Partially light-transmitting automobile exterior trim part and preparation method and application thereof

Abstract

The present application relates to a kind of local light-transmitting automotive exterior trim and its preparation method and application, belong to automotive exterior trim technical field.The present application discloses a kind of local light-transmitting automotive exterior trim, the back surface of the automotive exterior trim substrate is provided with back surface color paint layer, front is sequentially provided with primer layer, front color paint layer, pearl paint layer, protective paint layer, wherein part of coating of primer layer, front color paint layer, pearl paint layer is removed by laser, forms laser engraving layer, the thickness of the laser engraving layer is less than or equal to the total thickness of primer layer, front color paint layer, pearl paint layer.The present application also discloses a kind of preparation method of local light-transmitting automotive exterior trim, and the application of the local light-transmitting automotive exterior trim in car.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of automobile exterior parts, and relates to a locally light-transmitting automobile exterior part and a preparation method and application thereof. BACKGROUND

[0002] The laser engraving technology is gradually expanding its application year by year due to its advantages of permanence, anti-counterfeiting, high precision and low cost. However, the laser engraving technology is rarely used in automobile exterior parts, because the existing coating process may cause unclear coating interface and poor adhesion of each coating, resulting in delamination.

[0003] In order to solve the above problems, a laser engraving process for automobile exterior parts is disclosed in Chinese patent application (publication number: CN113857019A), in which the colored paint is removed from the surface of the semi-cured primer and colored paint by laser engraving, and transparent paint is sprayed. The primer and the color paint are semi-cured by controlling the baking temperature and time of the primer and the color paint. However, the semi-cured primer and color paint may affect the laser engraving effect and efficiency. SUMMARY

[0004] The purpose of the present application is to solve the above problems existing in the prior art, and a locally light-transmitting automobile exterior part with good adhesion is provided.

[0005] The purpose of the present application can be achieved by the following technical solutions:

[0006] A locally light-transmitting automobile exterior part, the automobile exterior part substrate back surface is provided with a back surface color paint layer, and the front surface is sequentially provided with a primer layer, a front surface color paint layer, a pearl paint layer and a protective paint layer. Part of the coating of the primer layer, the front surface color paint layer and the pearl paint layer is removed by laser to form a laser engraving layer, and the thickness of the laser engraving layer is less than or equal to the total thickness of the primer layer, the front surface color paint layer and the pearl paint layer.

[0007] Preferably, the material of the primer layer is black and / or gray laserable paint.

[0008] The present application can remove part of the coating of the primer layer, the front surface color paint layer and the pearl paint layer by laser to expose the substrate, clearly display the color of the back surface color paint layer, and the laser engraving area is multiple. When the color of the front surface color paint layer is the same as that of the back surface color paint layer, the requirement of uniform color of the vehicle body can be met. When the color of the front surface color paint layer is different from that of the back surface color paint layer, the individualized requirement of color diversification can be met.

[0009] Preferably, the preparation method of the back surface color paint layer can include one or more of film pasting, spraying and PVD.

[0010] The back surface color paint layer can also be omitted, and the transparent structure can be directly displayed.

[0011] Preferably, the primer layer, the front color paint layer, the pearl paint, and the protective paint layer are prepared by a 4C2B process.

[0012] Further preferably, the primer layer, the front color paint layer, and the protective paint layer are prepared by a 3C2B process.

[0013] Preferably, the thickness of the back color paint layer is 10-30 μm.

[0014] Preferably, the thickness of the primer layer is 20-35 μm, and the thickness of the front color paint layer is 10-20 μm.

[0015] Preferably, the light transmittance of the substrate is 70-98%.

[0016] Further preferably, the light transmittance loss rate of the substrate after covering the back color paint layer is 1-5%, i.e., the light transmittance of the laser-engraved part of the partially light-transmissive automotive exterior part is 60-97%.

[0017] Still further preferably, when the thickness of the laser-engraved layer is less than the total thickness of the primer layer, the front color paint layer, and the pearl paint layer, the light transmittance of the laser-engraved part of the partially light-transmissive automotive exterior part is 60-92%.

[0018] Preferably, the substrate is a transparent thermoplastic and / or thermosetting material, including one or more of PC, PMMA, and PP.

[0019] The present application also discloses a preparation method of a partially light-transmissive automotive exterior part, which comprises the following steps: spraying a laser-engraveable primer on the surface of a pretreated substrate by using an air spray gun to form a primer layer after first flash drying; then spraying a laser-engraveable front color paint and a pearl paint by using a first air spray gun with a high-pressure spin cup and a second air spray gun in sequence to form a front color paint layer and a pearl paint layer after second flash drying and first baking; then laser-engraving a desired pattern by using a laser-engraving process; and finally spraying a transparent protective paint layer on the surface and performing second baking.

[0020] The present application uses a first air spray gun with a high-pressure spin cup to spray the front color paint, which can increase the adhesion of the primer layer and the front color paint layer; and a second air spray gun to ensure smooth paint surface and further ensure uniformity and adhesion.

[0021] Preferably, the pretreatment of the substrate comprises water washing, water blowing, deionization treatment, and flame treatment; the flame treatment is methane flame treatment, and the surface tension is 48-55 Nm / m.

[0022] Preferably, the air speed of the air spray gun is 0.30-0.45 m / s.

[0023] Preferably, the spraying interval of the first air spray gun with a high-pressure spin cup and the second air spray gun is 85-95 s.

[0024] An interval of 85-95 seconds between two processes can increase the leveling properties of the second coat.

[0025] Further preferred, the pressure of the first high-pressure rotary cup is 0.3 to 0.5 MPa.

[0026] Preferably, the first flash drying time is 5 to 7.5 minutes, and the second flash drying time is 8 to 10 minutes.

[0027] Further preferably, the flash drying temperature is 23±2℃ and the humidity is 65±5%HR.

[0028] Preferably, the first drying temperature is 80-120℃ and the time is 40 minutes; the second drying temperature is 65-85℃ and the time is 30 minutes.

[0029] Further preferably, the second drying temperature is lower than the first drying temperature.

[0030] Preferably, the color paint is sprayed directly after the primer layer flash-drys; after the second flash-dry and the first drying, the primer layer, the top color paint layer, and the pearlescent paint layer are completely dry.

[0031] The 4C2B and / or 3C2B process of this invention can avoid the problems of unclear laser engraving interfaces and delamination caused by "wet-on-wet" or "dry-on-dry" contact between coatings.

[0032] Preferably, the laser-engraved layer area is filled with a transparent protective varnish.

[0033] This invention also discloses the application of a partially translucent automotive exterior trim in automobiles. The light source is emitted from the back of the substrate, and the pattern of the laser-engraved layer can be seen from the front of the substrate. When the light source is turned off, the color of the paint layer on the back can be seen through from the front of the substrate.

[0034] Preferably, when the partially translucent automotive exterior trim of the present invention is applied in a car, the coating on the front (outer side) can ensure good adhesion and is not easy to peel off or discolor.

[0035] Compared with the prior art, the present invention has the following beneficial effects:

[0036] 1. The partially translucent automotive exterior trim of the present invention has a laser engraving layer, which allows the front laser engraved area to be translucent when the light source is turned on, and to show the back color when the light source is not turned on.

[0037] 2. The preparation method of the present invention can ensure that the interfaces of each layer on the front side are clear, and the laser method can obtain more accurate patterns.

[0038] 3. The preparation method of the present invention meets the adhesion requirements of automotive exterior trim during application, and has good performance while maintaining aesthetics. Attached Figure Description

[0039] Figure 1 This is a schematic diagram of a partially translucent automotive exterior component in Embodiment 1 of the present invention.

[0040] 1. Substrate, 2. Back paint layer, 3. Primer layer, 4. Front paint layer, 5. Pearl paint layer, 6. Protective paint layer, 7. Laser engraving layer. Detailed Implementation

[0041] The following are specific embodiments of the present invention, which further describe the technical solution of the present invention, but the present invention is not limited to these embodiments.

[0042] Example 1

[0043] PMMA substrate 1 with 98% light transmittance was pretreated by water washing, water drying, deionization treatment and methane flame treatment to achieve a surface tension of 50 Nm / m. An air-sprayed primer was applied, forming a 25μm thick primer layer 3 after the first flash-dry. The flash-drying temperature was 23±2℃, the humidity was 65±5%HR, and the time was 6min. Then, a first coat of laser-engravable topcoat was applied using a high-pressure rotary cup (pressure 0.4Mpa), followed by a second coat of pearlescent paint using an air-sprayed gun. The spraying interval was 89s. After a second flash-dry and a first drying, a 15μm thick topcoat layer 4 and a 10μm thick pearlescent paint layer 5 were formed. The flash-drying temperature was 23±2℃, the humidity was 65±5%HR, the second flash-drying time was 9min, and the first drying temperature was 90℃ for 40min. Next, the desired pattern was laser-engraved using a laser engraving process. The laser-engraved layer 7 had no residue of the primer layer 3. Finally, a 30μm thick transparent protective varnish layer (acrylic) was applied to the surface using an electrostatic rotary cup. The second drying temperature was 70℃ for 30min. A 10μm thick back paint layer, the same color as the front paint, is sprayed onto the back of the substrate. For partially translucent automotive exterior parts, the light transmittance at the laser-engraved area is 95%.

[0044] The light source shines from the back of the substrate 1, and the pattern of the laser-engraved layer 7 can be seen from the front of the substrate. When the light source is turned off, the color of the entire partially translucent automotive exterior parts can be seen from the front of the substrate 1.

[0045] The obtained partially translucent automotive exterior parts were tested for adhesion (ISO 2409), and the result was grade 0. The cut edges were clear, the boundaries were obvious, and there were no square delaminations.

[0046] Example 2

[0047] Compared with Example 1, the difference is that the primer layer 3, the top color paint layer 4, and the pearlescent paint layer 5 are all sprayed with an air spray gun.

[0048] The obtained partially translucent automotive exterior parts were tested for adhesion (ISO 2409), and the result was grade 0. The edges had slight debris, the boundaries were obvious, and there was no grid delamination.

[0049] Example 3

[0050] Compared with Example 1, the difference is that the primer layer 3, the top color paint layer 4, and the pearlescent paint layer 5 are all applied by high-pressure rotary cup spraying.

[0051] The obtained partially translucent automotive exterior parts were tested for adhesion (ISO 2409), and the result was grade 0. The edges had slight debris, the boundaries were obvious, and there was no grid delamination.

[0052] Example 4

[0053] The difference from Example 1 is that the first flash drying is not performed.

[0054] The obtained partially translucent automotive exterior parts were tested for adhesion (ISO 2409). The result was Grade 1, with a small amount of peeling at the intersections, debris at the edges, and no grid delamination.

[0055] Example 5

[0056] The difference from Example 1 is that a second flash drying is not performed.

[0057] The obtained partially translucent automotive exterior parts were tested for adhesion (ISO 2409). The result was Grade 1. The surface of the front paint layer 4 was not completely smooth, with small parts peeling off at the intersections and no grid-like delamination.

[0058] Example 6

[0059] Compared with Example 1, the difference is that the first flash drying and the second flash drying are not performed.

[0060] The obtained partially translucent automotive exterior parts were tested for adhesion (ISO 2409), and the result was level 2. The surface of the front paint layer 4 was not completely smooth, with small parts peeling off at the intersections, and the boundary was blurred with slight delamination.

[0061] Example 7

[0062] Compared with Example 1, the difference is that the first drying temperature is the same as the second drying temperature, which is 70°C. After the first drying, the front color paint layer 4 and pearl paint layer 5 are in a semi-cured state.

[0063] The obtained partially translucent automotive exterior parts were tested for adhesion (ISO 2409). The result was Grade 1, with a small amount of peeling at the intersection, slight debris at the edges, slightly blurred boundaries, and no grid delamination.

[0064] Example 8

[0065] Compared with Example 1, the difference is that an air spray gun is used to spray a laser-engravable primer, which is then dried at 70°C to form a primer layer.

[0066] The obtained partially translucent automotive exterior parts were tested for adhesion (ISO 2409). The result was Grade 1, with a small amount of peeling at the intersection, slight debris at the edges, slightly blurred boundaries, and no grid delamination.

[0067] Example 9

[0068] Compared with Example 1, the difference is that the back paint layer 2 is applied by a film, and the different laser engraving layers 7 have different colors.

[0069] The light source shines from the back of the substrate, and the pattern of the laser-engraved area can be seen from the front of the substrate. The color of the light changes slightly with the paint layer on the back. When the light source is turned off, the color of the car exterior parts that are partially translucent can be seen from the front of the substrate.

[0070] Example 10

[0071] Compared with Example 1, the difference is that there is no back paint layer 2.

[0072] The light source shines from the back of the substrate, and the pattern of the laser-engraved area can be seen from the front of the substrate, making the light source brighter.

[0073] In summary, the partially translucent automotive exterior trim of the present invention has a laser engraving layer, which allows the front laser engraved area to be translucent when the light source is turned on, and to show the back color when the light source is not turned on; in addition, the partially translucent automotive exterior trim of the present invention has good adhesion and is not easy to peel off, which can meet the requirements of being the front (outer side).

[0074] The specific embodiments described herein are merely illustrative of the spirit of the invention. Those skilled in the art to which this invention pertains may make various modifications or additions to the described specific embodiments or use similar methods to substitute them, without departing from the spirit of the invention or exceeding the scope defined by the appended claims.

Claims

1. A partially translucent automotive exterior trim component, characterized in that, The partially translucent automotive exterior component substrate has a back paint layer on its back side and a primer layer, a front paint layer, a pearlescent paint layer, and a protective paint layer on its front side. Parts of the primer layer, the front paint layer, and the pearlescent paint layer are removed by laser to form a laser-etched layer. The thickness of the laser-etched layer is less than or equal to the total thickness of the primer layer, the front paint layer, and the pearlescent paint layer. The laser-etched layer area is filled with a transparent protective paint. The thickness of the back paint layer is 10~30μm; The light transmittance loss rate of the substrate after being covered with a back paint layer is 1-5%; The method for preparing the partially translucent automotive exterior trim includes: After pretreatment, a laser-engravable primer is sprayed onto the substrate surface using an air spray gun. After the first flash-dry, a primer layer is formed. Then, a laser-engravable front color paint and a pearlescent paint are sprayed sequentially using a first high-pressure rotary cup and a second air spray gun. After a second flash-dry and a first drying, a front color paint layer and a pearlescent paint layer are formed. Next, the desired pattern is laser-engraved using a laser engraving process. Finally, a transparent protective paint layer is sprayed onto the surface and dried a second time. The first flash drying time is 5~7.5 min, and the second flash drying time is 8~10 min; the first drying temperature is 80~120℃ and the time is 40 min; the second drying temperature is 65~85℃ and the time is 30 min. After the primer layer flash-drys, the topcoat paint is sprayed directly; after the second flash-dry and the first drying, the primer layer, the topcoat paint layer, and the pearlescent paint layer are completely dry.

2. The partially translucent automotive exterior trim component according to claim 1, characterized in that, The air spray gun wind speed is 0.30~0.45m / s; the spraying interval between the first high-pressure rotary cup and the second air spray gun is 85~95s.

3. The partially translucent automotive exterior trim component according to claim 1, characterized in that, The primer layer, topcoat layer, pearlescent coating layer, and protective coating layer are prepared using a 4C2B process.

4. The partially translucent automotive exterior trim component according to claim 1, characterized in that, The thickness of the primer layer is 20~35μm, and the thickness of the topcoat layer is 10~20μm.

5. The partially translucent automotive exterior trim component according to claim 1, characterized in that, The light transmittance of the substrate is 70-98%.

6. A method for preparing a partially translucent automotive exterior trim part as described in claim 1, characterized in that, The preparation method includes: A PMMA substrate with 98% light transmittance was pretreated by washing, water drying, deionization, and methane flame treatment to achieve a surface tension of 50 N / m. A laser-engravable primer was then applied using an air spray gun, forming a 25 μm thick primer layer after the first flash-dry. The first flash-dry temperature was 23±2℃, the humidity was 65±5% HR, and the time was 6 min. Next, a first coat of laser-engravable topcoat paint was applied using a high-pressure rotary cup spray gun, followed by a second coat of pearlescent paint applied using an air spray gun, with an 89-second interval between coats. After a second flash-dry and a first drying, a 15 μm thick topcoat was formed. The front-side paint layer and a 10μm thick pearlescent paint layer are applied. The second flash-dry temperature is 23±2℃, the humidity is 65±5%HR, the second flash-dry time is 9min, and the first drying temperature is 90℃. Then, the required pattern is laser-engraved using a laser engraving process. There is no residual primer layer after laser engraving. Finally, a 30μm thick transparent protective paint layer is sprayed onto the surface using an electrostatic rotary cup, and the second drying temperature is 70℃. A 10μm thick back paint layer of the same color as the front-side paint is sprayed onto the back of the substrate. The light transmittance of the laser-engraved area of ​​the partially translucent automotive exterior parts is 95%. The light source shines from the back of the substrate, and the pattern of the laser-engraved area can be seen from the front of the substrate. When the light source is turned off, the color of the entire partially translucent automotive exterior parts is consistent and can be seen from the front of the substrate.

7. The application of a partially translucent automotive exterior trim component as described in claim 1 in an automobile, characterized in that, The light source shines from the back of the substrate, and the pattern of the laser-engraved layer can be seen from the front of the substrate. When the light source is turned off, the color of the paint layer on the back can be seen through from the front of the substrate.

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