Metal effect colored paint, use thereof and method for improving brightness of metal effect colored paint

Abstract

Disclosed in the present invention are a metal effect colored paint, the use thereof and a method for improving the brightness of the metal effect colored paint. The effect of improving the brightness of a paint film is achieved by adding an inorganic sheet material during a blending process of the metal effect colored paint, wherein the inorganic sheet material is a sheet base material, the surface of which does not contain a coating layer and does not present an optical color, and the inorganic sheet material accounts for 0.3-3 wt% of the total mass of the metal effect colored paint. In the present invention, the introduction of the inorganic sheet material can solve the problem of low brightness of a paint film caused by a limited amount of an aluminum pigment, and the introduction of the inorganic sheet material does not influence indexes, e.g., the radar wave transmittance, angle-dependent heterochromatic characteristic, flickering property, glossiness and distinctness of image, of the paint film.

Description

Metallic effect color paint, its application and method for improving brightness of metallic effect color paint TECHNICAL FIELD

[0001] The present application relates to the field of coating technology. More particularly, it relates to metallic effect color paint, its application and method for improving brightness of metallic effect color paint. BACKGROUND

[0002] Metallic effect paint is a kind of paint added with flaky metal pigments to present special metallic feeling. The most commonly used metal pigment is aluminum pigment (pure aluminum pigment or modified aluminum pigment coated with a functional layer on the surface of aluminum), in addition to copper pigment, zinc pigment, etc. Metal pigment has special luster, scintillation and goniochromatic effect, and has higher brightness than general pigments due to the strong reflectivity of metal flakes to electromagnetic waves. The addition of metal pigments in paint significantly increases the diversity of color design and the depth and breadth of color. Currently, young users have higher and higher requirements for the color value of cars. The design of the color paint layer of the car determines the appearance effect.

[0003] In automotive coatings, the addition of aluminum pigment is particularly common to provide delicate metallic feeling, silver effect, scintillation, goniochromatic effect or multiple changes in color depth. It is used in an increasing number of product systems, generally adding 2-6% of aluminum pigment to present rich color effects. Aluminum pigments are arranged in order in the coating, and the flaky structure is fixed in a planar manner. When light shines on its surface, its reflectivity will change with the angle. Generally speaking, small-angle brightness (such as L15° and L25°) is greatly affected by the arrangement of silver powder (caused by specular reflection), while large-angle brightness (such as b110°) is greatly affected by the composition of the system (caused by diffuse reflection).

[0004] For aluminum pigment, a flaky effect pigment, brightness is its core indicator. The common methods for adjusting the brightness of metallic effect paint are mainly two categories: one method is to adjust the spraying process parameters, such as film thickness, drying speed, solvent type, etc.; the other method is formula design, i.e. improving the brightness of the paint by changing the type of aluminum flakes, adding directional additives, pearl powder, etc. Directional additives such as cellulose acetate butyrate, polyamide wax, etc. can significantly adjust the thixotropy of the paint, thereby assisting the ordered arrangement of metal flakes before the coating dries, obtaining good aluminum powder arrangement effect, achieving excellent goniochromaticity, while pearl powder has a multi-layer wrapped structure with different refractive indexes, making it have goniochromaticity and brightness improvement.

[0005] For some scenarios, the amount of aluminum pigment can be adjusted freely within a suitable range according to the needs to obtain high brightness. However, for specific product systems and use scenarios, it is sometimes unsatisfactory, for example, in the case of spray process parameters that are not convenient to adjust at will, or the adjustment of the composition of the formula system will face more complex changes in influence. Further, in some specific scenarios, the amount of aluminum pigment must be limited within a certain range, for example, in the case of radar penetration requirements for coatings, the coating of the automobile bumper must meet the requirements of radar wave penetration, and at the usual amount (2-6wt%), it will have a certain negative impact on radar penetration, but if the amount of aluminum pigment is increased, the radar wave may not be able to penetrate the coating, and the automobile cannot identify the target, and if a certain amount of pearl powder is added to increase the brightness, the color will change.

[0006] SUMMARY

[0007] In view of the deficiencies of the prior art, the first object of the present application is to provide a method for improving the brightness of metallic effect paint. The mixed system of inorganic sheet material and aluminum pigment is used in the preparation of metallic effect paint, and under the condition of the same total amount, the appearance of the paint film obtained is comparable to that of pure aluminum pigment or the mixed system of aluminum pigment and pearl component, while ensuring the radar penetration rate of the automobile and the color of the paint film does not change.

[0008] The second object of the present application is to provide a metallic effect paint obtained based on the method described above.

[0009] The third object of the present application is to provide the use of the metallic effect paint described above in the preparation of low automobile radar shielding coating.

[0010] The fourth object of the present application is to provide the use of the metallic effect paint described above for forming a radar wave transparent coating on a plastic substrate.

[0011] To achieve the first object described above, the present application adopts the following technical solution:

[0012] The present application discloses a method for improving the brightness of metallic effect paint, wherein an inorganic sheet material is added during the preparation of the metallic effect paint to improve the brightness of the formed paint film.

[0013] The inorganic sheet material is a sheet-shaped base material without a coating layer on the surface and without optical color, and accounts for 0.3-3wt% of the total mass of the metallic effect paint.

[0014] Further, the inorganic sheet material is selected from one or more of synthetic mica sheet, natural mica sheet, aluminum oxide sheet, titanium dioxide sheet, and glass sheet treated with silane coupling agent.

[0015] Further, the inorganic flaky material has a D50 ranging from 5 to 50 pm and an average thickness ranging from 100 to 1000 nm, and a transparency of >80%.

[0016] Further, the inorganic flaky material is selected from the synthetic mica flake SM series of Kuncai Technology and / or the nanoflake series of Glass Flake.

[0017] Further, the raw materials of the metallic effect paint further comprise at least the following two raw material components:

[0018] an oily paint base or a water-based paint base; and

[0019] an aluminum pigment;

[0020] The aluminum pigment accounts for 1-5 wt% of the total mass of the metallic effect paint.

[0021] Further, the mass ratio of the inorganic flaky material and the aluminum pigment is 0.3-1.0.

[0022] Further, the aluminum pigment has a D50 ranging from 5 to 30 pm and a solid content of 65-75%.

[0023] Further, the aluminum pigment is selected from 4660NS of Toyo Aluminum.

[0024] Further, the oily paint base is selected from the Pin600 series of Riwba.

[0025] The water-based paint base is selected from the Sun Silver BASE and Sun Silver Semi of Riwba.

[0026] Further, when the metallic effect paint is prepared using the oily paint base, the method is specifically:

[0027] The inorganic flaky material, the aluminum pigment, and the solvent are added to a mixing tank and stirred at a low speed until mixed uniformly, and then added to the oily paint base.

[0028] When the metallic effect paint is prepared using the water-based paint base, the method is specifically:

[0029] The inorganic flaky material, the aluminum pigment, and part of the water-based paint base are added to a mixing tank and stirred at a low speed until mixed uniformly, and then added to the water-based paint base.

[0030] To achieve the above-mentioned second object, the application adopts the following technical solutions:

[0031] The application discloses a metallic effect paint obtained based on the method.

[0032] To achieve the above-mentioned third object, the present application adopts the following technical solution:

[0033] The present application discloses an application of the metallic effect color paint in preparing a low automobile radar shielding coating.

[0034] To achieve the above-mentioned fourth object, the present application adopts the following technical solution:

[0035] The present application discloses an application of the metallic effect color paint in preparing a low automobile radar shielding coating.

[0036] The present application has the following beneficial effects:

[0037] The present application provides a method for improving the brightness of metallic effect color paint, wherein a certain amount of inorganic flaky material is added in the formula of the metallic effect color paint, so as to ensure the high-brightness paint film appearance and automobile radar transmittance in the application scenario where the amount of aluminum pigment is relatively limited. The selected inorganic flaky material is a single-layer flaky substance without a coating layer on the surface, high transparency and uniform refractive index, which is usually used as a pearl powder of various specifications in the field of automobile coatings, and does not have a significant optical color, so that the addition of the inorganic flaky material into the color paint formula will not affect the color of the paint film.

[0038] The technical solution of the present application is suitable for both oil-based color paint system and water-based color paint system, and compared with pure aluminum pigment or aluminum pigment and pearl component mixed system, the mixed system of inorganic flaky material and aluminum pigment will not cause color deviation of the paint film (especially b15° and b110°), will not affect the goniochromaticity and scintillation of the aluminum pigment in the metallic effect color paint, and will not affect the glossiness and fresh reflection indexes of the paint film. DETAILED DESCRIPTION

[0039] In order to more clearly illustrate the present application, the present application will be further described below in combination with preferred embodiments. It should be understood by those skilled in the art that the specific description below is illustrative rather than limiting, and should not limit the protection scope of the present application.

[0040] It should be noted that the inorganic flaky material in the present technical solution refers to a single-layer flaky material commonly used for processing pearl powder in the field of automobile coatings, without a coating layer on the surface, high transparency and uniform refractive index, such as natural mica or synthetic mica coated with a high-refractive oxide layer such as iron-titanium oxide to obtain natural mica type pearl powder or synthetic mica type pearl powder. The aluminum pigment in the present technical solution is called differently according to different regions, such as aluminum paste, aluminum silver paste, aluminum powder, silver powder, silver paste or silver paste, with a solid content usually above 65%, which can produce a metallic effect different from other ordinary pigments as a metallic pigment.

[0041] In view of the high requirements of the current society on the radar recognition of the automobile and the high requirements of the user on the high-level optical appearance of the automobile, and considering that the aluminum pigment with extremely high electrical conductivity can cause the attenuation of electromagnetic waves and reduce the radar wave transmittance, but the excellent metal effect thereof cannot be completely replaced by other materials at present, based on this, the application provides a method for improving the brightness of metal effect paint, and inorganic flaky materials without coating layers and without optical colors are used to enhance the brightness of the paint film under the condition that the amount of aluminum pigment is limited, and the transmittance of the paint film to the radar wave and the color of the paint film are not changed.

[0042] The first aspect of the application provides a method for improving the brightness of metal effect paint, in which inorganic flaky materials are added during the preparation of the metal effect paint to improve the brightness of the formed paint film, that is, the metal effect paint provided by the application at least contains the following three raw material components: an oily paint base or a water-based paint base; inorganic flaky materials; and aluminum pigment. It should be noted that the pearl component (such as pearl powder or pearl pigment) is not within the scope of the raw materials used in the application.

[0043] Further, the inorganic flaky material is a flaky matrix material without a coating layer on the surface and without optical color, and accounts for 0.3-3wt% of the total mass of the metal effect paint, for example, the inorganic flaky material accounts for 0.3wt%, 0.4wt%, 0.5wt%, 0.6wt%, 0.7wt%, 0.8wt%, 0.9wt%, 1wt%, 1.1wt%, 1.2wt%, 1.3wt%, 1.4wt%, 1.5wt%, 1.6wt%, 1.7wt%, 1.8wt%, 1.9wt%, 2wt%, 2.1wt%, 2.2wt%, 2.3wt%, 2.4wt%, 2.5wt%, 2.6wt%, 2.7wt%, 2.8wt%, 2.9wt% or 3wt% of the total mass of the metal effect paint, etc.

[0044] In the development process of the technical solution, initially, pearl powder or pearl pigment is tried to be added to the paint to obtain higher brightness of the paint film, but subsequent research finds that the pearl component can reach the brightness of the paint film comparable to or higher than that of the same amount of aluminum pigment at individual test angles, but at most conventional test angles, the brightness thereof is lower than that of the aluminum pigment, and the brightness is reduced to different degrees, and more seriously, obvious color deviation is caused. However, the single-layer inorganic flaky material without a coating layer and with uniform refractive index has unique advantages in solving the problem, that is, the inorganic flaky material has no obvious optical color, and adding the inorganic flaky material to the paint does not cause obvious color deviation, and the inorganic flaky material is the base material for making pearl powder and has similar chemical components, and has the same stability and weather resistance as the pearl powder.

[0045] Further, the inorganic flaky material is selected from one or more of synthetic mica flake, natural mica flake, alumina flake, titanium dioxide flake, and glass flake treated with silane coupling agent, and further, the D50 of the inorganic flaky material ranges from 5 to 50 μm, which is consistent with the size range of most pearl powder, and the average thickness is 100-1000 nm, and the transparency is >80%. In addition, when glass flake is selected, since the dispersibility of glass flake in the paint is relatively poor, it is necessary to select the glass flake treated with the corresponding silane coupling agent from the supplier according to the type of color paint (oil-based system or water-based system) to increase its dispersibility in the paint.

[0046] Further, the inorganic flaky material is selected from one or more of synthetic mica flake, natural mica flake, alumina flake, titanium dioxide flake, and glass flake treated with silane coupling agent, and further, the D50 of the inorganic flaky material ranges from 5 to 50 μm, which is consistent with the size range of most pearl powder, and the average thickness is 100-1000 nm, and the transparency is >80%. In addition, when glass flake is selected, since the dispersibility of glass flake in the paint is relatively poor, it is necessary to select the glass flake treated with the corresponding silane coupling agent from the supplier according to the type of color paint (oil-based system or water-based system) to increase its dispersibility in the paint.

[0047] Further, the aluminum pigment accounts for 1-5 wt% of the total mass of the metallic effect color paint; for example, the aluminum pigment accounts for 1 wt%, 1.5 wt%, 2 wt%, 2.5 wt%, 3 wt%, 3.5 wt%, 4 wt%, 4.5 wt%, or 5 wt% of the total mass of the metallic effect color paint, etc.

[0048] In one specific embodiment, the aluminum pigment selected is a representative product used in automotive coatings, which is 4660NS (D50 is 9 μm) of Toyo Aluminum, and has very high brightness and delicate metallic feeling. It should be noted that the use of aluminum pigments from other suppliers will not affect the technical effects of the present application.

[0049] Further, the mass ratio of the inorganic flaky material and the aluminum pigment is 0.3-1, and below the ratio of 0.3, the amount of inorganic flaky material added is insufficient, and the effect on brightness is limited, and above the ratio of 1, too much inorganic flaky material is stacked, which adversely affects the brightness at small and medium angles, and affects the metallic feeling of the coating; for example, the mass ratio of the inorganic flaky material and the aluminum pigment can be 0.3:1, 0.4:1, 0.5:1, 0.6:1, 0.7:1, 0.8:1, 0.9:1, 1:1, etc.

[0050] In one embodiment, the representative oil-based paint base (e.g. pin600 series, self-made by PPG) is used as an example to test the influence of the inorganic flaky material in the oil-based system, and the representative water-based paint base (e.g. Sun Silver BASE / Sun Silver half product, self-made by PPG) is used as an example to test the influence of the inorganic flaky material in the water-based system, and other oil-based paint bases and water-based paint bases can be developed into new paint formulas based on the research scheme of the present application.

[0051] Further, when the metal effect paint is prepared by using the oil-based paint base, the following steps are included:

[0052] The inorganic flaky material, aluminum pigment and solvent are added into a mixing tank and stirred at a low speed until they are mixed uniformly, and then added into the oil-based paint base to obtain the metal effect paint with improved brightness;

[0053] When the metal effect paint is prepared by using the water-based paint base, the following steps are included:

[0054] The inorganic flaky material, aluminum pigment and part of the water-based paint base are added into a mixing tank and stirred at a low speed until they are mixed uniformly, and then added into the water-based paint base to obtain the metal effect paint with improved brightness.

[0055] Further, the solvent is selected from one or more of ester solvents, ketone solvents, aromatic hydrocarbon solvents or alcohol solvents, and is preferably one or more of ethyl acetate, butyl acetate, propylene glycol methyl ether acetate, butanone, cyclohexanone, dimethylbenzene, propanol or butanol.

[0056] Further, the stirring speed at the low speed is 100-300 rpm, and the stirring speed after the oil-based paint base or the water-based paint base is added is 300-500 rpm.

[0057] The second aspect of the present application provides a metal effect paint obtained based on the method as described above.

[0058] The third aspect of the present application provides the use of the metal effect paint as described above in preparing a low-car automobile radar shielding coating and the use of the metal effect paint in forming a radar wave transparent coating on a plastic substrate. The application provided by the present application takes into account the high requirement for automobile radar wave transmittance in some specific use scenarios (e.g. automobile bumpers), which leads to the problem of limited use of aluminum pigment and low brightness of the paint film. The metal effect paint provided by the present application can be directly used to form a radar wave transparent coating on a plastic substrate, or can be used to form a radar wave transparent coating on a plastic substrate after adding some conventional color pigments to the base.

[0059] Further, the dry film thickness of the transparent coating is 10-18 μm, and in order to ensure the transmittance of automobile radar waves, it is appropriate to control it within 12-15 μm.

[0060] Further, the conventional color pigments can use inorganic pigments, organic pigments or mixtures thereof, which are referred to as pigments whose optical properties are not angle-dependent (angle of incidence or angle of observation), which is in sharp contrast to the metallic effect pigments. If desired, these conventional pigments are used to impart color to the coating film. In the metallic effect paint system of the present application, suitable organic colored absorbing pigments include, but are not limited to, monoazo pigments (e.g., C.I. Pigment Yellow 1, 3; C.I. Pigment Orange 5, 38; C.I. Pigment Red 1, 2, etc.), disazo pigments (e.g., C.I. Pigment Yellow 12, 13; C.I. Pigment Orange 16, 34, etc.), disazo condensation pigments (e.g., C.I. Pigment Yellow 93, 95; C.I. Pigment Red 144, 166, etc.), anthanthrone pigments (e.g., C.I. Pigment Red 168, etc.), anthraquinone pigments (e.g., C.I. Pigment Yellow 147; C.I. Pigment Red 177, etc.), anthrapyrimidine pigments (e.g., C.I. Pigment Yellow 108, etc.), benzimidazolone pigments (e.g., C.I. Pigment Yellow 120, 151; C.I. Pigment Orange 36; C.I. Pigment Red 175, etc.), quinacridone pigments (e.g., C.I. Pigment Orange 48; C.I. Pigment Red 122, etc.), quinophthalone pigments (e.g., C.I. Pigment Yellow 138, etc.), diketopyrrolopyrrole pigments (e.g., C.I. Pigment Orange 71, etc.), dioxazine pigments (e.g., C.I. Pigment Violet 23, etc.), flavanthrone pigments (e.g., C.I. Pigment Yellow 24, etc.), isoindoline pigments (e.g., C.I. Pigment Yellow 139, etc.), isoindolinone pigments (e.g., C.I. Pigment Yellow 109, etc.), isoindigo violet pigments (e.g., C.I. Pigment Violet 31, etc.), metal complex pigments (e.g., C.I. Pigment Red 257, etc.), perinone pigments (e.g., C.I. Pigment Orange 43, etc.), perylene pigments (e.g., C.I. Pigment Red 123, etc.), pyranthrone pigments (e.g., C.I. Pigment Orange 51, etc.), pyrazoloquinazolone pigments (e.g., C.I. Pigment Orange 67, etc.), indigo pigments (e.g., C.I. Pigment Red 282, etc.), thioindigo pigments (e.g., C.I. Pigment Red 88, etc.), triarylcarbonium pigments (e.g., C.I. Pigment Red 81, etc.), or mixtures thereof (including their solid solutions or mixed crystals), and color pigments can be used as long as they do not contain pearlescent components, with the aim of meeting customer needs.

[0061] Further, the plastic substrate can be an automobile bumper, radiator grille, automobile back plate, door trim, rearview mirror housing, etc.

[0062] The technical solutions of the present application will be further illustrated below through specific examples.

[0063] Oily systems

[0064] Some metal effect color paint formulations prepared during the study are provided in Table 1, wherein Scheme 1 is used as a control group for comparison with Schemes 2 to 12, the way to improve the brightness of the paint film in Scheme 2 is to additionally add aluminum pigment, Schemes 3 to 5 are specific schemes developed based on the design idea of the prior art, that is, the way to improve the brightness of the paint film is to additionally add pearl pigment, and Schemes 6 to 12 are specific schemes developed based on the design idea of the present application, that is, the way to improve the brightness of the paint film is to additionally add inorganic flaky material.

[0065] Table 1 metal effect color paint formulations

[0066] During the test, the selected pearl pigments are iriodin series 9602 and 9121 of Merck and OEM FINE SILVER product of OEM series of Aika Company, wherein 9602 of Merck is a silver pearl product, and other models are white pearl products with different degrees of sparkle. These pearl pigments mostly have a D50 size of 5-40 μm. Of course, the selected pearl pigments are not limited to the above suppliers.

[0067] The metal effect color paint is prepared according to the formulations in Table 1, and the specific process is as follows:

[0068] Schemes 1 and 2: aluminum pigment 4660NS and butyl acetate are added to the kettle, stirred at 100-300 rpm until mixed uniformly, then added to Pin 600 thick color base and Pin 600 light color base, stirred at 300-500 rpm to obtain metal effect color paint;

[0069] Schemes 3 to 5: aluminum pigment 4660NS, pearl powder and butyl acetate are added to the kettle, stirred at 100-300 rpm until mixed uniformly, then added to Pin 600 thick color base and Pin 600 light color base, stirred at 300-500 rpm to obtain metal effect color paint;

[0070] Schemes 6 to 12: aluminum pigment 4660NS, inorganic flaky material and butyl acetate are added to the kettle, stirred at 100-300 rpm until mixed uniformly, then added to Pin 600 thick color base and Pin 600 light color base, stirred at 300-500 rpm to obtain metal effect color paint.

[0071] Performance Test 1

[0072] A PP plate with a thickness of 3 mm (size: 150*200 mm) was sequentially sprayed (sprayed by an ecogun machine) with a primer, a color paint and a topcoat, and the models and thicknesses of the primer, the color paint and the topcoat were shown in the following table. After spraying, the plate was baked in an oven at 80°C for 30 min to obtain a paint film.

[0073] Table 2 Information of each coating in an oily system

[0074] The optical indexes of the paint film were tested by using a BYK-MAC tester, and the results were shown in Table 3.

[0075] Table 3 Summary of the optical indexes of the paint film Note: FI is the index of the color flop, and G is the degree of sparkle.

[0076] The results show that:

[0077] 1) As can be seen from Scheme 1 to Scheme 2, compared with Scheme 1, the additional addition of aluminum pigment has a significant effect on the brightness of the paint film, and the brightness of L25° and L45° is obviously improved, while the brightness of L15° is slightly decreased.

[0078] 2) As can be seen from Scheme 1, Scheme 3 to Scheme 5, compared with Scheme 1, the pearl powder has a significant effect on the brightness of the paint film. After the additional addition of the pearl powder, the brightness of L45° is obviously improved in Scheme 3 to Scheme 5, the brightness of L25° is limitedly improved, and the brightness of L15° is obviously decreased. This may be because the multi-layer refraction structure of the pearl powder affects the mirror reflection characteristics of the aluminum sheet, and affects the FI value. At the same time, the pearl powder can cause the b value to be obviously deviated, causing the color to deviate, especially the b110° is most sensitive, which may be because the interference color of the pearl affects.

[0079] 3) As can be seen from Scheme 1, Scheme 6 to Scheme 12, compared with Scheme 1, the inorganic flaky material can improve the brightness of the paint film in general. Among them, Scheme 6 to Scheme 12 can obviously improve the brightness of L45°, Scheme 6 to Scheme 10 can improve the brightness of L25°, Scheme 6, Scheme 8, Scheme 9 and Scheme 11 can slightly decrease the brightness of L15°, and the difference is not large, but Scheme 7, Scheme 10 and Scheme 12 can obviously decrease the brightness of L15°. At the same time, for this transparent inorganic flaky material without a wrapping layer, there is no obvious color deviation, and the b value deviation is very low, which is equivalent to the result of Scheme 1. It is found by comparing Scheme 6 to Scheme 12 that when the ratio of the amount of the flaky material to the amount of the aluminum pigment is 0.5 (Scheme 9 or Scheme 11), the brightness of L15° is higher than that of Scheme 6 or Scheme 7, and the brightness of L45° is relatively low. When the amount of the flaky material to the amount of the aluminum pigment is 1.4 (Scheme 10 or Scheme 12), the brightness of L15° is obviously decreased, and the brightness of L45° is obviously increased. This is because the flaky material is excessively stacked, which greatly affects the reflection characteristics of the aluminum pigment.

[0080] 4) From Scheme 2, Scheme 6 to Scheme 12, compared with Scheme 2, Scheme 6, Scheme 8, Scheme 10 and Scheme 12 have obvious improvement in L45°, and Scheme 6, Scheme 8, Scheme 9 and Scheme 11 have obvious improvement in L15°, which shows that the inorganic sheet material has reached the effect of improving the brightness of the paint film to a certain extent, and even better than the improvement effect of the aluminum pigment.

[0081] 5) From Scheme 1 to Scheme 12, the pearl powder and the inorganic sheet material have little effect on the G value, which shows that the inorganic sheet structure will not affect the sparkling of the silver powder in the oil-based system.

[0082] Water-based system

[0083] Some metal effect color paint formulations prepared during the study are provided in Table 4, wherein Scheme 13 is used as a control group for effect comparison with Scheme 14 to Scheme 20, the way to improve the brightness of the paint film in Scheme 14 is to add aluminum pigment, Scheme 15 to Scheme 17 are specific schemes developed based on the design idea of the prior art, that is, the way to improve the brightness of the paint film is to add pearl pigment, and Scheme 18 to Scheme 20 are specific schemes developed based on the design idea of the present application, that is, the way to improve the brightness of the paint film is to add inorganic sheet material.

[0084] Table 4 Metal effect color paint formulations

[0085] The metal effect color paint is prepared according to the formulations in Table 4, and the specific process is as follows:

[0086] Scheme 13, Scheme 14: Add aluminum pigment 4660NS and sunlight silver half product into the tank, stir at 100-300 rpm until mixed evenly, then add into the sunlight silver BASE, stir at 300-500 rpm to obtain the metal effect color paint;

[0087] Scheme 15 to Scheme 17: Add aluminum pigment 4660NS, pearl powder and sunlight silver half product into the tank, stir at 100-300 rpm until mixed evenly, then add into the sunlight silver BASE, stir at 300-500 rpm to obtain the metal effect color paint;

[0088] Scheme 18 to Scheme 20: Add aluminum pigment 4660NS, inorganic sheet material and sunlight silver half product into the tank, stir at 100-300 rpm until mixed evenly, then add into the sunlight silver BASE, stir at 300-500 rpm to obtain the metal effect color paint.

[0089] Performance test 2

[0090] A primer, a color paint and a topcoat were sprayed (ecogun machine spraying) on a 3mm-thick PP plate (size 150*200mm) in sequence, and the type and thickness of each layer of the primer, the color paint and the topcoat were shown in the following table. After spraying, the paint film was baked in an 80°C oven for 30min.

[0091] Table 5 Information of each coating in waterborne system

[0092] The optical indicators of the paint film were tested using a BYK-MAC tester, and the results were shown in Table 6.

[0093] Table 6 Summary of optical indicators of paint film Note: FI is the index of the color flop, and G is the degree of sparkle.

[0094] The results show that:

[0095] 1) As can be seen from Scheme 13 to Scheme 14, compared with Scheme 13, the additional addition of aluminum pigment has a significant effect on the brightness of the paint film, and the brightness of L15°, L25° and L45° is significantly improved.

[0096] 2) As can be seen from Scheme 13, Scheme 15 to Scheme 17, compared with Scheme 13, the pearl powder has a significant effect on the brightness of the paint film, and the brightness of L45° is significantly improved after the additional addition of pearl powder in Scheme 15 to Scheme 17, the brightness of L25° is not greatly affected, and the brightness of L15° is decreased, which may be because the multi-layer refraction structure of the pearl powder affects the mirror reflection characteristics of the aluminum sheet, and affects the FI value. At the same time, the pearl powder will cause a significant deviation of b value, causing color deviation, especially b110° is the most sensitive, which may be because of the influence of the interference color tone of the pearl.

[0097] 3) As can be seen from Scheme 13, Scheme 18 to Scheme 20, compared with Scheme 13, the inorganic flaky material can improve the brightness of the paint film in general, among which L45° is more obvious, and L15° and L25° are limitedly improved. At the same time, for this transparent inorganic flaky material without a wrapping layer, there is no obvious color deviation, and the b value deviation is very low, which is comparable to the result of Scheme 13.

[0098] 4) As can be seen from Scheme 14, Scheme 18 to Scheme 20, compared with Scheme 14, although the brightness improvement effect of Scheme 18 to Scheme 20 cannot reach that of Scheme 14, the difference in brightness results between Scheme 14 and Scheme 18 to Scheme 20 is not large.

[0099] 5) As can be seen from Scheme 13 to Scheme 20, the pearl powder and the inorganic flaky material have little effect on the FI and G values, which shows that the inorganic flaky structure will not affect the silver powder's color flop and sparkle characteristics in the oil-based system.

[0100] Performance test 3

[0101] Representative schemes 2, 6, 14 and 18 were selected for gloss and distinctness of image test, and the results are shown in Table 7. The results show that the addition of inorganic flaky material does not affect the gloss and distinctness of image of the paint layer. The gloss is tested by using a BYK gloss tester, and the distinctness of image is tested by using a BYK orange peel tester.

[0102] Table 7

[0103] Obviously, the above embodiments of the present application are only examples for clearly illustrating the present application, and are not intended to limit the embodiments of the present application. For those skilled in the art, other different forms of changes or variations can be made on the basis of the above description, and it is impossible to enumerate all the embodiments here. Any obvious changes or variations derived from the technical solutions of the present application are still within the protection scope of the present application.

Claims

1. A method of improving the brilliance of metallic effect paint, characterized in that, In the process of preparing the metallic effect color paint, inorganic flaky material is added to improve the brightness of the formed paint film. The inorganic flaky material is a flaky base material without a coating layer on the surface and without optical color, and accounts for 0.3-3wt% of the total mass of the metallic effect color paint.

2. The method of claim 1, wherein, The inorganic flaky material is selected from one or more of synthetic mica flake, natural mica flake, alumina flake, titanium dioxide flake, and glass flake treated with silane coupling agent. Preferably, the D50 of the inorganic flaky material ranges from 5 to 50μm, the average thickness is 100-1000nm, and the transparency is >80%. Preferably, the inorganic flaky material is selected from the synthetic mica flake SM series of Kuncaitech and / or the nanoglass flake nanoflake series of Glass Flake Company.

3. The method of claim 1, wherein, The raw materials of the metallic effect color paint further include at least the following two raw material components: an oil-based color paint base or a water-based color paint base; and aluminum pigment; The aluminum pigment accounts for 1-5wt% of the total mass of the metallic effect color paint.

4. The method of claim 3, wherein, The mass ratio of the inorganic flaky material to the aluminum pigment is 0.3-1.

0.

5. The method of claim 3, wherein, The D50 of the aluminum pigment ranges from 5 to 30μm, and the solid content is 65-75%. Preferably, the aluminum pigment is selected from 4660NS of Toyo Aluminum.

6. The method of claim 3, wherein, The oil-based color paint base is selected from the pin600 series of Riwba Company. The water-based color paint base is selected from the sunlight silver BASE and the sunlight silver half product of Riwba Company.

7. The method of claim 3, wherein, When the oil-based color paint base is used to prepare the metallic effect color paint, the method is specifically as follows: The inorganic flaky material, aluminum pigment, and solvent are added to a mixing tank, stirred at low speed until mixed uniformly, and then added to the oil-based color paint base, and the process is completed. When the water-based color paint base is used to prepare the metallic effect color paint, the method is specifically as follows: The inorganic flaky material, aluminum pigment, and part of the water-based color paint base are added to a mixing tank, stirred at low speed until mixed uniformly, and then added to the water-based color paint base, and the process is completed.

8. Metallic effect color paint, characterized in that The method is prepared by using the method of any one of claims 1-7.

9. Use of the metallic effect color paint of claim 8 in the preparation of low-car automobile radar shielding paint.

10. Use of the metallic effect color paint of claim 8 for forming a radar wave transparent coating on a plastic substrate.

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