An anti-glare coating for AG glass and a preparation process thereof

Abstract

The present application relates to the technical field of anti-dazzle coating, in particular to an anti-dazzle coating for AG glass and a preparation process thereof, comprising: (1) blending water-based polyurethane emulsion, modified nano microparticles, defoaming agent and leveling agent, and then high-speed dispersing for 30-50 min; (2) standing for more than 30 min to remove bubbles, and then anti-dazzle coating is prepared. In the present application, a polymer is coated on the surface of nano TiO2 to form a core-shell structure, nano TiO2 microspheres are prepared, and then pretreated nano SiO2 is attached to the surface of the microspheres to form a three-layer structure. The prepared modified nano microparticles can be well compatible with the matrix and form a stacking structure, thereby reducing light reflection and producing diffuse reflection. In addition, the irregular morphology of the outermost nano SiO2 can further reduce light reflection, and the anti-dazzle effect of the coating is improved.

Description

Technical Field

[0001] This invention relates to the field of anti-glare coating technology, specifically to an anti-glare coating for AG glass and its preparation process. Background Technology

[0002] The characteristic of AG glass is that it turns the reflective surface of the glass into a matte diffuse reflective surface, thereby achieving the effect of anti-glare. This is usually achieved by coating the glass surface with an anti-glare coating.

[0003] Patent application CN201910756551.3 discloses an anti-glare protective film and its preparation method, which uses hollow glass microspheres as the core to form core-shell structured microspheres as anti-glare additives; patent application CN202010205729.8 discloses a method for preparing a nanocomposite particle modified anti-glare film layer, which uses poly(styrene-co-acrylate) porous microspheres as anti-glare additives; however, the aforementioned core-shell two-layer structured anti-glare additives have insufficient light scattering, thus affecting the anti-glare performance of the coating. Therefore, we provide an anti-glare coating for AG glass and its preparation process. Summary of the Invention

[0004] To address the shortcomings of existing technologies, this invention provides an anti-glare coating for AG glass and its preparation process. A three-layer structure is formed by attaching pretreated nano-SiO2 to the surface of nano-TiO2 microspheres, which improves the anti-glare effect of the coating.

[0005] To achieve the above objectives, the present invention provides the following technical solution: an anti-glare coating for AG glass, comprising the following raw materials by mass percentage: 70-80% waterborne polyurethane emulsion, 10-25% modified nanoparticles, 0.5-2% defoamer, and 0.5-1.5% leveling agent.

[0006] Preferably, the defoamers include, but are not limited to, BYK-019, BYK-021 and BYK-024; the leveling agents include, but are not limited to, BYK-361N, BYK-359 and BYK-356.

[0007] Preferably, the modified nanoparticles are prepared as follows:

[0008] S1. Surface modification of nano-TiO2 was performed using a silane coupling agent to obtain organosilicon-modified nano-TiO2;

[0009] S2. Organosilicon-modified nano-TiO2 is ultrasonically dispersed in deionized water, followed by the addition of sodium dodecyl sulfate and n-pentanol. The mixture is stirred and emulsified at 70-85℃ for 0.5-1h to obtain an emulsion.

[0010] S3. Add methyl methacrylate and ammonium persulfate to the emulsion, react for 1-2 hours, then add pretreated nano-SiO2, stir and react for 0.5-1 hours to obtain the slurry;

[0011] S4. Adjust the pH of the slurry to 7-8 with ammonia water, then filter, wash, dry, and grind it to obtain modified nanoparticles.

[0012] Preferably, in step S1, the preparation of organosilicon-modified nano-TiO2 is as follows: silane coupling agent KH-560 is dissolved in 50wt% ethanol solution at a material-to-liquid ratio of 1:30g / ml, nano-TiO2 is added to it, and after reacting for 1-2 hours, it is filtered, washed, and dried to obtain organosilicon-modified nano-TiO2.

[0013] Preferably, in step S2, the ratio of organosilicon-modified nano-TiO2 to deionized water is 1:150 g / ml; the mass ratio of organosilicon-modified nano-TiO2, sodium dodecyl sulfate, and n-pentanol is 1:7:2.

[0014] Preferably, in steps S2 to S3, the mass ratio of ammonium persulfate, organosilicon-modified nano-TiO2, pretreated nano-SiO2, and methyl methacrylate is 1:6:6:100.

[0015] Preferably, in step S3, the preparation of pretreated nano-SiO2 is specifically as follows: nano-SiO2 is placed in a 5wt% hydrofluoric acid solution for etching for 5-10 minutes, filtered and dried, and then modified with silane coupling agent KH-560 to obtain pretreated nano-SiO2.

[0016] This invention provides a preparation process for an anti-glare coating for AG glass, comprising the following steps:

[0017] (1) After mixing the waterborne polyurethane emulsion, modified nanoparticles, defoamer and leveling agent, disperse them at high speed for 30-50 minutes;

[0018] (2) Let it stand for more than 30 minutes to de-foam and obtain the anti-glare coating.

[0019] This invention provides an anti-glare coating for AG glass and its preparation process, which has the following advantages compared with the prior art:

[0020] This invention involves coating a polymer onto the surface of nano-TiO2 to form a core-shell structure, thereby producing nano-TiO2 microspheres. Then, pretreated nano-SiO2 is attached to the surface of the microspheres to form a three-layer structure. The resulting modified nanoparticles can be well compatible with the substrate and form a stacked structure, thereby reducing light reflection and producing diffuse reflection. Furthermore, the irregular morphology of the outermost nano-SiO2 can further reduce light reflection, improving the anti-glare effect of the coating.

[0021] This invention etches the surface of nano-SiO2, increasing its surface area to facilitate the adhesion of silane coupling agents, and forms a large number of pits on the surface of nano-SiO2. This uneven structure allows light to be scattered multiple times, reducing its reflectivity, thereby further improving the anti-glare performance of the coating. Detailed Implementation

[0022] The following embodiments are provided to illustrate the implementation of this application in detail, so that the process of how this application uses technical means to solve technical problems and achieve technical effects can be fully understood and implemented accordingly.

[0023] The aqueous polyurethane emulsions used in the following examples and comparative examples are prepared in the following specific ways:

[0024] 60 parts by mass of polyether diol and 30 parts by mass of toluene diisocyanate were added to a reactor and reacted at 70°C for 0.5 h. Then, 8 parts by mass of 1,4-butanediol were added to the reactor and reacted at 80°C for 1 h, followed by cooling to 50°C. Next, 20 parts by mass of acetone were added to the reactor, and triethylamine was added to adjust the pH to 4. The reaction was carried out for 2 h to generate a prepolymer. The prepolymer was dispersed and emulsified with deionized water, and then acetone was removed by vacuum distillation to obtain an aqueous polyurethane emulsion. The amount of deionized water added accounted for 60% of the total mass of the prepolymer.

[0025] Example 1

[0026] An anti-glare coating for AG glass comprises the following raw materials by weight percentage: 73% waterborne polyurethane emulsion, 25% modified nanoparticles, 0.5% defoamer BYK-019, and 1.5% leveling agent BYK-361N.

[0027] The preparation process of the anti-glare coating for AG glass is as follows: (1) mix water-based polyurethane emulsion, modified nanoparticles, defoamer and leveling agent and disperse at high speed for 30 min; (2) let stand for 30 min to defoam and obtain the anti-glare coating.

[0028] The modified nanoparticles were prepared as follows:

[0029] S1. Surface modification of nano-TiO2 is performed using a silane coupling agent to obtain organosilicon-modified nano-TiO2. The preparation of organosilicon-modified nano-TiO2 is as follows: Silane coupling agent KH-560 is dissolved in a 50wt% ethanol solution at a material-to-liquid ratio of 1:30 g / ml, nano-TiO2 is added to the solution, and after reacting for 1 hour, it is filtered, washed, and dried to obtain organosilicon-modified nano-TiO2.

[0030] S2. Organosilicon-modified nano-TiO2 was ultrasonically dispersed in deionized water, followed by the addition of sodium dodecyl sulfate and n-pentanol. The mixture was stirred and emulsified at 70°C for 1 hour to obtain an emulsion. The ratio of organosilicon-modified nano-TiO2 to deionized water was 1:150 g / ml. The mass ratio of organosilicon-modified nano-TiO2, sodium dodecyl sulfate, and n-pentanol was 1:7:2.

[0031] S3. Add methyl methacrylate and ammonium persulfate to the emulsion, react for 2 hours, then add pretreated nano-SiO2 and stir for 1 hour to obtain a slurry. The mass ratio of ammonium persulfate, organosilicon-modified nano-TiO2, pretreated nano-SiO2, and methyl methacrylate is 1:6:6:100. The pretreated nano-SiO2 is prepared as follows: nano-SiO2 is etched in a 5wt% hydrofluoric acid solution for 5 minutes, filtered, dried, and then modified with a silane coupling agent KH-560 (the modification method is the same as the organosilicon modification method for nano-TiO2) to obtain pretreated nano-SiO2.

[0032] S4. Adjust the pH of the slurry to 7 with ammonia water, then filter, wash, dry, and grind it to obtain modified nanoparticles.

[0033] Example 2

[0034] An anti-glare coating for AG glass comprises the following raw materials by weight percentage: 80% waterborne polyurethane emulsion, 18% modified nanoparticles, 11% defoamer BYK-02, and 91% leveling agent BYK-35.

[0035] The preparation process of the anti-glare coating for AG glass is as follows: (1) mix water-based polyurethane emulsion, modified nanoparticles, defoamer and leveling agent and disperse at high speed for 40 min; (2) let stand for 40 min to defoam and obtain the anti-glare coating.

[0036] The modified nanoparticles were prepared as follows:

[0037] S1. Surface modification of nano-TiO2 is performed using a silane coupling agent to obtain organosilicon-modified nano-TiO2. The preparation of organosilicon-modified nano-TiO2 is as follows: Silane coupling agent KH-560 is dissolved in a 50wt% ethanol solution at a material-to-liquid ratio of 1:30 g / ml, nano-TiO2 is added to the solution, and after reacting for 1.5 h, it is filtered, washed, and dried to obtain organosilicon-modified nano-TiO2.

[0038] S2. Organosilicon-modified nano-TiO2 was ultrasonically dispersed in deionized water, followed by the addition of sodium dodecyl sulfate and n-pentanol. The mixture was stirred and emulsified at 80°C for 0.7 h to obtain an emulsion. The ratio of organosilicon-modified nano-TiO2 to deionized water was 1:150 g / ml. The mass ratio of organosilicon-modified nano-TiO2, sodium dodecyl sulfate, and n-pentanol was 1:7:2.

[0039] S3. Add methyl methacrylate and ammonium persulfate to the emulsion, react for 1.5 h, then add pretreated nano-SiO2 and stir for 0.6 h to obtain a slurry; the mass ratio of ammonium persulfate, organosilicon-modified nano-TiO2, pretreated nano-SiO2 and methyl methacrylate is 1:6:6:100. The preparation of pretreated nano-SiO2 is as follows: nano-SiO2 is etched in a 5 wt% hydrofluoric acid solution for 7 min, filtered and dried, and then modified with silane coupling agent KH-560 (the modification method is the same as the organosilicon modification method for nano-TiO2) to obtain pretreated nano-SiO2.

[0040] S4. Adjust the pH of the slurry to 7.5 with ammonia water, then filter, wash, dry, and grind it to obtain modified nanoparticles.

[0041] Example 3

[0042] An anti-glare coating for AG glass comprises the following raw materials by weight percentage: 76% waterborne polyurethane emulsion, 20.5% modified nanoparticles, 2% defoamer BYK-024, and 1.5% leveling agent BYK-356.

[0043] The preparation process of the anti-glare coating for AG glass is as follows: (1) mix water-based polyurethane emulsion, modified nanoparticles, defoamer and leveling agent and disperse at high speed for 50 min; (2) let stand for more than 60 min to defoam and obtain the anti-glare coating.

[0044] The modified nanoparticles were prepared as follows:

[0045] S1. Surface modification of nano-TiO2 is performed using a silane coupling agent to obtain organosilicon-modified nano-TiO2. The preparation of organosilicon-modified nano-TiO2 is as follows: Silane coupling agent KH-560 is dissolved in a 50wt% ethanol solution at a material-to-liquid ratio of 1:30 g / ml, nano-TiO2 is added to the solution, and after reacting for 2 hours, it is filtered, washed, and dried to obtain organosilicon-modified nano-TiO2.

[0046] S2. Organosilicon-modified nano-TiO2 was ultrasonically dispersed in deionized water, followed by the addition of sodium dodecyl sulfate and n-pentanol. The mixture was stirred and emulsified at 85°C for 0.5 h to obtain an emulsion. The ratio of organosilicon-modified nano-TiO2 to deionized water was 1:150 g / ml. The mass ratio of organosilicon-modified nano-TiO2, sodium dodecyl sulfate, and n-pentanol was 1:7:2.

[0047] S3. Add methyl methacrylate and ammonium persulfate to the emulsion, react for 2 hours, then add pretreated nano-SiO2 and stir for 1 hour to obtain a slurry. The mass ratio of ammonium persulfate, organosilicon-modified nano-TiO2, pretreated nano-SiO2, and methyl methacrylate is 1:6:6:100. The preparation of pretreated nano-SiO2 is as follows: nano-SiO2 is etched in a 5 wt% hydrofluoric acid solution for 10 minutes, filtered, dried, and then modified with silane coupling agent KH-560 (the modification method is the same as the organosilicon modification method for nano-TiO2) to obtain pretreated nano-SiO2.

[0048] S4. Adjust the pH of the slurry to 8 with ammonia water, then filter, wash, dry, and grind it to obtain modified nanoparticles.

[0049] Comparative Example 1

[0050] The process is largely the same as in Example 2, except that the modified nanoparticles are prepared as follows:

[0051] S1. Surface modification of nano-TiO2 is performed using a silane coupling agent to obtain organosilicon-modified nano-TiO2. The preparation of organosilicon-modified nano-TiO2 is as follows: Silane coupling agent KH-560 is dissolved in a 50wt% ethanol solution at a material-to-liquid ratio of 1:30 g / ml, nano-TiO2 is added to the solution, and after reacting for 1.5 h, it is filtered, washed, and dried to obtain organosilicon-modified nano-TiO2.

[0052] S2. Organosilicon-modified nano-TiO2 was ultrasonically dispersed in deionized water, followed by the addition of sodium dodecyl sulfate and n-pentanol. The mixture was stirred and emulsified at 80°C for 0.7 h to obtain an emulsion. The ratio of organosilicon-modified nano-TiO2 to deionized water was 1:150 g / ml. The mass ratio of organosilicon-modified nano-TiO2, sodium dodecyl sulfate, and n-pentanol was 1:7:2.

[0053] S3. Add methyl methacrylate and ammonium persulfate to the emulsion and stir for 0.6 h to obtain a slurry; the mass ratio of ammonium persulfate, organosilicon-modified nano-TiO2 and methyl methacrylate is 1:6:100.

[0054] S4. Adjust the pH of the slurry to 7.5 with ammonia water, then filter, wash, dry, and grind it to obtain modified nanoparticles.

[0055] Comparative Example 2

[0056] The process is largely the same as in Example 2, except that the modified nanoparticles are prepared as follows:

[0057] S1. Surface modification of nano-TiO2 is performed using a silane coupling agent to obtain organosilicon-modified nano-TiO2. The preparation of organosilicon-modified nano-TiO2 is as follows: Silane coupling agent KH-560 is dissolved in a 50wt% ethanol solution at a material-to-liquid ratio of 1:30 g / ml, nano-TiO2 is added to the solution, and after reacting for 1.5 h, it is filtered, washed, and dried to obtain organosilicon-modified nano-TiO2.

[0058] S2. Organosilicon-modified nano-TiO2 was ultrasonically dispersed in deionized water, followed by the addition of sodium dodecyl sulfate and n-pentanol. The mixture was stirred and emulsified at 80°C for 0.7 h to obtain an emulsion. The ratio of organosilicon-modified nano-TiO2 to deionized water was 1:150 g / ml. The mass ratio of organosilicon-modified nano-TiO2, sodium dodecyl sulfate, and n-pentanol was 1:7:2.

[0059] S3. Add methyl methacrylate and ammonium persulfate to the emulsion, react for 1.5 h, then add organosilicon-modified nano-SiO2, stir and react for 0.6 h to obtain a slurry; the mass ratio of ammonium persulfate, organosilicon-modified nano-TiO2, organosilicon-modified nano-SiO2 and methyl methacrylate is 1:6:6:100. The method for organosilicon-modified nano-SiO2 is the same as the method for organosilicon-modified nano-TiO2.

[0060] S4. Adjust the pH of the slurry to 7.5 with ammonia water, then filter, wash, dry, and grind it to obtain modified nanoparticles.

[0061] Comparative Example 3

[0062] The process is largely the same as in Example 2, except that the modified nanoparticles are prepared as follows:

[0063] S1. Surface modification of nano-SiO2 is performed using a silane coupling agent to obtain organosilicon-modified nano-SiO2. The preparation of organosilicon-modified nano-SiO2 is as follows: Silane coupling agent KH-560 is dissolved in a 50wt% ethanol solution at a material-to-liquid ratio of 1:30 g / ml, nano-SiO2 is added to the solution, and after reacting for 1.5 h, it is filtered, washed, and dried to obtain organosilicon-modified nano-SiO2.

[0064] S2. Organosilicon-modified nano-SiO2 was ultrasonically dispersed in deionized water, followed by the addition of sodium dodecyl sulfate and n-pentanol. The mixture was stirred and emulsified at 80°C for 0.7 h to obtain an emulsion. The ratio of organosilicon-modified nano-SiO2 to deionized water was 1:150 g / ml. The mass ratio of organosilicon-modified nano-SiO2, sodium dodecyl sulfate, and n-pentanol was 1:7:2.

[0065] S3. Add methyl methacrylate and ammonium persulfate to the emulsion and stir for 0.6 h to obtain a slurry; the mass ratio of ammonium persulfate, organosilicon-modified nano-SiO2 and methyl methacrylate is 1:6:100.

[0066] S4. Adjust the pH of the slurry to 7.5 with ammonia water, then filter, wash, dry, and grind it to obtain modified nanoparticles.

[0067] Quality Inspection

[0068] 1. The anti-glare coatings described in Examples 1-3 and Comparative Examples 1-3 were sprayed onto transparent substrates to form multiple 10μm thick coatings. The 60° gloss and light transmittance of each coating were tested. The specific results are shown in the table below.

[0069] Table 1. Gloss and transmittance of the anti-glare coating

[0070] category 60° gloss Light transmittance (%) Example 1 20.1 89.7 Example 2 18.2 91.3 Example 3 19.4 91.5 Comparative Example 1 26.4 90.6 Comparative Example 2 21.4 91.1 Comparative Example 3 25.8 90.2

[0071] As can be seen from the table above:

[0072] (1) Compared with Comparative Example 2, the coating in Example 2 has a lower gloss and a higher light transmittance, indicating that the anti-glare coating in Example 2 has a better anti-glare effect. This shows that etching the surface of nano-SiO2 can form more pits on its surface, which helps to disperse light and thus obtain a better anti-glare effect.

[0073] (2) Compared with Comparative Example 1 and Comparative Example 3, the anti-glare effect of the coating in Example 2 is significantly better, indicating that the effect of anti-glare coating made by using nano SiO2 microspheres or nano TiO2 microspheres alone is relatively average.

[0074] 2. The anti-glare coatings from Examples 1-3 and Comparative Examples 1-3 were sprayed onto the substrate to form multiple 30μm thick coatings, resulting in multiple coating samples. The abrasion was measured using a JM-3 coating abrasion meter, with the load controlled at 1×10⁻⁶. 4 N, starting at 100 revolutions. The formula for calculating abrasion resistance is as follows: Abrasion resistance = (mass of the coated sample before wear - mass of the coated sample before wear) / coating thickness. The specific results are shown in the table below.

[0075] Table 2 Abrasion resistance of anti-glare coating

[0076] category Abrasion resistance (mg / μm) Example 1 2.3 Example 2 2.5 Example 3 2.6 Comparative Example 1 4.4 Comparative Example 2 2.5 Comparative Example 3 4.8

[0077] As can be seen from the table above, compared with Comparative Example 1 and Comparative Example 3, the anti-glare coatings in Examples 1-3 have significantly better wear resistance, indicating that attaching pretreated nano-SiO2 to the surface of nano-TiO2 microspheres can significantly improve the wear resistance of the coating.

[0078] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. An anti-glare coating for AG glass, characterized in that, The raw materials include the following percentages by weight: 70-80% waterborne polyurethane emulsion, 10-25% modified nanoparticles, 0.5-2% defoamer, and 0.5-1.5% leveling agent; The modified nanoparticles were prepared as follows: S1. Surface modification of nano-TiO2 was performed using a silane coupling agent to obtain organosilicon-modified nano-TiO2; S2. Organosilicon-modified nano-TiO2 is ultrasonically dispersed in deionized water, followed by the addition of sodium dodecyl sulfate and n-pentanol. The mixture is stirred and emulsified at 70-85℃ for 0.5-1h to obtain an emulsion. S3. Add methyl methacrylate and ammonium persulfate to the emulsion, react for 1-2 hours, then add pretreated nano-SiO2, stir and react for 0.5-1 hours to obtain the slurry; The preparation of pretreated nano-SiO2 is as follows: nano-SiO2 is placed in a 5wt% hydrofluoric acid solution for etching for 5-10 min, filtered and dried, and then modified with silane coupling agent KH-560 to obtain pretreated nano-SiO2. S4. Adjust the pH of the slurry to 7-8 with ammonia water, then filter, wash, dry, and grind it to obtain modified nanoparticles.

2. The anti-glare coating for AG glass according to claim 1, characterized in that, Defoamers include, but are not limited to, BYK-019, BYK-021 and BYK-024; leveling agents include, but are not limited to, BYK-361N, BYK-359 and BYK-356.

3. The anti-glare coating for AG glass according to claim 1, characterized in that, In step S1, the preparation of organosilicon-modified nano-TiO2 is as follows: silane coupling agent KH-560 is dissolved in 50wt% ethanol solution at a material-to-liquid ratio of 1:30g / ml, nano-TiO2 is added to it, and after reacting for 1-2 hours, it is filtered, washed and dried to obtain organosilicon-modified nano-TiO2.

4. The anti-glare coating for AG glass according to claim 1, characterized in that, In step S2, the ratio of organosilicon-modified nano-TiO2 to deionized water is 1:150 g / ml; the mass ratio of organosilicon-modified nano-TiO2, sodium dodecyl sulfate, and n-pentanol is 1:7:

2.

5. The anti-glare coating for AG glass according to claim 1, characterized in that, In steps S2 to S3, the mass ratio of ammonium persulfate, organosilicon-modified nano-TiO2, pretreated nano-SiO2, and methyl methacrylate is 1:6:6:

100.

6. The preparation process of an anti-glare coating for AG glass according to any one of claims 1-5, characterized in that, Includes the following steps: (1) After mixing the waterborne polyurethane emulsion, modified nanoparticles, defoamer and leveling agent, disperse them at high speed for 30-50 min; (2) Let it stand for more than 30 minutes to remove bubbles and obtain the anti-glare coating.