Preservative composition and application thereof in anticorrosive high-temperature-resistant coating

Abstract

The invention relates to the technical field of coatings, in particular to a preservative composition and application thereof in anti-corrosion and high-temperature-resistant coatings. The anti-corrosion and high-temperature-resistant coating prepared by the invention overcomes the technical problems that the coating is poor in anti-corrosion performance as a protective layer of a metal part, the protective performance is reduced under a high-temperature condition, and the drying time of the coating is too long or too short. A preservative composition is formed by synthesizing a preservative I, a preservative II and a preservative III, and the preservative composition is mixed with epoxy resin, a curing agent, pigments, fillers, auxiliaries and deionized water to obtain the anticorrosive high-temperature-resistant coating. The preservative composition is further obtained by synthesizing the preservative I and the preservative II, the epoxy resin and the hydrotalcite-based curing agent are synthesized and reasonably matched with the pigment filler, the auxiliary and the deionized water, and the obtained anticorrosive high-temperature-resistant coating is good in high-temperature resistance and corrosion resistance and moderate in curing time.

Description

Technical Field

[0001] The present invention relates to the technical field of coatings, in particular to an antiseptic composition and application thereof in antiseptic and high temperature resistant coatings. Background Art

[0002] Nowadays, modern industry and science and technology go hand in hand, which has led to an increasing number of equipment used in extreme environments. Metal materials, such as magnesium-aluminum alloy, iron, aluminum, etc., are inevitably used in the manufacturing materials of these equipment. These materials are subject to high-temperature oxidation corrosion and chemical corrosion in contact with liquids during use, which affects the normal industrial production of the equipment. Therefore, the application of anti-corrosion and high-temperature resistant coatings is very extensive. The coating is applied or sprayed on the surface of the protected metal to protect the material from corrosion.

[0003] Anticorrosive and high temperature resistant coatings can be generally divided into three categories, including inorganic, organic, and organic-inorganic composite coatings. Among them, inorganic coatings include silicates, phosphates, hydrotalcite and silica sol high temperature resistant coatings, such as patent CN111073503B discloses a high temperature resistant and high emissivity anticorrosive coating, which is prepared by using cordierite powder, ferroferric oxide powder, chromium oxide powder, cobalt oxide powder, ferromanganese spinel powder, borosilicate glass powder, low melting point glass powder modified graphene, binder, dispersant, wetting agent, thickener and defoamer as raw materials. The anticorrosive coating takes into account both low temperature and high temperature anticorrosion performance while having a high infrared emissivity. However, inorganic coatings have poor bonding strength, are prone to cracking, and their anticorrosion performance decreases after long-term use.

[0004] Organic coatings are mainly divided into heterocyclic and elemental types, and the elemental types are further divided into organic silicon, organic fluorine and organic titanium coatings. Organic silicon coatings are widely used. For example, patent CN113321958B discloses a preservative composition and its application in anti-corrosion and high-temperature resistant coatings. 5-chloro-2-methyl-4-isothiazoline-3-one, acid binding agent, catalyst and alcohol are used as raw materials to prepare cassonon derivatives, which are combined with cyclodextrin to form a preservative composition, which is applied to coatings containing organic silicone resins. The final anti-corrosion and high-temperature resistant coating has good alkali corrosion resistance and good corrosion resistance at a maximum temperature of 60°C. However, using only organic silicone resin as the main component of the coating cannot withstand high-temperature conditions above 200°C.

[0005] Organic-inorganic composite coatings have the excellent properties of both organic and inorganic coatings and are widely used. Patent CN110698967B discloses a high temperature resistant, anti-aging low VOC polyurethane anticorrosive coating, which improves the corrosion resistance of the coating by combining the organic components of polyphenyl ring polyester polyol resin and multifunctional polyisocyanate with the inorganic components of nano titanium dioxide and nano silicon carbide, and has a maximum heat resistance temperature of 200°C.

[0006] Patent CN114181613B discloses a high-temperature resistant, heat-insulating, and anti-corrosion coating and a preparation method thereof, which uses tetraethyl orthosilicate, polysilazane precursor, silicone resin, siloxane-modified strontium aluminum polyphosphate, organic zinc-modified strontium potassium polyphosphate, basalt chopped fibers, heat-insulating fillers, and diluents as the coating's ingredients. The coating has good heat-insulating and anti-corrosion properties, but needs to be dried at 200°C for 3 hours, has a high curing temperature, and has a long curing time.

[0007] At present, there is no anticorrosive coating in the prior art that is resistant to high temperatures, has good bonding performance with the protected substrate, has a moderate curing time, and has good corrosion resistance.

[0008] To this end, an antiseptic composition and application of the antiseptic composition in an antiseptic and high temperature resistant coating are proposed. Summary of the invention

[0009] The purpose of the present invention is to provide an anticorrosive composition and its application in an anticorrosive and high-temperature resistant coating. The anticorrosive composition is prepared by synthesizing anticorrosive one and anticorrosive two, and further preparing the anticorrosive composition with anticorrosive three. The anticorrosive and high-temperature resistant coating obtained by synthesizing an epoxy resin and a hydrotalcite-based curing agent and reasonably mixing them with pigments, fillers, additives and deionized water has good high temperature resistance, good anticorrosion performance and moderate curing time.

[0010] To achieve the above object, the present invention provides the following technical solutions:

[0011] In one aspect, the present invention provides a preservative composition, comprising preservative one, preservative two and preservative three;

[0012] The preparation method of the preservative is as follows: 11.5-14.0 parts of mercaptobenzothiazolecarbonitrile are dissolved in ethanol and dimethylformamide to prepare a mercaptobenzothiazolecarbonitrile solution; ferric bromide and sodium hydroxide solution are added to the mercaptobenzothiazolecarbonitrile solution, and reflux reaction is performed to obtain a hydroxylated mercaptobenzothiazolecarbonitrile solution; a catalyst and an aqueous solution of an amine compound are added to the hydroxylated mercaptobenzothiazolecarbonitrile solution to react to obtain a mercaptobenzothiazolecarbonitrile amine solution; the amount of the amine compound is 1.8-11.4 parts; 16.6-39.5 parts of phytic acid and concentrated sulfuric acid are added to the mercaptobenzothiazolecarbonitrile amine solution, and after reaction, the solution is filtered, washed with water, dried, and redispersed, and after heating, γ-aminopropyltriethoxysilane is added to react to obtain the preservative;

[0013] Taking mercaptobenzothiazolecarbonitrile as the starting reactant, under the action of ferric bromide catalyst, heating and sodium hydroxide, the hydroxyl group replaces the bromine element in the starting material, and then under the action of a condensing agent, the hydroxyl group reacts with the amino group at one end of the amine molecule to introduce the imine into the system, which synergistically improves the corrosion resistance with the mercapto group; then the unreacted amino group at the other end of the amine molecule reacts with the phosphoric acid in phytic acid, thereby imparting the corrosion inhibition effect of phytic acid to the preservative one; finally, a silane coupling agent is used to cap the unreacted phosphoric acid in phytic acid, thereby improving the heat resistance and water resistance of the anti-corrosion one.

[0014] The preservative three is selected from one or two of 2-mercaptobenzothiazole, 2-chloro-1,3-dimethylimidazoline chloride and zinc molybdate;

[0015] The addition of 2-mercaptobenzothiazole and 2-chloro-1,3-dimethylimidazoline chloride can form a protective film on the surface of the protected metal, thereby improving the chemical stability of the metal and delaying the corrosion process. When the mixing of impurity metals forms electrochemical corrosion, the addition of zinc molybdate can replace the protected metal, corrode and consume the metal in the zinc molybdate, thereby protecting the substrate.

[0016] The dosage ratio of the preservative 1, the preservative 2 and the preservative 3 is 2-9:2-7:1-6.

[0017] Preferably, the amine compound is one of diethylamine, diethylenetriamine, triethylenetetramine, tetraethylenepentamine and pentaethylenehexamine.

[0018] Preferably, the preparation method of the second preservative is as follows: add 2-(2-mercaptobenzothiazole)succinic acid, the ethanol and the dimethylformamide into a reaction bottle, stir to dissolve and then heat to 55°C to obtain a succinic acid solution; add 0.2 parts of 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide and 0.1 parts of N-hydroxysuccinimide to the succinic acid solution, add the phytic acid and the concentrated sulfuric acid after heating, filter after reaction, wash with water, dry, and redisperse, add the γ-aminopropyltriethoxysilane after heating to react to obtain the second preservative.

[0019] On the other hand, the present invention provides an application of a preservative composition in an anti-corrosion and high-temperature resistant coating; the anti-corrosion and high-temperature resistant coating is prepared by uniformly mixing 58-65 parts of an epoxy resin and 0-46 parts of a preservative composition to obtain component one; 24-30 parts of a curing agent, 18-24 parts of a pigment filler, 8.6-9.5 parts of an auxiliary agent and 9.5-12 parts of deionized water are mixed to obtain component two; and component one and component two are mixed, sprayed at high temperature, and cured to obtain the obtained component.

[0020] Preferably, the preparation method of the epoxy resin is as follows: 34.5-40.0 parts of epoxyethyl methoxypropyl disiloxane are added to a three-necked flask, 0.5% by mass of sodium hydroxide solution is added thereto, the pH of the system is adjusted to 10, and then the temperature is raised to 70°C to obtain a reaction liquid; ethylenediamine is added to the reaction liquid, and reflux reaction is carried out under nitrogen protection to obtain an epoxy resin precursor; a 40% by mass citric acid aqueous solution is added to the epoxy resin precursor, and the reflux reaction is continued for 5 hours to obtain an epoxy resin intermediate; the amount of citric acid in the citric acid aqueous solution is 38.0-41.2 parts; tetrabutylammonium bromide and 60.5-172 parts of diethylene oxide are added to the epoxy resin intermediate, and after reflux reaction for 12 hours, filtering, washing, and vacuum drying are obtained to obtain the epoxy resin.

[0021] With epoxyethyl methoxypropyl disiloxane as a basic raw material, the epoxy group is ring-opened under alkaline conditions and heating, the hydroxyl group formed by the ring-opening reacts with the amino group of ethylenediamine, and the unreacted amino group reacts with the hydroxyl group or carboxyl group of citric acid in the subsequent preparation process. After citric acid is grafted, the carboxyl group of citric acid reacts with the hydroxyl group formed by an epoxy group in diethylene oxide under the action of a catalyst, thereby preparing an epoxy resin.

[0022] Preferably, the preparation method of the curing agent is as follows: dissolving trisodium phosphate dodecahydrate in deionized water to obtain a trisodium phosphate solution; heating the trisodium phosphate solution to 50° C., adding magnesium aluminum hydrotalcite powder thereto, vigorously stirring for 0.5 h and homogenizing to obtain a dispersion; filtering the dispersion, repeatedly washing with the deionized water and ethanol, and then drying at 70° C. for 5 h to obtain phosphate hydrotalcite;

[0023] The phosphated talc is dispersed in ethanol to obtain a phosphated talc solution; the 3-mercaptocarboxylic acid solution is slowly added to the phosphated talc solution, and stirred while adding dropwise, and stirred at 500 rpm for 2 hours to obtain a modified phosphated talc solution; ethylenediamine and dibutyltin dilaurate are added to the modified phosphated talc solution, and the temperature is raised to 70° C., and refluxed for 4 hours to obtain a curing agent precursor solution; diethylene oxide is added to the curing agent precursor solution, and refluxed for 15 hours to obtain a curing agent intermediate solution; the ethylenediamine is added to the curing agent intermediate solution, and the reaction is continued for 8 hours, and then the solution is cooled to room temperature, and the solvent and excess impurities are removed to obtain the curing agent.

[0024] Preferably, the amount of the phosphate talc is 52-70 parts; the amount of the 3-mercaptocarboxylic acid is 13.5-16.0 parts; and the amount of the dioxirane is 75.0-85.5 parts.

[0025] Phosphates can form a film-forming substance on the surface of the metal to protect it, thus playing a role in corrosion inhibition. Hydrotalcite is composed of a series of two-dimensional fragments with negative charges, which form a hydrotalcite complex with a porous structure. Due to the repulsive effect between opposite charges in the two-dimensional structure, they will be arranged in an orderly manner, thus producing a binary electron layer paint surface. The negatively charged surface and the positively charged surface of the paint surface can resist the invasion of corrosive anions and cations respectively. The phosphate hydrotalcite prepared together has an anti-corrosion effect.

[0026] In addition, the surface of phosphate talc is modified by using 3-mercaptocarboxylic acid, the carboxyl group is subsequently reacted and connected with ethylenediamine, the ethylenediamine is then connected with diethylene oxide, and finally reacted with ethylenediamine to obtain a curing agent.

[0027] Preferably, the ratio of mica powder, glass flakes and titanium dioxide in the pigment filler is 1:2:1.

[0028] Preferably, the ratio of sepiolite, bentonite, GT-50, aminohexadecanol monomethyl ether, sodium silicate, tributyl phosphate and Tween 20 in the auxiliary agent is 1-3:2-3:1-1.4:1-1.6:0.6-0.9:0.4:0.8.

[0029] Preferably, the anticorrosive composition is used in an anticorrosive and high temperature resistant coating; the anticorrosive and high temperature resistant coating comprises the anticorrosive composition, the epoxy resin, the curing agent, the pigment and filler and the auxiliary agent; the anticorrosive composition is any one of the above; the corrosion time of the anticorrosive and high temperature resistant coating in NSS is 350-720h, the corrosion time in AASS test is 400-650h, and the corrosion time in CASS test is 240-620h; the corrosion resistance time of the anticorrosive and high temperature resistant coating after NSS test is 170-750h, and the corrosion resistance time after AASS test is 250-68 0h, the corrosion resistance time after CASS test is 220-660h; the surface drying time of the anti-corrosion and high temperature resistant coating is 6-45min, and the actual drying time is 0.5-5h; the corrosion resistance time after CASS test is 250-680h; the corrosion resistance time after CASS test at high temperature is 120-630h; the corrosion resistance time of the anti-corrosion and high temperature resistant coating is 230-640h after CASS test, and the corrosion resistance time after CASS test at high temperature is 180-630h; the corrosion resistance time of the anti-corrosion and high temperature resistant coating is 600-650h after CASS test, and the corrosion resistance time after CASS test at high temperature is 570-630h. Compared with the prior art, the beneficial effects of the present invention are:

[0030] 1. The present invention uses mercaptobenzothiazolecarbonitrile, amine compounds, phytic acid and silane coupling agent as main reaction raw materials to prepare anticorrosive agent 1, and the anticorrosive and high temperature resistant coating prepared by anticorrosive agent 1 has good anticorrosion test performance in neutral salt spray test, acetic acid salt spray test and copper accelerated acetic acid salt spray test. By using mercaptobenzothiazolecarbonitrile as the starting reactant, the sulfhydryl group, imino group and imino group in the amine compound molecule and phytic acid synergistically play a good anticorrosive effect; in addition, the cyano group on the benzene ring in the synthesized anticorrosive agent 1 will decompose into amino group and imino group when encountering high temperature and water molecules during the use of the coating, thereby curing the epoxy resin again, further improving the anticorrosive property.

[0031] 2. Preservative one and preservative two are prepared and used in combination with preservative three to form an anti-corrosion composition. By controlling the amount of the preservative composition in the anti-corrosion and high-temperature resistant coating, changing the type of preservative three and the dosage ratio of preservative one, preservative two and preservative three, the obtained anti-corrosion and high-temperature resistant coating has good anti-corrosion properties.

[0032] 3. The present invention uses epoxyethyl methoxypropyl disiloxane, ethylenediamine, citric acid and diethylene oxide as raw materials, changes the dosage of each raw material component, and obtains epoxy resin for preparing anticorrosive and high temperature resistant coatings. The surface drying time and actual drying time of the coating are suitable. In addition, after being subjected to high temperature, the corrosion time is reduced slightly in the anticorrosion test. By preparing the epoxy resin with a branched structure and introducing silane and long-chain ether alkane, the coating has good heat resistance and corrosion resistance.

[0033] 4. Phosphate-salted talc is prepared and surface-modified, and used as a carrier of a curing agent. On the one hand, the amino and thiol groups in the curing agent are ring-opened and cured with the epoxy groups in the epoxy resin, and on the other hand, the inorganic compound of phosphate-salted talc is introduced into the organic system through chemical bonds. The compatibility of phosphate-salted talc with epoxy resin is enhanced, the stability of epoxy resin is further improved, and finally the heat resistance and corrosion resistance of the anti-corrosion and high-temperature resistant coating are improved.

[0034] 5. Component 1 is formed by mixing epoxy resin and preservative composition; component 2 is formed by mixing curing agent, pigment, additive and deionized water; component 1 and component 2 are mixed under construction conditions to obtain an anticorrosive and high temperature resistant coating. By changing the amount of the four components in component 2 and the composition ratio of the raw materials in the additive, the obtained anticorrosive and high temperature resistant coating has good anticorrosion performance and high temperature resistance. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] Figure 1 This is a graph showing the anti-corrosion performance test results of the anti-corrosion and high-temperature resistant coating of Example 57 of the present invention. DETAILED DESCRIPTION

[0036] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0037] See also Figure 1 The present invention provides a preservative composition and its application in an anticorrosive and high temperature resistant coating, and the technical scheme is as follows:

[0038] The substance information involved in the present invention is as follows:

[0039] Ethyl methoxypropyl disiloxane CAS: 126-80-7; Diethylene oxide CAS: 3454-29-3; Diethylamine CAS: 109-89-7; Diethylenetriamine CAS: 111-40-0; Triethylenetetramine CAS: 112-24-3; Tetraethylenepentamine CAS: 112-57-2; Pentaethylenehexamine CAS: 4067-16-7; 2-Mercaptobenzothiazole CAS: 149-30-4; 2-Chloro-1,3-diamine Methylimidazoline chloride CAS: 37091-73-9; 3-mercaptocarboxylic acid CAS: 14623-54-2; phytic acid CAS: 83-86-3; γ-aminopropyltriethoxysilane CAS: 919-30-2; 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide CAS: 1892-57-5; N-hydroxysuccinimide CAS: 6066-82-6; mercaptobenzothiazolecarbonitrile CAS: 1242336-64-6.

[0040] Example 1

[0041] 13.6 parts of mercaptobenzothiazolecarbonitrile, 100 parts of ethanol and 50 parts of dimethylformamide are added to a reaction bottle, stirred and dissolved, and then heated to 55°C to obtain a mercaptobenzothiazolecarbonitrile solution; 0.1 parts of ferric bromide and 21 parts of 20% sodium hydroxide solution by mass are added thereto, and refluxed for 6 hours to obtain a hydroxylated mercaptobenzothiazolecarbonitrile solution; then 0.3 parts of a catalyst are added in sequence; the ratio of EDC (1-(3-dimethylaminopropyl)-3-ethylcarbodiimide) and NHS (N-hydroxysuccinimide) in the catalyst is 2:1, and after mixing, an aqueous solution of amine compounds is added, and the reaction is carried out for 5 hours to obtain a mercaptobenzothiazolecarbonitrile amine solution; wherein the amine compound in the aqueous solution of the amine compound is The ratio of parts to water is 1:100; the amount of amine compound used is 1.8 parts; the amine compound is diethylamine; the mercaptobenzothiazolecarbonitrile solution is heated to 65°C, 16.6 parts of phytic acid and 0.05 parts of concentrated sulfuric acid are added thereto, and the reaction is carried out for 10 hours to obtain a mercaptobenzothiazolecarbonitrile amine grafted phytic acid solution; the mercaptobenzothiazolecarbonitrile amine grafted phosphoric acid solution is filtered, washed with water, and dried to obtain mercaptobenzothiazolecarbonitrile amine grafted phytic acid; the mercaptobenzothiazolecarbonitrile amine grafted phytic acid is redispersed in 200 parts of ethanol, the temperature is raised to 65°C, 60.2 parts of γ-aminopropyltriethoxysilane and 0.24 parts of catalyst are added, refluxed for 12 hours, then cooled to room temperature, filtered, washed and dried to obtain preservative one.

[0042] Example 2

[0043] 7.2 parts of 2-(2-mercaptobenzothiazole)succinic acid, 100 parts of ethanol and 50 parts of dimethylformamide were added to a reaction bottle, stirred and dissolved, and then heated to 55°C to obtain a succinic acid solution; 0.3 parts of a catalyst was added thereto; the ratio of EDC to NHS in the catalyst was 2:1, and after mixing, an aqueous solution of amine compounds was added, and the reaction was performed for 5 hours to obtain a mercaptobenzothiazolecarbonitrile solution; the ratio of amine compounds to water in the aqueous solution of amine compounds was 1:100; the amount of tetraethylenepentamine was 11.4 parts; the mercaptobenzothiazolecarbonitrile solution was added thereto. The liquid is heated to 65°C, 39.5 parts of phytic acid and 0.05 parts of concentrated sulfuric acid are added thereto, and the reaction is carried out for 10 hours to obtain a solution of mercaptobenzothiazolecarbonitrile amide grafted phytic acid; the solution of mercaptobenzothiazolecarbonitrile amide grafted phosphoric acid is filtered, washed with water, and dried to obtain mercaptobenzothiazolecarbonitrile amide grafted phytic acid; the mercaptobenzothiazolecarbonitrile amide grafted phytic acid is redispersed in 200 parts of ethanol, the temperature is raised to 65°C, 60.2 parts of γ-aminopropyltriethoxysilane and 0.24 parts of catalyst are added thereto, refluxed for 12 hours, and then cooled to room temperature, filtered, washed, and dried to obtain preservative II.

[0044] Example 3-13

[0045] Different from Example 1, during the preparation process, the preparation conditions of preservative 1 were changed, as shown in Table 1.

[0046] Table 1 Preservatives - Changes in preparation conditions

[0047]

[0048]

[0049] 36.3 parts of epoxyethyl methoxypropyl disiloxane are added to a three-necked flask, and a sodium hydroxide solution with a mass fraction of 0.5% is added thereto, and the pH of the system is adjusted to 10, and then the temperature is raised to 70°C to obtain a reaction liquid; 14.7 parts of ethylenediamine are added to the reaction liquid, and the reaction is refluxed for 8 hours under nitrogen protection to obtain an epoxy resin precursor; a citric acid aqueous solution with a mass fraction of 40% is added to the epoxy resin precursor, and the reflux reaction is continued for 5 hours to obtain an epoxy resin intermediate; the amount of citric acid in the citric acid aqueous solution is 38.5 parts; 0.05 parts of tetrabutylammonium bromide and 85.5 parts of diethylene oxide are added to the epoxy resin intermediate, and the reaction is refluxed for 12 hours, and then filtered, washed, and vacuum dried to obtain an epoxy resin.

[0050] 95.6 parts of trisodium phosphate dodecahydrate are dissolved in 500 parts of water to obtain a trisodium phosphate solution; the trisodium phosphate solution is heated to 50°C, 5.1 parts of magnesium aluminum hydrotalcite powder is added thereto, the mixture is vigorously stirred for 0.5 h and homogenized to obtain a dispersion; the dispersion is filtered, repeatedly washed with deionized water and ethanol, and then dried at 70°C for 5 h to obtain phosphate hydrotalcite.

[0051] 60 parts of phosphated talc are dispersed in ethanol to obtain a phosphated talc solution; the ratio of phosphated talc to ethanol is 1:100; 3-mercaptocarboxylic acid solution is slowly added to the phosphated talc solution, stirring while adding, and stirring at 500 rpm for 2 hours to obtain a modified phosphated talc solution; the ratio of 3-mercaptocarboxylic acid to ethanol in the 3-mercaptocarboxylic acid solution is 1:200; the amount of 3-mercaptocarboxylic acid is 15.6 parts; 14.7 parts of ethylenediamine and 0.5 parts of dibutyltin dilaurate are added to the modified phosphated talc solution, and the temperature is raised to 70°C, and refluxed for 4 hours to obtain a curing agent precursor solution; 85.5 parts of diethylene oxide are added to the curing agent precursor solution, and refluxed for 15 hours to obtain a curing agent intermediate solution; 41.3 parts of ethylenediamine are added to the curing agent intermediate solution, and the reaction is cooled to room temperature after 8 hours, and the solvent and excess impurities are removed to obtain a curing agent.

[0052] 60 parts of epoxy resin and 40 parts of preservative composition are mixed evenly to obtain component one; the ratio of preservative one, preservative two and preservative three in the preservative composition is 9:5:6; preservative three is 2-mercaptobenzothiazole and zinc molybdate, and the ratio of the two is 3:1; 30 parts of curing agent, 20 parts of pigments and fillers, 8.8 parts of auxiliary agents and 10 parts of deionized water are mixed to obtain component two; after mixing component one and component two, they are sprayed on metal protective parts at high temperature and cured at room temperature to obtain anti-corrosion and high-temperature resistant coating. The ratio of mica powder, glass flakes and titanium dioxide in the pigments and fillers is 1:2:1; the ratio of sepiolite, bentonite, GT-50, aminohexadecanol monomethyl ether, sodium silicate, tributyl phosphate and Tween 20 in the auxiliary agents is 3:2:1:1:0.6:0.4:0.8. Except for deionized water, the above raw materials are dried to remove moisture before use.

[0053] Embodiment 14

[0054] The anti-corrosion and high temperature resistant coatings prepared by Examples 1 and 3-13 were tested for their anti-corrosion performance. The test was carried out in accordance with GB / T10125-2021 "Artificial Atmosphere Corrosion Test Salt Spray Test", and neutral salt spray test (NSS), acetic acid salt spray test (AASS) and copper accelerated acetic acid salt spray test (CASS) were carried out. The spray pressure value was 100KPa, the test temperatures were 35°C, 35°C and 50°C, respectively, and the conductivity of deionized water was 1μs / cm. During the test, the time when the coating was corroded was recorded, and the test results are shown in Table 2.

[0055] Table 2 Anticorrosion performance test results of Examples 1, 3-13

[0056] NSS(h) AASS(h) CASS(h) Example 1 350 400 240 Example 3 360 520 280 Example 4 360 460 250 Example 5 380 560 320 Example 6 370 480 250 Example 7 380 570 330 Example 8 390 500 290 Example 9 650 600 460 Example 10 460 580 360 Embodiment 11 700 620 600 Example 12 480 600 400 Example 13 720 650 620

[0057] The corrosion time of the anticorrosive and high temperature resistant coating prepared by the present invention in the neutral salt spray test is 350-720h, the corrosion time in the acetic acid salt spray test is 400-650h, and the corrosion time in the copper accelerated acetic acid salt spray test is 240-620h. The results of Examples 1, 4, 6, 8, and 10 show that with the change of the molecular type of the amine compound, the relative molecular mass increases, the amount of imino group introduced increases, the dosage increases, and the corrosion resistance time increases. Among them, the corrosion resistance of Example 10 is the best, and the corrosion time in NSS, AASS, and CASS is 460h, 580h, and 360h, respectively; wherein the corrosion resistance of the coating after the CASS test is the worst, and a primary battery is formed between the added copper and zinc, and electrochemical corrosion and chemical corrosion increase. The results of Examples 1 and 3, 4 and 5, 6 and 7, 8 and 9, 10 and 11 show that with the increase of the dosage of amine compounds and phytic acid, the corrosion resistance time basically shows an increasing trend. The results of Examples 9, 12 and 13 show that the coating of Example 13, in which the amount of mercaptobenzothiazolecarbonitrile is 14.0 parts, 11.4 parts of tetraethylenepentamine and 39.5 parts of phytic acid are added, has the best anti-corrosion effect.

[0058] Examples 15-23

[0059] Comparative Examples 1-4

[0060] Preservative 1 was prepared by the method of Example 13; preservative 2 was prepared by the method of Example 2; different from Example 13, the following preparation conditions were changed, as shown in Table 3.

[0061] Table 3 Variation of preparation conditions of preservative composition

[0062]

[0063]

[0064] Comparative Example 4

[0065] That is, only preservative three is added as the preservative composition, and preservative one and preservative two are not added.

[0066] Embodiment 24

[0067] The anti-corrosion and high temperature resistant coatings prepared in Examples 15-23 and Comparative Examples 1-4 were tested for their anti-corrosion performance. The specific test method is shown in Example 14. The final test results are shown in Table 4.

[0068] Table 4 Anticorrosion performance test results of Examples 15-23 and Comparative Examples 1-4

[0069]

[0070]

[0071] The corrosion resistance time of the anticorrosive and high temperature resistant coating prepared by the present invention is 170-750h after the NSS test, 250-680h after the AASS test, and 220-660h after the CASS test. The results of Examples 15-18 show that as the amount of the preservative composition increases, the time of occurrence of the corrosion phenomenon in the NSS test shows a trend of first increasing and then stabilizing, and the results of AASS and CASS show a trend of first increasing and then decreasing and gradually increasing. The results of Examples 17 and 19 show that the use of 2-chloro-1,3-dimethylimidazoline chloride and zinc molybdate as preservative three has the best anticorrosion performance. The results of Examples 19-23 show that the dosage ratio of preservative one, preservative two and preservative three is 7:7:6, as shown in Example 20, and the anticorrosion effect is best at this time. Comparative Example 1 does not add the preservative composition, and the corrosion resistance time of the CASS test is only 220h. Comparative Examples 2 and 3 only added one substance as preservative three, and the anticorrosion effect was lower than that of Example 19. Comparative Example 4 did not use preservative one and preservative two prepared by the present invention, and the anticorrosion effect was greatly reduced.

[0072] Examples 25-35

[0073] Comparative Examples 5 and 6

[0074] Different from Example 13, the preparation method of the epoxy resin is changed, as shown in Table 5.

[0075] Comparative Example 5

[0076] The difference from Example 13 is that epichlorohydrin is used instead of oxiranylmethoxypropyldisiloxane.

[0077] Embodiment 36

[0078] The anti-corrosion and high-temperature resistant coatings prepared in Examples 25-35 and Comparative Examples 5 and 6 were tested for surface drying and actual drying time, and the anti-corrosion performance was also tested. The anti-corrosion performance test method was carried out with reference to Example 14. The anti-corrosion performance of the coatings of the examples and comparative examples was examined by the CASS test, and the changes in the anti-corrosion performance of the CASS test after 800 hours of high temperature at 300°C were examined. The surface drying time and actual drying time of the coating were tested with reference to the standard GB / T 1728-2020 "Determination of Drying Time of Paint Film and Putty". The final test results are shown in Table 5.

[0079] The anticorrosive and high temperature resistant coating prepared by the present invention has a surface drying time of 6-45min and a practical drying time of 0.5-5h; the corrosion resistance time after the CASS test is 250-680h; and the corrosion resistance time after the CASS test at high temperature is 120-630h. The results of Examples 25-28 show that with the increase in the amount of epoxyethyl methoxypropyl disiloxane, the surface drying and practical drying times first decrease and then remain unchanged, and the anticorrosion time gradually increases, but after the anticorrosion test is carried out at high temperature, the anticorrosion time reduction value shows a trend of first decreasing and then increasing, and the anticorrosion time of Example 28 is shortened by 40h after high temperature. The results of Examples 27, 29 and 30 show that the amount of citric acid is changed, and the amount of citric acid in Example 30 is the highest, the surface drying time increases accordingly, the molecular weight of the epoxy resin obtained is the largest, and the anticorrosion time increases accordingly, but the anticorrosion time reduction value after high temperature is large, and the excessive addition of citric acid causes the presence of excess carboxyl groups in the epoxy resin, which increases the attraction to water molecules and accelerates the corrosion of the protected substrate. The results of Examples 28, 31-35 show that as the amount of dioxirane introduced increases, the surface drying and actual drying time gradually shorten, and the anti-corrosion time gradually increases. The anti-corrosion time reduction value after high temperature conditions under Example 33 is only 10 hours; the surface drying time and actual drying time of Example 35 are the shortest, which is not conducive to the actual construction process; the amount of Comparative Example 6 is too small, resulting in a decrease in anti-corrosion performance. Comparative Example 5 replaces the raw material with epichlorohydrin, and the anti-corrosion performance is the worst.

[0080] Table 5 Changes in conditions during epoxy resin preparation

[0081]

[0082] Examples 37-47

[0083] The method of Example 13 was used to prepare the preservative 1; the method of Example 2 was used to prepare the preservative 2; the method of Example 32 was used to prepare the epoxy resin; the difference from Example 13 was that the preparation method of the curing agent and the amount of the epoxy resin and the curing agent were changed. The specific preparation method is shown in Table 6.

[0084] Table 6 Preparation and dosage of curing agent, dosage of epoxy resin

[0085]

[0086] Embodiment 48

[0087] The difference from Example 45 is that the amount of phosphate talc used is 58 parts.

[0088] Embodiment 49, 50

[0089] The difference from Example 48 is that the amounts of phosphate talc used are 52 parts and 70 parts respectively.

[0090] Comparative Example 7

[0091] The difference from Example 48 is that the amount of phosphate talc used is 0 part.

[0092] Embodiment 51

[0093] The anti-corrosion and high-temperature resistant coatings prepared in Examples 37-50 and Comparative Example 7 were tested for their anti-corrosion performance. The specific testing method was referred to Example 36, and the test results are shown in Table 7.

[0094] Table 7 Anticorrosion performance test results of Examples 37-50 and Comparative Example 7

[0095]

[0096]

[0097] The results of Table 7 show that the corrosion resistance time of the anticorrosive and high temperature resistant coating prepared by the present invention is 230-640h in the CASS test, and the corrosion resistance time of the CASS test after high temperature is 180-630h. The results of Examples 37-40 show that by increasing the amount of 3-mercaptocarboxylic acid, the corrosion resistance gradually increases. The results of Examples 40-42 show that when the amount of dioxirane in Example 40 is 85.5 parts, the corrosion resistance time of the CASS test is 630h, and the corrosion resistance time of the CASS test after high temperature is 610h. The results of Examples 42-47 show that the corrosion resistance changes when the amount of curing agent or epoxy resin is changed. As shown in Example 45, when the amount of epoxy resin and curing agent is moderate, the corrosion resistance is good. The results of Examples 45 and 48-50 show that the amount of phosphate talc in Example 50 is the largest, but the corrosion resistance time of the CASS test after high temperature is the lowest, and the excessive amount leads to poor compatibility with the system. In Comparative Example 7, the curing agent was prepared without adding phosphate talc, and the corrosion resistance was the worst.

[0098] Embodiment 52

[0099] The difference from Example 45 is that in component 2, the pigment filler is 18 parts, the auxiliary agent is 8.6 parts, and the deionized water is 9.5 parts.

[0100] Embodiment 53

[0101] The difference from Example 45 is that in component 2, the pigment filler is 22 parts, the auxiliary agent is 9.0 parts, and the deionized water is 10.5 parts.

[0102] Embodiment 54

[0103] The difference from Example 45 is that in component 2, the pigment and filler are 24 parts, the auxiliary agent is 9.5 parts, and the deionized water is 12 parts.

[0104] Embodiment 55

[0105] Different from Example 45, the dosage of the auxiliary agents in component two is as follows: the ratio of sepiolite, bentonite, GT-50, aminohexadecanol monomethyl ether, sodium silicate, tributyl phosphate and Tween 20 is 1:3:1.4:1.6:0.6:0.4:0.8.

[0106] Embodiment 56

[0107] Different from Example 45, the dosage of the auxiliary agents in component two is as follows: the ratio of sepiolite, bentonite, GT-50, aminohexadecanol monomethyl ether, sodium silicate, tributyl phosphate and Tween 20 is 2.7:2:1:1:0.9:0.4:0.8.

[0108] Embodiment 57

[0109] The anti-corrosion and high temperature resistant coatings prepared in Examples 52-56 were tested for their anti-corrosion performance. The specific test method was carried out with reference to Example 36. The test results are as follows: Figure 1 shown.

[0110] like Figure 1 As shown, the corrosion protection time of the anticorrosive and high temperature resistant coating prepared by the present invention in the CASS test is 600-650h, and the corrosion protection time of the CASS test after high temperature is 570-630h. The results of Examples 52-54 show that the anticorrosive and high temperature resistant coating obtained by respectively changing the dosage of pigment filler, auxiliary agent and deionized water in component 2 has good high temperature resistance and corrosion resistance. The anti-corrosion effect of Example 54 is the best. Example 55 changes the dosage of the substance in the auxiliary agent, and the corrosion protection performance is good. Sepiolite and bentonite have the effects of improving the suspension and dispersibility of the raw materials, and giving the coating viscosity and strength; GT-50 plays a role in preventing the coating from cracking after curing; amino hexadecanol monomethyl ether and sodium silicate have a film-forming effect, accelerate the curing process of the coating, and give the coating strength; amino hexadecanol monomethyl ether has a diluting effect when added to the coating in the early stage, and participates in the curing process. In addition, the long-chain alcohol structure gives the cured coating flexibility; tributyl phosphate has a defoaming effect. Example 56 increases the amount of sodium silicate and correspondingly reduces the amount of sepiolite, so that the anti-corrosion and high-temperature resistant coating has good anti-corrosion performance.

[0111] Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A preservative composition, characterized in that: The preservative composition comprises preservative one, preservative two and preservative three; The preparation method of the preservative is as follows: 11.5-14.0 parts of mercaptobenzothiazolecarbonitrile are dissolved in ethanol and dimethylformamide to prepare a mercaptobenzothiazolecarbonitrile solution; ferric bromide and sodium hydroxide solution are added to the mercaptobenzothiazolecarbonitrile solution, and reflux reaction is performed to obtain a hydroxylated mercaptobenzothiazolecarbonitrile solution; a catalyst and an aqueous solution of an amine compound are added to the hydroxylated mercaptobenzothiazolecarbonitrile solution to react to obtain a mercaptobenzothiazolecarbonitrile amine solution; the amount of the amine compound is 1.8-11.4 parts; 16.6-39.5 parts of phytic acid and concentrated sulfuric acid are added to the mercaptobenzothiazolecarbonitrile amine solution, and after reaction, the solution is filtered, washed with water, dried, and redispersed, and after heating, γ-aminopropyltriethoxysilane is added to react to obtain the preservative; The preservative three is selected from one or two of 2-mercaptobenzothiazole, 2-chloro-1,3-dimethylimidazoline chloride and zinc molybdate; The dosage ratio of the preservative 1, the preservative 2 and the preservative 3 is 2-9:2-7:1-6.

2. A preservative composition according to claim 1, characterized in that: The amine compound is one of diethylamine, diethylenetriamine, triethylenetetramine, tetraethylenepentamine and pentaethylenehexamine.

3. A preservative composition according to claim 1, characterized in that: The preparation method of the preservative II is as follows: add 2-(2-mercaptobenzothiazole)succinic acid, the ethanol and the dimethylformamide into a reaction bottle, stir to dissolve and then heat to 55°C to obtain a succinic acid solution; add 0.2 parts of 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide and 0.1 parts of N-hydroxysuccinimide to the succinic acid solution, add the phytic acid and the concentrated sulfuric acid after heating, filter after reaction, wash with water, dry, and redisperse, add the γ-aminopropyltriethoxysilane after heating to react and obtain the preservative II.

4. Application of an antiseptic composition in an antiseptic and high temperature resistant coating, characterized in that: Application of the preservative composition in anti-corrosion and high temperature resistant coatings; the anti-corrosion and high temperature resistant coatings are prepared by uniformly mixing 58-65 parts of epoxy resin and 0-46 parts of the preservative composition to obtain component one; 24-30 parts of a curing agent, 18-24 parts of a pigment filler, 8.6-9.5 parts of an auxiliary agent and 9.5-12 parts of deionized water to obtain component two; the component one and the component two are mixed, sprayed at high temperature and cured to obtain the coating.

5. The use of the preservative composition according to claim 4 in an anticorrosive and high temperature resistant coating, characterized in that: The preparation method of the epoxy resin is as follows: 34.5-40.0 parts of epoxyethyl methoxypropyl disiloxane are added to a three-necked flask, a sodium hydroxide solution with a mass fraction of 0.5% is added thereto, the pH of the system is adjusted to 10, and then the temperature is raised to 70°C to obtain a reaction liquid; ethylenediamine is added to the reaction liquid, and a reflux reaction is carried out under nitrogen protection to obtain an epoxy resin precursor; a citric acid aqueous solution with a mass fraction of 40% is added to the epoxy resin precursor, and the reflux reaction is continued for 5 hours to obtain an epoxy resin intermediate; the amount of citric acid in the citric acid aqueous solution is 38.0-41.2 parts; tetrabutylammonium bromide and 60.5-172 parts of diethylene oxide are added to the epoxy resin intermediate, and after reflux reaction for 12 hours, the epoxy resin is filtered, washed, and vacuum dried to obtain the epoxy resin.

6. Use of the preservative composition according to claim 4 in an anticorrosive and high temperature resistant coating, characterized in that: The preparation method of the curing agent is as follows: dissolving trisodium phosphate dodecahydrate in deionized water to obtain a trisodium phosphate solution; heating the trisodium phosphate solution to 50° C., adding magnesium aluminum hydrotalcite powder thereto, vigorously stirring for 0.5 h and homogenizing to obtain a dispersion; filtering the dispersion, repeatedly washing with the deionized water and ethanol, and then drying at 70° C. for 5 h to obtain phosphate hydrotalcite; The phosphated talc is dispersed in ethanol to obtain a phosphated talc solution; the 3-mercaptocarboxylic acid solution is slowly added to the phosphated talc solution, and stirred while adding dropwise, and stirred at 500 rpm for 2 hours to obtain a modified phosphated talc solution; ethylenediamine and dibutyltin dilaurate are added to the modified phosphated talc solution, and the temperature is raised to 70° C., and refluxed for 4 hours to obtain a curing agent precursor solution; diethylene oxide is added to the curing agent precursor solution, and refluxed for 15 hours to obtain a curing agent intermediate solution; the ethylenediamine is added to the curing agent intermediate solution, and the reaction is continued for 8 hours, and then the solution is cooled to room temperature, and the solvent and excess impurities are removed to obtain the curing agent.

7. Use of the preservative composition according to claim 6 in an anticorrosive and high temperature resistant coating, characterized in that: The amount of the phosphate talc is 52-70 parts; the amount of the 3-mercaptocarboxylic acid is 13.5-16.0 parts; and the amount of the dioxirane is 75.0-85.5 parts.

8. The use of the preservative composition according to claim 4 in an anticorrosive and high temperature resistant coating, characterized in that: The proportion of mica powder, glass flakes and titanium dioxide in the pigment and filler is 1:2:

1.

9. The use of the preservative composition according to claim 4 in an anticorrosive and high temperature resistant coating, characterized in that: The proportion of sepiolite, bentonite, GT-50, aminohexadecanol monomethyl ether, sodium silicate, tributyl phosphate and Tween 20 in the auxiliary agent is 1-3:2-3:1-1.4:1-1.6:0.6-0.9:0.4:0.

8.

10. The use of the preservative composition according to claim 4 in an anticorrosive and high temperature resistant coating, characterized in that: The anticorrosive and high temperature resistant coating comprises the anticorrosive composition, the epoxy resin, the curing agent, the pigment and the additive; the anticorrosive composition is any one of claims 1 to 3; the corrosion time of the anticorrosive and high temperature resistant coating in NSS is 350-720h, the corrosion time in AASS test is 400-650h, and the corrosion time in CASS test is 240-620h; the corrosion resistance time of the anticorrosive and high temperature resistant coating after NSS test is 170-750h, the corrosion resistance time after AASS test is 250-680h, and the corrosion resistance time after CASS test is 240-620h. The corrosion resistance time of the anti-corrosion and high-temperature resistant coating is 220-660h; the surface drying time of the anti-corrosion and high-temperature resistant coating is 6-45min, and the actual drying time is 0.5-5h; the corrosion resistance time after the CASS test is 250-680h; the corrosion resistance time of the CASS test after high temperature is 120-630h; the corrosion resistance time of the anti-corrosion and high-temperature resistant coating is 230-640h in the CASS test, and the corrosion resistance time of the CASS test after high temperature is 180-630h; the corrosion resistance time of the anti-corrosion and high-temperature resistant coating is 600-650h in the CASS test, and the corrosion resistance time of the CASS test after high temperature is 570-630h.

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