Composite emulsifier, preparation method thereof, and water-based epoxy resin emulsion and coating containing composite emulsifier
阅读说明：本技术 一种复合乳化剂及其制备方法和包含复合乳化剂的水性环氧树脂乳液和涂料 (Composite emulsifier, preparation method thereof, and water-based epoxy resin emulsion and coating containing composite emulsifier ) 是由 李效玉 陈立生 袁培臣 于 2021-09-09 设计创作，主要内容包括：本发明属于乳化剂技术领域,本发明提供了一种复合乳化剂及其制备方法。本发明的复合乳化剂包含非离子乳化剂和阴离子乳化剂；阴离子乳化剂和非离子乳化剂的质量比为1～5:5～15。本发明还提供了一种包含复合乳化剂的水性环氧树脂乳液和涂料。本发明的复合乳化剂制备的水性环氧树脂乳液具有乳化剂用量小,乳液粒径小,储存稳定性好等优异性能；本发明的涂料具有优异的耐H-(2)SO-(4)腐蚀性能和耐中性盐雾性能。(The invention belongs to the technical field of emulsifiers, and provides a composite emulsifier and a preparation method thereofA preparation method. The composite emulsifier comprises a nonionic emulsifier and an anionic emulsifier; the mass ratio of the anionic emulsifier to the nonionic emulsifier is 1-5: 5-15. The invention also provides a water-based epoxy resin emulsion containing the composite emulsifier and a coating. The water-based epoxy resin emulsion prepared by the composite emulsifier has the excellent performances of small emulsifier dosage, small emulsion particle size, good storage stability and the like; the coating of the invention has excellent H resistance 2 SO 4 Corrosion performance and neutral salt spray resistance.)
1. A composite emulsifier, which is characterized by comprising a nonionic emulsifier and an anionic emulsifier;
the structural formula of the nonionic emulsifier is as follows:
n＝40～83；
the structural formula of the anionic emulsifier is as follows:
structural formula of the nonionic emulsifier and structural formula of the anionic emulsifierIndependently is One or more of the above;
n＝0～5；
the mass ratio of the anionic emulsifier to the nonionic emulsifier is 1-5: 5-15.
2. The method for preparing the composite emulsifier of claim 1, which is characterized by comprising the following steps:
1) mixing bifunctional epoxy resin, acid salt, a catalyst and a solvent, and carrying out polymerization reaction in an inert atmosphere to obtain an anionic emulsifier;
2) dripping the catalyst solution into a molten mixture of bifunctional epoxy resin and polyethylene glycol monomethyl ether for polymerization reaction to obtain a nonionic emulsifier;
3) and mixing the anionic emulsifier and the nonionic emulsifier to obtain the composite emulsifier.
3. The preparation method according to claim 2, wherein the mass ratio of the bifunctional epoxy resin, the acidic salt, the catalyst and the solvent in the step 1) is 25-200: 20-50: 0.05-0.5: 50-300; the temperature of the polymerization reaction is 100-160 ℃, and the time is 0.5-3 h.
4. The preparation method according to claim 2 or 3, wherein in the catalyst solution in the step 2), the mass ratio of the catalyst to the solvent is 0.05-0.5: 5-100, and the mass ratio of the catalyst, the bifunctional epoxy resin and the polyethylene glycol monomethyl ether is 0.05-0.5: 5-100: 50-350.
5. The preparation method according to claim 4, wherein the melting temperature of the molten mixture in the step 2) is 75-90 ℃, the temperature of the polymerization reaction is 100-160 ℃, and the time is 0.5-3 h; the dropping rate of the catalyst solution is 0.5-1.5 mL/min.
6. The preparation method according to claim 5, wherein the bifunctional epoxy resins in step 1) and step 2) independently comprise one or more of 1, 4-butanediol diglycidyl ether, neopentyl glycol diglycidyl ether, 1, 6-hexanediol diglycidyl ether, E51 epoxy resin, E44 epoxy resin, and E20 epoxy resin; the catalyst independently comprises one or more of triphenylphosphine, ethyltriphenylphosphine bromide, boron trifluoride diethyl etherate, boron trifluoride benzylamine complex, tetrabutylammonium bromide, dioctyl tin oxide, tin tetrachloride and tetraethylammonium iodide; the solvent independently contains one or more of N-methyl pyrrolidone, dimethyl sulfoxide, 1, 4-dioxane and N, N-dimethylformamide.
7. The method according to claim 5 or 6, wherein the acidic salt of step 1) comprises sodium p-hydroxybenzenesulfonate and/or sodium 3-carboxybenzenesulfonate; the molecular weight of the polyethylene glycol monomethyl ether in the step 2) is 2500-5000.
8. The aqueous epoxy resin emulsion containing the composite emulsifier of claim 1, characterized by comprising a hyperbranched epoxy-modified E51 resin, the composite emulsifier and water in a mass ratio of 100: 5-20: 85-95.
9. The method of preparing an aqueous epoxy resin emulsion according to claim 8, comprising the steps of:
1) melting the hyperbranched epoxy modified E51 resin and the composite emulsifier, and then blending to obtain a mixture;
2) adding water to the mixture to obtain a water-based epoxy resin emulsion;
the melting temperature in the step 1) is 50-70 ℃, and the time is 0.5-2 h; the blending temperature is 50-70 ℃, and the blending time is 0.5-1 h; the dropping rate of the step 2) is 0.5-1.5 mL/min.
10. The waterborne epoxy resin anticorrosive paint containing the waterborne epoxy resin emulsion of claim 8 is characterized by comprising the waterborne epoxy resin emulsion and an organic amine curing agent, wherein the ratio of epoxy equivalent in the waterborne epoxy resin emulsion to active hydrogen equivalent in the organic amine curing agent is 1-2: 1-2.
Technical Field
The invention relates to the technical field of emulsifiers, in particular to a composite emulsifier, a preparation method thereof, and a water-based epoxy resin emulsion and a coating containing the composite emulsifier.
Background
Epoxy resins are widely used in the fields of adhesives, coatings, electronic potting adhesives, aerospace and the like because of their excellent adhesion, dielectric resistance, electrical insulation and physical properties. Traditional solvent-based epoxy resins contain a large amount of VOCs, which are harmful to the ecological environment and the health of practitioners. In recent years, low-VOC or zero-VOC water-based epoxy coatings have been favored because of their advantages of non-flammability, non-toxicity, no odor, easy and convenient construction, no solvent emission, wide application range, and the like.
According to different preparation processes, the epoxy resin can be subjected to hydration by three methods: mechanical, phase inversion, self-emulsification. The self-emulsifying method is to carry out chemical modification on epoxy resin, hydrophilic groups are connected to the molecules of the epoxy resin, and at least two epoxy groups are reserved in each molecule. The mechanical method only needs to grind the epoxy resin, mix the epoxy resin with the emulsifier, and then add water under rapid stirring to form the water-based epoxy resin emulsion. The mechanical method is the simplest, but the prepared emulsion has large grain diameter and poor film forming performance. When the aqueous epoxy resin emulsion is prepared by the phase inversion method, the epoxy resin and the emulsifier are uniformly mixed under the shearing action, then distilled water is slowly added into the system, and the system is changed from water-in-oil to oil-in-water along with the increase of water amount. At the phase inversion point, a series of obvious changes occur in the physical properties of the system, such as reduced viscosity, reduced interfacial tension, smaller dispersed phase size and the like. The aqueous epoxy resin emulsion is prepared by a phase inversion method, and the average grain diameter of a dispersed phase can be about 1 um. If the emulsifier is a traditional surfactant, the emulsifier does not participate in the curing reaction of the resin, the emulsifier is easy to be separated out on the surface of a paint film after the resin is cured to influence the appearance and the corrosion resistance of the paint film, and the emulsion has poor stability; and the reactive emulsifier containing epoxy groups can participate in the curing reaction of the resin and become a part of a cross-linked molecular structure after curing, so that the influence on a paint film is small.
The prior art discloses that protonic acid is used for replacing Lewis acid as a catalyst to catalyze polyether polyol to react with epoxy resin to prepare an epoxy active emulsifier, and protonic acid remained in the active emulsifier is used for further catalyzing polymerization reaction of the active emulsifier and the epoxy resin to improve the stability of a water-based epoxy resin emulsion. However, protonic acid consumes a part of epoxy groups of the matrix resin, and the amount of the emulsifier is up to 23%, so that corrosion resistance and water resistance are greatly affected. The prior art also discloses that diamine reacts with sultone to introduce double-sulfonate ions, and then the generated secondary amine groups react with epoxy resin to obtain the double-anion emulsifier. The second step reaction of the method is the reaction of diamine and epoxy resin, the structure of the reaction product is uncontrollable, gel is easy to generate, and the uncertainty of the emulsification effect is increased, so that the effect can be achieved only by adding a large amount of emulsifier (20%), and a large amount of anions are introduced, thereby greatly influencing the water resistance of the coating film.
Therefore, the emulsifier with excellent performance is researched and developed, the product structure controllability of the water-based epoxy resin emulsion is further realized, the corrosion resistance, the water resistance, the storage stability and the emulsifying effect of the epoxy resin emulsion and the coating are improved, and the emulsifier has important value and significance.
Disclosure of Invention
The invention aims to overcome the defects of the prior art and provide a composite emulsifier, a preparation method thereof, and a water-based epoxy resin emulsion and a coating containing the composite emulsifier. The water-based epoxy resin emulsion prepared by the composite emulsifier has the excellent performances of small emulsifier dosage, small emulsion particle size, good storage stability and the like; the coating of the invention has excellent H resistance2SO4Corrosion performance and neutral salt spray resistance.
In order to achieve the above object, the present invention provides the following technical solutions:
the invention provides a composite emulsifier, which comprises a nonionic emulsifier and an anionic emulsifier;
the structural formula of the nonionic emulsifier is as follows:
n＝40～83；
the structural formula of the anionic emulsifier is as follows:
structural formula of the nonionic emulsifier and structural formula of the anionic emulsifierIndependently is
One or more of the above;
n＝0～5；
the mass ratio of the anionic emulsifier to the nonionic emulsifier is 1-5: 5-15.
The invention also provides a preparation method of the compound emulsifier, which comprises the following steps:
1) mixing bifunctional epoxy resin, acid salt, a catalyst and a solvent, and carrying out polymerization reaction in an inert atmosphere to obtain an anionic emulsifier;
2) dripping the catalyst solution into a molten mixture of bifunctional epoxy resin and polyethylene glycol monomethyl ether for polymerization reaction to obtain a nonionic emulsifier;
3) and mixing the anionic emulsifier and the nonionic emulsifier to obtain the composite emulsifier.
Preferably, the mass ratio of the bifunctional epoxy resin, the acidic salt, the catalyst and the solvent in the step 1) is 25-200: 20-50: 0.05-0.5: 50-300; the temperature of the polymerization reaction is 100-160 ℃, and the time is 0.5-3 h.
Preferably, in the catalyst solution in the step 2), the mass ratio of the catalyst to the solvent is 0.05-0.5: 5-100, and the mass ratio of the catalyst, the bifunctional epoxy resin and the polyethylene glycol monomethyl ether is 0.05-0.5: 5-100: 50-350.
Preferably, the melting temperature of the molten mixture in the step 2) is 75-90 ℃, the temperature of the polymerization reaction is 100-160 ℃, and the time is 0.5-3 h; the dropping rate of the catalyst solution is 0.5-1.5 mL/min.
Preferably, the difunctional epoxy resins in step 1) and step 2) independently comprise one or more of 1, 4-butanediol diglycidyl ether, neopentyl glycol diglycidyl ether, 1, 6-hexanediol diglycidyl ether, E51 epoxy resin, E44 epoxy resin and E20 epoxy resin; the catalyst independently comprises one or more of triphenylphosphine, ethyltriphenylphosphine bromide, boron trifluoride diethyl etherate, boron trifluoride benzylamine complex, tetrabutylammonium bromide, dioctyl tin oxide, tin tetrachloride and tetraethylammonium iodide; the solvent independently contains one or more of N-methyl pyrrolidone, dimethyl sulfoxide, 1, 4-dioxane and N, N-dimethylformamide.
Preferably, the acid salt in step 1) comprises sodium p-hydroxybenzenesulfonate and/or sodium 3-carboxybenzenesulfonate; the molecular weight of the polyethylene glycol monomethyl ether in the step 2) is 2500-5000.
The invention also provides a water-based epoxy resin emulsion containing the composite emulsifier, which comprises the hyperbranched epoxy modified E51 resin, the composite emulsifier and water in a mass ratio of 100: 5-20: 85-95.
The invention also provides a preparation method of the water-based epoxy resin emulsion, which comprises the following steps:
1) melting the hyperbranched epoxy modified E51 resin and the composite emulsifier, and then blending to obtain a mixture;
2) adding water to the mixture to obtain a water-based epoxy resin emulsion;
the melting temperature in the step 1) is 50-70 ℃, and the time is 0.5-2 h; the blending temperature is 50-70 ℃, and the blending time is 0.5-1 h; the dropping rate of the step 2) is 0.5-1.5 mL/min.
The invention also provides a water-based epoxy resin anticorrosive paint containing the water-based epoxy resin emulsion, which comprises the water-based epoxy resin emulsion and an organic amine curing agent, wherein the ratio of epoxy equivalent in the water-based epoxy resin emulsion to active hydrogen equivalent in the organic amine curing agent is 1-2: 1-2.
The beneficial effects of the invention include:
1) the composite emulsifier is a reaction product of bifunctionality epoxy resin and a monofunctional hydrophilic compound, and has a definite structure and a controllable emulsifying effect.
2) The compound emulsifier molecule of the invention contains epoxy group, can participate in curing reaction, and has excellent H resistance after emulsion film forming2SO4Corrosion performance and neutral salt spray resistance.
3) The water-based epoxy resin emulsion prepared by the composite emulsifier has the excellent performances of small emulsifier dosage (the emulsifier dosage is less than 10 percent in terms of epoxy resin), small emulsion particle size, good storage stability and the like.
Drawings
FIG. 1 is a nuclear magnetic hydrogen spectrum of the anionic emulsifier B of example 2;
FIG. 2 is a near-infrared spectrum of the anionic emulsifier B of example 2;
FIG. 3 is a graph showing the appearance of a water-borne epoxy anticorrosive paint formulated with emulsion J of example 10 after a 3000-hour neutral salt spray experiment.
Detailed Description
The invention provides a composite emulsifier, which comprises a nonionic emulsifier and an anionic emulsifier;
the structural formula of the nonionic emulsifier is as follows:
n＝40～83；
the structural formula of the anionic emulsifier is as follows:
structural formula of the nonionic emulsifier and structural formula of the anionic emulsifierIndependently is
One or more of the above;
n＝0～5；
the mass ratio of the anionic emulsifier to the nonionic emulsifier is 1-5: 5-15.
The nonionic emulsifier is preferably n-45-70, and more preferably n-55-60; the mass ratio of the anionic emulsifier to the nonionic emulsifier is preferably 2-4: 8-12, more preferably 3: 9-11, and even more preferably 3: 10.
The invention also provides a preparation method of the compound emulsifier, which comprises the following steps:
1) mixing bifunctional epoxy resin, acid salt, a catalyst and a solvent, and carrying out polymerization reaction in an inert atmosphere to obtain an anionic emulsifier;
2) dripping the catalyst solution into a molten mixture of bifunctional epoxy resin and polyethylene glycol monomethyl ether for polymerization reaction to obtain a nonionic emulsifier;
3) and mixing the anionic emulsifier and the nonionic emulsifier to obtain the composite emulsifier.
The mass ratio of the bifunctional epoxy resin, the acidic salt, the catalyst and the solvent in the step 1) is preferably 25-200: 20-50: 0.05-0.5: 50-300, more preferably 50-150: 30-40: 0.1-0.4: 100-230, and even more preferably 80-120: 33-35: 0.2-0.3: 150-200; the polymerization reaction temperature is preferably 100-160 ℃, more preferably 110-140 ℃, and even more preferably 120-130 ℃; the time of the polymerization reaction is preferably 0.5-3 h, more preferably 1-2 h, and even more preferably 1.5 h; the inert atmosphere is preferably nitrogen; the polymerization reaction is preferably carried out under stirring conditions.
In the catalyst solution in the step 2), the mass ratio of the catalyst to the solvent is preferably 0.05-0.5: 5-100, more preferably 0.1-0.4: 10-80, and even more preferably 0.2-0.3: 30-50; the mass ratio of the catalyst, the bifunctional epoxy resin and the polyethylene glycol monomethyl ether is preferably 0.05-0.5: 5-100: 50-350, more preferably 0.1-0.4: 15-80: 100-250, and even more preferably 0.2-0.3: 40-60: 150-200.
The melting temperature of the molten mixture in the step 2) of the invention is preferably 75-100 ℃, and more preferably 80-90 ℃; the polymerization reaction temperature is preferably 100-160 ℃, more preferably 110-150 ℃, and even more preferably 120-130 ℃; the time of the polymerization reaction is preferably 0.5-3 h, and more preferably 1-2 h; the dropping rate of the catalyst solution is preferably 0.5-1.5 mL/min, more preferably 0.8-1.2 mL/min, and even more preferably 1 mL/min.
The bifunctional epoxy resin in step 1) and step 2) of the present invention preferably independently comprises one or more of 1, 4-butanediol diglycidyl ether, neopentyl glycol diglycidyl ether, 1, 6-hexanediol diglycidyl ether, E51 epoxy resin, E44 epoxy resin, and E20 epoxy resin; when the bifunctional epoxy resin contains several components at the same time, the components are preferably mixed in an equal mass ratio; the catalyst preferably independently comprises one or more of triphenylphosphine, ethyltriphenylphosphine bromide, boron trifluoride diethyl etherate, boron trifluoride benzylamine complex, tetrabutylammonium bromide, dioctyl tin oxide, tin tetrachloride and tetraethylammonium iodide; when the catalyst contains several components at the same time, the components are preferably mixed in an equal mass ratio; the solvent preferably independently contains one or more of N-methyl pyrrolidone, dimethyl sulfoxide, 1, 4-dioxane and N, N-dimethylformamide; when the solvent contains several components at the same time, the components are preferably mixed in an equal mass ratio.
The acid salt in step 1) of the present invention preferably comprises sodium p-hydroxybenzenesulfonate and/or sodium 3-carboxybenzenesulfonate; when the sodium p-hydroxybenzenesulfonate and the sodium 3-carboxybenzenesulfonate are simultaneously contained, the two are preferably mixed in an equal mass ratio; the molecular weight of the polyethylene glycol monomethyl ether in the step 2) is preferably 2500-5000, more preferably 3000-4000, and even more preferably 3300-3500.
The preparation method of the composite emulsifier provided by the invention is a one-step method, is simple to operate, has wide raw material sources, and is suitable for large-scale industrial production.
The invention also provides a water-based epoxy resin emulsion containing the composite emulsifier, which comprises the hyperbranched epoxy modified E51 resin, the composite emulsifier and water in a mass ratio of 100: 5-20: 85-95.
In the aqueous epoxy resin emulsion, the mass ratio of the hyperbranched epoxy modified E51 resin to the composite emulsifier to water is preferably 100: 10-15: 88-92, and more preferably 100: 12-14: 90.
The hyperbranched epoxy modified E51 resin is preferably prepared by uniformly mixing EHBP1 epoxy resin and E51 epoxy resin at 75-85 ℃; the mass ratio of the EHBP1 epoxy resin to the E51 epoxy resin is 8-12: 88-92, and the preferred mass ratio is 10: 90; the preparation method of the EHBP1 epoxy resin is preferably that 286.32g of 1, 1' -bi-2-naphthol and 604.72g of trimethylolpropane triglycidyl ether are heated to 100 ℃ under the stirring condition, and a catalyst is added to react for 8 hours under the nitrogen atmosphere; the catalyst preferably comprises 0.08g tetrabutylammonium iodide and 0.04g ethyltriphenylphosphonium chloride.
The invention also provides a preparation method of the water-based epoxy resin emulsion, which comprises the following steps:
1) melting the hyperbranched epoxy modified E51 resin and the composite emulsifier, and then blending to obtain a mixture;
2) adding water to the mixture to obtain a water-based epoxy resin emulsion;
the melting temperature in the step 1) is 50-70 ℃, and the time is 0.5-2 h; the blending temperature is 50-70 ℃, and the blending time is 0.5-1 h; the dropping rate of the step 2) is 0.5-1.5 mL/min.
The melting temperature in the step 1) of the invention is preferably 55-65 ℃, and further preferably 60 ℃; the melting time is preferably 1-1.5 h; the blending temperature is preferably 55-65 ℃, and further preferably 60 ℃; the blending time is preferably 0.75 h; the blending is preferably carried out under the condition of stirring, and the stirring speed is preferably 1000-2000 r/min, more preferably 1200-1800 r/min, and even more preferably 1500 r/min.
The dripping speed in the step 2) of the invention is preferably 0.8-1.2 mL/min, and more preferably 1 mL/min; the aqueous epoxy resin emulsion is preferably obtained by filtration after completion of the water dropping.
The invention also provides a water-based epoxy resin anticorrosive paint containing the water-based epoxy resin emulsion, which comprises the water-based epoxy resin emulsion and an organic amine curing agent, wherein the ratio of epoxy equivalent in the water-based epoxy resin emulsion to active hydrogen equivalent in the organic amine curing agent is 1-2: 1-2.
The ratio of epoxy equivalent in the aqueous epoxy resin emulsion to active hydrogen equivalent in the organic amine curing agent is preferably 1: 1; color paste is preferably added into the water-based epoxy resin anticorrosive paint.
The technical solutions provided by the present invention are described in detail below with reference to examples, but they should not be construed as limiting the scope of the present invention.
Example 1
39.22g E51 epoxy resin (epoxy equivalent is 196), 19.62g of sodium p-hydroxybenzenesulfonate, 30g of N, N-dimethylformamide and 0.06g of ethyltriphenylphosphonium bromide are mixed, nitrogen is introduced, and the mixture reacts for 1h at 120 ℃ to obtain the anionic emulsifier A.
Example 2
45.45g E44 epoxy resin (epoxy equivalent is 227), 19.62g of sodium p-hydroxybenzenesulfonate, 30g N, N-dimethylformamide and 0.065g of boron trifluoride diethyl etherate are mixed, nitrogen is introduced, and the mixture reacts at 120 ℃ for 2 hours to obtain an anionic emulsifier which is recorded as an anionic emulsifier B.
FIG. 1 is a nuclear magnetic hydrogen spectrum of the anionic emulsifier B of example 2; FIG. 2 is a near-infrared spectrum of the anionic emulsifier B of example 2.
Example 3
105.26g of neopentyl glycol diglycidyl ether (epoxy equivalent of 148), 40g of sodium 3-carboxybenzenesulfonate, 100g N-methylpyrrolidone and 0.4g of tetrabutylammonium bromide were mixed, nitrogen gas was introduced, and a reaction was carried out at 150 ℃ for 1 hour to obtain an anionic emulsifier C.
Example 4
5.4g of 1, 4-butanediol diglycidyl ether (epoxy equivalent of 135) and 40g of polyethylene glycol monomethyl ether (molecular weight of 2500) were mixed, and the temperature was raised to 80 ℃ to give a molten mixture. 0.09g of boron trifluoride diethyl etherate was dissolved in 1.71g N-methylpyrrolidone, and the obtained catalyst solution was slowly dropped into the molten mixture to react at 100 ℃ for 2 hours, to obtain a nonionic emulsifier D.
Example 5
8g of neopentyl glycol diglycidyl ether (epoxy equivalent of 148) and 60g of polyethylene glycol monomethyl ether (molecular weight of 3000) were mixed, and the temperature was raised to 90 ℃ to obtain a molten mixture. 0.2g of boron trifluoride diethyl etherate was dissolved in 20g of dimethyl sulfoxide, and the obtained catalyst solution was slowly dropped into the molten mixture to react at 110 ℃ for 1.5 hours to obtain a nonionic emulsifier E.
Example 6
10g of 1, 6-hexanediol diglycidyl ether (epoxy equivalent of 151) and 70g of polyethylene glycol monomethyl ether (molecular weight of 3500) were mixed, and the temperature was raised to 85 ℃ to obtain a molten mixture. 0.15g of ethyl triphenyl phosphonium bromide is dissolved in 10g of 1, 4-dioxane, the obtained catalyst solution is slowly dripped into the molten mixture, and the reaction is carried out for 1h at 120 ℃ to obtain the nonionic emulsifier F.
Example 7
20g of E44 epoxy resin (epoxy equivalent 227) and 200g of polyethylene glycol monomethyl ether (molecular weight 5000) were mixed and the temperature was raised to 100 ℃ to give a molten mixture. 0.4G of boron trifluoride benzylamine complex is dissolved in 20G of N, N-dimethylformamide, the obtained catalyst solution is slowly dripped into the molten mixture, and the reaction is carried out for 1 hour at the temperature of 130 ℃ to obtain the nonionic emulsifier G.
Example 8
15g E51 epoxy resin (epoxy equivalent 196) and 150g of polyethylene glycol monomethyl ether (molecular weight 4000) were mixed and the temperature was raised to 100 ℃ to give a molten mixture. 0.12g of tin tetrachloride was dissolved in 5g of N-methylpyrrolidone, and the resulting catalyst solution was slowly dropped into the molten mixture to react at 150 ℃ for 0.5H, to obtain a nonionic emulsifier H.
Example 9
100g of hyperbranched epoxy modified E51 epoxy resin, 3g of anionic emulsifier B and 7g of nonionic emulsifier D are mixed and melted in an oven at 60 ℃ for 1 hour. And (3) mixing the molten product at 60 ℃ and at the rotating speed of 1500r/min for 0.5h, and then dripping 87g of deionized water at the speed of 1mL/min to obtain emulsion I.
Example 10
100g of hyperbranched epoxy modified E51 epoxy resin, 2g of anionic emulsifier B and 8g of nonionic emulsifier E are mixed and melted in an oven at 52 ℃ for 2 h. And (3) mixing the molten product at 52 ℃ and 1300r/min for 0.5h, and then dropwise adding 86g of deionized water at the speed of 1.2mL/min to obtain an emulsion J.
Example 11
100g of hyperbranched epoxy modified E51 epoxy resin, 2g of anionic emulsifier B and 9g of nonionic emulsifier F are mixed and melted in an oven at 55 ℃ for 1.5 h. And (3) mixing the molten product at 55 ℃ and at the rotating speed of 1400r/min for 0.5h, and then dropwise adding 90g of deionized water at the speed of 1.3mL/min to obtain the emulsion K.
Example 12
100G of hyperbranched epoxy modified E51 epoxy resin, 3G of anionic emulsifier B and 10G of nonionic emulsifier G are mixed and melted in an oven at 60 ℃ for 1 hour. And (3) mixing the molten product at 60 ℃ and at the rotating speed of 1500r/min for 0.5h, and then dropwise adding 92g of deionized water at the speed of 1.5mL/min to obtain emulsion L.
Example 13
100g of hyperbranched epoxy modified E51 epoxy resin, 4g of anionic emulsifier B and 10g of nonionic emulsifier H are mixed and melted in an oven at 65 ℃ for 0.5H. And (3) mixing the molten product at 65 ℃ and at a rotating speed of 1600r/min for 0.5h, and then dropwise adding 93g of deionized water at a speed of 1mL/min to obtain the emulsion M.
Example 14
100g of hyperbranched epoxy modified E51 epoxy resin, 3g of anionic emulsifier A and 7g of nonionic emulsifier D are mixed and melted in an oven at 60 ℃ for 1 hour. And (3) mixing the molten product at 60 ℃ and at the rotating speed of 1500r/min for 0.5h, and then dripping 87g of deionized water at the speed of 1.2mL/min to obtain emulsion N.
Example 15
100g of hyperbranched epoxy modified E51 epoxy resin, 2g of anionic emulsifier A and 8g of nonionic emulsifier E are mixed and melted in an oven at 53 ℃ for 2 h. And (3) mixing the molten product at 53 ℃ and at the rotating speed of 1600r/min for 0.5h, and then dropwise adding 86g of deionized water at the speed of 1mL/min to obtain emulsion O.
Example 16
100g of hyperbranched epoxy modified E51 epoxy resin, 2g of anionic emulsifier A and 7g of nonionic emulsifier F are mixed and melted in an oven at 55 ℃ for 1.5 h. And (3) mixing the molten product at 55 ℃ and at the rotating speed of 1400r/min for 0.5h, and then dropwise adding 90g of deionized water at the speed of 1.1mL/min to obtain the emulsion P.
Example 17
100G of hyperbranched epoxy modified E51 epoxy resin, 4G of anionic emulsifier A and 10G of nonionic emulsifier G are mixed and melted in an oven at 65 ℃ for 1 h. And (3) mixing the molten product at 65 ℃ and 1300r/min for 1h, and then dropwise adding 92g of deionized water at the speed of 1.3mL/min to obtain an emulsion Q.
Example 18
100g of hyperbranched epoxy modified E51 epoxy resin, 3g of anionic emulsifier A and 12g of nonionic emulsifier H are mixed and melted in an oven at 68 ℃ for 0.5H. And (3) mixing the molten product at 68 ℃ and a rotation speed of 1700R/min for 0.5h, and then dropwise adding 93g of deionized water at a speed of 1.5mL/min to obtain an emulsion R.
Comparative example 1
Emulsion S was obtained by replacing 3g of the anionic emulsifier B and 7g of the nonionic emulsifier D of example 9 with 3g of the anionic emulsifier CO-436 and 7g of the nonionic emulsifier LCN287 under the same conditions as in example 9.
Comparative example 2
Emulsion T was obtained by replacing 3g of the anionic emulsifier B and 7g of the nonionic emulsifier D of example 9 with 3g of the anionic emulsifier CO-436 and 10g of the nonionic emulsifier LCN287 under the same conditions as in example 9.
Comparative example 3
Emulsion U was obtained by replacing 3g of the anionic emulsifier B and 7g of the nonionic emulsifier D of example 9 with 3g of the anionic emulsifier SE-10N and 7g of the nonionic emulsifier LCN287 under the same conditions as in example 9.
Comparative example 4
Emulsion V was obtained by replacing 3g of the anionic emulsifier B and 7g of the nonionic emulsifier D of example 9 with 3g of the anionic emulsifier SE-10N and 10g of the nonionic emulsifier LCN287 under the same conditions as in example 9.
Comparative example 5
Emulsion W was obtained by replacing 3g of the anionic emulsifier B and 7g of the nonionic emulsifier D of example 9 with 10g of the anionic emulsifier A under the same conditions as in example 9.
Comparative example 6
Emulsion X was obtained by replacing 3g of the anionic emulsifier B and 7g of the nonionic emulsifier D of example 9 with 10g of the anionic emulsifier B under the same conditions as in example 9.
Comparative example 7
Emulsion Y was obtained by replacing 3g of the anionic emulsifier B and 7g of the nonionic emulsifier D of example 9 with 10g of the nonionic emulsifier D under the same conditions as in example 9.
Comparative example 8
Emulsion Z was obtained by replacing 3g of the anionic emulsifier B and 7g of the nonionic emulsifier D of example 9 with 10g of the nonionic emulsifier E under the same conditions as in example 9.
The particle size and storage stability of the aqueous epoxy resin emulsions of examples 9 to 18 and comparative examples 1 to 8 were measured, and the results are shown in Table 1.
And (3) particle size measurement: according to the mass ratio of 1: 500 the emulsions of examples 9 to 18 and comparative examples 1 to 8 were mixed with water, respectively, an appropriate amount of the mixture was dropped into a cuvette, the particle size was measured at 25 ℃ by a NanoZS nanometer particle size meter, and the average of the three measurements was taken as the particle size of the aqueous epoxy emulsion.
Storage stability: and packaging the filtered and discharged water-based epoxy resin emulsion in a clean plastic bottle, and placing at room temperature. And recording the experimental phenomenon when the appearance of the water-based epoxy emulsion is observed to change such as layering, emulsion breaking and the like.
The aqueous epoxy resin emulsions of examples 9 to 18 and comparative examples 1 to 8 were respectively cured with an aqueous polyamide curing agent (ratio of epoxy equivalent to active hydrogen equivalent is 1: 1) to form a film, which was cured at room temperature for 7 days and had a dry film thickness of 85. + -.10. mu.m. The salt spray resistance and the medium resistance of the dry film were tested, and the results are shown in table 2.
Salt spray resistance: according to the national standard GB/T1771-2007, the coatings prepared by the emulsions of the examples 9-18 and the comparative examples 1-8 are respectively sprayed on the two sides of a test plate, the test plate is obliquely placed in a salt spray box, the conditions of bubbling, rusting and the like on the surface of a paint film are observed, and the experimental phenomenon and time are recorded.
Medium resistance: the coatings prepared from the emulsions of examples 9 to 18 and comparative examples 1 to 8 were each double-side-sprayed onto test panels, which were placed in 3.5 wt% NaCl solution and 10 wt% H solution, respectively2SO4In the solution, 5 wt% NaOH solution and deionized water, observing whether foaming and rusting occur, and recording the experimental phenomenon and timeAnd (3) removing the solvent.
TABLE 1 Performance test results for waterborne epoxy resin emulsions
TABLE 2 Corrosion resistance test results of waterborne epoxy anticorrosive coatings
Emulsions for coatings
3.5% NaCl solution/h
10％H2SO4Solution/h
Neutral salt spray/h
Example 9
3336+
245
2980
Example 10
3336+
252
3000+
Example 11
3336+
224
2990
Example 12
3336+
197
2880
Example 13
3336+
180
2635
Example 14
3336+
185
2260
Example 15
3336+
194
2400
Example 16
3336+
190
2500
Example 17
3336+
181
2335
Example 18
3336+
170
2254
Comparative example 1
2130
76
1720
Comparative example 2
2011
72
1564
Comparative example 3
2410
106
1547
Comparative example 4
2552
117
1650
Note: + means that time is still increasing.
As can be seen from tables 1 and 2, the emulsifying effect is not good when the anionic emulsifier or the nonionic emulsifier is used alone; the emulsion prepared by using the traditional emulsifier has large particle size and poor stability; the aqueous epoxy resin emulsion prepared by compounding the anionic emulsifier and the nonionic emulsifier has the excellent performances of small emulsifier dosage, small emulsion particle size, good storage stability and the like; after the emulsion is cured into a film, the coating resists 10 percent H2SO4The solution can be more than 170h, the neutral salt spray resistance is more than 2200h, and the solution can be used in the field of heavy corrosion protection.
FIG. 3 is an appearance of the waterborne epoxy anticorrosive paint formulated with the emulsion J of example 10 after a 3000h neutral salt spray test, and it can be seen from FIG. 3 that the paint has no bubbles and rust spots and has excellent neutral salt spray resistance after the 3000h neutral salt spray test.
The foregoing is only a preferred embodiment of the present invention, and it should be noted that, for those skilled in the art, various modifications and decorations can be made without departing from the principle of the present invention, and these modifications and decorations should also be regarded as the protection scope of the present invention.