Preparation method of environment-friendly high-performance water-based alkyd resin

Abstract

The present application relates to the field of resin, in particular to a kind of preparation method of environment-friendly high-performance water-based alkyd resin.The water-based alkyd resin includes the following ingredients according to weight fraction: 30-35 parts of bio-based vegetable oil, 15-22 parts of polyol, 18-26 parts of polybasic acid, 8-12 parts of polyether alcohol modifier, 0.02-0.05 parts of catalyst, 0.1-0.3 parts of antioxidant, 8-12 parts of cosolvent, 0.5-1.5 parts of neutralizing agent and 40-50 parts of deionized water.The environment-friendly high-performance water-based alkyd resin provided by the present application realizes the synergistic unity of environmental protection and comprehensive high performance by regulating raw material composition and ratio and optimizing preparation process parameters, effectively solves the problems of fast drying and high hardness contradiction, poor water resistance, poor storage stability and other problems commonly existing in existing water-based alkyd resin.

Description

Technical Field

[0001] This invention relates to the field of resins, and more specifically to a method for preparing an environmentally friendly, high-performance waterborne alkyd resin. Background Technology

[0002] Alkyd resins, as one of the oldest and most widely used synthetic resins in the coatings industry, are highly favored due to their readily available raw materials, high cost-effectiveness, and excellent overall performance. However, traditional solvent-based alkyd resins release large amounts of volatile organic compounds (VOCs) during production and application, posing a threat to the environment and human health. With increasingly stringent global environmental regulations and the advancement of "dual carbon" goals, the transformation of the coatings industry towards low-VOC and environmentally friendly products has become an inevitable trend. Against this backdrop, waterborne alkyd resins have emerged. Using water as the main dispersion medium, they can significantly reduce the use of organic solvents, reducing organic solvent usage by approximately 400 kg per ton of coating. This results in a substantial reduction in VOC content and offers significant advantages such as safer production and application processes and easier equipment cleaning.

[0003] Despite the significant environmental advantages of waterborne alkyd resins, they still have many problems in practical applications and performance: First, the drying speed is slow, the initial hardness is too low, and the latent heat of vaporization of water is much higher than that of organic solvents, which leads to a significant extension of the surface drying and hard drying time of the paint film, affecting the construction efficiency; Second, the water resistance and storage stability are poor, which is the most critical defect of waterborne alkyd resins. The ester bonds in the resin backbone are prone to hydrolysis in weakly alkaline or aqueous environments, leading to the breakage of the resin molecular chain.

[0004] Therefore, developing a method that produces green raw materials and simultaneously imparts comprehensive high performance to waterborne alkyd resins, such as fast drying, high hardness, excellent water resistance, and storage stability, is of great practical significance and commercial value for promoting the application of waterborne alkyd resins in high-end industrial protection, wood coatings, and other fields. Summary of the Invention

[0005] In view of the problems existing in the prior art, the purpose of this invention is to provide a method for preparing environmentally friendly, high-performance waterborne alkyd resin.

[0006] The objective of this invention is achieved through the following technical solution: In a first aspect, the present invention provides an environmentally friendly, high-performance waterborne alkyd resin, comprising the following components by weight: 30-35 parts bio-based vegetable oil, 15-22 parts polyol, 18-26 parts polyacid, 8-12 parts polyether alcohol modifier, 0.02-0.05 parts catalyst, 0.1-0.3 parts antioxidant, 8-12 parts cosolvent, 0.5-1.5 parts neutralizer and 40-50 parts deionized water.

[0007] Preferably, the bio-based vegetable oil is one or more of linseed oil, palm oil, tung oil, castor oil, and peanut oil.

[0008] Preferably, the polyol is one or more of 4,4'-dihydroxydiphenyl ether, pentaerythritol, trimethylolpropane, neopentyl glycol, diethylene glycol, and trimethylolethane.

[0009] More preferably, the polyol is a mixture of pentaerythritol, 4,4'-dihydroxydiphenyl ether and trimethylolpropane in a weight ratio of 8-12:5-8:4-6.

[0010] Preferably, the polybasic acid is a mixture of isophthalic acid, bis(4-carboxyphenyl)phenylphosphine oxide, adipic acid, and trimellitic anhydride; wherein the weight ratio of isophthalic acid, bis(4-carboxyphenyl)phenylphosphine oxide, adipic acid, and trimellitic anhydride is 8-12:3-5:4-6:2-4.

[0011] Preferably, the polyether alcohol modifier is one or more of polyethylene glycol monomethyl ether, polyethylene glycol monooctyl ether, polyethylene glycol monomethyl ether, glyceryl diglycidyl ether, polypropylene glycol oleyl ether, and polyoxyethyl polyoxypropyl glyceryl ether.

[0012] Preferably, the catalyst is an organotin catalyst, specifically one or more of dibutyltin dilaurate (DBTDL), dioctyltin dilaurate (DOTDL), and dibutyltin dioctanoate (DBTO).

[0013] Preferably, the antioxidant is a hindered phenolic antioxidant, specifically one or more of antioxidant 1010, antioxidant 1076, antioxidant 1098, and antioxidant 1135.

[0014] Preferably, the co-solvent is one or more of propylene glycol methyl ether, dipropylene glycol methyl ether, ethylene glycol methyl ether, and dipropylene glycol butyl ether.

[0015] Preferably, the neutralizing agent is ammonia or dimethylethanolamine.

[0016] Secondly, this invention proposes a method for preparing an environmentally friendly, high-performance waterborne alkyd resin, comprising the following steps: Step 1: Add vegetable oil, polyol, polyacid and catalyst to the four-necked flask in sequence; Step 2: Under nitrogen protection, gradually increase the temperature from room temperature to 200-210℃. After monitoring the acid value to reach the set standard, stop increasing the temperature and cool down to 160-170℃. Step 3: Slowly add the polyether alcohol modifier to the flask and keep it warm while stirring for 1-3 hours; Step 4: Cool down to 80-90℃, add neutralizer, antioxidant and solubilizer, stir well, gradually add deionized water dropwise, after the addition is complete, keep warm to emulsify, and then cool down to below 40℃; Step 5: Filter the emulsion to remove impurities and obtain water-based alkyd resin.

[0017] Preferably, in step 1, the vegetable oil, polyol, polyacid, and catalyst need to be dried before being added to the flask.

[0018] Preferably, in step 2, the heating rate is 5℃ / min; the heating process includes: first heating from room temperature to 120℃, holding for 1 hour, then heating to 160℃, holding for 2 hours, then heating to 190℃, holding for 3 hours, and continuing to heat to 200-210℃.

[0019] Preferably, in step 2, after heating to 200-210℃, samples are taken every half hour to test the acid value until the acid value reaches 35-45 mgKOH / g, at which point heating is stopped.

[0020] Preferably, in step 3, the stirring rate is increased to 500 r / min.

[0021] Preferably, in step 4, after adding the neutralizing agent, the mixture is stirred for 30 minutes at a stirring speed of 300 r / min.

[0022] Preferably, in step 4, deionized water is added dropwise over 1 hour, and the stirring rate is increased to 800 r / min during the addition process.

[0023] Preferably, in step 5, the emulsion is filtered using a 200-mesh nylon filter.

[0024] The beneficial effects of this invention are as follows: 1. The environmentally friendly high-performance waterborne alkyd resin provided by this invention achieves a synergistic unity of environmental protection and comprehensive high performance by adjusting the composition and ratio of raw materials and optimizing the preparation process parameters. It effectively solves the problems of contradiction between fast drying and high hardness, insufficient water resistance, and poor storage stability that are common in existing waterborne alkyd resins.

[0025] 2. In the preparation of alkyd resin in this invention, renewable bio-based plant oil is used as the main raw material. The high unsaturation of its fatty acid chains provides abundant oxidative crosslinking sites for the paint film. Furthermore, the synergistic arrangement of three polyol systems, combined with a stepwise heating esterification process, jointly constructs a molecular framework with high crosslinking density, significantly shortening the surface drying and hard drying time of the paint film and meeting the requirements for high-efficiency construction. In addition, the introduction of bis(4-carboxyphenyl)phenylphosphine oxide also brings potential flame-retardant properties to the resin. Its phosphorus content can promote char formation during combustion, interrupting the combustion process and expanding the application prospects of the resin in special fields such as fire-retardant coatings.

[0026] 3. In the formulation of this invention, the aromatic ring structure of 4,4'-dihydroxydiphenyl ether in the polyol and the conjugated system of bis(4-carboxyphenyl)phenylphosphine oxide in the polyacid form a rigid support. The polyhydroxy structure of pentaerythritol increases the crosslinking density, and adipic acid provides flexible segments, achieving a balance between high hardness and non-brittleness in the mechanical properties of the paint film. Specifically, 4,4'-dihydroxydiphenyl ether and bis(4-carboxyphenyl)phenylphosphine oxide exhibit a significant synergistic effect in the resin system. The aromatic ring structures in both molecules jointly increase the packing density of the molecular chains, reduce the exposure of hydrophilic groups in the paint film, lower the penetration rate of water or acid / alkali media, and improve the water resistance and chemical corrosion resistance of the paint film.

[0027] 4. Through the optimization of raw material pretreatment and emulsification process, the present invention makes the resin emulsion particle size uniform and the dispersion stability excellent. The resulting product can be stored stably for more than 12 months under sealed storage conditions at room temperature without layering, precipitation or gelation. The emulsion viscosity change rate is small, which meets the use requirements of long-distance transportation and long-term storage. Detailed Implementation

[0028] The technical solution of the present invention is illustrated below through specific examples. It should be understood that the one or more method steps mentioned in the present invention do not preclude the existence of other method steps before or after the combined steps, or the insertion of other method steps between these explicitly mentioned steps; it should also be understood that these embodiments are for illustrative purposes only and are not intended to limit the scope of the present invention. Furthermore, unless otherwise stated, the numbering of each method step is merely a convenient tool for identifying each method step, and not for limiting the order of the method steps or defining the scope of the present invention. Changes or adjustments to their relative relationships, without substantially altering the technical content, should also be considered within the scope of the present invention.

[0029] To better understand the above technical solutions, exemplary embodiments of the present invention are described in more detail below. While exemplary embodiments of the present invention are shown, it should be understood that the present invention can be implemented in various forms and should not be limited to the embodiments set forth herein. Rather, these embodiments are provided to enable a more thorough understanding of the present invention and to fully convey the scope of the invention to those skilled in the art.

[0030] The vegetable oils used in the embodiments or comparative examples of this invention are all industrial grade vegetable oils.

[0031] The present invention will be further described below with reference to the following embodiments.

[0032] Example 1 An environmentally friendly, high-performance waterborne alkyd resin, comprising the following components by weight:

[0033] The preparation method of the above-mentioned environmentally friendly high-performance waterborne alkyd resin includes the following steps: Step 1: Add the dried vegetable oil, polyol, polyacid and catalyst sequentially to a four-necked flask equipped with a stirrer, thermometer, reflux condenser and water separator. Step 2: Under nitrogen protection, gradually increase the temperature at a rate of 5℃ / min. First, raise the temperature from room temperature to 120℃, hold for 1 hour, then raise it to 160℃ and hold for 2 hours. Next, raise the temperature to 190℃ and hold for 3 hours, then continue to raise the temperature to 210℃. Take a sample every half hour to test the acid value until the acid value reaches 40mgKOH / g, then stop heating and cool down to 170℃. Step 3: Slowly add the polyether alcohol modifier to the flask, increase the stirring speed to 500 r / min, and keep it at 170℃ for 2 hours; Step 4: Cool down to 85℃, add neutralizing agent, antioxidant and cosolvent, stir for 30 min at a stirring rate of 300 r / min, maintain 85℃, and gradually add deionized water dropwise over 1 h, increasing the stirring rate to 800 r / min during the dropwise addition to form a stable oil-in-water emulsion; after the dropwise addition is complete, maintain the temperature at 85℃ for 1 h for emulsification, and then cool down to below 40℃. Step 5: Filter the emulsion using a 200-mesh nylon filter to remove impurities and obtain water-based alkyd resin.

[0034] Example 2 An environmentally friendly, high-performance waterborne alkyd resin, comprising the following components by weight:

[0035] The preparation method of the above-mentioned environmentally friendly high-performance waterborne alkyd resin includes the following steps: Step 1: Add the dried vegetable oil, polyol, polyacid and catalyst sequentially to a four-necked flask equipped with a stirrer, thermometer, reflux condenser and water separator. Step 2: Under nitrogen protection, gradually increase the temperature at a rate of 5℃ / min. First, raise the temperature from room temperature to 120℃, hold for 1 hour, then raise it to 160℃ and hold for 2 hours. Next, raise the temperature to 190℃ and hold for 3 hours, then continue to raise the temperature to 200℃. Take a sample every half hour to test the acid value until the acid value reaches 35mgKOH / g, then stop heating and cool down to 160℃. Step 3: Slowly add the polyether alcohol modifier to the flask, increase the stirring speed to 500 r / min, and keep it at 160℃ for 2 h; Step 4: Cool down to 80℃, add neutralizing agent, antioxidant and cosolvent, stir for 20 min at a stirring rate of 200 r / min, maintain 80℃, and gradually add deionized water dropwise over 1 h, increasing the stirring rate to 800 r / min during the dropwise addition to form a stable oil-in-water emulsion; after the dropwise addition is complete, keep it at 85℃ for 1 h for emulsification, and then cool down to below 40℃. Step 5: Filter the emulsion using a 200-mesh nylon filter to remove impurities and obtain water-based alkyd resin.

[0036] Example 3 An environmentally friendly, high-performance waterborne alkyd resin, comprising the following components by weight:

[0037] The preparation method of the above-mentioned environmentally friendly high-performance waterborne alkyd resin includes the following steps: Step 1: Add the dried vegetable oil, polyol, polyacid and catalyst sequentially to a four-necked flask equipped with a stirrer, thermometer, reflux condenser and water separator. Step 2: Under nitrogen protection, gradually increase the temperature at a rate of 5℃ / min. First, raise the temperature from room temperature to 120℃, hold for 1 hour, then raise it to 160℃ and hold for 2 hours. Next, raise the temperature to 190℃ and hold for 3 hours, then continue to raise the temperature to 210℃. Take a sample every half hour to test the acid value until the acid value reaches 35mgKOH / g, then stop heating and cool down to 170℃. Step 3: Slowly add the polyether alcohol modifier to the flask, increase the stirring speed to 500 r / min, and keep it at 170℃ for 2 hours; Step 4: Cool down to 85℃, add neutralizing agent, antioxidant and cosolvent, stir for 20 min at a stirring rate of 200 r / min, maintain 85℃, and gradually add deionized water dropwise over 1 h, increasing the stirring rate to 800 r / min during the dropwise addition to form a stable oil-in-water emulsion; after the dropwise addition is complete, maintain emulsification at 85℃ for 1 h, and then cool down to below 40℃. Step 5: Filter the emulsion using a 200-mesh nylon filter to remove impurities and obtain water-based alkyd resin.

[0038] Example 4 An environmentally friendly, high-performance waterborne alkyd resin, comprising the following components by weight:

[0039] The preparation method of the above-mentioned environmentally friendly high-performance waterborne alkyd resin includes the following steps: Step 1: Add the dried vegetable oil, polyol, polyacid and catalyst sequentially to a four-necked flask equipped with a stirrer, thermometer, reflux condenser and water separator. Step 2: Under nitrogen protection, gradually increase the temperature at a rate of 5℃ / min. First, raise the temperature from room temperature to 120℃, hold for 1 hour, then raise it to 160℃ and hold for 2 hours. Next, raise the temperature to 190℃ and hold for 3 hours, then continue to raise the temperature to 210℃. Take a sample every half hour to test the acid value until the acid value reaches 45mgKOH / g, then stop raising the temperature and cool down to 170℃. Step 3: Slowly add the polyether alcohol modifier to the flask, increase the stirring speed to 500 r / min, and keep it at 170℃ for 2 hours; Step 4: Cool down to 85℃, add neutralizing agent, antioxidant and cosolvent, stir for 30 min at a stirring rate of 300 r / min, maintain 85℃, and gradually add deionized water dropwise over 1 h, increasing the stirring rate to 800 r / min during the dropwise addition to form a stable oil-in-water emulsion; after the dropwise addition is complete, maintain the temperature at 85℃ for 1 h for emulsification, and then cool down to below 40℃. Step 5: Filter the emulsion using a 200-mesh nylon filter to remove impurities and obtain water-based alkyd resin.

[0040] Example 5 An environmentally friendly, high-performance waterborne alkyd resin, comprising the following components by weight:

[0041] The preparation method of the above-mentioned environmentally friendly high-performance waterborne alkyd resin includes the following steps: Step 1: Add the dried vegetable oil, polyol, polyacid and catalyst sequentially to a four-necked flask equipped with a stirrer, thermometer, reflux condenser and water separator. Step 2: Under nitrogen protection, gradually increase the temperature at a rate of 5℃ / min. First, raise the temperature from room temperature to 120℃, hold for 1 hour, then raise it to 160℃ and hold for 2 hours. Next, raise the temperature to 190℃ and hold for 3 hours, then continue to raise the temperature to 210℃. Take a sample every half hour to test the acid value until the acid value reaches 40mgKOH / g, then stop raising the temperature and cool down to 160℃. Step 3: Slowly add the polyether alcohol modifier to the flask, increase the stirring speed to 500 r / min, and keep it at 160℃ for 2 h; Step 4: Cool to 90℃, add neutralizing agent, antioxidant and cosolvent, stir for 20-30 minutes at a stirring rate of 300 r / min, maintain 90℃, and gradually add deionized water dropwise over 1 hour, increasing the stirring rate to 800 r / min during the dropwise addition to form a stable oil-in-water emulsion; after the dropwise addition is complete, keep it at 85℃ for 1 hour to emulsify, and then cool to below 40℃. Step 5: Filter the emulsion using a 200-mesh nylon filter to remove impurities and obtain water-based alkyd resin.

[0042] Comparative Example 1 A water-based alkyd resin, without the addition of bis(4-carboxyphenyl)phenylphosphine oxide, that is, except that the polybasic acid is replaced with "isophthalic acid: adipic acid: TMA = 14:5:3 (weight ratio)", the other raw materials and their amounts are the same as in Example 1. The preparation steps are the same as in Example 1.

[0043] Comparative Example 2 A water-based alkyd resin, without the addition of 4,4'-dihydroxydiphenyl ether, that is, except that the polyol is replaced with "pentaerythritol:trimethylolpropane = 15:6 (weight ratio)", the other raw materials and their amounts are the same as in Example 1. The preparation steps are the same as in Example 1.

[0044] Comparative Example 3 A conventional waterborne alkyd resin, without the addition of bis(4-carboxyphenyl)phenylphosphine oxide and 4,4'-dihydroxydiphenyl ether, comprises the following components by weight:

[0045] The preparation steps for this comparative example are the same as those for Example 1.

[0046] Experimental performance testing: The performance of the aqueous alkyd resins prepared in Examples 1-5 and Comparative Examples 1-3 was tested, and the performance indicators and test methods are shown below:

[0047] The test results are shown below:

[0048] The test results above show that the surface drying time of the resin in the embodiments of the present invention is 1.1-1.5 hours, and the complete drying time is 8.0-10.0 hours, which is 40%-60% faster than that of the comparative example; the pencil hardness of the resin in the embodiments is 2H or higher, the flexibility is ≤2mm, and it is high hardness without being brittle; the water absorption rate of the resin in the embodiments is 1.8-2.5%, which is more than 57% lower than that of comparative example 3 (5.8%); the LOI value of the resin in the embodiments is 28.0-30.0%, reaching the flame retardant level; the resin in the embodiments showed no stratification after 12 months of storage at room temperature, while comparative example 2 showed slight precipitation and comparative example 3 showed stratification. In summary, it can be shown that the comprehensive performance of the resins in embodiments 1-5 of the present invention meets the requirements of high-end coatings and has significant progress compared with the prior art.

[0049] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the invention. The illustrative expressions of the above terms in this specification should not be construed as necessarily referring 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. In addition, those skilled in the art can combine and integrate the different embodiments or examples described in this specification.

[0050] Although embodiments of the present invention have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting the present invention. Those skilled in the art can make changes, modifications, substitutions and variations to the above embodiments within the scope of the present invention.

Claims

1. An environmentally friendly, high-performance waterborne alkyd resin, characterized in that, Calculated by weight, it includes the following ingredients: 30-35 parts bio-based vegetable oil, 15-22 parts polyol, 18-26 parts polyacid, 8-12 parts polyether alcohol modifier, 0.02-0.05 parts catalyst, 0.1-0.3 parts antioxidant, 8-12 parts cosolvent, 0.5-1.5 parts neutralizer, and 40-50 parts deionized water; The polyol is a mixture of pentaerythritol, 4,4'-dihydroxydiphenyl ether and trimethylolpropane; the polyacid is a mixture of isophthalic acid, bis(4-carboxyphenyl)phenylphosphine oxide, adipic acid and trimellitic anhydride.

2. The environmentally friendly, high-performance waterborne alkyd resin according to claim 1, characterized in that, The bio-based vegetable oil is one or more of linseed oil, palm oil, tung oil, castor oil, and peanut oil.

3. The environmentally friendly, high-performance waterborne alkyd resin according to claim 1, characterized in that, The polyol is a mixture of pentaerythritol, 4,4'-dihydroxydiphenyl ether and trimethylolpropane in a weight ratio of 8-12:5-8:4-6.

4. The environmentally friendly, high-performance waterborne alkyd resin according to claim 1, characterized in that, The polybasic acid is a mixture of isophthalic acid, bis(4-carboxyphenyl)phenylphosphine oxide, adipic acid, and trimellitic anhydride in a weight ratio of 8-12:3-5:4-6:2-4.

5. The environmentally friendly, high-performance waterborne alkyd resin according to claim 1, characterized in that, The polyether alcohol modifier is one or more of polyethylene glycol monomethyl ether, polyethylene glycol monooctyl ether, polyethylene glycol monomethyl ether, glyceryl diglycidyl ether, polypropylene glycol oleyl ether, and polyoxyethyl polyoxypropyl glyceryl ether.

6. The environmentally friendly, high-performance waterborne alkyd resin according to claim 1, characterized in that, The catalyst is an organotin catalyst, specifically one or more of dibutyltin dilaurate, dioctyltin dilaurate, and dibutyltin dioctanoate.

7. The environmentally friendly, high-performance waterborne alkyd resin according to claim 1, characterized in that, The antioxidant is a hindered phenolic antioxidant, specifically one or more of antioxidant 1010, antioxidant 1076, antioxidant 1098, and antioxidant 1135.

8. The environmentally friendly, high-performance waterborne alkyd resin according to claim 1, characterized in that, The co-solvent is one or more of propylene glycol methyl ether, dipropylene glycol methyl ether, ethylene glycol methyl ether, and dipropylene glycol butyl ether.

9. The environmentally friendly, high-performance waterborne alkyd resin according to claim 1, characterized in that, The neutralizing agent is ammonia or dimethylethanolamine.

10. A method for preparing the environmentally friendly, high-performance waterborne alkyd resin according to claim 1, characterized in that, Includes the following steps: Step 1: Add vegetable oil, polyol, polyacid and catalyst to the four-necked flask in sequence; Step 2: Under nitrogen protection, gradually increase the temperature from room temperature to 200-210℃. After monitoring the acid value to reach 35-45 mg KOH / g, stop increasing the temperature and cool down to 160-170℃. Step 3: Slowly add the polyether alcohol modifier to the flask and keep it warm while stirring for 1-3 hours; Step 4: Cool down to 80-90℃, add neutralizer, antioxidant and solubilizer, stir well, gradually add deionized water dropwise, after the addition is complete, keep warm to emulsify, and then cool down to below 40℃; Step 5: Filter the emulsion to remove impurities and obtain water-based alkyd resin.

Images