A kind of waterborne acrylic acid modified alkyd resin and preparation method thereof

Abstract

The present application discloses a water-based acrylic acid modified alkyd resin and a preparation method thereof, and relates to the technical field of resin preparation. The present application obtains an acrylic acid copolymer product including a nitrogen-containing five-membered ring structure by copolymerizing acrylic acid 2-hydroxyethyl ester and N-(2-hydroxyethyl) maleimide, and then the acrylic acid copolymer product is modified by diisocyanate to obtain a modified acrylic acid copolymer including an isocyanate group-hydroxy cross-linked structure. The obtained modified acrylic acid copolymer, unsaturated fatty acid, diol, trimethylolpropane and xylene are then mixed for preliminary reaction; then further reacted with an organic acid anhydride containing a carbon-carbon double bond; finally neutralized with a neutralizing agent to obtain a water-based acrylic acid modified alkyd resin. The water-based acrylic acid modified alkyd resin prepared by the present application has higher hardness, stronger tolerance, higher wear resistance and adhesion, and has a wide range of market application prospects.

Description

Technical Field

[0001] The present application relates to the technical field of resin preparation, and specifically to a water-based acrylic acid-modified alkyd resin and a preparation method thereof. Background Art

[0002] With the advancement of science and technology, increasingly stringent environmental protection regulations and people's gradual improvement of environmental awareness, the emission of volatile organic compounds (VOC) has attracted more and more attention. VOC not only poses a threat to human health, but also leads to the destruction of the ozone layer and the formation of photochemical smog through chemical reactions. In addition, VOC also has a significant impact on regional air pollution. Therefore, the more traditional solvent-based coatings are gradually being replaced by water-based coatings due to their common volatile organic compound (VOC) emission problems. Water-based coatings have become an important development direction in the coating field with their advantages such as low VOC emissions and non-toxic or low toxicity.

[0003] As an important component of waterborne coatings, the research and development and application of waterborne alkyd resins have received extensive attention. However, the existing commonly used unmodified waterborne alkyd resins still have deficiencies in tolerance, hardness, etc., which limits their use in certain high-demand applications. At present, there are some acrylic modified, epoxy modified, and polyurethane modified alkyd resin products on the market, which have overcome the deficiencies of traditional alkyd resins to a certain extent. However, while these products improve tolerance, they may sacrifice certain advantages such as adhesion. In addition, compatibility and other problems that may arise during the modification process will also affect the stability and application performance of the final modified alkyd resin product.

[0004] The Chinese patent with publication number CN 109306037A discloses a water-based acrylic acid modified alkyd resin and a preparation method thereof. The water-based acrylic acid modified alkyd resin is prepared from the raw materials of 22-24% dry or semi-dry vegetable oil acid, 14-15% triol with side chain, 13-14% phthalic anhydride, 0.05-0.15% color reducing agent, 1-3% reflux xylene, 0.7-1% maleic anhydride, 2.5-2.7% trimellitic anhydride, 4-5% methyl methacrylate, 6-8% styrene, 1-2% butyl acrylate, 0.5-1% initiator, and 28-29% propylene glycol methyl ether. Although the water-based acrylic modified alkyd resin obtained by the invention is environmentally friendly, low in toxicity, and maintains excellent comprehensive properties such as gloss, adhesion and hardness, it does not introduce a nitrogen-containing five-membered ring structure and an isocyanate group-hydroxyl cross-linking structure, and the formula composition is very different. There is still much room for improvement in properties such as hardness, adhesion, and tolerance. Summary of the invention

[0005] In view of the deficiencies in the prior art, the present application provides a water-based acrylic modified alkyd resin and a preparation method thereof, to prepare a water-based acrylic modified alkyd resin with higher hardness, stronger tolerance, higher wear resistance and adhesion, and with broad market application prospects, the main component of which is a modified acrylic copolymer including a nitrogen-containing five-membered ring structure and an isocyanate group-hydroxyl cross-linking structure.

[0006] In order to achieve the above objectives, this application adopts the following technical solutions:

[0007] In a first aspect, the present application provides a waterborne acrylic modified alkyd resin, the resin comprising at least one chain polymer structure; the chain polymer structure is represented by one or more of the following structures:

[0008] ,

[0009] .

[0010] Wherein, R is one or more of the following structures:

[0011] , , , , and .

[0012] The chain polymer structure includes a nitrogen-containing five-membered ring structure and an isocyanate group-hydroxyl cross-linking structure.

[0013] The nitrogen-containing five-membered ring structure is represented by the following structure:

[0014]

[0015] The isocyanate group-hydroxyl crosslinking structure is represented by one or more of the following structures:

[0016] ,

[0017] .

[0018] Wherein, R is one or more of the following structures:

[0019] , , , , and .

[0020] In a second aspect, the present application provides a method for preparing a waterborne acrylic acid-modified alkyd resin, the preparation method comprising:

[0021] Weigh the modified acrylic copolymer, unsaturated fatty acid, diol, trimethylolpropane and xylene respectively, add them into the reaction kettle, stir and heat to 230-250°C under nitrogen protection, and keep reflux for 2-2.5 hours;

[0022] The temperature was lowered to 160-180°C, and then an organic acid anhydride containing a carbon-carbon double bond was weighed and added to the reaction kettle, and the temperature was kept at 160-180°C for 1-2 hours;

[0023] The temperature is then lowered to 80-100° C., a neutralizing agent is weighed and added into the reaction kettle, and stirring is continued at 80-100° C. for 30-40 minutes to obtain a waterborne acrylic acid modified alkyd resin.

[0024] The above preparation method further comprises: preparing the modified acrylic copolymer; the preparation method of the modified acrylic copolymer comprises:

[0025] Weigh N-(2-hydroxyethyl)maleimide and xylene respectively, add them into the reaction kettle, and pass nitrogen for 20 to 40 minutes;

[0026] Then, the temperature is raised to 160-180°C, and then, under reflux, a mixture of 2-hydroxyethyl acrylate, a chain transfer agent, and half the mass of the initiator is added dropwise to the reaction kettle within 2-3 hours, and the mixture is kept under reflux for 0.5-1 hour;

[0027] Then add the remaining half of the mass of the initiator into the reactor, keep the temperature at 160-180°C and reflux for 1.5-2h to obtain the acrylic copolymer product, then weigh the diisocyanate and add it into the reactor, continue to keep the temperature at 160-180°C and reflux for 1-2h; finally cool down to 70-90°C and discharge the material to obtain the modified acrylic copolymer.

[0028] Beneficial technical effects:

[0029] The present invention uses N-(2-hydroxyethyl) maleimide and 2-hydroxyethyl acrylate to undergo a copolymerization reaction between carbon-carbon double bonds to obtain an acrylic copolymer product, and then uses diisocyanate to further react with the hydroxyl group in the acrylic copolymer product to obtain a modified acrylic copolymer including a nitrogen-containing five-membered ring structure and an isocyanate group-hydroxyl cross-linking structure. The modified acrylic copolymer is then used as a main component to react with unsaturated fatty acids, diols, trimethylolpropane, and an organic acid anhydride containing a carbon-carbon double bond in xylene, and finally a neutralizer is added for neutralization to obtain a water-based acrylic modified alkyd resin.

[0030] The main component of the waterborne acrylic modified alkyd resin prepared in the present application includes a modified acrylic copolymer. The nitrogen-containing five-membered ring structure in the modified acrylic copolymer can increase the hardness, tolerance and wear resistance of the waterborne acrylic modified alkyd resin.

[0031] The modified acrylic copolymer also includes a reinforced cross-linking structure formed by the reaction of isocyanate groups and hydroxyl groups, which further improves the hardness, tolerance and wear resistance of the waterborne acrylic modified alkyd resin. At the same time, the -NH-COO- structure retained after the reaction of isocyanate groups and hydroxyl groups in the structure can form intermolecular hydrogen bonds, thereby further enhancing the adhesion of the material.

[0032] The water-based acrylic modified alkyd resin prepared in the present application has higher hardness, excellent tolerance and wear resistance, and higher adhesion, and has broad market application prospects. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] Figure 1 This is the preparation route of the modified acrylic copolymer of the present application.

[0034] Figure 2 Schematic diagram of the structure of the waterborne acrylic acid modified alkyd resin prepared in Example 1.

[0035] Figure 3 It is a flow chart of the preparation method of the water-based acrylic acid modified alkyd resin of Examples 1-6. DETAILED DESCRIPTION

[0036] In order to make the technical problems, technical solutions and beneficial effects to be solved by the present application clearer, the present application is further described in detail below in conjunction with the embodiments. However, this should not be understood as the scope of the present application being limited to the following examples. Without departing from the above-mentioned method ideas of the present application, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of this application.

[0037] Before introducing this application, the relevant terms involved in this application are explained as follows:

[0038] Chain polymerization structure: Using different small molecule monomers containing carbon-carbon double bonds, copolymerization occurs through the breaking and reconnection of the carbon-carbon double bonds, resulting in a chain structure with a carbon chain as the main trunk.

[0039] Nitrogen-containing five-membered ring structure: a ring structure consisting of five atoms, which are connected by covalent bonds to form a closed ring. In this type of five-membered ring, at least one atom is nitrogen.

[0040] Isocyanate group-hydroxyl cross-linking structure: Isocyanate group (-NCO) reacts with hydroxyl group (-OH) to form a covalent bond, thereby realizing a chemical cross-linking structure between polymer chains.

[0041] In a first aspect, the present application provides a water-based acrylic modified alkyd resin, which includes at least one chain polymerization structure; the chain polymerization structure includes a nitrogen-containing five-membered ring structure and an isocyanate group-hydroxyl cross-linking structure; the nitrogen-containing five-membered ring structure is derived from an acrylic copolymer obtained by reacting 2-hydroxyethyl acrylate and N-(2-hydroxyethyl)maleimide; and the isocyanate group-hydroxyl cross-linking structure is derived from a modified acrylic copolymer obtained by modifying the acrylic copolymer by diisocyanate.

[0042] In a possible implementation, the chain polymer structure is represented by one or more of the following structures:

[0043] ,

[0044] .

[0045] Wherein, R is one or more of the following structures:

[0046] , , , , and .

[0047] The chain polymer structure includes a nitrogen-containing five-membered ring structure and an isocyanate group-hydroxyl cross-linking structure.

[0048] In a possible implementation, the nitrogen-containing five-membered ring structure is represented by the following structure:

[0049]

[0050] In a possible implementation, the isocyanate group-hydroxyl cross-linking structure is represented by one or more of the following structures:

[0051] ,

[0052] .

[0053] Wherein, R is one or more of the following structures:

[0054] , , , , and .

[0055] It is precisely because of the presence of the nitrogen-containing five-membered ring structure and the isocyanate group-hydroxyl cross-linking structure that the hardness, tolerance and wear resistance of the water-based acrylic modified alkyd resin can be improved. At the same time, the -NH-COO- structure retained after the reaction of the isocyanate group and the hydroxyl group can form intermolecular hydrogen bonds, thereby further enhancing the adhesion of the material.

[0056] In a second aspect, the present application provides a method for preparing a waterborne acrylic acid-modified alkyd resin, and the preparation method is specifically as follows:

[0057] Weigh the modified acrylic copolymer, unsaturated fatty acid, diol, trimethylolpropane and xylene respectively, add them into the reaction kettle, stir and heat to 230-250°C under nitrogen protection, and keep reflux for 2-2.5 hours;

[0058] The temperature was lowered to 160-180°C, and then an organic acid anhydride containing a carbon-carbon double bond was weighed and added to the reaction kettle, and the temperature was kept at 160-180°C for 1-2 hours;

[0059] The temperature is then lowered to 80-100° C., a neutralizing agent is weighed and added into the reaction kettle, and stirring is continued at 80-100° C. for 30-40 minutes to obtain a waterborne acrylic acid modified alkyd resin.

[0060] In a possible implementation, the mass ratio of the modified acrylic copolymer, unsaturated fatty acid, diol, trimethylolpropane, xylene, organic acid anhydride containing carbon-carbon double bonds, and neutralizer is (20-45): (15-20): (3-5): (5-15): (20-30): (10-25): (1.5-6).

[0061] In a possible implementation, the unsaturated fatty acid includes one or more of oleic acid, trans-oleic acid, palmitoleic acid, ricinoleic acid, linoleic acid, linolenic acid, and arachidonic acid; the diol includes one or more of ethylene glycol, propylene glycol, diethylene glycol, 1,4-butanediol, and neopentyl glycol. When the amount of organic acid anhydride containing a carbon-carbon double bond is within the above range, the reaction rate of preparing the waterborne acrylic acid modified alkyd resin is faster.

[0062] In a possible implementation, the organic acid anhydride containing a carbon-carbon double bond includes one or more of alkenyl succinic anhydride, citraconic anhydride, maleic anhydride, and methyl nadic anhydride.

[0063] In a possible implementation, the neutralizing agent includes one or more of ammonia water, triethylamine, and potassium hydroxide.

[0064] The preparation method of the waterborne acrylic acid modified alkyd resin also includes preparing the modified acrylic acid copolymer; the preparation method of the modified acrylic acid copolymer is specifically as follows:

[0065] Weigh N-(2-hydroxyethyl)maleimide and xylene respectively, add them into the reaction kettle, and pass nitrogen for 20 to 40 minutes;

[0066] Then, the temperature is raised to 160-180°C, and then, under reflux, a mixture of 2-hydroxyethyl acrylate, a chain transfer agent, and half the mass of the initiator is added dropwise to the reaction kettle within 2-3 hours, and the mixture is kept under reflux for 0.5-1 hour;

[0067] Then add the remaining half of the initiator to the reactor, keep it warm at 160-180°C and reflux for 1.5-2h to obtain the acrylic acid copolymer product, then weigh the diisocyanate and add it to the reactor, keep it warm at 160-180°C and reflux for 1-2h; finally cool it to 70-90°C and discharge it to obtain the modified acrylic acid copolymer. The preparation route is as follows: Figure 1 shown.

[0068] In a possible implementation, the mass ratio of N-(2-hydroxyethyl)maleimide, xylene, 2-hydroxyethyl acrylate, chain transfer agent, half of the mass of initiator, the remaining half of the mass of initiator, and diisocyanate is (15-25): (25-35): (25-50): (1-4): (0.5-3): (0.5-3): (5-15). When the added amount of the chain transfer agent and half of the mass of the initiator is within the above range, the obtained acrylic copolymer has a suitable reactivity; when the added amount of the diisocyanate is within the above range, the obtained modified acrylic copolymer having a nitrogen-containing five-membered ring structure and an isocyanate group-hydroxyl cross-linking structure has a suitable reactivity.

[0069] In a possible implementation, the chain transfer agent is one or more of α-methylstyrene dimer and dodecyl mercaptan.

[0070] In a possible implementation, the initiator is one or more of azobisisobutyronitrile, dibenzoyl peroxide, tert-butyl perbenzoate, and methyl ethyl ketone peroxide.

[0071] In a possible implementation, the diisocyanate is one or more of diphenylmethane diisocyanate, hexamethylene diisocyanate, isophorone diisocyanate, naphthalene diisocyanate, p-phenylene diisocyanate, and toluene diisocyanate.

[0072] The experimental raw materials used in this application come from the following sources:

[0073] N-(2-Hydroxyethyl)maleimide: Shanghai MacLean Biochemical Technology Co., Ltd.;

[0074] 2-Hydroxyethyl acrylate: Shanghai MacLean Biochemical Technology Co., Ltd.;

[0075] Chain transfer agent: Shanghai MacLean Biochemical Technology Co., Ltd.;

[0076] Initiator: Shanghai MacLean Biochemical Technology Co., Ltd.;

[0077] Diisocyanate: Shanghai MacLean Biochemical Technology Co., Ltd.;

[0078] Unsaturated fatty acids: Shanghai MacLean Biochemical Technology Co., Ltd.;

[0079] Diol: Shanghai MacLean Biochemical Technology Co., Ltd.;

[0080] Trimethylolpropane: Shanghai MacLean Biochemical Technology Co., Ltd.;

[0081] Organic anhydrides containing carbon-carbon double bonds: Shanghai MacLean Biochemical Technology Co., Ltd.;

[0082] Neutralizer: Shanghai MacLean Biochemical Technology Co., Ltd.;

[0083] Xylene: Shanghai MacLean Biochemical Technology Co., Ltd.;

[0084] The following will specifically describe a water-based acrylic modified alkyd resin and a preparation method thereof provided by the present application in combination with different examples.

[0085] Embodiment 1:

[0086] like Figure 3 As shown, a method for preparing a water-based acrylic acid modified alkyd resin comprises the following steps:

[0087] 1. Weigh N-(2-hydroxyethyl)maleimide and xylene, add them into a reactor, and pass nitrogen for 30 minutes; in addition to the nitrogen protection, other inert gases or active gases inert to the reaction system can also be used;

[0088] 2. Raise the temperature to 170°C, then add a mixture of 2-hydroxyethyl acrylate, α-methylstyrene dimer and half the mass of the initiator tert-butyl perbenzoate dropwise into the reactor within 2.5 hours under reflux, and keep the mixture under reflux for 0.75 hours;

[0089] 3. Subsequently, the remaining half of the mass of the initiator tert-butyl peroxybenzoate was added, and the mixture was kept refluxed at 170° C. for 1.75 h to obtain an acrylic acid copolymer product; then, hexamethylene diisocyanate was weighed and added to the reaction kettle, and the mixture was kept refluxed at 170° C. for 1.5 h; finally, the mixture was cooled to 80° C. and discharged to obtain a modified acrylic acid copolymer;

[0090] In steps 1 to 3, the mass ratio of the N-(2-hydroxyethyl)maleimide, xylene, 2-hydroxyethyl acrylate, α-methylstyrene dimer, half the mass of tert-butyl perbenzoate, the remaining half the mass of tert-butyl perbenzoate, and hexamethylene diisocyanate is 20:30:35:2:1.5:1.5:10;

[0091] 4. Weigh the modified acrylic acid copolymer, ricinoleic acid, 1,4-butanediol, trimethylolpropane and xylene obtained in step 3 respectively, and add them into the reaction kettle; stir and slowly heat to 240° C. under nitrogen protection, and keep reflux for 2.25 h; in addition to the nitrogen protection, other inert gases or active gases inert to the reaction system can also be used;

[0092] 5. Cool down to 170°C, then weigh methyl nadic anhydride and add it to the reactor, and continue to reflux at 170°C for 1.5 hours;

[0093] 6. Further cool down to 90°C, then weigh triethylamine and add it into the reaction kettle, and continue stirring at 90°C for 35 minutes to obtain a waterborne acrylic acid modified alkyd resin;

[0094] In steps 4 to 6, the mass ratio of the modified acrylic acid copolymer, ricinoleic acid, 1,4-butanediol, trimethylolpropane, xylene, methyl nadic anhydride, and triethylamine is 25:15:4:10:28:14:4.

[0095] The structure of the waterborne acrylic acid modified alkyd resin prepared in Example 1 is as follows: Figure 2 shown.

[0096] Embodiment 2:

[0097] like Figure 3 As shown, a method for preparing a water-based acrylic acid modified alkyd resin comprises the following steps:

[0098] 1. Weigh N-(2-hydroxyethyl)maleimide and xylene, add them into a reactor, and pass nitrogen for 40 minutes; in addition to the nitrogen protection, other inert gases or active gases inert to the reaction system can also be used;

[0099] 2. Raise the temperature to 160°C, then add a mixture of 2-hydroxyethyl acrylate, dodecyl mercaptan and half the mass of the initiator azobisisobutyronitrile dropwise into the reactor within 3 hours under reflux, and keep the mixture under reflux for 1 hour;

[0100] 3. Subsequently, the remaining half of the mass of the initiator azobisisobutyronitrile was added, and the mixture was kept refluxed at 160°C for 2 hours to obtain an acrylic acid copolymer product; then p-phenylene diisocyanate was weighed and added to the reactor, and the mixture was kept refluxed at 160°C for 2 hours; finally, the temperature was lowered to 70°C and the material was discharged to obtain a modified acrylic acid copolymer;

[0101] In steps 1 to 3, the mass ratio of N-(2-hydroxyethyl)maleimide, xylene, 2-hydroxyethyl acrylate, dodecyl mercaptan, half the mass of azobisisobutyronitrile, the remaining half the mass of azobisisobutyronitrile, and p-phenylene diisocyanate is 20:25:30:4:3:3:15;

[0102] 4. Weigh the modified acrylic acid copolymer, palmitic acid, propylene glycol, trimethylolpropane and xylene obtained in step 3 respectively, and add them into the reactor; stir and slowly heat to 250° C. under nitrogen protection, and keep reflux for 2.5 h; in addition to the nitrogen protection, other inert gases or active gases inert to the reaction system can also be used;

[0103] 5. Cool down to 180°C, then weigh citraconic anhydride and add it to the reactor, and continue to reflux at 180°C for 2h;

[0104] 6. Further cool down to 80°C, then weigh triethylamine and add it into the reaction kettle, and continue stirring at 80°C for 40 minutes to obtain a water-based acrylic acid modified alkyd resin;

[0105] In steps 4 to 6, the mass ratio of the modified acrylic acid copolymer, palmitoleic acid, propylene glycol, trimethylolpropane, xylene, citraconic anhydride, and triethylamine is 30:15:5:10:20:15:5.

[0106] Embodiment 3:

[0107] like Figure 3 As shown, a method for preparing a water-based acrylic acid modified alkyd resin comprises the following steps:

[0108] 1. Weigh N-(2-hydroxyethyl)maleimide and xylene, add them into a reactor, and pass nitrogen for 20 minutes; in addition to the nitrogen protection, other inert gases or active gases inert to the reaction system can also be used;

[0109] 2. Raise the temperature to 180°C, then add a mixture of 2-hydroxyethyl acrylate, α-methylstyrene dimer and half the mass of the initiator dibenzoyl peroxide into the reactor under reflux within 2 hours, and keep the mixture under reflux for 0.5 hours;

[0110] 3. Subsequently, the remaining half of the mass of the initiator dibenzoyl peroxide was added, and the mixture was kept refluxed at 180° C. for 1.5 hours to obtain an acrylic acid copolymer product; then toluene-2,4-diisocyanate was weighed and added to the reaction kettle, and the mixture was kept refluxed at 180° C. for 1 hour; finally, the mixture was cooled to 90° C. and discharged to obtain a modified acrylic acid copolymer;

[0111] In steps 1 to 3, the mass ratio of N-(2-hydroxyethyl)maleimide, xylene, 2-hydroxyethyl acrylate, α-methylstyrene dimer, half the mass of dibenzoyl peroxide, the remaining half the mass of dibenzoyl peroxide, and toluene-2,4-diisocyanate is 25:35:25:1:0.5:0.5:13;

[0112] 4. Weigh the modified acrylic acid copolymer, trans-oleic acid, ethylene glycol, trimethylolpropane and xylene obtained in step 3 respectively, and add them into the reaction kettle; stir and slowly heat to 230° C. under nitrogen protection, and keep reflux for 2 h; in addition to the nitrogen protection, other inert gases or active gases inert to the reaction system can also be used;

[0113] 5. Cool down to 170°C, weigh alkenyl succinic anhydride and add it to the reactor, and continue to reflux at 170°C for 1.5h;

[0114] 6. Further cool down to 85°C, then weigh ammonia water and add it into the reaction kettle, and continue stirring at 85°C for 30 minutes to obtain a water-based acrylic acid modified alkyd resin;

[0115] In steps 4 to 6, the mass ratio of the modified acrylic acid copolymer, trans-oleic acid, ethylene glycol, trimethylolpropane, xylene, alkenyl succinic anhydride, and aqueous ammonia is 20:15:3:5:37:17:3.

[0116] Embodiment 4:

[0117] like Figure 3 As shown, a method for preparing a water-based acrylic acid modified alkyd resin comprises the following steps:

[0118] 1. Weigh N-(2-hydroxyethyl)maleimide and xylene, add them into a reactor, and pass nitrogen for 35 minutes; in addition to the nitrogen protection, other inert gases or active gases inert to the reaction system can also be used;

[0119] 2. Raise the temperature to 165°C, then add a mixture of 2-hydroxyethyl acrylate, dodecyl mercaptan and half the mass of the initiator methyl ethyl ketone peroxide dropwise into the reactor within 2.75 hours under reflux, and keep the mixture under reflux for 0.6 hours;

[0120] 3. Subsequently, the remaining half of the mass of the initiator methyl ethyl ketone peroxide was added, and the mixture was kept refluxed at 165° C. for 1.9 hours to obtain an acrylic acid copolymer product; then 1,5-naphthalene diisocyanate was weighed and added to the reaction kettle, and the mixture was kept refluxed at 165° C. for 1.75 hours; finally, the mixture was cooled to 85° C. and discharged to obtain a modified acrylic acid copolymer;

[0121] In steps 1 to 3, the mass ratio of N-(2-hydroxyethyl)maleimide, xylene, 2-hydroxyethyl acrylate, dodecyl mercaptan, half the mass of methyl ethyl ketone peroxide, the remaining half the mass of methyl ethyl ketone peroxide, and 1,5-naphthalene diisocyanate is 22:32:27:3:2:2:12;

[0122] 4. Weigh the modified acrylic acid copolymer, linolenic acid, neopentyl glycol, trimethylolpropane and xylene prepared in step 3 respectively, and add them into the reaction kettle; stir and slowly heat to 245° C. under nitrogen protection, and keep reflux for 2.3 hours; in addition to the nitrogen protection, other inert gases or active gases inert to the reaction system can also be used;

[0123] 5. Cool down to 175°C, then weigh maleic anhydride and add it to the reactor, and continue to reflux at 175°C for 1.75h;

[0124] 6. Further cool down to 88°C, then weigh potassium hydroxide and add it into the reaction kettle, and continue stirring at 88°C for 38 minutes to obtain a waterborne acrylic acid modified alkyd resin;

[0125] In steps 4 to 6, the mass ratio of the modified acrylic acid copolymer, linolenic acid, neopentyl glycol, trimethylolpropane, xylene, maleic anhydride, and potassium hydroxide is 30:14:5:12:25:10:4.

[0126] Embodiment 5:

[0127] like Figure 3 As shown, a method for preparing a water-based acrylic acid modified alkyd resin comprises the following steps:

[0128] 1. Weigh N-(2-hydroxyethyl)maleimide and xylene, add them into a reactor, and pass nitrogen for 25 minutes; in addition to the nitrogen protection, other inert gases or active gases inert to the reaction system can also be used;

[0129] 2. Raise the temperature to 175°C, then add a mixture of 2-hydroxyethyl acrylate, α-methylstyrene dimer and half the mass of the initiator tert-butyl perbenzoate dropwise into the reactor within 2.5 hours under reflux, and keep the mixture under reflux for 0.55 hours;

[0130] 3. Subsequently, the remaining half of the mass of the initiator tert-butyl peroxybenzoate was added, and the mixture was kept refluxed at 175° C. for 1.6 hours to obtain an acrylic acid copolymer product; then 4,4'-methylenebis(phenyl isocyanate) was weighed and added to the reaction kettle, and the mixture was kept refluxed at 175° C. for 1.4 hours; finally, the mixture was cooled to 82° C. and discharged to obtain a modified acrylic acid copolymer;

[0131] In steps 1 to 3, the mass ratio of N-(2-hydroxyethyl)maleimide, xylene, 2-hydroxyethyl acrylate, α-methylstyrene dimer, half the mass of tert-butyl perbenzoate, the remaining half the mass of tert-butyl perbenzoate, and 4,4'-methylenebis(phenyl isocyanate) is 22:28:30:2:1.5:1.5:15;

[0132] 4. Weigh the modified acrylic copolymer, arachidonic acid, 1,4-butanediol, trimethylolpropane and xylene prepared in step 3 respectively, and add them into the reaction kettle; stir and slowly heat to 235° C. under nitrogen protection, and keep reflux for 2.1 hours; in addition to the nitrogen protection, other inert gases or active gases inert to the reaction system can also be used;

[0133] 5. Cool down to 160°C, then weigh maleic anhydride and add it to the reactor, and continue to reflux at 160°C for 1.5 hours;

[0134] 6. Further cool down to 82°C, then weigh triethylamine and add it into the reaction kettle, and continue stirring at 82°C for 35 minutes to obtain a waterborne acrylic acid modified alkyd resin;

[0135] In steps 4 to 6, the mass ratio of the modified acrylic copolymer, arachidonic acid, 1,4-butanediol, trimethylolpropane, xylene, maleic anhydride, and triethylamine is 25:16:4:10:25:17:3.

[0136] Embodiment 6:

[0137] like Figure 3 As shown, a method for preparing a water-based acrylic acid modified alkyd resin comprises the following steps:

[0138] 1. Weigh N-(2-hydroxyethyl)maleimide and xylene, add them into a reactor, and pass nitrogen for 30 minutes; in addition to the nitrogen protection, other inert gases or active gases inert to the reaction system can also be used;

[0139] 2. Raise the temperature to 172°C, then drop a mixture of 2-hydroxyethyl acrylate, dodecyl mercaptan and half the mass of the initiator azobisisobutyronitrile into the reactor under reflux within 2.8 hours, and keep the mixture under reflux for 0.65 hours;

[0140] 3. Subsequently, the remaining half of the mass of the initiator azobisisobutyronitrile was added, and the mixture was kept refluxed at 172°C for 1.8 hours to obtain an acrylic acid copolymer product; then isophorone diisocyanate was weighed and added to the reaction kettle, and the mixture was kept refluxed at 172°C for 1.6 hours; finally, the temperature was lowered to 84°C and the material was discharged to obtain a modified acrylic acid copolymer;

[0141] In steps 1 to 3, the mass ratio of N-(2-hydroxyethyl)maleimide, xylene, 2-hydroxyethyl acrylate, dodecyl mercaptan, half the mass of azobisisobutyronitrile, the remaining half the mass of azobisisobutyronitrile, and isophorone diisocyanate is 24:33:27:3:2:2:9;

[0142] 4. Weigh the modified acrylic acid copolymer, palmitic acid, neopentyl glycol, trimethylolpropane and xylene obtained in step 3 respectively, and add them into the reactor; stir and slowly heat to 248° C. under nitrogen protection, and keep reflux for 2.4 hours; in addition to the nitrogen protection, other inert gases or active gases inert to the reaction system can also be used;

[0143] 5. Cool down to 178°C, then weigh citraconic anhydride and add it to the reactor, and continue to reflux at 178°C for 1.8h;

[0144] 6. Further cool down to 87°C, then weigh ammonia water and add it into the reaction kettle, and continue stirring at 87°C for 37 minutes to obtain a water-based acrylic acid modified alkyd resin;

[0145] In steps 4 to 6, the mass ratio of the modified acrylic acid copolymer, palmitoleic acid, neopentyl glycol, trimethylolpropane, xylene, citraconic anhydride, and ammonia water is 30:14:5:10:25:11:5.

[0146] Comparative Example 1:

[0147] A method for preparing a waterborne acrylic acid modified alkyd resin comprises the following steps:

[0148] 1. Weigh acrylic anhydride and xylene, add them into a reactor, and pass nitrogen for 30 minutes; in addition to the nitrogen protection, other inert gases or active gases inert to the reaction system can also be used;

[0149] 2. Raise the temperature to 170°C, then add a mixture of ethyl methacrylate, α-methylstyrene dimer and half the mass of the initiator tert-butyl perbenzoate dropwise into the reactor within 2.5 hours under reflux, and keep the mixture under reflux for 0.75 hours;

[0150] 3. Subsequently, the remaining half of the mass of the initiator tert-butyl peroxybenzoate was added, and the mixture was kept at 170° C. for reflux for 1.75 h to obtain an acrylic acid copolymer product; the mixture was kept at 170° C. for reflux for 1.5 h; and the mixture was cooled to 80° C. for discharge to obtain a modified acrylic acid copolymer;

[0151] In steps 1 to 3, the mass ratio of acrylic anhydride, xylene, ethyl methacrylate, α-methylstyrene dimer, half the mass of tert-butyl perbenzoate, and the remaining half the mass of tert-butyl perbenzoate is 25:30:40:2:1.5:1.5;

[0152] 4. Weigh the modified acrylic acid copolymer, ricinoleic acid, 1,4-butanediol, trimethylolpropane and xylene obtained in step 3 respectively, and add them into the reaction kettle; stir and slowly heat to 240° C. under nitrogen protection, and keep reflux for 2.25 hours; in addition to the nitrogen protection, other inert gases or active gases inert to the reaction system can also be used;

[0153] 5. Cool down to 170°C, then weigh methyl nadic anhydride and add it to the reactor, and continue to reflux at 170°C for 1.5h;

[0154] 6. Further cool down to 90°C, then weigh triethylamine and add it into the reaction kettle, and continue stirring at 90°C for 35 minutes to obtain a waterborne acrylic acid modified alkyd resin;

[0155] In steps 4 to 6, the mass ratio of the modified acrylic acid copolymer, ricinoleic acid, 1,4-butanediol, trimethylolpropane, xylene, methyl nadic anhydride, and triethylamine is 25:15:4:10:28:14:4.

[0156] Comparative Example 2:

[0157] A method for preparing a waterborne acrylic acid modified alkyd resin comprises the following steps:

[0158] 1. Weigh acrylic anhydride and xylene, add them into a reactor, and pass nitrogen for 20 minutes; in addition to the nitrogen protection, other inert gases or active gases inert to the reaction system can also be used;

[0159] 2. Raise the temperature to 180°C, then add a mixture of ethyl methacrylate, α-methylstyrene dimer and half the mass of the initiator dibenzoyl peroxide into the reactor under reflux within 2 hours, and keep the mixture under reflux for 0.5 hours;

[0160] 3. Subsequently, the remaining half of the mass of the initiator tert-butyl peroxybenzoate was added, and the mixture was kept at 180° C. for reflux for 1.5 hours to obtain an acrylic acid copolymer product; the mixture was kept at 180° C. for reflux for 2 hours; and the mixture was cooled to 90° C. for discharge to obtain a modified acrylic acid copolymer;

[0161] In steps 1 to 3, the mass ratio of acrylic anhydride, xylene, ethyl methacrylate, α-methylstyrene dimer, half the mass of dibenzoyl peroxide, and the remaining half the mass of dibenzoyl peroxide is 28:35:35:1:0.5:0.5;

[0162] 4. Weigh the modified acrylic acid copolymer, trans-oleic acid, ethylene glycol, trimethylolpropane and xylene obtained in step 3 respectively, and add them into the reaction kettle; stir and slowly heat to 230° C. under nitrogen protection, and keep reflux for 2 hours; in addition to the nitrogen protection, other inert gases or active gases inert to the reaction system can also be used;

[0163] 5. Cool down to 170°C, weigh alkenyl succinic anhydride and add it to the reactor, and continue to reflux at 170°C for 1.5h;

[0164] 6. Further cool down to 85°C, then weigh ammonia water and add it into the reaction kettle, and continue stirring at 85°C for 30 minutes to obtain a water-based acrylic acid modified alkyd resin;

[0165] In steps 4 to 6, the mass ratio of the modified acrylic acid copolymer, trans-oleic acid, ethylene glycol, trimethylolpropane, xylene, alkenyl succinic anhydride, and aqueous ammonia is 20:15:3:5:37:17:3.

[0166] Comparative Example 3:

[0167] A method for preparing a waterborne acrylic acid modified alkyd resin comprises the following steps:

[0168] 1. Weigh acrylic anhydride and xylene, add them into a reactor, and pass nitrogen for 30 minutes; in addition to the nitrogen protection, other inert gases or active gases inert to the reaction system can also be used;

[0169] 2. Raise the temperature to 172°C, then add a mixture of ethyl methacrylate, dodecyl mercaptan and half the mass of the initiator azobisisobutyronitrile dropwise into the reactor within 2.8 hours under reflux, and keep the mixture under reflux for 0.65 hours;

[0170] 3. Subsequently, the remaining half of the mass of the initiator azobisisobutyronitrile was added, and the mixture was kept at 172° C. for reflux for 1.8 hours to obtain an acrylic acid copolymer product; the mixture was kept at 172° C. for reflux for 1.6 hours; and the mixture was cooled to 84° C. for discharge to obtain a modified acrylic acid copolymer;

[0171] In steps 1 to 3, the mass ratio of acrylic anhydride, xylene, ethyl methacrylate, dodecyl mercaptan, half the mass of azobisisobutyronitrile, and the remaining half the mass of azobisisobutyronitrile is 24:33:36:3:2:2;

[0172] 4. Weigh the modified acrylic acid copolymer, palmitic acid, neopentyl glycol, trimethylolpropane and xylene obtained in step 3 respectively, and add them into the reactor; stir and slowly heat to 248° C. under nitrogen protection, and keep reflux for 2.4 hours; in addition to the nitrogen protection, other inert gases or active gases inert to the reaction system can also be used;

[0173] 5. Cool down to 178°C, then weigh methyl nadic anhydride and add it to the reactor, and continue to reflux at 178°C for 1.8 hours;

[0174] 6. Further cool down to 87° C., then weigh potassium hydroxide and add it into the reaction kettle, and continue stirring at 87° C. for 37 minutes to obtain a waterborne acrylic acid modified alkyd resin;

[0175] In steps 4 to 6, the mass ratio of the modified acrylic acid copolymer, palmitoleic acid, neopentyl glycol, trimethylolpropane, xylene, methyl nadic anhydride, and potassium hydroxide is 30:14:5:10:25:11:5.

[0176] Performance Testing:

[0177] The performance of the waterborne acrylic acid modified alkyd resins prepared in Examples 1 to 6 and Comparative Examples 1 to 3 was tested.

[0178] With reference to GB / T 6739-2022, a pencil hardness tester was used to test the hardness of the waterborne acrylic modified alkyd resin coating.

[0179] With reference to GB / T 9274-1988, the immersion method was used to determine the resistance of waterborne acrylic modified alkyd resin coatings.

[0180] With reference to GB / T 1768-2006, the abrasion resistance of waterborne acrylic modified alkyd resin coating was tested by the rotating rubber grinding wheel method.

[0181] Table 1 Performance test results of waterborne acrylic acid modified alkyd resin prepared in Examples and Comparative Examples

[0182]

[0183] As shown in Table 1, the hardness, tolerance and wear resistance of Examples 1 to 6 are better than those of Comparative Examples 1 to 3. This is because the main components of the waterborne acrylic acid modified alkyd resin prepared in the present application include a stable nitrogen-containing five-membered ring structure and a reinforced cross-linked structure formed by the reaction of isocyanate groups and hydroxyl groups, which can improve the hardness, tolerance and wear resistance of the waterborne acrylic acid modified alkyd resin. However, Comparative Examples 1 to 3 have neither a stable nitrogen-containing five-membered ring structure nor a reinforced cross-linked structure formed by the reaction of isocyanate groups and hydroxyl groups, so their hardness, tolerance and wear resistance are poor.

[0184] With reference to GB / T 9286-1998, the cross-cut test method was used to test the adhesion of waterborne acrylic modified alkyd resin coatings.

[0185] Table 2 Adhesion test results of waterborne acrylic acid modified alkyd resin prepared in Examples and Comparative Examples

[0186]

[0187] As shown in Table 2, the adhesion of Examples 1 to 6 is better than that of Comparative Examples 1 to 3. This is because the main components of the waterborne acrylic modified alkyd resin prepared in the present application include a nitrogen-containing five-membered ring structure and an isocyanate group-hydroxyl cross-linking structure. The -NH-COO- structure retained after the reaction of the isocyanate group and the hydroxyl group in the modified acrylic copolymer can further enhance the adhesion of the material. Comparative Examples 1 to 3 do not have the corresponding structure, so their adhesion is poor.

[0188] The above results show and describe the basic principles and main features of the present application as well as the advantages of the present application.

[0189] Those skilled in the art should understand that the present application is not limited by the above embodiments, and the above embodiments and descriptions are only for explaining the principles of the present application. Without departing from the spirit and scope of the present application, the present application may have various changes and improvements, and these changes and improvements fall within the scope of the present application for which protection is sought. The scope of protection sought in the present application is defined by the equivalents of the attached claims.

Claims

1. A water-based acrylic acid modified alkyd resin, characterized in that: The invention comprises at least one chain polymerization structure; the chain polymerization structure comprises a nitrogen-containing five-membered ring structure and an isocyanate group-hydroxyl cross-linking structure; the nitrogen-containing five-membered ring structure is derived from an acrylic acid copolymer obtained by reacting 2-hydroxyethyl acrylate and N-(2-hydroxyethyl) maleimide; the isocyanate group-hydroxyl cross-linking structure is derived from a modified acrylic acid copolymer obtained by modifying the acrylic acid copolymer by diisocyanate; the chain polymerization structure is represented by one or more of the following structures: 、 ， Wherein, R is one or more of the following structures: , , , , and .

2. The water-based acrylic acid modified alkyd resin according to claim 1, characterized in that: The nitrogen-containing five-membered ring structure is represented by the following structure: 。 3. The water-based acrylic acid modified alkyd resin according to claim 1, characterized in that: The isocyanate group-hydroxyl cross-linking structure is represented by one or more of the following structures: 、 ； Wherein, R is one or more of the following structures: , , , , and .

4. A method for preparing a waterborne acrylic acid modified alkyd resin as claimed in any one of claims 1 to 3, characterized in that: The preparation method comprises: Weigh the modified acrylic copolymer, unsaturated fatty acid, diol, trimethylolpropane and xylene respectively, add them into the reaction kettle, stir and heat to 230-250°C under nitrogen protection, and keep reflux for 2-2.5 hours; The temperature was lowered to 160-180°C, and then an organic acid anhydride containing a carbon-carbon double bond was weighed and added to the reaction kettle, and the temperature was kept at 160-180°C for 1-2 hours; The temperature is then lowered to 80-100° C., a neutralizing agent is weighed and added to the reaction kettle, and stirring is continued at 80-100° C. for 30-40 minutes to obtain a waterborne acrylic acid modified alkyd resin; The mass ratio of the modified acrylic copolymer, unsaturated fatty acid, diol, trimethylolpropane, xylene, organic acid anhydride containing carbon-carbon double bonds, and neutralizer is (20-45): (15-20): (3-5): (5-15): (20-30): (10-25): (1.5-6).

5. The method for preparing the waterborne acrylic acid modified alkyd resin according to claim 4, wherein: The unsaturated fatty acids include one or more of oleic acid, trans-oleic acid, palmitoleic acid, ricinoleic acid, linoleic acid, linolenic acid, and arachidonic acid; the diols include one or more of ethylene glycol, propylene glycol, diethylene glycol, 1,4-butanediol, and neopentyl glycol; the organic acid anhydrides containing carbon-carbon double bonds include one or more of alkenyl succinic anhydride, citraconic anhydride, maleic anhydride, and methyl nadic anhydride; and the neutralizer includes one or more of ammonia water, triethylamine, and potassium hydroxide.

6. The method for preparing the waterborne acrylic acid modified alkyd resin according to claim 4, characterized in that: Also includes: preparing the modified acrylic copolymer; The preparation method of the modified acrylic copolymer comprises: Weigh N-(2-hydroxyethyl)maleimide and xylene respectively, add them into the reaction kettle, and pass nitrogen for 20 to 40 minutes; Then, the temperature is raised to 160-180°C, and then, under reflux, a mixture of 2-hydroxyethyl acrylate, a chain transfer agent, and half the mass of the initiator is added dropwise to the reaction kettle within 2-3 hours, and the mixture is kept under reflux for 0.5-1 hour; Then add the remaining half of the mass of the initiator into the reactor, keep the temperature at 160-180°C and reflux for 1.5-2h to obtain the acrylic copolymer product, then weigh the diisocyanate and add it into the reactor, continue to keep the temperature at 160-180°C and reflux for 1-2h; finally cool down to 70-90°C and discharge the material to obtain the modified acrylic copolymer.

7. The method for preparing the waterborne acrylic acid modified alkyd resin according to claim 6, characterized in that: The mass ratio of the N-(2-hydroxyethyl)maleimide, xylene, 2-hydroxyethyl acrylate, chain transfer agent, half the mass of initiator, the remaining half the mass of initiator, and diisocyanate is (15-25): (25-35): (25-50): (1-4): (0.5-3): (0.5-3): (5-15).

8. The method for preparing the waterborne acrylic acid modified alkyd resin according to claim 6, wherein: The chain transfer agent is one or more of α-methylstyrene dimer and dodecyl mercaptan; the initiator is one or more of azobisisobutyronitrile, dibenzoyl peroxide, tert-butyl perbenzoate, and methyl ethyl ketone peroxide; the diisocyanate is one or more of diphenylmethane diisocyanate, hexamethylene diisocyanate, isophorone diisocyanate, naphthalene diisocyanate, p-phenylene diisocyanate, and toluene diisocyanate.

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