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

Abstract

The invention relates to the field of resin, in particular to a preparation method of environment-friendly high-performance water-based alkyd resin. The water-based alkyd resin is prepared from the following components in parts by weight: 30 to 35 parts of bio-based vegetable oil, 15 to 22 parts of polyhydric alcohol, 18 to 26 parts of polybasic acid, 8 to 12 parts of polyether alcohol modifier, 0.02 to 0.05 part of catalyst, 0.1 to 0.3 part of antioxidant, 8 to 12 parts of cosolvent, 0.5 to 1.5 parts of neutralizer and 40 to 50 parts of deionized water. According to the environment-friendly high-performance water-based alkyd resin provided by the invention, by regulating and controlling the composition and proportion of the raw materials and optimizing preparation process parameters, the synergism and unification of environmental protection property and comprehensive high performance are realized, and the common problems of contradiction between quick-drying property and high hardness, insufficient water resistance, poor storage stability and the like of the existing water-based alkyd resin are effectively solved.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of resin, in particular to a preparation method of environment-friendly high-performance water-based alkyd resin. BACKGROUND

[0002] Alkyd resin is one of the most widely used synthetic resins in the coating industry with the longest history. It is favored due to its easy availability of raw materials, high cost performance and good comprehensive performance. However, traditional solvent-based alkyd resin releases a large amount of volatile organic compounds (VOC) during production and construction, which is harmful to the environment and human health. With the increasingly stringent global environmental regulations and the promotion of the "double carbon" goal, it is inevitable for the coating industry to transform towards low VOC and environmentally friendly direction. Under this background, water-based alkyd resin emerges as the times require. It uses water as the main dispersion medium, which can significantly reduce the use of organic solvents, reduce VOC content by about 400 kg per ton of coating, and has the advantages of safety in production and construction, easy cleaning of equipment, etc.

[0003] Although water-based alkyd resin has significant environmental advantages, it still has many problems in practical application and performance. First, the drying speed is slow, the initial hardness is too low, and the latent heat of water evaporation is much higher than that of organic solvents, which leads to a significant extension of the film surface drying and real drying time, affecting the construction efficiency. Second, poor water resistance and storage stability, which is the most core defect of water-based alkyd resin, the ester bond in the resin main chain is prone to hydrolysis reaction in weak alkaline or aqueous environment, leading to the breakage of resin molecular chain.

[0004] Therefore, it is of great practical significance and commercial value to develop a method for preparing water-based alkyd resin with green raw materials and simultaneously giving it comprehensive high performance such as fast drying, high hardness, excellent water resistance and storage stability, etc. to promote the application of water-based alkyd resin in high-end industrial protection, wood coatings and other fields. SUMMARY

[0005] In view of the problems existing in the prior art, the purpose of the present application is to provide a preparation method of environment-friendly high-performance water-based alkyd resin.

[0006] The purpose of the present application is achieved by adopting the following technical solutions: In a first aspect, the present application provides an environment-friendly high-performance water-based alkyd resin, which comprises the following components in terms of 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.

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

[0008] Preferably, the polyol is one or more of 4,4'-dihydroxydiphenyl ether, pentaerythritol, trimethylolpropane, neopentyl glycol, diethylene glycol, 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)phenyl phosphine oxide, adipic acid and trimellitic anhydride; wherein the weight ratio of isophthalic acid, bis(4-carboxyphenyl)phenyl phosphine 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, tetraethylene glycol monooctyl ether, pentaethylene glycol monomethyl ether, glycerol diglycidyl ether, polypropylene glycol oleyl ether, polyoxyethyl polyoxypropyl glycerol ether.

[0012] Preferably, the catalyst is an organic tin catalyst, specifically one or more of dibutyltin dilaurate (DBTDL), dioctyltin dilaurate (DOTDL), dibutyltin octoate (DBTO).

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

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

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

[0016] In a second aspect, the present application provides a preparation method of an environmentally friendly high-performance water-based alkyd resin, comprising the following steps: Step 1: Add plant oil, polyol, polybasic acid and catalyst to a four-necked flask in sequence; Step 2: Under nitrogen protection, gradually increase the temperature from room temperature to 200-210°C, and stop increasing the temperature when the acid value reaches the set standard, and then cool to 160-170°C; Step 3: Slowly add polyether alcohol modifier to the flask, and heat and stir for 1-3h; Step 4, cooling to 80-90℃, adding neutralizing agent, antioxidant and cosolvent, stirring uniformly, gradually adding deionized water, after the dropwise addition is completed, emulsifying, and then cooling to below 40℃; Step 5, filtering the emulsion to remove impurities to obtain the water-based alkyd resin.

[0017] Preferably, in step 1, the vegetable oil, polyol, polybasic acid 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 1h, then heating to 160℃, holding for 2h, then heating to 190℃, holding for 3h, and then continuously heating to 200-210℃.

[0019] Preferably, in step 2, after heating to 200-210℃, sample detection of acid value is performed every half hour until the acid value reaches 35-45mgKOH / g, and the heating is stopped.

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

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

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

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

[0024] The beneficial effects of the present application are: 1. The environmentally friendly high-performance water-based alkyd resin provided by the present application realizes the synergistic unity of environmental protection and comprehensive high performance by adjusting the composition and ratio of raw materials and optimizing the preparation process parameters, effectively solving the problems of fast drying and high hardness contradiction, poor water resistance, poor storage stability and the like commonly existing in the existing water-based alkyd resin.

[0025] 2. In the process of preparing the alkyd resin, the renewable bio-based vegetable oil is used as the main raw material, the high unsaturation on the fatty acid chain provides rich oxidation crosslinking sites for the paint film; and the synergistic setting of the three polyol systems, combined with the esterification process of step-by-step heating, jointly constructs a high crosslinking density molecular skeleton, which greatly shortens the surface drying and real drying time of the paint film, meeting the high efficiency construction requirements. In addition, the introduction of bis(4-carboxyphenyl) phenyl phosphine oxide also brings potential flame retardant function to the resin, and the contained phosphorus element can promote carbonization and interrupt the combustion process during combustion, expanding the application prospect of the resin in special fields such as fireproof paint.

[0026] 3、4,4'-dihydroxydiphenyl ether in the polyol in the formula of the application and the conjugated system of bis(4-carboxyphenyl)phenyl phosphine oxide in the polybasic acid form a rigid support, the polyhydroxy structure of pentaerythritol improves the crosslinking density, supplemented by adipic acid to provide flexible segments, so that the mechanical properties of the paint film reach the balance of high hardness and not brittle. Among them, 4,4'-dihydroxydiphenyl ether and bis(4-carboxyphenyl)phenyl phosphine oxide have significant synergies in the resin system, the aromatic ring structure in the molecules of the two together improves the packing density of the molecular chain, reduces the exposure of the hydrophilic group of the paint film, reduces the penetration rate of water or acid-base medium, and improves the water resistance and chemical corrosion resistance of the paint film.

[0027] 4、The application optimizes the raw material pretreatment and emulsification process, so that the resin emulsion particle size is uniform, the dispersion stability is excellent, the obtained product can be stored for more than 12 months under room temperature sealed storage conditions, there is no stratification, precipitation, gel phenomenon, the emulsion viscosity change rate is small, and the use requirements of long distance transportation and long term storage are met. DETAILED DESCRIPTION

[0028] The technical solutions of the application are described below through specific specific examples. It should be understood that the one or more method steps mentioned in the application do not exclude other method steps before and after the combination steps or other method steps can be inserted between the explicitly mentioned steps; it should also be understood that these examples are only used to illustrate the application and not to limit the scope of the application. Moreover, unless otherwise stated, the numbering of each method step is only a convenient tool to identify each method step, and is not a limitation on the arrangement order or the scope of the application that can be implemented. The change or adjustment of the relative relationship is also considered as the scope of the application that can be implemented without substantially changing the technical content.

[0029] In order to better understand the above technical solutions, the exemplary embodiments of the application are described in more detail below. Although exemplary embodiments of the application are shown, it should be understood that the application can be implemented in various forms and should not be limited by the embodiments described herein. On the contrary, these embodiments are provided to enable a more thorough understanding of the application and to convey the scope of the application to those skilled in the art.

[0030] The plant oils used in the examples or comparative examples of the application are all industrial grade plant oils.

[0031] The application will be further described below in conjunction with the following examples.

[0032] Example 1 An environmentally friendly high-performance water-based alkyd resin, according to weight fraction, includes the following ingredients: An environmentally friendly high-performance water-based alkyd resin, according to weight fraction, includes the following ingredients:

[0033] The preparation method of the above-mentioned environment-friendly high-performance water-based alkyd resin comprises the following steps: Step 1, a four-necked flask with a stirrer, a thermometer, a reflux condenser and a water separator is sequentially added with dried plant oil, polyhydric alcohol, polybasic acid and a catalyst; Step 2, under nitrogen protection, gradually increase the temperature at a rate of 5℃ / min, first from room temperature to 120℃, keep for 1h, then increase to 160℃, keep for 2h, then increase to 190℃, keep for 3h, and continue to increase to 210℃; sample every half hour to detect the acid value until the acid value reaches 40mgKOH / g, stop increasing the temperature, and decrease to 170℃; Step 3, slowly add a polyether alcohol modifier into the flask, increase the stirring rate to 500r / min, and keep at 170℃ for 2h; Step 4, decrease to 85℃, add a neutralizing agent, an antioxidant and a cosolvent, stir for 30min, keep at 85℃, gradually add deionized water within 1h, increase the stirring rate to 800r / min during the adding process, form a stable oil-in-water emulsion, keep at 85℃ for 1h after the adding is completed, and then decrease to below 40℃; Step 5, filter the emulsion with a 200-mesh nylon filter screen to remove impurities, and obtain the water-based alkyd resin.

[0034] Example 2 An environment-friendly high-performance water-based alkyd resin comprises the following ingredients in terms of weight fraction:

[0035] The preparation method of the above-mentioned environment-friendly high-performance water-based alkyd resin comprises the following steps: Step 1, a four-necked flask with a stirrer, a thermometer, a reflux condenser and a water separator is sequentially added with dried plant oil, polyhydric alcohol, polybasic acid and a catalyst; Step 2, under nitrogen protection, gradually increase the temperature at a rate of 5℃ / min, first from room temperature to 120℃, keep for 1h, then increase to 160℃, keep for 2h, then increase to 190℃, keep for 3h, and continue to increase to 200℃; sample every half hour to detect the acid value until the acid value reaches 35mgKOH / g, stop increasing the temperature, and decrease to 160℃; Step 3, slowly add a polyether alcohol modifier into the flask, increase the stirring rate to 500r / min, and keep at 160℃ for 2h; Step 4, cool down to 80℃, add neutralizing agent, antioxidant and cosolvent, stir for 20 min, stirring rate 200 r / min, keep 80℃, gradually add deionized water in 1 h, stirring rate increases to 800 r / min during the process, form stable oil-in-water emulsion; after the addition is completed, keep 85℃ for 1 h, then cool down to below 40℃; Step 5, filter the emulsion with 200 mesh nylon filter screen to remove impurities, obtain water-based alkyd resin.

[0036] Example 3 An environmentally friendly high-performance water-based alkyd resin, including the following ingredients by weight:

[0037] The preparation method of the above-mentioned environmentally friendly high-performance water-based alkyd resin includes the following steps: Step 1, add dry treated vegetable oil, polyol, polybasic acid and catalyst into a four-necked flask with stirrer, thermometer, reflux condenser and water separator in sequence; Step 2, gradually increase the temperature under nitrogen protection, the temperature increasing rate is 5℃ / min, first increase from room temperature to 120℃, keep for 1 h, then increase to 160℃, keep for 2 h, then increase to 190℃, keep for 3 h, continue to increase to 210℃; take sample every half hour to detect acid value until the acid value reaches 35 mgKOH / g, stop increasing the temperature, and cool down to 170℃; Step 3, slowly add polyether alcohol modifier into the flask, increase the stirring rate to 500 r / min, keep 170℃ for 2 h; Step 4, cool down to 85℃, add neutralizing agent, antioxidant and cosolvent, stir for 20 min, stirring rate 200 r / min, keep 85℃, gradually add deionized water in 1 h, stirring rate increases to 800 r / min during the process, form stable oil-in-water emulsion; after the addition is completed, keep 85℃ for 1 h, then cool down to below 40℃; Step 5, filter the emulsion with 200 mesh nylon filter screen to remove impurities, obtain water-based alkyd resin.

[0038] Example 4 An environmentally friendly high-performance water-based alkyd resin, including the following ingredients by weight:

[0039] The preparation method of the above-mentioned environmentally friendly high-performance water-based alkyd resin includes the following steps: Step 1, add dry treated vegetable oil, polyol, polybasic acid and catalyst into a four-necked flask with stirrer, thermometer, reflux condenser and water separator in sequence; Step 2, under the protection of nitrogen, gradually increase the temperature at a rate of 5℃ / min, first from room temperature to 120℃, keep for 1h, then increase to 160℃, keep for 2h, then increase to 190℃, keep for 3h, continue to increase to 210℃; every half hour to sample test acid value, until the acid value reaches 45mgKOH / g, stop heating, cooling to 170℃; Step 3, slowly add polyether alcohol modifier to the flask, increase the stirring rate to 500r / min, keep at 170℃ for 2h; Step 4, cool to 85℃, add neutralizer, antioxidant and cosolvent, stir for 30min, stirring rate 300r / min, keep at 85℃, gradually add deionized water within 1h, stirring rate increases to 800r / min during the process, form stable oil-in-water emulsion; after the addition is completed, keep at 85℃ for 1h, then cool to below 40℃; Step 5, filter the emulsion with 200 mesh nylon filter screen to remove impurities, get water-based alkyd resin.

[0040] Example 5 An environmentally friendly high-performance water-based alkyd resin, including the following ingredients by weight:

[0041] The preparation method of the above-mentioned environmentally friendly high-performance water-based alkyd resin, including the following steps: Step 1, add dry treated vegetable oil, polyol, polyacid and catalyst to the four-necked flask with stirrer, thermometer, reflux condenser and water separator in turn; Step 2, under the protection of nitrogen, gradually increase the temperature at a rate of 5℃ / min, first from room temperature to 120℃, keep for 1h, then increase to 160℃, keep for 2h, then increase to 190℃, keep for 3h, continue to increase to 210℃; every half hour to sample test acid value, until the acid value reaches 40mgKOH / g, stop heating, cooling to 160℃; Step 3, slowly add polyether alcohol modifier to the flask, increase the stirring rate to 500r / min, keep at 160℃ for 2h; Step 4, cool to 90℃, add neutralizer, antioxidant and cosolvent, stir for 20-30min, stirring rate 300r / min, keep at 90℃, gradually add deionized water within 1h, stirring rate increases to 800r / min during the process, form stable oil-in-water emulsion; after the addition is completed, keep at 85℃ for 1h, then cool to below 40℃; Step 5, filter the emulsion with 200 mesh nylon filter screen to remove impurities, get water-based alkyd resin.

[0042] Comparative Example 1 An aqueous alkyd resin, without adding bis(4-carboxyphenyl)phenyl phosphine oxide, i.e. except that the polybasic acid is replaced by "isophthalic acid: adipic acid: TMA = 14:5:3 (weight ratio)" in the raw material composition, the rest of the raw materials and the amount are consistent with Example 1. The preparation steps are consistent with Example 1.

[0043] Comparative Example 2 An aqueous alkyd resin, without adding 4,4'-dihydroxy diphenyl ether, i.e. except that the polyol is replaced by "pentaerythritol: trimethylolpropane = 15:6 (weight ratio)" in the raw material composition, the rest of the raw materials and the amount are consistent with Example 1. The preparation steps are consistent with Example 1.

[0044] Comparative Example 3 A conventional aqueous alkyd resin, without adding bis(4-carboxyphenyl)phenyl phosphine oxide and 4,4'-dihydroxy diphenyl ether, including the following ingredients, calculated by weight fraction:

[0045] The preparation steps of the present comparative example are consistent with Example 1.

[0046] Experimental performance test: The aqueous alkyd resins prepared in Examples 1-5 and Comparative Examples 1-3 were tested for performance, and the performance indicators and test methods are shown as follows:

[0047] The results of the test are as follows:

[0048] From the above test results, it can be seen that the resin of the present application has a dry time of 1.1-1.5h and a dry time of 8.0-10.0h, which is 40%-60% faster than the comparative examples; the pencil hardness of the resin of the examples is 2H or more, the flexibility is ≤2mm, and the high hardness is not brittle; the water absorption rate of the resin of the examples is 1.8-2.5%, which is reduced by more than 57% compared with Comparative Example 3 (5.8%); the LOI value of the resin of the examples is 28.0-30.0%, reaching the flame retardant level; the resin of the examples is stored at room temperature for 12 months without delamination, Comparative Example 2 has a slight precipitation, and Comparative Example 3 is delaminated. In summary, it can be shown that the comprehensive performance of the resin of Examples 1-5 of the present application meets the demand of high-end coatings, and has a more significant progress compared with the prior art.

[0049] In the description of the specification, the description of the terms "one embodiment", "some embodiments", "an example", "a specific example", or "some examples" etc. means that the specific features, structures, materials or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of the present application. In the specification, the illustrative description of the above terms should not be understood as necessarily referring to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any suitable manner in one or more embodiments or examples. In addition, those skilled in the art can combine and integrate different embodiments or examples described in the specification.

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

Claims

1. An environmentally friendly high performance waterborne alkyd resin, characterized in that, According to the weight parts, the following ingredients are included: 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 polyol is a mixture of pentaerythritol, 4,4'-dihydroxy diphenyl ether, and trimethylolpropane; the polybasic acid is a mixture of isophthalic acid, bis(4-carboxyphenyl)phenyl phosphine 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'-dihydroxy diphenyl 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)phenyl phosphine 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, tetrapolyethylene glycol monooctyl ether, pentapolyethylene glycol monomethyl ether, glycerol diglycidyl ether, polypropylene glycol oleyl ether, and polyoxyethyl polyoxypropyl glycerol ether.

6. The environmentally friendly high performance waterborne alkyd resin according to claim 1, characterized in that, The catalyst is an organic tin catalyst, specifically one or more of dibutyl tin dilaurate, dioctyl tin dilaurate, and dibutyl tin 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 cosolvent 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 dimethyl ethanolamine.

10. A method for preparing the environmentally friendly, high-performance waterborne alkyd resin according to claim 1, characterized in that, The following steps are included: Step 1: Add vegetable oil, polyol, polybasic acid, and catalyst to a four-necked flask in sequence; Step 2: Under nitrogen protection, gradually increase the temperature from room temperature to 200-210°C, and stop increasing the temperature when the acid value reaches 35-45 mg KOH / g, then cool to 160-170°C; Step 3: Slowly add polyether alcohol modifier to the flask, and stir for 1-3 h; Step 4: Cool to 80-90°C, add neutralizing agent, antioxidant, and cosolvent, stir until uniform, then gradually add deionized water, after the addition is complete, emulsify, then cool to below 40°C; Step 5: Filter the emulsion to remove impurities, and obtain the water-based alkyd resin.

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