Features of Evonik Coating Wetting Agent

1, Wetting of pigments and substrates
2, Excellent foam control
3, Reduced water sensitivity

The amount of drier and the factors affecting the drier performance

The drier is used in the air-drying and drying-type coatings that are oxidized to form a film. It not only modified wax value accelerates the drying, but also significantly affects the properties of the coating film, such as hardness, adhesion, flexibility, water resistance, and yellowing Performance and durability. Therefore, the amount and ratio of the drier should be fully considered based on the degree of unsaturation of the binder and the use requirements of the coating. For individual evaluation of the characteristics of the drier, it can be used as a guide for selection, but the appropriate composition of the drier must be determined. Therefore, careful and comprehensive tests must be carried out according to the principles of coating formulations.

1. The amount of drier
The amount of oil-based paint and drier is expressed in terms of the metal content of the solid content of the binder. It is now determined that the amount of cobalt drier in alkyd varnish is 0.033%, and the amount of manganese drier is 0.05%. The concentration of drill and manganese driers used is 2%, and the dosage of drier can be calculated as follows:
The dosage of the drier-the non-volatile content of the connecting material×
The metal demand of the drier (%)/the metal concentration of the drier (%)
The amount of linoleic alkyd resin used in alkyd varnish is 96kg, and the non-volatile content is 50%. Then the dosage of 2% cobalt drier and 2% manganese drier is:
2% cobalt drier-96kg×50%×0.033%/2%=0.8(kg)
2% manganese drier-96kgX 50%X 0.05%/2%=1.2(kg)

The amount of drier should be such that the dryness of the paint film meets the construction requirements. The drying rate of the paint film is not directly proportional to the amount of drier. For example, alkyd paint with 0.05% cobalt can reach finger dryness within 4 hours. When the cobalt content increases to 0.1%, it can only be shortened to 3 hours. When the dry time to touch is shortened to 2h, it will increase to 0.5%. In fact, the content of various driers is limited by various factors. For example, excessive amount of driers will cause the paint film to crust, wrinkle, and hair. Disadvantages such as fog and frost. Therefore, to greatly speed up the drying rate, the only way to change the type of paint used is to increase the drier.