CN115233203A - Aluminum plate pre-color-coating chromium-free passivation solution for improving paint binding force and coating process thereof - Google Patents
Aluminum plate pre-color-coating chromium-free passivation solution for improving paint binding force and coating process thereof Download PDFInfo
- Publication number
- CN115233203A CN115233203A CN202210900823.4A CN202210900823A CN115233203A CN 115233203 A CN115233203 A CN 115233203A CN 202210900823 A CN202210900823 A CN 202210900823A CN 115233203 A CN115233203 A CN 115233203A
- Authority
- CN
- China
- Prior art keywords
- aluminum plate
- stirring
- dropwise adding
- chromium
- parts
- 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.)
- Withdrawn
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
- C23C22/02—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 non-aqueous solutions
-
- C—CHEMISTRY; METALLURGY
- C01—INORGANIC CHEMISTRY
- C01B—NON-METALLIC ELEMENTS; COMPOUNDS THEREOF; METALLOIDS OR COMPOUNDS THEREOF NOT COVERED BY SUBCLASS C01C
- C01B32/00—Carbon; Compounds thereof
- C01B32/15—Nano-sized carbon materials
- C01B32/182—Graphene
- C01B32/184—Preparation
-
- C—CHEMISTRY; METALLURGY
- C01—INORGANIC CHEMISTRY
- C01B—NON-METALLIC ELEMENTS; COMPOUNDS THEREOF; METALLOIDS OR COMPOUNDS THEREOF NOT COVERED BY SUBCLASS C01C
- C01B32/00—Carbon; Compounds thereof
- C01B32/15—Nano-sized carbon materials
- C01B32/182—Graphene
- C01B32/198—Graphene oxide
-
- 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
- C23C22/73—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 characterised by the process
- C23C22/76—Applying the liquid by spraying
Landscapes
- Chemical & Material Sciences (AREA)
- Organic Chemistry (AREA)
- Engineering & Computer Science (AREA)
- Materials Engineering (AREA)
- Nanotechnology (AREA)
- Inorganic Chemistry (AREA)
- General Chemical & Material Sciences (AREA)
- Chemical Kinetics & Catalysis (AREA)
- Mechanical Engineering (AREA)
- Metallurgy (AREA)
- Paints Or Removers (AREA)
Abstract
The invention relates to the field of a purified liquid, which is used for solving the problems that the existing passivation liquid contains chromium, which causes serious damage to the environment and the health of people, has poor corrosion resistance and can not effectively protect an aluminum plate, in particular to a chromium-free passivation liquid before color coating of the aluminum plate for improving the bonding force of paint and a coating process thereof; in the process, the corrosion resistance of the aluminum plate can be improved by adding the high-dispersion graphene into the chromium-free passivation solution before color coating of the aluminum plate, so that the aluminum plate can be attached to the aluminum plate for a long time, the aluminum plate is prevented from falling off, paint is easily sprayed on the aluminum plate, the binding force between the paint and the aluminum plate is improved, and the aluminum plate is well protected.
Description
Technical Field
The invention relates to the field of purified liquid, in particular to a chromium-free passivation solution for improving paint binding force before color coating of an aluminum plate and a coating process thereof.
Background
The passivating solution is a solution capable of making the metal surface into a passive state, and is generally used for the post-plating treatment of zinc plating, cadmium plating and other plating layers, and aims to form a surface state capable of preventing the normal reaction of metal on the plating layer surface, improve the corrosion resistance of the plating layer and improve the product appearance. The aluminum material has the advantages of small specific gravity, good heat conduction and electric conductivity, strong light reflection, easy processing and forming, excellent physical and chemical properties and the like, is low in price, is widely applied to aerospace, transportation, light industry building materials and other parts, and is an alloy with the widest application and the largest use amount in light alloys. Then, when the aluminum material is used in humid environment containing industrial gas, fuel gas, salt, dust and other environments, the aluminum material is easy to be damaged in the forms of pitting corrosion, crevice corrosion, stress corrosion, corrosion fatigue and the like, and the continuous use of the aluminum material is influenced. Therefore, surface treatment of aluminum materials is one of effective ways to expand the range of applications and extend the service life thereof.
The chromate passivation treatment can significantly improve the corrosion resistance of the surface of the aluminum alloy, and the generated passivation film has good adhesion to the coating and low cost, so the chromate passivation treatment has been widely used in a plurality of fields. Chromate, then, is extremely toxic and causes serious harm to the environment and human health. Therefore, the use of chromic acid is severely limited, and the research and development of non-toxic or low-toxic passivation solutions to replace the complex acid salt passivation process is a development trend in the field of passivation solutions.
How to improve the problems that the existing passivation solution contains chromium, which causes serious damage to the environment and the health of people, has poor corrosion resistance and can not effectively protect an aluminum plate is the key of the invention, therefore, a chromium-free passivation solution before color coating of the aluminum plate and a coating process thereof for improving the bonding force of paint are urgently needed to solve the problems.
Disclosure of Invention
In order to overcome the technical problems, the invention aims to provide the chromium-free passivation solution before color coating of the aluminum plate for improving the paint binding force and the coating process thereof: the method comprises the steps of uniformly mixing styrene-acrylic emulsion, epoxy resin, high-dispersion graphene, a wetting dispersant, a defoaming agent and propylene glycol methyl ether acetate to obtain the aluminum plate pre-color-coating chromium-free passivation solution for improving the paint binding force, cleaning the surface of an aluminum plate to be sprayed with a sodium hydroxide aqueous solution with the mass fraction of 5%, cleaning with tap water, cooling to dry the surface, and spraying the aluminum plate pre-color-coating chromium-free passivation solution on the cleaned surface of the aluminum plate by using a paint spraying gun.
The purpose of the invention can be realized by the following technical scheme:
the chromium-free passivation solution for the aluminum plate before color coating for improving the paint binding force comprises the following components in parts by weight:
40-50 parts of styrene-acrylic emulsion, 20-40 parts of epoxy resin, 5-25 parts of high dispersion graphene, 1-5 parts of wetting dispersant, 1-3 parts of defoamer and 20-50 parts of propylene glycol monomethyl ether acetate:
the high-dispersion graphene is prepared by the following steps:
a1: adding crystalline flake graphite, concentrated sulfuric acid and sodium nitrate into a three-neck flask provided with a stirrer, a thermometer and a constant-pressure dropping funnel, stirring for 40-60min under the conditions that the temperature is 0-5 ℃ and the stirring speed is 350-450r/min, then adding potassium permanganate, continuously stirring and reacting for 1-1.5h, then heating to 35-40 ℃, continuously stirring and reacting for 40-60min, then dropwise adding deionized water while stirring, controlling the dropwise adding speed to be 1-2 drops/s, continuously stirring and reacting for 15-20min under the conditions that the temperature is 98-100 ℃ after dropwise adding, pouring a reaction product into ice water after the reaction is finished, then adding hydrogen peroxide, continuously stirring and reacting for 25-30min, then sequentially washing with hydrochloric acid solution and distilled water for 2-3 times, then centrifuging, placing a precipitate into a vacuum drying oven, and drying for 6-8h under the condition that the temperature is 55-60 ℃ to obtain graphene oxide;
a2: adding tridecafluorooctane, chloropropene, tetrabutylammonium bromide and carbon dichloride into a three-neck flask provided with a stirrer, a thermometer and a constant-pressure dropping funnel, dropwise adding a sodium hydroxide solution under the conditions that the temperature is 20-25 ℃ and the stirring rate is 350-450r/min, controlling the dropwise adding rate to be 1-2 drops/s, continuously stirring and reacting for 20-30 hours under the condition that the temperature is increased to 40-45 ℃ after the dropwise adding is finished, pouring a reaction product into ice water after the reaction is finished, separating out a precipitate, then carrying out vacuum filtration, standing and layering a filtrate, washing an organic phase for 2-3 times with a hydrochloric acid solution and a saturated salt solution, then drying with anhydrous sodium sulfate, then carrying out reduced pressure distillation, and collecting a fraction with the pressure of 3.75kPa and the temperature of 80 ℃ to obtain an intermediate 1;
a3: adding the intermediate 1, toluene and a platinum-carbon catalyst into a three-neck flask provided with a stirrer, a thermometer, a gas-guide tube and a constant-pressure dropping funnel, introducing nitrogen for protection, stirring and dropwise adding methyl dichlorosilane under the conditions that the temperature is 70-75 ℃ and the stirring speed is 350-450r/min, controlling the dropwise adding speed to be 1-2 drops/s, continuously stirring and reacting for 3-4 hours after the dropwise adding is finished, performing rotary evaporation and evaporation on a reaction product after the reaction is finished to remove a solvent and unreacted methyl dichlorosilane, then performing reduced pressure distillation, and collecting a fraction with the pressure of 3.75kPa and the temperature of 132 ℃ to obtain an intermediate 2;
a4: adding absolute ethyl alcohol and n-hexane into a three-neck flask provided with a stirrer, a thermometer, a gas-guide tube and a constant-pressure dropping funnel, introducing nitrogen for protection, dropwise adding the intermediate 2 while stirring under the conditions that the temperature is 70-75 ℃ and the stirring speed is 350-450r/min, controlling the dropwise adding speed to be 1-2 drops/s, continuously stirring for reaction for 3-4h after the dropwise adding is finished, removing the solvent and unreacted absolute ethyl alcohol by rotary evaporation of a reaction product after the reaction is finished, and then adjusting the pH to 7 by using sodium ethoxide to obtain an intermediate 3;
a5: adding graphene oxide and deionized water into a three-neck flask provided with a stirrer, a thermometer and a constant-pressure dropping funnel, performing ultrasonic dispersion for 30-40min under the condition of ultrasonic frequency of 45-55kHz, then adding an intermediate 3, stirring for 3-4h under the conditions that the temperature is 20-25 ℃ and the stirring speed is 350-450r/min, then dropwise adding concentrated ammonia water while stirring, controlling the dropwise adding speed to be 1-2 drops/s, continuously stirring and reacting for 3-4h under the condition that the temperature is increased to 40-45 ℃ after dropwise adding is finished, centrifuging a reaction product after the reaction is finished, washing precipitates for 2-3 times by using distilled water and absolute ethyl alcohol in sequence, then placing the reaction product into a vacuum drying box, and drying for 6-8h under the condition that the temperature is 55-60 ℃ to obtain the high-dispersion graphene.
As a further scheme of the invention: the dosage ratio of the crystalline flake graphite, concentrated sulfuric acid, sodium nitrate, potassium permanganate, deionized water and hydrogen peroxide in the step A1 is 1g:20-25mL:0.5g:3g:50-60mL:10-15mL, the mass fraction of the hydrogen peroxide is 30%, and the mass fraction of the hydrochloric acid solution is 5%.
As a further scheme of the invention: the dosage ratio of the solution of the tridecafluorooctanol, the chloropropene, the tetrabutylammonium bromide, the carbon dichloride and the sodium hydroxide in the step A2 is 0.1mol:0.11-0.13mol:2.2-2.5g:30-40mL:15-20mL, the mass fraction of the sodium hydroxide solution is 35-40%, and the molar concentration of the hydrochloric acid solution is 1mol/L.
As a further scheme of the invention: the dosage ratio of the intermediate 1, the toluene, the platinum carbon catalyst and the methyl dichlorosilane in the step A3 is 0.1mol:30-40mL:0.05-0.1g:0.1-0.13mol.
As a further scheme of the invention: the dosage ratio of the absolute ethyl alcohol, the normal hexane and the intermediate 2 in the step A4 is 0.22-0.24mol:40-50mL:0.1mol.
As a further scheme of the invention: the dosage ratio of the graphene oxide, the deionized water, the intermediate 3 and the strong ammonia water in the step A5 is 1g:100-120mL:1.5-5.5g:6-10mL, and the mass fraction of the strong ammonia water is 25-27%.
As a further scheme of the invention: the coating process of the chromium-free passivation solution before the color coating of the aluminum plate for improving the paint binding force comprises the following steps:
the method comprises the following steps: weighing 40-50 parts of styrene-acrylic emulsion, 20-40 parts of epoxy resin, 5-25 parts of high-dispersion graphene, 1-5 parts of wetting dispersant, 1-3 parts of defoaming agent and 20-50 parts of propylene glycol methyl ether acetate according to parts by weight for later use;
step two: uniformly mixing styrene-acrylic emulsion, epoxy resin, high-dispersion graphene, a wetting dispersant, a defoaming agent and propylene glycol methyl ether acetate to obtain the chromium-free passivation solution before color coating of the aluminum plate for improving the binding force of the paint;
step three: cleaning the surface of an aluminum plate to be sprayed by using a sodium hydroxide aqueous solution with the mass fraction of 5%, then cleaning by using tap water, and cooling in the shade until the surface is dried;
step four: and spraying the chromium-free passivation solution on the surface of the cleaned aluminum plate by using a paint spray gun, controlling the spraying thickness to be 0.1-0.2mm, and drying in the shade for 1-3h.
As a further scheme of the invention: the epoxy resin is one of epoxy resin E51 and epoxy resin E44, the wetting dispersant is wetting dispersant BD-8140A, and the defoaming agent is defoaming agent BYK-024.
The invention has the beneficial effects that:
the invention relates to a chromium-free passivation solution before color coating of an aluminum plate for improving paint binding force and a coating process thereof.A styrene-acrylic emulsion, epoxy resin, high-dispersion graphene, a wetting dispersant, a defoaming agent and propylene glycol methyl ether acetate are uniformly mixed to obtain the chromium-free passivation solution before color coating of the aluminum plate for improving paint binding force, the surface of the aluminum plate to be sprayed is cleaned by using a sodium hydroxide aqueous solution with the mass fraction of 5%, then is cleaned by using tap water, is cooled in the shade until the surface is dried, and is sprayed on the surface of the cleaned aluminum plate by using a paint gun; in the process, the corrosion resistance of the aluminum plate can be improved by adding the high-dispersion graphene into the chromium-free passivation solution before color coating of the aluminum plate, so that the aluminum plate can be attached to the aluminum plate for a long time, the aluminum plate is prevented from falling off, paint is easy to spray on the aluminum plate, the binding force between the paint and the aluminum plate is improved, and the aluminum plate is well protected;
firstly preparing high-dispersion graphene in the process of preparing a chromium-free passivation solution before color coating of an aluminum plate, firstly oxidizing the high-dispersion graphene by using crystalline flake graphite to form graphene oxide, then carrying out nucleophilic substitution reaction on hydroxyl on tridecafluorooctanol and chlorine atoms on chloropropene to obtain an intermediate 1 containing alkenyl and a large number of C-F bonds, then carrying out hydrosilylation reaction on the alkenyl on the intermediate 1 and Si-H on methyldichlorosilane to generate an intermediate 2, then carrying out alcoholysis reaction on the intermediate 2 and absolute ethyl alcohol to convert Si-Cl into Si-O-C 2 H 5 Obtaining an intermediate 3, hydrolyzing the intermediate 3 to form silanol, and then carrying out chemical reaction on the silanol and active groups at the edge of the graphene oxide, namely hydroxyl, carboxyl and epoxy groups, so as to graft the silanol onto the surface of the graphene oxide to obtain the high-dispersion graphene, wherein a large number of Si-O long chains are grafted on the high-dispersion graphene to improve the dispersibility of the high-dispersion graphene in a chromium-free passivation solution before color coating of an aluminum plate, and the introduced C-F bond endows the aluminum plate with no chromium before color coatingThe good chemical resistance ability of chromium passivation solution shows good corrosion resistance, and graphite alkene hydrophobic property is good moreover, can effectual prevention corrosion factor infiltration and aluminum plate contact to its corrosion resistance of further promotion, thereby can carry out effectual protection to aluminum plate.
Detailed Description
The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.
Example 1:
the embodiment is a preparation method of high-dispersion graphene, which includes the following steps:
a1: adding 1g of flake graphite, 20mL of concentrated sulfuric acid and 0.5g of sodium nitrate into a three-neck flask provided with a stirrer, a thermometer and a constant-pressure dropping funnel, stirring for 40min under the conditions that the temperature is 0 ℃ and the stirring speed is 350r/min, then adding 3g of potassium permanganate, continuously stirring for reaction for 1h, then heating to 35 ℃, continuously stirring for reaction for 40min, dropwise adding 50mL of deionized water while stirring, controlling the dropping speed to be 1 drop/s, continuously stirring for reaction for 15min under the conditions that the temperature is 98 ℃ after the dropwise adding is finished, pouring a reaction product into ice water after the reaction is finished, then adding 10mL of 30 mass percent hydrogen peroxide, continuously stirring for reaction for 25min, then sequentially washing for 2 times with 5 mass percent hydrochloric acid solution and distilled water, then centrifuging, placing a precipitate into a vacuum drying oven, and drying for 6h under the temperature of 55 ℃ to obtain graphene oxide;
a2: adding 0.1mol of tridecafluorooctanol, 0.11mol of chloropropene, 2.2g of tetrabutylammonium bromide and 30mL of carbon dichloride into a three-neck flask provided with a stirrer, a thermometer and a constant-pressure dropping funnel, dropwise adding 15mL of sodium hydroxide solution with the mass fraction of 35% while stirring at the temperature of 20 ℃ and the stirring rate of 350r/min, controlling the dropwise adding rate to be 1 drop/s, continuously stirring and reacting for 20 hours under the condition of heating to 40 ℃ after the dropwise adding is finished, pouring a reaction product into ice water after the reaction is finished, separating out a precipitate, carrying out vacuum filtration, standing and layering a filtrate, washing an organic phase for 2 times by using a hydrochloric acid solution with the molar concentration of 1mol/L and saturated common salt solution in sequence, drying by using anhydrous sodium sulfate, carrying out reduced pressure distillation, and collecting a fraction with the pressure of 3.75kPa and the temperature of 80 ℃ to obtain an intermediate 1;
a3: adding 0.1mol of the intermediate 1, 30mL of toluene and 0.05g of platinum-carbon catalyst into a three-neck flask provided with a stirrer, a thermometer, a gas guide tube and a constant-pressure dropping funnel, introducing nitrogen for protection, adding 0.1mol of methyldichlorosilane dropwise while stirring under the conditions that the temperature is 70 ℃ and the stirring speed is 350r/min, controlling the dropwise adding speed to be 1 drop/s, continuing stirring for reaction for 3 hours after the dropwise adding is finished, removing the solvent and unreacted methyldichlorosilane by rotary evaporation and evaporation of a reaction product after the reaction is finished, then carrying out reduced pressure distillation, collecting a fraction with the pressure of 3.75kPa and the temperature of 132 ℃, and obtaining an intermediate 2;
a4: adding 0.22mol of absolute ethyl alcohol and 40mL of n-hexane into a three-neck flask provided with a stirrer, a thermometer, a gas guide tube and a constant-pressure dropping funnel, introducing nitrogen for protection, dropwise adding 0.1mol of the intermediate 2 while stirring under the conditions that the temperature is 70 ℃ and the stirring speed is 350r/min, controlling the dropwise adding speed to be 1 drop/s, continuing stirring for reaction for 3 hours after the dropwise adding is finished, removing the solvent and unreacted absolute ethyl alcohol by rotary evaporation of a reaction product after the reaction is finished, and then adjusting the pH to be 7 by using sodium ethoxide to obtain an intermediate 3;
a5: adding 1g of graphene oxide and 100mL of deionized water into a three-neck flask provided with a stirrer, a thermometer and a constant-pressure dropping funnel, ultrasonically dispersing for 30min under the condition that the ultrasonic frequency is 45kHz, then adding 1.5g of intermediate 3, stirring for 3h under the conditions that the temperature is 20 ℃ and the stirring speed is 350r/min, then dropwise adding 6mL of 25% concentrated ammonia water while stirring, controlling the dropwise adding speed to be 1 drop/s, continuously stirring and reacting for 3h under the condition that the temperature is raised to 40 ℃ after the dropwise adding is finished, centrifuging a reaction product after the reaction is finished, washing precipitates for 2 times by using distilled water and absolute ethyl alcohol in sequence, then placing the precipitates in a vacuum drying box, and drying for 6h under the condition that the temperature is 55 ℃ to obtain the high-dispersion graphene.
Example 2:
the embodiment is a preparation method of high-dispersion graphene, which includes the following steps:
a1: adding 1g of flake graphite, 25mL of concentrated sulfuric acid and 0.5g of sodium nitrate into a three-neck flask provided with a stirrer, a thermometer and a constant-pressure dropping funnel, stirring for 60min under the conditions that the temperature is 5 ℃ and the stirring speed is 450r/min, then adding 3g of potassium permanganate, continuously stirring for reaction for 1.5h, then heating to 40 ℃, continuously stirring for reaction for 60min, then dropwise adding 60mL of deionized water while stirring, controlling the dropwise adding speed to be 2 drops/s, heating to 100 ℃ after the dropwise adding is finished, continuously stirring for reaction for 20min, pouring a reaction product into ice water after the reaction is finished, then adding 15mL of hydrogen peroxide with the mass fraction of 30%, continuously stirring for reaction for 30min, then sequentially washing with 5% hydrochloric acid solution and distilled water for 3 times, then centrifuging, placing a precipitate into a vacuum drying oven, and drying for 8h under the temperature of 60 ℃ to obtain graphene oxide;
a2: adding 0.1mol of tridecafluorooctanol, 0.13mol of chloropropene, 2.5g of tetrabutylammonium bromide and 40mL of carbon dichloride into a three-neck flask provided with a stirrer, a thermometer and a constant-pressure dropping funnel, dropwise adding 20mL of a sodium hydroxide solution with the mass fraction of 40% while stirring at the temperature of 25 ℃ and the stirring rate of 450r/min, controlling the dropwise adding rate to be 2 drops/s, continuously stirring and reacting for 30 hours under the condition of heating to 45 ℃ after the dropwise adding is finished, pouring a reaction product into ice water after the reaction is finished, precipitating and precipitating, then carrying out vacuum filtration, standing and layering a filtrate, washing an organic phase for 3 times by using a hydrochloric acid solution with the molar concentration of 1mol/L and a saturated saline solution in sequence, drying by using anhydrous sodium sulfate, then carrying out reduced pressure distillation, and collecting a fraction with the pressure of 3.75kPa and the temperature of 80 ℃ to obtain an intermediate 1;
a3: adding 0.1mol of intermediate 1, 40mL of toluene and 0.1g of platinum-carbon catalyst into a three-neck flask provided with a stirrer, a thermometer, a gas-guide tube and a constant-pressure dropping funnel, introducing nitrogen for protection, adding 0.13mol of methyl dichlorosilane dropwise while stirring under the conditions that the temperature is 75 ℃ and the stirring speed is 450r/min, controlling the dropwise adding speed to be 2 drops/s, continuing stirring for reaction for 4 hours after the dropwise adding is finished, removing the solvent and unreacted methyl dichlorosilane by rotary evaporation and evaporation of a reaction product after the reaction is finished, then carrying out reduced pressure distillation, collecting a fraction with the pressure of 3.75kPa and the temperature of 132 ℃, and obtaining an intermediate 2;
a4: adding 0.24mol of absolute ethyl alcohol and 50mL of n-hexane into a three-neck flask provided with a stirrer, a thermometer, a gas guide tube and a constant-pressure dropping funnel, introducing nitrogen for protection, dropwise adding 0.1mol of intermediate 2 while stirring under the conditions that the temperature is 75 ℃ and the stirring speed is 450r/min, controlling the dropwise adding speed to be 2 drops/s, continuing stirring for reaction for 4 hours after the dropwise adding is finished, removing the solvent and unreacted absolute ethyl alcohol by rotary evaporation of a reaction product after the reaction is finished, and then adjusting the pH to 7 by using sodium ethoxide to obtain an intermediate 3;
a5: adding 1g of graphene oxide and 120mL of deionized water into a three-neck flask provided with a stirrer, a thermometer and a constant-pressure dropping funnel, performing ultrasonic dispersion for 40min under the condition that the ultrasonic frequency is 55kHz, then adding 5.5g of intermediate 3, stirring for 4h under the conditions that the temperature is 25 ℃ and the stirring speed is 450r/min, then dropwise adding 10mL of 27 mass percent concentrated ammonia water while stirring, controlling the dropwise adding speed to be 2 drops/s, continuing stirring and reacting for 4h under the condition that the temperature is raised to 45 ℃ after the dropwise adding is finished, centrifuging a reaction product after the reaction is finished, washing the precipitate for 3 times by distilled water and absolute ethyl alcohol in sequence, then placing the precipitate into a vacuum drying box, and drying for 8h under the condition that the temperature is 60 ℃ to obtain the high-dispersion graphene.
Example 3:
the embodiment is a coating process of a chromium-free passivation solution before color coating of an aluminum plate for improving the paint binding force, which comprises the following steps:
the method comprises the following steps: weighing 40 parts of styrene-acrylic emulsion, 20 parts of epoxy resin, 5 parts of high dispersion graphene from example 1, 1 part of wetting dispersant, 1 part of defoaming agent and 20 parts of propylene glycol methyl ether acetate according to parts by weight for later use; the epoxy resin is epoxy resin E51, the wetting dispersant is wetting dispersant BD-8140A, and the defoaming agent is defoaming agent BYK-024;
step two: uniformly mixing styrene-acrylic emulsion, epoxy resin, high-dispersion graphene, a wetting dispersant, a defoaming agent and propylene glycol methyl ether acetate to obtain the chromium-free passivation solution before color coating of the aluminum plate for improving the binding force of the paint;
step three: cleaning the surface of an aluminum plate to be sprayed by using a sodium hydroxide aqueous solution with the mass fraction of 5%, then cleaning by using tap water, and cooling in the shade until the surface is dried;
step four: and (3) spraying the chromium-free passivation solution on the surface of the cleaned aluminum plate by using a paint spray gun before color coating of the aluminum plate, controlling the spraying thickness to be 0.1mm, and drying in the shade for 1h.
Example 4:
the embodiment is a coating process of a chromium-free passivation solution before color coating of an aluminum plate for improving the paint binding force, which comprises the following steps:
the method comprises the following steps: weighing 50 parts of styrene-acrylic emulsion, 40 parts of epoxy resin, 25 parts of high-dispersion graphene from example 2, 5 parts of wetting dispersant, 3 parts of defoaming agent and 50 parts of propylene glycol methyl ether acetate according to parts by weight for later use; the epoxy resin is epoxy resin E44, the wetting dispersant is wetting dispersant BD-8140A, and the defoaming agent is defoaming agent BYK-024;
step two: uniformly mixing styrene-acrylic emulsion, epoxy resin, high-dispersion graphene, a wetting dispersant, a defoaming agent and propylene glycol methyl ether acetate to obtain the chromium-free passivation solution before color coating of the aluminum plate for improving the binding force of the paint;
step three: cleaning the surface of an aluminum plate to be sprayed by using a sodium hydroxide aqueous solution with the mass fraction of 5%, then cleaning by using tap water, and cooling in the shade until the surface is dried;
step four: and (3) spraying the chromium-free passivation solution on the surface of the cleaned aluminum plate by using a paint spray gun before color coating of the aluminum plate, controlling the spraying thickness to be 0.2mm, and drying in the shade for 3 hours.
Comparative example 1:
this comparative example differs from example 4 in that no highly dispersed graphene is added.
Comparative example 2:
this comparative example differs from example 4 in that graphene oxide is used instead of highly dispersed graphene.
The chromium-free passivation solution before color coating of the aluminum plates of examples 3 to 4 and comparative examples 1 to 2 was spray-coated on the surface of the cleaned aluminum plate using a paint spray gun, and then the aluminum plate was tested, and the test results are shown in the following table:
| sample (I) | Example 3 | Example 4 | Comparative example 1 | Comparative example 2 |
| Neutral salt spray test, rust area% | 1 | 0 | 9 | 5 |
| Natural rusting experiment, days without rusting, d | 56 | 74 | 13 | 24 |
| Grade of passive film adhesion | 0 | 0 | 1 | 0 |
Referring to the data in the table, according to the comparison between the example 4 and the comparative examples 1-2, it can be known that the corrosion resistance of the chromium-free passivation solution before color coating of the aluminum plate can be effectively improved by adding the graphene oxide and the highly dispersed graphene, the passivation film has good adhesive force, long-acting protection is performed on the aluminum material, and the highly dispersed graphene has a better effect on improving the chromium-free passivation solution before color coating of the aluminum plate.
In the description herein, references to the description of "one embodiment," "an example," "a specific example" or the like are intended to mean that a particular feature, structure, material, or characteristic described in connection with the embodiment or example is included in at least one embodiment or example of the invention. In this specification, the schematic representations of the terms used above do not necessarily refer to the same embodiment or example. Furthermore, the particular features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples.
The foregoing is illustrative and explanatory only, and it will be appreciated by those skilled in the art that various modifications, additions and substitutions can be made to the embodiments described without departing from the scope of the invention as defined in the appended claims.
Claims (8)
1. The chromium-free passivation solution for the aluminum plate before color coating for improving the paint binding force is characterized by comprising the following components in parts by weight:
40-50 parts of styrene-acrylic emulsion, 20-40 parts of epoxy resin, 5-25 parts of high-dispersion graphene, 1-5 parts of wetting dispersant, 1-3 parts of defoaming agent and 20-50 parts of propylene glycol methyl ether acetate:
the high-dispersion graphene is prepared by the following steps:
a1: adding crystalline flake graphite, concentrated sulfuric acid and sodium nitrate into a three-neck flask provided with a stirrer, a thermometer and a constant-pressure dropping funnel, stirring for 40-60min under the conditions that the temperature is 0-5 ℃ and the stirring speed is 350-450r/min, then adding potassium permanganate, continuously stirring and reacting for 1-1.5h, then heating to 35-40 ℃, continuously stirring and reacting for 40-60min, then dropwise adding deionized water while stirring, controlling the dropwise adding speed to be 1-2 drops/s, continuously stirring and reacting for 15-20min under the conditions that the temperature is 98-100 ℃ after dropwise adding, pouring a reaction product into ice water after the reaction is finished, then adding hydrogen peroxide, continuously stirring and reacting for 25-30min, then sequentially washing with hydrochloric acid solution and distilled water for 2-3 times, then centrifuging, placing a precipitate into a vacuum drying oven, and drying for 6-8h under the condition that the temperature is 55-60 ℃ to obtain graphene oxide;
a2: adding tridecafluorooctane, chloropropene, tetrabutylammonium bromide and carbon dichloride into a three-neck flask provided with a stirrer, a thermometer and a constant-pressure dropping funnel, dropwise adding a sodium hydroxide solution under the conditions that the temperature is 20-25 ℃ and the stirring rate is 350-450r/min, controlling the dropwise adding rate to be 1-2 drops/s, continuously stirring and reacting for 20-30 hours under the condition that the temperature is increased to 40-45 ℃ after the dropwise adding is finished, pouring a reaction product into ice water after the reaction is finished, separating out a precipitate, then carrying out vacuum filtration, standing and layering a filtrate, washing an organic phase for 2-3 times with a hydrochloric acid solution and a saturated salt solution, then drying with anhydrous sodium sulfate, then carrying out reduced pressure distillation, and collecting a fraction with the pressure of 3.75kPa and the temperature of 80 ℃ to obtain an intermediate 1;
a3: adding the intermediate 1, toluene and a platinum-carbon catalyst into a three-neck flask provided with a stirrer, a thermometer, a gas-guide tube and a constant-pressure dropping funnel, introducing nitrogen for protection, stirring and dropwise adding methyl dichlorosilane under the conditions that the temperature is 70-75 ℃ and the stirring speed is 350-450r/min, controlling the dropwise adding speed to be 1-2 drops/s, continuously stirring and reacting for 3-4 hours after the dropwise adding is finished, performing rotary evaporation and evaporation on a reaction product after the reaction is finished to remove a solvent and unreacted methyl dichlorosilane, then performing reduced pressure distillation, and collecting a fraction with the pressure of 3.75kPa and the temperature of 132 ℃ to obtain an intermediate 2;
a4: adding absolute ethyl alcohol and n-hexane into a three-neck flask provided with a stirrer, a thermometer, a gas-guide tube and a constant-pressure dropping funnel, introducing nitrogen for protection, dropwise adding the intermediate 2 while stirring under the conditions that the temperature is 70-75 ℃ and the stirring speed is 350-450r/min, controlling the dropwise adding speed to be 1-2 drops/s, continuously stirring for reaction for 3-4h after the dropwise adding is finished, removing the solvent and unreacted absolute ethyl alcohol by rotary evaporation of a reaction product after the reaction is finished, and then adjusting the pH to 7 by using sodium ethoxide to obtain an intermediate 3;
a5: adding graphene oxide and deionized water into a three-neck flask provided with a stirrer, a thermometer and a constant-pressure dropping funnel, performing ultrasonic dispersion for 30-40min under the condition of ultrasonic frequency of 45-55kHz, then adding an intermediate 3, stirring for 3-4h under the conditions that the temperature is 20-25 ℃ and the stirring speed is 350-450r/min, then dropwise adding concentrated ammonia water while stirring, controlling the dropwise adding speed to be 1-2 drops/s, continuously stirring and reacting for 3-4h under the condition that the temperature is increased to 40-45 ℃ after dropwise adding is finished, centrifuging a reaction product after the reaction is finished, washing precipitates for 2-3 times by using distilled water and absolute ethyl alcohol in sequence, then placing the reaction product into a vacuum drying box, and drying for 6-8h under the condition that the temperature is 55-60 ℃ to obtain the high-dispersion graphene.
2. The aluminum plate pre-color-coating chromium-free passivation solution for improving the paint bonding force according to claim 1, wherein the dosage ratio of the crystalline flake graphite, concentrated sulfuric acid, sodium nitrate, potassium permanganate, deionized water and hydrogen peroxide in the step A1 is 1g:20-25mL:0.5g:3g:50-60mL:10-15mL, wherein the mass fraction of the hydrogen peroxide is 30%, and the mass fraction of the hydrochloric acid solution is 5%.
3. The chrome-free passivation solution for aluminum plates before color coating for improving paint binding force according to claim 1, wherein the dosage ratio of the solutions of tridecafluorooctanol, chloropropene, tetrabutylammonium bromide, carbon dichloride and sodium hydroxide in the step A2 is 0.1mol:0.11-0.13mol:2.2-2.5g:30-40mL:15-20mL, the mass fraction of the sodium hydroxide solution is 35-40%, and the molar concentration of the hydrochloric acid solution is 1mol/L.
4. The chromium-free passivation solution for aluminum plate before color coating for improving paint binding force according to claim 1, wherein the amount ratio of the intermediate 1, toluene, platinum carbon catalyst and methyl dichlorosilane in step A3 is 0.1mol:30-40mL:0.05-0.1g:0.1-0.13mol.
5. The aluminum plate color-coating pre-chromium-free passivation solution for improving the paint binding force according to claim 1, wherein the dosage ratio of the absolute ethyl alcohol, the normal hexane and the intermediate 2 in the step A4 is 0.22-0.24mol:40-50mL:0.1mol.
6. The aluminum plate pre-color-coating chromium-free passivation solution for improving the paint bonding force according to claim 1, wherein the dosage ratio of the graphene oxide, the deionized water, the intermediate 3 and the concentrated ammonia water in the step A5 is 1g:100-120mL:1.5-5.5g:6-10mL, and the mass fraction of the strong ammonia water is 25-27%.
7. The coating process of the chromium-free passivation solution before color coating of the aluminum plate for improving the paint binding force is characterized by comprising the following steps of:
the method comprises the following steps: weighing 40-50 parts of styrene-acrylic emulsion, 20-40 parts of epoxy resin, 5-25 parts of high-dispersion graphene, 1-5 parts of wetting dispersant, 1-3 parts of defoaming agent and 20-50 parts of propylene glycol methyl ether acetate according to parts by weight for later use;
step two: uniformly mixing styrene-acrylic emulsion, epoxy resin, high-dispersion graphene, a wetting dispersant, a defoaming agent and propylene glycol methyl ether acetate to obtain the chromium-free passivation solution before color coating of the aluminum plate for improving the binding force of the paint;
step three: cleaning the surface of an aluminum plate to be sprayed by using a sodium hydroxide aqueous solution with the mass fraction of 5%, then cleaning by using tap water, and cooling in the shade until the surface is dried;
step four: and spraying the chromium-free passivation solution on the surface of the cleaned aluminum plate by using a paint spraying gun before color coating of the aluminum plate, controlling the spraying thickness to be 0.1-0.2mm, and drying in the shade for 1-3h.
8. The coating process of the chromium-free passivation solution before color coating of the aluminum plate for improving the paint binding force as claimed in claim 7, wherein the epoxy resin is one of epoxy resin E51 and epoxy resin E44, the wetting and dispersing agent is wetting and dispersing agent BD-8140A, and the defoaming agent is defoaming agent BYK-024.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202210900823.4A CN115233203A (en) | 2022-07-28 | 2022-07-28 | Aluminum plate pre-color-coating chromium-free passivation solution for improving paint binding force and coating process thereof |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202210900823.4A CN115233203A (en) | 2022-07-28 | 2022-07-28 | Aluminum plate pre-color-coating chromium-free passivation solution for improving paint binding force and coating process thereof |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN115233203A true CN115233203A (en) | 2022-10-25 |
Family
ID=83676708
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202210900823.4A Withdrawn CN115233203A (en) | 2022-07-28 | 2022-07-28 | Aluminum plate pre-color-coating chromium-free passivation solution for improving paint binding force and coating process thereof |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN115233203A (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN116179031A (en) * | 2022-12-19 | 2023-05-30 | 北京东方雨虹防水技术股份有限公司 | Graphene passivation solution, preparation method thereof, lithium battery soft-coated aluminum-plastic film and lithium battery |
-
2022
- 2022-07-28 CN CN202210900823.4A patent/CN115233203A/en not_active Withdrawn
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN116179031A (en) * | 2022-12-19 | 2023-05-30 | 北京东方雨虹防水技术股份有限公司 | Graphene passivation solution, preparation method thereof, lithium battery soft-coated aluminum-plastic film and lithium battery |
| CN116179031B (en) * | 2022-12-19 | 2024-05-14 | 北京东方雨虹防水技术股份有限公司 | Graphene passivation solution, preparation method thereof, lithium battery soft-coated aluminum-plastic film and lithium battery |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN100473469C (en) | Corrosion protection on metals | |
| CN106011816B (en) | A kind of graphene-based film agent | |
| CN105441920B (en) | With silane coupling agent metal conditioner as main component and preparation method thereof | |
| TWI529261B (en) | Surface-treatment liquid for zinc or zinc alloy coated steel sheet, and zinc or zinc alloy coated steel sheet and method for manufacturing the same | |
| CN106995643A (en) | A kind of water paint of graphene-containing/zinc-aluminum gavite nano-complex and preparation method thereof | |
| CN101717930A (en) | Environment-friendly nano water-based silane treatment agent capable of improving anti-corrosion performance of metal surface | |
| WO2012043864A1 (en) | Hot-dip galvanized steel sheet and manufacturing method therefor | |
| KR20000069247A (en) | Surface treatment composition for metallic material and method for treatment | |
| CN101760736A (en) | Galvanized steel sheet surface treating agent, galvanized steel sheet and preparation methods thereof | |
| CN101481553A (en) | Normal temperature cured self-assembly composite nano oxide anti-corrosive paint | |
| CN1786091A (en) | magnesium alloy non-chromium dacro solution paint and its preparation method | |
| CN110157269B (en) | Steel structure anticorrosion construction process | |
| CN102181228A (en) | Metal surface silanization treatment agent and surface silanization treatment method using the same | |
| CN104984889A (en) | Zinc-aluminum coating enhanced with particles in micro-nano sizes and production method of zinc-aluminum coating | |
| CN109722661A (en) | Rear-earth-doped inorganic agent of a kind of basic silane for Treatment of Metal Surface and its preparation method and application | |
| CN115233203A (en) | Aluminum plate pre-color-coating chromium-free passivation solution for improving paint binding force and coating process thereof | |
| CN109575801B (en) | Preparation method of rare earth/silane-doped composite super-hydrophobic functional coating | |
| CN102070928B (en) | Color coating chromium-free pretreatment solution for galvanized plate | |
| CN115260899A (en) | Hydrophobic coating and preparation method and application thereof | |
| CN109487256A (en) | A kind of surface treating agent before the electrophoretic painting for galvanized sheet | |
| CN110560344B (en) | Aluminum alloy surface ATS composite membrane compatible with FEVE fluorocarbon powder coating and preparation method thereof | |
| CN103937300A (en) | Anticorrosion treatment method for cooling tower metal parts and coating used in anticorrosion treatment method | |
| CN111334146A (en) | Long-acting anticorrosion water-based cold-coating zinc coating and preparation method thereof | |
| CN108611631B (en) | Processing technology of anti-corrosion easy-to-process galvanized steel sheet | |
| CN114854281A (en) | Graphene activated water-based epoxy zinc-rich anticorrosive paint and preparation method thereof |
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 | ||
| WW01 | Invention patent application withdrawn after publication |
Application publication date: 20221025 |
|
| WW01 | Invention patent application withdrawn after publication |