Metal effect pigment composition, metal effect coating containing same and application

Abstract

The invention discloses a metal effect pigment composition, a metal effect coating containing the metal effect pigment composition and application. The metal effect pigment composition comprises the following components: at least one aluminum powder pigment and pearlescent pigment, wherein the pearlescent pigment at least comprises at least one silver pearlescent pigment and at least one white pearlescent pigment; wherein the mass ratio of the pearlescent pigment to the aluminum powder pigment is (1: 0.8)-(1: 3). After the metal effect pigment composition is applied to the metal effect coating, the metal effect coating can be endowed with good radar transmittance, good covering power and appearance (including metallic feeling, brightness, flickering property, multi-angle brightness (especially small-angle brightness) effect and the like).

Description

Technical Field

[0001] The present invention relates to the technical field of metal effect coatings, and more specifically to a metal effect pigment composition, a metal effect coating containing the same, and applications thereof. Background Art

[0002] With the development of automobile technology, people have higher and higher requirements for driving experience. Radar, as a component that can provide multiple functions such as obstacle detection, collision avoidance, navigation, speed measurement, etc., has an increasingly higher proportion in the field of automobile production. With the rise of autonomous driving technology in recent years, the requirements for radar capabilities have become increasingly higher. Generally, radars with a frequency of 24GHz or 77-81GHz are installed behind the bumper or other vehicle parts. Among them, radars with a frequency of 77-81GHz have been more widely used because of their small volume, strong anti-interference ability, and policy access. And because the wavelength of the 77-81GHz band radar is in the millimeter wave band of 1-10mm, it is called millimeter wave radar. Millimeter wave radar has the characteristics of excellent penetration, anti-interference ability, and small space occupation. It can recognize targets through plastic substrates (polypropylene, polycarbonate, etc.). In the automotive field, millimeter wave radars are protected by obstructions (such as some plastic parts on cars).

[0003] However, in order to have a better vehicle appearance, these obstructions on the outer surface of the car body are generally coated with paint, such as metallic effect paint. Metallic effect paint is a paint containing flaky metal pigments (most commonly aluminum powder). It is popular with consumers because of its metallic luster, angle-dependent color effects, glitter and good weather resistance, which can provide vehicles with excellent visual appearance. In order to achieve a specific design effect, the amount of aluminum powder added to the metallic effect paint is generally 2-7wt%. Too little aluminum powder added to the paint cannot reflect the expected performance; too much addition will cause many problems in many aspects such as silver powder arrangement, spraying process and storage stability. In addition, as an electromagnetic wave, the energy of millimeter wave radar is not enough to penetrate metal media. According to the content of electrodynamics, for a good conductor such as aluminum metal, the penetration depth of millimeter wave radar is only about a few hundred nanometers. The indispensability of aluminum pigments and the need to improve radar transmittance are contradictory.

[0004] Aluminum pigment is a kind of flaky effect pigment obtained by grinding, generally with a size of 5-50um, a thickness of about hundreds of nanometers, and the outer surface generally has a variety of additives added during grinding, such as oleic acid. The aluminum pigment commonly used in automobiles is a silver dollar-shaped product with a size of 10-25um, with high brightness, delicate and strong metallic appearance, unique performance and difficult to replace. In addition, it should be pointed out that the final effect of aluminum pigment in the coating is affected by many factors, such as formula components, spraying process, storage conditions, baking conditions, coating process, raw material quality, etc. During the test, the results of the coating formula often have greater volatility, which brings certain difficulties to development.

[0005] Generally speaking, aluminum effect pigments are used in the color paint layer with a thickness of about 12-18um. In the color paint layer, this flaky pigment is arranged in parallel to form a continuous structure of flaky, multi-layered superposition. The radar frequency used for the sensor is 77-81GHz, corresponding to a wavelength of about 4mm. Although this wavelength is much larger than the size of a single metal effect pigment of about 5-40um, and theoretically will not be blocked, the densely arranged aluminum pigments form a structure similar to a multi-layer, integral aluminum film, which causes loss to the radar signal. For coatings with a low aluminum pigment content, due to the large number of gaps, they can be diffracted by radar waves and the loss is small, but for coatings with a high aluminum pigment content, there are fewer gaps and the loss is obvious. In mid-to-high-end coatings, the appearance effect is required to be high, and a correspondingly high aluminum pigment content (aluminum, color aluminum, or other metal pigments) is required, and the loss to radar waves can reach 3-5dB, which is undesirable. The simple solution of reducing the amount of aluminum pigment used will have a significant impact on multiple properties such as brightness, hiding power, and glittering effect, making it unfeasible. Summary of the invention

[0006] Based on the above problems, the object of the present invention is to provide a metallic effect pigment composition, a metallic effect coating containing the same and applications thereof. The metallic effect coating containing the metallic effect pigment composition has good radar transmittance and has an excellent metallic effect appearance when used for coating plastic parts.

[0007] In order to achieve the above object, the present invention adopts the following technical solutions:

[0008] In one aspect, the present invention provides a metallic effect pigment composition comprising the following components:

[0009] at least one aluminum pigment; and

[0010] Pearlescent pigments, comprising at least one silver pearlescent pigment and at least one white pearlescent pigment;

[0011] Wherein, the mass ratio of the pearlescent pigment to the aluminum powder pigment is 1:0.8-1:3.

[0012] Furthermore, the mass ratio of the silver pearlescent pigment to the white pearlescent pigment is 1.5:1-10:1.

[0013] Furthermore, the silver pearlescent pigment is a flake pigment containing an iron oxide or titanium iron oxide coating layer, the substrate of the flake pigment is selected from mica flakes, aluminum oxide flakes, titanium dioxide flakes or glass flakes, and the appearance of the flake pigment is silver powder.

[0014] Furthermore, the D50 of the silver pearlescent pigment is in the range of 5-50 um, and the average thickness is 100-1000 nm.

[0015] Furthermore, the white pearlescent pigment is a mica flake, a glass flake or an aluminum oxide flake that is wrapped with oxide or not wrapped with oxide.

[0016] Furthermore, the D50 of the white pearlescent pigment is in the range of 5-50 um, and the average thickness is 100-1000 nm.

[0017] Furthermore, the solid content of the aluminum powder pigment is 65%-75%, and D50 is 5-30 um.

[0018] In another aspect, the present invention provides a metallic effect coating with good radar transmittance, wherein the raw materials for forming the coating include:

[0019] Film-forming resins, and

[0020] A metallic effect pigment composition as described above.

[0021] Furthermore, the metallic effect coating is a colored paint.

[0022] Furthermore, based on weight percentage, the raw material comprises 1-7wt% of the metal effect pigment composition.

[0023] In another aspect, the present invention provides a metal effect coating with good radar transmittance, wherein the metal effect coating is prepared from the metal effect coating as described above.

[0024] Furthermore, the dry film thickness of the coating is 10-18 um.

[0025] In another aspect, the present invention provides use of the metallic effect paint as described above for forming a coating film with good radar transmittance on a plastic substrate.

[0026] Furthermore, the plastic substrate is a plastic substrate of an automobile plastic component or a plastic substrate of an intelligent device.

[0027] Furthermore, the automobile plastic component is an automobile bumper.

[0028] The beneficial effects of the present invention are as follows:

[0029] In the metallic effect pigment composition provided by the present invention, a pearlescent pigment of a specific proportion and composition is used to partially replace the aluminum powder pigment. When the composition is used in a coating (paint), the coating obtained by coating has almost the same appearance performance as the coating containing only the aluminum powder pigment, and the color difference can be controlled to ΔE<1.5, especially the small-angle brightness (15° and 25°) is very similar, and the angular heterochromaticity and scintillation performance are also excellent, so that it can be directly commercialized. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] The specific implementation modes of the present invention will be further described in detail below in conjunction with the accompanying drawings.

[0031] Figure 1 Schematic diagram showing millimeter-wave lidar penetrating plastic substrates and coatings.

[0032] Figure 2 An SEM image of a cross section of the coating in Example 3 is shown. DETAILED DESCRIPTION

[0033] In order to more clearly illustrate the present invention, the present invention is further described below in conjunction with preferred embodiments and accompanying drawings. Similar components in the accompanying drawings are represented by the same reference numerals. It should be understood by those skilled in the art that the content specifically described below is illustrative rather than restrictive, and should not be used to limit the scope of protection of the present invention.

[0034] The metal effect paint commonly used in automobiles generally contains about 1-6wt% aluminum powder. The higher the aluminum powder content in the paint, the closer the aluminum powder in the coating is to forming a dense continuous structure of flakes, and multiple layers are superimposed, which leads to greater loss when radar millimeter waves penetrate such a coating.

[0035] Some of the publicly available radar-compatible coatings with metallic effects either have high radar transmittance but poor performance in terms of hiding power, color difference or small-angle brightness on the substrate; or have good coating effects on the substrate but excessive radar loss.

[0036] For the coating of plastic parts (e.g., plastic parts for automobiles, such as automobile bumpers, etc.) used to shield millimeter-wave radars, in order to achieve a good balance between good radar transmittance and excellent metallic effect of plastic parts coating, and to achieve a truly commercially viable technical solution for perfect replacement of aluminum powder pigments, a specific embodiment of the present invention provides a metallic effect pigment composition, comprising the following components:

[0037] at least one aluminum pigment; and

[0038] Pearlescent pigments, comprising at least one silver pearlescent pigment and at least one white pearlescent pigment;

[0039] Wherein, the mass ratio of the pearlescent pigment to the aluminum powder pigment is 1:0.8-1:3.

[0040] In the metal effect pigment composition, silver pearlescent pigment and white pearlescent pigment are selected as pearlescent pigments, and the pearlescent pigment is mixed with aluminum powder pigment in a certain mass ratio, so that after the metal effect pigment composition is used in the metal effect coating, the metal effect coating can be endowed with good radar transmittance, good hiding power and appearance (including metallic feel, brightness, glitter, multi-angle brightness (especially small-angle brightness) effects, etc.).

[0041] Pearlescent pigments have similar angle-dependent color, high brightness and glittering effects as aluminum pigments, but their hiding power is significantly lower. Using a combination of multiple pearlescent pigments can improve brightness at multiple angles. However, for coating systems based on aluminum pigments, adding more pearlescent pigments may affect the arrangement of aluminum pigments and pearlescent pigments, causing low brightness and changes in glittering.

[0042] In some preferred examples, the mass ratio of the pearlescent pigment to the aluminum powder pigment includes but is not limited to 1:1-1:3. In this case, the above-mentioned effect is better. In some specific examples, the mass ratio of the pearlescent pigment to the aluminum powder pigment includes but is not limited to 1:1-1:2.5, 1:1-3:7, 1:1, 3:7, etc.

[0043] In this embodiment, suitable aluminum powder pigments can be selected from pigments commonly used in automotive metal effect coatings, and no further requirements are made here. The preferred aluminum powder pigment refers to a flaky aluminum pigment prepared by grinding spherical aluminum powder as a raw material, showing a silver metallic appearance. According to actual production needs, one or more aluminum powder pigments can be selected. The aluminum powder pigment has a structure of silver dollar shape, corn flake shape and other suitable shapes. Suitable aluminum powder pigments have a solid content of 65%-75%, and D50 of 5-30um, preferably 5-25um, and more preferably 9-15um, which helps to obtain a coating with a more delicate and bright metallic effect, or 16-25um, which helps to obtain a coating with a metallic effect with a strong sense of glitter.

[0044] Exemplary aluminum powder pigments include, but are not limited to, 4660NS (D50 is 9 um), 6220NS (D50 is 18 um) and the like selected from Toyo Aluminum. It should be noted that the results show that the use of aluminum powder from other suppliers will not affect the technical effects of the present invention.

[0045] It can be understood that, in this embodiment, the pearlescent pigment includes one or more silver pearlescent pigments and one or more white pearlescent pigments.

[0046] In this embodiment, the exemplary silver pearlescent pigment refers to a flake pigment containing an iron oxide or titanium iron oxide coating layer. The substrate of the flake pigment may be mica flakes, aluminum oxide flakes, titanium dioxide flakes, glass flakes, etc. containing or not containing titanium oxide, and the appearance of the flake pigment is silver powder.

[0047] In this embodiment, the silver pearlescent pigment has high hiding power, wherein high hiding power means that when the silver pearlescent pigment is used in an amount of 5 wt % and the spraying thickness is 15 um, the hiding power of the obtained coating on black and white grid paper is less than 50 um, more preferably less than 30 um.

[0048] In some examples, the silver pearlescent pigment has a D50 range of 5-50 um and an average thickness of 100-1000 nm.

[0049] In some preferred examples, the D50 of the silver pearlescent pigment is preferably 5-40 um. By controlling the D50 of the silver pearlescent pigment, different brightness, hiding power and angle-dependent color effects can be achieved, which depends on product requirements.

[0050] Exemplary silver pearlescent pigments include, but are not limited to, 9602, 9605, and 9612 from Merck's iriodin series, or T61-10WNT microsilver from Merck's xirallic series, or OEM opaque silver series from Aika.

[0051] In this embodiment, the white pearlescent pigment may be a mica sheet, a glass sheet, an aluminum oxide sheet or the like which may be coated with oxide or not coated with oxide.

[0052] In this embodiment, the white pearlescent pigment may not have a metallic appearance. In some examples, the white pearlescent pigment has a D50 range of 5-50 um and an average thickness of 100-1000 nm.

[0053] In some preferred examples, the D50 of the white pearlescent pigment is preferably 5-40 um. By controlling the D50 of the white pearlescent pigment, different brightness, hiding power and angle-dependent color effects can be achieved, which depends on product requirements.

[0054] Exemplary white pearlescent pigments include, but are not limited to, 9121 or 9119 selected from Merck's iriodin series, T60-10WNT crystal silver (ie, Xirallic T61-10) from Merck's xirallic series, and OEMsilver series from Aika Company.

[0055] During the research, we found that the mass ratio of the silver pearlescent pigment to the white pearlescent pigment in the pearlescent pigment affects the hiding power, multi-angle brightness and glitter of the obtained coating. In some examples, the mass ratio of the silver pearlescent pigment to the white pearlescent pigment is 1.5:1-10:1. In some preferred examples, the mass ratio of the silver pearlescent pigment to the white pearlescent pigment includes but is not limited to 2:1-10:1, 2:1-5:1, 2:1-4:1, 2:1, 4:1, etc., and the above effects are better at this time.

[0056] According to another specific embodiment of the present invention, there is provided a metallic effect coating with good radar transmittance, wherein the raw materials for forming the coating include:

[0057] Film-forming resins, and

[0058] A metallic effect pigment composition as described above.

[0059] In this embodiment, the metallic effect paint is an oily paint, and the metallic effect paint can be used as a color paint. The metallic effect paint is preferably used in the coating of automobile plastic parts. The metallic effect paint applied on automobile plastic parts can not only provide excellent hiding power and good appearance (including metallic feeling, brightness, glitter, multi-angle brightness (especially small-angle brightness) effects, etc.), but also has good radar transmittance, and can be directly used commercially.

[0060] Exemplarily, the automobile plastic parts include but are not limited to bumpers, etc. The automobile plastic parts are preferably plastic parts used to shield millimeter wave radars.

[0061] Exemplarily, the material of the automobile plastic parts includes but is not limited to PP, ABS, PC, etc.

[0062] For example, the film-forming resin in this embodiment may be acrylate, acrylic resin, or the like.

[0063] It is understood that the raw materials for forming the metallic effect coating may further include an organic solvent (such as butyl acetate), and other additives such as a thickener, a rheological additive, etc. may be added according to actual needs.

[0064] In some examples, the raw material contains 1-7 wt% of the metallic effect pigment composition by weight percentage. The metallic effect pigment added in this amount can give the metallic effect coating an appearance and hiding power that is equal to or better than that of a metallic effect pigment containing only pure aluminum powder pigment, and has better radar transmittance.

[0065] The metal effect coating in this embodiment can be prepared by mixing various components.

[0066] For example, in some preparation methods, the metal effect coating is dispersed and then added to a raw material containing a film-forming resin, and mixed to obtain the metal effect coating.

[0067] It should be noted that, in the metallic effect coating in this embodiment, except for the pigment selected from the metallic effect pigment composition in this embodiment, the remaining components, such as film-forming resin, solvent, other additives, etc., can be conventionally selected and added in conventional metallic effect coatings.

[0068] According to another specific embodiment of the present invention, a metal effect coating with good radar transmittance is provided. The metal effect coating is prepared from the metal effect coating as described above.

[0069] Specifically, the metal effect coating is obtained by applying the metal effect paint on a substrate and then curing it. A suitable application method is spraying, which can better arrange the flake pigments on the substrate.

[0070] Exemplarily, the dry film thickness of the coating is 10-18 um.

[0071] It can be understood that, because the metal effect coating is prepared from the metal effect pigment, the metal effect coating has the effect brought by the metal effect pigment, which will not be described in detail here.

[0072] According to another specific embodiment of the present invention, there is provided use of the above-mentioned metallic effect coating for forming a coating film with good radar transmittance on a plastic substrate.

[0073] It can be understood that the coating film formed here can be the metal effect coating as described above.

[0074] Exemplarily, the metal effect paint is applied on a plastic substrate and cured to form a film to obtain the paint film.

[0075] Exemplarily, the method for forming a coating film with good radar transmittance on the plastic substrate comprises the following steps:

[0076] The primer, the metal effect paint, the topcoat and / or the clearcoat are sprayed sequentially on the plastic substrate and baked to obtain the product.

[0077] In some specific examples, the baking temperature is 60-80° C. and the baking time is 20-30 minutes.

[0078] Exemplarily, the effect of the millimeter wave radar on the coating film is shown as follows: Figure 1 As shown. Among them, Figure 1 In Basecoat, the black oval is aluminum pigment and the white oval is pearlescent pigment. Figure 1It can be seen that after the millimeter wave passes through the substrate, primer, color paint and varnish in sequence, the radar transmission obtains very little loss.

[0079] In some examples, the plastic substrate is a plastic substrate of an automobile plastic part or a plastic substrate of a smart device.

[0080] In some examples, the automobile plastic parts or plastic substrates include but are not limited to bumpers, etc., and their materials include but are not limited to PP, ABS, PC, etc. The automobile plastic parts are preferably plastic parts used to shield millimeter wave radars.

[0081] The technical solution of the present invention is described below in conjunction with some specific embodiments:

[0082] The raw materials involved in the specific embodiments of the present invention are described as follows:

[0083] The aluminum powder pigments are 4660NS (D50 is 9 um) and 6220NS (D50 is 18 um) from Toyo Aluminum. It should be noted that the results show that the use of aluminum powder from other suppliers will not affect the technical effect of the present invention.

[0084] Pearlescent pigments:

[0085] The silver pearlescent pigment is selected from: 9602, 9605, 9612 of Merck's iriodin series, or T61-10WNT microsilver of Merck's xirallic series, OEM opaque silver series (superfine, fine, medium) with silver appearance of Aika Company, etc.

[0086] The white pearlescent pigment is selected from: 9121 or 9119 of Merck's iriodin series, T60-10WNT crystalsilver of Merck's xirallic series, OEM silver series (superfine, fine, medium) with white appearance of Aika Company, etc.

[0087] Of course, the pearlescent pigments available are not limited to the above suppliers.

[0088] Coating system: solvent-based base materials for plastic parts from Nippon Paint, including pin600 intense color base material and pin 600 light color base material, are used. The formulas of pin600 intense color base material and pin600 light color base material are shown in Table 1 and Table 2, respectively.

[0089] The raw material ratio of the pin600 rich color base material is:

[0090] Table 1

[0091] Product Name Weight DISPARLON 6900-20X 45 Xylene 6 Butyl acetate 5 CAB531-1 20% butyl acetate solution 15 Isobutanol 9 Acrylic resin: SETALUX XCS1518 20

[0092] The raw material ratio of the pin600 light color base material is:

[0093] Table 2

[0094] Product Name Weight DISPARLON 4200-20 25 Xylene 21 Ethyl acetate 8 CAB531-1 20% butyl acetate solution 21 Isobutanol 25

[0095] The solvent used is butyl acetate, an organic solvent commonly used in coatings. Other solvents such as xylene can also be used.

[0096] Comparative Example 1-Comparative Example 5

[0097] Comparative Examples 1 to 5 provide a coating, the raw material composition of the coating is shown in Table 3 below.

[0098] The preparation of the coating comprises the following steps:

[0099] The aluminum powder pigment is dispersed by an organic solvent and then mixed with the base material to obtain the coating.

[0100] Table 3

[0101]

[0102] Table 3 above is a comparative ratio of different addition amounts of aluminum powder pigments of two models, 4660NS and 6220NS, in order to clearly draw the influence of different addition amounts of aluminum powder pigments on the technical effect and further confirm the significant improvement effect brought about by the addition of pigments.

[0103] Comparative Example 6-Comparative Example 9

[0104] Comparative Examples 6 to 9 provide a coating, the raw material composition of the coating is shown in Table 4 below.

[0105] The preparation of the coating comprises the following steps:

[0106] The aluminum powder pigment and the pearlescent pigment are dispersed by an organic solvent and then mixed with the base material to obtain the coating.

[0107] Table 4

[0108]

[0109] Table 4 above is a comparative example of the substitution effect of adding silver or white pearlescent pigment alone on the basis of adding aluminum powder pigment, the purpose of which is to verify the advantages of the metal pigment composition scheme of the present invention.

[0110] Example 1-Example 6

[0111] A metallic effect coating with good radar transmittance, the raw material composition of the coating is shown in Table 5 below.

[0112] The preparation of the coating comprises the following steps:

[0113] The aluminum powder pigment and the pearlescent pigment are dispersed by an organic solvent and then mixed with the base material to obtain the coating.

[0114] Table 5

[0115]

[0116]

[0117] The above-mentioned metallic effect coatings are applied in the following ways:

[0118] Flex 700 primer (a product of Nippon Paint), the metal effect coating of the embodiment of the present invention or the comparative example, and Flex200 (a product of Nippon Paint) were sprayed (ecogun machine spraying) on ​​a 3 mm thick PP plate (length and width 150*200 mm) in sequence, with the thickness shown in Table 6 below, and then placed flat in an oven and baked at 80°C for 30 min, and then the following index tests were performed.

[0119] Table 6

[0120] coating Dry film thickness / um FLEX700 10um Example or comparative example coating 15um FLEX200 35um

[0121] Performance Testing:

[0122] The optical indicators are tested using BYK-MAC tester;

[0123] Radar penetration loss is tested using Rohde & Schwarz QAR equipment.

[0124] Some properties of the above-mentioned metal effect coatings after coating are shown in Table 7 below.

[0125] Table 7

[0126]

[0127]

[0128] Among them, in Table 7, regarding performance ΔE, where:

[0129] Benchmark 1 refers to the E value in Comparative Example 1 as a benchmark. When the aluminum powder pigment in the formula of other embodiments or comparative examples is 4660NS, the absolute value of the difference between the E value of the coating obtained by coating the coating film of these embodiments or comparative examples and the E value in Comparative Example 1 is the ΔE value corresponding to the embodiment or comparative example;

[0130] Benchmark 2 refers to the E value in Comparative Example 4 as a benchmark. When the aluminum pigment in the formula of other embodiments or comparative examples is 6220NS, the absolute value of the difference between the E value of the coating obtained by coating the paint film of these embodiments or comparative examples and the E value in Comparative Example 4 is the ΔE value corresponding to the embodiment or comparative example.

[0131] It can be seen from Table 7 above that:

[0132] 1) Comparative Examples 1-5 show that as the amount of silver powder used is continuously reduced, multiple indicators of the metallic effect coating change, which are manifested as an increase or decrease in brightness at small angles (L15°) and medium angles (L45°), a larger color difference (△E), an increase in the dynamic index (FI) and a decrease in hiding power;

[0133] 2) Comparative Examples 6-9 show that the use of a single pearlescent pigment can reduce color difference and improve brightness (L) to a certain extent, but the dynamic index will be significantly affected, and the glitter (G) and hiding power will not change much compared with the same amount of silver powder;

[0134] 3) Examples 1-2 show that, surprisingly, for the replacement of about 30 wt% of the pearlescent composition, all indicators are very close to those of pure aluminum powder pigment, showing very small small-angle brightness deviation, low color difference, and almost consistent dynamic index, scintillation, etc., with only a slight decrease in hiding power, because the hiding power of the pearlescent pigment cannot achieve the effect of aluminum powder;

[0135] 4) Examples 3-4 show that for the replacement of 50wt% of the pearlescent composition, the deviation of various indicators is slightly greater than that of the replacement of 30wt%, which is understandable, but still better than simply reducing the amount of silver powder by 50wt%; it should be pointed out that the silver pearlescent pigment and the white pearlescent pigment show a certain synergy, and the addition of the white pearlescent pigment can improve the brightness of the coating, etc.;

[0136] 5) Examples 5-6 show that for the replacement of large-particle aluminum powder pigment (18um), the effect of the pearlescent composition of the above examples is slightly lower than that of the composition of smaller-particle aluminum powder pigment (9um). This is because its angular heterochromaticity is too strong. The same good replacement effect can be achieved by adjusting the type of pearlescent pigment in a targeted manner. The embodiments of the present invention only demonstrate the effectiveness of the technical solution and no longer list replacement solutions for each type of aluminum powder. Generally speaking, when the aluminum powder pigment D50 is 9-15um, a delicate and bright metallic effect can be achieved. When the particle size is larger (16-25um), the glittering effect is strong, and each has its own application advantages. The excellent replacement effect of the above examples for small particle sizes shows its application advantages in automotive scenes.

[0137] 6) The test results of radar loss show that reducing the amount of silver powder will reduce the radar loss accordingly, which is in line with theoretical expectations. In addition, compared with the data of simply reducing the amount of silver powder and adding alternative pearlescent pigments, it can be seen that pearlescent pigments have no effect on the loss. The table shows that when 30% of pearlescent pigments replace silver powder, the transmission loss can be reduced by 38.9%, and when 50% of pearlescent pigments replace silver powder, the transmission loss can be reduced by 63.9%. On the one hand, the pearlescent pigment with a lower dielectric constant replaces the conductive aluminum pigment, and on the other hand, the addition of pearlescent pigments increases the gap between aluminum pigments and enhances the transmission and diffraction capability of millimeter-wave radar.

[0138] The gloss and distinctness of image of the representative coatings of Example 1 and Example 3 were tested, and the test results are shown in Table 8. The results in Table 8 show that the replacement of pearlescent pigments will not affect the gloss and distinctness of image indexes of the coatings (only for comparison and explanation of the effect of pearlescent pigments, and the size of specific indexes can be adjusted accordingly according to the formulation, process and specification requirements), while the cross-sectional SEM image of Example 3 (as shown in Table 8) Figure 2 ) also shows that the silver powder / pearlescent composition mixed pigment is well arranged, and the presence of the pearlescent composition does not cause changes in the silver powder arrangement.

[0139] Table 8

[0140]

[0141] Obviously, the above embodiments of the present invention are merely examples for clearly illustrating the present invention, and are not limitations on the implementation methods of the present invention. For ordinary technicians in the relevant field, other different forms of changes or modifications can be made based on the above description. It is impossible to list all the implementation methods here. All obvious changes or modifications derived from the technical solution of the present invention are still within the protection scope of the present invention.

Claims

1. A metallic effect pigment composition, characterized in that: Contains the following components: at least one aluminum pigment; and Pearlescent pigments, comprising at least one silver pearlescent pigment and at least one white pearlescent pigment; Wherein, the mass ratio of the pearlescent pigment to the aluminum powder pigment is 1:0.8-1:

3.

2. The metallic effect pigment composition according to claim 1, characterized in that The mass ratio of the silver pearlescent pigment to the white pearlescent pigment is 1.5:1-10:1; Preferably, the silver pearlescent pigment is a flake pigment containing an iron oxide or titanium iron oxide coating layer, the substrate of the flake pigment is selected from mica flakes, aluminum oxide flakes, titanium dioxide flakes or glass flakes, and the appearance of the flake pigment is silver powder; Preferably, the silver pearlescent pigment has a D50 range of 5-50um and an average thickness of 100-1000nm; Preferably, the white pearlescent pigment is a mica flake, a glass flake or an aluminum oxide flake that is wrapped with or not wrapped with an oxide; Preferably, the white pearlescent pigment has a D50 range of 5-50 um and an average thickness of 100-1000 nm.

3. The metallic effect pigment composition according to claim 1, characterized in that The aluminum powder pigment has a solid content of 65%-75% and a D50 of 5-30 um.

4. A metallic effect coating with good radar transmittance, characterized in that: The raw materials for forming the coating include: Film-forming resins, and The metallic effect pigment composition according to any one of claims 1 to 3.

5. The metallic effect paint according to claim 4, characterized in that: Calculated by weight percentage, the raw material contains 1-7wt% of the metal effect pigment composition.

6. A metal effect coating with good radar transmittance, characterized in that: The method is prepared from the metallic effect coating according to claim 4 or 5.

7. The metallic effect coating according to claim 6, characterized in that The dry film thickness of the coating is 10-18 um.

8. Use of the metallic effect paint according to claim 4 or 5 for forming a coating film with good radar transmittance on a plastic substrate.

9. The use according to claim 8, characterized in that The plastic substrate is a plastic substrate of an automobile plastic component or a plastic substrate of an intelligent device.

10. The use according to claim 9, characterized in that The automobile plastic component is an automobile bumper.

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