Water-based acrylic dispersion resin, preparation method thereof and water-based paint

Abstract

The invention is suitable for the technical field of materials, and provides a water-based acrylic dispersion resin and a preparation method thereof and a water-based paint.The preparation method comprises the steps that after acrylic resin is synthesized, amino resin is added into the acrylic resin, the temperature is controlled to range from 100 DEG C to 120 DEG C, mixing reaction is conducted for 25 min to 40 min, then natural cooling is conducted, and modified resin is obtained; and adding a neutralizer into the modified resin, controlling the temperature to be 100-120 DEG C, carrying out natural cooling and neutralizing treatment, cooling to 100 DEG C or below, and adding water for dispersion, thereby obtaining the product. Wherein the mass ratio of the acrylic resin to the amino resin is (50-96): (4-50). The water-based acrylic dispersion resin obtained in the invention has the characteristics of high gloss, high fullness and high resistance, contains a large number of rigid ring structures, the ring structures contain reactive hydrogen and / or reactive hydroxymethyl groups, and after the water-based acrylic dispersion resin is prepared into paint, the paint is matched with a water-based isocyanate curing agent, so that the paint has remarkable quick-drying performance and self-drying hardness.

Description

Technical Field

[0001] The present application belongs to the field of material technology, and in particular relates to a water-based acrylic dispersion resin and a preparation method thereof, and a water-based coating. Background Art

[0002] At present, water-based acrylic secondary dispersions are widely used in various industrial fields, including engineering machinery, automobiles and buses, equipment shells, etc. Acrylic resins have high gloss, good fullness, good hardness, excellent weather resistance and other properties, especially hydroxyl acrylate resins containing functional groups, which can react with isocyanate curing agents to form water-based two-component polyurethane coatings, and their paint films have more excellent comprehensive properties. However, on the one hand, because the acrylic dispersion resin is synthesized at high temperature, the molecular weight is much smaller than that of acrylic emulsion, resulting in slow drying of the paint film; on the other hand, because the paint film contains some high-boiling point solvents and has a small molecular weight, after being combined with isocyanate curing agents to make two-component polyurethane coatings, the hardness of the paint film is often not high, especially under self-drying conditions, the hardness of the paint film rises more slowly. Although a higher crosslinking density can be achieved by increasing the hydroxyl content to increase the hardness, it usually leads to the use of a large amount of expensive isocyanate curing agents. In practical applications, water-based industrial paints often require sufficient hardness, especially for large workpieces after spraying.

[0003] Therefore, how to ensure that the water-based secondary dispersion has high gloss and high fullness while improving the quick-drying and hardness of the resin is an urgent problem that resin workers need to solve. Summary of the invention

[0004] The purpose of the embodiments of the present application is to provide a water-based acrylic dispersion resin and a preparation method thereof, aiming to solve the technical problems of slow drying and low hardness of the existing water-based acrylic secondary dispersion resin.

[0005] The embodiment of the present application is implemented as follows: a method for preparing an aqueous acrylic dispersion resin comprises:

[0006] After the acrylic resin is synthesized, the amino resin is added to the acrylic resin and the temperature is controlled to be 100-120° C., mixed and reacted for 25-40 minutes and then cooled naturally to obtain a modified resin;

[0007] Adding a neutralizing agent to the modified resin and controlling the temperature to 100-120° C., neutralizing by natural cooling, cooling to between 100° C. and 70° C., and then adding water to disperse the modified resin to obtain a water-based acrylic dispersion resin;

[0008] Wherein, the mass ratio of the acrylic resin to the amino resin is (50-96):(4-50).

[0009] Another object of the present invention is to provide a method for preparing an aqueous acrylic dispersion resin, comprising:

[0010] After the acrylic resin is synthesized, a neutralizing agent is added to the acrylic resin and the temperature is controlled to be 100-120° C., and a natural cooling and neutralization treatment is performed to obtain a hydrophilic resin;

[0011] Adding amino resin to the hydrophilic resin and controlling the temperature to 100-120° C., mixing and reacting for 25-40 minutes, cooling naturally, cooling to between 100° C. and 70° C., and then adding water to disperse, thereby obtaining a water-based acrylic dispersion resin;

[0012] Wherein, the mass ratio of the acrylic resin to the amino resin is (50-96):(4-50).

[0013] Another object of an embodiment of the present application is to provide an aqueous acrylic dispersion resin, wherein the aqueous acrylic dispersion resin is prepared by the above-mentioned method for preparing the aqueous acrylic dispersion resin.

[0014] Another object of an embodiment of the present application is a water-based coating, which includes the above-mentioned water-based acrylic dispersion resin.

[0015] The preparation method of the water-based acrylic dispersion resin provided in the embodiment of the present application innovatively finds that by strictly controlling the system temperature after the synthesis of the acrylic resin and adding a specific amount of amino resin to partially crosslink it with the acrylic secondary dispersion, and then strictly controlling the system temperature to add a neutralizer for neutralization treatment and adding water for dispersion, or by strictly controlling the system temperature after the synthesis of the acrylic resin and then first adding a neutralizer for neutralization treatment, and then strictly controlling the system temperature to add amino resin for crosslinking and then adding water for dispersion, the obtained water-based acrylic dispersion resin has the characteristics of high gloss, high fullness, and high resistance, contains a large number of rigid ring structures and these ring structures themselves contain active hydrogen and / or active hydroxymethyl groups, and after being formulated into paint and matched with a water-based isocyanate curing agent, it has significant quick-drying performance and self-drying hardness. DETAILED DESCRIPTION

[0016] In order to make the purpose, technical solution and advantages of the present application more clear, the present application is further described in detail below in conjunction with the embodiments. It should be understood that the specific embodiments described here are only used to explain the present application and are not used to limit the present application.

[0017] The present application embodiment provides a method for preparing an aqueous acrylic dispersion resin, comprising:

[0018] After the acrylic resin is synthesized, the amino resin is added to the acrylic resin and the temperature is controlled to be 100-120° C., mixed and reacted for 25-40 minutes and then cooled naturally to obtain a modified resin;

[0019] A neutralizing agent is added to the modified resin and the temperature is controlled to be 100-120° C. After natural cooling and neutralization treatment, the temperature is cooled to between 100° C. and 70° C. and then water is added for dispersion to obtain a water-based acrylic dispersion resin.

[0020] In the embodiment of the present application, after the acrylic resin is synthesized, the amino resin is added to the acrylic resin and the temperature is controlled to be 100-120°C. The mixed reaction is naturally cooled within 25-40 minutes. In the step of obtaining the modified resin, the mixing reaction time refers to the period from the beginning of the dropwise addition of the amino resin to the addition of the neutralizing agent. If the reaction time is too long, it is easy to cause excessive cross-linking, which often leads to an increase in molecular weight, difficulty in flow, and is not conducive to further operation. If the reaction time is too short, the cross-linking degree is not enough to achieve the effect. Therefore, the reaction time needs to be strictly controlled to be 25-40 minutes. In addition, a reaction temperature higher than 120°C will cause it to rapidly cross-link and gel, and a temperature lower than 100°C often leads to insufficient cross-linking. Therefore, it is necessary to ensure that the reaction temperature is 100-120°C during the addition of the amino resin to the acrylic resin.

[0021] In an embodiment of the present application, in the step of adding a neutralizing agent to the modified resin and controlling the temperature to 100-120°C, neutralizing by natural cooling, cooling to between below 100°C and 70°C and then adding water for dispersion to obtain an aqueous acrylic dispersion resin, the neutralizing agent may be an amine neutralizing agent, and the present application does not limit its specific type; in the process of adding the neutralizing agent, the temperature of the resin system needs to be controlled to be not less than 100°C, the neutralization treatment time is generally 30 minutes, and the neutralization treatment process is generally a gradual cooling process. When adding water for dispersion, it is necessary to ensure that the system temperature has been cooled to below 100°C. Generally, the temperature can be naturally cooled to below 100°C after 30 minutes of neutralization treatment.

[0022] In addition, the present application also provides another method for preparing an aqueous acrylic dispersion resin, comprising:

[0023] After the acrylic resin is synthesized, a neutralizing agent is added to the acrylic resin and the temperature is controlled to be 100-120° C., and a natural cooling and neutralization treatment is performed to obtain a hydrophilic resin;

[0024] The amino resin is added to the hydrophilic resin and the temperature is controlled at 100-120° C. After mixing and reacting for 25-40 minutes, the temperature is naturally lowered. After the temperature is lowered to between 100° C. and 70° C., water is added for dispersion to obtain a water-based acrylic dispersion resin.

[0025] Compared with the above method, the preparation method of the water-based acrylic dispersion resin first adjusts the temperature and adds a neutralizing agent for neutralization after the acrylic resin is synthesized, then adjusts the temperature and adds an amino resin, and then cools the temperature to below 100°C and adds water for dispersion. Since the temperature of the acrylic resin can be as high as 140°C after synthesis, it is necessary to first lower the temperature to 100-120°C before adding the neutralizing agent or amino resin.

[0026] In the embodiments of the present application, the mass ratio of the acrylic resin to the amino resin is (50-96):(4-50), preferably (85-90):(10-15), and more preferably 90:10.

[0027] In the embodiment of the present application, the synthetic monomers of the acrylic resin include the following monomers in percentage by mass:

[0028] a1 monomer 70-80%, a2 monomer 2-20%, a3 monomer 0-5% and a4 monomer 0.5-5%;

[0029] Among them, the a1 monomer is an ester or vinyl compound or allyl compound generated by an alcohol with 1 to 12 carbon atoms and acrylic acid or methacrylic acid; the a2 monomer is an acrylic acid or methacrylic acid ester containing at least one hydroxyl group; the a3 monomer is an acrylic acid or methacrylic acid ester containing an epoxy group or a keto carbonyl group; the a4 monomer is a carboxylic acid or sulfonic acid monomer containing an acidic functional group that can be neutralized with amines.

[0030] Preferably, the synthetic monomers of the acrylic resin include the following monomers in percentage by mass:

[0031] a1 monomer 75-80%, a2 monomer 10-20%, a3 monomer 2-3% and a4 monomer 2-3%.

[0032] In the embodiment of the present application, except that the synthetic monomers and proportions of acrylic resin are different from those of the prior art, the synthetic process can be implemented with reference to the prior art, such as acrylic resin can be obtained by controlling the temperature to 135-155°C under the action of an organic solvent, adding a1 monomer, a2 monomer, a3 monomer, a4 monomer and initiator to the organic solvent for reaction; the specific operation can be: organic solvent primer, raising the reaction temperature to between 135-155°C, accurately weighing part of the mixed monomers, dripping them in 3-5 hours; then adding initiator and keeping warm for 0.5-1 hour; dripping the remaining part of the mixed monomers, taking 1-2.5 hours, then adding initiator and keeping warm for 1-2 hours to obtain acrylic resin. In addition, in order to adjust the molecular weight more uniformly, a chain transfer agent can also be added to the synthetic system of acrylic resin.

[0033] Optionally, the organic solvent is one or more of trimethylbenzene, solvent naphtha, diethylene glycol butyl ether, dipropylene glycol butyl ether, dipropylene glycol methyl ether, n-butanol, ethylene glycol monobutyl ether, propylene glycol butyl ether, propylene glycol methyl ether, isopropanol and sec-butanol.

[0034] Optionally, the initiator is one or more of benzoic acid peroxide, tert-butyl perbenzoate, di-tert-butyl peroxide, di-tert-amyl peroxide, tert-butyl peroxy-2-ethylhexanoate, tert-amyl peroxy-2-ethylhexanoate, and di-tert-amyl peroxide.

[0035] Optionally, the a1 monomer is one or more of styrene, allyltrimethoxysilane, allyltriethoxysilane, acrylonitrile, methyl acrylate, methyl methacrylate, butyl acrylate, butyl methacrylate, isobornyl acrylate, isobornyl methacrylate, ethyl acrylate, ethyl methacrylate, cyclohexyl acrylate, cyclohexyl methacrylate, isooctyl acrylate, isooctyl methacrylate, and tert-butyl methacrylate.

[0036] Optionally, the a2 monomer is one or more of hydroxyethyl acrylate, hydroxyethyl methacrylate, hydroxypropyl acrylate, hydroxypropyl methacrylate, hydroxybutyl acrylate, hydroxybutyl methacrylate, and polyethylene glycol acrylate.

[0037] Optionally, the a3 monomer is one or more of diacetone acrylamide, acetoxyethyl acrylate, acetoxyethyl methacrylate, glycidyl acrylate, and glycidyl methacrylate.

[0038] Optionally, the a4 monomer is one or more of acrylic acid, methacrylic acid, itaconic acid, and sulfonyl styrene, preferably acrylic acid.

[0039] Optionally, the amino resin is one or more of highly methylated melamine resin, highly imino methylated melamine resin, partially methylated melamine resin, benzoguanamine resin, high solid content urea-formaldehyde resin, unalkylated methoxylated glycoluril resin and highly alkylated glycoluril resin.

[0040] Specifically, the amino resin can be a highly methylated melamine resin or a highly imino methylated melamine resin or a partially methylated melamine resin produced by Cytec, INEOS or other manufacturers, such as CYMEL 300, CYMEL 303LF, CYMEL 308, CYMEL 350, CYMEL 323, CYMEL 325, CYMEL 327, CYMEL 385, CYMEL 370, CYMEL 373, CYMEL 380, Resimene 717, MAPRENAL MF927, Resimene CE-7103, Resimene R750, Resimene 747, etc. Furthermore, the amino resin may also be a benzoguanamine resin such as CYMEL 659, CYMEL 1123, CYMEL 5010, ETERMINO 9411-75, ETERMINO 94112-75, ETERMINO 9412-70, etc. Furthermore, the amino resin may also be a high solid content urea-formaldehyde resin including methyl etherified urea-formaldehyde resin and butyl etherified urea-formaldehyde resin, such as CYMELU-65, CYMELUM-15, CYMELU-80, etc.; it may also be an unalkylated methoxylated glycoluril resin and a highly alkylated glycoluril resin, such as CYMEL 1170, CYMEL 1172, etc. The amino resins mentioned above are preferably high imino methyl etherified melamine resin or partially methyl etherified melamine resin, unalkylated methoxylated glycoluril resin, urea-formaldehyde resin, etc.

[0041] The embodiment of the present application further provides an aqueous acrylic dispersion resin, wherein the aqueous acrylic dispersion resin is prepared by the above-mentioned method for preparing the aqueous acrylic dispersion resin.

[0042] Furthermore, the present application also provides a water-based coating, which includes the above-mentioned water-based acrylic dispersion resin. For example, a wetting agent, a defoaming agent, a leveling agent, a pH regulator, a thickener, a color paste, etc. are added to the above-mentioned water-based acrylic dispersion resin to prepare a water-based coating. Although the specific embodiment only describes one of the coating formulas, those skilled in the art can select the types of solvents and additives in the formula according to actual needs, and the scope of the present application should not be limited by this.

[0043] The aqueous acrylic dispersion resin and its preparation method are described in detail with specific examples as follows. The experimental methods used in the following examples are conventional methods unless otherwise specified; the materials and reagents used are all commercially available unless otherwise specified.

[0044] Example 1: Preparation of waterborne acrylic dispersion resin

[0045] Add 100g of No. 100 solvent oil and 100g of ethylene glycol butyl ether into the reaction bottle, stir and heat to 140-148°C, while introducing nitrogen to exhaust the air in the bottle, maintain the temperature range, and prepare to dropwise add acrylic acid monomer and initiator;

[0046] 350g of methyl methacrylate, 250g of styrene, 125g of hydroxyethyl methacrylate, 550g of n-butyl methacrylate and 1g of n-dodecyl mercaptan were mixed evenly and poured into a dropping funnel; 25g of tert-butyl peroxide, 25g of No. 100 solvent oil and 25g of ethylene glycol butyl ether were mixed evenly and loaded into another dropping funnel; first, one-fifth of the initiator mixture was added to the bottle, and then the monomer and initiator funnels were simultaneously added with the materials, and the materials were added synchronously after 4-5h, and then 5g of tert-butyl peroxide was added and kept warm for one hour; then 125g of methyl methacrylate, 75g of hydroxyethyl methacrylate, 50g of acrylic acid and 100g of n-butyl methacrylate were mixed evenly and loaded into a dropping funnel; 9g of tert-butyl peroxide, 25g of No. 100 solvent oil and 25g of ethylene glycol butyl ether were mixed evenly and loaded into another dropping funnel; two dropping funnels were simultaneously added and the addition was completed within 2-3h, and then 3g of tert-butyl peroxide was added and kept warm for 1h, and then 3g of tert-butyl peroxide was added and kept warm for 1h, and then 150g of amino resin CYMEL 327 was added when the temperature dropped to 120°C and the addition was completed within 10 minutes, and amine was added for neutralization when the temperature dropped naturally within 25 minutes (the temperature when adding amine was 110°C), and the temperature was cooled to 95°C after stirring for 30 minutes, and water was added for dispersion, and the temperature was cooled to below 40°C to obtain a water-based acrylic dispersion resin.

[0047] Example 2: Preparation of waterborne acrylic dispersion resin

[0048] Add 100g of No. 100 solvent oil and 100g of ethylene glycol butyl ether into the reaction bottle, stir and heat to 140-148°C, while introducing nitrogen to exhaust the air in the bottle, maintain the temperature range, and prepare to dropwise add acrylic acid monomer and initiator;

[0049] 350g of methyl methacrylate, 250g of styrene, 125g of hydroxyethyl methacrylate, 550g of n-butyl methacrylate and 1g of n-dodecyl mercaptan were mixed evenly and poured into a dropping funnel; 25g of tert-butyl peroxide, 25g of No. 100 solvent oil and 25g of ethylene glycol butyl ether were mixed evenly and loaded into another dropping funnel; first, one-fifth of the initiator mixture was added to the bottle, and then the monomer and initiator funnels were simultaneously added with the materials, and the materials were added synchronously after 4-5h, and then 5g of tert-butyl peroxide was added and kept warm for one hour; then 125g of methyl methacrylate, 75g of hydroxyethyl methacrylate, 50g of acrylic acid and 100g of n-butyl methacrylate were mixed evenly and loaded into a dropping funnel; 9g of tert-butyl peroxide, 25g of No. 100 solvent oil and 25g of ethylene glycol butyl ether were mixed evenly and loaded into another dropping funnel; two dropping funnels were simultaneously added and the addition was completed within 2-3h, and then 3g of tert-butyl peroxide was added and kept warm for 1h, and then 3g of tert-butyl peroxide was added and kept warm for 1h, and then 150g of amino resin CYMEL 327 was added when the temperature dropped to 110°C and the addition was completed within 10 minutes, and amine was added for neutralization when the temperature dropped naturally within 25 minutes (the temperature when adding amine was 105°C), and the temperature was cooled to 95°C after stirring for 30 minutes, and water was added for dispersion, and the temperature was cooled to below 40°C to obtain a water-based acrylic dispersion resin.

[0050] Example 3: Preparation of waterborne acrylic dispersion resin

[0051] Add 100g of No. 100 solvent oil and 100g of ethylene glycol butyl ether into the reaction bottle, stir and heat to 140-148°C, while introducing nitrogen to exhaust the air in the bottle, maintain the temperature range, and prepare to dropwise add acrylic acid monomer and initiator;

[0052] 350g of methyl methacrylate, 250g of styrene, 125g of hydroxyethyl methacrylate, 550g of n-butyl methacrylate and 1g of n-dodecyl mercaptan were mixed evenly and poured into a dropping funnel; 25g of tert-butyl peroxide, 25g of No. 100 solvent oil and 25g of ethylene glycol butyl ether were mixed evenly and loaded into another dropping funnel; first, one-fifth of the initiator mixture was added to the bottle, and then the monomer and initiator funnels were simultaneously added with the materials, and the materials were added synchronously after 4-5h, and then 5g of tert-butyl peroxide was added and kept warm for one hour; then 125g of methyl methacrylate, 75g of hydroxyethyl methacrylate, 50g of acrylic acid and 100g of n-butyl methacrylate were mixed evenly and loaded into a dropping funnel; 9g of tert-butyl peroxide, 25g of No. 100 solvent oil and 25g of ethylene glycol butyl ether were mixed evenly and loaded into another dropping funnel; two dropping funnels were simultaneously added and the addition was completed within 2-3h, and then 3g of tert-butyl peroxide was added and kept warm for 1h, and then 3g of tert-butyl peroxide was added and kept warm for 1h. When the temperature dropped to 110°C, 300g of amino resin CYMEL 327 was added and the addition was completed within 10 minutes. The temperature was naturally lowered within 25 minutes and amine was added for neutralization (the temperature when adding amine was 105°C). After stirring for 30 minutes, the temperature was lowered to 95°C and water was added for dispersion. The temperature was lowered to below 40°C and the material was discharged to obtain a water-based acrylic dispersion resin.

[0053] Example 4: Preparation of waterborne acrylic dispersion resin

[0054] Add 100g of No. 100 solvent oil and 100g of ethylene glycol butyl ether into the reaction bottle, stir and heat to 140-148°C, while introducing nitrogen to exhaust the air in the bottle, maintain the temperature range, and prepare to dropwise add acrylic acid monomer and initiator;

[0055] Mix 350g of methyl methacrylate, 250g of styrene, 125g of hydroxyethyl methacrylate, 550g of n-butyl methacrylate, 50g of acetoethoxy methacrylate, and 1g of n-dodecyl mercaptan, and pour them into a dropping funnel; mix 25g of tert-butyl peroxide, 25g of No. 100 solvent oil, and 25g of ethylene glycol butyl ether, and put them into another dropping funnel; first add one-fifth of the initiator mixture into the bottle, then start dripping the materials into the monomer and initiator funnels at the same time, and finish dripping them synchronously after 4-5h, and then add 5g of tert-butyl peroxide, Keep warm for one hour; then mix 125g of methyl methacrylate, 75g of hydroxyethyl methacrylate, 50g of acrylic acid, and 100g of n-butyl methacrylate, and evenly put them into a dropping funnel; mix 9g of tert-butyl peroxide, 25g of No. 100 solvent oil, and 25g of ethylene glycol butyl ether, and evenly put them into another dropping funnel; start dropping from the two dropping funnels at the same time, and add them within 2-3h, then add 3g of tert-butyl peroxide, keep warm for 1h, and then add 3g of tert-butyl peroxide and keep warm for 1h, and start dropping 150g of amino resin CYMEL 327 when the temperature drops to 110°C, and drop them within 10 minutes, and naturally cool down within 25 minutes and start adding amine for neutralization (the temperature when adding amine is 105°C), stir for 30 minutes, cool down to 95°C, add water for dispersion, and cool down to below 40°C to obtain a water-based acrylic dispersion resin.

[0056] Example 5: Preparation of waterborne acrylic dispersion resin

[0057] Add 100g of No. 100 solvent oil and 100g of ethylene glycol butyl ether into the reaction bottle, stir and heat to 140-148°C, while introducing nitrogen to exhaust the air in the bottle, maintain the temperature range, and prepare to dropwise add acrylic acid monomer and initiator;

[0058] 350g of methyl methacrylate, 250g of styrene, 125g of hydroxyethyl methacrylate, 550g of n-butyl methacrylate and 1g of n-dodecyl mercaptan were mixed evenly and poured into a dropping funnel; 25g of tert-butyl peroxide, 25g of No. 100 solvent oil and 25g of ethylene glycol butyl ether were mixed evenly and loaded into another dropping funnel; first, one-fifth of the initiator mixture was added to the bottle, and then the monomer and initiator funnels were simultaneously added with the materials, and the materials were simultaneously added after 4-5h, and then 5g of tert-butyl peroxide was added and kept warm for one hour; then 100g of methyl methacrylate was added to the bottle, and then the monomer and initiator funnels were added with the materials at the same time, and the materials were added simultaneously after 4-5h, and then 5g of tert-butyl peroxide was added and kept warm for one hour; then 100g of methyl methacrylate was added to the bottle, and then 100g of hydroxyethyl ... 25g, 75g hydroxyethyl methacrylate, 50g acrylic acid, 100g n-butyl methacrylate are mixed evenly and loaded into a dropping funnel; 9g tert-butyl peroxide, 25g No. 100 solvent oil, and 25g ethylene glycol butyl ether are mixed evenly and loaded into another dropping funnel; two dropping funnels are started to drop at the same time, and the addition is completed within 2-3h, and then 3g tert-butyl peroxide is added, and the temperature is kept for 1h, and then 3g tert-butyl peroxide is added and the temperature is kept for 1h, and then 3g tert-butyl peroxide is added and the temperature is kept for 1h, and then amine is added at 110℃ and stirred for 30 minutes, and then 150g amino resin CYMEL 327 is started to be added dropwise when the temperature is kept at 105℃, and the addition is completed within 10 minutes and the temperature is kept for 25 minutes, and the temperature is cooled to 95℃, water is added to disperse, and the temperature is cooled to below 40℃ to discharge the material to obtain a water-based acrylic dispersion resin.

[0059] Example 6: Preparation of waterborne acrylic dispersion resin

[0060] Add 100g of No. 100 solvent oil and 100g of ethylene glycol butyl ether into the reaction bottle, stir and heat to 140-148°C, while introducing nitrogen to exhaust the air in the bottle, maintain the temperature range, and prepare to dropwise add acrylic acid monomer and initiator;

[0061] 350g of methyl methacrylate, 250g of styrene, 125g of hydroxyethyl methacrylate, 550g of n-butyl methacrylate and 1g of n-dodecyl mercaptan were mixed evenly and poured into a dropping funnel; 25g of tert-butyl peroxide, 25g of No. 100 solvent oil and 25g of ethylene glycol butyl ether were mixed evenly and loaded into another dropping funnel; first, one-fifth of the initiator mixture was added to the bottle, and then the monomer and initiator funnels were simultaneously added with the materials, and the materials were added synchronously after 4-5h, and then 5g of tert-butyl peroxide was added and kept warm for one hour; then 125g of methyl methacrylate, 75g of hydroxyethyl methacrylate, 50g of acrylic acid and 100g of n-butyl methacrylate were mixed evenly and loaded into a dropping funnel; 9g of tert-butyl peroxide, 25g of No. 100 solvent oil and 25g of ethylene glycol butyl ether were mixed evenly and loaded into another dropping funnel; two dropping funnels were simultaneously added and the addition was completed within 2-3h, and then 3g of tert-butyl peroxide was added and kept warm for 1h, and then 3g of tert-butyl peroxide was added and kept warm for 1h, and then 150g of amino resin CYMEL 327 was added when the temperature dropped to 110°C and the addition was completed within 10 minutes, and amine was added for neutralization when the temperature dropped naturally within 15 minutes (the temperature when adding amine was 105°C), and the temperature was cooled to 95°C after stirring for 30 minutes, and water was added for dispersion, and the temperature was cooled to below 40°C to obtain a water-based acrylic dispersion resin.

[0062] Example 7: Preparation of waterborne acrylic dispersion resin

[0063] Add 100g of No. 100 solvent oil and 100g of ethylene glycol butyl ether into the reaction bottle, stir and heat to 140-148°C, while introducing nitrogen to exhaust the air in the bottle, maintain the temperature range, and prepare to dropwise add acrylic acid monomer and initiator;

[0064] 350g of methyl methacrylate, 250g of styrene, 125g of hydroxyethyl methacrylate, 550g of n-butyl methacrylate and 1g of n-dodecyl mercaptan were mixed evenly and poured into a dropping funnel; 25g of tert-butyl peroxide, 25g of No. 100 solvent oil and 25g of ethylene glycol butyl ether were mixed evenly and loaded into another dropping funnel; first, one-fifth of the initiator mixture was added to the bottle, and then the monomer and initiator funnels were simultaneously added with the materials, and the materials were added synchronously after 4-5h, and then 5g of tert-butyl peroxide was added and kept warm for one hour; then 125g of methyl methacrylate, 75g of hydroxyethyl methacrylate, 50g of acrylic acid and 100g of n-butyl methacrylate were mixed evenly and loaded into a dropping funnel; 9g of tert-butyl peroxide, 25g of No. 100 solvent oil and 25g of ethylene glycol butyl ether were mixed evenly and loaded into another dropping funnel; two dropping funnels were simultaneously added and the addition was completed within 2-3h, and then 3g of tert-butyl peroxide was added and kept warm for 1h, and then 3g of tert-butyl peroxide was added and kept warm for 1h, and then 150g of amino resin CYMEL 327 and CYMEL 303 (mass ratio was 1:1) was added when the temperature dropped to 110°C, and the addition was completed within 10 minutes, and amine was added for neutralization after natural cooling within 25 minutes (the temperature when amine was added was 105°C), and the temperature was cooled to 95°C after stirring for 30 minutes, and water was added for dispersion, and the temperature was cooled to below 40°C to obtain a water-based acrylic dispersion resin.

[0065] Example 8: Preparation of waterborne acrylic dispersion resin

[0066] Add 100g of No. 100 solvent oil and 100g of ethylene glycol butyl ether into the reaction bottle, stir and heat to 140-148°C, while introducing nitrogen to exhaust the air in the bottle, maintain the temperature range, and prepare to dropwise add acrylic acid monomer and initiator;

[0067] Mix 541g of methyl methacrylate, 64g of styrene, 544g of n-butyl methacrylate, 126g of hydroxypropyl methacrylate and 1g of n-dodecyl mercaptan evenly and pour into a dropping funnel; mix 25g of tert-butyl peroxide, 25g of No. 100 solvent oil and 25g of ethylene glycol butyl ether evenly and put them into another dropping funnel; first add one-fifth of the initiator mixture into the bottle, then start adding materials to the monomer and initiator funnels at the same time, and finish dropping them synchronously after 4-5h, then add 5g of tert-butyl peroxide and keep warm for one hour; then 93g of methyl methacrylate, 65g of acrylic acid, 112g of n-butyl methacrylate, and 80g of hydroxypropyl methacrylate are mixed evenly and loaded into a dropping funnel; 9g of tert-butyl peroxide, 25g of No. 100 solvent oil, and 25g of ethylene glycol butyl ether are mixed evenly and loaded into another dropping funnel; two dropping funnels are started to drop at the same time and the addition is completed within 2-3h, then 3g of tert-butyl peroxide is added and kept warm for 1h, and then 3g of tert-butyl peroxide is added and kept warm for 1h. When the temperature drops to 105°C, 150g of amino resin CYMEL 303 is started to be added dropwise and the addition is completed within 10 minutes. The temperature is naturally lowered within 25 minutes and amine is added for neutralization (the temperature when adding amine is 100°C). After stirring for 30 minutes, the temperature is lowered to 95°C and water is added for dispersion. The temperature is lowered to below 40°C and the material is discharged to obtain a water-based acrylic dispersion resin.

[0068] Example 9: Preparation of waterborne acrylic dispersion resin

[0069] Add 100g of No. 100 solvent oil and 100g of ethylene glycol butyl ether into the reaction bottle, stir and heat to 140-148°C, while introducing nitrogen to exhaust the air in the bottle, maintain the temperature range, and prepare to dropwise add acrylic acid monomer and initiator;

[0070] 321g of methyl methacrylate, 64g of styrene, 140g of hydroxyethyl methacrylate, 406g of isobornyl methacrylate, 294g of n-butyl methacrylate, 50g of acetoethoxy methacrylate and 1g of n-dodecyl mercaptan were mixed evenly and poured into a dropping funnel; 25g of tert-butyl peroxide, 25g of No. 100 solvent oil and 25g of ethylene glycol butyl ether were mixed evenly and loaded into another dropping funnel; first, one-fifth of the initiator mixture was added to the bottle, and then the monomer and initiator funnels were simultaneously added with the materials, and the materials were simultaneously added after 4-5h, and then 5g of tert-butyl peroxide was added and kept warm for one hour; then 103g of methyl methacrylate, 60g of hydroxyethyl methacrylate and methacrylate were added; 55g of isobornyl ester and 132g of n-butyl acrylate are mixed evenly and loaded into a dropping funnel; 9g of tert-butyl peroxide, 25g of No. 100 solvent oil and 25g of ethylene glycol butyl ether are mixed evenly and loaded into another dropping funnel; two dropping funnels are started to drop at the same time and the addition is completed within 2-3h, then 3g of tert-butyl peroxide is added and kept warm for 1h, and then 3g of tert-butyl peroxide is added and kept warm for 1h. When the temperature drops to 105°C, 200g of amino resin CYMEL327 is started to be added dropwise and the addition is completed within 5 minutes. The temperature is naturally lowered within 35 minutes and amine is added for neutralization (the temperature when adding amine is 100°C). After stirring for 30 minutes, the temperature is lowered to 95°C and water is added for dispersion. The temperature is lowered to below 40°C and the material is discharged to obtain a water-based acrylic dispersion resin.

[0071] Comparative Example 1: Preparation of unmodified acrylic dispersion resin

[0072] Add 100g of No. 100 solvent oil and 100g of ethylene glycol butyl ether into the reaction bottle, stir and heat to 140-148°C, while introducing nitrogen to exhaust the air in the bottle, maintain the temperature range, and prepare to dropwise add acrylic acid monomer and initiator;

[0073] 350g of methyl methacrylate, 250g of styrene, 125g of hydroxyethyl methacrylate, 550g of n-butyl methacrylate and 1g of n-dodecyl mercaptan were mixed evenly and poured into a dropping funnel; 25g of tert-butyl peroxide, 25g of No. 100 solvent oil and 25g of ethylene glycol butyl ether were mixed evenly and loaded into another dropping funnel; first, one-fifth of the initiator mixture was added to the bottle, and then the monomer and initiator funnels were simultaneously added with the materials, and the materials were simultaneously added after 4-5h, and then 5g of tert-butyl peroxide was added and kept warm for one hour; then 125g of methyl methacrylate, methyl acrylate and 125g of hydroxyethyl methacrylate were added, and the mixture was stirred for 1 hour. Mix 75g of hydroxyethyl acrylate, 50g of acrylic acid and 100g of n-butyl methacrylate evenly and put them into a dropping funnel; mix 9g of tert-butyl peroxide, 25g of No. 100 solvent oil and 25g of ethylene glycol butyl ether evenly and put them into another dropping funnel; start adding dropwise with two dropping funnels at the same time and finish adding within 2-3h, then add 3g of tert-butyl peroxide and keep warm for 1h, then add 3g of tert-butyl peroxide and keep warm for 1h, cool to 105℃ and start adding amine for neutralization, stir for 30 minutes, cool to 95℃, add water for dispersion, cool to below 40℃ and discharge to obtain unmodified acrylic dispersion resin.

[0074] Comparative Example 2: Preparation of waterborne acrylic dispersion resin

[0075] Add 100g of No. 100 solvent oil and 100g of ethylene glycol butyl ether into the reaction bottle, stir and heat to 140-148°C, while introducing nitrogen to exhaust the air in the bottle, maintain the temperature range, and prepare to dropwise add acrylic acid monomer and initiator;

[0076] 350g of methyl methacrylate, 250g of styrene, 125g of hydroxyethyl methacrylate, 550g of n-butyl methacrylate and 1g of n-dodecyl mercaptan were mixed evenly and poured into a dropping funnel; 25g of tert-butyl peroxide, 25g of No. 100 solvent oil and 25g of ethylene glycol butyl ether were mixed evenly and loaded into another dropping funnel; first, one-fifth of the initiator mixture was added to the bottle, and then the monomer and initiator funnels were simultaneously added with the materials, and the materials were added synchronously after 4-5h, and then 5g of tert-butyl peroxide was added and kept warm for one hour; then 125g of methyl methacrylate, 75g of hydroxyethyl methacrylate, 50g of acrylic acid and 100g of n-butyl methacrylate were mixed evenly and loaded into a dropping funnel; 9g of tert-butyl peroxide, 25g of No. 100 solvent oil and 25g of ethylene glycol butyl ether were mixed evenly and loaded into another dropping funnel; two dropping funnels were simultaneously added and the addition was completed within 2-3 hours, and then 3g of tert-butyl peroxide was added and kept warm for 1 hour, and then 3g of tert-butyl peroxide was added and kept warm for 1 hour, and 40g of amino resin CYMEL 327 was added when the temperature dropped to 110°C and the addition was completed within 10 minutes, and amine was added for neutralization when the temperature dropped naturally within 25 minutes (the temperature when the amine was added was 105°C), and the temperature was cooled to 95°C after stirring for 30 minutes, and water was added for dispersion, and the temperature was cooled to below 40°C to obtain a water-based acrylic dispersion resin.

[0077] Comparative Example 3: Preparation of waterborne acrylic dispersion resin

[0078] Add 100g of No. 100 solvent oil and 100g of ethylene glycol butyl ether into the reaction bottle, stir and heat to 140-148°C, while introducing nitrogen to exhaust the air in the bottle, maintain the temperature range, and prepare to dropwise add acrylic acid monomer and initiator;

[0079] 350g of methyl methacrylate, 250g of styrene, 125g of hydroxyethyl methacrylate, 550g of n-butyl methacrylate and 1g of n-dodecyl mercaptan were mixed evenly and poured into a dropping funnel; 25g of tert-butyl peroxide, 25g of No. 100 solvent oil and 25g of ethylene glycol butyl ether were mixed evenly and loaded into another dropping funnel; first, one-fifth of the initiator mixture was added to the bottle, and then the monomer and initiator funnels were simultaneously added with the materials, and the materials were added synchronously after 4-5h, and then 5g of tert-butyl peroxide was added and kept warm for one hour; Then, 125 g of methyl methacrylate, 75 g of hydroxyethyl methacrylate, 50 g of acrylic acid, and 100 g of n-butyl methacrylate were mixed evenly and loaded into a dropping funnel; 9 g of tert-butyl peroxide, 25 g of No. 100 solvent oil, and 25 g of ethylene glycol butyl ether were mixed evenly and loaded into another dropping funnel; two dropping funnels were started to add dropwise at the same time and the addition was completed within 2-3 hours, and then 3 g of tert-butyl peroxide was added and kept warm for 1 hour, and then 3 g of tert-butyl peroxide was added and kept warm for 1 hour. At 140°C, 150 g of amino resin CYMEL 327 was started to be added dropwise, and the resin was gelled after about 10 minutes.

[0080] Comparative Example 4: Preparation of waterborne acrylic dispersion resin

[0081] Add 100g of No. 100 solvent oil and 100g of ethylene glycol butyl ether into the reaction bottle, stir and heat to 140-148°C, while introducing nitrogen to exhaust the air in the bottle, maintain the temperature range, and prepare to dropwise add acrylic acid monomer and initiator;

[0082] 350g of methyl methacrylate, 250g of styrene, 125g of hydroxyethyl methacrylate, 550g of n-butyl methacrylate and 1g of n-dodecyl mercaptan were mixed evenly and poured into a dropping funnel; 25g of tert-butyl peroxide, 25g of No. 100 solvent oil and 25g of ethylene glycol butyl ether were mixed evenly and loaded into another dropping funnel; first, one-fifth of the initiator mixture was added to the bottle, and then the monomer and initiator funnels were simultaneously added with the materials, and the materials were added synchronously after 4-5h, and then 5g of tert-butyl peroxide was added and kept warm for one hour; then Mix 125g of methyl methacrylate, 75g of hydroxyethyl methacrylate, 50g of acrylic acid, and 100g of n-butyl methacrylate evenly and put them into a dropping funnel; mix 9g of tert-butyl peroxide, 25g of No. 100 solvent oil, and 25g of ethylene glycol butyl ether evenly and put them into another dropping funnel; start dropping into the two dropping funnels at the same time and finish the addition within 2-3 hours, then add 3g of tert-butyl peroxide and keep warm for 1 hour, then add 3g of tert-butyl peroxide and keep warm for 1 hour, and start dropping 150g of amino resin CYMEL 327 when the temperature drops to 95°C, finish the addition within 10 minutes, and start adding amine for neutralization after stirring for 25 minutes, and after stirring for 30 minutes, cool to 95°C, add water for dispersion, and cool to below 40°C to obtain a water-based acrylic dispersion resin.

[0083] Comparative Example 5: Preparation of waterborne acrylic dispersion resin

[0084] Add 100g of No. 100 solvent oil and 100g of ethylene glycol butyl ether into the reaction bottle, stir and heat to 140-148°C, while introducing nitrogen to exhaust the air in the bottle, maintain the temperature range, and prepare to dropwise add acrylic acid monomer and initiator;

[0085] 350g of methyl methacrylate, 250g of styrene, 125g of hydroxyethyl methacrylate, 550g of n-butyl methacrylate and 1g of n-dodecyl mercaptan were mixed evenly and poured into a dropping funnel; 25g of tert-butyl peroxide, 25g of No. 100 solvent oil and 25g of ethylene glycol butyl ether were mixed evenly and loaded into another dropping funnel; first, one-fifth of the initiator mixture was added to the bottle, and then the monomer and initiator funnels were simultaneously added with the materials, and the materials were added synchronously after 4-5h, and then 5g of tert-butyl peroxide was added and kept warm for one hour; then 125g of methyl methacrylate, 75g of hydroxyethyl methacrylate, 50g of acrylic acid and 100g of n-butyl methacrylate were mixed evenly and loaded into a dropping funnel; 9g of tert-butyl peroxide, 25g of No. 100 solvent oil and 25g of ethylene glycol butyl ether were mixed evenly and loaded into another dropping funnel; two dropping funnels were started to add at the same time and the addition was completed within 2-3h, then 3g of tert-butyl peroxide was added and kept warm for 1h, and then 3g of tert-butyl peroxide was added and kept warm for 1h. When the temperature dropped to 110℃, 150g of amino resin CYMEL 327 was started to be added and the addition was completed within 10 minutes. After stirring for 70min, the resin had high viscosity and was difficult to disperse.

[0086] Comparative Example 6: Preparation of waterborne acrylic dispersion resin

[0087] Add 100g of No. 100 solvent oil and 100g of ethylene glycol butyl ether into the reaction bottle, stir and heat to 140-148°C, while introducing nitrogen to exhaust the air in the bottle, maintain the temperature range, and prepare to dropwise add acrylic acid monomer and initiator;

[0088] 350g of methyl methacrylate, 250g of styrene, 125g of hydroxyethyl methacrylate, 550g of n-butyl methacrylate and 1g of n-dodecyl mercaptan were mixed evenly and poured into a dropping funnel; 25g of tert-butyl peroxide, 25g of No. 100 solvent oil and 25g of ethylene glycol butyl ether were mixed evenly and loaded into another dropping funnel; first, one-fifth of the initiator mixture was added to the bottle, and then the monomer and initiator funnels were simultaneously added with the materials, and the materials were simultaneously added after 4-5h, and then 5g of tert-butyl peroxide was added and kept warm for one hour; then 125g of methyl methacrylate, methyl 75g of hydroxyethyl acrylate, 50g of acrylic acid, and 100g of n-butyl methacrylate are mixed evenly and loaded into a dropping funnel; 9g of tert-butyl peroxide, 25g of No. 100 solvent oil, and 25g of ethylene glycol butyl ether are mixed evenly and loaded into another dropping funnel; two dropping funnels are started to drop at the same time and the addition is completed within 2-3 hours, then 3g of tert-butyl peroxide is added and kept warm for 1 hour, and then 3g of tert-butyl peroxide is added and kept warm for 1 hour, and then amine is added for neutralization when the temperature drops to 105°C, and after stirring for 30 minutes, the temperature is lowered to 95°C, and water is added for dispersion, and 150g of amino resin CYMEL 327 is added dropwise at 80°C, and the addition is completed within 10 minutes, and the temperature is lowered to below 40°C to obtain a water-based acrylic dispersion resin.

[0089] Comparative Example 7: Preparation of waterborne acrylic dispersion resin

[0090] Add 100g of No. 100 solvent oil and 100g of ethylene glycol butyl ether into the reaction bottle, stir and heat to 140-148°C, while introducing nitrogen to exhaust the air in the bottle, maintain the temperature range, and prepare to dropwise add acrylic acid monomer and initiator;

[0091] 350g of methyl methacrylate, 250g of styrene, 125g of hydroxyethyl methacrylate, 550g of n-butyl methacrylate and 1g of n-dodecyl mercaptan were mixed evenly and poured into a dropping funnel; 25g of tert-butyl peroxide, 25g of No. 100 solvent oil and 25g of ethylene glycol butyl ether were mixed evenly and loaded into another dropping funnel; first, one-fifth of the initiator mixture was added to the bottle, and then the monomer and initiator funnels were simultaneously added with the materials, and the materials were added synchronously after 4-5h, and then 5g of tert-butyl peroxide was added and kept warm for one hour; then Mix 125g of methyl methacrylate, 75g of hydroxyethyl methacrylate, 50g of acrylic acid and 100g of n-butyl methacrylate evenly and put them into a dropping funnel; mix 9g of tert-butyl peroxide, 25g of No. 100 solvent oil and 25g of ethylene glycol butyl ether evenly and put them into another dropping funnel; start dropping into the two dropping funnels at the same time and finish the addition within 2-3 hours, then add 3g of tert-butyl peroxide and keep warm for 1 hour, then add 3g of tert-butyl peroxide and keep warm for 1 hour, add 150g of amino resin CYMEL 327 when the temperature drops to 110°C, cool to 105°C within 6 minutes and start adding amine for neutralization, cool to 95°C while stirring within 30 minutes, add water for dispersion, cool to below 40°C and discharge to obtain water-based acrylic dispersion resin.

[0092] The acrylic dispersion resin prepared in the above Examples 1-9 and Comparative Examples 1-2, 4, 6-7 was used for paint preparation. The specific formula was as follows: by mass percentage, 63% acrylic dispersion resin, 0.3% wetting defoamer AD-01, 2.5% diethylene glycol butyl ether DBG, 2.1% dipropylene glycol butyl ether DPNB, 1.6% deionized water, 0.5% wetting agent Tego-4100, 0.4% flash rust inhibitor FA-179, 29.4% titanium dioxide slurry with a mass fraction of 75%, and 0.2% thickener XS-71; wherein, the preparation formula of the titanium dioxide slurry with a mass fraction of 75% was as follows: by mass percentage, 16.8% deionized water, 3% propylene glycol PG, 0.02% defoamer BYK024, 5% dispersant BYK190, 75% titanium dioxide R706, and 0.2% rheological additive WT-105A. In addition, Bayer XP2655 curing agent was diluted with PMA to 80% as curing agent component; the paint was prepared with a molar ratio of NCO:OH=1.6, and sprayed on tinplate, and the surface drying speed was observed in a room with a temperature of 25°C and a humidity of 32%. The pendulum hardness and gloss of the paint film were measured one, three, and seven days after the spraying. The hardness of the low-temperature drying plate was measured after the surface of the sprayed plate was dried for 10 minutes, then placed in a 70°C oven for 30 minutes, and then cooled for 5 hours before being tested again. The test results are shown in Table 1 below.

[0093] Among them, the drying speed is measured by the cotton ball blowing method. Place a cotton ball on the coating film at intervals, and blow gently in the horizontal direction with your mouth 10-15cm away from the cotton ball. If it can be blown away and no cotton threads are left on the film surface, the surface is considered to be dry; the self-drying hardness is measured by a pendulum hardness tester, at a temperature of 28.5℃ and a humidity of 41%; low-temperature baking conditions: 70℃, bake for 30 minutes, take out and cool for 5 hours before measuring; gloss is tested by a BYK gloss meter at an angle of 60 degrees; alcohol-resistant wiping test conditions: wet white gauze with analytical alcohol anhydrous alcohol, and wipe the coating surface of the low-temperature baking plate back and forth with a force of 1 kg until it is damaged.

[0094] Table 1

[0095]

[0096]

[0097] The above-mentioned embodiments only express several implementation methods of the present application, and the descriptions thereof are relatively specific and detailed, but they cannot be understood as limiting the scope of the present application. It should be pointed out that, for a person of ordinary skill in the art, several variations and improvements can be made without departing from the concept of the present application, and these all belong to the protection scope of the present application. Therefore, the protection scope of the present application shall be subject to the attached claims.

[0098] The above description is only a preferred embodiment of the present application and is not intended to limit the present application. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present application should be included in the protection scope of the present application.

Claims

1. A method for preparing an aqueous acrylic dispersion resin, characterized in that: include: After the acrylic resin is synthesized, the amino resin is added to the acrylic resin and the temperature is controlled to be 100-120° C., mixed and reacted for 25-40 minutes and then cooled naturally to obtain a modified resin; Adding a neutralizing agent to the modified resin and controlling the temperature to 100-120° C., neutralizing by natural cooling, cooling to between 100° C. and 70° C., and then adding water to disperse the modified resin to obtain a water-based acrylic dispersion resin; Wherein, the mass ratio of the acrylic resin to the amino resin is (50-96):(4-50).

2. A method for preparing an aqueous acrylic dispersion resin, characterized in that: include: After the acrylic resin is synthesized, a neutralizing agent is added to the acrylic resin and the temperature is controlled to be 100-120° C., and a natural cooling and neutralization treatment is performed to obtain a hydrophilic resin; Adding amino resin to the hydrophilic resin and controlling the temperature to 100-120° C., mixing and reacting for 25-40 minutes, cooling naturally, cooling to between 100° C. and 70° C., and then adding water to disperse, thereby obtaining a water-based acrylic dispersion resin; Wherein, the mass ratio of the acrylic resin to the amino resin is (50-96):(4-50).

3. The method for preparing an aqueous acrylic dispersion resin according to claim 1 or 2, characterized in that: The method for preparing an aqueous acrylic dispersion resin according to claim 1, wherein the mass ratio of the acrylic resin to the amino resin is (85-90):(10-15).

4. The method for preparing an aqueous acrylic dispersion resin according to claim 1 or 2, characterized in that: The synthetic monomers of the acrylic resin include the following monomers in percentage by mass: a1 monomer 70-80%, a2 monomer 2-20%, a3 monomer 0-5% and a4 monomer 0.5-5%; Among them, the a1 monomer is an ester or vinyl compound or allyl compound generated by an alcohol with 1 to 12 carbon atoms and acrylic acid or methacrylic acid; the a2 monomer is an acrylic acid or methacrylic acid ester containing at least one hydroxyl group; the a3 monomer is an acrylic acid or methacrylic acid ester containing an epoxy group or a keto carbonyl group; the a4 monomer is a carboxylic acid or sulfonic acid monomer containing an acidic functional group that can be neutralized with amines.

5. The method for preparing the aqueous acrylic dispersion resin according to claim 4, characterized in that: The synthetic monomers of the acrylic resin include the following monomers in percentage by mass: a1 monomer 75-80%, a2 monomer 10-20%, a3 monomer 2-3% and a4 monomer 2-3%.

6. The method for preparing the aqueous acrylic dispersion resin according to claim 4 or 5, characterized in that: The acrylic resin is obtained by adding a1 monomer, a2 monomer, a3 monomer, a4 monomer and an initiator to the organic solvent under the action of an organic solvent and controlling the temperature to be 135-155° C. for reaction; The organic solvent is one or more of trimethylbenzene, solvent naphtha, diethylene glycol butyl ether, dipropylene glycol butyl ether, dipropylene glycol methyl ether, n-butanol, ethylene glycol monobutyl ether, propylene glycol butyl ether, propylene glycol methyl ether, isopropanol and sec-butanol; The initiator is one or more of benzoic acid peroxide, tert-butyl perbenzoate, di-tert-butyl peroxide, di-tert-amyl peroxide, tert-butyl peroxy-2-ethylhexanoate, tert-amyl peroxy-2-ethylhexanoate, and di-tert-amyl peroxide.

7. The method for preparing the aqueous acrylic dispersion resin according to claim 4 or 5, characterized in that: The a1 monomer is one or more of styrene, allyltrimethoxysilane, allyltriethoxysilane, acrylonitrile, methyl acrylate, methyl methacrylate, butyl acrylate, butyl methacrylate, isobornyl acrylate, isobornyl methacrylate, ethyl acrylate, ethyl methacrylate, cyclohexyl acrylate, cyclohexyl methacrylate, isooctyl acrylate, isooctyl methacrylate, and tert-butyl methacrylate; The a2 monomer is one or more of hydroxyethyl acrylate, hydroxyethyl methacrylate, hydroxypropyl acrylate, hydroxypropyl methacrylate, hydroxybutyl acrylate, hydroxybutyl methacrylate, and polyethylene glycol acrylate; The a3 monomer is one or more of diacetone acrylamide, acetoxyethyl acrylate, acetoxyethyl methacrylate, glycidyl acrylate, and glycidyl methacrylate; The a4 monomer is one or more of acrylic acid, methacrylic acid, itaconic acid, and sulfonyl styrene.

8. The method for preparing an aqueous acrylic dispersion resin according to claim 1 or 2, characterized in that: The amino resin is one or more of highly methylated melamine resin, highly imino methylated melamine resin, partially methylated melamine resin, benzoguanamine resin, high solid content urea-formaldehyde resin, unalkylated methoxylated glycoluril resin and highly alkylated glycoluril resin.

9. A water-based acrylic dispersion resin, characterized in that: The water-based acrylic dispersion resin is prepared by the preparation method of the water-based acrylic dispersion resin according to any one of claims 1 to 8.

10. A water-based paint, characterized in that: The water-based coating comprises the water-based acrylic dispersion resin according to claim 9.

Images