Hydroxyl acrylic dispersion, application and preparation method thereof

Abstract

The invention relates to the technical field of water-based paint, and particularly discloses a hydroxy acrylic dispersion, application and a preparation method thereof. The hydroxy acrylic dispersion comprises the following raw materials in percentage by mass: medium and high boiling point reactants; 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 two of a long-carbon-chain alkyl ester polymerizable monomer and a polymerizable monomer without hydrolyzable ester bonds; the second compound is one or two of methacrylic acid lower alkyl ester and an active hydrogen-containing free radical polymerizable monomer; and the fourth compound is one or two of a polymeric monomer and an alcohol ether hydroxyl compound polymeric monomer. The hydroxy acrylic dispersion can be used for water-based paint, and has the advantages of excellent mechanical and physical properties, excellent chemical resistance and the like.

Description

Technical Field

[0001] The present application relates to the technical field of water-based coatings, and more specifically, to a hydroxy acrylic dispersion, an application thereof, and a preparation method thereof. Background Art

[0002] Two-component polyurethane is a polyurethane resin formed by curing and cross-linking a compound containing a hydroxyl functional group with a polyisocyanate curing agent. Among them, curing and cross-linking using a hydroxypropyl dispersion and a polyisocyanate curing agent is more common. Since two-component polyurethane has received more and more attention in industrial production and its production scale is growing, there is an increasing demand for the use of hydroxylated acrylic dispersions to prepare two-component polyurethane self-drying paints.

[0003] At present, the preparation technology of water-based hydroxy acrylic acid dispersion mainly adopts solution polymerization, and finally neutralizes by adding amine neutralizers and disperses in water to achieve water-based. This technology is currently the main preparation technology, and the technical method is also quite mature. The dispersion prepared by this method has received good evaluation and wide application in terms of performance, industrialization and end customers. However, the hydroxy acrylic dispersion prepared by solution polymerization also has problems such as general physical and mechanical properties, poor chemical resistance and single molecular internal structure. Summary of the invention

[0004] In order to improve the mechanical and physical properties, weather resistance and single molecular internal structure of the base acrylic dispersion, the present application provides a hydroxy acrylic dispersion, application and preparation method thereof, using the following technical solution:

[0005] In a first aspect, the present application provides a hydroxylated acrylic dispersion, comprising the following raw materials in percentage by weight:

[0006] Medium-high boiling point reactants 7-8%;

[0007] First compound 4.2-6.3%;

[0008] The second compound 13.65-15.75%;

[0009] The third compound 13.65-5.76%;

[0010] The fourth compound 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-high boiling point reactant is a polar or non-polar reaction compound with a boiling point above 140°C;

[0015] The first compound is one or both of a long carbon chain alkyl ester polymerizable monomer and a polymerizable monomer without a hydrolyzable ester bond;

[0016] The second compound is one or both 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 both of a polymerized monomer and an alcohol ether hydroxyl compound polymerized monomer, and the fourth compound can be neutralized by the salt-forming agent.

[0019] By adopting the above technical scheme, the use of medium-high boiling point reactants can adapt to the reaction temperature of the present application. In addition, the reaction temperature at medium-high temperature is conducive to reducing the molecular weight in the hydroxylated acrylic acid dispersion, thereby achieving the purpose of obtaining high solid and low viscosity properties of the hydroxylated acrylic acid dispersion.

[0020] Selecting long-chain alkyl ester as the first compound, on the one hand, the long carbon acid monomer has good chemical stability and is not easy to hydrolyze; on the other hand, the paint film polymerized by the long-chain monomer has obvious advantages in water resistance, chemical resistance, high gloss and fullness; selecting a polymerizable monomer that does not contain a hydrolyzable ester bond as the first compound, on the one hand, the absence of an ester bond means that hydrolysis does not occur and has good water resistance; on the other hand, the absence of an ester bond will also greatly improve the chemical resistance. The combination of a long-chain alkyl ester polymerizable monomer and a polymerizable monomer that does not contain a hydrolyzable ester bond can further improve crosslinking to improve the water resistance and chemical resistance of the paint film.

[0021] Selecting low alkyl (meth)acrylate as the second compound takes into account the ratio of soft and hard monomers, adhesion of the paint film and other chemical properties. The low alkyl ester has a shorter carbon chain, which makes the molecular weight of the entire resin of the second compound relatively low, and the neutralization dispersion is easy to reverse, which is conducive to achieving high solid and low viscosity of the dispersion. The active hydrogen-containing free radical polymerizable monomer is mainly to introduce exchange groups, so as to achieve cross-linking and curing of the dispersion with the isocyanate curing agent.

[0022] The fourth compound uses an alcohol ether hydroxyl compound polymerization monomer. On the one hand, it is to introduce hydroxyl groups into the dispersion so that the outer ends of the molecular chains of the dispersion can be cured with isocyanate; on the other hand, the ether bond is a non-ionic group, which makes the entire dispersion system more stable. The introduction of non-ions also has excellent encapsulation and dispersibility for pigments in coatings. Since the fourth compound can be neutralized by a salt-forming agent, the fourth compound is introduced into the dispersion, and a neutralizable acidic group is introduced into the dispersion, thereby forming a salt, so that the dispersion has excellent water dispersibility.

[0023] Optionally, the medium-to-high boiling point reactant is selected from any one or more of solvent 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 (meth)acrylate, octadecyl (meth)acrylate, dodecafluoroheptyl (meth)acrylate, (methyl)styrene, cyclopentadiene, and dihydroxybutene.

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

[0026] Optionally, the fourth compound is selected from any one or more of (meth)acrylic acid, (meth)acrylic acid 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, medium-high temperature initiators are preferred, which is conducive to stable initiation and formation of dispersions under medium-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 the fourth compound having an acidic group to form a salt, which is beneficial for the dispersion to obtain an excellent water dispersion effect.

[0031] In a second aspect, the present application provides an application of a hydroxylated acrylic acid dispersion, using the following technical solution:

[0032] An application of a hydroxy acrylic dispersion. A two-component polyurethane water-based coating obtained by curing and cross-linking the dispersion with isocyanate can be used in the fields of engineering machinery, containers and rail transportation.

[0033] In a third aspect, the present application provides a method for preparing a hydroxylated acrylic acid dispersion, using the following technical solution:

[0034] A method for preparing a hydroxylated acrylic acid dispersion comprises the following steps:

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

[0036] S2, mixing the first reactant, the second reactant, and the third reactant with an initiator respectively to obtain a first reaction mixture, a second reaction mixture, and a third reaction mixture;

[0037] S3, the first reaction mixture, the second reaction mixture and the third reaction mixture are connected to the peristaltic pumps respectively, and the first reaction mixture, the second reaction mixture and the third reaction mixture enter the reaction container under the drive of the peristaltic pumps for continuous reaction;

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

[0039] By adopting the above technical scheme, gradient polymerization and method are used to realize the preparation of hydroxy acrylic dispersion. Different from the relatively simple and regular internal structure of the molecules prepared by solution polymerization, the polymerization monomers inside the molecules prepared by gradient polymerization are not uniform, which makes the internal structure of the molecules more complex and changeable. The changeable internal structure has better cohesion, tensile strength and better physical and chemical properties. Therefore, the hydroxy acrylic emulsion obtains excellent physical and mechanical properties.

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

[0041] 1. The hydroxylated acrylic acid dispersion prepared by gradient polymerization in the present application has the advantages of complex internal molecular structure and strong cohesive force.

[0042] 2. The hydroxylated acrylic dispersion prepared in the present application has better physical and chemical properties and has the advantage of strong pigment wetting and dispersibility.

[0043] 3. The hydroxylated acrylic acid dispersion prepared in the present application has strong thermodynamic and kinetic stability.

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

[0045] 5. The hydroxylated acrylic acid dispersion prepared in the present application has the advantages of relatively low cost, simple preparation process, easy control and high economic value. BRIEF DESCRIPTION OF THE DRAWINGS

[0046] Figure 1 It is a schematic diagram of the solution-gradient polymerization process flow. DETAILED DESCRIPTION

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

[0048] Example

[0049] Example 1

[0050] In a first aspect, the present application provides a hydroxy acrylic dispersion comprising a medium-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, and the specific masses are shown in the table below.

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

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

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

[0054] The third compound is 1 / 2 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] In a second aspect, the present application provides an application of a hydroxylated acrylic dispersion, and the two-component polyurethane water-based coating obtained by curing and cross-linking the dispersion with isocyanate can be used in the fields of engineering machinery, containers and rail transit applications.

[0059] In a third aspect, the present application provides a method for preparing a hydroxylated acrylic acid dispersion, comprising the following steps:

[0060] S1. Weigh 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 container, heat to 140-150° C., and continue stirring;

[0061] S2, respectively mixing the first reactant, the second reactant, and the third reactant with an initiator (the mass ratio of the initiator to the reactants is 4%) to obtain a first reaction mixture, a second reaction mixture, and a third reaction mixture, wherein 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 connected to the peristaltic pumps respectively, and the first reaction mixture, the second reaction mixture and the third reaction mixture enter the reaction container under the drive of the peristaltic pumps for continuous reaction;

[0063] Specifically, there are three peristaltic pumps. The pumping end of the first peristaltic pump is placed in the first reaction mixture of the first container, and the discharging end is placed in the second reaction mixture of the second container; the pumping end of the second peristaltic pump is placed in the second reaction mixture of the second container, and the discharging end is placed in the third reaction mixture of the third container; the pumping end of the third peristaltic pump is placed in the third reaction mixture of the third container, and the discharging end is placed in the reaction container. When the temperature in the reaction container is constant at 140-145°C, start the three peristaltic pumps at the same time, adjust the flow rate, and uniformly add the first reaction mixture, the second reaction mixture, and the third reaction mixture within 4-4.5 hours. After the addition is completed, keep warm for 0.5 hours. The first reaction mixture is marked as S1, the second reaction mixture is marked as S2, and the third reaction mixture is marked as S3.

[0064] S4. The fourth reactant is mixed with an initiator (the mass ratio of the initiator to the fourth reactant is 4%) to obtain a fourth reaction mixture, and the fourth reaction mixture is added dropwise to a reaction container. The addition is completed within 1.5-2 hours, and the reaction is carried out at a constant temperature for 2 hours. The temperature is 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 filtered and discharged to obtain a hydroxy acrylic 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 methacrylate 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:

[0069] In a first aspect, the present application provides a hydroxy acrylic dispersion comprising a medium-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, and the specific masses are shown in the table below.

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

[0071] The first compound includes dodecyl methacrylate and methyl styrene;

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

[0073] The third compound is 1 / 2 the mass of the second compound;

[0074] a fourth compound comprising 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 Example 2 Composition

[0078]

[0079]

[0080] Example 3

[0081] The difference from Example 1 is:

[0082] In a first aspect, the present application provides a hydroxy acrylic dispersion comprising a medium-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, and the specific masses are shown in the table below.

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

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

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

[0086] The third compound is 1 / 2 the mass of the second compound;

[0087] The fourth compound includes methacrylic acid phosphate 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:

[0095] In a first aspect, the present application provides a hydroxy acrylic dispersion comprising a medium-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, and the specific masses are shown in the table below.

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

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

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

[0099] The third compound is 1 / 2 the mass of the second compound;

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

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

[0102] The salt-forming agent is triethanolamine.

[0103] Table 4 Example 4 Composition

[0104]

[0105]

[0106] Comparative Example 1

[0107] In a 1000ml four-necked flask equipped with a reflux device, add 23.9g S-100 solvent and 23.9g ethylene glycol butyl ether, raise the temperature to 152°C, add 11.6g butyl methacrylate, 30.85g butyl acrylate, 40.25g methyl methacrylate, 20g styrene, 4.94g isobornyl methacrylate, 33.45g hydroxyethyl methacrylate, 4.3g di-tert-amyl peroxide and add dropwise within 4.5h. After the addition is completed, keep warm for half an hour, and add the second part of the monomer dropwise. , add 17.1g butyl acrylate, 21.75g ​​methyl methacrylate, 6.2g acrylic acid, 23.8g hydroxyethyl methacrylate, 1.82g isobornyl methacrylate, 3.35g di-tert-amyl peroxide and drip it within 1.5h, add 0.9g di-tert-amyl peroxide, keep warm for 1h, cool to 80℃, add 6g dimethylethanolamine to neutralize, add 231.15g water and stir to disperse for 2h, discharge the material and test.

[0108] Performance testing

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

[0110] (2) The hydroxylated acrylic dispersions in Comparative Example 1 and Example 1 were cross-linked with a polyisocyanate curing agent to prepare paints, and various properties were measured.

[0111] Table 5

[0112]

[0113] Table 6

[0114]

[0115]

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

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

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

[0119] This specific embodiment is merely an explanation of the present application and is not a limitation of the present application. After reading this specification, those skilled in the art may make modifications to the present embodiment without any creative contribution as needed, but such modifications are protected by the patent law as long as they are within the scope of the claims of the present application.

Claims

1. A hydroxylated acrylic dispersion, characterized in that: The following raw materials are included in mass percentage: Medium and high boiling point reactants 7-8%; First compound 4.2-6.3%; The second compound 13.65-15.75%; The third compound 13.65-5.76%; The fourth compound 6.3-8.4%; Initiator 1.26-1.68%; Salt-forming agent 1.2-1.4%; Deionized water balance; The medium-high boiling point reactant is a polar or non-polar reaction compound with a boiling point above 140°C; The first compound is one or both of a long carbon chain alkyl ester polymerizable monomer and a polymerizable monomer without a hydrolyzable ester bond; The second compound is one or both 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 both of a polymerizable monomer and an alcohol ether hydroxyl compound polymerizable monomer; the fourth compound can be neutralized by the salt-forming agent.

2. A hydroxylated acrylic dispersion according to claim 1, characterized in that: The medium-high boiling point reactants are selected from any one or more of agent 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. A hydroxylated acrylic dispersion according to claim 2, characterized in that: The first compound is selected from any one or more of dodecyl (meth)acrylate, octadecyl (meth)acrylate, dodecafluoroheptyl (meth)acrylate, (methyl)styrene, cyclopentadiene, and dihydroxybutene.

4. A hydroxylated acrylic dispersion according to claim 3, characterized in that: The second compound is selected from any one or more of methyl methacrylate, methyl methacrylate, butyl (meth)acrylate, octyl (meth)acrylate, ethyl (meth)acrylate, ethylene glycol (meth)acrylate, polyethylene glycol (meth)acrylate, propylene glycol (meth)acrylate, polypropylene glycol (meth)acrylate, and butylene glycol (meth)acrylate.

5. A hydroxylated acrylic dispersion according to claim 4, characterized in that: The fourth compound is selected from any one or more of (meth)acrylic acid, (meth)acrylic acid 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. A hydroxylated acrylic dispersion according to claim 5, characterized in that: The initiator is a medium-high temperature initiator.

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

8. The use of a hydroxy acrylic acid dispersion according to any one of claims 1 to 7, characterized in that: The two-component polyurethane water-based coating obtained by curing and cross-linking this type of dispersion with isocyanate can be used in engineering machinery, containers and rail transportation applications.

9. The method for preparing a hydroxy acrylic acid dispersion according to any one of claims 1 to 7, characterized in that: The following steps are involved: S1. Weigh medium-high boiling point reactants, the first compound, the second compound, the third compound, the fourth compound, an initiator, a salt-forming agent and deionized water respectively, place the medium-high boiling point reactants in a reaction container, and heat and stir; S2, mixing the first reactant, the second reactant, and the third reactant with an initiator respectively to obtain a first reaction mixture, a second reaction mixture, and a third reaction mixture; S3, the first reaction mixture, the second reaction mixture and the third reaction mixture are respectively connected to the peristaltic pumps, and the first reaction mixture, the second reaction mixture and the third reaction mixture enter the reaction container under the drive of the peristaltic pumps for continuous reaction; S4. The fourth reactant is mixed with the initiator to obtain a fourth reaction mixture, and the fourth reaction mixture is added dropwise to a reaction container for constant temperature reaction, and a salt-forming agent and deionized water are added. The mixture is stirred and dispersed, filtered, and discharged to obtain a hydroxy acrylic acid dispersion.

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