Why mineral oil defoamer is used in coatings.
      The evaluation of coating defoamer can be carried out from the following aspects: defoamer performance, brushing test and the stability of the defoamer itself. Adding a defoamer usually involves two steps:
      The pigment is first added when it is dispersed at high speed, mainly to make the surface of the filled fine particles sufficiently wet.
      Secondly, mixed paste is added in the coating process to further eliminate the generation of bubbles in the coating process.
Two steps add defoamer depending on the actual situation, usually the first step add 1/2, the second step add 1/2. The coating test is very important, mainly used to evaluate the shrinkage hole, shrinkage hole, shrinkage hole, fisheye and so on. Investigations into such phenomena are at least 24 hours away.
      Mineral oil defoamer is generally composed of carrier, activator, development agent, etc. Substances that reduce surface tension are load-bearing and dilutive. The common carriers are water, hydrocarbon, lipid alcohol and so on. The function of the activator is to resist and remove foam. The choice of activator depends on the characteristics of the medium.
      Common wax, silicone oil, fat amide, polymerized polyethylene glycol, fatty acid ester, hydrophobic white carbon black, etc.