A water-based epoxy zinc-rich primer for transformers and a preparation method thereof
Patent Information
- Application Number
- CN202611094697.2
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2026-07-22
- Publication Date
- 2026-09-18
AI Technical Summary
[0005]本发明提出一种变压器用淋涂水性环氧富锌底漆及其制备方法，解决了相关技术中变压器用淋涂水性环氧富锌底漆形成的漆膜脆性大、韧性低、附着力不足的问题
本发明变压器用淋涂水性环氧富锌底漆中，使用二聚酸改性双酚A类环氧树脂乳液，与固化剂接触后能快速反应，但由于水的位隔效应，在水存在时反应缓慢，可以保证较长久的施工活化期，在淋涂完毕水分挥发之后，主剂固化剂活性单体会快速反应，从而在活化期和施工效率上完美结合。二聚酸改性双酚A类环氧树脂乳液的树脂结合强度高，可以提供涂层更好的附着力；流动性相对较差，一定的假塑性可以使锌粉保持悬浮性，使体系维持稳定性；有效改善了传统双酚A类环氧树脂的脆性大问题，具备良好的韧性和附着力。
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Abstract
Description
Technical Field
[0001] This invention relates to the field of coating preparation technology, specifically to a water-based epoxy zinc-rich primer for transformers and its preparation method. Background Technology
[0002] China's sustained and rapid economic development over the years has brought about enormous energy demand. The vast power transmission infrastructure requires long-term corrosion protection, creating a huge market demand. Transformers are crucial equipment for long-distance power transmission, and their outer walls require epoxy zinc-rich coating. Traditional solvent-based epoxy zinc-rich primers have become increasingly problematic due to their high VOC emissions and severe environmental pollution. Water-based epoxy zinc-rich primers, with their advantages of low VOCs and low pollution, are gradually becoming the mainstream in the industry.
[0003] However, currently available water-based epoxy zinc-rich primers for transformers generally suffer from high brittleness, low toughness, and insufficient adhesion, which limits their protective effect and service life. These problems not only lead to peeling and flaking of the paint film, leaving the transformer's metal substrate unprotected and directly exposed to a corrosive environment, accelerating substrate corrosion, reducing the structural strength of transformer components, and shortening equipment lifespan; the high brittleness and low toughness of the paint film also make it highly susceptible to cracking under minor impacts during transformer transportation and installation or under mechanical vibration during long-term operation. Corrosive media can penetrate to the substrate surface through these cracks, causing localized corrosion and even affecting the transformer's insulation performance, increasing the risk of power failure.
[0004] Therefore, it is very necessary to develop a water-based epoxy zinc-rich primer for transformers that combines excellent flexibility and high adhesion. Summary of the Invention
[0005] This invention proposes a water-based epoxy zinc-rich primer for transformers and its preparation method, which solves the problems of high brittleness, low toughness, and insufficient adhesion of the paint film formed by water-based epoxy zinc-rich primer for transformers in related technologies.
[0006] The technical solution of this invention is as follows: This invention proposes a water-based epoxy zinc-rich primer for transformers, comprising component A and component B. Component A comprises the following raw materials in parts by weight: 20-30 parts of water-based epoxy resin emulsion, 0.3-1 parts of anti-flash rust additive, 0.4-1 parts of defoamer, and 0.1-0.3 parts of rheology modifier. Component B comprises the following raw materials in parts by weight: 4-6 parts of co-solvent, 50-70 parts of zinc powder, 0.1-0.3 parts of dispersant, 0.1-0.3 parts of rheology modifier, and 4-6 parts of curing agent. The water-based epoxy resin emulsion is a dimer acid-modified bisphenol A epoxy resin emulsion.
[0007] As a further technical solution, the particle size of the zinc powder includes one or more of 325 mesh, 500 mesh, and 800 mesh, preferably 500 mesh.
[0008] As a further technical solution, the dimer acid modified bisphenol A epoxy resin emulsion includes one or both of EPD-172 and ERS-176.
[0009] As a further technical solution, the co-solvent includes one or more of the following: alcohol ester dodecyl, propylene glycol methyl ether, propylene glycol propyl ether, dipropylene glycol methyl ether, and ethylene glycol ethyl ether.
[0010] As a further technical solution, the dispersant includes one or more of polycarboxylic acid dispersants, polyurethane dispersants, and polyether dispersants.
[0011] As a further technical solution, the defoamer includes one or two of mineral oil defoamers and organosilicon defoamers.
[0012] As a further technical solution, the defoamer is composed of mineral oil defoamer and organosilicon defoamer in a mass ratio of 1:1.
[0013] The present invention uses a composite defoamer in the water-based epoxy zinc-rich primer for transformer coating. It has a long foam suppression time, strong acid and alkali resistance, good water miscibility, and combines the properties of two types of defoamers. When used in the zinc-rich primer coating for transformers, it can effectively suppress and defoam, prevent foaming of thick coatings, and has good foam suppression and defoaming durability, ensuring the appearance of the paint film during the mixed use period.
[0014] As a further technical solution, the flash rust inhibitor is a flash rust inhibitor that does not contain nitrates and complexates. The flash rust inhibitor includes carbazide and is composed of Halox Flash-x 330 and carbazide in a mass ratio of 1 to 2:1.
[0015] In this invention, the anti-flash rust additive in the water-based epoxy zinc-rich primer for transformers is a nitrate- and chelate-free anti-flash rust additive, and contains carbamate. Carbamate can act as an oxygen scavenger in water-based coatings. After the water-based coating is applied to the metal surface, it has a passivating effect on the metal surface, reducing the direct contact between the metal and oxygen, and thus slowing down the corrosion rate of the metal to a certain extent. Furthermore, the environmentally friendly anti-flash rust additive, which does not contain nitrates or chelates, can further provide good anti-flash rust protection for the metal surface, especially the submerged arc weld area, solving the problem of anti-flash rust in submerged arc welds using water-based coatings.
[0016] As a further technical solution, the curing agent includes one or two of aliphatic amine curing agents and polyamide curing agents.
[0017] As a further technical solution, the rheology modifiers in component A and component B each independently include one or two of polar modified bentonite and polyamide wax.
[0018] As a further technical solution, the polar modified bentonite is obtained by modifying bentonite with a polar modifier, which is composed of di(hydroxyethyl)methyldodecyl ammonium chloride and benzyldimethyl(2-hydroxyethyl)ammonium chloride in a mass ratio of 2~3:1.
[0019] In the water-based epoxy zinc-rich primer for transformers of this invention, polar modified bentonite is used, which can form hydrogen bonds with -OH groups, enhancing the thixotropic properties and anti-settling properties of the system. This ensures that the zinc powder remains in a suspended state at a low viscosity, thereby preventing zinc powder from settling and solving the problem of zinc powder settling in the system.
[0020] In the waterborne epoxy zinc-rich primer for transformers of this invention, the modifier of polar modified bentonite is composed of di(hydroxyethyl)methyldodecyl ammonium chloride and benzyldimethyl(2-hydroxyethyl)ammonium chloride. The molecular structures of the two modifiers work synergistically. The long carbon chain hydrophobic groups of di(hydroxyethyl)methyldodecyl ammonium chloride can form a steric hindrance effect between bentonite layers, improving the dispersion stability of modified bentonite in the waterborne epoxy system. The rigid benzyl structure of benzyldimethyl(2-hydroxyethyl)ammonium chloride can enhance the interaction between bentonite particles, further optimizing the thixotropic properties of the system. The combination of the two can not only construct a strong three-dimensional network structure, but also significantly improve the suspension stability of zinc powder, effectively preventing the sedimentation of zinc powder.
[0021] As a further technical solution, the preparation method of the polar modified bentonite includes the following steps: dispersing the polar modifier in a solvent, adding bentonite, mixing and drying to obtain polar modified bentonite.
[0022] As a further technical solution, the solvent is anhydrous ethanol, and the mass ratio of the anhydrous ethanol to the bentonite is 3:1.
[0023] As a further technical solution, the mixing time is 1 to 3 hours, preferably 2 hours.
[0024] As a further technical solution, the mass ratio of the polar modifier to the bentonite is 2:25.
[0025] This invention also proposes a method for preparing a water-based epoxy zinc-rich primer for transformers, comprising the following steps: S1. Stir the aqueous epoxy resin emulsion evenly, add the defoamer, add the anti-flash rust additive after the first stirring, add the rheology modifier after the second stirring, and obtain component A after the third stirring. S2. Stir the curing agent evenly, add the co-solvent, add the dispersant after the fourth stirring, add the zinc powder after the fifth stirring, add the rheology modifier after the sixth stirring, and obtain component B after the seventh stirring; S3. Mix component A and component B in a ratio of 2.6:1 until homogeneous, add water and stir until homogeneous to obtain the water-based epoxy zinc-rich primer for transformer coating.
[0026] As a further technical solution, in step S3, the amount of water added is 10% of the total mass of component A and component B.
[0027] As a further technical solution, in step S1, the stirring speed is 500 r / min.
[0028] As a further technical solution, the first stirring rate is 1000 r / min and the time is 10 min.
[0029] As a further technical solution, the second stirring rate is 500 r / min and the time is 10 min.
[0030] As a further technical solution, the third stirring rate is 1000 r / min and the time is 15 min.
[0031] As a further technical solution, in step S2, the stirring speed is 500 r / min.
[0032] As a further technical solution, the fourth stirring rate is 500 r / min and the time is 10 min.
[0033] As a further technical solution, the fifth stirring rate is 500 r / min and the time is 10 min.
[0034] As a further technical solution, the sixth stirring rate is 1000 r / min and the time is 10 min.
[0035] As a further technical solution, the seventh stirring rate is 1000 r / min and the time is 15 min.
[0036] The working principle and beneficial effects of this invention are as follows: This invention utilizes a dimer acid-modified bisphenol A epoxy resin emulsion in a water-based zinc-rich epoxy primer for transformers. This emulsion reacts rapidly upon contact with the curing agent, but due to the potential barrier effect of water, the reaction is slow in the presence of water, ensuring a longer activation period. After the water evaporates following coating, the active monomers of the main agent and curing agent react rapidly, thus achieving a perfect balance between activation period and construction efficiency. The dimer acid-modified bisphenol A epoxy resin emulsion exhibits high resin bonding strength, providing better coating adhesion; its relatively poor fluidity and certain pseudoplasticity allow the zinc powder to remain suspended, maintaining system stability; it effectively improves the brittleness problem of traditional bisphenol A epoxy resins, possessing good toughness and adhesion. Detailed Implementation
[0037] The technical solutions of the present invention will be clearly and completely described below with reference to the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.
[0038] Unless otherwise specified, the following embodiments and comparative examples are as follows: Waterborne epoxy resin emulsion: Dimer acid modified bisphenol A epoxy resin emulsion, model EPD-172; Zinc powder: 500 mesh particle size; Dispersant: Model DISPERBYK-190; Mineral oil defoamer: Model number FOAMASTER MO 2111; Organosilicon defoamer: Model number BYK-066N; Bentonite: Particle size 325 mesh; Polyamide wax: Model PA600.
[0039] Example 1 A water-based epoxy zinc-rich primer for transformers includes component A and component B. Component A comprises the following raw materials in parts by weight: 25 parts water-based epoxy resin emulsion, 0.7 parts anti-flash rust additive, 0.8 parts defoamer, and 0.2 parts rheology modifier. Component B comprises the following raw materials in parts by weight: 5 parts dodecyl alcohol ester, 63 parts zinc powder, 0.2 parts dispersant DISPERBYK-190, 0.2 parts rheology modifier, and 5 parts diethylenetriamine. The defoamer consists of mineral oil defoamer and silicone defoamer in a 1:1 mass ratio, the rheology modifier is polyamide wax, and the anti-flash rust additive consists of Halox Flash-x 330 and carbonyl hydrazine in a 1:1 mass ratio. A method for preparing a water-based epoxy zinc-rich primer for transformers includes the following steps: S1. Stir the waterborne epoxy resin emulsion evenly at a stirring speed of 500 r / min, add defoamer, stir at 1000 r / min for 10 min, add anti-flash rust additive, stir at 500 r / min for 10 min, add rheology modifier, stir at 1000 r / min for 15 min to obtain component A. S2. Stir the curing agent evenly at a stirring speed of 500 r / min, add alcohol ester twelve, stir at 500 r / min for 10 min, add dispersant, stir at 500 r / min for 10 min, add zinc powder, stir at 1000 r / min for 10 min, add rheology modifier, stir at 1000 r / min for 15 min to obtain component B; S3. Mix component A and component B evenly in a ratio of 2.6:1, add water and stir evenly. The amount of water added is 10% of the total mass of component A and component B; to obtain a water-based epoxy zinc-rich primer for transformer coating.
[0040] Example 2 A water-based epoxy zinc-rich primer for transformers includes component A and component B. Component A comprises the following raw materials in parts by weight: 20 parts water-based epoxy resin emulsion, 0.3 parts anti-flash rust additive, 0.4 parts defoamer, and 0.1 parts rheology modifier. Component B comprises the following raw materials in parts by weight: 4 parts dodecyl alcohol ester, 50 parts zinc powder, 0.1 parts dispersant DISPERBYK-190, 0.1 parts rheology modifier, and 4 parts diethylenetriamine. The defoamer consists of mineral oil defoamer and silicone defoamer in a 1:1 mass ratio, the rheology modifier is polyamide wax, and the anti-flash rust additive consists of Halox Flash-x 330 and carbonyl hydrazine in a 1:1 mass ratio. A method for preparing a water-based epoxy zinc-rich primer for transformers includes the following steps: S1. Stir the waterborne epoxy resin emulsion evenly at a stirring speed of 500 r / min, add defoamer, stir at 1000 r / min for 10 min, add anti-flash rust additive, stir at 500 r / min for 10 min, add rheology modifier, stir at 1000 r / min for 15 min to obtain component A. S2. Stir the curing agent evenly at a stirring speed of 500 r / min, add alcohol ester twelve, stir at 500 r / min for 10 min, add dispersant, stir at 500 r / min for 10 min, add zinc powder, stir at 1000 r / min for 10 min, add rheology modifier, stir at 1000 r / min for 15 min to obtain component B; S3. Mix component A and component B evenly in a ratio of 2.6:1, add water and stir evenly. The amount of water added is 10% of the total mass of component A and component B; to obtain a water-based epoxy zinc-rich primer for transformer coating.
[0041] Example 3 A water-based epoxy zinc-rich primer for transformers includes component A and component B. Component A comprises the following raw materials by weight: 30 parts water-based epoxy resin emulsion, 1 part anti-flash rust additive, 1 part defoamer, and 0.3 parts rheology modifier. Component B comprises the following raw materials by weight: 6 parts dodecyl alcohol ester, 70 parts zinc powder, 0.3 parts dispersant DISPERBYK-190, 0.3 parts rheology modifier, and 6 parts diethylenetriamine. The defoamer consists of mineral oil defoamer and silicone defoamer in a mass ratio of 1:1, the rheology modifier is polyamide wax, and the anti-flash rust additive consists of Halox Flash-x 330 and carbonyl hydrazine in a mass ratio of 2:1. A method for preparing a water-based epoxy zinc-rich primer for transformers includes the following steps: S1. Stir the waterborne epoxy resin emulsion evenly at a stirring speed of 500 r / min, add defoamer, stir at 1000 r / min for 10 min, add anti-flash rust additive, stir at 500 r / min for 10 min, add rheology modifier, stir at 1000 r / min for 15 min to obtain component A. S2. Stir the curing agent evenly at a stirring speed of 500 r / min, add alcohol ester twelve, stir at 500 r / min for 10 min, add dispersant, stir at 500 r / min for 10 min, add zinc powder, stir at 1000 r / min for 10 min, add rheology modifier, stir at 1000 r / min for 15 min to obtain component B; S3. Mix component A and component B evenly in a ratio of 2.6:1, add water and stir evenly. The amount of water added is 10% of the total mass of component A and component B; to obtain a water-based epoxy zinc-rich primer for transformer coating.
[0042] Example 4 The difference between Example 4 and Example 1 is that the flash rust inhibitor is only Halox Flash-x 330.
[0043] Example 5 The difference between Example 1 and Example 5 is that the polyamide wax is replaced with an equal amount of polar modified bentonite prepared by the following preparation method; The preparation method of polar modified bentonite includes the following steps: dispersing 2 parts of polar modifier in 75 parts of anhydrous ethanol, adding 25 parts of bentonite, mixing for 2 hours and then drying to obtain polar modified bentonite; the polar modifier is di(hydroxyethyl)methyldodecylammonium chloride.
[0044] Example 6 The difference between Example 6 and Example 5 is that the polar modifier is benzyldimethyl(2-hydroxyethyl)ammonium chloride.
[0045] Example 7 The difference between Example 7 and Example 5 is that the polar modifier is composed of di(hydroxyethyl)methyldodecyl ammonium chloride and benzyldimethyl(2-hydroxyethyl) ammonium chloride in a mass ratio of 2:1.
[0046] Example 8 The difference between Example 8 and Example 5 is that the polar modifier is composed of di(hydroxyethyl)methyldodecyl ammonium chloride and benzyldimethyl(2-hydroxyethyl) ammonium chloride in a mass ratio of 3:1.
[0047] Comparative Example 1 The difference between Comparative Example 1 and Example 1 is that the aqueous epoxy resin emulsion was replaced with an equal amount of E51 epoxy resin.
[0048] Experimental Example 1 The water-based epoxy zinc-rich primer for transformers prepared in Examples 1-3 and Comparative Example 1 was applied to the surface of Q235B cold-rolled steel sheet to form a paint film with a thickness of 50μm. The samples were tested according to the test methods specified in GB / T 5210-2006 "Adhesion Test of Paints and Varnishes by Pull-Off Method" and GB / T 1731-2020 "Determination of Flexibility of Paint Films and Putty Films".
[0049] The test results are shown in Table 1: Table 1 Performance test results of Examples 1-3 and Comparative Example 1
[0050] As shown in Table 1, when dimer acid-modified bisphenol A epoxy resin emulsion is added, the resulting water-based epoxy zinc-rich primer for transformer coating has better flexibility and stronger adhesion.
[0051] Experimental Example 2 The water-based epoxy zinc-rich primer for transformers prepared in Examples 1 and 4 was applied to the surface of Q235B cold-rolled steel plate to form a paint film with a thickness of 50μm. The sample was tested according to the test method in GB / T 5210-2006 "Paints and Varnishes - Pull-off Adhesion Test".
[0052] The test results are shown in Table 2: Table 2 Performance test results of Examples 1 and 4
[0053] As shown in Table 2, when the anti-flash rust additive of water-based epoxy zinc-rich primer for transformers contains carbonyl hydrazine, it can improve the water resistance of the coating and the anti-flash rust of submerged arc welding.
[0054] Experimental Example 3 The water-based epoxy zinc-rich primer for transformers prepared in Examples 1 and 5-8 was diluted to 23s and the viscosity was tested before and after 12 hours. The viscosity change rate was calculated as follows: viscosity change rate = (final viscosity - initial viscosity) / initial viscosity × 100%.
[0055] The test results are shown in Table 3: Table 3 Performance test results of Examples 1 and 5-8
[0056] As shown in Table 3, when the polar modifier of polar modified bentonite is composed of di(hydroxyethyl)methyldodecylammonium chloride and benzyldimethyl(2-hydroxyethyl)ammonium chloride, the sedimentation of zinc powder can be further prevented.
[0057] The above are merely preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.
Claims
1. A water-based epoxy zinc-rich primer for transformers, characterized in that, The product comprises component A and component B. Component A includes the following raw materials in parts by weight: 20-30 parts of waterborne epoxy resin emulsion, 0.3-1 part of anti-flash rust additive, 0.4-1 part of defoamer, and 0.1-0.3 parts of rheology modifier. Component B includes the following raw materials in parts by weight: 4-6 parts of cosolvent, 50-70 parts of zinc powder, 0.1-0.3 parts of dispersant, 0.1-0.3 parts of rheology modifier, and 4-6 parts of curing agent. The waterborne epoxy resin emulsion is a dimer acid modified bisphenol A type epoxy resin emulsion.
2. The water-based epoxy zinc-rich primer for transformers according to claim 1, characterized in that, The dimer acid modified bisphenol A epoxy resin emulsion includes one or both of EPD-172 and ERS-176.
3. The water-based epoxy zinc-rich primer for transformers according to claim 1, characterized in that, The co-solvent includes one or more of the following: dodecyl alcohol ester, propylene glycol methyl ether, propylene glycol propyl ether, dipropylene glycol methyl ether, and ethylene glycol ethyl ether.
4. The water-based epoxy zinc-rich primer for transformers according to claim 1, characterized in that, The dispersant includes one or more of polycarboxylic acid dispersants, polyurethane dispersants, and polyether dispersants.
5. The water-based epoxy zinc-rich primer for transformers according to claim 1, characterized in that, The defoamer includes one or both of mineral oil defoamers and organosilicon defoamers.
6. A water-based epoxy zinc-rich primer for transformers according to claim 1, characterized in that, The flash rust inhibitor is a flash rust inhibitor that does not contain nitrates and complexates. The flash rust inhibitor includes carbazide and is composed of Halox Flash-x 330 and carbazide in a mass ratio of 1 to 2:
1.
7. The water-based epoxy zinc-rich primer for transformers according to claim 1, characterized in that, The curing agent includes one or both of aliphatic amine curing agents and polyamide curing agents.
8. The water-based epoxy zinc-rich primer for transformers according to claim 1, characterized in that, The rheology modifiers in component A and component B each independently include one or both of polar modified bentonite and polyamide wax.
9. A water-based epoxy zinc-rich primer for transformers according to claim 8, characterized in that, The polar modified bentonite is obtained by modifying bentonite with a polar modifier, which is composed of di(hydroxyethyl)methyldodecyl ammonium chloride and benzyldimethyl(2-hydroxyethyl)ammonium chloride in a mass ratio of 2~3:
1.
10. A method for preparing a water-based epoxy zinc-rich primer for transformers, used to prepare the water-based epoxy zinc-rich primer for transformers as described in any one of claims 1 to 9, characterized in that, Includes the following steps: S1. Stir the aqueous epoxy resin emulsion evenly, add the defoamer, add the anti-flash rust additive after the first stirring, add the rheology modifier after the second stirring, and obtain component A after the third stirring. S2. Stir the curing agent evenly, add the co-solvent, add the dispersant after the fourth stirring, add the zinc powder after the fifth stirring, add the rheology modifier after the sixth stirring, and obtain component B after the seventh stirring; S3. Mix component A and component B in a ratio of 2.6:1 until homogeneous, add water and stir until homogeneous to obtain the water-based epoxy zinc-rich primer for transformer coating.