Hard coat silicone coating and method of making and use thereof

Abstract

This disclosure provides a hard-film polysiloxane coating, its preparation method, and its application. The method for preparing the hard-film polysiloxane coating includes: reacting an epoxy resin and / or a modified epoxy resin with a first silane coupling agent to form a silane coupling agent-modified epoxy resin; mixing the silane coupling agent-modified epoxy resin with a polysiloxane containing active end groups, allowing the silane coupling agent in the silane coupling agent-modified epoxy resin to react with the polysiloxane containing active end groups; then adding a curing agent and stirring to form a preliminary mixture; adding a functional filler to the preliminary mixture and stirring to form a composite adhesive; and adding a second silane coupling agent and a catalyst to the composite adhesive and mixing to obtain the coating. In the hard-film polysiloxane coating of this disclosure, the epoxy resin and / or the modified epoxy resin are coupled together with the polysiloxane containing active end groups via a coupling agent to form a multi-layer crosslinked network structure, and functional fillers are filled into the multi-layer crosslinked network structure.

Description

Technical Field

[0001] This disclosure belongs to the field of coating technology, and particularly relates to a hard film polysiloxane coating, its preparation method and application, and more specifically to a hard film polysiloxane coating without volatile organic compounds, its preparation method and application. Background Technology

[0002] Polysiloxane coatings have low hardness and relatively low film adhesion, making them prone to damage and peeling in harsh environments (such as extreme cold). Currently, the main methods to address the low hardness and adhesion of polysiloxane coatings are the addition of adhesion promoters and fillers. While adhesion promoters can improve adhesion between the paint and the substrate, they are relatively soft, offering limited increase in film hardness. Furthermore, due to solubility issues, organic solvents are usually required to form a uniform film. In addition, polysiloxanes have poor compatibility with most inorganic fillers, and excessive addition may affect the light transmittance and film-forming behavior of the coating. Summary of the Invention

[0003] To address the aforementioned technical problems, this disclosure provides a hard film polysiloxane coating, its preparation method, and its application, aiming to at least partially solve the above-mentioned technical problems.

[0004] As a first aspect of this disclosure, a hard film polysiloxane coating is provided, wherein the coating has a multi-crosslinked network structure formed by an epoxy resin and / or a modified epoxy resin and a polysiloxane containing active end groups, and a functional filler filled in the multi-crosslinked network structure, wherein the epoxy resin and / or the modified epoxy resin and the polysiloxane containing active end groups are coupled together by a coupling agent.

[0005] As a second aspect of this disclosure, a method for preparing a hard-film polysiloxane coating is provided, comprising:

[0006] Epoxy resin and / or modified epoxy resin are reacted with a first silane coupling agent to form a silane coupling agent modified epoxy resin.

[0007] Silane coupling agent modified epoxy resin and polysiloxane containing active end groups are mixed to allow the silane coupling agent in the silane coupling agent modified epoxy resin to react with the polysiloxane containing active end groups. Then, a curing agent is added and stirred to form a preliminary mixture.

[0008] Functional fillers are added to the initial mixture and stirred to form a composite adhesive;

[0009] A second silane coupling agent and a catalyst are added to the composite adhesive and mixed and stirred to obtain a coating.

[0010] The types and amounts of the first and second silane coupling agents may be the same or different.

[0011] As a third aspect of this disclosure, the application of hard film polysiloxane coatings in ice-repellent coatings, marine antifouling coatings, building protective coatings, and anti-corrosion coatings is provided.

[0012] According to the embodiments of this disclosure, the hard film polysiloxane coating, its preparation method, and its application provided by this disclosure have at least one of the following beneficial effects:

[0013] (1) In the embodiments of this disclosure, the rigidity of epoxy resin, the toughness and wear resistance of modified epoxy resin, and the low surface energy of polysiloxane with active end groups are utilized. Epoxy resin and / or modified epoxy resin are coupled to polysiloxane with active end groups via a silane coupling agent to form a multi-layered cross-linked network structure. Functional fillers are also filled into this multi-layered cross-linked network structure. After drying and curing, the resulting coating exhibits toughness, adhesion, enhanced hardness, and wear resistance, forming a polysiloxane coating. Furthermore, the low surface energy of this coating significantly improves the hydrophobicity of the cured coating surface. By adjusting the type and amount of functional fillers in the coating, it exhibits superior properties, expanding the application range of hard-film polysiloxane coatings.

[0014] (2) In the embodiments of this disclosure, epoxy resin and / or modified epoxy resin are reacted with a first silane coupling agent, causing the epoxy groups in the epoxy resin and / or modified epoxy resin to react with the groups (such as amino groups) in the first silane coupling agent to form a silane coupling agent modified epoxy resin. Subsequently, the silane coupling agent modified epoxy resin and a polysiloxane containing active end groups are mixed, causing the silane coupling agent in the silane coupling agent modified epoxy resin to undergo hydrolysis and react with the polysiloxane containing active end groups. Then, a curing agent is added and stirred, causing a portion of the added curing agent to react with the epoxy resin in the silane coupling agent modified epoxy resin to form a preliminary mixture. Functional fillers are added to the preliminary mixture and stirred to form a composite adhesive, giving the composite adhesive certain functions. Finally, a second silane coupling agent and a catalyst are added to the composite adhesive, allowing the second silane coupling agent to react with the epoxy resin in the composite adhesive. Simultaneously, the siloxane coupled to the epoxy resin undergoes hydrolysis under the promotion of the catalyst to form a high-density cross-linked network, thereby obtaining a coating. The obtained coating has a multi-layer cross-linked network structure and functional fillers filling the multi-layer cross-linked network structure.

[0015] (3) In the embodiments of this disclosure, the coating has a low preparation cost and a simple process, and is easy to form an operation line. Detailed Implementation

[0016] To make the objectives, technical solutions, and advantages of this disclosure clearer, the following detailed description is provided in conjunction with specific embodiments.

[0017] Currently, polysiloxane coatings have low hardness, making them easily damaged, and their adhesion is also relatively weak, leading to frequent peeling. This presents several problems when applied to marine antifouling coatings, ice-repellent coatings, and architectural protective coatings. For example, when using low-surface-energy polysiloxane coatings as marine antifouling coatings, their low hardness makes them prone to scratches and damage in sandy or coastal areas. The low adhesion also causes paint film peeling during high-speed ship navigation. When used as ice-repellent coatings in applications such as wind power generation and helicopter blades, the low hardness makes the coating susceptible to scratches, peeling, and flaking in windy, sandy, and cavitation environments. Furthermore, coatings with low hardness and adhesion are unlikely to reach their designed service life, thus increasing overall maintenance costs and labor. In related technologies, although adding accelerators and fillers with certain adhesion can solve the problems of low hardness and adhesion, it also has problems such as soft coating texture and poor compatibility between polysiloxane and fillers, which affect its practical application.

[0018] In response, this disclosure proposes to couple epoxy resin and / or modified epoxy resin with polysiloxanes having active end groups using a coupling agent, and to add functional fillers during the preparation process. This forms a multi-layered cross-linked network structure while simultaneously filling the multi-layered cross-linked network structure with functional fillers, thereby giving the obtained hard film polysiloxane coating a certain degree of hardness and adhesion. This addresses the problem of low adhesion and hardness in current polysiloxane coatings. Furthermore, the method for preparing hard film polysiloxane coatings in this disclosure is simple and free of volatile organic compounds.

[0019] Specifically, this disclosure provides a hard film polysiloxane coating having a multi-crosslinked network structure formed by epoxy resin and / or modified epoxy resin and polysiloxane containing active end groups, and a functional filler filled in the multi-crosslinked network structure, wherein the epoxy resin and / or modified epoxy resin and polysiloxane containing active end groups are coupled together by a coupling agent.

[0020] In the embodiments of this disclosure, the rigidity of epoxy resin and the low surface energy of polysiloxanes containing active end groups are utilized to couple epoxy resin and polysiloxanes containing active end groups using a coupling agent, forming a multi-layer cross-linked network structure. This increases the rigidity of the coating, thereby improving its strength. Utilizing the toughness of epoxy resin, modified epoxy resin and polysiloxanes containing active end groups are coupled using a silane coupling agent, also forming a multi-layer cross-linked network. Introducing functional fillers into the polysiloxane coating can improve its elasticity, abrasion resistance, or other properties. Coupling epoxy resin and modified epoxy resin with polysiloxanes containing active end groups yields a coating that possesses high hardness while also exhibiting certain toughness and abrasion resistance. Furthermore, the coatings provided in this disclosure can form a glossy film within 1-3 days after airless spraying.

[0021] According to embodiments of this disclosure, the weight ratio of epoxy resin and / or modified epoxy resin to polysiloxane containing active end groups is between 5:1 and 1:2.

[0022] According to embodiments of this disclosure, the coating is prepared from the following components: 20-150 parts of epoxy resin and / or modified epoxy resin; 10-80 parts of polysiloxane containing active end groups; 0.01-1 part of catalyst; 0.1-20 parts of functional filler; 5-40 parts of curing agent; and 5-30 parts of first silane coupling agent and / or second silane coupling agent.

[0023] According to embodiments of this disclosure, the epoxy resin is selected from one or more of bisphenol A type epoxy resin, bisphenol F type epoxy resin, vinyl epoxy resin, and hydantoin epoxy resin; the modified epoxy resin is selected from one or more of chloroprene-hydroxyethyl methacrylate copolymer modified epoxy resin, polyurethane modified epoxy resin, carboxyl-terminated propylene glycol polyether modified epoxy resin, nitrile rubber modified epoxy resin, silicone rubber modified epoxy resin, polybutadiene modified epoxy resin, polypropylene glycol diglycidyl ether modified epoxy resin, and polysulfide rubber toughened modified epoxy resin.

[0024] In the embodiments of this disclosure, the epoxy resin has a certain rigidity, which can improve the hardness of the coating. The modified epoxy resin has a certain wear resistance and toughness, which can make the prepared coating tough and wear-resistant, so that the coating can avoid wear from gas corrosion and cavitation corrosion during use and extend its service life.

[0025] According to embodiments of this disclosure, the polysiloxane containing active end groups includes polysiloxanes containing terminal hydroxyl, terminal amino, and terminal vinyl groups, such as those selected from one or more of the following: terminal hydroxyl polydimethylsiloxane, terminal hydroxyl polymethylphenylsiloxane, terminal hydroxyl polydiphenylsiloxane, terminal hydroxyl fluorinated polysiloxane, terminal amino polydimethylsiloxane, terminal vinyl polydimethylsiloxane, hydrogen-containing polysiloxane, and amino silicone oil. The viscosity of the polysiloxane containing active end groups is 50-20000 cps. The active end groups in the polysiloxane containing active end groups can react with silane coupling agents, and can also undergo a curing reaction with epoxy resin in the presence of a small amount of curing agent to form a preliminary mixture.

[0026] According to embodiments of this disclosure, the functional filler is selected from polytetrafluoroethylene, acrylonitrile-butadiene-styrene copolymer, polyvinyl chloride, chlorinated polyether, acrylic resin, polycarbonate, fumed silica, carbon black, nano zinc oxide, nano titanium dioxide, mica, kaolin, barium sulfate, aluminum hydroxide, silicon carbide, alumina, silicon carbide, ceramics, silicon micro powder, glass powder, calcium carbonate, antifouling agent, fatty nitrile, polydimethylsiloxane, and polymethylphenylsiloxane.

[0027] In the embodiments of this disclosure, different types of functional fillers can be selected to give the coating different properties. For example, selecting hydrophobic silica can further increase the hydrophobicity of the coating and can be applied to ice-repellent coatings; selecting fillers such as antifouling agents can give the coating certain marine antifouling properties and can be applied to marine antifouling coatings.

[0028] According to embodiments of this disclosure, the above-described hard film polysiloxane coating can be used in ice-repellent coatings, marine antifouling coatings, building protective coatings, and anti-corrosion coatings.

[0029] According to the embodiments of this disclosure, the catalyst is selected from one or more of platinum catalysts, dibutyltin dilaurate, stannous octoate, bismuth laurate, titanate, and tetramethylammonium hydroxide. The curing agent is selected from one or more of cyclohexanediamine, diethylenetriamine, triethylenetetramine, polyethylenepolyamine, 3-diethylaminopropylamine, polyamide resin, phenolic amine, cashew nut shell powder, salicylic acid, and benzyl alcohol.

[0030] According to embodiments of this disclosure, the first silane coupling agent and the second silane coupling agent are each independently selected from one or more of γ-aminopropyltriethoxysilane, γ-(2,3-epoxypropoxy)propyltrimethoxysilane, bis(triethoxysilylpropyl)amino, β-(3,4-epoxycyclohexyl)ethyltrimethoxysilane, γ-methacryloyloxypropyltrimethoxysilane, 3-mercaptopropyltrimethoxysilane, and n-β-(aminoethyl)-γ-aminopropyltrimethoxysilane. The types and amounts of the first silane coupling agent and the second silane coupling agent may be the same or different.

[0031] According to embodiments of this disclosure, a method for preparing a hard-film polysiloxane coating is also provided, comprising: reacting an epoxy resin and / or a modified epoxy resin with a first silane coupling agent to form a silane coupling agent-modified epoxy resin; mixing the silane coupling agent-modified epoxy resin with a polysiloxane containing active end groups, such that the silane coupling agent in the silane coupling agent-modified epoxy resin reacts with the polysiloxane containing active end groups, and then adding a curing agent and stirring to form a preliminary mixture; adding a functional filler to the preliminary mixture and stirring to form a composite adhesive; adding a second silane coupling agent and a catalyst to the composite adhesive and mixing and stirring to obtain a coating; wherein the first silane coupling agent and the second silane coupling agent are of the same type and the amount used are different.

[0032] In the embodiments of this disclosure, epoxy resin and / or modified epoxy resin are reacted with a first silane coupling agent, causing the epoxy groups in the epoxy resin and / or modified epoxy resin to react with the groups (such as amino groups) in the first silane coupling agent to form a silane coupling agent-modified epoxy resin. Subsequently, the silane coupling agent-modified epoxy resin and a polysiloxane containing active end groups are mixed, causing the silane coupling agent in the silane coupling agent-modified epoxy resin to hydrolyze and react with the polysiloxane containing active end groups. Then, a curing agent is added and stirred, causing a portion of the added curing agent to react with the epoxy resin in the silane coupling agent-modified epoxy resin to form a preliminary mixture. Then, a functional filler is added to the preliminary mixture and stirred to form a composite adhesive, giving the composite adhesive certain functions. Finally, a second silane coupling agent and a catalyst are added to the composite adhesive, allowing the second silane coupling agent to react with the epoxy resin in the composite adhesive. Simultaneously, the siloxane coupled to the epoxy resin by the silane coupling agent hydrolyzes under the promotion of the catalyst, forming a high-density cross-linked network, thus obtaining a coating with a multi-layered cross-linked network structure. In this embodiment, the first silane coupling agent is used to couple the epoxy resin or modified epoxy resin with a polysiloxane containing active end groups, forming a silane coupling agent-modified epoxy resin prepolymer, while appropriately increasing the system viscosity. The second silane coupling agent is used for curing the composite adhesive, further increasing the degree of cross-linking, thereby obtaining a hard-film polysiloxane coating with a multi-layered cross-linked network structure and functional fillers filling the multi-layered cross-linked network structure. Furthermore, the preparation process of the coating disclosed herein is relatively simple, low-cost, and easy to streamline into an operational line.

[0033] According to embodiments of this disclosure, the stirring speed during the preparation of hard film polysiloxane coatings is 2000-5000 r / min, the stirring time is 0.5-2 h, and the reaction conditions are room temperature.

[0034] To make the technical solutions and advantages of this disclosure clearer, the technical solutions of this disclosure will be further described below with reference to specific embodiments. It should be noted that the described embodiments are only some embodiments of this disclosure, and not all embodiments.

[0035] Example

[0036] Example 1

[0037] A hard-film polysiloxane coating for de-icing is prepared from the following components in parts by weight: 18 parts of bisphenol A epoxy resin, 12 parts of bisphenol F epoxy resin, 30 parts of hydroxyl-terminated polydimethylsiloxane, 5 parts of hydroxyl-terminated fluorinated polysiloxane, 1 part of hydrophobically modified fumed silica, 5 parts of diethylenetriamine, 15 parts of bis(triethoxysilylpropyl)amine, 10 parts of γ-aminopropyltriethoxysilane, and 0.2 parts of dibutyltin dilaurate.

[0038] The above-mentioned hard film polysiloxane coating for ice removal is prepared by the following steps:

[0039] (1) Add 18 parts of bisphenol A type epoxy resin, 12 parts of bisphenol F type epoxy resin and 5 parts of γ-aminopropyltriethoxysilane (first silane coupling agent) to a sand mill and mix thoroughly to make the reaction of bisphenol A type epoxy resin, bisphenol F type epoxy resin and γ-aminopropyltriethoxysilane uniform, and obtain silane coupling agent modified epoxy resin.

[0040] (2) Silane coupling agent modified epoxy resin, 30 parts of hydroxyl-terminated polydimethylsiloxane (polysiloxane with active end groups) and 5 parts of hydroxyl-terminated fluorinated polysiloxane (polysiloxane with active end groups) are put into a sand mill and stirred evenly. Then, 5 parts of diethylenetriamine (curing agent) are added and mixed thoroughly. After stirring evenly, a preliminary mixture is obtained.

[0041] (3) Add the initial mixed adhesive and 1 part of hydrophobic modified fumed silica (functional filler) into the sand mill, stir evenly, and a composite adhesive is formed.

[0042] (4) Add 5 parts of γ-aminopropyltriethoxysilane (second silane coupling agent), 15 parts of bis(triethoxysilylpropyl)amine (second silane coupling agent), and 0.2 parts of dibutyltin dilaurate (catalyst) to the composite adhesive, mix thoroughly and stir evenly, and then filter to obtain a hard film polysiloxane coating for ice removal.

[0043] Example 2

[0044] A hard-film polysiloxane coating for marine antifouling is prepared from the following components in parts by weight: 10 parts bisphenol F type epoxy resin, 35 parts polyurethane modified epoxy resin, 10 parts hydroxyl-terminated polydimethylsiloxane, 5 parts hydroxyl-terminated polymethylphenylsiloxane, 5 parts polydimethylsiloxane, 5 parts amino silicone oil, 5 parts polyamide resin, 1 part antifouling agent, 15 parts bis(triethoxysilylpropyl)amino, 10 parts total of γ-aminopropyltriethoxysilane, and 0.2 parts dibutyltin dilaurate.

[0045] The above-mentioned hard film polysiloxane coating for marine antifouling is prepared by the following steps:

[0046] (1) Add 10 parts of bisphenol F type epoxy resin, 35 parts of polyurethane modified epoxy resin and 5 parts of γ-aminopropyltriethoxysilane (first silane coupling agent) to a sand mill and mix thoroughly to make the polyurethane modified epoxy resin and γ-aminopropyltriethoxysilane (first silane coupling agent) react evenly to obtain silane coupling agent modified epoxy resin.

[0047] (2) Silane coupling agent modified epoxy resin, 10 parts of hydroxyl-terminated polydimethylsiloxane, 5 parts of hydroxyl-terminated polymethylphenylsiloxane (polysiloxane with active end groups), 5 parts of polydimethylsiloxane (filler) and 5 parts of amino silicone oil (polysiloxane with active end groups) are put into a sand mill and stirred evenly. Then, 5 parts of polyamide resin (curing agent) are added and mixed evenly. After filtration, the initial mixture is obtained.

[0048] (3) Add the initial mixed adhesive and 1 part of antifouling agent (SEA-NINE 211, functional filler) to the sand mill, stir evenly, and a composite adhesive is formed;

[0049] (4) Add 5 parts of γ-aminopropyltriethoxysilane (second silane coupling agent), 15 parts of bis(triethoxysilylpropyl)amine and 0.2 parts of dibutyltin dilaurate (catalyst) to the composite adhesive and stir thoroughly to obtain a hard film polysiloxane coating for marine antifouling.

[0050] Example 3

[0051] A hard-film polysiloxane coating for building protection is prepared from the following components in parts by weight: 10 parts of bisphenol A type epoxy resin, 30 parts of polybutadiene-modified epoxy resin, 20 parts of hydroxyl-terminated polydimethylsiloxane, 5 parts of amino silicone oil, 10 parts of polyamide resin, 0.5 parts of hydrophobically modified fumed silica, 15 parts of bis(triethoxysilylpropyl)amino, 10 parts of γ-aminopropyltriethoxysilane, and 0.05 parts of dibutyltin dilaurate.

[0052] The above-mentioned rigid film polysiloxane coating for building protection is prepared by the following steps:

[0053] (1) Add 10 parts of bisphenol A type epoxy resin, 30 parts of polybutadiene modified epoxy resin and 5 parts of γ-aminopropyltriethoxysilane (first silane coupling agent) to a sand mill and mix thoroughly to make the polybutadiene modified epoxy resin and γ-aminopropyltriethoxysilane (first silane coupling agent) react evenly to obtain silane coupling agent modified epoxy resin.

[0054] (2) Silane coupling agent modified epoxy resin, 20 parts of hydroxyl-terminated polydimethylsiloxane (polysiloxane with active end groups) and 5 parts of amino silicone oil (polysiloxane with active end groups) are put into a sand mill and stirred evenly. Then, 10 parts of polyamide resin (curing agent) are added and stirred evenly. After filtration, the initial mixture is obtained.

[0055] (3) Add the initial mixed adhesive and 0.5 parts of hydrophobic modified fumed silica (functional filler) into the sand mill, stir evenly, and a composite adhesive is formed;

[0056] (4) Add 5 parts of γ-aminopropyltriethoxysilane (second silane coupling agent), 15 parts of bis(triethoxysilylpropyl)amine (second silane coupling agent) and 0.05 parts of dibutyltin dilaurate (catalyst) to the composite adhesive, stir and mix thoroughly, and then filter to obtain a hard film polysiloxane coating for building protection.

[0057] Example 4

[0058] A high-temperature resistant hard-film polysiloxane coating is prepared from the following components in parts by weight: 30 parts of silicone rubber modified epoxy resin, 30 parts of hydroxyl-terminated polymethylphenylsiloxane, 5 parts of amino silicone oil, 5 parts of polyamide resin, 5 parts of silicon carbide, 15 parts of bis(triethoxysilylpropyl)amino, 10 parts of γ-aminopropyltriethoxysilane, and 0.2 parts of dibutyltin dilaurate.

[0059] The above-mentioned high-temperature resistant hard-film polysiloxane coating is prepared by the following steps:

[0060] (1) Add 30 parts of silicone rubber modified epoxy resin and 5 parts of γ-aminopropyltriethoxysilane to a sand mill and mix thoroughly to make the silicone rubber modified epoxy resin and γ-aminopropyltriethoxysilane (first silane coupling agent) react evenly to obtain silane coupling agent modified epoxy resin.

[0061] (2) Put the epoxy resin modified with silane coupling agent, 30 parts of hydroxyl-terminated polymethylphenylsiloxane, and 5 parts of amino silicone oil (polysiloxane with active end groups) into a sand mill and stir evenly. Then add 5 parts of polyamide resin (curing agent) and mix thoroughly. After stirring evenly, the initial mixture is obtained.

[0062] (3) Add the initial mixed adhesive and 5 parts of silicon carbide (filler) to the sand mill, stir evenly, and a composite adhesive is formed;

[0063] (4) Add 5 parts of γ-aminopropyltriethoxysilane (second silane coupling agent), 15 parts of bis(triethoxysilylpropyl)amine and 0.2 parts of dibutyltin dilaurate (catalyst) to the composite adhesive, stir and mix thoroughly, and then filter to obtain a high-temperature resistant hard film polysiloxane coating.

[0064] The hard film polysiloxane coating in Example 4 was tested for high temperature resistance and it could withstand a high temperature of 500°C.

[0065] Example 5

[0066] A polysiloxane coating for corrosion protection is prepared from the following components in parts by weight: 50 parts of bisphenol F type epoxy resin, 10 parts of hydroxyl-terminated polydimethylsiloxane, 5 parts of amino silicone oil, 20 parts of polyamide resin, 0.5 parts of fumed silica, 5 parts of nano zinc oxide, 10 parts of bis(triethoxysilylpropyl)amine, 5 parts of γ-aminopropyltriethoxysilane, and 0.1 parts of dibutyltin dilaurate.

[0067] The above-mentioned hard-film polysiloxane coating for corrosion protection is prepared through the following steps:

[0068] (1) Add 50 parts of bisphenol F type epoxy resin and 5 parts of γ-aminopropyltriethoxysilane (first silane coupling agent) to a sand mill and mix thoroughly to make the reaction of bisphenol F type epoxy resin and γ-aminopropyltriethoxysilane uniform, and obtain epoxy resin modified by silane coupling agent.

[0069] (2) Silane coupling agent modified epoxy resin, 10 parts of hydroxyl-terminated polydimethylsiloxane (polysiloxane with active end groups) and 5 parts of amino silicone oil (polysiloxane with active end groups) are put into a sand mill and stirred evenly. Then, 20 parts of polyamide resin (curing agent) are added and mixed thoroughly. After stirring evenly, the initial mixture is obtained.

[0070] (3) Add the initial mixed adhesive, 0.5 parts of hydrophobic modified fumed silica (functional filler) and 5 parts of nano zinc oxide into a sand mill, stir evenly, and a composite adhesive is formed.

[0071] (4) Add 10 parts of bis(triethoxysilylpropyl)amine (second silane coupling agent) and 0.1 parts of dibutyltin dilaurate (catalyst) to the composite adhesive, stir and mix thoroughly, and then filter to obtain a hard film polysiloxane coating for corrosion protection.

[0072] Comparative Example 1

[0073] A polysiloxane coating for de-icing is prepared from the following components in parts by weight: 60 parts of hydroxyl-terminated polydimethylsiloxane, 15 parts of hydroxyl-terminated fluorinated polysiloxane, 1 part of hydrophobically modified fumed silica, 10 parts of vinyltriacetoxysilane, 15 parts of bis(triethoxysilylpropyl)amino, 10 parts of γ-aminopropyltriethoxysilane, and 0.2 parts of dibutyltin dilaurate.

[0074] The above-mentioned polysiloxane coatings for ice-repellent applications are prepared through the following steps:

[0075] (1) Put 60 parts of hydroxyl-terminated polydimethylsiloxane and 15 parts of hydroxyl-terminated fluorinated polysiloxane into a sand mill and stir. Then add 1 part of hydrophobic modified fumed silica (functional filler), mix thoroughly, and stir to obtain a preliminary mixture.

[0076] (2) Add 10 parts of vinyltriacetoxysilane (containing active end-group polysiloxane), 15 parts of bis(triethoxysilylpropyl)amine, 10 parts of γ-aminopropyltriethoxysilane (coupling agent) and dibutyltin dilaurate (catalyst) to the initial mixed adhesive, mix and stir thoroughly, and filter to obtain polysiloxane coating for ice removal.

[0077] Comparative Example 2

[0078] A polysiloxane coating for marine antifouling is prepared from the following components in parts by weight: 50 parts of hydroxyl-terminated vinyl polysiloxane, 10 parts of hydroxyl-terminated polymethylphenylsiloxane, 5 parts of polydimethylsiloxane, 1 part of antifouling agent, 10 parts of vinyltriacetoxysilane, 15 parts of bis(triethoxysilylpropyl)amino, 10 parts of γ-aminopropyltriethoxysilane, 0.2 parts of dibutyltin dilaurate, and 0.01 parts of platinum catalyst.

[0079] The above-mentioned polysiloxane coating for marine antifouling is prepared through the following steps:

[0080] (1) Put 50 parts of hydroxyl-terminated vinyl polysiloxane, 10 parts of hydroxyl-terminated polymethylphenyl siloxane and 5 parts of polydimethyl siloxane into a sand mill, stir, then add 1 part of antifouling agent, mix thoroughly to obtain a preliminary mixture.

[0081] (2) Add 10 parts of vinyltriacetoxysilane, 15 parts of bis(triethoxysilylpropyl)amine, 10 parts of γ-aminopropyltriethoxysilane, 0.2 parts of dibutyltin dilaurate and 0.01 parts of platinum catalyst to the initial mixed adhesive, mix and stir thoroughly, and filter to obtain a polysiloxane coating for marine antifouling.

[0082] The coatings in Examples 1-5 and Comparative Examples 1-2 were subjected to hardness (GB / T6739-2006), paint adhesion (GB / T5210-2006), and impact resistance (GB / T1732-2020) tests. The specific test results are shown in Table 1.

[0083] Table 1

[0084] Example 1 5H 3.7MPa <![CDATA[50·kg cm -2 ]]> Example 2 5H 3.5MPa <![CDATA[50·kg cm -2 ]]> Example 3 7H 4.9MPa <![CDATA[50·kg cm -2 ]]> Example 4 7H 3.6MPa <![CDATA[50·kg cm -2 ]]> Example 5 7H 4.8MPa <![CDATA[50·kg cm -2 ]]> Comparative Example 1 H 1.4MPa <![CDATA[50·kg cm -2 ]]> Comparative Example 2 2B 1.2MPa <![CDATA[50·kg cm -2 ]]>

[0085] Furthermore, the adhesion performance of the hard film polysiloxane coating to the substrate was tested at different temperatures in Example 1, and the specific test results are shown in Table 2.

[0086] Table 2

[0087] Example 1 25℃ 3.7MPa Example 1 -50℃ 3.5MPa Example 1 100℃ 3.2MPa

[0088] As can be seen from Tables 1 and 2, the coating provided in this disclosure has excellent hardness and paint adhesion performance. The maximum hardness of the paint film is 7H and the maximum paint adhesion is 4.9MPa. Example 1 can maintain adhesion in a temperature range of -50℃ to 100℃ (paint adhesion).

[0089] The specific embodiments described above further illustrate the purpose, technical solutions, and beneficial effects of this disclosure. It should be understood that the above descriptions are merely specific embodiments of this disclosure and are not intended to limit this disclosure. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this disclosure should be included within the protection scope of this disclosure.

Claims

1. A method for preparing a hard-film polysiloxane coating, comprising: Epoxy resin, modified epoxy resin and first silane coupling agent are reacted to form silane coupling agent modified epoxy resin. The epoxy resin modified with the silane coupling agent is mixed with a polysiloxane containing active end groups, so that the silane coupling agent in the epoxy resin modified with the silane coupling agent reacts with the polysiloxane containing active end groups. Then, a curing agent is added and stirred to form a preliminary mixture. Functional fillers are added to the initial mixture and stirred to form a composite adhesive; A second silane coupling agent and a catalyst are added to the composite adhesive and mixed and stirred to obtain the coating. The coating film has a hardness of 7H and the coating surface adhesion is 4.9MPa. Wherein, the first silane coupling agent and the second silane coupling agent are of the same type and different amounts, and the first silane coupling agent and the second silane coupling agent are each independently selected from at least one of γ-aminopropyltriethoxysilane, bis(triethoxysilylpropyl)amine, and N-β-(aminoethyl)-γ-aminopropyltrimethoxysilane. The modified epoxy resin is selected from at least one of chloroprene-hydroxyethyl methacrylate copolymer modified epoxy resin and polybutadiene modified epoxy resin; The polysiloxane containing active end groups is selected from at least one of hydroxyl-terminated polydimethylsiloxane, hydroxyl-terminated polymethylphenylsiloxane, hydroxyl-terminated polydiphenylsiloxane, hydroxyl-terminated fluorinated polysiloxane, and amino-terminated polydimethylsiloxane.

2. The method of claim 1, wherein, The weight ratio of the epoxy resin and modified epoxy resin to the polysiloxane containing active end groups is between 5:1 and 1:

2.

3. The method of claim 1 or 2, wherein, The coating is prepared from the following components: 20-150 parts of epoxy resin and modified epoxy resin; 10-80 parts of polysiloxane containing active end groups; Catalyst 0.01-1 part; Functional fillers, 0.1-20 parts; 5-40 parts of curing agent; 5-30 parts of the first silane coupling agent and the second silane coupling agent.

4. The method of claim 3, wherein, The epoxy resin is selected from at least one of the following: Bisphenol A type epoxy resin, bisphenol F type epoxy resin, vinyl epoxy resin, hydantoin epoxy resin.

5. The method of claim 3, wherein, The functional filler is selected from at least one of the following: Polytetrafluoroethylene, acrylonitrile-butadiene-styrene copolymer, polyvinyl chloride, chlorinated polyether, acrylic resin, polycarbonate, fumed silica, carbon black, nano zinc oxide, nano titanium dioxide, mica, kaolin, barium sulfate, aluminum hydroxide, alumina, silicon carbide, silicon micro powder, glass powder, calcium carbonate, antifouling agent, polydimethylsiloxane, polymethylphenylsiloxane.

6. The method of claim 3, wherein, The catalyst is selected from at least one of the following: Dibutyltin dilaurate, stannous octanoate, bismuth laurate, tetramethylammonium hydroxide; The curing agent is selected from at least one of the following: Cyclohexanediamine, polyethylene polyamine, 3-diethylaminopropylamine, polyamide resin, phenolic amine.

7. The method of claim 6, wherein, The curing agent is selected from diethylenetriamine or triethylenetetramine.

8. The method of claim 1, wherein, The stirring speed is 2000-5000 r / min, and the stirring time is 0.5-2h.

9. A hard-film polysiloxane coating prepared by any one of claims 1-8, the coating having a multi-linked network structure formed by an epoxy resin and a modified epoxy resin and a polysiloxane containing active end groups, and a functional filler filled in the multi-linked network structure, wherein the epoxy resin and the modified epoxy resin are coupled together with the polysiloxane containing active end groups by a coupling agent. wherein The modified epoxy resin is selected from at least one of the following: Chloroprene-hydroxyethyl methacrylate copolymer modified epoxy resin, polybutadiene modified epoxy resin; The coupling agent includes a first silane coupling agent and a second silane coupling agent.

10. The application of the hard film polysiloxane coating as described in claim 9 as an ice-repellent coating, marine antifouling coating, building protective coating, and anti-corrosion coating.