Disclosure of Invention
Aiming at the defect of short cathodic protection action time of the existing cold-coating zinc coating, the invention aims to provide a polythiophene modified cold-coating zinc coating and a preparation method thereof, which can obviously improve the cathodic protection action of the cold-coating zinc coating.
The technical scheme of the invention is as follows:
the polythiophene modified cold-coating zinc coating comprises the following components in parts by weight:
the zinc powder is modified zinc powder subjected to polythiophene modification treatment.
The zinc powder of the polythiophene modified cold-coating zinc coating is modified by a polythiophene aqueous solution, and the content of polythiophene in the polythiophene aqueous solution is 0.3-20 wt%.
The polythiophene modified cold-coating zinc coating is characterized in that zinc powder is obtained by modifying poly (3, 4-ethylenedioxythiophene) aqueous solution, and the content of poly (3, 4-ethylenedioxythiophene) in the poly (3, 4-ethylenedioxythiophene) aqueous solution is 0.3-20 wt%.
The polythiophene modified cold-coating zinc coating is characterized in that zinc powder is modified by a sodium polystyrene sulfonate-doped polythiophene aqueous solution, the content of sodium polystyrene sulfonate-doped polythiophene in the sodium polystyrene sulfonate-doped polythiophene aqueous solution is 0.3-20 wt%, and the doping amount of the sodium polystyrene sulfonate is 100-2500 wt% of polythiophene.
The polythiophene modified cold-coating zinc paint is characterized in that zinc powder is modified by a sodium polystyrene sulfonate-doped poly (3, 4-ethylenedioxythiophene) aqueous solution, the content of the sodium polystyrene sulfonate-doped poly (3, 4-ethylenedioxythiophene) in the sodium polystyrene sulfonate-doped poly (3, 4-ethylenedioxythiophene) aqueous solution is 0.3-20 wt%, and the doping amount of the sodium polystyrene sulfonate is 100-2500 wt% of the poly (3, 4-ethylenedioxythiophene).
The preparation method of the polythiophene modified cold-coating zinc coating comprises the following steps:
(1) adding a solvent into a reaction kettle, adding a polythiophene aqueous solution with the mass of 0.5-20% of that of the solvent in a stirring state, adding zinc powder according to 10-70% of that of the solvent, heating to 20-50 ℃, and reacting for 0.5-3 h; centrifuging the reactant, taking out the powder, rinsing the powder for 2-5 times by using a solvent, drying the powder for 10-24 hours at the temperature of 40-70 ℃, and grinding the powder into powder to prepare modified zinc powder;
(2) adding acrylic resin, a solvent and an auxiliary agent into a reaction kettle in sequence, and dispersing for 15-50 min at the rotating speed of 300-1000 rpm; then adding modified zinc powder, dispersing at 300-1000 rpm for 30-100 min, filtering and discharging to obtain the polythiophene modified cold-coating zinc coating.
The design idea of the invention is as follows:
the zinc powder in the cold-coated zinc coating reacts with a corrosive medium (water, chloride ions and the like) to generate zinc oxide, hydroxide or chloride, so the surface modification of the zinc powder is needed to improve the self-corrosion speed of the zinc powder in the corrosive medium, but the treated zinc powder also has conductivity and does not influence the play of the cathode protection effect of the zinc powder. Therefore, the invention uses polythiophene to carry out coating treatment on the surface of the zinc powder, reduces the self-corrosion speed of the zinc powder and prolongs the cathodic protection time of the cold-coating zinc coating.
The invention has the following advantages and beneficial effects:
1. after the zinc powder is coated by polythiophene, the dispersibility of the zinc powder is improved, and the compatibility with resin is improved.
2. After the zinc powder is subjected to polythiophene coating treatment, the storage stability of the cold-coating zinc coating is obviously improved.
3. After the zinc powder is subjected to polythiophene coating treatment, the cathode protection effect of the coating is obviously improved.
4. The invention adopts the polythiophene to lead the steel surface to enter a passivation state, and improves the corrosion protection effect of the cold-coating zinc coating.
5. The method is suitable for large-scale production of the polythiophene modified cold-coating zinc coating, the polythiophene modified cold-coating zinc coating can be widely applied to the anti-corrosion engineering of a steel structure, and the corrosion protection problems of power transmission and transformation facilities, high-speed rail facilities, highway facilities and the like can be conveniently and quickly solved.
Detailed Description
In a specific embodiment, the polythiophene modified cold-coating zinc coating comprises the following components in parts by weight:
wherein, the zinc powder can be micron-sized zinc powder with the granularity of 1-50 μm. The zinc powder is modified by polythiophene aqueous solution, and the content of polythiophene in the polythiophene aqueous solution is 0.3-20% (preferably 0.5-15%). The polythiophene is preferably poly (3, 4-ethylenedioxythiophene), the poly (3, 4-ethylenedioxythiophene) is preferably poly (3, 4-ethylenedioxythiophene) doped with sodium polystyrene sulfonate, and the doping amount of the sodium polystyrene sulfonate is 100 to 2500 weight percent of the poly (3, 4-ethylenedioxythiophene). The solvent refers to a solvent commonly used in preparing the coating, such as: deionized water, xylene, toluene, trimethylbenzene or butyl acetate, etc. The auxiliary agent is a dispersing agent, a defoaming agent, a leveling agent and an anti-settling agent commonly used for the coating, and the dispersing agent is as follows: disperbyk-108, Disperbyk-111, Disperbyk-115, Disperbyk-140 from BYK, Germany. Defoamers such as: BYK-012, BYK-014, BYK-055, BYK-066N of BYK, Germany. Leveling agents such as: EFKA 3030, EFKA 3033, EFKA 3600N or EFKA 3772N of Ciba, Netherlands. The anti-settling agent can be selected from organically modified bentonite, such as: bentone SD-1, Bentone SD-2, Bentone 27, Bentone 34 or Bentone 52.
The preparation method of the polythiophene modified cold-coating zinc coating comprises the following steps:
(1) preparation of modified zinc powder
Adding a solvent into a reaction kettle, adding a polythiophene aqueous solution with the mass of 0.5-20% of that of the solvent in a stirring state, adding zinc powder according to 10-70% of that of the solvent, heating to 20-50 ℃, and reacting for 0.5-3 h; centrifuging the reactant, taking out the powder, rinsing the powder for 2-5 times by using a solvent, drying the powder for 10-24 hours at the temperature of 40-70 ℃, and grinding the powder into powder to prepare modified zinc powder;
(2) adding acrylic resin, a solvent and an auxiliary agent into a reaction kettle in sequence, and dispersing for 15-50 min at the rotating speed of 300-1000 rpm; then slowly adding the modified zinc powder, dispersing for 30-100 min at 300-1000 rpm, filtering and discharging to prepare the polythiophene modified cold-coating zinc coating.
The present invention will be described in further detail below with reference to comparative examples and examples. In the following examples, the content of the sodium polystyrene sulfonate-doped poly (3, 4-ethylenedioxythiophene) in the aqueous solution of the sodium polystyrene sulfonate-doped poly (3, 4-ethylenedioxythiophene) was 1.5 wt%, and the doping amount of the sodium polystyrene sulfonate was 160 wt% of the poly (3, 4-ethylenedioxythiophene).
Example 1
In the embodiment, deionized water is added into a reaction kettle, 1% of sodium polystyrene sulfonate doped poly (3, 4-ethylenedioxythiophene) water solution by mass of the deionized water is added in a stirring state, zinc powder is added according to 40% of the mass of the deionized water, and the mixture is heated to 30 ℃ to react for 1 hour; centrifuging the reactant, taking out the powder, rinsing the powder for 3 times by using deionized water, drying the powder for 15 hours at the temperature of 60 ℃, and then grinding the powder into powder to prepare modified zinc powder;
adding 166.7kg of acrylic resin, 200kg of toluene, 0.4kg of Disperbyk-140 dispersing agent, 0.5kg of BYK-055 defoaming agent, 0.4kg of EFKA 3600N leveling agent and 0.4kg of BENTONE 52 anti-settling agent into a reaction kettle in sequence, and dispersing for 20min at the rotating speed of 700 rpm; then 833.3kg of modified zinc powder is slowly added, dispersed for 70min at 1200rpm, and discharged after filtration, thus preparing the sodium polystyrene sulfonate doped poly (3, 4-ethylenedioxythiophene) modified cold galvanizing coating.
Example 2
In the embodiment, deionized water is added into a reaction kettle, 8% of polystyrene sodium sulfonate doped poly (3, 4-ethylenedioxythiophene) water solution by mass of the deionized water is added in a stirring state, zinc powder is added according to 40% of the mass of the deionized water, and the mixture is heated to 30 ℃ to react for 1 hour; centrifuging the reactant, taking out the powder, rinsing the powder for 3 times by using deionized water, drying the powder for 15 hours at the temperature of 60 ℃, and then grinding the powder into powder to prepare modified zinc powder;
adding 166.7kg of acrylic resin, 200kg of toluene, 0.4kg of Disperbyk-140 dispersing agent, 0.5kg of BYK-055 defoaming agent, 0.4kg of EFKA 3600N leveling agent and 0.4kg of BENTONE 52 anti-settling agent into a reaction kettle in sequence, and dispersing for 20min at the rotating speed of 700 rpm; then 833.3kg of modified zinc powder is slowly added, dispersed for 70min at 1200rpm, and discharged after filtration, thus preparing the sodium polystyrene sulfonate doped poly (3, 4-ethylenedioxythiophene) cold galvanizing coating.
Example 3
In the embodiment, deionized water is added into a reaction kettle, polystyrene sodium sulfonate doped poly (3, 4-ethylenedioxythiophene) water solution with the mass of 15% of that of the deionized water is added in a stirring state, zinc powder is added according to 40% of that of the deionized water, and the mixture is heated to 30 ℃ to react for 1 hour; centrifuging the reactant, taking out the powder, rinsing the powder for 3 times by using deionized water, drying the powder for 15 hours at the temperature of 60 ℃, and then grinding the powder into powder to prepare modified zinc powder;
adding 166.7kg of acrylic resin, 200kg of toluene, 0.4kg of Disperbyk-140 dispersing agent, 0.5kg of BYK-055 defoaming agent, 0.4kg of EFKA 3600N leveling agent and 0.4kg of BENTONE 52 anti-settling agent into a reaction kettle in sequence, and dispersing for 20min at the rotating speed of 700 rpm; then 833.3kg of modified zinc powder is slowly added, dispersed for 70min at 1200rpm, and discharged after filtration, thus preparing the sodium polystyrene sulfonate doped poly (3, 4-ethylenedioxythiophene) cold galvanizing coating.
Comparative example 1
In the comparative example, 166.7kg of acrylic resin, 200kg of toluene, 0.4kg of Disperbyk-140 dispersing agent, 0.5kg of BYK-055 defoaming agent, 0.4kg of EFKA 3600N leveling agent and 0.4kg of BENTONE 52 anti-settling agent are sequentially added into a reaction kettle and dispersed for 20min at the rotating speed of 700 rpm; then 833.3kg of zinc powder without modification treatment is slowly added, dispersed for 70min at 1200rpm, and discharged after filtration, thus preparing the cold galvanizing coating.
And (3) testing the performance of the cold galvanizing coating:
testing of corrosion potential: the test was performed using a Princeton 273A electrochemical test system. The electrolytic cell adopts a three-electrode system, the auxiliary electrode is a platinum electrode, the reference electrode is a Saturated Calomel Electrode (SCE), the coating/matrix sample is a working electrode, and the effective area of the working electrode is about 12.56cm2The corrosion medium is 3.5 wt% NaCl solution, and the corresponding soaking time when the corrosion potential is-0.86V/SCE is recorded, namely the time is equivalent to the cathodic protection action time of the coating.
TABLE 1 coating test results
|
Soaking time h corresponding to corrosion potential of-0.86V
|
Comparative example 1
|
2000
|
Example 1
|
2400
|
Example 2
|
2550
|
Example 3
|
2680 |
Table 1 shows the results of the coating tests. From the test results obtained, it can be seen that the cathodic protection times of the coatings prepared in examples 1, 2 and 3 are extended by 20%, 27.5% and 34%, respectively, with reference to comparative example 1, after the zinc powder has been modified with an aqueous solution of sodium polystyrene sulfonate-doped poly (3, 4-ethylenedioxythiophene). The method for modifying the polythiophene aqueous solution can enhance the cathode protection effect of the coating and improve the corrosion protection performance of the coating.