Infrared barrier polyurethane coating and preparation method thereof

Abstract

The invention discloses an infrared barrier polyurethane coating and a preparation method thereof, and relates to the technical field of coatings. When the infrared barrier polyurethane coating is prepared, 7-cyano-8-hydroxy-1, 6-naphthyridine and pent-4-enohydrazide are subjected to a reaction, and a pentenyl triazole monomer is prepared; polymerizing a pentenyl triazole monomer and hexenyl ethylene carbonate, and coating the cesium tungsten bronze powder with the polymerized pentenyl triazole monomer and hexenyl ethylene carbonate to prepare modified cesium tungsten bronze powder; reacting the cardanol diglycidyl ether with carbon dioxide to obtain cyclic carbonated cardanol; the cyclic carbonated cardanol, the modified cesium tungsten bronze powder, functional microspheres, cyclohexanone, isophorone diamine and 1, 3-bis (3-aminopropyl)-1, 1, 3, 3-tetramethyldisiloxane are uniformly mixed, and the infrared barrier polyurethane coating is prepared. The infrared barrier polyurethane coating prepared by the invention has excellent flame retardance, aging resistance and infrared barrier property.

Description

Technical Field

[0001] The present invention relates to the technical field of coatings, in particular to an infrared blocking polyurethane coating and a preparation method thereof. Background Art

[0002] Glass curtain wall buildings utilize extensive glass materials, which have a high thermal conductivity. Especially during my country's persistently hot summer and autumn climate, direct sunlight penetrates indoor spaces, causing temperatures to rise rapidly and forcing people to rely on refrigeration equipment to maintain a comfortable temperature. This high energy consumption not only increases energy consumption but also has significant negative environmental impacts. To effectively achieve thermal insulation, it is necessary to block infrared radiation, which carries a high amount of radiation. While blocking infrared radiation, good visible light transmittance is also necessary to ensure good indoor lighting.

[0003] Thermal insulation coatings can effectively absorb, scatter or reflect infrared light, while also having good visible light transmittance, and have great potential in reducing building energy consumption. Existing thermal insulation coatings are mostly made by mixing inorganic thermal insulation materials (such as tin-doped indium oxide, tin-doped antimony oxide, and lanthanum hexaboride) or organic thermal insulation materials (such as anthraquinone dyes, cyanines and metal complexes, and polyaniline) with a matrix resin. Long-term exposure to light can easily lead to aging problems such as yellowing, powdering, shedding, and decreased transparency. The coating contains a large amount of flammable components such as organic matter and resin, which poses certain safety risks during use. Therefore, it is very necessary to improve the aging resistance and flame retardant properties of thermal insulation coatings. Summary of the Invention

[0004] The purpose of the present invention is to provide an infrared blocking polyurethane coating and a preparation method thereof, so as to solve the problems existing in the prior art.

[0005] In order to solve the above technical problems, the present invention provides the following technical solutions: An infrared blocking polyurethane coating is provided. The infrared blocking polyurethane coating is prepared by polymerizing pentenyltriazole monomer and hexenyl ethylene carbonate to coat cesium tungsten bronze powder to obtain modified cesium tungsten bronze powder; reacting cardanol diglycidyl ether and carbon dioxide to obtain cyclocarbonated cardanol; and uniformly mixing cyclocarbonated cardanol, modified cesium tungsten bronze powder, functional microspheres, cyclohexanone, isophoronediamine, and 1,3-bis(3-aminopropyl)-1,1,3,3-tetramethyldisiloxane to obtain the infrared blocking polyurethane coating. The pentenyltriazole monomer is prepared by reacting 7-cyano-8-hydroxy-1,6-naphthyridine and pent-4-enoylhydrazide; The cyclic carbonated cardanol is prepared by reacting cardanol diglycidyl ether and carbon dioxide; The functional microspheres are prepared by reacting 1,4-phenylenebis(phosphorus oxychloride) and intermediate 2; The intermediate 2 is prepared by reacting the intermediate 1 with 2-(5-hydroxy-3-oxo-2,3-dihydro-1H-indole-1-ethyl)malononitrile; The intermediate 1 is prepared by oxidizing N1,N1-di(4-aminophenyl)aniline with potassium peroxymonosulfonate.

[0006] A method for preparing an infrared-blocking polyurethane coating, comprising the following steps: (1) 1,4-phenylenebis(phosphorus dichloride), intermediate 2, and acetonitrile were mixed uniformly in a mass ratio of 1:(3-3.2):(40-42), and ultrasonically dispersed for 20-30 min. Under stirring conditions of 20-30 ° C and 300-400 r / min, 0.2-0.3 times the mass of intermediate 2 triethylamine was added dropwise at a uniform rate within 15 min. After the addition was completed, the reaction was continued with stirring for 2-3 h, centrifuged, washed with anhydrous ethanol and deionized water 3-5 times each, and dried at 50-60 ° C under vacuum conditions for 12-14 h to obtain functional microspheres; (2) Pentenyltriazole monomer, hexenyl ethylene carbonate, azobisisobutyronitrile, and m-xylene are mixed evenly in a mass ratio of 1:(1~1.2):(0.03~0.05):(24~26) to prepare a reaction solution; the reaction solution is divided into two parts, one of which accounts for 1 / 5 of the total mass of the reaction solution; cesium tungsten bronze powder and 1 / 5 of the reaction solution are mixed evenly in a mass ratio of 1:(22~24), stirred at 70~76℃ and 200~300r / min for 40~50min, and the remaining reaction solution is added dropwise at a uniform speed within 25min. After the addition is completed, the reaction is continued to stir for 3~4h, filtered, washed with anhydrous ethanol 3~5 times, and dried at 76~80℃ under vacuum conditions for 9~11h to obtain modified cesium tungsten bronze powder; (3) Cyclocarbonated cardanol, modified cesium tungsten bronze powder, functional microspheres, cyclohexanone, isophorone diamine, and 1,3-bis(3-aminopropyl)-1,1,3,3-tetramethyldisiloxane are mixed evenly to prepare an infrared blocking polyurethane coating.

[0007] As an optimization, the CAS number of 1,4-phenylenebis(phosphorus dichloride) in step (1) is 1227269-53-5, and the structural formula is .

[0008] As an optimization, the preparation method of the intermediate 2 in step (1) is as follows: intermediate 1 and 2-(5-hydroxy-3-oxo-2,3-dihydro-1H-indole-1-ethyl)malononitrile are added in a molar ratio of 1:2 to anhydrous ethanol 20 to 22 times the mass of the intermediate, and dichloromethane 20 to 22 times the mass of the intermediate 1 is added, and the mixture is stirred at 10 to 30°C and 200 to 300 r / min for 20 to 30 minutes, and the anhydrous ethanol and dichloromethane are removed by rotary evaporation to obtain intermediate 2; the CAS number of the 2-(5-hydroxy-3-oxo-2,3-dihydro-1H-indole-1-ethyl)malononitrile is 121506-94-3, and the structural formula is: .

[0009] As an optimization, the preparation method of the intermediate 1 is as follows: N1,N1-bis(4-aminophenyl)aniline and dichloromethane are uniformly mixed in a mass ratio of 1:(6-8), and an oxidant solution with a mass of 10 to 12 times that of N1,N1-bis(4-aminophenyl)aniline is added dropwise at a uniform rate over 10 minutes at 0°C and 200 to 300 r / min of stirring conditions. The temperature is raised to 20 to 30°C, and the stirring reaction is continued for 9 to 11 minutes. Dichloromethane with a volume of 2 to 3 times that of the oxidant solution is added and mixed uniformly, and the mixture is allowed to stand for stratification. The organic phase is dried at 50 to 60°C under vacuum conditions for 3 to 4 hours to obtain intermediate 1.

[0010] As an optimization, the reaction process of the intermediate 1 and intermediate 2 is as follows: .

[0011] As an optimization, the preparation method of the oxidant solution is: potassium peroxymonosulfonate and deionized water are uniformly mixed in a mass ratio of 1:(3~4) to prepare the oxidant solution.

[0012] As an optimization, the particle size of the cesium tungsten bronze powder in step (2) is 80 nm, which is purchased from Wuhan Kemik Biomedical Technology Co., Ltd.

[0013] As an optimization, the preparation method of the pentenyltriazole monomer in step (2) is as follows: 7-cyano-8-hydroxy-1,6-naphthyridine and pent-4-enoylhydrazide are added in a molar ratio of 1:1 to 1,6-dioxane with a mass of 10 to 12 times that of 7-cyano-8-hydroxy-1,6-naphthyridine, and sodium methoxide with a mass of 0.04 to 0.06 times that of 7-cyano-8-hydroxy-1,6-naphthyridine is added, and the mixture is stirred at 80 to 90°C and 200 to 300 r / min for 3 to 4 hours, and dried at 50 to 60°C under vacuum conditions for 7 to 8 hours to obtain the pentenyltriazole monomer; the CAS number of the 7-cyano-8-hydroxy-1,6-naphthyridine is 797788-20-6, and the structural formula is The CAS number of the pent-4-enoyl hydrazide is 86538-23-0; the structural formula is .

[0014] As an optimization, the reaction process of the pentenyltriazole monomer is as follows: .

[0015] As an optimization, the CAS number of the hexenyl ethylene carbonate in step (2) is 130727-29-6, and the structural formula is .

[0016] As an optimization, the preparation method of the cyclic carbonated cardanol in step (3) is as follows: cardanol diglycidyl ether, anhydrous ethanol and tetrabutylammonium bromide are uniformly mixed in a mass ratio of 1:(4~5):(0.04~0.06), placed in a high-pressure reactor, and carbon dioxide gas is introduced to maintain the pressure at 2~2.2 MPa. The mixture is stirred at 80~90°C and 300~500 r / min for 3~4 hours. After cooling to room temperature, the mixture is discharged and dried at 50~60°C under vacuum conditions for 6~8 hours to obtain cyclic carbonated cardanol.

[0017] As an optimization, the epoxy value of the cardanol diglycidyl ether is 0.2-0.28, which was purchased from Hubei Yamade Biopharmaceutical Co., Ltd.

[0018] As an optimization, the amounts of cyclocarbonated cardanol, modified cesium tungsten bronze powder, functional microspheres, cyclohexanone, isophorone diamine, and 1,3-bis(3-aminopropyl)-1,1,3,3-tetramethyldisiloxane in step (3) are as follows: by mass: 30-32 parts of cyclocarbonated cardanol, 2-3 parts of modified cesium tungsten bronze powder, 4-5 parts of functional microspheres, 30-40 parts of cyclohexanone, 4-5 parts of isophorone diamine, and 4-5 parts of 1,3-bis(3-aminopropyl)-1,1,3,3-tetramethyldisiloxane.

[0019] Compared with the prior art, the present invention has the following beneficial effects: In the preparation of the infrared blocking polyurethane coating, the present invention comprises the following steps: oxidizing N1,N1-di(4-aminophenyl)aniline with potassium peroxymonosulfonate to obtain an intermediate 1; reacting the intermediate 1 with 2-(5-hydroxy-3-oxo-2,3-dihydro-1H-indole-1-ethyl)malononitrile to obtain an intermediate 2; reacting 1,4-phenylenebis(phosphoryl dichloride) with the intermediate 2 to obtain functional microspheres; and reacting 7-cyano-8-hydroxy-1,6-naphthyridine with pent-4-enoylhydrazide to obtain a functional microsphere. A pentenyltriazole monomer is obtained; the pentenyltriazole monomer and hexenyl ethylene carbonate are polymerized and coated on cesium tungsten bronze powder to obtain modified cesium tungsten bronze powder; cardanol diglycidyl ether and carbon dioxide are reacted to obtain cyclocarbonated cardanol; the cyclocarbonated cardanol, modified cesium tungsten bronze powder, functional microspheres, cyclohexanone, isophoronediamine, and 1,3-bis(3-aminopropyl)-1,1,3,3-tetramethyldisiloxane are uniformly mixed to obtain an infrared blocking polyurethane coating.

[0020] First, N1,N1-bis(4-aminophenyl)aniline was oxidized with potassium peroxymonosulfonate to obtain intermediate 1; intermediate 1 was reacted with 2-(5-hydroxy-3-oxo-2,3-dihydro-1H-indole-1-ethyl)malononitrile to form an acceptor-donor-acceptor structure conjugated molecule, namely intermediate 2; the P-Cl bond on 1,4-phenylenebis(phosphorus dichloride) was reacted with the hydroxyl group on intermediate 2 to prepare functional microspheres, and phosphorus element and acceptor-donor-acceptor conjugated structure were introduced into the functional microspheres; the acceptor-donor-acceptor conjugated structure has enhanced overlap between the highest occupied orbital and the lowest unoccupied orbital, can strongly absorb near-infrared light, and improve the infrared blocking performance of the infrared blocking polyurethane coating; the introduction of phosphorus element can improve the flame retardant properties of the infrared blocking polyurethane coating.

[0021] Secondly, 7-cyano-8-hydroxy-1,6-naphthyridine and pent-4-enoylhydrazide are reacted to obtain pentenyltriazole monomer; pentenyltriazole monomer and hexenyl ethylene carbonate are polymerized and coated on cesium tungsten bronze powder to obtain modified cesium tungsten bronze powder; cyclic carbonate groups and triazole derivative structures are introduced into the modified cesium tungsten bronze powder, and the hydroxyl groups and triazoles on the triazole derivative structure can chelate to form a hydrogen bond six-membered ring. The hydrogen bond six-membered ring is unstable. Under the action of ultraviolet light, the hydrogen bonds in the molecule will be broken, and the molecular structure will be stabilized by releasing energy to the outside world, converting ultraviolet light energy into heat energy release, thereby improving the anti-aging performance of infrared blocking polyurethane coating; modified cesium tungsten The cyclic carbonate groups introduced on the bronze powder can react with the amino groups on the curing agent isophoronediamine and 1,3-bis(3-aminopropyl)-1,1,3,3-tetramethyldisiloxane to form carbamate bonds, which participate in the curing of polyurethane coatings. Cesium tungsten bronze nanoparticles have become very attractive near-infrared blocking materials due to their excellent optical properties. The near-infrared absorption performance brought about by the surface plasmon resonance and electron transition (migration) of the nanoparticles has strong absorption capacity in the near-infrared wavelength range and good transmittance in the visible light wavelength range, further improving the infrared blocking performance of infrared blocking polyurethane coatings.

[0022] Finally, the epoxy group on the diglycidyl ether of cardanol is reacted with carbon dioxide to obtain cyclocarbonated cardanol; the cyclocarbonated cardanol, modified cesium tungsten bronze powder, functional microspheres, cyclohexanone, isophoronediamine, and 1,3-bis(3-aminopropyl)-1,1,3,3-tetramethyldisiloxane are evenly mixed to obtain an infrared-blocking polyurethane coating; the cyclocarbonate group on the carbonated cardanol can react with the curing agent isophoronediamine and the amino group on 1,3-bis(3-aminopropyl)-1,1,3,3-tetramethyldisiloxane to generate a non-isocyanate polyurethane coating, and the siloxane structure on 1,3-bis(3-aminopropyl)-1,1,3,3-tetramethyldisiloxane can promote carbonization during combustion to form a dense barrier layer, further improving the flame retardant properties of the infrared-blocking polyurethane coating. DETAILED DESCRIPTION

[0023] The following will be combined with the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the embodiments described are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0024] The particle size of the cesium tungsten bronze powder used in the following examples and comparative examples is 80 nm and was purchased from Wuhan Kemik Biopharmaceutical Technology Co., Ltd.; the epoxy value of the cardanol diglycidyl ether used is 0.2-0.28 and was purchased from Hubei Yamade Biopharmaceutical Co., Ltd.

[0025] Example 1: A method for preparing an infrared-blocking polyurethane coating, comprising the following steps: (1) Potassium peroxymonosulfate and deionized water were mixed in a mass ratio of 1:3 to prepare an oxidant solution; N1, N1-di(4-aminophenyl) aniline and dichloromethane were mixed in a mass ratio of 1:6 to prepare an oxidant solution; at 0 ° C, 200 r / min stirring conditions, 10 times the mass of N1, N1-di(4-aminophenyl) aniline oxidant solution was added dropwise at a constant rate over 10 minutes, the temperature was raised to 20 ° C, and the stirring reaction was continued for 11 minutes, and dichloromethane 2 times the volume of the oxidant solution was added and mixed evenly, and the mixture was allowed to stand for stratification. The organic phase was dried at 50 ° C under vacuum conditions for 4 hours to prepare intermediate 1; intermediate 1, 2-(5-hydroxy-3-oxo-2,3-dihydro-1H-indole-1-ethyl)malononitrile were mixed. The mixture was added to anhydrous ethanol (20 times the mass of the intermediate) in a molar ratio of 1:2, and dichloromethane (20 times the mass of intermediate 1) was added, and the mixture was stirred at 10°C and 200r / min for 30min. The anhydrous ethanol and dichloromethane were removed by rotary evaporation to obtain intermediate 2; 1,4-phenylenebis(phosphoryl dichloride), intermediate 2, and acetonitrile were mixed in a mass ratio of 1:3:40, ultrasonically dispersed for 20min, and triethylamine (0.2 times the mass of intermediate 2) was uniformly added dropwise at a rate of 15min at 20°C and 300r / min. After the addition was completed, the mixture was stirred for 3h, centrifuged, washed with anhydrous ethanol and deionized water 3 times each, and dried at 50°C under vacuum conditions for 14h to obtain functional microspheres; (2) 7-cyano-8-hydroxy-1,6-naphthyridine and pent-4-enoylhydrazide were added to 1,6-dioxane (10 times the mass of 7-cyano-8-hydroxy-1,6-naphthyridine) in a molar ratio of 1:1, and sodium methoxide (0.04 times the mass of 7-cyano-8-hydroxy-1,6-naphthyridine) was added, and the mixture was stirred at 80°C and 200 r / min for 4 hours, and dried at 50°C under vacuum for 8 hours to obtain pentenyltriazole monomer; pentenyltriazole monomer, hexenyl ethylene carbonate, azobisisobutyronitrile, m-dimethylbenzene were added to the mixture. Benzene was mixed evenly in a mass ratio of 1:1:0.03:24 to prepare a reaction solution; the reaction solution was divided into two parts, one of which accounted for 1 / 5 of the total mass of the reaction solution; cesium tungsten bronze powder and 1 / 5 of the reaction solution were mixed evenly in a mass ratio of 1:22, stirred at 70°C and 200r / min for 50min, and the remaining reaction solution was added dropwise at a uniform speed within 25min. After the addition was completed, the mixture was stirred and reacted for 4h, filtered, washed with anhydrous ethanol 3 times, and dried at 76°C under vacuum conditions for 11h to obtain modified cesium tungsten bronze powder; (3) Cardanol diglycidyl ether, anhydrous ethanol, and tetrabutylammonium bromide were mixed uniformly in a mass ratio of 1:4:0.04, placed in a high-pressure reactor, introduced with carbon dioxide gas to maintain the pressure at 2 MPa, stirred at 80°C and 300 r / min for 4 h, cooled to room temperature and discharged, and dried at 50°C for 8 h under vacuum conditions to obtain cyclocarbonated cardanol; 30 parts by mass of cyclocarbonated cardanol were weighed, 2 parts of modified cesium tungsten bronze powder, 4 parts of functional microspheres, 30 parts of cyclohexanone, 4 parts of isophorone diamine, and 4 parts of 1,3-bis(3-aminopropyl)-1,1,3,3-tetramethyldisiloxane; the cyclocarbonated cardanol, modified cesium tungsten bronze powder, functional microspheres, cyclohexanone, isophorone diamine, and 1,3-bis(3-aminopropyl)-1,1,3,3-tetramethyldisiloxane are uniformly mixed to prepare an infrared blocking polyurethane coating.

[0026] Example 2: A method for preparing an infrared-blocking polyurethane coating, comprising the following steps: (1) Potassium peroxymonosulfate and deionized water were mixed at a mass ratio of 1:3.5 to prepare an oxidant solution; N1,N1-di(4-aminophenyl)aniline and dichloromethane were mixed at a mass ratio of 1:7 to prepare an oxidant solution; at 0°C, 250 r / min stirring conditions, 11 times the mass of N1,N1-di(4-aminophenyl)aniline oxidant solution was added dropwise at a constant rate over 10 minutes, the temperature was raised to 25°C, stirring was continued for 10 minutes, 2.5 times the volume of dichloromethane oxidant solution was added and mixed evenly, the mixture was allowed to stand for stratification, and the organic phase was dried at 55°C under vacuum conditions for 3.5 hours to prepare intermediate 1; intermediate 1, 2-(5-hydroxy-3-oxo-2,3-dihydro-1H-indole-1-ethyl)propanediol were added to prepare an oxidant solution; The nitrile was added to anhydrous ethanol (21 times the mass of the intermediate) in a molar ratio of 1:2, and dichloromethane (21 times the mass of intermediate 1) was added, and the mixture was stirred at 20°C and 250r / min for 25 minutes. The anhydrous ethanol and dichloromethane were removed by rotary evaporation to obtain intermediate 2; 1,4-phenylenebis(phosphorus dichloride), intermediate 2, and acetonitrile were mixed in a mass ratio of 1:3.1:41, and ultrasonically dispersed for 25 minutes. At 25°C and 350r / min, triethylamine (0.25 times the mass of intermediate 2) was uniformly added dropwise within 15 minutes. After the addition was completed, the mixture was stirred and reacted for 2.5 hours. The mixture was centrifuged, washed with anhydrous ethanol and deionized water 4 times each, and dried at 55°C under vacuum conditions for 13 hours to obtain functional microspheres; (2) 7-cyano-8-hydroxy-1,6-naphthyridine and pent-4-enoylhydrazide were added to 1,6-dioxane (11 times the mass of 7-cyano-8-hydroxy-1,6-naphthyridine) in a molar ratio of 1:1, and sodium methoxide (0.05 times the mass of 7-cyano-8-hydroxy-1,6-naphthyridine) was added, and the mixture was stirred at 85°C and 250 r / min for 3.5 h, and dried at 55°C under vacuum for 7.5 h to obtain pentenyltriazole monomer; pentenyltriazole monomer, hexenyl ethylene carbonate, azobisisobutyronitrile, m-dimethylbenzene were added to the mixture. Benzene is mixed evenly in a mass ratio of 1:1.1:0.04:25 to prepare a reaction liquid; the reaction liquid is divided into two parts, one of which accounts for 1 / 5 of the total mass of the reaction liquid; cesium tungsten bronze powder and 1 / 5 of the reaction liquid are mixed evenly in a mass ratio of 1:23, stirred at 73°C and 250r / min for 45 minutes, and the remaining reaction liquid is added dropwise at a uniform speed within 25 minutes. After the addition is completed, the stirring reaction is continued for 3.5 hours, filtered, washed with anhydrous ethanol 4 times, and dried at 78°C under vacuum conditions for 10 hours to obtain modified cesium tungsten bronze powder; (3) Cardanol diglycidyl ether, anhydrous ethanol and tetrabutylammonium bromide were mixed uniformly in a mass ratio of 1:4.5:0.05, placed in a high-pressure reactor, introduced carbon dioxide gas to maintain the pressure at 2.1 MPa, stirred at 85 ° C and 400 r / min for 3.5 hours, cooled to room temperature and discharged, and dried at 55 ° C under vacuum conditions for 7 hours to obtain cyclic carbonated cardanol; 31 parts of cyclic carbonated cardanol were weighed by mass and modified 2.5 parts of modified cesium tungsten bronze powder, 4.5 parts of functional microspheres, 35 parts of cyclohexanone, 4.5 parts of isophorone diamine, and 4.5 parts of 1,3-bis(3-aminopropyl)-1,1,3,3-tetramethyldisiloxane; the cyclocarbonated cardanol, modified cesium tungsten bronze powder, functional microspheres, cyclohexanone, isophorone diamine, and 1,3-bis(3-aminopropyl)-1,1,3,3-tetramethyldisiloxane are uniformly mixed to prepare an infrared blocking polyurethane coating.

[0027] Example 3: A method for preparing an infrared-blocking polyurethane coating, comprising the following steps: (1) Potassium peroxymonosulfate and deionized water were mixed in a mass ratio of 1:4 to prepare an oxidant solution; N1,N1-di(4-aminophenyl)aniline and dichloromethane were mixed in a mass ratio of 1:8 to prepare an oxidant solution; at 0°C, 300 r / min stirring conditions, 12 times the mass of N1,N1-di(4-aminophenyl)aniline oxidant solution was added dropwise at a constant speed over 10 minutes, the temperature was raised to 30°C, stirring was continued for 9 minutes, 3 times the volume of dichloromethane of the oxidant solution was added and mixed evenly, the mixture was allowed to stand for stratification, and the organic phase was dried at 60°C under vacuum conditions for 3 hours to prepare intermediate 1; intermediate 1 and 2-(5-hydroxy-3-oxo-2,3-dihydro-1H-indole-1-ethyl)malononitrile were mixed in a mass ratio of 1:8 to prepare an oxidant solution; The intermediate 2 was added to anhydrous ethanol (22 times the mass of the intermediate) in a molar ratio of 1:2, and dichloromethane (22 times the mass of intermediate 1) was added, and the mixture was stirred at 30°C and 300r / min for 20min. The anhydrous ethanol and dichloromethane were removed by rotary evaporation to obtain intermediate 2; 1,4-phenylenebis(phosphoryl dichloride), intermediate 2, and acetonitrile were mixed in a mass ratio of 1:3.2:42, and ultrasonically dispersed for 30min. Under stirring conditions of 30°C and 400r / min, triethylamine (0.3 times the mass of intermediate 2) was uniformly added dropwise within 15min. After the addition was completed, the mixture was stirred for 2h, centrifuged, washed with anhydrous ethanol and deionized water 5 times each, and dried at 60°C under vacuum conditions for 12h to obtain functional microspheres; (2) 7-cyano-8-hydroxy-1,6-naphthyridine and pent-4-enoylhydrazide were added to 1,6-dioxane (12 times the mass of 7-cyano-8-hydroxy-1,6-naphthyridine) in a molar ratio of 1:1, and sodium methoxide (0.06 times the mass of 7-cyano-8-hydroxy-1,6-naphthyridine) was added, and the mixture was stirred at 90°C and 300 r / min for 3 hours, and dried at 60°C under vacuum for 7 hours to obtain pentenyltriazole monomer; pentenyltriazole monomer, hexenyl ethylene carbonate, azobisisobutyronitrile, m-dimethylbenzene were added to the mixture. Benzene and 1 / 2 of the reaction liquid were mixed in a mass ratio of 1:1.2:0.05:26 to prepare a reaction solution; the reaction solution was divided into two parts, one of which accounted for 1 / 5 of the total mass of the reaction solution; cesium tungsten bronze powder and 1 / 5 of the reaction solution were mixed in a mass ratio of 1:24, stirred at 76°C and 300 r / min for 40 minutes, and the remaining reaction solution was added dropwise at a uniform speed within 25 minutes. After the addition was completed, the mixture was stirred and reacted for 3 hours, filtered, washed with anhydrous ethanol 5 times, and dried at 80°C under vacuum conditions for 9 hours to obtain modified cesium tungsten bronze powder; (3) Cardanol diglycidyl ether, anhydrous ethanol, and tetrabutylammonium bromide were mixed uniformly in a mass ratio of 1:5:0.06, placed in a high-pressure reactor, and carbon dioxide gas was introduced to maintain the pressure at 2.2 MPa. The mixture was stirred at 90°C and 500 r / min for 3 hours. After cooling to room temperature, the mixture was discharged and dried at 60°C for 6 hours under vacuum conditions to obtain cyclic carbonated cardanol. 32 parts by mass of cyclic carbonated cardanol were weighed. , 3 parts of modified cesium tungsten bronze powder, 5 parts of functional microspheres, 40 parts of cyclohexanone, 5 parts of isophorone diamine, and 5 parts of 1,3-bis(3-aminopropyl)-1,1,3,3-tetramethyldisiloxane; the cyclocarbonated cardanol, modified cesium tungsten bronze powder, functional microspheres, cyclohexanone, isophorone diamine, and 1,3-bis(3-aminopropyl)-1,1,3,3-tetramethyldisiloxane are uniformly mixed to prepare an infrared blocking polyurethane coating.

[0028] Comparative Example 1: The difference between the preparation method of the infrared blocking polyurethane coating of Comparative Example 1 and Example 2 is that step (1) is not performed, and step (3) is modified as follows: cardanol diglycidyl ether, anhydrous ethanol, and tetrabutylammonium bromide are mixed uniformly in a mass ratio of 1:4.5:0.05, placed in a high-pressure reactor, and carbon dioxide gas is introduced to maintain the pressure at 2.1 MPa. The reaction is stirred at 85°C and 400 r / min for 3.5 hours, and the material is discharged after cooling to room temperature. It is dried at 55°C for 7 hours under vacuum conditions to obtain Cyclic carbonated cardanol; weigh, by mass, 31 parts of cyclic carbonated cardanol, 2.5 parts of modified cesium tungsten bronze powder, 35 parts of cyclohexanone, 4.5 parts of isophorone diamine, and 4.5 parts of 1,3-bis(3-aminopropyl)-1,1,3,3-tetramethyldisiloxane; uniformly mix the cyclic carbonated cardanol, modified cesium tungsten bronze powder, cyclohexanone, isophorone diamine, and 1,3-bis(3-aminopropyl)-1,1,3,3-tetramethyldisiloxane to produce an infrared-blocking polyurethane coating. The remaining steps are the same as in Example 2.

[0029] Comparative Example 2: The preparation method of the infrared blocking polyurethane coating of Comparative Example 2 differs from that of Example 2 in that step (2) is modified as follows: 1-pentene, hexenyl ethylene carbonate, azobisisobutyronitrile, and m-xylene are mixed uniformly in a mass ratio of 1:1.1:0.04:25 to prepare a reaction solution; the reaction solution is divided into two parts, one of which accounts for 1 / 5 of the total mass of the reaction solution; cesium tungsten bronze powder and 1 / 5 of the reaction solution are mixed uniformly in a mass ratio of 1:23, stirred at 73°C and 250 r / min for 45 minutes, and the remaining reaction solution is added dropwise at a uniform speed over 25 minutes. After the addition is completed, the reaction is continued to stir for 3.5 hours, filtered, washed with anhydrous ethanol four times, and dried at 78°C under vacuum conditions for 10 hours to obtain modified cesium tungsten bronze powder. The remaining steps are the same as those of Example 2.

[0030] Comparative Example 3: The preparation method of the infrared blocking polyurethane coating of Comparative Example 3 is different from that of Example 2 in that step (2) is not performed, and step (3) is modified as follows: cardanol diglycidyl ether, anhydrous ethanol, and tetrabutylammonium bromide are mixed uniformly in a mass ratio of 1:4.5:0.05, placed in a high-pressure reactor, and carbon dioxide gas is introduced to maintain the pressure at 2.1 MPa. The reaction is stirred at 85°C and 400 r / min for 3.5 hours, and the material is discharged after cooling to room temperature. It is dried at 55°C under vacuum conditions for 7 hours. Prepare cyclocarbonated cardanol; weigh, by mass, 31 parts cyclocarbonated cardanol, 4.5 parts functional microspheres, 35 parts cyclohexanone, 4.5 parts isophorone diamine, and 4.5 parts 1,3-bis(3-aminopropyl)-1,1,3,3-tetramethyldisiloxane; uniformly mix the cyclocarbonated cardanol, functional microspheres, cyclohexanone, isophorone diamine, and 1,3-bis(3-aminopropyl)-1,1,3,3-tetramethyldisiloxane to prepare an infrared-blocking polyurethane coating. The remaining steps are the same as in Example 2.

[0031] Comparative Example 4: The preparation method of the infrared blocking polyurethane coating of Comparative Example 4 is different from that of Example 2 only in step (3). Step (3) is modified as follows: cardanol diglycidyl ether, anhydrous ethanol and tetrabutylammonium bromide are mixed uniformly in a mass ratio of 1:4.5:0.05, placed in a high-pressure reactor, and carbon dioxide gas is introduced to maintain the pressure at 2.1 MPa. The reaction is stirred at 85°C and 400 r / min for 3.5 h, cooled to room temperature and then discharged. The mixture is then placed in a vacuum reactor. Under the following conditions, the mixture was dried at 55°C for 7 hours to obtain cyclocarbonated cardanol. 31 parts of cyclocarbonated cardanol, 2.5 parts of modified cesium tungsten bronze powder, 4.5 parts of functional microspheres, 35 parts of cyclohexanone, 4.5 parts of isophorone diamine, and 4.5 parts of 1,6-hexanediamine were weighed by mass. The cyclocarbonated cardanol, modified cesium tungsten bronze powder, functional microspheres, cyclohexanone, isophorone diamine, and 1,6-hexanediamine were uniformly mixed to obtain an infrared-blocking polyurethane coating. The remaining steps were the same as in Example 2.

[0032] Test Example 1 Infrared blocking performance test Test Method: Samples were prepared by coating the examples and comparative examples on ordinary glass plates, drying at 12°C for 2 hours, then cooling to 60°C and drying for 8 hours. The infrared transmittance (Tir) of the test samples in the range of 780-2500nm was measured using a spectrophotometer (UV3100). The infrared rejection was calculated as 1-Tir. The results are shown in Table 1.

[0033] Table 1

[0034] From the comparison of the experimental data of Examples 1 to 3 and Comparative Examples 1 to 4 in Table 1, it can be found that the infrared blocking polyurethane coating prepared in the present invention has good infrared blocking performance.

[0035] By comparison, the infrared blocking rates of Examples 1 to 3 are greater than that of Comparative Example 1, indicating that N1,N1-bis(4-aminophenyl)aniline is oxidized with potassium peroxymonosulfonate to prepare intermediate 1; intermediate 1 and 2-(5-hydroxy-3-oxo-2,3-dihydro-1H-indole-1-ethyl)malononitrile are reacted to form a conjugated molecule of an acceptor-donor-acceptor structure, namely intermediate 2; the P-Cl bond on 1,4-phenylenebis(phosphorus dichloride) is reacted with the hydroxyl group on intermediate 2 to prepare functional microspheres, and phosphorus element and an acceptor-donor-acceptor conjugated structure are introduced into the functional microspheres; the acceptor-donor-acceptor conjugated structure has an enhanced overlap of the highest occupied orbital and the lowest unoccupied orbital, can strongly absorb near-infrared light, and improve the infrared blocking performance of the infrared blocking polyurethane coating.

[0036] By comparison, the infrared blocking rates of Examples 1 to 3 are greater than that of Comparative Example 3, indicating that cesium tungsten bronze nanoparticles are very attractive near-infrared blocking materials due to their excellent optical properties. The near-infrared absorption performance brought about by surface plasmon resonance and electron transition (migration) of the nanoparticles provides strong absorption capacity in the near-infrared wavelength range and good transmittance in the visible light wavelength range. The addition of tungsten bronze nanoparticles can further enhance the infrared blocking performance of the infrared blocking polyurethane coating.

[0037] Test Example 2 Anti-aging performance test Test method: Pour the examples and comparative examples into a mold, dry at 12°C for 2 hours, cool to 60°C and dry for 8 hours, take out, and prepare standard specimens according to GB / T1040. Test their tensile strength W. Irradiate the standard specimens with a xenon arc lamp for 15 days with a radiation intensity of 0.51W / m 2 After the aging test, the standard specimens were removed and their tensile strength, Z, was measured. The performance degradation rate of the standard specimens was calculated as (WZ) / W × 100%. The results are shown in Table 2.

[0038] Table 2

[0039] From the comparison of the experimental data of Examples 1 to 3 and Comparative Examples 1 to 4 in Table 2, it can be found that the infrared blocking polyurethane coating prepared in the present invention has good anti-aging performance.

[0040] By comparison, the performance degradation rates of Examples 1 to 3 are less than that of Comparative Example 2, indicating that the pentenyltriazole monomer is prepared by reacting 7-cyano-8-hydroxy-1,6-naphthyridine and pent-4-enoylhydrazide; the pentenyltriazole monomer and hexenyl ethylene carbonate are polymerized and coated on the cesium tungsten bronze powder to prepare the modified cesium tungsten bronze powder; the triazole derivative structure is introduced into the modified cesium tungsten bronze powder, and the hydroxyl group and triazole on the triazole derivative structure can chelate to form a hydrogen bond six-membered ring. The hydrogen bond six-membered ring is unstable, and the hydrogen bond in the molecule will be broken under the action of ultraviolet light. The molecular structure is stabilized by releasing energy to the outside world, and the ultraviolet light energy is converted into heat energy for release, thereby improving the anti-aging performance of the infrared blocking polyurethane coating.

[0041] By comparison, the performance degradation rates of Examples 1 to 3 are lower than that of Comparative Example 3, indicating that the cesium tungsten bronze powder also has a good shielding effect on ultraviolet light, further improving the anti-aging performance of the infrared blocking polyurethane coating.

[0042] Test Example 3 Flame retardant performance test Test Method: The examples and comparative examples were poured into a mold, dried at 12°C for 2 hours, then cooled to 60°C and dried for 8 hours. Standard bars were prepared according to GB / T 2406-93 and the limiting oxygen index of the standard bars was tested. The results are shown in Table 3.

[0043] Table 3

[0044] From the comparison of the experimental data of Examples 1 to 3 and Comparative Examples 1 to 4 in Table 3, it can be found that the infrared blocking polyurethane coating prepared in the present invention has good flame retardant properties.

[0045] By comparison, the limiting oxygen index of Examples 1 to 3 is greater than that of Comparative Example 1, indicating that the functional microspheres are prepared by reacting the P-Cl bond on 1,4-phenylenebis(phosphorus dichloride) with the hydroxyl group on the intermediate 2, and phosphorus is introduced into the functional microspheres; the introduction of phosphorus can improve the flame retardant properties of the infrared blocking polyurethane coating.

[0046] By comparison, the limiting oxygen index of Examples 1 to 3 is greater than that of Comparative Example 4, indicating that the cyclic carbonated cardanol, modified cesium tungsten bronze powder, functional microspheres, cyclohexanone, isophoronediamine, and 1,3-bis(3-aminopropyl)-1,1,3,3-tetramethyldisiloxane are uniformly mixed to prepare an infrared-blocking polyurethane coating; the siloxane structure on 1,3-bis(3-aminopropyl)-1,1,3,3-tetramethyldisiloxane can promote carbonization during combustion to form a dense barrier layer, further improving the flame retardant properties of the infrared-blocking polyurethane coating.

[0047] The specific implementation methods described above further illustrate the objectives, technical solutions and beneficial effects of the present invention in detail. It should be understood that the above description is only a specific implementation method of the present invention and is not intended to limit the scope of protection of the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. An infrared blocking polyurethane coating, characterized in that: The infrared blocking polyurethane coating is prepared by polymerizing pentenyltriazole monomer and hexenyl ethylene carbonate to coat cesium tungsten bronze powder to obtain modified cesium tungsten bronze powder; reacting cardanol diglycidyl ether and carbon dioxide to obtain cyclic carbonated cardanol; and uniformly mixing cyclic carbonated cardanol, modified cesium tungsten bronze powder, functional microspheres, cyclohexanone, isophorone diamine, and 1,3-bis(3-aminopropyl)-1,1,3,3-tetramethyldisiloxane to obtain the infrared blocking polyurethane coating. The pentenyltriazole monomer is prepared by reacting 7-cyano-8-hydroxy-1,6-naphthyridine and pent-4-enoylhydrazide; The cyclic carbonated cardanol is prepared by reacting cardanol diglycidyl ether and carbon dioxide; The functional microspheres are prepared by reacting 1,4-phenylenebis(phosphorus oxychloride) and intermediate 2; The intermediate 2 is prepared by reacting the intermediate 1 with 2-(5-hydroxy-3-oxo-2,3-dihydro-1H-indole-1-ethyl)malononitrile; The intermediate 1 is prepared by oxidizing N1,N1-di(4-aminophenyl)aniline with potassium peroxymonosulfonate.

2. A method for preparing an infrared blocking polyurethane coating, characterized in that: The preparation method of the infrared blocking polyurethane coating comprises the following preparation steps: (1) 1,4-phenylenebis(phosphorus dichloride), intermediate 2, and acetonitrile were mixed uniformly in a mass ratio of 1:(3-3.2):(40-42), and ultrasonically dispersed for 20-30 min. Under stirring conditions of 20-30 ° C and 300-400 r / min, 0.2-0.3 times the mass of intermediate 2 triethylamine was added dropwise at a uniform rate within 15 min. After the addition was completed, the reaction was continued with stirring for 2-3 h, centrifuged, washed with anhydrous ethanol and deionized water 3-5 times each, and dried at 50-60 ° C under vacuum conditions for 12-14 h to obtain functional microspheres; (2) Pentenyltriazole monomer, hexenyl ethylene carbonate, azobisisobutyronitrile, and m-xylene are mixed evenly in a mass ratio of 1:(1~1.2):(0.03~0.05):(24~26) to prepare a reaction solution; the reaction solution is divided into two parts, one of which accounts for 1 / 5 of the total mass of the reaction solution; cesium tungsten bronze powder and 1 / 5 of the reaction solution are mixed evenly in a mass ratio of 1:(22~24), stirred at 70~76℃ and 200~300r / min for 40~50min, and the remaining reaction solution is added dropwise at a uniform speed within 25min. After the addition is completed, the reaction is continued to stir for 3~4h, filtered, washed with anhydrous ethanol 3~5 times, and dried at 76~80℃ under vacuum conditions for 9~11h to obtain modified cesium tungsten bronze powder; (3) Cyclocarbonated cardanol, modified cesium tungsten bronze powder, functional microspheres, cyclohexanone, isophorone diamine, and 1,3-bis(3-aminopropyl)-1,1,3,3-tetramethyldisiloxane are mixed evenly to prepare an infrared blocking polyurethane coating.

3. The method for preparing an infrared blocking polyurethane coating according to claim 2, characterized in that: The preparation method of the intermediate 2 in step (1) is as follows: intermediate 1 and 2-(5-hydroxy-3-oxo-2,3-dihydro-1H-indole-1-ethyl)malononitrile are added in a molar ratio of 1:2 to anhydrous ethanol 20 to 22 times the mass of the intermediate, and dichloromethane 20 to 22 times the mass of the intermediate 1 is added, and the mixture is stirred at 10 to 30° C. and 200 to 300 r / min for 20 to 30 minutes, and anhydrous ethanol and dichloromethane are removed by rotary evaporation to obtain intermediate 2.

4. The method for preparing an infrared blocking polyurethane coating according to claim 3, characterized in that: The preparation method of the intermediate 1 is as follows: N1,N1-bis(4-aminophenyl)aniline and dichloromethane are uniformly mixed in a mass ratio of 1:(6-8), and an oxidant solution with a mass of 10 to 12 times that of the N1,N1-bis(4-aminophenyl)aniline is added dropwise at a constant rate over 10 minutes at 0°C and 200 to 300 r / min of stirring. The temperature is raised to 20 to 30°C, and the stirring reaction is continued for 9 to 11 minutes. Dichloromethane with a volume of 2 to 3 times that of the oxidant solution is added and mixed uniformly. The mixture is allowed to stand for separation, and the organic phase is dried at 50 to 60°C under vacuum conditions for 3 to 4 hours to obtain the intermediate 1.

5. The method for preparing an infrared blocking polyurethane coating according to claim 4, characterized in that: The preparation method of the oxidant solution is as follows: potassium peroxymonosulfonate and deionized water are uniformly mixed in a mass ratio of 1:(3-4) to prepare the oxidant solution.

6. The method for preparing an infrared blocking polyurethane coating according to claim 2, characterized in that: The particle size of the cesium tungsten bronze powder in step (2) is 80 nm.

7. The method for preparing an infrared blocking polyurethane coating according to claim 2, characterized in that: The preparation method of the pentenyltriazole monomer in step (2) is as follows: 7-cyano-8-hydroxy-1,6-naphthyridine and pent-4-enoylhydrazide are added in a molar ratio of 1:1 to 1,6-dioxane with a mass of 10 to 12 times that of 7-cyano-8-hydroxy-1,6-naphthyridine, and sodium methoxide with a mass of 0.04 to 0.06 times that of 7-cyano-8-hydroxy-1,6-naphthyridine is added, and the mixture is stirred at 80 to 90°C and 200 to 300 r / min for 3 to 4 hours, and dried at 50 to 60°C under vacuum conditions for 7 to 8 hours to obtain the pentenyltriazole monomer.

8. The method for preparing an infrared blocking polyurethane coating according to claim 2, characterized in that: The preparation method of the cyclic carbonated cardanol in step (3) is as follows: cardanol diglycidyl ether, anhydrous ethanol, and tetrabutylammonium bromide are uniformly mixed in a mass ratio of 1:(4~5):(0.04~0.06), placed in a high-pressure reactor, and carbon dioxide gas is introduced to maintain the pressure at 2~2.2MPa. The reaction is stirred at 80~90°C and 300~500r / min for 3~4h. After cooling to room temperature, the material is discharged and dried at 50~60°C under vacuum conditions for 6~8h to obtain cyclic carbonated cardanol.

9. The method for preparing an infrared blocking polyurethane coating according to claim 2, characterized in that: The amounts of the cyclocarbonated cardanol, modified cesium tungsten bronze powder, functional microspheres, cyclohexanone, isophorone diamine, and 1,3-bis(3-aminopropyl)-1,1,3,3-tetramethyldisiloxane used in step (3) are as follows: 30-32 parts by mass of cyclocarbonated cardanol, 2-3 parts of modified cesium tungsten bronze powder, 4-5 parts of functional microspheres, 30-40 parts of cyclohexanone, 4-5 parts of isophorone diamine, and 4-5 parts of 1,3-bis(3-aminopropyl)-1,1,3,3-tetramethyldisiloxane.

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