Aqueous polyaniline polymer, method for its preparation and anticorrosive coating

Abstract

The application provides a water-based polyaniline polymer, a preparation method thereof and anticorrosive paint, and relates to the technical field of corrosion protection. The water-based polyaniline polymer is obtained by in-situ polymerization of aniline monomers in the internal layer and the external surface of aluminum dihydrogen tripolyphosphate through an interfacial polymerization method, and surface modification of the polyaniline polymer is performed by using a water-based dopant. The water-based polyaniline polymer provided by the application fully utilizes the passivation and corrosion protection performance of aluminum dihydrogen tripolyphosphate and polyaniline, and greatly improves the corrosion protection effect through the synergistic effect between the two. Experimental results show that when the water-based polyaniline polymer provided by the application is applied to anticorrosive paint, the adhesion of the coating formed on the surface of a metal substrate is increased to 13 MPa, and neutral salt spray reaches 2000 h.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of corrosion protection technology, and particularly relates to a water-based polyaniline polymer, a preparation method thereof and a corrosion protection coating. BACKGROUND

[0002] Green and environmentally-friendly water-based corrosion protection coating refers to a kind of corrosion protection coating without harmful substances and harmful to the environment and human health, using water as solvent. Green and environmentally-friendly water-based corrosion protection coating without heavy metals such as lead and chromium has become the development trend in this field. The most representative one is zinc-based water-based corrosion protection coating system. However, as a valuable mineral resource in China, zinc ore has wide industrial value and application fields, and the demand for it in various fields is increasing. Therefore, developing new water-based corrosion protection coating independent of zinc powder has become a new development trend in the field of water-based corrosion protection coating.

[0003] The corrosion protection performance of corrosion protection coating mainly depends on the film-forming resin and corrosion protection material. Polyaniline has been widely recognized in the industry for its unique corrosion protection mechanism and excellent performance, and has become an important corrosion protection coating system in recent years and has been extensively studied. However, the corrosion protection performance of the current water-based corrosion protection coating system is still far behind that of solvent-based corrosion protection coating. Problems such as blistering, paint film peeling and serious corrosion of metal substrate occur after 120 hours of neutral salt spray test, the corrosion protection performance is poor, and it is difficult to meet the requirement of long-term corrosion protection performance. SUMMARY

[0004] Therefore, the present application discloses a water-based polyaniline polymer, a preparation method thereof and a corrosion protection coating. The tripolyphosphate ion in the water-based polyaniline polymer disclosed by the present application can form a chelate with metal ions and form a stable protective film on the metal surface, improving the long-term corrosion protection performance of the coating, and the adhesion is improved to 13 MPa, and the neutral salt spray test reaches 2000 h.

[0005] The present application provides a water-based polyaniline polymer with the structure of formula (I):

[0006] (I);

[0007] wherein n is an integer of 1-500, 0

[0008] R1 is selected from hydrogen, C1-C4 alkyl, C6-C10 aromatic group or C6-C10 heteroaromatic group; 10 20 20

[0009] R — is selected from an acid radical ion containing an ethoxy repeating unit.

[0010] ​​​In some embodiments, R1 is selected from hydrogen or C1-C 10 alkyl;

[0011] R — is selected from the following structures:

[0012] , , ;

[0013] m is an integer from 1 to 15.

[0014] The present application provides a method for preparing an aqueous polyaniline polymer, comprising:

[0015] a) polymerizing an aniline compound represented by formula (II), an initiator and aluminum dihydrogen tripolyphosphate to obtain a polyaniline compound;

[0016] b) modifying the polyaniline compound obtained in step a) after mixing with an aqueous dopant to obtain an aqueous polyaniline polymer represented by formula (I);

[0017] (II);

[0018] The aqueous dopant is selected from an acid containing ethoxy repeating units.

[0019] (I);

[0020] wherein n is an integer from 1 to 500, 0

[0021] R1 is selected from hydrogen, C1-C 10 alkyl, C6-C 20 aromatic group or C6-C 20 heteroaromatic group;

[0022] R — is selected from an acid radical ion containing ethoxy repeating units.

[0023] In some embodiments, the molar ratio of the aniline compound, the initiator and aluminum dihydrogen tripolyphosphate is (91-220):(67-400):(0.47-1.95).

[0024] The mass ratio of the aqueous dopant and the aniline compound is 1:0.3-3.

[0025] The present application also provides an aqueous anticorrosive coating, comprising component A and component B.

[0026] The component A comprises the following components by mass:

[0027] The technical scheme provides water-based polyaniline polymer 0.5-4 parts, water-based epoxy resin 20-120 parts, water 5-20 parts, water-based film forming auxiliary solvent 10-30 parts, titanium white powder 5-20 parts, talc powder 8-40 parts, precipitated barium sulfate 3-15 parts, water-based defoaming agent 0.3-3 parts, and water-based dispersing agent 0.4-3 parts.

[0028] The component B comprises the following mass parts of ingredients:

[0029] Water-based epoxy curing agent 65-90 parts; anti-flash rust agent 0.3-0.7 parts.

[0030] In some specific implementations, the mass ratio of the component A and the component B is 1-5:1.

[0031] In some specific implementations, the water-based epoxy resin is selected from at least one of HENKEL PZ3961-1, Shanghai Huayi STW606, Shanghai Huayi STW6521 and Shanghai Huayi STW6522.

[0032] In some specific implementations, the water-based defoaming agent is selected from at least one of BYK-052, BYK-088, BYK-1752, BYK-053, BYK-051, BYK-057, BYK-077, BYK-066N, BYK-392, BYK-333, BYK-141 and BYK-1790.

[0033] In some specific implementations, the water-based epoxy curing agent is selected from at least one of HENKEL AD3986, HENKEL AD3987, HENKEL AD38-1, Shanghai Huayi STW703C and Shanghai Huayi STW703D.

[0034] In some specific implementations, the water-based dispersing agent is selected from at least one of Disperbyk-103, Disperbyk-108, Disperbyk-115, Disperbyk-130, Disperbyk-111, Disperbyk-180, Disperbyk-160, Disperbyk-162, Disperbyk-164 and Disperbyk-182.

[0035] The application provides a water-based polyaniline polymer, a preparation method thereof and a corrosion-resistant coating. The water-based polyaniline polymer is prepared by in-situ polymerization of aniline monomers in the internal layer and the external surface of aluminum dihydrogen tripolyphosphate through an interfacial polymerization method. The larger specific surface area of polyaniline fibers enables polyaniline to have a larger contact area on a metal surface, and thus a larger passivation protective layer is formed on the surface of the metal substrate, and the corrosion resistance is improved. Experimental results show that when the water-based polyaniline polymer provided by the application is applied to the corrosion-resistant coating, the adhesion of the water-based polyaniline polymer to the surface of the metal substrate is increased to 13 MPa, and the neutral salt spray reaches 2000 h. BRIEF DESCRIPTION OF DRAWINGS

[0036] Figure 1 is a SEM image of aluminum dihydrogen tripolyphosphate;

[0037] Figure 2 is a SEM image of the water-based polyaniline polymer prepared in Example 1;

[0038] Figure 3 is a SEM image of the water-based polyaniline polymer prepared in Example 2;

[0039] Figure 4 is a SEM image of the water-based polyaniline polymer prepared in Comparative Example 1. DETAILED DESCRIPTION

[0040] It should be understood that the expression “one or more of’ alone includes each of the objects recited after the expression and various combinations of two or more of the recited objects, unless otherwise understood from the context and usage. The expression “and / or” in combination with three or more recited objects should be understood to have the same meaning, unless otherwise understood from the context.

[0041] The use of the terms “including,” “has,” “having” or “contains” and variations thereof, including the conjugations of the same, is intended to be open, and is used to mean that other objects, steps, or actions not specifically recited are optional and can be added to the subject of the expression, unless otherwise specifically stated or understood from the context.

[0042] It should be understood that the order of steps or order for performing certain actions is immaterial so long as the application remains operable. Moreover, two or more steps or actions can be conducted simultaneously.

[0043] The use of any and all examples, or exemplary language herein, for example, only the intention to better illustrate the application, and unless otherwise claimed, does not limit the scope of the application. Any language in the specification should not be interpreted as indicating any unclaimed element is essential to the practice of the application.

[0044] Also, the numerical ranges recited herein are approximate, and include all values subsumed therein. Unless otherwise indicated, all ranges, numbers, values and percentages recited herein are modified in all instances by the term "about." As used herein, "about" refers to a value that is reasonably close to the stated value, plus or minus 10%, 5%, 1% or 0.5% of the stated value.

[0045] The water-based polyaniline polymer provided by the present application has the structure of formula (I):

[0046] (I);

[0047] wherein n is an integer from 1 to 500, preferably an integer from 10 to 50, and more preferably an integer from 20 to 500; y is an integer from 0 to 4, preferably an integer from 0 to 3, and more preferably an integer from 0 to 2; 0 < x < 1;

[0048] R1 is selected from hydrogen, C1-C4 alkyl, C6-C10 aryl or C6-C10 heteroaryl; 10 20 20

[0049] R — is selected from an acid radical ion containing ethoxy repeating units.

[0050] The present application prepares a water-based polyaniline polymer by an interfacial polymerization method, in which aniline monomers are in-situ polymerized inside the sheet layer and on the outer surface of aluminum dihydrogen tripolyphosphate. The aluminum dihydrogen tripolyphosphate component contains a tripolyphosphate radical ion (P3O 10 5- ) with very strong chelating power, which can form a chelate with metal ions and form a stable protective film on the surface of the metal, and has good corrosion resistance to the metal. Figure 1 The scanning electron microscope image of aluminum dihydrogen tripolyphosphate is shown, from which the sheet layer morphology can be clearly seen. The water-based polyaniline polymer provided by the present application fully utilizes the passivation and corrosion resistance of aluminum dihydrogen tripolyphosphate and polyaniline, and greatly improves the corrosion resistance through the synergistic effect between the two.

[0051] In some specific implementation manners, R1 is selected from hydrogen or C1-C4 alkyl, and is preferably hydrogen. 10

[0052] The present application uses phosphoric acid containing ethoxy repeating units or sulfonic acid containing ethoxy repeating units as a water-based dopant, disperses polyaniline in water, and obtains a water-based polyaniline polymer. In some specific implementation manners, R — is selected from the following structures:​​​​

[0053] 、 、 ;

[0054] m is an integer from 1 to 15.

[0055] The present application provides a preparation method of the aqueous polyaniline polymer, comprising:

[0056] a) polymerizing an aniline compound represented by formula (II), an initiator and aluminum dihydrogen tripolyphosphate to obtain a polyaniline compound;

[0057] b) modifying the polyaniline compound obtained in step a) after mixing with an aqueous dopant to obtain an aqueous polyaniline polymer represented by formula (I);

[0058] (II);

[0059] The aqueous dopant is selected from an acid containing ethoxy repeating units.

[0060] (I);

[0061] wherein n is an integer from 1 to 500, 0 < x < 1, and y is an integer from 0 to 4.

[0062] R1 is selected from hydrogen, C1-C4 alkyl, C6-C10 aromatic group or C6-C10 heteroaromatic group; 10 20 20

[0063] R — is selected from an acid radical ion containing ethoxy repeating units.

[0064] The present application first dissolves aluminum dihydrogen tripolyphosphate, an initiator and an aniline compound respectively, and then polymerizes to obtain a polyaniline compound. In some specific implementations, the solvent of the aluminum dihydrogen tripolyphosphate is selected from at least one of a water-soluble solvent and water. In some specific implementations, the solvent of the initiator is selected from at least one of an inorganic acid, a water-soluble solvent and water. In some specific implementations, the solvent of the aniline compound is a non-water-soluble solvent.

[0065] ​​​In some specific embodiments, the water-soluble solvent is selected from at least one of methanol, ethanol, isopropanol, ethylene glycol ethyl ether, ethylene glycol butyl ether, ethylene glycol and glycerol; preferably at least one of methanol, ethanol and isopropanol; and more preferably at least one of methanol and isopropanol. In some specific embodiments, the inorganic acid is selected from at least one of hydrochloric acid, sulfuric acid, phosphoric acid, nitric acid, acetic acid and carbonic acid; preferably at least one of hydrochloric acid, sulfuric acid and phosphoric acid; and more preferably hydrochloric acid. In some specific embodiments, the non-water-soluble solvent is selected from at least one of carbon tetrachloride, chloroform, benzene, toluene and xylene; preferably at least one of carbon tetrachloride and chloroform; and more preferably carbon tetrachloride.

[0066] In some specific embodiments, the molar ratio of the aniline compound, the initiator and the aluminum dihydrogen tripolyphosphate is (91-220):(67-400):(0.47-1.95).

[0067] After obtaining the polyaniline compound, the present application preferably immerses it in an alkaline solution to change the activation energy of its surface and increase the effect of the modification reaction. In some specific embodiments, the alkaline solution is selected from one or more of aqueous ammonia, triethylamine, sodium hydroxide solution, sodium bicarbonate solution, sodium carbonate solution, potassium bicarbonate solution and potassium hydroxide solution; preferably one or more of aqueous ammonia, triethylamine, sodium hydroxide solution and sodium bicarbonate solution; and more preferably aqueous ammonia. In some specific embodiments, the polyaniline compound is immersed in the alkaline solution for 18-36 hours at room temperature. After the immersion, the polyaniline compound is washed with deionized water and dried to obtain a polyaniline compound powder.

[0068] After mixing the polyaniline compound powder, the aqueous dopant and water, a modification reaction occurs to obtain the aqueous polyaniline polymer.

[0069] In some specific embodiments, the modification reaction is carried out in an inert atmosphere, preferably a nitrogen atmosphere or an argon atmosphere, and more preferably a nitrogen atmosphere. In some specific embodiments, the modification reaction is carried out for 4-6 hours at a temperature of 60-80°C. In some specific embodiments, the mass ratio of the aqueous dopant to the aniline compound is 1:0.3-3.

[0070] The phosphoric acid containing ethoxy repeating units and the sulfonic acid containing ethoxy repeating units are preferably used in the modification reaction of the aqueous dopant, and the source thereof is not particularly limited, and can be purchased or synthesized by oneself. For example, the phosphoric acid containing ethoxy repeating units and the sulfonic acid containing ethoxy repeating units can be prepared according to the method of Geng et al. (Polymer, 1999, 40, 5723-5727): phosphorus oxide or sulfur oxide, polyethylene glycol monomethyl ether are uniformly mixed in benzene to react, the reaction temperature is 50-90℃, and the reaction time is 2-5h, so that the phosphoric acid containing ethoxy repeating units or the sulfonic acid containing ethoxy repeating units are obtained.

[0071] The application further provides an aqueous anticorrosive coating, which comprises component A and component B.

[0072] The component A comprises the following components by mass fraction:

[0073] The aqueous polyphenylamine polymer is 0.5-4 parts, preferably 0.5-3.7 parts, and more preferably 0.5-3.5 parts; the aqueous epoxy resin is 20-120 parts, preferably 25-120 parts, and more preferably 28-120 parts; the water is 5-20 parts, preferably 8-20 parts, and more preferably 10-20 parts; the aqueous film-forming auxiliary solvent is 10-30 parts, preferably 12-30 parts, and more preferably 15-30 parts; the titanium white is 5-20 parts, preferably 5-17 parts, and more preferably 5-15 parts; the talc is 8-40 parts, preferably 8-37 parts, and more preferably 8-35 parts; the precipitated barium sulfate is 3-15 parts, preferably 3-13 parts, and more preferably 3-12 parts; the aqueous defoaming agent is 0.3-3 parts, preferably 0.3-2.5 parts, and more preferably 0.3-2 parts; and the aqueous dispersing agent is 0.4-3 parts, preferably 0.4-2.5 parts, and more preferably 0.4-2 parts.

[0074] The component B comprises the following components by mass fraction:

[0075] The aqueous epoxy curing agent is 65-90 parts, preferably 65-85 parts, and more preferably 65-80 parts; the anti-flash rust agent is 0.3-0.7 parts, preferably 0.3-0.6 parts, and more preferably 0.3-0.5 parts.

[0076] The application adds the above water-based polyaniline polymer in the anticorrosive paint, fully utilizes the passivation and anticorrosion performance of aluminum dihydrogen tripolyphosphate and polyaniline, greatly improves the anticorrosion effect through the synergistic effect between the two. Moreover, the aluminum dihydrogen tripolyphosphate is weakly acidic, and its dissociation constant pKa is 1.5-1.6. Through the salt reaction of aniline monomer with the aluminum dihydrogen tripolyphosphate, the two substances are first combined together at the molecular level, and then in-situ polymerization of aniline on the aluminum dihydrogen tripolyphosphate is carried out to form the aluminum dihydrogen tripolyphosphate inorganic hybrid polyaniline composite. Moreover, the relative density of the aluminum dihydrogen tripolyphosphate is relatively large, which is 2.31 g / cm 3 In the water-based paint, it is easy to settle, and the compatibility with the water-based resin is poor. The composite material of the application organically combines the aluminum dihydrogen tripolyphosphate and polyaniline, can be well dispersed in the water-based resin, and the density of polyaniline is small, thereby avoiding the settlement problem of the aluminum dihydrogen tripolyphosphate.

[0077] In some specific implementations, the mass ratio of the component A and the component B is 1-5:1.

[0078] The water-based epoxy resin has excellent physical and mechanical properties, aging resistance, freeze-thaw resistance, corrosion resistance and other characteristics; at the same time, it has excellent waterproof performance and good chemical corrosion resistance, and can effectively prevent the corrosion of acid, alkali, salt and other chemicals. In some specific implementations, the water-based epoxy resin is selected from one or more of HENSMAY PZ3961-1, Shanghai Huayi STW606, Shanghai Huayi STW6521, and Shanghai Huayi STW6522. The application does not have special requirements for the proportion of each substance.

[0079] The water-based defoaming agent can be quickly dispersed in the paint system, effectively reduce the liquid tension, destroy the stability of the foam, realize rapid defoaming and prevent the regeneration of the foam, significantly improve the construction performance of the paint, make the coating surface smooth and bubble-free, and improve the corrosion resistance. In some specific implementations, the water-based defoaming agent is selected from one or more of BYK-052, BYK-088, BYK-1752, BYK-053, BYK-051, BYK-057, BYK-077, BYK-066N, BYK-392, BYK-333, BYK-141, and BYK-1790. The application does not have special requirements for the proportion of each substance.

[0080] The water-based epoxy curing agent can cause the coating surface to rapidly harden, thereby achieving accelerated drying; meanwhile, it can significantly improve the hardness of the coating, making the coating more durable and wear-resistant. After the coating is applied, the curing agent continues to function, improving the hardness and toughness of the coating surface, thereby enhancing the protective ability of the coating. In some specific implementations, the water-based epoxy curing agent is selected from one or more of Hensyl AD3986, Hensyl AD3987, Hensyl AD38-1, Shanghai Huayi STW703C, and Shanghai Huayi STW703D, and the present application does not have special requirements for the proportions of each substance.

[0081] The water-based dispersant can effectively prevent the aggregation of particles of each component of the anticorrosive coating, thereby ensuring that the coating forms a uniform and dense protective film on the metal surface, which not only improves the anticorrosive performance of the coating but also prolongs the service life of the metal material. In some specific implementations, the water-based dispersant is selected from one or more of Disperbyk-103, Disperbyk-108, Disperbyk-115, Disperbyk-130, Disperbyk-111, Disperbyk-180, Disperbyk-160, Disperbyk-162, Disperbyk-164, and Disperbyk-182, and the present application does not have special requirements for the proportions of each substance.

[0082] The anti-flash rust agent can prevent the occurrence of flash rusting on the metal surface during or after painting due to environmental factors such as moisture and oxygen. It can instantaneously shield metal ions or reduce the reactivity of metal ions, cut off or reduce the supply of oxygen, thereby effectively preventing the occurrence of flash rusting. In some specific implementations, the anti-flash rust agent is selected from one or more of ASCOTEC H10, ASCOTEC H14, ASCOTEC H18, and Hymidiszen FA179, and the present application does not have special requirements for the proportions of each substance.

[0083] The water-based film-forming aid can lower the minimum film-forming temperature of the water-based epoxy resin, allowing it to form a continuous and ideal coating film at a lower temperature; meanwhile, by adjusting the drying speed, it can improve the hardness and anti-sticking properties of the paint film. In some specific implementations, the water-based film-forming aid is selected from one or more of ethylene glycol butyl ether, diethylene glycol butyl ether, propylene glycol phenyl ether, dipropylene glycol methyl ether, propylene glycol butyl ether, dipropylene glycol butyl ether, dipropylene glycol propyl ether, and propylene glycol, and the present application does not have special requirements for the proportions of each substance.

[0084] For the above-mentioned water-based anticorrosive coating, the present application also provides a preparation method, which specifically includes:

[0085] 1) After the waterborne polyaniline polymer, waterborne epoxy resin, water, titanium dioxide, talc, precipitated barium sulfate and waterborne dispersant are uniformly dispersed, waterborne film-forming aid and waterborne defoaming agent are added and stirring is continued for 15-25 min, a 60-100 mesh filter screen is used for filtration, and component A is obtained;

[0086] 2) The waterborne epoxy curing agent and water are uniformly dispersed, and then waterborne film-forming aid and anti-flash rust agent are added and stirring is continued for 10-15 min, and component B is obtained.

[0087] The application provides a waterborne polyaniline polymer, a preparation method thereof and a corrosion-resistant coating. The application prepares a waterborne polyaniline polymer by in-situ polymerization of aniline monomers in the internal layer and external surface of aluminum dihydrogen tripolyphosphate through an interfacial polymerization method. The larger specific surface area of polyaniline fibers enables polyaniline to have a larger contact area on a metal surface, and a larger passivation protective layer is formed on the surface of a metal substrate, thereby improving the corrosion resistance.

[0088] The application will be further described below in combination with examples. The protection scope of the application is not limited by the following examples.

[0089] Example 1

[0090] (1) 0.35 g of aluminum dihydrogen tripolyphosphate, 80 g of isopropyl alcohol and 100 g of deionized water are placed into a beaker, and ultrasonic treatment is performed for 2 hours to form a water dispersion A;

[0091] (2) 38.5 g of ammonium persulfate is added into 300 ml of 1 mol / L hydrochloric acid solution, and 120 g of methanol, 200 g of deionized water are added into the solution to prepare an aqueous solution B; the water dispersion A is added into the aqueous solution B, and stirring is performed for 10 min to obtain a water dispersion C;

[0092] (3) 14.9 g of aniline and 600 ml of carbon tetrachloride are added into a beaker, and electromagnetic stirring is performed for 5 min to form an organic solution; the water dispersion C is slowly poured into the organic solution along the wall of the beaker to form a stable interface between the two phases, the mouth of the beaker is sealed with a polyethylene film, and the beaker is placed in an environment at 8℃ and left to stand for 24 h;

[0093] (4) The product obtained in step (3) is filtered through a G3 sand core funnel, and 150 ml of deionized water is used for washing, and the operation is repeated for 5 times; after washing and suction filtration, a solid powder is obtained;

[0094] (5) The solid powder obtained in step (4) is added into 150 ml of ammonia water, stirring is performed at room temperature for 20 min, and soaking is performed for 24 h; the solid powder is filtered through a G3 sand core funnel, and 300 ml of deionized water is used for washing, and the operation is repeated for 8 times; after washing and suction filtration, a polyaniline compound powder is obtained;

[0095] (6) Put the polyaniline compound powder obtained in step (5) into a three-necked flask, add 10.1 g of phosphate ester aqueous dopant (structure as follows) and 320 ml of deionized water, and control the temperature at 60°C under nitrogen protection for 6 hours of stirring to obtain an aqueous polyaniline solution;

[0096] (7) Centrifuge the aqueous polyaniline solution with a centrifuge at 5000 rpm for 30 min, separate the aqueous solution, collect the solid, and put the solid into a vacuum oven, control the temperature at 40°C, and dry for 48 h to obtain an aqueous polyaniline polymer. Figure 2 The SEM electron microscope image of the aqueous polyaniline polymer prepared in the embodiment is shown.

[0097]

[0098] The aqueous dopant structure of the embodiment

[0099] Example 2

[0100] (1) Put 0.62 g of aluminum dihydrogen tripolyphosphate, 180 g of ethanol, and 200 g of deionized water into a beaker, and ultrasonic for 2 hours to form a water dispersion A;

[0101] (2) Add 39.5 g of sodium persulfate to 350 ml of 1 mol / L phosphoric acid solution, and add 160 g of ethanol and 240 g of deionized water to the solution to prepare an aqueous solution B; add the water dispersion A to the aqueous solution B, and stir for 10 min to obtain a water dispersion C;

[0102] (3) Add 18.5 g of aniline and 550 ml of chloroform to a beaker, and electromagnetically stir for 15 min to form an organic solution; slowly pour the water dispersion C into the organic solution along the wall to form a stable interface between the two phases, seal the cup opening of the beaker with a polyethylene film, and place it in a 15°C environment for 24 h of standing;

[0103] (4) The product obtained in step (3) is filtered through a G3 sand core funnel, and washed with 300 ml of deionized water, which is repeated 5 times. After washing and suction filtration, a solid powder is obtained;

[0104] (5) Add the solid powder obtained in step (4) to 380 g of 40% sodium carbonate aqueous solution, stir at room temperature for 30 min, soak for 24 h, filter through a G3 sand core funnel, and wash with 500 ml of deionized water, which is repeated 8 times. After washing and suction filtration, a polyaniline compound powder is obtained;

[0105] (6) Put the polyaniline compound powder obtained in step (5) into a three-necked flask, add 15.8 g of phosphate ester aqueous dopant (structure as follows) and 320 ml of deionized water, control the temperature at 80°C under nitrogen protection, and stir for 4 hours to obtain an aqueous polyaniline solution;

[0106] (7) Centrifuge the aqueous polyaniline solution with a centrifuge at 10000 rpm for 20 min, separate the aqueous solution, collect the solid powder, and place the solid powder into a vacuum oven, control the temperature at 50°C, and dry for 24 h to obtain an aqueous polyaniline polymer. Figure 3 The SEM electron microscope image of the aqueous polyaniline polymer prepared in the embodiment is shown.

[0107]

[0108] The aqueous dopant structure of the embodiment

[0109] Embodiment 3

[0110] (1) Put 0.3 g of aluminum dihydrogen tripolyphosphate, 60 g of isopropyl alcohol, and 140 g of deionized water into a beaker, and ultrasonic for 2 hours to form a water dispersion A;

[0111] (2) Add 47.5 g of potassium dichromate to 420 ml of 1 mol·L-1nitric acid solution, and add 180 g of ethylene glycol ether and 160 g of deionized water to the solution to prepare an aqueous solution B; add the water dispersion A to the aqueous solution B, and stir for 8 min to obtain a water dispersion C;

[0112] (3) Add 13.5 g of aniline and 500 ml of benzene to a beaker, and electromagnetically stir for 5 min to form an organic solution; slowly pour the water dispersion C into the organic solution along the wall to form a stable interface between the two phases, seal the cup opening of the beaker with a polyethylene film, and place it in a 10°C environment for 24 h of static placement;

[0113] (4) The product obtained in step (3) is filtered through a G3 sand core funnel, and washed with 220 ml of deionized water, and the operation is repeated for 8 times. After washing and suction filtration, a solid powder is obtained;

[0114] (5) Add the solid powder obtained in step (4) to 280 ml of 30% sodium hydroxide solution, stir at room temperature for 35 min, soak for 18 hours, filter through a G3 sand core funnel, and wash with 350 ml of deionized water, and the operation is repeated for 10 times. After washing and suction filtration, a polyaniline compound powder is obtained;

[0115] (6) Put the polyaniline compound powder obtained in step (5) into a three-necked flask, add 20.6 g of phosphate aqueous dopant (structure as follows) and 260 ml of deionized water, control the temperature at 70°C under nitrogen protection, and stir for 5 hours to obtain an aqueous polyaniline solution;

[0116] (7) Centrifuge the aqueous polyaniline solution with a centrifuge at 8000 rpm for 30 min, separate the aqueous solution, collect the solid powder, put the solid powder into a vacuum oven, control the temperature at 40°C, and dry for 48 h to obtain an aqueous polyaniline polymer.

[0117]

[0118] Structure of the aqueous dopant in this example

[0119] Example 4

[0120] (1) Put 0.55 g of aluminum dihydrogen tripolyphosphate, 85 g of ethylene glycol butyl ether, and 115 g of deionized water into a beaker, and ultrasonically treat for 2 hours to form a water dispersion A;

[0121] (2) Add 35.3 g of potassium iodate to 310 ml of 1 mol / L carbonic acid, and add 150 g of ethylene glycol butyl ether and 160 g of deionized water to the solution to prepare an aqueous solution B; add the water dispersion A to the aqueous solution B, and stir for 10 min to obtain a water dispersion C;

[0122] (3) Add 20.8 g of aniline and 450 ml of dimethylbenzene to a beaker, and electromagnetically stir for 8 min to form an organic solution; slowly pour the water dispersion C into the organic solution along the wall to form a stable interface between the two phases, seal the mouth of the beaker with a polyethylene film, and place it in a 12°C environment for 24 h of static placement;

[0123] (4) Filter the product obtained in step (3) through a G3 sand core funnel, and wash it with 170 ml of deionized water, which is repeated 7 times; after washing and suction filtration, a solid powder is obtained;

[0124] (5) Add the solid powder obtained in step (4) to 275 ml of a 45% sodium bicarbonate solution, stir at room temperature for 20 min, soak for 36 h, filter through a G3 sand core funnel, and wash it with 420 ml of deionized water, which is repeated 8 times; after washing and suction filtration, a polyaniline compound powder is obtained;

[0125] (6) Put the polyaniline compound powder obtained in step (5) into a three-necked flask, add 22.5 g of phosphate aqueous dopant (structure as follows) and 250 ml of deionized water, control the temperature at 65°C under nitrogen protection, and stir for 5.5 hours to obtain an aqueous polyaniline solution;

[0126] (7) The aqueous polyaniline solution was centrifuged by a centrifuge at 3000 rpm for 30 min, and the aqueous solution was separated, and the solid powder was collected. The solid powder was placed into a vacuum oven, and the temperature was controlled at 45°C, and dried for 48 h to obtain the aqueous polyaniline polymer.

[0127]

[0128] The aqueous dopant structure of the present embodiment

[0129] Embodiment 5

[0130] (1) 0.15 g of aluminum dihydrogen tripolyphosphate, 50 g of ethylene glycol and 80 g of deionized water were weighed into a beaker, and ultrasonic treatment was performed for 2 h to form an aqueous dispersion A;

[0131] (2) 64.7 g of iron sulfate was added to 200 ml of 1 mol / L sulfuric acid solution, and 180 g of ethylene glycol and 140 g of deionized water were added to the solution to prepare an aqueous solution B; the aqueous dispersion A was added to the aqueous solution B, and stirred for 15 min to obtain an aqueous dispersion C;

[0132] (3) 11.8 g of aniline and 400 ml of dimethylbenzene were added to a beaker, and electromagnetic stirring was performed for 5 min to form an organic solution; the aqueous dispersion C was slowly poured into the organic solution along the wall to form a stable interface between the two phases, the mouth of the beaker was sealed with a polyethylene film, and was placed in an environment of 10°C and left to stand for 24 h;

[0133] (4) The product obtained in step (3) was filtered through a G3 sand core funnel, and washed with 200 ml of deionized water, and the operation was repeated 6 times. After washing and suction filtration, a solid powder was obtained;

[0134] (5) The solid powder obtained in step (4) was added to 310 ml of triethylamine, and stirred at room temperature for 16 min, and soaked for 36 h, and filtered through a G3 sand core funnel, and washed with 200 ml of deionized water, and the operation was repeated 10 times. After washing and suction filtration, a polyaniline compound powder was obtained;

[0135] (6) The polyaniline compound powder obtained in step (5) was placed into a three-necked flask, 18.6 g of sulfonate aqueous dopant (structure as follows) and 160 ml of deionized water were added, and stirring was performed at 70°C under nitrogen protection for 5 h to obtain an aqueous polyaniline solution;

[0136] (7) The aqueous polyaniline solution was centrifuged by a centrifuge at 3000 rpm for 30 min, and the aqueous solution was separated, and the solid powder was collected. The solid powder was placed into a vacuum oven, and the temperature was controlled at 45°C, and dried for 48 h to obtain the aqueous polyaniline polymer.

[0137]

[0138] Water-based dopant structure of the present embodiment

[0139] Example 6

[0140] (1) Put 0.6 g of aluminum dihydrogen tripolyphosphate, 200 g of ethylene glycol butyl ether and 150 g of deionized water into a beaker, and ultrasonically treat for 2 hours to form a water dispersion A;

[0141] (2) Put 26.7 g of ferric chloride into 220 ml of 1 mol / L hydrochloric acid solution, and add 160 g of ethylene glycol butyl ether and 100 g of deionized water to the solution to prepare an aqueous solution B; add the water dispersion A to the aqueous solution B, and stir for 12 min to obtain a water dispersion C;

[0142] (3) Put 8.5 g of aniline and 300 ml of chloroform into a beaker, and electromagnetically stir for 9 min to form an organic solution; slowly pour the water dispersion C into the organic solution along the wall of the beaker to form a stable interface between the two phases, seal the mouth of the beaker with a polyethylene film, and place it in an environment of 6°C, and stand for 24 h;

[0143] (4) Filter the product obtained in step (3) through a G3 sand core funnel, and wash with 170 ml of deionized water, and repeat this operation 8 times, to obtain a solid powder after washing and suction filtration;

[0144] (5) Put the solid powder obtained in step (4) into 360 ml of a 35% potassium bicarbonate aqueous solution, and stir at room temperature for 15 min, and soak for 36 h, filter through a G3 sand core funnel, and wash with 280 ml of deionized water, and repeat this operation 3 times, to obtain a polyaniline compound powder after washing and suction filtration;

[0145] (6) Put the polyaniline compound powder obtained in step (5) into a three-necked flask, add 24.9 g of a phosphate water-based dopant (structure as follows) and 150 ml of deionized water, and control the temperature at 75°C under nitrogen protection, and stir for 5.5 h to obtain a water-based polyaniline solution;

[0146] (7) Centrifuge the water-based polyaniline solution with a centrifuge at 5000 rpm for 30 min, separate the aqueous solution, and collect the solid powder, and put the solid powder into a vacuum oven, and control the temperature at 50°C, and dry for 24 h to obtain a water-based polyaniline polymer.

[0147]

[0148] Water-based dopant structure of the present embodiment

[0149] Comparative Example 1

[0150] The comparative example removes the aluminum dihydrogen tripolyphosphate component in step (1), and the remaining steps are the same as example 1, to obtain a polyaniline nanofiber material. Figure 4 The SEM image of the waterborne polyaniline polymer prepared in the comparative example is shown.

[0151] Example 7

[0152] a) 0.5 g of waterborne polyaniline polymer (prepared in example 1), 28 g of PZ3961-1, 10 g of deionized water, 5 g of titanium dioxide, 8 g of talc, 3 g of precipitated barium sulfate, and 0.4 g of Disperbyk-108 were added to a high-speed disperser and stirred at 1400 rpm for 30 min, then introduced into a sand mill for sanding, and sanding for 2 hours; after sanding, the material was introduced into a high-speed disperser, 15 g of ethylene glycol butyl ether and 0.3 g of BYK-052 were added, and stirred at 700 rpm for 20 min, then filtered with a 80 mesh screen to obtain component A;

[0153] b) In a high-speed dispersion container, 65 g of AD3986 and 10 g of deionized water were added, 15 g of ethylene glycol butyl ether and 0.3 g of ASCOTEC H10 were added in sequence at 550 rpm, and stirring was continued for 15 min to obtain component B; components A and B were mixed in a ratio of 3:2 to obtain a waterborne polyaniline anticorrosive coating PT01.

[0154] Example 8

[0155] a) 3.5 g of waterborne polyaniline polymer (prepared in example 2), 120 g of STW606, 20 g of deionized water, 15 g of titanium dioxide, 35 g of talc, 12 g of precipitated barium sulfate, and 2 g of Disperbyk-130 were added to a high-speed disperser and stirred at 1400 rpm for 30 min, then introduced into a sand mill for sanding, and sanding for 2 hours; after sanding, the material was introduced into a high-speed disperser, 30 g of propylene glycol phenyl ether and 2 g of BYK-1752 were added, and stirred at 700 rpm for 20 min, then filtered with a 80 mesh screen to obtain component A;

[0156] b) In a high-speed dispersion container, 80 g of AD3987 and 20 g of deionized water were added, 30 g of propylene glycol phenyl ether and 0.5 g of ASCOTEC H14 were added in sequence at 550 rpm, and stirring was continued for 15 min to obtain component B; components A and B were mixed in a ratio of 3:2 to obtain a waterborne polyaniline anticorrosive coating PT02.

[0157] Example 9

[0158] a) 0.8 g of aqueous polyaniline polymer (prepared in Example 3), 45 g of STW6522, 13 g of deionized water, 8 g of titanium dioxide, 17 g of talcum powder, 6 g of precipitated barium sulfate and 0.7 g of Disperbyk-180 were added into a high-speed disperser and stirred at 1400 rpm for 30 min, and then introduced into a sand mill tank for sand milling for 2 hours; after sand milling, the material was introduced into a high-speed disperser, 18 g of diethylene glycol butyl ether, 0.9 g of BYK-051 were added, and stirred at 700 rpm for 20 min, and filtered with a 80-mesh screen to obtain component A;

[0159] b) 70 g of STW703D and 13 g of deionized water were added into a high-speed dispersion container, 18 g of diethylene glycol butyl ether and 0.4 g of FA179 were added in sequence at 550 rpm, and stirring was continued for 15 min to obtain component B; components A and B were mixed in a ratio of 3:2 to obtain the aqueous polyaniline anticorrosive coating PT03.

[0160] Example 10

[0161] a) 1.5 g of aqueous polyaniline polymer (prepared in Example 4), 68 g of STW606, 15 g of deionized water, 10 g of titanium dioxide, 22 g of talcum powder, 4 g of precipitated barium sulfate and 1.3 g of Disperbyk-130 were added into a high-speed disperser and stirred at 1400 rpm for 30 min, and then introduced into a sand mill tank for sand milling for 2 hours; after sand milling, the material was introduced into a high-speed disperser, 22 g of propylene glycol phenyl ether, 1.4 g of BYK-1752 were added, and stirred at 700 rpm for 20 min, and filtered with a 80-mesh screen to obtain component A;

[0162] b) 75 g of AD3987 and 15 g of deionized water were added into a high-speed dispersion container, 22 g of propylene glycol phenyl ether and 0.35 g of ASCOTEC H14 were added in sequence at 550 rpm, and stirring was continued for 15 min to obtain component B; components A and B were mixed in a ratio of 3:2 to obtain the aqueous polyaniline anticorrosive coating PT04.

[0163] Example 11

[0164] a) 3.0 g of aqueous polyaniline polymer (prepared in Example 5), 85 g of PZ3961-1, 18 g of deionized water, 12 g of titanium dioxide, 15 g of talc, 10 g of precipitated barium sulfate and 1.5 g of Disperbyk-180 were added to a high-speed disperser and stirred at 1400 rpm for 30 min. Then the mixture was transferred to a sand mill for sand milling for 2 hours. After sand milling, the material was transferred to a high-speed disperser and 26 g of ethylene glycol butyl ether and 1.6 g of BYK-051 were added. The mixture was stirred at 700 rpm for 20 min and filtered through an 80-mesh filter to obtain component A.

[0165] b) In a high-speed dispersion container, add 78 g AD3986 and 18 g deionized water, and add 26 g ethylene glycol butyl ether and 0.45 g ASCOTEC H10 sequentially at 550 rpm. Continue stirring for 15 min to obtain component B. Mix component A and component B in a 3:2 ratio to obtain waterborne polyaniline anti-corrosion coating PT05.

[0166] Example 12

[0167] a) 2.6 g of aqueous polyaniline polymer (prepared in Example 6), 105 g of STW606, 16 g of deionized water, 7 g of titanium dioxide, 30 g of talc, 9 g of precipitated barium sulfate, and 1.8 g of Disperbyk-108 were added to a high-speed disperser and stirred at 1400 rpm for 30 min. Then, the mixture was transferred to a sand mill for sand milling for 2 hours. After sand milling, the material was transferred to a high-speed disperser, and 20 g of propylene glycol phenyl ether and 1.1 g of BYK-052 were added. The mixture was stirred at 700 rpm for 20 min and filtered through an 80-mesh filter to obtain component A.

[0168] b) In a high-speed dispersion container, add 72 g STW703D and 16 g deionized water, and add 20 g propylene glycol phenyl ether and 0.5 g FA179 sequentially at 550 rpm. Continue stirring for 15 min to obtain component B. Mix component A and component B in a 3:2 ratio to obtain waterborne polyaniline anti-corrosion coating PT06.

[0169] Comparative Example 2

[0170] Compared with Example 7, the difference is that 0.5g of the waterborne polyaniline polymer prepared in Comparative Example 1 was used instead of 0.5g of the waterborne polyaniline polymer prepared in Example 1, while the rest were the same, to obtain the waterborne polyaniline anti-corrosion coating DT01.

[0171] Comparative Example 3

[0172] Compared with Example 8, the difference is that 0.5 g of aluminum dihydrogen tripolyphosphate is used instead of 0.5 g of the waterborne polyaniline polymer prepared in Example 1, and the others are the same, to obtain a waterborne polyaniline anticorrosive coating DT02.

[0173] The raw material formulations of the waterborne polyaniline anticorrosive coatings PT01~PT06 and DT01~DT02 are summarized in Table 1.

[0174] Table 1. Raw material formulations of waterborne polyaniline anticorrosive coatings

[0175]

[0176] Test Example 1

[0177] The waterborne polyaniline anticorrosive coatings PT01~PT06, DT01 and DT02 prepared in the examples and comparative examples are sprayed on a steel plate with a thickness of 3 mm that has been previously sandblasted to remove rust, and after being left at room temperature for 7 days, the dry film thickness of the coating is 80±5 µm, and the salt spray performance and adhesion performance tests are carried out.

[0178] Salt spray performance test method: tested according to the national standard GB10125-2012, F-90 type salt spray corrosion resistance testing machine (Qingdao Yitai Instrument and Meter Co., Ltd.); carried out in a salt spray chamber containing a sodium chloride solution with a concentration of 50 g / L, the solution pH value is 6.5~7.2, and the test temperature is fixed at (35±2) ℃. Salt spray resistance performance requirements: no blistering, cracking, peeling, rusting.

[0179] Adhesion test method: tested according to GB / T5210 pull-off method, the obtained data is tested by pull-off method through Positest AT-M20 mm type pull-off instrument, at least 3 points for each sample, and the adhesion data is the average value of 3 points.

[0180] The waterborne polyaniline anticorrosive coatings PT01~PT06, DT01 and DT02 are sprayed on a tinplate that has been sanded, and after being cured at room temperature for 7 days, the dry film thickness of the coating is 80±5 µm, and the paint film impact resistance and paint film bending performance tests are carried out.

[0181] Paint film impact resistance test method: tested according to GB / T 1732 standard.

[0182] Paint film bending performance test method: tested according to GB / T 6742 standard.

[0183] The test data of the paint film formed by the waterborne polyaniline anticorrosive coatings PT01~PT06, DT01 and DT02 are summarized in Table 2.

[0184] Table 2. Test data of anticorrosive coatings PT01~PT06, DT01 and DT02

[0185]

[0186] As can be seen from Table 2, the paint films PT01-PT06 prepared in the examples have stronger adhesion and long-term corrosion resistance than the paint films DT01 and DT02 prepared in the comparative examples.

[0187] The above description is merely preferred specific embodiments of the present application, but the protection scope of the present application is not limited thereto, and any person skilled in the art can make equivalent replacements or changes to the technical solutions and the inventive concept of the present application within the technical scope disclosed by the present application, which should be covered within the protection scope of the present application.

Claims

1. A waterborne polyaniline polymer, characterized in that, It has the structure of formula (I): （I）； Where n is an integer from 1 to 500, 0 < x < 1, and y is an integer from 0 to 4; R1 is selected from hydrogen or C1~C1. 10 Alkyl groups; R — Selected from the following structures: 、 、 ； m is an integer from 1 to 15.

2. A method for preparing the waterborne polyaniline polymer according to claim 1, characterized in that, include: a) The aniline compound shown in formula (II), the initiator, and aluminum tripolyphosphate undergo a polymerization reaction to obtain a polyaniline compound; b) The polyaniline compound obtained in step a) is mixed with an aqueous dopant and then subjected to a modification reaction to obtain the aqueous polyaniline polymer shown in formula (I); (II); The aqueous dopant is selected from those containing R. — Acid; （I）； Where n is an integer from 1 to 500, 0 < x < 1, and y is an integer from 0 to 4; R1 is selected from hydrogen or C1~C1. 10 Alkyl groups; R — Selected from the following structures: 、 、 。 3. The preparation method according to claim 2, characterized in that, The molar ratio of the aniline compound, the initiator, and aluminum dihydrogen tripolyphosphate is (91~220):(67~400):(0.47~1.95). The mass ratio of the aqueous dopant to the aniline compound is 1:0.3~3.

4. A water-based anti-corrosion coating, characterized in that, Includes component A and component B; Component A comprises the following components by mass: The aqueous polyaniline polymer of claim 1 or the aqueous polyaniline polymer prepared by the preparation method of any one of claims 2 and 3 comprises 0.5-4 parts, aqueous epoxy resin 20-120 parts, water 5-20 parts, aqueous film-forming cosolvent 10-30 parts, titanium dioxide 5-20 parts, talc 8-40 parts, precipitated barium sulfate 3-15 parts, aqueous defoamer 0.3-3 parts, and aqueous dispersant 0.4-3 parts; Component B comprises the following components by mass: 65-90 parts of water-based epoxy curing agent; 0.3-0.7 parts of flash rust inhibitor.

5. The water-based anti-corrosion coating according to claim 4, characterized in that, The mass ratio of component A to component B is 1 to 5:

1.

6. The water-based anti-corrosion coating according to claim 4, characterized in that, The waterborne epoxy resin is selected from at least one of Huntsman PZ3961-1, Shanghai Huayi STW606, Shanghai Huayi STW6521 and Shanghai Huayi STW6522.

7. The water-based anti-corrosion coating according to claim 4, characterized in that, The aqueous defoamer is selected from at least one of BYK-052, BYK-088, BYK-1752, BYK-053, BYK-051, BYK-057, BYK-077, BYK-066N and BYK-1790.

8. The water-based anti-corrosion coating according to claim 4, characterized in that, The waterborne epoxy curing agent is selected from at least one of Huntsman AD3986, Huntsman AD3987, Huntsman AD38-1, Shanghai Huayi STW703C, and Shanghai Huayi STW703D.

9. The water-based anti-corrosion coating according to claim 4, characterized in that, The aqueous dispersant is selected from at least one of Disperbyk-103, Disperbyk-108, Disperbyk-115, Disperbyk-130, Disperbyk-111, Disperbyk-180, Disperbyk-160, Disperbyk-162, Disperbyk-164 and Disperbyk-182.

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