A high solid low voc alkyd resin, its preparation method and a quick drying alkyd paint

Abstract

This application belongs to the field of resin technology, specifically relating to a high-solids-content, low-VOC alkyd resin, its preparation method, and a fast-drying alkyd coating. The high-solids-content, low-VOC alkyd resin comprises the following components in parts by weight: 15-20 parts of sulfonate monomer, 13-18 parts of soybean oil fatty acid, 5-10 parts of glycerol, 5-10 parts of pentaerythritol, 5-10 parts of phthalic anhydride, 5-10 parts of rosin, 8-10 parts of solvent A, and 0.1-0.3 parts of additives. This high-solids-content, low-VOC alkyd resin, when applied to alkyd coatings, can solve the problems of high volatile organic compound (VOC) emissions and slow drying speed associated with traditional alkyd resins.

Description

Technical Field

[0001] This application belongs to the field of resin technology, specifically relating to a high-solids-content, low-VOC alkyd resin, its preparation method, and a fast-drying alkyd coating. Background Technology

[0002] Alkyd resins, as a widely used basic resin in the coatings industry, have occupied an important position in various fields such as construction, industrial coating, automobile manufacturing, and furniture since their introduction, thanks to their significant advantages such as renewable raw materials, low cost, excellent workability, and both rust prevention and weather resistance. They have become the core material for various protective and decorative coatings. The widespread application of alkyd resins is due to their good film-forming properties and adaptability, which can meet the protective needs of different environments.

[0003] Traditional alkyd resins mostly use organic solvents as a medium, resulting in high emissions of volatile organic compounds (VOCs) during use. This not only causes air pollution and health hazards but also exacerbates the greenhouse effect, seriously contradicting current global environmental policies and green development strategies. Furthermore, traditional alkyd resins suffer from poor application viscosity, leading to poor leveling, brush marks, or drips during coating, affecting coating quality and efficiency. Simultaneously, traditional alkyd coatings also suffer from slow drying speeds and low application efficiency, especially in mass production, extending lead times and increasing costs.

[0004] Therefore, this application provides a high-solids-content, low-VOC alkyd resin, its preparation method, and a fast-drying alkyd coating. Summary of the Invention

[0005] In view of this, this application provides a high-solids-content, low-VOC alkyd resin, its preparation method, and a fast-drying alkyd coating. This high-solids-content, low-VOC alkyd resin, when applied to alkyd coatings, can solve the problems of high volatile organic compound (VOC) emissions and slow drying speed of traditional alkyd resins.

[0006] According to a first aspect of this application, a high-solids-content, low-VOC alkyd resin is provided, comprising the following components in parts by weight:

[0007] Sulfonate type monomer 15-20 parts, soybean oil fatty acid 13-18 parts, glycerol 5-10 parts, pentaerythritol 5-10 parts, phthalic anhydride 5-10 parts, rosin 5-10 parts, solvent A 8-10 parts, auxiliaries 0.1-0.3 parts;

[0008] The sulfonate monomer is prepared by reacting sodium isophthalate-5-sulfonate and neopentyl glycol at a molar ratio of 1:2.1 to 2.2 at 190°C to 200°C.

[0009] In some embodiments, the high-solids, low-VOC alkyd resin comprises the following components in parts by weight:

[0010] Sulfonate type monomer 16-18 parts, soybean oil fatty acid 14-16 parts, glycerol 6-9 parts, pentaerythritol 6-9 parts, phthalic anhydride 6-9 parts, rosin 6-9 parts, solvent A 8-10 parts, and auxiliary agent 0.1-0.3 parts.

[0011] In some embodiments, the additive includes at least one of a dispersant and a defoamer;

[0012] And / or, the solvent A comprises paint solvent oil No. 200 and xylene, wherein the weight ratio of paint solvent oil No. 200 to xylene is 80:20.

[0013] In some embodiments, the preparation process of the sulfonate monomer includes the following steps:

[0014] Neopentyl glycol was fed in a specific molar ratio, a catalyst was added, and the neopentyl glycol was heated to melt. Sodium isophthalic acid-5-sulfonate was then added, and the reaction was carried out at 190℃~200℃. When the acid value of the reaction system was ≤1.5mg KOH / g, the reaction reached its endpoint, and the reaction was stopped to obtain the sulfonate type monomer.

[0015] In some embodiments, the catalyst is dibutyltin dilaurate, and the amount of dibutyltin dilaurate added is 1.4% to 1.6% of the total mass of neopentyl glycol and sodium isophthalate-5-sulfonate.

[0016] According to a second aspect of this application, a method for preparing the high-solids-content, low-VOC alkyd resin described in the first aspect is provided, comprising the following steps:

[0017] (1) Add sulfonate type monomer, soybean oil fatty acid, glycerol, pentaerythritol, phthalic anhydride, rosin and additives into the reactor according to the weight parts, stir and heat up to 150-155℃ and keep at 1h, heat up to 180-185℃ and keep at 2h, and heat up to 210-220℃ in 2-4h; during this process, take a sample to test its acid value, and stop heating when the acid value is lower than 12mg KOH / g;

[0018] (2) Cool the reaction product of step (1) to 100°C, add solvent A for dilution, stir evenly, and filter to obtain alkyd resin with high solid content and low VOC.

[0019] According to a third aspect of this application, an alkyd coating comprises the following components in parts by weight:

[0020] 30-40 parts alkyd resin, 10-15 parts tackifying resin, 10-15 parts pigment, 30-35 parts filler, 10-15 parts solvent B, and 0.8-1 part boron-zinc-cobalt drying agent;

[0021] The alkyd resin is the alkyd resin described in the first aspect or the alkyd resin prepared by the preparation method described in the second aspect;

[0022] The preparation process of the boron-zinc-cobalt drying agent includes: dissolving Zn(NO3)2·6H2O, Co(NO3)2·6H2O, and NH4HCO3 in water, and then carrying out a first hydrothermal reaction to obtain a precursor; calcining the precursor, followed by boric acid treatment and a second hydrothermal reaction to obtain the boron-zinc-cobalt drying agent.

[0023] In some embodiments, the preparation process of the boron-zinc-cobalt drying agent satisfies at least one of the following conditions:

[0024] (1) The molar ratio of Zn(NO3)2·6H2O, Co(NO3)2·6H2O, and NH4HCO3 is 1:2:(20-25);

[0025] (2) The conditions for the first hydrothermal reaction are to react at 180℃~190℃ for 10~12h;

[0026] (3) The calcination treatment conditions are calcination at 600℃~700℃ for 5~7h, and then cooling to room temperature;

[0027] (4) The conditions for boric acid treatment are as follows: disperse the calcined precursor in water, then add boric acid, and stir for 30 minutes after the boric acid is completely dissolved; the mass ratio of the calcined precursor to boric acid is 1:0.6.

[0028] (5) The conditions for the second hydrothermal reaction are: react at 180℃~190℃ for 10~12h.

[0029] In some embodiments, the tackifying resin is hydrogenated rosin glycerol ester.

[0030] In some embodiments, the filler includes at least one of barium sulfate, calcium carbonate, zinc phosphate, and aluminum tripolyphosphate.

[0031] The beneficial effects of this application are:

[0032] The high-solids, low-VOC alkyd resin described in this application uses specific weight proportions of sulfonate monomers, soybean oil fatty acids, glycerol, pentaerythritol, phthalic anhydride, rosin, solvent A, and additives to impart excellent dispersibility to the alkyd resin. The alkyd resin exhibits high solids content and low VOCs. The alkyd coating formed by combining the alkyd resin with tackifying resins, pigments, fillers, solvents, and boron-zinc-cobalt driers not only dries quickly, achieving surface and complete drying in a short time, significantly shortening the construction cycle and improving construction efficiency, but also possesses strong adhesion, firmly adhering to various substrate surfaces and resisting peeling. Furthermore, it exhibits excellent weather resistance, enduring long-term exposure to wind, sun, and rain without easily showing signs of chalking, discoloration, or cracking. In addition, it has good chemical corrosion resistance, exhibiting a certain degree of resistance to common acids, alkalis, and salts, thus extending the service life of the coating. Detailed Implementation

[0033] To make the objectives, technical solutions, and advantages of this application clearer, the following detailed description is provided in conjunction with embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the scope of this application.

[0034] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "illustrative embodiment," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with an embodiment or example is included in at least one embodiment or example of this application. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0035] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this application, "multiple" means at least two, such as two, three, etc., unless otherwise explicitly specified.

[0036] Traditional alkyd resins suffer from problems such as high VOC emissions and slow drying speed. Therefore, in a first aspect, this application provides a high-solids-content, low-VOC alkyd resin, comprising the following components in parts by weight:

[0037] Sulfonate type monomer 15-20 parts, soybean oil fatty acid 13-18 parts, glycerol 5-10 parts, pentaerythritol 5-10 parts, phthalic anhydride 5-10 parts, rosin 5-10 parts, solvent A 8-10 parts, auxiliaries 0.1-0.3 parts;

[0038] The sulfonate monomer is prepared by reacting sodium isophthalate-5-sulfonate and neopentyl glycol at a molar ratio of 1:2.1 to 2.2 at 190°C to 200°C.

[0039] In some embodiments, the sulfonate monomer is present in a weight range of 15 to 20 parts, preferably 16 to 18 parts by weight. For example, the weight range of the sulfonate monomer can be 15, 16, 17, 18, 19, or 20 parts, or any range defined by both. When the mass content of the sulfonate monomer is controlled within the above range, the sulfonic acid groups provided by the sulfonate monomer impart excellent dispersibility to the resin, thereby significantly reducing the emission of volatile organic compounds (VOCs) during application, meeting environmental protection requirements. In addition, the sulfonate monomer can effectively improve the corrosion resistance of the resin, enabling it to maintain excellent performance in various complex environments, extending its service life, and meeting high-standard application requirements.

[0040] In some embodiments, the soybean oil fatty acid content is 13 to 18 parts by weight, preferably 14 to 16 parts by weight. For example, the soybean oil fatty acid content can be 13, 14, 15, 16, 17, or 18 parts by weight, or a range defined by any two thereof. When the soybean oil fatty acid content is controlled within the above range, the soybean oil fatty acid can effectively provide abundant unsaturated fatty acid components, which not only helps to improve the drying efficiency of the alkyd resin system and shorten the surface curing time, but also significantly enhances the flexibility and extensibility of the coating film. At the same time, adding soybean oil fatty acid can further improve the adhesion of the coating film to the substrate and improve its weather resistance, enabling it to maintain a stable surface state and long-term protective effect under various environmental conditions.

[0041] In some embodiments, the glycerol content is 5 to 10 parts by weight, preferably 6 to 9 parts by weight; for example, the glycerol content can be 5, 6, 7, 8, 9, or 10 parts by weight, or any range defined by both of these. When the glycerol content is controlled within the above range, it can effectively participate in the esterification reaction, reacting with the acid component to form ester bonds, thereby adjusting the molecular weight distribution and crosslinking density of the alkyd resin. This helps control the hardness and flexibility of the alkyd resin, significantly improving its leveling properties, resulting in a smoother and more uniform coating surface, while also enhancing film-forming properties and improving the adhesion and durability of the coating. Furthermore, the hydrophilicity and reactivity of glycerol also help optimize the stability and application performance of the alkyd resin.

[0042] In some embodiments, the pentaerythritol is present in parts by weight of 5 to 10, preferably 6 to 9; for example, the pentaerythritol may be present in parts by weight of 5, 6, 7, 8, 9, or 10, or any range defined by both thereof. When the mass content of pentaerythritol is controlled within the above range, pentaerythritol, as a highly functional polyol, contains up to four hydroxyl groups in its molecular structure, which can significantly participate in the esterification reaction process, effectively increasing the crosslinking density and final hardness of the alkyd resin system, thereby improving the wear resistance and chemical corrosion resistance of the coating film, making it more suitable for high mechanical loads and corrosive environments.

[0043] In some embodiments, the phthalic anhydride is 5 to 10 parts by weight, preferably 6 to 9 parts by weight; for example, the phthalic anhydride can be 5, 6, 7, 8, 9, or 10 parts by weight, or any range defined by both of these. When the mass content of phthalic anhydride is controlled within the above range, it provides carboxyl functional groups, which affect the degree of esterification and crosslinking network structure of the alkyd resin. This not only helps to improve the overall hardness and scratch resistance of the coating film, but also significantly enhances the surface gloss and its adhesion to various substrates, improving the appearance and durability of the coating.

[0044] In some embodiments, the rosin is 5 to 10 parts by weight, preferably 6 to 9 parts by weight; for example, the rosin can be 5, 6, 7, 8, 9, or 10 parts by weight, or any range defined by both of these. When the rosin content is controlled within the above range, rosin, as a natural resin component, can effectively improve the gloss and flexibility of the alkyd resin system, while enhancing the spreading and adhesion of the coating film on the substrate. Its introduction can also improve the impact resistance and outdoor weather resistance of the coating film, and reduce cracking or chalking caused by temperature changes or ultraviolet radiation.

[0045] In some embodiments, the additive is present in a weight ratio of 0.1 to 0.3 parts; for example, the additive may be present in a weight ratio of 0.1, 0.2, or 0.3 parts, or a range defined by any two thereof. The additive may be selected from one or more dispersants and defoamers used in combination. Controlling the mass content of the additive within the above range can optimize the application performance of the alkyd resin, reduce surface defects such as pinholes and bubbles in the paint film, and ensure a smooth and aesthetically pleasing coating.

[0046] In some embodiments, the weight of solvent A is 8 to 10 parts: for example, the weight of solvent A can be 8, 9, or 10 parts, or any range defined by both of these. When the mass content of solvent A is controlled within the above range, the viscosity of alkyd resin can be effectively adjusted, giving it good flowability and brushability during construction, making it easy to coat evenly on the substrate surface. At the same time, it can also promote the dispersion and fusion of various components in the resin, improve the stability and compatibility of the resin, help form a uniform and dense paint film, and further improve the appearance quality and protective performance of the paint film.

[0047] Furthermore, solvent A comprises paint solvent oil No. 200 and xylene, with a weight ratio of paint solvent oil No. 200 to xylene of 80:20. This reduces the content of volatile organic compounds (VOCs) in the coating and has strong dissolving power, enabling it to quickly dissolve alkyd resins, shorten the coating preparation cycle, and improve production efficiency. In addition, solvent A also has good drying properties, which helps to accelerate the drying speed of the paint film, shorten the construction waiting time, and improve the overall construction efficiency.

[0048] In some embodiments, the sulfonate monomer is prepared by reacting sodium isophthalate-5-sulfonate and neopentyl glycol at a molar ratio of 1:2.1 to 2.2 at 190°C to 200°C.

[0049] In some examples, the preparation process of the sulfonate monomer includes the following steps:

[0050] Neopentyl glycol was fed in a specific molar ratio, a catalyst was added, and the neopentyl glycol was heated to melt. Sodium isophthalic acid-5-sulfonate was then added, and the reaction was carried out at 190℃~200℃. When the acid value of the reaction system was ≤1.5mg KOH / g, the reaction reached its endpoint, and the reaction was stopped to obtain the sulfonate type monomer.

[0051] The catalyst is dibutyltin dilaurate, and the amount of dibutyltin dilaurate added is 1.4% to 1.6% of the total mass of neopentyl glycol and sodium isophthalic acid-5-sulfonate. For example, the amount of dibutyltin dilaurate added can be 1.4%, 1.5%, or 1.6% of the total mass of neopentyl glycol and sodium isophthalic acid-5-sulfonate, or a range defined by any two of them.

[0052] The preparation process of sulfonate monomers involves the following chemical reactions:

[0053] .

[0054] According to a second aspect of this application, a method for preparing the above-mentioned high-solids-content, low-VOC alkyd resin is provided, comprising the following steps:

[0055] (1) Add sulfonate monomers, soybean oil fatty acids, glycerol, pentaerythritol, phthalic anhydride, rosin, and additives to the reactor according to the weight parts, stir and heat up to 150-155℃ and keep at 1h, heat up to 180-185℃ and keep at 2h, and heat up to 210-220℃ in 2-4h; during this process, take a sample to test its acid value, and stop heating when the acid value is lower than 12mg KOH / g;

[0056] (2) Cool the reaction product of step (1) to 100°C, add solvent A (i.e., paint solvent oil No. 200 and xylene (weight ratio 80 / 20)) to dilute, stir evenly, filter, and obtain alkyd resin with high solid content and low VOC.

[0057] According to a third aspect of this application, an alkyd coating is provided, comprising the following components in parts by weight:

[0058] 30-40 parts alkyd resin, 10-15 parts tackifying resin, 10-15 parts pigment, 30-35 parts filler, 10-15 parts solvent B, and 0.8-1 part boron-zinc-cobalt drying agent;

[0059] The alkyd resin is the alkyd resin of the first aspect or the alkyd resin prepared by the preparation method of the second aspect;

[0060] The preparation process of the boron-zinc-cobalt drying agent includes: dissolving Zn(NO3)2·6H2O, Co(NO3)2·6H2O, and NH4HCO3 in water, and then carrying out a first hydrothermal reaction to obtain a precursor; calcining the precursor, followed by boric acid treatment and a second hydrothermal reaction to obtain the boron-zinc-cobalt drying agent.

[0061] In some embodiments, the boron-zinc-cobalt drier is 0.8 to 1 part; for example, the alkyd coating may include the boron-zinc-cobalt drier in the following weight amounts: 0.8, 0.9, 1, or a range defined by any two thereof.

[0062] In some embodiments, the molar mass (in mol) ratio of Zn(NO3)2·6H2O, Co(NO3)2·6H2O, and NH4HCO3 is 1:2:(20-25); this drier can not only effectively accelerate the drying of the coating, but also improve the overall performance of the coating to a certain extent, such as enhancing the adhesion and gloss of the coating film.

[0063] In some embodiments, the conditions for the first hydrothermal reaction are to react at 180°C to 190°C for 10 to 12 hours. The chemical reactions involved in the first hydrothermal reaction are as follows:

[0064] Zinc nitrate and cobalt nitrate react with ammonium bicarbonate under hydrothermal conditions to form carbonate precursors:

[0065] Zn(NO3)2+2NH4HCO3→ZnCO3+2NH4NO3+CO2+H2O;

[0066] Co(NO3)2+2NH4HCO3→CoCO3+2NH4NO3+CO2+H2O;

[0067] Zn 2+ and Co 2+ With HCO3 - The reaction produces the corresponding carbonate precipitate, while releasing NH3, CO2 and H2O, forming a porous structure.

[0068] In some embodiments, the calcination treatment is carried out at 600°C to 700°C for 5 to 7 hours, followed by cooling to room temperature; the chemical reactions involved in the calcination process include:

[0069] ZnCO3+2CoCO3+1 / 2O2→ZnCo2O4+3CO2;

[0070] The carbonate precursor is calcined in air, decomposed and oxidized to ZnCo2O4 with a spinel structure.

[0071] In some embodiments, the boric acid treatment conditions are as follows: the calcined precursor is dispersed in water, then boric acid is added, and after the boric acid is completely dissolved, the mixture is stirred for 30 minutes; the mass ratio of the calcined precursor to boric acid is 1:0.6; the conditions for the second hydrothermal reaction are as follows: the reaction is carried out at 180℃~190℃ for 10~12 hours.

[0072] Boron doping was achieved by reacting ZnCo2O4 with boric acid (H3BO3) under hydrothermal conditions, thereby introducing oxygen vacancies (Ov).

[0073] ZnCo2O4 + xH3BO3 → B x -ZnCo2O 4-x + x H2O + Ov;

[0074] Ov represents an oxygen vacancy, where a B atom partially replaces an O site or enters an interstitial site, leading to changes in electronic structure and the formation of oxygen vacancies.

[0075] In this application, during the preparation of the boron-zinc-cobalt drying agent, a first hydrothermal reaction forms a carbonate precursor, which is then calcined to form ZnCo2O4. ZnCo2O4 is then treated with boric acid and subjected to a second hydrothermal reaction to achieve element doping. Through two hydrothermal reactions and calcination treatments, a composite metal oxide structure with highly dispersed boron, zinc, and cobalt elements is successfully constructed. Compared with traditional simple metal salt drying agents, this agent can more efficiently catalyze the oxidative crosslinking reaction of unsaturated fatty acids in the paint film and fill the paint film network to enhance its density. This significantly shortens the drying time while synergistically improving the corrosion resistance and mechanical strength of the coating.

[0076] In some embodiments, the alkyd resin comprises 30 to 40 parts by weight. For example, the alkyd coating may include the alkyd resin in the following weight proportions: 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40, or a range defined by any two thereof. In this application, alkyd resins within the above range are selected as the main film-forming substance, providing good adhesion, gloss, and drying performance.

[0077] In some embodiments, the tackifying resin is 10 to 15 parts. For example, the alkyd coating may include the tackifying resin in the following weight proportions: 10, 11, 12, 13, 14, 15, or a range defined by any two thereof. In this application, the tackifying resin selected within the above range can increase the viscosity of the alkyd coating, enhance the adhesion and flexibility of the coating film, and improve the leveling properties of the coating film.

[0078] In some embodiments, the pigment comprises 10 to 15 parts by weight. For example, the alkyd coating may include the pigment in weights of 10, 11, 12, 13, 14, 15, or a range defined by any two thereof. The pigment imparts color and hiding power to the coating. By selecting pigments within the above range, the pigment can fully utilize its color characteristics to achieve the ideal color expression of the coating, while ensuring an appropriate dosage to enhance the stability of the coating system, avoid sedimentation and clumping, and provide sufficient hiding power and color saturation. Furthermore, a suitable pigment content helps optimize the rheological properties of the coating, ensuring smooth brushing or spraying during application, ultimately forming a uniform and smooth paint film.

[0079] In some embodiments, the filler comprises 30 to 35 parts by weight. For example, the alkyd coating may include the filler in the following weight proportions: 30, 31, 32, 33, 34, 35, or a range defined by any two thereof. Specifically, the filler includes precipitated barium sulfate (to improve film hardness and chemical resistance), zinc phosphate (to provide rust prevention), and aluminum tripolyphosphate (to enhance rust prevention and corrosion resistance). The filler can increase film thickness and improve hardness and abrasion resistance. By selecting fillers within the above range, the filler can be uniformly dispersed in the coating system, which helps maintain suitable viscosity, thereby ensuring good workability. At the same time, this dosage can effectively improve film thickness and hardness, ensuring that it achieves the expected mechanical reinforcement effect. In addition, an appropriate filler content can further enhance the adhesion of the coating, making the film bond firmly to the substrate, and improving the overall durability and service life of the coating.

[0080] In some embodiments, solvent B is 10 to 15 parts. For example, the alkyd coating may include the solvent in the following weight proportions: 10, 11, 12, 13, 14, 15, or a range defined by any two thereof. Specifically, solvent B comprises paint solvent oil No. 200 and xylene (weight ratio 80 / 20). Solvent B adjusts the viscosity of the coating, facilitating application and reducing application difficulty. Using solvents within the above range ensures excellent flowability and application performance of the coating, allowing it to spread smoothly during application and easily form a smooth, defect-free film. This dosage also helps maintain a suitable drying rate, ensuring application efficiency.

[0081] The alkyd resin described in this application will be further described below with reference to specific embodiments. The raw materials in the following embodiments can all be obtained through commercial means, but are only used to illustrate this application, and the scope of this application is not limited to these specific embodiments.

[0082] Test methods and equipment

[0083] 1. Acid value

[0084] Blank test: In a clean conical flask, add 10 mL of anhydrous ethanol and 10 mL of toluene sequentially, and mix well. Add 3-5 drops of phenolphthalein indicator, and titrate with a standardized KOH-ethanol standard solution until the solution turns slightly pink and remains so for 30 seconds. Record the volume of KOH consumed at this point as V0 (mL).

[0085] Sample determination: Accurately weigh approximately 1 g (accurate to 0.0001 g) of the resin sample to be tested using an analytical balance and place it in the conical flask from which the blank test has been completed. Seal the mouth of the flask with plastic wrap, place it on an electric heater, and heat it while continuously shaking it to ensure that the sample is completely dissolved in the mixed solvent. Stop heating and allow the conical flask to cool to room temperature.

[0086] Titrate with KOH-ethanol standard solution to the same faint pink endpoint as the blank test, and maintain the color for 30 seconds. Record the total volume of KOH consumed as V1 (mL).

[0087] Result Calculation

[0088] The acid value (AV) of the sample is calculated using the following formula:

[0089] AV = 56.1 × c × (V1 - V0) / m

[0090] in:

[0091] AV: Acid value of the sample (mg KOH / g);

[0092] c: Concentration of KOH-ethanol standard solution (mol / L), for example, a 0.1 mol / L KOH-ethanol standard solution can be selected;

[0093] V1: Volume of KOH solution consumed in the titration of the sample (mL);

[0094] V0: Volume of KOH solution consumed in the blank test (mL);

[0095] m: Mass of the sample (g).

[0096] 2. Solid content test

[0097] The test was conducted in accordance with GB / T 1725-2007 "Determination of nonvolatile matter content in paints, varnishes and plastics".

[0098] 3. VOC content testing

[0099] The test was conducted according to GB / T 23986-2009 "Determination of VOC Content in Paints and Varnishes by Gas Chromatography".

[0100] 4. Gloss

[0101] The gloss was measured at 60° according to GB / T 9754-2007 "Determination of specular gloss of paint films without metallic pigments".

[0102] 5. Hardness

[0103] The test was conducted using a pencil hardness tester, in accordance with GB / T 6739-2006 "Determination of Hardness of Paints and Varnishes by Pencil Method".

[0104] 6. Adhesion

[0105] The cross-cut test was conducted according to GB / T 9286-2021 "Cross-cut test for paints and varnishes", and the rating was 0-5.

[0106] 7. Salt spray resistant

[0107] The test was conducted according to GB / T 1771-2007 "Determination of resistance to neutral salt spray of paints and varnishes", using a 5% NaCl solution, and the changes in the paint film were observed three times a day.

[0108] 8. Quick-drying time

[0109] Perform the test according to GB / T 1728-2020 "Determination of Drying Time of Paint Film and Putty Film", and record the surface drying and complete drying times.

[0110] 9. Impact resistance

[0111] Perform the test according to GB / T 1732-2020 "Test Method for Impact Resistance of Coating Film", and record whether the coating film cracks or peels off after impact.

[0112] Example 1-1: A method for preparing high-solids, low-VOC alkyd resin, comprising the following steps:

[0113] (1) Add the following by weight: 15 parts of sulfonate monomer, 13 parts of soybean oil fatty acid, 5 parts of glycerol, 5 parts of pentaerythritol, 5 parts of phthalic anhydride, 5 parts of rosin, 8 parts of paint solvent oil No. 200 and xylene (weight ratio 80 / 20), and 0.1 parts of additive (organosilicon defoamer) into the reactor. Stir and heat up to 150°C for 1 hour, then heat up to 180°C for 2 hours, and then heat up to 210°C within 2 hours. During this process, take a sample to test its acid value. Stop heating when the acid value is lower than 12 mg KOH / g.

[0114] (2) Cool the reaction product of step (1) to 100°C, add paint solvent oil No. 200 and xylene (weight ratio 80 / 20) to dilute, stir evenly, filter, and obtain alkyd resin with high solid content and low VOC.

[0115] The preparation process of sulfonate monomers includes the following steps:

[0116] Take a clean 1000mL four-necked flask, add 1.05mol of neopentyl glycol and dibutyltin dilaurate, set up the experimental apparatus and turn on the cooling water, heating device and stirring device. Heat the flask to 120℃. After the neopentyl glycol in the flask is in a molten state, weigh out 0.5mol of sodium isophthalic acid-5-sulfonate and add it through the feed port. At the same time, install a water separator to collect the H2O obtained from the reaction. Start heating at a rate of 20℃ / h. After the temperature reaches 190℃, keep it at this temperature and carefully observe the amount of water flowing out and the state in the flask. React for about 1 hour. After the reactants in the flask become transparent, take a sample to measure its acid value. When the acid value is less than 1.5mg KOH / g, cool to room temperature to obtain the sulfonate type monomer. The amount of dibutyltin dilaurate added is 1.4% of the total mass of neopentyl glycol and sodium isophthalic acid-5-sulfonate.

[0117] Examples 1-2: A method for preparing high-solids, low-VOC alkyd resin, comprising the following steps:

[0118] (1) Add the following by weight: 20 parts of sulfonate monomer, 18 parts of soybean oil fatty acid, 10 parts of glycerol, 10 parts of pentaerythritol, 10 parts of phthalic anhydride, 10 parts of rosin, 10 parts of paint solvent oil No. 200 and xylene (by weight ratio 80 / 20), and 0.3 parts of additive (organosilicon defoamer) into the reactor. Stir and heat up to 155℃ for 1 hour, then heat up to 185℃ for 2 hours, and then heat up to 220℃ within 4 hours. During this process, take a sample to test its acid value. Stop heating when the acid value is lower than 12 mg KOH / g.

[0119] (2) Cool the reaction product of step (1) to 100°C, add paint solvent oil No. 200 and xylene (weight ratio 80 / 20) to dilute, stir evenly, filter, and obtain alkyd resin with high solid content and low VOC.

[0120] The preparation process of sulfonate monomers includes the following steps:

[0121] Take a clean 1000mL four-necked flask and add 1.08mol of neopentyl glycol and dibutyltin dilaurate according to the formula. Set up the experimental apparatus and turn on the cooling water, heating device, and stirring device. Heat the flask to 120℃ until the neopentyl glycol in the flask is in a molten state. Weigh 0.5mol of sodium isophthalic acid-5-sulfonate and add it through the feed port. At the same time, install a water separator to collect the H2O obtained from the reaction. Start heating at a rate of 20℃ / h. After the temperature reaches 195℃, keep it at this temperature and carefully observe the amount of water flowing out and the state in the flask. React for about 1 hour. After the reactants in the flask become transparent, take a sample to measure its acid value. When the acid value is less than 1.5mg KOH / g, cool it to room temperature to obtain the sulfonate type monomer. The amount of dibutyltin dilaurate added is 1.5% of the total mass of neopentyl glycol and sodium isophthalic acid-5-sulfonate.

[0122] Examples 1-3: A method for preparing high-solids, low-VOC alkyd resins, comprising the following steps:

[0123] (1) Add the following by weight: 17 parts of sulfonate monomer, 15 parts of soybean oil fatty acid, 7 parts of glycerol, 7 parts of pentaerythritol, 7 parts of phthalic anhydride, 7 parts of rosin, 9 parts of paint solvent oil No. 200 and xylene (weight ratio 80 / 20), and 0.2 parts of additive (organosilicon defoamer) into the reactor. Stir and heat to 150-155℃ and keep at that temperature for 1 hour. Then heat to 180-185℃ and keep at that temperature for 2 hours. Within 2 hours, heat to 210℃. During this process, take a sample to test its acid value. Stop heating when the acid value is lower than 12 mg KOH / g.

[0124] (2) Cool the reaction product of step (1) to 100°C, add paint solvent oil No. 200 and xylene (weight ratio 80 / 20) to dilute, stir evenly, filter, and obtain alkyd resin with high solid content and low VOC.

[0125] The preparation process of sulfonate monomers includes the following steps:

[0126] Take a clean 1000mL four-necked flask and add 1.1mol of neopentyl glycol and dibutyltin dilaurate according to the formula. Set up the experimental apparatus and turn on the cooling water, heating device, and stirring device. Heat the flask to 120℃ until the neopentyl glycol in the flask is in a molten state. Weigh 0.5mol of sodium isophthalic acid-5-sulfonate and add it through the feed port. At the same time, install a water separator to collect the H2O obtained from the reaction. Start heating at a rate of 20℃ / h. After the temperature reaches 200℃, keep it at this temperature and carefully observe the amount of water flowing out and the state in the flask. React for about 1 hour. After the reactants in the flask become transparent, take a sample to measure its acid value. When the acid value is less than 1.5mg KOH / g, cool it to room temperature to obtain the sulfonate type monomer. The amount of dibutyltin dilaurate added is 1.6% of the total mass of neopentyl glycol and sodium isophthalic acid-5-sulfonate.

[0127] Examples 1-4: A method for preparing high-solids, low-VOC alkyd resins, comprising the following steps:

[0128] (1) Add the following by weight: 16 parts of sulfonate monomer, 14 parts of soybean oil fatty acid, 6 parts of glycerol, 6 parts of pentaerythritol, 6 parts of phthalic anhydride, 6 parts of rosin, 8 parts of paint solvent oil No. 200 and xylene (by weight ratio 80 / 20), and 0.1 parts of additive (organosilicon defoamer) into the reactor. Stir and heat up to 150°C for 1 hour, then heat up to 180°C for 2 hours, and then heat up to 210°C within 2 hours. During this process, take a sample to test its acid value. Stop heating when the acid value is lower than 12 mg KOH / g.

[0129] (2) Cool the reaction product of step (1) to 100°C, add paint solvent oil No. 200 and xylene (weight ratio 80 / 20) to dilute, stir evenly, filter, and obtain alkyd resin with high solid content and low VOC.

[0130] The sulfonate monomers are from Example 1-1.

[0131] Examples 1-5: A method for preparing high-solids, low-VOC alkyd resins, comprising the following steps:

[0132] (1) Add the following by weight: 18 parts of sulfonate monomer, 16 parts of soybean oil fatty acid, 9 parts of glycerol, 9 parts of pentaerythritol, 9 parts of phthalic anhydride, 9 parts of rosin, 9 parts of paint solvent oil No. 200 and xylene (by weight ratio 80 / 20), and 0.3 parts of additive (organosilicon defoamer) into the reactor. Stir and heat up to 155°C for 1 hour, then heat up to 185°C for 2 hours, and then heat up to 220°C within 4 hours. During this process, take a sample to test its acid value. Stop heating when the acid value is lower than 12 mg KOH / g.

[0133] (2) Cool the reaction product of step (1) to 100°C, add paint solvent oil No. 200 and xylene (weight ratio 80 / 20) to dilute, stir evenly, filter, and obtain alkyd resin with high solid content and low VOC.

[0134] The sulfonate monomers are from Example 1-1.

[0135] Comparative Example 1-1

[0136] Replace the sulfonate type monomer with benzoic acid, and keep the other conditions the same as in Example 1-1;

[0137] Comparative Examples 1-2

[0138] No sulfonate monomers were added, and the weight of soybean oil fatty acids was changed to 28 parts, with the remaining conditions being the same as in Example 1-1.

[0139] Preparation Example 1-1

[0140] The preparation process of boron-zinc-cobalt drying agent includes the following steps:

[0141] (1) Preparation of precursor powder:

[0142] A mixture of 1 mmol Zn(NO3)2·6H2O, 2 mmol Co(NO3)2·6H2O, and 22 mmol NH4HCO3 was dissolved in 65 mL of deionized water. After stirring at room temperature for 30 min, the mixture was reacted at 5 MPa and 185 °C for 11 h, and then cooled to room temperature. The mixture was then centrifuged, washed three times with deionized water and ethanol, and dried in a vacuum oven at 70 °C.

[0143] The dried powder was heated to 650°C in a tube furnace at a heating rate of 2°C / min, and held at 650°C for 6 hours. After naturally cooling to room temperature, the precursor powder was obtained.

[0144] (2) Preparation of boron-zinc-cobalt drying agent

[0145] 1 g of the calcined precursor powder was placed in 65 mL of deionized water and sonicated for 30 min to ensure uniform dispersion. Then, 0.6 g of boric acid was added and dissolved in the above solution. The mixture was stirred for 30 min and reacted at 5 MPa and 185 °C for 11 h. After cooling to room temperature, the obtained material was centrifuged, washed three times with water and ethanol, and dried under vacuum at 70 °C overnight to obtain the boron-zinc-cobalt drying agent.

[0146] Preparation Examples 1-2

[0147] The preparation process of boron-zinc-cobalt drying agent includes the following steps:

[0148] (1) Preparation of precursor powder:

[0149] A mixture of 1 mmol Zn(NO3)2·6H2O, 2 mmol Co(NO3)2·6H2O, and 20 mmol NH4HCO3 was dissolved in 60 mL of deionized water. After stirring at room temperature for 30 min, the mixture was reacted at 5 MPa and 180 °C for 10 h, and then cooled to room temperature. The mixture was then centrifuged, washed three times with deionized water and ethanol, and dried in a vacuum oven at 70 °C.

[0150] The dried powder was heated to 600°C in a tube furnace at a heating rate of 2°C / min and held at 600°C for 5 hours. After naturally cooling to room temperature, the precursor powder was obtained.

[0151] (2) Preparation of boron-zinc-cobalt drying agent

[0152] 1 g of the calcined precursor powder was placed in 60 mL of deionized water and sonicated for 30 min to ensure uniform dispersion. Then, 0.6 g of boric acid was added and dissolved in the above solution. The mixture was stirred for 30 min and reacted at 5 MPa and 180 °C for 10 h. After cooling to room temperature, the obtained material was centrifuged, washed three times with water and ethanol, and vacuum dried overnight at 70 °C to obtain the boron-zinc-cobalt drying agent.

[0153] Preparation Examples 1-3

[0154] The preparation process of boron-zinc-cobalt drying agent includes the following steps:

[0155] (1) Preparation of precursor powder:

[0156] A mixture of 1 mmol Zn(NO3)2·6H2O, 2 mmol Co(NO3)2·6H2O, and 25 mmol NH4HCO3 was dissolved in 70 mL of deionized water. After stirring at room temperature for 30 min, the mixture was reacted at 5 MPa and 190 °C for 12 h, and then cooled to room temperature. The mixture was then centrifuged, washed three times with deionized water and ethanol, and dried in a vacuum oven at 70 °C.

[0157] The dried powder was heated to 700°C in a tube furnace at a heating rate of 2°C / min, and held at 700°C for 7 hours. After naturally cooling to room temperature, the precursor powder was obtained.

[0158] (2) Preparation of boron-zinc-cobalt drying agent

[0159] 1 g of the calcined precursor powder was placed in 70 mL of deionized water and sonicated for 30 min to ensure uniform dispersion. Then, 0.6 g of boric acid was added and dissolved in the above solution. The mixture was stirred for 30 min and reacted at 5 MPa and 190 °C for 12 h. After cooling to room temperature, the obtained material was centrifuged, washed three times with water and ethanol, and vacuum dried overnight at 70 °C to obtain the boron-zinc-cobalt drying agent.

[0160] Example 2-1: Alkyd coating, comprising the following components in parts by weight:

[0161] 30 parts alkyd resin, 10 parts hydrogenated rosin glycerol ester, 10 parts pigment (titanium dioxide), 30 parts filler (barium sulfate), 10 parts solvent (including paint solvent oil No. 200 and xylene (weight ratio 80 / 20)), and 0.8 parts boron zinc cobalt drier;

[0162] The preparation method of the above alkyd coating includes the following steps:

[0163] (1) Add high solids content low VOC alkyd resin, tackifying resin, and part of the solvent (accounting for 50% of the total weight of solvent) to the mixing tank, stir evenly to form a mixture.

[0164] (2) Add pigments and fillers to the mixture in step (1), turn on the high-speed disperser (1500 rpm), so that the pigments and fillers are evenly dispersed in the system for 30 minutes to obtain the slurry.

[0165] (3) Grind the above slurry through a sand mill (the grinding medium is zirconia beads), and check the fineness by a scraper fineness gauge to ensure that the fineness reaches 20-25 μm.

[0166] (4) Add boron zinc cobalt drying agent while stirring at low speed (500 rpm) and stir to disperse it so that it is fully mixed.

[0167] (5) Add the remaining solvent (accounting for 50% of the total weight of the solvent), stir evenly, and obtain a low-cost alkyd coating.

[0168] The alkyd resin was from Example 1-1, and the boron-zinc-cobalt drying agent was from Preparation Example 1-1.

[0169] Example 2-2: Alkyd coating, comprising the following components in parts by weight:

[0170] 40 parts alkyd resin, 15 parts hydrogenated rosin glycerol ester, 15 parts pigment (titanium dioxide), 35 parts filler (barium sulfate), 15 parts solvent (including paint solvent oil No. 200 and xylene (weight ratio 80 / 20)), and 1 part boron zinc cobalt drier.

[0171] The preparation method of the above alkyd coating includes the following steps:

[0172] (1) Add high solids content low VOC alkyd resin, tackifying resin, and part of the solvent (accounting for 50% of the total weight of solvent) to the mixing tank, stir evenly to form a mixture.

[0173] (2) Add pigments and fillers to the mixture in step (1), turn on the high-speed disperser (2000 rpm), so that the pigments and fillers are evenly dispersed in the system for 30 minutes to obtain the slurry.

[0174] (3) Grind the above slurry through a sand mill (the grinding medium is zirconia beads), and check the fineness by a scraper fineness gauge to ensure that the fineness reaches 20-25 μm.

[0175] (4) Add boron zinc cobalt drying agent while stirring at low speed (500 rpm) and stir to disperse it so that it is fully mixed.

[0176] (5) Add the remaining solvent (accounting for 50% of the total weight of the solvent), stir evenly, and obtain a low-cost alkyd coating.

[0177] The alkyd resin was from Examples 1-2, and the boron-zinc-cobalt drying agent was from Preparation Examples 1-2.

[0178] Examples 2-3: Alkyd coatings, comprising the following components in parts by weight:

[0179] 35 parts alkyd resin, 15 parts hydrogenated rosin glycerol ester, 12 parts pigment (titanium dioxide), 33 parts filler (barium sulfate), 13 parts solvent (including paint solvent oil No. 200 and xylene (weight ratio 80 / 20)), and 0.9 parts boron zinc cobalt drier;

[0180] The preparation method of the above alkyd coating includes the following steps:

[0181] (1) Add high solids content low VOC alkyd resin, tackifying resin, and part of the solvent (accounting for 50% of the total weight of solvent) to the mixing tank, stir evenly to form a mixture.

[0182] (2) Add pigments and fillers to the mixture in step (1), turn on the high-speed disperser (1800 rpm), so that the pigments and fillers are evenly dispersed in the system for 30 minutes to obtain the slurry.

[0183] (3) Grind the above slurry through a sand mill (the grinding medium is zirconia beads), and check the fineness by a scraper fineness gauge to ensure that the fineness reaches 20-25 μm.

[0184] (4) Add boron zinc cobalt drying agent while stirring at low speed (500 rpm) and stir to disperse it so that it is fully mixed.

[0185] (5) Add the remaining solvent (accounting for 50% of the total weight of the solvent), stir evenly, and obtain a low-cost alkyd coating.

[0186] The alkyd resin was from Examples 1-3, and the boron-zinc-cobalt drying agent was from Preparation Examples 1-3.

[0187] Examples 2-4: Alkyd coatings, comprising the following components in parts by weight:

[0188] 32 parts alkyd resin, 11 parts hydrogenated rosin glycerol ester, 11 parts pigment (titanium dioxide), 32 parts filler (barium sulfate), 11 parts solvent (including paint solvent oil No. 200 and xylene (weight ratio 80 / 20)), and 0.85 parts boron zinc cobalt drier;

[0189] The preparation method of the above alkyd coating includes the following steps:

[0190] (1) Add high solids content low VOC alkyd resin, tackifying resin, and part of the solvent (accounting for 50% of the total weight of solvent) to the mixing tank, stir evenly to form a mixture.

[0191] (2) Add pigments and fillers to the mixture in step (1), turn on the high-speed disperser (1600 rpm), so that the pigments and fillers are evenly dispersed in the system for 30 minutes to obtain the slurry.

[0192] (3) Grind the above slurry through a sand mill (the grinding medium is zirconia beads), and check the fineness by a scraper fineness gauge to ensure that the fineness reaches 20-25 μm.

[0193] (4) Add boron zinc cobalt drying agent while stirring at low speed (500 rpm) and stir to disperse it so that it is fully mixed.

[0194] (5) Add the remaining solvent (accounting for 50% of the total weight of the solvent), stir evenly, and obtain a low-cost alkyd coating.

[0195] The alkyd resin was from Examples 1-4, and the boron-zinc-cobalt drying agent was from Preparation Example 1-1.

[0196] Examples 2-5: Alkyd coatings, comprising the following components in parts by weight:

[0197] 38 parts alkyd resin, 14 parts hydrogenated rosin glycerol ester, 14 parts pigment (titanium dioxide), 34 parts filler (barium sulfate), 14 parts solvent (including paint solvent oil No. 200 and xylene (weight ratio 80 / 20)), and 0.95 parts boron zinc cobalt drier;

[0198] The preparation method of the above alkyd coating includes the following steps:

[0199] (1) Add high solids content low VOC alkyd resin, tackifying resin, and part of the solvent (accounting for 50% of the total weight of solvent) to the mixing tank, stir evenly to form a mixture.

[0200] (2) Add pigments and fillers to the mixture in step (1), turn on the high-speed disperser (1900 rpm), and disperse the pigments and fillers evenly in the system for 30 minutes to obtain the slurry.

[0201] (3) Grind the above slurry through a sand mill (the grinding medium is zirconia beads), and check the fineness by a scraper fineness gauge to ensure that the fineness reaches 20-25 μm.

[0202] (4) Add boron zinc cobalt drying agent while stirring at low speed (500 rpm) and stir to disperse it so that it is fully mixed.

[0203] (5) Add the remaining solvent (accounting for 50% of the total weight of the solvent), stir evenly, and obtain a low-cost alkyd coating.

[0204] The alkyd resin was from Examples 1-5, and the boron-zinc-cobalt drying agent was from Preparation Example 1-1.

[0205] Comparative Example 2-1

[0206] The alkyd resin used was from Comparative Example 1-1, and the rest was the same as in Example 2-1.

[0207] Comparative Example 2-2

[0208] The alkyd resin used was from Comparative Examples 1-2, and the rest was the same as in Examples 2-1.

[0209] Comparative Examples 2-3

[0210] The boron-zinc-cobalt drying agent was not added; instead, cobalt isooctanoate was added as the drying agent. The rest of the process was the same as in Example 2-1.

[0211] Comparative Examples 2-4

[0212] Alkyd resin is not added; otherwise, it is the same as in Example 2-1.

[0213] Comparative Examples 2-5

[0214] No boron-zinc-cobalt drying agent was added; otherwise, it was the same as in Example 2-1.

[0215] Comparative Examples 2-6

[0216] No boron-zinc-cobalt drying agent or alkyd resin was added; otherwise, it was the same as in Example 2-1.

[0217] Examples 1-1 to 1-5 and Comparative Examples 1-1 to 1-2 were tested for solid content and VOC, and the results are summarized in Table 1.

[0218] Examples 2-1 to 2-5, and Comparative Examples 2-1 to 2-6, were used to test gloss, hardness, adhesion, salt spray resistance, quick-drying time, and impact resistance. The results are summarized in Table 2.

[0219] Table 1

[0220]

[0221] As shown in Table 1, Examples 1-1 to 1-5 all used optimized components such as sulfonate monomers (15-20 parts by weight), soybean oil fatty acids, glycerol, and pentaerythritol, and adopted a stepwise heating method (e.g., Example 1-1: heating to 150℃ and holding for 1 hour, then heating to 180℃ and holding for 2 hours, and finally heating to 210℃ within 2 hours). The results showed high solids content (80.1-83.4%) and low VOC content (37.3-41.2 g / L), indicating that the introduction of sulfonate monomers effectively improved the dispersibility of the resin, reduced the use of organic solvents, and met environmental protection requirements.

[0222] Comparative Example 1-1: Replacing the sulfonate monomer with benzoic acid (with other conditions the same as in Example 1-1) resulted in a decrease in solid content (75.5%) and an increase in VOC (80.9 g / L), indicating that benzoic acid cannot provide good dispersibility and has high VOC emissions.

[0223] Comparative Examples 1-2: Without the addition of sulfonate monomers, and with the soybean oil fatty acid weight parts changed to 28 parts (other conditions were the same as in Example 1-1), the solid content was further reduced (70.3%), and the VOC was significantly increased (100.5 g / L), indicating that the addition of sulfonate monomers helps to achieve high solid content and low VOC.

[0224] Table 2

[0225]

[0226] Table 2 shows that Examples 2-1 to 2-5 used the alkyd resins from Examples 1-1 to 1-5, with the addition of boron-zinc-cobalt driers (as in Preparation Example 1-1), tackifying resins (hydrogenated rosin glycerol ester), pigments (titanium dioxide), and fillers (barium sulfate). The results showed that the coatings exhibited excellent gloss (85.2-88.7%), high hardness (2H-3H), excellent adhesion (0-1 grade), salt spray resistance (150-164.8 h), fast surface drying time (0.5-0.6 h), fast hard drying time (3.5-4.2 h), and impact resistance (45.4-50.1 kg·cm). This indicates that the optimized alkyd resin combined with boron-zinc-cobalt driers can significantly improve the overall performance of the coatings.

[0227] Comparative Examples 2-1 and 2-2: The alkyd resins used in Comparative Examples 1-1 and 1-2 (with poor performance) resulted in coatings with low gloss (65.3-70.5%), poor hardness (Grade B), weak adhesion (Grade 3-4), poor salt spray resistance (60.5-80 h), long surface drying time (1.5-2.0 h), long hard drying time (8.0-10.0 h), and low impact resistance (20.7-25.1 kg·cm).

[0228] Comparative Examples 2-3: Without adding boron-zinc-cobalt drying agent, cobalt isooctanoate was used instead (other conditions were the same as in Example 2-1). Although the performance was better than other comparative examples, it was still lower than that of the example (gloss 75.1%, hardness HB, adhesion grade 2, salt spray resistance 100 h, surface drying time 1.0 h, and complete drying time 6.0 h). This shows that boron-zinc-cobalt drying agent is more effective in accelerating drying (especially surface drying) and improving corrosion resistance.

[0229] Comparative Examples 2-4 and 2-6: No alkyd resin was added (other conditions were similar to Example 2-1), and the performance was extremely poor (gloss 45.5-50.8%, hardness 4B-5B, adhesion grade 5, salt spray resistance 20-30 h, surface drying time 2.5-3.0 h, hard drying time 12.0-15.0 h, impact resistance 5.7-10.9 kg·cm).

[0230] Comparative Examples 2-5: Without the addition of boron-zinc-cobalt drying agent (other conditions are the same as in Example 2-1), the performance is poor (gloss 72.6%, hardness HB, adhesion grade 3, salt spray resistance 90.5h, surface drying time 1.2h, and complete drying time 7.0h).

[0231] The above description is merely a preferred embodiment of this application and is not intended to limit this application. Any modifications, equivalent substitutions, and improvements made within the principles of this application should be included within the protection scope of this application.

Claims

1. An alkyd coating, characterized in that, The components include the following parts by weight: 30-40 parts alkyd resin, 10-15 parts tackifying resin, 10-15 parts pigment, 30-35 parts filler, 10-15 parts solvent B, and 0.8-1 part boron-zinc-cobalt drying agent; The alkyd resin comprises the following components in parts by weight: Sulfonate type monomer 15-20 parts, soybean oil fatty acid 13-18 parts, glycerol 5-10 parts, pentaerythritol 5-10 parts, phthalic anhydride 5-10 parts, rosin 5-10 parts, solvent A 8-10 parts, auxiliaries 0.1-0.3 parts; The sulfonate type monomer is prepared by reacting sodium isophthalic acid-5-sulfonate and neopentyl glycol at a molar ratio of 1:2.1 to 2.2 at 190°C to 200°C. The preparation process of the boron-zinc-cobalt drying agent includes: dissolving Zn(NO3)2·6H2O, Co(NO3)2·6H2O, and NH4HCO3 in water, and then carrying out a first hydrothermal reaction to obtain a precursor; calcining the precursor, followed by boric acid treatment and a second hydrothermal reaction to obtain the boron-zinc-cobalt drying agent.

2. The alkyd coating according to claim 1, characterized in that, The alkyd resin comprises the following components in parts by weight: Sulfonate type monomer 16-18 parts, soybean oil fatty acid 14-16 parts, glycerol 6-9 parts, pentaerythritol 6-9 parts, phthalic anhydride 6-9 parts, rosin 6-9 parts, solvent A 8-10 parts, and auxiliary agent 0.1-0.3 parts.

3. The alkyd coating according to claim 1, characterized in that, The additives include at least one of dispersants and defoamers; And / or, the solvent A comprises paint solvent oil No. 200 and xylene, wherein the weight ratio of paint solvent oil No. 200 to xylene is 80:

20.

4. The alkyd coating according to claim 1, characterized in that, The preparation process of the sulfonate monomer includes the following steps: Neopentyl glycol was fed in a specific molar ratio, a catalyst was added, and the neopentyl glycol was heated to melt. Sodium isophthalic acid-5-sulfonate was then added, and the reaction was carried out at 190℃~200℃. When the acid value of the reaction system was ≤1.5mg KOH / g, the reaction reached its endpoint, and the reaction was stopped to obtain the sulfonate type monomer.

5. The alkyd coating according to claim 4, characterized in that, The catalyst is dibutyltin dilaurate, and the amount of dibutyltin dilaurate added is 1.4% to 1.6% of the total mass of neopentyl glycol and sodium isophthalate-5-sulfonate.

6. The alkyd coating according to claim 1, characterized in that, The preparation method of the alkyd resin includes the following steps: (1) Add sulfonate type monomer, soybean oil fatty acid, glycerol, pentaerythritol, phthalic anhydride, rosin and additives into the reactor according to the weight parts, stir and heat up to 150-155℃ and keep at 1h, heat up to 180-185℃ and keep at 2h, and heat up to 210-220℃ in 2-4h; during this process, take a sample to test its acid value, and stop heating when the acid value is lower than 12mg KOH / g; (2) Cool the reaction product of step (1) to 100°C, add solvent A for dilution, stir evenly, and filter to obtain alkyd resin with high solid content and low VOC.

7. The alkyd coating according to claim 1, characterized in that, The preparation process of boron-zinc-cobalt drying agent satisfies at least one of the following conditions: (1) The molar ratio of Zn(NO3)2·6H2O, Co(NO3)2·6H2O, and NH4HCO3 is 1:2:(20-25); (2) The conditions for the first hydrothermal reaction are to react at 180℃~190℃ for 10~12h; (3) The calcination treatment conditions are calcination at 600℃~700℃ for 5~7h, and then cooling to room temperature; (4) The conditions for boric acid treatment are as follows: disperse the calcined precursor in water, then add boric acid, and stir for 30 minutes after the boric acid is completely dissolved; the mass ratio of the calcined precursor to boric acid is 1:0.

6. (5) The conditions for the second hydrothermal reaction are: react at 180℃~190℃ for 10~12h.

8. The alkyd coating according to claim 1, characterized in that, The tackifying resin is hydrogenated rosin glycerol ester.

9. The alkyd coating according to claim 1, characterized in that, The filler includes at least one of barium sulfate, calcium carbonate, zinc phosphate, and aluminum tripolyphosphate.

Images