CN106146868A - Multifunctional antifogging coating and preparation method thereof - Google Patents

Abstract

The invention discloses a multifunctional anti-fog coating and a preparation method thereof. The multifunctional anti-fog coating includes at least one layer of anti-fog coating coated on the substrate and at least one layer of functional coating coated on the anti-fog coating; the anti-fog coating has hygroscopicity; The functional coating is water permeable. In addition to the excellent anti-fog performance of the multifunctional anti-fog coating prepared by the invention, by changing the composition of the functional coating on the outside of the anti-fog layer, a coating with both outer coating performance and anti-fog performance can be obtained. This result overturns the traditional theory that "the anti-fog layer must be the outermost", and will significantly advance the design of multifunctional materials, making various component materials present diversity and flexibility in spatial arrangement. The preparation method of the invention is safe, simple and easy, and has wide application; the obtained coating is suitable for inorganic glass, polymer plates or films, organic-inorganic composite plates, cables and aircraft shells and the like.

Description

A kind of multifunctional anti-fog coating and preparation method thereof

technical field

The present invention relates to the field of materials. More specifically, it relates to a multifunctional anti-fog coating and a preparation method thereof.

Background technique

Fog can cause image distortion and reduce light transmission. In practical applications, coatings with anti-reflection function (hereinafter referred to as anti-reflection) and anti-fog function have a good prospect in the application of glasses, goggles, lenses, analysis and medical optical devices. The super-hydrophilic coating has a contact angle with water of less than 5° within 0.5 seconds, allowing water to spread rapidly on the surface and exhibiting excellent performance. However, the preparation of super-hydrophilic coatings usually requires complicated steps, and even titanium dioxide coatings mostly require ultraviolet light to exhibit super-hydrophilic properties. At the same time, the anti-fog performance derived from superhydrophilic properties is often not long-lasting, because superhydrophilic properties tend to disappear over time.

At present, a lot of work is devoted to the construction of multifunctional films to have anti-fog properties and other properties such as anti-reflection, including the construction of super-hydrophilic inorganic interfaces, the composite of polymers and low-refractive index inorganic materials, and the construction of porous or moth-eye structures. polymer etc. These works have their own characteristics but the common feature is that the anti-fog layer is on the outermost. The underlying conventional wisdom that "the anti-fog layer must be on the outside" is a major obstacle in the design of multifunctional materials. Since the anti-fog layer is designed on the outermost layer, other coatings (such as hydrophobic coatings, anti-glare coatings, self-cleaning coatings, etc.) that must be designed on the outermost layer to effectively exert their functional properties cannot match the anti-fog performance. At the same time, if the anti-fog layer can be designed on the inner layer, then the selection and construction of the functional coating on the outer layer will present structural diversity and functional diversity.

Contents of the invention

One object of the present invention is to provide a multifunctional anti-fog coating.

Another object of the present invention is to provide a method for preparing a multifunctional anti-fog coating.

Unlike the anti-fog coating that utilizes the superhydrophilic properties of materials (contact angle less than 5°), the applicant's latest research shows (patent number 2014072500611940 and patent application number 2014090200731090): when the water molecules in the hot humid air When condensing on the polymer coating, due to the hydrogen bond interaction and dipole-dipole interaction between the polymer and the water molecules, the water molecules are quickly absorbed into the polymer to prevent the formation of water droplets on the polymer film, we will polymerize This property of substances is called hygroscopicity. Anti-fog polymer coatings derived from the hydrophilic and hygroscopic properties of polymer films have good anti-fog properties.

On this basis, the applicant first constructed a hygroscopic anti-fog coating, and then deposited a silicon dioxide hollow sphere coating on the anti-fog coating, and surprisingly obtained a composite coating with anti-fog and anti-reflection. As far as the applicant is aware, so far there is no synthetic coating that still exhibits excellent anti-fog and anti-reflection properties when the anti-fog layer is not on the outermost surface. By changing the composition of the coating outside the anti-fog layer, an anti-fog self-cleaning coating, an anti-fog and anti-glare coating, an anti-fog light-limiting coating, and an anti-fog hydrophobic coating can also be obtained. That is, coating other water-permeable coatings on the anti-fog coating can obtain a coating with both outer coating performance and anti-fog performance. This result overturns the traditional theory that "the anti-fog layer must be the outermost", and will significantly advance the design of multifunctional materials, making various component materials present diversity and flexibility in spatial arrangement.

In order to achieve the above-mentioned first object, the present invention adopts the following technical solutions:

A multi-functional anti-fog coating, the multi-functional anti-fog coating comprises at least one layer of anti-fog coating coated on the substrate and at least one functional coating coated on the anti-fog coating; The anti-fog coating is hygroscopic; the functional coating is water permeable.

Preferably, the anti-fog coating is selected from a hygroscopic polymer coating, a hygroscopic coating of a polymer crosslinked with an inorganic material, a hygroscopic coating of a polymer crosslinked with a polymer or Hygroscopic coatings of polymers mixed with inorganic materials.

Preferably, the functional coating is selected from coatings with anti-reflection properties, coatings with self-cleaning properties, coatings with anti-glare properties, coatings with optical limiting properties and coatings with hydrophobic properties one or more of.

Preferably, the coating with antireflection performance is a silica hollow sphere coating.

Preferably, the multifunctional anti-fog coating consists of one layer of anti-fog coating coated on the substrate and two layers of silica hollow sphere coatings coated on the anti-fog coating.

The present invention created the anti-fog layer for the first time with excellent anti-reflection and anti-fog performance, and pioneered and realized the structure of the anti-fog layer that can still have excellent anti-reflection and anti-fog performance in the inner layer concept and design.

Preferably, the substrate is selected from inorganic glass, polymer sheet, polymer film, organic-inorganic composite sheet, cable or aircraft shell.

In order to achieve the above-mentioned second purpose, the present invention adopts the following technical solutions:

A preparation method for a multifunctional anti-fog coating, comprising the steps of:

coating the substrate with at least one hygroscopic anti-fog coating;

At least one layer of water-permeable functional coating is coated on the anti-fog coating to obtain a multifunctional anti-fog coating.

Preferably, the coating method is pulling, spraying, spin coating, blade coating, rolling coating or manual coating.

Preferably, the preparation method of the anti-fog coating is divided into the following two types:

1. Anti-fog coating preparation method 1:

Referring to the patent (patent application number 2014072500611940), the specific steps are: 1) mixing the polymer powder containing hydroxyl groups in the main chain or side chain or the polymer containing amino groups in the main chain or side chain with water (can be heated and stirred in a water bath Prepared at a temperature of 80°C to 100°C, preferably 85°C to 100°C), to prepare an aqueous polymer solution with a mass concentration of 1% to 40% (preferably a mass concentration of 5% to 30%); 2) mixing the polymer aqueous solution obtained in step 1) with the polymer aqueous solution having a mass concentration of 1% to 85% (preferably 10% to 70%) in the main chain or side chain containing carboxyl groups, and stirring to obtain a mixed solution , wherein the volume ratio of the aqueous polymer solution in step 1) to the aqueous polymer solution containing carboxyl groups in the main chain or side chain is 1:1 to 1:58; 3) using acid, alkali or salt to mix the obtained product in step 2) The pH of the solution is adjusted to a pH range of 1 to 13 (preferably a pH of 1 to 4), and after stirring for a certain period of time, ultrasonic or static defoaming; 4) Coating the solution obtained in step 3) after defoaming on a solid substrate , followed by heat treatment to obtain a cross-linked polymer coating with self-healing properties, water resistance, long-lasting anti-fog, anti-frost, high hardness and scrub resistance. The polymer containing hydroxyl groups in the main chain or side chain is selected from one of polyvinyl alcohol (PVA), polyethylene glycol, and block copolymers of polyethylene glycol. The polymer containing amino groups in the main chain or side chain is polyvinylamine or polypropyleneamine. The polymer containing carboxyl groups in the main chain or side chain is polyacrylic acid (PAA) or polymethacrylic acid. Described acid is hydrochloric acid, sulfuric acid, nitric acid, phosphoric acid or acetic acid etc. Described alkali is sodium hydroxide or potassium hydroxide etc. The salt is potassium hydrogen sulfate, sodium hydrogen sulfate, disodium hydrogen phosphate, dipotassium hydrogen phosphate, sodium dihydrogen phosphate or potassium dihydrogen phosphate, etc. The coating described in step 4) adopts the methods of lifting, spraying, spin coating, scraping, rolling or manual coating. The solid substrate is a glass substrate, a high temperature resistant polymer plate, a high temperature resistant polymer film, a cable or an aircraft shell and the like. The temperature range of the heat treatment is 20°C to 150°C, preferably 100°C to 140°C. The heat treatment time is 1 minute to 720 hours, preferably 2 minutes to 7 hours.

2. Anti-fog coating preparation method 2:

Refer to the patent (patent application number 2014090200731090), the specific steps are: 1) mix the polymer powder containing hydroxyl groups in the main chain or side chain with water (it can be prepared under the conditions of heating and stirring in a water bath, such as the heating temperature is 80 ℃ ~100°C, preferably 85°C~100°C), prepared into an aqueous polymer solution with a mass concentration of 1% to 40% (preferably a mass concentration of 5% to 30%); 2) the mixed solution of organosilane reagent and ethanol Add dropwise to the polymer aqueous solution obtained in step 1), stir at the temperature of a water bath at a temperature of 0°C to 100°C (preferably 30°C to 90°C), add an inorganic acid, and adjust the pH of the solution to 1 to 7 , continue to stir, add organosilane coupling agent after the solution is transparent, stir, stand at room temperature for defoaming, and suction filter the liquid after standing defoaming and polymer crosslinking to remove the precipitate; 3) Step 2) The liquid obtained after suction filtration to remove the precipitate is coated on a solid substrate, and dried naturally or in an oven to obtain a water-resistant, long-lasting, anti-fog, and anti-frost coating with a high light transmittance with a network structure and a controllable cross-linking degree . Said polymer is cross-linked, the cross-linking degree (hydroxyl bonding ratio) of the polymer is 5% to 60%, and the cross-linking degree (hydroxyl bonding ratio) is composed of a polymer containing hydroxyl groups in the main chain or side chain The ratio of the amount of the hydroxyl group involved in the crosslinking reaction in the polymer crosslinking to the amount of the hydroxyl group in the polymer containing the hydroxyl group in the main chain or the side chain before the polymer crosslinking reaction is determined. The crosslinking degree leads to the controllable crosslinking degree of the prepared water-resistant, long-lasting anti-fog and anti-frost coating with high light transmittance. The addition of organosilane reagent and organosilane coupling agent in step 2) is according to the amount of substance of hydroxyl group and the amount of substance of organosilane reagent in the polymer containing hydroxyl group in the main chain or side chain described in step 1). The ratio is 5:1-100:1, and the ratio of the amount of hydroxyl group in the polymer containing hydroxyl group in the main chain or side chain to the amount of organosilane coupling agent is 5:1-1:0. Further step 2) the addition of organosilane reagents and organosilane coupling agents, preferably according to the amount of the substance of the hydroxyl group in the polymer containing hydroxyl groups in the main chain or side chain described in step 1) and the organosilane The total substance ratio of the reagent and the organosilane coupling agent is 5:1-100:1. The mass ratio of the organic silane reagent to ethanol in the mixed liquid of the organic silane reagent and ethanol is 1:10 to 1:0. The stirring time is 0.2-72 hours, preferably 0.3-7 hours. The time for standing to defoam is 0.2 to 72 hours, preferably 0.3 to 7 hours. The coating is carried out by pulling, spraying, spin coating, scraping, rolling or manual coating. Said drying in an oven, the drying temperature ranges from 20°C to 150°C. The polymer containing hydroxyl groups in the main chain or side chain is selected from one or more of polyvinyl alcohol, polyethylene glycol, and polyethylene glycol block copolymers. The organosilane reagent is selected from one of 3-aminopropyltriethoxysilane, chlorosilane, tetramethoxysilane, ethyl orthosilicate, propyl orthosilicate, and isopropyl orthosilicate or several. Described inorganic acid is selected from the one in hydrochloric acid, sulfuric acid, nitric acid, phosphoric acid. The organosilane coupling agent is selected from γ-aminopropyl trimethoxysilane, aminopropyl triethoxysilane, 3-glycidyl etheroxypropyl trimethoxysilane (KH-560), γ- Methacryloxypropyltrimethoxysilane, Vinyltriethoxysilane, Vinyltrimethoxysilane, Vinyltris(β-methoxyethoxy)silane, N-(β-aminoethyl One or more of -γ-aminopropyltriethoxysilane. Described solid substrate is selected from inorganic glass (such as K7105 glass, 5 mm thick process glass, slide glass etc.), polymer plate or film (such as polycarbonate (PC), polymethyl methacrylate (PMMA) , automotive sunscreen film, resin lenses, polyethylene terephthalate (PET)), cables, aircraft casings and other materials that require anti-fog, anti-frost and anti-freeze.

Preferably, the preparation method of the silica hollow sphere coating is divided into the following two steps:

One. The preparation of the sol solution containing silica hollow sphere nanoparticles:

Refer to the patent (patent application No. 201410758433.3), specifically: dissolve 0.1g to 0.7g of polyacrylic acid in 4.5ml of ammonia water, and ultrasonically disperse; then add dropwise into a container loaded with 90ml of absolute ethanol, stir to obtain a mixed solution; 1 ml to 4 ml of tetraethoxysilane was added dropwise to the mixture at a rate of 45 microliters per minute; after the addition, the resulting solution was stirred at room temperature to obtain hollow spheres containing silica The sol solution of nanoparticles;

2. Preparation of silica hollow sphere coating:

The sol solution containing silica hollow sphere nanoparticles is coated on the anti-fog coating by pulling, spraying, spin coating, scraping coating, rolling coating or manual coating. By changing the number of times of coating the silica hollow sphere sol solution, one layer of silica hollow spheres/anti-fog coating, 2 layers of silica hollow spheres/anti-fog coating, 3 layers of silica hollow spheres/ Anti-fog coating.

The beneficial effects of the present invention are as follows:

In addition to the excellent anti-fog performance of the multifunctional anti-fog coating prepared by the present invention, by changing the composition of the functional coating outside the anti-fog layer, it is also possible to obtain an anti-fog self-cleaning coating, an anti-fog and anti-glare coating, Anti-fog light limiting coating, anti-fog hydrophobic coating. That is, coating other water-permeable coatings on the hygroscopic anti-fog coating can obtain a coating with both outer coating performance and anti-fog performance. This result overturns the traditional theory that "the anti-fog layer must be the outermost", and will significantly advance the design of multifunctional materials, making various component materials present diversity and flexibility in spatial arrangement. The method of the present invention is safe, simple and easy, and has a wide range of applications; the gained coating is applicable to inorganic glass (such as K7105 glass, 5 millimeters thick process glass, slide glass, etc.), polymer plate or film (such as polycarbonate ( PC), polymethyl methacrylate (PMMA), automotive sunscreen film, resin lens, polyethylene terephthalate (PET)), organic-inorganic composite sheet, cable, aircraft shell.

Description of drawings

The specific implementation manners of the present invention will be further described in detail below in conjunction with the accompanying drawings.

FIG. 1 shows a schematic diagram of preparing an anti-fog and anti-reflective coating according to Example 1 of the present invention.

FIG. 2 shows the topography of the anti-fog and anti-reflection coating prepared in Example 1 of the present invention. Among them, (a) is the scanning electron micrograph of the 2-layer hollow sphere/anti-fog coating, (b) is the transmission electron micrograph of the silica hollow sphere, and (c) is the photo of the 2-layer hollow sphere/anti-fog coating Scanning electron microscope photo side view.

Fig. 3 shows blank glass in Example 1 of the present invention, a glass sample coated with 1 layer of hollow sphere/anti-fog layer, a glass sample coated with 2 layers of hollow sphere/anti-fog layer, and covered with 3 layers of hollow sphere/anti-fog layer The light transmittance of the glass sample in the wavelength range of 300-900nm.

Figure 4 shows the anti-fog test photos taken immediately after the glass sample covered by 2 layers of hollow spheres, anti-fog layer and 2-layer hollow sphere/anti-fog layer in Example 1 of the present invention was placed in a refrigerator at 6°C for 24 hours. Among them, (a) is the anti-fog test comparison chart of the glass sample covered with two layers of hollow spheres and the blank glass, (b) is the anti-fog test comparison chart of the glass sample covered with the anti-fog layer and the blank glass, and (c) is 2 Anti-fog test comparison chart of glass samples covered with layer hollow sphere/anti-fog layer and blank glass.

Fig. 5 shows water in the blank glass (a), the glass sample (b) covered by 2 layers of hollow spheres, the glass sample (c) covered by anti-fog layer, and covered by 2 layers of hollow spheres/anti-fog layer in Example 1 of the present invention The contact angle on the glass sample (d).

Figure 6 shows that in Example 1 of the present invention, water vapor meets blank glass (a), glass sample (b) covered by 2 layers of hollow spheres, glass sample (c) covered by anti-fog layer, 2 layers of hollow spheres/anti-fog Schematic representation of the behavior of layer-covered glass samples (d).

detailed description

In order to illustrate the present invention more clearly, the present invention will be further described below in conjunction with preferred embodiments and accompanying drawings. Similar parts in the figures are denoted by the same reference numerals. Those skilled in the art should understand that the content specifically described below is illustrative rather than restrictive, and should not limit the protection scope of the present invention.

Example 1

Mix polyvinyl alcohol (PVA) powder with water, prepare a PVA aqueous solution with a mass concentration of 10% under the condition of heating and stirring in a water bath at a temperature of 85°C, and then add 38.20ml to 42.17ml of PVA with a mass concentration of 10% The aqueous solution and 7.83ml～11.80ml of polyacrylic acid (PAA) aqueous solution with a mass concentration of 53% are mixed under sufficient stirring conditions to obtain a mixed solution, and the pH of the mixed solution is adjusted to 1～4 with hydrochloric acid or sodium hydroxide, and ultrasonically Or stand for 24 hours for degassing, and apply the liquid obtained after degassing (using one of the methods of pulling, spraying, spin coating, scraping, roller coating, and manual coating) on ordinary glass at a temperature of 100 ° C ~ Heat treatment at a high temperature of 140°C for 2 minutes to 7 hours, and then cool to room temperature to obtain a cross-linked, self-healing, water-resistant, long-term anti-fog, high hardness and scrub-resistant polymer coating with high light transmittance on the surface of ordinary glass.

Dissolve 0.1g to 0.7g of polyacrylic acid in 4.5ml of ammonia water, and ultrasonically disperse it; then add it dropwise into a container filled with 90ml of absolute ethanol, and stir to obtain a mixed solution; add 1ml to 4ml of tetraethoxy Base silane was added dropwise to the mixed solution at a rate of 45 microliters per minute; after the dropwise addition, the resulting solution was stirred at room temperature to obtain a sol solution containing silica hollow sphere nanoparticles;

Apply the obtained sol solution containing silica hollow sphere nanoparticles to the anti-fog coating by pulling, spraying, spin coating, scraping, rolling or manual coating to obtain an anti-reflective anti-fog coating . By changing the times of coating the silica hollow sphere sol solution, we obtained glass samples covered with 1 layer of hollow spheres/anti-fog layer, 2 layers of hollow spheres/anti-fog layer, and 3 layers of hollow spheres/anti-fog layer.

The formation process of the coating is shown in FIG. 1 . We first coated the anti-fog layer on the substrate, and then coated the silica hollow sphere coating on the anti-fog layer. By changing the times of coating the silica hollow sphere sol solution, we obtained glass covered with 1 layer of hollow spheres/anti-fog layer, 2 layers of hollow spheres/anti-fog layer, and 3 layers of hollow spheres/anti-fog layer. FIG. 2 shows the topography of the anti-fog and anti-reflection coating prepared in Example 1 of the present invention. Among them, (a) is a scanning electron microscope photo of 2 layers of hollow spheres/anti-fog coating, which shows that hollow silica spheres are densely packed on the anti-fog layer, and there are many gaps on the hollow silica sphere layer. Pores and crevices, these spaces provide access for water molecules to enter the hydrophilic, hygroscopic polymer film. (b) is a transmission electron microscope photo of the silica hollow spheres, it can be seen that the average outer diameter of the silica hollow spheres is 41 nm, and the inner diameter is 19 nm. (c) is a side view of the scanning electron micrograph of the 2-layer hollow sphere/anti-fog coating, which shows that the thickness of the inner polymer anti-fog layer is 7.1 μm.

The optical property of described coating, anti-fog performance are as follows:

optical properties

The light transmittance of blank glass, anti-fog layer, 1-layer hollow sphere/anti-fog layer, 2-layer hollow sphere/anti-fog layer, 3-layer hollow sphere/anti-fog layer glass samples is shown in Figure 3, obviously , the light transmittance of the glass substrate changed slightly by the anti-fog layer, however, the deposition of hollow spheres significantly changed the light transmittance of the sample. Therefore, the anti-reflection properties of the coating come from the low refractive index silica hollow sphere layer. Among them, the glass sample covered with 2 layers of hollow spheres/anti-fog layer has the most excellent anti-fog performance.

Table 1 In the blank glass in Example 1 of the present invention, the maximum wavelength of the glass samples covered with one layer of hollow spheres/anti-fog layer, two layers of hollow spheres/anti-fog layer, and three layers of hollow spheres/anti-fog layer in the wavelength range of 300-900nm Light transmittance and average light transmittance

As shown in Table 1, among the listed samples, the glass sample covered with 2 layers of hollow spheres/anti-fog layer has the highest maximum light transmittance of 98.9% in the wavelength range of 300-900nm, and the highest average light transmittance of 91.9 %.

Anti-fog properties

Figure 4 shows the anti-fog test photos taken immediately after the glass sample covered by 2 layers of hollow spheres, anti-fog layer and 2-layer hollow sphere/anti-fog layer in Example 1 of the present invention was placed in a refrigerator at 6°C for 24 hours. Among them, (a) is the anti-fog test comparison chart of the glass sample covered with two layers of hollow spheres and the blank glass, (b) is the anti-fog test comparison chart of the glass sample covered with the anti-fog layer and the blank glass, and (c) is 2 Anti-fog test comparison chart of glass samples covered with layer hollow sphere/anti-fog layer and blank glass. As shown in Figure 4, the blank glass part and the glass sample covered with 2 layers of hollow spheres were fogged, while the anti-fog layer and the part covered with 2 layers of hollow spheres/anti-fog layer were anti-fogged, and the text below was clearly visible. Therefore, it can be intuitively concluded that the anti-fog performance of the 2-layer hollow sphere/anti-fog layer does not come from the outer silica hollow sphere layer, but from the polymer anti-fog layer, although this layer is not the outermost.

Fig. 5 shows water in the blank glass (a), the glass sample (b) covered by 2 layers of hollow spheres, the glass sample (c) covered by anti-fog layer, and covered by 2 layers of hollow spheres/anti-fog layer in Example 1 of the present invention The contact angle on the glass sample (d). The figure shows: blank glass, 2 layers of hollow spheres, anti-fog layer, 2 layers of hollow spheres/anti-fog layer covered glass with water contact angles of 49.4°, 18.0°, 56.8°, 37.5° respectively, none of them are super Hydrophilic.

The anti-fog performance of the 2-layer hollow ball/anti-fog layer does not come from the super-hydrophilic anti-fog mechanism of the traditional concept. We investigated the anti-fog mechanism of polymer coatings using a quartz crystal microbalance. As mentioned earlier, there are many gaps, holes, and cracks in the silica hollow sphere layer, which can allow water molecules to shuttle through. Due to the hydrogen bond interaction and dipole-dipole interaction between water molecules and polymers, water molecules will be trapped. Absorbs quickly into the polymer layer. During the anti-fog test, the mass of water absorbed into the polymer layer was measured with a quartz crystal microbalance, and the results showed that the water absorption of the polymer anti-fog layer of 6.78×10 ^-9 g during the anti-fog test was 3.69× 10 ^-10 g, that is, the mass of the coating increases by 5.45wt% due to water absorption. In conclusion, the anti-fog performance of the 2-layer hollow sphere/anti-fog layer does not come from the outer silica hollow sphere layer, but from the polymer anti-fog layer, although this layer is not the outermost.

When a surface encounters hot, humid air, fog will form within the first few seconds of contact, so anti-fog in the initial stages is important, as subsequent fogging will occur as the substrate adapts to the temperature and humidity of the environment The fog is not serious or even disappears. During the anti-fog test, the behavior of water vapor when it encounters blank glass, glass covered with 2 layers of hollow spheres, anti-fog layer, and 2 layers of hollow spheres/anti-fog layer is shown in Figure 6. s, water droplets formed on the blank glass and the glass sample covered with 2 layers of hollow spheres, however, no water droplets formed on the anti-fog layer, 2-layer hollow sphere/anti-fog layer coating, water molecules were absorbed into the polymer layer, From the scanning electron microscope side view, the thickness of the polymer coating is 7.1 μm, indicating that the polymer coating has enough space to accommodate water molecules. The source of the anti-fog performance of the 2-layer hollow sphere/anti-fog layer coating: 1. The hygroscopicity of the polymer coating provides the internal driving force; 2. The gaps, holes, and cracks in the silica hollow sphere layer provide the Paths for water molecules to travel. The 2-layer hollow sphere/anti-fog layer coating still maintains good anti-fog performance after being stored for 10 months, which shows that the anti-fog performance of this coating has a long-term effect.

Example 2

With reference to Example 1, the difference is that polyvinyl alcohol (PVA) powder is mixed with water, and it is 10% PVA aqueous solution that the mass concentration is prepared under the condition of heating and stirring in a water bath at a temperature of 85°C, and then 38.20ml～ 42.17ml mass concentration is 10% PVA aqueous solution and 7.83ml～11.80ml mass concentration is that 53% polyacrylic acid (PAA) aqueous solution is mixed under the condition of sufficient agitation to obtain mixed liquid, replaces PVA powder and water mixing, in The temperature is 85 ℃ of water bath heating and under the condition of stirring to prepare the PVA aqueous solution that the mass concentration is 10%, and then 42.18ml～44.49ml mass concentration is the PVA aqueous solution of 10% and 5.51ml～7.82ml mass concentration is the PVA aqueous solution of 53%. The PAA aqueous solution was mixed under sufficient stirring conditions to obtain a mixed solution, and the same result as in Example 1 could still be obtained.

Example 3

With reference to Example 1, the difference is that polyvinyl alcohol (PVA) powder is mixed with water, and it is 10% PVA aqueous solution that the mass concentration is prepared under the condition of heating and stirring in a water bath at a temperature of 85°C, and then 38.20ml～ 42.17ml mass concentration is 10% PVA aqueous solution and 7.83ml～11.80ml mass concentration is that 53% polyacrylic acid (PAA) aqueous solution is mixed under the condition of sufficient agitation to obtain mixed liquid, replaces PVA powder and water mixing, in The temperature is 85 DEG C of water bath heating and under the condition of stirring to prepare the PVA aqueous solution that mass concentration is 10%, then 44.50ml～45.75ml mass concentration is 10% PVA aqueous solution and 4.25ml～5.50ml mass concentration is 53% The PAA aqueous solution was mixed under sufficient stirring conditions to obtain a mixed solution, and the same result as in Example 1 could still be obtained.

Example 4

With reference to Example 1, the difference is that polyvinyl alcohol (PVA) powder is mixed with water, and it is 10% PVA aqueous solution that the mass concentration is prepared under the condition of heating and stirring in a water bath at a temperature of 85°C, and then 38.20ml～ 42.17ml mass concentration is 10% PVA aqueous solution and 7.83ml～11.80ml mass concentration is that 53% polyacrylic acid (PAA) aqueous solution is mixed under the condition of sufficient agitation to obtain mixed liquid, replaces PVA powder and water mixing, in The temperature is 85 DEG C of water bath heating and under the condition of stirring to prepare the PVA aqueous solution that the mass concentration is 10%, then mix 45.76ml～47.08ml of the PVA aqueous solution with the mass concentration of 10% and 2.92ml～4.24ml of the PVA solution with the mass concentration of 53%. The PAA aqueous solution was mixed under sufficient stirring conditions to obtain a mixed solution, and the same result as in Example 1 could still be obtained.

Example 5

With reference to Example 1, the difference is that polyvinyl alcohol (PVA) powder is mixed with water, and it is 10% PVA aqueous solution that the mass concentration is prepared under the condition of heating and stirring in a water bath at a temperature of 85°C, and then 38.20ml～ 42.17ml mass concentration is 10% PVA aqueous solution and 7.83ml～11.80ml mass concentration is that 53% polyacrylic acid (PAA) aqueous solution is mixed under the condition of sufficient agitation to obtain mixed liquid, replaces PVA powder and water mixing, in The temperature is 85 ℃ of water bath heating and under the condition of stirring to prepare the PVA aqueous solution that the mass concentration is 10%, then mix 47.09ml～49.98ml of the PVA aqueous solution with the mass concentration of 10% and 0.02ml～2.91ml of the PVA solution with the mass concentration of 53%. The PAA aqueous solution was mixed under sufficient stirring conditions to obtain a mixed solution, and the same result as in Example 1 could still be obtained.

Example 6

Referring to Example 1, the difference is that the anti-fog and anti-reflection coating can still be obtained by replacing the ordinary glass substrate with a high-temperature-resistant polymer sheet such as PET or a high-temperature-resistant polymer film.

Example 7

With reference to Example 1, the difference is that hydrochloric acid or sodium hydroxide is used to adjust the pH of the mixed solution to 1 to 4, and hydrochloric acid, sulfuric acid, nitric acid, phosphoric acid, acetic acid, sodium hydroxide, potassium hydroxide, potassium hydrogensulfate are used instead , sodium hydrogen sulfate, disodium hydrogen phosphate, dipotassium hydrogen phosphate, sodium dihydrogen phosphate or potassium dihydrogen phosphate etc. to adjust the pH of the mixed solution to be 4.5 or 13, still can obtain the same result as embodiment 1.

Example 8

Referring to Example 5, the difference is that 47.09ml～49.98ml of mass concentration is 10% of the PVA aqueous solution and 0.02ml～2.91ml of mass concentration of 53% of the PAA aqueous solution is replaced by PVA aqueous solution and PAA aqueous solution enlarged in equal proportions, such as , 49.98ml mass concentration is 10% PVA aqueous solution and 0.02ml mass concentration is the PAA aqueous solution of 53% to be 99.96ml mass concentration is 10% PVA aqueous solution and 0.04ml mass concentration is 53% PAA aqueous solution, still can The same results as in Example 5 were obtained.

Example 9

Referring to Example 5, the difference is that 47.09ml～49.98ml of a mass concentration of 10% PVA aqueous solution and 0.02ml～2.91ml of a mass concentration of 53% of a PAA aqueous solution are replaced by polyvinyl alcohol aqueous solution and polyacrylic acid in the same mass ratio Aqueous solution, for example, 47.09ml～49.98ml mass concentration is 10% PVA aqueous solution and 0.02ml～2.91ml mass concentration is 53% PAA aqueous solution to replace with 23.55ml～24.99ml mass concentration is 20% PVA aqueous solution and 0.04ml～ 5.82ml mass concentration is the PAA aqueous solution of 26.5%, still can obtain the result identical with embodiment 5.

Example 10

Referring to Example 5, the difference is that the high temperature treatment time is replaced by 1 minute or 720 hours, and the same result as Example 5 can still be obtained.

Example 11

With reference to Example 5, the difference is that 47.09ml～49.98ml mass concentration is 10% PVA aqueous solution and 0.02ml～2.91ml mass concentration is 53% PAA aqueous solution is replaced by 3.55ml mass concentration is 40% PVA aqueous solution and 46.45ml mass concentration is 1% PAA aqueous solution, still can obtain the result identical with embodiment 5.

Example 12

With reference to Example 5, the difference is that 47.09ml～49.98ml mass concentration is 10% PVA aqueous solution and 0.02ml～2.91ml mass concentration is 53% PAA aqueous solution to replace 49.81ml mass concentration as 1% PVA aqueous solution and 0.19ml mass concentration is the PAA aqueous solution of 85%, still can obtain the result identical with embodiment 5.

Example 13

Referring to Example 5, the difference is that PVA is replaced by polyethylene glycol or a block copolymer of polyethylene glycol or a polymer containing hydroxyl groups in the main chain or side chain, or replaced by polypropylene amine or polyethylene amine, etc. For polymers containing amino groups in the main chain or side chains, the same results as in Example 5 can still be obtained by replacing PAA with polymers containing carboxyl groups in the main chain or side chains such as polymethacrylic acid.

Example 14

1) In a container, mix PVA powder with water, and prepare a PVA aqueous solution with a mass concentration of 10% under the conditions of heating and stirring in a water bath at a temperature of 85°C;

2) Add 2.07ml to 3.55ml of a mixture of tetraethyl orthosilicate (TEOS) and ethanol (1:3 in mass ratio) dropwise to 50ml of the PVA aqueous solution obtained in step 1) with a mass concentration of 10%, wherein, The ratio of the amount of hydroxyl groups in PVA to the amount of tetraethyl orthosilicate is 6.6:1~11.4:1; stir for 0.2~72 hours at a reaction temperature of 0°C~100°C in a water bath, and then add nitric acid to adjust the solution The pH of the solution is 1 to 7, continue to stir for 0.2 to 72 hours, and add 0.05ml of 3-glycidyl etheroxypropyl trimethoxysilane after the solution is transparent, wherein the amount of hydroxyl in PVA is the same as that of 3-glycidol The molar ratio of etheroxypropyl trimethoxysilane is 53973:1; stir for 0.2-72 hours, stand at room temperature for 0.2-72 hours for defoaming, and after standing for defoaming and PVA cross-linking (cross-linking degree Suction filtration of the liquid (greater than or equal to 35% to less than or equal to 60%) to remove the precipitate;

3) The liquid obtained after step 2) is suction filtered to remove the precipitate, and coated on inorganic glass (such as K7105 glass, 5 mm thick process glass) by pulling, spraying, spin coating, scraping, rolling or manual coating. , glass slides, etc.), polymer sheets or films (such as polycarbonate (PC), polymethyl methacrylate (PMMA), automotive sunscreen film, resin lenses, polyethylene terephthalate (PET) ) and other solid substrates, dry naturally or in an oven at 20°C to 150°C to obtain a water-resistant, long-lasting, anti-fog, and anti-frost transparent coating with a network structure and a controllable degree of cross-linking.

4) Dissolve 0.1 gram to 0.7 gram of polyacrylic acid in 4.5 milliliters of ammonia water, and ultrasonically disperse it; then add it dropwise into a container filled with 90 milliliters of absolute ethanol, and stir to obtain a mixed solution; 1 milliliter to 4 milliliters of four Ethoxysilane was added dropwise to the mixed solution at a rate of 45 microliters per minute; after the dropwise addition, the resulting solution was stirred at room temperature to obtain a sol solution containing silica hollow sphere nanoparticles;

5) Apply the obtained sol solution containing silica hollow sphere nanoparticles to the anti-fog coating by pulling, spraying, spin coating, scraping, rolling or manual coating to obtain an anti-reflection anti-fog coating layer.

Example 15

Referring to Example 14, the difference is that a mixture of 2.07ml to 3.55ml of tetraethyl orthosilicate (TEOS) and ethanol (1:3 in mass ratio) is added dropwise to 50ml of step 1) with a mass concentration of 10% to obtain In the PVA aqueous solution, wherein, the ratio of the amount of the hydroxyl group in the PVA to the amount of the ethyl orthosilicate is 6.6:1 to 11.4:1; the reaction temperature is 0°C to 100°C and the water bath temperature is stirred for 0.2~ After 72 hours, add nitric acid to adjust the pH of the solution to 1-7, continue to stir for 0.2-72 hours, and add 0.05ml of 3-glycidyl etheroxypropyl trimethoxysilane after the solution is transparent. The ratio of the amount of 3-glycidyl etheroxypropyl trimethoxysilane to the amount of substance is 53973:1; stir for 0.2 to 72 hours, stand at room temperature for 0.2 to 72 hours for defoaming, and put the standing defoaming and PVA Suction filtration of the liquid after cross-linking (the degree of cross-linking is greater than or equal to 35% to less than or equal to 60%) to remove the precipitate; replace it with 0.30ml ~ 2.06ml tetraethyl orthosilicate (TEOS) and ethanol (mass ratio: 1: 7) the mixed solution is added dropwise to 50ml mass concentration and is 10% step 1) in the PVA aqueous solution that obtains, under the water bath temperature of reaction temperature 0 ℃～100 ℃, stir 0.2～72 hours, add the pH of nitric acid adjustment solution to be 1~7, continue to stir for 0.2~72 hours, add 0.05ml 3-glycidyl etheroxypropyl trimethoxysilane after the solution is transparent, stir for 0.2~72 hours, stand at room temperature for 0.2~72 hours, The liquid after static defoaming and PVA cross-linking (the cross-linking degree is greater than or equal to 5% to less than 35%) is suction filtered to remove the precipitate; the same result as in Example 14 can still be obtained.

Example 16

Referring to Example 14, the difference is that ethyl orthosilicate is replaced by 3-aminopropyltriethoxysilane, chlorosilane, tetramethoxysilane, propyl orthosilicate or isopropyl orthosilicate, etc. , all can obtain the same result as embodiment 14.

Example 17

Referring to Example 14, the difference is that nitric acid is replaced by hydrochloric acid, sulfuric acid or phosphoric acid, and the same results as in Example 14 can be obtained.

Example 18

Referring to Example 14, the difference is that a mixture of 2.07ml to 3.55ml of tetraethyl orthosilicate (TEOS) and ethanol (1:3 in mass ratio) is added dropwise to 50ml of PVA aqueous solution with a mass concentration of 10%. Instead, add 0.21ml to 0.35ml of tetraethyl orthosilicate (TEOS) and ethanol (mass ratio: 1:3) dropwise to 50ml of PVA aqueous solution with a mass concentration of 1%. same result.

Example 19

Referring to Example 14, the difference is that a mixture of 2.07ml to 3.55ml of tetraethyl orthosilicate (TEOS) and ethanol (1:3 in mass ratio) is added dropwise to 50ml of PVA aqueous solution with a mass concentration of 10%. Instead, add a mixture of 8.27ml to 14.18ml of tetraethyl orthosilicate (TEOS) and ethanol (10:1 in mass ratio) dropwise to 50ml of PVA aqueous solution with a mass concentration of 40%. same result.

Example 20

Referring to Example 14, the difference is that 3-glycidyl etheroxypropyl trimethoxysilane is replaced by aminopropyl triethoxysilane, γ-aminopropyl trimethoxysilane, γ-methyl Acryloxypropyltrimethoxysilane, Vinyltriethoxysilane, Vinyltrimethoxysilane, Vinyltris(β-methoxyethoxy)silane, N-(β-aminoethyl) -One or more in γ-aminopropyltriethoxysilane, all can obtain the result identical with embodiment 14.

Example 21

Referring to Example 14, the difference is that the mass ratio of ethyl orthosilicate (TEOS) and ethanol in the mixed solution of ethyl orthosilicate (TEOS) and ethanol is 1:3, and the mass ratio is 1: In the range of 10 to 1:0, the same result as in Example 14 can be obtained without any ratio of mass ratio of 1:3.

Example 22

Referring to Example 14, the difference is that the ratio of the amount of hydroxyl in PVA to the amount of tetraethyl orthosilicate is 6.6:1 to 11.4:1, and the ratio of the two is 5:1 to 100 :1 range, except that the content ratio is any ratio of 6.6:1 to 11.4:1, the same result as that of Example 14 can be obtained.

Example 23

Referring to Example 14, the difference is that the ratio of the amount of hydroxyl in PVA to the amount of 3-glycidyloxypropyltrimethoxysilane is 53973:1, and the ratio of the two is 5 :1～1:0, the same result as in Example 14 can be obtained regardless of any proportion with a content ratio of 53973:1.

Example 24

Referring to Example 14, the difference is that nitric acid is replaced by hydrochloric acid, sulfuric acid or phosphoric acid to adjust the pH of the solution to 1-7, and the same results as in Example 14 can be obtained.

Example 25

Referring to Example 14, the difference is that the amount of substances such as PVA, tetraethyl orthosilicate, ethanol, nitric acid, and 3-glycidyl etheroxypropyl trimethoxysilane is expanded, and the same degree of crosslinking can also be obtained. PVA liquid. For example, add 2.07ml~3.55ml of a mixture of tetraethyl orthosilicate (TEOS) and ethanol (1:3 in mass ratio) dropwise to 50ml of PVA aqueous solution with a mass concentration of 10%. Stir at a water bath temperature of ℃ for 0.2-72 hours, add nitric acid to adjust the pH of the solution to 1-7, continue stirring for 0.2-72 hours, add 0.05ml 3-glycidyl etheroxypropyl trimethoxyl after the solution is transparent Silane, stirring for 0.2-72 hours, standing at room temperature for degassing for 0.2-72 hours, suction-filtering the liquid after standing degassing and PVA cross-linking to remove the precipitate; replace it with 4.14ml-7.10ml of ethyl orthosilicate The mixture of (TEOS) and ethanol (mass ratio 1:3) was added dropwise to 100ml of PVA aqueous solution with a mass concentration of 10%, stirred at a reaction temperature of 0°C to 100°C for 0.2 to 72 hours, and added Adjust the pH of the solution to 1-7 with nitric acid, continue stirring for 0.2-72 hours, add 0.1ml of 3-glycidyl etheroxypropyl trimethoxysilane after the solution is transparent, stir for 0.2-72 hours, and let stand at room temperature to remove After soaking for 0.2-72 hours, the liquid after static degassing and PVA cross-linking was suction filtered to remove the precipitate; the same results as in Example 14 could be obtained.

Example 26

Referring to Example 14, the difference is that polyvinyl alcohol is replaced by other polymers containing hydroxyl groups in the main chain or side chains, such as one or more selected from polyethylene glycol and polyethylene glycol block copolymers. , all can obtain the same result as embodiment 14.

Example 27

Referring to Examples 1-26, the difference is that the coating of hollow silica spheres on the outside of the anti-fog layer is replaced by other substances with anti-reflection properties, such as mesoporous silica nanoparticles, and the same as in Examples can still be obtained. 1-26 with similar results.

Example 28

With reference to Examples 1-26, the difference is that the coating of the silicon dioxide hollow sphere layer on the outside of the anti-fog layer is replaced by other substances that can penetrate water, that is, an anti-fog multifunctional coating that can obtain other functions, For example, by coating high-hardness zirconia nanoparticles on the outside of the anti-fog layer, a high-strength, hard and anti-fog coating can be obtained.

Example 29

Referring to Examples 1-26, the difference is that the coating of hollow silica spheres on the outside of the anti-fog layer is replaced by an optical limiting coating, such as a C ₆₀ coating, etc., to obtain both optical limiting and anti-fogging. The coating of mist, its anti-fog effect is similar to embodiment 1-26.

Example 30

Referring to Examples 1-26, the difference is that the coating of hollow silica spheres on the outside of the anti-fog layer is replaced by a self-cleaning coating, such as a titanium dioxide coating, to obtain a self-cleaning and anti-fog coating. layer, its anti-fog effect is similar to that of Examples 1-26.

Example 31

Referring to Examples 1-26, the difference is that the coating of hollow silica spheres on the outside of the anti-fog layer is replaced by a hydrophobic coating, such as a fluorosilane coating, to obtain a coating that is both hydrophobic and anti-fog , its anti-fog effect is similar to that of Example 1-26.

Example 32

Referring to Examples 1-26, the difference is that the coating of hollow silica spheres on the outside of the anti-fog layer is replaced by an anti-glare coating, such as a TiN-SiO ₂ coating, etc., to obtain both anti-glare and anti-glare. The coating of mist, its anti-fog effect is similar to embodiment 1-26.

Apparently, the above-mentioned embodiments of the present invention are only examples for clearly illustrating the present invention, and are not intended to limit the implementation of the present invention. Those of ordinary skill in the art can also make It is impossible to exhaustively list all the implementation modes here, and any obvious changes or changes derived from the technical solutions of the present invention are still within the scope of protection of the present invention.

Claims (8)

1. A multi-functional anti-fog coating, characterized in that: said multi-functional anti-fog coating comprises at least one layer of anti-fog coating coated on the base and at least one layer of anti-fog coating coated on the anti-fog coating Functional coating; the anti-fog coating has hygroscopicity; the functional coating can allow water to permeate. 2. A kind of multifunctional anti-fog coating according to claim 1, characterized in that: said anti-fog coating is selected from the group consisting of hygroscopic polymer coatings, hygroscopic polymers cross-linked with inorganic materials Coatings, hygroscopic polymers and polymer cross-linked coatings or hygroscopic polymers mixed with inorganic materials. 3. A kind of multifunctional anti-fog coating according to claim 1, characterized in that: said functional coating is selected from coatings with anti-reflection properties, coatings with self-cleaning properties, anti-glare properties One or more of coatings, coatings with optical limiting properties and coatings with hydrophobic properties. 4. A multifunctional anti-fog coating according to claim 3, characterized in that: the coating with anti-reflection performance is a silica hollow sphere coating. 5. A kind of multi-functional anti-fog coating according to claim 4, characterized in that: said multi-functional anti-fog coating consists of a layer of anti-fog coating coated on the substrate and coated on the anti-fog coating The layer consists of two layers of silica hollow sphere coatings. 6. A multifunctional anti-fog coating according to claim 1, characterized in that: the substrate is selected from inorganic glass, polymer sheet, polymer film, organic-inorganic composite sheet, cable or aircraft shell. 7. The preparation method of a kind of multifunctional anti-fog coating as claimed in any one of claims 1-6, is characterized in that, comprises the steps: coating the substrate with at least one hygroscopic anti-fog coating; At least one layer of water-permeable functional coating is coated on the anti-fog coating to obtain a multifunctional anti-fog coating. 8. The preparation method of a multifunctional anti-fog coating according to claim 7, characterized in that, the coating method is pulling, spraying, spin coating, scraping, rolling or manual coating.