Water-based coatings use water as solvent, which has good energy saving and reduces fire hazards and air pollution during construction. Water-based paint has low requirements on the dryness of the material surface and strong coating adhesion, and can be directly applied even on wet surfaces and wet environments. In addition, the coating tool can be washed with water, which can reduce the consumption of cleaning solvent.
However, the dispersion stability of waterborne coatings to strong mechanical force is relatively poor. When the flow velocity in the pipeline changes sharply, the dispersed particles are compressed into solid particles, which is easy to cause pitting on the coating. Waterborne paint is corrosive to painting equipment, so it is necessary to use anti-corrosion lining or stainless steel material in construction, but the cost of these equipment is relatively high. In addition, baking water-based paint has strict requirements on the construction environment, which increases the investment and energy consumption of temperature and humidity control equipment.
Classification of water-borne paints
1, water-soluble type
Water-soluble resin is a film-forming substance, represented by polyvinyl alcohol and its various modifications, in addition to water-soluble alkyd resin, water-soluble epoxy resin and inorganic polymer water-based resin.
2, water dispersion type
Water-dispersible coatings mainly refer to coatings prepared with synthetic resin emulsion as film-forming substance. Emulsion refers to the dispersed emulsion composed of small particles dispersed in water, which is polymerized by unsaturated vinyl monomer in the presence of emulsifier at a certain temperature during mechanical stirring. A coating prepared by adding a little emulsion to a water-soluble resin cannot be called latex paint. Strictly speaking, water-diluted paint can't be called latex paint, but it is also customarily classified as latex paint.