Multifunctional photo-thermal regulation and control composite coating and preparation method and application thereof

Abstract

The invention provides a multifunctional photo-thermal regulated composite coating as well as a preparation method and application thereof. The composite coating comprises a light conversion layer formed on a substrate; the antireflection layer is formed on the light conversion layer; wherein the light conversion layer comprises organic dye with a light conversion function and water-based finish-coat paint; and the antireflection layer comprises hollow SiO2 and water-based finish-coat paint. The composite coating gives consideration to light wavelength conversion, anti-reflection and anti-reflection light wavelength and light intensity regulation and control performance, has heat regulation and control performance for preventing infrared radiation and heat insulation and dustproof performance, and meanwhile shows excellent light conversion attenuation resistance and mechanical stability. In addition, the composite coating is short in preparation process flow, simple and convenient to operate and suitable for large-scale production, and can be used for preparing films and glass for agricultural greenhouses to promote plant growth.

Description

Technical Field

[0001] The present invention belongs to the technical field of functional composite coatings, and specifically comprises a multifunctional photothermal control composite coating and its preparation method and application. Background Art

[0002] As one of the cleanest and most abundant renewable energy sources, solar energy directly or indirectly influences most physical and chemical reactions on Earth, including photosynthesis and the circulation of water and air in the atmosphere. Research has found that only about 10% of sunlight is used for photosynthesis, primarily in the blue-violet region of 400-500nm and the red-orange region of 600-700nm. Ultraviolet light is not only detrimental to photosynthesis but can also cause plant diseases and pests, while yellow-green light is largely reflected by plant leaves. Therefore, in agricultural production, the use of materials with photoconversion capabilities to control light wavelength is crucial for improving solar energy utilization.

[0003] The introduction of light-conversion functional materials will have a certain impact on the light transmittance of the film or coating, and the light reflection occurring on the surface of the film or coating will also reduce the transmittance of sunlight. If an anti-reflection and anti-transmittance layer is introduced on the surface of the light-converting film or coating, it may be helpful in reducing surface light reflection, increasing light transmittance and improving sunlight utilization. However, there are relatively few studies on the application of dual-functional composite coatings of light conversion and anti-reflection to agricultural production materials (such as films for agricultural greenhouses and glass for agricultural greenhouses). This part of the research mainly focuses on solar concentrators. However, due to the relatively small size of solar concentrators, the requirements for the synthesis route for preparing dual-functional composite coatings are not high. However, in fact, the synthesis route is relatively cumbersome and not yet suitable for large-scale production. Therefore, it is not conducive to the development of composite coatings in agricultural production materials.

[0004] Furthermore, given the long-term outdoor use of agricultural production materials, their surfaces are prone to dust absorption and adhesion, making them difficult to clean. This, in turn, reduces sunlight utilization. Thermal insulation is also a key concern for agricultural production materials. Therefore, to meet today's application needs, it is urgent to develop a multifunctional coating that meets the requirements of agricultural production materials while simultaneously providing light conversion, anti-reflection and anti-transmittance, dust prevention, and thermal insulation. Summary of the Invention

[0005] To address the aforementioned issues with existing technologies, the first objective of the present invention is to provide a multifunctional composite coating for photothermal regulation. This composite coating exhibits wavelength conversion, anti-reflection and anti-transmittance capabilities, dust prevention and removal capabilities, thermal insulation, excellent mechanical stability, and light conversion and attenuation resistance. It can be used to prepare films and glass for agricultural greenhouses to promote plant growth.

[0006] The second object of the present invention is to provide a method for preparing the composite coating as described above. The preparation method provided by the present invention has a short process flow, is simple to operate, is easy to synthesize, and is suitable for large-scale production.

[0007] The third object of the present invention is to provide an application of the composite coating described above in the preparation of agricultural greenhouse films and agricultural greenhouse glass.

[0008] To achieve the above first purpose, the technical solution adopted by the present invention includes:

[0009] The present invention discloses a multifunctional light-heat-regulating composite coating, which comprises

[0010] a light conversion layer formed on a substrate; and

[0011] an anti-reflection and anti-reflection layer formed on the light conversion layer;

[0012] Wherein, the light conversion layer includes an organic dye with light conversion function and a water-based topcoat;

[0013] The anti-reflection and anti-transmission layer comprises hollow SiO2 and water-based topcoat.

[0014] In the present invention, in order to solve the problems existing in the prior art, the inventors selected a light conversion layer solution prepared by mixing an organic dye with a light conversion function with a water-based transparent topcoat. The light conversion layer prepared by using the light conversion layer solution can provide the substrate with light wavelength conversion capability. By adjusting the type of light conversion organic dye used and the ratio of each raw material in the light conversion layer solution, the ultraviolet light or green light in the sunlight can be efficiently converted into blue light or red light, thereby improving the utilization rate of sunlight and promoting plant growth and development. Hollow SiO2 is selected and mixed with the water-based topcoat to prepare an anti-reflection and anti-transmission layer. The hollow SiO2 provides a low refractive index, and a nanostructured anti-reflection layer with a gradient refractive index is prepared. layer to achieve anti-reflection and anti-reflection properties, wherein the water-based topcoat serves as a matrix to adhere and anchor the hollow SiO2, making the prepared anti-reflection layer more stable; based on the hollow structure of the hollow SiO2 and its infrared absorption in the wavelength range of 7-14μm, it can provide certain thermal insulation properties; in addition, the low surface energy of the water-based topcoat combined with the micro-nano rough surface of the anti-reflection coating reduces the binding force of large particles of dust on the surface of the anti-reflection and anti-reflection layer, so that the composite coating has dust-proof properties, and under the action of external mechanical force, the accumulated dust can be easily removed. Therefore, the composite coating prepared by the present invention has light wavelength conversion, light intensity regulation, thermal regulation and dust-proof properties.

[0015] The wavelength of light can be converted by selecting different organic dyes. In a specific embodiment, the organic dye is selected from one or more of 7-diethylamino-4-methylcoumarin, 7-hydroxy-4-methylcoumarin, 7-amino-4-chloromethylcoumarin, 7-amino-4-methylcoumarin, coumarin 480D, 2,2'-(4-4'-distyryl)bisbenzoxazole, 1,4-bis(benzoxazolyl-2-yl)naphthalene, BASF Lumogen F Red 305, BASF Lumogen F Red 300, Sumiplast RedHFG Solvent Red 149 and fluorescein.

[0016] Furthermore, the water-based topcoat serves as a coating matrix and has the properties of being waterproof, weather-resistant, color-retaining, having strong adhesion, and not cracking. It can effectively disperse and fix organic dyes and hollow SiO2 to prepare a highly transmittance, uniform light-conversion layer and an anti-reflection and transmittance-enhancing layer. It can be selected from one of flat topcoat, silicone-acrylic topcoat, and fluorocarbon topcoat; for example, one of FA03 (silicone-acrylic flat topcoat) of Yunnan Aipuwei Paint Co., Ltd., FA02 (flat topcoat) of Yunnan Aipuwei Paint Co., Ltd., UTI-F7 (silicone-acrylic topcoat) of Changshu Youdeai Paint Co., Ltd., and UTI-F8 (fluorocarbon topcoat) of Changshu Youdeai Paint Co., Ltd.

[0017] The hollow SiO2 used in the present invention is self-made, and the method of the paper (ACS Nano, 2010, 4(7), 4308-4316) can be referred to. Its particle size is 80-150nm, with an average particle size of about 110nm, the wall thickness is 20-40nm, with an average wall thickness of about 20nm, and the inner cavity size is 30-120nm, with an average size of about 70nm.

[0018] To achieve the above second purpose, the technical solutions adopted by the present invention include:

[0019] The present invention discloses a method for preparing the multifunctional photothermal control composite coating as described above, comprising the following steps:

[0020] 1) Prepare the light conversion layer solution

[0021] Dissolving an organic dye with a light conversion function in a solvent and mixing it with a water-based topcoat in a certain proportion to obtain a light conversion layer solution;

[0022] 2) Prepare anti-reflection and anti-reflection layer solution

[0023] Mixing hollow SiO2, water and water-based topcoat to obtain an anti-reflection and anti-transmission layer solution;

[0024] 3) Preparation of light conversion layer

[0025] Immerse the pretreated substrate in the light conversion layer solution, pull it, and dry it at 40-60° C. for 5-30 minutes to obtain a light conversion layer;

[0026] Alternatively, the light conversion layer solution is coated on a pretreated substrate and then dried at 40-60° C. for 5-30 minutes to obtain a light conversion layer;

[0027] 4) Preparation of anti-reflection and anti-reflection layer

[0028] The substrate with the light conversion layer is immersed in the anti-reflection and anti-reflection layer solution, pulled, and then dried at 40-60°C for 2-10 minutes to obtain a multifunctional light-thermal control composite coating with anti-reflection and anti-reflection, light conversion, heat preservation and dust prevention.

[0029] Alternatively, the anti-reflection and anti-reflection layer solution is coated on a film substrate with a light conversion layer, and then dried at 40-60° C. for 2-10 minutes to obtain a multifunctional light-heat-regulating composite coating with anti-reflection and anti-reflection, light conversion, heat preservation, and dust prevention.

[0030] During the preparation process, the methods used to prepare the light conversion layer and the anti-reflection and anti-reflection layer can be the same or different, that is, when the light conversion layer is formed by pulling, the anti-reflection and anti-reflection layer can be formed by pulling or coating. Conversely, when the light conversion layer is formed by coating, the anti-reflection and anti-reflection layer can also be formed by pulling or coating; the coating is selected from brushing or spraying.

[0031] Furthermore, the mass ratio of the organic dye, solvent and aqueous topcoat in the light conversion layer solution is 0.005-0.05:15-25:5-10; illustratively, the mass ratio of the organic dye, solvent and aqueous topcoat in the light conversion layer solution can be 0.005-0.05:20:5-10, 0.005-0.05:15-25:8, 0.005-0.05:20:8, 0.005-0.01:20:8, 0.005-0.02:20:8, 0.005-0.03:20:8, 0.005-0.04:20:8, etc.

[0032] Further, the mass ratio of hollow SiO2, water and water-based topcoat in the anti-reflection and anti-reflection layer solution is 0.1-0.8:15-20:0.2-2; illustratively, the mass ratio of hollow SiO2, water and water-based topcoat in the anti-reflection and anti-reflection layer solution can be 0.1:15-20:0.2-1.5, 0.2:15-18:0.2-1.5, 0.3:16-20:0.5-1.5, 0.4:15-20:0.5-1, 0.5:15-20:1-1.5, 0.6:15-18:0.5-1.5, 0.7:15-20:0.2-1, 0.8:18:0.5-1.25, etc.

[0033] Furthermore, the solvent in step 1 is selected from one or more of water, ethanol and acetone.

[0034] Furthermore, the specific steps of the pulling process in step 3 are:

[0035] The pretreated substrate is immersed in the light conversion layer solution, and after each immersion of 10-60 seconds, it is pulled once at a rate of 20-100 mm / min, and then dried at 40-60° C. for 5-30 minutes, and pulled 1-6 times in total to obtain a light conversion layer.

[0036] Furthermore, the pulling conditions in step 3 are: after soaking for 10-30 seconds, pulling once at a rate of 50-100 mm / min, and then drying at 40-60° C. for 5-30 minutes, for a total of 2-4 pulling times.

[0037] Furthermore, the specific steps of the pulling process in step 4 are:

[0038] The substrate with the light-converting layer is immersed in the anti-reflection and anti-reflection layer solution. After soaking for 10-90 seconds, it is pulled once at a speed of 50-200 mm / min, and then dried at 40-60°C for 5-30 minutes to obtain a multifunctional light-thermal control composite coating with anti-reflection and anti-reflection, light conversion, heat preservation and dust prevention.

[0039] Furthermore, the pulling conditions in step 4 are: after soaking for 30-60 seconds, pulling once at a rate of 150-200 mm / min, and then drying at 40-60° C. for 5-30 minutes.

[0040] Furthermore, the substrate is pretreated in the following steps:

[0041] Place the substrate in water, ethanol and acetone solutions in sequence, ultrasonically clean for 10-30 minutes, blow dry with high-purity nitrogen, and then clean with oxygen plasma for 5-15 minutes before use;

[0042] The material of the substrate is selected from one of polyethylene, polypropylene, polyethylene terephthalate, polybutylene terephthalate, polymethyl methacrylate, polycarbonate, polyurethane, polyvinyl chloride, ethylene-vinyl acetate copolymer, architectural glass, and photovoltaic glass.

[0043] Furthermore, the thickness of the prepared light conversion layer is 1-6 μm; the thickness of the anti-reflection and anti-transmission layer is 120-250 nm; and the thickness of the composite coating is 1.12-6.25 μm.

[0044] To achieve the third objective above, the technical solutions adopted by the present invention include:

[0045] The present invention discloses an application of the multifunctional light-heat-regulated polymer film described above in the preparation of agricultural greenhouse films and agricultural greenhouse glass.

[0046] Beneficial effects of the present invention:

[0047] The present invention discloses a multifunctional photothermal control composite coating, which has the following advantages over the prior art:

[0048] 1. The present invention discloses for the first time a multifunctional composite coating that can achieve light conversion, anti-reflection and anti-reflection, thermal insulation, and dust prevention. The coating exhibits excellent light conversion gain, light conversion attenuation resistance, and mechanical stability. After mechanical friction, immersion in acid rain simulation fluid, water immersion, high temperature and high humidity, and natural light exposure, it maintains good light conversion and anti-reflection effects. The composite coating comprises a light conversion layer and an anti-reflection and anti-reflection layer. The light conversion layer can effectively absorb ultraviolet and / or green light from sunlight by adding one or more light-converting organic dyes and convert it into blue and / or red light, achieving effective conversion of the incident spectrum. The anti-reflection and anti-reflection layer is prepared by adhering hollow SiO2 to the light conversion layer using a water-based transparent topcoat. Compared to a single light conversion layer, the resulting composite coating can reduce surface light reflection by approximately 4% and achieve approximately 10% light conversion gain, effectively improving sunlight utilization. Furthermore, the composite coating exhibits approximately 11.6% infrared blocking efficiency and dust prevention compared to a blank substrate.

[0049] 2. The water-based topcoat is green and environmentally friendly, easy to use, has strong adhesion, does not crack, has excellent protective properties, is waterproof and dustproof, and provides excellent performance for the composite coating prepared by the present invention; a water-based transparent topcoat is selected as a matrix to mix and disperse organic dyes with light conversion functions to avoid fluorescence aggregation and quenching of organic dyes, and to prepare a transparent and uniform light-conversion layer; for the anti-reflection and transmittance-enhancing layer, a water-based transparent topcoat is used as a matrix, which can enhance the adhesion between the hollow SiO2 and the light-conversion layer, improve the coverage of the hollow SiO2 and the mechanical stability of the anti-reflection layer; based on the low surface energy of the water-based topcoat and the rough structure of the anti-reflection layer, a dust-proof and dust-removable surface is obtained.

[0050] In summary, the multifunctional photothermal control composite coating prepared by the present invention has good light conversion, anti-reflection and anti-transmittance, dust prevention and thermal insulation properties, and the composite coating has good light conversion anti-attenuation and mechanical stability; by adjusting the selection of light-converting organic dyes, different proportions of light conversion effects can be achieved to meet various application needs; generally speaking, the preparation method of the composite coating is simple, has low equipment requirements, is applicable to different substrates, is suitable for large-scale production, and has a wide range of applications. BRIEF DESCRIPTION OF THE DRAWINGS

[0051] Figure 1 The UV-visible light transmittance of the polyethylene film with the composite coating prepared in Example 1, the polyethylene film with only the light conversion layer prepared in Comparative Example 1, and a blank polyethylene film are compared.

[0052] Figure 2 The solar radiation flux density is compared between the polyethylene film with the composite coating prepared in Example 1, the polyethylene film with only the light conversion layer prepared in Comparative Example 1, and a blank polyethylene film.

[0053] Figure 3 The UV-visible light transmittance of the polyethylene film with the composite coating prepared in Example 2, the polyethylene film with only the light conversion layer prepared in Comparative Example 2, and a blank polyethylene film are compared.

[0054] Figure 4 The solar radiation flux density of the polyethylene film with the composite coating prepared in Example 2, the polyethylene film with only the light conversion layer prepared in Comparative Example 2, and a blank polyethylene film are compared.

[0055] Figure 5 The UV-visible light transmittance of the polyethylene film with only the light conversion layer prepared in Comparative Example 2, the polyethylene film with the composite coating prepared in Comparative Example 3, and a blank polyethylene film are compared.

[0056] Figure 6 The UV-visible light transmittance of the glass with the composite coating prepared in Example 3, the glass with only the light conversion layer prepared in Comparative Example 4, and a blank glass are compared.

[0057] Figure 7 The solar radiation flux density is compared among the glass with the composite coating prepared in Example 3, the glass with only the light conversion layer prepared in Comparative Example 4, and blank glass.

[0058] Figure 8 The mechanical strength test of the composite coating obtained in Example 3 was performed, wherein: Figure 8 Where a is the pencil hardness; b is the "X" test.

[0059] Figure 9 The changes in light transmittance and light conversion performance of the composite coating in Example 3 after 5000 times of 3M tape adhesion treatment, 50000 times of pressure friction treatment, 60 days of 60°C / 80% RH treatment, 60 days of deionized water immersion, 60 days of pH 3.0 acid rain simulation liquid immersion, and 60 days of natural light exposure.

[0060] Figure 10 The dustproof performance of blank glass, the glass plate with composite coating of Example 3 and the glass plate with only light conversion layer of Comparative Example 4 is compared.

[0061] Figure 11 The light transmittance of the blank glass with dust deposited thereon, the glass with the composite coating of Example 3, and the glass with only the light-converting layer of Comparative Example 4 after mechanical dust removal is compared.

[0062] Figure 12 The heat insulation performance test comparison of the glass plate with the composite coating obtained in Example 3 and the glass plate with only the light conversion layer obtained in Comparative Example 4 is shown.

[0063] Figure 13 The UV-visible light transmittance of the polyethylene film with the composite coating prepared in Example 4, the polyethylene film with only the light conversion layer prepared in Comparative Example 5, and a blank polyethylene film are compared.

[0064] Figure 14 The solar radiation flux density is compared between the polyethylene film with the composite coating prepared in Example 4, the polyethylene film with only the light conversion layer prepared in Comparative Example 5, and a blank polyethylene film.

[0065] Figure 15 IR spectra of the polyethylene film with composite coating and blank polyethylene film obtained in Example 4.

[0066] Figure 16 The following are photos comparing the growth of plants in the blank polyethylene film, the polyethylene films of Example 4 and the comparative example 5 at different growth time periods in the plant growth experiment.

[0067] Figure 17In the plant growth experiment, the fresh weight of the above-ground part and the fresh weight of the underground part of the plants in the blank polyethylene film, the polyethylene films of Example 4 and Comparative Example 5 were compared after 18 days of cultivation. DETAILED DESCRIPTION

[0068] To more clearly illustrate the present invention, the present invention is further described below in conjunction with preferred embodiments and accompanying drawings. It should be understood that the embodiments described are only some embodiments of the present invention, not all embodiments. All other embodiments obtained by persons of ordinary skill in the art based on the embodiments of the present invention without inventive effort are within the scope of protection of the present invention.

[0069] In addition, unless otherwise specified, the raw materials used in the present invention can be obtained commercially, and any range recorded in the present invention includes the end value and any numerical value between the end values ​​and any sub-range formed by the end value or any numerical value between the end values.

[0070] Any range described in the present invention includes the end value and any numerical value between the end values ​​and any sub-range formed by the end value or any numerical value between the end values.

[0071] The water-based transparent finishing paints used in the embodiments and comparative examples of the present invention are all commercially available products.

[0072] Example 1

[0073] This embodiment provides a method for preparing a multifunctional composite coating on a polyethylene substrate that is anti-reflective, converts blue light, prevents dust, and keeps warm. The specific preparation steps are as follows:

[0074] 1) 7-diethylamino-4-methylcoumarin, ethanol, and FA02 matte finish oil from Yunnan Aipuwei Paint Co., Ltd. were mixed in a mass ratio of 0.001:4:1.6, and after ultrasonic debubbling, a light conversion layer solution was obtained and set aside;

[0075] 2) Weigh and mix homemade hollow SiO2, deionized water, and FA02 matte topcoat produced by Yunnan Aipuwei Paint Co., Ltd. in a mass ratio of 0.4:19:1, and mix them by ultrasonic mixing to obtain an anti-reflection and anti-reflection layer solution for later use;

[0076] 3) A polyethylene film (2 x 7 cm) was ultrasonically cleaned with water, ethanol, and acetone for 10 min, respectively, then dried with high-purity nitrogen gas and cleaned with oxygen plasma for 10 min before use.

[0077] 4) placing the pretreated polyethylene film in the light conversion layer solution prepared in step 1), soaking the film for 30 seconds, pulling the film at a rate of 50 mm / min, and drying the film at 60° C. for 10 minutes, for a total of four pulling cycles, to obtain a light conversion layer;

[0078] 5) placing the polyethylene substrate with the light-converting layer in the anti-reflection and anti-transmittance layer solution in step 2), soaking for 30 seconds, pulling once at a rate of 200 mm / min, and then drying at 60°C for 10 minutes to finally obtain an anti-reflection, blue light conversion, dust-proof, and heat-insulating multifunctional composite coating on the polyethylene substrate, the thickness of the composite coating being 4.12 μm.

[0079] Comparative Example 1

[0080] This comparative example provides a method for preparing a blue light-converting coating on a polyethylene substrate, and the specific implementation steps are as follows:

[0081] 1) 7-diethylamino-4-methylcoumarin, ethanol, and FA02 matte finish oil from Yunnan Aipuwei Paint Co., Ltd. were mixed in a mass ratio of 0.001:4:1.6, and after ultrasonic debubbling, a light conversion layer solution was obtained and set aside;

[0082] 2) A polyethylene film (2 x 7 cm) was ultrasonically cleaned with water, ethanol, and acetone for 10 min, then dried with high-purity nitrogen and cleaned with oxygen plasma for 10 min before use.

[0083] 3) placing the pretreated polyethylene film in the light conversion layer solution prepared in step 1), soaking for 30 seconds, pulling the film once at a rate of 50 mm / min, and then drying the film at 60° C. for 10 minutes, for a total of four pulling cycles, to obtain a light conversion layer.

[0084] Performance Testing

[0085] Figure 1 The transmittance of the polyethylene film with a composite coating obtained in Example 1 and the polymer film containing only a light conversion layer obtained in Comparative Example 1 were compared with that of a polyethylene film without any coating (referred to as blank polyethylene film). The results showed that the polyethylene film containing only a light conversion layer had obvious absorption in the ultraviolet region (<400nm), while the transmittance of the polyethylene film with a composite coating in the range of 380nm-1500nm was 3% higher on average than that of the polyethylene film containing only a light conversion layer.

[0086] Figure 2 In order to test the solar radiation flux density of different polyethylene films under sunlight using the handheld plant lighting spectrum detector UPRtek PG-200N, the light conversion layer of comparative example 1 has ultraviolet-to-blue light conversion performance, and its light conversion efficiency is 42.6%; the composite coating of Example 1 not only has ultraviolet-to-blue light conversion performance, but also improves the transmittance of the polyethylene film in the range of 400-800nm. Compared with the light conversion layer, its transmittance in the range of 400-800nm ​​increases by an average of 4%, and the light conversion efficiency is increased to 87.1%, indicating that the composite coating has the effects of light conversion and anti-reflection and anti-transmittance.

[0087] Example 2

[0088] This embodiment provides a method for preparing a multifunctional composite coating on a polyethylene substrate that is anti-reflective, converts red light, prevents dust, and keeps warm. The specific implementation steps are as follows:

[0089] 1) Mix BASF Lumogen F Red 305, ethanol, and UTI-F7 silicone acrylic overprint varnish (produced by Changshu Youdeai Coatings Co., Ltd.) in a mass ratio of 0.001:4:1.6, remove bubbles by ultrasonication, and obtain a light conversion layer solution for later use;

[0090] 2) Weigh and mix homemade hollow SiO2, deionized water, and UTI-F7 silicone acrylic varnish from Changshu Youdeai Coating Co., Ltd. in a mass ratio of 0.4:18:0.5, and ultrasonically mix to obtain an anti-reflection and anti-reflection layer solution for later use;

[0091] 3) A polyethylene film (2 x 7 cm) was ultrasonically cleaned with water, ethanol, and acetone for 10 min, respectively, then dried with high-purity nitrogen gas and cleaned with oxygen plasma for 10 min before use.

[0092] 4) placing the pretreated polyethylene film in the light conversion layer solution prepared in step 1), soaking the film for 10 seconds, pulling the film once at a rate of 100 mm / min, and then drying the film at 60° C. for 10 minutes, for a total of three pulling cycles, to obtain a light conversion layer;

[0093] 5) placing the polyethylene film with the light-converting layer in the anti-reflection and anti-transmittance layer solution in step 2), soaking for 60 seconds, pulling once at a rate of 200 mm / min, and then drying at 60°C for 10 minutes to finally obtain a multifunctional composite coating with anti-reflection, red light conversion, dustproofness, and heat preservation on the polyethylene substrate, wherein the thickness of the composite coating is 3.16 μm.

[0094] Comparative Example 2

[0095] This comparative example provides a method for preparing a red light-converting coating on a polyethylene substrate, and the specific implementation steps are as follows:

[0096] 1) Mix BASF Lumogen F Red 305, ethanol, and UTI-F7 silicone acrylic overprint varnish (produced by Changshu Youdeai Coatings Co., Ltd.) in a mass ratio of 0.001:4:1.6, remove bubbles by ultrasonication, and obtain a light conversion layer solution for later use;

[0097] 2) A polyethylene film (2 x 7 cm) was ultrasonically cleaned with water, ethanol, and acetone for 10 min, then dried with high-purity nitrogen and cleaned with oxygen plasma for 10 min before use.

[0098] 3) placing the pretreated polyethylene film in the light conversion layer solution prepared in step 1), soaking for 10 seconds, pulling the film once at a rate of 100 mm / min, and then drying the film at 60° C. for 10 minutes, for a total of three pulling cycles, to obtain a light conversion layer.

[0099] Comparative Example 3

[0100] This comparative example provides a method for preparing a composite coating on a polyethylene substrate, and the specific implementation steps are as follows:

[0101] 1) Mix BASF Lumogen F Red 305, ethanol, and UTI-F7 silicone acrylic overprint varnish (produced by Changshu Youdeai Coatings Co., Ltd.) in a mass ratio of 0.001:4:1.6, remove bubbles by ultrasonication, and obtain a light conversion layer solution for later use;

[0102] 2) Weigh and mix homemade hollow SiO2, deionized water, and UTI-F7 silicone acrylic varnish from Changshu Youdeai Coating Co., Ltd. in a mass ratio of 1:18:1, and ultrasonically mix to obtain an anti-reflection and anti-reflection layer solution for later use;

[0103] 3) A polyethylene film (2 x 7 cm) was ultrasonically cleaned with water, ethanol, and acetone for 10 min, respectively, then dried with high-purity nitrogen gas and cleaned with oxygen plasma for 10 min before use.

[0104] 4) placing the pretreated polyethylene film in the light conversion layer solution prepared in step 1), soaking the film for 10 seconds, pulling the film at a rate of 100 mm / min, and drying the film at 60° C. for 10 minutes, for a total of three pulling cycles, to obtain a light conversion layer;

[0105] 5) placing the polyethylene film with the light conversion layer in the anti-reflection and anti-reflection layer solution in step 2), soaking for 60 seconds, pulling once at a rate of 200 mm / min, and then drying at 60° C. for 10 minutes to finally obtain a composite coating on the polyethylene substrate.

[0106] Performance Testing

[0107] Figure 3 The transmittance of the polyethylene film with a composite coating obtained in Example 2 and the polyethylene film containing only a light conversion layer obtained in Comparative Example 2 were compared with that of a polyethylene film without any coating (referred to as blank polyethylene film). The results showed that the polyethylene film containing only a light conversion layer had obvious absorption in the green light region (500-600nm), while the transmittance of the polyethylene film with a composite coating in the range of 380nm-1500nm was 3% higher on average than that of the film with only a light conversion layer.

[0108] Figure 4In order to test the solar radiation flux density of different polyethylene films under sunlight using the handheld plant lighting spectrum detector UPRtek PG-200N, the light conversion layer of Comparative Example 2 has green light to red light performance, and its light conversion efficiency is 39.5%; the composite coating of Example 2 not only has green light to red light performance, but also improves the transmittance of the polyethylene film in the range of 400-800nm. Compared with the light conversion layer, the average transmittance of the composite coating in the range of 400-800nm ​​increases by about 4%, and the light conversion performance is improved to 75.5%, indicating that the composite coating has the effects of light conversion and anti-reflection and anti-transmittance.

[0109] Figure 5 The transmittance of the polyethylene film with a composite coating obtained in Comparative Example 3, the polyethylene film containing only a light conversion layer obtained in Comparative Example 2, and a blank polyethylene film are compared. The results show that the transmittance of the composite coating obtained by using the anti-reflection and transmittance-enhancing layer solution prepared using the ratio in Comparative Example 3 is about 5% lower on average than the transmittance of only the light conversion layer.

[0110] Example 3

[0111] This embodiment provides a method for preparing a multifunctional composite coating on a glass substrate that is anti-reflective, converts blue / red light, is dust-proof, and has thermal insulation properties. The specific implementation steps are as follows:

[0112] 1) Mix BASF Lumogen F Red 305, 7-diethylamino-4-methylcoumarin, ethanol, and Yunnan Aipuwei Coatings Co., Ltd.'s FA03 silicone-acrylic flat topcoat in a mass ratio of 0.01:0.04:20:8, and remove bubbles by ultrasonication to obtain a blue / red coating solution for later use;

[0113] 2) hollow SiO2, deionized water and FA03 silicone acrylic flat topcoat produced by Yunnan Aipuwei Paint Co., Ltd. were mixed in a mass ratio of 0.4:19:1, and ultrasonically mixed to obtain an anti-reflection and anti-reflection layer solution for later use;

[0114] 3) An optical glass plate (2 × 7 cm) was ultrasonically cleaned with water, ethanol, and acetone for 10 min, then dried with high-purity nitrogen and cleaned with oxygen plasma for 10 min before use.

[0115] 4) placing the prepared glass plate in the light conversion layer solution prepared in step 1), soaking for 10 seconds, pulling the plate once at a rate of 50 mm / min, and then drying the plate at 60° C. for 10 minutes, for a total of three pulling cycles, to obtain a light conversion layer;

[0116] 5) placing the glass substrate with the light-converting layer in the anti-reflection and anti-reflection layer solution in step 2), soaking for 30 seconds, pulling once at a rate of 200 mm / min, and then drying at 60°C for 10 minutes to finally obtain a multifunctional composite coating on the glass substrate with anti-reflection, blue / red light conversion, dust-proof, and heat-insulating properties, wherein the thickness of the composite coating is 3.20 μm.

[0117] Comparative Example 4

[0118] This comparative example provides a method for preparing a blue / red light-converting coating on a glass substrate, and the specific implementation steps are as follows:

[0119] 1) Mix BASF Lumogen F Red 305, 7-diethylamino-4-methylcoumarin, ethanol, and Yunnan Aipuwei Coatings Co., Ltd.'s FA03 silicone-acrylic flat topcoat in a mass ratio of 0.01:0.04:20:8, and remove bubbles by ultrasonication to obtain a blue / red coating solution for later use;

[0120] 2) Ultrasonic cleaning of optical glass plates with water, ethanol, and acetone for 10 minutes, followed by drying with high-purity nitrogen gas and oxygen plasma cleaning for 10 minutes before use;

[0121] 3) The prepared glass plate was placed in the light conversion solution prepared in step 1), and was pulled once at a rate of 50 mm / min after soaking for 10 seconds, and then dried at 60° C. for 10 minutes, and pulled a total of 3 times to obtain a light conversion layer.

[0122] Performance Testing

[0123] Figure 6 The light transmittance of the glass plate with the composite coating obtained in Example 3, the glass plate with only the light conversion layer obtained in Comparative Example 4, and the glass plate without any coating (referred to as blank glass) was compared. The results show that the glass with the light conversion layer has significant absorption in the ultraviolet (<400nm) and green light regions (500-600nm), while the light transmittance of the glass with the composite coating in the range of 380-1500nm is an average of 4% higher than the light transmittance of the film with only the light conversion layer.

[0124] Figure 7 In order to test the solar radiation flux density of different glass plates under sunlight using the handheld plant lighting spectrum detector UPRtek PG-200N, the light conversion layer in Comparative Example 4 has the ability to absorb ultraviolet and green light and convert it into blue and red light. The composite coating in Example 3 not only has the ability to convert ultraviolet and green light into blue and red light, but also improves the solar radiation intensity of the glass plate in the range of 400-800nm, indicating that the composite coating has the effects of light conversion and anti-reflection and anti-transmittance.

[0125] Figure 8a and b are the mechanical strengths of the composite coating obtained in Test Example 3, wherein a is the pencil hardness, indicating that the composite coating has a pencil hardness of 3H; and b is an “X” test, indicating that the composite coating has a 5A-level adhesion.

[0126] Figure 9 The changes in light transmittance and light conversion performance of the composite coating in Example 3 after being subjected to 5000 times of 3M tape adhesion treatment, 50000 times of pressure friction treatment (100kPa), and being placed in a constant temperature and humidity chamber at a temperature of 60°C and a relative humidity of 80% for 60 days, soaked in deionized water for 60 days, soaked in pH 3.0 acid rain simulation liquid for 60 days, and exposed to natural light for 60 days; it shows that the composite coating has good light conversion anti-attenuation and mechanical stability.

[0127] Figure 10 The dustproof performance of blank glass, the glass plate with the composite coating of Example 3 and the glass plate with only the light-converting layer of Comparative Example 4 was compared. It was found that the composite coating prepared in Example 3 had certain dustproof performance compared with the blank glass and the light-converting layer of Comparative Example 4.

[0128] Figure 11 The light transmittance of the blank glass with dust deposited on it, the glass plate with the composite coating of Example 3, and the glass plate with only the light conversion layer of Comparative Example 4 after mechanical dust removal; after mechanical vibration dust removal, the light transmittance of the composite coating of Example 3 can still maintain the same light transmittance as the original composite coating, while the light transmittance of the blank glass and the sample of Comparative Example 4 decreases significantly, indicating that the composite coating can effectively remove dust under simple mechanical external force.

[0129] Figure 12 The thermal insulation performance of the glass plate with the composite coating obtained in Example 3 and the glass plate with only the light conversion layer obtained in Comparative Example 4 was tested. After 1 minute of infrared heating, the glass with the composite coating in Example 3 showed an average temperature barrier of about 4°C.

[0130] Example 4

[0131] This embodiment provides a method for preparing a multifunctional composite coating on a large-sized polyethylene substrate that is anti-reflective, converts blue / red light, prevents dust, and keeps warm. The specific implementation steps are as follows:

[0132] 1) BASF Lumogen F Red 305, 7-diethylamino-4-methylcoumarin, ethanol, and FA03 silicone-acrylic flat topcoat from Yunnan Aipuwei Paint Co., Ltd. were mixed in a mass ratio of 0.01:0.03:20:8, and after ultrasonic debubbling, a light conversion layer solution was obtained and set aside;

[0133] 2) Mix homemade hollow SiO2, deionized water, and FA03 silicone acrylic flat topcoat produced by Yunnan Aipuwei Paint Co., Ltd. in a mass ratio of 0.4:19:1, and mix them evenly by ultrasonic mixing to obtain an anti-reflection and anti-reflection layer solution for later use;

[0134] 3) Ultrasonic cleaning of a 13 cm x 9 cm polyethylene film with water, ethanol, and acetone for 10 minutes, followed by drying with high-purity nitrogen and oxygen plasma cleaning for 15 minutes before use;

[0135] 4) placing the pretreated polyethylene film in the light conversion layer solution prepared in step 1), soaking the film for 10 seconds, pulling the film at a rate of 50 mm / min, and drying the film at 60° C. for 15 minutes, for a total of three pulling cycles, to obtain a light conversion layer;

[0136] 5) placing the polyethylene film with the light-converting layer in the anti-reflection and anti-reflection layer solution in step 2), soaking for 30 seconds, pulling once at a rate of 200 mm / min, and then drying at 60° C. for 20 minutes to finally obtain a multifunctional composite coating with anti-reflection, blue / red light conversion, dustproofness, and heat preservation on a large-sized polyethylene substrate, wherein the thickness of the composite coating is 3.20 μm.

[0137] Comparative Example 5

[0138] This comparative example provides a method for preparing a blue / red light-converting coating on a large-sized polyethylene substrate, and the specific implementation steps are as follows:

[0139] 1) BASF Lumogen F Red 305, 7-diethylamino-4-methylcoumarin, ethanol, and FA03 silicone-acrylic flat topcoat from Yunnan Aipuwei Paint Co., Ltd. were mixed in a mass ratio of 0.01:0.03:20:8, and after ultrasonic debubbling, a light conversion layer solution was obtained and set aside;

[0140] 2) Ultrasonic cleaning of a 13 cm x 9 cm polyethylene film with water, ethanol, and acetone for 10 minutes, followed by drying with high-purity nitrogen and oxygen plasma cleaning for 15 minutes before use;

[0141] 3) placing the pretreated polyethylene substrate in the light conversion solution prepared in step 1), soaking for 10 seconds, pulling the substrate once at a rate of 50 mm / min, and then drying the substrate at 60° C. for 15 minutes, for a total of three pulling cycles, to obtain a light conversion layer.

[0142] Performance Testing

[0143] Figure 13The light transmittance of the polyethylene film with a composite coating obtained in Example 4, the polyethylene film containing only a light conversion layer obtained in Comparative Example 5, and a blank polyethylene film is compared. The results show that the polyethylene film containing only a light conversion layer has obvious absorption in the ultraviolet (<400nm) and green light regions (500-600nm), while the light transmittance of the polyethylene film with a composite coating in the range of 380-1500nm is 3% higher on average than that of the film with only a light conversion layer.

[0144] Figure 14 In order to test the solar radiation flux density of different polyethylene films under sunlight using the handheld plant lighting spectrometer UPRtek PG-200N, the light conversion layer has the ability to absorb ultraviolet and green light and convert it into blue and red light. The composite coating not only has the ability to convert ultraviolet and green light into blue and red light, but also has a blue light conversion efficiency of 6.89% and a red light conversion efficiency of 36.86%. Compared with the polyethylene film with only a light conversion layer coating, it actually has a light conversion gain of about 10%; it also improves the transmittance of the polyethylene film in the range of 400-800nm. Compared with the light conversion coating, the average transmittance in the range of 400-800nm ​​increases by 4%, indicating that the composite coating has the effects of light conversion and anti-reflection and anti-transmittance, effectively improving the utilization rate of sunlight.

[0145] Figure 15 The infrared spectra of the polyethylene film with the composite coating and the blank polyethylene film obtained in Example 4 show that the composite coating has an infrared blocking efficiency of about 11.6% relative to the blank polyethylene film.

[0146] Plant growth experiment

[0147] The polyethylene film with the multifunctional composite coating in Example 4, the polyethylene film containing only the light conversion layer in Comparative Example 5, and a blank polyethylene film were tested for promoting the growth of lettuce. The specific implementation steps are as follows:

[0148] 1) Selecting eight sheets of the polyethylene film with the multifunctional composite coating prepared in Example 4, the polyethylene film containing only a light-converting layer in Comparative Example 5, and a blank polyethylene film, the films of the same type were spliced ​​together using hot melt adhesive to obtain three 13 cm × 55 cm films;

[0149] 2) Place the film from step 1) 3 cm under a full-spectrum LED light, with the LED light 30 cm from the top of the plant;

[0150] 3) Cultivate the plants in soil at a temperature of 15-25°C with 14 hours of light per day for 18 days, and observe the growth of the plants.

[0151] Figure 16The photos are of plants growing in the polyethylene film with a multifunctional composite coating in Example 4, the polyethylene film with only a light-converting layer in Comparative Example 5, and a blank polyethylene film in different growth time periods; the results show that the growth height of plants cultured in the polyethylene film with a multifunctional composite coating is significantly better than that of the other two groups.

[0152] Figure 17 After 18 days of cultivation, the above-ground fresh weight and underground fresh weight of the plants in the polyethylene film with a multifunctional composite coating in Example 4, the polyethylene film containing only a light conversion layer in Comparative Example 5, and the blank polyethylene film were weighed; the results showed that the above-ground fresh weight and underground fresh weight of the plants in the polyethylene film with a multifunctional composite coating were higher than those in the other two groups, indicating that cultivating plants in a multifunctional polyethylene film can significantly promote the growth and development of plants.

[0153] Obviously, the above embodiments of the present invention are merely examples for clearly illustrating the present invention, and are not limitations on the implementation methods of the present invention. For ordinary technicians in the relevant field, other different forms of changes or modifications can be made based on the above description. It is impossible to list all the implementation methods here. All obvious changes or modifications derived from the technical solution of the present invention are still within the scope of protection of the present invention.

Claims

1. A multifunctional photothermal control composite coating, characterized in that: The composite coating comprises a light conversion layer formed on a substrate; as well as an anti-reflection and anti-reflection layer formed on the light conversion layer; Wherein, the light conversion layer includes an organic dye with light conversion function and a water-based topcoat; The anti-reflection and anti-transmission layer comprises hollow SiO2 and water-based topcoat.

2. The composite coating according to claim 1, characterized in that The organic dye is selected from one or more of 7-diethylamino-4-methylcoumarin, 7-hydroxy-4-methylcoumarin, 7-amino-4-chloromethylcoumarin, 7-amino-4-methylcoumarin, coumarin 480D, 2,2'-(4-4'-distyryl)bisbenzoxazole, 1,4-bis(benzoxazolyl-2-yl)naphthalene, BASF Lumogen FRed 305, BASF Lumogen F Red 300, Sumiplast Red HFG Solvent Red 149 and fluorescein; The water-based finishing paint is selected from one of flat finishing oil, silicone acrylic finishing paint, and fluorocarbon finishing paint; Preferably, the water-based topcoat is selected from FA03 and FA02 of Yunnan Aipuwei Paint Co., Ltd. and UTI-F7 and UTI-F8 of Changshu Youdeai Paint Co., Ltd.

3. The composite coating according to claim 1, characterized in that The particle size of the hollow SiO2 is 80-150nm, the wall thickness is 20-40nm, and the inner cavity size is 30-120nm.

4. The method for preparing a composite coating according to any one of claims 1 to 3, wherein: The steps include: 1) Prepare the light conversion layer solution Dissolving an organic dye with a light conversion function in a solvent and mixing it with a water-based topcoat in a certain proportion to obtain a light conversion layer solution; 2) Prepare anti-reflection and anti-reflection layer solution Mixing hollow SiO2, water and water-based topcoat to obtain an anti-reflection and anti-transmission layer solution; 3) Preparation of light conversion layer Immerse the pretreated substrate in the light conversion layer solution, pull it, and dry it at 40-60° C. for 5-30 minutes to obtain a light conversion layer; Alternatively, the light conversion layer solution is coated on a pretreated substrate and then dried at 40-60° C. for 5-30 minutes to obtain a light conversion layer; 4) Preparation of anti-reflection and anti-reflection layer The substrate with the light conversion layer is immersed in the anti-reflection and anti-reflection layer solution, pulled, and then dried at 40-60°C for 2-10 minutes to obtain a multifunctional light-thermal control composite coating with anti-reflection and anti-reflection, light conversion, heat preservation and dust prevention. Alternatively, the anti-reflection and anti-reflection layer solution is coated on a film substrate with a light conversion layer, and then dried at 40-60° C. for 2-10 minutes to obtain a multifunctional light-heat-regulating composite coating with anti-reflection and anti-reflection, light conversion, heat preservation, and dust prevention.

5. The preparation method according to claim 4, characterized in that The mass ratio of the organic dye, the solvent and the water-based topcoat in the light conversion layer solution is 0.005-0.05:15-25:5-10.

6. The preparation method according to claim 4, characterized in that The mass ratio of hollow SiO2, water and water-based topcoat in the anti-reflection and anti-transmission layer solution is 0.1-0.8:15-20:0.2-2.

7. The preparation method according to claim 4, characterized in that The specific steps of the pulling process in step 3 are: The pretreated substrate is immersed in the light conversion layer solution, and after each immersion of 10-60 seconds, it is pulled once at a rate of 20-100 mm / min, and then dried at 40-60° C. for 5-30 minutes, and pulled 1-6 times in total to obtain a light conversion layer.

8. The preparation method according to claim 4, characterized in that The specific steps of the pulling process in step 4 are: The substrate with the light-converting layer is immersed in the anti-reflection and anti-reflection layer solution. After soaking for 10-90 seconds, it is pulled once at a speed of 50-200 mm / min, and then dried at 40-60°C for 5-30 minutes to obtain a multifunctional light-thermal control composite coating with anti-reflection and anti-reflection, light conversion, heat preservation and dust prevention.

9. The preparation method according to claim 4, characterized in that The steps of pre-treating the substrate are as follows: Place the substrate in water, ethanol and acetone in sequence, ultrasonically clean for 10-30 minutes, blow dry with high-purity nitrogen, and then clean with oxygen plasma for 5-15 minutes before use; The material of the substrate is selected from one of polyethylene, polypropylene, polyethylene terephthalate, polybutylene terephthalate, polymethyl methacrylate, polycarbonate, polyurethane, polyvinyl chloride, ethylene-vinyl acetate copolymer, architectural glass, and photovoltaic glass.

10. Use of the composite coating according to any one of claims 1 to 3 in the preparation of agricultural greenhouse films and agricultural greenhouse glass.

Images