WATER-BASED UV COATINGS, PREPARATION METHOD THEREFOR AND APPLICATION THEREOF

Abstract

The present invention provides a water-based UV coating, and a preparation method therefor and an application thereof. The coating comprises the following raw material components in parts by weight: 15-25 parts of a water-based polycarbonate dispersion, 30-60 parts of a water-based aliphatic polyurethane acrylate dispersion, 5-15 parts of a UV reactive diluent, 1-4 parts of a photoinitiator, 0.2-1 part of an auxiliary agent, 3-8 parts of a film coalescing aid, and 5-15 parts of water. The water-based UV coating of the present invention has good wear resistance after curing, is not easy to crack, and has a good application effect on an automotive interior trim part.

Claims

1. A water-based UV coatings, characterized in that, the water-based UV coating comprises the following raw material components, in parts by weight: water-based polycarbonate dispersion 15-25; water-based aliphatic polyurethane acrylate dispersion 30-60; UV reactive diluent 5-15; photoinitiator 1-4; auxiliary agent 0.2-1; film coalescing aid 3-8; and water 5-15.

2. The water-based UV coatings according to claim 1, characterized in that the functionality of the waterborne polycarbonate dispersion is 2 and a number-average molecular weight of the waterborne polycarbonate dispersion is ranging from 1000 to 5000; the functionality of the water-based aliphatic polyurethane acrylate dispersion is 6, and a number average molecular weight of the water-based aliphatic polyurethane acrylate dispersion is ranging from 800 to 3000.

3. The water-based UV coatings according to claim 1, characterized in that the molar ratio of the water-based aliphatic polyurethane acrylate dispersion to the water-based polycarbonate dispersion is 4:1 to 2:1.

4. The water-based UV coatings according to claim 1, characterized in that the UV reactive diluent is selected from one or more of ethoxylated trimethylolpropane triacrylate, propoxylated glycerol triacrylate, ethoxylated pentaerythritol tetraacrylate, and dipentaerythritol hexaacrylate.

5. The water-based UV coatings according to claim 1, characterized in that the photoinitiator comprises a surface curing photoinitiator and a deep curing photoinitiator, with a molar ratio of the former one to the latter one in the range from 2:1 to 4:1; the surface curing photoinitiator is selected from one or more of 1-hydroxycyclohexyl phenyl ketone, benzophenone, 1,1-(methylene-di-4,1-phenylene)bis[2-hydroxy-2-methyl-1-propanone], 2-hydroxy-2-methyl-1-phenyl-1-propanone, and 2-hydroxy-2-methyl-1-[4-(2-hydroxyethoxy)phenyl]-1-propanone; the deep curing photoinitiator is selected from one or more of 2,4,6-trimethylbenzoyl diphenyl phosphine oxide and bis(2,4,6-trimethyl benzoyl)phenyl phosphine oxide.

6. The water-based UV coatings according to claim 1, characterized in that, the raw material components of the water-based UV coatings further comprise, in parts by weight: water-based nano black pigment dispersion: 1-4 parts water-based hydroxyl acrylic emulsion: 10-20 parts.

7. The water-based UV coatings according to claim 6, wherein the water-based nano black pigment dispersion has a particle size ranging from 50 to 300 nm.

8. The water-based UV coatings according to claim 6, wherein a thermal curing agent is added to the water-based UV coatings, and the weight ratio of the water-based UV coatings to the thermal curing agent is ranging from 100:10 to 100:20.

9. The water-based UV coatings according to claim 6, wherein the solid hydroxyl value of the water-based hydroxyl acrylic emulsion is ranging from 60 to 110 mg KOH/g.

10. An application of the water-based UV coatings according to claim 1 in automotive interior parts, wherein the water-based UV coating is sprayed onto the automotive interior parts and subsequently cured.

11. The application of the water-based UV coatings in automotive interior parts according to claim 10, wherein the curing process comprises the following steps in sequence: baking at temperature of 50-65 C. to form a film; proceeding UV curing; and proceeding thermal curing at temperature of 70-80 C.

12. A method for preparing a water-based UV coatings, comprising the following steps: mixing a water-based polycarbonate dispersion, a water-based aliphatic polyurethane acrylate dispersion, a UV reactive diluent, a photoinitiator, an auxiliary agent, a film coalescing aid, and water thoroughly, to obtain the water-based UV coatings.

13. The method for preparing a water-based UV coatings according to claim 12, characterized in that, the raw materials components of the water-based UV coatings further comprise a water-based hydroxyl acrylic emulsion.

14. The method for preparing a water-based UV coatings according to claim 13, characterized in that, the water-based UV coatings is mixed with a thermal curing agent thoroughly, before spraying.

Description

EMBODIMENTS

[0048] The following is a further description of the technical solution of the present invention, in conjunction with specific embodiments. However, it should be noted that the present invention is not limited to these embodiments.

Examples 16

[0049] Proceeding preparation according to the coating formulation provided in Table 1, the preparation process of coatings is proceeded as follows:

[0050] (1) Mix the UV reactive diluent, film coalescing aid and photoinitiator together. Disperse the mixture with 1000 rpm for 20 minutes until it is homogeneous. While maintaining the dispersing conditions, sequentially add the water-based polycarbonate dispersion, water-based aliphatic polyurethane acrylate dispersion, and waterborne hydroxyl acrylic emulsion. Disperse the mixture with 1000 rpm for 20 minutes. Then, sequentially add water, auxiliary agents, and water-based nano black pigment dispersion. Disperse the mixture with 1500 rpm for 60 minutes. Filter the mixture, discharge the material obtain by filtering, then obtaining the base component of water-based UV coatings.

[0051] (2) Mix the water-based UV coatings' base component obtained with thermal curing agent in a specific proportion until they are thoroughly blended. This will result in the water-based UV coatings.

TABLE-US-00003 TABLE 1 Coating formulations of Example 1~6 of the embodiments of the present invention, parts by weight Example Example Example Example Example Example Component 1 2 3 4 5 6 Water-based 20 20 15 15 12 20 polycarbonate dispersion Water-based aliphatic 40 40 45 45 48 40 polyurethane acrylate dispersion Water-based hydroxyl 10 10 10 15 15 acrylic emulsion (TOD 2AH58W) TMP3EOTA 8 8 8 13 13 8 DPHA 5 5 5 5 (HDDA) Photoinitiator 184 2 2 2 2 2 2 Photoinitiator TPO 0.5 0.5 0.5 0.5 0.5 0.5 Wetting agent Tego 270 0.2 0.2 0.2 0.2 0.2 0.2 Thickener Tego 3030 0.3 0.3 0.3 0.3 0.3 0.3 Water-based nano black 2 2 2 2 2 pigment dispersion Diacetone alcohol 5 5 5 5 5 5 Water 7 7 7 7 7 7 Water-based isocyanate 15 10 15 15 15 curing agent (Aquolin 268)

Comparison Examples 15

[0052] Prepare coatings according to the coating formulations recited in Table 2, the preparation process is the same as that in Examples 1 to 5.

TABLE-US-00004 TABLE 2 Coating formulations of Comparison Examples 1~5, parts by weight Comparison Comparison Comparison Comparison Comparison Component Example 1 Example 2 Example 3 Example 4 Example 5 Water-based 20 20 20 50 polycarbonate dispersion Water-based aliphatic 60 40 40 40 10 polyurethane acrylate dispersion Water-based hydroxy 10 10 10 acrylic emulsion (TOD 2AH58W) TMP3EOTA 8 8 8 8 8 DPHA 5 5 5 5 5 Photoinitiator 184 2 2 2 2 2 Photoinitiator TPO 0.5 0.5 0.5 0.5 0.5 Wetting agent Tego 0.2 0.2 0.2 0.2 0.2 270 Thickener Tego 3030 0.3 0.3 0.3 0.3 0.3 Water-based nano 2 2 2 2 2 black pigment dispersion Diacetone alcohol 5 5 5 5 5 Water 7 7 7 7 7 Water-based 5 isocyanate curing agent (Aquolin 268)

[0053] The coatings prepared in Examples 1 to 5 and Comparison Examples 1 to 5 were sprayed onto black ABS+PC substrates panels. After baking at temperature 60 C. for 15 minutes, UV curing was performed with UV energy of 1000 mJ/cm.sup.2 and a light intensity of 80 mW/cm.sup.2. Subsequently, the panels were baked at temperature of 80 C. for 120 minutes. The performance tests were conducted according to the testing standards specified in Table 3, with a film thickness of 305 m for general performance testing panels and a film thickness of 555 m for crack resistance testing panels.

[0054] The coatings prepared in Example 6 were sprayed onto transparent PC substrate panels. After baking at temperature 60 C. for 15 minutes, UV curing was performed with UV energy of 1000 mJ/cm.sup.2 and a light intensity of 80 mW/cm.sup.2. The performance tests were conducted according to the testing standards specified in Table 3, with a film thickness of 305 m for general performance testing panels and a film thickness of 555 m for crack resistance testing panels.

[0055] The test results are shown in Table 4, indicating that the coatings of the present invention exhibit a good balance between wear resistance and crack resistance, while also meets the testing requirements of the VW TL226.

TABLE-US-00005 TABLE 3 Performance Testing Standards and Requirements Tests Test standard/method Requirements Wear resistance of high TL226-2018-04 15% gloss surface PV3987 Cracking resistance Spray the coatings with film thickness no cracking of 55 5 m, bake it at 90 C. for 7 days after cutting X, observe the cracking condition Adhesion TL226-2020-10 level 1 D N E N ISO 2409 Thermal aging under high TL226-2020-10 no change in appearance, temperature and adhesion level 1. Condensation atmosphere TL226-2020-10 no change in appearance with constant humidity D N E N ISO 6270-2 and adhesion level 1. Hydrolysis aging TL226-2020-10 no change in appearance and adhesion level 1. Cream resistance TL226-2020-04 no change in appearance, PV3964 and adhesion is level 1.

TABLE-US-00006 TABLE 4 Performance Test Results for Examples 1-6 Example Example Example Example Example Example Tests 1 2 3 4 5 6 Adhesion 0 level 0 level 0 level 0 level 0 level 0 level Wear resistance of high 10% 10% 6% 10% 8% 13% gloss surface Cracking resistance no no no no no no cracking cracking cracking cracking cracking cracking Thermal Appearance no no no no no no aging under change change change change change change high Adhesion level 0 level 0 level 0 level 0 level 0 level 0 temperature Condensation Appearance no no no no no no atmosphere change change change change change change with constant Adhesion level 0 level 0 level 0 level 0 level 0 level 0 humidity Resistance to Appearance no no no no no no hydrolysis change change change change change change aging Adhesion level 0 level 0 level 0 level 0 level 0 level 0 Cream Appearance no no no no no no resistance change change change change change change

TABLE-US-00007 TABLE 5 Performance Test Results for Comparison Examples 1-5 Comparison Comparison Comparison Comparison Comparison Test Example 1 Example 2 Example 3 Example 4 Example5 Adhesion 1 level 0 level 0 level 0 level 0 level Wear resistance of high 6% 7% 8% 9% 30% gloss surface Cracking resistance serious serious serious serious no cracking cracking cracking cracking cracking Thermal Appearance no change no change no change no change no change aging under Adhesion level 2 level 0 level 0 level 0 level 0 high temperature Condensation Appearance no change no change no change no change no change atmosphere Adhesion level 3 level 0 level 0 level 0 level 0 with constant humidity Resistance Appearance blister no change no change no change no change to hydrolysis Adhesion level 5 level 0 level 0 level 0 level 0 aging Cream Appearance no change no change no change no change wrinkling resistance

[0056] Comparison Example 1: the coating formulation of the Comparison Example 1 does not comprise the water-based polycarbonate dispersion, and it was observed that after curing, the resistance to hydrolytic aging decreased, and the adhesion becomes poor.

[0057] Comparison Example 2: the coating formulation of the Comparison Example 2 does not comprise the water-based hydroxyl acrylic emulsion, and thermal curing agent was not used in this Comparison Example 2 for thermal curing, thus only UV curing was performed. After curing, it was observed that the coating film exhibited cracking issues.

[0058] Comparison Example 3: the coating formulation of the Comparison Example 3 does not comprise the water-based isocyanate curing agent for thermal curing, and it was observed that the coating film exhibited severe cracking issues after curing.

[0059] Comparison Example 4: the water-based isocyanate curing agent was added in an amount of 5 parts in weight, and it was observed that the coating film exhibited severe cracking issues after curing.

[0060] Comparison Example 5: the ratio of water-based polycarbonate dispersion to water-based aliphatic polyurethane acrylate dispersion is beyond the specified range of the technical solution of the present invention, with a higher content of water-based polycarbonate dispersion and without the addition of water-based isocyanate curing agent for thermal curing. After curing, it was observed that the coating film did not exhibit cracking (possessing flexibility). However, the wear resistance test's result of its high gloss surface was 30%, which exceeds the 15% requirement range of the Volkswagen TL226 test.

[0061] The descriptions of the embodiments mentioned above are provided to facilitate the understanding and utilization of the invention by those skilled in the art. It is understood that one skilled in the art can make appropriate changes and modifications to the disclosed embodiments. Therefore, the present invention is not limited to the specific embodiments disclosed and described above, and any modifications and changes to the present invention are also covered by the protection scope of the claims of the present invention.

[0062] It should be noted that, the above embodiments are merely illustrative examples adopted to explain the principles of the present invention. However, the present invention is not limited thereto. One skilled in the art can make various modifications and improvements without departing from the spirit and essence of the present invention. Such modifications and improvements are also considered to be covered by the scope of protection of the present invention.