Hydroxyl acrylic resin dispersion for water-based paint, preparation method and water-based paint

Abstract

The invention provides a hydroxy acrylic resin dispersion for water-based paint, a preparation method and the water-based paint, and belongs to the technical field of water-based acrylic resin. The hydroxy acrylic resin dispersion for the water-based paint comprises the following components in parts by mass: 2-3 parts of styrene; 7-8 parts by mass of methyl methacrylate; 23 to 24 parts by mass of isobutyl methacrylate; 2 to 3 parts by mass of hydroxypropyl methacrylate; 7 to 8 parts by mass of hydroxyethyl methylacrylate; 0.5-1 part by mass of acrylic acid; 0.1 to 0.5 part by mass of diacetone acrylamide; 0.5 to 1.5 parts by mass of ethylene glycol dimethacrylate; 2 to 3 parts by mass of peroxide (2-ethylhexanoic acid) tert-butyl ester; 2-3 parts by mass of diethylene glycol monomethyl ether; 1 to 2 parts by mass of N, N-dimethylethanolamine; and 45-55 parts by mass of deionized water. The dispersion and an isocyanate cross-linking agent are matched for use, so that the application effect of oil paint can be achieved, and meanwhile, the paint has good water resistance and acid and alkali resistance.

Description

Technical Field

[0001] The present invention belongs to the technical field of water-based acrylic resins, and in particular relates to a hydroxy acrylic resin dispersion for water-based paint, a preparation method thereof, and water-based paint. Background Art

[0002] Oil-based paints emit a large amount of VOC during their production and use, and cannot adapt to the requirements of environmental development. Therefore, it is necessary to develop other paints with low VOC emissions, such as water-based paints.

[0003] As an important component of water-based paint, the performance of water-based resin ultimately determines the performance of water-based paint. Compared with traditional solvent-based acrylic resin, water-based acrylic resin rarely uses or does not use organic solvents, has the advantages of reducing VOC emissions and being green and environmentally friendly. Water-based industrial paint made with it also has the advantages of low VOC emissions and being green and environmentally friendly during production and use; at the same time, water-based acrylic resin has excellent light, heat and chemical stability and weather resistance, so water-based acrylic resin has become the main direction of the current development of acrylic resin.

[0004] Waterborne hydroxy acrylic resin dispersion is the main raw material of waterborne paint, and its performance and stability play a vital role in the promotion and use of waterborne paint. Waterborne hydroxy acrylic resin dispersion needs to be used in conjunction with waterborne polyisocyanate curing agent to prepare high-end waterborne paint, which can be used in the fields of automobiles, rail trains, industrial equipment, etc. However, due to the high price of water-dispersible isocyanate curing agent, the further promotion of waterborne paint is limited. In addition, the current waterborne hydroxy acrylic resin dispersion has problems such as insufficient stability, slow drying speed, poor water resistance, and poor acid and alkali resistance. As a result, the water-borne paint or water-borne resin on the market currently generally has the disadvantages of poor water resistance and poor solvent resistance, especially the phenomenon that the paint film is prone to whitening when exposed to water. Summary of the invention

[0005] The present disclosure aims to solve at least one of the technical problems existing in the prior art, and provides a hydroxy acrylic resin dispersion for water-based paint, a preparation method, and a water-based paint.

[0006] In one aspect of the present disclosure, a hydroxyl acrylic resin dispersion for water-based paint is provided, wherein the raw materials of the hydroxyl acrylic resin dispersion for water-based paint include the following components in parts by weight: 2-3 parts by mass of styrene; 7-8 parts by mass of methyl methacrylate; 23-24 parts by mass of isobutyl methacrylate; 2-3 parts by mass of hydroxypropyl methacrylate; 7-8 parts by mass of hydroxyethyl methacrylate; 0.5-1 parts by mass of acrylic acid; 0.1-0.5 parts by mass of diacetone acrylamide; 0.5-1.5 parts by mass of ethylene glycol dimethacrylate; 2-3 parts by mass of tert-butyl peroxy(2-ethylhexanoate); 2-3 parts by mass of diethylene glycol methyl ether; 1-2 parts by mass of N,N-dimethylethanolamine; 45-55 parts by mass of deionized water.

[0007] Another aspect of the present disclosure provides a method for preparing the hydroxylated acrylic resin dispersion for water-based paint as described above, the method comprising: S110, forming a first monomer mixture from styrene, methyl methacrylate, isobutyl methacrylate, hydroxypropyl methacrylate, hydroxyethyl methacrylate, the total content of tert-butyl peroxide (2-ethylhexanoate), and diethylene glycol methyl ether; S120, forming a second monomer mixture by combining styrene, methyl methacrylate, isobutyl methacrylate, hydroxypropyl methacrylate, hydroxyethyl methacrylate, acrylic acid, diacetone acrylamide, ethylene glycol dimethacrylate, tert-butyl peroxide (2-ethylhexanoate), and diethylene glycol methyl ether; S130, adding diethylene glycol methyl ether into the reactor for the first time and stirring, heating to the first temperature under nitrogen protection, dropping the first monomer mixture, after the dropping is complete, continuing to drop the second monomer mixture, after the first insulation reaction, cooling to the second temperature, dropping styrene, adding diethylene glycol methyl ether for the second time after the dropping is complete, after the second insulation reaction, cooling to the third temperature, adding N,N-dimethylethanolamine, after the third insulation reaction, adding deionized water, heating to the fourth temperature for the fourth insulation reaction, cooling to room temperature, and obtaining a hydroxy acrylic resin dispersion.

[0008] Optionally, the amount of styrene added is 55-57% of the total content of the raw materials; The amount of methyl methacrylate added is 69-71% of the total content of the raw materials; The amount of isobutyl methacrylate added is 69-71% of the total content of the raw materials; The amount of hydroxypropyl methacrylate added is 82-84% of the total content of the raw materials; The amount of hydroxyethyl methacrylate added is 65-67% of the total content of the raw materials; The amount of tert-butyl peroxy (2-ethylhexanoate) added is 69-71% of the total content of the raw materials; The added amount of diethylene glycol methyl ether is 14-16% of the total content of the raw materials.

[0009] Optionally, the amount of styrene added is 23-25% of the total content of the raw materials; The amount of methyl methacrylate added is 29-31% of the total content of the raw materials; The amount of isobutyl methacrylate added is 29-31% of the total content of the raw materials; The amount of hydroxypropyl methacrylate added is 16-18% of the total content of the raw materials; The amount of hydroxyethyl methacrylate added is 33-35% of the total content of the raw materials; The amount of acrylic acid added is 100% of the total content of the raw materials; The added amount of diacetone acrylamide is 100% of the total content of the raw materials; The added amount of ethylene glycol dimethacrylate is 100% of the total content of the raw materials; The amount of tert-butyl peroxy (2-ethylhexanoate) added is 29-31% of the total content of the raw materials; The added amount of the diethylene glycol methyl ether is 6-8% of the total content of the raw materials.

[0010] Optionally, the content of the diethylene glycol methyl ether added for the first time is 75-77% of the total content of the raw materials; The amount of styrene added is 18-22% of the total content of the raw materials; The content of the diethylene glycol methyl ether added for the second time is 1-3% of the total content of the raw materials; The amount of N,N-dimethylethanolamine added is 100% of the total content of the raw materials.

[0011] Optionally, the first temperature is 130-140° C., and the first insulation reaction time is 0.3-1 hour; and / or, The second temperature is 110-125° C., and the second insulation reaction time is 1-2 hours; and / or, The third temperature is 70-90° C., and the third insulation reaction time is 0.2-1 hour; and / or, The fourth temperature is 50-70° C., and the fourth heat preservation reaction time is 0.2-1 hour.

[0012] Optionally, the dripping time of the first monomer mixture is controlled to be 3-4 hours.

[0013] Optionally, the dripping of the second monomer mixture is controlled within 1-2 hours.

[0014] Optionally, the time for adding styrene dropwise is controlled within 0.2-0.5 hours.

[0015] In another aspect of the present disclosure, a water-based paint is provided, wherein the water-based paint comprises an isocyanate cross-linking agent and the hydroxylated acrylic resin dispersion described above.

[0016] The present invention discloses a hydroxy acrylic resin dispersion for water-based paint, a preparation method, and a water-based paint. The raw materials of the hydroxy acrylic resin dispersion for water-based paint include the following components in parts by mass: 2-3 parts by mass of styrene; 7-8 parts by mass of methyl methacrylate; 23-24 parts by mass of isobutyl methacrylate; 2-3 parts by mass of hydroxypropyl methacrylate; 7-8 parts by mass of hydroxyethyl methacrylate; 0.5-1 parts by mass of acrylic acid; 0.1-0.5 parts by mass of diacetone acrylamide; 0.5-1.5 parts by mass of ethylene glycol dimethacrylate; 2-3 parts by mass of tert-butyl peroxide (2-ethylhexanoate); 2-3 parts by mass of diethylene glycol methyl ether; 1-2 parts by mass of N,N-dimethylethanolamine; and 45-55 parts by mass of deionized water. By optimizing the components and their contents, a hydroxy acrylic resin dispersion for water-based paint with excellent water resistance and acid and alkali resistance is formed. When it is used in water-based paint, the dispersion is used in combination with an isocyanate cross-linking agent to achieve the application effect of oil-based paint. At the same time, it also has good water resistance and acid and alkali resistance, and there is no need to carry out water-based treatment of the isocyanate cross-linking agent, thereby reducing costs. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 The present invention is a flowchart of a method for preparing a hydroxyl acrylic resin dispersion for water-based paint according to a specific embodiment of the present invention. DETAILED DESCRIPTION

[0018] In order to enable those skilled in the art to better understand the technical solution of the present disclosure, the present disclosure is further described in detail below in conjunction with the accompanying drawings and specific implementation methods. It should be understood that the specific embodiments described herein are only used to explain the present disclosure and are part of the embodiments of the present disclosure, rather than all of the embodiments. Based on the embodiments of the present disclosure, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present disclosure.

[0019] In one aspect of the present disclosure, a hydroxy acrylic resin dispersion for water-based paint is provided, wherein the raw materials of the hydroxy acrylic resin dispersion for water-based paint include the following components in parts by mass: 2-3 parts by mass of styrene; 7-8 parts by mass of methyl methacrylate; 23-24 parts by mass of isobutyl methacrylate; 2-3 parts by mass of hydroxypropyl methacrylate; 7-8 parts by mass of hydroxyethyl methacrylate; 0.5-1 parts by mass of acrylic acid; 0.1-0.5 parts by mass of diacetone acrylamide; 0.5-1.5 parts by mass of ethylene glycol dimethacrylate; 2-3 parts by mass of tert-butyl peroxide (2-ethylhexanoate); 2-3 parts by mass of diethylene glycol methyl ether; 1-2 parts by mass of N,N-dimethylethanolamine; and 45-55 parts by mass of deionized water.

[0020] Among them, styrene is used as a vinyl monomer; methyl methacrylate, isobutyl methacrylate, hydroxypropyl methacrylate, hydroxyethyl methacrylate, and acrylic acid are acrylate and propylene monomers, which constitute the basic units of the resin, provide cross-linking points and the basis for chemical reactions for the curing of the two-component water-based paint, and improve the dispersibility of the resin.

[0021] Secondly, diethylene glycol methyl ether is used as a hydrophilic solvent to adjust the viscosity and construction performance of the resin. N,N-dimethylethanolamine is used as a neutralizer to adjust the pH value of the resin and improve the stability of the resin. Tert-butyl peroxide (2-ethylhexanoate) is a free radical initiator, which is used for the polymerization reaction of vinyl, acrylic and propylene monomers, and can effectively initiate the polymerization of these monomers.

[0022] Furthermore, diacetone acrylamide has N-substituted amides and ketones, which are very easy to copolymerize with other ethylene and monomers to introduce ketone carbonyl groups into the polymer, prompting it to participate in cross-linking and grafting reactions, enhance adhesion, and improve acid and alkali resistance and chemical corrosion resistance. At the same time, ethylene glycol dimethacrylate increases the hardness of the paint film by participating in copolymerization, while improving water resistance, heat resistance, weather resistance, solvent resistance and friction resistance. In other words, diacetone acrylamide and ethylene glycol dimethacrylate are key components for water resistance and acid and alkali resistance. During the synthesis of the system, this component undergoes a grafting reaction with styrene and acrylate monomers to form a three-dimensional network cross-linked structure, which increases the cross-linking density and thereby improves water resistance, acid and alkali resistance and other chemical resistance properties. In addition, it is worth noting that the reactivity ratio of ethylene glycol dimethacrylate relative to other monomers shows a smaller value, such as compared with styrene, the ability to participate in copolymerization is relatively weak. Therefore, the present invention adds diacetone acrylamide, because the diacetone acrylamide component is very easy to copolymerize with a variety of monomers, so as to introduce ketocarbonyl groups into the polymer, so as to promote the participation of ethylene glycol dimethacrylate in the copolymerization. However, since diacetone acrylamide can also homopolymerize, the mass fraction of diacetone acrylamide is reduced, so as to promote the copolymerization of diacetone acrylamide. In other words, the diacetone acrylamide component added in the present invention can not only realize the copolymerization of itself with other monomers, but also can synergize with ethylene glycol dimethacrylate, promote the copolymerization of ethylene glycol dimethacrylate with other monomers, form a three-dimensional network cross-linked structure, improve the cross-linking density, and further improve the water resistance, solvent resistance and other properties of the paint film.

[0023] At the same time, the polyhydroxy structure in the system will further increase the cross-linking density when reacting with the isocyanate cross-linking agent in the later stage, thereby improving the water resistance, acid and alkali resistance and other chemical resistance of the paint film.

[0024] In some preferred embodiments, the total content of the styrene raw material may be preferably 2 parts by mass, 2.5 parts by mass, 3 parts by mass, etc.

[0025] In other preferred embodiments, the total content of the methyl methacrylate raw material may preferably be 7 parts by mass, 7.5 parts by mass, 8 parts by mass, etc.

[0026] In other preferred embodiments, the total content of the isobutyl methacrylate raw material may preferably be 23 parts by mass, 23.5 parts by mass, 24 parts by mass, etc.

[0027] In other preferred embodiments, the total content of the hydroxypropyl methacrylate raw material may be preferably 2 parts by mass, 2.5 parts by mass, 3 parts by mass, etc.

[0028] In other preferred embodiments, the total content of the hydroxyethyl methacrylate raw material may be preferably 7 parts by mass, 7.5 parts by mass, 8 parts by mass, etc.

[0029] In other preferred embodiments, the total content of the acrylic acid raw material may be preferably 0.5 parts by mass, 0.7 parts by mass, 1 part by mass, etc.

[0030] In other preferred embodiments, the total content of the diacetone acrylamide raw material may preferably be 0.1 parts by mass, 0.3 parts by mass, 0.5 parts by mass, etc.

[0031] In other preferred embodiments, the total content of the ethylene glycol dimethacrylate raw material may be preferably 0.5 parts by mass, 0.8 parts by mass, 1 part by mass, 1.5 parts by mass, etc.

[0032] In other preferred embodiments, the total content of the raw material of tert-butyl peroxy(2-ethylhexanoate) may be preferably 2 parts by mass, 2.5 parts by mass, 3 parts by mass, etc.

[0033] In other preferred embodiments, the total content of the diethylene glycol methyl ether raw material may preferably be 2 parts by mass, 2.5 parts by mass, 3 parts by mass, etc.

[0034] In other preferred embodiments, the total content of the N,N-dimethylethanolamine raw material may preferably be 1 part by mass, 1.5 parts by mass, 2 parts by mass, etc.

[0035] In other preferred embodiments, the total content of deionized water is preferably 1 part by mass, 1.5 parts by mass, 2 parts by mass, etc.

[0036] In this embodiment, by optimizing each component and its content, based on the interaction of each component, a hydroxy acrylic resin dispersion for water-based paint with excellent water resistance and acid and alkali resistance is formed. When it is used in water-based paint, the dispersion is used in combination with an isocyanate cross-linking agent to achieve the application effect of oil-based paint. At the same time, it also has good water resistance and acid and alkali resistance, especially the paint film is not prone to whitening when exposed to water, that is, there is no whitening phenomenon after being soaked in water. At the same time, there is no need to carry out water-based treatment of the isocyanate cross-linking agent, thereby reducing costs.

[0037] As shown in FIG. 1 , another aspect of the present disclosure provides a method S100 for preparing a hydroxylated acrylic resin dispersion for water-based paint, which specifically includes the following steps S110 to S130: S110, forming a first monomer mixed solution by combining styrene, methyl methacrylate, isobutyl methacrylate, hydroxypropyl methacrylate, hydroxyethyl methacrylate, the total content of tert-butyl peroxide (2-ethylhexanoate), and diethylene glycol methyl ether.

[0038] In step S110, the amount of styrene added is 55-57% of the total content of the raw materials, for example, 55%, 56%, 57%, etc., and specifically preferably 1.1-1.6 parts by mass.

[0039] In step S110, the amount of methyl methacrylate added is 69-71% of the total content of the raw materials, for example, 69%, 70%, 71%, etc., and specifically, preferably 4.9-5.6 parts by mass.

[0040] In step S110, the amount of isobutyl methacrylate added is 69-71% of the total content of the raw materials, for example, 69%, 70%, 71%, etc., and specifically preferably 15.9-17 parts by mass, etc.

[0041] In step S110, the amount of hydroxypropyl methacrylate added is 82-84% of the total content of the raw materials, for example, 82%, 83%, 84%, etc., and specifically preferably 1.6-2.5 parts by mass, etc.

[0042] In step S110, the amount of hydroxyethyl methacrylate added is 65-67% of the total content of the raw materials, for example, 65%, 66%, 67%, etc., and specifically, preferably 4.5-5.3 parts by mass, etc.

[0043] In step S110, the amount of tert-butyl peroxy (2-ethylhexanoate) added is 69-71% of the total content of the raw materials, for example, 69%, 70%, 71%, etc., and specifically preferably 1.4-2.1 parts by mass, etc.

[0044] In step S110, the amount of diethylene glycol methyl ether added is 14-16% of the total content of the raw materials, for example, 14%, 15%, 16%, etc., and specifically preferably 0.28-0.48 parts by mass, etc.

[0045] It should be understood that the amount of each component added is a portion of the total amount of the corresponding raw materials, that is, according to the total content of each raw material in the formula, a portion of them is first mixed to form the first monomer mixture, and the rest is added in other steps.

[0046] S120, styrene, methyl methacrylate, isobutyl methacrylate, hydroxypropyl methacrylate, hydroxyethyl methacrylate, acrylic acid, diacetone acrylamide, ethylene glycol dimethacrylate, tert-butyl peroxide (2-ethylhexanoate), and diethylene glycol methyl ether are added to form a second monomer mixture.

[0047] In step S120, the amount of styrene added is 23-25% of the total content of the raw materials, for example, 23%, 24%, 25%, etc., and specifically preferably 0.46-0.75 parts by mass.

[0048] In step S120, the amount of methyl methacrylate added is 29-31% of the total content of the raw materials, for example, 29%, 30%, 31%, etc., that is, the remaining methyl methacrylate in the formula is added to step S120.

[0049] In step S120, the amount of isobutyl methacrylate added is 29-31% of the total content of the raw materials, for example, 29%, 30%, 31%, etc., that is, the remaining isobutyl methacrylate in the formula is added to step S120.

[0050] In step S120, the amount of hydroxypropyl methacrylate added is 16-18% of the total content of the raw materials, for example, 16%, 17%, 18%, etc., that is, the remaining hydroxypropyl methacrylate in the formula is added to step S120.

[0051] In step S120, the amount of hydroxyethyl methacrylate added is 33-35% of the total content of the raw materials, for example, 33%, 34%, 35%, etc., that is, the remaining hydroxyethyl methacrylate in the formula is added to step S120.

[0052] In step S120, the amount of acrylic acid added is 100% of the total content of the raw materials, that is, all the acrylic acid is added to step S120, preferably 0.5-1 parts by mass.

[0053] In step S120, the amount of diacetone acrylamide added is 100% of the total content of the raw materials, that is, all of the diacetone acrylamide is added to step S120, preferably 0.1-0.5 parts by mass.

[0054] In step S120, the amount of ethylene glycol dimethacrylate added is 100% of the total content of the raw materials, that is, all of the ethylene glycol dimethacrylate is added to step S120, preferably 0.5-1.5 parts by mass.

[0055] In step S120, the amount of tert-butyl peroxy (2-ethylhexanoate) added is 29-31% of the total content of the raw materials, for example, 29%, 30%, 31%, and preferably 0.6-0.9 parts by mass.

[0056] In step S120, the amount of diethylene glycol methyl ether added is 6-8% of the total content of the raw materials, for example, 6%, 7%, 8%, and preferably 0.12-0.24 parts by mass.

[0057] S130, adding diethylene glycol methyl ether into the reactor for the first time and stirring, heating to the first temperature under nitrogen protection, dropping the first monomer mixture, after the dropping is completed, continuing to drop the second monomer mixture, after the first heat preservation reaction, cooling to the second temperature, dropping styrene, after the dropping is completed, adding the remaining diethylene glycol methyl ether for the second time, after the second heat preservation reaction, cooling to the third temperature, adding N,N-dimethylethanolamine, after the third heat preservation reaction, adding deionized water, heating to the fourth temperature for the fourth heat preservation reaction, cooling to room temperature, and obtaining a hydroxy acrylic resin dispersion.

[0058] In step S130, the content of diethylene glycol methyl ether added for the first time is 75-77% of the total content of the raw materials, for example, 75%, 76%, 77%, and specifically preferably 1.5-2.3 parts by mass. The content of diethylene glycol methyl ether added for the second time is 1-3% of the total content of the raw materials, for example, 1%, 2%, 3%, that is, all the remaining diethylene glycol methyl ether in the formula is added to step S130.

[0059] In step S130, the amount of styrene added is 18-22% of the total content of the raw materials, for example, 18%, 20%, 22%, that is, all the remaining styrene in the formula is added to step S130.

[0060] In step S130, the amount of N,N-dimethylethanolamine added is 100% of the total content of the raw materials, that is, all the N,N-dimethylethanolamine in the formula is added to step S130, and specifically, 1-2 parts by mass may be preferred.

[0061] Further, in step 130, the first temperature is 130-140°C, for example, 130°C, 135°C, 140°C, etc., and the first insulation reaction time is 0.3-1 hour, for example, 0.3 hour, 0.5 hour, 1 hour, etc.

[0062] In step 130, the second temperature is 110-125°C, for example, 110°C, 115°C, 120°C, 125°C, etc., and the second insulation reaction time is 1-2 hours, for example, 1 hour, 1.5 hours, 2 hours, etc.

[0063] In this embodiment, by controlling the reaction temperature (including the first temperature and the second temperature) within the above range, it helps to shorten the half-life of the initiator (tert-butyl peroxide (2-ethylhexanoate)), thereby improving the reaction efficiency, and the above reaction time range just matches the half-life of the initiator. If the reaction time is too long, production time will be wasted, and if the reaction time is too short, the monomer will not be fully reacted. Therefore, controlling the above second temperature and the first temperature within the above range helps to reduce the reaction time and improve efficiency.

[0064] In step 130, the third temperature is 70-90°C, for example, 70°C, 80°C, 90°C, etc., and the third insulation reaction time is 0.2-1 hour, for example, 0.2 hour, 0.5 hour, 1 hour, etc.

[0065] In step 130, the fourth temperature is 50-70°C, for example, 50°C, 60°C, 70°C, etc., and the fourth insulation reaction time is 0.2-1 hour, for example, 0.2 hour, 0.5 hour, 1 hour, etc.

[0066] Furthermore, in step S130, the dripping time of the first monomer mixed solution is controlled to be 3-4 hours, for example, 3 hours, 3.5 hours, 4 hours, etc.

[0067] In step S130, the second monomer mixture is added dropwise for 1-2 hours, for example, 1 hour, 1.5 hours, 2 hours, etc.

[0068] In step S130, the time for adding styrene dropwise is controlled to be 0.2-0.5 hours, for example, 0.2 hours, 0.3 hours, 0.5 hours, etc.

[0069] In the preparation process provided in this embodiment, by forming a monomer mixture in steps and adding the monomer mixture in steps to the reactor to react at different temperatures during the reaction process, diacetone acrylamide and ethylene glycol dimethacrylate can be fully grafted, and the two are copolymerized with other monomers to form a three-dimensional network cross-linked structure, effectively improving the cross-linking density. Compared with the dispersion formed by conventional one-step polymerization, it has good water resistance and acid and alkali resistance. In addition, the preparation method is easy to implement in practical applications, has been verified in different reactors, can quickly achieve mass production, and the prepared dispersion has good water resistance and acid and alkali resistance. When used in combination with an isocyanate cross-linking agent, the isocyanate cross-linking agent does not require other water resistance treatment.

[0070] In another aspect of the present disclosure, a water-based paint is provided. The water-based paint includes an isocyanate crosslinking agent and the hydroxylated acrylic resin dispersion given above.

[0071] When the hydroxy acrylic resin dispersion proposed in this embodiment is used in combination with an isocyanate crosslinking agent, the application effect of an oil-based paint can be achieved, and the paint has very good water resistance and acid and alkali resistance.

[0072] It should be noted that when the hydroxy acrylic resin dispersion is used in combination with the isocyanate crosslinking agent, the mass ratio of the two is preferably in the range of 100:(20-30).

[0073] In some preferred embodiments, the mass ratio of the hydroxylated acrylic resin dispersion to the isocyanate crosslinking agent is preferably 100:20, 100:25, 100:30, etc.

[0074] The preparation method and components of the hydroxy acrylic resin dispersion will be further described below in conjunction with specific examples: Example 1 The raw material components of the hydroxy acrylic resin dispersion in this example are as follows by weight: 2.3 parts by weight of styrene Methyl methacrylate 7.1 parts by mass Isobutyl methacrylate 23.8 parts by mass 2.5 parts by mass of hydroxypropyl methacrylate Hydroxyethyl methacrylate 7.8 parts by mass Acrylic acid 0.9 parts by mass Diacetone acrylamide 0.2 parts by mass 1.0 parts by mass of ethylene glycol dimethacrylate 2.0 parts by mass of tert-butyl peroxy(2-ethylhexanoate) 1.1 parts by mass of N,N-dimethylethanolamine 2.1 parts by mass of diethylene glycol methyl ether Deionized water 49.2 parts by mass The total amount was 100 parts by mass.

[0075] Furthermore, the preparation method of the hydroxylated acrylic resin dispersion comprises the following steps: S1, take 55% of the total amount of styrene in the above formula, i.e. 1.265 parts; 70% of the total amount of methyl methacrylate, i.e. 4.97 parts; 70% of the total amount of isobutyl methacrylate, i.e. 16.66 parts; 84% of the total amount of hydroxypropyl methacrylate, i.e. 2.1 parts; 66% of the total amount of hydroxyethyl methacrylate, i.e. 5.148 parts; 70% of the total amount of tert-butyl peroxide (2-ethylhexanoate), i.e. 1.4 parts; 15% of the total amount of diethylene glycol methyl ether, i.e. 0.315 parts, to form a first monomer mixture; S2, take 23% of the total amount of styrene in the above formula, i.e. 0.529 parts; the remaining methyl methacrylate; the remaining isobutyl methacrylate; the remaining hydroxypropyl methacrylate, the remaining hydroxyethyl methacrylate, all acrylic acid, diacetone acrylamide and ethylene glycol dimethacrylate, the remaining tert-butyl peroxide (2-ethylhexanoate), and 7% of the total amount of diethylene glycol methyl ether, i.e. 0.147 parts, to form a second monomer mixture; S3, take 77% of the total amount of diethylene glycol methyl ether, i.e. 1.617 parts of diethylene glycol methyl ether are added to the reactor with nitrogen protection, heating, stirring and condensation reflux, start stirring, heat to 132 ° C under nitrogen protection, slowly drip the first monomer mixture, the dropping time is controlled at 3.2 hours, after completion of dropwise addition, continue to drip the second monomer mixture, the dropping time is controlled at 1.5 hours, after insulation reaction for 1 hour, cool to 115 ° C, drip the remaining styrene, the dropping time is controlled at 0.25 hour, after completion of dropwise addition, add the remaining diethylene glycol methyl ether, keep warm for 1 hour, cool to 75 ° C, add N, N-dimethylethanolamine, keep warm for 0.5 hour, increase stirring speed, add deionized water, warm to 60 ° C, keep warm for 0.5 hour, cool to room temperature, and filter the discharging.

[0076] Furthermore, the hydroxyl acrylic resin dispersion obtained in Example 1 is used in combination with an isocyanate crosslinker, and the water resistance test results of the obtained paint film are shown in Table 1. After being soaked in hot water at 40°C for 10 days and in hot water at 90°C for 40 minutes, the paint film has no whitening phenomenon. After being soaked in 5% sulfuric acid solution, 5% sodium hydroxide solution and industrial alcohol, the number of scrubbing resistance is still greater than 600 times, which shows that the paint film obtained when the dispersion obtained in this example is used in combination with an isocyanate crosslinker has good water resistance and acid and alkali resistance.

[0077] Example 2 The raw material components of the hydroxy acrylic resin dispersion in this example are as follows by weight: 3 parts by weight of styrene 8 parts by mass of methyl methacrylate Isobutyl methacrylate 24 parts by mass 2.5 parts by mass of hydroxypropyl methacrylate Hydroxyethyl methacrylate 7 parts by mass Acrylic acid 0.5 parts by mass Diacetone acrylamide 0.5 parts by mass 1.5 parts by mass of ethylene glycol dimethacrylate 3.0 parts by mass of tert-butyl peroxy(2-ethylhexanoate) 2 parts by mass of N,N-dimethylethanolamine 3 parts by mass of diethylene glycol methyl ether Deionized water 45 parts by mass The total amount was 100 parts by mass.

[0078] Furthermore, the preparation method of the hydroxylated acrylic resin dispersion comprises the following steps: S1, take 57% of the total amount of styrene in the above formula, i.e. 1.71 parts; 69% of the total amount of methyl methacrylate, i.e. 5.52 parts; 69% of the total amount of isobutyl methacrylate, i.e. 16.56 parts; 82% of the total amount of hydroxypropyl methacrylate, i.e. 2.05 parts; 65% of the total amount of hydroxyethyl methacrylate, i.e. 4.55 parts; 69% of the total amount of tert-butyl peroxide (2-ethylhexanoate), i.e. 2.07 parts; 14% of the total amount of diethylene glycol methyl ether, i.e. 0.42 parts, to form a first monomer mixture; S2, take 25% of the total amount of styrene in the above formula, i.e. 0.75 parts; the remaining methyl methacrylate; the remaining isobutyl methacrylate; the remaining hydroxypropyl methacrylate, the remaining hydroxyethyl methacrylate, all acrylic acid, diacetone acrylamide and ethylene glycol dimethacrylate, the remaining tert-butyl peroxide (2-ethylhexanoate), and 8% of the total amount of diethylene glycol methyl ether, i.e. 0.24 parts, to form a second monomer mixture; S3, take 78% of the total amount of diethylene glycol methyl ether, i.e. 2.34 parts of diethylene glycol methyl ether are added to the reactor with nitrogen protection, heating, stirring and condensation reflux, start stirring, heat to 132 ° C under nitrogen protection, slowly drip the first monomer mixture, the dropping time is controlled at 3.2 hours, after completion of dropwise addition, continue to drip the second monomer mixture, the dropping time is controlled at 1.5 hours, after insulation reaction for 1 hour, cool to 115 ° C, drip the remaining styrene, the dropping time is controlled at 0.25 hour, after completion of dropwise addition, add the remaining diethylene glycol methyl ether, keep warm for 1 hour, cool to 75 ° C, add N, N-dimethylethanolamine, keep warm for 0.5 hour, increase stirring speed, add deionized water, warm to 60 ° C, keep warm for 0.5 hour, cool to room temperature, and filter the discharging.

[0079] Furthermore, the hydroxyl acrylic resin dispersion obtained in Example 2 is used in combination with an isocyanate crosslinker, and the obtained paint film water resistance test results are shown in Table 1. It can be seen that changing the content of each component has little effect on the paint film, and all have good water resistance and acid and alkali resistance.

[0080] Example 3 The raw material composition of the hydroxy acrylic resin dispersion in this example is the same as that in Example 1 in terms of weight ratio.

[0081] Furthermore, the preparation method of the hydroxylated acrylic resin dispersion comprises the following steps: S1, take 57% of the total amount of styrene in the above formula, i.e. 1.71 parts; 69% of the total amount of methyl methacrylate, i.e. 5.52 parts; 69% of the total amount of isobutyl methacrylate, i.e. 16.56 parts; 82% of the total amount of hydroxypropyl methacrylate, i.e. 2.05 parts; 65% of the total amount of hydroxyethyl methacrylate, i.e. 4.55 parts; 69% of the total amount of tert-butyl peroxide (2-ethylhexanoate), i.e. 2.07 parts; 14% of the total amount of diethylene glycol methyl ether, i.e. 0.42 parts, to form a first monomer mixture; S2, take 25% of the total amount of styrene in the above formula, i.e. 0.75 parts; the remaining methyl methacrylate; the remaining isobutyl methacrylate; the remaining hydroxypropyl methacrylate, the remaining hydroxyethyl methacrylate, all acrylic acid, diacetone acrylamide and ethylene glycol dimethacrylate, the remaining tert-butyl peroxide (2-ethylhexanoate), and 8% of the total amount of diethylene glycol methyl ether, i.e. 0.24 parts, to form a second monomer mixture; S3, take 78% of the total amount of diethylene glycol methyl ether, i.e. 2.34 parts of diethylene glycol methyl ether, add to the reactor with nitrogen protection, heating, stirring and condensation reflux, start stirring, heat to 140 ℃ under nitrogen protection, slowly drip the first monomer mixed solution, the dropping time is controlled at 3.6 hours, after completion of dropwise addition, continue to drip the second monomer mixed solution, the dropping time is controlled at 1.8 hours, after insulation reaction for 1.5 hours, cool to 120 ℃, drip the remaining styrene, the dropping time is controlled at 0.45 hour, after completion of dropwise addition, add the remaining diethylene glycol methyl ether, keep warm for 1.5 hours, cool to 85 ℃, add N, N-dimethylethanolamine, keep warm for 1 hour, increase stirring speed, add deionized water, warm to 70 ℃, keep warm for 1 hour, cool to room temperature, and filter the discharging.

[0082] Furthermore, the hydroxyl acrylic resin dispersion obtained in Example 3 is used in combination with an isocyanate crosslinker, and the water resistance test results of the obtained paint film are shown in Table 1. It can be seen that changing the insulation temperature, time and dripping time in the preparation process has little effect on the results of the paint film, and all have good water resistance and acid and alkali resistance.

[0083] Comparative Example 1 The same as Example 1, except that there is no diacetone acrylamide and ethylene glycol dimethacrylate in the raw materials, and the raw material components of the hydroxy acrylic resin dispersion are as follows by weight: Styrene 5 parts by mass 8 parts by mass of methyl methacrylate Isobutyl methacrylate 24 parts by mass 2.5 parts by mass of hydroxypropyl methacrylate Hydroxyethyl methacrylate 7 parts by mass Acrylic acid 0.5 parts by mass 3.0 parts by mass of tert-butyl peroxy(2-ethylhexanoate) 2 parts by mass of N,N-dimethylethanolamine 3 parts by mass of diethylene glycol methyl ether Deionized water 45 parts by mass The total amount was 100 parts by mass.

[0084] Furthermore, the preparation method of the hydroxylated acrylic resin dispersion comprises the following steps: S1, take 57% of the total amount of styrene in the above formula, i.e. 1.71 parts; 69% of the total amount of methyl methacrylate, i.e. 5.52 parts; 69% of the total amount of isobutyl methacrylate, i.e. 16.56 parts; 82% of the total amount of hydroxypropyl methacrylate, i.e. 2.05 parts; 65% of the total amount of hydroxyethyl methacrylate, i.e. 4.55 parts; 69% of the total amount of tert-butyl peroxide (2-ethylhexanoate), i.e. 2.07 parts; 14% of the total amount of diethylene glycol methyl ether, i.e. 0.42 parts, to form a first monomer mixture; S2, take 25% of the total amount of styrene in the above formula, i.e. 0.75 parts; the remaining methyl methacrylate; the remaining isobutyl methacrylate; the remaining hydroxypropyl methacrylate, the remaining hydroxyethyl methacrylate, all acrylic acid, the remaining tert-butyl peroxide (2-ethylhexanoate), and 8% of the total amount of diethylene glycol methyl ether, i.e. 0.24 parts, to form a second monomer mixture; S3, take 78% of the total amount of diethylene glycol methyl ether, i.e. 2.34 parts of diethylene glycol methyl ether are added to the reactor with nitrogen protection, heating, stirring and condensation reflux, start stirring, heat to 132 ° C under nitrogen protection, slowly drip the first monomer mixture, the dropping time is controlled at 3.2 hours, after completion of dropwise addition, continue to drip the second monomer mixture, the dropping time is controlled at 1.5 hours, after insulation reaction for 1 hour, cool to 115 ° C, drip the remaining styrene, the dropping time is controlled at 0.25 hour, after completion of dropwise addition, add the remaining diethylene glycol methyl ether, keep warm for 1 hour, cool to 75 ° C, add N, N-dimethylethanolamine, keep warm for 0.5 hour, increase stirring speed, add deionized water, warm to 60 ° C, keep warm for 0.5 hour, cool to room temperature, and filter the discharging.

[0085] The hydroxy acrylic resin dispersion obtained in this comparative example 1 is used in combination with an isocyanate crosslinker, and the water resistance test results of the obtained paint film are shown in Table 2. It can be seen that when diacetone acrylamide and ethylene glycol dimethacrylate are not added, the obtained paint film appears white and does not have good water resistance and acid and alkali resistance.

[0086] Comparative Example 2 The same as Example 1, except that there is no diacetone acrylamide in the raw material, and the raw material components of the hydroxy acrylic resin dispersion are as follows by weight: Styrene 2.5 parts by mass Methyl methacrylate 7.1 parts by mass Isobutyl methacrylate 23.8 parts by mass 2.5 parts by mass of hydroxypropyl methacrylate Hydroxyethyl methacrylate 7.8 parts by mass Acrylic acid 0.9 parts by mass 1.0 parts by mass of ethylene glycol dimethacrylate 2.0 parts by mass of tert-butyl peroxy(2-ethylhexanoate) 1.1 parts by mass of N,N-dimethylethanolamine 2.1 parts by mass of diethylene glycol methyl ether Deionized water 49.2 parts by mass The total amount was 100 parts by mass.

[0087] Furthermore, the preparation method of the hydroxylated acrylic resin dispersion is the same as that of Example 1.

[0088] The hydroxy acrylic resin dispersion obtained in this comparative example 2 was used in combination with an isocyanate crosslinking agent. The water resistance test results of the obtained paint film are shown in Table 2. It can be seen that when diacetone acrylamide is not added, the obtained paint film has a slight whitening phenomenon and does not have good water resistance and acid and alkali resistance.

[0089] Comparative Example 3 The same as Example 1, except that there is no ethylene glycol dimethacrylate in the raw materials, and the raw material components of the hydroxy acrylic resin dispersion are as follows by weight: Styrene 3.5 parts by mass Methyl methacrylate 7.1 parts by mass Isobutyl methacrylate 23.8 parts by mass 2.5 parts by mass of hydroxypropyl methacrylate Hydroxyethyl methacrylate 7.8 parts by mass Acrylic acid 0.9 parts by mass Diacetone acrylamide 0.2 parts by mass 2.0 parts by mass of tert-butyl peroxy(2-ethylhexanoate) 1.1 parts by mass of N,N-dimethylethanolamine 2.1 parts by mass of diethylene glycol methyl ether Deionized water 49.2 parts by mass The total amount was 100 parts by mass.

[0090] Furthermore, the preparation method of the hydroxylated acrylic resin dispersion is the same as that of Example 1.

[0091] The hydroxyl acrylic resin dispersion obtained in this comparative example 3 was used in combination with an isocyanate crosslinker, and the water resistance test results of the obtained paint film are shown in Table 2. It can be seen that when ethylene glycol dimethacrylate is not added, the obtained paint film has a slight whitening phenomenon and does not have good water resistance and acid and alkali resistance.

[0092] Comparative Example 4 The same as Example 1, except that the mass fraction of diacetone acrylamide is 1, and the raw material components of the hydroxy acrylic resin dispersion are as follows by weight: Styrene 1.5 parts by mass Methyl methacrylate 7.1 parts by mass Isobutyl methacrylate 23.8 parts by mass 2.5 parts by mass of hydroxypropyl methacrylate Hydroxyethyl methacrylate 7.8 parts by mass Acrylic acid 0.9 parts by mass 1.0 parts by mass of diacetone acrylamide 1.0 parts by mass of ethylene glycol dimethacrylate 2.0 parts by mass of tert-butyl peroxy(2-ethylhexanoate) 1.1 parts by mass of N,N-dimethylethanolamine 2.1 parts by mass of diethylene glycol methyl ether Deionized water 49.2 parts by mass The total amount was 100 parts by mass.

[0093] Furthermore, the preparation method of the hydroxylated acrylic resin dispersion is the same as that of Example 1.

[0094] The hydroxy acrylic resin dispersion obtained in this comparative example 4 is used in combination with an isocyanate crosslinker, and the water resistance test results of the obtained paint film are shown in Table 2. It can be seen that when containing ethylene glycol dimethacrylate and diacetone acrylamide, but the diacetone acrylamide content is high, the obtained paint film shows a slight whitening phenomenon and does not have good water resistance and acid and alkali resistance.

[0095] In summary, the hydroxyl acrylic resin dispersions obtained in Comparative Examples 1 to 4 were used in combination with an isocyanate crosslinker, and the water resistance test results of the obtained paint films are shown in Table 2. It can be seen that when the raw materials do not contain diacetone acrylamide and / or ethylene glycol dimethacrylate, the paint film appears white after immersion, and the number of scrub resistance is unqualified, and it does not have good water resistance and acid and alkali resistance.

[0096] Comparative Example 5 The raw material composition is the same as that of Example 1, except that a conventional one-step polymerization method is adopted, including: Styrene, methyl methacrylate, isobutyl methacrylate, hydroxypropyl methacrylate, hydroxyethyl methacrylate, tert-butyl peroxide (2-ethylhexanoate), acrylic acid, diacetone acrylamide, ethylene glycol dimethacrylate and diethylene glycol methyl ether are formed into a monomer mixture, which is then kept at 140°C for 3 hours, cooled to 60°C, N,N-dimethylethanolamine is added for neutralization, and finally deionized water is added for high-speed dispersion to obtain a dispersion.

[0097] The hydroxy acrylic resin dispersion obtained in this comparative example 5 is used in combination with an isocyanate crosslinking agent, and the water resistance test results of the obtained paint film are shown in Table 2. It can be seen that when the one-step polymerization is adopted, the obtained paint film has a slight whitening phenomenon and does not have good water resistance and acid and alkali resistance. This shows that the conventional preparation method cannot meet the full mixing of the components, and diacetone acrylamide and ethylene glycol dimethacrylate do not fully undergo a grafting reaction, and a three-dimensional network cross-linking structure cannot be formed, which in turn has an adverse effect on the water resistance and acid and alkali resistance of the paint film.

[0098] Table 1 Test results of water resistance of paint films in various embodiments

[0099] Table 2 Water resistance test results of paint films of various comparative examples

[0100] It is to be understood that the above embodiments are merely exemplary embodiments for illustrating the principles of the present disclosure, but the present disclosure is not limited thereto. For those skilled in the art, various modifications and improvements can be made without departing from the spirit and essence of the present disclosure, and these modifications and improvements are also considered to be within the scope of protection of the present disclosure.

Claims

1. A hydroxy acrylic resin dispersion for water-based paint, characterized in that: The raw materials of the hydroxylated acrylic resin dispersion for water-based paint include the following components in parts by mass: 2-3 parts by mass of styrene; 7-8 parts by mass of methyl methacrylate; 23-24 parts by mass of isobutyl methacrylate; 2-3 parts by mass of hydroxypropyl methacrylate; 7-8 parts by mass of hydroxyethyl methacrylate; 0.5-1 parts by mass of acrylic acid; 0.1-0.5 parts by mass of diacetone acrylamide; 0.5-1.5 parts by mass of ethylene glycol dimethacrylate; 2-3 parts by mass of tert-butyl peroxy(2-ethylhexanoate); 2-3 parts by mass of diethylene glycol methyl ether; 1-2 parts by mass of N,N-dimethylethanolamine; 45-55 parts by mass of deionized water.

2. A method for preparing the hydroxylated acrylic resin dispersion for water-based paint as claimed in claim 1, characterized in that: The method comprises: S110, forming a first monomer mixture from styrene, methyl methacrylate, isobutyl methacrylate, hydroxypropyl methacrylate, hydroxyethyl methacrylate, the total content of tert-butyl peroxide (2-ethylhexanoate), and diethylene glycol methyl ether; S120, forming a second monomer mixture by combining styrene, methyl methacrylate, isobutyl methacrylate, hydroxypropyl methacrylate, hydroxyethyl methacrylate, acrylic acid, diacetone acrylamide, ethylene glycol dimethacrylate, tert-butyl peroxide (2-ethylhexanoate), and diethylene glycol methyl ether; S130, adding diethylene glycol methyl ether into the reactor for the first time and stirring, heating to the first temperature under nitrogen protection, dropping the first monomer mixture, after the dropping is complete, continuing to drop the second monomer mixture, after the first insulation reaction, cooling to the second temperature, dropping styrene, adding diethylene glycol methyl ether for the second time after the dropping is complete, after the second insulation reaction, cooling to the third temperature, adding N,N-dimethylethanolamine, after the third insulation reaction, adding deionized water, heating to the fourth temperature for the fourth insulation reaction, cooling to room temperature, and obtaining a hydroxy acrylic resin dispersion.

3. The method according to claim 2, characterized in that In step S110, the amount of styrene added is 55-57% of the total content of the raw materials; The amount of methyl methacrylate added is 69-71% of the total content of the raw materials; The amount of isobutyl methacrylate added is 69-71% of the total content of the raw materials; The amount of hydroxypropyl methacrylate added is 82-84% of the total content of the raw materials; The amount of hydroxyethyl methacrylate added is 65-67% of the total content of the raw materials; The amount of tert-butyl peroxy (2-ethylhexanoate) added is 69-71% of the total content of the raw materials; The added amount of diethylene glycol methyl ether is 14-16% of the total content of the raw materials.

4. The method according to claim 2, characterized in that: In step S120, the amount of styrene added is 23-25% of the total content of the raw materials; The amount of methyl methacrylate added is 29-31% of the total content of the raw materials; The amount of isobutyl methacrylate added is 29-31% of the total content of the raw materials; The amount of hydroxypropyl methacrylate added is 16-18% of the total content of the raw materials; The amount of hydroxyethyl methacrylate added is 33-35% of the total content of the raw materials; The amount of acrylic acid added is 100% of the total content of the raw materials; The added amount of diacetone acrylamide is 100% of the total content of the raw materials; The added amount of ethylene glycol dimethacrylate is 100% of the total content of the raw materials; The amount of tert-butyl peroxy (2-ethylhexanoate) added is 29-31% of the total content of the raw materials; The added amount of the diethylene glycol methyl ether is 6-8% of the total content of the raw materials.

5. The method according to claim 2, characterized in that: In step S130, the content of the diethylene glycol methyl ether added for the first time is 75-77% of the total content of the raw materials; The amount of styrene added is 18-22% of the total content of the raw materials; The content of the diethylene glycol methyl ether added for the second time is 1-3% of the total content of the raw materials; The amount of N,N-dimethylethanolamine added is 100% of the total content of the raw materials.

6. The method according to claim 2, characterized in that The first temperature is 130-140° C., and the first insulation reaction time is 0.3-1 hour; and / or, The second temperature is 110-125° C., and the second insulation reaction time is 1-2 hours; and / or, The third temperature is 70-90° C., and the third insulation reaction time is 0.2-1 hour; and / or, The fourth temperature is 50-70° C., and the fourth heat preservation reaction time is 0.2-1 hour.

7. The method according to claim 2, characterized in that The dripping time of the first monomer mixed solution is controlled within 3-4 hours.

8. The method according to claim 2, characterized in that: The time for adding the second monomer mixture dropwise is controlled to be 1-2 hours.

9. The method according to claim 2, characterized in that: The time for adding styrene dropwise is controlled at 0.2-0.5 hours.

10. A water-based paint, characterized in that: The water-based paint comprises an isocyanate crosslinking agent and the hydroxy acrylic resin dispersion according to claim 1.

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