CN114959675A - Silicate passivation solution and preparation method thereof - Google Patents
Silicate passivation solution and preparation method thereof Download PDFInfo
- Publication number
- CN114959675A CN114959675A CN202210714133.XA CN202210714133A CN114959675A CN 114959675 A CN114959675 A CN 114959675A CN 202210714133 A CN202210714133 A CN 202210714133A CN 114959675 A CN114959675 A CN 114959675A
- Authority
- CN
- China
- Prior art keywords
- solution
- passivation
- silicate
- sodium hydroxide
- aluminum phosphate
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Granted
Links
Classifications
-
- C—CHEMISTRY; METALLURGY
- C23—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; CHEMICAL SURFACE TREATMENT; DIFFUSION TREATMENT OF METALLIC MATERIAL; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION IN GENERAL
- C23C—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; SURFACE TREATMENT OF METALLIC MATERIAL BY DIFFUSION INTO THE SURFACE, BY CHEMICAL CONVERSION OR SUBSTITUTION; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL
- C23C22/00—Chemical surface treatment of metallic material by reaction of the surface with a reactive liquid, leaving reaction products of surface material in the coating, e.g. conversion coatings, passivation of metals
- C23C22/05—Chemical surface treatment of metallic material by reaction of the surface with a reactive liquid, leaving reaction products of surface material in the coating, e.g. conversion coatings, passivation of metals using aqueous solutions
- C23C22/60—Chemical surface treatment of metallic material by reaction of the surface with a reactive liquid, leaving reaction products of surface material in the coating, e.g. conversion coatings, passivation of metals using aqueous solutions using alkaline aqueous solutions with pH greater than 8
-
- C—CHEMISTRY; METALLURGY
- C01—INORGANIC CHEMISTRY
- C01B—NON-METALLIC ELEMENTS; COMPOUNDS THEREOF; METALLOIDS OR COMPOUNDS THEREOF NOT COVERED BY SUBCLASS C01C
- C01B33/00—Silicon; Compounds thereof
- C01B33/20—Silicates
- C01B33/32—Alkali metal silicates
-
- C—CHEMISTRY; METALLURGY
- C01—INORGANIC CHEMISTRY
- C01F—COMPOUNDS OF THE METALS BERYLLIUM, MAGNESIUM, ALUMINIUM, CALCIUM, STRONTIUM, BARIUM, RADIUM, THORIUM, OR OF THE RARE-EARTH METALS
- C01F7/00—Compounds of aluminium
- C01F7/02—Aluminium oxide; Aluminium hydroxide; Aluminates
- C01F7/021—After-treatment of oxides or hydroxides
-
- C—CHEMISTRY; METALLURGY
- C23—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; CHEMICAL SURFACE TREATMENT; DIFFUSION TREATMENT OF METALLIC MATERIAL; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION IN GENERAL
- C23C—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; SURFACE TREATMENT OF METALLIC MATERIAL BY DIFFUSION INTO THE SURFACE, BY CHEMICAL CONVERSION OR SUBSTITUTION; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL
- C23C2/00—Hot-dipping or immersion processes for applying the coating material in the molten state without affecting the shape; Apparatus therefor
- C23C2/04—Hot-dipping or immersion processes for applying the coating material in the molten state without affecting the shape; Apparatus therefor characterised by the coating material
- C23C2/06—Zinc or cadmium or alloys based thereon
-
- C—CHEMISTRY; METALLURGY
- C23—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; CHEMICAL SURFACE TREATMENT; DIFFUSION TREATMENT OF METALLIC MATERIAL; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION IN GENERAL
- C23C—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; SURFACE TREATMENT OF METALLIC MATERIAL BY DIFFUSION INTO THE SURFACE, BY CHEMICAL CONVERSION OR SUBSTITUTION; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL
- C23C2/00—Hot-dipping or immersion processes for applying the coating material in the molten state without affecting the shape; Apparatus therefor
- C23C2/26—After-treatment
Landscapes
- Chemical & Material Sciences (AREA)
- Organic Chemistry (AREA)
- Chemical Kinetics & Catalysis (AREA)
- Engineering & Computer Science (AREA)
- Materials Engineering (AREA)
- Mechanical Engineering (AREA)
- Metallurgy (AREA)
- Inorganic Chemistry (AREA)
- General Chemical & Material Sciences (AREA)
- Life Sciences & Earth Sciences (AREA)
- Geology (AREA)
- Chemical Treatment Of Metals (AREA)
Abstract
The application relates to the technical field of metal material surface treatment, and particularly discloses a silicate passivation solution and a preparation method thereof. The silicate passivation solution comprises the following components: 1-20 g/L of sodium hydroxide, 3-60 g/L of silicon dioxide, 3-60 g/L of an aluminum phosphate mixture, and the balance of water, wherein the molar ratio of the sodium hydroxide to the silicon dioxide is 0.5-0.7, and the viscosity of the aluminum phosphate mixture is 0.15-0.3 Pa.s; the preparation method comprises the following steps: dissolving sodium hydroxide in water, and adding silicon dioxide into the water to obtain a mixed solution; and adding an aluminum phosphate mixture into the mixed solution, and finally adding a passivation auxiliary agent to obtain a silicate passivation solution, wherein the passivation auxiliary agent is one or more of nano oxide, dopamine modified nano oxide and polydopamine microcapsule. The silicate passivation solution is used for passivation treatment of galvanized steel parts and has the advantage of enhancing corrosion resistance of a passivation film.
Description
Technical Field
The application relates to the technical field of metal material surface treatment, in particular to a silicate passivation solution and a preparation method thereof.
Background
In order to improve the corrosion resistance of galvanized steel products, the zinc coating needs to be put into a passivation solution for passivation treatment, and then a passivation film is formed on the surface of the zinc coating. The passivation solution usually adopts chromate as a film forming agent, chromium is a heavy metal element and has great harm to the environment and human bodies, so that a chromium-free passivation technology for replacing chromate needs to be researched, wherein the silicate passivation solution is emphasized due to the advantages of low toxicity, low price and the like.
In the prior art, a sodium silicate solution is used as a main film forming agent, and the sodium silicate passivation solution comprises a single sodium silicate passivation solution and a composite sodium silicate passivation solution. As can be known from a large amount of literature and experiments, the single sodium silicate passivation solution has a lower passivation effect than the composite sodium silicate passivation solution.
The composite sodium silicate passivating solution is prepared by adding organic additive or inorganic additive into sodium silicate solution. The organic additive is acrylic resin, polyurethane, silane, etc. and the inorganic additive is hydrogen peroxide, nitric acid, phosphoric acid, etc. The kind and addition amount of the additive have great influence on the performance of the passive film.
The applicant finds that the galvanized steel piece is passivated by using a sodium silicate-phosphoric acid system, an acid salt spray corrosion test is carried out on the galvanized steel piece with a passivation film attached to the surface, the corrosion resistance of the passivation film is evaluated by detecting the surface corrosion area of the galvanized steel piece, and the detection result shows that: the corrosion area of a passive film formed by a sodium silicate-phosphoric acid system in an acid environment with the pH value of 3.5 is as high as 5.1 percent, and the galvanized steel piece is difficult to be applied to severe environments such as an acid processing plant and the like. Therefore, the sodium silicate-phosphoric acid passivation solution system is to be further improved.
Disclosure of Invention
In order to solve the problem that a passivation film formed by a sodium silicate-phosphoric acid passivation solution system has poor corrosion resistance in an acid environment, the application provides a silicate passivation solution and a preparation method thereof.
In a first aspect, the present application provides a silicate passivation solution, which adopts the following technical scheme:
the silicate passivation solution comprises the following raw materials: 1-20 g/L of sodium hydroxide, 3-60 g/L of silicon dioxide, 3-60 g/L of an aluminum phosphate mixture and the balance of water, wherein the molar ratio of the sodium hydroxide to the silicon dioxide is 0.5-0.7, and the viscosity of the aluminum phosphate is 0.15-0.3 Pa.s.
By adopting the technical scheme, sodium hydroxide and silicon dioxide in a specific molar ratio react to generate sodium silicate, the aluminum phosphate mixture with specific viscosity and the sodium silicate have a synergistic effect, and the aluminum phosphate mixture and the sodium silicate are matched with each other, so that the corrosion area of the passivated metal surface is less than 5%.
Preferably, the molar ratio of the sodium hydroxide to the silica is 0.57-0.67.
By adopting the technical scheme, the corrosion resistance of the passivation film is enhanced along with the reduction of the molar ratio of the sodium hydroxide to the silicon dioxide, when the molar ratio of the sodium hydroxide to the silicon dioxide is 0.57-0.67, the corrosion resistance of the passivation film is relatively optimal, and when the molar ratio of the sodium hydroxide to the silicon dioxide is continuously reduced, the corrosion resistance of the passivation film is slightly reduced, so that the molar ratio of the sodium hydroxide to the silicon dioxide is controlled to be 0.57-0.67, the better corrosion resistance can be achieved by using a proper amount of raw materials, and the waste of the raw materials is reduced.
Preferably, the viscosity of the aluminum phosphate mixture is 0.2-0.25 Pa.s.
By adopting the technical scheme, the viscosity of the aluminum phosphate mixture is controlled in a smaller range, and the passive film with better corrosion resistance is obtained.
Preferably, the raw material of the silicate passivation solution further comprises 5-60 g/L of nano oxide.
By adopting the technical scheme, the alkaline environment of the sodium silicate solution enables the nano-oxide to be well dispersed in the passivation solution, and the uniformly dispersed nano-oxide is filled in the holes on the surface of the passivation film in the process of forming the passivation film, so that the compactness of the passivation film is improved, and the corrosion resistance of the passivation film is enhanced.
Preferably, the nano oxide is any one or more of nano silicon dioxide, nano aluminum oxide and nano zinc oxide.
By adopting the technical scheme, no new element is introduced into the passivation solution system by the nano oxide, so that the probability of electron migration among different particles is reduced, the probability of corrosion inside the passivation film system is reduced, and the corrosion resistance of the passivation film is enhanced.
Preferably, the nano-oxide is a dopamine modified nano-oxide.
By adopting the technical scheme, under the alkaline environment with the pH value of 8-10, dopamine is self-polymerized on the surfaces of the nano particles to form a polydopamine film, the aggregation phenomenon of the nano particles is reduced by coating the polydopamine film, and the nano oxides are favorably and uniformly dispersed in a passivation solution system.
Preferably, the raw material of the silicate passivation solution further comprises 1-5 g/L of polydopamine microcapsule loaded with aluminum dihydrogen tripolyphosphate.
By adopting the technical scheme, when the passivation film is damaged and exposed out of the metal matrix, the acidic corrosion medium enables the pH environment on the metal surface to change rapidly, the polydopamine layer of the polydopamine microcapsule loaded with the aluminium dihydrogen tripolyphosphate is decomposed, the aluminium dihydrogen tripolyphosphate is released from the shell layer structure of the polydopamine microcapsule, the polydopamine and the aluminium dihydrogen tripolyphosphate are chelated with metal ions respectively, the release of the aluminium dihydrogen tripolyphosphate from the polydopamine microcapsule is accelerated by the electrostatic repulsion between charges of the same kind, a compact adsorption film is rapidly formed at the damaged part of the passivation film, the continuous contact between the acidic corrosion medium and the metal matrix is blocked, and therefore the corrosion resistance of the passivation film is enhanced.
In a second aspect, the application provides a preparation method of a silicate passivation solution, which adopts the following technical scheme:
a preparation method of silicate passivation solution comprises the following steps:
A. dissolving sodium hydroxide in water to obtain a sodium hydroxide solution A;
B. adding silicon dioxide into a sodium hydroxide solution A to obtain a mixed solution B;
C. adding the aluminum phosphate mixture into the mixed solution B to obtain a mixed solution C;
D. and adding a passivation auxiliary agent into the mixed solution C to obtain a silicate passivation solution, wherein the passivation auxiliary agent is any one or more of a nano oxide, a dopamine modified nano oxide and a polydopamine microcapsule.
By adopting the technical scheme, the passivation solution is prepared by mixing and stirring, the operation is simple, no toxic substances such as heavy metals are involved in the operation process, and the harm to operators is small.
In summary, the present application has the following beneficial effects:
1. according to the preparation method, sodium hydroxide and silicon dioxide in a specific molar ratio are reacted to prepare sodium silicate, an aluminum phosphate mixture with appropriate viscosity is added into a sodium silicate solution system, and the aluminum phosphate mixture and the sodium silicate act synergistically to enhance the corrosion resistance of a passive film; the preparation method of the silicate passivation solution is prepared by mixing and stirring the raw materials, and is simple and safe to operate.
2. In the application, dopamine modified nano-oxide is preferably added into a passivation solution system, and a polydopamine layer formed by dopamine self-polymerization is coated on the surfaces of nanoparticles, so that the nanoparticles are uniformly dispersed in the passivation solution system and then filled into holes on the surface of a film, and the corrosion resistance of the passivation film is enhanced.
3. In the application, polydopamine microcapsules loaded with aluminium dihydrogen tripolyphosphate are preferably added into the passivation solution, and when the passivation film is damaged, the aluminium dihydrogen tripolyphosphate is released from the polydopamine microcapsules to quickly form a layer of compact adsorption film, so that a corrosion medium is blocked, and the corrosion resistance of the passivation film is enhanced.
Detailed Description
The present application will be described in further detail with reference to examples.
Preparation example 1
The dopamine modified nano-alumina is prepared according to the following steps:
adding 1g of nano-alumina into 500mL of Tris-HCl (pH 8.5) buffer solution, performing ultrasonic dispersion for 45min, adding 1g of dopamine hydrochloride, performing magnetic stirring at 30 ℃ for 24h, centrifuging, washing a centrifugal product with ethanol and deionized water sequentially for three times, and drying to constant weight to obtain the dopamine modified nano-alumina.
Preparation example 2
The polydopamine microcapsule loaded with aluminum dihydrogen tripolyphosphate is prepared according to the following steps:
dopamine-modified nanosilica was obtained according to the method described in preparation example 1, replacing the nanosilica with nanosilica in preparation example 1.
Putting dopamine modified nano silicon dioxide into HF/NH 4 And F (pH is 5) solution is centrifuged, the centrifugation rotating speed is 6000rpm, and the centrifuged product is washed by ethanol and deionized water for three times to obtain the blank polydopamine microcapsule.
Putting aluminium dihydrogen tripolyphosphate into water, performing ultrasonic dispersion for 15min to obtain pre-dispersion liquid, putting blank polydopamine microcapsules into the pre-dispersion liquid, stirring for 24h to obtain suspension, washing the suspension with ethanol for three times, and performing vacuum drying to obtain the polydopamine microcapsules loading the aluminium dihydrogen tripolyphosphate.
Preparation example 3
An aluminum phosphate mixture prepared by the following steps:
100g of phosphoric acid with the content of 85 percent and 29.3g of aluminum hydroxide are mixed, heated and stirred at the temperature of 80 ℃ until the reaction system is in a clear and viscous liquid state, and an aluminum phosphate mixture with the viscosity of 0.24Pa s is obtained.
Preparation example 4
An aluminum phosphate mixture prepared by the steps of:
100g of phosphoric acid with the content of 85 percent and 27.1g of aluminum hydroxide are mixed, heated and stirred at the temperature of 80 ℃ until the reaction system is in a clear and viscous liquid state, and an aluminum phosphate mixture with the viscosity of 0.15 Pa.s is obtained.
Preparation example 5
An aluminum phosphate mixture prepared by the steps of:
100g of phosphoric acid with the content of 85 percent and 30.4g of aluminum hydroxide are mixed, heated and stirred at the temperature of 80 ℃ until the reaction system is in a clear and viscous liquid state, and an aluminum phosphate mixture with the viscosity of 0.3Pa s is obtained.
Preparation example 6
An aluminum phosphate mixture prepared by the steps of:
100g of phosphoric acid with the content of 85 percent and 31.6g of aluminum hydroxide are mixed, heated and stirred at the temperature of 80 ℃ until the reaction system is in a clear and viscous liquid state, and an aluminum phosphate mixture with the viscosity of 0.5 Pa.s is obtained.
Preparation example 7
An aluminum phosphate mixture prepared by the steps of:
100g of phosphoric acid with the content of 85 percent and 24.8g of aluminum hydroxide are mixed, heated and stirred at the temperature of 80 ℃ until the reaction system is in a clear and viscous liquid state, and an aluminum phosphate mixture with the viscosity of 0.1 Pa.s is obtained.
Examples
Examples 1 to 9
Examples 1 to 9 each provide a silicate passivation solution, the volume of the passivation solution is 1L, and examples 1 to 9 are different in the types and contents of components in the passivation solutions, specifically as shown in table 1, wherein Nano-ZnO refers to Nano-zinc oxide.
TABLE 1 types and amounts of the components of examples 1-9
The silicate passivating solutions of examples 1-9 were prepared by the following procedure:
A. weighing the raw materials according to the formula amount in the table 1, putting sodium hydroxide into a plastic beaker, adding 400mL of water into the plastic beaker, and stirring to completely dissolve the sodium hydroxide to obtain a sodium hydroxide solution A;
B. adding silicon dioxide into the sodium hydroxide solution A, and fully stirring until no solid insoluble substances exist in the beaker to obtain a mixed solution B;
C. continuously adding the aluminum phosphate mixture into the mixed solution B, and stirring to obtain a mixed solution C;
D. and finally, adding a passivation aid into the mixed solution C, wherein the passivation aid is selected from nano zinc oxide, dopamine modified nano aluminum oxide and poly dopamine microcapsule loaded with aluminium dihydrogen tripolyphosphate, adding according to the formula corresponding to each embodiment, adding water to a constant volume of 1L, and standing to obtain a silicate passivation solution.
Comparative example
Comparative examples 1 to 8
Comparative examples 1 to 8 each provide a silicate passivation solution, the volume of which is 1L, and comparative examples 1 to 8 differ in the type and content of components in the passivation solution, as shown in table 2.
TABLE 2 types and contents of respective components in comparative examples 1 to 8
Note that: the composition of comparative example 8 contained no sodium hydroxide and no silica, so comparative example 8 "NaOH/SiO" in Table 2 2 The molar ratio "one column is marked as" - ".
Performance test
After being scrubbed by ethanol, washed by tap water and distilled water, the galvanized steel piece is placed in silicate passivation solution at the temperature of 30 ℃ for treatment for 1min, then the galvanized steel piece is taken out of the silicate passivation solution and dried at the temperature of 100 ℃ for 20min, and a passivation film is formed on the surface of the galvanized steel piece.
The using effect of different types of silicate passivation solutions is characterized by testing the corrosion resistance of the passivation film, and the corrosion resistance of the passivation film is evaluated by an acid salt spray corrosion test and an electrochemical test.
Detection method
The acid salt spray corrosion test is carried out by putting the passivated galvanized steel piece into a salt spray corrosion test box, wherein the temperature in the spray box is 35 ℃; the sedimentation amount is 2mL/(80 cm) 2 H); the test sample is placed at an angle of 30 degrees with the vertical direction, the spraying test mode is periodic spraying, 24 hours are one period, spraying is continuously carried out for 8 hours in one period, stopping spraying is carried out for 16 hours, and the surface corrosion area of the galvanized steel piece after four periods of spraying is used as an evaluation parameter. The acidic environment is a 5 wt% acidic NaCl solution at pH 3.5, and the acidic environment is a 0.6 wt% acidic NaCl solution at pH 2.5.
The electrochemical test is carried out by putting the passivated galvanized steel piece into an electrochemical workstation, wherein the electrochemical workstation adopts a conventional three-electrode system, and an auxiliary electrode is 10cm 2 A platinum electrode, a reference electrode which is a saturated calomel electrode and a passivated galvanized steel piece which is a working electrodeSoaking the three electrodes in 5 wt% NaCl solution for 20min, measuring polarization curve after the corrosion potential is stabilized, and polarizing resistance R p And corrosion current density i cor As an evaluation parameter.
The specific detection results are shown in Table 3, wherein the "type" refers to the type of passivation solution used in the passivation treatment.
TABLE 3 results of acid salt spray Corrosion test and electrochemical test
Referring to the corrosion area data in table 3, the corrosion area data of the passive films obtained in examples 1 to 9 in the first acid environment and the second acid environment are both less than 5%, and the corrosion area data of the passive films obtained in comparative examples 1 to 8 is greater than or equal to 5%, that is, after the corrosion of the acid salt mist for the same time, the corrosion resistance of the passive films obtained in examples 1 to 9 is better than that of the passive films obtained in comparative examples 1 to 8; even in the acidic environment of lower pH, the corrosion resistance of the passive films obtained in examples 1 to 9 is superior to that of comparative examples 1 to 8. Further, data from electrochemical tests were used for analysis between each example and each comparative example.
Combining example 2, comparative example 6 and comparative example 7, the polarization resistance of the passive film obtained in example 2 is larger than that of comparative example 6 and comparative example 7, and the corrosion current density of the passive film obtained in example 2 is smaller than that of comparative example 6 and comparative example 7, i.e., the corrosion resistance of the passive film obtained in example 2 is better than that of comparative example 6 and comparative example 7, which shows that the corrosion resistance of the passive film can be improved by adding phosphoric acid or phosphate salt to the sodium silicate system, wherein the effect of adding the aluminum phosphate mixture is relatively better.
Combining example 2, comparative example 1 and comparative example 8, the corrosion resistance of the passive film obtained in example 2 is better than that of comparative example 1 and comparative example 8, which shows that the mixture of sodium silicate and aluminum phosphate has synergistic effect in improving the corrosion resistance of the passive film, presumably because: in the process of forming the sodium silicate passive film, the aluminum phosphate mixture is adhered to the surface of the passive film, so that the thickness and the strength of the passive film are improved.
The corrosion resistance of the passive film obtained in example 2 is relatively optimal by combining example 1, example 2, example 3, comparative example 2 and comparative example 3, which shows that NaOH and SiO 2 The molar ratio of (b) has a certain influence on the corrosion resistance of the obtained passive film, when NaOH and SiO are used 2 The molar ratio of (A) to (B) is controlled to be 0.5-0.7, and the corrosion resistance of the formed passive film is relatively higher.
The reason for this speculation may be: when the molar ratio of sodium hydroxide to silicon dioxide is 0.5-0.7, part of sodium silicate is condensed into polymeric silicon dioxide to form silica sol, and the silica sol nanoparticles are filled in a net structure formed by silicon-oxygen bonds; meanwhile, the silicic acid negative ion polymerization degree is large, and Si-O connection in the sodium silicate solution is mainly in a two-dimensional and three-dimensional complex structure, so that the strength of the obtained passivation film is higher, and the corrosion resistance is higher.
When NaOH and SiO 2 When the molar ratio is more than 0.7, the concentration of silica sol in the sodium silicate solution is low, the structure formed by Si-O connection is mostly simple, and the adhesion of the system is reduced, so that the thickness of the obtained passivation film is reduced and the corrosion resistance is reduced.
When NaOH and SiO 2 When the molar ratio is less than 0.5, silica sol nanoparticles which can be contained in a net structure consisting of silicon-oxygen bonds are saturated, and a large amount of silica sol nanoparticles dispersed in a sodium silicate system reduce the fluidity of a passivation solution system, so that the surface flatness of the obtained passivation film is reduced, and the corrosion resistance of the passivation film is further reduced.
The corrosion resistance of the passive film obtained in the embodiment 2 is relatively optimal by combining the embodiments 2, 4, 5, 4 and 5, which shows that the viscosity of the aluminum phosphate mixture has a certain influence on the corrosion resistance of the passive film, and the corrosion resistance of the passive film formed when the viscosity of the aluminum phosphate mixture is controlled within 0.15-0.3 Pa.s is relatively higher.
The reason for this speculation may be: the aluminum phosphate mixture comprises three components, namely aluminum dihydrogen phosphate, aluminum monohydrogen phosphate and aluminum orthophosphate, the viscosity of the aluminum phosphate mixture is different, the proportion of each component is different, and when the viscosity of the aluminum phosphate mixture is 0.15-0.3 Pa.s, the aluminum phosphate mixture has good adhesion and fluidity and can be filled in surface pores of a sodium silicate passivation film to improve the density of the passivation film, so that the corrosion resistance of the passivation film is enhanced.
When the viscosity of the aluminum phosphate mixture is more than 0.3Pa · s, the fluidity of the aluminum phosphate mixture is reduced, and effective filling is difficult to occur; when the viscosity is less than 0.15Pa · s, the viscosity is too low so that the adhesion of the aluminum phosphate mixture is reduced and the synergistic effect with sodium silicate is difficult.
Combining example 2, example 6 and example 7, the corrosion resistance of the passive film obtained in example 6 and example 7 is better than that of example 2, which shows that the addition of nano-oxide in the passivation solution can improve the corrosion resistance of the passive film because: the nano particles have good filling effect, can be filled in surface pores of the passive film, improve the density of the passive film and enhance the corrosion resistance of the passive film.
Combining example 6 and example 8, the corrosion resistance of the passivation film obtained in example 8 is better than that of example 6, which shows that: compared with the nano oxide, the dopamine modified nano oxide can better improve the corrosion resistance of the passive film, and the reasons are as follows: the modified nano particles have low agglomeration probability, and can be uniformly dispersed in a passivation solution system, so that the filling effect can be better exerted, the density of the passivation film is improved, and the corrosion resistance of the passivation film is enhanced.
Combining example 2 and example 9, the corrosion resistance of the passivation film obtained in example 9 is better than that of example 2, which shows that adding dopamine microcapsule loaded with aluminum dihydrogen tripolyphosphate into the passivation liquid system can improve the corrosion resistance of the passivation film, because: after the passivation film is damaged by an acidic corrosive medium, the poly dopamine layer is decomposed in an acidic environment, the aluminium dihydrogen tripolyphosphate is released from a shell layer structure in the dopamine microcapsule, and the poly dopamine and the aluminium dihydrogen tripolyphosphate can be chelated with metal ions, so that the release of the aluminium dihydrogen tripolyphosphate is accelerated by the electrostatic repulsion between charges of the same kind, an adsorption film is rapidly formed at the damaged part of the passivation film, the self-healing capability of the passivation film is enhanced, and the corrosion resistance of the passivation film is enhanced.
The present embodiment is only for explaining the present application, and it is not limited to the present application, and those skilled in the art can make modifications of the present embodiment without inventive contribution as needed after reading the present specification, but all of them are protected by patent law within the scope of the claims of the present application.
Claims (8)
1. The silicate passivation solution is characterized in that the raw materials of the silicate passivation solution comprise the following components: 1-20 g/L of sodium hydroxide, 3-60 g/L of silicon dioxide, 3-60 g/L of an aluminum phosphate mixture and the balance of water, wherein the molar ratio of the sodium hydroxide to the silicon dioxide is 0.5-0.7, and the viscosity of the aluminum phosphate mixture is 0.15-0.3 Pa.s.
2. The silicate passivation solution as claimed in claim 1, wherein: the molar ratio of the sodium hydroxide to the silicon dioxide is 0.57-0.67.
3. The silicate passivation solution as claimed in claim 1, wherein: the viscosity of the aluminum phosphate mixture is 0.2-0.25 Pa-s.
4. The silicate passivation solution as claimed in claim 1, wherein: the raw material of the silicate passivation solution also comprises 5-60 g/L of nano oxide.
5. A silicate passivating solution according to claim 4, characterized in that: the nano oxide is any one or more of nano silicon dioxide, nano aluminum oxide and nano zinc oxide.
6. The silicate passivation solution as claimed in claim 4, wherein: the nano oxide is dopamine modified nano oxide.
7. The silicate passivation solution as claimed in claim 1, wherein: the raw material of the silicate passivation solution also comprises 1-5 g/L polydopamine microcapsule loaded with aluminum dihydrogen tripolyphosphate.
8. A method for preparing a silicate passivating solution according to any of claims 1-7, characterized by comprising the steps of:
A. dissolving sodium hydroxide in water to obtain a sodium hydroxide solution A;
B. adding silicon dioxide into a sodium hydroxide solution A to obtain a mixed solution B;
C. adding the aluminum phosphate mixture into the mixed solution B to obtain a mixed solution C;
D. and adding a passivation auxiliary agent into the mixed solution C to obtain a silicate passivation solution, wherein the passivation auxiliary agent is any one or more of a nano oxide, a dopamine modified nano oxide and a polydopamine microcapsule.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202210714133.XA CN114959675B (en) | 2022-06-23 | 2022-06-23 | Silicate passivation solution and preparation method thereof |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202210714133.XA CN114959675B (en) | 2022-06-23 | 2022-06-23 | Silicate passivation solution and preparation method thereof |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN114959675A true CN114959675A (en) | 2022-08-30 |
| CN114959675B CN114959675B (en) | 2023-10-03 |
Family
ID=82964593
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202210714133.XA Active CN114959675B (en) | 2022-06-23 | 2022-06-23 | Silicate passivation solution and preparation method thereof |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN114959675B (en) |
Citations (9)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP1172420A1 (en) * | 2000-07-12 | 2002-01-16 | Nisshin Steel Co., Ltd. | Chromium-free paint compositions and painted metal sheets |
| CN101565826A (en) * | 2009-06-03 | 2009-10-28 | 北京科技大学 | Organic and inorganic composite aluminium alloy non-chromium passivation treatment fluid |
| CN102747360A (en) * | 2012-07-05 | 2012-10-24 | 南昌航空大学 | Chromium-free passivation method for galvanized steel sheet by using molybdate/polyphosphate composite system |
| CN103014689A (en) * | 2012-12-29 | 2013-04-03 | 云南滇科涂镀层材料有限公司 | Environment-friendly galvanization, black Zn-Fe alloy passivation solution and preparation method |
| CN103805977A (en) * | 2012-11-08 | 2014-05-21 | 上海丰野表面处理剂有限公司 | Chromium-free passivation liquid for treating tin-plated steel plate |
| CN103911609A (en) * | 2013-12-20 | 2014-07-09 | 华南理工大学 | Environment-friendly silicate passivation solution for galvanization, and preparation method and application thereof |
| CN105256298A (en) * | 2015-11-02 | 2016-01-20 | 常熟风范电力设备股份有限公司 | Efficient and environment-friendly chromate-free passivation solution and preparation method thereof |
| CN112899669A (en) * | 2021-01-20 | 2021-06-04 | 昆山富维金属制品有限公司 | Nano passivation coating galvanized sheet and production process thereof |
| CN114231962A (en) * | 2021-12-16 | 2022-03-25 | 厦门华弘昌科技有限公司 | Chromium-free passivator, preparation method thereof and passivating method |
-
2022
- 2022-06-23 CN CN202210714133.XA patent/CN114959675B/en active Active
Patent Citations (9)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP1172420A1 (en) * | 2000-07-12 | 2002-01-16 | Nisshin Steel Co., Ltd. | Chromium-free paint compositions and painted metal sheets |
| CN101565826A (en) * | 2009-06-03 | 2009-10-28 | 北京科技大学 | Organic and inorganic composite aluminium alloy non-chromium passivation treatment fluid |
| CN102747360A (en) * | 2012-07-05 | 2012-10-24 | 南昌航空大学 | Chromium-free passivation method for galvanized steel sheet by using molybdate/polyphosphate composite system |
| CN103805977A (en) * | 2012-11-08 | 2014-05-21 | 上海丰野表面处理剂有限公司 | Chromium-free passivation liquid for treating tin-plated steel plate |
| CN103014689A (en) * | 2012-12-29 | 2013-04-03 | 云南滇科涂镀层材料有限公司 | Environment-friendly galvanization, black Zn-Fe alloy passivation solution and preparation method |
| CN103911609A (en) * | 2013-12-20 | 2014-07-09 | 华南理工大学 | Environment-friendly silicate passivation solution for galvanization, and preparation method and application thereof |
| CN105256298A (en) * | 2015-11-02 | 2016-01-20 | 常熟风范电力设备股份有限公司 | Efficient and environment-friendly chromate-free passivation solution and preparation method thereof |
| CN112899669A (en) * | 2021-01-20 | 2021-06-04 | 昆山富维金属制品有限公司 | Nano passivation coating galvanized sheet and production process thereof |
| CN114231962A (en) * | 2021-12-16 | 2022-03-25 | 厦门华弘昌科技有限公司 | Chromium-free passivator, preparation method thereof and passivating method |
Also Published As
| Publication number | Publication date |
|---|---|
| CN114959675B (en) | 2023-10-03 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN111684021B (en) | Corrosion protection of metal substrates | |
| US7695771B2 (en) | Process for forming a well visible non-chromate conversion coating for magnesium and magnesium alloys | |
| TW201343967A (en) | Aqueous metal surface treatment agent and metal surface treatment method using the same | |
| CN112236485A (en) | Corrosion protection of metal substrates comprising one or more 2D material sheets | |
| US10550478B2 (en) | Chromium-free conversion coating | |
| Cui et al. | Functionalized graphene oxide: Carrier for corrosion inhibitor and barrier in waterborne epoxy coatings | |
| CN112876983A (en) | Fluorine-free super-hydrophobic modified silicon dioxide composite resin coating and preparation method thereof | |
| CN113292902B (en) | Modified graphene oxide anticorrosive paint and preparation method thereof | |
| CN109517516B (en) | Certified bentonite modified waterborne polyurethane coating and preparation method thereof | |
| Xu et al. | Fabrication of organic/inorganic hybrid waterborne polyurethane coating based on CeNPs@ mTi3C2Tx composites for anti-corrosion applications | |
| Li et al. | Synthesis of stabilized dispersion covalently-jointed SiO2@ polyaniline with core-shell structure and anticorrosion performance of its hydrophobic coating for Mg-Li alloy | |
| CN101899657A (en) | Chromium-free passivating treatment agent and method for preparing same | |
| Bagale et al. | An active corrosion inhibition coating of two pack epoxy polyamide system using halloysite nanocontainer | |
| US5749946A (en) | Anticorrosive pigment preparation containing metal oxide-coated platelet adjuvant | |
| JP5122869B2 (en) | Metal surface treatment composition and aluminum-based metal surface treatment plate | |
| Leggat et al. | Adhesion of epoxy to hydrotalcite conversion coatings: II. Surface modification with ionic surfactants | |
| CN109181525B (en) | Polyaniline-silane-nano ceramic composite surface treating agent | |
| CN114959675A (en) | Silicate passivation solution and preparation method thereof | |
| CN115558915B (en) | Magnesium alloy high corrosion-resistant hydrophobic sealing agent and preparation method thereof | |
| JP6275975B2 (en) | Chrome-free chemical coating | |
| Lee et al. | Development of corrosion-resistant epoxy coating by hydrophobically surface-modified halloysite nanotubes using trimethylchlorosilane and 1, 1, 1, 3, 3, 3-hexamethyldisilazane | |
| CN113416431B (en) | Preparation method of environment-friendly anticorrosive pigment with self-repairing function | |
| CN105925970A (en) | Surface treatment agent used before metal material cathode electrophoresis coating | |
| CN115785762B (en) | Preparation of P-AT@Zn-OMMT modified epoxy resin anti-corrosive paint | |
| JP2018095969A (en) | Chromium-free conversion coating |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| GR01 | Patent grant | ||
| GR01 | Patent grant |