Water-based UV colored paint and preparation method thereof

Abstract

The invention relates to the technical field of water-based UV colored paint, and particularly discloses water-based UV colored paint and a preparation method thereof. The invention relates to a water-based UV colored paint, which comprises a polyurethane acrylic emulsion, a wetting leveling agent, a photoinitiator, a thickener, a polyethylene wax slurry, a water-based aluminum paste, diethylene glycol butyl ether, dipropylene glycol methyl ether acetate, dialkyl dithiocarbamate, a pigment and water, the polyurethane acrylic emulsion comprises 35%-45% of polyurethane, 10%-20% of acrylic acid and 40%-50% of water; the photoinitiator is formed by mixing 4-methyl benzophenone and 2, 4, 6-trimethyl benzophenone according to the mass ratio of 1: (1.8 to 2.2). The water-based UV colored paint provided by the invention has good performance in the aspects of curing, curing depth and adhesive force.

Description

Technical Field

[0001] The invention relates to the technical field of water-based UV colored paint, in particular to a water-based UV colored paint and a preparation method thereof. Background Art

[0002] As global environmental awareness grows, water-based UV paint, as a green and environmentally friendly coating technology, is gradually gaining favor in the market. This type of coating is not only non-toxic, harmless, non-flammable and non-explosive, but also meets the current high requirements for environmental protection. However, the development of water-based UV paint technology is still in the stage of continuous improvement and innovation.

[0003] At present, water-based UV paints on the market generally have the problem of not being able to cure when the color is deep, which is mainly due to the strong absorption of ultraviolet rays by dark pigments, resulting in incomplete deep curing of the coating. The characteristic of dark pigments to absorb ultraviolet rays also limits the curing depth of water-based UV paints. At present, the cured film thickness of water-based UV paints on the market can only be controlled at 6-8μm, which limits its application range. In addition, the incomplete curing of water-based UV paints directly affects the adhesion stability of the paint film, and then affects the durability and aesthetics of the paint film. At present, some water-based UV paints on the market improve the curing effect by adjusting the type and amount of photoinitiators. However, even so, after adding dark pigments, this type of water-based UV paint is still difficult to achieve the ideal curing depth. At present, the content of dark pigments in most water-based UV paints on the market only accounts for the highest 2%, which is far from meeting the market demand for dark paint films.

[0004] Therefore, it is necessary to provide a water-based UV paint that can effectively solve the problem of dark pigment curing, so as to improve the curing depth and adhesion of the paint film, expand the application range of water-based UV paint, and meet the market demand for dark paint films. Summary of the invention

[0005] In order to effectively solve the problem of dark pigment curing, the present application provides a water-based UV paint and a preparation method thereof. The present application uses a specific polyurethane acrylic emulsion, a photoinitiator, diethylene glycol butyl ether, dipropylene glycol methyl ether acetate and dialkyl dithiocarbamate to compound, and finally achieves a significant improvement in the curing, curing depth and adhesion of the water-based UV paint.

[0006] In the first aspect, the present application provides a water-based UV paint adopting the following technical solution: A water-based UV paint comprises the following raw materials in percentage by mass: 60%-70% polyurethane acrylic emulsion, 1%-2% wetting and leveling agent, 2%-3% photoinitiator, 1%-2% thickener, 2%-3% polyethylene wax paste, 5%-7% water-based aluminum silver paste, 2%-3% diethylene glycol butyl ether, 2%-3% dipropylene glycol methyl ether acetate, 1%-2% dialkyl dithiocarbamate, 0-6% pigment, and the balance is water; The polyurethane acrylic emulsion comprises, by weight percentage, 35%-45% polyurethane, 10%-20% acrylic acid and 40%-50% water; The photoinitiator is a mixture of 4-methylbenzophenone and 2,4,6-trimethylbenzophenone, and the mass ratio of the 4-methylbenzophenone to the 2,4,6-trimethylbenzophenone is 1:(1.8-2.2).

[0007] In the above technical scheme, the present application specifically defines the ratio of polyurethane acrylic emulsion and photoinitiator, and adds diethylene glycol butyl ether, dipropylene glycol methyl ether acetate and dialkyl dithiocarbamate to assist film formation and curing, thereby ensuring that in the presence of dark pigments, the photoinitiator can more effectively absorb ultraviolet rays and initiate polymerization reactions, thereby improving the curing depth of the paint film, so that the paint film has a wider curing depth and better adhesion.

[0008] Preferably, the mass ratio of 4-methylbenzophenone to 2,4,6-trimethylbenzophenone is 1:2.

[0009] In the above technical scheme, the present application further optimizes the ratio of the photoinitiator by specifically limiting the mass ratio of 4-methylbenzophenone and 2,4,6-trimethylbenzophenone to 1:2, further promotes the coordination effect of the photoinitiator and other components in the water-based UV paint, so that the photoinitiator can more efficiently initiate the polymerization reaction after absorbing ultraviolet rays, thereby improving the curing speed and curing depth of the paint film.

[0010] Preferably, the mass ratio of diethylene glycol butyl ether, dipropylene glycol methyl ether acetate and dialkyl dithiocarbamate is 2.5:2.2:1.5.

[0011] In the above technical scheme, the present application further optimizes the ratio of auxiliary film-forming curing agents by further limiting the mass ratio of diethylene glycol butyl ether, dipropylene glycol methyl ether acetate and dialkyl dithiocarbamate to 2.5:2.2:1.5, thereby ensuring that in the presence of dark pigments, these auxiliary film-forming curing agents can more effectively synergize with the photoinitiator, thereby improving the curing uniformity and adhesion of the paint film.

[0012] Preferably, the polyurethane acrylic emulsion comprises 40% polyurethane, 15% acrylic acid and 45% water in terms of mass percentage of the polyurethane acrylic emulsion.

[0013] In the above technical solution, the present application ensures that the paint film has good curing effect and adhesion by further limiting the content of each component in the polyurethane acrylic emulsion.

[0014] Preferably, the wetting and leveling agent is polyether-modified silicone.

[0015] In the above technical scheme, this application reduces the surface tension of water-based UV paint by limiting the wetting and leveling agent to polyether-modified silicone, further improves the leveling and glossiness of the paint film, makes the paint film surface smoother and more uniform, and improves the overall aesthetics of the paint film.

[0016] Preferably, the thickener is a nonionic polyurethane associative thickener.

[0017] In the above technical solution, the present application further enhances the stability and anti-sagging property of the paint film by limiting the thickener to a non-ionic polyurethane associative thickener, so that the paint film is less likely to sag during the construction process, thereby improving the construction quality.

[0018] In the second aspect, the present application provides a method for preparing a water-based UV paint using the following technical solution: A method for preparing a water-based UV paint comprises the following steps: Step 1: Take polyurethane acrylic emulsion, add wetting and leveling agent while stirring, stir evenly to obtain base material; take diethylene glycol butyl ether, dipropylene glycol methyl ether acetate, dialkyl dithiocarbamate and photoinitiator, stir until completely melted, and obtain preparation 1; mix water-based aluminum silver paste, pigment and water, stir evenly, and obtain preparation 2; Step 2: Add ingredient 1 to the base material and stir evenly; Step 3: Add polyethylene wax slurry and stir evenly; Step 4: Add ingredient 2 and mix well; Step 5: Add thickener and stir evenly to obtain water-based UV paint.

[0019] In the above technical scheme, the present application provides a method for preparing a water-based UV paint, which is simple, efficient and suitable for industrial production.

[0020] Preferably, the stirring speed of step 1, step 2, step 3, step 4 and step 5 is 400-500 rpm.

[0021] In the above technical solution, the present application limits the stirring speed to 400-500rpm, thereby ensuring that the components can be fully mixed during the preparation process, while avoiding emulsion destruction caused by excessive shear force, thereby ensuring the stability and uniformity of the water-based UV paint.

[0022] In a third aspect, the present application provides a method for using a water-based UV paint using the following technical solution: A method for using a water-based UV paint comprises: using a brush, roller coating or spraying to evenly apply the water-based UV paint on a surface to be coated, using an ultraviolet light source to perform radiation curing on the applied water-based UV paint, and obtaining a UV paint layer after drying.

[0023] In the above technical solution, the present application obtains the paint film by UV curing, thus meeting the market demand for dark paint films.

[0024] In summary, this application includes the following beneficial technical effects: 1. The present application improves the curing depth of the paint film by adopting a compound of a specific polyurethane acrylic emulsion, a photoinitiator, diethylene glycol butyl ether, dipropylene glycol methyl ether acetate and dialkyl dithiocarbamate, so that the paint film has a wider curing depth and better adhesion.

[0025] 2. The dark pigment addition amount of the water-based UV paint of the present application can reach 6%, which is significantly higher than the water-based UV paint on the market. DETAILED DESCRIPTION

[0026] In order to better illustrate the purpose, technical solutions and advantages of the present invention, the present invention will be further described below in conjunction with specific embodiments.

[0027] Example 1 A water-based UV paint comprises: polyurethane acrylic emulsion, a wetting and leveling agent, a photoinitiator, a thickener, polyethylene wax slurry, water-based aluminum silver slurry, diethylene glycol butyl ether, dipropylene glycol methyl ether acetate, dialkyl dithiocarbamate, pigment and water.

[0028] The polyurethane acrylic emulsion contains 40% polyurethane, 15% acrylic acid and 45% water.

[0029] The photoinitiator is a mixture of 4-methylbenzophenone and 2,4,6-trimethylbenzophenone in a mass ratio of 1:2.

[0030] Among them, the wetting and leveling agent is polyether modified silicone, specifically BYK-370 from Germany.

[0031] The thickener is a nonionic polyurethane associative thickener, specifically Hemmings RHEOLATE 299.

[0032] The polyethylene wax slurry is specifically BYK-513 polyethylene wax emulsion.

[0033] The water-based aluminum paste is specifically Eckart aluminum pigment PC 100.

[0034] Among them, the CAS number of diethylene glycol butyl ether is: 112-34-5.

[0035] Among them, the CAS number of dipropylene glycol methyl ether acetate is: 88917-22-0.

[0036] Among them, the CAS number of dialkyl dithiocarbamate is: 10254-57-6.

[0037] The pigment is a black pigment, specifically Columbia, brand Raven 5000.

[0038] The preparation method of water-based UV paint comprises the following steps: Step 1: a: Take polyurethane acrylic emulsion, add wetting and leveling agent while stirring at 450 rpm, and continue stirring for 4 minutes after adding to obtain the base material.

[0039] b: Take diethylene glycol butyl ether, dipropylene glycol methyl ether acetate, dialkyl dithiocarbamate and photoinitiator, mix, and stir at 450 rpm for 18 minutes to obtain preparation 1.

[0040] c: Mix the aqueous aluminum paste, pigment and water, and stir at 450 rpm for 4 minutes to obtain material 2.

[0041] Step 2: Add material 1 to the base material and stir at 450 rpm for 4 minutes.

[0042] Step 3: Add polyethylene wax slurry and stir at 450 rpm for 4 minutes.

[0043] Step 4: Add material 2 and stir at 450 rpm for 6 minutes.

[0044] Step 5: Add thickener and stir at 450 rpm for 12 minutes to obtain water-based UV paint.

[0045] Example 2 A water-based UV paint, which is different from Example 1 in that it comprises: polyurethane acrylic emulsion, a wetting and leveling agent, a photoinitiator, a thickener, polyethylene wax slurry, water-based aluminum silver slurry, diethylene glycol butyl ether, dipropylene glycol methyl ether acetate, dialkyl dithiocarbamate, pigment, and water.

[0046] The polyurethane acrylic emulsion contains 35% polyurethane, 20% acrylic acid and 45% water.

[0047] The photoinitiator is a mixture of 4-methylbenzophenone and 2,4,6-trimethylbenzophenone in a mass ratio of 1:1.8.

[0048] The preparation method of water-based UV paint comprises the following steps: Step 1: a: Take polyurethane acrylic emulsion, add wetting and leveling agent while stirring at 400 rpm, and continue stirring for 5 minutes after adding to obtain the base material.

[0049] b: Take diethylene glycol butyl ether, dipropylene glycol methyl ether acetate, dialkyl dithiocarbamate and photoinitiator, mix, and stir at 400 rpm for 20 minutes to obtain preparation 1.

[0050] c: Mix the aqueous aluminum paste, pigment and water, and stir at 400 rpm for 5 minutes to obtain material 2.

[0051] Step 2: Add material 1 to the base material and stir at 400 rpm for 5 minutes.

[0052] Step 3: Add polyethylene wax slurry and stir at 400 rpm for 5 minutes.

[0053] Step 4: Add material 2 and stir at 400 rpm for 8 minutes.

[0054] Step 5: Add thickener and stir at 400 rpm for 15 minutes to obtain water-based UV paint.

[0055] Example 3 A water-based UV paint, which is different from Example 1 in that it comprises: polyurethane acrylic emulsion, a wetting and leveling agent, a photoinitiator, a thickener, polyethylene wax slurry, water-based aluminum silver slurry, diethylene glycol butyl ether, dipropylene glycol methyl ether acetate, dialkyl dithiocarbamate, pigment, and water.

[0056] The polyurethane acrylic emulsion contains 45% polyurethane, 10% acrylic acid and 45% water.

[0057] The photoinitiator is a mixture of 4-methylbenzophenone and 2,4,6-trimethylbenzophenone in a mass ratio of 1:2.2.

[0058] The preparation method of water-based UV paint comprises the following steps: Step 1: a: Take polyurethane acrylic emulsion, add wetting and leveling agent while stirring at 500 rpm, and continue stirring for 3 minutes after adding to obtain the base material.

[0059] b: Take diethylene glycol butyl ether, dipropylene glycol methyl ether acetate, dialkyl dithiocarbamate and photoinitiator, mix, and stir at 500 rpm for 15 minutes to obtain preparation 1.

[0060] c: Mix the aqueous aluminum paste, pigment and water, and stir at 500 rpm for 3 minutes to obtain material 2.

[0061] Step 2: Add material 1 to the base material and stir at 500 rpm for 3 minutes.

[0062] Step 3: Add polyethylene wax slurry and stir at 500 rpm for 3 minutes.

[0063] Step 4: Add material 2 and stir at 500 rpm for 5 minutes.

[0064] Step 5: Add thickener and stir at 500 rpm for 10 min to obtain water-based UV paint.

[0065] The amounts of raw materials used in Examples 1-3 are shown in Table 1.

[0066] Table 1: Embodiment 4-7 A water-based UV paint, which is different from Example 1 in that the amount of pigment used is different.

[0067] The amounts of raw materials used in Examples 4-7 are shown in Table 2.

[0068] Comparative Example 1 A water-based UV paint, which is different from Example 1 in that the polyurethane acrylic emulsion is Japanese Mitsui Chemicals RA7004 water-based polyurethane emulsion.

[0069] Comparative Example 2 A water-based UV paint, which is different from Example 1 in that the photoinitiator is 4-methylbenzophenone.

[0070] Comparative Example 3 A water-based UV paint, which is different from Example 1 in that the photoinitiator is 2,4,6-trimethylbenzophenone.

[0071] Comparative Example 4 A water-based UV paint, which is different from Example 1 in that the photoinitiator is a mixture of 4-methylbenzophenone and 2,4,6-trimethylbenzophenone in a mass ratio of 1:1.5.

[0072] Comparative Example 5 A water-based UV paint, which is different from Example 1 in that the photoinitiator is a mixture of 4-methylbenzophenone and 2,4,6-trimethylbenzophenone in a mass ratio of 1:2.5.

[0073] Comparative Example 6 A water-based UV paint, which is different from Example 1 in that diethylene glycol butyl ether is replaced by dipropylene glycol methyl ether in an equal amount.

[0074] Comparative Example 7 A water-based UV paint, which is different from Example 1 in that dipropylene glycol methyl ether acetate is replaced by propylene glycol methyl ether acetate in an equal amount.

[0075] Comparative Example 8 A water-based UV paint, which is different from Example 1 in that an equal amount of dialkyl dithiocarbamate is replaced by isopentyl p-dimethylaminobenzoate.

[0076] Comparison Example A commercially available black water-based UV paint.

[0077] Curing depth detection: The color paint of the above-mentioned embodiments and comparative examples was applied to the surface of the ABS substrate, and the test was started from the curing depth of 4 μm. The test gradient was 1 μm, and the curing depth of the previous gradient when the hardness of the paint film measured by a hardness meter dropped significantly was recorded as the curing depth.

[0078] Curing time detection: the paint film thickness is 4μm, the ultraviolet light intensity is 600mj / cm2, and the paint film curing time is recorded.

[0079] Adhesion test: The film thickness is 4μm, and the 100-grid test is used, and the 3M tape is used to pull it continuously for more than 3 times. The evaluation levels are as follows: 5B: The edges of the lines are smooth, and there is no paint peeling at the edges and intersections of the lines.

[0080] 4B: Small pieces of paint have fallen off at the intersections of the lines, and the total area of ​​the paint has fallen off is less than 5%.

[0081] 3B: Small flakes of paint are falling off at the edges and intersections of the lines, and the total area of ​​paint falling off is between 5% and 15%.

[0082] 2B: There are pieces of paint falling off at the edges and intersections of the lines, and the total area of ​​the paint falling off is between 15% and 35%.

[0083] 1B: There are flakes of paint falling off at the edges and intersections of the lines, and the total area of ​​paint falling off is between 35% and 65%.

[0084] 0B: The shedding area exceeds the 1B standard.

[0085] Alcohol resistance test: Use a cotton swab dipped in anhydrous alcohol to wipe 500 times with a load of 2.5kg / force, and observe whether there is any color change.

[0086] The above test results are shown in Table 3.

[0087] Table 3: It can be seen from the above test results that the water-based UV paints of Examples 1 to 7 all show good performance in terms of curing depth range, curing time, adhesion and alcohol resistance. It can be seen that when the black pigment addition amount of the water-based UV paint of the present application is between 2% and 6%, the curing depth of the water-based UV paint of the present application can reach 12-16 μm.

[0088] Specifically combining the analysis of Example 1 and Comparative Examples 1-8, it is not difficult to see that the water-based UV paint of Example 1 shows good performance in terms of curing depth range, curing time, adhesion and alcohol resistance. It can be seen that only by using a specific polyurethane acrylic emulsion, photoinitiator, diethylene glycol butyl ether, dipropylene glycol methyl ether acetate and dialkyl dithiocarbamate compound can the curing, curing depth and adhesion of the water-based UV paint be significantly improved.

[0089] 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 water-based UV paint, characterized in that: The invention comprises the following raw materials in percentage by weight: 60%-70% polyurethane acrylic emulsion, 1%-2% wetting and leveling agent, 2%-3% photoinitiator, 1%-2% thickener, 2%-3% polyethylene wax paste, 5%-7% water-based aluminum silver paste, 2%-3% diethylene glycol butyl ether, 2%-3% dipropylene glycol methyl ether acetate, 1%-2% dialkyl dithiocarbamate, 0-6% pigment, and the balance is water; The polyurethane acrylic emulsion comprises, by weight percentage, 35%-45% polyurethane, 10%-20% acrylic acid and 40%-50% water; The photoinitiator is a mixture of 4-methylbenzophenone and 2,4,6-trimethylbenzophenone, and the mass ratio of the 4-methylbenzophenone to the 2,4,6-trimethylbenzophenone is 1:(1.8-2.2).

2. A water-based UV paint according to claim 1, characterized in that: The mass ratio of the 4-methylbenzophenone to the 2,4,6-trimethylbenzophenone is 1:

2.

3. A water-based UV paint according to claim 1, characterized in that: The mass ratio of diethylene glycol butyl ether, dipropylene glycol methyl ether acetate and dialkyl dithiocarbamate is 2.5:2.2:1.

5.

4. A water-based UV paint according to claim 1, characterized in that: In terms of mass percentage of the polyurethane acrylic emulsion, the polyurethane acrylic emulsion comprises 40% polyurethane, 15% acrylic acid and 45% water.

5. A water-based UV paint according to claim 1, characterized in that: The wetting and leveling agent is polyether-modified silicone.

6. A water-based UV paint according to claim 1, characterized in that: The thickener is a nonionic polyurethane associative thickener.

7. A method for preparing a water-based UV paint according to any one of claims 1 to 6, characterized in that: The following steps are involved: Step 1: Take polyurethane acrylic emulsion, add wetting and leveling agent while stirring, stir evenly to obtain base material; take diethylene glycol butyl ether, dipropylene glycol methyl ether acetate, dialkyl dithiocarbamate and photoinitiator, stir until completely melted, and obtain preparation 1; mix water-based aluminum silver paste, pigment and water, stir evenly, and obtain preparation 2; Step 2: Add ingredient 1 to the base material and stir evenly; Step 3: Add polyethylene wax slurry and stir evenly; Step 4: Add ingredient 2 and mix well; Step 5: Add thickener and stir evenly to obtain water-based UV paint.

8. The method for preparing a water-based UV paint according to claim 7, characterized in that: The stirring speed of step 1, step 2, step 3, step 4 and step 5 is 400-500 rpm.

Images