Water-based high-hanging paint protective coating and preparation method thereof

Abstract

The invention relates to the technical field of water-based high-hanging-paint protective coatings, in particular to a water-based high-hanging-paint protective coating and a preparation method thereof, and the water-based high-hanging-paint protective coating comprises the following components in parts by weight: 35-40 parts of nano organic polysaccharide fiber modified water-based acrylic resin; 20 to 25 parts of rutile type titanium dioxide; 15 to 20 parts of water-based amino resin; 1-2 parts of a water-based adhesion promoter; 0.5 to 0.8 part of a water-based pH regulator; 2-10 parts of a water-based cosolvent; 0.2 to 0.3 part of a water-based wetting leveling agent; 15 to 20 parts of deionized water; mixing and stirring nano organic polysaccharide fiber modified water-based acrylic resin, rutile titanium dioxide, water-based methylated amino resin and a water-based pH regulator; and adding the water-based adhesion promoter, the water-based cosolvent, the water-based wetting leveling agent and the deionized water, and stirring and mixing to obtain the water-based coating. After the anti-sagging coating is sprayed on a workpiece, along with association of hydrogen bonds in a system, the viscosity of the coating quickly rises to achieve a good anti-sagging effect, so that the coating has a better sagging amount at an acute angle, and good protection capability is realized.

Description

Technical Field

[0001] The invention relates to the technical field of water-based high-hang paint protective coatings, in particular to a water-based high-hang paint protective coating and a preparation method thereof. Background Art

[0002] At present, the National Environmental Protection Agency has extremely strict requirements on the construction of paint spraying companies and strictly controls VOC emissions. Many industries also have a trend of switching from solvent-based baking paint to water-based baking paint.

[0003] As for the coating currently used on bicycles, the overall tendency is to use DISK electrostatic spraying. Due to the special forging characteristics of bicycle frames, welding is generally used to fix the joints. Obvious textures and unevenness will appear during welding. During the spraying process, due to the relatively serious acute angle effect at the sharp welding points, the acute angles after paint coating are prone to problems such as exposed bottom and rust due to the flow of the paint film, which leads to insufficient paint application. This brings great trouble to the painting of bicycles. At present, the market mostly adopts the method of manual front and back correction to pre-coat and repair leak-prone areas. It causes a waste of human resources, limits the design of fully automated coating, and the manual pre-coating effect cannot achieve the expected effect in terms of performance. The present invention aims to increase the coating rate of the paint film at acute angles and solve the problems of missing coating and thin coating at one time. Summary of the Invention

[0004] The technical problem to be solved by the present invention is to provide a water-based high-hanging paint protective coating to solve the above problems.

[0005] In order to solve the above technical problems, the technical solution adopted by the present invention is: a water-based high-hang paint protective coating, comprising the following components in parts by weight:

[0006]

[0007]

[0008] The structure of the nano-organic polysaccharide fiber modified water-based acrylic resin is as follows:

[0009]

[0010] The nano-organic polysaccharide fiber-modified water-based acrylic resin has a solid content of 40%, a pH value of 7.5-8.5, a hydroxyl value of 2.0, and a nano-organic polysaccharide fiber content of 3%.

[0011] As a further embodiment of the present invention, the preparation method of the nano-organic polysaccharide fiber modified water-based acrylic resin comprises the following steps:

[0012] S1, using methacrylic acid, styrene, methyl methacrylate, butyl methacrylate, hydroxyethyl methacrylate, and ethylene glycol butyl ether as raw materials, adding an appropriate amount of dibenzoyl peroxide and reacting at 140°C for 4 hours to obtain an acrylic resin with a solid content of 40%;

[0013] S2, placing the preliminarily crushed plant fiber in a weak alkaline aqueous solution with a pH of 7.0-8.0, washing for 4 hours, and drying at 50°C for 8 hours to remove moisture; placing the dried plant fiber in a hammer crusher and crushing it into short fiber particles of 1-2 mm; the short fiber particles are again ultrasonically cleaned in a weak alkaline aqueous solution with a pH of 8.0-8.5 for 4 hours to remove impurities, hemicellulose and pectin substances, and then rinsed with pure water to maintain a concentration of 10%; continuously processing the material using a high-pressure homogenization method until the particle size is refined to 100-200 nanometers, and then filtering and separating to obtain an organic nanopolysaccharide fiber suspension;

[0014] S3, dropping the nano polysaccharide fiber suspension prepared in S2 into the polyurethane prepolymer obtained in step S1, reacting at 80°C for 4 hours, adjusting the pH value to 8.0, adding water for phase conversion, and obtaining a nano organic polysaccharide fiber modified waterborne acrylic resin.

[0015] As a further embodiment of the present invention, the water-based amino resin is a water-based methylated amino resin.

[0016] As a further embodiment of the present invention, the aqueous adhesion promoter is polyester phosphate; and the aqueous pH adjuster is dimethylethanolamine.

[0017] As a further solution of the present invention, the aqueous cosolvent is propylene glycol methyl ether; and the aqueous wetting and leveling agent is polyether-modified silicone.

[0018] A method for preparing a water-based high-hang paint protective coating, the specific steps are as follows:

[0019] Step 1: Mix and stir nano-organic polysaccharide fiber-modified water-based acrylic resin, rutile titanium dioxide, water-based amino resin, and water-based pH regulator to prepare a premixed solution;

[0020] Step 2: Add water-based adhesion promoter, water-based cosolvent, water-based wetting and leveling agent, and deionized water to the premixed liquid, stir and mix, and prepare a water-based high-hang paint protective coating.

[0021] As a further solution of the present invention, the mixing stirring speed in step 1 is 800-1000 r / min, and the stirring time is 10-20 min.

[0022] As a further solution of the present invention, the mixing speed in step 2 is 800-1000 r / min and the stirring time is 10-20 min.

[0023] Since the present invention adopts the above technical solution, the advantages and positive effects of the present invention are:

[0024] 1. After special modification, the nano-organic polysaccharide fiber modified water-based acrylic resin has a very special flow curve. It is in a high viscosity state when stationary. When sprayed, due to the atomization of high-pressure air, the viscosity of the coating drops sharply and reaches a very good atomization state; at the same time, due to the very good particle size of the atomized particles, it has very excellent instantaneous leveling ability.

[0025] 2. After spraying on the workpiece, with the association of hydrogen bonds in the system, the viscosity of the paint quickly recovers to achieve a good anti-sagging effect, so that a better amount of paint can be hung at sharp corners to achieve good protective capabilities.

[0026] 3. Add appropriate water-based amino resin to form a good synergistic effect with the nano-polysaccharide fiber modified water-based acrylic resin. The selected water-based amino resin has higher reactivity.

[0027] 4. The addition of water-based adhesion promoter significantly improves the drying performance, water resistance, salt spray resistance and solvent resistance of the coating. The nano-polysaccharide fiber modified water-based acrylic resin used in this product contains a large amount of easy-to-associate, which can quickly form a frame structure to achieve a good paint hanging effect. DETAILED DESCRIPTION

[0028] Example 1

[0029] Stir 35 parts of nano-polysaccharide fiber-modified water-based acrylic resin, 15 parts of water-based amino resin, and 0.5 parts of water-based pH regulator at a speed of 800 r / min for 20 minutes; then add 1 part of water-based adhesion promoter, 5 parts of water-based cosolvent, 0.2 parts of water-based wetting and leveling agent, and 20 parts of deionized water at a speed of 1000 r / min and stir and disperse for 20 minutes.

[0030] Example 2

[0031] Stir 35 parts of nano-polysaccharide fiber-modified water-based acrylic resin, 17 parts of water-based amino resin, and 0.5 parts of water-based pH regulator at a speed of 800 r / min for 20 minutes; then add 1 part of water-based adhesion promoter, 5 parts of water-based cosolvent, 0.2 parts of water-based wetting and leveling agent, and 20 parts of deionized water at a speed of 1000 r / min and stir and disperse for 20 minutes.

[0032] Example 3

[0033] Stir 35 parts of nano-polysaccharide fiber-modified water-based acrylic resin, 20 parts of water-based amino resin, and 0.3 parts of water-based pH regulator at a speed of 800 r / min for 20 minutes; then add 2 parts of water-based adhesion promoter, 5 parts of water-based cosolvent, 0.3 parts of water-based wetting and leveling agent, and 20 parts of deionized water at a speed of 800 r / min and stir and disperse for 20 minutes.

[0034] Example 4

[0035] Stir 38 parts of nano-polysaccharide fiber-modified water-based acrylic resin, 15 parts of water-based amino resin, and 0.5 parts of water-based pH regulator at a speed of 800 r / min for 20 minutes; then add 1 part of water-based adhesion promoter, 5 parts of water-based cosolvent, 0.2 parts of water-based wetting and leveling agent, and 20 parts of deionized water at a speed of 800 r / min and stir and disperse for 20 minutes.

[0036] Example 5

[0037] Stir 38 parts of nano-polysaccharide fiber-modified water-based acrylic resin, 17 parts of water-based amino resin, and 0.5 parts of water-based pH regulator at a speed of 800 r / min for 20 minutes; then add 1 part of water-based adhesion promoter, 8 parts of water-based cosolvent, 0.2 parts of water-based wetting and leveling agent, and 20 parts of deionized water at a speed of 800 r / min and stir and disperse for 20 minutes.

[0038] Example 6

[0039] Stir 35 parts of nano-polysaccharide fiber-modified water-based acrylic resin, 15 parts of water-based amino resin, and 0.5 parts of water-based pH regulator at a speed of 800 r / min for 20 minutes; then add 2 parts of water-based adhesion promoter, 5 parts of water-based cosolvent, 0.3 parts of water-based wetting and leveling agent, and 20 parts of deionized water at a speed of 800 r / min and stir and disperse for 20 minutes.

[0040] Comparative Example 1

[0041] Stir 35 parts of nano-polysaccharide fiber-modified water-based acrylic resin, 0 parts of water-based amino resin, and 0.5 parts of water-based pH regulator at a speed of 800 r / min for 20 minutes; then add 0.5 parts of water-based adhesion promoter, 1 part of water-based cosolvent, 0.1 parts of water-based wetting and leveling agent, and 20 parts of deionized water at a speed of 800 r / min, and stir and disperse for 20 minutes.

[0042] Comparative Example 2

[0043] Stir 45 parts of nano-polysaccharide fiber-modified water-based acrylic resin, 15 parts of water-based amino resin, and 1 part of water-based pH regulator at a speed of 800 r / min for 20 minutes; then add 3 parts of water-based adhesion promoter, 15 parts of water-based cosolvent, 1.0 part of water-based wetting and leveling agent, and 20 parts of deionized water at a speed of 800 r / min and stir and disperse for 20 minutes.

[0044] Comparative Example 3

[0045] Stir 25 parts of nano-polysaccharide fiber-modified water-based acrylic resin, 17 parts of water-based amino resin, and 0.5 parts of water-based pH regulator at a speed of 800 r / min for 20 minutes; then add 2 parts of water-based adhesion promoter, 8 parts of water-based cosolvent, 0.2 parts of water-based wetting and leveling agent, and 20 parts of deionized water at a speed of 800 r / min and stir and disperse for 20 minutes.

[0046] All samples were prepared and tested: aluminum plates measuring 10 cm x 5 cm (0.2 mm thick) were degreased, polished, and welded with 60° protrusions. The aqueous baking materials prepared in the above examples and comparative examples were sprayed on and baked at 140°C for 30 minutes to form paint films. Performance tests were then conducted, and the results are summarized in Table 1.

[0047] Table 1 Performance data of the aqueous baking materials prepared in each embodiment and comparative example

[0048]

[0049] As shown in Table 1, too much or too little content of nano-polysaccharide fiber modified water-based acrylic resin will have a great impact on the appearance, hardness, salt spray resistance, adhesion, and paint hanging rate of the coating film; too little content of water-based amino resin will lead to a decrease in the hardness of the paint film and poor salt spray resistance, while too much content of water-based amino resin will lead to excessive hardness of the paint film, a significant decrease in flexibility, and a decrease in salt spray resistance; too little content of pH regulator will lead to poor compatibility of the paint and a decrease in storage performance, while too much content of pH regulator will It causes the viscosity of the paint to increase, affecting the later construction; if the content of water-based adhesion promoter is too high, it will affect the hardness and salt spray resistance of the paint film; if the content of water-based co-solvent is too high, the VOC of the paint will be too high and the paint hanging rate will decrease; if the content of water-based co-solvent is too low, it will have a great impact on the leveling and wettability of the paint film, and the appearance will deteriorate; if the content of water-based wetting and leveling agent is too high, the recoating adhesion of the paint film will be poor; if the content of water-based wetting and leveling agent is too low, the wettability of the paint will deteriorate and shrinkage problems will occur.

[0050] Although specific embodiments of the present invention are described above, those skilled in the art should understand that these are merely examples and that various changes or modifications may be made to the embodiments without departing from the principles and essence of the present invention. The scope of protection of the present invention is limited only by the appended claims.

Claims

1. A water-based high-hang paint protective coating, characterized by: Including the following Components by weight: The structure of the nano-organic polysaccharide fiber modified water-based acrylic resin is as follows: The nano-organic polysaccharide fiber-modified water-based acrylic resin has a solid content of 40%, a pH value of 7.5-8.5, a hydroxyl value of 2.0, and a nano-organic polysaccharide fiber content of 3%.

2. The water-based high-hang paint protective coating according to claim 1, characterized in that: The preparation method of the nano organic polysaccharide fiber modified water-based acrylic resin comprises the following steps: S1, using methacrylic acid, styrene, methyl methacrylate, butyl methacrylate, hydroxyethyl methacrylate, and ethylene glycol butyl ether as raw materials, adding an appropriate amount of dibenzoyl peroxide and reacting at 140°C for 4 hours to obtain an acrylic resin with a solid content of 40%; S2, placing the preliminarily crushed plant fiber in a weak alkaline aqueous solution with a pH of 7.0-8.0, washing for 4 hours, and drying at 50°C for 8 hours to remove moisture; placing the dried plant fiber in a hammer crusher and crushing it into short fiber particles of 1-2 mm; the short fiber particles are again ultrasonically cleaned in a weak alkaline aqueous solution with a pH of 8.0-8.5 for 4 hours to remove impurities, hemicellulose and pectin substances, and then rinsed with pure water to maintain a concentration of 10%; continuously processing the material using a high-pressure homogenization method until the particle size is refined to 100-200 nanometers, and then filtering and separating to obtain an organic nanopolysaccharide fiber suspension; S3, dropping the nano polysaccharide fiber suspension prepared in S2 into the polyurethane prepolymer obtained in step S1, reacting at 80°C for 4 hours, adjusting the pH value to 8.0, adding water for phase conversion, and obtaining a nano organic polysaccharide fiber modified waterborne acrylic resin.

3. The water-based high-hang paint protective coating according to claim 1, characterized in that: The water-based amino resin is a water-based methyl etherified amino resin.

4. The water-based high-hang paint protective coating according to claim 1, characterized in that: The aqueous adhesion promoter is polyester phosphate; the aqueous pH regulator is dimethylethanolamine.

5. The water-based high-hang paint protective coating according to claim 1, characterized in that: The aqueous cosolvent is propylene glycol methyl ether; and the aqueous wetting and leveling agent is polyether-modified silicone.

6. The method for preparing a water-based high-hang paint protective coating according to any one of claims 1 to 5, characterized in that: Specific steps as follows: Step 1: Mix and stir nano-organic polysaccharide fiber-modified water-based acrylic resin, rutile titanium dioxide, water-based amino resin, and water-based pH regulator to prepare a premixed solution; Step 2: Add water-based adhesion promoter, water-based cosolvent, water-based wetting and leveling agent, and deionized water to the premixed liquid, stir and mix, and prepare a water-based high-hang paint protective coating.

7. The method for preparing a water-based high-hang paint protective coating according to claim 6, characterized in that: The mixing and stirring speed in the step 1 is 800-1000 r / min, and the stirring time is 10-20 min.

8. The method for preparing a water-based high-hang paint protective coating according to claim 6, characterized in that: The mixing and stirring speed in the step 2 is 800-1000 r / min, and the stirring time is 10-20 min.

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