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CN-122011811-A - Hydrophilic coating and preparation method and application thereof

CN122011811ACN 122011811 ACN122011811 ACN 122011811ACN-122011811-A

Abstract

The invention discloses a hydrophilic coating and a preparation method and application thereof, belonging to the technical field of functional coating materials, wherein the hydrophilic coating comprises the following preparation raw materials in percentage by mass: 15-25% of silica sol, 3-9% of carboxylated h-BN@SiO 2 core-shell powder, 0.5-3% of long-chain silane coupling agent, 10-35% of water-based organic silicon resin and 5-15% of polyvinyl alcohol resin. S1, preparing carboxylated h-BN@SiO 2 core-shell powder, S2, uniformly mixing the preparation raw materials required by the hydrophilic coating to obtain the hydrophilic coating. According to the invention, the carboxylated h-BN@SiO 2 core-shell functional filler is constructed, so that the durable super-hydrophilicity, long-acting corrosion resistance, high heat conduction and excellent flexibility of the coating are realized, and the requirements of the severe working condition of the aluminum foil of the air conditioner heat exchanger are especially adapted.

Inventors

  • ZHANG LIANGHAO
  • XU FANG
  • WU WEI
  • WU CHUNREN

Assignees

  • 广东瑞和新材料有限公司

Dates

Publication Date
20260512
Application Date
20260130

Claims (10)

  1. 1. The hydrophilic coating is characterized by comprising, by mass, 15-25% of silica sol, 3-9% of carboxylated h-BN@SiO 2 core-shell powder, 0.5-3% of long-chain silane coupling agent, 10-35% of aqueous organic silicon resin and 5-15% of polyvinyl alcohol resin.
  2. 2. The hydrophilic coating of claim 1, wherein the carboxylated h-bn@sio 2 core-shell powder has a carboxylated h-BN core and a SiO 2 shell; and/or the silicon dioxide content in the silica sol is 20-40wt%, and the pH of the silica sol is 8-10; and/or the long-chain silane coupling agent is at least one of octyl triethoxysilane, vinyl trimethoxysilane, dodecyl trimethoxysilane and hexadecyl trimethoxysilane; And/or the aqueous silicone resin is at least one of SILRES ® BS 45,SILRES ® IC 836 and SILRES ® BS 1042.
  3. 3. The hydrophilic coating according to claim 1, wherein the hydrophilic coating is prepared from a raw material further comprising 1-5% of a processing aid, preferably 1-3% of a processing aid; And/or, the processing aid comprises a leveling agent, a defoaming agent and a dispersing agent; And/or the dispersant is BYK-190, TEGO Dispers 755W, or TEGO Dispers 750W; And/or the leveling agent is BYK-346, TEGO Glide 410 or EFKA-3888; And/or, the defoamer is BYK-022 or TEGO Foamex 810.
  4. 4. The hydrophilic coating according to claim 3, wherein the hydrophilic coating is prepared from 15-25% of silica sol, 3-9% of carboxylated h-BN@SiO 2 core-shell powder, 0.5-3% of long-chain silane coupling agent, 10-35% of aqueous organic silicon resin, 5-15% of polyvinyl alcohol resin, 1-5% of processing aid and the balance of water.
  5. 5. A hydrophilic coating according to claim 1, wherein the hydrophilic coating forms a hydrophilic coating having a hydrophilic angle of 10 ° or less, preferably 3-8 °; And/or the heat conductivity coefficient of the hydrophilic coating is more than or equal to 0.90W/(m.K).
  6. 6. The method for preparing a hydrophilic coating according to any one of claims 1 to 5, comprising the steps of: s1, preparing carboxylated h-BN@SiO 2 core-shell powder: s1.1, carrying out carboxylation treatment on the h-BN nano sheet in mixed acid to obtain carboxylated h-BN; S1.2, coupling the dispersion liquid of carboxylated h-BN with aminosilane to obtain an h-BN intermediate; S1.3, reacting a silicon source with the h-BN intermediate to form an outer SiO 2 layer; S2, uniformly mixing the preparation raw materials required by the hydrophilic coating to obtain the hydrophilic coating.
  7. 7. The method of claim 6, wherein S1 satisfies at least one of the following conditions ①~⑤: ① The adding ratio of the h-BN nanosheets to the aminosilane to the silicon source is 1 g:1-5 mL:3-8 mL; ② The particle size of the h-BN nano sheet is 50-200 nm; ③ The mixed acid is a mixture of concentrated sulfuric acid and concentrated nitric acid, and the volume ratio of the concentrated sulfuric acid to the concentrated nitric acid is 2-4/1; ④ The aminosilane is at least one of 3-aminopropyl triethoxysilane, 3-aminopropyl trimethoxysilane, 4-aminobutyl triethoxysilane and 4-aminobutyl trimethoxysilane; ⑤ The silicon source is at least one of ethyl orthosilicate, methyl orthosilicate, propyl orthosilicate and butyl orthosilicate.
  8. 8. The method of claim 7, wherein S1 satisfies at least one of the following conditions ①~④: ① In S1.1, the volume mass ratio of the mixed acid/the h-BN nano sheet is 150-250 mL/g; ② In S1.1, the carboxylation treatment is reflux for 6-12 hours at 80-120 ℃; ③ In S1.2, the coupling is performed for 4-8 hours under 50-80 ℃ reflux; ④ In S1.3, the reaction process is to dropwise add a silicon source into the dispersion liquid of the h-BN intermediate at the temperature of 30-50 ℃ and react for 10-18 h.
  9. 9. The method for preparing the hydrophilic coating according to claim 6, wherein the step S2 is characterized in that the h-BN@SiO 2 core-shell powder and the dispersing agent are mixed in water to form primary slurry after high-speed shearing and dispersing, silica sol, water-based organic silicon resin and long-chain silane coupling agent are sequentially added into the primary slurry to be uniformly mixed, and finally the leveling agent and the defoaming agent are added to be uniformly mixed to obtain the hydrophilic inorganic coating.
  10. 10. Use of a hydrophilic coating according to any one of claims 1 to 5 or a hydrophilic inorganic coating prepared by a preparation method according to any one of claims 6 to 9 in the field of heat dissipating devices.

Description

Hydrophilic coating and preparation method and application thereof Technical Field The invention belongs to the technical field of functional coating materials, and particularly relates to a hydrophilic coating, a preparation method and application thereof. Background The aluminum foil of the air conditioner heat exchanger can generate condensed water due to dew condensation on the surface under the refrigeration working condition. If the surface of the aluminum foil is hydrophobic, the condensed water will form discrete water drops to be retained among the fins, so that not only is the wind resistance increased, the heat exchange efficiency reduced and the energy consumption of the air blower increased, but also conditions are provided for breeding microorganisms such as mould and the like, and the air quality is affected. Therefore, a high-performance hydrophilic coating must be coated on the surface of the aluminum foil to allow condensed water to rapidly spread into a thin water film and smoothly drain away. A qualified air-conditioning aluminum foil hydrophilic coating must have durable and rapid hydrophilicity, excellent corrosion resistance to protect aluminum substrates, good adhesion and flexibility to withstand processing stresses, and excellent weatherability to cope with long-term hot and humid and cold cycling environments. Currently, hydrophilic coatings on the market are mainly classified into organic and inorganic types. Although the initial performance of the organic coating (mainly using an acrylic acid system or a modified system thereof) is still available, the polymer chain of the organic coating is easy to age and degrade in a damp and hot environment, so that the hydrophilicity is rapidly attenuated. More importantly, the low-molecular organic substances generated after degradation are remained on the surface of the aluminum foil, and released along with air flow in the running process of the air conditioner, so that the air outlet peculiar smell is caused, and the indoor air quality and the use experience are directly affected. In contrast, the inorganic coating (such as a pure silica sol system) has stable components, can not generate peculiar smell substances due to decomposition, and radically eliminates the problem of peculiar smell. However, the traditional inorganic coating is generally poor in heat conduction performance, and a heat insulation layer is more easily formed on the surface of the aluminum foil during thick coating, so that heat transfer is hindered, and the overall energy efficiency of the heat exchanger is affected. In addition, the paint has the problems of large brittleness, easy cracking, insufficient adhesion with an aluminum foil substrate and the like, and the hydrophilic function of the paint can be realized by a thicker coating, so that the comprehensive performance of the paint in practical application is further limited. As in the prior art, the Chinese patent CN108864376A, CN117380509A, CN102952442A, CN102719188A and the like are all hydrophilic coatings prepared by adopting an acrylic acid system or a modified system thereof as a main film forming substance, but the coatings of the systems have good hydrophilic performance, are easy to adsorb moisture or other harmful substances in the air, are applied to fins with smaller intervals, are easy to degrade for a long time to generate low molecular organic substances, and further generate peculiar smell. At present, inorganic hydrophilic paint such as CN112961520A is adopted to disclose a waterproof long-acting inorganic zinc oxide super-hydrophilic paint, and a preparation method and application thereof, the technology adopts silicate and zinc oxide as raw materials to prepare the water-based inorganic super-hydrophilic paint, the coating formed by the coating is a flat rigid coating, has good appearance, excellent antifouling self-cleaning performance and antimicrobial adhesion performance, and has the characteristics of long-term underwater stability and high mechanical strength, but has poor flexibility, and cannot be used on an air-conditioning aluminum foil substrate. And as shown in CN119819559A, the technology uses silicate, boron compound and hydroxylated nano silicon dioxide as core components, and is matched with reactive raw materials such as surfactant and carboxyl acrylic acid monomer, etc., and the reaction is carried out for 6-12 hours at 60-80 ℃ to form a stable system, the coating has excellent hydrophilic performance, the initial hydrophilic angle is lower than 4 DEG, the low hydrophilic angle and the anti-fouling capability are still maintained in a long-term high-temperature high-oil environment, meanwhile, the adhesive force and the water storage function of the coating are enhanced through a porous base layer structure, but the thickness of the coating is thicker, and the pure silicate resin is coated on the surface of the air conditioner aluminum foil to form a heat insulation laye