An inorganic coating method for making materials more stable

Abstract

The present invention belongs to the technical field of titanium dioxide coating, and specifically, relates to a method for preparing an inorganic coating that makes a material more stable. During the process of inorganic coating of titanium dioxide, the stirring speed of the titanium dioxide slurry is adjusted in real time according to the following formula (1): Y=0.0046X+35.857, wherein X is the real-time viscosity of the titanium dioxide slurry, and its unit is mPa.s; Y is the stirring speed, and its unit is r / min. The beneficial effects of the present invention are: 1. The coating process is more stable, and the coating amount and coating effect of each link can be tested and monitored; if there are coating defects and coating accidents, they can be adjusted in time. 2. The pH of the coating process material and the pH of the finished product are made more stable. 3. The application performance of the finished product is made more excellent, such as 20-degree gloss, hiding power; linseed oil dispersibility, water-based high stirring, abrasion value and other properties are all improved.

Description

Technical Field

[0001] The invention belongs to the technical field of titanium dioxide coating, and in particular relates to a method for preparing an inorganic coating that makes a material more stable. Background Art

[0002] Paints composed of titanium dioxide pigments are prone to yellowing, powdering, and film stripping under ultraviolet irradiation, thus affecting its industrial application. Therefore, it is necessary to perform surface modification on titanium dioxide, including inorganic and organic modification. Among them, inorganic modification includes inorganic coating using zirconium, silicon, aluminum oxides, etc. The dense photo-inert oxide film layer can effectively prevent photogenerated electrons from transitioning to the surface of the material, thereby inhibiting the occurrence of photocatalytic reactions and making it have better weather resistance. Then the existing inorganic coating process has the following defects: During the inorganic coating process, the viscosity of the titanium dioxide slurry will change with the change of pH value, while the equipment state remains constant from beginning to end, such as the stirring speed. When the viscosity fluctuates greatly during the coating process, the stirring speed does not change accordingly, then the uniformity of the coating process will be affected, and then uneven stirring will occur, resulting in fluctuations in product quality.

[0003] Therefore, there is an urgent need to improve the existing titanium dioxide inorganic coating method. Summary of the invention

[0004] The purpose of the present invention is to solve the above technical problems. According to the real-time viscosity concentration of the titanium dioxide slurry and a specific linear relationship, the stirring speed of the titanium dioxide slurry in the coating tank is adjusted in real time, thereby making the coating process more stable and improving the application performance of the product.

[0005] To achieve the above object, the present invention proposes an inorganic coating method for making the material more stable. During the inorganic coating process of titanium dioxide, the stirring speed of the titanium dioxide slurry is adjusted in real time according to the following formula (1):

[0006] Y=0.0046X+35.857 (1)

[0007] In formula (1), X is the real-time viscosity of titanium dioxide slurry, and its unit is mPa.s; Y is the stirring speed, and its unit is r / min.

[0008] Preferably, the value range of X is 10 to 20000 mPa.s.

[0009] Preferably, the present invention provides an inorganic coating method for making a material more stable, comprising the following steps:

[0010] S1. A circulation pipeline is arranged on the side wall of the coating tank. A viscosity detection device and a circulation pump are arranged in sequence along the medium flow direction on the circulation pipeline. The titanium dioxide slurry after viscosity detection is sent back to the coating tank through the circulation pump;

[0011] S2. A linkage relationship is established between the viscosity output signal of the viscosity detection device and the stirring speed signal of the stirring device on the coating tank according to formula (1) through the PLC controller, and the stirring speed of the stirring device is controlled in real time through the PLC controller.

[0012] Preferably, the stirring device comprises a stirring shaft, a stirring blade and a variable frequency motor, a stirring blade is provided at the lower part of the stirring shaft, and the stirring blade is immersed in the titanium dioxide slurry in the coating tank, and the variable frequency motor provides driving force for the stirring shaft.

[0013] Preferably, the concentration of the titanium dioxide slurry is 300±50 g / L.

[0014] Preferably, the inorganic coating is specifically a single aluminum coating or a silicon-aluminum coating.

[0015] The present invention also includes other steps or devices that can be normally implemented, all of which adopt conventional means in the art. In addition, the steps or devices not limited in the present invention also adopt the prior art in the art, and those skilled in the art can select them according to actual needs.

[0016] The working principle of the present invention is that, in the process of inorganic coating of titanium dioxide, the stirring speed is adjusted in real time according to the different viscosities of the materials, so that the slurry state in the coating process remains stable, thereby ensuring the uniformity of the coating process.

[0017] Compared with the prior art, this application has the following beneficial effects:

[0018] 1. The coating process is more stable, and the coating amount and coating effect of each link can be tested and monitored; if there are coating defects and coating accidents, adjustments can be made in time.

[0019] 2. Make the pH of the coating process material and the pH of the finished product more stable.

[0020] 3. Make the application performance of the finished product more excellent, such as 20 degree gloss, hiding power; linseed oil dispersibility, water-based high stirring, abrasion value and other properties are improved. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 It is a schematic diagram of the viscosity detection and stirring speed linkage process of titanium dioxide slurry in the coating tank. DETAILED DESCRIPTION

[0022] The technology of the present invention is further described in detail below in conjunction with the accompanying drawings and specific implementation methods.

[0023] Example:

[0024] This embodiment proposes an inorganic coating method for making materials more stable. During the inorganic coating process of titanium dioxide, the stirring speed of the titanium dioxide slurry is adjusted in real time according to the following formula (1):

[0025] Y=0.0046X+35.857 (1)

[0026] In formula (1), X is the real-time viscosity of titanium dioxide slurry, and its value range is 10-20000 mPa.s; Y is the stirring speed, and its unit is r / min.

[0027] The concentration of titanium dioxide slurry is 300±50g / L, and the inorganic coating is specifically a single aluminum coating or a silicon aluminum coating.

[0028] After testing the viscosity of titanium dioxide slurry and the corresponding stirring speed during the inorganic coating process, the following table was obtained:

[0029] Experimental comparison table of viscosity and stirring speed of titanium dioxide slurry

[0030] Serial number Viscosity mpa.s Stirring speed r / min 1 10 35.903 2 50 36.087 3 100 36.317 4 500 38.157 5 1000 40.457 6 2000 45.057 7 3000 49.657 8 5000 58.857 9 7500 70.357 10 10000 81.857

[0031] According to the above table, formula (1) can be fitted.

[0032] like Figure 1 As shown, in this embodiment, the following steps are also included:

[0033] S1. A circulation pipeline is arranged on the side wall of the coating tank. A viscosity detection device and a circulation pump are arranged in sequence along the medium flow direction on the circulation pipeline. The titanium dioxide slurry after viscosity detection is sent back to the coating tank through the circulation pump;

[0034] S2. A linkage relationship is established between the viscosity output signal of the viscosity detection device and the stirring speed signal of the stirring device on the coating tank according to formula (1) through the PLC controller, and the stirring speed of the stirring device is controlled in real time through the PLC controller.

[0035] The stirring device comprises a stirring shaft, stirring blades and a variable frequency motor. A stirring blade is provided at the lower part of the stirring shaft, and the stirring blade is immersed in the titanium dioxide slurry in the coating tank. The variable frequency motor provides driving force for the stirring shaft.

[0036] Application Example 1

[0037] Specifically for the single aluminum envelope, combined with the above embodiment, the specific operation process is as follows:

[0038] 1. Initially start stirring, add 20±5t of titanium dioxide slurry with a concentration of 300±50g / L into the coating tank, pump the titanium dioxide slurry into the viscosity testing device through the circulation pipeline, and then return it to the coating tank through the circulation pump after the test. Keep circulating the feed and keep the viscosity of the titanium dioxide slurry ≤200mPa.s. Perform real-time testing and adjust the stirring speed in real time according to formula (1) in the embodiment;

[0039] 2. Adjust the pH of the titanium dioxide slurry to 9-10, and maintain the viscosity of the titanium dioxide slurry ≤ 200 mPa.s. At the same time, adjust the stirring speed in real time according to the detected value of the real-time viscosity of the titanium dioxide slurry according to formula (1);

[0040] 3. Add sulfuric acid and sodium aluminate to flow in parallel, adjust the material viscosity to ≤1000 mPa.s, and adjust the stirring speed in real time according to formula (1), adjust the pH to 9-11, the coating layer is pseudo-boehmite type, the coating amount is 0.5-5%, take samples and dry them, and test the element analysis (coating amount);

[0041] 4. After the coating is completed, adjust the pH to 6.0-6.5 according to the process requirements. This coating scheme has a stable coating process, so the endpoint pH fluctuation is small (no need to take samples for testing and adjust the endpoint pH repeatedly). Adjust the endpoint pH to 5-8, continue to test the slurry viscosity during the coating process, and keep the slurry viscosity ≤10000mPa.s. At the same time, adjust the stirring speed in real time according to formula (1), and take samples after the entire coating process is completed;

[0042] 5. After the coated material is washed three times, flash dried and steam-powdered, the application performance of the product is tested.

[0043] For the same coating material in the above application example 1, four samples were taken at different points for testing each time. The test results are as follows:

[0044] pH test

[0045] pH test 1 2 3 4 Experimental Sample 7.0 7.0 7.0 7.0 Comparison (current process) 6.8 7.0 6.9 7.2

[0046] 20 degree gloss

[0047] 20 degree gloss 1 2 3 4 Experimental Sample 118 120 120 117 Comparison (current process) 115 112 118 110

[0048] TIDAS Dispersibility

[0049] TIDAS Dispersibility 1 2 3 4 Experimental Sample 10 11 12 10 Comparison (current process) 14 15 13 12

[0050] Water-based high stirring

[0051] Water-based high stirring 1 2 3 4 Experimental Sample 30 30 30 30 Comparison (current process) 30 30 40 30

[0052] Wear value

[0053] Wear value 1 2 3 4 Experimental Sample 12.85 13.20 12.21 12.35 Comparison (current process) 13.65 13.86 13.94 13.79

[0054] Application Example 2

[0055] Specifically for the silicon-aluminum coating, combined with the above embodiment, the specific operation process is as follows:

[0056] 1. Initially start stirring, add 20±5t of titanium dioxide slurry with a concentration of 300±50g / L into the coating tank, pump the titanium dioxide slurry into the viscosity testing device through the circulation pipeline, and then return it to the coating tank through the circulation pump after the test. Keep circulating the feed and keep the viscosity of the titanium dioxide slurry ≤200mPa.s. Perform real-time testing and adjust the stirring speed in real time according to formula (1) in the embodiment;

[0057] 2. Adjust the pH of the titanium dioxide slurry to 9-10, and maintain the viscosity of the titanium dioxide slurry ≤ 200 mPa.s. At the same time, adjust the stirring speed in real time according to the detected value of the real-time viscosity of the titanium dioxide slurry according to formula (1);

[0058] 3. Add sulfuric acid and sodium silicate to flow in parallel, adjust the material viscosity to ≤1500mPa.s, and adjust the stirring speed in real time according to formula (1). The coating amount is 1-3%, sample drying, and test element analysis (coating amount);

[0059] 4. Add sulfuric acid and sodium aluminate to flow in parallel, adjust the material viscosity to ≤3000 mPa.s, and adjust the stirring speed in real time according to formula (1), adjust the pH to 8-9, the coating layer is pseudo-boehmite type, the coating amount is 0.5-5%, take samples and dry them, and test the element analysis (coating amount);

[0060] 5. After the coating is completed, adjust the pH to 6.0-6.5 according to the process requirements. This coating scheme has a stable coating process, so the endpoint pH fluctuation is small (no need to take samples for testing and adjust the endpoint pH repeatedly). Adjust the endpoint pH to 5-8, continue to test the slurry viscosity during the coating process, and keep the slurry viscosity ≤10000mPa.s. At the same time, adjust the stirring speed in real time according to formula (1), and take samples after the entire coating process is completed;

[0061] 6. After the coated material is washed three times, flash dried and steam-powdered, the application performance of the product is tested.

[0062] Control experiment:

[0063] A control experiment was conducted with reference to Application Example 1. The only difference between the control experiment and the application example was that the stirring speed of the titanium dioxide slurry in the coating tank was not adjusted. The coated material obtained after the control experiment was washed three times, flash-dried, and steam-powdered to test the application performance of the product.

[0064] The following table is a comparison table of application performance of application example 1, application example 2 and control experiment

[0065] Serial number / index 20 degree gloss TIDAS Dispersibility Water-based high stirring Wear value pH Remark 1 121 11 30 12.56 7.0 Product of Application Example 1 2 120 11 30 12.23 7.0 Product of Application Example 2 3 118 16 40 13.24 7.3 The product of the controlled experiment

[0066] As can be seen from the above table, the coated materials obtained according to the present invention have a 20 degree gloss greater than that of the product of the control experiment, and TIDAS dispersibility (i.e., linseed oil dispersibility), aqueous high agitation, abrasion value, and pH are all lower than those of the product of the control experiment. It can be seen that the present invention can make the application performance of the finished product after coating more excellent.

[0067] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. An inorganic coating method for making materials more stable, characterized in that: During the inorganic coating process of titanium dioxide, the stirring speed of the titanium dioxide slurry is adjusted in real time according to the following formula (1): Y=0.0046X+35.857(1) In formula (1), X is the real-time viscosity of titanium dioxide slurry, ranging from 10 to 20000 mPa.s; Y is the stirring speed, the unit is r / min; The concentration of the titanium dioxide slurry is 300±50 g / L, and the inorganic coating is a single aluminum coating or a silicon-aluminum coating.

2. The inorganic coating method for making materials more stable according to claim 1, characterized in that: The steps include: S1. A circulation pipeline is arranged on the side wall of the coating tank. A viscosity detection device and a circulation pump are arranged in sequence along the medium flow direction on the circulation pipeline. The titanium dioxide slurry after viscosity detection is sent back to the coating tank through the circulation pump; S2. A linkage relationship is established between the viscosity output signal of the viscosity detection device and the stirring speed signal of the stirring device on the coating tank according to formula (1) through the PLC controller, and the stirring speed of the stirring device is controlled in real time through the PLC controller.

3. The inorganic coating method for making materials more stable according to claim 2, characterized in that: The stirring device comprises a stirring shaft, stirring blades and a variable frequency motor. A stirring blade is arranged at the lower part of the stirring shaft, and the stirring blade is immersed in the titanium dioxide slurry in the coating tank. The variable frequency motor provides driving force for the stirring shaft.

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