How To Choose Pigment For Water-based Color Paste
Pigment red 168 manufacturer said that water-based color paste is a semi-finished product formed by pigments and other fillers, dispersed in the paint, which is used to realize the coloring function of water-based color paste by using all kinds of pigments, including organic pigments and inorganic pigments. Therefore, the quality of pigment directly affects the quality of waterborne color paste, so when choosing pigment for waterborne color paste, we must pay attention to the following matters:
Prefer pigments with bright color and stable performance
When designing the color mixing formula, we should try to choose the color paste with good weather resistance and light resistance. The color paste of inorganic pigment, although good light resistance, cheap, but the vividness is not high, can not modulate the color of high saturation. Organic pigment color paste, bright color, high coloring power, whether in the modulation of dark or light colors, have a high degree of saturation, but light resistance, weather resistance is a little worse. If the two can be used in combination, both to meet the hue and saturation, but also to ensure that the color of light and weather resistance, and affordable.
Testing the coloring strength of pigment in water-based system
You can do a simple water-based color paste formula test in the laboratory of pigment factory, use the method of high-speed stirring and dispersion, under the high-speed rotation speed, dispersion for 180-300 minutes, take out the color paste, add 2% of the water-based binder, it can reflect the coloring strength in the water-based system.
Testing the stability of pigment in water-based color paste
The range of pigment addition in water-based color paste is very wide, the water-based ink containing resin is generally 5~10%, resin-free organic pigment-based water-based color paste is generally 20~50%, resin-free inorganic pigment-based water-based color paste is generally 40~80%. The adding amount of pigment is designed according to the application performance of the product, the state of pigment particles and the equipment for dispersing the water-based color paste, but it is not recommended to add too much or it may lead to the unstable reaction of viscosity change such as thickening of the water-based color paste.
Chemical properties of water-based color paste
Water-based color paste selection of pigments should also pay attention to its chemical properties, such as acid and alkali resistance. Before painting color latex paint should pay special attention to the construction of the painted wall alkaline strength, alkaline is too strong, the color is easy to fade, the more obvious phenomenon is the wall alkali, bite color, white.
Keep water-based color paste stable ideal PH value between 6.5 ~ 10. When there are conditions, the wall to be painted should be tested for alkaline strength, such as alkaline is too strong, the wall should be treated first, so that the construction of the wall PH <10, the treatment method is to use 5-10% of oxalic acid solution to clean.
Waterborne color paste pigment stability
The batch of water-based color paste pigment should also be kept stable, once the standard is determined, the pigment synthesis process should strictly control the conditions when the reaction occurs, in order to ensure the stability of the color of water-based color paste in various weather conditions. Construction wall must be kept clean and dry, no oil, no shelling, peeling phenomenon, water content should be less than 10%, the construction site ambient temperature should be kept above 8 ° C, the relative temperature is lower than 85% or so, to ensure that the color paste formulations of the color preservation of the exterior wall will not appear fade problems.
Safety index of water-based color paste pigment
Pigment manufacturers not only need to pay attention to the surface of the pigment, but also to choose the safety of raw materials, in the process of pigment synthesis, should confirm whether the reaction occurs sufficiently, whether there is the residue of raw materials, in the selection of equipment, pay attention to the use of safe equipment and pipeline, in order to avoid some trace unsafe ingredients into the pigment, but also to pay attention to the pigment packaging bag plasticizer and other material residues and other issues.