Coating formulation: Study on the formulation of composite nano coating

Abstract: in order to prepare superhydrophobic nano organic coating, a new nano-SiO2 particle was added into a solvent based varnish by mechanical blending In order to further improve the hydrophobicity of the coating and solve the problems caused by nanoparticles, isopropanol, triacetin and silicone oil were added into the system The results show that the contact angle of water drop on the coating surface can reach 160 ° by adjusting the proportion of each component, and superhydrophobic is realized Key words: polish oil; nano-SiO2; contact angle; whiteness Paint agent, top 10 Chinese wall paint brands Recommended introduction: interior wall paint and exterior wall paint can achieve beautiful, clean and pleasant effects, but the effects in different environments are different, so the color of the paint will be different There are ten brands of Chinese paint, ten brands of global paint, ten brands of Chinese wall paint, and ten brands of Chinese paint, Famous trademark of Chinese paint and coating In private rooms, most of us choose according to our own personality, personal hobbies and living habits The younger generation will choose the interior wall paint with rich colors and bright colors, while the older ones will have some working experience Abstract: in order to prepare super hydrophobic nano organic coatings, a new nano-SiO2 particle was added into a solvent based varnish by mechanical blending In order to further improve the hydrophobicity of the coating and solve the problems caused by nanoparticles, isopropanol, triacetin and silicone oil were added into the system The results show that the contact angle of water drop on the coating surface can reach 160 ° by adjusting the proportion of each component, and superhydrophobic is realized Key words: polishing oil; nano-SiO2; contact angle; classification number of whiteness map: ts802.3 document identification code: a article number: 1001-3563 (2012) 23-0124-05 polishing oil is a decorative and protective functional coating used on printed matter The development of water-based varnish is a hot topic at home and abroad, and also in line with the concept of environmental protection However, solvent based varnish still plays a leading role in the market today Nano materials have been developed rapidly since 1970s In recent years, in order to solve some disadvantages of traditional coatings, such as easy to scratch, wear, loss of light, bubbles and so on, some coating workers use the unique effects of nano materials to make the coating products achieve a qualitative leap, and nano materials modified coatings came into being In recent years, the research of composite modified coatings is increasing gradually, but it is rare to use nano materials to modify varnish Because its mechanical and optical properties can not meet the required standards, it is rarely used in the packaging industry The results show that nano materials can improve the self-cleaning ability of the varnish coating and form a super hydrophobic property with "lotus leaf effect" [4-6] In this paper, nano-SiO2 particles were dispersed in the system by mechanical blending and ultrasonic dispersion In the process of research, the problem that the film is white and easy to scratch is dealt with At last, the superhydrophobic composite material with a static contact angle of 165 ° is prepared It is tested by whiteness tester and ink decolorization tester The results show that the nano composite coating with superhydrophobic has good optical and mechanical properties 1 Experiment 1.1 raw material Shangguang oil gop190, Shanghai DIC Ink Co., Ltd.; isopropanol (IPA), Shanghai sanaisi Reagent Co., Ltd.; Triacetin (glyceride), Shanghai sanaisi Reagent Co., Ltd.; silicon oil (dc245), Dow Corning (Shanghai) Co., Ltd.; SiO2 nanoparticles (r812s), Evonik Degussa (China) Investment Co., Ltd Shanghai Branch 1.2 equipment dsa100 contact angle tester, Kruss company, Germany; ag-19 ink decolorization tester, Dongguan Aigu Testing Instrument Co., Ltd.; zb-b whiteness tester, Hangzhou paper bond Automation Technology Co., Ltd.; sk1200h-j ultrasonic cleaner, Shanghai Kedao Ultrasonic Instrument Co., Ltd.; al104 electronic balance, METTLER TOLEDO instrument (Shanghai) Co., Ltd 1.3 preparation of coating at room temperature, a certain amount of Polish gop190 is dissolved in isopropanol and triacetic acid glyceride, then silicone oil is added, and finally SiO2 nanoparticles are dispersed in the system by mechanical blending and ultrasonic wave The obtained varnish is evenly coated on the sample, and then dried at room temperature to obtain the required coating 1.4 coating performance test and characterization: the contact angle of water drops on different coating surfaces is tested by contact angle tester; the wear resistance of different varnish coatings is tested by ink decolorization tester; the whiteness of different coatings is tested by whiteness tester 2 Results and analysis 2.1 effect of nano-SiO2 on coating Nano silica r812s is a kind of hydrophobic gas-phase silica with high specific surface area treated by hexamethyldisilazane (HMDS) Its particle size is up to 7Nm It can be effectively and evenly dispersed in the varnish through mechanical agitation and ultrasonic wave Because the nanoparticles have the characteristics of small particle size and large specific surface energy, it will lead to the adsorption of resins and solvents in the varnish Even other substances, first of all, will improve the viscosity of the whole varnish, which may lead to too much viscosity, resulting in the inability to meet the requirements of the Polish equipment for the viscosity of the varnish, and finally the inability to polish; secondly, the addition of nanoparticles will reduce the transparency of the coating after film formation, resulting in the decline of the appearance performance of the coating At last, the wear resistance of the coating is affected by the addition of nanoparticles 2.1.1 influence of nano particles on contact angle of coating in order to get the influence of nano particles on all aspects of coating performance after drying the varnish without considering other factors, add 3%, 5%, and 8% (mass fraction, the same later) r812s particles into gop190 varnish, and measure the contact angle after polishing The influence of nano particles on the contact angle of the coating is shown in Figure 1 It can be seen from Fig 1 that with the increase of hydrophobic nano-SiO2, the static contact angle of the coating becomes larger and larger, and the maximum contact angle does not exceed 115 ° This shows that the contact angle of the coating increases with the direct addition of nano particles, because the roughness of the coating increases due to the agglomeration of nano particles on the coating surface, but there is no greater contact angle At this time, the coating surface has not reached the formation of superhydrophobic micro nano composite structure, and no structural mutation The rolling angle is decreasing because the adhesion between water drop and coating becomes smaller and smaller with the increase of hydrophobic degree of coating 2.1.2 the influence of nano particles on the transparency of the coating After the nano particles are directly added to the Polish, the photos of the coating obtained by drying are shown in Fig 2, and the whiteness measurement results are shown in Fig 3 It can be seen from figures 2 and 3 that adding nanoparticles directly will cause the final coating to turn white, and the whitening will become more and more serious with the increase of nanoparticles The main reason for the whitening of the sample is that the boiling point of the solvent is low and the volatilization is too fast, which leads to a sharp drop in the surface temperature of the coating film, and causes the condensation of moisture, resulting in the whitening of the coating film 2.1.3 the influence of nano particles on the wear resistance of the coating is shown in Table 1 (the number of times of friction is 10) It can be seen from table 1 and Figure 2 that the wear resistance of the coating formed by directly adding nanoparticles is poor [10-11], and the more particles are added, the worse the wear resistance Easy to be scratched or poor wear resistance is due to the agglomeration of particles and floating on the surface of the coating, resulting in low strength Therefore, nano particles can not be directly added to the polishing oil 2.2 the influence of isopropanol on the coating In view of the above problems, a new formula was designed to add isopropanol to adjust the viscosity and curing time Because of the addition of isopropanol, the direct effect is that the viscosity will be greatly improved if it is increased too fast 2.2.1 the influence of isopropanol on the contact angle of the coating film is firstly in gop190 varnish, adding 5% r812s particles (the viscosity of the system is too large when it is 8%), adding isopropanol (0.5, 1, 1.5, 2 times of gop190 mass) and polishing, and measuring the contact angle after drying It can be seen from Fig 4 that the contact angle increases with the increase of the ratio of isopropanol to varnish Moreover, the static contact angle was significantly improved when isopropanol was added, while the rolling angle was significantly decreased The reason may be that the micro nano structure is formed on the surface, the surface roughness can intercept the air, and the droplets can not fill the grooves on the surface, so the super high contact angle is produced, and the rolling angle drops sharply 2.2.2 the effect of isopropanol on the transparency of the film From Figure 5, it can be seen that the addition of isopropanol does not have a great effect on the whitening of the film, and the film is still white Because the volatility of isopropanol is also high, resulting in the condensation of moisture on the film 2.2.3 the effect of isopropanol on the abrasion resistance of the coating film is shown in Table 2 (the number of times of friction is 10) It can be seen from table 2 that the dried coating is still not wear-resistant, indicating that the nanoparticles are still not evenly dispersed in the varnish, and the analysis is caused by the weak binding force According to the influence of isopropanol on all aspects of the coating, the formula of M (IPA): m (GOP) = 3:2 has better comprehensive performance, which can be used as the next starting point of the study 2.3 effect of triacetate on the coating In view of the problem that the above coating is still white, add glyceride in the previous formula to adjust the viscosity and curing time 2.3.1 the influence of glycerides on the contact angle of the coating film: firstly, add 5% r812s particles into gop190 varnish, add isopropanol (1.5 times of gop190), then add 5%, 10%, 20%, 30% glycerides, polish them, and measure the contact angle after drying It can be seen from Fig 6 that with the increase of the amount of glyceride, the static contact angle decreases and the rolling angle slightly increases, indicating that the glyceride should not be added too much, which is still affected by the surface micro rough structure 2.3.2 the influence of glycerides on the transparency of the film From Figure 7, when only 5% glycerides of triacetate are added, the whiteness of the coating reaches 2.35 At this time, the coating has become transparent, mainly because of the high boiling point of glycerides of triacetate 2.3.3 the effect of glyceride on the abrasion resistance of the coating is shown in Table 3 (the number of times of friction is 10) It can be seen from table 3 that the addition of glycerides will lead to poor wear resistance It is possible that the high boiling point of glycerides will greatly increase the possibility of residual in the coating Therefore, in the case of ensuring other good properties, try to use less triacetate Considering the influence of glyceride on all aspects of the coating, 5% glyceride is the best formula, which can be used as the next starting point of the study 2.4 effect of silicone oil on the abrasion resistance of the coating In view of the problem that the above coating is not abrasion resistant, silicone oil was added to the previous formula to increase the abrasion resistance of the coating (it is tested that silicone oil has little effect on the contact angle and whiteness) See Table 4 for the wear resistance of the coating after adding silicone oil (the number of times of friction is more than 200) It can be seen from table 4 that the wear resistance reaches the best when m (PDMS): m (SiO2) = 1:1 Because of the addition of silicon oil, nano particles and light oil are well combined, and the wear resistance of PDMS varnish silica ternary composite film is very good However, increasing the silicon oil with low surface energy may cause the excess silicon oil to be adsorbed by the solvent molecules in the varnish system