A hydroxyl acrylic dispersion, applications and methods of making same

Abstract

The application relates to the technical field of water-based paint, and particularly discloses a hydroxyl acrylic dispersion, application and preparation method thereof. The hydroxyl acrylic dispersion comprises the following raw materials in percentage by mass: a medium-high boiling point reactant, a first compound, a second compound, a third compound, a fourth compound, an initiator, a salt forming agent, deionized water, the first compound is one or both of a long carbon chain alkyl ester polymerizable monomer and a hydrolysable ester bond-free polymerizable monomer, the second compound is one or both of a methyl acrylic acid lower alkyl ester and a free radical polymerizable monomer containing active hydrogen, and the fourth compound is one or both of a polymerizable monomer and an alcohol ether hydroxyl compound polymerizable monomer. The hydroxyl acrylic dispersion provided by the application can be used in water-based paint, and has the advantages of excellent mechanical physical performance, excellent chemical resistance and the like.

Description

Technical Field

[0001] This application relates to the technical field of waterborne coatings, and more specifically, to a hydroxy acrylic dispersion, its application, and a method for its preparation. Background Technology

[0002] Two-component polyurethane is a polyurethane resin formed by curing and crosslinking a compound containing hydroxyl functional groups with a polyisocyanate curing agent. Among them, curing and crosslinking with a hydroxypropyl dispersion and a polyisocyanate curing agent is more common. As two-component polyurethane has received more and more attention in industrial production, its production scale is also growing. Therefore, the demand for preparing two-component polyurethane self-drying paint using hydroxyl acrylic dispersion is also increasing.

[0003] Currently, the main technology for preparing waterborne hydroxypropyl dispersions is solution polymerization, followed by neutralization with an amine neutralizer and dispersion with water to achieve waterborne properties. This technology is currently the primary preparation method and is quite mature. Dispersions prepared by this method have received good evaluations and are widely used in terms of performance, industrialization, and end-customer applications. However, hydroxypropyl dispersions prepared by solution polymerization also have some drawbacks, such as generally poor physical and mechanical properties, poor chemical resistance, and a simple molecular structure. Summary of the Invention

[0004] To improve the mechanical and physical properties, weather resistance, and the shortcomings of simple molecular structure in hydroxyl acrylic acid dispersions, this application provides a hydroxyl acrylic acid dispersion, its application, and its preparation method, employing the following technical solution:

[0005] In a first aspect, this application provides a hydroxyacrylic acid dispersion comprising the following raw materials in weight percentages:

[0006] 7-8% of medium- to high-boiling-point reactants;

[0007] The first compound was 4.2-6.3%;

[0008] The second compound was 13.65-15.75%;

[0009] The third compound was 13.65-5.76%;

[0010] The fourth compound was 6.3-8.4%;

[0011] Initiator 1.26-1.68%;

[0012] Salt-forming agent 1.2-1.4%;

[0013] Deionized water balance;

[0014] The medium-to-high boiling point reactants are polar or non-polar reactive compounds with boiling points above 140°C;

[0015] The first compound is one or two of long-chain alkyl ester polymerizable monomers and polymerizable monomers without hydrolyzable ester bonds;

[0016] The second compound is one or two of a lower alkyl methacrylate and a free radical polymerizable monomer containing active hydrogen.

[0017] The third compound is 50% by weight of the second compound;

[0018] The fourth compound is one or two of polymeric monomers and alcohol ether hydroxyl compound polymeric monomers, and the fourth compound can be neutralized by the salting agent.

[0019] By adopting the above technical solution, the use of reactants with medium to high boiling points can be adapted to the reaction temperature of this application. In addition, the reaction temperature at medium to high temperatures is conducive to reducing the molecular weight of the hydroxyacrylic acid dispersion, thereby achieving the goal of obtaining high solids and low viscosity characteristics of the hydroxyacrylic acid dispersion.

[0020] Choosing long-chain alkyl esters as the first compound is advantageous because, on the one hand, long-chain monomers have good chemical stability and are not easily hydrolyzed; on the other hand, the paint film polymerized from long-chain monomers has significant advantages in water resistance, chemical resistance, high gloss, and fullness. Selecting monomers without hydrolyzable ester bonds as the first compound is also advantageous because, on the one hand, the absence of ester bonds means no hydrolysis and good water resistance; on the other hand, the absence of ester bonds also significantly improves chemical resistance. The combination of polymerizable long-chain alkyl ester monomers and monomers without hydrolyzable ester bonds further enhances crosslinking, thereby improving the water and chemical resistance of the paint film.

[0021] The choice of lower alkyl methacrylates as the second compound balances the ratio of hard and soft monomers, the adhesion of the coating film, and other chemical properties. The shorter carbon chains of the lower alkyl esters result in a relatively low molecular weight of the entire resin, making neutralization and dispersion easier to reverse, which is beneficial for achieving a high solids and low viscosity dispersion. The active hydrogen-containing free radical polymerizable monomer is mainly used to introduce cross-linking groups, thereby enabling cross-linking and curing of the dispersion with the isocyanate curing agent.

[0022] The fourth compound is selected as an alcohol ether hydroxyl monomer. This is done for two reasons: firstly, to introduce hydroxyl groups into the dispersion, enabling the outer ends of the molecular chains to solidify with the isocyanate; secondly, the ether bond is a nonionic group, making the entire dispersion system more stable. The introduction of nonionic groups also provides excellent encapsulation and dispersibility for pigments in coatings. Since the fourth compound can be neutralized by salt-forming agents, its introduction into the dispersion introduces neutralizable acidic groups, thus forming a salt and resulting in excellent water dispersibility.

[0023] Optionally, the medium-to-high boiling point reactants are selected from any one or more of the following: ester oil, butyl acetate, (di)propylene glycol butyl ether, (di)ethylene glycol butyl ether, (di)propylene glycol methyl ether, (di)propylene glycol ethyl ether, and (di)ethylene glycol propyl ether.

[0024] Optionally, the first compound is selected from any one or more of dodecyl methacrylate, octadecyl methacrylate, dodecylfluoroheptyl methacrylate, methstyrene, cyclopentadiene, and dihydroxybutene.

[0025] Optionally, the second compound is selected from any one or more of methyl methacrylate, methyl isobutyl acrylate, butyl methacrylate, octyl methacrylate, ethyl methacrylate, ethylene glycol methacrylate, polyethylene glycol methacrylate, propylene glycol methacrylate, polypropylene glycol methacrylate, and butanediol methacrylate.

[0026] Optionally, the fourth compound is selected from any one or more of (meth)acrylic acid, (meth)acrylate phosphate, (meth)acrylamide-sulfonic acid, polyethylene glycol ether (meth)acrylate, polypropylene glycol ether (meth)acrylate, ethylene glycol monomethyl ether (meth)acrylate, and propylene glycol monomethyl ether (meth)acrylate.

[0027] Optionally, the initiator is a medium-to-high temperature initiator.

[0028] By adopting the above technical solution and selecting a medium-to-high temperature initiator, it is beneficial to stably initiate the formation of dispersions under medium-to-high temperature environments.

[0029] Optionally, the salt-forming agent is an alkaline salt-forming agent.

[0030] By adopting the above technical solution, the alkaline salt-forming agent can effectively neutralize and form salts from the fourth compound with acidic groups, which is beneficial for the dispersion to obtain excellent water dispersion effect.

[0031] Secondly, this application provides an application of a hydroxyacrylic acid dispersion, employing the following technical solution:

[0032] An application of a hydroxy acrylic dispersion, which, after being cured and crosslinked with isocyanate, forms a two-component waterborne polyurethane coating suitable for use in engineering machinery, containers, and rail transportation applications.

[0033] Thirdly, this application provides a method for preparing a hydroxyacrylic acid dispersion, which adopts the following technical solution:

[0034] A method for preparing a hydroxyacrylic acid dispersion includes the following steps:

[0035] S1. Weigh out the medium- and high-boiling-point reactants, the first compound, the second compound, the third compound, the fourth compound, the initiator, the salt-forming agent, and deionized water respectively. Place the medium- and high-boiling-point reactants in a reaction vessel and heat and stir.

[0036] S2. The first reactant, the second reactant, and the third reactant are respectively mixed with the initiator to obtain the first reaction mixture, the second reaction mixture, and the third reaction mixture;

[0037] S3, the first reaction mixture, the second reaction mixture, and the third reaction mixture are respectively connected to a peristaltic pump. The first reaction mixture, the second reaction mixture, and the third reaction mixture enter the reaction vessel under the drive of the peristaltic pump and continue to react.

[0038] S4. The fourth reactant is mixed with the initiator to obtain the fourth reaction mixture. The fourth reaction mixture is added dropwise to the reaction vessel and reacted at a constant temperature. A salt-forming agent and deionized water are added, the mixture is stirred and dispersed, filtered, and discharged to obtain a hydroxyacrylic acid dispersion.

[0039] By adopting the above technical solution, hydroxyacrylic acid dispersions are prepared by gradient polymerization. Unlike solution polymerization, which produces molecules with relatively simple and regular internal structures, gradient polymerization produces molecules with non-uniform monomers, resulting in a more complex and variable internal structure. This variable internal structure exhibits superior cohesive strength, tensile strength, and physicochemical properties, thus giving the hydroxyacrylic acid emulsion excellent physical and mechanical properties.

[0040] In summary, this application has the following beneficial effects:

[0041] 1. The hydroxyacrylic acid dispersion prepared by gradient polymerization in this application has the advantages of complex internal molecular structure and strong cohesion.

[0042] 2. The hydroxyacrylic acid dispersion prepared in this application has better physicochemical properties and the advantage of strong pigment wetting and dispersibility.

[0043] 3. The hydroxyacrylic acid dispersion prepared in this application has strong thermodynamic and kinetic stability.

[0044] 4. The hydroxyacrylic acid dispersion prepared in this application has the advantages of high decorative properties, excellent mechanical properties, and great market potential.

[0045] 5. The hydroxyacrylic acid dispersion prepared in this application has the advantages of relatively low cost, simple preparation process, easy control, and high economic value. Attached Figure Description

[0046] Figure 1 This is a schematic diagram of the solution-gradient polymerization process. Detailed Implementation

[0047] The present application will be further described in detail below with reference to the embodiments.

[0048] Example

[0049] Example 1

[0050] In one aspect, this application provides a hydroxy acrylic acid dispersion comprising a medium-to-high boiling point reactant, a first compound, a second compound, a third compound, a fourth compound, an initiator, a salt-forming agent, and deionized water, the specific quantities of which are shown in the table below.

[0051] Specifically, the medium-to-high boiling point reactant is ethylene glycol butyl ether;

[0052] The first compound includes dodecyl methacrylate and styrene;

[0053] The second compound comprises methyl isobutylene, butyl acrylate, and ethylene glycol methacrylate in a mass ratio of 5.35:4.45:2.85.

[0054] The third compound is half the mass of the second compound;

[0055] The fourth compound includes acrylic acid and ethylene glycol monomethyl ether acrylate;

[0056] The initiator is di-tert-butyl peroxide;

[0057] The salt-forming agent is dimethylethanolamine.

[0058] Secondly, this application provides an application of a hydroxy acrylic dispersion, which, after being cured and crosslinked with isocyanate, forms a two-component waterborne polyurethane coating that can be used in engineering machinery, containers, and rail transportation applications.

[0059] Thirdly, this application provides a method for preparing a hydroxyacrylic acid dispersion, comprising the following steps:

[0060] S1. Weigh out the medium-high boiling point reactants, the first compound, the second compound, the third compound, the fourth compound, the initiator, the salt-forming agent, and deionized water respectively. Place the medium-high boiling point reactants in a reaction vessel, heat to 140-150℃, and stir continuously.

[0061] S2. The first reactant, the second reactant, and the third reactant are mixed with an initiator (the initiator accounts for 4% of the mass of the reactants) to obtain a first reaction mixture, a second reaction mixture, and a third reaction mixture. The first reaction mixture is placed in a first container, the second reaction mixture is placed in a second container, and the third reaction mixture is placed in a third container.

[0062] S3, the first reaction mixture, the second reaction mixture, and the third reaction mixture are respectively connected to a peristaltic pump. The first reaction mixture, the second reaction mixture, and the third reaction mixture enter the reaction vessel under the drive of the peristaltic pump and continue to react.

[0063] Specifically, three peristaltic pumps are used. The suction end of the first peristaltic pump is placed into the first reaction mixture in the first container, and the discharge end is placed into the second reaction mixture in the second container. The suction end of the second peristaltic pump is placed into the second reaction mixture in the second container, and the discharge end is placed into the third reaction mixture in the third container. The suction end of the third peristaltic pump is placed into the third reaction mixture in the third container, and the discharge end is placed into the reaction vessel. When the temperature in the reaction vessel reaches a constant 140-145℃, all three peristaltic pumps are started simultaneously, and the flow rates are adjusted. The first, second, and third reaction mixtures are added dropwise at a uniform rate over 4-4.5 hours. After the addition is complete, the mixture is kept at this temperature for 0.5 hours. The first reaction mixture is labeled S1, the second reaction mixture is labeled S2, and the third reaction mixture is labeled S3.

[0064] S4. The fourth reactant is mixed with the initiator (the initiator accounts for 4% of the mass of the fourth reactant) to obtain the fourth reaction mixture. The fourth reaction mixture is added dropwise to the reaction vessel and the addition is completed within 1.5-2 hours. The reaction is kept at a constant temperature for 2 hours. The temperature is then lowered to 90°C, a salt-forming agent is added, and the mixture is stirred for 5-10 minutes. Deionized water is slowly added dropwise, and the mixture is stirred and dispersed for 1 hour. The mixture is then filtered and discharged to obtain the hydroxyacrylic acid dispersion.

[0065] Table 1 Composition of Example 1

[0066] Components weight / g Ethylene glycol butyl ether 7 Dodecyl methacrylate 1.2 styrene 3 Methyl isobutylene 8.025 Butyl acrylate 8.175 Ethylene glycol methacrylate 4.275 acrylic acid 1.23 Ethylene glycol monomethyl ether acrylate 5.07 Di-tert-butyl peroxide 1.26 Dimethylethanolamine 1.2 Deionized water margin

[0067] Example 2

[0068] The difference from Example 1 is as follows:

[0069] In one aspect, this application provides a hydroxy acrylic acid dispersion comprising a medium-to-high boiling point reactant, a first compound, a second compound, a third compound, a fourth compound, an initiator, a salt-forming agent, and deionized water, the specific quantities of which are shown in the table below.

[0070] Specifically, the medium-to-high boiling point reactant is propylene glycol butyl ether;

[0071] The first compound includes dodecyl methacrylate and methylstyrene;

[0072] The second compound comprises methyl isobutylene, octyl acrylate, and propylene glycol methacrylate in a mass ratio of 7.35:3.45:3.85.

[0073] The third compound is half the mass of the second compound;

[0074] The fourth compound includes methacrylic acid and ethylene glycol monomethyl ether acrylate;

[0075] The initiator is di-tert-butyl peroxide;

[0076] The salt-forming agent is triethylamine.

[0077] Table 2 Composition of Example 2

[0078]

[0079]

[0080] Example 3

[0081] The difference from Example 1 is as follows:

[0082] In one aspect, this application provides a hydroxy acrylic acid dispersion comprising a medium-to-high boiling point reactant, a first compound, a second compound, a third compound, a fourth compound, an initiator, a salt-forming agent, and deionized water, the specific quantities of which are shown in the table below.

[0083] Specifically, the medium-to-high boiling point reactant is dipropylene glycol butyl ether;

[0084] The first compound includes octadecyl methacrylate and styrene;

[0085] The second compound comprises methyl methacrylate, ethyl acrylate, and propylene glycol acrylate in a mass ratio of 7.35:3.45:3.85.

[0086] The third compound is half the mass of the second compound;

[0087] The fourth compound includes phosphate methacrylate and polypropylene glycol monomethyl ether acrylate;

[0088] The initiator is di-tert-butyl peroxide;

[0089] The salt-forming agent is triethanolamine.

[0090] Table 3 Composition of Example 3

[0091]

[0092]

[0093] Example 4

[0094] The difference from Example 1 is as follows:

[0095] In one aspect, this application provides a hydroxy acrylic acid dispersion comprising a medium-to-high boiling point reactant, a first compound, a second compound, a third compound, a fourth compound, an initiator, a salt-forming agent, and deionized water, the specific quantities of which are shown in the table below.

[0096] Specifically, the medium-to-high boiling point reactant is dipropylene glycol butyl ether;

[0097] The first compound includes dodecyl methacrylate and styrene;

[0098] The second compound comprises methyl methacrylate, ethyl methacrylate, and polypropylene glycol acrylate in a mass ratio of 7.35:3.45:3.85.

[0099] The third compound is half the mass of the second compound;

[0100] The fourth compound includes phosphate acrylate and polypropylene glycol monomethyl ether acrylate;

[0101] The initiator is di-tert-butyl peroxide;

[0102] The salt-forming agent is triethanolamine.

[0103] Table 4 Composition of Example 4

[0104]

[0105]

[0106] Comparative Example 1

[0107] In a 1000ml four-necked flask equipped with a reflux device, add 23.9g of S-100 solvent and 23.9g of ethylene glycol butyl ether. Heat to 152℃, then add 11.6g of butyl methacrylate, 30.85g of butyl acrylate, 40.25g of methyl methacrylate, 20g of styrene, 4.94g of isobornyl methacrylate, 33.45g of hydroxyethyl methacrylate, and 4.3g of di-tert-amyl peroxide. The addition is completed dropwise over 4.5 hours. After the addition is complete, maintain the temperature for half an hour, then add the second portion of monomers dropwise. Add 17.1g butyl acrylate, 21.75g ​​methyl methacrylate, 6.2g acrylic acid, 23.8g hydroxyethyl methacrylate, 1.82g isobornyl methacrylate, and 3.35g di-tert-amyl peroxide, and add them dropwise over 1.5 hours. Then add 0.9g di-tert-amyl peroxide, keep warm for 1 hour, cool to 80℃, add 6g dimethylethanolamine to neutralize, add 231.15g water, stir and disperse for 2 hours, and discharge for testing.

[0108] Performance testing

[0109] (1) Viscosity test: The viscosity of the dispersions in each embodiment was measured using a rotational viscometer, and the solid content of the dispersions was measured by baking at 160℃ for 0.5h.

[0110] (2) The hydroxy acrylic dispersions in Comparative Example 1 and Example 1 were crosslinked with a polyisocyanate curing agent to prepare a paint, and the various properties were measured.

[0111] Table 5

[0112]

[0113] Table 6

[0114]

[0115]

[0116] By comparing Tables 5 and 6, we can find that:

[0117] 1. Combining Examples 1-4, it can be found that the hydroxyl acrylic acid dispersions prepared in Examples 1-4 all have advantages such as high hydroxyl content, low viscosity, high hydroxyl value, high fullness, and high chemical resistance. Among them, considering the comprehensive production process technology and economic benefits, the formulation in Example 1 has the best economic benefits.

[0118] 2. Combining Example 1 and Comparative Example 1, it can be found that the hydroxyl acrylic dispersion prepared in this invention has significant advantages in terms of activation period, solid content, hydroxyl content, fullness, chemical resistance and water resistance. Furthermore, this type of dispersion can effectively solve problems such as chemical resistance and water resistance, and will not affect the overall storage stability of the resin. It has a very broad market application prospect.

[0119] This specific embodiment is merely an explanation of this application and is not intended to limit it. After reading this specification, those skilled in the art can make modifications to this embodiment without contributing any inventive step, but such modifications are protected by patent law as long as they fall within the scope of the claims of this application.

Claims

1. A hydroxyacrylic acid dispersion, characterized in that, Including the following percentages by weight of raw materials: 7-8% of medium- to high-boiling-point reactants; The first compound was 4.2-6.3%; The second compound was 13.65-15.75%; The third compound was 13.65%–5.76%; The fourth compound was 6.3-8.4%; Initiator concentration: 1.26-1.68%; Salt-forming agent 1.2-1.4%; Deionized water balance; The medium-to-high boiling point reactants are polar or non-polar reactive compounds with boiling points above 140°C; The first compound is one or two of long-chain alkyl ester polymerizable monomers and polymerizable monomers without hydrolyzable ester bonds; The second compound is one or two of a lower alkyl methacrylate and a free radical polymerizable monomer containing active hydrogen. The third compound is 50% by weight of the second compound; The fourth compound is one or two of polymeric monomers and alcohol ether hydroxyl compound polymeric monomers; the fourth compound can be neutralized by the salting agent; The method for preparing the hydroxyacrylic acid dispersion includes the following steps: S1. Weigh out the medium- and high-boiling-point reactants, the first compound, the second compound, the third compound, the fourth compound, the initiator, the salt-forming agent, and deionized water respectively. Place the medium- and high-boiling-point reactants in a reaction vessel and heat and stir. S2. The first reactant, the second reactant, and the third reactant are respectively mixed with the initiator to obtain the first reaction mixture, the second reaction mixture, and the third reaction mixture; S3, the first reaction mixture, the second reaction mixture, and the third reaction mixture are respectively connected to a peristaltic pump. The first reaction mixture, the second reaction mixture, and the third reaction mixture enter the reaction vessel under the drive of the peristaltic pump and continue to react. S4. The fourth reactant is mixed with the initiator to obtain the fourth reaction mixture. The fourth reaction mixture is added dropwise to the reaction vessel and reacted at a constant temperature. A salt-forming agent and deionized water are added, the mixture is stirred and dispersed, filtered, and discharged to obtain a hydroxyacrylic acid dispersion.

2. The hydroxyacrylic acid dispersion according to claim 1, characterized in that: The medium-to-high boiling point reactants are selected from any one or more of the following: ester oil, butyl acetate, (di) propylene glycol butyl ether, (di) ethylene glycol butyl ether, (di) propylene glycol methyl ether, (di) propylene glycol ethyl ether, and (di) ethylene glycol propyl ether.

3. The hydroxyl acrylic acid dispersion according to claim 2, characterized in that: The first compound is selected from any one or more of (meth)acrylate, (meth)octadecyl acrylate, (meth)acrylate dodecylfluoroheptyl acrylate, (meth)styrene, cyclopentadiene, and dihydroxybutene.

4. The hydroxy acrylic acid dispersion according to claim 3, characterized in that: The second compound is selected from any one or more of methyl methacrylate, methyl isobutyl acrylate, butyl methacrylate, octyl methacrylate, ethyl methacrylate, ethylene glycol methacrylate, polyethylene glycol methacrylate, propylene glycol methacrylate, polypropylene glycol methacrylate, and butanediol methacrylate.

5. The hydroxyacrylic acid dispersion according to claim 4, characterized in that: The fourth compound is selected from any one or more of (meth)acrylic acid, (meth)acrylate phosphate, (meth)acrylamide-sulfonic acid, polyethylene glycol ether (meth)acrylate, polypropylene glycol ether (meth)acrylate, ethylene glycol monomethyl ether (meth)acrylate, and propylene glycol monomethyl ether (meth)acrylate.

6. The hydroxy acrylic acid dispersion according to claim 5, characterized in that: The initiator is a medium-to-high temperature initiator.

7. The hydroxyacrylic acid dispersion according to claim 1, characterized in that: The salt-forming agent is an alkaline salt-forming agent.

8. The application of the hydroxyacrylic acid dispersion according to any one of claims 1-7, characterized in that: Two-component waterborne polyurethane coatings, after being cured and crosslinked with isocyanate, can be used in engineering machinery, containers, and rail transportation applications.

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