PREPARATION METHOD FOR EMULSIFIER, EMULSIFIER, AQUEOUS EPOXY RESIN DISPERSION AND FORMULATION METHOD

Abstract

A preparation method for an emulsifier, an emulsifier, an aqueous epoxy resin dispersion, and a formulation method. The preparation method for an emulsifier comprises reacting aminosulfonic acid and/or a sulfamate as a first reaction raw material with an epoxy resin in the presence of water, so as to obtain an ionic active emulsifier. The ionic active emulsifier molecule comprises at least one epoxy group from an epoxy resin and at least one sulfonic acid or sulfonate group from the first reaction raw material. The aqueous epoxy resin dispersion prepared by using the emulsifier has the characteristics of good stability and good corrosion resistance after curing, and can be used in the fields of coatings, adhesives, etc.

Claims

1. A preparation method for an ionic active emulsifier, comprising: reacting sulfamic acid and/or sulfamate as a first reaction raw material with an epoxy resin to obtain the ionic active emulsifier, wherein the molecule of the ionic active emulsifier comprises at least one epoxy group from the epoxy resin and at least one sulfonic acid or sulfonate group from the first reaction raw material.

2. The preparation method according to claim 1, wherein in the reaction system for preparing the ionic active emulsifier, the molar ratio of the total amount of epoxy groups provided by the epoxy resin to the total amount of active hydrogens comprised in the amino (amine) groups in the first reaction raw material is at least 2:1.

3-13. (canceled)

14. The preparation method according to claim 1, wherein in the reaction system for preparing the ionic active emulsifier, the mass ratio of water to the first reaction raw material is not less than 1:20.

15. The preparation method according to claim 1, wherein in the process of preparing the ionic active emulsifier, after the first reaction raw material is mixed with water, the mixture is reacted with the epoxy resin optionally in the presence of a solvent used for reducing the viscosity of the reaction system at a temperature of 50° C. to 150° C. to carry out a ring-opening reaction of epoxy groups by amino groups to obtain the ionic active emulsifier.

16. The preparation method according to claim 15, wherein the reaction temperature is 60° C. to 100° C.

17. The preparation method according to claim 1, wherein the molecule of the epoxy resin comprises at least two epoxy groups.

18. The preparation method according to claim 1, wherein the epoxy value of the epoxy resin is not greater than 0.6.

19. The preparation method according to claim 1, wherein the sulfamate is prepared from sulfamic acid by an alkali neutralization process.

20. The preparation method according to claim 19, wherein the alkali neutralization process has a degree of neutralization of 90% to 98%.

21. The preparation method according to claim 1, wherein the sulfonate group in the molecule of the ionic active emulsifier is a metal sulfonate group.

22. The preparation method according to claim 21, wherein the metal sulfonate group is a sodium sulfonate group or a potassium sulfonate group.

23. An ionic active emulsifier prepared by the preparation method according to claim 1.

24. An aqueous epoxy resin dispersion, comprising an ionic active emulsifier prepared by the preparation method according to claim 1.

25. The aqueous epoxy resin dispersion according to claim 24, wherein the total content of sulfonic acid groups and sulfonate groups of the ionic active emulsifier is 0.01 wt % to 50 wt % of the total solid mass in the aqueous epoxy resin dispersion.

26. The aqueous epoxy resin dispersion according to claim 24, further comprising at least one non-ionic active emulsifier.

27. The aqueous epoxy resin dispersion according to claim 26, wherein the content of the non-ionic active emulsifier is 0.1 wt % to 90 wt % of the total solid mass in the aqueous epoxy resin dispersion.

28. The aqueous epoxy resin dispersion according to claim 26, wherein the non-ionic active emulsifier is prepared by: mixing polyetheramine with an epoxy resin, and carrying out a ring-opening reaction using amino groups of the polyetheramine and epoxy groups of the epoxy resin to obtain the non-ionic active emulsifier, wherein the molecule of the non-ionic active emulsifier comprises at least one epoxy group from the epoxy resin.

29. The aqueous epoxy resin dispersion according to claim 28, wherein during preparation, the molar ratio of the total amount of epoxy groups of the epoxy resin to the total amount of active hydrogens comprised in the amino groups of the polyetheramine is at least 2:1.

30. The aqueous epoxy resin dispersion according to claim 28, wherein the reaction condition of the ring-opening reaction is that the reaction is carried out for 1 hour to 5 hours at 40° C. to 140° C.

31. The aqueous epoxy resin dispersion according to claim 26, wherein the non-ionic active emulsifier is prepared by: mixing a polyether-anhydride reactant whose molecule comprises at least one carboxyl group with an epoxy resin whose molecule comprises at least two epoxy groups, and carrying out a ring-opening reaction using the carboxyl group(s) of the polyether-anhydride reactant and the epoxy groups of the epoxy resin to obtain the non-ionic active emulsifier, wherein the molar ratio of the total amount of epoxy groups of the epoxy resin to the total amount of carboxyl group(s) of the polyether-anhydride reactant is at least 1:1.

32. The aqueous epoxy resin dispersion according to claim 31, wherein the reaction condition of the ring-opening reaction is that the reaction is carried out for 1 hour to 5 hours under the action of a catalyst at 40° C. to 140° C.; the catalyst is triphenylphosphine or boron trifluoride diethyl ether.

33. The aqueous epoxy resin dispersion according to claim 31, wherein the polyether-anhydride reactant is obtained by subjecting a polyether polyol and an anhydride from a polycarboxylic acid whose molecule comprises 2 to 4 carboxyl groups to an esterification reaction, wherein the molar ratio of the total amount of anhydride groups of the anhydride to the total amount of hydroxyl groups of the polyether polyol is 1 to 1.2.

34. The aqueous epoxy resin dispersion according to claim 33, wherein the reaction temperature of the esterification reaction is 40° C. to 150° C.

35. The aqueous epoxy resin dispersion according to claim 32, wherein the amount of the catalyst is 0.05 wt % to 2 wt % of the total solid mass in the reaction system.

36. The aqueous epoxy resin dispersion according to claim 26, wherein the molecule of the non-ionic active emulsifier comprises at least 10 ethoxy segments and at least one epoxy group.

37. The aqueous epoxy resin dispersion according to claim 26, wherein in the molecule of the non-ionic active emulsifier, the content of ethoxy units bonded to polyether chains is 40 wt % to 95 wt %.

38. A formulation method of the aqueous epoxy resin dispersion according to claim 24, comprising: adding a material comprising the ionic active emulsifier and the optional non-ionic active emulsifier in proportion required for formulating the aqueous epoxy resin dispersion to an epoxy resin, and adding water to disperse the material to form an epoxy resin aqueous dispersion; or adding remaining materials in proportion required for formulating the aqueous epoxy resin dispersion to a system comprising the ionic active emulsifier and the optional non-ionic active emulsifier, and dispersing the remaining materials and the system to form an aqueous epoxy resin dispersion; wherein at least one of the ionic active emulsifier and the optional non-ionic active emulsifier is prepared in the system.

Description

DETAILED DESCRIPTION

[0048] The present disclosure will be further described in detail through the following examples, but the following examples shall not be construed as limitations to the scope of the present disclosure. Without departing from the above method ideas of the present disclosure, various substitutions or changes made in accordance with the general technical knowledge and conventional means of the art shall be included within the scope of the present disclosure.

[0049] Materials used in Examples and Comparative Examples are shown in the following table.

TABLE-US-00001 TABLE 1 Material Form Supplier CAS No. Aminoethanesulfonic acid Solid Wanhua Chemical  107-35-7 N-aminoethylethanesulfonic acid Solid alading 34730-59-1 3-(cyclohexamino)-propanesulfonic acid Solid alading  1135-40-6 Polyethylene glycol Solid Wanhua Chemical 25322-68-3 Polyethylene glycol methyl ether Solid Wanhua Chemical  9004-74-4 Polyetheramine Liquid Taiga Additive  9046-10-0 Epoxy resin (E12/E20/E44/E51) Solid/liquid Baling Sinopec 25068-38-6 Trimellitic anhydride Solid TCI  522-30-7 Pyromellitic anhydride Solid TCI   89-32-7 Hexahydrophthalic anhydride Solid TCI   85-42-7

[0050] In the following Examples and Comparative Examples, the reagents used are analytical pure, unless otherwise specified; the sulfamate used is obtained by neutralizing the corresponding sulfamic acid with sodium hydroxide or potassium hydroxide; and the content is mass content, unless otherwise specified.

[0051] Preparation of an Ionic Active Emulsifier A

[0052] Example 1a: 800 g of epoxy resin E12 (that is, the epoxy value was 0.12) and 200 g of PMOP were added to 70 g of aminoethanesulfonic acid (where the solid content was 20% and the rest was water), the temperature was slowly raised to 80° C., the mixture was stirred for reaction under reflux at constant temperature for about 1 hour, and after the epoxy value was measured to be 0.035 mol/100 g (by the hydrochloric acid-acetone method, which was used in the following Examples and Comparative Examples), which basically reached the theoretical epoxy value, an ionic active emulsifier was obtained.

[0053] Example 1b: 100 g of epoxy resin E44 and 30 g of PMOP were added to 70 g of 3-(cyclohexamino)-propanesulfonic salt (neutralized with potassium hydroxide with a neutralization degree of 95%, where the solid content was 50% and the rest was water), the temperature was slowly raised to 80° C., the mixture was stirred for reaction under reflux at constant temperature for about 1 hour, and after the epoxy value was measured to be 0.24 mol/100 g, which basically reached the theoretical epoxy value, an ionic active emulsifier was obtained.

[0054] Example 1c: 230 g of epoxy resin E51 and 50 g of PMOP were added to 70 g of N-aminoethylethanesulfonic salt (neutralized with sodium hydroxide with a neutralization degree of 98%, where the solid content was 30% and the rest was water), the temperature was slowly raised to 80° C., the mixture was stirred for reaction under reflux at constant temperature for about 1 hour, and after the epoxy value was measured to be 0.28 mol/100 g, which basically reached the theoretical epoxy value, an ionic active emulsifier was obtained.

[0055] Comparative Example 1a: 800 g of epoxy resin E12 and 200 g of PMOP were added to 14 g of aminoethanesulfonic acid (solid, with a melting point of >300° C.), the temperature was slowly raised to 80° C., and the mixture was stirred for reaction at constant temperature for about 5 hours. There was still a large amount of white solid in the system, and after a detection, the white solid was found to be aminoethanesulfonic acid and/or aminoethanesulfonic salt, indicating that aminoethanesulfonic acid and/or aminoethanesulfonic salt failed to be reacted with the epoxy resin to prepare an emulsifier under the above conditions.

[0056] Comparative Example 1b: 180 g of epoxy resin E44 and 90 g of PMOP were added to 35 g of 3-(cyclohexamino)-propanesulfonic potassium (solid, with a melting point of >300° C.), the temperature was slowly raised to 80° C., and the mixture was stirred for reaction at constant temperature for about 5 hours. There was still a large amount of white solid in the system, and after a detection, the white solid was found to be cyclohexaminopropanesulfonic acid and/or cyclohexaminopropanesulfonic salt, indicating that cyclohexaminopropanesulfonic acid and/or cyclohexaminopropanesulfonic salt failed to be reacted with the epoxy resin E20 to prepare an emulsifier under the above conditions.

[0057] Comparative Example 1c: 90 g of epoxy resin E51 and 50 g of PMOP were added to 21 g of N-aminoethylethanesulfonic sodium (solid, with a melting point of >300° C.), the temperature was slowly raised to 80° C., and the mixture was stirred for reaction at constant temperature for about 5 hours. There was still a large amount of white solid in the system, and after a detection, the white solid was found to be N-aminoethylethanesulfonic acid and/or N-aminoethylethanesulfonic salt, indicating that N-aminoethylethanesulfonic acid and/or N-aminoethylethanesulfonic salt failed to be reacted with the epoxy resin to prepare an emulsifier under the above conditions.

[0058] According to the above Examples and Comparative Examples, it was surprisingly found that it was difficult for solid sulfamic acid and/or sulfamate to react with the epoxy resin, but when they were mixed with water, the reaction could proceed smoothly under relatively mild conditions. The synthesis method of Examples 1a to 1c was experimentally verified to be also suitable for the reaction of other derivatives of sulfamic acid and/or sulfamate having similar structures with the epoxy resin.

[0059] Preparation of a Non-Ionic Active Emulsifier B

[0060] Example 2a: Synthesis route of a non-ionic active emulsifier B: 1000 g of molten and dehydrated polyethylene glycol (with a molecular weight of 6000 and an EO content of not less than 80 wt %) was injected into a reaction kettle, the kettle temperature was maintained at 80° C., then 53 g of hexahydrophthalic anhydride was added into the reaction kettle, the temperature was raised to 100° C., and the reaction was carried out for about 3 hours; after the acid value of the sample was tested to reach the theoretical value of 10 mgKOH/g, 210 g of liquid epoxy resin E20 was injected, after stirring evenly, 3.5 g of a triphenylphosphine (TPP) catalyst was added, the reaction was carried out at a constant temperature of 130° C. for 3 hours, and after the acid value was tested to be −0.25 mgKOH/g, the material was discharged.

[0061] Example 2b: Synthesis route of a non-ionic active emulsifier B: 1000 g of molten and dehydrated polyetheramine (with a molecular weight of 3000, Taiga Additive M-2070) was injected into a reaction kettle, the kettle temperature was maintained at 100° C., then 350 g of liquid epoxy resin E44 was injected, after stirring evenly, the reaction was carried out at a constant temperature of 130° C. for 3 hours, and after the epoxy value was tested to be 0.075 mol/100 g, the material was discharged.

[0062] Example 2c: Synthesis route of a non-ionic active emulsifier B: 2000 g of molten and dehydrated polyethylene glycol monomethyl ether (with a molecular weight of 8000 and an EO content of not less than 80 wt %) was injected into a reaction kettle, the kettle temperature was maintained at 100° C., then 53 g of trimellitic anhydride was added into the reaction kettle, the temperature was raised to 130° C., and the reaction was carried out for about 3 hours; after the acid value of the sample was tested to reach the theoretical value of 7 mgKOH/g, 170 g of liquid epoxy resin E51 was injected, after stirring evenly, 6 g of a triphenylphosphine (TPP) catalyst was added, the reaction was carried out at a constant temperature of 130° C. for 3 hours, and after the acid value was tested to be −0.4 mgKOH/g, the material was discharged.

[0063] Preparation of an Aqueous Epoxy Resin Dispersion

[0064] Example 3a: 400 g of molten epoxy resin E20 was injected into a dispersion kettle, the temperature in the kettle was maintained at 100° C., then an active emulsifier A (80 g, obtained in Example 1a) and a solvent of propylene glycol monomethyl ether (PMOP) (70 g) were injected, and the above materials were stirred and mixed at 800 r/min for 20 minutes; after that, the temperature was lowered to 75° C., the rotational speed was raised to 1200 r/min, and 350 g of deionized water was dripped within 2 hours (the first ½ amount of water was slowly dripped); after the completion of dripping, the system was cooled to 50° C. for discharging. The test results of the dispersion are as follows.

[0065] The particle size of the dispersion was about 510 nm (test instrument: Zetasizer Nano ZS, test method: dispersing the dispersion in deionized water, which were also used in the following Examples and Comparative Examples).

[0066] The total content of sulfonic acid and sulfonate groups was 0.73 wt % (the test criterion or method of determination was: the total amount of added sulfonic acid and sulfonate groups divided by the total mass of the emulsion, which was also used in following Examples and Comparative Examples).

[0067] The viscosity was 1500 cp (test instrument: Brookfield viscometer DV1, test method: direct test at 25° C., which were also used in following Examples and Comparative Examples).

[0068] The solid content was 53%.

[0069] Example 3b: 400 g of molten epoxy resin E20 was injected into a dispersion kettle, the temperature in the kettle was maintained at 100° C., then an active emulsifier A (80 g, obtained in Example 1b) and a solvent of propylene glycol monomethyl ether (PMOP) (76 g) were injected, and the above materials were stirred and mixed at 800 r/min for 20 minutes; after that, the temperature was lowered to 75° C., the rotational speed was raised to 1200 r/min, and 380 g of deionized water was dripped within 2 hours (the first ½ amount of water was slowly dripped); after the completion of dripping, the system was cooled to 50° C. for discharging. The test results of the dispersion are as follows.

[0070] The particle size of the dispersion was about 420 nm.

[0071] The total content of sulfonic acid and sulfonate groups was 1.46 wt %.

[0072] The viscosity was 950 cp.

[0073] The solid content was 51%.

[0074] Example 3c: 400 g of molten epoxy resin E20 was injected into a dispersion kettle, the temperature in the kettle was maintained at 100° C., then an active emulsifier A (95 g, obtained in Example 1c) and a solvent of propylene glycol monomethyl ether (PMOP) (95 g) were injected, and the above materials were stirred and mixed at 800 r/min for 20 minutes; after that, the temperature was lowered to 75° C., the rotational speed was raised to 1200 r/min, and 400 g of deionized water was dripped within 2 hours (the first ½ amount of water was slowly dripped); after the completion of dripping, the system was cooled to 50° C. for discharging. The test results of the dispersion are as follows.

[0075] The particle size of the dispersion was about 380 nm.

[0076] The total content of sulfonic acid and sulfonate groups was 1.63 wt %.

[0077] The viscosity was 730 cp.

[0078] The solid content was 50%.

[0079] Example 3d-1: 400 g of molten epoxy resin E20 was injected into a dispersion kettle, the temperature in the kettle was maintained at 100° C., then an active emulsifier A (40 g, obtained in Example 1a), a non-ionic active emulsifier B (70 g, obtained in Example 2a), and a solvent of propylene glycol monomethyl ether (PMOP) (80 g) were injected, and the above materials were stirred and mixed at 800 r/min for 20 minutes; after that, the temperature was lowered to 75° C., the rotational speed was raised to 1200 r/min, and 400 g of deionized water was dripped within 2 hours (the first ½ amount of water was slowly dripped); after the completion of dripping, the system was cooled to 50° C. for discharging. The test results of the dispersion are as follows.

[0080] The particle size of the dispersion was about 530 nm.

[0081] The total content of sulfonic acid and sulfonate groups was 0.34 wt %.

[0082] The viscosity was 1200 cp.

[0083] The solid content was 52%.

[0084] Example 3d-2: 400 g of molten epoxy resin E20 was injected into a dispersion kettle, the temperature in the kettle was maintained at 100° C., then an active emulsifier A (40 g, obtained in Example 1b), a non-ionic active emulsifier B (70 g, obtained in Example 2b), and a solvent of propylene glycol monomethyl ether (PMOP) (80 g) were injected, and the above materials were stirred and mixed at 800 r/min for 20 minutes; after that, the temperature was lowered to 75° C., the rotational speed was raised to 1200 r/min, and 400 g of deionized water was dripped within 2 hours (the first ½ amount of water was slowly dripped); after the completion of dripping, the system was cooled to 50° C. for discharging. The test results of the dispersion are as follows.

[0085] The particle size of the dispersion was about 570 nm.

[0086] The total content of sulfonic acid and sulfonate groups was 0.32 wt %.

[0087] The viscosity was 1050 cp.

[0088] The solid content was 51%.

Example 3D-3

[0089] Preparation of a dispersion by a one-step method: 56 g of polyetheramine (with a molecular weight of 2000), 3.5 g of aminoethanesulfonic acid, 450 g of epoxy resin E20, and 80 g of a solvent of propylene glycol methyl ether were added into a dispersion kettle at the same time, the temperature was raised to 100° C., the reaction was carried out for 2.5 h, and after the reaction was completed, the materials in the kettle were stirred and mixed at 800 r/min for 20 minutes; after that, the temperature was lowered to 75° C., the rotational speed was raised to 1200 r/min, and 400 g of deionized water was dripped within 2 hours (the first ½ amount of water was slowly dripped); after the completion of dripping, the system was cooled to 50° C. for discharging. The test results of the dispersion are as follows.

[0090] The particle size of the dispersion was about 502 nm.

[0091] The total content of sulfonic acid and sulfonate groups was 0.68 wt %.

[0092] The viscosity was 930 cp.

[0093] The solid content was 51%.

[0094] Example 3e: 400 g of molten epoxy resin E20 was injected into a dispersion kettle, the temperature in the kettle was maintained at 100° C., then a non-ionic active emulsifier B (110 g, obtained in Example 2a) and a solvent of propylene glycol monomethyl ether (PMOP) (70 g) were injected, and the above materials were stirred and mixed at 800 r/min for 20 minutes; after that, the temperature was lowered to 75° C., the rotational speed was raised to 1200 r/min, and 400 g of deionized water was dripped within 2 hours (the first ½ amount of water was slowly dripped); after the completion of dripping, the system was cooled to 50° C. for discharging. The test results of the dispersion are as follows.

[0095] The particle size of the dispersion was about 1100 nm.

[0096] The total content of sulfonic acid and sulfonate groups was 0 wt %.

[0097] The viscosity was 5800 cp.

[0098] The solid content was 52%.

[0099] Example 3f: 400 g of molten epoxy resin E20 was injected into a dispersion kettle, the temperature in the kettle was maintained at 100° C., then a non-ionic active emulsifier B (110 g, obtained in Example 2b) and a solvent of propylene glycol monomethyl ether (PMOP) (80 g) were injected, and the above materials were stirred and mixed at 800 r/min for 20 minutes; after that, the temperature was lowered to 75° C., the rotational speed was raised to 1200 r/min, and 400 g of deionized water was dripped within 2 hours (the first ½ amount of water was slowly dripped); after the completion of dripping, the system was cooled to 50° C. for discharging. The test results of the dispersion are as follows.

[0100] The particle size of the dispersion was about 980 nm.

[0101] The total content of sulfonic acid and sulfonate groups was 0 wt %.

[0102] The viscosity was 4300 cp.

[0103] The solid content was 51%.

[0104] Example 3g: 400 g of molten epoxy resin E20 was injected into a dispersion kettle, the temperature in the kettle was maintained at 100° C., then a non-ionic active emulsifier B (110 g, obtained in Example 2c) and a solvent of propylene glycol monomethyl ether (PMOP) (80 g) were injected, and the above materials were stirred and mixed at 800 r/min for 20 minutes; after that, the temperature was lowered to 75° C., the rotational speed was raised to 1200 r/min, and 400 g of deionized water was dripped within 2 hours (the first ½ amount of water was slowly dripped); after the completion of dripping, the system was cooled to 50° C. for discharging. The test results of the dispersion are as follows.

[0105] The particle size of the dispersion was about 920 nm.

[0106] The total content of sulfonic acid and sulfonate groups was 0 wt %.

[0107] The viscosity was 5200 cp.

[0108] The solid content was 51%.

[0109] Performance test of the aqueous epoxy resin dispersion:

TABLE-US-00002 TABLE 2 Component I Mass ratio Composition Supplier wt % H.sub.2O  10.0 Dispersant BYK190 BYK  2.0 pH regulator AMP-95 Angus  0.2 Antifoaming agent BYK024 BYK  0.3 Titanium white R902 DuPont  6.0 Barium sulfate Jiande Chemistry  10.0 Zinc phosphate Sanjing  8.0 Wollastonite Jiangxi Aote  14.0 Carbon black FW200 Evonik  0.5 Aqueous epoxy resin Form Examples/Comparative  48.0 dispersion Examples 3a to 3g Wetting agent BYK346 BYK  0.3 Flash-rust inhibitor FA179 Elementis  0.2 Thickening agent U905 Wanhua Chemical  0.5 Total 100.0

TABLE-US-00003 TABLE 3 Component II Mass ratio Composition Supplier wt % Epoxy curing agent Hexion  40 EPIKURE8530 Chemistry Film-forming auxiliary Dow Chemical  20 DpnB H.sub.2O  40 Total 100

[0110] The water-based epoxy antirust paint Component I prepared according to Table 2 and Component II prepared according to Table 3 were mixed in a ratio of 8.5:1 and then cured for half an hour. The two-component epoxy paint was coated on the surface-polished carbon steel sheet with a dry film thickness of 70 um to 80 um, leveled at room temperature for 10 minutes to 15 minutes, baked at 80° C. for 30 minutes, and cured at 25° C. for 7 days to obtain a two-component epoxy cured film. Determination of resistance to neutral salt spray was carried out according to GB/T 1771. Within the specified test time (500 hours), when the blank part of the sheet surface is free of rust and foaming and the rust and foaming diffusion width at the notch part of the sheet surface is less than 2 mm, the resistance to neutral salt spray is scored 5; when the blank part of the sheet surface is free of rust and has a small amount of foaming and the rust and foaming diffusion width at the notch part of the sheet surface is less than 2 mm, the resistance to neutral salt spray is scored 4; when the blank part of the sheet surface shows rust and foaming and the rust and foaming diffusion width at the notch part of the sheet surface is less than 2 mm, the resistance to neutral salt spray is scored 3. The test results are shown in Table 4.

TABLE-US-00004 TABLE 4 Dispersion Examples/ Comparative Examples 3a 3b 3c 3d-1 3d-2 3d-3 3e 3f 3g Content of 0.73 1.46 1.63 0.34 0.32 0.35 0 0 0 sulfonic acid and/or sulfonate (wt %) Dispersion 510 420 380 530 570 502 1100 980 920 particle size (nm) Dispersion 23 19 28 35 29 30 3 10 9 storage duration at 50° C. (day) Epoxy paint 5 5 5 5 5 5 3 4 4 salt spray resistance (500 h) Dispersion <15 <12 <15 <20 <15 <15 >3 >6 >6 shelf life (month)

[0111] From the comparison of the above properties, it can be seen that the addition of a small amount of the active emulsifier A including sulfonic acid and/or sulfonate can effectively reduce the particle size of the dispersion, improve the stability of the dispersion, and improve the salt spray resistance of the product.