1: Determine the grinding resin system
Based on many years of experience in the chemical industry, long oil alkyd resin, amino resin, polyamide resin, aldehyde and ketone resin, low molecular weight Resins such as hydroxypropylene and other resins have good wettability to pigments, while high molecular weight saturated polyester resins, low hydroxyl value hydroxypropylene, thermoplastic acrylic resins, etc. have poor wettability to pigments. The same pigment can be used under different conditions. The resin system will show different hues, especially organic pigments, carbon black and transparent iron oxide. The hues of different resins will be different, especially the diffuse hue. Therefore, when choosing a dispersant, in order to achieve accurate color mixing, it is necessary to According to the resin system, the compatibility of the dispersant and the resin, the viscosity reducing effect of the dispersant in the system, the color development and storage stability of the dispersant in the system are tested.
2: Choose based on pigments and fillers
Pigments are divided into several categories categories, namely organic pigments, inorganic pigments and carbon black
If the same resin and a dispersant can disperse carbon black and phthalocyanine pigments well at the same time , then it will largely show weak dispersing ability in DPP red organic pigments. Conversely, if a dispersant shows good dispersing ability in DPP red and other organic pigments, then use it to disperse carbon black or Phthalocyanine blue will have color difference or poor viscosity reduction.
This is most likely due to the strength of the hydrogen bond of the pigment itself, so it is best to use a single-structure dispersion It is difficult for dispersants to achieve good results in two different types of pigments. When actually choosing a dispersant, we must comprehensively consider it based on the parameters given by the pigment manufacturer. The most direct way is to apply it, but as we continue to summarize our experience in application experiments , in the end, many detours will be avoided, and exchanges with peers and friends are welcome.
