Modification method of nanoscale titanium dioxide

Abstract

The invention discloses a modification method of nanoscale titanium dioxide. The preparation method comprises the following steps: carrying out pre-improvement treatment on nano titanium dioxide to obtain pre-improved nano titanium dioxide; the preparation method comprises the following steps: blending the pre-improved nano titanium dioxide and a ball milling agent according to a weight ratio of (5-7): 3, carrying out ball milling treatment, and carrying out suction filtration and drying after ball milling is finished. According to the modification method of the nano titanium dioxide, the nano titanium dioxide is subjected to pre-improvement treatment, an additive B in a modifier and a modified solution A are blended, blended and optimized, raw materials in a reconditioning agent are mutually matched and blended, a quartz solution is optimized and improved, and then a prepared ball milling agent is further matched with the modified additive in a system; and the performance effect of the product is further enhanced.

Description

Technical Field

[0001] The invention relates to the technical field of titanium dioxide modification, and in particular to a method for modifying nano-grade titanium dioxide. Background Art

[0002] Nano-grade titanium dioxide, with its nanometer-scale particle size (typically 1-100 nm), exhibits distinctly superior properties compared to conventional titanium dioxide. It also exhibits unique advantages in electrical and mechanical properties, offering new possibilities for the development of electronic devices and high-performance composite materials. However, existing nano-grade titanium dioxide is prone to agglomeration, resulting in uneven dispersion in the application system, which in turn affects product performance. Based on this, the present invention further modifies and optimizes this nano-grade titanium dioxide. Summary of the Invention

[0003] In view of the defects of the prior art, the purpose of the present invention is to provide a method for modifying nano-grade titanium dioxide to solve the problems raised in the above background technology.

[0004] The present invention solves the technical problem by adopting the following technical solutions: The present invention provides a method for modifying nano-grade titanium dioxide, comprising the following steps: Step 1: pre-processing the nano titanium dioxide to obtain pre-modified nano titanium dioxide; The specific pre-improvement methods are: a: Preheat the nano titanium dioxide at 135-145℃ for 1h, then heat it to 230-240℃ at a rate of 2-5℃ / min, keep it warm for 20min, and finally cool it to 55℃ at a rate of 1-3℃ / min and keep it warm; b: uniformly blending the heat-insulated nano titanium dioxide, the modified additive and the sodium lignin sulfonate solution in a weight ratio of (4-5):2:(5-8) to obtain pre-modified nano titanium dioxide; Step 2: Mix the pre-improved nano titanium dioxide and the ball milling agent in a weight ratio of (5-7):3 and perform ball milling. After the ball milling is completed, filter and dry.

[0005] Preferably, the ball milling speed of the blended ball milling treatment is 1000-1500 r / min, and the ball milling is 2 hours; the mass fraction of the sodium lignin sulfonate solution is 5-8%.

[0006] Preferably, the preparation method of the modified additive is: S01: Aluminum borate whiskers are first stirred evenly in a sufficient amount of 5% by mass potassium permanganate solution, then washed with water, filtered, and dried. The dried aluminum borate whiskers are preheated at 55-60°C for 1 hour to obtain a preheated whisker agent; S02: The preheated whisker agent and modifier are ultrasonically modified in a weight ratio of 3:5. After the treatment is completed, the mixture is filtered and dried to obtain a modified additive.

[0007] Preferably, the ultrasonic modification treatment is performed at an ultrasonic power of 350-400W and for 1 hour.

[0008] Preferably, the preparation method of the modifier is: S02a: Add 3-5 parts of carbon nanotubes, 2-4 parts of bismuth titanate, and 1-3 parts of kaolin to 5-8 parts of sodium silicate solution and stir evenly to obtain modified solution A; S02b: 2-3 parts of lignocellulose, 4-6 parts of boron nitride and 5-8 parts of lanthanum nitrate solution are mixed and stirred uniformly to obtain additive B; additive B and modified liquid A are stirred thoroughly in a weight ratio of 3:5 to obtain a modifier.

[0009] Preferably, the mass fraction of the sodium silicate solution is 5-8%; the mass fraction of the lanthanum nitrate solution is 2-5%.

[0010] Preferably, the preparation method of the ball mill is: S11: Stir the quartz in a sufficient amount of 5% by mass hydrogen peroxide solution, then wash with water, filter and dry; Dry quartz, yttrium oxide and sodium hexametaphosphate solution are uniformly mixed in a weight ratio of (3-5):2:(5-8) to obtain a quartz solution; S12: 3-5 parts of zirconium oxide, 2-4 parts of hydrotalcite, and 1-3 parts of silicon carbide fiber are blended and added to 5-8 parts of barium nitrate solution for primary ball milling. After the ball milling is completed, the mixture is filtered and dried to obtain a compounding agent; The compounding agent and the quartz liquid are mixed in a weight ratio of 4:7 and subjected to ball milling treatment, and the ball milling treatment is completed at the end of the secondary ball milling to obtain the ball milling agent.

[0011] Preferably, the mass fraction of the sodium hexametaphosphate solution is 5-8%; the mass fraction of the barium nitrate solution is 2-5%.

[0012] Preferably, the first-stage ball milling treatment has a ball milling speed of 750-850 r / min and the ball milling is carried out for 2 hours; the second-stage ball milling treatment has a ball milling speed of 1200-1500 r / min and the ball milling is carried out for 1 hour.

[0013] Compared with the prior art, the present invention has the following beneficial effects: The modification method of the nano-grade titanium dioxide of the present invention adopts the method of pre-improvement treatment of the nano-titanium dioxide, wherein the nano-titanium dioxide is first subjected to a step-by-step heating and cooling method to optimize the activity efficiency of the nano-titanium dioxide, and then the modified additive and sodium lignin sulfonate solution are blended and dispersed for improvement, the aluminum borate whiskers in the modified additive are activated and improved by a potassium permanganate solution, and then preheated to stimulate their activity, and then ultrasonically improved by the modifier, the B additive in the modifier and the modified A liquid are blended and optimized, the B additive adopts wood cellulose, boron nitride and lanthanum nitrate solution to blend and coordinate, and the boron nitride sheet structure is matched with the wood cellulose and lanthanum nitrate solution through the co-coordination between the raw materials, and the modified A liquid is coordinated through the blending and coordination between the raw materials, and the modified A liquid is based on carbon nanotubes with high specific surface area, and the carbon nanotubes are supported and coordinated. Kaolin, bismuth titanate, and sodium silicate solution are blended at the same time, and the kaolin is loaded into the carbon nanotubes through the lamellae, and then combined with bismuth titanate and sodium silicate solution to obtain a modifier that can better optimize the dispersion and stability of nano titanium dioxide, improve the application of titanium dioxide in solar cell silver paste, improve the product's photoelectric conversion efficiency and adhesion performance, and optimize the corrosion resistance and weathering stability of titanium dioxide. At the same time, the quartz in the ball mill is activated and optimized by hydrogen peroxide solution, and then blended and dispersed with yttrium oxide and sodium hexametaphosphate solution. The composite agent ball milling improved quartz liquid obtained by the first-level ball milling of zirconium oxide, hydrotalcite, silicon carbide fiber and barium nitrate solution is used. The raw materials in the composite agent are coordinated and blended with each other to optimize and improve the quartz liquid, and the ball mill prepared is further coordinated with the modified additive in the system to further enhance the performance of the product. DETAILED DESCRIPTION

[0014] The following is a clear and complete description of the technical solutions in the embodiments of the present invention in conjunction with specific embodiments. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0015] A method for modifying nano-grade titanium dioxide of this embodiment includes the following steps: Step 1: pre-processing the nano titanium dioxide to obtain pre-modified nano titanium dioxide; The specific pre-improvement methods are: a: Preheat the nano titanium dioxide at 135-145℃ for 1h, then heat it to 230-240℃ at a rate of 2-5℃ / min, keep it warm for 20min, and finally cool it to 55℃ at a rate of 1-3℃ / min and keep it warm; b: uniformly blending the heat-insulated nano titanium dioxide, the modified additive and the sodium lignin sulfonate solution in a weight ratio of (4-5):2:(5-8) to obtain pre-modified nano titanium dioxide; Step 2: Mix the pre-improved nano titanium dioxide and the ball milling agent in a weight ratio of (5-7):3 and perform ball milling. After the ball milling is completed, filter and dry.

[0016] In the blended ball milling treatment of this embodiment, the ball milling speed is 1000-1500 r / min, and the ball milling is performed for 2 h; the mass fraction of the sodium lignin sulfonate solution is 5-8%.

[0017] The preparation method of the modified additive of this embodiment is: S01: Aluminum borate whiskers are first stirred evenly in a sufficient amount of 5% by mass potassium permanganate solution, then washed with water, filtered, and dried. The dried aluminum borate whiskers are preheated at 55-60°C for 1 hour to obtain a preheated whisker agent; S02: The preheated whisker agent and modifier are ultrasonically modified in a weight ratio of 3:5. After the treatment is completed, the mixture is filtered and dried to obtain a modified additive.

[0018] The ultrasonic modification treatment in this embodiment was performed at an ultrasonic power of 350-400 W and for 1 hour.

[0019] The preparation method of the modifier of this embodiment is: S02a: Add 3-5 parts of carbon nanotubes, 2-4 parts of bismuth titanate, and 1-3 parts of kaolin to 5-8 parts of sodium silicate solution and stir evenly to obtain modified solution A; S02b: 2-3 parts of lignocellulose, 4-6 parts of boron nitride and 5-8 parts of lanthanum nitrate solution are mixed and stirred uniformly to obtain additive B; additive B and modified liquid A are stirred thoroughly in a weight ratio of 3:5 to obtain a modifier.

[0020] The mass fraction of the sodium silicate solution in this embodiment is 5-8%; the mass fraction of the lanthanum nitrate solution is 2-5%.

[0021] The preparation method of the ball mill of this embodiment is: S11: Stir the quartz in a sufficient amount of 5% by mass hydrogen peroxide solution, then wash with water, filter and dry; Dry quartz, yttrium oxide and sodium hexametaphosphate solution are uniformly mixed in a weight ratio of (3-5):2:(5-8) to obtain a quartz solution; S12: 3-5 parts of zirconium oxide, 2-4 parts of hydrotalcite, and 1-3 parts of silicon carbide fiber are blended and added to 5-8 parts of barium nitrate solution for primary ball milling. After the ball milling is completed, the mixture is filtered and dried to obtain a compounding agent; The compounding agent and the quartz liquid are mixed in a weight ratio of 4:7 and subjected to ball milling treatment, and the ball milling treatment is completed at the end of the secondary ball milling to obtain the ball milling agent.

[0022] The mass fraction of the sodium hexametaphosphate solution in this embodiment is 5-8%; the mass fraction of the barium nitrate solution is 2-5%.

[0023] In this embodiment, the first-stage ball milling treatment has a ball milling speed of 750-850 r / min and the ball milling is carried out for 2 hours; the second-stage ball milling treatment has a ball milling speed of 1200-1500 r / min and the ball milling is carried out for 1 hour.

[0024] Example 1. A method for modifying nano-grade titanium dioxide of this embodiment includes the following steps: Step 1: pre-processing the nano titanium dioxide to obtain pre-modified nano titanium dioxide; The specific pre-improvement methods are: a: Preheat the nano-titanium dioxide at 135°C for 1 hour, then heat it to 230°C at a rate of 2°C / min, keep it warm for 20 minutes, and finally cool it to 55°C at a rate of 1°C / min and keep it warm; b: The heat-insulated nano titanium dioxide, the modified additive and the sodium lignin sulfonate solution are uniformly blended in a weight ratio of 4:2:5 to obtain a pre-modified nano titanium dioxide; Step 2: Mix the pre-improved nano titanium dioxide and the ball milling agent in a weight ratio of 5:3 and perform ball milling. After the ball milling is completed, filter and dry.

[0025] The ball milling speed of the blended ball milling treatment in this embodiment is 1000 r / min, and the ball milling is 2 h; the mass fraction of the sodium lignin sulfonate solution is 5%.

[0026] The preparation method of the modified additive of this embodiment is: S01: Aluminum borate whiskers were first stirred evenly in a sufficient amount of 5% by mass potassium permanganate solution, then washed with water, filtered, and dried. The dried aluminum borate whiskers were preheated at 55°C for 1 hour to obtain a preheated whisker agent. S02: The preheated whisker agent and modifier are ultrasonically modified in a weight ratio of 3:5. After the treatment is completed, the mixture is filtered and dried to obtain a modified additive.

[0027] The ultrasonic modification treatment in this embodiment was performed at an ultrasonic power of 350 W and for 1 hour.

[0028] The preparation method of the modifier of this embodiment is: S02a: Add 3 parts of carbon nanotubes, 2 parts of bismuth titanate and 1 part of kaolin to 5 parts of sodium silicate solution and stir evenly to obtain modified solution A; S02b: 2 parts of lignocellulose, 4 parts of boron nitride and 5 parts of lanthanum nitrate solution are mixed and stirred uniformly to obtain additive B; additive B and modified liquid A are stirred thoroughly in a weight ratio of 3:5 to obtain a modifier.

[0029] The mass fraction of the sodium silicate solution in this embodiment is 5%; the mass fraction of the lanthanum nitrate solution is 2%.

[0030] The preparation method of the ball mill of this embodiment is: S11: Stir the quartz in a sufficient amount of 5% by mass hydrogen peroxide solution, then wash with water, filter and dry; The dried quartz, yttrium oxide and sodium hexametaphosphate solution are uniformly mixed in a weight ratio of 3:2:5 to obtain a quartz solution; S12: 3 parts of zirconium oxide, 2 parts of hydrotalcite, and 1 part of silicon carbide fiber are blended and added to 5 parts of barium nitrate solution for primary ball milling. After the ball milling is completed, the mixture is filtered and dried to obtain a compounding agent; The compounding agent and the quartz liquid are mixed in a weight ratio of 4:7 and subjected to ball milling treatment, and the ball milling treatment is completed at the end of the secondary ball milling to obtain the ball milling agent.

[0031] The mass fraction of the sodium hexametaphosphate solution in this embodiment is 5%; the mass fraction of the barium nitrate solution is 2%.

[0032] In this embodiment, the ball milling speed of the first-stage ball milling treatment is 750 r / min, and the ball milling is carried out for 2 h; the ball milling speed of the second-stage ball milling treatment is 1200 r / min, and the ball milling is carried out for 1 h.

[0033] Example 2. A method for modifying nano-grade titanium dioxide of this embodiment includes the following steps: Step 1: pre-processing the nano titanium dioxide to obtain pre-modified nano titanium dioxide; The specific pre-improvement methods are: a: Preheat the nano-titanium dioxide at 145°C for 1 hour, then heat it to 240°C at a rate of 5°C / min, keep it warm for 20 minutes, and finally cool it to 55°C at a rate of 3°C / min and keep it warm; b: The heat-insulated nano titanium dioxide, the modified additive and the sodium lignin sulfonate solution are uniformly blended in a weight ratio of 5:2:8 to obtain pre-modified nano titanium dioxide; Step 2: The pre-improved nano titanium dioxide and the ball milling agent are mixed and ball milled in a weight ratio of 7:3. After the ball milling is completed, the mixture is filtered and dried.

[0034] The ball milling speed of the blended ball milling treatment in this embodiment is 1500 r / min, and the ball milling is 2 h; the mass fraction of the sodium lignin sulfonate solution is 8%.

[0035] The preparation method of the modified additive of this embodiment is: S01: Aluminum borate whiskers were first stirred evenly in a sufficient amount of 5% by mass potassium permanganate solution, then washed with water, filtered, and dried. The dried aluminum borate whiskers were preheated at 60°C for 1 hour to obtain a preheated whisker agent. S02: The preheated whisker agent and modifier are ultrasonically modified in a weight ratio of 3:5. After the treatment is completed, the mixture is filtered and dried to obtain a modified additive.

[0036] The ultrasonic modification treatment in this embodiment was performed at an ultrasonic power of 400 W and for 1 hour.

[0037] The preparation method of the modifier of this embodiment is: S02a: Add 5 parts of carbon nanotubes, 4 parts of bismuth titanate and 3 parts of kaolin to 8 parts of sodium silicate solution and stir evenly to obtain modified solution A; S02b: 3 parts of lignocellulose, 6 parts of boron nitride and 8 parts of lanthanum nitrate solution are mixed and stirred uniformly to obtain additive B; additive B and modified liquid A are stirred thoroughly in a weight ratio of 3:5 to obtain a modifier.

[0038] The mass fraction of the sodium silicate solution in this embodiment is 8%; the mass fraction of the lanthanum nitrate solution is 5%.

[0039] The preparation method of the ball mill of this embodiment is: S11: Stir the quartz in a sufficient amount of 5% by mass hydrogen peroxide solution, then wash with water, filter and dry; The dried quartz, yttrium oxide and sodium hexametaphosphate solution were uniformly mixed in a weight ratio of 5:2:8 to obtain a quartz solution; S12: 5 parts of zirconium oxide, 4 parts of hydrotalcite, and 3 parts of silicon carbide fibers are blended and added to 8 parts of barium nitrate solution for primary ball milling. After the ball milling is completed, the mixture is filtered and dried to obtain a compounding agent; The compounding agent and the quartz liquid are mixed in a weight ratio of 4:7 and subjected to ball milling treatment, and the ball milling treatment is completed at the end of the secondary ball milling to obtain the ball milling agent.

[0040] The mass fraction of the sodium hexametaphosphate solution in this embodiment is 8%; the mass fraction of the barium nitrate solution is 5%.

[0041] In this embodiment, the ball milling speed of the first-stage ball milling treatment is 850 r / min, and the ball milling is carried out for 2 hours; the ball milling speed of the second-stage ball milling treatment is 1500 r / min, and the ball milling is carried out for 1 hour.

[0042] Example 3. A method for modifying nano-grade titanium dioxide of this embodiment includes the following steps: Step 1: pre-processing the nano titanium dioxide to obtain pre-modified nano titanium dioxide; The specific pre-improvement methods are: a: Preheat the nano-titanium dioxide at 140°C for 1 hour, then heat it to 235°C at a rate of 3.5°C / min, keep it warm for 20 minutes, and finally cool it to 55°C at a rate of 2°C / min and keep it warm; b: uniformly blending the heat-insulated nano titanium dioxide, the modified additive and the sodium lignin sulfonate solution in a weight ratio of 4.5:2:6.5 to obtain pre-modified nano titanium dioxide; Step 2: The pre-improved nano titanium dioxide and the ball milling agent are mixed and ball milled in a weight ratio of 6:3. After the ball milling is completed, the mixture is filtered and dried.

[0043] In the blending ball milling treatment of this embodiment, the ball milling speed was 1250 r / min, and the ball milling was performed for 2 h; the mass fraction of the sodium lignin sulfonate solution was 6.5%.

[0044] The preparation method of the modified additive of this embodiment is: S01: Aluminum borate whiskers were first stirred evenly in a sufficient amount of 5% by mass potassium permanganate solution, then washed with water, filtered, and dried. The dried aluminum borate whiskers were preheated at 57.5°C for 1 hour to obtain a preheated whisker agent. S02: The preheated whisker agent and modifier are ultrasonically modified in a weight ratio of 3:5. After the treatment is completed, the mixture is filtered and dried to obtain a modified additive.

[0045] The ultrasonic modification treatment in this embodiment was performed at an ultrasonic power of 375 W and for 1 h.

[0046] The preparation method of the modifier of this embodiment is: S02a: Add 4 parts of carbon nanotubes, 3 parts of bismuth titanate and 2 parts of kaolin to 6.5 parts of sodium silicate solution and stir evenly to obtain modified solution A; S02b: 2.5 parts of lignocellulose, 5 parts of boron nitride and 6.5 parts of lanthanum nitrate solution are mixed and stirred uniformly to obtain additive B; additive B and modified liquid A are stirred thoroughly in a weight ratio of 3:5 to obtain a modifier.

[0047] The mass fraction of the sodium silicate solution in this embodiment is 6.5%; the mass fraction of the lanthanum nitrate solution is 3.5%.

[0048] The preparation method of the ball mill of this embodiment is: S11: Stir the quartz in a sufficient amount of 5% by mass hydrogen peroxide solution, then wash with water, filter and dry; The dried quartz, yttrium oxide and sodium hexametaphosphate solution were uniformly mixed in a weight ratio of 4:2:6.5 to obtain a quartz solution; S12: 4 parts of zirconium oxide, 3 parts of hydrotalcite, and 2 parts of silicon carbide fiber are blended and added to 6.5 parts of barium nitrate solution for primary ball milling. After the ball milling is completed, the mixture is filtered and dried to obtain a compounding agent; The compounding agent and the quartz liquid are mixed in a weight ratio of 4:7 and subjected to ball milling treatment, and the ball milling treatment is completed at the end of the secondary ball milling to obtain the ball milling agent.

[0049] The mass fraction of the sodium hexametaphosphate solution in this embodiment is 6.5%; the mass fraction of the barium nitrate solution is 3.5%.

[0050] In this embodiment, the ball milling speed of the first-stage ball milling treatment is 800 r / min, and the ball milling is carried out for 2 hours; the ball milling speed of the second-stage ball milling treatment is 1350 r / min, and the ball milling is carried out for 1 hour.

[0051] Comparative Example 1. The difference from Example 3 is that no modifying additive is added.

[0052] Comparative Example 2. The difference from Example 3 is that no modifier is added to the modification additive.

[0053] Comparative Example 3. The difference from Example 3 is that no B additive is added to the modifier.

[0054] Comparative Example 4. The difference from Example 3 is that no lignocellulose or boron nitride is added to the additive B.

[0055] Comparative Example 5. The difference from Example 3 is that modified liquid A is not added to the modifier.

[0056] Comparative Example 6. The difference from Example 3 is that no carbon nanotubes or bismuth titanate are added to the modified solution A.

[0057] Comparative Example 7. The difference from Example 3 is that kaolin is not added to the modified solution A and the sodium silicate solution is replaced by water.

[0058] Comparative Example 8. The difference from Example 3 is that no ball milling agent treatment was used.

[0059] Comparative Example 9. The difference from Example 3 is that no counteracting agent is added to the ball mill.

[0060] Comparative Example 10. The difference from Example 3 is that no zirconium oxide or hydrotalcite is added to the compounding agent.

[0061] Comparative Example 11. The difference from Example 3 is that silicon carbide fiber is not added to the compounding agent and water is used instead of the barium nitrate solution.

[0062] Comparative Example 12. The difference from Example 3 is that no quartz liquid is added to the ball mill.

[0063] Comparative Example 13. The difference from Example 3 is that no dry quartz or yttrium oxide is added to the quartz solution.

[0064] The performance effects of Examples 1-3 and Comparative Examples 1-13 were tested (75 parts by weight of silver powder, 2 parts of glass powder, and 12 parts of solvent, as well as 5 parts of resin and 8 parts of the products prepared in Examples 1-3 and Comparative Examples 1-13 were blended to form a silver paste, wherein the resins were acrylic resin and polyamide wax, and the mass ratio of acrylic resin to polyamide wax was 3.5:1.0; the organic solvents were terpineol, isooctyl alcohol, and diethylene glycol butyl ether acetate, and the mass ratio of terpineol, isooctyl alcohol, and diethylene glycol butyl ether acetate was 7:1:2 to form the silver paste). The adhesion and photoelectric conversion efficiency of the silver paste under normal conditions were tested. At the same time, the corrosion resistance and weathering stability of the nano titanium dioxide product were tested (the nano titanium dioxide product to be tested was placed in 5% hydrochloric acid mist for 24 hours, and then placed under ultraviolet intensity of 500W / m The nano titanium dioxide under corrosion resistance and weather resistance conditions was irradiated for 1 hour, the above is one cycle, and the cycle was repeated 10 times). The nano titanium dioxide under corrosion resistance and weather resistance conditions was tested with reference to the silver paste under normal conditions. The test results are as follows; It can be seen from Comparative Examples 1 to 13 and Examples 1 to 3 that; The application of the nano titanium dioxide of Example 3 in silver paste can significantly improve the performance of the silver paste product. The silver paste has excellent photoelectric conversion efficiency and excellent adhesion performance. The adhesion and photoelectric conversion efficiency of the silver paste can achieve a coordinated improvement effect. In addition, the nano titanium dioxide still has excellent performance stability under acid corrosion and weathering conditions, providing excellent performance effects for the silver paste. From Comparative Examples 1 to 13 and Example 3, it can be seen that the performance of the silver paste is significantly deteriorated when the present invention does not add a modifying additive or does not use a ball milling agent treatment. The performance effect of the silver paste is most obvious when the two are combined. From Comparative Examples 2 to 7 and Example 3, it can be seen that no modifier is added to the modified additive, no B additive is added to the modifier, no lignocellulose and boron nitride are added to the B additive, no modified A liquid is added to the modifier, no carbon nanotubes and bismuth titanate are added to the modified A liquid, no kaolin is added to the modified A liquid, and the sodium silicate solution is replaced by water. The performance of the products all tends to deteriorate to varying degrees. The performance effect of the silver paste is the most significant when the modified A liquid and the B additive are jointly prepared using the specific method of the present invention. The performance effect of the silver paste is the most significant when the modifier is obtained using the specific method of the present invention. It can be seen from Comparative Examples 8 to 13 and Example 3 that no compounding agent was added to the ball mill, no zirconium oxide or hydrotalcite was added to the compounding agent, no silicon carbide fiber was added to the compounding agent, and the barium nitrate solution was replaced by water, no quartz liquid was added to the ball mill, and no dry quartz or yttrium oxide was added to the quartz liquid. The performance of the products all showed a trend of deterioration to varying degrees. The ball mill prepared by combining the compounding agent obtained by the specific method of the present invention with the quartz liquid had the most significant performance effect of the silver paste, and the preparation of the compounding agent and quartz liquid of the present invention was unique, and the technical solution of the present invention had the most significant effect.

[0065] It will be apparent to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above and that the invention can be embodied in other specific forms without departing from the spirit or essential characteristics of the invention. Therefore, the embodiments should be considered in all respects as illustrative and non-restrictive, and the scope of the invention is defined by the appended claims rather than the foregoing description, and it is intended that all variations that come within the meaning and range of equivalents of the claims be embraced therein.

[0066] In addition, it should be understood that although this specification is described in terms of implementation methods, not every implementation method contains only one independent technical solution. This narrative method of the specification is only for the sake of clarity. Those skilled in the art should regard the specification as a whole. The technical solutions in each embodiment can also be appropriately combined to form other implementation methods that can be understood by those skilled in the art.

Claims

1. A method for modifying nano-grade titanium dioxide, characterized in that: The following steps are included: Step 1: pre-processing the nano titanium dioxide to obtain pre-modified nano titanium dioxide; The specific pre-improvement methods are: a: Preheat the nano titanium dioxide at 135-145℃ for 1h, then heat it to 230-240℃ at a rate of 2-5℃ / min, keep it warm for 20min, and finally cool it to 55℃ at a rate of 1-3℃ / min and keep it warm; b: uniformly blending the heat-insulated nano titanium dioxide, the modified additive and the sodium lignin sulfonate solution in a weight ratio of (4-5):2:(5-8) to obtain pre-modified nano titanium dioxide; Step 2: Mix the pre-improved nano titanium dioxide and the ball milling agent in a weight ratio of (5-7):3 and perform ball milling. After the ball milling is completed, filter and dry.

2. The method for modifying nano-grade titanium dioxide according to claim 1, wherein: The ball milling speed of the blended ball milling treatment is 1000-1500 r / min, and the ball milling is performed for 2 hours; the mass fraction of the sodium lignin sulfonate solution is 5-8%.

3. The method for modifying nano-grade titanium dioxide according to claim 1, wherein: The preparation method of the modified additive is: S01: Aluminum borate whiskers are first stirred evenly in a sufficient amount of 5% by mass potassium permanganate solution, then washed with water, filtered, and dried. The dried aluminum borate whiskers are preheated at 55-60°C for 1 hour to obtain a preheated whisker agent; S02: The preheated whisker agent and modifier are ultrasonically modified in a weight ratio of 3:

5. After the treatment is completed, the mixture is filtered and dried to obtain a modified additive.

4. The method for modifying nano-grade titanium dioxide according to claim 3, characterized in that: The ultrasonic modification treatment is performed at an ultrasonic power of 350-400W and the ultrasonic treatment is performed for 1 hour.

5. The method for modifying nano-grade titanium dioxide according to claim 3, characterized in that: The preparation method of the modifier is: S02a: Add 3-5 parts of carbon nanotubes, 2-4 parts of bismuth titanate and 1-3 parts of kaolin to 5-8 parts of sodium silicate solution and stir evenly to obtain modified solution A; S02b: 2-3 parts of lignocellulose, 4-6 parts of boron nitride and 5-8 parts of lanthanum nitrate solution are mixed and stirred uniformly to obtain additive B; additive B and modified liquid A are stirred thoroughly in a weight ratio of 3:5 to obtain a modifier.

6. The method for modifying nano-grade titanium dioxide according to claim 5, characterized in that: The mass fraction of the sodium silicate solution is 5-8%; the mass fraction of the lanthanum nitrate solution is 2-5%.

7. The method for modifying nano-grade titanium dioxide according to claim 1, characterized in that: The preparation method of the ball mill is as follows: S11: Stir the quartz in a sufficient amount of 5% by mass hydrogen peroxide solution, then wash with water, filter and dry; Dry quartz, yttrium oxide and sodium hexametaphosphate solution are uniformly mixed in a weight ratio of (3-5):2:(5-8) to obtain a quartz solution; S12: 3-5 parts of zirconium oxide, 2-4 parts of hydrotalcite, and 1-3 parts of silicon carbide fiber are blended and added to 5-8 parts of barium nitrate solution for primary ball milling. After the ball milling is completed, the mixture is filtered and dried to obtain a compounding agent; The compounding agent and the quartz liquid are mixed in a weight ratio of 4:7 and subjected to ball milling treatment, and the ball milling treatment is completed at the end of the secondary ball milling to obtain the ball milling agent.

8. The method for modifying nano-grade titanium dioxide according to claim 7, characterized in that: The mass fraction of the sodium hexametaphosphate solution is 5-8%; the mass fraction of the barium nitrate solution is 2-5%.

9. The method for modifying nano-grade titanium dioxide according to claim 7, characterized in that: The first-stage ball milling treatment has a ball milling speed of 750-850 r / min and the ball milling is carried out for 2 hours; the second-stage ball milling treatment has a ball milling speed of 1200-1500 r / min and the ball milling is carried out for 1 hour.

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