Vacuum plating finish paint for automotive upholstery as well as preparation method and application of vacuum plating finish paint

Abstract

The invention belongs to the technical field of finish paint, and particularly relates to vacuum plating finish paint for automotive upholstery and a preparation method and application thereof.The finish paint comprises, by weight, 5-15 parts of hexa-functional polyurethane acrylate, 5-15 parts of bifunctional polycarbonate modified acrylic resin and 15-30 parts of tetrafunctional polyurethane acrylate, the coating is prepared from the following components in parts by weight: 3-8 parts of monofunctional monomer isobornyl acrylate, 0.1-0.5 part of trifunctional phosphate, 0.1-0.5 part of a flatting agent, 3-5 parts of a photosensitizer and 40-50 parts of a solvent. Compared with the prior art, the finish paint solves the problem that the finish paint formula taking 6 / 9-functional-group PUA resin and 4-functional-group solvent type PUA resin as a main body and matched with the TMPTA monomer and the phosphate ester auxiliary agent cannot meet the performance requirement of the depth test of the automotive interior trim part in the prior art. The scheme aims to improve the deep test requirements of vacuum plating UV boiling resistance, hydrolysis resistance, aging resistance and the like of the automotive upholstery.

Description

Technical Field

[0001] The invention belongs to the technical field of topcoats, and in particular relates to a vacuum electroplating topcoat for automobile interior decoration parts and a preparation method and application thereof. Background Art

[0002] The vacuum plating technology used in automotive interior parts refers to the deposition of a certain metal or metal compound in the form of gas phase onto the surface of plastic materials under vacuum environment. It belongs to the physical vapor deposition process. Vacuum coating is divided into two processes: thermal evaporation coating and magnetron sputtering coating, according to the different ways of producing and depositing the gas phase metal. Among them, magnetron sputtering has the advantages of denser and more uniform coating layer and better comprehensive performance compared with thermal evaporation coating.

[0003] As environmental protection requirements become increasingly stringent, water-plated products in automotive interior parts will be gradually replaced by vacuum-plated parts. In addition, people have higher and higher requirements for the texture and beauty of automotive interiors. Automotive interior parts made with vacuum plating technology can give plastics a metallic texture, so the application of interior parts prepared by this technology in automobiles has increased year by year. The vacuum plating process can add metal elements to automotive interior panels, enhance the texture and taste, and create a sense of modern technology and luxury. Shift handles, steering wheel decorative rings, control panels, center console decorative parts, handbrake handles and shift levers, practical buttons and switches, panel trims, etc. can all be surface-treated with vacuum plating technology to obtain extremely high metallic texture, which can enhance driving comfort and overall visual effects, especially in new energy vehicles.

[0004] UV vacuum coating topcoat is applied on vacuum electroplating midcoat or metal coating. Its function is to protect the coating or midcoat, provide good adhesion and hardness, anti-scratch, anti-scratch and depth test performance. Vacuum coating topcoat must have excellent adhesion to both the coating and the midcoat. In some applications, color paste will be directly added to the topcoat, which requires the topcoat to have good curing performance, as well as good leveling and fullness.

[0005] Traditional vacuum electroplating topcoat for automotive interior parts is based on 6 / 9-official polyurethane acrylate (PUA) and 4-official solvent-based PUA resin, and is combined with trimethylolpropane triacrylate (TMPTA) monomer and phosphate ester additives to improve leveling and hardness. For example, CN112708343A discloses a vacuum electroplating topcoat and its preparation method and application, and CN116731603A discloses a vacuum electroplating laser carving protective paint and its preparation method and application. The appearance effect and conventional adhesion of this formula can meet the performance requirements, but discoloration will occur during depth tests such as hydrolysis and aging tests. The adhesion after the depth test is unstable and cannot meet the performance test requirements of automotive interior parts. Summary of the invention

[0006] The purpose of the present invention is to provide a vacuum electroplating topcoat for automotive interior parts, a preparation method and an application thereof in order to solve at least one of the above problems, and to solve the problem that the topcoat formula based on 6 / 9-official PUA and 4-official solvent-based PUA resins in the prior art, combined with TMPTA monomer and phosphate ester additives, cannot meet the performance requirements of the depth test of automotive interior parts. This solution uses hexafunctional polyurethane acrylate, difunctional polycarbonate modified acrylate resin, tetrafunctional polyurethane acrylate, and monofunctional monomer acrylate isobornyl for photocuring polymerization and crosslinking, so that the prepared topcoat has a smoother and fuller surface effect, interlayer adhesion, as well as water resistance and aging performance, aiming to improve the depth test requirements of automotive interior parts such as UV boiling resistance, hydrolysis resistance, and aging resistance by vacuum electroplating.

[0007] The purpose of the present invention is achieved through the following technical solutions:

[0008] The first aspect of the present invention discloses a vacuum electroplating topcoat for automotive interior decoration parts, comprising the following components in parts by weight:

[0009] 5-15 parts of hexafunctional polyurethane acrylate, 5-15 parts of difunctional polycarbonate modified acrylic resin, 15-30 parts of tetrafunctional polyurethane acrylate, 3-8 parts of monofunctional monomer isobornyl acrylate (IBOA), 0.1-0.5 parts of trifunctional phosphate, 0.1-0.5 parts of leveling agent, 3-5 parts of photosensitizer, and 40-50 parts of solvent.

[0010] Here, hexafunctional means having six functional groups, difunctional means having two functional groups, and so on.

[0011] Preferably, the viscosity of the hexafunctional polyurethane acrylate at 25° C. is 30,000-40,000 mPa·s.

[0012] Preferably, the viscosity of the difunctional polycarbonate modified acrylic resin at 25° C. is 20,000-30,000 mPa·s, and the molecular weight of the monofunctional isobornyl acrylate is 208, and the viscosity at 25° C. is 5-15 mPa·s.

[0013] Preferably, the viscosity of the tetrafunctional polyurethane acrylate at 25° C. is 5000-8000 mPa·s.

[0014] Preferably, the trifunctional phosphate is Sartomer SR9051NS.

[0015] Preferably, the leveling agent is polyester-modified polydimethylsiloxane containing acrylic functional groups, specifically BYK371.

[0016] Preferably, the photosensitizer is 1-hydroxycyclohexyl phenyl ketone and 2,4,6-trimethylbenzoyl diphenyl phosphine oxide.

[0017] Preferably, the solvent is ethyl acetate, butyl acetate, propylene glycol methyl ether acetate, methyl isobutyl ketone, etc.

[0018] Preferably, the following components are included in parts by weight:

[0019] 12 parts of hexafunctional polyurethane acrylate, 8 parts of difunctional polycarbonate modified acrylic resin, 25 parts of tetrafunctional polyurethane acrylate, 5 parts of monofunctional isobornyl acrylate, 0.5 parts of trifunctional phosphate, 0.3 parts of leveling agent, 3.8 parts of photosensitizer, and 45.4 parts of solvent.

[0020] The second aspect of the present invention discloses a method for preparing a vacuum electroplating topcoat for automotive interior decoration parts as described above, comprising the following steps: stirring and mixing the formula components to obtain the topcoat.

[0021] The third aspect of the present invention discloses an application of any of the above-mentioned vacuum electroplating topcoats for automotive interior decoration parts, wherein the topcoat is used for a coating surface or a mid-paint surface.

[0022] Preferably, the coating is mainly composed of metal coatings such as aluminum and indium.

[0023] Preferably, the forming of topcoat on the surface of the coating or intermediate paint comprises the following steps:

[0024] Clean the surface of the coating or midcoat (wipe it), then spray the mixed topcoat to form a semi-finished topcoat, and finally dry it (leveling at room temperature for 2-5 minutes; IR baking at 60-65℃, 5-8 minutes; UV curing energy: 1000-1300mJ / cm 2 ).

[0025] Compared with the prior art, the present invention has the following beneficial effects:

[0026] The vacuum electroplating topcoat for automotive interior parts provided by the present invention is a protective coating used on the surface of the coating or the intermediate coating, which seals the plastic substrate to prevent the volatile substances in the substrate from affecting the quality of the coating during vacuum electroplating. The plastic surface is relatively rough, and a smooth mirror effect can be obtained by spraying the topcoat, which is conducive to obtaining a thicker and more uniform vacuum electroplating coating, showing a higher metallic luster and reflection effect. For some substrates with lower polarity, the transition of the topcoat can make the vacuum electroplated metal coating obtain better adhesion performance.

[0027] Vacuum plating topcoat for automotive interior parts also has the following advantages:

[0028] 1) Compared with the traditional vacuum plating topcoat, the present invention uses a monofunctional monomer IBOA, which greatly improves the adhesion of the topcoat and the flexibility of the paint film, especially the adhesion to plastic materials (mainly PC, ABS, PC+ABS, etc.), and the surface is smooth, full and flexible;

[0029] 2) The introduction of difunctional polycarbonate acrylate can not only improve the adhesion of the paint film, but also improve the deep testing properties of the paint film such as hydrolysis resistance and aging performance;

[0030] 3) The vacuum electroplating topcoat for automotive interior parts has a simple preparation process and has the advantages of low odor, no toluene, no halogen, no heavy metal, etc. It complies with the RoHS standard and has little harm to the environment. DETAILED DESCRIPTION

[0031] The present invention is described in detail below with reference to specific embodiments, but this is by no means a limitation of the present invention.

[0032] In the following description, unless otherwise specified, the reagents used are conventional commercially available products and the methods used are well-known means.

[0033] A vacuum electroplating topcoat for automobile interior decoration parts, comprising the following components in parts by weight:

[0034] 5-15 parts of hexafunctional polyurethane acrylate, 5-15 parts of difunctional polycarbonate modified acrylic resin, 15-30 parts of tetrafunctional polyurethane acrylate, 3-8 parts of monofunctional monomer isobornyl acrylate, 0.1-0.5 parts of trifunctional phosphate, 0.1-0.5 parts of leveling agent, 3-5 parts of photosensitizer, and 40-50 parts of solvent.

[0035] A method for preparing the vacuum electroplating topcoat for automobile interior decoration parts as described above comprises the following steps: stirring and mixing the formula components evenly to obtain the topcoat.

[0036] An application of the vacuum electroplating topcoat for automobile interior decoration parts as described above, wherein the topcoat is used for a coating surface or a mid-paint surface.

[0037] Example 1

[0038] A vacuum electroplating topcoat for automobile interior decoration parts, which consists of the following components in parts by weight:

[0039] 12 parts of hexafunctional polyurethane acrylate; 8 parts of difunctional polycarbonate modified acrylic resin; 25 parts of tetrafunctional polyester acrylate; 5 parts of monofunctional monomer IBOA; 0.5 parts of trifunctional phosphate; 0.3 parts of leveling agent; 3.8 parts of photosensitizer; 45.4 parts of solvent.

[0040] The hexafunctional polyurethane acrylate has a solid content of 100% and a viscosity of 30,000-40,000 mPa·s / 25°C (i.e., the viscosity measured at 25°C), the difunctional polycarbonate-modified acrylic resin has a solid content of 100% and a viscosity of 20,000-30,000 mPa·s / 25°C, the tetrafunctional polyester acrylate resin has a solid content of 100% and a viscosity of 5,000-8,000 mPa·s / 25°C, the monofunctional monomer IBOA has a molecular weight of 208 and a viscosity of 5-15 mPa·s / 25°C, the trifunctional phosphate is Sartomer SR9051NS, the leveling agent is polyester-modified polydimethylsiloxane containing acrylic functional groups, specifically BYK371, and the photosensitizer is 1-hydroxycyclohexyl phenyl ketone and 2,4,6-trimethylbenzoyl diphenyl phosphine oxide.

[0041] The above components are added into a container according to the weight of the formula, and mixed evenly under stirring conditions to obtain a vacuum electroplating topcoat for automotive interior parts. The physical properties of the topcoat are shown in Table 2.

[0042] Embodiment 2-4:

[0043] The preparation process is the same as that of Example 1, the formulation composition is shown in Table 1, and the physical property indicators are shown in Table 2.

[0044] Comparative Examples 1-5:

[0045] In the production process, except that the difunctional polycarbonate-modified acrylic resin is not added and TMPTA is used to replace IBOA, the other steps are the same as those in Example 1. The formulation composition is shown in Table 1, and the physical property indicators are shown in Table 2.

[0046] Table 1 Formula composition of Examples 1-4 and Comparative Examples 1-5 (parts by weight)

[0047]

[0048] In Table 1, the trifunctional monomer TMPTA is selected from Changxing EM231.

[0049] The components of Examples 1-4 and Comparative Examples 1-5 in Table 1 were added into a container according to the formula ratio, mixed evenly under stirring conditions, and then constructed according to the following process and parameters.

[0050] Process sequence:

[0051] Substrate cleaning → spraying → IR baking → UV curing process parameters:

[0052] Film thickness: 20-25μm;

[0053] Cumulative UV energy: 1000-1300mJ / cm 2 ;

[0054] Spectral range: 180-420nm;

[0055] UV lamp power: 80-120W / cm;

[0056] IR temperature: 60-65℃, time 5-8min.

[0057] The topcoats obtained in Examples 1-4 and Comparative Examples 1-5 were coated on the surface of the coating or the midcoat, and their adhesion, water boiling and hydrolysis properties were measured according to the Volkswagen TL 226 test standard. The results are shown in Table 2.

[0058] Table 2 Performance test results of Examples 1-4 and Comparative Examples 1-5

[0059]

[0060] It can be seen from Table 2 that the vacuum electroplating topcoats for automotive interior parts prepared by Examples 1-4 can reach 5B adhesion after testing; while the topcoats formed by the formulations of Comparative Examples 1-5 can also reach 5B, but the boiling and hydrolysis test performances of the comparative examples cannot pass. This shows that the present invention adds difunctional polycarbonate-modified acrylate and monofunctional monomer IBOA, and controls the addition amounts within the range of 5-15 parts by weight and 3-8 parts by weight, respectively, to form a topcoat film with good boiling and hydrolysis resistance.

[0061] In addition, the topcoats prepared in Examples 1-4 all passed the boiling water resistance test and the hydrolysis resistance test; while the topcoats obtained in Comparative Examples 1-5 all failed to pass the boiling water resistance and hydrolysis resistance test. This also shows that the present invention can obtain better boiling water resistance and hydrolysis resistance by selectively adding difunctional polycarbonate acrylate and monofunctional monomer IBOA than the formulation based on tetrafunctional polyurethane acrylate and trifunctional monomer TMPTA.

[0062] By comparing the above results, it can be seen that the topcoats prepared in Examples 1-4 of the present invention have more excellent adhesion and water resistance; it also shows that when preparing UV curing coating topcoats, difunctional polycarbonate modified acrylate can greatly improve the water resistance of the paint film, and the monofunctional monomer IBOA can well improve the adhesion of the paint film. When it is not added or added in too little, it will affect the water resistance and adhesion of the topcoat. When its content is controlled in the range of 5-15 parts by weight and 3-8 parts by weight, respectively, it can achieve the best water resistance and adhesion.

[0063] The above description of the embodiments is to facilitate the understanding and use of the invention by those skilled in the art. It is obvious that those skilled in the art can easily make various modifications to these embodiments and apply the general principles described herein to other embodiments without creative work. Therefore, the present invention is not limited to the above embodiments, and improvements and modifications made by those skilled in the art based on the disclosure of the present invention without departing from the scope of the present invention should be within the scope of protection of the present invention.

Claims

1. A vacuum plating topcoat for automotive interior parts, characterized in that: The composition comprises the following components in parts by weight: 5-15 parts of hexafunctional polyurethane acrylate, 5-15 parts of difunctional polycarbonate modified acrylic resin, 15-30 parts of tetrafunctional polyurethane acrylate, 3-8 parts of monofunctional monomer isobornyl acrylate, 0.1-0.5 parts of trifunctional phosphate, 0.1-0.5 parts of leveling agent, 3-5 parts of photosensitizer, and 40-50 parts of solvent.

2. The vacuum plating topcoat for automobile interior decoration parts according to claim 1, characterized in that: The viscosity of the hexafunctional polyurethane acrylate at 25° C. is 30000-40000 mPa·s.

3. The vacuum plating topcoat for automobile interior decoration parts according to claim 1, characterized in that: The viscosity of the difunctional polycarbonate modified acrylic resin at 25°C is 20000-30000 mPa·s, and the molecular weight of the monofunctional isobornyl acrylate is 208, and the viscosity at 25°C is 5-15 mPa·s.

4. The vacuum plating topcoat for automobile interior decoration parts according to claim 1, characterized in that: The viscosity of the tetrafunctional polyurethane acrylate at 25° C. is 5000-8000 mPa·s.

5. The vacuum plating topcoat for automobile interior decoration parts according to claim 1, characterized in that: The trifunctional phosphate ester is Sartomer SR9051NS.

6. The vacuum plating topcoat for automobile interior decoration parts according to claim 1, characterized in that: The leveling agent is polyester-modified polydimethylsiloxane containing acrylic functional groups.

7. The vacuum plating topcoat for automobile interior decoration parts according to claim 1, characterized in that: The photosensitizers are 1-hydroxycyclohexyl phenyl ketone and 2,4,6-trimethylbenzoyl diphenyl phosphine oxide.

8. The vacuum plating topcoat for automobile interior decoration parts according to claim 1, characterized in that: The composition comprises the following components in parts by weight: 12 parts of hexafunctional polyurethane acrylate, 8 parts of difunctional polycarbonate modified acrylic resin, 25 parts of tetrafunctional polyurethane acrylate, 5 parts of monofunctional isobornyl acrylate, 0.5 parts of trifunctional phosphate, 0.3 parts of leveling agent, 3.8 parts of photosensitizer, and 45.4 parts of solvent.

9. A method for preparing a vacuum electroplating topcoat for automotive interior decoration parts according to any one of claims 1 to 8, characterized in that: The method comprises the following steps: stirring and mixing the formula components uniformly to obtain the topcoat.

10. An application of the vacuum plating topcoat for automotive interior decoration parts as claimed in any one of claims 1 to 8, characterized in that: The topcoat is used for coating surfaces or mid-coat surfaces.

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