UV (ultraviolet) curing PVD (physical vapor deposition) coating primer suitable for imitated crystal base material

Abstract

The invention provides a UV (ultraviolet) curing PVD (physical vapor deposition) coating primer applicable to an imitated crystal substrate, which comprises the following raw material components: 10-40 parts by weight of unsaturated polyurethane resin; 15-40 parts by weight of an acrylate monomer; 3 to 15 parts by weight of functional thermoplastic resin; 1-5 parts by weight of a photoinitiator; 0.05 to 1 part by weight of an auxiliary agent; and 30-55 parts by weight of a solvent. The invention further provides a preparation method of the UV curing PVD coating primer for the imitated crystal base material. The UV curing PVD coating primer suitable for the imitated crystal base material can be applied to the fields of automobile interior and exterior decoration and the like which are difficult to adhere to imitated crystal plastic base materials such as Mitsubishi DURABIOTM bio-based PC (Polycarbonate) and PMMA (Polymethyl Methacrylate). The invention further provides an application method of the UV curing PVD coating primer suitable for the imitated crystal base material on the base material.

Description

Technical Field

[0001] The present invention relates to the field of photocurable coatings, specifically, to UV-curable PVD coating primers, and more specifically, to UV-curable PVD coating primers suitable for substrates that are difficult to adhere to, such as imitation crystal plastic substrates. Background Art

[0002] Natural crystal presents a unique optical effect of crystal clear due to the regular arrangement of its crystal structure. When applied to automotive decorative parts, it can have aesthetic appearance, a sense of high-class and luxury. However, natural crystal has high cost, difficult processing, high brittleness and is easy to break, thus it cannot be applied on a large scale. In contrast, plastic substrates such as bio-based polycarbonate (PC) and acrylic (PMMA) also have a decorative appearance effect similar to that of crystal. In addition, they have low cost, easy processing, relatively low brittleness and are not easy to break. Therefore, imitation crystal plastic substrates are gradually being applied on a large scale in fields such as automotive interior and exterior decorations, such as: crystal gear knob / shift lever, crystal knob / button, crystal seat adjuster, crystal atmosphere light strip, crystal car logo, crystal car lamp, etc. However, these imitation crystal plastic substrates (such as: Mitsubishi DURABIO TM bio-based PC) usually have characteristics such as high surface hardness (pencil hardness 1H - 2H) and solvent corrosion resistance. It is very difficult to adhere PVD coating primer on their surfaces, and subsequent PVD processes such as evaporation aluminizing or evaporation chroming cannot be achieved, thus it is difficult to meet the requirements of increasingly diversified and colorful decorative appearance effects in fields such as automotive interior and exterior decorations.

[0003] Currently, the adhesion performance of UV-curable PVD coating primers of other coating manufacturers on the market to imitation crystal plastic substrates such as Mitsubishi DURABIO TM bio-based PC and PMMA is not good enough. For example, the UV-curable primer KY-V21-0054G-1 of coating manufacturer A has no initial adhesion on these substrates. After spraying treatment agent P-29A and then spraying this primer, it can have an initial adhesion of 4B. However, the performance of the final coating such as boiling water resistance (100°C, 2h), hydrolysis resistance (90°C & 96% RH, 72h), moisture resistance (40°C & 100% RH, 240h), etc. still cannot be met, showing test failure. The initial adhesion of the UV-curable primer UV-1376 of coating manufacturer B is 5B, but the other properties of the final coating are unstable, and some show test failure.

[0004] As is well known, automobiles have particularities. They are not consumables in the traditional sense, and their interior and exterior parts are required to have a long service life. Therefore, the PVD coatings of the above coating manufacturers have great performance risks, which will directly affect the reputation, revenue of automobile manufacturers and the usage experience of consumers, etc. Therefore, developing high-performance PVD coatings that can meet the requirements of difficult-to-adhere imitation crystal substrates in fields such as automotive interior and exterior decorations is of great significance for the development and upgrading of the automotive industry and the improvement of consumers' usage experience, etc. Summary of the Invention

[0005] In order to solve the above-mentioned deficiencies of the prior art, the present invention provides a UV-curable PVD coating primer suitable for imitation crystal substrates, which comprises the following components (by weight):

[0006]

[0007] Optionally, the weight-average molecular weight range of the unsaturated polyurethane resin is 2000-10000, and the functionality is 2-6. The ratio of the rigid segment and the flexible segment in the structure of the unsaturated polyurethane resin is appropriate, which can regulate the flexibility of the primer and at the same time endow the primer with good plating properties.

[0008] Preferably, the unsaturated polyurethane resin comprises two unsaturated polyurethane resins with different functionalities. More preferably, the unsaturated polyurethane resin comprises a 2-functional unsaturated polyurethane resin and a 6-functional unsaturated polyurethane resin.

[0009] Optionally, the average functionality of the acrylate monomer is 2-4. By selecting acrylate monomers with different functionalities and using them in combination, the crosslinking density after UV curing can be prevented from being too high or too low, avoiding potential performance risks.

[0010] Optionally, the acrylate monomer is one or more of dipentaerythritol hexaacrylate (DPHA), ditrimethylolpropane tetraacrylate (DI-TMPTA), trimethylolpropane triacrylate (TMPTA), ethoxylated trimethylolpropane triacrylate (3EO-TMPTA), pentaerythritol triacrylate (PETA), ethoxylated (5) pentaerythritol tetraacrylate (5EO-PETA), 1,6-hexanediol diacrylate (HDDA), neopentyl glycol diacrylate (NPGDA), propoxylated neopentyl glycol acrylate (NPG2PODA), 2-hydroxyethyl methacrylate (HEMA), 2-phenoxyethyl acrylate (PHEA), tetrahydrofurfuryl acrylate (THFA).

[0011] Optionally, the functional thermoplastic resin is one or more of acrylic resin, epoxy resin, polyester resin, chlorinated polyolefin resin.

[0012] Optionally, the dosage of the functional thermoplastic resin is 3-10 parts by weight. Adding the functional thermoplastic resin can effectively improve the adhesion of the primer to the difficult-to-adhere imitation crystal substrate. At the same time, it can also regulate the crosslinking density after UV curing of the unsaturated polyurethane resin and the acrylate monomer, improving the comprehensive performance of the paint film.

[0013] Optionally, the photoinitiator is one or more of hydroxycyclohexyl phenyl ketone (184), 2,2-dimethyl-2-hydroxyacetophenone (1173), 2,4,6-trimethylbenzoyl diphenyl phosphine oxide (TPO), ethyl 2,4,6-trimethylbenzoylphosphinate (TPO-L), 2,4,6-trimethylbenzoyl-bis(p-tolyl) phosphine oxide (TMO), 2,2-dimethoxy-2-phenylacetophenone (651), methyl benzoylformate (MBF), bis(2,4,6-trimethylbenzoyl)phenylphosphine oxide (819).

[0014] Optionally, the dosage of the photoinitiator is 2 to 4 parts by weight. Selecting the appropriate type and dosage of the photoinitiator can effectively improve the curing rate of the paint film, and a good balance can be achieved between surface curing and deep curing, improving the comprehensive performance of the paint film.

[0015] Optionally, the additive is one or more of silicone, fluorinated acrylic acid, acrylic acid.

[0016] Optionally, the dosage of the additive is 0.1 to 0.5 parts by weight. This type of additive will affect the surface polarity of the paint film. When the content is too high, the surface polarity will decrease, resulting in poor plating performance of the primer, that is: the adhesion of the metal coating to the primer will become poor. Preferably, the additive is acrylic acid-based, and this type of additive has a relatively high surface polarity, which is beneficial to improving the plating performance.

[0017] Optionally, the solvent includes but is not limited to two or more of ethyl acetate, butyl acetate, diacetone alcohol, cyclohexanone, methyl ethyl ketone.

[0018] Optionally, the UV-curable PVD coating primer provided by the present invention comprises the following components (by weight):

[0019]

[0020] The present invention also provides the application of the above-mentioned UV-curable PVD coating primer in the fields of automotive interior and exterior trim of difficult-to-adhere bio-based PC, PMMA and other imitation crystal plastic substrates such as Mitsubishi DURABIO TM and the like.

[0021] The present invention also provides a method for the application of the above-mentioned UV-curable PVD coating primer in the fields of automotive interior and exterior trim, etc., comprising the following steps:

[0022] Step 1, spray the above-mentioned UV-curable PVD coating primer on automotive interior and exterior trim parts made of imitation crystal plastic substrates such as Mitsubishi DURABIO TM bio-based PC, PMMA, etc., and cure it into a film by UV curing;

[0023] Step 2: After the UV-curable PVD coating primer forms a film, it is paired with an environmentally friendly PVD process (such as evaporation aluminizing or evaporation chroming), and a metal coating is deposited on the cured primer film.

[0024] Step 3: On the metal coating such as aluminum or chromium, a high-performance PVD topcoat is sprayed and cured into a film through UV.

[0025] Optionally, inorganic nanoparticles (silica) modified by surface functional groups can be added to the coating or coating system of the present invention. After being hybrid-modified, the inorganic nanoparticles can improve the dispersibility and compatibility with the resin. By adding the hybrid-modified inorganic nanoparticles, the hardness and wear resistance can be further enhanced while ensuring transparency.

[0026] Compared with the prior art, the technical solution of the present invention has at least the following technical effects:

[0027] The UV-curable PVD coating primer described in the present invention is applied to the field of vacuum evaporation coating. This coating primer has excellent adhesion to difficult-to-adhere imitation crystal plastic substrates such as Mitsubishi DURABIO TM bio-based PC and PMMA, and has good plating properties.

[0028] After the UV-curable PVD coating primer of the present invention forms a film through UV curing, it is paired with an environmentally friendly PVD process (such as evaporation aluminizing or evaporation chroming) and a high-performance PVD topcoat. The final coating can meet performance tests such as boiling water resistance (100 °C, 2 h), hydrolysis resistance (90 °C, 96% RH, 72 h), and moisture resistance (40 °C, 100% RH, 240 h), and the adhesion is 5B for all. Specific Embodiments

[0029] The following specific examples are used to illustrate the implementation manners of the present invention, but the present invention is not limited thereto.

[0030] According to the ingredient list in Table 1, Examples 1-3 of the present invention are prepared.

[0031] Step 1: Mix photoinitiator 184, BYK-358N, and ethyl acetate, and disperse for 15 minutes to obtain Component I;

[0032] Step 2: Mix unsaturated polyurethane resin, dipentaerythritol hexaacrylate (DPHA), pentaerythritol triacrylate (PETA), 1,6-hexanediol diacrylate (HDDA), neopentyl glycol diacrylate (NPGDA), functional thermoplastic resin, and butyl acetate evenly, and disperse for 30 minutes to obtain Component II;

[0033] Step 3: Add Component I to Component II while stirring, control the operating temperature at 20-50 °C, and disperse for 60 minutes until evenly mixed.

[0034] Table 1. Composition of PVD coating primer in the embodiments of the present invention (by weight)

[0035] Example 1 Example 2 Example 3 Two-functional unsaturated polyurethane resin 32 15 20 Six-functional unsaturated polyurethane resin 5 2 4 DPHA 10 4 6 PETA 7 10 13 NPGDA 3 8 7 HDDA 2 3 5 Functional thermoplastic resin 5 5 8 Photoinitiator 184 3 3 3 BYK-358N 0.2 0.2 0.2 Solvent 32.8 49.8 33.8

[0036] Among them, the solvent is a mixture of ethyl acetate and butyl acetate.

[0037] Comparative Examples 1-3 are the coating solutions of Coating Manufacturer A and Coating Manufacturer B. See Table 2 for details.

[0038] Table 2. PVD coating primer solutions of Comparative Examples 1-3

[0039] Comparative Example 1 Comparative Example 2 Comparative Example 3 Treatment agent - P29-A - UV-curable primer KY-V21-0054G-1 KY-V21-0054G-1 UV-1376 Source Coating manufacturer A Coating manufacturer A Coating manufacturer B

[0040] The PVD coating primers of Examples 1-3 and Comparative Examples 1-3 were made into plates for coating performance testing. The method is as follows:

[0041] 1. Spray the PVD coating primers prepared in the examples and comparative examples on the Mitsubishi DURABIO TM bio-based PC substrate and cure it into a film by UV curing (energy 600-1200 mJ / cm 2 , light intensity 50-150 mW / cm 2 );

[0042] 2. Evaporate aluminum by a vacuum coating machine;

[0043] 3. Spray the PVD coating topcoat on the metal aluminum coating and cure it into a film by UV curing (energy 800-1500 mJ / cm 2 , light intensity 50-150 mW / cm 2 ) to make a test sample.

[0044] Performance testing method:

[0045] 1. Adhesion: According to ASTM D3359-1997, perform cross-cutting by the cross-hatch method on the final coating (primer + metal coating + topcoat) of the sample to measure the adhesion. If the adhesion ≥ 4B, it is judged as qualified; if the adhesion < 4B, it is judged as failed.

[0046] 2. Boiling water resistance: Place the sample in a water bath at 100 °C for 2 hours, take it out and cool it naturally to room temperature, then perform cross-cutting on the surface of the sample coating to measure the adhesion.

[0047] 3. Hydrolysis resistance: Place the sample in a constant temperature and humidity chamber at 90 °C & 96% RH for 72 hours, take it out and cool it naturally to room temperature, then perform cross-cutting to measure the adhesion.

[0048] 4. Moisture resistance: Place the sample plate in a condensation water tank at 40°C and 100% RH for 240 hours. After taking it out, let it cool naturally to room temperature, make cross-cuts, and measure the adhesion.

[0049] The performance test results of the examples and comparative examples are shown in Table 3 in detail.

[0050] Table 3. Coating properties of Examples 1-3 and Comparative Examples 1-3

[0051] Test items Example 1 Example 2 Example 3 Comparative Example 1 Comparative Example 2 Comparative Example 3 Initial adhesion 5B 5B 5B 0B 4B 5B Water resistance after boiling 5B 5B 5B 0B 2-3B 3-4B Hydrolysis resistance 5B 5B 5B 0B 2-3B 3-4B Moisture resistance 5B 5B 5B 0B 3-4B 4B

[0052] It can be seen from the performance test results in Table 3 that:

[0053] The UV-curable PVD coating primer according to Examples 1-3 of the present invention is combined with an environmentally friendly PVD process (such as evaporation aluminizing or evaporation chroming) and a high-performance PVD topcoat. The initial adhesion of the final coating is 5B for all. Moreover, after performance tests such as boiling water resistance (100°C, 2h), hydrolysis resistance (90°C, 96% RH, 72h), and moisture resistance (40°C, 100% RH, 240h), the adhesion is 5B for all. Therefore, the UV-curable PVD coating primer of the present invention has excellent adhesion to difficult-to-adhere imitation crystal plastic substrates such as Mitsubishi DURABIO TM bio-based PC, PMMA, etc.

[0054] Different from the PVD coating primer prepared by the present invention, in Comparative Example 1 of Coating Manufacturer A, without the combination of a treatment agent, the initial adhesion and the adhesion after performance tests such as boiling water resistance, hydrolysis resistance, and moisture resistance are all 0B; while in Comparative Example 2 with the combination of a treatment agent, the initial adhesion is 4B, but the performance tests such as boiling water resistance, hydrolysis resistance, and moisture resistance all show failure. In Comparative Example 3 of Coating Manufacturer B, the initial adhesion and the adhesion after moisture resistance test are 4B, but the performance tests such as boiling water resistance and hydrolysis resistance all show failure. Generally speaking, the adhesion of Comparative Examples 1-3 to difficult-to-adhere imitation crystal plastic substrates such as Mitsubishi DURABIO TM bio-based PC, PMMA, etc. is inferior to that of the UV-curable PVD coating primer of the present invention.

[0055] Although embodiments of the present invention are described herein, it will be understood by those of ordinary skill in the art that various changes, modifications, substitutions, and variations can be made to these embodiments without departing from the principles and spirit of the present invention. The protection scope of the present invention is defined by the appended claims and their equivalent substitutions.

Claims

1. A UV-curable PVD coating primer applicable to imitation crystal substrates, characterized in that, By weight, it includes the following raw material components:

2. The UV curable PVD coating primer applicable to the imitation crystal substrate according to claim 1, characterized in that, The weight-average molecular weight range of the unsaturated polyurethane resin is 2000 - 10000, and the functionality is 2 - 6.

3. The UV-curable PVD coating primer applicable to the imitation crystal substrate according to claim 1, characterized in that, The unsaturated polyurethane resin includes two kinds of unsaturated polyurethane resins with different functionalities.

4. The UV-curable PVD coating primer applicable to the imitation crystal substrate according to claim
, wherein, The unsaturated polyurethane resin includes a 2-functional unsaturated polyurethane resin and a 6-functional unsaturated polyurethane resin.

5. The UV-curable PVD coating primer applicable to the imitation crystal substrate according to claim 1, characterized in that, The average functionality of the acrylate monomer is 2 - 4.

6. The UV-curable PVD coating primer applicable to the imitation crystal substrate according to claim 1, characterized in that The functional thermoplastic resin is one or more of acrylic resin, epoxy resin, polyester resin, and chlorinated polyolefin resin.

7. The UV-curable PVD coating primer applicable to the imitation crystal substrate according to claim 1, wherein The photoinitiator is one or more of hydroxycyclohexyl phenyl ketone (184), 2,2-dimethyl-2-hydroxyacetophenone (1173), 2,4,6-trimethylbenzoyl diphenylphosphine oxide (TPO), ethyl 2,4,6-trimethylbenzoylphosphinate (TPO-L), 2,4,6-trimethylbenzoyl-bis(p-tolyl)oxide (TMO), 2,2-dimethoxy-2-phenylacetophenone (651), methyl phenylglyoxylate (MBF), bis(2,4,6-trimethylbenzoyl)phenylphosphine oxide (819).

8. The UV-curable PVD coating primer applicable to the imitation crystal substrate according to claim 1, characterized in that, The auxiliary agent is one or more of silicone, fluorinated acrylic acid, and acrylic acid.

9. The UV-curable PVD coating primer applicable to the imitation crystal substrate according to claim 1, characterized in that, By weight, it includes the following raw material components:

10. A preparation method of a UV-curable PVD coating primer applicable to a simulated crystal substrate, comprising the following steps: Step 1: Mix the photoinitiator, auxiliary agent, and solvent, and disperse for 15 minutes to obtain Component I; Step 2: Mix the unsaturated polyurethane resin, acrylate monomer, functional thermoplastic resin, and solvent evenly, and disperse for 30 minutes to obtain Component II; Step 3: Add Component I to Component II while stirring, control the operating temperature at 20 - 50 °C, and disperse for 60 minutes until evenly mixed.

11. Application of the UV-curable PVD coating primer for imitation crystal substrates as claimed in claim 1 in the fields of interior and exterior automotive trims and the like made of bio-based PC, PMMA and other imitation crystal plastic substrates such as Mitsubishi DURABIO TM ​ 12. An application method of the UV-curable PVD coating primer described in Claim 1 applicable to a simulated crystal substrate, comprising the following steps: Step 1. On automotive interior and exterior decorative parts made of bio-based PC, PMMA and other imitation crystal plastic substrates such as Mitsubishi DURABIO TM spray the UV-curable PVD coating primer applicable to the imitation crystal substrate according to any one of claims 1 to 9, and cure it into a film by UV curing; Step 2: After the UV-curable PVD coating primer is cured into a film, through the PVD process, deposit a metal coating on the cured film; Step 3: Spray a UV-curable PVD coating topcoat on the metal coating formed in Step 2, and cure it into a film by UV curing.

Images