Novel radiation heat insulation composite coating

Abstract

The invention relates to a novel radiation heat insulation composite coating, which comprises a far infrared band high emissivity coating with the thickness of 0.5-5mm and a high reflectivity coating at the band, and the thickness of the high reflectivity coating is 30-100mu m. The composite coating contains hollow ceramic microbeads and aerogel powder which are arranged in a specific mode, besides the heat conductivity coefficient of about 0.05 W / hk, the composite coating has 99% of infrared vertical emissivity in the range of 5-50 microns, middle and far infrared waves are continuously refracted through an internal porous and spherical hollow structure, and finally path reflection is formed, so that the composite coating has excellent radiation heat insulation and heat preservation performance, and the service life of the composite coating is prolonged. The thermal resistance of 0.5 m.k / w can be achieved by the thickness of 2mm, the thermal insulation performance of the thermal insulation material is at least equal to that of a traditional thermal insulation material with the thickness of 2-3 times, and the adhesive force, the wear resistance and the stone impact resistance are excellent.

Description

Technical Field

[0001] The present invention relates to the field of thermal insulation coatings, and particularly to a novel radiation thermal insulation composite coating. Background Art

[0002] Thermal insulation materials are widely used in various fields. To achieve an effective thermal insulation effect, their thermal resistance needs to reach 0.3 - 0.5 m 2 .k / w. Traditional thermal insulation materials need 10 - 30 mm to achieve an effective thermal insulation effect, and their thickness is too large, with many limitations in use. Therefore, there is an urgent need to design a composite coating that can achieve an effective thermal insulation effect and has an overall thickness. Summary of the Invention

[0003] The object of the present invention is to provide a novel radiation thermal insulation composite coating, which has a good thermal resistance through the superposition combination of a high emissivity coating and a high reflectivity coating, and its thickness is much lower than that of traditional thermal insulation materials, and can solve the problems of the limitations in the use of traditional thermal insulation materials.

[0004] To achieve the above object, the technical solution adopted by the present invention is: a novel radiation thermal insulation composite coating, including a far-infrared band high emissivity coating with a thickness of 0.5 - 5 mm and a high reflectivity coating in this band, and the thickness of the high reflectivity coating is 30 μm - 100 μm. Preferably, the far-infrared band is specifically the 3 - 14 μm band.

[0005] Preferably, the composite coating structure is divided into two usage scenarios. The coating sequence for heat insulation requirements is a high reflectivity coating and a high emissivity coating (see Figure 1 ); the coating sequence for heat preservation requirements is a high emissivity coating and a high reflectivity coating (see Figure 2 ).

[0006] Preferably, the high emissivity coating is the coating disclosed in Chinese Patent CN118185407B, which is composed of one or several of resin, additives, hollow glass microspheres and aerogel powder. It has a high reflectivity in the wavelength range of 3-14μm, and the thermal conductivity is generally <0.1w / (h.k). This high emissivity is mainly generated by its microscopic physical structure mechanism. When heat is transferred from the high-temperature interface of the coating to the low-temperature interface of the coating, in addition to the heat transfer contribution brought by the heat conduction mechanism, due to the high reflectivity of the coating and the hollow structure inside it allowing thermal radiation to penetrate inside, thermal radiation occupies an important part of the heat transfer contribution; furthermore, due to the hollow spherical structure of the glass microspheres and the porous structure of the aerogel powder, thermal radiation forms multiple refractions and absorptions inside, causing a large part of it to be refracted back on the transmission path, so it has good heat insulation performance; there is a prerequisite for this heat transfer mechanism that the high-temperature side has a certain thermal inertia and heat storage, that is, it can maintain a temperature difference between the high-temperature interface and the low-temperature interface of the coating for a long time. This is the prerequisite for thermal radiation to occupy an important contribution in internal heat transfer. Otherwise, if there is no obvious temperature difference between the high-temperature interface and the low-temperature interface of the coating, then heat transfer mainly depends on heat conduction.

[0007] Preferably, the high reflectivity coating comprises the following components: waterborne resin, water, dispersant, wetting agent, defoaming agent, film-forming aid, aluminum powder, leveling agent, cellulose thickener.

[0008] Preferably, the waterborne resin is 50%, water is 35.3%, dispersant is 1%, wetting agent is 0.5%, defoaming agent is 0.2%, film-forming aid is 2%, aluminum powder is 10%, leveling agent is 0.5%, and cellulose thickener is 0.5%.

[0009] Preferably, the aluminum powder is alumina powder with a particle size between 10-70μm, and the effect is best when it is 50-70μm.

[0010] Preferably, the resin is polyurethane resin, epoxy resin, alkyd resin, acrylic resin and their modified resins.

[0011] Preferably, the high reflectivity coating can be prepared by the following steps: ① Place the waterborne resin emulsion, dispersant, wetting agent, film-forming aid, leveling agent, defoaming agent and deionized water in a stirring container, turn on the stirrer, and adjust the speed to 500rpm and stir for 5 minutes; ② Add the aluminum powder to the stirring container, turn on the stirrer, and adjust the speed to 1000rpm and stir for 10 minutes; ③ Add the cellulose thickener to the stirring container, turn on the stirrer at 1000rpm and stir for 10-15 minutes; ④ Add the defoaming agent again, turn on the stirrer at 1000rpm and stir for 5 minutes.

[0012] The technical effects of the present invention are as follows: The composite coating contains hollow ceramic microspheres and aerogel powder in a specific arrangement. In addition to a thermal conductivity of about 0.05 W / hk, it has an infrared normal emissivity of 99% in the range of 5 - 50 μm. Its internal porous and spherical hollow structure enables the continuous refraction of mid- and far-infrared waves, ultimately forming path reflection, endowing it with excellent radiative heat insulation and thermal insulation performance. A 2-mm thickness can achieve a thermal resistance of 0.5 m 2 .k / w, which is at least equivalent to the thermal insulation performance of traditional thermal insulation materials with a thickness 2 - 3 times that of this material. Moreover, it has excellent adhesion, abrasion resistance, and stone impact resistance. Description of the Drawings

[0013] Figure 1 Schematic diagram of the composite coating application in the case of heat insulation (cold insulation).

[0014] Figure 2 Schematic diagram of the composite coating application in the case of heat preservation.

[0015] Figure 3 Schematic diagram of the experiment.

[0016] Figure 4 Test curve graph for application to an automotive battery pack. Detailed Embodiments

[0017] In order to make the objectives, technical solutions, and advantages of the present invention more clearly understood, the following further elaborates on the present invention in conjunction with embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention. In addition, the technical features involved in the various embodiments of the present invention described below can be combined with each other as long as they do not conflict with each other.

[0018] The embodiments and corresponding comparative examples of the present invention are as follows:

[0019] Embodiment 1 (Cold Insulation)

[0020] 1) According to the method in Patent CN118185407B, place acrylic resin emulsion, dispersant, and deionized water in a stirring container, start the stirrer, and stir at a speed of 500 rpm for 5 minutes; add a film-forming aid (DB / ETB), aerogel slurry (previously stirred evenly with deionized water), and glass microspheres to the stirring container, start the stirrer, and stir at a speed of 1000 rpm for 10 - 15 minutes; add a thickener to the stirring container, start the stirrer, and stir at a speed of 1500 rpm for 10 minutes; thus obtain a high-emissivity coating (aerogel hollow glass microsphere heat-insulating waterborne coating);

[0021] 2) Place the aqueous resin emulsion, dispersant, wetting agent, film-forming aid, leveling agent, defoaming agent, and deionized water in a stirring container. Start the stirrer and adjust the speed to 500 rpm and stir for 5 minutes; ②

[0022] Add aluminum powder to the stirring container. Start the stirrer and adjust the speed to 1000 rpm and stir for 10 minutes; ③ Add the cellulose thickener to the stirring container. Start the stirrer at 1000 rpm and stir for 10 - 15 minutes; ④

[0023] Add the defoaming agent again. Start the stirrer at 1000 rpm and stir for 5 minutes. The high-reflectivity coating is prepared.

[0024] 3) Spray the high-reflectivity coating prepared in step 2 on the substrate with a spraying thickness of 65 μm, and let it cure naturally for 30 min until the surface is dry;

[0025] 4) Spray the high-emissivity coating (aerogel hollow glass microsphere heat-insulating aqueous coating) prepared in step 1 on the high-reflectivity coating with a spraying thickness of 3.0 mm, and let it cure naturally to obtain the radiation heat-insulating composite coating.

[0026] Example 2 (thermal insulation)

[0027] 1) According to the method in Patent CN118185407B, place the acrylic resin emulsion, dispersant, and deionized water in a stirring container. Start the stirrer and adjust the speed to 500 rpm and stir for 5 minutes; Add the film-forming aid (DB / ETB), aerogel slurry (previously stirred evenly with deionized water), and glass microspheres to the stirring container. Start the stirrer and adjust the speed to 1000 rpm and stir for 10 - 15 minutes; Add the thickener to the stirring container. Start the stirrer and adjust the speed to 1500 rpm and stir for 10 minutes; The high-emissivity coating (aerogel hollow glass microsphere heat-insulating aqueous coating) is prepared by the above method;

[0028] 2) Place the aqueous resin emulsion, dispersant, wetting agent, film-forming aid, leveling agent, defoaming agent, and deionized water in a stirring container. Start the stirrer and adjust the speed to 500 rpm and stir for 5 minutes; ② Add aluminum powder to the stirring container. Start the stirrer and adjust the speed to 1000 rpm and stir for 10 minutes; ③ Add the cellulose thickener to the stirring container. Start the stirrer at 1000 rpm and stir for 10 - 15 minutes; ④ Add the defoaming agent again. Start the stirrer at 1000 rpm and stir for 5 minutes. The high-reflectivity coating is prepared.

[0029] 3) Spray the high-emissivity coating (aerogel hollow glass microsphere heat-insulating aqueous coating) prepared in step 1 on the substrate with a spraying thickness of 3.0 mm, and let it cure naturally.

[0030] 4) Spray the high-reflectivity coating prepared in step 2 on the high-emissivity coating with a spraying thickness of 65 μm, and let it cure naturally for 30 min until the surface is dry to obtain the radiation heat-insulating composite coating.

[0031] Example 3 (cold insulation)

[0032] 1) According to the method in Patent CN118185407B, put the acrylic resin emulsion, dispersant and deionized water into a stirring container, start the stirrer, and stir at a speed of 500 rpm for 5 minutes; add the film-forming aid (DB / ETB), aerogel slurry (previously stirred evenly with deionized water), and glass microspheres into the stirring container, start the stirrer, and stir at a speed of 1000 rpm for 10 - 15 minutes; add the thickener into the stirring container, start the stirrer, and stir at a speed of 1500 rpm for 10 minutes; the high-emissivity coating (aerogel hollow glass microsphere heat-insulating waterborne coating) prepared by the above method;

[0033] 2) Put the waterborne resin emulsion, dispersant, wetting agent, film-forming aid, leveling agent, defoaming agent and deionized water into a stirring container, start the stirrer, and stir at a speed of 500 rpm for 5 minutes; ② Add aluminum powder into the stirring container, start the stirrer, and stir at a speed of 1000 rpm for 10 minutes; ③ Add the cellulose thickener into the stirring container, start the stirrer at a speed of 1000 rpm and stir for 10 - 15 minutes; ④ Add the defoaming agent again, start the stirrer at a speed of 1000 rpm and stir for 5 minutes. Obtain the high-reflectivity coating.

[0034] 3) Spray the high-reflectivity coating prepared in step 2 on the substrate with a spraying thickness of 100 μm, and let it cure naturally for 30 min until the surface is dry;

[0035] 4) Spray the high-emissivity coating (aerogel hollow glass microsphere heat-insulating waterborne coating) prepared in step 1 on the high-reflectivity coating with a spraying thickness of 2.0 mm, and let it cure naturally to obtain the radiation heat-insulating composite coating.

[0036] Example 4 (heat preservation)

[0037] 1) According to the method in Patent CN118185407B, put the acrylic resin emulsion, dispersant and deionized water into a stirring container, start the stirrer, and stir at a speed of 500 rpm for 5 minutes; add the film-forming aid (DB / ETB), aerogel slurry (previously stirred evenly with deionized water), and glass microspheres into the stirring container, start the stirrer, and stir at a speed of 1000 rpm for 10 - 15 minutes; add the thickener into the stirring container, start the stirrer, and stir at a speed of 1500 rpm for 10 minutes; the high-emissivity coating (aerogel hollow glass microsphere heat-insulating waterborne coating) prepared by the above method;

[0038] 2) Place the aqueous resin emulsion, dispersant, wetting agent, film-forming aid, leveling agent, defoaming agent and deionized water in a stirring container, start the stirrer, and stir at a speed of 500 rpm for 5 minutes; ② Add aluminum powder to the stirring container, start the stirrer, and stir at a speed of 1000 rpm for 10 minutes; ③ Add the cellulose thickener to the stirring container, start the stirrer and stir at a speed of 1000 rpm for 10 - 15 minutes; ④ Add the defoaming agent again, start the stirrer and stir at a speed of 1000 rpm for 5 minutes. A high reflectivity coating is prepared.

[0039] 3) Spray the high emissivity coating (aerogel hollow glass microsphere heat-insulating aqueous coating) prepared in step 1 on the substrate, with a spraying thickness of 2.0 mm, and cure naturally to obtain a radiation heat-insulating composite coating.

[0040] 4) Spray the high reflectivity coating prepared in step 2 on the high emissivity coating, with a spraying thickness of 100 μm, and cure naturally for 30 min until its surface is dry;

[0041] Comparative Example 1 (cold insulation)

[0042] 1) According to the method in Patent CN118185407B, place the acrylic resin emulsion, dispersant and deionized water in a stirring container, start the stirrer, and stir at a speed of 500 rpm for 5 minutes; Add the film-forming aid (DB / ETB), aerogel slurry (previously stirred evenly with deionized water), and glass microspheres to the stirring container, start the stirrer, and stir at a speed of 1000 rpm for 10 - 15 minutes; Add the thickener to the stirring container, start the stirrer, and stir at a speed of 1500 rpm for 10 minutes; The high emissivity coating (aerogel hollow glass microsphere heat-insulating aqueous coating) prepared by the above method;

[0043] 2) Place the aqueous resin emulsion, dispersant, wetting agent, film-forming aid, leveling agent, defoaming agent and deionized water in a stirring container, start the stirrer, and stir at a speed of 500 rpm for 5 minutes; ② Add aluminum powder to the stirring container, start the stirrer, and stir at a speed of 1000 rpm for 10 minutes; ③ Add the cellulose thickener to the stirring container, start the stirrer and stir at a speed of 1000 rpm for 10 - 15 minutes; ④ Add the defoaming agent again, start the stirrer and stir at a speed of 1000 rpm for 5 minutes to obtain a high reflectivity coating.

[0044] 3) Spray the high reflectivity coating prepared in step 2 on the substrate, with a spraying thickness of 65 μm, and cure naturally for 30 min until it is completely cured.

[0045] Comparative Example 2 (cold insulation)

[0046] 1) According to the method in Patent CN118185407B, put acrylic resin emulsion, dispersant and deionized water into a stirring container, start the stirrer, adjust the speed to 500 rpm and stir for 5 minutes; add film-forming aid (DB / ETB), aerogel slurry (previously stirred evenly with deionized water), and glass microspheres into the stirring container, start the stirrer, adjust the speed to 1000 rpm and stir for 10 - 15 minutes; add thickener into the stirring container, start the stirrer, adjust the speed to 1500 rpm and stir for 10 minutes; obtain a high emissivity coating (aerogel hollow glass microsphere heat-insulating waterborne coating) by the above method;

[0047] 2) Put aqueous resin emulsion, dispersant, wetting agent, film-forming aid, leveling agent, defoaming agent and deionized water into a stirring container, start the stirrer, adjust the speed to 500 rpm and stir for 5 minutes; ② add aluminum powder into the stirring container, start the stirrer, adjust the speed to 1000 rpm and stir for 10 minutes; ③ add cellulose thickener into the stirring container, start the stirrer at 1000 rpm and stir for 10 - 15 minutes; ④ add defoaming agent again, start the stirrer at 1000 rpm and stir for 5 minutes. Obtain a high reflectivity coating.

[0048] 3) Spray the high emissivity coating (aerogel hollow glass microsphere heat-insulating waterborne coating) prepared in step 1 on the substrate, with a spraying thickness of 3.0 mm, and cure naturally to obtain a coating.

[0049] Comparative Example 3 (cold insulation)

[0050] 1) According to the method in Patent CN118185407B, put acrylic resin emulsion, dispersant and deionized water into a stirring container, start the stirrer, adjust the speed to 500 rpm and stir for 5 minutes; add film-forming aid (DB / ETB), aerogel slurry (previously stirred evenly with deionized water), and glass microspheres into the stirring container, start the stirrer, adjust the speed to 1000 rpm and stir for 10 - 15 minutes; add thickener into the stirring container, start the stirrer, adjust the speed to 1500 rpm and stir for 10 minutes; obtain a high emissivity coating (aerogel hollow glass microsphere heat-insulating waterborne coating) by the above method;

[0051] 2) Put aqueous resin emulsion, dispersant, wetting agent, film-forming aid, leveling agent, defoaming agent and deionized water into a stirring container, start the stirrer, adjust the speed to 500 rpm and stir for 5 minutes; ② add aluminum powder into the stirring container, start the stirrer, adjust the speed to 1000 rpm and stir for 10 minutes; ③ add cellulose thickener into the stirring container, start the stirrer at 1000 rpm and stir for 10 - 15 minutes; ④ add defoaming agent again, start the stirrer at 1000 rpm and stir for 5 minutes. Obtain a high reflectivity coating.

[0052] 3) Spray the high-reflectivity coating prepared in step 2 on the substrate with a spraying thickness of 10 μm, and let it cure naturally for 30 min until the surface is dry.

[0053] 4) Spray the high-emissivity coating (aerogel hollow glass microsphere heat-insulating waterborne coating) prepared in step 1 on the high-reflectivity coating with a spraying thickness of 0.2 mm, and let it cure naturally to obtain a radiation heat-insulating composite coating.

[0054] Comparative Example 4 (cold insulation)

[0055] 1) According to the method in Patent CN118185407B, put acrylic resin emulsion, dispersant and deionized water into a stirring container, start the stirrer, adjust the speed to 500 rpm and stir for 5 minutes; put the film-forming aid (DB / ETB), aerogel slurry (previously stirred evenly with deionized water), and glass microspheres into the stirring container, start the stirrer, adjust the speed to 1000 rpm and stir for 10 - 15 minutes; put the thickener into the stirring container, start the stirrer, adjust the speed to 1500 rpm and stir for 10 minutes; the high-emissivity coating (aerogel hollow glass microsphere heat-insulating waterborne coating) prepared by the above method.

[0056] 2) Spray other high-reflectivity coatings (silver paint type) on the substrate with a spraying thickness of 65 μm, and let it cure naturally for 30 min until the surface is dry.

[0057] 3) Spray the high-emissivity coating (aerogel hollow glass microsphere heat-insulating waterborne coating) prepared in step 1 on the substrate with a spraying thickness of 3.0 mm, and let it cure naturally to obtain a radiation heat-insulating composite coating.

[0058] Comparative Example 5 (cold insulation)

[0059] 1) Put waterborne resin emulsion, dispersant, wetting agent, film-forming aid, leveling agent, defoaming agent and deionized water into a stirring container, start the stirrer, adjust the speed to 500 rpm and stir for 5 minutes; ② Put aluminum powder into the stirring container, start the stirrer, adjust the speed to 1000 rpm and stir for 10 minutes; ③ Put cellulose thickener into the stirring container, start the stirrer at 1000 rpm and stir for 10 - 15 minutes; ④ Add the defoaming agent again, start the stirrer at 1000 rpm and stir for 5 minutes. Obtain a high-reflectivity coating.

[0060] 2) Spray the high-reflectivity coating prepared in step 1 on the substrate with a spraying thickness of 65 μm, and let it cure naturally for 30 min until the surface is dry.

[0061] 3) Spray high-emissivity coatings of other brands (graphene type) on the high-reflectivity coating with a thickness of 3.0 mm, and let it cure naturally to obtain a radiation heat-insulating composite coating.

[0062] Comparative Example 6 (cold insulation)

[0063] 1) Spray other high - reflectivity coatings on the substrate with a spraying thickness of 65 μm, and let it cure naturally for 30 min until the surface is dry.

[0064] 2) Spray high - emissivity coatings of other brands on the high - reflectivity coating with a spraying thickness of 3.0 mm, and let it cure naturally to obtain a radiation - heat - insulating composite coating.

[0065] Comparative Example 7 (heat insulation)

[0066] 1) According to the method in Patent CN118185407B, put acrylic resin emulsion, dispersant and deionized water into a stirring container, turn on the stirrer, adjust the speed to 500 rpm and stir for 5 minutes; add film - forming auxiliaries (DB / ETB), aerogel slurry (stirred evenly with deionized water in advance), and glass microspheres into the stirring container, turn on the stirrer, adjust the speed to 1000 rpm and stir for 10 - 15 minutes; add thickener into the stirring container, turn on the stirrer, adjust the speed to 1500 rpm and stir for 10 minutes; obtain high - emissivity coatings (aerogel hollow glass microsphere heat - insulating water - borne coatings) by the above method.

[0067] 2) Put water - borne resin emulsion, dispersant, wetting agent, film - forming auxiliaries, leveling agent, defoaming agent and deionized water into a stirring container, turn on the stirrer, adjust the speed to 500 rpm and stir for 5 minutes; ② Add aluminum powder into the stirring container, turn on the stirrer, adjust the speed to 1000 rpm and stir for 10 minutes; ③ Add cellulose thickener into the stirring container, turn on the stirrer at 1000 rpm and stir for 10 - 15 minutes; ④ Add defoaming agent again, turn on the stirrer at 1000 rpm and stir for 5 minutes. Obtain high - reflectivity coatings.

[0068] 3) Spray the high - emissivity coatings (aerogel hollow glass microsphere heat - insulating water - borne coatings) prepared in step 1 on the substrate with a spraying thickness of 0.1 mm, and wait for it to cure completely.

[0069] 4) Spray the high - reflectivity coatings prepared in step 2 on the high - reflectivity coating with a spraying thickness of 10 μm, and let it cure naturally until it cures completely; obtain a radiation - heat - insulating composite coating.

[0070] Comparative Example 8 (heat insulation)

[0071] 1) According to the method in Patent CN118185407B, put the acrylic resin emulsion, dispersant and deionized water into a stirring container, start the stirrer, adjust the speed to 500 rpm and stir for 5 minutes; add the film-forming aid (DB / ETB), aerogel slurry (previously stirred evenly with deionized water), and glass microspheres into the stirring container, start the stirrer, adjust the speed to 1000 rpm and stir for 10 - 15 minutes; add the thickener into the stirring container, start the stirrer, adjust the speed to 1500 rpm and stir for 10 minutes; obtain the high emissivity coating (aerogel hollow glass microsphere heat-insulating waterborne coating) by the above method;

[0072] 2) Spray the high emissivity coating (aerogel hollow glass microsphere heat-insulating waterborne coating) prepared in step 1 on the substrate, with a spraying thickness of 3.0 mm, and cure naturally to obtain the coating.

[0073] Comparative Example 9 (thermal insulation)

[0074] 1) Put the waterborne resin emulsion, dispersant, wetting agent, film-forming aid, leveling agent, defoaming agent and deionized water into a stirring container, start the stirrer, adjust the speed to 500 rpm and stir for 5 minutes; ② Add aluminum powder into the stirring container, start the stirrer, adjust the speed to 1000 rpm and stir for 10 minutes; ③ Add cellulose thickener into the stirring container, start the stirrer at 1000 rpm and stir for 10 - 15 minutes; ④ Add the defoaming agent again, start the stirrer at 1000 rpm and stir for 5 minutes. Obtain the high reflectivity coating.

[0075] 2) Spray the high reflectivity coating prepared in step 2 on the substrate, with a spraying thickness of 65 μm, and cure naturally until it is completely cured to obtain the coating.

[0076] Comparative Example 10 (thermal insulation)

[0077] 1) Put the waterborne resin emulsion, dispersant, wetting agent, film-forming aid, leveling agent, defoaming agent and deionized water into a stirring container, start the stirrer, adjust the speed to 500 rpm and stir for 5 minutes; ② Add aluminum powder into the stirring container, start the stirrer, adjust the speed to 1000 rpm and stir for 10 minutes; ③ Add cellulose thickener into the stirring container, start the stirrer at 1000 rpm and stir for 10 - 15 minutes; ④ Add the defoaming agent again, start the stirrer at 1000 rpm and stir for 5 minutes. Obtain the high reflectivity coating.

[0078] 2) Spray other high emissivity coatings on the substrate, with a spraying thickness of 3.0 mm, and wait until it is completely cured

[0079] 3) Spray the high reflectivity coating prepared in step 2 on the high reflectivity coating, with a spraying thickness of 65 μm, and cure naturally until it is completely cured; obtain the radiation heat-insulating composite coating.

[0080] Comparative Example 11 (Thermal Insulation)

[0081] 1) According to the method in Patent CN118185407B, put acrylic resin emulsion, dispersant and deionized water into a stirring container, start the stirrer, adjust the speed to 500 rpm and stir for 5 minutes; add film-forming aid (DB / ETB), aerogel slurry (previously stirred evenly with deionized water), and glass microspheres into the stirring container, start the stirrer, adjust the speed to 1000 rpm and stir for 10 - 15 minutes; add thickener into the stirring container, start the stirrer, adjust the speed to 1500 rpm and stir for 10 minutes; obtain a high emissivity coating (aerogel hollow glass microsphere heat-insulating waterborne coating) by the above method;

[0082] 2) Spray the high emissivity coating (aerogel hollow glass microsphere heat-insulating waterborne coating) prepared in step 1 on the substrate, with a spraying thickness of 3.0 mm, and wait for it to fully cure

[0083] 3) Spray other high reflectivity coatings on the high emissivity coating, with a spraying thickness of 65 μm, and let it cure naturally until it is fully cured; obtain a radiation heat-insulating composite coating.

[0084] Comparative Example 12 (Thermal Insulation)

[0085] 1) Spray other high emissivity coatings on the substrate, with a spraying thickness of 3.0 mm, and wait for it to fully cure

[0086] 2) Spray other high reflectivity coatings on the high reflectivity coating, with a spraying thickness of 65 μm, and let it cure naturally until it is fully cured; obtain a radiation heat-insulating composite coating.

[0087] Conduct experiments on the above cases

[0088] First, prepare adjacent high-temperature and low-temperature chambers (as Figure 3 shown), and place the thermal resistance test samples made from the above cases between the high-temperature and low-temperature chambers.

[0089] Test method reference: GB / T 13475-2008 "Determination of Steady-State Heat Transfer Properties Calibration and Guarded-Hot-Box Method" and the additional thermal resistance test method in the Shanghai local standard.

[0090] According to the national standard "Determination of Steady-State Heat Transfer Properties Calibration and Guarded-Hot-Box Method" GB / T13475-2008, measure the heat transfer coefficient K of the test base wall and the heat transfer coefficient K between the test base material and the heat radiation barrier coating respectively, convert them into thermal resistance, and take the difference between the two thermal resistances as the additional thermal resistance of the heat radiation barrier coating. The calculation formula is as follows:

[0091]

[0092] Where: R ------ Thermal resistance of the thermal radiation barrier coating (m 2 ·K / W);

[0093] K0 ------ Heat transfer coefficient of the test substrate [W / (m·K)];

[0094] K ------ Heat transfer coefficient of the test substrate and the thermal radiation barrier coating [W / (m·K)].

[0095] The test results are as follows:

[0096]

[0097]

[0098] In addition, under different conditions of actual application of automotive battery packs, a temperature difference experiment

[0099] 1. Place the battery pack in an environment of 25°C for 12 - 24 h to ensure that the temperature is 25°C (±2°C).

[0100] 2. Start recording data. Set the constant temperature oven to 0°C, and then set the temperature to -30°C after putting the battery pack into the oven.

[0101] 3. Keep the environmental temperature at -30°C for more than 12 h, then turn off the constant temperature oven to obtain the original data without a high-emissivity coating.

[0102] 4. Spray a high-emissivity coating (except for the electrode surface) on the outer shell of the battery pack, measure the hardness after natural curing, and confirm complete curing.

[0103] 5. Repeat steps 1 - 3 for the treated battery pack to obtain the original data with a high-emissivity coating.

[0104] 6. Shield the air vents and repeat steps 1 - 3 to obtain the original data to avoid direct blowing.

[0105] 7. Brush a layer of high-reflectivity topcoat on the outer surface of the high-emissivity coating of the battery pack, and repeat steps 1 - 3 to obtain the original data with a high-reflectivity coating (at this time, the air vents have been shielded).

[0106] 8. Data processing and analysis.

[0107] The test results are as follows:

[0108]

[0109]

[0110] And plot the above test results as a surface graph, as Figure 4As shown, the following can be obtained from the above test results:

[0111] 1. The thermal insulation material has an obvious improvement effect on the temperature reduction process of the battery pack.

[0112] 2. During the test, the low-temperature air in the air outlet should be prevented from directly blowing on the battery pack.

[0113] 3. Brushing a layer of reflective topcoat on the outside of the thermal insulation material can further improve the thermal insulation performance.

[0114] It should be noted that in this article, the term "including", "comprising" or any other variant thereof is intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements not only includes those elements, but also includes other elements not expressly listed, or further includes elements inherent to such process, method, article or device.

[0115] In this article, specific examples are used to elaborate on the principles and implementation manners of the present invention. The description of the above examples is only used to help understand the method and its core idea of the present invention. The above is only the preferred implementation manner of the present invention. It should be pointed out that due to the limited nature of written expression and the objectively infinite specific structures, for those of ordinary skill in the art, without departing from the principle of the present invention, several improvements, refinements or changes can be made, or the above technical features can be combined in an appropriate manner; these improvements, refinements, changes or combinations, or directly applying the concept and technical solution of the invention to other occasions without improvement, shall all be regarded as the protection scope of the present invention.

Claims

1. A new type of radiation heat-insulating composite coating, characterized in that, It includes a far-infrared band high-emissivity coating with a thickness of 0.5 - 5 mm and a high-reflectivity coating in this band, and the thickness of the high-reflectivity coating is 30 μm - 100 μm.

2. The novel radiation heat-insulating composite coating according to claim 1, wherein The far-infrared band is specifically the 3 - 14 μm band.

3. A novel radiation heat-insulating composite coating according to claim 1, characterized in that, The high-reflectivity coating includes the following components: waterborne resin, water, dispersant, wetting agent, defoamer, film-forming aid, aluminum powder, leveling agent, and cellulose thickener.

4. A novel radiation heat-insulating composite coating according to claim 3, characterized in that, The waterborne resin is 50%, water is 35.3%, dispersant is 1%, wetting agent is 0.5%, defoamer is 0.2%, film-forming aid is 2%, aluminum powder is 10%, leveling agent is 0.5%, and cellulose thickener is 0.5%.

5. A novel radiation heat-insulating composite coating according to claim 3 or 4, characterized in that, The aluminum powder is alumina powder, with a particle size between 10 - 70 μm, and the effect is best when it is 50 - 70 μm.

6. A novel radiation heat-insulating composite coating according to claim 3 or 4, characterized in that The resin is polyurethane resin, epoxy resin, alkyd resin, acrylic resin, and their modified resins.

7. A novel radiation heat-insulating composite coating according to claim 3 or 4, characterized in that The high-reflectivity coating can be prepared by the following steps: ① Place the waterborne resin emulsion, dispersant, wetting agent, film-forming aid, leveling agent, defoamer, and deionized water in a stirring container, start the stirrer, and adjust the speed to 500 rpm and stir for 5 minutes; ② Add the aluminum powder to the stirring container, start the stirrer, and adjust the speed to 1000 rpm and stir for 10 minutes; ③ Add the cellulose thickener to the stirring container, start the stirrer at 1000 rpm and stir for 10 - 15 minutes; ④ Add the defoamer again, start the stirrer at 1000 rpm and stir for 5 minutes.

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