Solvent-free epoxy coating for drinking water tank and preparation method of solvent-free epoxy coating

Abstract

The invention relates to the field of coatings, in particular to a solvent-free epoxy coating for a drinking water tank and a preparation method thereof.The solvent-free epoxy coating is prepared from a component A and a component B. The component A comprises 40-60 parts of epoxy resin, 5-20 parts of reactive diluent, 0.3-0.5 part of dispersing agent, 0.1-0.8 part of defoaming agent, 0.6-1.2 parts of thixotropic agent, 20-35 parts of pigment and 10-20 parts of filler; the epoxy resin comprises bisphenol A epoxy vinyl ester resin and hydrogenated bisphenol A resin; the active diluent comprises a cardanol-based active diluent and 4-epoxy isoeugenol; the dispersing agent comprises a polymeric dispersing agent and polyurethane acrylate porous microspheres; the component B comprises a modified alicyclic amine curing agent and cardanol carbamate, and the mass ratio of the modified alicyclic amine curing agent to the cardanol carbamate is (1.8-5): 1; the amine value of the modified alicyclic amine curing agent is 360 to 420 mgKOH / g. The solvent-free epoxy coating for the drinking water tank is non-toxic, has relatively strong adhesive force, water resistance, flexibility and antibacterial property and relatively long service life, and is suitable for various drinking water tanks.

Description

Technical Field

[0001] The invention relates to the field of coatings, and in particular to a solvent-free epoxy coating for a drinking water tank and a preparation method thereof. Background Art

[0002] Drinking water tanks include ship drinking water tanks, ballast tanks and various fresh water storage tanks. Since drinking water tanks are small, dark, damp and easily corroded, it is necessary to apply anti-corrosion coatings on the surface of drinking water tanks. At present, commonly used anti-corrosion coatings include polyamide-cured epoxy coatings, solvent-free epoxy coatings, ketimine-cured epoxy coatings and lacquer phenol coatings. Among them, solvent-free epoxy coatings have attracted much attention due to their low volatile organic compound (VOC) emissions and one-time film formation. However, the high viscosity of this type of coating increases the difficulty of construction, the paint film has poor toughness, is easy to crack, has poor corrosion resistance and antibacterial properties, and is prone to blistering, fading and even falling off in long-term contact with water. This will not only shorten the service life of the paint film and cause corrosion of the container, but may also provide a breeding ground for microbial growth, affect the sanitary quality of drinking water, and endanger human health. Summary of the invention

[0003] Therefore, the technical problem to be solved by the present invention is to overcome the deficiencies and defects in the prior art, thereby providing a non-toxic, low-viscosity, solvent-free epoxy coating and a preparation method thereof that can improve the adhesion, water resistance, flexibility, antibacterial properties of the paint film and prolong the service life.

[0004] To solve the above problems: The present invention provides a solvent-free epoxy coating for a drinking water tank, characterized in that it comprises a component A and a component B: The component A comprises the following raw materials in parts by weight: 40-60 parts of epoxy resin, 5-20 parts of active diluent, 0.3-0.5 parts of dispersant, 0.1-0.8 parts of defoamer, 0.6-1.2 parts of thixotropic agent, 20-35 parts of pigment, and 10-20 parts of filler; The epoxy resin includes bisphenol A epoxy vinyl ester resin and hydrogenated bisphenol A type resin; The active diluent includes a cardanol-based active diluent and 4-epoxyisoeugenol; The dispersant includes a polymer dispersant and polyurethane acrylate porous microspheres; The B component includes a modified alicyclic amine curing agent and cardanol carbamate, and the mass ratio of the modified alicyclic amine curing agent to cardanol carbamate is (1.8-5):1; The amine value of the modified alicyclic amine curing agent is 360-420 mgKOH / g; When in use, component A and component B are mixed in a mass ratio of (3-10):1.

[0005] In the present invention, the epoxy resin is a compound of bisphenol A epoxy vinyl ester resin and hydrogenated bisphenol A type resin. Bisphenol A epoxy vinyl ester resin and hydrogenated bisphenol A type resin work together to form a more dense and uniform cross-linked network structure during the paint film curing process, which not only improves the adhesion and impact resistance of the paint film, but also strengthens its internal chemical bonding force, so that the paint film can better resist the damage to its structure by external factors, thereby improving the corrosion resistance and water resistance of the paint film, and avoiding the influence of low-temperature curing moisture absorption and curing moisture absorption on the mechanical properties of the paint film.

[0006] Preferably, the bisphenol A epoxy vinyl ester resin is TM-V211 and / or Derakane™ 411; the hydrogenated bisphenol A type resin includes one or more of AL-3040, SH-3000, EP-4080E. In order to ensure the excellent performance of the paint film, the mass ratio of the bisphenol A epoxy vinyl ester resin to the hydrogenated bisphenol A type resin is 1: (1-2).

[0007] Further preferably, in order to improve the water resistance of the paint film and ensure the curing speed of the epoxy resin, the epoxy equivalent of the hydrogenated bisphenol A type resin is 200-250 g / mol.

[0008] In the present invention, the active diluent is a cardanol-based active diluent and a composite of 4-epoxyisoeugenol. Although the cardanol-based active diluent can participate in the curing process, the curing speed is relatively slow and is not conducive to construction. In the coating system of the present invention, after introducing 4-epoxyisoeugenol, due to the different activities of the active groups of the cardanol-based active diluent and 4-epoxyisoeugenol in participating in the epoxy resin curing reaction, by adjusting the mass ratio of the two, the activity of the epoxy group in the active diluent participating in the epoxy resin curing reaction can be regulated, and then the curing speed of the coating is adjusted, the curing time of the coating is shortened, and the construction efficiency is improved. The compounded small molecular weight active diluent can be interspersed between the resin macromolecules, reducing the mutual entanglement between the macromolecules, greatly reducing the viscosity of the resin, and then reducing the viscosity of the coating, improving the leveling and wettability of the coating, and the compounded active diluent can chemically react with epoxy resin, curing agent and other ingredients to become a part of the cross-linked network structure of the epoxy resin curing material, thereby enhancing the chemical bonding inside the coating, improving the adhesion and corrosion resistance of the paint film, and the dense paint film is assisted by the hydrophobic groups introduced by the compounded active diluent, which further improves the water resistance of the paint film. At the same time, the cross-linked network of the flexible chain segments and the rigid chain segments is interspersed with each other, so that the coating has both flexibility and hardness, effectively improving the impact resistance and wear resistance of the coating, and reducing the erosion and damage of the coating by the external environment.

[0009] Preferably, the cardanol-based active diluent is selected from one or more of LITE 513DF, Ultra LITE 513, and NC-513.

[0010] Further preferably, in order to shorten the paint film curing time and improve the coating performance, the mass ratio of the cardanol-based reactive diluent to 4-epoxyisoeugenol is 4:1; and the epoxy equivalent of the cardanol-based reactive diluent is 250-550 g / mol.

[0011] In the present invention, the dispersant is a compound of a polymer dispersant and a polyurethane acrylate porous microsphere. The polyurethane acrylate porous microsphere can enhance the compatibility between the resin and the auxiliary agent, adjust the viscosity and fluidity of the coating, improve the dispersion of the pigment and filler particles in the coating system, and then improve the gloss and color intensity of the paint film, and avoid the problems of color difference, spots, stripes, etc. in the paint film. Further, the acrylate group of the polyurethane acrylate porous microsphere acts on the epoxy resin and the active diluent in the microsphere pores and the cardanol carbamate, which increases the tightness between the molecular chains of the paint film, makes the coating solidify more fully, and then enhances the water resistance, corrosion resistance and impact resistance of the coating. In addition, the polyurethane acrylate porous microsphere also interacts with the cardanol carbamate to strengthen the antibacterial properties of the coating, effectively inhibiting the growth of microorganisms on the coating surface.

[0012] Preferably, the polymer dispersant is selected from one or more of Tehaosan™ 2028C, HY-7320, Disuper S9100, and AFCONA-4071; the particle size range of the polyurethane acrylate porous microspheres is 80-100µm, the functionality of the polyurethane acrylate in the polyurethane acrylate porous microspheres is greater than 3, and the mass ratio of the polymer dispersant to the polyurethane acrylate porous microspheres is (1-4):1.

[0013] In the present invention, the active groups in the modified alicyclic amine curing agent are used in the curing agent of the present invention because they can undergo a cross-linking reaction with the epoxy resin to form a network structure. Preferably, the modified alicyclic amine curing agent is WSG-228 and / or BS-1445.

[0014] In the present invention, when the amine value of the modified alicyclic amine curing agent is high, the modified alicyclic amine curing agent has more active amino groups, which can accelerate the curing speed with the epoxy resin, increase the crosslinking density of the cured product, and improve the hardness and wear resistance of the coating; when the amine value of the modified alicyclic amine curing agent is low, the curing speed is relatively slow, the curing time is long, but the paint film has high flexibility. In order to ensure the hardness and flexibility of the paint film, the amine value of the modified alicyclic amine curing agent is 360-420 mgKOH / g.

[0015] In the present invention, a single modified alicyclic amine curing agent is used, because its cross-linking and curing time is long during use, which affects the construction progress, and the paint film formed is not ideal in terms of flexibility, corrosion resistance, etc. Therefore, the present invention increases the reactive center in the system by introducing cardanol carbamate, and these reactive centers can attract and draw the active groups in epoxy resin and modified alicyclic amine curing agent, so that the collision probability between the two increases, thereby accelerating the curing speed and reducing the curing time. Compared to simply relying on increasing the amine value or dosage of modified alicyclic amine to accelerate the curing speed, the added cardanol carbamate not only forms a stable chemical bond by chemically reacting with the active group in epoxy resin, but also increases the cross-linking density of the paint film, improves the corrosion resistance, adhesion and oxidation resistance of the paint film, and the flexible group contained therein can also significantly improve the flexibility of the paint film, thereby effectively avoiding the problem of the decrease in mechanical properties of the paint film caused by simply increasing the amine value or dosage of modified alicyclic amine to accelerate the curing speed. In addition, the lipophilic active groups in cardanol carbamate work synergistically with other components in the paint to reduce the surface tension of the paint film, enhance the water resistance of the paint film, and improve the fluidity of the paint and the compatibility of the various components.

[0016] Preferably, the defoaming agent is a silicone defoaming agent, and the silicone defoaming agent includes one or more of BYK-060, Deqian 6800, and BYK-1799; the thixotropic agent includes one or more of Coapur 830W, Crayvallac Optima, Crayvallac Ultra, and MT-6650; the pigment includes one or more of titanium dioxide, red iron oxide, and carbon black; the filler includes one or more of mica powder, talc, precipitated barium sulfate, and nano-silica.

[0017] The present invention also provides a method for preparing the solvent-free epoxy coating for the drinking water tank, comprising the following preparation steps: (1) Evenly dispersing epoxy resin, active diluent, dispersant, defoamer, thixotropic agent, pigment and filler to obtain component A; (2) Add a modified alicyclic amine curing agent to component A, mix well, then add cardanol carbamate, mix and stir to prepare a solvent-free epoxy coating.

[0018] The specific steps in step (1) include: S1: Add epoxy resin and active diluent into the dispersion kettle in sequence and disperse them evenly; S2: Add the dispersant and defoamer into the dispersion kettle in sequence and disperse them evenly; S3: Add the thixotropic agent into the dispersion kettle and disperse it evenly; S4: Put the pigment and filler into the dispersion kettle in sequence, transfer them to the grinder for grinding after uniform dispersion, add the dispersant, and disperse at high speed for 30 minutes to obtain component A; Preferably, in step S1, step S2 and step S3, the dispersion stirring time is 15-30 min, and in step S4, the fineness of component A is ≤30 µm.

[0019] The technical solution of the present invention has the following advantages: 1. The solvent-free epoxy coating for drinking water tanks provided by the present invention introduces cardanol carbamate as a curing reaction accelerator, which accelerates the curing speed by increasing the reactive centers; and by participating in the curing reaction, the crosslinking density of the paint film is enhanced, thereby improving the corrosion resistance, adhesion and oxidation resistance of the paint film. The introduction of flexible groups further improves the flexibility of the paint film. In addition, cardanol carbamate and other components reduce the surface tension of the coating through synergistic effects, enhance the water resistance of the paint film, and improve the fluidity of the coating and the compatibility of each component.

[0020] 2. The present invention introduces 4-epoxyisoeugenol and a cardanol-based active diluent as an active diluent, and can adjust the curing speed of the coating and shorten the curing time of the coating by adjusting the mass ratio of the cardanol-based active diluent to the 4-epoxyisoeugenol; the compounded active diluent not only acts on the epoxy resin system to reduce the viscosity of the system and improve the leveling and wettability of the coating, but also balances the flexibility and hardness of the paint film by participating in the curing, thereby improving the adhesion, water resistance, corrosion resistance and impact resistance of the paint film, and thus prolonging the service life of the paint film.

[0021] 3. The compounded active diluent of the present invention and cardanol carbamate synergistically act in the curing process of epoxy resin, further improving the curing speed, and giving the coating antibacterial properties, effectively inhibiting the growth and reproduction of bacteria and other microorganisms, so that the cured paint film is not only clean and non-toxic, but also effectively antibacterial, and is suitable for the inner walls of ship drinking water tanks, ballast tanks and various fresh water storage tanks. In addition, the compounded active diluent can also react with cardanol carbamate to generate stable compounds, thereby stabilizing the active diluent, greatly enhancing the stability and durability of the paint film performance, and effectively extending the service life of the drinking water tank.

[0022] 4. The solvent-free epoxy coating provided by the present invention introduces polyurethane acrylate porous microspheres and polymer dispersants as dispersants, which enhances the compatibility between the resin and the additive, adjusts the viscosity and fluidity of the coating, and improves the dispersion of pigments and filler particles in the coating system, thereby improving the gloss and color intensity of the paint film, and avoiding the problems of color difference, spots, stripes, etc. in the paint film. The polyurethane acrylate porous microspheres act on the epoxy resin, the active diluent, and the cardanol carbamate, not only enhancing the water resistance, corrosion resistance, and impact resistance of the coating, but also improving the antibacterial properties of the coating, and can inhibit the growth of microorganisms on the surface of the coating. DETAILED DESCRIPTION

[0023] The following examples are provided for a better understanding of the present invention, but are not intended to limit the best mode of implementation, nor to limit the content and protection scope of the present invention. Any product identical or similar to the present invention obtained by anyone under the inspiration of the present invention or by combining the features of the present invention with other prior arts shall fall within the protection scope of the present invention.

[0024] If no specific experimental steps or conditions are specified in the examples, the conventional experimental steps or conditions described in the literature in the field can be used. If no manufacturer is specified for the reagents or instruments used, they are all conventional reagent products that can be obtained commercially.

[0025] The polyurethane acrylate porous microspheres used in the present invention are prepared according to the method disclosed in CN115572530B. Example 1

[0026] The present invention provides a solvent-free epoxy coating for a drinking water tank, comprising a component A and a component B: The raw materials of component A are calculated by weight and include: 20 parts of AL-3040 (hydrogenated bisphenol A type resin), 10 parts of TM-V211 (bisphenol A epoxy vinyl ester resin), 10 parts of Derakane™ 411 (bisphenol A epoxy vinyl ester resin), 4 parts of LITE513DF (cardanol-based active diluent), 1 part of 4-epoxyisoeugenol (active diluent), 0.2 parts of Tehaosan™ 2028C (polymer dispersant), 0.1 parts of polyurethane acrylate porous microspheres (dispersant), 0.5 parts of BYK-060 (defoaming agent), 1.2 parts of Coapur 830W (thixotropic agent), 35 parts of red iron oxide (pigment), and 10 parts of 1250 mesh mica powder (filler).

[0027] The raw materials of component B are calculated by weight and include: 23 parts of WSG-228 (modified alicyclic amine curing agent) and 7 parts of cardanol carbamate.

[0028] The preparation method of the solvent-free epoxy coating for the drinking water tank comprises: S1: Add 20 parts of AL-3040 (hydrogenated bisphenol A type resin), 10 parts of TM-V211 (bisphenol A epoxy vinyl ester resin), 10 parts of Derakane™ 411 (bisphenol A epoxy vinyl ester resin), 4 parts of LITE 513DF (cardanol-based active diluent), and 1 part of 4-epoxyisoeugenol (active diluent) into the dispersion kettle in sequence and disperse for 15-30 minutes; S2: Add 0.2 parts of Tehaosan™ 2028C (polymer dispersant) and 0.5 parts of BYK-060 (defoaming agent) into the dispersion kettle in sequence and disperse for 15-30 minutes; S3: Add 1.2 parts of Coapur 830W (thixotropic agent) into the dispersion kettle and disperse at high speed for 15-30 minutes; S4: 35 parts of red iron oxide (pigment) and 10 parts of 1250 mesh mica powder (filler) are sequentially put into a dispersion kettle, and after being evenly dispersed, they are transferred to a grinder and ground to a fineness of ≤30µm, and 0.1 parts of polyurethane acrylate porous microspheres (dispersant) are added, and dispersed at high speed for 30 minutes to obtain component A; S5: Add 23 parts of WSG-228 (modified alicyclic amine curing agent) to component A, mix well and then add 7 parts of cardanol carbamate, wherein the mass ratio of component A to component B is 3:1, and stir and dissolve to obtain the solvent-free epoxy coating. Example 2

[0029] The present invention provides a solvent-free epoxy coating for a drinking water tank, comprising a component A and a component B: The raw materials of component A are calculated by weight and include: 30 parts of SH-3000 (hydrogenated bisphenol A type resin), 20 parts of TM-V211 (bisphenol A epoxy vinyl ester resin), 8 parts of Ultra LITE 513 (cardanol-based active diluent), 2 parts of 4-epoxyisoeugenol (active diluent), 0.2 parts of HY-7320 (polymer dispersant), 0.2 parts of polyurethane acrylate porous microspheres (dispersant), 0.1 parts of BYK-1799 (defoaming agent), 0.8 parts of MT-6650 (thixotropic agent), 23 parts of BLR-895 (pigment), 12 parts of 1250 mesh mica powder (filler), and 4 parts of precipitated barium sulfate (filler).

[0030] The raw materials of component B are calculated by weight and include: 13 parts of BS-1445 (modified alicyclic amine curing agent) and 7 parts of cardanol carbamate.

[0031] The preparation method of the solvent-free epoxy coating for the drinking water tank comprises: S1: Add 30 parts of SH-3000 (hydrogenated bisphenol A type resin), 20 parts of TM-V211 (bisphenol A epoxy vinyl ester resin), 8 parts of Ultra LITE 513 (cardanol-based active diluent), and 2 parts of 4-epoxyisoeugenol (active diluent) into the dispersion kettle in sequence and disperse for 15-30 minutes; S2: Add 0.2 parts of HY-7320 (polymer dispersant) and 0.1 parts of BYK-1799 (defoaming agent) into the dispersion kettle in sequence and disperse for 15-30 minutes; S3: Add 0.8 parts of MT-6650 (thixotropic agent) into the dispersion kettle and disperse at high speed for 15-30 minutes; S4: 23 parts of BLR-895 (pigment), 12 parts of 1250 mesh mica powder (filler), and 4 parts of precipitated barium sulfate (filler) are sequentially added into a dispersion kettle, and after being evenly dispersed, they are transferred to a grinder and ground to a fineness of ≤30µm, and 0.2 parts of polyurethane acrylate porous microspheres (dispersant) are added, and dispersed at high speed for 30 minutes to obtain component A; S5: Add 13 parts of BS-1445 (modified alicyclic amine curing agent) to component A, mix well and then add 7 parts of cardanol carbamate, wherein the mass ratio of component A to component B is 5:1, and stir and dissolve to obtain the solvent-free epoxy coating. Example 3

[0032] The present invention provides a solvent-free epoxy coating for a drinking water tank, comprising a component A and a component B: The raw materials of component A are calculated by weight: 20 parts of AL-3040 (hydrogenated bisphenol A type resin), 20 parts of EP-4080E (hydrogenated bisphenol A type resin), 20 parts of Derakane™ 411 (bisphenol A epoxy vinyl ester resin), 10 parts of Ultra LITE513 (cardanol-based active diluent), 6 parts of NC-513 (cardanol-based active diluent), 4 parts of 4-epoxyisoeugenol (active diluent), 0.2 parts of Disuper S9100 (polymer dispersant), 0.1 parts of polyurethane acrylate porous microspheres (dispersant), 0.2 parts of AFCONA-4071 (polymer dispersant), 0.4 parts of Deqian 6800 (defoaming agent), 0.4 parts of BYK-1799 (defoaming agent), 0.3 parts of Crayvallac Optima (thixotropic agent), 0.3 parts of Crayvallac Ultra (thixotropic agent), 20 parts of carbon black (pigment), 15 parts of nano-silica (filler), and 5 parts of precipitated barium sulfate (filler).

[0033] The raw materials of component B are calculated by weight and include: 5 parts of WSG-228 (modified alicyclic amine curing agent), 5 parts of BS-1445 (modified alicyclic amine curing agent), and 2 parts of cardanol carbamate.

[0034] The preparation method of the solvent-free epoxy coating for the drinking water tank comprises: S1: Add 20 parts of AL-3040 (hydrogenated bisphenol A type resin), 20 parts of EP-4080E (hydrogenated bisphenol A type resin), 20 parts of Derakane™ 411 (bisphenol A epoxy vinyl ester resin), 10 parts of Ultra LITE 513 (cardanol-based active diluent), 6 parts of NC-513 (cardanol-based active diluent), and 4 parts of 4-epoxyisoeugenol (active diluent) into a dispersion kettle in sequence and disperse for 15-30 minutes; S2: 0.2 parts of Disuper S9100 (polymer dispersant), 0.2 parts of AFCONA-4071 (polymer dispersant), 0.4 parts of Deqian 6800 (defoaming agent), and 0.4 parts of BYK-1799 (defoaming agent) are sequentially added into the dispersion kettle and dispersed for 15-30 minutes; S3: Add 0.3 parts of Crayvallac Optima (thixotropic agent) and 0.3 parts of Crayvallac Ultra (thixotropic agent) into the dispersion kettle and disperse at high speed for 15-30 minutes; S4: 20 parts of carbon black (pigment), 15 parts of nano-silicon dioxide (filler), and 5 parts of precipitated barium sulfate (filler) are sequentially added into a dispersion kettle, and after being evenly dispersed, they are transferred to a grinder and ground to a fineness of ≤30µm, and 0.1 parts of polyurethane acrylate porous microspheres (dispersant) are added, and dispersed at high speed for 30 minutes to obtain component A; S5: Add 5 parts of WSG-228 (modified alicyclic amine curing agent) and 5 parts of BS-1445 (modified alicyclic amine curing agent) to component A, mix well and then add 2 parts of cardanol carbamate, wherein the mass ratio of component A to component B is 10:1, and stir and dissolve to obtain the solvent-free epoxy coating.

[0035] Comparative Example 1 This comparative example provides a solvent-free epoxy coating for a drinking water tank, which is different from Example 2 in that this comparative example replaces the cardanol carbamate with an equal amount of modified alicyclic amine curing agent BS-1445.

[0036] Comparative Example 2 This comparative example provides a solvent-free epoxy coating for a drinking water tank, which is different from Example 2 in that an equal amount of cardanol-based reactive diluent Ultra LITE 513 is used in this comparative example to replace 4-epoxyisoeugenol.

[0037] Comparative Example 3 This comparative example provides a solvent-free epoxy coating for a drinking water tank, which differs from Example 2 in that the polyurethane acrylate porous microspheres are replaced with an equal amount of polymer dispersant HY-7320 in this comparative example.

[0038] Comparative Example 4 This comparative example provides a solvent-free epoxy coating for drinking water tanks. The difference from Example 2 is that this comparative example uses an equal amount of bisphenol A epoxy resin DER 331 to replace hydrogenated bisphenol A resin SH-3000 and bisphenol A epoxy vinyl ester resin TM-V211.

[0039] In the present invention, the coatings of Examples 1-3 and Comparative Examples 1-4 were respectively used to prepare coating films with a thickness of 100±20 um on a steel substrate, and performance tests were performed. The test results are shown in Table 1.

[0040] Table 1 Coating performance test methods and solvent-free epoxy coating performance test results

[0041] As can be seen from Table 1, the present invention provides a solvent-free epoxy coating with good adhesion and flexibility, strong water resistance and corrosion resistance, antibacterial properties and short curing time, which is suitable for the inner walls of ship drinking water tanks, ballast tanks and various fresh water storage tanks.

[0042] By comparing Comparative Example 1 and Example 2, it is found that the addition of cardanol carbamate to the solvent-free epoxy coating enhances the salt spray resistance, water resistance, adhesion, flexibility of the paint film and improves the curing speed.

[0043] By comparing Comparative Example 2 and Example 2, it is found that the cardanol-based active diluent and 4-epoxyisoeugenol are compounded as active diluents, which improves the impact resistance, adhesion, water resistance and salt spray resistance of the paint film, thereby ensuring the stability and durability of the coating system performance.

[0044] By comparing Comparative Examples 1 and 2 with Example 2, it is found that the compounded active diluent and cardanol carbamate synergistically enhance the antibacterial property of the coating and increase the curing speed.

[0045] By comparing Comparative Example 3 and Example 2, it is found that the compounding of the porous microspheres of polyurethane acrylate and the polymer dispersant enhances the gloss stability, water resistance and impact resistance of the paint film; compared with Example 2, the porous microspheres of polyurethane acrylate and the cardanol carbamate interact with each other, which enhances the corrosion resistance and impact resistance of the coating and improves the antibacterial properties of the coating.

[0046] By comparing Comparative Example 4 and Example 2, it is found that the synergistic effect of hydrogenated bisphenol A type resin and bisphenol A epoxy vinyl ester resin is beneficial to enhancing the adhesion, impact resistance, water resistance and salt spray resistance of the paint film.

[0047] Obviously, the above embodiments are merely examples for the purpose of clear explanation, and are not intended to limit the implementation methods. For those skilled in the art, other different forms of changes or modifications can be made based on the above description. It is not necessary and impossible to list all the implementation methods here. The obvious changes or modifications derived therefrom are still within the scope of protection of the present invention.

Claims

1. A solvent-free epoxy coating for a drinking water tank, characterized in that: Including component A and component B: The component A comprises the following raw materials in parts by weight: 40-60 parts of epoxy resin, 5-20 parts of active diluent, 0.3-0.5 parts of dispersant, 0.1-0.8 parts of defoamer, 0.6-1.2 parts of thixotropic agent, 20-35 parts of pigment, and 10-20 parts of filler; The epoxy resin includes bisphenol A epoxy vinyl ester resin and hydrogenated bisphenol A type resin; The active diluent includes a cardanol-based active diluent and 4-epoxyisoeugenol; The dispersant includes a polymer dispersant and polyurethane acrylate porous microspheres; The B component includes a modified alicyclic amine curing agent and cardanol carbamate, and the mass ratio of the modified alicyclic amine curing agent to cardanol carbamate is (1.8-5):1; The amine value of the modified alicyclic amine curing agent is 360-420 mgKOH / g; When in use, component A and component B are mixed in a mass ratio of (3-10):

1.

2. The solvent-free epoxy coating for drinking water tanks according to claim 1, characterized in that: The cardanol-based active diluent includes one or more of LITE 513DF, Ultra LITE 513, and NC-513.

3. A solvent-free epoxy coating for drinking water tanks according to claim 1 or 2, characterized in that: The mass ratio of the cardanol-based active diluent to 4-epoxyisoeugenol is 4:1; The epoxy equivalent of the cardanol-based active diluent is 250-550 g / mol.

4. The solvent-free epoxy coating for drinking water tanks according to claim 1, characterized in that: The bisphenol A epoxy vinyl ester resin is TM-V211 and / or Derakane™ 411; The hydrogenated bisphenol A type resin includes one or more of AL-3040, SH-3000, and EP-4080E; the epoxy equivalent of the hydrogenated bisphenol A type resin is 200-250 g / mol.

5. The solvent-free epoxy coating for drinking water tanks according to claim 1, characterized in that: The polymer dispersant includes one or more of Tehaosan™ 2028C, HY-7320, Disuper S9100, and AFCONA-4071.

6. The solvent-free epoxy coating for drinking water tanks according to claim 1, characterized in that: The particle size of the polyurethane acrylate porous microspheres is in the range of 80-100 μm, and the functionality of the polyurethane acrylate in the polyurethane acrylate porous microspheres is greater than 3.

7. The solvent-free epoxy coating for drinking water tanks according to claim 1, characterized in that: The modified alicyclic amine curing agent is WSG-228 and / or BS-1445.

8. The solvent-free epoxy coating for drinking water tanks according to claim 1, characterized in that: The defoamer is an organosilicon defoamer, and the organosilicon defoamer includes one or more of BYK-060, Deqian 6800, and BYK-1799; The thixotropic agent includes one or more of Coapur 830W, Crayvallac Optima, Crayvallac Ultra, and MT-6650; The pigment includes one or more of titanium dioxide, red iron oxide, and carbon black; The filler includes one or more of mica powder, talc powder, precipitated barium sulfate, and nano silicon dioxide.

9. The method for preparing the solvent-free epoxy coating for drinking water tanks according to any one of claims 1 to 8, characterized in that: The method comprises the following preparation steps: (1) Evenly dispersing epoxy resin, active diluent, dispersant, defoamer, thixotropic agent, pigment and filler to obtain component A; (2) Add a modified alicyclic amine curing agent to component A, mix well, then add cardanol carbamate, mix and stir to prepare a solvent-free epoxy coating.

10. The method for preparing a solvent-free epoxy coating for a drinking water tank according to claim 9, characterized in that: The fineness of the component A is ≤30µm.

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