Infrared reflection composite heat insulation coating and preparation method thereof

Abstract

The invention relates to the technical field of coatings, and discloses an infrared reflection composite heat insulation coating and a preparation method thereof. Comprising the following components in parts by weight: 0.1-0.3 part by mass of a wetting agent, 0.5-1.5 parts by mass of a dispersing agent, 0.2-0.8 part by mass of a defoaming agent, 0.1-0.5 part by mass of a pH regulator, 0.5-2 parts by mass of a flatting agent, 1.5-3 parts by mass of a coalescing agent, 30-50 parts by mass of pure acrylic emulsion, 10-20 parts by mass of phosphorus-containing modified titanium dioxide, 2-10 parts by mass of phosphorus-containing modified hollow glass beads and 2-8 parts by mass of silicon dioxide aerogel powder. The infrared reflection composite heat insulation coating prepared by the preparation method disclosed by the invention has excellent heat insulation effect and flame retardant effect, and is suitable for the field of building heat insulation coatings.

Description

Technical Field

[0001] The invention relates to the technical field of coatings, in particular to an infrared reflecting composite heat-insulating coating and a preparation method thereof. Background Art

[0002] With the continuous development of modern social economy, energy consumption is increasing day by day, and building energy consumption accounts for about one-third of the total social energy consumption. Therefore, building energy conservation is particularly important in optimizing energy-saving structure and controlling energy consumption. In the field of building insulation, the development and application of new insulation materials have played an important role.

[0003] Thermal insulation coating is one of the important fields of thermal insulation materials. Thermal insulation coating is a functional coating with thermal insulation effect. It can effectively prevent heat conduction, reduce the surface coating and internal environment temperature, thereby improving the working environment and reducing energy consumption. It is widely used in building exterior walls, automobile shells and other fields. According to its mechanism of action, it can be divided into reflective thermal insulation coating, barrier thermal insulation coating and radiation thermal insulation coating. At present, with the improvement of thermal insulation performance requirements, composite thermal insulation coating has become a hot spot in research and development.

[0004] For example, the patent with application publication number CN 107936752 A discloses a hollow glass microsphere-based fluorocarbon reflective thermal insulation coating and a preparation method thereof. The invention uses hollow glass microspheres, fluorocarbon emulsion, etc. as raw materials to obtain a hollow glass microsphere-based fluorocarbon reflective thermal insulation coating. The reflective thermal insulation coating has a low conductivity coefficient and good thermal insulation effect, but does not improve the flame retardant properties of the thermal insulation coating. Summary of the invention

[0005] 1. Technical issues to be resolved In view of the deficiencies in the prior art, the present invention provides an infrared reflective composite thermal insulation coating and a preparation method thereof. The prepared thermal insulation coating has good thermal insulation performance and flame retardant performance.

[0006] (II) Technical solution An infrared reflective composite heat-insulating coating, the infrared reflective composite heat-insulating coating consisting of the following components in parts by weight: 0.1-0.3 parts by weight of a wetting agent, 0.5-1.5 parts by weight of a dispersant, 0.2-0.8 parts by weight of a defoamer, 0.1-0.5 parts by weight of a pH adjuster, 0.5-2 parts by weight of a leveling agent, 1.5-3 parts by weight of a film-forming aid, 30-50 parts by weight of a pure acrylic emulsion, 10-20 parts by weight of phosphorus-modified titanium dioxide, 2-10 parts by weight of phosphorus-modified hollow glass microspheres, 2-8 parts by weight of a silica aerogel powder, 1-5 parts by weight of a far-infrared ceramic powder, and the balance being deionized water; The preparation method of the infrared reflective composite thermal insulation coating is as follows: Add a wetting agent, a dispersant, a defoaming agent, a pH adjuster, a leveling agent, and a film-forming aid to deionized water, stir and mix evenly, then add a pure acrylic emulsion, phosphorus-modified titanium dioxide, phosphorus-modified hollow glass microspheres, silica aerogel powder, and far-infrared ceramic powder, stir and mix evenly to obtain an infrared reflective composite thermal insulation coating; The preparation method of the phosphorus-containing modified titanium dioxide is: (1) adding hexachlorocyclotriphosphazene and triethylamine to tetrahydrofuran solvent, stirring to dissolve, then adding trihydroxymethylphosphine sulfide, stirring and reacting at 90-100° C. for 12-20 hours, after the reaction is completed, filtering, distilling under reduced pressure, washing with deionized water, and drying to obtain trihydroxycyclotriphosphazene; (2) adding trihydroxycyclotriphosphazene and isocyanatepropyltriethoxysilane to tetrahydrofuran solvent, stirring and dispersing, and then adding dibutyltin dilaurate thereto, stirring and reacting at 75-85° C. for 12-24 hours. After the reaction is completed, rotary evaporation and drying are performed to obtain polysilylcyclotriphosphazene; (3) Adding ammonia water to a 50% by mass ethanol aqueous solution to adjust the pH to 9, adding dry titanium dioxide thereto, dispersing by ultrasonication, raising the temperature to 75-85° C., adding polysilyl cyclotriphosphazene thereto, stirring and reacting for 1-3 hours, aging at room temperature after the reaction is completed, filtering by suction, washing with deionized water, and drying to obtain phosphorus-containing modified titanium dioxide.

[0007] Preferably, in (1), the usage ratio of hexachlorocyclotriphosphazene, triethylamine and trishydroxymethylphosphine sulfide is 1 g: (1.5-2) g: (1.2-1.5) g.

[0008] Preferably, in (2), the usage ratio of trihydroxycyclotriphosphazene to isocyanatepropyltriethoxysilane is 1 g:(1.2-1.5) g.

[0009] Preferably, in (3), the mass ratio of titanium dioxide to polysilyl cyclotriphosphazene is 1:0.1-0.5.

[0010] Preferably, the preparation method of the phosphorus-modified hollow glass microspheres is: adding hydroxyl-modified hollow glass microspheres to 90% by mass ethanol aqueous solution, stirring and dispersing, heating to 85-95° C., adding polysilyl cyclotriphosphazene thereto, stirring and reacting for 3-6 hours, after the reaction is completed, filtering, washing with deionized water, and drying to obtain phosphorus-modified hollow glass microspheres.

[0011] Preferably, the usage ratio of the hydroxyl-modified hollow glass microspheres and the polysilyl cyclotriphosphazene is 1 g: (1.5-2.5) g.

[0012] 3. Beneficial technical effects The invention uses triethylamine as an acid-binding agent, hexachlorocyclotriphosphazene and trihydroxymethylphosphine sulfide as raw materials, synthesizes trihydroxycyclotriphosphazene, and synthesizes polysilylcyclotriphosphazene with isocyanate propyltriethoxysilane under the catalysis of dibutyltin dilaurate, and sequentially condenses with hydroxyl-modified hollow glass microspheres and titanium dioxide by utilizing the characteristic that silicon oxygen bonds in the polysilylcyclotriphosphazene are easily hydrolyzed, so as to obtain phosphorus-modified hollow glass microspheres and phosphorus-modified titanium dioxide, and pure acrylic emulsion, phosphorus-modified titanium dioxide, phosphorus-modified hollow glass microspheres, silicon dioxide aerogel powder, far-infrared ceramic powder and the like are added into deionized water, and the mixture is stirred and mixed uniformly to obtain infrared reflection composite heat-insulating coating.

[0013] The polysilyl cyclotriphosphazene prepared by the present invention contains a large amount of flame retardant elements, which together form a phosphorus-nitrogen-silicon synergistic flame retardant system. Hollow glass microspheres and titanium dioxide are inorganic materials and have poor compatibility with the coating. Therefore, the hollow glass microspheres and titanium dioxide are surface modified to increase the compatibility of the hollow glass microspheres and titanium dioxide in the coating. The silicon-oxygen bonds in the polysilyl cyclotriphosphazene are condensed with the inorganic materials, namely, hydroxyl-modified hollow glass microspheres and titanium dioxide to obtain phosphorus-modified hollow glass microspheres and phosphorus-modified titanium dioxide, thereby forming an organic-inorganic synergistic flame retardant system and further improving the flame retardant effect of the coating.

[0014] The invention uses far-infrared ceramic powder, titanium dioxide, and hollow glass microspheres as reflective fillers, and silica aerogel as barrier filler. The two heat-insulating mechanisms work synergistically to form a system of multiple heat-insulating mechanisms, forming a heat-insulating network in the coating, thereby obtaining a good heat-insulating effect. The coating prepared by the invention has good heat-insulating effect and flame-retardant effect. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 This is the reaction route for polysilylcyclotriphosphazene. DETAILED DESCRIPTION

[0016] In order to make the objectives, technical solutions and beneficial effects of the present invention more clear, preferred embodiments of the present invention will be described in detail below with reference to the accompanying drawings.

[0017] Preparation method of hydroxyl-modified hollow glass microspheres: add 10 g of hollow glass microspheres into 200 mL of 0.5 mol / L sodium hydroxide aqueous solution, stir and disperse, heat to 90° C., etch for 2 h, let stand and then filter, wash with deionized water until neutral, and dry to obtain hydroxyl-modified hollow glass microspheres.

[0018] The wetting agent is wetting agent PE-100; the dispersant is dispersant RT-8040; the defoaming agent is defoaming agent NXZ; the pH adjusting agent is sodium bicarbonate; the leveling agent is leveling agent ND-8020; and the film-forming aid is film-forming aid TEXANOL.

[0019] Preparation Example 1 (1) Add 10 g of hexachlorocyclotriphosphazene and 20 g of triethylamine to tetrahydrofuran solvent, stir to dissolve, then add 15 g of trihydroxymethylphosphine sulfide, stir and react at 95°C for 20 h. After the reaction is completed, filter, evaporate under reduced pressure, wash with deionized water, and dry to obtain trihydroxycyclotriphosphazene.

[0020] (2) Add 6 g of trihydroxycyclotriphosphazene and 8 g of isocyanatepropyltriethoxysilane to tetrahydrofuran solvent, stir and disperse, then add 20 mg of dibutyltin dilaurate, stir and react at 80° C. for 19 h. After the reaction is completed, rotary evaporate and dry to obtain polysilylcyclotriphosphazene.

[0021] (3) Add 10 g of hydroxyl-modified hollow glass microspheres to 90% by mass ethanol aqueous solution, stir and disperse, heat to 90°C, add 15 g of polysilyl cyclotriphosphazene, stir and react for 5 h, and after the reaction is completed, filter, wash with deionized water, and dry to obtain phosphorus-modified hollow glass microspheres.

[0022] (4) Ammonia water was added to a 50% by mass ethanol aqueous solution to adjust the pH to 9, and then 20 g of dry titanium dioxide was added thereto, and ultrasonic dispersion was performed. The temperature was raised to 85°C, and 2 g of polysilyl cyclotriphosphazene was added thereto. The reaction was stirred for 1 h. After the reaction was completed, the mixture was aged at room temperature, filtered, washed with deionized water, and dried to obtain phosphorus-modified titanium dioxide.

[0023] (5) Add 0.1 g of wetting agent, 1.5 g of dispersant, 0.2 g of defoaming agent, 0.4 g of pH adjuster, 0.6 g of leveling agent and 2 g of film-forming aid to 30.2 g of deionized water, stir and mix evenly, then add 50 g of pure acrylic emulsion, 10 g of phosphorus-modified titanium dioxide, 2 g of phosphorus-modified hollow glass microspheres, 2 g of silica aerogel powder and 1 g of far-infrared ceramic powder, stir and mix evenly to obtain an infrared reflective composite thermal insulation coating.

[0024] Preparation Example 2 (1) Add 10 g of hexachlorocyclotriphosphazene and 15 g of triethylamine to tetrahydrofuran solvent, stir to dissolve, then add 14 g of trihydroxymethylphosphine sulfide, stir and react at 100°C for 15 h. After the reaction is completed, filter, evaporate under reduced pressure, wash with deionized water, and dry to obtain trihydroxycyclotriphosphazene.

[0025] (2) Add 6 g of trihydroxycyclotriphosphazene and 9 g of isocyanatepropyltriethoxysilane to tetrahydrofuran solvent, stir and disperse, then add 25 mg of dibutyltin dilaurate, stir and react at 85°C for 12 h. After the reaction is completed, rotary evaporate and dry to obtain polysilylcyclotriphosphazene.

[0026] (3) Add 10 g of hydroxyl-modified hollow glass microspheres to 90% by mass ethanol aqueous solution, stir and disperse, heat to 90°C, add 18 g of polysilyl cyclotriphosphazene, stir and react for 3 h, and after the reaction is completed, filter, wash with deionized water, and dry to obtain phosphorus-modified hollow glass microspheres.

[0027] (4) Ammonia water was added to a 50% by mass ethanol aqueous solution to adjust the pH to 9, and then 20 g of dry titanium dioxide was added thereto, and ultrasonic dispersion was performed. The temperature was raised to 75°C, and 4 g of polysilyl cyclotriphosphazene was added thereto. The reaction was stirred for 3 h. After the reaction was completed, the mixture was aged at room temperature, filtered, washed with deionized water, and dried to obtain phosphorus-modified titanium dioxide.

[0028] (5) Add 0.2 g of wetting agent, 0.5 g of dispersant, 0.8 g of defoaming agent, 0.1 g of pH adjuster, 2 g of leveling agent and 3 g of film-forming aid to 39.4 g of deionized water, stir and mix evenly, then add 30 g of pure acrylic emulsion, 14 g of phosphorus-modified titanium dioxide, 4 g of phosphorus-modified hollow glass microspheres, 4 g of silica aerogel powder and 2 g of far-infrared ceramic powder, stir and mix evenly to obtain an infrared reflective composite thermal insulation coating.

[0029] Preparation Example 3 (1) Add 10 g of hexachlorocyclotriphosphazene and 16 g of triethylamine to tetrahydrofuran solvent, stir to dissolve, then add 12 g of trihydroxymethylphosphine sulfide, stir and react at 90°C for 12 h. After the reaction is completed, filter, evaporate under reduced pressure, wash with deionized water, and dry to obtain trihydroxycyclotriphosphazene.

[0030] (2) Add 6 g of trihydroxycyclotriphosphazene and 9 g of isocyanatepropyltriethoxysilane to tetrahydrofuran solvent, stir and disperse, then add 15 mg of dibutyltin dilaurate, stir and react at 80°C for 24 h. After the reaction is completed, rotary evaporate and dry to obtain polysilylcyclotriphosphazene.

[0031] (3) Add 10 g of hydroxyl-modified hollow glass microspheres to 90% by mass ethanol aqueous solution, stir and disperse, heat to 85°C, add 20 g of polysilyl cyclotriphosphazene, stir and react for 6 h, and after the reaction is completed, filter, wash with deionized water, and dry to obtain phosphorus-modified hollow glass microspheres.

[0032] (4) Ammonia water was added to a 50% by mass ethanol aqueous solution to adjust the pH to 9, and then 20 g of dry titanium dioxide was added thereto, and ultrasonic dispersion was performed. The temperature was raised to 80°C, and 6 g of polysilyl cyclotriphosphazene was added thereto. The reaction was stirred for 2 h. After the reaction was completed, the mixture was aged at room temperature, filtered, washed with deionized water, and dried to obtain phosphorus-modified titanium dioxide.

[0033] (5) Add 0.2 g of wetting agent, 1.5 g of dispersant, 0.5 g of defoaming agent, 0.1 g of pH adjuster, 2 g of leveling agent and 1.5 g of film-forming aid to 28.2 g of deionized water, stir and mix evenly, then add 35 g of pure acrylic emulsion, 16 g of phosphorus-modified titanium dioxide, 6 g of phosphorus-modified hollow glass microspheres, 6 g of silica aerogel powder and 3 g of far-infrared ceramic powder, stir and mix evenly to obtain an infrared reflective composite thermal insulation coating.

[0034] Preparation Example 4 (1) Add 10 g of hexachlorocyclotriphosphazene and 15 g of triethylamine to tetrahydrofuran solvent, stir to dissolve, then add 15 g of trihydroxymethylphosphine sulfide, stir and react at 95°C for 14 h. After the reaction is completed, filter, evaporate under reduced pressure, wash with deionized water, and dry to obtain trihydroxycyclotriphosphazene.

[0035] (2) Add 6 g of trihydroxycyclotriphosphazene and 8 g of isocyanatepropyltriethoxysilane to tetrahydrofuran solvent, stir and disperse, then add 20 mg of dibutyltin dilaurate, stir and react at 85°C for 12 h. After the reaction is completed, rotary evaporate and dry to obtain polysilylcyclotriphosphazene.

[0036] (3) Add 10 g of hydroxyl-modified hollow glass microspheres to 90% by mass ethanol aqueous solution, stir and disperse, heat to 90°C, add 23 g of polysilyl cyclotriphosphazene, stir and react for 6 h, and after the reaction is completed, filter, wash with deionized water, and dry to obtain phosphorus-modified hollow glass microspheres.

[0037] (4) Ammonia water was added to a 50% by mass ethanol aqueous solution to adjust the pH to 9, and then 20 g of dry titanium dioxide was added thereto, and ultrasonic dispersion was performed. The temperature was raised to 85°C, and 8 g of polysilyl cyclotriphosphazene was added thereto. The reaction was stirred for 2 h. After the reaction was completed, the mixture was aged at room temperature, filtered, washed with deionized water, and dried to obtain phosphorus-modified titanium dioxide.

[0038] (5) Add 0.2 g of wetting agent, 1.5 g of dispersant, 0.8 g of defoaming agent, 0.5 g of pH adjuster, 2 g of leveling agent and 2 g of film-forming aid to 34 g of deionized water, stir and mix evenly, then add 30 g of pure acrylic emulsion, 18 g of phosphorus-modified titanium dioxide, 8 g of phosphorus-modified hollow glass microspheres, 7 g of silica aerogel powder and 4 g of far-infrared ceramic powder, stir and mix evenly to obtain an infrared reflective composite thermal insulation coating.

[0039] Preparation Example 5 (1) Add 10 g of hexachlorocyclotriphosphazene and 20 g of triethylamine to tetrahydrofuran solvent, stir to dissolve, then add 14 g of trihydroxymethylphosphine sulfide, stir and react at 95°C for 20 h. After the reaction is completed, filter, evaporate under reduced pressure, wash with deionized water, and dry to obtain trihydroxycyclotriphosphazene.

[0040] (2) Add 6 g of trihydroxycyclotriphosphazene and 7.2 g of isocyanatepropyltriethoxysilane to tetrahydrofuran solvent, stir and disperse, then add 25 mg of dibutyltin dilaurate, stir and react at 75°C for 20 h. After the reaction is completed, rotary evaporate and dry to obtain polysilylcyclotriphosphazene.

[0041] (3) Add 10 g of hydroxyl-modified hollow glass microspheres to 90% by mass ethanol aqueous solution, stir and disperse, heat to 95°C, add 25 g of polysilyl cyclotriphosphazene, stir and react for 4 h, and after the reaction is completed, filter, wash with deionized water, and dry to obtain phosphorus-modified hollow glass microspheres.

[0042] (4) Ammonia water was added to a 50% by mass ethanol aqueous solution to adjust the pH to 9, and then 20 g of dry titanium dioxide was added thereto, and ultrasonic dispersion was performed. The temperature was raised to 80°C, and 10 g of polysilyl cyclotriphosphazene was added thereto. The reaction was stirred for 3 h. After the reaction was completed, the mixture was aged at room temperature, filtered, washed with deionized water, and dried to obtain phosphorus-modified titanium dioxide.

[0043] (5) Add 0.3 g of wetting agent, 1 g of dispersant, 0.5 g of defoaming agent, 0.5 g of pH adjuster, 0.5 g of leveling agent and 2.5 g of film-forming aid to 11.7 g of deionized water, stir and mix evenly, then add 40 g of pure acrylic emulsion, 20 g of phosphorus-modified titanium dioxide, 10 g of phosphorus-modified hollow glass microspheres, 8 g of silica aerogel powder and 5 g of far-infrared ceramic powder, stir and mix evenly to obtain an infrared reflective composite thermal insulation coating.

[0044] Use a film-making machine to quickly and evenly form a film along the longitudinal direction on a glass plate. After the coating is dry, repeat the film-making twice and dry naturally for 48 hours to obtain a coating.

[0045] According to GB / T9271-2008, test the thermal insulation temperature difference of the coating.

[0046] The solar reflectance of the coating was tested using a UV-Vis-NIR spectrophotometer.

[0047] Table 1:

[0048] It can be seen from the table that the minimum insulation temperature difference is 11.9°C and the maximum is 19.5°C, the minimum solar reflectance is 0.85 and the maximum is 0.94, all of which can meet the national indicators of building thermal insulation coatings, that is, the thermal insulation temperature difference is greater than 10°C, and the solar reflectance is greater than 0.8. Therefore, the coating prepared by the present invention has a good thermal insulation effect.

[0049] Use an oxygen index tester to test the limiting oxygen index of the coating.

[0050] Use a vertical combustion tester to test the vertical combustion rating of the coating.

[0051] Table 2:

[0052] It can be seen from the table that the coating prepared by the present invention has a good flame retardant effect, and the maximum limiting oxygen index can reach 34.6.

[0053] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and do not constitute a limitation on the content of the present invention. Although the present invention has been exemplified in detail through the above embodiments, those skilled in the art can still make various changes in form and details according to the technical contents described in the Summary of the Invention and the Examples, without departing from the spirit and scope of the present invention as defined in the attached claims.

Claims

1. An infrared reflective composite thermal insulation coating, characterized in that: The infrared reflective composite thermal insulation coating is composed of the following components in parts by weight: 0.1-0.3 parts by weight of a wetting agent, 0.5-1.5 parts by weight of a dispersant, 0.2-0.8 parts by weight of a defoamer, 0.1-0.5 parts by weight of a pH adjuster, 0.5-2 parts by weight of a leveling agent, 1.5-3 parts by weight of a film-forming aid, 30-50 parts by weight of a pure acrylic emulsion, 10-20 parts by weight of phosphorus-modified titanium dioxide, 2-10 parts by weight of phosphorus-modified hollow glass microspheres, 2-8 parts by weight of a silica aerogel powder, 1-5 parts by weight of a far-infrared ceramic powder, and the balance is deionized water; The preparation method of the infrared reflective composite thermal insulation coating is as follows: Add a wetting agent, a dispersant, a defoaming agent, a pH adjuster, a leveling agent, and a film-forming aid to deionized water, stir and mix evenly, then add a pure acrylic emulsion, phosphorus-modified titanium dioxide, phosphorus-modified hollow glass microspheres, silica aerogel powder, and far-infrared ceramic powder, stir and mix evenly to obtain an infrared reflective composite thermal insulation coating; The preparation method of the phosphorus-containing modified titanium dioxide is: (1) adding hexachlorocyclotriphosphazene and triethylamine to tetrahydrofuran solvent, stirring to dissolve, then adding trihydroxymethylphosphine sulfide, stirring and reacting at 90-100° C. for 12-20 hours, after the reaction is completed, filtering, distilling under reduced pressure, washing with deionized water, and drying to obtain trihydroxycyclotriphosphazene; (2) adding trihydroxycyclotriphosphazene and isocyanatepropyltriethoxysilane to tetrahydrofuran solvent, stirring and dispersing, and then adding dibutyltin dilaurate thereto, stirring and reacting at 75-85° C. for 12-24 hours. After the reaction is completed, rotary evaporation and drying are performed to obtain polysilylcyclotriphosphazene; (3) Adding ammonia water to a 50% by mass ethanol aqueous solution to adjust the pH to 9, adding dry titanium dioxide thereto, dispersing by ultrasonication, raising the temperature to 75-85° C., adding polysilyl cyclotriphosphazene thereto, stirring and reacting for 1-3 hours, aging at room temperature after the reaction is completed, filtering by suction, washing with deionized water, and drying to obtain phosphorus-containing modified titanium dioxide.

2. The infrared reflective composite thermal insulation coating according to claim 1, characterized in that: In the above (1), the usage ratio of hexachlorocyclotriphosphazene, triethylamine and trishydroxymethylphosphine sulfide is 1g:(1.5-2)g:(1.2-1.5)g.

3. The infrared reflective composite thermal insulation coating according to claim 1, characterized in that: In the above (2), the usage ratio of trihydroxycyclotriphosphazene to isocyanatepropyltriethoxysilane is 1 g:(1.2-1.5) g.

4. The infrared reflective composite thermal insulation coating according to claim 1, characterized in that: In the above (3), the mass ratio of titanium dioxide to polysilyl cyclotriphosphazene is 1:0.1-0.

5.

5. The infrared reflective composite thermal insulation coating according to claim 1, characterized in that: The preparation method of the phosphorus-modified hollow glass microspheres is as follows: adding hydroxyl-modified hollow glass microspheres to 90% by mass ethanol aqueous solution, stirring and dispersing, heating to 85-95° C., adding polysilyl cyclotriphosphazene thereto, stirring and reacting for 3-6 hours, and after the reaction is completed, filtering, washing with deionized water, and drying to obtain the phosphorus-modified hollow glass microspheres.

6. The infrared reflective composite thermal insulation coating according to claim 5, characterized in that: The usage ratio of the hydroxyl-modified hollow glass microspheres and the polysilyl cyclotriphosphazene is 1 g: (1.5-2.5) g.

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