Technical research to improve weather resistance of titanium dioxide (2)

(3) silicon coating agent dosage
In SiO2 silicon coating volume, test the relationship between silicon coating volume and sample acid solubility, the test results are shown in Figure 1.from Figure 1, it can be seen that the amount of silicon coating film is inversely inversely related to acid solubility, usually, the general weather-resistant varieties require acid solubility 1.0, and the high weather-resistant varieties require 0.5. The suitable silicon coating amount is 2.5% to 3.0%.(4) Best scheme verificationthe selection of the key conditions identified above for program verification, sample acid solubility of 0.2% to 0.4%, TEM micromorphological observation (see Figure 2), sample silicon coating film continuously, completely and uniformly wrapped on the surface of titanium dioxide particles, clearly visible.2.1.5 Experimental Conclusions (1) Coating Dispersion Conditions: Alkaline Environment pH s 9 to 10, Dispersant addition 0.2% is the best;(2) acid regulator: hydrochloric acid and sulfuric acid effect is better than aluminum sulfate;
(3) silicon coating agent dosage: 2.5% to 3% best;(4) from scanning electro-mirror photos, the film layer is more uniform and dense, the coating effect is better.2.2 phosphorus, aluminum phosphorus double-layer coating 2.2.1 experimental raw materials unsophageed chlorinated R-type titanium slurry, inoromic tantalum solution, inoromic phosphate solution, inorderable aluminum salt solution and pH regulator.2.2.2 Experimental MethodTake a certain amount of unsophized chlorinated R-type titanium white slurry, fully dispersed and heated to a certain temperature, add at least 1 inoromic salt solution, use pH regulator to control pH in a certain range For coating treatment, ripe a certain time, add pH agent, control pH value in a certain range, carry out 2 coating treatment, caching a certain time, material, washing to water-soluble salt qualified, drying, air flow crushing, that is, to obtain a double-layer coating sample.
2.2.3 Performance . Determination of light resistance (E): Titanium white powder in the glycera medium, mixed with redox reactant, placed in ultraviolet light exposure, in the same time, to irradiate before and after the color difference changes to assess the stability of titanium dioxide UV light. The lower the detection value, the better the light resistance of titanium dioxide.
2.2.4 Results Discussion . (1) The aluminum phosphorus coatingchanges the aluminum salt and phosphate addition, and the aluminum phosphorus coating sample is tested for light resistance, the results are shown in Figure 3.
As can be seen from Figure 3, the amount of aluminum and phosphorus coating is 4.5% to 4.8%, 0.8% to 0.9%, and the amount of aluminum and phosphorus coating is 5%, 0.6% to 0.7%, respectively, the amount of titanium white powder is the smallest, that is, the best resistance to light.(2) the phosphorus coatingchanges the amount of zirconium and phosphate, the phosphorus coating sample for light resistance detection.can be seen from Figure 4, the amount of niobium and phosphorus coating film is controlled at 0.3%, 0.02% to 0.10%, the titanium dioxide E is the smallest, that is, good light resistance. 2.2.5 Experimental Conclusion (1) Titanium white powder single aluminum, single molyctin and single phosphorus coating can not achieve better light resistance, double-layer coating of aluminum phosphorus or zirconium phosphorus coating volume control within a certain range, can get better light resistance performance is best. (2) compared with aluminum phosphorus coating, the tantalum phosphorus envelope has better light resistance and meets the requirements of application industry. 3 product performance and foreign famous titanium dioxide brand weather-resistant products compared to the test situation can be seen in Table 4. As you can see, the performance of the two is basically the same. 4 Nodule (1) Titanium white powder coating premise is that the TiO2 particles in the titanium white slurry are fully dispersed conditions; (2) silicon coating can improve the product's weather resistance, but the different coating conditions affect the degree of edification of the silicon film, Thus affecting the weather resistance of titanium dioxide, (3) phosphorus coating technology can effectively improve the light resistance of titanium white powder (one of the main weather resistance), the addition control of niobium phosphorus is the key point of technology; (4) silicon coating and zirconium phosphorus coating can play a role in improving the weather resistance of titanium white powder, silicon coating and zirconium phosphorus coating experimental products mainly achieve similar product levels. .