Synthesis of low viscosity hyperbranched polyether epoxy resin and its application in waterborne epoxy anticorrosive coatings

Abstract

This invention discloses a method for preparing low-viscosity hyperbranched polyether epoxy resin and its application in waterborne epoxy anticorrosive coatings, belonging to the field of coating technology. The method for preparing the hyperbranched polyether epoxy resin is based on the proton transfer polymerization mechanism, using an A2+B3 synthesis strategy. The hyperbranched polyether epoxy resin prepared by this invention can effectively reduce the viscosity of the emulsion system, improve the stability of the epoxy emulsion, and reduce the particle size of the emulsion. It can also be used to modify waterborne epoxy anticorrosive coatings, and the cured coating exhibits excellent toughness, chemical resistance, and salt spray resistance.

Description

Technical Field

[0001] This invention relates to a method for preparing hyperbranched polyether epoxy resin and its application in waterborne epoxy anticorrosive coatings, belonging to the field of anticorrosive coating technology. Background Technology

[0002] Waterborne coatings, using water instead of organic solvents as the dispersion medium, offer simple and safe processes with low construction costs, making them a popular direction for the green development of epoxy coatings. However, the introduction of emulsifiers or hydrophilic groups is unavoidable during the waterborne application of epoxy resins. These hydrophilic segments remain in the cross-linked network after coating curing. Furthermore, the film-forming mechanism of waterborne epoxy coatings changes, leading to defects and porosity during curing. These factors result in waterborne epoxy coatings having inferior mechanical and anti-corrosion properties compared to solvent-based epoxy coatings. Therefore, reducing coating defects and porosity, and improving coating flexibility and density, are key to further developing waterborne epoxy coatings and ultimately replacing solvent-based epoxy coatings.

[0003] In recent years, hyperbranched epoxy resins (EHBPs) have been widely used in the modification of epoxy resins due to their advantages such as low viscosity, high compatibility, and abundant terminal epoxy groups. Through reasonable structural design, hyperbranched epoxy resins can achieve a comprehensive improvement in the mechanical properties and anti-corrosion performance of epoxy coatings. However, most current research on epoxy coating modification is conducted in homogeneous systems, resulting in coatings containing a large amount of organic solvents, which does not conform to the development trend of low-VOC coatings. Patent CN201610345144.X reports a polyether-type hyperbranched polymer synthesized using hydroquinone as the A2 monomer and multifunctional glycidyl ether as the B3 monomer. This polymer was used to formulate solvent-based epoxy resin anti-corrosion coatings, and the toughness and anti-corrosion performance of the prepared coatings were improved.

[0004] Currently, there is still limited research both domestically and internationally on the modification of waterborne epoxy coatings with hyperbranched epoxy resins. Li Xiaoyu's research group synthesized several hyperbranched polyether epoxy resins using diphenols and trifunctional epoxy resins, and used them to modify waterborne epoxy coatings. However, the preparation cost of these hyperbranched polyether epoxy resins is high, and their structures contain many polar groups and have high viscosity, which is detrimental to the preparation of waterborne epoxy coatings and their anti-corrosion properties. Summary of the Invention

[0005] To address the aforementioned problems, this invention provides a method for preparing a low-viscosity hyperbranched polyether epoxy resin and its application in waterborne epoxy anticorrosive coatings. Based on the proton transfer polymerization mechanism, this invention synthesizes a hyperbranched polyether epoxy resin in a one-pot process under solvent-free and purification-free conditions. The obtained resin is blended with bisphenol A type epoxy resin, and the blended resin is emulsified using a commercially available waterborne epoxy emulsifier to modify the waterborne epoxy emulsion with the hyperbranched polyether epoxy resin. The modified waterborne epoxy emulsion is then compounded with a waterborne epoxy curing agent to prepare a waterborne epoxy anticorrosive coating. The coating exhibits excellent toughness, chemical resistance, and corrosion resistance.

[0006] The first objective of this invention is to provide a method for preparing a low-viscosity hyperbranched polyether epoxy resin, wherein a diphenol, a polyfunctional epoxy compound and a catalyst are added to a reactor, a nitrogen atmosphere is maintained, the reaction temperature is 140-180°C, and the reaction time is 6-36 h, to obtain a hyperbranched polyether epoxy resin.

[0007] The multifunctional epoxide is epoxidized soybean oil;

[0008] The diphenol is one or more of hydroquinone, resorcinol, bisphenol A, and bisphenol F;

[0009] The molar ratio of diphenols to polyfunctional epoxy compounds is 1:1.0 to 1:3.0.

[0010] In one embodiment, the catalyst is one or more selected from tetrabutylammonium chloride, tetrabutylammonium bromide, tetrabutylammonium hydroxide, ethyltriphenylphosphine chloride, ethyltriphenylphosphine bromide, triphenylphosphine, and boron trifluoride ether.

[0011] In one embodiment, the catalyst is added in an amount of 0.5 wt% to 2.0 wt% of the total mass of the diphenol and the polyfunctional epoxy compound.

[0012] A second objective of this invention is to provide a hyperbranched polyether epoxy resin prepared according to the above method.

[0013] A third objective of this invention is to provide a hyperbranched polyether epoxy resin modified aqueous epoxy emulsion, comprising the low-viscosity hyperbranched polyether epoxy resin prepared by the above-described preparation method, or the above-described low-viscosity hyperbranched polyether epoxy resin.

[0014] In one embodiment, 10-20 parts of waterborne epoxy emulsifier, 60-110 parts of bisphenol A type epoxy resin, 1-15 parts of the above-mentioned hyperbranched polyether epoxy resin, and 0-10 parts of organic solvent are weighed. The mixture is heated to 60°C and stirred. Under high-speed shearing at 1000-3000 rpm, deionized water is added dropwise. After the emulsion undergoes an inversion, changing from water-in-oil to oil-in-water, the addition of water is stopped, and the current high-speed shearing is maintained for 2 hours. After shearing is completed, the speed is reduced to 800 rpm, and water is added for dispersion for 0.5 hours. The solid content of the emulsion is adjusted to 55 wt% to obtain a hyperbranched polyether epoxy resin modified waterborne epoxy emulsion.

[0015] In one embodiment, the organic solvent is one or more of ethylene glycol monobutyl ether, ethylene glycol dimethyl ether, propylene glycol monobutyl ether, and propylene glycol dimethyl ether.

[0016] The fourth objective of this invention is to provide an application of the above-mentioned low-viscosity hyperbranched polyether epoxy resin in waterborne epoxy anticorrosive coatings.

[0017] In one embodiment, the waterborne epoxy anticorrosive coating comprises, by mass parts, component A and component B; component A is the hyperbranched polyether epoxy resin modified waterborne epoxy emulsion as described in claim 5; component B is composed of the following raw materials: waterborne epoxy curing agent and deionized water; the waterborne epoxy anticorrosive coating is obtained by mixing component A and component B at a molar ratio of epoxy equivalent to active hydrogen of 1:1 to 1.2.

[0018] In one embodiment, the waterborne epoxy anticorrosive coating further includes one or more of a defoamer, a leveling agent, a thickener, or a flash rust inhibitor.

[0019] Beneficial effects

[0020] This invention provides a method for preparing hyperbranched polyether epoxy resin and its application in waterborne epoxy anti-corrosion coatings. Based on the proton transfer polymerization mechanism, this invention synthesizes a hyperbranched polyether epoxy resin in a one-pot process under solvent-free and purification-free conditions. The raw materials for this reaction are readily available, the process is simple, the product has a high degree of branching, and the branching structure and epoxy end-group density can be freely controlled.

[0021] The flexible skeleton and branched topology of hyperbranched polyether epoxy resin endow it with low viscosity, which can effectively reduce the viscosity of the emulsion system and prepare waterborne epoxy emulsions with superior performance. The abundant epoxy end groups give the hyperbranched modifier good compatibility with bisphenol A type epoxy resin, and the modifier can increase the crosslinking density of the cured product after curing, making the coating more compact and thus improving the barrier performance of the coating against corrosive media. The low polarity aliphatic flexible segments can not only absorb impact energy and improve the toughness of the cured product, but also improve the hydrophobicity of the coating, and improve the coating's resistance to chemical media and corrosion resistance. Detailed Implementation

[0022] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to specific embodiments. Obviously, the described embodiments are only a part of the embodiments of this invention, and not all of them. Based on the embodiments of this invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this invention.

[0023] The present invention will be further described below with reference to embodiments, including but not limited to the following embodiments.

[0024] Examples 1-15 describe the preparation of hyperbranched polyether epoxy resin. Examples 16-24 describe the preparation of waterborne epoxy emulsions. Examples 25-33 describe the application of hyperbranched polyether epoxy resin in waterborne epoxy anticorrosive coatings.

[0025] The synthetic raw materials involved in this invention can all be obtained through commercial means.

[0026] Comparative Example 1: A method for preparing hyperbranched polyether epoxy resin

[0027] 4.57 g of bisphenol A, 18.16 g of trimethylolpropane triglycidyl ether, and 0.23 g of tetrabutylammonium bromide were weighed and placed in a reactor. Under a nitrogen atmosphere, the reaction was carried out at 160 °C for 12 h. After the reaction was completed, the product was poured onto tin foil and cooled to room temperature to obtain a pale yellow, viscous, transparent liquid, which is the hyperbranched polyether epoxy resin. Its physicochemical properties are shown in Table 1.

[0028] Example 2:

[0029] 4.57 g of bisphenol A, 58.50 g of epoxidized soybean oil, and 0.63 g of tetrabutylammonium bromide were weighed and placed in a reactor. Under a nitrogen atmosphere, the reaction was carried out at 160 °C for 12 h. After the reaction was completed, the product was poured onto tin foil and cooled to room temperature to obtain a pale yellow transparent solid, which is the hyperbranched polyether epoxy resin. Its physicochemical properties are shown in Table 1.

[0030] Example 3

[0031] Based on Example 2, this embodiment changes the reaction time from 12h to 6h, and other conditions are the same as in Example 2. The physicochemical properties of the obtained hyperbranched polyether epoxy resin are shown in Table 1.

[0032] Example 4

[0033] Based on Example 2, this embodiment changes the reaction time from 12h to 24h, and other conditions are as shown in Example 2. The physicochemical properties of the obtained hyperbranched polyether epoxy resin are shown in Table 1.

[0034] Example 5

[0035] Based on Example 2, this embodiment changes the reaction time from 12h to 36h, and other conditions are as shown in Example 2. The physicochemical properties of the obtained hyperbranched polyether epoxy resin are shown in Table 1.

[0036] Example 6

[0037] Based on Example 2, this embodiment changes the reaction temperature from 160℃ to 140℃ and extends the reaction time from 12h to 18h. Other conditions are as shown in Example 2. The physicochemical properties of the obtained hyperbranched polyether epoxy resin are shown in Table 1.

[0038] Example 7

[0039] Based on Example 2, this embodiment changes the reaction temperature from 160℃ to 180℃ and shortens the reaction time from 12h to 6h. Other conditions are as shown in Example 2. The physicochemical properties of the obtained hyperbranched polyether epoxy resin are shown in Table 1.

[0040] Example 8

[0041] This embodiment is based on Example 2, except that bisphenol A is replaced with hydroquinone, and other conditions are the same as in Example 2. The physicochemical properties of the resulting hyperbranched polyether epoxy resin are shown in Table 1.

[0042] Example 9

[0043] This embodiment is based on Example 2, except that bisphenol A is replaced with bisphenol F, and other conditions are the same as in Example 2. The physicochemical properties of the resulting hyperbranched polyether epoxy resin are shown in Table 1.

[0044] Example 10

[0045] This embodiment is based on Example 2, except that tetrabutylammonium bromide is replaced with triphenylphosphine, and other conditions are as shown in Example 2. The physicochemical properties of the resulting hyperbranched polyether epoxy resin are shown in Table 1.

[0046] Example 11

[0047] This embodiment is based on Example 2, except that tetrabutylammonium bromide is replaced with tetrabutylammonium chloride, and other conditions are as shown in Example 2. The physicochemical properties of the resulting hyperbranched polyether epoxy resin are shown in Table 1.

[0048] Example 12

[0049] 4.57g of bisphenol A, 58.50g of epoxidized soybean oil and 0.32g of tetrabutylammonium bromide were weighed and placed in a reactor. Other conditions were as shown in Example 2. The physicochemical properties of the obtained hyperbranched polyether epoxy resin are shown in Table 1.

[0050] Example 13

[0051] 4.57g of bisphenol A, 58.50g of epoxidized soybean oil and 0.95g of tetrabutylammonium bromide were weighed and placed in a reactor. Other conditions were as shown in Example 2. The physicochemical properties of the obtained hyperbranched polyether epoxy resin are shown in Table 1.

[0052] Example 14

[0053] 4.57g of bisphenol A, 19.50g of epoxidized soybean oil and 0.48g of tetrabutylammonium bromide were weighed and placed in a reactor. Other conditions were as shown in Example 2. The physicochemical properties of the obtained hyperbranched polyether epoxy resin are shown in Table 1.

[0054] Example 15

[0055] 4.57g of bisphenol A, 39.00g of epoxidized soybean oil and 0.44g of tetrabutylammonium bromide were weighed and placed in a reactor. Other conditions were as shown in Example 2. The physicochemical properties of the obtained hyperbranched polyether epoxy resin are shown in Table 1.

[0056] Table 1 shows the physicochemical data of the hyperbranched polyether epoxy resins prepared in Comparative Example 1 and Examples 2-15. The number-average molecular weight of the hyperbranched polyether epoxy resins is between 2200 and 4600, which is a moderate molecular weight; the viscosity is basically between 9 and 31 Pa·s, and it is a viscous liquid at room temperature. It has good compatibility with bisphenol A type epoxy resin, and the amount of hyperbranched epoxy resin added can be adjusted according to its application in waterborne epoxy coatings. Among them, the hyperbranched polyether epoxy resin obtained in Comparative Example 1 has a large relative molecular mass and high viscosity, which is not conducive to the preparation of low-viscosity waterborne epoxy emulsions.

[0057] Table 1: Physicochemical properties of hyperbranched polyether epoxy resins

[0058]

[0059]

[0060] Comparative Example 16

[0061] Weigh 3g of Solvay-0092 emulsifier, 20g of bisphenol A epoxy resin, and 1g of ethylene glycol monobutyl ether into a dispersion tank, and heat to 60℃ while stirring. After all components are mixed evenly, increase the stirring speed and slowly add deionized water dropwise at a high-speed shearing speed of 2000rpm. Once the emulsion undergoes an inversion, changing from water-in-oil to oil-in-water, stop adding water and maintain the current high-speed shearing speed for 2 hours. After shearing is complete, reduce the speed to 800rpm and continue adding water for dispersion for 0.5 hours. Adjust the solid content of the emulsion to 55wt%, thus obtaining a stable aqueous epoxy emulsion. The relevant properties of the emulsion are shown in Table 2.

[0062] Comparative Example 17

[0063] In this embodiment, Solvay-0092 emulsifier was replaced with AnquaEM emulsifier, and the rest of the preparation process was the same as in Example 16. The relevant properties of the resulting emulsion are shown in Table 2.

[0064] Comparative Example 18

[0065] In this embodiment, Solvay-0092 emulsifier was replaced with Naxo emulsifier, and the rest of the preparation process was the same as in Example 16. The relevant properties of the resulting emulsion are shown in Table 2.

[0066] Comparative Example 19

[0067] In this embodiment, the shear rate of the emulsion high-speed shearing was reduced from 2000 rpm to 1000 rpm, and the rest of the preparation process was the same as in Example 16. The relevant properties of the resulting emulsion are shown in Table 2.

[0068] Comparative Example 20

[0069] In this embodiment, the shear rate of the emulsion was increased from 2000 rpm to 3000 rpm, and the rest of the preparation process was the same as in Example 16. The relevant properties of the resulting emulsion are shown in Table 2.

[0070] Comparative Example 21

[0071] In this embodiment, 3g of Solvay-0092 emulsifier, 1g of hyperbranched polyether epoxy resin prepared in Comparative Example 1, 19g of bisphenol A type epoxy resin, and 1g of ethylene glycol monobutyl ether were weighed into a dispersion tank, heated to 60°C and stirred. The rest of the preparation process was the same as in Example 16. The relevant properties of the obtained emulsion are shown in Table 2.

[0072] Example 22

[0073] In this embodiment, 3g of Solvay-0092 emulsifier, 1g of hyperbranched polyether epoxy resin prepared in Example 2, 19g of bisphenol A type epoxy resin, and 1g of ethylene glycol monobutyl ether were weighed into a dispersion tank, heated to 60°C and stirred. The rest of the preparation process was the same as in Example 16. The relevant properties of the obtained emulsion are shown in Table 2.

[0074] Example 23

[0075] In this embodiment, 3g of Solvay-0092 emulsifier, 2g of hyperbranched polyether epoxy resin prepared in Example 2, 18g of bisphenol A type epoxy resin, and 1g of ethylene glycol monobutyl ether were weighed into a dispersion tank, heated to 60°C and stirred. The rest of the preparation process was the same as in Example 16. The relevant properties of the resulting emulsion are shown in Table 2.

[0076] Example 24

[0077] In this embodiment, 3g of Solvay-0092 emulsifier, 4g of hyperbranched polyether epoxy resin prepared in Example 2, 16g of bisphenol A type epoxy resin, and 1g of ethylene glycol monobutyl ether were weighed into a dispersion tank, heated to 60°C and stirred. The rest of the preparation process was the same as in Example 16. The relevant properties of the obtained emulsion are shown in Table 2.

[0078] Table 2 shows the relevant performance data of the aqueous epoxy emulsions prepared in Comparative Examples 16-21 and Examples 22-24. It can be seen that the epoxy emulsions prepared with the three commercial emulsifiers and Comparative Example 1 have good stability, with centrifugal stability ≥3000 r / min and storage stability ≥30 days, but the particle size is above 1 μm. Furthermore, when the shear rate is 1000 rpm, the low rotation speed is insufficient to effectively disperse the epoxy latex, leading to increased particle size and decreased stability. When the shear rate is 3000 rpm, there is no significant change in particle size and stability compared to the emulsion prepared at 2000 rpm. When hyperbranched polyether epoxy resin is introduced into the emulsion system, the performance of the emulsion is significantly improved, with particle size reaching the nanometer level, centrifugal stability reaching 5000 r / min, and storage stability reaching 60 days.

[0079] Table 2: Relevant Properties of Waterborne Epoxy Emulsions

[0080]

[0081]

[0082] Comparative Example 25: A method for preparing a waterborne epoxy varnish

[0083] Weigh 50 g of the waterborne epoxy emulsion prepared in Comparative Example 16 as component A. Mix 20 g of waterborne epoxy curing agent Aradur 3986, 65 g of deionized water, 0.1 g of defoamer, 1 g of leveling agent, 0.5 g of thickener, and 0.25 g of flash rust inhibitor evenly as component B. Blend the two components to obtain a coatable waterborne epoxy coating. Apply the coating to a cleaned, sandblasted steel plate using a scraper. Allow it to stand at room temperature until the coating is surface dry, then place it in an oven at 60°C for 8 hours to cure, obtaining the sample for testing. The coating testing method is based on the national standard in Table 3.

[0084] Table 3: Coating Film Performance Test Standards

[0085] thickness Film thickness gauge GB / T13452.2-2008 Adhesion Hundred-grid knife GB / T9286-2021 Pencil hardness Pencil Hardness Tester GB / T6739-2022 flexibility T-bending tester GB / T30791-2014 Impact resistance Paint film impactor GB / T1732-2020 Resistance to neutral salt spray Salt spray chamber ASTMB1117-09 Chemical resistance / GB / T9274-1988

[0086] Comparative Example 26

[0087] Weigh 50 g of the waterborne epoxy emulsion prepared in Comparative Example 16 as component A, and then mix 5 g of waterborne epoxy curing agent Honghui 7013, 0.1 g of defoamer, 1 g of leveling agent, 0.5 g of thickener and 0.25 g of anti-flash rust agent evenly as component B. After mixing the two, a coatable waterborne epoxy coating is obtained, and then the coating is prepared according to the preparation method of Example 25.

[0088] Comparative Example 27

[0089] Weigh 50 g of the waterborne epoxy emulsion prepared in Comparative Example 16 as component A, and then mix 9 g of waterborne epoxy curing agent YNCA701, 0.1 g of defoamer, 1 g of leveling agent, 0.5 g of thickener and 0.25 g of anti-flash rust agent evenly as component B. After mixing the two, a coatable waterborne epoxy coating is obtained, and then the coating is prepared according to the preparation method of Example 25.

[0090] Comparative Example 28

[0091] Weigh 55 g of the waterborne epoxy emulsion prepared in Comparative Example 16 as component A, and then mix 20 g of waterborne epoxy curing agent Aradur3986, 0.1 g of defoamer, 1 g of leveling agent, 0.5 g of thickener and 0.25 g of anti-flash rust agent evenly as component B. After mixing the two, a coatable waterborne epoxy coating is obtained, and then the coating is prepared according to the preparation method of Example 25.

[0092] Comparative Example 29

[0093] Weigh 60g of the waterborne epoxy emulsion prepared in Comparative Example 16 as component A, and then mix 20g of waterborne epoxy curing agent Aradur3986, 0.1g of defoamer, 1g of leveling agent, 0.5g of thickener and 0.25g of anti-flash rust agent evenly as component B. After mixing the two, a coatable waterborne epoxy coating is obtained, and then the coating is prepared according to the preparation method of Example 25.

[0094] Comparative Example 30

[0095] Weigh 50g of the waterborne epoxy emulsion prepared in Comparative Example 21 as component A, and then mix 20g of waterborne epoxy curing agent Aradur3986, 0.1g of defoamer, 1g of leveling agent, 0.5g of thickener and 0.25g of anti-flash rust agent evenly as component B. After mixing the two, a coatable waterborne epoxy coating is obtained, and then the coating is prepared according to the preparation method of Example 25.

[0096] Example 31

[0097] Weigh 50g of the waterborne epoxy emulsion prepared in Example 22 as component A, and then mix 20g of waterborne epoxy curing agent Aradur3986, 0.1g of defoamer, 1g of leveling agent, 0.5g of thickener and 0.25g of anti-flash rust agent evenly as component B. After mixing the two, a coatable waterborne epoxy coating is obtained, and then the coating is prepared according to the preparation method of Example 25.

[0098] Example 32

[0099] Weigh 50g of the waterborne epoxy emulsion prepared in Example 23 as component A, and then mix 20g of waterborne epoxy curing agent Aradur3986, 0.1g of defoamer, 1g of leveling agent, 0.5g of thickener and 0.25g of anti-flash rust agent evenly as component B. After mixing the two, a coatable waterborne epoxy coating is obtained, and then the coating is prepared according to the preparation method of Example 25.

[0100] Example 33

[0101] Weigh 50g of the waterborne epoxy emulsion prepared in Example 24 as component A, and then mix 20g of waterborne epoxy curing agent Aradur3986, 0.1g of defoamer, 1g of leveling agent, 0.5g of thickener and 0.25g of anti-flash rust agent evenly as component B. After mixing the two, a coatable waterborne epoxy coating is obtained, and then the coating is prepared according to the preparation method of Example 25.

[0102] The basic properties, media resistance, and neutral salt spray resistance of the coatings prepared in Comparative Examples 25-30 and Examples 31-33 are shown in Tables 4 and 5. It can be seen that the coatings prepared from the epoxy emulsions of Comparative Examples 25-30 have good adhesion (all rated 0) and good pencil hardness, but poor flexibility, with an impact strength ≤60cm. The coatings also exhibit poor resistance to chemical media and neutral salt spray.

[0103] The flexibility and impact strength of the coatings in Examples 31-33 were significantly improved compared to Comparative Examples 25-30, with flexibility increasing from 1T to 0T and impact strength increasing from 60cm to 100cm. The alkali resistance, acid resistance, water resistance, salt water resistance, and salt spray resistance of the coatings in Examples 31-33 were also significantly improved compared to Comparative Examples 25-30.

[0104] Table 4: Basic Properties of the Coating

[0105]

[0106] Table 5: Resistance to chemical media and resistance to neutral salt spray of the coating (unit: hours)

[0107]

[0108] Although the present invention has been disclosed above with reference to preferred embodiments, it is not intended to limit the present invention. Anyone skilled in the art can make various modifications and alterations without departing from the spirit and scope of the present invention. Therefore, the scope of protection of the present invention should be determined by the claims.

Claims

1. A method for preparing a low-viscosity hyperbranched polyether epoxy resin for improving the properties of waterborne epoxy emulsions, characterized in that, Diphenol, multifunctional epoxide and catalyst were added to the reactor, and a nitrogen atmosphere was maintained. The reaction temperature was 140-180℃ and the reaction time was 6-36h. Through a one-step proton transfer polymerization reaction, hyperbranched polyether epoxy resin with a viscosity of 9-31 Pa·s at 25℃ was obtained. The multifunctional epoxide is epoxidized soybean oil; The diphenol is one or more of hydroquinone, resorcinol, bisphenol A, and bisphenol F; The molar ratio of diphenol to polyfunctional epoxide is 1:1.0 to 1:3.0; The catalyst is one or more selected from tetrabutylammonium chloride, tetrabutylammonium bromide, tetrabutylammonium hydroxide, ethyltriphenylphosphine chloride, ethyltriphenylphosphine bromide, triphenylphosphine, and boron trifluoride ether. The catalyst addition amount is 0.5 wt% to 2.0 wt% of the total mass of the diphenol and the polyfunctional epoxide; The aqueous epoxy emulsion prepared based on the hyperbranched polyether epoxy resin has a particle size ≤950 nm.

2. The hyperbranched polyether epoxy resin prepared by the preparation method according to claim 1.

3. The hyperbranched polyether epoxy resin according to claim 2, characterized in that, The number average molecular weight of the hyperbranched polyether epoxy resin is between 2200 and 4600.

4. A hyperbranched polyether epoxy resin modified waterborne epoxy emulsion, characterized in that, Contains the low-viscosity hyperbranched polyether epoxy resin as described in any one of claims 2-3.

5. The method for preparing the hyperbranched polyether epoxy resin modified waterborne epoxy emulsion as described in claim 4, characterized in that, Weigh 10-20 parts of waterborne epoxy emulsifier, 60-110 parts of bisphenol A type epoxy resin, 1-15 parts of the above hyperbranched polyether epoxy resin, and 0-10 parts of organic solvent. Heat to 60°C and stir. Under high-speed shearing at 1000-3000 rpm, add deionized water dropwise. After the emulsion undergoes an inversion, changing from water-in-oil to oil-in-water, stop adding water and maintain the current high-speed shearing for 2 hours. After shearing is complete, reduce the speed to 800 rpm and continue adding water to disperse for 0.5 hours. Adjust the solid content of the emulsion to 55 wt% to obtain the hyperbranched polyether epoxy resin modified waterborne epoxy emulsion.

6. The method for preparing the hyperbranched polyether epoxy resin modified waterborne epoxy emulsion according to claim 5, characterized in that, The organic solvent is one or more of ethylene glycol monobutyl ether, ethylene glycol dimethyl ether, propylene glycol monobutyl ether, and propylene glycol dimethyl ether.

7. The application of the hyperbranched polyether epoxy resin modified waterborne epoxy emulsion according to claim 4 in waterborne epoxy anticorrosive coatings.

8. The application according to claim 7, characterized in that, The waterborne epoxy anticorrosive coating comprises, by mass, component A and component B; component A is the hyperbranched polyether epoxy resin modified waterborne epoxy emulsion as described in claim 4; component B is composed of the following raw materials: waterborne epoxy curing agent and deionized water; the waterborne epoxy anticorrosive coating is obtained by mixing component A and component B at a molar ratio of epoxy equivalent to active hydrogen of 1:1 to 1.2.

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