 mPa·s at 25±0.5℃ and 5 parts by weight of silicone resin (methyl MQ resin) to a planetary disperser, reduce the vacuum to below -0.90 MPa, stir at 20 r / min for 30 min to remove bubbles. Restore normal pressure, add 3 parts by weight of methyltrimethoxysilane, adjust the stirring rate to 20 r / min and disperse for 20 min, then reduce the vacuum to below -0.90 MPa, maintain the original stirring rate and disperse for 20 min. After restoring normal pressure, add 1.5 parts by weight of aminopropyltrimethoxysilane and 0.8 parts by weight of homemade fluorescent agent, reduce the vacuum to below -0.95 MPa, adjust the stirring rate to 20 r / min and disperse for 30 min. The pressure was restored to normal and 1 part by weight of dibutyltin diacetate was added, the vacuum was reduced to below -0.95 MPa, the stirring rate was adjusted to 30 r / min and the mixture was stirred for 35 min to obtain a finished conformal coating.

[0099] Comparative Example 2

[0100] The organic silicon conformal coating of this comparative example comprises the following steps (based on Example 1, 5,7-dihydroxy-4-methylcoumarin is directly used as a fluorescent agent):

[0101] Add 75 parts by weight of 107 glue with a viscosity of 100 mPa·s at 25±0.5℃, 50 parts by weight of 201 silicone oil with a viscosity of 350 mPa·s at 25±0.5℃ and 5 parts by weight of silicone resin (methyl MQ resin) to a planetary disperser, reduce the vacuum to below -0.90 MPa, stir at 20 r / min for 30 minutes to remove bubbles. Restore normal pressure, add 3 parts by weight of methyltrimethoxysilane, adjust the stirring rate to 20 r / min, disperse for 20 minutes, reduce the vacuum to below -0.90 MPa, maintain the original stirring rate and disperse for 20 minutes. After restoring normal pressure, add 1.5 parts by weight of aminopropyltrimethoxysilane and 0.8 parts by weight of 5,7-dihydroxy-4-methylcoumarin, reduce the vacuum to below -0.95 MPa, adjust the stirring rate to 20 r / min and disperse for 30 minutes. The pressure was restored to normal and 1 part by weight of dibutyltin diacetate was added, the vacuum was reduced to below -0.95 MPa, the stirring rate was adjusted to 30 r / min and the mixture was stirred for 35 min to obtain a finished conformal coating.

[0102] The fluorescent silicone conformal coatings prepared in the above examples and comparative examples were cured at 23±3°C and 50±5% RH for 14 days as test objects. In order to detect the fluorescence retention ability of each group of silicone conformal coatings after long-term heat resistance, each group of coatings was heated at 100°C for 1000h, and then directly excited with ultraviolet light and observed with the naked eye for fluorescence.

[0103] At the same time, the following properties of the fluorescent organosilicon conformal coatings prepared in the above examples and comparative examples were tested:

[0104] 1. Surface drying time: Tested according to Method B of Surface Drying Time Determination in GB 1728-1979, i.e., finger touch method.

[0105] 2. Paint film adhesion: Determined according to the cross-cut test method of paint film in GB / T 9286-1998.

[0106] 3. Volume resistivity: Determined according to GB / T 1410-2006 solid insulating material volume resistivity test method.

[0107] The test results are filled in Table 1:

[0108] Table 1

[0109]

[0110] As shown in Table 1, after the coating film obtained by curing the silicone conformal coating of the present invention is heated at 100°C for 1000 hours, fluorescence can still be observed when excited by ultraviolet light, and the fluorescence retention ability after long-term heat resistance is good. 5,7-dihydroxy-4-methylcoumarin and isocyanate silane can react to prepare a reactive fluorescent agent, which retains the fluorescent property and can be connected to the silicone conformal coating in the form of a chemical bond, thereby greatly improving the long-term fluorescence property of the silicone conformal coating.

[0111] Compared with Example 1, in the preparation process of the silicone conformal coating in Comparative Example 1, 5,7-dihydroxy-4-methylcoumarin and isocyanate silane are not first subjected to a chemical reaction, but are added as raw materials for the preparation of the silicone conformal coating respectively. After the coating film obtained by curing the prepared silicone conformal coating is heated at 100° C. for 1000 hours, no fluorescence can be observed when excited by ultraviolet light.

[0112] Compared with Example 1, in Comparative Example 2, 5,7-dihydroxy-4-methylcoumarin is directly used as a fluorescent agent during the preparation of the silicone conformal coating. After the coating film obtained by curing the silicone conformal coating is heated at 100° C. for 1000 hours, no fluorescence can be observed when excited by ultraviolet light.

[0113] The above-mentioned embodiments only express several implementation methods of the present invention, and the description thereof is relatively specific and detailed, but it cannot be understood as limiting the scope of the invention patent. It should be pointed out that for ordinary technicians in this field, several modifications and improvements can be made without departing from the concept of the present invention, which all belong to the protection scope of the present invention. Therefore, the protection scope of the patent of the present invention shall be based on the attached claims.

Claims

1. A compound, characterized in that The compound is prepared by reacting 5,7-dihydroxy-4-methylcoumarin and isocyanate silane; the structural formula of the isocyanate silane is shown in the following formula (I): Wherein, R is selected from methyl or ethyl.

2. The compound according to claim 1, characterized in that The mass ratio of the 5,7-dihydroxy-4-methylcoumarin to the isocyanate silane is (10-20): (10-15); and / or, The reaction temperature is 80°C to 90°C; and / or, The reaction time is 40 min to 60 min.

3. The method for preparing the compound according to claim 1 or 2, characterized in that: The following steps are involved: 5,7-dihydroxy-4-methylcoumarin and isocyanate silane are reacted.

4. The preparation method according to claim 3, characterized in that: The mass ratio of the 5,7-dihydroxy-4-methylcoumarin to the isocyanate silane is (10-20): (10-15); and / or, The reaction temperature is 80°C to 90°C; and / or, The reaction time is 40 min to 60 min.

5. The preparation method according to claim 3 or 4, characterized in that: The solvent of the reaction is at least one of toluene, xylene, dimethylformamide and dimethylacetamide.

6. Use of the compound as claimed in claim 1 or 2 as a fluorescent agent in the preparation of conformal coatings.

7. An organic silicon conformal coating, characterized in that: It is prepared from the following raw materials in parts by weight:

8. The silicone conformal coating according to claim 7, characterized in that: It is prepared from the following raw materials in parts by weight:

9. The organic silicon conformal coating according to claim 7 or 8, characterized in that: The 107 glue is α,ω-dihydroxy polydimethylsiloxane with a viscosity of 100 to 10000 mPa·s at 25±0.5°C; and / or, The 201 silicone oil is polydimethylsiloxane with a viscosity of 100 to 1000 mPa·s at 25±0.5°C; and / or, The filler is at least one of fumed silica and silicone resin; and / or, The crosslinking agent is at least one of methyltrimethoxysilane, methyltriethoxysilane, vinyltrimethoxysilane and vinyltriethoxysilane; and / or, The coupling agent is at least one of aminopropyltrimethoxysilane, aminopropyltriethoxysilane, glycidoxypropyltrimethoxysilane and glycidoxypropyltriethoxysilane; and / or, The catalyst is at least one of dibutyltin diacetate and dibutyltin dilaurate.

10. The method for preparing a silicone conformal coating according to any one of claims 7 to 9, characterized in that: The following steps are involved: (1) Add the 107 glue, 201 silicone oil and filler into a planetary disperser, reduce the vacuum degree to below -0.90 MPa, and stir; (2) returning to normal pressure, adding the crosslinking agent, dispersing, reducing the vacuum degree to below -0.90 MPa, and continuing to disperse at the original speed; (3) returning to normal pressure, adding the coupling agent and the compound, reducing the vacuum to below -0.95 MPa, and dispersing; (4) returning to normal pressure, adding the catalyst, reducing the vacuum to below -0.95 MPa, stirring, and obtaining the product.

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