Aluminum paste is a kind of slurry metal pigment which is made of ultra-fine snow flakes or silver circular aluminum flakes by special process. Although aluminum paste is safer and less prone to fire or explosion than aluminum powder, it contains aluminum particles, so special attention should be paid to handling and use.
The optical effect of aluminum paste varies greatly depending on the size of aluminum particles, the size distribution of aluminum particles and the surface treatment method of the particles. Due to the difference in its cutting-edge materials and processing technology, aluminum silver paste is also very different in terms of whiteness, brightness, triggering properties, metal properties, smoothness and other properties, so there are many kinds of products. Other performance variations are often required to meet more complex requirements. The application of advanced particle surface treatment processes offers a variety of products with special performance grades to meet these requirements.
Safe Storage Instructions
※ Store indoors in a sealed tank at a temperature of 15 ~ 40℃. Avoid direct exposure to sunlight, rain, or excessive temperatures.
※ Ensure that the storage temperature is not lower than 15 ° C (special attention should be paid in winter or when the surrounding temperature is equal to or below 10 ° C).
※ Excessive turbulence during transportation and storage under certain conditions may lead to partial separation of aluminum and solvent components. Therefore, high-speed stirring should be avoided during use to avoid damaging the shape of the silver sheet.
Use skills
As a kind of metal pigment, aluminum silver paste can make the coating produce special effects different from other ordinary pigments, and some skills in the use process are briefly described.
1, in order to achieve satisfactory special results, aluminum silver paste must be completely dispersed in the coating system, the coating should be uniform, no fine particles. Aluminum flake is easy to bend and break, in the paint production process if through high-speed stirring or other continuous intense processing, its geometric structure is easy to be destroyed, resulting in coarse grain, dark color, reduced covering force, and metal movement and other adverse phenomena. Therefore, dispersion means with high shear force should not be used.
Recommendation: Use the pre-dispersion method: first choose the appropriate solvent or a mixture of several solvents, with the ratio of aluminum silver paste and solvent 1:1 or 1:2 ratio, add the solvent to the aluminum silver paste, slowly stir until uniform (about 10-20 minutes). Add the base material to the system. In general production, the aluminum silver paste is soaked in solvent for 30 minutes in advance and then slowly stirred.
2. The dilution choice of aluminum silver paste is mainly determined by the paint material determined by the formula. Non-floating aluminum silver pulp can be widely used in polar and non-polar solvents, such as aliphatic or aromatic hydrocarbons, lipids (such as butyl acetate), ketones (such as methyl ethyl ketone, methyl isobutyl ketone), alcohols (such as ethanol).
3, chlorine-containing solvents (halogenated...) Not suitable for any aluminum silver paste pigments. Chlorinated solvents release HCL, which reacts with the fine aluminum pigments.
4, many commonly used paint base materials such as oil varnish base, acrylic acid, alkyd, ring itching ester and water-based base material, can be applied in non-floating aluminum silver paste pigment. In general, any coating base or solvent is suitable as long as it is compatible with the solvent carrier of the aluminum silver paste and does not cause chemical damage to the aluminum silver paste.
Special attention: aluminum is a kind of active metal, paint acid value should be controlled below 7.
5, when a coating system containing aluminum silver paste needs to add metal drier, for non-floating aluminum silver paste, only the drier that will not react with the fatty acid on the surface of the aluminum scale can be used, it is recommended to use drill, zirconium, manganese drier.
6. Add ratio:
The proportion of aluminum silver paste added to colored primer is 1%-4%
The proportion of aluminum silver paste added to the solid silver primer is 4%-10%
Single-layer metal flash paint aluminum silver paste added ratio of 5%-13%
The addition ratio of aluminum silver paste for anti-corrosion paint, canning, and coil coating is 10%-13%
7, the film surface is parallel orientation, to achieve the best effect. Poor parallel orientation can result in turbidity or diffuse reflection. The orientation of flake pigment is related to the formulation and construction conditions. The evaporation of the solvent causes the wet coating film to shrink, and finally presses the aluminum pigment into a horizontal orientation position. The higher the solvent content in the paint, the stronger this effect. This explains the orientation of the flaky pigment. Therefore, the optical properties of low-solid coatings are better than those of high-solid coatings.
The volatilization of the solvent will cause a strong eddy inside the wet film, but if the solvent volatilization is too slow, it will form the so-called Nald vortex, which will hinder the parallel orientation of the aluminum pigment (resulting in turbidity).
Resins can be used to promote solvent volatilization (such as butyl cellulose CAB), and some auxiliaries are also used. They hold the flaky pigment in place. It has been reported in the literature that wax dispersion has "; Interval action" Surfactants have a similar function. However, it should be tested before use.
Note: The optical properties of relatively low solids coatings are better than those of relatively high solids coatings within a certain range.
