A composite thermal conductive coating for electronic products and preparation method thereof

Abstract

The present invention belongs to the technical field of special coatings. The present invention provides a composite thermal conductive coating for electronic products and a preparation method thereof, wherein a composite thermal conductive coating for electronic products includes, by weight: 40-60 parts of saturated polyester resin, 20-30 parts of epoxy resin, 30-50 parts of reactive diluent, 20-40 parts of thermal conductive filler, 10-20 parts of silicon micropowder, 10-20 parts of molybdenum disulfide, 1-5 parts of coupling agent, 0.5-2 parts of cationic initiator, 0.5-2 parts of antioxidant, 0.1-1 parts of leveling agent, 1-5 parts of pigment, and 0.5-2 parts of dispersant. The composite thermal conductive coating provided by the present invention has high thermal conductivity, and through the composite thermal conductive filler and reinforcing raw materials, under their synergistic effect, the coating has excellent thermal conductivity and mechanical properties.

Description

Technical Field

[0001] The invention belongs to the technical field of special coatings, and in particular relates to a composite thermal conductive coating for electronic products and a preparation method thereof. Background Art

[0002] The finishing paints used in computers, communication products and consumer electronics (especially household appliances) are widely referred to as 3C paints. These products have extremely high requirements in terms of protection and appearance. For these products, the refinement of the external surface coating process is closely related to the paint selected, and the coating material has gradually developed into one of the key factors to measure the level of product level.

[0003] For computers, communication products and consumer electronics, heat dissipation is a very important problem that needs to be solved. The heat dissipation effect of the product will directly affect the performance and service life of the product. In addition to using larger heat sinks and more advanced heat dissipation technology, the use of coatings with heat dissipation effects in product components and shells can also improve the heat dissipation efficiency of the product. In recent years, graphene, which has excellent thermal conductivity, has gradually been used in thermal conductive coatings, but its cost is high, processing is difficult, and there may be compatibility issues in certain application scenarios. Therefore, it is particularly important to develop a thermal conductive coating with good thermal conductivity and wide application scenarios. Summary of the invention

[0004] In view of the deficiencies in the prior art, the present invention provides a composite thermal conductive coating for electronic products and a preparation method thereof.

[0005] The invention provides a composite thermal conductive coating for electronic products, which comprises, by weight, 40-60 parts of saturated polyester resin, 20-30 parts of epoxy resin, 30-50 parts of active diluent, 20-40 parts of thermal conductive filler, 10-20 parts of silicon micropowder, 10-20 parts of molybdenum disulfide, 1-5 parts of coupling agent, 0.5-2 parts of cationic initiator, 0.5-2 parts of antioxidant, 0.1-1 parts of leveling agent, 1-5 parts of pigment and 0.5-2 parts of dispersant.

[0006] Furthermore, in parts by weight, it includes: 45-55 parts of saturated polyester resin, 23-28 parts of epoxy resin, 35-45 parts of active diluent, 25-35 parts of thermal conductive filler, 10-18 parts of silicon micropowder, 12-18 parts of molybdenum disulfide, 2-5 parts of coupling agent, 1-2 parts of cationic initiator, 1-2 parts of antioxidant, 0.1-1 parts of leveling agent, 1-5 parts of pigment, and 1-2 parts of dispersant.

[0007] Furthermore, in parts by weight, it includes: 45-50 parts of saturated polyester resin, 23-25 ​​parts of epoxy resin, 35-40 parts of active diluent, 25-30 parts of thermal conductive filler, 10-15 parts of silicon micropowder, 12-15 parts of molybdenum disulfide, 2-5 parts of coupling agent, 1-2 parts of cationic initiator, 1-2 parts of antioxidant, 0.1-1 parts of leveling agent, 2-5 parts of pigment, and 1-2 parts of dispersant.

[0008] Furthermore, the thermal conductive filler comprises 5-10 parts of aluminum nitride and 15-30 parts of modified polyvinylidene fluoride, in parts by weight, wherein the modified polyvinylidene fluoride is modified by aluminum oxide and boron nitride, and the preparation of the modified polyvinylidene fluoride comprises the following steps:

[0009] Step S11: taking 30 wt % of aluminum oxide, 10-20 wt % of boron nitride and 50-60 wt % of polyvinylidene fluoride by weight percentage, dissolving the polyvinylidene fluoride in N,N-dimethylformamide to obtain a mixed solution;

[0010] Step S12: adding aluminum oxide and boron nitride to the mixed solution and dispersing for 15-30 minutes;

[0011] Step S13: pouring the dispersed mixed solution into deionized water to form a precipitate; filtering the precipitate, and vacuum drying it at 70° C. for 24 hours;

[0012] Step S14: The obtained composite is hot-pressed at 200° C. and 10 MPa for 2 min to obtain modified polyvinylidene fluoride.

[0013] Furthermore, the boron nitride is hexagonal boron nitride nanosheets.

[0014] Furthermore, the coupling agent is a silane coupling agent or a titanate coupling agent.

[0015] Furthermore, the cationic initiator is diphenyl-(4-phenylthio)phenylsulfonium hexafluoroantimonate and / or diphenyl-(4-phenylthio)phenylsulfonium hexafluorophosphate.

[0016] Furthermore, the reactive diluent is propylene glycol diacrylate or tripropylene glycol diacrylate.

[0017] Furthermore, based on parts by weight, 0.1-0.5 parts of a defoaming agent are also included.

[0018] The present invention also provides a method for preparing the composite thermal conductive coating for electronic products, comprising the following steps:

[0019] Step S21: weighing a saturated polyester resin, an epoxy resin and a reactive diluent, adding them into a reaction kettle and stirring them evenly to form a resin mixture;

[0020] Step S22: adding a thermal conductive filler, silicon powder, molybdenum disulfide and a dispersant to the resin mixture in sequence, and stirring the mixture to uniformly disperse the thermal conductive filler; then adding a coupling agent, and continuing stirring the reaction;

[0021] Step S23: continue to add the cationic initiator to the uniformly mixed coating, and continue to stir until the cationic initiator is completely dissolved;

[0022] Step S24: finally, adding an antioxidant, a leveling agent and a pigment, stirring evenly and then stopping the stirring, filtering the mixed coating to remove impurities and incompletely dispersed particles;

[0023] Step S25: adding a defoamer to the filtered coating and stirring evenly to obtain a composite thermal conductive coating.

[0024] The composite thermal conductive coating for electronic products provided by the present invention has at least the following beneficial effects:

[0025] 1. High thermal conductivity. Through the synergistic effect of composite thermal conductive fillers and reinforcing raw materials, the coating has excellent thermal conductivity;

[0026] 2. Good insulation properties, meeting the safety requirements of electronic components.

[0027] ‌3. Moderate cost‌: The cost of raw materials for coatings is low, which is more suitable for large-scale industrial production.

[0028] ‌4. Environmental protection and energy saving‌: The paint does not contain volatile organic solvents, and the UV curing process does not require high-temperature baking, which is energy-saving and environmentally friendly. DETAILED DESCRIPTION

[0029] The technical solution of the present invention is further described in detail below in conjunction with specific embodiments so that those skilled in the art can better understand the present invention and implement it, but the embodiments are not intended to limit the present invention.

[0030] With the development of the "5G popularization craze", 3C coatings dedicated to electronic devices have gradually risen, but the development of 5G has also brought new challenges to the coatings industry. On the one hand, the components of 5G devices are denser and more integrated, which also brings higher heat. Heat dissipation has become an issue that must be considered for coatings; on the other hand, 5G signals have relatively weak penetration, and metal bodies or highly conductive coatings will weaken signal strength. This has led to the use of glass or plastic materials for the bodies of most 5G devices, which has brought challenges to the adhesion of coatings.

[0031] An embodiment of the present invention provides a composite thermally conductive coating for electronic products, which includes, by weight: 40-60 parts of saturated polyester resin, 20-30 parts of epoxy resin, 30-50 parts of active diluent, 20-40 parts of thermally conductive filler, 10-20 parts of silicon micropowder, 10-20 parts of molybdenum disulfide, 1-5 parts of coupling agent, 0.5-2 parts of cationic initiator, 0.5-2 parts of antioxidant, 0.1-1 parts of leveling agent, 1-5 parts of pigment, and 0.5-2 parts of dispersant.

[0032] The composite thermal conductive coating provided in this embodiment has excellent thermal conductivity and comprehensive performance through the synergistic effect of composite thermal conductive fillers and reinforcing raw materials. Saturated polyester resin and epoxy resin as the base materials of the coating can provide good film-forming properties and adhesion; the active diluent is used to adjust the viscosity of the coating and can promote the curing reaction of the coating; the polyvinylidene fluoride modified by aluminum oxide / boron nitride has good chemical stability and mechanical strength, and also forms a thermal conductive network in the polyvinylidene fluoride, significantly improving the thermal conductivity of the polyvinylidene fluoride, thereby improving the thermal conductivity of the coating; and aluminum nitride and modified polyvinylidene fluoride produce a synergistic effect to further enhance the thermal conductivity effect; molybdenum disulfide can provide excellent thermal conductivity while also providing good wear resistance and corrosion resistance; silicon micropowder can enhance the mechanical strength and wear resistance of the coating; cationic initiator is mainly used to promote ultraviolet light curing reaction.

[0033] Furthermore, in parts by weight, it includes: 45-55 parts of saturated polyester resin, 23-28 parts of epoxy resin, 35-45 parts of active diluent, 25-35 parts of thermal conductive filler, 10-18 parts of silicon micropowder, 12-18 parts of molybdenum disulfide, 2-5 parts of coupling agent, 1-2 parts of cationic initiator, 1-2 parts of antioxidant, 0.1-1 parts of leveling agent, 1-5 parts of pigment, and 1-2 parts of dispersant.

[0034] Furthermore, in parts by weight, it includes: 45-50 parts of saturated polyester resin, 23-25 ​​parts of epoxy resin, 35-40 parts of active diluent, 25-30 parts of thermal conductive filler, 10-15 parts of silicon micropowder, 12-15 parts of molybdenum disulfide, 2-5 parts of coupling agent, 1-2 parts of cationic initiator, 1-2 parts of antioxidant, 0.1-1 parts of leveling agent, 2-5 parts of pigment, and 1-2 parts of dispersant.

[0035] Furthermore, the thermal conductive filler comprises 5-10 parts of aluminum nitride and 15-30 parts of modified polyvinylidene fluoride, in parts by weight, wherein the modified polyvinylidene fluoride is modified by aluminum oxide and boron nitride. The preparation of the modified polyvinylidene fluoride comprises the following steps:

[0036] Step S11: taking 30 wt % of aluminum oxide, 10-20 wt % of boron nitride and 50-60 wt % of polyvinylidene fluoride by weight percentage, dissolving the polyvinylidene fluoride in N,N-dimethylformamide to obtain a mixed solution;

[0037] Step S12: adding aluminum oxide and boron nitride to the mixed solution and dispersing for 15-30 minutes;

[0038] Step S13: pouring the dispersed mixed solution into deionized water to form a precipitate; filtering the precipitate, and vacuum drying it at 70° C. for 24 hours;

[0039] Step S14: The obtained composite is hot-pressed at 200° C. and 10 MPa for 2 min to obtain modified polyvinylidene fluoride.

[0040] Furthermore, the boron nitride is hexagonal boron nitride nanosheets.

[0041] Furthermore, the coupling agent is a silane coupling agent or a titanate coupling agent.

[0042] Further, the cationic initiator is diphenyl-(4-phenylthio)phenylsulfonium hexafluoroantimonate and / or diphenyl-(4-phenylthio)phenylsulfonium hexafluorophosphate.

[0043] Furthermore, the reactive diluent is propylene glycol diacrylate or tripropylene glycol diacrylate.

[0044] Furthermore, based on parts by weight, 0.1-0.5 parts of a defoaming agent are also included.

[0045] The present invention also provides a method for preparing the composite thermal conductive coating for electronic products, comprising the following steps:

[0046] Step S21: weighing a saturated polyester resin, an epoxy resin and a reactive diluent, adding them into a reaction kettle and stirring them evenly to form a resin mixture;

[0047] Step S22: adding a thermal conductive filler, silicon powder, molybdenum disulfide and a dispersant to the resin mixture in sequence, and stirring the mixture to uniformly disperse the thermal conductive filler; then adding a coupling agent, and continuing stirring the reaction;

[0048] Step S23: continue to add the cationic initiator to the uniformly mixed coating, and continue to stir until the cationic initiator is completely dissolved;

[0049] Step S24: finally, adding an antioxidant, a leveling agent and a pigment, stirring evenly and then stopping the stirring, filtering the mixed coating to remove impurities and incompletely dispersed particles;

[0050] Step S25: adding a defoamer to the filtered coating and stirring evenly to obtain a composite thermal conductive coating.

[0051] To better illustrate the solutions of the present invention, the following are specific embodiments.

[0052] Example 1

[0053] The formula of the composite thermal conductive coating is: in parts by weight: 40 parts of saturated polyester resin, 20 parts of epoxy resin, 30 parts of dipropylene glycol diacrylate, 5 parts of aluminum nitride, 15 parts of modified polyvinylidene fluoride, 10 parts of silicon powder, 10 parts of molybdenum disulfide, 2 parts of silane coupling agent, 0.5 parts of diphenyl-(4-phenylsulfide)phenylsulfonium hexafluoroantimonate, 0.5 parts of antioxidant, 0.1 parts of leveling agent, 1 part of pigment, 0.5 parts of dispersant, and 0.1 parts of defoaming agent.

[0054] Preparation method:

[0055] (1) Preparation of modified polyvinylidene fluoride:

[0056] Step S11: taking 30 wt % of aluminum oxide, 20 wt % of boron nitride and 50 wt % of polyvinylidene fluoride by weight percentage, dissolving the polyvinylidene fluoride in N,N-dimethylformamide to obtain a mixed solution;

[0057] Step S12: adding aluminum oxide and boron nitride to the mixed solution and dispersing for 30 minutes;

[0058] Step S13: pouring the dispersed mixed solution into deionized water to form a precipitate; filtering the precipitate, and vacuum drying it at 70° C. for 24 hours;

[0059] Step S14: The obtained composite is hot-pressed at 200° C. and 10 MPa for 2 min to obtain modified polyvinylidene fluoride.

[0060] (2) Preparation of composite thermal conductive coating:

[0061] Step S21: weighing a saturated polyester resin, an epoxy resin and a reactive diluent, adding them into a reaction kettle and stirring them evenly to form a resin mixture;

[0062] Step S22: adding a thermal conductive filler, silicon powder, molybdenum disulfide and a dispersant to the resin mixture in sequence, and stirring the mixture to uniformly disperse the thermal conductive filler; then adding a coupling agent, and continuing stirring the reaction;

[0063] Step S23: continue to add the cationic initiator to the uniformly mixed coating, and continue to stir until the cationic initiator is completely dissolved;

[0064] Step S24: finally, adding an antioxidant, a leveling agent and a pigment, stirring evenly and then stopping the stirring, filtering the mixed coating to remove impurities and incompletely dispersed particles;

[0065] Step S25: adding a defoamer to the filtered coating and stirring evenly to obtain a composite thermal conductive coating.

[0066] Example 2

[0067] The formula of the composite thermal conductive coating is: in parts by weight: 50 parts of saturated polyester resin, 25 parts of epoxy resin, 40 parts of dipropylene glycol diacrylate, 8 parts of aluminum nitride, 22 parts of modified polyvinylidene fluoride, 15 parts of silicon micropowder, 15 parts of molybdenum disulfide, 3 parts of silane coupling agent, 0.8 parts of diphenyl-(4-phenylsulfide)phenylsulfonium hexafluoroantimonate, 0.8 parts of antioxidant, 0.3 parts of leveling agent, 2 parts of pigment, 0.8 parts of dispersant, and 0.2 parts of defoaming agent.

[0068] Preparation method:

[0069] (1) Preparation of modified polyvinylidene fluoride:

[0070] Step S11: taking 30 wt % of aluminum oxide, 20 wt % of boron nitride and 50 wt % of polyvinylidene fluoride by weight percentage, dissolving the polyvinylidene fluoride in N,N-dimethylformamide to obtain a mixed solution;

[0071] Step S12: adding aluminum oxide and boron nitride to the mixed solution and dispersing for 30 minutes;

[0072] Step S13: pouring the dispersed mixed solution into deionized water to form a precipitate; filtering the precipitate, and vacuum drying it at 70° C. for 24 hours;

[0073] Step S14: The obtained composite is hot-pressed at 200° C. and 10 MPa for 2 min to obtain modified polyvinylidene fluoride.

[0074] (2) Preparation of composite thermal conductive coating:

[0075] Step S21: weighing a saturated polyester resin, an epoxy resin and a reactive diluent, adding them into a reaction kettle and stirring them evenly to form a resin mixture;

[0076] Step S22: adding a thermal conductive filler, silicon powder, molybdenum disulfide and a dispersant to the resin mixture in sequence, and stirring the mixture to uniformly disperse the thermal conductive filler; then adding a coupling agent, and continuing stirring the reaction;

[0077] Step S23: continue to add the cationic initiator to the uniformly mixed coating, and continue to stir until the cationic initiator is completely dissolved;

[0078] Step S24: finally, adding an antioxidant, a leveling agent and a pigment, stirring evenly and then stopping the stirring, filtering the mixed coating to remove impurities and incompletely dispersed particles;

[0079] Step S25: adding a defoamer to the filtered coating and stirring evenly to obtain a composite thermal conductive coating.

[0080] Example 3

[0081] The formula of the composite thermal conductive coating is: in parts by weight: 60 parts of saturated polyester resin, 30 parts of epoxy resin, 50 parts of dipropylene glycol diacrylate, 10 parts of aluminum nitride, 30 parts of modified polyvinylidene fluoride, 20 parts of silicon powder, 20 parts of molybdenum disulfide, 4 parts of silane coupling agent, 1 part of diphenyl-(4-phenylsulfide)phenylsulfonium hexafluoroantimonate, 1 part of antioxidant, 0.5 parts of leveling agent, 3 parts of pigment, 1 part of dispersant, and 0.3 parts of defoaming agent.

[0082] Preparation method:

[0083] (1) Preparation of modified polyvinylidene fluoride:

[0084] Step S11: taking 30 wt % of aluminum oxide, 20 wt % of boron nitride and 50 wt % of polyvinylidene fluoride by weight percentage, dissolving the polyvinylidene fluoride in N,N-dimethylformamide to obtain a mixed solution;

[0085] Step S12: adding aluminum oxide and boron nitride to the mixed solution and dispersing for 30 minutes;

[0086] Step S13: pouring the dispersed mixed solution into deionized water to form a precipitate; filtering the precipitate, and vacuum drying it at 70° C. for 24 hours;

[0087] Step S14: The obtained composite is hot-pressed at 200° C. and 10 MPa for 2 min to obtain modified polyvinylidene fluoride.

[0088] (2) Preparation of composite thermal conductive coating:

[0089] Step S21: weighing a saturated polyester resin, an epoxy resin and a reactive diluent, adding them into a reaction kettle and stirring them evenly to form a resin mixture;

[0090] Step S22: adding a thermal conductive filler, silicon powder, molybdenum disulfide and a dispersant to the resin mixture in sequence, and stirring the mixture to uniformly disperse the thermal conductive filler; then adding a coupling agent, and continuing stirring the reaction;

[0091] Step S23: continue to add the cationic initiator to the uniformly mixed coating, and continue to stir until the cationic initiator is completely dissolved;

[0092] Step S24: finally, adding an antioxidant, a leveling agent and a pigment, stirring evenly and then stopping the stirring, filtering the mixed coating to remove impurities and incompletely dispersed particles;

[0093] Step S25: adding a defoamer to the filtered coating and stirring evenly to obtain a composite thermal conductive coating.

[0094] Example 4

[0095] The formula of the composite thermal conductive coating is the same as that of Example 1 except for the modified polyvinylidene fluoride.

[0096] Preparation method:

[0097] (1) Preparation of modified polyvinylidene fluoride:

[0098] Step S11: taking 30 wt % of aluminum oxide, 15 wt % of boron nitride and 55 wt % of polyvinylidene fluoride by weight percentage, dissolving the polyvinylidene fluoride in N,N-dimethylformamide to obtain a mixed solution;

[0099] Step S12: adding aluminum oxide and boron nitride to the mixed solution and dispersing for 30 minutes;

[0100] Step S13: pouring the dispersed mixed solution into deionized water to form a precipitate; filtering the precipitate, and vacuum drying it at 70° C. for 24 hours;

[0101] Step S14: The obtained composite is hot-pressed at 200° C. and 10 MPa for 2 min to obtain modified polyvinylidene fluoride.

[0102] (2) Preparation of composite thermal conductive coating:

[0103] Step S21: weighing a saturated polyester resin, an epoxy resin and a reactive diluent, adding them into a reaction kettle and stirring them evenly to form a resin mixture;

[0104] Step S22: adding a thermal conductive filler, silicon powder, molybdenum disulfide and a dispersant to the resin mixture in sequence, and stirring the mixture to uniformly disperse the thermal conductive filler; then adding a coupling agent, and continuing stirring the reaction;

[0105] Step S23: continue to add the cationic initiator to the uniformly mixed coating, and continue to stir until the cationic initiator is completely dissolved;

[0106] Step S24: finally, adding an antioxidant, a leveling agent and a pigment, stirring evenly and then stopping the stirring, filtering the mixed coating to remove impurities and incompletely dispersed particles;

[0107] Step S25: adding a defoamer to the filtered coating and stirring evenly to obtain a composite thermal conductive coating.

[0108] Example 5

[0109] The formula of the composite thermal conductive coating is the same as that of Example 1 except for the modified polyvinylidene fluoride.

[0110] Preparation method:

[0111] (1) Preparation of modified polyvinylidene fluoride:

[0112] Step S11: taking 30 wt % of aluminum oxide, 10 wt % of boron nitride and 60 wt % of polyvinylidene fluoride by weight percentage, dissolving the polyvinylidene fluoride in N,N-dimethylformamide to obtain a mixed solution;

[0113] Step S12: adding aluminum oxide and boron nitride to the mixed solution and dispersing for 30 minutes;

[0114] Step S13: pouring the dispersed mixed solution into deionized water to form a precipitate; filtering the precipitate, and vacuum drying it at 70° C. for 24 hours;

[0115] Step S14: The obtained composite is hot-pressed at 200° C. and 10 MPa for 2 min to obtain modified polyvinylidene fluoride.

[0116] (2) Preparation of composite thermal conductive coating:

[0117] Step S21: weighing a saturated polyester resin, an epoxy resin and a reactive diluent, adding them into a reaction kettle and stirring them evenly to form a resin mixture;

[0118] Step S22: adding a thermal conductive filler, silicon powder, molybdenum disulfide and a dispersant to the resin mixture in sequence, and stirring the mixture to uniformly disperse the thermal conductive filler; then adding a coupling agent, and continuing stirring the reaction;

[0119] Step S23: continue to add the cationic initiator to the uniformly mixed coating, and continue to stir until the cationic initiator is completely dissolved;

[0120] Step S24: finally, adding an antioxidant, a leveling agent and a pigment, stirring evenly and then stopping the stirring, filtering the mixed coating to remove impurities and incompletely dispersed particles;

[0121] Step S25: adding a defoamer to the filtered coating and stirring evenly to obtain a composite thermal conductive coating.

[0122] Comparative Example 1

[0123] The difference from Example 1 is that no modified polyvinylidene fluoride is added.

[0124] Comparative Example 2

[0125] The difference from Example 1 is that no aluminum nitride is added.

[0126] Comparative Example 3

[0127] The difference from Example 1 is that modified polyvinylidene fluoride and aluminum nitride are not added.

[0128] Comparative Example 4

[0129] The difference from Example 1 is that no propylene glycol diacrylate was added.

[0130] Comparative Example 5

[0131] The difference from Example 1 is that no silicon powder is added.

[0132] Comparative Example 6

[0133] The difference from Example 1 is that molybdenum disulfide is not added.

[0134] Comparative Example 7

[0135] The formula of the composite thermal conductive coating is the same as that of Example 1 except for the modified polyvinylidene fluoride.

[0136] Preparation method: Except for the different ratios of aluminum oxide, boron nitride and polyvinylidene fluoride, the rest is the same as Example 1. In terms of weight percentage, 30 wt% of aluminum oxide, 30 wt% of boron nitride and 40 wt% of polyvinylidene fluoride are taken.

[0137] The coatings prepared in Examples 1-5 and Comparative Examples 1-7 were subjected to surface coating adhesion test (GB / T 9286-2021), thermal conductivity test, wear resistance test (GB / T 1768-2006), heat resistance test (GB / T 1735-2009), acid salt spray (AASS) test (GB / T 10125-2012), alkali resistance test (10% NaOH solution immersion), impact resistance test (GB / T5095.5-1997; 50 cm, 500 g). The following are the specific test results.

[0138] Table 1 Test results

[0139]

[0140] As can be seen from the above table, from Example 1 to Example 5, it is shown that the coating formed by the composite thermal conductive coating of the present application has excellent thermal conductivity and adhesion performance, good strength and corrosion resistance; from Example 1, Example 4, Example 5 and Comparative Example 7, by changing the ratio of the two modified substances in the modified polyvinylidene fluoride, the thermal conductivity of the coating will be affected. Specifically, when the amount of aluminum oxide is fixed, the more the amount of boron nitride is used, the better the thermal conductivity of the coating, and when the boron nitride is 20wt%, the thermal conductivity is the best. From Example 1 and Comparative Examples 1-3, it can be seen that modified polyvinylidene fluoride can significantly improve the thermal conductivity of the coating, and aluminum nitride can form a synergistic effect with modified polyvinylidene fluoride to further improve the thermal conductivity of the coating. From Example 1 and Comparative Example 4, it can be seen that in the absence of the addition of reactive diluent, the comprehensive properties of the coating such as adhesion and thermal conductivity are slightly reduced. It can be seen from Example 1 and Comparative Examples 5 and 6 that silicon micropowder can improve the mechanical strength and wear resistance of the coating, and molybdenum disulfide can significantly improve the corrosion resistance of the coating in addition to improving the wear resistance of the coating.

[0141] The above are only preferred embodiments of the present invention, and are not intended to limit the patent scope of the present invention. Any equivalent structure or equivalent process transformation made using the contents of the present invention specification, or directly or indirectly applied in other related technical fields, are also included in the patent protection scope of the present invention.

Claims

1. A composite thermal conductive coating for electronic products, characterized in that: In parts by weight, it includes: 40-60 parts of saturated polyester resin, 20-30 parts of epoxy resin, 30-50 parts of active diluent, 20-40 parts of thermal conductive filler, 10-20 parts of silicon micropowder, 10-20 parts of molybdenum disulfide, 1-5 parts of coupling agent, 0.5-2 parts of cationic initiator, 0.5-2 parts of antioxidant, 0.1-1 parts of leveling agent, 1-5 parts of pigment, 0.5-2 parts of dispersant, and 0.1-0.5 parts of defoaming agent; The active diluent is dipropylene glycol diacrylate or tripropylene glycol diacrylate; In parts by weight, the thermal conductive filler comprises 5-10 parts of aluminum nitride and 15-30 parts of modified polyvinylidene fluoride, wherein the modified polyvinylidene fluoride is modified by aluminum oxide and boron nitride. The preparation of the modified polyvinylidene fluoride comprises the following steps: Step S11: taking 30 wt % of aluminum oxide, 10-20 wt % of boron nitride and 50-60 wt % of polyvinylidene fluoride by weight percentage, dissolving the polyvinylidene fluoride in N,N-dimethylformamide to obtain a mixed solution; Step S12: adding aluminum oxide and boron nitride to the mixed solution and dispersing for 15-30 minutes; Step S13: pouring the dispersed mixed solution into deionized water to form a precipitate; filtering the precipitate, and vacuum drying it at 70° C. for 24 hours; Step S14: The obtained composite is hot-pressed at 200° C. and 10 MPa for 2 min to obtain modified polyvinylidene fluoride.

2. The composite thermal conductive coating for electronic products according to claim 1, characterized in that: Calculated in parts by weight, it includes: 45-55 parts of saturated polyester resin, 23-28 parts of epoxy resin, 35-45 parts of active diluent, 25-35 parts of thermal conductive filler, 10-18 parts of silicon micropowder, 12-18 parts of molybdenum disulfide, 2-5 parts of coupling agent, 1-2 parts of cationic initiator, 1-2 parts of antioxidant, 0.1-1 parts of leveling agent, 1-5 parts of pigment, 1-2 parts of dispersant and 0.1-0.5 parts of defoaming agent.

3. The composite thermal conductive coating for electronic products according to claim 2, characterized in that: Calculated in parts by weight, it includes: 45-50 parts of saturated polyester resin, 23-25 ​​parts of epoxy resin, 35-40 parts of active diluent, 25-30 parts of thermal conductive filler, 10-15 parts of silicon micropowder, 12-15 parts of molybdenum disulfide, 2-5 parts of coupling agent, 1-2 parts of cationic initiator, 1-2 parts of antioxidant, 0.1-1 parts of leveling agent, 2-5 parts of pigment, 1-2 parts of dispersant and 0.1-0.5 parts of defoaming agent.

4. The composite thermal conductive coating for electronic products according to claim 1, characterized in that: The boron nitride is hexagonal boron nitride nanosheets.

5. The composite thermal conductive coating for electronic products according to claim 1, characterized in that: The coupling agent is a silane coupling agent or a titanate coupling agent.

6. The composite thermal conductive coating for electronic products according to claim 1, characterized in that: The cationic initiator is diphenyl-(4-phenylthio)phenylsulfonium hexafluoroantimonate and / or diphenyl-(4-phenylthio)phenylsulfonium hexafluorophosphate.

7. A method for preparing a composite thermally conductive coating for electronic products, used for preparing the composite thermally conductive coating for electronic products according to any one of claims 1 to 6, characterized in that: The following steps are involved: Step S21: weighing a saturated polyester resin, an epoxy resin and a reactive diluent, adding them into a reaction kettle and stirring them evenly to form a resin mixture; Step S22: adding a thermal conductive filler, silicon powder, molybdenum disulfide and a dispersant to the resin mixture in sequence, and stirring the mixture to uniformly disperse the thermal conductive filler; then adding a coupling agent, and continuing stirring the reaction; Step S23: After mixing evenly, continue to add cationic initiator, and continue stirring until the cationic initiator is completely dissolved; Step S24: finally adding an antioxidant, a leveling agent and a pigment, stirring evenly and then stopping stirring, filtering the mixture to remove impurities and incompletely dispersed particles; Step S25: adding a defoaming agent to the filtered mixture and stirring evenly to obtain a composite thermal conductive coating.

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