CN112794649B - Antifogging film and preparation method thereof - Google Patents

Abstract

The invention belongs to the technical field of film material preparation, and particularly relates to a preparation method of an antifogging film with excellent wear resistance, which comprises the steps of dissolving methoxysilane in water, adding acetic acid, uniformly stirring under the action of a magnetic rotor, and standing for later use; soaking the glass sheet treated by the oxygen plasma in the solution for several hours, and then drying for later use; dissolving acrylamide, bisacrylamide, a persulfate, tetramethylethylenediamine and calcium ions in water, and uniformly mixing a certain volume of the solution with polyvinyl alcohol; and (3) spin-coating a certain volume of the mixed solution on a treated substrate by using a spin coater, and drying after spin-coating. The method adopts a simple spin-coating method to prepare the antifogging film with excellent wear resistance, has the advantages of simple and easy operation process, wide application range, controllable reaction conditions, low raw material cost and the like, has no pollution to the environment, has good binding force, and does not influence the light transmittance of the original substrate material while ensuring the antifogging effect.

Description

A kind of anti-fog film and preparation method thereof

technical field

The invention belongs to the technical field of film material preparation, and particularly relates to a preparation method for coating a film on the surface of a substrate such as glass and making it have excellent wear resistance and anti-fog performance.

Background technique

People often come into contact with glass in daily life and production, such as vehicle windshields, rearview mirrors, bathroom mirrors, building windows, and solar panels. However, under certain temperature and humidity conditions, the water vapor in the air will condense together to form tiny water droplets on the surface of the glass, which is prone to fogging. Due to the existence of small water droplets, light will be refracted and reflected. In some cases, the fogging phenomenon will have a certain impact on people's life and production. For example, it will affect the sight of the vehicle driver, making it impossible to see the objects in front through the glass, thus causing serious harm to driving safety.

At present, there are two main methods to eliminate the atomization phenomenon: the first is from the perspective of thermodynamics, the small water droplets condensed into water vapor under specific conditions are evaporated in a short time through thermal energy. The second is to process the substrate surface from the chemical composition and structure of the material surface to change the chemical composition and structure of the glass surface, thereby changing the wetting state of the glass surface to achieve the effect of hydrophilic or hydrophobic anti-fog. To achieve the purpose of anti-fog by heating, it often takes a long time, and the practical performance is limited to a certain extent, and the installation of the heating device is complicated and the cost is high, which is not conducive to large-scale application. Therefore, most researchers tend to consider changing the wettability of the substrate material. This can be done from two aspects. One is to make the surface of the material hydrophilic, so that the liquid can spread quickly and evenly on the solid surface, so that water droplets can form on the surface of the material. A layer of water film, thus eliminating the phenomenon of water droplets scattering and refraction of light, to achieve anti-fog effect. On the other hand, the surface of the material is hydrophobized, the contact angle of the water drop is increased, and then it rolls down through its own gravity to achieve the anti-fog effect. However, many hydrophobic or superhydrophobic systems contain components such as silicon and fluorine, which make the material poor in adhesion, poor in firmness, and fluorine-containing compounds pollute the environment to a certain extent.

Therefore, research on wear-resistant and anti-fog films has greater prospects. For the purpose of this application, we prepared anti-fog films with certain wear-resistant properties by spin coating, which have good film-forming properties, low prices, and anti-fog properties. It is durable and does not affect the light transmittance of the original glass after coating. CN 103664004 B discloses an anti-fog coating, a preparation method of the anti-fog coating, and anti-fog glass, but the surface hydroxylation treatment methods are different, and the temperature ranges used for curing are different; The fog layer is processed in multiple steps, and the steps are cumbersome. The solvent used in the present invention is deionized water, which is more environmentally friendly; and compared with the use of a mixed solution of H ₂ O ₂ and concentrated H ₂ SO ₄ for hydroxylation, the use of oxygen plasma is safer and more effective, and the temperature range used for curing is lower. , more convenient to operate, the prepared acrylamide solution of the present invention is combined with polyvinyl alcohol to form a double network structure, which enhances the wear resistance of the film layer. CN 104086093 B discloses an anti-fog coating, a preparation method thereof, and an anti-fog glass. Compared with the present invention, the pretreatment of ordinary glass in the present invention does not require physical polishing, and the operation is simpler; Organic solvent, more environmentally friendly, and heat treatment does not require vacuum conditions, easy to operate; in addition to glass and PC boards, it can also be applied to PET, PVC boards, and has a wider range of applications.

SUMMARY OF THE INVENTION

The object of the present invention is to provide a method for preparing an anti-fog film with wear resistance, by using a spin coating method to spread the solution evenly on a glass sheet and drying to prepare a wear-resistant anti-fog film, so as to solve the problem of the complex operation process and mechanical problems of preparing the anti-fog surface. poor performance issues. The prepared anti-fog film layer has no pollution to the environment, no poison, and has the advantages of lasting anti-fog performance, good wear resistance and the like.

To achieve the above object, the present invention adopts the following technical solutions:

A preparation method of an anti-fog film with wear resistance, the specific steps are as follows:

(1) Prepare a certain concentration of precursor solution

First dissolve a certain mass of methoxysilane in water, then add a small amount of acetic acid, stir evenly under the action of a magnetic rotor, and let it stand for later use;

(2) Soak and dry

Soak the base sheet in the mixed solution prepared in step (1) for several hours, then place it in an oven to dry, and store it at room temperature for later use;

(3) Preparation of solution

Dissolve a certain quality of acrylamide, bisacrylamide, persulfide, tetramethylethylenediamine, calcium ions in water, and take a certain volume to mix with polyvinyl alcohol evenly;

(4) Spin coat and dry

A certain volume of the above mixed solution is spin-coated on the treated substrate sheet with a glue homogenizer, and taken out to dry after spin-coating, thereby obtaining an anti-fog film layer with excellent wear resistance.

Further, the specific steps of preparing a certain concentration of the precursor solution in step (1) include weighing 0.1-5 g of methoxysilane and dissolving it in 100 mL of water, then measuring 5-40 μL of acetic acid, and magnetically stirring for 3-12 hours. until completely dissolved.

Further, the substrate sheet in step (2) is any one of glass, PC, PET, PVC, preferably an oxygen plasma-treated glass sheet, wherein the specific steps include using oxygen plasma at -101.4kPa Processing 1 ~ 10min.

Further, in the step (2), the base sheet is soaked in the mixed solution prepared in the step (1) for 1-8 hours.

Further, the specific steps of step (3) are: first add calcium ions, acrylamide, water, then add bisacrylamide, tetramethylethylenediamine, and finally add persulfide while stirring under ice bath conditions; ultrasonication after configuration After uniform dispersion, the mixed solution is uniformly mixed with 1 wt % to 15 wt % of polyvinyl alcohol according to a volume ratio of 1:1 to 8:1. The specific raw material quality of step (3) is: 1-10 g of acrylamide, 1-10 mg of bis-acrylamide, 2-12 mg of persulfide, 1-15 g of calcium ions, and 5-30 μL of tetramethylethylenediamine.

Further, the rotational speed of the spin coating described in the step (4) is 500-2500 r/min, and the spin-coating time is 5-20 s.

Further, the drying temperature range in step (4) is 50-100°C.

Further, the drying time described in step (4) is 1-20h.

Methoxysilanes generate silanes in an acidic aqueous environment. These hydrogen bonds between the oxides on the glass surface and the silanes become chemically stable siloxane bonds after removal of water, with acrylamide as the monomer and bis-acrylamide as the crosslinker The persulfide is used as the initiator, and the tetramethylethylenediamine is used as the reducing agent to form a redox system with the persulfide, which can initiate polymerization at a lower temperature. The long-chain polymer network of polyacrylamide is covalently cross-linked to silanes on various solid modified surfaces, and then forms a double network structure by interacting with polyvinyl alcohol, thereby improving the wear resistance of the film.

The invention adopts acrylamide monomer to form an interactive network structure through the action of a cross-linking agent, an initiator, a reducing agent, etc., and the prepared film layer has a hydrophilic group amino group, which can quickly remove water molecules in the air. Adsorbed into the coating, the water vapor does not condense into small water droplets on the surface of the substrate, but forms a uniform water film. This eliminates the fogging phenomenon caused by the refraction and diffuse reflection of the transmitted light due to the different curvature radii of the small water droplets, thereby achieving the purpose of anti-fogging.

The advantages of the present invention are:

(1) The solution is uniformly spread on the substrate sheet by spin coating and dried to prepare a wear-resistant anti-fog film. The preparation process is simple, the operation is convenient, and the prepared anti-fog film has good wear resistance. The light transmittance test results show that the substrate is glass The anti-fog coating has little effect on the light transmittance of the glass, and the coated glass can still maintain a light transmittance of about 90%, which solves the problems of complicated preparation process, long time consumption and poor stability in many traditional methods.

(2) The raw materials used in this method are environmentally friendly and non-polluting, the coating film can be placed for a long time after drying, and the water vapor is absorbed by the film layer to play an anti-fog effect.

(3) This method can also coat anti-fog coatings on other substrates according to actual needs, such as PC, PVC, PET materials, etc., which can achieve a good anti-fog effect without affecting the original light transmittance of the material. .

Description of drawings

Fig. 1 is a UV spectrum diagram (a), an optical picture (b) and an anti-fogging effect picture (c) on different substrates of an anti-fog film with wear resistance of the present invention;

Fig. 2 is a kind of anti-fog film surface with wear-resisting property of the present invention different mass loads and tape peeling times (a), sandpaper rubbing times (b) and anti-fog effect picture display;

3 is a surface topography diagram (a) of an anti-fog film with wear resistance of the present invention, the inserted picture is a contact angle display, and a cross-sectional view display (b);

FIG. 4 is a display of the lasting performance of an anti-fog film with wear resistance of the present invention.

Detailed ways

The invention provides a preparation method of an anti-fog film with wear resistance, comprising the following steps:

(1) Prepare a certain concentration of precursor solution

(2) Soak and dry

(3) Preparation of solution

(4) Spin coat and dry

In order to make the above objects, features and advantages of the present invention more clearly understood, the present invention will be described in further detail below with reference to specific embodiments.

Step 1: Prepare a certain concentration of precursor solution

In one embodiment, this step can be specifically performed as follows: first, place the glass sheet in a beaker and sonicate for 15 min with acetone, absolute ethanol and deionized water, respectively, and put it into a 60°C oven to dry after the sonication, and cool it for later use. Dissolve a certain mass of methoxysilane in water, add a small amount of acetic acid, stir evenly under the action of a magnetic rotor, and let it stand for later use;

Step 2: Soak and Dry

In one embodiment, this step can be specifically performed as follows: soak the glass sheet treated with oxygen plasma in the mixed solution prepared in step 1 for several hours, then place it in an oven to dry, and store it at room temperature for future use.

Step 3: Prepare the solution

In one embodiment, this step can be specifically performed as follows: a certain mass of acrylamide, bisacrylamide, persulfide, tetramethylethylenediamine, and calcium ions are dissolved in water, and a certain volume is mixed with polyvinyl alcohol. evenly.

Step Four: Spin Coat and Dry

In one embodiment, this step can be specifically performed as follows: take a certain volume of the above mixed solution and spin-coat it on the treated glass sheet with a glue homogenizer, and take it out for drying after spin-coating, so as to obtain excellent wear resistance. anti-fog glass.

Please refer to FIG. 1 . FIG. 1 is a transparent picture display and an anti-fogging picture of an anti-fog film with wear resistance of the present invention. As shown in (a) in Figure 1, the prepared anti-fog glass has good transparency, and the light transmittance is about 90% compared with ordinary glass, indicating that the coated film will not affect the light transmittance of the glass; As shown in (b) in Figure 1, the prepared mixed solution can be coated on different substrates, such as PVC, PC, PET, etc., with good transparency; as shown in (c) in Figure 1, The films prepared on different substrates have a certain anti-fogging effect. Compared with the blank substrates, tiny water droplets cannot be formed on the surface of the prepared films under the action of water vapor, which can be clearly observed through the glass layer. The text at the bottom of the beaker has a good anti-fog effect.

Please refer to FIG. 2, (a) in FIG. 2 is a graph showing the relationship between the surface of the prepared film layer and the peeling times of the tape by using weights of different masses to load an anti-fog film with wear resistance of the present invention. When the load is 2kg After 160 times of tape peeling, it still has anti-fog effect; (b) in FIG. 2 is an anti-fog film with wear resistance of the present invention, which is loaded with weights of different masses in the preparation of the film. The relationship between the surface of the layer and the number of times of sandpaper friction, when a weight of 500g is loaded, after 160 times of sandpaper friction, the film layer still has a certain anti-fog effect.

Please refer to FIG. 3 , which is a topography and a cross-sectional picture of the surface of an anti-fog film with wear resistance according to the present invention. As shown in (a) of FIG. 3 , agglomeration of lumps appears in a small area of the prepared anti-fog surface, and the overall upper surface is relatively smooth. According to the inserted picture, the water contact angle of the coating surface is 78.9°±0.9°; as shown in (b) in Figure 3, the thickness of the prepared anti-fog film layer is 7.9±0.4 μm.

Please refer to FIG. 4 , which is an anti-fog picture of an anti-fog film with wear resistance of the present invention. As shown in Figure 4, the prepared coated glass can continue to be anti-fogging after being placed for 366 days, indicating that the anti-fogging glass prepared by this method has good durability.

In order to make the above objects, features and advantages of the present invention more obvious and easy to understand, the technical solutions of the present invention are further described below with reference to the embodiments. However, the present invention is not limited to the listed embodiments, but also includes any other known modifications within the scope of the claimed rights of the present invention.

Example 1

This embodiment prepares an anti-fog film with wear resistance according to the following steps:

Step 1. Prepare a certain concentration of precursor solution

The glass pieces were placed in a beaker and subjected to acetone, anhydrous ethanol, and deionized water for 15 min in sequence. Dissolve 0.1 g of methoxysilane in water, add 5 μL of acetic acid, stir for 4 h under the action of a magnetic rotor, and let stand for later use;

Step 2: Soak and Dry

The cleaned glass sheet was treated with oxygen plasma for 1.0 min, then soaked in the mixed solution prepared in step 1 for 1 hour, then dried in an oven, and stored at room temperature for future use.

Step 3: Prepare the solution

Weigh 2.1g of acrylamide, 1.2mg of bis-acrylamide, 3.3mg of persulfide, and 2g of calcium ions, dissolved in water, and then weighed out 5μL of tetramethylethylenediamine. Mix evenly, and the volume ratio of acrylamide mixed solution and polyvinyl alcohol solution is 1:1.

Step Four: Spin Coat and Dry

The mixed solution prepared in step 3 was spin-coated on the glass sheet, the spin-coating speed was 500 r/min, the spin-coating time was 3 s, and then dried in an oven at 60° C. for 1 h.

Embodiment 2

This embodiment prepares an anti-fog film with wear resistance according to the following steps:

Step 1. Prepare a certain concentration of precursor solution

The glass pieces were placed in a beaker and subjected to acetone, anhydrous ethanol, and deionized water for 15 min in sequence. Dissolve 0.2 g of methoxysilane in water, add 10 μL of acetic acid, stir for 5 h under the action of a magnetic rotor, and let stand for later use;

Step 2: Soak and Dry

The cleaned glass sheet was treated with oxygen plasma for 2.0 min, then soaked in the mixed solution prepared in step 1 for 2 hours, then dried in an oven, and stored at room temperature for future use.

Step 3: Prepare the solution

Weigh 3.2g of acrylamide, 2.3mg of bis-acrylamide, 6mg of persulfide, and 5g of calcium ions, dissolved in water, and then weighed out 10 μL of tetramethylethylenediamine. Mix evenly, and the volume ratio of acrylamide mixed solution and polyvinyl alcohol solution is 2:1.

Step Four: Spin Coat and Dry

The mixed solution prepared in step 3 was spin-coated on the glass sheet, the spin-coating speed was 1000 r/min, the spin-coating time was 10 s, and then dried in an oven at 90° C. for 2 h.

Embodiment 3

This embodiment prepares an anti-fog film with wear resistance according to the following steps:

Step 1. Prepare a certain concentration of precursor solution

The glass pieces were placed in a beaker and subjected to acetone, anhydrous ethanol, and deionized water for 15 min in sequence. Dissolve 1 g of methoxysilane in water, add 15 μL of acetic acid, stir for 6 h under the action of a magnetic rotor, and let stand for later use;

Step 2: Soak and Dry

The cleaned glass sheet was subjected to oxygen plasma treatment for 4.0 min, then soaked in the mixed solution prepared in step 1 for 3 hours, then dried in an oven, and stored at room temperature for future use.

Step 3: Prepare the solution

Weigh 4.1g of acrylamide, 3.5mg of bis-acrylamide, 5mg of persulfide, and 4g of calcium ions, dissolved in water, and then weighed out 14μL of tetramethylethylenediamine. After ultrasonically dispersed uniformly, take a certain volume and mix it with 3wt% polyvinyl alcohol. Evenly, the volume ratio of acrylamide mixed solution and polyvinyl alcohol solution is 3:1.

Step Four: Spin Coat and Dry

The mixed solution prepared in step 3 was spin-coated on the glass sheet, the spin-coating speed was 700 r/min, the spin-coating time was 5 s, and then dried in an oven at 80° C. for 3 h.

Embodiment 4

This embodiment prepares an anti-fog film with wear resistance according to the following steps:

Step 1. Prepare a certain concentration of precursor solution

The glass pieces were placed in a beaker and subjected to acetone, anhydrous ethanol, and deionized water for 15 min in sequence. Dissolve 3 g of methoxysilane in water, add 20 μL of acetic acid, stir for 7 h under the action of a magnetic rotor, and let stand for later use;

Step 2: Soak and Dry

The cleaned glass sheet was subjected to oxygen plasma treatment for 5.0 min, then soaked in the mixed solution prepared in step 1 for 4 hours, then dried in an oven, and stored at room temperature for future use.

Step 3: Prepare the solution

Weigh 4.5g of acrylamide, 6mg of bisacrylamide, 7mg of persulfide, and 5g of calcium ions, dissolved in water, and then weighed out 8μL of tetramethylethylenediamine. After ultrasonically dispersing evenly, take a certain volume and mix it with 4wt% polyvinyl alcohol. , the volume ratio of acrylamide mixed solution and polyvinyl alcohol solution is 4:1.

Step Four: Spin Coat and Dry

The mixed solution prepared in step 3 was spin-coated on the glass sheet, the spin-coating speed was 800 r/min, the spin-coating time was 10 s, and then placed in an oven at 95° C. to dry for 4 h.

Embodiment 5

This embodiment prepares an anti-fog film with wear resistance according to the following steps:

Step 1. Prepare a certain concentration of precursor solution

The glass pieces were placed in a beaker and subjected to acetone, anhydrous ethanol, and deionized water for 15 min in sequence. Dissolve 2 g of methoxysilane in water, add 20 μL of acetic acid, stir for 7 h under the action of a magnetic rotor, and let stand for later use;

Step 2: Soak and Dry

The cleaned glass sheet was subjected to oxygen plasma treatment for 5.0 min, then soaked in the mixed solution prepared in step 1 for 4 hours, then dried in an oven, and stored at room temperature for future use.

Step 3: Prepare the solution

Weigh 5.7g of acrylamide, 9.2mg of bisacrylamide, 7mg of persulfide, and 5g of calcium ions, dissolved in water, and then weighed out 8 μL of tetramethylethylenediamine. After ultrasonically dispersed uniformly, take a certain volume and mix it with 4wt% polyvinyl alcohol. Evenly, the volume ratio of acrylamide mixed solution and polyvinyl alcohol solution is 6:1.

Step Four: Spin Coat and Dry

The mixed solution prepared in step 3 was spin-coated on the glass sheet, the spin-coating speed was 1000 r/min, the spin-coating time was 20 s, and then dried in an oven at 100° C. for 5 h.

In summary, the present invention discloses a method for preparing an anti-fog film with wear resistance, which uses a spin coating method to rapidly spread droplets on the glass surface. The reaction conditions are mild, and the light transmittance is up to 90%, which does not affect the light transmittance of the original glass. After peeling off with tape and rubbing with sandpaper for a certain number of times, it still has anti-fog effect. It can be placed at room temperature for about a year without pollution to the environment. , has a good application prospect, and is expected to be well used in windshields, rearview mirrors and mirrors in bathrooms in automobiles.

It should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and not to limit them. Although the present invention has been described in detail with reference to the preferred embodiments, those of ordinary skill in the art should understand that the technical solutions of the present invention can be Modifications or equivalent replacements should all be included in the scope of the claims of the present invention.

Claims (8)

1. a preparation method of anti-fog film, is characterized in that, the method comprises the steps: (1) Prepare the precursor solution First dissolve methoxysilane in water, then add acetic acid, stir evenly under the action of a magnetic rotor, and let stand for later use; (2) Soak and dry Soak the base sheet in the mixed solution prepared in step (1), then place it in an oven to dry, and store it at room temperature for future use; (3) Prepare the solution Dissolve acrylamide, bisacrylamide, persulfide, tetramethylethylenediamine and calcium ions in water, and take a certain volume and mix with polyvinyl alcohol evenly; (4) Spin coat and dry The above mixed solution is spin-coated on the treated substrate sheet with a glue homogenizer, and after the spin-coating is finished, it is taken out and dried, thereby obtaining an anti-fog film layer with excellent wear resistance; The specific steps of step (3) are as follows: firstly add calcium ions, acrylamide and water, then add bisacrylamide and tetramethylethylenediamine, and finally add persulfide while stirring under ice bath conditions; The mixed solution is uniformly mixed with 1 wt% to 15 wt% polyvinyl alcohol according to the volume ratio of 1:1 to 8:1; Step (3) The specific raw material quality is: 1-10 g acrylamide, 1-10 mg bisacrylamide, 2-12 mg persulfide, 1-15 g calcium ion, 5-30 μL tetramethylethylenediamine. 2. The method for preparing an anti-fog film according to claim 1, wherein step (1) specifically comprises weighing 0.1-5 g of methoxysilane dissolved in 100 mL of water, and then measuring 5-40 μL of acetic acid , and magnetically stirred for 3-12 h until completely dissolved. 3 . The method for preparing an anti-fog film according to claim 1 , wherein the base sheet in step (2) is any one of glass, PC, PET, and PVC. 4 . 4 . The method for preparing an anti-fogging film according to claim 3 , wherein the substrate sheet in step (2) is a glass sheet treated with oxygen plasma. 5 . 5. The method for preparing an anti-fogging film according to claim 1, wherein the base sheet in step (2) is soaked in the mixed solution prepared in step (1) for 1-8 hours. 6. The method for preparing an anti-fogging film according to claim 1, wherein in step (4), the spin coating speed is 500-2500 r/min, and the spin-coating time is 5-20 s. 7 . The method for preparing an anti-fogging film according to claim 1 , wherein the drying temperature in step (4) ranges from 50°C to 100°C. 8 . 8 . The method for preparing an anti-fog film according to claim 1 , wherein the drying time in step (4) is 1-20 h. 9 .

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