High-permeability waterproof coating and application of high-permeability waterproof coating in paint surface protective film

Abstract

The invention relates to a high-permeability waterproof coating and application thereof in a paint surface protective film, and relates to the field of coatings and protective films. The waterproof coating comprises the following components in parts by mass: 35-65 parts of methyl polysiloxane resin, 3-5 parts of fluorocarbon modified polysiloxane, 8-12 parts of acrylic resin, 15-20 parts of high-permeability waterproof filler, 1-3 parts of a dispersant, 1-3 parts of a coalescing agent, 0.5-1 part of a stabilizer, 1-2 parts of a defoaming agent, 1-3 parts of a flatting agent and 10-20 parts of a solvent, the high-permeability waterproof filler comprises nano silicon dioxide. The paint surface protective film applying the high-permeability waterproof filler comprises a protective film, a high-permeability waterproof coating, a base film layer, an adhesive layer and a release film which are sequentially arranged, wherein the high-permeability waterproof coating is obtained by coating a high-permeability waterproof coating. The coating has the effects of improving the waterproof performance, the light transmittance performance and the weather resistance of the coating, and can provide long-acting protection for a paint surface when being applied to a paint surface protection film.

Description

Technical Field

[0001] The present application relates to the field of coatings and protective films, and in particular to a highly permeable waterproof coating and its application in paint surface protective films. Background Art

[0002] In modern industry, paint protection for all types of equipment and vehicles is crucial. Whether it's cars, high-speed trains, aircraft, or wind turbines, the paint finish not only impacts aesthetics but also directly impacts the equipment's lifespan and performance. With the continuous advancement of technology, the demand for paint protection is also increasing, prompting the exploration of new protection technologies and materials. Proper paint protection prevents the paint from being eroded by external environmental factors such as UV radiation, rain, and dust, thereby maintaining the equipment's beautiful appearance and integrity. Effective protection measures also reduce the frequency of repairs and paint replacements, lowering operating costs and improving equipment reliability and safety.

[0003] In the past, in order to protect the paint surface, common practices included using ordinary protective paint and attaching plastic film. Ordinary protective paint achieves its protective effect by applying a layer of paint with certain protective properties on the paint surface. This type of paint can usually block ultraviolet rays and some minor friction to a certain extent, but the protective effect is limited. Attaching plastic film is to stick a pre-made plastic film on the paint surface. This method is relatively simple, but the plastic film has poor adhesion and durability, and is prone to problems such as bubbles and warping. It may also lose its protective effect due to aging after long-term use. In addition, there are some methods that use chemical plating to form a protective film on the paint surface through chemical reactions, but this method is complex, costly, and has certain environmental pollution.

[0004] However, these existing paint protection methods have many shortcomings. Ordinary protective paints have poor waterproof and breathable properties, which makes it difficult to meet the requirements of some application scenarios with high waterproof and breathable requirements. The method of attaching plastic film is not only not firmly attached, but also has weak protective ability and cannot effectively resist long-term exposure to ultraviolet rays and erosion by rainwater. Although the chemical plating method has a relatively good protective effect, its complex process and high cost limit its widespread application. Therefore, it is necessary to develop a highly permeable waterproof coating for use in paint protection films. Summary of the Invention

[0005] In order to improve the paint surface protection effect, the present application provides a highly permeable waterproof coating and its application in a paint surface protection film.

[0006] The present application provides a highly permeable waterproof coating and its application in a paint protection film using the following technical solutions: In the first aspect, the present application provides a highly permeable waterproof coating, which adopts the following technical solution: A highly permeable waterproof coating comprising the following components in parts by mass: 35-65 parts of methyl polysiloxane resin 3-5 parts of fluorocarbon modified polysiloxane 8-12 parts of acrylic resin 15-20 parts of high permeability waterproof filler 1-3 parts dispersant 1-3 parts of film-forming aid 0.5-1 part stabilizer 1-2 parts defoaming agent 1-3 parts of leveling agent 10-20 parts of solvent; The fluorocarbon-modified polysiloxane is prepared by the following steps: A mixture of perfluorooctylethyltrimethoxysilane and propyltrimethoxysilane was added to a trimethoxy-terminated polydimethylsiloxane solution, the pH was adjusted to acidic, water was added after pre-hydrolysis, and the mixture was heated and stirred for reaction. After the reaction was completed, the pH was adjusted to neutral, and the mixture was rotary evaporated and purified to obtain a fluorocarbon-modified polysiloxane. The highly permeable and waterproof filler comprises nano silicon dioxide.

[0007] Methyl polysiloxane resin is used as the main film-forming matrix. Its siloxane segments form a three-dimensional cross-linked network through hydrolysis and condensation, giving the coating flexibility and weather resistance. Fluorocarbon modified polysiloxane introduces perfluoroalkyl segments, which form a low surface energy hydrophobic layer on the siloxane skeleton through chemical bonding, and synergistically inhibits water molecule penetration with methyl polysiloxane. Acrylic resin enhances interfacial adhesion through esterification reaction between carboxyl groups and silanol groups, and interpenetrates with the siloxane network to form a rigid and flexible mechanical support. Nano-silica filler hydrogen bonds with the resin through surface hydroxyl groups. By filling micropores, the synergistic effect of its micro-nano rough structure and fluorocarbon chains further enhances the hydrophobic performance; dispersants ensure uniform distribution of nanoparticles, film-forming aids optimize the solvent volatilization gradient, stabilizers inhibit phase separation, and defoamers and leveling agents synergistically eliminate interface defects; the various components cooperate and synergize with each other, the chemical bonding of fluorocarbon chains and siloxanes constructs a hydrophobic barrier, acrylic resins are interspersed and cross-linked to enhance network density, and the physical interlocking of nanofillers and resins forms a multi-level anti-penetration structure, ultimately achieving a simultaneous improvement in light transmittance and waterproof performance.

[0008] Using trimethoxy-terminated polydimethylsiloxane as the skeleton, the siloxane active sites are activated through a pre-hydrolysis reaction under acidic conditions, and then perfluorooctylethyltrimethoxysilane and propyltrimethoxysilane are introduced. The former constructs a hydrophobic barrier through the extremely low surface energy characteristics of the perfluoroalkyl chain segment, while the latter provides reactive active sites through the acrylic acid group to form a chemical bond with the siloxane network. In the gradient molecular structure formed, the fluorocarbon segments are enriched on the surface to form a hydrophobic layer, while the siloxane network provides mechanical support and the acrylic acid group serves as a functional bridge to achieve improved waterproof performance and weather resistance.

[0009] Preferably, the mass ratio of the trimethoxy-terminated polydimethylsiloxane, perfluorooctylethyltrimethoxysilane and propyltrimethoxysilane is 1:(0.19-0.25):0.08.

[0010] The fluorocarbon-modified polysiloxane prepared according to the above mass ratio has good reactivity and can effectively improve the waterproof and weather resistance of the coating.

[0011] Preferably, the nano-silica is replaced by hollow mesoporous silica.

[0012] Hollow mesoporous silica has a dual-scale structure of hollow core-mesoporous shell. Its mesoporous shell forms a hydrogen bond network with the resin matrix through surface hydroxyl groups to fill the microscopic pores, blocking the penetration path of water molecules; the refractive index of hollow mesoporous silica is between that of air and the resin matrix, and the light wave interference effect is used to reduce the interface reflection loss and improve the transmittance of the coating; the ultraviolet multiple scattering of the mesoporous structure is combined with the thermal expansion buffering effect of the hollow core to inhibit the expansion of microcracks caused by internal stress in the coating and improve the weather resistance of the coating.

[0013] Preferably, the hollow mesoporous silica is modified and prepared by the following steps: The hollow mesoporous silica and γ-methacryloxypropyltrimethoxysilane are mixed in a solvent, the pH is adjusted to acidic, pre-hydrolyzed, heated and stirred for reaction, and after the reaction is completed, cooled, washed and dried to obtain hydrophobically modified hollow mesoporous silica.

[0014] The mesoporous shell of hollow mesoporous silica forms a chemical bond with the resin matrix through a pre-hydrolyzed silane coupling agent, constructing long-chain hydrophobic groups on the surface, reducing surface energy and forming a dense hydrophobic barrier, blocking the penetration path of water molecules; the refractive index of the hollow core matches that of the resin matrix, reducing interface reflection losses through the light wave interference effect, and combining the precise control of the light scattering path by the mesoporous shell to improve the transmittance; the chemical grafting of the silane coupling agent enhances the interfacial bonding force and inhibits stress cracking of the hollow structure caused by thermal expansion, while the multiple scattering of ultraviolet rays by the mesoporous shell and the thermal buffering effect of the hollow core synergistically delay coating aging and improve the weather resistance of the coating.

[0015] Preferably, the highly permeable and waterproof filler further comprises rare earth-doped zinc oxide, which is prepared by the following steps: Zinc acetate, neodymium nitrate and europium nitrate are mixed in a solvent to obtain a metal salt solution, which is then heated and the pH of the metal salt solution is adjusted to alkaline. After the reaction, the solution is centrifuged, washed, dried, calcined and ground to obtain rare earth-doped zinc oxide.

[0016] Rare earth elements neodymium and europium are uniformly doped into the zinc oxide lattice in the form of ions, forming defect energy levels by replacing some zinc atoms, effectively regulating the band structure of zinc oxide; neodymium ions introduce intermediate energy levels, reducing the probability of electron-hole recombination and enhancing photocatalytic activity; the transition characteristics of europium ions optimize optical properties through the synergistic effect of ultraviolet absorption and visible light transmission; the nanoscale rare earth-doped zinc oxide crystals formed during the calcination process have a high specific surface area, and the surface hydroxyl groups form a dense network with the resin matrix through hydrogen bonds, filling the microscopic pores of the coating and blocking the penetration path of water molecules. The high refractive index of the nanoparticles and the resin matrix The rare earth doped zinc oxide forms a gradient refractive interface, which reduces light scattering loss and improves the refractive index; the oxygen vacancy defects induced by rare earth doping can capture ultraviolet rays and realize self-cleaning function by photocatalytically decomposing organic pollutants, while the lattice stability of the doped zinc oxide is enhanced, which inhibits the expansion of microcracks in the coating caused by high temperature or humidity changes and improves the weather resistance of the coating; the synergistic effect of rare earth doped zinc oxide and other components in the coating enhances the cohesion of the coating through hydrogen bonding and chemical coupling with fluorocarbon modified polysiloxane, and is dispersed in the resin matrix to photocatalytically decompose organic by-products produced by aging, thereby improving the waterproof and weather resistance.

[0017] Preferably, the mass ratio of the hydrophobically modified hollow mesoporous silica to the rare earth-doped zinc oxide in the highly permeable and waterproof filler is 1:(2-3).

[0018] The highly permeable and waterproof filler compounded according to the above mass ratio can effectively improve the light transmittance, waterproofness and weather resistance of the coating.

[0019] Preferably, in the preparation step of the rare earth-doped zinc oxide, the calcination step adopts gradient temperature calcination: heating to 250-350°C at a rate of 2-3°C / min, keeping warm for 20-40min, heating to 450-550°C at a rate of 4-6°C / min, keeping warm for 50-70min, heating to 600-700°C at a rate of 2.5-3.5°C / min, keeping warm for 1.5-2.5h, cooling to 350-450°C at a rate of 0.5-1.5°C / min, and then cooling naturally.

[0020] The gradient heating strategy regulates the lattice growth dynamics in stages; slowly heating and holding the temperature in the low temperature section promotes the decomposition of the organic precursor and retains the surface hydroxyl groups. These hydroxyl groups form a dense cross-linked network with the resin matrix through hydrogen bonds, filling the microscopic pores of the coating to block the penetration path of water molecules; rapid heating in the medium temperature section induces the directional growth of zinc oxide crystal nuclei to form a hexagonal crystal structure with uniform particle size. Its high specific surface area enhances the photocatalytic performance through surface active sites. At the same time, the regular arrangement of the grains reduces light scattering loss and improves the transmittance; long-term holding in the high temperature section promotes the deep solid solution of rare earth ions and zinc oxide lattice, broadens the visible light transmission window through the transition characteristics of europium ions, and uses the orbital intermediate energy level of neodymium ions to suppress electron-hole recombination and enhance the ultraviolet shielding efficiency; the segmented cooling process suppresses grain boundary cracks by relieving thermal stress, and combined with the oxygen vacancy defects induced by rare earth doping, improves the weather resistance of the coating.

[0021] Preferably, the film-forming aid includes alcohol ester and propylene glycol phenyl ether.

[0022] With its low water solubility, strong solvent properties and slow volatilization rate, alcohol ester twelve deeply swells the resin matrix and promotes the fusion of latex particles to form a continuous, dense, non-porous membrane layer, blocking the penetration path of water molecules; its isobutyrate group forms a hydrogen bond cross-linking network with the hydroxyl group of the mesoporous silica filler, enhancing the mechanical strength and peeling resistance of the coating; propylene glycol phenyl ether regulates the light refractive index gradient of the resin-filler interface through low surface tension and high wettability, reducing scattering loss to improve transmittance, and its rapid volatilization property accelerates surface drying film formation and reduces interface defects; the combination of the two produces a dynamic synergistic effect, the initial efficient volatilization of propylene glycol phenyl ether and the slow-release residue of alcohol ester twelve jointly optimize the cohesive strength of the coating, inhibit the expansion of microcracks caused by temperature and humidity changes, and improve the weather resistance of the coating.

[0023] Preferably, the stabilizer includes a benzotriazole ultraviolet absorber and a hindered amine light stabilizer.

[0024] Benzotriazole UV absorbers convert light energy into heat energy through the dynamic opening and closing of intramolecular hydrogen bonds, effectively blocking the damage of ultraviolet rays to the chemical bonds of the resin matrix while also having high light transmittance; hindered amine light stabilizers form a recycling system through a triple action mechanism of capturing free radicals, decomposing hydroperoxides, and quenching singlet oxygen, inhibiting photooxidation chain reactions, especially in weak areas at the edges of the coating or at the interface of the translucent substrate, delaying yellowing and mechanical property degradation through free radical scavenging and thermal oxidation stabilization; both work synergistically with the components in the coating to improve the weather resistance of the coating.

[0025] In the second aspect, the present application provides a paint surface protective film using a high-permeability waterproof coating, adopting the following technical solution: a paint surface protective film using a high-permeability waterproof coating, comprising a protective film, a high-permeability waterproof coating, a base film layer, an adhesive layer and a release film arranged in sequence, and the high-permeability waterproof coating is obtained by applying a high-permeability waterproof coating.

[0026] The high-permeability waterproof coating prepared by high-permeability waterproof coating can effectively improve the transmittance, waterproofness and weather resistance of the paint protection film.

[0027] In summary, this application includes at least one of the following beneficial technical effects: 1. Methyl polysiloxane resin is used as the main film-forming matrix. Its siloxane segments form a three-dimensional cross-linked network through hydrolysis and condensation, giving the coating flexibility and weather resistance. Fluorocarbon modified polysiloxane introduces perfluoroalkyl segments, which form a low surface energy hydrophobic layer on the siloxane skeleton through chemical bonding, and synergistically inhibit water molecule penetration with methyl polysiloxane. Acrylic resin enhances interfacial adhesion through esterification reaction between carboxyl groups and silanol groups, and interpenetrates with the siloxane network to form a rigid and flexible mechanical support. Nano-silica filler hydrogen bonds with the resin through surface hydroxyl groups. It fills micropores, and the synergistic effect of its micro-nano rough structure and fluorocarbon chains further enhances the hydrophobic performance; dispersants ensure uniform distribution of nanoparticles, film-forming aids optimize the solvent volatilization gradient, stabilizers inhibit phase separation, and defoamers and leveling agents synergistically eliminate interface defects; each component cooperates and synergizes with each other, the chemical bonding of fluorocarbon chains and siloxanes constructs a hydrophobic barrier, acrylic resin interpenetrates and cross-links to enhance network density, and the physical interlocking of nanofillers and resins forms a multi-level anti-penetration structure, ultimately achieving a simultaneous improvement in light transmittance and waterproof performance.

[0028] 2. Using trimethoxy-terminated polydimethylsiloxane as the skeleton, the siloxane active sites are activated through a pre-hydrolysis reaction under acidic conditions, and then perfluorooctylethyltrimethoxysilane and propyltrimethoxysilane are introduced. The former constructs a hydrophobic barrier through the extremely low surface energy characteristics of the perfluoroalkyl chain segment, while the latter provides reactive active sites through the acrylic acid group, forming a chemical bond with the siloxane network. In the resulting gradient molecular structure, the fluorocarbon segments are enriched on the surface to form a hydrophobic layer, while the siloxane network provides mechanical support and the acrylic acid group serves as a functional bridge to achieve improved waterproof performance and weather resistance.

[0029] 3. Rare earth elements neodymium and europium are uniformly doped into the zinc oxide lattice in the form of ions, forming defect energy levels by replacing some zinc atoms, effectively regulating the band structure of zinc oxide; neodymium ions introduce intermediate energy levels, reducing the probability of electron-hole recombination and enhancing photocatalytic activity; the transition characteristics of europium ions optimize optical properties through the synergistic effect of ultraviolet absorption and visible light transmission; the nanoscale rare earth-doped zinc oxide crystals formed during the calcination process have a high specific surface area, and the surface hydroxyl groups form a dense network with the resin matrix through hydrogen bonds, filling the microscopic pores of the coating and blocking the penetration path of water molecules. The high refractive index of the nanoparticles and the resin The matrix forms a gradient refractive interface, reducing light scattering loss and improving the refractive index; the oxygen vacancy defects induced by rare earth doping can capture ultraviolet rays and realize self-cleaning function through photocatalytic decomposition of organic pollutants, and the lattice stability of the doped zinc oxide is enhanced, which inhibits the expansion of microcracks in the coating caused by high temperature or humidity changes, and improves the weather resistance of the coating; the synergistic effect of rare earth doped zinc oxide and other components in the coating enhances the cohesion of the coating through hydrogen bonding and chemical coupling with fluorocarbon modified polysiloxane, and is dispersed in the resin matrix to photocatalytically decompose organic by-products produced by aging, thereby improving the waterproof and weather resistance. DETAILED DESCRIPTION

[0030] The present application discloses a highly permeable waterproof coating and its application in a paint protection film. The raw materials used in the present application can be obtained from commercially available raw materials unless otherwise specified. The present application is further described in detail below in conjunction with the examples: Raw materials description: trimethoxy-terminated polydimethylsiloxane (CAS No.: 142982-20-5), purchased from Jinjinle Chemical Co., Ltd., propylene glycol methyl ether acetate (CAS No.: 108-65-6), perfluorooctylethyltrimethoxysilane (CAS No.: 83048-65-1), propyltrimethoxysilane (CAS No.: 4369-14-6), methyl polysiloxane resin (product number xyh001), purchased from Hubei Xinyuhong Biopharmaceutical Technology Co., Ltd., acrylic acid The resin model is KR510, purchased from Dongguan Jianmeng Chemical Co., Ltd., the nano-silica product number is 100361, purchased from Jiangsu Xianfeng Nanomaterial Technology Co., Ltd., the dispersant BYK-163 was purchased from Hubei Langbowan Biomedicine Co., Ltd., alcohol ester dodecahydrate (CAS number: 25265-77-4), propylene glycol phenyl ether (CAS number: 770-35-4), benzotriazole UV absorber UV-326 was purchased from Nanjing Huabang New Materials Co., Ltd., hindered amine light stabilizer Tinuvin 770 was purchased from Yihongdi New Materials Technology (Shanghai) Co., Ltd., defoamer BYK-1790 was purchased from Ningbo Huiwangcheng Plastics Co., Ltd., leveling agent TEGO Glide 410 was purchased from Shanghai Mengdihu Industrial Co., Ltd., hollow mesoporous silica product number is 102887, purchased from Jiangsu Xianfeng Nanomaterial Technology Co., Ltd., γ-methacryloxypropyltrimethoxysilane (CAS number: 2530-85-0).

[0031] Example 1 Preparation of fluorocarbon-modified polysiloxane Weigh 10 g of trimethoxy-terminated polydimethylsiloxane, 100 mL of propylene glycol methyl ether acetate, 1.9 g of perfluorooctylethyltrimethoxysilane, 0.8 g of propyltrimethoxysilane, and 5 mL of deionized water.

[0032] Under nitrogen protection, trimethoxy-terminated polydimethylsiloxane was added to propylene glycol methyl ether acetate, stirred and dissolved at 60°C at a speed of 200 rpm, and a mixture of perfluorooctylethyltrimethoxysilane and propyltrimethoxysilane was added. The pH was adjusted to 4 with 0.1 mol / L hydrochloric acid, pre-hydrolyzed for 2 hours, heated to 80°C, deionized water was added, and the reaction was carried out for 4 hours. The pH was adjusted to neutral, the solvent was removed by rotary evaporation, and the mixture was purified by n-hexane precipitation and vacuum dried at 60°C to obtain fluorosilicone-modified polysiloxane.

[0033] Preparation of highly permeable waterproof coating Weigh 35g methyl polysiloxane resin, 3g fluorocarbon modified polysiloxane, 8g acrylic resin, 15g high-permeability waterproof filler, 1g dispersant, 1g film-forming agent, 0.5g stabilizer, 1g defoamer, 1g leveling agent, and 10g solvent. The high-permeability waterproof filler is nano-silica with a particle size of 50nm. The dispersant is BYK-163. The film-forming agent is composed of alcohol ester dodecahydrate and propylene glycol phenyl ether in a mass ratio of 1:1. The stabilizer is composed of benzotriazole ultraviolet absorber UV-326 and hindered amine light stabilizer Tinuvin 770 in a mass ratio of 1:2. The defoamer is BYK-1790, the leveling agent is TEGO Glide 410, and the solvent is propylene glycol methyl ether acetate.

[0034] Methyl polysiloxane resin, fluorocarbon modified polysiloxane and acrylic resin are mixed into a solvent, a film-forming aid and a stabilizer are added, and the mixture is stirred at 60°C at a speed of 500 rpm for 30 minutes. High-permeability waterproof filler and dispersant are added in sequence, and premixed at a speed of 2000 rpm. The mixture is then transferred to a sand mill and ground to a particle size of D50 ≤ 50 nm. A defoamer and a leveling agent are added, and the mixture is stirred at a speed of 200 rpm for 20 minutes. The mixture is vacuum degassed at -0.08 MPa for 20 minutes to obtain a high-permeability waterproof coating.

[0035] Preparation of paint protection film using high-permeability waterproof coating The paint protection film includes a protective film, a high-permeability waterproof coating, a base film layer, an adhesive layer and a release film arranged in sequence. The high-permeability waterproof coating is obtained by coating a high-permeability waterproof coating: the high-permeability waterproof coating is sprayed on the base film layer, and after UV curing and heat curing, a high-permeability waterproof coating is obtained.

[0036] Example 2 Preparation of fluorocarbon-modified polysiloxane Weigh 10 g of trimethoxy-terminated polydimethylsiloxane, 100 mL of propylene glycol methyl ether acetate, 2.5 g of perfluorooctylethyltrimethoxysilane, 0.8 g of propyltrimethoxysilane, and 5 mL of deionized water.

[0037] Under nitrogen protection, trimethoxy-terminated polydimethylsiloxane was added to propylene glycol methyl ether acetate, stirred and dissolved at 60°C at a speed of 200 rpm, and a mixture of perfluorooctylethyltrimethoxysilane and propyltrimethoxysilane was added. The pH was adjusted to 4 with 0.1 mol / L hydrochloric acid, pre-hydrolyzed for 2 hours, heated to 80°C, deionized water was added, and the reaction was carried out for 4 hours. The pH was adjusted to neutral, the solvent was removed by rotary evaporation, and the mixture was purified by n-hexane precipitation and vacuum dried at 60°C to obtain fluorosilicone-modified polysiloxane.

[0038] Preparation of highly permeable waterproof coating Weigh 65g methyl polysiloxane resin, 5g fluorocarbon modified polysiloxane, 12g acrylic resin, 20g high permeability waterproof filler, 3g dispersant, 3g film-forming agent, 1g stabilizer, 2g defoamer, 3g leveling agent, and 20g solvent. The high permeability waterproof filler is nano-silica with a particle size of 50nm. The dispersant is BYK-163. The film-forming agent is composed of alcohol ester dodecahydrate and propylene glycol phenyl ether in a mass ratio of 1:1. The stabilizer is composed of benzotriazole ultraviolet absorber UV-326 and hindered amine light stabilizer Tinuvin 770 in a mass ratio of 1:2. The defoamer is BYK-1790, the leveling agent is TEGO Glide 410, and the solvent is propylene glycol methyl ether acetate.

[0039] Methyl polysiloxane resin, fluorocarbon modified polysiloxane and acrylic resin are mixed into a solvent, a film-forming aid and a stabilizer are added, and the mixture is stirred at 60°C at a speed of 500 rpm for 30 minutes. High-permeability waterproof filler and dispersant are added in sequence, and premixed at a speed of 2000 rpm. The mixture is then transferred to a sand mill and ground to a particle size of D50 ≤ 50 nm. A defoamer and a leveling agent are added, and the mixture is stirred at a speed of 200 rpm for 20 minutes. The mixture is vacuum degassed at -0.08 MPa for 20 minutes to obtain a high-permeability waterproof coating.

[0040] Preparation of paint protection film using high-permeability waterproof coating The paint protection film includes a protective film, a high-permeability waterproof coating, a base film layer, an adhesive layer and a release film arranged in sequence. The high-permeability waterproof coating is obtained by coating a high-permeability waterproof coating: the high-permeability waterproof coating is sprayed on the base film layer, and after UV curing and heat curing, a high-permeability waterproof coating is obtained.

[0041] Example 3 Preparation of fluorocarbon-modified polysiloxane Weigh 10 g of trimethoxy-terminated polydimethylsiloxane, 100 mL of propylene glycol methyl ether acetate, 2.2 g of perfluorooctylethyltrimethoxysilane, 0.8 g of propyltrimethoxysilane, and 5 mL of deionized water.

[0042] Under nitrogen protection, trimethoxy-terminated polydimethylsiloxane was added to propylene glycol methyl ether acetate, stirred and dissolved at 60°C at a speed of 200 rpm, and a mixture of perfluorooctylethyltrimethoxysilane and propyltrimethoxysilane was added. The pH was adjusted to 4 with 0.1 mol / L hydrochloric acid, pre-hydrolyzed for 2 hours, heated to 80°C, deionized water was added, and the reaction was carried out for 4 hours. The pH was adjusted to neutral, the solvent was removed by rotary evaporation, and the mixture was purified by n-hexane precipitation and vacuum dried at 60°C to obtain fluorosilicone-modified polysiloxane.

[0043] Preparation of highly permeable waterproof coating Weigh 50g methyl polysiloxane resin, 4g fluorocarbon modified polysiloxane, 10g acrylic resin, 17.5g high-permeability waterproof filler, 2g dispersant, 2g film-forming agent, 0.75g stabilizer, 1.5g defoamer, 2g leveling agent, and 15g solvent. The high-permeability waterproof filler is nano-silica with a particle size of 50nm. The dispersant is BYK-163. The film-forming agent is composed of alcohol ester dodecahydrate and propylene glycol phenyl ether in a mass ratio of 1:1. The stabilizer is composed of a benzotriazole ultraviolet absorber UV-326 and a hindered amine light stabilizer Tinuvin 770 in a mass ratio of 1:2. The defoamer is BYK-1790, the leveling agent is TEGO Glide 410, and the solvent is propylene glycol methyl ether acetate.

[0044] Methyl polysiloxane resin, fluorocarbon modified polysiloxane and acrylic resin are mixed into a solvent, a film-forming aid and a stabilizer are added, and the mixture is stirred at 60°C at a speed of 500 rpm for 30 minutes. High-permeability waterproof filler and dispersant are added in sequence, and premixed at a speed of 2000 rpm. The mixture is then transferred to a sand mill and ground to a particle size of D50 ≤ 50 nm. A defoamer and a leveling agent are added, and the mixture is stirred at a speed of 200 rpm for 20 minutes. The mixture is vacuum degassed at -0.08 MPa for 20 minutes to obtain a high-permeability waterproof coating.

[0045] Preparation of paint protection film using high-permeability waterproof coating The paint protection film includes a protective film, a high-permeability waterproof coating, a base film layer, an adhesive layer and a release film arranged in sequence. The high-permeability waterproof coating is obtained by coating a high-permeability waterproof coating: the high-permeability waterproof coating is sprayed on the base film layer, and after UV curing and heat curing, a high-permeability waterproof coating is obtained.

[0046] Example 4 Example 4 is based on Example 3. The only difference between Example 4 and Example 3 is that in Example 4, the mass ratio of trimethoxy-terminated polydimethylsiloxane, perfluorooctylethyltrimethoxysilane and propyltrimethoxysilane is 1:0.15:0.08.

[0047] Example 5 Example 5 is based on Example 3. The only difference between Example 5 and Example 3 is that in Example 5, the mass ratio of trimethoxy-terminated polydimethylsiloxane, perfluorooctylethyltrimethoxysilane and propyltrimethoxysilane is 1:0.3:0.08.

[0048] Example 6 Example 6 is based on Example 3. The only difference between Example 6 and Example 3 is that in Example 6, nano-silica is replaced by hollow mesoporous silica.

[0049] Example 7 Example 7 is based on Example 6. The only difference between Example 7 and Example 6 is that the hollow mesoporous silica in Example 7 is modified and prepared by the following steps: 50 g of hollow mesoporous silica and 5 g of γ-methacryloxypropyltrimethoxysilane were weighed, and the solvent was 200 mL of toluene.

[0050] The hollow mesoporous silica and γ-methacryloyloxypropyltrimethoxysilane were mixed in a solvent, and after ultrasonication for 30 minutes, the pH was adjusted to 4 using glacial acetic acid, and pre-hydrolyzed at a speed of 200 rpm for 30 minutes. The temperature was raised to 80°C and refluxed at a speed of 200 rpm for 4 hours. After the reaction was completed, it was cooled, washed with anhydrous ethanol and deionized water, and vacuum dried at 60°C to obtain hydrophobically modified hollow mesoporous silica.

[0051] Example 8 Example 8 is based on Example 7. The only difference between Example 8 and Example 7 is that the high-permeability waterproof filler in Example 8 further includes rare earth-doped zinc oxide. The high-permeability waterproof filler is composed of a mixture of hydrophobically modified hollow mesoporous silica and rare earth-doped zinc oxide in a mass ratio of 1:2. The rare earth-doped zinc oxide is prepared by the following steps: Weigh 45.1 g of zinc acetate, 1.62 g of neodymium nitrate, 0.55 g of europium nitrate, and 200 mL of a solvent, wherein the solvent is deionized water and the concentration of ammonia water is 30%.

[0052] Zinc acetate, neodymium nitrate and europium nitrate are mixed in a solvent to obtain a metal salt solution, which is heated to 70°C, and the pH of the metal salt solution is adjusted to 9.5 with ammonia water. The solution is stirred at a speed of 200 rpm for 1 hour, and centrifuged to obtain a precipitate. The precipitate is alternately washed with deionized water and anhydrous ethanol, and then vacuum-dried at 80°C for 4 hours. The temperature is increased to 600°C in a muffle furnace at a speed of 5°C / min and calcined for 3 hours. After cooling, the solution is ball-milled to a particle size D50 ≤ 50 nm to obtain rare earth-doped zinc oxide.

[0053] Example 9 Example 9 is based on Example 8. The only difference between Example 9 and Example 8 is that the high-permeability waterproof filler in Example 9 is composed of a mixture of hydrophobically modified hollow mesoporous silica and rare earth-doped zinc oxide in a mass ratio of 1:3.

[0054] Example 10 Example 10 is based on Example 8. The only difference between Example 10 and Example 8 is that the high-permeability waterproof filler in Example 10 is composed of a mixture of hydrophobically modified hollow mesoporous silica and rare earth-doped zinc oxide in a mass ratio of 1:2.5.

[0055] Example 11 Example 11 is based on Example 8. The only difference between Example 11 and Example 8 is that the high-permeability waterproof filler in Example 11 is composed of a mixture of hydrophobically modified hollow mesoporous silica and rare earth-doped zinc oxide in a mass ratio of 1:1.

[0056] Example 12 Example 12 is based on Example 8. The only difference between Example 12 and Example 8 is that the high-permeability waterproof filler in Example 12 is composed of a mixture of hydrophobically modified hollow mesoporous silica and rare earth-doped zinc oxide in a mass ratio of 1:4.

[0057] Example 13 Example 13 is based on Example 8. The only difference between Example 13 and Example 8 is that in the preparation step of rare earth-doped zinc oxide in Example 13, the calcination step adopts gradient temperature calcination.

[0058] Weigh 45.1 g of zinc acetate, 1.62 g of neodymium nitrate, 0.55 g of europium nitrate, and 200 mL of a solvent, wherein the solvent is deionized water and the concentration of ammonia water is 30%.

[0059] Zinc acetate, neodymium nitrate and europium nitrate are mixed in a solvent to obtain a metal salt solution, which is heated to 70°C, and the pH of the metal salt solution is adjusted to 9.5 with ammonia water. The solution is stirred at a speed of 200 rpm for 1 hour, and centrifuged to obtain a precipitate. The precipitate is alternately washed with deionized water and anhydrous ethanol, and then vacuum-dried at 80°C for 4 hours. The temperature is increased to 250°C at a rate of 2°C / min in a muffle furnace, and kept warm for 40 minutes. The temperature is increased to 450°C at a rate of 4°C / min, and kept warm for 70 minutes. The temperature is increased to 600°C at a rate of 2.5°C / min, and kept warm for 2.5 hours. The temperature is decreased to 350°C at a rate of 0.5°C / min, and then naturally cooled and ball-milled to a particle size D50 ≤ 50 nm to obtain rare earth-doped zinc oxide.

[0060] Example 14 Example 14 is based on Example 8. The only difference between Example 14 and Example 8 is that in the preparation step of rare earth-doped zinc oxide in Example 14, the calcination step adopts gradient temperature calcination.

[0061] Weigh 45.1 g of zinc acetate, 1.62 g of neodymium nitrate, 0.55 g of europium nitrate, and 200 mL of a solvent, wherein the solvent is deionized water and the concentration of ammonia water is 30%.

[0062] Zinc acetate, neodymium nitrate and europium nitrate are mixed in a solvent to obtain a metal salt solution, which is heated to 70°C, and the pH of the metal salt solution is adjusted to 9.5 with ammonia water. The solution is stirred at a speed of 200 rpm for 1 hour, and centrifuged to obtain a precipitate. The precipitate is alternately washed with deionized water and anhydrous ethanol, and then vacuum-dried at 80°C for 4 hours. The temperature is increased to 350°C at a rate of 3°C / min in a muffle furnace, and kept warm for 20 minutes. The temperature is increased to 550°C at a rate of 6°C / min, and kept warm for 50 minutes. The temperature is increased to 700°C at a rate of 3.5°C / min, and kept warm for 1.5 hours. The temperature is decreased to 450°C at a rate of 1.5°C / min, and then naturally cooled and ball-milled to a particle size D50 ≤ 50 nm to obtain rare earth-doped zinc oxide.

[0063] Example 15 Example 15 is based on Example 8. The only difference between Example 15 and Example 8 is that in the preparation step of rare earth-doped zinc oxide in Example 15, the calcination step adopts gradient temperature calcination.

[0064] Weigh 45.1 g of zinc acetate, 1.62 g of neodymium nitrate, 0.55 g of europium nitrate, and 200 mL of a solvent, wherein the solvent is deionized water and the concentration of ammonia water is 30%.

[0065] Zinc acetate, neodymium nitrate and europium nitrate are mixed in a solvent to obtain a metal salt solution, which is heated to 70°C, and the pH of the metal salt solution is adjusted to 9.5 with ammonia water. The solution is stirred at a speed of 200 rpm for 1 hour, and the solution is centrifuged to obtain a precipitate. The precipitate is alternately washed with deionized water and anhydrous ethanol, and then vacuum-dried at 80°C for 4 hours. The solution is heated to 300°C at a speed of 2.5°C / min in a muffle furnace, and kept warm for 30 minutes. The temperature is then increased to 500°C at a speed of 5°C / min, and kept warm for 60 minutes. The temperature is then increased to 650°C at a speed of 3°C / min, and kept warm for 2 hours. The solution is cooled to 400°C at a speed of 1°C / min, and then naturally cooled and ball-milled to a particle size D50 ≤ 50 nm to obtain rare earth-doped zinc oxide.

[0066] Comparative Example 1 Comparative Example 1 is based on Example 3. The only difference between Comparative Example 1 and Example 3 is that fluorocarbon-modified polysiloxane is not added in Comparative Example 1, and the fluorocarbon-modified polysiloxane is replaced by an equal amount of methyl polysiloxane resin.

[0067] Preparation of highly permeable waterproof coating Weigh 54g methyl polysiloxane resin, 10g acrylic resin, 17.5g high-permeability waterproof filler, 2g dispersant, 2g film-forming agent, 0.75g stabilizer, 1.5g defoamer, 2g leveling agent, and 15g solvent. The high-permeability waterproof filler is nano-silica with a particle size of 50nm. The dispersant is BYK-163. The film-forming agent is composed of alcohol ester dodecahydrate and propylene glycol phenyl ether in a mass ratio of 1:1. The stabilizer is composed of benzotriazole ultraviolet absorber UV-326 and hindered amine light stabilizer Tinuvin 770 in a mass ratio of 1:2. The defoamer is BYK-1790, the leveling agent is TEGO Glide 410, and the solvent is propylene glycol methyl ether acetate.

[0068] Mix methyl polysiloxane resin and acrylic resin into propylene glycol methyl ether acetate, add film-forming aid and stabilizer, stir and mix at 60°C at 500 rpm for 30 minutes, add high-permeability waterproof filler and dispersant in sequence, premix at 2000 rpm, transfer to a sand mill and grind to a particle size D50 ≤ 50 nm, add defoamer and leveling agent, stir at 200 rpm for 20 minutes, and vacuum degas at -0.08 MPa for 20 minutes to obtain a high-permeability waterproof coating.

[0069] Preparation of paint protection film using high-permeability waterproof coating The paint protection film includes a protective film, a high-permeability waterproof coating, a base film layer, an adhesive layer and a release film arranged in sequence. The high-permeability waterproof coating is obtained by coating a high-permeability waterproof coating: the high-permeability waterproof coating is sprayed on the base film layer, and after UV curing and heat curing, a high-permeability waterproof coating is obtained.

[0070] Performance testing (1) Select "GB / T2410-2008 Transparent Plastics - Determination of Light Transmittance and Haze" as the standard, evenly coat the sample on a transparent glass substrate, control the dry film thickness to be 10 μm, and leave it to stand for 7 days (25 ° C, relative humidity 50%) to obtain the sample. Use a spectrophotometer to measure the light transmittance in the wavelength range of 400-800 nm. Each sample is tested three times, and the average value is taken after measurement. The results are recorded in Table 1; Select "GB / T1865-2009 Paints and varnishes - Artificial weathering and artificial radiation exposure filtered xenon arc radiation" as the standard, put the sample into a xenon arc lamp aging test box, set the irradiance (340 nm) to 0.55 W / m 2 , blackboard temperature 65℃, relative humidity 65%, continuous exposure 500h, test the transmittance of the sample after aging, each sample is tested three times, and the average value is taken after measurement. The results are recorded in Table 1.

[0071] (2) GB / T16777-2008 Test Method for Building Waterproof Coatings was selected as the standard. The sample was prepared into a coating film (dry film thickness 1.5 mm). After curing for 7 days, it was placed on a watertightness tester and a water pressure of 0.3 MPa was applied for 30 minutes. The leakage was observed and the results were recorded in Table 1.

[0072] Table 1 Test results of light transmittance, waterproof performance and weather resistance of high-transmittance waterproof coatings Test results Light transmittance (%) Transmittance after aging (%) Waterproof performance Example 1 92.6 87.7 No leakage Example 2 92.4 87.5 No leakage Example 3 93.1 88.3 No leakage Example 4 92.1 86.9 No leakage Example 5 91.8 86.5 No leakage Example 6 93.6 89.1 No leakage Example 7 93.9 89.5 No leakage Example 8 94.3 89.8 No leakage Example 9 94.2 89.6 No leakage Example 10 94.5 90.1 No leakage Example 11 94.1 89.3 No leakage Example 12 94.0 89.6 No leakage Example 13 94.7 90.9 No leakage Example 14 94.6 90.8 No leakage Example 15 94.9 91.5 No leakage Comparative Example 1 89.3 78.5 leakage As can be seen from Table 1, the light transmittance of Examples 1-3 is greater than 92.4%, the light transmittance after aging is greater than 87.5%, the waterproof performance is good, and there is no leakage. It can be seen that the high-permeability waterproof coating prepared in this application has good light transmittance, waterproof performance and weather resistance.

[0073] As can be seen from Table 1, the only difference between Examples 4 and 5 and Example 3 is that the mass ratio of trimethoxy-terminated polydimethylsiloxane, perfluorooctylethyltrimethoxysilane and propyltrimethoxysilane in Example 4 is 1:0.15:0.08, and the mass ratio of trimethoxy-terminated polydimethylsiloxane, perfluorooctylethyltrimethoxysilane and propyltrimethoxysilane in Example 5 is 1:0.3:0.08. Compared with Example 3, the performance of Examples 4 and 5 is reduced; this is because the optimal ratio of fluorosilicone-modified polysiloxane is destroyed. Too much or too little perfluorosilane will cause performance imbalance, resulting in defects, thereby reducing performance.

[0074] As can be seen from Table 1, the only difference between Examples 6 and 7 and Example 3 is that in Example 6, nano-silica is replaced with hollow mesoporous silica, and in Example 7, the hollow mesoporous silica is further hydrophobically modified. Compared with Example 3, the performance of Examples 6 and 7 is improved; this is because hollow mesoporous silica can reduce interface reflection loss and improve the transmittance of the coating; after the hydrophobic modification treatment, the interface bonding strength is improved, and the light transmittance and weather resistance are further improved.

[0075] As can be seen from Table 1, the only difference between Examples 8-12 and Example 7 is that rare earth-doped zinc oxide is added to the high-permeability waterproof filler in Examples 8-12, and the ratio between the two is optimized; compared with Example 7, the performance of Examples 8-10 is improved. This is because within the limited ratio range, rare earth-doped zinc oxide can achieve a good synergistic effect with hollow mesoporous silica, thereby improving the performance; Examples 11 and 12 violate the limited range of the optimal ratio, and the performance is reduced.

[0076] As can be seen from Table 1, the only difference between Examples 13-15 and Example 3 is that the preparation steps of rare earth-doped zinc oxide are further optimized in Examples 13-15, and gradient temperature calcination is used. Compared with Example 3, the performance of Examples 13-15 is improved. This is because gradient temperature calcination can optimize the crystal phase structure of rare earth-doped zinc oxide and further improve the weather resistance and light transmittance of the coating.

[0077] As can be seen from Table 1, the only difference between Comparative Example 1 and Example 3 is that no fluorocarbon-modified polysiloxane is added in Comparative Example 1. Compared with Example 3, the performance of Comparative Example 1 is reduced. This is because without the addition of fluorocarbon-modified polysiloxane, the surface energy of the coating increases, the UV shielding effect is lacking, and the molecular chain is more susceptible to oxidation and breakage, resulting in a significant reduction in performance.

[0078] This specific embodiment is merely an explanation of the present application and does not limit the present application. Based on the above description, relevant personnel can make various changes and modifications without departing from the technical scope of the present application. The technical scope of the present application is not limited to the contents of the specification and must be determined according to the scope of the claims.

Claims

1. A highly permeable waterproof coating, characterized by: The composition includes the following parts by weight: 35-65 parts of methyl polysiloxane resin 3-5 parts of fluorocarbon modified polysiloxane 8-12 parts of acrylic resin 15-20 parts of high permeability waterproof filler 1-3 parts dispersant 1-3 parts of film-forming aid 0.5-1 part stabilizer 1-2 parts defoaming agent 1-3 parts of leveling agent 10-20 parts of solvent; The fluorocarbon-modified polysiloxane is prepared by the following steps: A mixture of perfluorooctylethyltrimethoxysilane and propyltrimethoxysilane was added to a trimethoxy-terminated polydimethylsiloxane solution, the pH was adjusted to acidic, water was added after pre-hydrolysis, and the mixture was heated and stirred for reaction. After the reaction was completed, the pH was adjusted to neutral, and the mixture was rotary evaporated and purified to obtain a fluorocarbon-modified polysiloxane. The highly permeable and waterproof filler comprises nano silicon dioxide.

2. A highly permeable waterproof coating according to claim 1, characterized in that: The mass ratio of the trimethoxy-terminated polydimethylsiloxane, perfluorooctylethyltrimethoxysilane and acrylatepropyltrimethoxysilane is 1:(0.19-0.25):0.

08.

3. The highly permeable waterproof coating according to claim 1, characterized in that: The nano-silica is replaced by hollow mesoporous silica.

4. The highly permeable waterproof coating according to claim 3, characterized in that: The hollow mesoporous silica is modified and prepared by the following steps: The hollow mesoporous silica and γ-methacryloxypropyltrimethoxysilane are mixed in a solvent, the pH is adjusted to acidic, pre-hydrolyzed, heated and stirred for reaction, and after the reaction is completed, cooled, washed and dried to obtain hydrophobically modified hollow mesoporous silica.

5. The highly permeable waterproof coating according to claim 4, characterized in that: The highly permeable and waterproof filler further comprises rare earth-doped zinc oxide, which is prepared by the following steps: Zinc acetate, neodymium nitrate and europium nitrate are mixed in a solvent to obtain a metal salt solution, which is then heated and the pH of the metal salt solution is adjusted to alkaline. After the reaction, the solution is centrifuged, washed, dried, calcined and ground to obtain rare earth-doped zinc oxide.

6. The highly permeable waterproof coating according to claim 5, characterized in that: The mass ratio of the hydrophobically modified hollow mesoporous silica to the rare earth-doped zinc oxide in the highly permeable and waterproof filler is 1:(2-3).

7. The highly permeable waterproof coating according to claim 5, characterized in that: In the preparation step of the rare earth-doped zinc oxide, the calcination step adopts a gradient temperature increase calcination: heating to 250-350°C at a rate of 2-3°C / min, keeping warm for 20-40 minutes, heating to 450-550°C at a rate of 4-6°C / min, keeping warm for 50-70 minutes, heating to 600-700°C at a rate of 2.5-3.5°C / min, keeping warm for 1.5-2.5 hours, cooling to 350-450°C at a rate of 0.5-1.5°C / min, and then cooling naturally.

8. The highly permeable waterproof coating according to claim 1, characterized in that: The film-forming aids include alcohol ester and propylene glycol phenyl ether.

9. The highly permeable waterproof coating according to claim 1, characterized in that: The stabilizer includes a benzotriazole ultraviolet absorber and a hindered amine light stabilizer.

10. A paint protection film using the highly permeable waterproof coating according to any one of claims 1 to 9, characterized in that: The invention comprises a protective film, a high-permeability waterproof coating, a base film layer, an adhesive layer and a release film which are arranged in sequence. The high-permeability waterproof coating is obtained by coating a high-permeability waterproof paint.