A method for the micro-fog spray coating of a photonic crystal coating

Abstract

The application discloses a micro-fog spraying preparation method of a photonic crystal coating. The method comprises the following steps: firstly, spraying a primer liquid containing a functional resin on the surface of a plane or a special-shaped substrate after surface treatment; after drying, spraying a water-based photonic crystal latex ball spraying liquid by micro-fog spraying; arranging the latex ball into a three-dimensional photonic crystal structure to obtain a photonic crystal latex ball layer; after heating and curing, spraying a photonic crystal protective layer spraying liquid on the photonic crystal latex ball layer by micro-fog spraying, and curing into a film to form a composite photonic crystal coating. The method can be used for preparing the photonic crystal composite coating with uniform color and thickness, firm structure and excellent substrate adhesion on the surface of a plane or a special-shaped part. The three-dimensional photonic crystal structure contained in the coating can realize the photonic band gap effect on specific wavelengths, so that the coating has the visual performance of iridescence. Meanwhile, the protective layer can realize the wrapping effect on the three-dimensional photonic crystal structure, and improve the mechanical strength and adhesion.

Description

TECHNICAL FIELD

[0001] The present application belongs to the field of photonic crystals, and particularly relates to a micro-fog spraying preparation method of a photonic crystal coating. BACKGROUND

[0002] A photonic crystal is a structure in which different dielectrics are orderly arranged in one dimension, two dimensions or three dimensions. Due to the periodic spatial arrangement, a Bragg scattering effect of light propagation is formed, so that a photonic band gap appears in the process of light propagation. Light falling into the band gap cannot continue to propagate, which is also called a photonic forbidden band. The opal, peacock feather, butterfly wing and sea mouse hair surface in nature can all observe the photonic crystal structure. Due to the excellent photonic forbidden band effect of the three-dimensional photonic crystal structure, the three-dimensional photonic crystal structure exhibits a bright and angle-dependent color change iridescent effect. Therefore, artificially making a three-dimensional photonic crystal structure and using a photonic crystal to replace a chemical color to make decoration become a hot research field.

[0003] From the principle, to form a three-dimensional photonic crystal structure, at least two conditions need to be met: first, an orderly and uniform spatial repeating structure (such as an opal structure or an inverse opal structure); and second, at least two substances with different refractive indexes in the repeating structure. Therefore, preparation of monodisperse small balls and then reassembly become a relatively common method of obtaining a photonic crystal from bottom to top. Among them, the method of preparing inorganic silica small balls and preparing organic polystyrene small balls as the "raw material" of the photonic crystal is the most common.

[0004] The manufacturing method of obtaining a three-dimensional photonic crystal from bottom to top mainly includes vertical deposition, spraying, inkjet, spin coating, coating, dispensing and bending-induced oscillation shearing. In the application field of the photonic crystal for decorative effect, spraying is a manufacturing method with low construction threshold and high efficiency, and is therefore highlighted. However, there are still huge technical difficulties in using the spraying technology to construct a photonic crystal structure to replace a chemical color with a structural color and apply it to the decoration field, which is specifically shown in the following aspects:

[0005] (1) The photonic crystal is a periodic structure of two or more substances with different refractive indexes, and is relatively fragile itself, such as the butterfly wing (organic), the kingfisher feather (organic) and the opal (inorganic) in nature;

[0006] (2) The color of the three-dimensional photonic crystal is seriously dependent on the regularity of arrangement. The more regular the arrangement is, the better the color is presented, and vice versa. The more defects there are, the darker the color is. However, it is very difficult to achieve regular arrangement without defects, especially on curved surfaces and irregular surfaces.

[0007] (3) spray for decoration, the natural need to be sprayed object has similar paint sprayability, especially spray curved surface and special surface requirements more demanding, at the same time in order to adapt to the application environment, need to cooperate with the finishing, primer and other processes, need to withstand the challenge of photonic crystal structure in the construction period of different solvents, different temperature (may come from other layers of the need, such as automobile baking paint process) and other external factors;

[0008] (4) the implementation cost cannot be too high, especially the raw material cost, otherwise it cannot be applied in large area.

[0009] Based on the above difficulties, the idea of using photonic crystal to replace "chemical color" for decoration has been difficult to realize in engineering. SUMMARY

[0010] The purpose of the present application is to provide a kind of photonic crystal coating micro fog spray preparation method.

[0011] The micro fog spray preparation method of the photonic crystal coating is:

[0012] (1) spray primer liquid containing functional resin on the surface of the plane or special-shaped substrate after surface treatment, and dry;

[0013] (2) micro fog spray water-based photonic crystal latex ball spraying liquid, and the latex ball is arranged in three-dimensional photonic crystal structure to obtain photonic crystal latex ball layer;

[0014] (3) heat curing photonic crystal latex ball layer at 60-110 DEG C;

[0015] (4) micro fog spray photonic crystal protective layer spraying liquid on the photonic crystal latex ball layer, and the photonic crystal protective layer spraying liquid is filled and cast under the capillary action of solid-liquid interface, and a dense protective layer is formed by slow evaporation of solvent;

[0016] (5) complete the curing of the protective layer by thermal effect and / or light effect to form a composite photonic crystal coating.

[0017] The substrate is metal, glass or plastic.

[0018] The surface treatment refers to one or more surface treatment operations of oil removal, pickling, alkaline washing, plasma cleaning, sand blasting, electroplating, anodic oxidation and coating.

[0019] The primer liquid containing functional resin is composed of 2-20wt% functional resin, 0-2wt% auxiliary, and the rest is solvent.

[0020] The solvent in the primer liquid is one or more of ethyl acetate, tetrahydrofuran, toluene, dichloromethane, n-hexane, n-butyl ether, petroleum ether and phenyl ether.

[0021] The functional resin is a heat-resistant polymer with aromatic hydrocarbon as the main structure.

[0022] The functional group of the functional resin is one or more of vinyl, acetylene, phenylacetylene, silicon vinyl, silicon hydrogen, alkoxy, alkyl, phenyl.

[0023] The main structure of the aromatic hydrocarbon is one or more of benzene ring, naphthalene, biphenyl, polyphenyl, diphenyl ether, benzene methane, fluorene.

[0024] The atomization pressure of the micro-mist spraying is less than 30 Kpa, the flow rate is less than 20 mL / min, and the nozzle diameter is less than 1 mm. Preferably, the atomization pressure is less than 20 Kpa, the flow rate is less than 15 mL / min, and the nozzle diameter is 0.2-0.8 mm.

[0025] The water-based photonic crystal latex ball spraying liquid is composed of 25-40 wt% monodisperse latex balls, 0.1-2 wt% leveling agent, and the rest is solvent.

[0026] The solvent in the water-based photonic crystal latex ball spraying liquid is selected from one or more of water, isopropanol, ethylene glycol, propylene glycol, glycerol, pentaerythritol, diethylene glycol, triethylene glycol, tetrahydrofuran, formamide, acetamide, N,N-dimethylformamide.

[0027] The photonic crystal latex ball is a polystyrene latex ball, a polymethyl methacrylate latex ball, or an organic core-shell structure latex ball.

[0028] The organic core-shell structure latex ball is a latex ball with polystyrene and polymethyl methacrylate as the core and polymethacrylate and polyacrylate as the shell.

[0029] The particle size of the photonic crystal latex ball is 160-350 nm, the monodisperse index PDI is less than 0.05, and the Zeta charge is -30 mV to -60 mV.

[0030] The water-based photonic crystal latex ball spraying liquid also contains an external field response substance, and the content of the external field response substance is 0.01-30 wt%.

[0031] The external field response substance is one or more of a magnetic field response substance and an electromagnetic wave response substance. The electromagnetic wave includes visible light, infrared, ultraviolet, and microwave.

[0032] The magnetic field response substance is one or more of ferroferric oxide colloidal particles (medical magnetic beads), iron oxide nanometer magnetic powder (superparamagnetic), iron powder, and nickel powder; the infrared response substance is one or more of infrared absorption dyes, anthraquinone dyes, metal disulfide dyes, fluorine dyes, infrared absorption polymers, polythiophene, polyacetylene, polyphenyl, and carbon black; the microwave response substance is one or more of carbon nanotubes, nanometer silicon carbide, nanometer silicon nitride, nanometer iron powder, and nanometer iron oxide; and the ultraviolet response substance is one or more of azobenzene compounds, azobenzene polymers, B vitamins, benzophenone compounds, plasmonic metal nanoparticles (gold, silver, copper, etc.), and fluorescent yellow dyes.

[0033] The photonic crystal protective layer spraying liquid is composed of 20-40 wt% of the organic coating system and the rest of the solvent.

[0034] The organic coating system refers to an organic thin film that can be formed by at least one of thermal effect and light effect.

[0035] The organic coating system is a polyurethane resin system, a silicone system, a polyether system, a polyester system, a polyamide system, or a polysulfide rubber system.

[0036] The organic coating system comprises a main body resin or oligomer, and one or more of a curing agent, a photoinitiator, a light stabilizer, and a monomer matched therewith.

[0037] The solvent in the photonic crystal protective layer spraying liquid is selected from one or more of ethanol, isopropanol, ethylene glycol, propylene glycol, glycerol, pentaerythritol, diethylene glycol, triethylene glycol, formamide, N,N-dimethylformamide, acetone, butanone, methyl isobutyl ketone, cyclohexanone, n-pentane, n-hexane, n-octane, ethyl acetate, and butyl acetate.

[0038] The thickness of the composite photonic crystal coating is 2-50 um, and the thickness of the three-dimensional photonic crystal structure layer is 1-25 um.

[0039] The micro-fog spraying preparation method of the photonic crystal coating can prepare a photonic crystal composite coating with uniform color and thickness, strong structure, and excellent substrate adhesion on the surface of a plane or a special-shaped piece, the three-dimensional photonic crystal structure contained in the photonic crystal composite coating can realize the photonic bandgap effect on specific wavelengths, so that the coating has the visual performance of iridescence; meanwhile, the protective layer can realize the wrapping effect on the three-dimensional photonic crystal structure, so that the photonic crystal composite coating has the mechanical strength of the protective layer and excellent adhesion on the surface of a plane or a special-shaped piece.

[0040] Traditional high pressure air spraying can cause two unavoidable problems when water-based photonic crystal latex ball liquid is deposited on the surface of the substrate: one is the sagging problem caused by low viscosity liquid, which cannot achieve non-planar spraying; two is to solve the sagging problem, use larger atomization pressure spraying, which causes the latex ball to be unable to arrange regularly, and presents amorphous photonic crystal state. The micro-fog spraying adopted by the present application is a low volume low pressure (LVLP) technology of small flow and low atomization pressure of air spraying. The high stall characteristics of micro-fog spraying in atomization make the liquid droplets reduce the rebound effect when reaching the surface, avoid the protective liquid flushing structure, thereby avoiding the generation of photonic crystal defects, compared with the traditional spray gun, the micro-fog spraying can realize 1um coating precision control, improve the color uniformity; for special photonic crystal materials, it has higher material utilization rate; smaller air flow disturbance can minimize the pollution of flying mist, reduce VOC emissions, and at the same time reduce the impact force on the bottom layer, protect the bottom photonic crystal coating from being damaged.

[0041] The special primer prepared in the present application is not to form a strong chemical bond with the photonic crystal and its protective layer to enhance the bonding force, but to form a large number of physical crosslinking points through entanglement. A large number of short chain functional groups, such as vinyl, phenyl, alkoxy, etc., in the primer resin form an entangled network with the photonic crystal and its protective layer (which also has a large number of short chain groups), thereby forming a flexible interface to play a good interface bonding effect, providing the photonic crystal with sufficient mechanical properties. The primer liquid contains heat-resistant polymers mainly composed of aromatic hydrocarbons, so that the primer layer can withstand high temperatures above 300℃.

[0042] The photonic crystal protective layer spraying liquid of the present application is sprayed from the spray gun by micro-fog spraying, and the small droplets stall quickly in the movement, and land on the surface of the three-dimensional photonic crystal layer at a low speed. Compared with high pressure spray gun, the unique weak impact force of micro-fog spraying ensures the three-dimensional close-packed crystal structure of the photonic crystal layer, and avoids the generation of crystal defects. Due to the capillary force of the three-dimensional photonic crystal porous structure, the protective layer spraying liquid penetrates longitudinally in liquid state, and when it penetrates through the entire photonic crystal layer structure, it continues to wet the substrate and the solid-solid interface between the latex ball and the substrate on the substrate surface, thereby playing a bonding effect on the substrate and the latex ball. BRIEF DESCRIPTION OF DRAWINGS

[0043] Figure 1 is the micro-fog spraying manufacturing flow chart of the photonic crystal coating.

[0044] Figure 2 is the digital photo of the glass sample naturally dried after the photonic crystal spraying liquid is sprayed by high pressure spray gun.

[0045] Figure 3 is the digital photo of the glass sample after the photonic crystal protective liquid is sprayed by high pressure spray gun.

[0046] Figure 4 is a digital photo of a photonic crystal spray liquid tested by a rheometer.

[0047] Figure 5 is a digital photo of a liquid photonic crystal spray liquid tested by a rheometer.

[0048] Figure 6 is a digital photo of a photonic crystal spray liquid tested by a rheometer.

[0049] Figure 7 is a digital photo of a photonic crystal glass sample made by micro- fog spray.

[0050] Figure 8 is a scanning electron microscope (SEM) photo of a cross section of a photonic crystal glass sample.

[0051] Figure 9 is a digital photo of a photonic crystal spray irregular shaped car plastic model sample.

[0052] Figure 10 is a digital photo of a photonic crystal spray irregular shaped rod sample.

[0053] Figure 11 is a digital photo of a photonic crystal glass sample.

[0054] Figure 12 is a digital photo of a photonic crystal sample after 100% water boil test without primer treatment.

[0055] Figure 13 is a digital photo of a photonic crystal sample after 100% water boil test with primer treatment. DETAILED DESCRIPTION

[0056] Example 1

[0057] Synthesis of functional resin for primer:

[0058] (1) First step, synthesis or purchase of resins or molecules containing alkyne groups as the main body of aromatic hydrocarbons, including but not limited to the following structures:

[0059] (A) 1,3-diethynylbenzene, purchased from TCI Tiashai (Shanghai) Chemical Industry Development Co., Ltd;

[0060] (B) 1,4-diethynylbenzene, purchased from TCI Tiashai (Shanghai) Chemical Industry Development Co., Ltd;

[0061] (C) 1,3,5-triethynylbenzene, purchased from TCI Tiashai (Shanghai) Chemical Industry Development Co., Ltd;

[0062] (D) 4,4'-diethynylbiphenyl, purchased from TCI (Shanghai) Chemical Industry Co., Ltd.

[0063] (E) Tetra(4-ethynylphenyl)methane, purchased from TCI (Shanghai) Chemical Industry Co., Ltd.

[0064] (F) 2,7-diethynylfluorene, purchased from Zhengzhou Alpha Chemicals Co., Ltd.

[0065] (G) 2,6-diethynyl naphthalene, Sigma-Aldrich (Shanghai) Trading Co., Ltd.

[0066] (H) 1,3,5-tri(4-ethynylphenyl)benzene, purchased from Shanghai Aladdin Bio-Chem Technology Co., Ltd.

[0067] (I) Poly(arylene ethynylene) resin, purchased from the First Research Institute of China Aerospace Industry Corporation.

[0068] (J) Diethynyl diphenyl ether, synthesized in the laboratory.

[0069] 100 mL three-necked flask, equipped with magnetic stirring, reflux condenser, joint with piston, nitrogen ball and stopper. Oxygen was removed by vacuum and nitrogen three times, 70 mL of triethylamine was added from the stopper by syringe, and under nitrogen purging, 6.56 g of dibromodiphenyl ether, 84.24 mg of dichlorobis(triphenylphosphine)palladium, 82.7 mg of cuprous iodide, and 164.7 g of triphenylphosphine were quickly added. After dissolution, nitrogen was bubbled for 20 minutes. Methyl butynol 4 g was added from the stopper by syringe, and heated to 120°C for 12 hours. After the reaction was completed, the filtrate was filtered and dried, dissolved in 50 mL of ethyl acetate, washed with 10% dilute hydrochloric acid and water until neutral, separated and dried with ethyl acetate, and the product was dissolved in 100 mL of toluene, 20 mL of ethylenediamine was added, heated to reflux for 0.5 hours, and a green flocculent precipitate was produced. The precipitate was filtered and the filtrate was washed with 10% dilute hydrochloric acid and water until neutral. The filtrate was dried with anhydrous magnesium sulfate, and after the toluene was removed by spinning, the product was obtained by vacuum drying at 80°C for 4 hours, with a yield of 5.68 g, 85%.

[0070] Sodium hydroxide 3.3 g was dissolved in anhydrous methanol 20 mL, the product from the previous step 2.6 g, toluene 50 mL, and the mixture was stirred in a 100 mL flask. The flask was connected to a water separator, and the oil bath was heated to 110 °C. The mixture was refluxed for 2.5 h. During the reflux, about 20 mL of anhydrous methanol, acetone, and toluene were distilled off. After the reaction was completed, the toluene was removed by rotary evaporation. The product was dissolved in 50 mL of ethyl acetate, washed with water and about 100 mL of 10% dilute hydrochloric acid until neutral. The organic layer was dried over anhydrous magnesium sulfate, and the ethyl acetate was removed by rotary evaporation. The product was recrystallized from n-hexane and dried at 60 °C under vacuum for 4 h. The yield of the product was 1.1 g (65%).

[0071] (K) Diethynyl biphenyl oligomers, synthesized in the laboratory.

[0072] Diethynyl biphenyl was added to carbonyl cobalt in a 40:1 molar ratio in toluene solution under nitrogen protection, and refluxed at 110 °C for 12 h to form diethynyl biphenyl oligomers.

[0073] (2) In the second step, the resin or molecule containing an alkynyl group as the main aromatic hydrocarbon reacts with a molecule or polymer containing silicon of different structures to form a silicon-hybrid resin.

[0074] (A) A 100 mL three-necked flask was equipped with a magnetic stirrer, a reflux condenser, a joint with a piston, a nitrogen balloon, and a stopcock. The flask was deoxygenated by vacuum-pumping and purging with nitrogen three times. Triethynylphenylbenzene (0.945 g, 2.5 mmol) and dry tetrahydrofuran (15 mL) were added to the flask, which was cooled to -30 °C. n-Butyllithium (5 mmol, 2.5 mol / L in n-hexane) was slowly added to the solution, which gradually turned green and turbid. The mixture was stirred for another 3 h, and then diethoxydichlorosilane (0.47 g, 2.5 mmol, Hubei Chengfeng Chemical Co., Ltd.) was slowly added dropwise. The solution gradually turned yellow and transparent. The reaction was continued at room temperature for 12 h. After the reaction was completed, the mixture was extracted with a toluene-water system. The toluene layer was dried over anhydrous magnesium sulfate and dried at 60 °C under vacuum to obtain a yellow solid (1.2 g, 84% yield).

[0075]

[0076] (B) 100 mL three-necked flask, equipped with magnetic stirring, reflux condenser, joint with piston, nitrogen ball and turn-over plug. Vacuum and nitrogen three times to remove oxygen, 1,3,5-triethynylbenzene (0.9 g, 6 mmol, TCI Lai Xie (Shanghai) Chemical Industry Development Co., Ltd.), dry tetrahydrofuran 15 mL, cooling to -30 °C, slowly add n-butyllithium (12 mmol, 2.5 mol / L of n-hexane solution), the solution gradually changed to green turbidity with the addition of butyllithium. The mixture was stirred for 3 h, then slowly drop in diphenyldichlorosilane (1.512 g, 6 mmol), after adding gradually changed into yellow transparent solution. The reaction was warmed to room temperature, continue to react for 12 h. After the reaction was extracted with toluene-water system, after liquid separation, the toluene layer was dried with anhydrous magnesium sulfate, dried at 60 °C under vacuum to obtain yellow sticky 1.9 g (yield 79 %).

[0077]

[0078] (C) 100 mL three-necked flask, equipped with magnetic stirring, reflux condenser, joint with piston, nitrogen ball and turn-over plug. Vacuum and nitrogen three times to remove oxygen, 1,3-diethynylbenzene (0.756 g, 6 mmol, TCI Lai Xie (Shanghai) Chemical Industry Development Co., Ltd.), dry tetrahydrofuran 15 mL, cooling to -30 °C, slowly add n-butyllithium (12 mmol, 2.5 mol / L of n-hexane solution), the solution gradually changed to green turbidity with the addition of butyllithium. The mixture was stirred for 3 h, then slowly drop in methylvinyl dichlorosilane (0.84 g, 6 mmol), after adding gradually changed into orange red transparent solution. The reaction was warmed to room temperature, continue to react for 12 h. After the reaction was extracted with toluene-water system, after liquid separation, the toluene layer was dried with anhydrous magnesium sulfate, dried at 60 °C under vacuum to obtain orange sticky 1.35 g (yield 85 %).

[0079]

[0080] (D) 100 mL three-necked flask, equipped with magnetic stirring, reflux condenser, joint with piston, nitrogen ball and plug. Vacuum and nitrogen three times to remove oxygen, add 4,4'-diethynylbiphenyl (0.756 g, 6 mmol, TCI Lai Xie (Shanghai) Chemical Industry Development Co., Ltd.), dry tetrahydrofuran 20 mL, cooling to -30 ℃, slowly add n-butyllithium (12 mmol, 2.5 mol / L of n-hexane solution), the solution gradually changed to green turbidity with the addition of butyllithium. The mixture was stirred for 3 h, then slowly drop in vinyltrichlorosilane (0.48 g, 3 mmol Shanghai Maikelin Biochemical Technology Co., Ltd.), after adding gradually changed into orange transparent solution. The reaction was warmed to room temperature, continue to react for 12 h. After the reaction was extracted with toluene-water system, after liquid separation, the toluene layer was dried with anhydrous magnesium sulfate, dried at 60 ℃ under vacuum to obtain yellow sticky 1.11 g (yield 90 %).

[0081]

[0082] (E) 100 mL three-necked flask, equipped with magnetic stirring, reflux condenser, joint with piston, nitrogen ball and plug. Vacuum and nitrogen three times to remove oxygen, add diethynyl diphenyl ether (1.308 g, 6 mmol), dry tetrahydrofuran 20 mL, cooling to -30 ℃, slowly add n-butyllithium (12 mmol, 2.5 mol / L of n-hexane solution), the solution gradually changed to green turbidity with the addition of butyllithium. The mixture was stirred for 3 h, then slowly drop in dienyl dichlorosilane (1.08 g, 6 mmol Shanghai Shi Yang Chemical Co., Ltd.), after adding gradually changed into orange transparent solution. The reaction was warmed to room temperature, continue to react for 12 h. After the reaction was extracted with toluene-water system, after liquid separation, the toluene layer was dried with anhydrous magnesium sulfate, dried at 60 ℃ under vacuum to obtain yellow sticky 1.43 g (yield 60 %).

[0083]

[0084] (F) A 100 mL three-necked flask, equipped with a magnetic stirrer, reflux condenser, joint with a piston, nitrogen balloon and a stopper. Vacuum and nitrogen three times to remove oxygen, add 2,6-diethynyl naphthalene (1.056 g, 6 mmol, Sigma-Aldrich (Shanghai) Trading Co., Ltd.), dry tetrahydrofuran 30 mL, and slowly add n-butyllithium (12 mmol, 2.5 mol / L n-hexane solution) at -30°C. The solution gradually turns green turbidity with the addition of butyllithium. Continue to stir the mixture for 3 hours, then slowly add diisopropyl dichlorosilane (1.104 g, 6 mmol, TCI Grace (Shanghai) Chemical Industry Development Co., Ltd.) dropwise. After adding, it gradually turns into a yellow transparent solution. The reaction is warmed to room temperature and continues to react for 12 hours. After the reaction is completed, it is extracted with a toluene-water system, and the toluene layer is dried with anhydrous magnesium sulfate. After drying at 60°C under vacuum, a yellow sticky substance 1.98 g (yield 92%) is obtained.

[0085]

[0086] (G) A 100 mL three-necked flask, equipped with a magnetic stirrer, reflux condenser, joint with a piston, nitrogen balloon and a stopper. Vacuum and nitrogen three times to remove oxygen, add 1,4-diethynylbenzene (0.756 g, 6 mmol, TCI Grace (Shanghai) Chemical Industry Development Co., Ltd.), dry tetrahydrofuran 30 mL, and slowly add n-butyllithium (12 mmol, 2.5 mol / L n-hexane solution) at -30°C. The solution gradually turns green turbidity with the addition of butyllithium. Continue to stir the mixture for 3 hours, then slowly add 2-acetoxyethyl methyl dichlorosilane (1.2 g, 6 mmol, Shanghai Maikelin Biochemical Technology Co., Ltd.) dropwise. After adding, it gradually turns into a light red transparent solution. The reaction is warmed to room temperature and continues to react for 12 hours. After the reaction is completed, it is extracted with a toluene-water system, and the toluene layer is dried with anhydrous magnesium sulfate. After drying at 60°C under vacuum, a red sticky substance 1.56 g (yield 80%) is obtained.

[0087]

[0088] (H) 1,4-diethynylbenzene 1 g (8 mmol), diphenyl dichlorosilane 1.5 g (8.08 mmol), toluene 80 mL and magnesium oxide 3 g are added to a 250 mL single-necked round-bottomed flask. The reaction is completed under nitrogen protection at room temperature (30°C) for 8 h. After the reaction is completed, MgO is removed by filtration and the toluene is dried to obtain a diethynylbenzene and chlorosilane copolymer resin, which is a red viscous liquid at room temperature 2.175 g (yield 87%).

[0089]

[0090] (I) 2,7-Diethynylfluorene (2.14 g 10 mmol, Zhengzhou Alpha Chemical Co., Ltd.), phenyltrichlorosilane 0.846 g (8 mmol), toluene 100 mL and magnesium oxide 5 g were charged into a 250 mL single necked round bottom flask, the reaction was completed under nitrogen protection at room temperature (30 °C) for 8 h with stirring. After the reaction was completed, the MgO was removed by filtration, and the toluene was spin-dried to obtain the diethynylfluorene and chlorosilane copolymer resin, which was a red viscous substance at room temperature (2.09 g, yield 70%).

[0091]

[0092] (J) Tetrakis(4-ethynylphenyl)methane (4.16 g, 10 mmol, TCI TCI (Shanghai) Chemical Industry Development Co., Ltd.), methylhydridopolysilane acetylene (4.15 g, 50 mmol, purchased from the First Research Institute of China Aerospace Science and Industry Corporation), toluene 100 mL and magnesium oxide 5 g were charged into a 250 mL single necked round bottom flask, the reaction was completed under nitrogen protection at room temperature (30 °C) for 8 h with stirring. After the reaction was completed, the MgO was removed by filtration, and the toluene was spin-dried to obtain the polysilane acetylene and tetrakisethynylphenylmethane copolymer resin, which was a red viscous liquid at room temperature, with almost no loss.

[0093]

[0094] (K) Triethynylphenylbenzene 3 g (8 mmol), ethoxypolysilane acetylene (6.912 g, 48 mmol, purchased from the First Research Institute of China Aerospace Science and Industry Corporation), toluene 80 mL and magnesium oxide 3 g were charged into a 250 mL single necked round bottom flask, the reaction was completed under nitrogen protection at room temperature (30 °C) for 8 h with stirring. After the reaction was completed, the MgO was removed by filtration, and the toluene was spin-dried to obtain the polysilane acetylene and triethynylphenylbenzene copolymer resin, which was a red viscous solid at room temperature, with almost no loss.

[0095]

[0096] (L) Polyarylacetylene resin (1 g, 10 mmol, the First Research Institute of China Aerospace Science and Industry Corporation), triethoxysilane (1.64 g, 10 mmol, purchased from the First Research Institute of China Aerospace Science and Industry Corporation), toluene 80 mL and magnesium oxide 3 g were charged into a 250 mL single necked round bottom flask, the reaction was completed under nitrogen protection at room temperature (30 °C) for 8 h with stirring. After the reaction was completed, the MgO was removed by filtration, and the toluene was spin-dried to obtain the polyarylacetylene resin and triethoxysilane copolymer resin, which was a black red viscous fluid at room temperature, with almost no loss.

[0097]

[0098] Table 1 Functional resin for primer coating designation and synthesis yield

[0099] Number Product synthesis yield Number Product synthesis yield Primer A 84％ Primer G 80％ Primer B 79％ Primer H 87％ Primer C 85％ Primer I 70％ Primer D 90％ Primer J 100％ Primer E 60％ Primer K 100％ Primer F 92％ Primer L 100％

[0100] Example 2

[0101] The particle size, monodispersity and ZETA potential of the latex spheres were characterized using a nanoparticle size analyzer (Malvern Zetasizer Nano S90). The solid content was determined, and the theoretical solid content was 35-50 wt%.

[0102] Table 2 Test results of latex sphere performance

[0103]

[0104] Example 3

[0105] The aqueous photonic crystal latex sphere spraying liquid was prepared using the B raw material in Example 2, containing 40% polystyrene latex spheres, 20% diethylene glycol, 0.5% leveling agent, and the rest water; the protective layer spraying liquid contains 20% silicone-modified acrylic resin, and the rest is a mixed solution of n-octane and petroleum ether. In this embodiment and subsequent embodiments, the ratio of photonic crystal spraying liquid and protective liquid is mass.

[0106] The spraying workshop temperature was controlled between 20-25°C, and the humidity was between 40-80 RH%, meeting the standards of the thousand-level dust-free laboratory. The spraying equipment was a spraying robot equipped with a traditional high-pressure spray gun (Yantian Anlieste GFA200S2BX6-10 spray gun, atomization pressure 200 Kpa, flow rate 100-200 mL / min). The substrate was a 300*300mm colorless transparent tempered glass after oil and dust removal treatment. The photonic crystal spraying liquid was sprayed on the clean glass surface in a Z-shaped motion track, and after natural drying, the Figure 2 glass sample shown in FIG. 1 was obtained. The glass sample was dried at 50°C for 30 min, and then the photonic crystal protective liquid was sprayed to obtain the Figure 3 glass sample shown in FIG. 2. The photonic crystal coating structure was completely destroyed under high pressure and high flow impact, and could not present the color effect of photonic crystal.

[0107] Example 4

[0108] The viscosity of the photonic crystal spraying liquid in Example 3 was tested using a rheometer (Anton Paar MCR302) (as shown in FIG. 3). Figure 4 As a comparison, the photonic crystal spraying liquid was laid flat on the test platform, and after natural air drying for 1 h, the spraying liquid presented a colored transparent liquid photonic crystal state (as shown in FIG. 4). Figure 5 Then the viscosity of the liquid photonic crystal was measured, and the data results are shown in Table 3. The viscosity value of the liquid photonic crystal increased by nearly twenty times compared with the photonic crystal spraying liquid in the initial state.

[0109] Table 3 Viscosity test values of photonic crystal spraying liquid in different states

[0110]

[0111] The photonic crystal spraying liquid and the protective layer spraying liquid in Example 3 were used. A micro-fog spraying device (ZhiTuo Robot (Shenzhen) Co., Ltd.) equipped with a PD series micro-flow metering cylinder (flow range between 1 mL and 50 mL / min), a six-axis spraying robot, and a micro-fog spraying gun (DEVILBISS COBRA 3C spraying gun, spraying atomization pressure 20 Kpa, spraying flow 10 mL / min) was used.

[0112] The substrate was the same as in Example 3, i.e., a 300*300 mm colorless transparent tempered glass after oil and dust removal treatment. The photonic crystal spraying liquid was sprayed on the clean glass surface in a Z-shaped motion track, as shown in Figure 6 The lower end of the picture is the initial spraying area, and the upper end is the unfinished spraying area. It can be clearly observed that the initial spraying area in the front section has become a transparent liquid photonic crystal state, and the area corresponding to the spraying gun is milky white liquid. Therefore, through the low-pressure and low-flow drying effect of micro-fog spraying, the spraying liquid can quickly reach a high-viscosity liquid photonic crystal state when deposited on the substrate surface. After spraying, the liquid photonic crystal glass sample was naturally air-dried, then dried at 50°C for 30 min, and finally the photonic crystal protective liquid was sprayed. After 150°C heat curing, the glass sample shown in Figure 7 was obtained. The photonic crystal glass sample presents a uniform green photonic crystal color effect, Figure 8 which is the scanning electron microscope (SEM) photo of the sample.

[0113] Example 5

[0114] The photonic crystal spraying liquid was prepared using the F raw material in Example 2, containing 28% polystyrene latex balls, 10% ethylene glycol, 5% formamide, 2% leveling agent, and the rest being water; the protective layer spraying liquid contains 30% silicone resin, and the rest is 60% ethanol and 10% acetamide.

[0115] The black car plastic model surface was deoiled and flame plasma treated, and then sprayed with colorless transparent water-based acrylic primer material. After drying, a sprayed surface with a contact angle of 46 mN / m was obtained. The photonic crystal spraying liquid and the protective layer were sprayed using the micro-fog spraying equipment in Example 4 (the Microjet-035A spray gun was replaced, the spraying atomization pressure was 15 Kpa, and the spraying flow was 6 mL / min). Motion profiling was used for spraying trajectory design during spraying. After the photonic crystal spraying liquid was sprayed, it was naturally air-dried, then dried at 60°C for 30 min, and finally sprayed with 35% polyurethane petroleum ether photonic crystal protective liquid. After 80°C thermal curing, a Figure 9 photonic crystal plastic model sample as shown in FIG. 6 was obtained.

[0116] Example 6

[0117] The photonic crystal spraying liquid was prepared using the H raw material in Example 3, containing 28% polystyrene-methacrylate latex balls, 10% ethylene glycol, 5% formamide, 2% leveling agent, and the rest was water; the protective layer spraying liquid contained 20% polyurethane acrylate resin, 5% photoinitiator, 5% monomer, and the rest was 20% n-pentane and 50% n-octane.

[0118] The surface of the irregular rod printed with black primer was deoiled and plasma cleaned to obtain a clean printed surface. The photonic crystal spraying liquid and the protective layer were sprayed using the micro-fog spraying equipment in Example 4. Motion profiling was used for spraying trajectory design during spraying. After the photonic crystal spraying liquid was sprayed, it was naturally air-dried, then dried at 80°C for 10 min, and finally sprayed with the photonic crystal protective liquid. After 395 nm wavelength UV-LED light curing, a Figure 10 red photonic crystal irregular part sample as shown in FIG. 7 was obtained.

[0119] Example 7

[0120] The photonic crystal spraying liquid was prepared using the A raw material in Example 2, containing 25% polystyrene latex balls, 1% carboxyl-modified superparamagnetic magnetite magnetic beads (2 μm, laboratory self-made or directly purchased from Thermo Fisher and Agilent), 20% ethylene glycol, 10% formamide, 2% leveling agent, and the rest was water; the protective layer spraying liquid contained 20% polyurethane acrylate resin, 5% photoinitiator, 5% monomer, and the rest was 20% n-pentane and 50% n-octane.

[0121] The substrate is 200*300mm colorless transparent tempered glass after oil and dust removal treatment. The tempered glass is placed in a spraying device that can apply a directional magnetic field environment, for example, an electromagnet is arranged under the spraying sample holder. The photonic crystal spraying liquid is sprayed on the clean glass surface in a Z-shaped motion track. After spraying, the magnetic field is applied when the photonic crystal liquid is not dry. The effect of applying the magnetic field can be judged according to the color and texture of the photonic crystal during the gradual drying process.

[0122] After spraying, the liquid photonic crystal glass sample is naturally air-dried, then dried at 70°C for 30 min, and finally the photonic crystal protective liquid is sprayed. After UV-LED light curing at a wavelength of 395 nm, the glass sample shown in Figure 11 is obtained.

[0123] Example 8

[0124] The photonic crystal spraying liquid is prepared using the G raw material in Example 2. Formula one contains 25% polystyrene-acrylate latex balls, 1% infrared absorber anthraquinone dye (commercially available from Kodak, BASF commercial reagent), 10% ethylene glycol, 2% formamide, 2% leveling agent, and the rest is water. Formula two contains 25% polystyrene-acrylate latex balls, 10% ethylene glycol, 2% formamide, 2% leveling agent, and the rest is water. (The difference between the two formulas is that formula one contains an infrared absorber, and formula two does not). The protective layer spraying liquid contains 20% polysiloxane photosensitive resin, 5% photoinitiator, 5% monomer, and the rest is 20% n-pentane and 50% n-octane.

[0125] The substrate is 150*75mm colorless transparent tempered glass after oil and dust removal treatment. The tempered glass is placed in a spraying device that can apply an infrared light environment. On the clean glass surface, first spray the photonic crystal spraying liquid formula one, and then spray formula two after the whole formula one is sprayed. After spraying the two formulas of photonic crystal spraying liquid, start the infrared device. Since the photonic crystal spraying liquid formula one contains infrared absorbing substances, it can better accept infrared energy. Therefore, photonic crystal arrangements with different upper and lower structures are formed.

[0126] Under the condition that the infrared device is always working, the glass sample after spraying the liquid photonic crystal is desolvated and dried, then dried at 70°C for 10 min, and finally the photonic crystal protective liquid is sprayed. After natural air-drying for 2 min, UV-LED light curing at a wavelength of 395 nm, and then heat curing at 150°C, the glass sample is obtained. Half of the glass is placed in a water bath for water boiling and scribing test, Figure 12The digital photo of the glass sample after boiling water test (80℃*1h), the left side of the picture is the area not soaked in boiling water, and the right side is the area soaked in boiling water. The water resistance of the photonic crystal coating on the glass surface is weak, and the photonic crystal color disappears after boiling test, and the coating presents white color.

[0127] Example 9

[0128] Prepare a 15% ethyl acetate solution using the primer B in Example 1, and the rest of the test is carried out according to Example 8. The sample preparation process is shown in the schematic diagram in Figure 1 .

[0129] Firstly, spray the primer spray liquid, and after the spraying is completed, dry it at 50℃ for 2min, and then repeat the photonic crystal and protective liquid spraying in Example 8. After the photonic crystal protective liquid is sprayed, it is naturally air-dried for 2min, and then it is cured by 395nm UV-LED light, and then it is heat cured at 150℃, to obtain the glass sample. Figure 13 The digital photo of the glass sample after boiling water test (80℃*1h), the left side of the picture is the area not soaked in boiling water, and the right side is the area soaked in boiling water. The water resistance of the photonic crystal coating on the glass surface is weak, and the photonic crystal color disappears after boiling test, and the coating presents white color.

[0130] Example 10

[0131] Prepare an 8% toluene solution using the primer K in Example 1, and prepare a photonic crystal spray liquid using the D raw material in Example 2. Formula one contains 30% polymethyl methacrylate latex balls, 5% beta-nano silicon carbide (less than 100nm, available from InoKem, Merck commercial reagent), 10% ethylene glycol, 10% formamide, 2% leveling agent, and the rest is water; Formula two contains 25% polymethyl methacrylate latex balls, 10% ethylene glycol, 10% formamide, 2% leveling agent, and the rest is water; (the difference between the two formulas is that formula one contains microwave absorbing nano silicon carbide, and formula two does not); the protective layer spray liquid contains 20% polysiloxane resin, and the solvent is n-pentane.

[0132] The substrate is 150*75mm colorless transparent tempered glass after oil and dust removal treatment. Firstly, spray the primer spray liquid, and after the spraying is completed, dry it at 40℃ for 5min, and then place the tempered glass in a spraying device that can apply microwave, or place it in an environment that can generate microwave after the spraying is completed.

[0133] Firstly, the photonic crystal spraying liquid formula 2 is sprayed, and after the whole spraying of the formula 2 is completed, the formula 1 is sprayed, and after the spraying of the formula 1 is completed, the formula 2 is sprayed again, and the spraying is performed for a total of 3 times to form a sandwich structure. After the spraying of the photonic crystal is completed, the microwave device is started, and the microwave input energy is controlled to not make the undried photonic crystal liquid boil, and since the photonic crystal spraying liquid formula 1 contains microwave absorbing substance nano silicon carbide, the microwave energy can be better accepted. The microwave energy input is turned off after the surface drying of the photonic crystal spraying liquid is observed. The whole process is about 30 minutes.

[0134] Then, the photonic crystal protection liquid is sprayed at 70°C for 30 minutes, the microwave device is started again after the spraying is completed, the microwave input energy is controlled to not make the undried protection liquid boil, the microwave device is turned off after the surface drying of the protection liquid, and the glass sample is obtained through 150°C heat curing.

[0135] Example 11

[0136] A 5% tetrahydrofuran solution is prepared using the primer F in Example 1, and a photonic crystal spraying liquid is prepared using the H raw material in Example 1, which contains 30% polystyrene-acrylate latex ball, 2% poly[1-[4-(3-carboxyl-4-hydroxyphenylazo) benzenesulfonylamino]-1,2-ethanediy sodium salt], 10% ethylene glycol, 5% formamide, 2% leveling agent, and the rest is water; the protection layer spraying liquid contains 10% modified acrylic resin, and the solvent is butanol.

[0137] The substrate is 150*75mm colorless transparent tempered glass after oil and dust removal treatment, the primer spraying liquid is sprayed first, and after the thin spraying is completed, the tempered glass is dried at 50°C for 10 minutes, and the tempered glass is placed in a spraying device that can apply ultraviolet light. The photonic crystal spraying liquid is sprayed on the clean glass surface in a Z-shaped motion track. After the spraying, the photonic crystal liquid has been transparent, and the photonic crystal is arranged but not dried (similar Figure 5 state), and the ultraviolet light (LED cold light source) is applied, and the effect of the UV light can be judged according to the color and texture of the photonic crystal in the gradual drying process.

[0138] After the spraying, the liquid photonic crystal glass sample is naturally air-dried (the ultraviolet light source is always kept on during the process), and then dried at 70°C for 30 minutes, and the ultraviolet light source is turned off after the drying.

[0139] Finally, the photonic crystal protection liquid is sprayed, and the photocrystal glass sample is obtained after 120°C heat curing.

[0140] Example 12

[0141] A 5% solution of tetrahydrofuran was prepared using Primer F of Example 1, and a photonic crystal spray solution was prepared using raw materials of G of Example 2, Formula One, containing 40% polystyrene-acrylate latex spheres, 5% vitamin B2 (commercially available from Aldrich), 4% ethylene glycol, 2% formamide, 2% leveling agent, and the rest water; Formula Two, containing 40% polystyrene-acrylate latex spheres, 4% ethylene glycol, 2% formamide, 2% leveling agent, and the rest water; (the difference between the two formulas is that Formula One contains the ultraviolet absorber vitamin B2, and Formula Two does not); the protective layer spray solution contains 20% polysiloxane resin, 5% photoinitiator, 5% monomer, and the rest 20% n-pentane and 50% n-octane.

[0142] The substrate was the same as in Example 2, and a 300*300mm colorless transparent tempered glass after oil and dust removal was prepared. First, the primer spray solution was sprayed, and after the thin spraying was completed, it was dried at 50°C for 10 min. The tempered glass was placed in a spraying device that can apply ultraviolet light, and on the clean glass surface, a Z-shaped motion track was used to first spray the photonic crystal spray solution Formula One, and after the entire Formula One was sprayed, Formula Two was sprayed. After the two formulas of the photonic crystal spray solution were sprayed, the ultraviolet device was started. Since Formula One of the photonic crystal spray solution contains ultraviolet absorbing substances, it can better accept ultraviolet energy.

[0143] Thus, photonic crystal arrangements with different upper and lower structures were formed.

[0144] The glass sample of the sprayed liquid photonic crystal was desolvated and dried at 70°C for 30 min, and finally the photonic crystal protective liquid was sprayed, and after ultraviolet curing, it was heat cured at 150°C to obtain the glass sample.

[0145] Example 13

[0146] An 8% solution of toluene was prepared using Primer K of Example 1, and a photonic crystal spray solution was prepared using raw materials of I of Example 2.

[0147] Formula One, containing 25% polystyrene-methacrylate latex spheres, 1% nano iron oxide (less than 50 nm, laboratory self-made or directly purchased from Thermo Fisher and Agilent commercial nano powder), 20% ethylene glycol, 10% formamide, 2% leveling agent, and the rest water;

[0148] Formula Two, containing 25% polystyrene-methacrylate latex spheres, 1% phycocyanin dye (commercially available from Aldrich or Alpha), 10% ethylene glycol, 2% formamide, 2% leveling agent, and the rest water; (the difference between the two formulas is that Formula One contains the infrared absorber, and Formula Two does not);

[0149] Formula three, containing 25% polystyrene-methyl methacrylate latex ball, 1% nano iron oxide (less than 50nm laboratory self-made or directly purchased nanometer powder of Thermo Fisher, Agilent products), 20% ethylene glycol, 10% formamide, 2% leveling agent, the rest is water;

[0150] The difference between formula one, formula two and formula three is that formula one contains magnetic field response, formula two contains infrared response, and formula three has no external field response.

[0151] The protective layer spraying liquid contains 20% polysiloxane resin, 5% photoinitiator, 5% monomer, and the rest is 20% n-pentane and 50% n-octane.

[0152] The substrate is the same as example 2, a 300*300mm colorless transparent tempered glass after oil and dust removal treatment, first spray the primer spraying liquid, after thin spraying, dry it at 40℃ for 5min, place the tempered glass in the spraying equipment which can apply directional magnetic field and infrared light, spray on the clean glass surface with Z-shaped motion track.

[0153] First spray the photonic crystal spraying liquid formula one, after the whole formula one is sprayed, spray formula two, after formula two is sprayed, spray formula three, a total of 3 times, forming a sandwich structure. After the photonic crystal is sprayed, the photonic crystal solvent volatilizes, the photonic crystal is arranged (similar Figure 5 State), start the magnetic field equipment and infrared light irradiation equipment, the bottom layer of photonic crystal spraying liquid contains magnetic field response, respond to the magnetic field, the middle layer contains infrared absorber, respond to the infrared light. After observing the surface drying of the photonic crystal spraying liquid, turn off the magnetic field and infrared equipment.

[0154] Then dry it at 70℃ for another 30min, finally spray the photonic crystal protective liquid, after ultraviolet curing, heat curing at 150℃, get the glass sample.

Claims

1. A method for preparing a photonic crystal coating by micro-mist spraying, characterized in that, The specific steps of the preparation method are as follows: (1) Spray a primer containing a functional resin onto the surface of a flat or irregularly shaped substrate after surface treatment, and then dry it; (2) A water-based photonic crystal latex ball coating liquid is sprayed with micro-mist, and the latex balls are arranged in a three-dimensional photonic crystal structure to obtain a photonic crystal latex ball layer; (3) Heating and curing the photonic crystal latex sphere layer at 60-110℃; (4) Photonic crystal protective layer spraying liquid is sprayed onto the photonic crystal latex ball layer by micro-mist spraying. The photonic crystal protective layer spraying liquid is filled and cast under the capillary action of the solid-liquid interface, and a dense protective layer is formed by the slow evaporation of the solvent. (5) The protective layer is cured and film-formed through thermal and / or optical effects to form a composite photonic crystal coating; The primer containing the functional resin is composed of 2-20 wt% functional resin, 0-2 wt% additives, and the remainder being solvent; the functional resin is a heat-resistant polymer with aromatic hydrocarbon as the main structure; the functional groups of the functional resin are one or more of the following: vinyl, ethynyl, phenylethynyl, silylvinyl, silanylhydrogen, alkoxy, alkyl, and phenyl. The atomization pressure of the micro-mist spraying is less than 30 kPa, the flow rate is less than 20 mL / min, and the nozzle diameter is less than 1 mm. The aqueous photonic crystal latex ball spray solution consists of 25-40 wt% monodisperse latex balls, 0.1-2 wt% leveling agent, and the remainder is solvent; The photonic crystal protective layer spray liquid is composed of 20-40 wt% organic coating system and the balance solvent; the organic coating system refers to an organic film that can be cured by at least one of thermal and optical effects to form a transparent and robust film.

2. The preparation method according to claim 1, characterized in that, The substrate is metal, glass, or plastic; the surface treatment refers to one or more of the following surface treatment operations: degreasing, pickling, alkaline washing, plasma cleaning, sandblasting, electroplating, anodizing, and coating.

3. The preparation method according to claim 1, characterized in that, The photonic crystal latex spheres are polystyrene latex spheres, polymethyl methacrylate latex spheres, or organic core-shell structured latex spheres.

4. The preparation method according to claim 1, characterized in that, The aqueous photonic crystal latex ball spray liquid also contains an external field responder, with a content of 0.01-30 wt%; the external field responder is one or more of magnetic field responders and electromagnetic wave responders.

5. The preparation method according to claim 1, characterized in that, The thickness of the composite photonic crystal coating is 2-50 μm, wherein the thickness of the three-dimensional photonic crystal structure layer is 1-25 μm.

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