Water-based hyperbranched epoxy resin emulsion and preparation method thereof as well as anticorrosive primer and preparation method and application thereof

Abstract

The invention discloses a water-based hyperbranched epoxy resin emulsion and a preparation method thereof as well as an anticorrosive primer and a preparation method and application thereof, and relates to the technical field of anticorrosive paints.The epoxy resin emulsion is a self-emulsified water-based epoxy resin emulsion prepared from raw materials including hyperbranched phenolic modified epoxy resin and an emulsifier aqueous solution; the hyperbranched phenolic aldehyde modified epoxy resin is prepared by taking phenolic aldehyde modified epoxy resin as a branch chain to be grafted to a polyglycerol molecule; the emulsifier aqueous solution is prepared from raw materials including phenolic aldehyde modified epoxy resin, a water-oil amphiphilic substance, an emulsification accelerant, deionized water and a surfactant. The long-acting corrosion-resistant temperature-resistant chromium-free water-based hyperbranched epoxy corrosion-resistant primer system does not contain chromium-containing filler, aluminum powder, zinc powder and the like, the current green and environment-friendly requirements can be met, and meanwhile, a prepared paint film is high in hardness, high in strength and good in shielding property and has excellent long-acting corrosion-resistant and temperature-resistant effects.

Description

Technical Field

[0001] The present invention relates to the technical field of anti-corrosion coatings, and more particularly to a water-based hyperbranched epoxy resin emulsion and a preparation method thereof, and an anti-corrosion primer and a preparation method and application thereof. Background Art

[0002] Epoxy resins are widely used in anti-corrosion coatings due to their high strength and excellent chemical and environmental resistance. Currently, solvent-based epoxy coatings offer sufficient anti-corrosion performance in most situations. However, due to environmental regulations, solvent-based products are no longer suitable for some applications. Consequently, solvent-free and water-based epoxy coatings have emerged as alternatives. However, solvent-free epoxy coatings have high viscosity and require high-quality application equipment, making them inconvenient to use in some applications. Water-based epoxy coatings, on the other hand, offer the advantages of low VOCs, safety, and environmental friendliness.

[0003] Currently, commonly used water-based epoxy coatings are generally divided into two categories: chromium-containing water-based epoxy coatings and zinc-rich water-based epoxy coatings. Hexavalent chromium is widely used due to its excellent corrosion protection properties. However, it is inherently highly toxic, and due to increasingly stringent environmental regulations, its use is increasingly restricted. Water-based anti-corrosion primers based on zinc and aluminum powders are also currently popular, but they suffer from long drying times, poor storage stability, high costs, and limited chemical resistance. Summary of the Invention

[0004] To address the problems existing in the prior art, the present invention provides a water-based hyperbranched epoxy resin emulsion, a method for its preparation, and an anticorrosive primer, as well as a method for its preparation and application. The long-lasting, heat-resistant, chromium-free water-based hyperbranched epoxy anticorrosive primer system of the present invention contains no chromium-containing fillers, aluminum powder, zinc powder, or the like, meeting current environmental protection requirements. The resulting paint film exhibits high hardness, strength, and excellent shielding properties, providing excellent long-lasting corrosion protection and heat resistance.

[0005] One of the objects of the present invention is to provide an aqueous hyperbranched epoxy resin emulsion.

[0006] The water-based hyperbranched epoxy resin emulsion of the present invention is a self-emulsifying water-based epoxy resin emulsion prepared from raw materials including a hyperbranched phenolic modified epoxy resin and an emulsifier aqueous solution;

[0007] The hyperbranched phenolic modified epoxy resin is prepared by grafting phenolic modified epoxy resin as a branch chain onto a polyglycerol molecule;

[0008] The emulsifier aqueous solution is prepared from raw materials including phenolic modified epoxy resin, water-oil amphiphilic substance, emulsification accelerator, deionized water and surfactant.

[0009] In a preferred embodiment of the present invention, the hyperbranched phenolic modified epoxy resin is prepared by the following method:

[0010] Solvent A, polyglycerol and phenolic modified epoxy resin are heated to reflux and kept warm, catalyst A is added and stirred and dispersed, a strong organic acid is added to carry out grafting reaction, and after the reaction is completed, the hyperbranched phenolic modified epoxy resin is prepared by purification, water washing and drying; preferably,

[0011] The molar ratio of the polyglycerol to the phenolic modified epoxy resin is 1:(6-8), more preferably 1:(6.5-7); the phenolic modified epoxy resin is in excess; and / or,

[0012] The solvent A does not participate in the reaction, and technicians can control the amount of addition according to the actual equipment, without specific proportion restrictions; and / or,

[0013] The amount of the catalyst A is 0.3-0.9 wt % of the weight of the phenolic modified epoxy resin, more preferably 0.5-0.8 wt %; and / or,

[0014] The molar ratio of the strong organic acid to the phenolic modified epoxy resin is 1:(1.2-1.5), more preferably 1:(1.2-1.3); and / or,

[0015] The solvent A is benzene; benzene as a solvent and reaction environment has a relatively stable structure, is not prone to side reactions, has no substituents and active groups, and has relatively few by-products; and / or,

[0016] The polyglycerol is a glycerol polycondensate, and more preferably, the degree of polymerization of the polyglycerol is 3 to 5; and / or,

[0017] The catalyst A is triethylamine and / or pyridine; triethylamine and / or pyridine are used as catalysts to promote the reaction. These two catalysts are relatively stable, mild in reaction, and have few by-products. They can open the ring of epoxy groups. After the ring is opened, part of them will react with polyglycerol and be grafted onto the polyglycerol molecular chain to form hydroxyl groups. The remaining part is still in the open state. The added strong organic acid can neutralize the catalyst A and make the opened epoxy groups complete the ring-closing reaction to re-form epoxy groups; and / or,

[0018] The acidity coefficient of the strong organic acid is -3 to 3, and p-toluenesulfonic acid is more preferred. The strong organic acid can be a strong organic acid commonly used in the art, but may cause more side reactions and may result in incomplete reaction due to insufficient acidity. In addition, p-toluenesulfonic acid and its product are well soluble in water and are easy to remove. And / or,

[0019] The reflux temperature is 70-80° C., and the reflux temperature is such that the phenolic modified epoxy resin and other substances are dissolved and dispersed; and / or,

[0020] The stirring and dispersing time is 20 to 30 minutes, and / or the rotation speed is 50 to 100 r / min; and / or,

[0021] The grafting reaction is carried out at a temperature of 70 to 80° C. and / or for a time of 4 to 6 hours.

[0022] The hyperbranched phenolic modified epoxy resin of the present invention has polyglycerol as the main chain and linear phenolic epoxy resin as the side chain. Compared with the currently conventional modified epoxy resin with epoxy resin as the main chain and polyether polyol, polyamine or the like as the side chain, which has large steric hindrance, low epoxy group activity, low rigid group ratio, poor heat resistance and strength, the hyperbranched phenolic modified epoxy resin of the present invention can provide more cross-linking sites and cross-linking activity, has better functionality and molecular rigidity, and the increase in rigid groups also improves its strength and heat resistance. At the same time, it also has relatively good chemical resistance, can react quickly after film formation, and the special branched chain structure can also provide a higher cross-linking degree, increase the density of the paint film, and make the paint film have better shielding properties.

[0023] In a preferred embodiment of the present invention, the emulsifier aqueous solution is prepared by the following method:

[0024] The phenolic modified epoxy resin and the water-oil amphiphilic substance are heated and kept warm, an emulsification accelerator is added dropwise and stirred for reaction, and deionized water and a surfactant are added and stirred and dispersed to obtain the emulsifier aqueous solution; preferably,

[0025] The molar ratio of the phenolic modified epoxy resin to the water-oil amphiphilic substance is 1:(3-7), more preferably 1:(4-5.5); and / or,

[0026] The amount of the emulsification accelerator is 1 to 5 wt % of the weight of the phenolic modified epoxy resin, more preferably 2 to 3 wt %; and / or,

[0027] The amount of the surfactant is 0.3-0.8 wt % of the weight of the phenolic modified epoxy resin, more preferably 0.5-0.6 wt %; and / or,

[0028] The weight ratio of the deionized water to the phenolic modified epoxy resin is 1:(0.5-1.5), more preferably 1:(0.8-1.2); and / or,

[0029] The water-oil amphiphilic substance is an organic polyol, more preferably polyethylene glycol, such as at least one of polyethylene glycol PEG-1000, polyethylene glycol PEG-2000, polyethylene glycol PEG-3000, and polyethylene glycol PEG-4000. Further preferably, the molecular weight of the polyethylene glycol is 1500-2500. Polyethylene glycol is an water-oil amphiphilic substance, a portion of which is connected to the epoxy resin to form a lipophilic group and the other portion is used as a hydrophilic group, thereby forming an emulsifier composed of the epoxy resin, which can more easily achieve the effect of self-emulsification. Polyethylene glycol, due to its relatively simple molecule, can reduce the complexity of the molecular structure and facilitate subsequent processing. A small amount of ethers such as propylene glycol methyl ether as an emulsification accelerator can accelerate the emulsification process and stabilize the emulsion state; and / or,

[0030] The emulsification accelerator is an organic ether, more preferably propylene glycol methyl ether; and / or,

[0031] The surfactant is at least one of sodium lauryl sulfate, sodium lauryl sulfonate, sodium dodecylbenzene sulfonate, and sodium polyacrylate, more preferably sodium lauryl sulfate; and / or,

[0032] The heating and heat preservation temperature is 80-85°C, and / or the time is 20-40 minutes; and / or,

[0033] The stirring reaction time is 2 to 3 hours, and / or the rotation speed is 50 to 100 r / min; and / or,

[0034] The stirring and dispersing time is 30 to 60 minutes, and / or the rotation speed is 80 to 100 r / min.

[0035] In a preferred embodiment of the present invention, the phenolic modified epoxy resin is prepared by the following method:

[0036] The epoxy compound, phenolic resin and solvent B are heated to reflux and stirred until the phenolic resin is completely dissolved, and then catalyst B is added to react with stirring. After the reaction is completed, centrifugation, drying, washing with water and vacuum drying are performed to obtain the phenolic modified epoxy resin; preferably,

[0037] The molar ratio of the phenolic resin to the epoxy compound is 1:(3-6), more preferably 1:(3.5-5); and / or,

[0038] The solvent B does not participate in the reaction, and technicians can control the amount of addition according to the actual equipment, without specific proportion restrictions; and / or,

[0039] The amount of the catalyst B is 0.3-0.7 wt% of the weight of the epoxy compound, more preferably 0.5-0.6 wt%; and / or,

[0040] The epoxy compound is epichlorohydrin, which can be a commonly used epoxy compound in the art, and is preferably epichlorohydrin from an economic point of view; and / or,

[0041] The phenolic resin is a linear phenolic resin, more preferably, the linear phenolic resin has a functionality of 3.5 to 5; and / or,

[0042] The solvent B is toluene, and the solvent B can be a commonly used solvent in the art, preferably toluene, which has a simple structure and fewer side reactions; and / or,

[0043] The catalyst B is sodium hydroxide, which is easier to remove; and / or,

[0044] The heating reflux temperature is 65-75° C.; and / or,

[0045] The stirring reaction is carried out at a temperature of 90 to 100° C., and / or for a time of 15 to 17 hours, and / or at a rotation speed of 50 to 100 r / min.

[0046] A second object of the present invention is to provide a method for preparing the aqueous hyperbranched epoxy resin emulsion as described in one of the objects of the present invention.

[0047] The preparation method of the aqueous hyperbranched epoxy resin emulsion of the present invention comprises:

[0048] The hyperbranched phenolic modified epoxy resin is heated and stirred, and then an emulsifier aqueous solution is added dropwise, and deionized water is added to cause the reaction system to undergo phase transition. After heat preservation and dispersion, the reaction system is cooled, and deionized water is added to adjust the solid content to obtain the epoxy resin emulsion; preferably,

[0049] The amount of the emulsifier aqueous solution is 8 to 25 wt %, more preferably 12 to 18 wt %, based on the weight of the hyperbranched phenolic modified epoxy resin; and / or,

[0050] The heating and stirring temperature is 80-90°C, and / or the time is 30-45 minutes, and / or the rotation speed is 50-80 r / min; and / or,

[0051] The heat preservation and dispersion time is 30 to 50 minutes; and / or,

[0052] The temperature after cooling is room temperature; and / or,

[0053] The solid content is 48-52%.

[0054] The following solutions can be adopted:

[0055] (1) Add the epoxy compound (such as epichlorohydrin) and phenolic resin into a four-necked flask, add solvent B (such as toluene) to dissolve, heat to 65-75°C in an oil bath and maintain, condense and reflux with a reflux tube, and continuously stir and disperse until the resin is basically completely dissolved;

[0056] (2) Add catalyst B (such as sodium hydroxide), stir and disperse at 50-100 r / min and heat to 90-100°C, and keep reacting for 15-17 hours;

[0057] (3) The obtained product is centrifuged and dried to remove the remaining solvent and unreacted raw materials, then washed twice with water, and vacuum-dried at about 80° C. for 24 h to obtain a phenolic modified epoxy resin;

[0058] (4) adding the phenolic modified epoxy resin obtained in step (3) and the water-oil amphiphilic substance (such as polyethylene glycol) into a four-necked flask, heating the mixture to 80-85° C. in an oil bath and maintaining the temperature for 20-40 min, slowly adding an emulsification promoter (such as propylene glycol methyl ether) dropwise, and continuously dispersing and mixing the mixture at a mechanical stirring speed of 50-100 r / min for 2-3 h; then adding deionized water and a surfactant, and dispersing and mixing the mixture at a high speed of 80-100 r / min for 30-60 min to obtain an emulsifier aqueous solution;

[0059] (5) Add solvent A (such as benzene), polyglycerol, and the phenolic modified epoxy resin obtained in step (3) into a four-necked flask, heat to 70-80° C. in an oil bath and keep warm, use a reflux tube to condense and reflux, continuously stir and disperse, add catalyst A (such as triethylamine and / or pyridine), stir and disperse at 50-100 r / min for 20-30 min, then slowly add a strong organic acid (such as p-toluenesulfonic acid), react for 4-6 h, purify, wash with water, and dry to obtain a hyperbranched phenolic epoxy resin.

[0060] (6) Add the hyperbranched phenolic modified epoxy resin obtained in step (5), heat to 80-90° C. in an oil bath and maintain the temperature, and stir the mixture at 50-80 rpm for 30-45 min. Slowly dropwise add the aqueous emulsifier solution obtained in step (4), and then slowly add deionized water until the viscosity of the system decreases rapidly. At this time, the system undergoes a phase transition from an oil-in-water structure to an oil-in-water structure. Maintain the temperature for 30-50 min, then stop heating and cool to room temperature. Then, add an appropriate amount of deionized water to adjust the solid content to 48-52%, and finally obtain the aqueous hyperbranched epoxy resin emulsion.

[0061] The water-based hyperbranched epoxy resin emulsion of the present invention is a self-emulsifying emulsion. The resin and emulsifier in the self-emulsifying emulsion system have similar main components and structures, and similar compatibility with epoxy curing agents. After cross-linking, it can form a relatively uniform three-dimensional cross-linked network system, which can enhance the strength of the coating system. At the same time, the emulsifier molecular chain incorporates a water-oil amphiphilic substance (such as polyethylene glycol) with good flexibility, which provides a certain toughness to the coating system.

[0062] The third object of the present invention is to provide a long-lasting anti-corrosion, temperature-resistant chromium-free water-based hyperbranched epoxy anti-corrosion primer.

[0063] The long-lasting anticorrosion, temperature-resistant, chromium-free water-based hyperbranched epoxy anticorrosion primer of the present invention is prepared from raw materials comprising the following components:

[0064] Component A and component B;

[0065] Component A includes epoxy curing agent, deionized water, anti-rust filler, temperature-resistant powder, additives, pigments and fillers, co-crosslinking agent and co-solvent;

[0066] Component B comprises the aqueous hyperbranched epoxy resin emulsion as described in one of the objectives of the present invention or the aqueous hyperbranched epoxy resin emulsion prepared by the method described in the second objective of the present invention, deionized water and a film-forming aid;

[0067] Taking the epoxy curing agent in component A as 100 parts by weight:

[0068]

[0069] Taking the waterborne epoxy resin emulsion in component B as 100 parts by weight:

[0070] 100 parts by weight of water-based epoxy resin emulsion;

[0071] 22-78 parts by weight of deionized water;

[0072] 2-4.5 parts by weight of film-forming aid.

[0073] In a preferred embodiment of the present invention:

[0074] Taking the epoxy curing agent in component A as 100 parts by weight:

[0075]

[0076]

[0077] Taking the waterborne epoxy resin emulsion in component B as 100 parts by weight:

[0078] 100 parts by weight of water-based epoxy resin emulsion;

[0079] 30-52 parts by weight of deionized water;

[0080] 3-3.5 parts by weight of film-forming aid;

[0081] The weight ratio of component A to component B is (1-1.2):1, preferably (1-1.1):1.

[0082] In a preferred embodiment of the present invention:

[0083] The epoxy curing agent is an amine curing agent, preferably at least one of a modified fatty amine and a modified alicyclic amine. More preferably, the functionality of the amine curing agent is 2 to 3, and / or the active hydrogen equivalent is 400 to 450 g / eq. The amine curing agent can be an amine curing agent commonly used in the art, such as an amine curing agent produced by Huntsman; and / or,

[0084] The rust-proof filler is at least one of modified zinc phosphate, aluminum tripolyphosphate, zinc aluminum phosphate, strontium aluminum polyphosphate, zinc strontium phosphate, and zinc phosphomolybdate, preferably a combination of three or more; and / or,

[0085] The particle size of the temperature-resistant powder is 25 to 35 μm, and the powder is preferably at least one of ultrafine thermoplastic polyimide powder and ultrafine thermosetting polyimide powder, and more preferably a mixture of ultrafine thermoplastic polyimide powder and ultrafine thermosetting polyimide powder. Further preferably, the weight ratio of the ultrafine thermoplastic polyimide powder to the ultrafine thermosetting polyimide powder is 1:(0.5 to 0.8); and / or,

[0086] The additives are commonly used in the art, such as at least one of additive BYK019, additive BYK024, additive BYK190, additive BYK180, additive BYK181, additive BYK250, additive BYK348, and additive BYK333. The additives are commonly used in the art, such as additives produced by BYK Chemical; preferably, three or more are used in combination, such as additive BYK019 / additive BYK A combination of BYK190 / additive BYK333, a combination of BYK024 / additive BYK348 / additive BYK333, a combination of BYK024 / additive BYK250 / additive BYK348, a combination of BYK180 / additive BYK348 / additive BYK333, a combination of BYK181 / additive BYK348 / additive BYK333, etc.; and / or,

[0087] The pigment and filler is at least one of titanium dioxide, talc, barium sulfate, mica powder, organic bentonite, phthalocyanine green, phthalocyanine blue, and carbon black, preferably a combination of three or more; the titanium dioxide is preferably rutile titanium dioxide, such as rutile titanium dioxide R930, the talc is preferably fine talc, such as 1250 mesh fine talc, and the barium sulfate is preferably aqueous precipitated barium sulfate; and / or,

[0088] The auxiliary cross-linking agent is at least one of 2-amino-2-methyl-1-propanol and 2,4,6-tris(dimethylaminomethyl)phenol; and / or

[0089] The cosolvent is at least one of n-butanol, isopropanol, tert-butanol, diacetone alcohol, propylene glycol methyl ether, ethanol, acetone, and butanone; and / or,

[0090] The film-forming aid is at least one of propylene glycol methyl ether, dipropylene glycol methyl ether, ethylene glycol butyl ether, diethylene glycol butyl ether, propylene glycol butyl ether, and ethylene glycol tert-butyl ether.

[0091] The fourth object of the present invention is to provide a method for preparing the long-lasting anti-corrosion, temperature-resistant, chromium-free water-based hyperbranched epoxy anti-corrosion primer as described in the third object of the present invention.

[0092] The preparation method of the long-lasting anticorrosion, temperature-resistant chromium-free water-based hyperbranched epoxy anticorrosion primer of the present invention is characterized in that the method comprises:

[0093] The raw materials of component A are mixed and ground according to the weight parts to prepare component A; the raw materials of component B are mixed according to the weight parts to prepare component B; and the anti-corrosion primer is prepared after mixing components A and B.

[0094] The following solutions can be adopted:

[0095] (A) The epoxy curing agent and deionized water are mixed uniformly according to the weight parts, the auxiliary agent, the auxiliary cross-linking agent and the auxiliary solvent are added according to the weight parts, and after mixing uniformly, the rust-proof filler, the temperature-resistant powder and the pigment filler are added and mixed uniformly using a disperser.

[0096] (B) Grind the mixed material to a fineness of less than 40 μm using a basket sand mill or a horizontal sand mill, and stir and disperse the mixed material uniformly using a disperser to obtain component A.

[0097] (C) The aqueous hyperbranched epoxy resin emulsion, deionized water and a film-forming aid are uniformly dispersed at a low speed using a disperser according to the aforementioned weight proportions to prepare component B.

[0098] (D) Mix the prepared component A and component B in a weight ratio of (1-1.2):1 and use. It can be applied by spraying or brushing, and can provide long-term corrosion protection when applied to aluminum alloy substrates.

[0099] The water-based hyperbranched epoxy resin emulsion of component B in the long-lasting anticorrosion and temperature-resistant chromium-free water-based hyperbranched epoxy anticorrosion primer of the present invention is not ground, does not contain powder, and has better stability.

[0100] The fifth object of the present invention is to provide a long-term anti-corrosion, heat-resistant chromium-free water-based hyperbranched epoxy anti-corrosion primer as described in the third object of the present invention, or a long-term anti-corrosion, heat-resistant chromium-free water-based hyperbranched epoxy anti-corrosion primer prepared by the method described in the fourth object of the present invention, and use it in the field of long-term heat resistance and corrosion resistance of aluminum alloys.

[0101] In the formula of the long-lasting anti-corrosion and heat-resistant chromium-free water-based hyperbranched epoxy anti-corrosion primer of the present invention, after the water-based hyperbranched epoxy resin emulsion is used in combination with the epoxy curing agent, by adding suitable fillers and additives and other ingredients, the prepared paint film has the advantages of fast drying speed, good adhesion, good water and oil resistance, high hardness, high strength, good shielding properties, excellent long-term anti-corrosion and heat resistance.

[0102] The long-lasting anticorrosion, temperature-resistant, chromium-free water-based hyperbranched epoxy anticorrosion primer system of the present invention contains no chromium-containing fillers, no aluminum powder, no zinc powder, etc., and can meet the current green environmental protection requirements. DETAILED DESCRIPTION

[0103] The present invention will be described in detail below with reference to specific embodiments. It is necessary to point out that the following embodiments are only used to further illustrate the present invention and are not to be construed as limiting the scope of protection of the present invention. Non-essential improvements and adjustments made by those skilled in the art to the present invention based on the contents of the present invention still fall within the scope of protection of the present invention.

[0104] The raw materials used in the examples and comparative examples of the present invention are all conventional commercially available raw materials.

[0105] The test methods in the embodiments of the present invention and the comparative examples are shown in Table 1 below:

[0106] Table 1

[0107]

[0108] [Example 1]

[0109] Preparation of waterborne hyperbranched epoxy resin emulsion:

[0110] (1) 700 g of a linear phenolic resin with a functionality of about 4 and 650 g of epichlorohydrin were added to a four-necked flask at a molar ratio of about 1:4.5, and about 800 g of toluene was added to dissolve the mixture. The mixture was heated to about 65° C. in an oil bath and maintained at this temperature. The mixture was condensed and refluxed using a reflux tube, and the mixture was continuously stirred and dispersed until the resin was substantially completely dissolved.

[0111] (2) Add 1.95 g of sodium hydroxide, set the speed to 55 r / min for dispersion, and raise the temperature to about 95 ° C. and keep the reaction for 15 h;

[0112] (3) The obtained product is centrifuged and dried to remove the remaining solvent and unreacted raw materials, then washed twice with water, and vacuum-dried at about 80° C. for 24 h to obtain a phenolic modified epoxy resin;

[0113] (4) 30 g of the phenolic modified epoxy resin prepared in step (3) and 100 g of polyethylene glycol PEG-2000 (molecular weight of about 2000) were added to a four-necked flask, wherein the molar ratio of the phenolic modified epoxy resin to the polyethylene glycol PEG-2000 was 1:5. The mixture was heated to about 82° C. in an oil bath and maintained for 30 min. 0.7 g of propylene glycol methyl ether was slowly added dropwise, and the mixture was continuously dispersed and mixed for 2 h using mechanical stirring at a stirring speed of 80 r / min. 35 g of deionized water and 0.16 g of sodium lauryl sulfate were then added, and the mixture was dispersed and mixed using high-speed stirring for 30 min to obtain an emulsifier aqueous solution at a stirring speed of 80 r / min.

[0114] (5) About 500 g of benzene, 100 g of tetraglycerol, and 650 g of the phenolic-modified epoxy resin obtained in step (3) were added to a four-necked flask, the molar ratio of tetraglycerol to the phenolic-modified epoxy resin being 1:6.5, and the mixture was heated in an oil bath to about 75 ° C. and kept warm. The mixture was condensed and refluxed using a reflux tube, and stirred and dispersed continuously. 3.36 g of triethylamine was added, and the mixture was stirred and dispersed at a stirring speed of 90 r / min for 30 min. Then, 120 g of p-toluenesulfonic acid was slowly added, the molar ratio of p-toluenesulfonic acid to the phenolic-modified epoxy resin being about 1:1.5. After reacting for 5.5 h, the mixture was purified, washed with water, and dried to obtain a hyperbranched phenolic-modified epoxy resin.

[0115] (6) Add 300 g of the hyperbranched phenolic modified epoxy resin prepared in step (5), heat to 80° C. in an oil bath and maintain the temperature, and continuously disperse and stir at a speed of 70 r / min for about 35 min. Slowly dropwise add 53 g of the prepared emulsifier aqueous solution, and then slowly add deionized water until the viscosity of the system decreases rapidly, at which point the system undergoes a phase transition from a water-in-oil structure to an oil-in-water structure. Maintain the temperature and disperse for 30 min, then stop heating and cool to room temperature, then add an appropriate amount of deionized water to adjust the solid content to about 50%, thereby preparing an aqueous hyperbranched epoxy resin emulsion.

[0116] [Example 2]

[0117] Preparation of waterborne hyperbranched epoxy resin emulsion:

[0118] (1) 700 g of a linear phenolic resin with a functionality of about 3.5 and 440 g of epichlorohydrin were added to a four-necked flask at a molar ratio of about 1:3, and about 700 g of toluene was added to dissolve the mixture. The mixture was heated to about 70° C. in an oil bath and maintained at this temperature. The mixture was condensed and refluxed using a reflux tube, and the mixture was continuously stirred and dispersed until the resin was substantially completely dissolved.

[0119] (2) Add 1.8 g of sodium hydroxide, set the speed to 70 r / min for dispersion, and raise the temperature to about 92 °C, and keep the reaction for 15 h;

[0120] (3) The obtained product is centrifuged and dried to remove the remaining solvent and unreacted raw materials, then washed twice with water, and vacuum-dried at about 80° C. for 24 h to obtain a phenolic modified epoxy resin;

[0121] (4) 30 g of the phenolic modified epoxy resin prepared in step (3) and 100 g of polyethylene glycol PEG-2000 were added to a four-necked flask, wherein the molar ratio of the phenolic modified epoxy resin to the polyethylene glycol PEG-2000 was 1:3. The mixture was heated to about 83° C. in an oil bath and maintained for 20 min. 0.3 g of propylene glycol methyl ether was slowly added dropwise, and the mixture was continuously dispersed and mixed for 2 h by mechanical stirring at a stirring speed of 80 r / min. 30 g of deionized water and 0.1 g of sodium lauryl sulfate were then added, and the mixture was dispersed and mixed for 30 min by high-speed stirring at a stirring speed of 80 r / min to obtain an emulsifier aqueous solution.

[0122] (5) About 500 g of benzene, 100 g of tetraglycerol, and 650 g of the phenolic-modified epoxy resin obtained in step (3) were added to a four-necked flask, the molar ratio of tetraglycerol to the phenolic-modified epoxy resin being 1:6, and the mixture was heated in an oil bath to about 75 ° C. and kept warm. The mixture was condensed and refluxed using a reflux tube while being stirred and dispersed continuously. 1.98 g of pyridine was added, and the mixture was stirred and dispersed at a stirring speed of 90 r / min for 30 min. Then, 150 g of p-toluenesulfonic acid was slowly added, the molar ratio of p-toluenesulfonic acid to the phenolic-modified epoxy resin being 1:1.2. After reacting for 5.5 h, the mixture was purified, washed with water, and dried to obtain a hyperbranched phenolic-modified epoxy resin.

[0123] (6) Add 300 g of the hyperbranched phenolic modified epoxy resin prepared in step (5), heat to 80° C. in an oil bath and maintain the temperature, and continuously disperse and stir at a speed of 65 r / min for about 40 min. Slowly dropwise add 25 g of the prepared emulsifier aqueous solution, and then slowly add deionized water until the viscosity of the system decreases rapidly, at which point the system undergoes a phase transition from a water-in-oil structure to an oil-in-water structure. Maintain the temperature and disperse for 30 min, then stop heating and cool to room temperature, then add an appropriate amount of deionized water to adjust the solid content to about 50%, thereby preparing an aqueous hyperbranched epoxy resin emulsion.

[0124] [Example 3]

[0125] Preparation of waterborne hyperbranched epoxy resin emulsion:

[0126] (1) 700 g of a linear phenolic resin with a functionality of about 5 and 850 g of epichlorohydrin were added to a four-necked flask at a molar ratio of about 1:6, and about 950 g of toluene was added to dissolve the mixture. The mixture was heated to about 75° C. in an oil bath and maintained at this temperature. The mixture was condensed and refluxed using a reflux tube, and the mixture was continuously stirred and dispersed until the resin was substantially completely dissolved.

[0127] (2) Add 5.9 g of sodium hydroxide, set the speed to 95 r / min for dispersion, and raise the temperature to about 98 ° C. and keep the reaction for 17 h;

[0128] (3) The obtained product is centrifuged and dried to remove the remaining solvent and unreacted raw materials, then washed twice with water, and vacuum-dried at about 80° C. for 24 h to obtain a phenolic modified epoxy resin;

[0129] (4) 30 g of the phenolic modified epoxy resin and 100 g of polyethylene glycol PEG-2000 prepared in step (3) were added to a four-necked flask, with the molar ratio of the phenolic modified epoxy resin to the polyethylene glycol PEG-2000 being 1:6.5. The mixture was heated to about 83° C. in an oil bath and maintained for 40 min. 1.5 g of propylene glycol methyl ether was slowly added dropwise, and the mixture was continuously dispersed and mixed for 3 h using mechanical stirring at a stirring speed of 95 r / min. 60 g of deionized water and 0.24 g of sodium lauryl sulfate were then added, and the mixture was dispersed and mixed using high-speed stirring for 50 min to obtain an emulsifier aqueous solution at a stirring speed of 95 r / min.

[0130] (5) About 500 g of benzene, 100 g of tetraglycerol, and 650 g of the phenolic-modified epoxy resin obtained in step (3) were added to a four-necked flask, the molar ratio of tetraglycerol to the phenolic-modified epoxy resin being 1:7.5, and the mixture was heated in an oil bath to about 80 ° C. and kept warm. The mixture was condensed and refluxed using a reflux tube, and stirring and dispersing was continued. 5.6 g of triethylamine was added, and the mixture was stirred and dispersed at a stirring speed of 90 r / min for 30 min. Then, 138 g of p-toluenesulfonic acid was slowly added, and the molar ratio of p-toluenesulfonic acid to the phenolic-modified epoxy resin was 1:1.3. After reacting for 5.5 h, the mixture was purified, washed with water, and dried to obtain a hyperbranched phenolic-modified epoxy resin.

[0131] (6) Add 300 g of the hyperbranched phenolic modified epoxy resin prepared in step (5), heat to about 88° C. in an oil bath and maintain the temperature, and continuously disperse and stir at a speed of 75 r / min for about 40 min. Slowly dropwise add 74 g of the prepared emulsifier aqueous solution, and then slowly add deionized water until the viscosity of the system decreases rapidly, at which point the system undergoes a phase transition from a water-in-oil structure to an oil-in-water structure. Maintain the temperature and disperse for 30 min, then stop heating and cool to room temperature, then add an appropriate amount of deionized water to adjust the solid content to about 50%, thereby preparing an aqueous hyperbranched epoxy resin emulsion.

[0132] [Example 4]

[0133] 1. The synthesis of water-based hyperbranched epoxy resin emulsion is the same as that in Example 1.

[0134] 2. Preparation of long-lasting anticorrosion, heat-resistant chromium-free waterborne hyperbranched epoxy anticorrosion primer:

[0135] Long-lasting anti-corrosion, heat-resistant, chromium-free water-based hyperbranched epoxy anti-corrosion primer includes component A and component B;

[0136] Component A includes: 100 parts by weight of epoxy curing agent Aradur3986 (modified fatty amine, active hydrogen equivalent of about 415g / eq), 32 parts by weight of deionized water, 3 parts by weight of modified zinc phosphate, 4.5 parts by weight of aluminum tripolyphosphate, 2 parts by weight of aluminum zinc phosphate, 6 parts by weight of strontium aluminum polyphosphate, 8 parts by weight of ultrafine thermoplastic polyimide powder (particle size not exceeding 35 microns), 4 parts by weight of ultrafine thermosetting polyimide powder (particle size not exceeding 35 microns), 0.8 parts by weight of additive BYK019, 2 parts by weight of additive BYK190, 0.8 parts by weight of additive BYK333, and rutile titanium dioxide R930. 20 parts by weight, 1250 mesh fine talc 25 parts by weight, aqueous precipitated barium sulfate 28 parts by weight, phthalocyanine green 1 part by weight, co-crosslinking agent 2,4,6-tris(dimethylaminomethyl)phenol 0.6 parts by weight, co-solvent diacetone alcohol 6 parts by weight;

[0137] Component B comprises: 100 parts by weight of the aqueous hyperbranched epoxy resin emulsion prepared above, 47 parts by weight of deionized water, and 3.5 parts by weight of a film-forming aid, propylene glycol methyl ether.

[0138] Specific preparation method of long-lasting anticorrosion, heat-resistant chromium-free water-based hyperbranched epoxy anticorrosion primer and preparation of its sample:

[0139] Preparation of component A:

[0140] 1) Mix the epoxy curing agent and deionized water in the above-mentioned parts by weight, add the auxiliary agent, co-crosslinking agent and cosolvent liquid material in the above-mentioned parts by weight, disperse at a speed of 500 rpm, and stir for 15 minutes; after mixing evenly, add the rust-proof filler, heat-resistant powder and pigment filler, continue to mix evenly using a disperser, and stir for 35 minutes.

[0141] 2) Grind the mixture to a fineness of about 35 μm using a basket sand mill, control the sand mill discharge temperature to not exceed 60° C., and stir and disperse the mixture using a disperser at a speed of 500 rpm for 35 minutes to obtain component A.

[0142] Preparation of component B:

[0143] The aqueous hyperbranched epoxy resin emulsion, deionized water, and film-forming aid were uniformly dispersed in a disperser at a low speed of 200 rpm and a stirring time of 10 minutes according to the above-mentioned parts by weight to prepare component B.

[0144] Coating method: Mix the prepared component A and component B in a weight ratio of 1.1:1 and apply to the aluminum alloy sample by spraying.

[0145] [Example 5]

[0146] 1. The synthesis of water-based hyperbranched epoxy resin emulsion is the same as that in Example 2.

[0147] 2. Preparation of long-lasting anticorrosion, heat-resistant chromium-free waterborne hyperbranched epoxy anticorrosion primer:

[0148] Long-lasting anti-corrosion, heat-resistant, chromium-free water-based hyperbranched epoxy anti-corrosion primer includes component A and component B;

[0149] Component A comprises: 100 parts by weight of epoxy curing agent Aradur 3986, 21 parts by weight of deionized water, 1 part by weight of modified zinc phosphate, 2 parts by weight of aluminum tripolyphosphate, 3.6 parts by weight of strontium aluminum polyphosphate, 1.6 parts by weight of zinc phosphomolybdate, 6 parts by weight of ultrafine thermoplastic polyimide powder (particle size not exceeding 35 microns), 3.2 parts by weight of ultrafine thermosetting polyimide powder (particle size not exceeding 35 microns), 0.5 parts by weight of additive BYK024, 1.2 parts by weight of additive BYK348, 0.5 parts by weight of additive BYK333, 20 parts by weight of rutile titanium dioxide R930, 26 parts by weight of 1250 mesh fine talc, 20 parts by weight of aqueous precipitated barium sulfate, 1 part by weight of phthalocyanine green, 0.3 parts by weight of co-crosslinking agent 2-amino-2-methyl-1-propanol, and 3.6 parts by weight of co-solvent butanone;

[0150] Component B comprises: 100 parts by weight of the aqueous hyperbranched epoxy resin emulsion prepared above, 23 parts by weight of deionized water, and 2 parts by weight of a film-forming aid, propylene glycol butyl ether.

[0151] The specific preparation method of the long-lasting anti-corrosion, temperature-resistant chromium-free water-based hyperbranched epoxy anti-corrosion primer and the preparation of its sample are the same as those in Example 4.

[0152] [Example 6]

[0153] 1. The synthesis of the aqueous hyperbranched epoxy resin emulsion is the same as that in Example 3.

[0154] 2. Preparation of long-lasting anticorrosion, heat-resistant chromium-free waterborne hyperbranched epoxy anticorrosion primer:

[0155] Long-lasting anti-corrosion, heat-resistant, chromium-free water-based hyperbranched epoxy anti-corrosion primer includes component A and component B;

[0156] Component A includes: 100 parts by weight of epoxy curing agent Aradur3986, 50 parts by weight of deionized water, 10 parts by weight of modified zinc phosphate, 3.8 parts by weight of aluminum tripolyphosphate, 5 parts by weight of strontium aluminum polyphosphate, 6 parts by weight of zinc phosphomolybdate, 12 parts by weight of ultrafine thermoplastic polyimide powder (particle size not exceeding 35 microns), 6 parts by weight of ultrafine thermosetting polyimide powder (particle size not exceeding 35 microns), 1.6 parts by weight of additive BYK024, 2.5 parts by weight of additive BYK348, 1.8 parts by weight of additive BYK333, 30 parts by weight of rutile titanium dioxide R930, 30 parts by weight of 1250 mesh fine talc, 25 parts by weight of aqueous precipitated barium sulfate, 1.5 parts by weight of phthalocyanine green, 1 part by weight of co-crosslinking agent 2,4,6-tris(dimethylaminomethyl)phenol, and 8 parts by weight of co-solvent butanone;

[0157] Component B comprises: 100 parts by weight of the aqueous hyperbranched epoxy resin emulsion prepared above, 76 parts by weight of deionized water, and 4.5 parts by weight of a film-forming aid, diethylene glycol butyl ether.

[0158] The specific preparation method of the long-lasting anti-corrosion, temperature-resistant chromium-free water-based hyperbranched epoxy anti-corrosion primer and the preparation of its sample are the same as those in Example 4.

[0159] [Comparative Example 1]

[0160] Preparation of chromium-free waterborne epoxy anticorrosive primer:

[0161] Chromium-free waterborne epoxy anticorrosive primer includes component A and component B;

[0162] Component A includes: 100 parts by weight of epoxy curing agent Aradur3986, 32 parts by weight of deionized water, 3 parts by weight of modified zinc phosphate, 4.5 parts by weight of aluminum tripolyphosphate, 2 parts by weight of zinc aluminum phosphate, 6 parts by weight of strontium aluminum polyphosphate, 0.8 parts by weight of additive BYK024, 2 parts by weight of additive BYK348, 0.8 parts by weight of additive BYK333, 20 parts by weight of rutile titanium dioxide R930, 25 parts by weight of 1250 mesh fine talc, 28 parts by weight of aqueous precipitated barium sulfate, 1 part by weight of phthalocyanine green, 0.6 parts by weight of co-crosslinking agent 2,4,6-tris(dimethylaminomethyl)phenol, and 6 parts by weight of co-solvent butanone;

[0163] Component B includes: 100 parts by weight of commercially available phenolic epoxy resin emulsion, 31.5 parts by weight of deionized water, and 3.5 parts by weight of film-forming aid propylene glycol methyl ether.

[0164] The specific preparation method of the chromium-free waterborne epoxy anticorrosive primer and the preparation of its sample are the same as those in Example 4.

[0165] [Comparative Example 2]

[0166] Preparation of chromium-free waterborne epoxy anticorrosive primer:

[0167] Chromium-free waterborne epoxy anticorrosive primer includes component A and component B;

[0168] Component A includes: 100 parts by weight of epoxy curing agent Aradur3986, 32 parts by weight of deionized water, 3 parts by weight of modified zinc phosphate, 4.5 parts by weight of aluminum tripolyphosphate, 2 parts by weight of zinc aluminum phosphate, 6 parts by weight of strontium aluminum polyphosphate, 0.8 parts by weight of additive BYK024, 2 parts by weight of additive BYK348, 0.8 parts by weight of additive BYK333, 20 parts by weight of rutile titanium dioxide R930, 25 parts by weight of 1250 mesh fine talc, 28 parts by weight of aqueous precipitated barium sulfate, 1 part by weight of phthalocyanine green, 0.6 parts by weight of co-crosslinking agent 2,4,6-tris(dimethylaminomethyl)phenol, and 6 parts by weight of co-solvent butanone;

[0169] Component B includes: 100 parts by weight of commercially available bisphenol A waterborne epoxy resin emulsion, 30 parts by weight of deionized water, and 3.5 parts by weight of a film-forming aid, propylene glycol methyl ether.

[0170] The specific preparation method of the chromium-free waterborne epoxy anticorrosive primer and the preparation of its sample are the same as those in Example 4.

[0171] [Comparative Example 3]

[0172] Preparation of chromium-free waterborne epoxy anticorrosive primer:

[0173] Chromium-free waterborne epoxy anticorrosive primer includes component A and component B;

[0174] Component A includes: 100 parts by weight of epoxy curing agent Aradur3986, 32 parts by weight of deionized water, 3 parts by weight of modified zinc phosphate, 4.5 parts by weight of aluminum tripolyphosphate, 2 parts by weight of zinc aluminum phosphate, 6 parts by weight of strontium aluminum polyphosphate, 0.8 parts by weight of additive BYK024, 2 parts by weight of additive BYK348, 0.8 parts by weight of additive BYK333, 20 parts by weight of rutile titanium dioxide R930, 25 parts by weight of 1250 mesh fine talc, 28 parts by weight of aqueous precipitated barium sulfate, 1 part by weight of phthalocyanine green, 0.6 parts by weight of co-crosslinking agent 2,4,6-tris(dimethylaminomethyl)phenol, and 6 parts by weight of co-solvent butanone;

[0175] Component B includes: 100 parts by weight of a commercially available hyperbranched waterborne epoxy resin emulsion, 36 parts by weight of deionized water, and 3.5 parts by weight of a film-forming aid, propylene glycol methyl ether.

[0176] The specific preparation method of the chromium-free waterborne epoxy anticorrosive primer and the preparation of its sample are the same as those in Example 4.

[0177] [Comparative Example 4]

[0178] Preparation of chromium-free waterborne epoxy anticorrosive primer:

[0179] Chromium-free waterborne epoxy anticorrosive primer includes component A and component B;

[0180] Component A includes: 100 parts by weight of epoxy curing agent Aradur3986, 32 parts by weight of deionized water, 3 parts by weight of modified zinc phosphate, 4.5 parts by weight of aluminum tripolyphosphate, 2 parts by weight of aluminum zinc phosphate, 6 parts by weight of strontium aluminum polyphosphate, 2.3 parts by weight of strontium chromate, 8 parts by weight of ultrafine thermoplastic polyimide powder (particle size not exceeding 35 microns), 4 parts by weight of ultrafine thermosetting polyimide powder (particle size not exceeding 35 microns), 0.8 parts by weight of additive BYK024, 2 parts by weight of additive BYK348, 0.8 parts by weight of additive BYK333, 20 parts by weight of rutile titanium dioxide R930, 25 parts by weight of 1250 mesh fine talc, 28 parts by weight of aqueous precipitated barium sulfate, 1 part by weight of phthalocyanine green, 0.6 parts by weight of co-crosslinking agent 2,4,6-tris(dimethylaminomethyl)phenol, and 6 parts by weight of co-solvent butanone;

[0181] Component B includes: 100 parts by weight of a commercially available hyperbranched waterborne epoxy resin emulsion, 41 parts by weight of deionized water, and 3.5 parts by weight of a film-forming aid, propylene glycol methyl ether.

[0182] The specific preparation method of the chromium-free waterborne epoxy anticorrosive primer and the preparation of its sample are the same as those in Example 4.

[0183] The properties of the samples prepared in Examples 4 to 6 and Comparative Examples 1 to 4 were tested according to the test method in Table 1. The results are shown in Table 2 below:

[0184] Table 2

[0185]

[0186] As can be seen from the above table, the paint films of Examples 4, 5, and 6 of the present invention have faster drying times, and the water resistance, hydraulic oil resistance, adhesion, and neutral salt spray resistance of the paint films are significantly better than those of Comparative Examples 1 to 3. Compared with the chromium-containing paint Comparative Example 4, the performance difference is not large, but the paint film hardness of Examples 4 to 6 is better than that of Comparative Example 4. The heat resistance of the coating of the embodiment with the addition of heat-resistant powder is also significantly better than that of Comparative Examples 1 to 3. This is mainly because the water-based hyperbranched epoxy resin emulsion used in the present invention is a hyperbranched epoxy resin with phenolic epoxy resin as a branched chain. This structure has more rigid groups and cross-linking points, so that it has a dense cross-linking network after cross-linking, thereby making the paint film have better sealing properties and can play a better long-term anti-corrosion role. At the same time, the thermoplastic polyimide powder as the heat-resistant powder has a high melting enthalpy and can absorb a large amount of heat energy in a high temperature environment. It can provide better heat resistance when combined with the thermosetting polyimide powder.

[0187] All publications, patent applications, patents, and other references mentioned in this specification are incorporated herein by reference. Unless otherwise defined, all technical and scientific terms used in this specification have the meanings conventionally understood by those skilled in the art. In the event of conflict, the definitions in this specification shall prevail.

[0188] When this specification uses the prefix "well known to those skilled in the art", "prior art" or similar terms to introduce materials, substances, methods, steps, devices or components, the objects introduced by the prefix include those commonly used in the art when this application is filed, but also include those that are not commonly used at present but will become generally recognized in the art to be suitable for similar purposes.

[0189] The endpoints and any values of the ranges disclosed in this application document are not limited to the precise ranges or values, and these ranges or values should be understood to include values close to these ranges or values. For numerical ranges, the endpoint values of each range, the endpoint values of each range and a separate point value, and the separate point values can be combined with each other to obtain one or more new numerical ranges, and these numerical ranges should be considered as specifically disclosed in this article. Hereinafter, in principle, each technical solution can be combined with each other to obtain a new technical solution, which should also be considered as specifically disclosed in this article.

[0190] In the context of this specification, any matters or items not mentioned are directly applicable to those known in the art without any changes except those explicitly stated.

[0191] Moreover, any embodiment described herein may be freely combined with one or more other embodiments described herein, and the technical solutions or technical ideas thus formed shall be deemed as part of the original disclosure or original record of the present invention, and shall not be regarded as new content that has not been disclosed or anticipated herein, unless a person skilled in the art considers that the combination is obviously unreasonable.

[0192] Finally, it should be noted that the above content is only used to illustrate the technical solution of the present invention, rather than to limit the scope of protection of the present invention. The claims include the formula ingredients and ratio range and optimization scheme of the present invention. Simple modifications or equivalent substitutions of the technical solution of the present invention by ordinary technicians in this field do not deviate from the essence and scope of the technical solution of the present invention.

Claims

1. A water-based hyperbranched epoxy resin emulsion, characterized in that The epoxy resin emulsion is a self-emulsifying water-based epoxy resin emulsion prepared from raw materials including a hyperbranched phenolic modified epoxy resin and an emulsifier aqueous solution; The hyperbranched phenolic modified epoxy resin is prepared by grafting phenolic modified epoxy resin as a branch chain onto a polyglycerol molecule; The emulsifier aqueous solution is prepared from raw materials including phenolic modified epoxy resin, water-oil amphiphilic substance, emulsification accelerator, deionized water and surfactant.

2. The epoxy resin emulsion according to claim 1, characterized in that The hyperbranched phenolic modified epoxy resin is prepared by the following method: Solvent A, polyglycerol and phenolic modified epoxy resin are heated to reflux and kept warm, catalyst A is added and stirred and dispersed, a strong organic acid is added to carry out grafting reaction, and after the reaction is completed, the hyperbranched phenolic modified epoxy resin is prepared by purification, water washing and drying; preferably, The molar ratio of the polyglycerol to the phenolic modified epoxy resin is 1:(6-8), more preferably 1:(6.5-7); and / or, The amount of the catalyst A is 0.3-0.9 wt % of the weight of the phenolic modified epoxy resin, more preferably 0.5-0.8 wt %; and / or, The molar ratio of the strong organic acid to the phenolic modified epoxy resin is 1:(1.2-1.5), more preferably 1:(1.2-1.3); and / or, The solvent A is benzene; and / or, The polyglycerol is a glycerol polycondensate, and more preferably, the degree of polymerization of the polyglycerol is 3 to 5; and / or, The catalyst A is triethylamine and / or pyridine; and / or, The acidity coefficient of the strong organic acid is -3 to 3, more preferably p-toluenesulfonic acid; and / or, The reflux temperature is 70-80°C; and / or The stirring and dispersing time is 20 to 30 minutes, and / or the rotation speed is 50 to 100 r / min; and / or, The grafting reaction is carried out at a temperature of 70 to 80° C. and / or for a time of 4 to 6 hours.

3. The epoxy resin emulsion according to claim 1, characterized in that The emulsifier aqueous solution is prepared by the following method: The phenolic modified epoxy resin and the water-oil amphiphilic substance are heated and kept warm, an emulsification accelerator is added dropwise and stirred for reaction, and deionized water and a surfactant are added and stirred and dispersed to obtain the emulsifier aqueous solution; preferably, The molar ratio of the phenolic modified epoxy resin to the water-oil amphiphilic substance is 1:(3-7), more preferably 1:(4-5.5); and / or, The amount of the emulsification accelerator is 1 to 5 wt % of the weight of the phenolic modified epoxy resin, more preferably 2 to 3 wt %; and / or, The amount of the surfactant is 0.3-0.8 wt % of the weight of the phenolic modified epoxy resin, more preferably 0.5-0.6 wt %; and / or, The weight ratio of the deionized water to the phenolic modified epoxy resin is 1:(0.5-1.5), more preferably 1:(0.8-1.2); and / or, The water-oil amphiphilic substance is an organic polyol, more preferably polyethylene glycol, and further preferably, the molecular weight of the polyethylene glycol is 1500-2500; and / or, The emulsification accelerator is an organic ether, more preferably propylene glycol methyl ether; and / or, The surfactant is at least one of sodium lauryl sulfate, sodium lauryl sulfonate, sodium dodecylbenzene sulfonate, and sodium polyacrylate, more preferably sodium lauryl sulfate; and / or, The heating and heat preservation temperature is 80-85°C, and / or the time is 20-40 minutes; and / or, The stirring reaction time is 2 to 3 hours, and / or the rotation speed is 50 to 100 r / min; and / or, The stirring and dispersing time is 30 to 60 minutes, and / or the rotation speed is 80 to 100 r / min.

4. The epoxy resin emulsion according to any one of claims 1 to 3, characterized in that The phenolic modified epoxy resin is prepared by the following method: The epoxy compound, phenolic resin and solvent B are heated to reflux and stirred until the phenolic resin is completely dissolved, and then catalyst B is added to react with stirring. After the reaction is completed, centrifugation, drying, washing with water and vacuum drying are performed to obtain the phenolic modified epoxy resin; preferably, The molar ratio of the phenolic resin to the epoxy compound is 1:(3-6), more preferably 1:(3.5-5); and / or, The amount of the catalyst B is 0.3-0.7 wt% of the weight of the epoxy compound, more preferably 0.5-0.6 wt%; and / or, The epoxy compound is epichlorohydrin; and / or, The phenolic resin is a linear phenolic resin, more preferably, the linear phenolic resin has a functionality of 3.5 to 5; and / or, The solvent B is toluene; and / or, The catalyst B is sodium hydroxide; and / or The heating reflux temperature is 65-75° C.; and / or, The stirring reaction is carried out at a temperature of 90 to 100° C., and / or for a time of 15 to 17 hours, and / or at a rotation speed of 50 to 100 r / min.

5. A method for preparing an aqueous hyperbranched epoxy resin emulsion as claimed in any one of claims 1 to 4, characterized in that The method comprises: The hyperbranched phenolic modified epoxy resin is heated and stirred, and then an emulsifier aqueous solution is added dropwise, and deionized water is added to cause the reaction system to undergo phase transition. After heat preservation and dispersion, the reaction system is cooled, and deionized water is added to adjust the solid content to obtain the epoxy resin emulsion; preferably, The amount of the emulsifier aqueous solution is 8 to 25 wt %, more preferably 12 to 18 wt %, based on the weight of the hyperbranched phenolic modified epoxy resin; and / or, The heating and stirring temperature is 80-90°C, and / or the time is 30-45 minutes, and / or the rotation speed is 50-80 r / min; and / or, The heat preservation and dispersion time is 30 to 50 minutes; and / or, The temperature after cooling is room temperature; and / or, The solid content is 48-52%.

6. A long-lasting anti-corrosion, temperature-resistant chromium-free water-based hyperbranched epoxy anti-corrosion primer, characterized in that The anticorrosive primer is prepared from raw materials comprising the following components: Component A and component B; Component A includes epoxy curing agent, deionized water, anti-rust filler, temperature-resistant powder, additives, pigments and fillers, co-crosslinking agent and co-solvent; Component B comprises the aqueous hyperbranched epoxy resin emulsion according to any one of claims 1 to 4 or the aqueous hyperbranched epoxy resin emulsion prepared by the method according to claim 5, deionized water and a film-forming aid; Taking the epoxy curing agent in component A as 100 parts by weight: Taking the waterborne epoxy resin emulsion in component B as 100 parts by weight: 100 parts by weight of water-based epoxy resin emulsion; 22-78 parts by weight of deionized water; 2-4.5 parts by weight of film-forming aid.

7. The anticorrosive primer according to claim 6, characterized in that: Taking the epoxy curing agent in component A as 100 parts by weight: Taking the waterborne epoxy resin emulsion in component B as 100 parts by weight: 100 parts by weight of water-based epoxy resin emulsion; 30-52 parts by weight of deionized water; 3-3.5 parts by weight of film-forming aid; The weight ratio of component A to component B is (1-1.2):1, preferably (1-1.1):

1.

8. The anticorrosive primer according to claim 6 or 7, characterized in that: The epoxy curing agent is an amine curing agent, preferably at least one of a modified fatty amine and a modified alicyclic amine. More preferably, the amine curing agent has a functionality of 2 to 3 and / or an active hydrogen equivalent of 400 to 450 g / eq; and / or, The rust-proof filler is at least one of modified zinc phosphate, aluminum tripolyphosphate, zinc aluminum phosphate, strontium aluminum polyphosphate, zinc strontium phosphate, and zinc phosphomolybdate; and / or, The particle size of the temperature-resistant powder is 25 to 35 μm, and the powder is preferably at least one of ultrafine thermoplastic polyimide powder and ultrafine thermosetting polyimide powder, and more preferably a mixture of ultrafine thermoplastic polyimide powder and ultrafine thermosetting polyimide powder. Further preferably, the weight ratio of the ultrafine thermoplastic polyimide powder to the ultrafine thermosetting polyimide powder is 1:(0.5 to 0.8); and / or, The pigment and filler is at least one of titanium dioxide, talc, barium sulfate, mica powder, organic bentonite, phthalocyanine green, phthalocyanine blue, and carbon black; and / or, The auxiliary cross-linking agent is at least one of 2-amino-2-methyl-1-propanol and 2,4,6-tris(dimethylaminomethyl)phenol; and / or The cosolvent is at least one of n-butanol, isopropanol, tert-butanol, diacetone alcohol, propylene glycol methyl ether, ethanol, acetone, and butanone; and / or, The film-forming aid is at least one of propylene glycol methyl ether, dipropylene glycol methyl ether, ethylene glycol butyl ether, diethylene glycol butyl ether, propylene glycol butyl ether, and ethylene glycol tert-butyl ether.

9. A method for preparing the long-lasting anticorrosive, temperature-resistant, chromium-free waterborne hyperbranched epoxy anticorrosive primer according to any one of claims 6 to 8, characterized in that The method comprises: The raw materials of component A are mixed and ground according to the weight parts to prepare component A; the raw materials of component B are mixed according to the weight parts to prepare component B; and the anti-corrosion primer is prepared after mixing components A and B.

10. Use of the long-lasting anti-corrosion, heat-resistant chromium-free water-based hyperbranched epoxy anti-corrosion primer according to any one of claims 6 to 8 or the long-lasting anti-corrosion, heat-resistant chromium-free water-based hyperbranched epoxy anti-corrosion primer prepared by the method according to claim 9 in the field of long-lasting heat resistance and corrosion protection of aluminum alloys.

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