An aqueous epoxy curing agent, its preparation method and an aqueous epoxy coating

Abstract

An embodiment of the present application provides an aqueous epoxy curing agent, a preparation method thereof, and an aqueous epoxy coating, relating to the technical field of coatings. The aqueous epoxy curing agent contains a compound, and the compound is to introduce a polyether chain segment and a bisphenol A chain segment at the primary amine position of the R group in the phenolic epoxy resin modified amine. The aqueous epoxy coating includes an aqueous epoxy emulsion and the above-mentioned aqueous epoxy curing agent. The aqueous epoxy coating formed by the aqueous epoxy curing agent has good water dilutability, and the obtained coating film has excellent mechanical properties, water resistance, and corrosion resistance.

Description

Technical Field

[0001] The present application relates to the field of coating technology, and in particular to a waterborne epoxy curing agent and a preparation method thereof, and a waterborne epoxy coating. Background Art

[0002] Phenolic epoxy resin is usually obtained by epoxidizing thermoplastic linear low molecular weight phenolic resin with epichlorohydrin under the action of a catalyst. Phenolic epoxy resin is a kind of multifunctional epoxy resin. Phenolic epoxy resin is used as an epoxy resin curing agent, especially in coatings. The obtained coating film has excellent hardness, heat resistance and corrosion resistance. At present, the coating formed by phenolic epoxy resin has been widely used as food can coating, high-performance primer, wire insulation paint, etc.

[0003] Currently, most of the new waterborne epoxy curing agents on the market are developed by modifying multifunctional phenolic epoxy resins to obtain waterborne epoxy resins with lower molecular weight. However, many waterborne epoxy curing agents have average water dilution, and the mechanical properties and resistance of the coating films obtained by using them in waterborne epoxy coatings are not ideal. Therefore, there is an urgent need for waterborne epoxy curing agents with good performance. Summary of the invention

[0004] The purpose of the embodiments of the present application is to provide a water-based epoxy curing agent and a preparation method thereof and a water-based epoxy coating. The coating has good water dilution properties and the resulting coating film has excellent mechanical properties, water resistance and corrosion resistance.

[0005] In a first aspect, an embodiment of the present application provides a water-based epoxy curing agent, which comprises a compound, wherein the compound is a polyether segment and a bisphenol A segment introduced into the primary amine position of the R group in the phenolic epoxy resin modified amine, and the structural formula of the phenolic epoxy resin modified amine is:

[0006] R is:

[0007] In the above technical scheme, the water-based epoxy curing agent is to introduce a hydrophilic polyether segment and an oleophilic bisphenol A segment at the primary amine position of the phenolic epoxy resin modified amine. The curing agent has the structural characteristics of the phenolic epoxy resin modified amine, and the structural curing agent has good compatibility with the epoxy resin emulsion and a wide range of applications; the phenolic epoxy resin modification can reduce the volatility, irritation and toxicity of the amine; the phenolic skeleton is introduced on the basis of the polyamine structure, and the curing agent formed can improve the heat resistance of the cured product, and the introduction of phenolic hydroxyl groups can improve the reaction activity of the cured product, and is suitable for curing under low temperature, normal temperature and humid environmental conditions. The introduction of polyether segments and bisphenol A segments at the primary amine position of the phenolic epoxy resin modified amine can increase the molecular weight and amine active hydrogen equivalent of the phenolic epoxy resin modified amine, the water dilutability of the formed curing agent is good, and the curing period with the epoxy resin emulsion is long, and the mechanical properties and resistance (water resistance and corrosion resistance) of the cured film will also be greatly improved.

[0008] In the second aspect, an embodiment of the present application provides a method for preparing the water-based epoxy curing agent provided in the first aspect, which mainly involves end-capping a phenolic epoxy resin modified amine solution with a water-based epoxy resin and an oily epoxy resin; wherein the phenolic epoxy resin modified amine solution contains a phenolic epoxy resin modified amine; the water-based epoxy resin has a polyether segment; and the oily epoxy resin has a bisphenol A segment.

[0009] In the above technical scheme, an organic fatty amine (R) is used as a modification object, and a water-based epoxy curing agent with good water dilution is prepared by an epoxy-polyamine addition method, and a hydrophobic epoxy resin and a hydrophilic nonionic segment are introduced into the polyamine. The water-based epoxy curing agent is easily mixed with a water-based epoxy emulsion, has a long activation period, and the prepared coating has excellent mechanical properties, water resistance and good corrosion resistance.

[0010] Specifically, organic fatty amines can provide active hydrogen sites, and the molecular structure of the reaction product contains phenolic hydroxyl groups and amino groups (-NH 2 ) and secondary amino groups (-NH-), which enable this type of curing agent to promote the reaction and accelerate the curing of the resin, and can be cured at low temperatures, in humidity or underwater; on the other hand, this straight-chain fatty amine-modified curing agent greatly improves flexibility and bonding workability, and greatly improves mechanical properties.

[0011] In a possible implementation, the waterborne epoxy resin includes at least one of polyethylene glycol diglycidyl ether, polypropylene glycol diglycidyl ether, and polybutylene glycol diglycidyl ether.

[0012] In the above technical solution, the waterborne epoxy resin has a polyether segment and can react with the phenolic epoxy resin modified amine to introduce the polyether segment into a specific position of the phenolic epoxy resin modified amine.

[0013] In a possible implementation, the oil-based epoxy resin is one of E-44 epoxy resin, E-20 epoxy resin, and E-51 epoxy resin.

[0014] In the above technical solution, the oil-based epoxy resin has a bisphenol A segment and can react with the phenolic epoxy resin modified amine to introduce a bisphenol A segment at a specific position of the phenolic epoxy resin modified amine.

[0015] In a possible implementation, the solid content of the phenolic epoxy resin modified amine solution is 50-80%, and the dosage ratio of the phenolic epoxy resin modified amine solution, the water-based epoxy resin, and the oil-based epoxy resin is 40:2-6:2-9.

[0016] In the above technical solution, using a phenolic epoxy resin modified amine solution with a certain solid content facilitates further improvement of the phenolic epoxy resin modified amine.

[0017] In a possible implementation, the capping reaction mainly involves stirring the water-based epoxy resin and the oil-based epoxy resin evenly, then adding them to the phenolic epoxy resin modified amine solution, controlling the temperature at 55-65°C during the addition, and keeping warm for 2-4 hours after the addition to obtain a water-based epoxy curing agent.

[0018] In a possible implementation, the phenolic epoxy resin modified amine solution is mainly obtained by reacting 30 parts of phenolic epoxy resin, 25-35 parts of organic fatty amine, and 25-35 parts of solvent by mass.

[0019] In a possible implementation, the preparation method of the phenolic epoxy resin modified amine solution includes the following steps:

[0020] Mix the organic fatty amine and part of the solvent evenly to obtain a dissolved solution, then add the solution prepared from the phenolic epoxy resin and the remaining solvent to the dissolved solution, control the temperature at 55-65°C during the addition, keep warm for 3-4 hours after the addition, and adjust the solid content to 50-80% to obtain the phenolic epoxy resin modified amine solution.

[0021] In a possible implementation, the organic fatty amine includes at least one of ethylenediamine, hexamethylenediamine, diethylenetriamine, tetraethylenepentamine, and polyethylenepolyamine.

[0022] In a third aspect, an embodiment of the present application provides a water-based epoxy coating, which includes a water-based epoxy emulsion and the water-based epoxy curing agent provided in the first aspect. Specific embodiments

[0023] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the technical solutions in the embodiments of this application will be clearly and completely described below. For those not specified in the embodiments, conventional conditions or conditions recommended by the manufacturer are applied. For reagents or instruments without indicating the manufacturer, they are all conventional products that can be obtained through commercial purchase.

[0024] The waterborne epoxy curing agent, its preparation method, and the waterborne epoxy coating in the embodiments of this application will be specifically described below.

[0025] The embodiments of this application provide a waterborne epoxy curing agent, which contains a compound. The compound is obtained by introducing a polyether segment and a bisphenol A segment at the primary amine position of the R group in the phenolic epoxy resin modified amine. The structural formula of the phenolic epoxy resin modified amine is:

[0026] R is:

[0027] It should be noted that the R groups at different positions in the phenolic epoxy resin modified amine can be the same or different; the polyether segment and the bisphenol A segment can be introduced at the R group at any position (such as the two ends or the middle); based on the phenolic epoxy resin modified amine, some R groups have the polyether segment and the bisphenol A segment introduced, while some R groups remain unchanged.

[0028] The polyether segment generally refers to the segment after the reaction of waterborne epoxy resin with primary amine.

[0029] An example of the structural formula of the waterborne epoxy curing agent is as follows.

[0030] For example, for the phenolic epoxy resin modified amine being and R being The structural formula of the compound after introducing the polyether segment and the bisphenol A segment at certain positions is

[0031] R' is

[0032] For the R in the phenolic epoxy resin modified amine being The structural formula of the compound after introducing the polyether segment and the bisphenol A segment at certain positions is R' is

[0033]

[0034] For the R in the phenolic epoxy resin modified amine being The structural formula of the compound after introducing the polyether segment and the bisphenol A segment at certain positions is

[0035] R' is

[0036] The embodiment of the present application provides a preparation method of the above-mentioned waterborne epoxy curing agent, which includes the following steps:

[0037] Step 1: Prepare a phenolic epoxy resin modified amine solution.

[0038] As an implementation method, the phenolic epoxy resin modified amine solution is mainly obtained by mixing 30 parts of phenolic epoxy resin, 25 - 35 parts of organic fatty amine and 25 - 35 parts of solvent by mass. Among them, the organic fatty amine corresponds to the R group, and may include at least one of ethylenediamine, hexamethylenediamine, diethylenetriamine, tetraethylenepentamine and polyethylenepolyamine. The solvent is used to dissolve the organic fatty amine and phenolic epoxy resin, such as propylene glycol monomethyl ether and ethylene glycol monobutyl ether.

[0039] Specifically, the preparation method of the phenolic epoxy resin modified amine solution includes the following steps:

[0040] Mix the organic fatty amine and part of the solvent and stir evenly to obtain a dissolved solution, then add the solution prepared from the phenolic epoxy resin and the remaining solvent to the dissolved solution. When adding, control the temperature at 55 - 65°C. After adding, keep warm for 2 - 4 h and adjust the solid content to 50 - 80% to obtain the phenolic epoxy resin modified amine solution.

[0041] Step 2: Introduce a polyether segment and a bisphenol A segment into the phenolic epoxy resin modified amine. Usually, a phenolic epoxy resin modified amine solution with a solid content of 50 - 80% is subjected to a capping reaction with a waterborne epoxy resin having a polyether segment and an oil-based epoxy resin having a bisphenol A segment. Among them, the dosage ratio of the phenolic epoxy resin modified amine solution, the waterborne epoxy resin and the oil-based epoxy resin is 40 - 50:2 - 6:2 - 9; the waterborne epoxy resin includes at least one of polyethylene glycol diglycidyl ether, polypropylene glycol diglycidyl ether and polybutylene glycol diglycidyl ether; the oil-based epoxy resin is one of E-44 epoxy resin, E-20 epoxy resin and E-51 epoxy resin.

[0042] Specifically, the capping reaction is mainly to stir the waterborne epoxy resin and the oil-based epoxy resin evenly, and then add them to the phenolic epoxy resin modified amine solution. When adding, control the temperature at 55 - 65°C. After adding, keep warm for 2 - 3 h and adjust the solid content to 50 - 80% to obtain the waterborne epoxy curing agent.

[0043] The embodiments of the present application also provide an aqueous epoxy coating, which comprises an aqueous epoxy emulsion and the above-mentioned aqueous epoxy curing agent. The aqueous epoxy emulsion can be purchased or prepared by oneself, and its epoxy equivalent is 1066 g / mol. Usually, the mass of the aqueous epoxy curing agent is 1 / 10 of the mass of the aqueous epoxy emulsion. The epoxy resin curing agent in the coating reacts chemically with the epoxy resin in the aqueous epoxy emulsion to form a network three-dimensional polymer, which envelopes the composite material aggregate in the network, turns the linear resin into a tough solid, and forms a coating film.

[0044] The features and properties of the present application will be further described in detail with reference to the following embodiments.

[0045] Example 1

[0046] This example provides an aqueous epoxy curing agent, which is prepared according to the following steps:

[0047] Step 1: Prepare a phenolic epoxy resin modified amine solution:

[0048] By weight, pour 15 parts by weight of propylene glycol methyl ether into a three-necked flask, then add 30 parts by weight of diethylenetriamine, and stir to dissolve the diethylenetriamine in the propylene glycol methyl ether to obtain a dissolved solution; subsequently, slowly add 30 parts by weight of phenolic epoxy resin dissolved in 15 parts by weight of propylene glycol methyl ether dropwise to the three-necked flask. During the dropping process, control the temperature of the solution in the three-necked flask at 60 °C. After the dropping is completed, continue to keep the temperature for reaction for 3 h, and adjust the solid content to 50% by adding deionized water and stirring to obtain a phenolic epoxy resin modified amine solution.

[0049] The phenolic epoxy resin modified amine solution is a light yellow liquid, with a solid content of 50% and a viscosity of 2500 mPa·s, and can be stored for 6 months without stratification.

[0050] After testing, the structural formula of the phenolic epoxy resin modified amine in the phenolic epoxy resin modified amine solution is:

[0051] R is

[0052] Step 2: Introduce a polyether chain segment and a bisphenol A chain segment into the phenolic epoxy resin modified amine:

[0053] By weight, add 48 parts by weight of the phenolic epoxy resin modified amine solution to a three-necked flask. Additionally, weigh 4 parts by weight of polyethylene glycol diglycidyl ether and 3 parts by weight of E-44 epoxy resin, stir evenly, and slowly add them dropwise to the three-necked flask. During the dropping process, control the temperature of the solution in the three-necked flask at 60 °C. After the dropping is completed, continue to keep the temperature at 60 °C for reaction for 2 h, add deionized water, and stir at high speed for 30 minutes to adjust the solid content to 50% to obtain an aqueous epoxy curing agent.

[0054] The waterborne epoxy curing agent is a light yellow liquid with a solid content of 50% and a viscosity of 4860 mPa·s, and it can be stored for 6 months without stratification.

[0055] Example 2

[0056] This example provides a waterborne epoxy curing agent, which is prepared according to the following steps:

[0057] Step 1: Prepare a phenolic epoxy resin modified amine solution:

[0058] By weight, pour 15 parts by weight of propylene glycol methyl ether into a three-necked flask, then add 30 parts by weight of ethylenediamine, and stir to dissolve the ethylenediamine in the propylene glycol methyl ether to obtain a dissolved solution; subsequently, slowly add dropwise 30 parts by weight of phenolic epoxy resin dissolved in 15 parts by weight of propylene glycol methyl ether to the three-necked flask. During the dropping process, control the temperature of the solution in the three-necked flask at 60°C. After the dropping is completed, continue to keep the temperature for reaction for 2 h, and adjust the solid content to 50% to obtain the phenolic epoxy resin modified amine solution.

[0059] The phenolic epoxy resin modified amine solution is a light yellow liquid with a solid content of 50% and a viscosity of 3500 mPa·s, and it can be stored for 6 months without stratification.

[0060] After testing, the structural formula of the phenolic epoxy resin modified amine in the phenolic epoxy resin modified amine solution is: R is

[0061] Step 2: Introduce a polyether segment and a bisphenol A segment into the phenolic epoxy resin modified amine:

[0062] By weight, add 48 parts by weight of the phenolic epoxy resin modified amine solution to a three-necked flask. Additionally, weigh 4 parts by weight of polyethylene glycol diglycidyl ether and 3 parts by weight of E-44 epoxy resin, stir evenly, and slowly add dropwise to the three-necked flask. During the dropping process, control the temperature of the solution in the three-necked flask at 60°C. After the dropping is completed, continue to keep the temperature at 60°C for reaction for 2 h, add deionized water, stir at high speed for 30 minutes, and adjust the solid content to 50% to obtain the waterborne epoxy curing agent.

[0063] The waterborne epoxy curing agent is a light yellow liquid with a solid content of 50% and a viscosity of 12000 mPa·s, and it can be stored for 6 months without stratification.

[0064] Example 3

[0065] This example provides a waterborne epoxy curing agent, which is prepared according to the following steps:

[0066] Step 1: Prepare a phenolic epoxy resin modified amine solution:

[0067] By weight parts, 15 parts by weight of propylene glycol methyl ether were poured into a three-necked flask, and then 35 parts by weight of hexamethylenediamine were added. After stirring to dissolve hexamethylenediamine in propylene glycol methyl ether, a dissolved solution was obtained. Subsequently, 30 parts by weight of phenolic epoxy resin dissolved in 15 parts by weight of propylene glycol methyl ether were slowly added dropwise to the three-necked flask. During the dropping process, the temperature of the solution in the three-necked flask was controlled at 60 °C. After the dropping was completed, the reaction was continued under insulation for 4 h. The solid content was adjusted to 50% by adding deionized water and stirring to obtain a phenolic epoxy resin modified amine solution.

[0068] The phenolic epoxy resin modified amine solution is a light yellow liquid, with a solid content of 50% and a viscosity of 4000 mPa·s, and can be stored for 6 months without stratification.

[0069] After testing, the structural formula of the phenolic epoxy resin modified amine in the phenolic epoxy resin modified amine solution is: R is

[0070] Step two: Introduce a polyether segment and a bisphenol A segment into the phenolic epoxy resin modified amine:

[0071] By weight parts, 48 parts by weight of the phenolic epoxy resin modified amine solution were added to a three-necked flask. Additionally, 4 parts by weight of polyethylene glycol diglycidyl ether and 3 parts by weight of E-44 epoxy resin were weighed and stirred evenly, and then slowly added dropwise to the three-necked flask. During the dropping process, the temperature of the solution in the three-necked flask was controlled at 60 °C. After the dropping was completed, the reaction was continued under insulation at 60 °C for 3 h. Deionized water was added and stirred at high speed for 30 minutes to adjust the solid content to 50% to obtain an aqueous epoxy curing agent.

[0072] The aqueous epoxy curing agent is a light yellow liquid, with a solid content of 50% and a viscosity of 18000 mPa·s, and can be stored for 6 months without stratification.

[0073] Example 4

[0074] This example provides an aqueous epoxy curing agent, which is prepared according to the following steps:

[0075] By weight parts, 48 parts by weight of the phenolic epoxy resin modified amine solution in Example 1 were added to a three-necked flask. Additionally, 4 parts by weight of polypropylene glycol diglycidyl ether and 2 parts by weight of E-51 epoxy resin were weighed and stirred evenly, and then slowly added dropwise to the three-necked flask. During the dropping process, the temperature of the solution in the three-necked flask was controlled at 60 °C. After the dropping was completed, the reaction was continued under insulation at 60 °C for 2 h. Deionized water was added and stirred at high speed for 30 minutes to prepare an aqueous epoxy curing agent with a solid content of 50%.

[0076] The waterborne epoxy curing agent is a light yellow liquid, with a solid content of 50% and a viscosity of 3500 mPa·s. It can be stored for 6 months without stratification.

[0077] Example 5

[0078] This example provides a waterborne epoxy curing agent, which is prepared according to the following steps:

[0079] By weight, 48 parts by weight of the phenolic epoxy resin modified amine solution in Example 1 was added to a three-necked flask. Additionally, 4 parts by weight of polybutylene glycol diglycidyl ether and 7 parts by weight of E-20 epoxy resin were weighed and stirred evenly, and then slowly added dropwise to the three-necked flask. During the dropping process, the temperature of the solution in the three-necked flask was controlled at 60 °C. After the dropping was completed, the reaction was continued at 60 °C for 2 h, and then deionized water was added and stirred at high speed for 30 minutes to prepare a waterborne epoxy curing agent with a solid content of 50%.

[0080] The waterborne epoxy curing agent is a light yellow liquid, with a solid content of 50% and a viscosity of 3000 mPa·s. It can be stored for 6 months without stratification.

[0081] Experimental method:

[0082] Since epoxy resins using amines as curing agents are usually two-component epoxy resins cured at room temperature, different component A was used as the waterborne epoxy curing agent and the same component B waterborne epoxy emulsion was used as the waterborne epoxy resin. A two-component waterborne epoxy varnish (waterborne epoxy coating) was obtained by mixing them at a molar ratio of active hydrogen to epoxy group of 1:1.25. Then, the two-component waterborne epoxy varnish was formed into a film and its properties were tested.

[0083] The tests were carried out according to the following standard methods:

[0084] Surface drying time: According to the requirements of the national standard GB / T1728-1979, the surface drying time of various paint films was tested by the finger-touch method;

[0085] Hardness: Tested according to the national standard GB / T6739-2006 "Determination of film hardness by pencil method for paints and varnishes";

[0086] Adhesion: According to the requirements of the national standard GB / T9286-1998, the adhesion of different paint films was rated by the method of manually scribing grids;

[0087] Water resistance: Tested according to the requirements of the national standard GB / T1733-99;

[0088] Acid resistance: Tested according to the requirements of the national standard GB1763-79.

[0089] Detection environmental conditions: Temperature 25 °C ± 2 °C; Humidity (50 ± 5%)RH.

[0090] The compositions of different two-component waterborne epoxy varnishes and the test results of the corresponding paint films are shown in Table 1.

[0091] Table 1 Compositions of two-component waterborne epoxy varnishes and test results of paint film properties

[0092]

[0093]

[0094] It can be seen from the test results in Table 1 that after the phenolic epoxy resin modified amine solution is modified by waterborne epoxy resin and oil-based epoxy resin, the curing rate of the formed waterborne epoxy coating can be significantly improved, and the mechanical properties and water resistance of the corresponding paint film.

[0095] In summary, the waterborne epoxy coating formed by the waterborne epoxy curing agent in the embodiments of the present application has good water dilutability, and the obtained coating film has excellent mechanical properties, water resistance and corrosion resistance.

[0096] The above are only the embodiments of the present application and are not used to limit the protection scope of the present application. For those skilled in the art, various changes and modifications can be made to the present application. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. An aqueous epoxy curing agent, characterized in that, it contains a compound, and the compound is obtained by introducing a polyether segment and a bisphenol A segment at the primary amine position of the R group in a phenolic epoxy resin modified amine. The structural formula of the phenolic epoxy resin modified amine is: R is: The aqueous epoxy curing agent mainly carries out a capping reaction on the phenolic epoxy resin modified amine solution with an aqueous epoxy resin and an oil-based epoxy resin; wherein, the phenolic epoxy resin modified amine solution contains the phenolic epoxy resin modified amine; the aqueous epoxy resin has the polyether segment, and the aqueous epoxy resin includes at least one of polyethylene glycol diglycidyl ether, polypropylene glycol diglycidyl ether, and polybutylene glycol diglycidyl ether; the oil-based epoxy resin has the bisphenol A segment, and the oil-based epoxy resin is one of E-44 epoxy resin, E-20 epoxy resin, and E-51 epoxy resin.

2. A preparation method of the aqueous epoxy curing agent according to claim 1, characterized in that, it mainly carries out a capping reaction on the phenolic epoxy resin modified amine solution with an aqueous epoxy resin and an oil-based epoxy resin; wherein, the phenolic epoxy resin modified amine solution contains the phenolic epoxy resin modified amine; the aqueous epoxy resin has the polyether segment; the oil-based epoxy resin has the bisphenol A segment.

3. According to the preparation method of the aqueous epoxy curing agent described in claim 2, characterized in that, the solid content of the phenolic epoxy resin modified amine solution is 50 - 80%, and the dosage ratio of the phenolic epoxy resin modified amine solution, the aqueous epoxy resin, and the oil-based epoxy resin is 40:2 - 6:2 - 9.

4. According to the preparation method of the aqueous epoxy curing agent described in claim 2 or 3, characterized in that, the capping reaction mainly stirs the aqueous epoxy resin and the oil-based epoxy resin evenly, then adds them to the phenolic epoxy resin modified amine solution, controls the temperature at 55 - 65 °C during the addition, and keeps warm for 2 - 4 h after the addition to obtain the aqueous epoxy curing agent.

5. According to the preparation method of the aqueous epoxy curing agent described in claim 2, characterized in that, the phenolic epoxy resin modified amine solution is mainly obtained by mixing 30 parts of phenolic epoxy resin, 25 - 35 parts of organic fatty amine, and 25 - 35 parts of solvent by mass and reacting them together. The organic fatty amine includes at least one of ethylenediamine, hexamethylenediamine, and diethylenetriamine.

6. According to the preparation method of the aqueous epoxy curing agent described in claim 5, characterized in that, the preparation method of the phenolic epoxy resin modified amine solution includes the following steps: Mix the organic fatty amine and part of the solvent evenly by stirring to obtain a dissolution solution, then add the solution prepared from the phenolic epoxy resin and the remaining solvent to the dissolution solution, control the temperature at 55 - 65 °C during the addition, keep warm for 3 - 4 h after the addition, and adjust the solid content to 50 - 80% to obtain the phenolic epoxy resin modified amine solution.

7. An aqueous epoxy coating, characterized in that, it includes an aqueous epoxy emulsion and the aqueous epoxy curing agent according to claim 1.

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