Preparation method of water-based intelligent anticorrosive paint, obtained product and application of product in steel

Abstract

The invention discloses a preparation method of a water-based intelligent anticorrosive coating, an obtained product and application of the product to steel, nano silica sol, methyltriethoxysilane, normal propyl alcohol and water are mixed, and organosilane sol is obtained; the preparation method comprises the following steps: mixing a zirconium n-propoxide solution, acetylacetone, n-propyl alcohol and water to obtain ZrO2 sol; mixing the organosilane sol and the ZrO2 sol, adding the nano TiO2, the carbon black and the dispersing agent, and performing ultrasonic dispersion and sufficient grinding to obtain the product. The preparation method is simple, the process is simple, and the obtained coating shows excellent corrosion resistance when used on various steel materials.

Description

TECHNICAL FIELD

[0001] The present application relates to a kind of preparation method of water-based intelligent anticorrosive coating and the product obtained and application on steel material, belong to the technical field of coating field. BACKGROUND

[0002] With the development of China's steel technology, its application in shipbuilding, construction, bridge and other aspects is also increasingly widespread. However, steel corrosion can seriously affect its mechanical properties, aesthetics and safety. Therefore, it is of great social and economic benefit to use certain protective measures to enhance the corrosion resistance of steel. Spraying paint on the surface of steel so as to isolate the steel from the environment that can easily cause corrosion, thereby avoiding the reaction between steel and the surrounding medium to cause corrosion is one of the simple and effective protection methods. At present, anti-rust paint is generally divided into two types: oil-based paint and water-based paint. Although oil-based paint is convenient to use and low in price, it contains a large amount of nitrite and other carcinogens, which poses a great threat to the human body and the environment, and its use has been restricted by the state. Therefore, the development of environmentally friendly, safe and excellent corrosion-resistant water-based paint has great application prospects. However, spraying paint on steel can only play a passive protection role, and once the coating is damaged, it will fail. In recent years, intelligent anticorrosive coating based on corrosion inhibitor nanocapsules can repair the damage to the coating according to the environment, prolonging the service life of the substrate. SUMMARY

[0003] The purpose of the present application is to provide a preparation method of water-based intelligent anticorrosive coating and the product obtained, the present application prepares an intelligent water-based coating with excellent corrosion resistance by compounding modified silane sol and ZrO2 sol, adjusting the hardness and flexibility of the coating, and then adding corrosion inhibitor, nano-TiO2 and carbon black.

[0004] The specific technical solutions of the present application are as follows: A preparation method of water-based intelligent anticorrosive coating, the method comprising the following steps: (1) mixing nano-silica sol, methyl triethoxysilane, n-propanol and water to obtain an organic silane sol; (2) mixing zirconium n-propanol solution, acetylacetone, n-propanol and water to obtain a ZrO2 sol; (3) mixing the organic silane sol and the ZrO2 sol to obtain a mixed sol-gel; (4) adding nano-TiO2, carbon black and a dispersing agent to the mixed sol-gel in step (3) above, ultrasonic dispersion and sufficient grinding to obtain a water-based intelligent anticorrosive coating.

[0005] Further, in step (1), the mass ratio of the nano-silica sol, methyl triethoxysilane, n-propanol and water is 13-15:19-20:15:2-3.

[0006] Further, in step (1), the solid content of the nanometer silicon sol is 25-30wt%.

[0007] Further, in step (1), the nanometer silicon sol is first mixed with water and stirred for 5-20 min, preferably 10 min, then n-propanol is added and stirred for 10-30 min, preferably 20 min, and finally methyl triethoxysilane is added dropwise and stirred for 1-2 h, preferably 1 h.

[0008] Further, in step (2), the zirconium n-propanol solution is a mixture of zirconium n-propanol and n-propanol, and the content of zirconium n-propanol is 70%.

[0009] Further, in step (2), the mass ratio of zirconium n-propanol solution, n-propanol, acetylacetone and water is 1:48-52:0.4-0.6:9-11.

[0010] Further, in step (2), the zirconium n-propanol solution and n-propanol are mixed, acetylacetone is dissolved in n-propanol, then the two solutions are mixed and stirred for 1-2 h, preferably 1 h, and finally water is added and stirred for 24-25 h.

[0011] Further, in step (3), the mass ratio of organosilane sol and ZrO2 sol is 4-10:1, preferably 8:1.

[0012] Further, in step (4), the mass of nanometer TiO2 and carbon black in the organosilane sol is 5-6% and 1-1.5%, respectively, preferably 5% and 1%.

[0013] Further, in step (4), the dispersant accounts for 0.8-1.2% of the total mass of nanometer TiO2 and carbon black. The dispersant is a commercial water-based ECO-2300 produced by Dongguan Aus Chemical Co., Ltd.

[0014] Further, in step (4), the size of nanometer TiO2 is 10-50 nm.

[0015] Further, in step (4), the ultrasonic power for ultrasonic dispersion is 100-300 W, the ultrasonic frequency is 20-40 kHz, the ultrasonic time is 10-20 min, preferably 10 min; the rotation speed during grinding is 300-400 r / min, and the time is 24-26 h.

[0016] Further, in step (4), the raw material of the anticorrosive coating of the present application further includes a corrosion inhibitor composite material packaged with bentonite Ce 3+ The preparation steps for adding the raw material are as follows: (S1) mixing nano-silica sol, methyl triethoxysilane, n-propanol and water to obtain an organic silane sol; (S2) mixing n-propanol zirconium solution, acetylacetone, n-propanol and water to obtain a ZrO2 sol; (S3) adding bentonite to an aqueous solution of Ce(NO3)3·6H2O, ion exchanging at elevated temperature, then centrifuging, washing and drying to obtain a bentonite-encapsulated Ce 3+ corrosion inhibitor composite material; (S4) mixing the organic silane sol and the ZrO2 sol to obtain a mixed sol-gel; (S5) adding the corrosion inhibitor composite material in step (3), nano-TiO2, carbon black and a dispersant to the mixed sol-gel in step (4) above, ultrasonic dispersing and thoroughly grinding to obtain a water-based intelligent anticorrosive coating Further, the operations in steps (S1), (S2) and (S4) are the same as those in steps (1), (2) and (3) above.

[0017] Further, in step (S3), the bentonite is added to the aqueous solution of Ce(NO3)3·6H2O for ion exchange. The molar ratio of Ce 3+ to bentonite is 20:2-4, and the molecular weight of the bentonite is calculated as Al2O334(SiO2)·H2O, with a molecular weight of 360.31.

[0018] Further, in step (S3), the ion exchange temperature is 75-85 ℃, preferably 80 ℃, and the exchange time is 20-26 h, preferably 24 h.

[0019] Further, in step (S3), anhydrous ethanol is used for washing, and the washing frequency is 2-5 times, preferably 3 times.

[0020] Further, in step (S5), the corrosion inhibitor composite material, nano-TiO2 and carbon black account for 0.5-2%, 5-6% and 1-1.5% of the mass of the organic silane sol, respectively, and preferably 1%, 5% and 1%.

[0021] Further, in step (S5), the dispersant accounts for 0.8-1.2% of the total mass of nano-TiO2 and carbon black. The dispersant is a commercial water-based ECO-2300 produced by Dongguan Aus Chemical Co., Ltd.

[0022] Further, in step (S5), the size of nano-TiO2 is 10-50 nm.

[0023] Further, in step (S5), the ultrasonic dispersion power is 100-300 W, the ultrasonic frequency is 20-40 kHz, the ultrasonic time is 10-20 min, preferably 10 min; the rotation speed during grinding is 300-400 r / min, and the time is 24-26 h.

[0024] The water-based intelligent coating prepared by the method has good corrosion resistance to various steels, and the water-based intelligent coating prepared by the method and the application of the coating in corrosion protection of steels are also within the protection scope.

[0025] The present application has the following beneficial effects: 1. The preparation method of the water-based intelligent corrosion-resistant coating is simple, the process is simple, and the industrial implementation is easy.

[0026] 2. The modified silane sol and ZrO2 sol are compounded to adjust the hardness and flexibility of the coating, then the corrosion inhibitor composite material, nano-TiO2, carbon black and dispersant are added, and through optimization of the ratio of various raw materials, the corrosion resistance and universality of the coating are improved, and excellent corrosion resistance is shown on various steels. BRIEF DESCRIPTION OF DRAWINGS

[0027] Figure 1 is a comparison diagram of the corrosion resistance of test samples coated with the coating prepared in example 1, example 2 and example 3.

[0028] Figure 2 is a comparison diagram of the corrosion resistance of test samples coated with the coating prepared in example 1 and example 4.

[0029] Figure 3 is a diagram of the corrosion resistance of test samples coated with the coating prepared in example 1 and example 5 after immersion for different times.

[0030] Figure 4 is a comparison diagram of the corrosion resistance of test samples coated with the coating prepared in example 5-7.

[0031] Figure 5 is a comparison diagram of the corrosion resistance of test samples coated with the coating prepared in example 1 and comparative example 1. DETAILED DESCRIPTION

[0032] The present application will be further described below through specific examples, and the following description is only exemplary and does not limit the protection scope of the present application.

[0033] In the following examples, the zirconium n-propoxide solution used is commercially available zirconium n-propoxide n-propanol solution with a content of 70 wt%. The nanoscale TiO2 used has a size of 10-50 nm. The ECO-2300 dispersant used is purchased from Dongguan Aus Chemical Co., Ltd.

[0034] Example 1 1. In a 500 mL beaker, 56 g of nanosilica sol with a mass fraction of 30 wt% was added, 8 g of deionized water was added, and stirring was carried out at 25-30°C and 200-300 r / min for 15 min; 60 g of n-propanol was added, and stirring was continued for 20 min; 78 g of methyltriethoxysilane was added dropwise at a rate of 1-2 drops per second, and stirring was carried out for 1.5 h to obtain 202 g of organosilane sol.

[0035] 2. 3.276 g of zirconium n-propoxide solution with a mass fraction of 70% was taken and dissolved in 81.9 g of n-propanol; 1.966 g of acetylacetone was taken and dissolved in 81.9 g of the remaining n-propanol, and the two solutions were separately ultrasonicated at 200 W and 30 kHz for 10 min; after mixing, stirring was carried out at 25-30°C and 200-300 r / min for 1.5 h, 29.484 g of deionized water was added in four portions with an interval of 12 min each, and stirring was continued for 24.5 h to obtain 198.526 g of ZrO2 sol.

[0036] 3. 202 g of organosilane sol was mixed with 25.25 g of ZrO2 sol; 11.1 g of nanoscale TiO2 with a particle size of 10-50 nm, 2.53 g of carbon black, and 0.136 g of water-based dispersant ECO-2300 were added; ultrasonication was carried out at 200 W and 30 kHz for 10 min, and grinding was carried out at 300 r / min for 24 h to obtain a water-based paint.

[0037] Example 2 The water-based paint was prepared according to the method of Example 1, except that in step 3, the mass of organosilane sol was replaced by 198 g, and the mass of ZrO2 sol was replaced by 49.5 g.

[0038] Example 3 The water-based paint was prepared according to the method of Example 1, except that in step 3, the mass of organosilane sol was replaced by 198 g, and the mass of ZrO2 sol was replaced by 19.8 g.

[0039] Example 4 The water-based paint was prepared according to the method of Example 1, except that in step 3, the addition amounts of nanoscale TiO2 and carbon black were changed to 10.3 g and 2.83 g, respectively.

[0040] Example 5 1. Preparation of organosilane sol: same as Example 1.

[0041] 2. Preparation of ZrO2 sol: same as Example 1.

[0042] 3. Preparation of corrosion inhibitor composite material: 26.053 g of Ce(NO3)3·6H2O and 300 g of deionized water were weighed into a 500 mL three-necked round-bottom flask (corresponding concentration of 0.2 M), stirred at 400 r / min for 30 min to dissolve completely, to obtain solution A; then 10.809 g of bentonite was weighed into the above solution A (molar ratio of Ce 3+ to bentonite of 20:3) to obtain a suspension; the above suspension was then transferred into an oil bath, and ion exchange was carried out at 80 ℃ for 24 h; after ion exchange, the suspension was naturally cooled, and washed with ethanol by centrifugation for three times; finally, the obtained solid was dried in an oven at 80 ℃ for 24 h, and grinded to obtain the corrosion inhibitor composite material of bentonite encapsulating Ce 3+ .

[0043] 4. 202 g of the organosilane sol prepared in step 1 and 25.25 g of the ZrO2 sol prepared in step 2 were mixed, then 2.02 g of the corrosion inhibitor composite material, 11.1 g of nano-TiO2 and 2.53 g of carbon black were added, and 0.136 g of water-based dispersant (ECO-2300) was further added; the mixed coating was ultrasonically dispersed in an ultrasonic disperser at a power of 200 W and a frequency of 30 kHz for 10 min, and then grinded at a speed of 300 r / min for 24 h to obtain a water-based coating.

[0044] Example 6 The water-based coating was prepared according to the method of Example 5, except that the amount of the corrosion inhibitor composite material was changed from 2.02 g to 1.01 g.

[0045] Example 7 The water-based coating was prepared according to the method of Example 5, except that the amount of the corrosion inhibitor composite material was changed from 2.02 g to 4.04 g.

[0046] Comparative Example 1 The water-based coating was prepared according to the method of Example 1, except that step 2 was omitted, and no ZrO2 sol was added in step 3.

[0047] Application Example In order to evaluate the corrosion resistance of the water-based coating prepared in the application to steel, electrochemical impedance test was carried out. The specific experimental steps were as follows: 1. The water-based paints prepared in Examples 1-7 and Comparative Example 1 were respectively roll-coated on 201 stainless steel plates with the size of 12 x 18 x 1.5 mm, the roll-coating mode and the roll-coating amount were kept consistent, the thickness was about 5 μm, and the roll-coated samples were naturally dried for 2 h to obtain the test samples with anticorrosive coatings.

[0048] 2. The test was performed by using the IVIUM electrochemical workstation imported from Holland, the standard three-electrode system was used as the test system, the reference electrode was a mercury-mercury oxide electrode, the auxiliary electrode was a graphite electrode, and the working electrode was the test sample (the exposed test area was 1 cm 2 ). The scanning frequency range of the alternating current impedance spectrum was 100 kHz-10 mHz, and the amplitude was 50 mV.

[0049] 3. Experimental results Figure 1 is the comparison chart of the anticorrosive properties of the test samples coated with the paints of Examples 1-3. The results show that the coating prepared in Example 1 has the best anticorrosive property, indicating that the optimal mass ratio of the organosilane sol and the ZrO2 sol is 8:1.

[0050] Figure 2 is the comparison chart of the anticorrosive properties of the test samples coated with the paints of Examples 1 and 4. The results show that the coating prepared in Example 1 has relatively good anticorrosive property, indicating that too much nano-based TiO2 and carbon black leads to the decrease of the anticorrosive property of the coating.

[0051] Figure 3 is the chart of the anticorrosive properties of the test samples coated with the paints of Examples 1 and 5 after being immersed for different time. The results show that although the coating prepared in Example 1 has good anticorrosive property, its anticorrosive property decreases obviously with the extension of the immersion time in the corrosion medium (5wt% NaCl solution), while the anticorrosive property of the coating prepared in Example 5 has a significant rebound phenomenon after being immersed in the corrosion medium for 12 h, indicating that the coating prepared in Example 5 releases the corrosion inhibitor after being immersed in the corrosion medium for a period of time, thereby improving the anticorrosive ability of the coating.

[0052] Figure 4 is the comparison chart of the anticorrosive properties of the test samples coated with the paints of Examples 5-7. The results show that the coating prepared in Example 5 has the best anticorrosive property, indicating that the optimal ratio of the corrosion inhibitor to the mass of the organosilane sol is 1%.

[0053] Figure 5 is the comparison chart of the anticorrosive properties of the test samples coated with the paints of Examples 1 and Comparative Example 1. The results show that the coating prepared in Example 1 has better anticorrosive property, indicating that the addition of an appropriate amount of ZrO2 sol is beneficial to the anticorrosive property of the paint.

Claims

1. A method for preparing a water-based intelligent anti-corrosion coating, characterized in that: Includes the following steps: (1) Mix nano-silica sol, methyltriethoxysilane, n-propanol and water to obtain organosilane sol; (2) Mix zirconium propoxide solution, acetylacetone, n-propanol and water to obtain ZrO2 sol; (3) Mix the organosilane sol and ZrO2 sol to obtain a mixed sol-gel; (4) Add nano TiO2, carbon black and dispersant to the mixed sol gel in step (3) above, disperse by ultrasonication and grind thoroughly to obtain water-based intelligent anti-corrosion coating.

2. The preparation method according to claim 1, characterized in that: In step (1), the mass ratio of the nano-silica sol, methyltriethoxysilane, n-propanol, and water is 13-15:19-20:15:2-3; preferably, the solid content of the nano-silica sol is 25-30 wt%. Preferably, in step (1), the nano-silica sol is first mixed with water and stirred for 5-20 min, then n-propanol is added and stirred for 10-30 min, and finally methyltriethoxysilane is added dropwise during the stirring process and stirred for 1-2 h.

3. The preparation method according to claim 1, characterized in that: In step (2), the zirconium propoxide solution is a mixture of zirconium propoxide and n-propanol, with a zirconium propoxide content of 70%; the mass ratio of zirconium propoxide solution, n-propanol, acetylacetone and water is 1:48-52:0.4-0.6:9-11.

4. The preparation method according to claim 1 or 4, characterized in that: In step (2), zirconium propoxide solution and n-propanol are mixed, acetylacetone is dissolved in n-propanol, and then the two solutions are mixed and stirred for 1-2 h. Finally, water is added and stirred for 24-25 h.

5. The preparation method according to claim 1, characterized in that: In step (3), the mass ratio of organosilane sol to ZrO2 sol is 4-10:

1.

6. The preparation method according to claim 1, characterized in that: In step (4), nano-TiO2 accounts for 5-6% of the mass of the organosilane sol, carbon black accounts for 1-1.5% of the mass of the organosilane sol, and the dispersant accounts for 0.8-1.2% of the total mass of nano-TiO2 and carbon black; preferably, the dispersant is commercially available water-based ECO-2300 produced by Dongguan Aus Chemical Co., Ltd.; preferably, the particle size of nano-TiO2 is 10-50 nm.

7. The preparation method according to claim 1 or 6, characterized in that: In step (4), the ultrasonic power of ultrasonic dispersion is 100-300W, the ultrasonic frequency is 20-40kHz, the ultrasonic time is 10-20 min, the rotation speed during grinding is 300-400 r / min, and the grinding time is 24-26h.

8. The preparation method according to any one of claims 1-7, characterized in that: In step (4), in addition to nano-TiO2, carbon black and dispersant, bentonite encapsulating Ce is also added to the mixed sol-gel in step (3). 3+ The corrosion inhibitor composite material, wherein the bentonite-encapsulated Ce 3+ The corrosion inhibitor composite material is prepared by adding bentonite to an aqueous solution of Ce(NO3)3·6H2O, heating for ion exchange, followed by centrifugation, washing, and drying to obtain bentonite-encapsulated Ce. 3+ Corrosion inhibitor composite materials; preferably, Ce 3+ The molar ratio of bentonite to bentonite is 20:2-4; the ion exchange temperature is 75-85 ℃, and the exchange time is 20-26 h.

9. The preparation method according to claim 8, characterized in that: Bentonite Encapsulation Ce 3+ The corrosion inhibitor composite material accounts for 0.5-2% of the mass of the organosilane sol.

10. A water-based intelligent anti-corrosion coating obtained by any one of claims 1-9, and the application of the water-based intelligent anti-corrosion coating in steel corrosion protection.

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