CN-121975415-A - Self-cleaning composite coating and preparation method thereof

Abstract

The invention discloses a super-long-acting intelligent self-cleaning coating based on bionic multilevel structure and rare earth-graphene synergistic enhancement and a preparation method thereof. The coating is designed by an organic-inorganic-hybrid three-module, adopts multifunctional nano materials such as three-rare earth co-doped TiO2, graphene oxide-CeO 2-ZrO2, nano boron nitride and the like, combines a pre-hydrolyzed three-functional silane and fluorosilicone-polyurethane double-resin system, and forms a composite coating with micro-nano roughness, full spectrum catalysis, ultraviolet shielding, high thermal conductivity and strong adhesion characteristics through plasma-solvothermal activation, high-energy three-step composite, electrostatic spraying and ultraviolet-thermal-moisture gradient curing processes. The water contact angle of the coating is less than or equal to 3 degrees, the visible light transmittance is more than or equal to 94 percent, the performance retention rate of QUVB accelerated aging for 3000 hours is more than 90 percent, and the coating has excellent self-cleaning property, wear resistance, salt spray resistance and outdoor long-acting stability, and is suitable for surface functionalization and protection of various base materials.

Inventors

• ZHANG JIAN
• YANG FENGJIAO
• ZHANG JIANWEN
• Yu Hujun
• CHE YANG
• YAO ZHIQIANG
• YU QIANXI

Assignees

• 成都小涂帝科技有限公司

Dates

Publication Date

20260505

Application Date

20260227

Claims (2)

1. 1. The self-cleaning composite coating is characterized by comprising 55-60wt% of film-forming resin, 18-22wt% of inorganic functional nano modules and the balance of interface and process auxiliary agents; The film-forming resin comprises aqueous aliphatic polyurethane dispersoid and aqueous fluorosilicone modified acrylic ester emulsion, wherein the proportion of the aqueous aliphatic polyurethane dispersoid and the aqueous fluorosilicone modified acrylic ester emulsion in the composite coating is 50-55wt% and 5-7wt%; The inorganic functional nano module comprises 55.6-60 wt% of amino modified hydrophilic nano SiO 2 , 22.2-27.3% of Nd-Eu-La three-rare earth co-doped nano TiO 2 , 11.1-13.6% of graphene oxide-CeO 2 -ZrO 2 ternary hybrid material and 5.6-9.1% of nano boron nitride; The interface and process auxiliary agent comprises 2.5-3.5wt% of pre-hydrolyzed mercapto-epoxy-vinyl trifunctional silane, 7-9wt% of propylene glycol phenyl ether, 0.4-0.8wt% of polyether-siloxane copolymer flatting agent, 1.2-1.8wt% of aqueous ultraviolet-oxygen dual-curing initiator, 3-5wt% of ethanol and the balance of deionized water.
2. 2. A method for preparing a self-cleaning composite coating according to claim 1, comprising the steps of: step 1, nanomaterial plasma-solvothermal synergistic activation, comprising the following sub-steps: Step 1-1, mixing amino modified hydrophilic nano SiO 2 , nd-Eu-La three-rare earth co-doped nano TiO 2 , graphene oxide-CeO 2 -ZrO 2 ternary hybrid material and nano boron nitride according to a proportion, placing the mixture in a plasma fluidized bed, and treating the mixture for 15 minutes at power of 300W under an Ar/O 2 mixed atmosphere to obtain a nano material mixture; Step 1-2, adding the nano material mixture, pre-hydrolyzed mercapto-epoxy-vinyl trifunctional silane and ethanol into a solvothermal reaction kettle together, and reacting for 6 hours at 120 ℃ under autogenous pressure to realize surface organic modification; Step 1-3, centrifugally washing and vacuum drying the product obtained in the step 1-2 to obtain composite nano powder; step2, resin matrix vacuum defoamation-pre-emulsification, comprising the following sub-steps: Step 2-1, mixing aqueous aliphatic polyurethane dispersoid with aqueous fluorosilicone modified acrylic ester emulsion according to a proportion, and sequentially adding propylene glycol phenyl ether, polyether-siloxane copolymer flatting agent, aqueous ultraviolet-oxygen dual-curing initiator and deionized water into the mixed solution; step 2-2, mixing the mixture obtained in the step 2-1 in a vacuum planetary mixer to form uniform and bubble-free resin pre-emulsion; Step 3, high-energy shearing-ultrasonic-microwave three-step compounding, which comprises the following substeps: Step 3-1, slowly adding the composite nano powder into the resin pre-emulsion, and treating for 1 hour by a high-speed shearing emulsifying machine; Step 3-2, transferring to an ultrasonic wave-microwave synergistic reaction instrument, and circularly treating for 3 periods under the alternating action of 40kHz ultrasonic wave and 800W microwave for 10 minutes per period to obtain coating slurry; Step 4, curing the coating slurry through electrostatic spraying-ultraviolet-heat-moisture gradient, and interpenetrating-crosslinked network structure, wherein the method comprises the following substeps: step 4-1, preprocessing a substrate, namely cleaning the substrate by adopting an acetone solution, cleaning the substrate by using plasma, and performing atomization treatment of a silane coupling agent; Step 4-2, uniformly spraying the coating slurry obtained in the step 3 on the surface of the pretreated substrate by adopting a six-axis robot electrostatic spraying system to form a layer of wet film; step 4-3, immediately feeding the sprayed wet film into an ultraviolet-infrared combined curing tunnel furnace for curing treatment, wherein the ultraviolet-infrared combined curing tunnel furnace comprises the following three treatment areas: a first area, 365nm LED ultraviolet, 1000mW/cm2 intensity, for 30 seconds; a second zone, in which medium-wave infrared is preheated for 1 minute at 80 ℃ and the wavelength is 2-4 mu m; a third zone, namely hot air circulation, wherein the temperature is 60 ℃ and maintained for 2 hours; and 4-4, curing the cured coating in a constant temperature and humidity room for 7 days.

Description

Self-cleaning composite coating and preparation method thereof Technical Field The invention belongs to the technical fields of functional coating materials, nano composite materials and surface engineering intersection, and in particular relates to a composite coating with super-hydrophilicity, photocatalysis self-cleaning, high light transmittance, strong adhesion and extreme weather resistance and a preparation process thereof, which are suitable for surface functionalization and long-term protection of various base materials such as photovoltaic glass, building curtain walls, automobile glass, optical lenses, marine facilities and the like. Background With the global growing demand for energy-saving and environment-friendly, low-maintenance buildings and high-performance optical devices, self-cleaning coating technology has become a research hotspot in the field of surface engineering. The traditional self-cleaning coating is mainly divided into two types, namely a super-hydrophobic coating based on a lotus leaf effect, which can realize that water drops roll off to take away pollutants through a low-surface-energy substance and a micro-nano coarse structure, but has the problems of easy adhesion of greasy dirt, poor durability, low light transmittance and the like, and a super-hydrophilic coating based on water film spreading, which can wash out the surface through forming a continuous water film, but has easy attenuation of hydrophilicity, poor weather resistance, insufficient mechanical strength and limited self-cleaning capability in a weak light or no light environment. Currently, a plurality of super-hydrophilic self-cleaning coatings such as 'iridescent ceramic super-hydrophilic coatings' are available on the market, the water contact angle is stated to be less than or equal to 9 degrees, and the super-hydrophilic self-cleaning coatings have certain self-cleaning capability, but the following common defects still exist: 1. The weather resistance is generally insufficient, and the performance is obviously reduced after QUVB is aged for 500-1000 hours; 2. the photocatalytic activity depends on ultraviolet light, and the visible light response is weak; 3. most of them are double-component or need high-temperature curing, the construction is inconvenient; 4. poor adhesion to complex substrates (e.g., polymers, ceramics, composites); 5. The hydrophilicity and the light transmittance decay are obvious after long-term outdoor use. In addition, the silane coupling agent in the prior art is easy to hydrolyze and self-polymerize in a single-component aqueous system, so that the storage life of the coating is short, and the interface binding force is insufficient after construction. Therefore, a single-component coating system which has super-hydrophilicity, full-spectrum photocatalysis, super-strong adhesive force, high light transmittance and long-acting and stable service under severe outdoor environment is developed, and the single-component coating system has important scientific and engineering values. Disclosure of Invention The invention aims to overcome the defects of the prior art and provide a self-cleaning composite coating and a preparation method thereof, wherein the coating is designed by an organic-inorganic-hybridization three-module, adopts three-rare earth co-doped TiO 2, graphene oxide-CeO 2-ZrO2, nano boron nitride and other multifunctional nano materials, and combines a pre-hydrolyzed trifunctional silane and fluorosilicone-polyurethane double-resin system to form the composite coating with micro-nano roughness, full spectrum catalysis, ultraviolet shielding, high thermal conductivity and strong adhesion. The water contact angle of the coating is less than or equal to 3 degrees, the visible light transmittance is more than or equal to 94 percent, the performance retention rate of QUVB accelerated aging for 3000 hours is more than 90 percent, and the coating has excellent self-cleaning property, wear resistance, salt spray resistance and outdoor long-acting stability, and is suitable for surface functionalization and protection of various base materials. The invention aims to provide a self-cleaning composite coating, which comprises 55-60wt% of film-forming resin, 18-22wt% of inorganic functional nano modules and the balance of an interface and a process auxiliary agent; The film-forming resin comprises aqueous aliphatic polyurethane dispersoid and aqueous fluorosilicone modified acrylic ester emulsion, wherein the proportion of the aqueous aliphatic polyurethane dispersoid and the aqueous fluorosilicone modified acrylic ester emulsion in the composite coating is 50-55wt% and 5-7wt%; The inorganic functional nano module comprises 55.6-60 wt% of amino modified hydrophilic nano SiO 2, 22.2-27.3% of Nd-Eu-La three-rare earth co-doped nano TiO 2, 11.1-13.6% of graphene oxide-CeO 2-ZrO2 ternary hybrid material and 5.6-9.1% of nano boron nitride; The interface and process auxiliary agent com