Highly infrared-reflective heat-insulating dual-layer colored paint layer structure, and highly infrared-reflective heat-insulating coating system and use thereof

Abstract

The present invention relates to a highly infrared-reflective heat-insulating dual-layer colored paint layer structure, comprising a first colored paint layer and a second colored paint layer. The first colored paint layer is an enhanced infrared-reflective layer incorporating a flaky reflective pigment, and the second colored paint layer is a black-appearance coating layer having high infrared transmittance. A first colored paint used in the first colored paint layer and a second colored paint used in the second colored paint layer are both mixtures containing an acrylic resin and a polyurethane resin. The first colored paint layer has an infrared reflectivity of greater than 70%, and the second colored paint layer has an infrared transmittance of greater than 70%. The dual-layer colored paint layer structure, matched with a conventional primer layer and a clear coat layer, can exhibit strong weather resistance and excellent bright black appearance while achieving an infrared reflectivity of 70% or more, has significant reflection and cooling effects, and can be widely used in the fields of aircrafts, automobiles, intelligent devices, etc. The present invention further comprises a highly infrared-reflective heat-insulating coating system and a use thereof.

Description

A double-layer colored paint structure with high infrared reflectance and heat insulation, a high infrared reflectance and heat insulation coating system and its application Technical Field

[0001] This invention relates to the field of infrared reflective heat-insulating coatings, specifically to a double-layer colored paint structure with high infrared reflective heat insulation that can be used on various substrates such as carbon fiber composites, glass fiber composites, and plastics, as well as a high infrared reflective heat-insulating coating system and its application. Background Technology

[0002] Black is beloved for its sophisticated texture. Carbon black and iron oxides are the most commonly used pigments for black, but these pigments strongly absorb sunlight, causing a significant rise in the surface and internal temperature of the material. In hot summer weather, the surface temperature of a black car can reach 70 degrees Celsius. Excessive heat not only causes discomfort but also increases energy consumption and accelerates material aging. Carbon fiber composites are high-performance composite materials made from carbon fibers and resins through various molding processes. They possess properties such as low density, high strength, and high stiffness. Carbon fiber composites are widely used in aircraft, automobiles, rail transportation, and smart devices, and are currently one of the most popular lightweight materials. Carbon fiber surface coating has unique characteristics, such as complex and time-consuming processes, defects caused by fiber composites, requirements for low-temperature coating and high environmental protection standards, and applications in emerging high-end fields, demanding higher quality coating surfaces.

[0003] In existing technologies, the main mechanism for achieving heat insulation is to reduce the accumulated heat in materials by highly reflecting sunlight. For example, heat-insulating skylights often use magnetron sputtering technology to deposit nano-metal layers, reflecting ultraviolet and near-infrared light in the solar spectrum; reflective heat-insulating films use nano-coating technology to prepare multi-layered nano-layers with alternating refractive indices, reflecting near-infrared light. However, the above-mentioned technologies are difficult to apply to coatings, and using reflective pigments often requires thick coatings and results in poor appearance. Patent US20040191540A1 describes a dual-coating system that coats a reflective metal substrate with infrared-transparent black pyrene pigment, achieving approximately 30-50% infrared reflectivity, thereby reducing the sample temperature. Patent WO2010030970A3 describes an aqueous dual-coating system based on acrylic emulsion and flake silicate. It uses titanium dioxide, aluminum pigment, or a mixture of these with metal oxides as the first reflective layer, and pyrene black pigment as the second layer. This system can achieve a temperature reduction of approximately 7 degrees Celsius, but its reflectivity, color, and other technical characteristics are not disclosed. Patent WO2011056564A3 describes a coating that mixes infrared reflective pigments and infrared transparent pigments. Its purpose is to match the color of an improved coating, but it exhibits low reflectivity on a black substrate.

[0004] In summary, there is an urgent need in this field to develop a double-layer colored paint structure with high infrared reflectivity and heat insulation to solve the problems existing in the prior art. Summary of the Invention

[0005] Based on the above facts, the purpose of this invention is to provide a high infrared reflectance and heat insulation double-layer paint structure, wherein the first paint layer has an infrared reflectance of more than 70% and the second paint layer has an infrared transmittance of more than 70%; this double-layer paint structure, combined with a conventional primer layer and a clear coat layer, can achieve an infrared reflectance of more than 70% while having strong weather resistance and an excellent glossy black appearance, and achieves a significant reflective cooling effect.

[0006] The first aspect of the present invention provides a high infrared reflectance heat insulation double-layer paint structure, including a first paint layer and a second paint layer. The first paint layer is an enhanced infrared reflective layer with added flake reflective pigments, and the second paint layer is a black coating with high infrared transmittance. The first paint used in the first paint layer and the second paint used in the second paint layer are both mixtures containing acrylic resin and polyurethane resin.

[0007] First Color Paint

[0008] In some embodiments of the present invention, the first paint comprises, by weight percentage:

[0009] The total content of all the above components is 100%.

[0010] The preparation steps of the first color paint include: opening the stirring tank, adding solvent, acrylic resin, polyurethane resin, infrared reflective color paste, infrared transparent color paste, wetting and leveling agent, defoamer, and thickener to the stirring tank in sequence, and stirring until fully mixed; adjusting the pH to 7.5-8.5 with a pH adjuster to obtain the first color paint.

[0011] Second color paint

[0012] In some embodiments of the present invention, the second paint comprises, by weight percentage:

[0013] The total content of all the above components is 100%.

[0014] The preparation steps of the second color paint include: opening the mixing tank, adding solvent, acrylic resin, polyurethane resin, infrared transparent pigment, wetting and leveling agent, defoamer and thickener in sequence to the mixing tank, and stirring until fully mixed; adjusting the pH to 7.5-8.5 with pH adjuster to obtain the second color paint.

[0015] acrylic resin

[0016] In this invention, the acrylic resin contained in the first and second color paints is selected from water-based acrylic emulsions, polyester-modified acrylic emulsions, or polyurethane-modified acrylic emulsions. Preferably, the acrylic resin has a hydroxyl content of 0-3%, a solid content of 20-50%, a glass transition temperature (Tg) > 25°C, a minimum film-forming temperature (MFTT) > 25°C, is basically transparent in the near-infrared range of 780nm-2500nm, and has essentially no effect on the reflectivity or transmittance of infrared light, thus requiring no curing agent.

[0017] Specifically, the acrylic resin is selected from one or more of the following acrylic resins: SETAQUA@6801 and SETAQUA@6802 provided by Zhanxin Resin Co., Ltd.; Bayhydrol@A2846, Bayhydrol@A2474, Bayhydrol@A2457, Bayhydrol@A2856xp, and Bayhydrol@A2469 provided by Covestro Resin Co., Ltd.; WD-594 and WD-588 provided by DIC Resin Co., Ltd.; and Joncryl@8330AP, Joncryl@8111AP, Joncryl@HYB 6336, Joncryl@HYB 6340, and Joncryl@HYB 6345AP provided by BASF Resin Co., Ltd.

[0018] polyurethane resin

[0019] In this invention, the polyurethane resin in both the first and second color paints is selected from waterborne polyurethane dispersions, acrylic-modified polyurethane dispersions, aliphatic-modified polyurethane dispersions, and polyester-modified polyurethane dispersions. Preferably, the polyurethane resin does not contain hydroxyl groups, has a solid content of 20-50%, a glass transition temperature (Tg) < 0°C, a minimum film-forming temperature (MFTT) < 5°C, is essentially transparent in the near-infrared range of 780nm-2500nm, and has virtually no effect on infrared reflectivity or transmittance, thus requiring no curing agent.

[0020] Specifically, the polyurethane resin is selected from one or more of the following polyurethane resins: Joncryl@U 4190, Joncryl@U5168, and Joncryl@U 4199AP provided by BASF; WATERSOL UD-5002 and WATERSOL UD-8801 provided by DIC Resins; Bayhydrol@UH2648, Bayhydrol@UH2648 / 1, Bayhydrol@UH2606, Bayhydrol@UH2952, and Bayhydrol@UA2856 provided by Covestro; and DAOTAN VTW6460, DAOTAN VTW6462, and DAOTAN VTW6464 provided by Zhanxin Resins.

[0021] Infrared reflective pigment

[0022] In this invention, the infrared reflective pigment paste is a pigment paste with reflective properties in the range of 780nm-2500nm, selected from aluminum silver paste dispersion, black pigment dispersion, or white pigment dispersion. Preferably, the infrared reflective pigment paste is an aluminum silver paste dispersion, by weight...

[0023] The aluminum silver paste dispersion comprises:

[0024] 5-15 parts deionized water

[0025] Dispersant 0.1-1 part

[0026] 2-7 parts aluminum silver paste

[0027] The preparation steps of the aluminum silver paste dispersion include: mixing deionized water, dispersant and aluminum silver paste evenly, and letting it stand for 1.5-3 hours to obtain the aluminum silver paste dispersion.

[0028] The black pigment dispersion or the white pigment dispersion comprises:

[0029] The preparation steps of the black pigment dispersion or white pigment dispersion include: mixing and stirring deionized water, dispersant, and black or white pigment evenly, adjusting the pH to 7.5-8.5 with a pH adjuster, and then milling for 1-2 hours until the fineness is less than 10 μm to obtain the black pigment dispersion or white pigment dispersion.

[0030] Preferably, the aluminum silver paste is a flake-shaped aluminum pigment coated with resin or silicon oxide, the black pigment is a black reflective pigment with infrared reflective effect, and the white pigment is titanium dioxide with infrared reflective effect; more preferably, the aluminum silver paste is a water-based aluminum pigment coated with silicon dioxide, which has a silver dollar-shaped or irregular flake structure, a particle size of 5-50 μm, and a thickness of 30-500 nm.

[0031] Specifically, the titanium dioxide is selected from one or more of the following titanium dioxide products: Altiris 800 and Altiris 550 provided by Pan-Energy Technology Co., Ltd., and TIPAQUE PFR404 provided by Ishihara S.A. Co., Ltd.; the black pigment is selected from one or more of the following black pigment products: BLACK 30C941, BLACK 10P950, BLACK 10G996, and BLACK 10C909 provided by Schott Co., Ltd., and SG-101 provided by Ishihara S.A. Co., Ltd.; the aluminum silver paste is selected from the following aluminum silver paste products: STAPA HYDROLAN series 2153, 2154, 2156, 2197, S408, and S422 provided by Aika Co., Ltd., HYDROSHINE WS series 3001 and 3004, METALURE series 1006 provided by Aika Co., Ltd., and SBC AQ provided by Starlink Co., Ltd. One or more of the J series aluminum silver pastes of models 6713, 6718, 6812, and 6834; the dispersant is selected from one or more of the dispersants provided by BYK Company of models 190, 192, 180, 2012, and 2014, and the Dispex series ULTRAPX 4550, 4522, 4525, and 4575 provided by BASF.

[0032] Infrared transparent color paste

[0033] In this invention, the infrared transparent color paste comprises one or more dispersions of different colors, and by weight, the dispersions comprise:

[0034] The preparation steps of the dispersion include: mixing and stirring deionized water, dispersant, dispersing resin, and pigment for 20-40 minutes; adjusting the pH to 7.5-8.5 with a pH adjuster; and then milling for 1-3 hours until the fineness is less than 10 μm, thus obtaining the dispersion for the infrared transparent color paste. It should be noted that this dispersion is actually also a color paste, but it is called a dispersion to distinguish it from the infrared transparent color paste and avoid confusion.

[0035] The pigments are selected from one or more of a variety of pigments, including but not limited to indigo anthraquinone, copper phthalocyanine blue pigments, YInMn indium manganese blue, perylene black pigments, perylene red pigments, non-masking DPP red pigments, quinacridone red pigments, quinophthalone pigments, isoindolinone pigments, and benzimidazolone-based yellow-orange pigments.

[0036] Specifically, the red pigment is selected from one or more of the red pigments provided by BASF, Germany, namely Paliogen@Red L3850, Paliogen@Red L3875, Paliogen@Red L3885, and Paliogen@Red L4045; the yellow pigment is selected from one or more of the yellow pigments provided by BASF, Germany, namely Paliotol@Yellow L0962, Paliotol@Yellow L0960, Paliotol@Yellow L1155, Sicopal@Yellow L1130, Sicopal@Yellow L1100, and Sicopal@Yellow L1635; the blue pigment is selected from one or more of the blue pigments provided by BASF, Germany, namely Heliogen@Blue L7085, Heliogen@Blue L6975, Heliogen@Blue L6930, and Heliogen@Blue L7081; and the black pigment is selected from the Paliogen@Black pigment provided by BASF, Germany. The black pigments L0086 and Paliogen@Black L0095, or a combination thereof, are used. The dispersion resin is selected from SETAL@6303 resin from ZNTech, Joncryl@62J from BASF, and ACW-1011 from Nippon Paint Motor Co., Ltd., with SETAL@6303 resin from ZNTech being preferred.

[0037] In a specific embodiment, the infrared transparent pigment in the first paint can be a dispersion of one color; it can also be a mixture of dispersions of multiple different colors; or it can be a mixture of dispersions of multiple different colors with a small amount of black pigment dispersion, wherein the black pigment dispersion can be the black pigment dispersion for preparing infrared reflective pigment as described above, and the amount of the black pigment dispersion added is 1-6 wt%, preferably 1-2 wt%; the infrared transparent pigment in the second paint is a black infrared transparent pigment, which can be a black dispersion, or a black infrared transparent pigment composed of a mixture of dispersions of multiple different colors, or it can be a mixture of dispersions of multiple different colors with a small amount of black pigment dispersion, wherein the black pigment dispersion can be the black pigment dispersion for preparing infrared reflective pigment as described above, and the amount of the black pigment dispersion added is 1-6 wt%, preferably 1-2 wt%.

[0038] Wetting and leveling agents

[0039] In some embodiments of the present invention, the wetting and leveling agent is selected from one or more of the wetting and leveling agents provided by BYK Company with models 347, 349, 3451, 381, 3560, and 3455, and the hydropalat@WE series 3179, 3189, 3220, 3225, and 3229 provided by BASF Company.

[0040] Defoamer

[0041] In some embodiments of the present invention, the defoamer is selected from one or more of the defoamers provided by BYK Company with model numbers 011, 024, 015, 028, and 1710, and the Foamaster series defoamers provided by BASF with model numbers SI2281, SI2210, and SI2299.

[0042] Thickener

[0043] In some embodiments of the present invention, the thickener is selected from one or more of the following thickeners: BYK (AQUATIX 8421, LAPONITE-RD, RHEOBYK-440, RHEOBYK-7420), and BASF (Rheovis series HS1212, HS1303, AS1130, AS1189, PU1235, PU1250). Specifically, LAPONITE-RD is pre-dispersed in an aqueous solution for use; for example, LAPONITE-RD is pre-dispersed in a 3% aqueous solution for use.

[0044] pH adjuster

[0045] In some embodiments of the present invention, the pH adjuster is an aqueous solution of dimethylethanolamine (DMEA), specifically, for example, a 10% aqueous solution of dimethylethanolamine is selected as the pH adjuster.

[0046] solvent

[0047] In some embodiments of the present invention, the solvent includes deionized water and a film-forming solvent added in an amount not exceeding 10%, wherein the mass percentage of the film-forming solvent may be, for example, 0-5% or 5-10%. The film-forming solvent is selected from one or more of isooctanol, isopropanol, propylene glycol, propylene glycol butyl ether, dipropylene glycol butyl ether, ethylene glycol butyl ether, diethylene glycol butyl ether, propylene glycol methyl ether, dipropylene glycol methyl ether acetate, ethylene glycol ethyl ether, diethylene glycol ethyl ether, and alcohol ester twelve.

[0048] A second aspect of the present invention provides a high infrared reflectance heat-insulating coating system, comprising a clear varnish layer, a second color paint layer, a first color paint layer, and a primer layer; the clear varnish used in the clear varnish layer is an isocyanate-cured hydroxyl acrylic resin composition; the primer used in the primer layer is a high-solids-content isocyanate-cured polyamine resin two-component coating composition; the first color paint layer is an enhanced infrared reflective layer with added flake reflective pigments, and the second color paint layer is a black coating with high infrared transmittance; both the first color paint used in the first color paint layer and the second color paint used in the second color paint layer are mixtures containing acrylic resin and polyurethane resin.

[0049] varnish

[0050] In this invention, the viscosity range of the varnish is 100-5000 mPa·s, and it is preferably Nippon Paint varnish of model C7900 provided by Nippon Paint.

[0051] primer

[0052] In this invention, the primer has a solid content greater than 70% and a viscosity range of 100-20000 mPa·s; preferably, it is Nippon primer model P7001 provided by Nippon Paint.

[0053] According to a preferred embodiment of the present invention, the preparation steps of the high infrared reflectance heat-insulating coating system include:

[0054] (1) Preparation of the first color paint:

[0055] Open the mixing tank and add the solvent, acrylic resin, polyurethane resin, infrared reflective pigment, infrared transparent pigment, wetting and leveling agent, defoamer, and thickener in sequence. Stir until fully mixed. Adjust the pH to 7.5-8.5 with a pH adjuster to obtain the first color paint.

[0056] (2) Preparation of the second color paint:

[0057] Open the mixing tank and add the solvent, acrylic resin, polyurethane resin, infrared transparent pigment, wetting and leveling agent, defoamer, and thickener in sequence. Stir until fully mixed. Adjust the pH to 7.5-8.5 with a pH adjuster to obtain the second color paint.

[0058] (3) Spray the first color paint on the surface of the primer layer (4) and flash dry at 60-80℃ for 5-10 minutes to obtain the first color paint layer (3); continue to spray the second color paint on the surface of the first color paint layer (3) and dry at 60-80℃ for 10-30 minutes to obtain the second color paint layer (2); spray the clear varnish layer (1) on the surface of the second color paint layer (2) and cure at 60-100℃ for 30-120 minutes to obtain the high infrared reflection heat insulation coating system.

[0059] The third aspect of the present invention provides applications of the high infrared reflectance heat-insulating coating system described in the second aspect of the present invention, including applications in aircraft, automobiles, smart devices and other fields.

[0060] Beneficial effects of the present invention

[0061] This invention provides a high infrared reflectance heat insulation double-layer paint structure. The first paint layer has an infrared reflectance greater than 70%, and the second paint layer has an infrared transmittance greater than 70%. This double-layer paint structure, combined with a conventional primer and clear coat layer, achieves an infrared reflectance of over 70% while maintaining strong weather resistance and an excellent glossy black appearance, resulting in a significant reflective cooling effect. It can be widely applied in aircraft, automobiles, smart devices, and other fields. The high infrared reflectance heat insulation coating system formed by applying this high infrared reflectance heat insulation double-layer paint structure can be used on various substrates such as carbon fiber composites, glass fiber composites, and plastics, and is particularly suitable for carbon fiber composites. It exhibits excellent adhesion and environmental friendliness. The spraying process is simple and can be completed at low temperatures (≤80℃), saving costs. Attached Figure Description

[0062] Figure 1 is a schematic diagram of the double-layer colored paint structure with high infrared reflectance and heat insulation according to the present invention.

[0063] Figure 2 is a schematic diagram of the structure of the high infrared reflectance heat insulation coating system of the present invention coated on the substrate.

[0064] The labels in the diagram represent: 1. Clear coat; 2. Second coat; 3. First coat; 4. Primer; 5. Substrate. Detailed Implementation

[0065] To more clearly illustrate the present invention, the following description, in conjunction with specific embodiments and comparative examples, further clarifies the invention. Those skilled in the art should understand that the specific descriptions below are illustrative rather than restrictive and should not be construed as limiting the scope of protection of the present invention. Unless otherwise specified, the experimental methods used in the following embodiments and comparative examples are conventional methods, and the raw materials and reagents used are products that can be purchased from conventional commercial channels.

[0066] The above technical solution will be described below with reference to specific embodiments.

[0067] Preparation of infrared reflective pigments

[0068] Aluminum silver paste dispersions: STAPA HYDROLAN S408, HYDROSHINE WS 3001, METALURE 1006, and SBC AQ J6713 aluminum silver pastes were selected respectively. 10 parts deionized water, 0.5 parts BYK192, and 5 parts aluminum silver paste were mixed evenly at low speed and left to stand for 2 hours to prepare the STAPA HYDROLAN S408 dispersion, HYDROSHINE WS 3001 dispersion, METALURE 1006 dispersion, and SBC AQ J6713 dispersion.

[0069] Black or white pigment dispersions: Mix 30 parts deionized water, 9 parts BYK190, 1 part 10% DMEA solution, and 60 parts black or white pigment and stir for 30 minutes. Adjust the pH to 7.5-8.5 with a pH adjuster, then mill for 1-2 hours until the fineness is less than 10 μm. The selected black pigment is BLACK 30C941, and a BLACK 30C941 dispersion was prepared. The selected white pigments are Altiriris 800 and TIPAQUE PFR404, and Altiriris 800 and TIPAQUE PFR404 dispersions were prepared respectively.

[0070] Preparation of the first color paint without infrared transparent pigment

[0071] The first paint samples 1-10 without infrared transparent pigment were prepared according to Table 1.

[0072] Table 1 Formulation Table for Samples 1-10

[0073] The reflectance and transmittance of the first paint samples 1-10, which do not contain infrared transparent pigment, were measured:

[0074] Reflectivity sample preparation: Prepare a 15*10cm carbon fiber composite substrate, wipe the surface of the substrate clean with isopropanol, spray a 50μm thick P7001 primer, bake at 80℃ for 50min, then spray the first color paint composition of samples 1-10 with a thickness of 15μm, and bake at 80℃ for 20min.

[0075] Transmittance sample preparation: Prepare a 15*10cm transparent glass substrate, wipe the surface of the substrate clean with ethanol, directly spray a 15μm thick layer of the above sample 1-10 color paint composition (diluted with 25% deionized water), and bake at 80℃ for 20min.

[0076] After sample preparation, the ultraviolet-visible-near-infrared reflectance and transmittance were measured using a HITACHI U-4100 spectrometer. Covering power was determined using the black and white grid paper method. The results are summarized in Table 2 below.

[0077] Table 2 Test results for samples 1-10

[0078] As shown in Table 2 above, the samples using aluminum silver paste dispersion as infrared reflective pigment exhibit good infrared reflectivity on carbon fiber substrates, exceeding 80% at its highest. Samples using titanium dioxide pigment dispersion or black pigment dispersion as infrared reflective pigment exhibit certain infrared reflectivity, but their hiding power is limited, especially in the near-infrared range. Although the hiding power can be enhanced by increasing the coating thickness, excessively thick coatings limit their application, and the spraying process is complex and costly.

[0079] Preparation of dispersions for infrared black transparent pigment pastes

[0080] 69 parts deionized water, 10 parts BYK190, 1 part 10% DMEA solution, 5 parts SETAL@6303 resin (Zhanxin Company), and 15 parts pigment were mixed and stirred for 30 min. The pH was adjusted to 7.5-8.5 with a pH adjuster, and then milled for 1-3 h until the fineness was less than 10 μm to obtain various dispersions. The pigments used in each dispersion were Paliogen@Red L3850, Paliogen@Red L3875, Paliotol@Yellow L0962, Paliotol@Yellow L0960, Heliogen@Blue L7085, Heliogen@Blue L6975, and Paliogen@Black L0086, respectively, to prepare Paliogen@Red L3850 dispersion, Paliogen@Red L3875 dispersion, Paliotol@Yellow L0962 dispersion, Paliotol@Yellow L0960 dispersion, and Heliogen@Blue L0086 dispersion. L7085 dispersion, Heliogen@Blue L6975 dispersion, and Paliogen@Black L0086 dispersion.

[0081] Preparation of Infrared Black Transparent Pigment

[0082] Infrared black transparent pigment (BC) is prepared by mixing the ingredients according to the formula in Table 3.

[0083] Table 3 BC-1-6 Formulation Table

[0084] Preparation of the second color paint

[0085] Samples 11-18 of the second color paint were prepared according to Table 4.

[0086] Table 4 Formulation Table for Samples 11-18

[0087] It should be noted that AR 2000 BLACK color paste is a black paste containing carbon black pigment, not an infrared transparent color paste, and is not within the scope of protection of this invention. It is used as a control group in the examples.

[0088] Performance testing of the second color paint:

[0089] Sample preparation: Prepare a 15*10cm transparent glass substrate, wipe the surface of the substrate clean with ethanol, directly spray a 15μm thick paint composition of the above samples 11-18, and bake at 80℃ for 20min.

[0090] After sample preparation, the UV-Vis-NIR transmittance was measured using a HITACHI U-4100 spectrometer. Opacity was measured using the black and white grid paper method. Optical properties were measured using an Xrite-ci7800 colorimeter. The results are summarized in Table 5 below.

[0091] Table 5 Test results for samples 11-18

[0092] As shown in Table 5 above, the carbon black sample exhibits almost no infrared transmittance and strong absorption. The sample using the single-component dispersion of Paliogen@Black L0086 also demonstrates good black appearance and infrared transmittance, but its high price significantly increases costs. The sample using a transparent infrared black pigment paste composed of multiple dispersions exhibits excellent black appearance, while samples containing black Paliogen@Black L0086 dispersion or BLACK 30C941 dispersion show a deeper black color, with a richer black tone observed from multiple angles. However, BLACK 30C941 has a high infrared absorption rate, and adding more may reduce transmittance.

[0093] Preparation of the first color paint containing infrared transparent pigment

[0094] The first paint samples 19-27 containing infrared transparent pigment were prepared according to Table 6.

[0095] Table 6 Formulation Table for Samples 19-27

[0096] The test results for samples 19-27 are shown in Table 7 below.

[0097] Table 7 Test results for samples 19-27

[0098] As can be seen from the data in Table 7, adding infrared transparent pigment (mixed or single component) does not affect the reflectivity of the reflective layer, while adding black pigment containing carbon black pigment significantly reduces the reflectivity.

[0099] Preparation of coating samples in Examples 1-15 and Comparative Example 1

[0100] Reflective coating samples were prepared based on samples 1-27 above, as shown in Table 8 below, and the formulations are shown in Table 9 below. After the samples were prepared, they were left to stand for 48 hours before various tests were conducted. The infrared irradiation heating test was performed using a Phillips Infrared Lamp (100W) at a constant temperature of 25℃ in a laboratory with a distance of 20cm. The test results are shown in Tables 10 and 11.

[0101] Table 8 Production Method

[0102] Table 9 Formulations of Examples 1-15 and Comparative Example 1

[0103] Table 10. Test results of Examples 1-7 and Comparative Example 1

[0104] As shown in Table 10, Examples 1-7 and Comparative Example 1 demonstrate the influence of using different types of pigments in the first and second paints on the results. It can be seen that the carbon fiber substrate itself and the coating containing sample 11 (containing carbon black pigment) have strong heat absorption capacity. Examples 1-7 show that the effect of reflective cooling is positively correlated with infrared reflectivity.

[0105] Table 11 Detection results of Examples 8-15

[0106] As shown in Table 11 above, adding colored pigments (especially black pigments) to the first or second color paint will not affect the infrared reflectivity, but can deepen the black appearance to a certain extent.

[0107] The coating performance was further tested using the above-mentioned embodiments and comparative sample. The results are shown in Table 12. It can be seen that the coating of the present invention has excellent weather resistance.

[0108] Table 12 Coating performance test results

[0109] Further, the above embodiments and comparative samples were placed outdoors under sunlight for testing. The outdoor temperature was 20°C, the wind speed was about 6 m / s, and the height was about 2 m. An infrared thermometer was used to test the coating surface vertically at a distance of 2 cm. The results are shown in Table 13.

[0110] Table 13 Cooling Capacity Test Results

[0111] As can be seen from Table 13 above, the sample prepared by the present invention has a significant cooling capacity.

[0112] In summary, the high infrared reflectance heat insulation coating system of the present invention can achieve an infrared reflectivity of over 70% while possessing strong weather resistance and an excellent glossy black appearance, and can achieve a significant reflective cooling effect.

[0113] Obviously, the above embodiments of the present invention are merely examples for clearly illustrating the present invention, and are not intended to limit the implementation of the present invention. For those skilled in the art, other variations or modifications can be made based on the above description. It is impossible to exhaustively list all the implementation methods here. All obvious variations or modifications derived from the technical solutions of the present invention are still within the protection scope of the present invention.

Claims

1. A double-layer colored paint structure with high infrared reflectivity and heat insulation, characterized in that, It includes a first paint layer (3) and a second paint layer (2). The first paint layer (3) is an enhanced infrared reflective layer with added flake reflective pigments. The second paint layer (2) is a black coating with high infrared transmittance. The first paint used in the first paint layer (3) and the second paint used in the second paint layer (2) are both mixtures containing acrylic resin and polyurethane resin.

2. The high infrared reflectance heat insulation double-layer paint layer structure according to claim 1, characterized in that, The first paint, by weight percentage, comprises: The total content of all the above components is 100%.

3. The high infrared reflectance heat insulation double-layer paint layer structure according to claim 1, characterized in that, The second paint, by weight percentage, comprises: The total content of all the above components is 100%.

4. The high infrared reflectance heat insulation double-layer paint layer structure according to claim 2 or 3, characterized in that, The acrylic resin is selected from aqueous acrylic emulsion, polyester-modified acrylic emulsion, or polyurethane-modified acrylic emulsion. Preferably, the acrylic resin has a hydroxyl content of 0-3%, a solid content of 20-50%, a glass transition temperature (Tg) > 25°C, and a minimum film-forming temperature (MFTT) > 25°C. The polyurethane resin is selected from aqueous polyurethane dispersion, acrylic-modified polyurethane dispersion, aliphatic-modified polyurethane dispersion, or polyester-modified polyurethane dispersion. Preferably, the polyurethane resin does not contain hydroxyl groups, has a solid content of 20-50%, a glass transition temperature (Tg) < 0°C, and a minimum film-forming temperature (MFTT) < 5°C. The solvent includes deionized water and a film-forming solvent added in an amount not exceeding 10%. The film-forming solvent is selected from one or more of isooctanol, isopropanol, propylene glycol, propylene glycol butyl ether, dipropylene glycol butyl ether, ethylene glycol butyl ether, diethylene glycol butyl ether, propylene glycol methyl ether, dipropylene glycol methyl ether acetate, ethylene glycol ethyl ether, diethylene glycol ethyl ether, and twelfth alcohol ester.

5. The high infrared reflectance heat insulation double-layer paint layer structure according to claim 2 or 3, characterized in that, By weight, the infrared transparent pigment comprises one or more dispersions of different colors, the dispersions comprising: The pigment is selected from one or more of red pigments, yellow pigments, blue pigments, and black pigments, including but not limited to combinations of one or more of indigo anthraquinone, copper phthalocyanine blue pigments, YInMn indium manganese blue, perylene black pigments, perylene red pigments, non-masking DPP red pigments, quinacridone red pigments, quinophthalone pigments, isoindolyl yellow pigments, and benzimidazolone yellow-orange pigments.

6. The high infrared reflectance heat insulation double-layer paint layer structure according to claim 2, characterized in that, The infrared reflective pigment is selected from one of aluminum silver paste dispersion, black pigment dispersion, or white pigment dispersion, in parts by weight. The aluminum silver paste dispersion comprises: 5-15 parts deionized water Dispersant 0.1-1 part 2-7 parts aluminum silver paste The preparation steps of the aluminum silver paste dispersion include: mixing deionized water, dispersant and aluminum silver paste evenly, and letting it stand for 1.5-3 hours to obtain the aluminum silver paste dispersion. The black pigment dispersion or the white pigment dispersion comprises: The preparation steps of the black pigment dispersion or white pigment dispersion include: mixing deionized water, dispersant, and black or white pigment evenly, adjusting the pH to 7.5-8.5 with a pH adjuster, and then milling for 1-2 hours until the fineness is less than 10 μm to obtain the black pigment dispersion or white pigment dispersion. Preferably, the aluminum silver paste is a flake-shaped aluminum pigment coated with resin or silicon oxide, the black pigment is a black reflective pigment with infrared reflective effect, and the white pigment is titanium dioxide with infrared reflective effect; more preferably, the aluminum silver paste is a water-based aluminum pigment coated with silicon dioxide, which has a silver dollar-shaped or irregular flake structure, a particle size of 5-50 μm, and a thickness of 30-500 nm.

7. A high infrared reflectance heat-insulating coating system, characterized in that, It includes a clear varnish layer (1), a second color paint layer (2), a first color paint layer (3), and a primer layer (4); the clear varnish used in the clear varnish layer (1) is a hydroxyl acrylic resin composition cured by isocyanate; the primer used in the primer layer (4) is a two-component coating composition of polyamine resin cured by high solids isocyanate; the first color paint layer (3) is an enhanced infrared reflective layer with added flake reflective pigments, the second color paint layer (2) is a black coating with high infrared transmittance, and the first color paint used in the first color paint layer (3) and the second color paint used in the second color paint layer (2) are both mixtures containing acrylic resin and polyurethane resin.

8. The high infrared reflectance heat-insulating coating system according to claim 7, characterized in that, The varnish has a viscosity range of 100-5000 mPa·s, and the primer has a solid content of more than 70% and a viscosity range of 100-20000 mPa·s; preferably, the varnish is selected from Nippon Paint's C7900 varnish and the primer is selected from Nippon Paint's P7001 primer.

9. The high infrared reflectance heat-insulating coating system according to claim 7, characterized in that, The preparation steps of the high infrared reflectance heat insulation coating system include: (1) Preparation of the first color paint: Open the mixing tank and add the solvent, acrylic resin, polyurethane resin, infrared reflective pigment, infrared transparent pigment, wetting and leveling agent, defoamer, and thickener in sequence. Stir until fully mixed. Adjust the pH to 7.5-8.5 with a pH adjuster to obtain the first color paint. (2) Preparation of the second color paint: Open the mixing tank and add the solvent, acrylic resin, polyurethane resin, infrared transparent pigment, wetting and leveling agent, defoamer, and thickener in sequence. Stir until fully mixed. Adjust the pH to 7.5-8.5 with a pH adjuster to obtain the second color paint. (3) Spray the first color paint on the surface of the primer layer (4) and flash dry at 60-80℃ for 5-10 minutes to obtain the first color paint layer (3); continue to spray the second color paint on the surface of the first color paint layer (3) and dry at 60-80℃ for 10-30 minutes to obtain the second color paint layer (2); spray the clear varnish layer (1) on the surface of the second color paint layer (2) and cure at 60-100℃ for 30-120 minutes to obtain the high infrared reflection heat insulation coating system.

10. An application of the high infrared reflectance heat insulation coating system as described in any one of claims 7-9, including applications in aircraft, automobiles, and smart devices.

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