High-flash-point safe alkyd anticorrosive paint

Abstract

The invention discloses a high-flash-point safe alkyd anticorrosive coating, and belongs to the technical field of anticorrosive coatings. The invention is used for solving the problems of low flash point and to-be-improved safety of alkyd anticorrosive paint in the prior art. Wherein the modified alkyd resin emulsion, the high-flash-point solvent, the titanium dioxide, the light stabilizer, the antioxidant, the flatting agent and the defoaming agent are mixed and uniformly stirred to obtain the component A; the component A and the component B are mixed according to the proportion to obtain the high-flash-point safe alkyd anticorrosive paint. The high-flash-point safe alkyd anticorrosive paint prepared by the invention not only has the advantages of high flash point and low volatile substance content, but also has good corrosion resistance, self-cleaning effect and fireproof performance, and the application range is further expanded.

Description

Technical Field

[0001] The invention relates to the technical field of anti-corrosion coatings, and in particular to a high-flash point safe alkyd anti-corrosion coating. Background Art

[0002] Alkyd resin has the advantages of abundant raw material sources and low cost. The coatings prepared from it have good coating gloss, hardness and durability. Alkyd resin coatings can be simply divided into solvent-based alkyd coatings and water-based alkyd coatings. Among them, solvent-based alkyd coatings have a high VOC (volatile organic compound) content, and a large amount of organic solvents are discharged during the construction process, which has adverse effects on the environment and construction personnel. The synthesis methods of water-based alkyd resins include internal emulsification and external emulsification. The internal emulsification method refers to the introduction of hydrophilic groups directly on the molecular chain segments during the synthesis stage of alkyd resins to obtain water-soluble alkyd resins; the external emulsification method uses the first synthesis of solvent-based alkyd resins, and then adds water and emulsifiers under high-speed stirring to synthesize alkyd resin emulsions by phase inversion. Water-based alkyd resins have the characteristics of low pollution, low energy consumption and good comprehensive coating performance, but the flash point of water-based alkyd resins is not high, which limits their application. However, its varnish has a slow drying speed and poor water resistance and solvent resistance. Traditional alkyd resin coatings use long-oil semi-drying soybean oil alkyd resin as the main film-forming material, with 200# solvent oil, pigments, fillers, and driers. Traditional alkyd resin coatings need to be diluted with a large amount of organic solvents to meet construction conditions, so the VOC content is high, and the user's subsequent environmental protection treatment costs and pressure are high. Considering the concept of environmental protection, people need an environmentally friendly, high-flash point alkyd anti-corrosion coating.

[0003] Chinese patent CN110305571B discloses a method for preparing a high-performance alkyd resin anticorrosive varnish, which comprises a film-forming substance composed of a drying long-oil alkyd resin, a drying short-oil alkyd resin, cobaltous oxide nanoparticles and acrylpimaric acid (ethylenediamine) amide, a solvent composed of a mixture of p-xylene and butyl acetate in a volume ratio of 5:2, talcum powder, bentonite, a dispersant polyethylene glycol 200, a leveling agent polyether-modified polydimethylsiloxane copolymer and a drying agent ferric cyclopentaneate, and high-speed stirring to obtain a high-performance alkyd resin anticorrosive varnish, which has a high pitting potential and good pitting corrosion resistance, but does not have good fire resistance and has a limited scope of application. Chinese patent CN106978073B discloses an acrylate-modified rosin-based alkyd resin anticorrosive coating and its preparation method, wherein the coating is mixed with acrylate-modified rosin-based alkyd resin, 100# solvent oil, xylene, barium sulfate, titanium dioxide, talcum powder and additives. The anticorrosive coating prepared by this invention has the characteristics of good impact strength, weather resistance, salt resistance and fog resistance; but the xylene added in this invention has obvious VOC problems. VOC will have a negative impact on the environment and human health, and is not conducive to safety issues, and needs to be further strengthened. Summary of the invention

[0004] In order to solve the above technical problems, the present invention provides a high-flash-point safe alkyd anti-corrosion coating, which solves the problem that the flash point of the alkyd anti-corrosion coating in the prior art is low and the safety needs to be further improved.

[0005] In order to achieve the above object, the present invention provides a method for preparing a high flash point safe alkyd anticorrosive coating, comprising the following steps:

[0006] Step (1) uniformly mixing N,N-dimethylformamide, hydroxylated graphene oxide, decenyl succinic anhydride, 4-dimethylaminopyridine and sodium hydroxide, heating, reacting, filtering, washing and drying after the reaction is completed to obtain modified graphene oxide;

[0007] Step (2) mixing the modified graphene oxide, epoxy resin, triethylamine and N,N-dimethylformamide, heating, reacting, and rotary evaporating after the reaction is completed to obtain the modified graphene oxide grafted epoxy resin;

[0008] Step (3) in an inert gas atmosphere, linoleic acid, modified graphene oxide grafted epoxy resin, phenyl phosphate, a catalyst and a solvent are mixed, the temperature is increased and stirred; the temperature is continued to be increased and kept warm; the temperature is decreased and the solvent is extracted; and the temperature is cooled to obtain an alkyd prepolymer;

[0009] Step (4) heating the alkyd prepolymer, adding acrylic acid, methyl methacrylate, and an initiator, reacting, and after the reaction is completed, adding N,N-dimethylethanolamine, deionized water, and an emulsifier, stirring at high speed, and cooling to obtain a modified alkyd resin emulsion;

[0010] Step (5) mixing the modified alkyd resin emulsion, the high flash point solvent, titanium dioxide, the light stabilizer, the antioxidant, the leveling agent and the defoamer, and stirring evenly to obtain component A;

[0011] The curing agent of component A and component B is mixed according to a certain proportion to obtain a high flash point safe alkyd anticorrosive coating.

[0012] Preferably, the method for preparing hydroxylated graphene oxide comprises the following steps:

[0013] A was prepared by adding graphene oxide to deionized water, adding calcium chloride, and adding disodium ethylenediaminetetraacetate;

[0014] Disodium ethylenediaminetetraacetate was dissolved in disodium hydrogen phosphate solution to prepare B;

[0015] Add B to A and add anhydrous ethylenediamine to adjust the pH to 7-9, stir, age, and wash to obtain hydroxylated graphene oxide;

[0016] Wherein, the mass ratio of graphene oxide to calcium chloride is (10-80):1;

[0017] Wherein, the mass ratio of disodium ethylenediaminetetraacetate to calcium chloride in solution A is (0.4-1.8):1.

[0018] Preferably, the mass ratio of N,N-dimethylformamide, hydroxylated graphene oxide, decenyl succinic anhydride, 4-dimethylaminopyridine and sodium hydroxide is (2500-4500):(60-80):(100-120):(4-6):(1-2); the reaction temperature is 80-90°C, and the reaction time is 6-10h.

[0019] Preferably, the mass ratio of modified graphene oxide, epoxy resin, triethylamine and N,N-dimethylformamide is (20-40):(60-80):(1-3):(300-500); the reaction temperature is 100-120° C., and the reaction time is 2-4 h.

[0020] Preferably, the catalyst is dibutyltin dilaurate.

[0021] Preferably, the mass ratio of linoleic acid, modified graphene oxide grafted epoxy resin, phenyl phosphate, catalyst and solvent is (280-340):(65-75):(12-20):(0.4-0.8):(70-80).

[0022] Preferably, the solvent is an alcohol ether solvent.

[0023] Preferably, the alcohol ether solvent is any one of propylene glycol methyl ether and ethylene glycol butyl ether.

[0024] Preferably, the mass ratio of alkyd prepolymer, acrylic acid, methyl methacrylate, initiator, N,N-dimethylethanolamine, deionized water and emulsifier is (60-80):(10-20):(15-25):(1-3):(5-10):(80-120):(2-5).

[0025] Preferably, the mass ratio of modified alkyd resin emulsion, high flash point solvent, titanium dioxide, light stabilizer, antioxidant, leveling agent and defoamer is (50-70):(15-25):(10-20):(1-3):(1-3):(0.5-1.5):(0.5-1.5).

[0026] Preferably, the B component curing agent is an amine curing agent.

[0027] Preferably, the mass ratio of component A to component B is (4-6):1.

[0028] Preferably, the high flash point solvent is any one of 3-methoxybutyl acetate and butyl lactate.

[0029] Preferably, the epoxy resin is one or more of E-44 epoxy resin and E-51 epoxy resin.

[0030] Preferably, the titanium dioxide has a micron structure.

[0031] Preferably, the initiator is ammonium sulfate.

[0032] Preferably, the emulsifier is sodium dodecylbenzene sulfonate.

[0033] Preferably, the light stabilizer is any one of UV-326 and UV-327.

[0034] Preferably, the antioxidant is any one of the antioxidant 1010 and the antioxidant 264 .

[0035] Preferably, the defoamer is BYK-024.

[0036] Preferably, the leveling agent is polydimethylsiloxane.

[0037] Preferably, in step (3), the first heating temperature is 130-140°C; the second heating temperature is 215-225°C, and the insulation time is 2-3h; the first cooling temperature is 165-185°C; and the cooling temperature is 65-75°C.

[0038] Preferably, the reaction temperature in step (4) is 130-140° C., and the reaction time is 3-4 h.

[0039] Preferably, a high flash point safe alkyd anti-corrosion coating is prepared by the preparation method of the high flash point safe alkyd anti-corrosion coating.

[0040] Compared with the prior art, the present invention has the following beneficial effects:

[0041] 1. In the present invention, graphene oxide is a nanostructured layered material. Adding it to a matrix material will improve the mechanical properties to a certain extent, and the hydroxylated graphene oxide obtained after treatment has better compatibility; the hydroxyl group in the hydroxylated graphene oxide reacts with the anhydride group in the decenyl succinic anhydride to obtain a modified graphene oxide containing an ester group, a carboxyl group and a carbon-carbon unsaturated bond; at the same time, the modified graphene oxide also has a long chain structure, which improves the hydrophobicity of the coating by increasing the hydrophobic area, is beneficial to water resistance and corrosion resistance, and can also improve a certain degree of flexibility, is beneficial to the impact resistance of the coating material, and reduces the probability of cracking of the coating. The carboxyl group in the modified graphene oxide has good reactivity, and can react with the epoxy group in the epoxy resin to open the ring, further increase the dispersibility of the graphene oxide, and embed it into the chain, reduce the probability of its falling off, and is beneficial to stability. The hydroxyl groups in the modified graphene oxide grafted epoxy resin and the hydroxyl groups in phenyl phosphate can react with the carboxyl groups in linoleic acid under the action of a catalyst to undergo dehydration and esterification, resulting in a higher degree of crosslinking, thereby increasing the final crosslinking density and water resistance of the paint film, and the density of the formed coating is improved, which is beneficial to the anti-corrosion performance; at this time, the unsaturated bonds contained in the alkyd prepolymer can react with acrylic acid and methyl methacrylate under the action of an initiator, and this reaction increases the number of unsaturated bonds in the modified alkyd resin, thereby increasing the degree of oxidative crosslinking of the coating, which is beneficial to improving the drying speed of the water-based alkyd coating.

[0042] 2. After the epoxy resin introduced in the present invention is modified, the epoxy resin can improve the water resistance of the coating, increase the adhesion to the substrate, and help prevent moisture penetration. Acrylate polymers have good hydrophobicity and water resistance, and can adapt to a variety of coating requirements. Linolenic acid can provide fatty acid segments, which are an important component of alkyd resins, giving the resin flexibility and certain water resistance. Its long-chain structure helps to improve the flexibility of the coating after film formation and the adhesion to the substrate. In addition, the graphene oxide added in the present invention can be used as a filler in the coating, extending the way for water, oxygen and ions in the outside to enter the surface of the base layer, delaying the corrosion time, and being beneficial to corrosion resistance; phenyl phosphate contains phosphorus elements, which generate phosphorus-containing free radicals under high-temperature combustion conditions, and a free radical quenching effect occurs in the matrix, thereby slowing down the combustion reaction, achieving the purpose of flame retardancy, and can further cooperate with graphene oxide to achieve the purpose of fire prevention. Phenyl phosphate contains a benzene ring structure and has a certain rigidity. Its addition to the coating will increase the hardness of the coating material, increase impact resistance and heat resistance. The titanium dioxide introduced in the present invention has a micron structure, and can form a micro-nano structure with nanoparticles. These micro-nano structures form an air layer on the surface, which prevents corrosive media from entering the metal surface and has a self-cleaning effect, which is beneficial to prolonging the service life and anti-corrosion performance. The butyl lactate in the present invention can increase the flexibility and impact resistance of the coating film, which helps the coating film not to crack easily, and butyl lactate can form a strong adhesion between the coating and the metal substrate, enhance the bonding force between the coating and the metal base surface, and is beneficial to the anti-corrosion performance; in addition, butyl lactate is beneficial to prevent moisture, oxygen and other corrosive factors from penetrating into the metal base surface, thereby prolonging the anti-corrosion protection time.

[0043] 3. The high flash point safe alkyd anticorrosive coating provided by the present invention does not contain harmful substances such as heavy metals, and has a low content of volatile organic matter, is not easy to burn, and can effectively avoid the problem of decreased fire retardant performance of the coating caused by incomplete solvent volatilization. And the high flash point solvents introduced in the present invention usually have a higher flash point, which means that they will only burn or produce flammable vapors at a relatively high temperature, making the coating difficult to ignite during storage, transportation and use, thereby improving the fire safety of the coating to a certain extent. At the same time, the present invention uses a modified alkyd resin emulsion to replace part of the organic solvent, and the VOC content of the product is reduced, which meets the safety standards. The modified alkyd resin emulsion is a non-flammable liquid, which can make water a limited diluent to replace the organic solvent while improving the flash point of the product, thereby improving the safety of the product. BRIEF DESCRIPTION OF THE DRAWINGS

[0044] Figure 1 The present invention is a process flow chart for preparing a high flash point safe alkyd anticorrosive coating;

[0045] Figure 2 The present invention is a process flow chart for preparing the modified alkyd resin emulsion;

[0046] Figure 3 This is a bar graph showing the corrosion resistance test of the high flash point safe alkyd anticorrosive coatings prepared in Examples 1-5 and Comparative Examples 1-3 of the present invention. DETAILED DESCRIPTION

[0047] The technical solution of the present invention will be clearly and completely described below in conjunction with the embodiments. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than 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.

[0048] Example 1

[0049] This embodiment provides a method for preparing a high flash point safe alkyd anticorrosive coating, comprising the following steps:

[0050] Step (1) N,N-dimethylformamide, hydroxylated graphene oxide, decenyl succinic anhydride, 4-dimethylaminopyridine and sodium hydroxide in a mass ratio of 2500:60:100:4:1 are mixed uniformly, reacted at 80° C. for 10 h, filtered, washed with anhydrous ethanol, and dried at 80° C. for 6 h to obtain modified graphene oxide;

[0051] Step (2) Mixing modified graphene oxide, E-44 epoxy resin, triethylamine and N,N-dimethylformamide in a mass ratio of 20:60:1:300, reacting at 100° C. for 4 h, and performing rotary evaporation to obtain modified graphene oxide grafted epoxy resin;

[0052] Step (3) In an Ar atmosphere, linoleic acid, modified graphene oxide grafted epoxy resin, phenyl phosphate, dibutyltin dilaurate and ethylene glycol butyl ether in a mass ratio of 280:65:12:0.4:70 are mixed and stirred evenly at a temperature of 130° C.; the temperature is continued to be raised to 215° C. and kept warm for 3 h; the temperature is lowered to 165° C., the solvent is extracted for 2 h, and the temperature is cooled to 65° C. to obtain an alkyd prepolymer;

[0053] Step (4) heating the alkyd prepolymer to 130° C., adding acrylic acid, methyl methacrylate, and initiator ammonium sulfate, reacting at 130° C. for 4 hours, and after the reaction is completed, adding N,N-dimethylethanolamine, deionized water, and sodium dodecylbenzene sulfonate, stirring at a speed of 20,000 r / min for 18 minutes, and cooling to room temperature to obtain a modified alkyd resin emulsion;

[0054] The mass ratio of alkyd prepolymer, acrylic acid, methyl methacrylate, initiator ammonium sulfate, N,N-dimethylethanolamine, deionized water and sodium dodecylbenzene sulfonate is 60:10:15:1:5:80:2;

[0055] Step (5) Mix the modified alkyd resin emulsion, butyl lactate, titanium dioxide, UV-326, antioxidant 1010, polydimethylsiloxane and BYK-024, and stir evenly to obtain component A;

[0056] The component A and the curing agent triethylamine of the component B are mixed in a mass ratio of 4:1 to obtain a high flash point safe alkyd anticorrosive coating;

[0057] Among them, the mass ratio of modified alkyd resin emulsion, butyl lactate, titanium dioxide, UV-326, antioxidant 1010, polydimethylsiloxane and BYK-024 is 50:15:10:1:1:0.5:0.5.

[0058] Example 2

[0059] This embodiment provides a method for preparing a high flash point safe alkyd anticorrosive coating, comprising the following steps:

[0060] Step (1) N,N-dimethylformamide, hydroxylated graphene oxide, decenyl succinic anhydride, 4-dimethylaminopyridine and sodium hydroxide in a mass ratio of 3000:65:105:4.5:1.2 are mixed uniformly, reacted at 82° C. for 9 h, filtered, washed with anhydrous ethanol, and dried at 85° C. for 5.5 h to obtain modified graphene oxide;

[0061] Step (2) Mixing modified graphene oxide, E-44 epoxy resin, triethylamine and N,N-dimethylformamide in a mass ratio of 25:65:1.5:350, reacting at 105° C. for 3.5 hours, and rotary evaporating to obtain modified graphene oxide grafted epoxy resin;

[0062] Step (3) In an Ar atmosphere, linoleic acid, modified graphene oxide grafted epoxy resin, phenyl phosphate, dibutyltin dilaurate and ethylene glycol butyl ether in a mass ratio of 295:67:14:0.5:72 are mixed and stirred evenly at a temperature of 132° C.; the temperature is continued to be raised to 217° C. and kept warm for 2.8 hours; the temperature is lowered to 170° C., the solvent is extracted for 1.8 hours, and the temperature is cooled to 67° C. to obtain an alkyd prepolymer;

[0063] Step (4) heating the alkyd prepolymer to 132° C., adding acrylic acid, methyl methacrylate, and initiator ammonium sulfate, reacting at 132° C. for 3.8 hours, and after the reaction is completed, adding N,N-dimethylethanolamine, deionized water, and sodium dodecylbenzene sulfonate, stirring at a speed of 22500 r / min for 16 minutes, and cooling to room temperature to obtain a modified alkyd resin emulsion;

[0064] The mass ratio of alkyd prepolymer, acrylic acid, methyl methacrylate, initiator ammonium sulfate, N,N-dimethylethanolamine, deionized water and sodium dodecylbenzene sulfonate is 65:12:17:1.5:6:90:2.7;

[0065] Step (5) Mix the modified alkyd resin emulsion, butyl lactate, titanium dioxide, UV-326, antioxidant 1010, polydimethylsiloxane and BYK-024, and stir evenly to obtain component A;

[0066] The component A and the curing agent triethylamine of the component B are mixed in a mass ratio of 4.5:1 to obtain a high flash point safe alkyd anticorrosive coating;

[0067] Among them, the mass ratio of modified alkyd resin emulsion, butyl lactate, titanium dioxide, UV-326, antioxidant 1010, polydimethylsiloxane and BYK-024 is 55:17:12:1.5:1.5:0.75:0.75.

[0068] Example 3

[0069] This embodiment provides a method for preparing a high flash point safe alkyd anticorrosive coating, comprising the following steps:

[0070] Step (1) N,N-dimethylformamide, hydroxylated graphene oxide, decenyl succinic anhydride, 4-dimethylaminopyridine and sodium hydroxide in a mass ratio of 3500:70:110:5:1.5 are mixed uniformly, reacted at 85° C. for 8 h, filtered, washed with anhydrous ethanol, and dried at 90° C. for 5 h to obtain modified graphene oxide;

[0071] Step (2) Mixing modified graphene oxide, E-44 epoxy resin, triethylamine and N,N-dimethylformamide in a mass ratio of 30:70:2:400, reacting at a temperature of 110° C. for 3 hours, and rotary evaporating to obtain modified graphene oxide grafted epoxy resin;

[0072] Step (3) In an Ar atmosphere, linoleic acid, modified graphene oxide grafted epoxy resin, phenyl phosphate, dibutyltin dilaurate and ethylene glycol butyl ether in a mass ratio of 310:70:16:0.6:75 are mixed and stirred evenly at a temperature of 135° C.; the temperature is continued to be raised to 220° C. and kept warm for 2.5 hours; the temperature is lowered to 175° C., the solvent is extracted for 1.5 hours, and the temperature is cooled to 70° C. to obtain an alkyd prepolymer;

[0073] Step (4) heating the alkyd prepolymer to 135° C., adding acrylic acid, methyl methacrylate, and initiator ammonium sulfate, reacting at 135° C. for 3.5 hours, and after the reaction is completed, adding N,N-dimethylethanolamine, deionized water, and sodium dodecylbenzene sulfonate, stirring at a speed of 25,000 r / min for 14 minutes, and cooling to room temperature to obtain a modified alkyd resin emulsion;

[0074] The mass ratio of alkyd prepolymer, acrylic acid, methyl methacrylate, initiator ammonium sulfate, N,N-dimethylethanolamine, deionized water and sodium dodecylbenzene sulfonate is 70:15:20:2:8:100:3.5;

[0075] Step (5) Mix the modified alkyd resin emulsion, butyl lactate, titanium dioxide, UV-326, antioxidant 1010, polydimethylsiloxane and BYK-024, and stir evenly to obtain component A;

[0076] The component A and the curing agent triethylamine of the component B are mixed in a mass ratio of 5:1 to obtain a high flash point safe alkyd anticorrosive coating;

[0077] Among them, the mass ratio of modified alkyd resin emulsion, butyl lactate, titanium dioxide, UV-326, antioxidant 1010, polydimethylsiloxane and BYK-024 is 60:20:15:2:2:1:1.

[0078] Example 4

[0079] This embodiment provides a method for preparing a high flash point safe alkyd anticorrosive coating, comprising the following steps:

[0080] Step (1) N,N-dimethylformamide, hydroxylated graphene oxide, decenyl succinic anhydride, 4-dimethylaminopyridine and sodium hydroxide in a mass ratio of 4000:75:115:5.5:1.7 are mixed uniformly, reacted at 87° C. for 7 h, filtered, washed with anhydrous ethanol, and dried at 95° C. for 4.5 h to obtain modified graphene oxide;

[0081] Step (2) Mixing modified graphene oxide, E-44 epoxy resin, triethylamine and N,N-dimethylformamide in a mass ratio of 35:75:2.5:450, reacting at a temperature of 115° C. for 2.5 hours, and rotary evaporating to obtain modified graphene oxide grafted epoxy resin;

[0082] Step (3) In an Ar atmosphere, linoleic acid, modified graphene oxide grafted epoxy resin, phenyl phosphate, dibutyltin dilaurate and ethylene glycol butyl ether in a mass ratio of 325:72:18:0.7:77 are mixed and stirred evenly at a temperature of 137° C.; the temperature is continued to be raised to 222° C. and kept warm for 2.3 h; the temperature is lowered to 180° C., the solvent is extracted for 1.2 h, and the temperature is cooled to 72° C. to obtain an alkyd prepolymer;

[0083] Step (4) heating the alkyd prepolymer to 137° C., adding acrylic acid, methyl methacrylate, and initiator ammonium sulfate, reacting at 137° C. for 3.2 hours, and after the reaction is completed, adding N,N-dimethylethanolamine, deionized water, and sodium dodecylbenzene sulfonate, stirring at a speed of 27500 r / min for 12 minutes, and cooling to room temperature to obtain a modified alkyd resin emulsion;

[0084] The mass ratio of alkyd prepolymer, acrylic acid, methyl methacrylate, initiator ammonium sulfate, N,N-dimethylethanolamine, deionized water and sodium dodecylbenzene sulfonate is 75:17:22:2.5:9:110:4.2;

[0085] Step (5) Mix the modified alkyd resin emulsion, butyl lactate, titanium dioxide, UV-326, antioxidant 1010, polydimethylsiloxane and BYK-024, and stir evenly to obtain component A;

[0086] The component A and the curing agent triethylamine of the component B are mixed in a mass ratio of 5.5:1 to obtain a high flash point safe alkyd anticorrosive coating;

[0087] Among them, the mass ratio of modified alkyd resin emulsion, butyl lactate, titanium dioxide, UV-326, antioxidant 1010, polydimethylsiloxane and BYK-024 is 65:22:17:2.5:2.5:1.3:1.3.

[0088] Example 5

[0089] This embodiment provides a method for preparing a high flash point safe alkyd anticorrosive coating, comprising the following steps:

[0090] Step (1) N,N-dimethylformamide, hydroxylated graphene oxide, decenyl succinic anhydride, 4-dimethylaminopyridine and sodium hydroxide in a mass ratio of 4500:80:120:6:2 are mixed uniformly, reacted at 90° C. for 6 h, filtered, washed with anhydrous ethanol, and dried at 100° C. for 4 h to obtain modified graphene oxide;

[0091] Step (2) Mixing modified graphene oxide, E-44 epoxy resin, triethylamine and N,N-dimethylformamide in a mass ratio of 40:80:3:500, reacting at 120° C. for 2 h, and rotary evaporating to obtain modified graphene oxide grafted epoxy resin;

[0092] Step (3) In an Ar atmosphere, linoleic acid, modified graphene oxide grafted epoxy resin, phenyl phosphate, dibutyltin dilaurate and ethylene glycol butyl ether in a mass ratio of 340:75:20:0.8:80 are mixed and stirred evenly at a temperature of 140° C.; the temperature is continued to be raised to 225° C. and kept warm for 2 h; the temperature is lowered to 185° C., the solvent is extracted for 1 h, and the temperature is cooled to 75° C. to obtain an alkyd prepolymer;

[0093] Step (4) heating the alkyd prepolymer to 140° C., adding acrylic acid, methyl methacrylate, and initiator ammonium sulfate, reacting at 140° C. for 3 h, adding N,N-dimethylethanolamine, deionized water, and sodium dodecylbenzene sulfonate, stirring at a speed of 30,000 r / min for 10 min, and cooling to room temperature to obtain a modified alkyd resin emulsion;

[0094] The mass ratio of alkyd prepolymer, acrylic acid, methyl methacrylate, initiator ammonium sulfate, N,N-dimethylethanolamine, deionized water and sodium dodecylbenzene sulfonate is 80:20:25:3:10:120:5;

[0095] Step (5) Mix the modified alkyd resin emulsion, butyl lactate, titanium dioxide, UV-326, antioxidant 1010, polydimethylsiloxane and BYK-024, and stir evenly to obtain component A;

[0096] The component A and the curing agent triethylamine of the component B are mixed in a mass ratio of 6:1 to obtain a high flash point safe alkyd anticorrosive coating;

[0097] Among them, the mass ratio of modified alkyd resin emulsion, butyl lactate, titanium dioxide, UV-326, antioxidant 1010, polydimethylsiloxane and BYK-024 is 70:25:20:3:3:1.5:1.5.

[0098] Example 6

[0099] This embodiment provides a method for preparing hydroxylated graphene oxide, comprising the following steps:

[0100] A was prepared by adding graphene oxide to deionized water, adding calcium chloride, and adding disodium ethylenediaminetetraacetate;

[0101] Wherein, the mass ratio of graphene oxide, deionized water, calcium chloride and disodium ethylenediaminetetraacetate is 10:800:1:1.2;

[0102] Disodium ethylenediaminetetraacetate and 0.01 mol / L disodium hydrogen phosphate solution were mixed in a mass ratio of 1:20, and stirred evenly to obtain B;

[0103] At 50°C, B was added to A and anhydrous ethylenediamine was added to adjust the pH to 8.5. The mixture was stirred at 30 r / min for 8 min, aged at room temperature for 12 h, and washed with deionized water three times to obtain hydroxylated graphene oxide.

[0104] Comparative Example 1

[0105] This comparative example provides a method for preparing a high flash point safe alkyd anticorrosive coating, comprising the following steps:

[0106] Step (1) N,N-dimethylformamide, hydroxylated graphene oxide, decenyl succinic anhydride, 4-dimethylaminopyridine and sodium hydroxide in a mass ratio of 2500:60:100:4:1 are mixed uniformly, reacted at 80° C. for 10 h, filtered, washed with anhydrous ethanol, and dried at 80° C. for 6 h to obtain modified graphene oxide;

[0107] Step (2) Mixing modified graphene oxide, E-44 epoxy resin, triethylamine and N,N-dimethylformamide in a mass ratio of 20:60:1:300, reacting at 100° C. for 4 h, and performing rotary evaporation to obtain modified graphene oxide grafted epoxy resin;

[0108] Step (3) In an Ar atmosphere, linoleic acid, modified graphene oxide grafted epoxy resin, phenyl phosphate, dibutyltin dilaurate and ethylene glycol butyl ether in a mass ratio of 280:65:12:0.4:70 are mixed and stirred evenly at a temperature of 130° C.; the temperature is continued to be raised to 215° C. and kept warm for 3 h; the temperature is lowered to 165° C., the solvent is extracted for 2 h, and the temperature is cooled to 65° C. to obtain an alkyd resin;

[0109] Step (4) alkyd resin, butyl lactate, titanium dioxide, UV-326, antioxidant 1010, polydimethylsiloxane and BYK-024 are mixed and stirred to obtain component A;

[0110] The component A and the curing agent triethylamine of the component B are mixed in a mass ratio of 4:1 to obtain a high flash point safe alkyd anticorrosive coating;

[0111] Among them, the mass ratio of alkyd resin, butyl lactate, titanium dioxide, UV-326, antioxidant 1010, polydimethylsiloxane and BYK-024 is 50:15:10:1:1:0.5:0.5.

[0112] Comparative Example 2

[0113] This comparative example provides a method for preparing a high flash point safe alkyd anticorrosive coating, comprising the following steps:

[0114] Step (1) N,N-dimethylformamide, hydroxylated graphene oxide, decenyl succinic anhydride, 4-dimethylaminopyridine and sodium hydroxide in a mass ratio of 2500:60:100:4:1 are mixed uniformly, reacted at 80° C. for 10 h, filtered, washed with anhydrous ethanol, and dried at 80° C. for 6 h to obtain modified graphene oxide;

[0115] Step (2) Mixing modified graphene oxide, E-44 epoxy resin, triethylamine and N,N-dimethylformamide in a mass ratio of 20:60:1:300, reacting at 100° C. for 4 h, and performing rotary evaporation to obtain modified graphene oxide grafted epoxy resin;

[0116] Step (3) In an Ar atmosphere, linoleic acid, modified graphene oxide grafted epoxy resin, dibutyltin dilaurate and ethylene glycol butyl ether in a mass ratio of 292:65:0.4:70 are mixed and stirred evenly at a temperature of 130° C.; the temperature is continued to be raised to 215° C. and kept warm for 3 h; the temperature is lowered to 165° C., the solvent is extracted for 2 h, and the temperature is cooled to 65° C. to obtain an alkyd resin;

[0117] Step (4) alkyd resin, butyl lactate, titanium dioxide, UV-326, antioxidant 1010, polydimethylsiloxane and BYK-024 are mixed and stirred to obtain component A;

[0118] The component A and the curing agent triethylamine of the component B are mixed in a mass ratio of 4:1 to obtain a high flash point safe alkyd anticorrosive coating;

[0119] Among them, the mass ratio of alkyd resin, butyl lactate, titanium dioxide, UV-326, antioxidant 1010, polydimethylsiloxane and BYK-024 is 50:15:10:1:1:0.5:0.5.

[0120] Comparative Example 3

[0121] This comparative example provides a method for preparing a high flash point safe alkyd anticorrosive coating, comprising the following steps:

[0122] Step (1) N,N-dimethylformamide, hydroxylated graphene oxide, decenyl succinic anhydride, 4-dimethylaminopyridine and sodium hydroxide in a mass ratio of 2500:60:100:4:1 are mixed uniformly, reacted at 80° C. for 10 h, filtered, washed with anhydrous ethanol, and dried at 80° C. for 6 h to obtain modified graphene oxide;

[0123] Step (2) Mixing modified graphene oxide, E-44 epoxy resin, triethylamine and N,N-dimethylformamide in a mass ratio of 20:60:1:300, reacting at 100° C. for 4 h, and performing rotary evaporation to obtain modified graphene oxide grafted epoxy resin;

[0124] Step (3) In an Ar atmosphere, linoleic acid, modified graphene oxide grafted epoxy resin, dibutyltin dilaurate and ethylene glycol butyl ether in a mass ratio of 292:65:0.4:70 are mixed and stirred evenly at a temperature of 130° C.; the temperature is continued to be raised to 215° C. and kept warm for 3 h; the temperature is lowered to 165° C., the solvent is extracted for 2 h, and the temperature is cooled to 65° C. to obtain an alkyd resin;

[0125] Step (4) mixing alkyd resin, titanium dioxide, UV-326, antioxidant 1010, polydimethylsiloxane and BYK-024, stirring evenly to obtain component A;

[0126] The component A and the curing agent triethylamine of the component B are mixed in a mass ratio of 4:1 to obtain a high flash point safe alkyd anticorrosive coating;

[0127] Among them, the mass ratio of alkyd resin, titanium dioxide, UV-326, antioxidant 1010, polydimethylsiloxane and BYK-024 is 65:10:1:1:0.5:0.5.

[0128] The hydroxylated graphene oxide in the examples of the present invention and the comparative examples both adopt the hydroxylated graphene oxide prepared in Example 6.

[0129] In the embodiments and comparative examples of the present invention, graphene oxide comes from Beijing Huawei Ruike Chemical Co., Ltd., and the graphene oxide is a single-layer graphene oxide with an average thickness of 0.8-1.2 nm and a diameter of 0.5-5 μm; E-44 epoxy resin comes from Langfang Senqiang Environmental Protection Technology Co., Ltd.; decenyl succinic anhydride comes from Shandong Yaotong Industrial Co., Ltd., CAS No.: 25447-83-0; titanium dioxide is preferably DuPont R706, with an average particle size of 0.26 μm; BYK-024 comes from BYK Company of Germany.

[0130] Corresponding tests were performed on the high flash point safe alkyd anticorrosive coatings prepared in Examples 1-5 and Comparative Examples 1-3. The test results are as follows:

[0131] (1) Flash point test: The flash point was tested according to standard GB / T 261-2008. The specific test results are shown in Table 1.

[0132] (2) Non-volatile content test: The non-volatile content was tested according to GB / T 1725-2007. The specific test results are shown in Table 1.

[0133] (3) Drying performance test: The surface drying time was measured according to the surface drying method B of GB / T 1728-1979; the actual drying time was measured according to the actual drying method A of GB / T1728-1979. The specific test results are shown in Table 1.

[0134] Table 1

[0135]

[0136] According to the test results in Table 1, it can be seen that the high flash point safe alkyd anticorrosive coatings prepared in Examples 1-5 not only have high flash points and low volatile content, but also have good drying properties. In Example 1, because of the modification of acrylic acid and methyl methacrylate, the double bond consumption of the fatty acid segment during the grafting modification process is reduced, and the fatty acid segment in linoleic acid has more double bonds to undergo oxidative crosslinking reactions during curing and crosslinking, the density of the paint film is increased, and the surface drying rate is improved. Once it is missing, the drying performance is reduced, so the drying performance of Comparative Example 1 is lower than that of Example 1; Comparative Example 2 lacks phenyl phosphate compared to Comparative Example 1, and phenyl phosphate contains 2 hydroxyl groups, which can participate in the reaction and directly embed into the chain of the alkyd resin, increasing the crosslinking. Once it is missing, the density is reduced, which is not conducive to the surface drying performance, so the surface drying performance of Comparative Example 1 is better than that of Comparative Example 2; Comparative Example 3 lacks the high flash point solvent butyl lactate compared to Comparative Example 2, which is not conducive to the coating forming a more uniform, continuous and smooth coating film during the drying process, affecting the surface drying effect, so the drying performance of Comparative Example 2 is better than that of Comparative Example 3.

[0137] The high flash point safe alkyd anticorrosive coating prepared in Examples 1-5 and Comparative Examples 1-3 was roller-coated on the surface of the galvanized steel sheet with surface treatment to prepare a coating. After curing at 30° C. for 18 hours, the thickness of the coating on the surface of the galvanized steel sheet after curing was 30 μm. The galvanized steel sheet with a high flash point safe alkyd anticorrosive coating was obtained and subjected to a corrosion resistance test:

[0138] The galvanized steel plates with the above-mentioned high flash point safe alkyd anticorrosive coating were immersed in 3% sodium oxide solution, the samples were suspended with plastic ropes, the upper end was more than 2 cm from the liquid surface, the pH value of the solution was 6, the salt water was changed every six days, and the samples were left open at a temperature of 10 ± 2 ° C. The time when the first red rust appeared on each sample was recorded, and the corrosion resistance time was used as the corrosion resistance evaluation result. The results are shown in Table 2;

[0139] Table 2

[0140]

[0141] As shown in Table 2, the high flash point safe alkyd anticorrosive coating prepared by the present invention has good corrosion resistance, and the anticorrosion effect of Example 1 is the best. Compared with Example 1, there is no addition of acrylic acid and methyl methacrylate in Comparative Example 1, which is not conducive to improving the film-forming property of the resin and forming a more continuous and dense coating, thereby affecting the barrier of the corrosive medium from penetrating into the surface of the substrate, while the acrylic acid ester substance itself has good chemical stability and can improve the resistance of the entire system to chemical substances. Once it is lacking, the corrosion resistance is reduced, so the corrosion resistance of Comparative Example 1 is lower than that of Example 1; Comparative Example 2 lacks phenyl phosphate compared with Comparative Example 1, and the density of the formed coating is reduced, which is not conducive to the anticorrosion performance; Comparative Example 3 lacks butyl lactate compared with Comparative Example 2, so the flexibility and impact resistance of the coating are reduced, the probability of cracking of the coating is greater than that of Comparative Example 2, and the adhesion between the coating and the metal substrate is not as good as that of Comparative Example 2, and the time to prevent moisture, oxygen and other corrosive factors from penetrating into the metal surface is shortened, which is not conducive to anticorrosion, so the corrosion resistance of Comparative Example 2 is worse than that of Comparative Example 3.

[0142] Although the embodiments of the present invention have been shown and described, it will be understood 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 all equivalent changes and improvements made within the scope of the present invention should still fall within the scope of the patent coverage of the present invention.

Claims

1. A method for preparing a high flash point safe alkyd anticorrosive coating, characterized in that: The following steps are involved: Step (1) uniformly mixing N,N-dimethylformamide, hydroxylated graphene oxide, decenyl succinic anhydride, 4-dimethylaminopyridine and sodium hydroxide, heating, reacting, filtering, washing and drying after the reaction is completed to obtain modified graphene oxide; Step (2) mixing the modified graphene oxide, epoxy resin, triethylamine and N,N-dimethylformamide, heating, reacting, and rotary evaporating after the reaction is completed to obtain the modified graphene oxide grafted epoxy resin; Step (3) in an inert gas atmosphere, linoleic acid, modified graphene oxide grafted epoxy resin, phenyl phosphate, a catalyst and a solvent are mixed, the temperature is increased and stirred; the temperature is continued to be increased and kept warm; the temperature is decreased and the solvent is extracted; and the temperature is cooled to obtain an alkyd prepolymer; Step (4) heating the alkyd prepolymer, adding acrylic acid, methyl methacrylate, and an initiator, reacting, and after the reaction is completed, adding N,N-dimethylethanolamine, deionized water, and an emulsifier, stirring at high speed, and cooling to obtain a modified alkyd resin emulsion; Step (5) mixing the modified alkyd resin emulsion, the high flash point solvent, titanium dioxide, the light stabilizer, the antioxidant, the leveling agent and the defoamer, and stirring evenly to obtain component A; The curing agent of component A and component B is mixed according to a certain proportion to obtain a high flash point safe alkyd anticorrosive coating.

2. The method for preparing a high flash point safe alkyd anticorrosive coating according to claim 1, characterized in that: The mass ratio of N,N-dimethylformamide, hydroxylated graphene oxide, decenyl succinic anhydride, 4-dimethylaminopyridine and sodium hydroxide is (2500-4500):(60-80):(100-120):(4-6):(1-2); the reaction temperature is 80-90°C, and the reaction time is 6-10h.

3. The method for preparing a high flash point safe alkyd anticorrosive coating according to claim 1, characterized in that: The mass ratio of modified graphene oxide, epoxy resin, triethylamine and N,N-dimethylformamide is (20-40):(60-80):(1-3):(300-500); the reaction temperature is 100-120° C., and the reaction time is 2-4 hours.

4. The method for preparing a high flash point safe alkyd anticorrosive coating according to claim 1, characterized in that: The catalyst is dibutyltin dilaurate.

5. The method for preparing a high flash point safe alkyd anticorrosive coating according to claim 1, characterized in that: The mass ratio of linoleic acid, modified graphene oxide grafted epoxy resin, phenyl phosphate, catalyst and solvent is (280-340):(65-75):(12-20):(0.4-0.8):(70-80).

6. The method for preparing a high flash point safe alkyd anticorrosive coating according to claim 1, characterized in that: The mass ratio of alkyd prepolymer, acrylic acid, methyl methacrylate, initiator, N,N-dimethylethanolamine, deionized water and emulsifier is (60-80):(10-20):(15-25):(1-3):(5-10):(80-120):(2-5).

7. The method for preparing a high flash point safe alkyd anticorrosive coating according to claim 1, characterized in that: The mass ratio of modified alkyd resin emulsion, high flash point solvent, titanium dioxide, light stabilizer, antioxidant, leveling agent and defoaming agent is (50-70):(15-25):(10-20):(1-3):(1-3):(0.5-1.5):(0.5-1.5).

8. The method for preparing a high flash point safe alkyd anticorrosive coating according to claim 1, characterized in that: The curing agent of component B is an amine curing agent.

9. The method for preparing a high flash point safe alkyd anticorrosive coating according to claim 1, characterized in that: The mass ratio of component A to component B is (4-6):

1.

10. A high flash point safe alkyd anticorrosive coating prepared by the preparation method of the high flash point safe alkyd anticorrosive coating according to any one of claims 1 to 9.

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