A solvent-free epoxy coating for a drinking water tank and its preparation method

Abstract

The present invention relates to the field of coatings, and specifically relates to a solvent-free epoxy coating for drinking water tanks and a preparation method thereof. The solvent-free epoxy coating, component A includes: 40-60 parts of epoxy resin, 5-20 parts of reactive 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 reactive diluent includes cardanol-based reactive diluent and 4-epoxyisoeugenol; the dispersant includes polymer dispersant and polyurethane acrylate porous microspheres; component B includes: 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. The solvent-free epoxy coating for drinking water tanks of the present invention is non-toxic and has strong adhesion, water resistance, flexibility, antibacterial property and a long service life, and is applicable to 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:

[0005] 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:

[0006] 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;

[0007] The epoxy resin includes bisphenol A epoxy vinyl ester resin and hydrogenated bisphenol A type resin;

[0008] The active diluent includes a cardanol-based active diluent and 4-epoxyisoeugenol;

[0009] The dispersant includes a polymer dispersant and polyurethane acrylate porous microspheres;

[0010] 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;

[0011] The amine value of the modified alicyclic amine curing agent is 360-420mgKOH / g;

[0012] During use, components A and B are mixed in a mass ratio of (3-10):1.

[0013] In the present invention, the epoxy resin is a compound of bisphenol A epoxy vinyl ester resin and hydrogenated bisphenol A resin. The bisphenol A epoxy vinyl ester resin and the hydrogenated bisphenol A resin cooperate with each other to form a denser and more uniform cross-linked network structure during the film curing process. This not only improves the adhesion and impact resistance of the film, but also strengthens the internal chemical bond force, enabling the film to better resist the damage of external factors to its structure, thereby improving the corrosion resistance and water resistance of the film, and avoiding the influence of low-temperature curing moisture absorption and curing moisture absorption on the mechanical properties of the film.

[0014] Preferably, the bisphenol A epoxy vinyl ester resin is TM-V211 and / or Derakane™ 411; the hydrogenated bisphenol A resin includes one or more of AL-3040, SH-3000, and EP-4080E. To ensure excellent film performance, the mass ratio of the bisphenol A epoxy vinyl ester resin to the hydrogenated bisphenol A resin is 1:(1-2).

[0015] Further preferably, in order to improve the water resistance of the film and ensure the curing speed of the epoxy resin, the epoxy equivalent of the hydrogenated bisphenol A resin is 200-250g / mol.

[0016] In the present invention, the active diluent is a compound of cardanol-based active diluent and 4-epoxyisoeugenol. Although the cardanol-based active diluent can participate in the curing process, its curing speed is relatively slow, which 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 participating in the epoxy resin curing reaction, by adjusting the mass ratio of the two, the activity of the epoxy groups in the active diluent participating in the epoxy resin curing reaction can be regulated, thereby adjusting the curing speed of the coating, shortening the curing time of the coating, and improving the construction efficiency. The compounded active diluent with a small molecular mass can intersperse between the resin macromolecules, reducing the mutual entanglement between the macromolecules, greatly reducing the viscosity of the resin, and thus reducing the viscosity of the coating, improving the leveling property and wettability of the coating. Moreover, the compounded active diluent can chemically react with components such as epoxy resin and curing agent, becoming a part of the cross-linked network structure of the epoxy resin cured product, thereby enhancing the chemical bonding inside the coating, improving the adhesion and corrosion resistance of the paint film. The dense paint film supplemented with the hydrophobic groups introduced by the compounded active diluent 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 interpenetrates each other, making the coating have both flexibility and hardness, effectively improving the impact resistance and wear resistance of the coating, and reducing the erosion and damage of the external environment to the coating.

[0017] Preferably, the cardanol-based active diluent is selected from one or more of LITE 513DF, Ultra LITE 513, and NC-513.

[0018] More preferably, in order to shorten the curing time of the paint film and improve the coating performance, 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.

[0019] In the present invention, the dispersant is a compound of a polymer dispersant and polyurethane acrylate porous microspheres. The polyurethane acrylate porous microspheres can adsorb the reactive diluent through their porous structure and the polymer dispersant acting on the pigment, which can enhance the compatibility between the resin and the additives, adjust the viscosity and fluidity of the coating, improve the dispersion of pigment and filler particles in the coating system, and further improve the gloss and color strength of the paint film, avoiding problems such as color difference, spots, and streaks in the paint film. Further, the acrylate groups of the polyurethane acrylate porous microspheres act on the epoxy resin, the reactive diluent in the microsphere pores, and cardanol carbamate, increasing the tightness between the molecular chains of the paint film, making the coating cure more fully, and further enhancing the water resistance, corrosion resistance, and impact resistance of the coating. In addition, the polyurethane acrylate porous microspheres also interact with cardanol carbamate to strengthen the antibacterial properties of the coating and effectively inhibit the growth of microorganisms on the coating surface.

[0020] Preferably, the polymer dispersant is selected from one or more of Disperbyk™ 2028C, HY-7320, Disuper S9100, and AFCONA-4071; the particle size range of the polyurethane acrylate porous microspheres is 80-100 µm, the functionality of the polyurethane acrylate in the polyurethane acrylate porous microspheres is >3, and the mass ratio of the polymer dispersant to the polyurethane acrylate porous microspheres is (1-4):1.

[0021] In the present invention, the active groups in the modified alicyclic amine curing agent are used as the curing agent in the present invention because they can crosslink with the epoxy resin to form a network structure. Preferably, the modified alicyclic amine curing agent is WSG-228 and / or BS-1445.

[0022] In the present invention, when the amine value of the modified alicyclic amine curing agent is relatively 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 relatively low, the curing speed is relatively slow and the curing time is relatively long, but the paint film has high flexibility. 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.

[0023] In the present invention, a single modified alicyclic amine curing agent is adopted. However, during its use, the crosslinking and curing time is relatively long, which affects the construction progress. Moreover, the formed paint film is not ideal in terms of flexibility, corrosion resistance, etc. Therefore, in the present invention, the reaction active centers in the system are increased by introducing cardanol carbamate. These reaction active centers can attract and bring closer the active groups in the epoxy resin and the modified alicyclic amine curing agent, increasing the collision probability between the two, thereby accelerating the curing speed and shortening the curing time. Compared with simply relying on increasing the amine value or dosage of the modified alicyclic amine to accelerate the curing speed, the added cardanol carbamate not only forms stable chemical bonds through chemical reactions with the active groups in the epoxy resin, increasing the crosslinking density of the paint film, enhancing the corrosion resistance, adhesion and antioxidant properties of the paint film, but also the flexible groups contained therein can significantly improve the flexibility of the paint film, thus effectively avoiding the problem of the decline in the mechanical properties of the paint film caused by simply increasing the amine value or dosage of the modified alicyclic amine to accelerate the curing speed. In addition, the lipophilic active groups in cardanol carbamate cooperate with other components in the coating, reducing the surface tension of the paint film, enhancing the water resistance of the paint film, improving the fluidity of the coating and the compatibility of each component.

[0024] 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 GaoTai Coapur 830W, Crayvallac Optima, Crayvallac Ultra, and MT-6650; the pigment includes one or more of titanium dioxide, iron oxide red, and carbon black; the filler includes one or more of mica powder, talc powder, precipitated barium sulfate, and nano-silica.

[0025] The present invention also provides a preparation method of the solvent-free epoxy coating for drinking water tanks, including the following preparation steps:

[0026] (1) Dispersing epoxy resin, active diluent, dispersant, defoaming agent, thixotropic agent, pigment, and filler uniformly to obtain Component A;

[0027] (2) Adding a modified alicyclic amine curing agent to Component A, mixing uniformly, and then adding cardanol carbamate, and mixing and stirring to obtain the solvent-free epoxy coating.

[0028] The specific steps in step (1) include:

[0029] S1: Sequentially adding epoxy resin and active diluent into a dispersion kettle and dispersing uniformly;

[0030] S2: Sequentially adding the dispersant and the defoaming agent into the dispersion kettle and dispersing uniformly;

[0031] S3: Put the thixotropic agent into the dispersion kettle and disperse it evenly.

[0032] S4: Put the pigment and filler into the dispersion kettle in sequence. After dispersing evenly, transfer them to a grinding machine for grinding. Then add the dispersant and disperse at high speed for 30 min to obtain Component A.

[0033] Preferably, in steps S1, S2 and S3, the time of the dispersion stirring is 15 - 30 min, and the fineness of Component A in step S4 is ≤30 µm.

[0034] The technical solution of the present invention has the following advantages:

[0035] 1. The solvent - free epoxy coating for drinking water tanks provided by the present invention introduces cardanol carbamate as a curing reaction accelerator. By increasing the reaction active centers, the curing speed is accelerated; and by participating in the curing reaction, the cross - linking density of the paint film is enhanced, thereby improving the corrosion resistance, adhesion and antioxidant properties of the paint film. The introduction of flexible groups further improves the flexibility of the paint film. In addition, through the synergistic effect of cardanol carbamate and other components, the surface tension of the coating is reduced, the water resistance of the paint film is enhanced, and the fluidity of the coating and the compatibility of each component are improved.

[0036] 2. The present invention introduces the compounding of 4 - epoxy isoeugenol and cardanol - based reactive diluent as the reactive diluent. By adjusting the mass ratio of cardanol - based reactive diluent to 4 - epoxy isoeugenol, the curing speed of the coating can be adjusted, and the curing time of the coating can be shortened; the compounded reactive diluent not only acts on the epoxy resin system, reduces the viscosity of the system, improves the leveling property and wettability of the coating, but also participates in the curing to balance the flexibility and hardness of the paint film, improves the adhesion, water resistance, corrosion resistance and impact resistance of the paint film, and thus extends the service life of the paint film.

[0037] 3. The compounded reactive diluent and cardanol carbamate in the present invention act synergistically in the curing process of epoxy resin, further improving the curing speed, and endowing the coating with 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 can effectively resist bacteria, and is applicable to the inner walls of ship drinking water tanks, ballast tanks and various fresh water storage tanks. In addition, the compounded reactive diluent can also chemically react with cardanol carbamate to form a stable compound, thereby stabilizing the reactive diluent, greatly enhancing the stability and durability of the paint film performance, and effectively extending the service life of the drinking water tank.

[0038] 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

[0039] 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.

[0040] 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.

[0041] The polyurethane acrylate porous microspheres used in the present invention are prepared according to the method disclosed in CN115572530B. Example 1

[0042] The present invention provides a solvent-free epoxy coating for a drinking water tank, comprising a component A and a component B:

[0043] 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).

[0044] 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.

[0045] The preparation method of the solvent-free epoxy coating for the drinking water tank includes:

[0046] S1: Add 20 parts of AL-3040 (hydrogenated bisphenol A 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 reactive diluent), and 1 part of 4-epoxyisoeugenol (reactive diluent) into the dispersion kettle in sequence, and disperse for 15 - 30 min;

[0047] S2: Add 0.2 part of Disperbyk™ 2028C (polymeric dispersant) and 0.5 part of BYK-060 (defoamer) into the dispersion kettle in sequence, and disperse for 15 - 30 min;

[0048] S3: Add 1.2 parts of High-Tech Coapur 830W (thixotropic agent) into the dispersion kettle, and disperse at high speed for 15 - 30 min;

[0049] S4: Add 35 parts of iron oxide red (pigment) and 10 parts of mica powder with 1250 mesh (filler) into the dispersion kettle in sequence. After dispersing evenly, transfer to a grinding machine and grind until the fineness ≤ 30 µm. Then add 0.1 part of polyurethane acrylate porous microspheres (dispersant), and disperse at high speed for 30 min to obtain Component A;

[0050] S5: Add 23 parts of WSG-228 (modified alicyclic amine curing agent) to Component A, mix evenly, and then add 7 parts of cardanol carbamate. Among them, the mass ratio of Component A to Component B is 3:1. After stirring and dissolving, the solvent-free epoxy coating is obtained. Example 2

[0051] The present invention provides a solvent-free epoxy coating for a drinking water tank, including Component A and Component B:

[0052] The raw materials of Component A are in parts by weight, including: 30 parts of SH-3000 (hydrogenated bisphenol A resin), 20 parts of TM-V211 (bisphenol A epoxy vinyl ester resin), 8 parts of Ultra LITE 513 (cardanol-based reactive diluent), 2 parts of 4-epoxyisoeugenol (reactive diluent), 0.2 part of HY-7320 (polymeric dispersant), 0.2 part of polyurethane acrylate porous microspheres (dispersant), 0.1 part of BYK-1799 (defoamer), 0.8 part of MT-6650 (thixotropic agent), 23 parts of BLR-895 (pigment), 12 parts of mica powder with 1250 mesh (filler), and 4 parts of precipitated barium sulfate (filler).

[0053] The raw materials of Component B are in parts by weight, including: 13 parts of BS-1445 (modified alicyclic amine curing agent) and 7 parts of cardanol carbamate.

[0054] The preparation method of the solvent-free epoxy coating for the above-mentioned drinking water tank includes:

[0055] S1: Add 30 parts of SH-3000 (hydrogenated bisphenol A resin), 20 parts of TM-V211 (bisphenol A epoxy vinyl ester resin), 8 parts of Ultra LITE 513 (cardanol-based reactive diluent), and 2 parts of 4-epoxyisoeugenol (reactive diluent) into the dispersion kettle in sequence, and disperse for 15 - 30 min;

[0056] S2: Add 0.2 part of HY-7320 (polymer dispersant) and 0.1 part of BYK-1799 (defoamer) into the dispersion kettle in sequence, and disperse for 15 - 30 min;

[0057] S3: Add 0.8 part of MT-6650 (thixotropic agent) into the dispersion kettle, and disperse at high speed for 15 - 30 min;

[0058] S4: Add 23 parts of BLR-895 (pigment), 12 parts of mica powder with 1250 mesh (filler), and 4 parts of precipitated barium sulfate (filler) into the dispersion kettle in sequence. After dispersing evenly, transfer to a grinding machine and grind until the fineness ≤ 30 µm. Then add 0.2 part of polyurethane acrylate porous microspheres (dispersant), and disperse at high speed for 30 min to obtain Component A;

[0059] S5: Add 13 parts of BS-1445 (modified alicyclic amine curing agent) to Component A, mix evenly, and then add 7 parts of cardanol carbamate. Among them, the mass ratio of Component A to Component B is 5:1. After stirring and dissolving, the solvent-free epoxy coating is obtained. Example 3

[0060] The present invention provides a solvent-free epoxy coating for a drinking water tank, including Component A and Component B:

[0061] 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).

[0062] 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.

[0063] The preparation method of the solvent-free epoxy coating for the drinking water tank comprises:

[0064] 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;

[0065] 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;

[0066] 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;

[0067] S4: Put 20 parts of carbon black (pigment), 15 parts of nano-silica (filler), and 5 parts of precipitated barium sulfate (filler) into the dispersion kettle in sequence. After uniform dispersion, transfer it to a grinder and grind it until the fineness is ≤30 µm. Then put in 0.1 part of polyurethane acrylate porous microspheres (dispersant) and disperse at high speed for 30 min to obtain Component A;

[0068] 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. After mixing evenly, add 2 parts of cardanol carbamate. Among them, the mass ratio of Component A to Component B is 10:1. After stirring and dissolving, the solvent-free epoxy coating is obtained.

[0069] Comparative Example 1

[0070] This comparative example provides a solvent-free epoxy coating for drinking water tanks. The difference from Example 2 is that in this comparative example, an equal amount of the modified alicyclic amine curing agent BS-1445 is used to replace cardanol carbamate.

[0071] Comparative Example 2

[0072] This comparative example provides a solvent-free epoxy coating for drinking water tanks. The difference from Example 2 is that in this comparative example, an equal amount of the cardanol-based reactive diluent Ultra LITE 513 is used to replace 4-epoxyisoeugenol.

[0073] Comparative Example 3

[0074] This comparative example provides a solvent-free epoxy coating for drinking water tanks. The difference from Example 2 is that in this comparative example, an equal amount of the polymer dispersant HY-7320 is used to replace the polyurethane acrylate porous microspheres.

[0075] Comparative Example 4

[0076] This comparative example provides a solvent-free epoxy coating for drinking water tanks. The difference from Example 2 is that in this comparative example, an equal amount of bisphenol A epoxy resin DER 331 is used to replace the hydrogenated bisphenol A resin SH-3000 and bisphenol A epoxy vinyl ester resin TM-V211.

[0077] In the present invention, the coatings of Examples 1-3 and Comparative Examples 1-4 are respectively used to prepare a coating film with a thickness of 100 ± 20 µm on a steel substrate, and performance tests are carried out. The test results are shown in Table 1.

[0078] Table 1 Performance test methods of coatings and performance test results of solvent-free epoxy coatings

[0079]

[0080] 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 applicable to the inner walls of ship drinking water tanks, ballast tanks and various fresh water storage tanks.

[0081] By comparing Comparative Example 1 and Example 2, it was found that adding cardanol carbamate to the solvent-free epoxy coating enhanced the salt spray resistance, water resistance, adhesion and flexibility of the paint film, and increased the curing speed.

[0082] By comparing Comparative Example 2 and Example 2, it was found that the cardanol-based reactive diluent and 4-epoxyisoeugenol were compounded as reactive diluents, which improved the impact resistance, adhesion, water resistance and salt spray resistance of the paint film, and thus ensured the stability and durability of the coating system performance.

[0083] By comparing Comparative Examples 1 and 2 with Example 2, it was found that the compounded reactive diluent and cardanol carbamate synergistically enhanced the antibacterial properties of the coating and increased the curing speed.

[0084] By comparing Comparative Example 3 and Example 2, it was found that the compounding of polyurethane acrylate porous microspheres and a polymer dispersant enhanced the gloss stability, water resistance and impact resistance of the paint film; comparing Comparative Examples 1 and 3 with Example 2, the interaction between polyurethane acrylate porous microspheres and cardanol carbamate strengthened the corrosion resistance and impact resistance of the coating and improved the antibacterial properties of the coating.

[0085] By comparing Comparative Example 4 and Example 2, it was found that the synergistic effect of hydrogenated bisphenol A resin and bisphenol A epoxy vinyl ester resin was beneficial to enhancing the adhesion, impact resistance, water resistance and salt spray resistance of the paint film.

[0086] Obviously, the above embodiments are merely examples given for clear illustration and are not limitations on the implementation manners. For those of ordinary skill 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 manners here. And the obvious changes or modifications derived therefrom still fall within the protection scope 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 mass ratio of the polymer dispersant to the polyurethane acrylate porous microspheres is (1-4): 1; 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 a drinking water tank according to claim 1, wherein The cardanol-based active diluent includes one or more of LITE 513DF, Ultra LITE 513, and NC-513.

3. The solvent-free epoxy coating for a drinking water tank 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. A solvent-free epoxy coating for a drinking water tank, 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 a drinking water tank 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. A solvent-free epoxy coating for a drinking water tank, 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. A solvent-free epoxy coating for a drinking water tank, characterized in that, The modified alicyclic amine curing agent is WSG-228 and / or BS-1445.

8. A solvent-free epoxy coating for a drinking water tank, 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 preparation method of the solvent-free epoxy coating for drinking water tanks according to any one of claims 1-8, 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. After mixing evenly, add cardanol carbamate and mix and stir to obtain a solvent-free epoxy coating.

10. The preparation method of the solvent-free epoxy coating for drinking water tanks according to claim 9, characterized in that, The fineness of the said Component A ≤ 30 µm.

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