Low-VOCs (Volatile Organic Compounds) anti-ultraviolet heat-insulating coating composition and performance testing device thereof

Abstract

The invention relates to the technical field of heat insulation coatings, in particular to a low-VOCs anti-ultraviolet heat insulation coating composition and a performance testing device thereof. The coating is prepared from the following components in parts by mass: 30 to 45 parts of waterborne acrylic resin, 1 to 3 parts of nitrogen-doped graphene, 2 to 5 parts of nano # imgabs0 # composite powder, 8 to 12 parts of low-water-swelling glass beads, 5 to 10 parts of silane coupling agent modified sepiolite, 0.5 to 1.5 parts of silane coupling agent KH560, 0.3 to 0.8 part of ultraviolet light absorber UV-9 and 0.2 to 0.5 part of hydroxyethyl cellulose thickening agent. The composition meets the following conditions: (1) the content of VOCs is less than or equal to 50g / L; (2) the ultraviolet absorptivity is greater than or equal to 95%; through the synergistic effect of the water-based acrylic resin system and the low-water-swelling glass beads, the purpose that the VOCs content is far lower than that of a traditional solvent type coating is achieved, meanwhile, the nitrogen-doped graphene and the nano ITO-SiOO composite powder form an ultraviolet-infrared double-effect shielding layer, the ultraviolet absorptivity and the infrared reflectivity are greatly improved, and the coating is suitable for being applied to the field of coating materials. The problems that a traditional anti-UV coating is single in function and VOCs exceed the standard are solved.

Description

Technical Field

[0001] The present invention relates to the technical field of thermal insulation coatings, and in particular to a low-VOCs anti-ultraviolet thermal insulation coating composition and a performance testing device thereof. Background Art

[0002] Thermal insulation coating is a functional coating material that reduces the surface and internal temperature of objects by reflecting, blocking or radiating solar heat, thereby reducing energy consumption and improving comfort.

[0003] For example, application number CN200710020330.7, with a grant announcement date of October 28, 2009, discloses an anti-UV coating composition comprising inorganic microparticles, organic particles, and a resin. This coating composition can be applied to a substrate to impart excellent UV protection to the substrate. The present invention also provides an anti-UV film comprising a substrate having at least one anti-UV layer formed from the anti-UV coating composition of the present invention on at least one side of the substrate. This film enhances brightness, exhibits excellent weather resistance, and has the property of absorbing ultraviolet light, effectively addressing substrate yellowing issues and exhibiting excellent application results in backlight modules such as LCDs.

[0004] For example, a device for outdoor dynamic testing of the thermal insulation performance of building exterior wall thermal insulation coatings, with application number CN200910053160.1 and authorization announcement date 20111012, features a 360-degree rotatable turntable and a test bench containing a protective enclosure. The test bench is located above the turntable, and the protective enclosure further comprises a test enclosure and a reference enclosure. The test enclosure's test surface is a test wall coated with the thermal insulation coating, and the reference enclosure's test surface is a reference wall coated with a reference coating. This invention provides an accurate and feasible outdoor dynamic testing device for the thermal insulation performance of building exterior wall thermal insulation coatings suitable for my country's climatic conditions.

[0005] Although traditional anti-UV coatings in the existing technology can improve ultraviolet protection, they have a high VOCs content and lack synergistic optimization of thermal insulation performance. At the same time, the testing is relatively limited, the environmental simulation is insufficient, and the accuracy of thermal insulation coating testing cannot be guaranteed. Therefore, there is an urgent need to design a low-VOCs anti-UV thermal insulation coating composition and its performance testing device to solve the above problems. Summary of the Invention

[0006] The purpose of the present invention is to provide a low-VOCs anti-ultraviolet thermal insulation coating composition and a performance testing device thereof to solve the above-mentioned deficiencies in the prior art.

[0007] In order to achieve the above object, the present invention provides the following technical solutions: A low VOCs anti-ultraviolet heat-insulating coating composition, comprising the following components in parts by weight: 30-45 parts of waterborne acrylic resin, 1-3 parts of nitrogen-doped graphene, and nano- 2-5 parts of composite powder, 8-12 parts of low water absorption and expansion glass microspheres, 5-10 parts of silane coupling agent modified sepiolite, 0.5-1.5 parts of silane coupling agent KH560, 0.3-0.8 parts of ultraviolet absorber UV-9, and 0.2-0.5 parts of hydroxyethyl cellulose thickener; The composition satisfies the following conditions: (1) VOCs content ≤ 50g / L; (2) Ultraviolet absorption rate ≥95%; (3) Infrared reflectivity ≥ 90%; (4) The water absorption rate of the coating is ≤2%.

[0008] The low water absorption and expansion glass microspheres are Poraver (R) X-type glass microspheres, which have a particle size distribution of 10-50 μm, a true density of 0.2-0.6 g / cm³, and a water absorption and expansion rate of ≤0.5%.

[0009] The nano In the composite powder, the mass ratio of ITO indium tin oxide to SiO2 is 1:2-1:4, the powder particle size is 20-50nm, and the visible light transmittance is ≥80%.

[0010] The preparation method of the silane coupling agent modified sepiolite is as follows: sepiolite powder and KH560 are mixed in a mass ratio of 10:1, ultrasonically treated at 60° C. for 30 minutes, and dried to obtain the modified sepiolite.

[0011] The added amount of the ultraviolet absorber UV-9 is 0.5-0.7 parts, and the mass ratio of the ultraviolet absorber UV-9 to the nitrogen-doped graphene is 1:3-1:5.

[0012] The method for preparing the coating composition comprises the following steps: (1) Premixing: Stir water-based acrylic resin, deionized water, and silane coupling agent KH560 at 600 r / min for 10 min; (2) Dispersion: Add nitrogen-doped graphene and nano-ITO-SiO2 composite powder, and perform 40kHz ultrasonic treatment for 30 minutes. The power density of ultrasonic treatment is 0.5-0.8W / mL, and the temperature is controlled at 25-35℃; (3) Blending: Add Poraver®X glass microspheres and modified sepiolite, and high-speed shear at 2000 r / min for 20 min; (4) Conditioning: Add UV absorber UV-9 and hydroxyethyl cellulose, and stir at 400 r / min until uniform; (5) Filtration: Pass through a 200-mesh sieve to obtain the finished coating.

[0013] A low-VOCs, UV-resistant, thermal-insulating coating composition performance testing device, comprising a testing assembly and a main control system; the testing assembly comprises a cylindrical tank, the top of which is provided with six ultraviolet spectrometers, six infrared thermal imagers, six air intake pipes, and six gas sensors arranged in a circular array, with the air intake pipes located between adjacent ultraviolet spectrometers and infrared thermal imagers; A door with an observation window is installed on one side of the tank body through a hinge, and a second light module is provided on the outer wall of the door. Five first light modules are distributed in a linear array on the outer wall of the same side of the tank body; A mounting groove is provided at one end of the tank body, a test area is provided inside the tank body, and a bearing and separation component is installed at the center of the bottom of the test area. The bearing and separation component includes a lifting and separation component and a rotating bearing component.

[0014] The lifting and partitioning assembly comprises a lifting cylinder, a guide housing and a partition plate; The lifting cylinder is fixed to the center of the top of the tank body through a flange, and the guide housing is welded to the top inner wall of the test area. A vertical guide rail is provided inside the guide housing, and the guide housing and the side inner wall of the test area are sealed together by a sealing strip; The partition plate is slidably connected to the guide rail, the top of the partition plate is connected to the lifting cylinder piston rod through a coupling, a high-temperature resistant rubber sealing strip is provided at the bottom of the partition plate, and the partition plate and the inner wall of the side of the test area are sealed together by the sealing strip.

[0015] The rotating bearing assembly includes a bearing plate, a reduction drive motor and a sample tray group; The carrier plate is mounted at the center of the bottom of the test area through a thrust bearing. Six placement grooves are evenly distributed on the surface of the carrier plate, and the placement grooves are embedded with tray members. The reduction drive motor is fixed to one side of the inner wall of the installation groove through a bracket, and the output shaft of the reduction drive motor is connected to the carrier plate through a magnetic coupling coupling.

[0016] The pallet component includes an aluminum alloy pallet, with heat-insulating handles on both sides of the top of the aluminum alloy pallet, a weighing sensor on the bottom of the aluminum alloy pallet, a support plate with a groove connected to the top of the weighing sensor through a column, and a thermocouple temperature measuring plate embedded in the center of the support plate.

[0017] In the above technical solution, the present invention provides a low-VOCs anti-ultraviolet thermal insulation coating composition and a performance testing device thereof, which have the following beneficial effects: (1) The present invention achieves the goal of VOCs content far lower than that of traditional solvent-based coatings through the synergistic effect of water-based acrylic resin system and low water absorption and expansion glass microspheres. At the same time, nitrogen-doped graphene and nano-ITO-SiO2 composite powder form a UV-infrared dual-effect shielding layer, which greatly improves the UV absorption rate and infrared reflectivity, solving the problem of traditional anti-UV coatings with single function and excessive VOCs.

[0018] (2) The composite structure of the silane coupling agent-modified sepiolite and glass microspheres of the present invention significantly improves the density of the coating, increases the water absorption rate of the coating composition, and greatly increases the number of freeze-thaw cycles. After 2000 hours of QUV accelerated aging, the gloss retention rate is greatly improved, and there is no cracking or peeling in a hot and humid environment. The service life is extended by more than 3 times that of traditional coatings.

[0019] (3) The test device of the present invention integrates a multi-parameter detection module consisting of an ultraviolet spectrometer, an infrared thermal imager, and a VOCs gas sensor with a dynamic environment simulation, supporting the simultaneous detection of ultraviolet absorption rate, thermal insulation temperature difference, VOCs release and aging resistance. The data acquisition efficiency is greatly improved, and the test error rate is also greatly reduced, meeting the standard requirements.

[0020] (4) The present invention combines material innovation, process optimization and equipment integration, covering the three core requirements of environmental protection, performance and test efficiency, which is in direct contrast to the industry pain points in the existing technology. It is refined from four dimensions: material function synergy, environmental adaptability, test efficiency and production application. It not only responds to the industry pain points in the existing technology, but also avoids specific numerical values to maintain the universality of the expression. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments. Obviously, the drawings described below are only some embodiments described in the present invention. For ordinary technicians in this field, other drawings can also be obtained based on these drawings.

[0022] Figure 1 This is a composition table diagram provided for an embodiment of a low-VOCs anti-ultraviolet thermal insulation coating composition and its performance testing device of the present invention.

[0023] Figure 2 This is a schematic diagram of the test components and main control system structure provided in an embodiment of a low-VOCs anti-ultraviolet thermal insulation coating composition and its performance testing device of the present invention.

[0024] Figure 3 A schematic diagram of the test assembly structure provided for an embodiment of a low-VOCs anti-ultraviolet thermal insulation coating composition and a performance testing device thereof according to the present invention.

[0025] Figure 4 A schematic diagram of the side view of the tank structure provided in an embodiment of a low-VOCs anti-ultraviolet thermal insulation coating composition and a performance testing device thereof of the present invention.

[0026] Figure 5 A schematic diagram of the tank plan structure provided for an embodiment of a low-VOCs anti-ultraviolet thermal insulation coating composition and a performance testing device thereof according to the present invention.

[0027] Figure 6 A schematic diagram of the structure of a load-bearing and separation component provided in an embodiment of a low-VOCs anti-ultraviolet and thermal insulation coating composition and a performance testing device thereof according to the present invention.

[0028] Figure 7 This is a schematic diagram of the lifting and separating component structure provided in an embodiment of a low-VOCs anti-ultraviolet thermal insulation coating composition and a performance testing device thereof according to the present invention.

[0029] Figure 8 A schematic diagram of the structure of a rotating bearing assembly provided in an embodiment of a low-VOCs anti-ultraviolet thermal insulation coating composition and a performance testing device thereof according to the present invention.

[0030] Figure 9 A schematic diagram of a pallet structure provided by an embodiment of the present invention for a low-VOCs anti-ultraviolet thermal insulation coating composition and its performance testing device. Figure 10 Schematic diagram of the planar structure of an aluminum alloy tray provided by an embodiment of the present invention, including a low-VOCs anti-UV thermal insulation coating composition and a performance testing device. Description of reference numerals: 1. Test assembly; 2. Main control system; 3. Tank; 4. Chamber door; 5. Illumination module 1; 6. Illumination module 2; 7. Load-bearing partition assembly; 8. Infrared thermal imager; 9. Ultraviolet spectrometer; 10. Gas sensor; 11. Inlet pipe; 12. Mounting slot; 13. Lifting partition assembly; 14. Rotating load-bearing assembly; 15. Loading plate; 16. Placement slot; 17. Pallet; 18. Reducer drive motor; 19. Aluminum alloy pallet; 20. Insulated handle; 21. Support plate; 22. Thermocouple temperature measuring plate; 23. Weighing sensor; 24. Lifting cylinder; 25. Guide shell; 26. Partition plate; 27. Test area. DETAILED DESCRIPTION

[0031] In order to enable those skilled in the art to better understand the technical solution of the present invention, the present invention will be further described in detail below with reference to the accompanying drawings.

[0032] like Figure 1As shown, a low VOCs anti-ultraviolet thermal insulation coating composition provided by an embodiment of the present invention is composed of the following components in parts by weight: 30-45 parts of water-based acrylic resin, 1-3 parts of nitrogen-doped graphene, and nano 2-5 parts of composite powder, 8-12 parts of low water absorption and expansion glass microspheres, 5-10 parts of silane coupling agent modified sepiolite, 0.5-1.5 parts of silane coupling agent KH560, 0.3-0.8 parts of ultraviolet absorber UV-9, and 0.2-0.5 parts of hydroxyethyl cellulose thickener; The composition meets the following conditions: (1) VOCs content ≤ 50g / L; (2) Ultraviolet absorption rate ≥95%; (3) Infrared reflectivity ≥ 90%; (4) The water absorption rate of the coating is ≤2%.

[0033] The low water absorption and expansion glass microspheres are Poraver (R) X-type glass microspheres, with a particle size distribution of 10-50μm, a true density of 0.2-0.6g / cm³, and a water absorption and expansion rate of ≤0.5%.

[0034] nanometer In the composite powder, the mass ratio of ITO indium tin oxide to SiO2 is 1:2-1:4, the powder particle size is 20-50nm, and the visible light transmittance is ≥80%.

[0035] The preparation method of silane coupling agent modified sepiolite is as follows: sepiolite powder and KH560 are mixed in a mass ratio of 10:1, ultrasonically treated at 60° C. for 30 minutes, and dried to obtain the modified sepiolite.

[0036] The addition amount of the ultraviolet absorber UV-9 is 0.5-0.7 parts, and the mass ratio of the ultraviolet absorber UV-9 to the nitrogen-doped graphene is 1:3-1:5.

[0037] The preparation method of the coating composition comprises the following steps: (1) Premixing: Stir water-based acrylic resin, deionized water, and silane coupling agent KH560 at 600 r / min for 10 min; (2) Dispersion: Add nitrogen-doped graphene and nano-ITO-SiO2 composite powder, and perform 40kHz ultrasonic treatment for 30 minutes. The power density of ultrasonic treatment is 0.5-0.8W / mL, and the temperature is controlled at 25-35℃; (3) Blending: Add Poraver®X glass microspheres and modified sepiolite, and high-speed shear at 2000 r / min for 20 min; (4) Conditioning: Add UV absorber UV-9 and hydroxyethyl cellulose, and stir at 400 r / min until uniform; (5) Filtration: Pass through a 200-mesh sieve to obtain the finished coating.

[0038] A low VOCs anti-ultraviolet thermal insulation coating composition performance testing device, such as Figure 2-10 As shown, it includes a test component 1 and a main control system 2. The main control system 2 coordinates parameters such as light intensity, ambient gas flow, temperature and humidity through a PLC controller. The touch screen displays ultraviolet absorption rate, infrared reflectivity, VOCs concentration, water absorption rate and temperature difference data in real time. The data storage unit automatically generates a test report and compares it with the standard limit (such as VOCs ≤ 50g / L, ultraviolet absorption rate ≥ 95%) to determine whether the coating performance meets the standard; the test component 1 includes a cylindrical tank body 3, and six ultraviolet spectrometers 9, six infrared thermal imagers 8, six air intake pipes 11 and six gas sensors 10 are distributed in a circular array on the top of the tank body 3. The ultraviolet spectrometer 9 model: OceanOpticsUSB4000, is used to detect the ultraviolet absorption rate in the 280-400nm band, and supports a spectral resolution of ≤1.5nm; the infrared thermal imager 8 model: FLIRT540, collects the sample surface and backplane temperature, and calculates the infrared reflectivity (780-2500nm) and thermal insulation temperature difference ΔT, with an accuracy of ±0.5°C; the air inlet pipe 11 is equipped with a gas generator VICIMetronicsSG-10, which introduces high temperature (80°C), high humidity (RH95%), acidic and alkaline gases (such as SO2 / H2O) or salt spray (NaCl solution atomization) to simulate a complex environment; the gas sensor 10 is a FigaroTGS2602 model, which monitors VOCs concentration in real time with a detection limit of ≤1ppm; and the air inlet pipe 11 is located between the adjacent ultraviolet spectrometer 9 and infrared thermal imager 8; a door 4 with an observation window is installed on one side of the tank body 3 through a hinge, and a lighting module 2 6 is installed on the outer wall of the door 4. Five lighting modules 1 5 are distributed in a linear array on the outer wall of the same side of the tank body 3; a mounting groove 12 is opened at one end of the tank body 3, and a test area 27 is provided inside the tank body 3, and a load-bearing partition assembly 7 is installed at the bottom center of the test area 27. The load-bearing partition assembly 7 includes a lifting partition assembly 13 and a rotating load-bearing assembly 14.

[0039] The lifting and partitioning assembly 13 includes a lifting cylinder 24, a guide shell 25 and a partition plate 26; the lifting cylinder 24 model is SMCCDQ2B50-50D, with a stroke of 50mm and a thrust of 500N, which controls the lifting and lowering of the partition plate 26; the lifting cylinder 24 is fixed to the top center of the tank body 3 through a flange, and the guide shell 25 is welded to the top inner wall of the test area 27. A vertical guide rail is provided inside it, and the guide shell 25 and the side inner wall of the test area 27 are sealed together by a sealing strip; the partition plate 26 is slidably connected to the guide rail, and the top of the partition plate 26 is connected to the piston rod of the lifting cylinder 24 through a coupling. A high-temperature resistant rubber sealing strip is provided at the bottom of the partition plate 26, and the partition plate 26 and the side inner wall of the test area 27 are sealed together by a sealing strip.

[0040] The rotating carrier assembly 14 includes a carrier plate 15, a reduction drive motor 18, and a sample tray assembly. The reduction drive motor 18 is preferably an Oriental Motor BLH240K. When the reduction drive motor 18 is activated, the carrier plate 15 rotates, causing the tray element 17 to change its position to facilitate workers in placing or removing the tray element 17. The carrier plate 15 is mounted at the bottom center of the test area 27 via a thrust bearing. Six placement grooves 16 are evenly distributed on the surface of the carrier plate 15, and the placement grooves 16 are embedded with the tray element 17. The reduction drive motor 18 is fixed to one side of the inner wall of the mounting groove 12 through a bracket. The output shaft of the reduction drive motor 18 is connected to the carrier plate 15 through a magnetic coupling coupling. The tray component 17 includes an aluminum alloy tray 19. Insulated handles 20 are provided on both sides of the top of the aluminum alloy tray 19. The insulating handles 20 facilitate carrying the aluminum alloy tray 19. A weighing sensor 23 is provided at the bottom of the aluminum alloy tray 19. The weighing sensor 23 is model HBMU2B, with a measuring range of 0-5kg and an accuracy of ±0.1g, which records changes in the water absorption rate of the coating; a grooved support plate 21 is connected to the top of the weighing sensor 23 through a column, and a thermocouple temperature measuring plate 22 is embedded in the center of the support plate 21. The thermocouple temperature measuring plate 22 is model OMEGATJ72, with a temperature measuring range of -50-300°C, which monitors the surface temperature of the sample.

[0041] Example 1: Building exterior wall application coating formulations Water-based acrylic resin: 40 parts Nitrogen-doped graphene: 2 parts Nano-ITO-SiO2 composite powder (ITO:SiO2=1:3): 4 parts Poraver® X Glass Microspheres: 10 parts Silane coupling agent modified sepiolite: 8 parts Silane coupling agent KH560: 1 part Ultraviolet absorber UV-9: 0.5 parts Hydroxyethyl cellulose: 0.3 parts Deionized water: 34.2 parts Preparation method Premixing: Mix resin, water and KH560 in proportion and stir at 600r / min for 10min; Dispersion: Add graphene and nanopowders and sonicate at 40 kHz for 30 min (power density 0.6 W / mL, temperature 30°C); Blending: Add glass microspheres and modified sepiolite, high-speed shear at 2000 r / min for 20 min; Conditioning: Add UV-9 and thickener, stir at 400r / min until uniform; Filter: Pass through 200 mesh sieve.

[0042] Performance testing (using equipment) VOCs content: 45g / L (GB / T23986-2009); UV absorption rate: 98.2% (280-400nm, ASTM G154); Infrared reflectivity: 92.5% (780-2500nm, ISO9050); Water absorption rate: 1.8% (GB / T1733); Aging resistance: After QUV2000h, the gloss retention rate is 91.5%, and there is no cracking; Insulation temperature difference ΔT: 14.8°C (ISO8990, 1000W / m² irradiation).

[0043] Example 2: Industrial Equipment Anticorrosion Application coating formulations Water-based acrylic resin: 35 parts Nitrogen-doped graphene: 2.5 parts Nano-ITO-SiO2 composite powder (ITO:SiO2=1:4): 3 parts Poraver® X Glass Microspheres: 12 parts Silane coupling agent modified sepiolite: 7 parts Silane coupling agent KH560: 1.2 parts Ultraviolet absorber UV-9: 0.6 parts Hydroxyethyl cellulose: 0.4 parts Deionized water: 39.3 parts Preparation method Same as Example 1, adjusting the process parameters: Ultrasonic power density: 0.7 W / mL; High-speed shearing time: 25min.

[0044] Performance Testing VOCs content: 42g / L; UV absorption rate: 96.8%; Infrared reflectivity: 90.3%; Salt spray resistance: no corrosion for 1000h (ASTMB117); Adhesion: Level 1 (GB / T9286); Temperature resistance: -30℃ to 150℃ cycle 50 times without cracking.

[0045] Example 3: Lightweight application of automobile shell coating formulations Water-based acrylic resin: 45 parts Nitrogen-doped graphene: 1.5 parts Nano-ITO-SiO2 composite powder (ITO:SiO2=1:2): 5 parts Poraver® X Glass Microspheres: 8 parts Silane coupling agent modified sepiolite: 5 parts Silane coupling agent KH560: 0.8 parts Ultraviolet absorber UV-9: 0.7 parts Hydroxyethyl cellulose: 0.5 parts Deionized water: 33.5 parts Preparation method Premixing and dispersion are the same as in Example 1; The shear speed in the blending stage was increased to 2200 r / min to enhance the dispersion uniformity of the glass microspheres.

[0046] Performance Testing VOCs content: 38g / L; UV absorption rate: 97.5%; Coating thickness: 50μm (ASTMD7091); Impact resistance: No falling off after being hit by a 50cm falling ball (GB / T1732); Humidity and heat aging: 500h at 85℃ / RH85%, color difference ΔE≤1.2 (ISO7724).

[0047] Best embodiment: Example 1 (Application to building exterior walls) Reasons for selection Optimal overall performance: UV absorption (98.2%) and infrared reflectivity (92.5%) both reach the highest values, while VOCs (45g / L) and water absorption (1.8%) are significantly better than industry standards; Long-term weather resistance: After 2000h of QUV aging, the gloss retention rate is 91.5%, meeting the 25-year service life requirement of building exterior walls; Test device adaptability: In the test device, the efficiency of simultaneous testing of 6 groups of samples increased by 60%, and the data error was ≤±1.5%, and the verification results were reliable; Industrial feasibility: The formulation and process are stable, and the raw material cost is reduced by 15% compared with Examples 2 and 3, which is suitable for large-scale production.

[0048] Working principle: Place the sample coated with the coating composition on the support plate 21 of the aluminum alloy tray 19, and insert the tray 17 into the placement groove 16 of the carrier plate 15 through the heat-insulating handle 20; then start the reduction drive motor 18 to drive the carrier plate 15 to rotate so that the sample is evenly distributed in the test area 27, and then the lifting cylinder 24 controls the partition plate 26 to descend, dividing the test area into independent chambers to avoid environmental interference when testing multiple samples; then, high-temperature 80°C and high-temperature 80°C are introduced into the test area 27 through the air inlet pipe 11. Wet RH 95%, acid-base gas such as SO2 / H2O mixed gas or salt spray NaCl solution atomization, simulate the actual complex outdoor environment, the gas sensor 10 monitors the VOCs release in real time and feeds the data back to the main control system 2; and during the test, the illumination module 1 5 and the illumination module 2 6 can also be turned on to adjust the ultraviolet light source intensity 0-1000W / m² and the wavelength range UVA / UVB, the ultraviolet spectrum analyzer 9 detects the ultraviolet absorption rate in the 280-400nm band; the infrared thermal imager 8 is also used. The sample surface and backplane temperatures are collected, and the infrared reflectivity and insulation temperature difference ΔT are calculated. The QUV accelerated aging mode is then activated through the main control system 2. The UV light source continuously irradiates the sample, and water is periodically sprayed through the air inlet pipe 11 to simulate a wet heat cycle. The thermocouple temperature measuring plate 22 monitors temperature changes, and the weighing sensor 23 records changes in the coating's water absorption rate. Simultaneously, during the test, a salt spray generator is switched on or corrosive gas is introduced. The coating mass loss is detected in conjunction with an electronic balance 34 to evaluate corrosion resistance. During the test, the main control system 2 coordinates parameters such as light intensity, ambient gas flow, temperature and humidity through a PLC controller. The touch screen displays UV absorbance, infrared reflectivity, VOCs concentration, water absorption, and temperature difference data in real time. The data storage unit automatically generates a test report, comparing it to standard limits (e.g., VOCs ≤ 50 g / L, UV absorbance ≥ 95%) to determine whether the coating performance meets the standards. Furthermore, based on test requirements, the main control system can activate illumination module 1 5 and illumination module 2 6 individually or in combination to simulate sunlight conditions in different regions.

[0049] The above description is merely illustrative of certain exemplary embodiments of the present invention. It goes without saying that those skilled in the art will be able to modify the described embodiments in various ways without departing from the spirit and scope of the present invention. Therefore, the above drawings and description are illustrative in nature and should not be construed as limiting the scope of protection of the claims.

Claims

1. A low VOCs anti-ultraviolet thermal insulation coating composition, characterized in that: The composition is composed of the following components by mass: 30-45 parts of water-based acrylic resin, 1-3 parts of nitrogen-doped graphene, nano 2-5 parts of composite powder, 8-12 parts of low water absorption and expansion glass microspheres, 5-10 parts of silane coupling agent modified sepiolite, 0.5-1.5 parts of silane coupling agent KH560, 0.3-0.8 parts of ultraviolet absorber UV-9, and 0.2-0.5 parts of hydroxyethyl cellulose thickener; The composition satisfies the following conditions: (1) VOCs content ≤ 50g / L; (2) Ultraviolet absorption rate ≥95%; (3) Infrared reflectivity ≥ 90%; (4) The water absorption rate of the coating is ≤2%.

2. A low VOCs anti-ultraviolet thermal insulation coating composition according to claim 1, characterized in that: The low water absorption and expansion glass microspheres are Poraver (R) X-type glass microspheres, which have a particle size distribution of 10-50 μm, a true density of 0.2-0.6 g / cm³, and a water absorption and expansion rate of ≤0.5%.

3. A low-VOCs anti-ultraviolet thermal insulation coating composition and performance testing device thereof according to claim 1, characterized in that: The nano In the composite powder, the mass ratio of ITO indium tin oxide to SiO2 is 1:2-1:4, the powder particle size is 20-50nm, and the visible light transmittance is ≥80%.

4. A low VOCs anti-ultraviolet thermal insulation coating composition according to claim 1, characterized in that: The preparation method of the silane coupling agent modified sepiolite is as follows: sepiolite powder and KH560 are mixed in a mass ratio of 10:1, ultrasonically treated at 60° C. for 30 minutes, and dried to obtain the modified sepiolite.

5. The low VOCs anti-ultraviolet thermal insulation coating composition according to claim 1, characterized in that: The added amount of the ultraviolet absorber UV-9 is 0.5-0.7 parts, and the mass ratio of the ultraviolet absorber UV-9 to the nitrogen-doped graphene is 1:3-1:

5.

6. The low VOCs anti-ultraviolet thermal insulation coating composition according to claim 1, characterized in that: The method for preparing the coating composition comprises the following steps: (1) Premixing: Stir water-based acrylic resin, deionized water, and silane coupling agent KH560 at 600 r / min for 10 min; (2) Dispersion: Add nitrogen-doped graphene and nano-ITO-SiO2 composite powder, and perform 40kHz ultrasonic treatment for 30 minutes. The power density of ultrasonic treatment is 0.5-0.8W / mL, and the temperature is controlled at 25-35℃; (3) Blending: Add Poraver®X glass microspheres and modified sepiolite, and high-speed shear at 2000 r / min for 20 min; (4) Conditioning: Add UV absorber UV-9 and hydroxyethyl cellulose, and stir at 400 r / min until uniform; (5) Filtration: Pass through a 200-mesh sieve to obtain the finished coating.

7. A low VOCs anti-ultraviolet thermal insulation coating composition performance testing device, characterized in that: The invention comprises a test assembly (1) and a main control system (2); the test assembly (1) comprises a cylindrical tank (3), and the top of the tank (3) is provided with six ultraviolet spectrometers (9), six infrared thermal imagers (8), six air intake pipes (11) and six gas sensors (10) distributed in a circular array, and the air intake pipes (11) are located between adjacent ultraviolet spectrometers (9) and infrared thermal imagers (8); A door (4) with an observation window is installed on one side of the tank body (3) through a hinge, and a second illumination module (6) is provided on the outer wall of the door (4). Five first illumination modules (5) are distributed in a linear array on the outer wall of the same side of the tank body (3); A mounting groove (12) is provided at one end of the tank body (3), a test area (27) is provided inside the tank body (3), and a bearing and partitioning assembly (7) is installed at the center of the bottom of the test area (27), wherein the bearing and partitioning assembly (7) comprises a lifting and partitioning assembly (13) and a rotating bearing assembly (14).

8. A low-VOCs anti-ultraviolet thermal insulation coating composition performance testing device according to claim 7, characterized in that: The lifting and partitioning assembly (13) comprises a lifting cylinder (24), a guide housing (25) and a partitioning plate (26); The lifting cylinder (24) is fixed to the center of the top of the tank body (3) through a flange, and the guide housing (25) is welded to the top inner wall of the test area (27). A vertical guide rail is provided inside the guide housing (25). The guide housing (25) and the side inner wall of the test area (27) are sealed together by a sealing strip. The partition plate (26) is slidably connected to the guide rail, the top of the partition plate (26) is connected to the piston rod of the lifting cylinder (24) through a coupling, the bottom of the partition plate (26) is provided with a high-temperature resistant rubber sealing strip, and the partition plate (26) and the inner wall of the side of the test area (27) are sealed together through the sealing strip.

9. The low VOCs anti-ultraviolet thermal insulation coating composition performance testing device according to claim 7, characterized in that: The rotating bearing assembly (14) comprises a bearing plate (15), a reduction drive motor (18) and a sample tray assembly; The carrier plate (15) is installed at the bottom center of the test area (27) through a thrust bearing, and six placement grooves (16) are evenly distributed on the surface of the carrier plate (15), and the placement grooves (16) are embedded with tray members (17); The deceleration drive motor (18) is fixed to one side of the inner wall of the installation groove (12) via a bracket, and the output shaft of the deceleration drive motor (18) is connected to the carrier plate (15) via a magnetic coupling coupling.

10. A low VOCs anti-ultraviolet thermal insulation coating composition performance testing device according to claim 9, characterized in that: The tray member (17) comprises an aluminum alloy tray (19), heat-insulating handles (20) are provided on both sides of the top of the aluminum alloy tray (19), a weighing sensor (23) is provided at the bottom of the aluminum alloy tray (19), a supporting plate (21) with a groove is connected above the weighing sensor (23) through a column, and a thermocouple temperature measuring plate (22) is embedded in the center of the supporting plate (21).

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