A solvent-free hydroxyl acrylic dispersion, its preparation method and application

Abstract

The application discloses a kind of solventless hydroxyl acrylic dispersion and its preparation method and application, belong to coating technical field. Including the following steps: maleic anhydride oil acid and oleic acid are mixed in reaction vessel, temperature is raised to 150~155 DEG C, glycidyl methacrylate, acrylic hydroxyl monomer, other acrylic monomer, initiator are mixed uniformly, 4~5h are evenly dropped into reaction vessel, keep warm 1h, and the material A is obtained;Material A is cooled to 80 DEG C and neutralizing agent is added, and the material B is obtained;Material B is dispersed into deionized water, and the solventless hydroxyl acrylic dispersion is obtained.The hydroxyl acrylic dispersion prepared by the application has high solid content and low viscosity, and has excellent water resistance, chemical resistance, gloss, and excellent anti-flash rust ability when applied to coating.

Description

Technical Field

[0001] This invention belongs to the field of coating technology, specifically relating to a solvent-free hydroxy acrylic dispersion, its preparation method, and its application. Background Technology

[0002] With increasingly stringent environmental protection requirements and a growing demand for green and environmentally friendly products, water-based coatings have become an important development direction for the coatings industry. Among them, two-component water-based hydroxy acrylic dispersions are widely used in metal, wood, and industrial fields due to their high gloss, excellent weather resistance, and color retention.

[0003] However, traditional hydroxyacrylic acid dispersions still have some problems. First, the preparation of hydroxyacrylic acid dispersions using conventional solution polymerization methods usually requires the use of organic solvents, which not only increases the solvent content but may also pose potential hazards to the environment and human health. Second, traditional dispersions generally suffer from low solids content and high viscosity, and their performance indicators such as water resistance, chemical resistance, and gloss required for special applications all need to be improved.

[0004] In existing technologies, improving the performance of dispersions by introducing different monomer structures and modifying preparation processes is an important method. However, how to prepare hydroxy acrylic dispersions with high solid content, low viscosity, good water resistance, and high gloss without using organic solvents, while simultaneously meeting environmental requirements and application performance, remains a key research focus and challenge. Currently, solvent-free or low-solvent-content hydroxy acrylic dispersions are typically synthesized using glycidyl tert-carbonate, but this method is costly and results in slightly poorer chemical resistance in coatings. Summary of the Invention

[0005] In order to overcome the problems of environmental pollution, low solid content, high viscosity, poor water resistance, poor chemical resistance and insufficient gloss caused by the use of organic solvents in existing hydroxy acrylic dispersions, this invention provides a solvent-free hydroxy acrylic dispersion, its preparation method and application.

[0006] To achieve the above objectives, the technical solution adopted by the present invention is as follows:

[0007] In one aspect, the present invention provides a method for preparing a solvent-free hydroxyacrylic acid dispersion, comprising the following steps:

[0008] (1) Add maleic anhydride, oleic acid and oleic acid to a reaction vessel and mix. Heat to 150-155°C. Mix glycidyl methacrylate, acrylic hydroxyl monomers, other acrylic monomers and initiator evenly. Add the mixture dropwise to the reaction vessel at a uniform rate for 4-5 hours. Keep warm for 1 hour to obtain material A.

[0009] (2) Cool the material A to 80°C and add a neutralizing agent to obtain material B;

[0010] (3) Disperse the material B in deionized water to obtain the solvent-free hydroxy acrylic acid dispersion.

[0011] As a further embodiment of the present invention, the weight parts of each component are as follows: maleic anhydride oleic acid 20-60 parts, oleic acid 60-150 parts, glycidyl methacrylate 30-120 parts, acrylic hydroxy monomer 0-80 parts, other acrylic monomers 200-400 parts, initiator 12-25 parts, neutralizer 15-30 parts, and deionized water 500-700 parts.

[0012] As a further embodiment of the present invention, the method for preparing the maleic anhydride oleic acid includes: mixing maleic anhydride and linolenic acid in a molar ratio of 1:1 to 3:1, heating to 210 to 250°C, and reacting until there is no reflux to obtain the maleic anhydride oleic acid.

[0013] As a further embodiment of the present invention: the oleic acid is an unsaturated fatty acid selected from soybean oil acid, linolenic acid, tung oil acid, and dehydrated ricinoleic acid;

[0014] And / or, the acrylic hydroxy monomer is selected from at least one of hydroxyethyl acrylate, hydroxyethyl methacrylate, hydroxypropyl acrylate, and hydroxypropyl methacrylate;

[0015] And / or, the other acrylic monomers are selected from at least two of butyl acrylate, butyl methacrylate, styrene, isobornyl methacrylate, methyl methacrylate, and acrylic acid;

[0016] And / or, the initiator is selected from one or two of tert-butyl peroxide, di-tert-butyl peroxide, di-tert-pentyl peroxide, cumene hydroperoxide, and tert-butyl peroxide (2-ethylhexanoate).

[0017] As a further embodiment of the present invention: the neutralizing agent is selected from at least one of N,N-dimethylethanolamine, triethylamine, N-ethylmorpholine, ammonia, and AMP95 (2-amino-2-methyl-1-propanol).

[0018] In a second aspect, the present invention provides a solvent-free hydroxyacrylic acid dispersion, which is prepared by the above-described method for preparing a solvent-free hydroxyacrylic acid dispersion.

[0019] In a third aspect, the present invention provides the application of the above-described solvent-free hydroxy acrylic dispersion in the field of waterborne coatings.

[0020] The beneficial effects of this invention are as follows:

[0021] (1) This invention uses oleic acid and maleic anhydride-based oleic acid to synthesize acrylic dispersions, which successfully avoids the use of organic solvents, reduces potential harm to the environment and human health, and meets increasingly stringent environmental protection requirements.

[0022] (2) The dispersion of the present invention contains glycidyl methacrylate. Through the reaction of carboxyl groups and epoxy groups in the base solvent, as well as subsequent amine neutralization and hydration treatment, the solid content of the dispersion is significantly increased and the viscosity is reduced, thereby improving the economy and workability of the coating.

[0023] (3) When the dispersion of the present invention is used to make two-component coatings, it not only crosslinks through the reaction of hydroxyl groups with isocyanates, but also utilizes oil functional groups for air oxidation crosslinking to form a more robust network structure, thereby improving the coating's water resistance (especially initial water resistance) and chemical resistance. In addition, the resulting coating has higher gloss and excellent flash rust resistance, and its overall performance is superior to traditional products. Detailed Implementation

[0024] The present invention is further illustrated below by way of examples, but these examples do not limit the invention to the scope of the embodiments described. Experimental methods in the following examples, unless otherwise specified, were performed according to conventional methods and conditions, or as selected according to the product instructions. Furthermore, all reagents and raw materials used in this invention are commercially available. Detailed information on each component is as follows:

[0025] Linoleic acid: purchased from Anhui Ruifende Oil & Fat Deep Processing Co., Ltd. Maleic anhydride: purchased from Maclean's Reagent Company. N,N-Dimethylethanolamine: purchased from BASF. Di-tert-amyl peroxide: purchased from Dongguan Yongzheng Chemical Co., Ltd. Methyl methacrylate, styrene, butyl acrylate, hydroxyethyl methacrylate, glycidyl methacrylate, acrylic acid: purchased from Huayi Chemical Co., Ltd. Bayhydur 2655 curing agent: purchased from Covestro. Thickener 0620: purchased from Matsuo Trading Co. BYK 346: purchased from BYK Chemical Co. Tego 760W, Tego 902W: purchased from Tego Co. Ethylene glycol butyl ether, dipropylene glycol butyl ether, propylene glycol methyl ether acetate: purchased from Dow Chemical Co. Titanium dioxide R996: purchased from Baililian. Zinc phosphate: purchased from Guangxi Xinjing Technology Co.

[0026] Example 1

[0027] A. The preparation method of maleic anhydride oleic acid includes the following steps:

[0028] 279 parts of linoleic acid were added to the flask, the temperature was raised to 220°C, 147 parts of maleic anhydride were added, and the reaction continued until there was no reflux. After cooling, maleic anhydride oleic acid was obtained, which is an oily, low-viscosity liquid.

[0029] B. A method for preparing a solvent-free hydroxyacrylic acid dispersion, comprising the following steps:

[0030] 30 parts maleic anhydride and 90 parts linoleic acid were added to a reaction vessel, and the temperature was raised to 150-155℃. 112 parts butyl acrylate, 78 parts hydroxyethyl methacrylate, 107 parts methyl methacrylate, 40 parts styrene, 40 parts glycidyl methacrylate, and 17 parts di-tert-amyl peroxide were mixed evenly and added dropwise to the reaction vessel over a 4-hour period. The reaction was maintained at this temperature for 1 hour. The temperature was then lowered to 80℃, and 25 parts of the neutralizing agent N,N-dimethylethanolamine were added and dispersed in 560 parts of deionized water. The mixture was then cooled to room temperature to obtain a hydroxyacrylic acid dispersion.

[0031] Example 2

[0032] A. The preparation method of maleic anhydride oleic acid includes the following steps:

[0033] 279 parts of linoleic acid were added to the flask, the temperature was raised to 220°C, 99 parts of maleic anhydride were added, and the reaction continued until there was no reflux. After cooling, maleic anhydride oleic acid was obtained, which is an oily, low-viscosity liquid.

[0034] B. A method for preparing a solvent-free hydroxyacrylic acid dispersion, comprising the following steps:

[0035] 30 parts maleic anhydride and 110 parts linoleic acid were added to a reaction vessel, and the temperature was raised to 150-155℃. 112 parts butyl acrylate, 70 parts hydroxyethyl methacrylate, 107 parts methyl methacrylate, 40 parts styrene, 55 parts glycidyl methacrylate, and 19 parts di-tert-amyl peroxide were mixed thoroughly and added dropwise to the reaction vessel over 4.5 hours. The reaction was maintained at this temperature for 1 hour. The temperature was then lowered to 80℃, and 22 parts of the neutralizing agent N,N-dimethylethanolamine were added and dispersed in 600 parts of deionized water. The mixture was then cooled to room temperature to obtain a hydroxyacrylic acid dispersion.

[0036] Example 3

[0037] A. The preparation method of maleic anhydride oleic acid includes the following steps:

[0038] 279 parts of linoleic acid were added to a flask, the temperature was raised to 220°C, and 290 parts of maleic anhydride were added. The reaction continued until there was no reflux. After cooling, maleic anhydride oleic acid was obtained as an oily, low-viscosity liquid.

[0039] B. A method for preparing a solvent-free hydroxyacrylic acid dispersion, comprising the following steps:

[0040] 25 parts maleic anhydride and 110 parts linoleic acid were added to a reaction vessel, and the temperature was raised to 150-155℃. 90 parts butyl acrylate, 50 parts hydroxyethyl methacrylate, 107 parts methyl methacrylate, 40 parts styrene, 84 parts glycidyl methacrylate, and 14 parts di-tert-amyl peroxide were mixed thoroughly and added dropwise to the reaction vessel over a 5-hour period. The mixture was kept at this temperature for 1 hour. The temperature was then lowered to 80℃, and 19 parts N,N-dimethylethanolamine (a neutralizing agent) were added and dispersed in 600 parts deionized water. The mixture was then cooled to room temperature to obtain a hydroxyacrylic acid dispersion.

[0041] Example 4

[0042] A. The preparation method of maleic anhydride oleic acid includes the following steps:

[0043] 279 parts of linoleic acid were added to a flask, the temperature was raised to 240°C, and 150 parts of maleic anhydride were added. The reaction continued until there was no reflux. After cooling, maleic anhydride oleic acid was obtained as an oily, low-viscosity liquid.

[0044] B. A method for preparing a solvent-free hydroxyacrylic acid dispersion, comprising the following steps:

[0045] 35 parts maleic anhydride and 140 parts linoleic acid were added to a reaction vessel, and the temperature was raised to 150-155°C. 80 parts butyl acrylate, 90 parts methyl methacrylate, 15 parts acrylic acid, 40 parts styrene, 110 parts glycidyl methacrylate, and 14 parts di-tert-amyl peroxide were mixed thoroughly and added dropwise to the reaction vessel over a 5-hour period. The mixture was kept at this temperature for 1 hour. The temperature was then lowered to 80°C, and 19 parts N,N-dimethylethanolamine (a neutralizing agent) were added and dispersed in 600 parts deionized water. The mixture was then cooled to room temperature to obtain a hydroxyacrylic acid dispersion.

[0046] The present invention also provides the following comparative examples.

[0047] Comparative Example 1

[0048] A method for preparing a hydroxyacrylic acid dispersion includes the following steps:

[0049] 30 parts of ethylene glycol butyl ether and 30 parts of solvent oil No. 100 were added to a reaction vessel, and the temperature was raised to 150-155℃. 112 parts of butyl acrylate, 84 parts of hydroxyethyl methacrylate, 108 parts of methyl methacrylate, 40 parts of styrene, 10 parts of acrylic acid, and 14 parts of di-tert-amyl peroxide were mixed evenly and added dropwise to the reaction vessel over a 4-hour period. The reaction was maintained at this temperature for 1 hour. The temperature was then lowered to 80℃, and 12 parts of N,N-dimethylethanolamine, a neutralizing agent, were added and dispersed in 520 parts of water. The mixture was cooled to room temperature to obtain a hydroxyacrylic acid dispersion.

[0050] Comparative Example 2

[0051] A method for preparing a hydroxyacrylic acid dispersion includes the following steps:

[0052] 27 parts of glycidyl tert-carbonate were added to a reaction vessel, and the temperature was raised to 150–155°C. 12.4 parts of butyl acrylate, 7 parts of hydroxyethyl methacrylate, 18 parts of methyl methacrylate, 20 parts of styrene, 13 parts of acrylic acid, and 0.7 parts of di-tert-amyl peroxide were mixed thoroughly and added dropwise over 4 hours. The mixture was kept at this temperature for 1 hour. The temperature was then lowered to 80°C, and 4 parts of N,N-dimethylethanolamine (a neutralizing agent) were added and dispersed in 115 parts of water. The mixture was cooled to room temperature to obtain a hydroxyacrylic acid dispersion.

[0053] Comparative Example 3

[0054] The difference from Example 3 is only that maleic anhydride and oleic acid are not prepared; instead, an equal amount of maleic anhydride is used to replace maleic anhydride and oleic acid in the preparation method of the hydroxyacrylic acid dispersion. The resin gels during the reaction.

[0055] Comparative Example 4

[0056] A. The preparation method of maleic anhydride oleic acid includes the following steps:

[0057] 279 parts of linoleic acid were added to the flask, the temperature was raised to 220°C, 99 parts of maleic anhydride were added, and the reaction continued until there was no reflux. After cooling, maleic anhydride oleic acid was obtained, which is an oily, low-viscosity liquid.

[0058] B. A method for preparing a solvent-free hydroxyacrylic acid dispersion, comprising the following steps:

[0059] Add 30 parts of maleic anhydride and oleic acid, and 30 parts of linolenic acid to a reaction vessel. Heat to 150–155°C. Mix 140 parts of butyl acrylate, 120 parts of hydroxyethyl methacrylate, 107 parts of methyl methacrylate, 110 parts of styrene, and 19 parts of di-tert-amyl peroxide evenly. Add this mixture dropwise to the reaction vessel over 4.5 hours and maintain the temperature for 1 hour. Cool to 80°C and add 22 parts of N,N-dimethylethanolamine as a neutralizing agent. Disperse the mixture in 600 parts of deionized water and cool to room temperature to obtain a hydroxyacrylic acid dispersion.

[0060] Comparative Example 5

[0061] The only difference from Example 1 is that the reaction temperature for synthesizing maleic anhydride oleic acid is 180°C.

[0062] Comparative Example 6

[0063] The only difference from Example 1 is that the amount of maleic anhydride added during the synthesis of maleic anhydride oleic acid is 50 parts.

[0064] Example 1

[0065] The performance of the hydroxyacrylic acid dispersions prepared in Examples 1-4 and Comparative Examples 1-6 was tested according to the following standards or methods:

[0066] I. Hydroxyl content test: The hydroxyl content is calculated using the following formula:

[0067] Hydroxyl content (%) = m * 17 / (Mw * M) * 100%

[0068] The hydroxyl content is the percentage of hydroxyl groups in the total solids by weight, %

[0069] m is the mass of the hydroxyl-containing monomer, in g.

[0070] Mw is the molecular weight of the hydroxyl-containing monomer, in g / mol.

[0071] M is the total mass of the solid, in grams.

[0072] II. Solid content test: The test shall be conducted in accordance with GB / T1725-2007.

[0073] III. Viscosity test: 25±2℃, 2# rotor 60r / min.

[0074] The products prepared in Examples 1-4 and Comparative Examples 1-6 were subjected to performance testing, and the results are shown in Table 1.

[0075] Table 1 Performance Test Results

[0076] Example 1 3.0 45 900～1500 Example 2 3.0 45 700～1400 Example 3 3.0 45 500～900 Example 4 2.6 45 900～1200 Comparative Example 1 3.0 45 500～900 Comparative Example 2 3.0 45 800～1500 Comparative Example 3 3.0 gel gel Comparative Example 4 3.0 45 Layering Comparative Example 5 3.0 45 12000～20000 Comparative Example 6 3.0 45 800～1700

[0077] Example 2

[0078] The application performance of the hydroxyacrylic acid dispersions prepared in Examples 1-4 and Comparative Examples 1-6 was tested using the following methods:

[0079] Raw material composition: 60 parts hydroxy acrylic acid dispersion, 2 parts ethylene glycol butyl ether, 2 parts dipropylene glycol butyl ether, 0.3 parts BYK346, 0.1 parts Tego 902W, 0.2 parts thickener 0620, 15 parts titanium dioxide R996, 0.8 parts dispersant Tego 760W, 5 parts zinc phosphate, 12 parts Bayhydur 2655, and 2 parts propylene glycol methyl ether acetate.

[0080] (1) Grinding the color paste

[0081] Add 7 parts water and 0.8 parts dispersant Tego 760W, stir evenly, and while stirring, add 15 parts titanium dioxide R996, 5 parts zinc phosphate, and 0.1 parts Tego 902W. Add zirconium beads and grind at high speed until the fineness is ≤25 microns, then discharge.

[0082] (2) Diluting the curing agent Bayhydur 2655

[0083] Add 2 parts of Bayhydur 265512 parts to propylene glycol methyl ether acetate and stir well.

[0084] (3) Preparation of white paint

[0085] Add 60 parts of hydroxyacrylic acid dispersion, while stirring, add 2 parts of ethylene glycol butyl ether, 2 parts of dipropylene glycol butyl ether, and 0.3 parts of BYK3460. Stir until homogeneous, then add 28 parts of color paste and stir for 5 minutes. Add 0.2 parts of thickener 06200 and stir for 5 minutes. Add 14 parts of diluted curing agent and stir until homogeneous.

[0086] The anti-rust paints formulated in Examples 1-4 and Comparative Examples 1-6 were tested according to HG / T 4847-2015. The curing conditions were baking at 80℃ for 2 hours and then at room temperature for 1 day. The initial water resistance test curing conditions were 25℃ for 1 day. The test results are shown in Table 2.

[0087] Table 2

[0088] Example 1 91 none 120 No abnormalities No abnormalities 300 Example 2 90 none 115 No abnormalities No abnormalities 320 Example 3 92 none 107 No abnormalities No abnormalities 301 Example 4 91 none 125 No abnormalities No abnormalities 312 Comparative Example 1 85 ＞10 80 foaming foaming 120 Comparative Example 2 82 ＞10 75 No abnormalities foaming 155 Comparative Example 3 ---- ---- ----- ----- ----- ----- Comparative Example 4 ---- ---- ----- ----- ----- ----- Comparative Example 5 77 none 70 No abnormalities No abnormalities 170 Comparative Example 6 74 none 70 No abnormalities No abnormalities 175

[0089] As can be seen from Table 2, the polyurethane two-component topcoat paint prepared by the solvent-free acrylic dispersion of the present invention has high gloss, does not flash rust without the addition of anti-flame rust additives, has high bubble burst limit, and has good water resistance, especially in the initial stage, and good salt spray resistance.

[0090] Finally, it should be noted that in this invention, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus.

[0091] Although this disclosure has been described above through specific embodiments, it should be understood that those skilled in the art can devise various modifications, improvements, or equivalents to this disclosure within the spirit and scope of the appended solutions. Such modifications, improvements, or equivalents should also be considered to be included within the scope of protection claimed in this disclosure.

Claims

1. A method for preparing a solvent-free hydroxyacrylic acid dispersion, characterized in that, The steps include the following: (1) Add maleic anhydride, oleic acid and oleic acid to the reaction vessel and mix. Heat to 150~155℃. Mix glycidyl methacrylate, acrylic hydroxyl monomer, other acrylic monomers and initiator evenly. Add to the reaction vessel at a uniform rate for 4~5h. Keep warm for 1h to obtain material A. (2) Cool the material A to 80°C and add a neutralizing agent to obtain material B; (3) Disperse the material B in deionized water to obtain the solvent-free hydroxy acrylic acid dispersion; The weight proportions of each component are as follows: maleic anhydride and oleic acid 20-60 parts, oleic acid 60-150 parts, glycidyl methacrylate 30-120 parts, acrylic hydroxy monomers 0-80 parts, other acrylic monomers 200-400 parts, initiator 12-25 parts, neutralizer 15-30 parts, and deionized water 500-700 parts. The method for preparing the maleic anhydride oleic acid includes: mixing maleic anhydride and linolenic acid in a molar ratio of 1:1 to 3:1, heating to 210 to 250°C, and reacting until there is no reflux to obtain the maleic anhydride oleic acid.

2. The method for preparing the solvent-free hydroxyacrylic acid dispersion according to claim 1, characterized in that, The oleic acid is an unsaturated fatty acid selected from one of soybean oil acid, linolenic acid, tung oil acid, and dehydrated ricinoleic acid; And / or, the acrylic hydroxy monomer is selected from at least one of hydroxyethyl acrylate, hydroxyethyl methacrylate, hydroxypropyl acrylate, and hydroxypropyl methacrylate; And / or, the other acrylic monomers are selected from at least two of butyl acrylate, butyl methacrylate, isobornyl methacrylate, methyl methacrylate, and acrylic acid; And / or, the initiator is selected from one or two of tert-butyl peroxide, di-tert-butyl peroxide, di-tert-pentyl peroxide, cumene hydroperoxide, and tert-butyl peroxide (2-ethylhexanoate).

3. The method for preparing the solvent-free hydroxyacrylic acid dispersion according to claim 1, characterized in that, The neutralizing agent is selected from at least one of N,N-dimethylethanolamine, triethylamine, N-ethylmorpholine, ammonia, and 2-amino-2-methyl-1-propanol.

4. A solvent-free hydroxyacrylic acid dispersion, which is prepared by the method for preparing the solvent-free hydroxyacrylic acid dispersion according to any one of claims 1 to 3.

5. The application of the solvent-free hydroxy acrylic dispersion as described in claim 4 in the field of waterborne coatings.