Synthesis of low-viscosity hyperbranched polyether epoxy resin and application of low-viscosity hyperbranched polyether epoxy resin in waterborne epoxy anticorrosive paint

Abstract

The invention discloses a preparation method of low-viscosity hyperbranched polyether epoxy resin and application of the low-viscosity hyperbranched polyether epoxy resin in waterborne epoxy anticorrosive paint, and belongs to the technical field of paint. The preparation method of the hyperbranched polyether epoxy resin is based on a proton transfer polymerization mechanism, and the hyperbranched polyether epoxy resin is prepared by using a synthesis strategy of A2 + B3. The hyperbranched polyether epoxy resin prepared by the invention can effectively reduce the viscosity of an emulsification system, improve the stability of an epoxy emulsion and reduce the particle size of the emulsion, and can also be used for modifying a waterborne epoxy anticorrosive coating, and a cured coating has excellent toughness, chemical medium resistance and salt spray resistance.

Description

Technical Field

[0001] The invention relates to a preparation method of a hyperbranched polyether epoxy resin and application of the same in a waterborne epoxy anticorrosive coating, belonging to the technical field of anticorrosive coatings. Background Art

[0002] Water-based coatings use water instead of organic solvents as a dispersion medium. The process is simple and safe, and the construction cost is low. It is a popular direction for the green development of epoxy coatings. However, in the process of water-based epoxy resin, the introduction of emulsifiers or hydrophilic groups is inevitable. These hydrophilic segments will remain in the cross-linked network after the coating is cured. In addition, the film-forming mechanism of water-based epoxy coatings has also changed, which makes the coating prone to defects and pores during the curing process. These reasons make the mechanical properties and anti-corrosion properties of water-based epoxy coatings inferior to those of solvent-based epoxy coatings. Therefore, reducing the defects and pores of the coating and improving the flexibility and density of the coating are the key to promoting the further development of water-based epoxy coatings and replacing solvent-based epoxy coatings.

[0003] In recent years, hyperbranched epoxy resins (EHBPs) have been widely used in modified epoxy resins due to their advantages of low viscosity, high compatibility and rich terminal epoxy groups. Through reasonable structural design, hyperbranched epoxy resins can achieve comprehensive improvement in the mechanical properties and anti-corrosion properties of epoxy coatings. However, most of the current research on epoxy coating modification is carried out in a homogeneous system, and the coating contains a lot of organic solvents, which does not conform to the development trend of low-VOC coatings. Patent CN201610345144.X reports a polyether hyperbranched polymer synthesized with hydroquinone as A2 monomer and multifunctional glycidyl ether as B3 monomer and used to prepare solvent-based epoxy resin anti-corrosion coatings, and the toughness and anti-corrosion properties of the prepared coatings have been improved.

[0004] At present, there are still few studies on waterborne epoxy coatings modified by hyperbranched epoxy resins at home and abroad. Li Xiaoyu's research group synthesized several hyperbranched polyether epoxy resins through dihydric phenol and trifunctional epoxy and used them to modify waterborne epoxy coatings. However, the preparation cost of these hyperbranched polyether epoxy resins is high, and there are many polar groups in the structure and the viscosity is high, which is not conducive to the preparation of waterborne epoxy coatings and its anti-corrosion performance. Summary of the invention

[0005] In order to solve the above problems, the present invention provides a method for preparing a low-viscosity hyperbranched polyether epoxy resin and its application in waterborne epoxy anticorrosive coatings. The present invention is based on the proton transfer polymerization mechanism, and synthesizes a hyperbranched polyether epoxy resin by a one-pot method under solvent-free and purification-free conditions. The obtained resin is blended with a bisphenol A-type epoxy resin, and the blended resin is emulsified using a commercial waterborne epoxy emulsifier to achieve the modification of the waterborne epoxy emulsion by the hyperbranched polyether epoxy resin, and the modified waterborne epoxy emulsion is compounded with a waterborne epoxy curing agent to prepare a waterborne epoxy anticorrosive coating, and the coating has excellent toughness, chemical resistance and corrosion resistance.

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

[0007] The multifunctional epoxide is epoxidized soybean oil;

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

[0009] The molar ratio of the dihydric phenol to the polyfunctional epoxy compound is 1:1.0 to 1:3.0.

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

[0011] In one embodiment, the amount of catalyst added is 0.5 wt % to 2.0 wt % of the total mass of the dihydric phenol and the multifunctional epoxy compound.

[0012] The second object of the present invention is to provide a hyperbranched polyether epoxy resin prepared according to the above method.

[0013] The third object of the present invention is to provide a hyperbranched polyether epoxy resin modified aqueous epoxy emulsion, which contains the low-viscosity hyperbranched polyether epoxy resin prepared by the above preparation method, or the above low-viscosity hyperbranched polyether epoxy resin.

[0014] In one embodiment, 10 to 20 parts of an aqueous epoxy emulsifier, 60 to 110 parts of a bisphenol A epoxy resin, 1 to 15 parts of the above-mentioned hyperbranched polyether epoxy resin, and 0 to 10 parts of an organic solvent are weighed, the temperature is raised to 60° C. with stirring, and deionized water is added dropwise at a high-speed shear of 1000 to 3000 rpm. After the emulsion undergoes a phase inversion from oil-in-water to water-in-oil, the addition of water is stopped, and the current speed is maintained for high-speed shearing for 2 hours; after the shearing is completed, the speed is reduced to 800 rpm, and water is continued to be added for dispersion for 0.5 hours, and the solid content of the emulsion is adjusted to 55 wt %, so as to obtain a hyperbranched polyether epoxy resin modified aqueous 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 object of the present invention is to provide an application of the low-viscosity hyperbranched polyether epoxy resin in a water-based epoxy anti-corrosion coating.

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

[0018] In one embodiment, the waterborne epoxy anti-corrosion coating further comprises one or more of a defoamer, a leveling agent, a thickener or an anti-flash rust agent.

[0019] Beneficial Effects

[0020] The present invention provides a method for preparing a hyperbranched polyether epoxy resin and its application in a waterborne epoxy anticorrosive coating. Based on the proton transfer polymerization mechanism, the present invention synthesizes a hyperbranched polyether epoxy resin by a one-pot method in the absence of solvent and purification. The raw materials for the reaction synthesis 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 topological structure of the hyperbranched polyether epoxy resin give it the characteristics of low viscosity, which can effectively reduce the viscosity of the emulsification system and prepare a water-based epoxy emulsion with better performance; the rich epoxy end groups give the hyperbranched modifier good compatibility with bisphenol A epoxy resin, and the modifier can increase the cross-linking density of the cured product after participating in the curing, making the coating denser, thereby improving the barrier performance of the coating to corrosive media; the low-polarity fat flexible chain segment 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 chemical resistance and corrosion resistance of the coating. DETAILED DESCRIPTION

[0022] In order to make the purpose, technical scheme and advantages of the present invention clearer, the present invention will be further described in detail below in conjunction with specific embodiments. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0023] The present invention is further described below in conjunction with the embodiments, and the present invention includes but is not limited to the following embodiments.

[0024] Examples 1 to 15 are the preparation of hyperbranched polyether epoxy resins, Examples 16 to 24 are the preparation of waterborne epoxy emulsions, and Examples 25 to 33 are the application of hyperbranched polyether epoxy resins in waterborne epoxy anticorrosive coatings.

[0025] The synthetic raw materials involved in the present invention can all be obtained from commercial channels.

[0026] Comparative Example 1: A method for preparing a 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, and reacted at 160°C for 12 h under nitrogen atmosphere. After the reaction was completed, the product was poured onto tin foil and cooled to room temperature to obtain a light yellow viscous transparent liquid, which was a hyperbranched polyether epoxy resin. Its physical and chemical properties are shown in Table 1.

[0028] Embodiment 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, and reacted at 160°C for 12 h under nitrogen atmosphere. After the reaction was completed, the product was poured onto tin foil and cooled to room temperature to obtain a light yellow transparent solid, which was a hyperbranched polyether epoxy resin. Its physical and chemical properties are shown in Table 1.

[0030] Example 3

[0031] In this example, based on Example 2, the reaction time was changed from 12 h to 6 h, and the other conditions were the same as those in Example 2. The physical and chemical properties of the obtained hyperbranched polyether epoxy resin are shown in Table 1.

[0032] Example 4

[0033] In this example, based on Example 2, the reaction time was changed from 12 h to 24 h, and the other conditions were the same as those in Example 2. The physical and chemical properties of the obtained hyperbranched polyether epoxy resin are shown in Table 1.

[0034] Example 5

[0035] In this example, based on Example 2, the reaction time was changed from 12 h to 36 h, and the other conditions were the same as those in Example 2. The physical and chemical properties of the obtained hyperbranched polyether epoxy resin are shown in Table 1.

[0036] Example 6

[0037] In this example, based on Example 2, the reaction temperature was changed from 160° C. to 140° C., the reaction time was extended from 12 h to 18 h, and the other conditions were the same as those in Example 2. The physical and chemical properties of the obtained hyperbranched polyether epoxy resin are shown in Table 1.

[0038] Example 7

[0039] In this example, based on Example 2, the reaction temperature was changed from 160° C. to 180° C., the reaction time was shortened from 12 h to 6 h, and the other conditions were the same as those in Example 2. The physical and chemical properties of the obtained hyperbranched polyether epoxy resin are shown in Table 1.

[0040] Example 8

[0041] In this example, based on Example 2, bisphenol A is replaced by hydroquinone, and other conditions are the same as those in Example 2. The physical and chemical properties of the obtained hyperbranched polyether epoxy resin are shown in Table 1.

[0042] Example 9

[0043] In this example, on the basis of Example 2, bisphenol A is replaced by bisphenol F, and other conditions are the same as those in Example 2. The physical and chemical properties of the obtained hyperbranched polyether epoxy resin are shown in Table 1.

[0044] Example 10

[0045] In this example, based on Example 2, tetrabutylammonium bromide is replaced by triphenylphosphine, and other conditions are the same as those in Example 2. The physical and chemical properties of the obtained hyperbranched polyether epoxy resin are shown in Table 1.

[0046] Embodiment 11

[0047] In this example, based on Example 2, tetrabutylammonium bromide is replaced by tetrabutylammonium chloride, and other conditions are the same as those in Example 2. The physical and chemical properties of the obtained hyperbranched polyether epoxy resin are shown in Table 1.

[0048] Example 12

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

[0050] Example 13

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

[0052] Embodiment 14

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

[0054] Embodiment 15

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

[0056] Table 1 shows the physical and chemical data of the hyperbranched polyether epoxy resin prepared in Comparative Example 1 and Examples 2 to 15. The number average molecular weight of the hyperbranched polyether epoxy resin is between 2200 and 4600, which has 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 epoxy resin, and the addition amount of the hyperbranched polyether epoxy resin can be adjusted according to the application in the water-based epoxy coating. 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 water-based epoxy emulsion.

[0057] Table 1: Physical and chemical 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, heat to 60°C and stir. After all components are evenly mixed, increase the stirring rate, and slowly add deionized water at a high shear rate of 2000rpm. After the emulsion undergoes a phase reversal from oil-in-water to water-in-oil, stop adding water, and maintain the current speed for high-speed shearing for 2h. After the shearing is completed, reduce the speed to 800rpm, continue to add water to disperse for 0.5h, and adjust the solid content of the emulsion to 55wt%, thus obtaining a stable water-based epoxy emulsion. The relevant properties of the emulsion are shown in Table 2.

[0062] Comparative Example 17

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

[0064] Comparative Example 18

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

[0066] Comparative Example 19

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

[0068] Comparative Example 20

[0069] In this example, the shear rate of the high-speed shearing of the emulsion is increased from 2000 rpm to 3000 rpm. The rest of the preparation process is the same as that of Example 16. The relevant properties of the obtained emulsion are shown in Table 2.

[0070] Comparative Example 21

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

[0072] Embodiment 22

[0073] In this example, 3 g of Solvay-0092 emulsifier, 1 g of the hyperbranched polyether epoxy resin prepared in Example 2, 19 g of bisphenol A epoxy resin, and 1 g of ethylene glycol monobutyl ether were weighed into a dispersion tank, and the temperature was raised to 60° C. with stirring. 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] Embodiment 23

[0075] In this example, 3 g of Solvay-0092 emulsifier, 2 g of the hyperbranched polyether epoxy resin prepared in Example 2, 18 g of bisphenol A epoxy resin, and 1 g of ethylene glycol monobutyl ether were weighed into a dispersion tank, the temperature was raised 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.

[0076] Embodiment 24

[0077] In this example, 3 g of Solvay-0092 emulsifier, 4 g of the hyperbranched polyether epoxy resin prepared in Example 2, 16 g of bisphenol A epoxy resin, and 1 g of ethylene glycol monobutyl ether were weighed into a dispersion tank, the temperature was raised 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 emulsion prepared by Comparative Examples 16 to 21 and Examples 22 to 24. It can be seen that the epoxy emulsion prepared by the three commercial emulsifiers and Comparative Example 1 has good stability, centrifugal stability is ≥3000r / min, storage stability is ≥30 days, but the particle size is above 1μm. In addition, when the shear rate is 1000rpm, the lower speed is not enough to disperse the epoxy latex well, the particle size of the emulsion increases, and the stability decreases. When the shear rate is 3000rpm, compared with the emulsion prepared under 2000rpm conditions, the particle size and stability of the emulsion do not change significantly. After the hyperbranched polyether epoxy resin is introduced into the emulsification system, the performance of the emulsion is significantly improved, the particle size reaches nanometer level, the centrifugal stability reaches 5000r / min, and the storage stability reaches 60 days.

[0079] Table 2: Relevant properties of waterborne epoxy emulsion

[0080]

[0081]

[0082] Comparative Example 25 Preparation method of a water-based epoxy varnish

[0083] Weigh 50 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, 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 anti-flash rust agent as component B, blend the two to obtain a waterborne epoxy coating that can be applied, use a scraper to apply the coating on a cleaned sandblasted steel plate, let it stand at room temperature, and after the coating is dry, place it in an oven at 60°C for 8 h to obtain a test sample. The coating test method is carried out according to the national standard in Table 3.

[0084] Table 3: Paint film performance test standards

[0085] Paint film properties instrument National Standard thickness Film Thickness Tester GB / T13452.2-2008 Adhesion 100-grid knife GB / T9286-2021 Pencil hardness Pencil Hardness Tester GB / T6739-2022 Flexibility T-type bending testing machine GB / T30791-2014 Impact resistance Paint film impactor GB / T1732-2020 Neutral salt spray resistance Salt spray chamber ASTMB1117-09 Chemical resistance / GB / T9274-1988

[0086] Comparative Example 26

[0087] Weigh 50 g of the water-based epoxy emulsion prepared in Comparative Example 16 as component A, and then mix 5 g of water-based epoxy curing agent Honghui 7013, 0.1 g of defoaming agent, 1 g of leveling agent, 0.5 g of thickener and 0.25 g of anti-flash rust agent as component B, blend the two to obtain a coatable water-based epoxy coating, and then prepare a coating according to the preparation method of Example 25.

[0088] Comparative Example 27

[0089] Weigh 50 g of the water-based epoxy emulsion prepared in Comparative Example 16 as component A, and then mix 9 g of water-based epoxy curing agent YNCA701, 0.1 g of defoaming agent, 1 g of leveling agent, 0.5 g of thickener and 0.25 g of anti-flash rust agent as component B, blend the two to obtain a coatable water-based epoxy coating, and then prepare a coating according to the preparation method of Example 25.

[0090] Comparative Example 28

[0091] Weigh 55 g of the water-based epoxy emulsion prepared in Comparative Example 16 as component A, and then mix 20 g of water-based epoxy curing agent Aradur3986, 0.1 g of defoaming agent, 1 g of leveling agent, 0.5 g of thickener and 0.25 g of anti-flash rust agent as component B, blend the two to obtain a coatable water-based epoxy coating, and then prepare a coating according to the preparation method of Example 25.

[0092] Comparative Example 29

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

[0094] Comparative Example 30

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

[0096] Embodiment 31

[0097] Weigh 50g of the water-based epoxy emulsion prepared in Example 22 as component A, and then mix 20g of water-based epoxy curing agent Aradur3986, 0.1g of defoaming agent, 1g of leveling agent, 0.5g of thickener and 0.25g of anti-flash rust agent as component B, blend the two to obtain a coatable water-based epoxy coating, and then prepare a coating according to the preparation method of Example 25.

[0098] Embodiment 32

[0099] Weigh 50g of the water-based epoxy emulsion prepared in Example 23 as component A, and then mix 20g of water-based epoxy curing agent Aradur3986, 0.1g of defoaming agent, 1g of leveling agent, 0.5g of thickener and 0.25g of anti-flash rust agent as component B, blend the two to obtain a coatable water-based epoxy coating, and then prepare a coating according to the preparation method of Example 25.

[0100] Embodiment 33

[0101] Weigh 50g of the water-based epoxy emulsion prepared in Example 24 as component A, and then mix 20g of water-based epoxy curing agent Aradur3986, 0.1g of defoaming agent, 1g of leveling agent, 0.5g of thickener and 0.25g of anti-flash rust agent as component B, blend the two to obtain a coatable water-based epoxy coating, and then prepare a coating according to the preparation method of Example 25.

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

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

[0104] Table 4: Basic properties of coatings

[0105]

[0106] Table 5: Chemical resistance and neutral salt spray resistance of coatings (unit: hours)

[0107]

[0108] Although the present invention has been disclosed as above in the form of a preferred embodiment, it is not intended to limit the present invention. Anyone familiar with this technology can make various changes and modifications without departing from the spirit and scope of the present invention. Therefore, the scope of protection of the present invention should be based on the definition of the claims.

Claims

1. A method for preparing a low-viscosity hyperbranched polyether epoxy resin, characterized in that: Add dihydric phenol, polyfunctional epoxy compound and catalyst into a reactor, maintain nitrogen atmosphere, react at 140-180°C, react for 6-36h, and obtain hyperbranched polyether epoxy resin; The multifunctional epoxide is epoxidized soybean oil; The dihydric phenol is one or more of hydroquinone, resorcinol, bisphenol A and bisphenol F; The molar ratio of the dihydric phenol to the polyfunctional epoxy compound is 1:1.0 to 1:3.

0.

2. A method for preparing a low-viscosity hyperbranched polyether epoxy resin according to claim 1, characterized in that: The catalyst is one or more of tetrabutylammonium chloride, tetrabutylammonium bromide, tetrabutylammonium hydroxide, ethyltriphenylphosphine chloride, ethyltriphenylphosphine bromide, triphenylphosphine, and boron trifluoride etherate.

3. A method for preparing a low-viscosity hyperbranched polyether epoxy resin according to claim 1, characterized in that: The amount of catalyst added is 0.5wt% to 2.0wt% of the total mass of the dihydric phenol and the multifunctional epoxy compound.

4. The hyperbranched polyether epoxy resin prepared by the preparation method according to any one of claims 1 to 3.

5. A hyperbranched polyether epoxy resin modified waterborne epoxy emulsion, characterized in that: The invention comprises a low-viscosity hyperbranched polyether epoxy resin prepared by the preparation method according to any one of claims 1 to 3, or a low-viscosity hyperbranched polyether epoxy resin according to claim 4.

6. The method for preparing a hyperbranched polyether epoxy resin modified aqueous epoxy emulsion according to claim 5, characterized in that: Weigh 10-20 parts of water-based epoxy emulsifier, 60-110 parts of bisphenol A epoxy resin, 1-15 parts of the above-mentioned hyperbranched polyether epoxy resin, and 0-10 parts of organic solvent, heat to 60°C and stir, add deionized water dropwise under high-speed shearing at 1000-3000rpm, stop adding water after the emulsion undergoes phase inversion from oil-in-water to water-in-oil, maintain the current speed and high-speed shearing for 2h; after the shearing is completed, reduce the speed to 800rpm, continue to add water and disperse for 0.5h, adjust the solid content of the emulsion to 55wt%, and obtain a water-based epoxy emulsion modified with a hyperbranched polyether epoxy resin.

7. The method for preparing a hyperbranched polyether epoxy resin modified aqueous epoxy emulsion according to claim 6, 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.

8. Use of the hyperbranched polyether epoxy resin modified waterborne epoxy emulsion according to claim 5 in waterborne epoxy anticorrosive coatings.

9. The use according to claim 8, characterized in that: The waterborne epoxy anti-corrosion coating comprises component A and component B in parts by mass; 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 anti-corrosion coating is obtained by mixing component A and component B at a molar ratio of epoxy equivalent: active hydrogen of 1:1 to 1.

2.

10. The use according to claim 8, characterized in that: The waterborne epoxy anticorrosive coating also includes one or more of a defoamer, a leveling agent, a thickener or an anti-flash rust agent.

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