Similar to true solvents and co-solvents in solvent-based paints, film formation in water-based systems Auxiliaries play a similar role and can also be classified accordingly. Regarding the drying of water-based paints, there is a classic evaluation: the drying of solvent-based paints is dominated by temperature and interfered by humidity; the drying of water-based paints is dominated by humidity and interfered by temperature. The selection and matching of film-forming additives are crucial to the performance of the coating Importantly, if a formula performs well, it is because of the film-forming additive; vice versa. However, the process of volatilization of film-forming additives from the system is extremely complicated, especially for mixed solvents, and an accurate description cannot be given so far.
Some data on film-forming additives (for reference)
Film-forming additives | Boiling point/℃ | Surface tension (25℃)/(mN/m) | Evaporation (BuAC=100) | 90% evaporation time/s | Water solubility/% | 水在 Among them, solubility/% | ||
Ethylene glycol monobutyl ether | 170.2 | 27.4 | 7.9 | 7000 | ∞ | ∞ | ||
2 Ethylene glycol monomethyl ether | 194.1 | 24.6 | 1.9 | 29400 | ∞ | ∞ | ||
Diethylene glycol monoethyl ether | 201 | 31.7 | 1 | ∞ | ∞ | |||
Diethylene glycol monobutyl ether | 230.4 | 30 | 0.4 | 190000 | ∞ | ∞ | ||
Propylene glycol monomethyl ether | 120 | 27.7 | 62 | ∞ | ∞ | |||
Propylene glycol monopropyl ether | 149 | Propylene glycol methyl ether acetate | 146 | 26.9 | 33 | 16 | 3 | |
Dipropylene glycol methyl ether acetate | 209 | 27.3 | 1.5 | 16 | 3.5 |
Good film-forming aids: can reduce the usage of film-forming aids and make the formula more flexible;
Quick drying: This is self-evident for the importance of filler orientation and early performance;
Appropriate volatilization gradient: Appropriate amount of slow evaporation film-forming additives can improve film density and prevent edge shrinkage. Very helpful;
Currently mainstream Film-forming additives include propylene glycol methyl ether (PM), ethylene glycol butyl ether (BCS), diethylene glycol ethyl ether (DEE) and diethylene glycol butyl ether (DEB).
Quick drying: This is self-evident in the importance of filler orientation and early performance;
Appropriate volatilization gradient: An appropriate amount of slow evaporation film-forming additives is of great help to the density of the film and the prevention of edge shrinkage;
The current mainstream choices of film-forming aids include Propylene glycol methyl ether (PM), ethylene glycol butyl ether (BCS), diethylene glycol ethyl ether (DEE) and diethylene glycol butyl ether (DEB).