Quick-drying double-component waterborne epoxy zinc-rich primer as well as preparation method and application thereof

Abstract

The invention discloses a quick-drying double-component waterborne epoxy zinc-rich primer as well as a preparation method and application thereof. The component A is prepared from the following raw materials in parts by weight: 10 to 20 parts of waterborne epoxy resin, 38 to 88 parts of zinc powder and 0.01 to 50 parts of ferrophosphorus powder; and the component B comprises 5-40 parts of a waterborne epoxy curing agent, 10-60 parts of deionized water and 2-75 parts of an acrylic polymer emulsion. By introducing the acrylic polymer emulsion with quick-drying performance, the drying time of the two-component waterborne epoxy zinc-rich primer is greatly shortened, and the acrylic polymer emulsion has a special compound emulsifier structure, so that the acrylic polymer emulsion can maintain stability in the waterborne epoxy zinc-rich primer with high cosolvent content; the waterborne epoxy resin can be fully emulsified in the paint distribution and mixing process of the waterborne epoxy zinc-rich primer component A, and the compatibility of the waterborne epoxy resin and the waterborne epoxy zinc-rich primer component A is improved, so that the paint film performance is improved, and the salt mist resistance and the corrosion resistance of the epoxy zinc-rich primer are prevented from being greatly reduced.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of industrial anticorrosive coatings, in particular to a fast-drying two-component waterborne epoxy zinc-rich primer, and a preparation method and application thereof. BACKGROUND

[0002] Waterborne coatings have obtained rapid development due to their environmental friendliness, low VOCs, non-flammability and non-explosiveness. Among them, two-component waterborne epoxy zinc-rich primer is often used as the first coating layer on rough steel surfaces treated by sandblasting or shot blasting, and plays an anticorrosive role as an anode due to the lower electrode potential of zinc than that of iron. At present, the research on two-component waterborne epoxy zinc-rich primer is mainly focused on the influence of the content, form, particle size, modification of zinc powder, and the addition of fillers and conductive fillers to replace zinc powder on the protective performance of the coating.

[0003] However, in actual engineering applications, in order to improve the coating efficiency and reduce the coating cost, the construction period of the two-component waterborne epoxy zinc-rich primer is required to be shorter and shorter, i.e. the primer needs to be able to be coated in the next step in a short time (such as 3-5 hours at room temperature) after the primer construction. However, the reaction speed of the two components of the traditional two-component waterborne epoxy zinc-rich primer is limited by the environmental temperature and humidity, and the primer usually needs to be dried for more than 12 hours before recoating under self-drying conditions, and the drying time is even longer in a low-temperature environment, which seriously affects the coating efficiency.

[0004] Therefore, it is of great significance to reduce the drying time of the two-component waterborne epoxy zinc-rich primer under self-drying conditions without affecting the salt spray resistance and anticorrosive performance of the epoxy zinc-rich primer, so as to improve the engineering construction efficiency. SUMMARY

[0005] The present application aims to overcome the above technical deficiencies, and provides a fast-drying two-component waterborne epoxy zinc-rich primer, a preparation method and application thereof, which solve the technical problems of long self-drying time and low coating efficiency of the traditional two-component waterborne epoxy zinc-rich primer in the prior art.

[0006] In a first aspect, the present application provides a fast-drying two-component waterborne epoxy zinc-rich primer, which comprises A component and B component; wherein, in terms of weight parts, the A component comprises: 10-20 parts of waterborne epoxy resin, 38-88 parts of zinc powder, and 0.01-50 parts of phosphorus-iron powder; and the B component comprises: 5-40 parts of waterborne epoxy curing agent, 10-60 parts of deionized water, and 2-75 parts of acrylic polymer emulsion; the acrylic polymer emulsion is prepared by emulsion polymerization, and a composite emulsifier composed of an anionic emulsifier and a non-ionic emulsifier is used as the emulsifier in the emulsion polymerization process.

[0007] In a second aspect, the present application provides a preparation method of the fast-drying two-component waterborne epoxy zinc-rich primer, which comprises the following steps: S1, uniformly mix the raw materials of the A component to obtain the A component; S2, uniformly mix the raw materials of the B component to obtain the B component; S3, uniformly mix the A component and the B component to obtain the quick-drying two-component waterborne epoxy zinc-rich primer.

[0008] In a third aspect, the application provides a use of the quick-drying two-component waterborne epoxy zinc-rich primer, which is applied to mechanical equipment and bridge steel structures.

[0009] Compared with the prior art, the application has the following beneficial effects: In the application, the introduction of the acrylic polymer emulsion with quick-drying performance into the B component of the waterborne epoxy zinc-rich primer greatly reduces the drying time of the two-component waterborne epoxy zinc-rich primer. Due to the special complex emulsifier structure of the acrylic polymer emulsion, the acrylic polymer emulsion can maintain stability in the waterborne epoxy zinc-rich primer with a high content of solubilizing agent, can fully emulsify the waterborne epoxy resin during the mixing of the A component and the B component of the waterborne epoxy zinc-rich primer, and can improve the compatibility of the two components, thereby improving the film performance, and avoiding a significant reduction in the salt mist resistance and corrosion resistance of the epoxy zinc-rich primer. DETAILED DESCRIPTION

[0010] In order to make the purpose, technical scheme and advantages of the application clearer, the application will be further described in detail below with reference to the embodiments. It should be understood that the specific embodiments described herein are only used to explain the application and not to limit the application.

[0011] The zinc-rich primer has the maximum characteristics of high salt mist resistance and high corrosion resistance, has excellent adhesion of the epoxy resin, and has good alkali resistance, and is most suitable for use as a carrier of zinc powder. The epoxy zinc-rich primer is commonly prepared by using an epoxy resin in the industry. The existing waterborne epoxy zinc-rich primer is usually prepared in two ways: (1) using an epoxy curing agent containing a hydrophilic group but without water as a carrier of zinc powder, and using other pigments, fillers and additives as a main agent A component, and using a water-containing epoxy emulsion as a B component, and mixing the A and B components uniformly during construction (referred to as a curing agent plus zinc powder); (2) using an epoxy resin as a carrier of zinc powder, introducing a hydrophilic group into the epoxy resin, and using the epoxy resin without water, zinc powder, other pigments, fillers and additives as a main agent A component, and using a waterborne water-containing epoxy curing agent as a B component, and mixing the A and B components uniformly during construction (referred to as an epoxy resin plus zinc powder). However, in the above two ways, the drying time of the paint film is relatively long under the self-drying condition, and the next coating layer cannot be applied until the next day. Even if an epoxy drying agent is added, due to the low reaction speed of the two components under the room temperature self-drying condition, it is also difficult to meet the requirement of applying the next coating layer under room temperature for 3-5h.

[0012] The acrylic polymer emulsion generally has fast water and solvent release, does not need chemical reaction crosslinking to form film, has the advantage of fast drying time, but it often contains a large amount of amine neutralizer (DMEA), since the active hydrogen in the amine neutralizer will react with the epoxy resin, and the waterborne epoxy curing agent will not react with the amine neutralizer, therefore, the inventors consider adopting the second epoxy resin plus zinc powder paint preparation method, adding the acrylic polymer emulsion in the waterborne epoxy curing agent B component, in order to solve the technical problems of long self-drying time and low coating efficiency of the traditional two-component waterborne epoxy zinc-rich primer. However, according to the traditional theory and practical experience, after introducing the acrylic polymer emulsion, the single-component acrylic polymer emulsion with fast dryness will significantly reduce the salt fog resistance and corrosion resistance of the epoxy zinc-rich primer, since the film density and adhesion of the acrylic polymer emulsion are not as good as those of the epoxy resin, the formed epoxy zinc-rich primer has improved drying performance, but its most important corrosion resistance is significantly reduced, which cannot meet the actual demand. The inventors have surprisingly found, through a large number of experiments, that the acrylic polymer emulsion with the characteristics of composite emulsifier (anionic emulsifier + non-ionic emulsifier) has good compatibility with the epoxy resin, since the special emulsifier structure is helpful for the emulsification of the A component during the mixing process, and it is easy to realize the phase inversion from the oil phase to the water phase, thereby improving the coating performance. Specifically, since the solvent content of the A component is high and the zinc powder is alkaline, the curing agent B component modified by the acrylic polymer emulsion with a single emulsifier system is prone to lose stability under the influence of a large amount of solvent and alkalinity, precipitates, becomes coarse, and forms particles, thereby causing a significant decrease in salt fog resistance. The curing agent B component modified by the acrylic polymer emulsion with a composite emulsifier system has good stability when mixed with the A component, does not cause precipitation and coarsening, and has relatively small influence on the salt fog resistance. Moreover, the acrylic polymer emulsion has faster drying time than the epoxy resin system, which can significantly improve the drying time of the film, and even meet the 3-5h recoating time under self-drying conditions. At the same time, since the acrylic polymer emulsion generally has lower surface tension than the epoxy resin emulsion, it exhibits better substrate wettability, has better wettability for the high-roughness metal substrate treated by sandblasting for the zinc-rich primer coating, reduces the air remaining in the micropores of the rough metal surface, makes the zinc powder fully contact with the metal substrate, and improves the utilization efficiency of the zinc powder as the anode sacrifice.

[0013] Based on this, the present application is proposed.

[0014] In a first aspect, the present application provides a fast-drying two-component waterborne epoxy zinc-rich primer, which raw materials include component A and component B; wherein, in terms of weight parts, component A includes: 10-20 parts of waterborne epoxy resin, 38-88 parts of zinc powder, and 0.01-50 parts of phosphorus iron powder; component B includes: 5-40 parts of waterborne epoxy curing agent, 10-60 parts of deionized water, and 2-75 parts of acrylic polymer emulsion.

[0015] In the present application, by introducing the acrylic polymer emulsion with fast-drying performance into the component B of the waterborne epoxy zinc-rich primer, the drying time of the two-component waterborne epoxy zinc-rich primer is greatly reduced, and due to the special composite emulsifier structure of the acrylic polymer emulsion, it can also maintain stability in the waterborne epoxy zinc-rich primer with high content of cosolvent, fully emulsify the waterborne epoxy resin during the mixing process of the component A of the waterborne epoxy zinc-rich primer, improve the compatibility of the two, thereby improving the film performance and avoiding the significant reduction of the salt fog resistance and corrosion resistance of the epoxy zinc-rich primer.

[0016] In the present embodiment, the waterborne epoxy resin is a water-free resin system obtained by hydrophilic modification of one or more of E51, E44, E20, E12, etc., and then dilution with a hydrophilic organic solvent (such as propylene glycol methyl ether, ethylene glycol butyl ether, etc.). The present application does not limit the specific model of the waterborne epoxy resin, and those skilled in the art can select according to the actual situation. For example, the model of the waterborne epoxy resin can be Shanghai Huayi STW600, STW600H, STW600L, or Wuxi Honghui AERS6075, etc.

[0017] Preferably, the mass solid content of the waterborne epoxy resin is 70%-80%.

[0018] In the present embodiment, the zinc powder is a general commercially available product. The present application does not limit the specific model of the zinc powder, and those skilled in the art can select according to the actual situation. For example, the zinc powder can be Hunan Xinweiling Zinc Corrosion Resistant Coating Special Zinc Powder, etc.

[0019] In the present embodiment, the phosphorus iron powder is a general commercially available product. The present application does not limit the specific model of the phosphorus iron powder, and those skilled in the art can select according to the actual situation. For example, the phosphorus iron powder can be Anhui Yinao Pigment QES506 Phosphorus Iron Powder, etc.

[0020] In the present embodiment, the waterborne epoxy curing agent is an amine curing agent, including but not limited to one or more of aliphatic amine, alicyclic amine, aromatic amine, and polyamide. The present application does not limit the specific model of the waterborne epoxy curing agent, and those skilled in the art can select according to the actual situation. For example, the waterborne epoxy curing agent can be Huntsman AD38-1, or Shanghai Huayi STW703C, STW703D, or Tongde 3EC153W, 3EC154W, etc.

[0021] Preferably, the mass solid content of the aqueous epoxy curing agent is 75%-85%.

[0022] In the embodiment, the acrylic polymer emulsion is prepared by an emulsion polymerization reaction, and a composite emulsifier composed of an anionic emulsifier and a non-ionic emulsifier is used as the emulsifier in the emulsion polymerization reaction. The anionic emulsifier can be sodium dodecyl sulfate, sodium fatty alcohol polyoxyethylene ether sulfate, sodium dodecyl benzene sulfonate, succinate sulfonate, fatty alcohol polyoxyethylene ether phosphate, allyloxy hydroxypropyl sulfonate, etc.; and the non-ionic emulsifier can be alkyl phenol polyoxyethylene ether, fatty alcohol polyoxyethylene ether, fatty acid polyoxyethylene ester, allyl polyoxyethylene ether, etc. Different from the acrylic polymer emulsion prepared by a traditional single emulsifier (such as a single anionic emulsifier), the acrylic polymer emulsion selected in the embodiment has the composite emulsifier characteristics of the anionic emulsifier and the non-ionic emulsifier, and can provide wider formulation applicability and better stability under harsh conditions such as alkaline conditions and high solvent content. The specific type of the acrylic polymer emulsion selected in the embodiment is not limited, and a person skilled in the art can select it according to the actual situation. For example, the acrylic polymer emulsion can be Hebei Hengshui Xinguang Chemical XG-2391, XG-9102, etc.

[0023] Preferably, the mass solid content of the acrylic polymer emulsion is 40%-50%.

[0024] In the embodiment, the A component further includes one or more of a film-forming aid I, a cosolvent, an anti-settling agent, an antifoaming agent, a wetting agent, and a silane coupling agent.

[0025] In the embodiment, the B component further includes one or more of a film-forming aid II and an anti-tarnish agent.

[0026] Preferably, the film-forming aid I and the film-forming aid II are one or more of dipropylene glycol butyl ether, benzyl alcohol, propylene glycol phenyl ether, and alcohol ester twelve.

[0027] Preferably, the cosolvent is one or more of isopropyl alcohol, ethylene glycol butyl ether, diethylene glycol butyl ether, propylene glycol methyl ether, dipropylene glycol methyl ether, and propylene glycol ethyl ether.

[0028] Preferably, the anti-settling agent is one or more of polyamide wax, organically modified bentonite, hydrated magnesium aluminum silicate, and fumed silica. The specific type of the anti-settling agent is not limited, and a person skilled in the art can select it according to the actual situation. For example, the type of the polyamide wax can be Nanjing Tianshi NEW-0451, etc., the type of the fumed silica can be De Gussa A200, A380, etc., and the type of the organically modified bentonite can be Himmels Flocan LT, EW, etc.

[0029] Preferably, the defoaming agent is one or more of mineral oil defoaming agent, silicone defoaming agent, and polymer defoaming agent. It should be noted that in the paint industry, the polymer defoaming agent generally refers to polyether, polyacrylate, polyurethane and other polymers without silicone polymers. The specific model of the defoaming agent is not limited in the present application, and the person skilled in the art can select according to the actual situation. For example, the model of the defoaming agent can be Germany Tego810, Tego901W, Germany BYK-011, etc.

[0030] Preferably, the wetting agent is one or more of silicone wetting agent, acetylenic diol wetting agent, and fluorocarbon wetting agent. The specific model of the wetting agent is not limited in the present application, and the person skilled in the art can select according to the actual situation. For example, the wetting agent can be Germany Tego270, Tego280, etc.

[0031] Preferably, the silane coupling agent is a silane oligomer with an epoxy end group modification. The specific model of the silane coupling agent is not limited in the present application, and the person skilled in the art can select according to the actual situation. For example, the silane coupling agent can be MP200 of MEGUPT, LD-3168 of Yangzhou Lida Chemical Industry Co., Ltd., etc.

[0032] Preferably, the anti-flash rust agent is an aqueous solution of sodium nitrite or organic acid salt. The specific model of the anti-flash rust agent is not limited in the present application, and the person skilled in the art can select according to the actual situation. For example, the anti-flash rust agent can be one or more of ASCOTEC H10, H14, H18 of Shanghai Yujie, or FA179 of Hymns.

[0033] In the present embodiment, the A component includes: water-based epoxy resin 13-17 parts by weight, zinc powder 60-80 parts by weight, and phosphorus iron powder 1-10 parts by weight; the B component includes: water-based epoxy curing agent 10-20 parts by weight, deionized water 10-30 parts by weight, and acrylic polymer emulsion 45-65 parts by weight.

[0034] In the present embodiment, the A component includes: water-based epoxy resin 10-20 parts by weight, film-forming aid I 1-5 parts by weight, cosolvent 0.1-13 parts by weight, anti-settling agent 0.2-2 parts by weight, defoaming agent 0.05-0.5 parts by weight, wetting agent 0.05-0.5 parts by weight, zinc powder 38-88 parts by weight, phosphorus iron powder 0.01-50 parts by weight, and silane coupling agent 0.1-3 parts by weight; the B component includes: water-based epoxy curing agent 5-40 parts by weight, deionized water 10-60 parts by weight, acrylic polymer emulsion 2-75 parts by weight, film-forming aid II 0.1-10 parts by weight, and anti-flash rust agent 0.5-10 parts by weight.

[0035] In the embodiment, the A component includes, by weight parts, water-based epoxy resin 13-17 parts, film-forming aid I 1-5 parts, cosolvent 2-10 parts, anti-settling agent 0.5-2 parts, defoaming agent 0.05-0.5 parts, wetting agent 0.05-0.5 parts, zinc powder 60-80 parts, phosphorus iron powder 1-10 parts, silane coupling agent 0.3-3 parts; the B component includes water-based epoxy curing agent 10-20 parts, deionized water 10-30 parts, acrylic polymer emulsion 45-65 parts, film-forming aid II 1-10 parts, anti-flash rust agent 1-5 parts.

[0036] In the embodiment, the solid content of the acrylic polymer emulsion accounts for 30%-50% of the total mass of the solid content of the water-based epoxy resin and the water-based epoxy curing agent. The inventors have further found through neutral salt spray test and continuous condensation test that by adding the acrylic polymer emulsion with the composite emulsifier characteristics in an appropriate amount, the salt fog resistance and corrosion resistance of the two-component water-based epoxy zinc-rich primer can be further improved while the dryness of the two-component water-based epoxy zinc-rich primer is improved, so that the construction performance and corrosion resistance are simultaneously improved.

[0037] In the embodiment, the fast-drying two-component water-based epoxy zinc-rich primer has a pigment-to-binder ratio (i.e., the ratio of the total mass of pigments and fillers to the total mass of the solid content of the water-based epoxy resin, the water-based epoxy curing agent and the acrylic polymer emulsion) of (3.5-4.5):1, and further 4:1.

[0038] In the embodiment, the mass ratio of the A component to the B component is 100:(10-30), further 100:(15-25), and more further 100:(18-21).

[0039] In a second aspect, the application provides a preparation method of a fast-drying two-component water-based epoxy zinc-rich primer, which includes the following steps: S1, uniformly mixing raw materials of the A component to obtain the A component; S2, uniformly mixing raw materials of the B component to obtain the B component; S3, uniformly mixing the A component and the B component to obtain the fast-drying two-component water-based epoxy zinc-rich primer.

[0040] In the embodiment, step S1 includes: S11, adding the water-based epoxy resin, the film-forming aid I and the cosolvent into a first container, starting stirring, adding the anti-settling agent at 500-600 rpm, adjusting the stirring speed to 800-1000 rpm after the addition is completed, and high-speed dispersing for 5-10 min until uniform without lumps; S12, reduce the speed to 500-600rpm, add defoaming agent and wetting agent in turn, disperse for 5-10min, then add zinc powder and phosphorus iron powder in turn, adjust the speed to 800-1000rpm after adding, disperse at high speed, start timing when the temperature rises to 50℃, maintain 50-60℃ for 20-30min; S13, check the fineness to reach below 60μm, reduce the speed to 300-500rpm, add cosolvent to make up the solvent volatilization in the dispersion process, then add silane coupling agent and continue stirring for 10-20min, adjust the viscosity to be qualified, then filter to obtain component A.

[0041] Preferably, the viscosity is adjusted by cosolvent until the 30℃ stoker viscosity of the mixture of component A and component B is 110-130KU.

[0042] Preferably, 30-50 mesh filter cloth is used for filtration.

[0043] In the embodiment, step S2 comprises: S21, put the water-based epoxy curing agent and deionized water into the second container, stir at 500-600rpm for 10-20min to make them fully mixed and uniform; S22, keep stirring, add acrylic polymer emulsion, fully stir for 20-30min, then slowly add film forming aid II and anti-flash rust agent in turn, continue stirring for 20-30min to obtain component B.

[0044] In a third aspect, the application provides an application of the quick-drying two-component water-based epoxy zinc-rich primer, which is applied to mechanical equipment and bridge steel structure.

[0045] Example 1 A preparation method of a quick-drying two-component water-based epoxy zinc-rich primer comprises the following steps: (1) Put 18.3 parts of STW600 waterborne epoxy resin (mass solid content 75%), 2 parts of dipropylene glycol butyl ether film forming aid I, 1 part of propylene glycol methyl ether cosolvent I and 4.1 parts of ethylene glycol butyl ether cosolvent II into a dispersion cylinder, start stirring, slowly add 0.6 parts of NEW-0451 anti-settling agent I and 0.6 parts of A200 anti-settling agent II at 600 rpm, after adding, adjust the speed to 1000 rpm and disperse for 10 minutes until uniform and no lumps; reduce the speed to 600 rpm, add 0.1 parts of Tego810 defoamer and 0.1 parts of Tego270 wetting agent in turn, disperse for 10 minutes, then add 66.8 parts of zinc-rich anticorrosive coating special zinc powder and 5.4 parts of QES506 phosphorus iron powder in turn, after adding, adjust the speed to 1000 rpm and disperse at high speed, measure the temperature of the material while dispersing, start timing when the temperature rises to 50℃, maintain 50-60℃ for 30 minutes; check the fineness to reach below 60μm, reduce the speed to 500 rpm, and add appropriate amount of ethylene glycol butyl ether to supplement the solvent volatilization during dispersion according to the actual situation, and add 1 part of LD-3168 silane coupling agent and continue stirring for 20 minutes, adjust the viscosity to qualified (Stomer viscosity of A+B component mixture is 110-130KU / 30℃) according to the actual situation, then filter and package with 40 mesh filter cloth, to obtain A component.

[0046] (2) Put 3.28 parts of AD38-1 waterborne epoxy curing agent (mass solid content 80%) and 4.87 parts of deionized water into a container, stir at 600 rpm for 20 minutes to fully mix and uniform; keep stirring, slowly add 3.6 parts of XG-9102 acrylic polymer emulsion (mass solid content 47%), fully stir for 30 minutes to uniform, then slowly add 0.25 parts of alcohol ester twelve film forming aid II and 1 part of ASCOTEC H10 anti-flash rust agent in turn, continue to stir for 30 minutes, to obtain B component.

[0047] (3) Mix the primer A component and B component according to the mass ratio of 100:13 to obtain a quick-drying two-component waterborne epoxy zinc-rich primer.

[0048] Example 2 A preparation method of a quick-drying two-component waterborne epoxy zinc-rich primer, comprising the following steps: (1) Put 15.9 parts of STW600 waterborne epoxy resin (mass solid content 75%), 2 parts of dipropylene glycol butyl ether film forming aid I, 1.6 parts of propylene glycol methyl ether cosolvent I and 4.1 parts of ethylene glycol butyl ether cosolvent II into a dispersion cylinder, start stirring, slowly add 0.6 parts of NEW-0451 anti-settling agent I and 0.6 parts of A200 anti-settling agent II at 600 rpm, after adding, adjust the speed to 1000 rpm and disperse for 10 minutes until uniform and no lumps; reduce the speed to 600 rpm, add 0.1 parts of Tego810 defoamer and 0.1 parts of Tego270 wetting agent in turn, disperse for 10 minutes, then add 68.5 parts of zinc-rich anticorrosive coating special zinc powder and 5.5 parts of QES506 phosphorus iron powder in turn, after adding, adjust the speed to 1000 rpm and disperse, measure the temperature of the material during dispersing, start timing when the temperature rises to 50℃, maintain 50-60℃ for 30 minutes; check the fineness to reach below 60μm, reduce the speed to 500 rpm, add appropriate amount of ethylene glycol butyl ether to supplement the solvent volatilization during dispersing according to the actual situation, and add 1 part of LD-3168 silane coupling agent and continue stirring for 20 minutes, adjust the viscosity to pass (the Stomer viscosity of A+B component mixture is 110-130KU / 30℃) according to the actual situation, filter with 40 mesh cloth and package to obtain A component.

[0049] (2) Put 2.87 parts of AD38-1 waterborne epoxy curing agent (mass solid content 80%) and 4.39 parts of deionized water into a container, stir at 600 rpm for 20 minutes to fully mix and uniform; keep stirring, slowly add 9.1 parts of XG-9102 acrylic acid polymer emulsion (mass solid content 47%), fully stir for 30 minutes to uniform, then slowly add 0.64 parts of alcohol ester twelve film forming aid II and 1 part of ASCOTEC H10 anti-flash rust agent in turn, continue to stir for 30 minutes to obtain B component.

[0050] (3) Mix the primer A component and B component according to the mass ratio of 100:18 to obtain a quick-drying two-component waterborne epoxy zinc-rich primer.

[0051] Example 3 A preparation method of a quick-drying two-component waterborne epoxy zinc-rich primer, comprising the following steps: (1) Put 14.1 parts of STW600 waterborne epoxy resin (mass solid content 75%), 2 parts of dipropylene glycol butyl ether film forming aid I, 1.8 parts of propylene glycol methyl ether cosolvent I and 4.1 parts of ethylene glycol butyl ether cosolvent II into a dispersion cylinder, start stirring, slowly add 0.6 parts of NEW-0451 anti-settling agent I and 0.6 parts of A200 anti-settling agent II at 600 rpm, after adding, adjust the speed to 1000 rpm and disperse for 10 minutes until uniform and no lumps; reduce the speed to 600 rpm, add 0.1 parts of Tego810 defoamer and 0.1 parts of Tego270 wetting agent in turn, disperse for 10 minutes, then add 70 parts of zinc-rich anticorrosive coating special zinc powder and 5.6 parts of QES506 phosphorus iron powder in turn, after adding, adjust the speed to 1000 rpm and disperse at high speed, measure the temperature of the material while dispersing, start timing when the temperature rises to 50℃, maintain 50-60℃ for 30 minutes; check the fineness to reach below 60μm, reduce the speed to 500 rpm, and add appropriate amount of ethylene glycol butyl ether to supplement the solvent volatilization during dispersion according to the actual situation, and add 1 part of LD-3168 silane coupling agent and continue stirring for 20 minutes, adjust the viscosity to qualified (Stomer viscosity of A+B component mixture is 110-130KU / 30℃) according to the actual situation, then filter and package with 40 mesh filter cloth, to obtain A component.

[0052] (2) Put 2.53 parts of AD38-1 waterborne epoxy curing agent (mass solid content 80%) and 3.13 parts of deionized water into a container, stir at 600 rpm for 20 minutes to fully mix and uniform; keep stirring, slowly add 13.4 parts of XG-9102 acrylic acid polymer emulsion (mass solid content 47%), fully stir for 30 minutes to uniform, then slowly add 0.94 parts of alcohol ester twelve film forming aid II and 1 part of ASCOTEC H10 anti-flash rust agent in turn, continue to stir for 30 minutes, to obtain B component.

[0053] (3) Mix the primer A component and B component according to the mass ratio of 100:21 to obtain a quick-drying two-component waterborne epoxy zinc-rich primer.

[0054] Example 4 A preparation method of a quick-drying two-component waterborne epoxy zinc-rich primer, comprising the following steps: (1) Add 11 parts of STW600 waterborne epoxy resin (75% solid content by weight), 2 parts of dipropylene glycol butyl ether film-forming aid I, 1.6 parts of propylene glycol methyl ether cosolvent I and 4.1 parts of ethylene glycol butyl ether cosolvent II to a dispersion tank, start stirring, and slowly add 0.6 parts of NEW-0451 anti-settling agent I and 0.6 parts of A200 anti-settling agent II at 600 rpm. After adding, adjust the speed to 1000 rpm and disperse at high speed for 10 min until uniform and free of lumps. Reduce the speed to 600 rpm, and add 0.1 parts of Tego810 defoamer and 0.1 parts of Tego270 wetting agent in sequence, disperse for 10 min, and then add 73 parts of zinc-rich anti-corrosion coating special. Zinc powder and 5.9 parts of QES506 ferrophosphorus powder were added and then dispersed at high speed at 1000 rpm. The material temperature was measured while dispersing. Once the temperature rose to 50℃, the timer was started and the dispersion was maintained at 50-60℃ for 30 minutes. When the fineness reached below 60μm, the speed was reduced to 500 rpm. An appropriate amount of ethylene glycol butyl ether was added to replenish the solvent evaporated during the dispersion process, and 1 part of LD-3168 silane coupling agent was added and stirring was continued for 20 minutes. The viscosity was adjusted to meet the requirements with an appropriate amount of ethylene glycol butyl ether (Stormer viscosity of A+B components after mixing is 110-130 KU / 30℃). The mixture was then filtered and packaged using a 40-mesh filter cloth to obtain component A.

[0055] (2) Add 2 parts of AD38-1 waterborne epoxy curing agent (80% solid content by mass) and 3.53 parts of deionized water to a container and stir at 600 rpm for 20 min to mix them thoroughly. While stirring, slowly add 21 parts of XG-9102 acrylic polymer emulsion (47% solid content by mass) and stir thoroughly for 30 min until uniform. Then slowly add 1.47 parts of alcohol ester twelve film-forming aid II and 1 part of ASCOTEC H10 anti-flash rust agent in sequence and continue stirring for 30 min to obtain component B.

[0056] (3) Mix the primer components A and B thoroughly at a mass ratio of 100:29 to obtain a fast-drying two-component waterborne epoxy zinc-rich primer.

[0057] Comparative Example 1 A method for preparing a fast-drying two-component waterborne epoxy zinc-rich primer includes the following steps: (1) Add 19.8 parts of STW600 waterborne epoxy resin (75% solid content by weight), 2 parts of dipropylene glycol butyl ether film-forming aid I, 0.7 parts of propylene glycol methyl ether cosolvent I and 4.1 parts of ethylene glycol butyl ether cosolvent II to a dispersion tank, start stirring, and slowly add 0.6 parts of NEW-0451 anti-settling agent I and 0.6 parts of A200 anti-settling agent II at 600 rpm. After adding, adjust the speed to 1000 rpm and disperse at high speed for 10 min until uniform and free of lumps. Reduce the speed to 600 rpm, and add 0.1 parts of Tego810 defoamer and 0.1 parts of Tego270 wetting agent in sequence, disperse for 10 min, and then add 66 parts of zinc-rich anti-corrosion coating in sequence. Add 5 parts of special zinc powder and 5 parts of QES506 ferrophosphorus powder. After adding, adjust the speed to 1000 rpm for high-speed dispersion. Measure the material temperature while dispersing. Start timing when the temperature rises to 50℃ and maintain dispersion at 50-60℃ for 30 minutes. Check that the fineness reaches below 60μm, reduce the speed to 500 rpm, and add an appropriate amount of ethylene glycol butyl ether to replenish the solvent evaporated during the dispersion process, as needed. Add 1 part of LD-3168 silane coupling agent and continue stirring for 20 minutes. Adjust the viscosity to the required level using an appropriate amount of ethylene glycol butyl ether (Stormer viscosity of A+B components after mixing is 110-130 KU / 30℃), then filter and package using a 40-mesh filter cloth to obtain component A.

[0058] (2) Add 3.56 parts of AD38-1 waterborne epoxy curing agent (80% solid content by mass) and 5.44 parts of deionized water to a container, and stir at 600 rpm for 20 min to make it fully mixed; while stirring, slowly add 1 part of ASCOTEC H10 anti-flash rust agent, and continue stirring for 30 min to obtain component B.

[0059] (3) Mix the primer components A and B thoroughly at a mass ratio of 100:10 to obtain a fast-drying two-component waterborne epoxy zinc-rich primer.

[0060] Comparative Example 2 Similar to component A in Example 2, only the type and amount of raw materials in component B are different. The solids content of XG-9102 acrylic polymer emulsion is replaced with conventional XG-902 acrylic polymer emulsion (46% by mass solids). Due to the high glass transition temperature of this emulsion, the content of alcohol ester twelve film-forming aid II is increased from 7% to 9% of the total acrylic polymer emulsion to balance the film-forming temperature, and deionized water is used to balance the formulation. See Table 1 for details.

[0061] The zinc content is the most critical indicator in zinc-rich primers, as it is the biggest factor affecting their anti-corrosion performance. Therefore, this invention achieves a zinc content of 70% in non-volatile materials by fine-tuning the propylene glycol methyl ether cosolvent I and QES506 ferrophosphorus powder in component A. Similarly, the ratio of pigments, fillers, and resin in the formulation (pigment-to-binder ratio) also has a significant impact on the performance of zinc-rich primers. In component B, the performance changes are mainly examined by adjusting the mass solids ratio of acrylic polymer emulsion to waterborne epoxy resin + waterborne epoxy curing agent, while maintaining a pigment-to-binder ratio of 4:1. In addition, to ensure the film-forming performance of the acrylic polymer emulsion, the film-forming aid, alcohol ester twelve, is added to component B at 7% of the total mass of the acrylic polymer emulsion (except for comparative example 2). Specific parameters are summarized in Table 1.

[0062] Table 1

[0063] Performance testing Performance tests were conducted on Examples 1-4 and Comparative Examples 1-2 according to the Type II organic zinc-rich primer (zinc content in non-volatile matter ≥70%) in the HG / T 3668--2020 standard "Zinc-Rich Primer". For salt spray resistance, one coat was applied to a 150*70*3mm sandblasted steel plate with a dry film thickness of (90±10)μm as specified in the standard. After curing for 7 days as required, the unidirectional corrosion spread at the scratches was ≤2.0mm, and the areas without scratches did not blister, rust, crack, or peel off, which was considered qualified. The continuous condensation test of the supporting coating was conducted in accordance with GB / T13893-2008. The sample preparation for the supporting coating was based on the demonstration of the supporting system of common water-based anti-corrosion coatings for low alloy carbon steel in Table B.1 of HG / T 5176-2017 "Water-based Anti-corrosion Coatings for Steel Structures". The system consisted of one 60μm coat of water-based epoxy zinc-rich primer, one 80μm coat of Shuanghu WM320 water-based micaceous iron oxide epoxy intermediate paint, and two 80μm coats of Shuanghu WPU2000 water-based acrylic polyurethane topcoat. After the test, the sample was taken out for observation. The sample was considered qualified if the surface did not blister, rust, crack, or peel. The results are shown in Table 2.

[0064] Table 2

[0065] Please refer to Table 1-2. As can be seen from Table 1-2, the surface drying and hard drying times of Examples 1-4 are significantly reduced as the amount of acrylic polymer emulsion added increases. In Examples 2 and 3, after adding acrylic polymer emulsions with a composite emulsifier structure containing 30% and 50% of the solids of epoxy resin, respectively, the drying properties are significantly improved, meeting the 3-5h recoating time requirement. This greatly saves coating waiting time and improves coating efficiency. Moreover, the salt spray resistance and other performance indicators of the paint film are slightly improved compared to Comparative Example 1 without the addition of acrylic polymer emulsion. While improving coating efficiency, the anti-corrosion performance of the paint film is also improved. Its various performance indicators meet the Type II organic zinc-rich primer standard in HG / T 3668-2020 "Zinc-Rich Primer" standard, and the continuous condensation test meets the 240h requirement of atmospheric corrosion level C3 (H) in the performance requirements of waterborne anti-corrosion coating system in HG / T 5176-2017 "Waterborne Anti-corrosion Coatings for Steel Structures".

[0066] As can be seen from Examples 1-4 and Comparative Example 1, Comparative Example 1 is a standard waterborne epoxy zinc-rich primer without the addition of acrylic polymer emulsion modification. Its drying time is as long as 12 hours, requiring overnight application before the next coat, resulting in a prolonged construction cycle and low efficiency. Example 1, with the addition of 10% acrylic polymer emulsion (epoxy resin solids), showed a reduction in both film drying time and salt spray resistance. Example 4, with the addition of 100% acrylic polymer emulsion (epoxy resin solids), while significantly reducing drying time, also exhibited a marked decrease in salt spray resistance, highlighting the superior film properties of the acrylic polymer emulsion.

[0067] As can be seen from Comparative Example 2 and Example 2, the conventional acrylic polymer emulsion added in Comparative Example 2 has poor stability after being added to the epoxy resin system, resulting in the coating film performance, such as salt spray resistance, being inferior to that in Example 2. This indicates that the special type of acrylic polymer emulsion selected in this invention can not only reduce the drying time of waterborne epoxy zinc-rich primer and improve coating efficiency, but also improve its stability during the mixing process with waterborne epoxy resin, avoiding a significant decrease in coating film performance, such as salt spray resistance.

[0068] Compared with the prior art, the present invention has the following advantages: (1) By introducing an acrylic polymer emulsion with a composite emulsifier structure into the formulation of a two-component waterborne epoxy zinc-rich primer, the present invention can not only reduce the drying time of the waterborne epoxy zinc-rich primer and improve the coating efficiency, but also improve its stability during the mixing process with waterborne epoxy resin, and avoid a significant decline in the performance of the paint film such as salt spray resistance. (2) By controlling the ratio of acrylic polymer emulsion with composite emulsifier structure to epoxy resin solids, the present invention can simultaneously improve the salt spray resistance, corrosion resistance and self-drying properties of the paint film compared with the addition of acrylic polymer emulsion.

[0069] The specific embodiments of the present invention described above do not constitute a limitation on the scope of protection of the present invention. Any other corresponding changes and modifications made in accordance with the technical concept of the present invention should be included within the scope of protection of the claims of the present invention.

Claims

1. A fast-drying two-component waterborne epoxy zinc-rich primer, characterized in that, The raw materials include component A and component B; wherein, by weight, component A includes: 10-20 parts of waterborne epoxy resin, 38-88 parts of zinc powder, and 0.01-50 parts of phosphorus iron powder; component B includes: 5-40 parts of waterborne epoxy curing agent, 10-60 parts of deionized water, and 2-75 parts of acrylic polymer emulsion; the acrylic polymer emulsion is obtained by emulsion polymerization reaction, and a composite emulsifier composed of anionic and nonionic emulsifiers is used as the emulsifier during the emulsion polymerization reaction.

2. The fast-drying two-component waterborne epoxy zinc-rich primer according to claim 1, characterized in that, The waterborne epoxy resin is an anhydrous resin system prepared by hydrophilically modifying one or more of E51, E44, E20, and E12 epoxy resins, and then diluting them with a hydrophilic organic solvent; and / or, The waterborne epoxy resin has a solid content of 70%-80% by weight; and / or, The water-based epoxy curing agent is an amine-based curing agent; and / or, The waterborne epoxy curing agent is one or more selected from aliphatic amines, alicyclic amines, aromatic amines, and polyamides; and / or, The water-based epoxy curing agent has a solid content of 75%-85% by weight; and / or, The acrylic polymer emulsion has a solid content of 40%-50% by weight; and / or, The acrylic polymer emulsion is one or more of Hebei Hengshui Xinguang Chemical XG-2391 and XG-9102.

3. The fast-drying two-component waterborne epoxy zinc-rich primer according to claim 1, characterized in that, The anionic emulsifier is one or more selected from sodium dodecyl sulfate, sodium fatty alcohol polyoxyethylene ether sulfate, sodium dodecylbenzene sulfonate, succinate sulfonate, fatty alcohol polyoxyethylene ether phosphate, and allyloxyhydroxypropyl sulfonate; and / or, The nonionic emulsifier is one or more of alkylphenol polyoxyethylene ether, fatty alcohol polyoxyethylene ether, fatty acid polyoxyethylene ester, and allyl polyoxyethylene ether.

4. The fast-drying two-component waterborne epoxy zinc-rich primer according to claim 1, characterized in that, Component A further includes one or more of the following: film-forming aid I, cosolvent, anti-settling agent, defoamer, wetting agent, and silane coupling agent; Component B further includes one or more of the following: film-forming aid II and anti-flash rust agent; wherein... The film-forming aid I and film-forming aid II are one or more of dipropylene glycol butyl ether, benzyl alcohol, propylene glycol phenyl ether, and dodecyl alcohol ester, respectively; and / or, The co-solvent is one or more selected from isopropanol, ethylene glycol butyl ether, diethylene glycol butyl ether, propylene glycol methyl ether, dipropylene glycol methyl ether, and propylene glycol ethyl ether; and / or, The anti-settling agent is one or more of polyamide wax, organically modified bentonite, hydrated magnesium aluminum silicate, and fumed silica; and / or, The defoamer is one or more selected from mineral oil defoamers, silicone defoamers, and polymer defoamers; and / or... The wetting agent is one or more of organosilicon wetting agents, acetylenic diol wetting agents, and fluorocarbon wetting agents; and / or, The silane coupling agent is a silane oligomer modified with epoxy end groups; and / or, The flash rust inhibitor is an aqueous solution of sodium nitrite or an organic acid salt.

5. The fast-drying two-component waterborne epoxy zinc-rich primer according to claim 1, characterized in that, By weight, component A comprises: 13-17 parts of waterborne epoxy resin, 60-80 parts of zinc powder, and 1-10 parts of ferric phosphorus powder; component B comprises: 10-20 parts of waterborne epoxy curing agent, 10-30 parts of deionized water, and 45-65 parts of acrylic polymer emulsion; and / or, By weight, component A comprises: 10-20 parts of waterborne epoxy resin, 1-5 parts of film-forming aid I, 0.1-13 parts of co-solvent, 0.2-2 parts of anti-settling agent, 0.05-0.5 parts of defoamer, 0.05-0.5 parts of wetting agent, 38-88 parts of zinc powder, 0.01-50 parts of phosphorus iron powder, and 0.1-3 parts of silane coupling agent; component B comprises: 5-40 parts of waterborne epoxy curing agent, 10-60 parts of deionized water, 2-75 parts of acrylic polymer emulsion, 0.1-10 parts of film-forming aid II, and 0.5-10 parts of flash rust inhibitor; and / or, By weight, component A comprises: 13-17 parts of waterborne epoxy resin, 1-5 parts of film-forming aid I, 2-10 parts of co-solvent, 0.5-2 parts of anti-settling agent, 0.05-0.5 parts of defoamer, 0.05-0.5 parts of wetting agent, 60-80 parts of zinc powder, 1-10 parts of phosphorus iron powder, and 0.3-3 parts of silane coupling agent; component B comprises: 10-20 parts of waterborne epoxy curing agent, 10-30 parts of deionized water, 45-65 parts of acrylic polymer emulsion, 1-10 parts of film-forming aid II, and 1-5 parts of flash rust inhibitor.

6. The fast-drying two-component waterborne epoxy zinc-rich primer according to claim 1, characterized in that, By weight, the solids content of the acrylic polymer emulsion accounts for 30%-50% of the total solids content of the waterborne epoxy resin and the waterborne epoxy curing agent; and / or, The pigment-to-binder ratio in the fast-drying two-component waterborne epoxy zinc-rich primer is (3.5-4.5):1; and / or, The mass ratio of component A to component B is 100:(10-30).

7. A method for preparing a fast-drying two-component waterborne epoxy zinc-rich primer as described in any one of claims 1-6, characterized in that, Includes the following steps: S1. Mix the raw materials of component A evenly to obtain component A; S2. Mix the raw materials of component B evenly to obtain component B; S3. Mix component A and component B evenly to obtain a fast-drying two-component waterborne epoxy zinc-rich primer.

8. The preparation method of the fast-drying two-component waterborne epoxy zinc-rich primer according to claim 7, characterized in that, Step S1 includes: S11. Add waterborne epoxy resin, film-forming aid I and cosolvent to the first container, start stirring, add anti-settling agent at 500-600 rpm, and after adding, adjust the speed to 800-1000 rpm for high-speed dispersion for 5-10 minutes until uniform and free of lumps. S12. Reduce the speed to 500-600 rpm, add defoamer and wetting agent in sequence, disperse for 5-10 minutes, then add zinc powder and iron phosphate powder in sequence. After adding, adjust the speed to 800-1000 rpm for high-speed dispersion. Start timing after the temperature rises to 50℃, and maintain dispersion at 50-60℃ for 20-30 minutes. S13. Once the particle size reaches below 60μm, reduce the rotation speed to 300-500rpm and replenish the solvent evaporated during dispersion with a co-solvent. Then add the silane coupling agent and continue stirring for 10-20 minutes. After adjusting the viscosity to the appropriate level, filter to obtain component A. The viscosity was adjusted using a co-solvent until the Stormer viscosity at 30°C after mixing components A and B was 110-130 KU; and / or, Use 30-50 mesh filter cloth for filtration.

9. The preparation method of the fast-drying two-component waterborne epoxy zinc-rich primer according to claim 7, characterized in that, Step S2 includes: S21. Add water-based epoxy curing agent and deionized water to the second container, and stir at 500-600 rpm for 10-20 minutes to make it fully mixed. S22. While stirring, add the acrylic polymer emulsion and stir thoroughly for 20-30 minutes. Then, slowly add film-forming aid II and anti-flash rust agent in sequence and continue stirring for 20-30 minutes to obtain component B.

10. An application of the fast-drying two-component waterborne epoxy zinc-rich primer as described in any one of claims 1-6, characterized in that, The fast-drying two-component waterborne epoxy zinc-rich primer is used in mechanical equipment and bridge steel structures.

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