Insulating temperature-resistant heat-dissipating coating and preparation method thereof

Abstract

The present application relates to a kind of insulating temperature-resistant heat dissipation coatings, comprising the following mass ratio of components: 40-60 parts of polymethylsilicone resin, 4-8 parts of butyl acetate, 4-8 parts of n-butanol, 25-40 parts of silicon carbide, 5-15 parts of propylene glycol methyl ether acetate, wherein, the polymethylsilicone resin " O-Si-O " structure content is 30-50wt%, methoxyl content is 20-40wt%; The purity of the silicon carbide is 99.9%.The present application also provides a kind of preparation method of insulating temperature-resistant heat dissipation coatings, S1: the butyl acetate and the n-butanol are added to the polymethylsilicone resin, and pre-curing is carried out under the condition that temperature is 40-50 DEG C and rotation speed is 500-800 r / min, to obtain curing material;S2: under the condition that rotation speed is 1500-2000 r / min, the silicon carbide is added to curing material, after the silicon carbide is uniformly dispersed, propylene glycol methyl ether acetate is further added, to obtain dispersion liquid;S3: the dispersion liquid is filtered using 150 mesh filter screen, to obtain insulating temperature-resistant heat dissipation coatings.The insulating temperature-resistant heat dissipation coatings prepared by the present application can resist high temperature up to 400 DEG C, and the breakdown voltage is greater than 15KV / mm.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of paint, in particular to an insulating heat-resistant heat-dissipating paint and a preparation method thereof. BACKGROUND

[0002] At present, the heat-dissipating paint system commonly used in industry at room temperature is generally ordinary acrylic amino baking paint and polyurethane system, and materials such as graphite and graphene with good thermal conductivity and strong electrical conductivity are often selected, but the heat resistance of such products is relatively poor, and they cannot meet the needs of long-term use at a temperature of more than 200℃ in power generation devices and other use scenarios with high insulation requirements. In particular, on internal combustion locomotives, the space is small, and the heat-resistant heat-dissipating and insulating properties of the paint are required to be higher. SUMMARY

[0003] Therefore, the present application provides an insulating heat-resistant heat-dissipating paint with a heat resistance of up to 400℃ and a breakdown voltage of more than 15KV / mm.

[0004] First aspect:

[0005] An insulating heat-resistant heat-dissipating paint comprises the following components in mass ratio:

[0006]

[0007] In the present application, the content of "O-Si-O" structure in the polymethylsilicone is 30-50wt%, and the content of methoxy is 20-40wt%; the purity of silicon carbide is 99.9%.

[0008] In the present application, if the content of "O-Si-O" structure and methoxy is too low, the heat resistance and insulation of the film-forming material are poor, and the film cannot achieve a heat resistance of 400℃ and good insulation performance; if the content of silicon dioxide is higher than 50% and the content of methoxy is higher than 40%, the film-forming shrinkage ratio is too large, resulting in poor film-forming continuity, needle hole discharge effect, and finally the insulation of the film does not meet the standard. In the impurities in silicon carbide, there are oxides, nitrides, aluminum, iron and other substances, and if the purity of silicon carbide is too low, the conductivity of these impurities is strong, which greatly reduces the insulation of the coating; in addition, the heat radiation ability of aluminum, iron and other substances is weaker than that of silicon carbide, which affects the heat dissipation effect. In the present application, the synergistic effect of the polymethylsilicone, butyl acetate, n-butanol, silicon carbide and propylene glycol methyl ether acetate with a limited weight fraction is used to prepare an insulating heat-resistant heat-dissipating paint with a heat resistance of up to 400℃ and a breakdown voltage of more than 15KV / mm, which is suitable for use in high-temperature-resistant heat-dissipating and insulating environments such as rail transit.

[0009] As a preferred solution, the silicon carbide particle size is 30-50 μm, if the silicon carbide particle size is less than 30 μm, the grinding time is uncontrollable during dispersion grinding, and the average particle size is too small after dispersion; if the silicon carbide particle size is greater than 50 μm, due to the high hardness of silicon carbide, the material of the dispersion grinding equipment will be worn and doped into the paint, affecting the heat dissipation effect.

[0010] As a preferred solution, the n-butanol purity is greater than 99.5%, the butyl acetate purity is greater than 99.5%, and the propylene glycol methyl ether acetate purity is greater than 99.5%. The n-butanol, butyl acetate and propylene glycol methyl ether acetate are used as solvents, part of the impurities is water, if the water content is too high, it is easy to make the methoxy of the paint hydrolyze too much, so that the paint is unstable or gelled; another part of the impurities is other solutes, if the content of other solutes is too high, it may affect the designed solvent evaporation gradient of the paint during construction, thereby affecting the film forming quality of the paint, resulting in a decrease in insulation or temperature resistance.

[0011] The second aspect is:

[0012] A preparation method of the insulating temperature-resistant heat dissipation paint according to the first aspect, comprising the following steps:

[0013] S1: adding the butyl acetate and the n-butanol to the polymethylsilicone resin, pre-matured at a temperature of 40-50 ℃ and a rotation speed of 500-800 r / min, to obtain a matured material;

[0014] S2: adding the silicon carbide to the matured material at a rotation speed of 1500-2000 r / min, and then adding the propylene glycol methyl ether acetate after the silicon carbide is uniformly dispersed, to obtain a dispersion liquid;

[0015] S3: filtering the dispersion liquid using a 150-mesh filter screen to obtain the insulating temperature-resistant heat dissipation paint.

[0016] In step S1, the polymethylsilicone resin is slightly hydrolyzed and slightly polycondensed with water in the solvent, which is called maturation. This step increases the system viscosity and improves the storage stability of silicon carbide in the system and the film forming quality, thereby ensuring the insulation and heat dissipation properties of the film after film forming. The n-butanol contains active hydroxyl groups, which can control the maturation speed, and the butyl acetate can reduce the system viscosity during maturation, so that the maturation is more complete.

[0017] In step S2, the matured material is dispersed and mixed with the silicon carbide, and the propylene glycol methyl ether acetate has a slower evaporation speed than the n-butyl acetate and the butyl acetate, which can better adjust the overall evaporation speed of the system to improve the workability and film forming quality of the coating film.

[0018] As a preferred solution, the pre-curing time in step S1 is 3-4h, and the curing time is too short, the curing degree is not enough, the system viscosity is not enough, and the construction and film forming quality are affected.

[0019] As a preferred solution, in step S2, the dispersion time after adding silicon carbide is 30-50min.

[0020] As a preferred solution, in step S2, the particle size of the ground silicon carbide is 20-30μm, if the particle size of the silicon carbide is less than 20μm, the specific surface area is large with the same addition amount, the silicon carbide cannot be completely wrapped after the coating is formed, thereby affecting the continuity of the coating film, and further affecting the high temperature resistance and insulation; if the particle size of the silicon carbide is greater than 30μm, the specific surface area is small with the same addition amount, the external heat radiation area is small, and the heat dissipation effect is not up to standard, and the silicon carbide is ground to a particle size of 20-30μm to balance the insulation and heat dissipation.

[0021] As a preferred solution, in step S2, after adding propylene glycol methyl ether acetate, it is dispersed for 5min. DETAILED DESCRIPTION

[0022] In order to further understand the present application, the present application will be described in detail below in combination with examples, but it should be noted that the examples do not constitute a limitation on the scope of protection of the present application.

[0023] An insulating temperature-resistant heat-dissipating coating, comprising the following components in mass ratio:

[0024]

[0025] Among them, the content of "O-Si-O" structure in the polymethylsilicone resin is 30-50wt%, and the methoxy content is 20-40wt%; the purity of the silicon carbide is 99.9%, and the particle size is 30-50μm; the purity of the n-butanol is greater than 99.5%, and the purity of the butyl acetate is greater than 99.5%.

[0026] A preparation method of an insulating temperature-resistant heat-dissipating coating, comprising the following steps:

[0027] S1: adding the butyl acetate and the n-butanol to the polymethylsilicone resin, pre-curing for 3-4h at a temperature of 40-50℃ and a rotation speed of 500-800r / min, to obtain a curing material;

[0028] S2: adding the silicon carbide to the curing material under a rotation speed of 1500-2000r / min, dispersing for 30-50min, dispersing the average particle size of the silicon carbide to 20-30μm, adding the propylene glycol methyl ether acetate, and dispersing for 5min, to obtain a dispersion liquid;

[0029] S3: filtering the dispersion liquid using a 150-mesh filter to obtain the insulating heat-resistant and heat-dissipating coating.

[0030] Example 1

[0031] An insulating heat-resistant and heat-dissipating coating includes the following components in mass ratio:

[0032]

[0033] The content of "O-Si-O" structure in the polymethylsilicone resin is 30 wt%, and the content of methoxy group is 20 wt%; the purity of the silicon carbide is 99.9%, and the particle size is 40 μm; the purity of the n-butanol is greater than 99.5%, and the purity of the butyl acetate is greater than 99.5%.

[0034] A preparation method of an insulating heat-resistant and heat-dissipating coating includes the following steps:

[0035] S1: adding the butyl acetate and the n-butanol to the polymethylsilicone resin, and pre-matured for 3 h under the condition of temperature of 40 ℃ and rotation speed of 500 r / min to obtain a matured material;

[0036] S2: adding the silicon carbide to the matured material under the condition of rotation speed of 1500 r / min, and dispersing for 40 min to disperse the average particle size of the silicon carbide to 25 μm, and then adding the propylene glycol methyl ether acetate, and dispersing for 5 min to obtain a dispersion liquid;

[0037] S3: filtering the dispersion liquid using a 150-mesh filter to obtain the insulating heat-resistant and heat-dissipating coating.

[0038] Example 2

[0039] An insulating heat-resistant and heat-dissipating coating includes the following components in mass ratio:

[0040]

[0041] The content of "O-Si-O" structure in the polymethylsilicone resin is 50 wt%, and the content of methoxy group is 30 wt%; the purity of the silicon carbide is 99.9%, and the particle size is 50 μm; the purity of the n-butanol is greater than 99.5%, and the purity of the butyl acetate is greater than 99.5%.

[0042] A preparation method of an insulating heat-resistant and heat-dissipating coating includes the following steps:

[0043] S1: adding the butyl acetate and the n-butanol to the polymethylsilicone resin, and pre-matured for 4 h under the condition of temperature of 45 ℃ and rotation speed of 600 r / min to obtain a matured material;

[0044] S2: under the condition of 2000r / min, add the silicon carbide to the maturation material, disperse for 30min, disperse the average particle size of silicon carbide to 20μm, then add the propylene glycol methyl ether acetate, disperse for 5min, to obtain a dispersion liquid;

[0045] S3: filter the dispersion liquid using a 150-mesh filter screen to obtain an insulating temperature-resistant heat-dissipating coating.

[0046] Example 3

[0047] An insulating temperature-resistant heat-dissipating coating includes the following components in the mass ratio:

[0048]

[0049] The "O-Si-O" structure content in the polymethylsilicone resin is 40wt%, the methoxy content is 40wt%, the purity of the silicon carbide is 99.9%, and the particle size is 30μm; the purity of the n-butanol is greater than 99.5%, and the purity of the butyl acetate is greater than 99.5%.

[0050] A preparation method of an insulating temperature-resistant heat-dissipating coating includes the following steps:

[0051] S1: add the butyl acetate and the n-butanol to the polymethylsilicone resin, and pre-mature under the condition of 50℃ and 800r / min for 4h to obtain a maturation material;

[0052] S2: under the condition of 1800r / min, add the silicon carbide to the maturation material, disperse for 50min, disperse the average particle size of silicon carbide to 20μm, then add the propylene glycol methyl ether acetate, disperse for 5min, to obtain a dispersion liquid;

[0053] S3: filter the dispersion liquid using a 150-mesh filter screen to obtain an insulating temperature-resistant heat-dissipating coating.

[0054] Example 4

[0055] An insulating temperature-resistant heat-dissipating coating includes the following components in the mass ratio:

[0056]

[0057] The "O-Si-O" structure content in the polymethylsilicone resin is 45wt%, the methoxy content is 35wt%, the purity of the silicon carbide is 99.9%, and the particle size is 50μm; the purity of the n-butanol is greater than 99.5%, and the purity of the butyl acetate is greater than 99.5%.

[0058] A preparation method of an insulating temperature-resistant heat-dissipating coating includes the following steps:

[0059] S1: adding the butyl acetate and the n-butanol to the polymethylsilicone resin, and pre-maturing for 3 h at a temperature of 40 DEG C and a rotating speed of 800 r / min to obtain a matured material;

[0060] S2: adding the silicon carbide to the matured material at a rotating speed of 1600 r / min, and dispersing for 50 min to disperse the silicon carbide to an average particle size of 30 mu m, then adding the propylene glycol methyl ether acetate, and dispersing for 5 min to obtain a dispersion liquid;

[0061] S3: filtering the dispersion liquid using a 150-mesh filter screen to obtain the insulating temperature-resistant heat-dissipating coating.

[0062] Example 5

[0063] An insulating temperature-resistant heat-dissipating coating includes the following components in a mass ratio:

[0064]

[0065]

[0066] The polymethylsilicone resin has a content of "O-Si-O" structure of 35 wt%, and a methoxy content of 25 wt%; the silicon carbide has a purity of 99.9% and a particle size of 45 mu m; the n-butanol has a purity of greater than 99.5%, and the butyl acetate has a purity of greater than 99.5%.

[0067] A preparation method of an insulating temperature-resistant heat-dissipating coating includes the following steps:

[0068] S1: adding the butyl acetate and the n-butanol to the polymethylsilicone resin, and pre-maturing for 4 h at a temperature of 45 DEG C and a rotating speed of 600 r / min to obtain a matured material;

[0069] S2: adding the silicon carbide to the matured material at a rotating speed of 2000 r / min, and dispersing for 40 min to disperse the silicon carbide to an average particle size of 20 mu m, then adding the propylene glycol methyl ether acetate, and dispersing for 5 min to obtain a dispersion liquid;

[0070] S3: filtering the dispersion liquid using a 150-mesh filter screen to obtain the insulating temperature-resistant heat-dissipating coating.

[0071] Comparative Example 1

[0072] An insulating temperature-resistant heat-dissipating coating includes the following components in a mass ratio:

[0073]

[0074] The "O-Si-O" structure content in the polymethyl silicone resin is 10 wt%, the methoxy content is 15 wt%, the purity of the silicon carbide is 99.9%, the particle size is 40 μm, the purity of the n-butanol is greater than 99.5%, and the purity of the butyl acetate is greater than 99.5%.

[0075] A preparation method of an insulating heat-resistant heat-dissipating coating, comprising the following steps:

[0076] S1: adding the butyl acetate and the n-butanol to the polymethyl silicone resin, and pre-maturing for 3 h under the condition that the temperature is 40 DEG C and the rotating speed is 500 r / min, to obtain a matured material;

[0077] S2: adding the silicon carbide to the matured material under the condition that the rotating speed is 1500 r / min, and dispersing for 40 min, so that the average particle size of the silicon carbide is dispersed to 25 μm, then adding the propylene glycol methyl ether acetate, and dispersing for 5 min, to obtain a dispersion liquid;

[0078] S3: filtering the dispersion liquid by using a 150-mesh filter screen, to obtain the insulating heat-resistant heat-dissipating coating.

[0079] Comparative Example 2

[0080] An insulating heat-resistant heat-dissipating coating, comprising the following components in mass ratio:

[0081]

[0082]

[0083] The "O-Si-O" structure content in the polymethyl silicone resin is 30 wt%, the methoxy content is 20 wt%, the purity of the silicon carbide is 99.9%, the particle size is 60 μm, the purity of the n-butanol is greater than 99.5%, and the purity of the butyl acetate is greater than 99.5%.

[0084] A preparation method of an insulating heat-resistant heat-dissipating coating, comprising the following steps:

[0085] S1: adding the butyl acetate and the n-butanol to the polymethyl silicone resin, and pre-maturing for 3 h under the condition that the temperature is 40 DEG C and the rotating speed is 500 r / min, to obtain a matured material;

[0086] S2: adding the silicon carbide to the matured material under the condition that the rotating speed is 2000 r / min, and dispersing for 60 min, so that the average particle size of the silicon carbide is dispersed to 40 μm, then adding the propylene glycol methyl ether acetate, and dispersing for 5 min, to obtain a dispersion liquid;

[0087] S3: filtering the dispersion liquid by using a 150-mesh filter screen, to obtain the insulating heat-resistant heat-dissipating coating.

[0088] Comparative Example 3

[0089] An insulating heat-resistant heat-dissipating coating, comprising the following components in mass ratio:

[0090]

[0091] wherein the content of "O-Si-O" structure in the polymethylsilicone resin is 30wt%, the content of methoxy group is 20wt%; the purity of silicon carbide is 98%, the particle size is 40um; the purity of n-butanol is greater than 99%, the purity of butyl acetate is greater than 99%.

[0092] A preparation method of an insulating heat-resistant heat-dissipating coating, comprising the following steps:

[0093] S1: adding butyl acetate and n-butanol to the polymethylsilicone resin, and pre-matured for 3h under the condition of temperature 40℃ and rotation speed 500r / min, to obtain a matured material;

[0094] S2: adding silicon carbide to the matured material under the condition of rotation speed 1500r / min, and dispersing for 40min to disperse the average particle size of silicon carbide to 25um, then adding propylene glycol methyl ether acetate and dispersing for 5min to obtain a dispersion liquid;

[0095] S3: filtering the dispersion liquid using a 150-mesh filter screen to obtain an insulating heat-resistant heat-dissipating coating.

[0096] Table 1: Performance detection general situation of examples 1-3 and comparative examples 1-3

[0097]

[0098] Example 1 is a preferred embodiment of the present application. As can be seen from comparative example 1 and example 1, if the content of "O-Si-O" structure in the polymethylsilicone resin is too low, the insulation and temperature resistance of the coating after film formation will decrease; if the content of methoxy group is too low, the crosslinking density after film formation will be low, resulting in the decrease of insulation and temperature resistance. As can be seen from comparative example 2 and example 1, if the particle size of silicon carbide is large, it is still difficult to reduce the average particle size of silicon carbide after dispersing for 60min at 2000r / min, so that the surface area of silicon carbide is small, which in turn leads to small heat-dissipating area and poor heat-dissipating property of the coating after film formation. As can be seen from comparative example 3 and example 1, if the purity of silicon carbide is low, the insulation and temperature resistance of the coating after film formation will decrease; if the purity of n-butanol and butyl acetate is low, the insulation and temperature resistance of the coating after film formation will also be affected.

[0099] The above embodiments only express several implementation manners of the present application, and the description is more specific and detailed, but it should not be understood as a limitation on the scope of the patent. It should be noted that for ordinary skilled in the art, without departing from the concept of the present application, several modifications and improvements can be made, which are within the scope of protection of the present application.

Claims

1. A method for preparing an insulating heat-resistant heat-dissipating coating, characterized in that, The method comprises the following steps: The following components are weighed: The purity of the silicon carbide is 99.9%, the particle size of the silicon carbide is 30-50 microns, the purity of the n-butanol is greater than 99.5%, the purity of the butyl acetate is greater than 99.5%, and the purity of the propylene glycol methyl ether acetate is greater than 99.5%; S1: The butyl acetate and the n-butanol are added to the polymethylsilicone resin, and pre-curing is performed at a temperature of 40-50°C and a rotation speed of 500-800 r / min to obtain a cured material; S2: The silicon carbide is added to the cured material at a rotation speed of 1500-2000 r / min, and the silicon carbide is dispersed to a particle size of 20-30 microns, and then the propylene glycol methyl ether acetate is added to obtain a dispersion liquid; S3: The dispersion liquid is filtered using a 150-mesh filter screen to obtain an insulating heat-resistant and heat-dissipating coating.

2. The method for preparing an insulating, heat-resistant, and heat-dissipating coating according to claim 1, characterized in that, The pre-curing time in the step S1 is 3-4 hours.

3. The method for preparing an insulating, heat-resistant, and heat-dissipating coating according to claim 1, characterized in that, In the step S2, the dispersion time after adding the silicon carbide is 30-50 minutes.

4. The method for preparing an insulating, heat-resistant, and heat-dissipating coating according to claim 1, characterized in that, In the step S2, the dispersion time after adding the propylene glycol methyl ether acetate is 5 minutes.

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