A large-diameter round cake-shaped thick silver flash and its preparation method

Abstract

The present invention belongs to the technical field of fine powder materials, and specifically relates to a large-particle-size round cake-shaped thick silver flash and a preparation method thereof. The method comprises the following steps: (1) according to the mass fraction, 40-60 parts of aluminum powder, 2-5 parts of ball milling aid, 0.1-1.0 parts of additive, 0.2-0.4 parts of dispersant, and 200-300 parts of solvent oil are added to a ball mill, and a stainless steel ball with a diameter of 3.00-8.00 mm is used as a ball milling medium, and the first stage of ball milling and the second stage of ball milling are performed in sequence; (2) the material after ball milling in step (1) is screened, graded, and filter-filtered into a filter cake in sequence, and the filter cake is kneaded to obtain. The particle size of the product of the present invention is more than 80 microns, and the thickness of the aluminum sheet is more than 2 microns. The product is shaped like a round cake, with a smooth and flat surface, good shear resistance, not easy to break or fracture, strong flashing, no obvious angular color change, and good product whiteness.

Description

Technical Field

[0001] The invention belongs to the technical field of fine powder materials, and in particular relates to a large-diameter round cake-shaped thick silver flash and a preparation method thereof. Background Art

[0002] As an important functional material, aluminum paste has been widely used in many industries such as automotive coating, ink printing, and plastic processing due to its unique metallic luster and angular color effect. In particular, aluminum paste produced by wet ball milling has become the mainstream product in the market due to its advantages such as controllable particle size, uniform dispersion, and rich colors. Flash silver is the type of aluminum paste with the largest average particle diameter. Due to its large particles, the reflection and scattering of light on the surface of the particles is stronger, so the scintillation is high and the brightness is strong. Flash silver visually presents a strong and dazzling metallic luster, and is mostly used in coating and printing occasions that require high brightness and high reflectivity. The particle shape and size of flash silver have an important influence on the product's scintillation effect, angular color effect, and overall aesthetics.

[0003] Although current technology can produce aluminum-silver paste with a particle size of about 80 microns, it is still difficult to meet the larger particle size requirements of high-end fields such as high-end automotive coatings and luxury decorative materials to achieve a rougher and more three-dimensional metal texture. The increase in particle size leads to irregular shapes and decreased stability of aluminum flakes, which becomes a technical bottleneck for the production of large-particle aluminum-silver paste. The existing wet ball-milled aluminum flakes are irregular in shape and often have jagged cracks, which affect the appearance and physical properties; and the aluminum flakes are generally thin, and are very easy to break or shatter when subjected to external mechanical forces, which reduces product stability and service life, and may also weaken the metal texture of the coating. In addition, the flashing effect of these products is not strong enough due to the irregular shape and fragility of the aluminum flakes, and it is difficult to meet the market's expectations for high-sparkling products.

[0004] In order to overcome the above problems, it is urgent to solve the problems of irregular particle shape, small particle size and thin thickness of the existing silver flash products produced by wet ball milling. Summary of the invention

[0005] One of the purposes of the present invention is to provide a method for preparing large-particle-size round-cake-shaped thick silver flash. The method successfully prepares a round-cake-shaped aluminum silver paste product with a particle size of 80 microns or more and an aluminum sheet thickness of more than 2 microns by optimizing the ball milling process and the additive formula.

[0006] To achieve the above object, the present invention adopts the following technical solutions:

[0007] A method for preparing large-diameter round cake-shaped thick silver flash comprises the following steps:

[0008] (1) According to the weight percentage, 40-60 parts of aluminum powder, 2-5 parts of ball milling aid, 0.1-1.0 parts of additive, 0.2-0.4 parts of dispersant, and 200-300 parts of solvent oil are added into a ball mill, and stainless steel balls with a diameter of 3.00-8.00 mm are used as ball milling media, and the first stage ball milling and the second stage ball milling are carried out in sequence;

[0009] The average particle size of the aluminum powder is 30-50µm; the speed of the first stage of ball milling is 8r / min, and the ball milling time is 15-18h; the speed of the second stage of ball milling is 5r / min, and the ball milling time is 12-15h; the additive is erucic acid; the solvent oil is naphthalene-free heavy aromatics; the auxiliary agent is oleic acid; the dispersant is 201P dispersant;

[0010] (2) The material after ball milling in step (1) is screened, graded, and filtered to form a filter cake, and the filter cake is kneaded to obtain;

[0011] The mesh sizes of the sieving are 80 mesh and 200 mesh.

[0012] The second object of the present invention is to provide a large-particle round cake-shaped thick silver flash. The product has a particle size of more than 80 microns, and the thickness of the aluminum sheet is more than 2 microns. The product is in the shape of a round cake, has a smooth surface, has good shear resistance, is not easy to break or fracture, has a strong sense of flash, has no obvious angle-dependent color change, and has good whiteness.

[0013] To achieve the above object, the present invention adopts the following technical solutions:

[0014] The above-mentioned large-particle-size round-cake-shaped thick silver flash is prepared by adopting any of the above-mentioned preparation methods.

[0015] Compared with the prior art, the present invention has the following beneficial effects:

[0016] 1. The present invention can not only obtain products with large particle sizes of more than 80 μm, but also obtain aluminum sheets with a thickness of more than 2 μm, and a smooth and flat surface.

[0017] 2. The product obtained by the present invention can present a brick-like glittering effect, has excellent shear resistance and good decorative effect, and can meet the current market demand.

[0018] 3. The present invention provides a method for preparing large-diameter round cake-shaped thick silver flash, which has a simple and efficient process and is conducive to realizing industrial production. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 This is a microscopic morphology of the product obtained in Example 1 of the present invention;

[0020] Figure 2This is a microscopic morphology of the product obtained in Example 2 of the present invention;

[0021] Figure 3 This is a microscopic morphology of the product obtained in Example 3 of the present invention;

[0022] Figure 4 This is a microscopic morphology of the product obtained in Comparative Example 1 of the present invention;

[0023] Figure 5 This is a microscopic morphology of the product obtained in Comparative Example 2 of the present invention;

[0024] Figure 6 This is a microscopic morphology of the product obtained in Comparative Example 3 of the present invention;

[0025] Figure 7 This is a macroscopic morphology of the product obtained in Example 1 of the present invention;

[0026] Figure 8 This is a particle size distribution diagram of the product obtained in Example 1 of the present invention. DETAILED DESCRIPTION

[0027] The technical solution of the present invention is further explained below in conjunction with specific embodiments, comparative examples and test examples.

[0028] In the following examples, comparative examples and test examples, the raw materials and preparation methods used are conventional materials and techniques in the art unless otherwise specified.

[0029] The dispersant in the present invention is a high molecular polymer type dispersant, and its model is 201P; the naphthalene-free heavy aromatic solvent H-100 is purchased from Yueyang Baling Petrochemical Co., Ltd.

[0030] Example 1

[0031] (1) 50 kg of aluminum powder with a particle size of 40 µm, 4 kg of oleic acid, 0.5 kg of erucic acid, 0.3 kg of 201P dispersant, and 250 kg of solvent oil (naphthalene-free heavy aromatic solvent H-100) were placed in a ball mill (ball mill drum 1.1 m × 1.2 m, motor 11 kW, reducer transmission ratio 90:1) to obtain a mixed material; stainless steel balls with a diameter of 6.0 mm were selected as ball milling media, and the filling amount of stainless steel balls was one-third of the volume of the ball mill cylinder. The mixed material was ball milled at 8 r / min for 16 h, and then at 5 r / min for 14 h, and then the material was discharged;

[0032] (2) The material after ball milling in step (1) is first sieved through an 80-mesh sieve and then sieved through a 200-mesh sieve, and the material obtained between the two (i.e., the particle size is between 80 mesh and 120 mesh) is filtered; the filter cake obtained after the filtration is kneaded to obtain.

[0033] Example 2

[0034] (1) 40 kg of aluminum powder with a particle size of 35 µm, 2 kg of oleic acid, 0.1 kg of erucic acid, 0.2 kg of 201P dispersant, and 200 kg of solvent oil (naphthalene-free heavy aromatic solvent H-100) are placed in a ball mill (ball mill drum 1.1 m × 1.2 m, motor 11 kW, reducer transmission ratio 80:1) to obtain a mixed material, and stainless steel balls with a diameter of 3.0 mm are selected as ball milling media, and the filling amount of stainless steel balls is one third of the ball mill volume; the mixed material is ball milled at 8 r / min for 15 h; and then ball milled at 5 r / min for 12 h; and the material is discharged;

[0035] (2) The material after ball milling in step (1) is first sieved through an 80-mesh sieve and then sieved through a 200-mesh sieve, and the material obtained between the two (i.e., the particle size is between 80 mesh and 120 mesh) is filtered; the filter cake obtained after the filtration is kneaded to obtain.

[0036] Example 3

[0037] (1) 60 kg of aluminum powder with a particle size of 50 µm, 5 kg of oleic acid, 1.0 kg of erucic acid, 0.4 kg of 201P dispersant, and 300 kg of solvent oil (naphthalene-free heavy aromatic solvent H-100) are placed in a ball mill (ball mill drum 1.1 m × 1.2 m, motor 11 kW, reducer transmission ratio 100:1) to obtain a mixed material, and stainless steel balls with a diameter of 8.0 mm are selected as ball milling media, and the filling amount of stainless steel balls is one third of the volume of the ball mill; the mixed sample is ball milled at 8 r / min for 18 h; and then ball milled at 5 r / min for 15 h; and the material is discharged;

[0038] (2) The material after ball milling in step (1) is first sieved through an 80-mesh sieve and then sieved through a 200-mesh sieve, and the material obtained between the two (i.e., the particle size is between 80 mesh and 120 mesh) is filtered; the filter cake obtained after the filtration is kneaded to obtain.

[0039] Comparative Example 1

[0040] This comparative example 1 is basically the same as Example 1, except that: this comparative example 1 omits the addition of erucic acid, and the rest is consistent with Example 1.

[0041] Comparative Example 2

[0042] Comparative Example 2 is substantially the same as Example 1, except that in step (1), the mixed material is ball-milled at 8 r / min for 30 h, and the rest is the same as Example 1.

[0043] Comparative Example 3

[0044] Comparative Example 3 is substantially the same as Example 1, except that in step (1), the mixed material is ball-milled at 12 r / min for 30 h, and the rest is the same as Example 1.

[0045] Test Example 1

[0046] (1) The surface morphology of the products obtained in Examples 1 to 3 and Comparative Examples 1 to 3 was observed under a microscope. The experimental results are as follows: Figures 1 to 6 shown.

[0047] (2) The particle sizes of the products obtained in Examples 1 to 3 of the present invention and Comparative Examples 1 to 3 were tested using a BT-9300S laser particle size distribution analyzer. The experimental results are shown in Table 1. The macroscopic morphology of Example 1 is shown in Figure 7 The particle size distribution diagram is shown in Figure 8 shown.

[0048] Table 1

[0049]

[0050] From Table 1, Figures 1 to 6 It can be seen that the products obtained in Examples 1 to 3 of the present invention have a larger particle size, uniform thickness, a smooth surface, a round cake shape, a concentrated particle size distribution, and a smaller particle size distribution span. By observing Comparative Example 1, it can be seen that the addition of the additive erucic acid can improve the surface smoothness of the product, make the product particles regular in shape, and have smooth edges. The addition of the dispersant can improve the product's antioxidant properties, extend the storage time, and maintain wettability. After changing the ball milling method and rate in Comparative Examples 2 and 3, the product is broken, the particle size distribution is wide, the metallic texture is significantly reduced, the product appearance changes greatly, and the product becomes irregular.

[0051] The above are only preferred embodiments of the present invention, and are not limited to the above examples. For those skilled in the art, various changes and variations are possible under the principle of the present invention. Any modifications and improvements made should be considered within the scope of protection of the present invention.

Claims

1. A method for preparing large-diameter round cake-shaped thick silver flash, characterized in that: The steps include: (1) According to the weight percentage, 40-60 parts of aluminum powder, 2-5 parts of ball milling aid, 0.1-1.0 parts of additive, 0.2-0.4 parts of dispersant, and 200-300 parts of solvent oil are added into a ball mill, and stainless steel balls with a diameter of 3.00-8.00 mm are used as ball milling media, and the first stage ball milling and the second stage ball milling are carried out in sequence; The average particle size of the aluminum powder is 30-50µm; the speed of the first stage of ball milling is 8r / min, and the ball milling time is 15-18h; the speed of the second stage of ball milling is 5r / min, and the ball milling time is 12-15h; the additive is erucic acid; the solvent oil is naphthalene-free heavy aromatics; the auxiliary agent is oleic acid; the dispersant is 201P dispersant; (2) The material after ball milling in step (1) is screened, graded, and filtered to form a filter cake, and the filter cake is kneaded to obtain; The mesh sizes of the sieving are 80 mesh and 200 mesh.

2. A large-diameter round cake-shaped thick silver flash, characterized in that: The preparation method according to claim 1 is used for preparation.

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