Normal-temperature curing environment-friendly silicon-based nano coating, preparation method and application thereof

Abstract

The present application relates to a kind of normal temperature curing environment-friendly type silicon-based nanometer coating, its preparation method and application. According to the silicon-based nanometer coating prepared according to the technical scheme of the present application, the heat insulation, heat resistance and electric field breakdown resistance performance are improved, and the controllable wettability control range is also provided, which can be effectively applied to building outer surface, detector inner and outer surface and automobile dome outer surface etc. as coating.

Description

Technical Field

[0001] This invention relates to the field of chemical synthesis, and more specifically, to a room-temperature curing environmentally friendly silicon-based coating, its preparation method, and its application. Background Technology

[0002] Organosilicon-inorganic silicon coatings, due to their organic-inorganic hybrid structure, can be developed into materials and coatings with excellent thermal insulation, heat insulation, and electrical insulation properties. Furthermore, in general civil and industrial applications, surfaces with specific wetting properties are frequently required, such as pipeline flow control and monitoring, high-temperature and high-pressure monitoring, smart building facades, and automotive exteriors. In complex operating conditions, organosilicon-inorganic composite coatings often require applications with combined thermal, electrical, and surface wetting properties. Although some heat-resistant insulation layer technologies exist, they generally struggle to simultaneously achieve or maintain a well-controlled wetting surface, which limits the application range and technical performance improvement of silicon-based coatings.

[0003] For example, Chinese patent publication CN119569418A discloses a method for manufacturing a low thermal conductivity, high-temperature resistant silica aerogel insulation layer. However, this technology does not disclose or achieve good electrical breakdown resistance and insulation properties, nor does it consider the control of the wetting properties of the surface to which the layer is applied.

[0004] Therefore, this field still needs a room temperature curing, highly insulating and heat-resistant coating and corresponding coating layer. Through appropriate molecular structure design and filler component control, a more regular coating stacking structure can be achieved in order to meet the application requirements of heat resistance, insulation and wettability. Summary of the Invention

[0005] The purpose of this invention is to address one or more deficiencies in the prior art, and to provide a silicon-based coating, as well as an environmentally friendly silicon-based nano-coating that can be cured at room temperature, its preparation method, and its application, thereby improving the application requirements for heat resistance, insulation, and wettability of the surface, while also facilitating user operation and control of the surface wetting state during adjustment.

[0006] In a first aspect of the invention, a room-temperature curable silicon-based nano-coating is provided, wherein the silicon-based nano-coating comprises, by weight, the following raw materials:

[0007] Silicone oil-based composition: 150 to 200 parts by weight;

[0008] Hydrophilic-hydrophobic control matrix: 15 to 35 parts by weight;

[0009] Matrix reinforcement fiber: 5 to 30 parts by weight;

[0010] Aniline-formaldehyde resin: 10 to 30 parts by weight;

[0011] Diluent: 10 to 30 parts by weight; and

[0012] The silicone oil base composition comprises an epoxy-terminated silicone oil with a weight-average molecular weight of 10,000 to 12,000, a bifunctional phenyl vinyl silicone oil with a weight-average molecular weight of 600 to 800, a bifunctional phenyl hydrogen-containing silicone oil with a weight-average molecular weight of 600 to 900, and an adhesion-enhancing component; and

[0013] The hydrophilicity-hydrophobicity modulating matrix includes two or more types of silica microparticles with different particle size distributions.

[0014] In a further optional embodiment, the hydrophilicity / hydrophobicity controlled matrix comprises three types of silica microparticles with different particle size distributions, and...

[0015] The first silica particles are nano-silica with an average particle size (D50) of 8 to 15 nm, accounting for 10 wt% to 20 wt% of the total silica particles.

[0016] The second silica particles are nano-silica with an average particle size (D50) of 50 to 75 nm, accounting for 30 wt% to 45 wt% of the total silica particles.

[0017] The third type of silica particles consists of silica particles with an average particle size (D50) of 1 to 3 micrometers, accounting for 40 wt% to 50 wt% of the total silica particle mass; and

[0018] The mass ratio of the silicone oil base composition to the hydrophilic-hydrophobic modulating matrix is ​​between 10:(1-2).

[0019] In a further optional embodiment, the silicone oil base composition comprises, based on a total weight of 100 wt% of the silicone oil base composition:

[0020] 25 wt% to 30 wt% of terminal epoxy-based silicone oils with a weight average molecular weight of 10,000 to 12,000;

[0021] 55 wt% to 60 wt% of bifunctional phenyl vinyl silicone oil with a weight average molecular weight of 600 to 800;

[0022] 5 wt% to 10 wt% of bifunctional phenyl hydrogen-containing silicone oil with a weight average molecular weight of 600-900;

[0023] 0.5 wt% to 1 wt% of adhesion-enhancing components;

[0024] 0.1 wt% to 1 wt% of control agent; and

[0025] Anhydrous ethanol as a solvent.

[0026] In a further optional embodiment, the room-temperature curing silicon-based nano-coating also satisfies one or more of the following conditions:

[0027] The matrix reinforcing fiber is a quartz fiber with an average length of 20 to 40 micrometers and an aspect ratio greater than 10:1;

[0028] The diluent is ethyl acetate;

[0029] The room-temperature curable silicon-based nano-coating contains tetrabutyltitanium as an auxiliary catalyst; and

[0030] The hydrophilicity-hydrophobicity controlled matrix is ​​prepared by mixing and stirring the silica microparticles with tetraethyl orthosilicate and heptadecafluorodecyltrimethoxysilane.

[0031] In a further optional embodiment, the room-temperature curable silicon-based nano-coating is prepared by a method comprising the following steps:

[0032] Step 1): Prepare the raw material components of the silicone oil base composition, and stir each component evenly in a mixer to obtain the silicone oil base composition;

[0033] Step 2): Prepare 5 to 10 parts by weight of deionized water, add the measured silica particles of the hydrophilicity-hydrophobicity control matrix into the mixture and stir; then add 5 to 10 wt% tetraethyl orthosilicate and 1 to 5 wt% heptadecafluorodecyltrimethoxysilane, accounting for 5 wt% to 10 wt% of the total solid content in the above hydrophilicity-hydrophobicity control matrix, and stir thoroughly until the mixture is free of stratification; obtain the hydrophilicity-hydrophobicity control matrix;

[0034] Step 3): Mix the above hydrophilic and hydrophobic modulating matrix with the silicone oil base composition, add the corresponding weight parts of reinforcing fiber, and stir to obtain the first intermediate;

[0035] Step 4): Add the appropriate proportion of aniline-formaldehyde resin to the first intermediate, and mix to obtain the second intermediate;

[0036] Step 5): Mix the second intermediate with 3-5 parts by weight of auxiliary catalyst, add the corresponding parts by weight of diluent, stir and mix to obtain a room temperature curable silicon-based nano-coating.

[0037] A second aspect of the present invention provides a method for preparing an environmentally friendly silicon-based nano-coating that cures at room temperature.

[0038] The room-temperature curable silicon-based nano-coating described in any of the above-mentioned methods is applied to the surface of a device or substrate and cured at room temperature for 96 to 120 hours to obtain the silicon-based nano-coating.

[0039] In a further optional embodiment, in the method for preparing the room-temperature curing environmentally friendly silicon-based nano-coating, the thickness of the silicon-based nano-coating is between 500 micrometers and 5 millimeters.

[0040] According to a third aspect of the present invention, an application of a room-temperature curing environmentally friendly silicon-based nano-coating is provided, wherein the coating prepared by the method of preparing the room-temperature curing environmentally friendly silicon-based nano-coating is applied to the pipe surface of a flow control device, the outer surface of a building, or the outer surface of a new energy vehicle.

[0041] According to the coating of the present invention, preferably, after the coating is applied to the corresponding surface, the wetting angle between the coating surface and the water droplet varies between 10° and 170°.

[0042] The room-temperature curing environmentally friendly silicon-based nanocoating prepared according to the embodiments of the present invention exhibits improved thermal conductivity, breakdown field strength, and heat resistance in performance testing and applications. Furthermore, the environmentally friendly silicon-based nanocoating of the present invention also allows for the control of surface wetting characteristics within a reasonable range according to the application scenario.

[0043] The technical solutions and advantages of the present invention will be explained and described in more detail below with reference to specific embodiments. It should be understood that the content presented in the specification and specific embodiments is only for the purpose of more clearly illustrating the technical solutions and advantages of the present invention, and does not constitute a limitation on the scope of protection of the present invention. Those skilled in the art can obtain various reasonable modifications based on the content disclosed in the specification, and as long as they do not depart from the spirit of the present invention, all modified technical solutions should be understood to be included within the scope of protection of the present invention. Attached Figure Description

[0044] In this specification, additional drawings are used to provide a further understanding of the technical solutions disclosed herein, and constitute a part of the specification. They are used together with the specific embodiments of this application to explain the technical solutions disclosed herein, and do not constitute a limitation on the technical solutions disclosed herein.

[0045] Figure 1 This is a schematic photograph of a flow control chip using the environmentally friendly silicon-based nano-coating that can be cured at room temperature according to the present invention.

[0046] Figure 2 This is a schematic diagram of the device for controlling and adjusting the wettability of the room-temperature curing environmentally friendly silicon-based nano-coating of the present invention;

[0047] Figure 3 The image shows the water droplet wetting angle (hydrophilic control) of the room-temperature curing environmentally friendly silicon-based nano-coating manufactured according to Example 1 of the present invention during the wettability control process.

[0048] Figure 4 This is a photograph of the water droplet wetting angle (hydrophobicity control) of the room-temperature curing environmentally friendly silicon-based nano-coating manufactured according to Example 1 of the present invention.

[0049] Reference numerals in the accompanying drawings:

[0050] 101-DC power supply; 102-electrode plate; 103-substrate; 104-coating; 105-heating plate; Detailed Implementation

[0051] The invention is described in more detail below to aid in understanding it.

[0052] Before describing the specific implementation scheme, those skilled in the art can select appropriate raw materials based on the teachings and guidance of this disclosure, conduct relevant tests using relevant testing equipment, and obtain corresponding results. For raw materials for which no specific manufacturer or source is specified, those skilled in the art can select raw materials that meet the corresponding requirements as reaction starting materials based on the disclosure and needs of this specification. The reaction raw materials for the compounds in the process section are derived from the preliminary products or semi-finished products synthesized in the preceding steps of this invention, which is also understandable based on this disclosure.

[0053] Table 1 schematically describes the main raw materials used in this invention and their corresponding acquisition channels or origins. It should be noted that any raw materials not described in this invention are those that can be obtained by those skilled in the art based on ordinary technical knowledge and existing market products.

[0054] Table 1: Sources and Usage Instructions for Some Raw Materials

[0055]

[0056] Note 1: Some of the experiments in this invention also used the RH-NB-ES10K series of epoxy block polyether silicone oils provided by Ningbo Runhe High-Tech Materials Co., Ltd.

[0057] Note 2: In the inventor's series of experiments, BASF's Silicone 100 series products, etc., may also be used;

[0058] Note 3: Based on the experimental results tested by the inventors, Scotch-Weld from 3M is the preferred adhesive enhancement component. TM A series of products. However, the invention is not limited to this. In the inventors' series of experiments, Henkel's products could also be used. 770 TM Series, Dow Corning's Dow 1200 Primer, Huntsman Corporation 2021, and BASF. EP21LV series products, etc.

[0059] In the embodiments of the present invention, the particle size is expressed as the average particle size. In a preferred embodiment, the average particle size is expressed as D50 particle size, but the present invention is not limited thereto, and other parameters can also be used to indicate the average particle size (e.g., D90, D97, etc.).

[0060] In this experimental example, the heat resistance standards for the silicone coating can be performed according to the corresponding national, industry, or international standards. Non-limitingly, in more specific tests, thermal conductivity can be determined using ASTM D5470; voltage withstand tests can be performed using the IEC 60243 standard published by the International Electrotechnical Commission; and heat resistance characteristics can be tested using wind tunnel experiments (JGJ / T338-2014). For example, a simulated high-temperature airflow is used to apply a heat load to the coating, equivalent to 370 kW of heat energy passing through the coating and workpiece per square meter. This is a relatively high heat load designed to test the coating's performance under harsh thermal environments. Regarding the back surface parameters, under high-temperature heat loads, it is confirmed whether the coating can maintain a low back surface temperature in a high heat flux density environment, meeting practical application requirements.

[0061] It should be noted that percentages in the technical solutions, embodiments, and contents of this invention are generally described in detail. Unless otherwise specified, concentrations or percentages refer to mass percentages (wt%) or are described or calculated as parts by weight of each component in the same unit.

[0062] Example 1

[0063] This embodiment describes the formulation and preparation method of a typical room-temperature curing silicon-based nanocoating.

[0064] In the following formulation, unless otherwise specified, the quantity of each ingredient is described by its corresponding weight parts. Firstly, in summary, the silicon-based nanocoating of this embodiment mainly comprises the following components:

[0065] Silicone oil-based composition: 200 parts by weight;

[0066] Hydrophilicity / hydrophobicity control matrix: 20 parts by weight;

[0067] Matrix reinforcement fiber: 10 parts by weight;

[0068] Aniline-formaldehyde resin: 20 parts by weight;

[0069] Diluent: 15 parts by weight.

[0070] More specifically, in a typical embodiment of this invention, the components can be obtained by the following methods:

[0071] The silicone oil base composition comprises (by weight percentage): 25 wt% of terminal epoxy-based silicone oil with a molecular weight (weight average molecular weight, the same below) of 10,000 to 12,000; 60 wt% of bifunctional phenyl vinyl silicone oil with a molecular weight of 600 to 800; 10 wt% of bifunctional phenyl hydrogen-containing silicone oil with a molecular weight of 600-900; and 0.8 wt% of adhesion-enhancing component (Scotch-Weld). TM DP-8405NS, from 3M TM The composition consists of 0.3 wt% of a control agent (1-ethynylcyclohexanol) and the remainder of anhydrous ethanol as an auxiliary solvent; typically, the above components are thoroughly mixed in a high-speed mixer to obtain a silicone oil-based composition.

[0072] Hydrophilicity-Hypersistence Controlled Matrix: In this experimental example, the hydrophilicity-hydropersistence controlled matrix is ​​preferably a composition of silica (SiO2) particles in a certain mass ratio within a specific particle size range. In typical Example 1, based on 100 wt% of the hydrophilicity-hydropersistence controlled matrix, it contains 15 wt% nano-silica with an average particle size (D50) of 8-15 nm, 40 wt% nano-silica with an average particle size (D50) of 50-75 nm, and 45 wt% silica particles with an average particle size (D50) of 1 to 3 micrometers (μm). The coating component of the hydrophilicity-hydropersistence controlled matrix can be obtained using existing methods. Furthermore, those skilled in the art will understand that corresponding cavities or pores exist within the silica particles. In typical Example 1:

[0073] Take 5 parts by weight of deionized water, add the weighed hydrophilicity-hydrophobicity control matrix to the deionized water and stir thoroughly for 60 minutes at a speed of 150-200 rpm; then add 10 wt% tetraethyl orthosilicate and 5 wt% heptadecafluorodecyltrimethoxysilane, and stir thoroughly until the mixture is free of stratification (usually the stirring time needs to be greater than 24 hours and the stirring speed greater than 200 rpm); obtain the hydrophilicity-hydrophobicity control matrix component;

[0074] The silicone oil base composition was mixed with the prepared hydrophilic-hydrophobic control matrix according to the weight ratio, and matrix reinforcing fibers (quartz fibers with an average fiber length of 20-40 micrometers and an aspect ratio greater than 10:1) were added. After thorough stirring, the first intermediate was obtained.

[0075] Add an appropriate proportion of aniline-formaldehyde resin to the obtained first intermediate, and mix to obtain the second intermediate;

[0076] The second intermediate is combined with an auxiliary catalyst (tetrabutyltitanium, TBT, calculated as 3-5 parts by weight according to the weight percentages of the components of the silicon-based nanocoating; if the production cost allows, a platinum-based catalyst can also be used, wherein the platinum content of the catalyst can be 3000-5000 ppm), and a diluent (e.g., ethyl acetate in the example) is added. The mixture is then sprayed onto the surface of the device or substrate to be coated and cured at room temperature for 96 to 120 hours to achieve, for example, a coating of 500 micrometers to 6 millimeters. If required by the application, it can also be further cured under micro-heating conditions (e.g., at 40°C to 60°C for 24 to 48 hours).

[0077] Examples 2 to 4

[0078] Based on the detailed description of Embodiment 1 above, the following additional embodiments will be described. In Embodiments 2 to 4 (see the table below), parts similar to those in the embodiments will be omitted, and only differences in some components will be described.

[0079] Table 2: Examples 2 to 4

[0080]

[0081]

[0082]

[0083] Test case

[0084] The room-temperature curable heat-resistant silicone coating of this invention significantly achieves and improves heat resistance, heat resistance, and puncture resistance. This makes the coating particularly suitable for equipment or components operating under high-temperature and high-heat conditions. The main characteristics tested are shown in the table below (in the test examples, for ease of characterization, preparation, and comparison, a uniform coating thickness of 5 mm was used, and the coating was applied to a stainless steel plate for testing):

[0085] Table 3: Thermal insulation and heat resistance tests of the room-temperature curing silicon-based nano-coating of the present invention

[0086]

[0087] Application Example 1:

[0088] A typical example of the application of the room-temperature curable environmentally friendly silicon-based nanocoating of the present invention includes a flow control chip. A schematic diagram of a typical flow control chip can be shown as follows: Figure 1 As shown. In Figure 1 In this invention, the sidewalls of pipes through which fluids (including aqueous and oil phases) flow can be coated with the silicon-based nanocoating described in the embodiments of the invention. The applicable pipe sidewall diameters range from several hundred micrometers to several millimeters (e.g., pipe diameters from 800 μm to 10 mm). According to the processes and methods described below, the hydrophilic-hydrophobic convertibility of the inner or outer surface of the pipe coated with the said coating can be achieved, thereby enabling the guiding, separation, and mixing of liquids in different regions. For example, in areas where droplet coalescence is required, the coating remains hydrophobic to prevent liquid contact, while in channels where liquid flow is required, the coating exhibits hydrophilicity to promote flow. Because the coating of the present invention has improved heat resistance and puncture resistance, flow control chips with the coating applied can be applied to harsh and high-temperature chemical and physical analysis fields, such as high-temperature pressure sensing equipment, high-temperature biomedical and chemical analysis, etc.

[0089] It should be noted that the coating components in the embodiments of the present invention do not use highly toxic metal elements that damage the environment (such as Cr, Cd, Pb, etc.), and basically do not use organic chemical substances that volatilize toxic gases at high temperatures. Therefore, they can be classified as environmentally friendly coatings or coatings, and are suitable for most application fields that require high temperature resistance or harsh working conditions.

[0090] To more clearly describe the application process of the coating of the present invention and the hydrophilicity-hydrophobicity conversion process, the inventors will describe the hydrophilicity-hydrophobicity conversion process of the coating in the embodiments of the present invention using... Figure 2 A schematic diagram is shown. In Figure 2 The diagram schematically illustrates the application of coating 104 onto substrate 103 (the substrate may be a metal substrate, such as a stainless steel substrate) in an embodiment of the present invention (or a comparative example described below). Electrode sheets 102 are attached to both sides of the substrate 103 on which coating 104 is applied; a heating element 105 is attached to one side of the electrode sheet 102; and the entire device is externally connected to a DC power supply 101.

[0091] In actual operation, the conversion between hydrophilic and hydrophobic properties can be achieved through the following process.

[0092] Hydrophilic conversion: Turn on the power and inject charge into the applied coating through a DC power supply (DC voltage set to 360V) for 30 minutes to 10 hours; as the charging time increases, water droplets gradually become unable to slide off the coating, achieving a superhydrophilic state; during this period, a heater can also be used to moderately heat the coating at a low temperature (e.g., the heating temperature is controlled at 50-60℃).

[0093] Hydrophobic conversion: When a hydrophobic surface is required, turn off the power and use a heating device to heat the coating and substrate at a relatively high temperature (heating temperature controlled at, for example, 150°C to 160°C) to remove the charge in the coating. The heating time is 2 to 8 hours. After most of the net charge and polarity are removed, deionized water droplets are gradually able to slide off the surface of the coating and substrate, thus becoming superhydrophobic.

[0094] In short, the coating of the present invention applies a charge to the particles of the coating (especially silica microparticles of various particle sizes in the coating), making the coating more polar and enabling a hydrophilic transition to water droplets, while removing most of the charge in the coating by heating at high temperature, thus achieving a hydrophobic transition.

[0095] Taking Example 1 as an example, the inventors tested the hydrophilic and hydrophobic properties of the coating of the present invention using the above-described method and apparatus. The results are shown in [reference needed]. Figure 3 and Figure 4 .

[0096] Figure 3 The diagram schematically illustrates the gradual change in the contact angle between the coating of Example 1 of the present invention and a water droplet during a hydrophilic conversion test. Initially, the surface of the coating of Example 1 exhibits a certain degree of hydrophobicity (approximately 105°). After the above-described energizing process continues for 2 hours, the contact angle (CA) changes to approximately 75°. After 4 hours of energizing, the contact angle becomes approximately 14°. During the test, the temperature of the substrate and the coating is controlled at approximately 40°C by a heating device.

[0097] It is worth mentioning that the inventors discovered that when the contact angle becomes approximately 14-15°, further increasing the energizing time (e.g., up to 8 hours or longer) will not decrease the contact angle further, which is exactly what the inventors expected and designed. In fact, in application examples (such as fluid control devices), it is undesirable for the channel or coating to become completely hydrophilic or hydrophobic, because, for example, a completely hydrophilic state will cause the flow resistance of water droplets in the flow channel to increase undesirably, while a completely hydrophobic state will cause the fluid flow rate to be too fast, leading to stalling and loss of control.

[0098] Figure 4 The hydrophobic conversion process was described. With charge transport disabled, the substrate and coating were heated at 150°C using a heater. After 3 hours of heating (measured after being allowed to cool to room temperature, the same applies below), the contact angle reached 152°, and after 6 hours of heating, the contact angle reached approximately 165°. Beyond this point, even with further extension of the heating time, the contact angle between the coating and the water droplet no longer changed significantly.

[0099] Similarly, as mentioned above, the inventors actually need the hydrophobic angle of the coating to not be completely hydrophobic (close to 180°), preferably less than 170°, in order to achieve better controllability at the application end.

[0100] In an embodiment of the invention, the contact angle between the coating and the water droplet can vary in the range of approximately 10° to 170°, preferably controlled to vary in the range of approximately 15° to 165°.

[0101] Application Example 2

[0102] The coating of this invention can also be applied to the roofs of new energy vehicles. In recent years, the automotive industry has seen a trend towards using large-area domes (such as glass, metal, or other materials) in the manufacturing process of many new energy vehicles. In hot weather, these domes are exposed to prolonged sunlight, leading to a decline in user experience. However, the coating of this invention can be applied to the roof of new energy vehicles. On the one hand, the coating can withstand high temperatures and remain crack-free and non-peeling; on the other hand, its excellent temperature insulation effect enhances the passenger experience. Of course, when the hydrophilic and hydrophobic conversion of the roof coating is required, the temperature changes and voltage applied must comply with the safety standards for passenger vehicles. Appropriate hydrophilic-hydrophobic conversion can also give the roof a good self-cleaning effect. Correspondingly, it can also be used on the surfaces of smart buildings, which have emerged in recent years.

[0103] Application Example 3

[0104] The coating of this invention can also be applied to other fields, such as the exterior surfaces of high-end buildings, and the surfaces of roads and concrete requiring special properties. It can also increase temperature resistance and maintain controllable surface wetting properties.

[0105] Comparative Example

[0106] This section describes comparative experiments corresponding to the examples. For ease of description, the following will omit the parts that are the same as those in the examples, and focus on describing the components and / or process parameters that are different from those in the examples.

[0107] Comparative Example 1

[0108] In Comparative Example 1, the coating composition and preparation process were essentially the same as in Example 1. The difference was that in Comparative Example 1, based on a 100 wt% hydrophilicity-hydrophobicity controlled matrix, the three different silica particles of the particle size described in Example 1 were not used; instead, in Comparative Example 1, based on a 100 wt% hydrophilicity-hydrophobicity controlled matrix, a single ultrafine silica particle with an average particle size (D50) of 20 nm was used.

[0109] Comparative Example 2

[0110] In Comparative Example 2, the coating composition and preparation process were essentially the same as in Example 1. The difference was that in Comparative Example 2, based on a 100wt% hydrophilicity-phobicity controlled matrix, the three different particle sizes of silica particles described in Example 1 were not used; instead, in Comparative Example 1, based on a 100wt% hydrophilicity-phobicity controlled matrix, 60wt% of silica particles with an average particle size (D50) of 18 to 25 nm and 40wt% of silica particles with an average particle size (D50) of 20 to 30 μm were used.

[0111] Comparative Example 3

[0112] In Comparative Example 3, the coating composition and preparation process were essentially the same as in Example 1. The difference was that, in Comparative Example 3, 50 parts by weight of a hydrophilic-hydrophobic modulating matrix were used relative to 200 parts by weight of the silicone oil-based composition.

[0113] Comparative Example 4

[0114] In Comparative Example 4, the coating composition and preparation process were essentially the same as in Example 1. The difference was that, in Comparative Example 4, 20 parts by weight of aniline-formaldehyde resin were not used. Instead, 20 parts by weight of polytetrafluoroethylene (PTFE) resin powder was used.

[0115] Comparative test results

[0116] The same tests as those in the examples were performed on the above comparative examples. The test results are shown in the table below.

[0117] Table 4: Test Results of the Comparative Experiment

[0118]

[0119] In general, this invention relates to and realizes a room-temperature curable, highly insulating, heat-resistant coating, and its application. By adding organic components such as aniline-formaldehyde resin powder fillers (with benzene rings and amino groups tending to be positively charged) that have electrostatic attraction with the benzene rings (which tend to be negatively charged) of phenyl silicone rubber, the heat resistance of the coating is improved. Simultaneously, because the benzene rings on the silicone rubber and the benzene-amino groups of the organic components have opposite charges, they can effectively stack together, reducing the generation of defective structures. Furthermore, the positive and negative polarity materials, when the polarity is controlled by applying charge, are combined with inorganic oxygen with a specific particle size distribution and the potential for porosity. Silicon particles can control the overall charge distribution and content of the coating, achieving partial rather than complete cancellation between the substrate and the applied charge. This allows the contact wetting angle to be controlled, for example, between approximately 15° and 165°, without reaching an extremely hydrophilic (close to 0°) or extremely hydrophobic (close to 180°) state due to excessive charge application or heating exceeding the threshold. This is preferred in many application scenarios in the field of wetting control, and the overall field strength of the coating is as high as 23kV / mm or more. The incomplete wetting or incomplete hydrophobic state is beneficial for users to apply and control the corresponding surfaces.

[0120] Non-limitingly, for example, in Comparative Example 1, when all fine silica particles are used, the adjustable angle in the water contact angle control test becomes smaller. This may be because the charge accumulated in a large number of fine silica particles is less easily discharged by the heating process compared to large silica particles. Therefore, more residual static charge inevitably accumulates inside the coating, making it impossible to achieve non-polar superhydrophobic properties. On the other hand, the charge characteristics of silica particles with small cavities may also be affected during charging, thus affecting the superhydrophilic properties during polarization. The inventors also found that when only fine silica particles are used as fillers, the thermal conductivity also increases (the heat insulation effect deteriorates slightly). It is evident that a certain proportion of relatively large silica fillers can not only maintain effective charge and discharge efficiency but also effectively support the thermal conductivity of the coating. At the same time, the corresponding heat resistance is slightly reduced in Comparative Example 1 (i.e., the temperature of the coating on the side away from the heating source increases in the heat resistance test). When a combination of fine particles and large-diameter silica particles is used in the coating (as in Comparative Example 2), although specific heat capacity and heat resistance are guaranteed to a certain extent, the inventors found that the coating's resistance to charge breakdown significantly decreased. This may be because the large silica (hollow) particles lead to poor coating uniformity, causing the voltage to break through from thinner (or uneven) areas of the coating during voltage breakdown experiments, resulting in reduced compressive strength. Similarly, the inventors found that when the proportion of the modulating matrix (similar to coating aggregate) is too high (Comparative Example 3), for example, when the hydrophilic / hydrophobic modulating matrix exceeds 25 wt% or 30 wt% of the silicone oil-based composition, the coating's adhesion and breakdown resistance decrease. This may also be due to the reduced coating uniformity caused by excessive silica particles. Furthermore, in practical applications, excessive matrix components can lead to uneven coating thickness in applications such as flow control pipelines, affecting the smoothness of fluid control. In large areas such as the top of new energy vehicles, uneven coating or excessive local protrusions can affect the aesthetics and durability of the coating.

[0121] In a preferred embodiment of the present invention, the mass ratio of the silicone oil base composition to the hydrophilic-hydrophobic control matrix is ​​preferably between 10:(1-2), which is beneficial for obtaining balanced and improved coating properties.

[0122] When the inventors used non-polar polytetrafluoroethylene filler to replace aniline formaldehyde resin with a benzene ring-amino structure (which tends to carry a positive charge) (Comparative Example 4), the matrix lost the components of phenyl vinyl silicone oil and phenyl hydrogen silicone oil that tend to carry a negative charge. Due to the charge in the matrix, the polarity of the coating could not be largely eliminated, resulting in a contact angle that could not exceed 135° in hydrophobic adjustment. In hydrophilic tests, a highly hydrophilic surface was prone to appear (which is unfavorable in the field of fluid control), which increased the difficulty of controlling the surface wettability.

[0123] Based on the embodiments and technical content described in this specification, the present invention can provide at least the following technical solutions: Although this disclosure includes specific embodiments, it will be apparent to those skilled in the art that various substitutions or changes in form and detail can be made to these embodiments without departing from the inventive spirit and scope of the claims and their equivalents. The embodiments described herein should be considered illustrative only and not for limiting purposes. The description of features and aspects in each embodiment is considered applicable to similar features and aspects in other embodiments. Therefore, the scope of this disclosure should not be limited by the specific description, but rather by the technical solutions of the claims, and all variations within the scope of the claims and their equivalents are to be interpreted as included within the technical solutions of this disclosure.

Claims

1. A room temperature-curable silicone-based nanocoating, characterized by, The silicon-based nanocoating comprises, by weight parts, the following raw materials: A silicone oil base composition: 150 to 200 parts by weight; A hydrophilic-hydrophobic regulating matrix: 15 to 35 parts by weight; A matrix reinforcing fiber: 5 to 30 parts by weight; An aniline formaldehyde resin: 10 to 30 parts by weight; A diluent: 10 to 30 parts by weight; and The silicone oil base composition comprises an epoxy-terminated silicone oil with a weight average molecular weight of 10,000 to 12,000, a bifunctional phenyl vinyl silicone oil with a weight average molecular weight of 600 to 800, a bifunctional phenyl hydrogen-containing silicone oil with a weight average molecular weight of 600 to 900, and an adhesion enhancing component; and The hydrophilic-hydrophobic regulating matrix comprises two or more types of silica microparticles with different particle size distributions; and The hydrophilic-hydrophobic regulating matrix comprises three types of silica microparticles with different particle size distributions, and The first silica microparticles are nano-silica with a D50 average particle size of 8 to 15 nm, accounting for 10 wt% to 20 wt% of the total mass of the silica microparticles; The second silica microparticles are nano-silica with a D50 average particle size of 50 to 75 nm, accounting for 30 wt% to 45 wt% of the total mass of the silica microparticles; The third silica microparticles are silica microparticles with a D50 average particle size of 1 to 3 microns, accounting for 40 wt% to 50 wt% of the total mass of the silica microparticles; and The mass ratio of the silicone oil base composition to the hydrophilic-hydrophobic regulating matrix is between 10: (1-2); and wherein The hydrophilic-hydrophobic regulating matrix is prepared by mixing and stirring the silica microparticles with tetraethyl orthosilicate and heptadecafluorodecyltrimethoxysilane.

2. The room temperature curing type silicon-based nano-coating according to claim 1, characterized in that, The silicone oil base composition comprises, calculated based on 100 wt% of the total weight of the silicone oil base composition: 25 wt% to 30 wt% of an epoxy-terminated silicone oil with a weight average molecular weight of 10,000 to 12,000; 55 wt% to 60 wt% of a bifunctional phenyl vinyl silicone oil with a weight average molecular weight of 600 to 800; 5 wt% to 10 wt% of a bifunctional phenyl hydrogen-containing silicone oil with a weight average molecular weight of 600 to 900; 0.5 wt% to 1 wt% of an adhesion enhancing component; 0.1 wt% to 1 wt% of a control agent; and Anhydrous ethanol as a solvent.

3. The room temperature curing silicone-based nanocoating according to any one of claims 1 to 2, characterized in that, The ambient temperature curing type silicon-based nanocoating also satisfies one or more of the following conditions: The matrix reinforcing fiber is a quartz fiber with an average length of 20 microns to 40 microns and an aspect ratio greater than 10:1; The diluent is ethyl acetate; The ambient temperature curing type silicon-based nanocoating comprises tetrabutyl titanate as an auxiliary catalyst.

4. The room temperature curing silicone-based nanocoating according to any one of claims 1 to 2, characterized in that, The ambient temperature curing type silicon-based nanocoating is prepared by a method comprising the following steps: Step 1): Prepare each raw material component of the silicone oil base composition, and stir each component uniformly in a blender to obtain the silicone oil base composition; Step 2): 5 to 10 parts by weight of deionized water are prepared, and the weighed hydrophobicity-regulated substrate silica particles are put into the mixed solution for stirring; then, 5wt% to 10wt% of tetraethyl orthosilicate and 1wt% to 5wt% of heptadecafluorodecyltrimethoxysilane are added to the total mass of the solid content in the above hydrophobicity-regulated substrate, and the mixed system is fully stirred until it is not layered; a hydrophobicity-regulated substrate is obtained; Step 3): the above hydrophobicity-regulated substrate is mixed with the silicone oil base composition, and the corresponding weight fraction of reinforcing fibers is added and stirred to obtain a first intermediate; Step 4): the corresponding ratio of aniline formaldehyde resin is added to the first intermediate, and after mixing, a second intermediate is obtained; Step 5): the second intermediate is mixed with 3 to 5 parts by weight of an auxiliary catalyst, and the corresponding weight fraction of a diluent is added and stirred to obtain a room temperature curable silicone-based nanocoating.

5. A preparation method of a room temperature curable environmentally friendly silicone-based nanocoating, characterized in that, The room temperature curable silicone-based nanocoating is applied to the surface of a device or a substrate, and is cured at room temperature for 96 to 120 hours to obtain the silicone-based nanocoating.

6. The preparation method of a room temperature curable environmentally friendly silicone-based nanocoating according to claim 5, characterized in that, The thickness of the silicone-based nanocoating is between 500 microns and 5 millimeters.

7. The application of ambient-curable environment-friendly silicon-based nanometer coating, characterized in that, The coating prepared by the preparation method of a room temperature curable environmentally friendly silicone-based nanocoating according to any one of claims 5 or 6 is applied to the surface of a pipe of a flow control device, the outer surface of a building, the surface of a road, or the outer surface of a new energy vehicle.

8. The application of ambient-curable environment-friendly silicon-based nano-coating according to claim 7, characterized in that, After the coating is applied to the corresponding surface, the wetting angle of the coating surface with water droplets changes between 10° and 170°.

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