Solvent

A solvent is a substance that dilutes and dissolves solid, liquid or gaseous substances without changing them or itself chemically. There are lots of solvents as e.g. water (for varnishes, paints), alcohols (for resins, paints), and hydrocarbons (for resins, synthetic resins/reaction resins). Solvents are used to reduce the viscosity of a substance. Example coating material based on reaction resins: Here, highly volatile liquids are admixed so that the material can be applied easily (paint roller, spraying device). In air the solvent volatilises and the viscosity increases. If the solvent cannot volatilise (coating too thick), bubbles may form and deteriorate the quality of the coating. In order to avoid unwanted sedimentation as well as an increased impairment of the chemical stability, the viscosity may not be reduced too much by the addition of solvents.